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//===--- SemaInit.cpp - Semantic Analysis for Initializers ----------------===//
//
// 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 initializers.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "clang/AST/ExprOpenMP.h"
#include "clang/AST/TypeLoc.h"
#include "clang/Basic/CharInfo.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Sema/Designator.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/SemaInternal.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
//===----------------------------------------------------------------------===//
// Sema Initialization Checking
//===----------------------------------------------------------------------===//
/// Check whether T is compatible with a wide character type (wchar_t,
/// char16_t or char32_t).
static bool IsWideCharCompatible(QualType T, ASTContext &Context) {
if (Context.typesAreCompatible(Context.getWideCharType(), T))
return true;
if (Context.getLangOpts().CPlusPlus || Context.getLangOpts().C11) {
return Context.typesAreCompatible(Context.Char16Ty, T) ||
Context.typesAreCompatible(Context.Char32Ty, T);
}
return false;
}
enum StringInitFailureKind {
SIF_None,
SIF_NarrowStringIntoWideChar,
SIF_WideStringIntoChar,
SIF_IncompatWideStringIntoWideChar,
SIF_UTF8StringIntoPlainChar,
SIF_PlainStringIntoUTF8Char,
SIF_Other
};
/// Check whether the array of type AT can be initialized by the Init
/// expression by means of string initialization. Returns SIF_None if so,
/// otherwise returns a StringInitFailureKind that describes why the
/// initialization would not work.
static StringInitFailureKind IsStringInit(Expr *Init, const ArrayType *AT,
ASTContext &Context) {
if (!isa<ConstantArrayType>(AT) && !isa<IncompleteArrayType>(AT))
return SIF_Other;
// See if this is a string literal or @encode.
Init = Init->IgnoreParens();
// Handle @encode, which is a narrow string.
if (isa<ObjCEncodeExpr>(Init) && AT->getElementType()->isCharType())
return SIF_None;
// Otherwise we can only handle string literals.
StringLiteral *SL = dyn_cast<StringLiteral>(Init);
if (!SL)
return SIF_Other;
const QualType ElemTy =
Context.getCanonicalType(AT->getElementType()).getUnqualifiedType();
switch (SL->getKind()) {
case StringLiteral::UTF8:
// char8_t array can be initialized with a UTF-8 string.
if (ElemTy->isChar8Type())
return SIF_None;
LLVM_FALLTHROUGH;
case StringLiteral::Ascii:
// char array can be initialized with a narrow string.
// Only allow char x[] = "foo"; not char x[] = L"foo";
if (ElemTy->isCharType())
return (SL->getKind() == StringLiteral::UTF8 &&
Context.getLangOpts().Char8)
? SIF_UTF8StringIntoPlainChar
: SIF_None;
if (ElemTy->isChar8Type())
return SIF_PlainStringIntoUTF8Char;
if (IsWideCharCompatible(ElemTy, Context))
return SIF_NarrowStringIntoWideChar;
return SIF_Other;
// C99 6.7.8p15 (with correction from DR343), or C11 6.7.9p15:
// "An array with element type compatible with a qualified or unqualified
// version of wchar_t, char16_t, or char32_t may be initialized by a wide
// string literal with the corresponding encoding prefix (L, u, or U,
// respectively), optionally enclosed in braces.
case StringLiteral::UTF16:
if (Context.typesAreCompatible(Context.Char16Ty, ElemTy))
return SIF_None;
if (ElemTy->isCharType() || ElemTy->isChar8Type())
return SIF_WideStringIntoChar;
if (IsWideCharCompatible(ElemTy, Context))
return SIF_IncompatWideStringIntoWideChar;
return SIF_Other;
case StringLiteral::UTF32:
if (Context.typesAreCompatible(Context.Char32Ty, ElemTy))
return SIF_None;
if (ElemTy->isCharType() || ElemTy->isChar8Type())
return SIF_WideStringIntoChar;
if (IsWideCharCompatible(ElemTy, Context))
return SIF_IncompatWideStringIntoWideChar;
return SIF_Other;
case StringLiteral::Wide:
if (Context.typesAreCompatible(Context.getWideCharType(), ElemTy))
return SIF_None;
if (ElemTy->isCharType() || ElemTy->isChar8Type())
return SIF_WideStringIntoChar;
if (IsWideCharCompatible(ElemTy, Context))
return SIF_IncompatWideStringIntoWideChar;
return SIF_Other;
}
llvm_unreachable("missed a StringLiteral kind?");
}
static StringInitFailureKind IsStringInit(Expr *init, QualType declType,
ASTContext &Context) {
const ArrayType *arrayType = Context.getAsArrayType(declType);
if (!arrayType)
return SIF_Other;
return IsStringInit(init, arrayType, Context);
}
bool Sema::IsStringInit(Expr *Init, const ArrayType *AT) {
return ::IsStringInit(Init, AT, Context) == SIF_None;
}
/// Update the type of a string literal, including any surrounding parentheses,
/// to match the type of the object which it is initializing.
static void updateStringLiteralType(Expr *E, QualType Ty) {
while (true) {
E->setType(Ty);
E->setValueKind(VK_RValue);
if (isa<StringLiteral>(E) || isa<ObjCEncodeExpr>(E)) {
break;
} else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
E = PE->getSubExpr();
} else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
assert(UO->getOpcode() == UO_Extension);
E = UO->getSubExpr();
} else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) {
E = GSE->getResultExpr();
} else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(E)) {
E = CE->getChosenSubExpr();
} else {
llvm_unreachable("unexpected expr in string literal init");
}
}
}
/// Fix a compound literal initializing an array so it's correctly marked
/// as an rvalue.
static void updateGNUCompoundLiteralRValue(Expr *E) {
while (true) {
E->setValueKind(VK_RValue);
if (isa<CompoundLiteralExpr>(E)) {
break;
} else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
E = PE->getSubExpr();
} else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
assert(UO->getOpcode() == UO_Extension);
E = UO->getSubExpr();
} else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) {
E = GSE->getResultExpr();
} else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(E)) {
E = CE->getChosenSubExpr();
} else {
llvm_unreachable("unexpected expr in array compound literal init");
}
}
}
static void CheckStringInit(Expr *Str, QualType &DeclT, const ArrayType *AT,
Sema &S) {
// Get the length of the string as parsed.
auto *ConstantArrayTy =
cast<ConstantArrayType>(Str->getType()->getAsArrayTypeUnsafe());
uint64_t StrLength = ConstantArrayTy->getSize().getZExtValue();
if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) {
// C99 6.7.8p14. We have an array of character type with unknown size
// being initialized to a string literal.
llvm::APInt ConstVal(32, StrLength);
// Return a new array type (C99 6.7.8p22).
DeclT = S.Context.getConstantArrayType(IAT->getElementType(),
ConstVal, nullptr,
ArrayType::Normal, 0);
updateStringLiteralType(Str, DeclT);
return;
}
const ConstantArrayType *CAT = cast<ConstantArrayType>(AT);
// We have an array of character type with known size. However,
// the size may be smaller or larger than the string we are initializing.
// FIXME: Avoid truncation for 64-bit length strings.
if (S.getLangOpts().CPlusPlus) {
if (StringLiteral *SL = dyn_cast<StringLiteral>(Str->IgnoreParens())) {
// For Pascal strings it's OK to strip off the terminating null character,
// so the example below is valid:
//
// unsigned char a[2] = "\pa";
if (SL->isPascal())
StrLength--;
}
// [dcl.init.string]p2
if (StrLength > CAT->getSize().getZExtValue())
S.Diag(Str->getBeginLoc(),
diag::err_initializer_string_for_char_array_too_long)
<< Str->getSourceRange();
} else {
// C99 6.7.8p14.
if (StrLength-1 > CAT->getSize().getZExtValue())
S.Diag(Str->getBeginLoc(),
diag::ext_initializer_string_for_char_array_too_long)
<< Str->getSourceRange();
}
// Set the type to the actual size that we are initializing. If we have
// something like:
// char x[1] = "foo";
// then this will set the string literal's type to char[1].
updateStringLiteralType(Str, DeclT);
}
//===----------------------------------------------------------------------===//
// Semantic checking for initializer lists.
//===----------------------------------------------------------------------===//
namespace {
/// Semantic checking for initializer lists.
///
/// The InitListChecker class contains a set of routines that each
/// handle the initialization of a certain kind of entity, e.g.,
/// arrays, vectors, struct/union types, scalars, etc. The
/// InitListChecker itself performs a recursive walk of the subobject
/// structure of the type to be initialized, while stepping through
/// the initializer list one element at a time. The IList and Index
/// parameters to each of the Check* routines contain the active
/// (syntactic) initializer list and the index into that initializer
/// list that represents the current initializer. Each routine is
/// responsible for moving that Index forward as it consumes elements.
///
/// Each Check* routine also has a StructuredList/StructuredIndex
/// arguments, which contains the current "structured" (semantic)
/// initializer list and the index into that initializer list where we
/// are copying initializers as we map them over to the semantic
/// list. Once we have completed our recursive walk of the subobject
/// structure, we will have constructed a full semantic initializer
/// list.
///
/// C99 designators cause changes in the initializer list traversal,
/// because they make the initialization "jump" into a specific
/// subobject and then continue the initialization from that
/// point. CheckDesignatedInitializer() recursively steps into the
/// designated subobject and manages backing out the recursion to
/// initialize the subobjects after the one designated.
///
/// If an initializer list contains any designators, we build a placeholder
/// structured list even in 'verify only' mode, so that we can track which
/// elements need 'empty' initializtion.
class InitListChecker {
Sema &SemaRef;
bool hadError = false;
bool VerifyOnly; // No diagnostics.
bool TreatUnavailableAsInvalid; // Used only in VerifyOnly mode.
bool InOverloadResolution;
InitListExpr *FullyStructuredList = nullptr;
NoInitExpr *DummyExpr = nullptr;
NoInitExpr *getDummyInit() {
if (!DummyExpr)
DummyExpr = new (SemaRef.Context) NoInitExpr(SemaRef.Context.VoidTy);
return DummyExpr;
}
void CheckImplicitInitList(const InitializedEntity &Entity,
InitListExpr *ParentIList, QualType T,
unsigned &Index, InitListExpr *StructuredList,
unsigned &StructuredIndex);
void CheckExplicitInitList(const InitializedEntity &Entity,
InitListExpr *IList, QualType &T,
InitListExpr *StructuredList,
bool TopLevelObject = false);
void CheckListElementTypes(const InitializedEntity &Entity,
InitListExpr *IList, QualType &DeclType,
bool SubobjectIsDesignatorContext,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool TopLevelObject = false);
void CheckSubElementType(const InitializedEntity &Entity,
InitListExpr *IList, QualType ElemType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool DirectlyDesignated = false);
void CheckComplexType(const InitializedEntity &Entity,
InitListExpr *IList, QualType DeclType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex);
void CheckScalarType(const InitializedEntity &Entity,
InitListExpr *IList, QualType DeclType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex);
void CheckReferenceType(const InitializedEntity &Entity,
InitListExpr *IList, QualType DeclType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex);
void CheckVectorType(const InitializedEntity &Entity,
InitListExpr *IList, QualType DeclType, unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex);
void CheckStructUnionTypes(const InitializedEntity &Entity,
InitListExpr *IList, QualType DeclType,
CXXRecordDecl::base_class_range Bases,
RecordDecl::field_iterator Field,
bool SubobjectIsDesignatorContext, unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool TopLevelObject = false);
void CheckArrayType(const InitializedEntity &Entity,
InitListExpr *IList, QualType &DeclType,
llvm::APSInt elementIndex,
bool SubobjectIsDesignatorContext, unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex);
bool CheckDesignatedInitializer(const InitializedEntity &Entity,
InitListExpr *IList, DesignatedInitExpr *DIE,
unsigned DesigIdx,
QualType &CurrentObjectType,
RecordDecl::field_iterator *NextField,
llvm::APSInt *NextElementIndex,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool FinishSubobjectInit,
bool TopLevelObject);
InitListExpr *getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
QualType CurrentObjectType,
InitListExpr *StructuredList,
unsigned StructuredIndex,
SourceRange InitRange,
bool IsFullyOverwritten = false);
void UpdateStructuredListElement(InitListExpr *StructuredList,
unsigned &StructuredIndex,
Expr *expr);
InitListExpr *createInitListExpr(QualType CurrentObjectType,
SourceRange InitRange,
unsigned ExpectedNumInits);
int numArrayElements(QualType DeclType);
int numStructUnionElements(QualType DeclType);
ExprResult PerformEmptyInit(SourceLocation Loc,
const InitializedEntity &Entity);
/// Diagnose that OldInit (or part thereof) has been overridden by NewInit.
void diagnoseInitOverride(Expr *OldInit, SourceRange NewInitRange,
bool FullyOverwritten = true) {
// Overriding an initializer via a designator is valid with C99 designated
// initializers, but ill-formed with C++20 designated initializers.
unsigned DiagID = SemaRef.getLangOpts().CPlusPlus
? diag::ext_initializer_overrides
: diag::warn_initializer_overrides;
if (InOverloadResolution && SemaRef.getLangOpts().CPlusPlus) {
// In overload resolution, we have to strictly enforce the rules, and so
// don't allow any overriding of prior initializers. This matters for a
// case such as:
//
// union U { int a, b; };
// struct S { int a, b; };
// void f(U), f(S);
//
// Here, f({.a = 1, .b = 2}) is required to call the struct overload. For
// consistency, we disallow all overriding of prior initializers in
// overload resolution, not only overriding of union members.
hadError = true;
} else if (OldInit->getType().isDestructedType() && !FullyOverwritten) {
// If we'll be keeping around the old initializer but overwriting part of
// the object it initialized, and that object is not trivially
// destructible, this can leak. Don't allow that, not even as an
// extension.
//
// FIXME: It might be reasonable to allow this in cases where the part of
// the initializer that we're overriding has trivial destruction.
DiagID = diag::err_initializer_overrides_destructed;
} else if (!OldInit->getSourceRange().isValid()) {
// We need to check on source range validity because the previous
// initializer does not have to be an explicit initializer. e.g.,
//
// struct P { int a, b; };
// struct PP { struct P p } l = { { .a = 2 }, .p.b = 3 };
//
// There is an overwrite taking place because the first braced initializer
// list "{ .a = 2 }" already provides value for .p.b (which is zero).
//
// Such overwrites are harmless, so we don't diagnose them. (Note that in
// C++, this cannot be reached unless we've already seen and diagnosed a
// different conformance issue, such as a mixture of designated and
// non-designated initializers or a multi-level designator.)
return;
}
if (!VerifyOnly) {
SemaRef.Diag(NewInitRange.getBegin(), DiagID)
<< NewInitRange << FullyOverwritten << OldInit->getType();
SemaRef.Diag(OldInit->getBeginLoc(), diag::note_previous_initializer)
<< (OldInit->HasSideEffects(SemaRef.Context) && FullyOverwritten)
<< OldInit->getSourceRange();
}
}
// Explanation on the "FillWithNoInit" mode:
//
// Assume we have the following definitions (Case#1):
// struct P { char x[6][6]; } xp = { .x[1] = "bar" };
// struct PP { struct P lp; } l = { .lp = xp, .lp.x[1][2] = 'f' };
//
// l.lp.x[1][0..1] should not be filled with implicit initializers because the
// "base" initializer "xp" will provide values for them; l.lp.x[1] will be "baf".
//
// But if we have (Case#2):
// struct PP l = { .lp = xp, .lp.x[1] = { [2] = 'f' } };
//
// l.lp.x[1][0..1] are implicitly initialized and do not use values from the
// "base" initializer; l.lp.x[1] will be "\0\0f\0\0\0".
//
// To distinguish Case#1 from Case#2, and also to avoid leaving many "holes"
// in the InitListExpr, the "holes" in Case#1 are filled not with empty
// initializers but with special "NoInitExpr" place holders, which tells the
// CodeGen not to generate any initializers for these parts.
void FillInEmptyInitForBase(unsigned Init, const CXXBaseSpecifier &Base,
const InitializedEntity &ParentEntity,
InitListExpr *ILE, bool &RequiresSecondPass,
bool FillWithNoInit);
void FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
const InitializedEntity &ParentEntity,
InitListExpr *ILE, bool &RequiresSecondPass,
bool FillWithNoInit = false);
void FillInEmptyInitializations(const InitializedEntity &Entity,
InitListExpr *ILE, bool &RequiresSecondPass,
InitListExpr *OuterILE, unsigned OuterIndex,
bool FillWithNoInit = false);
bool CheckFlexibleArrayInit(const InitializedEntity &Entity,
Expr *InitExpr, FieldDecl *Field,
bool TopLevelObject);
void CheckEmptyInitializable(const InitializedEntity &Entity,
SourceLocation Loc);
public:
InitListChecker(Sema &S, const InitializedEntity &Entity, InitListExpr *IL,
QualType &T, bool VerifyOnly, bool TreatUnavailableAsInvalid,
bool InOverloadResolution = false);
bool HadError() { return hadError; }
// Retrieves the fully-structured initializer list used for
// semantic analysis and code generation.
InitListExpr *getFullyStructuredList() const { return FullyStructuredList; }
};
} // end anonymous namespace
ExprResult InitListChecker::PerformEmptyInit(SourceLocation Loc,
const InitializedEntity &Entity) {
InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc,
true);
MultiExprArg SubInit;
Expr *InitExpr;
InitListExpr DummyInitList(SemaRef.Context, Loc, None, Loc);
// C++ [dcl.init.aggr]p7:
// If there are fewer initializer-clauses in the list than there are
// members in the aggregate, then each member not explicitly initialized
// ...
bool EmptyInitList = SemaRef.getLangOpts().CPlusPlus11 &&
Entity.getType()->getBaseElementTypeUnsafe()->isRecordType();
if (EmptyInitList) {
// C++1y / DR1070:
// shall be initialized [...] from an empty initializer list.
//
// We apply the resolution of this DR to C++11 but not C++98, since C++98
// does not have useful semantics for initialization from an init list.
// We treat this as copy-initialization, because aggregate initialization
// always performs copy-initialization on its elements.
//
// Only do this if we're initializing a class type, to avoid filling in
// the initializer list where possible.
InitExpr = VerifyOnly ? &DummyInitList : new (SemaRef.Context)
InitListExpr(SemaRef.Context, Loc, None, Loc);
InitExpr->setType(SemaRef.Context.VoidTy);
SubInit = InitExpr;
Kind = InitializationKind::CreateCopy(Loc, Loc);
} else {
// C++03:
// shall be value-initialized.
}
InitializationSequence InitSeq(SemaRef, Entity, Kind, SubInit);
// libstdc++4.6 marks the vector default constructor as explicit in
// _GLIBCXX_DEBUG mode, so recover using the C++03 logic in that case.
// stlport does so too. Look for std::__debug for libstdc++, and for
// std:: for stlport. This is effectively a compiler-side implementation of
// LWG2193.
if (!InitSeq && EmptyInitList && InitSeq.getFailureKind() ==
InitializationSequence::FK_ExplicitConstructor) {
OverloadCandidateSet::iterator Best;
OverloadingResult O =
InitSeq.getFailedCandidateSet()
.BestViableFunction(SemaRef, Kind.getLocation(), Best);
(void)O;
assert(O == OR_Success && "Inconsistent overload resolution");
CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
CXXRecordDecl *R = CtorDecl->getParent();
if (CtorDecl->getMinRequiredArguments() == 0 &&
CtorDecl->isExplicit() && R->getDeclName() &&
SemaRef.SourceMgr.isInSystemHeader(CtorDecl->getLocation())) {
bool IsInStd = false;
for (NamespaceDecl *ND = dyn_cast<NamespaceDecl>(R->getDeclContext());
ND && !IsInStd; ND = dyn_cast<NamespaceDecl>(ND->getParent())) {
if (SemaRef.getStdNamespace()->InEnclosingNamespaceSetOf(ND))
IsInStd = true;
}
if (IsInStd && llvm::StringSwitch<bool>(R->getName())
.Cases("basic_string", "deque", "forward_list", true)
.Cases("list", "map", "multimap", "multiset", true)
.Cases("priority_queue", "queue", "set", "stack", true)
.Cases("unordered_map", "unordered_set", "vector", true)
.Default(false)) {
InitSeq.InitializeFrom(
SemaRef, Entity,
InitializationKind::CreateValue(Loc, Loc, Loc, true),
MultiExprArg(), /*TopLevelOfInitList=*/false,
TreatUnavailableAsInvalid);
// Emit a warning for this. System header warnings aren't shown
// by default, but people working on system headers should see it.
if (!VerifyOnly) {
SemaRef.Diag(CtorDecl->getLocation(),
diag::warn_invalid_initializer_from_system_header);
if (Entity.getKind() == InitializedEntity::EK_Member)
SemaRef.Diag(Entity.getDecl()->getLocation(),
diag::note_used_in_initialization_here);
else if (Entity.getKind() == InitializedEntity::EK_ArrayElement)
SemaRef.Diag(Loc, diag::note_used_in_initialization_here);
}
}
}
}
if (!InitSeq) {
if (!VerifyOnly) {
InitSeq.Diagnose(SemaRef, Entity, Kind, SubInit);
if (Entity.getKind() == InitializedEntity::EK_Member)
SemaRef.Diag(Entity.getDecl()->getLocation(),
diag::note_in_omitted_aggregate_initializer)
<< /*field*/1 << Entity.getDecl();
else if (Entity.getKind() == InitializedEntity::EK_ArrayElement) {
bool IsTrailingArrayNewMember =
Entity.getParent() &&
Entity.getParent()->isVariableLengthArrayNew();
SemaRef.Diag(Loc, diag::note_in_omitted_aggregate_initializer)
<< (IsTrailingArrayNewMember ? 2 : /*array element*/0)
<< Entity.getElementIndex();
}
}
hadError = true;
return ExprError();
}
return VerifyOnly ? ExprResult()
: InitSeq.Perform(SemaRef, Entity, Kind, SubInit);
}
void InitListChecker::CheckEmptyInitializable(const InitializedEntity &Entity,
SourceLocation Loc) {
// If we're building a fully-structured list, we'll check this at the end
// once we know which elements are actually initialized. Otherwise, we know
// that there are no designators so we can just check now.
if (FullyStructuredList)
return;
PerformEmptyInit(Loc, Entity);
}
void InitListChecker::FillInEmptyInitForBase(
unsigned Init, const CXXBaseSpecifier &Base,
const InitializedEntity &ParentEntity, InitListExpr *ILE,
bool &RequiresSecondPass, bool FillWithNoInit) {
InitializedEntity BaseEntity = InitializedEntity::InitializeBase(
SemaRef.Context, &Base, false, &ParentEntity);
if (Init >= ILE->getNumInits() || !ILE->getInit(Init)) {
ExprResult BaseInit = FillWithNoInit
? new (SemaRef.Context) NoInitExpr(Base.getType())
: PerformEmptyInit(ILE->getEndLoc(), BaseEntity);
if (BaseInit.isInvalid()) {
hadError = true;
return;
}
if (!VerifyOnly) {
assert(Init < ILE->getNumInits() && "should have been expanded");
ILE->setInit(Init, BaseInit.getAs<Expr>());
}
} else if (InitListExpr *InnerILE =
dyn_cast<InitListExpr>(ILE->getInit(Init))) {
FillInEmptyInitializations(BaseEntity, InnerILE, RequiresSecondPass,
ILE, Init, FillWithNoInit);
} else if (DesignatedInitUpdateExpr *InnerDIUE =
dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init))) {
FillInEmptyInitializations(BaseEntity, InnerDIUE->getUpdater(),
RequiresSecondPass, ILE, Init,
/*FillWithNoInit =*/true);
}
}
void InitListChecker::FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
const InitializedEntity &ParentEntity,
InitListExpr *ILE,
bool &RequiresSecondPass,
bool FillWithNoInit) {
SourceLocation Loc = ILE->getEndLoc();
unsigned NumInits = ILE->getNumInits();
InitializedEntity MemberEntity
= InitializedEntity::InitializeMember(Field, &ParentEntity);
if (Init >= NumInits || !ILE->getInit(Init)) {
if (const RecordType *RType = ILE->getType()->getAs<RecordType>())
if (!RType->getDecl()->isUnion())
assert((Init < NumInits || VerifyOnly) &&
"This ILE should have been expanded");
if (FillWithNoInit) {
assert(!VerifyOnly && "should not fill with no-init in verify-only mode");
Expr *Filler = new (SemaRef.Context) NoInitExpr(Field->getType());
if (Init < NumInits)
ILE->setInit(Init, Filler);
else
ILE->updateInit(SemaRef.Context, Init, Filler);
return;
}
// C++1y [dcl.init.aggr]p7:
// If there are fewer initializer-clauses in the list than there are
// members in the aggregate, then each member not explicitly initialized
// shall be initialized from its brace-or-equal-initializer [...]
if (Field->hasInClassInitializer()) {
if (VerifyOnly)
return;
ExprResult DIE = SemaRef.BuildCXXDefaultInitExpr(Loc, Field);
if (DIE.isInvalid()) {
hadError = true;
return;
}
SemaRef.checkInitializerLifetime(MemberEntity, DIE.get());
if (Init < NumInits)
ILE->setInit(Init, DIE.get());
else {
ILE->updateInit(SemaRef.Context, Init, DIE.get());
RequiresSecondPass = true;
}
return;
}
if (Field->getType()->isReferenceType()) {
if (!VerifyOnly) {
// C++ [dcl.init.aggr]p9:
// If an incomplete or empty initializer-list leaves a
// member of reference type uninitialized, the program is
// ill-formed.
SemaRef.Diag(Loc, diag::err_init_reference_member_uninitialized)
<< Field->getType()
<< ILE->getSyntacticForm()->getSourceRange();
SemaRef.Diag(Field->getLocation(),
diag::note_uninit_reference_member);
}
hadError = true;
return;
}
ExprResult MemberInit = PerformEmptyInit(Loc, MemberEntity);
if (MemberInit.isInvalid()) {
hadError = true;
return;
}
if (hadError || VerifyOnly) {
// Do nothing
} else if (Init < NumInits) {
ILE->setInit(Init, MemberInit.getAs<Expr>());
} else if (!isa<ImplicitValueInitExpr>(MemberInit.get())) {
// Empty initialization requires a constructor call, so
// extend the initializer list to include the constructor
// call and make a note that we'll need to take another pass
// through the initializer list.
ILE->updateInit(SemaRef.Context, Init, MemberInit.getAs<Expr>());
RequiresSecondPass = true;
}
} else if (InitListExpr *InnerILE
= dyn_cast<InitListExpr>(ILE->getInit(Init))) {
FillInEmptyInitializations(MemberEntity, InnerILE,
RequiresSecondPass, ILE, Init, FillWithNoInit);
} else if (DesignatedInitUpdateExpr *InnerDIUE =
dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init))) {
FillInEmptyInitializations(MemberEntity, InnerDIUE->getUpdater(),
RequiresSecondPass, ILE, Init,
/*FillWithNoInit =*/true);
}
}
/// Recursively replaces NULL values within the given initializer list
/// with expressions that perform value-initialization of the
/// appropriate type, and finish off the InitListExpr formation.
void
InitListChecker::FillInEmptyInitializations(const InitializedEntity &Entity,
InitListExpr *ILE,
bool &RequiresSecondPass,
InitListExpr *OuterILE,
unsigned OuterIndex,
bool FillWithNoInit) {
assert((ILE->getType() != SemaRef.Context.VoidTy) &&
"Should not have void type");
// We don't need to do any checks when just filling NoInitExprs; that can't
// fail.
if (FillWithNoInit && VerifyOnly)
return;
// If this is a nested initializer list, we might have changed its contents
// (and therefore some of its properties, such as instantiation-dependence)
// while filling it in. Inform the outer initializer list so that its state
// can be updated to match.
// FIXME: We should fully build the inner initializers before constructing
// the outer InitListExpr instead of mutating AST nodes after they have
// been used as subexpressions of other nodes.
struct UpdateOuterILEWithUpdatedInit {
InitListExpr *Outer;
unsigned OuterIndex;
~UpdateOuterILEWithUpdatedInit() {
if (Outer)
Outer->setInit(OuterIndex, Outer->getInit(OuterIndex));
}
} UpdateOuterRAII = {OuterILE, OuterIndex};
// A transparent ILE is not performing aggregate initialization and should
// not be filled in.
if (ILE->isTransparent())
return;
if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) {
const RecordDecl *RDecl = RType->getDecl();
if (RDecl->isUnion() && ILE->getInitializedFieldInUnion())
FillInEmptyInitForField(0, ILE->getInitializedFieldInUnion(),
Entity, ILE, RequiresSecondPass, FillWithNoInit);
else if (RDecl->isUnion() && isa<CXXRecordDecl>(RDecl) &&
cast<CXXRecordDecl>(RDecl)->hasInClassInitializer()) {
for (auto *Field : RDecl->fields()) {
if (Field->hasInClassInitializer()) {
FillInEmptyInitForField(0, Field, Entity, ILE, RequiresSecondPass,
FillWithNoInit);
break;
}
}
} else {
// The fields beyond ILE->getNumInits() are default initialized, so in
// order to leave them uninitialized, the ILE is expanded and the extra
// fields are then filled with NoInitExpr.
unsigned NumElems = numStructUnionElements(ILE->getType());
if (RDecl->hasFlexibleArrayMember())
++NumElems;
if (!VerifyOnly && ILE->getNumInits() < NumElems)
ILE->resizeInits(SemaRef.Context, NumElems);
unsigned Init = 0;
if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RDecl)) {
for (auto &Base : CXXRD->bases()) {
if (hadError)
return;
FillInEmptyInitForBase(Init, Base, Entity, ILE, RequiresSecondPass,
FillWithNoInit);
++Init;
}
}
for (auto *Field : RDecl->fields()) {
if (Field->isUnnamedBitfield())
continue;
if (hadError)
return;
FillInEmptyInitForField(Init, Field, Entity, ILE, RequiresSecondPass,
FillWithNoInit);
if (hadError)
return;
++Init;
// Only look at the first initialization of a union.
if (RDecl->isUnion())
break;
}
}
return;
}
QualType ElementType;
InitializedEntity ElementEntity = Entity;
unsigned NumInits = ILE->getNumInits();
unsigned NumElements = NumInits;
if (const ArrayType *AType = SemaRef.Context.getAsArrayType(ILE->getType())) {
ElementType = AType->getElementType();
if (const auto *CAType = dyn_cast<ConstantArrayType>(AType))
NumElements = CAType->getSize().getZExtValue();
// For an array new with an unknown bound, ask for one additional element
// in order to populate the array filler.
if (Entity.isVariableLengthArrayNew())
++NumElements;
ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context,
0, Entity);
} else if (const VectorType *VType = ILE->getType()->getAs<VectorType>()) {
ElementType = VType->getElementType();
NumElements = VType->getNumElements();
ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context,
0, Entity);
} else
ElementType = ILE->getType();
bool SkipEmptyInitChecks = false;
for (unsigned Init = 0; Init != NumElements; ++Init) {
if (hadError)
return;
if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement ||
ElementEntity.getKind() == InitializedEntity::EK_VectorElement)
ElementEntity.setElementIndex(Init);
if (Init >= NumInits && (ILE->hasArrayFiller() || SkipEmptyInitChecks))
return;
Expr *InitExpr = (Init < NumInits ? ILE->getInit(Init) : nullptr);
if (!InitExpr && Init < NumInits && ILE->hasArrayFiller())
ILE->setInit(Init, ILE->getArrayFiller());
else if (!InitExpr && !ILE->hasArrayFiller()) {
// In VerifyOnly mode, there's no point performing empty initialization
// more than once.
if (SkipEmptyInitChecks)
continue;
Expr *Filler = nullptr;
if (FillWithNoInit)
Filler = new (SemaRef.Context) NoInitExpr(ElementType);
else {
ExprResult ElementInit =
PerformEmptyInit(ILE->getEndLoc(), ElementEntity);
if (ElementInit.isInvalid()) {
hadError = true;
return;
}
Filler = ElementInit.getAs<Expr>();
}
if (hadError) {
// Do nothing
} else if (VerifyOnly) {
SkipEmptyInitChecks = true;
} else if (Init < NumInits) {
// For arrays, just set the expression used for value-initialization
// of the "holes" in the array.
if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement)
ILE->setArrayFiller(Filler);
else
ILE->setInit(Init, Filler);
} else {
// For arrays, just set the expression used for value-initialization
// of the rest of elements and exit.
if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement) {
ILE->setArrayFiller(Filler);
return;
}
if (!isa<ImplicitValueInitExpr>(Filler) && !isa<NoInitExpr>(Filler)) {
// Empty initialization requires a constructor call, so
// extend the initializer list to include the constructor
// call and make a note that we'll need to take another pass
// through the initializer list.
ILE->updateInit(SemaRef.Context, Init, Filler);
RequiresSecondPass = true;
}
}
} else if (InitListExpr *InnerILE
= dyn_cast_or_null<InitListExpr>(InitExpr)) {
FillInEmptyInitializations(ElementEntity, InnerILE, RequiresSecondPass,
ILE, Init, FillWithNoInit);
} else if (DesignatedInitUpdateExpr *InnerDIUE =
dyn_cast_or_null<DesignatedInitUpdateExpr>(InitExpr)) {
FillInEmptyInitializations(ElementEntity, InnerDIUE->getUpdater(),
RequiresSecondPass, ILE, Init,
/*FillWithNoInit =*/true);
}
}
}
static bool hasAnyDesignatedInits(const InitListExpr *IL) {
for (const Stmt *Init : *IL)
if (Init && isa<DesignatedInitExpr>(Init))
return true;
return false;
}
InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity,
InitListExpr *IL, QualType &T, bool VerifyOnly,
bool TreatUnavailableAsInvalid,
bool InOverloadResolution)
: SemaRef(S), VerifyOnly(VerifyOnly),
TreatUnavailableAsInvalid(TreatUnavailableAsInvalid),
InOverloadResolution(InOverloadResolution) {
if (!VerifyOnly || hasAnyDesignatedInits(IL)) {
FullyStructuredList =
createInitListExpr(T, IL->getSourceRange(), IL->getNumInits());
// FIXME: Check that IL isn't already the semantic form of some other
// InitListExpr. If it is, we'd create a broken AST.
if (!VerifyOnly)
FullyStructuredList->setSyntacticForm(IL);
}
CheckExplicitInitList(Entity, IL, T, FullyStructuredList,
/*TopLevelObject=*/true);
if (!hadError && FullyStructuredList) {
bool RequiresSecondPass = false;
FillInEmptyInitializations(Entity, FullyStructuredList, RequiresSecondPass,
/*OuterILE=*/nullptr, /*OuterIndex=*/0);
if (RequiresSecondPass && !hadError)
FillInEmptyInitializations(Entity, FullyStructuredList,
RequiresSecondPass, nullptr, 0);
}
if (hadError && FullyStructuredList)
FullyStructuredList->markError();
}
int InitListChecker::numArrayElements(QualType DeclType) {
// FIXME: use a proper constant
int maxElements = 0x7FFFFFFF;
if (const ConstantArrayType *CAT =
SemaRef.Context.getAsConstantArrayType(DeclType)) {
maxElements = static_cast<int>(CAT->getSize().getZExtValue());
}
return maxElements;
}
int InitListChecker::numStructUnionElements(QualType DeclType) {
RecordDecl *structDecl = DeclType->castAs<RecordType>()->getDecl();
int InitializableMembers = 0;
if (auto *CXXRD = dyn_cast<CXXRecordDecl>(structDecl))
InitializableMembers += CXXRD->getNumBases();
for (const auto *Field : structDecl->fields())
if (!Field->isUnnamedBitfield())
++InitializableMembers;
if (structDecl->isUnion())
return std::min(InitializableMembers, 1);
return InitializableMembers - structDecl->hasFlexibleArrayMember();
}
/// Determine whether Entity is an entity for which it is idiomatic to elide
/// the braces in aggregate initialization.
static bool isIdiomaticBraceElisionEntity(const InitializedEntity &Entity) {
// Recursive initialization of the one and only field within an aggregate
// class is considered idiomatic. This case arises in particular for
// initialization of std::array, where the C++ standard suggests the idiom of
//
// std::array<T, N> arr = {1, 2, 3};
//
// (where std::array is an aggregate struct containing a single array field.
// FIXME: Should aggregate initialization of a struct with a single
// base class and no members also suppress the warning?
if (Entity.getKind() != InitializedEntity::EK_Member || !Entity.getParent())
return false;
auto *ParentRD =
Entity.getParent()->getType()->castAs<RecordType>()->getDecl();
if (CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(ParentRD))
if (CXXRD->getNumBases())
return false;
auto FieldIt = ParentRD->field_begin();
assert(FieldIt != ParentRD->field_end() &&
"no fields but have initializer for member?");
return ++FieldIt == ParentRD->field_end();
}
/// Check whether the range of the initializer \p ParentIList from element
/// \p Index onwards can be used to initialize an object of type \p T. Update
/// \p Index to indicate how many elements of the list were consumed.
///
/// This also fills in \p StructuredList, from element \p StructuredIndex
/// onwards, with the fully-braced, desugared form of the initialization.
void InitListChecker::CheckImplicitInitList(const InitializedEntity &Entity,
InitListExpr *ParentIList,
QualType T, unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex) {
int maxElements = 0;
if (T->isArrayType())
maxElements = numArrayElements(T);
else if (T->isRecordType())
maxElements = numStructUnionElements(T);
else if (T->isVectorType())
maxElements = T->castAs<VectorType>()->getNumElements();
else
llvm_unreachable("CheckImplicitInitList(): Illegal type");
if (maxElements == 0) {
if (!VerifyOnly)
SemaRef.Diag(ParentIList->getInit(Index)->getBeginLoc(),
diag::err_implicit_empty_initializer);
++Index;
hadError = true;
return;
}
// Build a structured initializer list corresponding to this subobject.
InitListExpr *StructuredSubobjectInitList = getStructuredSubobjectInit(
ParentIList, Index, T, StructuredList, StructuredIndex,
SourceRange(ParentIList->getInit(Index)->getBeginLoc(),
ParentIList->getSourceRange().getEnd()));
unsigned StructuredSubobjectInitIndex = 0;
// Check the element types and build the structural subobject.
unsigned StartIndex = Index;
CheckListElementTypes(Entity, ParentIList, T,
/*SubobjectIsDesignatorContext=*/false, Index,
StructuredSubobjectInitList,
StructuredSubobjectInitIndex);
if (StructuredSubobjectInitList) {
StructuredSubobjectInitList->setType(T);
unsigned EndIndex = (Index == StartIndex? StartIndex : Index - 1);
// Update the structured sub-object initializer so that it's ending
// range corresponds with the end of the last initializer it used.
if (EndIndex < ParentIList->getNumInits() &&
ParentIList->getInit(EndIndex)) {
SourceLocation EndLoc
= ParentIList->getInit(EndIndex)->getSourceRange().getEnd();
StructuredSubobjectInitList->setRBraceLoc(EndLoc);
}
// Complain about missing braces.
if (!VerifyOnly && (T->isArrayType() || T->isRecordType()) &&
!ParentIList->isIdiomaticZeroInitializer(SemaRef.getLangOpts()) &&
!isIdiomaticBraceElisionEntity(Entity)) {
SemaRef.Diag(StructuredSubobjectInitList->getBeginLoc(),
diag::warn_missing_braces)
<< StructuredSubobjectInitList->getSourceRange()
<< FixItHint::CreateInsertion(
StructuredSubobjectInitList->getBeginLoc(), "{")
<< FixItHint::CreateInsertion(
SemaRef.getLocForEndOfToken(
StructuredSubobjectInitList->getEndLoc()),
"}");
}
// Warn if this type won't be an aggregate in future versions of C++.
auto *CXXRD = T->getAsCXXRecordDecl();
if (!VerifyOnly && CXXRD && CXXRD->hasUserDeclaredConstructor()) {
SemaRef.Diag(StructuredSubobjectInitList->getBeginLoc(),
diag::warn_cxx20_compat_aggregate_init_with_ctors)
<< StructuredSubobjectInitList->getSourceRange() << T;
}
}
}
/// Warn that \p Entity was of scalar type and was initialized by a
/// single-element braced initializer list.
static void warnBracedScalarInit(Sema &S, const InitializedEntity &Entity,
SourceRange Braces) {
// Don't warn during template instantiation. If the initialization was
// non-dependent, we warned during the initial parse; otherwise, the
// type might not be scalar in some uses of the template.
if (S.inTemplateInstantiation())
return;
unsigned DiagID = 0;
switch (Entity.getKind()) {
case InitializedEntity::EK_VectorElement:
case InitializedEntity::EK_ComplexElement:
case InitializedEntity::EK_ArrayElement:
case InitializedEntity::EK_Parameter:
case InitializedEntity::EK_Parameter_CF_Audited:
case InitializedEntity::EK_TemplateParameter:
case InitializedEntity::EK_Result:
// Extra braces here are suspicious.
DiagID = diag::warn_braces_around_init;
break;
case InitializedEntity::EK_Member:
// Warn on aggregate initialization but not on ctor init list or
// default member initializer.
if (Entity.getParent())
DiagID = diag::warn_braces_around_init;
break;
case InitializedEntity::EK_Variable:
case InitializedEntity::EK_LambdaCapture:
// No warning, might be direct-list-initialization.
// FIXME: Should we warn for copy-list-initialization in these cases?
break;
case InitializedEntity::EK_New:
case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_CompoundLiteralInit:
// No warning, braces are part of the syntax of the underlying construct.
break;
case InitializedEntity::EK_RelatedResult:
// No warning, we already warned when initializing the result.
break;
case InitializedEntity::EK_Exception:
case InitializedEntity::EK_Base:
case InitializedEntity::EK_Delegating:
case InitializedEntity::EK_BlockElement:
case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
case InitializedEntity::EK_Binding:
case InitializedEntity::EK_StmtExprResult:
llvm_unreachable("unexpected braced scalar init");
}
if (DiagID) {
S.Diag(Braces.getBegin(), DiagID)
<< Entity.getType()->isSizelessBuiltinType() << Braces
<< FixItHint::CreateRemoval(Braces.getBegin())
<< FixItHint::CreateRemoval(Braces.getEnd());
}
}
/// Check whether the initializer \p IList (that was written with explicit
/// braces) can be used to initialize an object of type \p T.
///
/// This also fills in \p StructuredList with the fully-braced, desugared
/// form of the initialization.
void InitListChecker::CheckExplicitInitList(const InitializedEntity &Entity,
InitListExpr *IList, QualType &T,
InitListExpr *StructuredList,
bool TopLevelObject) {
unsigned Index = 0, StructuredIndex = 0;
CheckListElementTypes(Entity, IList, T, /*SubobjectIsDesignatorContext=*/true,
Index, StructuredList, StructuredIndex, TopLevelObject);
if (StructuredList) {
QualType ExprTy = T;
if (!ExprTy->isArrayType())
ExprTy = ExprTy.getNonLValueExprType(SemaRef.Context);
if (!VerifyOnly)
IList->setType(ExprTy);
StructuredList->setType(ExprTy);
}
if (hadError)
return;
// Don't complain for incomplete types, since we'll get an error elsewhere.
if (Index < IList->getNumInits() && !T->isIncompleteType()) {
// We have leftover initializers
bool ExtraInitsIsError = SemaRef.getLangOpts().CPlusPlus ||
(SemaRef.getLangOpts().OpenCL && T->isVectorType());
hadError = ExtraInitsIsError;
if (VerifyOnly) {
return;
} else if (StructuredIndex == 1 &&
IsStringInit(StructuredList->getInit(0), T, SemaRef.Context) ==
SIF_None) {
unsigned DK =
ExtraInitsIsError
? diag::err_excess_initializers_in_char_array_initializer
: diag::ext_excess_initializers_in_char_array_initializer;
SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
<< IList->getInit(Index)->getSourceRange();
} else if (T->isSizelessBuiltinType()) {
unsigned DK = ExtraInitsIsError
? diag::err_excess_initializers_for_sizeless_type
: diag::ext_excess_initializers_for_sizeless_type;
SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
<< T << IList->getInit(Index)->getSourceRange();
} else {
int initKind = T->isArrayType() ? 0 :
T->isVectorType() ? 1 :
T->isScalarType() ? 2 :
T->isUnionType() ? 3 :
4;
unsigned DK = ExtraInitsIsError ? diag::err_excess_initializers
: diag::ext_excess_initializers;
SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
<< initKind << IList->getInit(Index)->getSourceRange();
}
}
if (!VerifyOnly) {
if (T->isScalarType() && IList->getNumInits() == 1 &&
!isa<InitListExpr>(IList->getInit(0)))
warnBracedScalarInit(SemaRef, Entity, IList->getSourceRange());
// Warn if this is a class type that won't be an aggregate in future
// versions of C++.
auto *CXXRD = T->getAsCXXRecordDecl();
if (CXXRD && CXXRD->hasUserDeclaredConstructor()) {
// Don't warn if there's an equivalent default constructor that would be
// used instead.
bool HasEquivCtor = false;
if (IList->getNumInits() == 0) {
auto *CD = SemaRef.LookupDefaultConstructor(CXXRD);
HasEquivCtor = CD && !CD->isDeleted();
}
if (!HasEquivCtor) {
SemaRef.Diag(IList->getBeginLoc(),
diag::warn_cxx20_compat_aggregate_init_with_ctors)
<< IList->getSourceRange() << T;
}
}
}
}
void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity,
InitListExpr *IList,
QualType &DeclType,
bool SubobjectIsDesignatorContext,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool TopLevelObject) {
if (DeclType->isAnyComplexType() && SubobjectIsDesignatorContext) {
// Explicitly braced initializer for complex type can be real+imaginary
// parts.
CheckComplexType(Entity, IList, DeclType, Index,
StructuredList, StructuredIndex);
} else if (DeclType->isScalarType()) {
CheckScalarType(Entity, IList, DeclType, Index,
StructuredList, StructuredIndex);
} else if (DeclType->isVectorType()) {
CheckVectorType(Entity, IList, DeclType, Index,
StructuredList, StructuredIndex);
} else if (DeclType->isRecordType()) {
assert(DeclType->isAggregateType() &&
"non-aggregate records should be handed in CheckSubElementType");
RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
auto Bases =
CXXRecordDecl::base_class_range(CXXRecordDecl::base_class_iterator(),
CXXRecordDecl::base_class_iterator());
if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
Bases = CXXRD->bases();
CheckStructUnionTypes(Entity, IList, DeclType, Bases, RD->field_begin(),
SubobjectIsDesignatorContext, Index, StructuredList,
StructuredIndex, TopLevelObject);
} else if (DeclType->isArrayType()) {
llvm::APSInt Zero(
SemaRef.Context.getTypeSize(SemaRef.Context.getSizeType()),
false);
CheckArrayType(Entity, IList, DeclType, Zero,
SubobjectIsDesignatorContext, Index,
StructuredList, StructuredIndex);
} else if (DeclType->isVoidType() || DeclType->isFunctionType()) {
// This type is invalid, issue a diagnostic.
++Index;
if (!VerifyOnly)
SemaRef.Diag(IList->getBeginLoc(), diag::err_illegal_initializer_type)
<< DeclType;
hadError = true;
} else if (DeclType->isReferenceType()) {
CheckReferenceType(Entity, IList, DeclType, Index,
StructuredList, StructuredIndex);
} else if (DeclType->isObjCObjectType()) {
if (!VerifyOnly)
SemaRef.Diag(IList->getBeginLoc(), diag::err_init_objc_class) << DeclType;
hadError = true;
} else if (DeclType->isOCLIntelSubgroupAVCType() ||
DeclType->isSizelessBuiltinType()) {
// Checks for scalar type are sufficient for these types too.
CheckScalarType(Entity, IList, DeclType, Index, StructuredList,
StructuredIndex);
} else {
if (!VerifyOnly)
SemaRef.Diag(IList->getBeginLoc(), diag::err_illegal_initializer_type)
<< DeclType;
hadError = true;
}
}
void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
InitListExpr *IList,
QualType ElemType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool DirectlyDesignated) {
Expr *expr = IList->getInit(Index);
if (ElemType->isReferenceType())
return CheckReferenceType(Entity, IList, ElemType, Index,
StructuredList, StructuredIndex);
if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) {
if (SubInitList->getNumInits() == 1 &&
IsStringInit(SubInitList->getInit(0), ElemType, SemaRef.Context) ==
SIF_None) {
// FIXME: It would be more faithful and no less correct to include an
// InitListExpr in the semantic form of the initializer list in this case.
expr = SubInitList->getInit(0);
}
// Nested aggregate initialization and C++ initialization are handled later.
} else if (isa<ImplicitValueInitExpr>(expr)) {
// This happens during template instantiation when we see an InitListExpr
// that we've already checked once.
assert(SemaRef.Context.hasSameType(expr->getType(), ElemType) &&
"found implicit initialization for the wrong type");
UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
++Index;
return;
}
if (SemaRef.getLangOpts().CPlusPlus || isa<InitListExpr>(expr)) {
// C++ [dcl.init.aggr]p2:
// Each member is copy-initialized from the corresponding
// initializer-clause.
// FIXME: Better EqualLoc?
InitializationKind Kind =
InitializationKind::CreateCopy(expr->getBeginLoc(), SourceLocation());
// Vector elements can be initialized from other vectors in which case
// we need initialization entity with a type of a vector (and not a vector
// element!) initializing multiple vector elements.
auto TmpEntity =
(ElemType->isExtVectorType() && !Entity.getType()->isExtVectorType())
? InitializedEntity::InitializeTemporary(ElemType)
: Entity;
InitializationSequence Seq(SemaRef, TmpEntity, Kind, expr,
/*TopLevelOfInitList*/ true);
// C++14 [dcl.init.aggr]p13:
// If the assignment-expression can initialize a member, the member is
// initialized. Otherwise [...] brace elision is assumed
//
// Brace elision is never performed if the element is not an
// assignment-expression.
if (Seq || isa<InitListExpr>(expr)) {
if (!VerifyOnly) {
ExprResult Result = Seq.Perform(SemaRef, TmpEntity, Kind, expr);
if (Result.isInvalid())
hadError = true;
UpdateStructuredListElement(StructuredList, StructuredIndex,
Result.getAs<Expr>());
} else if (!Seq) {
hadError = true;
} else if (StructuredList) {
UpdateStructuredListElement(StructuredList, StructuredIndex,
getDummyInit());
}
++Index;
return;
}
// Fall through for subaggregate initialization
} else if (ElemType->isScalarType() || ElemType->isAtomicType()) {
// FIXME: Need to handle atomic aggregate types with implicit init lists.
return CheckScalarType(Entity, IList, ElemType, Index,
StructuredList, StructuredIndex);
} else if (const ArrayType *arrayType =
SemaRef.Context.getAsArrayType(ElemType)) {
// arrayType can be incomplete if we're initializing a flexible
// array member. There's nothing we can do with the completed
// type here, though.
if (IsStringInit(expr, arrayType, SemaRef.Context) == SIF_None) {
// FIXME: Should we do this checking in verify-only mode?
if (!VerifyOnly)
CheckStringInit(expr, ElemType, arrayType, SemaRef);
if (StructuredList)
UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
++Index;
return;
}
// Fall through for subaggregate initialization.
} else {
assert((ElemType->isRecordType() || ElemType->isVectorType() ||
ElemType->isOpenCLSpecificType()) && "Unexpected type");
// C99 6.7.8p13:
//
// The initializer for a structure or union object that has
// automatic storage duration shall be either an initializer
// list as described below, or a single expression that has
// compatible structure or union type. In the latter case, the
// initial value of the object, including unnamed members, is
// that of the expression.
ExprResult ExprRes = expr;
if (SemaRef.CheckSingleAssignmentConstraints(
ElemType, ExprRes, !VerifyOnly) != Sema::Incompatible) {
if (ExprRes.isInvalid())
hadError = true;
else {
ExprRes = SemaRef.DefaultFunctionArrayLvalueConversion(ExprRes.get());
if (ExprRes.isInvalid())
hadError = true;
}
UpdateStructuredListElement(StructuredList, StructuredIndex,
ExprRes.getAs<Expr>());
++Index;
return;
}
ExprRes.get();
// Fall through for subaggregate initialization
}
// C++ [dcl.init.aggr]p12:
//
// [...] Otherwise, if the member is itself a non-empty
// subaggregate, brace elision is assumed and the initializer is
// considered for the initialization of the first member of
// the subaggregate.
// OpenCL vector initializer is handled elsewhere.
if ((!SemaRef.getLangOpts().OpenCL && ElemType->isVectorType()) ||
ElemType->isAggregateType()) {
CheckImplicitInitList(Entity, IList, ElemType, Index, StructuredList,
StructuredIndex);
++StructuredIndex;
// In C++20, brace elision is not permitted for a designated initializer.
if (DirectlyDesignated && SemaRef.getLangOpts().CPlusPlus && !hadError) {
if (InOverloadResolution)
hadError = true;
if (!VerifyOnly) {
SemaRef.Diag(expr->getBeginLoc(),
diag::ext_designated_init_brace_elision)
<< expr->getSourceRange()
<< FixItHint::CreateInsertion(expr->getBeginLoc(), "{")
<< FixItHint::CreateInsertion(
SemaRef.getLocForEndOfToken(expr->getEndLoc()), "}");
}
}
} else {
if (!VerifyOnly) {
// We cannot initialize this element, so let PerformCopyInitialization
// produce the appropriate diagnostic. We already checked that this
// initialization will fail.
ExprResult Copy =
SemaRef.PerformCopyInitialization(Entity, SourceLocation(), expr,
/*TopLevelOfInitList=*/true);
(void)Copy;
assert(Copy.isInvalid() &&
"expected non-aggregate initialization to fail");
}
hadError = true;
++Index;
++StructuredIndex;
}
}
void InitListChecker::CheckComplexType(const InitializedEntity &Entity,
InitListExpr *IList, QualType DeclType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex) {
assert(Index == 0 && "Index in explicit init list must be zero");
// As an extension, clang supports complex initializers, which initialize
// a complex number component-wise. When an explicit initializer list for
// a complex number contains two two initializers, this extension kicks in:
// it exepcts the initializer list to contain two elements convertible to
// the element type of the complex type. The first element initializes
// the real part, and the second element intitializes the imaginary part.
if (IList->getNumInits() != 2)
return CheckScalarType(Entity, IList, DeclType, Index, StructuredList,
StructuredIndex);
// This is an extension in C. (The builtin _Complex type does not exist
// in the C++ standard.)
if (!SemaRef.getLangOpts().CPlusPlus && !VerifyOnly)
SemaRef.Diag(IList->getBeginLoc(), diag::ext_complex_component_init)
<< IList->getSourceRange();
// Initialize the complex number.
QualType elementType = DeclType->castAs<ComplexType>()->getElementType();
InitializedEntity ElementEntity =
InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
for (unsigned i = 0; i < 2; ++i) {
ElementEntity.setElementIndex(Index);
CheckSubElementType(ElementEntity, IList, elementType, Index,
StructuredList, StructuredIndex);
}
}
void InitListChecker::CheckScalarType(const InitializedEntity &Entity,
InitListExpr *IList, QualType DeclType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex) {
if (Index >= IList->getNumInits()) {
if (!VerifyOnly) {
if (DeclType->isSizelessBuiltinType())
SemaRef.Diag(IList->getBeginLoc(),
SemaRef.getLangOpts().CPlusPlus11
? diag::warn_cxx98_compat_empty_sizeless_initializer
: diag::err_empty_sizeless_initializer)
<< DeclType << IList->getSourceRange();
else
SemaRef.Diag(IList->getBeginLoc(),
SemaRef.getLangOpts().CPlusPlus11
? diag::warn_cxx98_compat_empty_scalar_initializer
: diag::err_empty_scalar_initializer)
<< IList->getSourceRange();
}
hadError = !SemaRef.getLangOpts().CPlusPlus11;
++Index;
++StructuredIndex;
return;
}
Expr *expr = IList->getInit(Index);
if (InitListExpr *SubIList = dyn_cast<InitListExpr>(expr)) {
// FIXME: This is invalid, and accepting it causes overload resolution
// to pick the wrong overload in some corner cases.
if (!VerifyOnly)
SemaRef.Diag(SubIList->getBeginLoc(), diag::ext_many_braces_around_init)
<< DeclType->isSizelessBuiltinType() << SubIList->getSourceRange();
CheckScalarType(Entity, SubIList, DeclType, Index, StructuredList,
StructuredIndex);
return;
} else if (isa<DesignatedInitExpr>(expr)) {
if (!VerifyOnly)
SemaRef.Diag(expr->getBeginLoc(),
diag::err_designator_for_scalar_or_sizeless_init)
<< DeclType->isSizelessBuiltinType() << DeclType
<< expr->getSourceRange();
hadError = true;
++Index;
++StructuredIndex;
return;
}
ExprResult Result;
if (VerifyOnly) {
if (SemaRef.CanPerformCopyInitialization(Entity, expr))
Result = getDummyInit();
else
Result = ExprError();
} else {
Result =
SemaRef.PerformCopyInitialization(Entity, expr->getBeginLoc(), expr,
/*TopLevelOfInitList=*/true);
}
Expr *ResultExpr = nullptr;
if (Result.isInvalid())
hadError = true; // types weren't compatible.
else {
ResultExpr = Result.getAs<Expr>();
if (ResultExpr != expr && !VerifyOnly) {
// The type was promoted, update initializer list.
// FIXME: Why are we updating the syntactic init list?
IList->setInit(Index, ResultExpr);
}
}
UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
++Index;
}
void InitListChecker::CheckReferenceType(const InitializedEntity &Entity,
InitListExpr *IList, QualType DeclType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex) {
if (Index >= IList->getNumInits()) {
// FIXME: It would be wonderful if we could point at the actual member. In
// general, it would be useful to pass location information down the stack,
// so that we know the location (or decl) of the "current object" being
// initialized.
if (!VerifyOnly)
SemaRef.Diag(IList->getBeginLoc(),
diag::err_init_reference_member_uninitialized)
<< DeclType << IList->getSourceRange();
hadError = true;
++Index;
++StructuredIndex;
return;
}
Expr *expr = IList->getInit(Index);
if (isa<InitListExpr>(expr) && !SemaRef.getLangOpts().CPlusPlus11) {
if (!VerifyOnly)
SemaRef.Diag(IList->getBeginLoc(), diag::err_init_non_aggr_init_list)
<< DeclType << IList->getSourceRange();
hadError = true;
++Index;
++StructuredIndex;
return;
}
ExprResult Result;
if (VerifyOnly) {
if (SemaRef.CanPerformCopyInitialization(Entity,expr))
Result = getDummyInit();
else
Result = ExprError();
} else {
Result =
SemaRef.PerformCopyInitialization(Entity, expr->getBeginLoc(), expr,
/*TopLevelOfInitList=*/true);
}
if (Result.isInvalid())
hadError = true;
expr = Result.getAs<Expr>();
// FIXME: Why are we updating the syntactic init list?
if (!VerifyOnly && expr)
IList->setInit(Index, expr);
UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
++Index;
}
void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
InitListExpr *IList, QualType DeclType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex) {
const VectorType *VT = DeclType->castAs<VectorType>();
unsigned maxElements = VT->getNumElements();
unsigned numEltsInit = 0;
QualType elementType = VT->getElementType();
if (Index >= IList->getNumInits()) {
// Make sure the element type can be value-initialized.
CheckEmptyInitializable(
InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity),
IList->getEndLoc());
return;
}
if (!SemaRef.getLangOpts().OpenCL) {
// If the initializing element is a vector, try to copy-initialize
// instead of breaking it apart (which is doomed to failure anyway).
Expr *Init = IList->getInit(Index);
if (!isa<InitListExpr>(Init) && Init->getType()->isVectorType()) {
ExprResult Result;
if (VerifyOnly) {
if (SemaRef.CanPerformCopyInitialization(Entity, Init))
Result = getDummyInit();
else
Result = ExprError();
} else {
Result =
SemaRef.PerformCopyInitialization(Entity, Init->getBeginLoc(), Init,
/*TopLevelOfInitList=*/true);
}
Expr *ResultExpr = nullptr;
if (Result.isInvalid())
hadError = true; // types weren't compatible.
else {
ResultExpr = Result.getAs<Expr>();
if (ResultExpr != Init && !VerifyOnly) {
// The type was promoted, update initializer list.
// FIXME: Why are we updating the syntactic init list?
IList->setInit(Index, ResultExpr);
}
}
UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
++Index;
return;
}
InitializedEntity ElementEntity =
InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
for (unsigned i = 0; i < maxElements; ++i, ++numEltsInit) {
// Don't attempt to go past the end of the init list
if (Index >= IList->getNumInits()) {
CheckEmptyInitializable(ElementEntity, IList->getEndLoc());
break;
}
ElementEntity.setElementIndex(Index);
CheckSubElementType(ElementEntity, IList, elementType, Index,
StructuredList, StructuredIndex);
}
if (VerifyOnly)
return;
bool isBigEndian = SemaRef.Context.getTargetInfo().isBigEndian();
const VectorType *T = Entity.getType()->castAs<VectorType>();
if (isBigEndian && (T->getVectorKind() == VectorType::NeonVector ||
T->getVectorKind() == VectorType::NeonPolyVector)) {
// The ability to use vector initializer lists is a GNU vector extension
// and is unrelated to the NEON intrinsics in arm_neon.h. On little
// endian machines it works fine, however on big endian machines it
// exhibits surprising behaviour:
//
// uint32x2_t x = {42, 64};
// return vget_lane_u32(x, 0); // Will return 64.
//
// Because of this, explicitly call out that it is non-portable.
//
SemaRef.Diag(IList->getBeginLoc(),
diag::warn_neon_vector_initializer_non_portable);
const char *typeCode;
unsigned typeSize = SemaRef.Context.getTypeSize(elementType);
if (elementType->isFloatingType())
typeCode = "f";
else if (elementType->isSignedIntegerType())
typeCode = "s";
else if (elementType->isUnsignedIntegerType())
typeCode = "u";
else
llvm_unreachable("Invalid element type!");
SemaRef.Diag(IList->getBeginLoc(),
SemaRef.Context.getTypeSize(VT) > 64
? diag::note_neon_vector_initializer_non_portable_q
: diag::note_neon_vector_initializer_non_portable)
<< typeCode << typeSize;
}
return;
}
InitializedEntity ElementEntity =
InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
// OpenCL initializers allows vectors to be constructed from vectors.
for (unsigned i = 0; i < maxElements; ++i) {
// Don't attempt to go past the end of the init list
if (Index >= IList->getNumInits())
break;
ElementEntity.setElementIndex(Index);
QualType IType = IList->getInit(Index)->getType();
if (!IType->isVectorType()) {
CheckSubElementType(ElementEntity, IList, elementType, Index,
StructuredList, StructuredIndex);
++numEltsInit;
} else {
QualType VecType;
const VectorType *IVT = IType->castAs<VectorType>();
unsigned numIElts = IVT->getNumElements();
if (IType->isExtVectorType())
VecType = SemaRef.Context.getExtVectorType(elementType, numIElts);
else
VecType = SemaRef.Context.getVectorType(elementType, numIElts,
IVT->getVectorKind());
CheckSubElementType(ElementEntity, IList, VecType, Index,
StructuredList, StructuredIndex);
numEltsInit += numIElts;
}
}
// OpenCL requires all elements to be initialized.
if (numEltsInit != maxElements) {
if (!VerifyOnly)
SemaRef.Diag(IList->getBeginLoc(),
diag::err_vector_incorrect_num_initializers)
<< (numEltsInit < maxElements) << maxElements << numEltsInit;
hadError = true;
}
}
/// Check if the type of a class element has an accessible destructor, and marks
/// it referenced. Returns true if we shouldn't form a reference to the
/// destructor.
///
/// Aggregate initialization requires a class element's destructor be
/// accessible per 11.6.1 [dcl.init.aggr]:
///
/// The destructor for each element of class type is potentially invoked
/// (15.4 [class.dtor]) from the context where the aggregate initialization
/// occurs.
static bool checkDestructorReference(QualType ElementType, SourceLocation Loc,
Sema &SemaRef) {
auto *CXXRD = ElementType->getAsCXXRecordDecl();
if (!CXXRD)
return false;
CXXDestructorDecl *Destructor = SemaRef.LookupDestructor(CXXRD);
SemaRef.CheckDestructorAccess(Loc, Destructor,
SemaRef.PDiag(diag::err_access_dtor_temp)
<< ElementType);
SemaRef.MarkFunctionReferenced(Loc, Destructor);
return SemaRef.DiagnoseUseOfDecl(Destructor, Loc);
}
void InitListChecker::CheckArrayType(const InitializedEntity &Entity,
InitListExpr *IList, QualType &DeclType,
llvm::APSInt elementIndex,
bool SubobjectIsDesignatorContext,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex) {
const ArrayType *arrayType = SemaRef.Context.getAsArrayType(DeclType);
if (!VerifyOnly) {
if (checkDestructorReference(arrayType->getElementType(),
IList->getEndLoc(), SemaRef)) {
hadError = true;
return;
}
}
// Check for the special-case of initializing an array with a string.
if (Index < IList->getNumInits()) {
if (IsStringInit(IList->getInit(Index), arrayType, SemaRef.Context) ==
SIF_None) {
// We place the string literal directly into the resulting
// initializer list. This is the only place where the structure
// of the structured initializer list doesn't match exactly,
// because doing so would involve allocating one character
// constant for each string.
// FIXME: Should we do these checks in verify-only mode too?
if (!VerifyOnly)
CheckStringInit(IList->getInit(Index), DeclType, arrayType, SemaRef);
if (StructuredList) {
UpdateStructuredListElement(StructuredList, StructuredIndex,
IList->getInit(Index));
StructuredList->resizeInits(SemaRef.Context, StructuredIndex);
}
++Index;
return;
}
}
if (const VariableArrayType *VAT = dyn_cast<VariableArrayType>(arrayType)) {
// Check for VLAs; in standard C it would be possible to check this
// earlier, but I don't know where clang accepts VLAs (gcc accepts
// them in all sorts of strange places).
if (!VerifyOnly)
SemaRef.Diag(VAT->getSizeExpr()->getBeginLoc(),
diag::err_variable_object_no_init)
<< VAT->getSizeExpr()->getSourceRange();
hadError = true;
++Index;
++StructuredIndex;
return;
}
// We might know the maximum number of elements in advance.
llvm::APSInt maxElements(elementIndex.getBitWidth(),
elementIndex.isUnsigned());
bool maxElementsKnown = false;
if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(arrayType)) {
maxElements = CAT->getSize();
elementIndex = elementIndex.extOrTrunc(maxElements.getBitWidth());
elementIndex.setIsUnsigned(maxElements.isUnsigned());
maxElementsKnown = true;
}
QualType elementType = arrayType->getElementType();
while (Index < IList->getNumInits()) {
Expr *Init = IList->getInit(Index);
if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
// If we're not the subobject that matches up with the '{' for
// the designator, we shouldn't be handling the
// designator. Return immediately.
if (!SubobjectIsDesignatorContext)
return;
// Handle this designated initializer. elementIndex will be
// updated to be the next array element we'll initialize.
if (CheckDesignatedInitializer(Entity, IList, DIE, 0,
DeclType, nullptr, &elementIndex, Index,
StructuredList, StructuredIndex, true,
false)) {
hadError = true;
continue;
}
if (elementIndex.getBitWidth() > maxElements.getBitWidth())
maxElements = maxElements.extend(elementIndex.getBitWidth());
else if (elementIndex.getBitWidth() < maxElements.getBitWidth())
elementIndex = elementIndex.extend(maxElements.getBitWidth());
elementIndex.setIsUnsigned(maxElements.isUnsigned());
// If the array is of incomplete type, keep track of the number of
// elements in the initializer.
if (!maxElementsKnown && elementIndex > maxElements)
maxElements = elementIndex;
continue;
}
// If we know the maximum number of elements, and we've already
// hit it, stop consuming elements in the initializer list.
if (maxElementsKnown && elementIndex == maxElements)
break;
InitializedEntity ElementEntity =
InitializedEntity::InitializeElement(SemaRef.Context, StructuredIndex,
Entity);
// Check this element.
CheckSubElementType(ElementEntity, IList, elementType, Index,
StructuredList, StructuredIndex);
++elementIndex;
// If the array is of incomplete type, keep track of the number of
// elements in the initializer.
if (!maxElementsKnown && elementIndex > maxElements)
maxElements = elementIndex;
}
if (!hadError && DeclType->isIncompleteArrayType() && !VerifyOnly) {
// If this is an incomplete array type, the actual type needs to
// be calculated here.
llvm::APSInt Zero(maxElements.getBitWidth(), maxElements.isUnsigned());
if (maxElements == Zero && !Entity.isVariableLengthArrayNew()) {
// Sizing an array implicitly to zero is not allowed by ISO C,
// but is supported by GNU.
SemaRef.Diag(IList->getBeginLoc(), diag::ext_typecheck_zero_array_size);
}
DeclType = SemaRef.Context.getConstantArrayType(
elementType, maxElements, nullptr, ArrayType::Normal, 0);
}
if (!hadError) {
// If there are any members of the array that get value-initialized, check
// that is possible. That happens if we know the bound and don't have
// enough elements, or if we're performing an array new with an unknown
// bound.
if ((maxElementsKnown && elementIndex < maxElements) ||
Entity.isVariableLengthArrayNew())
CheckEmptyInitializable(
InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity),
IList->getEndLoc());
}
}
bool InitListChecker::CheckFlexibleArrayInit(const InitializedEntity &Entity,
Expr *InitExpr,
FieldDecl *Field,
bool TopLevelObject) {
// Handle GNU flexible array initializers.
unsigned FlexArrayDiag;
if (isa<InitListExpr>(InitExpr) &&
cast<InitListExpr>(InitExpr)->getNumInits() == 0) {
// Empty flexible array init always allowed as an extension
FlexArrayDiag = diag::ext_flexible_array_init;
} else if (SemaRef.getLangOpts().CPlusPlus) {
// Disallow flexible array init in C++; it is not required for gcc
// compatibility, and it needs work to IRGen correctly in general.
FlexArrayDiag = diag::err_flexible_array_init;
} else if (!TopLevelObject) {
// Disallow flexible array init on non-top-level object
FlexArrayDiag = diag::err_flexible_array_init;
} else if (Entity.getKind() != InitializedEntity::EK_Variable) {
// Disallow flexible array init on anything which is not a variable.
FlexArrayDiag = diag::err_flexible_array_init;
} else if (cast<VarDecl>(Entity.getDecl())->hasLocalStorage()) {
// Disallow flexible array init on local variables.
FlexArrayDiag = diag::err_flexible_array_init;
} else {
// Allow other cases.
FlexArrayDiag = diag::ext_flexible_array_init;
}
if (!VerifyOnly) {
SemaRef.Diag(InitExpr->getBeginLoc(), FlexArrayDiag)
<< InitExpr->getBeginLoc();
SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
<< Field;
}
return FlexArrayDiag != diag::ext_flexible_array_init;
}
void InitListChecker::CheckStructUnionTypes(
const InitializedEntity &Entity, InitListExpr *IList, QualType DeclType,
CXXRecordDecl::base_class_range Bases, RecordDecl::field_iterator Field,
bool SubobjectIsDesignatorContext, unsigned &Index,
InitListExpr *StructuredList, unsigned &StructuredIndex,
bool TopLevelObject) {
RecordDecl *structDecl = DeclType->castAs<RecordType>()->getDecl();
// If the record is invalid, some of it's members are invalid. To avoid
// confusion, we forgo checking the intializer for the entire record.
if (structDecl->isInvalidDecl()) {
// Assume it was supposed to consume a single initializer.
++Index;
hadError = true;
return;
}
if (DeclType->isUnionType() && IList->getNumInits() == 0) {
RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
if (!VerifyOnly)
for (FieldDecl *FD : RD->fields()) {
QualType ET = SemaRef.Context.getBaseElementType(FD->getType());
if (checkDestructorReference(ET, IList->getEndLoc(), SemaRef)) {
hadError = true;
return;
}
}
// If there's a default initializer, use it.
if (isa<CXXRecordDecl>(RD) &&
cast<CXXRecordDecl>(RD)->hasInClassInitializer()) {
if (!StructuredList)
return;
for (RecordDecl::field_iterator FieldEnd = RD->field_end();
Field != FieldEnd; ++Field) {
if (Field->hasInClassInitializer()) {
StructuredList->setInitializedFieldInUnion(*Field);
// FIXME: Actually build a CXXDefaultInitExpr?
return;
}
}
}
// Value-initialize the first member of the union that isn't an unnamed
// bitfield.
for (RecordDecl::field_iterator FieldEnd = RD->field_end();
Field != FieldEnd; ++Field) {
if (!Field->isUnnamedBitfield()) {
CheckEmptyInitializable(
InitializedEntity::InitializeMember(*Field, &Entity),
IList->getEndLoc());
if (StructuredList)
StructuredList->setInitializedFieldInUnion(*Field);
break;
}
}
return;
}
bool InitializedSomething = false;
// If we have any base classes, they are initialized prior to the fields.
for (auto &Base : Bases) {
Expr *Init = Index < IList->getNumInits() ? IList->getInit(Index) : nullptr;
// Designated inits always initialize fields, so if we see one, all
// remaining base classes have no explicit initializer.
if (Init && isa<DesignatedInitExpr>(Init))
Init = nullptr;
SourceLocation InitLoc = Init ? Init->getBeginLoc() : IList->getEndLoc();
InitializedEntity BaseEntity = InitializedEntity::InitializeBase(
SemaRef.Context, &Base, false, &Entity);
if (Init) {
CheckSubElementType(BaseEntity, IList, Base.getType(), Index,
StructuredList, StructuredIndex);
InitializedSomething = true;
} else {
CheckEmptyInitializable(BaseEntity, InitLoc);
}
if (!VerifyOnly)
if (checkDestructorReference(Base.getType(), InitLoc, SemaRef)) {
hadError = true;
return;
}
}
// If structDecl is a forward declaration, this loop won't do
// anything except look at designated initializers; That's okay,
// because an error should get printed out elsewhere. It might be
// worthwhile to skip over the rest of the initializer, though.
RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
RecordDecl::field_iterator FieldEnd = RD->field_end();
bool CheckForMissingFields =
!IList->isIdiomaticZeroInitializer(SemaRef.getLangOpts());
bool HasDesignatedInit = false;
while (Index < IList->getNumInits()) {
Expr *Init = IList->getInit(Index);
SourceLocation InitLoc = Init->getBeginLoc();
if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
// If we're not the subobject that matches up with the '{' for
// the designator, we shouldn't be handling the
// designator. Return immediately.
if (!SubobjectIsDesignatorContext)
return;
HasDesignatedInit = true;
// Handle this designated initializer. Field will be updated to
// the next field that we'll be initializing.
if (CheckDesignatedInitializer(Entity, IList, DIE, 0,
DeclType, &Field, nullptr, Index,
StructuredList, StructuredIndex,
true, TopLevelObject))
hadError = true;
else if (!VerifyOnly) {
// Find the field named by the designated initializer.
RecordDecl::field_iterator F = RD->field_begin();
while (std::next(F) != Field)
++F;
QualType ET = SemaRef.Context.getBaseElementType(F->getType());
if (checkDestructorReference(ET, InitLoc, SemaRef)) {
hadError = true;
return;
}
}
InitializedSomething = true;
// Disable check for missing fields when designators are used.
// This matches gcc behaviour.
CheckForMissingFields = false;
continue;
}
if (Field == FieldEnd) {
// We've run out of fields. We're done.
break;
}
// We've already initialized a member of a union. We're done.
if (InitializedSomething && DeclType->isUnionType())
break;
// If we've hit the flexible array member at the end, we're done.
if (Field->getType()->isIncompleteArrayType())
break;
if (Field->isUnnamedBitfield()) {
// Don't initialize unnamed bitfields, e.g. "int : 20;"
++Field;
continue;
}
// Make sure we can use this declaration.
bool InvalidUse;
if (VerifyOnly)
InvalidUse = !SemaRef.CanUseDecl(*Field, TreatUnavailableAsInvalid);
else
InvalidUse = SemaRef.DiagnoseUseOfDecl(
*Field, IList->getInit(Index)->getBeginLoc());
if (InvalidUse) {
++Index;
++Field;
hadError = true;
continue;
}
if (!VerifyOnly) {
QualType ET = SemaRef.Context.getBaseElementType(Field->getType());
if (checkDestructorReference(ET, InitLoc, SemaRef)) {
hadError = true;
return;
}
}
InitializedEntity MemberEntity =
InitializedEntity::InitializeMember(*Field, &Entity);
CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
StructuredList, StructuredIndex);
InitializedSomething = true;
if (DeclType->isUnionType() && StructuredList) {
// Initialize the first field within the union.
StructuredList->setInitializedFieldInUnion(*Field);
}
++Field;
}
// Emit warnings for missing struct field initializers.
if (!VerifyOnly && InitializedSomething && CheckForMissingFields &&
Field != FieldEnd && !Field->getType()->isIncompleteArrayType() &&
!DeclType->isUnionType()) {
// It is possible we have one or more unnamed bitfields remaining.
// Find first (if any) named field and emit warning.
for (RecordDecl::field_iterator it = Field, end = RD->field_end();
it != end; ++it) {
if (!it->isUnnamedBitfield() && !it->hasInClassInitializer()) {
SemaRef.Diag(IList->getSourceRange().getEnd(),
diag::warn_missing_field_initializers) << *it;
break;
}
}
}
// Check that any remaining fields can be value-initialized if we're not
// building a structured list. (If we are, we'll check this later.)
if (!StructuredList && Field != FieldEnd && !DeclType->isUnionType() &&
!Field->getType()->isIncompleteArrayType()) {
for (; Field != FieldEnd && !hadError; ++Field) {
if (!Field->isUnnamedBitfield() && !Field->hasInClassInitializer())
CheckEmptyInitializable(
InitializedEntity::InitializeMember(*Field, &Entity),
IList->getEndLoc());
}
}
// Check that the types of the remaining fields have accessible destructors.
if (!VerifyOnly) {
// If the initializer expression has a designated initializer, check the
// elements for which a designated initializer is not provided too.
RecordDecl::field_iterator I = HasDesignatedInit ? RD->field_begin()
: Field;
for (RecordDecl::field_iterator E = RD->field_end(); I != E; ++I) {
QualType ET = SemaRef.Context.getBaseElementType(I->getType());
if (checkDestructorReference(ET, IList->getEndLoc(), SemaRef)) {
hadError = true;
return;
}
}
}
if (Field == FieldEnd || !Field->getType()->isIncompleteArrayType() ||
Index >= IList->getNumInits())
return;
if (CheckFlexibleArrayInit(Entity, IList->getInit(Index), *Field,
TopLevelObject)) {
hadError = true;
++Index;
return;
}
InitializedEntity MemberEntity =
InitializedEntity::InitializeMember(*Field, &Entity);
if (isa<InitListExpr>(IList->getInit(Index)))
CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
StructuredList, StructuredIndex);
else
CheckImplicitInitList(MemberEntity, IList, Field->getType(), Index,
StructuredList, StructuredIndex);
}
/// Expand a field designator that refers to a member of an
/// anonymous struct or union into a series of field designators that
/// refers to the field within the appropriate subobject.
///
static void ExpandAnonymousFieldDesignator(Sema &SemaRef,
DesignatedInitExpr *DIE,
unsigned DesigIdx,
IndirectFieldDecl *IndirectField) {
typedef DesignatedInitExpr::Designator Designator;
// Build the replacement designators.
SmallVector<Designator, 4> Replacements;
for (IndirectFieldDecl::chain_iterator PI = IndirectField->chain_begin(),
PE = IndirectField->chain_end(); PI != PE; ++PI) {
if (PI + 1 == PE)
Replacements.push_back(Designator((IdentifierInfo *)nullptr,
DIE->getDesignator(DesigIdx)->getDotLoc(),
DIE->getDesignator(DesigIdx)->getFieldLoc()));
else
Replacements.push_back(Designator((IdentifierInfo *)nullptr,
SourceLocation(), SourceLocation()));
assert(isa<FieldDecl>(*PI));
Replacements.back().setField(cast<FieldDecl>(*PI));
}
// Expand the current designator into the set of replacement
// designators, so we have a full subobject path down to where the
// member of the anonymous struct/union is actually stored.
DIE->ExpandDesignator(SemaRef.Context, DesigIdx, &Replacements[0],
&Replacements[0] + Replacements.size());
}
static DesignatedInitExpr *CloneDesignatedInitExpr(Sema &SemaRef,
DesignatedInitExpr *DIE) {
unsigned NumIndexExprs = DIE->getNumSubExprs() - 1;
SmallVector<Expr*, 4> IndexExprs(NumIndexExprs);
for (unsigned I = 0; I < NumIndexExprs; ++I)
IndexExprs[I] = DIE->getSubExpr(I + 1);
return DesignatedInitExpr::Create(SemaRef.Context, DIE->designators(),
IndexExprs,
DIE->getEqualOrColonLoc(),
DIE->usesGNUSyntax(), DIE->getInit());
}
namespace {
// Callback to only accept typo corrections that are for field members of
// the given struct or union.
class FieldInitializerValidatorCCC final : public CorrectionCandidateCallback {
public:
explicit FieldInitializerValidatorCCC(RecordDecl *RD)
: Record(RD) {}
bool ValidateCandidate(const TypoCorrection &candidate) override {
FieldDecl *FD = candidate.getCorrectionDeclAs<FieldDecl>();
return FD && FD->getDeclContext()->getRedeclContext()->Equals(Record);
}
std::unique_ptr<CorrectionCandidateCallback> clone() override {
return std::make_unique<FieldInitializerValidatorCCC>(*this);
}
private:
RecordDecl *Record;
};
} // end anonymous namespace
/// Check the well-formedness of a C99 designated initializer.
///
/// Determines whether the designated initializer @p DIE, which
/// resides at the given @p Index within the initializer list @p
/// IList, is well-formed for a current object of type @p DeclType
/// (C99 6.7.8). The actual subobject that this designator refers to
/// within the current subobject is returned in either
/// @p NextField or @p NextElementIndex (whichever is appropriate).
///
/// @param IList The initializer list in which this designated
/// initializer occurs.
///
/// @param DIE The designated initializer expression.
///
/// @param DesigIdx The index of the current designator.
///
/// @param CurrentObjectType The type of the "current object" (C99 6.7.8p17),
/// into which the designation in @p DIE should refer.
///
/// @param NextField If non-NULL and the first designator in @p DIE is
/// a field, this will be set to the field declaration corresponding
/// to the field named by the designator. On input, this is expected to be
/// the next field that would be initialized in the absence of designation,
/// if the complete object being initialized is a struct.
///
/// @param NextElementIndex If non-NULL and the first designator in @p
/// DIE is an array designator or GNU array-range designator, this
/// will be set to the last index initialized by this designator.
///
/// @param Index Index into @p IList where the designated initializer
/// @p DIE occurs.
///
/// @param StructuredList The initializer list expression that
/// describes all of the subobject initializers in the order they'll
/// actually be initialized.
///
/// @returns true if there was an error, false otherwise.
bool
InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
InitListExpr *IList,
DesignatedInitExpr *DIE,
unsigned DesigIdx,
QualType &CurrentObjectType,
RecordDecl::field_iterator *NextField,
llvm::APSInt *NextElementIndex,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool FinishSubobjectInit,
bool TopLevelObject) {
if (DesigIdx == DIE->size()) {
// C++20 designated initialization can result in direct-list-initialization
// of the designated subobject. This is the only way that we can end up
// performing direct initialization as part of aggregate initialization, so
// it needs special handling.
if (DIE->isDirectInit()) {
Expr *Init = DIE->getInit();
assert(isa<InitListExpr>(Init) &&
"designator result in direct non-list initialization?");
InitializationKind Kind = InitializationKind::CreateDirectList(
DIE->getBeginLoc(), Init->getBeginLoc(), Init->getEndLoc());
InitializationSequence Seq(SemaRef, Entity, Kind, Init,
/*TopLevelOfInitList*/ true);
if (StructuredList) {
ExprResult Result = VerifyOnly
? getDummyInit()
: Seq.Perform(SemaRef, Entity, Kind, Init);
UpdateStructuredListElement(StructuredList, StructuredIndex,
Result.get());
}
++Index;
return !Seq;
}
// Check the actual initialization for the designated object type.
bool prevHadError = hadError;
// Temporarily remove the designator expression from the
// initializer list that the child calls see, so that we don't try
// to re-process the designator.
unsigned OldIndex = Index;
IList->setInit(OldIndex, DIE->getInit());
CheckSubElementType(Entity, IList, CurrentObjectType, Index, StructuredList,
StructuredIndex, /*DirectlyDesignated=*/true);
// Restore the designated initializer expression in the syntactic
// form of the initializer list.
if (IList->getInit(OldIndex) != DIE->getInit())
DIE->setInit(IList->getInit(OldIndex));
IList->setInit(OldIndex, DIE);
return hadError && !prevHadError;
}
DesignatedInitExpr::Designator *D = DIE->getDesignator(DesigIdx);
bool IsFirstDesignator = (DesigIdx == 0);
if (IsFirstDesignator ? FullyStructuredList : StructuredList) {
// Determine the structural initializer list that corresponds to the
// current subobject.
if (IsFirstDesignator)
StructuredList = FullyStructuredList;
else {
Expr *ExistingInit = StructuredIndex < StructuredList->getNumInits() ?
StructuredList->getInit(StructuredIndex) : nullptr;
if (!ExistingInit && StructuredList->hasArrayFiller())
ExistingInit = StructuredList->getArrayFiller();
if (!ExistingInit)
StructuredList = getStructuredSubobjectInit(
IList, Index, CurrentObjectType, StructuredList, StructuredIndex,
SourceRange(D->getBeginLoc(), DIE->getEndLoc()));
else if (InitListExpr *Result = dyn_cast<InitListExpr>(ExistingInit))
StructuredList = <