Google Git
Sign in
llvm / llvm-project / 3e17864e76f593b8558cbb37f96d883fd9d60fc7 / . / clang / lib / Sema / SemaDecl.cpp
blob: 12bedae05f6f34d24e1a9d43f5b01f28a7a6844a [file] [log] [blame]
//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements semantic analysis for declarations.
//
//===----------------------------------------------------------------------===//
#include "TypeLocBuilder.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTLambda.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/CharUnits.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/EvaluatedExprVisitor.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/MangleNumberingContext.h"
#include "clang/AST/NonTrivialTypeVisitor.h"
#include "clang/AST/Randstruct.h"
#include "clang/AST/StmtCXX.h"
#include "clang/AST/Type.h"
#include "clang/Basic/Builtins.h"
#include "clang/Basic/DiagnosticComment.h"
#include "clang/Basic/PartialDiagnostic.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Lex/HeaderSearch.h" // TODO: Sema shouldn't depend on Lex
#include "clang/Lex/Lexer.h" // TODO: Extract static functions to fix layering.
#include "clang/Lex/ModuleLoader.h" // TODO: Sema shouldn't depend on Lex
#include "clang/Lex/Preprocessor.h" // Included for isCodeCompletionEnabled()
#include "clang/Sema/CXXFieldCollector.h"
#include "clang/Sema/DeclSpec.h"
#include "clang/Sema/DelayedDiagnostic.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/ParsedTemplate.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/ScopeInfo.h"
#include "clang/Sema/SemaARM.h"
#include "clang/Sema/SemaCUDA.h"
#include "clang/Sema/SemaHLSL.h"
#include "clang/Sema/SemaInternal.h"
#include "clang/Sema/SemaObjC.h"
#include "clang/Sema/SemaOpenACC.h"
#include "clang/Sema/SemaOpenMP.h"
#include "clang/Sema/SemaPPC.h"
#include "clang/Sema/SemaRISCV.h"
#include "clang/Sema/SemaSYCL.h"
#include "clang/Sema/SemaSwift.h"
#include "clang/Sema/SemaWasm.h"
#include "clang/Sema/Template.h"
#include "llvm/ADT/STLForwardCompat.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/SaveAndRestore.h"
#include "llvm/TargetParser/Triple.h"
#include <algorithm>
#include <cstring>
#include <optional>
#include <unordered_map>
using namespace clang;
using namespace sema;
Sema::DeclGroupPtrTy Sema::ConvertDeclToDeclGroup(Decl *Ptr, Decl *OwnedType) {
if (OwnedType) {
Decl *Group[2] = { OwnedType, Ptr };
return DeclGroupPtrTy::make(DeclGroupRef::Create(Context, Group, 2));
}
return DeclGroupPtrTy::make(DeclGroupRef(Ptr));
}
namespace {
class TypeNameValidatorCCC final : public CorrectionCandidateCallback {
public:
TypeNameValidatorCCC(bool AllowInvalid, bool WantClass = false,
bool AllowTemplates = false,
bool AllowNonTemplates = true)
: AllowInvalidDecl(AllowInvalid), WantClassName(WantClass),
AllowTemplates(AllowTemplates), AllowNonTemplates(AllowNonTemplates) {
WantExpressionKeywords = false;
WantCXXNamedCasts = false;
WantRemainingKeywords = false;
}
bool ValidateCandidate(const TypoCorrection &candidate) override {
if (NamedDecl *ND = candidate.getCorrectionDecl()) {
if (!AllowInvalidDecl && ND->isInvalidDecl())
return false;
if (getAsTypeTemplateDecl(ND))
return AllowTemplates;
bool IsType = isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND);
if (!IsType)
return false;
if (AllowNonTemplates)
return true;
// An injected-class-name of a class template (specialization) is valid
// as a template or as a non-template.
if (AllowTemplates) {
auto *RD = dyn_cast<CXXRecordDecl>(ND);
if (!RD || !RD->isInjectedClassName())
return false;
RD = cast<CXXRecordDecl>(RD->getDeclContext());
return RD->getDescribedClassTemplate() ||
isa<ClassTemplateSpecializationDecl>(RD);
}
return false;
}
return !WantClassName && candidate.isKeyword();
}
std::unique_ptr<CorrectionCandidateCallback> clone() override {
return std::make_unique<TypeNameValidatorCCC>(*this);
}
private:
bool AllowInvalidDecl;
bool WantClassName;
bool AllowTemplates;
bool AllowNonTemplates;
};
} // end anonymous namespace
void Sema::checkTypeDeclType(DeclContext *LookupCtx, DiagCtorKind DCK,
TypeDecl *TD, SourceLocation NameLoc) {
auto *LookupRD = dyn_cast_or_null<CXXRecordDecl>(LookupCtx);
auto *FoundRD = dyn_cast<CXXRecordDecl>(TD);
if (DCK != DiagCtorKind::None && LookupRD && FoundRD &&
FoundRD->isInjectedClassName() &&
declaresSameEntity(LookupRD, cast<Decl>(FoundRD->getParent()))) {
Diag(NameLoc,
DCK == DiagCtorKind::Typename
? diag::ext_out_of_line_qualified_id_type_names_constructor
: diag::err_out_of_line_qualified_id_type_names_constructor)
<< TD->getIdentifier() << /*Type=*/1
<< 0 /*if any keyword was present, it was 'typename'*/;
}
DiagnoseUseOfDecl(TD, NameLoc);
MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false);
}
namespace {
enum class UnqualifiedTypeNameLookupResult {
NotFound,
FoundNonType,
FoundType
};
} // end anonymous namespace
/// Tries to perform unqualified lookup of the type decls in bases for
/// dependent class.
/// \return \a NotFound if no any decls is found, \a FoundNotType if found not a
/// type decl, \a FoundType if only type decls are found.
static UnqualifiedTypeNameLookupResult
lookupUnqualifiedTypeNameInBase(Sema &S, const IdentifierInfo &II,
SourceLocation NameLoc,
const CXXRecordDecl *RD) {
if (!RD->hasDefinition())
return UnqualifiedTypeNameLookupResult::NotFound;
// Look for type decls in base classes.
UnqualifiedTypeNameLookupResult FoundTypeDecl =
UnqualifiedTypeNameLookupResult::NotFound;
for (const auto &Base : RD->bases()) {
const CXXRecordDecl *BaseRD = Base.getType()->getAsCXXRecordDecl();
if (BaseRD) {
} else if (auto *TST = dyn_cast<TemplateSpecializationType>(
Base.getType().getCanonicalType())) {
// Look for type decls in dependent base classes that have known primary
// templates.
if (!TST->isDependentType())
continue;
auto *TD = TST->getTemplateName().getAsTemplateDecl();
if (!TD)
continue;
if (auto *BasePrimaryTemplate =
dyn_cast_or_null<CXXRecordDecl>(TD->getTemplatedDecl())) {
if (BasePrimaryTemplate->getCanonicalDecl() != RD->getCanonicalDecl())
BaseRD = BasePrimaryTemplate;
else if (auto *CTD = dyn_cast<ClassTemplateDecl>(TD)) {
if (const ClassTemplatePartialSpecializationDecl *PS =
CTD->findPartialSpecialization(Base.getType()))
if (PS->getCanonicalDecl() != RD->getCanonicalDecl())
BaseRD = PS;
}
}
}
if (BaseRD) {
for (NamedDecl *ND : BaseRD->lookup(&II)) {
if (!isa<TypeDecl>(ND))
return UnqualifiedTypeNameLookupResult::FoundNonType;
FoundTypeDecl = UnqualifiedTypeNameLookupResult::FoundType;
}
if (FoundTypeDecl == UnqualifiedTypeNameLookupResult::NotFound) {
switch (lookupUnqualifiedTypeNameInBase(S, II, NameLoc, BaseRD)) {
case UnqualifiedTypeNameLookupResult::FoundNonType:
return UnqualifiedTypeNameLookupResult::FoundNonType;
case UnqualifiedTypeNameLookupResult::FoundType:
FoundTypeDecl = UnqualifiedTypeNameLookupResult::FoundType;
break;
case UnqualifiedTypeNameLookupResult::NotFound:
break;
}
}
}
}
return FoundTypeDecl;
}
static ParsedType recoverFromTypeInKnownDependentBase(Sema &S,
const IdentifierInfo &II,
SourceLocation NameLoc) {
// Lookup in the parent class template context, if any.
const CXXRecordDecl *RD = nullptr;
UnqualifiedTypeNameLookupResult FoundTypeDecl =
UnqualifiedTypeNameLookupResult::NotFound;
for (DeclContext *DC = S.CurContext;
DC && FoundTypeDecl == UnqualifiedTypeNameLookupResult::NotFound;
DC = DC->getParent()) {
// Look for type decls in dependent base classes that have known primary
// templates.
RD = dyn_cast<CXXRecordDecl>(DC);
if (RD && RD->getDescribedClassTemplate())
FoundTypeDecl = lookupUnqualifiedTypeNameInBase(S, II, NameLoc, RD);
}
if (FoundTypeDecl != UnqualifiedTypeNameLookupResult::FoundType)
return nullptr;
// We found some types in dependent base classes. Recover as if the user
// wrote 'MyClass::II' instead of 'II', and this implicit typename was
// allowed. We'll fully resolve the lookup during template instantiation.
S.Diag(NameLoc, diag::ext_found_in_dependent_base) << &II;
ASTContext &Context = S.Context;
NestedNameSpecifier NNS(Context.getCanonicalTagType(RD).getTypePtr());
QualType T =
Context.getDependentNameType(ElaboratedTypeKeyword::None, NNS, &II);
CXXScopeSpec SS;
SS.MakeTrivial(Context, NNS, SourceRange(NameLoc));
TypeLocBuilder Builder;
DependentNameTypeLoc DepTL = Builder.push<DependentNameTypeLoc>(T);
DepTL.setNameLoc(NameLoc);
DepTL.setElaboratedKeywordLoc(SourceLocation());
DepTL.setQualifierLoc(SS.getWithLocInContext(Context));
return S.CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
}
ParsedType Sema::getTypeName(const IdentifierInfo &II, SourceLocation NameLoc,
Scope *S, CXXScopeSpec *SS, bool isClassName,
bool HasTrailingDot, ParsedType ObjectTypePtr,
bool IsCtorOrDtorName,
bool WantNontrivialTypeSourceInfo,
bool IsClassTemplateDeductionContext,
ImplicitTypenameContext AllowImplicitTypename,
IdentifierInfo **CorrectedII) {
bool IsImplicitTypename = !isClassName && !IsCtorOrDtorName;
// FIXME: Consider allowing this outside C++1z mode as an extension.
bool AllowDeducedTemplate = IsClassTemplateDeductionContext &&
getLangOpts().CPlusPlus17 && IsImplicitTypename &&
!HasTrailingDot;
// Determine where we will perform name lookup.
DeclContext *LookupCtx = nullptr;
if (ObjectTypePtr) {
QualType ObjectType = ObjectTypePtr.get();
if (ObjectType->isRecordType())
LookupCtx = computeDeclContext(ObjectType);
} else if (SS && SS->isNotEmpty()) {
LookupCtx = computeDeclContext(*SS, false);
if (!LookupCtx) {
if (isDependentScopeSpecifier(*SS)) {
// C++ [temp.res]p3:
// A qualified-id that refers to a type and in which the
// nested-name-specifier depends on a template-parameter (14.6.2)
// shall be prefixed by the keyword typename to indicate that the
// qualified-id denotes a type, forming an
// elaborated-type-specifier (7.1.5.3).
//
// We therefore do not perform any name lookup if the result would
// refer to a member of an unknown specialization.
// In C++2a, in several contexts a 'typename' is not required. Also
// allow this as an extension.
if (IsImplicitTypename) {
if (AllowImplicitTypename == ImplicitTypenameContext::No)
return nullptr;
SourceLocation QualifiedLoc = SS->getRange().getBegin();
// FIXME: Defer the diagnostic after we build the type and use it.
auto DB = DiagCompat(QualifiedLoc, diag_compat::implicit_typename)
<< Context.getDependentNameType(ElaboratedTypeKeyword::None,
SS->getScopeRep(), &II);
if (!getLangOpts().CPlusPlus20)
DB << FixItHint::CreateInsertion(QualifiedLoc, "typename ");
}
// We know from the grammar that this name refers to a type,
// so build a dependent node to describe the type.
if (WantNontrivialTypeSourceInfo)
return ActOnTypenameType(S, SourceLocation(), *SS, II, NameLoc,
(ImplicitTypenameContext)IsImplicitTypename)
.get();
NestedNameSpecifierLoc QualifierLoc = SS->getWithLocInContext(Context);
QualType T = CheckTypenameType(
IsImplicitTypename ? ElaboratedTypeKeyword::Typename
: ElaboratedTypeKeyword::None,
SourceLocation(), QualifierLoc, II, NameLoc);
return ParsedType::make(T);
}
return nullptr;
}
if (!LookupCtx->isDependentContext() &&
RequireCompleteDeclContext(*SS, LookupCtx))
return nullptr;
}
// In the case where we know that the identifier is a class name, we know that
// it is a type declaration (struct, class, union or enum) so we can use tag
// name lookup.
//
// C++ [class.derived]p2 (wrt lookup in a base-specifier): The lookup for
// the component name of the type-name or simple-template-id is type-only.
LookupNameKind Kind = isClassName ? LookupTagName : LookupOrdinaryName;
LookupResult Result(*this, &II, NameLoc, Kind);
if (LookupCtx) {
// Perform "qualified" name lookup into the declaration context we
// computed, which is either the type of the base of a member access
// expression or the declaration context associated with a prior
// nested-name-specifier.
LookupQualifiedName(Result, LookupCtx);
if (ObjectTypePtr && Result.empty()) {
// C++ [basic.lookup.classref]p3:
// If the unqualified-id is ~type-name, the type-name is looked up
// in the context of the entire postfix-expression. If the type T of
// the object expression is of a class type C, the type-name is also
// looked up in the scope of class C. At least one of the lookups shall
// find a name that refers to (possibly cv-qualified) T.
LookupName(Result, S);
}
} else {
// Perform unqualified name lookup.
LookupName(Result, S);
// For unqualified lookup in a class template in MSVC mode, look into
// dependent base classes where the primary class template is known.
if (Result.empty() && getLangOpts().MSVCCompat && (!SS || SS->isEmpty())) {
if (ParsedType TypeInBase =
recoverFromTypeInKnownDependentBase(*this, II, NameLoc))
return TypeInBase;
}
}
NamedDecl *IIDecl = nullptr;
UsingShadowDecl *FoundUsingShadow = nullptr;
switch (Result.getResultKind()) {
case LookupResultKind::NotFound:
if (CorrectedII) {
TypeNameValidatorCCC CCC(/*AllowInvalid=*/true, isClassName,
AllowDeducedTemplate);
TypoCorrection Correction =
CorrectTypo(Result.getLookupNameInfo(), Kind, S, SS, CCC,
CorrectTypoKind::ErrorRecovery);
IdentifierInfo *NewII = Correction.getCorrectionAsIdentifierInfo();
TemplateTy Template;
bool MemberOfUnknownSpecialization;
UnqualifiedId TemplateName;
TemplateName.setIdentifier(NewII, NameLoc);
NestedNameSpecifier NNS = Correction.getCorrectionSpecifier();
CXXScopeSpec NewSS, *NewSSPtr = SS;
if (SS && NNS) {
NewSS.MakeTrivial(Context, NNS, SourceRange(NameLoc));
NewSSPtr = &NewSS;
}
if (Correction && (NNS || NewII != &II) &&
// Ignore a correction to a template type as the to-be-corrected
// identifier is not a template (typo correction for template names
// is handled elsewhere).
!(getLangOpts().CPlusPlus && NewSSPtr &&
isTemplateName(S, *NewSSPtr, false, TemplateName, nullptr, false,
Template, MemberOfUnknownSpecialization))) {
ParsedType Ty = getTypeName(*NewII, NameLoc, S, NewSSPtr,
isClassName, HasTrailingDot, ObjectTypePtr,
IsCtorOrDtorName,
WantNontrivialTypeSourceInfo,
IsClassTemplateDeductionContext);
if (Ty) {
diagnoseTypo(Correction,
PDiag(diag::err_unknown_type_or_class_name_suggest)
<< Result.getLookupName() << isClassName);
if (SS && NNS)
SS->MakeTrivial(Context, NNS, SourceRange(NameLoc));
*CorrectedII = NewII;
return Ty;
}
}
}
Result.suppressDiagnostics();
return nullptr;
case LookupResultKind::NotFoundInCurrentInstantiation:
if (AllowImplicitTypename == ImplicitTypenameContext::Yes) {
QualType T = Context.getDependentNameType(ElaboratedTypeKeyword::None,
SS->getScopeRep(), &II);
TypeLocBuilder TLB;
DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(T);
TL.setElaboratedKeywordLoc(SourceLocation());
TL.setQualifierLoc(SS->getWithLocInContext(Context));
TL.setNameLoc(NameLoc);
return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
}
[[fallthrough]];
case LookupResultKind::FoundOverloaded:
case LookupResultKind::FoundUnresolvedValue:
Result.suppressDiagnostics();
return nullptr;
case LookupResultKind::Ambiguous:
// Recover from type-hiding ambiguities by hiding the type. We'll
// do the lookup again when looking for an object, and we can
// diagnose the error then. If we don't do this, then the error
// about hiding the type will be immediately followed by an error
// that only makes sense if the identifier was treated like a type.
if (Result.getAmbiguityKind() == LookupAmbiguityKind::AmbiguousTagHiding) {
Result.suppressDiagnostics();
return nullptr;
}
// Look to see if we have a type anywhere in the list of results.
for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end();
Res != ResEnd; ++Res) {
NamedDecl *RealRes = (*Res)->getUnderlyingDecl();
if (isa<TypeDecl, ObjCInterfaceDecl, UnresolvedUsingIfExistsDecl>(
RealRes) ||
(AllowDeducedTemplate && getAsTypeTemplateDecl(RealRes))) {
if (!IIDecl ||
// Make the selection of the recovery decl deterministic.
RealRes->getLocation() < IIDecl->getLocation()) {
IIDecl = RealRes;
FoundUsingShadow = dyn_cast<UsingShadowDecl>(*Res);
}
}
}
if (!IIDecl) {
// None of the entities we found is a type, so there is no way
// to even assume that the result is a type. In this case, don't
// complain about the ambiguity. The parser will either try to
// perform this lookup again (e.g., as an object name), which
// will produce the ambiguity, or will complain that it expected
// a type name.
Result.suppressDiagnostics();
return nullptr;
}
// We found a type within the ambiguous lookup; diagnose the
// ambiguity and then return that type. This might be the right
// answer, or it might not be, but it suppresses any attempt to
// perform the name lookup again.
break;
case LookupResultKind::Found:
IIDecl = Result.getFoundDecl();
FoundUsingShadow = dyn_cast<UsingShadowDecl>(*Result.begin());
break;
}
assert(IIDecl && "Didn't find decl");
TypeLocBuilder TLB;
if (TypeDecl *TD = dyn_cast<TypeDecl>(IIDecl)) {
checkTypeDeclType(LookupCtx,
IsImplicitTypename ? DiagCtorKind::Implicit
: DiagCtorKind::None,
TD, NameLoc);
QualType T;
if (FoundUsingShadow) {
T = Context.getUsingType(ElaboratedTypeKeyword::None,
SS ? SS->getScopeRep() : std::nullopt,
FoundUsingShadow);
if (!WantNontrivialTypeSourceInfo)
return ParsedType::make(T);
TLB.push<UsingTypeLoc>(T).set(/*ElaboratedKeywordLoc=*/SourceLocation(),
SS ? SS->getWithLocInContext(Context)
: NestedNameSpecifierLoc(),
NameLoc);
} else if (auto *Tag = dyn_cast<TagDecl>(TD)) {
T = Context.getTagType(ElaboratedTypeKeyword::None,
SS ? SS->getScopeRep() : std::nullopt, Tag,
/*OwnsTag=*/false);
if (!WantNontrivialTypeSourceInfo)
return ParsedType::make(T);
auto TL = TLB.push<TagTypeLoc>(T);
TL.setElaboratedKeywordLoc(SourceLocation());
TL.setQualifierLoc(SS ? SS->getWithLocInContext(Context)
: NestedNameSpecifierLoc());
TL.setNameLoc(NameLoc);
} else if (auto *TN = dyn_cast<TypedefNameDecl>(TD);
TN && !isa<ObjCTypeParamDecl>(TN)) {
T = Context.getTypedefType(ElaboratedTypeKeyword::None,
SS ? SS->getScopeRep() : std::nullopt, TN);
if (!WantNontrivialTypeSourceInfo)
return ParsedType::make(T);
TLB.push<TypedefTypeLoc>(T).set(
/*ElaboratedKeywordLoc=*/SourceLocation(),
SS ? SS->getWithLocInContext(Context) : NestedNameSpecifierLoc(),
NameLoc);
} else if (auto *UD = dyn_cast<UnresolvedUsingTypenameDecl>(TD)) {
T = Context.getUnresolvedUsingType(ElaboratedTypeKeyword::None,
SS ? SS->getScopeRep() : std::nullopt,
UD);
if (!WantNontrivialTypeSourceInfo)
return ParsedType::make(T);
TLB.push<UnresolvedUsingTypeLoc>(T).set(
/*ElaboratedKeywordLoc=*/SourceLocation(),
SS ? SS->getWithLocInContext(Context) : NestedNameSpecifierLoc(),
NameLoc);
} else {
T = Context.getTypeDeclType(TD);
if (!WantNontrivialTypeSourceInfo)
return ParsedType::make(T);
if (isa<ObjCTypeParamType>(T))
TLB.push<ObjCTypeParamTypeLoc>(T).setNameLoc(NameLoc);
else
TLB.pushTypeSpec(T).setNameLoc(NameLoc);
}
return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
}
if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(IIDecl)) {
(void)DiagnoseUseOfDecl(IDecl, NameLoc);
if (!HasTrailingDot) {
// FIXME: Support UsingType for this case.
QualType T = Context.getObjCInterfaceType(IDecl);
if (!WantNontrivialTypeSourceInfo)
return ParsedType::make(T);
auto TL = TLB.push<ObjCInterfaceTypeLoc>(T);
TL.setNameLoc(NameLoc);
// FIXME: Pass in this source location.
TL.setNameEndLoc(NameLoc);
return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
}
} else if (auto *UD = dyn_cast<UnresolvedUsingIfExistsDecl>(IIDecl)) {
(void)DiagnoseUseOfDecl(UD, NameLoc);
// Recover with 'int'
return ParsedType::make(Context.IntTy);
} else if (AllowDeducedTemplate) {
if (auto *TD = getAsTypeTemplateDecl(IIDecl)) {
assert(!FoundUsingShadow || FoundUsingShadow->getTargetDecl() == TD);
// FIXME: Support UsingType here.
TemplateName Template = Context.getQualifiedTemplateName(
SS ? SS->getScopeRep() : std::nullopt, /*TemplateKeyword=*/false,
FoundUsingShadow ? TemplateName(FoundUsingShadow) : TemplateName(TD));
QualType T = Context.getDeducedTemplateSpecializationType(
ElaboratedTypeKeyword::None, Template, QualType(), false);
auto TL = TLB.push<DeducedTemplateSpecializationTypeLoc>(T);
TL.setElaboratedKeywordLoc(SourceLocation());
TL.setNameLoc(NameLoc);
TL.setQualifierLoc(SS ? SS->getWithLocInContext(Context)
: NestedNameSpecifierLoc());
return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
}
}
// As it's not plausibly a type, suppress diagnostics.
Result.suppressDiagnostics();
return nullptr;
}
// Builds a fake NNS for the given decl context.
static NestedNameSpecifier
synthesizeCurrentNestedNameSpecifier(ASTContext &Context, DeclContext *DC) {
for (;; DC = DC->getLookupParent()) {
DC = DC->getPrimaryContext();
auto *ND = dyn_cast<NamespaceDecl>(DC);
if (ND && !ND->isInline() && !ND->isAnonymousNamespace())
return NestedNameSpecifier(Context, ND, std::nullopt);
if (auto *RD = dyn_cast<CXXRecordDecl>(DC))
return NestedNameSpecifier(Context.getCanonicalTagType(RD)->getTypePtr());
if (isa<TranslationUnitDecl>(DC))
return NestedNameSpecifier::getGlobal();
}
llvm_unreachable("something isn't in TU scope?");
}
/// Find the parent class with dependent bases of the innermost enclosing method
/// context. Do not look for enclosing CXXRecordDecls directly, or we will end
/// up allowing unqualified dependent type names at class-level, which MSVC
/// correctly rejects.
static const CXXRecordDecl *
findRecordWithDependentBasesOfEnclosingMethod(const DeclContext *DC) {
for (; DC && DC->isDependentContext(); DC = DC->getLookupParent()) {
DC = DC->getPrimaryContext();
if (const auto *MD = dyn_cast<CXXMethodDecl>(DC))
if (MD->getParent()->hasAnyDependentBases())
return MD->getParent();
}
return nullptr;
}
ParsedType Sema::ActOnMSVCUnknownTypeName(const IdentifierInfo &II,
SourceLocation NameLoc,
bool IsTemplateTypeArg) {
assert(getLangOpts().MSVCCompat && "shouldn't be called in non-MSVC mode");
NestedNameSpecifier NNS = std::nullopt;
if (IsTemplateTypeArg && getCurScope()->isTemplateParamScope()) {
// If we weren't able to parse a default template argument, delay lookup
// until instantiation time by making a non-dependent DependentTypeName. We
// pretend we saw a NestedNameSpecifier referring to the current scope, and
// lookup is retried.
// FIXME: This hurts our diagnostic quality, since we get errors like "no
// type named 'Foo' in 'current_namespace'" when the user didn't write any
// name specifiers.
NNS = synthesizeCurrentNestedNameSpecifier(Context, CurContext);
Diag(NameLoc, diag::ext_ms_delayed_template_argument) << &II;
} else if (const CXXRecordDecl *RD =
findRecordWithDependentBasesOfEnclosingMethod(CurContext)) {
// Build a DependentNameType that will perform lookup into RD at
// instantiation time.
NNS = NestedNameSpecifier(Context.getCanonicalTagType(RD)->getTypePtr());
// Diagnose that this identifier was undeclared, and retry the lookup during
// template instantiation.
Diag(NameLoc, diag::ext_undeclared_unqual_id_with_dependent_base) << &II
<< RD;
} else {
// This is not a situation that we should recover from.
return ParsedType();
}
QualType T =
Context.getDependentNameType(ElaboratedTypeKeyword::None, NNS, &II);
// Build type location information. We synthesized the qualifier, so we have
// to build a fake NestedNameSpecifierLoc.
NestedNameSpecifierLocBuilder NNSLocBuilder;
NNSLocBuilder.MakeTrivial(Context, NNS, SourceRange(NameLoc));
NestedNameSpecifierLoc QualifierLoc = NNSLocBuilder.getWithLocInContext(Context);
TypeLocBuilder Builder;
DependentNameTypeLoc DepTL = Builder.push<DependentNameTypeLoc>(T);
DepTL.setNameLoc(NameLoc);
DepTL.setElaboratedKeywordLoc(SourceLocation());
DepTL.setQualifierLoc(QualifierLoc);
return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
}
DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) {
// Do a tag name lookup in this scope.
LookupResult R(*this, &II, SourceLocation(), LookupTagName);
LookupName(R, S, false);
R.suppressDiagnostics();
if (R.getResultKind() == LookupResultKind::Found)
if (const TagDecl *TD = R.getAsSingle<TagDecl>()) {
switch (TD->getTagKind()) {
case TagTypeKind::Struct:
return DeclSpec::TST_struct;
case TagTypeKind::Interface:
return DeclSpec::TST_interface;
case TagTypeKind::Union:
return DeclSpec::TST_union;
case TagTypeKind::Class:
return DeclSpec::TST_class;
case TagTypeKind::Enum:
return DeclSpec::TST_enum;
}
}
return DeclSpec::TST_unspecified;
}
bool Sema::isMicrosoftMissingTypename(const CXXScopeSpec *SS, Scope *S) {
if (!CurContext->isRecord())
return CurContext->isFunctionOrMethod() || S->isFunctionPrototypeScope();
switch (SS->getScopeRep().getKind()) {
case NestedNameSpecifier::Kind::MicrosoftSuper:
return true;
case NestedNameSpecifier::Kind::Type: {
QualType T(SS->getScopeRep().getAsType(), 0);
for (const auto &Base : cast<CXXRecordDecl>(CurContext)->bases())
if (Context.hasSameUnqualifiedType(T, Base.getType()))
return true;
[[fallthrough]];
}
default:
return S->isFunctionPrototypeScope();
}
}
void Sema::DiagnoseUnknownTypeName(IdentifierInfo *&II,
SourceLocation IILoc,
Scope *S,
CXXScopeSpec *SS,
ParsedType &SuggestedType,
bool IsTemplateName) {
// Don't report typename errors for editor placeholders.
if (II->isEditorPlaceholder())
return;
// We don't have anything to suggest (yet).
SuggestedType = nullptr;
// There may have been a typo in the name of the type. Look up typo
// results, in case we have something that we can suggest.
TypeNameValidatorCCC CCC(/*AllowInvalid=*/false, /*WantClass=*/false,
/*AllowTemplates=*/IsTemplateName,
/*AllowNonTemplates=*/!IsTemplateName);
if (TypoCorrection Corrected =
CorrectTypo(DeclarationNameInfo(II, IILoc), LookupOrdinaryName, S, SS,
CCC, CorrectTypoKind::ErrorRecovery)) {
// FIXME: Support error recovery for the template-name case.
bool CanRecover = !IsTemplateName;
if (Corrected.isKeyword()) {
// We corrected to a keyword.
diagnoseTypo(Corrected,
PDiag(IsTemplateName ? diag::err_no_template_suggest
: diag::err_unknown_typename_suggest)
<< II);
II = Corrected.getCorrectionAsIdentifierInfo();
} else {
// We found a similarly-named type or interface; suggest that.
if (!SS || !SS->isSet()) {
diagnoseTypo(Corrected,
PDiag(IsTemplateName ? diag::err_no_template_suggest
: diag::err_unknown_typename_suggest)
<< II, CanRecover);
} else if (DeclContext *DC = computeDeclContext(*SS, false)) {
std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
bool DroppedSpecifier =
Corrected.WillReplaceSpecifier() && II->getName() == CorrectedStr;
diagnoseTypo(Corrected,
PDiag(IsTemplateName
? diag::err_no_member_template_suggest
: diag::err_unknown_nested_typename_suggest)
<< II << DC << DroppedSpecifier << SS->getRange(),
CanRecover);
} else {
llvm_unreachable("could not have corrected a typo here");
}
if (!CanRecover)
return;
CXXScopeSpec tmpSS;
if (Corrected.getCorrectionSpecifier())
tmpSS.MakeTrivial(Context, Corrected.getCorrectionSpecifier(),
SourceRange(IILoc));
// FIXME: Support class template argument deduction here.
SuggestedType =
getTypeName(*Corrected.getCorrectionAsIdentifierInfo(), IILoc, S,
tmpSS.isSet() ? &tmpSS : SS, false, false, nullptr,
/*IsCtorOrDtorName=*/false,
/*WantNontrivialTypeSourceInfo=*/true);
}
return;
}
if (getLangOpts().CPlusPlus && !IsTemplateName) {
// See if II is a class template that the user forgot to pass arguments to.
UnqualifiedId Name;
Name.setIdentifier(II, IILoc);
CXXScopeSpec EmptySS;
TemplateTy TemplateResult;
bool MemberOfUnknownSpecialization;
if (isTemplateName(S, SS ? *SS : EmptySS, /*hasTemplateKeyword=*/false,
Name, nullptr, true, TemplateResult,
MemberOfUnknownSpecialization) == TNK_Type_template) {
diagnoseMissingTemplateArguments(TemplateResult.get(), IILoc);
return;
}
}
// FIXME: Should we move the logic that tries to recover from a missing tag
// (struct, union, enum) from Parser::ParseImplicitInt here, instead?
if (!SS || (!SS->isSet() && !SS->isInvalid()))
Diag(IILoc, IsTemplateName ? diag::err_no_template
: diag::err_unknown_typename)
<< II;
else if (DeclContext *DC = computeDeclContext(*SS, false))
Diag(IILoc, IsTemplateName ? diag::err_no_member_template
: diag::err_typename_nested_not_found)
<< II << DC << SS->getRange();
else if (SS->isValid() && SS->getScopeRep().containsErrors()) {
SuggestedType =
ActOnTypenameType(S, SourceLocation(), *SS, *II, IILoc).get();
} else if (isDependentScopeSpecifier(*SS)) {
unsigned DiagID = diag::err_typename_missing;
if (getLangOpts().MSVCCompat && isMicrosoftMissingTypename(SS, S))
DiagID = diag::ext_typename_missing;
SuggestedType =
ActOnTypenameType(S, SourceLocation(), *SS, *II, IILoc).get();
Diag(SS->getRange().getBegin(), DiagID)
<< GetTypeFromParser(SuggestedType)
<< SourceRange(SS->getRange().getBegin(), IILoc)
<< FixItHint::CreateInsertion(SS->getRange().getBegin(), "typename ");
} else {
assert(SS && SS->isInvalid() &&
"Invalid scope specifier has already been diagnosed");
}
}
/// Determine whether the given result set contains either a type name
/// or
static bool isResultTypeOrTemplate(LookupResult &R, const Token &NextToken) {
bool CheckTemplate = R.getSema().getLangOpts().CPlusPlus &&
NextToken.is(tok::less);
for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; ++I) {
if (isa<TypeDecl>(*I) || isa<ObjCInterfaceDecl>(*I))
return true;
if (CheckTemplate && isa<TemplateDecl>(*I))
return true;
}
return false;
}
static bool isTagTypeWithMissingTag(Sema &SemaRef, LookupResult &Result,
Scope *S, CXXScopeSpec &SS,
IdentifierInfo *&Name,
SourceLocation NameLoc) {
LookupResult R(SemaRef, Name, NameLoc, Sema::LookupTagName);
SemaRef.LookupParsedName(R, S, &SS, /*ObjectType=*/QualType());
if (TagDecl *Tag = R.getAsSingle<TagDecl>()) {
StringRef FixItTagName;
switch (Tag->getTagKind()) {
case TagTypeKind::Class:
FixItTagName = "class ";
break;
case TagTypeKind::Enum:
FixItTagName = "enum ";
break;
case TagTypeKind::Struct:
FixItTagName = "struct ";
break;
case TagTypeKind::Interface:
FixItTagName = "__interface ";
break;
case TagTypeKind::Union:
FixItTagName = "union ";
break;
}
StringRef TagName = FixItTagName.drop_back();
SemaRef.Diag(NameLoc, diag::err_use_of_tag_name_without_tag)
<< Name << TagName << SemaRef.getLangOpts().CPlusPlus
<< FixItHint::CreateInsertion(NameLoc, FixItTagName);
for (LookupResult::iterator I = Result.begin(), IEnd = Result.end();
I != IEnd; ++I)
SemaRef.Diag((*I)->getLocation(), diag::note_decl_hiding_tag_type)
<< Name << TagName;
// Replace lookup results with just the tag decl.
Result.clear(Sema::LookupTagName);
SemaRef.LookupParsedName(Result, S, &SS, /*ObjectType=*/QualType());
return true;
}
return false;
}
Sema::NameClassification Sema::ClassifyName(Scope *S, CXXScopeSpec &SS,
IdentifierInfo *&Name,
SourceLocation NameLoc,
const Token &NextToken,
CorrectionCandidateCallback *CCC) {
DeclarationNameInfo NameInfo(Name, NameLoc);
ObjCMethodDecl *CurMethod = getCurMethodDecl();
assert(NextToken.isNot(tok::coloncolon) &&
"parse nested name specifiers before calling ClassifyName");
if (getLangOpts().CPlusPlus && SS.isSet() &&
isCurrentClassName(*Name, S, &SS)) {
// Per [class.qual]p2, this names the constructors of SS, not the
// injected-class-name. We don't have a classification for that.
// There's not much point caching this result, since the parser
// will reject it later.
return NameClassification::Unknown();
}
LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
LookupParsedName(Result, S, &SS, /*ObjectType=*/QualType(),
/*AllowBuiltinCreation=*/!CurMethod);
if (SS.isInvalid())
return NameClassification::Error();
// For unqualified lookup in a class template in MSVC mode, look into
// dependent base classes where the primary class template is known.
if (Result.empty() && SS.isEmpty() && getLangOpts().MSVCCompat) {
if (ParsedType TypeInBase =
recoverFromTypeInKnownDependentBase(*this, *Name, NameLoc))
return TypeInBase;
}
// Perform lookup for Objective-C instance variables (including automatically
// synthesized instance variables), if we're in an Objective-C method.
// FIXME: This lookup really, really needs to be folded in to the normal
// unqualified lookup mechanism.
if (SS.isEmpty() && CurMethod && !isResultTypeOrTemplate(Result, NextToken)) {
DeclResult Ivar = ObjC().LookupIvarInObjCMethod(Result, S, Name);
if (Ivar.isInvalid())
return NameClassification::Error();
if (Ivar.isUsable())
return NameClassification::NonType(cast<NamedDecl>(Ivar.get()));
// We defer builtin creation until after ivar lookup inside ObjC methods.
if (Result.empty())
LookupBuiltin(Result);
}
bool SecondTry = false;
bool IsFilteredTemplateName = false;
Corrected:
switch (Result.getResultKind()) {
case LookupResultKind::NotFound:
// If an unqualified-id is followed by a '(', then we have a function
// call.
if (SS.isEmpty() && NextToken.is(tok::l_paren)) {
// In C++, this is an ADL-only call.
// FIXME: Reference?
if (getLangOpts().CPlusPlus)
return NameClassification::UndeclaredNonType();
// C90 6.3.2.2:
// If the expression that precedes the parenthesized argument list in a
// function call consists solely of an identifier, and if no
// declaration is visible for this identifier, the identifier is
// implicitly declared exactly as if, in the innermost block containing
// the function call, the declaration
//
// extern int identifier ();
//
// appeared.
//
// We also allow this in C99 as an extension. However, this is not
// allowed in all language modes as functions without prototypes may not
// be supported.
if (getLangOpts().implicitFunctionsAllowed()) {
if (NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *Name, S))
return NameClassification::NonType(D);
}
}
if (getLangOpts().CPlusPlus20 && SS.isEmpty() && NextToken.is(tok::less)) {
// In C++20 onwards, this could be an ADL-only call to a function
// template, and we're required to assume that this is a template name.
//
// FIXME: Find a way to still do typo correction in this case.
TemplateName Template =
Context.getAssumedTemplateName(NameInfo.getName());
return NameClassification::UndeclaredTemplate(Template);
}
// In C, we first see whether there is a tag type by the same name, in
// which case it's likely that the user just forgot to write "enum",
// "struct", or "union".
if (!getLangOpts().CPlusPlus && !SecondTry &&
isTagTypeWithMissingTag(*this, Result, S, SS, Name, NameLoc)) {
break;
}
// Perform typo correction to determine if there is another name that is
// close to this name.
if (!SecondTry && CCC) {
SecondTry = true;
if (TypoCorrection Corrected =
CorrectTypo(Result.getLookupNameInfo(), Result.getLookupKind(), S,
&SS, *CCC, CorrectTypoKind::ErrorRecovery)) {
unsigned UnqualifiedDiag = diag::err_undeclared_var_use_suggest;
unsigned QualifiedDiag = diag::err_no_member_suggest;
NamedDecl *FirstDecl = Corrected.getFoundDecl();
NamedDecl *UnderlyingFirstDecl = Corrected.getCorrectionDecl();
if (getLangOpts().CPlusPlus && NextToken.is(tok::less) &&
UnderlyingFirstDecl && isa<TemplateDecl>(UnderlyingFirstDecl)) {
UnqualifiedDiag = diag::err_no_template_suggest;
QualifiedDiag = diag::err_no_member_template_suggest;
} else if (UnderlyingFirstDecl &&
(isa<TypeDecl>(UnderlyingFirstDecl) ||
isa<ObjCInterfaceDecl>(UnderlyingFirstDecl) ||
isa<ObjCCompatibleAliasDecl>(UnderlyingFirstDecl))) {
UnqualifiedDiag = diag::err_unknown_typename_suggest;
QualifiedDiag = diag::err_unknown_nested_typename_suggest;
}
if (SS.isEmpty()) {
diagnoseTypo(Corrected, PDiag(UnqualifiedDiag) << Name);
} else {// FIXME: is this even reachable? Test it.
std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
Name->getName() == CorrectedStr;
diagnoseTypo(Corrected, PDiag(QualifiedDiag)
<< Name << computeDeclContext(SS, false)
<< DroppedSpecifier << SS.getRange());
}
// Update the name, so that the caller has the new name.
Name = Corrected.getCorrectionAsIdentifierInfo();
// Typo correction corrected to a keyword.
if (Corrected.isKeyword())
return Name;
// Also update the LookupResult...
// FIXME: This should probably go away at some point
Result.clear();
Result.setLookupName(Corrected.getCorrection());
if (FirstDecl)
Result.addDecl(FirstDecl);
// If we found an Objective-C instance variable, let
// LookupInObjCMethod build the appropriate expression to
// reference the ivar.
// FIXME: This is a gross hack.
if (ObjCIvarDecl *Ivar = Result.getAsSingle<ObjCIvarDecl>()) {
DeclResult R =
ObjC().LookupIvarInObjCMethod(Result, S, Ivar->getIdentifier());
if (R.isInvalid())
return NameClassification::Error();
if (R.isUsable())
return NameClassification::NonType(Ivar);
}
goto Corrected;
}
}
// We failed to correct; just fall through and let the parser deal with it.
Result.suppressDiagnostics();
return NameClassification::Unknown();
case LookupResultKind::NotFoundInCurrentInstantiation: {
// We performed name lookup into the current instantiation, and there were
// dependent bases, so we treat this result the same way as any other
// dependent nested-name-specifier.
// C++ [temp.res]p2:
// A name used in a template declaration or definition and that is
// dependent on a template-parameter is assumed not to name a type
// unless the applicable name lookup finds a type name or the name is
// qualified by the keyword typename.
//
// FIXME: If the next token is '<', we might want to ask the parser to
// perform some heroics to see if we actually have a
// template-argument-list, which would indicate a missing 'template'
// keyword here.
return NameClassification::DependentNonType();
}
case LookupResultKind::Found:
case LookupResultKind::FoundOverloaded:
case LookupResultKind::FoundUnresolvedValue:
break;
case LookupResultKind::Ambiguous:
if (getLangOpts().CPlusPlus && NextToken.is(tok::less) &&
hasAnyAcceptableTemplateNames(Result, /*AllowFunctionTemplates=*/true,
/*AllowDependent=*/false)) {
// C++ [temp.local]p3:
// A lookup that finds an injected-class-name (10.2) can result in an
// ambiguity in certain cases (for example, if it is found in more than
// one base class). If all of the injected-class-names that are found
// refer to specializations of the same class template, and if the name
// is followed by a template-argument-list, the reference refers to the
// class template itself and not a specialization thereof, and is not
// ambiguous.
//
// This filtering can make an ambiguous result into an unambiguous one,
// so try again after filtering out template names.
FilterAcceptableTemplateNames(Result);
if (!Result.isAmbiguous()) {
IsFilteredTemplateName = true;
break;
}
}
// Diagnose the ambiguity and return an error.
return NameClassification::Error();
}
if (getLangOpts().CPlusPlus && NextToken.is(tok::less) &&
(IsFilteredTemplateName ||
hasAnyAcceptableTemplateNames(
Result, /*AllowFunctionTemplates=*/true,
/*AllowDependent=*/false,
/*AllowNonTemplateFunctions*/ SS.isEmpty() &&
getLangOpts().CPlusPlus20))) {
// C++ [temp.names]p3:
// After name lookup (3.4) finds that a name is a template-name or that
// an operator-function-id or a literal- operator-id refers to a set of
// overloaded functions any member of which is a function template if
// this is followed by a <, the < is always taken as the delimiter of a
// template-argument-list and never as the less-than operator.
// C++2a [temp.names]p2:
// A name is also considered to refer to a template if it is an
// unqualified-id followed by a < and name lookup finds either one
// or more functions or finds nothing.
if (!IsFilteredTemplateName)
FilterAcceptableTemplateNames(Result);
bool IsFunctionTemplate;
bool IsVarTemplate;
TemplateName Template;
if (Result.end() - Result.begin() > 1) {
IsFunctionTemplate = true;
Template = Context.getOverloadedTemplateName(Result.begin(),
Result.end());
} else if (!Result.empty()) {
auto *TD = cast<TemplateDecl>(getAsTemplateNameDecl(
*Result.begin(), /*AllowFunctionTemplates=*/true,
/*AllowDependent=*/false));
IsFunctionTemplate = isa<FunctionTemplateDecl>(TD);
IsVarTemplate = isa<VarTemplateDecl>(TD);
UsingShadowDecl *FoundUsingShadow =
dyn_cast<UsingShadowDecl>(*Result.begin());
assert(!FoundUsingShadow ||
TD == cast<TemplateDecl>(FoundUsingShadow->getTargetDecl()));
Template = Context.getQualifiedTemplateName(
SS.getScopeRep(),
/*TemplateKeyword=*/false,
FoundUsingShadow ? TemplateName(FoundUsingShadow) : TemplateName(TD));
} else {
// All results were non-template functions. This is a function template
// name.
IsFunctionTemplate = true;
Template = Context.getAssumedTemplateName(NameInfo.getName());
}
if (IsFunctionTemplate) {
// Function templates always go through overload resolution, at which
// point we'll perform the various checks (e.g., accessibility) we need
// to based on which function we selected.
Result.suppressDiagnostics();
return NameClassification::FunctionTemplate(Template);
}
return IsVarTemplate ? NameClassification::VarTemplate(Template)
: NameClassification::TypeTemplate(Template);
}
auto BuildTypeFor = [&](TypeDecl *Type, NamedDecl *Found) {
QualType T;
TypeLocBuilder TLB;
if (const auto *USD = dyn_cast<UsingShadowDecl>(Found)) {
T = Context.getUsingType(ElaboratedTypeKeyword::None, SS.getScopeRep(),
USD);
TLB.push<UsingTypeLoc>(T).set(/*ElaboratedKeywordLoc=*/SourceLocation(),
SS.getWithLocInContext(Context), NameLoc);
} else {
T = Context.getTypeDeclType(ElaboratedTypeKeyword::None, SS.getScopeRep(),
Type);
if (isa<TagType>(T)) {
auto TTL = TLB.push<TagTypeLoc>(T);
TTL.setElaboratedKeywordLoc(SourceLocation());
TTL.setQualifierLoc(SS.getWithLocInContext(Context));
TTL.setNameLoc(NameLoc);
} else if (isa<TypedefType>(T)) {
TLB.push<TypedefTypeLoc>(T).set(
/*ElaboratedKeywordLoc=*/SourceLocation(),
SS.getWithLocInContext(Context), NameLoc);
} else if (isa<UnresolvedUsingType>(T)) {
TLB.push<UnresolvedUsingTypeLoc>(T).set(
/*ElaboratedKeywordLoc=*/SourceLocation(),
SS.getWithLocInContext(Context), NameLoc);
} else {
TLB.pushTypeSpec(T).setNameLoc(NameLoc);
}
}
return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
};
NamedDecl *FirstDecl = (*Result.begin())->getUnderlyingDecl();
if (TypeDecl *Type = dyn_cast<TypeDecl>(FirstDecl)) {
DiagnoseUseOfDecl(Type, NameLoc);
MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
return BuildTypeFor(Type, *Result.begin());
}
ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(FirstDecl);
if (!Class) {
// FIXME: It's unfortunate that we don't have a Type node for handling this.
if (ObjCCompatibleAliasDecl *Alias =
dyn_cast<ObjCCompatibleAliasDecl>(FirstDecl))
Class = Alias->getClassInterface();
}
if (Class) {
DiagnoseUseOfDecl(Class, NameLoc);
if (NextToken.is(tok::period)) {
// Interface. <something> is parsed as a property reference expression.
// Just return "unknown" as a fall-through for now.
Result.suppressDiagnostics();
return NameClassification::Unknown();
}
QualType T = Context.getObjCInterfaceType(Class);
return ParsedType::make(T);
}
if (isa<ConceptDecl>(FirstDecl)) {
// We want to preserve the UsingShadowDecl for concepts.
if (auto *USD = dyn_cast<UsingShadowDecl>(Result.getRepresentativeDecl()))
return NameClassification::Concept(TemplateName(USD));
return NameClassification::Concept(
TemplateName(cast<TemplateDecl>(FirstDecl)));
}
if (auto *EmptyD = dyn_cast<UnresolvedUsingIfExistsDecl>(FirstDecl)) {
(void)DiagnoseUseOfDecl(EmptyD, NameLoc);
return NameClassification::Error();
}
// We can have a type template here if we're classifying a template argument.
if (isa<TemplateDecl>(FirstDecl) && !isa<FunctionTemplateDecl>(FirstDecl) &&
!isa<VarTemplateDecl>(FirstDecl))
return NameClassification::TypeTemplate(
TemplateName(cast<TemplateDecl>(FirstDecl)));
// Check for a tag type hidden by a non-type decl in a few cases where it
// seems likely a type is wanted instead of the non-type that was found.
bool NextIsOp = NextToken.isOneOf(tok::amp, tok::star);
if ((NextToken.is(tok::identifier) ||
(NextIsOp &&
FirstDecl->getUnderlyingDecl()->isFunctionOrFunctionTemplate())) &&
isTagTypeWithMissingTag(*this, Result, S, SS, Name, NameLoc)) {
TypeDecl *Type = Result.getAsSingle<TypeDecl>();
DiagnoseUseOfDecl(Type, NameLoc);
return BuildTypeFor(Type, *Result.begin());
}
// If we already know which single declaration is referenced, just annotate
// that declaration directly. Defer resolving even non-overloaded class
// member accesses, as we need to defer certain access checks until we know
// the context.
bool ADL = UseArgumentDependentLookup(SS, Result, NextToken.is(tok::l_paren));
if (Result.isSingleResult() && !ADL &&
(!FirstDecl->isCXXClassMember() || isa<EnumConstantDecl>(FirstDecl)))
return NameClassification::NonType(Result.getRepresentativeDecl());
// Otherwise, this is an overload set that we will need to resolve later.
Result.suppressDiagnostics();
return NameClassification::OverloadSet(UnresolvedLookupExpr::Create(
Context, Result.getNamingClass(), SS.getWithLocInContext(Context),
Result.getLookupNameInfo(), ADL, Result.begin(), Result.end(),
/*KnownDependent=*/false, /*KnownInstantiationDependent=*/false));
}
ExprResult
Sema::ActOnNameClassifiedAsUndeclaredNonType(IdentifierInfo *Name,
SourceLocation NameLoc) {
assert(getLangOpts().CPlusPlus && "ADL-only call in C?");
CXXScopeSpec SS;
LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
return BuildDeclarationNameExpr(SS, Result, /*ADL=*/true);
}
ExprResult
Sema::ActOnNameClassifiedAsDependentNonType(const CXXScopeSpec &SS,
IdentifierInfo *Name,
SourceLocation NameLoc,
bool IsAddressOfOperand) {
DeclarationNameInfo NameInfo(Name, NameLoc);
return ActOnDependentIdExpression(SS, /*TemplateKWLoc=*/SourceLocation(),
NameInfo, IsAddressOfOperand,
/*TemplateArgs=*/nullptr);
}
ExprResult Sema::ActOnNameClassifiedAsNonType(Scope *S, const CXXScopeSpec &SS,
NamedDecl *Found,
SourceLocation NameLoc,
const Token &NextToken) {
if (getCurMethodDecl() && SS.isEmpty())
if (auto *Ivar = dyn_cast<ObjCIvarDecl>(Found->getUnderlyingDecl()))
return ObjC().BuildIvarRefExpr(S, NameLoc, Ivar);
// Reconstruct the lookup result.
LookupResult Result(*this, Found->getDeclName(), NameLoc, LookupOrdinaryName);
Result.addDecl(Found);
Result.resolveKind();
bool ADL = UseArgumentDependentLookup(SS, Result, NextToken.is(tok::l_paren));
return BuildDeclarationNameExpr(SS, Result, ADL, /*AcceptInvalidDecl=*/true);
}
ExprResult Sema::ActOnNameClassifiedAsOverloadSet(Scope *S, Expr *E) {
// For an implicit class member access, transform the result into a member
// access expression if necessary.
auto *ULE = cast<UnresolvedLookupExpr>(E);
if ((*ULE->decls_begin())->isCXXClassMember()) {
CXXScopeSpec SS;
SS.Adopt(ULE->getQualifierLoc());
// Reconstruct the lookup result.
LookupResult Result(*this, ULE->getName(), ULE->getNameLoc(),
LookupOrdinaryName);
Result.setNamingClass(ULE->getNamingClass());
for (auto I = ULE->decls_begin(), E = ULE->decls_end(); I != E; ++I)
Result.addDecl(*I, I.getAccess());
Result.resolveKind();
return BuildPossibleImplicitMemberExpr(SS, SourceLocation(), Result,
nullptr, S);
}
// Otherwise, this is already in the form we needed, and no further checks
// are necessary.
return ULE;
}
Sema::TemplateNameKindForDiagnostics
Sema::getTemplateNameKindForDiagnostics(TemplateName Name) {
auto *TD = Name.getAsTemplateDecl();
if (!TD)
return TemplateNameKindForDiagnostics::DependentTemplate;
if (isa<ClassTemplateDecl>(TD))
return TemplateNameKindForDiagnostics::ClassTemplate;
if (isa<FunctionTemplateDecl>(TD))
return TemplateNameKindForDiagnostics::FunctionTemplate;
if (isa<VarTemplateDecl>(TD))
return TemplateNameKindForDiagnostics::VarTemplate;
if (isa<TypeAliasTemplateDecl>(TD))
return TemplateNameKindForDiagnostics::AliasTemplate;
if (isa<TemplateTemplateParmDecl>(TD))
return TemplateNameKindForDiagnostics::TemplateTemplateParam;
if (isa<ConceptDecl>(TD))
return TemplateNameKindForDiagnostics::Concept;
return TemplateNameKindForDiagnostics::DependentTemplate;
}
void Sema::PushDeclContext(Scope *S, DeclContext *DC) {
assert(DC->getLexicalParent() == CurContext &&
"The next DeclContext should be lexically contained in the current one.");
CurContext = DC;
S->setEntity(DC);
}
void Sema::PopDeclContext() {
assert(CurContext && "DeclContext imbalance!");
CurContext = CurContext->getLexicalParent();
assert(CurContext && "Popped translation unit!");
}
Sema::SkippedDefinitionContext Sema::ActOnTagStartSkippedDefinition(Scope *S,
Decl *D) {
// Unlike PushDeclContext, the context to which we return is not necessarily
// the containing DC of TD, because the new context will be some pre-existing
// TagDecl definition instead of a fresh one.
auto Result = static_cast<SkippedDefinitionContext>(CurContext);
CurContext = cast<TagDecl>(D)->getDefinition();
assert(CurContext && "skipping definition of undefined tag");
// Start lookups from the parent of the current context; we don't want to look
// into the pre-existing complete definition.
S->setEntity(CurContext->getLookupParent());
return Result;
}
void Sema::ActOnTagFinishSkippedDefinition(SkippedDefinitionContext Context) {
CurContext = static_cast<decltype(CurContext)>(Context);
}
void Sema::EnterDeclaratorContext(Scope *S, DeclContext *DC) {
// C++0x [basic.lookup.unqual]p13:
// A name used in the definition of a static data member of class
// X (after the qualified-id of the static member) is looked up as
// if the name was used in a member function of X.
// C++0x [basic.lookup.unqual]p14:
// If a variable member of a namespace is defined outside of the
// scope of its namespace then any name used in the definition of
// the variable member (after the declarator-id) is looked up as
// if the definition of the variable member occurred in its
// namespace.
// Both of these imply that we should push a scope whose context
// is the semantic context of the declaration. We can't use
// PushDeclContext here because that context is not necessarily
// lexically contained in the current context. Fortunately,
// the containing scope should have the appropriate information.
assert(!S->getEntity() && "scope already has entity");
#ifndef NDEBUG
Scope *Ancestor = S->getParent();
while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent();
assert(Ancestor->getEntity() == CurContext && "ancestor context mismatch");
#endif
CurContext = DC;
S->setEntity(DC);
if (S->getParent()->isTemplateParamScope()) {
// Also set the corresponding entities for all immediately-enclosing
// template parameter scopes.
EnterTemplatedContext(S->getParent(), DC);
}
}
void Sema::ExitDeclaratorContext(Scope *S) {
assert(S->getEntity() == CurContext && "Context imbalance!");
// Switch back to the lexical context. The safety of this is
// enforced by an assert in EnterDeclaratorContext.
Scope *Ancestor = S->getParent();
while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent();
CurContext = Ancestor->getEntity();
// We don't need to do anything with the scope, which is going to
// disappear.
}
void Sema::EnterTemplatedContext(Scope *S, DeclContext *DC) {
assert(S->isTemplateParamScope() &&
"expected to be initializing a template parameter scope");
// C++20 [temp.local]p7:
// In the definition of a member of a class template that appears outside
// of the class template definition, the name of a member of the class
// template hides the name of a template-parameter of any enclosing class
// templates (but not a template-parameter of the member if the member is a
// class or function template).
// C++20 [temp.local]p9:
// In the definition of a class template or in the definition of a member
// of such a template that appears outside of the template definition, for
// each non-dependent base class (13.8.2.1), if the name of the base class
// or the name of a member of the base class is the same as the name of a
// template-parameter, the base class name or member name hides the
// template-parameter name (6.4.10).
//
// This means that a template parameter scope should be searched immediately
// after searching the DeclContext for which it is a template parameter
// scope. For example, for
// template<typename T> template<typename U> template<typename V>
// void N::A<T>::B<U>::f(...)
// we search V then B<U> (and base classes) then U then A<T> (and base
// classes) then T then N then ::.
unsigned ScopeDepth = getTemplateDepth(S);
for (; S && S->isTemplateParamScope(); S = S->getParent(), --ScopeDepth) {
DeclContext *SearchDCAfterScope = DC;
for (; DC; DC = DC->getLookupParent()) {
if (const TemplateParameterList *TPL =
cast<Decl>(DC)->getDescribedTemplateParams()) {
unsigned DCDepth = TPL->getDepth() + 1;
if (DCDepth > ScopeDepth)
continue;
if (ScopeDepth == DCDepth)
SearchDCAfterScope = DC = DC->getLookupParent();
break;
}
}
S->setLookupEntity(SearchDCAfterScope);
}
}
void Sema::ActOnReenterFunctionContext(Scope* S, Decl *D) {
// We assume that the caller has already called
// ActOnReenterTemplateScope so getTemplatedDecl() works.
FunctionDecl *FD = D->getAsFunction();
if (!FD)
return;
// Same implementation as PushDeclContext, but enters the context
// from the lexical parent, rather than the top-level class.
assert(CurContext == FD->getLexicalParent() &&
"The next DeclContext should be lexically contained in the current one.");
CurContext = FD;
S->setEntity(CurContext);
for (unsigned P = 0, NumParams = FD->getNumParams(); P < NumParams; ++P) {
ParmVarDecl *Param = FD->getParamDecl(P);
// If the parameter has an identifier, then add it to the scope
if (Param->getIdentifier()) {
S->AddDecl(Param);
IdResolver.AddDecl(Param);
}
}
}
void Sema::ActOnExitFunctionContext() {
// Same implementation as PopDeclContext, but returns to the lexical parent,
// rather than the top-level class.
assert(CurContext && "DeclContext imbalance!");
CurContext = CurContext->getLexicalParent();
assert(CurContext && "Popped translation unit!");
}
/// Determine whether overloading is allowed for a new function
/// declaration considering prior declarations of the same name.
///
/// This routine determines whether overloading is possible, not
/// whether a new declaration actually overloads a previous one.
/// It will return true in C++ (where overloads are always permitted)
/// or, as a C extension, when either the new declaration or a
/// previous one is declared with the 'overloadable' attribute.
static bool AllowOverloadingOfFunction(const LookupResult &Previous,
ASTContext &Context,
const FunctionDecl *New) {
if (Context.getLangOpts().CPlusPlus || New->hasAttr<OverloadableAttr>())
return true;
// Multiversion function declarations are not overloads in the
// usual sense of that term, but lookup will report that an
// overload set was found if more than one multiversion function
// declaration is present for the same name. It is therefore
// inadequate to assume that some prior declaration(s) had
// the overloadable attribute; checking is required. Since one
// declaration is permitted to omit the attribute, it is necessary
// to check at least two; hence the 'any_of' check below. Note that
// the overloadable attribute is implicitly added to declarations
// that were required to have it but did not.
if (Previous.getResultKind() == LookupResultKind::FoundOverloaded) {
return llvm::any_of(Previous, [](const NamedDecl *ND) {
return ND->hasAttr<OverloadableAttr>();
});
} else if (Previous.getResultKind() == LookupResultKind::Found)
return Previous.getFoundDecl()->hasAttr<OverloadableAttr>();
return false;
}
void Sema::PushOnScopeChains(NamedDecl *D, Scope *S, bool AddToContext) {
// Move up the scope chain until we find the nearest enclosing
// non-transparent context. The declaration will be introduced into this
// scope.
while (S->getEntity() && S->getEntity()->isTransparentContext())
S = S->getParent();
// Add scoped declarations into their context, so that they can be
// found later. Declarations without a context won't be inserted
// into any context.
if (AddToContext)
CurContext->addDecl(D);
// Out-of-line definitions shouldn't be pushed into scope in C++, unless they
// are function-local declarations.
if (getLangOpts().CPlusPlus && D->isOutOfLine() && !S->getFnParent())
return;
// Template instantiations should also not be pushed into scope.
if (isa<FunctionDecl>(D) &&
cast<FunctionDecl>(D)->isFunctionTemplateSpecialization())
return;
if (isa<UsingEnumDecl>(D) && D->getDeclName().isEmpty()) {
S->AddDecl(D);
return;
}
// If this replaces anything in the current scope,
IdentifierResolver::iterator I = IdResolver.begin(D->getDeclName()),
IEnd = IdResolver.end();
for (; I != IEnd; ++I) {
if (S->isDeclScope(*I) && D->declarationReplaces(*I)) {
S->RemoveDecl(*I);
IdResolver.RemoveDecl(*I);
// Should only need to replace one decl.
break;
}
}
S->AddDecl(D);
if (isa<LabelDecl>(D) && !cast<LabelDecl>(D)->isGnuLocal()) {
// Implicitly-generated labels may end up getting generated in an order that
// isn't strictly lexical, which breaks name lookup. Be careful to insert
// the label at the appropriate place in the identifier chain.
for (I = IdResolver.begin(D->getDeclName()); I != IEnd; ++I) {
DeclContext *IDC = (*I)->getLexicalDeclContext()->getRedeclContext();
if (IDC == CurContext) {
if (!S->isDeclScope(*I))
continue;
} else if (IDC->Encloses(CurContext))
break;
}
IdResolver.InsertDeclAfter(I, D);
} else {
IdResolver.AddDecl(D);
}
warnOnReservedIdentifier(D);
}
bool Sema::isDeclInScope(NamedDecl *D, DeclContext *Ctx, Scope *S,
bool AllowInlineNamespace) const {
return IdResolver.isDeclInScope(D, Ctx, S, AllowInlineNamespace);
}
Scope *Sema::getScopeForDeclContext(Scope *S, DeclContext *DC) {
DeclContext *TargetDC = DC->getPrimaryContext();
do {
if (DeclContext *ScopeDC = S->getEntity())
if (ScopeDC->getPrimaryContext() == TargetDC)
return S;
} while ((S = S->getParent()));
return nullptr;
}
static bool isOutOfScopePreviousDeclaration(NamedDecl *,
DeclContext*,
ASTContext&);
void Sema::FilterLookupForScope(LookupResult &R, DeclContext *Ctx, Scope *S,
bool ConsiderLinkage,
bool AllowInlineNamespace) {
LookupResult::Filter F = R.makeFilter();
while (F.hasNext()) {
NamedDecl *D = F.next();
if (isDeclInScope(D, Ctx, S, AllowInlineNamespace))
continue;
if (ConsiderLinkage && isOutOfScopePreviousDeclaration(D, Ctx, Context))
continue;
F.erase();
}
F.done();
}
bool Sema::CheckRedeclarationModuleOwnership(NamedDecl *New, NamedDecl *Old) {
// [module.interface]p7:
// A declaration is attached to a module as follows:
// - If the declaration is a non-dependent friend declaration that nominates a
// function with a declarator-id that is a qualified-id or template-id or that
// nominates a class other than with an elaborated-type-specifier with neither
// a nested-name-specifier nor a simple-template-id, it is attached to the
// module to which the friend is attached ([basic.link]).
if (New->getFriendObjectKind() &&
Old->getOwningModuleForLinkage() != New->getOwningModuleForLinkage()) {
New->setLocalOwningModule(Old->getOwningModule());
makeMergedDefinitionVisible(New);
return false;
}
Module *NewM = New->getOwningModule();
Module *OldM = Old->getOwningModule();
if (NewM && NewM->isPrivateModule())
NewM = NewM->Parent;
if (OldM && OldM->isPrivateModule())
OldM = OldM->Parent;
if (NewM == OldM)
return false;
if (NewM && OldM) {
// A module implementation unit has visibility of the decls in its
// implicitly imported interface.
if (NewM->isModuleImplementation() && OldM == ThePrimaryInterface)
return false;
// Partitions are part of the module, but a partition could import another
// module, so verify that the PMIs agree.
if ((NewM->isModulePartition() || OldM->isModulePartition()) &&
getASTContext().isInSameModule(NewM, OldM))
return false;
}
bool NewIsModuleInterface = NewM && NewM->isNamedModule();
bool OldIsModuleInterface = OldM && OldM->isNamedModule();
if (NewIsModuleInterface || OldIsModuleInterface) {
// C++ Modules TS [basic.def.odr] 6.2/6.7 [sic]:
// if a declaration of D [...] appears in the purview of a module, all
// other such declarations shall appear in the purview of the same module
Diag(New->getLocation(), diag::err_mismatched_owning_module)
<< New
<< NewIsModuleInterface
<< (NewIsModuleInterface ? NewM->getFullModuleName() : "")
<< OldIsModuleInterface
<< (OldIsModuleInterface ? OldM->getFullModuleName() : "");
Diag(Old->getLocation(), diag::note_previous_declaration);
New->setInvalidDecl();
return true;
}
return false;
}
bool Sema::CheckRedeclarationExported(NamedDecl *New, NamedDecl *Old) {
// [module.interface]p1:
// An export-declaration shall inhabit a namespace scope.
//
// So it is meaningless to talk about redeclaration which is not at namespace
// scope.
if (!New->getLexicalDeclContext()
->getNonTransparentContext()
->isFileContext() ||
!Old->getLexicalDeclContext()
->getNonTransparentContext()
->isFileContext())
return false;
bool IsNewExported = New->isInExportDeclContext();
bool IsOldExported = Old->isInExportDeclContext();
// It should be irrevelant if both of them are not exported.
if (!IsNewExported && !IsOldExported)
return false;
if (IsOldExported)
return false;
// If the Old declaration are not attached to named modules
// and the New declaration are attached to global module.
// It should be fine to allow the export since it doesn't change
// the linkage of declarations. See
// https://github.com/llvm/llvm-project/issues/98583 for details.
if (!Old->isInNamedModule() && New->getOwningModule() &&
New->getOwningModule()->isImplicitGlobalModule())
return false;
assert(IsNewExported);
auto Lk = Old->getFormalLinkage();
int S = 0;
if (Lk == Linkage::Internal)
S = 1;
else if (Lk == Linkage::Module)
S = 2;
Diag(New->getLocation(), diag::err_redeclaration_non_exported) << New << S;
Diag(Old->getLocation(), diag::note_previous_declaration);
return true;
}
bool Sema::CheckRedeclarationInModule(NamedDecl *New, NamedDecl *Old) {
if (CheckRedeclarationModuleOwnership(New, Old))
return true;
if (CheckRedeclarationExported(New, Old))
return true;
return false;
}
bool Sema::IsRedefinitionInModule(const NamedDecl *New,
const NamedDecl *Old) const {
assert(getASTContext().isSameEntity(New, Old) &&
"New and Old are not the same definition, we should diagnostic it "
"immediately instead of checking it.");
assert(const_cast<Sema *>(this)->isReachable(New) &&
const_cast<Sema *>(this)->isReachable(Old) &&
"We shouldn't see unreachable definitions here.");
Module *NewM = New->getOwningModule();
Module *OldM = Old->getOwningModule();
// We only checks for named modules here. The header like modules is skipped.
// FIXME: This is not right if we import the header like modules in the module
// purview.
//
// For example, assuming "header.h" provides definition for `D`.
// ```C++
// //--- M.cppm
// export module M;
// import "header.h"; // or #include "header.h" but import it by clang modules
// actually.
//
// //--- Use.cpp
// import M;
// import "header.h"; // or uses clang modules.
// ```
//
// In this case, `D` has multiple definitions in multiple TU (M.cppm and
// Use.cpp) and `D` is attached to a named module `M`. The compiler should
// reject it. But the current implementation couldn't detect the case since we
// don't record the information about the importee modules.
//
// But this might not be painful in practice. Since the design of C++20 Named
// Modules suggests us to use headers in global module fragment instead of
// module purview.
if (NewM && NewM->isHeaderLikeModule())
NewM = nullptr;
if (OldM && OldM->isHeaderLikeModule())
OldM = nullptr;
if (!NewM && !OldM)
return true;
// [basic.def.odr]p14.3
// Each such definition shall not be attached to a named module
// ([module.unit]).
if ((NewM && NewM->isNamedModule()) || (OldM && OldM->isNamedModule()))
return true;
// Then New and Old lives in the same TU if their share one same module unit.
if (NewM)
NewM = NewM->getTopLevelModule();
if (OldM)
OldM = OldM->getTopLevelModule();
return OldM == NewM;
}
static bool isUsingDeclNotAtClassScope(NamedDecl *D) {
if (D->getDeclContext()->isFileContext())
return false;
return isa<UsingShadowDecl>(D) ||
isa<UnresolvedUsingTypenameDecl>(D) ||
isa<UnresolvedUsingValueDecl>(D);
}
/// Removes using shadow declarations not at class scope from the lookup
/// results.
static void RemoveUsingDecls(LookupResult &R) {
LookupResult::Filter F = R.makeFilter();
while (F.hasNext())
if (isUsingDeclNotAtClassScope(F.next()))
F.erase();
F.done();
}
/// Check for this common pattern:
/// @code
/// class S {
/// S(const S&); // DO NOT IMPLEMENT
/// void operator=(const S&); // DO NOT IMPLEMENT
/// };
/// @endcode
static bool IsDisallowedCopyOrAssign(const CXXMethodDecl *D) {
// FIXME: Should check for private access too but access is set after we get
// the decl here.
if (D->doesThisDeclarationHaveABody())
return false;
if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D))
return CD->isCopyConstructor();
return D->isCopyAssignmentOperator();
}
bool Sema::mightHaveNonExternalLinkage(const DeclaratorDecl *D) {
const DeclContext *DC = D->getDeclContext();
while (!DC->isTranslationUnit()) {
if (const RecordDecl *RD = dyn_cast<RecordDecl>(DC)){
if (!RD->hasNameForLinkage())
return true;
}
DC = DC->getParent();
}
return !D->isExternallyVisible();
}
// FIXME: This needs to be refactored; some other isInMainFile users want
// these semantics.
static bool isMainFileLoc(const Sema &S, SourceLocation Loc) {
if (S.TUKind != TU_Complete || S.getLangOpts().IsHeaderFile)
return false;
return S.SourceMgr.isInMainFile(Loc);
}
bool Sema::ShouldWarnIfUnusedFileScopedDecl(const DeclaratorDecl *D) const {
assert(D);
if (D->isInvalidDecl() || D->isUsed() || D->hasAttr<UnusedAttr>())
return false;
// Ignore all entities declared within templates, and out-of-line definitions
// of members of class templates.
if (D->getDeclContext()->isDependentContext() ||
D->getLexicalDeclContext()->isDependentContext())
return false;
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
return false;
// A non-out-of-line declaration of a member specialization was implicitly
// instantiated; it's the out-of-line declaration that we're interested in.
if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
FD->getMemberSpecializationInfo() && !FD->isOutOfLine())
return false;
if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
if (MD->isVirtual() || IsDisallowedCopyOrAssign(MD))
return false;
} else {
// 'static inline' functions are defined in headers; don't warn.
if (FD->isInlined() && !isMainFileLoc(*this, FD->getLocation()))
return false;
}
if (FD->doesThisDeclarationHaveABody() &&
Context.DeclMustBeEmitted(FD))
return false;
} else if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
// Constants and utility variables are defined in headers with internal
// linkage; don't warn. (Unlike functions, there isn't a convenient marker
// like "inline".)
if (!isMainFileLoc(*this, VD->getLocation()))
return false;
if (Context.DeclMustBeEmitted(VD))
return false;
if (VD->isStaticDataMember() &&
VD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
return false;
if (VD->isStaticDataMember() &&
VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
VD->getMemberSpecializationInfo() && !VD->isOutOfLine())
return false;
if (VD->isInline() && !isMainFileLoc(*this, VD->getLocation()))
return false;
} else {
return false;
}
// Only warn for unused decls internal to the translation unit.
// FIXME: This seems like a bogus check; it suppresses -Wunused-function
// for inline functions defined in the main source file, for instance.
return mightHaveNonExternalLinkage(D);
}
void Sema::MarkUnusedFileScopedDecl(const DeclaratorDecl *D) {
if (!D)
return;
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
const FunctionDecl *First = FD->getFirstDecl();
if (FD != First && ShouldWarnIfUnusedFileScopedDecl(First))
return; // First should already be in the vector.
}
if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
const VarDecl *First = VD->getFirstDecl();
if (VD != First && ShouldWarnIfUnusedFileScopedDecl(First))
return; // First should already be in the vector.
}
if (ShouldWarnIfUnusedFileScopedDecl(D))
UnusedFileScopedDecls.push_back(D);
}
static bool ShouldDiagnoseUnusedDecl(const LangOptions &LangOpts,
const NamedDecl *D) {
if (D->isInvalidDecl())
return false;
if (const auto *DD = dyn_cast<DecompositionDecl>(D)) {
// For a decomposition declaration, warn if none of the bindings are
// referenced, instead of if the variable itself is referenced (which
// it is, by the bindings' expressions).
bool IsAllIgnored = true;
for (const auto *BD : DD->bindings()) {
if (BD->isReferenced())
return false;
IsAllIgnored = IsAllIgnored && (BD->isPlaceholderVar(LangOpts) ||
BD->hasAttr<UnusedAttr>());
}
if (IsAllIgnored)
return false;
} else if (!D->getDeclName()) {
return false;
} else if (D->isReferenced() || D->isUsed()) {
return false;
}
if (D->isPlaceholderVar(LangOpts))
return false;
if (D->hasAttr<UnusedAttr>() || D->hasAttr<ObjCPreciseLifetimeAttr>() ||
D->hasAttr<CleanupAttr>())
return false;
if (isa<LabelDecl>(D))
return true;
// Except for labels, we only care about unused decls that are local to
// functions.
bool WithinFunction = D->getDeclContext()->isFunctionOrMethod();
if (const auto *R = dyn_cast<CXXRecordDecl>(D->getDeclContext()))
// For dependent types, the diagnostic is deferred.
WithinFunction =
WithinFunction || (R->isLocalClass() && !R->isDependentType());
if (!WithinFunction)
return false;
if (isa<TypedefNameDecl>(D))
return true;
// White-list anything that isn't a local variable.
if (!isa<VarDecl>(D) || isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D))
return false;
// Types of valid local variables should be complete, so this should succeed.
if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
const Expr *Init = VD->getInit();
if (const auto *Cleanups = dyn_cast_if_present<ExprWithCleanups>(Init))
Init = Cleanups->getSubExpr();
const auto *Ty = VD->getType().getTypePtr();
// Only look at the outermost level of typedef.
if (const TypedefType *TT = Ty->getAs<TypedefType>()) {
// Allow anything marked with __attribute__((unused)).
if (TT->getDecl()->hasAttr<UnusedAttr>())
return false;
}
// Warn for reference variables whose initializtion performs lifetime
// extension.
if (const auto *MTE = dyn_cast_if_present<MaterializeTemporaryExpr>(Init);
MTE && MTE->getExtendingDecl()) {
Ty = VD->getType().getNonReferenceType().getTypePtr();
Init = MTE->getSubExpr()->IgnoreImplicitAsWritten();
}
// If we failed to complete the type for some reason, or if the type is
// dependent, don't diagnose the variable.
if (Ty->isIncompleteType() || Ty->isDependentType())
return false;
// Look at the element type to ensure that the warning behaviour is
// consistent for both scalars and arrays.
Ty = Ty->getBaseElementTypeUnsafe();
if (const TagDecl *Tag = Ty->getAsTagDecl()) {
if (Tag->hasAttr<UnusedAttr>())
return false;
if (const auto *RD = dyn_cast<CXXRecordDecl>(Tag)) {
if (!RD->hasTrivialDestructor() && !RD->hasAttr<WarnUnusedAttr>())
return false;
if (Init) {
const auto *Construct =
dyn_cast<CXXConstructExpr>(Init->IgnoreImpCasts());
if (Construct && !Construct->isElidable()) {
const CXXConstructorDecl *CD = Construct->getConstructor();
if (!CD->isTrivial() && !RD->hasAttr<WarnUnusedAttr>() &&
(VD->getInit()->isValueDependent() || !VD->evaluateValue()))
return false;
}
// Suppress the warning if we don't know how this is constructed, and
// it could possibly be non-trivial constructor.
if (Init->isTypeDependent()) {
for (const CXXConstructorDecl *Ctor : RD->ctors())
if (!Ctor->isTrivial())
return false;
}
// Suppress the warning if the constructor is unresolved because
// its arguments are dependent.
if (isa<CXXUnresolvedConstructExpr>(Init))
return false;
}
}
}
// TODO: __attribute__((unused)) templates?
}
return true;
}
static void GenerateFixForUnusedDecl(const NamedDecl *D, ASTContext &Ctx,
FixItHint &Hint) {
if (isa<LabelDecl>(D)) {
SourceLocation AfterColon = Lexer::findLocationAfterToken(
D->getEndLoc(), tok::colon, Ctx.getSourceManager(), Ctx.getLangOpts(),
/*SkipTrailingWhitespaceAndNewline=*/false);
if (AfterColon.isInvalid())
return;
Hint = FixItHint::CreateRemoval(
CharSourceRange::getCharRange(D->getBeginLoc(), AfterColon));
}
}
void Sema::DiagnoseUnusedNestedTypedefs(const RecordDecl *D) {
DiagnoseUnusedNestedTypedefs(
D, [this](SourceLocation Loc, PartialDiagnostic PD) { Diag(Loc, PD); });
}
void Sema::DiagnoseUnusedNestedTypedefs(const RecordDecl *D,
DiagReceiverTy DiagReceiver) {
if (D->isDependentType())
return;
for (auto *TmpD : D->decls()) {
if (const auto *T = dyn_cast<TypedefNameDecl>(TmpD))
DiagnoseUnusedDecl(T, DiagReceiver);
else if(const auto *R = dyn_cast<RecordDecl>(TmpD))
DiagnoseUnusedNestedTypedefs(R, DiagReceiver);
}
}
void Sema::DiagnoseUnusedDecl(const NamedDecl *D) {
DiagnoseUnusedDecl(
D, [this](SourceLocation Loc, PartialDiagnostic PD) { Diag(Loc, PD); });
}
void Sema::DiagnoseUnusedDecl(const NamedDecl *D, DiagReceiverTy DiagReceiver) {
if (!ShouldDiagnoseUnusedDecl(getLangOpts(), D))
return;
if (auto *TD = dyn_cast<TypedefNameDecl>(D)) {
// typedefs can be referenced later on, so the diagnostics are emitted
// at end-of-translation-unit.
UnusedLocalTypedefNameCandidates.insert(TD);
return;
}
FixItHint Hint;
GenerateFixForUnusedDecl(D, Context, Hint);
unsigned DiagID;
if (isa<VarDecl>(D) && cast<VarDecl>(D)->isExceptionVariable())
DiagID = diag::warn_unused_exception_param;
else if (isa<LabelDecl>(D))
DiagID = diag::warn_unused_label;
else
DiagID = diag::warn_unused_variable;
SourceLocation DiagLoc = D->getLocation();
DiagReceiver(DiagLoc, PDiag(DiagID) << D << Hint << SourceRange(DiagLoc));
}
void Sema::DiagnoseUnusedButSetDecl(const VarDecl *VD,
DiagReceiverTy DiagReceiver) {
// If it's not referenced, it can't be set. If it has the Cleanup attribute,
// it's not really unused.
if (!VD->isReferenced() || !VD->getDeclName() || VD->hasAttr<CleanupAttr>())
return;
// In C++, `_` variables behave as if they were maybe_unused
if (VD->hasAttr<UnusedAttr>() || VD->isPlaceholderVar(getLangOpts()))
return;
const auto *Ty = VD->getType().getTypePtr()->getBaseElementTypeUnsafe();
if (Ty->isReferenceType() || Ty->isDependentType())
return;
if (const TagDecl *Tag = Ty->getAsTagDecl()) {
if (Tag->hasAttr<UnusedAttr>())
return;
// In C++, don't warn for record types that don't have WarnUnusedAttr, to
// mimic gcc's behavior.
if (const auto *RD = dyn_cast<CXXRecordDecl>(Tag);
RD && !RD->hasAttr<WarnUnusedAttr>())
return;
}
// Don't warn about __block Objective-C pointer variables, as they might
// be assigned in the block but not used elsewhere for the purpose of lifetime
// extension.
if (VD->hasAttr<BlocksAttr>() && Ty->isObjCObjectPointerType())
return;
// Don't warn about Objective-C pointer variables with precise lifetime
// semantics; they can be used to ensure ARC releases the object at a known
// time, which may mean assignment but no other references.
if (VD->hasAttr<ObjCPreciseLifetimeAttr>() && Ty->isObjCObjectPointerType())
return;
auto iter = RefsMinusAssignments.find(VD);
if (iter == RefsMinusAssignments.end())
return;
assert(iter->getSecond() >= 0 &&
"Found a negative number of references to a VarDecl");
if (int RefCnt = iter->getSecond(); RefCnt > 0) {
// Assume the given VarDecl is "used" if its ref count stored in
// `RefMinusAssignments` is positive, with one exception.
//
// For a C++ variable whose decl (with initializer) entirely consist the
// condition expression of a if/while/for construct,
// Clang creates a DeclRefExpr for the condition expression rather than a
// BinaryOperator of AssignmentOp. Thus, the C++ variable's ref
// count stored in `RefMinusAssignment` equals 1 when the variable is never
// used in the body of the if/while/for construct.
bool UnusedCXXCondDecl = VD->isCXXCondDecl() && (RefCnt == 1);
if (!UnusedCXXCondDecl)
return;
}
unsigned DiagID = isa<ParmVarDecl>(VD) ? diag::warn_unused_but_set_parameter
: diag::warn_unused_but_set_variable;
DiagReceiver(VD->getLocation(), PDiag(DiagID) << VD);
}
static void CheckPoppedLabel(LabelDecl *L, Sema &S,
Sema::DiagReceiverTy DiagReceiver) {
// Verify that we have no forward references left. If so, there was a goto
// or address of a label taken, but no definition of it. Label fwd
// definitions are indicated with a null substmt which is also not a resolved
// MS inline assembly label name.
bool Diagnose = false;
if (L->isMSAsmLabel())
Diagnose = !L->isResolvedMSAsmLabel();
else
Diagnose = L->getStmt() == nullptr;
if (Diagnose)
DiagReceiver(L->getLocation(), S.PDiag(diag::err_undeclared_label_use)
<< L);
}
void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) {
S->applyNRVO();
if (S->decl_empty()) return;
assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) &&
"Scope shouldn't contain decls!");
/// We visit the decls in non-deterministic order, but we want diagnostics
/// emitted in deterministic order. Collect any diagnostic that may be emitted
/// and sort the diagnostics before emitting them, after we visited all decls.
struct LocAndDiag {
SourceLocation Loc;
std::optional<SourceLocation> PreviousDeclLoc;
PartialDiagnostic PD;
};
SmallVector<LocAndDiag, 16> DeclDiags;
auto addDiag = [&DeclDiags](SourceLocation Loc, PartialDiagnostic PD) {
DeclDiags.push_back(LocAndDiag{Loc, std::nullopt, std::move(PD)});
};
auto addDiagWithPrev = [&DeclDiags](SourceLocation Loc,
SourceLocation PreviousDeclLoc,
PartialDiagnostic PD) {
DeclDiags.push_back(LocAndDiag{Loc, PreviousDeclLoc, std::move(PD)});
};
for (auto *TmpD : S->decls()) {
assert(TmpD && "This decl didn't get pushed??");
assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?");
NamedDecl *D = cast<NamedDecl>(TmpD);
// Diagnose unused variables in this scope.
if (!S->hasUnrecoverableErrorOccurred()) {
DiagnoseUnusedDecl(D, addDiag);
if (const auto *RD = dyn_cast<RecordDecl>(D))
DiagnoseUnusedNestedTypedefs(RD, addDiag);
if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
DiagnoseUnusedButSetDecl(VD, addDiag);
RefsMinusAssignments.erase(VD);
}
}
if (!D->getDeclName()) continue;
// If this was a forward reference to a label, verify it was defined.
if (LabelDecl *LD = dyn_cast<LabelDecl>(D))
CheckPoppedLabel(LD, *this, addDiag);
// Partial translation units that are created in incremental processing must
// not clean up the IdResolver because PTUs should take into account the
// declarations that came from previous PTUs.
if (!PP.isIncrementalProcessingEnabled() || getLangOpts().ObjC ||
getLangOpts().CPlusPlus)
IdResolver.RemoveDecl(D);
// Warn on it if we are shadowing a declaration.
auto ShadowI = ShadowingDecls.find(D);
if (ShadowI != ShadowingDecls.end()) {
if (const auto *FD = dyn_cast<FieldDecl>(ShadowI->second)) {
addDiagWithPrev(D->getLocation(), FD->getLocation(),
PDiag(diag::warn_ctor_parm_shadows_field)
<< D << FD << FD->getParent());
}
ShadowingDecls.erase(ShadowI);
}
}
llvm::sort(DeclDiags,
[](const LocAndDiag &LHS, const LocAndDiag &RHS) -> bool {
// The particular order for diagnostics is not important, as long
// as the order is deterministic. Using the raw location is going
// to generally be in source order unless there are macro
// expansions involved.
return LHS.Loc.getRawEncoding() < RHS.Loc.getRawEncoding();
});
for (const LocAndDiag &D : DeclDiags) {
Diag(D.Loc, D.PD);
if (D.PreviousDeclLoc)
Diag(*D.PreviousDeclLoc, diag::note_previous_declaration);
}
}
Scope *Sema::getNonFieldDeclScope(Scope *S) {
while (((S->getFlags() & Scope::DeclScope) == 0) ||
(S->getEntity() && S->getEntity()->isTransparentContext()) ||
(S->isClassScope() && !getLangOpts().CPlusPlus))
S = S->getParent();
return S;
}
static StringRef getHeaderName(Builtin::Context &BuiltinInfo, unsigned ID,
ASTContext::GetBuiltinTypeError Error) {
switch (Error) {
case ASTContext::GE_None:
return "";
case ASTContext::GE_Missing_type:
return BuiltinInfo.getHeaderName(ID);
case ASTContext::GE_Missing_stdio:
return "stdio.h";
case ASTContext::GE_Missing_setjmp:
return "setjmp.h";
case ASTContext::GE_Missing_ucontext:
return "ucontext.h";
}
llvm_unreachable("unhandled error kind");
}
FunctionDecl *Sema::CreateBuiltin(IdentifierInfo *II, QualType Type,
unsigned ID, SourceLocation Loc) {
DeclContext *Parent = Context.getTranslationUnitDecl();
if (getLangOpts().CPlusPlus) {
LinkageSpecDecl *CLinkageDecl = LinkageSpecDecl::Create(
Context, Parent, Loc, Loc, LinkageSpecLanguageIDs::C, false);
CLinkageDecl->setImplicit();
Parent->addDecl(CLinkageDecl);
Parent = CLinkageDecl;
}
ConstexprSpecKind ConstexprKind = ConstexprSpecKind::Unspecified;
if (Context.BuiltinInfo.isImmediate(ID)) {
assert(getLangOpts().CPlusPlus20 &&
"consteval builtins should only be available in C++20 mode");
ConstexprKind = ConstexprSpecKind::Consteval;
}
FunctionDecl *New = FunctionDecl::Create(
Context, Parent, Loc, Loc, II, Type, /*TInfo=*/nullptr, SC_Extern,
getCurFPFeatures().isFPConstrained(), /*isInlineSpecified=*/false,
Type->isFunctionProtoType(), ConstexprKind);
New->setImplicit();
New->addAttr(BuiltinAttr::CreateImplicit(Context, ID));
// Create Decl objects for each parameter, adding them to the
// FunctionDecl.
if (const FunctionProtoType *FT = dyn_cast<FunctionProtoType>(Type)) {
SmallVector<ParmVarDecl *, 16> Params;
for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
ParmVarDecl *parm = ParmVarDecl::Create(
Context, New, SourceLocation(), SourceLocation(), nullptr,
FT->getParamType(i), /*TInfo=*/nullptr, SC_None, nullptr);
parm->setScopeInfo(0, i);
Params.push_back(parm);
}
New->setParams(Params);
}
AddKnownFunctionAttributes(New);
return New;
}
NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID,
Scope *S, bool ForRedeclaration,
SourceLocation Loc) {
LookupNecessaryTypesForBuiltin(S, ID);
ASTContext::GetBuiltinTypeError Error;
QualType R = Context.GetBuiltinType(ID, Error);
if (Error) {
if (!ForRedeclaration)
return nullptr;
// If we have a builtin without an associated type we should not emit a
// warning when we were not able to find a type for it.
if (Error == ASTContext::GE_Missing_type ||
Context.BuiltinInfo.allowTypeMismatch(ID))
return nullptr;
// If we could not find a type for setjmp it is because the jmp_buf type was
// not defined prior to the setjmp declaration.
if (Error == ASTContext::GE_Missing_setjmp) {
Diag(Loc, diag::warn_implicit_decl_no_jmp_buf)
<< Context.BuiltinInfo.getName(ID);
return nullptr;
}
// Generally, we emit a warning that the declaration requires the
// appropriate header.
Diag(Loc, diag::warn_implicit_decl_requires_sysheader)
<< getHeaderName(Context.BuiltinInfo, ID, Error)
<< Context.BuiltinInfo.getName(ID);
return nullptr;
}
if (!ForRedeclaration &&
(Context.BuiltinInfo.isPredefinedLibFunction(ID) ||
Context.BuiltinInfo.isHeaderDependentFunction(ID))) {
Diag(Loc, LangOpts.C99 ? diag::ext_implicit_lib_function_decl_c99
: diag::ext_implicit_lib_function_decl)
<< Context.BuiltinInfo.getName(ID) << R;
if (const char *Header = Context.BuiltinInfo.getHeaderName(ID))
Diag(Loc, diag::note_include_header_or_declare)
<< Header << Context.BuiltinInfo.getName(ID);
}
if (R.isNull())
return nullptr;
FunctionDecl *New = CreateBuiltin(II, R, ID, Loc);
RegisterLocallyScopedExternCDecl(New, S);
// TUScope is the translation-unit scope to insert this function into.
// FIXME: This is hideous. We need to teach PushOnScopeChains to
// relate Scopes to DeclContexts, and probably eliminate CurContext
// entirely, but we're not there yet.
DeclContext *SavedContext = CurContext;
CurContext = New->getDeclContext();
PushOnScopeChains(New, TUScope);
CurContext = SavedContext;
return New;
}
/// Typedef declarations don't have linkage, but they still denote the same
/// entity if their types are the same.
/// FIXME: This is notionally doing the same thing as ASTReaderDecl's
/// isSameEntity.
static void
filterNonConflictingPreviousTypedefDecls(Sema &S, const TypedefNameDecl *Decl,
LookupResult &Previous) {
// This is only interesting when modules are enabled.
if (!S.getLangOpts().Modules && !S.getLangOpts().ModulesLocalVisibility)
return;
// Empty sets are uninteresting.
if (Previous.empty())
return;
LookupResult::Filter Filter = Previous.makeFilter();
while (Filter.hasNext()) {
NamedDecl *Old = Filter.next();
// Non-hidden declarations are never ignored.
if (S.isVisible(Old))
continue;
// Declarations of the same entity are not ignored, even if they have
// different linkages.
if (auto *OldTD = dyn_cast<TypedefNameDecl>(Old)) {
if (S.Context.hasSameType(OldTD->getUnderlyingType(),
Decl->getUnderlyingType()))
continue;
// If both declarations give a tag declaration a typedef name for linkage
// purposes, then they declare the same entity.
if (OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true) &&
Decl->getAnonDeclWithTypedefName())
continue;
}
Filter.erase();
}
Filter.done();
}
bool Sema::isIncompatibleTypedef(const TypeDecl *Old, TypedefNameDecl *New) {
QualType OldType;
if (const TypedefNameDecl *OldTypedef = dyn_cast<TypedefNameDecl>(Old))
OldType = OldTypedef->getUnderlyingType();
else
OldType = Context.getTypeDeclType(Old);
QualType NewType = New->getUnderlyingType();
if (NewType->isVariablyModifiedType()) {
// Must not redefine a typedef with a variably-modified type.
int Kind = isa<TypeAliasDecl>(Old) ? 1 : 0;
Diag(New->getLocation(), diag::err_redefinition_variably_modified_typedef)
<< Kind << NewType;
if (Old->getLocation().isValid())
notePreviousDefinition(Old, New->getLocation());
New->setInvalidDecl();
return true;
}
if (OldType != NewType &&
!OldType->isDependentType() &&
!NewType->isDependentType() &&
!Context.hasSameType(OldType, NewType)) {
int Kind = isa<TypeAliasDecl>(Old) ? 1 : 0;
Diag(New->getLocation(), diag::err_redefinition_different_typedef)
<< Kind << NewType << OldType;
if (Old->getLocation().isValid())
notePreviousDefinition(Old, New->getLocation());
New->setInvalidDecl();
return true;
}
return false;
}
void Sema::MergeTypedefNameDecl(Scope *S, TypedefNameDecl *New,
LookupResult &OldDecls) {
// If the new decl is known invalid already, don't bother doing any
// merging checks.
if (New->isInvalidDecl()) return;
// Allow multiple definitions for ObjC built-in typedefs.
// FIXME: Verify the underlying types are equivalent!
if (getLangOpts().ObjC) {
const IdentifierInfo *TypeID = New->getIdentifier();
switch (TypeID->getLength()) {
default: break;
case 2:
{
if (!TypeID->isStr("id"))
break;
QualType T = New->getUnderlyingType();
if (!T->isPointerType())
break;
if (!T->isVoidPointerType()) {
QualType PT = T->castAs<PointerType>()->getPointeeType();
if (!PT->isStructureType())
break;
}
Context.setObjCIdRedefinitionType(T);
// Install the built-in type for 'id', ignoring the current definition.
New->setModedTypeSourceInfo(New->getTypeSourceInfo(),
Context.getObjCIdType());
return;
}
case 5:
if (!TypeID->isStr("Class"))
break;
Context.setObjCClassRedefinitionType(New->getUnderlyingType());
// Install the built-in type for 'Class', ignoring the current definition.
New->setModedTypeSourceInfo(New->getTypeSourceInfo(),
Context.getObjCClassType());
return;
case 3:
if (!TypeID->isStr("SEL"))
break;
Context.setObjCSelRedefinitionType(New->getUnderlyingType());
// Install the built-in type for 'SEL', ignoring the current definition.
New->setModedTypeSourceInfo(New->getTypeSourceInfo(),
Context.getObjCSelType());
return;
}
// Fall through - the typedef name was not a builtin type.
}
// Verify the old decl was also a type.
TypeDecl *Old = OldDecls.getAsSingle<TypeDecl>();
if (!Old) {
Diag(New->getLocation(), diag::err_redefinition_different_kind)
<< New->getDeclName();
NamedDecl *OldD = OldDecls.getRepresentativeDecl();
if (OldD->getLocation().isValid())
notePreviousDefinition(OldD, New->getLocation());
return New->setInvalidDecl();
}
// If the old declaration is invalid, just give up here.
if (Old->isInvalidDecl())
return New->setInvalidDecl();
if (auto *OldTD = dyn_cast<TypedefNameDecl>(Old)) {
auto *OldTag = OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true);
auto *NewTag = New->getAnonDeclWithTypedefName();
NamedDecl *Hidden = nullptr;
if (OldTag && NewTag &&
OldTag->getCanonicalDecl() != NewTag->getCanonicalDecl() &&
!hasVisibleDefinition(OldTag, &Hidden)) {
// There is a definition of this tag, but it is not visible. Use it
// instead of our tag.
if (OldTD->isModed())
New->setModedTypeSourceInfo(OldTD->getTypeSourceInfo(),
OldTD->getUnderlyingType());
else
New->setTypeSourceInfo(OldTD->getTypeSourceInfo());
// Make the old tag definition visible.
makeMergedDefinitionVisible(Hidden);
CleanupMergedEnum(S, NewTag);
}
}
// If the typedef types are not identical, reject them in all languages and
// with any extensions enabled.
if (isIncompatibleTypedef(Old, New))
return;
// The types match. Link up the redeclaration chain and merge attributes if
// the old declaration was a typedef.
if (TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Old)) {
New->setPreviousDecl(Typedef);
mergeDeclAttributes(New, Old);
}
if (getLangOpts().MicrosoftExt)
return;
if (getLangOpts().CPlusPlus) {
// C++ [dcl.typedef]p2:
// In a given non-class scope, a typedef specifier can be used to
// redefine the name of any type declared in that scope to refer
// to the type to which it already refers.
if (!isa<CXXRecordDecl>(CurContext))
return;
// C++0x [dcl.typedef]p4:
// In a given class scope, a typedef specifier can be used to redefine
// any class-name declared in that scope that is not also a typedef-name
// to refer to the type to which it already refers.
//
// This wording came in via DR424, which was a correction to the
// wording in DR56, which accidentally banned code like:
//
// struct S {
// typedef struct A { } A;
// };
//
// in the C++03 standard. We implement the C++0x semantics, which
// allow the above but disallow
//
// struct S {
// typedef int I;
// typedef int I;
// };
//
// since that was the intent of DR56.
if (!isa<TypedefNameDecl>(Old))
return;
Diag(New->getLocation(), diag::err_redefinition)
<< New->getDeclName();
notePreviousDefinition(Old, New->getLocation());
return New->setInvalidDecl();
}
// Modules always permit redefinition of typedefs, as does C11.
if (getLangOpts().Modules || getLangOpts().C11)
return;
// If we have a redefinition of a typedef in C, emit a warning. This warning
// is normally mapped to an error, but can be controlled with
// -Wtypedef-redefinition. If either the original or the redefinition is
// in a system header, don't emit this for compatibility with GCC.
if (getDiagnostics().getSuppressSystemWarnings() &&
// Some standard types are defined implicitly in Clang (e.g. OpenCL).
(Old->isImplicit() ||
Context.getSourceManager().isInSystemHeader(Old->getLocation()) ||
Context.getSourceManager().isInSystemHeader(New->getLocation())))
return;
Diag(New->getLocation(), diag::ext_redefinition_of_typedef)
<< New->getDeclName();
notePreviousDefinition(Old, New->getLocation());
}
void Sema::CleanupMergedEnum(Scope *S, Decl *New) {
// If this was an unscoped enumeration, yank all of its enumerators
// out of the scope.
if (auto *ED = dyn_cast<EnumDecl>(New); ED && !ED->isScoped()) {
Scope *EnumScope = getNonFieldDeclScope(S);
for (auto *ECD : ED->enumerators()) {
assert(EnumScope->isDeclScope(ECD));
EnumScope->RemoveDecl(ECD);
IdResolver.RemoveDecl(ECD);
}
}
}
/// DeclhasAttr - returns true if decl Declaration already has the target
/// attribute.
static bool DeclHasAttr(const Decl *D, const Attr *A) {
const OwnershipAttr *OA = dyn_cast<OwnershipAttr>(A);
const AnnotateAttr *Ann = dyn_cast<AnnotateAttr>(A);
for (const auto *i : D->attrs())
if (i->getKind() == A->getKind()) {
if (Ann) {
if (Ann->getAnnotation() == cast<AnnotateAttr>(i)->getAnnotation())
return true;
continue;
}
// FIXME: Don't hardcode this check
if (OA && isa<OwnershipAttr>(i))
return OA->getOwnKind() == cast<OwnershipAttr>(i)->getOwnKind();
return true;
}
return false;
}
static bool isAttributeTargetADefinition(Decl *D) {
if (VarDecl *VD = dyn_cast<VarDecl>(D))
return VD->isThisDeclarationADefinition();
if (TagDecl *TD = dyn_cast<TagDecl>(D))
return TD->isCompleteDefinition() || TD->isBeingDefined();
return true;
}
/// Merge alignment attributes from \p Old to \p New, taking into account the
/// special semantics of C11's _Alignas specifier and C++11's alignas attribute.
///
/// \return \c true if any attributes were added to \p New.
static bool mergeAlignedAttrs(Sema &S, NamedDecl *New, Decl *Old) {
// Look for alignas attributes on Old, and pick out whichever attribute
// specifies the strictest alignment requirement.
AlignedAttr *OldAlignasAttr = nullptr;
AlignedAttr *OldStrictestAlignAttr = nullptr;
unsigned OldAlign = 0;
for (auto *I : Old->specific_attrs<AlignedAttr>()) {
// FIXME: We have no way of representing inherited dependent alignments
// in a case like:
// template<int A, int B> struct alignas(A) X;
// template<int A, int B> struct alignas(B) X {};
// For now, we just ignore any alignas attributes which are not on the
// definition in such a case.
if (I->isAlignmentDependent())
return false;
if (I->isAlignas())
OldAlignasAttr = I;
unsigned Align = I->getAlignment(S.Context);
if (Align > OldAlign) {
OldAlign = Align;
OldStrictestAlignAttr = I;
}
}
// Look for alignas attributes on New.
AlignedAttr *NewAlignasAttr = nullptr;
unsigned NewAlign = 0;
for (auto *I : New->specific_attrs<AlignedAttr>()) {
if (I->isAlignmentDependent())
return false;
if (I->isAlignas())
NewAlignasAttr = I;
unsigned Align = I->getAlignment(S.Context);
if (Align > NewAlign)
NewAlign = Align;
}
if (OldAlignasAttr && NewAlignasAttr && OldAlign != NewAlign) {
// Both declarations have 'alignas' attributes. We require them to match.
// C++11 [dcl.align]p6 and C11 6.7.5/7 both come close to saying this, but
// fall short. (If two declarations both have alignas, they must both match
// every definition, and so must match each other if there is a definition.)
// If either declaration only contains 'alignas(0)' specifiers, then it
// specifies the natural alignment for the type.
if (OldAlign == 0 || NewAlign == 0) {
QualType Ty;
if (ValueDecl *VD = dyn_cast<ValueDecl>(New))
Ty = VD->getType();
else
Ty = S.Context.getCanonicalTagType(cast<TagDecl>(New));
if (OldAlign == 0)
OldAlign = S.Context.getTypeAlign(Ty);
if (NewAlign == 0)
NewAlign = S.Context.getTypeAlign(Ty);
}
if (OldAlign != NewAlign) {
S.Diag(NewAlignasAttr->getLocation(), diag::err_alignas_mismatch)
<< (unsigned)S.Context.toCharUnitsFromBits(OldAlign).getQuantity()
<< (unsigned)S.Context.toCharUnitsFromBits(NewAlign).getQuantity();
S.Diag(OldAlignasAttr->getLocation(), diag::note_previous_declaration);
}
}
if (OldAlignasAttr && !NewAlignasAttr && isAttributeTargetADefinition(New)) {
// C++11 [dcl.align]p6:
// if any declaration of an entity has an alignment-specifier,
// every defining declaration of that entity shall specify an
// equivalent alignment.
// C11 6.7.5/7:
// If the definition of an object does not have an alignment
// specifier, any other declaration of that object shall also
// have no alignment specifier.
S.Diag(New->getLocation(), diag::err_alignas_missing_on_definition)
<< OldAlignasAttr;
S.Diag(OldAlignasAttr->getLocation(), diag::note_alignas_on_declaration)
<< OldAlignasAttr;
}
bool AnyAdded = false;
// Ensure we have an attribute representing the strictest alignment.
if (OldAlign > NewAlign) {
AlignedAttr *Clone = OldStrictestAlignAttr->clone(S.Context);
Clone->setInherited(true);
New->addAttr(Clone);
AnyAdded = true;
}
// Ensure we have an alignas attribute if the old declaration had one.
if (OldAlignasAttr && !NewAlignasAttr &&
!(AnyAdded && OldStrictestAlignAttr->isAlignas())) {
AlignedAttr *Clone = OldAlignasAttr->clone(S.Context);
Clone->setInherited(true);
New->addAttr(Clone);
AnyAdded = true;
}
return AnyAdded;
}
#define WANT_DECL_MERGE_LOGIC
#include "clang/Sema/AttrParsedAttrImpl.inc"
#undef WANT_DECL_MERGE_LOGIC
static bool mergeDeclAttribute(Sema &S, NamedDecl *D,
const InheritableAttr *Attr,
AvailabilityMergeKind AMK) {
// Diagnose any mutual exclusions between the attribute that we want to add
// and attributes that already exist on the declaration.
if (!DiagnoseMutualExclusions(S, D, Attr))
return false;
// This function copies an attribute Attr from a previous declaration to the
// new declaration D if the new declaration doesn't itself have that attribute
// yet or if that attribute allows duplicates.
// If you're adding a new attribute that requires logic different from
// "use explicit attribute on decl if present, else use attribute from
// previous decl", for example if the attribute needs to be consistent
// between redeclarations, you need to call a custom merge function here.
InheritableAttr *NewAttr = nullptr;
if (const auto *AA = dyn_cast<AvailabilityAttr>(Attr))
NewAttr = S.mergeAvailabilityAttr(
D, *AA, AA->getPlatform(), AA->isImplicit(), AA->getIntroduced(),
AA->getDeprecated(), AA->getObsoleted(), AA->getUnavailable(),
AA->getMessage(), AA->getStrict(), AA->getReplacement(), AMK,
AA->getPriority(), AA->getEnvironment());
else if (const auto *VA = dyn_cast<VisibilityAttr>(Attr))
NewAttr = S.mergeVisibilityAttr(D, *VA, VA->getVisibility());
else if (const auto *VA = dyn_cast<TypeVisibilityAttr>(Attr))
NewAttr = S.mergeTypeVisibilityAttr(D, *VA, VA->getVisibility());
else if (const auto *ImportA = dyn_cast<DLLImportAttr>(Attr))
NewAttr = S.mergeDLLImportAttr(D, *ImportA);
else if (const auto *ExportA = dyn_cast<DLLExportAttr>(Attr))
NewAttr = S.mergeDLLExportAttr(D, *ExportA);
else if (const auto *EA = dyn_cast<ErrorAttr>(Attr))
NewAttr = S.mergeErrorAttr(D, *EA, EA->getUserDiagnostic());
else if (const auto *FA = dyn_cast<FormatAttr>(Attr))
NewAttr = S.mergeFormatAttr(D, *FA, FA->getType(), FA->getFormatIdx(),
FA->getFirstArg());
else if (const auto *FMA = dyn_cast<FormatMatchesAttr>(Attr))
NewAttr = S.mergeFormatMatchesAttr(
D, *FMA, FMA->getType(), FMA->getFormatIdx(), FMA->getFormatString());
else if (const auto *SA = dyn_cast<SectionAttr>(Attr))
NewAttr = S.mergeSectionAttr(D, *SA, SA->getName());
else if (const auto *CSA = dyn_cast<CodeSegAttr>(Attr))
NewAttr = S.mergeCodeSegAttr(D, *CSA, CSA->getName());
else if (const auto *IA = dyn_cast<MSInheritanceAttr>(Attr))
NewAttr = S.mergeMSInheritanceAttr(D, *IA, IA->getBestCase(),
IA->getInheritanceModel());
else if (const auto *AA = dyn_cast<AlwaysInlineAttr>(Attr))
NewAttr = S.mergeAlwaysInlineAttr(D, *AA,
&S.Context.Idents.get(AA->getSpelling()));
else if (S.getLangOpts().CUDA && isa<FunctionDecl>(D) &&
(isa<CUDAHostAttr>(Attr) || isa<CUDADeviceAttr>(Attr) ||
isa<CUDAGlobalAttr>(Attr))) {
// CUDA target attributes are part of function signature for
// overloading purposes and must not be merged.
return false;
} else if (const auto *MA = dyn_cast<MinSizeAttr>(Attr))
NewAttr = S.mergeMinSizeAttr(D, *MA);
else if (const auto *SNA = dyn_cast<SwiftNameAttr>(Attr))
NewAttr = S.Swift().mergeNameAttr(D, *SNA, SNA->getName());
else if (const auto *OA = dyn_cast<OptimizeNoneAttr>(Attr))
NewAttr = S.mergeOptimizeNoneAttr(D, *OA);
else if (const auto *InternalLinkageA = dyn_cast<InternalLinkageAttr>(Attr))
NewAttr = S.mergeInternalLinkageAttr(D, *InternalLinkageA);
else if (isa<AlignedAttr>(Attr))
// AlignedAttrs are handled separately, because we need to handle all
// such attributes on a declaration at the same time.
NewAttr = nullptr;
else if ((isa<DeprecatedAttr>(Attr) || isa<UnavailableAttr>(Attr)) &&
(AMK == AvailabilityMergeKind::Override ||
AMK == AvailabilityMergeKind::ProtocolImplementation ||
AMK == AvailabilityMergeKind::OptionalProtocolImplementation))
NewAttr = nullptr;
else if (const auto *UA = dyn_cast<UuidAttr>(Attr))
NewAttr = S.mergeUuidAttr(D, *UA, UA->getGuid(), UA->getGuidDecl());
else if (const auto *IMA = dyn_cast<WebAssemblyImportModuleAttr>(Attr))
NewAttr = S.Wasm().mergeImportModuleAttr(D, *IMA);
else if (const auto *INA = dyn_cast<WebAssemblyImportNameAttr>(Attr))
NewAttr = S.Wasm().mergeImportNameAttr(D, *INA);
else if (const auto *TCBA = dyn_cast<EnforceTCBAttr>(Attr))
NewAttr = S.mergeEnforceTCBAttr(D, *TCBA);
else if (const auto *TCBLA = dyn_cast<EnforceTCBLeafAttr>(Attr))
NewAttr = S.mergeEnforceTCBLeafAttr(D, *TCBLA);
else if (const auto *BTFA = dyn_cast<BTFDeclTagAttr>(Attr))
NewAttr = S.mergeBTFDeclTagAttr(D, *BTFA);
else if (const auto *NT = dyn_cast<HLSLNumThreadsAttr>(Attr))
NewAttr = S.HLSL().mergeNumThreadsAttr(D, *NT, NT->getX(), NT->getY(),
NT->getZ());
else if (const auto *WS = dyn_cast<HLSLWaveSizeAttr>(Attr))
NewAttr = S.HLSL().mergeWaveSizeAttr(D, *WS, WS->getMin(), WS->getMax(),
WS->getPreferred(),
WS->getSpelledArgsCount());
else if (const auto *CI = dyn_cast<HLSLVkConstantIdAttr>(Attr))
NewAttr = S.HLSL().mergeVkConstantIdAttr(D, *CI, CI->getId());
else if (const auto *SA = dyn_cast<HLSLShaderAttr>(Attr))
NewAttr = S.HLSL().mergeShaderAttr(D, *SA, SA->getType());
else if (isa<SuppressAttr>(Attr))
// Do nothing. Each redeclaration should be suppressed separately.
NewAttr = nullptr;
else if (const auto *RD = dyn_cast<OpenACCRoutineDeclAttr>(Attr))
NewAttr = S.OpenACC().mergeRoutineDeclAttr(*RD);
else if (Attr->shouldInheritEvenIfAlreadyPresent() || !DeclHasAttr(D, Attr))
NewAttr = cast<InheritableAttr>(Attr->clone(S.Context));
if (NewAttr) {
NewAttr->setInherited(true);
D->addAttr(NewAttr);
if (isa<MSInheritanceAttr>(NewAttr))
S.Consumer.AssignInheritanceModel(cast<CXXRecordDecl>(D));
return true;
}
return false;
}
static const NamedDecl *getDefinition(const Decl *D) {
if (const TagDecl *TD = dyn_cast<TagDecl>(D)) {
if (const auto *Def = TD->getDefinition(); Def && !Def->isBeingDefined())
return Def;
return nullptr;
}
if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
const VarDecl *Def = VD->getDefinition();
if (Def)
return Def;
return VD->getActingDefinition();
}
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
const FunctionDecl *Def = nullptr;
if (FD->isDefined(Def, true))
return Def;
}
return nullptr;
}
static bool hasAttribute(const Decl *D, attr::Kind Kind) {
for (const auto *Attribute : D->attrs())
if (Attribute->getKind() == Kind)
return true;
return false;
}
/// checkNewAttributesAfterDef - If we already have a definition, check that
/// there are no new attributes in this declaration.
static void checkNewAttributesAfterDef(Sema &S, Decl *New, const Decl *Old) {
if (!New->hasAttrs())
return;
const NamedDecl *Def = getDefinition(Old);
if (!Def || Def == New)
return;
AttrVec &NewAttributes = New->getAttrs();
for (unsigned I = 0, E = NewAttributes.size(); I != E;) {
Attr *NewAttribute = NewAttributes[I];
if (isa<AliasAttr>(NewAttribute) || isa<IFuncAttr>(NewAttribute)) {
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(New)) {
SkipBodyInfo SkipBody;
S.CheckForFunctionRedefinition(FD, cast<FunctionDecl>(Def), &SkipBody);
// If we're skipping this definition, drop the "alias" attribute.
if (SkipBody.ShouldSkip) {
NewAttributes.erase(NewAttributes.begin() + I);
--E;
continue;
}
} else {
VarDecl *VD = cast<VarDecl>(New);
unsigned Diag = cast<VarDecl>(Def)->isThisDeclarationADefinition() ==
VarDecl::TentativeDefinition
? diag::err_alias_after_tentative
: diag::err_redefinition;
S.Diag(VD->getLocation(), Diag) << VD->getDeclName();
if (Diag == diag::err_redefinition)
S.notePreviousDefinition(Def, VD->getLocation());
else
S.Diag(Def->getLocation(), diag::note_previous_definition);
VD->setInvalidDecl();
}
++I;
continue;
}
if (const VarDecl *VD = dyn_cast<VarDecl>(Def)) {
// Tentative definitions are only interesting for the alias check above.
if (VD->isThisDeclarationADefinition() != VarDecl::Definition) {
++I;
continue;
}
}
if (hasAttribute(Def, NewAttribute->getKind())) {
++I;
continue; // regular attr merging will take care of validating this.
}
if (isa<C11NoReturnAttr>(NewAttribute)) {
// C's _Noreturn is allowed to be added to a function after it is defined.
++I;
continue;
} else if (isa<UuidAttr>(NewAttribute)) {
// msvc will allow a subsequent definition to add an uuid to a class
++I;
continue;
} else if (isa<DeprecatedAttr, WarnUnusedResultAttr, UnusedAttr>(
NewAttribute) &&
NewAttribute->isStandardAttributeSyntax()) {
// C++14 [dcl.attr.deprecated]p3: A name or entity declared without the
// deprecated attribute can later be re-declared with the attribute and
// vice-versa.
// C++17 [dcl.attr.unused]p4: A name or entity declared without the
// maybe_unused attribute can later be redeclared with the attribute and
// vice versa.
// C++20 [dcl.attr.nodiscard]p2: A name or entity declared without the
// nodiscard attribute can later be redeclared with the attribute and
// vice-versa.
// C23 6.7.13.3p3, 6.7.13.4p3. and 6.7.13.5p5 give the same allowances.
++I;
continue;
} else if (const AlignedAttr *AA = dyn_cast<AlignedAttr>(NewAttribute)) {
if (AA->isAlignas()) {
// C++11 [dcl.align]p6:
// if any declaration of an entity has an alignment-specifier,
// every defining declaration of that entity shall specify an
// equivalent alignment.
// C11 6.7.5/7:
// If the definition of an object does not have an alignment
// specifier, any other declaration of that object shall also
// have no alignment specifier.
S.Diag(Def->getLocation(), diag::err_alignas_missing_on_definition)
<< AA;
S.Diag(NewAttribute->getLocation(), diag::note_alignas_on_declaration)
<< AA;
NewAttributes.erase(NewAttributes.begin() + I);
--E;
continue;
}
} else if (isa<LoaderUninitializedAttr>(NewAttribute)) {
// If there is a C definition followed by a redeclaration with this
// attribute then there are two different definitions. In C++, prefer the
// standard diagnostics.
if (!S.getLangOpts().CPlusPlus) {
S.Diag(NewAttribute->getLocation(),
diag::err_loader_uninitialized_redeclaration);
S.Diag(Def->getLocation(), diag::note_previous_definition);
NewAttributes.erase(NewAttributes.begin() + I);
--E;
continue;
}
} else if (isa<SelectAnyAttr>(NewAttribute) &&
cast<VarDecl>(New)->isInline() &&
!cast<VarDecl>(New)->isInlineSpecified()) {
// Don't warn about applying selectany to implicitly inline variables.
// Older compilers and language modes would require the use of selectany
// to make such variables inline, and it would have no effect if we
// honored it.
++I;
continue;
} else if (isa<OMPDeclareVariantAttr>(NewAttribute)) {
// We allow to add OMP[Begin]DeclareVariantAttr to be added to
// declarations after definitions.
++I;
continue;
} else if (isa<SYCLKernelEntryPointAttr>(NewAttribute)) {
// Elevate latent uses of the sycl_kernel_entry_point attribute to an
// error since the definition will have already been created without
// the semantic effects of the attribute having been applied.
S.Diag(NewAttribute->getLocation(),
diag::err_sycl_entry_point_after_definition)
<< NewAttribute;
S.Diag(Def->getLocation(), diag::note_previous_definition);
cast<SYCLKernelEntryPointAttr>(NewAttribute)->setInvalidAttr();
++I;
continue;
} else if (isa<SYCLExternalAttr>(NewAttribute)) {
// SYCLExternalAttr may be added after a definition.
++I;
continue;
}
S.Diag(NewAttribute->getLocation(),
diag::warn_attribute_precede_definition);
S.Diag(Def->getLocation(), diag::note_previous_definition);
NewAttributes.erase(NewAttributes.begin() + I);
--E;
}
}
static void diagnoseMissingConstinit(Sema &S, const VarDecl *InitDecl,
const ConstInitAttr *CIAttr,
bool AttrBeforeInit) {
SourceLocation InsertLoc = InitDecl->getInnerLocStart();
// Figure out a good way to write this specifier on the old declaration.
// FIXME: We should just use the spelling of CIAttr, but we don't preserve
// enough of the attribute list spelling information to extract that without
// heroics.
std::string SuitableSpelling;
if (S.getLangOpts().CPlusPlus20)
SuitableSpelling = std::string(
S.PP.getLastMacroWithSpelling(InsertLoc, {tok::kw_constinit}));
if (SuitableSpelling.empty() && S.getLangOpts().CPlusPlus11)
SuitableSpelling = std::string(S.PP.getLastMacroWithSpelling(
InsertLoc, {tok::l_square, tok::l_square,
S.PP.getIdentifierInfo("clang"), tok::coloncolon,
S.PP.getIdentifierInfo("require_constant_initialization"),
tok::r_square, tok::r_square}));
if (SuitableSpelling.empty())
SuitableSpelling = std::string(S.PP.getLastMacroWithSpelling(
InsertLoc, {tok::kw___attribute, tok::l_paren, tok::r_paren,
S.PP.getIdentifierInfo("require_constant_initialization"),
tok::r_paren, tok::r_paren}));
if (SuitableSpelling.empty() && S.getLangOpts().CPlusPlus20)
SuitableSpelling = "constinit";
if (SuitableSpelling.empty() && S.getLangOpts().CPlusPlus11)
SuitableSpelling = "[[clang::require_constant_initialization]]";
if (SuitableSpelling.empty())
SuitableSpelling = "__attribute__((require_constant_initialization))";
SuitableSpelling += " ";
if (AttrBeforeInit) {
// extern constinit int a;
// int a = 0; // error (missing 'constinit'), accepted as extension
assert(CIAttr->isConstinit() && "should not diagnose this for attribute");
S.Diag(InitDecl->getLocation(), diag::ext_constinit_missing)
<< InitDecl << FixItHint::CreateInsertion(InsertLoc, SuitableSpelling);
S.Diag(CIAttr->getLocation(), diag::note_constinit_specified_here);
} else {
// int a = 0;
// constinit extern int a; // error (missing 'constinit')
S.Diag(CIAttr->getLocation(),
CIAttr->isConstinit() ? diag::err_constinit_added_too_late
: diag::warn_require_const_init_added_too_late)
<< FixItHint::CreateRemoval(SourceRange(CIAttr->getLocation()));
S.Diag(InitDecl->getLocation(), diag::note_constinit_missing_here)
<< CIAttr->isConstinit()
<< FixItHint::CreateInsertion(InsertLoc, SuitableSpelling);
}
}
void Sema::mergeDeclAttributes(NamedDecl *New, Decl *Old,
AvailabilityMergeKind AMK) {
if (UsedAttr *OldAttr = Old->getMostRecentDecl()->getAttr<UsedAttr>()) {
UsedAttr *NewAttr = OldAttr->clone(Context);
NewAttr->setInherited(true);
New->addAttr(NewAttr);
}
if (RetainAttr *OldAttr = Old->getMostRecentDecl()->getAttr<RetainAttr>()) {
RetainAttr *NewAttr = OldAttr->clone(Context);
NewAttr->setInherited(true);
New->addAttr(NewAttr);
}
if (!Old->hasAttrs() && !New->hasAttrs())
return;
// [dcl.constinit]p1:
// If the [constinit] specifier is applied to any declaration of a
// variable, it shall be applied to the initializing declaration.
const auto *OldConstInit = Old->getAttr<ConstInitAttr>();
const auto *NewConstInit = New->getAttr<ConstInitAttr>();
if (bool(OldConstInit) != bool(NewConstInit)) {
const auto *OldVD = cast<VarDecl>(Old);
auto *NewVD = cast<VarDecl>(New);
// Find the initializing declaration. Note that we might not have linked
// the new declaration into the redeclaration chain yet.
const VarDecl *InitDecl = OldVD->getInitializingDeclaration();
if (!InitDecl &&
(NewVD->hasInit() || NewVD->isThisDeclarationADefinition()))
InitDecl = NewVD;
if (InitDecl == NewVD) {
// This is the initializing declaration. If it would inherit 'constinit',
// that's ill-formed. (Note that we do not apply this to the attribute
// form).
if (OldConstInit && OldConstInit->isConstinit())
diagnoseMissingConstinit(*this, NewVD, OldConstInit,
/*AttrBeforeInit=*/true);
} else if (NewConstInit) {
// This is the first time we've been told that this declaration should
// have a constant initializer. If we already saw the initializing
// declaration, this is too late.
if (InitDecl && InitDecl != NewVD) {
diagnoseMissingConstinit(*this, InitDecl, NewConstInit,
/*AttrBeforeInit=*/false);
NewVD->dropAttr<ConstInitAttr>();
}
}
}
// Attributes declared post-definition are currently ignored.
checkNewAttributesAfterDef(*this, New, Old);
if (AsmLabelAttr *NewA = New->getAttr<AsmLabelAttr>()) {
if (AsmLabelAttr *OldA = Old->getAttr<AsmLabelAttr>()) {
if (!OldA->isEquivalent(NewA)) {
// This redeclaration changes __asm__ label.
Diag(New->getLocation(), diag::err_different_asm_label);
Diag(OldA->getLocation(), diag::note_previous_declaration);
}
} else if (Old->isUsed()) {
// This redeclaration adds an __asm__ label to a declaration that has
// already been ODR-used.
Diag(New->getLocation(), diag::err_late_asm_label_name)
<< isa<FunctionDecl>(Old) << New->getAttr<AsmLabelAttr>()->getRange();
}
}
// Re-declaration cannot add abi_tag's.
if (const auto *NewAbiTagAttr = New->getAttr<AbiTagAttr>()) {
if (const auto *OldAbiTagAttr = Old->getAttr<AbiTagAttr>()) {
for (const auto &NewTag : NewAbiTagAttr->tags()) {
if (!llvm::is_contained(OldAbiTagAttr->tags(), NewTag)) {
Diag(NewAbiTagAttr->getLocation(),
diag::err_new_abi_tag_on_redeclaration)
<< NewTag;
Diag(OldAbiTagAttr->getLocation(), diag::note_previous_declaration);
}
}
} else {
Diag(NewAbiTagAttr->getLocation(), diag::err_abi_tag_on_redeclaration);
Diag(Old->getLocation(), diag::note_previous_declaration);
}
}
// This redeclaration adds a section attribute.
if (New->hasAttr<SectionAttr>() && !Old->hasAttr<SectionAttr>()) {
if (auto *VD = dyn_cast<VarDecl>(New)) {
if (VD->isThisDeclarationADefinition() == VarDecl::DeclarationOnly) {
Diag(New->getLocation(), diag::warn_attribute_section_on_redeclaration);
Diag(Old->getLocation(), diag::note_previous_declaration);
}
}
}
// Redeclaration adds code-seg attribute.
const auto *NewCSA = New->getAttr<CodeSegAttr>();
if (NewCSA && !Old->hasAttr<CodeSegAttr>() &&
!NewCSA->isImplicit() && isa<CXXMethodDecl>(New)) {
Diag(New->getLocation(), diag::warn_mismatched_section)
<< 0 /*codeseg*/;
Diag(Old->getLocation(), diag::note_previous_declaration);
}
if (!Old->hasAttrs())
return;
bool foundAny = New->hasAttrs();
// Ensure that any moving of objects within the allocated map is done before
// we process them.
if (!foundAny) New->setAttrs(AttrVec());
for (auto *I : Old->specific_attrs<InheritableAttr>()) {
// Ignore deprecated/unavailable/availability attributes if requested.
AvailabilityMergeKind LocalAMK = AvailabilityMergeKind::None;
if (isa<DeprecatedAttr>(I) ||
isa<UnavailableAttr>(I) ||
isa<AvailabilityAttr>(I)) {
switch (AMK) {
case AvailabilityMergeKind::None:
continue;
case AvailabilityMergeKind::Redeclaration:
case AvailabilityMergeKind::Override:
case AvailabilityMergeKind::ProtocolImplementation:
case AvailabilityMergeKind::OptionalProtocolImplementation:
LocalAMK = AMK;
break;
}
}
// Already handled.
if (isa<UsedAttr>(I) || isa<RetainAttr>(I))
continue;
if (isa<InferredNoReturnAttr>(I)) {
if (auto *FD = dyn_cast<FunctionDecl>(New);
FD &&
FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
continue; // Don't propagate inferred noreturn attributes to explicit
}
if (mergeDeclAttribute(*this, New, I, LocalAMK))
foundAny = true;
}
if (mergeAlignedAttrs(*this, New, Old))
foundAny = true;
if (!foundAny) New->dropAttrs();
}
// Returns the number of added attributes.
template <class T>
static unsigned propagateAttribute(ParmVarDecl *To, const ParmVarDecl *From,
Sema &S) {
unsigned found = 0;
for (const auto *I : From->specific_attrs<T>()) {
if (!DeclHasAttr(To, I)) {
T *newAttr = cast<T>(I->clone(S.Context));
newAttr->setInherited(true);
To->addAttr(newAttr);
++found;
}
}
return found;
}
template <class F>
static void propagateAttributes(ParmVarDecl *To, const ParmVarDecl *From,
F &&propagator) {
if (!From->hasAttrs()) {
return;
}
bool foundAny = To->hasAttrs();
// Ensure that any moving of objects within the allocated map is
// done before we process them.
if (!foundAny)
To->setAttrs(AttrVec());
foundAny |= std::forward<F>(propagator)(To, From) != 0;
if (!foundAny)
To->dropAttrs();
}
/// mergeParamDeclAttributes - Copy attributes from the old parameter
/// to the new one.
static void mergeParamDeclAttributes(ParmVarDecl *newDecl,
const ParmVarDecl *oldDecl,
Sema &S) {
// C++11 [dcl.attr.depend]p2:
// The first declaration of a function shall specify the
// carries_dependency attribute for its declarator-id if any declaration
// of the function specifies the carries_dependency attribute.
const CarriesDependencyAttr *CDA = newDecl->getAttr<CarriesDependencyAttr>();
if (CDA && !oldDecl->hasAttr<CarriesDependencyAttr>()) {
S.Diag(CDA->getLocation(),
diag::err_carries_dependency_missing_on_first_decl) << 1/*Param*/;
// Find the first declaration of the parameter.
// FIXME: Should we build redeclaration chains for function parameters?
const FunctionDecl *FirstFD =
cast<FunctionDecl>(oldDecl->getDeclContext())->getFirstDecl();
const ParmVarDecl *FirstVD =
FirstFD->getParamDecl(oldDecl->getFunctionScopeIndex());
S.Diag(FirstVD->getLocation(),
diag::note_carries_dependency_missing_first_decl) << 1/*Param*/;
}
propagateAttributes(
newDecl, oldDecl, [&S](ParmVarDecl *To, const ParmVarDecl *From) {
unsigned found = 0;
found += propagateAttribute<InheritableParamAttr>(To, From, S);
// Propagate the lifetimebound attribute from parameters to the
// most recent declaration. Note that this doesn't include the implicit
// 'this' parameter, as the attribute is applied to the function type in
// that case.
found += propagateAttribute<LifetimeBoundAttr>(To, From, S);
return found;
});
}
static bool EquivalentArrayTypes(QualType Old, QualType New,
const ASTContext &Ctx) {
auto NoSizeInfo = [&Ctx](QualType Ty) {
if (Ty->isIncompleteArrayType() || Ty->isPointerType())
return true;
if (const auto *VAT = Ctx.getAsVariableArrayType(Ty))
return VAT->getSizeModifier() == ArraySizeModifier::Star;
return false;
};
// `type[]` is equivalent to `type *` and `type[*]`.
if (NoSizeInfo(Old) && NoSizeInfo(New))
return true;
// Don't try to compare VLA sizes, unless one of them has the star modifier.
if (Old->isVariableArrayType() && New->isVariableArrayType()) {
const auto *OldVAT = Ctx.getAsVariableArrayType(Old);
const auto *NewVAT = Ctx.getAsVariableArrayType(New);
if ((OldVAT->getSizeModifier() == ArraySizeModifier::Star) ^
(NewVAT->getSizeModifier() == ArraySizeModifier::Star))
return false;
return true;
}
// Only compare size, ignore Size modifiers and CVR.
if (Old->isConstantArrayType() && New->isConstantArrayType()) {
return Ctx.getAsConstantArrayType(Old)->getSize() ==
Ctx.getAsConstantArrayType(New)->getSize();
}
// Don't try to compare dependent sized array
if (Old->isDependentSizedArrayType() && New->isDependentSizedArrayType()) {
return true;
}
return Old == New;
}
static void mergeParamDeclTypes(ParmVarDecl *NewParam,
const ParmVarDecl *OldParam,
Sema &S) {
if (auto Oldnullability = OldParam->getType()->getNullability()) {
if (auto Newnullability = NewParam->getType()->getNullability()) {
if (*Oldnullability != *Newnullability) {
S.Diag(NewParam->getLocation(), diag::warn_mismatched_nullability_attr)
<< DiagNullabilityKind(
*Newnullability,
((NewParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
!= 0))
<< DiagNullabilityKind(
*Oldnullability,
((OldParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
!= 0));
S.Diag(OldParam->getLocation(), diag::note_previous_declaration);
}
} else {
QualType NewT = NewParam->getType();
NewT = S.Context.getAttributedType(*Oldnullability, NewT, NewT);
NewParam->setType(NewT);
}
}
const auto *OldParamDT = dyn_cast<DecayedType>(OldParam->getType());
const auto *NewParamDT = dyn_cast<DecayedType>(NewParam->getType());
if (OldParamDT && NewParamDT &&
OldParamDT->getPointeeType() == NewParamDT->getPointeeType()) {
QualType OldParamOT = OldParamDT->getOriginalType();
QualType NewParamOT = NewParamDT->getOriginalType();
if (!EquivalentArrayTypes(OldParamOT, NewParamOT, S.getASTContext())) {
S.Diag(NewParam->getLocation(), diag::warn_inconsistent_array_form)
<< NewParam << NewParamOT;
S.Diag(OldParam->getLocation(), diag::note_previous_declaration_as)
<< OldParamOT;
}
}
}
namespace {
/// Used in MergeFunctionDecl to keep track of function parameters in
/// C.
struct GNUCompatibleParamWarning {
ParmVarDecl *OldParm;
ParmVarDecl *NewParm;
QualType PromotedType;
};
} // end anonymous namespace
// Determine whether the previous declaration was a definition, implicit
// declaration, or a declaration.
template <typename T>
static std::pair<diag::kind, SourceLocation>
getNoteDiagForInvalidRedeclaration(const T *Old, const T *New) {
diag::kind PrevDiag;
SourceLocation OldLocation = Old->getLocation();
if (Old->isThisDeclarationADefinition())
PrevDiag = diag::note_previous_definition;
else if (Old->isImplicit()) {
PrevDiag = diag::note_previous_implicit_declaration;
if (const auto *FD = dyn_cast<FunctionDecl>(Old)) {
if (FD->getBuiltinID())
PrevDiag = diag::note_previous_builtin_declaration;
}
if (OldLocation.isInvalid())
OldLocation = New->getLocation();
} else
PrevDiag = diag::note_previous_declaration;
return std::make_pair(PrevDiag, OldLocation);
}
/// canRedefineFunction - checks if a function can be redefined. Currently,
/// only extern inline functions can be redefined, and even then only in
/// GNU89 mode.
static bool canRedefineFunction(const FunctionDecl *FD,
const LangOptions& LangOpts) {
return ((FD->hasAttr<GNUInlineAttr>() || LangOpts.GNUInline) &&
!LangOpts.CPlusPlus &&
FD->isInlineSpecified() &&
FD->getStorageClass() == SC_Extern);
}
const AttributedType *Sema::getCallingConvAttributedType(QualType T) const {
const AttributedType *AT = T->getAs<AttributedType>();
while (AT && !AT->isCallingConv())
AT = AT->getModifiedType()->getAs<AttributedType>();
return AT;
}
template <typename T>
static bool haveIncompatibleLanguageLinkages(const T *Old, const T *New) {
const DeclContext *DC = Old->getDeclContext();
if (DC->isRecord())
return false;
LanguageLinkage OldLinkage = Old->getLanguageLinkage();
if (OldLinkage == CXXLanguageLinkage && New->isInExternCContext())
return true;
if (OldLinkage == CLanguageLinkage && New->isInExternCXXContext())
return true;
return false;
}
template<typename T> static bool isExternC(T *D) { return D->isExternC(); }
static bool isExternC(VarTemplateDecl *) { return false; }
static bool isExternC(FunctionTemplateDecl *) { return false; }
/// Check whether a redeclaration of an entity introduced by a
/// using-declaration is valid, given that we know it's not an overload
/// (nor a hidden tag declaration).
template<typename ExpectedDecl>
static bool checkUsingShadowRedecl(Sema &S, UsingShadowDecl *OldS,
ExpectedDecl *New) {
// C++11 [basic.scope.declarative]p4:
// Given a set of declarations in a single declarative region, each of
// which specifies the same unqualified name,
// -- they shall all refer to the same entity, or all refer to functions
// and function templates; or
// -- exactly one declaration shall declare a class name or enumeration
// name that is not a typedef name and the other declarations shall all
// refer to the same variable or enumerator, or all refer to functions
// and function templates; in this case the class name or enumeration
// name is hidden (3.3.10).
// C++11 [namespace.udecl]p14:
// If a function declaration in namespace scope or block scope has the
// same name and the same parameter-type-list as a function introduced
// by a using-declaration, and the declarations do not declare the same
// function, the program is ill-formed.
auto *Old = dyn_cast<ExpectedDecl>(OldS->getTargetDecl());
if (Old &&
!Old->getDeclContext()->getRedeclContext()->Equals(
New->getDeclContext()->getRedeclContext()) &&
!(isExternC(Old) && isExternC(New)))
Old = nullptr;
if (!Old) {
S.Diag(New->getLocation(), diag::err_using_decl_conflict_reverse);
S.Diag(OldS->getTargetDecl()->getLocation(), diag::note_using_decl_target);
S.Diag(OldS->getIntroducer()->getLocation(), diag::note_using_decl) << 0;
return true;
}
return false;
}
static bool hasIdenticalPassObjectSizeAttrs(const FunctionDecl *A,
const FunctionDecl *B) {
assert(A->getNumParams() == B->getNumParams());
auto AttrEq = [](const ParmVarDecl *A, const ParmVarDecl *B) {
const auto *AttrA = A->getAttr<PassObjectSizeAttr>();
const auto *AttrB = B->getAttr<PassObjectSizeAttr>();
if (AttrA == AttrB)
return true;
return AttrA && AttrB && AttrA->getType() == AttrB->getType() &&
AttrA->isDynamic() == AttrB->isDynamic();
};
return std::equal(A->param_begin(), A->param_end(), B->param_begin(), AttrEq);
}
/// If necessary, adjust the semantic declaration context for a qualified
/// declaration to name the correct inline namespace within the qualifier.
static void adjustDeclContextForDeclaratorDecl(DeclaratorDecl *NewD,
DeclaratorDecl *OldD) {
// The only case where we need to update the DeclContext is when
// redeclaration lookup for a qualified name finds a declaration
// in an inline namespace within the context named by the qualifier:
//
// inline namespace N { int f(); }
// int ::f(); // Sema DC needs adjusting from :: to N::.
//
// For unqualified declarations, the semantic context *can* change
// along the redeclaration chain (for local extern declarations,
// extern "C" declarations, and friend declarations in particular).
if (!NewD->getQualifier())
return;
// NewD is probably already in the right context.
auto *NamedDC = NewD->getDeclContext()->getRedeclContext();
auto *SemaDC = OldD->getDeclContext()->getRedeclContext();
if (NamedDC->Equals(SemaDC))
return;
assert((NamedDC->InEnclosingNamespaceSetOf(SemaDC) ||
NewD->isInvalidDecl() || OldD->isInvalidDecl()) &&
"unexpected context for redeclaration");
auto *LexDC = NewD->getLexicalDeclContext();
auto FixSemaDC = [=](NamedDecl *D) {
if (!D)
return;
D->setDeclContext(SemaDC);
D->setLexicalDeclContext(LexDC);
};
FixSemaDC(NewD);
if (auto *FD = dyn_cast<FunctionDecl>(NewD))
FixSemaDC(FD->getDescribedFunctionTemplate());
else if (auto *VD = dyn_cast<VarDecl>(NewD))
FixSemaDC(VD->getDescribedVarTemplate());
}
bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
bool MergeTypeWithOld, bool NewDeclIsDefn) {
// Verify the old decl was also a function.
FunctionDecl *Old = OldD->getAsFunction();
if (!Old) {
if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(OldD)) {
// We don't need to check the using friend pattern from other module unit
// since we should have diagnosed such cases in its unit already.
if (New->getFriendObjectKind() && !OldD->isInAnotherModuleUnit()) {
Diag(New->getLocation(), diag::err_using_decl_friend);
Diag(Shadow->getTargetDecl()->getLocation(),
diag::note_using_decl_target);
Diag(Shadow->getIntroducer()->getLocation(), diag::note_using_decl)
<< 0;
return true;
}
// Check whether the two declarations might declare the same function or
// function template.
if (FunctionTemplateDecl *NewTemplate =
New->getDescribedFunctionTemplate()) {
if (checkUsingShadowRedecl<FunctionTemplateDecl>(*this, Shadow,
NewTemplate))
return true;
OldD = Old = cast<FunctionTemplateDecl>(Shadow->getTargetDecl())
->getAsFunction();
} else {
if (checkUsingShadowRedecl<FunctionDecl>(*this, Shadow, New))
return true;
OldD = Old = cast<FunctionDecl>(Shadow->getTargetDecl());
}
} else {
Diag(New->getLocation(), diag::err_redefinition_different_kind)
<< New->getDeclName();
notePreviousDefinition(OldD, New->getLocation());
return true;
}
}
// If the old declaration was found in an inline namespace and the new
// declaration was qualified, update the DeclContext to match.
adjustDeclContextForDeclaratorDecl(New, Old);
// If the old declaration is invalid, just give up here.
if (Old->isInvalidDecl())
return true;
// Disallow redeclaration of some builtins.
if (!getASTContext().canBuiltinBeRedeclared(Old)) {
Diag(New->getLocation(), diag::err_builtin_redeclare) << Old->getDeclName();
Diag(Old->getLocation(), diag::note_previous_builtin_declaration)
<< Old << Old->getType();
return true;
}
diag::kind PrevDiag;
SourceLocation OldLocation;
std::tie(PrevDiag, OldLocation) =
getNoteDiagForInvalidRedeclaration(Old, New);
// Don't complain about this if we're in GNU89 mode and the old function
// is an extern inline function.
// Don't complain about specializations. They are not supposed to have
// storage classes.
if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) &&
New->getStorageClass() == SC_Static &&
Old->hasExternalFormalLinkage() &&
!New->getTemplateSpecializationInfo() &&
!canRedefineFunction(Old, getLangOpts())) {
if (getLangOpts().MicrosoftExt) {
Diag(New->getLocation(), diag::ext_static_non_static) << New;
Diag(OldLocation, PrevDiag) << Old << Old->getType();
} else {
Diag(New->getLocation(), diag::err_static_non_static) << New;
Diag(OldLocation, PrevDiag) << Old << Old->getType();
return true;
}
}
if (const auto *ILA = New->getAttr<InternalLinkageAttr>())
if (!Old->hasAttr<InternalLinkageAttr>()) {
Diag(New->getLocation(), diag::err_attribute_missing_on_first_decl)
<< ILA;
Diag(Old->getLocation(), diag::note_previous_declaration);
New->dropAttr<InternalLinkageAttr>();
}
if (auto *EA = New->getAttr<ErrorAttr>()) {
if (!Old->hasAttr<ErrorAttr>()) {
Diag(EA->getLocation(), diag::err_attribute_missing_on_first_decl) << EA;
Diag(Old->getLocation(), diag::note_previous_declaration);
New->dropAttr<ErrorAttr>();
}
}
if (CheckRedeclarationInModule(New, Old))
return true;
if (!getLangOpts().CPlusPlus) {
bool OldOvl = Old->hasAttr<OverloadableAttr>();
if (OldOvl != New->hasAttr<OverloadableAttr>() && !Old->isImplicit()) {
Diag(New->getLocation(), diag::err_attribute_overloadable_mismatch)
<< New << OldOvl;
// Try our best to find a decl that actually has the overloadable
// attribute for the note. In most cases (e.g. programs with only one
// broken declaration/definition), this won't matter.
//
// FIXME: We could do this if we juggled some extra state in
// OverloadableAttr, rather than just removing it.
const Decl *DiagOld = Old;
if (OldOvl) {
auto OldIter = llvm::find_if(Old->redecls(), [](const Decl *D) {
const auto *A = D->getAttr<OverloadableAttr>();
return A && !A->isImplicit();
});
// If we've implicitly added *all* of the overloadable attrs to this
// chain, emitting a "previous redecl" note is pointless.
DiagOld = OldIter == Old->redecls_end() ? nullptr : *OldIter;
}
if (DiagOld)
Diag(DiagOld->getLocation(),
diag::note_attribute_overloadable_prev_overload)
<< OldOvl;
if (OldOvl)
New->addAttr(OverloadableAttr::CreateImplicit(Context));
else
New->dropAttr<OverloadableAttr>();
}
}
// It is not permitted to redeclare an SME function with different SME
// attributes.
if (IsInvalidSMECallConversion(Old->getType(), New->getType())) {
Diag(New->getLocation(), diag::err_sme_attr_mismatch)
<< New->getType() << Old->getType();
Diag(OldLocation, diag::note_previous_declaration);
return true;
}
// If a function is first declared with a calling convention, but is later
// declared or defined without one, all following decls assume the calling
// convention of the first.
//
// It's OK if a function is first declared without a calling convention,
// but is later declared or defined with the default calling convention.
//
// To test if either decl has an explicit calling convention, we look for
// AttributedType sugar nodes on the type as written. If they are missing or
// were canonicalized away, we assume the calling convention was implicit.
//
// Note also that we DO NOT return at this point, because we still have
// other tests to run.
QualType OldQType = Context.getCanonicalType(Old->getType());
QualType NewQType = Context.getCanonicalType(New->getType());
const FunctionType *OldType = cast<FunctionType>(OldQType);
const FunctionType *NewType = cast<FunctionType>(NewQType);
FunctionType::ExtInfo OldTypeInfo = OldType->getExtInfo();
FunctionType::ExtInfo NewTypeInfo = NewType->getExtInfo();
bool RequiresAdjustment = false;
if (OldTypeInfo.getCC() != NewTypeInfo.getCC()) {
FunctionDecl *First = Old->getFirstDecl();
const FunctionType *FT =
First->getType().getCanonicalType()->castAs<FunctionType>();
FunctionType::ExtInfo FI = FT->getExtInfo();
bool NewCCExplicit = getCallingConvAttributedType(New->getType());
if (!NewCCExplicit) {
// Inherit the CC from the previous declaration if it was specified
// there but not here.
NewTypeInfo = NewTypeInfo.withCallingConv(OldTypeInfo.getCC());
RequiresAdjustment = true;
} else if (Old->getBuiltinID()) {
// Builtin attribute isn't propagated to the new one yet at this point,
// so we check if the old one is a builtin.
// Calling Conventions on a Builtin aren't really useful and setting a
// default calling convention and cdecl'ing some builtin redeclarations is
// common, so warn and ignore the calling convention on the redeclaration.
Diag(New->getLocation(), diag::warn_cconv_unsupported)
<< FunctionType::getNameForCallConv(NewTypeInfo.getCC())
<< (int)CallingConventionIgnoredReason::BuiltinFunction;
NewTypeInfo = NewTypeInfo.withCallingConv(OldTypeInfo.getCC());
RequiresAdjustment = true;
} else {
// Calling conventions aren't compatible, so complain.
bool FirstCCExplicit = getCallingConvAttributedType(First->getType());
Diag(New->getLocation(), diag::err_cconv_change)
<< FunctionType::getNameForCallConv(NewTypeInfo.getCC())
<< !FirstCCExplicit
<< (!FirstCCExplicit ? "" :
FunctionType::getNameForCallConv(FI.getCC()));
// Put the note on the first decl, since it is the one that matters.
Diag(First->getLocation(), diag::note_previous_declaration);
return true;
}
}
// FIXME: diagnose the other way around?
if (OldTypeInfo.getNoReturn() && !NewTypeInfo.getNoReturn()) {
NewTypeInfo = NewTypeInfo.withNoReturn(true);
RequiresAdjustment = true;
}
// Merge regparm attribute.
if (OldTypeInfo.getHasRegParm() != NewTypeInfo.getHasRegParm() ||
OldTypeInfo.getRegParm() != NewTypeInfo.getRegParm()) {
if (NewTypeInfo.getHasRegParm()) {
Diag(New->getLocation(), diag::err_regparm_mismatch)
<< NewType->getRegParmType()
<< OldType->getRegParmType();
Diag(OldLocation, diag::note_previous_declaration);
return true;
}
NewTypeInfo = NewTypeInfo.withRegParm(OldTypeInfo.getRegParm());
RequiresAdjustment = true;
}
// Merge ns_returns_retained attribute.
if (OldTypeInfo.getProducesResult() != NewTypeInfo.getProducesResult()) {
if (NewTypeInfo.getProducesResult()) {
Diag(New->getLocation(), diag::err_function_attribute_mismatch)
<< "'ns_returns_retained'";
Diag(OldLocation, diag::note_previous_declaration);
return true;
}
NewTypeInfo = NewTypeInfo.withProducesResult(true);
RequiresAdjustment = true;
}
if (OldTypeInfo.getNoCallerSavedRegs() !=
NewTypeInfo.getNoCallerSavedRegs()) {
if (NewTypeInfo.getNoCallerSavedRegs()) {
AnyX86NoCallerSavedRegistersAttr *Attr =
New->getAttr<AnyX86NoCallerSavedRegistersAttr>();
Diag(New->getLocation(), diag::err_function_attribute_mismatch) << Attr;
Diag(OldLocation, diag::note_previous_declaration);
return true;
}
NewTypeInfo = NewTypeInfo.withNoCallerSavedRegs(true);
RequiresAdjustment = true;
}
if (RequiresAdjustment) {
const FunctionType *AdjustedType = New->getType()->getAs<FunctionType>();
AdjustedType = Context.adjustFunctionType(AdjustedType, NewTypeInfo);
New->setType(QualType(AdjustedType, 0));
NewQType = Context.getCanonicalType(New->getType());
}
// If this redeclaration makes the function inline, we may need to add it to
// UndefinedButUsed.
if (!Old->isInlined() && New->isInlined() && !New->hasAttr<GNUInlineAttr>() &&
!getLangOpts().GNUInline && Old->isUsed(false) && !Old->isDefined() &&
!New->isThisDeclarationADefinition() && !Old->isInAnotherModuleUnit())
UndefinedButUsed.insert(std::make_pair(Old->getCanonicalDecl(),
SourceLocation()));
// If this redeclaration makes it newly gnu_inline, we don't want to warn
// about it.
if (New->hasAttr<GNUInlineAttr>() &&
Old->isInlined() && !Old->hasAttr<GNUInlineAttr>()) {
UndefinedButUsed.erase(Old->getCanonicalDecl());
}
// If pass_object_size params don't match up perfectly, this isn't a valid
// redeclaration.
if (Old->getNumParams() > 0 && Old->getNumParams() == New->getNumParams() &&
!hasIdenticalPassObjectSizeAttrs(Old, New)) {
Diag(New->getLocation(), diag::err_different_pass_object_size_params)
<< New->getDeclName();
Diag(OldLocation, PrevDiag) << Old << Old->getType();
return true;
}
QualType OldQTypeForComparison = OldQType;
if (Context.hasAnyFunctionEffects()) {
const auto OldFX = Old->getFunctionEffects();
const auto NewFX = New->getFunctionEffects();
if (OldFX != NewFX) {
const auto Diffs = FunctionEffectDiffVector(OldFX, NewFX);
for (const auto &Diff : Diffs) {
if (Diff.shouldDiagnoseRedeclaration(*Old, OldFX, *New, NewFX)) {
Diag(New->getLocation(),
diag::warn_mismatched_func_effect_redeclaration)
<< Diff.effectName();
Diag(Old->getLocation(), diag::note_previous_declaration);
}
}
// Following a warning, we could skip merging effects from the previous
// declaration, but that would trigger an additional "conflicting types"
// error.
if (const auto *NewFPT = NewQType->getAs<FunctionProtoType>()) {
FunctionEffectSet::Conflicts MergeErrs;
FunctionEffectSet MergedFX =
FunctionEffectSet::getUnion(OldFX, NewFX, MergeErrs);
if (!MergeErrs.empty())
diagnoseFunctionEffectMergeConflicts(MergeErrs, New->getLocation(),
Old->getLocation());
FunctionProtoType::ExtProtoInfo EPI = NewFPT->getExtProtoInfo();
EPI.FunctionEffects = FunctionEffectsRef(MergedFX);
QualType ModQT = Context.getFunctionType(NewFPT->getReturnType(),
NewFPT->getParamTypes(), EPI);
New->setType(ModQT);
NewQType = New->getType();
// Revise OldQTForComparison to include the merged effects,
// so as not to fail due to differences later.
if (const auto *OldFPT = OldQType->getAs<FunctionProtoType>()) {
EPI = OldFPT->getExtProtoInfo();
EPI.FunctionEffects = FunctionEffectsRef(MergedFX);
OldQTypeForComparison = Context.getFunctionType(
OldFPT->getReturnType(), OldFPT->getParamTypes(), EPI);
}
if (OldFX.empty()) {
// A redeclaration may add the attribute to a previously seen function
// body which needs to be verified.
maybeAddDeclWithEffects(Old, MergedFX);
}
}
}
}
if (getLangOpts().CPlusPlus) {
OldQType = Context.getCanonicalType(Old->getType());
NewQType = Context.getCanonicalType(New->getType());
// Go back to the type source info to compare the declared return types,
// per C++1y [dcl.type.auto]p13:
// Redeclarations or specializations of a function or function template
// with a declared return type that uses a placeholder type shall also
// use that placeholder, not a deduced type.
QualType OldDeclaredReturnType = Old->getDeclaredReturnType();
QualType NewDeclaredReturnType = New->getDeclaredReturnType();
if (!Context.hasSameType(OldDeclaredReturnType, NewDeclaredReturnType) &&
canFullyTypeCheckRedeclaration(New, Old, NewDeclaredReturnType,
OldDeclaredReturnType)) {
QualType ResQT;
if (NewDeclaredReturnType->isObjCObjectPointerType() &&
OldDeclaredReturnType->isObjCObjectPointerType())
// FIXME: This does the wrong thing for a deduced return type.
ResQT = Context.mergeObjCGCQualifiers(NewQType, OldQType);
if (ResQT.isNull()) {
if (New->isCXXClassMember() && New->isOutOfLine())
Diag(New->getLocation(), diag::err_member_def_does_not_match_ret_type)
<< New << New->getReturnTypeSourceRange();
else if (Old->isExternC() && New->isExternC() &&
!Old->hasAttr<OverloadableAttr>() &&
!New->hasAttr<OverloadableAttr>())
Diag(New->getLocation(), diag::err_conflicting_types) << New;
else
Diag(New->getLocation(), diag::err_ovl_diff_return_type)
<< New->getReturnTypeSourceRange();
Diag(OldLocation, PrevDiag) << Old << Old->getType()
<< Old->getReturnTypeSourceRange();
return true;
}
else
NewQType = ResQT;
}
QualType OldReturnType = OldType->getReturnType();
QualType NewReturnType = cast<FunctionType>(NewQType)->getReturnType();
if (OldReturnType != NewReturnType) {
// If this function has a deduced return type and has already been
// defined, copy the deduced value from the old declaration.
AutoType *OldAT = Old->getReturnType()->getContainedAutoType();
if (OldAT && OldAT->isDeduced()) {
QualType DT = OldAT->getDeducedType();
if (DT.isNull()) {
New->setType(SubstAutoTypeDependent(New->getType()));
NewQType = Context.getCanonicalType(SubstAutoTypeDependent(NewQType));
} else {
New->setType(SubstAutoType(New->getType(), DT));
NewQType = Context.getCanonicalType(SubstAutoType(NewQType, DT));
}
}
}
const CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
if (OldMethod && NewMethod) {
// Preserve triviality.
NewMethod->setTrivial(OldMethod->isTrivial());
// MSVC allows explicit template specialization at class scope:
// 2 CXXMethodDecls referring to the same function will be injected.
// We don't want a redeclaration error.
bool IsClassScopeExplicitSpecialization =
OldMethod->isFunctionTemplateSpecialization() &&
NewMethod->isFunctionTemplateSpecialization();
bool isFriend = NewMethod->getFriendObjectKind();
if (!isFriend && NewMethod->getLexicalDeclContext()->isRecord() &&
!IsClassScopeExplicitSpecialization) {
// -- Member function declarations with the same name and the
// same parameter types cannot be overloaded if any of them
// is a static member function declaration.
if (OldMethod->isStatic() != NewMethod->isStatic()) {
Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member);
Diag(OldLocation, PrevDiag) << Old << Old->getType();
return true;
}
// C++ [class.mem]p1:
// [...] A member shall not be declared twice in the
// member-specification, except that a nested class or member
// class template can be declared and then later defined.
if (!inTemplateInstantiation()) {
unsigned NewDiag;
if (isa<CXXConstructorDecl>(OldMethod))
NewDiag = diag::err_constructor_redeclared;
else if (isa<CXXDestructorDecl>(NewMethod))
NewDiag = diag::err_destructor_redeclared;
else if (isa<CXXConversionDecl>(NewMethod))
NewDiag = diag::err_conv_function_redeclared;
else
NewDiag = diag::err_member_redeclared;
Diag(New->getLocation(), NewDiag);
} else {
Diag(New->getLocation(), diag::err_member_redeclared_in_instantiation)
<< New << New->getType();
}
Diag(OldLocation, PrevDiag) << Old << Old->getType();
return true;
// Complain if this is an explicit declaration of a special
// member that was initially declared implicitly.
//
// As an exception, it's okay to befriend such methods in order
// to permit the implicit constructor/destructor/operator calls.
} else if (OldMethod->isImplicit()) {
if (isFriend) {
NewMethod->setImplicit();
} else {
Diag(NewMethod->getLocation(),
diag::err_definition_of_implicitly_declared_member)
<< New << getSpecialMember(OldMethod);
return true;
}
} else if (OldMethod->getFirstDecl()->isExplicitlyDefaulted() && !isFriend) {
Diag(NewMethod->getLocation(),
diag::err_definition_of_explicitly_defaulted_member)
<< getSpecialMember(OldMethod);
return true;
}
}
// C++1z [over.load]p2
// Certain function declarations cannot be overloaded:
// -- Function declarations that differ only in the return type,
// the exception specification, or both cannot be overloaded.
// Check the exception specifications match. This may recompute the type of
// both Old and New if it resolved exception specifications, so grab the
// types again after this. Because this updates the type, we do this before
// any of the other checks below, which may update the "de facto" NewQType
// but do not necessarily update the type of New.
if (CheckEquivalentExceptionSpec(Old, New))
return true;
// C++11 [dcl.attr.noreturn]p1:
// The first declaration of a function shall specify the noreturn
// attribute if any declaration of that function specifies the noreturn
// attribute.
if (const auto *NRA = New->getAttr<CXX11NoReturnAttr>())
if (!Old->hasAttr<CXX11NoReturnAttr>()) {
Diag(NRA->getLocation(), diag::err_attribute_missing_on_first_decl)
<< NRA;
Diag(Old->getLocation(), diag::note_previous_declaration);
}
// C++11 [dcl.attr.depend]p2:
// The first declaration of a function shall specify the
// carries_dependency attribute for its declarator-id if any declaration
// of the function specifies the carries_dependency attribute.
const CarriesDependencyAttr *CDA = New->getAttr<CarriesDependencyAttr>();
if (CDA && !Old->hasAttr<CarriesDependencyAttr>()) {
Diag(CDA->getLocation(),
diag::err_carries_dependency_missing_on_first_decl) << 0/*Function*/;
Diag(Old->getFirstDecl()->getLocation(),
diag::note_carries_dependency_missing_first_decl) << 0/*Function*/;
}
// SYCL 2020 section 5.10.1, "SYCL functions and member functions linkage":
// When a function is declared with SYCL_EXTERNAL, that macro must be
// used on the first declaration of that function in the translation unit.
// Redeclarations of the function in the same translation unit may
// optionally use SYCL_EXTERNAL, but this is not required.
const SYCLExternalAttr *SEA = New->getAttr<SYCLExternalAttr>();
if (SEA && !Old->hasAttr<SYCLExternalAttr>()) {
Diag(SEA->getLocation(), diag::warn_sycl_external_missing_on_first_decl)
<< SEA;
Diag(Old->getLocation(), diag::note_previous_declaration);
}
// (C++98 8.3.5p3):
// All declarations for a function shall agree exactly in both the
// return type and the parameter-type-list.
// We also want to respect all the extended bits except noreturn.
// noreturn should now match unless the old type info didn't have it.
if (!OldTypeInfo.getNoReturn() && NewTypeInfo.getNoReturn()) {
auto *OldType = OldQTypeForComparison->castAs<FunctionProtoType>();
const FunctionType *OldTypeForComparison
= Context.adjustFunctionType(OldType, OldTypeInfo.withNoReturn(true));
OldQTypeForComparison = QualType(OldTypeForComparison, 0);
assert(OldQTypeForComparison.isCanonical());
}
if (haveIncompatibleLanguageLinkages(Old, New)) {
// As a special case, retain the language linkage from previous
// declarations of a friend function as an extension.
//
// This liberal interpretation of C++ [class.friend]p3 matches GCC/MSVC
// and is useful because there's otherwise no way to specify language
// linkage within class scope.
//
// Check cautiously as the friend object kind isn't yet complete.
if (New->getFriendObjectKind() != Decl::FOK_None) {
Diag(New->getLocation(), diag::ext_retained_language_linkage) << New;
Diag(OldLocation, PrevDiag);
} else {
Diag(New->getLocation(), diag::err_different_language_linkage) << New;
Diag(OldLocation, PrevDiag);
return true;
}
}
// HLSL check parameters for matching ABI specifications.
if (getLangOpts().HLSL) {
if (HLSL().CheckCompatibleParameterABI(New, Old))
return true;
// If no errors are generated when checking parameter ABIs we can check if
// the two declarations have the same type ignoring the ABIs and if so,
// the declarations can be merged. This case for merging is only valid in
// HLSL because there are no valid cases of merging mismatched parameter
// ABIs except the HLSL implicit in and explicit in.
if (Context.hasSameFunctionTypeIgnoringParamABI(OldQTypeForComparison,
NewQType))
return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
// Fall through for conflicting redeclarations and redefinitions.
}
// If the function types are compatible, merge the declarations. Ignore the
// exception specifier because it was already checked above in
// CheckEquivalentExceptionSpec, and we don't want follow-on diagnostics
// about incompatible types under -fms-compatibility.
if (Context.hasSameFunctionTypeIgnoringExceptionSpec(OldQTypeForComparison,
NewQType))
return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
// If the types are imprecise (due to dependent constructs in friends or
// local extern declarations), it's OK if they differ. We'll check again
// during instantiation.
if (!canFullyTypeCheckRedeclaration(New, Old, NewQType, OldQType))
return false;
// Fall through for conflicting redeclarations and redefinitions.
}
// C: Function types need to be compatible, not identical. This handles
// duplicate function decls like "void f(int); void f(enum X);" properly.
if (!getLangOpts().CPlusPlus) {
// C99 6.7.5.3p15: ...If one type has a parameter type list and the other
// type is specified by a function definition that contains a (possibly
// empty) identifier list, both shall agree in the number of parameters
// and the type of each parameter shall be compatible with the type that
// results from the application of default argument promotions to the
// type of the corresponding identifier. ...
// This cannot be handled by ASTContext::typesAreCompatible() because that
// doesn't know whether the function type is for a definition or not when
// eventually calling ASTContext::mergeFunctionTypes(). The only situation
// we need to cover here is that the number of arguments agree as the
// default argument promotion rules were already checked by
// ASTContext::typesAreCompatible().
if (Old->hasPrototype() && !New->hasWrittenPrototype() && NewDeclIsDefn &&
Old->getNumParams() != New->getNumParams() && !Old->isImplicit()) {
if (Old->hasInheritedPrototype())
Old = Old->getCanonicalDecl();
Diag(New->getLocation(), diag::err_conflicting_types) << New;
Diag(Old->getLocation(), PrevDiag) << Old << Old->getType();
return true;
}
// If we are merging two functions where only one of them has a prototype,
// we may have enough information to decide to issue a diagnostic that the
// function without a prototype will change behavior in C23. This handles
// cases like:
// void i(); void i(int j);
// void i(int j); void i();
// void i(); void i(int j) {}
// See ActOnFinishFunctionBody() for other cases of the behavior change
// diagnostic. See GetFullTypeForDeclarator() for handling of a function
// type without a prototype.
if (New->hasWrittenPrototype() != Old->hasWrittenPrototype() &&
!New->isImplicit() && !Old->isImplicit()) {
const FunctionDecl *WithProto, *WithoutProto;
if (New->hasWrittenPrototype()) {
WithProto = New;
WithoutProto = Old;
} else {
WithProto = Old;
WithoutProto = New;
}
if (WithProto->getNumParams() != 0) {
if (WithoutProto->getBuiltinID() == 0 && !WithoutProto->isImplicit()) {
// The one without the prototype will be changing behavior in C23, so
// warn about that one so long as it's a user-visible declaration.
bool IsWithoutProtoADef = false, IsWithProtoADef = false;
if (WithoutProto == New)
IsWithoutProtoADef = NewDeclIsDefn;
else
IsWithProtoADef = NewDeclIsDefn;
Diag(WithoutProto->getLocation(),
diag::warn_non_prototype_changes_behavior)
<< IsWithoutProtoADef << (WithoutProto->getNumParams() ? 0 : 1)
<< (WithoutProto == Old) << IsWithProtoADef;
// The reason the one without the prototype will be changing behavior
// is because of the one with the prototype, so note that so long as
// it's a user-visible declaration. There is one exception to this:
// when the new declaration is a definition without a prototype, the
// old declaration with a prototype is not the cause of the issue,
// and that does not need to be noted because the one with a
// prototype will not change behavior in C23.
if (WithProto->getBuiltinID() == 0 && !WithProto->isImplicit() &&
!IsWithoutProtoADef)
Diag(WithProto->getLocation(), diag::note_conflicting_prototype);
}
}
}
if (Context.typesAreCompatible(OldQType, NewQType)) {
const FunctionType *OldFuncType = OldQType->getAs<FunctionType>();
const FunctionType *NewFuncType = NewQType->getAs<FunctionType>();
const FunctionProtoType *OldProto = nullptr;
if (MergeTypeWithOld && isa<FunctionNoProtoType>(NewFuncType) &&
(OldProto = dyn_cast<FunctionProtoType>(OldFuncType))) {
// The old declaration provided a function prototype, but the
// new declaration does not. Merge in the prototype.
assert(!OldProto->hasExceptionSpec() && "Exception spec in C");
NewQType = Context.getFunctionType(NewFuncType->getReturnType(),
OldProto->getParamTypes(),
OldProto->getExtProtoInfo());
New->setType(NewQType);
New->setHasInheritedPrototype();
// Synthesize parameters with the same types.
SmallVector<ParmVarDecl *, 16> Params;
for (const auto &ParamType : OldProto->param_types()) {
ParmVarDecl *Param = ParmVarDecl::Create(
Context, New, SourceLocation(), SourceLocation(), nullptr,
ParamType, /*TInfo=*/nullptr, SC_None, nullptr);
Param->setScopeInfo(0, Params.size());
Param->setImplicit();
Params.push_back(Param);
}
New->setParams(Params);
}
return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
}
}
// Check if the function types are compatible when pointer size address
// spaces are ignored.
if (Context.hasSameFunctionTypeIgnoringPtrSizes(OldQType, NewQType))
return false;
// GNU C permits a K&R definition to follow a prototype declaration
// if the declared types of the parameters in the K&R definition
// match the types in the prototype declaration, even when the
// promoted types of the parameters from the K&R definition differ
// from the types in the prototype. GCC then keeps the types from
// the prototype.
//
// If a variadic prototype is followed by a non-variadic K&R definition,
// the K&R definition becomes variadic. This is sort of an edge case, but
// it's legal per the standard depending on how you read C99 6.7.5.3p15 and
// C99 6.9.1p8.
if (!getLangOpts().CPlusPlus &&
Old->hasPrototype() && !New->hasPrototype() &&
New->getType()->getAs<FunctionProtoType>() &&
Old->getNumParams() == New->getNumParams()) {
SmallVector<QualType, 16> ArgTypes;
SmallVector<GNUCompatibleParamWarning, 16> Warnings;
const FunctionProtoType *OldProto
= Old->getType()->getAs<FunctionProtoType>();
const FunctionProtoType *NewProto
= New->getType()->getAs<FunctionProtoType>();
// Determine whether this is the GNU C extension.
QualType MergedReturn = Context.mergeTypes(OldProto->getReturnType(),
NewProto->getReturnType());
bool LooseCompatible = !MergedReturn.isNull();
for (unsigned Idx = 0, End = Old->getNumParams();
LooseCompatible && Idx != End; ++Idx) {
ParmVarDecl *OldParm = Old->getParamDecl(Idx);
ParmVarDecl *NewParm = New->getParamDecl(Idx);
if (Context.typesAreCompatible(OldParm->getType(),
NewProto->getParamType(Idx))) {
ArgTypes.push_back(NewParm->getType());
} else if (Context.typesAreCompatible(OldParm->getType(),
NewParm->getType(),
/*CompareUnqualified=*/true)) {
GNUCompatibleParamWarning Warn = { OldParm, NewParm,
NewProto->getParamType(Idx) };
Warnings.push_back(Warn);
ArgTypes.push_back(NewParm->getType());
} else
LooseCompatible = false;
}
if (LooseCompatible) {
for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) {
Diag(Warnings[Warn].NewParm->getLocation(),
diag::ext_param_promoted_not_compatible_with_prototype)
<< Warnings[Warn].PromotedType
<< Warnings[Warn].OldParm->getType();
if (Warnings[Warn].OldParm->getLocation().isValid())
Diag(Warnings[Warn].OldParm->getLocation(),
diag::note_previous_declaration);
}
if (MergeTypeWithOld)
New->setType(Context.getFunctionType(MergedReturn, ArgTypes,
OldProto->getExtProtoInfo()));
return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
}
// Fall through to diagnose conflicting types.
}
// A function that has already been declared has been redeclared or
// defined with a different type; show an appropriate diagnostic.
// If the previous declaration was an implicitly-generated builtin
// declaration, then at the very least we should use a specialized note.
unsigned BuiltinID;
if (Old->isImplicit() && (BuiltinID = Old->getBuiltinID())) {
// If it's actually a library-defined builtin function like 'malloc'
// or 'printf', just warn about the incompatible redeclaration.
if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) {
Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New;
Diag(OldLocation, diag::note_previous_builtin_declaration)
<< Old << Old->getType();
return false;
}
PrevDiag = diag::note_previous_builtin_declaration;
}
Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName();
Diag(OldLocation, PrevDiag) << Old << Old->getType();
return true;
}
bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old,
Scope *S, bool MergeTypeWithOld) {
// Merge the attributes
mergeDeclAttributes(New, Old);
// Merge "pure" flag.
if (Old->isPureVirtual())
New->setIsPureVirtual();
// Merge "used" flag.
if (Old->getMostRecentDecl()->isUsed(false))
New->setIsUsed();
// Merge attributes from the parameters. These can mismatch with K&R
// declarations.
if (New->getNumParams() == Old->getNumParams())
for (unsigned i = 0, e = New->getNumParams(); i != e; ++i) {
ParmVarDecl *NewParam = New->getParamDecl(i);
ParmVarDecl *OldParam = Old->getParamDecl(i);
mergeParamDeclAttributes(NewParam, OldParam, *this);
mergeParamDeclTypes(NewParam, OldParam, *this);
}
if (getLangOpts().CPlusPlus)
return MergeCXXFunctionDecl(New, Old, S);
// Merge the function types so the we get the composite types for the return
// and argument types. Per C11 6.2.7/4, only update the type if the old decl
// was visible.
QualType Merged = Context.mergeTypes(Old->getType(), New->getType());
if (!Merged.isNull() && MergeTypeWithOld)
New->setType(Merged);
return false;
}
void Sema::mergeObjCMethodDecls(ObjCMethodDecl *newMethod,
ObjCMethodDecl *oldMethod) {
// Merge the attributes, including deprecated/unavailable
AvailabilityMergeKind MergeKind =
isa<ObjCProtocolDecl>(oldMethod->getDeclContext())
? (oldMethod->isOptional()
? AvailabilityMergeKind::OptionalProtocolImplementation
: AvailabilityMergeKind::ProtocolImplementation)
: isa<ObjCImplDecl>(newMethod->getDeclContext())
? AvailabilityMergeKind::Redeclaration
: AvailabilityMergeKind::Override;
mergeDeclAttributes(newMethod, oldMethod, MergeKind);
// Merge attributes from the parameters.
ObjCMethodDecl::param_const_iterator oi = oldMethod->param_begin(),
oe = oldMethod->param_end();
for (ObjCMethodDecl::param_iterator
ni = newMethod->param_begin(), ne = newMethod->param_end();
ni != ne && oi != oe; ++ni, ++oi)
mergeParamDeclAttributes(*ni, *oi, *this);
ObjC().CheckObjCMethodOverride(newMethod, oldMethod);
}
static void diagnoseVarDeclTypeMismatch(Sema &S, VarDecl *New, VarDecl* Old) {
assert(!S.Context.hasSameType(New->getType(), Old->getType()));
S.Diag(New->getLocation(), New->isThisDeclarationADefinition()
? diag::err_redefinition_different_type
: diag::err_redeclaration_different_type)
<< New->getDeclName() << New->getType() << Old->getType();
diag::kind PrevDiag;
SourceLocation OldLocation;
std::tie(PrevDiag, OldLocation)
= getNoteDiagForInvalidRedeclaration(Old, New);
S.Diag(OldLocation, PrevDiag) << Old << Old->getType();
New->setInvalidDecl();
}
void Sema::MergeVarDeclTypes(VarDecl *New, VarDecl *Old,
bool MergeTypeWithOld) {
if (New->isInvalidDecl() || Old->isInvalidDecl() || New->getType()->containsErrors() || Old->getType()->containsErrors())
return;
QualType MergedT;
if (getLangOpts().CPlusPlus) {
if (New->getType()->isUndeducedType()) {
// We don't know what the new type is until the initializer is attached.
return;
} else if (Context.hasSameType(New->getType(), Old->getType())) {
// These could still be something that needs exception specs checked.
return MergeVarDeclExceptionSpecs(New, Old);
}
// C++ [basic.link]p10:
// [...] the types specified by all declarations referring to a given
// object or function shall be identical, except that declarations for an
// array object can specify array types that differ by the presence or
// absence of a major array bound (8.3.4).
else if (Old->getType()->isArrayType() && New->getType()->isArrayType()) {
const ArrayType *OldArray = Context.getAsArrayType(Old->getType());
const ArrayType *NewArray = Context.getAsArrayType(New->getType());
// We are merging a variable declaration New into Old. If it has an array
// bound, and that bound differs from Old's bound, we should diagnose the
// mismatch.
if (!NewArray->isIncompleteArrayType() && !NewArray->isDependentType()) {
for (VarDecl *PrevVD = Old->getMostRecentDecl(); PrevVD;
PrevVD = PrevVD->getPreviousDecl()) {
QualType PrevVDTy = PrevVD->getType();
if (PrevVDTy->isIncompleteArrayType() || PrevVDTy->isDependentType())
continue;
if (!Context.hasSameType(New->getType(), PrevVDTy))
return diagnoseVarDeclTypeMismatch(*this, New, PrevVD);
}
}
if (OldArray->isIncompleteArrayType() && NewArray->isArrayType()) {
if (Context.hasSameType(OldArray->getElementType(),
NewArray->getElementType()))
MergedT = New->getType();
}
// FIXME: Check visibility. New is hidden but has a complete type. If New
// has no array bound, it should not inherit one from Old, if Old is not
// visible.
else if (OldArray->isArrayType() && NewArray->isIncompleteArrayType()) {
if (Context.hasSameType(OldArray->getElementType(),
NewArray->getElementType()))
MergedT = Old->getType();
}
}
else if (New->getType()->isObjCObjectPointerType() &&
Old->getType()->isObjCObjectPointerType()) {
MergedT = Context.mergeObjCGCQualifiers(New->getType(),
Old->getType());
}
} else {
// C 6.2.7p2:
// All declarations that refer to the same object or function shall have
// compatible type.
MergedT = Context.mergeTypes(New->getType(), Old->getType());
}
if (MergedT.isNull()) {
// It's OK if we couldn't merge types if either type is dependent, for a
// block-scope variable. In other cases (static data members of class
// templates, variable templates, ...), we require the types to be
// equivalent.
// FIXME: The C++ standard doesn't say anything about this.
if ((New->getType()->isDependentType() ||
Old->getType()->isDependentType()) && New->isLocalVarDecl()) {
// If the old type was dependent, we can't merge with it, so the new type
// becomes dependent for now. We'll reproduce the original type when we
// instantiate the TypeSourceInfo for the variable.
if (!New->getType()->isDependentType() && MergeTypeWithOld)
New->setType(Context.DependentTy);
return;
}
return diagnoseVarDeclTypeMismatch(*this, New, Old);
}
// Don't actually update the type on the new declaration if the old
// declaration was an extern declaration in a different scope.
if (MergeTypeWithOld)
New->setType(MergedT);
}
static bool mergeTypeWithPrevious(Sema &S, VarDecl *NewVD, VarDecl *OldVD,
LookupResult &Previous) {
// C11 6.2.7p4:
// For an identifier with internal or external linkage declared
// in a scope in which a prior declaration of that identifier is
// visible, if the prior declaration specifies internal or
// external linkage, the type of the identifier at the later
// declaration becomes the composite type.
//
// If the variable isn't visible, we do not merge with its type.
if (Previous.isShadowed())
return false;
if (S.getLangOpts().CPlusPlus) {
// C++11 [dcl.array]p3:
// If there is a preceding declaration of the entity in the same
// scope in which the bound was specified, an omitted array bound
// is taken to be the same as in that earlier declaration.
return NewVD->isPreviousDeclInSameBlockScope() ||
(!OldVD->getLexicalDeclContext()->isFunctionOrMethod() &&
!NewVD->getLexicalDeclContext()->isFunctionOrMethod());
} else {
// If the old declaration was function-local, don't merge with its
// type unless we're in the same function.
return !OldVD->getLexicalDeclContext()->isFunctionOrMethod() ||
OldVD->getLexicalDeclContext() == NewVD->getLexicalDeclContext();
}
}
void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) {
// If the new decl is already invalid, don't do any other checking.
if (New->isInvalidDecl())
return;
if (!shouldLinkPossiblyHiddenDecl(Previous, New))
return;
VarTemplateDecl *NewTemplate = New->getDescribedVarTemplate();
// Verify the old decl was also a variable or variable template.
VarDecl *Old = nullptr;
VarTemplateDecl *OldTemplate = nullptr;
if (Previous.isSingleResult()) {
if (NewTemplate) {
OldTemplate = dyn_cast<VarTemplateDecl>(Previous.getFoundDecl());
Old = OldTemplate ? OldTemplate->getTemplatedDecl() : nullptr;
if (auto *Shadow =
dyn_cast<UsingShadowDecl>(Previous.getRepresentativeDecl()))
if (checkUsingShadowRedecl<VarTemplateDecl>(*this, Shadow, NewTemplate))
return New->setInvalidDecl();
} else {
Old = dyn_cast<VarDecl>(Previous.getFoundDecl());
if (auto *Shadow =
dyn_cast<UsingShadowDecl>(Previous.getRepresentativeDecl()))
if (checkUsingShadowRedecl<VarDecl>(*this, Shadow, New))
return New->setInvalidDecl();
}
}
if (!Old) {
Diag(New->getLocation(), diag::err_redefinition_different_kind)
<< New->getDeclName();
notePreviousDefinition(Previous.getRepresentativeDecl(),
New->getLocation());
return New->setInvalidDecl();
}
// If the old declaration was found in an inline namespace and the new
// declaration was qualified, update the DeclContext to match.
adjustDeclContextForDeclaratorDecl(New, Old);
// Ensure the template parameters are compatible.
if (NewTemplate &&
!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
OldTemplate->getTemplateParameters(),
/*Complain=*/true, TPL_TemplateMatch))
return New->setInvalidDecl();
// C++ [class.mem]p1:
// A member shall not be declared twice in the member-specification [...]
//
// Here, we need only consider static data members.
if (Old->isStaticDataMember() && !New->isOutOfLine()) {
Diag(New->getLocation(), diag::err_duplicate_member)
<< New->getIdentifier();
Diag(Old->getLocation(), diag::note_previous_declaration);
New->setInvalidDecl();
}
mergeDeclAttributes(New, Old);
// Warn if an already-defined variable is made a weak_import in a subsequent
// declaration
if (New->hasAttr<WeakImportAttr>())
for (auto *D = Old; D; D = D->getPreviousDecl()) {
if (D->isThisDeclarationADefinition() != VarDecl::DeclarationOnly) {
Diag(New->getLocation(), diag::warn_weak_import) << New->getDeclName();
Diag(D->getLocation(), diag::note_previous_definition);
// Remove weak_import attribute on new declaration.
New->dropAttr<WeakImportAttr>();
break;
}
}
if (const auto *ILA = New->getAttr<InternalLinkageAttr>())
if (!Old->hasAttr<InternalLinkageAttr>()) {
Diag(New->getLocation(), diag::err_attribute_missing_on_first_decl)
<< ILA;
Diag(Old->getLocation(), diag::note_previous_declaration);
New->dropAttr<InternalLinkageAttr>();
}
// Merge the types.
VarDecl *MostRecent = Old->getMostRecentDecl();
if (MostRecent != Old) {
MergeVarDeclTypes(New, MostRecent,
mergeTypeWithPrevious(*this, New, MostRecent, Previous));
if (New->isInvalidDecl())
return;
}
MergeVarDeclTypes(New, Old, mergeTypeWithPrevious(*this, New, Old, Previous));
if (New->isInvalidDecl())
return;
diag::kind PrevDiag;
SourceLocation OldLocation;
std::tie(PrevDiag, OldLocation) =
getNoteDiagForInvalidRedeclaration(Old, New);
// [dcl.stc]p8: Check if we have a non-static decl followed by a static.
if (New->getStorageClass() == SC_Static &&
!New->isStaticDataMember() &&
Old->hasExternalFormalLinkage()) {
if (getLangOpts().MicrosoftExt) {
Diag(New->getLocation(), diag::ext_static_non_static)
<< New->getDeclName();
Diag(OldLocation, PrevDiag);
} else {
Diag(New->getLocation(), diag::err_static_non_static)
<< New->getDeclName();
Diag(OldLocation, PrevDiag);
return New->setInvalidDecl();
}
}
// C99 6.2.2p4:
// For an identifier declared with the storage-class specifier
// extern in a scope in which a prior declaration of that
// identifier is visible,23) if the prior declaration specifies
// internal or external linkage, the linkage of the identifier at
// the later declaration is the same as the linkage specified at
// the prior declaration. If no prior declaration is visible, or
// if the prior declaration specifies no linkage, then the
// identifier has external linkage.
if (New->hasExternalStorage() && Old->hasLinkage())
/* Okay */;
else if (New->getCanonicalDecl()->getStorageClass() != SC_Static &&
!New->isStaticDataMember() &&
Old->getCanonicalDecl()->getStorageClass() == SC_Static) {
Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName();
Diag(OldLocation, PrevDiag);
return New->setInvalidDecl();
}
// Check if extern is followed by non-extern and vice-versa.
if (New->hasExternalStorage() &&
!Old->hasLinkage() && Old->isLocalVarDeclOrParm()) {
Diag(New->getLocation(), diag::err_extern_non_extern) << New->getDeclName();
Diag(OldLocation, PrevDiag);
return New->setInvalidDecl();
}
if (Old->hasLinkage() && New->isLocalVarDeclOrParm() &&
!New->hasExternalStorage()) {
Diag(New->getLocation(), diag::err_non_extern_extern) << New->getDeclName();
Diag(OldLocation, PrevDiag);
return New->setInvalidDecl();
}
if (CheckRedeclarationInModule(New, Old))
return;
// Variables with external linkage are analyzed in FinalizeDeclaratorGroup.
// FIXME: The test for external storage here seems wrong? We still
// need to check for mismatches.
if (!New->hasExternalStorage() && !New->isFileVarDecl() &&
// Don't complain about out-of-line definitions of static members.
!(Old->getLexicalDeclContext()->isRecord() &&
!New->getLexicalDeclContext()->isRecord())) {
Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName();
Diag(OldLocation, PrevDiag);
return New->setInvalidDecl();
}
if (New->isInline() && !Old->getMostRecentDecl()->isInline()) {
if (VarDecl *Def = Old->getDefinition()) {
// C++1z [dcl.fcn.spec]p4:
// If the definition of a variable appears in a translation unit before
// its first declaration as inline, the program is ill-formed.
Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
Diag(Def->getLocation(), diag::note_previous_definition);
}
}
// If this redeclaration makes the variable inline, we may need to add it to
// UndefinedButUsed.
if (!Old->isInline() && New->isInline() && Old->isUsed(false) &&
!Old->getDefinition() && !New->isThisDeclarationADefinition() &&
!Old->isInAnotherModuleUnit())
UndefinedButUsed.insert(std::make_pair(Old->getCanonicalDecl(),
SourceLocation()));
if (New->getTLSKind() != Old->getTLSKind()) {
if (!Old->getTLSKind()) {
Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName();
Diag(OldLocation, PrevDiag);
} else if (!New->getTLSKind()) {
Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName();
Diag(OldLocation, PrevDiag);
} else {
// Do not allow redeclaration to change the variable between requiring
// static and dynamic initialization.
// FIXME: GCC allows this, but uses the TLS keyword on the first
// declaration to determine the kind. Do we need to be compatible here?
Diag(New->getLocation(), diag::err_thread_thread_different_kind)
<< New->getDeclName() << (New->getTLSKind() == VarDecl::TLS_Dynamic);
Diag(OldLocation, PrevDiag);
}
}
// C++ doesn't have tentative definitions, so go right ahead and check here.
if (getLangOpts().CPlusPlus) {
if (Old->isStaticDataMember() && Old->getCanonicalDecl()->isInline() &&
Old->getCanonicalDecl()->isConstexpr()) {
// This definition won't be a definition any more once it's been merged.
Diag(New->getLocation(),
diag::warn_deprecated_redundant_constexpr_static_def);
} else if (New->isThisDeclarationADefinition() == VarDecl::Definition) {
VarDecl *Def = Old->getDefinition();
if (Def && checkVarDeclRedefinition(Def, New))
return;
}
} else {
// C++ may not have a tentative definition rule, but it has a different
// rule about what constitutes a definition in the first place. See
// [basic.def]p2 for details, but the basic idea is: if the old declaration
// contains the extern specifier and doesn't have an initializer, it's fine
// in C++.
if (Old->getStorageClass() != SC_Extern || Old->hasInit()) {
Diag(New->getLocation(), diag::warn_cxx_compat_tentative_definition)
<< New;
Diag(Old->getLocation(), diag::note_previous_declaration);
}
}
if (haveIncompatibleLanguageLinkages(Old, New)) {
Diag(New->getLocation(), diag::err_different_language_linkage) << New;
Diag(OldLocation, PrevDiag);
New->setInvalidDecl();
return;
}
// Merge "used" flag.
if (Old->getMostRecentDecl()->isUsed(false))
New->setIsUsed();
// Keep a chain of previous declarations.
New->setPreviousDecl(Old);
if (NewTemplate)
NewTemplate->setPreviousDecl(OldTemplate);
// Inherit access appropriately.
New->setAccess(Old->getAccess());
if (NewTemplate)
NewTemplate->setAccess(New->getAccess());
if (Old->isInline())
New->setImplicitlyInline();
}
void Sema::notePreviousDefinition(const NamedDecl *Old, SourceLocation New) {
SourceManager &SrcMgr = getSourceManager();
auto FNewDecLoc = SrcMgr.getDecomposedLoc(New);
auto FOldDecLoc = SrcMgr.getDecomposedLoc(Old->getLocation());
auto *FNew = SrcMgr.getFileEntryForID(FNewDecLoc.first);
auto FOld = SrcMgr.getFileEntryRefForID(FOldDecLoc.first);
auto &HSI = PP.getHeaderSearchInfo();
StringRef HdrFilename =
SrcMgr.getFilename(SrcMgr.getSpellingLoc(Old->getLocation()));
auto noteFromModuleOrInclude = [&](Module *Mod,
SourceLocation IncLoc) -> bool {
// Redefinition errors with modules are common with non modular mapped
// headers, example: a non-modular header H in module A that also gets
// included directly in a TU. Pointing twice to the same header/definition
// is confusing, try to get better diagnostics when modules is on.
if (IncLoc.isValid()) {
if (Mod) {
Diag(IncLoc, diag::note_redefinition_modules_same_file)
<< HdrFilename.str() << Mod->getFullModuleName();
if (!Mod->DefinitionLoc.isInvalid())
Diag(Mod->DefinitionLoc, diag::note_defined_here)
<< Mod->getFullModuleName();
} else {
Diag(IncLoc, diag::note_redefinition_include_same_file)
<< HdrFilename.str();
}
return true;
}
return false;
};
// Is it the same file and same offset? Provide more information on why
// this leads to a redefinition error.
if (FNew == FOld && FNewDecLoc.second == FOldDecLoc.second) {
SourceLocation OldIncLoc = SrcMgr.getIncludeLoc(FOldDecLoc.first);
SourceLocation NewIncLoc = SrcMgr.getIncludeLoc(FNewDecLoc.first);
bool EmittedDiag =
noteFromModuleOrInclude(Old->getOwningModule(), OldIncLoc);
EmittedDiag |= noteFromModuleOrInclude(getCurrentModule(), NewIncLoc);
// If the header has no guards, emit a note suggesting one.
if (FOld && !HSI.isFileMultipleIncludeGuarded(*FOld))
Diag(Old->getLocation(), diag::note_use_ifdef_guards);
if (EmittedDiag)
return;
}
// Redefinition coming from different files or couldn't do better above.
if (Old->getLocation().isValid())
Diag(Old->getLocation(), diag::note_previous_definition);
}
bool Sema::checkVarDeclRedefinition(VarDecl *Old, VarDecl *New) {
if (!hasVisibleDefinition(Old) &&
(New->getFormalLinkage() == Linkage::Internal || New->isInline() ||
isa<VarTemplateSpecializationDecl>(New) ||
New->getDescribedVarTemplate() || New->getNumTemplateParameterLists() ||
New->getDeclContext()->isDependentContext() ||
New->hasAttr<SelectAnyAttr>())) {
// The previous definition is hidden, and multiple definitions are
// permitted (in separate TUs). Demote this to a declaration.
New->demoteThisDefinitionToDeclaration();
// Make the canonical definition visible.
if (auto *OldTD = Old->getDescribedVarTemplate())
makeMergedDefinitionVisible(OldTD);
makeMergedDefinitionVisible(Old);
return false;
} else {
Diag(New->getLocation(), diag::err_redefinition) << New;
notePreviousDefinition(Old, New->getLocation());
New->setInvalidDecl();
return true;
}
}
Decl *Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS,
DeclSpec &DS,
const ParsedAttributesView &DeclAttrs,
RecordDecl *&AnonRecord) {
return ParsedFreeStandingDeclSpec(
S, AS, DS, DeclAttrs, MultiTemplateParamsArg(), false, AnonRecord);
}
// The MS ABI changed between VS2013 and VS2015 with regard to numbers used to
// disambiguate entities defined in different scopes.
// While the VS2015 ABI fixes potential miscompiles, it is also breaks
// compatibility.
// We will pick our mangling number depending on which version of MSVC is being
// targeted.
static unsigned getMSManglingNumber(const LangOptions &LO, Scope *S) {
return LO.isCompatibleWithMSVC(LangOptions::MSVC2015)
? S->getMSCurManglingNumber()
: S->getMSLastManglingNumber();
}
void Sema::handleTagNumbering(const TagDecl *Tag, Scope *TagScope) {
if (!Context.getLangOpts().CPlusPlus)
return;
if (isa<CXXRecordDecl>(Tag->getParent())) {
// If this tag is the direct child of a class, number it if
// it is anonymous.
if (!Tag->getName().empty() || Tag->getTypedefNameForAnonDecl())
return;
MangleNumberingContext &MCtx =
Context.getManglingNumberContext(Tag->getParent());
Context.setManglingNumber(
Tag, MCtx.getManglingNumber(
Tag, getMSManglingNumber(getLangOpts(), TagScope)));
return;
}
// If this tag isn't a direct child of a class, number it if it is local.
MangleNumberingContext *MCtx;
Decl *ManglingContextDecl;
std::tie(MCtx, ManglingContextDecl) =
getCurrentMangleNumberContext(Tag->getDeclContext());
if (MCtx) {
Context.setManglingNumber(
Tag, MCtx->getManglingNumber(
Tag, getMSManglingNumber(getLangOpts(), TagScope)));
}
}
namespace {
struct NonCLikeKind {
enum {
None,
BaseClass,
DefaultMemberInit,
Lambda,
Friend,
OtherMember,
Invalid,
} Kind = None;
SourceRange Range;
explicit operator bool() { return Kind != None; }
};
}
/// Determine whether a class is C-like, according to the rules of C++
/// [dcl.typedef] for anonymous classes with typedef names for linkage.
static NonCLikeKind getNonCLikeKindForAnonymousStruct(const CXXRecordDecl *RD) {
if (RD->isInvalidDecl())
return {NonCLikeKind::Invalid, {}};
// C++ [dcl.typedef]p9: [P1766R1]
// An unnamed class with a typedef name for linkage purposes shall not
//
// -- have any base classes
if (RD->getNumBases())
return {NonCLikeKind::BaseClass,
SourceRange(RD->bases_begin()->getBeginLoc(),
RD->bases_end()[-1].getEndLoc())};
bool Invalid = false;
for (Decl *D : RD->decls()) {
// Don't complain about things we already diagnosed.
if (D->isInvalidDecl()) {
Invalid = true;
continue;
}
// -- have any [...] default member initializers
if (auto *FD = dyn_cast<FieldDecl>(D)) {
if (FD->hasInClassInitializer()) {
auto *Init = FD->getInClassInitializer();
return {NonCLikeKind::DefaultMemberInit,
Init ? Init->getSourceRange() : D->getSourceRange()};
}
continue;
}
// FIXME: We don't allow friend declarations. This violates the wording of
// P1766, but not the intent.
if (isa<FriendDecl>(D))
return {NonCLikeKind::Friend, D->getSourceRange()};
// -- declare any members other than non-static data members, member
// enumerations, or member classes,
if (isa<StaticAssertDecl>(D) || isa<IndirectFieldDecl>(D) ||
isa<EnumDecl>(D))
continue;
auto *MemberRD = dyn_cast<CXXRecordDecl>(D);
if (!MemberRD) {
if (D->isImplicit())
continue;
return {NonCLikeKind::OtherMember, D->getSourceRange()};
}
// -- contain a lambda-expression,
if (MemberRD->isLambda())
return {NonCLikeKind::Lambda, MemberRD->getSourceRange()};
// and all member classes shall also satisfy these requirements
// (recursively).
if (MemberRD->isThisDeclarationADefinition()) {
if (auto Kind = getNonCLikeKindForAnonymousStruct(MemberRD))
return Kind;
}
}
return {Invalid ? NonCLikeKind::Invalid : NonCLikeKind::None, {}};
}
void Sema::setTagNameForLinkagePurposes(TagDecl *TagFromDeclSpec,
TypedefNameDecl *NewTD) {
if (TagFromDeclSpec->isInvalidDecl())
return;
// Do nothing if the tag already has a name for linkage purposes.
if (TagFromDeclSpec->hasNameForLinkage())
return;
// A well-formed anonymous tag must always be a TagUseKind::Definition.
assert(TagFromDeclSpec->isThisDeclarationADefinition());
// The type must match the tag exactly; no qualifiers allowed.
if (!Context.hasSameType(NewTD->getUnderlyingType(),
Context.getCanonicalTagType(TagFromDeclSpec))) {
if (getLangOpts().CPlusPlus)
Context.addTypedefNameForUnnamedTagDecl(TagFromDeclSpec, NewTD);
return;
}
// C++ [dcl.typedef]p9: [P1766R1, applied as DR]
// An unnamed class with a typedef name for linkage purposes shall [be
// C-like].
//
// FIXME: Also diagnose if we've already computed the linkage. That ideally
// shouldn't happen, but there are constructs that the language rule doesn't
// disallow for which we can't reasonably avoid computing linkage early.
const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TagFromDeclSpec);
NonCLikeKind NonCLike = RD ? getNonCLikeKindForAnonymousStruct(RD)
: NonCLikeKind();
bool ChangesLinkage = TagFromDeclSpec->hasLinkageBeenComputed();
if (NonCLike || ChangesLinkage) {
if (NonCLike.Kind == NonCLikeKind::Invalid)
return;
unsigned DiagID = diag::ext_non_c_like_anon_struct_in_typedef;
if (ChangesLinkage) {
// If the linkage changes, we can't accept this as an extension.
if (NonCLike.Kind == NonCLikeKind::None)
DiagID = diag::err_typedef_changes_linkage;
else
DiagID = diag::err_non_c_like_anon_struct_in_typedef;
}
SourceLocation FixitLoc =
getLocForEndOfToken(TagFromDeclSpec->getInnerLocStart());
llvm::SmallString<40> TextToInsert;
TextToInsert += ' ';
TextToInsert += NewTD->getIdentifier()->getName();
Diag(FixitLoc, DiagID)
<< isa<TypeAliasDecl>(NewTD)
<< FixItHint::CreateInsertion(FixitLoc, TextToInsert);
if (NonCLike.Kind != NonCLikeKind::None) {
Diag(NonCLike.Range.getBegin(), diag::note_non_c_like_anon_struct)
<< NonCLike.Kind - 1 << NonCLike.Range;
}
Diag(NewTD->getLocation(), diag::note_typedef_for_linkage_here)
<< NewTD << isa<TypeAliasDecl>(NewTD);
if (ChangesLinkage)
return;
}
// Otherwise, set this as the anon-decl typedef for the tag.
TagFromDeclSpec->setTypedefNameForAnonDecl(NewTD);
// Now that we have a name for the tag, process API notes again.
ProcessAPINotes(TagFromDeclSpec);
}
static unsigned GetDiagnosticTypeSpecifierID(const DeclSpec &DS) {
DeclSpec::TST T = DS.getTypeSpecType();
switch (T) {
case DeclSpec::TST_class:
return 0;
case DeclSpec::TST_struct:
return 1;
case DeclSpec::TST_interface:
return 2;
case DeclSpec::TST_union:
return 3;
case DeclSpec::TST_enum:
if (const auto *ED = dyn_cast<EnumDecl>(DS.getRepAsDecl())) {
if (ED->isScopedUsingClassTag())
return 5;
if (ED->isScoped())
return 6;
}
return 4;
default:
llvm_unreachable("unexpected type specifier");
}
}
Decl *Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS,
DeclSpec &DS,
const ParsedAttributesView &DeclAttrs,
MultiTemplateParamsArg TemplateParams,
bool IsExplicitInstantiation,
RecordDecl *&AnonRecord,
SourceLocation EllipsisLoc) {
Decl *TagD = nullptr;
TagDecl *Tag = nullptr;
if (DS.getTypeSpecType() == DeclSpec::TST_class ||
DS.getTypeSpecType() == DeclSpec::TST_struct ||
DS.getTypeSpecType() == DeclSpec::TST_interface ||
DS.getTypeSpecType() == DeclSpec::TST_union ||
DS.getTypeSpecType() == DeclSpec::TST_enum) {
TagD = DS.getRepAsDecl();
if (!TagD) // We probably had an error
return nullptr;
// Note that the above type specs guarantee that the
// type rep is a Decl, whereas in many of the others
// it's a Type.
if (isa<TagDecl>(TagD))
Tag = cast<TagDecl>(TagD);
else if (ClassTemplateDecl *CTD = dyn_cast<ClassTemplateDecl>(TagD))
Tag = CTD->getTemplatedDecl();
}
if (Tag) {
handleTagNumbering(Tag, S);
Tag->setFreeStanding();
if (Tag->isInvalidDecl())
return Tag;
}
if (unsigned TypeQuals = DS.getTypeQualifiers()) {
// Enforce C99 6.7.3p2: "Types other than pointer types derived from object
// or incomplete types shall not be restrict-qualified."
if (TypeQuals & DeclSpec::TQ_restrict)
Diag(DS.getRestrictSpecLoc(),
diag::err_typecheck_invalid_restrict_not_pointer_noarg)
<< DS.getSourceRange();
}
if (DS.isInlineSpecified())
Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function)
<< getLangOpts().CPlusPlus17;
if (DS.hasConstexprSpecifier()) {
// C++0x [dcl.constexpr]p1: constexpr can only be applied to declarations
// and definitions of functions and variables.
// C++2a [dcl.constexpr]p1: The consteval specifier shall be applied only to
// the declaration of a function or function template
if (Tag)
Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_tag)
<< GetDiagnosticTypeSpecifierID(DS)
<< static_cast<int>(DS.getConstexprSpecifier());
else if (getLangOpts().C23)
Diag(DS.getConstexprSpecLoc(), diag::err_c23_constexpr_not_variable);
else
Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_wrong_decl_kind)
<< static_cast<int>(DS.getConstexprSpecifier());
// Don't emit warnings after this error.
return TagD;
}
DiagnoseFunctionSpecifiers(DS);
if (DS.isFriendSpecified()) {
// If we're dealing with a decl but not a TagDecl, assume that
// whatever routines created it handled the friendship aspect.
if (TagD && !Tag)
return nullptr;
return ActOnFriendTypeDecl(S, DS, TemplateParams, EllipsisLoc);
}
assert(EllipsisLoc.isInvalid() &&
"Friend ellipsis but not friend-specified?");
// Track whether this decl-specifier declares anything.
bool DeclaresAnything = true;
// Handle anonymous struct definitions.
if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) {
if (!Record->getDeclName() && Record->isCompleteDefinition() &&
DS.getStorageClassSpec() != DeclSpec::SCS_typedef) {
if (getLangOpts().CPlusPlus ||
Record->getDeclContext()->isRecord()) {
// If CurContext is a DeclContext that can contain statements,
// RecursiveASTVisitor won't visit the decls that
// BuildAnonymousStructOrUnion() will put into CurContext.
// Also store them here so that they can be part of the
// DeclStmt that gets created in this case.
// FIXME: Also return the IndirectFieldDecls created by
// BuildAnonymousStructOr union, for the same reason?
if (CurContext->isFunctionOrMethod())
AnonRecord = Record;
return BuildAnonymousStructOrUnion(S, DS, AS, Record,
Context.getPrintingPolicy());
}
DeclaresAnything = false;
}
}
// C11 6.7.2.1p2:
// A struct-declaration that does not declare an anonymous structure or
// anonymous union shall contain a struct-declarator-list.
//
// This rule also existed in C89 and C99; the grammar for struct-declaration
// did not permit a struct-declaration without a struct-declarator-list.
if (!getLangOpts().CPlusPlus && CurContext->isRecord() &&
DS.getStorageClassSpec() == DeclSpec::SCS_unspecified) {
// Check for Microsoft C extension: anonymous struct/union member.
// Handle 2 kinds of anonymous struct/union:
// struct STRUCT;
// union UNION;
// and
// STRUCT_TYPE; <- where STRUCT_TYPE is a typedef struct.
// UNION_TYPE; <- where UNION_TYPE is a typedef union.
if ((Tag && Tag->getDeclName()) ||
DS.getTypeSpecType() == DeclSpec::TST_typename) {
RecordDecl *Record = Tag ? dyn_cast<RecordDecl>(Tag)
: DS.getRepAsType().get()->getAsRecordDecl();
if (Record && getLangOpts().MicrosoftExt) {
Diag(DS.getBeginLoc(), diag::ext_ms_anonymous_record)
<< Record->isUnion() << DS.getSourceRange();
return BuildMicrosoftCAnonymousStruct(S, DS, Record);
}
DeclaresAnything = false;
}
}
// Skip all the checks below if we have a type error.
if (DS.getTypeSpecType() == DeclSpec::TST_error ||
(TagD && TagD->isInvalidDecl()))
return TagD;
if (getLangOpts().CPlusPlus &&
DS.getStorageClassSpec() != DeclSpec::SCS_typedef)
if (EnumDecl *Enum = dyn_cast_or_null<EnumDecl>(Tag))
if (Enum->enumerators().empty() && !Enum->getIdentifier() &&
!Enum->isInvalidDecl())
DeclaresAnything = false;
if (!DS.isMissingDeclaratorOk()) {
// Customize diagnostic for a typedef missing a name.
if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
Diag(DS.getBeginLoc(), diag::ext_typedef_without_a_name)
<< DS.getSourceRange();
else
DeclaresAnything = false;
}
if (DS.isModulePrivateSpecified() &&
Tag && Tag->getDeclContext()->isFunctionOrMethod())
Diag(DS.getModulePrivateSpecLoc(), diag::err_module_private_local_class)
<< Tag->getTagKind()
<< FixItHint::CreateRemoval(DS.getModulePrivateSpecLoc());
ActOnDocumentableDecl(TagD);
// C 6.7/2:
// A declaration [...] shall declare at least a declarator [...], a tag,
// or the members of an enumeration.
// C++ [dcl.dcl]p3:
// [If there are no declarators], and except for the declaration of an
// unnamed bit-field, the decl-specifier-seq shall introduce one or more
// names into the program, or shall redeclare a name introduced by a
// previous declaration.
if (!DeclaresAnything) {
// In C, we allow this as a (popular) extension / bug. Don't bother
// producing further diagnostics for redundant qualifiers after this.
Diag(DS.getBeginLoc(), (IsExplicitInstantiation || !TemplateParams.empty())
? diag::err_no_declarators
: diag::ext_no_declarators)
<< DS.getSourceRange();
return TagD;
}
// C++ [dcl.stc]p1:
// If a storage-class-specifier appears in a decl-specifier-seq, [...] the
// init-declarator-list of the declaration shall not be empty.
// C++ [dcl.fct.spec]p1:
// If a cv-qualifier appears in a decl-specifier-seq, the
// init-declarator-list of the declaration shall not be empty.
//
// Spurious qualifiers here appear to be valid in C.
unsigned DiagID = diag::warn_standalone_specifier;
if (getLangOpts().CPlusPlus)
DiagID = diag::ext_standalone_specifier;
// Note that a linkage-specification sets a storage class, but
// 'extern "C" struct foo;' is actually valid and not theoretically
// useless.
if (DeclSpec::SCS SCS = DS.getStorageClassSpec()) {
if (SCS == DeclSpec::SCS_mutable)
// Since mutable is not a viable storage class specifier in C, there is
// no reason to treat it as an extension. Instead, diagnose as an error.
Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_nonmember);
else if (!DS.isExternInLinkageSpec() && SCS != DeclSpec::SCS_typedef)
Diag(DS.getStorageClassSpecLoc(), DiagID)
<< DeclSpec::getSpecifierName(SCS);
}
if (DeclSpec::TSCS TSCS = DS.getThreadStorageClassSpec())
Diag(DS.getThreadStorageClassSpecLoc(), DiagID)
<< DeclSpec::getSpecifierName(TSCS);
if (DS.getTypeQualifiers()) {
if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
Diag(DS.getConstSpecLoc(), DiagID) << "const";
if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
Diag(DS.getConstSpecLoc(), DiagID) << "volatile";
// Restrict is covered above.
if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
Diag(DS.getAtomicSpecLoc(), DiagID) << "_Atomic";
if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
Diag(DS.getUnalignedSpecLoc(), DiagID) << "__unaligned";
}
// Warn about ignored type attributes, for example:
// __attribute__((aligned)) struct A;
// Attributes should be placed after tag to apply to type declaration.
if (!DS.getAttributes().empty() || !DeclAttrs.empty()) {
DeclSpec::TST TypeSpecType = DS.getTypeSpecType();
if (TypeSpecType == DeclSpec::TST_class ||
TypeSpecType == DeclSpec::TST_struct ||
TypeSpecType == DeclSpec::TST_interface ||
TypeSpecType == DeclSpec::TST_union ||
TypeSpecType == DeclSpec::TST_enum) {
auto EmitAttributeDiagnostic = [this, &DS](const ParsedAttr &AL) {
unsigned DiagnosticId = diag::warn_declspec_attribute_ignored;
if (AL.isAlignas() && !getLangOpts().CPlusPlus)
DiagnosticId = diag::warn_attribute_ignored;
else if (AL.isRegularKeywordAttribute())
DiagnosticId = diag::err_declspec_keyword_has_no_effect;
else
DiagnosticId = diag::warn_declspec_attribute_ignored;
Diag(AL.getLoc(), DiagnosticId)
<< AL << GetDiagnosticTypeSpecifierID(DS);
};
llvm::for_each(DS.getAttributes(), EmitAttributeDiagnostic);
llvm::for_each(DeclAttrs, EmitAttributeDiagnostic);
}
}
return TagD;
}
/// We are trying to inject an anonymous member into the given scope;
/// check if there's an existing declaration that can't be overloaded.
///
/// \return true if this is a forbidden redeclaration
static bool CheckAnonMemberRedeclaration(Sema &SemaRef, Scope *S,
DeclContext *Owner,
DeclarationName Name,
SourceLocation NameLoc, bool IsUnion,
StorageClass SC) {
LookupResult R(SemaRef, Name, NameLoc,
Owner->isRecord() ? Sema::LookupMemberName
: Sema::LookupOrdinaryName,
RedeclarationKind::ForVisibleRedeclaration);
if (!SemaRef.LookupName(R, S)) return false;
// Pick a representative declaration.
NamedDecl *PrevDecl = R.getRepresentativeDecl()->getUnderlyingDecl();
assert(PrevDecl && "Expected a non-null Decl");
if (!SemaRef.isDeclInScope(PrevDecl, Owner, S))
return false;
if (SC == StorageClass::SC_None &&
PrevDecl->isPlaceholderVar(SemaRef.getLangOpts()) &&
(Owner->isFunctionOrMethod() || Owner->isRecord())) {
if (!Owner->isRecord())
SemaRef.DiagPlaceholderVariableDefinition(NameLoc);
return false;
}
SemaRef.Diag(NameLoc, diag::err_anonymous_record_member_redecl)
<< IsUnion << Name;
SemaRef.Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
return true;
}
void Sema::ActOnDefinedDeclarationSpecifier(Decl *D) {
if (auto *RD = dyn_cast_if_present<RecordDecl>(D))
DiagPlaceholderFieldDeclDefinitions(RD);
}
void Sema::DiagPlaceholderFieldDeclDefinitions(RecordDecl *Record) {
if (!getLangOpts().CPlusPlus)
return;
// This function can be parsed before we have validated the
// structure as an anonymous struct
if (Record->isAnonymousStructOrUnion())
return;
const NamedDecl *First = 0;
for (const Decl *D : Record->decls()) {
const NamedDecl *ND = dyn_cast<NamedDecl>(D);
if (!ND || !ND->isPlaceholderVar(getLangOpts()))
continue;
if (!First)
First = ND;
else
DiagPlaceholderVariableDefinition(ND->getLocation());
}
}
/// InjectAnonymousStructOrUnionMembers - Inject the members of the
/// anonymous struct or union AnonRecord into the owning context Owner
/// and scope S. This routine will be invoked just after we realize
/// that an unnamed union or struct is actually an anonymous union or
/// struct, e.g.,
///
/// @code
/// union {
/// int i;
/// float f;
/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and
/// // f into the surrounding scope.x
/// @endcode
///
/// This routine is recursive, injecting the names of nested anonymous
/// structs/unions into the owning context and scope as well.
static bool
InjectAnonymousStructOrUnionMembers(Sema &SemaRef, Scope *S, DeclContext *Owner,
RecordDecl *AnonRecord, AccessSpecifier AS,
StorageClass SC,
SmallVectorImpl<NamedDecl *> &Chaining) {
bool Invalid = false;
// Look every FieldDecl and IndirectFieldDecl with a name.
for (auto *D : AnonRecord->decls()) {
if ((isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D)) &&
cast<NamedDecl>(D)->getDeclName()) {
ValueDecl *VD = cast<ValueDecl>(D);
// C++ [class.union]p2:
// The names of the members of an anonymous union shall be
// distinct from the names of any other entity in the
// scope in which the anonymous union is declared.
bool FieldInvalid = CheckAnonMemberRedeclaration(
SemaRef, S, Owner, VD->getDeclName(), VD->getLocation(),
AnonRecord->isUnion(), SC);
if (FieldInvalid)
Invalid = true;
// Inject the IndirectFieldDecl even if invalid, because later
// diagnostics may depend on it being present, see findDefaultInitializer.
// C++ [class.union]p2:
// For the purpose of name lookup, after the anonymous union
// definition, the members of the anonymous union are
// considered to have been defined in the scope in which the
// anonymous union is declared.
unsigned OldChainingSize = Chaining.size();
if (IndirectFieldDecl *IF = dyn_cast<IndirectFieldDecl>(VD))
Chaining.append(IF->chain_begin(), IF->chain_end());
else
Chaining.push_back(VD);
assert(Chaining.size() >= 2);
NamedDecl **NamedChain =
new (SemaRef.Context) NamedDecl *[Chaining.size()];
for (unsigned i = 0; i < Chaining.size(); i++)
NamedChain[i] = Chaining[i];
IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
SemaRef.Context, Owner, VD->getLocation(), VD->getIdentifier(),
VD->getType(), {NamedChain, Chaining.size()});
for (const auto *Attr : VD->attrs())
IndirectField->addAttr(Attr->clone(SemaRef.Context));
IndirectField->setAccess(AS);
IndirectField->setImplicit();
IndirectField->setInvalidDecl(FieldInvalid);
SemaRef.PushOnScopeChains(IndirectField, S);
// That includes picking up the appropriate access specifier.
if (AS != AS_none)
IndirectField->setAccess(AS);
Chaining.resize(OldChainingSize);
}
}
return Invalid;
}
/// StorageClassSpecToVarDeclStorageClass - Maps a DeclSpec::SCS to
/// a VarDecl::StorageClass. Any error reporting is up to the caller:
/// illegal input values are mapped to SC_None.
static StorageClass
StorageClassSpecToVarDeclStorageClass(const DeclSpec &DS) {
DeclSpec::SCS StorageClassSpec = DS.getStorageClassSpec();
assert(StorageClassSpec != DeclSpec::SCS_typedef &&
"Parser allowed 'typedef' as storage class VarDecl.");
switch (StorageClassSpec) {
case DeclSpec::SCS_unspecified: return SC_None;
case DeclSpec::SCS_extern:
if (DS.isExternInLinkageSpec())
return SC_None;
return SC_Extern;
case DeclSpec::SCS_static: return SC_Static;
case DeclSpec::SCS_auto: return SC_Auto;
case DeclSpec::SCS_register: return SC_Register;
case DeclSpec::SCS_private_extern: return SC_PrivateExtern;
// Illegal SCSs map to None: error reporting is up to the caller.
case DeclSpec::SCS_mutable: // Fall through.
case DeclSpec::SCS_typedef: return SC_None;
}
llvm_unreachable("unknown storage class specifier");
}
static SourceLocation findDefaultInitializer(const CXXRecordDecl *Record) {
assert(Record->hasInClassInitializer());
for (const auto *I : Record->decls()) {
const auto *FD = dyn_cast<FieldDecl>(I);
if (const auto *IFD = dyn_cast<IndirectFieldDecl>(I))
FD = IFD->getAnonField();
if (FD && FD->hasInClassInitializer())
return FD->getLocation();
}
llvm_unreachable("couldn't find in-class initializer");
}
static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent,
SourceLocation DefaultInitLoc) {
if (!Parent->isUnion() || !Parent->hasInClassInitializer())
return;
S.Diag(DefaultInitLoc, diag::err_multiple_mem_union_initialization);
S.Diag(findDefaultInitializer(Parent), diag::note_previous_initializer) << 0;
}
static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent,
CXXRecordDecl *AnonUnion) {
if (!Parent->isUnion() || !Parent->hasInClassInitializer())
return;
checkDuplicateDefaultInit(S, Parent, findDefaultInitializer(AnonUnion));
}
Decl *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
AccessSpecifier AS,
RecordDecl *Record,
const PrintingPolicy &Policy) {
DeclContext *Owner = Record->getDeclContext();
// Diagnose whether this anonymous struct/union is an extension.
if (Record->isUnion() && !getLangOpts().CPlusPlus && !getLangOpts().C11)
Diag(Record->getLocation(), diag::ext_anonymous_union);
else if (!Record->isUnion() && getLangOpts().CPlusPlus)
Diag(Record->getLocation(), diag::ext_gnu_anonymous_struct);
else if (!Record->isUnion() && !getLangOpts().C11)
Diag(Record->getLocation(), diag::ext_c11_anonymous_struct);
// C and C++ require different kinds of checks for anonymous
// structs/unions.
bool Invalid = false;
if (getLangOpts().CPlusPlus) {
const char *PrevSpec = nullptr;
if (Record->isUnion()) {
// C++ [class.union]p6:
// C++17 [class.union.anon]p2:
// Anonymous unions declared in a named namespace or in the
// global namespace shall be declared static.
unsigned DiagID;
DeclContext *OwnerScope = Owner->getRedeclContext();
if (DS.getStorageClassSpec() != DeclSpec::SCS_static &&
(OwnerScope->isTranslationUnit() ||
(OwnerScope->isNamespace() &&
!cast<NamespaceDecl>(OwnerScope)->isAnonymousNamespace()))) {
Diag(Record->getLocation(), diag::err_anonymous_union_not_static)
<< FixItHint::CreateInsertion(Record->getLocation(), "static ");
// Recover by adding 'static'.
DS.SetStorageClassSpec(*this, DeclSpec::SCS_static, SourceLocation(),
PrevSpec, DiagID, Policy);
}
// C++ [class.union]p6:
// A storage class is not allowed in a declaration of an
// anonymous union in a class scope.
else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
isa<RecordDecl>(Owner)) {
Diag(DS.getStorageClassSpecLoc(),
diag::err_anonymous_union_with_storage_spec)
<< FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
// Recover by removing the storage specifier.
DS.SetStorageClassSpec(*this, DeclSpec::SCS_unspecified,
SourceLocation(),
PrevSpec, DiagID, Context.getPrintingPolicy());
}
}
// Ignore const/volatile/restrict qualifiers.
if (DS.getTypeQualifiers()) {
if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
Diag(DS.getConstSpecLoc(), diag::ext_anonymous_struct_union_qualified)
<< Record->isUnion() << "const"
<< FixItHint::CreateRemoval(DS.getConstSpecLoc());
if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
Diag(DS.getVolatileSpecLoc(),
diag::ext_anonymous_struct_union_qualified)
<< Record->isUnion() << "volatile"
<< FixItHint::CreateRemoval(DS.getVolatileSpecLoc());
if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
Diag(DS.getRestrictSpecLoc(),
diag::ext_anonymous_struct_union_qualified)
<< Record->isUnion() << "restrict"
<< FixItHint::CreateRemoval(DS.getRestrictSpecLoc());
if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
Diag(DS.getAtomicSpecLoc(),
diag::ext_anonymous_struct_union_qualified)
<< Record->isUnion() << "_Atomic"
<< FixItHint::CreateRemoval(DS.getAtomicSpecLoc());
if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
Diag(DS.getUnalignedSpecLoc(),
diag::ext_anonymous_struct_union_qualified)
<< Record->isUnion() << "__unaligned"
<< FixItHint::CreateRemoval(DS.getUnalignedSpecLoc());
DS.ClearTypeQualifiers();
}
// C++ [class.union]p2:
// The member-specification of an anonymous union shall only
// define non-static data members. [Note: nested types and
// functions cannot be declared within an anonymous union. ]
for (auto *Mem : Record->decls()) {
// Ignore invalid declarations; we already diagnosed them.
if (Mem->isInvalidDecl())
continue;
if (auto *FD = dyn_cast<FieldDecl>(Mem)) {
// C++ [class.union]p3:
// An anonymous union shall not have private or protected
// members (clause 11).
assert(FD->getAccess() != AS_none);
if (FD->getAccess() != AS_public) {
Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member)
<< Record->isUnion() << (FD->getAccess() == AS_protected);
Invalid = true;
}
// C++ [class.union]p1
// An object of a class with a non-trivial constructor, a non-trivial
// copy constructor, a non-trivial destructor, or a non-trivial copy
// assignment operator cannot be a member of a union, nor can an
// array of such objects.
if (CheckNontrivialField(FD))
Invalid = true;
} else if (Mem->isImplicit()) {
// Any implicit members are fine.
} else if (isa<TagDecl>(Mem) && Mem->getDeclContext() != Record) {
// This is a type that showed up in an
// elaborated-type-specifier inside the anonymous struct or
// union, but which actually declares a type outside of the
// anonymous struct or union. It's okay.
} else if (auto *MemRecord = dyn_cast<RecordDecl>(Mem)) {
if (!MemRecord->isAnonymousStructOrUnion() &&
MemRecord->getDeclName()) {
// Visual C++ allows type definition in anonymous struct or union.
if (getLangOpts().MicrosoftExt)
Diag(MemRecord->getLocation(), diag::ext_anonymous_record_with_type)
<< Record->isUnion();
else {
// This is a nested type declaration.
Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type)
<< Record->isUnion();
Invalid = true;
}
} else {
// This is an anonymous type definition within another anonymous type.
// This is a popular extension, provided by Plan9, MSVC and GCC, but
// not part of standard C++.
Diag(MemRecord->getLocation(),
diag::ext_anonymous_record_with_anonymous_type)
<< Record->isUnion();
}
} else if (isa<AccessSpecDecl>(Mem)) {
// Any access specifier is fine.
} else if (isa<StaticAssertDecl>(Mem)) {
// In C++1z, static_assert declarations are also fine.
} else {
// We have something that isn't a non-static data
// member. Complain about it.
unsigned DK = diag::err_anonymous_record_bad_member;
if (isa<TypeDecl>(Mem))
DK = diag::err_anonymous_record_with_type;
else if (isa<FunctionDecl>(Mem))
DK = diag::err_anonymous_record_with_function;
else if (isa<VarDecl>(Mem))
DK = diag::err_anonymous_record_with_static;
// Visual C++ allows type definition in anonymous struct or union.
if (getLangOpts().MicrosoftExt &&
DK == diag::err_anonymous_record_with_type)
Diag(Mem->getLocation(), diag::ext_anonymous_record_with_type)
<< Record->isUnion();
else {
Diag(Mem->getLocation(), DK) << Record->isUnion();
Invalid = true;
}
}
}
// C++11 [class.union]p8 (DR1460):
// At most one variant member of a union may have a
// brace-or-equal-initializer.
if (cast<CXXRecordDecl>(Record)->hasInClassInitializer() &&
Owner->isRecord())
checkDuplicateDefaultInit(*this, cast<CXXRecordDecl>(Owner),
cast<CXXRecordDecl>(Record));
}
if (!Record->isUnion() && !Owner->isRecord()) {
Diag(Record->getLocation(), diag::err_anonymous_struct_not_member)
<< getLangOpts().CPlusPlus;
Invalid = true;
}
// C++ [dcl.dcl]p3:
// [If there are no declarators], and except for the declaration of an
// unnamed bit-field, the decl-specifier-seq shall introduce one or more
// names into the program
// C++ [class.mem]p2:
// each such member-declaration shall either declare at least one member
// name of the class or declare at least one unnamed bit-field
//
// For C this is an error even for a named struct, and is diagnosed elsewhere.
if (getLangOpts().CPlusPlus && Record->field_empty())
Diag(DS.getBeginLoc(), diag::ext_no_declarators) << DS.getSourceRange();
// Mock up a declarator.
Declarator Dc(DS, ParsedAttributesView::none(), DeclaratorContext::Member);
StorageClass SC = StorageClassSpecToVarDeclStorageClass(DS);
TypeSourceInfo *TInfo = GetTypeForDeclarator(Dc);
assert(TInfo && "couldn't build declarator info for anonymous struct/union");
// Create a declaration for this anonymous struct/union.
NamedDecl *Anon = nullptr;
if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) {
Anon = FieldDecl::Create(
Context, OwningClass, DS.getBeginLoc(), Record->getLocation(),
/*IdentifierInfo=*/nullptr, Context.getCanonicalTagType(Record), TInfo,
/*BitWidth=*/nullptr, /*Mutable=*/false,
/*InitStyle=*/ICIS_NoInit);
Anon->setAccess(AS);
ProcessDeclAttributes(S, Anon, Dc);
if (getLangOpts().CPlusPlus)
FieldCollector->Add(cast<FieldDecl>(Anon));
} else {
DeclSpec::SCS SCSpec = DS.getStorageClassSpec();
if (SCSpec == DeclSpec::SCS_mutable) {
// mutable can only appear on non-static class members, so it's always
// an error here
Diag(Record->getLocation(), diag::err_mutable_nonmember);
Invalid = true;
SC = SC_None;
}
Anon = VarDecl::Create(Context, Owner, DS.getBeginLoc(),
Record->getLocation(), /*IdentifierInfo=*/nullptr,
Context.getCanonicalTagType(Record), TInfo, SC);
if (Invalid)
Anon->setInvalidDecl();
ProcessDeclAttributes(S, Anon, Dc);
// Default-initialize the implicit variable. This initialization will be
// trivial in almost all cases, except if a union member has an in-class
// initializer:
// union { int n = 0; };
ActOnUninitializedDecl(Anon);
}
Anon->setImplicit();
// Mark this as an anonymous struct/union type.
Record->setAnonymousStructOrUnion(true);
// Add the anonymous struct/union object to the current
// context. We'll be referencing this object when we refer to one of
// its members.
Owner->addDecl(Anon);
// Inject the members of the anonymous struct/union into the owning
// context and into the identifier resolver chain for name lookup
// purposes.
SmallVector<NamedDecl*, 2> Chain;
Chain.push_back(Anon);
if (InjectAnonymousStructOrUnionMembers(*this, S, Owner, Record, AS, SC,
Chain))
Invalid = true;
if (VarDecl *NewVD = dyn_cast<VarDecl>(Anon)) {
if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
MangleNumberingContext *MCtx;
Decl *ManglingContextDecl;
std::tie(MCtx, ManglingContextDecl) =
getCurrentMangleNumberContext(NewVD->getDeclContext());
if (MCtx) {
Context.setManglingNumber(
NewVD, MCtx->getManglingNumber(
NewVD, getMSManglingNumber(getLangOpts(), S)));
Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD));
}
}
}
if (Invalid)
Anon->setInvalidDecl();
return Anon;
}
Decl *Sema::BuildMicrosoftCAnonymousStruct(Scope *S, DeclSpec &DS,
RecordDecl *Record) {
assert(Record && "expected a record!");
// Mock up a declarator.
Declarator Dc(DS, ParsedAttributesView::none(), DeclaratorContext::TypeName);
TypeSourceInfo *TInfo = GetTypeForDeclarator(Dc);
assert(TInfo && "couldn't build declarator info for anonymous struct");
auto *ParentDecl = cast<RecordDecl>(CurContext);
CanQualType RecTy = Context.getCanonicalTagType(Record);
// Create a declaration for this anonymous struct.
NamedDecl *Anon =
FieldDecl::Create(Context, ParentDecl, DS.getBeginLoc(), DS.getBeginLoc(),
/*IdentifierInfo=*/nullptr, RecTy, TInfo,
/*BitWidth=*/nullptr, /*Mutable=*/false,
/*InitStyle=*/ICIS_NoInit);
Anon->setImplicit();
// Add the anonymous struct object to the current context.
CurContext->addDecl(Anon);
// Inject the members of the anonymous struct into the current
// context and into the identifier resolver chain for name lookup
// purposes.
SmallVector<NamedDecl*, 2> Chain;
Chain.push_back(Anon);
RecordDecl *RecordDef = Record->getDefinition();
if (RequireCompleteSizedType(Anon->getLocation(), RecTy,
diag::err_field_incomplete_or_sizeless) ||
InjectAnonymousStructOrUnionMembers(
*this, S, CurContext, RecordDef, AS_none,
StorageClassSpecToVarDeclStorageClass(DS), Chain)) {
Anon->setInvalidDecl();
ParentDecl->setInvalidDecl();
}
return Anon;
}
DeclarationNameInfo Sema::GetNameForDeclarator(Declarator &D) {
return GetNameFromUnqualifiedId(D.getName());
}
DeclarationNameInfo
Sema::GetNameFromUnqualifiedId(const UnqualifiedId &Name) {
DeclarationNameInfo NameInfo;
NameInfo.setLoc(Name.StartLocation);
switch (Name.getKind()) {
case UnqualifiedIdKind::IK_ImplicitSelfParam:
case UnqualifiedIdKind::IK_Identifier:
NameInfo.setName(Name.Identifier);
return NameInfo;
case UnqualifiedIdKind::IK_DeductionGuideName: {
// C++ [temp.deduct.guide]p3:
// The simple-template-id shall name a class template specialization.
// The template-name shall be the same identifier as the template-name
// of the simple-template-id.
// These together intend to imply that the template-name shall name a
// class template.
// FIXME: template<typename T> struct X {};
// template<typename T> using Y = X<T>;
// Y(int) -> Y<int>;
// satisfies these rules but does not name a class template.
TemplateName TN = Name.TemplateName.get().get();
auto *Template = TN.getAsTemplateDecl();
if (!Template || !isa<ClassTemplateDecl>(Template)) {
Diag(Name.StartLocation,
diag::err_deduction_guide_name_not_class_template)
<< (int)getTemplateNameKindForDiagnostics(TN) << TN;
if (Template)
NoteTemplateLocation(*Template);
return DeclarationNameInfo();
}
NameInfo.setName(
Context.DeclarationNames.getCXXDeductionGuideName(Template));
return NameInfo;
}
case UnqualifiedIdKind::IK_OperatorFunctionId:
NameInfo.setName(Context.DeclarationNames.getCXXOperatorName(
Name.OperatorFunctionId.Operator));
NameInfo.setCXXOperatorNameRange(SourceRange(
Name.OperatorFunctionId.SymbolLocations[0], Name.EndLocation));
return NameInfo;
case UnqualifiedIdKind::IK_LiteralOperatorId:
NameInfo.setName(Context.DeclarationNames.getCXXLiteralOperatorName(
Name.Identifier));
NameInfo.setCXXLiteralOperatorNameLoc(Name.EndLocation);
return NameInfo;
case UnqualifiedIdKind::IK_ConversionFunctionId: {
TypeSourceInfo *TInfo;
QualType Ty = GetTypeFromParser(Name.ConversionFunctionId, &TInfo);
if (Ty.isNull())
return DeclarationNameInfo();
NameInfo.setName(Context.DeclarationNames.getCXXConversionFunctionName(
Context.getCanonicalType(Ty)));
NameInfo.setNamedTypeInfo(TInfo);
return NameInfo;
}
case UnqualifiedIdKind::IK_ConstructorName: {
TypeSourceInfo *TInfo;
QualType Ty = GetTypeFromParser(Name.ConstructorName, &TInfo);
if (Ty.isNull())
return DeclarationNameInfo();
NameInfo.setName(Context.DeclarationNames.getCXXConstructorName(
Context.getCanonicalType(Ty)));
NameInfo.setNamedTypeInfo(TInfo);
return NameInfo;
}
case UnqualifiedIdKind::IK_ConstructorTemplateId: {
// In well-formed code, we can only have a constructor
// template-id that refers to the current context, so go there
// to find the actual type being constructed.
CXXRecordDecl *CurClass = dyn_cast<CXXRecordDecl>(CurContext);
if (!CurClass || CurClass->getIdentifier() != Name.TemplateId->Name)
return DeclarationNameInfo();
// Determine the type of the class being constructed.
CanQualType CurClassType = Context.getCanonicalTagType(CurClass);
// FIXME: Check two things: that the template-id names the same type as
// CurClassType, and that the template-id does not occur when the name
// was qualified.
NameInfo.setName(
Context.DeclarationNames.getCXXConstructorName(CurClassType));
// FIXME: should we retrieve TypeSourceInfo?
NameInfo.setNamedTypeInfo(nullptr);
return NameInfo;
}
case UnqualifiedIdKind::IK_DestructorName: {
TypeSourceInfo *TInfo;
QualType Ty = GetTypeFromParser(Name.DestructorName, &TInfo);
if (Ty.isNull())
return DeclarationNameInfo();
NameInfo.setName(Context.DeclarationNames.getCXXDestructorName(
Context.getCanonicalType(Ty)));
NameInfo.setNamedTypeInfo(TInfo);
return NameInfo;
}
case UnqualifiedIdKind::IK_TemplateId: {
TemplateName TName = Name.TemplateId->Template.get();
SourceLocation TNameLoc = Name.TemplateId->TemplateNameLoc;
return Context.getNameForTemplate(TName, TNameLoc);
}
} // switch (Name.getKind())
llvm_unreachable("Unknown name kind");
}
static QualType getCoreType(QualType Ty) {
do {
if (Ty->isPointerOrReferenceType())
Ty = Ty->getPointeeType();
else if (Ty->isArrayType())
Ty = Ty->castAsArrayTypeUnsafe()->getElementType();
else
return Ty.withoutLocalFastQualifiers();
} while (true);
}
/// hasSimilarParameters - Determine whether the C++ functions Declaration
/// and Definition have "nearly" matching parameters. This heuristic is
/// used to improve diagnostics in the case where an out-of-line function
/// definition doesn't match any declaration within the class or namespace.
/// Also sets Params to the list of indices to the parameters that differ
/// between the declaration and the definition. If hasSimilarParameters
/// returns true and Params is empty, then all of the parameters match.
static bool hasSimilarParameters(ASTContext &Context,
FunctionDecl *Declaration,
FunctionDecl *Definition,
SmallVectorImpl<unsigned> &Params) {
Params.clear();
if (Declaration->param_size() != Definition->param_size())
return false;
for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) {
QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType();
QualType DefParamTy = Definition->getParamDecl(Idx)->getType();
// The parameter types are identical
if (Context.hasSameUnqualifiedType(DefParamTy, DeclParamTy))
continue;
QualType DeclParamBaseTy = getCoreType(DeclParamTy);
QualType DefParamBaseTy = getCoreType(DefParamTy);
const IdentifierInfo *DeclTyName = DeclParamBaseTy.getBaseTypeIdentifier();
const IdentifierInfo *DefTyName = DefParamBaseTy.getBaseTypeIdentifier();
if (Context.hasSameUnqualifiedType(DeclParamBaseTy, DefParamBaseTy) ||
(DeclTyName && DeclTyName == DefTyName))
Params.push_back(Idx);
else // The two parameters aren't even close
return false;
}
return true;
}
/// RebuildDeclaratorInCurrentInstantiation - Checks whether the given
/// declarator needs to be rebuilt in the current instantiation.
/// Any bits of declarator which appear before the name are valid for
/// consideration here. That's specifically the type in the decl spec
/// and the base type in any member-pointer chunks.
static bool RebuildDeclaratorInCurrentInstantiation(Sema &S, Declarator &D,
DeclarationName Name) {
// The types we specifically need to rebuild are:
// - typenames, typeofs, and decltypes
// - types which will become injected class names
// Of course, we also need to rebuild any type referencing such a
// type. It's safest to just say "dependent", but we call out a
// few cases here.
DeclSpec &DS = D.getMutableDeclSpec();
switch (DS.getTypeSpecType()) {
case DeclSpec::TST_typename:
case DeclSpec::TST_typeofType:
case DeclSpec::TST_typeof_unqualType:
#define TRANSFORM_TYPE_TRAIT_DEF(_, Trait) case DeclSpec::TST_##Trait:
#include "clang/Basic/TransformTypeTraits.def"
case DeclSpec::TST_atomic: {
// Grab the type from the parser.
TypeSourceInfo *TSI = nullptr;
QualType T = S.GetTypeFromParser(DS.getRepAsType(), &TSI);
if (T.isNull() || !T->isInstantiationDependentType()) break;
// Make sure there's a type source info. This isn't really much
// of a waste; most dependent types should have type source info
// attached already.
if (!TSI)
TSI = S.Context.getTrivialTypeSourceInfo(T, DS.getTypeSpecTypeLoc());
// Rebuild the type in the current instantiation.
TSI = S.RebuildTypeInCurrentInstantiation(TSI, D.getIdentifierLoc(), Name);
if (!TSI) return true;
// Store the new type back in the decl spec.
ParsedType LocType = S.CreateParsedType(TSI->getType(), TSI);
DS.UpdateTypeRep(LocType);
break;
}
case DeclSpec::TST_decltype:
case DeclSpec::TST_typeof_unqualExpr:
case DeclSpec::TST_typeofExpr: {
Expr *E = DS.getRepAsExpr();
ExprResult Result = S.RebuildExprInCurrentInstantiation(E);
if (Result.isInvalid()) return true;
DS.UpdateExprRep(Result.get());
break;
}
default:
// Nothing to do for these decl specs.
break;
}
// It doesn't matter what order we do this in.
for (unsigned I = 0, E = D.getNumTypeObjects(); I != E; ++I) {
DeclaratorChunk &Chunk = D.getTypeObject(I);
// The only type information in the declarator which can come
// before the declaration name is the base type of a member
// pointer.
if (Chunk.Kind != DeclaratorChunk::MemberPointer)
continue;
// Rebuild the scope specifier in-place.
CXXScopeSpec &SS = Chunk.Mem.Scope();
if (S.RebuildNestedNameSpecifierInCurrentInstantiation(SS))
return true;
}
return false;
}
/// Returns true if the declaration is declared in a system header or from a
/// system macro.
static bool isFromSystemHeader(SourceManager &SM, const Decl *D) {
return SM.isInSystemHeader(D->getLocation()) ||
SM.isInSystemMacro(D->getLocation());
}
void Sema::warnOnReservedIdentifier(const NamedDecl *D) {
// Avoid warning twice on the same identifier, and don't warn on redeclaration
// of system decl.
if (D->getPreviousDecl() || D->isImplicit())
return;
ReservedIdentifierStatus Status = D->isReserved(getLangOpts());
if (Status != ReservedIdentifierStatus::NotReserved &&
!isFromSystemHeader(Context.getSourceManager(), D)) {
Diag(D->getLocation(), diag::warn_reserved_extern_symbol)
<< D << static_cast<int>(Status);
}
}
Decl *Sema::ActOnDeclarator(Scope *S, Declarator &D) {
D.setFunctionDefinitionKind(FunctionDefinitionKind::Declaration);
// Check if we are in an `omp begin/end declare variant` scope. Handle this
// declaration only if the `bind_to_declaration` extension is set.
SmallVector<FunctionDecl *, 4> Bases;
if (LangOpts.OpenMP && OpenMP().isInOpenMPDeclareVariantScope())
if (OpenMP().getOMPTraitInfoForSurroundingScope()->isExtensionActive(
llvm::omp::TraitProperty::
implementation_extension_bind_to_declaration))
OpenMP().ActOnStartOfFunctionDefinitionInOpenMPDeclareVariantScope(
S, D, MultiTemplateParamsArg(), Bases);
Decl *Dcl = HandleDeclarator(S, D, MultiTemplateParamsArg());
if (OriginalLexicalContext && OriginalLexicalContext->isObjCContainer() &&
Dcl && Dcl->getDeclContext()->isFileContext())
Dcl->setTopLevelDeclInObjCContainer();
if (!Bases.empty())
OpenMP().ActOnFinishedFunctionDefinitionInOpenMPDeclareVariantScope(Dcl,
Bases);
return Dcl;
}
bool Sema::DiagnoseClassNameShadow(DeclContext *DC,
DeclarationNameInfo NameInfo) {
DeclarationName Name = NameInfo.getName();
CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC);
while (Record && Record->isAnonymousStructOrUnion())
Record = dyn_cast<CXXRecordDecl>(Record->getParent());
if (Record && Record->getIdentifier() && Record->getDeclName() == Name) {
Diag(NameInfo.getLoc(), diag::err_member_name_of_class) << Name;
return true;
}
return false;
}
bool Sema::diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
DeclarationName Name,
SourceLocation Loc,
TemplateIdAnnotation *TemplateId,
bool IsMemberSpecialization) {
assert(SS.isValid() && "diagnoseQualifiedDeclaration called for declaration "
"without nested-name-specifier");
DeclContext *Cur = CurContext;
while (isa<LinkageSpecDecl>(Cur) || isa<CapturedDecl>(Cur))
Cur = Cur->getParent();
// If the user provided a superfluous scope specifier that refers back to the
// class in which the entity is already declared, diagnose and ignore it.
//
// class X {
// void X::f();
// };
//
// Note, it was once ill-formed to give redundant qualification in all
// contexts, but that rule was removed by DR482.
if (Cur->Equals(DC)) {
if (Cur->isRecord()) {
Diag(Loc, LangOpts.MicrosoftExt ? diag::warn_member_extra_qualification
: diag::err_member_extra_qualification)
<< Name << FixItHint::CreateRemoval(SS.getRange());
SS.clear();
} else {
Diag(Loc, diag::warn_namespace_member_extra_qualification) << Name;
}
return false;
}
// Check whether the qualifying scope encloses the scope of the original
// declaration. For a template-id, we perform the checks in
// CheckTemplateSpecializationScope.
if (!Cur->Encloses(DC) && !(TemplateId || IsMemberSpecialization)) {
if (Cur->isRecord())
Diag(Loc, diag::err_member_qualification)
<< Name << SS.getRange();
else if (isa<TranslationUnitDecl>(DC))
Diag(Loc, diag::err_invalid_declarator_global_scope)
<< Name << SS.getRange();
else if (isa<FunctionDecl>(Cur))
Diag(Loc, diag::err_invalid_declarator_in_function)
<< Name << SS.getRange();
else if (isa<BlockDecl>(Cur))
Diag(Loc, diag::err_invalid_declarator_in_block)
<< Name << SS.getRange();
else if (isa<ExportDecl>(Cur)) {
if (!isa<NamespaceDecl>(DC))
Diag(Loc, diag::err_export_non_namespace_scope_name)
<< Name << SS.getRange();
else
// The cases that DC is not NamespaceDecl should be handled in
// CheckRedeclarationExported.
return false;
} else
Diag(Loc, diag::err_invalid_declarator_scope)
<< Name << cast<NamedDecl>(Cur) << cast<NamedDecl>(DC) << SS.getRange();
return true;
}
if (Cur->isRecord()) {
// Cannot qualify members within a class.
Diag(Loc, diag::err_member_qualification)
<< Name << SS.getRange();
SS.clear();
// C++ constructors and destructors with incorrect scopes can break
// our AST invariants by having the wrong underlying types. If
// that's the case, then drop this declaration entirely.
if ((Name.getNameKind() == DeclarationName::CXXConstructorName ||
Name.getNameKind() == DeclarationName::CXXDestructorName) &&
!Context.hasSameType(
Name.getCXXNameType(),
Context.getCanonicalTagType(cast<CXXRecordDecl>(Cur))))
return true;
return false;
}
// C++23 [temp.names]p5:
// The keyword template shall not appear immediately after a declarative
// nested-name-specifier.
//
// First check the template-id (if any), and then check each component of the
// nested-name-specifier in reverse order.
//
// FIXME: nested-name-specifiers in friend declarations are declarative,
// but we don't call diagnoseQualifiedDeclaration for them. We should.
if (TemplateId && TemplateId->TemplateKWLoc.isValid())
Diag(Loc, diag::ext_template_after_declarative_nns)
<< FixItHint::CreateRemoval(TemplateId->TemplateKWLoc);
NestedNameSpecifierLoc SpecLoc(SS.getScopeRep(), SS.location_data());
for (TypeLoc TL = SpecLoc.getAsTypeLoc(), NextTL; TL;
TL = std::exchange(NextTL, TypeLoc())) {
SourceLocation TemplateKeywordLoc;
switch (TL.getTypeLocClass()) {
case TypeLoc::TemplateSpecialization: {
auto TST = TL.castAs<TemplateSpecializationTypeLoc>();
TemplateKeywordLoc = TST.getTemplateKeywordLoc();
if (auto *T = TST.getTypePtr(); T->isDependentType() && T->isTypeAlias())
Diag(Loc, diag::ext_alias_template_in_declarative_nns)
<< TST.getLocalSourceRange();
break;
}
case TypeLoc::Decltype:
case TypeLoc::PackIndexing: {
const Type *T = TL.getTypePtr();
// C++23 [expr.prim.id.qual]p2:
// [...] A declarative nested-name-specifier shall not have a
// computed-type-specifier.
//
// CWG2858 changed this from 'decltype-specifier' to
// 'computed-type-specifier'.
Diag(Loc, diag::err_computed_type_in_declarative_nns)
<< T->isDecltypeType() << TL.getSourceRange();
break;
}
case TypeLoc::DependentName:
NextTL =
TL.castAs<DependentNameTypeLoc>().getQualifierLoc().getAsTypeLoc();
break;
case TypeLoc::DependentTemplateSpecialization: {
auto TST = TL.castAs<DependentTemplateSpecializationTypeLoc>();
TemplateKeywordLoc = TST.getTemplateKeywordLoc();
NextTL = TST.getQualifierLoc().getAsTypeLoc();
break;
}
default:
break;
}
if (TemplateKeywordLoc.isValid())
Diag(Loc, diag::ext_template_after_declarative_nns)
<< FixItHint::CreateRemoval(TemplateKeywordLoc);
}
return false;
}
NamedDecl *Sema::HandleDeclarator(Scope *S, Declarator &D,
MultiTemplateParamsArg TemplateParamLists) {
// TODO: consider using NameInfo for diagnostic.
DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
DeclarationName Name = NameInfo.getName();
// All of these full declarators require an identifier. If it doesn't have
// one, the ParsedFreeStandingDeclSpec action should be used.
if (D.isDecompositionDeclarator()) {
return ActOnDecompositionDeclarator(S, D, TemplateParamLists);
} else if (!Name) {
if (!D.isInvalidType()) // Reject this if we think it is valid.
Diag(D.getDeclSpec().getBeginLoc(), diag::err_declarator_need_ident)
<< D.getDeclSpec().getSourceRange() << D.getSourceRange();
return nullptr;
} else if (DiagnoseUnexpandedParameterPack(NameInfo, UPPC_DeclarationType))
return nullptr;
DeclContext *DC = CurContext;
if (D.getCXXScopeSpec().isInvalid())
D.setInvalidType();
else if (D.getCXXScopeSpec().isSet()) {
if (DiagnoseUnexpandedParameterPack(D.getCXXScopeSpec(),
UPPC_DeclarationQualifier))
return nullptr;
bool EnteringContext = !D.getDeclSpec().isFriendSpecified();
DC = computeDeclContext(D.getCXXScopeSpec(), EnteringContext);
if (!DC || isa<EnumDecl>(DC)) {
// If we could not compute the declaration context, it's because the
// declaration context is dependent but does not refer to a class,
// class template, or class template partial specialization. Complain
// and return early, to avoid the coming semantic disaster.
Diag(D.getIdentifierLoc(),
diag::err_template_qualified_declarator_no_match)
<< D.getCXXScopeSpec().getScopeRep()
<< D.getCXXScopeSpec().getRange();
return nullptr;
}
bool IsDependentContext = DC->isDependentContext();
if (!IsDependentContext &&
RequireCompleteDeclContext(D.getCXXScopeSpec(), DC))
return nullptr;
// If a class is incomplete, do not parse entities inside it.
if (isa<CXXRecordDecl>(DC) && !cast<CXXRecordDecl>(DC)->hasDefinition()) {
Diag(D.getIdentifierLoc(),
diag::err_member_def_undefined_record)
<< Name << DC << D.getCXXScopeSpec().getRange();
return nullptr;
}
if (!D.getDeclSpec().isFriendSpecified()) {
TemplateIdAnnotation *TemplateId =
D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
? D.getName().TemplateId
: nullptr;
if (diagnoseQualifiedDeclaration(D.getCXXScopeSpec(), DC, Name,
D.getIdentifierLoc(), TemplateId,
/*IsMemberSpecialization=*/false)) {
if (DC->isRecord())
return nullptr;
D.setInvalidType();
}
}
// Check whether we need to rebuild the type of the given
// declaration in the current instantiation.
if (EnteringContext && IsDependentContext &&
TemplateParamLists.size() != 0) {
ContextRAII SavedContext(*this, DC);
if (RebuildDeclaratorInCurrentInstantiation(*this, D, Name))
D.setInvalidType();
}
}
TypeSourceInfo *TInfo = GetTypeForDeclarator(D);
QualType R = TInfo->getType();
if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
UPPC_DeclarationType))
D.setInvalidType();
LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
forRedeclarationInCurContext());
// See if this is a redefinition of a variable in the same scope.
if (!D.getCXXScopeSpec().isSet()) {
bool IsLinkageLookup = false;
bool CreateBuiltins = false;
// If the declaration we're planning to build will be a function
// or object with linkage, then look for another declaration with
// linkage (C99 6.2.2p4-5 and C++ [basic.link]p6).
//
// If the declaration we're planning to build will be declared with
// external linkage in the translation unit, create any builtin with
// the same name.
if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef)
/* Do nothing*/;
else if (CurContext->isFunctionOrMethod() &&
(D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern ||
R->isFunctionType())) {
IsLinkageLookup = true;
CreateBuiltins =
CurContext->getEnclosingNamespaceContext()->isTranslationUnit();
} else if (CurContext->getRedeclContext()->isTranslationUnit() &&
D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static)
CreateBuiltins = true;
if (IsLinkageLookup) {
Previous.clear(LookupRedeclarationWithLinkage);
Previous.setRedeclarationKind(
RedeclarationKind::ForExternalRedeclaration);
}
LookupName(Previous, S, CreateBuiltins);
} else { // Something like "int foo::x;"
LookupQualifiedName(Previous, DC);
// C++ [dcl.meaning]p1:
// When the declarator-id is qualified, the declaration shall refer to a
// previously declared member of the class or namespace to which the
// qualifier refers (or, in the case of a namespace, of an element of the
// inline namespace set of that namespace (7.3.1)) or to a specialization
// thereof; [...]
//
// Note that we already checked the context above, and that we do not have
// enough information to make sure that Previous contains the declaration
// we want to match. For example, given:
//
// class X {
// void f();
// void f(float);
// };
//
// void X::f(int) { } // ill-formed
//
// In this case, Previous will point to the overload set
// containing the two f's declared in X, but neither of them
// matches.
RemoveUsingDecls(Previous);
}
if (auto *TPD = Previous.getAsSingle<NamedDecl>();
TPD && TPD->isTemplateParameter()) {
// Older versions of clang allowed the names of function/variable templates
// to shadow the names of their template parameters. For the compatibility
// purposes we detect such cases and issue a default-to-error warning that
// can be disabled with -Wno-strict-primary-template-shadow.
if (!D.isInvalidType()) {
bool AllowForCompatibility = false;
if (Scope *DeclParent = S->getDeclParent();
Scope *TemplateParamParent = S->getTemplateParamParent()) {
AllowForCompatibility = DeclParent->Contains(*TemplateParamParent) &&
TemplateParamParent->isDeclScope(TPD);
}
DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), TPD,
AllowForCompatibility);
}
// Just pretend that we didn't see the previous declaration.
Previous.clear();
}
if (!R->isFunctionType() && DiagnoseClassNameShadow(DC, NameInfo))
// Forget that the previous declaration is the injected-class-name.
Previous.clear();
// In C++, the previous declaration we find might be a tag type
// (class or enum). In this case, the new declaration will hide the
// tag type. Note that this applies to functions, function templates, and
// variables, but not to typedefs (C++ [dcl.typedef]p4) or variable templates.
if (Previous.isSingleTagDecl() &&
D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
(TemplateParamLists.size() == 0 || R->isFunctionType()))
Previous.clear();
// Check that there are no default arguments other than in the parameters
// of a function declaration (C++ only).
if (getLangOpts().CPlusPlus)
CheckExtraCXXDefaultArguments(D);
/// Get the innermost enclosing declaration scope.
S = S->getDeclParent();
NamedDecl *New;
bool AddToScope = true;
if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
if (TemplateParamLists.size()) {
Diag(D.getIdentifierLoc(), diag::err_template_typedef);
return nullptr;
}
New = ActOnTypedefDeclarator(S, D, DC, TInfo, Previous);
} else if (R->isFunctionType()) {
New = ActOnFunctionDeclarator(S, D, DC, TInfo, Previous,
TemplateParamLists,
AddToScope);
} else {
New = ActOnVariableDeclarator(S, D, DC, TInfo, Previous, TemplateParamLists,
AddToScope);
}
if (!New)
return nullptr;
warnOnCTypeHiddenInCPlusPlus(New);
// If this has an identifier and is not a function template specialization,
// add it to the scope stack.
if (New->getDeclName() && AddToScope)
PushOnScopeChains(New, S);
if (OpenMP().isInOpenMPDeclareTargetContext())
OpenMP().checkDeclIsAllowedInOpenMPTarget(nullptr, New);
return New;
}
/// Helper method to turn variable array types into constant array
/// types in certain situations which would otherwise be errors (for
/// GCC compatibility).
static QualType TryToFixInvalidVariablyModifiedType(QualType T,
ASTContext &Context,
bool &SizeIsNegative,
llvm::APSInt &Oversized) {
// This method tries to turn a variable array into a constant
// array even when the size isn't an ICE. This is necessary
// for compatibility with code that depends on gcc's buggy
// constant expression folding, like struct {char x[(int)(char*)2];}
SizeIsNegative = false;
Oversized = 0;
if (T->isDependentType())
return QualType();
QualifierCollector Qs;
const Type *Ty = Qs.strip(T);
if (const PointerType* PTy = dyn_cast<PointerType>(Ty)) {
QualType Pointee = PTy->getPointeeType();
QualType FixedType =
TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative,
Oversized);
if (FixedType.isNull()) return FixedType;
FixedType = Context.getPointerType(FixedType);
return Qs.apply(Context, FixedType);
}
if (const ParenType* PTy = dyn_cast<ParenType>(Ty)) {
QualType Inner = PTy->getInnerType();
QualType FixedType =
TryToFixInvalidVariablyModifiedType(Inner, Context, SizeIsNegative,
Oversized);
if (FixedType.isNull()) return FixedType;
FixedType = Context.getParenType(FixedType);
return Qs.apply(Context, FixedType);
}
const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T);
if (!VLATy)
return QualType();
QualType ElemTy = VLATy->getElementType();
if (ElemTy->isVariablyModifiedType()) {
ElemTy = TryToFixInvalidVariablyModifiedType(ElemTy, Context,
SizeIsNegative, Oversized);
if (ElemTy.isNull())
return QualType();
}
Expr::EvalResult Result;
if (!VLATy->getSizeExpr() ||
!VLATy->getSizeExpr()->EvaluateAsInt(Result, Context))
return QualType();
llvm::APSInt Res = Result.Val.getInt();
// Check whether the array size is negative.
if (Res.isSigned() && Res.isNegative()) {
SizeIsNegative = true;
return QualType();
}
// Check whether the array is too large to be addressed.
unsigned ActiveSizeBits =
(!ElemTy->isDependentType() && !ElemTy->isVariablyModifiedType() &&
!ElemTy->isIncompleteType() && !ElemTy->isUndeducedType())
? ConstantArrayType::getNumAddressingBits(Context, ElemTy, Res)
: Res.getActiveBits();
if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) {
Oversized = Res;
return QualType();
}
QualType FoldedArrayType = Context.getConstantArrayType(
ElemTy, Res, VLATy->getSizeExpr(), ArraySizeModifier::Normal, 0);
return Qs.apply(Context, FoldedArrayType);
}
static void
FixInvalidVariablyModifiedTypeLoc(TypeLoc SrcTL, TypeLoc DstTL) {
SrcTL = SrcTL.getUnqualifiedLoc();
DstTL = DstTL.getUnqualifiedLoc();
if (PointerTypeLoc SrcPTL = SrcTL.getAs<PointerTypeLoc>()) {
PointerTypeLoc DstPTL = DstTL.castAs<PointerTypeLoc>();
FixInvalidVariablyModifiedTypeLoc(SrcPTL.getPointeeLoc(),
DstPTL.getPointeeLoc());
DstPTL.setStarLoc(SrcPTL.getStarLoc());
return;
}
if (ParenTypeLoc SrcPTL = SrcTL.getAs<ParenTypeLoc>()) {
ParenTypeLoc DstPTL = DstTL.castAs<ParenTypeLoc>();
FixInvalidVariablyModifiedTypeLoc(SrcPTL.getInnerLoc(),
DstPTL.getInnerLoc());
DstPTL.setLParenLoc(SrcPTL.getLParenLoc());
DstPTL.setRParenLoc(SrcPTL.getRParenLoc());
return;
}
ArrayTypeLoc SrcATL = SrcTL.castAs<ArrayTypeLoc>();
ArrayTypeLoc DstATL = DstTL.castAs<ArrayTypeLoc>();
TypeLoc SrcElemTL = SrcATL.getElementLoc();
TypeLoc DstElemTL = DstATL.getElementLoc();
if (VariableArrayTypeLoc SrcElemATL =
SrcElemTL.getAs<VariableArrayTypeLoc>()) {
ConstantArrayTypeLoc DstElemATL = DstElemTL.castAs<ConstantArrayTypeLoc>();
FixInvalidVariablyModifiedTypeLoc(SrcElemATL, DstElemATL);
} else {
DstElemTL.initializeFullCopy(SrcElemTL);
}
DstATL.setLBracketLoc(SrcATL.getLBracketLoc());
DstATL.setSizeExpr(SrcATL.getSizeExpr());
DstATL.setRBracketLoc(SrcATL.getRBracketLoc());
}
/// Helper method to turn variable array types into constant array
/// types in certain situations which would otherwise be errors (for
/// GCC compatibility).
static TypeSourceInfo*
TryToFixInvalidVariablyModifiedTypeSourceInfo(TypeSourceInfo *TInfo,
ASTContext &Context,
bool &SizeIsNegative,
llvm::APSInt &Oversized) {
QualType FixedTy
= TryToFixInvalidVariablyModifiedType(TInfo->getType(), Context,
SizeIsNegative, Oversized);
if (FixedTy.isNull())
return nullptr;
TypeSourceInfo *FixedTInfo = Context.getTrivialTypeSourceInfo(FixedTy);
FixInvalidVariablyModifiedTypeLoc(TInfo->getTypeLoc(),
FixedTInfo->getTypeLoc());
return FixedTInfo;
}
bool Sema::tryToFixVariablyModifiedVarType(TypeSourceInfo *&TInfo,
QualType &T, SourceLocation Loc,
unsigned FailedFoldDiagID) {
bool SizeIsNegative;
llvm::APSInt Oversized;
TypeSourceInfo *FixedTInfo = TryToFixInvalidVariablyModifiedTypeSourceInfo(
TInfo, Context, SizeIsNegative, Oversized);
if (FixedTInfo) {
Diag(Loc, diag::ext_vla_folded_to_constant);
TInfo = FixedTInfo;
T = FixedTInfo->getType();
return true;
}
if (SizeIsNegative)
Diag(Loc, diag::err_typecheck_negative_array_size);
else if (Oversized.getBoolValue())
Diag(Loc, diag::err_array_too_large) << toString(Oversized, 10);
else if (FailedFoldDiagID)
Diag(Loc, FailedFoldDiagID);
return false;
}
void
Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, Scope *S) {
if (!getLangOpts().CPlusPlus &&
ND->getLexicalDeclContext()->getRedeclContext()->isTranslationUnit())
// Don't need to track declarations in the TU in C.
return;
// Note that we have a locally-scoped external with this name.
Context.getExternCContextDecl()->makeDeclVisibleInContext(ND);
}
NamedDecl *Sema::findLocallyScopedExternCDecl(DeclarationName Name) {
// FIXME: We can have multiple results via __attribute__((overloadable)).
auto Result = Context.getExternCContextDecl()->lookup(Name);
return Result.empty() ? nullptr : *Result.begin();
}
void Sema::DiagnoseFunctionSpecifiers(const DeclSpec &DS) {
// FIXME: We should probably indicate the identifier in question to avoid
// confusion for constructs like "virtual int a(), b;"
if (DS.isVirtualSpecified())
Diag(DS.getVirtualSpecLoc(),
diag::err_virtual_non_function);
if (DS.hasExplicitSpecifier())
Diag(DS.getExplicitSpecLoc(),
diag::err_explicit_non_function);
if (DS.isNoreturnSpecified())
Diag(DS.getNoreturnSpecLoc(),
diag::err_noreturn_non_function);
}
NamedDecl*
Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC,
TypeSourceInfo *TInfo, LookupResult &Previous) {
// Typedef declarators cannot be qualified (C++ [dcl.meaning]p1).
if (D.getCXXScopeSpec().isSet()) {
Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator)
<< D.getCXXScopeSpec().getRange();
D.setInvalidType();
// Pretend we didn't see the scope specifier.
DC = CurContext;
Previous.clear();
}
DiagnoseFunctionSpecifiers(D.getDeclSpec());
if (D.getDeclSpec().isInlineSpecified())
Diag(D.getDeclSpec().getInlineSpecLoc(),
(getLangOpts().MSVCCompat && !getLangOpts().CPlusPlus)
? diag::warn_ms_inline_non_function
: diag::err_inline_non_function)
<< getLangOpts().CPlusPlus17;
if (D.getDeclSpec().hasConstexprSpecifier())
Diag(D.getDeclSpec().getConstexprSpecLoc(), diag::err_invalid_constexpr)
<< 1 << static_cast<int>(D.getDeclSpec().getConstexprSpecifier());
if (D.getName().getKind() != UnqualifiedIdKind::IK_Identifier) {
if (D.getName().getKind() == UnqualifiedIdKind::IK_DeductionGuideName)
Diag(D.getName().StartLocation,
diag::err_deduction_guide_invalid_specifier)
<< "typedef";
else
Diag(D.getName().StartLocation, diag::err_typedef_not_identifier)
<< D.getName().getSourceRange();
return nullptr;
}
TypedefDecl *NewTD = ParseTypedefDecl(S, D, TInfo->getType(), TInfo);
if (!NewTD) return nullptr;
// Handle attributes prior to checking for duplicates in MergeVarDecl
ProcessDeclAttributes(S, NewTD, D);
CheckTypedefForVariablyModifiedType(S, NewTD);
bool Redeclaration = D.isRedeclaration();
NamedDecl *ND = ActOnTypedefNameDecl(S, DC, NewTD, Previous, Redeclaration);
D.setRedeclaration(Redeclaration);
return ND;
}
void
Sema::CheckTypedefForVariablyModifiedType(Scope *S, TypedefNameDecl *NewTD) {
// C99 6.7.7p2: If a typedef name specifies a variably modified type
// then it shall have block scope.
// Note that variably modified types must be fixed before merging the decl so
// that redeclarations will match.
TypeSourceInfo *TInfo = NewTD->getTypeSourceInfo();
QualType T = TInfo->getType();
if (T->isVariablyModifiedType()) {
setFunctionHasBranchProtectedScope();
if (S->getFnParent() == nullptr) {
bool SizeIsNegative;
llvm::APSInt Oversized;
TypeSourceInfo *FixedTInfo =
TryToFixInvalidVariablyModifiedTypeSourceInfo(TInfo, Context,
SizeIsNegative,
Oversized);
if (FixedTInfo) {
Diag(NewTD->getLocation(), diag::ext_vla_folded_to_constant);
NewTD->setTypeSourceInfo(FixedTInfo);
} else {
if (SizeIsNegative)
Diag(NewTD->getLocation(), diag::err_typecheck_negative_array_size);
else if (T->isVariableArrayType())
Diag(NewTD->getLocation(), diag::err_vla_decl_in_file_scope);
else if (Oversized.getBoolValue())
Diag(NewTD->getLocation(), diag::err_array_too_large)
<< toString(Oversized, 10);
else
Diag(NewTD->getLocation(), diag::err_vm_decl_in_file_scope);
NewTD->setInvalidDecl();
}
}
}
}
NamedDecl*
Sema::ActOnTypedefNameDecl(Scope *S, DeclContext *DC, TypedefNameDecl *NewTD,
LookupResult &Previous, bool &Redeclaration) {
// Find the shadowed declaration before filtering for scope.
NamedDecl *ShadowedDecl = getShadowedDeclaration(NewTD, Previous);
// Merge the decl with the existing one if appropriate. If the decl is
// in an outer scope, it isn't the same thing.
FilterLookupForScope(Previous, DC, S, /*ConsiderLinkage*/false,
/*AllowInlineNamespace*/false);
filterNonConflictingPreviousTypedefDecls(*this, NewTD, Previous);
if (!Previous.empty()) {
Redeclaration = true;
MergeTypedefNameDecl(S, NewTD, Previous);
} else {
inferGslPointerAttribute(NewTD);
}
if (ShadowedDecl && !Redeclaration)
CheckShadow(NewTD, ShadowedDecl, Previous);
// If this is the C FILE type, notify the AST context.
if (IdentifierInfo *II = NewTD->getIdentifier())
if (!NewTD->isInvalidDecl() &&
NewTD->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
switch (II->getNotableIdentifierID()) {
case tok::NotableIdentifierKind::FILE:
Context.setFILEDecl(NewTD);
break;
case tok::NotableIdentifierKind::jmp_buf:
Context.setjmp_bufDecl(NewTD);
break;
case tok::NotableIdentifierKind::sigjmp_buf:
Context.setsigjmp_bufDecl(NewTD);
break;
case tok::NotableIdentifierKind::ucontext_t:
Context.setucontext_tDecl(NewTD);
break;
case tok::NotableIdentifierKind::float_t:
case tok::NotableIdentifierKind::double_t:
NewTD->addAttr(AvailableOnlyInDefaultEvalMethodAttr::Create(Context));
break;
default:
break;
}
}
return NewTD;
}
/// Determines whether the given declaration is an out-of-scope
/// previous declaration.
///
/// This routine should be invoked when name lookup has found a
/// previous declaration (PrevDecl) that is not in the scope where a
/// new declaration by the same name is being introduced. If the new
/// declaration occurs in a local scope, previous declarations with
/// linkage may still be considered previous declarations (C99
/// 6.2.2p4-5, C++ [basic.link]p6).
///
/// \param PrevDecl the previous declaration found by name
/// lookup
///
/// \param DC the context in which the new declaration is being
/// declared.
///
/// \returns true if PrevDecl is an out-of-scope previous declaration
/// for a new delcaration with the same name.
static bool
isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC,
ASTContext &Context) {
if (!PrevDecl)
return false;
if (!PrevDecl->hasLinkage())
return false;
if (Context.getLangOpts().CPlusPlus) {
// C++ [basic.link]p6:
// If there is a visible declaration of an entity with linkage
// having the same name and type, ignoring entities declared
// outside the innermost enclosing namespace scope, the block
// scope declaration declares that same entity and receives the
// linkage of the previous declaration.
DeclContext *OuterContext = DC->getRedeclContext();
if (!OuterContext->isFunctionOrMethod())
// This rule only applies to block-scope declarations.
return false;
DeclContext *PrevOuterContext = PrevDecl->getDeclContext();
if (PrevOuterContext->isRecord())
// We found a member function: ignore it.
return false;
// Find the innermost enclosing namespace for the new and
// previous declarations.
OuterContext = OuterContext->getEnclosingNamespaceContext();
PrevOuterContext = PrevOuterContext->getEnclosingNamespaceContext();
// The previous declaration is in a different namespace, so it
// isn't the same function.
if (!OuterContext->Equals(PrevOuterContext))
return false;
}
return true;
}
static void SetNestedNameSpecifier(Sema &S, DeclaratorDecl *DD, Declarator &D) {
CXXScopeSpec &SS = D.getCXXScopeSpec();
if (!SS.isSet()) return;
DD->setQualifierInfo(SS.getWithLocInContext(S.Context));
}
void Sema::deduceOpenCLAddressSpace(ValueDecl *Decl) {
if (Decl->getType().hasAddressSpace())
return;
if (Decl->getType()->isDependentType())
return;
if (VarDecl *Var = dyn_cast<VarDecl>(Decl)) {
QualType Type = Var->getType();
if (Type->isSamplerT() || Type->isVoidType())
return;
LangAS ImplAS = LangAS::opencl_private;
// OpenCL C v3.0 s6.7.8 - For OpenCL C 2.0 or with the
// __opencl_c_program_scope_global_variables feature, the address space
// for a variable at program scope or a static or extern variable inside
// a function are inferred to be __global.
if (getOpenCLOptions().areProgramScopeVariablesSupported(getLangOpts()) &&
Var->hasGlobalStorage())
ImplAS = LangAS::opencl_global;
// If the original type from a decayed type is an array type and that array
// type has no address space yet, deduce it now.
if (auto DT = dyn_cast<DecayedType>(Type)) {
auto OrigTy = DT->getOriginalType();
if (!OrigTy.hasAddressSpace() && OrigTy->isArrayType()) {
// Add the address space to the original array type and then propagate
// that to the element type through `getAsArrayType`.
OrigTy = Context.getAddrSpaceQualType(OrigTy, ImplAS);
OrigTy = QualType(Context.getAsArrayType(OrigTy), 0);
// Re-generate the decayed type.
Type = Context.getDecayedType(OrigTy);
}
}
Type = Context.getAddrSpaceQualType(Type, ImplAS);
// Apply any qualifiers (including address space) from the array type to
// the element type. This implements C99 6.7.3p8: "If the specification of
// an array type includes any type qualifiers, the element type is so
// qualified, not the array type."
if (Type->isArrayType())
Type = QualType(Context.getAsArrayType(Type), 0);
Decl->setType(Type);
}
}
static void checkWeakAttr(Sema &S, NamedDecl &ND) {
// 'weak' only applies to declarations with external linkage.
if (WeakAttr *Attr = ND.getAttr<WeakAttr>()) {
if (!ND.isExternallyVisible()) {
S.Diag(Attr->getLocation(), diag::err_attribute_weak_static);
ND.dropAttr<WeakAttr>();
}
}
}
static void checkWeakRefAttr(Sema &S, NamedDecl &ND) {
if (WeakRefAttr *Attr = ND.getAttr<WeakRefAttr>()) {
if (ND.isExternallyVisible()) {
S.Diag(Attr->getLocation(), diag::err_attribute_weakref_not_static);
ND.dropAttrs<WeakRefAttr, AliasAttr>();
}
}
}
static void checkAliasAttr(Sema &S, NamedDecl &ND) {
if (auto *VD = dyn_cast<VarDecl>(&ND)) {
if (VD->hasInit()) {
if (const auto *Attr = VD->getAttr<AliasAttr>()) {
assert(VD->isThisDeclarationADefinition() &&
!VD->isExternallyVisible() && "Broken AliasAttr handled late!");
S.Diag(Attr->getLocation(), diag::err_alias_is_definition) << VD << 0;
VD->dropAttr<AliasAttr>();
}
}
}
}
static void checkSelectAnyAttr(Sema &S, NamedDecl &ND) {
// 'selectany' only applies to externally visible variable declarations.
// It does not apply to functions.
if (SelectAnyAttr *Attr = ND.getAttr<SelectAnyAttr>()) {
if (isa<FunctionDecl>(ND) || !ND.isExternallyVisible()) {
S.Diag(Attr->getLocation(),
diag::err_attribute_selectany_non_extern_data);
ND.dropAttr<SelectAnyAttr>();
}
}
}
static void checkHybridPatchableAttr(Sema &S, NamedDecl &ND) {
if (HybridPatchableAttr *Attr = ND.getAttr<HybridPatchableAttr>()) {
if (!ND.isExternallyVisible())
S.Diag(Attr->getLocation(),
diag::warn_attribute_hybrid_patchable_non_extern);
}
}
static void checkInheritableAttr(Sema &S, NamedDecl &ND) {
if (const InheritableAttr *Attr = getDLLAttr(&ND)) {
auto *VD = dyn_cast<VarDecl>(&ND);
bool IsAnonymousNS = false;
bool IsMicrosoft = S.Context.getTargetInfo().getCXXABI().isMicrosoft();
if (VD) {
const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(VD->getDeclContext());
while (NS && !IsAnonymousNS) {
IsAnonymousNS = NS->isAnonymousNamespace();
NS = dyn_cast<NamespaceDecl>(NS->getParent());
}
}
// dll attributes require external linkage. Static locals may have external
// linkage but still cannot be explicitly imported or exported.
// In Microsoft mode, a variable defined in anonymous namespace must have
// external linkage in order to be exported.
bool AnonNSInMicrosoftMode = IsAnonymousNS && IsMicrosoft;
if ((ND.isExternallyVisible() && AnonNSInMicrosoftMode) ||
(!AnonNSInMicrosoftMode &&
(!ND.isExternallyVisible() || (VD && VD->isStaticLocal())))) {
S.Diag(ND.getLocation(), diag::err_attribute_dll_not_extern)
<< &ND << Attr;
ND.setInvalidDecl();
}
}
}
static void checkLifetimeBoundAttr(Sema &S, NamedDecl &ND) {
// Check the attributes on the function type and function params, if any.
if (const auto *FD = dyn_cast<FunctionDecl>(&ND)) {
FD = FD->getMostRecentDecl();
// Don't declare this variable in the second operand of the for-statement;
// GCC miscompiles that by ending its lifetime before evaluating the
// third operand. See gcc.gnu.org/PR86769.
AttributedTypeLoc ATL;
for (TypeLoc TL = FD->getTypeSourceInfo()->getTypeLoc();
(ATL = TL.getAsAdjusted<AttributedTypeLoc>());
TL = ATL.getModifiedLoc()) {
// The [[lifetimebound]] attribute can be applied to the implicit object
// parameter of a non-static member function (other than a ctor or dtor)
// by applying it to the function type.
if (const auto *A = ATL.getAttrAs<LifetimeBoundAttr>()) {
const auto *MD = dyn_cast<CXXMethodDecl>(FD);
int NoImplicitObjectError = -1;
if (!MD)
NoImplicitObjectError = 0;
else if (MD->isStatic())
NoImplicitObjectError = 1;
else if (MD->isExplicitObjectMemberFunction())
NoImplicitObjectError = 2;
if (NoImplicitObjectError != -1) {
S.Diag(A->getLocation(), diag::err_lifetimebound_no_object_param)
<< NoImplicitObjectError << A->getRange();
} else if (isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD)) {
S.Diag(A->getLocation(), diag::err_lifetimebound_ctor_dtor)
<< isa<CXXDestructorDecl>(MD) << A->getRange();
} else if (MD->getReturnType()->isVoidType()) {
S.Diag(
MD->getLocation(),
diag::
err_lifetimebound_implicit_object_parameter_void_return_type);
}
}
}
for (unsigned int I = 0; I < FD->getNumParams(); ++I) {
const ParmVarDecl *P = FD->getParamDecl(I);
// The [[lifetimebound]] attribute can be applied to a function parameter
// only if the function returns a value.
if (auto *A = P->getAttr<LifetimeBoundAttr>()) {
if (!isa<CXXConstructorDecl>(FD) && FD->getReturnType()->isVoidType()) {
S.Diag(A->getLocation(),
diag::err_lifetimebound_parameter_void_return_type);
}
}
}
}
}
static void checkAttributesAfterMerging(Sema &S, NamedDecl &ND) {
// Ensure that an auto decl is deduced otherwise the checks below might cache
// the wrong linkage.
assert(S.ParsingInitForAutoVars.count(&ND) == 0);
checkWeakAttr(S, ND);
checkWeakRefAttr(S, ND);
checkAliasAttr(S, ND);
checkSelectAnyAttr(S, ND);
checkHybridPatchableAttr(S, ND);
checkInheritableAttr(S, ND);
checkLifetimeBoundAttr(S, ND);
}
static void checkDLLAttributeRedeclaration(Sema &S, NamedDecl *OldDecl,
NamedDecl *NewDecl,
bool IsSpecialization,
bool IsDefinition) {
if (OldDecl->isInvalidDecl() || NewDecl->isInvalidDecl())
return;
bool IsTemplate = false;
if (TemplateDecl *OldTD = dyn_cast<TemplateDecl>(OldDecl)) {
OldDecl = OldTD->getTemplatedDecl();
IsTemplate = true;
if (!IsSpecialization)
IsDefinition = false;
}
if (TemplateDecl *NewTD = dyn_cast<TemplateDecl>(NewDecl)) {
NewDecl = NewTD->getTemplatedDecl();
IsTemplate = true;
}
if (!OldDecl || !NewDecl)
return;
const DLLImportAttr *OldImportAttr = OldDecl->getAttr<DLLImportAttr>();
const DLLExportAttr *OldExportAttr = OldDecl->getAttr<DLLExportAttr>();
const DLLImportAttr *NewImportAttr = NewDecl->getAttr<DLLImportAttr>();
const DLLExportAttr *NewExportAttr = NewDecl->getAttr<DLLExportAttr>();
// dllimport and dllexport are inheritable attributes so we have to exclude
// inherited attribute instances.
bool HasNewAttr = (NewImportAttr && !NewImportAttr->isInherited()) ||
(NewExportAttr && !NewExportAttr->isInherited());
// A redeclaration is not allowed to add a dllimport or dllexport attribute,
// the only exception being explicit specializations.
// Implicitly generated declarations are also excluded for now because there
// is no other way to switch these to use dllimport or dllexport.
bool AddsAttr = !(OldImportAttr || OldExportAttr) && HasNewAttr;
if (AddsAttr && !IsSpecialization && !OldDecl->isImplicit()) {
// Allow with a warning for free functions and global variables.
bool JustWarn = false;
if (!OldDecl->isCXXClassMember()) {
auto *VD = dyn_cast<VarDecl>(OldDecl);
if (VD && !VD->getDescribedVarTemplate())
JustWarn = true;
auto *FD = dyn_cast<FunctionDecl>(OldDecl);
if (FD && FD->getTemplatedKind() == FunctionDecl::TK_NonTemplate)
JustWarn = true;
}
// We cannot change a declaration that's been used because IR has already
// been emitted. Dllimported functions will still work though (modulo
// address equality) as they can use the thunk.
if (OldDecl->isUsed())
if (!isa<FunctionDecl>(OldDecl) || !NewImportAttr)
JustWarn = false;
unsigned DiagID = JustWarn ? diag::warn_attribute_dll_redeclaration
: diag::err_attribute_dll_redeclaration;
S.Diag(NewDecl->getLocation(), DiagID)
<< NewDecl
<< (NewImportAttr ? (const Attr *)NewImportAttr : NewExportAttr);
S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);
if (!JustWarn) {
NewDecl->setInvalidDecl();
return;
}
}
// A redeclaration is not allowed to drop a dllimport attribute, the only
// exceptions being inline function definitions (except for function
// templates), local extern declarations, qualified friend declarations or
// special MSVC extension: in the last case, the declaration is treated as if
// it were marked dllexport.
bool IsInline = false, IsStaticDataMember = false, IsQualifiedFriend = false;
bool IsMicrosoftABI = S.Context.getTargetInfo().shouldDLLImportComdatSymbols();
if (const auto *VD = dyn_cast<VarDecl>(NewDecl)) {
// Ignore static data because out-of-line definitions are diagnosed
// separately.
IsStaticDataMember = VD->isStaticDataMember();
IsDefinition = VD->isThisDeclarationADefinition(S.Context) !=
VarDecl::DeclarationOnly;
} else if (const auto *FD = dyn_cast<FunctionDecl>(NewDecl)) {
IsInline = FD->isInlined();
IsQualifiedFriend = FD->getQualifier() &&
FD->getFriendObjectKind() == Decl::FOK_Declared;
}
if (OldImportAttr && !HasNewAttr &&
(!IsInline || (IsMicrosoftABI && IsTemplate)) && !IsStaticDataMember &&
!NewDecl->isLocalExternDecl() && !IsQualifiedFriend) {
if (IsMicrosoftABI && IsDefinition) {
if (IsSpecialization) {
S.Diag(
NewDecl->getLocation(),
diag::err_attribute_dllimport_function_specialization_definition);
S.Diag(OldImportAttr->getLocation(), diag::note_attribute);
NewDecl->dropAttr<DLLImportAttr>();
} else {
S.Diag(NewDecl->getLocation(),
diag::warn_redeclaration_without_import_attribute)
<< NewDecl;
S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);
NewDecl->dropAttr<DLLImportAttr>();
NewDecl->addAttr(DLLExportAttr::CreateImplicit(
S.Context, NewImportAttr->getRange()));
}
} else if (IsMicrosoftABI && IsSpecialization) {
assert(!IsDefinition);
// MSVC allows this. Keep the inherited attribute.
} else {
S.Diag(NewDecl->getLocation(),
diag::warn_redeclaration_without_attribute_prev_attribute_ignored)
<< NewDecl << OldImportAttr;
S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);
S.Diag(OldImportAttr->getLocation(), diag::note_previous_attribute);
OldDecl->dropAttr<DLLImportAttr>();
NewDecl->dropAttr<DLLImportAttr>();
}
} else if (IsInline && OldImportAttr && !IsMicrosoftABI) {
// In MinGW, seeing a function declared inline drops the dllimport
// attribute.
OldDecl->dropAttr<DLLImportAttr>();
NewDecl->dropAttr<DLLImportAttr>();
S.Diag(NewDecl->getLocation(),
diag::warn_dllimport_dropped_from_inline_function)
<< NewDecl << OldImportAttr;
}
// A specialization of a class template member function is processed here
// since it's a redeclaration. If the parent class is dllexport, the
// specialization inherits that attribute. This doesn't happen automatically
// since the parent class isn't instantiated until later.
if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewDecl)) {
if (MD->getTemplatedKind() == FunctionDecl::TK_MemberSpecialization &&
!NewImportAttr && !NewExportAttr) {
if (const DLLExportAttr *ParentExportAttr =
MD->getParent()->getAttr<DLLExportAttr>()) {
DLLExportAttr *NewAttr = ParentExportAttr->clone(S.Context);
NewAttr->setInherited(true);
NewDecl->addAttr(NewAttr);
}
}
}
}
/// Given that we are within the definition of the given function,
/// will that definition behave like C99's 'inline', where the
/// definition is discarded except for optimization purposes?
static bool isFunctionDefinitionDiscarded(Sema &S, FunctionDecl *FD) {
// Try to avoid calling GetGVALinkageForFunction.
// All cases of this require the 'inline' keyword.
if (!FD->isInlined()) return false;
// This is only possible in C++ with the gnu_inline attribute.
if (S.getLangOpts().CPlusPlus && !FD->hasAttr<GNUInlineAttr>())
return false;
// Okay, go ahead and call the relatively-more-expensive function.
return S.Context.GetGVALinkageForFunction(FD) == GVA_AvailableExternally;
}
/// Determine whether a variable is extern "C" prior to attaching
/// an initializer. We can't just call isExternC() here, because that
/// will also compute and cache whether the declaration is externally
/// visible, which might change when we attach the initializer.
///
/// This can only be used if the declaration is known to not be a
/// redeclaration of an internal linkage declaration.
///
/// For instance:
///
/// auto x = []{};
///
/// Attaching the initializer here makes this declaration not externally
/// visible, because its type has internal linkage.
///
/// FIXME: This is a hack.
template<typename T>
static bool isIncompleteDeclExternC(Sema &S, const T *D) {
if (S.getLangOpts().CPlusPlus) {
// In C++, the overloadable attribute negates the effects of extern "C".
if (!D->isInExternCContext() || D->template hasAttr<OverloadableAttr>())
return false;
// So do CUDA's host/device attributes.
if (S.getLangOpts().CUDA && (D->template hasAttr<CUDADeviceAttr>() ||
D->template hasAttr<CUDAHostAttr>()))
return false;
}
return D->isExternC();
}
static bool shouldConsiderLinkage(const VarDecl *VD) {
const DeclContext *DC = VD->getDeclContext()->getRedeclContext();
if (DC->isFunctionOrMethod() || isa<OMPDeclareReductionDecl>(DC) ||
isa<OMPDeclareMapperDecl>(DC))
return VD->hasExternalStorage();
if (DC->isFileContext())
return true;
if (DC->isRecord())
return false;
if (DC->getDeclKind() == Decl::HLSLBuffer)
return false;
if (isa<RequiresExprBodyDecl>(DC))
return false;
llvm_unreachable("Unexpected context");
}
static bool shouldConsiderLinkage(const FunctionDecl *FD) {
const DeclContext *DC = FD->getDeclContext()->getRedeclContext();
if (DC->isFileContext() || DC->isFunctionOrMethod() ||
isa<OMPDeclareReductionDecl>(DC) || isa<OMPDeclareMapperDecl>(DC))
return true;
if (DC->isRecord())
return false;
llvm_unreachable("Unexpected context");
}
static bool hasParsedAttr(Scope *S, const Declarator &PD,
ParsedAttr::Kind Kind) {
// Check decl attributes on the DeclSpec.
if (PD.getDeclSpec().getAttributes().hasAttribute(Kind))
return true;
// Walk the declarator structure, checking decl attributes that were in a type
// position to the decl itself.
for (unsigned I = 0, E = PD.getNumTypeObjects(); I != E; ++I) {
if (PD.getTypeObject(I).getAttrs().hasAttribute(Kind))
return true;
}
// Finally, check attributes on the decl itself.
return PD.getAttributes().hasAttribute(Kind) ||
PD.getDeclarationAttributes().hasAttribute(Kind);
}
bool Sema::adjustContextForLocalExternDecl(DeclContext *&DC) {
if (!DC->isFunctionOrMethod())
return false;
// If this is a local extern function or variable declared within a function
// template, don't add it into the enclosing namespace scope until it is
// instantiated; it might have a dependent type right now.
if (DC->isDependentContext())
return true;
// C++11 [basic.link]p7:
// When a block scope declaration of an entity with linkage is not found to
// refer to some other declaration, then that entity is a member of the
// innermost enclosing namespace.
//
// Per C++11 [namespace.def]p6, the innermost enclosing namespace is a
// semantically-enclosing namespace, not a lexically-enclosing one.
while (!DC->isFileContext() && !isa<LinkageSpecDecl>(DC))
DC = DC->getParent();
return true;
}
/// Returns true if given declaration has external C language linkage.
static bool isDeclExternC(const Decl *D) {
if (const auto *FD = dyn_cast<FunctionDecl>(D))
return FD->isExternC();
if (const auto *VD = dyn_cast<VarDecl>(D))
return VD->isExternC();
llvm_unreachable("Unknown type of decl!");
}
/// Returns true if there hasn't been any invalid type diagnosed.
static bool diagnoseOpenCLTypes(Sema &Se, VarDecl *NewVD) {
DeclContext *DC = NewVD->getDeclContext();
QualType R = NewVD->getType();
// OpenCL v2.0 s6.9.b - Image type can only be used as a function argument.
// OpenCL v2.0 s6.13.16.1 - Pipe type can only be used as a function
// argument.
if (R->isImageType() || R->isPipeType()) {
Se.Diag(NewVD->getLocation(),
diag::err_opencl_type_can_only_be_used_as_function_parameter)
<< R;
NewVD->setInvalidDecl();
return false;
}
// OpenCL v1.2 s6.9.r:
// The event type cannot be used to declare a program scope variable.
// OpenCL v2.0 s6.9.q:
// The clk_event_t and reserve_id_t types cannot be declared in program
// scope.
if (NewVD->hasGlobalStorage() && !NewVD->isStaticLocal()) {
if (R->isReserveIDT() || R->isClkEventT() || R->isEventT()) {
Se.Diag(NewVD->getLocation(),
diag::err_invalid_type_for_program_scope_var)
<< R;
NewVD->setInvalidDecl();
return false;
}
}
// OpenCL v1.0 s6.8.a.3: Pointers to functions are not allowed.
if (!Se.getOpenCLOptions().isAvailableOption("__cl_clang_function_pointers",
Se.getLangOpts())) {
QualType NR = R.getCanonicalType();
while (NR->isPointerType() || NR->isMemberFunctionPointerType() ||
NR->isReferenceType()) {
if (NR->isFunctionPointerType() || NR->isMemberFunctionPointerType() ||
NR->isFunctionReferenceType()) {
Se.Diag(NewVD->getLocation(), diag::err_opencl_function_pointer)
<< NR->isReferenceType();
NewVD->setInvalidDecl();
return false;
}
NR = NR->getPointeeType();
}
}
if (!Se.getOpenCLOptions().isAvailableOption("cl_khr_fp16",
Se.getLangOpts())) {
// OpenCL v1.2 s6.1.1.1: reject declaring variables of the half and
// half array type (unless the cl_khr_fp16 extension is enabled).
if (Se.Context.getBaseElementType(R)->isHalfType()) {
Se.Diag(NewVD->getLocation(), diag::err_opencl_half_declaration) << R;
NewVD->setInvalidDecl();
return false;
}
}
// OpenCL v1.2 s6.9.r:
// The event type cannot be used with the __local, __constant and __global
// address space qualifiers.
if (R->isEventT()) {
if (R.getAddressSpace() != LangAS::opencl_private) {
Se.Diag(NewVD->getBeginLoc(), diag::err_event_t_addr_space_qual);
NewVD->setInvalidDecl();
return false;
}
}
if (R->isSamplerT()) {
// OpenCL v1.2 s6.9.b p4:
// The sampler type cannot be used with the __local and __global address
// space qualifiers.
if (R.getAddressSpace() == LangAS::opencl_local ||
R.getAddressSpace() == LangAS::opencl_global) {
Se.Diag(NewVD->getLocation(), diag::err_wrong_sampler_addressspace);
NewVD->setInvalidDecl();
}
// OpenCL v1.2 s6.12.14.1:
// A global sampler must be declared with either the constant address
// space qualifier or with the const qualifier.
if (DC->isTranslationUnit() &&
!(R.getAddressSpace() == LangAS::opencl_constant ||
R.isConstQualified())) {
Se.Diag(NewVD->getLocation(), diag::err_opencl_nonconst_global_sampler);
NewVD->setInvalidDecl();
}
if (NewVD->isInvalidDecl())
return false;
}
return true;
}
template <typename AttrTy>
static void copyAttrFromTypedefToDecl(Sema &S, Decl *D, const TypedefType *TT) {
const TypedefNameDecl *TND = TT->getDecl();
if (const auto *Attribute = TND->getAttr<AttrTy>()) {
AttrTy *Clone = Attribute->clone(S.Context);
Clone->setInherited(true);
D->addAttr(Clone);
}
}
// This function emits warning and a corresponding note based on the
// ReadOnlyPlacementAttr attribute. The warning checks that all global variable
// declarations of an annotated type must be const qualified.
static void emitReadOnlyPlacementAttrWarning(Sema &S, const VarDecl *VD) {
QualType VarType = VD->getType().getCanonicalType();
// Ignore local declarations (for now) and those with const qualification.
// TODO: Local variables should not be allowed if their type declaration has
// ReadOnlyPlacementAttr attribute. To be handled in follow-up patch.
if (!VD || VD->hasLocalStorage() || VD->getType().isConstQualified())
return;
if (VarType->isArrayType()) {
// Retrieve element type for array declarations.
VarType = S.getASTContext().getBaseElementType(VarType);
}
const RecordDecl *RD = VarType->getAsRecordDecl();
// Check if the record declaration is present and if it has any attributes.
if (RD == nullptr)
return;
if (const auto *ConstDecl = RD->getAttr<ReadOnlyPlacementAttr>()) {
S.Diag(VD->getLocation(), diag::warn_var_decl_not_read_only) << RD;
S.Diag(ConstDecl->getLocation(), diag::note_enforce_read_only_placement);
return;
}
}
// Checks if VD is declared at global scope or with C language linkage.
static bool isMainVar(DeclarationName Name, VarDecl *VD) {
return Name.getAsIdentifierInfo() &&
Name.getAsIdentifierInfo()->isStr("main") &&
!VD->getDescribedVarTemplate() &&
(VD->getDeclContext()->getRedeclContext()->isTranslationUnit() ||
VD->isExternC());
}
NamedDecl *Sema::ActOnVariableDeclarator(
Scope *S, Declarator &D, DeclContext *DC, TypeSourceInfo *TInfo,
LookupResult &Previous, MultiTemplateParamsArg TemplateParamLists,
bool &AddToScope, ArrayRef<BindingDecl *> Bindings) {
QualType R = TInfo->getType();
DeclarationName Name = GetNameForDeclarator(D).getName();
IdentifierInfo *II = Name.getAsIdentifierInfo();
bool IsPlaceholderVariable = false;
if (D.isDecompositionDeclarator()) {
// Take the name of the first declarator as our name for diagnostic
// purposes.
auto &Decomp = D.getDecompositionDeclarator();
if (!Decomp.bindings().empty()) {
II = Decomp.bindings()[0].Name;
Name = II;
}
} else if (!II) {
Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) << Name;
return nullptr;
}
DeclSpec::SCS SCSpec = D.getDeclSpec().getStorageClassSpec();
StorageClass SC = StorageClassSpecToVarDeclStorageClass(D.getDeclSpec());
if (LangOpts.CPlusPlus && (DC->isClosure() || DC->isFunctionOrMethod()) &&
SC != SC_Static && SC != SC_Extern && II && II->isPlaceholder()) {
IsPlaceholderVariable = true;
if (!Previous.empty()) {
NamedDecl *PrevDecl = *Previous.begin();
bool SameDC = PrevDecl->getDeclContext()->getRedeclContext()->Equals(
DC->getRedeclContext());
if (SameDC && isDeclInScope(PrevDecl, CurContext, S, false)) {
IsPlaceholderVariable = !isa<ParmVarDecl>(PrevDecl);
if (IsPlaceholderVariable)
DiagPlaceholderVariableDefinition(D.getIdentifierLoc());
}
}
}
// dllimport globals without explicit storage class are treated as extern. We
// have to change the storage class this early to get the right DeclContext.
if (SC == SC_None && !DC->isRecord() &&
hasParsedAttr(S, D, ParsedAttr::AT_DLLImport) &&
!hasParsedAttr(S, D, ParsedAttr::AT_DLLExport))
SC = SC_Extern;
DeclContext *OriginalDC = DC;
bool IsLocalExternDecl = SC == SC_Extern &&
adjustContextForLocalExternDecl(DC);
if (SCSpec == DeclSpec::SCS_mutable) {
// mutable can only appear on non-static class members, so it's always
// an error here
Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember);
D.setInvalidType();
SC = SC_None;
}
if (getLangOpts().CPlusPlus11 && SCSpec == DeclSpec::SCS_register &&
!D.getAsmLabel() && !getSourceManager().isInSystemMacro(
D.getDeclSpec().getStorageClassSpecLoc())) {
// In C++11, the 'register' storage class specifier is deprecated.
// Suppress the warning in system macros, it's used in macros in some
// popular C system headers, such as in glibc's htonl() macro.
Diag(D.getDeclSpec().getStorageClassSpecLoc(),
getLangOpts().CPlusPlus17 ? diag::ext_register_storage_class
: diag::warn_deprecated_register)
<< FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
}
DiagnoseFunctionSpecifiers(D.getDeclSpec());
if (!DC->isRecord() && S->getFnParent() == nullptr) {
// C99 6.9p2: The storage-class specifiers auto and register shall not
// appear in the declaration specifiers in an external declaration.
// Global Register+Asm is a GNU extension we support.
if (SC == SC_Auto || (SC == SC_Register && !D.getAsmLabel())) {
Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope);
D.setInvalidType();
}
}
// If this variable has a VLA type and an initializer, try to
// fold to a constant-sized type. This is otherwise invalid.
if (D.hasInitializer() && R->isVariableArrayType())
tryToFixVariablyModifiedVarType(TInfo, R, D.getIdentifierLoc(),
/*DiagID=*/0);
if (AutoTypeLoc TL = TInfo->getTypeLoc().getContainedAutoTypeLoc()) {
const AutoType *AT = TL.getTypePtr();
CheckConstrainedAuto(AT, TL.getConceptNameLoc());
}
bool IsMemberSpecialization = false;
bool IsVariableTemplateSpecialization = false;
bool IsPartialSpecialization = false;
bool IsVariableTemplate = false;
VarDecl *NewVD = nullptr;
VarTemplateDecl *NewTemplate = nullptr;
TemplateParameterList *TemplateParams = nullptr;
if (!getLangOpts().CPlusPlus) {
NewVD = VarDecl::Create(Context, DC, D.getBeginLoc(), D.getIdentifierLoc(),
II, R, TInfo, SC);
if (R->getContainedDeducedType())
ParsingInitForAutoVars.insert(NewVD);
if (D.isInvalidType())
NewVD->setInvalidDecl();
if (NewVD->getType().hasNonTrivialToPrimitiveDestructCUnion() &&
NewVD->hasLocalStorage())
checkNonTrivialCUnion(NewVD->getType(), NewVD->getLocation(),
NonTrivialCUnionContext::AutoVar, NTCUK_Destruct);
} else {
bool Invalid = false;
// Match up the template parameter lists with the scope specifier, then
// determine whether we have a template or a template specialization.
TemplateParams = MatchTemplateParametersToScopeSpecifier(
D.getDeclSpec().getBeginLoc(), D.getIdentifierLoc(),
D.getCXXScopeSpec(),
D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
? D.getName().TemplateId
: nullptr,
TemplateParamLists,
/*never a friend*/ false, IsMemberSpecialization, Invalid);
if (TemplateParams) {
if (DC->isDependentContext()) {
ContextRAII SavedContext(*this, DC);
if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
Invalid = true;
}
if (!TemplateParams->size() &&
D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) {
// There is an extraneous 'template<>' for this variable. Complain
// about it, but allow the declaration of the variable.
Diag(TemplateParams->getTemplateLoc(),
diag::err_template_variable_noparams)
<< II
<< SourceRange(TemplateParams->getTemplateLoc(),
TemplateParams->getRAngleLoc());
TemplateParams = nullptr;
} else {
// Check that we can declare a template here.
if (CheckTemplateDeclScope(S, TemplateParams))
return nullptr;
if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) {
// This is an explicit specialization or a partial specialization.
IsVariableTemplateSpecialization = true;
IsPartialSpecialization = TemplateParams->size() > 0;
} else { // if (TemplateParams->size() > 0)
// This is a template declaration.
IsVariableTemplate = true;
// Only C++1y supports variable templates (N3651).
DiagCompat(D.getIdentifierLoc(), diag_compat::variable_template);
}
}
} else {
// Check that we can declare a member specialization here.
if (!TemplateParamLists.empty() && IsMemberSpecialization &&
CheckTemplateDeclScope(S, TemplateParamLists.back()))
return nullptr;
assert((Invalid ||
D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) &&
"should have a 'template<>' for this decl");
}
bool IsExplicitSpecialization =
IsVariableTemplateSpecialization && !IsPartialSpecialization;
// C++ [temp.expl.spec]p2:
// The declaration in an explicit-specialization shall not be an
// export-declaration. An explicit specialization shall not use a
// storage-class-specifier other than thread_local.
//
// We use the storage-class-specifier from DeclSpec because we may have
// added implicit 'extern' for declarations with __declspec(dllimport)!
if (SCSpec != DeclSpec::SCS_unspecified &&
(IsExplicitSpecialization || IsMemberSpecialization)) {
Diag(D.getDeclSpec().getStorageClassSpecLoc(),
diag::ext_explicit_specialization_storage_class)
<< FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
}
if (CurContext->isRecord()) {
if (SC == SC_Static) {
if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) {
// Walk up the enclosing DeclContexts to check for any that are
// incompatible with static data members.
const DeclContext *FunctionOrMethod = nullptr;
const CXXRecordDecl *AnonStruct = nullptr;
for (DeclContext *Ctxt = DC; Ctxt; Ctxt = Ctxt->getParent()) {
if (Ctxt->isFunctionOrMethod()) {
FunctionOrMethod = Ctxt;
break;
}
const CXXRecordDecl *ParentDecl = dyn_cast<CXXRecordDecl>(Ctxt);
if (ParentDecl && !ParentDecl->getDeclName()) {
AnonStruct = ParentDecl;
break;
}
}
if (FunctionOrMethod) {
// C++ [class.static.data]p5: A local class shall not have static
// data members.
Diag(D.getIdentifierLoc(),
diag::err_static_data_member_not_allowed_in_local_class)
<< Name << RD->getDeclName() << RD->getTagKind();
} else if (AnonStruct) {
// C++ [class.static.data]p4: Unnamed classes and classes contained
// directly or indirectly within unnamed classes shall not contain
// static data members.
Diag(D.getIdentifierLoc(),
diag::err_static_data_member_not_allowed_in_anon_struct)
<< Name << AnonStruct->getTagKind();
Invalid = true;
} else if (RD->isUnion()) {
// C++98 [class.union]p1: If a union contains a static data member,
// the program is ill-formed. C++11 drops this restriction.
DiagCompat(D.getIdentifierLoc(),
diag_compat::static_data_member_in_union)
<< Name;
}
}
} else if (IsVariableTemplate || IsPartialSpecialization) {
// There is no such thing as a member field template.
Diag(D.getIdentifierLoc(), diag::err_template_member)
<< II << TemplateParams->getSourceRange();
// Recover by pretending this is a static data member template.
SC = SC_Static;
}
} else if (DC->isRecord()) {
// This is an out-of-line definition of a static data member.
switch (SC) {
case SC_None:
break;
case SC_Static:
Diag(D.getDeclSpec().getStorageClassSpecLoc(),
diag::err_static_out_of_line)
<< FixItHint::CreateRemoval(
D.getDeclSpec().getStorageClassSpecLoc());
break;
case SC_Auto:
case SC_Register:
case SC_Extern:
// [dcl.stc] p2: The auto or register specifiers shall be applied only
// to names of variables declared in a block or to function parameters.
// [dcl.stc] p6: The extern specifier cannot be used in the declaration
// of class members
Diag(D.getDeclSpec().getStorageClassSpecLoc(),
diag::err_storage_class_for_static_member)
<< FixItHint::CreateRemoval(
D.getDeclSpec().getStorageClassSpecLoc());
break;
case SC_PrivateExtern:
llvm_unreachable("C storage class in c++!");
}
}
if (IsVariableTemplateSpecialization) {
SourceLocation TemplateKWLoc =
TemplateParamLists.size() > 0
? TemplateParamLists[0]->getTemplateLoc()
: SourceLocation();
DeclResult Res = ActOnVarTemplateSpecialization(
S, D, TInfo, Previous, TemplateKWLoc, TemplateParams, SC,
IsPartialSpecialization);
if (Res.isInvalid())
return nullptr;
NewVD = cast<VarDecl>(Res.get());
AddToScope = false;
} else if (D.isDecompositionDeclarator()) {
NewVD = DecompositionDecl::Create(Context, DC, D.getBeginLoc(),
D.getIdentifierLoc(), R, TInfo, SC,
Bindings);
} else
NewVD = VarDecl::Create(Context, DC, D.getBeginLoc(),
D.getIdentifierLoc(), II, R, TInfo, SC);
// If this is supposed to be a variable template, create it as such.
if (IsVariableTemplate) {
NewTemplate =
VarTemplateDecl::Create(Context, DC, D.getIdentifierLoc(), Name,
TemplateParams, NewVD);
NewVD->setDescribedVarTemplate(NewTemplate);
}
// If this decl has an auto type in need of deduction, make a note of the
// Decl so we can diagnose uses of it in its own initializer.
if (R->getContainedDeducedType())
ParsingInitForAutoVars.insert(NewVD);
if (D.isInvalidType() || Invalid) {
NewVD->setInvalidDecl();
if (NewTemplate)
NewTemplate->setInvalidDecl();
}
SetNestedNameSpecifier(*this, NewVD, D);
// If we have any template parameter lists that don't directly belong to
// the variable (matching the scope specifier), store them.
// An explicit variable template specialization does not own any template
// parameter lists.
unsigned VDTemplateParamLists =
(TemplateParams && !IsExplicitSpecialization) ? 1 : 0;
if (TemplateParamLists.size() > VDTemplateParamLists)
NewVD->setTemplateParameterListsInfo(
Context, TemplateParamLists.drop_back(VDTemplateParamLists));
}
if (D.getDeclSpec().isInlineSpecified()) {
if (!getLangOpts().CPlusPlus) {
Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
<< 0;
} else if (CurContext->isFunctionOrMethod()) {
// 'inline' is not allowed on block scope variable declaration.
Diag(D.getDeclSpec().getInlineSpecLoc(),
diag::err_inline_declaration_block_scope) << Name
<< FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
} else {
Diag(D.getDeclSpec().getInlineSpecLoc(),
getLangOpts().CPlusPlus17 ? diag::compat_cxx17_inline_variable
: diag::compat_pre_cxx17_inline_variable);
NewVD->setInlineSpecified();
}
}
// Set the lexical context. If the declarator has a C++ scope specifier, the
// lexical context will be different from the semantic context.
NewVD->setLexicalDeclContext(CurContext);
if (NewTemplate)
NewTemplate->setLexicalDeclContext(CurContext);
if (IsLocalExternDecl) {
if (D.isDecompositionDeclarator())
for (auto *B : Bindings)
B->setLocalExternDecl();
else
NewVD->setLocalExternDecl();
}
bool EmitTLSUnsupportedError = false;
if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec()) {
// C++11 [dcl.stc]p4:
// When thread_local is applied to a variable of block scope the
// storage-class-specifier static is implied if it does not appear
// explicitly.
// Core issue: 'static' is not implied if the variable is declared
// 'extern'.
if (NewVD->hasLocalStorage() &&
(SCSpec != DeclSpec::SCS_unspecified ||
TSCS != DeclSpec::TSCS_thread_local ||
!DC->isFunctionOrMethod()))
Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
diag::err_thread_non_global)
<< DeclSpec::getSpecifierName(TSCS);
else if (!Context.getTargetInfo().isTLSSupported()) {
if (getLangOpts().CUDA || getLangOpts().isTargetDevice()) {
// Postpone error emission until we've collected attributes required to
// figure out whether it's a host or device variable and whether the
// error should be ignored.
EmitTLSUnsupportedError = true;
// We still need to mark the variable as TLS so it shows up in AST with
// proper storage class for other tools to use even if we're not going
// to emit any code for it.
NewVD->setTSCSpec(TSCS);
} else
Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
diag::err_thread_unsupported);
} else
NewVD->setTSCSpec(TSCS);
}
switch (D.getDeclSpec().getConstexprSpecifier()) {
case ConstexprSpecKind::Unspecified:
break;
case ConstexprSpecKind::Consteval:
Diag(D.getDeclSpec().getConstexprSpecLoc(),
diag::err_constexpr_wrong_decl_kind)
<< static_cast<int>(D.getDeclSpec().getConstexprSpecifier());
[[fallthrough]];
case ConstexprSpecKind::Constexpr:
NewVD->setConstexpr(true);
// C++1z [dcl.spec.constexpr]p1:
// A static data member declared with the constexpr specifier is
// implicitly an inline variable.
if (NewVD->isStaticDataMember() &&
(getLangOpts().CPlusPlus17 ||
Context.getTargetInfo().getCXXABI().isMicrosoft()))
NewVD->setImplicitlyInline();
break;
case ConstexprSpecKind::Constinit:
if (!NewVD->hasGlobalStorage())
Diag(D.getDeclSpec().getConstexprSpecLoc(),
diag::err_constinit_local_variable);
else
NewVD->addAttr(
ConstInitAttr::Create(Context, D.getDeclSpec().getConstexprSpecLoc(),
ConstInitAttr::Keyword_constinit));
break;
}
// C99 6.7.4p3
// An inline definition of a function with external linkage shall
// not contain a definition of a modifiable object with static or
// thread storage duration...
// We only apply this when the function is required to be defined
// elsewhere, i.e. when the function is not 'extern inline'. Note
// that a local variable with thread storage duration still has to
// be marked 'static'. Also note that it's possible to get these
// semantics in C++ using __attribute__((gnu_inline)).
if (SC == SC_Static && S->getFnParent() != nullptr &&
!NewVD->getType().isConstQualified()) {
FunctionDecl *CurFD = getCurFunctionDecl();
if (CurFD && isFunctionDefinitionDiscarded(*this, CurFD)) {
Diag(D.getDeclSpec().getStorageClassSpecLoc(),
diag::warn_static_local_in_extern_inline);
MaybeSuggestAddingStaticToDecl(CurFD);
}
}
if (D.getDeclSpec().isModulePrivateSpecified()) {
if (IsVariableTemplateSpecialization)
Diag(NewVD->getLocation(), diag::err_module_private_specialization)
<< (IsPartialSpecialization ? 1 : 0)
<< FixItHint::CreateRemoval(
D.getDeclSpec().getModulePrivateSpecLoc());
else if (IsMemberSpecialization)
Diag(NewVD->getLocation(), diag::err_module_private_specialization)
<< 2
<< FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc());
else if (NewVD->hasLocalStorage())
Diag(NewVD->getLocation(), diag::err_module_private_local)
<< 0 << NewVD
<< SourceRange(D.getDeclSpec().getModulePrivateSpecLoc())
<< FixItHint::CreateRemoval(
D.getDeclSpec().getModulePrivateSpecLoc());
else {
NewVD->setModulePrivate();
if (NewTemplate)
NewTemplate->setModulePrivate();
for (auto *B : Bindings)
B->setModulePrivate();
}
}
if (getLangOpts().OpenCL) {
deduceOpenCLAddressSpace(NewVD);
DeclSpec::TSCS TSC = D.getDeclSpec().getThreadStorageClassSpec();
if (TSC != TSCS_unspecified) {
Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
diag::err_opencl_unknown_type_specifier)
<< getLangOpts().getOpenCLVersionString()
<< DeclSpec::getSpecifierName(TSC) << 1;
NewVD->setInvalidDecl();
}
}
// WebAssembly tables are always in address space 1 (wasm_var). Don't apply
// address space if the table has local storage (semantic checks elsewhere
// will produce an error anyway).
if (const auto *ATy = dyn_cast<ArrayType>(NewVD->getType())) {
if (ATy && ATy->getElementType().isWebAssemblyReferenceType() &&
!NewVD->hasLocalStorage()) {
QualType Type = Context.getAddrSpaceQualType(
NewVD->getType(), Context.getLangASForBuiltinAddressSpace(1));
NewVD->setType(Type);
}
}
// Handle attributes prior to checking for duplicates in MergeVarDecl
ProcessDeclAttributes(S, NewVD, D);
if (getLangOpts().HLSL)
HLSL().ActOnVariableDeclarator(NewVD);
if (getLangOpts().OpenACC)
OpenACC().ActOnVariableDeclarator(NewVD);
// FIXME: This is probably the wrong location to be doing this and we should
// probably be doing this for more attributes (especially for function
// pointer attributes such as format, warn_unused_result, etc.). Ideally
// the code to copy attributes would be generated by TableGen.
if (R->isFunctionPointerType())
if (const auto *TT = R->getAs<TypedefType>())
copyAttrFromTypedefToDecl<AllocSizeAttr>(*this, NewVD, TT);
if (getLangOpts().CUDA || getLangOpts().isTargetDevice()) {
if (EmitTLSUnsupportedError &&
((getLangOpts().CUDA && DeclAttrsMatchCUDAMode(getLangOpts(), NewVD)) ||
(getLangOpts().OpenMPIsTargetDevice &&
OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(NewVD))))
Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
diag::err_thread_unsupported);
if (EmitTLSUnsupportedError &&
(LangOpts.SYCLIsDevice ||
(LangOpts.OpenMP && LangOpts.OpenMPIsTargetDevice)))
targetDiag(D.getIdentifierLoc(), diag::err_thread_unsupported);
// CUDA B.2.5: "__shared__ and __constant__ variables have implied static
// storage [duration]."
if (SC == SC_None && S->getFnParent() != nullptr &&
(NewVD->hasAttr<CUDASharedAttr>() ||
NewVD->hasAttr<CUDAConstantAttr>())) {
NewVD->setStorageClass(SC_Static);
}
}
// Ensure that dllimport globals without explicit storage class are treated as
// extern. The storage class is set above using parsed attributes. Now we can
// check the VarDecl itself.
assert(!NewVD->hasAttr<DLLImportAttr>() ||
NewVD->getAttr<DLLImportAttr>()->isInherited() ||
NewVD->isStaticDataMember() || NewVD->getStorageClass() != SC_None);
// In auto-retain/release, infer strong retension for variables of
// retainable type.
if (getLangOpts().ObjCAutoRefCount && ObjC().inferObjCARCLifetime(NewVD))
NewVD->setInvalidDecl();
// Handle GNU asm-label extension (encoded as an attribute).
if (Expr *E = D.getAsmLabel()) {
// The parser guarantees this is a string.
StringLiteral *SE = cast<StringLiteral>(E);
StringRef Label = SE->getString();
if (S->getFnParent() != nullptr) {
switch (SC) {
case SC_None:
case SC_Auto:
Diag(E->getExprLoc(), diag::warn_asm_label_on_auto_decl) << Label;
break;
case SC_Register:
// Local Named register
if (!Context.getTargetInfo().isValidGCCRegisterName(Label) &&
DeclAttrsMatchCUDAMode(getLangOpts(), getCurFunctionDecl()))
Diag(E->getExprLoc(), diag::err_asm_unknown_register_name) << Label;
break;
case SC_Static:
case SC_Extern:
case SC_PrivateExtern:
break;
}
} else if (SC == SC_Register) {
// Global Named register
if (DeclAttrsMatchCUDAMode(getLangOpts(), NewVD)) {
const auto &TI = Context.getTargetInfo();
bool HasSizeMismatch;
if (!TI.isValidGCCRegisterName(Label))
Diag(E->getExprLoc(), diag::err_asm_unknown_register_name) << Label;
else if (!TI.validateGlobalRegisterVariable(Label,
Context.getTypeSize(R),
HasSizeMismatch))
Diag(E->getExprLoc(), diag::err_asm_invalid_global_var_reg) << Label;
else if (HasSizeMismatch)
Diag(E->getExprLoc(), diag::err_asm_register_size_mismatch) << Label;
}
if (!R->isIntegralType(Context) && !R->isPointerType()) {
Diag(TInfo->getTypeLoc().getBeginLoc(),
diag::err_asm_unsupported_register_type)
<< TInfo->getTypeLoc().getSourceRange();
NewVD->setInvalidDecl(true);
}
}
NewVD->addAttr(AsmLabelAttr::Create(Context, Label, SE->getStrTokenLoc(0)));
} else if (!ExtnameUndeclaredIdentifiers.empty()) {
llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
ExtnameUndeclaredIdentifiers.find(NewVD->getIdentifier());
if (I != ExtnameUndeclaredIdentifiers.end()) {
if (isDeclExternC(NewVD)) {
NewVD->addAttr(I->second);
ExtnameUndeclaredIdentifiers.erase(I);
} else
Diag(NewVD->getLocation(), diag::warn_redefine_extname_not_applied)
<< /*Variable*/1 << NewVD;
}
}
// Find the shadowed declaration before filtering for scope.
NamedDecl *ShadowedDecl = D.getCXXScopeSpec().isEmpty()
? getShadowedDeclaration(NewVD, Previous)
: nullptr;
// Don't consider existing declarations that are in a different
// scope and are out-of-semantic-context declarations (if the new
// declaration has linkage).
FilterLookupForScope(Previous, OriginalDC, S, shouldConsiderLinkage(NewVD),
D.getCXXScopeSpec().isNotEmpty() ||
IsMemberSpecialization ||
IsVariableTemplateSpecialization);
// Check whether the previous declaration is in the same block scope. This
// affects whether we merge types with it, per C++11 [dcl.array]p3.
if (getLangOpts().CPlusPlus &&
NewVD->isLocalVarDecl() && NewVD->hasExternalStorage())
NewVD->setPreviousDeclInSameBlockScope(
Previous.isSingleResult() && !Previous.isShadowed() &&
isDeclInScope(Previous.getFoundDecl(), OriginalDC, S, false));
if (!getLangOpts().CPlusPlus) {
D.setRedeclaration(CheckVariableDeclaration(NewVD, Previous));
} else {
// If this is an explicit specialization of a static data member, check it.
if (IsMemberSpecialization && !IsVariableTemplate &&
!IsVariableTemplateSpecialization && !NewVD->isInvalidDecl() &&
CheckMemberSpecialization(NewVD, Previous))
NewVD->setInvalidDecl();
// Merge the decl with the existing one if appropriate.
if (!Previous.empty()) {
if (Previous.isSingleResult() &&
isa<FieldDecl>(Previous.getFoundDecl()) &&
D.getCXXScopeSpec().isSet()) {
// The user tried to define a non-static data member
// out-of-line (C++ [dcl.meaning]p1).
Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line)
<< D.getCXXScopeSpec().getRange();
Previous.clear();
NewVD->setInvalidDecl();
}
} else if (D.getCXXScopeSpec().isSet() &&
!IsVariableTemplateSpecialization) {
// No previous declaration in the qualifying scope.
Diag(D.getIdentifierLoc(), diag::err_no_member)
<< Name << computeDeclContext(D.getCXXScopeSpec(), true)
<< D.getCXXScopeSpec().getRange();
NewVD->setInvalidDecl();
}
if (!IsPlaceholderVariable)
D.setRedeclaration(CheckVariableDeclaration(NewVD, Previous));
// CheckVariableDeclaration will set NewVD as invalid if something is in
// error like WebAssembly tables being declared as arrays with a non-zero
// size, but then parsing continues and emits further errors on that line.
// To avoid that we check here if it happened and return nullptr.
if (NewVD->getType()->isWebAssemblyTableType() && NewVD->isInvalidDecl())
return nullptr;
if (NewTemplate) {
VarTemplateDecl *PrevVarTemplate =
NewVD->getPreviousDecl()
? NewVD->getPreviousDecl()->getDescribedVarTemplate()
: nullptr;
// Check the template parameter list of this declaration, possibly
// merging in the template parameter list from the previous variable
// template declaration.
if (CheckTemplateParameterList(
TemplateParams,
PrevVarTemplate ? PrevVarTemplate->getTemplateParameters()
: nullptr,
(D.getCXXScopeSpec().isSet() && DC && DC->isRecord() &&
DC->isDependentContext())
? TPC_ClassTemplateMember
: TPC_Other))
NewVD->setInvalidDecl();
// If we are providing an explicit specialization of a static variable
// template, make a note of that.
if (PrevVarTemplate &&
PrevVarTemplate->getInstantiatedFromMemberTemplate())
PrevVarTemplate->setMemberSpecialization();
}
}
// Diagnose shadowed variables iff this isn't a redeclaration.
if (!IsPlaceholderVariable && ShadowedDecl && !D.isRedeclaration())
CheckShadow(NewVD, ShadowedDecl, Previous);
ProcessPragmaWeak(S, NewVD);
// If this is the first declaration of an extern C variable, update
// the map of such variables.
if (NewVD->isFirstDecl() && !NewVD->isInvalidDecl() &&
isIncompleteDeclExternC(*this, NewVD))
RegisterLocallyScopedExternCDecl(NewVD, S);
if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
MangleNumberingContext *MCtx;
Decl *ManglingContextDecl;
std::tie(MCtx, ManglingContextDecl) =
getCurrentMangleNumberContext(NewVD->getDeclContext());
if (MCtx) {
Context.setManglingNumber(
NewVD, MCtx->getManglingNumber(
NewVD, getMSManglingNumber(getLangOpts(), S)));
Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD));
}
}
// Special handling of variable named 'main'.
if (!getLangOpts().Freestanding && isMainVar(Name, NewVD)) {
// C++ [basic.start.main]p3:
// A program that declares
// - a variable main at global scope, or
// - an entity named main with C language linkage (in any namespace)
// is ill-formed
if (getLangOpts().CPlusPlus)
Diag(D.getBeginLoc(), diag::err_main_global_variable)
<< NewVD->isExternC();
// In C, and external-linkage variable named main results in undefined
// behavior.
else if (NewVD->hasExternalFormalLinkage())
Diag(D.getBeginLoc(), diag::warn_main_redefined);
}
if (D.isRedeclaration() && !Previous.empty()) {
NamedDecl *Prev = Previous.getRepresentativeDecl();
checkDLLAttributeRedeclaration(*this, Prev, NewVD, IsMemberSpecialization,
D.isFunctionDefinition());
}
if (NewTemplate) {
if (NewVD->isInvalidDecl())
NewTemplate->setInvalidDecl();
ActOnDocumentableDecl(NewTemplate);
return NewTemplate;
}
if (IsMemberSpecialization && !NewVD->isInvalidDecl())
CompleteMemberSpecialization(NewVD, Previous);
emitReadOnlyPlacementAttrWarning(*this, NewVD);
return NewVD;
}
/// Enum describing the %select options in diag::warn_decl_shadow.
enum ShadowedDeclKind {
SDK_Local,
SDK_Global,
SDK_StaticMember,
SDK_Field,
SDK_Typedef,
SDK_Using,
SDK_StructuredBinding
};
/// Determine what kind of declaration we're shadowing.
static ShadowedDeclKind computeShadowedDeclKind(const NamedDecl *ShadowedDecl,
const DeclContext *OldDC) {
if (isa<TypeAliasDecl>(ShadowedDecl))
return SDK_Using;
else if (isa<TypedefDecl>(ShadowedDecl))
return SDK_Typedef;
else if (isa<BindingDecl>(ShadowedDecl))
return SDK_StructuredBinding;
else if (isa<RecordDecl>(OldDC))
return isa<FieldDecl>(ShadowedDecl) ? SDK_Field : SDK_StaticMember;
return OldDC->isFileContext() ? SDK_Global : SDK_Local;
}
/// Return the location of the capture if the given lambda captures the given
/// variable \p VD, or an invalid source location otherwise.
static SourceLocation getCaptureLocation(const LambdaScopeInfo *LSI,
const VarDecl *VD) {
for (const Capture &Capture : LSI->Captures) {
if (Capture.isVariableCapture() && Capture.getVariable() == VD)
return Capture.getLocation();
}
return SourceLocation();
}
static bool shouldWarnIfShadowedDecl(const DiagnosticsEngine &Diags,
const LookupResult &R) {
// Only diagnose if we're shadowing an unambiguous field or variable.
if (R.getResultKind() != LookupResultKind::Found)
return false;
// Return false if warning is ignored.
return !Diags.isIgnored(diag::warn_decl_shadow, R.getNameLoc());
}
NamedDecl *Sema::getShadowedDeclaration(const VarDecl *D,
const LookupResult &R) {
if (!shouldWarnIfShadowedDecl(Diags, R))
return nullptr;
// Don't diagnose declarations at file scope.
if (D->hasGlobalStorage() && !D->isStaticLocal())
return nullptr;
NamedDecl *ShadowedDecl = R.getFoundDecl();
return isa<VarDecl, FieldDecl, BindingDecl>(ShadowedDecl) ? ShadowedDecl
: nullptr;
}
NamedDecl *Sema::getShadowedDeclaration(const TypedefNameDecl *D,
const LookupResult &R) {
// Don't warn if typedef declaration is part of a class
if (D->getDeclContext()->isRecord())
return nullptr;
if (!shouldWarnIfShadowedDecl(Diags, R))
return nullptr;
NamedDecl *ShadowedDecl = R.getFoundDecl();
return isa<TypedefNameDecl>(ShadowedDecl) ? ShadowedDecl : nullptr;
}
NamedDecl *Sema::getShadowedDeclaration(const BindingDecl *D,
const LookupResult &R) {
if (!shouldWarnIfShadowedDecl(Diags, R))
return nullptr;
NamedDecl *ShadowedDecl = R.getFoundDecl();
return isa<VarDecl, FieldDecl, BindingDecl>(ShadowedDecl) ? ShadowedDecl
: nullptr;
}
void Sema::CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl,
const LookupResult &R) {
DeclContext *NewDC = D->getDeclContext();
if (FieldDecl *FD = dyn_cast<FieldDecl>(ShadowedDecl)) {
if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewDC)) {
// Fields are not shadowed by variables in C++ static methods.
if (MD->isStatic())
return;
if (!MD->getParent()->isLambda() && MD->isExplicitObjectMemberFunction())
return;
}
// Fields shadowed by constructor parameters are a special case. Usually
// the constructor initializes the field with the parameter.
if (isa<CXXConstructorDecl>(NewDC))
if (const auto PVD = dyn_cast<ParmVarDecl>(D)) {
// Remember that this was shadowed so we can either warn about its
// modification or its existence depending on warning settings.
ShadowingDecls.insert({PVD->getCanonicalDecl(), FD});
return;
}
}
if (VarDecl *shadowedVar = dyn_cast<VarDecl>(ShadowedDecl))
if (shadowedVar->isExternC()) {
// For shadowing external vars, make sure that we point to the global
// declaration, not a locally scoped extern declaration.
for (auto *I : shadowedVar->redecls())
if (I->isFileVarDecl()) {
ShadowedDecl = I;
break;
}
}
DeclContext *OldDC = ShadowedDecl->getDeclContext()->getRedeclContext();
unsigned WarningDiag = diag::warn_decl_shadow;
SourceLocation CaptureLoc;
if (isa<VarDecl>(D) && NewDC && isa<CXXMethodDecl>(NewDC)) {
if (const auto *RD = dyn_cast<CXXRecordDecl>(NewDC->getParent())) {
if (RD->isLambda() && OldDC->Encloses(NewDC->getLexicalParent())) {
if (const auto *VD = dyn_cast<VarDecl>(ShadowedDecl)) {
const auto *LSI = cast<LambdaScopeInfo>(getCurFunction());
if (RD->getLambdaCaptureDefault() == LCD_None) {
// Try to avoid warnings for lambdas with an explicit capture
// list. Warn only when the lambda captures the shadowed decl
// explicitly.
CaptureLoc = getCaptureLocation(LSI, VD);
if (CaptureLoc.isInvalid())
WarningDiag = diag::warn_decl_shadow_uncaptured_local;
} else {
// Remember that this was shadowed so we can avoid the warning if
// the shadowed decl isn't captured and the warning settings allow
// it.
cast<LambdaScopeInfo>(getCurFunction())
->ShadowingDecls.push_back({D, VD});
return;
}
}
if (isa<FieldDecl>(ShadowedDecl)) {
// If lambda can capture this, then emit default shadowing warning,
// Otherwise it is not really a shadowing case since field is not
// available in lambda's body.
// At this point we don't know that lambda can capture this, so
// remember that this was shadowed and delay until we know.
cast<LambdaScopeInfo>(getCurFunction())
->ShadowingDecls.push_back({D, ShadowedDecl});
return;
}
}
if (const auto *VD = dyn_cast<VarDecl>(ShadowedDecl);
VD && VD->hasLocalStorage()) {
// A variable can't shadow a local variable in an enclosing scope, if
// they are separated by a non-capturing declaration context.
for (DeclContext *ParentDC = NewDC;
ParentDC && !ParentDC->Equals(OldDC);
ParentDC = getLambdaAwareParentOfDeclContext(ParentDC)) {
// Only block literals, captured statements, and lambda expressions
// can capture; other scopes don't.
if (!isa<BlockDecl>(ParentDC) && !isa<CapturedDecl>(ParentDC) &&
!isLambdaCallOperator(ParentDC)) {
return;
}
}
}
}
}
// Never warn about shadowing a placeholder variable.
if (ShadowedDecl->isPlaceholderVar(getLangOpts()))
return;
// Only warn about certain kinds of shadowing for class members.
if (NewDC) {
// In particular, don't warn about shadowing non-class members.
if (NewDC->isRecord() && !OldDC->isRecord())
return;
// Skip shadowing check if we're in a class scope, dealing with an enum
// constant in a different context.
DeclContext *ReDC = NewDC->getRedeclContext();
if (ReDC->isRecord() && isa<EnumConstantDecl>(D) && !OldDC->Equals(ReDC))
return;
// TODO: should we warn about static data members shadowing
// static data members from base classes?
// TODO: don't diagnose for inaccessible shadowed members.
// This is hard to do perfectly because we might friend the
// shadowing context, but that's just a false negative.
}
DeclarationName Name = R.getLookupName();
// Emit warning and note.
ShadowedDeclKind Kind = computeShadowedDeclKind(ShadowedDecl, OldDC);
Diag(R.getNameLoc(), WarningDiag) << Name << Kind << OldDC;
if (!CaptureLoc.isInvalid())
Diag(CaptureLoc, diag::note_var_explicitly_captured_here)
<< Name << /*explicitly*/ 1;
Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration);
}
void Sema::DiagnoseShadowingLambdaDecls(const LambdaScopeInfo *LSI) {
for (const auto &Shadow : LSI->ShadowingDecls) {
const NamedDecl *ShadowedDecl = Shadow.ShadowedDecl;
// Try to avoid the warning when the shadowed decl isn't captured.
const DeclContext *OldDC = ShadowedDecl->getDeclContext();
if (const auto *VD = dyn_cast<VarDecl>(ShadowedDecl)) {
SourceLocation CaptureLoc = getCaptureLocation(LSI, VD);
Diag(Shadow.VD->getLocation(),
CaptureLoc.isInvalid() ? diag::warn_decl_shadow_uncaptured_local
: diag::warn_decl_shadow)
<< Shadow.VD->getDeclName()
<< computeShadowedDeclKind(ShadowedDecl, OldDC) << OldDC;
if (CaptureLoc.isValid())
Diag(CaptureLoc, diag::note_var_explicitly_captured_here)
<< Shadow.VD->getDeclName() << /*explicitly*/ 0;
Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration);
} else if (isa<FieldDecl>(ShadowedDecl)) {
Diag(Shadow.VD->getLocation(),
LSI->isCXXThisCaptured() ? diag::warn_decl_shadow
: diag::warn_decl_shadow_uncaptured_local)
<< Shadow.VD->getDeclName()
<< computeShadowedDeclKind(ShadowedDecl, OldDC) << OldDC;
Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration);
}
}
}
void Sema::CheckShadow(Scope *S, VarDecl *D) {
if (Diags.isIgnored(diag::warn_decl_shadow, D->getLocation()))
return;
LookupResult R(*this, D->getDeclName(), D->getLocation(),
Sema::LookupOrdinaryName,
RedeclarationKind::ForVisibleRedeclaration);
LookupName(R, S);
if (NamedDecl *ShadowedDecl = getShadowedDeclaration(D, R))
CheckShadow(D, ShadowedDecl, R);
}
/// Check if 'E', which is an expression that is about to be modified, refers
/// to a constructor parameter that shadows a field.
void Sema::CheckShadowingDeclModification(Expr *E, SourceLocation Loc) {
// Quickly ignore expressions that can't be shadowing ctor parameters.
if (!getLangOpts().CPlusPlus || ShadowingDecls.empty())
return;
E = E->IgnoreParenImpCasts();
auto *DRE = dyn_cast<DeclRefExpr>(E);
if (!DRE)
return;
const NamedDecl *D = cast<NamedDecl>(DRE->getDecl()->getCanonicalDecl());
auto I = ShadowingDecls.find(D);
if (I == ShadowingDecls.end())
return;
const NamedDecl *ShadowedDecl = I->second;
const DeclContext *OldDC = ShadowedDecl->getDeclContext();
Diag(Loc, diag::warn_modifying_shadowing_decl) << D << OldDC;
Diag(D->getLocation(), diag::note_var_declared_here) << D;
Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration);
// Avoid issuing multiple warnings about the same decl.
ShadowingDecls.erase(I);
}
/// Check for conflict between this global or extern "C" declaration and
/// previous global or extern "C" declarations. This is only used in C++.
template<typename T>
static bool checkGlobalOrExternCConflict(
Sema &S, const T *ND, bool IsGlobal, LookupResult &Previous) {
assert(S.getLangOpts().CPlusPlus && "only C++ has extern \"C\"");
NamedDecl *Prev = S.findLocallyScopedExternCDecl(ND->getDeclName());
if (!Prev && IsGlobal && !isIncompleteDeclExternC(S, ND)) {
// The common case: this global doesn't conflict with any extern "C"
// declaration.
return false;
}
if (Prev) {
if (!IsGlobal || isIncompleteDeclExternC(S, ND)) {
// Both the old and new declarations have C language linkage. This is a
// redeclaration.
Previous.clear();
Previous.addDecl(Prev);
return true;
}
// This is a global, non-extern "C" declaration, and there is a previous
// non-global extern "C" declaration. Diagnose if this is a variable
// declaration.
if (!isa<VarDecl>(ND))
return false;
} else {
// The declaration is extern "C". Check for any declaration in the
// translation unit which might conflict.
if (IsGlobal) {
// We have already performed the lookup into the translation unit.
IsGlobal = false;
for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
I != E; ++I) {
if (isa<VarDecl>(*I)) {
Prev = *I;
break;
}
}
} else {
DeclContext::lookup_result R =
S.Context.getTranslationUnitDecl()->lookup(ND->getDeclName());
for (DeclContext::lookup_result::iterator I = R.begin(), E = R.end();
I != E; ++I) {
if (isa<VarDecl>(*I)) {
Prev = *I;
break;
}
// FIXME: If we have any other entity with this name in global scope,
// the declaration is ill-formed, but that is a defect: it breaks the
// 'stat' hack, for instance. Only variables can have mangled name
// clashes with extern "C" declarations, so only they deserve a
// diagnostic.
}
}
if (!Prev)
return false;
}
// Use the first declaration's location to ensure we point at something which
// is lexically inside an extern "C" linkage-spec.
assert(Prev && "should have found a previous declaration to diagnose");
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Prev))
Prev = FD->getFirstDecl();
else
Prev = cast<VarDecl>(Prev)->getFirstDecl();
S.Diag(ND->getLocation(), diag::err_extern_c_global_conflict)
<< IsGlobal << ND;
S.Diag(Prev->getLocation(), diag::note_extern_c_global_conflict)
<< IsGlobal;
return false;
}
/// Apply special rules for handling extern "C" declarations. Returns \c true
/// if we have found that this is a redeclaration of some prior entity.
///
/// Per C++ [dcl.link]p6:
/// Two declarations [for a function or variable] with C language linkage
/// with the same name that appear in different scopes refer to the same
/// [entity]. An entity with C language linkage shall not be declared with
/// the same name as an entity in global scope.
template<typename T>
static bool checkForConflictWithNonVisibleExternC(Sema &S, const T *ND,
LookupResult &Previous) {
if (!S.getLangOpts().CPlusPlus) {
// In C, when declaring a global variable, look for a corresponding 'extern'
// variable declared in function scope. We don't need this in C++, because
// we find local extern decls in the surrounding file-scope DeclContext.
if (ND->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
if (NamedDecl *Prev = S.findLocallyScopedExternCDecl(ND->getDeclName())) {
Previous.clear();
Previous.addDecl(Prev);
return true;
}
}
return false;
}
// A declaration in the translation unit can conflict with an extern "C"
// declaration.
if (ND->getDeclContext()->getRedeclContext()->isTranslationUnit())
return checkGlobalOrExternCConflict(S, ND, /*IsGlobal*/true, Previous);
// An extern "C" declaration can conflict with a declaration in the
// translation unit or can be a redeclaration of an extern "C" declaration
// in another scope.
if (isIncompleteDeclExternC(S,ND))
return checkGlobalOrExternCConflict(S, ND, /*IsGlobal*/false, Previous);
// Neither global nor extern "C": nothing to do.
return false;
}
static bool CheckC23ConstexprVarType(Sema &SemaRef, SourceLocation VarLoc,
QualType T) {
QualType CanonT = SemaRef.Context.getCanonicalType(T);
// C23 6.7.1p5: An object declared with storage-class specifier constexpr or
// any of its members, even recursively, shall not have an atomic type, or a
// variably modified type, or a type that is volatile or restrict qualified.
if (CanonT->isVariablyModifiedType()) {
SemaRef.Diag(VarLoc, diag::err_c23_constexpr_invalid_type) << T;
return true;
}
// Arrays are qualified by their element type, so get the base type (this
// works on non-arrays as well).
CanonT = SemaRef.Context.getBaseElementType(CanonT);
if (CanonT->isAtomicType() || CanonT.isVolatileQualified() ||
CanonT.isRestrictQualified()) {
SemaRef.Diag(VarLoc, diag::err_c23_constexpr_invalid_type) << T;
return true;
}
if (CanonT->isRecordType()) {
const RecordDecl *RD = CanonT->getAsRecordDecl();
if (!RD->isInvalidDecl() &&
llvm::any_of(RD->fields(), [&SemaRef, VarLoc](const FieldDecl *F) {
return CheckC23ConstexprVarType(SemaRef, VarLoc, F->getType());
}))
return true;
}
return false;
}
void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
// If the decl is already known invalid, don't check it.
if (NewVD->isInvalidDecl())
return;
QualType T = NewVD->getType();
// Defer checking an 'auto' type until its initializer is attached.
if (T->isUndeducedType())
return;
if (NewVD->hasAttrs())
CheckAlignasUnderalignment(NewVD);
if (T->isObjCObjectType()) {
Diag(NewVD->getLocation(), diag::err_statically_allocated_object)
<< FixItHint::CreateInsertion(NewVD->getLocation(), "*");
T = Context.getObjCObjectPointerType(T);
NewVD->setType(T);
}
// Emit an error if an address space was applied to decl with local storage.
// This includes arrays of objects with address space qualifiers, but not
// automatic variables that point to other address spaces.
// ISO/IEC TR 18037 S5.1.2
if (!getLangOpts().OpenCL && NewVD->hasLocalStorage() &&
T.getAddressSpace() != LangAS::Default) {
Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl) << 0;
NewVD->setInvalidDecl();
return;
}
// OpenCL v1.2 s6.8 - The static qualifier is valid only in program
// scope.
if (getLangOpts().OpenCLVersion == 120 &&
!getOpenCLOptions().isAvailableOption("cl_clang_storage_class_specifiers",
getLangOpts()) &&
NewVD->isStaticLocal()) {
Diag(NewVD->getLocation(), diag::err_static_function_scope);
NewVD->setInvalidDecl();
return;
}
if (getLangOpts().OpenCL) {
if (!diagnoseOpenCLTypes(*this, NewVD))
return;
// OpenCL v2.0 s6.12.5 - The __block storage type is not supported.
if (NewVD->hasAttr<BlocksAttr>()) {
Diag(NewVD->getLocation(), diag::err_opencl_block_storage_type);
return;
}
if (T->isBlockPointerType()) {
// OpenCL v2.0 s6.12.5 - Any block declaration must be const qualified and
// can't use 'extern' storage class.
if (!T.isConstQualified()) {
Diag(NewVD->getLocation(), diag::err_opencl_invalid_block_declaration)
<< 0 /*const*/;
NewVD->setInvalidDecl();
return;
}
if (NewVD->hasExternalStorage()) {
Diag(NewVD->getLocation(), diag::err_opencl_extern_block_declaration);
NewVD->setInvalidDecl();
return;
}
}
// FIXME: Adding local AS in C++ for OpenCL might make sense.
if (NewVD->isFileVarDecl() || NewVD->isStaticLocal() ||
NewVD->hasExternalStorage()) {
if (!T->isSamplerT() && !T->isDependentType() &&
!(T.getAddressSpace() == LangAS::opencl_constant ||
(T.getAddressSpace() == LangAS::opencl_global &&
getOpenCLOptions().areProgramScopeVariablesSupported(
getLangOpts())))) {
int Scope = NewVD->isStaticLocal() | NewVD->hasExternalStorage() << 1;
if (getOpenCLOptions().areProgramScopeVariablesSupported(getLangOpts()))
Diag(NewVD->getLocation(), diag::err_opencl_global_invalid_addr_space)
<< Scope << "global or constant";
else
Diag(NewVD->getLocation(), diag::err_opencl_global_invalid_addr_space)
<< Scope << "constant";
NewVD->setInvalidDecl();
return;
}
} else {
if (T.getAddressSpace() == LangAS::opencl_global) {
Diag(NewVD->getLocation(), diag::err_opencl_function_variable)
<< 1 /*is any function*/ << "global";
NewVD->setInvalidDecl();
return;
}
if (T.getAddressSpace() == LangAS::opencl_constant ||
T.getAddressSpace() == LangAS::opencl_local) {
FunctionDecl *FD = getCurFunctionDecl();
// OpenCL v1.1 s6.5.2 and s6.5.3: no local or constant variables
// in functions.
if (FD && !FD->hasAttr<DeviceKernelAttr>()) {
if (T.getAddressSpace() == LangAS::opencl_constant)
Diag(NewVD->getLocation(), diag::err_opencl_function_variable)
<< 0 /*non-kernel only*/ << "constant";
else
Diag(NewVD->getLocation(), diag::err_opencl_function_variable)
<< 0 /*non-kernel only*/ << "local";
NewVD->setInvalidDecl();
return;
}
// OpenCL v2.0 s6.5.2 and s6.5.3: local and constant variables must be
// in the outermost scope of a kernel function.
if (FD && FD->hasAttr<DeviceKernelAttr>()) {
if (!getCurScope()->isFunctionScope()) {
if (T.getAddressSpace() == LangAS::opencl_constant)
Diag(NewVD->getLocation(), diag::err_opencl_addrspace_scope)
<< "constant";
else
Diag(NewVD->getLocation(), diag::err_opencl_addrspace_scope)
<< "local";
NewVD->setInvalidDecl();
return;
}
}
} else if (T.getAddressSpace() != LangAS::opencl_private &&
// If we are parsing a template we didn't deduce an addr
// space yet.
T.getAddressSpace() != LangAS::Default) {
// Do not allow other address spaces on automatic variable.
Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl) << 1;
NewVD->setInvalidDecl();
return;
}
}
}
if (NewVD->hasLocalStorage() && T.isObjCGCWeak()
&& !NewVD->hasAttr<BlocksAttr>()) {
if (getLangOpts().getGC() != LangOptions::NonGC)
Diag(NewVD->getLocation(), diag::warn_gc_attribute_weak_on_local);
else {
assert(!getLangOpts().ObjCAutoRefCount);
Diag(NewVD->getLocation(), diag::warn_attribute_weak_on_local);
}
}
// WebAssembly tables must be static with a zero length and can't be
// declared within functions.
if (T->isWebAssemblyTableType()) {
if (getCurScope()->getParent()) { // Parent is null at top-level
Diag(NewVD->getLocation(), diag::err_wasm_table_in_function);
NewVD->setInvalidDecl();
return;
}
if (NewVD->getStorageClass() != SC_Static) {
Diag(NewVD->getLocation(), diag::err_wasm_table_must_be_static);
NewVD->setInvalidDecl();
return;
}
const auto *ATy = dyn_cast<ConstantArrayType>(T.getTypePtr());
if (!ATy || ATy->getZExtSize() != 0) {
Diag(NewVD->getLocation(),
diag::err_typecheck_wasm_table_must_have_zero_length);
NewVD->setInvalidDecl();
return;
}
}
// zero sized static arrays are not allowed in HIP device functions
if (getLangOpts().HIP && LangOpts.CUDAIsDevice) {
if (FunctionDecl *FD = getCurFunctionDecl();
FD &&
(FD->hasAttr<CUDADeviceAttr>() || FD->hasAttr<CUDAGlobalAttr>())) {
if (const ConstantArrayType *ArrayT =
getASTContext().getAsConstantArrayType(T);
ArrayT && ArrayT->isZeroSize()) {
Diag(NewVD->getLocation(), diag::err_typecheck_zero_array_size) << 2;
}
}
}
bool isVM = T->isVariablyModifiedType();
if (isVM || NewVD->hasAttr<CleanupAttr>() ||
NewVD->hasAttr<BlocksAttr>())
setFunctionHasBranchProtectedScope();
if ((isVM && NewVD->hasLinkage()) ||
(T->isVariableArrayType() && NewVD->hasGlobalStorage())) {
bool SizeIsNegative;
llvm::APSInt Oversized;
TypeSourceInfo *FixedTInfo = TryToFixInvalidVariablyModifiedTypeSourceInfo(
NewVD->getTypeSourceInfo(), Context, SizeIsNegative, Oversized);
QualType FixedT;
if (FixedTInfo && T == NewVD->getTypeSourceInfo()->getType())
FixedT = FixedTInfo->getType();
else if (FixedTInfo) {
// Type and type-as-written are canonically different. We need to fix up
// both types separately.
FixedT = TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative,
Oversized);
}
if ((!FixedTInfo || FixedT.isNull()) && T->isVariableArrayType()) {
const VariableArrayType *VAT = Context.getAsVariableArrayType(T);
// FIXME: This won't give the correct result for
// int a[10][n];
SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange();
if (NewVD->isFileVarDecl())
Diag(NewVD->getLocation(), diag::err_vla_decl_in_file_scope)
<< SizeRange;
else if (NewVD->isStaticLocal())
Diag(NewVD->getLocation(), diag::err_vla_decl_has_static_storage)
<< SizeRange;
else
Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage)
<< SizeRange;
NewVD->setInvalidDecl();
return;
}
if (!FixedTInfo) {
if (NewVD->isFileVarDecl())
Diag(NewVD->getLocation(), diag::err_vm_decl_in_file_scope);
else
Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage);
NewVD->setInvalidDecl();
return;
}
Diag(NewVD->getLocation(), diag::ext_vla_folded_to_constant);
NewVD->setType(FixedT);
NewVD->setTypeSourceInfo(FixedTInfo);
}
if (T->isVoidType()) {
// C++98 [dcl.stc]p5: The extern specifier can be applied only to the names
// of objects and functions.
if (NewVD->isThisDeclarationADefinition() || getLangOpts().CPlusPlus) {
Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type)
<< T;
NewVD->setInvalidDecl();
return;
}
}
if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) {
Diag(NewVD->getLocation(), diag::err_block_on_nonlocal);
NewVD->setInvalidDecl();
return;
}
if (!NewVD->hasLocalStorage() && T->isSizelessType() &&
!T.isWebAssemblyReferenceType() && !T->isHLSLSpecificType()) {
Diag(NewVD->getLocation(), diag::err_sizeless_nonlocal) << T;
NewVD->setInvalidDecl();
return;
}
if (isVM && NewVD->hasAttr<BlocksAttr>()) {
Diag(NewVD->getLocation(), diag::err_block_on_vm);
NewVD->setInvalidDecl();
return;
}
if (getLangOpts().C23 && NewVD->isConstexpr() &&
CheckC23ConstexprVarType(*this, NewVD->getLocation(), T)) {
NewVD->setInvalidDecl();
return;
}
if (getLangOpts().CPlusPlus && NewVD->isConstexpr() &&
!T->isDependentType() &&
RequireLiteralType(NewVD->getLocation(), T,
diag::err_constexpr_var_non_literal)) {
NewVD->setInvalidDecl();
return;
}
// PPC MMA non-pointer types are not allowed as non-local variable types.
if (Context.getTargetInfo().getTriple().isPPC64() &&
!NewVD->isLocalVarDecl() &&
PPC().CheckPPCMMAType(T, NewVD->getLocation())) {
NewVD->setInvalidDecl();
return;
}
// Check that SVE types are only used in functions with SVE available.
if (T->isSVESizelessBuiltinType() && isa<FunctionDecl>(CurContext)) {
const FunctionDecl *FD = cast<FunctionDecl>(CurContext);
llvm::StringMap<bool> CallerFeatureMap;
Context.getFunctionFeatureMap(CallerFeatureMap, FD);
if (!Builtin::evaluateRequiredTargetFeatures("sve", CallerFeatureMap)) {
if (!Builtin::evaluateRequiredTargetFeatures("sme", CallerFeatureMap)) {
Diag(NewVD->getLocation(), diag::err_sve_vector_in_non_sve_target) << T;
NewVD->setInvalidDecl();
return;
} else if (!IsArmStreamingFunction(FD,
/*IncludeLocallyStreaming=*/true)) {
Diag(NewVD->getLocation(),
diag::err_sve_vector_in_non_streaming_function)
<< T;
NewVD->setInvalidDecl();
return;
}
}
}
if (T->isRVVSizelessBuiltinType() && isa<FunctionDecl>(CurContext)) {
const FunctionDecl *FD = cast<FunctionDecl>(CurContext);
llvm::StringMap<bool> CallerFeatureMap;
Context.getFunctionFeatureMap(CallerFeatureMap, FD);
RISCV().checkRVVTypeSupport(T, NewVD->getLocation(), cast<Decl>(CurContext),
CallerFeatureMap);
}
}
bool Sema::CheckVariableDeclaration(VarDecl *NewVD, LookupResult &Previous) {
CheckVariableDeclarationType(NewVD);
// If the decl is already known invalid, don't check it.
if (NewVD->isInvalidDecl())
return false;
// If we did not find anything by this name, look for a non-visible
// extern "C" declaration with the same name.
if (Previous.empty() &&
checkForConflictWithNonVisibleExternC(*this, NewVD, Previous))
Previous.setShadowed();
if (!Previous.empty()) {
MergeVarDecl(NewVD, Previous);
return true;
}
return false;
}
bool Sema::AddOverriddenMethods(CXXRecordDecl *DC, CXXMethodDecl *MD) {
llvm::SmallPtrSet<const CXXMethodDecl*, 4> Overridden;
// Look for methods in base classes that this method might override.
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false,
/*DetectVirtual=*/false);
auto VisitBase = [&] (const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
CXXRecordDecl *BaseRecord = Specifier->getType()->getAsCXXRecordDecl();
DeclarationName Name = MD->getDeclName();
if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
// We really want to find the base class destructor here.
Name = Context.DeclarationNames.getCXXDestructorName(
Context.getCanonicalTagType(BaseRecord));
}
for (NamedDecl *BaseND : BaseRecord->lookup(Name)) {
CXXMethodDecl *BaseMD =
dyn_cast<CXXMethodDecl>(BaseND->getCanonicalDecl());
if (!BaseMD || !BaseMD->isVirtual() ||
IsOverride(MD, BaseMD, /*UseMemberUsingDeclRules=*/false,
/*ConsiderCudaAttrs=*/true))
continue;
if (!CheckExplicitObjectOverride(MD, BaseMD))
continue;
if (Overridden.insert(BaseMD).second) {
MD->addOverriddenMethod(BaseMD);
CheckOverridingFunctionReturnType(MD, BaseMD);
CheckOverridingFunctionAttributes(MD, BaseMD);
CheckOverridingFunctionExceptionSpec(MD, BaseMD);
CheckIfOverriddenFunctionIsMarkedFinal(MD, BaseMD);
}
// A method can only override one function from each base class. We
// don't track indirectly overridden methods from bases of bases.
return true;
}
return false;
};
DC->lookupInBases(VisitBase, Paths);
return !Overridden.empty();
}
namespace {
// Struct for holding all of the extra arguments needed by
// DiagnoseInvalidRedeclaration to call Sema::ActOnFunctionDeclarator.
struct ActOnFDArgs {
Scope *S;
Declarator &D;
MultiTemplateParamsArg TemplateParamLists;
bool AddToScope;
};
} // end anonymous namespace
namespace {
// Callback to only accept typo corrections that have a non-zero edit distance.
// Also only accept corrections that have the same parent decl.
class DifferentNameValidatorCCC final : public CorrectionCandidateCallback {
public:
DifferentNameValidatorCCC(ASTContext &Context, FunctionDecl *TypoFD,
CXXRecordDecl *Parent)
: Context(Context), OriginalFD(TypoFD),
ExpectedParent(Parent ? Parent->getCanonicalDecl() : nullptr) {}
bool ValidateCandidate(const TypoCorrection &candidate) override {
if (candidate.getEditDistance() == 0)
return false;
SmallVector<unsigned, 1> MismatchedParams;
for (TypoCorrection::const_decl_iterator CDecl = candidate.begin(),
CDeclEnd = candidate.end();
CDecl != CDeclEnd; ++CDecl) {
FunctionDecl *FD = dyn_cast<FunctionDecl>(*CDecl);
if (FD && !FD->hasBody() &&
hasSimilarParameters(Context, FD, OriginalFD, MismatchedParams)) {
if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
CXXRecordDecl *Parent = MD->getParent();
if (Parent && Parent->getCanonicalDecl() == ExpectedParent)
return true;
} else if (!ExpectedParent) {
return true;
}
}
}
return false;
}
std::unique_ptr<CorrectionCandidateCallback> clone() override {
return std::make_unique<DifferentNameValidatorCCC>(*this);
}
private:
ASTContext &Context;
FunctionDecl *OriginalFD;
CXXRecordDecl *ExpectedParent;
};
} // end anonymous namespace
void Sema::MarkTypoCorrectedFunctionDefinition(const NamedDecl *F) {
TypoCorrectedFunctionDefinitions.insert(F);
}
/// Generate diagnostics for an invalid function redeclaration.
///
/// This routine handles generating the diagnostic messages for an invalid
/// function redeclaration, including finding possible similar declarations
/// or performing typo correction if there are no previous declarations with
/// the same name.
///
/// Returns a NamedDecl iff typo correction was performed and substituting in
/// the new declaration name does not cause new errors.
static NamedDecl *DiagnoseInvalidRedeclaration(
Sema &SemaRef, LookupResult &Previous, FunctionDecl *NewFD,
ActOnFDArgs &ExtraArgs, bool IsLocalFriend, Scope *S) {
DeclarationName Name = NewFD->getDeclName();
DeclContext *NewDC = NewFD->getDeclContext();
SmallVector<unsigned, 1> MismatchedParams;
SmallVector<std::pair<FunctionDecl *, unsigned>, 1> NearMatches;
TypoCorrection Correction;
bool IsDefinition = ExtraArgs.D.isFunctionDefinition();
unsigned DiagMsg =
IsLocalFriend ? diag::err_no_matching_local_friend :
NewFD->getFriendObjectKind() ? diag::err_qualified_friend_no_match :
diag::err_member_decl_does_not_match;
LookupResult Prev(SemaRef, Name, NewFD->getLocation(),
IsLocalFriend ? Sema::LookupLocalFriendName
: Sema::LookupOrdinaryName,
RedeclarationKind::ForVisibleRedeclaration);
NewFD->setInvalidDecl();
if (IsLocalFriend)
SemaRef.LookupName(Prev, S);
else
SemaRef.LookupQualifiedName(Prev, NewDC);
assert(!Prev.isAmbiguous() &&
"Cannot have an ambiguity in previous-declaration lookup");
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
DifferentNameValidatorCCC CCC(SemaRef.Context, NewFD,
MD ? MD->getParent() : nullptr);
if (!Prev.empty()) {
for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end();
Func != FuncEnd; ++Func) {
FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func);
if (FD &&
hasSimilarParameters(SemaRef.Context, FD, NewFD, MismatchedParams)) {
// Add 1 to the index so that 0 can mean the mismatch didn't
// involve a parameter
unsigned ParamNum =
MismatchedParams.empty() ? 0 : MismatchedParams.front() + 1;
NearMatches.push_back(std::make_pair(FD, ParamNum));
}
}
// If the qualified name lookup yielded nothing, try typo correction
} else if ((Correction = SemaRef.CorrectTypo(
Prev.getLookupNameInfo(), Prev.getLookupKind(), S,
&ExtraArgs.D.getCXXScopeSpec(), CCC,
CorrectTypoKind::ErrorRecovery,
IsLocalFriend ? nullptr : NewDC))) {
// Set up everything for the call to ActOnFunctionDeclarator
ExtraArgs.D.SetIdentifier(Correction.getCorrectionAsIdentifierInfo(),
ExtraArgs.D.getIdentifierLoc());
Previous.clear();
Previous.setLookupName(Correction.getCorrection());
for (TypoCorrection::decl_iterator CDecl = Correction.begin(),
CDeclEnd = Correction.end();
CDecl != CDeclEnd; ++CDecl) {
FunctionDecl *FD = dyn_cast<FunctionDecl>(*CDecl);
if (FD && !FD->hasBody() &&
hasSimilarParameters(SemaRef.Context, FD, NewFD, MismatchedParams)) {
Previous.addDecl(FD);
}
}
bool wasRedeclaration = ExtraArgs.D.isRedeclaration();
NamedDecl *Result;
// Retry building the function declaration with the new previous
// declarations, and with errors suppressed.
{
// Trap errors.
Sema::SFINAETrap Trap(SemaRef);
// TODO: Refactor ActOnFunctionDeclarator so that we can call only the
// pieces need to verify the typo-corrected C++ declaration and hopefully
// eliminate the need for the parameter pack ExtraArgs.
Result = SemaRef.ActOnFunctionDeclarator(
ExtraArgs.S, ExtraArgs.D,
Correction.getCorrectionDecl()->getDeclContext(),
NewFD->getTypeSourceInfo(), Previous, ExtraArgs.TemplateParamLists,
ExtraArgs.AddToScope);
if (Trap.hasErrorOccurred())
Result = nullptr;
}
if (Result) {
// Determine which correction we picked.
Decl *Canonical = Result->getCanonicalDecl();
for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
I != E; ++I)
if ((*I)->getCanonicalDecl() == Canonical)
Correction.setCorrectionDecl(*I);
// Let Sema know about the correction.
SemaRef.MarkTypoCorrectedFunctionDefinition(Result);
SemaRef.diagnoseTypo(
Correction,
SemaRef.PDiag(IsLocalFriend
? diag::err_no_matching_local_friend_suggest
: diag::err_member_decl_does_not_match_suggest)
<< Name << NewDC << IsDefinition);
return Result;
}
// Pretend the typo correction never occurred
ExtraArgs.D.SetIdentifier(Name.getAsIdentifierInfo(),
ExtraArgs.D.getIdentifierLoc());
ExtraArgs.D.setRedeclaration(wasRedeclaration);
Previous.clear();
Previous.setLookupName(Name);
}
SemaRef.Diag(NewFD->getLocation(), DiagMsg)
<< Name << NewDC << IsDefinition << NewFD->getLocation();
CXXMethodDecl *NewMD = dyn_cast<CXXMethodDecl>(NewFD);
if (NewMD && DiagMsg == diag::err_member_decl_does_not_match) {
CXXRecordDecl *RD = NewMD->getParent();
SemaRef.Diag(RD->getLocation(), diag::note_defined_here)
<< RD->getName() << RD->getLocation();
}
bool NewFDisConst = NewMD && NewMD->isConst();
for (SmallVectorImpl<std::pair<FunctionDecl *, unsigned> >::iterator
NearMatch = NearMatches.begin(), NearMatchEnd = NearMatches.end();
NearMatch != NearMatchEnd; ++NearMatch) {
FunctionDecl *FD = NearMatch->first;
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
bool FDisConst = MD && MD->isConst();
bool IsMember = MD || !IsLocalFriend;
// FIXME: These notes are poorly worded for the local friend case.
if (unsigned Idx = NearMatch->second) {
ParmVarDecl *FDParam = FD->getParamDecl(Idx-1);
SourceLocation Loc = FDParam->getTypeSpecStartLoc();
if (Loc.isInvalid()) Loc = FD->getLocation();
SemaRef.Diag(Loc, IsMember ? diag::note_member_def_close_param_match
: diag::note_local_decl_close_param_match)
<< Idx << FDParam->getType()
<< NewFD->getParamDecl(Idx - 1)->getType();
} else if (FDisConst != NewFDisConst) {
auto DB = SemaRef.Diag(FD->getLocation(),
diag::note_member_def_close_const_match)
<< NewFDisConst << FD->getSourceRange().getEnd();
if (const auto &FTI = ExtraArgs.D.getFunctionTypeInfo(); !NewFDisConst)
DB << FixItHint::CreateInsertion(FTI.getRParenLoc().getLocWithOffset(1),
" const");
else if (FTI.hasMethodTypeQualifiers() &&
FTI.getConstQualifierLoc().isValid())
DB << FixItHint::CreateRemoval(FTI.getConstQualifierLoc());
} else {
SemaRef.Diag(FD->getLocation(),
IsMember ? diag::note_member_def_close_match
: diag::note_local_decl_close_match);
}
}
return nullptr;
}
static StorageClass getFunctionStorageClass(Sema &SemaRef, Declarator &D) {
switch (D.getDeclSpec().getStorageClassSpec()) {
default: llvm_unreachable("Unknown storage class!");
case DeclSpec::SCS_auto:
case DeclSpec::SCS_register:
case DeclSpec::SCS_mutable:
SemaRef.Diag(D.getDeclSpec().getStorageClassSpecLoc(),
diag::err_typecheck_sclass_func);
D.getMutableDeclSpec().ClearStorageClassSpecs();
D.setInvalidType();
break;
case DeclSpec::SCS_unspecified: break;
case DeclSpec::SCS_extern:
if (D.getDeclSpec().isExternInLinkageSpec())
return SC_None;
return SC_Extern;
case DeclSpec::SCS_static: {
if (SemaRef.CurContext->getRedeclContext()->isFunctionOrMethod()) {
// C99 6.7.1p5:
// The declaration of an identifier for a function that has
// block scope shall have no explicit storage-class specifier
// other than extern
// See also (C++ [dcl.stc]p4).
SemaRef.Diag(D.getDeclSpec().getStorageClassSpecLoc(),
diag::err_static_block_func);
break;
} else
return SC_Static;
}
case DeclSpec::SCS_private_extern: return SC_PrivateExtern;
}
// No explicit storage class has already been returned
return SC_None;
}
static FunctionDecl *CreateNewFunctionDecl(Sema &SemaRef, Declarator &D,
DeclContext *DC, QualType &R,
TypeSourceInfo *TInfo,
StorageClass SC,
bool &IsVirtualOkay) {
DeclarationNameInfo NameInfo = SemaRef.GetNameForDeclarator(D);
DeclarationName Name = NameInfo.getName();
FunctionDecl *NewFD = nullptr;
bool isInline = D.getDeclSpec().isInlineSpecified();
ConstexprSpecKind ConstexprKind = D.getDeclSpec().getConstexprSpecifier();
if (ConstexprKind == ConstexprSpecKind::Constinit ||
(SemaRef.getLangOpts().C23 &&
ConstexprKind == ConstexprSpecKind::Constexpr)) {
if (SemaRef.getLangOpts().C23)
SemaRef.Diag(D.getDeclSpec().getConstexprSpecLoc(),
diag::err_c23_constexpr_not_variable);
else
SemaRef.Diag(D.getDeclSpec().getConstexprSpecLoc(),
diag::err_constexpr_wrong_decl_kind)
<< static_cast<int>(ConstexprKind);
ConstexprKind = ConstexprSpecKind::Unspecified;
D.getMutableDeclSpec().ClearConstexprSpec();
}
if (!SemaRef.getLangOpts().CPlusPlus) {
// Determine whether the function was written with a prototype. This is
// true when:
// - there is a prototype in the declarator, or
// - the type R of the function is some kind of typedef or other non-
// attributed reference to a type name (which eventually refers to a
// function type). Note, we can't always look at the adjusted type to
// check this case because attributes may cause a non-function
// declarator to still have a function type. e.g.,
// typedef void func(int a);
// __attribute__((noreturn)) func other_func; // This has a prototype
bool HasPrototype =
(D.isFunctionDeclarator() && D.getFunctionTypeInfo().hasPrototype) ||
(D.getDeclSpec().isTypeRep() &&
SemaRef.GetTypeFromParser(D.getDeclSpec().getRepAsType(), nullptr)
->isFunctionProtoType()) ||
(!R->getAsAdjusted<FunctionType>() && R->isFunctionProtoType());
assert(
(HasPrototype || !SemaRef.getLangOpts().requiresStrictPrototypes()) &&
"Strict prototypes are required");
NewFD = FunctionDecl::Create(
SemaRef.Context, DC, D.getBeginLoc(), NameInfo, R, TInfo, SC,
SemaRef.getCurFPFeatures().isFPConstrained(), isInline, HasPrototype,
ConstexprSpecKind::Unspecified,
/*TrailingRequiresClause=*/{});
if (D.isInvalidType())
NewFD->setInvalidDecl();
return NewFD;
}
ExplicitSpecifier ExplicitSpecifier = D.getDeclSpec().getExplicitSpecifier();
AssociatedConstraint TrailingRequiresClause(D.getTrailingRequiresClause());
SemaRef.CheckExplicitObjectMemberFunction(DC, D, Name, R);
if (Name.getNameKind() == DeclarationName::CXXConstructorName) {
// This is a C++ constructor declaration.
assert(DC->isRecord() &&
"Constructors can only be declared in a member context");
R = SemaRef.CheckConstructorDeclarator(D, R, SC);
return CXXConstructorDecl::Create(
SemaRef.Context, cast<CXXRecordDecl>(DC), D.getBeginLoc(), NameInfo, R,
TInfo, ExplicitSpecifier, SemaRef.getCurFPFeatures().isFPConstrained(),
isInline, /*isImplicitlyDeclared=*/false, ConstexprKind,
InheritedConstructor(), TrailingRequiresClause);
} else if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
// This is a C++ destructor declaration.
if (DC->isRecord()) {
R = SemaRef.CheckDestructorDeclarator(D, R, SC);
CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
CXXDestructorDecl *NewDD = CXXDestructorDecl::Create(
SemaRef.Context, Record, D.getBeginLoc(), NameInfo, R, TInfo,
SemaRef.getCurFPFeatures().isFPConstrained(), isInline,
/*isImplicitlyDeclared=*/false, ConstexprKind,
TrailingRequiresClause);
// User defined destructors start as not selected if the class definition is still
// not done.
if (Record->isBeingDefined())
NewDD->setIneligibleOrNotSelected(true);
// If the destructor needs an implicit exception specification, set it
// now. FIXME: It'd be nice to be able to create the right type to start
// with, but the type needs to reference the destructor declaration.
if (SemaRef.getLangOpts().CPlusPlus11)
SemaRef.AdjustDestructorExceptionSpec(NewDD);
IsVirtualOkay = true;
return NewDD;
} else {
SemaRef.Diag(D.getIdentifierLoc(), diag::err_destructor_not_member);
D.setInvalidType();
// Create a FunctionDecl to satisfy the function definition parsing
// code path.
return FunctionDecl::Create(
SemaRef.Context, DC, D.getBeginLoc(), D.getIdentifierLoc(), Name, R,
TInfo, SC, SemaRef.getCurFPFeatures().isFPConstrained(), isInline,
/*hasPrototype=*/true, ConstexprKind, TrailingRequiresClause);
}
} else if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName) {
if (!DC->isRecord()) {
SemaRef.Diag(D.getIdentifierLoc(),
diag::err_conv_function_not_member);
return nullptr;
}
SemaRef.CheckConversionDeclarator(D, R, SC);
if (D.isInvalidType())
return nullptr;
IsVirtualOkay = true;
return CXXConversionDecl::Create(
SemaRef.Context, cast<CXXRecordDecl>(DC), D.getBeginLoc(), NameInfo, R,
TInfo, SemaRef.getCurFPFeatures().isFPConstrained(), isInline,
ExplicitSpecifier, ConstexprKind, SourceLocation(),
TrailingRequiresClause);
} else if (Name.getNameKind() == DeclarationName::CXXDeductionGuideName) {
if (SemaRef.CheckDeductionGuideDeclarator(D, R, SC))
return nullptr;
return CXXDeductionGuideDecl::Create(
SemaRef.Context, DC, D.getBeginLoc(), ExplicitSpecifier, NameInfo, R,
TInfo, D.getEndLoc(), /*Ctor=*/nullptr,
/*Kind=*/DeductionCandidate::Normal, TrailingRequiresClause);
} else if (DC->isRecord()) {
// If the name of the function is the same as the name of the record,
// then this must be an invalid constructor that has a return type.
// (The parser checks for a return type and makes the declarator a
// constructor if it has no return type).
if (Name.getAsIdentifierInfo() &&
Name.getAsIdentifierInfo() == cast<CXXRecordDecl>(DC)->getIdentifier()){
SemaRef.Diag(D.getIdentifierLoc(), diag::err_constructor_return_type)
<< SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
<< SourceRange(D.getIdentifierLoc());
return nullptr;
}
// This is a C++ method declaration.
CXXMethodDecl *Ret = CXXMethodDecl::Create(
SemaRef.Context, cast<CXXRecordDecl>(DC), D.getBeginLoc(), NameInfo, R,
TInfo, SC, SemaRef.getCurFPFeatures().isFPConstrained(), isInline,
ConstexprKind, SourceLocation(), TrailingRequiresClause);
IsVirtualOkay = !Ret->isStatic();
return Ret;
} else {
bool isFriend =
SemaRef.getLangOpts().CPlusPlus && D.getDeclSpec().isFriendSpecified();
if (!isFriend && SemaRef.CurContext->isRecord())
return nullptr;
// Determine whether the function was written with a
// prototype. This true when:
// - we're in C++ (where every function has a prototype),
return FunctionDecl::Create(
SemaRef.Context, DC, D.getBeginLoc(), NameInfo, R, TInfo, SC,
SemaRef.getCurFPFeatures().isFPConstrained(), isInline,
true /*HasPrototype*/, ConstexprKind, TrailingRequiresClause);
}
}
enum OpenCLParamType {
ValidKernelParam,
PtrPtrKernelParam,
PtrKernelParam,
InvalidAddrSpacePtrKernelParam,
InvalidKernelParam,
RecordKernelParam
};
static bool isOpenCLSizeDependentType(ASTContext &C, QualType Ty) {
// Size dependent types are just typedefs to normal integer types
// (e.g. unsigned long), so we cannot distinguish them from other typedefs to
// integers other than by their names.
StringRef SizeTypeNames[] = {"size_t", "intptr_t", "uintptr_t", "ptrdiff_t"};
// Remove typedefs one by one until we reach a typedef
// for a size dependent type.
QualType DesugaredTy = Ty;
do {
ArrayRef<StringRef> Names(SizeTypeNames);
auto Match = llvm::find(Names, DesugaredTy.getUnqualifiedType().getAsString());
if (Names.end() != Match)
return true;
Ty = DesugaredTy;
DesugaredTy = Ty.getSingleStepDesugaredType(C);
} while (DesugaredTy != Ty);
return false;
}
static OpenCLParamType getOpenCLKernelParameterType(Sema &S, QualType PT) {
if (PT->isDependentType())
return InvalidKernelParam;
if (PT->isPointerOrReferenceType()) {
QualType PointeeType = PT->getPointeeType();
if (PointeeType.getAddressSpace() == LangAS::opencl_generic ||
PointeeType.getAddressSpace() == LangAS::opencl_private ||
PointeeType.getAddressSpace() == LangAS::Default)
return InvalidAddrSpacePtrKernelParam;
if (PointeeType->isPointerType()) {
// This is a pointer to pointer parameter.
// Recursively check inner type.
OpenCLParamType ParamKind = getOpenCLKernelParameterType(S, PointeeType);
if (ParamKind == InvalidAddrSpacePtrKernelParam ||
ParamKind == InvalidKernelParam)
return ParamKind;
// OpenCL v3.0 s6.11.a:
// A restriction to pass pointers to pointers only applies to OpenCL C
// v1.2 or below.
if (S.getLangOpts().getOpenCLCompatibleVersion() > 120)
return ValidKernelParam;
return PtrPtrKernelParam;
}
// C++ for OpenCL v1.0 s2.4:
// Moreover the types used in parameters of the kernel functions must be:
// Standard layout types for pointer parameters. The same applies to
// reference if an implementation supports them in kernel parameters.
if (S.getLangOpts().OpenCLCPlusPlus &&
!S.getOpenCLOptions().isAvailableOption(
"__cl_clang_non_portable_kernel_param_types", S.getLangOpts())) {
auto CXXRec = PointeeType.getCanonicalType()->getAsCXXRecordDecl();
bool IsStandardLayoutType = true;
if (CXXRec) {
// If template type is not ODR-used its definition is only available
// in the template definition not its instantiation.
// FIXME: This logic doesn't work for types that depend on template
// parameter (PR58590).
if (!CXXRec->hasDefinition())
CXXRec = CXXRec->getTemplateInstantiationPattern();
if (!CXXRec || !CXXRec->hasDefinition() || !CXXRec->isStandardLayout())
IsStandardLayoutType = false;
}
if (!PointeeType->isAtomicType() && !PointeeType->isVoidType() &&
!IsStandardLayoutType)
return InvalidKernelParam;
}
// OpenCL v1.2 s6.9.p:
// A restriction to pass pointers only applies to OpenCL C v1.2 or below.
if (S.getLangOpts().getOpenCLCompatibleVersion() > 120)
return ValidKernelParam;
return PtrKernelParam;
}
// OpenCL v1.2 s6.9.k:
// Arguments to kernel functions in a program cannot be declared with the
// built-in scalar types bool, half, size_t, ptrdiff_t, intptr_t, and
// uintptr_t or a struct and/or union that contain fields declared to be one
// of these built-in scalar types.
if (isOpenCLSizeDependentType(S.getASTContext(), PT))
return InvalidKernelParam;
if (PT->isImageType())
return PtrKernelParam;
if (PT->isBooleanType() || PT->isEventT() || PT->isReserveIDT())
return InvalidKernelParam;
// OpenCL extension spec v1.2 s9.5:
// This extension adds support for half scalar and vector types as built-in
// types that can be used for arithmetic operations, conversions etc.
if (!S.getOpenCLOptions().isAvailableOption("cl_khr_fp16", S.getLangOpts()) &&
PT->isHalfType())
return InvalidKernelParam;
// Look into an array argument to check if it has a forbidden type.
if (PT->isArrayType()) {
const Type *UnderlyingTy = PT->getPointeeOrArrayElementType();
// Call ourself to check an underlying type of an array. Since the
// getPointeeOrArrayElementType returns an innermost type which is not an
// array, this recursive call only happens once.
return getOpenCLKernelParameterType(S, QualType(UnderlyingTy, 0));
}
// C++ for OpenCL v1.0 s2.4:
// Moreover the types used in parameters of the kernel functions must be:
// Trivial and standard-layout types C++17 [basic.types] (plain old data
// types) for parameters passed by value;
if (S.getLangOpts().OpenCLCPlusPlus &&
!S.getOpenCLOptions().isAvailableOption(
"__cl_clang_non_portable_kernel_param_types", S.getLangOpts()) &&
!PT->isOpenCLSpecificType() && !PT.isPODType(S.Context))
return InvalidKernelParam;
if (PT->isRecordType())
return RecordKernelParam;
return ValidKernelParam;
}
static void checkIsValidOpenCLKernelParameter(
Sema &S,
Declarator &D,
ParmVarDecl *Param,
llvm::SmallPtrSetImpl<const Type *> &ValidTypes) {
QualType PT = Param->getType();
// Cache the valid types we encounter to avoid rechecking structs that are
// used again
if (ValidTypes.count(PT.getTypePtr()))
return;
switch (getOpenCLKernelParameterType(S, PT)) {
case PtrPtrKernelParam:
// OpenCL v3.0 s6.11.a:
// A kernel function argument cannot be declared as a pointer to a pointer
// type. [...] This restriction only applies to OpenCL C 1.2 or below.
S.Diag(Param->getLocation(), diag::err_opencl_ptrptr_kernel_param);
D.setInvalidType();
return;
case InvalidAddrSpacePtrKernelParam:
// OpenCL v1.0 s6.5:
// __kernel function arguments declared to be a pointer of a type can point
// to one of the following address spaces only : __global, __local or
// __constant.
S.Diag(Param->getLocation(), diag::err_kernel_arg_address_space);
D.setInvalidType();
return;
// OpenCL v1.2 s6.9.k:
// Arguments to kernel functions in a program cannot be declared with the
// built-in scalar types bool, half, size_t, ptrdiff_t, intptr_t, and
// uintptr_t or a struct and/or union that contain fields declared to be
// one of these built-in scalar types.
case InvalidKernelParam:
// OpenCL v1.2 s6.8 n:
// A kernel function argument cannot be declared
// of event_t type.
// Do not diagnose half type since it is diagnosed as invalid argument
// type for any function elsewhere.
if (!PT->isHalfType()) {
S.Diag(Param->getLocation(), diag::err_bad_kernel_param_type) << PT;
// Explain what typedefs are involved.
const TypedefType *Typedef = nullptr;
while ((Typedef = PT->getAs<TypedefType>())) {
SourceLocation Loc = Typedef->getDecl()->getLocation();
// SourceLocation may be invalid for a built-in type.
if (Loc.isValid())
S.Diag(Loc, diag::note_entity_declared_at) << PT;
PT = Typedef->desugar();
}
}
D.setInvalidType();
return;
case PtrKernelParam:
case ValidKernelParam:
ValidTypes.insert(PT.getTypePtr());
return;
case RecordKernelParam:
break;
}
// Track nested structs we will inspect
SmallVector<const Decl *, 4> VisitStack;
// Track where we are in the nested structs. Items will migrate from
// VisitStack to HistoryStack as we do the DFS for bad field.
SmallVector<const FieldDecl *, 4> HistoryStack;
HistoryStack.push_back(nullptr);
// At this point we already handled everything except of a RecordType.
assert(PT->isRecordType() && "Unexpected type.");
const auto *PD = PT->castAsRecordDecl();
VisitStack.push_back(PD);
assert(VisitStack.back() && "First decl null?");
do {
const Decl *Next = VisitStack.pop_back_val();
if (!Next) {
assert(!HistoryStack.empty());
// Found a marker, we have gone up a level
if (const FieldDecl *Hist = HistoryStack.pop_back_val())
ValidTypes.insert(Hist->getType().getTypePtr());
continue;
}
// Adds everything except the original parameter declaration (which is not a
// field itself) to the history stack.
const RecordDecl *RD;
if (const FieldDecl *Field = dyn_cast<FieldDecl>(Next)) {
HistoryStack.push_back(Field);
QualType FieldTy = Field->getType();
// Other field types (known to be valid or invalid) are handled while we
// walk around RecordDecl::fields().
assert((FieldTy->isArrayType() || FieldTy->isRecordType()) &&
"Unexpected type.");
const Type *FieldRecTy = FieldTy->getPointeeOrArrayElementType();
RD = FieldRecTy->castAsRecordDecl();
} else {
RD = cast<RecordDecl>(Next);
}
// Add a null marker so we know when we've gone back up a level
VisitStack.push_back(nullptr);
for (const auto *FD : RD->fields()) {
QualType QT = FD->getType();
if (ValidTypes.count(QT.getTypePtr()))
continue;
OpenCLParamType ParamType = getOpenCLKernelParameterType(S, QT);
if (ParamType == ValidKernelParam)
continue;
if (ParamType == RecordKernelParam) {
VisitStack.push_back(FD);
continue;
}
// OpenCL v1.2 s6.9.p:
// Arguments to kernel functions that are declared to be a struct or union
// do not allow OpenCL objects to be passed as elements of the struct or
// union. This restriction was lifted in OpenCL v2.0 with the introduction
// of SVM.
if (ParamType == PtrKernelParam || ParamType == PtrPtrKernelParam ||
ParamType == InvalidAddrSpacePtrKernelParam) {
S.Diag(Param->getLocation(),
diag::err_record_with_pointers_kernel_param)
<< PT->isUnionType()
<< PT;
} else {
S.Diag(Param->getLocation(), diag::err_bad_kernel_param_type) << PT;
}
S.Diag(PD->getLocation(), diag::note_within_field_of_type)
<< PD->getDeclName();
// We have an error, now let's go back up through history and show where
// the offending field came from
for (ArrayRef<const FieldDecl *>::const_iterator
I = HistoryStack.begin() + 1,
E = HistoryStack.end();
I != E; ++I) {
const FieldDecl *OuterField = *I;
S.Diag(OuterField->getLocation(), diag::note_within_field_of_type)
<< OuterField->getType();
}
S.Diag(FD->getLocation(), diag::note_illegal_field_declared_here)
<< QT->isPointerType()
<< QT;
D.setInvalidType();
return;
}
} while (!VisitStack.empty());
}
/// Find the DeclContext in which a tag is implicitly declared if we see an
/// elaborated type specifier in the specified context, and lookup finds
/// nothing.
static DeclContext *getTagInjectionContext(DeclContext *DC) {
while (!DC->isFileContext() && !DC->isFunctionOrMethod())
DC = DC->getParent();
return DC;
}
/// Find the Scope in which a tag is implicitly declared if we see an
/// elaborated type specifier in the specified context, and lookup finds
/// nothing.
static Scope *getTagInjectionScope(Scope *S, const LangOptions &LangOpts) {
while (S->isClassScope() ||
(LangOpts.CPlusPlus &&
S->isFunctionPrototypeScope()) ||
((S->getFlags() & Scope::DeclScope) == 0) ||
(S->getEntity() && S->getEntity()->isTransparentContext()))
S = S->getParent();
return S;
}
/// Determine whether a declaration matches a known function in namespace std.
static bool isStdBuiltin(ASTContext &Ctx, FunctionDecl *FD,
unsigned BuiltinID) {
switch (BuiltinID) {
case Builtin::BI__GetExceptionInfo:
// No type checking whatsoever.
return Ctx.getTargetInfo().getCXXABI().isMicrosoft();
case Builtin::BIaddressof:
case Builtin::BI__addressof:
case Builtin::BIforward:
case Builtin::BIforward_like:
case Builtin::BImove:
case Builtin::BImove_if_noexcept:
case Builtin::BIas_const: {
// Ensure that we don't treat the algorithm
// OutputIt std::move(InputIt, InputIt, OutputIt)
// as the builtin std::move.
const auto *FPT = FD->getType()->castAs<FunctionProtoType>();
return FPT->getNumParams() == 1 && !FPT->isVariadic();
}
default:
return false;
}
}
NamedDecl*
Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
TypeSourceInfo *TInfo, LookupResult &Previous,
MultiTemplateParamsArg TemplateParamListsRef,
bool &AddToScope) {
QualType R = TInfo->getType();
assert(R->isFunctionType());
if (R.getCanonicalType()->castAs<FunctionType>()->getCmseNSCallAttr())
Diag(D.getIdentifierLoc(), diag::err_function_decl_cmse_ns_call);
SmallVector<TemplateParameterList *, 4> TemplateParamLists;
llvm::append_range(TemplateParamLists, TemplateParamListsRef);
if (TemplateParameterList *Invented = D.getInventedTemplateParameterList()) {
if (!TemplateParamLists.empty() && !TemplateParamLists.back()->empty() &&
Invented->getDepth() == TemplateParamLists.back()->getDepth())
TemplateParamLists.back() = Invented;
else
TemplateParamLists.push_back(Invented);
}
// TODO: consider using NameInfo for diagnostic.
DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
DeclarationName Name = NameInfo.getName();
StorageClass SC = getFunctionStorageClass(*this, D);
if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
diag::err_invalid_thread)
<< DeclSpec::getSpecifierName(TSCS);
if (D.isFirstDeclarationOfMember())
adjustMemberFunctionCC(
R, !(D.isStaticMember() || D.isExplicitObjectMemberFunction()),
D.isCtorOrDtor(), D.getIdentifierLoc());
bool isFriend = false;
FunctionTemplateDecl *FunctionTemplate = nullptr;
bool isMemberSpecialization = false;
bool isFunctionTemplateSpecialization = false;
bool HasExplicitTemplateArgs = false;
TemplateArgumentListInfo TemplateArgs;
bool isVirtualOkay = false;
DeclContext *OriginalDC = DC;
bool IsLocalExternDecl = adjustContextForLocalExternDecl(DC);
FunctionDecl *NewFD = CreateNewFunctionDecl(*this, D, DC, R, TInfo, SC,
isVirtualOkay);
if (!NewFD) return nullptr;
if (OriginalLexicalContext && OriginalLexicalContext->isObjCContainer())
NewFD->setTopLevelDeclInObjCContainer();
// Set the lexical context. If this is a function-scope declaration, or has a
// C++ scope specifier, or is the object of a friend declaration, the lexical
// context will be different from the semantic context.
NewFD->setLexicalDeclContext(CurContext);
if (IsLocalExternDecl)
NewFD->setLocalExternDecl();
if (getLangOpts().CPlusPlus) {
// The rules for implicit inlines changed in C++20 for methods and friends
// with an in-class definition (when such a definition is not attached to
// the global module). This does not affect declarations that are already
// inline (whether explicitly or implicitly by being declared constexpr,
// consteval, etc).
// FIXME: We need a better way to separate C++ standard and clang modules.
bool ImplicitInlineCXX20 = !getLangOpts().CPlusPlusModules ||
!NewFD->getOwningModule() ||
NewFD->isFromGlobalModule() ||
NewFD->getOwningModule()->isHeaderLikeModule();
bool isInline = D.getDeclSpec().isInlineSpecified();
bool isVirtual = D.getDeclSpec().isVirtualSpecified();
bool hasExplicit = D.getDeclSpec().hasExplicitSpecifier();
isFriend = D.getDeclSpec().isFriendSpecified();
if (ImplicitInlineCXX20 && isFriend && D.isFunctionDefinition()) {
// Pre-C++20 [class.friend]p5
// A function can be defined in a friend declaration of a
// class . . . . Such a function is implicitly inline.
// Post C++20 [class.friend]p7
// Such a function is implicitly an inline function if it is attached
// to the global module.
NewFD->setImplicitlyInline();
}
// If this is a method defined in an __interface, and is not a constructor
// or an overloaded operator, then set the pure flag (isVirtual will already
// return true).
if (const CXXRecordDecl *Parent =
dyn_cast<CXXRecordDecl>(NewFD->getDeclContext())) {
if (Parent->isInterface() && cast<CXXMethodDecl>(NewFD)->isUserProvided())
NewFD->setIsPureVirtual(true);
// C++ [class.union]p2
// A union can have member functions, but not virtual functions.
if (isVirtual && Parent->isUnion()) {
Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_virtual_in_union);
NewFD->setInvalidDecl();
}
if ((Parent->isClass() || Parent->isStruct()) &&
Parent->hasAttr<SYCLSpecialClassAttr>() &&
NewFD->getKind() == Decl::Kind::CXXMethod && NewFD->getIdentifier() &&
NewFD->getName() == "__init" && D.isFunctionDefinition()) {
if (auto *Def = Parent->getDefinition())
Def->setInitMethod(true);
}
}
SetNestedNameSpecifier(*this, NewFD, D);
isMemberSpecialization = false;
isFunctionTemplateSpecialization = false;
if (D.isInvalidType())
NewFD->setInvalidDecl();
// Match up the template parameter lists with the scope specifier, then
// determine whether we have a template or a template specialization.
bool Invalid = false;
TemplateIdAnnotation *TemplateId =
D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
? D.getName().TemplateId
: nullptr;
TemplateParameterList *TemplateParams =
MatchTemplateParametersToScopeSpecifier(
D.getDeclSpec().getBeginLoc(), D.getIdentifierLoc(),
D.getCXXScopeSpec(), TemplateId, TemplateParamLists, isFriend,
isMemberSpecialization, Invalid);
if (TemplateParams) {
// Check that we can declare a template here.
if (CheckTemplateDeclScope(S, TemplateParams))
NewFD->setInvalidDecl();
if (TemplateParams->size() > 0) {
// This is a function template
// A destructor cannot be a template.
if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
Diag(NewFD->getLocation(), diag::err_destructor_template);
NewFD->setInvalidDecl();
// Function template with explicit template arguments.
} else if (TemplateId) {
Diag(D.getIdentifierLoc(), diag::err_function_template_partial_spec)
<< SourceRange(TemplateId->LAngleLoc, TemplateId->RAngleLoc);
NewFD->setInvalidDecl();
}
// If we're adding a template to a dependent context, we may need to
// rebuilding some of the types used within the template parameter list,
// now that we know what the current instantiation is.
if (DC->isDependentContext()) {
ContextRAII SavedContext(*this, DC);
if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
Invalid = true;
}
FunctionTemplate = FunctionTemplateDecl::Create(Context, DC,
NewFD->getLocation(),
Name, TemplateParams,
NewFD);
FunctionTemplate->setLexicalDeclContext(CurContext);
NewFD->setDescribedFunctionTemplate(FunctionTemplate);
// For source fidelity, store the other template param lists.
if (TemplateParamLists.size() > 1) {
NewFD->setTemplateParameterListsInfo(Context,
ArrayRef<TemplateParameterList *>(TemplateParamLists)
.drop_back(1));
}
} else {
// This is a function template specialization.
isFunctionTemplateSpecialization = true;
// For source fidelity, store all the template param lists.
if (TemplateParamLists.size() > 0)
NewFD->setTemplateParameterListsInfo(Context, TemplateParamLists);
// C++0x [temp.expl.spec]p20 forbids "template<> friend void foo(int);".
if (isFriend) {
// We want to remove the "template<>", found here.
SourceRange RemoveRange = TemplateParams->getSourceRange();
// If we remove the template<> and the name is not a
// template-id, we're actually silently creating a problem:
// the friend declaration will refer to an untemplated decl,
// and clearly the user wants a template specialization. So
// we need to insert '<>' after the name.
SourceLocation InsertLoc;
if (D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) {
InsertLoc = D.getName().getSourceRange().getEnd();
InsertLoc = getLocForEndOfToken(InsertLoc);
}
Diag(D.getIdentifierLoc(), diag::err_template_spec_decl_friend)
<< Name << RemoveRange
<< FixItHint::CreateRemoval(RemoveRange)
<< FixItHint::CreateInsertion(InsertLoc, "<>");
Invalid = true;
// Recover by faking up an empty template argument list.
HasExplicitTemplateArgs = true;
TemplateArgs.setLAngleLoc(InsertLoc);
TemplateArgs.setRAngleLoc(InsertLoc);
}
}
} else {
// Check that we can declare a template here.
if (!TemplateParamLists.empty() && isMemberSpecialization &&
CheckTemplateDeclScope(S, TemplateParamLists.back()))
NewFD->setInvalidDecl();
// All template param lists were matched against the scope specifier:
// this is NOT (an explicit specialization of) a template.
if (TemplateParamLists.size() > 0)
// For source fidelity, store all the template param lists.
NewFD->setTemplateParameterListsInfo(Context, TemplateParamLists);
// "friend void foo<>(int);" is an implicit specialization decl.
if (isFriend && TemplateId)
isFunctionTemplateSpecialization = true;
}
// If this is a function template specialization and the unqualified-id of
// the declarator-id is a template-id, convert the template argument list
// into our AST format and check for unexpanded packs.
if (isFunctionTemplateSpecialization && TemplateId) {
HasExplicitTemplateArgs = true;
TemplateArgs.setLAngleLoc(TemplateId->LAngleLoc);
TemplateArgs.setRAngleLoc(TemplateId->RAngleLoc);
ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
TemplateId->NumArgs);
translateTemplateArguments(TemplateArgsPtr, TemplateArgs);
// FIXME: Should we check for unexpanded packs if this was an (invalid)
// declaration of a function template partial specialization? Should we
// consider the unexpanded pack context to be a partial specialization?
for (const TemplateArgumentLoc &ArgLoc : TemplateArgs.arguments()) {
if (DiagnoseUnexpandedParameterPack(
ArgLoc, isFriend ? UPPC_FriendDeclaration
: UPPC_ExplicitSpecialization))
NewFD->setInvalidDecl();
}
}
if (Invalid) {
NewFD->setInvalidDecl();
if (FunctionTemplate)
FunctionTemplate->setInvalidDecl();
}
// C++ [dcl.fct.spec]p5:
// The virtual specifier shall only be used in declarations of
// nonstatic class member functions that appear within a
// member-specification of a class declaration; see 10.3.
//
if (isVirtual && !NewFD->isInvalidDecl()) {
if (!isVirtualOkay) {
Diag(D.getDeclSpec().getVirtualSpecLoc(),
diag::err_virtual_non_function);
} else if (!CurContext->isRecord()) {
// 'virtual' was specified outside of the class.
Diag(D.getDeclSpec().getVirtualSpecLoc(),
diag::err_virtual_out_of_class)
<< FixItHint::CreateRemoval(D.getDeclSpec().getVirtualSpecLoc());
} else if (NewFD->getDescribedFunctionTemplate()) {
// C++ [temp.mem]p3:
// A member function template shall not be virtual.
Diag(D.getDeclSpec().getVirtualSpecLoc(),
diag::err_virtual_member_function_template)
<< FixItHint::CreateRemoval(D.getDeclSpec().getVirtualSpecLoc());
} else {
// Okay: Add virtual to the method.
NewFD->setVirtualAsWritten(true);
}
if (getLangOpts().CPlusPlus14 &&
NewFD->getReturnType()->isUndeducedType())
Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_auto_fn_virtual);
}
// C++ [dcl.fct.spec]p3:
// The inline specifier shall not appear on a block scope function
// declaration.
if (isInline && !NewFD->isInvalidDecl()) {
if (CurContext->isFunctionOrMethod()) {
// 'inline' is not allowed on block scope function declaration.
Diag(D.getDeclSpec().getInlineSpecLoc(),
diag::err_inline_declaration_block_scope) << Name
<< FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
}
}
// C++ [dcl.fct.spec]p6:
// The explicit specifier shall be used only in the declaration of a
// constructor or conversion function within its class definition;
// see 12.3.1 and 12.3.2.
if (hasExplicit && !NewFD->isInvalidDecl() &&
!isa<CXXDeductionGuideDecl>(NewFD)) {
if (!CurContext->isRecord()) {
// 'explicit' was specified outside of the class.
Diag(D.getDeclSpec().getExplicitSpecLoc(),
diag::err_explicit_out_of_class)
<< FixItHint::CreateRemoval(D.getDeclSpec().getExplicitSpecRange());
} else if (!isa<CXXConstructorDecl>(NewFD) &&
!isa<CXXConversionDecl>(NewFD)) {
// 'explicit' was specified on a function that wasn't a constructor
// or conversion function.
Diag(D.getDeclSpec().getExplicitSpecLoc(),
diag::err_explicit_non_ctor_or_conv_function)
<< FixItHint::CreateRemoval(D.getDeclSpec().getExplicitSpecRange());
}
}
ConstexprSpecKind ConstexprKind = D.getDeclSpec().getConstexprSpecifier();
if (ConstexprKind != ConstexprSpecKind::Unspecified) {
// C++11 [dcl.constexpr]p2: constexpr functions and constexpr constructors
// are implicitly inline.
NewFD->setImplicitlyInline();
// C++11 [dcl.constexpr]p3: functions declared constexpr are required to
// be either constructors or to return a literal type. Therefore,
// destructors cannot be declared constexpr.
if (isa<CXXDestructorDecl>(NewFD) &&
(!getLangOpts().CPlusPlus20 ||
ConstexprKind == ConstexprSpecKind::Consteval)) {
Diag(D.getDeclSpec().getConstexprSpecLoc(), diag::err_constexpr_dtor)
<< static_cast<int>(ConstexprKind);
NewFD->setConstexprKind(getLangOpts().CPlusPlus20
? ConstexprSpecKind::Unspecified
: ConstexprSpecKind::Constexpr);
}
// C++20 [dcl.constexpr]p2: An allocation function, or a
// deallocation function shall not be declared with the consteval
// specifier.
if (ConstexprKind == ConstexprSpecKind::Consteval &&
NewFD->getDeclName().isAnyOperatorNewOrDelete()) {
Diag(D.getDeclSpec().getConstexprSpecLoc(),
diag::err_invalid_consteval_decl_kind)
<< NewFD;
NewFD->setConstexprKind(ConstexprSpecKind::Constexpr);
}
}
// If __module_private__ was specified, mark the function accordingly.
if (D.getDeclSpec().isModulePrivateSpecified()) {
if (isFunctionTemplateSpecialization) {
SourceLocation ModulePrivateLoc
= D.getDeclSpec().getModulePrivateSpecLoc();
Diag(ModulePrivateLoc, diag::err_module_private_specialization)
<< 0
<< FixItHint::CreateRemoval(ModulePrivateLoc);
} else {
NewFD->setModulePrivate();
if (FunctionTemplate)
FunctionTemplate->setModulePrivate();
}
}
if (isFriend) {
if (FunctionTemplate) {
FunctionTemplate->setObjectOfFriendDecl();
FunctionTemplate->setAccess(AS_public);
}
NewFD->setObjectOfFriendDecl();
NewFD->setAccess(AS_public);
}
// If a function is defined as defaulted or deleted, mark it as such now.
// We'll do the relevant checks on defaulted / deleted functions later.
switch (D.getFunctionDefinitionKind()) {
case FunctionDefinitionKind::Declaration:
case FunctionDefinitionKind::Definition:
break;
case FunctionDefinitionKind::Defaulted:
NewFD->setDefaulted();
break;
case FunctionDefinitionKind::Deleted:
NewFD->setDeletedAsWritten();
break;
}
if (ImplicitInlineCXX20 && isa<CXXMethodDecl>(NewFD) && DC == CurContext &&
D.isFunctionDefinition()) {
// Pre C++20 [class.mfct]p2:
// A member function may be defined (8.4) in its class definition, in
// which case it is an inline member function (7.1.2)
// Post C++20 [class.mfct]p1:
// If a member function is attached to the global module and is defined
// in its class definition, it is inline.
NewFD->setImplicitlyInline();
}
if (!isFriend && SC != SC_None) {
// C++ [temp.expl.spec]p2:
// The declaration in an explicit-specialization shall not be an
// export-declaration. An explicit specialization shall not use a
// storage-class-specifier other than thread_local.
//
// We diagnose friend declarations with storage-class-specifiers
// elsewhere.
if (isFunctionTemplateSpecialization || isMemberSpecialization) {
Diag(D.getDeclSpec().getStorageClassSpecLoc(),
diag::ext_explicit_specialization_storage_class)
<< FixItHint::CreateRemoval(
D.getDeclSpec().getStorageClassSpecLoc());
}
if (SC == SC_Static && !CurContext->isRecord() && DC->isRecord()) {
assert(isa<CXXMethodDecl>(NewFD) &&
"Out-of-line member function should be a CXXMethodDecl");
// C++ [class.static]p1:
// A data or function member of a class may be declared static
// in a class definition, in which case it is a static member of
// the class.
// Complain about the 'static' specifier if it's on an out-of-line
// member function definition.
// MSVC permits the use of a 'static' storage specifier on an
// out-of-line member function template declaration and class member
// template declaration (MSVC versions before 2015), warn about this.
Diag(D.getDeclSpec().getStorageClassSpecLoc(),
((!getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
cast<CXXRecordDecl>(DC)->getDescribedClassTemplate()) ||
(getLangOpts().MSVCCompat &&
NewFD->getDescribedFunctionTemplate()))
? diag::ext_static_out_of_line
: diag::err_static_out_of_line)
<< FixItHint::CreateRemoval(
D.getDeclSpec().getStorageClassSpecLoc());
}
}
// C++11 [except.spec]p15:
// A deallocation function with no exception-specification is treated
// as if it were specified with noexcept(true).
const FunctionProtoType *FPT = R->getAs<FunctionProtoType>();
if (Name.isAnyOperatorDelete() && getLangOpts().CPlusPlus11 && FPT &&
!FPT->hasExceptionSpec())
NewFD->setType(Context.getFunctionType(
FPT->getReturnType(), FPT->getParamTypes(),
FPT->getExtProtoInfo().withExceptionSpec(EST_BasicNoexcept)));
// C++20 [dcl.inline]/7
// If an inline function or variable that is attached to a named module
// is declared in a definition domain, it shall be defined in that
// domain.
// So, if the current declaration does not have a definition, we must
// check at the end of the TU (or when the PMF starts) to see that we
// have a definition at that point.
if (isInline && !D.isFunctionDefinition() && getLangOpts().CPlusPlus20 &&
NewFD->isInNamedModule()) {
PendingInlineFuncDecls.insert(NewFD);
}
}
// Filter out previous declarations that don't match the scope.
FilterLookupForScope(Previous, OriginalDC, S, shouldConsiderLinkage(NewFD),
D.getCXXScopeSpec().isNotEmpty() ||
isMemberSpecialization ||
isFunctionTemplateSpecialization);
// Handle GNU asm-label extension (encoded as an attribute).
if (Expr *E = D.getAsmLabel()) {
// The parser guarantees this is a string.
StringLiteral *SE = cast<StringLiteral>(E);
NewFD->addAttr(
AsmLabelAttr::Create(Context, SE->getString(), SE->getStrTokenLoc(0)));
} else if (!ExtnameUndeclaredIdentifiers.empty()) {
llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
ExtnameUndeclaredIdentifiers.find(NewFD->getIdentifier());
if (I != ExtnameUndeclaredIdentifiers.end()) {
if (isDeclExternC(NewFD)) {
NewFD->addAttr(I->second);
ExtnameUndeclaredIdentifiers.erase(I);
} else
Diag(NewFD->getLocation(), diag::warn_redefine_extname_not_applied)
<< /*Variable*/0 << NewFD;
}
}
// Copy the parameter declarations from the declarator D to the function
// declaration NewFD, if they are available. First scavenge them into Params.
SmallVector<ParmVarDecl*, 16> Params;
unsigned FTIIdx;
if (D.isFunctionDeclarator(FTIIdx)) {
DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(FTIIdx).Fun;
// Check for C99 6.7.5.3p10 - foo(void) is a non-varargs
// function that takes no arguments, not a function that takes a
// single void argument.
// We let through "const void" here because Sema::GetTypeForDeclarator
// already checks for that case.
if (FTIHasNonVoidParameters(FTI) && FTI.Params[0].Param) {
for (unsigned i = 0, e = FTI.NumParams; i != e; ++i) {
ParmVarDecl *Param = cast<ParmVarDecl>(FTI.Params[i].Param);
assert(Param->getDeclContext() != NewFD && "Was set before ?");
Param->setDeclContext(NewFD);
Params.push_back(Param);
if (Param->isInvalidDecl())
NewFD->setInvalidDecl();
}
}
if (!getLangOpts().CPlusPlus) {
// In C, find all the tag declarations from the prototype and move them
// into the function DeclContext. Remove them from the surrounding tag
// injection context of the function, which is typically but not always
// the TU.
DeclContext *PrototypeTagContext =
getTagInjectionContext(NewFD->getLexicalDeclContext());
for (NamedDecl *NonParmDecl : FTI.getDeclsInPrototype()) {
auto *TD = dyn_cast<TagDecl>(NonParmDecl);
// We don't want to reparent enumerators. Look at their parent enum
// instead.
if (!TD) {
if (auto *ECD = dyn_cast<EnumConstantDecl>(NonParmDecl))
TD = cast<EnumDecl>(ECD->getDeclContext());
}
if (!TD)
continue;
DeclContext *TagDC = TD->getLexicalDeclContext();
if (!TagDC->containsDecl(TD))
continue;
TagDC->removeDecl(TD);
TD->setDeclContext(NewFD);
NewFD->addDecl(TD);
// Preserve the lexical DeclContext if it is not the surrounding tag
// injection context of the FD. In this example, the semantic context of
// E will be f and the lexical context will be S, while both the
// semantic and lexical contexts of S will be f:
// void f(struct S { enum E { a } f; } s);
if (TagDC != PrototypeTagContext)
TD->setLexicalDeclContext(TagDC);
}
}
} else if (const FunctionProtoType *FT = R->getAs<FunctionProtoType>()) {
// When we're declaring a function with a typedef, typeof, etc as in the
// following example, we'll need to synthesize (unnamed)
// parameters for use in the declaration.
//
// @code
// typedef void fn(int);
// fn f;
// @endcode
// Synthesize a parameter for each argument type.
for (const auto &AI : FT->param_types()) {
ParmVarDecl *Param =
BuildParmVarDeclForTypedef(NewFD, D.getIdentifierLoc(), AI);
Param->setScopeInfo(0, Params.size());
Params.push_back(Param);
}
} else {
assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 &&
"Should not need args for typedef of non-prototype fn");
}
// Finally, we know we have the right number of parameters, install them.
NewFD->setParams(Params);
// If this declarator is a declaration and not a definition, its parameters
// will not be pushed onto a scope chain. That means we will not issue any
// reserved identifier warnings for the declaration, but we will for the
// definition. Handle those here.
if (!D.isFunctionDefinition()) {
for (const ParmVarDecl *PVD : Params)
warnOnReservedIdentifier(PVD);
}
if (D.getDeclSpec().isNoreturnSpecified())
NewFD->addAttr(
C11NoReturnAttr::Create(Context, D.getDeclSpec().getNoreturnSpecLoc()));
// Functions returning a variably modified type violate C99 6.7.5.2p2
// because all functions have linkage.
if (!NewFD->isInvalidDecl() &&
NewFD->getReturnType()->isVariablyModifiedType()) {
Diag(NewFD->getLocation(), diag::err_vm_func_decl);
NewFD->setInvalidDecl();
}
// Apply an implicit SectionAttr if '#pragma clang section text' is active
if (PragmaClangTextSection.Valid && D.isFunctionDefinition() &&
!NewFD->hasAttr<SectionAttr>())
NewFD->addAttr(PragmaClangTextSectionAttr::CreateImplicit(
Context, PragmaClangTextSection.SectionName,
PragmaClangTextSection.PragmaLocation));
// Apply an implicit SectionAttr if #pragma code_seg is active.
if (CodeSegStack.CurrentValue && D.isFunctionDefinition() &&
!NewFD->hasAttr<SectionAttr>()) {
NewFD->addAttr(SectionAttr::CreateImplicit(
Context, CodeSegStack.CurrentValue->getString(),
CodeSegStack.CurrentPragmaLocation, SectionAttr::Declspec_allocate));
if (UnifySection(CodeSegStack.CurrentValue->getString(),
ASTContext::PSF_Implicit | ASTContext::PSF_Execute |
ASTContext::PSF_Read,
NewFD))
NewFD->dropAttr<SectionAttr>();
}
// Apply an implicit StrictGuardStackCheckAttr if #pragma strict_gs_check is
// active.
if (StrictGuardStackCheckStack.CurrentValue && D.isFunctionDefinition() &&
!NewFD->hasAttr<StrictGuardStackCheckAttr>())
NewFD->addAttr(StrictGuardStackCheckAttr::CreateImplicit(
Context, PragmaClangTextSection.PragmaLocation));
// Apply an implicit CodeSegAttr from class declspec or
// apply an implicit SectionAttr from #pragma code_seg if active.
if (!NewFD->hasAttr<CodeSegAttr>()) {
if (Attr *SAttr = getImplicitCodeSegOrSectionAttrForFunction(NewFD,
D.isFunctionDefinition())) {
NewFD->addAttr(SAttr);
}
}
// Handle attributes.
ProcessDeclAttributes(S, NewFD, D);
const auto *NewTVA = NewFD->getAttr<TargetVersionAttr>();
if (Context.getTargetInfo().getTriple().isAArch64() && NewTVA &&
!NewTVA->isDefaultVersion() &&
!Context.getTargetInfo().hasFeature("fmv")) {
// Don't add to scope fmv functions declarations if fmv disabled
AddToScope = false;
return NewFD;
}
if (getLangOpts().OpenCL || getLangOpts().HLSL) {
// Neither OpenCL nor HLSL allow an address space qualifyer on a return
// type.
//
// OpenCL v1.1 s6.5: Using an address space qualifier in a function return
// type declaration will generate a compilation error.
LangAS AddressSpace = NewFD->getReturnType().getAddressSpace();
if (AddressSpace != LangAS::Default) {
Diag(NewFD->getLocation(), diag::err_return_value_with_address_space);
NewFD->setInvalidDecl();
}
}
if (!getLangOpts().CPlusPlus) {
// Perform semantic checking on the function declaration.
if (!NewFD->isInvalidDecl() && NewFD->isMain())
CheckMain(NewFD, D.getDeclSpec());
if (!NewFD->isInvalidDecl() && NewFD->isMSVCRTEntryPoint())
CheckMSVCRTEntryPoint(NewFD);
if (!NewFD->isInvalidDecl())
D.setRedeclaration(CheckFunctionDeclaration(S, NewFD, Previous,
isMemberSpecialization,
D.isFunctionDefinition()));
else if (!Previous.empty())
// Recover gracefully from an invalid redeclaration.
D.setRedeclaration(true);
assert((NewFD->isInvalidDecl() || !D.isRedeclaration() ||
Previous.getResultKind() != LookupResultKind::FoundOverloaded) &&
"previous declaration set still overloaded");
// Diagnose no-prototype function declarations with calling conventions that
// don't support variadic calls. Only do this in C and do it after merging
// possibly prototyped redeclarations.
const FunctionType *FT = NewFD->getType()->castAs<FunctionType>();
if (isa<FunctionNoProtoType>(FT) && !D.isFunctionDefinition()) {
CallingConv CC = FT->getExtInfo().getCC();
if (!supportsVariadicCall(CC)) {
// Windows system headers sometimes accidentally use stdcall without
// (void) parameters, so we relax this to a warning.
int DiagID =
CC == CC_X86StdCall ? diag::warn_cconv_knr : diag::err_cconv_knr;
Diag(NewFD->getLocation(), DiagID)
<< FunctionType::getNameForCallConv(CC);
}
}
if (NewFD->getReturnType().hasNonTrivialToPrimitiveDestructCUnion() ||
NewFD->getReturnType().hasNonTrivialToPrimitiveCopyCUnion())
checkNonTrivialCUnion(
NewFD->getReturnType(), NewFD->getReturnTypeSourceRange().getBegin(),
NonTrivialCUnionContext::FunctionReturn, NTCUK_Destruct | NTCUK_Copy);
} else {
// C++11 [replacement.functions]p3:
// The program's definitions shall not be specified as inline.
//
// N.B. We diagnose declarations instead of definitions per LWG issue 2340.
//
// Suppress the diagnostic if the function is __attribute__((used)), since
// that forces an external definition to be emitted.
if (D.getDeclSpec().isInlineSpecified() &&
NewFD->isReplaceableGlobalAllocationFunction() &&
!NewFD->hasAttr<UsedAttr>())
Diag(D.getDeclSpec().getInlineSpecLoc(),
diag::ext_operator_new_delete_declared_inline)
<< NewFD->getDeclName();
if (const Expr *TRC = NewFD->getTrailingRequiresClause().ConstraintExpr) {
// C++20 [dcl.decl.general]p4:
// The optional requires-clause in an init-declarator or
// member-declarator shall be present only if the declarator declares a
// templated function.
//
// C++20 [temp.pre]p8:
// An entity is templated if it is
// - a template,
// - an entity defined or created in a templated entity,
// - a member of a templated entity,
// - an enumerator for an enumeration that is a templated entity, or
// - the closure type of a lambda-expression appearing in the
// declaration of a templated entity.
//
// [Note 6: A local class, a local or block variable, or a friend
// function defined in a templated entity is a templated entity.
// — end note]
//
// A templated function is a function template or a function that is
// templated. A templated class is a class template or a class that is
// templated. A templated variable is a variable template or a variable
// that is templated.
if (!FunctionTemplate) {
if (isFunctionTemplateSpecialization || isMemberSpecialization) {
// C++ [temp.expl.spec]p8 (proposed resolution for CWG2847):
// An explicit specialization shall not have a trailing
// requires-clause unless it declares a function template.
//
// Since a friend function template specialization cannot be
// definition, and since a non-template friend declaration with a
// trailing requires-clause must be a definition, we diagnose
// friend function template specializations with trailing
// requires-clauses on the same path as explicit specializations
// even though they aren't necessarily prohibited by the same
// language rule.
Diag(TRC->getBeginLoc(), diag::err_non_temp_spec_requires_clause)
<< isFriend;
} else if (isFriend && NewFD->isTemplated() &&
!D.isFunctionDefinition()) {
// C++ [temp.friend]p9:
// A non-template friend declaration with a requires-clause shall be
// a definition.
Diag(NewFD->getBeginLoc(),
diag::err_non_temp_friend_decl_with_requires_clause_must_be_def);
NewFD->setInvalidDecl();
} else if (!NewFD->isTemplated() ||
!(isa<CXXMethodDecl>(NewFD) || D.isFunctionDefinition())) {
Diag(TRC->getBeginLoc(),
diag::err_constrained_non_templated_function);
}
}
}
// We do not add HD attributes to specializations here because
// they may have different constexpr-ness compared to their
// templates and, after maybeAddHostDeviceAttrs() is applied,
// may end up with different effective targets. Instead, a
// specialization inherits its target attributes from its template
// in the CheckFunctionTemplateSpecialization() call below.
if (getLangOpts().CUDA && !isFunctionTemplateSpecialization)
CUDA().maybeAddHostDeviceAttrs(NewFD, Previous);
// Handle explicit specializations of function templates
// and friend function declarations with an explicit
// template argument list.
if (isFunctionTemplateSpecialization) {
bool isDependentSpecialization = false;
if (isFriend) {
// For friend function specializations, this is a dependent
// specialization if its semantic context is dependent, its
// type is dependent, or if its template-id is dependent.
isDependentSpecialization =
DC->isDependentContext() || NewFD->getType()->isDependentType() ||
(HasExplicitTemplateArgs &&
TemplateSpecializationType::
anyInstantiationDependentTemplateArguments(
TemplateArgs.arguments()));
assert((!isDependentSpecialization ||
(HasExplicitTemplateArgs == isDependentSpecialization)) &&
"dependent friend function specialization without template "
"args");
} else {
// For class-scope explicit specializations of function templates,
// if the lexical context is dependent, then the specialization
// is dependent.
isDependentSpecialization =
CurContext->isRecord() && CurContext->isDependentContext();
}
TemplateArgumentListInfo *ExplicitTemplateArgs =
HasExplicitTemplateArgs ? &TemplateArgs : nullptr;
if (isDependentSpecialization) {
// If it's a dependent specialization, it may not be possible
// to determine the primary template (for explicit specializations)
// or befriended declaration (for friends) until the enclosing
// template is instantiated. In such cases, we store the declarations
// found by name lookup and defer resolution until instantiation.
if (CheckDependentFunctionTemplateSpecialization(
NewFD, ExplicitTemplateArgs, Previous))
NewFD->setInvalidDecl();
} else if (!NewFD->isInvalidDecl()) {
if (CheckFunctionTemplateSpecialization(NewFD, ExplicitTemplateArgs,
Previous))
NewFD->setInvalidDecl();
}
} else if (isMemberSpecialization && !FunctionTemplate) {
if (CheckMemberSpecialization(NewFD, Previous))
NewFD->setInvalidDecl();
}
// Perform semantic checking on the function declaration.
if (!NewFD->isInvalidDecl() && NewFD->isMain())
CheckMain(NewFD, D.getDeclSpec());
if (!NewFD->isInvalidDecl() && NewFD->isMSVCRTEntryPoint())
CheckMSVCRTEntryPoint(NewFD);
if (!NewFD->isInvalidDecl())
D.setRedeclaration(CheckFunctionDeclaration(S, NewFD, Previous,
isMemberSpecialization,
D.isFunctionDefinition()));
else if (!Previous.empty())
// Recover gracefully from an invalid redeclaration.
D.setRedeclaration(true);
assert((NewFD->isInvalidDecl() || NewFD->isMultiVersion() ||
!D.isRedeclaration() ||
Previous.getResultKind() != LookupResultKind::FoundOverloaded) &&
"previous declaration set still overloaded");
NamedDecl *PrincipalDecl = (FunctionTemplate
? cast<NamedDecl>(FunctionTemplate)
: NewFD);
if (isFriend && NewFD->getPreviousDecl()) {
AccessSpecifier Access = AS_public;
if (!NewFD->isInvalidDecl())
Access = NewFD->getPreviousDecl()->getAccess();
NewFD->setAccess(Access);
if (FunctionTemplate) FunctionTemplate->setAccess(Access);
}
if (NewFD->isOverloadedOperator() && !DC->isRecord() &&
PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
PrincipalDecl->setNonMemberOperator();
// If we have a function template, check the template parameter
// list. This will check and merge default template arguments.
if (FunctionTemplate) {
FunctionTemplateDecl *PrevTemplate =
FunctionTemplate->getPreviousDecl();
CheckTemplateParameterList(FunctionTemplate->getTemplateParameters(),
PrevTemplate ? PrevTemplate->getTemplateParameters()
: nullptr,
D.getDeclSpec().isFriendSpecified()
? (D.isFunctionDefinition()
? TPC_FriendFunctionTemplateDefinition
: TPC_FriendFunctionTemplate)
: (D.getCXXScopeSpec().isSet() &&
DC && DC->isRecord() &&
DC->isDependentContext())
? TPC_ClassTemplateMember
: TPC_FunctionTemplate);
}
if (NewFD->isInvalidDecl()) {
// Ignore all the rest of this.
} else if (!D.isRedeclaration()) {
struct ActOnFDArgs ExtraArgs = { S, D, TemplateParamLists,
AddToScope };
// Fake up an access specifier if it's supposed to be a class member.
if (isa<CXXRecordDecl>(NewFD->getDeclContext()))
NewFD->setAccess(AS_public);
// Qualified decls generally require a previous declaration.
if (D.getCXXScopeSpec().isSet()) {
// ...with the major exception of templated-scope or
// dependent-scope friend declarations.
// TODO: we currently also suppress this check in dependent
// contexts because (1) the parameter depth will be off when
// matching friend templates and (2) we might actually be
// selecting a friend based on a dependent factor. But there
// are situations where these conditions don't apply and we
// can actually do this check immediately.
//
// Unless the scope is dependent, it's always an error if qualified
// redeclaration lookup found nothing at all. Diagnose that now;
// nothing will diagnose that error later.
if (isFriend &&
(D.getCXXScopeSpec().getScopeRep().isDependent() ||
(!Previous.empty() && CurContext->isDependentContext()))) {
// ignore these
} else if (NewFD->isCPUDispatchMultiVersion() ||
NewFD->isCPUSpecificMultiVersion()) {
// ignore this, we allow the redeclaration behavior here to create new
// versions of the function.
} else {
// The user tried to provide an out-of-line definition for a
// function that is a member of a class or namespace, but there
// was no such member function declared (C++ [class.mfct]p2,
// C++ [namespace.memdef]p2). For example:
//
// class X {
// void f() const;
// };
//
// void X::f() { } // ill-formed
//
// Complain about this problem, and attempt to suggest close
// matches (e.g., those that differ only in cv-qualifiers and
// whether the parameter types are references).
if (NamedDecl *Result = DiagnoseInvalidRedeclaration(
*this, Previous, NewFD, ExtraArgs, false, nullptr)) {
AddToScope = ExtraArgs.AddToScope;
return Result;
}
}
// Unqualified local friend declarations are required to resolve
// to something.
} else if (isFriend && cast<CXXRecordDecl>(CurContext)->isLocalClass()) {
if (NamedDecl *Result = DiagnoseInvalidRedeclaration(
*this, Previous, NewFD, ExtraArgs, true, S)) {
AddToScope = ExtraArgs.AddToScope;
return Result;
}
}
} else if (!D.isFunctionDefinition() &&
isa<CXXMethodDecl>(NewFD) && NewFD->isOutOfLine() &&
!isFriend && !isFunctionTemplateSpecialization &&
!isMemberSpecialization) {
// An out-of-line member function declaration must also be a
// definition (C++ [class.mfct]p2).
// Note that this is not the case for explicit specializations of
// function templates or member functions of class templates, per
// C++ [temp.expl.spec]p2. We also allow these declarations as an
// extension for compatibility with old SWIG code which likes to
// generate them.
Diag(NewFD->getLocation(), diag::ext_out_of_line_declaration)
<< D.getCXXScopeSpec().getRange();
}
}
if (getLangOpts().HLSL && D.isFunctionDefinition()) {
// Any top level function could potentially be specified as an entry.
if (!NewFD->isInvalidDecl() && S->getDepth() == 0 && Name.isIdentifier())
HLSL().ActOnTopLevelFunction(NewFD);
if (NewFD->hasAttr<HLSLShaderAttr>())
HLSL().CheckEntryPoint(NewFD);
}
// If this is the first declaration of a library builtin function, add
// attributes as appropriate.
if (!D.isRedeclaration()) {
if (IdentifierInfo *II = Previous.getLookupName().getAsIdentifierInfo()) {
if (unsigned BuiltinID = II->getBuiltinID()) {
bool InStdNamespace = Context.BuiltinInfo.isInStdNamespace(BuiltinID);
if (!InStdNamespace &&
NewFD->getDeclContext()->getRedeclContext()->isFileContext()) {
if (NewFD->getLanguageLinkage() == CLanguageLinkage) {
// Validate the type matches unless this builtin is specified as
// matching regardless of its declared type.
if (Context.BuiltinInfo.allowTypeMismatch(BuiltinID)) {
NewFD->addAttr(BuiltinAttr::CreateImplicit(Context, BuiltinID));
} else {
ASTContext::GetBuiltinTypeError Error;
LookupNecessaryTypesForBuiltin(S, BuiltinID);
QualType BuiltinType = Context.GetBuiltinType(BuiltinID, Error);
if (!Error && !BuiltinType.isNull() &&
Context.hasSameFunctionTypeIgnoringExceptionSpec(
NewFD->getType(), BuiltinType))
NewFD->addAttr(BuiltinAttr::CreateImplicit(Context, BuiltinID));
}
}
} else if (InStdNamespace && NewFD->isInStdNamespace() &&
isStdBuiltin(Context, NewFD, BuiltinID)) {
NewFD->addAttr(BuiltinAttr::CreateImplicit(Context, BuiltinID));
}
}
}
}
ProcessPragmaWeak(S, NewFD);
checkAttributesAfterMerging(*this, *NewFD);
AddKnownFunctionAttributes(NewFD);
if (NewFD->hasAttr<OverloadableAttr>() &&
!NewFD->getType()->getAs<FunctionProtoType>()) {
Diag(NewFD->getLocation(),
diag::err_attribute_overloadable_no_prototype)
<< NewFD;
NewFD->dropAttr<OverloadableAttr>();
}
// If there's a #pragma GCC visibility in scope, and this isn't a class
// member, set the visibility of this function.
if (!DC->isRecord() && NewFD->isExternallyVisible())
AddPushedVisibilityAttribute(NewFD);
// If there's a #pragma clang arc_cf_code_audited in scope, consider
// marking the function.
ObjC().AddCFAuditedAttribute(NewFD);
// If this is a function definition, check if we have to apply any
// attributes (i.e. optnone and no_builtin) due to a pragma.
if (D.isFunctionDefinition()) {
AddRangeBasedOptnone(NewFD);
AddImplicitMSFunctionNoBuiltinAttr(NewFD);
AddSectionMSAllocText(NewFD);
ModifyFnAttributesMSPragmaOptimize(NewFD);
}
// If this is the first declaration of an extern C variable, update
// the map of such variables.
if (NewFD->isFirstDecl() && !NewFD->isInvalidDecl() &&
isIncompleteDeclExternC(*this, NewFD))
RegisterLocallyScopedExternCDecl(NewFD, S);
// Set this FunctionDecl's range up to the right paren.
NewFD->setRangeEnd(D.getSourceRange().getEnd());
if (D.isRedeclaration() && !Previous.empty()) {
NamedDecl *Prev = Previous.getRepresentativeDecl();
checkDLLAttributeRedeclaration(*this, Prev, NewFD,
isMemberSpecialization ||
isFunctionTemplateSpecialization,
D.isFunctionDefinition());
}
if (getLangOpts().CUDA) {
IdentifierInfo *II = NewFD->getIdentifier();
if (II && II->isStr(CUDA().getConfigureFuncName()) &&
!NewFD->isInvalidDecl() &&
NewFD->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
if (!R->castAs<FunctionType>()->getReturnType()->isScalarType())
Diag(NewFD->getLocation(), diag::err_config_scalar_return)
<< CUDA().getConfigureFuncName();
Context.setcudaConfigureCallDecl(NewFD);
}
// Variadic functions, other than a *declaration* of printf, are not allowed
// in device-side CUDA code, unless someone passed
// -fcuda-allow-variadic-functions.
if (!getLangOpts().CUDAAllowVariadicFunctions && NewFD->isVariadic() &&
(NewFD->hasAttr<CUDADeviceAttr>() ||
NewFD->hasAttr<CUDAGlobalAttr>()) &&
!(II && II->isStr("printf") && NewFD->isExternC() &&
!D.isFunctionDefinition())) {
Diag(NewFD->getLocation(), diag::err_variadic_device_fn);
}
}
MarkUnusedFileScopedDecl(NewFD);
if (getLangOpts().OpenCL && NewFD->hasAttr<DeviceKernelAttr>()) {
// OpenCL v1.2 s6.8 static is invalid for kernel functions.
if (SC == SC_Static) {
Diag(D.getIdentifierLoc(), diag::err_static_kernel);
D.setInvalidType();
}
// OpenCL v1.2, s6.9 -- Kernels can only have return type void.
if (!NewFD->getReturnType()->isVoidType()) {
SourceRange RTRange = NewFD->getReturnTypeSourceRange();
Diag(D.getIdentifierLoc(), diag::err_expected_kernel_void_return_type)
<< (RTRange.isValid() ? FixItHint::CreateReplacement(RTRange, "void")
: FixItHint());
D.setInvalidType();
}
llvm::SmallPtrSet<const Type *, 16> ValidTypes;
for (auto *Param : NewFD->parameters())
checkIsValidOpenCLKernelParameter(*this, D, Param, ValidTypes);
if (getLangOpts().OpenCLCPlusPlus) {
if (DC->isRecord()) {
Diag(D.getIdentifierLoc(), diag::err_method_kernel);
D.setInvalidType();
}
if (FunctionTemplate) {
Diag(D.getIdentifierLoc(), diag::err_template_kernel);
D.setInvalidType();
}
}
}
if (getLangOpts().CPlusPlus) {
// Precalculate whether this is a friend function template with a constraint
// that depends on an enclosing template, per [temp.friend]p9.
if (isFriend && FunctionTemplate &&
FriendConstraintsDependOnEnclosingTemplate(NewFD)) {
NewFD->setFriendConstraintRefersToEnclosingTemplate(true);
// C++ [temp.friend]p9:
// A friend function template with a constraint that depends on a
// template parameter from an enclosing template shall be a definition.
if (!D.isFunctionDefinition()) {
Diag(NewFD->getBeginLoc(),
diag::err_friend_decl_with_enclosing_temp_constraint_must_be_def);
NewFD->setInvalidDecl();
}
}
if (FunctionTemplate) {
if (NewFD->isInvalidDecl())
FunctionTemplate->setInvalidDecl();
return FunctionTemplate;
}
if (isMemberSpecialization && !NewFD->isInvalidDecl())
CompleteMemberSpecialization(NewFD, Previous);
}
for (const ParmVarDecl *Param : NewFD->parameters()) {
QualType PT = Param->getType();
// OpenCL 2.0 pipe restrictions forbids pipe packet types to be non-value
// types.
if (getLangOpts().getOpenCLCompatibleVersion() >= 200) {
if(const PipeType *PipeTy = PT->getAs<PipeType>()) {
QualType ElemTy = PipeTy->getElementType();
if (ElemTy->isPointerOrReferenceType()) {
Diag(Param->getTypeSpecStartLoc(), diag::err_reference_pipe_type);
D.setInvalidType();
}
}
}
// WebAssembly tables can't be used as function parameters.
if (Context.getTargetInfo().getTriple().isWasm()) {
if (PT->getUnqualifiedDesugaredType()->isWebAssemblyTableType()) {
Diag(Param->getTypeSpecStartLoc(),
diag::err_wasm_table_as_function_parameter);
D.setInvalidType();
}
}
}
// Diagnose availability attributes. Availability cannot be used on functions
// that are run during load/unload.
if (const auto *attr = NewFD->getAttr<AvailabilityAttr>()) {
if (NewFD->hasAttr<ConstructorAttr>()) {
Diag(attr->getLocation(), diag::warn_availability_on_static_initializer)
<< 1;
NewFD->dropAttr<AvailabilityAttr>();
}
if (NewFD->hasAttr<DestructorAttr>()) {
Diag(attr->getLocation(), diag::warn_availability_on_static_initializer)
<< 2;
NewFD->dropAttr<AvailabilityAttr>();
}
}
// Diagnose no_builtin attribute on function declaration that are not a
// definition.
// FIXME: We should really be doing this in
// SemaDeclAttr.cpp::handleNoBuiltinAttr, unfortunately we only have access to
// the FunctionDecl and at this point of the code
// FunctionDecl::isThisDeclarationADefinition() which always returns `false`
// because Sema::ActOnStartOfFunctionDef has not been called yet.
if (const auto *NBA = NewFD->getAttr<NoBuiltinAttr>())
switch (D.getFunctionDefinitionKind()) {
case FunctionDefinitionKind::Defaulted:
case FunctionDefinitionKind::Deleted:
Diag(NBA->getLocation(),
diag::err_attribute_no_builtin_on_defaulted_deleted_function)
<< NBA->getSpelling();
break;
case FunctionDefinitionKind::Declaration:
Diag(NBA->getLocation(), diag::err_attribute_no_builtin_on_non_definition)
<< NBA->getSpelling();
break;
case FunctionDefinitionKind::Definition:
break;
}
// Similar to no_builtin logic above, at this point of the code
// FunctionDecl::isThisDeclarationADefinition() always returns `false`
// because Sema::ActOnStartOfFunctionDef has not been called yet.
if (Context.getTargetInfo().allowDebugInfoForExternalRef() &&
!NewFD->isInvalidDecl() &&
D.getFunctionDefinitionKind() == FunctionDefinitionKind::Declaration)
ExternalDeclarations.push_back(NewFD);
// Used for a warning on the 'next' declaration when used with a
// `routine(name)`.
if (getLangOpts().OpenACC)
OpenACC().ActOnFunctionDeclarator(NewFD);
return NewFD;
}
/// Return a CodeSegAttr from a containing class. The Microsoft docs say
/// when __declspec(code_seg) "is applied to a class, all member functions of
/// the class and nested classes -- this includes compiler-generated special
/// member functions -- are put in the specified segment."
/// The actual behavior is a little more complicated. The Microsoft compiler
/// won't check outer classes if there is an active value from #pragma code_seg.
/// The CodeSeg is always applied from the direct parent but only from outer
/// classes when the #pragma code_seg stack is empty. See:
/// https://reviews.llvm.org/D22931, the Microsoft feedback page is no longer
/// available since MS has removed the page.
static Attr *getImplicitCodeSegAttrFromClass(Sema &S, const FunctionDecl *FD) {
const auto *Method = dyn_cast<CXXMethodDecl>(FD);
if (!Method)
return nullptr;
const CXXRecordDecl *Parent = Method->getParent();
if (const auto *SAttr = Parent->getAttr<CodeSegAttr>()) {
Attr *NewAttr = SAttr->clone(S.getASTContext());
NewAttr->setImplicit(true);
return NewAttr;
}
// The Microsoft compiler won't check outer classes for the CodeSeg
// when the #pragma code_seg stack is active.
if (S.CodeSegStack.CurrentValue)
return nullptr;
while ((Parent = dyn_cast<CXXRecordDecl>(Parent->getParent()))) {
if (const auto *SAttr = Parent->getAttr<CodeSegAttr>()) {
Attr *NewAttr = SAttr->clone(S.getASTContext());
NewAttr->setImplicit(true);
return NewAttr;
}
}
return nullptr;
}
Attr *Sema::getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD,
bool IsDefinition) {
if (Attr *A = getImplicitCodeSegAttrFromClass(*this, FD))
return A;
if (!FD->hasAttr<SectionAttr>() && IsDefinition &&
CodeSegStack.CurrentValue)
return SectionAttr::CreateImplicit(
getASTContext(), CodeSegStack.CurrentValue->getString(),
CodeSegStack.CurrentPragmaLocation, SectionAttr::Declspec_allocate);
return nullptr;
}
bool Sema::canFullyTypeCheckRedeclaration(ValueDecl *NewD, ValueDecl *OldD,
QualType NewT, QualType OldT) {
if (!NewD->getLexicalDeclContext()->isDependentContext())
return true;
// For dependently-typed local extern declarations and friends, we can't
// perform a correct type check in general until instantiation:
//
// int f();
// template<typename T> void g() { T f(); }
//
// (valid if g() is only instantiated with T = int).
if (NewT->isDependentType() &&
(NewD->isLocalExternDecl() || NewD->getFriendObjectKind()))
return false;
// Similarly, if the previous declaration was a dependent local extern
// declaration, we don't really know its type yet.
if (OldT->isDependentType() && OldD->isLocalExternDecl())
return false;
return true;
}
bool Sema::shouldLinkDependentDeclWithPrevious(Decl *D, Decl *PrevDecl) {
if (!D->getLexicalDeclContext()->isDependentContext())
return true;
// Don't chain dependent friend function definitions until instantiation, to
// permit cases like
//
// void func();
// template<typename T> class C1 { friend void func() {} };
// template<typename T> class C2 { friend void func() {} };
//
// ... which is valid if only one of C1 and C2 is ever instantiated.
//
// FIXME: This need only apply to function definitions. For now, we proxy
// this by checking for a file-scope function. We do not want this to apply
// to friend declarations nominating member functions, because that gets in
// the way of access checks.
if (D->getFriendObjectKind() && D->getDeclContext()->isFileContext())
return false;
auto *VD = dyn_cast<ValueDecl>(D);
auto *PrevVD = dyn_cast<ValueDecl>(PrevDecl);
return !VD || !PrevVD ||
canFullyTypeCheckRedeclaration(VD, PrevVD, VD->getType(),
PrevVD->getType());
}
/// Check the target or target_version attribute of the function for
/// MultiVersion validity.
///
/// Returns true if there was an error, false otherwise.
static bool CheckMultiVersionValue(Sema &S, const FunctionDecl *FD) {
const auto *TA = FD->getAttr<TargetAttr>();
const auto *TVA = FD->getAttr<TargetVersionAttr>();
assert((TA || TVA) && "Expecting target or target_version attribute");
const TargetInfo &TargetInfo = S.Context.getTargetInfo();
enum ErrType { Feature = 0, Architecture = 1 };
if (TA) {
ParsedTargetAttr ParseInfo =
S.getASTContext().getTargetInfo().parseTargetAttr(TA->getFeaturesStr());
if (!ParseInfo.CPU.empty() && !TargetInfo.validateCpuIs(ParseInfo.CPU)) {
S.Diag(FD->getLocation(), diag::err_bad_multiversion_option)
<< Architecture << ParseInfo.CPU;
return true;
}
for (const auto &Feat : ParseInfo.Features) {
auto BareFeat = StringRef{Feat}.substr(1);
if (Feat[0] == '-') {
S.Diag(FD->getLocation(), diag::err_bad_multiversion_option)
<< Feature << ("no-" + BareFeat).str();
return true;
}
if (!TargetInfo.validateCpuSupports(BareFeat) ||
!TargetInfo.isValidFeatureName(BareFeat) ||
(BareFeat != "default" && TargetInfo.getFMVPriority(BareFeat) == 0)) {
S.Diag(FD->getLocation(), diag::err_bad_multiversion_option)
<< Feature << BareFeat;
return true;
}
}
}
if (TVA) {
llvm::SmallVector<StringRef, 8> Feats;
ParsedTargetAttr ParseInfo;
if (S.getASTContext().getTargetInfo().getTriple().isRISCV()) {
ParseInfo =
S.getASTContext().getTargetInfo().parseTargetAttr(TVA->getName());
for (auto &Feat : ParseInfo.Features)
Feats.push_back(StringRef{Feat}.substr(1));
} else {
assert(S.getASTContext().getTargetInfo().getTriple().isAArch64());
TVA->getFeatures(Feats);
}
for (const auto &Feat : Feats) {
if (!TargetInfo.validateCpuSupports(Feat)) {
S.Diag(FD->getLocation(), diag::err_bad_multiversion_option)
<< Feature << Feat;
return true;
}
}
}
return false;
}
// Provide a white-list of attributes that are allowed to be combined with
// multiversion functions.
static bool AttrCompatibleWithMultiVersion(attr::Kind Kind,
MultiVersionKind MVKind) {
// Note: this list/diagnosis must match the list in
// checkMultiversionAttributesAllSame.
switch (Kind) {
default:
return false;
case attr::ArmLocallyStreaming:
return MVKind == MultiVersionKind::TargetVersion ||
MVKind == MultiVersionKind::TargetClones;
case attr::Used:
return MVKind == MultiVersionKind::Target;
case attr::NonNull:
case attr::NoThrow:
return true;
}
}
static bool checkNonMultiVersionCompatAttributes(Sema &S,
const FunctionDecl *FD,
const FunctionDecl *CausedFD,
MultiVersionKind MVKind) {
const auto Diagnose = [FD, CausedFD, MVKind](Sema &S, const Attr *A) {
S.Diag(FD->getLocation(), diag::err_multiversion_disallowed_other_attr)
<< static_cast<unsigned>(MVKind) << A;
if (CausedFD)
S.Diag(CausedFD->getLocation(), diag::note_multiversioning_caused_here);
return true;
};
for (const Attr *A : FD->attrs()) {
switch (A->getKind()) {
case attr::CPUDispatch:
case attr::CPUSpecific:
if (MVKind != MultiVersionKind::CPUDispatch &&
MVKind != MultiVersionKind::CPUSpecific)
return Diagnose(S, A);
break;
case attr::Target:
if (MVKind != MultiVersionKind::Target)
return Diagnose(S, A);
break;
case attr::TargetVersion:
if (MVKind != MultiVersionKind::TargetVersion &&
MVKind != MultiVersionKind::TargetClones)
return Diagnose(S, A);
break;
case attr::TargetClones:
if (MVKind != MultiVersionKind::TargetClones &&
MVKind != MultiVersionKind::TargetVersion)
return Diagnose(S, A);
break;
default:
if (!AttrCompatibleWithMultiVersion(A->getKind(), MVKind))
return Diagnose(S, A);
break;
}
}
return false;
}
bool Sema::areMultiversionVariantFunctionsCompatible(
const FunctionDecl *OldFD, const FunctionDecl *NewFD,
const PartialDiagnostic &NoProtoDiagID,
const PartialDiagnosticAt &NoteCausedDiagIDAt,
const PartialDiagnosticAt &NoSupportDiagIDAt,
const PartialDiagnosticAt &DiffDiagIDAt, bool TemplatesSupported,
bool ConstexprSupported, bool CLinkageMayDiffer) {
enum DoesntSupport {
FuncTemplates = 0,
VirtFuncs = 1,
DeducedReturn = 2,
Constructors = 3,
Destructors = 4,
DeletedFuncs = 5,
DefaultedFuncs = 6,
ConstexprFuncs = 7,
ConstevalFuncs = 8,
Lambda = 9,
};
enum Different {
CallingConv = 0,
ReturnType = 1,
ConstexprSpec = 2,
InlineSpec = 3,
Linkage = 4,
LanguageLinkage = 5,
};
if (NoProtoDiagID.getDiagID() != 0 && OldFD &&
!OldFD->getType()->getAs<FunctionProtoType>()) {
Diag(OldFD->getLocation(), NoProtoDiagID);
Diag(NoteCausedDiagIDAt.first, NoteCausedDiagIDAt.second);
return true;
}
if (NoProtoDiagID.getDiagID() != 0 &&
!NewFD->getType()->getAs<FunctionProtoType>())
return Diag(NewFD->getLocation(), NoProtoDiagID);
if (!TemplatesSupported &&
NewFD->getTemplatedKind() == FunctionDecl::TK_FunctionTemplate)
return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second)
<< FuncTemplates;
if (const auto *NewCXXFD = dyn_cast<CXXMethodDecl>(NewFD)) {
if (NewCXXFD->isVirtual())
return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second)
<< VirtFuncs;
if (isa<CXXConstructorDecl>(NewCXXFD))
return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second)
<< Constructors;
if (isa<CXXDestructorDecl>(NewCXXFD))
return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second)
<< Destructors;
}
if (NewFD->isDeleted())
return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second)
<< DeletedFuncs;
if (NewFD->isDefaulted())
return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second)
<< DefaultedFuncs;
if (!ConstexprSupported && NewFD->isConstexpr())
return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second)
<< (NewFD->isConsteval() ? ConstevalFuncs : ConstexprFuncs);
QualType NewQType = Context.getCanonicalType(NewFD->getType());
const auto *NewType = cast<FunctionType>(NewQType);
QualType NewReturnType = NewType->getReturnType();
if (NewReturnType->isUndeducedType())
return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second)
<< DeducedReturn;
// Ensure the return type is identical.
if (OldFD) {
QualType OldQType = Context.getCanonicalType(OldFD->getType());
const auto *OldType = cast<FunctionType>(OldQType);
FunctionType::ExtInfo OldTypeInfo = OldType->getExtInfo();
FunctionType::ExtInfo NewTypeInfo = NewType->getExtInfo();
const auto *OldFPT = OldFD->getType()->getAs<FunctionProtoType>();
const auto *NewFPT = NewFD->getType()->getAs<FunctionProtoType>();
bool ArmStreamingCCMismatched = false;
if (OldFPT && NewFPT) {
unsigned Diff =
OldFPT->getAArch64SMEAttributes() ^ NewFPT->getAArch64SMEAttributes();
// Arm-streaming, arm-streaming-compatible and non-streaming versions
// cannot be mixed.
if (Diff & (FunctionType::SME_PStateSMEnabledMask |
FunctionType::SME_PStateSMCompatibleMask))
ArmStreamingCCMismatched = true;
}
if (OldTypeInfo.getCC() != NewTypeInfo.getCC() || ArmStreamingCCMismatched)
return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << CallingConv;
QualType OldReturnType = OldType->getReturnType();
if (OldReturnType != NewReturnType)
return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << ReturnType;
if (OldFD->getConstexprKind() != NewFD->getConstexprKind())
return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << ConstexprSpec;
if (OldFD->isInlineSpecified() != NewFD->isInlineSpecified())
return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << InlineSpec;
if (OldFD->getFormalLinkage() != NewFD->getFormalLinkage())
return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << Linkage;
if (!CLinkageMayDiffer && OldFD->isExternC() != NewFD->isExternC())
return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << LanguageLinkage;
if (CheckEquivalentExceptionSpec(OldFPT, OldFD->getLocation(), NewFPT,
NewFD->getLocation()))
return true;
}
return false;
}
static bool CheckMultiVersionAdditionalRules(Sema &S, const FunctionDecl *OldFD,
const FunctionDecl *NewFD,
bool CausesMV,
MultiVersionKind MVKind) {
if (!S.getASTContext().getTargetInfo().supportsMultiVersioning()) {
S.Diag(NewFD->getLocation(), diag::err_multiversion_not_supported);
if (OldFD)
S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
return true;
}
bool IsCPUSpecificCPUDispatchMVKind =
MVKind == MultiVersionKind::CPUDispatch ||
MVKind == MultiVersionKind::CPUSpecific;
if (CausesMV && OldFD &&
checkNonMultiVersionCompatAttributes(S, OldFD, NewFD, MVKind))
return true;
if (checkNonMultiVersionCompatAttributes(S, NewFD, nullptr, MVKind))
return true;
// Only allow transition to MultiVersion if it hasn't been used.
if (OldFD && CausesMV && OldFD->isUsed(false)) {
S.Diag(NewFD->getLocation(), diag::err_multiversion_after_used);
S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
return true;
}
return S.areMultiversionVariantFunctionsCompatible(
OldFD, NewFD, S.PDiag(diag::err_multiversion_noproto),
PartialDiagnosticAt(NewFD->getLocation(),
S.PDiag(diag::note_multiversioning_caused_here)),
PartialDiagnosticAt(NewFD->getLocation(),
S.PDiag(diag::err_multiversion_doesnt_support)
<< static_cast<unsigned>(MVKind)),
PartialDiagnosticAt(NewFD->getLocation(),
S.PDiag(diag::err_multiversion_diff)),
/*TemplatesSupported=*/false,
/*ConstexprSupported=*/!IsCPUSpecificCPUDispatchMVKind,
/*CLinkageMayDiffer=*/false);
}
/// Check the validity of a multiversion function declaration that is the
/// first of its kind. Also sets the multiversion'ness' of the function itself.
///
/// This sets NewFD->isInvalidDecl() to true if there was an error.
///
/// Returns true if there was an error, false otherwise.
static bool CheckMultiVersionFirstFunction(Sema &S, FunctionDecl *FD) {
MultiVersionKind MVKind = FD->getMultiVersionKind();
assert(MVKind != MultiVersionKind::None &&
"Function lacks multiversion attribute");
const auto *TA = FD->getAttr<TargetAttr>();
const auto *TVA = FD->getAttr<TargetVersionAttr>();
// The target attribute only causes MV if this declaration is the default,
// otherwise it is treated as a normal function.
if (TA && !TA->isDefaultVersion())
return false;
if ((TA || TVA) && CheckMultiVersionValue(S, FD)) {
FD->setInvalidDecl();
return true;
}
if (CheckMultiVersionAdditionalRules(S, nullptr, FD, true, MVKind)) {
FD->setInvalidDecl();
return true;
}
FD->setIsMultiVersion();
return false;
}
static bool PreviousDeclsHaveMultiVersionAttribute(const FunctionDecl *FD) {
for (const Decl *D = FD->getPreviousDecl(); D; D = D->getPreviousDecl()) {
if (D->getAsFunction()->getMultiVersionKind() != MultiVersionKind::None)
return true;
}
return false;
}
static void patchDefaultTargetVersion(FunctionDecl *From, FunctionDecl *To) {
if (!From->getASTContext().getTargetInfo().getTriple().isAArch64() &&
!From->getASTContext().getTargetInfo().getTriple().isRISCV())
return;
MultiVersionKind MVKindFrom = From->getMultiVersionKind();
MultiVersionKind MVKindTo = To->getMultiVersionKind();
if (MVKindTo == MultiVersionKind::None &&
(MVKindFrom == MultiVersionKind::TargetVersion ||
MVKindFrom == MultiVersionKind::TargetClones))
To->addAttr(TargetVersionAttr::CreateImplicit(
To->getASTContext(), "default", To->getSourceRange()));
}
static bool CheckDeclarationCausesMultiVersioning(Sema &S, FunctionDecl *OldFD,
FunctionDecl *NewFD,
bool &Redeclaration,
NamedDecl *&OldDecl,
LookupResult &Previous) {
assert(!OldFD->isMultiVersion() && "Unexpected MultiVersion");
const auto *NewTA = NewFD->getAttr<TargetAttr>();
const auto *OldTA = OldFD->getAttr<TargetAttr>();
const auto *NewTVA = NewFD->getAttr<TargetVersionAttr>();
const auto *OldTVA = OldFD->getAttr<TargetVersionAttr>();
assert((NewTA || NewTVA) && "Excpecting target or target_version attribute");
// The definitions should be allowed in any order. If we have discovered
// a new target version and the preceeding was the default, then add the
// corresponding attribute to it.
patchDefaultTargetVersion(NewFD, OldFD);
// If the old decl is NOT MultiVersioned yet, and we don't cause that
// to change, this is a simple redeclaration.
if (NewTA && !NewTA->isDefaultVersion() &&
(!OldTA || OldTA->getFeaturesStr() == NewTA->getFeaturesStr()))
return false;
// Otherwise, this decl causes MultiVersioning.
if (CheckMultiVersionAdditionalRules(S, OldFD, NewFD, true,
NewTVA ? MultiVersionKind::TargetVersion
: MultiVersionKind::Target)) {
NewFD->setInvalidDecl();
return true;
}
if (CheckMultiVersionValue(S, NewFD)) {
NewFD->setInvalidDecl();
return true;
}
// If this is 'default', permit the forward declaration.
if ((NewTA && NewTA->isDefaultVersion() && !OldTA) ||
(NewTVA && NewTVA->isDefaultVersion() && !OldTVA)) {
Redeclaration = true;
OldDecl = OldFD;
OldFD->setIsMultiVersion();
NewFD->setIsMultiVersion();
return false;
}
if ((OldTA || OldTVA) && CheckMultiVersionValue(S, OldFD)) {
S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here);
NewFD->setInvalidDecl();
return true;
}
if (NewTA) {
ParsedTargetAttr OldParsed =
S.getASTContext().getTargetInfo().parseTargetAttr(
OldTA->getFeaturesStr());
llvm::sort(OldParsed.Features);
ParsedTargetAttr NewParsed =
S.getASTContext().getTargetInfo().parseTargetAttr(
NewTA->getFeaturesStr());
// Sort order doesn't matter, it just needs to be consistent.
llvm::sort(NewParsed.Features);
if (OldParsed == NewParsed) {
S.Diag(NewFD->getLocation(), diag::err_multiversion_duplicate);
S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
NewFD->setInvalidDecl();
return true;
}
}
for (const auto *FD : OldFD->redecls()) {
const auto *CurTA = FD->getAttr<TargetAttr>();
const auto *CurTVA = FD->getAttr<TargetVersionAttr>();
// We allow forward declarations before ANY multiversioning attributes, but
// nothing after the fact.
if (PreviousDeclsHaveMultiVersionAttribute(FD) &&
((NewTA && (!CurTA || CurTA->isInherited())) ||
(NewTVA && (!CurTVA || CurTVA->isInherited())))) {
S.Diag(FD->getLocation(), diag::err_multiversion_required_in_redecl)
<< (NewTA ? 0 : 2);
S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here);
NewFD->setInvalidDecl();
return true;
}
}
OldFD->setIsMultiVersion();
NewFD->setIsMultiVersion();
Redeclaration = false;
OldDecl = nullptr;
Previous.clear();
return false;
}
static bool MultiVersionTypesCompatible(FunctionDecl *Old, FunctionDecl *New) {
MultiVersionKind OldKind = Old->getMultiVersionKind();
MultiVersionKind NewKind = New->getMultiVersionKind();
if (OldKind == NewKind || OldKind == MultiVersionKind::None ||
NewKind == MultiVersionKind::None)
return true;
if (Old->getASTContext().getTargetInfo().getTriple().isAArch64()) {
switch (OldKind) {
case MultiVersionKind::TargetVersion:
return NewKind == MultiVersionKind::TargetClones;
case MultiVersionKind::TargetClones:
return NewKind == MultiVersionKind::TargetVersion;
default:
return false;
}
} else {
switch (OldKind) {
case MultiVersionKind::CPUDispatch:
return NewKind == MultiVersionKind::CPUSpecific;
case MultiVersionKind::CPUSpecific:
return NewKind == MultiVersionKind::CPUDispatch;
default:
return false;
}
}
}
/// Check the validity of a new function declaration being added to an existing
/// multiversioned declaration collection.
static bool CheckMultiVersionAdditionalDecl(
Sema &S, FunctionDecl *OldFD, FunctionDecl *NewFD,
const CPUDispatchAttr *NewCPUDisp, const CPUSpecificAttr *NewCPUSpec,
const TargetClonesAttr *NewClones, bool &Redeclaration, NamedDecl *&OldDecl,
LookupResult &Previous) {
// Disallow mixing of multiversioning types.
if (!MultiVersionTypesCompatible(OldFD, NewFD)) {
S.Diag(NewFD->getLocation(), diag::err_multiversion_types_mixed);
S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
NewFD->setInvalidDecl();
return true;
}
// Add the default target_version attribute if it's missing.
patchDefaultTargetVersion(OldFD, NewFD);
patchDefaultTargetVersion(NewFD, OldFD);
const auto *NewTA = NewFD->getAttr<TargetAttr>();
const auto *NewTVA = NewFD->getAttr<TargetVersionAttr>();
MultiVersionKind NewMVKind = NewFD->getMultiVersionKind();
[[maybe_unused]] MultiVersionKind OldMVKind = OldFD->getMultiVersionKind();
ParsedTargetAttr NewParsed;
if (NewTA) {
NewParsed = S.getASTContext().getTargetInfo().parseTargetAttr(
NewTA->getFeaturesStr());
llvm::sort(NewParsed.Features);
}
llvm::SmallVector<StringRef, 8> NewFeats;
if (NewTVA) {
NewTVA->getFeatures(NewFeats);
llvm::sort(NewFeats);
}
bool UseMemberUsingDeclRules =
S.CurContext->isRecord() && !NewFD->getFriendObjectKind();
bool MayNeedOverloadableChecks =
AllowOverloadingOfFunction(Previous, S.Context, NewFD);
// Next, check ALL non-invalid non-overloads to see if this is a redeclaration
// of a previous member of the MultiVersion set.
for (NamedDecl *ND : Previous) {
FunctionDecl *CurFD = ND->getAsFunction();
if (!CurFD || CurFD->isInvalidDecl())
continue;
if (MayNeedOverloadableChecks &&
S.IsOverload(NewFD, CurFD, UseMemberUsingDeclRules))
continue;
switch (NewMVKind) {
case MultiVersionKind::None:
assert(OldMVKind == MultiVersionKind::TargetClones &&
"Only target_clones can be omitted in subsequent declarations");
break;
case MultiVersionKind::Target: {
const auto *CurTA = CurFD->getAttr<TargetAttr>();
if (CurTA->getFeaturesStr() == NewTA->getFeaturesStr()) {
NewFD->setIsMultiVersion();
Redeclaration = true;
OldDecl = ND;
return false;
}
ParsedTargetAttr CurParsed =
S.getASTContext().getTargetInfo().parseTargetAttr(
CurTA->getFeaturesStr());
llvm::sort(CurParsed.Features);
if (CurParsed == NewParsed) {
S.Diag(NewFD->getLocation(), diag::err_multiversion_duplicate);
S.Diag(CurFD->getLocation(), diag::note_previous_declaration);
NewFD->setInvalidDecl();
return true;
}
break;
}
case MultiVersionKind::TargetVersion: {
if (const auto *CurTVA = CurFD->getAttr<TargetVersionAttr>()) {
if (CurTVA->getName() == NewTVA->getName()) {
NewFD->setIsMultiVersion();
Redeclaration = true;
OldDecl = ND;
return false;
}
llvm::SmallVector<StringRef, 8> CurFeats;
CurTVA->getFeatures(CurFeats);
llvm::sort(CurFeats);
if (CurFeats == NewFeats) {
S.Diag(NewFD->getLocation(), diag::err_multiversion_duplicate);
S.Diag(CurFD->getLocation(), diag::note_previous_declaration);
NewFD->setInvalidDecl();
return true;
}
} else if (const auto *CurClones = CurFD->getAttr<TargetClonesAttr>()) {
// Default
if (NewFeats.empty())
break;
for (unsigned I = 0; I < CurClones->featuresStrs_size(); ++I) {
llvm::SmallVector<StringRef, 8> CurFeats;
CurClones->getFeatures(CurFeats, I);
llvm::sort(CurFeats);
if (CurFeats == NewFeats) {
S.Diag(NewFD->getLocation(), diag::err_multiversion_duplicate);
S.Diag(CurFD->getLocation(), diag::note_previous_declaration);
NewFD->setInvalidDecl();
return true;
}
}
}
break;
}
case MultiVersionKind::TargetClones: {
assert(NewClones && "MultiVersionKind does not match attribute type");
if (const auto *CurClones = CurFD->getAttr<TargetClonesAttr>()) {
if (CurClones->featuresStrs_size() != NewClones->featuresStrs_size() ||
!std::equal(CurClones->featuresStrs_begin(),
CurClones->featuresStrs_end(),
NewClones->featuresStrs_begin())) {
S.Diag(NewFD->getLocation(), diag::err_target_clone_doesnt_match);
S.Diag(CurFD->getLocation(), diag::note_previous_declaration);
NewFD->setInvalidDecl();
return true;
}
} else if (const auto *CurTVA = CurFD->getAttr<TargetVersionAttr>()) {
llvm::SmallVector<StringRef, 8> CurFeats;
CurTVA->getFeatures(CurFeats);
llvm::sort(CurFeats);
// Default
if (CurFeats.empty())
break;
for (unsigned I = 0; I < NewClones->featuresStrs_size(); ++I) {
NewFeats.clear();
NewClones->getFeatures(NewFeats, I);
llvm::sort(NewFeats);
if (CurFeats == NewFeats) {
S.Diag(NewFD->getLocation(), diag::err_multiversion_duplicate);
S.Diag(CurFD->getLocation(), diag::note_previous_declaration);
NewFD->setInvalidDecl();
return true;
}
}
break;
}
Redeclaration = true;
OldDecl = CurFD;
NewFD->setIsMultiVersion();
return false;
}
case MultiVersionKind::CPUSpecific:
case MultiVersionKind::CPUDispatch: {
const auto *CurCPUSpec = CurFD->getAttr<CPUSpecificAttr>();
const auto *CurCPUDisp = CurFD->getAttr<CPUDispatchAttr>();
// Handle CPUDispatch/CPUSpecific versions.
// Only 1 CPUDispatch function is allowed, this will make it go through
// the redeclaration errors.
if (NewMVKind == MultiVersionKind::CPUDispatch &&
CurFD->hasAttr<CPUDispatchAttr>()) {
if (CurCPUDisp->cpus_size() == NewCPUDisp->cpus_size() &&
std::equal(
CurCPUDisp->cpus_begin(), CurCPUDisp->cpus_end(),
NewCPUDisp->cpus_begin(),
[](const IdentifierInfo *Cur, const IdentifierInfo *New) {
return Cur->getName() == New->getName();
})) {
NewFD->setIsMultiVersion();
Redeclaration = true;
OldDecl = ND;
return false;
}
// If the declarations don't match, this is an error condition.
S.Diag(NewFD->getLocation(), diag::err_cpu_dispatch_mismatch);
S.Diag(CurFD->getLocation(), diag::note_previous_declaration);
NewFD->setInvalidDecl();
return true;
}
if (NewMVKind == MultiVersionKind::CPUSpecific && CurCPUSpec) {
if (CurCPUSpec->cpus_size() == NewCPUSpec->cpus_size() &&
std::equal(
CurCPUSpec->cpus_begin(), CurCPUSpec->cpus_end(),
NewCPUSpec->cpus_begin(),
[](const IdentifierInfo *Cur, const IdentifierInfo *New) {
return Cur->getName() == New->getName();
})) {
NewFD->setIsMultiVersion();
Redeclaration = true;
OldDecl = ND;
return false;
}
// Only 1 version of CPUSpecific is allowed for each CPU.
for (const IdentifierInfo *CurII : CurCPUSpec->cpus()) {
for (const IdentifierInfo *NewII : NewCPUSpec->cpus()) {
if (CurII == NewII) {
S.Diag(NewFD->getLocation(), diag::err_cpu_specific_multiple_defs)
<< NewII;
S.Diag(CurFD->getLocation(), diag::note_previous_declaration);
NewFD->setInvalidDecl();
return true;
}
}
}
}
break;
}
}
}
// Else, this is simply a non-redecl case. Checking the 'value' is only
// necessary in the Target case, since The CPUSpecific/Dispatch cases are
// handled in the attribute adding step.
if ((NewTA || NewTVA) && CheckMultiVersionValue(S, NewFD)) {
NewFD->setInvalidDecl();
return true;
}
if (CheckMultiVersionAdditionalRules(S, OldFD, NewFD,
!OldFD->isMultiVersion(), NewMVKind)) {
NewFD->setInvalidDecl();
return true;
}
// Permit forward declarations in the case where these two are compatible.
if (!OldFD->isMultiVersion()) {
OldFD->setIsMultiVersion();
NewFD->setIsMultiVersion();
Redeclaration = true;
OldDecl = OldFD;
return false;
}
NewFD->setIsMultiVersion();
Redeclaration = false;
OldDecl = nullptr;
Previous.clear();
return false;
}
/// Check the validity of a mulitversion function declaration.
/// Also sets the multiversion'ness' of the function itself.
///
/// This sets NewFD->isInvalidDecl() to true if there was an error.
///
/// Returns true if there was an error, false otherwise.
static bool CheckMultiVersionFunction(Sema &S, FunctionDecl *NewFD,
bool &Redeclaration, NamedDecl *&OldDecl,
LookupResult &Previous) {
const TargetInfo &TI = S.getASTContext().getTargetInfo();
// Check if FMV is disabled.
if (TI.getTriple().isAArch64() && !TI.hasFeature("fmv"))
return false;
const auto *NewTA = NewFD->getAttr<TargetAttr>();
const auto *NewTVA = NewFD->getAttr<TargetVersionAttr>();
const auto *NewCPUDisp = NewFD->getAttr<CPUDispatchAttr>();
const auto *NewCPUSpec = NewFD->getAttr<CPUSpecificAttr>();
const auto *NewClones = NewFD->getAttr<TargetClonesAttr>();
MultiVersionKind MVKind = NewFD->getMultiVersionKind();
// Main isn't allowed to become a multiversion function, however it IS
// permitted to have 'main' be marked with the 'target' optimization hint,
// for 'target_version' only default is allowed.
if (NewFD->isMain()) {
if (MVKind != MultiVersionKind::None &&
!(MVKind == MultiVersionKind::Target && !NewTA->isDefaultVersion()) &&
!(MVKind == MultiVersionKind::TargetVersion &&
NewTVA->isDefaultVersion())) {
S.Diag(NewFD->getLocation(), diag::err_multiversion_not_allowed_on_main);
NewFD->setInvalidDecl();
return true;
}
return false;
}
// Target attribute on AArch64 is not used for multiversioning
if (NewTA && TI.getTriple().isAArch64())
return false;
// Target attribute on RISCV is not used for multiversioning
if (NewTA && TI.getTriple().isRISCV())
return false;
if (!OldDecl || !OldDecl->getAsFunction() ||
!OldDecl->getDeclContext()->getRedeclContext()->Equals(
NewFD->getDeclContext()->getRedeclContext())) {
// If there's no previous declaration, AND this isn't attempting to cause
// multiversioning, this isn't an error condition.
if (MVKind == MultiVersionKind::None)
return false;
return CheckMultiVersionFirstFunction(S, NewFD);
}
FunctionDecl *OldFD = OldDecl->getAsFunction();
if (!OldFD->isMultiVersion() && MVKind == MultiVersionKind::None)
return false;
// Multiversioned redeclarations aren't allowed to omit the attribute, except
// for target_clones and target_version.
if (OldFD->isMultiVersion() && MVKind == MultiVersionKind::None &&
OldFD->getMultiVersionKind() != MultiVersionKind::TargetClones &&
OldFD->getMultiVersionKind() != MultiVersionKind::TargetVersion) {
S.Diag(NewFD->getLocation(), diag::err_multiversion_required_in_redecl)
<< (OldFD->getMultiVersionKind() != MultiVersionKind::Target);
NewFD->setInvalidDecl();
return true;
}
if (!OldFD->isMultiVersion()) {
switch (MVKind) {
case MultiVersionKind::Target:
case MultiVersionKind::TargetVersion:
return CheckDeclarationCausesMultiVersioning(
S, OldFD, NewFD, Redeclaration, OldDecl, Previous);
case MultiVersionKind::TargetClones:
if (OldFD->isUsed(false)) {
NewFD->setInvalidDecl();
return S.Diag(NewFD->getLocation(), diag::err_multiversion_after_used);
}
OldFD->setIsMultiVersion();
break;
case MultiVersionKind::CPUDispatch:
case MultiVersionKind::CPUSpecific:
case MultiVersionKind::None:
break;
}
}
// At this point, we have a multiversion function decl (in OldFD) AND an
// appropriate attribute in the current function decl. Resolve that these are
// still compatible with previous declarations.
return CheckMultiVersionAdditionalDecl(S, OldFD, NewFD, NewCPUDisp,
NewCPUSpec, NewClones, Redeclaration,
OldDecl, Previous);
}
static void CheckConstPureAttributesUsage(Sema &S, FunctionDecl *NewFD) {
bool IsPure = NewFD->hasAttr<PureAttr>();
bool IsConst = NewFD->hasAttr<ConstAttr>();
// If there are no pure or const attributes, there's nothing to check.
if (!IsPure && !IsConst)
return;
// If the function is marked both pure and const, we retain the const
// attribute because it makes stronger guarantees than the pure attribute, and
// we drop the pure attribute explicitly to prevent later confusion about
// semantics.
if (IsPure && IsConst) {
S.Diag(NewFD->getLocation(), diag::warn_const_attr_with_pure_attr);
NewFD->dropAttrs<PureAttr>();
}
// Constructors and destructors are functions which return void, so are
// handled here as well.
if (NewFD->getReturnType()->isVoidType()) {
S.Diag(NewFD->getLocation(), diag::warn_pure_function_returns_void)
<< IsConst;
NewFD->dropAttrs<PureAttr, ConstAttr>();
}
}
bool Sema::CheckFunctionDeclaration(Scope *S, FunctionDecl *NewFD,
LookupResult &Previous,
bool IsMemberSpecialization,
bool DeclIsDefn) {
assert(!NewFD->getReturnType()->isVariablyModifiedType() &&
"Variably modified return types are not handled here");
// Determine whether the type of this function should be merged with
// a previous visible declaration. This never happens for functions in C++,
// and always happens in C if the previous declaration was visible.
bool MergeTypeWithPrevious = !getLangOpts().CPlusPlus &&
!Previous.isShadowed();
bool Redeclaration = false;
NamedDecl *OldDecl = nullptr;
bool MayNeedOverloadableChecks = false;
inferLifetimeCaptureByAttribute(NewFD);
// Merge or overload the declaration with an existing declaration of
// the same name, if appropriate.
if (!Previous.empty()) {
// Determine whether NewFD is an overload of PrevDecl or
// a declaration that requires merging. If it's an overload,
// there's no more work to do here; we'll just add the new
// function to the scope.
if (!AllowOverloadingOfFunction(Previous, Context, NewFD)) {
NamedDecl *Candidate = Previous.getRepresentativeDecl();
if (shouldLinkPossiblyHiddenDecl(Candidate, NewFD)) {
Redeclaration = true;
OldDecl = Candidate;
}
} else {
MayNeedOverloadableChecks = true;
switch (CheckOverload(S, NewFD, Previous, OldDecl,
/*NewIsUsingDecl*/ false)) {
case OverloadKind::Match:
Redeclaration = true;
break;
case OverloadKind::NonFunction:
Redeclaration = true;
break;
case OverloadKind::Overload:
Redeclaration = false;
break;
}
}
}
// Check for a previous extern "C" declaration with this name.
if (!Redeclaration &&
checkForConflictWithNonVisibleExternC(*this, NewFD, Previous)) {
if (!Previous.empty()) {
// This is an extern "C" declaration with the same name as a previous
// declaration, and thus redeclares that entity...
Redeclaration = true;
OldDecl = Previous.getFoundDecl();
MergeTypeWithPrevious = false;
// ... except in the presence of __attribute__((overloadable)).
if (OldDecl->hasAttr<OverloadableAttr>() ||
NewFD->hasAttr<OverloadableAttr>()) {
if (IsOverload(NewFD, cast<FunctionDecl>(OldDecl), false)) {
MayNeedOverloadableChecks = true;
Redeclaration = false;
OldDecl = nullptr;
}
}
}
}
if (CheckMultiVersionFunction(*this, NewFD, Redeclaration, OldDecl, Previous))
return Redeclaration;
// PPC MMA non-pointer types are not allowed as function return types.
if (Context.getTargetInfo().getTriple().isPPC64() &&
PPC().CheckPPCMMAType(NewFD->getReturnType(), NewFD->getLocation())) {
NewFD->setInvalidDecl();
}
CheckConstPureAttributesUsage(*this, NewFD);
// C++ [dcl.spec.auto.general]p12:
// Return type deduction for a templated function with a placeholder in its
// declared type occurs when the definition is instantiated even if the
// function body contains a return statement with a non-type-dependent
// operand.
//
// C++ [temp.dep.expr]p3:
// An id-expression is type-dependent if it is a template-id that is not a
// concept-id and is dependent; or if its terminal name is:
// - [...]
// - associated by name lookup with one or more declarations of member
// functions of a class that is the current instantiation declared with a
// return type that contains a placeholder type,
// - [...]
//
// If this is a templated function with a placeholder in its return type,
// make the placeholder type dependent since it won't be deduced until the
// definition is instantiated. We do this here because it needs to happen
// for implicitly instantiated member functions/member function templates.
if (getLangOpts().CPlusPlus14 &&
(NewFD->isDependentContext() &&
NewFD->getReturnType()->isUndeducedType())) {
const FunctionProtoType *FPT =
NewFD->getType()->castAs<FunctionProtoType>();
QualType NewReturnType = SubstAutoTypeDependent(FPT->getReturnType());
NewFD->setType(Context.getFunctionType(NewReturnType, FPT->getParamTypes(),
FPT->getExtProtoInfo()));
}
// C++11 [dcl.constexpr]p8:
// A constexpr specifier for a non-static member function that is not
// a constructor declares that member function to be const.
//
// This needs to be delayed until we know whether this is an out-of-line
// definition of a static member function.
//
// This rule is not present in C++1y, so we produce a backwards
// compatibility warning whenever it happens in C++11.
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
if (!getLangOpts().CPlusPlus14 && MD && MD->isConstexpr() &&
!MD->isStatic() && !isa<CXXConstructorDecl>(MD) &&
!isa<CXXDestructorDecl>(MD) && !MD->getMethodQualifiers().hasConst()) {
CXXMethodDecl *OldMD = nullptr;
if (OldDecl)
OldMD = dyn_cast_or_null<CXXMethodDecl>(OldDecl->getAsFunction());
if (!OldMD || !OldMD->isStatic()) {
const FunctionProtoType *FPT =
MD->getType()->castAs<FunctionProtoType>();
FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
EPI.TypeQuals.addConst();
MD->setType(Context.getFunctionType(FPT->getReturnType(),
FPT->getParamTypes(), EPI));
// Warn that we did this, if we're not performing template instantiation.
// In that case, we'll have warned already when the template was defined.
if (!inTemplateInstantiation()) {
SourceLocation AddConstLoc;
if (FunctionTypeLoc FTL = MD->getTypeSourceInfo()->getTypeLoc()
.IgnoreParens().getAs<FunctionTypeLoc>())
AddConstLoc = getLocForEndOfToken(FTL.getRParenLoc());
Diag(MD->getLocation(), diag::warn_cxx14_compat_constexpr_not_const)
<< FixItHint::CreateInsertion(AddConstLoc, " const");
}
}
}
if (Redeclaration) {
// NewFD and OldDecl represent declarations that need to be
// merged.
if (MergeFunctionDecl(NewFD, OldDecl, S, MergeTypeWithPrevious,
DeclIsDefn)) {
NewFD->setInvalidDecl();
return Redeclaration;
}
Previous.clear();
Previous.addDecl(OldDecl);
if (FunctionTemplateDecl *OldTemplateDecl =
dyn_cast<FunctionTemplateDecl>(OldDecl)) {
auto *OldFD = OldTemplateDecl->getTemplatedDecl();
FunctionTemplateDecl *NewTemplateDecl
= NewFD->getDescribedFunctionTemplate();
assert(NewTemplateDecl && "Template/non-template mismatch");
// The call to MergeFunctionDecl above may have created some state in
// NewTemplateDecl that needs to be merged with OldTemplateDecl before we
// can add it as a redeclaration.
NewTemplateDecl->mergePrevDecl(OldTemplateDecl);
NewFD->setPreviousDeclaration(OldFD);
if (NewFD->isCXXClassMember()) {
NewFD->setAccess(OldTemplateDecl->getAccess());
NewTemplateDecl->setAccess(OldTemplateDecl->getAccess());
}
// If this is an explicit specialization of a member that is a function
// template, mark it as a member specialization.
if (IsMemberSpecialization &&
NewTemplateDecl->getInstantiatedFromMemberTemplate()) {
NewTemplateDecl->setMemberSpecialization();
assert(OldTemplateDecl->isMemberSpecialization());
// Explicit specializations of a member template do not inherit deleted
// status from the parent member template that they are specializing.
if (OldFD->isDeleted()) {
// FIXME: This assert will not hold in the presence of modules.
assert(OldFD->getCanonicalDecl() == OldFD);
// FIXME: We need an update record for this AST mutation.
OldFD->setDeletedAsWritten(false);
}
}
} else {
if (shouldLinkDependentDeclWithPrevious(NewFD, OldDecl)) {
auto *OldFD = cast<FunctionDecl>(OldDecl);
// This needs to happen first so that 'inline' propagates.
NewFD->setPreviousDeclaration(OldFD);
if (NewFD->isCXXClassMember())
NewFD->setAccess(OldFD->getAccess());
}
}
} else if (!getLangOpts().CPlusPlus && MayNeedOverloadableChecks &&
!NewFD->getAttr<OverloadableAttr>()) {
assert((Previous.empty() ||
llvm::any_of(Previous,
[](const NamedDecl *ND) {
return ND->hasAttr<OverloadableAttr>();
})) &&
"Non-redecls shouldn't happen without overloadable present");
auto OtherUnmarkedIter = llvm::find_if(Previous, [](const NamedDecl *ND) {
const auto *FD = dyn_cast<FunctionDecl>(ND);
return FD && !FD->hasAttr<OverloadableAttr>();
});
if (OtherUnmarkedIter != Previous.end()) {
Diag(NewFD->getLocation(),
diag::err_attribute_overloadable_multiple_unmarked_overloads);
Diag((*OtherUnmarkedIter)->getLocation(),
diag::note_attribute_overloadable_prev_overload)
<< false;
NewFD->addAttr(OverloadableAttr::CreateImplicit(Context));
}
}
if (LangOpts.OpenMP)
OpenMP().ActOnFinishedFunctionDefinitionInOpenMPAssumeScope(NewFD);
if (NewFD->hasAttr<SYCLKernelEntryPointAttr>())
SYCL().CheckSYCLEntryPointFunctionDecl(NewFD);
if (NewFD->hasAttr<SYCLExternalAttr>())
SYCL().CheckSYCLExternalFunctionDecl(NewFD);
// Semantic checking for this function declaration (in isolation).
if (getLangOpts().CPlusPlus) {
// C++-specific checks.
if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) {
CheckConstructor(Constructor);
} else if (CXXDestructorDecl *Destructor =
dyn_cast<CXXDestructorDecl>(NewFD)) {
// We check here for invalid destructor names.
// If we have a friend destructor declaration that is dependent, we can't
// diagnose right away because cases like this are still valid:
// template <class T> struct A { friend T::X::~Y(); };
// struct B { struct Y { ~Y(); }; using X = Y; };
// template struct A<B>;
if (NewFD->getFriendObjectKind() == Decl::FriendObjectKind::FOK_None ||
!Destructor->getFunctionObjectParameterType()->isDependentType()) {
CanQualType ClassType =
Context.getCanonicalTagType(Destructor->getParent());
DeclarationName Name =
Context.DeclarationNames.getCXXDestructorName(ClassType);
if (NewFD->getDeclName() != Name) {
Diag(NewFD->getLocation(), diag::err_destructor_name);
NewFD->setInvalidDecl();
return Redeclaration;
}
}
} else if (auto *Guide = dyn_cast<CXXDeductionGuideDecl>(NewFD)) {
if (auto *TD = Guide->getDescribedFunctionTemplate())
CheckDeductionGuideTemplate(TD);
// A deduction guide is not on the list of entities that can be
// explicitly specialized.
if (Guide->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
Diag(Guide->getBeginLoc(), diag::err_deduction_guide_specialized)
<< /*explicit specialization*/ 1;
}
// Find any virtual functions that this function overrides.
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD)) {
if (!Method->isFunctionTemplateSpecialization() &&
!Method->getDescribedFunctionTemplate() &&
Method->isCanonicalDecl()) {
AddOverriddenMethods(Method->getParent(), Method);
}
if (Method->isVirtual() && NewFD->getTrailingRequiresClause())
// C++2a [class.virtual]p6
// A virtual method shall not have a requires-clause.
Diag(NewFD->getTrailingRequiresClause().ConstraintExpr->getBeginLoc(),
diag::err_constrained_virtual_method);
if (Method->isStatic())
checkThisInStaticMemberFunctionType(Method);
}
if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(NewFD))
ActOnConversionDeclarator(Conversion);
// Extra checking for C++ overloaded operators (C++ [over.oper]).
if (NewFD->isOverloadedOperator() &&
CheckOverloadedOperatorDeclaration(NewFD)) {
NewFD->setInvalidDecl();
return Redeclaration;
}
// Extra checking for C++0x literal operators (C++0x [over.literal]).
if (NewFD->getLiteralIdentifier() &&
CheckLiteralOperatorDeclaration(NewFD)) {
NewFD->setInvalidDecl();
return Redeclaration;
}
// In C++, check default arguments now that we have merged decls. Unless
// the lexical context is the class, because in this case this is done
// during delayed parsing anyway.
if (!CurContext->isRecord())
CheckCXXDefaultArguments(NewFD);
// If this function is declared as being extern "C", then check to see if
// the function returns a UDT (class, struct, or union type) that is not C
// compatible, and if it does, warn the user.
// But, issue any diagnostic on the first declaration only.
if (Previous.empty() && NewFD->isExternC()) {
QualType R = NewFD->getReturnType();
if (R->isIncompleteType() && !R->isVoidType())
Diag(NewFD->getLocation(), diag::warn_return_value_udt_incomplete)
<< NewFD << R;
else if (!R.isPODType(Context) && !R->isVoidType() &&
!R->isObjCObjectPointerType())
Diag(NewFD->getLocation(), diag::warn_return_value_udt) << NewFD << R;
}
// C++1z [dcl.fct]p6:
// [...] whether the function has a non-throwing exception-specification
// [is] part of the function type
//
// This results in an ABI break between C++14 and C++17 for functions whose
// declared type includes an exception-specification in a parameter or
// return type. (Exception specifications on the function itself are OK in
// most cases, and exception specifications are not permitted in most other
// contexts where they could make it into a mangling.)
if (!getLangOpts().CPlusPlus17 && !NewFD->getPrimaryTemplate()) {
auto HasNoexcept = [&](QualType T) -> bool {
// Strip off declarator chunks that could be between us and a function
// type. We don't need to look far, exception specifications are very
// restricted prior to C++17.
if (auto *RT = T->getAs<ReferenceType>())
T = RT->getPointeeType();
else if (T->isAnyPointerType())
T = T->getPointeeType();
else if (auto *MPT = T->getAs<MemberPointerType>())
T = MPT->getPointeeType();
if (auto *FPT = T->getAs<FunctionProtoType>())
if (FPT->isNothrow())
return true;
return false;
};
auto *FPT = NewFD->getType()->castAs<FunctionProtoType>();
bool AnyNoexcept = HasNoexcept(FPT->getReturnType());
for (QualType T : FPT->param_types())
AnyNoexcept |= HasNoexcept(T);
if (AnyNoexcept)
Diag(NewFD->getLocation(),
diag::warn_cxx17_compat_exception_spec_in_signature)
<< NewFD;
}
if (!Redeclaration && LangOpts.CUDA) {
bool IsKernel = NewFD->hasAttr<CUDAGlobalAttr>();
for (auto *Parm : NewFD->parameters()) {
if (!Parm->getType()->isDependentType() &&
Parm->hasAttr<CUDAGridConstantAttr>() &&
!(IsKernel && Parm->getType().isConstQualified()))
Diag(Parm->getAttr<CUDAGridConstantAttr>()->getLocation(),
diag::err_cuda_grid_constant_not_allowed);
}
CUDA().checkTargetOverload(NewFD, Previous);
}
}
if (DeclIsDefn && Context.getTargetInfo().getTriple().isAArch64())
ARM().CheckSMEFunctionDefAttributes(NewFD);
return Redeclaration;
}
void Sema::CheckMain(FunctionDecl *FD, const DeclSpec &DS) {
// [basic.start.main]p3
// The main function shall not be declared with C linkage-specification.
if (FD->isExternCContext())
Diag(FD->getLocation(), diag::ext_main_invalid_linkage_specification);
// C++11 [basic.start.main]p3:
// A program that [...] declares main to be inline, static or
// constexpr is ill-formed.
// C11 6.7.4p4: In a hosted environment, no function specifier(s) shall
// appear in a declaration of main.
// static main is not an error under C99, but we should warn about it.
// We accept _Noreturn main as an extension.
if (FD->getStorageClass() == SC_Static)
Diag(DS.getStorageClassSpecLoc(), getLangOpts().CPlusPlus
? diag::err_static_main : diag::warn_static_main)
<< FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
if (FD->isInlineSpecified())
Diag(DS.getInlineSpecLoc(), diag::err_inline_main)
<< FixItHint::CreateRemoval(DS.getInlineSpecLoc());
if (DS.isNoreturnSpecified()) {
SourceLocation NoreturnLoc = DS.getNoreturnSpecLoc();
SourceRange NoreturnRange(NoreturnLoc, getLocForEndOfToken(NoreturnLoc));
Diag(NoreturnLoc, diag::ext_noreturn_main);
Diag(NoreturnLoc, diag::note_main_remove_noreturn)
<< FixItHint::CreateRemoval(NoreturnRange);
}
if (FD->isConstexpr()) {
Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_main)
<< FD->isConsteval()
<< FixItHint::CreateRemoval(DS.getConstexprSpecLoc());
FD->setConstexprKind(ConstexprSpecKind::Unspecified);
}
if (getLangOpts().OpenCL) {
Diag(FD->getLocation(), diag::err_opencl_no_main)
<< FD->hasAttr<DeviceKernelAttr>();
FD->setInvalidDecl();
return;
}
if (FD->hasAttr<SYCLExternalAttr>()) {
Diag(FD->getLocation(), diag::err_sycl_external_invalid_main)
<< FD->getAttr<SYCLExternalAttr>();
FD->setInvalidDecl();
return;
}
// Functions named main in hlsl are default entries, but don't have specific
// signatures they are required to conform to.
if (getLangOpts().HLSL)
return;
QualType T = FD->getType();
assert(T->isFunctionType() && "function decl is not of function type");
const FunctionType* FT = T->castAs<FunctionType>();
// Set default calling convention for main()
if (FT->getCallConv() != CC_C) {
FT = Context.adjustFunctionType(FT, FT->getExtInfo().withCallingConv(CC_C));
FD->setType(QualType(FT, 0));
T = Context.getCanonicalType(FD->getType());
}
if (getLangOpts().GNUMode && !getLangOpts().CPlusPlus) {
// In C with GNU extensions we allow main() to have non-integer return
// type, but we should warn about the extension, and we disable the
// implicit-return-zero rule.
// GCC in C mode accepts qualified 'int'.
if (Context.hasSameUnqualifiedType(FT->getReturnType(), Context.IntTy))
FD->setHasImplicitReturnZero(true);
else {
Diag(FD->getTypeSpecStartLoc(), diag::ext_main_returns_nonint);
SourceRange RTRange = FD->getReturnTypeSourceRange();
if (RTRange.isValid())
Diag(RTRange.getBegin(), diag::note_main_change_return_type)
<< FixItHint::CreateReplacement(RTRange, "int");
}
} else {
// In C and C++, main magically returns 0 if you fall off the end;
// set the flag which tells us that.
// This is C++ [basic.start.main]p5 and C99 5.1.2.2.3.
// All the standards say that main() should return 'int'.
if (Context.hasSameType(FT->getReturnType(), Context.IntTy))
FD->setHasImplicitReturnZero(true);
else {
// Otherwise, this is just a flat-out error.
SourceRange RTRange = FD->getReturnTypeSourceRange();
Diag(FD->getTypeSpecStartLoc(), diag::err_main_returns_nonint)
<< (RTRange.isValid() ? FixItHint::CreateReplacement(RTRange, "int")
: FixItHint());
FD->setInvalidDecl(true);
}
// [basic.start.main]p3:
// A program that declares a function main that belongs to the global scope
// and is attached to a named module is ill-formed.
if (FD->isInNamedModule()) {
const SourceLocation start = FD->getTypeSpecStartLoc();
Diag(start, diag::warn_main_in_named_module)
<< FixItHint::CreateInsertion(start, "extern \"C++\" ", true);
}
}
// Treat protoless main() as nullary.
if (isa<FunctionNoProtoType>(FT)) return;
const FunctionProtoType* FTP = cast<const FunctionProtoType>(FT);
unsigned nparams = FTP->getNumParams();
assert(FD->getNumParams() == nparams);
bool HasExtraParameters = (nparams > 3);
if (FTP->isVariadic()) {
Diag(FD->getLocation(), diag::ext_variadic_main);
// FIXME: if we had information about the location of the ellipsis, we
// could add a FixIt hint to remove it as a parameter.
}
// Darwin passes an undocumented fourth argument of type char**. If
// other platforms start sprouting these, the logic below will start
// getting shifty.
if (nparams == 4 && Context.getTargetInfo().getTriple().isOSDarwin())
HasExtraParameters = false;
if (HasExtraParameters) {
Diag(FD->getLocation(), diag::err_main_surplus_args) << nparams;
FD->setInvalidDecl(true);
nparams = 3;
}
// FIXME: a lot of the following diagnostics would be improved
// if we had some location information about types.
QualType CharPP =
Context.getPointerType(Context.getPointerType(Context.CharTy));
QualType Expected[] = { Context.IntTy, CharPP, CharPP, CharPP };
for (unsigned i = 0; i < nparams; ++i) {
QualType AT = FTP->getParamType(i);
bool mismatch = true;
if (Context.hasSameUnqualifiedType(AT, Expected[i]))
mismatch = false;
else if (Expected[i] == CharPP) {
// As an extension, the following forms are okay:
// char const **
// char const * const *
// char * const *
QualifierCollector qs;
const PointerType* PT;
if ((PT = qs.strip(AT)->getAs<PointerType>()) &&
(PT = qs.strip(PT->getPointeeType())->getAs<PointerType>()) &&
Context.hasSameType(QualType(qs.strip(PT->getPointeeType()), 0),
Context.CharTy)) {
qs.removeConst();
mismatch = !qs.empty();
}
}
if (mismatch) {
Diag(FD->getLocation(), diag::err_main_arg_wrong) << i << Expected[i];
// TODO: suggest replacing given type with expected type
FD->setInvalidDecl(true);
}
}
if (nparams == 1 && !FD->isInvalidDecl()) {
Diag(FD->getLocation(), diag::warn_main_one_arg);
}
if (!FD->isInvalidDecl() && FD->getDescribedFunctionTemplate()) {
Diag(FD->getLocation(), diag::err_mainlike_template_decl) << FD;
FD->setInvalidDecl();
}
}
static bool isDefaultStdCall(FunctionDecl *FD, Sema &S) {
// Default calling convention for main and wmain is __cdecl
if (FD->getName() == "main" || FD->getName() == "wmain")
return false;
// Default calling convention for MinGW and Cygwin is __cdecl
const llvm::Triple &T = S.Context.getTargetInfo().getTriple();
if (T.isOSCygMing())
return false;
// Default calling convention for WinMain, wWinMain and DllMain
// is __stdcall on 32 bit Windows
if (T.isOSWindows() && T.getArch() == llvm::Triple::x86)
return true;
return false;
}
void Sema::CheckMSVCRTEntryPoint(FunctionDecl *FD) {
QualType T = FD->getType();
assert(T->isFunctionType() && "function decl is not of function type");
const FunctionType *FT = T->castAs<FunctionType>();
// Set an implicit return of 'zero' if the function can return some integral,
// enumeration, pointer or nullptr type.
if (FT->getReturnType()->isIntegralOrEnumerationType() ||
FT->getReturnType()->isAnyPointerType() ||
FT->getReturnType()->isNullPtrType())
// DllMain is exempt because a return value of zero means it failed.
if (FD->getName() != "DllMain")
FD->setHasImplicitReturnZero(true);
// Explicitly specified calling conventions are applied to MSVC entry points
if (!hasExplicitCallingConv(T)) {
if (isDefaultStdCall(FD, *this)) {
if (FT->getCallConv() != CC_X86StdCall) {
FT = Context.adjustFunctionType(
FT, FT->getExtInfo().withCallingConv(CC_X86StdCall));
FD->setType(QualType(FT, 0));
}
} else if (FT->getCallConv() != CC_C) {
FT = Context.adjustFunctionType(FT,
FT->getExtInfo().withCallingConv(CC_C));
FD->setType(QualType(FT, 0));
}
}
if (!FD->isInvalidDecl() && FD->getDescribedFunctionTemplate()) {
Diag(FD->getLocation(), diag::err_mainlike_template_decl) << FD;
FD->setInvalidDecl();
}
}
bool Sema::CheckForConstantInitializer(Expr *Init, unsigned DiagID) {
// FIXME: Need strict checking. In C89, we need to check for
// any assignment, increment, decrement, function-calls, or
// commas outside of a sizeof. In C99, it's the same list,
// except that the aforementioned are allowed in unevaluated
// expressions. Everything else falls under the
// "may accept other forms of constant expressions" exception.
//
// Regular C++ code will not end up here (exceptions: language extensions,
// OpenCL C++ etc), so the constant expression rules there don't matter.
if (Init->isValueDependent()) {
assert(Init->containsErrors() &&
"Dependent code should only occur in error-recovery path.");
return true;
}
const Expr *Culprit;
if (Init->isConstantInitializer(Context, false, &Culprit))
return false;
Diag(Culprit->getExprLoc(), DiagID) << Culprit->getSourceRange();
return true;
}
namespace {
// Visits an initialization expression to see if OrigDecl is evaluated in
// its own initialization and throws a warning if it does.
class SelfReferenceChecker
: public EvaluatedExprVisitor<SelfReferenceChecker> {
Sema &S;
Decl *OrigDecl;
bool isRecordType;
bool isPODType;
bool isReferenceType;
bool isInCXXOperatorCall;
bool isInitList;
llvm::SmallVector<unsigned, 4> InitFieldIndex;
public:
typedef EvaluatedExprVisitor<SelfReferenceChecker> Inherited;
SelfReferenceChecker(Sema &S, Decl *OrigDecl) : Inherited(S.Context),
S(S), OrigDecl(OrigDecl) {
isPODType = false;
isRecordType = false;
isReferenceType = false;
isInCXXOperatorCall = false;
isInitList = false;
if (ValueDecl *VD = dyn_cast<ValueDecl>(OrigDecl)) {
isPODType = VD->getType().isPODType(S.Context);
isRecordType = VD->getType()->isRecordType();
isReferenceType = VD->getType()->isReferenceType();
}
}
// For most expressions, just call the visitor. For initializer lists,
// track the index of the field being initialized since fields are
// initialized in order allowing use of previously initialized fields.
void CheckExpr(Expr *E) {
InitListExpr *InitList = dyn_cast<InitListExpr>(E);
if (!InitList) {
Visit(E);
return;
}
// Track and increment the index here.
isInitList = true;
InitFieldIndex.push_back(0);
for (auto *Child : InitList->children()) {
CheckExpr(cast<Expr>(Child));
++InitFieldIndex.back();
}
InitFieldIndex.pop_back();
}
// Returns true if MemberExpr is checked and no further checking is needed.
// Returns false if additional checking is required.
bool CheckInitListMemberExpr(MemberExpr *E, bool CheckReference) {
llvm::SmallVector<FieldDecl*, 4> Fields;
Expr *Base = E;
bool ReferenceField = false;
// Get the field members used.
while (MemberExpr *ME = dyn_cast<MemberExpr>(Base)) {
FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
if (!FD)
return false;
Fields.push_back(FD);
if (FD->getType()->isReferenceType())
ReferenceField = true;
Base = ME->getBase()->IgnoreParenImpCasts();
}
// Keep checking only if the base Decl is the same.
DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base);
if (!DRE || DRE->getDecl() != OrigDecl)
return false;
// A reference field can be bound to an unininitialized field.
if (CheckReference && !ReferenceField)
return true;
// Convert FieldDecls to their index number.
llvm::SmallVector<unsigned, 4> UsedFieldIndex;
for (const FieldDecl *I : llvm::reverse(Fields))
UsedFieldIndex.push_back(I->getFieldIndex());
// See if a warning is needed by checking the first difference in index
// numbers. If field being used has index less than the field being
// initialized, then the use is safe.
for (auto UsedIter = UsedFieldIndex.begin(),
UsedEnd = UsedFieldIndex.end(),
OrigIter = InitFieldIndex.begin(),
OrigEnd = InitFieldIndex.end();
UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
if (*UsedIter < *OrigIter)
return true;
if (*UsedIter > *OrigIter)
break;
}
// TODO: Add a different warning which will print the field names.
HandleDeclRefExpr(DRE);
return true;
}
// For most expressions, the cast is directly above the DeclRefExpr.
// For conditional operators, the cast can be outside the conditional
// operator if both expressions are DeclRefExpr's.
void HandleValue(Expr *E) {
E = E->IgnoreParens();
if (DeclRefExpr* DRE = dyn_cast<DeclRefExpr>(E)) {
HandleDeclRefExpr(DRE);
return;
}
if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
Visit(CO->getCond());
HandleValue(CO->getTrueExpr());
HandleValue(CO->getFalseExpr());
return;
}
if (BinaryConditionalOperator *BCO =
dyn_cast<BinaryConditionalOperator>(E)) {
Visit(BCO->getCond());
HandleValue(BCO->getFalseExpr());
return;
}
if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
if (Expr *SE = OVE->getSourceExpr())
HandleValue(SE);
return;
}
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
if (BO->getOpcode() == BO_Comma) {
Visit(BO->getLHS());
HandleValue(BO->getRHS());
return;
}
}
if (isa<MemberExpr>(E)) {
if (isInitList) {
if (CheckInitListMemberExpr(cast<MemberExpr>(E),
false /*CheckReference*/))
return;
}
Expr *Base = E->IgnoreParenImpCasts();
while (MemberExpr *ME = dyn_cast<MemberExpr>(Base)) {
// Check for static member variables and don't warn on them.
if (!isa<FieldDecl>(ME->getMemberDecl()))
return;
Base = ME->getBase()->IgnoreParenImpCasts();
}
if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base))
HandleDeclRefExpr(DRE);
return;
}
Visit(E);
}
// Reference types not handled in HandleValue are handled here since all
// uses of references are bad, not just r-value uses.
void VisitDeclRefExpr(DeclRefExpr *E) {
if (isReferenceType)
HandleDeclRefExpr(E);
}
void VisitImplicitCastExpr(ImplicitCastExpr *E) {
if (E->getCastKind() == CK_LValueToRValue) {
HandleValue(E->getSubExpr());
return;
}
Inherited::VisitImplicitCastExpr(E);
}
void VisitMemberExpr(MemberExpr *E) {
if (isInitList) {
if (CheckInitListMemberExpr(E, true /*CheckReference*/))
return;
}
// Don't warn on arrays since they can be treated as pointers.
if (E->getType()->canDecayToPointerType()) return;
// Warn when a non-static method call is followed by non-static member
// field accesses, which is followed by a DeclRefExpr.
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(E->getMemberDecl());
bool Warn = (MD && !MD->isStatic());
Expr *Base = E->getBase()->IgnoreParenImpCasts();
while (MemberExpr *ME = dyn_cast<MemberExpr>(Base)) {
if (!isa<FieldDecl>(ME->getMemberDecl()))
Warn = false;
Base = ME->getBase()->IgnoreParenImpCasts();
}
if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base)) {
if (Warn)
HandleDeclRefExpr(DRE);
return;
}
// The base of a MemberExpr is not a MemberExpr or a DeclRefExpr.
// Visit that expression.
Visit(Base);
}
void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
llvm::SaveAndRestore CxxOpCallScope(isInCXXOperatorCall, true);
Expr *Callee = E->getCallee();
if (isa<UnresolvedLookupExpr>(Callee))
return Inherited::VisitCXXOperatorCallExpr(E);
Visit(Callee);
for (auto Arg: E->arguments())
HandleValue(Arg->IgnoreParenImpCasts());
}
void VisitLambdaExpr(LambdaExpr *E) {
if (!isInCXXOperatorCall) {
Inherited::VisitLambdaExpr(E);
return;
}
for (Expr *Init : E->capture_inits())
if (DeclRefExpr *DRE = dyn_cast_if_present<DeclRefExpr>(Init))
HandleDeclRefExpr(DRE);
else if (Init)
Visit(Init);
}
void VisitUnaryOperator(UnaryOperator *E) {
// For POD record types, addresses of its own members are well-defined.
if (E->getOpcode() == UO_AddrOf && isRecordType &&
isa<MemberExpr>(E->getSubExpr()->IgnoreParens())) {
if (!isPODType)
HandleValue(E->getSubExpr());
return;
}
if (E->isIncrementDecrementOp()) {
HandleValue(E->getSubExpr());
return;
}
Inherited::VisitUnaryOperator(E);
}
void VisitObjCMessageExpr(ObjCMessageExpr *E) {}
void VisitCXXConstructExpr(CXXConstructExpr *E) {
if (E->getConstructor()->isCopyConstructor()) {
Expr *ArgExpr = E->getArg(0);
if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
if (ILE->getNumInits() == 1)
ArgExpr = ILE->getInit(0);
if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
if (ICE->getCastKind() == CK_NoOp)
ArgExpr = ICE->getSubExpr();
HandleValue(ArgExpr);
return;
}
Inherited::VisitCXXConstructExpr(E);
}
void VisitCallExpr(CallExpr *E) {
// Treat std::move as a use.
if (E->isCallToStdMove()) {
HandleValue(E->getArg(0));
return;
}
Inherited::VisitCallExpr(E);
}
void VisitBinaryOperator(BinaryOperator *E) {
if (E->isCompoundAssignmentOp()) {
HandleValue(E->getLHS());
Visit(E->getRHS());
return;
}
Inherited::VisitBinaryOperator(E);
}
// A custom visitor for BinaryConditionalOperator is needed because the
// regular visitor would check the condition and true expression separately
// but both point to the same place giving duplicate diagnostics.
void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) {
Visit(E->getCond());
Visit(E->getFalseExpr());
}
void HandleDeclRefExpr(DeclRefExpr *DRE) {
Decl* ReferenceDecl = DRE->getDecl();
if (OrigDecl != ReferenceDecl) return;
unsigned diag;
if (isReferenceType) {
diag = diag::warn_uninit_self_reference_in_reference_init;
} else if (cast<VarDecl>(OrigDecl)->isStaticLocal()) {
diag = diag::warn_static_self_reference_in_init;
} else if (isa<TranslationUnitDecl>(OrigDecl->getDeclContext()) ||
isa<NamespaceDecl>(OrigDecl->getDeclContext()) ||
DRE->getDecl()->getType()->isRecordType()) {
diag = diag::warn_uninit_self_reference_in_init;
} else {
// Local variables will be handled by the CFG analysis.
return;
}
S.DiagRuntimeBehavior(DRE->getBeginLoc(), DRE,
S.PDiag(diag)
<< DRE->getDecl() << OrigDecl->getLocation()
<< DRE->getSourceRange());
}
};
/// CheckSelfReference - Warns if OrigDecl is used in expression E.
static void CheckSelfReference(Sema &S, Decl* OrigDecl, Expr *E,
bool DirectInit) {
// Parameters arguments are occassionially constructed with itself,
// for instance, in recursive functions. Skip them.
if (isa<ParmVarDecl>(OrigDecl))
return;
E = E->IgnoreParens();
// Skip checking T a = a where T is not a record or reference type.
// Doing so is a way to silence uninitialized warnings.
if (!DirectInit && !cast<VarDecl>(OrigDecl)->getType()->isRecordType())
if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
if (ICE->getCastKind() == CK_LValueToRValue)
if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr()))
if (DRE->getDecl() == OrigDecl)
return;
SelfReferenceChecker(S, OrigDecl).CheckExpr(E);
}
} // end anonymous namespace
namespace {
// Simple wrapper to add the name of a variable or (if no variable is
// available) a DeclarationName into a diagnostic.
struct VarDeclOrName {
VarDecl *VDecl;
DeclarationName Name;
friend const Sema::SemaDiagnosticBuilder &
operator<<(const Sema::SemaDiagnosticBuilder &Diag, VarDeclOrName VN) {
return VN.VDecl ? Diag << VN.VDecl : Diag << VN.Name;
}
};
} // end anonymous namespace
QualType Sema::deduceVarTypeFromInitializer(VarDecl *VDecl,
DeclarationName Name, QualType Type,
TypeSourceInfo *TSI,
SourceRange Range, bool DirectInit,
Expr *Init) {
bool IsInitCapture = !VDecl;
assert((!VDecl || !VDecl->isInitCapture()) &&
"init captures are expected to be deduced prior to initialization");
VarDeclOrName VN{VDecl, Name};
DeducedType *Deduced = Type->getContainedDeducedType();
assert(Deduced && "deduceVarTypeFromInitializer for non-deduced type");
// Diagnose auto array declarations in C23, unless it's a supported extension.
if (getLangOpts().C23 && Type->isArrayType() &&
!isa_and_present<StringLiteral, InitListExpr>(Init)) {
Diag(Range.getBegin(), diag::err_auto_not_allowed)
<< (int)Deduced->getContainedAutoType()->getKeyword()
<< /*in array decl*/ 23 << Range;
return QualType();
}
// C++11 [dcl.spec.auto]p3
if (!Init) {
assert(VDecl && "no init for init capture deduction?");
// Except for class argument deduction, and then for an initializing
// declaration only, i.e. no static at class scope or extern.
if (!isa<DeducedTemplateSpecializationType>(Deduced) ||
VDecl->hasExternalStorage() ||
VDecl->isStaticDataMember()) {
Diag(VDecl->getLocation(), diag::err_auto_var_requires_init)
<< VDecl->getDeclName() << Type;
return QualType();
}
}
ArrayRef<Expr*> DeduceInits;
if (Init)
DeduceInits = Init;
auto *PL = dyn_cast_if_present<ParenListExpr>(Init);
if (DirectInit && PL)
DeduceInits = PL->exprs();
if (isa<DeducedTemplateSpecializationType>(Deduced)) {
assert(VDecl && "non-auto type for init capture deduction?");
InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl);
InitializationKind Kind = InitializationKind::CreateForInit(
VDecl->getLocation(), DirectInit, Init);
// FIXME: Initialization should not be taking a mutable list of inits.
SmallVector<Expr *, 8> InitsCopy(DeduceInits);
return DeduceTemplateSpecializationFromInitializer(TSI, Entity, Kind,
InitsCopy);
}
if (DirectInit) {
if (auto *IL = dyn_cast<InitListExpr>(Init))
DeduceInits = IL->inits();
}
// Deduction only works if we have exactly one source expression.
if (DeduceInits.empty()) {
// It isn't possible to write this directly, but it is possible to
// end up in this situation with "auto x(some_pack...);"
Diag(Init->getBeginLoc(), IsInitCapture
? diag::err_init_capture_no_expression
: diag::err_auto_var_init_no_expression)
<< VN << Type << Range;
return QualType();
}
if (DeduceInits.size() > 1) {
Diag(DeduceInits[1]->getBeginLoc(),
IsInitCapture ? diag::err_init_capture_multiple_expressions
: diag::err_auto_var_init_multiple_expressions)
<< VN << Type << Range;
return QualType();
}
Expr *DeduceInit = DeduceInits[0];
if (DirectInit && isa<InitListExpr>(DeduceInit)) {
Diag(Init->getBeginLoc(), IsInitCapture
? diag::err_init_capture_paren_braces
: diag::err_auto_var_init_paren_braces)
<< isa<InitListExpr>(Init) << VN << Type << Range;
return QualType();
}
// Expressions default to 'id' when we're in a debugger.
bool DefaultedAnyToId = false;
if (getLangOpts().DebuggerCastResultToId &&
Init->getType() == Context.UnknownAnyTy && !IsInitCapture) {
ExprResult Result = forceUnknownAnyToType(Init, Context.getObjCIdType());
if (Result.isInvalid()) {
return QualType();
}
Init = Result.get();
DefaultedAnyToId = true;
}
// C++ [dcl.decomp]p1:
// If the assignment-expression [...] has array type A and no ref-qualifier
// is present, e has type cv A
if (VDecl && isa<DecompositionDecl>(VDecl) &&
Context.hasSameUnqualifiedType(Type, Context.getAutoDeductType()) &&
DeduceInit->getType()->isConstantArrayType())
return Context.getQualifiedType(DeduceInit->getType(),
Type.getQualifiers());
QualType DeducedType;
TemplateDeductionInfo Info(DeduceInit->getExprLoc());
TemplateDeductionResult Result =
DeduceAutoType(TSI->getTypeLoc(), DeduceInit, DeducedType, Info);
if (Result != TemplateDeductionResult::Success &&
Result != TemplateDeductionResult::AlreadyDiagnosed) {
if (!IsInitCapture)
DiagnoseAutoDeductionFailure(VDecl, DeduceInit);
else if (isa<InitListExpr>(Init))
Diag(Range.getBegin(),
diag::err_init_capture_deduction_failure_from_init_list)
<< VN
<< (DeduceInit->getType().isNull() ? TSI->getType()
: DeduceInit->getType())
<< DeduceInit->getSourceRange();
else
Diag(Range.getBegin(), diag::err_init_capture_deduction_failure)
<< VN << TSI->getType()
<< (DeduceInit->getType().isNull() ? TSI->getType()
: DeduceInit->getType())
<< DeduceInit->getSourceRange();
}
// Warn if we deduced 'id'. 'auto' usually implies type-safety, but using
// 'id' instead of a specific object type prevents most of our usual
// checks.
// We only want to warn outside of template instantiations, though:
// inside a template, the 'id' could have come from a parameter.
if (!inTemplateInstantiation() && !DefaultedAnyToId && !IsInitCapture &&
!DeducedType.isNull() && DeducedType->isObjCIdType()) {
SourceLocation Loc = TSI->getTypeLoc().getBeginLoc();
Diag(Loc, diag::warn_auto_var_is_id) << VN << Range;
}
return DeducedType;
}
bool Sema::DeduceVariableDeclarationType(VarDecl *VDecl, bool DirectInit,
Expr *Init) {
assert(!Init || !Init->containsErrors());
QualType DeducedType = deduceVarTypeFromInitializer(
VDecl, VDecl->getDeclName(), VDecl->getType(), VDecl->getTypeSourceInfo(),
VDecl->getSourceRange(), DirectInit, Init);
if (DeducedType.isNull()) {
VDecl->setInvalidDecl();
return true;
}
VDecl->setType(DeducedType);
assert(VDecl->isLinkageValid());
// In ARC, infer lifetime.
if (getLangOpts().ObjCAutoRefCount && ObjC().inferObjCARCLifetime(VDecl))
VDecl->setInvalidDecl();
if (getLangOpts().OpenCL)
deduceOpenCLAddressSpace(VDecl);
if (getLangOpts().HLSL)
HLSL().deduceAddressSpace(VDecl);
// If this is a redeclaration, check that the type we just deduced matches
// the previously declared type.
if (VarDecl *Old = VDecl->getPreviousDecl()) {
// We never need to merge the type, because we cannot form an incomplete
// array of auto, nor deduce such a type.
MergeVarDeclTypes(VDecl, Old, /*MergeTypeWithPrevious*/ false);
}
// Check the deduced type is valid for a variable declaration.
CheckVariableDeclarationType(VDecl);
return VDecl->isInvalidDecl();
}
void Sema::checkNonTrivialCUnionInInitializer(const Expr *Init,
SourceLocation Loc) {
if (auto *EWC = dyn_cast<ExprWithCleanups>(Init))
Init = EWC->getSubExpr();
if (auto *CE = dyn_cast<ConstantExpr>(Init))
Init = CE->getSubExpr();
QualType InitType = Init->getType();
assert((InitType.hasNonTrivialToPrimitiveDefaultInitializeCUnion() ||
InitType.hasNonTrivialToPrimitiveCopyCUnion()) &&
"shouldn't be called if type doesn't have a non-trivial C struct");
if (auto *ILE = dyn_cast<InitListExpr>(Init)) {
for (auto *I : ILE->inits()) {
if (!I->getType().hasNonTrivialToPrimitiveDefaultInitializeCUnion() &&
!I->getType().hasNonTrivialToPrimitiveCopyCUnion())
continue;
SourceLocation SL = I->getExprLoc();
checkNonTrivialCUnionInInitializer(I, SL.isValid() ? SL : Loc);
}
return;
}
if (isa<ImplicitValueInitExpr>(Init)) {
if (InitType.hasNonTrivialToPrimitiveDefaultInitializeCUnion())
checkNonTrivialCUnion(InitType, Loc,
NonTrivialCUnionContext::DefaultInitializedObject,
NTCUK_Init);
} else {
// Assume all other explicit initializers involving copying some existing
// object.
// TODO: ignore any explicit initializers where we can guarantee
// copy-elision.
if (InitType.hasNonTrivialToPrimitiveCopyCUnion())
checkNonTrivialCUnion(InitType, Loc, NonTrivialCUnionContext::CopyInit,
NTCUK_Copy);
}
}
namespace {
bool shouldIgnoreForRecordTriviality(const FieldDecl *FD) {
// Ignore unavailable fields. A field can be marked as unavailable explicitly
// in the source code or implicitly by the compiler if it is in a union
// defined in a system header and has non-trivial ObjC ownership
// qualifications. We don't want those fields to participate in determining
// whether the containing union is non-trivial.
return FD->hasAttr<UnavailableAttr>();
}
struct DiagNonTrivalCUnionDefaultInitializeVisitor
: DefaultInitializedTypeVisitor<DiagNonTrivalCUnionDefaultInitializeVisitor,
void> {
using Super =
DefaultInitializedTypeVisitor<DiagNonTrivalCUnionDefaultInitializeVisitor,
void>;
DiagNonTrivalCUnionDefaultInitializeVisitor(
QualType OrigTy, SourceLocation OrigLoc,
NonTrivialCUnionContext UseContext, Sema &S)
: OrigTy(OrigTy), OrigLoc(OrigLoc), UseContext(UseContext), S(S) {}
void visitWithKind(QualType::PrimitiveDefaultInitializeKind PDIK, QualType QT,
const FieldDecl *FD, bool InNonTrivialUnion) {
if (const auto *AT = S.Context.getAsArrayType(QT))
return this->asDerived().visit(S.Context.getBaseElementType(AT), FD,
InNonTrivialUnion);
return Super::visitWithKind(PDIK, QT, FD, InNonTrivialUnion);
}
void visitARCStrong(QualType QT, const FieldDecl *FD,
bool InNonTrivialUnion) {
if (InNonTrivialUnion)
S.Diag(FD->getLocation(), diag::note_non_trivial_c_union)
<< 1 << 0 << QT << FD->getName();
}
void visitARCWeak(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {
if (InNonTrivialUnion)
S.Diag(FD->getLocation(), diag::note_non_trivial_c_union)
<< 1 << 0 << QT << FD->getName();
}
void visitStruct(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {
const auto *RD = QT->castAsRecordDecl();
if (RD->isUnion()) {
if (OrigLoc.isValid()) {
bool IsUnion = false;
if (auto *OrigRD = OrigTy->getAsRecordDecl())
IsUnion = OrigRD->isUnion();
S.Diag(OrigLoc, diag::err_non_trivial_c_union_in_invalid_context)
<< 0 << OrigTy << IsUnion << UseContext;
// Reset OrigLoc so that this diagnostic is emitted only once.
OrigLoc = SourceLocation();
}
InNonTrivialUnion = true;
}
if (InNonTrivialUnion)
S.Diag(RD->getLocation(), diag::note_non_trivial_c_union)
<< 0 << 0 << QT.getUnqualifiedType() << "";
for (const FieldDecl *FD : RD->fields())
if (!shouldIgnoreForRecordTriviality(FD))
asDerived().visit(FD->getType(), FD, InNonTrivialUnion);
}
void visitTrivial(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {}
// The non-trivial C union type or the struct/union type that contains a
// non-trivial C union.
QualType OrigTy;
SourceLocation OrigLoc;
NonTrivialCUnionContext UseContext;
Sema &S;
};
struct DiagNonTrivalCUnionDestructedTypeVisitor
: DestructedTypeVisitor<DiagNonTrivalCUnionDestructedTypeVisitor, void> {
using Super =
DestructedTypeVisitor<DiagNonTrivalCUnionDestructedTypeVisitor, void>;
DiagNonTrivalCUnionDestructedTypeVisitor(QualType OrigTy,
SourceLocation OrigLoc,
NonTrivialCUnionContext UseContext,
Sema &S)
: OrigTy(OrigTy), OrigLoc(OrigLoc), UseContext(UseContext), S(S) {}
void visitWithKind(QualType::DestructionKind DK, QualType QT,
const FieldDecl *FD, bool InNonTrivialUnion) {
if (const auto *AT = S.Context.getAsArrayType(QT))
return this->asDerived().visit(S.Context.getBaseElementType(AT), FD,
InNonTrivialUnion);
return Super::visitWithKind(DK, QT, FD, InNonTrivialUnion);
}
void visitARCStrong(QualType QT, const FieldDecl *FD,
bool InNonTrivialUnion) {
if (InNonTrivialUnion)
S.Diag(FD->getLocation(), diag::note_non_trivial_c_union)
<< 1 << 1 << QT << FD->getName();
}
void visitARCWeak(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {
if (InNonTrivialUnion)
S.Diag(FD->getLocation(), diag::note_non_trivial_c_union)
<< 1 << 1 << QT << FD->getName();
}
void visitStruct(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {
const auto *RD = QT->castAsRecordDecl();
if (RD->isUnion()) {
if (OrigLoc.isValid()) {
bool IsUnion = false;
if (auto *OrigRD = OrigTy->getAsRecordDecl())
IsUnion = OrigRD->isUnion();
S.Diag(OrigLoc, diag::err_non_trivial_c_union_in_invalid_context)
<< 1 << OrigTy << IsUnion << UseContext;
// Reset OrigLoc so that this diagnostic is emitted only once.
OrigLoc = SourceLocation();
}
InNonTrivialUnion = true;
}
if (InNonTrivialUnion)
S.Diag(RD->getLocation(), diag::note_non_trivial_c_union)
<< 0 << 1 << QT.getUnqualifiedType() << "";
for (const FieldDecl *FD : RD->fields())
if (!shouldIgnoreForRecordTriviality(FD))
asDerived().visit(FD->getType(), FD, InNonTrivialUnion);
}
void visitTrivial(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {}
void visitCXXDestructor(QualType QT, const FieldDecl *FD,
bool InNonTrivialUnion) {}
// The non-trivial C union type or the struct/union type that contains a
// non-trivial C union.
QualType OrigTy;
SourceLocation OrigLoc;
NonTrivialCUnionContext UseContext;
Sema &S;
};
struct DiagNonTrivalCUnionCopyVisitor
: CopiedTypeVisitor<DiagNonTrivalCUnionCopyVisitor, false, void> {
using Super = CopiedTypeVisitor<DiagNonTrivalCUnionCopyVisitor, false, void>;
DiagNonTrivalCUnionCopyVisitor(QualType OrigTy, SourceLocation OrigLoc,
NonTrivialCUnionContext UseContext, Sema &S)
: OrigTy(OrigTy), OrigLoc(OrigLoc), UseContext(UseContext), S(S) {}
void visitWithKind(QualType::PrimitiveCopyKind PCK, QualType QT,
const FieldDecl *FD, bool InNonTrivialUnion) {
if (const auto *AT = S.Context.getAsArrayType(QT))
return this->asDerived().visit(S.Context.getBaseElementType(AT), FD,
InNonTrivialUnion);
return Super::visitWithKind(PCK, QT, FD, InNonTrivialUnion);
}
void visitARCStrong(QualType QT, const FieldDecl *FD,
bool InNonTrivialUnion) {
if (InNonTrivialUnion)
S.Diag(FD->getLocation(), diag::note_non_trivial_c_union)
<< 1 << 2 << QT << FD->getName();
}
void visitARCWeak(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {
if (InNonTrivialUnion)
S.Diag(FD->getLocation(), diag::note_non_trivial_c_union)
<< 1 << 2 << QT << FD->getName();
}
void visitStruct(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {
const auto *RD = QT->castAsRecordDecl();
if (RD->isUnion()) {
if (OrigLoc.isValid()) {
bool IsUnion = false;
if (auto *OrigRD = OrigTy->getAsRecordDecl())
IsUnion = OrigRD->isUnion();
S.Diag(OrigLoc, diag::err_non_trivial_c_union_in_invalid_context)
<< 2 << OrigTy << IsUnion << UseContext;
// Reset OrigLoc so that this diagnostic is emitted only once.
OrigLoc = SourceLocation();
}
InNonTrivialUnion = true;
}
if (InNonTrivialUnion)
S.Diag(RD->getLocation(), diag::note_non_trivial_c_union)
<< 0 << 2 << QT.getUnqualifiedType() << "";
for (const FieldDecl *FD : RD->fields())
if (!shouldIgnoreForRecordTriviality(FD))
asDerived().visit(FD->getType(), FD, InNonTrivialUnion);
}
void visitPtrAuth(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {
if (InNonTrivialUnion)
S.Diag(FD->getLocation(), diag::note_non_trivial_c_union)
<< 1 << 2 << QT << FD->getName();
}
void preVisit(QualType::PrimitiveCopyKind PCK, QualType QT,
const FieldDecl *FD, bool InNonTrivialUnion) {}
void visitTrivial(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {}
void visitVolatileTrivial(QualType QT, const FieldDecl *FD,
bool InNonTrivialUnion) {}
// The non-trivial C union type or the struct/union type that contains a
// non-trivial C union.
QualType OrigTy;
SourceLocation OrigLoc;
NonTrivialCUnionContext UseContext;
Sema &S;
};
} // namespace
void Sema::checkNonTrivialCUnion(QualType QT, SourceLocation Loc,
NonTrivialCUnionContext UseContext,
unsigned NonTrivialKind) {
assert((QT.hasNonTrivialToPrimitiveDefaultInitializeCUnion() ||
QT.hasNonTrivialToPrimitiveDestructCUnion() ||
QT.hasNonTrivialToPrimitiveCopyCUnion()) &&
"shouldn't be called if type doesn't have a non-trivial C union");
if ((NonTrivialKind & NTCUK_Init) &&
QT.hasNonTrivialToPrimitiveDefaultInitializeCUnion())
DiagNonTrivalCUnionDefaultInitializeVisitor(QT, Loc, UseContext, *this)
.visit(QT, nullptr, false);
if ((NonTrivialKind & NTCUK_Destruct) &&
QT.hasNonTrivialToPrimitiveDestructCUnion())
DiagNonTrivalCUnionDestructedTypeVisitor(QT, Loc, UseContext, *this)
.visit(QT, nullptr, false);
if ((NonTrivialKind & NTCUK_Copy) && QT.hasNonTrivialToPrimitiveCopyCUnion())
DiagNonTrivalCUnionCopyVisitor(QT, Loc, UseContext, *this)
.visit(QT, nullptr, false);
}
bool Sema::GloballyUniqueObjectMightBeAccidentallyDuplicated(
const VarDecl *Dcl) {
if (!getLangOpts().CPlusPlus)
return false;
// We only need to warn if the definition is in a header file, so wait to
// diagnose until we've seen the definition.
if (!Dcl->isThisDeclarationADefinition())
return false;
// If an object is defined in a source file, its definition can't get
// duplicated since it will never appear in more than one TU.
if (Dcl->getASTContext().getSourceManager().isInMainFile(Dcl->getLocation()))
return false;
// If the variable we're looking at is a static local, then we actually care
// about the properties of the function containing it.
const ValueDecl *Target = Dcl;
// VarDecls and FunctionDecls have different functions for checking
// inline-ness, and whether they were originally templated, so we have to
// call the appropriate functions manually.
bool TargetIsInline = Dcl->isInline();
bool TargetWasTemplated =
Dcl->getTemplateSpecializationKind() != TSK_Undeclared;
// Update the Target and TargetIsInline property if necessary
if (Dcl->isStaticLocal()) {
const DeclContext *Ctx = Dcl->getDeclContext();
if (!Ctx)
return false;
const FunctionDecl *FunDcl =
dyn_cast_if_present<FunctionDecl>(Ctx->getNonClosureAncestor());
if (!FunDcl)
return false;
Target = FunDcl;
// IsInlined() checks for the C++ inline property
TargetIsInline = FunDcl->isInlined();
TargetWasTemplated =
FunDcl->getTemplateSpecializationKind() != TSK_Undeclared;
}
// Non-inline functions/variables can only legally appear in one TU
// unless they were part of a template. Unfortunately, making complex
// template instantiations visible is infeasible in practice, since
// everything the template depends on also has to be visible. To avoid
// giving impractical-to-fix warnings, don't warn if we're inside
// something that was templated, even on inline stuff.
if (!TargetIsInline || TargetWasTemplated)
return false;
// If the object isn't hidden, the dynamic linker will prevent duplication.
clang::LinkageInfo Lnk = Target->getLinkageAndVisibility();
// The target is "hidden" (from the dynamic linker) if:
// 1. On posix, it has hidden visibility, or
// 2. On windows, it has no import/export annotation, and neither does the
// class which directly contains it.
if (Context.getTargetInfo().shouldDLLImportComdatSymbols()) {
if (Target->hasAttr<DLLExportAttr>() || Target->hasAttr<DLLImportAttr>())
return false;
// If the variable isn't directly annotated, check to see if it's a member
// of an annotated class.
const CXXRecordDecl *Ctx =
dyn_cast<CXXRecordDecl>(Target->getDeclContext());
if (Ctx && (Ctx->hasAttr<DLLExportAttr>() || Ctx->hasAttr<DLLImportAttr>()))
return false;
} else if (Lnk.getVisibility() != HiddenVisibility) {
// Posix case
return false;
}
// If the obj doesn't have external linkage, it's supposed to be duplicated.
if (!isExternalFormalLinkage(Lnk.getLinkage()))
return false;
return true;
}
// Determine whether the object seems mutable for the purpose of diagnosing
// possible unique object duplication, i.e. non-const-qualified, and
// not an always-constant type like a function.
// Not perfect: doesn't account for mutable members, for example, or
// elements of container types.
// For nested pointers, any individual level being non-const is sufficient.
static bool looksMutable(QualType T, const ASTContext &Ctx) {
T = T.getNonReferenceType();
if (T->isFunctionType())
return false;
if (!T.isConstant(Ctx))
return true;
if (T->isPointerType())
return looksMutable(T->getPointeeType(), Ctx);
return false;
}
void Sema::DiagnoseUniqueObjectDuplication(const VarDecl *VD) {
// If this object has external linkage and hidden visibility, it might be
// duplicated when built into a shared library, which causes problems if it's
// mutable (since the copies won't be in sync) or its initialization has side
// effects (since it will run once per copy instead of once globally).
// Don't diagnose if we're inside a template, because it's not practical to
// fix the warning in most cases.
if (!VD->isTemplated() &&
GloballyUniqueObjectMightBeAccidentallyDuplicated(VD)) {
QualType Type = VD->getType();
if (looksMutable(Type, VD->getASTContext())) {
Diag(VD->getLocation(), diag::warn_possible_object_duplication_mutable)
<< VD << Context.getTargetInfo().shouldDLLImportComdatSymbols();
}
// To keep false positives low, only warn if we're certain that the
// initializer has side effects. Don't warn on operator new, since a mutable
// pointer will trigger the previous warning, and an immutable pointer
// getting duplicated just results in a little extra memory usage.
const Expr *Init = VD->getAnyInitializer();
if (Init &&
Init->HasSideEffects(VD->getASTContext(),
/*IncludePossibleEffects=*/false) &&
!isa<CXXNewExpr>(Init->IgnoreParenImpCasts())) {
Diag(Init->getExprLoc(), diag::warn_possible_object_duplication_init)
<< VD << Context.getTargetInfo().shouldDLLImportComdatSymbols();
}
}
}
void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
// If there is no declaration, there was an error parsing it. Just ignore
// the initializer.
if (!RealDecl) {
return;
}
if (auto *Method = dyn_cast<CXXMethodDecl>(RealDecl)) {
if (!Method->isInvalidDecl()) {
// Pure-specifiers are handled in ActOnPureSpecifier.
Diag(Method->getLocation(), diag::err_member_function_initialization)
<< Method->getDeclName() << Init->getSourceRange();
Method->setInvalidDecl();
}
return;
}
VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl);
if (!VDecl) {
assert(!isa<FieldDecl>(RealDecl) && "field init shouldn't get here");
Diag(RealDecl->getLocation(), diag::err_illegal_initializer);
RealDecl->setInvalidDecl();
return;
}
if (VDecl->isInvalidDecl()) {
ExprResult Recovery =
CreateRecoveryExpr(Init->getBeginLoc(), Init->getEndLoc(), {Init});
if (Expr *E = Recovery.get())
VDecl->setInit(E);
return;
}
// WebAssembly tables can't be used to initialise a variable.
if (!Init->getType().isNull() && Init->getType()->isWebAssemblyTableType()) {
Diag(Init->getExprLoc(), diag::err_wasm_table_art) << 0;
VDecl->setInvalidDecl();
return;
}
// C++11 [decl.spec.auto]p6. Deduce the type which 'auto' stands in for.
if (VDecl->getType()->isUndeducedType()) {
if (Init->containsErrors()) {
// Invalidate the decl as we don't know the type for recovery-expr yet.
RealDecl->setInvalidDecl();
VDecl->setInit(Init);
return;
}
if (DeduceVariableDeclarationType(VDecl, DirectInit, Init))
return;
}
// dllimport cannot be used on variable definitions.
if (VDecl->hasAttr<DLLImportAttr>() && !VDecl->isStaticDataMember()) {
Diag(VDecl->getLocation(), diag::err_attribute_dllimport_data_definition);
VDecl->setInvalidDecl();
return;
}
// C99 6.7.8p5. If the declaration of an identifier has block scope, and
// the identifier has external or internal linkage, the declaration shall
// have no initializer for the identifier.
// C++14 [dcl.init]p5 is the same restriction for C++.
if (VDecl->isLocalVarDecl() && VDecl->hasExternalStorage()) {
Diag(VDecl->getLocation(), diag::err_block_extern_cant_init);
VDecl->setInvalidDecl();
return;
}
if (!VDecl->getType()->isDependentType()) {
// A definition must end up with a complete type, which means it must be
// complete with the restriction that an array type might be completed by
// the initializer; note that later code assumes this restriction.
QualType BaseDeclType = VDecl->getType();
if (const ArrayType *Array = Context.getAsIncompleteArrayType(BaseDeclType))
BaseDeclType = Array->getElementType();
if (RequireCompleteType(VDecl->getLocation(), BaseDeclType,
diag::err_typecheck_decl_incomplete_type)) {
RealDecl->setInvalidDecl();
return;
}
// The variable can not have an abstract class type.
if (RequireNonAbstractType(VDecl->getLocation(), VDecl->getType(),
diag::err_abstract_type_in_decl,
AbstractVariableType))
VDecl->setInvalidDecl();
}
// C++ [module.import/6] external definitions are not permitted in header
// units.
if (getLangOpts().CPlusPlusModules && currentModuleIsHeaderUnit() &&
!VDecl->isInvalidDecl() && VDecl->isThisDeclarationADefinition() &&
VDecl->getFormalLinkage() == Linkage::External && !VDecl->isInline() &&
!VDecl->isTemplated() && !isa<VarTemplateSpecializationDecl>(VDecl) &&
!VDecl->getInstantiatedFromStaticDataMember()) {
Diag(VDecl->getLocation(), diag::err_extern_def_in_header_unit);
VDecl->setInvalidDecl();
}
// If adding the initializer will turn this declaration into a definition,
// and we already have a definition for this variable, diagnose or otherwise
// handle the situation.
if (VarDecl *Def = VDecl->getDefinition())
if (Def != VDecl &&
(!VDecl->isStaticDataMember() || VDecl->isOutOfLine()) &&
!VDecl->isThisDeclarationADemotedDefinition() &&
checkVarDeclRedefinition(Def, VDecl))
return;
if (getLangOpts().CPlusPlus) {
// C++ [class.static.data]p4
// If a static data member is of const integral or const
// enumeration type, its declaration in the class definition can
// specify a constant-initializer which shall be an integral
// constant expression (5.19). In that case, the member can appear
// in integral constant expressions. The member shall still be
// defined in a namespace scope if it is used in the program and the
// namespace scope definition shall not contain an initializer.
//
// We already performed a redefinition check above, but for static
// data members we also need to check whether there was an in-class
// declaration with an initializer.
if (VDecl->isStaticDataMember() && VDecl->getCanonicalDecl()->hasInit()) {
Diag(Init->getExprLoc(), diag::err_static_data_member_reinitialization)
<< VDecl->getDeclName();
Diag(VDecl->getCanonicalDecl()->getInit()->getExprLoc(),
diag::note_previous_initializer)
<< 0;
return;
}
if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer)) {
VDecl->setInvalidDecl();
return;
}
}
// If the variable has an initializer and local storage, check whether
// anything jumps over the initialization.
if (VDecl->hasLocalStorage())
setFunctionHasBranchProtectedScope();
// OpenCL 1.1 6.5.2: "Variables allocated in the __local address space inside
// a kernel function cannot be initialized."
if (VDecl->getType().getAddressSpace() == LangAS::opencl_local) {
Diag(VDecl->getLocation(), diag::err_local_cant_init);
VDecl->setInvalidDecl();
return;
}
// The LoaderUninitialized attribute acts as a definition (of undef).
if (VDecl->hasAttr<LoaderUninitializedAttr>()) {
Diag(VDecl->getLocation(), diag::err_loader_uninitialized_cant_init);
VDecl->setInvalidDecl();
return;
}
if (getLangOpts().HLSL)
if (!HLSL().handleInitialization(VDecl, Init))
return;
// Get the decls type and save a reference for later, since
// CheckInitializerTypes may change it.
QualType DclT = VDecl->getType(), SavT = DclT;
// Expressions default to 'id' when we're in a debugger
// and we are assigning it to a variable of Objective-C pointer type.
if (getLangOpts().DebuggerCastResultToId && DclT->isObjCObjectPointerType() &&
Init->getType() == Context.UnknownAnyTy) {
ExprResult Result = forceUnknownAnyToType(Init, Context.getObjCIdType());
if (!Result.isUsable()) {
VDecl->setInvalidDecl();
return;
}
Init = Result.get();
}
// Perform the initialization.
bool InitializedFromParenListExpr = false;
bool IsParenListInit = false;
if (!VDecl->isInvalidDecl()) {
InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl);
InitializationKind Kind = InitializationKind::CreateForInit(
VDecl->getLocation(), DirectInit, Init);
MultiExprArg Args = Init;
if (auto *CXXDirectInit = dyn_cast<ParenListExpr>(Init)) {
Args =
MultiExprArg(CXXDirectInit->getExprs(), CXXDirectInit->getNumExprs());
InitializedFromParenListExpr = true;
} else if (auto *CXXDirectInit = dyn_cast<CXXParenListInitExpr>(Init)) {
Args = CXXDirectInit->getInitExprs();
InitializedFromParenListExpr = true;
}
InitializationSequence InitSeq(*this, Entity, Kind, Args,
/*TopLevelOfInitList=*/false,
/*TreatUnavailableAsInvalid=*/false);
ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT);
if (!Result.isUsable()) {
// If the provided initializer fails to initialize the var decl,
// we attach a recovery expr for better recovery.
auto RecoveryExpr =
CreateRecoveryExpr(Init->getBeginLoc(), Init->getEndLoc(), Args);
if (RecoveryExpr.get())
VDecl->setInit(RecoveryExpr.get());
// In general, for error recovery purposes, the initializer doesn't play
// part in the valid bit of the declaration. There are a few exceptions:
// 1) if the var decl has a deduced auto type, and the type cannot be
// deduced by an invalid initializer;
// 2) if the var decl is a decomposition decl with a non-deduced type,
// and the initialization fails (e.g. `int [a] = {1, 2};`);
// Case 1) was already handled elsewhere.
if (isa<DecompositionDecl>(VDecl)) // Case 2)
VDecl->setInvalidDecl();
return;
}
Init = Result.getAs<Expr>();
IsParenListInit = !InitSeq.steps().empty() &&
InitSeq.step_begin()->Kind ==
InitializationSequence::SK_ParenthesizedListInit;
QualType VDeclType = VDecl->getType();
if (!Init->getType().isNull() && !Init->getType()->isDependentType() &&
!VDeclType->isDependentType() &&
Context.getAsIncompleteArrayType(VDeclType) &&
Context.getAsIncompleteArrayType(Init->getType())) {
// Bail out if it is not possible to deduce array size from the
// initializer.
Diag(VDecl->getLocation(), diag::err_typecheck_decl_incomplete_type)
<< VDeclType;
VDecl->setInvalidDecl();
return;
}
}
// Check for self-references within variable initializers.
// Variables declared within a function/method body (except for references)
// are handled by a dataflow analysis.
// This is undefined behavior in C++, but valid in C.
if (getLangOpts().CPlusPlus)
if (!VDecl->hasLocalStorage() || VDecl->getType()->isRecordType() ||
VDecl->getType()->isReferenceType())
CheckSelfReference(*this, RealDecl, Init, DirectInit);
// If the type changed, it means we had an incomplete type that was
// completed by the initializer. For example:
// int ary[] = { 1, 3, 5 };
// "ary" transitions from an IncompleteArrayType to a ConstantArrayType.
if (!VDecl->isInvalidDecl() && (DclT != SavT))
VDecl->setType(DclT);
if (!VDecl->isInvalidDecl()) {
checkUnsafeAssigns(VDecl->getLocation(), VDecl->getType(), Init);
if (VDecl->hasAttr<BlocksAttr>())
ObjC().checkRetainCycles(VDecl, Init);
// It is safe to assign a weak reference into a strong variable.
// Although this code can still have problems:
// id x = self.weakProp;
// id y = self.weakProp;
// we do not warn to warn spuriously when 'x' and 'y' are on separate
// paths through the function. This should be revisited if
// -Wrepeated-use-of-weak is made flow-sensitive.
if (FunctionScopeInfo *FSI = getCurFunction())
if ((VDecl->getType().getObjCLifetime() == Qualifiers::OCL_Strong ||
VDecl->getType().isNonWeakInMRRWithObjCWeak(Context)) &&
!Diags.isIgnored(diag::warn_arc_repeated_use_of_weak,
Init->getBeginLoc()))
FSI->markSafeWeakUse(Init);
}
// The initialization is usually a full-expression.
//
// FIXME: If this is a braced initialization of an aggregate, it is not
// an expression, and each individual field initializer is a separate
// full-expression. For instance, in:
//
// struct Temp { ~Temp(); };
// struct S { S(Temp); };
// struct T { S a, b; } t = { Temp(), Temp() }
//
// we should destroy the first Temp before constructing the second.
ExprResult Result =
ActOnFinishFullExpr(Init, VDecl->getLocation(),
/*DiscardedValue*/ false, VDecl->isConstexpr());
if (!Result.isUsable()) {
VDecl->setInvalidDecl();
return;
}
Init = Result.get();
// Attach the initializer to the decl.
VDecl->setInit(Init);
if (VDecl->isLocalVarDecl()) {
// Don't check the initializer if the declaration is malformed.
if (VDecl->isInvalidDecl()) {
// do nothing
// OpenCL v1.2 s6.5.3: __constant locals must be constant-initialized.
// This is true even in C++ for OpenCL.
} else if (VDecl->getType().getAddressSpace() == LangAS::opencl_constant) {
CheckForConstantInitializer(Init);
// Otherwise, C++ does not restrict the initializer.
} else if (getLangOpts().CPlusPlus) {
// do nothing
// C99 6.7.8p4: All the expressions in an initializer for an object that has
// static storage duration shall be constant expressions or string literals.
} else if (VDecl->getStorageClass() == SC_Static) {
CheckForConstantInitializer(Init);
// C89 is stricter than C99 for aggregate initializers.
// C89 6.5.7p3: All the expressions [...] in an initializer list
// for an object that has aggregate or union type shall be
// constant expressions.
} else if (!getLangOpts().C99 && VDecl->getType()->isAggregateType() &&
isa<InitListExpr>(Init)) {
CheckForConstantInitializer(Init, diag::ext_aggregate_init_not_constant);
}
if (auto *E = dyn_cast<ExprWithCleanups>(Init))
if (auto *BE = dyn_cast<BlockExpr>(E->getSubExpr()->IgnoreParens()))
if (VDecl->hasLocalStorage())
BE->getBlockDecl()->setCanAvoidCopyToHeap();
} else if (VDecl->isStaticDataMember() && !VDecl->isInline() &&
VDecl->getLexicalDeclContext()->isRecord()) {
// This is an in-class initialization for a static data member, e.g.,
//
// struct S {
// static const int value = 17;
// };
// C++ [class.mem]p4:
// A member-declarator can contain a constant-initializer only
// if it declares a static member (9.4) of const integral or
// const enumeration type, see 9.4.2.
//
// C++11 [class.static.data]p3:
// If a non-volatile non-inline const static data member is of integral
// or enumeration type, its declaration in the class definition can
// specify a brace-or-equal-initializer in which every initializer-clause
// that is an assignment-expression is a constant expression. A static
// data member of literal type can be declared in the class definition
// with the constexpr specifier; if so, its declaration shall specify a
// brace-or-equal-initializer in which every initializer-clause that is
// an assignment-expression is a constant expression.
// Do nothing on dependent types.
if (DclT->isDependentType()) {
// Allow any 'static constexpr' members, whether or not they are of literal
// type. We separately check that every constexpr variable is of literal
// type.
} else if (VDecl->isConstexpr()) {
// Require constness.
} else if (!DclT.isConstQualified()) {
Diag(VDecl->getLocation(), diag::err_in_class_initializer_non_const)
<< Init->getSourceRange();
VDecl->setInvalidDecl();
// We allow integer constant expressions in all cases.
} else if (DclT->isIntegralOrEnumerationType()) {
if (getLangOpts().CPlusPlus11 && DclT.isVolatileQualified())
// In C++11, a non-constexpr const static data member with an
// in-class initializer cannot be volatile.
Diag(VDecl->getLocation(), diag::err_in_class_initializer_volatile);
// We allow foldable floating-point constants as an extension.
} else if (DclT->isFloatingType()) { // also permits complex, which is ok
// In C++98, this is a GNU extension. In C++11, it is not, but we support
// it anyway and provide a fixit to add the 'constexpr'.
if (getLangOpts().CPlusPlus11) {
Diag(VDecl->getLocation(),
diag::ext_in_class_initializer_float_type_cxx11)
<< DclT << Init->getSourceRange();
Diag(VDecl->getBeginLoc(),
diag::note_in_class_initializer_float_type_cxx11)
<< FixItHint::CreateInsertion(VDecl->getBeginLoc(), "constexpr ");
} else {
Diag(VDecl->getLocation(), diag::ext_in_class_initializer_float_type)
<< DclT << Init->getSourceRange();
if (!Init->isValueDependent() && !Init->isEvaluatable(Context)) {
Diag(Init->getExprLoc(), diag::err_in_class_initializer_non_constant)
<< Init->getSourceRange();
VDecl->setInvalidDecl();
}
}
// Suggest adding 'constexpr' in C++11 for literal types.
} else if (getLangOpts().CPlusPlus11 && DclT->isLiteralType(Context)) {
Diag(VDecl->getLocation(), diag::err_in_class_initializer_literal_type)
<< DclT << Init->getSourceRange()
<< FixItHint::CreateInsertion(VDecl->getBeginLoc(), "constexpr ");
VDecl->setConstexpr(true);
} else {
Diag(VDecl->getLocation(), diag::err_in_class_initializer_bad_type)
<< DclT << Init->getSourceRange();
VDecl->setInvalidDecl();
}
} else if (VDecl->isFileVarDecl()) {
// In C, extern is typically used to avoid tentative definitions when
// declaring variables in headers, but adding an initializer makes it a
// definition. This is somewhat confusing, so GCC and Clang both warn on it.
// In C++, extern is often used to give implicitly static const variables
// external linkage, so don't warn in that case. If selectany is present,
// this might be header code intended for C and C++ inclusion, so apply the
// C++ rules.
if (VDecl->getStorageClass() == SC_Extern &&
((!getLangOpts().CPlusPlus && !VDecl->hasAttr<SelectAnyAttr>()) ||
!Context.getBaseElementType(VDecl->getType()).isConstQualified()) &&
!(getLangOpts().CPlusPlus && VDecl->isExternC()) &&
!isTemplateInstantiation(VDecl->getTemplateSpecializationKind()))
Diag(VDecl->getLocation(), diag::warn_extern_init);
// In Microsoft C++ mode, a const variable defined in namespace scope has
// external linkage by default if the variable is declared with
// __declspec(dllexport).
if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
getLangOpts().CPlusPlus && VDecl->getType().isConstQualified() &&
VDecl->hasAttr<DLLExportAttr>() && VDecl->getDefinition())
VDecl->setStorageClass(SC_Extern);
// C99 6.7.8p4. All file scoped initializers need to be constant.
// Avoid duplicate diagnostics for constexpr variables.
if (!getLangOpts().CPlusPlus && !VDecl->isInvalidDecl() &&
!VDecl->isConstexpr())
CheckForConstantInitializer(Init);
}
QualType InitType = Init->getType();
if (!InitType.isNull() &&
(InitType.hasNonTrivialToPrimitiveDefaultInitializeCUnion() ||
InitType.hasNonTrivialToPrimitiveCopyCUnion()))
checkNonTrivialCUnionInInitializer(Init, Init->getExprLoc());
// We will represent direct-initialization similarly to copy-initialization:
// int x(1); -as-> int x = 1;
// ClassType x(a,b,c); -as-> ClassType x = ClassType(a,b,c);
//
// Clients that want to distinguish between the two forms, can check for
// direct initializer using VarDecl::getInitStyle().
// A major benefit is that clients that don't particularly care about which
// exactly form was it (like the CodeGen) can handle both cases without
// special case code.
// C++ 8.5p11:
// The form of initialization (using parentheses or '=') matters
// when the entity being initialized has class type.
if (InitializedFromParenListExpr) {
assert(DirectInit && "Call-style initializer must be direct init.");
VDecl->setInitStyle(IsParenListInit ? VarDecl::ParenListInit
: VarDecl::CallInit);
} else if (DirectInit) {
// This must be list-initialization. No other way is direct-initialization.
VDecl->setInitStyle(VarDecl::ListInit);
}
if (LangOpts.OpenMP &&
(LangOpts.OpenMPIsTargetDevice || !LangOpts.OMPTargetTriples.empty()) &&
VDecl->isFileVarDecl())
DeclsToCheckForDeferredDiags.insert(VDecl);
CheckCompleteVariableDeclaration(VDecl);
if (LangOpts.OpenACC && !InitType.isNull())
OpenACC().ActOnVariableInit(VDecl, InitType);
}
void Sema::ActOnInitializerError(Decl *D) {
// Our main concern here is re-establishing invariants like "a
// variable's type is either dependent or complete".
if (!D || D->isInvalidDecl()) return;
VarDecl *VD = dyn_cast<VarDecl>(D);
if (!VD) return;
// Bindings are not usable if we can't make sense of the initializer.
if (auto *DD = dyn_cast<DecompositionDecl>(D))
for (auto *BD : DD->bindings())
BD->setInvalidDecl();
// Auto types are meaningless if we can't make sense of the initializer.
if (VD->getType()->isUndeducedType()) {
D->setInvalidDecl();
return;
}
QualType Ty = VD->getType();
if (Ty->isDependentType()) return;
// Require a complete type.
if (RequireCompleteType(VD->getLocation(),
Context.getBaseElementType(Ty),
diag::err_typecheck_decl_incomplete_type)) {
VD->setInvalidDecl();
return;
}
// Require a non-abstract type.
if (RequireNonAbstractType(VD->getLocation(), Ty,
diag::err_abstract_type_in_decl,
AbstractVariableType)) {
VD->setInvalidDecl();
return;
}
// Don't bother complaining about constructors or destructors,
// though.
}
void Sema::ActOnUninitializedDecl(Decl *RealDecl) {
// If there is no declaration, there was an error parsing it. Just ignore it.
if (!RealDecl)
return;
if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) {
QualType Type = Var->getType();
// C++1z [dcl.dcl]p1 grammar implies that an initializer is mandatory.
if (isa<DecompositionDecl>(RealDecl)) {
Diag(Var->getLocation(), diag::err_decomp_decl_requires_init) << Var;
Var->setInvalidDecl();
return;
}
if (Type->isUndeducedType() &&
DeduceVariableDeclarationType(Var, false, nullptr))
return;
// C++11 [class.static.data]p3: A static data member can be declared with
// the constexpr specifier; if so, its declaration shall specify
// a brace-or-equal-initializer.
// C++11 [dcl.constexpr]p1: The constexpr specifier shall be applied only to
// the definition of a variable [...] or the declaration of a static data
// member.
if (Var->isConstexpr() && !Var->isThisDeclarationADefinition() &&
!Var->isThisDeclarationADemotedDefinition()) {
if (Var->isStaticDataMember()) {
// C++1z removes the relevant rule; the in-class declaration is always
// a definition there.
if (!getLangOpts().CPlusPlus17 &&
!Context.getTargetInfo().getCXXABI().isMicrosoft()) {
Diag(Var->getLocation(),
diag::err_constexpr_static_mem_var_requires_init)
<< Var;
Var->setInvalidDecl();
return;
}
} else {
Diag(Var->getLocation(), diag::err_invalid_constexpr_var_decl);
Var->setInvalidDecl();
return;
}
}
// OpenCL v1.1 s6.5.3: variables declared in the constant address space must
// be initialized.
if (!Var->isInvalidDecl() &&
Var->getType().getAddressSpace() == LangAS::opencl_constant &&
Var->getStorageClass() != SC_Extern && !Var->getInit()) {
bool HasConstExprDefaultConstructor = false;
if (CXXRecordDecl *RD = Var->getType()->getAsCXXRecordDecl()) {
for (auto *Ctor : RD->ctors()) {
if (Ctor->isConstexpr() && Ctor->getNumParams() == 0 &&
Ctor->getMethodQualifiers().getAddressSpace() ==
LangAS::opencl_constant) {
HasConstExprDefaultConstructor = true;
}
}
}
if (!HasConstExprDefaultConstructor) {
Diag(Var->getLocation(), diag::err_opencl_constant_no_init);
Var->setInvalidDecl();
return;
}
}
// HLSL variable with the `vk::constant_id` attribute must be initialized.
if (!Var->isInvalidDecl() && Var->hasAttr<HLSLVkConstantIdAttr>()) {
Diag(Var->getLocation(), diag::err_specialization_const);
Var->setInvalidDecl();
return;
}
if (!Var->isInvalidDecl() && RealDecl->hasAttr<LoaderUninitializedAttr>()) {
if (Var->getStorageClass() == SC_Extern) {
Diag(Var->getLocation(), diag::err_loader_uninitialized_extern_decl)
<< Var;
Var->setInvalidDecl();
return;
}
if (RequireCompleteType(Var->getLocation(), Var->getType(),
diag::err_typecheck_decl_incomplete_type)) {
Var->setInvalidDecl();
return;
}
if (CXXRecordDecl *RD = Var->getType()->getAsCXXRecordDecl()) {
if (!RD->hasTrivialDefaultConstructor()) {
Diag(Var->getLocation(), diag::err_loader_uninitialized_trivial_ctor);
Var->setInvalidDecl();
return;
}
}
// The declaration is uninitialized, no need for further checks.
return;
}
VarDecl::DefinitionKind DefKind = Var->isThisDeclarationADefinition();
if (!Var->isInvalidDecl() && DefKind != VarDecl::DeclarationOnly &&
Var->getType().hasNonTrivialToPrimitiveDefaultInitializeCUnion())
checkNonTrivialCUnion(Var->getType(), Var->getLocation(),
NonTrivialCUnionContext::DefaultInitializedObject,
NTCUK_Init);
switch (DefKind) {
case VarDecl::Definition:
if (!Var->isStaticDataMember() || !Var->getAnyInitializer())
break;
// We have an out-of-line definition of a static data member
// that has an in-class initializer, so we type-check this like
// a declaration.
//
[[fallthrough]];
case VarDecl::DeclarationOnly:
// It's only a declaration.
// Block scope. C99 6.7p7: If an identifier for an object is
// declared with no linkage (C99 6.2.2p6), the type for the
// object shall be complete.
if (!Type->isDependentType() && Var->isLocalVarDecl() &&
!Var->hasLinkage() && !Var->isInvalidDecl() &&
RequireCompleteType(Var->getLocation(), Type,
diag::err_typecheck_decl_incomplete_type))
Var->setInvalidDecl();
// Make sure that the type is not abstract.
if (!Type->isDependentType() && !Var->isInvalidDecl() &&
RequireNonAbstractType(Var->getLocation(), Type,
diag::err_abstract_type_in_decl,
AbstractVariableType))
Var->setInvalidDecl();
if (!Type->isDependentType() && !Var->isInvalidDecl() &&
Var->getStorageClass() == SC_PrivateExtern) {
Diag(Var->getLocation(), diag::warn_private_extern);
Diag(Var->getLocation(), diag::note_private_extern);
}
if (Context.getTargetInfo().allowDebugInfoForExternalRef() &&
!Var->isInvalidDecl())
ExternalDeclarations.push_back(Var);
return;
case VarDecl::TentativeDefinition:
// File scope. C99 6.9.2p2: A declaration of an identifier for an
// object that has file scope without an initializer, and without a
// storage-class specifier or with the storage-class specifier "static",
// constitutes a tentative definition. Note: A tentative definition with
// external linkage is valid (C99 6.2.2p5).
if (!Var->isInvalidDecl()) {
if (const IncompleteArrayType *ArrayT
= Context.getAsIncompleteArrayType(Type)) {
if (RequireCompleteSizedType(
Var->getLocation(), ArrayT->getElementType(),
diag::err_array_incomplete_or_sizeless_type))
Var->setInvalidDecl();
}
if (Var->getStorageClass() == SC_Static) {
// C99 6.9.2p3: If the declaration of an identifier for an object is
// a tentative definition and has internal linkage (C99 6.2.2p3), the
// declared type shall not be an incomplete type.
// NOTE: code such as the following
// static struct s;
// struct s { int a; };
// is accepted by gcc. Hence here we issue a warning instead of
// an error and we do not invalidate the static declaration.
// NOTE: to avoid multiple warnings, only check the first declaration.
if (Var->isFirstDecl())
RequireCompleteType(Var->getLocation(), Type,
diag::ext_typecheck_decl_incomplete_type,
Type->isArrayType());
}
}
// Record the tentative definition; we're done.
if (!Var->isInvalidDecl())
TentativeDefinitions.push_back(Var);
return;
}
// Provide a specific diagnostic for uninitialized variable
// definitions with incomplete array type.
if (Type->isIncompleteArrayType()) {
if (Var->isConstexpr())
Diag(Var->getLocation(), diag::err_constexpr_var_requires_const_init)
<< Var;
else
Diag(Var->getLocation(),
diag::err_typecheck_incomplete_array_needs_initializer);
Var->setInvalidDecl();
return;
}
// Provide a specific diagnostic for uninitialized variable
// definitions with reference type.
if (Type->isReferenceType()) {
Diag(Var->getLocation(), diag::err_reference_var_requires_init)
<< Var << SourceRange(Var->getLocation(), Var->getLocation());
return;
}
// Do not attempt to type-check the default initializer for a
// variable with dependent type.
if (Type->isDependentType())
return;
if (Var->isInvalidDecl())
return;
if (!Var->hasAttr<AliasAttr>()) {
if (RequireCompleteType(Var->getLocation(),
Context.getBaseElementType(Type),
diag::err_typecheck_decl_incomplete_type)) {
Var->setInvalidDecl();
return;
}
} else {
return;
}
// The variable can not have an abstract class type.
if (RequireNonAbstractType(Var->getLocation(), Type,
diag::err_abstract_type_in_decl,
AbstractVariableType)) {
Var->setInvalidDecl();
return;
}
// In C, if the definition is const-qualified and has no initializer, it
// is left uninitialized unless it has static or thread storage duration.
if (!getLangOpts().CPlusPlus && Type.isConstQualified()) {
unsigned DiagID = diag::warn_default_init_const_unsafe;
if (Var->getStorageDuration() == SD_Static ||
Var->getStorageDuration() == SD_Thread)
DiagID = diag::warn_default_init_const;
bool EmitCppCompat = !Diags.isIgnored(
diag::warn_cxx_compat_hack_fake_diagnostic_do_not_emit,
Var->getLocation());
Diag(Var->getLocation(), DiagID) << Type << EmitCppCompat;
}
// Check for jumps past the implicit initializer. C++0x
// clarifies that this applies to a "variable with automatic
// storage duration", not a "local variable".
// C++11 [stmt.dcl]p3
// A program that jumps from a point where a variable with automatic
// storage duration is not in scope to a point where it is in scope is
// ill-formed unless the variable has scalar type, class type with a
// trivial default constructor and a trivial destructor, a cv-qualified
// version of one of these types, or an array of one of the preceding
// types and is declared without an initializer.
if (getLangOpts().CPlusPlus && Var->hasLocalStorage()) {
if (const auto *CXXRecord =
Context.getBaseElementType(Type)->getAsCXXRecordDecl()) {
// Mark the function (if we're in one) for further checking even if the
// looser rules of C++11 do not require such checks, so that we can
// diagnose incompatibilities with C++98.
if (!CXXRecord->isPOD())
setFunctionHasBranchProtectedScope();
}
}
// In OpenCL, we can't initialize objects in the __local address space,
// even implicitly, so don't synthesize an implicit initializer.
if (getLangOpts().OpenCL &&
Var->getType().getAddressSpace() == LangAS::opencl_local)
return;
// Handle HLSL uninitialized decls
if (getLangOpts().HLSL && HLSL().ActOnUninitializedVarDecl(Var))
return;
// HLSL input variables are expected to be externally initialized, even
// when marked `static`.
if (getLangOpts().HLSL &&
Var->getType().getAddressSpace() == LangAS::hlsl_input)
return;
// C++03 [dcl.init]p9:
// If no initializer is specified for an object, and the
// object is of (possibly cv-qualified) non-POD class type (or
// array thereof), the object shall be default-initialized; if
// the object is of const-qualified type, the underlying class
// type shall have a user-declared default
// constructor. Otherwise, if no initializer is specified for
// a non- static object, the object and its subobjects, if
// any, have an indeterminate initial value); if the object
// or any of its subobjects are of const-qualified type, the
// program is ill-formed.
// C++0x [dcl.init]p11:
// If no initializer is specified for an object, the object is
// default-initialized; [...].
InitializedEntity Entity = InitializedEntity::InitializeVariable(Var);
InitializationKind Kind
= InitializationKind::CreateDefault(Var->getLocation());
InitializationSequence InitSeq(*this, Entity, Kind, {});
ExprResult Init = InitSeq.Perform(*this, Entity, Kind, {});
if (Init.get()) {
Var->setInit(MaybeCreateExprWithCleanups(Init.get()));
// This is important for template substitution.
Var->setInitStyle(VarDecl::CallInit);
} else if (Init.isInvalid()) {
// If default-init fails, attach a recovery-expr initializer to track
// that initialization was attempted and failed.
auto RecoveryExpr =
CreateRecoveryExpr(Var->getLocation(), Var->getLocation(), {});
if (RecoveryExpr.get())
Var->setInit(RecoveryExpr.get());
}
CheckCompleteVariableDeclaration(Var);
}
}
void Sema::ActOnCXXForRangeDecl(Decl *D) {
// If there is no declaration, there was an error parsing it. Ignore it.
if (!D)
return;
VarDecl *VD = dyn_cast<VarDecl>(D);
if (!VD) {
Diag(D->getLocation(), diag::err_for_range_decl_must_be_var);
D->setInvalidDecl();
return;
}
VD->setCXXForRangeDecl(true);
// for-range-declaration cannot be given a storage class specifier.
int Error = -1;
switch (VD->getStorageClass()) {
case SC_None:
break;
case SC_Extern:
Error = 0;
break;
case SC_Static:
Error = 1;
break;
case SC_PrivateExtern:
Error = 2;
break;
case SC_Auto:
Error = 3;
break;
case SC_Register:
Error = 4;
break;
}
// for-range-declaration cannot be given a storage class specifier con't.
switch (VD->getTSCSpec()) {
case TSCS_thread_local:
Error = 6;
break;
case TSCS___thread:
case TSCS__Thread_local:
case TSCS_unspecified:
break;
}
if (Error != -1) {
Diag(VD->getOuterLocStart(), diag::err_for_range_storage_class)
<< VD << Error;
D->setInvalidDecl();
}
}
StmtResult Sema::ActOnCXXForRangeIdentifier(Scope *S, SourceLocation IdentLoc,
IdentifierInfo *Ident,
ParsedAttributes &Attrs) {
// C++1y [stmt.iter]p1:
// A range-based for statement of the form
// for ( for-range-identifier : for-range-initializer ) statement
// is equivalent to
// for ( auto&& for-range-identifier : for-range-initializer ) statement
DeclSpec DS(Attrs.getPool().getFactory());
const char *PrevSpec;
unsigned DiagID;
DS.SetTypeSpecType(DeclSpec::TST_auto, IdentLoc, PrevSpec, DiagID,
getPrintingPolicy());
Declarator D(DS, ParsedAttributesView::none(), DeclaratorContext::ForInit);
D.SetIdentifier(Ident, IdentLoc);
D.takeAttributes(Attrs);
D.AddTypeInfo(DeclaratorChunk::getReference(0, IdentLoc, /*lvalue*/ false),
IdentLoc);
Decl *Var = ActOnDeclarator(S, D);
cast<VarDecl>(Var)->setCXXForRangeDecl(true);
FinalizeDeclaration(Var);
return ActOnDeclStmt(FinalizeDeclaratorGroup(S, DS, Var), IdentLoc,
Attrs.Range.getEnd().isValid() ? Attrs.Range.getEnd()
: IdentLoc);
}
void Sema::CheckCompleteVariableDeclaration(VarDecl *var) {
if (var->isInvalidDecl()) return;
CUDA().MaybeAddConstantAttr(var);
if (getLangOpts().OpenCL) {
// OpenCL v2.0 s6.12.5 - Every block variable declaration must have an
// initialiser
if (var->getTypeSourceInfo()->getType()->isBlockPointerType() &&
!var->hasInit()) {
Diag(var->getLocation(), diag::err_opencl_invalid_block_declaration)
<< 1 /*Init*/;
var->setInvalidDecl();
return;
}
}
// In Objective-C, don't allow jumps past the implicit initialization of a
// local retaining variable.
if (getLangOpts().ObjC &&
var->hasLocalStorage()) {
switch (var->getType().getObjCLifetime()) {
case Qualifiers::OCL_None:
case Qualifiers::OCL_ExplicitNone:
case Qualifiers::OCL_Autoreleasing:
break;
case Qualifiers::OCL_Weak:
case Qualifiers::OCL_Strong:
setFunctionHasBranchProtectedScope();
break;
}
}
if (var->hasLocalStorage() &&
var->getType().isDestructedType() == QualType::DK_nontrivial_c_struct)
setFunctionHasBranchProtectedScope();
// Warn about externally-visible variables being defined without a
// prior declaration. We only want to do this for global
// declarations, but we also specifically need to avoid doing it for
// class members because the linkage of an anonymous class can
// change if it's later given a typedef name.
if (var->isThisDeclarationADefinition() &&
var->getDeclContext()->getRedeclContext()->isFileContext() &&
var->isExternallyVisible() && var->hasLinkage() &&
!var->isInline() && !var->getDescribedVarTemplate() &&
var->getStorageClass() != SC_Register &&
!isa<VarTemplatePartialSpecializationDecl>(var) &&
!isTemplateInstantiation(var->getTemplateSpecializationKind()) &&
!getDiagnostics().isIgnored(diag::warn_missing_variable_declarations,
var->getLocation())) {
// Find a previous declaration that's not a definition.
VarDecl *prev = var->getPreviousDecl();
while (prev && prev->isThisDeclarationADefinition())
prev = prev->getPreviousDecl();
if (!prev) {
Diag(var->getLocation(), diag::warn_missing_variable_declarations) << var;
Diag(var->getTypeSpecStartLoc(), diag::note_static_for_internal_linkage)
<< /* variable */ 0;
}
}
// Cache the result of checking for constant initialization.
std::optional<bool> CacheHasConstInit;
const Expr *CacheCulprit = nullptr;
auto checkConstInit = [&]() mutable {
const Expr *Init = var->getInit();
if (Init->isInstantiationDependent())
return true;
if (!CacheHasConstInit)
CacheHasConstInit = var->getInit()->isConstantInitializer(
Context, var->getType()->isReferenceType(), &CacheCulprit);
return *CacheHasConstInit;
};
if (var->getTLSKind() == VarDecl::TLS_Static) {
if (var->getType().isDestructedType()) {
// GNU C++98 edits for __thread, [basic.start.term]p3:
// The type of an object with thread storage duration shall not
// have a non-trivial destructor.
Diag(var->getLocation(), diag::err_thread_nontrivial_dtor);
if (getLangOpts().CPlusPlus11)
Diag(var->getLocation(), diag::note_use_thread_local);
} else if (getLangOpts().CPlusPlus && var->hasInit()) {
if (!checkConstInit()) {
// GNU C++98 edits for __thread, [basic.start.init]p4:
// An object of thread storage duration shall not require dynamic
// initialization.
// FIXME: Need strict checking here.
Diag(CacheCulprit->getExprLoc(), diag::err_thread_dynamic_init)
<< CacheCulprit->getSourceRange();
if (getLangOpts().CPlusPlus11)
Diag(var->getLocation(), diag::note_use_thread_local);
}
}
}
if (!var->getType()->isStructureType() && var->hasInit() &&
isa<InitListExpr>(var->getInit())) {
const auto *ILE = cast<InitListExpr>(var->getInit());
unsigned NumInits = ILE->getNumInits();
if (NumInits > 2)
for (unsigned I = 0; I < NumInits; ++I) {
const auto *Init = ILE->getInit(I);
if (!Init)
break;
const auto *SL = dyn_cast<StringLiteral>(Init->IgnoreImpCasts());
if (!SL)
break;
unsigned NumConcat = SL->getNumConcatenated();
// Diagnose missing comma in string array initialization.
// Do not warn when all the elements in the initializer are concatenated
// together. Do not warn for macros too.
if (NumConcat == 2 && !SL->getBeginLoc().isMacroID()) {
bool OnlyOneMissingComma = true;
for (unsigned J = I + 1; J < NumInits; ++J) {
const auto *Init = ILE->getInit(J);
if (!Init)
break;
const auto *SLJ = dyn_cast<StringLiteral>(Init->IgnoreImpCasts());
if (!SLJ || SLJ->getNumConcatenated() > 1) {
OnlyOneMissingComma = false;
break;
}
}
if (OnlyOneMissingComma) {
SmallVector<FixItHint, 1> Hints;
for (unsigned i = 0; i < NumConcat - 1; ++i)
Hints.push_back(FixItHint::CreateInsertion(
PP.getLocForEndOfToken(SL->getStrTokenLoc(i)), ","));
Diag(SL->getStrTokenLoc(1),
diag::warn_concatenated_literal_array_init)
<< Hints;
Diag(SL->getBeginLoc(),
diag::note_concatenated_string_literal_silence);
}
// In any case, stop now.
break;
}
}
}
QualType type = var->getType();
if (var->hasAttr<BlocksAttr>())
getCurFunction()->addByrefBlockVar(var);
Expr *Init = var->getInit();
bool GlobalStorage = var->hasGlobalStorage();
bool IsGlobal = GlobalStorage && !var->isStaticLocal();
QualType baseType = Context.getBaseElementType(type);
bool HasConstInit = true;
if (getLangOpts().C23 && var->isConstexpr() && !Init)
Diag(var->getLocation(), diag::err_constexpr_var_requires_const_init)
<< var;
// Check whether the initializer is sufficiently constant.
if ((getLangOpts().CPlusPlus || (getLangOpts().C23 && var->isConstexpr())) &&
!type->isDependentType() && Init && !Init->isValueDependent() &&
(GlobalStorage || var->isConstexpr() ||
var->mightBeUsableInConstantExpressions(Context))) {
// If this variable might have a constant initializer or might be usable in
// constant expressions, check whether or not it actually is now. We can't
// do this lazily, because the result might depend on things that change
// later, such as which constexpr functions happen to be defined.
SmallVector<PartialDiagnosticAt, 8> Notes;
if (!getLangOpts().CPlusPlus11 && !getLangOpts().C23) {
// Prior to C++11, in contexts where a constant initializer is required,
// the set of valid constant initializers is described by syntactic rules
// in [expr.const]p2-6.
// FIXME: Stricter checking for these rules would be useful for constinit /
// -Wglobal-constructors.
HasConstInit = checkConstInit();
// Compute and cache the constant value, and remember that we have a
// constant initializer.
if (HasConstInit) {
if (var->isStaticDataMember() && !var->isInline() &&
var->getLexicalDeclContext()->isRecord() &&
type->isIntegralOrEnumerationType()) {
// In C++98, in-class initialization for a static data member must
// be an integer constant expression.
if (!Init->isIntegerConstantExpr(Context)) {
Diag(Init->getExprLoc(),
diag::ext_in_class_initializer_non_constant)
<< Init->getSourceRange();
}
}
(void)var->checkForConstantInitialization(Notes);
Notes.clear();
} else if (CacheCulprit) {
Notes.emplace_back(CacheCulprit->getExprLoc(),
PDiag(diag::note_invalid_subexpr_in_const_expr));
Notes.back().second << CacheCulprit->getSourceRange();
}
} else {
// Evaluate the initializer to see if it's a constant initializer.
HasConstInit = var->checkForConstantInitialization(Notes);
}
if (HasConstInit) {
// FIXME: Consider replacing the initializer with a ConstantExpr.
} else if (var->isConstexpr()) {
SourceLocation DiagLoc = var->getLocation();
// If the note doesn't add any useful information other than a source
// location, fold it into the primary diagnostic.
if (Notes.size() == 1 && Notes[0].second.getDiagID() ==
diag::note_invalid_subexpr_in_const_expr) {
DiagLoc = Notes[0].first;
Notes.clear();
}
Diag(DiagLoc, diag::err_constexpr_var_requires_const_init)
<< var << Init->getSourceRange();
for (unsigned I = 0, N = Notes.size(); I != N; ++I)
Diag(Notes[I].first, Notes[I].second);
} else if (GlobalStorage && var->hasAttr<ConstInitAttr>()) {
auto *Attr = var->getAttr<ConstInitAttr>();
Diag(var->getLocation(), diag::err_require_constant_init_failed)
<< Init->getSourceRange();
Diag(Attr->getLocation(), diag::note_declared_required_constant_init_here)
<< Attr->getRange() << Attr->isConstinit();
for (auto &it : Notes)
Diag(it.first, it.second);
} else if (var->isStaticDataMember() && !var->isInline() &&
var->getLexicalDeclContext()->isRecord()) {
Diag(var->getLocation(), diag::err_in_class_initializer_non_constant)
<< Init->getSourceRange();
for (auto &it : Notes)
Diag(it.first, it.second);
var->setInvalidDecl();
} else if (IsGlobal &&
!getDiagnostics().isIgnored(diag::warn_global_constructor,
var->getLocation())) {
// Warn about globals which don't have a constant initializer. Don't
// warn about globals with a non-trivial destructor because we already
// warned about them.
CXXRecordDecl *RD = baseType->getAsCXXRecordDecl();
if (!(RD && !RD->hasTrivialDestructor())) {
// checkConstInit() here permits trivial default initialization even in
// C++11 onwards, where such an initializer is not a constant initializer
// but nonetheless doesn't require a global constructor.
if (!checkConstInit())
Diag(var->getLocation(), diag::warn_global_constructor)
<< Init->getSourceRange();
}
}
}
// Apply section attributes and pragmas to global variables.
if (GlobalStorage && var->isThisDeclarationADefinition() &&
!inTemplateInstantiation()) {
PragmaStack<StringLiteral *> *Stack = nullptr;
int SectionFlags = ASTContext::PSF_Read;
bool MSVCEnv =
Context.getTargetInfo().getTriple().isWindowsMSVCEnvironment();
std::optional<QualType::NonConstantStorageReason> Reason;
if (HasConstInit &&
!(Reason = var->getType().isNonConstantStorage(Context, true, false))) {
Stack = &ConstSegStack;
} else {
SectionFlags |= ASTContext::PSF_Write;
Stack = var->hasInit() && HasConstInit ? &DataSegStack : &BSSSegStack;
}
if (const SectionAttr *SA = var->getAttr<SectionAttr>()) {
if (SA->getSyntax() == AttributeCommonInfo::AS_Declspec)
SectionFlags |= ASTContext::PSF_Implicit;
UnifySection(SA->getName(), SectionFlags, var);
} else if (Stack->CurrentValue) {
if (Stack != &ConstSegStack && MSVCEnv &&
ConstSegStack.CurrentValue != ConstSegStack.DefaultValue &&
var->getType().isConstQualified()) {
assert((!Reason || Reason != QualType::NonConstantStorageReason::
NonConstNonReferenceType) &&
"This case should've already been handled elsewhere");
Diag(var->getLocation(), diag::warn_section_msvc_compat)
<< var << ConstSegStack.CurrentValue << (int)(!HasConstInit
? QualType::NonConstantStorageReason::NonTrivialCtor
: *Reason);
}
SectionFlags |= ASTContext::PSF_Implicit;
auto SectionName = Stack->CurrentValue->getString();
var->addAttr(SectionAttr::CreateImplicit(Context, SectionName,
Stack->CurrentPragmaLocation,
SectionAttr::Declspec_allocate));
if (UnifySection(SectionName, SectionFlags, var))
var->dropAttr<SectionAttr>();
}
// Apply the init_seg attribute if this has an initializer. If the
// initializer turns out to not be dynamic, we'll end up ignoring this
// attribute.
if (CurInitSeg && var->getInit())
var->addAttr(InitSegAttr::CreateImplicit(Context, CurInitSeg->getString(),
CurInitSegLoc));
}
// All the following checks are C++ only.
if (!getLangOpts().CPlusPlus) {
// If this variable must be emitted, add it as an initializer for the
// current module.
if (Context.DeclMustBeEmitted(var) && !ModuleScopes.empty())
Context.addModuleInitializer(ModuleScopes.back().Module, var);
return;
}
DiagnoseUniqueObjectDuplication(var);
// Require the destructor.
if (!type->isDependentType())
if (auto *RD = baseType->getAsCXXRecordDecl())
FinalizeVarWithDestructor(var, RD);
// If this variable must be emitted, add it as an initializer for the current
// module.
if (Context.DeclMustBeEmitted(var) && !ModuleScopes.empty())
Context.addModuleInitializer(ModuleScopes.back().Module, var);
// Build the bindings if this is a structured binding declaration.
if (auto *DD = dyn_cast<DecompositionDecl>(var))
CheckCompleteDecompositionDeclaration(DD);
}
void Sema::CheckStaticLocalForDllExport(VarDecl *VD) {
assert(VD->isStaticLocal());
auto *FD = dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod());
// Find outermost function when VD is in lambda function.
while (FD && !getDLLAttr(FD) &&
!FD->hasAttr<DLLExportStaticLocalAttr>() &&
!FD->hasAttr<DLLImportStaticLocalAttr>()) {
FD = dyn_cast_or_null<FunctionDecl>(FD->getParentFunctionOrMethod());
}
if (!FD)
return;
// Static locals inherit dll attributes from their function.
if (Attr *A = getDLLAttr(FD)) {
auto *NewAttr = cast<InheritableAttr>(A->clone(getASTContext()));
NewAttr->setInherited(true);
VD->addAttr(NewAttr);
} else if (Attr *A = FD->getAttr<DLLExportStaticLocalAttr>()) {
auto *NewAttr = DLLExportAttr::CreateImplicit(getASTContext(), *A);
NewAttr->setInherited(true);
VD->addAttr(NewAttr);
// Export this function to enforce exporting this static variable even
// if it is not used in this compilation unit.
if (!FD->hasAttr<DLLExportAttr>())
FD->addAttr(NewAttr);
} else if (Attr *A = FD->getAttr<DLLImportStaticLocalAttr>()) {
auto *NewAttr = DLLImportAttr::CreateImplicit(getASTContext(), *A);
NewAttr->setInherited(true);
VD->addAttr(NewAttr);
}
}
void Sema::CheckThreadLocalForLargeAlignment(VarDecl *VD) {
assert(VD->getTLSKind());
// Perform TLS alignment check here after attributes attached to the variable
// which may affect the alignment have been processed. Only perform the check
// if the target has a maximum TLS alignment (zero means no constraints).
if (unsigned MaxAlign = Context.getTargetInfo().getMaxTLSAlign()) {
// Protect the check so that it's not performed on dependent types and
// dependent alignments (we can't determine the alignment in that case).
if (!VD->hasDependentAlignment()) {
CharUnits MaxAlignChars = Context.toCharUnitsFromBits(MaxAlign);
if (Context.getDeclAlign(VD) > MaxAlignChars) {
Diag(VD->getLocation(), diag::err_tls_var_aligned_over_maximum)
<< (unsigned)Context.getDeclAlign(VD).getQuantity() << VD
<< (unsigned)MaxAlignChars.getQuantity();
}
}
}
}
void Sema::FinalizeDeclaration(Decl *ThisDecl) {
// Note that we are no longer parsing the initializer for this declaration.
ParsingInitForAutoVars.erase(ThisDecl);
VarDecl *VD = dyn_cast_or_null<VarDecl>(ThisDecl);
if (!VD)
return;
// Apply an implicit SectionAttr if '#pragma clang section bss|data|rodata' is active
if (VD->hasGlobalStorage() && VD->isThisDeclarationADefinition() &&
!inTemplateInstantiation() && !VD->hasAttr<SectionAttr>()) {
if (PragmaClangBSSSection.Valid)
VD->addAttr(PragmaClangBSSSectionAttr::CreateImplicit(
Context, PragmaClangBSSSection.SectionName,
PragmaClangBSSSection.PragmaLocation));
if (PragmaClangDataSection.Valid)
VD->addAttr(PragmaClangDataSectionAttr::CreateImplicit(
Context, PragmaClangDataSection.SectionName,
PragmaClangDataSection.PragmaLocation));
if (PragmaClangRodataSection.Valid)
VD->addAttr(PragmaClangRodataSectionAttr::CreateImplicit(
Context, PragmaClangRodataSection.SectionName,
PragmaClangRodataSection.PragmaLocation));
if (PragmaClangRelroSection.Valid)
VD->addAttr(PragmaClangRelroSectionAttr::CreateImplicit(
Context, PragmaClangRelroSection.SectionName,
PragmaClangRelroSection.PragmaLocation));
}
if (auto *DD = dyn_cast<DecompositionDecl>(ThisDecl)) {
for (auto *BD : DD->bindings()) {
FinalizeDeclaration(BD);
}
}
CheckInvalidBuiltinCountedByRef(VD->getInit(),
BuiltinCountedByRefKind::Initializer);
checkAttributesAfterMerging(*this, *VD);
if (VD->isStaticLocal())
CheckStaticLocalForDllExport(VD);
if (VD->getTLSKind())
CheckThreadLocalForLargeAlignment(VD);
// Perform check for initializers of device-side global variables.
// CUDA allows empty constructors as initializers (see E.2.3.1, CUDA
// 7.5). We must also apply the same checks to all __shared__
// variables whether they are local or not. CUDA also allows
// constant initializers for __constant__ and __device__ variables.
if (getLangOpts().CUDA)
CUDA().checkAllowedInitializer(VD);
// Grab the dllimport or dllexport attribute off of the VarDecl.
const InheritableAttr *DLLAttr = getDLLAttr(VD);
// Imported static data members cannot be defined out-of-line.
if (const auto *IA = dyn_cast_or_null<DLLImportAttr>(DLLAttr)) {
if (VD->isStaticDataMember() && VD->isOutOfLine() &&
VD->isThisDeclarationADefinition()) {
// We allow definitions of dllimport class template static data members
// with a warning.
CXXRecordDecl *Context =
cast<CXXRecordDecl>(VD->getFirstDecl()->getDeclContext());
bool IsClassTemplateMember =
isa<ClassTemplatePartialSpecializationDecl>(Context) ||
Context->getDescribedClassTemplate();
Diag(VD->getLocation(),
IsClassTemplateMember
? diag::warn_attribute_dllimport_static_field_definition
: diag::err_attribute_dllimport_static_field_definition);
Diag(IA->getLocation(), diag::note_attribute);
if (!IsClassTemplateMember)
VD->setInvalidDecl();
}
}
// dllimport/dllexport variables cannot be thread local, their TLS index
// isn't exported with the variable.
if (DLLAttr && VD->getTLSKind()) {
auto *F = dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod());
if (F && getDLLAttr(F)) {
assert(VD->isStaticLocal());
// But if this is a static local in a dlimport/dllexport function, the
// function will never be inlined, which means the var would never be
// imported, so having it marked import/export is safe.
} else {
Diag(VD->getLocation(), diag::err_attribute_dll_thread_local) << VD
<< DLLAttr;
VD->setInvalidDecl();
}
}
if (UsedAttr *Attr = VD->getAttr<UsedAttr>()) {
if (!Attr->isInherited() && !VD->isThisDeclarationADefinition()) {
Diag(Attr->getLocation(), diag::warn_attribute_ignored_on_non_definition)
<< Attr;
VD->dropAttr<UsedAttr>();
}
}
if (RetainAttr *Attr = VD->getAttr<RetainAttr>()) {
if (!Attr->isInherited() && !VD->isThisDeclarationADefinition()) {
Diag(Attr->getLocation(), diag::warn_attribute_ignored_on_non_definition)
<< Attr;
VD->dropAttr<RetainAttr>();
}
}
const DeclContext *DC = VD->getDeclContext();
// If there's a #pragma GCC visibility in scope, and this isn't a class
// member, set the visibility of this variable.
if (DC->getRedeclContext()->isFileContext() && VD->isExternallyVisible())
AddPushedVisibilityAttribute(VD);
// FIXME: Warn on unused var template partial specializations.
if (VD->isFileVarDecl() && !isa<VarTemplatePartialSpecializationDecl>(VD))
MarkUnusedFileScopedDecl(VD);
// Now we have parsed the initializer and can update the table of magic
// tag values.
if (!VD->hasAttr<TypeTagForDatatypeAttr>() ||
!VD->getType()->isIntegralOrEnumerationType())
return;
for (const auto *I : ThisDecl->specific_attrs<TypeTagForDatatypeAttr>()) {
const Expr *MagicValueExpr = VD->getInit();
if (!MagicValueExpr) {
continue;
}
std::optional<llvm::APSInt> MagicValueInt;
if (!(MagicValueInt = MagicValueExpr->getIntegerConstantExpr(Context))) {
Diag(I->getRange().getBegin(),
diag::err_type_tag_for_datatype_not_ice)
<< LangOpts.CPlusPlus << MagicValueExpr->getSourceRange();
continue;
}
if (MagicValueInt->getActiveBits() > 64) {
Diag(I->getRange().getBegin(),
diag::err_type_tag_for_datatype_too_large)
<< LangOpts.CPlusPlus << MagicValueExpr->getSourceRange();
continue;
}
uint64_t MagicValue = MagicValueInt->getZExtValue();
RegisterTypeTagForDatatype(I->getArgumentKind(),
MagicValue,
I->getMatchingCType(),
I->getLayoutCompatible(),
I->getMustBeNull());
}
}
static bool hasDeducedAuto(DeclaratorDecl *DD) {
auto *VD = dyn_cast<VarDecl>(DD);
return VD && !VD->getType()->hasAutoForTrailingReturnType();
}
Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS,
ArrayRef<Decl *> Group) {
SmallVector<Decl*, 8> Decls;
if (DS.isTypeSpecOwned())
Decls.push_back(DS.getRepAsDecl());
DeclaratorDecl *FirstDeclaratorInGroup = nullptr;
DecompositionDecl *FirstDecompDeclaratorInGroup = nullptr;
bool DiagnosedMultipleDecomps = false;
DeclaratorDecl *FirstNonDeducedAutoInGroup = nullptr;
bool DiagnosedNonDeducedAuto = false;
for (Decl *D : Group) {
if (!D)
continue;
// Check if the Decl has been declared in '#pragma omp declare target'
// directive and has static storage duration.
if (auto *VD = dyn_cast<VarDecl>(D);
LangOpts.OpenMP && VD && VD->hasAttr<OMPDeclareTargetDeclAttr>() &&
VD->hasGlobalStorage())
OpenMP().ActOnOpenMPDeclareTargetInitializer(D);
// For declarators, there are some additional syntactic-ish checks we need
// to perform.
if (auto *DD = dyn_cast<DeclaratorDecl>(D)) {
if (!FirstDeclaratorInGroup)
FirstDeclaratorInGroup = DD;
if (!FirstDecompDeclaratorInGroup)
FirstDecompDeclaratorInGroup = dyn_cast<DecompositionDecl>(D);
if (!FirstNonDeducedAutoInGroup && DS.hasAutoTypeSpec() &&
!hasDeducedAuto(DD))
FirstNonDeducedAutoInGroup = DD;
if (FirstDeclaratorInGroup != DD) {
// A decomposition declaration cannot be combined with any other
// declaration in the same group.
if (FirstDecompDeclaratorInGroup && !DiagnosedMultipleDecomps) {
Diag(FirstDecompDeclaratorInGroup->getLocation(),
diag::err_decomp_decl_not_alone)
<< FirstDeclaratorInGroup->getSourceRange()
<< DD->getSourceRange();
DiagnosedMultipleDecomps = true;
}
// A declarator that uses 'auto' in any way other than to declare a
// variable with a deduced type cannot be combined with any other
// declarator in the same group.
if (FirstNonDeducedAutoInGroup && !DiagnosedNonDeducedAuto) {
Diag(FirstNonDeducedAutoInGroup->getLocation(),
diag::err_auto_non_deduced_not_alone)
<< FirstNonDeducedAutoInGroup->getType()
->hasAutoForTrailingReturnType()
<< FirstDeclaratorInGroup->getSourceRange()
<< DD->getSourceRange();
DiagnosedNonDeducedAuto = true;
}
}
}
Decls.push_back(D);
}
if (DeclSpec::isDeclRep(DS.getTypeSpecType())) {
if (TagDecl *Tag = dyn_cast_or_null<TagDecl>(DS.getRepAsDecl())) {
handleTagNumbering(Tag, S);
if (FirstDeclaratorInGroup && !Tag->hasNameForLinkage() &&
getLangOpts().CPlusPlus)
Context.addDeclaratorForUnnamedTagDecl(Tag, FirstDeclaratorInGroup);
}
}
return BuildDeclaratorGroup(Decls);
}
Sema::DeclGroupPtrTy
Sema::BuildDeclaratorGroup(MutableArrayRef<Decl *> Group) {
// C++14 [dcl.spec.auto]p7: (DR1347)
// If the type that replaces the placeholder type is not the same in each
// deduction, the program is ill-formed.
if (Group.size() > 1) {
QualType Deduced;
VarDecl *DeducedDecl = nullptr;
for (unsigned i = 0, e = Group.size(); i != e; ++i) {
VarDecl *D = dyn_cast<VarDecl>(Group[i]);
if (!D || D->isInvalidDecl())
break;
DeducedType *DT = D->getType()->getContainedDeducedType();
if (!DT || DT->getDeducedType().isNull())
continue;
if (Deduced.isNull()) {
Deduced = DT->getDeducedType();
DeducedDecl = D;
} else if (!Context.hasSameType(DT->getDeducedType(), Deduced)) {
auto *AT = dyn_cast<AutoType>(DT);
auto Dia = Diag(D->getTypeSourceInfo()->getTypeLoc().getBeginLoc(),
diag::err_auto_different_deductions)
<< (AT ? (unsigned)AT->getKeyword() : 3) << Deduced
<< DeducedDecl->getDeclName() << DT->getDeducedType()
<< D->getDeclName();
if (DeducedDecl->hasInit())
Dia << DeducedDecl->getInit()->getSourceRange();
if (D->getInit())
Dia << D->getInit()->getSourceRange();
D->setInvalidDecl();
break;
}
}
}
ActOnDocumentableDecls(Group);
return DeclGroupPtrTy::make(
DeclGroupRef::Create(Context, Group.data(), Group.size()));
}
void Sema::ActOnDocumentableDecl(Decl *D) {
ActOnDocumentableDecls(D);
}
void Sema::ActOnDocumentableDecls(ArrayRef<Decl *> Group) {
// Don't parse the comment if Doxygen diagnostics are ignored.
if (Group.empty() || !Group[0])
return;
if (Diags.isIgnored(diag::warn_doc_param_not_found,
Group[0]->getLocation()) &&
Diags.isIgnored(diag::warn_unknown_comment_command_name,
Group[0]->getLocation()))
return;
if (Group.size() >= 2) {
// This is a decl group. Normally it will contain only declarations
// produced from declarator list. But in case we have any definitions or
// additional declaration references:
// 'typedef struct S {} S;'
// 'typedef struct S *S;'
// 'struct S *pS;'
// FinalizeDeclaratorGroup adds these as separate declarations.
Decl *MaybeTagDecl = Group[0];
if (MaybeTagDecl && isa<TagDecl>(MaybeTagDecl)) {
Group = Group.slice(1);
}
}
// FIMXE: We assume every Decl in the group is in the same file.
// This is false when preprocessor constructs the group from decls in
// different files (e. g. macros or #include).
Context.attachCommentsToJustParsedDecls(Group, &getPreprocessor());
}
void Sema::CheckFunctionOrTemplateParamDeclarator(Scope *S, Declarator &D) {
// Check that there are no default arguments inside the type of this
// parameter.
if (getLangOpts().CPlusPlus)
CheckExtraCXXDefaultArguments(D);
// Parameter declarators cannot be qualified (C++ [dcl.meaning]p1).
if (D.getCXXScopeSpec().isSet()) {
Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator)
<< D.getCXXScopeSpec().getRange();
}
// [dcl.meaning]p1: An unqualified-id occurring in a declarator-id shall be a
// simple identifier except [...irrelevant cases...].
switch (D.getName().getKind()) {
case UnqualifiedIdKind::IK_Identifier:
break;
case UnqualifiedIdKind::IK_OperatorFunctionId:
case UnqualifiedIdKind::IK_ConversionFunctionId:
case UnqualifiedIdKind::IK_LiteralOperatorId:
case UnqualifiedIdKind::IK_ConstructorName:
case UnqualifiedIdKind::IK_DestructorName:
case UnqualifiedIdKind::IK_ImplicitSelfParam:
case UnqualifiedIdKind::IK_DeductionGuideName:
Diag(D.getIdentifierLoc(), diag::err_bad_parameter_name)
<< GetNameForDeclarator(D).getName();
break;
case UnqualifiedIdKind::IK_TemplateId:
case UnqualifiedIdKind::IK_ConstructorTemplateId:
// GetNameForDeclarator would not produce a useful name in this case.
Diag(D.getIdentifierLoc(), diag::err_bad_parameter_name_template_id);
break;
}
}
void Sema::warnOnCTypeHiddenInCPlusPlus(const NamedDecl *D) {
// This only matters in C.
if (getLangOpts().CPlusPlus)
return;
// This only matters if the declaration has a type.
const auto *VD = dyn_cast<ValueDecl>(D);
if (!VD)
return;
// Get the type, this only matters for tag types.
QualType QT = VD->getType();
const auto *TD = QT->getAsTagDecl();
if (!TD)
return;
// Check if the tag declaration is lexically declared somewhere different
// from the lexical declaration of the given object, then it will be hidden
// in C++ and we should warn on it.
if (!TD->getLexicalParent()->LexicallyEncloses(D->getLexicalDeclContext())) {
unsigned Kind = TD->isEnum() ? 2 : TD->isUnion() ? 1 : 0;
Diag(D->getLocation(), diag::warn_decl_hidden_in_cpp) << Kind;
Diag(TD->getLocation(), diag::note_declared_at);
}
}
static void CheckExplicitObjectParameter(Sema &S, ParmVarDecl *P,
SourceLocation ExplicitThisLoc) {
if (!ExplicitThisLoc.isValid())
return;
assert(S.getLangOpts().CPlusPlus &&
"explicit parameter in non-cplusplus mode");
if (!S.getLangOpts().CPlusPlus23)
S.Diag(ExplicitThisLoc, diag::err_cxx20_deducing_this)
<< P->getSourceRange();
// C++2b [dcl.fct/7] An explicit object parameter shall not be a function
// parameter pack.
if (P->isParameterPack()) {
S.Diag(P->getBeginLoc(), diag::err_explicit_object_parameter_pack)
<< P->getSourceRange();
return;
}
P->setExplicitObjectParameterLoc(ExplicitThisLoc);
if (LambdaScopeInfo *LSI = S.getCurLambda())
LSI->ExplicitObjectParameter = P;
}
Decl *Sema::ActOnParamDeclarator(Scope *S, Declarator &D,
SourceLocation ExplicitThisLoc) {
const DeclSpec &DS = D.getDeclSpec();
// Verify C99 6.7.5.3p2: The only SCS allowed is 'register'.
// C2y 6.7.7.4p4: A parameter declaration shall not specify a void type,
// except for the special case of a single unnamed parameter of type void
// with no storage class specifier, no type qualifier, and no following
// ellipsis terminator.
// Clang applies the C2y rules for 'register void' in all C language modes,
// same as GCC, because it's questionable what that could possibly mean.
// C++03 [dcl.stc]p2 also permits 'auto'.
StorageClass SC = SC_None;
if (DS.getStorageClassSpec() == DeclSpec::SCS_register) {
SC = SC_Register;
// In C++11, the 'register' storage class specifier is deprecated.
// In C++17, it is not allowed, but we tolerate it as an extension.
if (getLangOpts().CPlusPlus11) {
Diag(DS.getStorageClassSpecLoc(), getLangOpts().CPlusPlus17
? diag::ext_register_storage_class
: diag::warn_deprecated_register)
<< FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
} else if (!getLangOpts().CPlusPlus &&
DS.getTypeSpecType() == DeclSpec::TST_void &&
D.getNumTypeObjects() == 0) {
Diag(DS.getStorageClassSpecLoc(),
diag::err_invalid_storage_class_in_func_decl)
<< FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
D.getMutableDeclSpec().ClearStorageClassSpecs();
}
} else if (getLangOpts().CPlusPlus &&
DS.getStorageClassSpec() == DeclSpec::SCS_auto) {
SC = SC_Auto;
} else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) {
Diag(DS.getStorageClassSpecLoc(),
diag::err_invalid_storage_class_in_func_decl);
D.getMutableDeclSpec().ClearStorageClassSpecs();
}
if (DeclSpec::TSCS TSCS = DS.getThreadStorageClassSpec())
Diag(DS.getThreadStorageClassSpecLoc(), diag::err_invalid_thread)
<< DeclSpec::getSpecifierName(TSCS);
if (DS.isInlineSpecified())
Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function)
<< getLangOpts().CPlusPlus17;
if (DS.hasConstexprSpecifier())
Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr)
<< 0 << static_cast<int>(D.getDeclSpec().getConstexprSpecifier());
DiagnoseFunctionSpecifiers(DS);
CheckFunctionOrTemplateParamDeclarator(S, D);
TypeSourceInfo *TInfo = GetTypeForDeclarator(D);
QualType parmDeclType = TInfo->getType();
// Check for redeclaration of parameters, e.g. int foo(int x, int x);
const IdentifierInfo *II = D.getIdentifier();
if (II) {
LookupResult R(*this, II, D.getIdentifierLoc(), LookupOrdinaryName,
RedeclarationKind::ForVisibleRedeclaration);
LookupName(R, S);
if (!R.empty()) {
NamedDecl *PrevDecl = *R.begin();
if (R.isSingleResult() && PrevDecl->isTemplateParameter()) {
// Maybe we will complain about the shadowed template parameter.
DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
// Just pretend that we didn't see the previous declaration.
PrevDecl = nullptr;
}
if (PrevDecl && S->isDeclScope(PrevDecl)) {
Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II;
Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
// Recover by removing the name
II = nullptr;
D.SetIdentifier(nullptr, D.getIdentifierLoc());
D.setInvalidType(true);
}
}
}
// Temporarily put parameter variables in the translation unit, not
// the enclosing context. This prevents them from accidentally
// looking like class members in C++.
ParmVarDecl *New =
CheckParameter(Context.getTranslationUnitDecl(), D.getBeginLoc(),
D.getIdentifierLoc(), II, parmDeclType, TInfo, SC);
if (D.isInvalidType())
New->setInvalidDecl();
CheckExplicitObjectParameter(*this, New, ExplicitThisLoc);
assert(S->isFunctionPrototypeScope());
assert(S->getFunctionPrototypeDepth() >= 1);
New->setScopeInfo(S->getFunctionPrototypeDepth() - 1,
S->getNextFunctionPrototypeIndex());
warnOnCTypeHiddenInCPlusPlus(New);
// Add the parameter declaration into this scope.
S->AddDecl(New);
if (II)
IdResolver.AddDecl(New);
ProcessDeclAttributes(S, New, D);
if (D.getDeclSpec().isModulePrivateSpecified())
Diag(New->getLocation(), diag::err_module_private_local)
<< 1 << New << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc())
<< FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc());
if (New->hasAttr<BlocksAttr>()) {
Diag(New->getLocation(), diag::err_block_on_nonlocal);
}
if (getLangOpts().OpenCL)
deduceOpenCLAddressSpace(New);
return New;
}
ParmVarDecl *Sema::BuildParmVarDeclForTypedef(DeclContext *DC,
SourceLocation Loc,
QualType T) {
/* FIXME: setting StartLoc == Loc.
Would it be worth to modify callers so as to provide proper source
location for the unnamed parameters, embedding the parameter's type? */
ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, Loc, Loc, nullptr,
T, Context.getTrivialTypeSourceInfo(T, Loc),
SC_None, nullptr);
Param->setImplicit();
return Param;
}
void Sema::DiagnoseUnusedParameters(ArrayRef<ParmVarDecl *> Parameters) {
// Don't diagnose unused-parameter errors in template instantiations; we
// will already have done so in the template itself.
if (inTemplateInstantiation())
return;
for (const ParmVarDecl *Parameter : Parameters) {
if (!Parameter->isReferenced() && Parameter->getDeclName() &&
!Parameter->hasAttr<UnusedAttr>() &&
!Parameter->getIdentifier()->isPlaceholder()) {
Diag(Parameter->getLocation(), diag::warn_unused_parameter)
<< Parameter->getDeclName();
}
}
}
void Sema::DiagnoseSizeOfParametersAndReturnValue(
ArrayRef<ParmVarDecl *> Parameters, QualType ReturnTy, NamedDecl *D) {
if (LangOpts.NumLargeByValueCopy == 0) // No check.
return;
// Warn if the return value is pass-by-value and larger than the specified
// threshold.
if (!ReturnTy->isDependentType() && ReturnTy.isPODType(Context)) {
unsigned Size = Context.getTypeSizeInChars(ReturnTy).getQuantity();
if (Size > LangOpts.NumLargeByValueCopy)
Diag(D->getLocation(), diag::warn_return_value_size) << D << Size;
}
// Warn if any parameter is pass-by-value and larger than the specified
// threshold.
for (const ParmVarDecl *Parameter : Parameters) {
QualType T = Parameter->getType();
if (T->isDependentType() || !T.isPODType(Context))
continue;
unsigned Size = Context.getTypeSizeInChars(T).getQuantity();
if (Size > LangOpts.NumLargeByValueCopy)
Diag(Parameter->getLocation(), diag::warn_parameter_size)
<< Parameter << Size;
}
}
ParmVarDecl *Sema::CheckParameter(DeclContext *DC, SourceLocation StartLoc,
SourceLocation NameLoc,
const IdentifierInfo *Name, QualType T,
TypeSourceInfo *TSInfo, StorageClass SC) {
// In ARC, infer a lifetime qualifier for appropriate parameter types.
if (getLangOpts().ObjCAutoRefCount &&
T.getObjCLifetime() == Qualifiers::OCL_None &&
T->isObjCLifetimeType()) {
Qualifiers::ObjCLifetime lifetime;
// Special cases for arrays:
// - if it's const, use __unsafe_unretained
// - otherwise, it's an error
if (T->isArrayType()) {
if (!T.isConstQualified()) {
if (DelayedDiagnostics.shouldDelayDiagnostics())
DelayedDiagnostics.add(
sema::DelayedDiagnostic::makeForbiddenType(
NameLoc, diag::err_arc_array_param_no_ownership, T, false));
else
Diag(NameLoc, diag::err_arc_array_param_no_ownership)
<< TSInfo->getTypeLoc().getSourceRange();
}
lifetime = Qualifiers::OCL_ExplicitNone;
} else {
lifetime = T->getObjCARCImplicitLifetime();
}
T = Context.getLifetimeQualifiedType(T, lifetime);
}
ParmVarDecl *New = ParmVarDecl::Create(Context, DC, StartLoc, NameLoc, Name,
Context.getAdjustedParameterType(T),
TSInfo, SC, nullptr);
// Make a note if we created a new pack in the scope of a lambda, so that
// we know that references to that pack must also be expanded within the
// lambda scope.
if (New->isParameterPack())
if (auto *CSI = getEnclosingLambdaOrBlock())
CSI->LocalPacks.push_back(New);
if (New->getType().hasNonTrivialToPrimitiveDestructCUnion() ||
New->getType().hasNonTrivialToPrimitiveCopyCUnion())
checkNonTrivialCUnion(New->getType(), New->getLocation(),
NonTrivialCUnionContext::FunctionParam,
NTCUK_Destruct | NTCUK_Copy);
// Parameter declarators cannot be interface types. All ObjC objects are
// passed by reference.
if (T->isObjCObjectType()) {
SourceLocation TypeEndLoc =
getLocForEndOfToken(TSInfo->getTypeLoc().getEndLoc());
Diag(NameLoc,
diag::err_object_cannot_be_passed_returned_by_value) << 1 << T
<< FixItHint::CreateInsertion(TypeEndLoc, "*");
T = Context.getObjCObjectPointerType(T);
New->setType(T);
}
// __ptrauth is forbidden on parameters.
if (T.getPointerAuth()) {
Diag(NameLoc, diag::err_ptrauth_qualifier_invalid) << T << 1;
New->setInvalidDecl();
}
// ISO/IEC TR 18037 S6.7.3: "The type of an object with automatic storage
// duration shall not be qualified by an address-space qualifier."
// Since all parameters have automatic store duration, they can not have
// an address space.
if (T.getAddressSpace() != LangAS::Default &&
// OpenCL allows function arguments declared to be an array of a type
// to be qualified with an address space.
!(getLangOpts().OpenCL &&
(T->isArrayType() || T.getAddressSpace() == LangAS::opencl_private)) &&
// WebAssembly allows reference types as parameters. Funcref in particular
// lives in a different address space.
!(T->isFunctionPointerType() &&
T.getAddressSpace() == LangAS::wasm_funcref)) {
Diag(NameLoc, diag::err_arg_with_address_space);
New->setInvalidDecl();
}
// PPC MMA non-pointer types are not allowed as function argument types.
if (Context.getTargetInfo().getTriple().isPPC64() &&
PPC().CheckPPCMMAType(New->getOriginalType(), New->getLocation())) {
New->setInvalidDecl();
}
return New;
}
void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D,
SourceLocation LocAfterDecls) {
DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
// C99 6.9.1p6 "If a declarator includes an identifier list, each declaration
// in the declaration list shall have at least one declarator, those
// declarators shall only declare identifiers from the identifier list, and
// every identifier in the identifier list shall be declared.
//
// C89 3.7.1p5 "If a declarator includes an identifier list, only the
// identifiers it names shall be declared in the declaration list."
//
// This is why we only diagnose in C99 and later. Note, the other conditions
// listed are checked elsewhere.
if (!FTI.hasPrototype) {
for (int i = FTI.NumParams; i != 0; /* decrement in loop */) {
--i;
if (FTI.Params[i].Param == nullptr) {
if (getLangOpts().C99) {
SmallString<256> Code;
llvm::raw_svector_ostream(Code)
<< " int " << FTI.Params[i].Ident->getName() << ";\n";
Diag(FTI.Params[i].IdentLoc, diag::ext_param_not_declared)
<< FTI.Params[i].Ident
<< FixItHint::CreateInsertion(LocAfterDecls, Code);
}
// Implicitly declare the argument as type 'int' for lack of a better
// type.
AttributeFactory attrs;
DeclSpec DS(attrs);
const char* PrevSpec; // unused
unsigned DiagID; // unused
DS.SetTypeSpecType(DeclSpec::TST_int, FTI.Params[i].IdentLoc, PrevSpec,
DiagID, Context.getPrintingPolicy());
// Use the identifier location for the type source range.
DS.SetRangeStart(FTI.Params[i].IdentLoc);
DS.SetRangeEnd(FTI.Params[i].IdentLoc);
Declarator ParamD(DS, ParsedAttributesView::none(),
DeclaratorContext::KNRTypeList);
ParamD.SetIdentifier(FTI.Params[i].Ident, FTI.Params[i].IdentLoc);
FTI.Params[i].Param = ActOnParamDeclarator(S, ParamD);
}
}
}
}
Decl *
Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D,
MultiTemplateParamsArg TemplateParameterLists,
SkipBodyInfo *SkipBody, FnBodyKind BodyKind) {
assert(getCurFunctionDecl() == nullptr && "Function parsing confused");
assert(D.isFunctionDeclarator() && "Not a function declarator!");
Scope *ParentScope = FnBodyScope->getParent();
// Check if we are in an `omp begin/end declare variant` scope. If we are, and
// we define a non-templated function definition, we will create a declaration
// instead (=BaseFD), and emit the definition with a mangled name afterwards.
// The base function declaration will have the equivalent of an `omp declare
// variant` annotation which specifies the mangled definition as a
// specialization function under the OpenMP context defined as part of the
// `omp begin declare variant`.
SmallVector<FunctionDecl *, 4> Bases;
if (LangOpts.OpenMP && OpenMP().isInOpenMPDeclareVariantScope())
OpenMP().ActOnStartOfFunctionDefinitionInOpenMPDeclareVariantScope(
ParentScope, D, TemplateParameterLists, Bases);
D.setFunctionDefinitionKind(FunctionDefinitionKind::Definition);
Decl *DP = HandleDeclarator(ParentScope, D, TemplateParameterLists);
Decl *Dcl = ActOnStartOfFunctionDef(FnBodyScope, DP, SkipBody, BodyKind);
if (!Bases.empty())
OpenMP().ActOnFinishedFunctionDefinitionInOpenMPDeclareVariantScope(Dcl,
Bases);
return Dcl;
}
void Sema::ActOnFinishInlineFunctionDef(FunctionDecl *D) {
Consumer.HandleInlineFunctionDefinition(D);
}
static bool FindPossiblePrototype(const FunctionDecl *FD,
const FunctionDecl *&PossiblePrototype) {
for (const FunctionDecl *Prev = FD->getPreviousDecl(); Prev;
Prev = Prev->getPreviousDecl()) {
// Ignore any declarations that occur in function or method
// scope, because they aren't visible from the header.
if (Prev->getLexicalDeclContext()->isFunctionOrMethod())
continue;
PossiblePrototype = Prev;
return Prev->getType()->isFunctionProtoType();
}
return false;
}
static bool
ShouldWarnAboutMissingPrototype(const FunctionDecl *FD,
const FunctionDecl *&PossiblePrototype) {
// Don't warn about invalid declarations.
if (FD->isInvalidDecl())
return false;
// Or declarations that aren't global.
if (!FD->isGlobal())
return false;
// Don't warn about C++ member functions.
if (isa<CXXMethodDecl>(FD))
return false;
// Don't warn about 'main'.
if (isa<TranslationUnitDecl>(FD->getDeclContext()->getRedeclContext()))
if (IdentifierInfo *II = FD->getIdentifier())
if (II->isStr("main") || II->isStr("efi_main"))
return false;
if (FD->isMSVCRTEntryPoint())
return false;
// Don't warn about inline functions.
if (FD->isInlined())
return false;
// Don't warn about function templates.
if (FD->getDescribedFunctionTemplate())
return false;
// Don't warn about function template specializations.
if (FD->isFunctionTemplateSpecialization())
return false;
// Don't warn for OpenCL kernels.
if (FD->hasAttr<DeviceKernelAttr>())
return false;
// Don't warn on explicitly deleted functions.
if (FD->isDeleted())
return false;
// Don't warn on implicitly local functions (such as having local-typed
// parameters).
if (!FD->isExternallyVisible())
return false;
// If we were able to find a potential prototype, don't warn.
if (FindPossiblePrototype(FD, PossiblePrototype))
return false;
return true;
}
void
Sema::CheckForFunctionRedefinition(FunctionDecl *FD,
const FunctionDecl *EffectiveDefinition,
SkipBodyInfo *SkipBody) {
const FunctionDecl *Definition = EffectiveDefinition;
if (!Definition &&
!FD->isDefined(Definition, /*CheckForPendingFriendDefinition*/ true))
return;
if (Definition->getFriendObjectKind() != Decl::FOK_None) {
if (FunctionDecl *OrigDef = Definition->getInstantiatedFromMemberFunction()) {
if (FunctionDecl *OrigFD = FD->getInstantiatedFromMemberFunction()) {
// A merged copy of the same function, instantiated as a member of
// the same class, is OK.
if (declaresSameEntity(OrigFD, OrigDef) &&
declaresSameEntity(cast<Decl>(Definition->getLexicalDeclContext()),
cast<Decl>(FD->getLexicalDeclContext())))
return;
}
}
}
if (canRedefineFunction(Definition, getLangOpts()))
return;
// Don't emit an error when this is redefinition of a typo-corrected
// definition.
if (TypoCorrectedFunctionDefinitions.count(Definition))
return;
bool DefinitionVisible = false;
if (SkipBody && isRedefinitionAllowedFor(Definition, DefinitionVisible) &&
(Definition->getFormalLinkage() == Linkage::Internal ||
Definition->isInlined() || Definition->getDescribedFunctionTemplate() ||
Definition->getNumTemplateParameterLists())) {
SkipBody->ShouldSkip = true;
SkipBody->Previous = const_cast<FunctionDecl*>(Definition);
if (!DefinitionVisible) {
if (auto *TD = Definition->getDescribedFunctionTemplate())
makeMergedDefinitionVisible(TD);
makeMergedDefinitionVisible(const_cast<FunctionDecl *>(Definition));
}
return;
}
if (getLangOpts().GNUMode && Definition->isInlineSpecified() &&
Definition->getStorageClass() == SC_Extern)
Diag(FD->getLocation(), diag::err_redefinition_extern_inline)
<< FD << getLangOpts().CPlusPlus;
else
Diag(FD->getLocation(), diag::err_redefinition) << FD;
Diag(Definition->getLocation(), diag::note_previous_definition);
FD->setInvalidDecl();
}
LambdaScopeInfo *Sema::RebuildLambdaScopeInfo(CXXMethodDecl *CallOperator) {
CXXRecordDecl *LambdaClass = CallOperator->getParent();
LambdaScopeInfo *LSI = PushLambdaScope();
LSI->CallOperator = CallOperator;
LSI->Lambda = LambdaClass;
LSI->ReturnType = CallOperator->getReturnType();
// When this function is called in situation where the context of the call
// operator is not entered, we set AfterParameterList to false, so that
// `tryCaptureVariable` finds explicit captures in the appropriate context.
// There is also at least a situation as in FinishTemplateArgumentDeduction(),
// where we would set the CurContext to the lambda operator before
// substituting into it. In this case the flag needs to be true such that
// tryCaptureVariable can correctly handle potential captures thereof.
LSI->AfterParameterList = CurContext == CallOperator;
// GLTemplateParameterList is necessary for getCurGenericLambda() which is
// used at the point of dealing with potential captures.
//
// We don't use LambdaClass->isGenericLambda() because this value doesn't
// flip for instantiated generic lambdas, where no FunctionTemplateDecls are
// associated. (Technically, we could recover that list from their
// instantiation patterns, but for now, the GLTemplateParameterList seems
// unnecessary in these cases.)
if (FunctionTemplateDecl *FTD = CallOperator->getDescribedFunctionTemplate())
LSI->GLTemplateParameterList = FTD->getTemplateParameters();
const LambdaCaptureDefault LCD = LambdaClass->getLambdaCaptureDefault();
if (LCD == LCD_None)
LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_None;
else if (LCD == LCD_ByCopy)
LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_LambdaByval;
else if (LCD == LCD_ByRef)
LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_LambdaByref;
DeclarationNameInfo DNI = CallOperator->getNameInfo();
LSI->IntroducerRange = DNI.getCXXOperatorNameRange();
LSI->Mutable = !CallOperator->isConst();
if (CallOperator->isExplicitObjectMemberFunction())
LSI->ExplicitObjectParameter = CallOperator->getParamDecl(0);
// Add the captures to the LSI so they can be noted as already
// captured within tryCaptureVar.
auto I = LambdaClass->field_begin();
for (const auto &C : LambdaClass->captures()) {
if (C.capturesVariable()) {
ValueDecl *VD = C.getCapturedVar();
if (VD->isInitCapture())
CurrentInstantiationScope->InstantiatedLocal(VD, VD);
const bool ByRef = C.getCaptureKind() == LCK_ByRef;
LSI->addCapture(VD, /*IsBlock*/false, ByRef,
/*RefersToEnclosingVariableOrCapture*/true, C.getLocation(),
/*EllipsisLoc*/C.isPackExpansion()
? C.getEllipsisLoc() : SourceLocation(),
I->getType(), /*Invalid*/false);
} else if (C.capturesThis()) {
LSI->addThisCapture(/*Nested*/ false, C.getLocation(), I->getType(),
C.getCaptureKind() == LCK_StarThis);
} else {
LSI->addVLATypeCapture(C.getLocation(), I->getCapturedVLAType(),
I->getType());
}
++I;
}
return LSI;
}
Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
SkipBodyInfo *SkipBody,
FnBodyKind BodyKind) {
if (!D) {
// Parsing the function declaration failed in some way. Push on a fake scope
// anyway so we can try to parse the function body.
PushFunctionScope();
PushExpressionEvaluationContext(ExprEvalContexts.back().Context);
return D;
}
FunctionDecl *FD = nullptr;
if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D))
FD = FunTmpl->getTemplatedDecl();
else
FD = cast<FunctionDecl>(D);
// Do not push if it is a lambda because one is already pushed when building
// the lambda in ActOnStartOfLambdaDefinition().
if (!isLambdaCallOperator(FD))
PushExpressionEvaluationContextForFunction(ExprEvalContexts.back().Context,
FD);
// Check for defining attributes before the check for redefinition.
if (const auto *Attr = FD->getAttr<AliasAttr>()) {
Diag(Attr->getLocation(), diag::err_alias_is_definition) << FD << 0;
FD->dropAttr<AliasAttr>();
FD->setInvalidDecl();
}
if (const auto *Attr = FD->getAttr<IFuncAttr>()) {
Diag(Attr->getLocation(), diag::err_alias_is_definition) << FD << 1;
FD->dropAttr<IFuncAttr>();
FD->setInvalidDecl();
}
if (const auto *Attr = FD->getAttr<TargetVersionAttr>()) {
if (Context.getTargetInfo().getTriple().isAArch64() &&
!Context.getTargetInfo().hasFeature("fmv") &&
!Attr->isDefaultVersion()) {
// If function multi versioning disabled skip parsing function body
// defined with non-default target_version attribute
if (SkipBody)
SkipBody->ShouldSkip = true;
return nullptr;
}
}
if (auto *Ctor = dyn_cast<CXXConstructorDecl>(FD)) {
if (Ctor->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
Ctor->isDefaultConstructor() &&
Context.getTargetInfo().getCXXABI().isMicrosoft()) {
// If this is an MS ABI dllexport default constructor, instantiate any
// default arguments.
InstantiateDefaultCtorDefaultArgs(Ctor);
}
}
// See if this is a redefinition. If 'will have body' (or similar) is already
// set, then these checks were already performed when it was set.
if (!FD->willHaveBody() && !FD->isLateTemplateParsed() &&
!FD->isThisDeclarationInstantiatedFromAFriendDefinition()) {
CheckForFunctionRedefinition(FD, nullptr, SkipBody);
// If we're skipping the body, we're done. Don't enter the scope.
if (SkipBody && SkipBody->ShouldSkip)
return D;
}
// Mark this function as "will have a body eventually". This lets users to
// call e.g. isInlineDefinitionExternallyVisible while we're still parsing
// this function.
FD->setWillHaveBody();
// If we are instantiating a generic lambda call operator, push
// a LambdaScopeInfo onto the function stack. But use the information
// that's already been calculated (ActOnLambdaExpr) to prime the current
// LambdaScopeInfo.
// When the template operator is being specialized, the LambdaScopeInfo,
// has to be properly restored so that tryCaptureVariable doesn't try
// and capture any new variables. In addition when calculating potential
// captures during transformation of nested lambdas, it is necessary to
// have the LSI properly restored.
if (isGenericLambdaCallOperatorSpecialization(FD)) {
// C++2c 7.5.5.2p17 A member of a closure type shall not be explicitly
// instantiated, explicitly specialized.
if (FD->getTemplateSpecializationInfo()
->isExplicitInstantiationOrSpecialization()) {
Diag(FD->getLocation(), diag::err_lambda_explicit_spec);
FD->setInvalidDecl();
PushFunctionScope();
} else {
assert(inTemplateInstantiation() &&
"There should be an active template instantiation on the stack "
"when instantiating a generic lambda!");
RebuildLambdaScopeInfo(cast<CXXMethodDecl>(D));
}
} else {
// Enter a new function scope
PushFunctionScope();
}
// Builtin functions cannot be defined.
if (unsigned BuiltinID = FD->getBuiltinID()) {
if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID) &&
!Context.BuiltinInfo.isPredefinedRuntimeFunction(BuiltinID)) {
Diag(FD->getLocation(), diag::err_builtin_definition) << FD;
FD->setInvalidDecl();
}
}
// The return type of a function definition must be complete (C99 6.9.1p3).
// C++23 [dcl.fct.def.general]/p2
// The type of [...] the return for a function definition
// shall not be a (possibly cv-qualified) class type that is incomplete
// or abstract within the function body unless the function is deleted.
QualType ResultType = FD->getReturnType();
if (!ResultType->isDependentType() && !ResultType->isVoidType() &&
!FD->isInvalidDecl() && BodyKind != FnBodyKind::Delete &&
(RequireCompleteType(FD->getLocation(), ResultType,
diag::err_func_def_incomplete_result) ||
RequireNonAbstractType(FD->getLocation(), FD->getReturnType(),
diag::err_abstract_type_in_decl,
AbstractReturnType)))
FD->setInvalidDecl();
if (FnBodyScope)
PushDeclContext(FnBodyScope, FD);
// Check the validity of our function parameters
if (BodyKind != FnBodyKind::Delete)
CheckParmsForFunctionDef(FD->parameters(),
/*CheckParameterNames=*/true);
// Add non-parameter declarations already in the function to the current
// scope.
if (FnBodyScope) {
for (Decl *NPD : FD->decls()) {
auto *NonParmDecl = dyn_cast<NamedDecl>(NPD);
if (!NonParmDecl)
continue;
assert(!isa<ParmVarDecl>(NonParmDecl) &&
"parameters should not be in newly created FD yet");
// If the decl has a name, make it accessible in the current scope.
if (NonParmDecl->getDeclName())
PushOnScopeChains(NonParmDecl, FnBodyScope, /*AddToContext=*/false);
// Similarly, dive into enums and fish their constants out, making them
// accessible in this scope.
if (auto *ED = dyn_cast<EnumDecl>(NonParmDecl)) {
for (auto *EI : ED->enumerators())
PushOnScopeChains(EI, FnBodyScope, /*AddToContext=*/false);
}
}
}
// Introduce our parameters into the function scope
for (auto *Param : FD->parameters()) {
Param->setOwningFunction(FD);
// If this has an identifier, add it to the scope stack.
if (Param->getIdentifier() && FnBodyScope) {
CheckShadow(FnBodyScope, Param);
PushOnScopeChains(Param, FnBodyScope);
}
}
// C++ [module.import/6] external definitions are not permitted in header
// units. Deleted and Defaulted functions are implicitly inline (but the
// inline state is not set at this point, so check the BodyKind explicitly).
// FIXME: Consider an alternate location for the test where the inlined()
// state is complete.
if (getLangOpts().CPlusPlusModules && currentModuleIsHeaderUnit() &&
!FD->isInvalidDecl() && !FD->isInlined() &&
BodyKind != FnBodyKind::Delete && BodyKind != FnBodyKind::Default &&
FD->getFormalLinkage() == Linkage::External && !FD->isTemplated() &&
!FD->isTemplateInstantiation()) {
assert(FD->isThisDeclarationADefinition());
Diag(FD->getLocation(), diag::err_extern_def_in_header_unit);
FD->setInvalidDecl();
}
// Ensure that the function's exception specification is instantiated.
if (const FunctionProtoType *FPT = FD->getType()->getAs<FunctionProtoType>())
ResolveExceptionSpec(D->getLocation(), FPT);
// dllimport cannot be applied to non-inline function definitions.
if (FD->hasAttr<DLLImportAttr>() && !FD->isInlined() &&
!FD->isTemplateInstantiation()) {
assert(!FD->hasAttr<DLLExportAttr>());
Diag(FD->getLocation(), diag::err_attribute_dllimport_function_definition);
FD->setInvalidDecl();
return D;
}
// Some function attributes (like OptimizeNoneAttr) need actions before
// parsing body started.
applyFunctionAttributesBeforeParsingBody(D);
// We want to attach documentation to original Decl (which might be
// a function template).
ActOnDocumentableDecl(D);
if (getCurLexicalContext()->isObjCContainer() &&
getCurLexicalContext()->getDeclKind() != Decl::ObjCCategoryImpl &&
getCurLexicalContext()->getDeclKind() != Decl::ObjCImplementation)
Diag(FD->getLocation(), diag::warn_function_def_in_objc_container);
maybeAddDeclWithEffects(FD);
return D;
}
void Sema::applyFunctionAttributesBeforeParsingBody(Decl *FD) {
if (!FD || FD->isInvalidDecl())
return;
if (auto *TD = dyn_cast<FunctionTemplateDecl>(FD))
FD = TD->getTemplatedDecl();
if (FD && FD->hasAttr<OptimizeNoneAttr>()) {
FPOptionsOverride FPO;
FPO.setDisallowOptimizations();
CurFPFeatures.applyChanges(FPO);
FpPragmaStack.CurrentValue =
CurFPFeatures.getChangesFrom(FPOptions(LangOpts));
}
}
void Sema::computeNRVO(Stmt *Body, FunctionScopeInfo *Scope) {
ReturnStmt **Returns = Scope->Returns.data();
for (unsigned I = 0, E = Scope->Returns.size(); I != E; ++I) {
if (const VarDecl *NRVOCandidate = Returns[I]->getNRVOCandidate()) {
if (!NRVOCandidate->isNRVOVariable()) {
Diag(Returns[I]->getRetValue()->getExprLoc(),
diag::warn_not_eliding_copy_on_return);
Returns[I]->setNRVOCandidate(nullptr);
}
}
}
}
bool Sema::canDelayFunctionBody(const Declarator &D) {
// We can't delay parsing the body of a constexpr function template (yet).
if (D.getDeclSpec().hasConstexprSpecifier())
return false;
// We can't delay parsing the body of a function template with a deduced
// return type (yet).
if (D.getDeclSpec().hasAutoTypeSpec()) {
// If the placeholder introduces a non-deduced trailing return type,
// we can still delay parsing it.
if (D.getNumTypeObjects()) {
const auto &Outer = D.getTypeObject(D.getNumTypeObjects() - 1);
if (Outer.Kind == DeclaratorChunk::Function &&
Outer.Fun.hasTrailingReturnType()) {
QualType Ty = GetTypeFromParser(Outer.Fun.getTrailingReturnType());
return Ty.isNull() || !Ty->isUndeducedType();
}
}
return false;
}
return true;
}
bool Sema::canSkipFunctionBody(Decl *D) {
// We cannot skip the body of a function (or function template) which is
// constexpr, since we may need to evaluate its body in order to parse the
// rest of the file.
// We cannot skip the body of a function with an undeduced return type,
// because any callers of that function need to know the type.
if (const FunctionDecl *FD = D->getAsFunction()) {
if (FD->isConstexpr())
return false;
// We can't simply call Type::isUndeducedType here, because inside template
// auto can be deduced to a dependent type, which is not considered
// "undeduced".
if (FD->getReturnType()->getContainedDeducedType())
return false;
}
return Consumer.shouldSkipFunctionBody(D);
}
Decl *Sema::ActOnSkippedFunctionBody(Decl *Decl) {
if (!Decl)
return nullptr;
if (FunctionDecl *FD = Decl->getAsFunction())
FD->setHasSkippedBody();
else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(Decl))
MD->setHasSkippedBody();
return Decl;
}
/// RAII object that pops an ExpressionEvaluationContext when exiting a function
/// body.
class ExitFunctionBodyRAII {
public:
ExitFunctionBodyRAII(Sema &S, bool IsLambda) : S(S), IsLambda(IsLambda) {}
~ExitFunctionBodyRAII() {
if (!IsLambda)
S.PopExpressionEvaluationContext();
}
private:
Sema &S;
bool IsLambda = false;
};
static void diagnoseImplicitlyRetainedSelf(Sema &S) {
llvm::DenseMap<const BlockDecl *, bool> EscapeInfo;
auto IsOrNestedInEscapingBlock = [&](const BlockDecl *BD) {
auto [It, Inserted] = EscapeInfo.try_emplace(BD);
if (!Inserted)
return It->second;
bool R = false;
const BlockDecl *CurBD = BD;
do {
R = !CurBD->doesNotEscape();
if (R)
break;
CurBD = CurBD->getParent()->getInnermostBlockDecl();
} while (CurBD);
return It->second = R;
};
// If the location where 'self' is implicitly retained is inside a escaping
// block, emit a diagnostic.
for (const std::pair<SourceLocation, const BlockDecl *> &P :
S.ImplicitlyRetainedSelfLocs)
if (IsOrNestedInEscapingBlock(P.second))
S.Diag(P.first, diag::warn_implicitly_retains_self)
<< FixItHint::CreateInsertion(P.first, "self->");
}
static bool methodHasName(const FunctionDecl *FD, StringRef Name) {
return isa<CXXMethodDecl>(FD) && FD->param_empty() &&
FD->getDeclName().isIdentifier() && FD->getName() == Name;
}
bool Sema::CanBeGetReturnObject(const FunctionDecl *FD) {
return methodHasName(FD, "get_return_object");
}
bool Sema::CanBeGetReturnTypeOnAllocFailure(const FunctionDecl *FD) {
return FD->isStatic() &&
methodHasName(FD, "get_return_object_on_allocation_failure");
}
void Sema::CheckCoroutineWrapper(FunctionDecl *FD) {
RecordDecl *RD = FD->getReturnType()->getAsRecordDecl();
if (!RD || !RD->getUnderlyingDecl()->hasAttr<CoroReturnTypeAttr>())
return;
// Allow some_promise_type::get_return_object().
if (CanBeGetReturnObject(FD) || CanBeGetReturnTypeOnAllocFailure(FD))
return;
if (!FD->hasAttr<CoroWrapperAttr>())
Diag(FD->getLocation(), diag::err_coroutine_return_type) << RD;
}
Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body, bool IsInstantiation,
bool RetainFunctionScopeInfo) {
FunctionScopeInfo *FSI = getCurFunction();
FunctionDecl *FD = dcl ? dcl->getAsFunction() : nullptr;
if (FSI->UsesFPIntrin && FD && !FD->hasAttr<StrictFPAttr>())
FD->addAttr(StrictFPAttr::CreateImplicit(Context));
SourceLocation AnalysisLoc;
if (Body)
AnalysisLoc = Body->getEndLoc();
else if (FD)
AnalysisLoc = FD->getEndLoc();
sema::AnalysisBasedWarnings::Policy WP =
AnalysisWarnings.getPolicyInEffectAt(AnalysisLoc);
sema::AnalysisBasedWarnings::Policy *ActivePolicy = nullptr;
// If we skip function body, we can't tell if a function is a coroutine.
if (getLangOpts().Coroutines && FD && !FD->hasSkippedBody()) {
if (FSI->isCoroutine())
CheckCompletedCoroutineBody(FD, Body);
else
CheckCoroutineWrapper(FD);
}
// Diagnose invalid SYCL kernel entry point function declarations
// and build SYCLKernelCallStmts for valid ones.
if (FD && !FD->isInvalidDecl() && FD->hasAttr<SYCLKernelEntryPointAttr>()) {
SYCLKernelEntryPointAttr *SKEPAttr =
FD->getAttr<SYCLKernelEntryPointAttr>();
if (FD->isDefaulted()) {
Diag(SKEPAttr->getLocation(), diag::err_sycl_entry_point_invalid)
<< SKEPAttr << /*defaulted function*/ 3;
SKEPAttr->setInvalidAttr();
} else if (FD->isDeleted()) {
Diag(SKEPAttr->getLocation(), diag::err_sycl_entry_point_invalid)
<< SKEPAttr << /*deleted function*/ 2;
SKEPAttr->setInvalidAttr();
} else if (FSI->isCoroutine()) {
Diag(SKEPAttr->getLocation(), diag::err_sycl_entry_point_invalid)
<< SKEPAttr << /*coroutine*/ 7;
SKEPAttr->setInvalidAttr();
} else if (Body && isa<CXXTryStmt>(Body)) {
Diag(SKEPAttr->getLocation(), diag::err_sycl_entry_point_invalid)
<< SKEPAttr << /*function defined with a function try block*/ 8;
SKEPAttr->setInvalidAttr();
}
if (Body && !FD->isTemplated() && !SKEPAttr->isInvalidAttr()) {
StmtResult SR =
SYCL().BuildSYCLKernelCallStmt(FD, cast<CompoundStmt>(Body));
if (SR.isInvalid())
return nullptr;
Body = SR.get();
}
}
if (FD && !FD->isInvalidDecl() && FD->hasAttr<SYCLExternalAttr>()) {
SYCLExternalAttr *SEAttr = FD->getAttr<SYCLExternalAttr>();
if (FD->isDeletedAsWritten())
Diag(SEAttr->getLocation(),
diag::err_sycl_external_invalid_deleted_function)
<< SEAttr;
}
{
// Do not call PopExpressionEvaluationContext() if it is a lambda because
// one is already popped when finishing the lambda in BuildLambdaExpr().
// This is meant to pop the context added in ActOnStartOfFunctionDef().
ExitFunctionBodyRAII ExitRAII(*this, isLambdaCallOperator(FD));
if (FD) {
// The function body and the DefaultedOrDeletedInfo, if present, use
// the same storage; don't overwrite the latter if the former is null
// (the body is initialised to null anyway, so even if the latter isn't
// present, this would still be a no-op).
if (Body)
FD->setBody(Body);
FD->setWillHaveBody(false);
if (getLangOpts().CPlusPlus14) {
if (!FD->isInvalidDecl() && Body && !FD->isDependentContext() &&
FD->getReturnType()->isUndeducedType()) {
// For a function with a deduced result type to return void,
// the result type as written must be 'auto' or 'decltype(auto)',
// possibly cv-qualified or constrained, but not ref-qualified.
if (!FD->getReturnType()->getAs<AutoType>()) {
Diag(dcl->getLocation(), diag::err_auto_fn_no_return_but_not_auto)
<< FD->getReturnType();
FD->setInvalidDecl();
} else {
// Falling off the end of the function is the same as 'return;'.
Expr *Dummy = nullptr;
if (DeduceFunctionTypeFromReturnExpr(
FD, dcl->getLocation(), Dummy,
FD->getReturnType()->getAs<AutoType>()))
FD->setInvalidDecl();
}
}
} else if (getLangOpts().CPlusPlus && isLambdaCallOperator(FD)) {
// In C++11, we don't use 'auto' deduction rules for lambda call
// operators because we don't support return type deduction.
auto *LSI = getCurLambda();
if (LSI->HasImplicitReturnType) {
deduceClosureReturnType(*LSI);
// C++11 [expr.prim.lambda]p4:
// [...] if there are no return statements in the compound-statement
// [the deduced type is] the type void
QualType RetType =
LSI->ReturnType.isNull() ? Context.VoidTy : LSI->ReturnType;
// Update the return type to the deduced type.
const auto *Proto = FD->getType()->castAs<FunctionProtoType>();
FD->setType(Context.getFunctionType(RetType, Proto->getParamTypes(),
Proto->getExtProtoInfo()));
}
}
// If the function implicitly returns zero (like 'main') or is naked,
// don't complain about missing return statements.
// Clang implicitly returns 0 in C89 mode, but that's considered an
// extension. The check is necessary to ensure the expected extension
// warning is emitted in C89 mode.
if ((FD->hasImplicitReturnZero() &&
(getLangOpts().CPlusPlus || getLangOpts().C99 || !FD->isMain())) ||
FD->hasAttr<NakedAttr>())
WP.disableCheckFallThrough();
// MSVC permits the use of pure specifier (=0) on function definition,
// defined at class scope, warn about this non-standard construct.
if (getLangOpts().MicrosoftExt && FD->isPureVirtual() &&
!FD->isOutOfLine())
Diag(FD->getLocation(), diag::ext_pure_function_definition);
if (!FD->isInvalidDecl()) {
// Don't diagnose unused parameters of defaulted, deleted or naked
// functions.
if (!FD->isDeleted() && !FD->isDefaulted() && !FD->hasSkippedBody() &&
!FD->hasAttr<NakedAttr>())
DiagnoseUnusedParameters(FD->parameters());
DiagnoseSizeOfParametersAndReturnValue(FD->parameters(),
FD->getReturnType(), FD);
// If this is a structor, we need a vtable.
if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(FD))
MarkVTableUsed(FD->getLocation(), Constructor->getParent());
else if (CXXDestructorDecl *Destructor =
dyn_cast<CXXDestructorDecl>(FD))
MarkVTableUsed(FD->getLocation(), Destructor->getParent());
// Try to apply the named return value optimization. We have to check
// if we can do this here because lambdas keep return statements around
// to deduce an implicit return type.
if (FD->getReturnType()->isRecordType() &&
(!getLangOpts().CPlusPlus || !FD->isDependentContext()))
computeNRVO(Body, FSI);
}
// GNU warning -Wmissing-prototypes:
// Warn if a global function is defined without a previous
// prototype declaration. This warning is issued even if the
// definition itself provides a prototype. The aim is to detect
// global functions that fail to be declared in header files.
const FunctionDecl *PossiblePrototype = nullptr;
if (ShouldWarnAboutMissingPrototype(FD, PossiblePrototype)) {
Diag(FD->getLocation(), diag::warn_missing_prototype) << FD;
if (PossiblePrototype) {
// We found a declaration that is not a prototype,
// but that could be a zero-parameter prototype
if (TypeSourceInfo *TI = PossiblePrototype->getTypeSourceInfo()) {
TypeLoc TL = TI->getTypeLoc();
if (FunctionNoProtoTypeLoc FTL = TL.getAs<FunctionNoProtoTypeLoc>())
Diag(PossiblePrototype->getLocation(),
diag::note_declaration_not_a_prototype)
<< (FD->getNumParams() != 0)
<< (FD->getNumParams() == 0 ? FixItHint::CreateInsertion(
FTL.getRParenLoc(), "void")
: FixItHint{});
}
} else {
// Returns true if the token beginning at this Loc is `const`.
auto isLocAtConst = [&](SourceLocation Loc, const SourceManager &SM,
const LangOptions &LangOpts) {
FileIDAndOffset LocInfo = SM.getDecomposedLoc(Loc);
if (LocInfo.first.isInvalid())
return false;
bool Invalid = false;
StringRef Buffer = SM.getBufferData(LocInfo.first, &Invalid);
if (Invalid)
return false;
if (LocInfo.second > Buffer.size())
return false;
const char *LexStart = Buffer.data() + LocInfo.second;
StringRef StartTok(LexStart, Buffer.size() - LocInfo.second);
return StartTok.consume_front("const") &&
(StartTok.empty() || isWhitespace(StartTok[0]) ||
StartTok.starts_with("/*") || StartTok.starts_with("//"));
};
auto findBeginLoc = [&]() {
// If the return type has `const` qualifier, we want to insert
// `static` before `const` (and not before the typename).
if ((FD->getReturnType()->isAnyPointerType() &&
FD->getReturnType()->getPointeeType().isConstQualified()) ||
FD->getReturnType().isConstQualified()) {
// But only do this if we can determine where the `const` is.
if (isLocAtConst(FD->getBeginLoc(), getSourceManager(),
getLangOpts()))
return FD->getBeginLoc();
}
return FD->getTypeSpecStartLoc();
};
Diag(FD->getTypeSpecStartLoc(),
diag::note_static_for_internal_linkage)
<< /* function */ 1
<< (FD->getStorageClass() == SC_None
? FixItHint::CreateInsertion(findBeginLoc(), "static ")
: FixItHint{});
}
}
// We might not have found a prototype because we didn't wish to warn on
// the lack of a missing prototype. Try again without the checks for
// whether we want to warn on the missing prototype.
if (!PossiblePrototype)
(void)FindPossiblePrototype(FD, PossiblePrototype);
// If the function being defined does not have a prototype, then we may
// need to diagnose it as changing behavior in C23 because we now know
// whether the function accepts arguments or not. This only handles the
// case where the definition has no prototype but does have parameters
// and either there is no previous potential prototype, or the previous
// potential prototype also has no actual prototype. This handles cases
// like:
// void f(); void f(a) int a; {}
// void g(a) int a; {}
// See MergeFunctionDecl() for other cases of the behavior change
// diagnostic. See GetFullTypeForDeclarator() for handling of a function
// type without a prototype.
if (!FD->hasWrittenPrototype() && FD->getNumParams() != 0 &&
(!PossiblePrototype || (!PossiblePrototype->hasWrittenPrototype() &&
!PossiblePrototype->isImplicit()))) {
// The function definition has parameters, so this will change behavior
// in C23. If there is a possible prototype, it comes before the
// function definition.
// FIXME: The declaration may have already been diagnosed as being
// deprecated in GetFullTypeForDeclarator() if it had no arguments, but
// there's no way to test for the "changes behavior" condition in
// SemaType.cpp when forming the declaration's function type. So, we do
// this awkward dance instead.
//
// If we have a possible prototype and it declares a function with a
// prototype, we don't want to diagnose it; if we have a possible
// prototype and it has no prototype, it may have already been
// diagnosed in SemaType.cpp as deprecated depending on whether
// -Wstrict-prototypes is enabled. If we already warned about it being
// deprecated, add a note that it also changes behavior. If we didn't
// warn about it being deprecated (because the diagnostic is not
// enabled), warn now that it is deprecated and changes behavior.
// This K&R C function definition definitely changes behavior in C23,
// so diagnose it.
Diag(FD->getLocation(), diag::warn_non_prototype_changes_behavior)
<< /*definition*/ 1 << /* not supported in C23 */ 0;
// If we have a possible prototype for the function which is a user-
// visible declaration, we already tested that it has no prototype.
// This will change behavior in C23. This gets a warning rather than a
// note because it's the same behavior-changing problem as with the
// definition.
if (PossiblePrototype)
Diag(PossiblePrototype->getLocation(),
diag::warn_non_prototype_changes_behavior)
<< /*declaration*/ 0 << /* conflicting */ 1 << /*subsequent*/ 1
<< /*definition*/ 1;
}
// Warn on CPUDispatch with an actual body.
if (FD->isMultiVersion() && FD->hasAttr<CPUDispatchAttr>() && Body)
if (const auto *CmpndBody = dyn_cast<CompoundStmt>(Body))
if (!CmpndBody->body_empty())
Diag(CmpndBody->body_front()->getBeginLoc(),
diag::warn_dispatch_body_ignored);
if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
const CXXMethodDecl *KeyFunction;
if (MD->isOutOfLine() && (MD = MD->getCanonicalDecl()) &&
MD->isVirtual() &&
(KeyFunction = Context.getCurrentKeyFunction(MD->getParent())) &&
MD == KeyFunction->getCanonicalDecl()) {
// Update the key-function state if necessary for this ABI.
if (FD->isInlined() &&
!Context.getTargetInfo().getCXXABI().canKeyFunctionBeInline()) {
Context.setNonKeyFunction(MD);
// If the newly-chosen key function is already defined, then we
// need to mark the vtable as used retroactively.
KeyFunction = Context.getCurrentKeyFunction(MD->getParent());
const FunctionDecl *Definition;
if (KeyFunction && KeyFunction->isDefined(Definition))
MarkVTableUsed(Definition->getLocation(), MD->getParent(), true);
} else {
// We just defined they key function; mark the vtable as used.
MarkVTableUsed(FD->getLocation(), MD->getParent(), true);
}
}
}
assert((FD == getCurFunctionDecl(/*AllowLambdas=*/true)) &&
"Function parsing confused");
} else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) {
assert(MD == getCurMethodDecl() && "Method parsing confused");
MD->setBody(Body);
if (!MD->isInvalidDecl()) {
DiagnoseSizeOfParametersAndReturnValue(MD->parameters(),
MD->getReturnType(), MD);
if (Body)
computeNRVO(Body, FSI);
}
if (FSI->ObjCShouldCallSuper) {
Diag(MD->getEndLoc(), diag::warn_objc_missing_super_call)
<< MD->getSelector().getAsString();
FSI->ObjCShouldCallSuper = false;
}
if (FSI->ObjCWarnForNoDesignatedInitChain) {
const ObjCMethodDecl *InitMethod = nullptr;
bool isDesignated =
MD->isDesignatedInitializerForTheInterface(&InitMethod);
assert(isDesignated && InitMethod);
(void)isDesignated;
auto superIsNSObject = [&](const ObjCMethodDecl *MD) {
auto IFace = MD->getClassInterface();
if (!IFace)
return false;
auto SuperD = IFace->getSuperClass();
if (!SuperD)
return false;
return SuperD->getIdentifier() ==
ObjC().NSAPIObj->getNSClassId(NSAPI::ClassId_NSObject);
};
// Don't issue this warning for unavailable inits or direct subclasses
// of NSObject.
if (!MD->isUnavailable() && !superIsNSObject(MD)) {
Diag(MD->getLocation(),
diag::warn_objc_designated_init_missing_super_call);
Diag(InitMethod->getLocation(),
diag::note_objc_designated_init_marked_here);
}
FSI->ObjCWarnForNoDesignatedInitChain = false;
}
if (FSI->ObjCWarnForNoInitDelegation) {
// Don't issue this warning for unavailable inits.
if (!MD->isUnavailable())
Diag(MD->getLocation(),
diag::warn_objc_secondary_init_missing_init_call);
FSI->ObjCWarnForNoInitDelegation = false;
}
diagnoseImplicitlyRetainedSelf(*this);
} else {
// Parsing the function declaration failed in some way. Pop the fake scope
// we pushed on.
PopFunctionScopeInfo(ActivePolicy, dcl);
return nullptr;
}
if (Body && FSI->HasPotentialAvailabilityViolations)
DiagnoseUnguardedAvailabilityViolations(dcl);
assert(!FSI->ObjCShouldCallSuper &&
"This should only be set for ObjC methods, which should have been "
"handled in the block above.");
// Verify and clean out per-function state.
if (Body && (!FD || !FD->isDefaulted())) {
// C++ constructors that have function-try-blocks can't have return
// statements in the handlers of that block. (C++ [except.handle]p14)
// Verify this.
if (FD && isa<CXXConstructorDecl>(FD) && isa<CXXTryStmt>(Body))
DiagnoseReturnInConstructorExceptionHandler(cast<CXXTryStmt>(Body));
// Verify that gotos and switch cases don't jump into scopes illegally.
if (FSI->NeedsScopeChecking() && !PP.isCodeCompletionEnabled())
DiagnoseInvalidJumps(Body);
if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(dcl)) {
if (!Destructor->getParent()->isDependentType())
CheckDestructor(Destructor);
MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(),
Destructor->getParent());
}
// If any errors have occurred, clear out any temporaries that may have
// been leftover. This ensures that these temporaries won't be picked up
// for deletion in some later function.
if (hasUncompilableErrorOccurred() ||
hasAnyUnrecoverableErrorsInThisFunction() ||
getDiagnostics().getSuppressAllDiagnostics()) {
DiscardCleanupsInEvaluationContext();
}
if (!hasUncompilableErrorOccurred() && !isa<FunctionTemplateDecl>(dcl)) {
// Since the body is valid, issue any analysis-based warnings that are
// enabled.
ActivePolicy = &WP;
}
if (!IsInstantiation && FD &&
(FD->isConstexpr() || FD->hasAttr<MSConstexprAttr>()) &&
!FD->isInvalidDecl() &&
!CheckConstexprFunctionDefinition(FD, CheckConstexprKind::Diagnose))
FD->setInvalidDecl();
if (FD && FD->hasAttr<NakedAttr>()) {
for (const Stmt *S : Body->children()) {
// Allow local register variables without initializer as they don't
// require prologue.
bool RegisterVariables = false;
if (auto *DS = dyn_cast<DeclStmt>(S)) {
for (const auto *Decl : DS->decls()) {
if (const auto *Var = dyn_cast<VarDecl>(Decl)) {
RegisterVariables =
Var->hasAttr<AsmLabelAttr>() && !Var->hasInit();
if (!RegisterVariables)
break;
}
}
}
if (RegisterVariables)
continue;
if (!isa<AsmStmt>(S) && !isa<NullStmt>(S)) {
Diag(S->getBeginLoc(), diag::err_non_asm_stmt_in_naked_function);
Diag(FD->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);
FD->setInvalidDecl();
break;
}
}
}
assert(ExprCleanupObjects.size() ==
ExprEvalContexts.back().NumCleanupObjects &&
"Leftover temporaries in function");
assert(!Cleanup.exprNeedsCleanups() &&
"Unaccounted cleanups in function");
assert(MaybeODRUseExprs.empty() &&
"Leftover expressions for odr-use checking");
}
} // Pops the ExitFunctionBodyRAII scope, which needs to happen before we pop
// the declaration context below. Otherwise, we're unable to transform
// 'this' expressions when transforming immediate context functions.
if (FD)
CheckImmediateEscalatingFunctionDefinition(FD, getCurFunction());
if (!IsInstantiation)
PopDeclContext();
if (!RetainFunctionScopeInfo)
PopFunctionScopeInfo(ActivePolicy, dcl);
// If any errors have occurred, clear out any temporaries that may have
// been leftover. This ensures that these temporaries won't be picked up for
// deletion in some later function.
if (hasUncompilableErrorOccurred()) {
DiscardCleanupsInEvaluationContext();
}
if (FD && (LangOpts.isTargetDevice() || LangOpts.CUDA ||
(LangOpts.OpenMP && !LangOpts.OMPTargetTriples.empty()))) {
auto ES = getEmissionStatus(FD);
if (ES == Sema::FunctionEmissionStatus::Emitted ||
ES == Sema::FunctionEmissionStatus::Unknown)
DeclsToCheckForDeferredDiags.insert(FD);
}
if (FD && !FD->isDeleted())
checkTypeSupport(FD->getType(), FD->getLocation(), FD);
return dcl;
}
/// When we finish delayed parsing of an attribute, we must attach it to the
/// relevant Decl.
void Sema::ActOnFinishDelayedAttribute(Scope *S, Decl *D,
ParsedAttributes &Attrs) {
// Always attach attributes to the underlying decl.
if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
D = TD->getTemplatedDecl();
ProcessDeclAttributeList(S, D, Attrs);
ProcessAPINotes(D);
if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(D))
if (Method->isStatic())
checkThisInStaticMemberFunctionAttributes(Method);
}
NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc,
IdentifierInfo &II, Scope *S) {
// It is not valid to implicitly define a function in C23.
assert(LangOpts.implicitFunctionsAllowed() &&
"Implicit function declarations aren't allowed in this language mode");
// Find the scope in which the identifier is injected and the corresponding
// DeclContext.
// FIXME: C89 does not say what happens if there is no enclosing block scope.
// In that case, we inject the declaration into the translation unit scope
// instead.
Scope *BlockScope = S;
while (!BlockScope->isCompoundStmtScope() && BlockScope->getParent())
BlockScope = BlockScope->getParent();
// Loop until we find a DeclContext that is either a function/method or the
// translation unit, which are the only two valid places to implicitly define
// a function. This avoids accidentally defining the function within a tag
// declaration, for example.
Scope *ContextScope = BlockScope;
while (!ContextScope->getEntity() ||
(!ContextScope->getEntity()->isFunctionOrMethod() &&
!ContextScope->getEntity()->isTranslationUnit()))
ContextScope = ContextScope->getParent();
ContextRAII SavedContext(*this, ContextScope->getEntity());
// Before we produce a declaration for an implicitly defined
// function, see whether there was a locally-scoped declaration of
// this name as a function or variable. If so, use that
// (non-visible) declaration, and complain about it.
NamedDecl *ExternCPrev = findLocallyScopedExternCDecl(&II);
if (ExternCPrev) {
// We still need to inject the function into the enclosing block scope so
// that later (non-call) uses can see it.
PushOnScopeChains(ExternCPrev, BlockScope, /*AddToContext*/false);
// C89 footnote 38:
// If in fact it is not defined as having type "function returning int",
// the behavior is undefined.
if (!isa<FunctionDecl>(ExternCPrev) ||
!Context.typesAreCompatible(
cast<FunctionDecl>(ExternCPrev)->getType(),
Context.getFunctionNoProtoType(Context.IntTy))) {
Diag(Loc, diag::ext_use_out_of_scope_declaration)
<< ExternCPrev << !getLangOpts().C99;
Diag(ExternCPrev->getLocation(), diag::note_previous_declaration);
return ExternCPrev;
}
}
// Extension in C99 (defaults to error). Legal in C89, but warn about it.
unsigned diag_id;
if (II.getName().starts_with("__builtin_"))
diag_id = diag::warn_builtin_unknown;
// OpenCL v2.0 s6.9.u - Implicit function declaration is not supported.
else if (getLangOpts().C99)
diag_id = diag::ext_implicit_function_decl_c99;
else
diag_id = diag::warn_implicit_function_decl;
TypoCorrection Corrected;
// Because typo correction is expensive, only do it if the implicit
// function declaration is going to be treated as an error.
//
// Perform the correction before issuing the main diagnostic, as some
// consumers use typo-correction callbacks to enhance the main diagnostic.
if (S && !ExternCPrev &&
(Diags.getDiagnosticLevel(diag_id, Loc) >= DiagnosticsEngine::Error)) {
DeclFilterCCC<FunctionDecl> CCC{};
Corrected = CorrectTypo(DeclarationNameInfo(&II, Loc), LookupOrdinaryName,
S, nullptr, CCC, CorrectTypoKind::NonError);
}
Diag(Loc, diag_id) << &II;
if (Corrected) {
// If the correction is going to suggest an implicitly defined function,
// skip the correction as not being a particularly good idea.
bool Diagnose = true;
if (const auto *D = Corrected.getCorrectionDecl())
Diagnose = !D->isImplicit();
if (Diagnose)
diagnoseTypo(Corrected, PDiag(diag::note_function_suggestion),
/*ErrorRecovery*/ false);
}
// If we found a prior declaration of this function, don't bother building
// another one. We've already pushed that one into scope, so there's nothing
// more to do.
if (ExternCPrev)
return ExternCPrev;
// Set a Declarator for the implicit definition: int foo();
const char *Dummy;
AttributeFactory attrFactory;
DeclSpec DS(attrFactory);
unsigned DiagID;
bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy, DiagID,
Context.getPrintingPolicy());
(void)Error; // Silence warning.
assert(!Error && "Error setting up implicit decl!");
SourceLocation NoLoc;
Declarator D(DS, ParsedAttributesView::none(), DeclaratorContext::Block);
D.AddTypeInfo(DeclaratorChunk::getFunction(/*HasProto=*/false,
/*IsAmbiguous=*/false,
/*LParenLoc=*/NoLoc,
/*Params=*/nullptr,
/*NumParams=*/0,
/*EllipsisLoc=*/NoLoc,
/*RParenLoc=*/NoLoc,
/*RefQualifierIsLvalueRef=*/true,
/*RefQualifierLoc=*/NoLoc,
/*MutableLoc=*/NoLoc, EST_None,
/*ESpecRange=*/SourceRange(),
/*Exceptions=*/nullptr,
/*ExceptionRanges=*/nullptr,
/*NumExceptions=*/0,
/*NoexceptExpr=*/nullptr,
/*ExceptionSpecTokens=*/nullptr,
/*DeclsInPrototype=*/{}, Loc, Loc,
D),
std::move(DS.getAttributes()), SourceLocation());
D.SetIdentifier(&II, Loc);
// Insert this function into the enclosing block scope.
FunctionDecl *FD = cast<FunctionDecl>(ActOnDeclarator(BlockScope, D));
FD->setImplicit();
AddKnownFunctionAttributes(FD);
return FD;
}
void Sema::AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction(
FunctionDecl *FD) {
if (FD->isInvalidDecl())
return;
if (FD->getDeclName().getCXXOverloadedOperator() != OO_New &&
FD->getDeclName().getCXXOverloadedOperator() != OO_Array_New)
return;
UnsignedOrNone AlignmentParam = std::nullopt;
bool IsNothrow = false;
if (!FD->isReplaceableGlobalAllocationFunction(&AlignmentParam, &IsNothrow))
return;
// C++2a [basic.stc.dynamic.allocation]p4:
// An allocation function that has a non-throwing exception specification
// indicates failure by returning a null pointer value. Any other allocation
// function never returns a null pointer value and indicates failure only by
// throwing an exception [...]
//
// However, -fcheck-new invalidates this possible assumption, so don't add
// NonNull when that is enabled.
if (!IsNothrow && !FD->hasAttr<ReturnsNonNullAttr>() &&
!getLangOpts().CheckNew)
FD->addAttr(ReturnsNonNullAttr::CreateImplicit(Context, FD->getLocation()));
// C++2a [basic.stc.dynamic.allocation]p2:
// An allocation function attempts to allocate the requested amount of
// storage. [...] If the request succeeds, the value returned by a
// replaceable allocation function is a [...] pointer value p0 different
// from any previously returned value p1 [...]
//
// However, this particular information is being added in codegen,
// because there is an opt-out switch for it (-fno-assume-sane-operator-new)
// C++2a [basic.stc.dynamic.allocation]p2:
// An allocation function attempts to allocate the requested amount of
// storage. If it is successful, it returns the address of the start of a
// block of storage whose length in bytes is at least as large as the
// requested size.
if (!FD->hasAttr<AllocSizeAttr>()) {
FD->addAttr(AllocSizeAttr::CreateImplicit(
Context, /*ElemSizeParam=*/ParamIdx(1, FD),
/*NumElemsParam=*/ParamIdx(), FD->getLocation()));
}
// C++2a [basic.stc.dynamic.allocation]p3:
// For an allocation function [...], the pointer returned on a successful
// call shall represent the address of storage that is aligned as follows:
// (3.1) If the allocation function takes an argument of type
// std​::​align_­val_­t, the storage will have the alignment
// specified by the value of this argument.
if (AlignmentParam && !FD->hasAttr<AllocAlignAttr>()) {
FD->addAttr(AllocAlignAttr::CreateImplicit(
Context, ParamIdx(*AlignmentParam, FD), FD->getLocation()));
}
// FIXME:
// C++2a [basic.stc.dynamic.allocation]p3:
// For an allocation function [...], the pointer returned on a successful
// call shall represent the address of storage that is aligned as follows:
// (3.2) Otherwise, if the allocation function is named operator new[],
// the storage is aligned for any object that does not have
// new-extended alignment ([basic.align]) and is no larger than the
// requested size.
// (3.3) Otherwise, the storage is aligned for any object that does not
// have new-extended alignment and is of the requested size.
}
void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) {
if (FD->isInvalidDecl())
return;
// If this is a built-in function, map its builtin attributes to
// actual attributes.
if (unsigned BuiltinID = FD->getBuiltinID()) {
// Handle printf-formatting attributes.
unsigned FormatIdx;
bool HasVAListArg;
if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) {
if (!FD->hasAttr<FormatAttr>()) {
const char *fmt = "printf";
unsigned int NumParams = FD->getNumParams();
if (FormatIdx < NumParams && // NumParams may be 0 (e.g. vfprintf)
FD->getParamDecl(FormatIdx)->getType()->isObjCObjectPointerType())
fmt = "NSString";
FD->addAttr(FormatAttr::CreateImplicit(Context,
&Context.Idents.get(fmt),
FormatIdx+1,
HasVAListArg ? 0 : FormatIdx+2,
FD->getLocation()));
}
}
if (Context.BuiltinInfo.isScanfLike(BuiltinID, FormatIdx,
HasVAListArg)) {
if (!FD->hasAttr<FormatAttr>())
FD->addAttr(FormatAttr::CreateImplicit(Context,
&Context.Idents.get("scanf"),
FormatIdx+1,
HasVAListArg ? 0 : FormatIdx+2,
FD->getLocation()));
}
// Handle automatically recognized callbacks.
SmallVector<int, 4> Encoding;
if (!FD->hasAttr<CallbackAttr>() &&
Context.BuiltinInfo.performsCallback(BuiltinID, Encoding))
FD->addAttr(CallbackAttr::CreateImplicit(
Context, Encoding.data(), Encoding.size(), FD->getLocation()));
// Mark const if we don't care about errno and/or floating point exceptions
// that are the only thing preventing the function from being const. This
// allows IRgen to use LLVM intrinsics for such functions.
bool NoExceptions =
getLangOpts().getDefaultExceptionMode() == LangOptions::FPE_Ignore;
bool ConstWithoutErrnoAndExceptions =
Context.BuiltinInfo.isConstWithoutErrnoAndExceptions(BuiltinID);
bool ConstWithoutExceptions =
Context.BuiltinInfo.isConstWithoutExceptions(BuiltinID);
if (!FD->hasAttr<ConstAttr>() &&
(ConstWithoutErrnoAndExceptions || ConstWithoutExceptions) &&
(!ConstWithoutErrnoAndExceptions ||
(!getLangOpts().MathErrno && NoExceptions)) &&
(!ConstWithoutExceptions || NoExceptions))
FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation()));
// We make "fma" on GNU or Windows const because we know it does not set
// errno in those environments even though it could set errno based on the
// C standard.
const llvm::Triple &Trip = Context.getTargetInfo().getTriple();
if ((Trip.isGNUEnvironment() || Trip.isOSMSVCRT()) &&
!FD->hasAttr<ConstAttr>()) {
switch (BuiltinID) {
case Builtin::BI__builtin_fma:
case Builtin::BI__builtin_fmaf:
case Builtin::BI__builtin_fmal:
case Builtin::BIfma:
case Builtin::BIfmaf:
case Builtin::BIfmal:
FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation()));
break;
default:
break;
}
}
if (Context.BuiltinInfo.isReturnsTwice(BuiltinID) &&
!FD->hasAttr<ReturnsTwiceAttr>())
FD->addAttr(ReturnsTwiceAttr::CreateImplicit(Context,
FD->getLocation()));
if (Context.BuiltinInfo.isNoThrow(BuiltinID) && !FD->hasAttr<NoThrowAttr>())
FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation()));
if (Context.BuiltinInfo.isPure(BuiltinID) && !FD->hasAttr<PureAttr>())
FD->addAttr(PureAttr::CreateImplicit(Context, FD->getLocation()));
if (Context.BuiltinInfo.isConst(BuiltinID) && !FD->hasAttr<ConstAttr>())
FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation()));
if (getLangOpts().CUDA && Context.BuiltinInfo.isTSBuiltin(BuiltinID) &&
!FD->hasAttr<CUDADeviceAttr>() && !FD->hasAttr<CUDAHostAttr>()) {
// Add the appropriate attribute, depending on the CUDA compilation mode
// and which target the builtin belongs to. For example, during host
// compilation, aux builtins are __device__, while the rest are __host__.
if (getLangOpts().CUDAIsDevice !=
Context.BuiltinInfo.isAuxBuiltinID(BuiltinID))
FD->addAttr(CUDADeviceAttr::CreateImplicit(Context, FD->getLocation()));
else
FD->addAttr(CUDAHostAttr::CreateImplicit(Context, FD->getLocation()));
}
// Add known guaranteed alignment for allocation functions.
switch (BuiltinID) {
case Builtin::BImemalign:
case Builtin::BIaligned_alloc:
if (!FD->hasAttr<AllocAlignAttr>())
FD->addAttr(AllocAlignAttr::CreateImplicit(Context, ParamIdx(1, FD),
FD->getLocation()));
break;
default:
break;
}
// Add allocsize attribute for allocation functions.
switch (BuiltinID) {
case Builtin::BIcalloc:
FD->addAttr(AllocSizeAttr::CreateImplicit(
Context, ParamIdx(1, FD), ParamIdx(2, FD), FD->getLocation()));
break;
case Builtin::BImemalign:
case Builtin::BIaligned_alloc:
case Builtin::BIrealloc:
FD->addAttr(AllocSizeAttr::CreateImplicit(Context, ParamIdx(2, FD),
ParamIdx(), FD->getLocation()));
break;
case Builtin::BImalloc:
FD->addAttr(AllocSizeAttr::CreateImplicit(Context, ParamIdx(1, FD),
ParamIdx(), FD->getLocation()));
break;
default:
break;
}
}
LazyProcessLifetimeCaptureByParams(FD);
inferLifetimeBoundAttribute(FD);
inferLifetimeCaptureByAttribute(FD);
AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction(FD);
// If C++ exceptions are enabled but we are told extern "C" functions cannot
// throw, add an implicit nothrow attribute to any extern "C" function we come
// across.
if (getLangOpts().CXXExceptions && getLangOpts().ExternCNoUnwind &&
FD->isExternC() && !FD->hasAttr<NoThrowAttr>()) {
const auto *FPT = FD->getType()->getAs<FunctionProtoType>();
if (!FPT || FPT->getExceptionSpecType() == EST_None)
FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation()));
}
IdentifierInfo *Name = FD->getIdentifier();
if (!Name)
return;
if ((!getLangOpts().CPlusPlus && FD->getDeclContext()->isTranslationUnit()) ||
(isa<LinkageSpecDecl>(FD->getDeclContext()) &&
cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() ==
LinkageSpecLanguageIDs::C)) {
// Okay: this could be a libc/libm/Objective-C function we know
// about.
} else
return;
if (Name->isStr("asprintf") || Name->isStr("vasprintf")) {
// FIXME: asprintf and vasprintf aren't C99 functions. Should they be
// target-specific builtins, perhaps?
if (!FD->hasAttr<FormatAttr>())
FD->addAttr(FormatAttr::CreateImplicit(Context,
&Context.Idents.get("printf"), 2,
Name->isStr("vasprintf") ? 0 : 3,
FD->getLocation()));
}
if (Name->isStr("__CFStringMakeConstantString")) {
// We already have a __builtin___CFStringMakeConstantString,
// but builds that use -fno-constant-cfstrings don't go through that.
if (!FD->hasAttr<FormatArgAttr>())
FD->addAttr(FormatArgAttr::CreateImplicit(Context, ParamIdx(1, FD),
FD->getLocation()));
}
}
TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T,
TypeSourceInfo *TInfo) {
assert(D.getIdentifier() && "Wrong callback for declspec without declarator");
assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
if (!TInfo) {
assert(D.isInvalidType() && "no declarator info for valid type");
TInfo = Context.getTrivialTypeSourceInfo(T);
}
// Scope manipulation handled by caller.
TypedefDecl *NewTD =
TypedefDecl::Create(Context, CurContext, D.getBeginLoc(),
D.getIdentifierLoc(), D.getIdentifier(), TInfo);
// Bail out immediately if we have an invalid declaration.
if (D.isInvalidType()) {
NewTD->setInvalidDecl();
return NewTD;
}
if (D.getDeclSpec().isModulePrivateSpecified()) {
if (CurContext->isFunctionOrMethod())
Diag(NewTD->getLocation(), diag::err_module_private_local)
<< 2 << NewTD
<< SourceRange(D.getDeclSpec().getModulePrivateSpecLoc())
<< FixItHint::CreateRemoval(
D.getDeclSpec().getModulePrivateSpecLoc());
else
NewTD->setModulePrivate();
}
// C++ [dcl.typedef]p8:
// If the typedef declaration defines an unnamed class (or
// enum), the first typedef-name declared by the declaration
// to be that class type (or enum type) is used to denote the
// class type (or enum type) for linkage purposes only.
// We need to check whether the type was declared in the declaration.
switch (D.getDeclSpec().getTypeSpecType()) {
case TST_enum:
case TST_struct:
case TST_interface:
case TST_union:
case TST_class: {
TagDecl *tagFromDeclSpec = cast<TagDecl>(D.getDeclSpec().getRepAsDecl());
setTagNameForLinkagePurposes(tagFromDeclSpec, NewTD);
break;
}
default:
break;
}
return NewTD;
}
bool Sema::CheckEnumUnderlyingType(TypeSourceInfo *TI) {
SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
QualType T = TI->getType();
if (T->isDependentType())
return false;
// C++0x 7.2p2: The type-specifier-seq of an enum-base shall name an
// integral type; any cv-qualification is ignored.
// C23 6.7.3.3p5: The underlying type of the enumeration is the unqualified,
// non-atomic version of the type specified by the type specifiers in the
// specifier qualifier list.
// Because of how odd C's rule is, we'll let the user know that operations
// involving the enumeration type will be non-atomic.
if (T->isAtomicType())
Diag(UnderlyingLoc, diag::warn_atomic_stripped_in_enum);
Qualifiers Q = T.getQualifiers();
std::optional<unsigned> QualSelect;
if (Q.hasConst() && Q.hasVolatile())
QualSelect = diag::CVQualList::Both;
else if (Q.hasConst())
QualSelect = diag::CVQualList::Const;
else if (Q.hasVolatile())
QualSelect = diag::CVQualList::Volatile;
if (QualSelect)
Diag(UnderlyingLoc, diag::warn_cv_stripped_in_enum) << *QualSelect;
T = T.getAtomicUnqualifiedType();
// This doesn't use 'isIntegralType' despite the error message mentioning
// integral type because isIntegralType would also allow enum types in C.
if (const BuiltinType *BT = T->getAs<BuiltinType>())
if (BT->isInteger())
return false;
return Diag(UnderlyingLoc, diag::err_enum_invalid_underlying)
<< T << T->isBitIntType();
}
bool Sema::CheckEnumRedeclaration(SourceLocation EnumLoc, bool IsScoped,
QualType EnumUnderlyingTy, bool IsFixed,
const EnumDecl *Prev) {
if (IsScoped != Prev->isScoped()) {
Diag(EnumLoc, diag::err_enum_redeclare_scoped_mismatch)
<< Prev->isScoped();
Diag(Prev->getLocation(), diag::note_previous_declaration);
return true;
}
if (IsFixed && Prev->isFixed()) {
if (!EnumUnderlyingTy->isDependentType() &&
!Prev->getIntegerType()->isDependentType() &&
!Context.hasSameUnqualifiedType(EnumUnderlyingTy,
Prev->getIntegerType())) {
// TODO: Highlight the underlying type of the redeclaration.
Diag(EnumLoc, diag::err_enum_redeclare_type_mismatch)
<< EnumUnderlyingTy << Prev->getIntegerType();
Diag(Prev->getLocation(), diag::note_previous_declaration)
<< Prev->getIntegerTypeRange();
return true;
}
} else if (IsFixed != Prev->isFixed()) {
Diag(EnumLoc, diag::err_enum_redeclare_fixed_mismatch)
<< Prev->isFixed();
Diag(Prev->getLocation(), diag::note_previous_declaration);
return true;
}
return false;
}
/// Get diagnostic %select index for tag kind for
/// redeclaration diagnostic message.
/// WARNING: Indexes apply to particular diagnostics only!
///
/// \returns diagnostic %select index.
static unsigned getRedeclDiagFromTagKind(TagTypeKind Tag) {
switch (Tag) {
case TagTypeKind::Struct:
return 0;
case TagTypeKind::Interface:
return 1;
case TagTypeKind::Class:
return 2;
default: llvm_unreachable("Invalid tag kind for redecl diagnostic!");
}
}
/// Determine if tag kind is a class-key compatible with
/// class for redeclaration (class, struct, or __interface).
///
/// \returns true iff the tag kind is compatible.
static bool isClassCompatTagKind(TagTypeKind Tag)
{
return Tag == TagTypeKind::Struct || Tag == TagTypeKind::Class ||
Tag == TagTypeKind::Interface;
}
NonTagKind Sema::getNonTagTypeDeclKind(const Decl *PrevDecl, TagTypeKind TTK) {
if (isa<TypedefDecl>(PrevDecl))
return NonTagKind::Typedef;
else if (isa<TypeAliasDecl>(PrevDecl))
return NonTagKind::TypeAlias;
else if (isa<ClassTemplateDecl>(PrevDecl))
return NonTagKind::Template;
else if (isa<TypeAliasTemplateDecl>(PrevDecl))
return NonTagKind::TypeAliasTemplate;
else if (isa<TemplateTemplateParmDecl>(PrevDecl))
return NonTagKind::TemplateTemplateArgument;
switch (TTK) {
case TagTypeKind::Struct:
case TagTypeKind::Interface:
case TagTypeKind::Class:
return getLangOpts().CPlusPlus ? NonTagKind::NonClass
: NonTagKind::NonStruct;
case TagTypeKind::Union:
return NonTagKind::NonUnion;
case TagTypeKind::Enum:
return NonTagKind::NonEnum;
}
llvm_unreachable("invalid TTK");
}
bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous,
TagTypeKind NewTag, bool isDefinition,
SourceLocation NewTagLoc,
const IdentifierInfo *Name) {
// C++ [dcl.type.elab]p3:
// The class-key or enum keyword present in the
// elaborated-type-specifier shall agree in kind with the
// declaration to which the name in the elaborated-type-specifier
// refers. This rule also applies to the form of
// elaborated-type-specifier that declares a class-name or
// friend class since it can be construed as referring to the
// definition of the class. Thus, in any
// elaborated-type-specifier, the enum keyword shall be used to
// refer to an enumeration (7.2), the union class-key shall be
// used to refer to a union (clause 9), and either the class or
// struct class-key shall be used to refer to a class (clause 9)
// declared using the class or struct class-key.
TagTypeKind OldTag = Previous->getTagKind();
if (OldTag != NewTag &&
!(isClassCompatTagKind(OldTag) && isClassCompatTagKind(NewTag)))
return false;
// Tags are compatible, but we might still want to warn on mismatched tags.
// Non-class tags can't be mismatched at this point.
if (!isClassCompatTagKind(NewTag))
return true;
// Declarations for which -Wmismatched-tags is disabled are entirely ignored
// by our warning analysis. We don't want to warn about mismatches with (eg)
// declarations in system headers that are designed to be specialized, but if
// a user asks us to warn, we should warn if their code contains mismatched
// declarations.
auto IsIgnoredLoc = [&](SourceLocation Loc) {
return getDiagnostics().isIgnored(diag::warn_struct_class_tag_mismatch,
Loc);
};
if (IsIgnoredLoc(NewTagLoc))
return true;
auto IsIgnored = [&](const TagDecl *Tag) {
return IsIgnoredLoc(Tag->getLocation());
};
while (IsIgnored(Previous)) {
Previous = Previous->getPreviousDecl();
if (!Previous)
return true;
OldTag = Previous->getTagKind();
}
bool isTemplate = false;
if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Previous))
isTemplate = Record->getDescribedClassTemplate();
if (inTemplateInstantiation()) {
if (OldTag != NewTag) {
// In a template instantiation, do not offer fix-its for tag mismatches
// since they usually mess up the template instead of fixing the problem.
Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch)
<< getRedeclDiagFromTagKind(NewTag) << isTemplate << Name
<< getRedeclDiagFromTagKind(OldTag);
// FIXME: Note previous location?
}
return true;
}
if (isDefinition) {
// On definitions, check all previous tags and issue a fix-it for each
// one that doesn't match the current tag.
if (Previous->getDefinition()) {
// Don't suggest fix-its for redefinitions.
return true;
}
bool previousMismatch = false;
for (const TagDecl *I : Previous->redecls()) {
if (I->getTagKind() != NewTag) {
// Ignore previous declarations for which the warning was disabled.
if (IsIgnored(I))
continue;
if (!previousMismatch) {
previousMismatch = true;
Diag(NewTagLoc, diag::warn_struct_class_previous_tag_mismatch)
<< getRedeclDiagFromTagKind(NewTag) << isTemplate << Name
<< getRedeclDiagFromTagKind(I->getTagKind());
}
Diag(I->getInnerLocStart(), diag::note_struct_class_suggestion)
<< getRedeclDiagFromTagKind(NewTag)
<< FixItHint::CreateReplacement(I->getInnerLocStart(),
TypeWithKeyword::getTagTypeKindName(NewTag));
}
}
return true;
}
// Identify the prevailing tag kind: this is the kind of the definition (if
// there is a non-ignored definition), or otherwise the kind of the prior
// (non-ignored) declaration.
const TagDecl *PrevDef = Previous->getDefinition();
if (PrevDef && IsIgnored(PrevDef))
PrevDef = nullptr;
const TagDecl *Redecl = PrevDef ? PrevDef : Previous;
if (Redecl->getTagKind() != NewTag) {
Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch)
<< getRedeclDiagFromTagKind(NewTag) << isTemplate << Name
<< getRedeclDiagFromTagKind(OldTag);
Diag(Redecl->getLocation(), diag::note_previous_use);
// If there is a previous definition, suggest a fix-it.
if (PrevDef) {
Diag(NewTagLoc, diag::note_struct_class_suggestion)
<< getRedeclDiagFromTagKind(Redecl->getTagKind())
<< FixItHint::CreateReplacement(SourceRange(NewTagLoc),
TypeWithKeyword::getTagTypeKindName(Redecl->getTagKind()));
}
}
return true;
}
/// Add a minimal nested name specifier fixit hint to allow lookup of a tag name
/// from an outer enclosing namespace or file scope inside a friend declaration.
/// This should provide the commented out code in the following snippet:
/// namespace N {
/// struct X;
/// namespace M {
/// struct Y { friend struct /*N::*/ X; };
/// }
/// }
static FixItHint createFriendTagNNSFixIt(Sema &SemaRef, NamedDecl *ND, Scope *S,
SourceLocation NameLoc) {
// While the decl is in a namespace, do repeated lookup of that name and see
// if we get the same namespace back. If we do not, continue until
// translation unit scope, at which point we have a fully qualified NNS.
SmallVector<IdentifierInfo *, 4> Namespaces;
DeclContext *DC = ND->getDeclContext()->getRedeclContext();
for (; !DC->isTranslationUnit(); DC = DC->getParent()) {
// This tag should be declared in a namespace, which can only be enclosed by
// other namespaces. Bail if there's an anonymous namespace in the chain.
NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(DC);
if (!Namespace || Namespace->isAnonymousNamespace())
return FixItHint();
IdentifierInfo *II = Namespace->getIdentifier();
Namespaces.push_back(II);
NamedDecl *Lookup = SemaRef.LookupSingleName(
S, II, NameLoc, Sema::LookupNestedNameSpecifierName);
if (Lookup == Namespace)
break;
}
// Once we have all the namespaces, reverse them to go outermost first, and
// build an NNS.
SmallString<64> Insertion;
llvm::raw_svector_ostream OS(Insertion);
if (DC->isTranslationUnit())
OS << "::";
std::reverse(Namespaces.begin(), Namespaces.end());
for (auto *II : Namespaces)
OS << II->getName() << "::";
return FixItHint::CreateInsertion(NameLoc, Insertion);
}
/// Determine whether a tag originally declared in context \p OldDC can
/// be redeclared with an unqualified name in \p NewDC (assuming name lookup
/// found a declaration in \p OldDC as a previous decl, perhaps through a
/// using-declaration).
static bool isAcceptableTagRedeclContext(Sema &S, DeclContext *OldDC,
DeclContext *NewDC) {
OldDC = OldDC->getRedeclContext();
NewDC = NewDC->getRedeclContext();
if (OldDC->Equals(NewDC))
return true;
// In MSVC mode, we allow a redeclaration if the contexts are related (either
// encloses the other).
if (S.getLangOpts().MSVCCompat &&
(OldDC->Encloses(NewDC) || NewDC->Encloses(OldDC)))
return true;
return false;
}
DeclResult
Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
CXXScopeSpec &SS, IdentifierInfo *Name, SourceLocation NameLoc,
const ParsedAttributesView &Attrs, AccessSpecifier AS,
SourceLocation ModulePrivateLoc,
MultiTemplateParamsArg TemplateParameterLists, bool &OwnedDecl,
bool &IsDependent, SourceLocation ScopedEnumKWLoc,
bool ScopedEnumUsesClassTag, TypeResult UnderlyingType,
bool IsTypeSpecifier, bool IsTemplateParamOrArg,
OffsetOfKind OOK, SkipBodyInfo *SkipBody) {
// If this is not a definition, it must have a name.
IdentifierInfo *OrigName = Name;
assert((Name != nullptr || TUK == TagUseKind::Definition) &&
"Nameless record must be a definition!");
assert(TemplateParameterLists.size() == 0 || TUK != TagUseKind::Reference);
OwnedDecl = false;
TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
bool ScopedEnum = ScopedEnumKWLoc.isValid();
// FIXME: Check member specializations more carefully.
bool isMemberSpecialization = false;
bool IsInjectedClassName = false;
bool Invalid = false;
// We only need to do this matching if we have template parameters
// or a scope specifier, which also conveniently avoids this work
// for non-C++ cases.
if (TemplateParameterLists.size() > 0 ||
(SS.isNotEmpty() && TUK != TagUseKind::Reference)) {
TemplateParameterList *TemplateParams =
MatchTemplateParametersToScopeSpecifier(
KWLoc, NameLoc, SS, nullptr, TemplateParameterLists,
TUK == TagUseKind::Friend, isMemberSpecialization, Invalid);
// C++23 [dcl.type.elab] p2:
// If an elaborated-type-specifier is the sole constituent of a
// declaration, the declaration is ill-formed unless it is an explicit
// specialization, an explicit instantiation or it has one of the
// following forms: [...]
// C++23 [dcl.enum] p1:
// If the enum-head-name of an opaque-enum-declaration contains a
// nested-name-specifier, the declaration shall be an explicit
// specialization.
//
// FIXME: Class template partial specializations can be forward declared
// per CWG2213, but the resolution failed to allow qualified forward
// declarations. This is almost certainly unintentional, so we allow them.
if (TUK == TagUseKind::Declaration && SS.isNotEmpty() &&
!isMemberSpecialization)
Diag(SS.getBeginLoc(), diag::err_standalone_class_nested_name_specifier)
<< TypeWithKeyword::getTagTypeKindName(Kind) << SS.getRange();
if (TemplateParams) {
if (Kind == TagTypeKind::Enum) {
Diag(KWLoc, diag::err_enum_template);
return true;
}
if (TemplateParams->size() > 0) {
// This is a declaration or definition of a class template (which may
// be a member of another template).
if (Invalid)
return true;
OwnedDecl = false;
DeclResult Result = CheckClassTemplate(
S, TagSpec, TUK, KWLoc, SS, Name, NameLoc, Attrs, TemplateParams,
AS, ModulePrivateLoc,
/*FriendLoc*/ SourceLocation(), TemplateParameterLists.size() - 1,
TemplateParameterLists.data(), SkipBody);
return Result.get();
} else {
// The "template<>" header is extraneous.
Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams)
<< TypeWithKeyword::getTagTypeKindName(Kind) << Name;
isMemberSpecialization = true;
}
}
if (!TemplateParameterLists.empty() && isMemberSpecialization &&
CheckTemplateDeclScope(S, TemplateParameterLists.back()))
return true;
}
if (TUK == TagUseKind::Friend && Kind == TagTypeKind::Enum) {
// C++23 [dcl.type.elab]p4:
// If an elaborated-type-specifier appears with the friend specifier as
// an entire member-declaration, the member-declaration shall have one
// of the following forms:
// friend class-key nested-name-specifier(opt) identifier ;
// friend class-key simple-template-id ;
// friend class-key nested-name-specifier template(opt)
// simple-template-id ;
//
// Since enum is not a class-key, so declarations like "friend enum E;"
// are ill-formed. Although CWG2363 reaffirms that such declarations are
// invalid, most implementations accept so we issue a pedantic warning.
Diag(KWLoc, diag::ext_enum_friend) << FixItHint::CreateRemoval(
ScopedEnum ? SourceRange(KWLoc, ScopedEnumKWLoc) : KWLoc);
assert(ScopedEnum || !ScopedEnumUsesClassTag);
Diag(KWLoc, diag::note_enum_friend)
<< (ScopedEnum + ScopedEnumUsesClassTag);
}
// Figure out the underlying type if this a enum declaration. We need to do
// this early, because it's needed to detect if this is an incompatible
// redeclaration.
llvm::PointerUnion<const Type*, TypeSourceInfo*> EnumUnderlying;
bool IsFixed = !UnderlyingType.isUnset() || ScopedEnum;
if (Kind == TagTypeKind::Enum) {
if (UnderlyingType.isInvalid() || (!UnderlyingType.get() && ScopedEnum)) {
// No underlying type explicitly specified, or we failed to parse the
// type, default to int.
EnumUnderlying = Context.IntTy.getTypePtr();
} else if (UnderlyingType.get()) {
// C++0x 7.2p2: The type-specifier-seq of an enum-base shall name an
// integral type; any cv-qualification is ignored.
// C23 6.7.3.3p5: The underlying type of the enumeration is the
// unqualified, non-atomic version of the type specified by the type
// specifiers in the specifier qualifier list.
TypeSourceInfo *TI = nullptr;
GetTypeFromParser(UnderlyingType.get(), &TI);
EnumUnderlying = TI;
if (CheckEnumUnderlyingType(TI))
// Recover by falling back to int.
EnumUnderlying = Context.IntTy.getTypePtr();
if (DiagnoseUnexpandedParameterPack(TI->getTypeLoc().getBeginLoc(), TI,
UPPC_FixedUnderlyingType))
EnumUnderlying = Context.IntTy.getTypePtr();
// If the underlying type is atomic, we need to adjust the type before
// continuing. This only happens in the case we stored a TypeSourceInfo
// into EnumUnderlying because the other cases are error recovery up to
// this point. But because it's not possible to gin up a TypeSourceInfo
// for a non-atomic type from an atomic one, we'll store into the Type
// field instead. FIXME: it would be nice to have an easy way to get a
// derived TypeSourceInfo which strips qualifiers including the weird
// ones like _Atomic where it forms a different type.
if (TypeSourceInfo *TI = dyn_cast<TypeSourceInfo *>(EnumUnderlying);
TI && TI->getType()->isAtomicType())
EnumUnderlying = TI->getType().getAtomicUnqualifiedType().getTypePtr();
} else if (Context.getTargetInfo().getTriple().isWindowsMSVCEnvironment()) {
// For MSVC ABI compatibility, unfixed enums must use an underlying type
// of 'int'. However, if this is an unfixed forward declaration, don't set
// the underlying type unless the user enables -fms-compatibility. This
// makes unfixed forward declared enums incomplete and is more conforming.
if (TUK == TagUseKind::Definition || getLangOpts().MSVCCompat)
EnumUnderlying = Context.IntTy.getTypePtr();
}
}
DeclContext *SearchDC = CurContext;
DeclContext *DC = CurContext;
bool isStdBadAlloc = false;
bool isStdAlignValT = false;
RedeclarationKind Redecl = forRedeclarationInCurContext();
if (TUK == TagUseKind::Friend || TUK == TagUseKind::Reference)
Redecl = RedeclarationKind::NotForRedeclaration;
/// Create a new tag decl in C/ObjC. Since the ODR-like semantics for ObjC/C
/// implemented asks for structural equivalence checking, the returned decl
/// here is passed back to the parser, allowing the tag body to be parsed.
auto createTagFromNewDecl = [&]() -> TagDecl * {
assert(!getLangOpts().CPlusPlus && "not meant for C++ usage");
// If there is an identifier, use the location of the identifier as the
// location of the decl, otherwise use the location of the struct/union
// keyword.
SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
TagDecl *New = nullptr;
if (Kind == TagTypeKind::Enum) {
New = EnumDecl::Create(Context, SearchDC, KWLoc, Loc, Name, nullptr,
ScopedEnum, ScopedEnumUsesClassTag, IsFixed);
// If this is an undefined enum, bail.
if (TUK != TagUseKind::Definition && !Invalid)
return nullptr;
if (EnumUnderlying) {
EnumDecl *ED = cast<EnumDecl>(New);
if (TypeSourceInfo *TI = dyn_cast<TypeSourceInfo *>(EnumUnderlying))
ED->setIntegerTypeSourceInfo(TI);
else
ED->setIntegerType(QualType(cast<const Type *>(EnumUnderlying), 0));
QualType EnumTy = ED->getIntegerType();
ED->setPromotionType(Context.isPromotableIntegerType(EnumTy)
? Context.getPromotedIntegerType(EnumTy)
: EnumTy);
}
} else { // struct/union
New = RecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name,
nullptr);
}
if (RecordDecl *RD = dyn_cast<RecordDecl>(New)) {
// Add alignment attributes if necessary; these attributes are checked
// when the ASTContext lays out the structure.
//
// It is important for implementing the correct semantics that this
// happen here (in ActOnTag). The #pragma pack stack is
// maintained as a result of parser callbacks which can occur at
// many points during the parsing of a struct declaration (because
// the #pragma tokens are effectively skipped over during the
// parsing of the struct).
if (TUK == TagUseKind::Definition &&
(!SkipBody || !SkipBody->ShouldSkip)) {
if (LangOpts.HLSL)
RD->addAttr(PackedAttr::CreateImplicit(Context));
AddAlignmentAttributesForRecord(RD);
AddMsStructLayoutForRecord(RD);
}
}
New->setLexicalDeclContext(CurContext);
return New;
};
LookupResult Previous(*this, Name, NameLoc, LookupTagName, Redecl);
if (Name && SS.isNotEmpty()) {
// We have a nested-name tag ('struct foo::bar').
// Check for invalid 'foo::'.
if (SS.isInvalid()) {
Name = nullptr;
goto CreateNewDecl;
}
// If this is a friend or a reference to a class in a dependent
// context, don't try to make a decl for it.
if (TUK == TagUseKind::Friend || TUK == TagUseKind::Reference) {
DC = computeDeclContext(SS, false);
if (!DC) {
IsDependent = true;
return true;
}
} else {
DC = computeDeclContext(SS, true);
if (!DC) {
Diag(SS.getRange().getBegin(), diag::err_dependent_nested_name_spec)
<< SS.getRange();
return true;
}
}
if (RequireCompleteDeclContext(SS, DC))
return true;
SearchDC = DC;
// Look-up name inside 'foo::'.
LookupQualifiedName(Previous, DC);
if (Previous.isAmbiguous())
return true;
if (Previous.empty()) {
// Name lookup did not find anything. However, if the
// nested-name-specifier refers to the current instantiation,
// and that current instantiation has any dependent base
// classes, we might find something at instantiation time: treat
// this as a dependent elaborated-type-specifier.
// But this only makes any sense for reference-like lookups.
if (Previous.wasNotFoundInCurrentInstantiation() &&
(TUK == TagUseKind::Reference || TUK == TagUseKind::Friend)) {
IsDependent = true;
return true;
}
// A tag 'foo::bar' must already exist.
Diag(NameLoc, diag::err_not_tag_in_scope)
<< Kind << Name << DC << SS.getRange();
Name = nullptr;
Invalid = true;
goto CreateNewDecl;
}
} else if (Name) {
// C++14 [class.mem]p14:
// If T is the name of a class, then each of the following shall have a
// name different from T:
// -- every member of class T that is itself a type
if (TUK != TagUseKind::Reference && TUK != TagUseKind::Friend &&
DiagnoseClassNameShadow(SearchDC, DeclarationNameInfo(Name, NameLoc)))
return true;
// If this is a named struct, check to see if there was a previous forward
// declaration or definition.
// FIXME: We're looking into outer scopes here, even when we
// shouldn't be. Doing so can result in ambiguities that we
// shouldn't be diagnosing.
LookupName(Previous, S);
// When declaring or defining a tag, ignore ambiguities introduced
// by types using'ed into this scope.
if (Previous.isAmbiguous() &&
(TUK == TagUseKind::Definition || TUK == TagUseKind::Declaration)) {
LookupResult::Filter F = Previous.makeFilter();
while (F.hasNext()) {
NamedDecl *ND = F.next();
if (!ND->getDeclContext()->getRedeclContext()->Equals(
SearchDC->getRedeclContext()))
F.erase();
}
F.done();
}
// C++11 [namespace.memdef]p3:
// If the name in a friend declaration is neither qualified nor
// a template-id and the declaration is a function or an
// elaborated-type-specifier, the lookup to determine whether
// the entity has been previously declared shall not consider
// any scopes outside the innermost enclosing namespace.
//
// MSVC doesn't implement the above rule for types, so a friend tag
// declaration may be a redeclaration of a type declared in an enclosing
// scope. They do implement this rule for friend functions.
//
// Does it matter that this should be by scope instead of by
// semantic context?
if (!Previous.empty() && TUK == TagUseKind::Friend) {
DeclContext *EnclosingNS = SearchDC->getEnclosingNamespaceContext();
LookupResult::Filter F = Previous.makeFilter();
bool FriendSawTagOutsideEnclosingNamespace = false;
while (F.hasNext()) {
NamedDecl *ND = F.next();
DeclContext *DC = ND->getDeclContext()->getRedeclContext();
if (DC->isFileContext() &&
!EnclosingNS->Encloses(ND->getDeclContext())) {
if (getLangOpts().MSVCCompat)
FriendSawTagOutsideEnclosingNamespace = true;
else
F.erase();
}
}
F.done();
// Diagnose this MSVC extension in the easy case where lookup would have
// unambiguously found something outside the enclosing namespace.
if (Previous.isSingleResult() && FriendSawTagOutsideEnclosingNamespace) {
NamedDecl *ND = Previous.getFoundDecl();
Diag(NameLoc, diag::ext_friend_tag_redecl_outside_namespace)
<< createFriendTagNNSFixIt(*this, ND, S, NameLoc);
}
}
// Note: there used to be some attempt at recovery here.
if (Previous.isAmbiguous())
return true;
if (!getLangOpts().CPlusPlus && TUK != TagUseKind::Reference) {
// FIXME: This makes sure that we ignore the contexts associated
// with C structs, unions, and enums when looking for a matching
// tag declaration or definition. See the similar lookup tweak
// in Sema::LookupName; is there a better way to deal with this?
while (isa<RecordDecl, EnumDecl, ObjCContainerDecl>(SearchDC))
SearchDC = SearchDC->getParent();
} else if (getLangOpts().CPlusPlus) {
// Inside ObjCContainer want to keep it as a lexical decl context but go
// past it (most often to TranslationUnit) to find the semantic decl
// context.
while (isa<ObjCContainerDecl>(SearchDC))
SearchDC = SearchDC->getParent();
}
} else if (getLangOpts().CPlusPlus) {
// Don't use ObjCContainerDecl as the semantic decl context for anonymous
// TagDecl the same way as we skip it for named TagDecl.
while (isa<ObjCContainerDecl>(SearchDC))
SearchDC = SearchDC->getParent();
}
if (Previous.isSingleResult() &&
Previous.getFoundDecl()->isTemplateParameter()) {
// Maybe we will complain about the shadowed template parameter.
DiagnoseTemplateParameterShadow(NameLoc, Previous.getFoundDecl());
// Just pretend that we didn't see the previous declaration.
Previous.clear();
}
if (getLangOpts().CPlusPlus && Name && DC && StdNamespace &&
DC->Equals(getStdNamespace())) {
if (Name->isStr("bad_alloc")) {
// This is a declaration of or a reference to "std::bad_alloc".
isStdBadAlloc = true;
// If std::bad_alloc has been implicitly declared (but made invisible to
// name lookup), fill in this implicit declaration as the previous
// declaration, so that the declarations get chained appropriately.
if (Previous.empty() && StdBadAlloc)
Previous.addDecl(getStdBadAlloc());
} else if (Name->isStr("align_val_t")) {
isStdAlignValT = true;
if (Previous.empty() && StdAlignValT)
Previous.addDecl(getStdAlignValT());
}
}
// If we didn't find a previous declaration, and this is a reference
// (or friend reference), move to the correct scope. In C++, we
// also need to do a redeclaration lookup there, just in case
// there's a shadow friend decl.
if (Name && Previous.empty() &&
(TUK == TagUseKind::Reference || TUK == TagUseKind::Friend ||
IsTemplateParamOrArg)) {
if (Invalid) goto CreateNewDecl;
assert(SS.isEmpty());
if (TUK == TagUseKind::Reference || IsTemplateParamOrArg) {
// C++ [basic.scope.pdecl]p5:
// -- for an elaborated-type-specifier of the form
//
// class-key identifier
//
// if the elaborated-type-specifier is used in the
// decl-specifier-seq or parameter-declaration-clause of a
// function defined in namespace scope, the identifier is
// declared as a class-name in the namespace that contains
// the declaration; otherwise, except as a friend
// declaration, the identifier is declared in the smallest
// non-class, non-function-prototype scope that contains the
// declaration.
//
// C99 6.7.2.3p8 has a similar (but not identical!) provision for
// C structs and unions.
//
// It is an error in C++ to declare (rather than define) an enum
// type, including via an elaborated type specifier. We'll
// diagnose that later; for now, declare the enum in the same
// scope as we would have picked for any other tag type.
//
// GNU C also supports this behavior as part of its incomplete
// enum types extension, while GNU C++ does not.
//
// Find the context where we'll be declaring the tag.
// FIXME: We would like to maintain the current DeclContext as the
// lexical context,
SearchDC = getTagInjectionContext(SearchDC);
// Find the scope where we'll be declaring the tag.
S = getTagInjectionScope(S, getLangOpts());
} else {
assert(TUK == TagUseKind::Friend);
CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(SearchDC);
// C++ [namespace.memdef]p3:
// If a friend declaration in a non-local class first declares a
// class or function, the friend class or function is a member of
// the innermost enclosing namespace.
SearchDC = RD->isLocalClass() ? RD->isLocalClass()
: SearchDC->getEnclosingNamespaceContext();
}
// In C++, we need to do a redeclaration lookup to properly
// diagnose some problems.
// FIXME: redeclaration lookup is also used (with and without C++) to find a
// hidden declaration so that we don't get ambiguity errors when using a
// type declared by an elaborated-type-specifier. In C that is not correct
// and we should instead merge compatible types found by lookup.
if (getLangOpts().CPlusPlus) {
// FIXME: This can perform qualified lookups into function contexts,
// which are meaningless.
Previous.setRedeclarationKind(forRedeclarationInCurContext());
LookupQualifiedName(Previous, SearchDC);
} else {
Previous.setRedeclarationKind(forRedeclarationInCurContext());
LookupName(Previous, S);
}
}
// If we have a known previous declaration to use, then use it.
if (Previous.empty() && SkipBody && SkipBody->Previous)
Previous.addDecl(SkipBody->Previous);
if (!Previous.empty()) {
NamedDecl *PrevDecl = Previous.getFoundDecl();
NamedDecl *DirectPrevDecl = Previous.getRepresentativeDecl();
// It's okay to have a tag decl in the same scope as a typedef
// which hides a tag decl in the same scope. Finding this
// with a redeclaration lookup can only actually happen in C++.
//
// This is also okay for elaborated-type-specifiers, which is
// technically forbidden by the current standard but which is
// okay according to the likely resolution of an open issue;
// see http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#407
if (getLangOpts().CPlusPlus) {
if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(PrevDecl)) {
if (TagDecl *Tag = TD->getUnderlyingType()->getAsTagDecl()) {
if (Tag->getDeclName() == Name &&
Tag->getDeclContext()->getRedeclContext()
->Equals(TD->getDeclContext()->getRedeclContext())) {
PrevDecl = Tag;
Previous.clear();
Previous.addDecl(Tag);
Previous.resolveKind();
}
}
} else if (auto *RD = dyn_cast<CXXRecordDecl>(PrevDecl);
TUK == TagUseKind::Reference && RD &&
RD->isInjectedClassName()) {
// If lookup found the injected class name, the previous declaration is
// the class being injected into.
PrevDecl = cast<TagDecl>(RD->getDeclContext());
Previous.clear();
Previous.addDecl(PrevDecl);
Previous.resolveKind();
IsInjectedClassName = true;
}
}
// If this is a redeclaration of a using shadow declaration, it must
// declare a tag in the same context. In MSVC mode, we allow a
// redefinition if either context is within the other.
if (auto *Shadow = dyn_cast<UsingShadowDecl>(DirectPrevDecl)) {
auto *OldTag = dyn_cast<TagDecl>(PrevDecl);
if (SS.isEmpty() && TUK != TagUseKind::Reference &&
TUK != TagUseKind::Friend &&
isDeclInScope(Shadow, SearchDC, S, isMemberSpecialization) &&
!(OldTag && isAcceptableTagRedeclContext(
*this, OldTag->getDeclContext(), SearchDC))) {
Diag(KWLoc, diag::err_using_decl_conflict_reverse);
Diag(Shadow->getTargetDecl()->getLocation(),
diag::note_using_decl_target);
Diag(Shadow->getIntroducer()->getLocation(), diag::note_using_decl)
<< 0;
// Recover by ignoring the old declaration.
Previous.clear();
goto CreateNewDecl;
}
}
if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) {
// If this is a use of a previous tag, or if the tag is already declared
// in the same scope (so that the definition/declaration completes or
// rementions the tag), reuse the decl.
if (TUK == TagUseKind::Reference || TUK == TagUseKind::Friend ||
isDeclInScope(DirectPrevDecl, SearchDC, S,
SS.isNotEmpty() || isMemberSpecialization)) {
// Make sure that this wasn't declared as an enum and now used as a
// struct or something similar.
if (!isAcceptableTagRedeclaration(PrevTagDecl, Kind,
TUK == TagUseKind::Definition, KWLoc,
Name)) {
bool SafeToContinue =
(PrevTagDecl->getTagKind() != TagTypeKind::Enum &&
Kind != TagTypeKind::Enum);
if (SafeToContinue)
Diag(KWLoc, diag::err_use_with_wrong_tag)
<< Name
<< FixItHint::CreateReplacement(SourceRange(KWLoc),
PrevTagDecl->getKindName());
else
Diag(KWLoc, diag::err_use_with_wrong_tag) << Name;
Diag(PrevTagDecl->getLocation(), diag::note_previous_use);
if (SafeToContinue)
Kind = PrevTagDecl->getTagKind();
else {
// Recover by making this an anonymous redefinition.
Name = nullptr;
Previous.clear();
Invalid = true;
}
}
if (Kind == TagTypeKind::Enum &&
PrevTagDecl->getTagKind() == TagTypeKind::Enum) {
const EnumDecl *PrevEnum = cast<EnumDecl>(PrevTagDecl);
if (TUK == TagUseKind::Reference || TUK == TagUseKind::Friend)
return PrevTagDecl;
QualType EnumUnderlyingTy;
if (TypeSourceInfo *TI =
dyn_cast_if_present<TypeSourceInfo *>(EnumUnderlying))
EnumUnderlyingTy = TI->getType().getUnqualifiedType();
else if (const Type *T =
dyn_cast_if_present<const Type *>(EnumUnderlying))
EnumUnderlyingTy = QualType(T, 0);
// All conflicts with previous declarations are recovered by
// returning the previous declaration, unless this is a definition,
// in which case we want the caller to bail out.
if (CheckEnumRedeclaration(NameLoc.isValid() ? NameLoc : KWLoc,
ScopedEnum, EnumUnderlyingTy,
IsFixed, PrevEnum))
return TUK == TagUseKind::Declaration ? PrevTagDecl : nullptr;
}
// C++11 [class.mem]p1:
// A member shall not be declared twice in the member-specification,
// except that a nested class or member class template can be declared
// and then later defined.
if (TUK == TagUseKind::Declaration && PrevDecl->isCXXClassMember() &&
S->isDeclScope(PrevDecl)) {
Diag(NameLoc, diag::ext_member_redeclared);
Diag(PrevTagDecl->getLocation(), diag::note_previous_declaration);
}
if (!Invalid) {
// If this is a use, just return the declaration we found, unless
// we have attributes.
if (TUK == TagUseKind::Reference || TUK == TagUseKind::Friend) {
if (!Attrs.empty()) {
// FIXME: Diagnose these attributes. For now, we create a new
// declaration to hold them.
} else if (TUK == TagUseKind::Reference &&
(PrevTagDecl->getFriendObjectKind() ==
Decl::FOK_Undeclared ||
PrevDecl->getOwningModule() != getCurrentModule()) &&
SS.isEmpty()) {
// This declaration is a reference to an existing entity, but
// has different visibility from that entity: it either makes
// a friend visible or it makes a type visible in a new module.
// In either case, create a new declaration. We only do this if
// the declaration would have meant the same thing if no prior
// declaration were found, that is, if it was found in the same
// scope where we would have injected a declaration.
if (!getTagInjectionContext(CurContext)->getRedeclContext()
->Equals(PrevDecl->getDeclContext()->getRedeclContext()))
return PrevTagDecl;
// This is in the injected scope, create a new declaration in
// that scope.
S = getTagInjectionScope(S, getLangOpts());
} else {
return PrevTagDecl;
}
}
// Diagnose attempts to redefine a tag.
if (TUK == TagUseKind::Definition) {
if (TagDecl *Def = PrevTagDecl->getDefinition()) {
// If the type is currently being defined, complain
// about a nested redefinition.
if (Def->isBeingDefined()) {
Diag(NameLoc, diag::err_nested_redefinition) << Name;
Diag(PrevTagDecl->getLocation(),
diag::note_previous_definition);
Name = nullptr;
Previous.clear();
Invalid = true;
} else {
// If we're defining a specialization and the previous
// definition is from an implicit instantiation, don't emit an
// error here; we'll catch this in the general case below.
bool IsExplicitSpecializationAfterInstantiation = false;
if (isMemberSpecialization) {
if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Def))
IsExplicitSpecializationAfterInstantiation =
RD->getTemplateSpecializationKind() !=
TSK_ExplicitSpecialization;
else if (EnumDecl *ED = dyn_cast<EnumDecl>(Def))
IsExplicitSpecializationAfterInstantiation =
ED->getTemplateSpecializationKind() !=
TSK_ExplicitSpecialization;
}
// Note that clang allows ODR-like semantics for ObjC/C, i.e.,
// do not keep more that one definition around (merge them).
// However, ensure the decl passes the structural compatibility
// check in C11 6.2.7/1 (or 6.1.2.6/1 in C89).
NamedDecl *Hidden = nullptr;
bool HiddenDefVisible = false;
if (SkipBody &&
(isRedefinitionAllowedFor(Def, &Hidden, HiddenDefVisible) ||
getLangOpts().C23)) {
// There is a definition of this tag, but it is not visible.
// We explicitly make use of C++'s one definition rule here,
// and assume that this definition is identical to the hidden
// one we already have. Make the existing definition visible
// and use it in place of this one.
if (!getLangOpts().CPlusPlus) {
// Postpone making the old definition visible until after we
// complete parsing the new one and do the structural
// comparison.
SkipBody->CheckSameAsPrevious = true;
SkipBody->New = createTagFromNewDecl();
SkipBody->Previous = Def;
ProcessDeclAttributeList(S, SkipBody->New, Attrs);
return Def;
}
SkipBody->ShouldSkip = true;
SkipBody->Previous = Def;
if (!HiddenDefVisible && Hidden)
makeMergedDefinitionVisible(Hidden);
// Carry on and handle it like a normal definition. We'll
// skip starting the definition later.
} else if (!IsExplicitSpecializationAfterInstantiation) {
// A redeclaration in function prototype scope in C isn't
// visible elsewhere, so merely issue a warning.
if (!getLangOpts().CPlusPlus &&
S->containedInPrototypeScope())
Diag(NameLoc, diag::warn_redefinition_in_param_list)
<< Name;
else
Diag(NameLoc, diag::err_redefinition) << Name;
notePreviousDefinition(Def,
NameLoc.isValid() ? NameLoc : KWLoc);
// If this is a redefinition, recover by making this
// struct be anonymous, which will make any later
// references get the previous definition.
Name = nullptr;
Previous.clear();
Invalid = true;
}
}
}
// Okay, this is definition of a previously declared or referenced
// tag. We're going to create a new Decl for it.
}
// Okay, we're going to make a redeclaration. If this is some kind
// of reference, make sure we build the redeclaration in the same DC
// as the original, and ignore the current access specifier.
if (TUK == TagUseKind::Friend || TUK == TagUseKind::Reference) {
SearchDC = PrevTagDecl->getDeclContext();
AS = AS_none;
}
}
// If we get here we have (another) forward declaration or we
// have a definition. Just create a new decl.
} else {
// If we get here, this is a definition of a new tag type in a nested
// scope, e.g. "struct foo; void bar() { struct foo; }", just create a
// new decl/type. We set PrevDecl to NULL so that the entities
// have distinct types.
Previous.clear();
}
// If we get here, we're going to create a new Decl. If PrevDecl
// is non-NULL, it's a definition of the tag declared by
// PrevDecl. If it's NULL, we have a new definition.
// Otherwise, PrevDecl is not a tag, but was found with tag
// lookup. This is only actually possible in C++, where a few
// things like templates still live in the tag namespace.
} else {
// Use a better diagnostic if an elaborated-type-specifier
// found the wrong kind of type on the first
// (non-redeclaration) lookup.
if ((TUK == TagUseKind::Reference || TUK == TagUseKind::Friend) &&
!Previous.isForRedeclaration()) {
NonTagKind NTK = getNonTagTypeDeclKind(PrevDecl, Kind);
Diag(NameLoc, diag::err_tag_reference_non_tag)
<< PrevDecl << NTK << Kind;
Diag(PrevDecl->getLocation(), diag::note_declared_at);
Invalid = true;
// Otherwise, only diagnose if the declaration is in scope.
} else if (!isDeclInScope(DirectPrevDecl, SearchDC, S,
SS.isNotEmpty() || isMemberSpecialization)) {
// do nothing
// Diagnose implicit declarations introduced by elaborated types.
} else if (TUK == TagUseKind::Reference || TUK == TagUseKind::Friend) {
NonTagKind NTK = getNonTagTypeDeclKind(PrevDecl, Kind);
Diag(NameLoc, diag::err_tag_reference_conflict) << NTK;
Diag(PrevDecl->getLocation(), diag::note_previous_decl) << PrevDecl;
Invalid = true;
// Otherwise it's a declaration. Call out a particularly common
// case here.
} else if (TypedefNameDecl *TND = dyn_cast<TypedefNameDecl>(PrevDecl)) {
unsigned Kind = 0;
if (isa<TypeAliasDecl>(PrevDecl)) Kind = 1;
Diag(NameLoc, diag::err_tag_definition_of_typedef)
<< Name << Kind << TND->getUnderlyingType();
Diag(PrevDecl->getLocation(), diag::note_previous_decl) << PrevDecl;
Invalid = true;
// Otherwise, diagnose.
} else {
// The tag name clashes with something else in the target scope,
// issue an error and recover by making this tag be anonymous.
Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
notePreviousDefinition(PrevDecl, NameLoc);
Name = nullptr;
Invalid = true;
}
// The existing declaration isn't relevant to us; we're in a
// new scope, so clear out the previous declaration.
Previous.clear();
}
}
CreateNewDecl:
TagDecl *PrevDecl = nullptr;
if (Previous.isSingleResult())
PrevDecl = cast<TagDecl>(Previous.getFoundDecl());
// If there is an identifier, use the location of the identifier as the
// location of the decl, otherwise use the location of the struct/union
// keyword.
SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
// Otherwise, create a new declaration. If there is a previous
// declaration of the same entity, the two will be linked via
// PrevDecl.
TagDecl *New;
if (Kind == TagTypeKind::Enum) {
// FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
// enum X { A, B, C } D; D should chain to X.
New = EnumDecl::Create(Context, SearchDC, KWLoc, Loc, Name,
cast_or_null<EnumDecl>(PrevDecl), ScopedEnum,
ScopedEnumUsesClassTag, IsFixed);
if (isStdAlignValT && (!StdAlignValT || getStdAlignValT()->isImplicit()))
StdAlignValT = cast<EnumDecl>(New);
// If this is an undefined enum, warn.
if (TUK != TagUseKind::Definition && !Invalid) {
TagDecl *Def;
if (IsFixed && cast<EnumDecl>(New)->isFixed()) {
// C++0x: 7.2p2: opaque-enum-declaration.
// Conflicts are diagnosed above. Do nothing.
}
else if (PrevDecl && (Def = cast<EnumDecl>(PrevDecl)->getDefinition())) {
Diag(Loc, diag::ext_forward_ref_enum_def)
<< New;
Diag(Def->getLocation(), diag::note_previous_definition);
} else {
unsigned DiagID = diag::ext_forward_ref_enum;
if (getLangOpts().MSVCCompat)
DiagID = diag::ext_ms_forward_ref_enum;
else if (getLangOpts().CPlusPlus)
DiagID = diag::err_forward_ref_enum;
Diag(Loc, DiagID);
}
}
if (EnumUnderlying) {
EnumDecl *ED = cast<EnumDecl>(New);
if (TypeSourceInfo *TI = dyn_cast<TypeSourceInfo *>(EnumUnderlying))
ED->setIntegerTypeSourceInfo(TI);
else
ED->setIntegerType(QualType(cast<const Type *>(EnumUnderlying), 0));
QualType EnumTy = ED->getIntegerType();
ED->setPromotionType(Context.isPromotableIntegerType(EnumTy)
? Context.getPromotedIntegerType(EnumTy)
: EnumTy);
assert(ED->isComplete() && "enum with type should be complete");
}
} else {
// struct/union/class
// FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
// struct X { int A; } D; D should chain to X.
if (getLangOpts().CPlusPlus) {
// FIXME: Look for a way to use RecordDecl for simple structs.
New = CXXRecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name,
cast_or_null<CXXRecordDecl>(PrevDecl));
if (isStdBadAlloc && (!StdBadAlloc || getStdBadAlloc()->isImplicit()))
StdBadAlloc = cast<CXXRecordDecl>(New);
} else
New = RecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name,
cast_or_null<RecordDecl>(PrevDecl));
}
// Only C23 and later allow defining new types in 'offsetof()'.
if (OOK != OffsetOfKind::Outside && TUK == TagUseKind::Definition &&
!getLangOpts().CPlusPlus && !getLangOpts().C23)
Diag(New->getLocation(), diag::ext_type_defined_in_offsetof)
<< (OOK == OffsetOfKind::Macro) << New->getSourceRange();
// C++11 [dcl.type]p3:
// A type-specifier-seq shall not define a class or enumeration [...].
if (!Invalid && getLangOpts().CPlusPlus &&
(IsTypeSpecifier || IsTemplateParamOrArg) &&
TUK == TagUseKind::Definition) {
Diag(New->getLocation(), diag::err_type_defined_in_type_specifier)
<< Context.getCanonicalTagType(New);
Invalid = true;
}
if (!Invalid && getLangOpts().CPlusPlus && TUK == TagUseKind::Definition &&
DC->getDeclKind() == Decl::Enum) {
Diag(New->getLocation(), diag::err_type_defined_in_enum)
<< Context.getCanonicalTagType(New);
Invalid = true;
}
// Maybe add qualifier info.
if (SS.isNotEmpty()) {
if (SS.isSet()) {
// If this is either a declaration or a definition, check the
// nested-name-specifier against the current context.
if ((TUK == TagUseKind::Definition || TUK == TagUseKind::Declaration) &&
diagnoseQualifiedDeclaration(SS, DC, OrigName, Loc,
/*TemplateId=*/nullptr,
isMemberSpecialization))
Invalid = true;
New->setQualifierInfo(SS.getWithLocInContext(Context));
if (TemplateParameterLists.size() > 0) {
New->setTemplateParameterListsInfo(Context, TemplateParameterLists);
}
}
else
Invalid = true;
}
if (RecordDecl *RD = dyn_cast<RecordDecl>(New)) {
// Add alignment attributes if necessary; these attributes are checked when
// the ASTContext lays out the structure.
//
// It is important for implementing the correct semantics that this
// happen here (in ActOnTag). The #pragma pack stack is
// maintained as a result of parser callbacks which can occur at
// many points during the parsing of a struct declaration (because
// the #pragma tokens are effectively skipped over during the
// parsing of the struct).
if (TUK == TagUseKind::Definition && (!SkipBody || !SkipBody->ShouldSkip)) {
if (LangOpts.HLSL)
RD->addAttr(PackedAttr::CreateImplicit(Context));
AddAlignmentAttributesForRecord(RD);
AddMsStructLayoutForRecord(RD);
}
}
if (ModulePrivateLoc.isValid()) {
if (isMemberSpecialization)
Diag(New->getLocation(), diag::err_module_private_specialization)
<< 2
<< FixItHint::CreateRemoval(ModulePrivateLoc);
// __module_private__ does not apply to local classes. However, we only
// diagnose this as an error when the declaration specifiers are
// freestanding. Here, we just ignore the __module_private__.
else if (!SearchDC->isFunctionOrMethod())
New->setModulePrivate();
}
// If this is a specialization of a member class (of a class template),
// check the specialization.
if (isMemberSpecialization && CheckMemberSpecialization(New, Previous))
Invalid = true;
// If we're declaring or defining a tag in function prototype scope in C,
// note that this type can only be used within the function and add it to
// the list of decls to inject into the function definition scope. However,
// in C23 and later, while the type is only visible within the function, the
// function can be called with a compatible type defined in the same TU, so
// we silence the diagnostic in C23 and up. This matches the behavior of GCC.
if ((Name || Kind == TagTypeKind::Enum) &&
getNonFieldDeclScope(S)->isFunctionPrototypeScope()) {
if (getLangOpts().CPlusPlus) {
// C++ [dcl.fct]p6:
// Types shall not be defined in return or parameter types.
if (TUK == TagUseKind::Definition && !IsTypeSpecifier) {
Diag(Loc, diag::err_type_defined_in_param_type)
<< Name;
Invalid = true;
}
if (TUK == TagUseKind::Declaration)
Invalid = true;
} else if (!PrevDecl) {
// In C23 mode, if the declaration is complete, we do not want to
// diagnose.
if (!getLangOpts().C23 || TUK != TagUseKind::Definition)
Diag(Loc, diag::warn_decl_in_param_list)
<< Context.getCanonicalTagType(New);
}
}
if (Invalid)
New->setInvalidDecl();
// Set the lexical context. If the tag has a C++ scope specifier, the
// lexical context will be different from the semantic context.
New->setLexicalDeclContext(CurContext);
// Mark this as a friend decl if applicable.
// In Microsoft mode, a friend declaration also acts as a forward
// declaration so we always pass true to setObjectOfFriendDecl to make
// the tag name visible.
if (TUK == TagUseKind::Friend)
New->setObjectOfFriendDecl(getLangOpts().MSVCCompat);
// Set the access specifier.
if (!Invalid && SearchDC->isRecord())
SetMemberAccessSpecifier(New, PrevDecl, AS);
if (PrevDecl)
CheckRedeclarationInModule(New, PrevDecl);
if (TUK == TagUseKind::Definition) {
if (!SkipBody || !SkipBody->ShouldSkip) {
New->startDefinition();
} else {
New->setCompleteDefinition();
New->demoteThisDefinitionToDeclaration();
}
}
ProcessDeclAttributeList(S, New, Attrs);
AddPragmaAttributes(S, New);
// If this has an identifier, add it to the scope stack.
if (TUK == TagUseKind::Friend || IsInjectedClassName) {
// We might be replacing an existing declaration in the lookup tables;
// if so, borrow its access specifier.
if (PrevDecl)
New->setAccess(PrevDecl->getAccess());
DeclContext *DC = New->getDeclContext()->getRedeclContext();
DC->makeDeclVisibleInContext(New);
if (Name) // can be null along some error paths
if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
PushOnScopeChains(New, EnclosingScope, /* AddToContext = */ false);
} else if (Name) {
S = getNonFieldDeclScope(S);
PushOnScopeChains(New, S, true);
} else {
CurContext->addDecl(New);
}
// If this is the C FILE type, notify the AST context.
if (IdentifierInfo *II = New->getIdentifier())
if (!New->isInvalidDecl() &&
New->getDeclContext()->getRedeclContext()->isTranslationUnit() &&
II->isStr("FILE"))
Context.setFILEDecl(New);
if (PrevDecl)
mergeDeclAttributes(New, PrevDecl);
if (auto *CXXRD = dyn_cast<CXXRecordDecl>(New)) {
inferGslOwnerPointerAttribute(CXXRD);
inferNullableClassAttribute(CXXRD);
}
// If there's a #pragma GCC visibility in scope, set the visibility of this
// record.
AddPushedVisibilityAttribute(New);
// If this is not a definition, process API notes for it now.
if (TUK != TagUseKind::Definition)
ProcessAPINotes(New);
if (isMemberSpecialization && !New->isInvalidDecl())
CompleteMemberSpecialization(New, Previous);
OwnedDecl = true;
// In C++, don't return an invalid declaration. We can't recover well from
// the cases where we make the type anonymous.
if (Invalid && getLangOpts().CPlusPlus) {
if (New->isBeingDefined())
if (auto RD = dyn_cast<RecordDecl>(New))
RD->completeDefinition();
return true;
} else if (SkipBody && SkipBody->ShouldSkip) {
return SkipBody->Previous;
} else {
return New;
}
}
void Sema::ActOnTagStartDefinition(Scope *S, Decl *TagD) {
AdjustDeclIfTemplate(TagD);
TagDecl *Tag = cast<TagDecl>(TagD);
// Enter the tag context.
PushDeclContext(S, Tag);
ActOnDocumentableDecl(TagD);
// If there's a #pragma GCC visibility in scope, set the visibility of this
// record.
AddPushedVisibilityAttribute(Tag);
}
bool Sema::ActOnDuplicateDefinition(Scope *S, Decl *Prev,
SkipBodyInfo &SkipBody) {
if (!hasStructuralCompatLayout(Prev, SkipBody.New))
return false;
// Make the previous decl visible.
makeMergedDefinitionVisible(SkipBody.Previous);
CleanupMergedEnum(S, SkipBody.New);
return true;
}
void Sema::ActOnStartCXXMemberDeclarations(
Scope *S, Decl *TagD, SourceLocation FinalLoc, bool IsFinalSpelledSealed,
bool IsAbstract, SourceLocation TriviallyRelocatable,
SourceLocation Replaceable, SourceLocation LBraceLoc) {
AdjustDeclIfTemplate(TagD);
CXXRecordDecl *Record = cast<CXXRecordDecl>(TagD);
FieldCollector->StartClass();
if (!Record->getIdentifier())
return;
if (IsAbstract)
Record->markAbstract();
if (FinalLoc.isValid()) {
Record->addAttr(FinalAttr::Create(Context, FinalLoc,
IsFinalSpelledSealed
? FinalAttr::Keyword_sealed
: FinalAttr::Keyword_final));
}
if (TriviallyRelocatable.isValid())
Record->addAttr(
TriviallyRelocatableAttr::Create(Context, TriviallyRelocatable));
if (Replaceable.isValid())
Record->addAttr(ReplaceableAttr::Create(Context, Replaceable));
// C++ [class]p2:
// [...] The class-name is also inserted into the scope of the
// class itself; this is known as the injected-class-name. For
// purposes of access checking, the injected-class-name is treated
// as if it were a public member name.
CXXRecordDecl *InjectedClassName = CXXRecordDecl::Create(
Context, Record->getTagKind(), CurContext, Record->getBeginLoc(),
Record->getLocation(), Record->getIdentifier());
InjectedClassName->setImplicit();
InjectedClassName->setAccess(AS_public);
if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate())
InjectedClassName->setDescribedClassTemplate(Template);
PushOnScopeChains(InjectedClassName, S);
assert(InjectedClassName->isInjectedClassName() &&
"Broken injected-class-name");
}
void Sema::ActOnTagFinishDefinition(Scope *S, Decl *TagD,
SourceRange BraceRange) {
AdjustDeclIfTemplate(TagD);
TagDecl *Tag = cast<TagDecl>(TagD);
Tag->setBraceRange(BraceRange);
// Make sure we "complete" the definition even it is invalid.
if (Tag->isBeingDefined()) {
assert(Tag->isInvalidDecl() && "We should already have completed it");
if (RecordDecl *RD = dyn_cast<RecordDecl>(Tag))
RD->completeDefinition();
}
if (auto *RD = dyn_cast<CXXRecordDecl>(Tag)) {
FieldCollector->FinishClass();
if (RD->hasAttr<SYCLSpecialClassAttr>()) {
auto *Def = RD->getDefinition();
assert(Def && "The record is expected to have a completed definition");
unsigned NumInitMethods = 0;
for (auto *Method : Def->methods()) {
if (!Method->getIdentifier())
continue;
if (Method->getName() == "__init")
NumInitMethods++;
}
if (NumInitMethods > 1 || !Def->hasInitMethod())
Diag(RD->getLocation(), diag::err_sycl_special_type_num_init_method);
}
// If we're defining a dynamic class in a module interface unit, we always
// need to produce the vtable for it, even if the vtable is not used in the
// current TU.
//
// The case where the current class is not dynamic is handled in
// MarkVTableUsed.
if (getCurrentModule() && getCurrentModule()->isInterfaceOrPartition())
MarkVTableUsed(RD->getLocation(), RD, /*DefinitionRequired=*/true);
}
// Exit this scope of this tag's definition.
PopDeclContext();
if (getCurLexicalContext()->isObjCContainer() &&
Tag->getDeclContext()->isFileContext())
Tag->setTopLevelDeclInObjCContainer();
// Notify the consumer that we've defined a tag.
if (!Tag->isInvalidDecl())
Consumer.HandleTagDeclDefinition(Tag);
// Clangs implementation of #pragma align(packed) differs in bitfield layout
// from XLs and instead matches the XL #pragma pack(1) behavior.
if (Context.getTargetInfo().getTriple().isOSAIX() &&
AlignPackStack.hasValue()) {
AlignPackInfo APInfo = AlignPackStack.CurrentValue;
// Only diagnose #pragma align(packed).
if (!APInfo.IsAlignAttr() || APInfo.getAlignMode() != AlignPackInfo::Packed)
return;
const RecordDecl *RD = dyn_cast<RecordDecl>(Tag);
if (!RD)
return;
// Only warn if there is at least 1 bitfield member.
if (llvm::any_of(RD->fields(),
[](const FieldDecl *FD) { return FD->isBitField(); }))
Diag(BraceRange.getBegin(), diag::warn_pragma_align_not_xl_compatible);
}
}
void Sema::ActOnTagDefinitionError(Scope *S, Decl *TagD) {
AdjustDeclIfTemplate(TagD);
TagDecl *Tag = cast<TagDecl>(TagD);
Tag->setInvalidDecl();
// Make sure we "complete" the definition even it is invalid.
if (Tag->isBeingDefined()) {
if (RecordDecl *RD = dyn_cast<RecordDecl>(Tag))
RD->completeDefinition();
}
// We're undoing ActOnTagStartDefinition here, not
// ActOnStartCXXMemberDeclarations, so we don't have to mess with
// the FieldCollector.
PopDeclContext();
}
// Note that FieldName may be null for anonymous bitfields.
ExprResult Sema::VerifyBitField(SourceLocation FieldLoc,
const IdentifierInfo *FieldName,
QualType FieldTy, bool IsMsStruct,
Expr *BitWidth) {
assert(BitWidth);
if (BitWidth->containsErrors())
return ExprError();
// C99 6.7.2.1p4 - verify the field type.
// C++ 9.6p3: A bit-field shall have integral or enumeration type.
if (!FieldTy->isDependentType() && !FieldTy->isIntegralOrEnumerationType()) {
// Handle incomplete and sizeless types with a specific error.
if (RequireCompleteSizedType(FieldLoc, FieldTy,
diag::err_field_incomplete_or_sizeless))
return ExprError();
if (FieldName)
return Diag(FieldLoc, diag::err_not_integral_type_bitfield)
<< FieldName << FieldTy << BitWidth->getSourceRange();
return Diag(FieldLoc, diag::err_not_integral_type_anon_bitfield)
<< FieldTy << BitWidth->getSourceRange();
} else if (DiagnoseUnexpandedParameterPack(BitWidth, UPPC_BitFieldWidth))
return ExprError();
// If the bit-width is type- or value-dependent, don't try to check
// it now.
if (BitWidth->isValueDependent() || BitWidth->isTypeDependent())
return BitWidth;
llvm::APSInt Value;
ExprResult ICE =
VerifyIntegerConstantExpression(BitWidth, &Value, AllowFoldKind::Allow);
if (ICE.isInvalid())
return ICE;
BitWidth = ICE.get();
// Zero-width bitfield is ok for anonymous field.
if (Value == 0 && FieldName)
return Diag(FieldLoc, diag::err_bitfield_has_zero_width)
<< FieldName << BitWidth->getSourceRange();
if (Value.isSigned() && Value.isNegative()) {
if (FieldName)
return Diag(FieldLoc, diag::err_bitfield_has_negative_width)
<< FieldName << toString(Value, 10);
return Diag(FieldLoc, diag::err_anon_bitfield_has_negative_width)
<< toString(Value, 10);
}
// The size of the bit-field must not exceed our maximum permitted object
// size.
if (Value.getActiveBits() > ConstantArrayType::getMaxSizeBits(Context)) {
return Diag(FieldLoc, diag::err_bitfield_too_wide)
<< !FieldName << FieldName << toString(Value, 10);
}
if (!FieldTy->isDependentType()) {
uint64_t TypeStorageSize = Context.getTypeSize(FieldTy);
uint64_t TypeWidth = Context.getIntWidth(FieldTy);
bool BitfieldIsOverwide = Value.ugt(TypeWidth);
// Over-wide bitfields are an error in C or when using the MSVC bitfield
// ABI.
bool CStdConstraintViolation =
BitfieldIsOverwide && !getLangOpts().CPlusPlus;
bool MSBitfieldViolation =
Value.ugt(TypeStorageSize) &&
(IsMsStruct || Context.getTargetInfo().getCXXABI().isMicrosoft());
if (CStdConstraintViolation || MSBitfieldViolation) {
unsigned DiagWidth =
CStdConstraintViolation ? TypeWidth : TypeStorageSize;
return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_width)
<< (bool)FieldName << FieldName << toString(Value, 10)
<< !CStdConstraintViolation << DiagWidth;
}
// Warn on types where the user might conceivably expect to get all
// specified bits as value bits: that's all integral types other than
// 'bool'.
if (BitfieldIsOverwide && !FieldTy->isBooleanType() && FieldName) {
Diag(FieldLoc, diag::warn_bitfield_width_exceeds_type_width)
<< FieldName << toString(Value, 10)
<< (unsigned)TypeWidth;
}
}
if (isa<ConstantExpr>(BitWidth))
return BitWidth;
return ConstantExpr::Create(getASTContext(), BitWidth, APValue{Value});
}
Decl *Sema::ActOnField(Scope *S, Decl *TagD, SourceLocation DeclStart,
Declarator &D, Expr *BitfieldWidth) {
FieldDecl *Res = HandleField(S, cast_if_present<RecordDecl>(TagD), DeclStart,
D, BitfieldWidth,
/*InitStyle=*/ICIS_NoInit, AS_public);
return Res;
}
FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record,
SourceLocation DeclStart,
Declarator &D, Expr *BitWidth,
InClassInitStyle InitStyle,
AccessSpecifier AS) {
if (D.isDecompositionDeclarator()) {
const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator();
Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
<< Decomp.getSourceRange();
return nullptr;
}
const IdentifierInfo *II = D.getIdentifier();
SourceLocation Loc = DeclStart;
if (II) Loc = D.getIdentifierLoc();
TypeSourceInfo *TInfo = GetTypeForDeclarator(D);
QualType T = TInfo->getType();
if (getLangOpts().CPlusPlus) {
CheckExtraCXXDefaultArguments(D);
if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
UPPC_DataMemberType)) {
D.setInvalidType();
T = Context.IntTy;
TInfo = Context.getTrivialTypeSourceInfo(T, Loc);
}
}
DiagnoseFunctionSpecifiers(D.getDeclSpec());
if (D.getDeclSpec().isInlineSpecified())
Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
<< getLangOpts().CPlusPlus17;
if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
diag::err_invalid_thread)
<< DeclSpec::getSpecifierName(TSCS);
// Check to see if this name was declared as a member previously
NamedDecl *PrevDecl = nullptr;
LookupResult Previous(*this, II, Loc, LookupMemberName,
RedeclarationKind::ForVisibleRedeclaration);
LookupName(Previous, S);
switch (Previous.getResultKind()) {
case LookupResultKind::Found:
case LookupResultKind::FoundUnresolvedValue:
PrevDecl = Previous.getAsSingle<NamedDecl>();
break;
case LookupResultKind::FoundOverloaded:
PrevDecl = Previous.getRepresentativeDecl();
break;
case LookupResultKind::NotFound:
case LookupResultKind::NotFoundInCurrentInstantiation:
case LookupResultKind::Ambiguous:
break;
}
Previous.suppressDiagnostics();
if (PrevDecl && PrevDecl->isTemplateParameter()) {
// Maybe we will complain about the shadowed template parameter.
DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
// Just pretend that we didn't see the previous declaration.
PrevDecl = nullptr;
}
if (PrevDecl && !isDeclInScope(PrevDecl, Record, S))
PrevDecl = nullptr;
bool Mutable
= (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable);
SourceLocation TSSL = D.getBeginLoc();
FieldDecl *NewFD
= CheckFieldDecl(II, T, TInfo, Record, Loc, Mutable, BitWidth, InitStyle,
TSSL, AS, PrevDecl, &D);
if (NewFD->isInvalidDecl())
Record->setInvalidDecl();
if (D.getDeclSpec().isModulePrivateSpecified())
NewFD->setModulePrivate();
if (NewFD->isInvalidDecl() && PrevDecl) {
// Don't introduce NewFD into scope; there's already something
// with the same name in the same scope.
} else if (II) {
PushOnScopeChains(NewFD, S);
} else
Record->addDecl(NewFD);
return NewFD;
}
FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T,
TypeSourceInfo *TInfo,
RecordDecl *Record, SourceLocation Loc,
bool Mutable, Expr *BitWidth,
InClassInitStyle InitStyle,
SourceLocation TSSL,
AccessSpecifier AS, NamedDecl *PrevDecl,
Declarator *D) {
const IdentifierInfo *II = Name.getAsIdentifierInfo();
bool InvalidDecl = false;
if (D) InvalidDecl = D->isInvalidType();
// If we receive a broken type, recover by assuming 'int' and
// marking this declaration as invalid.
if (T.isNull() || T->containsErrors()) {
InvalidDecl = true;
T = Context.IntTy;
}
QualType EltTy = Context.getBaseElementType(T);
if (!EltTy->isDependentType() && !EltTy->containsErrors()) {
bool isIncomplete =
LangOpts.HLSL // HLSL allows sizeless builtin types
? RequireCompleteType(Loc, EltTy, diag::err_incomplete_type)
: RequireCompleteSizedType(Loc, EltTy,
diag::err_field_incomplete_or_sizeless);
if (isIncomplete) {
// Fields of incomplete type force their record to be invalid.
Record->setInvalidDecl();
InvalidDecl = true;
} else {
NamedDecl *Def;
EltTy->isIncompleteType(&Def);
if (Def && Def->isInvalidDecl()) {
Record->setInvalidDecl();
InvalidDecl = true;
}
}
}
// TR 18037 does not allow fields to be declared with address space
if (T.hasAddressSpace() || T->isDependentAddressSpaceType() ||
T->getBaseElementTypeUnsafe()->isDependentAddressSpaceType()) {
Diag(Loc, diag::err_field_with_address_space);
Record->setInvalidDecl();
InvalidDecl = true;
}
if (LangOpts.OpenCL) {
// OpenCL v1.2 s6.9b,r & OpenCL v2.0 s6.12.5 - The following types cannot be
// used as structure or union field: image, sampler, event or block types.
if (T->isEventT() || T->isImageType() || T->isSamplerT() ||
T->isBlockPointerType()) {
Diag(Loc, diag::err_opencl_type_struct_or_union_field) << T;
Record->setInvalidDecl();
InvalidDecl = true;
}
// OpenCL v1.2 s6.9.c: bitfields are not supported, unless Clang extension
// is enabled.
if (BitWidth && !getOpenCLOptions().isAvailableOption(
"__cl_clang_bitfields", LangOpts)) {
Diag(Loc, diag::err_opencl_bitfields);
InvalidDecl = true;
}
}
// Anonymous bit-fields cannot be cv-qualified (CWG 2229).
if (!InvalidDecl && getLangOpts().CPlusPlus && !II && BitWidth &&
T.hasQualifiers()) {
InvalidDecl = true;
Diag(Loc, diag::err_anon_bitfield_qualifiers);
}
// C99 6.7.2.1p8: A member of a structure or union may have any type other
// than a variably modified type.
if (!InvalidDecl && T->isVariablyModifiedType()) {
if (!tryToFixVariablyModifiedVarType(
TInfo, T, Loc, diag::err_typecheck_field_variable_size))
InvalidDecl = true;
}
// Fields can not have abstract class types
if (!InvalidDecl && RequireNonAbstractType(Loc, T,
diag::err_abstract_type_in_decl,
AbstractFieldType))
InvalidDecl = true;
if (InvalidDecl)
BitWidth = nullptr;
// If this is declared as a bit-field, check the bit-field.
if (BitWidth) {
BitWidth =
VerifyBitField(Loc, II, T, Record->isMsStruct(Context), BitWidth).get();
if (!BitWidth) {
InvalidDecl = true;
BitWidth = nullptr;
}
}
// Check that 'mutable' is consistent with the type of the declaration.
if (!InvalidDecl && Mutable) {
unsigned DiagID = 0;
if (T->isReferenceType())
DiagID = getLangOpts().MSVCCompat ? diag::ext_mutable_reference
: diag::err_mutable_reference;
else if (T.isConstQualified())
DiagID = diag::err_mutable_const;
if (DiagID) {
SourceLocation ErrLoc = Loc;
if (D && D->getDeclSpec().getStorageClassSpecLoc().isValid())
ErrLoc = D->getDeclSpec().getStorageClassSpecLoc();
Diag(ErrLoc, DiagID);
if (DiagID != diag::ext_mutable_reference) {
Mutable = false;
InvalidDecl = true;
}
}
}
// C++11 [class.union]p8 (DR1460):
// At most one variant member of a union may have a
// brace-or-equal-initializer.
if (InitStyle != ICIS_NoInit)
checkDuplicateDefaultInit(*this, cast<CXXRecordDecl>(Record), Loc);
FieldDecl *NewFD = FieldDecl::Create(Context, Record, TSSL, Loc, II, T, TInfo,
BitWidth, Mutable, InitStyle);
if (InvalidDecl)
NewFD->setInvalidDecl();
if (!InvalidDecl)
warnOnCTypeHiddenInCPlusPlus(NewFD);
if (PrevDecl && !isa<TagDecl>(PrevDecl) &&
!PrevDecl->isPlaceholderVar(getLangOpts())) {
Diag(Loc, diag::err_duplicate_member) << II;
Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
NewFD->setInvalidDecl();
}
if (!InvalidDecl && getLangOpts().CPlusPlus) {
if (Record->isUnion()) {
if (const auto *RD = EltTy->getAsCXXRecordDecl();
RD && (RD->isBeingDefined() || RD->isCompleteDefinition())) {
// C++ [class.union]p1: An object of a class with a non-trivial
// constructor, a non-trivial copy constructor, a non-trivial
// destructor, or a non-trivial copy assignment operator
// cannot be a member of a union, nor can an array of such
// objects.
if (CheckNontrivialField(NewFD))
NewFD->setInvalidDecl();
}
// C++ [class.union]p1: If a union contains a member of reference type,
// the program is ill-formed, except when compiling with MSVC extensions
// enabled.
if (EltTy->isReferenceType()) {
const bool HaveMSExt =
getLangOpts().MicrosoftExt &&
!getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015);
Diag(NewFD->getLocation(),
HaveMSExt ? diag::ext_union_member_of_reference_type
: diag::err_union_member_of_reference_type)
<< NewFD->getDeclName() << EltTy;
if (!HaveMSExt)
NewFD->setInvalidDecl();
}
}
}
// FIXME: We need to pass in the attributes given an AST
// representation, not a parser representation.
if (D) {
// FIXME: The current scope is almost... but not entirely... correct here.
ProcessDeclAttributes(getCurScope(), NewFD, *D);
if (NewFD->hasAttrs())
CheckAlignasUnderalignment(NewFD);
}
// In auto-retain/release, infer strong retension for fields of
// retainable type.
if (getLangOpts().ObjCAutoRefCount && ObjC().inferObjCARCLifetime(NewFD))
NewFD->setInvalidDecl();
if (T.isObjCGCWeak())
Diag(Loc, diag::warn_attribute_weak_on_field);
// PPC MMA non-pointer types are not allowed as field types.
if (Context.getTargetInfo().getTriple().isPPC64() &&
PPC().CheckPPCMMAType(T, NewFD->getLocation()))
NewFD->setInvalidDecl();
NewFD->setAccess(AS);
return NewFD;
}
bool Sema::CheckNontrivialField(FieldDecl *FD) {
assert(FD);
assert(getLangOpts().CPlusPlus && "valid check only for C++");
if (FD->isInvalidDecl() || FD->getType()->isDependentType())
return false;
QualType EltTy = Context.getBaseElementType(FD->getType());
if (const auto *RDecl = EltTy->getAsCXXRecordDecl();
RDecl && (RDecl->isBeingDefined() || RDecl->isCompleteDefinition())) {
// We check for copy constructors before constructors
// because otherwise we'll never get complaints about
// copy constructors.
CXXSpecialMemberKind member = CXXSpecialMemberKind::Invalid;
// We're required to check for any non-trivial constructors. Since the
// implicit default constructor is suppressed if there are any
// user-declared constructors, we just need to check that there is a
// trivial default constructor and a trivial copy constructor. (We don't
// worry about move constructors here, since this is a C++98 check.)
if (RDecl->hasNonTrivialCopyConstructor())
member = CXXSpecialMemberKind::CopyConstructor;
else if (!RDecl->hasTrivialDefaultConstructor())
member = CXXSpecialMemberKind::DefaultConstructor;
else if (RDecl->hasNonTrivialCopyAssignment())
member = CXXSpecialMemberKind::CopyAssignment;
else if (RDecl->hasNonTrivialDestructor())
member = CXXSpecialMemberKind::Destructor;
if (member != CXXSpecialMemberKind::Invalid) {
if (!getLangOpts().CPlusPlus11 && getLangOpts().ObjCAutoRefCount &&
RDecl->hasObjectMember()) {
// Objective-C++ ARC: it is an error to have a non-trivial field of
// a union. However, system headers in Objective-C programs
// occasionally have Objective-C lifetime objects within unions,
// and rather than cause the program to fail, we make those
// members unavailable.
SourceLocation Loc = FD->getLocation();
if (getSourceManager().isInSystemHeader(Loc)) {
if (!FD->hasAttr<UnavailableAttr>())
FD->addAttr(UnavailableAttr::CreateImplicit(
Context, "", UnavailableAttr::IR_ARCFieldWithOwnership, Loc));
return false;
}
}
Diag(FD->getLocation(),
getLangOpts().CPlusPlus11
? diag::warn_cxx98_compat_nontrivial_union_or_anon_struct_member
: diag::err_illegal_union_or_anon_struct_member)
<< FD->getParent()->isUnion() << FD->getDeclName() << member;
DiagnoseNontrivial(RDecl, member);
return !getLangOpts().CPlusPlus11;
}
}
return false;
}
void Sema::ActOnLastBitfield(SourceLocation DeclLoc,
SmallVectorImpl<Decl *> &AllIvarDecls) {
if (LangOpts.ObjCRuntime.isFragile() || AllIvarDecls.empty())
return;
Decl *ivarDecl = AllIvarDecls[AllIvarDecls.size()-1];
ObjCIvarDecl *Ivar = cast<ObjCIvarDecl>(ivarDecl);
if (!Ivar->isBitField() || Ivar->isZeroLengthBitField())
return;
ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CurContext);
if (!ID) {
if (ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(CurContext)) {
if (!CD->IsClassExtension())
return;
}
// No need to add this to end of @implementation.
else
return;
}
// All conditions are met. Add a new bitfield to the tail end of ivars.
llvm::APInt Zero(Context.getTypeSize(Context.IntTy), 0);
Expr * BW = IntegerLiteral::Create(Context, Zero, Context.IntTy, DeclLoc);
Expr *BitWidth =
ConstantExpr::Create(Context, BW, APValue(llvm::APSInt(Zero)));
Ivar = ObjCIvarDecl::Create(
Context, cast<ObjCContainerDecl>(CurContext), DeclLoc, DeclLoc, nullptr,
Context.CharTy, Context.getTrivialTypeSourceInfo(Context.CharTy, DeclLoc),
ObjCIvarDecl::Private, BitWidth, true);
AllIvarDecls.push_back(Ivar);
}
/// [class.dtor]p4:
/// At the end of the definition of a class, overload resolution is
/// performed among the prospective destructors declared in that class with
/// an empty argument list to select the destructor for the class, also
/// known as the selected destructor.
///
/// We do the overload resolution here, then mark the selected constructor in the AST.
/// Later CXXRecordDecl::getDestructor() will return the selected constructor.
static void ComputeSelectedDestructor(Sema &S, CXXRecordDecl *Record) {
if (!Record->hasUserDeclaredDestructor()) {
return;
}
SourceLocation Loc = Record->getLocation();
OverloadCandidateSet OCS(Loc, OverloadCandidateSet::CSK_Normal);
for (auto *Decl : Record->decls()) {
if (auto *DD = dyn_cast<CXXDestructorDecl>(Decl)) {
if (DD->isInvalidDecl())
continue;
S.AddOverloadCandidate(DD, DeclAccessPair::make(DD, DD->getAccess()), {},
OCS);
assert(DD->isIneligibleOrNotSelected() && "Selecting a destructor but a destructor was already selected.");
}
}
if (OCS.empty()) {
return;
}
OverloadCandidateSet::iterator Best;
unsigned Msg = 0;
OverloadCandidateDisplayKind DisplayKind;
switch (OCS.BestViableFunction(S, Loc, Best)) {
case OR_Success:
case OR_Deleted:
Record->addedSelectedDestructor(dyn_cast<CXXDestructorDecl>(Best->Function));
break;
case OR_Ambiguous:
Msg = diag::err_ambiguous_destructor;
DisplayKind = OCD_AmbiguousCandidates;
break;
case OR_No_Viable_Function:
Msg = diag::err_no_viable_destructor;
DisplayKind = OCD_AllCandidates;
break;
}
if (Msg) {
// OpenCL have got their own thing going with destructors. It's slightly broken,
// but we allow it.
if (!S.LangOpts.OpenCL) {
PartialDiagnostic Diag = S.PDiag(Msg) << Record;
OCS.NoteCandidates(PartialDiagnosticAt(Loc, Diag), S, DisplayKind, {});
Record->setInvalidDecl();
}
// It's a bit hacky: At this point we've raised an error but we want the
// rest of the compiler to continue somehow working. However almost
// everything we'll try to do with the class will depend on there being a
// destructor. So let's pretend the first one is selected and hope for the
// best.
Record->addedSelectedDestructor(dyn_cast<CXXDestructorDecl>(OCS.begin()->Function));
}
}
/// [class.mem.special]p5
/// Two special member functions are of the same kind if:
/// - they are both default constructors,
/// - they are both copy or move constructors with the same first parameter
/// type, or
/// - they are both copy or move assignment operators with the same first
/// parameter type and the same cv-qualifiers and ref-qualifier, if any.
static bool AreSpecialMemberFunctionsSameKind(ASTContext &Context,
CXXMethodDecl *M1,
CXXMethodDecl *M2,
CXXSpecialMemberKind CSM) {
// We don't want to compare templates to non-templates: See
// https://github.com/llvm/llvm-project/issues/59206
if (CSM == CXXSpecialMemberKind::DefaultConstructor)
return bool(M1->getDescribedFunctionTemplate()) ==
bool(M2->getDescribedFunctionTemplate());
// FIXME: better resolve CWG
// https://cplusplus.github.io/CWG/issues/2787.html
if (!Context.hasSameType(M1->getNonObjectParameter(0)->getType(),
M2->getNonObjectParameter(0)->getType()))
return false;
if (!Context.hasSameType(M1->getFunctionObjectParameterReferenceType(),
M2->getFunctionObjectParameterReferenceType()))
return false;
return true;
}
/// [class.mem.special]p6:
/// An eligible special member function is a special member function for which:
/// - the function is not deleted,
/// - the associated constraints, if any, are satisfied, and
/// - no special member function of the same kind whose associated constraints
/// [CWG2595], if any, are satisfied is more constrained.
static void SetEligibleMethods(Sema &S, CXXRecordDecl *Record,
ArrayRef<CXXMethodDecl *> Methods,
CXXSpecialMemberKind CSM) {
SmallVector<bool, 4> SatisfactionStatus;
for (CXXMethodDecl *Method : Methods) {
if (!Method->getTrailingRequiresClause())
SatisfactionStatus.push_back(true);
else {
ConstraintSatisfaction Satisfaction;
if (S.CheckFunctionConstraints(Method, Satisfaction))
SatisfactionStatus.push_back(false);
else
SatisfactionStatus.push_back(Satisfaction.IsSatisfied);
}
}
for (size_t i = 0; i < Methods.size(); i++) {
if (!SatisfactionStatus[i])
continue;
CXXMethodDecl *Method = Methods[i];
CXXMethodDecl *OrigMethod = Method;
if (FunctionDecl *MF = OrigMethod->getInstantiatedFromMemberFunction())
OrigMethod = cast<CXXMethodDecl>(MF);
AssociatedConstraint Orig = OrigMethod->getTrailingRequiresClause();
bool AnotherMethodIsMoreConstrained = false;
for (size_t j = 0; j < Methods.size(); j++) {
if (i == j || !SatisfactionStatus[j])
continue;
CXXMethodDecl *OtherMethod = Methods[j];
if (FunctionDecl *MF = OtherMethod->getInstantiatedFromMemberFunction())
OtherMethod = cast<CXXMethodDecl>(MF);
if (!AreSpecialMemberFunctionsSameKind(S.Context, OrigMethod, OtherMethod,
CSM))
continue;
AssociatedConstraint Other = OtherMethod->getTrailingRequiresClause();
if (!Other)
continue;
if (!Orig) {
AnotherMethodIsMoreConstrained = true;
break;
}
if (S.IsAtLeastAsConstrained(OtherMethod, {Other}, OrigMethod, {Orig},
AnotherMethodIsMoreConstrained)) {
// There was an error with the constraints comparison. Exit the loop
// and don't consider this function eligible.
AnotherMethodIsMoreConstrained = true;
}
if (AnotherMethodIsMoreConstrained)
break;
}
// FIXME: Do not consider deleted methods as eligible after implementing
// DR1734 and DR1496.
if (!AnotherMethodIsMoreConstrained) {
Method->setIneligibleOrNotSelected(false);
Record->addedEligibleSpecialMemberFunction(Method,
1 << llvm::to_underlying(CSM));
}
}
}
static void ComputeSpecialMemberFunctionsEligiblity(Sema &S,
CXXRecordDecl *Record) {
SmallVector<CXXMethodDecl *, 4> DefaultConstructors;
SmallVector<CXXMethodDecl *, 4> CopyConstructors;
SmallVector<CXXMethodDecl *, 4> MoveConstructors;
SmallVector<CXXMethodDecl *, 4> CopyAssignmentOperators;
SmallVector<CXXMethodDecl *, 4> MoveAssignmentOperators;
for (auto *Decl : Record->decls()) {
auto *MD = dyn_cast<CXXMethodDecl>(Decl);
if (!MD) {
auto *FTD = dyn_cast<FunctionTemplateDecl>(Decl);
if (FTD)
MD = dyn_cast<CXXMethodDecl>(FTD->getTemplatedDecl());
}
if (!MD)
continue;
if (auto *CD = dyn_cast<CXXConstructorDecl>(MD)) {
if (CD->isInvalidDecl())
continue;
if (CD->isDefaultConstructor())
DefaultConstructors.push_back(MD);
else if (CD->isCopyConstructor())
CopyConstructors.push_back(MD);
else if (CD->isMoveConstructor())
MoveConstructors.push_back(MD);
} else if (MD->isCopyAssignmentOperator()) {
CopyAssignmentOperators.push_back(MD);
} else if (MD->isMoveAssignmentOperator()) {
MoveAssignmentOperators.push_back(MD);
}
}
SetEligibleMethods(S, Record, DefaultConstructors,
CXXSpecialMemberKind::DefaultConstructor);
SetEligibleMethods(S, Record, CopyConstructors,
CXXSpecialMemberKind::CopyConstructor);
SetEligibleMethods(S, Record, MoveConstructors,
CXXSpecialMemberKind::MoveConstructor);
SetEligibleMethods(S, Record, CopyAssignmentOperators,
CXXSpecialMemberKind::CopyAssignment);
SetEligibleMethods(S, Record, MoveAssignmentOperators,
CXXSpecialMemberKind::MoveAssignment);
}
bool Sema::EntirelyFunctionPointers(const RecordDecl *Record) {
// Check to see if a FieldDecl is a pointer to a function.
auto IsFunctionPointerOrForwardDecl = [&](const Decl *D) {
const FieldDecl *FD = dyn_cast<FieldDecl>(D);
if (!FD) {
// Check whether this is a forward declaration that was inserted by
// Clang. This happens when a non-forward declared / defined type is
// used, e.g.:
//
// struct foo {
// struct bar *(*f)();
// struct bar *(*g)();
// };
//
// "struct bar" shows up in the decl AST as a "RecordDecl" with an
// incomplete definition.
if (const auto *TD = dyn_cast<TagDecl>(D))
return !TD->isCompleteDefinition();
return false;
}
QualType FieldType = FD->getType().getDesugaredType(Context);
if (isa<PointerType>(FieldType)) {
QualType PointeeType = cast<PointerType>(FieldType)->getPointeeType();
return PointeeType.getDesugaredType(Context)->isFunctionType();
}
// If a member is a struct entirely of function pointers, that counts too.
if (const auto *Record = FieldType->getAsRecordDecl();
Record && Record->isStruct() && EntirelyFunctionPointers(Record))
return true;
return false;
};
return llvm::all_of(Record->decls(), IsFunctionPointerOrForwardDecl);
}
void Sema::ActOnFields(Scope *S, SourceLocation RecLoc, Decl *EnclosingDecl,
ArrayRef<Decl *> Fields, SourceLocation LBrac,
SourceLocation RBrac,
const ParsedAttributesView &Attrs) {
assert(EnclosingDecl && "missing record or interface decl");
// If this is an Objective-C @implementation or category and we have
// new fields here we should reset the layout of the interface since
// it will now change.
if (!Fields.empty() && isa<ObjCContainerDecl>(EnclosingDecl)) {
ObjCContainerDecl *DC = cast<ObjCContainerDecl>(EnclosingDecl);
switch (DC->getKind()) {
default: break;
case Decl::ObjCCategory:
Context.ResetObjCLayout(cast<ObjCCategoryDecl>(DC)->getClassInterface());
break;
case Decl::ObjCImplementation:
Context.
ResetObjCLayout(cast<ObjCImplementationDecl>(DC)->getClassInterface());
break;
}
}
RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl);
CXXRecordDecl *CXXRecord = dyn_cast<CXXRecordDecl>(EnclosingDecl);
// Start counting up the number of named members; make sure to include
// members of anonymous structs and unions in the total.
unsigned NumNamedMembers = 0;
if (Record) {
for (const auto *I : Record->decls()) {
if (const auto *IFD = dyn_cast<IndirectFieldDecl>(I))
if (IFD->getDeclName())
++NumNamedMembers;
}
}
// Verify that all the fields are okay.
SmallVector<FieldDecl*, 32> RecFields;
const FieldDecl *PreviousField = nullptr;
for (ArrayRef<Decl *>::iterator i = Fields.begin(), end = Fields.end();
i != end; PreviousField = cast<FieldDecl>(*i), ++i) {
FieldDecl *FD = cast<FieldDecl>(*i);
// Get the type for the field.
const Type *FDTy = FD->getType().getTypePtr();
if (!FD->isAnonymousStructOrUnion()) {
// Remember all fields written by the user.
RecFields.push_back(FD);
}
// If the field is already invalid for some reason, don't emit more
// diagnostics about it.
if (FD->isInvalidDecl()) {
EnclosingDecl->setInvalidDecl();
continue;
}
// C99 6.7.2.1p2:
// A structure or union shall not contain a member with
// incomplete or function type (hence, a structure shall not
// contain an instance of itself, but may contain a pointer to
// an instance of itself), except that the last member of a
// structure with more than one named member may have incomplete
// array type; such a structure (and any union containing,
// possibly recursively, a member that is such a structure)
// shall not be a member of a structure or an element of an
// array.
bool IsLastField = (i + 1 == Fields.end());
if (FDTy->isFunctionType()) {
// Field declared as a function.
Diag(FD->getLocation(), diag::err_field_declared_as_function)
<< FD->getDeclName();
FD->setInvalidDecl();
EnclosingDecl->setInvalidDecl();
continue;
} else if (FDTy->isIncompleteArrayType() &&
(Record || isa<ObjCContainerDecl>(EnclosingDecl))) {
if (Record) {
// Flexible array member.
// Microsoft and g++ is more permissive regarding flexible array.
// It will accept flexible array in union and also
// as the sole element of a struct/class.
unsigned DiagID = 0;
if (!Record->isUnion() && !IsLastField) {
Diag(FD->getLocation(), diag::err_flexible_array_not_at_end)
<< FD->getDeclName() << FD->getType() << Record->getTagKind();
Diag((*(i + 1))->getLocation(), diag::note_next_field_declaration);
FD->setInvalidDecl();
EnclosingDecl->setInvalidDecl();
continue;
} else if (Record->isUnion())
DiagID = getLangOpts().MicrosoftExt
? diag::ext_flexible_array_union_ms
: diag::ext_flexible_array_union_gnu;
else if (NumNamedMembers < 1)
DiagID = getLangOpts().MicrosoftExt
? diag::ext_flexible_array_empty_aggregate_ms
: diag::ext_flexible_array_empty_aggregate_gnu;
if (DiagID)
Diag(FD->getLocation(), DiagID)
<< FD->getDeclName() << Record->getTagKind();
// While the layout of types that contain virtual bases is not specified
// by the C++ standard, both the Itanium and Microsoft C++ ABIs place
// virtual bases after the derived members. This would make a flexible
// array member declared at the end of an object not adjacent to the end
// of the type.
if (CXXRecord && CXXRecord->getNumVBases() != 0)
Diag(FD->getLocation(), diag::err_flexible_array_virtual_base)
<< FD->getDeclName() << Record->getTagKind();
if (!getLangOpts().C99)
Diag(FD->getLocation(), diag::ext_c99_flexible_array_member)
<< FD->getDeclName() << Record->getTagKind();
// If the element type has a non-trivial destructor, we would not
// implicitly destroy the elements, so disallow it for now.
//
// FIXME: GCC allows this. We should probably either implicitly delete
// the destructor of the containing class, or just allow this.
QualType BaseElem = Context.getBaseElementType(FD->getType());
if (!BaseElem->isDependentType() && BaseElem.isDestructedType()) {
Diag(FD->getLocation(), diag::err_flexible_array_has_nontrivial_dtor)
<< FD->getDeclName() << FD->getType();
FD->setInvalidDecl();
EnclosingDecl->setInvalidDecl();
continue;
}
// Okay, we have a legal flexible array member at the end of the struct.
Record->setHasFlexibleArrayMember(true);
} else {
// In ObjCContainerDecl ivars with incomplete array type are accepted,
// unless they are followed by another ivar. That check is done
// elsewhere, after synthesized ivars are known.
}
} else if (!FDTy->isDependentType() &&
(LangOpts.HLSL // HLSL allows sizeless builtin types
? RequireCompleteType(FD->getLocation(), FD->getType(),
diag::err_incomplete_type)
: RequireCompleteSizedType(
FD->getLocation(), FD->getType(),
diag::err_field_incomplete_or_sizeless))) {
// Incomplete type
FD->setInvalidDecl();
EnclosingDecl->setInvalidDecl();
continue;
} else if (const auto *RD = FDTy->getAsRecordDecl()) {
if (Record && RD->hasFlexibleArrayMember()) {
// A type which contains a flexible array member is considered to be a
// flexible array member.
Record->setHasFlexibleArrayMember(true);
if (!Record->isUnion()) {
// If this is a struct/class and this is not the last element, reject
// it. Note that GCC supports variable sized arrays in the middle of
// structures.
if (!IsLastField)
Diag(FD->getLocation(), diag::ext_variable_sized_type_in_struct)
<< FD->getDeclName() << FD->getType();
else {
// We support flexible arrays at the end of structs in
// other structs as an extension.
Diag(FD->getLocation(), diag::ext_flexible_array_in_struct)
<< FD->getDeclName();
}
}
}
if (isa<ObjCContainerDecl>(EnclosingDecl) &&
RequireNonAbstractType(FD->getLocation(), FD->getType(),
diag::err_abstract_type_in_decl,
AbstractIvarType)) {
// Ivars can not have abstract class types
FD->setInvalidDecl();
}
if (Record && RD->hasObjectMember())
Record->setHasObjectMember(true);
if (Record && RD->hasVolatileMember())
Record->setHasVolatileMember(true);
} else if (FDTy->isObjCObjectType()) {
/// A field cannot be an Objective-c object
Diag(FD->getLocation(), diag::err_statically_allocated_object)
<< FixItHint::CreateInsertion(FD->getLocation(), "*");
QualType T = Context.getObjCObjectPointerType(FD->getType());
FD->setType(T);
} else if (Record && Record->isUnion() &&
FD->getType().hasNonTrivialObjCLifetime() &&
getSourceManager().isInSystemHeader(FD->getLocation()) &&
!getLangOpts().CPlusPlus && !FD->hasAttr<UnavailableAttr>() &&
(FD->getType().getObjCLifetime() != Qualifiers::OCL_Strong ||
!Context.hasDirectOwnershipQualifier(FD->getType()))) {
// For backward compatibility, fields of C unions declared in system
// headers that have non-trivial ObjC ownership qualifications are marked
// as unavailable unless the qualifier is explicit and __strong. This can
// break ABI compatibility between programs compiled with ARC and MRR, but
// is a better option than rejecting programs using those unions under
// ARC.
FD->addAttr(UnavailableAttr::CreateImplicit(
Context, "", UnavailableAttr::IR_ARCFieldWithOwnership,
FD->getLocation()));
} else if (getLangOpts().ObjC &&
getLangOpts().getGC() != LangOptions::NonGC && Record &&
!Record->hasObjectMember()) {
if (FD->getType()->isObjCObjectPointerType() ||
FD->getType().isObjCGCStrong())
Record->setHasObjectMember(true);
else if (Context.getAsArrayType(FD->getType())) {
QualType BaseType = Context.getBaseElementType(FD->getType());
if (const auto *RD = BaseType->getAsRecordDecl();
RD && RD->hasObjectMember())
Record->setHasObjectMember(true);
else if (BaseType->isObjCObjectPointerType() ||
BaseType.isObjCGCStrong())
Record->setHasObjectMember(true);
}
}
if (Record && !getLangOpts().CPlusPlus &&
!shouldIgnoreForRecordTriviality(FD)) {
QualType FT = FD->getType();
if (FT.isNonTrivialToPrimitiveDefaultInitialize()) {
Record->setNonTrivialToPrimitiveDefaultInitialize(true);
if (FT.hasNonTrivialToPrimitiveDefaultInitializeCUnion() ||
Record->isUnion())
Record->setHasNonTrivialToPrimitiveDefaultInitializeCUnion(true);
}
QualType::PrimitiveCopyKind PCK = FT.isNonTrivialToPrimitiveCopy();
if (PCK != QualType::PCK_Trivial && PCK != QualType::PCK_VolatileTrivial) {
Record->setNonTrivialToPrimitiveCopy(true);
if (FT.hasNonTrivialToPrimitiveCopyCUnion() || Record->isUnion())
Record->setHasNonTrivialToPrimitiveCopyCUnion(true);
}
if (FD->hasAttr<ExplicitInitAttr>())
Record->setHasUninitializedExplicitInitFields(true);
if (FT.isDestructedType()) {
Record->setNonTrivialToPrimitiveDestroy(true);
Record->setParamDestroyedInCallee(true);
if (FT.hasNonTrivialToPrimitiveDestructCUnion() || Record->isUnion())
Record->setHasNonTrivialToPrimitiveDestructCUnion(true);
}
if (const auto *RD = FT->getAsRecordDecl()) {
if (RD->getArgPassingRestrictions() ==
RecordArgPassingKind::CanNeverPassInRegs)
Record->setArgPassingRestrictions(
RecordArgPassingKind::CanNeverPassInRegs);
} else if (FT.getQualifiers().getObjCLifetime() == Qualifiers::OCL_Weak) {
Record->setArgPassingRestrictions(
RecordArgPassingKind::CanNeverPassInRegs);
} else if (PointerAuthQualifier Q = FT.getPointerAuth();
Q && Q.isAddressDiscriminated()) {
Record->setArgPassingRestrictions(
RecordArgPassingKind::CanNeverPassInRegs);
Record->setNonTrivialToPrimitiveCopy(true);
}
}
if (Record && FD->getType().isVolatileQualified())
Record->setHasVolatileMember(true);
bool ReportMSBitfieldStoragePacking =
Record && PreviousField &&
!Diags.isIgnored(diag::warn_ms_bitfield_mismatched_storage_packing,
Record->getLocation());
auto IsNonDependentBitField = [](const FieldDecl *FD) {
return FD->isBitField() && !FD->getType()->isDependentType();
};
if (ReportMSBitfieldStoragePacking && IsNonDependentBitField(FD) &&
IsNonDependentBitField(PreviousField)) {
CharUnits FDStorageSize = Context.getTypeSizeInChars(FD->getType());
CharUnits PreviousFieldStorageSize =
Context.getTypeSizeInChars(PreviousField->getType());
if (FDStorageSize != PreviousFieldStorageSize) {
Diag(FD->getLocation(),
diag::warn_ms_bitfield_mismatched_storage_packing)
<< FD << FD->getType() << FDStorageSize.getQuantity()
<< PreviousFieldStorageSize.getQuantity();
Diag(PreviousField->getLocation(),
diag::note_ms_bitfield_mismatched_storage_size_previous)
<< PreviousField << PreviousField->getType();
}
}
// Keep track of the number of named members.
if (FD->getIdentifier())
++NumNamedMembers;
}
// Okay, we successfully defined 'Record'.
if (Record) {
bool Completed = false;
if (S) {
Scope *Parent = S->getParent();
if (Parent && Parent->isTypeAliasScope() &&
Parent->isTemplateParamScope())
Record->setInvalidDecl();
}
if (CXXRecord) {
if (!CXXRecord->isInvalidDecl()) {
// Set access bits correctly on the directly-declared conversions.
for (CXXRecordDecl::conversion_iterator
I = CXXRecord->conversion_begin(),
E = CXXRecord->conversion_end(); I != E; ++I)
I.setAccess((*I)->getAccess());
}
// Add any implicitly-declared members to this class.
AddImplicitlyDeclaredMembersToClass(CXXRecord);
if (!CXXRecord->isDependentType()) {
if (!CXXRecord->isInvalidDecl()) {
// If we have virtual base classes, we may end up finding multiple
// final overriders for a given virtual function. Check for this
// problem now.
if (CXXRecord->getNumVBases()) {
CXXFinalOverriderMap FinalOverriders;
CXXRecord->getFinalOverriders(FinalOverriders);
for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
MEnd = FinalOverriders.end();
M != MEnd; ++M) {
for (OverridingMethods::iterator SO = M->second.begin(),
SOEnd = M->second.end();
SO != SOEnd; ++SO) {
assert(SO->second.size() > 0 &&
"Virtual function without overriding functions?");
if (SO->second.size() == 1)
continue;
// C++ [class.virtual]p2:
// In a derived class, if a virtual member function of a base
// class subobject has more than one final overrider the
// program is ill-formed.
Diag(Record->getLocation(), diag::err_multiple_final_overriders)
<< (const NamedDecl *)M->first << Record;
Diag(M->first->getLocation(),
diag::note_overridden_virtual_function);
for (OverridingMethods::overriding_iterator
OM = SO->second.begin(),
OMEnd = SO->second.end();
OM != OMEnd; ++OM)
Diag(OM->Method->getLocation(), diag::note_final_overrider)
<< (const NamedDecl *)M->first << OM->Method->getParent();
Record->setInvalidDecl();
}
}
CXXRecord->completeDefinition(&FinalOverriders);
Completed = true;
}
}
ComputeSelectedDestructor(*this, CXXRecord);
ComputeSpecialMemberFunctionsEligiblity(*this, CXXRecord);
}
}
if (!Completed)
Record->completeDefinition();
// Handle attributes before checking the layout.
ProcessDeclAttributeList(S, Record, Attrs);
// Maybe randomize the record's decls. We automatically randomize a record
// of function pointers, unless it has the "no_randomize_layout" attribute.
if (!getLangOpts().CPlusPlus && !getLangOpts().RandstructSeed.empty() &&
!Record->isRandomized() && !Record->isUnion() &&
(Record->hasAttr<RandomizeLayoutAttr>() ||
(!Record->hasAttr<NoRandomizeLayoutAttr>() &&
EntirelyFunctionPointers(Record)))) {
SmallVector<Decl *, 32> NewDeclOrdering;
if (randstruct::randomizeStructureLayout(Context, Record,
NewDeclOrdering))
Record->reorderDecls(NewDeclOrdering);
}
// We may have deferred checking for a deleted destructor. Check now.
if (CXXRecord) {
auto *Dtor = CXXRecord->getDestructor();
if (Dtor && Dtor->isImplicit() &&
ShouldDeleteSpecialMember(Dtor, CXXSpecialMemberKind::Destructor)) {
CXXRecord->setImplicitDestructorIsDeleted();
SetDeclDeleted(Dtor, CXXRecord->getLocation());
}
}
if (Record->hasAttrs()) {
CheckAlignasUnderalignment(Record);
if (const MSInheritanceAttr *IA = Record->getAttr<MSInheritanceAttr>())
checkMSInheritanceAttrOnDefinition(cast<CXXRecordDecl>(Record),
IA->getRange(), IA->getBestCase(),
IA->getInheritanceModel());
}
// Check if the structure/union declaration is a type that can have zero
// size in C. For C this is a language extension, for C++ it may cause
// compatibility problems.
bool CheckForZeroSize;
if (!getLangOpts().CPlusPlus) {
CheckForZeroSize = true;
} else {
// For C++ filter out types that cannot be referenced in C code.
CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record);
CheckForZeroSize =
CXXRecord->getLexicalDeclContext()->isExternCContext() &&
!CXXRecord->isDependentType() && !inTemplateInstantiation() &&
CXXRecord->isCLike();
}
if (CheckForZeroSize) {
bool ZeroSize = true;
bool IsEmpty = true;
unsigned NonBitFields = 0;
for (RecordDecl::field_iterator I = Record->field_begin(),
E = Record->field_end();
(NonBitFields == 0 || ZeroSize) && I != E; ++I) {
IsEmpty = false;
if (I->isUnnamedBitField()) {
if (!I->isZeroLengthBitField())
ZeroSize = false;
} else {
++NonBitFields;
QualType FieldType = I->getType();
if (FieldType->isIncompleteType() ||
!Context.getTypeSizeInChars(FieldType).isZero())
ZeroSize = false;
}
}
// Empty structs are an extension in C (C99 6.7.2.1p7). They are
// allowed in C++, but warn if its declaration is inside
// extern "C" block.
if (ZeroSize) {
Diag(RecLoc, getLangOpts().CPlusPlus ?
diag::warn_zero_size_struct_union_in_extern_c :
diag::warn_zero_size_struct_union_compat)
<< IsEmpty << Record->isUnion() << (NonBitFields > 1);
}
// Structs without named members are extension in C (C99 6.7.2.1p7),
// but are accepted by GCC. In C2y, this became implementation-defined
// (C2y 6.7.3.2p10).
if (NonBitFields == 0 && !getLangOpts().CPlusPlus && !getLangOpts().C2y) {
Diag(RecLoc, IsEmpty ? diag::ext_empty_struct_union
: diag::ext_no_named_members_in_struct_union)
<< Record->isUnion();
}
}
} else {
ObjCIvarDecl **ClsFields =
reinterpret_cast<ObjCIvarDecl**>(RecFields.data());
if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) {
ID->setEndOfDefinitionLoc(RBrac);
// Add ivar's to class's DeclContext.
for (unsigned i = 0, e = RecFields.size(); i != e; ++i) {
ClsFields[i]->setLexicalDeclContext(ID);
ID->addDecl(ClsFields[i]);
}
// Must enforce the rule that ivars in the base classes may not be
// duplicates.
if (ID->getSuperClass())
ObjC().DiagnoseDuplicateIvars(ID, ID->getSuperClass());
} else if (ObjCImplementationDecl *IMPDecl =
dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) {
assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl");
for (unsigned I = 0, N = RecFields.size(); I != N; ++I)
// Ivar declared in @implementation never belongs to the implementation.
// Only it is in implementation's lexical context.
ClsFields[I]->setLexicalDeclContext(IMPDecl);
ObjC().CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(),
RBrac);
IMPDecl->setIvarLBraceLoc(LBrac);
IMPDecl->setIvarRBraceLoc(RBrac);
} else if (ObjCCategoryDecl *CDecl =
dyn_cast<ObjCCategoryDecl>(EnclosingDecl)) {
// case of ivars in class extension; all other cases have been
// reported as errors elsewhere.
// FIXME. Class extension does not have a LocEnd field.
// CDecl->setLocEnd(RBrac);
// Add ivar's to class extension's DeclContext.
// Diagnose redeclaration of private ivars.
ObjCInterfaceDecl *IDecl = CDecl->getClassInterface();
for (unsigned i = 0, e = RecFields.size(); i != e; ++i) {
if (IDecl) {
if (const ObjCIvarDecl *ClsIvar =
IDecl->getIvarDecl(ClsFields[i]->getIdentifier())) {
Diag(ClsFields[i]->getLocation(),
diag::err_duplicate_ivar_declaration);
Diag(ClsIvar->getLocation(), diag::note_previous_definition);
continue;
}
for (const auto *Ext : IDecl->known_extensions()) {
if (const ObjCIvarDecl *ClsExtIvar
= Ext->getIvarDecl(ClsFields[i]->getIdentifier())) {
Diag(ClsFields[i]->getLocation(),
diag::err_duplicate_ivar_declaration);
Diag(ClsExtIvar->getLocation(), diag::note_previous_definition);
continue;
}
}
}
ClsFields[i]->setLexicalDeclContext(CDecl);
CDecl->addDecl(ClsFields[i]);
}
CDecl->setIvarLBraceLoc(LBrac);
CDecl->setIvarRBraceLoc(RBrac);
}
}
ProcessAPINotes(Record);
}
// Given an integral type, return the next larger integral type
// (or a NULL type of no such type exists).
static QualType getNextLargerIntegralType(ASTContext &Context, QualType T) {
// FIXME: Int128/UInt128 support, which also needs to be introduced into
// enum checking below.
assert((T->isIntegralType(Context) ||
T->isEnumeralType()) && "Integral type required!");
const unsigned NumTypes = 4;
QualType SignedIntegralTypes[NumTypes] = {
Context.ShortTy, Context.IntTy, Context.LongTy, Context.LongLongTy
};
QualType UnsignedIntegralTypes[NumTypes] = {
Context.UnsignedShortTy, Context.UnsignedIntTy, Context.UnsignedLongTy,
Context.UnsignedLongLongTy
};
unsigned BitWidth = Context.getTypeSize(T);
QualType *Types = T->isSignedIntegerOrEnumerationType()? SignedIntegralTypes
: UnsignedIntegralTypes;
for (unsigned I = 0; I != NumTypes; ++I)
if (Context.getTypeSize(Types[I]) > BitWidth)
return Types[I];
return QualType();
}
EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum,
EnumConstantDecl *LastEnumConst,
SourceLocation IdLoc,
IdentifierInfo *Id,
Expr *Val) {
unsigned IntWidth = Context.getTargetInfo().getIntWidth();
llvm::APSInt EnumVal(IntWidth);
QualType EltTy;
if (Val && DiagnoseUnexpandedParameterPack(Val, UPPC_EnumeratorValue))
Val = nullptr;
if (Val)
Val = DefaultLvalueConversion(Val).get();
if (Val) {
if (Enum->isDependentType() || Val->isTypeDependent() ||
Val->containsErrors())
EltTy = Context.DependentTy;
else {
// FIXME: We don't allow folding in C++11 mode for an enum with a fixed
// underlying type, but do allow it in all other contexts.
if (getLangOpts().CPlusPlus11 && Enum->isFixed()) {
// C++11 [dcl.enum]p5: If the underlying type is fixed, [...] the
// constant-expression in the enumerator-definition shall be a converted
// constant expression of the underlying type.
EltTy = Enum->getIntegerType();
ExprResult Converted = CheckConvertedConstantExpression(
Val, EltTy, EnumVal, CCEKind::Enumerator);
if (Converted.isInvalid())
Val = nullptr;
else
Val = Converted.get();
} else if (!Val->isValueDependent() &&
!(Val = VerifyIntegerConstantExpression(Val, &EnumVal,
AllowFoldKind::Allow)
.get())) {
// C99 6.7.2.2p2: Make sure we have an integer constant expression.
} else {
if (Enum->isComplete()) {
EltTy = Enum->getIntegerType();
// In Obj-C and Microsoft mode, require the enumeration value to be
// representable in the underlying type of the enumeration. In C++11,
// we perform a non-narrowing conversion as part of converted constant
// expression checking.
if (!Context.isRepresentableIntegerValue(EnumVal, EltTy)) {
if (Context.getTargetInfo()
.getTriple()
.isWindowsMSVCEnvironment()) {
Diag(IdLoc, diag::ext_enumerator_too_large) << EltTy;
} else {
Diag(IdLoc, diag::err_enumerator_too_large) << EltTy;
}
}
// Cast to the underlying type.
Val = ImpCastExprToType(Val, EltTy,
EltTy->isBooleanType() ? CK_IntegralToBoolean
: CK_IntegralCast)
.get();
} else if (getLangOpts().CPlusPlus) {
// C++11 [dcl.enum]p5:
// If the underlying type is not fixed, the type of each enumerator
// is the type of its initializing value:
// - If an initializer is specified for an enumerator, the
// initializing value has the same type as the expression.
EltTy = Val->getType();
} else {
// C99 6.7.2.2p2:
// The expression that defines the value of an enumeration constant
// shall be an integer constant expression that has a value
// representable as an int.
// Complain if the value is not representable in an int.
if (!Context.isRepresentableIntegerValue(EnumVal, Context.IntTy)) {
Diag(IdLoc, getLangOpts().C23
? diag::warn_c17_compat_enum_value_not_int
: diag::ext_c23_enum_value_not_int)
<< 0 << toString(EnumVal, 10) << Val->getSourceRange()
<< (EnumVal.isUnsigned() || EnumVal.isNonNegative());
} else if (!Context.hasSameType(Val->getType(), Context.IntTy)) {
// Force the type of the expression to 'int'.
Val = ImpCastExprToType(Val, Context.IntTy, CK_IntegralCast).get();
}
EltTy = Val->getType();
}
}
}
}
if (!Val) {
if (Enum->isDependentType())
EltTy = Context.DependentTy;
else if (!LastEnumConst) {
// C++0x [dcl.enum]p5:
// If the underlying type is not fixed, the type of each enumerator
// is the type of its initializing value:
// - If no initializer is specified for the first enumerator, the
// initializing value has an unspecified integral type.
//
// GCC uses 'int' for its unspecified integral type, as does
// C99 6.7.2.2p3.
if (Enum->isFixed()) {
EltTy = Enum->getIntegerType();
}
else {
EltTy = Context.IntTy;
}
} else {
// Assign the last value + 1.
EnumVal = LastEnumConst->getInitVal();
++EnumVal;
EltTy = LastEnumConst->getType();
// Check for overflow on increment.
if (EnumVal < LastEnumConst->getInitVal()) {
// C++0x [dcl.enum]p5:
// If the underlying type is not fixed, the type of each enumerator
// is the type of its initializing value:
//
// - Otherwise the type of the initializing value is the same as
// the type of the initializing value of the preceding enumerator
// unless the incremented value is not representable in that type,
// in which case the type is an unspecified integral type
// sufficient to contain the incremented value. If no such type
// exists, the program is ill-formed.
QualType T = getNextLargerIntegralType(Context, EltTy);
if (T.isNull() || Enum->isFixed()) {
// There is no integral type larger enough to represent this
// value. Complain, then allow the value to wrap around.
EnumVal = LastEnumConst->getInitVal();
EnumVal = EnumVal.zext(EnumVal.getBitWidth() * 2);
++EnumVal;
if (Enum->isFixed())
// When the underlying type is fixed, this is ill-formed.
Diag(IdLoc, diag::err_enumerator_wrapped)
<< toString(EnumVal, 10)
<< EltTy;
else
Diag(IdLoc, diag::ext_enumerator_increment_too_large)
<< toString(EnumVal, 10);
} else {
EltTy = T;
}
// Retrieve the last enumerator's value, extent that type to the
// type that is supposed to be large enough to represent the incremented
// value, then increment.
EnumVal = LastEnumConst->getInitVal();
EnumVal.setIsSigned(EltTy->isSignedIntegerOrEnumerationType());
EnumVal = EnumVal.zextOrTrunc(Context.getIntWidth(EltTy));
++EnumVal;
// If we're not in C++, diagnose the overflow of enumerator values,
// which in C99 means that the enumerator value is not representable in
// an int (C99 6.7.2.2p2). However C23 permits enumerator values that
// are representable in some larger integral type and we allow it in
// older language modes as an extension.
// Exclude fixed enumerators since they are diagnosed with an error for
// this case.
if (!getLangOpts().CPlusPlus && !T.isNull() && !Enum->isFixed())
Diag(IdLoc, getLangOpts().C23
? diag::warn_c17_compat_enum_value_not_int
: diag::ext_c23_enum_value_not_int)
<< 1 << toString(EnumVal, 10) << 1;
} else if (!getLangOpts().CPlusPlus && !EltTy->isDependentType() &&
!Context.isRepresentableIntegerValue(EnumVal, EltTy)) {
// Enforce C99 6.7.2.2p2 even when we compute the next value.
Diag(IdLoc, getLangOpts().C23 ? diag::warn_c17_compat_enum_value_not_int
: diag::ext_c23_enum_value_not_int)
<< 1 << toString(EnumVal, 10) << 1;
}
}
}
if (!EltTy->isDependentType()) {
// Make the enumerator value match the signedness and size of the
// enumerator's type.
EnumVal = EnumVal.extOrTrunc(Context.getIntWidth(EltTy));
EnumVal.setIsSigned(EltTy->isSignedIntegerOrEnumerationType());
}
return EnumConstantDecl::Create(Context, Enum, IdLoc, Id, EltTy,
Val, EnumVal);
}
SkipBodyInfo Sema::shouldSkipAnonEnumBody(Scope *S, IdentifierInfo *II,
SourceLocation IILoc) {
if (!(getLangOpts().Modules || getLangOpts().ModulesLocalVisibility) ||
!getLangOpts().CPlusPlus)
return SkipBodyInfo();
// We have an anonymous enum definition. Look up the first enumerator to
// determine if we should merge the definition with an existing one and
// skip the body.
NamedDecl *PrevDecl = LookupSingleName(S, II, IILoc, LookupOrdinaryName,
forRedeclarationInCurContext());
auto *PrevECD = dyn_cast_or_null<EnumConstantDecl>(PrevDecl);
if (!PrevECD)
return SkipBodyInfo();
EnumDecl *PrevED = cast<EnumDecl>(PrevECD->getDeclContext());
NamedDecl *Hidden;
if (!PrevED->getDeclName() && !hasVisibleDefinition(PrevED, &Hidden)) {
SkipBodyInfo Skip;
Skip.Previous = Hidden;
return Skip;
}
return SkipBodyInfo();
}
Decl *Sema::ActOnEnumConstant(Scope *S, Decl *theEnumDecl, Decl *lastEnumConst,
SourceLocation IdLoc, IdentifierInfo *Id,
const ParsedAttributesView &Attrs,
SourceLocation EqualLoc, Expr *Val,
SkipBodyInfo *SkipBody) {
EnumDecl *TheEnumDecl = cast<EnumDecl>(theEnumDecl);
EnumConstantDecl *LastEnumConst =
cast_or_null<EnumConstantDecl>(lastEnumConst);
// The scope passed in may not be a decl scope. Zip up the scope tree until
// we find one that is.
S = getNonFieldDeclScope(S);
// Verify that there isn't already something declared with this name in this
// scope.
LookupResult R(*this, Id, IdLoc, LookupOrdinaryName,
RedeclarationKind::ForVisibleRedeclaration);
LookupName(R, S);
NamedDecl *PrevDecl = R.getAsSingle<NamedDecl>();
if (PrevDecl && PrevDecl->isTemplateParameter()) {
// Maybe we will complain about the shadowed template parameter.
DiagnoseTemplateParameterShadow(IdLoc, PrevDecl);
// Just pretend that we didn't see the previous declaration.
PrevDecl = nullptr;
}
// C++ [class.mem]p15:
// If T is the name of a class, then each of the following shall have a name
// different from T:
// - every enumerator of every member of class T that is an unscoped
// enumerated type
if (getLangOpts().CPlusPlus && !TheEnumDecl->isScoped() &&
DiagnoseClassNameShadow(TheEnumDecl->getDeclContext(),
DeclarationNameInfo(Id, IdLoc)))
return nullptr;
EnumConstantDecl *New =
CheckEnumConstant(TheEnumDecl, LastEnumConst, IdLoc, Id, Val);
if (!New)
return nullptr;
if (PrevDecl && (!SkipBody || !SkipBody->CheckSameAsPrevious)) {
if (!TheEnumDecl->isScoped() && isa<ValueDecl>(PrevDecl)) {
// Check for other kinds of shadowing not already handled.
CheckShadow(New, PrevDecl, R);
}
// When in C++, we may get a TagDecl with the same name; in this case the
// enum constant will 'hide' the tag.
assert((getLangOpts().CPlusPlus || !isa<TagDecl>(PrevDecl)) &&
"Received TagDecl when not in C++!");
if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) {
if (isa<EnumConstantDecl>(PrevDecl))
Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id;
else
Diag(IdLoc, diag::err_redefinition) << Id;
notePreviousDefinition(PrevDecl, IdLoc);
return nullptr;
}
}
// Process attributes.
ProcessDeclAttributeList(S, New, Attrs);
AddPragmaAttributes(S, New);
ProcessAPINotes(New);
// Register this decl in the current scope stack.
New->setAccess(TheEnumDecl->getAccess());
PushOnScopeChains(New, S);
ActOnDocumentableDecl(New);
return New;
}
// Returns true when the enum initial expression does not trigger the
// duplicate enum warning. A few common cases are exempted as follows:
// Element2 = Element1
// Element2 = Element1 + 1
// Element2 = Element1 - 1
// Where Element2 and Element1 are from the same enum.
static bool ValidDuplicateEnum(EnumConstantDecl *ECD, EnumDecl *Enum) {
Expr *InitExpr = ECD->getInitExpr();
if (!InitExpr)
return true;
InitExpr = InitExpr->IgnoreImpCasts();
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(InitExpr)) {
if (!BO->isAdditiveOp())
return true;
IntegerLiteral *IL = dyn_cast<IntegerLiteral>(BO->getRHS());
if (!IL)
return true;
if (IL->getValue() != 1)
return true;
InitExpr = BO->getLHS();
}
// This checks if the elements are from the same enum.
DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(InitExpr);
if (!DRE)
return true;
EnumConstantDecl *EnumConstant = dyn_cast<EnumConstantDecl>(DRE->getDecl());
if (!EnumConstant)
return true;
if (cast<EnumDecl>(TagDecl::castFromDeclContext(ECD->getDeclContext())) !=
Enum)
return true;
return false;
}
// Emits a warning when an element is implicitly set a value that
// a previous element has already been set to.
static void CheckForDuplicateEnumValues(Sema &S, ArrayRef<Decl *> Elements,
EnumDecl *Enum, QualType EnumType) {
// Avoid anonymous enums
if (!Enum->getIdentifier())
return;
// Only check for small enums.
if (Enum->getNumPositiveBits() > 63 || Enum->getNumNegativeBits() > 64)
return;
if (S.Diags.isIgnored(diag::warn_duplicate_enum_values, Enum->getLocation()))
return;
typedef SmallVector<EnumConstantDecl *, 3> ECDVector;
typedef SmallVector<std::unique_ptr<ECDVector>, 3> DuplicatesVector;
typedef llvm::PointerUnion<EnumConstantDecl*, ECDVector*> DeclOrVector;
// DenseMaps cannot contain the all ones int64_t value, so use unordered_map.
typedef std::unordered_map<int64_t, DeclOrVector> ValueToVectorMap;
// Use int64_t as a key to avoid needing special handling for map keys.
auto EnumConstantToKey = [](const EnumConstantDecl *D) {
llvm::APSInt Val = D->getInitVal();
return Val.isSigned() ? Val.getSExtValue() : Val.getZExtValue();
};
DuplicatesVector DupVector;
ValueToVectorMap EnumMap;
// Populate the EnumMap with all values represented by enum constants without
// an initializer.
for (auto *Element : Elements) {
EnumConstantDecl *ECD = cast_or_null<EnumConstantDecl>(Element);
// Null EnumConstantDecl means a previous diagnostic has been emitted for
// this constant. Skip this enum since it may be ill-formed.
if (!ECD) {
return;
}
// Constants with initializers are handled in the next loop.
if (ECD->getInitExpr())
continue;
// Duplicate values are handled in the next loop.
EnumMap.insert({EnumConstantToKey(ECD), ECD});
}
if (EnumMap.size() == 0)
return;
// Create vectors for any values that has duplicates.
for (auto *Element : Elements) {
// The last loop returned if any constant was null.
EnumConstantDecl *ECD = cast<EnumConstantDecl>(Element);
if (!ValidDuplicateEnum(ECD, Enum))
continue;
auto Iter = EnumMap.find(EnumConstantToKey(ECD));
if (Iter == EnumMap.end())
continue;
DeclOrVector& Entry = Iter->second;
if (EnumConstantDecl *D = dyn_cast<EnumConstantDecl *>(Entry)) {
// Ensure constants are different.
if (D == ECD)
continue;
// Create new vector and push values onto it.
auto Vec = std::make_unique<ECDVector>();
Vec->push_back(D);
Vec->push_back(ECD);
// Update entry to point to the duplicates vector.
Entry = Vec.get();
// Store the vector somewhere we can consult later for quick emission of
// diagnostics.
DupVector.emplace_back(std::move(Vec));
continue;
}
ECDVector *Vec = cast<ECDVector *>(Entry);
// Make sure constants are not added more than once.
if (*Vec->begin() == ECD)
continue;
Vec->push_back(ECD);
}
// Emit diagnostics.
for (const auto &Vec : DupVector) {
assert(Vec->size() > 1 && "ECDVector should have at least 2 elements.");
// Emit warning for one enum constant.
auto *FirstECD = Vec->front();
S.Diag(FirstECD->getLocation(), diag::warn_duplicate_enum_values)
<< FirstECD << toString(FirstECD->getInitVal(), 10)
<< FirstECD->getSourceRange();
// Emit one note for each of the remaining enum constants with
// the same value.
for (auto *ECD : llvm::drop_begin(*Vec))
S.Diag(ECD->getLocation(), diag::note_duplicate_element)
<< ECD << toString(ECD->getInitVal(), 10)
<< ECD->getSourceRange();
}
}
bool Sema::IsValueInFlagEnum(const EnumDecl *ED, const llvm::APInt &Val,
bool AllowMask) const {
assert(ED->isClosedFlag() && "looking for value in non-flag or open enum");
assert(ED->isCompleteDefinition() && "expected enum definition");
auto R = FlagBitsCache.try_emplace(ED);
llvm::APInt &FlagBits = R.first->second;
if (R.second) {
for (auto *E : ED->enumerators()) {
const auto &EVal = E->getInitVal();
// Only single-bit enumerators introduce new flag values.
if (EVal.isPowerOf2())
FlagBits = FlagBits.zext(EVal.getBitWidth()) | EVal;
}
}
// A value is in a flag enum if either its bits are a subset of the enum's
// flag bits (the first condition) or we are allowing masks and the same is
// true of its complement (the second condition). When masks are allowed, we
// allow the common idiom of ~(enum1 | enum2) to be a valid enum value.
//
// While it's true that any value could be used as a mask, the assumption is
// that a mask will have all of the insignificant bits set. Anything else is
// likely a logic error.
llvm::APInt FlagMask = ~FlagBits.zextOrTrunc(Val.getBitWidth());
return !(FlagMask & Val) || (AllowMask && !(FlagMask & ~Val));
}
void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange,
Decl *EnumDeclX, ArrayRef<Decl *> Elements, Scope *S,
const ParsedAttributesView &Attrs) {
EnumDecl *Enum = cast<EnumDecl>(EnumDeclX);
CanQualType EnumType = Context.getCanonicalTagType(Enum);
ProcessDeclAttributeList(S, Enum, Attrs);
ProcessAPINotes(Enum);
if (Enum->isDependentType()) {
for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
EnumConstantDecl *ECD =
cast_or_null<EnumConstantDecl>(Elements[i]);
if (!ECD) continue;
ECD->setType(EnumType);
}
Enum->completeDefinition(Context.DependentTy, Context.DependentTy, 0, 0);
return;
}
// Verify that all the values are okay, compute the size of the values, and
// reverse the list.
unsigned NumNegativeBits = 0;
unsigned NumPositiveBits = 0;
bool MembersRepresentableByInt =
Context.computeEnumBits(Elements, NumNegativeBits, NumPositiveBits);
// Figure out the type that should be used for this enum.
QualType BestType;
unsigned BestWidth;
// C++0x N3000 [conv.prom]p3:
// An rvalue of an unscoped enumeration type whose underlying
// type is not fixed can be converted to an rvalue of the first
// of the following types that can represent all the values of
// the enumeration: int, unsigned int, long int, unsigned long
// int, long long int, or unsigned long long int.
// C99 6.4.4.3p2:
// An identifier declared as an enumeration constant has type int.
// The C99 rule is modified by C23.
QualType BestPromotionType;
bool Packed = Enum->hasAttr<PackedAttr>();
// -fshort-enums is the equivalent to specifying the packed attribute on all
// enum definitions.
if (LangOpts.ShortEnums)
Packed = true;
// If the enum already has a type because it is fixed or dictated by the
// target, promote that type instead of analyzing the enumerators.
if (Enum->isComplete()) {
BestType = Enum->getIntegerType();
if (Context.isPromotableIntegerType(BestType))
BestPromotionType = Context.getPromotedIntegerType(BestType);
else
BestPromotionType = BestType;
BestWidth = Context.getIntWidth(BestType);
} else {
bool EnumTooLarge = Context.computeBestEnumTypes(
Packed, NumNegativeBits, NumPositiveBits, BestType, BestPromotionType);
BestWidth = Context.getIntWidth(BestType);
if (EnumTooLarge)
Diag(Enum->getLocation(), diag::ext_enum_too_large);
}
// Loop over all of the enumerator constants, changing their types to match
// the type of the enum if needed.
for (auto *D : Elements) {
auto *ECD = cast_or_null<EnumConstantDecl>(D);
if (!ECD) continue; // Already issued a diagnostic.
// C99 says the enumerators have int type, but we allow, as an
// extension, the enumerators to be larger than int size. If each
// enumerator value fits in an int, type it as an int, otherwise type it the
// same as the enumerator decl itself. This means that in "enum { X = 1U }"
// that X has type 'int', not 'unsigned'.
// Determine whether the value fits into an int.
llvm::APSInt InitVal = ECD->getInitVal();
// If it fits into an integer type, force it. Otherwise force it to match
// the enum decl type.
QualType NewTy;
unsigned NewWidth;
bool NewSign;
if (!getLangOpts().CPlusPlus && !Enum->isFixed() &&
MembersRepresentableByInt) {
// C23 6.7.3.3.3p15:
// The enumeration member type for an enumerated type without fixed
// underlying type upon completion is:
// - int if all the values of the enumeration are representable as an
// int; or,
// - the enumerated type
NewTy = Context.IntTy;
NewWidth = Context.getTargetInfo().getIntWidth();
NewSign = true;
} else if (ECD->getType() == BestType) {
// Already the right type!
if (getLangOpts().CPlusPlus)
// C++ [dcl.enum]p4: Following the closing brace of an
// enum-specifier, each enumerator has the type of its
// enumeration.
ECD->setType(EnumType);
continue;
} else {
NewTy = BestType;
NewWidth = BestWidth;
NewSign = BestType->isSignedIntegerOrEnumerationType();
}
// Adjust the APSInt value.
InitVal = InitVal.extOrTrunc(NewWidth);
InitVal.setIsSigned(NewSign);
ECD->setInitVal(Context, InitVal);
// Adjust the Expr initializer and type.
if (ECD->getInitExpr() &&
!Context.hasSameType(NewTy, ECD->getInitExpr()->getType()))
ECD->setInitExpr(ImplicitCastExpr::Create(
Context, NewTy, CK_IntegralCast, ECD->getInitExpr(),
/*base paths*/ nullptr, VK_PRValue, FPOptionsOverride()));
if (getLangOpts().CPlusPlus)
// C++ [dcl.enum]p4: Following the closing brace of an
// enum-specifier, each enumerator has the type of its
// enumeration.
ECD->setType(EnumType);
else
ECD->setType(NewTy);
}
Enum->completeDefinition(BestType, BestPromotionType,
NumPositiveBits, NumNegativeBits);
CheckForDuplicateEnumValues(*this, Elements, Enum, EnumType);
if (Enum->isClosedFlag()) {
for (Decl *D : Elements) {
EnumConstantDecl *ECD = cast_or_null<EnumConstantDecl>(D);
if (!ECD) continue; // Already issued a diagnostic.
llvm::APSInt InitVal = ECD->getInitVal();
if (InitVal != 0 && !InitVal.isPowerOf2() &&
!IsValueInFlagEnum(Enum, InitVal, true))
Diag(ECD->getLocation(), diag::warn_flag_enum_constant_out_of_range)
<< ECD << Enum;
}
}
// Now that the enum type is defined, ensure it's not been underaligned.
if (Enum->hasAttrs())
CheckAlignasUnderalignment(Enum);
}
Decl *Sema::ActOnFileScopeAsmDecl(Expr *expr, SourceLocation StartLoc,
SourceLocation EndLoc) {
FileScopeAsmDecl *New =
FileScopeAsmDecl::Create(Context, CurContext, expr, StartLoc, EndLoc);
CurContext->addDecl(New);
return New;
}
TopLevelStmtDecl *Sema::ActOnStartTopLevelStmtDecl(Scope *S) {
auto *New = TopLevelStmtDecl::Create(Context, /*Statement=*/nullptr);
CurContext->addDecl(New);
PushDeclContext(S, New);
PushFunctionScope();
PushCompoundScope(false);
return New;
}
void Sema::ActOnFinishTopLevelStmtDecl(TopLevelStmtDecl *D, Stmt *Statement) {
if (Statement)
D->setStmt(Statement);
PopCompoundScope();
PopFunctionScopeInfo();
PopDeclContext();
}
void Sema::ActOnPragmaRedefineExtname(IdentifierInfo* Name,
IdentifierInfo* AliasName,
SourceLocation PragmaLoc,
SourceLocation NameLoc,
SourceLocation AliasNameLoc) {
NamedDecl *PrevDecl = LookupSingleName(TUScope, Name, NameLoc,
LookupOrdinaryName);
AttributeCommonInfo Info(AliasName, SourceRange(AliasNameLoc),
AttributeCommonInfo::Form::Pragma());
AsmLabelAttr *Attr =
AsmLabelAttr::CreateImplicit(Context, AliasName->getName(), Info);
// If a declaration that:
// 1) declares a function or a variable
// 2) has external linkage
// already exists, add a label attribute to it.
if (PrevDecl && (isa<FunctionDecl>(PrevDecl) || isa<VarDecl>(PrevDecl))) {
if (isDeclExternC(PrevDecl))
PrevDecl->addAttr(Attr);
else
Diag(PrevDecl->getLocation(), diag::warn_redefine_extname_not_applied)
<< /*Variable*/(isa<FunctionDecl>(PrevDecl) ? 0 : 1) << PrevDecl;
// Otherwise, add a label attribute to ExtnameUndeclaredIdentifiers.
} else
(void)ExtnameUndeclaredIdentifiers.insert(std::make_pair(Name, Attr));
}
void Sema::ActOnPragmaWeakID(IdentifierInfo* Name,
SourceLocation PragmaLoc,
SourceLocation NameLoc) {
Decl *PrevDecl = LookupSingleName(TUScope, Name, NameLoc, LookupOrdinaryName);
if (PrevDecl) {
PrevDecl->addAttr(WeakAttr::CreateImplicit(Context, PragmaLoc));
} else {
(void)WeakUndeclaredIdentifiers[Name].insert(WeakInfo(nullptr, NameLoc));
}
}
void Sema::ActOnPragmaWeakAlias(IdentifierInfo* Name,
IdentifierInfo* AliasName,
SourceLocation PragmaLoc,
SourceLocation NameLoc,
SourceLocation AliasNameLoc) {
Decl *PrevDecl = LookupSingleName(TUScope, AliasName, AliasNameLoc,
LookupOrdinaryName);
WeakInfo W = WeakInfo(Name, NameLoc);
if (PrevDecl && (isa<FunctionDecl>(PrevDecl) || isa<VarDecl>(PrevDecl))) {
if (!PrevDecl->hasAttr<AliasAttr>())
if (NamedDecl *ND = dyn_cast<NamedDecl>(PrevDecl))
DeclApplyPragmaWeak(TUScope, ND, W);
} else {
(void)WeakUndeclaredIdentifiers[AliasName].insert(W);
}
}
Sema::FunctionEmissionStatus Sema::getEmissionStatus(const FunctionDecl *FD,
bool Final) {
assert(FD && "Expected non-null FunctionDecl");
// SYCL functions can be template, so we check if they have appropriate
// attribute prior to checking if it is a template.
if (LangOpts.SYCLIsDevice && FD->hasAttr<DeviceKernelAttr>())
return FunctionEmissionStatus::Emitted;
// Templates are emitted when they're instantiated.
if (FD->isDependentContext())
return FunctionEmissionStatus::TemplateDiscarded;
// Check whether this function is an externally visible definition.
auto IsEmittedForExternalSymbol = [this, FD]() {
// We have to check the GVA linkage of the function's *definition* -- if we
// only have a declaration, we don't know whether or not the function will
// be emitted, because (say) the definition could include "inline".
const FunctionDecl *Def = FD->getDefinition();
// We can't compute linkage when we skip function bodies.
return Def && !Def->hasSkippedBody() &&
!isDiscardableGVALinkage(
getASTContext().GetGVALinkageForFunction(Def));
};
if (LangOpts.OpenMPIsTargetDevice) {
// In OpenMP device mode we will not emit host only functions, or functions
// we don't need due to their linkage.
std::optional<OMPDeclareTargetDeclAttr::DevTypeTy> DevTy =
OMPDeclareTargetDeclAttr::getDeviceType(FD->getCanonicalDecl());
// DevTy may be changed later by
// #pragma omp declare target to(*) device_type(*).
// Therefore DevTy having no value does not imply host. The emission status
// will be checked again at the end of compilation unit with Final = true.
if (DevTy)
if (*DevTy == OMPDeclareTargetDeclAttr::DT_Host)
return FunctionEmissionStatus::OMPDiscarded;
// If we have an explicit value for the device type, or we are in a target
// declare context, we need to emit all extern and used symbols.
if (OpenMP().isInOpenMPDeclareTargetContext() || DevTy)
if (IsEmittedForExternalSymbol())
return FunctionEmissionStatus::Emitted;
// Device mode only emits what it must, if it wasn't tagged yet and needed,
// we'll omit it.
if (Final)
return FunctionEmissionStatus::OMPDiscarded;
} else if (LangOpts.OpenMP > 45) {
// In OpenMP host compilation prior to 5.0 everything was an emitted host
// function. In 5.0, no_host was introduced which might cause a function to
// be omitted.
std::optional<OMPDeclareTargetDeclAttr::DevTypeTy> DevTy =
OMPDeclareTargetDeclAttr::getDeviceType(FD->getCanonicalDecl());
if (DevTy)
if (*DevTy == OMPDeclareTargetDeclAttr::DT_NoHost)
return FunctionEmissionStatus::OMPDiscarded;
}
if (Final && LangOpts.OpenMP && !LangOpts.CUDA)
return FunctionEmissionStatus::Emitted;
if (LangOpts.CUDA) {
// When compiling for device, host functions are never emitted. Similarly,
// when compiling for host, device and global functions are never emitted.
// (Technically, we do emit a host-side stub for global functions, but this
// doesn't count for our purposes here.)
CUDAFunctionTarget T = CUDA().IdentifyTarget(FD);
if (LangOpts.CUDAIsDevice && T == CUDAFunctionTarget::Host)
return FunctionEmissionStatus::CUDADiscarded;
if (!LangOpts.CUDAIsDevice &&
(T == CUDAFunctionTarget::Device || T == CUDAFunctionTarget::Global))
return FunctionEmissionStatus::CUDADiscarded;
if (IsEmittedForExternalSymbol())
return FunctionEmissionStatus::Emitted;
// If FD is a virtual destructor of an explicit instantiation
// of a template class, return Emitted.
if (auto *Destructor = dyn_cast<CXXDestructorDecl>(FD)) {
if (Destructor->isVirtual()) {
if (auto *Spec = dyn_cast<ClassTemplateSpecializationDecl>(
Destructor->getParent())) {
TemplateSpecializationKind TSK =
Spec->getTemplateSpecializationKind();
if (TSK == TSK_ExplicitInstantiationDeclaration ||
TSK == TSK_ExplicitInstantiationDefinition)
return FunctionEmissionStatus::Emitted;
}
}
}
}
// Otherwise, the function is known-emitted if it's in our set of
// known-emitted functions.
return FunctionEmissionStatus::Unknown;
}
bool Sema::shouldIgnoreInHostDeviceCheck(FunctionDecl *Callee) {
// Host-side references to a __global__ function refer to the stub, so the
// function itself is never emitted and therefore should not be marked.
// If we have host fn calls kernel fn calls host+device, the HD function
// does not get instantiated on the host. We model this by omitting at the
// call to the kernel from the callgraph. This ensures that, when compiling
// for host, only HD functions actually called from the host get marked as
// known-emitted.
return LangOpts.CUDA && !LangOpts.CUDAIsDevice &&
CUDA().IdentifyTarget(Callee) == CUDAFunctionTarget::Global;
}
bool Sema::isRedefinitionAllowedFor(NamedDecl *D, NamedDecl **Suggested,
bool &Visible) {
Visible = hasVisibleDefinition(D, Suggested);
// The redefinition of D in the **current** TU is allowed if D is invisible or
// D is defined in the global module of other module units. We didn't check if
// it is in global module as, we'll check the redefinition in named module
// later with better diagnostic message.
return D->isInAnotherModuleUnit() || !Visible;
}