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llvm / llvm-project / 6e2aecd759dc3f8bf664323388365ac234271e9b / . / clang / lib / Sema / SemaDeclCXX.cpp
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//===------ SemaDeclCXX.cpp - Semantic Analysis for C++ 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 C++ declarations.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTLambda.h"
#include "clang/AST/ASTMutationListener.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/CharUnits.h"
#include "clang/AST/ComparisonCategories.h"
#include "clang/AST/EvaluatedExprVisitor.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/AST/TypeLoc.h"
#include "clang/AST/TypeOrdering.h"
#include "clang/Basic/AttributeCommonInfo.h"
#include "clang/Basic/PartialDiagnostic.h"
#include "clang/Basic/Specifiers.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Lex/LiteralSupport.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Sema/CXXFieldCollector.h"
#include "clang/Sema/DeclSpec.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/SemaInternal.h"
#include "clang/Sema/Template.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringExtras.h"
#include <map>
#include <set>
using namespace clang;
//===----------------------------------------------------------------------===//
// CheckDefaultArgumentVisitor
//===----------------------------------------------------------------------===//
namespace {
/// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
/// the default argument of a parameter to determine whether it
/// contains any ill-formed subexpressions. For example, this will
/// diagnose the use of local variables or parameters within the
/// default argument expression.
class CheckDefaultArgumentVisitor
: public ConstStmtVisitor<CheckDefaultArgumentVisitor, bool> {
Sema &S;
const Expr *DefaultArg;
public:
CheckDefaultArgumentVisitor(Sema &S, const Expr *DefaultArg)
: S(S), DefaultArg(DefaultArg) {}
bool VisitExpr(const Expr *Node);
bool VisitDeclRefExpr(const DeclRefExpr *DRE);
bool VisitCXXThisExpr(const CXXThisExpr *ThisE);
bool VisitLambdaExpr(const LambdaExpr *Lambda);
bool VisitPseudoObjectExpr(const PseudoObjectExpr *POE);
};
/// VisitExpr - Visit all of the children of this expression.
bool CheckDefaultArgumentVisitor::VisitExpr(const Expr *Node) {
bool IsInvalid = false;
for (const Stmt *SubStmt : Node->children())
IsInvalid |= Visit(SubStmt);
return IsInvalid;
}
/// VisitDeclRefExpr - Visit a reference to a declaration, to
/// determine whether this declaration can be used in the default
/// argument expression.
bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(const DeclRefExpr *DRE) {
const NamedDecl *Decl = DRE->getDecl();
if (const auto *Param = dyn_cast<ParmVarDecl>(Decl)) {
// C++ [dcl.fct.default]p9:
// [...] parameters of a function shall not be used in default
// argument expressions, even if they are not evaluated. [...]
//
// C++17 [dcl.fct.default]p9 (by CWG 2082):
// [...] A parameter shall not appear as a potentially-evaluated
// expression in a default argument. [...]
//
if (DRE->isNonOdrUse() != NOUR_Unevaluated)
return S.Diag(DRE->getBeginLoc(),
diag::err_param_default_argument_references_param)
<< Param->getDeclName() << DefaultArg->getSourceRange();
} else if (const auto *VDecl = dyn_cast<VarDecl>(Decl)) {
// C++ [dcl.fct.default]p7:
// Local variables shall not be used in default argument
// expressions.
//
// C++17 [dcl.fct.default]p7 (by CWG 2082):
// A local variable shall not appear as a potentially-evaluated
// expression in a default argument.
//
// C++20 [dcl.fct.default]p7 (DR as part of P0588R1, see also CWG 2346):
// Note: A local variable cannot be odr-used (6.3) in a default argument.
//
if (VDecl->isLocalVarDecl() && !DRE->isNonOdrUse())
return S.Diag(DRE->getBeginLoc(),
diag::err_param_default_argument_references_local)
<< VDecl->getDeclName() << DefaultArg->getSourceRange();
}
return false;
}
/// VisitCXXThisExpr - Visit a C++ "this" expression.
bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(const CXXThisExpr *ThisE) {
// C++ [dcl.fct.default]p8:
// The keyword this shall not be used in a default argument of a
// member function.
return S.Diag(ThisE->getBeginLoc(),
diag::err_param_default_argument_references_this)
<< ThisE->getSourceRange();
}
bool CheckDefaultArgumentVisitor::VisitPseudoObjectExpr(
const PseudoObjectExpr *POE) {
bool Invalid = false;
for (const Expr *E : POE->semantics()) {
// Look through bindings.
if (const auto *OVE = dyn_cast<OpaqueValueExpr>(E)) {
E = OVE->getSourceExpr();
assert(E && "pseudo-object binding without source expression?");
}
Invalid |= Visit(E);
}
return Invalid;
}
bool CheckDefaultArgumentVisitor::VisitLambdaExpr(const LambdaExpr *Lambda) {
// C++11 [expr.lambda.prim]p13:
// A lambda-expression appearing in a default argument shall not
// implicitly or explicitly capture any entity.
if (Lambda->capture_begin() == Lambda->capture_end())
return false;
return S.Diag(Lambda->getBeginLoc(), diag::err_lambda_capture_default_arg);
}
} // namespace
void
Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc,
const CXXMethodDecl *Method) {
// If we have an MSAny spec already, don't bother.
if (!Method || ComputedEST == EST_MSAny)
return;
const FunctionProtoType *Proto
= Method->getType()->getAs<FunctionProtoType>();
Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
if (!Proto)
return;
ExceptionSpecificationType EST = Proto->getExceptionSpecType();
// If we have a throw-all spec at this point, ignore the function.
if (ComputedEST == EST_None)
return;
if (EST == EST_None && Method->hasAttr<NoThrowAttr>())
EST = EST_BasicNoexcept;
switch (EST) {
case EST_Unparsed:
case EST_Uninstantiated:
case EST_Unevaluated:
llvm_unreachable("should not see unresolved exception specs here");
// If this function can throw any exceptions, make a note of that.
case EST_MSAny:
case EST_None:
// FIXME: Whichever we see last of MSAny and None determines our result.
// We should make a consistent, order-independent choice here.
ClearExceptions();
ComputedEST = EST;
return;
case EST_NoexceptFalse:
ClearExceptions();
ComputedEST = EST_None;
return;
// FIXME: If the call to this decl is using any of its default arguments, we
// need to search them for potentially-throwing calls.
// If this function has a basic noexcept, it doesn't affect the outcome.
case EST_BasicNoexcept:
case EST_NoexceptTrue:
case EST_NoThrow:
return;
// If we're still at noexcept(true) and there's a throw() callee,
// change to that specification.
case EST_DynamicNone:
if (ComputedEST == EST_BasicNoexcept)
ComputedEST = EST_DynamicNone;
return;
case EST_DependentNoexcept:
llvm_unreachable(
"should not generate implicit declarations for dependent cases");
case EST_Dynamic:
break;
}
assert(EST == EST_Dynamic && "EST case not considered earlier.");
assert(ComputedEST != EST_None &&
"Shouldn't collect exceptions when throw-all is guaranteed.");
ComputedEST = EST_Dynamic;
// Record the exceptions in this function's exception specification.
for (const auto &E : Proto->exceptions())
if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second)
Exceptions.push_back(E);
}
void Sema::ImplicitExceptionSpecification::CalledStmt(Stmt *S) {
if (!S || ComputedEST == EST_MSAny)
return;
// FIXME:
//
// C++0x [except.spec]p14:
// [An] implicit exception-specification specifies the type-id T if and
// only if T is allowed by the exception-specification of a function directly
// invoked by f's implicit definition; f shall allow all exceptions if any
// function it directly invokes allows all exceptions, and f shall allow no
// exceptions if every function it directly invokes allows no exceptions.
//
// Note in particular that if an implicit exception-specification is generated
// for a function containing a throw-expression, that specification can still
// be noexcept(true).
//
// Note also that 'directly invoked' is not defined in the standard, and there
// is no indication that we should only consider potentially-evaluated calls.
//
// Ultimately we should implement the intent of the standard: the exception
// specification should be the set of exceptions which can be thrown by the
// implicit definition. For now, we assume that any non-nothrow expression can
// throw any exception.
if (Self->canThrow(S))
ComputedEST = EST_None;
}
ExprResult Sema::ConvertParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
SourceLocation EqualLoc) {
if (RequireCompleteType(Param->getLocation(), Param->getType(),
diag::err_typecheck_decl_incomplete_type))
return true;
// C++ [dcl.fct.default]p5
// A default argument expression is implicitly converted (clause
// 4) to the parameter type. The default argument expression has
// the same semantic constraints as the initializer expression in
// a declaration of a variable of the parameter type, using the
// copy-initialization semantics (8.5).
InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
Param);
InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
EqualLoc);
InitializationSequence InitSeq(*this, Entity, Kind, Arg);
ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg);
if (Result.isInvalid())
return true;
Arg = Result.getAs<Expr>();
CheckCompletedExpr(Arg, EqualLoc);
Arg = MaybeCreateExprWithCleanups(Arg);
return Arg;
}
void Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
SourceLocation EqualLoc) {
// Add the default argument to the parameter
Param->setDefaultArg(Arg);
// We have already instantiated this parameter; provide each of the
// instantiations with the uninstantiated default argument.
UnparsedDefaultArgInstantiationsMap::iterator InstPos
= UnparsedDefaultArgInstantiations.find(Param);
if (InstPos != UnparsedDefaultArgInstantiations.end()) {
for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
// We're done tracking this parameter's instantiations.
UnparsedDefaultArgInstantiations.erase(InstPos);
}
}
/// ActOnParamDefaultArgument - Check whether the default argument
/// provided for a function parameter is well-formed. If so, attach it
/// to the parameter declaration.
void
Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc,
Expr *DefaultArg) {
if (!param || !DefaultArg)
return;
ParmVarDecl *Param = cast<ParmVarDecl>(param);
UnparsedDefaultArgLocs.erase(Param);
auto Fail = [&] {
Param->setInvalidDecl();
Param->setDefaultArg(new (Context) OpaqueValueExpr(
EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue));
};
// Default arguments are only permitted in C++
if (!getLangOpts().CPlusPlus) {
Diag(EqualLoc, diag::err_param_default_argument)
<< DefaultArg->getSourceRange();
return Fail();
}
// Check for unexpanded parameter packs.
if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
return Fail();
}
// C++11 [dcl.fct.default]p3
// A default argument expression [...] shall not be specified for a
// parameter pack.
if (Param->isParameterPack()) {
Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack)
<< DefaultArg->getSourceRange();
// Recover by discarding the default argument.
Param->setDefaultArg(nullptr);
return;
}
ExprResult Result = ConvertParamDefaultArgument(Param, DefaultArg, EqualLoc);
if (Result.isInvalid())
return Fail();
DefaultArg = Result.getAs<Expr>();
// Check that the default argument is well-formed
CheckDefaultArgumentVisitor DefaultArgChecker(*this, DefaultArg);
if (DefaultArgChecker.Visit(DefaultArg))
return Fail();
SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
}
/// ActOnParamUnparsedDefaultArgument - We've seen a default
/// argument for a function parameter, but we can't parse it yet
/// because we're inside a class definition. Note that this default
/// argument will be parsed later.
void Sema::ActOnParamUnparsedDefaultArgument(Decl *param,
SourceLocation EqualLoc,
SourceLocation ArgLoc) {
if (!param)
return;
ParmVarDecl *Param = cast<ParmVarDecl>(param);
Param->setUnparsedDefaultArg();
UnparsedDefaultArgLocs[Param] = ArgLoc;
}
/// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
/// the default argument for the parameter param failed.
void Sema::ActOnParamDefaultArgumentError(Decl *param,
SourceLocation EqualLoc) {
if (!param)
return;
ParmVarDecl *Param = cast<ParmVarDecl>(param);
Param->setInvalidDecl();
UnparsedDefaultArgLocs.erase(Param);
Param->setDefaultArg(new (Context) OpaqueValueExpr(
EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue));
}
/// CheckExtraCXXDefaultArguments - Check for any extra default
/// arguments in the declarator, which is not a function declaration
/// or definition and therefore is not permitted to have default
/// arguments. This routine should be invoked for every declarator
/// that is not a function declaration or definition.
void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
// C++ [dcl.fct.default]p3
// A default argument expression shall be specified only in the
// parameter-declaration-clause of a function declaration or in a
// template-parameter (14.1). It shall not be specified for a
// parameter pack. If it is specified in a
// parameter-declaration-clause, it shall not occur within a
// declarator or abstract-declarator of a parameter-declaration.
bool MightBeFunction = D.isFunctionDeclarationContext();
for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
DeclaratorChunk &chunk = D.getTypeObject(i);
if (chunk.Kind == DeclaratorChunk::Function) {
if (MightBeFunction) {
// This is a function declaration. It can have default arguments, but
// keep looking in case its return type is a function type with default
// arguments.
MightBeFunction = false;
continue;
}
for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e;
++argIdx) {
ParmVarDecl *Param = cast<ParmVarDecl>(chunk.Fun.Params[argIdx].Param);
if (Param->hasUnparsedDefaultArg()) {
std::unique_ptr<CachedTokens> Toks =
std::move(chunk.Fun.Params[argIdx].DefaultArgTokens);
SourceRange SR;
if (Toks->size() > 1)
SR = SourceRange((*Toks)[1].getLocation(),
Toks->back().getLocation());
else
SR = UnparsedDefaultArgLocs[Param];
Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
<< SR;
} else if (Param->getDefaultArg()) {
Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
<< Param->getDefaultArg()->getSourceRange();
Param->setDefaultArg(nullptr);
}
}
} else if (chunk.Kind != DeclaratorChunk::Paren) {
MightBeFunction = false;
}
}
}
static bool functionDeclHasDefaultArgument(const FunctionDecl *FD) {
return llvm::any_of(FD->parameters(), [](ParmVarDecl *P) {
return P->hasDefaultArg() && !P->hasInheritedDefaultArg();
});
}
/// MergeCXXFunctionDecl - Merge two declarations of the same C++
/// function, once we already know that they have the same
/// type. Subroutine of MergeFunctionDecl. Returns true if there was an
/// error, false otherwise.
bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old,
Scope *S) {
bool Invalid = false;
// The declaration context corresponding to the scope is the semantic
// parent, unless this is a local function declaration, in which case
// it is that surrounding function.
DeclContext *ScopeDC = New->isLocalExternDecl()
? New->getLexicalDeclContext()
: New->getDeclContext();
// Find the previous declaration for the purpose of default arguments.
FunctionDecl *PrevForDefaultArgs = Old;
for (/**/; PrevForDefaultArgs;
// Don't bother looking back past the latest decl if this is a local
// extern declaration; nothing else could work.
PrevForDefaultArgs = New->isLocalExternDecl()
? nullptr
: PrevForDefaultArgs->getPreviousDecl()) {
// Ignore hidden declarations.
if (!LookupResult::isVisible(*this, PrevForDefaultArgs))
continue;
if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) &&
!New->isCXXClassMember()) {
// Ignore default arguments of old decl if they are not in
// the same scope and this is not an out-of-line definition of
// a member function.
continue;
}
if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) {
// If only one of these is a local function declaration, then they are
// declared in different scopes, even though isDeclInScope may think
// they're in the same scope. (If both are local, the scope check is
// sufficient, and if neither is local, then they are in the same scope.)
continue;
}
// We found the right previous declaration.
break;
}
// C++ [dcl.fct.default]p4:
// For non-template functions, default arguments can be added in
// later declarations of a function in the same
// scope. Declarations in different scopes have completely
// distinct sets of default arguments. That is, declarations in
// inner scopes do not acquire default arguments from
// declarations in outer scopes, and vice versa. In a given
// function declaration, all parameters subsequent to a
// parameter with a default argument shall have default
// arguments supplied in this or previous declarations. A
// default argument shall not be redefined by a later
// declaration (not even to the same value).
//
// C++ [dcl.fct.default]p6:
// Except for member functions of class templates, the default arguments
// in a member function definition that appears outside of the class
// definition are added to the set of default arguments provided by the
// member function declaration in the class definition.
for (unsigned p = 0, NumParams = PrevForDefaultArgs
? PrevForDefaultArgs->getNumParams()
: 0;
p < NumParams; ++p) {
ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p);
ParmVarDecl *NewParam = New->getParamDecl(p);
bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false;
bool NewParamHasDfl = NewParam->hasDefaultArg();
if (OldParamHasDfl && NewParamHasDfl) {
unsigned DiagDefaultParamID =
diag::err_param_default_argument_redefinition;
// MSVC accepts that default parameters be redefined for member functions
// of template class. The new default parameter's value is ignored.
Invalid = true;
if (getLangOpts().MicrosoftExt) {
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(New);
if (MD && MD->getParent()->getDescribedClassTemplate()) {
// Merge the old default argument into the new parameter.
NewParam->setHasInheritedDefaultArg();
if (OldParam->hasUninstantiatedDefaultArg())
NewParam->setUninstantiatedDefaultArg(
OldParam->getUninstantiatedDefaultArg());
else
NewParam->setDefaultArg(OldParam->getInit());
DiagDefaultParamID = diag::ext_param_default_argument_redefinition;
Invalid = false;
}
}
// FIXME: If we knew where the '=' was, we could easily provide a fix-it
// hint here. Alternatively, we could walk the type-source information
// for NewParam to find the last source location in the type... but it
// isn't worth the effort right now. This is the kind of test case that
// is hard to get right:
// int f(int);
// void g(int (*fp)(int) = f);
// void g(int (*fp)(int) = &f);
Diag(NewParam->getLocation(), DiagDefaultParamID)
<< NewParam->getDefaultArgRange();
// Look for the function declaration where the default argument was
// actually written, which may be a declaration prior to Old.
for (auto Older = PrevForDefaultArgs;
OldParam->hasInheritedDefaultArg(); /**/) {
Older = Older->getPreviousDecl();
OldParam = Older->getParamDecl(p);
}
Diag(OldParam->getLocation(), diag::note_previous_definition)
<< OldParam->getDefaultArgRange();
} else if (OldParamHasDfl) {
// Merge the old default argument into the new parameter unless the new
// function is a friend declaration in a template class. In the latter
// case the default arguments will be inherited when the friend
// declaration will be instantiated.
if (New->getFriendObjectKind() == Decl::FOK_None ||
!New->getLexicalDeclContext()->isDependentContext()) {
// It's important to use getInit() here; getDefaultArg()
// strips off any top-level ExprWithCleanups.
NewParam->setHasInheritedDefaultArg();
if (OldParam->hasUnparsedDefaultArg())
NewParam->setUnparsedDefaultArg();
else if (OldParam->hasUninstantiatedDefaultArg())
NewParam->setUninstantiatedDefaultArg(
OldParam->getUninstantiatedDefaultArg());
else
NewParam->setDefaultArg(OldParam->getInit());
}
} else if (NewParamHasDfl) {
if (New->getDescribedFunctionTemplate()) {
// Paragraph 4, quoted above, only applies to non-template functions.
Diag(NewParam->getLocation(),
diag::err_param_default_argument_template_redecl)
<< NewParam->getDefaultArgRange();
Diag(PrevForDefaultArgs->getLocation(),
diag::note_template_prev_declaration)
<< false;
} else if (New->getTemplateSpecializationKind()
!= TSK_ImplicitInstantiation &&
New->getTemplateSpecializationKind() != TSK_Undeclared) {
// C++ [temp.expr.spec]p21:
// Default function arguments shall not be specified in a declaration
// or a definition for one of the following explicit specializations:
// - the explicit specialization of a function template;
// - the explicit specialization of a member function template;
// - the explicit specialization of a member function of a class
// template where the class template specialization to which the
// member function specialization belongs is implicitly
// instantiated.
Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
<< (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
<< New->getDeclName()
<< NewParam->getDefaultArgRange();
} else if (New->getDeclContext()->isDependentContext()) {
// C++ [dcl.fct.default]p6 (DR217):
// Default arguments for a member function of a class template shall
// be specified on the initial declaration of the member function
// within the class template.
//
// Reading the tea leaves a bit in DR217 and its reference to DR205
// leads me to the conclusion that one cannot add default function
// arguments for an out-of-line definition of a member function of a
// dependent type.
int WhichKind = 2;
if (CXXRecordDecl *Record
= dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
if (Record->getDescribedClassTemplate())
WhichKind = 0;
else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
WhichKind = 1;
else
WhichKind = 2;
}
Diag(NewParam->getLocation(),
diag::err_param_default_argument_member_template_redecl)
<< WhichKind
<< NewParam->getDefaultArgRange();
}
}
}
// DR1344: If a default argument is added outside a class definition and that
// default argument makes the function a special member function, the program
// is ill-formed. This can only happen for constructors.
if (isa<CXXConstructorDecl>(New) &&
New->getMinRequiredArguments() < Old->getMinRequiredArguments()) {
CXXSpecialMember NewSM = getSpecialMember(cast<CXXMethodDecl>(New)),
OldSM = getSpecialMember(cast<CXXMethodDecl>(Old));
if (NewSM != OldSM) {
ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments());
assert(NewParam->hasDefaultArg());
Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special)
<< NewParam->getDefaultArgRange() << NewSM;
Diag(Old->getLocation(), diag::note_previous_declaration);
}
}
const FunctionDecl *Def;
// C++11 [dcl.constexpr]p1: If any declaration of a function or function
// template has a constexpr specifier then all its declarations shall
// contain the constexpr specifier.
if (New->getConstexprKind() != Old->getConstexprKind()) {
Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
<< New << static_cast<int>(New->getConstexprKind())
<< static_cast<int>(Old->getConstexprKind());
Diag(Old->getLocation(), diag::note_previous_declaration);
Invalid = true;
} else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() &&
Old->isDefined(Def) &&
// If a friend function is inlined but does not have 'inline'
// specifier, it is a definition. Do not report attribute conflict
// in this case, redefinition will be diagnosed later.
(New->isInlineSpecified() ||
New->getFriendObjectKind() == Decl::FOK_None)) {
// C++11 [dcl.fcn.spec]p4:
// If the definition of a function 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);
Invalid = true;
}
// C++17 [temp.deduct.guide]p3:
// Two deduction guide declarations in the same translation unit
// for the same class template shall not have equivalent
// parameter-declaration-clauses.
if (isa<CXXDeductionGuideDecl>(New) &&
!New->isFunctionTemplateSpecialization() && isVisible(Old)) {
Diag(New->getLocation(), diag::err_deduction_guide_redeclared);
Diag(Old->getLocation(), diag::note_previous_declaration);
}
// C++11 [dcl.fct.default]p4: If a friend declaration specifies a default
// argument expression, that declaration shall be a definition and shall be
// the only declaration of the function or function template in the
// translation unit.
if (Old->getFriendObjectKind() == Decl::FOK_Undeclared &&
functionDeclHasDefaultArgument(Old)) {
Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
Diag(Old->getLocation(), diag::note_previous_declaration);
Invalid = true;
}
// C++11 [temp.friend]p4 (DR329):
// When a function is defined in a friend function declaration in a class
// template, the function is instantiated when the function is odr-used.
// The same restrictions on multiple declarations and definitions that
// apply to non-template function declarations and definitions also apply
// to these implicit definitions.
const FunctionDecl *OldDefinition = nullptr;
if (New->isThisDeclarationInstantiatedFromAFriendDefinition() &&
Old->isDefined(OldDefinition, true))
CheckForFunctionRedefinition(New, OldDefinition);
return Invalid;
}
NamedDecl *
Sema::ActOnDecompositionDeclarator(Scope *S, Declarator &D,
MultiTemplateParamsArg TemplateParamLists) {
assert(D.isDecompositionDeclarator());
const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator();
// The syntax only allows a decomposition declarator as a simple-declaration,
// a for-range-declaration, or a condition in Clang, but we parse it in more
// cases than that.
if (!D.mayHaveDecompositionDeclarator()) {
Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
<< Decomp.getSourceRange();
return nullptr;
}
if (!TemplateParamLists.empty()) {
// FIXME: There's no rule against this, but there are also no rules that
// would actually make it usable, so we reject it for now.
Diag(TemplateParamLists.front()->getTemplateLoc(),
diag::err_decomp_decl_template);
return nullptr;
}
Diag(Decomp.getLSquareLoc(),
!getLangOpts().CPlusPlus17
? diag::ext_decomp_decl
: D.getContext() == DeclaratorContext::Condition
? diag::ext_decomp_decl_cond
: diag::warn_cxx14_compat_decomp_decl)
<< Decomp.getSourceRange();
// The semantic context is always just the current context.
DeclContext *const DC = CurContext;
// C++17 [dcl.dcl]/8:
// The decl-specifier-seq shall contain only the type-specifier auto
// and cv-qualifiers.
// C++2a [dcl.dcl]/8:
// If decl-specifier-seq contains any decl-specifier other than static,
// thread_local, auto, or cv-qualifiers, the program is ill-formed.
auto &DS = D.getDeclSpec();
{
SmallVector<StringRef, 8> BadSpecifiers;
SmallVector<SourceLocation, 8> BadSpecifierLocs;
SmallVector<StringRef, 8> CPlusPlus20Specifiers;
SmallVector<SourceLocation, 8> CPlusPlus20SpecifierLocs;
if (auto SCS = DS.getStorageClassSpec()) {
if (SCS == DeclSpec::SCS_static) {
CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(SCS));
CPlusPlus20SpecifierLocs.push_back(DS.getStorageClassSpecLoc());
} else {
BadSpecifiers.push_back(DeclSpec::getSpecifierName(SCS));
BadSpecifierLocs.push_back(DS.getStorageClassSpecLoc());
}
}
if (auto TSCS = DS.getThreadStorageClassSpec()) {
CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(TSCS));
CPlusPlus20SpecifierLocs.push_back(DS.getThreadStorageClassSpecLoc());
}
if (DS.hasConstexprSpecifier()) {
BadSpecifiers.push_back(
DeclSpec::getSpecifierName(DS.getConstexprSpecifier()));
BadSpecifierLocs.push_back(DS.getConstexprSpecLoc());
}
if (DS.isInlineSpecified()) {
BadSpecifiers.push_back("inline");
BadSpecifierLocs.push_back(DS.getInlineSpecLoc());
}
if (!BadSpecifiers.empty()) {
auto &&Err = Diag(BadSpecifierLocs.front(), diag::err_decomp_decl_spec);
Err << (int)BadSpecifiers.size()
<< llvm::join(BadSpecifiers.begin(), BadSpecifiers.end(), " ");
// Don't add FixItHints to remove the specifiers; we do still respect
// them when building the underlying variable.
for (auto Loc : BadSpecifierLocs)
Err << SourceRange(Loc, Loc);
} else if (!CPlusPlus20Specifiers.empty()) {
auto &&Warn = Diag(CPlusPlus20SpecifierLocs.front(),
getLangOpts().CPlusPlus20
? diag::warn_cxx17_compat_decomp_decl_spec
: diag::ext_decomp_decl_spec);
Warn << (int)CPlusPlus20Specifiers.size()
<< llvm::join(CPlusPlus20Specifiers.begin(),
CPlusPlus20Specifiers.end(), " ");
for (auto Loc : CPlusPlus20SpecifierLocs)
Warn << SourceRange(Loc, Loc);
}
// We can't recover from it being declared as a typedef.
if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
return nullptr;
}
// C++2a [dcl.struct.bind]p1:
// A cv that includes volatile is deprecated
if ((DS.getTypeQualifiers() & DeclSpec::TQ_volatile) &&
getLangOpts().CPlusPlus20)
Diag(DS.getVolatileSpecLoc(),
diag::warn_deprecated_volatile_structured_binding);
TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
QualType R = TInfo->getType();
if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
UPPC_DeclarationType))
D.setInvalidType();
// The syntax only allows a single ref-qualifier prior to the decomposition
// declarator. No other declarator chunks are permitted. Also check the type
// specifier here.
if (DS.getTypeSpecType() != DeclSpec::TST_auto ||
D.hasGroupingParens() || D.getNumTypeObjects() > 1 ||
(D.getNumTypeObjects() == 1 &&
D.getTypeObject(0).Kind != DeclaratorChunk::Reference)) {
Diag(Decomp.getLSquareLoc(),
(D.hasGroupingParens() ||
(D.getNumTypeObjects() &&
D.getTypeObject(0).Kind == DeclaratorChunk::Paren))
? diag::err_decomp_decl_parens
: diag::err_decomp_decl_type)
<< R;
// In most cases, there's no actual problem with an explicitly-specified
// type, but a function type won't work here, and ActOnVariableDeclarator
// shouldn't be called for such a type.
if (R->isFunctionType())
D.setInvalidType();
}
// Build the BindingDecls.
SmallVector<BindingDecl*, 8> Bindings;
// Build the BindingDecls.
for (auto &B : D.getDecompositionDeclarator().bindings()) {
// Check for name conflicts.
DeclarationNameInfo NameInfo(B.Name, B.NameLoc);
LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
ForVisibleRedeclaration);
LookupName(Previous, S,
/*CreateBuiltins*/DC->getRedeclContext()->isTranslationUnit());
// It's not permitted to shadow a template parameter name.
if (Previous.isSingleResult() &&
Previous.getFoundDecl()->isTemplateParameter()) {
DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
Previous.getFoundDecl());
Previous.clear();
}
auto *BD = BindingDecl::Create(Context, DC, B.NameLoc, B.Name);
// Find the shadowed declaration before filtering for scope.
NamedDecl *ShadowedDecl = D.getCXXScopeSpec().isEmpty()
? getShadowedDeclaration(BD, Previous)
: nullptr;
bool ConsiderLinkage = DC->isFunctionOrMethod() &&
DS.getStorageClassSpec() == DeclSpec::SCS_extern;
FilterLookupForScope(Previous, DC, S, ConsiderLinkage,
/*AllowInlineNamespace*/false);
if (!Previous.empty()) {
auto *Old = Previous.getRepresentativeDecl();
Diag(B.NameLoc, diag::err_redefinition) << B.Name;
Diag(Old->getLocation(), diag::note_previous_definition);
} else if (ShadowedDecl && !D.isRedeclaration()) {
CheckShadow(BD, ShadowedDecl, Previous);
}
PushOnScopeChains(BD, S, true);
Bindings.push_back(BD);
ParsingInitForAutoVars.insert(BD);
}
// There are no prior lookup results for the variable itself, because it
// is unnamed.
DeclarationNameInfo NameInfo((IdentifierInfo *)nullptr,
Decomp.getLSquareLoc());
LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
ForVisibleRedeclaration);
// Build the variable that holds the non-decomposed object.
bool AddToScope = true;
NamedDecl *New =
ActOnVariableDeclarator(S, D, DC, TInfo, Previous,
MultiTemplateParamsArg(), AddToScope, Bindings);
if (AddToScope) {
S->AddDecl(New);
CurContext->addHiddenDecl(New);
}
if (isInOpenMPDeclareTargetContext())
checkDeclIsAllowedInOpenMPTarget(nullptr, New);
return New;
}
static bool checkSimpleDecomposition(
Sema &S, ArrayRef<BindingDecl *> Bindings, ValueDecl *Src,
QualType DecompType, const llvm::APSInt &NumElems, QualType ElemType,
llvm::function_ref<ExprResult(SourceLocation, Expr *, unsigned)> GetInit) {
if ((int64_t)Bindings.size() != NumElems) {
S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
<< DecompType << (unsigned)Bindings.size()
<< (unsigned)NumElems.getLimitedValue(UINT_MAX)
<< toString(NumElems, 10) << (NumElems < Bindings.size());
return true;
}
unsigned I = 0;
for (auto *B : Bindings) {
SourceLocation Loc = B->getLocation();
ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
if (E.isInvalid())
return true;
E = GetInit(Loc, E.get(), I++);
if (E.isInvalid())
return true;
B->setBinding(ElemType, E.get());
}
return false;
}
static bool checkArrayLikeDecomposition(Sema &S,
ArrayRef<BindingDecl *> Bindings,
ValueDecl *Src, QualType DecompType,
const llvm::APSInt &NumElems,
QualType ElemType) {
return checkSimpleDecomposition(
S, Bindings, Src, DecompType, NumElems, ElemType,
[&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
ExprResult E = S.ActOnIntegerConstant(Loc, I);
if (E.isInvalid())
return ExprError();
return S.CreateBuiltinArraySubscriptExpr(Base, Loc, E.get(), Loc);
});
}
static bool checkArrayDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
ValueDecl *Src, QualType DecompType,
const ConstantArrayType *CAT) {
return checkArrayLikeDecomposition(S, Bindings, Src, DecompType,
llvm::APSInt(CAT->getSize()),
CAT->getElementType());
}
static bool checkVectorDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
ValueDecl *Src, QualType DecompType,
const VectorType *VT) {
return checkArrayLikeDecomposition(
S, Bindings, Src, DecompType, llvm::APSInt::get(VT->getNumElements()),
S.Context.getQualifiedType(VT->getElementType(),
DecompType.getQualifiers()));
}
static bool checkComplexDecomposition(Sema &S,
ArrayRef<BindingDecl *> Bindings,
ValueDecl *Src, QualType DecompType,
const ComplexType *CT) {
return checkSimpleDecomposition(
S, Bindings, Src, DecompType, llvm::APSInt::get(2),
S.Context.getQualifiedType(CT->getElementType(),
DecompType.getQualifiers()),
[&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
return S.CreateBuiltinUnaryOp(Loc, I ? UO_Imag : UO_Real, Base);
});
}
static std::string printTemplateArgs(const PrintingPolicy &PrintingPolicy,
TemplateArgumentListInfo &Args,
const TemplateParameterList *Params) {
SmallString<128> SS;
llvm::raw_svector_ostream OS(SS);
bool First = true;
unsigned I = 0;
for (auto &Arg : Args.arguments()) {
if (!First)
OS << ", ";
Arg.getArgument().print(PrintingPolicy, OS,
TemplateParameterList::shouldIncludeTypeForArgument(
PrintingPolicy, Params, I));
First = false;
I++;
}
return std::string(OS.str());
}
static bool lookupStdTypeTraitMember(Sema &S, LookupResult &TraitMemberLookup,
SourceLocation Loc, StringRef Trait,
TemplateArgumentListInfo &Args,
unsigned DiagID) {
auto DiagnoseMissing = [&] {
if (DiagID)
S.Diag(Loc, DiagID) << printTemplateArgs(S.Context.getPrintingPolicy(),
Args, /*Params*/ nullptr);
return true;
};
// FIXME: Factor out duplication with lookupPromiseType in SemaCoroutine.
NamespaceDecl *Std = S.getStdNamespace();
if (!Std)
return DiagnoseMissing();
// Look up the trait itself, within namespace std. We can diagnose various
// problems with this lookup even if we've been asked to not diagnose a
// missing specialization, because this can only fail if the user has been
// declaring their own names in namespace std or we don't support the
// standard library implementation in use.
LookupResult Result(S, &S.PP.getIdentifierTable().get(Trait),
Loc, Sema::LookupOrdinaryName);
if (!S.LookupQualifiedName(Result, Std))
return DiagnoseMissing();
if (Result.isAmbiguous())
return true;
ClassTemplateDecl *TraitTD = Result.getAsSingle<ClassTemplateDecl>();
if (!TraitTD) {
Result.suppressDiagnostics();
NamedDecl *Found = *Result.begin();
S.Diag(Loc, diag::err_std_type_trait_not_class_template) << Trait;
S.Diag(Found->getLocation(), diag::note_declared_at);
return true;
}
// Build the template-id.
QualType TraitTy = S.CheckTemplateIdType(TemplateName(TraitTD), Loc, Args);
if (TraitTy.isNull())
return true;
if (!S.isCompleteType(Loc, TraitTy)) {
if (DiagID)
S.RequireCompleteType(
Loc, TraitTy, DiagID,
printTemplateArgs(S.Context.getPrintingPolicy(), Args,
TraitTD->getTemplateParameters()));
return true;
}
CXXRecordDecl *RD = TraitTy->getAsCXXRecordDecl();
assert(RD && "specialization of class template is not a class?");
// Look up the member of the trait type.
S.LookupQualifiedName(TraitMemberLookup, RD);
return TraitMemberLookup.isAmbiguous();
}
static TemplateArgumentLoc
getTrivialIntegralTemplateArgument(Sema &S, SourceLocation Loc, QualType T,
uint64_t I) {
TemplateArgument Arg(S.Context, S.Context.MakeIntValue(I, T), T);
return S.getTrivialTemplateArgumentLoc(Arg, T, Loc);
}
static TemplateArgumentLoc
getTrivialTypeTemplateArgument(Sema &S, SourceLocation Loc, QualType T) {
return S.getTrivialTemplateArgumentLoc(TemplateArgument(T), QualType(), Loc);
}
namespace { enum class IsTupleLike { TupleLike, NotTupleLike, Error }; }
static IsTupleLike isTupleLike(Sema &S, SourceLocation Loc, QualType T,
llvm::APSInt &Size) {
EnterExpressionEvaluationContext ContextRAII(
S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
DeclarationName Value = S.PP.getIdentifierInfo("value");
LookupResult R(S, Value, Loc, Sema::LookupOrdinaryName);
// Form template argument list for tuple_size<T>.
TemplateArgumentListInfo Args(Loc, Loc);
Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));
// If there's no tuple_size specialization or the lookup of 'value' is empty,
// it's not tuple-like.
if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/ 0) ||
R.empty())
return IsTupleLike::NotTupleLike;
// If we get this far, we've committed to the tuple interpretation, but
// we can still fail if there actually isn't a usable ::value.
struct ICEDiagnoser : Sema::VerifyICEDiagnoser {
LookupResult &R;
TemplateArgumentListInfo &Args;
ICEDiagnoser(LookupResult &R, TemplateArgumentListInfo &Args)
: R(R), Args(Args) {}
Sema::SemaDiagnosticBuilder diagnoseNotICE(Sema &S,
SourceLocation Loc) override {
return S.Diag(Loc, diag::err_decomp_decl_std_tuple_size_not_constant)
<< printTemplateArgs(S.Context.getPrintingPolicy(), Args,
/*Params*/ nullptr);
}
} Diagnoser(R, Args);
ExprResult E =
S.BuildDeclarationNameExpr(CXXScopeSpec(), R, /*NeedsADL*/false);
if (E.isInvalid())
return IsTupleLike::Error;
E = S.VerifyIntegerConstantExpression(E.get(), &Size, Diagnoser);
if (E.isInvalid())
return IsTupleLike::Error;
return IsTupleLike::TupleLike;
}
/// \return std::tuple_element<I, T>::type.
static QualType getTupleLikeElementType(Sema &S, SourceLocation Loc,
unsigned I, QualType T) {
// Form template argument list for tuple_element<I, T>.
TemplateArgumentListInfo Args(Loc, Loc);
Args.addArgument(
getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));
DeclarationName TypeDN = S.PP.getIdentifierInfo("type");
LookupResult R(S, TypeDN, Loc, Sema::LookupOrdinaryName);
if (lookupStdTypeTraitMember(
S, R, Loc, "tuple_element", Args,
diag::err_decomp_decl_std_tuple_element_not_specialized))
return QualType();
auto *TD = R.getAsSingle<TypeDecl>();
if (!TD) {
R.suppressDiagnostics();
S.Diag(Loc, diag::err_decomp_decl_std_tuple_element_not_specialized)
<< printTemplateArgs(S.Context.getPrintingPolicy(), Args,
/*Params*/ nullptr);
if (!R.empty())
S.Diag(R.getRepresentativeDecl()->getLocation(), diag::note_declared_at);
return QualType();
}
return S.Context.getTypeDeclType(TD);
}
namespace {
struct InitializingBinding {
Sema &S;
InitializingBinding(Sema &S, BindingDecl *BD) : S(S) {
Sema::CodeSynthesisContext Ctx;
Ctx.Kind = Sema::CodeSynthesisContext::InitializingStructuredBinding;
Ctx.PointOfInstantiation = BD->getLocation();
Ctx.Entity = BD;
S.pushCodeSynthesisContext(Ctx);
}
~InitializingBinding() {
S.popCodeSynthesisContext();
}
};
}
static bool checkTupleLikeDecomposition(Sema &S,
ArrayRef<BindingDecl *> Bindings,
VarDecl *Src, QualType DecompType,
const llvm::APSInt &TupleSize) {
if ((int64_t)Bindings.size() != TupleSize) {
S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
<< DecompType << (unsigned)Bindings.size()
<< (unsigned)TupleSize.getLimitedValue(UINT_MAX)
<< toString(TupleSize, 10) << (TupleSize < Bindings.size());
return true;
}
if (Bindings.empty())
return false;
DeclarationName GetDN = S.PP.getIdentifierInfo("get");
// [dcl.decomp]p3:
// The unqualified-id get is looked up in the scope of E by class member
// access lookup ...
LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName);
bool UseMemberGet = false;
if (S.isCompleteType(Src->getLocation(), DecompType)) {
if (auto *RD = DecompType->getAsCXXRecordDecl())
S.LookupQualifiedName(MemberGet, RD);
if (MemberGet.isAmbiguous())
return true;
// ... and if that finds at least one declaration that is a function
// template whose first template parameter is a non-type parameter ...
for (NamedDecl *D : MemberGet) {
if (FunctionTemplateDecl *FTD =
dyn_cast<FunctionTemplateDecl>(D->getUnderlyingDecl())) {
TemplateParameterList *TPL = FTD->getTemplateParameters();
if (TPL->size() != 0 &&
isa<NonTypeTemplateParmDecl>(TPL->getParam(0))) {
// ... the initializer is e.get<i>().
UseMemberGet = true;
break;
}
}
}
}
unsigned I = 0;
for (auto *B : Bindings) {
InitializingBinding InitContext(S, B);
SourceLocation Loc = B->getLocation();
ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
if (E.isInvalid())
return true;
// e is an lvalue if the type of the entity is an lvalue reference and
// an xvalue otherwise
if (!Src->getType()->isLValueReferenceType())
E = ImplicitCastExpr::Create(S.Context, E.get()->getType(), CK_NoOp,
E.get(), nullptr, VK_XValue,
FPOptionsOverride());
TemplateArgumentListInfo Args(Loc, Loc);
Args.addArgument(
getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
if (UseMemberGet) {
// if [lookup of member get] finds at least one declaration, the
// initializer is e.get<i-1>().
E = S.BuildMemberReferenceExpr(E.get(), DecompType, Loc, false,
CXXScopeSpec(), SourceLocation(), nullptr,
MemberGet, &Args, nullptr);
if (E.isInvalid())
return true;
E = S.BuildCallExpr(nullptr, E.get(), Loc, None, Loc);
} else {
// Otherwise, the initializer is get<i-1>(e), where get is looked up
// in the associated namespaces.
Expr *Get = UnresolvedLookupExpr::Create(
S.Context, nullptr, NestedNameSpecifierLoc(), SourceLocation(),
DeclarationNameInfo(GetDN, Loc), /*RequiresADL*/true, &Args,
UnresolvedSetIterator(), UnresolvedSetIterator());
Expr *Arg = E.get();
E = S.BuildCallExpr(nullptr, Get, Loc, Arg, Loc);
}
if (E.isInvalid())
return true;
Expr *Init = E.get();
// Given the type T designated by std::tuple_element<i - 1, E>::type,
QualType T = getTupleLikeElementType(S, Loc, I, DecompType);
if (T.isNull())
return true;
// each vi is a variable of type "reference to T" initialized with the
// initializer, where the reference is an lvalue reference if the
// initializer is an lvalue and an rvalue reference otherwise
QualType RefType =
S.BuildReferenceType(T, E.get()->isLValue(), Loc, B->getDeclName());
if (RefType.isNull())
return true;
auto *RefVD = VarDecl::Create(
S.Context, Src->getDeclContext(), Loc, Loc,
B->getDeclName().getAsIdentifierInfo(), RefType,
S.Context.getTrivialTypeSourceInfo(T, Loc), Src->getStorageClass());
RefVD->setLexicalDeclContext(Src->getLexicalDeclContext());
RefVD->setTSCSpec(Src->getTSCSpec());
RefVD->setImplicit();
if (Src->isInlineSpecified())
RefVD->setInlineSpecified();
RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);
InitializedEntity Entity = InitializedEntity::InitializeBinding(RefVD);
InitializationKind Kind = InitializationKind::CreateCopy(Loc, Loc);
InitializationSequence Seq(S, Entity, Kind, Init);
E = Seq.Perform(S, Entity, Kind, Init);
if (E.isInvalid())
return true;
E = S.ActOnFinishFullExpr(E.get(), Loc, /*DiscardedValue*/ false);
if (E.isInvalid())
return true;
RefVD->setInit(E.get());
S.CheckCompleteVariableDeclaration(RefVD);
E = S.BuildDeclarationNameExpr(CXXScopeSpec(),
DeclarationNameInfo(B->getDeclName(), Loc),
RefVD);
if (E.isInvalid())
return true;
B->setBinding(T, E.get());
I++;
}
return false;
}
/// Find the base class to decompose in a built-in decomposition of a class type.
/// This base class search is, unfortunately, not quite like any other that we
/// perform anywhere else in C++.
static DeclAccessPair findDecomposableBaseClass(Sema &S, SourceLocation Loc,
const CXXRecordDecl *RD,
CXXCastPath &BasePath) {
auto BaseHasFields = [](const CXXBaseSpecifier *Specifier,
CXXBasePath &Path) {
return Specifier->getType()->getAsCXXRecordDecl()->hasDirectFields();
};
const CXXRecordDecl *ClassWithFields = nullptr;
AccessSpecifier AS = AS_public;
if (RD->hasDirectFields())
// [dcl.decomp]p4:
// Otherwise, all of E's non-static data members shall be public direct
// members of E ...
ClassWithFields = RD;
else {
// ... or of ...
CXXBasePaths Paths;
Paths.setOrigin(const_cast<CXXRecordDecl*>(RD));
if (!RD->lookupInBases(BaseHasFields, Paths)) {
// If no classes have fields, just decompose RD itself. (This will work
// if and only if zero bindings were provided.)
return DeclAccessPair::make(const_cast<CXXRecordDecl*>(RD), AS_public);
}
CXXBasePath *BestPath = nullptr;
for (auto &P : Paths) {
if (!BestPath)
BestPath = &P;
else if (!S.Context.hasSameType(P.back().Base->getType(),
BestPath->back().Base->getType())) {
// ... the same ...
S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
<< false << RD << BestPath->back().Base->getType()
<< P.back().Base->getType();
return DeclAccessPair();
} else if (P.Access < BestPath->Access) {
BestPath = &P;
}
}
// ... unambiguous ...
QualType BaseType = BestPath->back().Base->getType();
if (Paths.isAmbiguous(S.Context.getCanonicalType(BaseType))) {
S.Diag(Loc, diag::err_decomp_decl_ambiguous_base)
<< RD << BaseType << S.getAmbiguousPathsDisplayString(Paths);
return DeclAccessPair();
}
// ... [accessible, implied by other rules] base class of E.
S.CheckBaseClassAccess(Loc, BaseType, S.Context.getRecordType(RD),
*BestPath, diag::err_decomp_decl_inaccessible_base);
AS = BestPath->Access;
ClassWithFields = BaseType->getAsCXXRecordDecl();
S.BuildBasePathArray(Paths, BasePath);
}
// The above search did not check whether the selected class itself has base
// classes with fields, so check that now.
CXXBasePaths Paths;
if (ClassWithFields->lookupInBases(BaseHasFields, Paths)) {
S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
<< (ClassWithFields == RD) << RD << ClassWithFields
<< Paths.front().back().Base->getType();
return DeclAccessPair();
}
return DeclAccessPair::make(const_cast<CXXRecordDecl*>(ClassWithFields), AS);
}
static bool checkMemberDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
ValueDecl *Src, QualType DecompType,
const CXXRecordDecl *OrigRD) {
if (S.RequireCompleteType(Src->getLocation(), DecompType,
diag::err_incomplete_type))
return true;
CXXCastPath BasePath;
DeclAccessPair BasePair =
findDecomposableBaseClass(S, Src->getLocation(), OrigRD, BasePath);
const CXXRecordDecl *RD = cast_or_null<CXXRecordDecl>(BasePair.getDecl());
if (!RD)
return true;
QualType BaseType = S.Context.getQualifiedType(S.Context.getRecordType(RD),
DecompType.getQualifiers());
auto DiagnoseBadNumberOfBindings = [&]() -> bool {
unsigned NumFields = llvm::count_if(
RD->fields(), [](FieldDecl *FD) { return !FD->isUnnamedBitfield(); });
assert(Bindings.size() != NumFields);
S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
<< DecompType << (unsigned)Bindings.size() << NumFields << NumFields
<< (NumFields < Bindings.size());
return true;
};
// all of E's non-static data members shall be [...] well-formed
// when named as e.name in the context of the structured binding,
// E shall not have an anonymous union member, ...
unsigned I = 0;
for (auto *FD : RD->fields()) {
if (FD->isUnnamedBitfield())
continue;
// All the non-static data members are required to be nameable, so they
// must all have names.
if (!FD->getDeclName()) {
if (RD->isLambda()) {
S.Diag(Src->getLocation(), diag::err_decomp_decl_lambda);
S.Diag(RD->getLocation(), diag::note_lambda_decl);
return true;
}
if (FD->isAnonymousStructOrUnion()) {
S.Diag(Src->getLocation(), diag::err_decomp_decl_anon_union_member)
<< DecompType << FD->getType()->isUnionType();
S.Diag(FD->getLocation(), diag::note_declared_at);
return true;
}
// FIXME: Are there any other ways we could have an anonymous member?
}
// We have a real field to bind.
if (I >= Bindings.size())
return DiagnoseBadNumberOfBindings();
auto *B = Bindings[I++];
SourceLocation Loc = B->getLocation();
// The field must be accessible in the context of the structured binding.
// We already checked that the base class is accessible.
// FIXME: Add 'const' to AccessedEntity's classes so we can remove the
// const_cast here.
S.CheckStructuredBindingMemberAccess(
Loc, const_cast<CXXRecordDecl *>(OrigRD),
DeclAccessPair::make(FD, CXXRecordDecl::MergeAccess(
BasePair.getAccess(), FD->getAccess())));
// Initialize the binding to Src.FD.
ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
if (E.isInvalid())
return true;
E = S.ImpCastExprToType(E.get(), BaseType, CK_UncheckedDerivedToBase,
VK_LValue, &BasePath);
if (E.isInvalid())
return true;
E = S.BuildFieldReferenceExpr(E.get(), /*IsArrow*/ false, Loc,
CXXScopeSpec(), FD,
DeclAccessPair::make(FD, FD->getAccess()),
DeclarationNameInfo(FD->getDeclName(), Loc));
if (E.isInvalid())
return true;
// If the type of the member is T, the referenced type is cv T, where cv is
// the cv-qualification of the decomposition expression.
//
// FIXME: We resolve a defect here: if the field is mutable, we do not add
// 'const' to the type of the field.
Qualifiers Q = DecompType.getQualifiers();
if (FD->isMutable())
Q.removeConst();
B->setBinding(S.BuildQualifiedType(FD->getType(), Loc, Q), E.get());
}
if (I != Bindings.size())
return DiagnoseBadNumberOfBindings();
return false;
}
void Sema::CheckCompleteDecompositionDeclaration(DecompositionDecl *DD) {
QualType DecompType = DD->getType();
// If the type of the decomposition is dependent, then so is the type of
// each binding.
if (DecompType->isDependentType()) {
for (auto *B : DD->bindings())
B->setType(Context.DependentTy);
return;
}
DecompType = DecompType.getNonReferenceType();
ArrayRef<BindingDecl*> Bindings = DD->bindings();
// C++1z [dcl.decomp]/2:
// If E is an array type [...]
// As an extension, we also support decomposition of built-in complex and
// vector types.
if (auto *CAT = Context.getAsConstantArrayType(DecompType)) {
if (checkArrayDecomposition(*this, Bindings, DD, DecompType, CAT))
DD->setInvalidDecl();
return;
}
if (auto *VT = DecompType->getAs<VectorType>()) {
if (checkVectorDecomposition(*this, Bindings, DD, DecompType, VT))
DD->setInvalidDecl();
return;
}
if (auto *CT = DecompType->getAs<ComplexType>()) {
if (checkComplexDecomposition(*this, Bindings, DD, DecompType, CT))
DD->setInvalidDecl();
return;
}
// C++1z [dcl.decomp]/3:
// if the expression std::tuple_size<E>::value is a well-formed integral
// constant expression, [...]
llvm::APSInt TupleSize(32);
switch (isTupleLike(*this, DD->getLocation(), DecompType, TupleSize)) {
case IsTupleLike::Error:
DD->setInvalidDecl();
return;
case IsTupleLike::TupleLike:
if (checkTupleLikeDecomposition(*this, Bindings, DD, DecompType, TupleSize))
DD->setInvalidDecl();
return;
case IsTupleLike::NotTupleLike:
break;
}
// C++1z [dcl.dcl]/8:
// [E shall be of array or non-union class type]
CXXRecordDecl *RD = DecompType->getAsCXXRecordDecl();
if (!RD || RD->isUnion()) {
Diag(DD->getLocation(), diag::err_decomp_decl_unbindable_type)
<< DD << !RD << DecompType;
DD->setInvalidDecl();
return;
}
// C++1z [dcl.decomp]/4:
// all of E's non-static data members shall be [...] direct members of
// E or of the same unambiguous public base class of E, ...
if (checkMemberDecomposition(*this, Bindings, DD, DecompType, RD))
DD->setInvalidDecl();
}
/// Merge the exception specifications of two variable declarations.
///
/// This is called when there's a redeclaration of a VarDecl. The function
/// checks if the redeclaration might have an exception specification and
/// validates compatibility and merges the specs if necessary.
void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) {
// Shortcut if exceptions are disabled.
if (!getLangOpts().CXXExceptions)
return;
assert(Context.hasSameType(New->getType(), Old->getType()) &&
"Should only be called if types are otherwise the same.");
QualType NewType = New->getType();
QualType OldType = Old->getType();
// We're only interested in pointers and references to functions, as well
// as pointers to member functions.
if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
NewType = R->getPointeeType();
OldType = OldType->castAs<ReferenceType>()->getPointeeType();
} else if (const PointerType *P = NewType->getAs<PointerType>()) {
NewType = P->getPointeeType();
OldType = OldType->castAs<PointerType>()->getPointeeType();
} else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
NewType = M->getPointeeType();
OldType = OldType->castAs<MemberPointerType>()->getPointeeType();
}
if (!NewType->isFunctionProtoType())
return;
// There's lots of special cases for functions. For function pointers, system
// libraries are hopefully not as broken so that we don't need these
// workarounds.
if (CheckEquivalentExceptionSpec(
OldType->getAs<FunctionProtoType>(), Old->getLocation(),
NewType->getAs<FunctionProtoType>(), New->getLocation())) {
New->setInvalidDecl();
}
}
/// CheckCXXDefaultArguments - Verify that the default arguments for a
/// function declaration are well-formed according to C++
/// [dcl.fct.default].
void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
unsigned NumParams = FD->getNumParams();
unsigned ParamIdx = 0;
// This checking doesn't make sense for explicit specializations; their
// default arguments are determined by the declaration we're specializing,
// not by FD.
if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
return;
if (auto *FTD = FD->getDescribedFunctionTemplate())
if (FTD->isMemberSpecialization())
return;
// Find first parameter with a default argument
for (; ParamIdx < NumParams; ++ParamIdx) {
ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
if (Param->hasDefaultArg())
break;
}
// C++20 [dcl.fct.default]p4:
// In a given function declaration, each parameter subsequent to a parameter
// with a default argument shall have a default argument supplied in this or
// a previous declaration, unless the parameter was expanded from a
// parameter pack, or shall be a function parameter pack.
for (; ParamIdx < NumParams; ++ParamIdx) {
ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
if (!Param->hasDefaultArg() && !Param->isParameterPack() &&
!(CurrentInstantiationScope &&
CurrentInstantiationScope->isLocalPackExpansion(Param))) {
if (Param->isInvalidDecl())
/* We already complained about this parameter. */;
else if (Param->getIdentifier())
Diag(Param->getLocation(),
diag::err_param_default_argument_missing_name)
<< Param->getIdentifier();
else
Diag(Param->getLocation(),
diag::err_param_default_argument_missing);
}
}
}
/// Check that the given type is a literal type. Issue a diagnostic if not,
/// if Kind is Diagnose.
/// \return \c true if a problem has been found (and optionally diagnosed).
template <typename... Ts>
static bool CheckLiteralType(Sema &SemaRef, Sema::CheckConstexprKind Kind,
SourceLocation Loc, QualType T, unsigned DiagID,
Ts &&...DiagArgs) {
if (T->isDependentType())
return false;
switch (Kind) {
case Sema::CheckConstexprKind::Diagnose:
return SemaRef.RequireLiteralType(Loc, T, DiagID,
std::forward<Ts>(DiagArgs)...);
case Sema::CheckConstexprKind::CheckValid:
return !T->isLiteralType(SemaRef.Context);
}
llvm_unreachable("unknown CheckConstexprKind");
}
/// Determine whether a destructor cannot be constexpr due to
static bool CheckConstexprDestructorSubobjects(Sema &SemaRef,
const CXXDestructorDecl *DD,
Sema::CheckConstexprKind Kind) {
auto Check = [&](SourceLocation Loc, QualType T, const FieldDecl *FD) {
const CXXRecordDecl *RD =
T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
if (!RD || RD->hasConstexprDestructor())
return true;
if (Kind == Sema::CheckConstexprKind::Diagnose) {
SemaRef.Diag(DD->getLocation(), diag::err_constexpr_dtor_subobject)
<< static_cast<int>(DD->getConstexprKind()) << !FD
<< (FD ? FD->getDeclName() : DeclarationName()) << T;
SemaRef.Diag(Loc, diag::note_constexpr_dtor_subobject)
<< !FD << (FD ? FD->getDeclName() : DeclarationName()) << T;
}
return false;
};
const CXXRecordDecl *RD = DD->getParent();
for (const CXXBaseSpecifier &B : RD->bases())
if (!Check(B.getBaseTypeLoc(), B.getType(), nullptr))
return false;
for (const FieldDecl *FD : RD->fields())
if (!Check(FD->getLocation(), FD->getType(), FD))
return false;
return true;
}
/// Check whether a function's parameter types are all literal types. If so,
/// return true. If not, produce a suitable diagnostic and return false.
static bool CheckConstexprParameterTypes(Sema &SemaRef,
const FunctionDecl *FD,
Sema::CheckConstexprKind Kind) {
unsigned ArgIndex = 0;
const auto *FT = FD->getType()->castAs<FunctionProtoType>();
for (FunctionProtoType::param_type_iterator i = FT->param_type_begin(),
e = FT->param_type_end();
i != e; ++i, ++ArgIndex) {
const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
SourceLocation ParamLoc = PD->getLocation();
if (CheckLiteralType(SemaRef, Kind, ParamLoc, *i,
diag::err_constexpr_non_literal_param, ArgIndex + 1,
PD->getSourceRange(), isa<CXXConstructorDecl>(FD),
FD->isConsteval()))
return false;
}
return true;
}
/// Check whether a function's return type is a literal type. If so, return
/// true. If not, produce a suitable diagnostic and return false.
static bool CheckConstexprReturnType(Sema &SemaRef, const FunctionDecl *FD,
Sema::CheckConstexprKind Kind) {
if (CheckLiteralType(SemaRef, Kind, FD->getLocation(), FD->getReturnType(),
diag::err_constexpr_non_literal_return,
FD->isConsteval()))
return false;
return true;
}
/// Get diagnostic %select index for tag kind for
/// record diagnostic message.
/// WARNING: Indexes apply to particular diagnostics only!
///
/// \returns diagnostic %select index.
static unsigned getRecordDiagFromTagKind(TagTypeKind Tag) {
switch (Tag) {
case TTK_Struct: return 0;
case TTK_Interface: return 1;
case TTK_Class: return 2;
default: llvm_unreachable("Invalid tag kind for record diagnostic!");
}
}
static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
Stmt *Body,
Sema::CheckConstexprKind Kind);
// Check whether a function declaration satisfies the requirements of a
// constexpr function definition or a constexpr constructor definition. If so,
// return true. If not, produce appropriate diagnostics (unless asked not to by
// Kind) and return false.
//
// This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
bool Sema::CheckConstexprFunctionDefinition(const FunctionDecl *NewFD,
CheckConstexprKind Kind) {
const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
if (MD && MD->isInstance()) {
// C++11 [dcl.constexpr]p4:
// The definition of a constexpr constructor shall satisfy the following
// constraints:
// - the class shall not have any virtual base classes;
//
// FIXME: This only applies to constructors and destructors, not arbitrary
// member functions.
const CXXRecordDecl *RD = MD->getParent();
if (RD->getNumVBases()) {
if (Kind == CheckConstexprKind::CheckValid)
return false;
Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
<< isa<CXXConstructorDecl>(NewFD)
<< getRecordDiagFromTagKind(RD->getTagKind()) << RD->getNumVBases();
for (const auto &I : RD->vbases())
Diag(I.getBeginLoc(), diag::note_constexpr_virtual_base_here)
<< I.getSourceRange();
return false;
}
}
if (!isa<CXXConstructorDecl>(NewFD)) {
// C++11 [dcl.constexpr]p3:
// The definition of a constexpr function shall satisfy the following
// constraints:
// - it shall not be virtual; (removed in C++20)
const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
if (Method && Method->isVirtual()) {
if (getLangOpts().CPlusPlus20) {
if (Kind == CheckConstexprKind::Diagnose)
Diag(Method->getLocation(), diag::warn_cxx17_compat_constexpr_virtual);
} else {
if (Kind == CheckConstexprKind::CheckValid)
return false;
Method = Method->getCanonicalDecl();
Diag(Method->getLocation(), diag::err_constexpr_virtual);
// If it's not obvious why this function is virtual, find an overridden
// function which uses the 'virtual' keyword.
const CXXMethodDecl *WrittenVirtual = Method;
while (!WrittenVirtual->isVirtualAsWritten())
WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
if (WrittenVirtual != Method)
Diag(WrittenVirtual->getLocation(),
diag::note_overridden_virtual_function);
return false;
}
}
// - its return type shall be a literal type;
if (!CheckConstexprReturnType(*this, NewFD, Kind))
return false;
}
if (auto *Dtor = dyn_cast<CXXDestructorDecl>(NewFD)) {
// A destructor can be constexpr only if the defaulted destructor could be;
// we don't need to check the members and bases if we already know they all
// have constexpr destructors.
if (!Dtor->getParent()->defaultedDestructorIsConstexpr()) {
if (Kind == CheckConstexprKind::CheckValid)
return false;
if (!CheckConstexprDestructorSubobjects(*this, Dtor, Kind))
return false;
}
}
// - each of its parameter types shall be a literal type;
if (!CheckConstexprParameterTypes(*this, NewFD, Kind))
return false;
Stmt *Body = NewFD->getBody();
assert(Body &&
"CheckConstexprFunctionDefinition called on function with no body");
return CheckConstexprFunctionBody(*this, NewFD, Body, Kind);
}
/// Check the given declaration statement is legal within a constexpr function
/// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3.
///
/// \return true if the body is OK (maybe only as an extension), false if we
/// have diagnosed a problem.
static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
DeclStmt *DS, SourceLocation &Cxx1yLoc,
Sema::CheckConstexprKind Kind) {
// C++11 [dcl.constexpr]p3 and p4:
// The definition of a constexpr function(p3) or constructor(p4) [...] shall
// contain only
for (const auto *DclIt : DS->decls()) {
switch (DclIt->getKind()) {
case Decl::StaticAssert:
case Decl::Using:
case Decl::UsingShadow:
case Decl::UsingDirective:
case Decl::UnresolvedUsingTypename:
case Decl::UnresolvedUsingValue:
case Decl::UsingEnum:
// - static_assert-declarations
// - using-declarations,
// - using-directives,
// - using-enum-declaration
continue;
case Decl::Typedef:
case Decl::TypeAlias: {
// - typedef declarations and alias-declarations that do not define
// classes or enumerations,
const auto *TN = cast<TypedefNameDecl>(DclIt);
if (TN->getUnderlyingType()->isVariablyModifiedType()) {
// Don't allow variably-modified types in constexpr functions.
if (Kind == Sema::CheckConstexprKind::Diagnose) {
TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
<< TL.getSourceRange() << TL.getType()
<< isa<CXXConstructorDecl>(Dcl);
}
return false;
}
continue;
}
case Decl::Enum:
case Decl::CXXRecord:
// C++1y allows types to be defined, not just declared.
if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition()) {
if (Kind == Sema::CheckConstexprKind::Diagnose) {
SemaRef.Diag(DS->getBeginLoc(),
SemaRef.getLangOpts().CPlusPlus14
? diag::warn_cxx11_compat_constexpr_type_definition
: diag::ext_constexpr_type_definition)
<< isa<CXXConstructorDecl>(Dcl);
} else if (!SemaRef.getLangOpts().CPlusPlus14) {
return false;
}
}
continue;
case Decl::EnumConstant:
case Decl::IndirectField:
case Decl::ParmVar:
// These can only appear with other declarations which are banned in
// C++11 and permitted in C++1y, so ignore them.
continue;
case Decl::Var:
case Decl::Decomposition: {
// C++1y [dcl.constexpr]p3 allows anything except:
// a definition of a variable of non-literal type or of static or
// thread storage duration or [before C++2a] for which no
// initialization is performed.
const auto *VD = cast<VarDecl>(DclIt);
if (VD->isThisDeclarationADefinition()) {
if (VD->isStaticLocal()) {
if (Kind == Sema::CheckConstexprKind::Diagnose) {
SemaRef.Diag(VD->getLocation(),
diag::err_constexpr_local_var_static)
<< isa<CXXConstructorDecl>(Dcl)
<< (VD->getTLSKind() == VarDecl::TLS_Dynamic);
}
return false;
}
if (CheckLiteralType(SemaRef, Kind, VD->getLocation(), VD->getType(),
diag::err_constexpr_local_var_non_literal_type,
isa<CXXConstructorDecl>(Dcl)))
return false;
if (!VD->getType()->isDependentType() &&
!VD->hasInit() && !VD->isCXXForRangeDecl()) {
if (Kind == Sema::CheckConstexprKind::Diagnose) {
SemaRef.Diag(
VD->getLocation(),
SemaRef.getLangOpts().CPlusPlus20
? diag::warn_cxx17_compat_constexpr_local_var_no_init
: diag::ext_constexpr_local_var_no_init)
<< isa<CXXConstructorDecl>(Dcl);
} else if (!SemaRef.getLangOpts().CPlusPlus20) {
return false;
}
continue;
}
}
if (Kind == Sema::CheckConstexprKind::Diagnose) {
SemaRef.Diag(VD->getLocation(),
SemaRef.getLangOpts().CPlusPlus14
? diag::warn_cxx11_compat_constexpr_local_var
: diag::ext_constexpr_local_var)
<< isa<CXXConstructorDecl>(Dcl);
} else if (!SemaRef.getLangOpts().CPlusPlus14) {
return false;
}
continue;
}
case Decl::NamespaceAlias:
case Decl::Function:
// These are disallowed in C++11 and permitted in C++1y. Allow them
// everywhere as an extension.
if (!Cxx1yLoc.isValid())
Cxx1yLoc = DS->getBeginLoc();
continue;
default:
if (Kind == Sema::CheckConstexprKind::Diagnose) {
SemaRef.Diag(DS->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
<< isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
}
return false;
}
}
return true;
}
/// Check that the given field is initialized within a constexpr constructor.
///
/// \param Dcl The constexpr constructor being checked.
/// \param Field The field being checked. This may be a member of an anonymous
/// struct or union nested within the class being checked.
/// \param Inits All declarations, including anonymous struct/union members and
/// indirect members, for which any initialization was provided.
/// \param Diagnosed Whether we've emitted the error message yet. Used to attach
/// multiple notes for different members to the same error.
/// \param Kind Whether we're diagnosing a constructor as written or determining
/// whether the formal requirements are satisfied.
/// \return \c false if we're checking for validity and the constructor does
/// not satisfy the requirements on a constexpr constructor.
static bool CheckConstexprCtorInitializer(Sema &SemaRef,
const FunctionDecl *Dcl,
FieldDecl *Field,
llvm::SmallSet<Decl*, 16> &Inits,
bool &Diagnosed,
Sema::CheckConstexprKind Kind) {
// In C++20 onwards, there's nothing to check for validity.
if (Kind == Sema::CheckConstexprKind::CheckValid &&
SemaRef.getLangOpts().CPlusPlus20)
return true;
if (Field->isInvalidDecl())
return true;
if (Field->isUnnamedBitfield())
return true;
// Anonymous unions with no variant members and empty anonymous structs do not
// need to be explicitly initialized. FIXME: Anonymous structs that contain no
// indirect fields don't need initializing.
if (Field->isAnonymousStructOrUnion() &&
(Field->getType()->isUnionType()
? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers()
: Field->getType()->getAsCXXRecordDecl()->isEmpty()))
return true;
if (!Inits.count(Field)) {
if (Kind == Sema::CheckConstexprKind::Diagnose) {
if (!Diagnosed) {
SemaRef.Diag(Dcl->getLocation(),
SemaRef.getLangOpts().CPlusPlus20
? diag::warn_cxx17_compat_constexpr_ctor_missing_init
: diag::ext_constexpr_ctor_missing_init);
Diagnosed = true;
}
SemaRef.Diag(Field->getLocation(),
diag::note_constexpr_ctor_missing_init);
} else if (!SemaRef.getLangOpts().CPlusPlus20) {
return false;
}
} else if (Field->isAnonymousStructOrUnion()) {
const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
for (auto *I : RD->fields())
// If an anonymous union contains an anonymous struct of which any member
// is initialized, all members must be initialized.
if (!RD->isUnion() || Inits.count(I))
if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
Kind))
return false;
}
return true;
}
/// Check the provided statement is allowed in a constexpr function
/// definition.
static bool
CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S,
SmallVectorImpl<SourceLocation> &ReturnStmts,
SourceLocation &Cxx1yLoc, SourceLocation &Cxx2aLoc,
Sema::CheckConstexprKind Kind) {
// - its function-body shall be [...] a compound-statement that contains only
switch (S->getStmtClass()) {
case Stmt::NullStmtClass:
// - null statements,
return true;
case Stmt::DeclStmtClass:
// - static_assert-declarations
// - using-declarations,
// - using-directives,
// - typedef declarations and alias-declarations that do not define
// classes or enumerations,
if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc, Kind))
return false;
return true;
case Stmt::ReturnStmtClass:
// - and exactly one return statement;
if (isa<CXXConstructorDecl>(Dcl)) {
// C++1y allows return statements in constexpr constructors.
if (!Cxx1yLoc.isValid())
Cxx1yLoc = S->getBeginLoc();
return true;
}
ReturnStmts.push_back(S->getBeginLoc());
return true;
case Stmt::AttributedStmtClass:
// Attributes on a statement don't affect its formal kind and hence don't
// affect its validity in a constexpr function.
return CheckConstexprFunctionStmt(SemaRef, Dcl,
cast<AttributedStmt>(S)->getSubStmt(),
ReturnStmts, Cxx1yLoc, Cxx2aLoc, Kind);
case Stmt::CompoundStmtClass: {
// C++1y allows compound-statements.
if (!Cxx1yLoc.isValid())
Cxx1yLoc = S->getBeginLoc();
CompoundStmt *CompStmt = cast<CompoundStmt>(S);
for (auto *BodyIt : CompStmt->body()) {
if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
Cxx1yLoc, Cxx2aLoc, Kind))
return false;
}
return true;
}
case Stmt::IfStmtClass: {
// C++1y allows if-statements.
if (!Cxx1yLoc.isValid())
Cxx1yLoc = S->getBeginLoc();
IfStmt *If = cast<IfStmt>(S);
if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts,
Cxx1yLoc, Cxx2aLoc, Kind))
return false;
if (If->getElse() &&
!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts,
Cxx1yLoc, Cxx2aLoc, Kind))
return false;
return true;
}
case Stmt::WhileStmtClass:
case Stmt::DoStmtClass:
case Stmt::ForStmtClass:
case Stmt::CXXForRangeStmtClass:
case Stmt::ContinueStmtClass:
// C++1y allows all of these. We don't allow them as extensions in C++11,
// because they don't make sense without variable mutation.
if (!SemaRef.getLangOpts().CPlusPlus14)
break;
if (!Cxx1yLoc.isValid())
Cxx1yLoc = S->getBeginLoc();
for (Stmt *SubStmt : S->children())
if (SubStmt &&
!CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
Cxx1yLoc, Cxx2aLoc, Kind))
return false;
return true;
case Stmt::SwitchStmtClass:
case Stmt::CaseStmtClass:
case Stmt::DefaultStmtClass:
case Stmt::BreakStmtClass:
// C++1y allows switch-statements, and since they don't need variable
// mutation, we can reasonably allow them in C++11 as an extension.
if (!Cxx1yLoc.isValid())
Cxx1yLoc = S->getBeginLoc();
for (Stmt *SubStmt : S->children())
if (SubStmt &&
!CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
Cxx1yLoc, Cxx2aLoc, Kind))
return false;
return true;
case Stmt::GCCAsmStmtClass:
case Stmt::MSAsmStmtClass:
// C++2a allows inline assembly statements.
case Stmt::CXXTryStmtClass:
if (Cxx2aLoc.isInvalid())
Cxx2aLoc = S->getBeginLoc();
for (Stmt *SubStmt : S->children()) {
if (SubStmt &&
!CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
Cxx1yLoc, Cxx2aLoc, Kind))
return false;
}
return true;
case Stmt::CXXCatchStmtClass:
// Do not bother checking the language mode (already covered by the
// try block check).
if (!CheckConstexprFunctionStmt(SemaRef, Dcl,
cast<CXXCatchStmt>(S)->getHandlerBlock(),
ReturnStmts, Cxx1yLoc, Cxx2aLoc, Kind))
return false;
return true;
default:
if (!isa<Expr>(S))
break;
// C++1y allows expression-statements.
if (!Cxx1yLoc.isValid())
Cxx1yLoc = S->getBeginLoc();
return true;
}
if (Kind == Sema::CheckConstexprKind::Diagnose) {
SemaRef.Diag(S->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
<< isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
}
return false;
}
/// Check the body for the given constexpr function declaration only contains
/// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
///
/// \return true if the body is OK, false if we have found or diagnosed a
/// problem.
static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
Stmt *Body,
Sema::CheckConstexprKind Kind) {
SmallVector<SourceLocation, 4> ReturnStmts;
if (isa<CXXTryStmt>(Body)) {
// C++11 [dcl.constexpr]p3:
// The definition of a constexpr function shall satisfy the following
// constraints: [...]
// - its function-body shall be = delete, = default, or a
// compound-statement
//
// C++11 [dcl.constexpr]p4:
// In the definition of a constexpr constructor, [...]
// - its function-body shall not be a function-try-block;
//
// This restriction is lifted in C++2a, as long as inner statements also
// apply the general constexpr rules.
switch (Kind) {
case Sema::CheckConstexprKind::CheckValid:
if (!SemaRef.getLangOpts().CPlusPlus20)
return false;
break;
case Sema::CheckConstexprKind::Diagnose:
SemaRef.Diag(Body->getBeginLoc(),
!SemaRef.getLangOpts().CPlusPlus20
? diag::ext_constexpr_function_try_block_cxx20
: diag::warn_cxx17_compat_constexpr_function_try_block)
<< isa<CXXConstructorDecl>(Dcl);
break;
}
}
// - its function-body shall be [...] a compound-statement that contains only
// [... list of cases ...]
//
// Note that walking the children here is enough to properly check for
// CompoundStmt and CXXTryStmt body.
SourceLocation Cxx1yLoc, Cxx2aLoc;
for (Stmt *SubStmt : Body->children()) {
if (SubStmt &&
!CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
Cxx1yLoc, Cxx2aLoc, Kind))
return false;
}
if (Kind == Sema::CheckConstexprKind::CheckValid) {
// If this is only valid as an extension, report that we don't satisfy the
// constraints of the current language.
if ((Cxx2aLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus20) ||
(Cxx1yLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus17))
return false;
} else if (Cxx2aLoc.isValid()) {
SemaRef.Diag(Cxx2aLoc,
SemaRef.getLangOpts().CPlusPlus20
? diag::warn_cxx17_compat_constexpr_body_invalid_stmt
: diag::ext_constexpr_body_invalid_stmt_cxx20)
<< isa<CXXConstructorDecl>(Dcl);
} else if (Cxx1yLoc.isValid()) {
SemaRef.Diag(Cxx1yLoc,
SemaRef.getLangOpts().CPlusPlus14
? diag::warn_cxx11_compat_constexpr_body_invalid_stmt
: diag::ext_constexpr_body_invalid_stmt)
<< isa<CXXConstructorDecl>(Dcl);
}
if (const CXXConstructorDecl *Constructor
= dyn_cast<CXXConstructorDecl>(Dcl)) {
const CXXRecordDecl *RD = Constructor->getParent();
// DR1359:
// - every non-variant non-static data member and base class sub-object
// shall be initialized;
// DR1460:
// - if the class is a union having variant members, exactly one of them
// shall be initialized;
if (RD->isUnion()) {
if (Constructor->getNumCtorInitializers() == 0 &&
RD->hasVariantMembers()) {
if (Kind == Sema::CheckConstexprKind::Diagnose) {
SemaRef.Diag(
Dcl->getLocation(),
SemaRef.getLangOpts().CPlusPlus20
? diag::warn_cxx17_compat_constexpr_union_ctor_no_init
: diag::ext_constexpr_union_ctor_no_init);
} else if (!SemaRef.getLangOpts().CPlusPlus20) {
return false;
}
}
} else if (!Constructor->isDependentContext() &&
!Constructor->isDelegatingConstructor()) {
assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases");
// Skip detailed checking if we have enough initializers, and we would
// allow at most one initializer per member.
bool AnyAnonStructUnionMembers = false;
unsigned Fields = 0;
for (CXXRecordDecl::field_iterator I = RD->field_begin(),
E = RD->field_end(); I != E; ++I, ++Fields) {
if (I->isAnonymousStructOrUnion()) {
AnyAnonStructUnionMembers = true;
break;
}
}
// DR1460:
// - if the class is a union-like class, but is not a union, for each of
// its anonymous union members having variant members, exactly one of
// them shall be initialized;
if (AnyAnonStructUnionMembers ||
Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
// Check initialization of non-static data members. Base classes are
// always initialized so do not need to be checked. Dependent bases
// might not have initializers in the member initializer list.
llvm::SmallSet<Decl*, 16> Inits;
for (const auto *I: Constructor->inits()) {
if (FieldDecl *FD = I->getMember())
Inits.insert(FD);
else if (IndirectFieldDecl *ID = I->getIndirectMember())
Inits.insert(ID->chain_begin(), ID->chain_end());
}
bool Diagnosed = false;
for (auto *I : RD->fields())
if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
Kind))
return false;
}
}
} else {
if (ReturnStmts.empty()) {
// C++1y doesn't require constexpr functions to contain a 'return'
// statement. We still do, unless the return type might be void, because
// otherwise if there's no return statement, the function cannot
// be used in a core constant expression.
bool OK = SemaRef.getLangOpts().CPlusPlus14 &&
(Dcl->getReturnType()->isVoidType() ||
Dcl->getReturnType()->isDependentType());
switch (Kind) {
case Sema::CheckConstexprKind::Diagnose:
SemaRef.Diag(Dcl->getLocation(),
OK ? diag::warn_cxx11_compat_constexpr_body_no_return
: diag::err_constexpr_body_no_return)
<< Dcl->isConsteval();
if (!OK)
return false;
break;
case Sema::CheckConstexprKind::CheckValid:
// The formal requirements don't include this rule in C++14, even
// though the "must be able to produce a constant expression" rules
// still imply it in some cases.
if (!SemaRef.getLangOpts().CPlusPlus14)
return false;
break;
}
} else if (ReturnStmts.size() > 1) {
switch (Kind) {
case Sema::CheckConstexprKind::Diagnose:
SemaRef.Diag(
ReturnStmts.back(),
SemaRef.getLangOpts().CPlusPlus14
? diag::warn_cxx11_compat_constexpr_body_multiple_return
: diag::ext_constexpr_body_multiple_return);
for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
SemaRef.Diag(ReturnStmts[I],
diag::note_constexpr_body_previous_return);
break;
case Sema::CheckConstexprKind::CheckValid:
if (!SemaRef.getLangOpts().CPlusPlus14)
return false;
break;
}
}
}
// C++11 [dcl.constexpr]p5:
// if no function argument values exist such that the function invocation
// substitution would produce a constant expression, the program is
// ill-formed; no diagnostic required.
// C++11 [dcl.constexpr]p3:
// - every constructor call and implicit conversion used in initializing the
// return value shall be one of those allowed in a constant expression.
// C++11 [dcl.constexpr]p4:
// - every constructor involved in initializing non-static data members and
// base class sub-objects shall be a constexpr constructor.
//
// Note that this rule is distinct from the "requirements for a constexpr
// function", so is not checked in CheckValid mode.
SmallVector<PartialDiagnosticAt, 8> Diags;
if (Kind == Sema::CheckConstexprKind::Diagnose &&
!Expr::isPotentialConstantExpr(Dcl, Diags)) {
SemaRef.Diag(Dcl->getLocation(),
diag::ext_constexpr_function_never_constant_expr)
<< isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
for (size_t I = 0, N = Diags.size(); I != N; ++I)
SemaRef.Diag(Diags[I].first, Diags[I].second);
// Don't return false here: we allow this for compatibility in
// system headers.
}
return true;
}
/// Get the class that is directly named by the current context. This is the
/// class for which an unqualified-id in this scope could name a constructor
/// or destructor.
///
/// If the scope specifier denotes a class, this will be that class.
/// If the scope specifier is empty, this will be the class whose
/// member-specification we are currently within. Otherwise, there
/// is no such class.
CXXRecordDecl *Sema::getCurrentClass(Scope *, const CXXScopeSpec *SS) {
assert(getLangOpts().CPlusPlus && "No class names in C!");
if (SS && SS->isInvalid())
return nullptr;
if (SS && SS->isNotEmpty()) {
DeclContext *DC = computeDeclContext(*SS, true);
return dyn_cast_or_null<CXXRecordDecl>(DC);
}
return dyn_cast_or_null<CXXRecordDecl>(CurContext);
}
/// isCurrentClassName - Determine whether the identifier II is the
/// name of the class type currently being defined. In the case of
/// nested classes, this will only return true if II is the name of
/// the innermost class.
bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *S,
const CXXScopeSpec *SS) {
CXXRecordDecl *CurDecl = getCurrentClass(S, SS);
return CurDecl && &II == CurDecl->getIdentifier();
}
/// Determine whether the identifier II is a typo for the name of
/// the class type currently being defined. If so, update it to the identifier
/// that should have been used.
bool Sema::isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS) {
assert(getLangOpts().CPlusPlus && "No class names in C!");
if (!getLangOpts().SpellChecking)
return false;
CXXRecordDecl *CurDecl;
if (SS && SS->isSet() && !SS->isInvalid()) {
DeclContext *DC = computeDeclContext(*SS, true);
CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
} else
CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() &&
3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName())
< II->getLength()) {
II = CurDecl->getIdentifier();
return true;
}
return false;
}
/// Determine whether the given class is a base class of the given
/// class, including looking at dependent bases.
static bool findCircularInheritance(const CXXRecordDecl *Class,
const CXXRecordDecl *Current) {
SmallVector<const CXXRecordDecl*, 8> Queue;
Class = Class->getCanonicalDecl();
while (true) {
for (const auto &I : Current->bases()) {
CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl();
if (!Base)
continue;
Base = Base->getDefinition();
if (!Base)
continue;
if (Base->getCanonicalDecl() == Class)
return true;
Queue.push_back(Base);
}
if (Queue.empty())
return false;
Current = Queue.pop_back_val();
}
return false;
}
/// Check the validity of a C++ base class specifier.
///
/// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
/// and returns NULL otherwise.
CXXBaseSpecifier *
Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
SourceRange SpecifierRange,
bool Virtual, AccessSpecifier Access,
TypeSourceInfo *TInfo,
SourceLocation EllipsisLoc) {
QualType BaseType = TInfo->getType();
if (BaseType->containsErrors()) {
// Already emitted a diagnostic when parsing the error type.
return nullptr;
}
// C++ [class.union]p1:
// A union shall not have base classes.
if (Class->isUnion()) {
Diag(Class->getLocation(), diag::err_base_clause_on_union)
<< SpecifierRange;
return nullptr;
}
if (EllipsisLoc.isValid() &&
!TInfo->getType()->containsUnexpandedParameterPack()) {
Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
<< TInfo->getTypeLoc().getSourceRange();
EllipsisLoc = SourceLocation();
}
SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
if (BaseType->isDependentType()) {
// Make sure that we don't have circular inheritance among our dependent
// bases. For non-dependent bases, the check for completeness below handles
// this.
if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) {
if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() ||
((BaseDecl = BaseDecl->getDefinition()) &&
findCircularInheritance(Class, BaseDecl))) {
Diag(BaseLoc, diag::err_circular_inheritance)
<< BaseType << Context.getTypeDeclType(Class);
if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl())
Diag(BaseDecl->getLocation(), diag::note_previous_decl)
<< BaseType;
return nullptr;
}
}
// Make sure that we don't make an ill-formed AST where the type of the
// Class is non-dependent and its attached base class specifier is an
// dependent type, which violates invariants in many clang code paths (e.g.
// constexpr evaluator). If this case happens (in errory-recovery mode), we
// explicitly mark the Class decl invalid. The diagnostic was already
// emitted.
if (!Class->getTypeForDecl()->isDependentType())
Class->setInvalidDecl();
return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
Class->getTagKind() == TTK_Class,
Access, TInfo, EllipsisLoc);
}
// Base specifiers must be record types.
if (!BaseType->isRecordType()) {
Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
return nullptr;
}
// C++ [class.union]p1:
// A union shall not be used as a base class.
if (BaseType->isUnionType()) {
Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
return nullptr;
}
// For the MS ABI, propagate DLL attributes to base class templates.
if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
if (Attr *ClassAttr = getDLLAttr(Class)) {
if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
BaseType->getAsCXXRecordDecl())) {
propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate,
BaseLoc);
}
}
}
// C++ [class.derived]p2:
// The class-name in a base-specifier shall not be an incompletely
// defined class.
if (RequireCompleteType(BaseLoc, BaseType,
diag::err_incomplete_base_class, SpecifierRange)) {
Class->setInvalidDecl();
return nullptr;
}
// If the base class is polymorphic or isn't empty, the new one is/isn't, too.
RecordDecl *BaseDecl = BaseType->castAs<RecordType>()->getDecl();
assert(BaseDecl && "Record type has no declaration");
BaseDecl = BaseDecl->getDefinition();
assert(BaseDecl && "Base type is not incomplete, but has no definition");
CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
assert(CXXBaseDecl && "Base type is not a C++ type");
// Microsoft docs say:
// "If a base-class has a code_seg attribute, derived classes must have the
// same attribute."
const auto *BaseCSA = CXXBaseDecl->getAttr<CodeSegAttr>();
const auto *DerivedCSA = Class->getAttr<CodeSegAttr>();
if ((DerivedCSA || BaseCSA) &&
(!BaseCSA || !DerivedCSA || BaseCSA->getName() != DerivedCSA->getName())) {
Diag(Class->getLocation(), diag::err_mismatched_code_seg_base);
Diag(CXXBaseDecl->getLocation(), diag::note_base_class_specified_here)
<< CXXBaseDecl;
return nullptr;
}
// A class which contains a flexible array member is not suitable for use as a
// base class:
// - If the layout determines that a base comes before another base,
// the flexible array member would index into the subsequent base.
// - If the layout determines that base comes before the derived class,
// the flexible array member would index into the derived class.
if (CXXBaseDecl->hasFlexibleArrayMember()) {
Diag(BaseLoc, diag::err_base_class_has_flexible_array_member)
<< CXXBaseDecl->getDeclName();
return nullptr;
}
// C++ [class]p3:
// If a class is marked final and it appears as a base-type-specifier in
// base-clause, the program is ill-formed.
if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
<< CXXBaseDecl->getDeclName()
<< FA->isSpelledAsSealed();
Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at)
<< CXXBaseDecl->getDeclName() << FA->getRange();
return nullptr;
}
if (BaseDecl->isInvalidDecl())
Class->setInvalidDecl();
// Create the base specifier.
return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
Class->getTagKind() == TTK_Class,
Access, TInfo, EllipsisLoc);
}
/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
/// one entry in the base class list of a class specifier, for
/// example:
/// class foo : public bar, virtual private baz {
/// 'public bar' and 'virtual private baz' are each base-specifiers.
BaseResult
Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
ParsedAttributes &Attributes,
bool Virtual, AccessSpecifier Access,
ParsedType basetype, SourceLocation BaseLoc,
SourceLocation EllipsisLoc) {
if (!classdecl)
return true;
AdjustDeclIfTemplate(classdecl);
CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
if (!Class)
return true;
// We haven't yet attached the base specifiers.
Class->setIsParsingBaseSpecifiers();
// We do not support any C++11 attributes on base-specifiers yet.
// Diagnose any attributes we see.
for (const ParsedAttr &AL : Attributes) {
if (AL.isInvalid() || AL.getKind() == ParsedAttr::IgnoredAttribute)
continue;
Diag(AL.getLoc(), AL.getKind() == ParsedAttr::UnknownAttribute
? (unsigned)diag::warn_unknown_attribute_ignored
: (unsigned)diag::err_base_specifier_attribute)
<< AL << AL.getRange();
}
TypeSourceInfo *TInfo = nullptr;
GetTypeFromParser(basetype, &TInfo);
if (EllipsisLoc.isInvalid() &&
DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
UPPC_BaseType))
return true;
if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
Virtual, Access, TInfo,
EllipsisLoc))
return BaseSpec;
else
Class->setInvalidDecl();
return true;
}
/// Use small set to collect indirect bases. As this is only used
/// locally, there's no need to abstract the small size parameter.
typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet;
/// Recursively add the bases of Type. Don't add Type itself.
static void
NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set,
const QualType &Type)
{
// Even though the incoming type is a base, it might not be
// a class -- it could be a template parm, for instance.
if (auto Rec = Type->getAs<RecordType>()) {
auto Decl = Rec->getAsCXXRecordDecl();
// Iterate over its bases.
for (const auto &BaseSpec : Decl->bases()) {
QualType Base = Context.getCanonicalType(BaseSpec.getType())
.getUnqualifiedType();
if (Set.insert(Base).second)
// If we've not already seen it, recurse.
NoteIndirectBases(Context, Set, Base);
}
}
}
/// Performs the actual work of attaching the given base class
/// specifiers to a C++ class.
bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class,
MutableArrayRef<CXXBaseSpecifier *> Bases) {
if (Bases.empty())
return false;
// Used to keep track of which base types we have already seen, so
// that we can properly diagnose redundant direct base types. Note
// that the key is always the unqualified canonical type of the base
// class.
std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
// Used to track indirect bases so we can see if a direct base is
// ambiguous.
IndirectBaseSet IndirectBaseTypes;
// Copy non-redundant base specifiers into permanent storage.
unsigned NumGoodBases = 0;
bool Invalid = false;
for (unsigned idx = 0; idx < Bases.size(); ++idx) {
QualType NewBaseType
= Context.getCanonicalType(Bases[idx]->getType());
NewBaseType = NewBaseType.getLocalUnqualifiedType();
CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
if (KnownBase) {
// C++ [class.mi]p3:
// A class shall not be specified as a direct base class of a
// derived class more than once.
Diag(Bases[idx]->getBeginLoc(), diag::err_duplicate_base_class)
<< KnownBase->getType() << Bases[idx]->getSourceRange();
// Delete the duplicate base class specifier; we're going to
// overwrite its pointer later.
Context.Deallocate(Bases[idx]);
Invalid = true;
} else {
// Okay, add this new base class.
KnownBase = Bases[idx];
Bases[NumGoodBases++] = Bases[idx];
if (NewBaseType->isDependentType())
continue;
// Note this base's direct & indirect bases, if there could be ambiguity.
if (Bases.size() > 1)
NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType);
if (const RecordType *Record = NewBaseType->getAs<RecordType>()) {
const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
if (Class->isInterface() &&
(!RD->isInterfaceLike() ||
KnownBase->getAccessSpecifier() != AS_public)) {
// The Microsoft extension __interface does not permit bases that
// are not themselves public interfaces.
Diag(KnownBase->getBeginLoc(), diag::err_invalid_base_in_interface)
<< getRecordDiagFromTagKind(RD->getTagKind()) << RD
<< RD->getSourceRange();
Invalid = true;
}
if (RD->hasAttr<WeakAttr>())
Class->addAttr(WeakAttr::CreateImplicit(Context));
}
}
}
// Attach the remaining base class specifiers to the derived class.
Class->setBases(Bases.data(), NumGoodBases);
// Check that the only base classes that are duplicate are virtual.
for (unsigned idx = 0; idx < NumGoodBases; ++idx) {
// Check whether this direct base is inaccessible due to ambiguity.
QualType BaseType = Bases[idx]->getType();
// Skip all dependent types in templates being used as base specifiers.
// Checks below assume that the base specifier is a CXXRecord.
if (BaseType->isDependentType())
continue;
CanQualType CanonicalBase = Context.getCanonicalType(BaseType)
.getUnqualifiedType();
if (IndirectBaseTypes.count(CanonicalBase)) {
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
/*DetectVirtual=*/true);
bool found
= Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths);
assert(found);
(void)found;
if (Paths.isAmbiguous(CanonicalBase))
Diag(Bases[idx]->getBeginLoc(), diag::warn_inaccessible_base_class)
<< BaseType << getAmbiguousPathsDisplayString(Paths)
<< Bases[idx]->getSourceRange();
else
assert(Bases[idx]->isVirtual());
}
// Delete the base class specifier, since its data has been copied
// into the CXXRecordDecl.
Context.Deallocate(Bases[idx]);
}
return Invalid;
}
/// ActOnBaseSpecifiers - Attach the given base specifiers to the
/// class, after checking whether there are any duplicate base
/// classes.
void Sema::ActOnBaseSpecifiers(Decl *ClassDecl,
MutableArrayRef<CXXBaseSpecifier *> Bases) {
if (!ClassDecl || Bases.empty())
return;
AdjustDeclIfTemplate(ClassDecl);
AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases);
}
/// Determine whether the type \p Derived is a C++ class that is
/// derived from the type \p Base.
bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base) {
if (!getLangOpts().CPlusPlus)
return false;
CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
if (!DerivedRD)
return false;
CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
if (!BaseRD)
return false;
// If either the base or the derived type is invalid, don't try to
// check whether one is derived from the other.
if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
return false;
// FIXME: In a modules build, do we need the entire path to be visible for us
// to be able to use the inheritance relationship?
if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
return false;
return DerivedRD->isDerivedFrom(BaseRD);
}
/// Determine whether the type \p Derived is a C++ class that is
/// derived from the type \p Base.
bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base,
CXXBasePaths &Paths) {
if (!getLangOpts().CPlusPlus)
return false;
CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
if (!DerivedRD)
return false;
CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
if (!BaseRD)
return false;
if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
return false;
return DerivedRD->isDerivedFrom(BaseRD, Paths);
}
static void BuildBasePathArray(const CXXBasePath &Path,
CXXCastPath &BasePathArray) {
// We first go backward and check if we have a virtual base.
// FIXME: It would be better if CXXBasePath had the base specifier for
// the nearest virtual base.
unsigned Start = 0;
for (unsigned I = Path.size(); I != 0; --I) {
if (Path[I - 1].Base->isVirtual()) {
Start = I - 1;
break;
}
}
// Now add all bases.
for (unsigned I = Start, E = Path.size(); I != E; ++I)
BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
}
void Sema::BuildBasePathArray(const CXXBasePaths &Paths,
CXXCastPath &BasePathArray) {
assert(BasePathArray.empty() && "Base path array must be empty!");
assert(Paths.isRecordingPaths() && "Must record paths!");
return ::BuildBasePathArray(Paths.front(), BasePathArray);
}
/// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
/// conversion (where Derived and Base are class types) is
/// well-formed, meaning that the conversion is unambiguous (and
/// that all of the base classes are accessible). Returns true
/// and emits a diagnostic if the code is ill-formed, returns false
/// otherwise. Loc is the location where this routine should point to
/// if there is an error, and Range is the source range to highlight
/// if there is an error.
///
/// If either InaccessibleBaseID or AmbiguousBaseConvID are 0, then the
/// diagnostic for the respective type of error will be suppressed, but the
/// check for ill-formed code will still be performed.
bool
Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
unsigned InaccessibleBaseID,
unsigned AmbiguousBaseConvID,
SourceLocation Loc, SourceRange Range,
DeclarationName Name,
CXXCastPath *BasePath,
bool IgnoreAccess) {
// First, determine whether the path from Derived to Base is
// ambiguous. This is slightly more expensive than checking whether
// the Derived to Base conversion exists, because here we need to
// explore multiple paths to determine if there is an ambiguity.
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
/*DetectVirtual=*/false);
bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
if (!DerivationOkay)
return true;
const CXXBasePath *Path = nullptr;
if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType()))
Path = &Paths.front();
// For MSVC compatibility, check if Derived directly inherits from Base. Clang
// warns about this hierarchy under -Winaccessible-base, but MSVC allows the
// user to access such bases.
if (!Path && getLangOpts().MSVCCompat) {
for (const CXXBasePath &PossiblePath : Paths) {
if (PossiblePath.size() == 1) {
Path = &PossiblePath;
if (AmbiguousBaseConvID)
Diag(Loc, diag::ext_ms_ambiguous_direct_base)
<< Base << Derived << Range;
break;
}
}
}
if (Path) {
if (!IgnoreAccess) {
// Check that the base class can be accessed.
switch (
CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) {
case AR_inaccessible:
return true;
case AR_accessible:
case AR_dependent:
case AR_delayed:
break;
}
}
// Build a base path if necessary.
if (BasePath)
::BuildBasePathArray(*Path, *BasePath);
return false;
}
if (AmbiguousBaseConvID) {
// We know that the derived-to-base conversion is ambiguous, and
// we're going to produce a diagnostic. Perform the derived-to-base
// search just one more time to compute all of the possible paths so
// that we can print them out. This is more expensive than any of
// the previous derived-to-base checks we've done, but at this point
// performance isn't as much of an issue.
Paths.clear();
Paths.setRecordingPaths(true);
bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
assert(StillOkay && "Can only be used with a derived-to-base conversion");
(void)StillOkay;
// Build up a textual representation of the ambiguous paths, e.g.,
// D -> B -> A, that will be used to illustrate the ambiguous
// conversions in the diagnostic. We only print one of the paths
// to each base class subobject.
std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
Diag(Loc, AmbiguousBaseConvID)
<< Derived << Base << PathDisplayStr << Range << Name;
}
return true;
}
bool
Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
SourceLocation Loc, SourceRange Range,
CXXCastPath *BasePath,
bool IgnoreAccess) {
return CheckDerivedToBaseConversion(
Derived, Base, diag::err_upcast_to_inaccessible_base,
diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(),
BasePath, IgnoreAccess);
}
/// Builds a string representing ambiguous paths from a
/// specific derived class to different subobjects of the same base
/// class.
///
/// This function builds a string that can be used in error messages
/// to show the different paths that one can take through the
/// inheritance hierarchy to go from the derived class to different
/// subobjects of a base class. The result looks something like this:
/// @code
/// struct D -> struct B -> struct A
/// struct D -> struct C -> struct A
/// @endcode
std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
std::string PathDisplayStr;
std::set<unsigned> DisplayedPaths;
for (CXXBasePaths::paths_iterator Path = Paths.begin();
Path != Paths.end(); ++Path) {
if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
// We haven't displayed a path to this particular base
// class subobject yet.
PathDisplayStr += "\n ";
PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
for (CXXBasePath::const_iterator Element = Path->begin();
Element != Path->end(); ++Element)
PathDisplayStr += " -> " + Element->Base->getType().getAsString();
}
}
return PathDisplayStr;
}
//===----------------------------------------------------------------------===//
// C++ class member Handling
//===----------------------------------------------------------------------===//
/// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
bool Sema::ActOnAccessSpecifier(AccessSpecifier Access, SourceLocation ASLoc,
SourceLocation ColonLoc,
const ParsedAttributesView &Attrs) {
assert(Access != AS_none && "Invalid kind for syntactic access specifier!");
AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
ASLoc, ColonLoc);
CurContext->addHiddenDecl(ASDecl);
return ProcessAccessDeclAttributeList(ASDecl, Attrs);
}
/// CheckOverrideControl - Check C++11 override control semantics.
void Sema::CheckOverrideControl(NamedDecl *D) {
if (D->isInvalidDecl())
return;
// We only care about "override" and "final" declarations.
if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>())
return;
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
// We can't check dependent instance methods.
if (MD && MD->isInstance() &&
(MD->getParent()->hasAnyDependentBases() ||
MD->getType()->isDependentType()))
return;
if (MD && !MD->isVirtual()) {
// If we have a non-virtual method, check if if hides a virtual method.
// (In that case, it's most likely the method has the wrong type.)
SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
FindHiddenVirtualMethods(MD, OverloadedMethods);
if (!OverloadedMethods.empty()) {
if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
Diag(OA->getLocation(),
diag::override_keyword_hides_virtual_member_function)
<< "override" << (OverloadedMethods.size() > 1);
} else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
Diag(FA->getLocation(),
diag::override_keyword_hides_virtual_member_function)
<< (FA->isSpelledAsSealed() ? "sealed" : "final")
<< (OverloadedMethods.size() > 1);
}
NoteHiddenVirtualMethods(MD, OverloadedMethods);
MD->setInvalidDecl();
return;
}
// Fall through into the general case diagnostic.
// FIXME: We might want to attempt typo correction here.
}
if (!MD || !MD->isVirtual()) {
if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
Diag(OA->getLocation(),
diag::override_keyword_only_allowed_on_virtual_member_functions)
<< "override" << FixItHint::CreateRemoval(OA->getLocation());
D->dropAttr<OverrideAttr>();
}
if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
Diag(FA->getLocation(),
diag::override_keyword_only_allowed_on_virtual_member_functions)
<< (FA->isSpelledAsSealed() ? "sealed" : "final")
<< FixItHint::CreateRemoval(FA->getLocation());
D->dropAttr<FinalAttr>();
}
return;
}
// C++11 [class.virtual]p5:
// If a function is marked with the virt-specifier override and
// does not override a member function of a base class, the program is
// ill-formed.
bool HasOverriddenMethods = MD->size_overridden_methods() != 0;
if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
<< MD->getDeclName();
}
void Sema::DiagnoseAbsenceOfOverrideControl(NamedDecl *D, bool Inconsistent) {
if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>())
return;
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>())
return;
SourceLocation Loc = MD->getLocation();
SourceLocation SpellingLoc = Loc;
if (getSourceManager().isMacroArgExpansion(Loc))
SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).getBegin();
SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc);
if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc))
return;
if (MD->size_overridden_methods() > 0) {
auto EmitDiag = [&](unsigned DiagInconsistent, unsigned DiagSuggest) {
unsigned DiagID =
Inconsistent && !Diags.isIgnored(DiagInconsistent, MD->getLocation())
? DiagInconsistent
: DiagSuggest;
Diag(MD->getLocation(), DiagID) << MD->getDeclName();
const CXXMethodDecl *OMD = *MD->begin_overridden_methods();
Diag(OMD->getLocation(), diag::note_overridden_virtual_function);
};
if (isa<CXXDestructorDecl>(MD))
EmitDiag(
diag::warn_inconsistent_destructor_marked_not_override_overriding,
diag::warn_suggest_destructor_marked_not_override_overriding);
else
EmitDiag(diag::warn_inconsistent_function_marked_not_override_overriding,
diag::warn_suggest_function_marked_not_override_overriding);
}
}
/// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
/// function overrides a virtual member function marked 'final', according to
/// C++11 [class.virtual]p4.
bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
const CXXMethodDecl *Old) {
FinalAttr *FA = Old->getAttr<FinalAttr>();
if (!FA)
return false;
Diag(New->getLocation(), diag::err_final_function_overridden)
<< New->getDeclName()
<< FA->isSpelledAsSealed();
Diag(Old->getLocation(), diag::note_overridden_virtual_function);
return true;
}
static bool InitializationHasSideEffects(const FieldDecl &FD) {
const Type *T = FD.getType()->getBaseElementTypeUnsafe();
// FIXME: Destruction of ObjC lifetime types has side-effects.
if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
return !RD->isCompleteDefinition() ||
!RD->hasTrivialDefaultConstructor() ||
!RD->hasTrivialDestructor();
return false;
}
static const ParsedAttr *getMSPropertyAttr(const ParsedAttributesView &list) {
ParsedAttributesView::const_iterator Itr =
llvm::find_if(list, [](const ParsedAttr &AL) {
return AL.isDeclspecPropertyAttribute();
});
if (Itr != list.end())
return &*Itr;
return nullptr;
}
// Check if there is a field shadowing.
void Sema::CheckShadowInheritedFields(const SourceLocation &Loc,
DeclarationName FieldName,
const CXXRecordDecl *RD,
bool DeclIsField) {
if (Diags.isIgnored(diag::warn_shadow_field, Loc))
return;
// To record a shadowed field in a base
std::map<CXXRecordDecl*, NamedDecl*> Bases;
auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier,
CXXBasePath &Path) {
const auto Base = Specifier->getType()->getAsCXXRecordDecl();
// Record an ambiguous path directly
if (Bases.find(Base) != Bases.end())
return true;
for (const auto Field : Base->lookup(FieldName)) {
if ((isa<FieldDecl>(Field) || isa<IndirectFieldDecl>(Field)) &&
Field->getAccess() != AS_private) {
assert(Field->getAccess() != AS_none);
assert(Bases.find(Base) == Bases.end());
Bases[Base] = Field;
return true;
}
}
return false;
};
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
/*DetectVirtual=*/true);
if (!RD->lookupInBases(FieldShadowed, Paths))
return;
for (const auto &P : Paths) {
auto Base = P.back().Base->getType()->getAsCXXRecordDecl();
auto It = Bases.find(Base);
// Skip duplicated bases
if (It == Bases.end())
continue;
auto BaseField = It->second;
assert(BaseField->getAccess() != AS_private);
if (AS_none !=
CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) {
Diag(Loc, diag::warn_shadow_field)
<< FieldName << RD << Base << DeclIsField;
Diag(BaseField->getLocation(), diag::note_shadow_field);
Bases.erase(It);
}
}
}
/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
/// bitfield width if there is one, 'InitExpr' specifies the initializer if
/// one has been parsed, and 'InitStyle' is set if an in-class initializer is
/// present (but parsing it has been deferred).
NamedDecl *
Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
MultiTemplateParamsArg TemplateParameterLists,
Expr *BW, const VirtSpecifiers &VS,
InClassInitStyle InitStyle) {
const DeclSpec &DS = D.getDeclSpec();
DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
DeclarationName Name = NameInfo.getName();
SourceLocation Loc = NameInfo.getLoc();
// For anonymous bitfields, the location should point to the type.
if (Loc.isInvalid())
Loc = D.getBeginLoc();
Expr *BitWidth = static_cast<Expr*>(BW);
assert(isa<CXXRecordDecl>(CurContext));
assert(!DS.isFriendSpecified());
bool isFunc = D.isDeclarationOfFunction();
const ParsedAttr *MSPropertyAttr =
getMSPropertyAttr(D.getDeclSpec().getAttributes());
if (cast<CXXRecordDecl>(CurContext)->isInterface()) {
// The Microsoft extension __interface only permits public member functions
// and prohibits constructors, destructors, operators, non-public member
// functions, static methods and data members.
unsigned InvalidDecl;
bool ShowDeclName = true;
if (!isFunc &&
(DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr))
InvalidDecl = 0;
else if (!isFunc)
InvalidDecl = 1;
else if (AS != AS_public)
InvalidDecl = 2;
else if (DS.getStorageClassSpec() == DeclSpec::SCS_static)
InvalidDecl = 3;
else switch (Name.getNameKind()) {
case DeclarationName::CXXConstructorName:
InvalidDecl = 4;
ShowDeclName = false;
break;
case DeclarationName::CXXDestructorName:
InvalidDecl = 5;
ShowDeclName = false;
break;
case DeclarationName::CXXOperatorName:
case DeclarationName::CXXConversionFunctionName:
InvalidDecl = 6;
break;
default:
InvalidDecl = 0;
break;
}
if (InvalidDecl) {
if (ShowDeclName)
Diag(Loc, diag::err_invalid_member_in_interface)
<< (InvalidDecl-1) << Name;
else
Diag(Loc, diag::err_invalid_member_in_interface)
<< (InvalidDecl-1) << "";
return nullptr;
}
}
// C++ 9.2p6: A member shall not be declared to have automatic storage
// duration (auto, register) or with the extern storage-class-specifier.
// C++ 7.1.1p8: The mutable specifier can be applied only to names of class
// data members and cannot be applied to names declared const or static,
// and cannot be applied to reference members.
switch (DS.getStorageClassSpec()) {
case DeclSpec::SCS_unspecified:
case DeclSpec::SCS_typedef:
case DeclSpec::SCS_static:
break;
case DeclSpec::SCS_mutable:
if (isFunc) {
Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
// FIXME: It would be nicer if the keyword was ignored only for this
// declarator. Otherwise we could get follow-up errors.
D.getMutableDeclSpec().ClearStorageClassSpecs();
}
break;
default:
Diag(DS.getStorageClassSpecLoc(),
diag::err_storageclass_invalid_for_member);
D.getMutableDeclSpec().ClearStorageClassSpecs();
break;
}
bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
!isFunc);
if (DS.hasConstexprSpecifier() && isInstField) {
SemaDiagnosticBuilder B =
Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member);
SourceLocation ConstexprLoc = DS.getConstexprSpecLoc();
if (InitStyle == ICIS_NoInit) {
B << 0 << 0;
if (D.getDeclSpec().getTypeQualifiers() & DeclSpec::TQ_const)
B << FixItHint::CreateRemoval(ConstexprLoc);
else {
B << FixItHint::CreateReplacement(ConstexprLoc, "const");
D.getMutableDeclSpec().ClearConstexprSpec();
const char *PrevSpec;
unsigned DiagID;
bool Failed = D.getMutableDeclSpec().SetTypeQual(
DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts());
(void)Failed;
assert(!Failed && "Making a constexpr member const shouldn't fail");
}
} else {
B << 1;
const char *PrevSpec;
unsigned DiagID;
if (D.getMutableDeclSpec().SetStorageClassSpec(
*this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID,
Context.getPrintingPolicy())) {
assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable &&
"This is the only DeclSpec that should fail to be applied");
B << 1;
} else {
B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static ");
isInstField = false;
}
}
}
NamedDecl *Member;
if (isInstField) {
CXXScopeSpec &SS = D.getCXXScopeSpec();
// Data members must have identifiers for names.
if (!Name.isIdentifier()) {
Diag(Loc, diag::err_bad_variable_name)
<< Name;
return nullptr;
}
IdentifierInfo *II = Name.getAsIdentifierInfo();
// Member field could not be with "template" keyword.
// So TemplateParameterLists should be empty in this case.
if (TemplateParameterLists.size()) {
TemplateParameterList* TemplateParams = TemplateParameterLists[0];
if (TemplateParams->size()) {
// There is no such thing as a member field template.
Diag(D.getIdentifierLoc(), diag::err_template_member)
<< II
<< SourceRange(TemplateParams->getTemplateLoc(),
TemplateParams->getRAngleLoc());
} else {
// There is an extraneous 'template<>' for this member.
Diag(TemplateParams->getTemplateLoc(),
diag::err_template_member_noparams)
<< II
<< SourceRange(TemplateParams->getTemplateLoc(),
TemplateParams->getRAngleLoc());
}
return nullptr;
}
if (SS.isSet() && !SS.isInvalid()) {
// The user provided a superfluous scope specifier inside a class
// definition:
//
// class X {
// int X::member;
// };
if (DeclContext *DC = computeDeclContext(SS, false))
diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(),
D.getName().getKind() ==
UnqualifiedIdKind::IK_TemplateId);
else
Diag(D.getIdentifierLoc(), diag::err_member_qualification)
<< Name << SS.getRange();
SS.clear();
}
if (MSPropertyAttr) {
Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D,
BitWidth, InitStyle, AS, *MSPropertyAttr);
if (!Member)
return nullptr;
isInstField = false;
} else {
Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D,
BitWidth, InitStyle, AS);
if (!Member)
return nullptr;
}
CheckShadowInheritedFields(Loc, Name, cast<CXXRecordDecl>(CurContext));
} else {
Member = HandleDeclarator(S, D, TemplateParameterLists);
if (!Member)
return nullptr;
// Non-instance-fields can't have a bitfield.
if (BitWidth) {
if (Member->isInvalidDecl()) {
// don't emit another diagnostic.
} else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) {
// C++ 9.6p3: A bit-field shall not be a static member.
// "static member 'A' cannot be a bit-field"
Diag(Loc, diag::err_static_not_bitfield)
<< Name << BitWidth->getSourceRange();
} else if (isa<TypedefDecl>(Member)) {
// "typedef member 'x' cannot be a bit-field"
Diag(Loc, diag::err_typedef_not_bitfield)
<< Name << BitWidth->getSourceRange();
} else {
// A function typedef ("typedef int f(); f a;").
// C++ 9.6p3: A bit-field shall have integral or enumeration type.
Diag(Loc, diag::err_not_integral_type_bitfield)
<< Name << cast<ValueDecl>(Member)->getType()
<< BitWidth->getSourceRange();
}
BitWidth = nullptr;
Member->setInvalidDecl();
}
NamedDecl *NonTemplateMember = Member;
if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
NonTemplateMember = FunTmpl->getTemplatedDecl();
else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member))
NonTemplateMember = VarTmpl->getTemplatedDecl();
Member->setAccess(AS);
// If we have declared a member function template or static data member
// template, set the access of the templated declaration as well.
if (NonTemplateMember != Member)
NonTemplateMember->setAccess(AS);
// C++ [temp.deduct.guide]p3:
// A deduction guide [...] for a member class template [shall be
// declared] with the same access [as the template].
if (auto *DG = dyn_cast<CXXDeductionGuideDecl>(NonTemplateMember)) {
auto *TD = DG->getDeducedTemplate();
// Access specifiers are only meaningful if both the template and the
// deduction guide are from the same scope.
if (AS != TD->getAccess() &&
TD->getDeclContext()->getRedeclContext()->Equals(
DG->getDeclContext()->getRedeclContext())) {
Diag(DG->getBeginLoc(), diag::err_deduction_guide_wrong_access);
Diag(TD->getBeginLoc(), diag::note_deduction_guide_template_access)
<< TD->getAccess();
const AccessSpecDecl *LastAccessSpec = nullptr;
for (const auto *D : cast<CXXRecordDecl>(CurContext)->decls()) {
if (const auto *AccessSpec = dyn_cast<AccessSpecDecl>(D))
LastAccessSpec = AccessSpec;
}
assert(LastAccessSpec && "differing access with no access specifier");
Diag(LastAccessSpec->getBeginLoc(), diag::note_deduction_guide_access)
<< AS;
}
}
}
if (VS.isOverrideSpecified())
Member->addAttr(OverrideAttr::Create(Context, VS.getOverrideLoc(),
AttributeCommonInfo::AS_Keyword));
if (VS.isFinalSpecified())
Member->addAttr(FinalAttr::Create(
Context, VS.getFinalLoc(), AttributeCommonInfo::AS_Keyword,
static_cast<FinalAttr::Spelling>(VS.isFinalSpelledSealed())));
if (VS.getLastLocation().isValid()) {
// Update the end location of a method that has a virt-specifiers.
if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
MD->setRangeEnd(VS.getLastLocation());
}
CheckOverrideControl(Member);
assert((Name || isInstField) && "No identifier for non-field ?");
if (isInstField) {
FieldDecl *FD = cast<FieldDecl>(Member);
FieldCollector->Add(FD);
if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) {
// Remember all explicit private FieldDecls that have a name, no side
// effects and are not part of a dependent type declaration.
if (!FD->isImplicit() && FD->getDeclName() &&
FD->getAccess() == AS_private &&
!FD->hasAttr<UnusedAttr>() &&
!FD->getParent()->isDependentContext() &&
!InitializationHasSideEffects(*FD))
UnusedPrivateFields.insert(FD);
}
}
return Member;
}
namespace {
class UninitializedFieldVisitor
: public EvaluatedExprVisitor<UninitializedFieldVisitor> {
Sema &S;
// List of Decls to generate a warning on. Also remove Decls that become
// initialized.
llvm::SmallPtrSetImpl<ValueDecl*> &Decls;
// List of base classes of the record. Classes are removed after their
// initializers.
llvm::SmallPtrSetImpl<QualType> &BaseClasses;
// Vector of decls to be removed from the Decl set prior to visiting the
// nodes. These Decls may have been initialized in the prior initializer.
llvm::SmallVector<ValueDecl*, 4> DeclsToRemove;
// If non-null, add a note to the warning pointing back to the constructor.
const CXXConstructorDecl *Constructor;
// Variables to hold state when processing an initializer list. When
// InitList is true, special case initialization of FieldDecls matching
// InitListFieldDecl.
bool InitList;
FieldDecl *InitListFieldDecl;
llvm::SmallVector<unsigned, 4> InitFieldIndex;
public:
typedef EvaluatedExprVisitor<UninitializedFieldVisitor> Inherited;
UninitializedFieldVisitor(Sema &S,
llvm::SmallPtrSetImpl<ValueDecl*> &Decls,
llvm::SmallPtrSetImpl<QualType> &BaseClasses)
: Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses),
Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {}
// Returns true if the use of ME is not an uninitialized use.
bool IsInitListMemberExprInitialized(MemberExpr *ME,
bool CheckReferenceOnly) {
llvm::SmallVector<FieldDecl*, 4> Fields;
bool ReferenceField = false;
while (ME) {
FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
if (!FD)
return false;
Fields.push_back(FD);
if (FD->getType()->isReferenceType())
ReferenceField = true;
ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts());
}
// Binding a reference to an uninitialized field is not an
// uninitialized use.
if (CheckReferenceOnly && !ReferenceField)
return true;
llvm::SmallVector<unsigned, 4> UsedFieldIndex;
// Discard the first field since it is the field decl that is being
// initialized.
for (const FieldDecl *FD : llvm::drop_begin(llvm::reverse(Fields)))
UsedFieldIndex.push_back(FD->getFieldIndex());
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;
}
return false;
}
void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
bool AddressOf) {
if (isa<EnumConstantDecl>(ME->getMemberDecl()))
return;
// FieldME is the inner-most MemberExpr that is not an anonymous struct
// or union.
MemberExpr *FieldME = ME;
bool AllPODFields = FieldME->getType().isPODType(S.Context);
Expr *Base = ME;
while (MemberExpr *SubME =
dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) {
if (isa<VarDecl>(SubME->getMemberDecl()))
return;
if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
if (!FD->isAnonymousStructOrUnion())
FieldME = SubME;
if (!FieldME->getType().isPODType(S.Context))
AllPODFields = false;
Base = SubME->getBase();
}
if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts())) {
Visit(Base);
return;
}
if (AddressOf && AllPODFields)
return;
ValueDecl* FoundVD = FieldME->getMemberDecl();
if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {
BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr());
}
if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) {
QualType T = BaseCast->getType();
if (T->isPointerType() &&
BaseClasses.count(T->getPointeeType())) {
S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit)
<< T->getPointeeType() << FoundVD;
}
}
}
if (!Decls.count(FoundVD))
return;
const bool IsReference = FoundVD->getType()->isReferenceType();
if (InitList && !AddressOf && FoundVD == InitListFieldDecl) {
// Special checking for initializer lists.
if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) {
return;
}
} else {
// Prevent double warnings on use of unbounded references.
if (CheckReferenceOnly && !IsReference)
return;
}
unsigned diag = IsReference
? diag::warn_reference_field_is_uninit
: diag::warn_field_is_uninit;
S.Diag(FieldME->getExprLoc(), diag) << FoundVD;
if (Constructor)
S.Diag(Constructor->getLocation(),
diag::note_uninit_in_this_constructor)
<< (Constructor->isDefaultConstructor() && Constructor->isImplicit());
}
void HandleValue(Expr *E, bool AddressOf) {
E = E->IgnoreParens();
if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
HandleMemberExpr(ME, false /*CheckReferenceOnly*/,
AddressOf /*AddressOf*/);
return;
}
if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
Visit(CO->getCond());
HandleValue(CO->getTrueExpr(), AddressOf);
HandleValue(CO->getFalseExpr(), AddressOf);
return;
}
if (BinaryConditionalOperator *BCO =
dyn_cast<BinaryConditionalOperator>(E)) {
Visit(BCO->getCond());
HandleValue(BCO->getFalseExpr(), AddressOf);
return;
}
if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
HandleValue(OVE->getSourceExpr(), AddressOf);
return;
}
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
switch (BO->getOpcode()) {
default:
break;
case(BO_PtrMemD):
case(BO_PtrMemI):
HandleValue(BO->getLHS(), AddressOf);
Visit(BO->getRHS());
return;
case(BO_Comma):
Visit(BO->getLHS());
HandleValue(BO->getRHS(), AddressOf);
return;
}
}
Visit(E);
}
void CheckInitListExpr(InitListExpr *ILE) {
InitFieldIndex.push_back(0);
for (auto Child : ILE->children()) {
if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) {
CheckInitListExpr(SubList);
} else {
Visit(Child);
}
++InitFieldIndex.back();
}
InitFieldIndex.pop_back();
}
void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor,
FieldDecl *Field, const Type *BaseClass) {
// Remove Decls that may have been initialized in the previous
// initializer.
for (ValueDecl* VD : DeclsToRemove)
Decls.erase(VD);
DeclsToRemove.clear();
Constructor = FieldConstructor;
InitListExpr *ILE = dyn_cast<InitListExpr>(E);
if (ILE && Field) {
InitList = true;
InitListFieldDecl = Field;
InitFieldIndex.clear();
CheckInitListExpr(ILE);
} else {
InitList = false;
Visit(E);
}
if (Field)
Decls.erase(Field);
if (BaseClass)
BaseClasses.erase(BaseClass->getCanonicalTypeInternal());
}
void VisitMemberExpr(MemberExpr *ME) {
// All uses of unbounded reference fields will warn.
HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/);
}
void VisitImplicitCastExpr(ImplicitCastExpr *E) {
if (E->getCastKind() == CK_LValueToRValue) {
HandleValue(E->getSubExpr(), false /*AddressOf*/);
return;
}
Inherited::VisitImplicitCastExpr(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, false /*AddressOf*/);
return;
}
Inherited::VisitCXXConstructExpr(E);
}
void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
Expr *Callee = E->getCallee();
if (isa<MemberExpr>(Callee)) {
HandleValue(Callee, false /*AddressOf*/);
for (auto Arg : E->arguments())
Visit(Arg);
return;
}
Inherited::VisitCXXMemberCallExpr(E);
}
void VisitCallExpr(CallExpr *E) {
// Treat std::move as a use.
if (E->isCallToStdMove()) {
HandleValue(E->getArg(0), /*AddressOf=*/false);
return;
}
Inherited::VisitCallExpr(E);
}
void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
Expr *Callee = E->getCallee();
if (isa<UnresolvedLookupExpr>(Callee))
return Inherited::VisitCXXOperatorCallExpr(E);
Visit(Callee);
for (auto Arg : E->arguments())
HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/);
}
void VisitBinaryOperator(BinaryOperator *E) {
// If a field assignment is detected, remove the field from the
// uninitiailized field set.
if (E->getOpcode() == BO_Assign)
if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS()))
if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
if (!FD->getType()->isReferenceType())
DeclsToRemove.push_back(FD);
if (E->isCompoundAssignmentOp()) {
HandleValue(E->getLHS(), false /*AddressOf*/);
Visit(E->getRHS());
return;
}
Inherited::VisitBinaryOperator(E);
}
void VisitUnaryOperator(UnaryOperator *E) {
if (E->isIncrementDecrementOp()) {
HandleValue(E->getSubExpr(), false /*AddressOf*/);
return;
}
if (E->getOpcode() == UO_AddrOf) {
if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) {
HandleValue(ME->getBase(), true /*AddressOf*/);
return;
}
}
Inherited::VisitUnaryOperator(E);
}
};
// Diagnose value-uses of fields to initialize themselves, e.g.
// foo(foo)
// where foo is not also a parameter to the constructor.
// Also diagnose across field uninitialized use such as
// x(y), y(x)
// TODO: implement -Wuninitialized and fold this into that framework.
static void DiagnoseUninitializedFields(
Sema &SemaRef, const CXXConstructorDecl *Constructor) {
if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit,
Constructor->getLocation())) {
return;
}
if (Constructor->isInvalidDecl())
return;
const CXXRecordDecl *RD = Constructor->getParent();
if (RD->isDependentContext())
return;
// Holds fields that are uninitialized.
llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;
// At the beginning, all fields are uninitialized.
for (auto *I : RD->decls()) {
if (auto *FD = dyn_cast<FieldDecl>(I)) {
UninitializedFields.insert(FD);
} else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) {
UninitializedFields.insert(IFD->getAnonField());
}
}
llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses;
for (auto I : RD->bases())
UninitializedBaseClasses.insert(I.getType().getCanonicalType());
if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
return;
UninitializedFieldVisitor UninitializedChecker(SemaRef,
UninitializedFields,
UninitializedBaseClasses);
for (const auto *FieldInit : Constructor->inits()) {
if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
break;
Expr *InitExpr = FieldInit->getInit();
if (!InitExpr)
continue;
if (CXXDefaultInitExpr *Default =
dyn_cast<CXXDefaultInitExpr>(InitExpr)) {
InitExpr = Default->getExpr();
if (!InitExpr)
continue;
// In class initializers will point to the constructor.
UninitializedChecker.CheckInitializer(InitExpr, Constructor,
FieldInit->getAnyMember(),
FieldInit->getBaseClass());
} else {
UninitializedChecker.CheckInitializer(InitExpr, nullptr,
FieldInit->getAnyMember(),
FieldInit->getBaseClass());
}
}
}
} // namespace
/// Enter a new C++ default initializer scope. After calling this, the
/// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if
/// parsing or instantiating the initializer failed.
void Sema::ActOnStartCXXInClassMemberInitializer() {
// Create a synthetic function scope to represent the call to the constructor
// that notionally surrounds a use of this initializer.
PushFunctionScope();
}
void Sema::ActOnStartTrailingRequiresClause(Scope *S, Declarator &D) {
if (!D.isFunctionDeclarator())
return;
auto &FTI = D.getFunctionTypeInfo();
if (!FTI.Params)
return;
for (auto &Param : ArrayRef<DeclaratorChunk::ParamInfo>(FTI.Params,
FTI.NumParams)) {
auto *ParamDecl = cast<NamedDecl>(Param.Param);
if (ParamDecl->getDeclName())
PushOnScopeChains(ParamDecl, S, /*AddToContext=*/false);
}
}
ExprResult Sema::ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr) {
return ActOnRequiresClause(ConstraintExpr);
}
ExprResult Sema::ActOnRequiresClause(ExprResult ConstraintExpr) {
if (ConstraintExpr.isInvalid())
return ExprError();
ConstraintExpr = CorrectDelayedTyposInExpr(ConstraintExpr);
if (ConstraintExpr.isInvalid())
return ExprError();
if (DiagnoseUnexpandedParameterPack(ConstraintExpr.get(),
UPPC_RequiresClause))
return ExprError();
return ConstraintExpr;
}
/// This is invoked after parsing an in-class initializer for a
/// non-static C++ class member, and after instantiating an in-class initializer
/// in a class template. Such actions are deferred until the class is complete.
void Sema::ActOnFinishCXXInClassMemberInitializer(Decl *D,
SourceLocation InitLoc,
Expr *InitExpr) {
// Pop the notional constructor scope we created earlier.
PopFunctionScopeInfo(nullptr, D);
FieldDecl *FD = dyn_cast<FieldDecl>(D);
assert((isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) &&
"must set init style when field is created");
if (!InitExpr) {
D->setInvalidDecl();
if (FD)
FD->removeInClassInitializer();
return;
}
if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
FD->setInvalidDecl();
FD->removeInClassInitializer();
return;
}
ExprResult Init = InitExpr;
if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
InitializedEntity Entity =
InitializedEntity::InitializeMemberFromDefaultMemberInitializer(FD);
InitializationKind Kind =
FD->getInClassInitStyle() == ICIS_ListInit
? InitializationKind::CreateDirectList(InitExpr->getBeginLoc(),
InitExpr->getBeginLoc(),
InitExpr->getEndLoc())
: InitializationKind::CreateCopy(InitExpr->getBeginLoc(), InitLoc);
InitializationSequence Seq(*this, Entity, Kind, InitExpr);
Init = Seq.Perform(*this, Entity, Kind, InitExpr);
if (Init.isInvalid()) {
FD->setInvalidDecl();
return;
}
}
// C++11 [class.base.init]p7:
// The initialization of each base and member constitutes a
// full-expression.
Init = ActOnFinishFullExpr(Init.get(), InitLoc, /*DiscardedValue*/ false);
if (Init.isInvalid()) {
FD->setInvalidDecl();
return;
}
InitExpr = Init.get();
FD->setInClassInitializer(InitExpr);
}
/// Find the direct and/or virtual base specifiers that
/// correspond to the given base type, for use in base initialization
/// within a constructor.
static bool FindBaseInitializer(Sema &SemaRef,
CXXRecordDecl *ClassDecl,
QualType BaseType,
const CXXBaseSpecifier *&DirectBaseSpec,
const CXXBaseSpecifier *&VirtualBaseSpec) {
// First, check for a direct base class.
DirectBaseSpec = nullptr;
for (const auto &Base : ClassDecl->bases()) {
if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) {
// We found a direct base of this type. That's what we're
// initializing.
DirectBaseSpec = &Base;
break;
}
}
// Check for a virtual base class.
// FIXME: We might be able to short-circuit this if we know in advance that
// there are no virtual bases.
VirtualBaseSpec = nullptr;
if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
// We haven't found a base yet; search the class hierarchy for a
// virtual base class.
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
/*DetectVirtual=*/false);
if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
SemaRef.Context.getTypeDeclType(ClassDecl),
BaseType, Paths)) {
for (CXXBasePaths::paths_iterator Path = Paths.begin();
Path != Paths.end(); ++Path) {
if (Path->back().Base->isVirtual()) {
VirtualBaseSpec = Path->back().Base;
break;
}
}
}
}
return DirectBaseSpec || VirtualBaseSpec;
}
/// Handle a C++ member initializer using braced-init-list syntax.
MemInitResult
Sema::ActOnMemInitializer(Decl *ConstructorD,
Scope *S,
CXXScopeSpec &SS,
IdentifierInfo *MemberOrBase,
ParsedType TemplateTypeTy,
const DeclSpec &DS,
SourceLocation IdLoc,
Expr *InitList,
SourceLocation EllipsisLoc) {
return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
DS, IdLoc, InitList,
EllipsisLoc);
}
/// Handle a C++ member initializer using parentheses syntax.
MemInitResult
Sema::ActOnMemInitializer(Decl *ConstructorD,
Scope *S,
CXXScopeSpec &SS,
IdentifierInfo *MemberOrBase,
ParsedType TemplateTypeTy,
const DeclSpec &DS,
SourceLocation IdLoc,
SourceLocation LParenLoc,
ArrayRef<Expr *> Args,
SourceLocation RParenLoc,
SourceLocation EllipsisLoc) {
Expr *List = ParenListExpr::Create(Context, LParenLoc, Args, RParenLoc);
return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
DS, IdLoc, List, EllipsisLoc);
}
namespace {
// Callback to only accept typo corrections that can be a valid C++ member
// initializer: either a non-static field member or a base class.
class MemInitializerValidatorCCC final : public CorrectionCandidateCallback {
public:
explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
: ClassDecl(ClassDecl) {}
bool ValidateCandidate(const TypoCorrection &candidate) override {
if (NamedDecl *ND = candidate.getCorrectionDecl()) {
if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
return isa<TypeDecl>(ND);
}
return false;
}
std::unique_ptr<CorrectionCandidateCallback> clone() override {
return std::make_unique<MemInitializerValidatorCCC>(*this);
}
private:
CXXRecordDecl *ClassDecl;
};
}
ValueDecl *Sema::tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl,
CXXScopeSpec &SS,
ParsedType TemplateTypeTy,
IdentifierInfo *MemberOrBase) {
if (SS.getScopeRep() || TemplateTypeTy)
return nullptr;
for (auto *D : ClassDecl->lookup(MemberOrBase))
if (isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D))
return cast<ValueDecl>(D);
return nullptr;
}
/// Handle a C++ member initializer.
MemInitResult
Sema::BuildMemInitializer(Decl *ConstructorD,
Scope *S,
CXXScopeSpec &SS,
IdentifierInfo *MemberOrBase,
ParsedType TemplateTypeTy,
const DeclSpec &DS,
SourceLocation IdLoc,
Expr *Init,
SourceLocation EllipsisLoc) {
ExprResult Res = CorrectDelayedTyposInExpr(Init, /*InitDecl=*/nullptr,
/*RecoverUncorrectedTypos=*/true);
if (!Res.isUsable())
return true;
Init = Res.get();
if (!ConstructorD)
return true;
AdjustDeclIfTemplate(ConstructorD);
CXXConstructorDecl *Constructor
= dyn_cast<CXXConstructorDecl>(ConstructorD);
if (!Constructor) {
// The user wrote a constructor initializer on a function that is
// not a C++ constructor. Ignore the error for now, because we may
// have more member initializers coming; we'll diagnose it just
// once in ActOnMemInitializers.
return true;
}
CXXRecordDecl *ClassDecl = Constructor->getParent();
// C++ [class.base.init]p2:
// Names in a mem-initializer-id are looked up in the scope of the
// constructor's class and, if not found in that scope, are looked
// up in the scope containing the constructor's definition.
// [Note: if the constructor's class contains a member with the
// same name as a direct or virtual base class of the class, a
// mem-initializer-id naming the member or base class and composed
// of a single identifier refers to the class member. A
// mem-initializer-id for the hidden base class may be specified
// using a qualified name. ]
// Look for a member, first.
if (ValueDecl *Member = tryLookupCtorInitMemberDecl(
ClassDecl, SS, TemplateTypeTy, MemberOrBase)) {
if (EllipsisLoc.isValid())
Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
<< MemberOrBase
<< SourceRange(IdLoc, Init->getSourceRange().getEnd());
return BuildMemberInitializer(Member, Init, IdLoc);
}
// It didn't name a member, so see if it names a class.
QualType BaseType;
TypeSourceInfo *TInfo = nullptr;
if (TemplateTypeTy) {
BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
if (BaseType.isNull())
return true;
} else if (DS.getTypeSpecType() == TST_decltype) {
BaseType = BuildDecltypeType(DS.getRepAsExpr());
} else if (DS.getTypeSpecType() == TST_decltype_auto) {
Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
return true;
} else {
LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
LookupParsedName(R, S, &SS);
TypeDecl *TyD = R.getAsSingle<TypeDecl>();
if (!TyD) {
if (R.isAmbiguous()) return true;
// We don't want access-control diagnostics here.
R.suppressDiagnostics();
if (SS.isSet() && isDependentScopeSpecifier(SS)) {
bool NotUnknownSpecialization = false;
DeclContext *DC = computeDeclContext(SS, false);
if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
NotUnknownSpecialization = !Record->hasAnyDependentBases();
if (!NotUnknownSpecialization) {
// When the scope specifier can refer to a member of an unknown
// specialization, we take it as a type name.
BaseType = CheckTypenameType(ETK_None, SourceLocation(),
SS.getWithLocInContext(Context),
*MemberOrBase, IdLoc);
if (BaseType.isNull())
return true;
TInfo = Context.CreateTypeSourceInfo(BaseType);
DependentNameTypeLoc TL =
TInfo->getTypeLoc().castAs<DependentNameTypeLoc>();
if (!TL.isNull()) {
TL.setNameLoc(IdLoc);
TL.setElaboratedKeywordLoc(SourceLocation());
TL.setQualifierLoc(SS.getWithLocInContext(Context));
}
R.clear();
R.setLookupName(MemberOrBase);
}
}
// If no results were found, try to correct typos.
TypoCorrection Corr;
MemInitializerValidatorCCC CCC(ClassDecl);
if (R.empty() && BaseType.isNull() &&
(Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
CCC, CTK_ErrorRecovery, ClassDecl))) {
if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
// We have found a non-static data member with a similar
// name to what was typed; complain and initialize that
// member.
diagnoseTypo(Corr,
PDiag(diag::err_mem_init_not_member_or_class_suggest)
<< MemberOrBase << true);
return BuildMemberInitializer(Member, Init, IdLoc);
} else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
const CXXBaseSpecifier *DirectBaseSpec;
const CXXBaseSpecifier *VirtualBaseSpec;
if (FindBaseInitializer(*this, ClassDecl,
Context.getTypeDeclType(Type),
DirectBaseSpec, VirtualBaseSpec)) {
// We have found a direct or virtual base class with a
// similar name to what was typed; complain and initialize
// that base class.
diagnoseTypo(Corr,
PDiag(diag::err_mem_init_not_member_or_class_suggest)
<< MemberOrBase << false,
PDiag() /*Suppress note, we provide our own.*/);
const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec
: VirtualBaseSpec;
Diag(BaseSpec->getBeginLoc(), diag::note_base_class_specified_here)
<< BaseSpec->getType() << BaseSpec->getSourceRange();
TyD = Type;
}
}
}
if (!TyD && BaseType.isNull()) {
Diag(IdLoc, diag::err_mem_init_not_member_or_class)
<< MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
return true;
}
}
if (BaseType.isNull()) {
BaseType = Context.getTypeDeclType(TyD);
MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false);
if (SS.isSet()) {
BaseType = Context.getElaboratedType(ETK_None, SS.getScopeRep(),
BaseType);
TInfo = Context.CreateTypeSourceInfo(BaseType);
ElaboratedTypeLoc TL = TInfo->getTypeLoc().castAs<ElaboratedTypeLoc>();
TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
TL.setElaboratedKeywordLoc(SourceLocation());
TL.setQualifierLoc(SS.getWithLocInContext(Context));
}
}
}
if (!TInfo)
TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
}
MemInitResult
Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
SourceLocation IdLoc) {
FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
assert((DirectMember || IndirectMember) &&
"Member must be a FieldDecl or IndirectFieldDecl");
if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
return true;
if (Member->isInvalidDecl())
return true;
MultiExprArg Args;
if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
} else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
} else {
// Template instantiation doesn't reconstruct ParenListExprs for us.
Args = Init;
}
SourceRange InitRange = Init->getSourceRange();
if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
// Can't check initialization for a member of dependent type or when
// any of the arguments are type-dependent expressions.
DiscardCleanupsInEvaluationContext();
} else {
bool InitList = false;
if (isa<InitListExpr>(Init)) {
InitList = true;
Args = Init;
}
// Initialize the member.
InitializedEntity MemberEntity =
DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr)
: InitializedEntity::InitializeMember(IndirectMember,
nullptr);
InitializationKind Kind =
InitList ? InitializationKind::CreateDirectList(
IdLoc, Init->getBeginLoc(), Init->getEndLoc())
: InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
InitRange.getEnd());
InitializationSequence InitSeq(*this, MemberEntity, Kind, Args);
ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args,
nullptr);
if (!MemberInit.isInvalid()) {
// C++11 [class.base.init]p7:
// The initialization of each base and member constitutes a
// full-expression.
MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin(),
/*DiscardedValue*/ false);
}
if (MemberInit.isInvalid()) {
// Args were sensible expressions but we couldn't initialize the member
// from them. Preserve them in a RecoveryExpr instead.
Init = CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(), Args,
Member->getType())
.get();
if (!Init)
return true;
} else {
Init = MemberInit.get();
}
}
if (DirectMember) {
return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
InitRange.getBegin(), Init,
InitRange.getEnd());
} else {
return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
InitRange.getBegin(), Init,
InitRange.getEnd());
}
}
MemInitResult
Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
CXXRecordDecl *ClassDecl) {
SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
if (!LangOpts.CPlusPlus11)
return Diag(NameLoc, diag::err_delegating_ctor)
<< TInfo->getTypeLoc().getLocalSourceRange();
Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
bool InitList = true;
MultiExprArg Args = Init;
if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
InitList = false;
Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
}
SourceRange InitRange = Init->getSourceRange();
// Initialize the object.
InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
QualType(ClassDecl->getTypeForDecl(), 0));
InitializationKind Kind =
InitList ? InitializationKind::CreateDirectList(
NameLoc, Init->getBeginLoc(), Init->getEndLoc())
: InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
InitRange.getEnd());
InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args);
ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
Args, nullptr);
if (!DelegationInit.isInvalid()) {
assert((DelegationInit.get()->containsErrors() ||
cast<CXXConstructExpr>(DelegationInit.get())->getConstructor()) &&
"Delegating constructor with no target?");
// C++11 [class.base.init]p7:
// The initialization of each base and member constitutes a
// full-expression.
DelegationInit = ActOnFinishFullExpr(
DelegationInit.get(), InitRange.getBegin(), /*DiscardedValue*/ false);
}
if (DelegationInit.isInvalid()) {
DelegationInit =
CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(), Args,
QualType(ClassDecl->getTypeForDecl(), 0));
if (DelegationInit.isInvalid())
return true;
} else {
// If we are in a dependent context, template instantiation will
// perform this type-checking again. Just save the arguments that we
// received in a ParenListExpr.
// FIXME: This isn't quite ideal, since our ASTs don't capture all
// of the information that we have about the base
// initializer. However, deconstructing the ASTs is a dicey process,
// and this approach is far more likely to get the corner cases right.
if (CurContext->isDependentContext())
DelegationInit = Init;
}
return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
DelegationInit.getAs<Expr>(),
InitRange.getEnd());
}
MemInitResult
Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
Expr *Init, CXXRecordDecl *ClassDecl,
SourceLocation EllipsisLoc) {
SourceLocation BaseLoc
= BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();
if (!BaseType->isDependentType() && !BaseType->isRecordType())
return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
<< BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
// C++ [class.base.init]p2:
// [...] Unless the mem-initializer-id names a nonstatic data
// member of the constructor's class or a direct or virtual base
// of that class, the mem-initializer is ill-formed. A
// mem-initializer-list can initialize a base class using any
// name that denotes that base class type.
// We can store the initializers in "as-written" form and delay analysis until
// instantiation if the constructor is dependent. But not for dependent
// (broken) code in a non-template! SetCtorInitializers does not expect this.
bool Dependent = CurContext->isDependentContext() &&
(BaseType->isDependentType() || Init->isTypeDependent());
SourceRange InitRange = Init->getSourceRange();
if (EllipsisLoc.isValid()) {
// This is a pack expansion.
if (!BaseType->containsUnexpandedParameterPack()) {
Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
<< SourceRange(BaseLoc, InitRange.getEnd());
EllipsisLoc = SourceLocation();
}
} else {
// Check for any unexpanded parameter packs.
if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
return true;
if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
return true;
}
// Check for direct and virtual base classes.
const CXXBaseSpecifier *DirectBaseSpec = nullptr;
const CXXBaseSpecifier *VirtualBaseSpec = nullptr;
if (!Dependent) {
if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
BaseType))
return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
VirtualBaseSpec);
// C++ [base.class.init]p2:
// Unless the mem-initializer-id names a nonstatic data member of the
// constructor's class or a direct or virtual base of that class, the
// mem-initializer is ill-formed.
if (!DirectBaseSpec && !VirtualBaseSpec) {
// If the class has any dependent bases, then it's possible that
// one of those types will resolve to the same type as
// BaseType. Therefore, just treat this as a dependent base
// class initialization. FIXME: Should we try to check the
// initialization anyway? It seems odd.
if (ClassDecl->hasAnyDependentBases())
Dependent = true;
else
return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
<< BaseType << Context.getTypeDeclType(ClassDecl)
<< BaseTInfo->getTypeLoc().getLocalSourceRange();
}
}
if (Dependent) {
DiscardCleanupsInEvaluationContext();
return new (Context) CXXCtorInitializer(Context, BaseTInfo,
/*IsVirtual=*/false,
InitRange.getBegin(), Init,
InitRange.getEnd(), EllipsisLoc);
}
// C++ [base.class.init]p2:
// If a mem-initializer-id is ambiguous because it designates both
// a direct non-virtual base class and an inherited virtual base
// class, the mem-initializer is ill-formed.
if (DirectBaseSpec && VirtualBaseSpec)
return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
<< BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
const CXXBaseSpecifier *BaseSpec = DirectBaseSpec;
if (!BaseSpec)
BaseSpec = VirtualBaseSpec;
// Initialize the base.
bool InitList = true;
MultiExprArg Args = Init;
if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
InitList = false;
Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
}
InitializedEntity BaseEntity =
InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
InitializationKind Kind =
InitList ? InitializationKind::CreateDirectList(BaseLoc)
: InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
InitRange.getEnd());
InitializationSequence InitSeq(*this, BaseEntity, Kind, Args);
ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr);
if (!BaseInit.isInvalid()) {
// C++11 [class.base.init]p7:
// The initialization of each base and member constitutes a
// full-expression.
BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin(),
/*DiscardedValue*/ false);
}
if (BaseInit.isInvalid()) {
BaseInit = CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(),
Args, BaseType);
if (BaseInit.isInvalid())
return true;
} else {
// If we are in a dependent context, template instantiation will
// perform this type-checking again. Just save the arguments that we
// received in a ParenListExpr.
// FIXME: This isn't quite ideal, since our ASTs don't capture all
// of the information that we have about the base
// initializer. However, deconstructing the ASTs is a dicey process,
// and this approach is far more likely to get the corner cases right.
if (CurContext->isDependentContext())
BaseInit = Init;
}
return new (Context) CXXCtorInitializer(Context, BaseTInfo,
BaseSpec->isVirtual(),
InitRange.getBegin(),
BaseInit.getAs<Expr>(),
InitRange.getEnd(), EllipsisLoc);
}
// Create a static_cast\<T&&>(expr).
static Expr *CastForMoving(Sema &SemaRef, Expr *E, QualType T = QualType()) {
if (T.isNull()) T = E->getType();
QualType TargetType = SemaRef.BuildReferenceType(
T, /*SpelledAsLValue*/false, SourceLocation(), DeclarationName());
SourceLocation ExprLoc = E->getBeginLoc();
TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
TargetType, ExprLoc);
return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
SourceRange(ExprLoc, ExprLoc),
E->getSourceRange()).get();
}
/// ImplicitInitializerKind - How an implicit base or member initializer should
/// initialize its base or member.
enum ImplicitInitializerKind {
IIK_Default,
IIK_Copy,
IIK_Move,
IIK_Inherit
};
static bool
BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
ImplicitInitializerKind ImplicitInitKind,
CXXBaseSpecifier *BaseSpec,
bool IsInheritedVirtualBase,
CXXCtorInitializer *&CXXBaseInit) {
InitializedEntity InitEntity
= InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
IsInheritedVirtualBase);
ExprResult BaseInit;
switch (ImplicitInitKind) {
case IIK_Inherit:
case IIK_Default: {
InitializationKind InitKind
= InitializationKind::CreateDefault(Constructor->getLocation());
InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
break;
}
case IIK_Move:
case IIK_Copy: {
bool Moving = ImplicitInitKind == IIK_Move;
ParmVarDecl *Param = Constructor->getParamDecl(0);
QualType ParamType = Param->getType().getNonReferenceType();
Expr *CopyCtorArg =
DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
SourceLocation(), Param, false,
Constructor->getLocation(), ParamType,
VK_LValue, nullptr);
SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
// Cast to the base class to avoid ambiguities.
QualType ArgTy =
SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
ParamType.getQualifiers());
if (Moving) {
CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
}
CXXCastPath BasePath;
BasePath.push_back(BaseSpec);
CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
CK_UncheckedDerivedToBase,
Moving ? VK_XValue : VK_LValue,
&BasePath).get();
InitializationKind InitKind
= InitializationKind::CreateDirect(Constructor->getLocation(),
SourceLocation(), SourceLocation());
InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg);
BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg);
break;
}
}
BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
if (BaseInit.isInvalid())
return true;
CXXBaseInit =
new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
SourceLocation()),
BaseSpec->isVirtual(),
SourceLocation(),
BaseInit.getAs<Expr>(),
SourceLocation(),
SourceLocation());
return false;
}
static bool RefersToRValueRef(Expr *MemRef) {
ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
return Referenced->getType()->isRValueReferenceType();
}
static bool
BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
ImplicitInitializerKind ImplicitInitKind,
FieldDecl *Field, IndirectFieldDecl *Indirect,
CXXCtorInitializer *&CXXMemberInit) {
if (Field->isInvalidDecl())
return true;
SourceLocation Loc = Constructor->getLocation();
if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
bool Moving = ImplicitInitKind == IIK_Move;
ParmVarDecl *Param = Constructor->getParamDecl(0);
QualType ParamType = Param->getType().getNonReferenceType();
// Suppress copying zero-width bitfields.
if (Field->isZeroLengthBitField(SemaRef.Context))
return false;
Expr *MemberExprBase =
DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
SourceLocation(), Param, false,
Loc, ParamType, VK_LValue, nullptr);
SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));
if (Moving) {
MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
}
// Build a reference to this field within the parameter.
CXXScopeSpec SS;
LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
Sema::LookupMemberName);
MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
: cast<ValueDecl>(Field), AS_public);
MemberLookup.resolveKind();
ExprResult CtorArg
= SemaRef.BuildMemberReferenceExpr(MemberExprBase,
ParamType, Loc,
/*IsArrow=*/false,
SS,
/*TemplateKWLoc=*/SourceLocation(),
/*FirstQualifierInScope=*/nullptr,
MemberLookup,
/*TemplateArgs=*/nullptr,
/*S*/nullptr);
if (CtorArg.isInvalid())
return true;
// C++11 [class.copy]p15:
// - if a member m has rvalue reference type T&&, it is direct-initialized
// with static_cast<T&&>(x.m);
if (RefersToRValueRef(CtorArg.get())) {
CtorArg = CastForMoving(SemaRef, CtorArg.get());
}
InitializedEntity Entity =
Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
/*Implicit*/ true)
: InitializedEntity::InitializeMember(Field, nullptr,
/*Implicit*/ true);
// Direct-initialize to use the copy constructor.
InitializationKind InitKind =
InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation());
Expr *CtorArgE = CtorArg.getAs<Expr>();
InitializationSequence InitSeq(SemaRef, Entity, InitKind, CtorArgE);
ExprResult MemberInit =
InitSeq.Perform(SemaRef, Entity, InitKind, MultiExprArg(&CtorArgE, 1));
MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
if (MemberInit.isInvalid())
return true;
if (Indirect)
CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
else
CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
SemaRef.Context, Field, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
return false;
}
assert((ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) &&
"Unhandled implicit init kind!");
QualType FieldBaseElementType =
SemaRef.Context.getBaseElementType(Field->getType());
if (FieldBaseElementType->isRecordType()) {
InitializedEntity InitEntity =
Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
/*Implicit*/ true)
: InitializedEntity::InitializeMember(Field, nullptr,
/*Implicit*/ true);
InitializationKind InitKind =
InitializationKind::CreateDefault(Loc);
InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
ExprResult MemberInit =
InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
if (MemberInit.isInvalid())
return true;
if (Indirect)
CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
Indirect, Loc,
Loc,
MemberInit.get(),
Loc);
else
CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
Field, Loc, Loc,
MemberInit.get(),
Loc);
return false;
}
if (!Field->getParent()->isUnion()) {
if (FieldBaseElementType->isReferenceType()) {
SemaRef.Diag(Constructor->getLocation(),
diag::err_uninitialized_member_in_ctor)
<< (int)Constructor->isImplicit()
<< SemaRef.Context.getTagDeclType(Constructor->getParent())
<< 0 << Field->getDeclName();
SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
return true;
}
if (FieldBaseElementType.isConstQualified()) {
SemaRef.Diag(Constructor->getLocation(),
diag::err_uninitialized_member_in_ctor)
<< (int)Constructor->isImplicit()
<< SemaRef.Context.getTagDeclType(Constructor->getParent())
<< 1 << Field->getDeclName();
SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
return true;
}
}
if (FieldBaseElementType.hasNonTrivialObjCLifetime()) {
// ARC and Weak:
// Default-initialize Objective-C pointers to NULL.
CXXMemberInit
= new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
Loc, Loc,
new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
Loc);
return false;
}
// Nothing to initialize.
CXXMemberInit = nullptr;
return false;
}
namespace {
struct BaseAndFieldInfo {
Sema &S;
CXXConstructorDecl *Ctor;
bool AnyErrorsInInits;
ImplicitInitializerKind IIK;
llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
SmallVector<CXXCtorInitializer*, 8> AllToInit;
llvm::DenseMap<TagDecl*, FieldDecl*> ActiveUnionMember;
BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
: S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
if (Ctor->getInheritedConstructor())
IIK = IIK_Inherit;
else if (Generated && Ctor->isCopyConstructor())
IIK = IIK_Copy;
else if (Generated && Ctor->isMoveConstructor())
IIK = IIK_Move;
else
IIK = IIK_Default;
}
bool isImplicitCopyOrMove() const {
switch (IIK) {
case IIK_Copy:
case IIK_Move:
return true;
case IIK_Default:
case IIK_Inherit:
return false;
}
llvm_unreachable("Invalid ImplicitInitializerKind!");
}
bool addFieldInitializer(CXXCtorInitializer *Init) {
AllToInit.push_back(Init);
// Check whether this initializer makes the field "used".
if (Init->getInit()->HasSideEffects(S.Context))
S.UnusedPrivateFields.remove(Init->getAnyMember());
return false;
}
bool isInactiveUnionMember(FieldDecl *Field) {
RecordDecl *Record = Field->getParent();
if (!Record->isUnion())
return false;
if (FieldDecl *Active =
ActiveUnionMember.lookup(Record->getCanonicalDecl()))
return Active != Field->getCanonicalDecl();
// In an implicit copy or move constructor, ignore any in-class initializer.
if (isImplicitCopyOrMove())
return true;
// If there's no explicit initialization, the field is active only if it
// has an in-class initializer...
if (Field->hasInClassInitializer())
return false;
// ... or it's an anonymous struct or union whose class has an in-class
// initializer.
if (!Field->isAnonymousStructOrUnion())
return true;
CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl();
return !FieldRD->hasInClassInitializer();
}
/// Determine whether the given field is, or is within, a union member
/// that is inactive (because there was an initializer given for a different
/// member of the union, or because the union was not initialized at all).
bool isWithinInactiveUnionMember(FieldDecl *Field,
IndirectFieldDecl *Indirect) {
if (!Indirect)
return isInactiveUnionMember(Field);
for (auto *C : Indirect->chain()) {
FieldDecl *Field = dyn_cast<FieldDecl>(C);
if (Field && isInactiveUnionMember(Field))
return true;
}
return false;
}
};
}
/// Determine whether the given type is an incomplete or zero-lenfgth
/// array type.
static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) {
if (T->isIncompleteArrayType())
return true;
while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
if (!ArrayT->getSize())
return true;
T = ArrayT->getElementType();
}
return false;
}
static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
FieldDecl *Field,
IndirectFieldDecl *Indirect = nullptr) {
if (Field->isInvalidDecl())
return false;
// Overwhelmingly common case: we have a direct initializer for this field.
if (CXXCtorInitializer *Init =
Info.AllBaseFields.lookup(Field->getCanonicalDecl()))
return Info.addFieldInitializer(Init);
// C++11 [class.base.init]p8:
// if the entity is a non-static data member that has a
// brace-or-equal-initializer and either
// -- the constructor's class is a union and no other variant member of that
// union is designated by a mem-initializer-id or
// -- the constructor's class is not a union, and, if the entity is a member
// of an anonymous union, no other member of that union is designated by
// a mem-initializer-id,
// the entity is initialized as specified in [dcl.init].
//
// We also apply the same rules to handle anonymous structs within anonymous
// unions.
if (Info.isWithinInactiveUnionMember(Field, Indirect))
return false;
if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
ExprResult DIE =
SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field);
if (DIE.isInvalid())
return true;
auto Entity = InitializedEntity::InitializeMember(Field, nullptr, true);
SemaRef.checkInitializerLifetime(Entity, DIE.get());
CXXCtorInitializer *Init;
if (Indirect)
Init = new (SemaRef.Context)
CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(),
SourceLocation(), DIE.get(), SourceLocation());
else
Init = new (SemaRef.Context)
CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(),
SourceLocation(), DIE.get(), SourceLocation());
return Info.addFieldInitializer(Init);
}
// Don't initialize incomplete or zero-length arrays.
if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
return false;
// Don't try to build an implicit initializer if there were semantic
// errors in any of the initializers (and therefore we might be
// missing some that the user actually wrote).
if (Info.AnyErrorsInInits)
return false;
CXXCtorInitializer *Init = nullptr;
if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
Indirect, Init))
return true;
if (!Init)
return false;
return Info.addFieldInitializer(Init);
}
bool
Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor,
CXXCtorInitializer *Initializer) {
assert(Initializer->isDelegatingInitializer());
Constructor->setNumCtorInitializers(1);
CXXCtorInitializer **initializer =
new (Context) CXXCtorInitializer*[1];
memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
Constructor->setCtorInitializers(initializer);
if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
}
DelegatingCtorDecls.push_back(Constructor);
DiagnoseUninitializedFields(*this, Constructor);
return false;
}
bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
ArrayRef<CXXCtorInitializer *> Initializers) {
if (Constructor->isDependentContext()) {
// Just store the initializers as written, they will be checked during
// instantiation.
if (!Initializers.empty()) {
Constructor->setNumCtorInitializers(Initializers.size());
CXXCtorInitializer **baseOrMemberInitializers =
new (Context) CXXCtorInitializer*[Initializers.size()];
memcpy(baseOrMemberInitializers, Initializers.data(),
Initializers.size() * sizeof(CXXCtorInitializer*));
Constructor->setCtorInitializers(baseOrMemberInitializers);
}
// Let template instantiation know whether we had errors.
if (AnyErrors)
Constructor->setInvalidDecl();
return false;
}
BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
// We need to build the initializer AST according to order of construction
// and not what user specified in the Initializers list.
CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
if (!ClassDecl)
return true;
bool HadError = false;
for (unsigned i = 0; i < Initializers.size(); i++) {
CXXCtorInitializer *Member = Initializers[i];
if (Member->isBaseInitializer())
Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
else {
Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member;
if (IndirectFieldDecl *F = Member->getIndirectMember()) {
for (auto *C : F->chain()) {
FieldDecl *FD = dyn_cast<FieldDecl>(C);
if (FD && FD->getParent()->isUnion())
Info.ActiveUnionMember.insert(std::make_pair(
FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
}
} else if (FieldDecl *FD = Member->getMember()) {
if (FD->getParent()->isUnion())
Info.ActiveUnionMember.insert(std::make_pair(
FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
}
}
}
// Keep track of the direct virtual bases.
llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
for (auto &I : ClassDecl->bases()) {
if (I.isVirtual())
DirectVBases.insert(&I);
}
// Push virtual bases before others.
for (auto &VBase : ClassDecl->vbases()) {
if (CXXCtorInitializer *Value
= Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) {
// [class.base.init]p7, per DR257:
// A mem-initializer where the mem-initializer-id names a virtual base
// class is ignored during execution of a constructor of any class that
// is not the most derived class.
if (ClassDecl->isAbstract()) {
// FIXME: Provide a fixit to remove the base specifier. This requires
// tracking the location of the associated comma for a base specifier.
Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored)
<< VBase.getType() << ClassDecl;
DiagnoseAbstractType(ClassDecl);
}
Info.AllToInit.push_back(Value);
} else if (!AnyErrors && !ClassDecl->isAbstract()) {
// [class.base.init]p8, per DR257:
// If a given [...] base class is not named by a mem-initializer-id
// [...] and the entity is not a virtual base class of an abstract
// class, then [...] the entity is default-initialized.
bool IsInheritedVirtualBase = !DirectVBases.count(&VBase);
CXXCtorInitializer *CXXBaseInit;
if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
&VBase, IsInheritedVirtualBase,
CXXBaseInit)) {
HadError = true;
continue;
}
Info.AllToInit.push_back(CXXBaseInit);
}
}
// Non-virtual bases.
for (auto &Base : ClassDecl->bases()) {
// Virtuals are in the virtual base list and already constructed.
if (Base.isVirtual())
continue;
if (CXXCtorInitializer *Value
= Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) {
Info.AllToInit.push_back(Value);
} else if (!AnyErrors) {
CXXCtorInitializer *CXXBaseInit;
if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
&Base, /*IsInheritedVirtualBase=*/false,
CXXBaseInit)) {
HadError = true;
continue;
}
Info.AllToInit.push_back(CXXBaseInit);
}
}
// Fields.
for (auto *Mem : ClassDecl->decls()) {
if (auto *F = dyn_cast<FieldDecl>(Mem)) {
// C++ [class.bit]p2:
// A declaration for a bit-field that omits the identifier declares an
// unnamed bit-field. Unnamed bit-fields are not members and cannot be
// initialized.
if (F->isUnnamedBitfield())
continue;
// If we're not generating the implicit copy/move constructor, then we'll
// handle anonymous struct/union fields based on their individual
// indirect fields.
if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove())
continue;
if (CollectFieldInitializer(*this, Info, F))
HadError = true;
continue;
}
// Beyond this point, we only consider default initialization.
if (Info.isImplicitCopyOrMove())
continue;
if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) {
if (F->getType()->isIncompleteArrayType()) {
assert(ClassDecl->hasFlexibleArrayMember() &&
"Incomplete array type is not valid");
continue;
}
// Initialize each field of an anonymous struct individually.
if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
HadError = true;
continue;
}
}
unsigned NumInitializers = Info.AllToInit.size();
if (NumInitializers > 0) {
Constructor->setNumCtorInitializers(NumInitializers);
CXXCtorInitializer **baseOrMemberInitializers =
new (Context) CXXCtorInitializer*[NumInitializers];
memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
NumInitializers * sizeof(CXXCtorInitializer*));
Constructor->setCtorInitializers(baseOrMemberInitializers);
// Constructors implicitly reference the base and member
// destructors.
MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
Constructor->getParent());
}
return HadError;
}
static void PopulateKeysForFields(FieldDecl *Field, SmallVectorImpl<const void*> &IdealInits) {
if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
const RecordDecl *RD = RT->getDecl();
if (RD->isAnonymousStructOrUnion()) {
for (auto *Field : RD->fields())
PopulateKeysForFields(Field, IdealInits);
return;
}
}
IdealInits.push_back(Field->getCanonicalDecl());
}
static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
return Context.getCanonicalType(BaseType).getTypePtr();
}
static const void *GetKeyForMember(ASTContext &Context,
CXXCtorInitializer *Member) {
if (!Member->isAnyMemberInitializer())
return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
return Member->getAnyMember()->getCanonicalDecl();
}
static void AddInitializerToDiag(const Sema::SemaDiagnosticBuilder &Diag,
const CXXCtorInitializer *Previous,
const CXXCtorInitializer *Current) {
if (Previous->isAnyMemberInitializer())
Diag << 0 << Previous->getAnyMember();
else
Diag << 1 << Previous->getTypeSourceInfo()->getType();
if (Current->isAnyMemberInitializer())
Diag << 0 << Current->getAnyMember();
else
Diag << 1 << Current->getTypeSourceInfo()->getType();
}
static void DiagnoseBaseOrMemInitializerOrder(
Sema &SemaRef, const CXXConstructorDecl *Constructor,
ArrayRef<CXXCtorInitializer *> Inits) {
if (Constructor->getDeclContext()->isDependentContext())
return;
// Don't check initializers order unless the warning is enabled at the
// location of at least one initializer.
bool ShouldCheckOrder = false;
for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
CXXCtorInitializer *Init = Inits[InitIndex];
if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order,
Init->getSourceLocation())) {
ShouldCheckOrder = true;
break;
}
}
if (!ShouldCheckOrder)
return;
// Build the list of bases and members in the order that they'll
// actually be initialized. The explicit initializers should be in
// this same order but may be missing things.
SmallVector<const void*, 32> IdealInitKeys;
const CXXRecordDecl *ClassDecl = Constructor->getParent();
// 1. Virtual bases.
for (const auto &VBase : ClassDecl->vbases())
IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType()));
// 2. Non-virtual bases.
for (const auto &Base : ClassDecl->bases()) {
if (Base.isVirtual())
continue;
IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType()));
}
// 3. Direct fields.
for (auto *Field : ClassDecl->fields()) {
if (Field->isUnnamedBitfield())
continue;
PopulateKeysForFields(Field, IdealInitKeys);
}
unsigned NumIdealInits = IdealInitKeys.size();
unsigned IdealIndex = 0;
// Track initializers that are in an incorrect order for either a warning or
// note if multiple ones occur.
SmallVector<unsigned> WarnIndexes;
// Correlates the index of an initializer in the init-list to the index of
// the field/base in the class.
SmallVector<std::pair<unsigned, unsigned>, 32> CorrelatedInitOrder;
for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
const void *InitKey = GetKeyForMember(SemaRef.Context, Inits[InitIndex]);
// Scan forward to try to find this initializer in the idealized
// initializers list.
for (; IdealIndex != NumIdealInits; ++IdealIndex)
if (InitKey == IdealInitKeys[IdealIndex])
break;
// If we didn't find this initializer, it must be because we
// scanned past it on a previous iteration. That can only
// happen if we're out of order; emit a warning.
if (IdealIndex == NumIdealInits && InitIndex) {
WarnIndexes.push_back(InitIndex);
// Move back to the initializer's location in the ideal list.
for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
if (InitKey == IdealInitKeys[IdealIndex])
break;
assert(IdealIndex < NumIdealInits &&
"initializer not found in initializer list");
}
CorrelatedInitOrder.emplace_back(IdealIndex, InitIndex);
}
if (WarnIndexes.empty())
return;
// Sort based on the ideal order, first in the pair.
llvm::sort(CorrelatedInitOrder,
[](auto &LHS, auto &RHS) { return LHS.first < RHS.first; });
// Introduce a new scope as SemaDiagnosticBuilder needs to be destroyed to
// emit the diagnostic before we can try adding notes.
{
Sema::SemaDiagnosticBuilder D = SemaRef.Diag(
Inits[WarnIndexes.front() - 1]->getSourceLocation(),
WarnIndexes.size() == 1 ? diag::warn_initializer_out_of_order
: diag::warn_some_initializers_out_of_order);
for (unsigned I = 0; I < CorrelatedInitOrder.size(); ++I) {
if (CorrelatedInitOrder[I].second == I)
continue;
// Ideally we would be using InsertFromRange here, but clang doesn't
// appear to handle InsertFromRange correctly when the source range is
// modified by another fix-it.
D << FixItHint::CreateReplacement(
Inits[I]->getSourceRange(),
Lexer::getSourceText(
CharSourceRange::getTokenRange(
Inits[CorrelatedInitOrder[I].second]->getSourceRange()),
SemaRef.getSourceManager(), SemaRef.getLangOpts()));
}
// If there is only 1 item out of order, the warning expects the name and
// type of each being added to it.
if (WarnIndexes.size() == 1) {
AddInitializerToDiag(D, Inits[WarnIndexes.front() - 1],
Inits[WarnIndexes.front()]);
return;
}
}
// More than 1 item to warn, create notes letting the user know which ones
// are bad.
for (unsigned WarnIndex : WarnIndexes) {
const clang::CXXCtorInitializer *PrevInit = Inits[WarnIndex - 1];
auto D = SemaRef.Diag(PrevInit->getSourceLocation(),
diag::note_initializer_out_of_order);
AddInitializerToDiag(D, PrevInit, Inits[WarnIndex]);
D << PrevInit->getSourceRange();
}
}
namespace {
bool CheckRedundantInit(Sema &S,
CXXCtorInitializer *Init,
CXXCtorInitializer *&PrevInit) {
if (!PrevInit) {
PrevInit = Init;
return false;
}
if (FieldDecl *Field = Init->getAnyMember())
S.Diag(Init->getSourceLocation(),
diag::err_multiple_mem_initialization)
<< Field->getDeclName()
<< Init->getSourceRange();
else {
const Type *BaseClass = Init->getBaseClass();
assert(BaseClass && "neither field nor base");
S.Diag(Init->getSourceLocation(),
diag::err_multiple_base_initialization)
<< QualType(BaseClass, 0)
<< Init->getSourceRange();
}
S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
<< 0 << PrevInit->getSourceRange();
return true;
}
typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
bool CheckRedundantUnionInit(Sema &S,
CXXCtorInitializer *Init,
RedundantUnionMap &Unions) {
FieldDecl *Field = Init->getAnyMember();
RecordDecl *Parent = Field->getParent();
NamedDecl *Child = Field;
while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
if (Parent->isUnion()) {
UnionEntry &En = Unions[Parent];
if (En.first && En.first != Child) {
S.Diag(Init->getSourceLocation(),
diag::err_multiple_mem_union_initialization)
<< Field->getDeclName()
<< Init->getSourceRange();
S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
<< 0 << En.second->getSourceRange();
return true;
}
if (!En.first) {
En.first = Child;
En.second = Init;
}
if (!Parent->isAnonymousStructOrUnion())
return false;
}
Child = Parent;
Parent = cast<RecordDecl>(Parent->getDeclContext());
}
return false;
}
} // namespace
/// ActOnMemInitializers - Handle the member initializers for a constructor.
void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
SourceLocation ColonLoc,
ArrayRef<CXXCtorInitializer*> MemInits,
bool AnyErrors) {
if (!ConstructorDecl)
return;
AdjustDeclIfTemplate(ConstructorDecl);
CXXConstructorDecl *Constructor
= dyn_cast<CXXConstructorDecl>(ConstructorDecl);
if (!Constructor) {
Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
return;
}
// Mapping for the duplicate initializers check.
// For member initializers, this is keyed with a FieldDecl*.
// For base initializers, this is keyed with a Type*.
llvm::DenseMap<const void *, CXXCtorInitializer *> Members;
// Mapping for the inconsistent anonymous-union initializers check.
RedundantUnionMap MemberUnions;
bool HadError = false;
for (unsigned i = 0; i < MemInits.size(); i++) {
CXXCtorInitializer *Init = MemInits[i];
// Set the source order index.
Init->setSourceOrder(i);
if (Init->isAnyMemberInitializer()) {
const void *Key = GetKeyForMember(Context, Init);
if (CheckRedundantInit(*this, Init, Members[Key]) ||
CheckRedundantUnionInit(*this, Init, MemberUnions))
HadError = true;
} else if (Init->isBaseInitializer()) {
const void *Key = GetKeyForMember(Context, Init);
if (CheckRedundantInit(*this, Init, Members[Key]))
HadError = true;
} else {
assert(Init->isDelegatingInitializer());
// This must be the only initializer
if (MemInits.size() != 1) {
Diag(Init->getSourceLocation(),
diag::err_delegating_initializer_alone)
<< Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange();
// We will treat this as being the only initializer.
}
SetDelegatingInitializer(Constructor, MemInits[i]);
// Return immediately as the initializer is set.
return;
}
}
if (HadError)
return;
DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits);
SetCtorInitializers(Constructor, AnyErrors, MemInits);
DiagnoseUninitializedFields(*this, Constructor);
}
void
Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,
CXXRecordDecl *ClassDecl) {
// Ignore dependent contexts. Also ignore unions, since their members never
// have destructors implicitly called.
if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
return;
// FIXME: all the access-control diagnostics are positioned on the
// field/base declaration. That's probably good; that said, the
// user might reasonably want to know why the destructor is being
// emitted, and we currently don't say.
// Non-static data members.
for (auto *Field : ClassDecl->fields()) {
if (Field->isInvalidDecl())
continue;
// Don't destroy incomplete or zero-length arrays.
if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
continue;
QualType FieldType = Context.getBaseElementType(Field->getType());
const RecordType* RT = FieldType->getAs<RecordType>();
if (!RT)
continue;
CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
if (FieldClassDecl->isInvalidDecl())
continue;
if (FieldClassDecl->hasIrrelevantDestructor())
continue;
// The destructor for an implicit anonymous union member is never invoked.
if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
continue;
CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
assert(Dtor && "No dtor found for FieldClassDecl!");
CheckDestructorAccess(Field->getLocation(), Dtor,
PDiag(diag::err_access_dtor_field)
<< Field->getDeclName()
<< FieldType);
MarkFunctionReferenced(Location, Dtor);
DiagnoseUseOfDecl(Dtor, Location);
}
// We only potentially invoke the destructors of potentially constructed
// subobjects.
bool VisitVirtualBases = !ClassDecl->isAbstract();
// If the destructor exists and has already been marked used in the MS ABI,
// then virtual base destructors have already been checked and marked used.
// Skip checking them again to avoid duplicate diagnostics.
if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
CXXDestructorDecl *Dtor = ClassDecl->getDestructor();
if (Dtor && Dtor->isUsed())
VisitVirtualBases = false;
}
llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
// Bases.
for (const auto &Base : ClassDecl->bases()) {
const RecordType *RT = Base.getType()->getAs<RecordType>();
if (!RT)
continue;
// Remember direct virtual bases.
if (Base.isVirtual()) {
if (!VisitVirtualBases)
continue;
DirectVirtualBases.insert(RT);
}
CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
// If our base class is invalid, we probably can't get its dtor anyway.
if (BaseClassDecl->isInvalidDecl())
continue;
if (BaseClassDecl->hasIrrelevantDestructor())
continue;
CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
assert(Dtor && "No dtor found for BaseClassDecl!");
// FIXME: caret should be on the start of the class name
CheckDestructorAccess(Base.getBeginLoc(), Dtor,
PDiag(diag::err_access_dtor_base)
<< Base.getType() << Base.getSourceRange(),
Context.getTypeDeclType(ClassDecl));
MarkFunctionReferenced(Location, Dtor);
DiagnoseUseOfDecl(Dtor, Location);
}
if (VisitVirtualBases)
MarkVirtualBaseDestructorsReferenced(Location, ClassDecl,
&DirectVirtualBases);
}
void Sema::MarkVirtualBaseDestructorsReferenced(
SourceLocation Location, CXXRecordDecl *ClassDecl,
llvm::SmallPtrSetImpl<const RecordType *> *DirectVirtualBases) {
// Virtual bases.
for (const auto &VBase : ClassDecl->vbases()) {
// Bases are always records in a well-formed non-dependent class.
const RecordType *RT = VBase.getType()->castAs<RecordType>();
// Ignore already visited direct virtual bases.
if (DirectVirtualBases && DirectVirtualBases->count(RT))
continue;
CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
// If our base class is invalid, we probably can't get its dtor anyway.
if (BaseClassDecl->isInvalidDecl())
continue;
if (BaseClassDecl->hasIrrelevantDestructor())
continue;
CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
assert(Dtor && "No dtor found for BaseClassDecl!");
if (CheckDestructorAccess(
ClassDecl->getLocation(), Dtor,
PDiag(diag::err_access_dtor_vbase)
<< Context.getTypeDeclType(ClassDecl) << VBase.getType(),
Context.getTypeDeclType(ClassDecl)) ==
AR_accessible) {
CheckDerivedToBaseConversion(
Context.getTypeDeclType(ClassDecl), VBase.getType(),
diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(),
SourceRange(), DeclarationName(), nullptr);
}
MarkFunctionReferenced(Location, Dtor);
DiagnoseUseOfDecl(Dtor, Location);
}
}
void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
if (!CDtorDecl)
return;
if (CXXConstructorDecl *Constructor
= dyn_cast<CXXConstructorDecl>(CDtorDecl)) {
SetCtorInitializers(Constructor, /*AnyErrors=*/false);
DiagnoseUninitializedFields(*this, Constructor);
}
}
bool Sema::isAbstractType(SourceLocation Loc, QualType T) {
if (!getLangOpts().CPlusPlus)
return false;
const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl();
if (!RD)
return false;
// FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a
// class template specialization here, but doing so breaks a lot of code.
// We can't answer whether something is abstract until it has a
// definition. If it's currently being defined, we'll walk back
// over all the declarations when we have a full definition.
const CXXRecordDecl *Def = RD->getDefinition();
if (!Def || Def->isBeingDefined())
return false;
return RD->isAbstract();
}
bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
TypeDiagnoser &Diagnoser) {
if (!isAbstractType(Loc, T))
return false;
T = Context.getBaseElementType(T);
Diagnoser.diagnose(*this, Loc, T);
DiagnoseAbstractType(T->getAsCXXRecordDecl());
return true;
}
void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) {
// Check if we've already emitted the list of pure virtual functions
// for this class.
if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
return;
// If the diagnostic is suppressed, don't emit the notes. We're only
// going to emit them once, so try to attach them to a diagnostic we're
// actually going to show.
if (Diags.isLastDiagnosticIgnored())
return;
CXXFinalOverriderMap FinalOverriders;
RD->getFinalOverriders(FinalOverriders);
// Keep a set of seen pure methods so we won't diagnose the same method
// more than once.
llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
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) {
// C++ [class.abstract]p4:
// A class is abstract if it contains or inherits at least one
// pure virtual function for which the final overrider is pure
// virtual.
//
if (SO->second.size() != 1)
continue;
if (!SO->second.front().Method->isPure())
continue;
if (!SeenPureMethods.insert(SO->second.front().Method).second)
continue;
Diag(SO->second.front().Method->getLocation(),
diag::note_pure_virtual_function)
<< SO->second.front().Method->getDeclName() << RD->getDeclName();
}
}
if (!PureVirtualClassDiagSet)
PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
PureVirtualClassDiagSet->insert(RD);
}
namespace {
struct AbstractUsageInfo {
Sema &S;
CXXRecordDecl *Record;
CanQualType AbstractType;
bool Invalid;
AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
: S(S), Record(Record),
AbstractType(S.Context.getCanonicalType(
S.Context.getTypeDeclType(Record))),
Invalid(false) {}
void DiagnoseAbstractType() {
if (Invalid) return;
S.DiagnoseAbstractType(Record);
Invalid = true;
}
void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
};
struct CheckAbstractUsage {
AbstractUsageInfo &Info;
const NamedDecl *Ctx;
CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
: Info(Info), Ctx(Ctx) {}
void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
switch (TL.getTypeLocClass()) {
#define ABSTRACT_TYPELOC(CLASS, PARENT)
#define TYPELOC(CLASS, PARENT) \
case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break;
#include "clang/AST/TypeLocNodes.def"
}
}
void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
Visit(TL.getReturnLoc(), Sema::AbstractReturnType);
for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) {
if (!TL.getParam(I))
continue;
TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo();
if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
}
}
void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
Visit(TL.getElementLoc(), Sema::AbstractArrayType);
}
void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) {
// Visit the type parameters from a permissive context.
for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
TemplateArgumentLoc TAL = TL.getArgLoc(I);
if (TAL.getArgument().getKind() == TemplateArgument::Type)
if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
Visit(TSI->getTypeLoc(), Sema::AbstractNone);
// TODO: other template argument types?
}
}
// Visit pointee types from a permissive context.
#define CheckPolymorphic(Type) \
void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
}
CheckPolymorphic(PointerTypeLoc)
CheckPolymorphic(ReferenceTypeLoc)
CheckPolymorphic(MemberPointerTypeLoc)
CheckPolymorphic(BlockPointerTypeLoc)
CheckPolymorphic(AtomicTypeLoc)
/// Handle all the types we haven't given a more specific
/// implementation for above.
void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
// Every other kind of type that we haven't called out already
// that has an inner type is either (1) sugar or (2) contains that
// inner type in some way as a subobject.
if (TypeLoc Next = TL.getNextTypeLoc())
return Visit(Next, Sel);
// If there's no inner type and we're in a permissive context,
// don't diagnose.
if (Sel == Sema::AbstractNone) return;
// Check whether the type matches the abstract type.
QualType T = TL.getType();
if (T->isArrayType()) {
Sel = Sema::AbstractArrayType;
T = Info.S.Context.getBaseElementType(T);
}
CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType();
if (CT != Info.AbstractType) return;
// It matched; do some magic.
// FIXME: These should be at most warnings. See P0929R2, CWG1640, CWG1646.
if (Sel == Sema::AbstractArrayType) {
Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
<< T << TL.getSourceRange();
} else {
Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
<< Sel << T << TL.getSourceRange();
}
Info.DiagnoseAbstractType();
}
};
void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
Sema::AbstractDiagSelID Sel) {
CheckAbstractUsage(*this, D).Visit(TL, Sel);
}
}
/// Check for invalid uses of an abstract type in a function declaration.
static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
FunctionDecl *FD) {
// No need to do the check on definitions, which require that
// the return/param types be complete.
if (FD->doesThisDeclarationHaveABody())
return;
// For safety's sake, just ignore it if we don't have type source
// information. This should never happen for non-implicit methods,
// but...
if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractNone);
}
/// Check for invalid uses of an abstract type in a variable0 declaration.
static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
VarDecl *VD) {
// No need to do the check on definitions, which require that
// the type is complete.
if (VD->isThisDeclarationADefinition())
return;
Info.CheckType(VD, VD->getTypeSourceInfo()->getTypeLoc(),
Sema::AbstractVariableType);
}
/// Check for invalid uses of an abstract type within a class definition.
static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
CXXRecordDecl *RD) {
for (auto *D : RD->decls()) {
if (D->isImplicit()) continue;
// Step through friends to the befriended declaration.
if (auto *FD = dyn_cast<FriendDecl>(D)) {
D = FD->getFriendDecl();
if (!D) continue;
}
// Functions and function templates.
if (auto *FD = dyn_cast<FunctionDecl>(D)) {
CheckAbstractClassUsage(Info, FD);
} else if (auto *FTD = dyn_cast<FunctionTemplateDecl>(D)) {
CheckAbstractClassUsage(Info, FTD->getTemplatedDecl());
// Fields and static variables.
} else if (auto *FD = dyn_cast<FieldDecl>(D)) {
if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
} else if (auto *VD = dyn_cast<VarDecl>(D)) {
CheckAbstractClassUsage(Info, VD);
} else if (auto *VTD = dyn_cast<VarTemplateDecl>(D)) {
CheckAbstractClassUsage(Info, VTD->getTemplatedDecl());
// Nested classes and class templates.
} else if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
CheckAbstractClassUsage(Info, RD);
} else if (auto *CTD = dyn_cast<ClassTemplateDecl>(D)) {
CheckAbstractClassUsage(Info, CTD->getTemplatedDecl());
}
}
}
static void ReferenceDllExportedMembers(Sema &S, CXXRecordDecl *Class) {
Attr *ClassAttr = getDLLAttr(Class);
if (!ClassAttr)
return;
assert(ClassAttr->getKind() == attr::DLLExport);
TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();
if (TSK == TSK_ExplicitInstantiationDeclaration)
// Don't go any further if this is just an explicit instantiation
// declaration.
return;
// Add a context note to explain how we got to any diagnostics produced below.
struct MarkingClassDllexported {
Sema &S;
MarkingClassDllexported(Sema &S, CXXRecordDecl *Class,
SourceLocation AttrLoc)
: S(S) {
Sema::CodeSynthesisContext Ctx;
Ctx.Kind = Sema::CodeSynthesisContext::MarkingClassDllexported;
Ctx.PointOfInstantiation = AttrLoc;
Ctx.Entity = Class;
S.pushCodeSynthesisContext(Ctx);
}
~MarkingClassDllexported() {
S.popCodeSynthesisContext();
}
} MarkingDllexportedContext(S, Class, ClassAttr->getLocation());
if (S.Context.getTargetInfo().getTriple().isWindowsGNUEnvironment())
S.MarkVTableUsed(Class->getLocation(), Class, true);
for (Decl *Member : Class->decls()) {
// Skip members that were not marked exported.
if (!Member->hasAttr<DLLExportAttr>())
continue;
// Defined static variables that are members of an exported base
// class must be marked export too.
auto *VD = dyn_cast<VarDecl>(Member);
if (VD && VD->getStorageClass() == SC_Static &&
TSK == TSK_ImplicitInstantiation)
S.MarkVariableReferenced(VD->getLocation(), VD);
auto *MD = dyn_cast<CXXMethodDecl>(Member);
if (!MD)
continue;
if (MD->isUserProvided()) {
// Instantiate non-default class member functions ...
// .. except for certain kinds of template specializations.
if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited())
continue;
// If this is an MS ABI dllexport default constructor, instantiate any
// default arguments.
if (S.Context.getTargetInfo().getCXXABI().isMicrosoft()) {
auto *CD = dyn_cast<CXXConstructorDecl>(MD);
if (CD && CD->isDefaultConstructor() && TSK == TSK_Undeclared) {
S.InstantiateDefaultCtorDefaultArgs(CD);
}
}
S.MarkFunctionReferenced(Class->getLocation(), MD);
// The function will be passed to the consumer when its definition is
// encountered.
} else if (MD->isExplicitlyDefaulted()) {
// Synthesize and instantiate explicitly defaulted methods.
S.MarkFunctionReferenced(Class->getLocation(), MD);
if (TSK != TSK_ExplicitInstantiationDefinition) {
// Except for explicit instantiation defs, we will not see the
// definition again later, so pass it to the consumer now.
S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD));
}
} else if (!MD->isTrivial() ||
MD->isCopyAssignmentOperator() ||
MD->isMoveAssignmentOperator()) {
// Synthesize and instantiate non-trivial implicit methods, and the copy
// and move assignment operators. The latter are exported even if they
// are trivial, because the address of an operator can be taken and
// should compare equal across libraries.
S.MarkFunctionReferenced(Class->getLocation(), MD);
// There is no later point when we will see the definition of this
// function, so pass it to the consumer now.
S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD));
}
}
}
static void checkForMultipleExportedDefaultConstructors(Sema &S,
CXXRecordDecl *Class) {
// Only the MS ABI has default constructor closures, so we don't need to do
// this semantic checking anywhere else.
if (!S.Context.getTargetInfo().getCXXABI().isMicrosoft())
return;
CXXConstructorDecl *LastExportedDefaultCtor = nullptr;
for (Decl *Member : Class->decls()) {
// Look for exported default constructors.
auto *CD = dyn_cast<CXXConstructorDecl>(Member);
if (!CD || !CD->isDefaultConstructor())
continue;
auto *Attr = CD->getAttr<DLLExportAttr>();
if (!Attr)
continue;
// If the class is non-dependent, mark the default arguments as ODR-used so
// that we can properly codegen the constructor closure.
if (!Class->isDependentContext()) {
for (ParmVarDecl *PD : CD->parameters()) {
(void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), CD, PD);
S.DiscardCleanupsInEvaluationContext();
}
}
if (LastExportedDefaultCtor) {
S.Diag(LastExportedDefaultCtor->getLocation(),
diag::err_attribute_dll_ambiguous_default_ctor)
<< Class;
S.Diag(CD->getLocation(), diag::note_entity_declared_at)
<< CD->getDeclName();
return;
}
LastExportedDefaultCtor = CD;
}
}
static void checkCUDADeviceBuiltinSurfaceClassTemplate(Sema &S,
CXXRecordDecl *Class) {
bool ErrorReported = false;
auto reportIllegalClassTemplate = [&ErrorReported](Sema &S,
ClassTemplateDecl *TD) {
if (ErrorReported)
return;
S.Diag(TD->getLocation(),
diag::err_cuda_device_builtin_surftex_cls_template)
<< /*surface*/ 0 << TD;
ErrorReported = true;
};
ClassTemplateDecl *TD = Class->getDescribedClassTemplate();
if (!TD) {
auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(Class);
if (!SD) {
S.Diag(Class->getLocation(),
diag::err_cuda_device_builtin_surftex_ref_decl)
<< /*surface*/ 0 << Class;
S.Diag(Class->getLocation(),
diag::note_cuda_device_builtin_surftex_should_be_template_class)
<< Class;
return;
}
TD = SD->getSpecializedTemplate();
}
TemplateParameterList *Params = TD->getTemplateParameters();
unsigned N = Params->size();
if (N != 2) {
reportIllegalClassTemplate(S, TD);
S.Diag(TD->getLocation(),
diag::note_cuda_device_builtin_surftex_cls_should_have_n_args)
<< TD << 2;
}
if (N > 0 && !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
reportIllegalClassTemplate(S, TD);
S.Diag(TD->getLocation(),
diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
<< TD << /*1st*/ 0 << /*type*/ 0;
}
if (N > 1) {
auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(1));
if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) {
reportIllegalClassTemplate(S, TD);
S.Diag(TD->getLocation(),
diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
<< TD << /*2nd*/ 1 << /*integer*/ 1;
}
}
}
static void checkCUDADeviceBuiltinTextureClassTemplate(Sema &S,
CXXRecordDecl *Class) {
bool ErrorReported = false;
auto reportIllegalClassTemplate = [&ErrorReported](Sema &S,
ClassTemplateDecl *TD) {
if (ErrorReported)
return;
S.Diag(TD->getLocation(),
diag::err_cuda_device_builtin_surftex_cls_template)
<< /*texture*/ 1 << TD;
ErrorReported = true;
};
ClassTemplateDecl *TD = Class->getDescribedClassTemplate();
if (!TD) {
auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(Class);
if (!SD) {
S.Diag(Class->getLocation(),
diag::err_cuda_device_builtin_surftex_ref_decl)
<< /*texture*/ 1 << Class;
S.Diag(Class->getLocation(),
diag::note_cuda_device_builtin_surftex_should_be_template_class)
<< Class;
return;
}
TD = SD->getSpecializedTemplate();
}
TemplateParameterList *Params = TD->getTemplateParameters();
unsigned N = Params->size();
if (N != 3) {
reportIllegalClassTemplate(S, TD);
S.Diag(TD->getLocation(),
diag::note_cuda_device_builtin_surftex_cls_should_have_n_args)
<< TD << 3;
}
if (N > 0 && !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
reportIllegalClassTemplate(S, TD);
S.Diag(TD->getLocation(),
diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
<< TD << /*1st*/ 0 << /*type*/ 0;
}
if (N > 1) {
auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(1));
if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) {
reportIllegalClassTemplate(S, TD);
S.Diag(TD->getLocation(),
diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
<< TD << /*2nd*/ 1 << /*integer*/ 1;
}
}
if (N > 2) {
auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(2));
if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) {
reportIllegalClassTemplate(S, TD);
S.Diag(TD->getLocation(),
diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
<< TD << /*3rd*/ 2 << /*integer*/ 1;
}
}
}
void Sema::checkClassLevelCodeSegAttribute(CXXRecordDecl *Class) {
// Mark any compiler-generated routines with the implicit code_seg attribute.
for (auto *Method : Class->methods()) {
if (Method->isUserProvided())
continue;
if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
Method->addAttr(A);
}
}
/// Check class-level dllimport/dllexport attribute.
void Sema::checkClassLevelDLLAttribute(CXXRecordDecl *Class) {
Attr *ClassAttr = getDLLAttr(Class);
// MSVC inherits DLL attributes to partial class template specializations.
if (Context.getTargetInfo().shouldDLLImportComdatSymbols() && !ClassAttr) {
if (auto *Spec = dyn_cast<ClassTemplatePartialSpecializationDecl>(Class)) {
if (Attr *TemplateAttr =
getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) {
auto *A = cast<InheritableAttr>(TemplateAttr->clone(getASTContext()));
A->setInherited(true);
ClassAttr = A;
}
}
}
if (!ClassAttr)
return;
if (!Class->isExternallyVisible()) {
Diag(Class->getLocation(), diag::err_attribute_dll_not_extern)
<< Class << ClassAttr;
return;
}
if (Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
!ClassAttr->isInherited()) {
// Diagnose dll attributes on members of class with dll attribute.
for (Decl *Member : Class->decls()) {
if (!isa<VarDecl>(Member) && !isa<CXXMethodDecl>(Member))
continue;
InheritableAttr *MemberAttr = getDLLAttr(Member);
if (!MemberAttr || MemberAttr->isInherited() || Member->isInvalidDecl())
continue;
Diag(MemberAttr->getLocation(),
diag::err_attribute_dll_member_of_dll_class)
<< MemberAttr << ClassAttr;
Diag(ClassAttr->getLocation(), diag::note_previous_attribute);
Member->setInvalidDecl();
}
}
if (Class->getDescribedClassTemplate())
// Don't inherit dll attribute until the template is instantiated.
return;
// The class is either imported or exported.
const bool ClassExported = ClassAttr->getKind() == attr::DLLExport;
// Check if this was a dllimport attribute propagated from a derived class to
// a base class template specialization. We don't apply these attributes to
// static data members.
const bool PropagatedImport =
!ClassExported &&
cast<DLLImportAttr>(ClassAttr)->wasPropagatedToBaseTemplate();
TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();
// Ignore explicit dllexport on explicit class template instantiation
// declarations, except in MinGW mode.
if (ClassExported && !ClassAttr->isInherited() &&
TSK == TSK_ExplicitInstantiationDeclaration &&
!Context.getTargetInfo().getTriple().isWindowsGNUEnvironment()) {
Class->dropAttr<DLLExportAttr>();
return;
}
// Force declaration of implicit members so they can inherit the attribute.
ForceDeclarationOfImplicitMembers(Class);
// FIXME: MSVC's docs say all bases must be exportable, but this doesn't
// seem to be true in practice?
for (Decl *Member : Class->decls()) {
VarDecl *VD = dyn_cast<VarDecl>(Member);
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
// Only methods and static fields inherit the attributes.
if (!VD && !MD)
continue;
if (MD) {
// Don't process deleted methods.
if (MD->isDeleted())
continue;
if (MD->isInlined()) {
// MinGW does not import or export inline methods. But do it for
// template instantiations.
if (!Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
TSK != TSK_ExplicitInstantiationDeclaration &&
TSK != TSK_ExplicitInstantiationDefinition)
continue;
// MSVC versions before 2015 don't export the move assignment operators
// and move constructor, so don't attempt to import/export them if
// we have a definition.
auto *Ctor = dyn_cast<CXXConstructorDecl>(MD);
if ((MD->isMoveAssignmentOperator() ||
(Ctor && Ctor->isMoveConstructor())) &&
!getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015))
continue;
// MSVC2015 doesn't export trivial defaulted x-tor but copy assign
// operator is exported anyway.
if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
(Ctor || isa<CXXDestructorDecl>(MD)) && MD->isTrivial())
continue;
}
}
// Don't apply dllimport attributes to static data members of class template
// instantiations when the attribute is propagated from a derived class.
if (VD && PropagatedImport)
continue;
if (!cast<NamedDecl>(Member)->isExternallyVisible())
continue;
if (!getDLLAttr(Member)) {
InheritableAttr *NewAttr = nullptr;
// Do not export/import inline function when -fno-dllexport-inlines is
// passed. But add attribute for later local static var check.
if (!getLangOpts().DllExportInlines && MD && MD->isInlined() &&
TSK != TSK_ExplicitInstantiationDeclaration &&
TSK != TSK_ExplicitInstantiationDefinition) {
if (ClassExported) {
NewAttr = ::new (getASTContext())
DLLExportStaticLocalAttr(getASTContext(), *ClassAttr);
} else {
NewAttr = ::new (getASTContext())
DLLImportStaticLocalAttr(getASTContext(), *ClassAttr);
}
} else {
NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
}
NewAttr->setInherited(true);
Member->addAttr(NewAttr);
if (MD) {
// Propagate DLLAttr to friend re-declarations of MD that have already
// been constructed.
for (FunctionDecl *FD = MD->getMostRecentDecl(); FD;
FD = FD->getPreviousDecl()) {
if (FD->getFriendObjectKind() == Decl::FOK_None)
continue;
assert(!getDLLAttr(FD) &&
"friend re-decl should not already have a DLLAttr");
NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
NewAttr->setInherited(true);
FD->addAttr(NewAttr);
}
}
}
}
if (ClassExported)
DelayedDllExportClasses.push_back(Class);
}
/// Perform propagation of DLL attributes from a derived class to a
/// templated base class for MS compatibility.
void Sema::propagateDLLAttrToBaseClassTemplate(
CXXRecordDecl *Class, Attr *ClassAttr,
ClassTemplateSpecializationDecl *BaseTemplateSpec, SourceLocation BaseLoc) {
if (getDLLAttr(
BaseTemplateSpec->getSpecializedTemplate()->getTemplatedDecl())) {
// If the base class template has a DLL attribute, don't try to change it.
return;
}
auto TSK = BaseTemplateSpec->getSpecializationKind();
if (!getDLLAttr(BaseTemplateSpec) &&
(TSK == TSK_Undeclared || TSK == TSK_ExplicitInstantiationDeclaration ||
TSK == TSK_ImplicitInstantiation)) {
// The template hasn't been instantiated yet (or it has, but only as an
// explicit instantiation declaration or implicit instantiation, which means
// we haven't codegenned any members yet), so propagate the attribute.
auto *NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
NewAttr->setInherited(true);
BaseTemplateSpec->addAttr(NewAttr);
// If this was an import, mark that we propagated it from a derived class to
// a base class template specialization.
if (auto *ImportAttr = dyn_cast<DLLImportAttr>(NewAttr))
ImportAttr->setPropagatedToBaseTemplate();
// If the template is already instantiated, checkDLLAttributeRedeclaration()
// needs to be run again to work see the new attribute. Otherwise this will
// get run whenever the template is instantiated.
if (TSK != TSK_Undeclared)
checkClassLevelDLLAttribute(BaseTemplateSpec);
return;
}
if (getDLLAttr(BaseTemplateSpec)) {
// The template has already been specialized or instantiated with an
// attribute, explicitly or through propagation. We should not try to change
// it.
return;
}
// The template was previously instantiated or explicitly specialized without
// a dll attribute, It's too late for us to add an attribute, so warn that
// this is unsupported.
Diag(BaseLoc, diag::warn_attribute_dll_instantiated_base_class)
<< BaseTemplateSpec->isExplicitSpecialization();
Diag(ClassAttr->getLocation(), diag::note_attribute);
if (BaseTemplateSpec->isExplicitSpecialization()) {
Diag(BaseTemplateSpec->getLocation(),
diag::note_template_class_explicit_specialization_was_here)
<< BaseTemplateSpec;
} else {
Diag(BaseTemplateSpec->getPointOfInstantiation(),
diag::note_template_class_instantiation_was_here)
<< BaseTemplateSpec;
}
}
/// Determine the kind of defaulting that would be done for a given function.
///
/// If the function is both a default constructor and a copy / move constructor
/// (due to having a default argument for the first parameter), this picks
/// CXXDefaultConstructor.
///
/// FIXME: Check that case is properly handled by all callers.
Sema::DefaultedFunctionKind
Sema::getDefaultedFunctionKind(const FunctionDecl *FD) {
if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(FD)) {
if (Ctor->isDefaultConstructor())
return Sema::CXXDefaultConstructor;
if (Ctor->isCopyConstructor())
return Sema::CXXCopyConstructor;
if (Ctor->isMoveConstructor())
return Sema::CXXMoveConstructor;
}
if (MD->isCopyAssignmentOperator())
return Sema::CXXCopyAssignment;
if (MD->isMoveAssignmentOperator())
return Sema::CXXMoveAssignment;
if (isa<CXXDestructorDecl>(FD))
return Sema::CXXDestructor;
}
switch (FD->getDeclName().getCXXOverloadedOperator()) {
case OO_EqualEqual:
return DefaultedComparisonKind::Equal;
case OO_ExclaimEqual:
return DefaultedComparisonKind::NotEqual;
case OO_Spaceship:
// No point allowing this if <=> doesn't exist in the current language mode.
if (!getLangOpts().CPlusPlus20)
break;
return DefaultedComparisonKind::ThreeWay;
case OO_Less:
case OO_LessEqual:
case OO_Greater:
case OO_GreaterEqual:
// No point allowing this if <=> doesn't exist in the current language mode.
if (!getLangOpts().CPlusPlus20)
break;
return DefaultedComparisonKind::Relational;
default:
break;
}
// Not defaultable.
return DefaultedFunctionKind();
}
static void DefineDefaultedFunction(Sema &S, FunctionDecl *FD,
SourceLocation DefaultLoc) {
Sema::DefaultedFunctionKind DFK = S.getDefaultedFunctionKind(FD);
if (DFK.isComparison())
return S.DefineDefaultedComparison(DefaultLoc, FD, DFK.asComparison());
switch (DFK.asSpecialMember()) {
case Sema::CXXDefaultConstructor:
S.DefineImplicitDefaultConstructor(DefaultLoc,
cast<CXXConstructorDecl>(FD));
break;
case Sema::CXXCopyConstructor:
S.DefineImplicitCopyConstructor(DefaultLoc, cast<CXXConstructorDecl>(FD));
break;
case Sema::CXXCopyAssignment:
S.DefineImplicitCopyAssignment(DefaultLoc, cast<CXXMethodDecl>(FD));
break;
case Sema::CXXDestructor:
S.DefineImplicitDestructor(DefaultLoc, cast<CXXDestructorDecl>(FD));
break;
case Sema::CXXMoveConstructor:
S.DefineImplicitMoveConstructor(DefaultLoc, cast<CXXConstructorDecl>(FD));
break;
case Sema::CXXMoveAssignment:
S.DefineImplicitMoveAssignment(DefaultLoc, cast<CXXMethodDecl>(FD));
break;
case Sema::CXXInvalid:
llvm_unreachable("Invalid special member.");
}
}
/// Determine whether a type is permitted to be passed or returned in
/// registers, per C++ [class.temporary]p3.
static bool canPassInRegisters(Sema &S, CXXRecordDecl *D,
TargetInfo::CallingConvKind CCK) {
if (D->isDependentType() || D->isInvalidDecl())
return false;
// Clang <= 4 used the pre-C++11 rule, which ignores move operations.
// The PS4 platform ABI follows the behavior of Clang 3.2.
if (CCK == TargetInfo::CCK_ClangABI4OrPS4)
return !D->hasNonTrivialDestructorForCall() &&
!D->hasNonTrivialCopyConstructorForCall();
if (CCK == TargetInfo::CCK_MicrosoftWin64) {
bool CopyCtorIsTrivial = false, CopyCtorIsTrivialForCall = false;
bool DtorIsTrivialForCall = false;
// If a class has at least one non-deleted, trivial copy constructor, it
// is passed according to the C ABI. Otherwise, it is passed indirectly.
//
// Note: This permits classes with non-trivial copy or move ctors to be
// passed in registers, so long as they *also* have a trivial copy ctor,
// which is non-conforming.
if (D->needsImplicitCopyConstructor()) {
if (!D->defaultedCopyConstructorIsDeleted()) {
if (D->hasTrivialCopyConstructor())
CopyCtorIsTrivial = true;
if (D->hasTrivialCopyConstructorForCall())
CopyCtorIsTrivialForCall = true;
}
} else {
for (const CXXConstructorDecl *CD : D->ctors()) {
if (CD->isCopyConstructor() && !CD->isDeleted()) {
if (CD->isTrivial())
CopyCtorIsTrivial = true;
if (CD->isTrivialForCall())
CopyCtorIsTrivialForCall = true;
}
}
}
if (D->needsImplicitDestructor()) {
if (!D->defaultedDestructorIsDeleted() &&
D->hasTrivialDestructorForCall())
DtorIsTrivialForCall = true;
} else if (const auto *DD = D->getDestructor()) {
if (!DD->isDeleted() && DD->isTrivialForCall())
DtorIsTrivialForCall = true;
}
// If the copy ctor and dtor are both trivial-for-calls, pass direct.
if (CopyCtorIsTrivialForCall && DtorIsTrivialForCall)
return true;
// If a class has a destructor, we'd really like to pass it indirectly
// because it allows us to elide copies. Unfortunately, MSVC makes that
// impossible for small types, which it will pass in a single register or
// stack slot. Most objects with dtors are large-ish, so handle that early.
// We can't call out all large objects as being indirect because there are
// multiple x64 calling conventions and the C++ ABI code shouldn't dictate
// how we pass large POD types.
// Note: This permits small classes with nontrivial destructors to be
// passed in registers, which is non-conforming.
bool isAArch64 = S.Context.getTargetInfo().getTriple().isAArch64();
uint64_t TypeSize = isAArch64 ? 128 : 64;
if (CopyCtorIsTrivial &&
S.getASTContext().getTypeSize(D->getTypeForDecl()) <= TypeSize)
return true;
return false;
}
// Per C++ [class.temporary]p3, the relevant condition is:
// each copy constructor, move constructor, and destructor of X is
// either trivial or deleted, and X has at least one non-deleted copy
// or move constructor
bool HasNonDeletedCopyOrMove = false;
if (D->needsImplicitCopyConstructor() &&
!D->defaultedCopyConstructorIsDeleted()) {
if (!D->hasTrivialCopyConstructorForCall())
return false;
HasNonDeletedCopyOrMove = true;
}
if (S.getLangOpts().CPlusPlus11 && D->needsImplicitMoveConstructor() &&
!D->defaultedMoveConstructorIsDeleted()) {
if (!D->hasTrivialMoveConstructorForCall())
return false;
HasNonDeletedCopyOrMove = true;
}
if (D->needsImplicitDestructor() && !D->defaultedDestructorIsDeleted() &&
!D->hasTrivialDestructorForCall())
return false;
for (const CXXMethodDecl *MD : D->methods()) {
if (MD->isDeleted())
continue;
auto *CD = dyn_cast<CXXConstructorDecl>(MD);
if (CD && CD->isCopyOrMoveConstructor())
HasNonDeletedCopyOrMove = true;
else if (!isa<CXXDestructorDecl>(MD))
continue;
if (!MD->isTrivialForCall())
return false;
}
return HasNonDeletedCopyOrMove;
}
/// Report an error regarding overriding, along with any relevant
/// overridden methods.
///
/// \param DiagID the primary error to report.
/// \param MD the overriding method.
static bool
ReportOverrides(Sema &S, unsigned DiagID, const CXXMethodDecl *MD,
llvm::function_ref<bool(const CXXMethodDecl *)> Report) {
bool IssuedDiagnostic = false;
for (const CXXMethodDecl *O : MD->overridden_methods()) {
if (Report(O)) {
if (!IssuedDiagnostic) {
S.Diag(MD->getLocation(), DiagID) << MD->getDeclName();
IssuedDiagnostic = true;
}
S.Diag(O->getLocation(), diag::note_overridden_virtual_function);
}
}
return IssuedDiagnostic;
}
/// Perform semantic checks on a class definition that has been
/// completing, introducing implicitly-declared members, checking for
/// abstract types, etc.
///
/// \param S The scope in which the class was parsed. Null if we didn't just
/// parse a class definition.
/// \param Record The completed class.
void Sema::CheckCompletedCXXClass(Scope *S, CXXRecordDecl *Record) {
if (!Record)
return;
if (Record->isAbstract() && !Record->isInvalidDecl()) {
AbstractUsageInfo Info(*this, Record);
CheckAbstractClassUsage(Info, Record);
}
// If this is not an aggregate type and has no user-declared constructor,
// complain about any non-static data members of reference or const scalar
// type, since they will never get initializers.
if (!Record->isInvalidDecl() && !Record->isDependentType() &&
!Record->isAggregate() && !Record->hasUserDeclaredConstructor() &&
!Record->isLambda()) {
bool Complained = false;
for (const auto *F : Record->fields()) {
if (F->hasInClassInitializer() || F->isUnnamedBitfield())
continue;
if (F->getType()->isReferenceType() ||
(F->getType().isConstQualified() && F->getType()->isScalarType())) {
if (!Complained) {
Diag(Record->getLocation(), diag::warn_no_constructor_for_refconst)
<< Record->getTagKind() << Record;
Complained = true;
}
Diag(F->getLocation(), diag::note_refconst_member_not_initialized)
<< F->getType()->isReferenceType()
<< F->getDeclName();
}
}
}
if (Record->getIdentifier()) {
// C++ [class.mem]p13:
// If T is the name of a class, then each of the following shall have a
// name different from T:
// - every member of every anonymous union that is a member of class T.
//
// C++ [class.mem]p14:
// In addition, if class T has a user-declared constructor (12.1), every
// non-static data member of class T shall have a name different from T.
DeclContext::lookup_result R = Record->lookup(Record->getDeclName());
for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E;
++I) {
NamedDecl *D = (*I)->getUnderlyingDecl();
if (((isa<FieldDecl>(D) || isa<UnresolvedUsingValueDecl>(D)) &&
Record->hasUserDeclaredConstructor()) ||
isa<IndirectFieldDecl>(D)) {
Diag((*I)->getLocation(), diag::err_member_name_of_class)
<< D->getDeclName();
break;
}
}
}
// Warn if the class has virtual methods but non-virtual public destructor.
if (Record->isPolymorphic() && !Record->isDependentType()) {
CXXDestructorDecl *dtor = Record->getDestructor();
if ((!dtor || (!dtor->isVirtual() && dtor->getAccess() == AS_public)) &&
!Record->hasAttr<FinalAttr>())
Diag(dtor ? dtor->getLocation() : Record->getLocation(),
diag::warn_non_virtual_dtor) << Context.getRecordType(Record);
}
if (Record->isAbstract()) {
if (FinalAttr *FA = Record->getAttr<FinalAttr>()) {
Diag(Record->getLocation(), diag::warn_abstract_final_class)
<< FA->isSpelledAsSealed();
DiagnoseAbstractType(Record);
}
}
// Warn if the class has a final destructor but is not itself marked final.
if (!Record->hasAttr<FinalAttr>()) {
if (const CXXDestructorDecl *dtor = Record->getDestructor()) {
if (const FinalAttr *FA = dtor->getAttr<FinalAttr>()) {
Diag(FA->getLocation(), diag::warn_final_dtor_non_final_class)
<< FA->isSpelledAsSealed()
<< FixItHint::CreateInsertion(
getLocForEndOfToken(Record->getLocation()),
(FA->isSpelledAsSealed() ? " sealed" : " final"));
Diag(Record->getLocation(),
diag::note_final_dtor_non_final_class_silence)
<< Context.getRecordType(Record) << FA->isSpelledAsSealed();
}
}
}
// See if trivial_abi has to be dropped.
if (Record->hasAttr<TrivialABIAttr>())
checkIllFormedTrivialABIStruct(*Record);
// Set HasTrivialSpecialMemberForCall if the record has attribute
// "trivial_abi".
bool HasTrivialABI = Record->hasAttr<TrivialABIAttr>();
if (HasTrivialABI)
Record->setHasTrivialSpecialMemberForCall();
// Explicitly-defaulted secondary comparison functions (!=, <, <=, >, >=).
// We check these last because they can depend on the properties of the
// primary comparison functions (==, <=>).
llvm::SmallVector<FunctionDecl*, 5> DefaultedSecondaryComparisons;
// Perform checks that can't be done until we know all the properties of a
// member function (whether it's defaulted, deleted, virtual, overriding,
// ...).
auto CheckCompletedMemberFunction = [&](CXXMethodDecl *MD) {
// A static function cannot override anything.
if (MD->getStorageClass() == SC_Static) {
if (ReportOverrides(*this, diag::err_static_overrides_virtual, MD,
[](const CXXMethodDecl *) { return true; }))
return;
}
// A deleted function cannot override a non-deleted function and vice
// versa.
if (ReportOverrides(*this,
MD->isDeleted() ? diag::err_deleted_override
: diag::err_non_deleted_override,
MD, [&](const CXXMethodDecl *V) {
return MD->isDeleted() != V->isDeleted();
})) {
if (MD->isDefaulted() && MD->isDeleted())
// Explain why this defaulted function was deleted.
DiagnoseDeletedDefaultedFunction(MD);
return;
}
// A consteval function cannot override a non-consteval function and vice
// versa.
if (ReportOverrides(*this,
MD->isConsteval() ? diag::err_consteval_override
: diag::err_non_consteval_override,
MD, [&](const CXXMethodDecl *V) {
return MD->isConsteval() != V->isConsteval();
})) {
if (MD->isDefaulted() && MD->isDeleted())
// Explain why this defaulted function was deleted.
DiagnoseDeletedDefaultedFunction(MD);
return;
}
};
auto CheckForDefaultedFunction = [&](FunctionDecl *FD) -> bool {
if (!FD || FD->isInvalidDecl() || !FD->isExplicitlyDefaulted())
return false;
DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD);
if (DFK.asComparison() == DefaultedComparisonKind::NotEqual ||
DFK.asComparison() == DefaultedComparisonKind::Relational) {
DefaultedSecondaryComparisons.push_back(FD);
return true;
}
CheckExplicitlyDefaultedFunction(S, FD);
return false;
};
auto CompleteMemberFunction = [&](CXXMethodDecl *M) {
// Check whether the explicitly-defaulted members are valid.
bool Incomplete = CheckForDefaultedFunction(M);
// Skip the rest of the checks for a member of a dependent class.
if (Record->isDependentType())
return;
// For an explicitly defaulted or deleted special member, we defer
// determining triviality until the class is complete. That time is now!
CXXSpecialMember CSM = getSpecialMember(M);
if (!M->isImplicit() && !M->isUserProvided()) {
if (CSM != CXXInvalid) {
M->setTrivial(SpecialMemberIsTrivial(M, CSM));
// Inform the class that we've finished declaring this member.
Record->finishedDefaultedOrDeletedMember(M);
M->setTrivialForCall(
HasTrivialABI ||
SpecialMemberIsTrivial(M, CSM, TAH_ConsiderTrivialABI));
Record->setTrivialForCallFlags(M);
}
}
// Set triviality for the purpose of calls if this is a user-provided
// copy/move constructor or destructor.
if ((CSM == CXXCopyConstructor || CSM == CXXMoveConstructor ||
CSM == CXXDestructor) && M->isUserProvided()) {
M->setTrivialForCall(HasTrivialABI);
Record->setTrivialForCallFlags(M);
}
if (!M->isInvalidDecl() && M->isExplicitlyDefaulted() &&
M->hasAttr<DLLExportAttr>()) {
if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
M->isTrivial() &&
(CSM == CXXDefaultConstructor || CSM == CXXCopyConstructor ||
CSM == CXXDestructor))
M->dropAttr<DLLExportAttr>();
if (M->hasAttr<DLLExportAttr>()) {
// Define after any fields with in-class initializers have been parsed.
DelayedDllExportMemberFunctions.push_back(M);
}
}
// Define defaulted constexpr virtual functions that override a base class
// function right away.
// FIXME: We can defer doing this until the vtable is marked as used.
if (M->isDefaulted() && M->isConstexpr() && M->size_overridden_methods())
DefineDefaultedFunction(*this, M, M->getLocation());
if (!Incomplete)
CheckCompletedMemberFunction(M);
};
// Check the destructor before any other member function. We need to
// determine whether it's trivial in order to determine whether the claas
// type is a literal type, which is a prerequisite for determining whether
// other special member functions are valid and whether they're implicitly
// 'constexpr'.
if (CXXDestructorDecl *Dtor = Record->getDestructor())
CompleteMemberFunction(Dtor);
bool HasMethodWithOverrideControl = false,
HasOverridingMethodWithoutOverrideControl = false;
for (auto *D : Record->decls()) {
if (auto *M = dyn_cast<CXXMethodDecl>(D)) {
// FIXME: We could do this check for dependent types with non-dependent
// bases.
if (!Record->isDependentType()) {
// See if a method overloads virtual methods in a base
// class without overriding any.
if (!M->isStatic())
DiagnoseHiddenVirtualMethods(M);
if (M->hasAttr<OverrideAttr>())
HasMethodWithOverrideControl = true;
else if (M->size_overridden_methods() > 0)
HasOverridingMethodWithoutOverrideControl = true;
}
if (!isa<CXXDestructorDecl>(M))
CompleteMemberFunction(M);
} else if (auto *F = dyn_cast<FriendDecl>(D)) {
CheckForDefaultedFunction(
dyn_cast_or_null<FunctionDecl>(F->getFriendDecl()));
}
}
if (HasOverridingMethodWithoutOverrideControl) {
bool HasInconsistentOverrideControl = HasMethodWithOverrideControl;
for (auto *M : Record->methods())
DiagnoseAbsenceOfOverrideControl(M, HasInconsistentOverrideControl);
}
// Check the defaulted secondary comparisons after any other member functions.
for (FunctionDecl *FD : DefaultedSecondaryComparisons) {
CheckExplicitlyDefaultedFunction(S, FD);
// If this is a member function, we deferred checking it until now.
if (auto *MD = dyn_cast<CXXMethodDecl>(FD))
CheckCompletedMemberFunction(MD);
}
// ms_struct is a request to use the same ABI rules as MSVC. Check
// whether this class uses any C++ features that are implemented
// completely differently in MSVC, and if so, emit a diagnostic.
// That diagnostic defaults to an error, but we allow projects to
// map it down to a warning (or ignore it). It's a fairly common
// practice among users of the ms_struct pragma to mass-annotate
// headers, sweeping up a bunch of types that the project doesn't
// really rely on MSVC-compatible layout for. We must therefore
// support "ms_struct except for C++ stuff" as a secondary ABI.
// Don't emit this diagnostic if the feature was enabled as a
// language option (as opposed to via a pragma or attribute), as
// the option -mms-bitfields otherwise essentially makes it impossible
// to build C++ code, unless this diagnostic is turned off.
if (Record->isMsStruct(Context) && !Context.getLangOpts().MSBitfields &&
(Record->isPolymorphic() || Record->getNumBases())) {
Diag(Record->getLocation(), diag::warn_cxx_ms_struct);
}
checkClassLevelDLLAttribute(Record);
checkClassLevelCodeSegAttribute(Record);
bool ClangABICompat4 =
Context.getLangOpts().getClangABICompat() <= LangOptions::ClangABI::Ver4;
TargetInfo::CallingConvKind CCK =
Context.getTargetInfo().getCallingConvKind(ClangABICompat4);
bool CanPass = canPassInRegisters(*this, Record, CCK);
// Do not change ArgPassingRestrictions if it has already been set to
// APK_CanNeverPassInRegs.
if (Record->getArgPassingRestrictions() != RecordDecl::APK_CanNeverPassInRegs)
Record->setArgPassingRestrictions(CanPass
? RecordDecl::APK_CanPassInRegs
: RecordDecl::APK_CannotPassInRegs);
// If canPassInRegisters returns true despite the record having a non-trivial
// destructor, the record is destructed in the callee. This happens only when
// the record or one of its subobjects has a field annotated with trivial_abi
// or a field qualified with ObjC __strong/__weak.
if (Context.getTargetInfo().getCXXABI().areArgsDestroyedLeftToRightInCallee())
Record->setParamDestroyedInCallee(true);
else if (Record->hasNonTrivialDestructor())
Record->setParamDestroyedInCallee(CanPass);
if (getLangOpts().ForceEmitVTables) {
// If we want to emit all the vtables, we need to mark it as used. This
// is especially required for cases like vtable assumption loads.
MarkVTableUsed(Record->getInnerLocStart(), Record);
}
if (getLangOpts().CUDA) {
if (Record->hasAttr<CUDADeviceBuiltinSurfaceTypeAttr>())
checkCUDADeviceBuiltinSurfaceClassTemplate(*this, Record);
else if (Record->hasAttr<CUDADeviceBuiltinTextureTypeAttr>())
checkCUDADeviceBuiltinTextureClassTemplate(*this, Record);
}
}
/// Look up the special member function that would be called by a special
/// member function for a subobject of class type.
///
/// \param Class The class type of the subobject.
/// \param CSM The kind of special member function.
/// \param FieldQuals If the subobject is a field, its cv-qualifiers.
/// \param ConstRHS True if this is a copy operation with a const object
/// on its RHS, that is, if the argument to the outer special member
/// function is 'const' and this is not a field marked 'mutable'.
static Sema::SpecialMemberOverloadResult lookupCallFromSpecialMember(
Sema &S, CXXRecordDecl *Class, Sema::CXXSpecialMember CSM,
unsigned FieldQuals, bool ConstRHS) {
unsigned LHSQuals = 0;
if (CSM == Sema::CXXCopyAssignment || CSM == Sema::CXXMoveAssignment)
LHSQuals = FieldQuals;
unsigned RHSQuals = FieldQuals;
if (CSM == Sema::CXXDefaultConstructor || CSM == Sema::CXXDestructor)
RHSQuals = 0;
else if (ConstRHS)
RHSQuals |= Qualifiers::Const;
return S.LookupSpecialMember(Class, CSM,
RHSQuals & Qualifiers::Const,
RHSQuals & Qualifiers::Volatile,
false,
LHSQuals & Qualifiers::Const,
LHSQuals & Qualifiers::Volatile);
}
class Sema::InheritedConstructorInfo {
Sema &S;
SourceLocation UseLoc;
/// A mapping from the base classes through which the constructor was
/// inherited to the using shadow declaration in that base class (or a null
/// pointer if the constructor was declared in that base class).
llvm::DenseMap<CXXRecordDecl *, ConstructorUsingShadowDecl *>
InheritedFromBases;
public:
InheritedConstructorInfo(Sema &S, SourceLocation UseLoc,
ConstructorUsingShadowDecl *Shadow)
: S(S), UseLoc(UseLoc) {
bool DiagnosedMultipleConstructedBases = false;
CXXRecordDecl *ConstructedBase = nullptr;
BaseUsingDecl *ConstructedBaseIntroducer = nullptr;
// Find the set of such base class subobjects and check that there's a
// unique constructed subobject.
for (auto *D : Shadow->redecls()) {
auto *DShadow = cast<ConstructorUsingShadowDecl>(D);
auto *DNominatedBase = DShadow->getNominatedBaseClass();
auto *DConstructedBase = DShadow->getConstructedBaseClass();
InheritedFromBases.insert(
std::make_pair(DNominatedBase->getCanonicalDecl(),
DShadow->getNominatedBaseClassShadowDecl()));
if (DShadow->constructsVirtualBase())
InheritedFromBases.insert(
std::make_pair(DConstructedBase->getCanonicalDecl(),
DShadow->getConstructedBaseClassShadowDecl()));
else
assert(DNominatedBase == DConstructedBase);
// [class.inhctor.init]p2:
// If the constructor was inherited from multiple base class subobjects
// of type B, the program is ill-formed.
if (!ConstructedBase) {
ConstructedBase = DConstructedBase;
ConstructedBaseIntroducer = D->getIntroducer();
} else if (ConstructedBase != DConstructedBase &&
!Shadow->isInvalidDecl()) {
if (!DiagnosedMultipleConstructedBases) {
S.Diag(UseLoc, diag::err_ambiguous_inherited_constructor)
<< Shadow->getTargetDecl();
S.Diag(ConstructedBaseIntroducer->getLocation(),
diag::note_ambiguous_inherited_constructor_using)
<< ConstructedBase;
DiagnosedMultipleConstructedBases = true;
}
S.Diag(D->getIntroducer()->getLocation(),
diag::note_ambiguous_inherited_constructor_using)
<< DConstructedBase;
}
}
if (DiagnosedMultipleConstructedBases)
Shadow->setInvalidDecl();
}
/// Find the constructor to use for inherited construction of a base class,
/// and whether that base class constructor inherits the constructor from a
/// virtual base class (in which case it won't actually invoke it).
std::pair<CXXConstructorDecl *, bool>
findConstructorForBase(CXXRecordDecl *Base, CXXConstructorDecl *Ctor) const {
auto It = InheritedFromBases.find(Base->getCanonicalDecl());
if (It == InheritedFromBases.end())
return std::make_pair(nullptr, false);
// This is an intermediary class.
if (It->second)
return std::make_pair(
S.findInheritingConstructor(UseLoc, Ctor, It->second),
It->second->constructsVirtualBase());
// This is the base class from which the constructor was inherited.
return std::make_pair(Ctor, false);
}
};
/// Is the special member function which would be selected to perform the
/// specified operation on the specified class type a constexpr constructor?
static bool
specialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl,
Sema::CXXSpecialMember CSM, unsigned Quals,
bool ConstRHS,
CXXConstructorDecl *InheritedCtor = nullptr,
Sema::InheritedConstructorInfo *Inherited = nullptr) {
// If we're inheriting a constructor, see if we need to call it for this base
// class.
if (InheritedCtor) {
assert(CSM == Sema::CXXDefaultConstructor);
auto BaseCtor =
Inherited->findConstructorForBase(ClassDecl, InheritedCtor).first;
if (BaseCtor)
return BaseCtor->isConstexpr();
}
if (CSM == Sema::CXXDefaultConstructor)
return ClassDecl->hasConstexprDefaultConstructor();
if (CSM == Sema::CXXDestructor)
return ClassDecl->hasConstexprDestructor();
Sema::SpecialMemberOverloadResult SMOR =
lookupCallFromSpecialMember(S, ClassDecl, CSM, Quals, ConstRHS);
if (!SMOR.getMethod())
// A constructor we wouldn't select can't be "involved in initializing"
// anything.
return true;
return SMOR.getMethod()->isConstexpr();
}
/// Determine whether the specified special member function would be constexpr
/// if it were implicitly defined.
static bool defaultedSpecialMemberIsConstexpr(
Sema &S, CXXRecordDecl *ClassDecl, Sema::CXXSpecialMember CSM,
bool ConstArg, CXXConstructorDecl *InheritedCtor = nullptr,
Sema::InheritedConstructorInfo *Inherited = nullptr) {
if (!S.getLangOpts().CPlusPlus11)
return false;
// C++11 [dcl.constexpr]p4:
// In the definition of a constexpr constructor [...]
bool Ctor = true;
switch (CSM) {
case Sema::CXXDefaultConstructor:
if (Inherited)
break;
// Since default constructor lookup is essentially trivial (and cannot
// involve, for instance, template instantiation), we compute whether a
// defaulted default constructor is constexpr directly within CXXRecordDecl.
//
// This is important for performance; we need to know whether the default
// constructor is constexpr to determine whether the type is a literal type.
return ClassDecl->defaultedDefaultConstructorIsConstexpr();
case Sema::CXXCopyConstructor:
case Sema::CXXMoveConstructor:
// For copy or move constructors, we need to perform overload resolution.
break;
case Sema::CXXCopyAssignment:
case Sema::CXXMoveAssignment:
if (!S.getLangOpts().CPlusPlus14)
return false;
// In C++1y, we need to perform overload resolution.
Ctor = false;
break;
case Sema::CXXDestructor:
return ClassDecl->defaultedDestructorIsConstexpr();
case Sema::CXXInvalid:
return false;
}
// -- if the class is a non-empty union, or for each non-empty anonymous
// union member of a non-union class, exactly one non-static data member
// shall be initialized; [DR1359]
//
// If we squint, this is guaranteed, since exactly one non-static data member
// will be initialized (if the constructor isn't deleted), we just don't know
// which one.
if (Ctor && ClassDecl->isUnion())
return CSM == Sema::CXXDefaultConstructor
? ClassDecl->hasInClassInitializer() ||
!ClassDecl->hasVariantMembers()
: true;
// -- the class shall not have any virtual base classes;
if (Ctor && ClassDecl->getNumVBases())
return false;
// C++1y [class.copy]p26:
// -- [the class] is a literal type, and
if (!Ctor && !ClassDecl->isLiteral())
return false;
// -- every constructor involved in initializing [...] base class
// sub-objects shall be a constexpr constructor;
// -- the assignment operator selected to copy/move each direct base
// class is a constexpr function, and
for (const auto &B : ClassDecl->bases()) {
const RecordType *BaseType = B.getType()->getAs<RecordType>();
if (!BaseType) continue;
CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
if (!specialMemberIsConstexpr(S, BaseClassDecl, CSM, 0, ConstArg,
InheritedCtor, Inherited))
return false;
}
// -- every constructor involved in initializing non-static data members
// [...] shall be a constexpr constructor;
// -- every non-static data member and base class sub-object shall be
// initialized
// -- for each non-static data member of X that is of class type (or array
// thereof), the assignment operator selected to copy/move that member is
// a constexpr function
for (const auto *F : ClassDecl->fields()) {
if (F->isInvalidDecl())
continue;
if (CSM == Sema::CXXDefaultConstructor && F->hasInClassInitializer())
continue;
QualType BaseType = S.Context.getBaseElementType(F->getType());
if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) {
CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
if (!specialMemberIsConstexpr(S, FieldRecDecl, CSM,
BaseType.getCVRQualifiers(),
ConstArg && !F->isMutable()))
return false;
} else if (CSM == Sema::CXXDefaultConstructor) {
return false;
}
}
// All OK, it's constexpr!
return true;
}
namespace {
/// RAII object to register a defaulted function as having its exception
/// specification computed.
struct ComputingExceptionSpec {
Sema &S;
ComputingExceptionSpec(Sema &S, FunctionDecl *FD, SourceLocation Loc)
: S(S) {
Sema::CodeSynthesisContext Ctx;
Ctx.Kind = Sema::CodeSynthesisContext::ExceptionSpecEvaluation;
Ctx.PointOfInstantiation = Loc;
Ctx.Entity = FD;
S.pushCodeSynthesisContext(Ctx);
}
~ComputingExceptionSpec() {
S.popCodeSynthesisContext();
}
};
}
static Sema::ImplicitExceptionSpecification
ComputeDefaultedSpecialMemberExceptionSpec(
Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
Sema::InheritedConstructorInfo *ICI);
static Sema::ImplicitExceptionSpecification
ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc,
FunctionDecl *FD,
Sema::DefaultedComparisonKind DCK);
static Sema::ImplicitExceptionSpecification
computeImplicitExceptionSpec(Sema &S, SourceLocation Loc, FunctionDecl *FD) {
auto DFK = S.getDefaultedFunctionKind(FD);
if (DFK.isSpecialMember())
return ComputeDefaultedSpecialMemberExceptionSpec(
S, Loc, cast<CXXMethodDecl>(FD), DFK.asSpecialMember(), nullptr);
if (DFK.isComparison())
return ComputeDefaultedComparisonExceptionSpec(S, Loc, FD,
DFK.asComparison());
auto *CD = cast<CXXConstructorDecl>(FD);
assert(CD->getInheritedConstructor() &&
"only defaulted functions and inherited constructors have implicit "
"exception specs");
Sema::InheritedConstructorInfo ICI(
S, Loc, CD->getInheritedConstructor().getShadowDecl());
return ComputeDefaultedSpecialMemberExceptionSpec(
S, Loc, CD, Sema::CXXDefaultConstructor, &ICI);
}
static FunctionProtoType::ExtProtoInfo getImplicitMethodEPI(Sema &S,
CXXMethodDecl *MD) {
FunctionProtoType::ExtProtoInfo EPI;
// Build an exception specification pointing back at this member.
EPI.ExceptionSpec.Type = EST_Unevaluated;
EPI.ExceptionSpec.SourceDecl = MD;
// Set the calling convention to the default for C++ instance methods.
EPI.ExtInfo = EPI.ExtInfo.withCallingConv(
S.Context.getDefaultCallingConvention(/*IsVariadic=*/false,
/*IsCXXMethod=*/true));
return EPI;
}
void Sema::EvaluateImplicitExceptionSpec(SourceLocation Loc, FunctionDecl *FD) {
const FunctionProtoType *FPT = FD->getType()->castAs<FunctionProtoType>();
if (FPT->getExceptionSpecType() != EST_Unevaluated)
return;
// Evaluate the exception specification.
auto IES = computeImplicitExceptionSpec(*this, Loc, FD);
auto ESI = IES.getExceptionSpec();
// Update the type of the special member to use it.
UpdateExceptionSpec(FD, ESI);
}
void Sema::CheckExplicitlyDefaultedFunction(Scope *S, FunctionDecl *FD) {
assert(FD->isExplicitlyDefaulted() && "not explicitly-defaulted");
DefaultedFunctionKind DefKind = getDefaultedFunctionKind(FD);
if (!DefKind) {
assert(FD->getDeclContext()->isDependentContext());
return;
}
if (DefKind.isComparison())
UnusedPrivateFields.clear();
if (DefKind.isSpecialMember()
? CheckExplicitlyDefaultedSpecialMember(cast<CXXMethodDecl>(FD),
DefKind.asSpecialMember())
: CheckExplicitlyDefaultedComparison(S, FD, DefKind.asComparison()))
FD->setInvalidDecl();
}
bool Sema::CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD,
CXXSpecialMember CSM) {
CXXRecordDecl *RD = MD->getParent();
assert(MD->isExplicitlyDefaulted() && CSM != CXXInvalid &&
"not an explicitly-defaulted special member");
// Defer all checking for special members of a dependent type.
if (RD->isDependentType())
return false;
// Whether this was the first-declared instance of the constructor.
// This affects whether we implicitly add an exception spec and constexpr.
bool First = MD == MD->getCanonicalDecl();
bool HadError = false;
// C++11 [dcl.fct.def.default]p1:
// A function that is explicitly defaulted shall
// -- be a special member function [...] (checked elsewhere),
// -- have the same type (except for ref-qualifiers, and except that a
// copy operation can take a non-const reference) as an implicit
// declaration, and
// -- not have default arguments.
// C++2a changes the second bullet to instead delete the function if it's
// defaulted on its first declaration, unless it's "an assignment operator,
// and its return type differs or its parameter type is not a reference".
bool DeleteOnTypeMismatch = getLangOpts().CPlusPlus20 && First;
bool ShouldDeleteForTypeMismatch = false;
unsigned ExpectedParams = 1;
if (CSM == CXXDefaultConstructor || CSM == CXXDestructor)
ExpectedParams = 0;
if (MD->getNumParams() != ExpectedParams) {
// This checks for default arguments: a copy or move constructor with a
// default argument is classified as a default constructor, and assignment
// operations and destructors can't have default arguments.
Diag(MD->getLocation(), diag::err_defaulted_special_member_params)
<< CSM << MD->getSourceRange();
HadError = true;
} else if (MD->isVariadic()) {
if (DeleteOnTypeMismatch)
ShouldDeleteForTypeMismatch = true;
else {
Diag(MD->getLocation(), diag::err_defaulted_special_member_variadic)
<< CSM << MD->getSourceRange();
HadError = true;
}
}
const FunctionProtoType *Type = MD->getType()->getAs<FunctionProtoType>();
bool CanHaveConstParam = false;
if (CSM == CXXCopyConstructor)
CanHaveConstParam = RD->implicitCopyConstructorHasConstParam();
else if (CSM == CXXCopyAssignment)
CanHaveConstParam = RD->implicitCopyAssignmentHasConstParam();
QualType ReturnType = Context.VoidTy;
if (CSM == CXXCopyAssignment || CSM == CXXMoveAssignment) {
// Check for return type matching.
ReturnType = Type->getReturnType();
QualType DeclType = Context.getTypeDeclType(RD);
DeclType = Context.getAddrSpaceQualType(DeclType, MD->getMethodQualifiers().getAddressSpace());
QualType ExpectedReturnType = Context.getLValueReferenceType(DeclType);
if (!Context.hasSameType(ReturnType, ExpectedReturnType)) {
Diag(MD->getLocation(), diag::err_defaulted_special_member_return_type)
<< (CSM == CXXMoveAssignment) << ExpectedReturnType;
HadError = true;
}
// A defaulted special member cannot have cv-qualifiers.
if (Type->getMethodQuals().hasConst() || Type->getMethodQuals().hasVolatile()) {
if (DeleteOnTypeMismatch)
ShouldDeleteForTypeMismatch = true;
else {
Diag(MD->getLocation(), diag::err_defaulted_special_member_quals)
<< (CSM == CXXMoveAssignment) << getLangOpts().CPlusPlus14;
HadError = true;
}
}
}
// Check for parameter type matching.
QualType ArgType = ExpectedParams ? Type->getParamType(0) : QualType();
bool HasConstParam = false;
if (ExpectedParams && ArgType->isReferenceType()) {
// Argument must be reference to possibly-const T.
QualType ReferentType = ArgType->getPointeeType();
HasConstParam = ReferentType.isConstQualified();
if (ReferentType.isVolatileQualified()) {
if (DeleteOnTypeMismatch)
ShouldDeleteForTypeMismatch = true;
else {
Diag(MD->getLocation(),
diag::err_defaulted_special_member_volatile_param) << CSM;
HadError = true;
}
}
if (HasConstParam && !CanHaveConstParam) {
if (DeleteOnTypeMismatch)
ShouldDeleteForTypeMismatch = true;
else if (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment) {
Diag(MD->getLocation(),
diag::err_defaulted_special_member_copy_const_param)
<< (CSM == CXXCopyAssignment);
// FIXME: Explain why this special member can't be const.
HadError = true;
} else {
Diag(MD->getLocation(),
diag::err_defaulted_special_member_move_const_param)
<< (CSM == CXXMoveAssignment);
HadError = true;
}
}
} else if (ExpectedParams) {
// A copy assignment operator can take its argument by value, but a
// defaulted one cannot.
assert(CSM == CXXCopyAssignment && "unexpected non-ref argument");
Diag(MD->getLocation(), diag::err_defaulted_copy_assign_not_ref);
HadError = true;
}
// C++11 [dcl.fct.def.default]p2:
// An explicitly-defaulted function may be declared constexpr only if it
// would have been implicitly declared as constexpr,
// Do not apply this rule to members of class templates, since core issue 1358
// makes such functions always instantiate to constexpr functions. For
// functions which cannot be constexpr (for non-constructors in C++11 and for
// destructors in C++14 and C++17), this is checked elsewhere.
//
// FIXME: This should not apply if the member is deleted.
bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, RD, CSM,
HasConstParam);
if ((getLangOpts().CPlusPlus20 ||
(getLangOpts().CPlusPlus14 ? !isa<CXXDestructorDecl>(MD)
: isa<CXXConstructorDecl>(MD))) &&
MD->isConstexpr() && !Constexpr &&
MD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) {
Diag(MD->getBeginLoc(), MD->isConsteval()
? diag::err_incorrect_defaulted_consteval
: diag::err_incorrect_defaulted_constexpr)
<< CSM;
// FIXME: Explain why the special member can't be constexpr.
HadError = true;
}
if (First) {
// C++2a [dcl.fct.def.default]p3:
// If a function is explicitly defaulted on its first declaration, it is
// implicitly considered to be constexpr if the implicit declaration
// would be.
MD->setConstexprKind(Constexpr ? (MD->isConsteval()
? ConstexprSpecKind::Consteval
: ConstexprSpecKind::Constexpr)
: ConstexprSpecKind::Unspecified);
if (!Type->hasExceptionSpec()) {
// C++2a [except.spec]p3:
// If a declaration of a function does not have a noexcept-specifier
// [and] is defaulted on its first declaration, [...] the exception
// specification is as specified below
FunctionProtoType::ExtProtoInfo EPI = Type->getExtProtoInfo();
EPI.ExceptionSpec.Type = EST_Unevaluated;
EPI.ExceptionSpec.SourceDecl = MD;
MD->setType(Context.getFunctionType(ReturnType,
llvm::makeArrayRef(&ArgType,
ExpectedParams),
EPI));
}
}
if (ShouldDeleteForTypeMismatch || ShouldDeleteSpecialMember(MD, CSM)) {
if (First) {
SetDeclDeleted(MD, MD->getLocation());
if (!inTemplateInstantiation() && !HadError) {
Diag(MD->getLocation(), diag::warn_defaulted_method_deleted) << CSM;
if (ShouldDeleteForTypeMismatch) {
Diag(MD->getLocation(), diag::note_deleted_type_mismatch) << CSM;
} else {
ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true);
}
}
if (ShouldDeleteForTypeMismatch && !HadError) {
Diag(MD->getLocation(),
diag::warn_cxx17_compat_defaulted_method_type_mismatch) << CSM;
}
} else {
// C++11 [dcl.fct.def.default]p4:
// [For a] user-provided explicitly-defaulted function [...] if such a
// function is implicitly defined as deleted, the program is ill-formed.
Diag(MD->getLocation(), diag::err_out_of_line_default_deletes) << CSM;
assert(!ShouldDeleteForTypeMismatch && "deleted non-first decl");
ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true);
HadError = true;
}
}
return HadError;
}
namespace {
/// Helper class for building and checking a defaulted comparison.
///
/// Defaulted functions are built in two phases:
///
/// * First, the set of operations that the function will perform are
/// identified, and some of them are checked. If any of the checked
/// operations is invalid in certain ways, the comparison function is
/// defined as deleted and no body is built.
/// * Then, if the function is not defined as deleted, the body is built.
///
/// This is accomplished by performing two visitation steps over the eventual
/// body of the function.
template<typename Derived, typename ResultList, typename Result,
typename Subobject>
class DefaultedComparisonVisitor {
public:
using DefaultedComparisonKind = Sema::DefaultedComparisonKind;
DefaultedComparisonVisitor(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
DefaultedComparisonKind DCK)
: S(S), RD(RD), FD(FD), DCK(DCK) {
if (auto *Info = FD->getDefaultedFunctionInfo()) {
// FIXME: Change CreateOverloadedBinOp to take an ArrayRef instead of an
// UnresolvedSet to avoid this copy.
Fns.assign(Info->getUnqualifiedLookups().begin(),
Info->getUnqualifiedLookups().end());
}
}
ResultList visit() {
// The type of an lvalue naming a parameter of this function.
QualType ParamLvalType =
FD->getParamDecl(0)->getType().getNonReferenceType();
ResultList Results;
switch (DCK) {
case DefaultedComparisonKind::None:
llvm_unreachable("not a defaulted comparison");
case DefaultedComparisonKind::Equal:
case DefaultedComparisonKind::ThreeWay:
getDerived().visitSubobjects(Results, RD, ParamLvalType.getQualifiers());
return Results;
case DefaultedComparisonKind::NotEqual:
case DefaultedComparisonKind::Relational:
Results.add(getDerived().visitExpandedSubobject(
ParamLvalType, getDerived().getCompleteObject()));
return Results;
}
llvm_unreachable("");
}
protected:
Derived &getDerived() { return static_cast<Derived&>(*this); }
/// Visit the expanded list of subobjects of the given type, as specified in
/// C++2a [class.compare.default].
///
/// \return \c true if the ResultList object said we're done, \c false if not.
bool visitSubobjects(ResultList &Results, CXXRecordDecl *Record,
Qualifiers Quals) {
// C++2a [class.compare.default]p4:
// The direct base class subobjects of C
for (CXXBaseSpecifier &Base : Record->bases())
if (Results.add(getDerived().visitSubobject(
S.Context.getQualifiedType(Base.getType(), Quals),
getDerived().getBase(&Base))))
return true;
// followed by the non-static data members of C
for (FieldDecl *Field : Record->fields()) {
// Recursively expand anonymous structs.
if (Field->isAnonymousStructOrUnion()) {
if (visitSubobjects(Results, Field->getType()->getAsCXXRecordDecl(),
Quals))
return true;
continue;
}
// Figure out the type of an lvalue denoting this field.
Qualifiers FieldQuals = Quals;
if (Field->isMutable())
FieldQuals.removeConst();
QualType FieldType =
S.Context.getQualifiedType(Field->getType(), FieldQuals);
if (Results.add(getDerived().visitSubobject(
FieldType, getDerived().getField(Field))))
return true;
}
// form a list of subobjects.
return false;
}
Result visitSubobject(QualType Type, Subobject Subobj) {
// In that list, any subobject of array type is recursively expanded
const ArrayType *AT = S.Context.getAsArrayType(Type);
if (auto *CAT = dyn_cast_or_null<ConstantArrayType>(AT))
return getDerived().visitSubobjectArray(CAT->getElementType(),
CAT->getSize(), Subobj);
return getDerived().visitExpandedSubobject(Type, Subobj);
}
Result visitSubobjectArray(QualType Type, const llvm::APInt &Size,
Subobject Subobj) {
return getDerived().visitSubobject(Type, Subobj);
}
protected:
Sema &S;
CXXRecordDecl *RD;
FunctionDecl *FD;
DefaultedComparisonKind DCK;
UnresolvedSet<16> Fns;
};
/// Information about a defaulted comparison, as determined by
/// DefaultedComparisonAnalyzer.
struct DefaultedComparisonInfo {
bool Deleted = false;
bool Constexpr = true;
ComparisonCategoryType Category = ComparisonCategoryType::StrongOrdering;
static DefaultedComparisonInfo deleted() {
DefaultedComparisonInfo Deleted;
Deleted.Deleted = true;
return Deleted;
}
bool add(const DefaultedComparisonInfo &R) {
Deleted |= R.Deleted;
Constexpr &= R.Constexpr;
Category = commonComparisonType(Category, R.Category);
return Deleted;
}
};
/// An element in the expanded list of subobjects of a defaulted comparison, as
/// specified in C++2a [class.compare.default]p4.
struct DefaultedComparisonSubobject {
enum { CompleteObject, Member, Base } Kind;
NamedDecl *Decl;
SourceLocation Loc;
};
/// A visitor over the notional body of a defaulted comparison that determines
/// whether that body would be deleted or constexpr.
class DefaultedComparisonAnalyzer
: public DefaultedComparisonVisitor<DefaultedComparisonAnalyzer,
DefaultedComparisonInfo,
DefaultedComparisonInfo,
DefaultedComparisonSubobject> {
public:
enum DiagnosticKind { NoDiagnostics, ExplainDeleted, ExplainConstexpr };
private:
DiagnosticKind Diagnose;
public:
using Base = DefaultedComparisonVisitor;
using Result = DefaultedComparisonInfo;
using Subobject = DefaultedComparisonSubobject;
friend Base;
DefaultedComparisonAnalyzer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
DefaultedComparisonKind DCK,
DiagnosticKind Diagnose = NoDiagnostics)
: Base(S, RD, FD, DCK), Diagnose(Diagnose) {}
Result visit() {
if ((DCK == DefaultedComparisonKind::Equal ||
DCK == DefaultedComparisonKind::ThreeWay) &&
RD->hasVariantMembers()) {
// C++2a [class.compare.default]p2 [P2002R0]:
// A defaulted comparison operator function for class C is defined as
// deleted if [...] C has variant members.
if (Diagnose == ExplainDeleted) {
S.Diag(FD->getLocation(), diag::note_defaulted_comparison_union)
<< FD << RD->isUnion() << RD;
}
return Result::deleted();
}
return Base::visit();
}
private:
Subobject getCompleteObject() {
return Subobject{Subobject::CompleteObject, RD, FD->getLocation()};
}
Subobject getBase(CXXBaseSpecifier *Base) {
return Subobject{Subobject::Base, Base->getType()->getAsCXXRecordDecl(),
Base->getBaseTypeLoc()};
}
Subobject getField(FieldDecl *Field) {
return Subobject{Subobject::Member, Field, Field->getLocation()};
}
Result visitExpandedSubobject(QualType Type, Subobject Subobj) {
// C++2a [class.compare.default]p2 [P2002R0]:
// A defaulted <=> or == operator function for class C is defined as
// deleted if any non-static data member of C is of reference type
if (Type->isReferenceType()) {
if (Diagnose == ExplainDeleted) {
S.Diag(Subobj.Loc, diag::note_defaulted_comparison_reference_member)
<< FD << RD;
}
return Result::deleted();
}
// [...] Let xi be an lvalue denoting the ith element [...]
OpaqueValueExpr Xi(FD->getLocation(), Type, VK_LValue);
Expr *Args[] = {&Xi, &Xi};
// All operators start by trying to apply that same operator recursively.
OverloadedOperatorKind OO = FD->getOverloadedOperator();
assert(OO != OO_None && "not an overloaded operator!");
return visitBinaryOperator(OO, Args, Subobj);
}
Result
visitBinaryOperator(OverloadedOperatorKind OO, ArrayRef<Expr *> Args,
Subobject Subobj,
OverloadCandidateSet *SpaceshipCandidates = nullptr) {
// Note that there is no need to consider rewritten candidates here if
// we've already found there is no viable 'operator<=>' candidate (and are
// considering synthesizing a '<=>' from '==' and '<').
OverloadCandidateSet CandidateSet(
FD->getLocation(), OverloadCandidateSet::CSK_Operator,
OverloadCandidateSet::OperatorRewriteInfo(
OO, /*AllowRewrittenCandidates=*/!SpaceshipCandidates));
/// C++2a [class.compare.default]p1 [P2002R0]:
/// [...] the defaulted function itself is never a candidate for overload
/// resolution [...]
CandidateSet.exclude(FD);
if (Args[0]->getType()->isOverloadableType())
S.LookupOverloadedBinOp(CandidateSet, OO, Fns, Args);
else
// FIXME: We determine whether this is a valid expression by checking to
// see if there's a viable builtin operator candidate for it. That isn't
// really what the rules ask us to do, but should give the right results.
S.AddBuiltinOperatorCandidates(OO, FD->getLocation(), Args, CandidateSet);
Result R;
OverloadCandidateSet::iterator Best;
switch (CandidateSet.BestViableFunction(S, FD->getLocation(), Best)) {
case OR_Success: {
// C++2a [class.compare.secondary]p2 [P2002R0]:
// The operator function [...] is defined as deleted if [...] the
// candidate selected by overload resolution is not a rewritten
// candidate.
if ((DCK == DefaultedComparisonKind::NotEqual ||
DCK == DefaultedComparisonKind::Relational) &&
!Best->RewriteKind) {
if (Diagnose == ExplainDeleted) {
if (Best->Function) {
S.Diag(Best->Function->getLocation(),
diag::note_defaulted_comparison_not_rewritten_callee)
<< FD;
} else {
assert(Best->Conversions.size() == 2 &&
Best->Conversions[0].isUserDefined() &&
"non-user-defined conversion from class to built-in "
"comparison");
S.Diag(Best->Conversions[0]
.UserDefined.FoundConversionFunction.getDecl()
->getLocation(),
diag::note_defaulted_comparison_not_rewritten_conversion)
<< FD;
}
}
return Result::deleted();
}
// Throughout C++2a [class.compare]: if overload resolution does not
// result in a usable function, the candidate function is defined as
// deleted. This requires that we selected an accessible function.
//
// Note that this only considers the access of the function when named
// within the type of the subobject, and not the access path for any
// derived-to-base conversion.
CXXRecordDecl *ArgClass = Args[0]->getType()->getAsCXXRecordDecl();
if (ArgClass && Best->FoundDecl.getDecl() &&
Best->FoundDecl.getDecl()->isCXXClassMember()) {
QualType ObjectType = Subobj.Kind == Subobject::Member
? Args[0]->getType()
: S.Context.getRecordType(RD);
if (!S.isMemberAccessibleForDeletion(
ArgClass, Best->FoundDecl, ObjectType, Subobj.Loc,
Diagnose == ExplainDeleted
? S.PDiag(diag::note_defaulted_comparison_inaccessible)
<< FD << Subobj.Kind << Subobj.Decl
: S.PDiag()))
return Result::deleted();
}
bool NeedsDeducing =
OO == OO_Spaceship && FD->getReturnType()->isUndeducedAutoType();
if (FunctionDecl *BestFD = Best->Function) {
// C++2a [class.compare.default]p3 [P2002R0]:
// A defaulted comparison function is constexpr-compatible if
// [...] no overlod resolution performed [...] results in a
// non-constexpr function.
assert(!BestFD->isDeleted() && "wrong overload resolution result");
// If it's not constexpr, explain why not.
if (Diagnose == ExplainConstexpr && !BestFD->isConstexpr()) {
if (Subobj.Kind != Subobject::CompleteObject)
S.Diag(Subobj.Loc, diag::note_defaulted_comparison_not_constexpr)
<< Subobj.Kind << Subobj.Decl;
S.Diag(BestFD->getLocation(),
diag::note_defaulted_comparison_not_constexpr_here);
// Bail out after explaining; we don't want any more notes.
return Result::deleted();
}
R.Constexpr &= BestFD->isConstexpr();
if (NeedsDeducing) {
// If any callee has an undeduced return type, deduce it now.
// FIXME: It's not clear how a failure here should be handled. For
// now, we produce an eager diagnostic, because that is forward
// compatible with most (all?) other reasonable options.
if (BestFD->getReturnType()->isUndeducedType() &&
S.DeduceReturnType(BestFD, FD->getLocation(),
/*Diagnose=*/false)) {
// Don't produce a duplicate error when asked to explain why the
// comparison is deleted: we diagnosed that when initially checking
// the defaulted operator.
if (Diagnose == NoDiagnostics) {
S.Diag(
FD->getLocation(),
diag::err_defaulted_comparison_cannot_deduce_undeduced_auto)
<< Subobj.Kind << Subobj.Decl;
S.Diag(
Subobj.Loc,
diag::note_defaulted_comparison_cannot_deduce_undeduced_auto)
<< Subobj.Kind << Subobj.Decl;
S.Diag(BestFD->getLocation(),
diag::note_defaulted_comparison_cannot_deduce_callee)
<< Subobj.Kind << Subobj.Decl;
}
return Result::deleted();
}
auto *Info = S.Context.CompCategories.lookupInfoForType(
BestFD->getCallResultType());
if (!Info) {
if (Diagnose == ExplainDeleted) {
S.Diag(Subobj.Loc, diag::note_defaulted_comparison_cannot_deduce)
<< Subobj.Kind << Subobj.Decl
<< BestFD->getCallResultType().withoutLocalFastQualifiers();
S.Diag(BestFD->getLocation(),
diag::note_defaulted_comparison_cannot_deduce_callee)
<< Subobj.Kind << Subobj.Decl;
}
return Result::deleted();
}
R.Category = Info->Kind;
}
} else {
QualType T = Best->BuiltinParamTypes[0];
assert(T == Best->BuiltinParamTypes[1] &&
"builtin comparison for different types?");
assert(Best->BuiltinParamTypes[2].isNull() &&
"invalid builtin comparison");
if (NeedsDeducing) {
Optional<ComparisonCategoryType> Cat =
getComparisonCategoryForBuiltinCmp(T);
assert(Cat && "no category for builtin comparison?");
R.Category = *Cat;
}
}
// Note that we might be rewriting to a different operator. That call is
// not considered until we come to actually build the comparison function.
break;
}
case OR_Ambiguous:
if (Diagnose == ExplainDeleted) {
unsigned Kind = 0;
if (FD->getOverloadedOperator() == OO_Spaceship && OO != OO_Spaceship)
Kind = OO == OO_EqualEqual ? 1 : 2;
CandidateSet.NoteCandidates(
PartialDiagnosticAt(
Subobj.Loc, S.PDiag(diag::note_defaulted_comparison_ambiguous)
<< FD << Kind << Subobj.Kind << Subobj.Decl),
S, OCD_AmbiguousCandidates, Args);
}
R = Result::deleted();
break;
case OR_Deleted:
if (Diagnose == ExplainDeleted) {
if ((DCK == DefaultedComparisonKind::NotEqual ||
DCK == DefaultedComparisonKind::Relational) &&
!Best->RewriteKind) {
S.Diag(Best->Function->getLocation(),
diag::note_defaulted_comparison_not_rewritten_callee)
<< FD;
} else {
S.Diag(Subobj.Loc,
diag::note_defaulted_comparison_calls_deleted)
<< FD << Subobj.Kind << Subobj.Decl;
S.NoteDeletedFunction(Best->Function);
}
}
R = Result::deleted();
break;
case OR_No_Viable_Function:
// If there's no usable candidate, we're done unless we can rewrite a
// '<=>' in terms of '==' and '<'.
if (OO == OO_Spaceship &&
S.Context.CompCategories.lookupInfoForType(FD->getReturnType())) {
// For any kind of comparison category return type, we need a usable
// '==' and a usable '<'.
if (!R.add(visitBinaryOperator(OO_EqualEqual, Args, Subobj,
&CandidateSet)))
R.add(visitBinaryOperator(OO_Less, Args, Subobj, &CandidateSet));
break;
}
if (Diagnose == ExplainDeleted) {
S.Diag(Subobj.Loc, diag::note_defaulted_comparison_no_viable_function)
<< FD << (OO == OO_ExclaimEqual) << Subobj.Kind << Subobj.Decl;
// For a three-way comparison, list both the candidates for the
// original operator and the candidates for the synthesized operator.
if (SpaceshipCandidates) {
SpaceshipCandidates->NoteCandidates(
S, Args,
SpaceshipCandidates->CompleteCandidates(S, OCD_AllCandidates,
Args, FD->getLocation()));
S.Diag(Subobj.Loc,
diag::note_defaulted_comparison_no_viable_function_synthesized)
<< (OO == OO_EqualEqual ? 0 : 1);
}
CandidateSet.NoteCandidates(
S, Args,
CandidateSet.CompleteCandidates(S, OCD_AllCandidates, Args,
FD->getLocation()));
}
R = Result::deleted();
break;
}
return R;
}
};
/// A list of statements.
struct StmtListResult {
bool IsInvalid = false;
llvm::SmallVector<Stmt*, 16> Stmts;
bool add(const StmtResult &S) {
IsInvalid |= S.isInvalid();
if (IsInvalid)
return true;
Stmts.push_back(S.get());
return false;
}
};
/// A visitor over the notional body of a defaulted comparison that synthesizes
/// the actual body.
class DefaultedComparisonSynthesizer
: public DefaultedComparisonVisitor<DefaultedComparisonSynthesizer,
StmtListResult, StmtResult,
std::pair<ExprResult, ExprResult>> {
SourceLocation Loc;
unsigned ArrayDepth = 0;
public:
using Base = DefaultedComparisonVisitor;
using ExprPair = std::pair<ExprResult, ExprResult>;
friend Base;
DefaultedComparisonSynthesizer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
DefaultedComparisonKind DCK,
SourceLocation BodyLoc)
: Base(S, RD, FD, DCK), Loc(BodyLoc) {}
/// Build a suitable function body for this defaulted comparison operator.
StmtResult build() {
Sema::CompoundScopeRAII CompoundScope(S);
StmtListResult Stmts = visit();
if (Stmts.IsInvalid)
return StmtError();
ExprResult RetVal;
switch (DCK) {
case DefaultedComparisonKind::None:
llvm_unreachable("not a defaulted comparison");
case DefaultedComparisonKind::Equal: {
// C++2a [class.eq]p3:
// [...] compar[e] the corresponding elements [...] until the first
// index i where xi == yi yields [...] false. If no such index exists,
// V is true. Otherwise, V is false.
//
// Join the comparisons with '&&'s and return the result. Use a right
// fold (traversing the conditions right-to-left), because that
// short-circuits more naturally.
auto OldStmts = std::move(Stmts.Stmts);
Stmts.Stmts.clear();
ExprResult CmpSoFar;
// Finish a particular comparison chain.
auto FinishCmp = [&] {
if (Expr *Prior = CmpSoFar.get()) {
// Convert the last expression to 'return ...;'
if (RetVal.isUnset() && Stmts.Stmts.empty())
RetVal = CmpSoFar;
// Convert any prior comparison to 'if (!(...)) return false;'
else if (Stmts.add(buildIfNotCondReturnFalse(Prior)))
return true;
CmpSoFar = ExprResult();
}
return false;
};
for (Stmt *EAsStmt : llvm::reverse(OldStmts)) {
Expr *E = dyn_cast<Expr>(EAsStmt);
if (!E) {
// Found an array comparison.
if (FinishCmp() || Stmts.add(EAsStmt))
return StmtError();
continue;
}
if (CmpSoFar.isUnset()) {
CmpSoFar = E;
continue;
}
CmpSoFar = S.CreateBuiltinBinOp(Loc, BO_LAnd, E, CmpSoFar.get());
if (CmpSoFar.isInvalid())
return StmtError();
}
if (FinishCmp())
return StmtError();
std::reverse(Stmts.Stmts.begin(), Stmts.Stmts.end());
// If no such index exists, V is true.
if (RetVal.isUnset())
RetVal = S.ActOnCXXBoolLiteral(Loc, tok::kw_true);
break;
}
case DefaultedComparisonKind::ThreeWay: {
// Per C++2a [class.spaceship]p3, as a fallback add:
// return static_cast<R>(std::strong_ordering::equal);
QualType StrongOrdering = S.CheckComparisonCategoryType(
ComparisonCategoryType::StrongOrdering, Loc,
Sema::ComparisonCategoryUsage::DefaultedOperator);
if (StrongOrdering.isNull())
return StmtError();
VarDecl *EqualVD = S.Context.CompCategories.getInfoForType(StrongOrdering)
.getValueInfo(ComparisonCategoryResult::Equal)
->VD;
RetVal = getDecl(EqualVD);
if (RetVal.isInvalid())
return StmtError();
RetVal = buildStaticCastToR(RetVal.get());
break;
}
case DefaultedComparisonKind::NotEqual:
case DefaultedComparisonKind::Relational:
RetVal = cast<Expr>(Stmts.Stmts.pop_back_val());
break;
}
// Build the final return statement.
if (RetVal.isInvalid())
return StmtError();
StmtResult ReturnStmt = S.BuildReturnStmt(Loc, RetVal.get());
if (ReturnStmt.isInvalid())
return StmtError();
Stmts.Stmts.push_back(ReturnStmt.get());
return S.ActOnCompoundStmt(Loc, Loc, Stmts.Stmts, /*IsStmtExpr=*/false);
}
private:
ExprResult getDecl(ValueDecl *VD) {
return S.BuildDeclarationNameExpr(
CXXScopeSpec(), DeclarationNameInfo(VD->getDeclName(), Loc), VD);
}
ExprResult getParam(unsigned I) {
ParmVarDecl *PD = FD->getParamDecl(I);
return getDecl(PD);
}
ExprPair getCompleteObject() {
unsigned Param = 0;
ExprResult LHS;
if (isa<CXXMethodDecl>(FD)) {
// LHS is '*this'.
LHS = S.ActOnCXXThis(Loc);
if (!LHS.isInvalid())
LHS = S.CreateBuiltinUnaryOp(Loc, UO_Deref, LHS.get());
} else {
LHS = getParam(Param++);
}
ExprResult RHS = getParam(Param++);
assert(Param == FD->getNumParams());
return {LHS, RHS};
}
ExprPair getBase(CXXBaseSpecifier *Base) {
ExprPair Obj = getCompleteObject();
if (Obj.first.isInvalid() || Obj.second.isInvalid())
return {ExprError(), ExprError()};
CXXCastPath Path = {Base};
return {S.ImpCastExprToType(Obj.first.get(), Base->getType(),
CK_DerivedToBase, VK_LValue, &Path),
S.ImpCastExprToType(Obj.second.get(), Base->getType(),
CK_DerivedToBase, VK_LValue, &Path)};
}
ExprPair getField(FieldDecl *Field) {
ExprPair Obj = getCompleteObject();
if (Obj.first.isInvalid() || Obj.second.isInvalid())
return {ExprError(), ExprError()};
DeclAccessPair Found = DeclAccessPair::make(Field, Field->getAccess());
DeclarationNameInfo NameInfo(Field->getDeclName(), Loc);
return {S.BuildFieldReferenceExpr(Obj.first.get(), /*IsArrow=*/false, Loc,
CXXScopeSpec(), Field, Found, NameInfo),
S.BuildFieldReferenceExpr(Obj.second.get(), /*IsArrow=*/false, Loc,
CXXScopeSpec(), Field, Found, NameInfo)};
}
// FIXME: When expanding a subobject, register a note in the code synthesis
// stack to say which subobject we're comparing.
StmtResult buildIfNotCondReturnFalse(ExprResult Cond) {
if (Cond.isInvalid())
return StmtError();
ExprResult NotCond = S.CreateBuiltinUnaryOp(Loc, UO_LNot, Cond.get());
if (NotCond.isInvalid())
return StmtError();
ExprResult False = S.ActOnCXXBoolLiteral(Loc, tok::kw_false);
assert(!False.isInvalid() && "should never fail");
StmtResult ReturnFalse = S.BuildReturnStmt(Loc, False.get());
if (ReturnFalse.isInvalid())
return StmtError();
return S.ActOnIfStmt(Loc, IfStatementKind::Ordinary, Loc, nullptr,
S.ActOnCondition(nullptr, Loc, NotCond.get(),
Sema::ConditionKind::Boolean),
Loc, ReturnFalse.get(), SourceLocation(), nullptr);
}
StmtResult visitSubobjectArray(QualType Type, llvm::APInt Size,
ExprPair Subobj) {
QualType SizeType = S.Context.getSizeType();
Size = Size.zextOrTrunc(S.Context.getTypeSize(SizeType));
// Build 'size_t i$n = 0'.
IdentifierInfo *IterationVarName = nullptr;
{
SmallString<8> Str;
llvm::raw_svector_ostream OS(Str);
OS << "i" << ArrayDepth;
IterationVarName = &S.Context.Idents.get(OS.str());
}
VarDecl *IterationVar = VarDecl::Create(
S.Context, S.CurContext, Loc, Loc, IterationVarName, SizeType,
S.Context.getTrivialTypeSourceInfo(SizeType, Loc), SC_None);
llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
IterationVar->setInit(
IntegerLiteral::Create(S.Context, Zero, SizeType, Loc));
Stmt *Init = new (S.Context) DeclStmt(DeclGroupRef(IterationVar), Loc, Loc);
auto IterRef = [&] {
ExprResult Ref = S.BuildDeclarationNameExpr(
CXXScopeSpec(), DeclarationNameInfo(IterationVarName, Loc),
IterationVar);
assert(!Ref.isInvalid() && "can't reference our own variable?");
return Ref.get();
};
// Build 'i$n != Size'.
ExprResult Cond = S.CreateBuiltinBinOp(
Loc, BO_NE, IterRef(),
IntegerLiteral::Create(S.Context, Size, SizeType, Loc));
assert(!Cond.isInvalid() && "should never fail");
// Build '++i$n'.
ExprResult Inc = S.CreateBuiltinUnaryOp(Loc, UO_PreInc, IterRef());
assert(!Inc.isInvalid() && "should never fail");
// Build 'a[i$n]' and 'b[i$n]'.
auto Index = [&](ExprResult E) {
if (E.isInvalid())
return ExprError();
return S.CreateBuiltinArraySubscriptExpr(E.get(), Loc, IterRef(), Loc);
};
Subobj.first = Index(Subobj.first);
Subobj.second = Index(Subobj.second);
// Compare the array elements.
++ArrayDepth;
StmtResult Substmt = visitSubobject(Type, Subobj);
--ArrayDepth;
if (Substmt.isInvalid())
return StmtError();
// For the inner level of an 'operator==', build 'if (!cmp) return false;'.
// For outer levels or for an 'operator<=>' we already have a suitable
// statement that returns as necessary.
if (Expr *ElemCmp = dyn_cast<Expr>(Substmt.get())) {
assert(DCK == DefaultedComparisonKind::Equal &&
"should have non-expression statement");
Substmt = buildIfNotCondReturnFalse(ElemCmp);
if (Substmt.isInvalid())
return StmtError();
}
// Build 'for (...) ...'
return S.ActOnForStmt(Loc, Loc, Init,
S.ActOnCondition(nullptr, Loc, Cond.get(),
Sema::ConditionKind::Boolean),
S.MakeFullDiscardedValueExpr(Inc.get()), Loc,
Substmt.get());
}
StmtResult visitExpandedSubobject(QualType Type, ExprPair Obj) {
if (Obj.first.isInvalid() || Obj.second.isInvalid())
return StmtError();
OverloadedOperatorKind OO = FD->getOverloadedOperator();
BinaryOperatorKind Opc = BinaryOperator::getOverloadedOpcode(OO);
ExprResult Op;
if (Type->isOverloadableType())
Op = S.CreateOverloadedBinOp(Loc, Opc, Fns, Obj.first.get(),
Obj.second.get(), /*PerformADL=*/true,
/*AllowRewrittenCandidates=*/true, FD);
else
Op = S.CreateBuiltinBinOp(Loc, Opc, Obj.first.get(), Obj.second.get());
if (Op.isInvalid())
return StmtError();
switch (DCK) {
case DefaultedComparisonKind::None:
llvm_unreachable("not a defaulted comparison");
case DefaultedComparisonKind::Equal:
// Per C++2a [class.eq]p2, each comparison is individually contextually
// converted to bool.
Op = S.PerformContextuallyConvertToBool(Op.get());
if (Op.isInvalid())
return StmtError();
return Op.get();
case DefaultedComparisonKind::ThreeWay: {
// Per C++2a [class.spaceship]p3, form:
// if (R cmp = static_cast<R>(op); cmp != 0)
// return cmp;
QualType R = FD->getReturnType();
Op = buildStaticCastToR(Op.get());
if (Op.isInvalid())
return StmtError();
// R cmp = ...;
IdentifierInfo *Name = &S.Context.Idents.get("cmp");
VarDecl *VD =
VarDecl::Create(S.Context, S.CurContext, Loc, Loc, Name, R,
S.Context.getTrivialTypeSourceInfo(R, Loc), SC_None);
S.AddInitializerToDecl(VD, Op.get(), /*DirectInit=*/false);
Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(VD), Loc, Loc);
// cmp != 0
ExprResult VDRef = getDecl(VD);
if (VDRef.isInvalid())
return StmtError();
llvm::APInt ZeroVal(S.Context.getIntWidth(S.Context.IntTy), 0);
Expr *Zero =
IntegerLiteral::Create(S.Context, ZeroVal, S.Context.IntTy, Loc);
ExprResult Comp;
if (VDRef.get()->getType()->isOverloadableType())
Comp = S.CreateOverloadedBinOp(Loc, BO_NE, Fns, VDRef.get(), Zero, true,
true, FD);
else
Comp = S.CreateBuiltinBinOp(Loc, BO_NE, VDRef.get(), Zero);
if (Comp.isInvalid())
return StmtError();
Sema::ConditionResult Cond = S.ActOnCondition(
nullptr, Loc, Comp.get(), Sema::ConditionKind::Boolean);
if (Cond.isInvalid())
return StmtError();
// return cmp;
VDRef = getDecl(VD);
if (VDRef.isInvalid())
return StmtError();
StmtResult ReturnStmt = S.BuildReturnStmt(Loc, VDRef.get());
if (ReturnStmt.isInvalid())
return StmtError();
// if (...)
return S.ActOnIfStmt(Loc, IfStatementKind::Ordinary, Loc, InitStmt, Cond,
Loc, ReturnStmt.get(),
/*ElseLoc=*/SourceLocation(), /*Else=*/nullptr);
}
case DefaultedComparisonKind::NotEqual:
case DefaultedComparisonKind::Relational:
// C++2a [class.compare.secondary]p2:
// Otherwise, the operator function yields x @ y.
return Op.get();
}
llvm_unreachable("");
}
/// Build "static_cast<R>(E)".
ExprResult buildStaticCastToR(Expr *E) {
QualType R = FD->getReturnType();
assert(!R->isUndeducedType() && "type should have been deduced already");
// Don't bother forming a no-op cast in the common case.
if (E->isPRValue() && S.Context.hasSameType(E->getType(), R))
return E;
return S.BuildCXXNamedCast(Loc, tok::kw_static_cast,
S.Context.getTrivialTypeSourceInfo(R, Loc), E,
SourceRange(Loc, Loc), SourceRange(Loc, Loc));
}
};
}
/// Perform the unqualified lookups that might be needed to form a defaulted
/// comparison function for the given operator.
static void lookupOperatorsForDefaultedComparison(Sema &Self, Scope *S,
UnresolvedSetImpl &Operators,
OverloadedOperatorKind Op) {
auto Lookup = [&](OverloadedOperatorKind OO) {
Self.LookupOverloadedOperatorName(OO, S, Operators);
};
// Every defaulted operator looks up itself.
Lookup(Op);
// ... and the rewritten form of itself, if any.
if (OverloadedOperatorKind ExtraOp = getRewrittenOverloadedOperator(Op))
Lookup(ExtraOp);
// For 'operator<=>', we also form a 'cmp != 0' expression, and might
// synthesize a three-way comparison from '<' and '=='. In a dependent
// context, we also need to look up '==' in case we implicitly declare a
// defaulted 'operator=='.
if (Op == OO_Spaceship) {
Lookup(OO_ExclaimEqual);
Lookup(OO_Less);
Lookup(OO_EqualEqual);
}
}
bool Sema::CheckExplicitlyDefaultedComparison(Scope *S, FunctionDecl *FD,
DefaultedComparisonKind DCK) {
assert(DCK != DefaultedComparisonKind::None && "not a defaulted comparison");
CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(FD->getLexicalDeclContext());
assert(RD && "defaulted comparison is not defaulted in a class");
// Perform any unqualified lookups we're going to need to default this
// function.
if (S) {
UnresolvedSet<32> Operators;
lookupOperatorsForDefaultedComparison(*this, S, Operators,
FD->getOverloadedOperator());
FD->setDefaultedFunctionInfo(FunctionDecl::DefaultedFunctionInfo::Create(
Context, Operators.pairs()));
}
// C++2a [class.compare.default]p1:
// A defaulted comparison operator function for some class C shall be a
// non-template function declared in the member-specification of C that is
// -- a non-static const member of C having one parameter of type
// const C&, or
// -- a friend of C having two parameters of type const C& or two
// parameters of type C.
QualType ExpectedParmType1 = Context.getRecordType(RD);
QualType ExpectedParmType2 =
Context.getLValueReferenceType(ExpectedParmType1.withConst());
if (isa<CXXMethodDecl>(FD))
ExpectedParmType1 = ExpectedParmType2;
for (const ParmVarDecl *Param : FD->parameters()) {
if (!Param->getType()->isDependentType() &&
!Context.hasSameType(Param->getType(), ExpectedParmType1) &&
!Context.hasSameType(Param->getType(), ExpectedParmType2)) {
// Don't diagnose an implicit 'operator=='; we will have diagnosed the
// corresponding defaulted 'operator<=>' already.
if (!FD->isImplicit()) {
Diag(FD->getLocation(), diag::err_defaulted_comparison_param)
<< (int)DCK << Param->getType() << ExpectedParmType1
<< !isa<CXXMethodDecl>(FD)
<< ExpectedParmType2 << Param->getSourceRange();
}
return true;
}
}
if (FD->getNumParams() == 2 &&
!Context.hasSameType(FD->getParamDecl(0)->getType(),
FD->getParamDecl(1)->getType())) {
if (!FD->isImplicit()) {
Diag(FD->getLocation(), diag::err_defaulted_comparison_param_mismatch)
<< (int)DCK
<< FD->getParamDecl(0)->getType()
<< FD->getParamDecl(0)->getSourceRange()
<< FD->getParamDecl(1)->getType()
<< FD->getParamDecl(1)->getSourceRange();
}
return true;
}
// ... non-static const member ...
if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
assert(!MD->isStatic() && "comparison function cannot be a static member");
if (!MD->isConst()) {
SourceLocation InsertLoc;
if (FunctionTypeLoc Loc = MD->getFunctionTypeLoc())
InsertLoc = getLocForEndOfToken(Loc.getRParenLoc());
// Don't diagnose an implicit 'operator=='; we will have diagnosed the
// corresponding defaulted 'operator<=>' already.
if (!MD->isImplicit()) {
Diag(MD->getLocation(), diag::err_defaulted_comparison_non_const)
<< (int)DCK << FixItHint::CreateInsertion(InsertLoc, " const");
}
// Add the 'const' to the type to recover.
const auto *FPT = MD->getType()->castAs<FunctionProtoType>();
FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
EPI.TypeQuals.addConst();
MD->setType(Context.getFunctionType(FPT->getReturnType(),
FPT->getParamTypes(), EPI));
}
} else {
// A non-member function declared in a class must be a friend.
assert(FD->getFriendObjectKind() && "expected a friend declaration");
}
// C++2a [class.eq]p1, [class.rel]p1:
// A [defaulted comparison other than <=>] shall have a declared return
// type bool.
if (DCK != DefaultedComparisonKind::ThreeWay &&
!FD->getDeclaredReturnType()->isDependentType() &&
!Context.hasSameType(FD->getDeclaredReturnType(), Context.BoolTy)) {
Diag(FD->getLocation(), diag::err_defaulted_comparison_return_type_not_bool)
<< (int)DCK << FD->getDeclaredReturnType() << Context.BoolTy
<< FD->getReturnTypeSourceRange();
return true;
}
// C++2a [class.spaceship]p2 [P2002R0]:
// Let R be the declared return type [...]. If R is auto, [...]. Otherwise,
// R shall not contain a placeholder type.
if (DCK == DefaultedComparisonKind::ThreeWay &&
FD->getDeclaredReturnType()->getContainedDeducedType() &&
!Context.hasSameType(FD->getDeclaredReturnType(),
Context.getAutoDeductType())) {
Diag(FD->getLocation(),
diag::err_defaulted_comparison_deduced_return_type_not_auto)
<< (int)DCK << FD->getDeclaredReturnType() << Context.AutoDeductTy
<< FD->getReturnTypeSourceRange();
return true;
}
// For a defaulted function in a dependent class, defer all remaining checks
// until instantiation.
if (RD->isDependentType())
return false;
// Determine whether the function should be defined as deleted.
DefaultedComparisonInfo Info =
DefaultedComparisonAnalyzer(*this, RD, FD, DCK).visit();
bool First = FD == FD->getCanonicalDecl();
// If we want to delete the function, then do so; there's nothing else to
// check in that case.
if (Info.Deleted) {
if (!First) {
// C++11 [dcl.fct.def.default]p4:
// [For a] user-provided explicitly-defaulted function [...] if such a
// function is implicitly defined as deleted, the program is ill-formed.
//
// This is really just a consequence of the general rule that you can
// only delete a function on its first declaration.
Diag(FD->getLocation(), diag::err_non_first_default_compare_deletes)
<< FD->isImplicit() << (int)DCK;
DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
DefaultedComparisonAnalyzer::ExplainDeleted)
.visit();
return true;
}
SetDeclDeleted(FD, FD->getLocation());
if (!inTemplateInstantiation() && !FD->isImplicit()) {
Diag(FD->getLocation(), diag::warn_defaulted_comparison_deleted)
<< (int)DCK;
DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
DefaultedComparisonAnalyzer::ExplainDeleted)
.visit();
}
return false;
}
// C++2a [class.spaceship]p2:
// The return type is deduced as the common comparison type of R0, R1, ...
if (DCK == DefaultedComparisonKind::ThreeWay &&
FD->getDeclaredReturnType()->isUndeducedAutoType()) {
SourceLocation RetLoc = FD->getReturnTypeSourceRange().getBegin();
if (RetLoc.isInvalid())
RetLoc = FD->getBeginLoc();
// FIXME: Should we really care whether we have the complete type and the
// 'enumerator' constants here? A forward declaration seems sufficient.
QualType Cat = CheckComparisonCategoryType(
Info.Category, RetLoc, ComparisonCategoryUsage::DefaultedOperator);
if (Cat.isNull())
return true;
Context.adjustDeducedFunctionResultType(
FD, SubstAutoType(FD->getDeclaredReturnType(), Cat));
}
// C++2a [dcl.fct.def.default]p3 [P2002R0]:
// An explicitly-defaulted function that is not defined as deleted may be
// declared constexpr or consteval only if it is constexpr-compatible.
// C++2a [class.compare.default]p3 [P2002R0]:
// A defaulted comparison function is constexpr-compatible if it satisfies
// the requirements for a constexpr function [...]
// The only relevant requirements are that the parameter and return types are
// literal types. The remaining conditions are checked by the analyzer.
if (FD->isConstexpr()) {
if (CheckConstexprReturnType(*this, FD, CheckConstexprKind::Diagnose) &&
CheckConstexprParameterTypes(*this, FD, CheckConstexprKind::Diagnose) &&
!Info.Constexpr) {
Diag(FD->getBeginLoc(),
diag::err_incorrect_defaulted_comparison_constexpr)
<< FD->isImplicit() << (int)DCK << FD->isConsteval();
DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
DefaultedComparisonAnalyzer::ExplainConstexpr)
.visit();
}
}
// C++2a [dcl.fct.def.default]p3 [P2002R0]:
// If a constexpr-compatible function is explicitly defaulted on its first
// declaration, it is implicitly considered to be constexpr.
// FIXME: Only applying this to the first declaration seems problematic, as
// simple reorderings can affect the meaning of the program.
if (First && !FD->isConstexpr() && Info.Constexpr)
FD->setConstexprKind(ConstexprSpecKind::Constexpr);
// C++2a [except.spec]p3:
// If a declaration of a function does not have a noexcept-specifier
// [and] is defaulted on its first declaration, [...] the exception
// specification is as specified below
if (FD->getExceptionSpecType() == EST_None) {
auto *FPT = FD->getType()->castAs<FunctionProtoType>();
FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
EPI.ExceptionSpec.Type = EST_Unevaluated;
EPI.ExceptionSpec.SourceDecl = FD;
FD->setType(Context.getFunctionType(FPT->getReturnType(),
FPT->getParamTypes(), EPI));
}
return false;
}
void Sema::DeclareImplicitEqualityComparison(CXXRecordDecl *RD,
FunctionDecl *Spaceship) {
Sema::CodeSynthesisContext Ctx;
Ctx.Kind = Sema::CodeSynthesisContext::DeclaringImplicitEqualityComparison;
Ctx.PointOfInstantiation = Spaceship->getEndLoc();
Ctx.Entity = Spaceship;
pushCodeSynthesisContext(Ctx);
if (FunctionDecl *EqualEqual = SubstSpaceshipAsEqualEqual(RD, Spaceship))
EqualEqual->setImplicit();
popCodeSynthesisContext();
}
void Sema::DefineDefaultedComparison(SourceLocation UseLoc, FunctionDecl *FD,
DefaultedComparisonKind DCK) {
assert(FD->isDefaulted() && !FD->isDeleted() &&
!FD->doesThisDeclarationHaveABody());
if (FD->willHaveBody() || FD->isInvalidDecl())
return;
SynthesizedFunctionScope Scope(*this, FD);
// Add a context note for diagnostics produced after this point.
Scope.addContextNote(UseLoc);
{
// Build and set up the function body.
CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getLexicalParent());
SourceLocation BodyLoc =
FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation();
StmtResult Body =
DefaultedComparisonSynthesizer(*this, RD, FD, DCK, BodyLoc).build();
if (Body.isInvalid()) {
FD->setInvalidDecl();
return;
}
FD->setBody(Body.get());
FD->markUsed(Context);
}
// The exception specification is needed because we are defining the
// function. Note that this will reuse the body we just built.
ResolveExceptionSpec(UseLoc, FD->getType()->castAs<FunctionProtoType>());
if (ASTMutationListener *L = getASTMutationListener())
L->CompletedImplicitDefinition(FD);
}
static Sema::ImplicitExceptionSpecification
ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc,
FunctionDecl *FD,
Sema::DefaultedComparisonKind DCK) {
ComputingExceptionSpec CES(S, FD, Loc);
Sema::ImplicitExceptionSpecification ExceptSpec(S);
if (FD->isInvalidDecl())
return ExceptSpec;
// The common case is that we just defined the comparison function. In that
// case, just look at whether the body can throw.
if (FD->hasBody()) {
ExceptSpec.CalledStmt(FD->getBody());
} else {
// Otherwise, build a body so we can check it. This should ideally only
// happen when we're not actually marking the function referenced. (This is
// only really important for efficiency: we don't want to build and throw
// away bodies for comparison functions more than we strictly need to.)
// Pretend to synthesize the function body in an unevaluated context.
// Note that we can't actually just go ahead and define the function here:
// we are not permitted to mark its callees as referenced.
Sema::SynthesizedFunctionScope Scope(S, FD);
EnterExpressionEvaluationContext Context(
S, Sema::ExpressionEvaluationContext::Unevaluated);
CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getLexicalParent());
SourceLocation BodyLoc =
FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation();
StmtResult Body =
DefaultedComparisonSynthesizer(S, RD, FD, DCK, BodyLoc).build();
if (!Body.isInvalid())
ExceptSpec.CalledStmt(Body.get());
// FIXME: Can we hold onto this body and just transform it to potentially
// evaluated when we're asked to define the function rather than rebuilding
// it? Either that, or we should only build the bits of the body that we
// need (the expressions, not the statements).
}
return ExceptSpec;
}
void Sema::CheckDelayedMemberExceptionSpecs() {
decltype(DelayedOverridingExceptionSpecChecks) Overriding;
decltype(DelayedEquivalentExceptionSpecChecks) Equivalent;
std::swap(Overriding, DelayedOverridingExceptionSpecChecks);
std::swap(Equivalent, DelayedEquivalentExceptionSpecChecks);
// Perform any deferred checking of exception specifications for virtual
// destructors.
for (auto &Check : Overriding)
CheckOverridingFunctionExceptionSpec(Check.first, Check.second);
// Perform any deferred checking of exception specifications for befriended
// special members.
for (auto &Check : Equivalent)
CheckEquivalentExceptionSpec(Check.second, Check.first);
}
namespace {
/// CRTP base class for visiting operations performed by a special member
/// function (or inherited constructor).
template<typename Derived>
struct SpecialMemberVisitor {
Sema &S;
CXXMethodDecl *MD;
Sema::CXXSpecialMember CSM;
Sema::InheritedConstructorInfo *ICI;
// Properties of the special member, computed for convenience.
bool IsConstructor = false, IsAssignment = false, ConstArg = false;
SpecialMemberVisitor(Sema &S, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
Sema::InheritedConstructorInfo *ICI)
: S(S), MD(MD), CSM(CSM), ICI(ICI) {
switch (CSM) {
case Sema::CXXDefaultConstructor:
case Sema::CXXCopyConstructor:
case Sema::CXXMoveConstructor:
IsConstructor = true;
break;
case Sema::CXXCopyAssignment:
case Sema::CXXMoveAssignment:
IsAssignment = true;
break;
case Sema::CXXDestructor:
break;
case Sema::CXXInvalid:
llvm_unreachable("invalid special member kind");
}
if (MD->getNumParams()) {
if (const ReferenceType *RT =
MD->getParamDecl(0)->getType()->getAs<ReferenceType>())
ConstArg = RT->getPointeeType().isConstQualified();
}
}
Derived &getDerived() { return static_cast<Derived&>(*this); }
/// Is this a "move" special member?
bool isMove() const {
return CSM == Sema::CXXMoveConstructor || CSM == Sema::CXXMoveAssignment;
}
/// Look up the corresponding special member in the given class.
Sema::SpecialMemberOverloadResult lookupIn(CXXRecordDecl *Class,
unsigned Quals, bool IsMutable) {
return lookupCallFromSpecialMember(S, Class, CSM, Quals,
ConstArg && !IsMutable);
}
/// Look up the constructor for the specified base class to see if it's
/// overridden due to this being an inherited constructor.
Sema::SpecialMemberOverloadResult lookupInheritedCtor(CXXRecordDecl *Class) {
if (!ICI)
return {};
assert(CSM == Sema::CXXDefaultConstructor);
auto *BaseCtor =
cast<CXXConstructorDecl>(MD)->getInheritedConstructor().getConstructor();
if (auto *MD = ICI->findConstructorForBase(Class, BaseCtor).first)
return MD;
return {};
}
/// A base or member subobject.
typedef llvm::PointerUnion<CXXBaseSpecifier*, FieldDecl*> Subobject;
/// Get the location to use for a subobject in diagnostics.
static SourceLocation getSubobjectLoc(Subobject Subobj) {
// FIXME: For an indirect virtual base, the direct base leading to
// the indirect virtual base would be a more useful choice.
if (auto *B = Subobj.dyn_cast<CXXBaseSpecifier*>())
return B->getBaseTypeLoc();
else
return Subobj.get<FieldDecl*>()->getLocation();
}
enum BasesToVisit {
/// Visit all non-virtual (direct) bases.
VisitNonVirtualBases,
/// Visit all direct bases, virtual or not.
VisitDirectBases,
/// Visit all non-virtual bases, and all virtual bases if the class
/// is not abstract.
VisitPotentiallyConstructedBases,
/// Visit all direct or virtual bases.
VisitAllBases
};
// Visit the bases and members of the class.
bool visit(BasesToVisit Bases) {
CXXRecordDecl *RD = MD->getParent();
if (Bases == VisitPotentiallyConstructedBases)
Bases = RD->isAbstract() ? VisitNonVirtualBases : VisitAllBases;
for (auto &B : RD->bases())
if ((Bases == VisitDirectBases || !B.isVirtual()) &&
getDerived().visitBase(&B))
return true;
if (Bases == VisitAllBases)
for (auto &B : RD->vbases())
if (getDerived().visitBase(&B))
return true;
for (auto *F : RD->fields())
if (!F->isInvalidDecl() && !F->isUnnamedBitfield() &&
getDerived().visitField(F))
return true;
return false;
}
};
}
namespace {
struct SpecialMemberDeletionInfo
: SpecialMemberVisitor<SpecialMemberDeletionInfo> {
bool Diagnose;
SourceLocation Loc;
bool AllFieldsAreConst;
SpecialMemberDeletionInfo(Sema &S, CXXMethodDecl *MD,
Sema::CXXSpecialMember CSM,
Sema::InheritedConstructorInfo *ICI, bool Diagnose)
: SpecialMemberVisitor(S, MD, CSM, ICI), Diagnose(Diagnose),
Loc(MD->getLocation()), AllFieldsAreConst(true) {}
bool inUnion() const { return MD->getParent()->isUnion(); }
Sema::CXXSpecialMember getEffectiveCSM() {
return ICI ? Sema::CXXInvalid : CSM;
}
bool shouldDeleteForVariantObjCPtrMember(FieldDecl *FD, QualType FieldType);
bool visitBase(CXXBaseSpecifier *Base) { return shouldDeleteForBase(Base); }
bool visitField(FieldDecl *Field) { return shouldDeleteForField(Field); }
bool shouldDeleteForBase(CXXBaseSpecifier *Base);
bool shouldDeleteForField(FieldDecl *FD);
bool shouldDeleteForAllConstMembers();
bool shouldDeleteForClassSubobject(CXXRecordDecl *Class, Subobject Subobj,
unsigned Quals);
bool shouldDeleteForSubobjectCall(Subobject Subobj,
Sema::SpecialMemberOverloadResult SMOR,
bool IsDtorCallInCtor);
bool isAccessible(Subobject Subobj, CXXMethodDecl *D);
};
}
/// Is the given special member inaccessible when used on the given
/// sub-object.
bool SpecialMemberDeletionInfo::isAccessible(Subobject Subobj,
CXXMethodDecl *target) {
/// If we're operating on a base class, the object type is the
/// type of this special member.
QualType objectTy;
AccessSpecifier access = target->getAccess();
if (CXXBaseSpecifier *base = Subobj.dyn_cast<CXXBaseSpecifier*>()) {
objectTy = S.Context.getTypeDeclType(MD->getParent());
access = CXXRecordDecl::MergeAccess(base->getAccessSpecifier(), access);
// If we're operating on a field, the object type is the type of the field.
} else {
objectTy = S.Context.getTypeDeclType(target->getParent());
}
return S.isMemberAccessibleForDeletion(
target->getParent(), DeclAccessPair::make(target, access), objectTy);
}
/// Check whether we should delete a special member due to the implicit
/// definition containing a call to a special member of a subobject.
bool SpecialMemberDeletionInfo::shouldDeleteForSubobjectCall(
Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR,
bool IsDtorCallInCtor) {
CXXMethodDecl *Decl = SMOR.getMethod();
FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
int DiagKind = -1;
if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::NoMemberOrDeleted)
DiagKind = !Decl ? 0 : 1;
else if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
DiagKind = 2;
else if (!isAccessible(Subobj, Decl))
DiagKind = 3;
else if (!IsDtorCallInCtor && Field && Field->getParent()->isUnion() &&
!Decl->isTrivial()) {
// A member of a union must have a trivial corresponding special member.
// As a weird special case, a destructor call from a union's constructor
// must be accessible and non-deleted, but need not be trivial. Such a
// destructor is never actually called, but is semantically checked as
// if it were.
DiagKind = 4;
}
if (DiagKind == -1)
return false;
if (Diagnose) {
if (Field) {
S.Diag(Field->getLocation(),
diag::note_deleted_special_member_class_subobject)
<< getEffectiveCSM() << MD->getParent() << /*IsField*/true
<< Field << DiagKind << IsDtorCallInCtor << /*IsObjCPtr*/false;
} else {
CXXBaseSpecifier *Base = Subobj.get<CXXBaseSpecifier*>();
S.Diag(Base->getBeginLoc(),
diag::note_deleted_special_member_class_subobject)
<< getEffectiveCSM() << MD->getParent() << /*IsField*/ false
<< Base->getType() << DiagKind << IsDtorCallInCtor
<< /*IsObjCPtr*/false;
}
if (DiagKind == 1)
S.NoteDeletedFunction(Decl);
// FIXME: Explain inaccessibility if DiagKind == 3.
}
return true;
}
/// Check whether we should delete a special member function due to having a
/// direct or virtual base class or non-static data member of class type M.
bool SpecialMemberDeletionInfo::shouldDeleteForClassSubobject(
CXXRecordDecl *Class, Subobject Subobj, unsigned Quals) {
FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
bool IsMutable = Field && Field->isMutable();
// C++11 [class.ctor]p5:
// -- any direct or virtual base class, or non-static data member with no
// brace-or-equal-initializer, has class type M (or array thereof) and
// either M has no default constructor or overload resolution as applied
// to M's default constructor results in an ambiguity or in a function
// that is deleted or inaccessible
// C++11 [class.copy]p11, C++11 [class.copy]p23:
// -- a direct or virtual base class B that cannot be copied/moved because
// overload resolution, as applied to B's corresponding special member,
// results in an ambiguity or a function that is deleted or inaccessible
// from the defaulted special member
// C++11 [class.dtor]p5:
// -- any direct or virtual base class [...] has a type with a destructor
// that is deleted or inaccessible
if (!(CSM == Sema::CXXDefaultConstructor &&
Field && Field->hasInClassInitializer()) &&
shouldDeleteForSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable),
false))
return true;
// C++11 [class.ctor]p5, C++11 [class.copy]p11:
// -- any direct or virtual base class or non-static data member has a
// type with a destructor that is deleted or inaccessible
if (IsConstructor) {
Sema::SpecialMemberOverloadResult SMOR =
S.LookupSpecialMember(Class, Sema::CXXDestructor,
false, false, false, false, false);
if (shouldDeleteForSubobjectCall(Subobj, SMOR, true))
return true;
}
return false;
}
bool SpecialMemberDeletionInfo::shouldDeleteForVariantObjCPtrMember(
FieldDecl *FD, QualType FieldType) {
// The defaulted special functions are defined as deleted if this is a variant
// member with a non-trivial ownership type, e.g., ObjC __strong or __weak
// type under ARC.
if (!FieldType.hasNonTrivialObjCLifetime())
return false;
// Don't make the defaulted default constructor defined as deleted if the
// member has an in-class initializer.
if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer())
return false;
if (Diagnose) {
auto *ParentClass = cast<CXXRecordDecl>(FD->getParent());
S.Diag(FD->getLocation(),
diag::note_deleted_special_member_class_subobject)
<< getEffectiveCSM() << ParentClass << /*IsField*/true
<< FD << 4 << /*IsDtorCallInCtor*/false << /*IsObjCPtr*/true;
}
return true;
}
/// Check whether we should delete a special member function due to the class
/// having a particular direct or virtual base class.
bool SpecialMemberDeletionInfo::shouldDeleteForBase(CXXBaseSpecifier *Base) {
CXXRecordDecl *BaseClass = Base->getType()->getAsCXXRecordDecl();
// If program is correct, BaseClass cannot be null, but if it is, the error
// must be reported elsewhere.
if (!BaseClass)
return false;
// If we have an inheriting constructor, check whether we're calling an
// inherited constructor instead of a default constructor.
Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass);
if (auto *BaseCtor = SMOR.getMethod()) {
// Note that we do not check access along this path; other than that,
// this is the same as shouldDeleteForSubobjectCall(Base, BaseCtor, false);
// FIXME: Check that the base has a usable destructor! Sink this into
// shouldDeleteForClassSubobject.
if (BaseCtor->isDeleted() && Diagnose) {
S.Diag(Base->getBeginLoc(),
diag::note_deleted_special_member_class_subobject)
<< getEffectiveCSM() << MD->getParent() << /*IsField*/ false
<< Base->getType() << /*Deleted*/ 1 << /*IsDtorCallInCtor*/ false
<< /*IsObjCPtr*/false;
S.NoteDeletedFunction(BaseCtor);
}
return BaseCtor->isDeleted();
}
return shouldDeleteForClassSubobject(BaseClass, Base, 0);
}
/// Check whether we should delete a special member function due to the class
/// having a particular non-static data member.
bool SpecialMemberDeletionInfo::shouldDeleteForField(FieldDecl *FD) {
QualType FieldType = S.Context.getBaseElementType(FD->getType());
CXXRecordDecl *FieldRecord = FieldType->getAsCXXRecordDecl();
if (inUnion() && shouldDeleteForVariantObjCPtrMember(FD, FieldType))
return true;
if (CSM == Sema::CXXDefaultConstructor) {
// For a default constructor, all references must be initialized in-class
// and, if a union, it must have a non-const member.
if (FieldType->isReferenceType() && !FD->hasInClassInitializer()) {
if (Diagnose)
S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
<< !!ICI << MD->getParent() << FD << FieldType << /*Reference*/0;
return true;
}
// C++11 [class.ctor]p5: any non-variant non-static data member of
// const-qualified type (or array thereof) with no
// brace-or-equal-initializer does not have a user-provided default
// constructor.
if (!inUnion() && FieldType.isConstQualified() &&
!FD->hasInClassInitializer() &&
(!FieldRecord || !FieldRecord->hasUserProvidedDefaultConstructor())) {
if (Diagnose)
S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
<< !!ICI << MD->getParent() << FD << FD->getType() << /*Const*/1;
return true;
}
if (inUnion() && !FieldType.isConstQualified())
AllFieldsAreConst = false;
} else if (CSM == Sema::CXXCopyConstructor) {
// For a copy constructor, data members must not be of rvalue reference
// type.
if (FieldType->isRValueReferenceType()) {
if (Diagnose)
S.Diag(FD->getLocation(), diag::note_deleted_copy_ctor_rvalue_reference)
<< MD->getParent() << FD << FieldType;
return true;
}
} else if (IsAssignment) {
// For an assignment operator, data members must not be of reference type.
if (FieldType->isReferenceType()) {
if (Diagnose)
S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
<< isMove() << MD->getParent() << FD << FieldType << /*Reference*/0;
return true;
}
if (!FieldRecord && FieldType.isConstQualified()) {
// C++11 [class.copy]p23:
// -- a non-static data member of const non-class type (or array thereof)
if (Diagnose)
S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
<< isMove() << MD->getParent() << FD << FD->getType() << /*Const*/1;
return true;
}
}
if (FieldRecord) {
// Some additional restrictions exist on the variant members.
if (!inUnion() && FieldRecord->isUnion() &&
FieldRecord->isAnonymousStructOrUnion()) {
bool AllVariantFieldsAreConst = true;
// FIXME: Handle anonymous unions declared within anonymous unions.
for (auto *UI : FieldRecord->fields()) {
QualType UnionFieldType = S.Context.getBaseElementType(UI->getType());
if (shouldDeleteForVariantObjCPtrMember(&*UI, UnionFieldType))
return true;
if (!UnionFieldType.isConstQualified())
AllVariantFieldsAreConst = false;
CXXRecordDecl *UnionFieldRecord = UnionFieldType->getAsCXXRecordDecl();
if (UnionFieldRecord &&
shouldDeleteForClassSubobject(UnionFieldRecord, UI,
UnionFieldType.getCVRQualifiers()))
return true;
}
// At least one member in each anonymous union must be non-const
if (CSM == Sema::CXXDefaultConstructor && AllVariantFieldsAreConst &&
!FieldRecord->field_empty()) {
if (Diagnose)
S.Diag(FieldRecord->getLocation(),
diag::note_deleted_default_ctor_all_const)
<< !!ICI << MD->getParent() << /*anonymous union*/1;
return true;
}
// Don't check the implicit member of the anonymous union type.
// This is technically non-conformant but supported, and we have a
// diagnostic for this elsewhere.
return false;
}
if (shouldDeleteForClassSubobject(FieldRecord, FD,
FieldType.getCVRQualifiers()))
return true;
}
return false;
}
/// C++11 [class.ctor] p5:
/// A defaulted default constructor for a class X is defined as deleted if
/// X is a union and all of its variant members are of const-qualified type.
bool SpecialMemberDeletionInfo::shouldDeleteForAllConstMembers() {
// This is a silly definition, because it gives an empty union a deleted
// default constructor. Don't do that.
if (CSM == Sema::CXXDefaultConstructor && inUnion() && AllFieldsAreConst) {
bool AnyFields = false;
for (auto *F : MD->getParent()->fields())
if ((AnyFields = !F->isUnnamedBitfield()))
break;
if (!AnyFields)
return false;
if (Diagnose)
S.Diag(MD->getParent()->getLocation(),
diag::note_deleted_default_ctor_all_const)
<< !!ICI << MD->getParent() << /*not anonymous union*/0;
return true;
}
return false;
}
/// Determine whether a defaulted special member function should be defined as
/// deleted, as specified in C++11 [class.ctor]p5, C++11 [class.copy]p11,
/// C++11 [class.copy]p23, and C++11 [class.dtor]p5.
bool Sema::ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM,
InheritedConstructorInfo *ICI,
bool Diagnose) {
if (MD->isInvalidDecl())
return false;
CXXRecordDecl *RD = MD->getParent();
assert(!RD->isDependentType() && "do deletion after instantiation");
if (!LangOpts.CPlusPlus11 || RD->isInvalidDecl())
return false;
// C++11 [expr.lambda.prim]p19:
// The closure type associated with a lambda-expression has a
// deleted (8.4.3) default constructor and a deleted copy
// assignment operator.
// C++2a adds back these operators if the lambda has no lambda-capture.
if (RD->isLambda() && !RD->lambdaIsDefaultConstructibleAndAssignable() &&
(CSM == CXXDefaultConstructor || CSM == CXXCopyAssignment)) {
if (Diagnose)
Diag(RD->getLocation(), diag::note_lambda_decl);
return true;
}
// For an anonymous struct or union, the copy and assignment special members
// will never be used, so skip the check. For an anonymous union declared at
// namespace scope, the constructor and destructor are used.
if (CSM != CXXDefaultConstructor && CSM != CXXDestructor &&
RD->isAnonymousStructOrUnion())
return false;
// C++11 [class.copy]p7, p18:
// If the class definition declares a move constructor or move assignment
// operator, an implicitly declared copy constructor or copy assignment
// operator is defined as deleted.
if (MD->isImplicit() &&
(CSM == CXXCopyConstructor || CSM == CXXCopyAssignment)) {
CXXMethodDecl *UserDeclaredMove = nullptr;
// In Microsoft mode up to MSVC 2013, a user-declared move only causes the
// deletion of the corresponding copy operation, not both copy operations.
// MSVC 2015 has adopted the standards conforming behavior.
bool DeletesOnlyMatchingCopy =
getLangOpts().MSVCCompat &&
!getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015);
if (RD->hasUserDeclaredMoveConstructor() &&
(!DeletesOnlyMatchingCopy || CSM == CXXCopyConstructor)) {
if (!Diagnose) return true;
// Find any user-declared move constructor.
for (auto *I : RD->ctors()) {
if (I->isMoveConstructor()) {
UserDeclaredMove = I;
break;
}
}
assert(UserDeclaredMove);
} else if (RD->hasUserDeclaredMoveAssignment() &&
(!DeletesOnlyMatchingCopy || CSM == CXXCopyAssignment)) {
if (!Diagnose) return true;
// Find any user-declared move assignment operator.
for (auto *I : RD->methods()) {
if (I->isMoveAssignmentOperator()) {
UserDeclaredMove = I;
break;
}
}
assert(UserDeclaredMove);
}
if (UserDeclaredMove) {
Diag(UserDeclaredMove->getLocation(),
diag::note_deleted_copy_user_declared_move)
<< (CSM == CXXCopyAssignment) << RD
<< UserDeclaredMove->isMoveAssignmentOperator();
return true;
}
}
// Do access control from the special member function
ContextRAII MethodContext(*this, MD);
// C++11 [class.dtor]p5:
// -- for a virtual destructor, lookup of the non-array deallocation function
// results in an ambiguity or in a function that is deleted or inaccessible
if (CSM == CXXDestructor && MD->isVirtual()) {
FunctionDecl *OperatorDelete = nullptr;
DeclarationName Name =
Context.DeclarationNames.getCXXOperatorName(OO_Delete);
if (FindDeallocationFunction(MD->getLocation(), MD->getParent(), Name,
OperatorDelete, /*Diagnose*/false)) {
if (Diagnose)
Diag(RD->getLocation(), diag::note_deleted_dtor_no_operator_delete);
return true;
}
}
SpecialMemberDeletionInfo SMI(*this, MD, CSM, ICI, Diagnose);
// Per DR1611, do not consider virtual bases of constructors of abstract
// classes, since we are not going to construct them.
// Per DR1658, do not consider virtual bases of destructors of abstract
// classes either.
// Per DR2180, for assignment operators we only assign (and thus only
// consider) direct bases.
if (SMI.visit(SMI.IsAssignment ? SMI.VisitDirectBases
: SMI.VisitPotentiallyConstructedBases))
return true;
if (SMI.shouldDeleteForAllConstMembers())
return true;
if (getLangOpts().CUDA) {
// We should delete the special member in CUDA mode if target inference
// failed.
// For inherited constructors (non-null ICI), CSM may be passed so that MD
// is treated as certain special member, which may not reflect what special
// member MD really is. However inferCUDATargetForImplicitSpecialMember
// expects CSM to match MD, therefore recalculate CSM.
assert(ICI || CSM == getSpecialMember(MD));
auto RealCSM = CSM;
if (ICI)
RealCSM = getSpecialMember(MD);
return inferCUDATargetForImplicitSpecialMember(RD, RealCSM, MD,
SMI.ConstArg, Diagnose);
}
return false;
}
void Sema::DiagnoseDeletedDefaultedFunction(FunctionDecl *FD) {
DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD);
assert(DFK && "not a defaultable function");
assert(FD->isDefaulted() && FD->isDeleted() && "not defaulted and deleted");
if (DFK.isSpecialMember()) {
ShouldDeleteSpecialMember(cast<CXXMethodDecl>(FD), DFK.asSpecialMember(),
nullptr, /*Diagnose=*/true);
} else {
DefaultedComparisonAnalyzer(
*this, cast<CXXRecordDecl>(FD->getLexicalDeclContext()), FD,
DFK.asComparison(), DefaultedComparisonAnalyzer::ExplainDeleted)
.visit();
}
}
/// Perform lookup for a special member of the specified kind, and determine
/// whether it is trivial. If the triviality can be determined without the
/// lookup, skip it. This is intended for use when determining whether a
/// special member of a containing object is trivial, and thus does not ever
/// perform overload resolution for default constructors.
///
/// If \p Selected is not \c NULL, \c *Selected will be filled in with the
/// member that was most likely to be intended to be trivial, if any.
///
/// If \p ForCall is true, look at CXXRecord::HasTrivialSpecialMembersForCall to
/// determine whether the special member is trivial.
static bool findTrivialSpecialMember(Sema &S, CXXRecordDecl *RD,
Sema::CXXSpecialMember CSM, unsigned Quals,
bool ConstRHS,
Sema::TrivialABIHandling TAH,
CXXMethodDecl **Selected) {
if (Selected)
*Selected = nullptr;
switch (CSM) {
case Sema::CXXInvalid:
llvm_unreachable("not a special member");
case Sema::CXXDefaultConstructor:
// C++11 [class.ctor]p5:
// A default constructor is trivial if:
// - all the [direct subobjects] have trivial default constructors
//
// Note, no overload resolution is performed in this case.
if (RD->hasTrivialDefaultConstructor())
return true;
if (Selected) {
// If there's a default constructor which could have been trivial, dig it
// out. Otherwise, if there's any user-provided default constructor, point
// to that as an example of why there's not a trivial one.
CXXConstructorDecl *DefCtor = nullptr;
if (RD->needsImplicitDefaultConstructor())
S.DeclareImplicitDefaultConstructor(RD);
for (auto *CI : RD->ctors()) {
if (!CI->isDefaultConstructor())
continue;
DefCtor = CI;
if (!DefCtor->isUserProvided())
break;
}
*Selected = DefCtor;
}
return false;
case Sema::CXXDestructor:
// C++11 [class.dtor]p5:
// A destructor is trivial if:
// - all the direct [subobjects] have trivial destructors
if (RD->hasTrivialDestructor() ||
(TAH == Sema::TAH_ConsiderTrivialABI &&
RD->hasTrivialDestructorForCall()))
return true;
if (Selected) {
if (RD->needsImplicitDestructor())
S.DeclareImplicitDestructor(RD);
*Selected = RD->getDestructor();
}
return false;
case Sema::CXXCopyConstructor:
// C++11 [class.copy]p12:
// A copy constructor is trivial if:
// - the constructor selected to copy each direct [subobject] is trivial
if (RD->hasTrivialCopyConstructor() ||
(TAH == Sema::TAH_ConsiderTrivialABI &&
RD->hasTrivialCopyConstructorForCall())) {
if (Quals == Qualifiers::Const)
// We must either select the trivial copy constructor or reach an
// ambiguity; no need to actually perform overload resolution.
return true;
} else if (!Selected) {
return false;
}
// In C++98, we are not supposed to perform overload resolution here, but we
// treat that as a language defect, as suggested on cxx-abi-dev, to treat
// cases like B as having a non-trivial copy constructor:
// struct A { template<typename T> A(T&); };
// struct B { mutable A a; };
goto NeedOverloadResolution;
case Sema::CXXCopyAssignment:
// C++11 [class.copy]p25:
// A copy assignment operator is trivial if:
// - the assignment operator selected to copy each direct [subobject] is
// trivial
if (RD->hasTrivialCopyAssignment()) {
if (Quals == Qualifiers::Const)
return true;
} else if (!Selected) {
return false;
}
// In C++98, we are not supposed to perform overload resolution here, but we
// treat that as a language defect.
goto NeedOverloadResolution;
case Sema::CXXMoveConstructor:
case Sema::CXXMoveAssignment:
NeedOverloadResolution:
Sema::SpecialMemberOverloadResult SMOR =
lookupCallFromSpecialMember(S, RD, CSM, Quals, ConstRHS);
// The standard doesn't describe how to behave if the lookup is ambiguous.
// We treat it as not making the member non-trivial, just like the standard
// mandates for the default constructor. This should rarely matter, because
// the member will also be deleted.
if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
return true;
if (!SMOR.getMethod()) {
assert(SMOR.getKind() ==
Sema::SpecialMemberOverloadResult::NoMemberOrDeleted);
return false;
}
// We deliberately don't check if we found a deleted special member. We're
// not supposed to!
if (Selected)
*Selected = SMOR.getMethod();
if (TAH == Sema::TAH_ConsiderTrivialABI &&
(CSM == Sema::CXXCopyConstructor || CSM == Sema::CXXMoveConstructor))
return SMOR.getMethod()->isTrivialForCall();
return SMOR.getMethod()->isTrivial();
}
llvm_unreachable("unknown special method kind");
}
static CXXConstructorDecl *findUserDeclaredCtor(CXXRecordDecl *RD) {
for (auto *CI : RD->ctors())
if (!CI->isImplicit())
return CI;
// Look for constructor templates.
typedef CXXRecordDecl::specific_decl_iterator<FunctionTemplateDecl> tmpl_iter;
for (tmpl_iter TI(RD->decls_begin()), TE(RD->decls_end()); TI != TE; ++TI) {
if (CXXConstructorDecl *CD =
dyn_cast<CXXConstructorDecl>(TI->getTemplatedDecl()))
return CD;
}
return nullptr;
}
/// The kind of subobject we are checking for triviality. The values of this
/// enumeration are used in diagnostics.
enum TrivialSubobjectKind {
/// The subobject is a base class.
TSK_BaseClass,
/// The subobject is a non-static data member.
TSK_Field,
/// The object is actually the complete object.
TSK_CompleteObject
};
/// Check whether the special member selected for a given type would be trivial.
static bool checkTrivialSubobjectCall(Sema &S, SourceLocation SubobjLoc,
QualType SubType, bool ConstRHS,
Sema::CXXSpecialMember CSM,
TrivialSubobjectKind Kind,
Sema::TrivialABIHandling TAH, bool Diagnose) {
CXXRecordDecl *SubRD = SubType->getAsCXXRecordDecl();
if (!SubRD)
return true;
CXXMethodDecl *Selected;
if (findTrivialSpecialMember(S, SubRD, CSM, SubType.getCVRQualifiers(),
ConstRHS, TAH, Diagnose ? &Selected : nullptr))
return true;
if (Diagnose) {
if (ConstRHS)
SubType.addConst();
if (!Selected && CSM == Sema::CXXDefaultConstructor) {
S.Diag(SubobjLoc, diag::note_nontrivial_no_def_ctor)
<< Kind << SubType.getUnqualifiedType();
if (CXXConstructorDecl *CD = findUserDeclaredCtor(SubRD))
S.Diag(CD->getLocation(), diag::note_user_declared_ctor);
} else if (!Selected)
S.Diag(SubobjLoc, diag::note_nontrivial_no_copy)
<< Kind << SubType.getUnqualifiedType() << CSM << SubType;
else if (Selected->isUserProvided()) {
if (Kind == TSK_CompleteObject)
S.Diag(Selected->getLocation(), diag::note_nontrivial_user_provided)
<< Kind << SubType.getUnqualifiedType() << CSM;
else {
S.Diag(SubobjLoc, diag::note_nontrivial_user_provided)
<< Kind << SubType.getUnqualifiedType() << CSM;
S.Diag(Selected->getLocation(), diag::note_declared_at);
}
} else {
if (Kind != TSK_CompleteObject)
S.Diag(SubobjLoc, diag::note_nontrivial_subobject)
<< Kind << SubType.getUnqualifiedType() << CSM;
// Explain why the defaulted or deleted special member isn't trivial.
S.SpecialMemberIsTrivial(Selected, CSM, Sema::TAH_IgnoreTrivialABI,
Diagnose);
}
}
return false;
}
/// Check whether the members of a class type allow a special member to be
/// trivial.
static bool checkTrivialClassMembers(Sema &S, CXXRecordDecl *RD,
Sema::CXXSpecialMember CSM,
bool ConstArg,
Sema::TrivialABIHandling TAH,
bool Diagnose) {
for (const auto *FI : RD->fields()) {
if (FI->isInvalidDecl() || FI->isUnnamedBitfield())
continue;
QualType FieldType = S.Context.getBaseElementType(FI->getType());
// Pretend anonymous struct or union members are members of this class.
if (FI->isAnonymousStructOrUnion()) {
if (!checkTrivialClassMembers(S, FieldType->getAsCXXRecordDecl(),
CSM, ConstArg, TAH, Diagnose))
return false;
continue;
}
// C++11 [class.ctor]p5:
// A default constructor is trivial if [...]
// -- no non-static data member of its class has a
// brace-or-equal-initializer
if (CSM == Sema::CXXDefaultConstructor && FI->hasInClassInitializer()) {
if (Diagnose)
S.Diag(FI->getLocation(), diag::note_nontrivial_default_member_init)
<< FI;
return false;
}
// Objective C ARC 4.3.5:
// [...] nontrivally ownership-qualified types are [...] not trivially
// default constructible, copy constructible, move constructible, copy
// assignable, move assignable, or destructible [...]
if (FieldType.hasNonTrivialObjCLifetime()) {
if (Diagnose)
S.Diag(FI->getLocation(), diag::note_nontrivial_objc_ownership)
<< RD << FieldType.getObjCLifetime();
return false;
}
bool ConstRHS = ConstArg && !FI->isMutable();
if (!checkTrivialSubobjectCall(S, FI->getLocation(), FieldType, ConstRHS,
CSM, TSK_Field, TAH, Diagnose))
return false;
}
return true;
}
/// Diagnose why the specified class does not have a trivial special member of
/// the given kind.
void Sema::DiagnoseNontrivial(const CXXRecordDecl *RD, CXXSpecialMember CSM) {
QualType Ty = Context.getRecordType(RD);
bool ConstArg = (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment);
checkTrivialSubobjectCall(*this, RD->getLocation(), Ty, ConstArg, CSM,
TSK_CompleteObject, TAH_IgnoreTrivialABI,
/*Diagnose*/true);
}
/// Determine whether a defaulted or deleted special member function is trivial,
/// as specified in C++11 [class.ctor]p5, C++11 [class.copy]p12,
/// C++11 [class.copy]p25, and C++11 [class.dtor]p5.
bool Sema::SpecialMemberIsTrivial(CXXMethodDecl *MD, CXXSpecialMember CSM,
TrivialABIHandling TAH, bool Diagnose) {
assert(!MD->isUserProvided() && CSM != CXXInvalid && "not special enough");
CXXRecordDecl *RD = MD->getParent();
bool ConstArg = false;
// C++11 [class.copy]p12, p25: [DR1593]
// A [special member] is trivial if [...] its parameter-type-list is
// equivalent to the parameter-type-list of an implicit declaration [...]
switch (CSM) {
case CXXDefaultConstructor:
case CXXDestructor:
// Trivial default constructors and destructors cannot have parameters.
break;
case CXXCopyConstructor:
case CXXCopyAssignment: {
// Trivial copy operations always have const, non-volatile parameter types.
ConstArg = true;
const ParmVarDecl *Param0 = MD->getParamDecl(0);
const ReferenceType *RT = Param0->getType()->getAs<ReferenceType>();
if (!RT || RT->getPointeeType().getCVRQualifiers() != Qualifiers::Const) {
if (Diagnose)
Diag(Param0->getLocation(), diag::note_nontrivial_param_type)
<< Param0->getSourceRange() << Param0->getType()
<< Context.getLValueReferenceType(
Context.getRecordType(RD).withConst());
return false;
}
break;
}
case CXXMoveConstructor:
case CXXMoveAssignment: {
// Trivial move operations always have non-cv-qualified parameters.
const ParmVarDecl *Param0 = MD->getParamDecl(0);
const RValueReferenceType *RT =
Param0->getType()->getAs<RValueReferenceType>();
if (!RT || RT->getPointeeType().getCVRQualifiers()) {
if (Diagnose)
Diag(Param0->getLocation(), diag::note_nontrivial_param_type)
<< Param0->getSourceRange() << Param0->getType()
<< Context.getRValueReferenceType(Context.getRecordType(RD));
return false;
}
break;
}
case CXXInvalid:
llvm_unreachable("not a special member");
}
if (MD->getMinRequiredArguments() < MD->getNumParams()) {
if (Diagnose)
Diag(MD->getParamDecl(MD->getMinRequiredArguments())->getLocation(),
diag::note_nontrivial_default_arg)
<< MD->getParamDecl(MD->getMinRequiredArguments())->getSourceRange();
return false;
}
if (MD->isVariadic()) {
if (Diagnose)
Diag(MD->getLocation(), diag::note_nontrivial_variadic);
return false;
}
// C++11 [class.ctor]p5, C++11 [class.dtor]p5:
// A copy/move [constructor or assignment operator] is trivial if
// -- the [member] selected to copy/move each direct base class subobject
// is trivial
//
// C++11 [class.copy]p12, C++11 [class.copy]p25:
// A [default constructor or destructor] is trivial if
// -- all the direct base classes have trivial [default constructors or
// destructors]
for (const auto &BI : RD->bases())
if (!checkTrivialSubobjectCall(*this, BI.getBeginLoc(), BI.getType(),
ConstArg, CSM, TSK_BaseClass, TAH, Diagnose))
return false;
// C++11 [class.ctor]p5, C++11 [class.dtor]p5:
// A copy/move [constructor or assignment operator] for a class X is
// trivial if
// -- for each non-static data member of X that is of class type (or array
// thereof), the constructor selected to copy/move that member is
// trivial
//
// C++11 [class.copy]p12, C++11 [class.copy]p25:
// A [default constructor or destructor] is trivial if
// -- for all of the non-static data members of its class that are of class
// type (or array thereof), each such class has a trivial [default
// constructor or destructor]
if (!checkTrivialClassMembers(*this, RD, CSM, ConstArg, TAH, Diagnose))
return false;
// C++11 [class.dtor]p5:
// A destructor is trivial if [...]
// -- the destructor is not virtual
if (CSM == CXXDestructor && MD->isVirtual()) {
if (Diagnose)
Diag(MD->getLocation(), diag::note_nontrivial_virtual_dtor) << RD;
return false;
}
// C++11 [class.ctor]p5, C++11 [class.copy]p12, C++11 [class.copy]p25:
// A [special member] for class X is trivial if [...]
// -- class X has no virtual functions and no virtual base classes
if (CSM != CXXDestructor && MD->getParent()->isDynamicClass()) {
if (!Diagnose)
return false;
if (RD->getNumVBases()) {
// Check for virtual bases. We already know that the corresponding
// member in all bases is trivial, so vbases must all be direct.
CXXBaseSpecifier &BS = *RD->vbases_begin();
assert(BS.isVirtual());
Diag(BS.getBeginLoc(), diag::note_nontrivial_has_virtual) << RD << 1;
return false;
}
// Must have a virtual method.
for (const auto *MI : RD->methods()) {
if (MI->isVirtual()) {
SourceLocation MLoc = MI->getBeginLoc();
Diag(MLoc, diag::note_nontrivial_has_virtual) << RD << 0;
return false;
}
}
llvm_unreachable("dynamic class with no vbases and no virtual functions");
}
// Looks like it's trivial!
return true;
}
namespace {
struct FindHiddenVirtualMethod {
Sema *S;
CXXMethodDecl *Method;
llvm::SmallPtrSet<const CXXMethodDecl *, 8> OverridenAndUsingBaseMethods;
SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
private:
/// Check whether any most overridden method from MD in Methods
static bool CheckMostOverridenMethods(
const CXXMethodDecl *MD,
const llvm::SmallPtrSetImpl<const CXXMethodDecl *> &Methods) {
if (MD->size_overridden_methods() == 0)
return Methods.count(MD->getCanonicalDecl());
for (const CXXMethodDecl *O : MD->overridden_methods())
if (CheckMostOverridenMethods(O, Methods))
return true;
return false;
}
public:
/// Member lookup function that determines whether a given C++
/// method overloads virtual methods in a base class without overriding any,
/// to be used with CXXRecordDecl::lookupInBases().
bool operator()(const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
RecordDecl *BaseRecord =
Specifier->getType()->castAs<RecordType>()->getDecl();
DeclarationName Name = Method->getDeclName();
assert(Name.getNameKind() == DeclarationName::Identifier);
bool foundSameNameMethod = false;
SmallVector<CXXMethodDecl *, 8> overloadedMethods;
for (Path.Decls = BaseRecord->lookup(Name).begin();
Path.Decls != DeclContext::lookup_iterator(); ++Path.Decls) {
NamedDecl *D = *Path.Decls;
if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
MD = MD->getCanonicalDecl();
foundSameNameMethod = true;
// Interested only in hidden virtual methods.
if (!MD->isVirtual())
continue;
// If the method we are checking overrides a method from its base
// don't warn about the other overloaded methods. Clang deviates from
// GCC by only diagnosing overloads of inherited virtual functions that
// do not override any other virtual functions in the base. GCC's
// -Woverloaded-virtual diagnoses any derived function hiding a virtual
// function from a base class. These cases may be better served by a
// warning (not specific to virtual functions) on call sites when the
// call would select a different function from the base class, were it
// visible.
// See FIXME in test/SemaCXX/warn-overload-virtual.cpp for an example.
if (!S->IsOverload(Method, MD, false))
return true;
// Collect the overload only if its hidden.
if (!CheckMostOverridenMethods(MD, OverridenAndUsingBaseMethods))
overloadedMethods.push_back(MD);
}
}
if (foundSameNameMethod)
OverloadedMethods.append(overloadedMethods.begin(),
overloadedMethods.end());
return foundSameNameMethod;
}
};
} // end anonymous namespace
/// Add the most overridden methods from MD to Methods
static void AddMostOverridenMethods(const CXXMethodDecl *MD,
llvm::SmallPtrSetImpl<const CXXMethodDecl *>& Methods) {
if (MD->size_overridden_methods() == 0)
Methods.insert(MD->getCanonicalDecl());
else
for (const CXXMethodDecl *O : MD->overridden_methods())
AddMostOverridenMethods(O, Methods);
}
/// Check if a method overloads virtual methods in a base class without
/// overriding any.
void Sema::FindHiddenVirtualMethods(CXXMethodDecl *MD,
SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) {
if (!MD->getDeclName().isIdentifier())
return;
CXXBasePaths Paths(/*FindAmbiguities=*/true, // true to look in all bases.
/*bool RecordPaths=*/false,
/*bool DetectVirtual=*/false);
FindHiddenVirtualMethod FHVM;
FHVM.Method = MD;
FHVM.S = this;
// Keep the base methods that were overridden or introduced in the subclass
// by 'using' in a set. A base method not in this set is hidden.
CXXRecordDecl *DC = MD->getParent();
DeclContext::lookup_result R = DC->lookup(MD->getDeclName());
for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; ++I) {
NamedDecl *ND = *I;
if (UsingShadowDecl *shad = dyn_cast<UsingShadowDecl>(*I))
ND = shad->getTargetDecl();
if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
AddMostOverridenMethods(MD, FHVM.OverridenAndUsingBaseMethods);
}
if (DC->lookupInBases(FHVM, Paths))
OverloadedMethods = FHVM.OverloadedMethods;
}
void Sema::NoteHiddenVirtualMethods(CXXMethodDecl *MD,
SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) {
for (unsigned i = 0, e = OverloadedMethods.size(); i != e; ++i) {
CXXMethodDecl *overloadedMD = OverloadedMethods[i];
PartialDiagnostic PD = PDiag(
diag::note_hidden_overloaded_virtual_declared_here) << overloadedMD;
HandleFunctionTypeMismatch(PD, MD->getType(), overloadedMD->getType());
Diag(overloadedMD->getLocation(), PD);
}
}
/// Diagnose methods which overload virtual methods in a base class
/// without overriding any.
void Sema::DiagnoseHiddenVirtualMethods(CXXMethodDecl *MD) {
if (MD->isInvalidDecl())
return;
if (Diags.isIgnored(diag::warn_overloaded_virtual, MD->getLocation()))
return;
SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
FindHiddenVirtualMethods(MD, OverloadedMethods);
if (!OverloadedMethods.empty()) {
Diag(MD->getLocation(), diag::warn_overloaded_virtual)
<< MD << (OverloadedMethods.size() > 1);
NoteHiddenVirtualMethods(MD, OverloadedMethods);
}
}
void Sema::checkIllFormedTrivialABIStruct(CXXRecordDecl &RD) {
auto PrintDiagAndRemoveAttr = [&](unsigned N) {
// No diagnostics if this is a template instantiation.
if (!isTemplateInstantiation(RD.getTemplateSpecializationKind())) {
Diag(RD.getAttr<TrivialABIAttr>()->getLocation(),
diag::ext_cannot_use_trivial_abi) << &RD;
Diag(RD.getAttr<TrivialABIAttr>()->getLocation(),
diag::note_cannot_use_trivial_abi_reason) << &RD << N;
}
RD.dropAttr<TrivialABIAttr>();
};
// Ill-formed if the copy and move constructors are deleted.
auto HasNonDeletedCopyOrMoveConstructor = [&]() {
// If the type is dependent, then assume it might have
// implicit copy or move ctor because we won't know yet at this point.
if (RD.isDependentType())
return true;
if (RD.needsImplicitCopyConstructor() &&
!RD.defaultedCopyConstructorIsDeleted())
return true;
if (RD.needsImplicitMoveConstructor() &&
!RD.defaultedMoveConstructorIsDeleted())
return true;
for (const CXXConstructorDecl *CD : RD.ctors())
if (CD->isCopyOrMoveConstructor() && !CD->isDeleted())
return true;
return false;
};
if (!HasNonDeletedCopyOrMoveConstructor()) {
PrintDiagAndRemoveAttr(0);
return;
}
// Ill-formed if the struct has virtual functions.
if (RD.isPolymorphic()) {
PrintDiagAndRemoveAttr(1);
return;
}
for (const auto &B : RD.bases()) {
// Ill-formed if the base class is non-trivial for the purpose of calls or a
// virtual base.
if (!B.getType()->isDependentType() &&
!B.getType()->getAsCXXRecordDecl()->canPassInRegisters()) {
PrintDiagAndRemoveAttr(2);
return;
}
if (B.isVirtual()) {
PrintDiagAndRemoveAttr(3);
return;
}
}
for (const auto *FD : RD.fields()) {
// Ill-formed if the field is an ObjectiveC pointer or of a type that is
// non-trivial for the purpose of calls.
QualType FT = FD->getType();
if (FT.getObjCLifetime() == Qualifiers::OCL_Weak) {
PrintDiagAndRemoveAttr(4);
return;
}
if (const auto *RT = FT->getBaseElementTypeUnsafe()->getAs<RecordType>())
if (!RT->isDependentType() &&
!cast<CXXRecordDecl>(RT->getDecl())->canPassInRegisters()) {
PrintDiagAndRemoveAttr(5);
return;
}
}
}
void Sema::ActOnFinishCXXMemberSpecification(
Scope *S, SourceLocation RLoc, Decl *TagDecl, SourceLocation LBrac,
SourceLocation RBrac, const ParsedAttributesView &AttrList) {
if (!TagDecl)
return;
AdjustDeclIfTemplate(TagDecl);
for (const ParsedAttr &AL : AttrList) {
if (AL.getKind() != ParsedAttr::AT_Visibility)
continue;
AL.setInvalid();
Diag(AL.getLoc(), diag::warn_attribute_after_definition_ignored) << AL;
}
ActOnFields(S, RLoc, TagDecl, llvm::makeArrayRef(
// strict aliasing violation!
reinterpret_cast<Decl**>(FieldCollector->getCurFields()),
FieldCollector->getCurNumFields()), LBrac, RBrac, AttrList);
CheckCompletedCXXClass(S, cast<CXXRecordDecl>(TagDecl));
}
/// Find the equality comparison functions that should be implicitly declared
/// in a given class definition, per C++2a [class.compare.default]p3.
static void findImplicitlyDeclaredEqualityComparisons(
ASTContext &Ctx, CXXRecordDecl *RD,
llvm::SmallVectorImpl<FunctionDecl *> &Spaceships) {
DeclarationName EqEq = Ctx.DeclarationNames.getCXXOperatorName(OO_EqualEqual);
if (!RD->lookup(EqEq).empty())
// Member operator== explicitly declared: no implicit operator==s.
return;
// Traverse friends looking for an '==' or a '<=>'.
for (FriendDecl *Friend : RD->friends()) {
FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(Friend->getFriendDecl());
if (!FD) continue;
if (FD->getOverloadedOperator() == OO_EqualEqual) {
// Friend operator== explicitly declared: no implicit operator==s.
Spaceships.clear();
return;
}
if (FD->getOverloadedOperator() == OO_Spaceship &&
FD->isExplicitlyDefaulted())
Spaceships.push_back(FD);
}
// Look for members named 'operator<=>'.
DeclarationName Cmp = Ctx.DeclarationNames.getCXXOperatorName(OO_Spaceship);
for (NamedDecl *ND : RD->lookup(Cmp)) {
// Note that we could find a non-function here (either a function template
// or a using-declaration). Neither case results in an implicit
// 'operator=='.
if (auto *FD = dyn_cast<FunctionDecl>(ND))
if (FD->isExplicitlyDefaulted())
Spaceships.push_back(FD);
}
}
/// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared
/// special functions, such as the default constructor, copy
/// constructor, or destructor, to the given C++ class (C++
/// [special]p1). This routine can only be executed just before the
/// definition of the class is complete.
void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
// Don't add implicit special members to templated classes.
// FIXME: This means unqualified lookups for 'operator=' within a class
// template don't work properly.
if (!ClassDecl->isDependentType()) {
if (ClassDecl->needsImplicitDefaultConstructor()) {
++getASTContext().NumImplicitDefaultConstructors;
if (ClassDecl->hasInheritedConstructor())
DeclareImplicitDefaultConstructor(ClassDecl);
}
if (ClassDecl->needsImplicitCopyConstructor()) {
++getASTContext().NumImplicitCopyConstructors;
// If the properties or semantics of the copy constructor couldn't be
// determined while the class was being declared, force a declaration
// of it now.
if (ClassDecl->needsOverloadResolutionForCopyConstructor() ||
ClassDecl->hasInheritedConstructor())
DeclareImplicitCopyConstructor(ClassDecl);
// For the MS ABI we need to know whether the copy ctor is deleted. A
// prerequisite for deleting the implicit copy ctor is that the class has
// a move ctor or move assignment that is either user-declared or whose
// semantics are inherited from a subobject. FIXME: We should provide a
// more direct way for CodeGen to ask whether the constructor was deleted.
else if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
(ClassDecl->hasUserDeclaredMoveConstructor() ||
ClassDecl->needsOverloadResolutionForMoveConstructor() ||
ClassDecl->hasUserDeclaredMoveAssignment() ||
ClassDecl->needsOverloadResolutionForMoveAssignment()))
DeclareImplicitCopyConstructor(ClassDecl);
}
if (getLangOpts().CPlusPlus11 &&
ClassDecl->needsImplicitMoveConstructor()) {
++getASTContext().NumImplicitMoveConstructors;
if (ClassDecl->needsOverloadResolutionForMoveConstructor() ||
ClassDecl->hasInheritedConstructor())
DeclareImplicitMoveConstructor(ClassDecl);
}
if (ClassDecl->needsImplicitCopyAssignment()) {
++getASTContext().NumImplicitCopyAssignmentOperators;
// If we have a dynamic class, then the copy assignment operator may be
// virtual, so we have to declare it immediately. This ensures that, e.g.,
// it shows up in the right place in the vtable and that we diagnose
// problems with the implicit exception specification.
if (ClassDecl->isDynamicClass() ||
ClassDecl->needsOverloadResolutionForCopyAssignment() ||
ClassDecl->hasInheritedAssignment())
DeclareImplicitCopyAssignment(ClassDecl);
}
if (getLangOpts().CPlusPlus11 && ClassDecl->needsImplicitMoveAssignment()) {
++getASTContext().NumImplicitMoveAssignmentOperators;
// Likewise for the move assignment operator.
if (ClassDecl->isDynamicClass() ||
ClassDecl->needsOverloadResolutionForMoveAssignment() ||
ClassDecl->hasInheritedAssignment())
DeclareImplicitMoveAssignment(ClassDecl);
}
if (ClassDecl->needsImplicitDestructor()) {
++getASTContext().NumImplicitDestructors;
// If we have a dynamic class, then the destructor may be virtual, so we
// have to declare the destructor immediately. This ensures that, e.g., it
// shows up in the right place in the vtable and that we diagnose problems
// with the implicit exception specification.
if (ClassDecl->isDynamicClass() ||
ClassDecl->needsOverloadResolutionForDestructor())
DeclareImplicitDestructor(ClassDecl);
}
}
// C++2a [class.compare.default]p3:
// If the member-specification does not explicitly declare any member or
// friend named operator==, an == operator function is declared implicitly
// for each defaulted three-way comparison operator function defined in
// the member-specification
// FIXME: Consider doing this lazily.
// We do this during the initial parse for a class template, not during
// instantiation, so that we can handle unqualified lookups for 'operator=='
// when parsing the template.
if (getLangOpts().CPlusPlus20 && !inTemplateInstantiation()) {
llvm::SmallVector<FunctionDecl *, 4> DefaultedSpaceships;
findImplicitlyDeclaredEqualityComparisons(Context, ClassDecl,
DefaultedSpaceships);
for (auto *FD : DefaultedSpaceships)
DeclareImplicitEqualityComparison(ClassDecl, FD);
}
}
unsigned
Sema::ActOnReenterTemplateScope(Decl *D,
llvm::function_ref<Scope *()> EnterScope) {
if (!D)
return 0;
AdjustDeclIfTemplate(D);
// In order to get name lookup right, reenter template scopes in order from
// outermost to innermost.
SmallVector<TemplateParameterList *, 4> ParameterLists;
DeclContext *LookupDC = dyn_cast<DeclContext>(D);
if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
for (unsigned i = 0; i < DD->getNumTemplateParameterLists(); ++i)
ParameterLists.push_back(DD->getTemplateParameterList(i));
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
if (FunctionTemplateDecl *FTD = FD->getDescribedFunctionTemplate())
ParameterLists.push_back(FTD->getTemplateParameters());
} else if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
LookupDC = VD->getDeclContext();
if (VarTemplateDecl *VTD = VD->getDescribedVarTemplate())
ParameterLists.push_back(VTD->getTemplateParameters());
else if (auto *PSD = dyn_cast<VarTemplatePartialSpecializationDecl>(D))
ParameterLists.push_back(PSD->getTemplateParameters());
}
} else if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
for (unsigned i = 0; i < TD->getNumTemplateParameterLists(); ++i)
ParameterLists.push_back(TD->getTemplateParameterList(i));
if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) {
if (ClassTemplateDecl *CTD = RD->getDescribedClassTemplate())
ParameterLists.push_back(CTD->getTemplateParameters());
else if (auto *PSD = dyn_cast<ClassTemplatePartialSpecializationDecl>(D))
ParameterLists.push_back(PSD->getTemplateParameters());
}
}
// FIXME: Alias declarations and concepts.
unsigned Count = 0;
Scope *InnermostTemplateScope = nullptr;
for (TemplateParameterList *Params : ParameterLists) {
// Ignore explicit specializations; they don't contribute to the template
// depth.
if (Params->size() == 0)
continue;
InnermostTemplateScope = EnterScope();
for (NamedDecl *Param : *Params) {
if (Param->getDeclName()) {
InnermostTemplateScope->AddDecl(Param);
IdResolver.AddDecl(Param);
}
}
++Count;
}
// Associate the new template scopes with the corresponding entities.
if (InnermostTemplateScope) {
assert(LookupDC && "no enclosing DeclContext for template lookup");
EnterTemplatedContext(InnermostTemplateScope, LookupDC);
}
return Count;
}
void Sema::ActOnStartDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
if (!RecordD) return;
AdjustDeclIfTemplate(RecordD);
CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordD);
PushDeclContext(S, Record);
}
void Sema::ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
if (!RecordD) return;
PopDeclContext();
}
/// This is used to implement the constant expression evaluation part of the
/// attribute enable_if extension. There is nothing in standard C++ which would
/// require reentering parameters.
void Sema::ActOnReenterCXXMethodParameter(Scope *S, ParmVarDecl *Param) {
if (!Param)
return;
S->AddDecl(Param);
if (Param->getDeclName())
IdResolver.AddDecl(Param);
}
/// ActOnStartDelayedCXXMethodDeclaration - We have completed
/// parsing a top-level (non-nested) C++ class, and we are now
/// parsing those parts of the given Method declaration that could
/// not be parsed earlier (C++ [class.mem]p2), such as default
/// arguments. This action should enter the scope of the given
/// Method declaration as if we had just parsed the qualified method
/// name. However, it should not bring the parameters into scope;
/// that will be performed by ActOnDelayedCXXMethodParameter.
void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
}
/// ActOnDelayedCXXMethodParameter - We've already started a delayed
/// C++ method declaration. We're (re-)introducing the given
/// function parameter into scope for use in parsing later parts of
/// the method declaration. For example, we could see an
/// ActOnParamDefaultArgument event for this parameter.
void Sema::ActOnDelayedCXXMethodParameter(Scope *S, Decl *ParamD) {
if (!ParamD)
return;
ParmVarDecl *Param = cast<ParmVarDecl>(ParamD);
S->AddDecl(Param);
if (Param->getDeclName())
IdResolver.AddDecl(Param);
}
/// ActOnFinishDelayedCXXMethodDeclaration - We have finished
/// processing the delayed method declaration for Method. The method
/// declaration is now considered finished. There may be a separate
/// ActOnStartOfFunctionDef action later (not necessarily
/// immediately!) for this method, if it was also defined inside the
/// class body.
void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
if (!MethodD)
return;
AdjustDeclIfTemplate(MethodD);
FunctionDecl *Method = cast<FunctionDecl>(MethodD);
// Now that we have our default arguments, check the constructor
// again. It could produce additional diagnostics or affect whether
// the class has implicitly-declared destructors, among other
// things.
if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method))
CheckConstructor(Constructor);
// Check the default arguments, which we may have added.
if (!Method->isInvalidDecl())
CheckCXXDefaultArguments(Method);
}
// Emit the given diagnostic for each non-address-space qualifier.
// Common part of CheckConstructorDeclarator and CheckDestructorDeclarator.
static void checkMethodTypeQualifiers(Sema &S, Declarator &D, unsigned DiagID) {
const DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
if (FTI.hasMethodTypeQualifiers() && !D.isInvalidType()) {
bool DiagOccured = false;
FTI.MethodQualifiers->forEachQualifier(
[DiagID, &S, &DiagOccured](DeclSpec::TQ, StringRef QualName,
SourceLocation SL) {
// This diagnostic should be emitted on any qualifier except an addr
// space qualifier. However, forEachQualifier currently doesn't visit
// addr space qualifiers, so there's no way to write this condition
// right now; we just diagnose on everything.
S.Diag(SL, DiagID) << QualName << SourceRange(SL);
DiagOccured = true;
});
if (DiagOccured)
D.setInvalidType();
}
}
/// CheckConstructorDeclarator - Called by ActOnDeclarator to check
/// the well-formedness of the constructor declarator @p D with type @p
/// R. If there are any errors in the declarator, this routine will
/// emit diagnostics and set the invalid bit to true. In any case, the type
/// will be updated to reflect a well-formed type for the constructor and
/// returned.
QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R,
StorageClass &SC) {
bool isVirtual = D.getDeclSpec().isVirtualSpecified();
// C++ [class.ctor]p3:
// A constructor shall not be virtual (10.3) or static (9.4). A
// constructor can be invoked for a const, volatile or const
// volatile object. A constructor shall not be declared const,
// volatile, or const volatile (9.3.2).
if (isVirtual) {
if (!D.isInvalidType())
Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
<< "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc())
<< SourceRange(D.getIdentifierLoc());
D.setInvalidType();
}
if (SC == SC_Static) {
if (!D.isInvalidType())
Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
<< "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
<< SourceRange(D.getIdentifierLoc());
D.setInvalidType();
SC = SC_None;
}
if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) {
diagnoseIgnoredQualifiers(
diag::err_constructor_return_type, TypeQuals, SourceLocation(),
D.getDeclSpec().getConstSpecLoc(), D.getDeclSpec().getVolatileSpecLoc(),
D.getDeclSpec().getRestrictSpecLoc(),
D.getDeclSpec().getAtomicSpecLoc());
D.setInvalidType();
}
checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_constructor);
// C++0x [class.ctor]p4:
// A constructor shall not be declared with a ref-qualifier.
DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
if (FTI.hasRefQualifier()) {
Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_constructor)
<< FTI.RefQualifierIsLValueRef
<< FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
D.setInvalidType();
}
// Rebuild the function type "R" without any type qualifiers (in
// case any of the errors above fired) and with "void" as the
// return type, since constructors don't have return types.
const FunctionProtoType *Proto = R->castAs<FunctionProtoType>();
if (Proto->getReturnType() == Context.VoidTy && !D.isInvalidType())
return R;
FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
EPI.TypeQuals = Qualifiers();
EPI.RefQualifier = RQ_None;
return Context.getFunctionType(Context.VoidTy, Proto->getParamTypes(), EPI);
}
/// CheckConstructor - Checks a fully-formed constructor for
/// well-formedness, issuing any diagnostics required. Returns true if
/// the constructor declarator is invalid.
void Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
CXXRecordDecl *ClassDecl
= dyn_cast<CXXRecordDecl>(Constructor->getDeclContext());
if (!ClassDecl)
return Constructor->setInvalidDecl();
// C++ [class.copy]p3:
// A declaration of a constructor for a class X is ill-formed if
// its first parameter is of type (optionally cv-qualified) X and
// either there are no other parameters or else all other
// parameters have default arguments.
if (!Constructor->isInvalidDecl() &&
Constructor->hasOneParamOrDefaultArgs() &&
Constructor->getTemplateSpecializationKind() !=
TSK_ImplicitInstantiation) {
QualType ParamType = Constructor->getParamDecl(0)->getType();
QualType ClassTy = Context.getTagDeclType(ClassDecl);
if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) {
SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation();
const char *ConstRef
= Constructor->getParamDecl(0)->getIdentifier() ? "const &"
: " const &";
Diag(ParamLoc, diag::err_constructor_byvalue_arg)
<< FixItHint::CreateInsertion(ParamLoc, ConstRef);
// FIXME: Rather that making the constructor invalid, we should endeavor
// to fix the type.
Constructor->setInvalidDecl();
}
}
}
/// CheckDestructor - Checks a fully-formed destructor definition for
/// well-formedness, issuing any diagnostics required. Returns true
/// on error.
bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
CXXRecordDecl *RD = Destructor->getParent();
if (!Destructor->getOperatorDelete() && Destructor->isVirtual()) {
SourceLocation Loc;
if (!Destructor->isImplicit())
Loc = Destructor->getLocation();
else
Loc = RD->getLocation();
// If we have a virtual destructor, look up the deallocation function
if (FunctionDecl *OperatorDelete =
FindDeallocationFunctionForDestructor(Loc, RD)) {
Expr *ThisArg = nullptr;
// If the notional 'delete this' expression requires a non-trivial
// conversion from 'this' to the type of a destroying operator delete's
// first parameter, perform that conversion now.
if (OperatorDelete->isDestroyingOperatorDelete()) {
QualType ParamType = OperatorDelete->getParamDecl(0)->getType();
if (!declaresSameEntity(ParamType->getAsCXXRecordDecl(), RD)) {
// C++ [class.dtor]p13:
// ... as if for the expression 'delete this' appearing in a
// non-virtual destructor of the destructor's class.
ContextRAII SwitchContext(*this, Destructor);
ExprResult This =
ActOnCXXThis(OperatorDelete->getParamDecl(0)->getLocation());
assert(!This.isInvalid() && "couldn't form 'this' expr in dtor?");
This = PerformImplicitConversion(This.get(), ParamType, AA_Passing);
if (This.isInvalid()) {
// FIXME: Register this as a context note so that it comes out
// in the right order.
Diag(Loc, diag::note_implicit_delete_this_in_destructor_here);
return true;
}
ThisArg = This.get();
}
}
DiagnoseUseOfDecl(OperatorDelete, Loc);
MarkFunctionReferenced(Loc, OperatorDelete);
Destructor->setOperatorDelete(OperatorDelete, ThisArg);
}
}
return false;
}
/// CheckDestructorDeclarator - Called by ActOnDeclarator to check
/// the well-formednes of the destructor declarator @p D with type @p
/// R. If there are any errors in the declarator, this routine will
/// emit diagnostics and set the declarator to invalid. Even if this happens,
/// will be updated to reflect a well-formed type for the destructor and
/// returned.
QualType Sema::CheckDestructorDeclarator(Declarator &D, QualType R,
StorageClass& SC) {
// C++ [class.dtor]p1:
// [...] A typedef-name that names a class is a class-name
// (7.1.3); however, a typedef-name that names a class shall not
// be used as the identifier in the declarator for a destructor
// declaration.
QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName);
if (const TypedefType *TT = DeclaratorType->getAs<TypedefType>())
Diag(D.getIdentifierLoc(), diag::ext_destructor_typedef_name)
<< DeclaratorType << isa<TypeAliasDecl>(TT->getDecl());
else if (const TemplateSpecializationType *TST =
DeclaratorType->getAs<TemplateSpecializationType>())
if (TST->isTypeAlias())
Diag(D.getIdentifierLoc(), diag::ext_destructor_typedef_name)
<< DeclaratorType << 1;
// C++ [class.dtor]p2:
// A destructor is used to destroy objects of its class type. A
// destructor takes no parameters, and no return type can be
// specified for it (not even void). The address of a destructor
// shall not be taken. A destructor shall not be static. A
// destructor can be invoked for a const, volatile or const
// volatile object. A destructor shall not be declared const,
// volatile or const volatile (9.3.2).
if (SC == SC_Static) {
if (!D.isInvalidType())
Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be)
<< "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
<< SourceRange(D.getIdentifierLoc())
<< FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
SC = SC_None;
}
if (!D.isInvalidType()) {
// Destructors don't have return types, but the parser will
// happily parse something like:
//
// class X {
// float ~X();
// };
//
// The return type will be eliminated later.
if (D.getDeclSpec().hasTypeSpecifier())
Diag(D.getIdentifierLoc(), diag::err_destructor_return_type)
<< SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
<< SourceRange(D.getIdentifierLoc());
else if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) {
diagnoseIgnoredQualifiers(diag::err_destructor_return_type, TypeQuals,
SourceLocation(),
D.getDeclSpec().getConstSpecLoc(),
D.getDeclSpec().getVolatileSpecLoc(),
D.getDeclSpec().getRestrictSpecLoc(),
D.getDeclSpec().getAtomicSpecLoc());
D.setInvalidType();
}
}
checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_destructor);
// C++0x [class.dtor]p2:
// A destructor shall not be declared with a ref-qualifier.
DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
if (FTI.hasRefQualifier()) {
Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_destructor)
<< FTI.RefQualifierIsLValueRef
<< FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
D.setInvalidType();
}
// Make sure we don't have any parameters.
if (FTIHasNonVoidParameters(FTI)) {
Diag(D.getIdentifierLoc(), diag::err_destructor_with_params);
// Delete the parameters.
FTI.freeParams();
D.setInvalidType();
}
// Make sure the destructor isn't variadic.
if (FTI.isVariadic) {
Diag(D.getIdentifierLoc(), diag::err_destructor_variadic);
D.setInvalidType();
}
// Rebuild the function type "R" without any type qualifiers or
// parameters (in case any of the errors above fired) and with
// "void" as the return type, since destructors don't have return
// types.
if (!D.isInvalidType())
return R;
const FunctionProtoType *Proto = R->castAs<FunctionProtoType>();
FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
EPI.Variadic = false;
EPI.TypeQuals = Qualifiers();
EPI.RefQualifier = RQ_None;
return Context.getFunctionType(Context.VoidTy, None, EPI);
}
static void extendLeft(SourceRange &R, SourceRange Before) {
if (Before.isInvalid())
return;
R.setBegin(Before.getBegin());
if (R.getEnd().isInvalid())
R.setEnd(Before.getEnd());
}
static void extendRight(SourceRange &R, SourceRange After) {
if (After.isInvalid())
return;
if (R.getBegin().isInvalid())
R.setBegin(After.getBegin());
R.setEnd(After.getEnd());
}
/// CheckConversionDeclarator - Called by ActOnDeclarator to check the
/// well-formednes of the conversion function declarator @p D with
/// type @p R. If there are any errors in the declarator, this routine
/// will emit diagnostics and return true. Otherwise, it will return
/// false. Either way, the type @p R will be updated to reflect a
/// well-formed type for the conversion operator.
void Sema::CheckConversionDeclarator(Declarator &D, QualType &R,
StorageClass& SC) {
// C++ [class.conv.fct]p1:
// Neither parameter types nor return type can be specified. The
// type of a conversion function (8.3.5) is "function taking no
// parameter returning conversion-type-id."
if (SC == SC_Static) {
if (!D.isInvalidType())
Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member)
<< SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
<< D.getName().getSourceRange();
D.setInvalidType();
SC = SC_None;
}
TypeSourceInfo *ConvTSI = nullptr;
QualType ConvType =
GetTypeFromParser(D.getName().ConversionFunctionId, &ConvTSI);
const DeclSpec &DS = D.getDeclSpec();
if (DS.hasTypeSpecifier() && !D.isInvalidType()) {
// Conversion functions don't have return types, but the parser will
// happily parse something like:
//
// class X {
// float operator bool();
// };
//
// The return type will be changed later anyway.
Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type)
<< SourceRange(DS.getTypeSpecTypeLoc())
<< SourceRange(D.getIdentifierLoc());
D.setInvalidType();
} else if (DS.getTypeQualifiers() && !D.isInvalidType()) {
// It's also plausible that the user writes type qualifiers in the wrong
// place, such as:
// struct S { const operator int(); };
// FIXME: we could provide a fixit to move the qualifiers onto the
// conversion type.
Diag(D.getIdentifierLoc(), diag::err_conv_function_with_complex_decl)
<< SourceRange(D.getIdentifierLoc()) << 0;
D.setInvalidType();
}
const auto *Proto = R->castAs<FunctionProtoType>();
// Make sure we don't have any parameters.
if (Proto->getNumParams() > 0) {
Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params);
// Delete the parameters.
D.getFunctionTypeInfo().freeParams();
D.setInvalidType();
} else if (Proto->isVariadic()) {
Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic);
D.setInvalidType();
}
// Diagnose "&operator bool()" and other such nonsense. This
// is actually a gcc extension which we don't support.
if (Proto->getReturnType() != ConvType) {
bool NeedsTypedef = false;
SourceRange Before, After;
// Walk the chunks and extract information on them for our diagnostic.
bool PastFunctionChunk = false;
for (auto &Chunk : D.type_objects()) {
switch (Chunk.Kind) {
case DeclaratorChunk::Function:
if (!PastFunctionChunk) {
if (Chunk.Fun.HasTrailingReturnType) {
TypeSourceInfo *TRT = nullptr;
GetTypeFromParser(Chunk.Fun.getTrailingReturnType(), &TRT);
if (TRT) extendRight(After, TRT->getTypeLoc().getSourceRange());
}
PastFunctionChunk = true;
break;
}
LLVM_FALLTHROUGH;
case DeclaratorChunk::Array:
NeedsTypedef = true;
extendRight(After, Chunk.getSourceRange());
break;
case DeclaratorChunk::Pointer:
case DeclaratorChunk::BlockPointer:
case DeclaratorChunk::Reference:
case DeclaratorChunk::MemberPointer:
case DeclaratorChunk::Pipe:
extendLeft(Before, Chunk.getSourceRange());
break;
case DeclaratorChunk::Paren:
extendLeft(Before, Chunk.Loc);
extendRight(After, Chunk.EndLoc);
break;
}
}
SourceLocation Loc = Before.isValid() ? Before.getBegin() :
After.isValid() ? After.getBegin() :
D.getIdentifierLoc();
auto &&DB = Diag(Loc, diag::err_conv_function_with_complex_decl);
DB << Before << After;
if (!NeedsTypedef) {
DB << /*don't need a typedef*/0;
// If we can provide a correct fix-it hint, do so.
if (After.isInvalid() && ConvTSI) {
SourceLocation InsertLoc =
getLocForEndOfToken(ConvTSI->getTypeLoc().getEndLoc());
DB << FixItHint::CreateInsertion(InsertLoc, " ")
<< FixItHint::CreateInsertionFromRange(
InsertLoc, CharSourceRange::getTokenRange(Before))
<< FixItHint::CreateRemoval(Before);
}
} else if (!Proto->getReturnType()->isDependentType()) {
DB << /*typedef*/1 << Proto->getReturnType();
} else if (getLangOpts().CPlusPlus11) {
DB << /*alias template*/2 << Proto->getReturnType();
} else {
DB << /*might not be fixable*/3;
}
// Recover by incorporating the other type chunks into the result type.
// Note, this does *not* change the name of the function. This is compatible
// with the GCC extension:
// struct S { &operator int(); } s;
// int &r = s.operator int(); // ok in GCC
// S::operator int&() {} // error in GCC, function name is 'operator int'.
ConvType = Proto->getReturnType();
}
// C++ [class.conv.fct]p4:
// The conversion-type-id shall not represent a function type nor
// an array type.
if (ConvType->isArrayType()) {
Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array);
ConvType = Context.getPointerType(ConvType);
D.setInvalidType();
} else if (ConvType->isFunctionType()) {
Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function);
ConvType = Context.getPointerType(ConvType);
D.setInvalidType();
}
// Rebuild the function type "R" without any parameters (in case any
// of the errors above fired) and with the conversion type as the
// return type.
if (D.isInvalidType())
R = Context.getFunctionType(ConvType, None, Proto->getExtProtoInfo());
// C++0x explicit conversion operators.
if (DS.hasExplicitSpecifier() && !getLangOpts().CPlusPlus20)
Diag(DS.getExplicitSpecLoc(),
getLangOpts().CPlusPlus11
? diag::warn_cxx98_compat_explicit_conversion_functions
: diag::ext_explicit_conversion_functions)
<< SourceRange(DS.getExplicitSpecRange());
}
/// ActOnConversionDeclarator - Called by ActOnDeclarator to complete
/// the declaration of the given C++ conversion function. This routine
/// is responsible for recording the conversion function in the C++
/// class, if possible.
Decl *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
assert(Conversion && "Expected to receive a conversion function declaration");
CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext());
// Make sure we aren't redeclaring the conversion function.
QualType ConvType = Context.getCanonicalType(Conversion->getConversionType());
// C++ [class.conv.fct]p1:
// [...] A conversion function is never used to convert a
// (possibly cv-qualified) object to the (possibly cv-qualified)
// same object type (or a reference to it), to a (possibly
// cv-qualified) base class of that type (or a reference to it),
// or to (possibly cv-qualified) void.
QualType ClassType
= Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
if (const ReferenceType *ConvTypeRef = ConvType->getAs<ReferenceType>())
ConvType = ConvTypeRef->getPointeeType();
if (Conversion->getTemplateSpecializationKind() != TSK_Undeclared &&
Conversion->getTemplateSpecializationKind() != TSK_ExplicitSpecialization)
/* Suppress diagnostics for instantiations. */;
else if (Conversion->size_overridden_methods() != 0)
/* Suppress diagnostics for overriding virtual function in a base class. */;
else if (ConvType->isRecordType()) {
ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType();
if (ConvType == ClassType)
Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
<< ClassType;
else if (IsDerivedFrom(Conversion->getLocation(), ClassType, ConvType))
Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
<< ClassType << ConvType;
} else if (ConvType->isVoidType()) {
Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used)
<< ClassType << ConvType;
}
if (FunctionTemplateDecl *ConversionTemplate
= Conversion->getDescribedFunctionTemplate())
return ConversionTemplate;
return Conversion;
}
namespace {
/// Utility class to accumulate and print a diagnostic listing the invalid
/// specifier(s) on a declaration.
struct BadSpecifierDiagnoser {
BadSpecifierDiagnoser(Sema &S, SourceLocation Loc, unsigned DiagID)
: S(S), Diagnostic(S.Diag(Loc, DiagID)) {}
~BadSpecifierDiagnoser() {
Diagnostic << Specifiers;
}
template<typename T> void check(SourceLocation SpecLoc, T Spec) {
return check(SpecLoc, DeclSpec::getSpecifierName(Spec));
}
void check(SourceLocation SpecLoc, DeclSpec::TST Spec) {
return check(SpecLoc,
DeclSpec::getSpecifierName(Spec, S.getPrintingPolicy()));
}
void check(SourceLocation SpecLoc, const char *Spec) {
if (SpecLoc.isInvalid()) return;
Diagnostic << SourceRange(SpecLoc, SpecLoc);
if (!Specifiers.empty()) Specifiers += " ";
Specifiers += Spec;
}
Sema &S;
Sema::SemaDiagnosticBuilder Diagnostic;
std::string Specifiers;
};
}
/// Check the validity of a declarator that we parsed for a deduction-guide.
/// These aren't actually declarators in the grammar, so we need to check that
/// the user didn't specify any pieces that are not part of the deduction-guide
/// grammar.
void Sema::CheckDeductionGuideDeclarator(Declarator &D, QualType &R,
StorageClass &SC) {
TemplateName GuidedTemplate = D.getName().TemplateName.get().get();
TemplateDecl *GuidedTemplateDecl = GuidedTemplate.getAsTemplateDecl();
assert(GuidedTemplateDecl && "missing template decl for deduction guide");
// C++ [temp.deduct.guide]p3:
// A deduction-gide shall be declared in the same scope as the
// corresponding class template.
if (!CurContext->getRedeclContext()->Equals(
GuidedTemplateDecl->getDeclContext()->getRedeclContext())) {
Diag(D.getIdentifierLoc(), diag::err_deduction_guide_wrong_scope)
<< GuidedTemplateDecl;
Diag(GuidedTemplateDecl->getLocation(), diag::note_template_decl_here);
}
auto &DS = D.getMutableDeclSpec();
// We leave 'friend' and 'virtual' to be rejected in the normal way.
if (DS.hasTypeSpecifier() || DS.getTypeQualifiers() ||
DS.getStorageClassSpecLoc().isValid() || DS.isInlineSpecified() ||
DS.isNoreturnSpecified() || DS.hasConstexprSpecifier()) {
BadSpecifierDiagnoser Diagnoser(
*this, D.getIdentifierLoc(),
diag::err_deduction_guide_invalid_specifier);
Diagnoser.check(DS.getStorageClassSpecLoc(), DS.getStorageClassSpec());
DS.ClearStorageClassSpecs();
SC = SC_None;
// 'explicit' is permitted.
Diagnoser.check(DS.getInlineSpecLoc(), "inline");
Diagnoser.check(DS.getNoreturnSpecLoc(), "_Noreturn");
Diagnoser.check(DS.getConstexprSpecLoc(), "constexpr");
DS.ClearConstexprSpec();
Diagnoser.check(DS.getConstSpecLoc(), "const");
Diagnoser.check(DS.getRestrictSpecLoc(), "__restrict");
Diagnoser.check(DS.getVolatileSpecLoc(), "volatile");
Diagnoser.check(DS.getAtomicSpecLoc(), "_Atomic");
Diagnoser.check(DS.getUnalignedSpecLoc(), "__unaligned");
DS.ClearTypeQualifiers();
Diagnoser.check(DS.getTypeSpecComplexLoc(), DS.getTypeSpecComplex());
Diagnoser.check(DS.getTypeSpecSignLoc(), DS.getTypeSpecSign());
Diagnoser.check(DS.getTypeSpecWidthLoc(), DS.getTypeSpecWidth());
Diagnoser.check(DS.getTypeSpecTypeLoc(), DS.getTypeSpecType());
DS.ClearTypeSpecType();
}
if (D.isInvalidType())
return;
// Check the declarator is simple enough.
bool FoundFunction = false;
for (const DeclaratorChunk &Chunk : llvm::reverse(D.type_objects())) {
if (Chunk.Kind == DeclaratorChunk::Paren)
continue;
if (Chunk.Kind != DeclaratorChunk::Function || FoundFunction) {
Diag(D.getDeclSpec().getBeginLoc(),
diag::err_deduction_guide_with_complex_decl)
<< D.getSourceRange();
break;
}
if (!Chunk.Fun.hasTrailingReturnType()) {
Diag(D.getName().getBeginLoc(),
diag::err_deduction_guide_no_trailing_return_type);
break;
}
// Check that the return type is written as a specialization of
// the template specified as the deduction-guide's name.
ParsedType TrailingReturnType = Chunk.Fun.getTrailingReturnType();
TypeSourceInfo *TSI = nullptr;
QualType RetTy = GetTypeFromParser(TrailingReturnType, &TSI);
assert(TSI && "deduction guide has valid type but invalid return type?");
bool AcceptableReturnType = false;
bool MightInstantiateToSpecialization = false;
if (auto RetTST =
TSI->getTypeLoc().getAs<TemplateSpecializationTypeLoc>()) {
TemplateName SpecifiedName = RetTST.getTypePtr()->getTemplateName();
bool TemplateMatches =
Context.hasSameTemplateName(SpecifiedName, GuidedTemplate);
if (SpecifiedName.getKind() == TemplateName::Template && TemplateMatches)
AcceptableReturnType = true;
else {
// This could still instantiate to the right type, unless we know it
// names the wrong class template.
auto *TD = SpecifiedName.getAsTemplateDecl();
MightInstantiateToSpecialization = !(TD && isa<ClassTemplateDecl>(TD) &&
!TemplateMatches);
}
} else if (!RetTy.hasQualifiers() && RetTy->isDependentType()) {
MightInstantiateToSpecialization = true;
}
if (!AcceptableReturnType) {
Diag(TSI->getTypeLoc().getBeginLoc(),
diag::err_deduction_guide_bad_trailing_return_type)
<< GuidedTemplate << TSI->getType()
<< MightInstantiateToSpecialization
<< TSI->getTypeLoc().getSourceRange();
}
// Keep going to check that we don't have any inner declarator pieces (we
// could still have a function returning a pointer to a function).
FoundFunction = true;
}
if (D.isFunctionDefinition())
Diag(D.getIdentifierLoc(), diag::err_deduction_guide_defines_function);
}
//===----------------------------------------------------------------------===//
// Namespace Handling
//===----------------------------------------------------------------------===//
/// Diagnose a mismatch in 'inline' qualifiers when a namespace is
/// reopened.
static void DiagnoseNamespaceInlineMismatch(Sema &S, SourceLocation KeywordLoc,
SourceLocation Loc,
IdentifierInfo *II, bool *IsInline,
NamespaceDecl *PrevNS) {
assert(*IsInline != PrevNS->isInline());
if (PrevNS->isInline())
// The user probably just forgot the 'inline', so suggest that it
// be added back.
S.Diag(Loc, diag::warn_inline_namespace_reopened_noninline)
<< FixItHint::CreateInsertion(KeywordLoc, "inline ");
else
S.Diag(Loc, diag::err_inline_namespace_mismatch);
S.Diag(PrevNS->getLocation(), diag::note_previous_definition);
*IsInline = PrevNS->isInline();
}
/// ActOnStartNamespaceDef - This is called at the start of a namespace
/// definition.
Decl *Sema::ActOnStartNamespaceDef(
Scope *NamespcScope, SourceLocation InlineLoc, SourceLocation NamespaceLoc,
SourceLocation IdentLoc, IdentifierInfo *II, SourceLocation LBrace,
const ParsedAttributesView &AttrList, UsingDirectiveDecl *&UD) {
SourceLocation StartLoc = InlineLoc.isValid() ? InlineLoc : NamespaceLoc;
// For anonymous namespace, take the location of the left brace.
SourceLocation Loc = II ? IdentLoc : LBrace;
bool IsInline = InlineLoc.isValid();
bool IsInvalid = false;
bool IsStd = false;
bool AddToKnown = false;
Scope *DeclRegionScope = NamespcScope->getParent();
NamespaceDecl *PrevNS = nullptr;
if (II) {
// C++ [namespace.def]p2:
// The identifier in an original-namespace-definition shall not
// have been previously defined in the declarative region in
// which the original-namespace-definition appears. The
// identifier in an original-namespace-definition is the name of
// the namespace. Subsequently in that declarative region, it is
// treated as an original-namespace-name.
//
// Since namespace names are unique in their scope, and we don't
// look through using directives, just look for any ordinary names
// as if by qualified name lookup.
LookupResult R(*this, II, IdentLoc, LookupOrdinaryName,
ForExternalRedeclaration);
LookupQualifiedName(R, CurContext->getRedeclContext());
NamedDecl *PrevDecl =
R.isSingleResult() ? R.getRepresentativeDecl() : nullptr;
PrevNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl);
if (PrevNS) {
// This is an extended namespace definition.
if (IsInline != PrevNS->isInline())
DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, Loc, II,
&IsInline, PrevNS);
} else if (PrevDecl) {
// This is an invalid name redefinition.
Diag(Loc, diag::err_redefinition_different_kind)
<< II;
Diag(PrevDecl->getLocation(), diag::note_previous_definition);
IsInvalid = true;
// Continue on to push Namespc as current DeclContext and return it.
} else if (II->isStr("std") &&
CurContext->getRedeclContext()->isTranslationUnit()) {
// This is the first "real" definition of the namespace "std", so update
// our cache of the "std" namespace to point at this definition.
PrevNS = getStdNamespace();
IsStd = true;
AddToKnown = !IsInline;
} else {
// We've seen this namespace for the first time.
AddToKnown = !IsInline;
}
} else {
// Anonymous namespaces.
// Determine whether the parent already has an anonymous namespace.
DeclContext *Parent = CurContext->getRedeclContext();
if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
PrevNS = TU->getAnonymousNamespace();
} else {
NamespaceDecl *ND = cast<NamespaceDecl>(Parent);
PrevNS = ND->getAnonymousNamespace();
}
if (PrevNS && IsInline != PrevNS->isInline())
DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, NamespaceLoc, II,
&IsInline, PrevNS);
}
NamespaceDecl *Namespc = NamespaceDecl::Create(Context, CurContext, IsInline,
StartLoc, Loc, II, PrevNS);
if (IsInvalid)
Namespc->setInvalidDecl();
ProcessDeclAttributeList(DeclRegionScope, Namespc, AttrList);
AddPragmaAttributes(DeclRegionScope, Namespc);
// FIXME: Should we be merging attributes?
if (const VisibilityAttr *Attr = Namespc->getAttr<VisibilityAttr>())
PushNamespaceVisibilityAttr(Attr, Loc);
if (IsStd)
StdNamespace = Namespc;
if (AddToKnown)
KnownNamespaces[Namespc] = false;
if (II) {
PushOnScopeChains(Namespc, DeclRegionScope);
} else {
// Link the anonymous namespace into its parent.
DeclContext *Parent = CurContext->getRedeclContext();
if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
TU->setAnonymousNamespace(Namespc);
} else {
cast<NamespaceDecl>(Parent)->setAnonymousNamespace(Namespc);
}
CurContext->addDecl(Namespc);
// C++ [namespace.unnamed]p1. An unnamed-namespace-definition
// behaves as if it were replaced by
// namespace unique { /* empty body */ }
// using namespace unique;
// namespace unique { namespace-body }
// where all occurrences of 'unique' in a translation unit are
// replaced by the same identifier and this identifier differs
// from all other identifiers in the entire program.
// We just create the namespace with an empty name and then add an
// implicit using declaration, just like the standard suggests.
//
// CodeGen enforces the "universally unique" aspect by giving all
// declarations semantically contained within an anonymous
// namespace internal linkage.
if (!PrevNS) {
UD = UsingDirectiveDecl::Create(Context, Parent,
/* 'using' */ LBrace,
/* 'namespace' */ SourceLocation(),
/* qualifier */ NestedNameSpecifierLoc(),
/* identifier */ SourceLocation(),
Namespc,
/* Ancestor */ Parent);
UD->setImplicit();
Parent->addDecl(UD);
}
}
ActOnDocumentableDecl(Namespc);
// Although we could have an invalid decl (i.e. the namespace name is a
// redefinition), push it as current DeclContext and try to continue parsing.
// FIXME: We should be able to push Namespc here, so that the each DeclContext
// for the namespace has the declarations that showed up in that particular
// namespace definition.
PushDeclContext(NamespcScope, Namespc);
return Namespc;
}
/// getNamespaceDecl - Returns the namespace a decl represents. If the decl
/// is a namespace alias, returns the namespace it points to.
static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) {
if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D))
return AD->getNamespace();
return dyn_cast_or_null<NamespaceDecl>(D);
}
/// ActOnFinishNamespaceDef - This callback is called after a namespace is
/// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef.
void Sema::ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace) {
NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl);
assert(Namespc && "Invalid parameter, expected NamespaceDecl");
Namespc->setRBraceLoc(RBrace);
PopDeclContext();
if (Namespc->hasAttr<VisibilityAttr>())
PopPragmaVisibility(true, RBrace);
// If this namespace contains an export-declaration, export it now.
if (DeferredExportedNamespaces.erase(Namespc))
Dcl->setModuleOwnershipKind(Decl::ModuleOwnershipKind::VisibleWhenImported);
}
CXXRecordDecl *Sema::getStdBadAlloc() const {
return cast_or_null<CXXRecordDecl>(
StdBadAlloc.get(Context.getExternalSource()));
}
EnumDecl *Sema::getStdAlignValT() const {
return cast_or_null<EnumDecl>(StdAlignValT.get(Context.getExternalSource()));
}
NamespaceDecl *Sema::getStdNamespace() const {
return cast_or_null<NamespaceDecl>(
StdNamespace.get(Context.getExternalSource()));
}
NamespaceDecl *Sema::lookupStdExperimentalNamespace() {
if (!StdExperimentalNamespaceCache) {
if (auto Std = getStdNamespace()) {
LookupResult Result(*this, &PP.getIdentifierTable().get("experimental"),
SourceLocation(), LookupNamespaceName);
if (!LookupQualifiedName(Result, Std) ||
!(StdExperimentalNamespaceCache =
Result.getAsSingle<NamespaceDecl>()))
Result.suppressDiagnostics();
}
}
return StdExperimentalNamespaceCache;
}
namespace {
enum UnsupportedSTLSelect {
USS_InvalidMember,
USS_MissingMember,
USS_NonTrivial,
USS_Other
};
struct InvalidSTLDiagnoser {
Sema &S;
SourceLocation Loc;
QualType TyForDiags;
QualType operator()(UnsupportedSTLSelect Sel = USS_Other, StringRef Name = "",
const VarDecl *VD = nullptr) {
{
auto D = S.Diag(Loc, diag::err_std_compare_type_not_supported)
<< TyForDiags << ((int)Sel);
if (Sel == USS_InvalidMember || Sel == USS_MissingMember) {
assert(!Name.empty());
D << Name;
}
}
if (Sel == USS_InvalidMember) {
S.Diag(VD->getLocation(), diag::note_var_declared_here)
<< VD << VD->getSourceRange();
}
return QualType();
}
};
} // namespace
QualType Sema::CheckComparisonCategoryType(ComparisonCategoryType Kind,
SourceLocation Loc,
ComparisonCategoryUsage Usage) {
assert(getLangOpts().CPlusPlus &&
"Looking for comparison category type outside of C++.");
// Use an elaborated type for diagnostics which has a name containing the
// prepended 'std' namespace but not any inline namespace names.
auto TyForDiags = [&](ComparisonCategoryInfo *Info) {
auto *NNS =
NestedNameSpecifier::Create(Context, nullptr, getStdNamespace());
return Context.getElaboratedType(ETK_None, NNS, Info->getType());
};
// Check if we've already successfully checked the comparison category type
// before. If so, skip checking it again.
ComparisonCategoryInfo *Info = Context.CompCategories.lookupInfo(Kind);
if (Info && FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)]) {
// The only thing we need to check is that the type has a reachable
// definition in the current context.
if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type))
return QualType();
return Info->getType();
}
// If lookup failed
if (!Info) {
std::string NameForDiags = "std::";
NameForDiags += ComparisonCategories::getCategoryString(Kind);
Diag(Loc, diag::err_implied_comparison_category_type_not_found)
<< NameForDiags << (int)Usage;
return QualType();
}
assert(Info->Kind == Kind);
assert(Info->Record);
// Update the Record decl in case we encountered a forward declaration on our
// first pass. FIXME: This is a bit of a hack.
if (Info->Record->hasDefinition())
Info->Record = Info->Record->getDefinition();
if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type))
return QualType();
InvalidSTLDiagnoser UnsupportedSTLError{*this, Loc, TyForDiags(Info)};
if (!Info->Record->isTriviallyCopyable())
return UnsupportedSTLError(USS_NonTrivial);
for (const CXXBaseSpecifier &BaseSpec : Info->Record->bases()) {
CXXRecordDecl *Base = BaseSpec.getType()->getAsCXXRecordDecl();
// Tolerate empty base classes.
if (Base->isEmpty())
continue;
// Reject STL implementations which have at least one non-empty base.
return UnsupportedSTLError();
}
// Check that the STL has implemented the types using a single integer field.
// This expectation allows better codegen for builtin operators. We require:
// (1) The class has exactly one field.
// (2) The field is an integral or enumeration type.
auto FIt = Info->Record->field_begin(), FEnd = Info->Record->field_end();
if (std::distance(FIt, FEnd) != 1 ||
!FIt->getType()->isIntegralOrEnumerationType()) {
return UnsupportedSTLError();
}
// Build each of the require values and store them in Info.
for (ComparisonCategoryResult CCR :
ComparisonCategories::getPossibleResultsForType(Kind)) {
StringRef MemName = ComparisonCategories::getResultString(CCR);
ComparisonCategoryInfo::ValueInfo *ValInfo = Info->lookupValueInfo(CCR);
if (!ValInfo)
return UnsupportedSTLError(USS_MissingMember, MemName);
VarDecl *VD = ValInfo->VD;
assert(VD && "should not be null!");
// Attempt to diagnose reasons why the STL definition of this type
// might be foobar, including it failing to be a constant expression.
// TODO Handle more ways the lookup or result can be invalid.
if (!VD->isStaticDataMember() ||
!VD->isUsableInConstantExpressions(Context))
return UnsupportedSTLError(USS_InvalidMember, MemName, VD);
// Attempt to evaluate the var decl as a constant expression and extract
// the value of its first field as a ICE. If this fails, the STL
// implementation is not supported.
if (!ValInfo->hasValidIntValue())
return UnsupportedSTLError();
MarkVariableReferenced(Loc, VD);
}
// We've successfully built the required types and expressions. Update
// the cache and return the newly cached value.
FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)] = true;
return Info->getType();
}
/// Retrieve the special "std" namespace, which may require us to
/// implicitly define the namespace.
NamespaceDecl *Sema::getOrCreateStdNamespace() {
if (!StdNamespace) {
// The "std" namespace has not yet been defined, so build one implicitly.
StdNamespace = NamespaceDecl::Create(Context,
Context.getTranslationUnitDecl(),
/*Inline=*/false,
SourceLocation(), SourceLocation(),
&PP.getIdentifierTable().get("std"),
/*PrevDecl=*/nullptr);
getStdNamespace()->setImplicit(true);
}
return getStdNamespace();
}
bool Sema::isStdInitializerList(QualType Ty, QualType *Element) {
assert(getLangOpts().CPlusPlus &&
"Looking for std::initializer_list outside of C++.");
// We're looking for implicit instantiations of
// template <typename E> class std::initializer_list.
if (!StdNamespace) // If we haven't seen namespace std yet, this can't be it.
return false;
ClassTemplateDecl *Template = nullptr;
const TemplateArgument *Arguments = nullptr;
if (const RecordType *RT = Ty->getAs<RecordType>()) {
ClassTemplateSpecializationDecl *Specialization =
dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl());
if (!Specialization)
return false;
Template = Specialization->getSpecializedTemplate();
Arguments = Specialization->getTemplateArgs().data();
} else if (const TemplateSpecializationType *TST =
Ty->getAs<TemplateSpecializationType>()) {
Template = dyn_cast_or_null<ClassTemplateDecl>(
TST->getTemplateName().getAsTemplateDecl());
Arguments = TST->getArgs();
}
if (!Template)
return false;
if (!StdInitializerList) {
// Haven't recognized std::initializer_list yet, maybe this is it.
CXXRecordDecl *TemplateClass = Template->getTemplatedDecl();
if (TemplateClass->getIdentifier() !=
&PP.getIdentifierTable().get("initializer_list") ||
!getStdNamespace()->InEnclosingNamespaceSetOf(
TemplateClass->getDeclContext()))
return false;
// This is a template called std::initializer_list, but is it the right
// template?
TemplateParameterList *Params = Template->getTemplateParameters();
if (Params->getMinRequiredArguments() != 1)
return false;
if (!isa<TemplateTypeParmDecl>(Params->getParam(0)))
return false;
// It's the right template.
StdInitializerList = Template;
}
if (Template->getCanonicalDecl() != StdInitializerList->getCanonicalDecl())
return false;
// This is an instance of std::initializer_list. Find the argument type.
if (Element)
*Element = Arguments[0].getAsType();
return true;
}
static ClassTemplateDecl *LookupStdInitializerList(Sema &S, SourceLocation Loc){
NamespaceDecl *Std = S.getStdNamespace();
if (!Std) {
S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
return nullptr;
}
LookupResult Result(S, &S.PP.getIdentifierTable().get("initializer_list"),
Loc, Sema::LookupOrdinaryName);
if (!S.LookupQualifiedName(Result, Std)) {
S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
return nullptr;
}
ClassTemplateDecl *Template = Result.getAsSingle<ClassTemplateDecl>();
if (!Template) {
Result.suppressDiagnostics();
// We found something weird. Complain about the first thing we found.
NamedDecl *Found = *Result.begin();
S.Diag(Found->getLocation(), diag::err_malformed_std_initializer_list);
return nullptr;
}
// We found some template called std::initializer_list. Now verify that it's
// correct.
TemplateParameterList *Params = Template->getTemplateParameters();
if (Params->getMinRequiredArguments() != 1 ||
!isa<TemplateTypeParmDecl>(Params->getParam(0))) {
S.Diag(Template->getLocation(), diag::err_malformed_std_initializer_list);
return nullptr;
}
return Template;
}
QualType Sema::BuildStdInitializerList(QualType Element, SourceLocation Loc) {
if (!StdInitializerList) {
StdInitializerList = LookupStdInitializerList(*this, Loc);
if (!StdInitializerList)
return QualType();
}
TemplateArgumentListInfo Args(Loc, Loc);
Args.addArgument(TemplateArgumentLoc(TemplateArgument(Element),
Context.getTrivialTypeSourceInfo(Element,
Loc)));
return Context.getCanonicalType(
CheckTemplateIdType(TemplateName(StdInitializerList), Loc, Args));
}
bool Sema::isInitListConstructor(const FunctionDecl *Ctor) {
// C++ [dcl.init.list]p2:
// A constructor is an initializer-list constructor if its first parameter
// is of type std::initializer_list<E> or reference to possibly cv-qualified
// std::initializer_list<E> for some type E, and either there are no other
// parameters or else all other parameters have default arguments.
if (!Ctor->hasOneParamOrDefaultArgs())
return false;
QualType ArgType = Ctor->getParamDecl(0)->getType();
if (const ReferenceType *RT = ArgType->getAs<ReferenceType>())
ArgType = RT->getPointeeType().getUnqualifiedType();
return isStdInitializerList(ArgType, nullptr);
}
/// Determine whether a using statement is in a context where it will be
/// apply in all contexts.
static bool IsUsingDirectiveInToplevelContext(DeclContext *CurContext) {
switch (CurContext->getDeclKind()) {
case Decl::TranslationUnit:
return true;
case Decl::LinkageSpec:
return IsUsingDirectiveInToplevelContext(CurContext->getParent());
default:
return false;
}
}
namespace {
// Callback to only accept typo corrections that are namespaces.
class NamespaceValidatorCCC final : public CorrectionCandidateCallback {
public:
bool ValidateCandidate(const TypoCorrection &candidate) override {
if (NamedDecl *ND = candidate.getCorrectionDecl())
return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND);
return false;
}
std::unique_ptr<CorrectionCandidateCallback> clone() override {
return std::make_unique<NamespaceValidatorCCC>(*this);
}
};
}
static bool TryNamespaceTypoCorrection(Sema &S, LookupResult &R, Scope *Sc,
CXXScopeSpec &SS,
SourceLocation IdentLoc,
IdentifierInfo *Ident) {
R.clear();
NamespaceValidatorCCC CCC{};
if (TypoCorrection Corrected =
S.CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), Sc, &SS, CCC,
Sema::CTK_ErrorRecovery)) {
if (DeclContext *DC = S.computeDeclContext(SS, false)) {
std::string CorrectedStr(Corrected.getAsString(S.getLangOpts()));
bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
Ident->getName().equals(CorrectedStr);
S.diagnoseTypo(Corrected,
S.PDiag(diag::err_using_directive_member_suggest)
<< Ident << DC << DroppedSpecifier << SS.getRange(),
S.PDiag(diag::note_namespace_defined_here));
} else {
S.diagnoseTypo(Corrected,
S.PDiag(diag::err_using_directive_suggest) << Ident,
S.PDiag(diag::note_namespace_defined_here));
}
R.addDecl(Corrected.getFoundDecl());
return true;
}
return false;
}
Decl *Sema::ActOnUsingDirective(Scope *S, SourceLocation UsingLoc,
SourceLocation NamespcLoc, CXXScopeSpec &SS,
SourceLocation IdentLoc,
IdentifierInfo *NamespcName,
const ParsedAttributesView &AttrList) {
assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
assert(NamespcName && "Invalid NamespcName.");
assert(IdentLoc.isValid() && "Invalid NamespceName location.");
// This can only happen along a recovery path.
while (S->isTemplateParamScope())
S = S->getParent();
assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
UsingDirectiveDecl *UDir = nullptr;
NestedNameSpecifier *Qualifier = nullptr;
if (SS.isSet())
Qualifier = SS.getScopeRep();
// Lookup namespace name.
LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName);
LookupParsedName(R, S, &SS);
if (R.isAmbiguous())
return nullptr;
if (R.empty()) {
R.clear();
// Allow "using namespace std;" or "using namespace ::std;" even if
// "std" hasn't been defined yet, for GCC compatibility.
if ((!Qualifier || Qualifier->getKind() == NestedNameSpecifier::Global) &&
NamespcName->isStr("std")) {
Diag(IdentLoc, diag::ext_using_undefined_std);
R.addDecl(getOrCreateStdNamespace());
R.resolveKind();
}
// Otherwise, attempt typo correction.
else TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, NamespcName);
}
if (!R.empty()) {
NamedDecl *Named = R.getRepresentativeDecl();
NamespaceDecl *NS = R.getAsSingle<NamespaceDecl>();
assert(NS && "expected namespace decl");
// The use of a nested name specifier may trigger deprecation warnings.
DiagnoseUseOfDecl(Named, IdentLoc);
// C++ [namespace.udir]p1:
// A using-directive specifies that the names in the nominated
// namespace can be used in the scope in which the
// using-directive appears after the using-directive. During
// unqualified name lookup (3.4.1), the names appear as if they
// were declared in the nearest enclosing namespace which
// contains both the using-directive and the nominated
// namespace. [Note: in this context, "contains" means "contains
// directly or indirectly". ]
// Find enclosing context containing both using-directive and
// nominated namespace.
DeclContext *CommonAncestor = NS;
while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
CommonAncestor = CommonAncestor->getParent();
UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc,
SS.getWithLocInContext(Context),
IdentLoc, Named, CommonAncestor);
if (IsUsingDirectiveInToplevelContext(CurContext) &&
!SourceMgr.isInMainFile(SourceMgr.getExpansionLoc(IdentLoc))) {
Diag(IdentLoc, diag::warn_using_directive_in_header);
}
PushUsingDirective(S, UDir);
} else {
Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
}
if (UDir)
ProcessDeclAttributeList(S, UDir, AttrList);
return UDir;
}
void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) {
// If the scope has an associated entity and the using directive is at
// namespace or translation unit scope, add the UsingDirectiveDecl into
// its lookup structure so qualified name lookup can find it.
DeclContext *Ctx = S->getEntity();
if (Ctx && !Ctx->isFunctionOrMethod())
Ctx->addDecl(UDir);
else
// Otherwise, it is at block scope. The using-directives will affect lookup
// only to the end of the scope.
S->PushUsingDirective(UDir);
}
Decl *Sema::ActOnUsingDeclaration(Scope *S, AccessSpecifier AS,
SourceLocation UsingLoc,
SourceLocation TypenameLoc, CXXScopeSpec &SS,
UnqualifiedId &Name,
SourceLocation EllipsisLoc,
const ParsedAttributesView &AttrList) {
assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
if (SS.isEmpty()) {
Diag(Name.getBeginLoc(), diag::err_using_requires_qualname);
return nullptr;
}
switch (Name.getKind()) {
case UnqualifiedIdKind::IK_ImplicitSelfParam:
case UnqualifiedIdKind::IK_Identifier:
case UnqualifiedIdKind::IK_OperatorFunctionId:
case UnqualifiedIdKind::IK_LiteralOperatorId:
case UnqualifiedIdKind::IK_ConversionFunctionId:
break;
case UnqualifiedIdKind::IK_ConstructorName:
case UnqualifiedIdKind::IK_ConstructorTemplateId:
// C++11 inheriting constructors.
Diag(Name.getBeginLoc(),
getLangOpts().CPlusPlus11
? diag::warn_cxx98_compat_using_decl_constructor
: diag::err_using_decl_constructor)
<< SS.getRange();
if (getLangOpts().CPlusPlus11) break;
return nullptr;
case UnqualifiedIdKind::IK_DestructorName:
Diag(Name.getBeginLoc(), diag::err_using_decl_destructor) << SS.getRange();
return nullptr;
case UnqualifiedIdKind::IK_TemplateId:
Diag(Name.getBeginLoc(), diag::err_using_decl_template_id)
<< SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc);
return nullptr;
case UnqualifiedIdKind::IK_DeductionGuideName:
llvm_unreachable("cannot parse qualified deduction guide name");
}
DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);
DeclarationName TargetName = TargetNameInfo.getName();
if (!TargetName)
return nullptr;
// Warn about access declarations.
if (UsingLoc.isInvalid()) {
Diag(Name.getBeginLoc(), getLangOpts().CPlusPlus11
? diag::err_access_decl
: diag::warn_access_decl_deprecated)
<< FixItHint::CreateInsertion(SS.getRange().getBegin(), "using ");
}
if (EllipsisLoc.isInvalid()) {
if (DiagnoseUnexpandedParameterPack(SS, UPPC_UsingDeclaration) ||
DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC_UsingDeclaration))
return nullptr;
} else {
if (!SS.getScopeRep()->containsUnexpandedParameterPack() &&
!TargetNameInfo.containsUnexpandedParameterPack()) {
Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
<< SourceRange(SS.getBeginLoc(), TargetNameInfo.getEndLoc());
EllipsisLoc = SourceLocation();
}
}
NamedDecl *UD =
BuildUsingDeclaration(S, AS, UsingLoc, TypenameLoc.isValid(), TypenameLoc,
SS, TargetNameInfo, EllipsisLoc, AttrList,
/*IsInstantiation*/ false,
AttrList.hasAttribute(ParsedAttr::AT_UsingIfExists));
if (UD)
PushOnScopeChains(UD, S, /*AddToContext*/ false);
return UD;
}
Decl *Sema::ActOnUsingEnumDeclaration(Scope *S, AccessSpecifier AS,
SourceLocation UsingLoc,
SourceLocation EnumLoc,
const DeclSpec &DS) {
switch (DS.getTypeSpecType()) {
case DeclSpec::TST_error:
// This will already have been diagnosed
return nullptr;
case DeclSpec::TST_enum:
break;
case DeclSpec::TST_typename:
Diag(DS.getTypeSpecTypeLoc(), diag::err_using_enum_is_dependent);
return nullptr;
default:
llvm_unreachable("unexpected DeclSpec type");
}
// As with enum-decls, we ignore attributes for now.
auto *Enum = cast<EnumDecl>(DS.getRepAsDecl());
if (auto *Def = Enum->getDefinition())
Enum = Def;
auto *UD = BuildUsingEnumDeclaration(S, AS, UsingLoc, EnumLoc,
DS.getTypeSpecTypeNameLoc(), Enum);
if (UD)
PushOnScopeChains(UD, S, /*AddToContext*/ false);
return UD;
}
/// Determine whether a using declaration considers the given
/// declarations as "equivalent", e.g., if they are redeclarations of
/// the same entity or are both typedefs of the same type.
static bool
IsEquivalentForUsingDecl(ASTContext &Context, NamedDecl *D1, NamedDecl *D2) {
if (D1->getCanonicalDecl() == D2->getCanonicalDecl())
return true;
if (TypedefNameDecl *TD1 = dyn_cast<TypedefNameDecl>(D1))
if (TypedefNameDecl *TD2 = dyn_cast<TypedefNameDecl>(D2))
return Context.hasSameType(TD1->getUnderlyingType(),
TD2->getUnderlyingType());
// Two using_if_exists using-declarations are equivalent if both are
// unresolved.
if (isa<UnresolvedUsingIfExistsDecl>(D1) &&
isa<UnresolvedUsingIfExistsDecl>(D2))
return true;
return false;
}
/// Determines whether to create a using shadow decl for a particular
/// decl, given the set of decls existing prior to this using lookup.
bool Sema::CheckUsingShadowDecl(BaseUsingDecl *BUD, NamedDecl *Orig,
const LookupResult &Previous,
UsingShadowDecl *&PrevShadow) {
// Diagnose finding a decl which is not from a base class of the
// current class. We do this now because there are cases where this
// function will silently decide not to build a shadow decl, which
// will pre-empt further diagnostics.
//
// We don't need to do this in C++11 because we do the check once on
// the qualifier.
//
// FIXME: diagnose the following if we care enough:
// struct A { int foo; };
// struct B : A { using A::foo; };
// template <class T> struct C : A {};
// template <class T> struct D : C<T> { using B::foo; } // <---
// This is invalid (during instantiation) in C++03 because B::foo
// resolves to the using decl in B, which is not a base class of D<T>.
// We can't diagnose it immediately because C<T> is an unknown
// specialization. The UsingShadowDecl in D<T> then points directly
// to A::foo, which will look well-formed when we instantiate.
// The right solution is to not collapse the shadow-decl chain.
if (!getLangOpts().CPlusPlus11 && CurContext->isRecord())
if (auto *Using = dyn_cast<UsingDecl>(BUD)) {
DeclContext *OrigDC = Orig->getDeclContext();
// Handle enums and anonymous structs.
if (isa<EnumDecl>(OrigDC))
OrigDC = OrigDC->getParent();
CXXRecordDecl *OrigRec = cast<CXXRecordDecl>(OrigDC);
while (OrigRec->isAnonymousStructOrUnion())
OrigRec = cast<CXXRecordDecl>(OrigRec->getDeclContext());
if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(OrigRec)) {
if (OrigDC == CurContext) {
Diag(Using->getLocation(),
diag::err_using_decl_nested_name_specifier_is_current_class)
<< Using->getQualifierLoc().getSourceRange();
Diag(Orig->getLocation(), diag::note_using_decl_target);
Using->setInvalidDecl();
return true;
}
Diag(Using->getQualifierLoc().getBeginLoc(),
diag::err_using_decl_nested_name_specifier_is_not_base_class)
<< Using->getQualifier() << cast<CXXRecordDecl>(CurContext)
<< Using->getQualifierLoc().getSourceRange();
Diag(Orig->getLocation(), diag::note_using_decl_target);
Using->setInvalidDecl();
return true;
}
}
if (Previous.empty()) return false;
NamedDecl *Target = Orig;
if (isa<UsingShadowDecl>(Target))
Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
// If the target happens to be one of the previous declarations, we
// don't have a conflict.
//
// FIXME: but we might be increasing its access, in which case we
// should redeclare it.
NamedDecl *NonTag = nullptr, *Tag = nullptr;
bool FoundEquivalentDecl = false;
for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
I != E; ++I) {
NamedDecl *D = (*I)->getUnderlyingDecl();
// We can have UsingDecls in our Previous results because we use the same
// LookupResult for checking whether the UsingDecl itself is a valid
// redeclaration.
if (isa<UsingDecl>(D) || isa<UsingPackDecl>(D) || isa<UsingEnumDecl>(D))
continue;
if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
// C++ [class.mem]p19:
// If T is the name of a class, then [every named member other than
// a non-static data member] shall have a name different from T
if (RD->isInjectedClassName() && !isa<FieldDecl>(Target) &&
!isa<IndirectFieldDecl>(Target) &&
!isa<UnresolvedUsingValueDecl>(Target) &&
DiagnoseClassNameShadow(
CurContext,
DeclarationNameInfo(BUD->getDeclName(), BUD->getLocation())))
return true;
}
if (IsEquivalentForUsingDecl(Context, D, Target)) {
if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(*I))
PrevShadow = Shadow;
FoundEquivalentDecl = true;
} else if (isEquivalentInternalLinkageDeclaration(D, Target)) {
// We don't conflict with an existing using shadow decl of an equivalent
// declaration, but we're not a redeclaration of it.
FoundEquivalentDecl = true;
}
if (isVisible(D))
(isa<TagDecl>(D) ? Tag : NonTag) = D;
}
if (FoundEquivalentDecl)
return false;
// Always emit a diagnostic for a mismatch between an unresolved
// using_if_exists and a resolved using declaration in either direction.
if (isa<UnresolvedUsingIfExistsDecl>(Target) !=
(isa_and_nonnull<UnresolvedUsingIfExistsDecl>(NonTag))) {
if (!NonTag && !Tag)
return false;
Diag(BUD->getLocation(), diag::err_using_decl_conflict);
Diag(Target->getLocation(), diag::note_using_decl_target);
Diag((NonTag ? NonTag : Tag)->getLocation(),
diag::note_using_decl_conflict);
BUD->setInvalidDecl();
return true;
}
if (FunctionDecl *FD = Target->getAsFunction()) {
NamedDecl *OldDecl = nullptr;
switch (CheckOverload(nullptr, FD, Previous, OldDecl,
/*IsForUsingDecl*/ true)) {
case Ovl_Overload:
return false;
case Ovl_NonFunction:
Diag(BUD->getLocation(), diag::err_using_decl_conflict);
break;
// We found a decl with the exact signature.
case Ovl_Match:
// If we're in a record, we want to hide the target, so we
// return true (without a diagnostic) to tell the caller not to
// build a shadow decl.
if (CurContext->isRecord())
return true;
// If we're not in a record, this is an error.
Diag(BUD->getLocation(), diag::err_using_decl_conflict);
break;
}
Diag(Target->getLocation(), diag::note_using_decl_target);
Diag(OldDecl->getLocation(), diag::note_using_decl_conflict);
BUD->setInvalidDecl();
return true;
}
// Target is not a function.
if (isa<TagDecl>(Target)) {
// No conflict between a tag and a non-tag.
if (!Tag) return false;
Diag(BUD->getLocation(), diag::err_using_decl_conflict);
Diag(Target->getLocation(), diag::note_using_decl_target);
Diag(Tag->getLocation(), diag::note_using_decl_conflict);
BUD->setInvalidDecl();
return true;
}
// No conflict between a tag and a non-tag.
if (!NonTag) return false;
Diag(BUD->getLocation(), diag::err_using_decl_conflict);
Diag(Target->getLocation(), diag::note_using_decl_target);
Diag(NonTag->getLocation(), diag::note_using_decl_conflict);
BUD->setInvalidDecl();
return true;
}
/// Determine whether a direct base class is a virtual base class.
static bool isVirtualDirectBase(CXXRecordDecl *Derived, CXXRecordDecl *Base) {
if (!Derived->getNumVBases())
return false;
for (auto &B : Derived->bases())
if (B.getType()->getAsCXXRecordDecl() == Base)
return B.isVirtual();
llvm_unreachable("not a direct base class");
}
/// Builds a shadow declaration corresponding to a 'using' declaration.
UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S, BaseUsingDecl *BUD,
NamedDecl *Orig,
UsingShadowDecl *PrevDecl) {
// If we resolved to another shadow declaration, just coalesce them.
NamedDecl *Target = Orig;
if (isa<UsingShadowDecl>(Target)) {
Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
assert(!isa<UsingShadowDecl>(Target) && "nested shadow declaration");
}
NamedDecl *NonTemplateTarget = Target;
if (auto *TargetTD = dyn_cast<TemplateDecl>(Target))
NonTemplateTarget = TargetTD->getTemplatedDecl();
UsingShadowDecl *Shadow;
if (NonTemplateTarget && isa<CXXConstructorDecl>(NonTemplateTarget)) {
UsingDecl *Using = cast<UsingDecl>(BUD);
bool IsVirtualBase =
isVirtualDirectBase(cast<CXXRecordDecl>(CurContext),
Using->getQualifier()->getAsRecordDecl());
Shadow = ConstructorUsingShadowDecl::Create(
Context, CurContext, Using->getLocation(), Using, Orig, IsVirtualBase);
} else {
Shadow = UsingShadowDecl::Create(Context, CurContext, BUD->getLocation(),
Target->getDeclName(), BUD, Target);
}
BUD->addShadowDecl(Shadow);
Shadow->setAccess(BUD->getAccess());
if (Orig->isInvalidDecl() || BUD->isInvalidDecl())
Shadow->setInvalidDecl();
Shadow->setPreviousDecl(PrevDecl);
if (S)
PushOnScopeChains(Shadow, S);
else
CurContext->addDecl(Shadow);
return Shadow;
}
/// Hides a using shadow declaration. This is required by the current
/// using-decl implementation when a resolvable using declaration in a
/// class is followed by a declaration which would hide or override
/// one or more of the using decl's targets; for example:
///
/// struct Base { void foo(int); };
/// struct Derived : Base {
/// using Base::foo;
/// void foo(int);
/// };
///
/// The governing language is C++03 [namespace.udecl]p12:
///
/// When a using-declaration brings names from a base class into a
/// derived class scope, member functions in the derived class
/// override and/or hide member functions with the same name and
/// parameter types in a base class (rather than conflicting).
///
/// There are two ways to implement this:
/// (1) optimistically create shadow decls when they're not hidden
/// by existing declarations, or
/// (2) don't create any shadow decls (or at least don't make them
/// visible) until we've fully parsed/instantiated the class.
/// The problem with (1) is that we might have to retroactively remove
/// a shadow decl, which requires several O(n) operations because the
/// decl structures are (very reasonably) not designed for removal.
/// (2) avoids this but is very fiddly and phase-dependent.
void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) {
if (Shadow->getDeclName().getNameKind() ==
DeclarationName::CXXConversionFunctionName)
cast<CXXRecordDecl>(Shadow->getDeclContext())->removeConversion(Shadow);
// Remove it from the DeclContext...
Shadow->getDeclContext()->removeDecl(Shadow);
// ...and the scope, if applicable...
if (S) {
S->RemoveDecl(Shadow);
IdResolver.RemoveDecl(Shadow);
}
// ...and the using decl.
Shadow->getIntroducer()->removeShadowDecl(Shadow);
// TODO: complain somehow if Shadow was used. It shouldn't
// be possible for this to happen, because...?
}
/// Find the base specifier for a base class with the given type.
static CXXBaseSpecifier *findDirectBaseWithType(CXXRecordDecl *Derived,
QualType DesiredBase,
bool &AnyDependentBases) {
// Check whether the named type is a direct base class.
CanQualType CanonicalDesiredBase = DesiredBase->getCanonicalTypeUnqualified()
.getUnqualifiedType();
for (auto &Base : Derived->bases()) {
CanQualType BaseType = Base.getType()->getCanonicalTypeUnqualified();
if (CanonicalDesiredBase == BaseType)
return &Base;
if (BaseType->isDependentType())
AnyDependentBases = true;
}
return nullptr;
}
namespace {
class UsingValidatorCCC final : public CorrectionCandidateCallback {
public:
UsingValidatorCCC(bool HasTypenameKeyword, bool IsInstantiation,
NestedNameSpecifier *NNS, CXXRecordDecl *RequireMemberOf)
: HasTypenameKeyword(HasTypenameKeyword),
IsInstantiation(IsInstantiation), OldNNS(NNS),
RequireMemberOf(RequireMemberOf) {}
bool ValidateCandidate(const TypoCorrection &Candidate) override {
NamedDecl *ND = Candidate.getCorrectionDecl();
// Keywords are not valid here.
if (!ND || isa<NamespaceDecl>(ND))
return false;
// Completely unqualified names are invalid for a 'using' declaration.
if (Candidate.WillReplaceSpecifier() && !Candidate.getCorrectionSpecifier())
return false;
// FIXME: Don't correct to a name that CheckUsingDeclRedeclaration would
// reject.
if (RequireMemberOf) {
auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND);
if (FoundRecord && FoundRecord->isInjectedClassName()) {
// No-one ever wants a using-declaration to name an injected-class-name
// of a base class, unless they're declaring an inheriting constructor.
ASTContext &Ctx = ND->getASTContext();
if (!Ctx.getLangOpts().CPlusPlus11)
return false;
QualType FoundType = Ctx.getRecordType(FoundRecord);
// Check that the injected-class-name is named as a member of its own
// type; we don't want to suggest 'using Derived::Base;', since that
// means something else.
NestedNameSpecifier *Specifier =
Candidate.WillReplaceSpecifier()
? Candidate.getCorrectionSpecifier()
: OldNNS;
if (!Specifier->getAsType() ||
!Ctx.hasSameType(QualType(Specifier->getAsType(), 0), FoundType))
return false;
// Check that this inheriting constructor declaration actually names a
// direct base class of the current class.
bool AnyDependentBases = false;
if (!findDirectBaseWithType(RequireMemberOf,
Ctx.getRecordType(FoundRecord),
AnyDependentBases) &&
!AnyDependentBases)
return false;
} else {
auto *RD = dyn_cast<CXXRecordDecl>(ND->getDeclContext());
if (!RD || RequireMemberOf->isProvablyNotDerivedFrom(RD))
return false;
// FIXME: Check that the base class member is accessible?
}
} else {
auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND);
if (FoundRecord && FoundRecord->isInjectedClassName())
return false;
}
if (isa<TypeDecl>(ND))
return HasTypenameKeyword || !IsInstantiation;
return !HasTypenameKeyword;
}
std::unique_ptr<CorrectionCandidateCallback> clone() override {
return std::make_unique<UsingValidatorCCC>(*this);
}
private:
bool HasTypenameKeyword;
bool IsInstantiation;
NestedNameSpecifier *OldNNS;
CXXRecordDecl *RequireMemberOf;
};
} // end anonymous namespace
/// Remove decls we can't actually see from a lookup being used to declare
/// shadow using decls.
///
/// \param S - The scope of the potential shadow decl
/// \param Previous - The lookup of a potential shadow decl's name.
void Sema::FilterUsingLookup(Scope *S, LookupResult &Previous) {
// It is really dumb that we have to do this.
LookupResult::Filter F = Previous.makeFilter();
while (F.hasNext()) {
NamedDecl *D = F.next();
if (!isDeclInScope(D, CurContext, S))
F.erase();
// If we found a local extern declaration that's not ordinarily visible,
// and this declaration is being added to a non-block scope, ignore it.
// We're only checking for scope conflicts here, not also for violations
// of the linkage rules.
else if (!CurContext->isFunctionOrMethod() && D->isLocalExternDecl() &&
!(D->getIdentifierNamespace() & Decl::IDNS_Ordinary))
F.erase();
}
F.done();
}
/// Builds a using declaration.
///
/// \param IsInstantiation - Whether this call arises from an
/// instantiation of an unresolved using declaration. We treat
/// the lookup differently for these declarations.
NamedDecl *Sema::BuildUsingDeclaration(
Scope *S, AccessSpecifier AS, SourceLocation UsingLoc,
bool HasTypenameKeyword, SourceLocation TypenameLoc, CXXScopeSpec &SS,
DeclarationNameInfo NameInfo, SourceLocation EllipsisLoc,
const ParsedAttributesView &AttrList, bool IsInstantiation,
bool IsUsingIfExists) {
assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
SourceLocation IdentLoc = NameInfo.getLoc();
assert(IdentLoc.isValid() && "Invalid TargetName location.");
// FIXME: We ignore attributes for now.
// For an inheriting constructor declaration, the name of the using
// declaration is the name of a constructor in this class, not in the
// base class.
DeclarationNameInfo UsingName = NameInfo;
if (UsingName.getName().getNameKind() == DeclarationName::CXXConstructorName)
if (auto *RD = dyn_cast<CXXRecordDecl>(CurContext))
UsingName.setName(Context.DeclarationNames.getCXXConstructorName(
Context.getCanonicalType(Context.getRecordType(RD))));
// Do the redeclaration lookup in the current scope.
LookupResult Previous(*this, UsingName, LookupUsingDeclName,
ForVisibleRedeclaration);
Previous.setHideTags(false);
if (S) {
LookupName(Previous, S);
FilterUsingLookup(S, Previous);
} else {
assert(IsInstantiation && "no scope in non-instantiation");
if (CurContext->isRecord())
LookupQualifiedName(Previous, CurContext);
else {
// No redeclaration check is needed here; in non-member contexts we
// diagnosed all possible conflicts with other using-declarations when
// building the template:
//
// For a dependent non-type using declaration, the only valid case is
// if we instantiate to a single enumerator. We check for conflicts
// between shadow declarations we introduce, and we check in the template
// definition for conflicts between a non-type using declaration and any
// other declaration, which together covers all cases.
//
// A dependent typename using declaration will never successfully
// instantiate, since it will always name a class member, so we reject
// that in the template definition.
}
}
// Check for invalid redeclarations.
if (CheckUsingDeclRedeclaration(UsingLoc, HasTypenameKeyword,
SS, IdentLoc, Previous))
return nullptr;
// 'using_if_exists' doesn't make sense on an inherited constructor.
if (IsUsingIfExists && UsingName.getName().getNameKind() ==
DeclarationName::CXXConstructorName) {
Diag(UsingLoc, diag::err_using_if_exists_on_ctor);
return nullptr;
}
DeclContext *LookupContext = computeDeclContext(SS);
NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
if (!LookupContext || EllipsisLoc.isValid()) {
NamedDecl *D;
// Dependent scope, or an unexpanded pack
if (!LookupContext && CheckUsingDeclQualifier(UsingLoc, HasTypenameKeyword,
SS, NameInfo, IdentLoc))
return nullptr;
if (HasTypenameKeyword) {
// FIXME: not all declaration name kinds are legal here
D = UnresolvedUsingTypenameDecl::Create(Context, CurContext,
UsingLoc, TypenameLoc,
QualifierLoc,
IdentLoc, NameInfo.getName(),
EllipsisLoc);
} else {
D = UnresolvedUsingValueDecl::Create(Context, CurContext, UsingLoc,
QualifierLoc, NameInfo, EllipsisLoc);
}
D->setAccess(AS);
CurContext->addDecl(D);
ProcessDeclAttributeList(S, D, AttrList);
return D;
}
auto Build = [&](bool Invalid) {
UsingDecl *UD =
UsingDecl::Create(Context, CurContext, UsingLoc, QualifierLoc,
UsingName, HasTypenameKeyword);
UD->setAccess(AS);
CurContext->addDecl(UD);
ProcessDeclAttributeList(S, UD, AttrList);
UD->setInvalidDecl(Invalid);
return UD;
};
auto BuildInvalid = [&]{ return Build(true); };
auto BuildValid = [&]{ return Build(false); };
if (RequireCompleteDeclContext(SS, LookupContext))
return BuildInvalid();
// Look up the target name.
LookupResult R(*this, NameInfo, LookupOrdinaryName);
// Unlike most lookups, we don't always want to hide tag
// declarations: tag names are visible through the using declaration
// even if hidden by ordinary names, *except* in a dependent context
// where they may be used by two-phase lookup.
if (!IsInstantiation)
R.setHideTags(false);
// For the purposes of this lookup, we have a base object type
// equal to that of the current context.
if (CurContext->isRecord()) {
R.setBaseObjectType(
Context.getTypeDeclType(cast<CXXRecordDecl>(CurContext)));
}
LookupQualifiedName(R, LookupContext);
// Validate the context, now we have a lookup
if (CheckUsingDeclQualifier(UsingLoc, HasTypenameKeyword, SS, NameInfo,
IdentLoc, &R))
return nullptr;
if (R.empty() && IsUsingIfExists)
R.addDecl(UnresolvedUsingIfExistsDecl::Create(Context, CurContext, UsingLoc,
UsingName.getName()),
AS_public);
// Try to correct typos if possible. If constructor name lookup finds no
// results, that means the named class has no explicit constructors, and we
// suppressed declaring implicit ones (probably because it's dependent or
// invalid).
if (R.empty() &&
NameInfo.getName().getNameKind() != DeclarationName::CXXConstructorName) {
// HACK 2017-01-08: Work around an issue with libstdc++'s detection of
// ::gets. Sometimes it believes that glibc provides a ::gets in cases where
// it does not. The issue was fixed in libstdc++ 6.3 (2016-12-21) and later.
auto *II = NameInfo.getName().getAsIdentifierInfo();
if (getLangOpts().CPlusPlus14 && II && II->isStr("gets") &&
CurContext->isStdNamespace() &&
isa<TranslationUnitDecl>(LookupContext) &&
getSourceManager().isInSystemHeader(UsingLoc))
return nullptr;
UsingValidatorCCC CCC(HasTypenameKeyword, IsInstantiation, SS.getScopeRep(),
dyn_cast<CXXRecordDecl>(CurContext));
if (TypoCorrection Corrected =
CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS, CCC,
CTK_ErrorRecovery)) {
// We reject candidates where DroppedSpecifier == true, hence the
// literal '0' below.
diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest)
<< NameInfo.getName() << LookupContext << 0
<< SS.getRange());
// If we picked a correction with no attached Decl we can't do anything
// useful with it, bail out.
NamedDecl *ND = Corrected.getCorrectionDecl();
if (!ND)
return BuildInvalid();
// If we corrected to an inheriting constructor, handle it as one.
auto *RD = dyn_cast<CXXRecordDecl>(ND);
if (RD && RD->isInjectedClassName()) {
// The parent of the injected class name is the class itself.
RD = cast<CXXRecordDecl>(RD->getParent());
// Fix up the information we'll use to build the using declaration.
if (Corrected.WillReplaceSpecifier()) {
NestedNameSpecifierLocBuilder Builder;
Builder.MakeTrivial(Context, Corrected.getCorrectionSpecifier(),
QualifierLoc.getSourceRange());
QualifierLoc = Builder.getWithLocInContext(Context);
}
// In this case, the name we introduce is the name of a derived class
// constructor.
auto *CurClass = cast<CXXRecordDecl>(CurContext);
UsingName.setName(Context.DeclarationNames.getCXXConstructorName(
Context.getCanonicalType(Context.getRecordType(CurClass))));
UsingName.setNamedTypeInfo(nullptr);
for (auto *Ctor : LookupConstructors(RD))
R.addDecl(Ctor);
R.resolveKind();
} else {
// FIXME: Pick up all the declarations if we found an overloaded
// function.
UsingName.setName(ND->getDeclName());
R.addDecl(ND);
}
} else {
Diag(IdentLoc, diag::err_no_member)
<< NameInfo.getName() << LookupContext << SS.getRange();
return BuildInvalid();
}
}
if (R.isAmbiguous())
return BuildInvalid();
if (HasTypenameKeyword) {
// If we asked for a typename and got a non-type decl, error out.
if (!R.getAsSingle<TypeDecl>() &&
!R.getAsSingle<UnresolvedUsingIfExistsDecl>()) {
Diag(IdentLoc, diag::err_using_typename_non_type);
for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
Diag((*I)->getUnderlyingDecl()->getLocation(),
diag::note_using_decl_target);
return BuildInvalid();
}
} else {
// If we asked for a non-typename and we got a type, error out,
// but only if this is an instantiation of an unresolved using
// decl. Otherwise just silently find the type name.
if (IsInstantiation && R.getAsSingle<TypeDecl>()) {
Diag(IdentLoc, diag::err_using_dependent_value_is_type);
Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target);
return BuildInvalid();
}
}
// C++14 [namespace.udecl]p6:
// A using-declaration shall not name a namespace.
if (R.getAsSingle<NamespaceDecl>()) {
Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace)
<< SS.getRange();
return BuildInvalid();
}
UsingDecl *UD = BuildValid();
// Some additional rules apply to inheriting constructors.
if (UsingName.getName().getNameKind() ==
DeclarationName::CXXConstructorName) {
// Suppress access diagnostics; the access check is instead performed at the
// point of use for an inheriting constructor.
R.suppressDiagnostics();
if (CheckInheritingConstructorUsingDecl(UD))
return UD;
}
for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
UsingShadowDecl *PrevDecl = nullptr;
if (!CheckUsingShadowDecl(UD, *I, Previous, PrevDecl))
BuildUsingShadowDecl(S, UD, *I, PrevDecl);
}
return UD;
}
NamedDecl *Sema::BuildUsingEnumDeclaration(Scope *S, AccessSpecifier AS,
SourceLocation UsingLoc,
SourceLocation EnumLoc,
SourceLocation NameLoc,
EnumDecl *ED) {
bool Invalid = false;
if (CurContext->getRedeclContext()->isRecord()) {
/// In class scope, check if this is a duplicate, for better a diagnostic.
DeclarationNameInfo UsingEnumName(ED->getDeclName(), NameLoc);
LookupResult Previous(*this, UsingEnumName, LookupUsingDeclName,
ForVisibleRedeclaration);
LookupName(Previous, S);
for (NamedDecl *D : Previous)
if (UsingEnumDecl *UED = dyn_cast<UsingEnumDecl>(D))
if (UED->getEnumDecl() == ED) {
Diag(UsingLoc, diag::err_using_enum_decl_redeclaration)
<< SourceRange(EnumLoc, NameLoc);
Diag(D->getLocation(), diag::note_using_enum_decl) << 1;
Invalid = true;
break;
}
}
if (RequireCompleteEnumDecl(ED, NameLoc))
Invalid = true;
UsingEnumDecl *UD = UsingEnumDecl::Create(Context, CurContext, UsingLoc,
EnumLoc, NameLoc, ED);
UD->setAccess(AS);
CurContext->addDecl(UD);
if (Invalid) {
UD->setInvalidDecl();
return UD;
}
// Create the shadow decls for each enumerator
for (EnumConstantDecl *EC : ED->enumerators()) {
UsingShadowDecl *PrevDecl = nullptr;
DeclarationNameInfo DNI(EC->getDeclName(), EC->getLocation());
LookupResult Previous(*this, DNI, LookupOrdinaryName,
ForVisibleRedeclaration);
LookupName(Previous, S);
FilterUsingLookup(S, Previous);
if (!CheckUsingShadowDecl(UD, EC, Previous, PrevDecl))
BuildUsingShadowDecl(S, UD, EC, PrevDecl);
}
return UD;
}
NamedDecl *Sema::BuildUsingPackDecl(NamedDecl *InstantiatedFrom,
ArrayRef<NamedDecl *> Expansions) {
assert(isa<UnresolvedUsingValueDecl>(InstantiatedFrom) ||
isa<UnresolvedUsingTypenameDecl>(InstantiatedFrom) ||
isa<UsingPackDecl>(InstantiatedFrom));
auto *UPD =
UsingPackDecl::Create(Context, CurContext, InstantiatedFrom, Expansions);
UPD->setAccess(InstantiatedFrom->getAccess());
CurContext->addDecl(UPD);
return UPD;
}
/// Additional checks for a using declaration referring to a constructor name.
bool Sema::CheckInheritingConstructorUsingDecl(UsingDecl *UD) {
assert(!UD->hasTypename() && "expecting a constructor name");
const Type *SourceType = UD->getQualifier()->getAsType();
assert(SourceType &&
"Using decl naming constructor doesn't have type in scope spec.");
CXXRecordDecl *TargetClass = cast<CXXRecordDecl>(CurContext);
// Check whether the named type is a direct base class.
bool AnyDependentBases = false;
auto *Base = findDirectBaseWithType(TargetClass, QualType(SourceType, 0),
AnyDependentBases);
if (!Base && !AnyDependentBases) {
Diag(UD->getUsingLoc(),
diag::err_using_decl_constructor_not_in_direct_base)
<< UD->getNameInfo().getSourceRange()
<< QualType(SourceType, 0) << TargetClass;
UD->setInvalidDecl();
return true;
}
if (Base)
Base->setInheritConstructors();
return false;
}
/// Checks that the given using declaration is not an invalid
/// redeclaration. Note that this is checking only for the using decl
/// itself, not for any ill-formedness among the UsingShadowDecls.
bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
bool HasTypenameKeyword,
const CXXScopeSpec &SS,
SourceLocation NameLoc,
const LookupResult &Prev) {
NestedNameSpecifier *Qual = SS.getScopeRep();
// C++03 [namespace.udecl]p8:
// C++0x [namespace.udecl]p10:
// A using-declaration is a declaration and can therefore be used
// repeatedly where (and only where) multiple declarations are
// allowed.
//
// That's in non-member contexts.
if (!CurContext->getRedeclContext()->isRecord()) {
// A dependent qualifier outside a class can only ever resolve to an
// enumeration type. Therefore it conflicts with any other non-type
// declaration in the same scope.
// FIXME: How should we check for dependent type-type conflicts at block
// scope?
if (Qual->isDependent() && !HasTypenameKeyword) {
for (auto *D : Prev) {
if (!isa<TypeDecl>(D) && !isa<UsingDecl>(D) && !isa<UsingPackDecl>(D)) {
bool OldCouldBeEnumerator =
isa<UnresolvedUsingValueDecl>(D) || isa<EnumConstantDecl>(D);
Diag(NameLoc,
OldCouldBeEnumerator ? diag::err_redefinition
: diag::err_redefinition_different_kind)
<< Prev.getLookupName();
Diag(D->getLocation(), diag::note_previous_definition);
return true;
}
}
}
return false;
}
const NestedNameSpecifier *CNNS =
Context.getCanonicalNestedNameSpecifier(Qual);
for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) {
NamedDecl *D = *I;
bool DTypename;
NestedNameSpecifier *DQual;
if (UsingDecl *UD = dyn_cast<UsingDecl>(D)) {
DTypename = UD->hasTypename();
DQual = UD->getQualifier();
} else if (UnresolvedUsingValueDecl *UD
= dyn_cast<UnresolvedUsingValueDecl>(D)) {
DTypename = false;
DQual = UD->getQualifier();
} else if (UnresolvedUsingTypenameDecl *UD
= dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
DTypename = true;
DQual = UD->getQualifier();
} else continue;
// using decls differ if one says 'typename' and the other doesn't.
// FIXME: non-dependent using decls?
if (HasTypenameKeyword != DTypename) continue;
// using decls differ if they name different scopes (but note that
// template instantiation can cause this check to trigger when it
// didn't before instantiation).
if (CNNS != Context.getCanonicalNestedNameSpecifier(DQual))
continue;
Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange();
Diag(D->getLocation(), diag::note_using_decl) << 1;
return true;
}
return false;
}
/// Checks that the given nested-name qualifier used in a using decl
/// in the current context is appropriately related to the current
/// scope. If an error is found, diagnoses it and returns true.
/// R is nullptr, if the caller has not (yet) done a lookup, otherwise it's the
/// result of that lookup. UD is likewise nullptr, except when we have an
/// already-populated UsingDecl whose shadow decls contain the same information
/// (i.e. we're instantiating a UsingDecl with non-dependent scope).
bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc, bool HasTypename,
const CXXScopeSpec &SS,
const DeclarationNameInfo &NameInfo,
SourceLocation NameLoc,
const LookupResult *R, const UsingDecl *UD) {
DeclContext *NamedContext = computeDeclContext(SS);
assert(bool(NamedContext) == (R || UD) && !(R && UD) &&
"resolvable context must have exactly one set of decls");
// C++ 20 permits using an enumerator that does not have a class-hierarchy
// relationship.
bool Cxx20Enumerator = false;
if (NamedContext) {
EnumConstantDecl *EC = nullptr;
if (R)
EC = R->getAsSingle<EnumConstantDecl>();
else if (UD && UD->shadow_size() == 1)
EC = dyn_cast<EnumConstantDecl>(UD->shadow_begin()->getTargetDecl());
if (EC)
Cxx20Enumerator = getLangOpts().CPlusPlus20;
if (auto *ED = dyn_cast<EnumDecl>(NamedContext)) {
// C++14 [namespace.udecl]p7:
// A using-declaration shall not name a scoped enumerator.
// C++20 p1099 permits enumerators.
if (EC && R && ED->isScoped())
Diag(SS.getBeginLoc(),
getLangOpts().CPlusPlus20
? diag::warn_cxx17_compat_using_decl_scoped_enumerator
: diag::ext_using_decl_scoped_enumerator)
<< SS.getRange();
// We want to consider the scope of the enumerator
NamedContext = ED->getDeclContext();
}
}
if (!CurContext->isRecord()) {
// C++03 [namespace.udecl]p3:
// C++0x [namespace.udecl]p8:
// A using-declaration for a class member shall be a member-declaration.
// C++20 [namespace.udecl]p7
// ... other than an enumerator ...
// If we weren't able to compute a valid scope, it might validly be a
// dependent class or enumeration scope. If we have a 'typename' keyword,
// the scope must resolve to a class type.
if (NamedContext ? !NamedContext->getRedeclContext()->isRecord()
: !HasTypename)
return false; // OK
Diag(NameLoc,
Cxx20Enumerator
? diag::warn_cxx17_compat_using_decl_class_member_enumerator
: diag::err_using_decl_can_not_refer_to_class_member)
<< SS.getRange();
if (Cxx20Enumerator)
return false; // OK
auto *RD = NamedContext
? cast<CXXRecordDecl>(NamedContext->getRedeclContext())
: nullptr;
if (RD && !RequireCompleteDeclContext(const_cast<CXXScopeSpec &>(SS), RD)) {
// See if there's a helpful fixit
if (!R) {
// We will have already diagnosed the problem on the template
// definition, Maybe we should do so again?
} else if (R->getAsSingle<TypeDecl>()) {
if (getLangOpts().CPlusPlus11) {
// Convert 'using X::Y;' to 'using Y = X::Y;'.
Diag(SS.getBeginLoc(), diag::note_using_decl_class_member_workaround)
<< 0 // alias declaration
<< FixItHint::CreateInsertion(SS.getBeginLoc(),
NameInfo.getName().getAsString() +
" = ");
} else {
// Convert 'using X::Y;' to 'typedef X::Y Y;'.
SourceLocation InsertLoc = getLocForEndOfToken(NameInfo.getEndLoc());
Diag(InsertLoc, diag::note_using_decl_class_member_workaround)
<< 1 // typedef declaration
<< FixItHint::CreateReplacement(UsingLoc, "typedef")
<< FixItHint::CreateInsertion(
InsertLoc, " " + NameInfo.getName().getAsString());
}
} else if (R->getAsSingle<VarDecl>()) {
// Don't provide a fixit outside C++11 mode; we don't want to suggest
// repeating the type of the static data member here.
FixItHint FixIt;
if (getLangOpts().CPlusPlus11) {
// Convert 'using X::Y;' to 'auto &Y = X::Y;'.
FixIt = FixItHint::CreateReplacement(
UsingLoc, "auto &" + NameInfo.getName().getAsString() + " = ");
}
Diag(UsingLoc, diag::note_using_decl_class_member_workaround)
<< 2 // reference declaration
<< FixIt;
} else if (R->getAsSingle<EnumConstantDecl>()) {
// Don't provide a fixit outside C++11 mode; we don't want to suggest
// repeating the type of the enumeration here, and we can't do so if
// the type is anonymous.
FixItHint FixIt;
if (getLangOpts().CPlusPlus11) {
// Convert 'using X::Y;' to 'auto &Y = X::Y;'.
FixIt = FixItHint::CreateReplacement(
UsingLoc,
"constexpr auto " + NameInfo.getName().getAsString() + " = ");
}
Diag(UsingLoc, diag::note_using_decl_class_member_workaround)
<< (getLangOpts().CPlusPlus11 ? 4 : 3) // const[expr] variable
<< FixIt;
}
}
return true; // Fail
}
// If the named context is dependent, we can't decide much.
if (!NamedContext) {
// FIXME: in C++0x, we can diagnose if we can prove that the
// nested-name-specifier does not refer to a base class, which is
// still possible in some cases.
// Otherwise we have to conservatively report that things might be
// okay.
return false;
}
// The current scope is a record.
if (!NamedContext->isRecord()) {
// Ideally this would point at the last name in the specifier,
// but we don't have that level of source info.
Diag(SS.getBeginLoc(),
Cxx20Enumerator
? diag::warn_cxx17_compat_using_decl_non_member_enumerator
: diag::err_using_decl_nested_name_specifier_is_not_class)
<< SS.getScopeRep() << SS.getRange();
if (Cxx20Enumerator)
return false; // OK
return true;
}
if (!NamedContext->isDependentContext() &&
RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), NamedContext))
return true;
if (getLangOpts().CPlusPlus11) {
// C++11 [namespace.udecl]p3:
// In a using-declaration used as a member-declaration, the
// nested-name-specifier shall name a base class of the class
// being defined.
if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(
cast<CXXRecordDecl>(NamedContext))) {
if (Cxx20Enumerator) {
Diag(NameLoc, diag::warn_cxx17_compat_using_decl_non_member_enumerator)
<< SS.getRange();
return false;
}
if (CurContext == NamedContext) {
Diag(SS.getBeginLoc(),
diag::err_using_decl_nested_name_specifier_is_current_class)
<< SS.getRange();
return !getLangOpts().CPlusPlus20;
}
if (!cast<CXXRecordDecl>(NamedContext)->isInvalidDecl()) {
Diag(SS.getBeginLoc(),
diag::err_using_decl_nested_name_specifier_is_not_base_class)
<< SS.getScopeRep() << cast<CXXRecordDecl>(CurContext)
<< SS.getRange();
}
return true;
}
return false;
}
// C++03 [namespace.udecl]p4:
// A using-declaration used as a member-declaration shall refer
// to a member of a base class of the class being defined [etc.].
// Salient point: SS doesn't have to name a base class as long as
// lookup only finds members from base classes. Therefore we can
// diagnose here only if we can prove that that can't happen,
// i.e. if the class hierarchies provably don't intersect.
// TODO: it would be nice if "definitely valid" results were cached
// in the UsingDecl and UsingShadowDecl so that these checks didn't
// need to be repeated.
llvm::SmallPtrSet<const CXXRecordDecl *, 4> Bases;
auto Collect = [&Bases](const CXXRecordDecl *Base) {
Bases.insert(Base);
return true;
};
// Collect all bases. Return false if we find a dependent base.
if (!cast<CXXRecordDecl>(CurContext)->forallBases(Collect))
return false;
// Returns true if the base is dependent or is one of the accumulated base
// classes.
auto IsNotBase = [&Bases](const CXXRecordDecl *Base) {
return !Bases.count(Base);
};
// Return false if the class has a dependent base or if it or one
// of its bases is present in the base set of the current context.
if (Bases.count(cast<CXXRecordDecl>(NamedContext)) ||
!cast<CXXRecordDecl>(NamedContext)->forallBases(IsNotBase))
return false;
Diag(SS.getRange().getBegin(),
diag::err_using_decl_nested_name_specifier_is_not_base_class)
<< SS.getScopeRep()
<< cast<CXXRecordDecl>(CurContext)
<< SS.getRange();
return true;
}
Decl *Sema::ActOnAliasDeclaration(Scope *S, AccessSpecifier AS,
MultiTemplateParamsArg TemplateParamLists,
SourceLocation UsingLoc, UnqualifiedId &Name,
const ParsedAttributesView &AttrList,
TypeResult Type, Decl *DeclFromDeclSpec) {
// Skip up to the relevant declaration scope.
while (S->isTemplateParamScope())
S = S->getParent();
assert((S->getFlags() & Scope::DeclScope) &&
"got alias-declaration outside of declaration scope");
if (Type.isInvalid())
return nullptr;
bool Invalid = false;
DeclarationNameInfo NameInfo = GetNameFromUnqualifiedId(Name);
TypeSourceInfo *TInfo = nullptr;
GetTypeFromParser(Type.get(), &TInfo);
if (DiagnoseClassNameShadow(CurContext, NameInfo))
return nullptr;
if (DiagnoseUnexpandedParameterPack(Name.StartLocation, TInfo,
UPPC_DeclarationType)) {
Invalid = true;
TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
TInfo->getTypeLoc().getBeginLoc());
}
LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
TemplateParamLists.size()
? forRedeclarationInCurContext()
: ForVisibleRedeclaration);
LookupName(Previous, S);
// Warn about shadowing the name of a template parameter.
if (Previous.isSingleResult() &&
Previous.getFoundDecl()->isTemplateParameter()) {
DiagnoseTemplateParameterShadow(Name.StartLocation,Previous.getFoundDecl());
Previous.clear();
}
assert(Name.Kind == UnqualifiedIdKind::IK_Identifier &&
"name in alias declaration must be an identifier");
TypeAliasDecl *NewTD = TypeAliasDecl::Create(Context, CurContext, UsingLoc,
Name.StartLocation,
Name.Identifier, TInfo);
NewTD->setAccess(AS);
if (Invalid)
NewTD->setInvalidDecl();
ProcessDeclAttributeList(S, NewTD, AttrList);
AddPragmaAttributes(S, NewTD);
CheckTypedefForVariablyModifiedType(S, NewTD);
Invalid |= NewTD->isInvalidDecl();
bool Redeclaration = false;
NamedDecl *NewND;
if (TemplateParamLists.size()) {
TypeAliasTemplateDecl *OldDecl = nullptr;
TemplateParameterList *OldTemplateParams = nullptr;
if (TemplateParamLists.size() != 1) {
Diag(UsingLoc, diag::err_alias_template_extra_headers)
<< SourceRange(TemplateParamLists[1]->getTemplateLoc(),
TemplateParamLists[TemplateParamLists.size()-1]->getRAngleLoc());
}
TemplateParameterList *TemplateParams = TemplateParamLists[0];
// Check that we can declare a template here.
if (CheckTemplateDeclScope(S, TemplateParams))
return nullptr;
// Only consider previous declarations in the same scope.
FilterLookupForScope(Previous, CurContext, S, /*ConsiderLinkage*/false,
/*ExplicitInstantiationOrSpecialization*/false);
if (!Previous.empty()) {
Redeclaration = true;
OldDecl = Previous.getAsSingle<TypeAliasTemplateDecl>();
if (!OldDecl && !Invalid) {
Diag(UsingLoc, diag::err_redefinition_different_kind)
<< Name.Identifier;
NamedDecl *OldD = Previous.getRepresentativeDecl();
if (OldD->getLocation().isValid())
Diag(OldD->getLocation(), diag::note_previous_definition);
Invalid = true;
}
if (!Invalid && OldDecl && !OldDecl->isInvalidDecl()) {
if (TemplateParameterListsAreEqual(TemplateParams,
OldDecl->getTemplateParameters(),
/*Complain=*/true,
TPL_TemplateMatch))
OldTemplateParams =
OldDecl->getMostRecentDecl()->getTemplateParameters();
else
Invalid = true;
TypeAliasDecl *OldTD = OldDecl->getTemplatedDecl();
if (!Invalid &&
!Context.hasSameType(OldTD->getUnderlyingType(),
NewTD->getUnderlyingType())) {
// FIXME: The C++0x standard does not clearly say this is ill-formed,
// but we can't reasonably accept it.
Diag(NewTD->getLocation(), diag::err_redefinition_different_typedef)
<< 2 << NewTD->getUnderlyingType() << OldTD->getUnderlyingType();
if (OldTD->getLocation().isValid())
Diag(OldTD->getLocation(), diag::note_previous_definition);
Invalid = true;
}
}
}
// Merge any previous default template arguments into our parameters,
// and check the parameter list.
if (CheckTemplateParameterList(TemplateParams, OldTemplateParams,
TPC_TypeAliasTemplate))
return nullptr;
TypeAliasTemplateDecl *NewDecl =
TypeAliasTemplateDecl::Create(Context, CurContext, UsingLoc,
Name.Identifier, TemplateParams,
NewTD);
NewTD->setDescribedAliasTemplate(NewDecl);
NewDecl->setAccess(AS);
if (Invalid)
NewDecl->setInvalidDecl();
else if (OldDecl) {
NewDecl->setPreviousDecl(OldDecl);
CheckRedeclarationModuleOwnership(NewDecl, OldDecl);
}
NewND = NewDecl;
} else {
if (auto *TD = dyn_cast_or_null<TagDecl>(DeclFromDeclSpec)) {
setTagNameForLinkagePurposes(TD, NewTD);
handleTagNumbering(TD, S);
}
ActOnTypedefNameDecl(S, CurContext, NewTD, Previous, Redeclaration);
NewND = NewTD;
}
PushOnScopeChains(NewND, S);
ActOnDocumentableDecl(NewND);
return NewND;
}
Decl *Sema::ActOnNamespaceAliasDef(Scope *S, SourceLocation NamespaceLoc,
SourceLocation AliasLoc,
IdentifierInfo *Alias, CXXScopeSpec &SS,
SourceLocation IdentLoc,
IdentifierInfo *Ident) {
// Lookup the namespace name.
LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName);
LookupParsedName(R, S, &SS);
if (R.isAmbiguous())
return nullptr;
if (R.empty()) {
if (!TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, Ident)) {
Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
return nullptr;
}
}
assert(!R.isAmbiguous() && !R.empty());
NamedDecl *ND = R.getRepresentativeDecl();
// Check if we have a previous declaration with the same name.
LookupResult PrevR(*this, Alias, AliasLoc, LookupOrdinaryName,
ForVisibleRedeclaration);
LookupName(PrevR, S);
// Check we're not shadowing a template parameter.
if (PrevR.isSingleResult() && PrevR.getFoundDecl()->isTemplateParameter()) {
DiagnoseTemplateParameterShadow(AliasLoc, PrevR.getFoundDecl());
PrevR.clear();
}
// Filter out any other lookup result from an enclosing scope.
FilterLookupForScope(PrevR, CurContext, S, /*ConsiderLinkage*/false,
/*AllowInlineNamespace*/false);
// Find the previous declaration and check that we can redeclare it.
NamespaceAliasDecl *Prev = nullptr;
if (PrevR.isSingleResult()) {
NamedDecl *PrevDecl = PrevR.getRepresentativeDecl();
if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
// We already have an alias with the same name that points to the same
// namespace; check that it matches.
if (AD->getNamespace()->Equals(getNamespaceDecl(ND))) {
Prev = AD;
} else if (isVisible(PrevDecl)) {
Diag(AliasLoc, diag::err_redefinition_different_namespace_alias)
<< Alias;
Diag(AD->getLocation(), diag::note_previous_namespace_alias)
<< AD->getNamespace();
return nullptr;
}
} else if (isVisible(PrevDecl)) {
unsigned DiagID = isa<NamespaceDecl>(PrevDecl->getUnderlyingDecl())
? diag::err_redefinition
: diag::err_redefinition_different_kind;
Diag(AliasLoc, DiagID) << Alias;
Diag(PrevDecl->getLocation(), diag::note_previous_definition);
return nullptr;
}
}
// The use of a nested name specifier may trigger deprecation warnings.
DiagnoseUseOfDecl(ND, IdentLoc);
NamespaceAliasDecl *AliasDecl =
NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc,
Alias, SS.getWithLocInContext(Context),
IdentLoc, ND);
if (Prev)
AliasDecl->setPreviousDecl(Prev);
PushOnScopeChains(AliasDecl, S);
return AliasDecl;
}
namespace {
struct SpecialMemberExceptionSpecInfo
: SpecialMemberVisitor<SpecialMemberExceptionSpecInfo> {
SourceLocation Loc;
Sema::ImplicitExceptionSpecification ExceptSpec;
SpecialMemberExceptionSpecInfo(Sema &S, CXXMethodDecl *MD,
Sema::CXXSpecialMember CSM,
Sema::InheritedConstructorInfo *ICI,
SourceLocation Loc)
: SpecialMemberVisitor(S, MD, CSM, ICI), Loc(Loc), ExceptSpec(S) {}
bool visitBase(CXXBaseSpecifier *Base);
bool visitField(FieldDecl *FD);
void visitClassSubobject(CXXRecordDecl *Class, Subobject Subobj,
unsigned Quals);
void visitSubobjectCall(Subobject Subobj,
Sema::SpecialMemberOverloadResult SMOR);
};
}
bool SpecialMemberExceptionSpecInfo::visitBase(CXXBaseSpecifier *Base) {
auto *RT = Base->getType()->getAs<RecordType>();
if (!RT)
return false;
auto *BaseClass = cast<CXXRecordDecl>(RT->getDecl());
Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass);
if (auto *BaseCtor = SMOR.getMethod()) {
visitSubobjectCall(Base, BaseCtor);
return false;
}
visitClassSubobject(BaseClass, Base, 0);
return false;
}
bool SpecialMemberExceptionSpecInfo::visitField(FieldDecl *FD) {
if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer()) {
Expr *E = FD->getInClassInitializer();
if (!E)
// FIXME: It's a little wasteful to build and throw away a
// CXXDefaultInitExpr here.
// FIXME: We should have a single context note pointing at Loc, and
// this location should be MD->getLocation() instead, since that's
// the location where we actually use the default init expression.
E = S.BuildCXXDefaultInitExpr(Loc, FD).get();
if (E)
ExceptSpec.CalledExpr(E);
} else if (auto *RT = S.Context.getBaseElementType(FD->getType())
->getAs<RecordType>()) {
visitClassSubobject(cast<CXXRecordDecl>(RT->getDecl()), FD,
FD->getType().getCVRQualifiers());
}
return false;
}
void SpecialMemberExceptionSpecInfo::visitClassSubobject(CXXRecordDecl *Class,
Subobject Subobj,
unsigned Quals) {
FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
bool IsMutable = Field && Field->isMutable();
visitSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable));
}
void SpecialMemberExceptionSpecInfo::visitSubobjectCall(
Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR) {
// Note, if lookup fails, it doesn't matter what exception specification we
// choose because the special member will be deleted.
if (CXXMethodDecl *MD = SMOR.getMethod())
ExceptSpec.CalledDecl(getSubobjectLoc(Subobj), MD);
}
bool Sema::tryResolveExplicitSpecifier(ExplicitSpecifier &ExplicitSpec) {
llvm::APSInt Result;
ExprResult Converted = CheckConvertedConstantExpression(
ExplicitSpec.getExpr(), Context.BoolTy, Result, CCEK_ExplicitBool);
ExplicitSpec.setExpr(Converted.get());
if (Converted.isUsable() && !Converted.get()->isValueDependent()) {
ExplicitSpec.setKind(Result.getBoolValue()
? ExplicitSpecKind::ResolvedTrue
: ExplicitSpecKind::ResolvedFalse);
return true;
}
ExplicitSpec.setKind(ExplicitSpecKind::Unresolved);
return false;
}
ExplicitSpecifier Sema::ActOnExplicitBoolSpecifier(Expr *ExplicitExpr) {
ExplicitSpecifier ES(ExplicitExpr, ExplicitSpecKind::Unresolved);
if (!ExplicitExpr->isTypeDependent())
tryResolveExplicitSpecifier(ES);
return ES;
}
static Sema::ImplicitExceptionSpecification
ComputeDefaultedSpecialMemberExceptionSpec(
Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
Sema::InheritedConstructorInfo *ICI) {
ComputingExceptionSpec CES(S, MD, Loc);
CXXRecordDecl *ClassDecl = MD->getParent();
// C++ [except.spec]p14:
// An implicitly declared special member function (Clause 12) shall have an
// exception-specification. [...]
SpecialMemberExceptionSpecInfo Info(S, MD, CSM, ICI, MD->getLocation());
if (ClassDecl->isInvalidDecl())
return Info.ExceptSpec;
// FIXME: If this diagnostic fires, we're probably missing a check for
// attempting to resolve an exception specification before it's known
// at a higher level.
if (S.RequireCompleteType(MD->getLocation(),
S.Context.getRecordType(ClassDecl),
diag::err_exception_spec_incomplete_type))
return Info.ExceptSpec;
// C++1z [except.spec]p7:
// [Look for exceptions thrown by] a constructor selected [...] to
// initialize a potentially constructed subobject,
// C++1z [except.spec]p8:
// The exception specification for an implicitly-declared destructor, or a
// destructor without a noexcept-specifier, is potentially-throwing if and
// only if any of the destructors for any of its potentially constructed
// subojects is potentially throwing.
// FIXME: We respect the first rule but ignore the "potentially constructed"
// in the second rule to resolve a core issue (no number yet) that would have
// us reject:
// struct A { virtual void f() = 0; virtual ~A() noexcept(false) = 0; };
// struct B : A {};
// struct C : B { void f(); };
// ... due to giving B::~B() a non-throwing exception specification.
Info.visit(Info.IsConstructor ? Info.VisitPotentiallyConstructedBases
: Info.VisitAllBases);
return Info.ExceptSpec;
}
namespace {
/// RAII object to register a special member as being currently declared.
struct DeclaringSpecialMember {
Sema &S;
Sema::SpecialMemberDecl D;
Sema::ContextRAII SavedContext;
bool WasAlreadyBeingDeclared;
DeclaringSpecialMember(Sema &S, CXXRecordDecl *RD, Sema::CXXSpecialMember CSM)
: S(S), D(RD, CSM), SavedContext(S, RD) {
WasAlreadyBeingDeclared = !S.SpecialMembersBeingDeclared.insert(D).second;
if (WasAlreadyBeingDeclared)
// This almost never happens, but if it does, ensure that our cache
// doesn't contain a stale result.
S.SpecialMemberCache.clear();
else {
// Register a note to be produced if we encounter an error while
// declaring the special member.
Sema::CodeSynthesisContext Ctx;
Ctx.Kind = Sema::CodeSynthesisContext::DeclaringSpecialMember;
// FIXME: We don't have a location to use here. Using the class's
// location maintains the fiction that we declare all special members
// with the class, but (1) it's not clear that lying about that helps our
// users understand what's going on, and (2) there may be outer contexts
// on the stack (some of which are relevant) and printing them exposes
// our lies.
Ctx.PointOfInstantiation = RD->getLocation();
Ctx.Entity = RD;
Ctx.SpecialMember = CSM;
S.pushCodeSynthesisContext(Ctx);
}
}
~DeclaringSpecialMember() {
if (!WasAlreadyBeingDeclared) {
S.SpecialMembersBeingDeclared.erase(D);
S.popCodeSynthesisContext();
}
}
/// Are we already trying to declare this special member?
bool isAlreadyBeingDeclared() const {
return WasAlreadyBeingDeclared;
}
};
}
void Sema::CheckImplicitSpecialMemberDeclaration(Scope *S, FunctionDecl *FD) {
// Look up any existing declarations, but don't trigger declaration of all
// implicit special members with this name.
DeclarationName Name = FD->getDeclName();
LookupResult R(*this, Name, SourceLocation(), LookupOrdinaryName,
ForExternalRedeclaration);
for (auto *D : FD->getParent()->lookup(Name))
if (auto *Acceptable = R.getAcceptableDecl(D))
R.addDecl(Acceptable);
R.resolveKind();
R.suppressDiagnostics();
CheckFunctionDeclaration(S, FD, R, /*IsMemberSpecialization*/false);
}
void Sema::setupImplicitSpecialMemberType(CXXMethodDecl *SpecialMem,
QualType ResultTy,
ArrayRef<QualType> Args) {
// Build an exception specification pointing back at this constructor.
FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, SpecialMem);
LangAS AS = getDefaultCXXMethodAddrSpace();
if (AS != LangAS::Default) {
EPI.TypeQuals.addAddressSpace(AS);
}
auto QT = Context.getFunctionType(ResultTy, Args, EPI);
SpecialMem->setType(QT);
// During template instantiation of implicit special member functions we need
// a reliable TypeSourceInfo for the function prototype in order to allow
// functions to be substituted.
if (inTemplateInstantiation() &&
cast<CXXRecordDecl>(SpecialMem->getParent())->isLambda()) {
TypeSourceInfo *TSI =
Context.getTrivialTypeSourceInfo(SpecialMem->getType());
SpecialMem->setTypeSourceInfo(TSI);
}
}
CXXConstructorDecl *Sema::DeclareImplicitDefaultConstructor(
CXXRecordDecl *ClassDecl) {
// C++ [class.ctor]p5:
// A default constructor for a class X is a constructor of class X
// that can be called without an argument. If there is no
// user-declared constructor for class X, a default constructor is
// implicitly declared. An implicitly-declared default constructor
// is an inline public member of its class.
assert(ClassDecl->needsImplicitDefaultConstructor() &&
"Should not build implicit default constructor!");
DeclaringSpecialMember DSM(*this, ClassDecl, CXXDefaultConstructor);
if (DSM.isAlreadyBeingDeclared())
return nullptr;
bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
CXXDefaultConstructor,
false);
// Create the actual constructor declaration.
CanQualType ClassType
= Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
SourceLocation ClassLoc = ClassDecl->getLocation();
DeclarationName Name
= Context.DeclarationNames.getCXXConstructorName(ClassType);
DeclarationNameInfo NameInfo(Name, ClassLoc);
CXXConstructorDecl *DefaultCon = CXXConstructorDecl::Create(
Context, ClassDecl, ClassLoc, NameInfo, /*Type*/ QualType(),
/*TInfo=*/nullptr, ExplicitSpecifier(),
getCurFPFeatures().isFPConstrained(),
/*isInline=*/true, /*isImplicitlyDeclared=*/true,
Constexpr ? ConstexprSpecKind::Constexpr
: ConstexprSpecKind::Unspecified);
DefaultCon->setAccess(AS_public);
DefaultCon->setDefaulted();
if (getLangOpts().CUDA) {
inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDefaultConstructor,
DefaultCon,
/* ConstRHS */ false,
/* Diagnose */ false);
}
setupImplicitSpecialMemberType(DefaultCon, Context.VoidTy, None);
// We don't need to use SpecialMemberIsTrivial here; triviality for default
// constructors is easy to compute.
DefaultCon->setTrivial(ClassDecl->hasTrivialDefaultConstructor());
// Note that we have declared this constructor.
++getASTContext().NumImplicitDefaultConstructorsDeclared;
Scope *S = getScopeForContext(ClassDecl);
CheckImplicitSpecialMemberDeclaration(S, DefaultCon);
if (ShouldDeleteSpecialMember(DefaultCon, CXXDefaultConstructor))
SetDeclDeleted(DefaultCon, ClassLoc);
if (S)
PushOnScopeChains(DefaultCon, S, false);
ClassDecl->addDecl(DefaultCon);
return DefaultCon;
}
void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
CXXConstructorDecl *Constructor) {
assert((Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&
!Constructor->doesThisDeclarationHaveABody() &&
!Constructor->isDeleted()) &&
"DefineImplicitDefaultConstructor - call it for implicit default ctor");
if (Constructor->willHaveBody() || Constructor->isInvalidDecl())
return;
CXXRecordDecl *ClassDecl = Constructor->getParent();
assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor");
SynthesizedFunctionScope Scope(*this, Constructor);
// The exception specification is needed because we are defining the
// function.
ResolveExceptionSpec(CurrentLocation,
Constructor->getType()->castAs<FunctionProtoType>());
MarkVTableUsed(CurrentLocation, ClassDecl);
// Add a context note for diagnostics produced after this point.
Scope.addContextNote(CurrentLocation);
if (SetCtorInitializers(Constructor, /*AnyErrors=*/false)) {
Constructor->setInvalidDecl();
return;
}
SourceLocation Loc = Constructor->getEndLoc().isValid()
? Constructor->getEndLoc()
: Constructor->getLocation();
Constructor->setBody(new (Context) CompoundStmt(Loc));
Constructor->markUsed(Context);
if (ASTMutationListener *L = getASTMutationListener()) {
L->CompletedImplicitDefinition(Constructor);
}
DiagnoseUninitializedFields(*this, Constructor);
}
void Sema::ActOnFinishDelayedMemberInitializers(Decl *D) {
// Perform any delayed checks on exception specifications.
CheckDelayedMemberExceptionSpecs();
}
/// Find or create the fake constructor we synthesize to model constructing an
/// object of a derived class via a constructor of a base class.
CXXConstructorDecl *
Sema::findInheritingConstructor(SourceLocation Loc,
CXXConstructorDecl *BaseCtor,
ConstructorUsingShadowDecl *Shadow) {
CXXRecordDecl *Derived = Shadow->getParent();
SourceLocation UsingLoc = Shadow->getLocation();
// FIXME: Add a new kind of DeclarationName for an inherited constructor.
// For now we use the name of the base class constructor as a member of the
// derived class to indicate a (fake) inherited constructor name.
DeclarationName Name = BaseCtor->getDeclName();
// Check to see if we already have a fake constructor for this inherited
// constructor call.
for (NamedDecl *Ctor : Derived->lookup(Name))
if (declaresSameEntity(cast<CXXConstructorDecl>(Ctor)
->getInheritedConstructor()
.getConstructor(),
BaseCtor))
return cast<CXXConstructorDecl>(Ctor);
DeclarationNameInfo NameInfo(Name, UsingLoc);
TypeSourceInfo *TInfo =
Context.getTrivialTypeSourceInfo(BaseCtor->getType(), UsingLoc);
FunctionProtoTypeLoc ProtoLoc =
TInfo->getTypeLoc().IgnoreParens().castAs<FunctionProtoTypeLoc>();
// Check the inherited constructor is valid and find the list of base classes
// from which it was inherited.
InheritedConstructorInfo ICI(*this, Loc, Shadow);
bool Constexpr =
BaseCtor->isConstexpr() &&
defaultedSpecialMemberIsConstexpr(*this, Derived, CXXDefaultConstructor,
false, BaseCtor, &ICI);
CXXConstructorDecl *DerivedCtor = CXXConstructorDecl::Create(
Context, Derived, UsingLoc, NameInfo, TInfo->getType(), TInfo,
BaseCtor->getExplicitSpecifier(), getCurFPFeatures().isFPConstrained(),
/*isInline=*/true,
/*isImplicitlyDeclared=*/true,
Constexpr ? BaseCtor->getConstexprKind() : ConstexprSpecKind::Unspecified,
InheritedConstructor(Shadow, BaseCtor),
BaseCtor->getTrailingRequiresClause());
if (Shadow->isInvalidDecl())
DerivedCtor->setInvalidDecl();
// Build an unevaluated exception specification for this fake constructor.
const FunctionProtoType *FPT = TInfo->getType()->castAs<FunctionProtoType>();
FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
EPI.ExceptionSpec.Type = EST_Unevaluated;
EPI.ExceptionSpec.SourceDecl = DerivedCtor;
DerivedCtor->setType(Context.getFunctionType(FPT->getReturnType(),
FPT->getParamTypes(), EPI));
// Build the parameter declarations.
SmallVector<ParmVarDecl *, 16> ParamDecls;
for (unsigned I = 0, N = FPT->getNumParams(); I != N; ++I) {
TypeSourceInfo *TInfo =
Context.getTrivialTypeSourceInfo(FPT->getParamType(I), UsingLoc);
ParmVarDecl *PD = ParmVarDecl::Create(
Context, DerivedCtor, UsingLoc, UsingLoc, /*IdentifierInfo=*/nullptr,
FPT->getParamType(I), TInfo, SC_None, /*DefArg=*/nullptr);
PD->setScopeInfo(0, I);
PD->setImplicit();
// Ensure attributes are propagated onto parameters (this matters for
// format, pass_object_size, ...).
mergeDeclAttributes(PD, BaseCtor->getParamDecl(I));
ParamDecls.push_back(PD);
ProtoLoc.setParam(I, PD);
}
// Set up the new constructor.
assert(!BaseCtor->isDeleted() && "should not use deleted constructor");
DerivedCtor->setAccess(BaseCtor->getAccess());
DerivedCtor->setParams(ParamDecls);
Derived->addDecl(DerivedCtor);
if (ShouldDeleteSpecialMember(DerivedCtor, CXXDefaultConstructor, &ICI))
SetDeclDeleted(DerivedCtor, UsingLoc);
return DerivedCtor;
}
void Sema::NoteDeletedInheritingConstructor(CXXConstructorDecl *Ctor) {
InheritedConstructorInfo ICI(*this, Ctor->getLocation(),
Ctor->getInheritedConstructor().getShadowDecl());
ShouldDeleteSpecialMember(Ctor, CXXDefaultConstructor, &ICI,
/*Diagnose*/true);
}
void Sema::DefineInheritingConstructor(SourceLocation CurrentLocation,
CXXConstructorDecl *Constructor) {
CXXRecordDecl *ClassDecl = Constructor->getParent();
assert(Constructor->getInheritedConstructor() &&
!Constructor->doesThisDeclarationHaveABody() &&
!Constructor->isDeleted());
if (Constructor->willHaveBody() || Constructor->isInvalidDecl())
return;
// Initializations are performed "as if by a defaulted default constructor",
// so enter the appropriate scope.
SynthesizedFunctionScope Scope(*this, Constructor);
// The exception specification is needed because we are defining the
// function.
ResolveExceptionSpec(CurrentLocation,
Constructor->getType()->castAs<FunctionProtoType>());
MarkVTableUsed(CurrentLocation, ClassDecl);
// Add a context note for diagnostics produced after this point.
Scope.addContextNote(CurrentLocation);
ConstructorUsingShadowDecl *Shadow =
Constructor->getInheritedConstructor().getShadowDecl();
CXXConstructorDecl *InheritedCtor =
Constructor->getInheritedConstructor().getConstructor();
// [class.inhctor.init]p1:
// initialization proceeds as if a defaulted default constructor is used to
// initialize the D object and each base class subobject from which the
// constructor was inherited
InheritedConstructorInfo ICI(*this, CurrentLocation, Shadow);
CXXRecordDecl *RD = Shadow->getParent();
SourceLocation InitLoc = Shadow->getLocation();
// Build explicit initializers for all base classes from which the
// constructor was inherited.
SmallVector<CXXCtorInitializer*, 8> Inits;
for (bool VBase : {false, true}) {
for (CXXBaseSpecifier &B : VBase ? RD->vbases() : RD->bases()) {
if (B.isVirtual() != VBase)
continue;
auto *BaseRD = B.getType()->getAsCXXRecordDecl();
if (!BaseRD)
continue;
auto BaseCtor = ICI.findConstructorForBase(BaseRD, InheritedCtor);
if (!BaseCtor.first)
continue;
MarkFunctionReferenced(CurrentLocation, BaseCtor.first);
ExprResult Init = new (Context) CXXInheritedCtorInitExpr(
InitLoc, B.getType(), BaseCtor.first, VBase, BaseCtor.second);
auto *TInfo = Context.getTrivialTypeSourceInfo(B.getType(), InitLoc);
Inits.push_back(new (Context) CXXCtorInitializer(
Context, TInfo, VBase, InitLoc, Init.get(), InitLoc,
SourceLocation()));
}
}
// We now proceed as if for a defaulted default constructor, with the relevant
// initializers replaced.
if (SetCtorInitializers(Constructor, /*AnyErrors*/false, Inits)) {
Constructor->setInvalidDecl();
return;
}
Constructor->setBody(new (Context) CompoundStmt(InitLoc));
Constructor->markUsed(Context);
if (ASTMutationListener *L = getASTMutationListener()) {
L->CompletedImplicitDefinition(Constructor);
}
DiagnoseUninitializedFields(*this, Constructor);
}
CXXDestructorDecl *Sema::DeclareImplicitDestructor(CXXRecordDecl *ClassDecl) {
// C++ [class.dtor]p2:
// If a class has no user-declared destructor, a destructor is
// declared implicitly. An implicitly-declared destructor is an
// inline public member of its class.
assert(ClassDecl->needsImplicitDestructor());
DeclaringSpecialMember DSM(*this, ClassDecl, CXXDestructor);
if (DSM.isAlreadyBeingDeclared())
return nullptr;
bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
CXXDestructor,
false);
// Create the actual destructor declaration.
CanQualType ClassType
= Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
SourceLocation ClassLoc = ClassDecl->getLocation();
DeclarationName Name
= Context.DeclarationNames.getCXXDestructorName(ClassType);
DeclarationNameInfo NameInfo(Name, ClassLoc);
CXXDestructorDecl *Destructor = CXXDestructorDecl::Create(
Context, ClassDecl, ClassLoc, NameInfo, QualType(), nullptr,
getCurFPFeatures().isFPConstrained(),
/*isInline=*/true,
/*isImplicitlyDeclared=*/true,
Constexpr ? ConstexprSpecKind::Constexpr
: ConstexprSpecKind::Unspecified);
Destructor->setAccess(AS_public);
Destructor->setDefaulted();
if (getLangOpts().CUDA) {
inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDestructor,
Destructor,
/* ConstRHS */ false,
/* Diagnose */ false);
}
setupImplicitSpecialMemberType(Destructor, Context.VoidTy, None);
// We don't need to use SpecialMemberIsTrivial here; triviality for
// destructors is easy to compute.
Destructor->setTrivial(ClassDecl->hasTrivialDestructor());
Destructor->setTrivialForCall(ClassDecl->hasAttr<TrivialABIAttr>() ||
ClassDecl->hasTrivialDestructorForCall());
// Note that we have declared this destructor.
++getASTContext().NumImplicitDestructorsDeclared;
Scope *S = getScopeForContext(ClassDecl);
CheckImplicitSpecialMemberDeclaration(S, Destructor);
// We can't check whether an implicit destructor is deleted before we complete
// the definition of the class, because its validity depends on the alignment
// of the class. We'll check this from ActOnFields once the class is complete.
if (ClassDecl->isCompleteDefinition() &&
ShouldDeleteSpecialMember(Destructor, CXXDestructor))
SetDeclDeleted(Destructor, ClassLoc);
// Introduce this destructor into its scope.
if (S)
PushOnScopeChains(Destructor, S, false);
ClassDecl->addDecl(Destructor);
return Destructor;
}
void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation,
CXXDestructorDecl *Destructor) {
assert((Destructor->isDefaulted() &&
!Destructor->doesThisDeclarationHaveABody() &&
!Destructor->isDeleted()) &&
"DefineImplicitDestructor - call it for implicit default dtor");
if (Destructor->willHaveBody() || Destructor->isInvalidDecl())
return;
CXXRecordDecl *ClassDecl = Destructor->getParent();
assert(ClassDecl && "DefineImplicitDestructor - invalid destructor");
SynthesizedFunctionScope Scope(*this, Destructor);
// The exception specification is needed because we are defining the
// function.
ResolveExceptionSpec(CurrentLocation,
Destructor->getType()->castAs<FunctionProtoType>());
MarkVTableUsed(CurrentLocation, ClassDecl);
// Add a context note for diagnostics produced after this point.
Scope.addContextNote(CurrentLocation);
MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(),
Destructor->getParent());
if (CheckDestructor(Destructor)) {
Destructor->setInvalidDecl();
return;
}
SourceLocation Loc = Destructor->getEndLoc().isValid()
? Destructor->getEndLoc()
: Destructor->getLocation();
Destructor->setBody(new (Context) CompoundStmt(Loc));
Destructor->markUsed(Context);
if (ASTMutationListener *L = getASTMutationListener()) {
L->CompletedImplicitDefinition(Destructor);
}
}
void Sema::CheckCompleteDestructorVariant(SourceLocation CurrentLocation,
CXXDestructorDecl *Destructor) {
if (Destructor->isInvalidDecl())
return;
CXXRecordDecl *ClassDecl = Destructor->getParent();
assert(Context.getTargetInfo().getCXXABI().isMicrosoft() &&
"implicit complete dtors unneeded outside MS ABI");
assert(ClassDecl->getNumVBases() > 0 &&
"complete dtor only exists for classes with vbases");
SynthesizedFunctionScope Scope(*this, Destructor);
// Add a context note for diagnostics produced after this point.
Scope.addContextNote(CurrentLocation);
MarkVirtualBaseDestructorsReferenced(Destructor->getLocation(), ClassDecl);
}
/// Perform any semantic analysis which needs to be delayed until all
/// pending class member declarations have been parsed.
void Sema::ActOnFinishCXXMemberDecls() {
// If the context is an invalid C++ class, just suppress these checks.
if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(CurContext)) {
if (Record->isInvalidDecl()) {
DelayedOverridingExceptionSpecChecks.clear();
DelayedEquivalentExceptionSpecChecks.clear();
return;
}
checkForMultipleExportedDefaultConstructors(*this, Record);
}
}
void Sema::ActOnFinishCXXNonNestedClass() {
referenceDLLExportedClassMethods();
if (!DelayedDllExportMemberFunctions.empty()) {
SmallVector<CXXMethodDecl*, 4> WorkList;
std::swap(DelayedDllExportMemberFunctions, WorkList);
for (CXXMethodDecl *M : WorkList) {
DefineDefaultedFunction(*this, M, M->getLocation());
// Pass the method to the consumer to get emitted. This is not necessary
// for explicit instantiation definitions, as they will get emitted
// anyway.
if (M->getParent()->getTemplateSpecializationKind() !=
TSK_ExplicitInstantiationDefinition)
ActOnFinishInlineFunctionDef(M);
}
}
}
void Sema::referenceDLLExportedClassMethods() {
if (!DelayedDllExportClasses.empty()) {
// Calling ReferenceDllExportedMembers might cause the current function to
// be called again, so use a local copy of DelayedDllExportClasses.
SmallVector<CXXRecordDecl *, 4> WorkList;
std::swap(DelayedDllExportClasses, WorkList);
for (CXXRecordDecl *Class : WorkList)
ReferenceDllExportedMembers(*this, Class);
}
}
void Sema::AdjustDestructorExceptionSpec(CXXDestructorDecl *Destructor) {
assert(getLangOpts().CPlusPlus11 &&
"adjusting dtor exception specs was introduced in c++11");
if (Destructor->isDependentContext())
return;
// C++11 [class.dtor]p3:
// A declaration of a destructor that does not have an exception-
// specification is implicitly considered to have the same exception-
// specification as an implicit declaration.
const auto *DtorType = Destructor->getType()->castAs<FunctionProtoType>();
if (DtorType->hasExceptionSpec())