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llvm-project/clang/lib/Sema/SemaInit.cpp

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//===--- SemaInit.cpp - Semantic Analysis for Initializers ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements semantic analysis for initializers.
//
//===----------------------------------------------------------------------===//
#include "clang/Sema/Initialization.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "clang/AST/TypeLoc.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Sema/Designator.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/SemaInternal.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include <map>
using namespace clang;
//===----------------------------------------------------------------------===//
// Sema Initialization Checking
//===----------------------------------------------------------------------===//
/// \brief 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_Other
};
/// \brief 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::Ascii:
case StringLiteral::UTF8:
// char array can be initialized with a narrow string.
// Only allow char x[] = "foo"; not char x[] = L"foo";
if (ElemTy->isCharType())
return SIF_None;
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())
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())
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())
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);
}
/// 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);
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))
E = UO->getSubExpr();
else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E))
E = GSE->getResultExpr();
else
llvm_unreachable("unexpected expr in string literal init");
}
}
static void CheckStringInit(Expr *Str, QualType &DeclT, const ArrayType *AT,
Sema &S) {
// Get the length of the string as parsed.
uint64_t StrLength =
cast<ConstantArrayType>(Str->getType())->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,
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->getLocStart(),
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->getLocStart(),
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.
//===----------------------------------------------------------------------===//
/// @brief 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.
namespace {
class InitListChecker {
Sema &SemaRef;
bool hadError;
bool VerifyOnly; // no diagnostics, no structure building
llvm::DenseMap<InitListExpr *, InitListExpr *> SyntacticToSemantic;
InitListExpr *FullyStructuredList;
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);
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,
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);
void UpdateStructuredListElement(InitListExpr *StructuredList,
unsigned &StructuredIndex,
Expr *expr);
int numArrayElements(QualType DeclType);
int numStructUnionElements(QualType DeclType);
static ExprResult PerformEmptyInit(Sema &SemaRef,
SourceLocation Loc,
const InitializedEntity &Entity,
bool VerifyOnly);
void FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
const InitializedEntity &ParentEntity,
InitListExpr *ILE, bool &RequiresSecondPass);
void FillInEmptyInitializations(const InitializedEntity &Entity,
InitListExpr *ILE, bool &RequiresSecondPass);
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 HadError() { return hadError; }
// @brief Retrieves the fully-structured initializer list used for
// semantic analysis and code generation.
InitListExpr *getFullyStructuredList() const { return FullyStructuredList; }
};
} // end anonymous namespace
ExprResult InitListChecker::PerformEmptyInit(Sema &SemaRef,
SourceLocation Loc,
const InitializedEntity &Entity,
bool VerifyOnly) {
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);
// 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);
SemaRef.Diag(Entity.getDecl()->getLocation(),
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)
SemaRef.Diag(Loc, diag::note_in_omitted_aggregate_initializer)
<< /*array element*/0 << Entity.getElementIndex();
}
return ExprError();
}
return VerifyOnly ? ExprResult(static_cast<Expr *>(nullptr))
: InitSeq.Perform(SemaRef, Entity, Kind, SubInit);
}
void InitListChecker::CheckEmptyInitializable(const InitializedEntity &Entity,
SourceLocation Loc) {
assert(VerifyOnly &&
"CheckEmptyInitializable is only inteded for verification mode.");
if (PerformEmptyInit(SemaRef, Loc, Entity, /*VerifyOnly*/true).isInvalid())
hadError = true;
}
void InitListChecker::FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
const InitializedEntity &ParentEntity,
InitListExpr *ILE,
bool &RequiresSecondPass) {
SourceLocation Loc = ILE->getLocEnd();
unsigned NumInits = ILE->getNumInits();
InitializedEntity MemberEntity
= InitializedEntity::InitializeMember(Field, &ParentEntity);
if (Init >= NumInits || !ILE->getInit(Init)) {
// 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()) {
Expr *DIE = CXXDefaultInitExpr::Create(SemaRef.Context, Loc, Field);
if (Init < NumInits)
ILE->setInit(Init, DIE);
else {
ILE->updateInit(SemaRef.Context, Init, DIE);
RequiresSecondPass = true;
}
return;
}
if (Field->getType()->isReferenceType()) {
// 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(SemaRef, Loc, MemberEntity,
/*VerifyOnly*/false);
if (MemberInit.isInvalid()) {
hadError = true;
return;
}
if (hadError) {
// 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);
}
/// Recursively replaces NULL values within the given initializer list
/// with expressions that perform value-initialization of the
/// appropriate type.
void
InitListChecker::FillInEmptyInitializations(const InitializedEntity &Entity,
InitListExpr *ILE,
bool &RequiresSecondPass) {
assert((ILE->getType() != SemaRef.Context.VoidTy) &&
"Should not have void type");
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);
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);
break;
}
}
} else {
unsigned Init = 0;
for (auto *Field : RDecl->fields()) {
if (Field->isUnnamedBitfield())
continue;
if (hadError)
return;
FillInEmptyInitForField(Init, Field, Entity, ILE, RequiresSecondPass);
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 ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType))
NumElements = CAType->getSize().getZExtValue();
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();
for (unsigned Init = 0; Init != NumElements; ++Init) {
if (hadError)
return;
if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement ||
ElementEntity.getKind() == InitializedEntity::EK_VectorElement)
ElementEntity.setElementIndex(Init);
Expr *InitExpr = (Init < NumInits ? ILE->getInit(Init) : nullptr);
if (!InitExpr && !ILE->hasArrayFiller()) {
ExprResult ElementInit = PerformEmptyInit(SemaRef, ILE->getLocEnd(),
ElementEntity,
/*VerifyOnly*/false);
if (ElementInit.isInvalid()) {
hadError = true;
return;
}
if (hadError) {
// Do nothing
} 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(ElementInit.getAs<Expr>());
else
ILE->setInit(Init, ElementInit.getAs<Expr>());
} 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(ElementInit.getAs<Expr>());
return;
}
if (!isa<ImplicitValueInitExpr>(ElementInit.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, ElementInit.getAs<Expr>());
RequiresSecondPass = true;
}
}
} else if (InitListExpr *InnerILE
= dyn_cast_or_null<InitListExpr>(InitExpr))
FillInEmptyInitializations(ElementEntity, InnerILE, RequiresSecondPass);
}
}
InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity,
InitListExpr *IL, QualType &T,
bool VerifyOnly)
: SemaRef(S), VerifyOnly(VerifyOnly) {
hadError = false;
FullyStructuredList =
getStructuredSubobjectInit(IL, 0, T, nullptr, 0, IL->getSourceRange());
CheckExplicitInitList(Entity, IL, T, FullyStructuredList,
/*TopLevelObject=*/true);
if (!hadError && !VerifyOnly) {
bool RequiresSecondPass = false;
FillInEmptyInitializations(Entity, FullyStructuredList, RequiresSecondPass);
if (RequiresSecondPass && !hadError)
FillInEmptyInitializations(Entity, FullyStructuredList,
RequiresSecondPass);
}
}
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->getAs<RecordType>()->getDecl();
int InitializableMembers = 0;
for (const auto *Field : structDecl->fields())
if (!Field->isUnnamedBitfield())
++InitializableMembers;
if (structDecl->isUnion())
return std::min(InitializableMembers, 1);
return InitializableMembers - structDecl->hasFlexibleArrayMember();
}
/// 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->getAs<VectorType>()->getNumElements();
else
llvm_unreachable("CheckImplicitInitList(): Illegal type");
if (maxElements == 0) {
if (!VerifyOnly)
SemaRef.Diag(ParentIList->getInit(Index)->getLocStart(),
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)->getLocStart(),
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 (!VerifyOnly) {
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()) {
SourceLocation EndLoc
= ParentIList->getInit(EndIndex)->getSourceRange().getEnd();
StructuredSubobjectInitList->setRBraceLoc(EndLoc);
}
// Complain about missing braces.
if (T->isArrayType() || T->isRecordType()) {
SemaRef.Diag(StructuredSubobjectInitList->getLocStart(),
diag::warn_missing_braces)
<< StructuredSubobjectInitList->getSourceRange()
<< FixItHint::CreateInsertion(
StructuredSubobjectInitList->getLocStart(), "{")
<< FixItHint::CreateInsertion(
SemaRef.getLocForEndOfToken(
StructuredSubobjectInitList->getLocEnd()),
"}");
}
}
}
/// 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) {
if (!VerifyOnly) {
SyntacticToSemantic[IList] = StructuredList;
StructuredList->setSyntacticForm(IList);
}
unsigned Index = 0, StructuredIndex = 0;
CheckListElementTypes(Entity, IList, T, /*SubobjectIsDesignatorContext=*/true,
Index, StructuredList, StructuredIndex, TopLevelObject);
if (!VerifyOnly) {
QualType ExprTy = T;
if (!ExprTy->isArrayType())
ExprTy = ExprTy.getNonLValueExprType(SemaRef.Context);
IList->setType(ExprTy);
StructuredList->setType(ExprTy);
}
if (hadError)
return;
if (Index < IList->getNumInits()) {
// We have leftover initializers
if (VerifyOnly) {
if (SemaRef.getLangOpts().CPlusPlus ||
(SemaRef.getLangOpts().OpenCL &&
IList->getType()->isVectorType())) {
hadError = true;
}
return;
}
if (StructuredIndex == 1 &&
IsStringInit(StructuredList->getInit(0), T, SemaRef.Context) ==
SIF_None) {
unsigned DK = diag::ext_excess_initializers_in_char_array_initializer;
if (SemaRef.getLangOpts().CPlusPlus) {
DK = diag::err_excess_initializers_in_char_array_initializer;
hadError = true;
}
// Special-case
SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK)
<< IList->getInit(Index)->getSourceRange();
} else if (!T->isIncompleteType()) {
// Don't complain for incomplete types, since we'll get an error
// elsewhere
QualType CurrentObjectType = StructuredList->getType();
int initKind =
CurrentObjectType->isArrayType()? 0 :
CurrentObjectType->isVectorType()? 1 :
CurrentObjectType->isScalarType()? 2 :
CurrentObjectType->isUnionType()? 3 :
4;
unsigned DK = diag::ext_excess_initializers;
if (SemaRef.getLangOpts().CPlusPlus) {
DK = diag::err_excess_initializers;
hadError = true;
}
if (SemaRef.getLangOpts().OpenCL && initKind == 1) {
DK = diag::err_excess_initializers;
hadError = true;
}
SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK)
<< initKind << IList->getInit(Index)->getSourceRange();
}
}
if (!VerifyOnly && T->isScalarType() && IList->getNumInits() == 1 &&
!TopLevelObject)
SemaRef.Diag(IList->getLocStart(), diag::warn_braces_around_scalar_init)
<< IList->getSourceRange()
<< FixItHint::CreateRemoval(IList->getLocStart())
<< FixItHint::CreateRemoval(IList->getLocEnd());
}
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->getAs<RecordType>()->getDecl();
CheckStructUnionTypes(Entity, IList, DeclType, 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->getLocStart(), 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->getLocStart(), diag::err_init_objc_class)
<< DeclType;
hadError = true;
} else {
if (!VerifyOnly)
SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type)
<< DeclType;
hadError = true;
}
}
void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
InitListExpr *IList,
QualType ElemType,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex) {
Expr *expr = IList->getInit(Index);
if (ElemType->isReferenceType())
return CheckReferenceType(Entity, IList, ElemType, Index,
StructuredList, StructuredIndex);
if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) {
if (!ElemType->isRecordType() || ElemType->isAggregateType()) {
InitListExpr *InnerStructuredList
= getStructuredSubobjectInit(IList, Index, ElemType,
StructuredList, StructuredIndex,
SubInitList->getSourceRange());
CheckExplicitInitList(Entity, SubInitList, ElemType,
InnerStructuredList);
++StructuredIndex;
++Index;
return;
}
assert(SemaRef.getLangOpts().CPlusPlus &&
"non-aggregate records are only possible in C++");
// C++ initialization is 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");
if (!VerifyOnly)
UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
++Index;
return;
}
// FIXME: Need to handle atomic aggregate types with implicit init lists.
if (ElemType->isScalarType() || ElemType->isAtomicType())
return CheckScalarType(Entity, IList, ElemType, Index,
StructuredList, StructuredIndex);
assert((ElemType->isRecordType() || ElemType->isVectorType() ||
ElemType->isArrayType()) && "Unexpected type");
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) {
if (!VerifyOnly) {
CheckStringInit(expr, ElemType, arrayType, SemaRef);
UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
}
++Index;
return;
}
// Fall through for subaggregate initialization.
} else if (SemaRef.getLangOpts().CPlusPlus) {
// C++ [dcl.init.aggr]p12:
// All implicit type conversions (clause 4) are considered when
// initializing the aggregate member with an initializer from
// an initializer-list. If the initializer can initialize a
// member, the member is initialized. [...]
// FIXME: Better EqualLoc?
InitializationKind Kind =
InitializationKind::CreateCopy(expr->getLocStart(), SourceLocation());
InitializationSequence Seq(SemaRef, Entity, Kind, expr);
if (Seq) {
if (!VerifyOnly) {
ExprResult Result =
Seq.Perform(SemaRef, Entity, Kind, expr);
if (Result.isInvalid())
hadError = true;
UpdateStructuredListElement(StructuredList, StructuredIndex,
Result.getAs<Expr>());
}
++Index;
return;
}
// Fall through for subaggregate initialization
} else {
// 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 ((ElemType->isRecordType() || ElemType->isVectorType()) &&
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.
if (!SemaRef.getLangOpts().OpenCL &&
(ElemType->isAggregateType() || ElemType->isVectorType())) {
CheckImplicitInitList(Entity, IList, ElemType, Index, StructuredList,
StructuredIndex);
++StructuredIndex;
} else {
if (!VerifyOnly) {
// We cannot initialize this element, so let
// PerformCopyInitialization produce the appropriate diagnostic.
SemaRef.PerformCopyInitialization(Entity, SourceLocation(), expr,
/*TopLevelOfInitList=*/true);
}
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->getLocStart(), diag::ext_complex_component_init)
<< IList->getSourceRange();
// Initialize the complex number.
QualType elementType = DeclType->getAs<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)
SemaRef.Diag(IList->getLocStart(),
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->getLocStart(),
diag::ext_many_braces_around_scalar_init)
<< SubIList->getSourceRange();
CheckScalarType(Entity, SubIList, DeclType, Index, StructuredList,
StructuredIndex);
return;
} else if (isa<DesignatedInitExpr>(expr)) {
if (!VerifyOnly)
SemaRef.Diag(expr->getLocStart(),
diag::err_designator_for_scalar_init)
<< DeclType << expr->getSourceRange();
hadError = true;
++Index;
++StructuredIndex;
return;
}
if (VerifyOnly) {
if (!SemaRef.CanPerformCopyInitialization(Entity,expr))
hadError = true;
++Index;
return;
}
ExprResult Result =
SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), expr,
/*TopLevelOfInitList=*/true);
Expr *ResultExpr = nullptr;
if (Result.isInvalid())
hadError = true; // types weren't compatible.
else {
ResultExpr = Result.getAs<Expr>();
if (ResultExpr != expr) {
// The type was promoted, update initializer list.
IList->setInit(Index, ResultExpr);
}
}
if (hadError)
++StructuredIndex;
else
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->getLocStart(),
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->getLocStart(), diag::err_init_non_aggr_init_list)
<< DeclType << IList->getSourceRange();
hadError = true;
++Index;
++StructuredIndex;
return;
}
if (VerifyOnly) {
if (!SemaRef.CanPerformCopyInitialization(Entity,expr))
hadError = true;
++Index;
return;
}
ExprResult Result =
SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), expr,
/*TopLevelOfInitList=*/true);
if (Result.isInvalid())
hadError = true;
expr = Result.getAs<Expr>();
IList->setInit(Index, expr);
if (hadError)
++StructuredIndex;
else
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->getAs<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.
if (VerifyOnly)
CheckEmptyInitializable(
InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity),
IList->getLocEnd());
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()) {
if (VerifyOnly) {
if (!SemaRef.CanPerformCopyInitialization(Entity, Init))
hadError = true;
++Index;
return;
}
ExprResult Result =
SemaRef.PerformCopyInitialization(Entity, Init->getLocStart(), Init,
/*TopLevelOfInitList=*/true);
Expr *ResultExpr = nullptr;
if (Result.isInvalid())
hadError = true; // types weren't compatible.
else {
ResultExpr = Result.getAs<Expr>();
if (ResultExpr != Init) {
// The type was promoted, update initializer list.
IList->setInit(Index, ResultExpr);
}
}
if (hadError)
++StructuredIndex;
else
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()) {
if (VerifyOnly)
CheckEmptyInitializable(ElementEntity, IList->getLocEnd());
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()->getAs<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->getLocStart(),
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->getLocStart(),
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->getAs<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->getLocStart(),
diag::err_vector_incorrect_num_initializers)
<< (numEltsInit < maxElements) << maxElements << numEltsInit;
hadError = true;
}
}
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);
// 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.
if (!VerifyOnly) {
CheckStringInit(IList->getInit(Index), DeclType, arrayType, SemaRef);
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()->getLocStart(),
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) {
// Sizing an array implicitly to zero is not allowed by ISO C,
// but is supported by GNU.
SemaRef.Diag(IList->getLocStart(),
diag::ext_typecheck_zero_array_size);
}
DeclType = SemaRef.Context.getConstantArrayType(elementType, maxElements,
ArrayType::Normal, 0);
}
if (!hadError && VerifyOnly) {
// Check if there are any members of the array that get value-initialized.
// If so, check if doing that is possible.
// FIXME: This needs to detect holes left by designated initializers too.
if (maxElementsKnown && elementIndex < maxElements)
CheckEmptyInitializable(InitializedEntity::InitializeElement(
SemaRef.Context, 0, Entity),
IList->getLocEnd());
}
}
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->getLocStart(),
FlexArrayDiag)
<< InitExpr->getLocStart();
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,
RecordDecl::field_iterator Field,
bool SubobjectIsDesignatorContext,
unsigned &Index,
InitListExpr *StructuredList,
unsigned &StructuredIndex,
bool TopLevelObject) {
RecordDecl* structDecl = DeclType->getAs<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->getAs<RecordType>()->getDecl();
// If there's a default initializer, use it.
if (isa<CXXRecordDecl>(RD) && cast<CXXRecordDecl>(RD)->hasInClassInitializer()) {
if (VerifyOnly)
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 named member of the union.
for (RecordDecl::field_iterator FieldEnd = RD->field_end();
Field != FieldEnd; ++Field) {
if (Field->getDeclName()) {
if (VerifyOnly)
CheckEmptyInitializable(
InitializedEntity::InitializeMember(*Field, &Entity),
IList->getLocEnd());
else
StructuredList->setInitializedFieldInUnion(*Field);
break;
}
}
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->getAs<RecordType>()->getDecl();
RecordDecl::field_iterator FieldEnd = RD->field_end();
bool InitializedSomething = false;
bool CheckForMissingFields = true;
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. 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;
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);
else
InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field,
IList->getInit(Index)->getLocStart());
if (InvalidUse) {
++Index;
++Field;
hadError = true;
continue;
}
InitializedEntity MemberEntity =
InitializedEntity::InitializeMember(*Field, &Entity);
CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
StructuredList, StructuredIndex);
InitializedSomething = true;
if (DeclType->isUnionType() && !VerifyOnly) {
// 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 (VerifyOnly && Field != FieldEnd && !DeclType->isUnionType() &&
!Field->getType()->isIncompleteArrayType()) {
// FIXME: Should check for holes left by designated initializers too.
for (; Field != FieldEnd && !hadError; ++Field) {
if (!Field->isUnnamedBitfield() && !Field->hasInClassInitializer())
CheckEmptyInitializable(
InitializedEntity::InitializeMember(*Field, &Entity),
IList->getLocEnd());
}
}
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);
}
/// \brief 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_begin(),
DIE->size(), 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 : 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);
}
private:
RecordDecl *Record;
};
}
/// @brief 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.
///
/// @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()) {
// 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);
// 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 (!VerifyOnly) {
assert((IsFirstDesignator || StructuredList) &&
"Need a non-designated initializer list to start from");
// Determine the structural initializer list that corresponds to the
// current subobject.
StructuredList = IsFirstDesignator? SyntacticToSemantic.lookup(IList)
: getStructuredSubobjectInit(IList, Index, CurrentObjectType,
StructuredList, StructuredIndex,
SourceRange(D->getLocStart(),
DIE->getLocEnd()));
assert(StructuredList && "Expected a structured initializer list");
}
if (D->isFieldDesignator()) {
// C99 6.7.8p7:
//
// If a designator has the form
//
// . identifier
//
// then the current object (defined below) shall have
// structure or union type and the identifier shall be the
// name of a member of that type.
const RecordType *RT = CurrentObjectType->getAs<RecordType>();
if (!RT) {
SourceLocation Loc = D->getDotLoc();
if (Loc.isInvalid())
Loc = D->getFieldLoc();
if (!VerifyOnly)
SemaRef.Diag(Loc, diag::err_field_designator_non_aggr)
<< SemaRef.getLangOpts().CPlusPlus << CurrentObjectType;
++Index;
return true;
}
FieldDecl *KnownField = D->getField();
if (!KnownField) {
IdentifierInfo *FieldName = D->getFieldName();
DeclContext::lookup_result Lookup = RT->getDecl()->lookup(FieldName);
for (NamedDecl *ND : Lookup) {
if (auto *FD = dyn_cast<FieldDecl>(ND)) {
KnownField = FD;
break;
}
if (auto *IFD = dyn_cast<IndirectFieldDecl>(ND)) {
// In verify mode, don't modify the original.
if (VerifyOnly)
DIE = CloneDesignatedInitExpr(SemaRef, DIE);
ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, IFD);
D = DIE->getDesignator(DesigIdx);
KnownField = cast<FieldDecl>(*IFD->chain_begin());
break;
}
}
if (!KnownField) {
if (VerifyOnly) {
++Index;
return true; // No typo correction when just trying this out.
}
// Name lookup found something, but it wasn't a field.
if (!Lookup.empty()) {
SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_nonfield)
<< FieldName;
SemaRef.Diag(Lookup.front()->getLocation(),
diag::note_field_designator_found);
++Index;
return true;
}
// Name lookup didn't find anything.
// Determine whether this was a typo for another field name.
if (TypoCorrection Corrected = SemaRef.CorrectTypo(
DeclarationNameInfo(FieldName, D->getFieldLoc()),
Sema::LookupMemberName, /*Scope=*/nullptr, /*SS=*/nullptr,
llvm::make_unique<FieldInitializerValidatorCCC>(RT->getDecl()),
Sema::CTK_ErrorRecovery, RT->getDecl())) {
SemaRef.diagnoseTypo(
Corrected,
SemaRef.PDiag(diag::err_field_designator_unknown_suggest)
<< FieldName << CurrentObjectType);
KnownField = Corrected.getCorrectionDeclAs<FieldDecl>();
hadError = true;
} else {
// Typo correction didn't find anything.
SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown)
<< FieldName << CurrentObjectType;
++Index;
return true;
}
}
}
unsigned FieldIndex = 0;
for (auto *FI : RT->getDecl()->fields()) {
if (FI->isUnnamedBitfield())
continue;
if (KnownField == FI)
break;
++FieldIndex;
}
RecordDecl::field_iterator Field =
RecordDecl::field_iterator(DeclContext::decl_iterator(KnownField));
// All of the fields of a union are located at the same place in
// the initializer list.
if (RT->getDecl()->isUnion()) {
FieldIndex = 0;
if (!VerifyOnly) {
FieldDecl *CurrentField = StructuredList->getInitializedFieldInUnion();
if (CurrentField && CurrentField != *Field) {
assert(StructuredList->getNumInits() == 1
&& "A union should never have more than one initializer!");
// we're about to throw away an initializer, emit warning
SemaRef.Diag(D->getFieldLoc(),
diag::warn_initializer_overrides)
<< D->getSourceRange();
Expr *ExistingInit = StructuredList->getInit(0);
SemaRef.Diag(ExistingInit->getLocStart(),
diag::note_previous_initializer)
<< /*FIXME:has side effects=*/0
<< ExistingInit->getSourceRange();
// remove existing initializer
StructuredList->resizeInits(SemaRef.Context, 0);
StructuredList->setInitializedFieldInUnion(nullptr);
}
StructuredList->setInitializedFieldInUnion(*Field);
}
}
// Make sure we can use this declaration.
bool InvalidUse;
if (VerifyOnly)
InvalidUse = !SemaRef.CanUseDecl(*Field);
else
InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field, D->getFieldLoc());
if (InvalidUse) {
++Index;
return true;
}
if (!VerifyOnly) {
// Update the designator with the field declaration.
D->setField(*Field);
// Make sure that our non-designated initializer list has space
// for a subobject corresponding to this field.
if (FieldIndex >= StructuredList->getNumInits())
StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1);
}
// This designator names a flexible array member.
if (Field->getType()->isIncompleteArrayType()) {
bool Invalid = false;
if ((DesigIdx + 1) != DIE->size()) {
// We can't designate an object within the flexible array
// member (because GCC doesn't allow it).
if (!VerifyOnly) {
DesignatedInitExpr::Designator *NextD
= DIE->getDesignator(DesigIdx + 1);
SemaRef.Diag(NextD->getLocStart(),
diag::err_designator_into_flexible_array_member)
<< SourceRange(NextD->getLocStart(),
DIE->getLocEnd());
SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
<< *Field;
}
Invalid = true;
}
if (!hadError && !isa<InitListExpr>(DIE->getInit()) &&
!isa<StringLiteral>(DIE->getInit())) {
// The initializer is not an initializer list.
if (!VerifyOnly) {
SemaRef.Diag(DIE->getInit()->getLocStart(),
diag::err_flexible_array_init_needs_braces)
<< DIE->getInit()->getSourceRange();
SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
<< *Field;
}
Invalid = true;
}
// Check GNU flexible array initializer.
if (!Invalid && CheckFlexibleArrayInit(Entity, DIE->getInit(), *Field,
TopLevelObject))
Invalid = true;
if (Invalid) {
++Index;
return true;
}
// Initialize the array.
bool prevHadError = hadError;
unsigned newStructuredIndex = FieldIndex;
unsigned OldIndex = Index;
IList->setInit(Index, DIE->getInit());
InitializedEntity MemberEntity =
InitializedEntity::InitializeMember(*Field, &Entity);
CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
StructuredList, newStructuredIndex);
IList->setInit(OldIndex, DIE);
if (hadError && !prevHadError) {
++Field;
++FieldIndex;
if (NextField)
*NextField = Field;
StructuredIndex = FieldIndex;
return true;
}
} else {
// Recurse to check later designated subobjects.
QualType FieldType = Field->getType();
unsigned newStructuredIndex = FieldIndex;
InitializedEntity MemberEntity =
InitializedEntity::InitializeMember(*Field, &Entity);
if (CheckDesignatedInitializer(MemberEntity, IList, DIE, DesigIdx + 1,
FieldType, nullptr, nullptr, Index,
StructuredList, newStructuredIndex,
true, false))
return true;
}
// Find the position of the next field to be initialized in this
// subobject.
++Field;
++FieldIndex;
// If this the first designator, our caller will continue checking
// the rest of this struct/class/union subobject.
if (IsFirstDesignator) {
if (NextField)
*NextField = Field;
StructuredIndex = FieldIndex;
return false;
}
if (!FinishSubobjectInit)
return false;
// We've already initialized something in the union; we're done.
if (RT->getDecl()->isUnion())
return hadError;
// Check the remaining fields within this class/struct/union subobject.
bool prevHadError = hadError;
CheckStructUnionTypes(Entity, IList, CurrentObjectType, Field, false, Index,
StructuredList, FieldIndex);
return hadError && !prevHadError;
}
// C99 6.7.8p6:
//
// If a designator has the form
//
// [ constant-expression ]
//
// then the current object (defined below) shall have array
// type and the expression shall be an integer constant
// expression. If the array is of unknown size, any
// nonnegative value is valid.
//
// Additionally, cope with the GNU extension that permits
// designators of the form
//
// [ constant-expression ... constant-expression ]
const ArrayType *AT = SemaRef.Context.getAsArrayType(CurrentObjectType);
if (!AT) {
if (!VerifyOnly)
SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array)
<< CurrentObjectType;
++Index;
return true;
}
Expr *IndexExpr = nullptr;
llvm::APSInt DesignatedStartIndex, DesignatedEndIndex;
if (D->isArrayDesignator()) {
IndexExpr = DIE->getArrayIndex(*D);
DesignatedStartIndex = IndexExpr->EvaluateKnownConstInt(SemaRef.Context);
DesignatedEndIndex = DesignatedStartIndex;
} else {
assert(D->isArrayRangeDesignator() && "Need array-range designator");
DesignatedStartIndex =
DIE->getArrayRangeStart(*D)->EvaluateKnownConstInt(SemaRef.Context);
DesignatedEndIndex =
DIE->getArrayRangeEnd(*D)->EvaluateKnownConstInt(SemaRef.Context);
IndexExpr = DIE->getArrayRangeEnd(*D);
// Codegen can't handle evaluating array range designators that have side
// effects, because we replicate the AST value for each initialized element.
// As such, set the sawArrayRangeDesignator() bit if we initialize multiple
// elements with something that has a side effect, so codegen can emit an
// "error unsupported" error instead of miscompiling the app.
if (DesignatedStartIndex.getZExtValue()!=DesignatedEndIndex.getZExtValue()&&
DIE->getInit()->HasSideEffects(SemaRef.Context) && !VerifyOnly)
FullyStructuredList->sawArrayRangeDesignator();
}
if (isa<ConstantArrayType>(AT)) {
llvm::APSInt MaxElements(cast<ConstantArrayType>(AT)->getSize(), false);
DesignatedStartIndex
= DesignatedStartIndex.extOrTrunc(MaxElements.getBitWidth());
DesignatedStartIndex.setIsUnsigned(MaxElements.isUnsigned());
DesignatedEndIndex
= DesignatedEndIndex.extOrTrunc(MaxElements.getBitWidth());
DesignatedEndIndex.setIsUnsigned(MaxElements.isUnsigned());
if (DesignatedEndIndex >= MaxElements) {
if (!VerifyOnly)
SemaRef.Diag(IndexExpr->getLocStart(),
diag::err_array_designator_too_large)
<< DesignatedEndIndex.toString(10) << MaxElements.toString(10)
<< IndexExpr->getSourceRange();
++Index;
return true;
}
} else {
// Make sure the bit-widths and signedness match.
if (DesignatedStartIndex.getBitWidth() > DesignatedEndIndex.getBitWidth())
DesignatedEndIndex
= DesignatedEndIndex.extend(DesignatedStartIndex.getBitWidth());
else if (DesignatedStartIndex.getBitWidth() <
DesignatedEndIndex.getBitWidth())
DesignatedStartIndex
= DesignatedStartIndex.extend(DesignatedEndIndex.getBitWidth());
DesignatedStartIndex.setIsUnsigned(true);
DesignatedEndIndex.setIsUnsigned(true);
}
if (!VerifyOnly && StructuredList->isStringLiteralInit()) {
// We're modifying a string literal init; we have to decompose the string
// so we can modify the individual characters.
ASTContext &Context = SemaRef.Context;
Expr *SubExpr = StructuredList->getInit(0)->IgnoreParens();
// Compute the character type
QualType CharTy = AT->getElementType();
// Compute the type of the integer literals.
QualType PromotedCharTy = CharTy;
if (CharTy->isPromotableIntegerType())
PromotedCharTy = Context.getPromotedIntegerType(CharTy);
unsigned PromotedCharTyWidth = Context.getTypeSize(PromotedCharTy);
if (StringLiteral *SL = dyn_cast<StringLiteral>(SubExpr)) {
// Get the length of the string.
uint64_t StrLen = SL->getLength();
if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen))
StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue();
StructuredList->resizeInits(Context, StrLen);
// Build a literal for each character in the string, and put them into
// the init list.
for (unsigned i = 0, e = StrLen; i != e; ++i) {
llvm::APInt CodeUnit(PromotedCharTyWidth, SL->getCodeUnit(i));
Expr *Init = new (Context) IntegerLiteral(
Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc());
if (CharTy != PromotedCharTy)
Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast,
Init, nullptr, VK_RValue);
StructuredList->updateInit(Context, i, Init);
}
} else {
ObjCEncodeExpr *E = cast<ObjCEncodeExpr>(SubExpr);
std::string Str;
Context.getObjCEncodingForType(E->getEncodedType(), Str);
// Get the length of the string.
uint64_t StrLen = Str.size();
if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen))
StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue();
StructuredList->resizeInits(Context, StrLen);
// Build a literal for each character in the string, and put them into
// the init list.
for (unsigned i = 0, e = StrLen; i != e; ++i) {
llvm::APInt CodeUnit(PromotedCharTyWidth, Str[i]);
Expr *Init = new (Context) IntegerLiteral(
Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc());
if (CharTy != PromotedCharTy)
Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast,
Init, nullptr, VK_RValue);
StructuredList->updateInit(Context, i, Init);
}
}
}
// Make sure that our non-designated initializer list has space
// for a subobject corresponding to this array element.
if (!VerifyOnly &&
DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits())
StructuredList->resizeInits(SemaRef.Context,
DesignatedEndIndex.getZExtValue() + 1);
// Repeatedly perform subobject initializations in the range
// [DesignatedStartIndex, DesignatedEndIndex].
// Move to the next designator
unsigned ElementIndex = DesignatedStartIndex.getZExtValue();
unsigned OldIndex = Index;
InitializedEntity ElementEntity =
InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
while (DesignatedStartIndex <= DesignatedEndIndex) {
// Recurse to check later designated subobjects.
QualType ElementType = AT->getElementType();
Index = OldIndex;
ElementEntity.setElementIndex(ElementIndex);
if (CheckDesignatedInitializer(ElementEntity, IList, DIE, DesigIdx + 1,
ElementType, nullptr, nullptr, Index,
StructuredList, ElementIndex,
(DesignatedStartIndex == DesignatedEndIndex),
false))
return true;
// Move to the next index in the array that we'll be initializing.
++DesignatedStartIndex;
ElementIndex = DesignatedStartIndex.getZExtValue();
}
// If this the first designator, our caller will continue checking
// the rest of this array subobject.
if (IsFirstDesignator) {
if (NextElementIndex)
*NextElementIndex = DesignatedStartIndex;
StructuredIndex = ElementIndex;
return false;
}
if (!FinishSubobjectInit)
return false;
// Check the remaining elements within this array subobject.
bool prevHadError = hadError;
CheckArrayType(Entity, IList, CurrentObjectType, DesignatedStartIndex,
/*SubobjectIsDesignatorContext=*/false, Index,
StructuredList, ElementIndex);
return hadError && !prevHadError;
}
// Get the structured initializer list for a subobject of type
// @p CurrentObjectType.
InitListExpr *
InitListChecker::getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
QualType CurrentObjectType,
InitListExpr *StructuredList,
unsigned StructuredIndex,
SourceRange InitRange) {
if (VerifyOnly)
return nullptr; // No structured list in verification-only mode.
Expr *ExistingInit = nullptr;
if (!StructuredList)
ExistingInit = SyntacticToSemantic.lookup(IList);
else if (StructuredIndex < StructuredList->getNumInits())
ExistingInit = StructuredList->getInit(StructuredIndex);
if (InitListExpr *Result = dyn_cast_or_null<InitListExpr>(ExistingInit))
return Result;
if (ExistingInit) {
// We are creating an initializer list that initializes the
// subobjects of the current object, but there was already an
// initialization that completely initialized the current
// subobject, e.g., by a compound literal:
//
// struct X { int a, b; };
// struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 };
//
// Here, xs[0].a == 0 and xs[0].b == 3, since the second,
// designated initializer re-initializes the whole
// subobject [0], overwriting previous initializers.
SemaRef.Diag(InitRange.getBegin(),
diag::warn_subobject_initializer_overrides)
<< InitRange;
SemaRef.Diag(ExistingInit->getLocStart(),
diag::note_previous_initializer)
<< /*FIXME:has side effects=*/0
<< ExistingInit->getSourceRange();
}
InitListExpr *Result
= new (SemaRef.Context) InitListExpr(SemaRef.Context,
InitRange.getBegin(), None,
InitRange.getEnd());
QualType ResultType = CurrentObjectType;
if (!ResultType->isArrayType())
ResultType = ResultType.getNonLValueExprType(SemaRef.Context);
Result->setType(ResultType);
// Pre-allocate storage for the structured initializer list.
unsigned NumElements = 0;
unsigned NumInits = 0;
bool GotNumInits = false;
if (!StructuredList) {
NumInits = IList->getNumInits();
GotNumInits = true;
} else if (Index < IList->getNumInits()) {
if (InitListExpr *SubList = dyn_cast<InitListExpr>(IList->getInit(Index))) {
NumInits = SubList->getNumInits();
GotNumInits = true;
}
}
if (const ArrayType *AType
= SemaRef.Context.getAsArrayType(CurrentObjectType)) {
if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) {
NumElements = CAType->getSize().getZExtValue();
// Simple heuristic so that we don't allocate a very large
// initializer with many empty entries at the end.
if (GotNumInits && NumElements > NumInits)
NumElements = 0;
}
} else if (const VectorType *VType = CurrentObjectType->getAs<VectorType>())
NumElements = VType->getNumElements();
else if (const RecordType *RType = CurrentObjectType->getAs<RecordType>()) {
RecordDecl *RDecl = RType->getDecl();
if (RDecl->isUnion())
NumElements = 1;
else
NumElements = std::distance(RDecl->field_begin(), RDecl->field_end());
}
Result->reserveInits(SemaRef.Context, NumElements);
// Link this new initializer list into the structured initializer
// lists.
if (StructuredList)
StructuredList->updateInit(SemaRef.Context, StructuredIndex, Result);
else {
Result->setSyntacticForm(IList);
SyntacticToSemantic[IList] = Result;
}
return Result;
}
/// Update the initializer at index @p StructuredIndex within the
/// structured initializer list to the value @p expr.
void InitListChecker::UpdateStructuredListElement(InitListExpr *StructuredList,
unsigned &StructuredIndex,
Expr *expr) {
// No structured initializer list to update
if (!StructuredList)
return;
if (Expr *PrevInit = StructuredList->updateInit(SemaRef.Context,
StructuredIndex, expr)) {
// This initializer overwrites a previous initializer. Warn.
SemaRef.Diag(expr->getLocStart(),
diag::warn_initializer_overrides)
<< expr->getSourceRange();
SemaRef.Diag(PrevInit->getLocStart(),
diag::note_previous_initializer)
<< /*FIXME:has side effects=*/0
<< PrevInit->getSourceRange();
}
++StructuredIndex;
}
/// Check that the given Index expression is a valid array designator
/// value. This is essentially just a wrapper around
/// VerifyIntegerConstantExpression that also checks for negative values
/// and produces a reasonable diagnostic if there is a
/// failure. Returns the index expression, possibly with an implicit cast
/// added, on success. If everything went okay, Value will receive the
/// value of the constant expression.
static ExprResult
CheckArrayDesignatorExpr(Sema &S, Expr *Index, llvm::APSInt &Value) {
SourceLocation Loc = Index->getLocStart();
// Make sure this is an integer constant expression.
ExprResult Result = S.VerifyIntegerConstantExpression(Index, &Value);
if (Result.isInvalid())
return Result;
if (Value.isSigned() && Value.isNegative())
return S.Diag(Loc, diag::err_array_designator_negative)
<< Value.toString(10) << Index->getSourceRange();
Value.setIsUnsigned(true);
return Result;
}
ExprResult Sema::ActOnDesignatedInitializer(Designation &Desig,
SourceLocation Loc,
bool GNUSyntax,
ExprResult Init) {
typedef DesignatedInitExpr::Designator ASTDesignator;
bool Invalid = false;
SmallVector<ASTDesignator, 32> Designators;
SmallVector<Expr *, 32> InitExpressions;
// Build designators and check array designator expressions.
for (unsigned Idx = 0; Idx < Desig.getNumDesignators(); ++Idx) {
const Designator &D = Desig.getDesignator(Idx);
switch (D.getKind()) {
case Designator::FieldDesignator:
Designators.push_back(ASTDesignator(D.getField(), D.getDotLoc(),
D.getFieldLoc()));
break;
case Designator::ArrayDesignator: {
Expr *Index = static_cast<Expr *>(D.getArrayIndex());
llvm::APSInt IndexValue;
if (!Index->isTypeDependent() && !Index->isValueDependent())
Index = CheckArrayDesignatorExpr(*this, Index, IndexValue).get();
if (!Index)
Invalid = true;
else {
Designators.push_back(ASTDesignator(InitExpressions.size(),
D.getLBracketLoc(),
D.getRBracketLoc()));
InitExpressions.push_back(Index);
}
break;
}
case Designator::ArrayRangeDesignator: {
Expr *StartIndex = static_cast<Expr *>(D.getArrayRangeStart());
Expr *EndIndex = static_cast<Expr *>(D.getArrayRangeEnd());
llvm::APSInt StartValue;
llvm::APSInt EndValue;
bool StartDependent = StartIndex->isTypeDependent() ||
StartIndex->isValueDependent();
bool EndDependent = EndIndex->isTypeDependent() ||
EndIndex->isValueDependent();
if (!StartDependent)
StartIndex =
CheckArrayDesignatorExpr(*this, StartIndex, StartValue).get();
if (!EndDependent)
EndIndex = CheckArrayDesignatorExpr(*this, EndIndex, EndValue).get();
if (!StartIndex || !EndIndex)
Invalid = true;
else {
// Make sure we're comparing values with the same bit width.
if (StartDependent || EndDependent) {
// Nothing to compute.
} else if (StartValue.getBitWidth() > EndValue.getBitWidth())
EndValue = EndValue.extend(StartValue.getBitWidth());
else if (StartValue.getBitWidth() < EndValue.getBitWidth())
StartValue = StartValue.extend(EndValue.getBitWidth());
if (!StartDependent && !EndDependent && EndValue < StartValue) {
Diag(D.getEllipsisLoc(), diag::err_array_designator_empty_range)
<< StartValue.toString(10) << EndValue.toString(10)
<< StartIndex->getSourceRange() << EndIndex->getSourceRange();
Invalid = true;
} else {
Designators.push_back(ASTDesignator(InitExpressions.size(),
D.getLBracketLoc(),
D.getEllipsisLoc(),
D.getRBracketLoc()));
InitExpressions.push_back(StartIndex);
InitExpressions.push_back(EndIndex);
}
}
break;
}
}
}
if (Invalid || Init.isInvalid())
return ExprError();
// Clear out the expressions within the designation.
Desig.ClearExprs(*this);
DesignatedInitExpr *DIE
= DesignatedInitExpr::Create(Context,
Designators.data(), Designators.size(),
InitExpressions, Loc, GNUSyntax,
Init.getAs<Expr>());
if (!getLangOpts().C99)
Diag(DIE->getLocStart(), diag::ext_designated_init)
<< DIE->getSourceRange();
return DIE;
}
//===----------------------------------------------------------------------===//
// Initialization entity
//===----------------------------------------------------------------------===//
InitializedEntity::InitializedEntity(ASTContext &Context, unsigned Index,
const InitializedEntity &Parent)
: Parent(&Parent), Index(Index)
{
if (const ArrayType *AT = Context.getAsArrayType(Parent.getType())) {
Kind = EK_ArrayElement;
Type = AT->getElementType();
} else if (const VectorType *VT = Parent.getType()->getAs<VectorType>()) {
Kind = EK_VectorElement;
Type = VT->getElementType();
} else {
const ComplexType *CT = Parent.getType()->getAs<ComplexType>();
assert(CT && "Unexpected type");
Kind = EK_ComplexElement;
Type = CT->getElementType();
}
}
InitializedEntity
InitializedEntity::InitializeBase(ASTContext &Context,
const CXXBaseSpecifier *Base,
bool IsInheritedVirtualBase) {
InitializedEntity Result;
Result.Kind = EK_Base;
Result.Parent = nullptr;
Result.Base = reinterpret_cast<uintptr_t>(Base);
if (IsInheritedVirtualBase)
Result.Base |= 0x01;
Result.Type = Base->getType();
return Result;
}
DeclarationName InitializedEntity::getName() const {
switch (getKind()) {
case EK_Parameter:
case EK_Parameter_CF_Audited: {
ParmVarDecl *D = reinterpret_cast<ParmVarDecl*>(Parameter & ~0x1);
return (D ? D->getDeclName() : DeclarationName());
}
case EK_Variable:
case EK_Member:
return VariableOrMember->getDeclName();
case EK_LambdaCapture:
return DeclarationName(Capture.VarID);
case EK_Result:
case EK_Exception:
case EK_New:
case EK_Temporary:
case EK_Base:
case EK_Delegating:
case EK_ArrayElement:
case EK_VectorElement:
case EK_ComplexElement:
case EK_BlockElement:
case EK_CompoundLiteralInit:
case EK_RelatedResult:
return DeclarationName();
}
llvm_unreachable("Invalid EntityKind!");
}
DeclaratorDecl *InitializedEntity::getDecl() const {
switch (getKind()) {
case EK_Variable:
case EK_Member:
return VariableOrMember;
case EK_Parameter:
case EK_Parameter_CF_Audited:
return reinterpret_cast<ParmVarDecl*>(Parameter & ~0x1);
case EK_Result:
case EK_Exception:
case EK_New:
case EK_Temporary:
case EK_Base:
case EK_Delegating:
case EK_ArrayElement:
case EK_VectorElement:
case EK_ComplexElement:
case EK_BlockElement:
case EK_LambdaCapture:
case EK_CompoundLiteralInit:
case EK_RelatedResult:
return nullptr;
}
llvm_unreachable("Invalid EntityKind!");
}
bool InitializedEntity::allowsNRVO() const {
switch (getKind()) {
case EK_Result:
case EK_Exception:
return LocAndNRVO.NRVO;
case EK_Variable:
case EK_Parameter:
case EK_Parameter_CF_Audited:
case EK_Member:
case EK_New:
case EK_Temporary:
case EK_CompoundLiteralInit:
case EK_Base:
case EK_Delegating:
case EK_ArrayElement:
case EK_VectorElement:
case EK_ComplexElement:
case EK_BlockElement:
case EK_LambdaCapture:
case EK_RelatedResult:
break;
}
return false;
}
unsigned InitializedEntity::dumpImpl(raw_ostream &OS) const {
assert(getParent() != this);
unsigned Depth = getParent() ? getParent()->dumpImpl(OS) : 0;
for (unsigned I = 0; I != Depth; ++I)
OS << "`-";
switch (getKind()) {
case EK_Variable: OS << "Variable"; break;
case EK_Parameter: OS << "Parameter"; break;
case EK_Parameter_CF_Audited: OS << "CF audited function Parameter";
break;
case EK_Result: OS << "Result"; break;
case EK_Exception: OS << "Exception"; break;
case EK_Member: OS << "Member"; break;
case EK_New: OS << "New"; break;
case EK_Temporary: OS << "Temporary"; break;
case EK_CompoundLiteralInit: OS << "CompoundLiteral";break;
case EK_RelatedResult: OS << "RelatedResult"; break;
case EK_Base: OS << "Base"; break;
case EK_Delegating: OS << "Delegating"; break;
case EK_ArrayElement: OS << "ArrayElement " << Index; break;
case EK_VectorElement: OS << "VectorElement " << Index; break;
case EK_ComplexElement: OS << "ComplexElement " << Index; break;
case EK_BlockElement: OS << "Block"; break;
case EK_LambdaCapture:
OS << "LambdaCapture ";
OS << DeclarationName(Capture.VarID);
break;
}
if (Decl *D = getDecl()) {
OS << " ";
cast<NamedDecl>(D)->printQualifiedName(OS);
}
OS << " '" << getType().getAsString() << "'\n";
return Depth + 1;
}
void InitializedEntity::dump() const {
dumpImpl(llvm::errs());
}
//===----------------------------------------------------------------------===//
// Initialization sequence
//===----------------------------------------------------------------------===//
void InitializationSequence::Step::Destroy() {
switch (Kind) {
case SK_ResolveAddressOfOverloadedFunction:
case SK_CastDerivedToBaseRValue:
case SK_CastDerivedToBaseXValue:
case SK_CastDerivedToBaseLValue:
case SK_BindReference:
case SK_BindReferenceToTemporary:
case SK_ExtraneousCopyToTemporary:
case SK_UserConversion:
case SK_QualificationConversionRValue:
case SK_QualificationConversionXValue:
case SK_QualificationConversionLValue:
case SK_AtomicConversion:
case SK_LValueToRValue:
case SK_ListInitialization:
case SK_UnwrapInitList:
case SK_RewrapInitList:
case SK_ConstructorInitialization:
case SK_ConstructorInitializationFromList:
case SK_ZeroInitialization:
case SK_CAssignment:
case SK_StringInit:
case SK_ObjCObjectConversion:
case SK_ArrayInit:
case SK_ParenthesizedArrayInit:
case SK_PassByIndirectCopyRestore:
case SK_PassByIndirectRestore:
case SK_ProduceObjCObject:
case SK_StdInitializerList:
case SK_StdInitializerListConstructorCall:
case SK_OCLSamplerInit:
case SK_OCLZeroEvent:
break;
case SK_ConversionSequence:
case SK_ConversionSequenceNoNarrowing:
delete ICS;
}
}
bool InitializationSequence::isDirectReferenceBinding() const {
return !Steps.empty() && Steps.back().Kind == SK_BindReference;
}
bool InitializationSequence::isAmbiguous() const {
if (!Failed())
return false;
switch (getFailureKind()) {
case FK_TooManyInitsForReference:
case FK_ArrayNeedsInitList:
case FK_ArrayNeedsInitListOrStringLiteral:
case FK_ArrayNeedsInitListOrWideStringLiteral:
case FK_NarrowStringIntoWideCharArray:
case FK_WideStringIntoCharArray:
case FK_IncompatWideStringIntoWideChar:
case FK_AddressOfOverloadFailed: // FIXME: Could do better
case FK_NonConstLValueReferenceBindingToTemporary:
case FK_NonConstLValueReferenceBindingToUnrelated:
case FK_RValueReferenceBindingToLValue:
case FK_ReferenceInitDropsQualifiers:
case FK_ReferenceInitFailed:
case FK_ConversionFailed:
case FK_ConversionFromPropertyFailed:
case FK_TooManyInitsForScalar:
case FK_ReferenceBindingToInitList:
case FK_InitListBadDestinationType:
case FK_DefaultInitOfConst:
case FK_Incomplete:
case FK_ArrayTypeMismatch:
case FK_NonConstantArrayInit:
case FK_ListInitializationFailed:
case FK_VariableLengthArrayHasInitializer:
case FK_PlaceholderType:
case FK_ExplicitConstructor:
return false;
case FK_ReferenceInitOverloadFailed:
case FK_UserConversionOverloadFailed:
case FK_ConstructorOverloadFailed:
case FK_ListConstructorOverloadFailed:
return FailedOverloadResult == OR_Ambiguous;
}
llvm_unreachable("Invalid EntityKind!");
}
bool InitializationSequence::isConstructorInitialization() const {
return !Steps.empty() && Steps.back().Kind == SK_ConstructorInitialization;
}
void
InitializationSequence
::AddAddressOverloadResolutionStep(FunctionDecl *Function,
DeclAccessPair Found,
bool HadMultipleCandidates) {
Step S;
S.Kind = SK_ResolveAddressOfOverloadedFunction;
S.Type = Function->getType();
S.Function.HadMultipleCandidates = HadMultipleCandidates;
S.Function.Function = Function;
S.Function.FoundDecl = Found;
Steps.push_back(S);
}
void InitializationSequence::AddDerivedToBaseCastStep(QualType BaseType,
ExprValueKind VK) {
Step S;
switch (VK) {
case VK_RValue: S.Kind = SK_CastDerivedToBaseRValue; break;
case VK_XValue: S.Kind = SK_CastDerivedToBaseXValue; break;
case VK_LValue: S.Kind = SK_CastDerivedToBaseLValue; break;
}
S.Type = BaseType;
Steps.push_back(S);
}
void InitializationSequence::AddReferenceBindingStep(QualType T,
bool BindingTemporary) {
Step S;
S.Kind = BindingTemporary? SK_BindReferenceToTemporary : SK_BindReference;
S.Type = T;
Steps.push_back(S);
}
void InitializationSequence::AddExtraneousCopyToTemporary(QualType T) {
Step S;
S.Kind = SK_ExtraneousCopyToTemporary;
S.Type = T;
Steps.push_back(S);
}
void
InitializationSequence::AddUserConversionStep(FunctionDecl *Function,
DeclAccessPair FoundDecl,
QualType T,
bool HadMultipleCandidates) {
Step S;
S.Kind = SK_UserConversion;
S.Type = T;
S.Function.HadMultipleCandidates = HadMultipleCandidates;
S.Function.Function = Function;
S.Function.FoundDecl = FoundDecl;
Steps.push_back(S);
}
void InitializationSequence::AddQualificationConversionStep(QualType Ty,
ExprValueKind VK) {
Step S;
S.Kind = SK_QualificationConversionRValue; // work around a gcc warning
switch (VK) {
case VK_RValue:
S.Kind = SK_QualificationConversionRValue;
break;
case VK_XValue:
S.Kind = SK_QualificationConversionXValue;
break;
case VK_LValue:
S.Kind = SK_QualificationConversionLValue;
break;
}
S.Type = Ty;
Steps.push_back(S);
}
void InitializationSequence::AddAtomicConversionStep(QualType Ty) {
Step S;
S.Kind = SK_AtomicConversion;
S.Type = Ty;
Steps.push_back(S);
}
void InitializationSequence::AddLValueToRValueStep(QualType Ty) {
assert(!Ty.hasQualifiers() && "rvalues may not have qualifiers");
Step S;
S.Kind = SK_LValueToRValue;
S.Type = Ty;
Steps.push_back(S);
}
void InitializationSequence::AddConversionSequenceStep(
const ImplicitConversionSequence &ICS, QualType T,
bool TopLevelOfInitList) {
Step S;
S.Kind = TopLevelOfInitList ? SK_ConversionSequenceNoNarrowing
: SK_ConversionSequence;
S.Type = T;
S.ICS = new ImplicitConversionSequence(ICS);
Steps.push_back(S);
}
void InitializationSequence::AddListInitializationStep(QualType T) {
Step S;
S.Kind = SK_ListInitialization;
S.Type = T;
Steps.push_back(S);
}
void
InitializationSequence
::AddConstructorInitializationStep(CXXConstructorDecl *Constructor,
AccessSpecifier Access,
QualType T,
bool HadMultipleCandidates,
bool FromInitList, bool AsInitList) {
Step S;
S.Kind = FromInitList ? AsInitList ? SK_StdInitializerListConstructorCall
: SK_ConstructorInitializationFromList
: SK_ConstructorInitialization;
S.Type = T;
S.Function.HadMultipleCandidates = HadMultipleCandidates;
S.Function.Function = Constructor;
S.Function.FoundDecl = DeclAccessPair::make(Constructor, Access);
Steps.push_back(S);
}
void InitializationSequence::AddZeroInitializationStep(QualType T) {
Step S;
S.Kind = SK_ZeroInitialization;
S.Type = T;
Steps.push_back(S);
}
void InitializationSequence::AddCAssignmentStep(QualType T) {
Step S;
S.Kind = SK_CAssignment;
S.Type = T;
Steps.push_back(S);
}
void InitializationSequence::AddStringInitStep(QualType T) {
Step S;
S.Kind = SK_StringInit;
S.Type = T;
Steps.push_back(S);
}
void InitializationSequence::AddObjCObjectConversionStep(QualType T) {
Step S;
S.Kind = SK_ObjCObjectConversion;
S.Type = T;
Steps.push_back(S);
}
void InitializationSequence::AddArrayInitStep(QualType T) {
Step S;
S.Kind = SK_ArrayInit;
S.Type = T;
Steps.push_back(S);
}
void InitializationSequence::AddParenthesizedArrayInitStep(QualType T) {
Step S;
S.Kind = SK_ParenthesizedArrayInit;
S.Type = T;
Steps.push_back(S);
}
void InitializationSequence::AddPassByIndirectCopyRestoreStep(QualType type,
bool shouldCopy) {
Step s;
s.Kind = (shouldCopy ? SK_PassByIndirectCopyRestore
: SK_PassByIndirectRestore);
s.Type = type;
Steps.push_back(s);
}
void InitializationSequence::AddProduceObjCObjectStep(QualType T) {
Step S;
S.Kind = SK_ProduceObjCObject;
S.Type = T;
Steps.push_back(S);
}
void InitializationSequence::AddStdInitializerListConstructionStep(QualType T) {
Step S;
S.Kind = SK_StdInitializerList;
S.Type = T;
Steps.push_back(S);
}
void InitializationSequence::AddOCLSamplerInitStep(QualType T) {
Step S;
S.Kind = SK_OCLSamplerInit;
S.Type = T;
Steps.push_back(S);
}
void InitializationSequence::AddOCLZeroEventStep(QualType T) {
Step S;
S.Kind = SK_OCLZeroEvent;
S.Type = T;
Steps.push_back(S);
}
void InitializationSequence::RewrapReferenceInitList(QualType T,
InitListExpr *Syntactic) {
assert(Syntactic->getNumInits() == 1 &&
"Can only rewrap trivial init lists.");
Step S;
S.Kind = SK_UnwrapInitList;
S.Type = Syntactic->getInit(0)->getType();
Steps.insert(Steps.begin(), S);
S.Kind = SK_RewrapInitList;
S.Type = T;
S.WrappingSyntacticList = Syntactic;
Steps.push_back(S);
}
void InitializationSequence::SetOverloadFailure(FailureKind Failure,
OverloadingResult Result) {
setSequenceKind(FailedSequence);
this->Failure = Failure;
this->FailedOverloadResult = Result;
}
//===----------------------------------------------------------------------===//
// Attempt initialization
//===----------------------------------------------------------------------===//
static void MaybeProduceObjCObject(Sema &S,
InitializationSequence &Sequence,
const InitializedEntity &Entity) {
if (!S.getLangOpts().ObjCAutoRefCount) return;
/// When initializing a parameter, produce the value if it's marked
/// __attribute__((ns_consumed)).
if (Entity.isParameterKind()) {
if (!Entity.isParameterConsumed())
return;
assert(Entity.getType()->isObjCRetainableType() &&
"consuming an object of unretainable type?");
Sequence.AddProduceObjCObjectStep(Entity.getType());
/// When initializing a return value, if the return type is a
/// retainable type, then returns need to immediately retain the
/// object. If an autorelease is required, it will be done at the
/// last instant.
} else if (Entity.getKind() == InitializedEntity::EK_Result) {
if (!Entity.getType()->isObjCRetainableType())
return;
Sequence.AddProduceObjCObjectStep(Entity.getType());
}
}
static void TryListInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
InitListExpr *InitList,
InitializationSequence &Sequence);
/// \brief When initializing from init list via constructor, handle
/// initialization of an object of type std::initializer_list<T>.
///
/// \return true if we have handled initialization of an object of type
/// std::initializer_list<T>, false otherwise.
static bool TryInitializerListConstruction(Sema &S,
InitListExpr *List,
QualType DestType,
InitializationSequence &Sequence) {
QualType E;
if (!S.isStdInitializerList(DestType, &E))
return false;
if (S.RequireCompleteType(List->getExprLoc(), E, 0)) {
Sequence.setIncompleteTypeFailure(E);
return true;
}
// Try initializing a temporary array from the init list.
QualType ArrayType = S.Context.getConstantArrayType(
E.withConst(), llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
List->getNumInits()),
clang::ArrayType::Normal, 0);
InitializedEntity HiddenArray =
InitializedEntity::InitializeTemporary(ArrayType);
InitializationKind Kind =
InitializationKind::CreateDirectList(List->getExprLoc());
TryListInitialization(S, HiddenArray, Kind, List, Sequence);
if (Sequence)
Sequence.AddStdInitializerListConstructionStep(DestType);
return true;
}
static OverloadingResult
ResolveConstructorOverload(Sema &S, SourceLocation DeclLoc,
MultiExprArg Args,
OverloadCandidateSet &CandidateSet,
ArrayRef<NamedDecl *> Ctors,
OverloadCandidateSet::iterator &Best,
bool CopyInitializing, bool AllowExplicit,
bool OnlyListConstructors, bool InitListSyntax) {
CandidateSet.clear();
for (ArrayRef<NamedDecl *>::iterator
Con = Ctors.begin(), ConEnd = Ctors.end(); Con != ConEnd; ++Con) {
NamedDecl *D = *Con;
DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess());
bool SuppressUserConversions = false;
// Find the constructor (which may be a template).
CXXConstructorDecl *Constructor = nullptr;
FunctionTemplateDecl *ConstructorTmpl = dyn_cast<FunctionTemplateDecl>(D);
if (ConstructorTmpl)
Constructor = cast<CXXConstructorDecl>(
ConstructorTmpl->getTemplatedDecl());
else {
Constructor = cast<CXXConstructorDecl>(D);
// C++11 [over.best.ics]p4:
// However, when considering the argument of a constructor or
// user-defined conversion function that is a candidate:
// -- by 13.3.1.3 when invoked for the copying/moving of a temporary
// in the second step of a class copy-initialization,
// -- by 13.3.1.7 when passing the initializer list as a single
// argument or when the initializer list has exactly one elementand
// a conversion to some class X or reference to (possibly
// cv-qualified) X is considered for the first parameter of a
// constructor of X, or
// -- by 13.3.1.4, 13.3.1.5, or 13.3.1.6 in all cases,
// only standard conversion sequences and ellipsis conversion sequences
// are considered.
if ((CopyInitializing || (InitListSyntax && Args.size() == 1)) &&
Constructor->isCopyOrMoveConstructor())
SuppressUserConversions = true;
}
if (!Constructor->isInvalidDecl() &&
(AllowExplicit || !Constructor->isExplicit()) &&
(!OnlyListConstructors || S.isInitListConstructor(Constructor))) {
if (ConstructorTmpl)
S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl,
/*ExplicitArgs*/ nullptr, Args,
CandidateSet, SuppressUserConversions);
else {
// C++ [over.match.copy]p1:
// - When initializing a temporary to be bound to the first parameter
// of a constructor that takes a reference to possibly cv-qualified
// T as its first argument, called with a single argument in the
// context of direct-initialization, explicit conversion functions
// are also considered.
bool AllowExplicitConv = AllowExplicit && !CopyInitializing &&
Args.size() == 1 &&
Constructor->isCopyOrMoveConstructor();
S.AddOverloadCandidate(Constructor, FoundDecl, Args, CandidateSet,
SuppressUserConversions,
/*PartialOverloading=*/false,
/*AllowExplicit=*/AllowExplicitConv);
}
}
}
// Perform overload resolution and return the result.
return CandidateSet.BestViableFunction(S, DeclLoc, Best);
}
/// \brief Attempt initialization by constructor (C++ [dcl.init]), which
/// enumerates the constructors of the initialized entity and performs overload
/// resolution to select the best.
/// If InitListSyntax is true, this is list-initialization of a non-aggregate
/// class type.
static void TryConstructorInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
MultiExprArg Args, QualType DestType,
InitializationSequence &Sequence,
bool InitListSyntax = false) {
assert((!InitListSyntax || (Args.size() == 1 && isa<InitListExpr>(Args[0]))) &&
"InitListSyntax must come with a single initializer list argument.");
// The type we're constructing needs to be complete.
if (S.RequireCompleteType(Kind.getLocation(), DestType, 0)) {
Sequence.setIncompleteTypeFailure(DestType);
return;
}
const RecordType *DestRecordType = DestType->getAs<RecordType>();
assert(DestRecordType && "Constructor initialization requires record type");
CXXRecordDecl *DestRecordDecl
= cast<CXXRecordDecl>(DestRecordType->getDecl());
// Build the candidate set directly in the initialization sequence
// structure, so that it will persist if we fail.
OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
// Determine whether we are allowed to call explicit constructors or
// explicit conversion operators.
bool AllowExplicit = Kind.AllowExplicit() || InitListSyntax;
bool CopyInitialization = Kind.getKind() == InitializationKind::IK_Copy;
// - Otherwise, if T is a class type, constructors are considered. The
// applicable constructors are enumerated, and the best one is chosen
// through overload resolution.
DeclContext::lookup_result R = S.LookupConstructors(DestRecordDecl);
// The container holding the constructors can under certain conditions
// be changed while iterating (e.g. because of deserialization).
// To be safe we copy the lookup results to a new container.
SmallVector<NamedDecl*, 16> Ctors(R.begin(), R.end());
OverloadingResult Result = OR_No_Viable_Function;
OverloadCandidateSet::iterator Best;
bool AsInitializerList = false;
// C++11 [over.match.list]p1:
// When objects of non-aggregate type T are list-initialized, overload
// resolution selects the constructor in two phases:
// - Initially, the candidate functions are the initializer-list
// constructors of the class T and the argument list consists of the
// initializer list as a single argument.
if (InitListSyntax) {
InitListExpr *ILE = cast<InitListExpr>(Args[0]);
AsInitializerList = true;
// If the initializer list has no elements and T has a default constructor,
// the first phase is omitted.
if (ILE->getNumInits() != 0 || !DestRecordDecl->hasDefaultConstructor())
Result = ResolveConstructorOverload(S, Kind.getLocation(), Args,
CandidateSet, Ctors, Best,
CopyInitialization, AllowExplicit,
/*OnlyListConstructor=*/true,
InitListSyntax);
// Time to unwrap the init list.
Args = MultiExprArg(ILE->getInits(), ILE->getNumInits());
}
// C++11 [over.match.list]p1:
// - If no viable initializer-list constructor is found, overload resolution
// is performed again, where the candidate functions are all the
// constructors of the class T and the argument list consists of the
// elements of the initializer list.
if (Result == OR_No_Viable_Function) {
AsInitializerList = false;
Result = ResolveConstructorOverload(S, Kind.getLocation(), Args,
CandidateSet, Ctors, Best,
CopyInitialization, AllowExplicit,
/*OnlyListConstructors=*/false,
InitListSyntax);
}
if (Result) {
Sequence.SetOverloadFailure(InitListSyntax ?
InitializationSequence::FK_ListConstructorOverloadFailed :
InitializationSequence::FK_ConstructorOverloadFailed,
Result);
return;
}
// C++11 [dcl.init]p6:
// If a program calls for the default initialization of an object
// of a const-qualified type T, T shall be a class type with a
// user-provided default constructor.
if (Kind.getKind() == InitializationKind::IK_Default &&
Entity.getType().isConstQualified() &&
!cast<CXXConstructorDecl>(Best->Function)->isUserProvided()) {
Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst);
return;
}
// C++11 [over.match.list]p1:
// In copy-list-initialization, if an explicit constructor is chosen, the
// initializer is ill-formed.
CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
if (InitListSyntax && !Kind.AllowExplicit() && CtorDecl->isExplicit()) {
Sequence.SetFailed(InitializationSequence::FK_ExplicitConstructor);
return;
}
// Add the constructor initialization step. Any cv-qualification conversion is
// subsumed by the initialization.
bool HadMultipleCandidates = (CandidateSet.size() > 1);
Sequence.AddConstructorInitializationStep(CtorDecl,
Best->FoundDecl.getAccess(),
DestType, HadMultipleCandidates,
InitListSyntax, AsInitializerList);
}
static bool
ResolveOverloadedFunctionForReferenceBinding(Sema &S,
Expr *Initializer,
QualType &SourceType,
QualType &UnqualifiedSourceType,
QualType UnqualifiedTargetType,
InitializationSequence &Sequence) {
if (S.Context.getCanonicalType(UnqualifiedSourceType) ==
S.Context.OverloadTy) {
DeclAccessPair Found;
bool HadMultipleCandidates = false;
if (FunctionDecl *Fn
= S.ResolveAddressOfOverloadedFunction(Initializer,
UnqualifiedTargetType,
false, Found,
&HadMultipleCandidates)) {
Sequence.AddAddressOverloadResolutionStep(Fn, Found,
HadMultipleCandidates);
SourceType = Fn->getType();
UnqualifiedSourceType = SourceType.getUnqualifiedType();
} else if (!UnqualifiedTargetType->isRecordType()) {
Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
return true;
}
}
return false;
}
static void TryReferenceInitializationCore(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Expr *Initializer,
QualType cv1T1, QualType T1,
Qualifiers T1Quals,
QualType cv2T2, QualType T2,
Qualifiers T2Quals,
InitializationSequence &Sequence);
static void TryValueInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
InitializationSequence &Sequence,
InitListExpr *InitList = nullptr);
/// \brief Attempt list initialization of a reference.
static void TryReferenceListInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
InitListExpr *InitList,
InitializationSequence &Sequence) {
// First, catch C++03 where this isn't possible.
if (!S.getLangOpts().CPlusPlus11) {
Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList);
return;
}
QualType DestType = Entity.getType();
QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType();
Qualifiers T1Quals;
QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals);
// Reference initialization via an initializer list works thus:
// If the initializer list consists of a single element that is
// reference-related to the referenced type, bind directly to that element
// (possibly creating temporaries).
// Otherwise, initialize a temporary with the initializer list and
// bind to that.
if (InitList->getNumInits() == 1) {
Expr *Initializer = InitList->getInit(0);
QualType cv2T2 = Initializer->getType();
Qualifiers T2Quals;
QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals);
// If this fails, creating a temporary wouldn't work either.
if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2,
T1, Sequence))
return;
SourceLocation DeclLoc = Initializer->getLocStart();
bool dummy1, dummy2, dummy3;
Sema::ReferenceCompareResult RefRelationship
= S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, dummy1,
dummy2, dummy3);
if (RefRelationship >= Sema::Ref_Related) {
// Try to bind the reference here.
TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1,
T1Quals, cv2T2, T2, T2Quals, Sequence);
if (Sequence)
Sequence.RewrapReferenceInitList(cv1T1, InitList);
return;
}
// Update the initializer if we've resolved an overloaded function.
if (Sequence.step_begin() != Sequence.step_end())
Sequence.RewrapReferenceInitList(cv1T1, InitList);
}
// Not reference-related. Create a temporary and bind to that.
InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(cv1T1);
TryListInitialization(S, TempEntity, Kind, InitList, Sequence);
if (Sequence) {
if (DestType->isRValueReferenceType() ||
(T1Quals.hasConst() && !T1Quals.hasVolatile()))
Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true);
else
Sequence.SetFailed(
InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary);
}
}
/// \brief Attempt list initialization (C++0x [dcl.init.list])
static void TryListInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
InitListExpr *InitList,
InitializationSequence &Sequence) {
QualType DestType = Entity.getType();
// C++ doesn't allow scalar initialization with more than one argument.
// But C99 complex numbers are scalars and it makes sense there.
if (S.getLangOpts().CPlusPlus && DestType->isScalarType() &&
!DestType->isAnyComplexType() && InitList->getNumInits() > 1) {
Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForScalar);
return;
}
if (DestType->isReferenceType()) {
TryReferenceListInitialization(S, Entity, Kind, InitList, Sequence);
return;
}
if (DestType->isRecordType()) {
if (S.RequireCompleteType(InitList->getLocStart(), DestType, 0)) {
Sequence.setIncompleteTypeFailure(DestType);
return;
}
// C++11 [dcl.init.list]p3:
// - If T is an aggregate, aggregate initialization is performed.
if (!DestType->isAggregateType()) {
if (S.getLangOpts().CPlusPlus11) {
// - Otherwise, if the initializer list has no elements and T is a
// class type with a default constructor, the object is
// value-initialized.
if (InitList->getNumInits() == 0) {
CXXRecordDecl *RD = DestType->getAsCXXRecordDecl();
if (RD->hasDefaultConstructor()) {
TryValueInitialization(S, Entity, Kind, Sequence, InitList);
return;
}
}
// - Otherwise, if T is a specialization of std::initializer_list<E>,
// an initializer_list object constructed [...]
if (TryInitializerListConstruction(S, InitList, DestType, Sequence))
return;
// - Otherwise, if T is a class type, constructors are considered.
Expr *InitListAsExpr = InitList;
TryConstructorInitialization(S, Entity, Kind, InitListAsExpr, DestType,
Sequence, /*InitListSyntax*/true);
} else
Sequence.SetFailed(
InitializationSequence::FK_InitListBadDestinationType);
return;
}
}
if (S.getLangOpts().CPlusPlus && !DestType->isAggregateType() &&
InitList->getNumInits() == 1 &&
InitList->getInit(0)->getType()->isRecordType()) {
// - Otherwise, if the initializer list has a single element of type E
// [...references are handled above...], the object or reference is
// initialized from that element; if a narrowing conversion is required
// to convert the element to T, the program is ill-formed.
//
// Per core-24034, this is direct-initialization if we were performing
// direct-list-initialization and copy-initialization otherwise.
// We can't use InitListChecker for this, because it always performs
// copy-initialization. This only matters if we might use an 'explicit'
// conversion operator, so we only need to handle the cases where the source
// is of record type.
InitializationKind SubKind =
Kind.getKind() == InitializationKind::IK_DirectList
? InitializationKind::CreateDirect(Kind.getLocation(),
InitList->getLBraceLoc(),
InitList->getRBraceLoc())
: Kind;
Expr *SubInit[1] = { InitList->getInit(0) };
Sequence.InitializeFrom(S, Entity, SubKind, SubInit,
/*TopLevelOfInitList*/true);
if (Sequence)
Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
return;
}
InitListChecker CheckInitList(S, Entity, InitList,
DestType, /*VerifyOnly=*/true);
if (CheckInitList.HadError()) {
Sequence.SetFailed(InitializationSequence::FK_ListInitializationFailed);
return;
}
// Add the list initialization step with the built init list.
Sequence.AddListInitializationStep(DestType);
}
/// \brief Try a reference initialization that involves calling a conversion
/// function.
static OverloadingResult TryRefInitWithConversionFunction(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Expr *Initializer,
bool AllowRValues,
InitializationSequence &Sequence) {
QualType DestType = Entity.getType();
QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType();
QualType T1 = cv1T1.getUnqualifiedType();
QualType cv2T2 = Initializer->getType();
QualType T2 = cv2T2.getUnqualifiedType();
bool DerivedToBase;
bool ObjCConversion;
bool ObjCLifetimeConversion;
assert(!S.CompareReferenceRelationship(Initializer->getLocStart(),
T1, T2, DerivedToBase,
ObjCConversion,
ObjCLifetimeConversion) &&
"Must have incompatible references when binding via conversion");
(void)DerivedToBase;
(void)ObjCConversion;
(void)ObjCLifetimeConversion;
// Build the candidate set directly in the initialization sequence
// structure, so that it will persist if we fail.
OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
CandidateSet.clear();
// Determine whether we are allowed to call explicit constructors or
// explicit conversion operators.
bool AllowExplicit = Kind.AllowExplicit();
bool AllowExplicitConvs = Kind.allowExplicitConversionFunctionsInRefBinding();
const RecordType *T1RecordType = nullptr;
if (AllowRValues && (T1RecordType = T1->getAs<RecordType>()) &&
!S.RequireCompleteType(Kind.getLocation(), T1, 0)) {
// The type we're converting to is a class type. Enumerate its constructors
// to see if there is a suitable conversion.
CXXRecordDecl *T1RecordDecl = cast<CXXRecordDecl>(T1RecordType->getDecl());
DeclContext::lookup_result R = S.LookupConstructors(T1RecordDecl);
// The container holding the constructors can under certain conditions
// be changed while iterating (e.g. because of deserialization).
// To be safe we copy the lookup results to a new container.
SmallVector<NamedDecl*, 16> Ctors(R.begin(), R.end());
for (SmallVectorImpl<NamedDecl *>::iterator
CI = Ctors.begin(), CE = Ctors.end(); CI != CE; ++CI) {
NamedDecl *D = *CI;
DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess());
// Find the constructor (which may be a template).
CXXConstructorDecl *Constructor = nullptr;
FunctionTemplateDecl *ConstructorTmpl = dyn_cast<FunctionTemplateDecl>(D);
if (ConstructorTmpl)
Constructor = cast<CXXConstructorDecl>(
ConstructorTmpl->getTemplatedDecl());
else
Constructor = cast<CXXConstructorDecl>(D);
if (!Constructor->isInvalidDecl() &&
Constructor->isConvertingConstructor(AllowExplicit)) {
if (ConstructorTmpl)
S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl,
/*ExplicitArgs*/ nullptr,
Initializer, CandidateSet,
/*SuppressUserConversions=*/true);
else
S.AddOverloadCandidate(Constructor, FoundDecl,
Initializer, CandidateSet,
/*SuppressUserConversions=*/true);
}
}
}
if (T1RecordType && T1RecordType->getDecl()->isInvalidDecl())
return OR_No_Viable_Function;
const RecordType *T2RecordType = nullptr;
if ((T2RecordType = T2->getAs<RecordType>()) &&
!S.RequireCompleteType(Kind.getLocation(), T2, 0)) {
// The type we're converting from is a class type, enumerate its conversion
// functions.
CXXRecordDecl *T2RecordDecl = cast<CXXRecordDecl>(T2RecordType->getDecl());
std::pair<CXXRecordDecl::conversion_iterator,
CXXRecordDecl::conversion_iterator>
Conversions = T2RecordDecl->getVisibleConversionFunctions();
for (CXXRecordDecl::conversion_iterator
I = Conversions.first, E = Conversions.second; I != E; ++I) {
NamedDecl *D = *I;
CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
CXXConversionDecl *Conv;
if (ConvTemplate)
Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
else
Conv = cast<CXXConversionDecl>(D);
// If the conversion function doesn't return a reference type,
// it can't be considered for this conversion unless we're allowed to
// consider rvalues.
// FIXME: Do we need to make sure that we only consider conversion
// candidates with reference-compatible results? That might be needed to
// break recursion.
if ((AllowExplicitConvs || !Conv->isExplicit()) &&
(AllowRValues || Conv->getConversionType()->isLValueReferenceType())){
if (ConvTemplate)
S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(),
ActingDC, Initializer,
DestType, CandidateSet,
/*AllowObjCConversionOnExplicit=*/
false);
else
S.AddConversionCandidate(Conv, I.getPair(), ActingDC,
Initializer, DestType, CandidateSet,
/*AllowObjCConversionOnExplicit=*/false);
}
}
}
if (T2RecordType && T2RecordType->getDecl()->isInvalidDecl())
return OR_No_Viable_Function;
SourceLocation DeclLoc = Initializer->getLocStart();
// Perform overload resolution. If it fails, return the failed result.
OverloadCandidateSet::iterator Best;
if (OverloadingResult Result
= CandidateSet.BestViableFunction(S, DeclLoc, Best, true))
return Result;
FunctionDecl *Function = Best->Function;
// This is the overload that will be used for this initialization step if we
// use this initialization. Mark it as referenced.
Function->setReferenced();
// Compute the returned type of the conversion.
if (isa<CXXConversionDecl>(Function))
T2 = Function->getReturnType();
else
T2 = cv1T1;
// Add the user-defined conversion step.
bool HadMultipleCandidates = (CandidateSet.size() > 1);
Sequence.AddUserConversionStep(Function, Best->FoundDecl,
T2.getNonLValueExprType(S.Context),
HadMultipleCandidates);
// Determine whether we need to perform derived-to-base or
// cv-qualification adjustments.
ExprValueKind VK = VK_RValue;
if (T2->isLValueReferenceType())
VK = VK_LValue;
else if (const RValueReferenceType *RRef = T2->getAs<RValueReferenceType>())
VK = RRef->getPointeeType()->isFunctionType() ? VK_LValue : VK_XValue;
bool NewDerivedToBase = false;
bool NewObjCConversion = false;
bool NewObjCLifetimeConversion = false;
Sema::ReferenceCompareResult NewRefRelationship
= S.CompareReferenceRelationship(DeclLoc, T1,
T2.getNonLValueExprType(S.Context),
NewDerivedToBase, NewObjCConversion,
NewObjCLifetimeConversion);
if (NewRefRelationship == Sema::Ref_Incompatible) {
// If the type we've converted to is not reference-related to the
// type we're looking for, then there is another conversion step
// we need to perform to produce a temporary of the right type
// that we'll be binding to.
ImplicitConversionSequence ICS;
ICS.setStandard();
ICS.Standard = Best->FinalConversion;
T2 = ICS.Standard.getToType(2);
Sequence.AddConversionSequenceStep(ICS, T2);
} else if (NewDerivedToBase)
Sequence.AddDerivedToBaseCastStep(
S.Context.getQualifiedType(T1,
T2.getNonReferenceType().getQualifiers()),
VK);
else if (NewObjCConversion)
Sequence.AddObjCObjectConversionStep(
S.Context.getQualifiedType(T1,
T2.getNonReferenceType().getQualifiers()));
if (cv1T1.getQualifiers() != T2.getNonReferenceType().getQualifiers())
Sequence.AddQualificationConversionStep(cv1T1, VK);
Sequence.AddReferenceBindingStep(cv1T1, !T2->isReferenceType());
return OR_Success;
}
static void CheckCXX98CompatAccessibleCopy(Sema &S,
const InitializedEntity &Entity,
Expr *CurInitExpr);
/// \brief Attempt reference initialization (C++0x [dcl.init.ref])
static void TryReferenceInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Expr *Initializer,
InitializationSequence &Sequence) {
QualType DestType = Entity.getType();
QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType();
Qualifiers T1Quals;
QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals);
QualType cv2T2 = Initializer->getType();
Qualifiers T2Quals;
QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals);
// If the initializer is the address of an overloaded function, try
// to resolve the overloaded function. If all goes well, T2 is the
// type of the resulting function.
if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2,
T1, Sequence))
return;
// Delegate everything else to a subfunction.
TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1,
T1Quals, cv2T2, T2, T2Quals, Sequence);
}
/// Converts the target of reference initialization so that it has the
/// appropriate qualifiers and value kind.
///
/// In this case, 'x' is an 'int' lvalue, but it needs to be 'const int'.
/// \code
/// int x;
/// const int &r = x;
/// \endcode
///
/// In this case the reference is binding to a bitfield lvalue, which isn't
/// valid. Perform a load to create a lifetime-extended temporary instead.
/// \code
/// const int &r = someStruct.bitfield;
/// \endcode
static ExprValueKind
convertQualifiersAndValueKindIfNecessary(Sema &S,
InitializationSequence &Sequence,
Expr *Initializer,
QualType cv1T1,
Qualifiers T1Quals,
Qualifiers T2Quals,
bool IsLValueRef) {
bool IsNonAddressableType = Initializer->refersToBitField() ||
Initializer->refersToVectorElement();
if (IsNonAddressableType) {
// C++11 [dcl.init.ref]p5: [...] Otherwise, the reference shall be an
// lvalue reference to a non-volatile const type, or the reference shall be
// an rvalue reference.
//
// If not, we can't make a temporary and bind to that. Give up and allow the
// error to be diagnosed later.
if (IsLValueRef && (!T1Quals.hasConst() || T1Quals.hasVolatile())) {
assert(Initializer->isGLValue());
return Initializer->getValueKind();
}
// Force a load so we can materialize a temporary.
Sequence.AddLValueToRValueStep(cv1T1.getUnqualifiedType());
return VK_RValue;
}
if (T1Quals != T2Quals) {
Sequence.AddQualificationConversionStep(cv1T1,
Initializer->getValueKind());
}
return Initializer->getValueKind();
}
/// \brief Reference initialization without resolving overloaded functions.
static void TryReferenceInitializationCore(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Expr *Initializer,
QualType cv1T1, QualType T1,
Qualifiers T1Quals,
QualType cv2T2, QualType T2,
Qualifiers T2Quals,
InitializationSequence &Sequence) {
QualType DestType = Entity.getType();
SourceLocation DeclLoc = Initializer->getLocStart();
// Compute some basic properties of the types and the initializer.
bool isLValueRef = DestType->isLValueReferenceType();
bool isRValueRef = !isLValueRef;
bool DerivedToBase = false;
bool ObjCConversion = false;
bool ObjCLifetimeConversion = false;
Expr::Classification InitCategory = Initializer->Classify(S.Context);
Sema::ReferenceCompareResult RefRelationship
= S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, DerivedToBase,
ObjCConversion, ObjCLifetimeConversion);
// C++0x [dcl.init.ref]p5:
// A reference to type "cv1 T1" is initialized by an expression of type
// "cv2 T2" as follows:
//
// - If the reference is an lvalue reference and the initializer
// expression
// Note the analogous bullet points for rvalue refs to functions. Because
// there are no function rvalues in C++, rvalue refs to functions are treated
// like lvalue refs.
OverloadingResult ConvOvlResult = OR_Success;
bool T1Function = T1->isFunctionType();
if (isLValueRef || T1Function) {
if (InitCategory.isLValue() &&
(RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification ||
(Kind.isCStyleOrFunctionalCast() &&
RefRelationship == Sema::Ref_Related))) {
// - is an lvalue (but is not a bit-field), and "cv1 T1" is
// reference-compatible with "cv2 T2," or
//
// Per C++ [over.best.ics]p2, we don't diagnose whether the lvalue is a
// bit-field when we're determining whether the reference initialization
// can occur. However, we do pay attention to whether it is a bit-field
// to decide whether we're actually binding to a temporary created from
// the bit-field.
if (DerivedToBase)
Sequence.AddDerivedToBaseCastStep(
S.Context.getQualifiedType(T1, T2Quals),
VK_LValue);
else if (ObjCConversion)
Sequence.AddObjCObjectConversionStep(
S.Context.getQualifiedType(T1, T2Quals));
ExprValueKind ValueKind =
convertQualifiersAndValueKindIfNecessary(S, Sequence, Initializer,
cv1T1, T1Quals, T2Quals,
isLValueRef);
Sequence.AddReferenceBindingStep(cv1T1, ValueKind == VK_RValue);
return;
}
// - has a class type (i.e., T2 is a class type), where T1 is not
// reference-related to T2, and can be implicitly converted to an
// lvalue of type "cv3 T3," where "cv1 T1" is reference-compatible
// with "cv3 T3" (this conversion is selected by enumerating the
// applicable conversion functions (13.3.1.6) and choosing the best
// one through overload resolution (13.3)),
// If we have an rvalue ref to function type here, the rhs must be
// an rvalue. DR1287 removed the "implicitly" here.
if (RefRelationship == Sema::Ref_Incompatible && T2->isRecordType() &&
(isLValueRef || InitCategory.isRValue())) {
ConvOvlResult = TryRefInitWithConversionFunction(
S, Entity, Kind, Initializer, /*AllowRValues*/isRValueRef, Sequence);
if (ConvOvlResult == OR_Success)
return;
if (ConvOvlResult != OR_No_Viable_Function)
Sequence.SetOverloadFailure(
InitializationSequence::FK_ReferenceInitOverloadFailed,
ConvOvlResult);
}
}
// - Otherwise, the reference shall be an lvalue reference to a
// non-volatile const type (i.e., cv1 shall be const), or the reference
// shall be an rvalue reference.
if (isLValueRef && !(T1Quals.hasConst() && !T1Quals.hasVolatile())) {
if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy)
Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
else if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
Sequence.SetOverloadFailure(
InitializationSequence::FK_ReferenceInitOverloadFailed,
ConvOvlResult);
else
Sequence.SetFailed(InitCategory.isLValue()
? (RefRelationship == Sema::Ref_Related
? InitializationSequence::FK_ReferenceInitDropsQualifiers
: InitializationSequence::FK_NonConstLValueReferenceBindingToUnrelated)
: InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary);
return;
}
// - If the initializer expression
// - is an xvalue, class prvalue, array prvalue, or function lvalue and
// "cv1 T1" is reference-compatible with "cv2 T2"
// Note: functions are handled below.
if (!T1Function &&
(RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification ||
(Kind.isCStyleOrFunctionalCast() &&
RefRelationship == Sema::Ref_Related)) &&
(InitCategory.isXValue() ||
(InitCategory.isPRValue() && T2->isRecordType()) ||
(InitCategory.isPRValue() && T2->isArrayType()))) {
ExprValueKind ValueKind = InitCategory.isXValue()? VK_XValue : VK_RValue;
if (InitCategory.isPRValue() && T2->isRecordType()) {
// The corresponding bullet in C++03 [dcl.init.ref]p5 gives the
// compiler the freedom to perform a copy here or bind to the
// object, while C++0x requires that we bind directly to the
// object. Hence, we always bind to the object without making an
// extra copy. However, in C++03 requires that we check for the
// presence of a suitable copy constructor:
//
// The constructor that would be used to make the copy shall
// be callable whether or not the copy is actually done.
if (!S.getLangOpts().CPlusPlus11 && !S.getLangOpts().MicrosoftExt)
Sequence.AddExtraneousCopyToTemporary(cv2T2);
else if (S.getLangOpts().CPlusPlus11)
CheckCXX98CompatAccessibleCopy(S, Entity, Initializer);
}
if (DerivedToBase)
Sequence.AddDerivedToBaseCastStep(S.Context.getQualifiedType(T1, T2Quals),
ValueKind);
else if (ObjCConversion)
Sequence.AddObjCObjectConversionStep(
S.Context.getQualifiedType(T1, T2Quals));
ValueKind = convertQualifiersAndValueKindIfNecessary(S, Sequence,
Initializer, cv1T1,
T1Quals, T2Quals,
isLValueRef);
Sequence.AddReferenceBindingStep(cv1T1, ValueKind == VK_RValue);
return;
}
// - has a class type (i.e., T2 is a class type), where T1 is not
// reference-related to T2, and can be implicitly converted to an
// xvalue, class prvalue, or function lvalue of type "cv3 T3",
// where "cv1 T1" is reference-compatible with "cv3 T3",
//
// DR1287 removes the "implicitly" here.
if (T2->isRecordType()) {
if (RefRelationship == Sema::Ref_Incompatible) {
ConvOvlResult = TryRefInitWithConversionFunction(
S, Entity, Kind, Initializer, /*AllowRValues*/true, Sequence);
if (ConvOvlResult)
Sequence.SetOverloadFailure(
InitializationSequence::FK_ReferenceInitOverloadFailed,
ConvOvlResult);
return;
}
if ((RefRelationship == Sema::Ref_Compatible ||
RefRelationship == Sema::Ref_Compatible_With_Added_Qualification) &&
isRValueRef && InitCategory.isLValue()) {
Sequence.SetFailed(
InitializationSequence::FK_RValueReferenceBindingToLValue);
return;
}
Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
return;
}
// - Otherwise, a temporary of type "cv1 T1" is created and initialized
// from the initializer expression using the rules for a non-reference
// copy-initialization (8.5). The reference is then bound to the
// temporary. [...]
InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(cv1T1);
// FIXME: Why do we use an implicit conversion here rather than trying
// copy-initialization?
ImplicitConversionSequence ICS
= S.TryImplicitConversion(Initializer, TempEntity.getType(),
/*SuppressUserConversions=*/false,
/*AllowExplicit=*/false,
/*FIXME:InOverloadResolution=*/false,
/*CStyle=*/Kind.isCStyleOrFunctionalCast(),
/*AllowObjCWritebackConversion=*/false);
if (ICS.isBad()) {
// FIXME: Use the conversion function set stored in ICS to turn
// this into an overloading ambiguity diagnostic. However, we need
// to keep that set as an OverloadCandidateSet rather than as some
// other kind of set.
if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
Sequence.SetOverloadFailure(
InitializationSequence::FK_ReferenceInitOverloadFailed,
ConvOvlResult);
else if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy)
Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
else
Sequence.SetFailed(InitializationSequence::FK_ReferenceInitFailed);
return;
} else {
Sequence.AddConversionSequenceStep(ICS, TempEntity.getType());
}
// [...] If T1 is reference-related to T2, cv1 must be the
// same cv-qualification as, or greater cv-qualification
// than, cv2; otherwise, the program is ill-formed.
unsigned T1CVRQuals = T1Quals.getCVRQualifiers();
unsigned T2CVRQuals = T2Quals.getCVRQualifiers();
if (RefRelationship == Sema::Ref_Related &&
(T1CVRQuals | T2CVRQuals) != T1CVRQuals) {
Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
return;
}
// [...] If T1 is reference-related to T2 and the reference is an rvalue
// reference, the initializer expression shall not be an lvalue.
if (RefRelationship >= Sema::Ref_Related && !isLValueRef &&
InitCategory.isLValue()) {
Sequence.SetFailed(
InitializationSequence::FK_RValueReferenceBindingToLValue);
return;
}
Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true);
return;
}
/// \brief Attempt character array initialization from a string literal
/// (C++ [dcl.init.string], C99 6.7.8).
static void TryStringLiteralInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
Expr *Initializer,
InitializationSequence &Sequence) {
Sequence.AddStringInitStep(Entity.getType());
}
/// \brief Attempt value initialization (C++ [dcl.init]p7).
static void TryValueInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
InitializationSequence &Sequence,
InitListExpr *InitList) {
assert((!InitList || InitList->getNumInits() == 0) &&
"Shouldn't use value-init for non-empty init lists");
// C++98 [dcl.init]p5, C++11 [dcl.init]p7:
//
// To value-initialize an object of type T means:
QualType T = Entity.getType();
// -- if T is an array type, then each element is value-initialized;
T = S.Context.getBaseElementType(T);
if (const RecordType *RT = T->getAs<RecordType>()) {
if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
bool NeedZeroInitialization = true;
if (!S.getLangOpts().CPlusPlus11) {
// C++98:
// -- if T is a class type (clause 9) with a user-declared constructor
// (12.1), then the default constructor for T is called (and the
// initialization is ill-formed if T has no accessible default
// constructor);
if (ClassDecl->hasUserDeclaredConstructor())
NeedZeroInitialization = false;
} else {
// C++11:
// -- if T is a class type (clause 9) with either no default constructor
// (12.1 [class.ctor]) or a default constructor that is user-provided
// or deleted, then the object is default-initialized;
CXXConstructorDecl *CD = S.LookupDefaultConstructor(ClassDecl);
if (!CD || !CD->getCanonicalDecl()->isDefaulted() || CD->isDeleted())
NeedZeroInitialization = false;
}
// -- if T is a (possibly cv-qualified) non-union class type without a
// user-provided or deleted default constructor, then the object is
// zero-initialized and, if T has a non-trivial default constructor,
// default-initialized;
// The 'non-union' here was removed by DR1502. The 'non-trivial default
// constructor' part was removed by DR1507.
if (NeedZeroInitialization)
Sequence.AddZeroInitializationStep(Entity.getType());
// C++03:
// -- if T is a non-union class type without a user-declared constructor,
// then every non-static data member and base class component of T is
// value-initialized;
// [...] A program that calls for [...] value-initialization of an
// entity of reference type is ill-formed.
//
// C++11 doesn't need this handling, because value-initialization does not
// occur recursively there, and the implicit default constructor is
// defined as deleted in the problematic cases.
if (!S.getLangOpts().CPlusPlus11 &&
ClassDecl->hasUninitializedReferenceMember()) {
Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForReference);
return;
}
// If this is list-value-initialization, pass the empty init list on when
// building the constructor call. This affects the semantics of a few
// things (such as whether an explicit default constructor can be called).
Expr *InitListAsExpr = InitList;
MultiExprArg Args(&InitListAsExpr, InitList ? 1 : 0);
bool InitListSyntax = InitList;
return TryConstructorInitialization(S, Entity, Kind, Args, T, Sequence,
InitListSyntax);
}
}
Sequence.AddZeroInitializationStep(Entity.getType());
}
/// \brief Attempt default initialization (C++ [dcl.init]p6).
static void TryDefaultInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
InitializationSequence &Sequence) {
assert(Kind.getKind() == InitializationKind::IK_Default);
// C++ [dcl.init]p6:
// To default-initialize an object of type T means:
// - if T is an array type, each element is default-initialized;
QualType DestType = S.Context.getBaseElementType(Entity.getType());
// - if T is a (possibly cv-qualified) class type (Clause 9), the default
// constructor for T is called (and the initialization is ill-formed if
// T has no accessible default constructor);
if (DestType->isRecordType() && S.getLangOpts().CPlusPlus) {
TryConstructorInitialization(S, Entity, Kind, None, DestType, Sequence);
return;
}
// - otherwise, no initialization is performed.
// If a program calls for the default initialization of an object of
// a const-qualified type T, T shall be a class type with a user-provided
// default constructor.
if (DestType.isConstQualified() && S.getLangOpts().CPlusPlus) {
Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst);
return;
}
// If the destination type has a lifetime property, zero-initialize it.
if (DestType.getQualifiers().hasObjCLifetime()) {
Sequence.AddZeroInitializationStep(Entity.getType());
return;
}
}
/// \brief Attempt a user-defined conversion between two types (C++ [dcl.init]),
/// which enumerates all conversion functions and performs overload resolution
/// to select the best.
static void TryUserDefinedConversion(Sema &S,
QualType DestType,
const InitializationKind &Kind,
Expr *Initializer,
InitializationSequence &Sequence,
bool TopLevelOfInitList) {
assert(!DestType->isReferenceType() && "References are handled elsewhere");
QualType SourceType = Initializer->getType();
assert((DestType->isRecordType() || SourceType->isRecordType()) &&
"Must have a class type to perform a user-defined conversion");
// Build the candidate set directly in the initialization sequence
// structure, so that it will persist if we fail.
OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
CandidateSet.clear();
// Determine whether we are allowed to call explicit constructors or
// explicit conversion operators.
bool AllowExplicit = Kind.AllowExplicit();
if (const RecordType *DestRecordType = DestType->getAs<RecordType>()) {
// The type we're converting to is a class type. Enumerate its constructors
// to see if there is a suitable conversion.
CXXRecordDecl *DestRecordDecl
= cast<CXXRecordDecl>(DestRecordType->getDecl());
// Try to complete the type we're converting to.
if (!S.RequireCompleteType(Kind.getLocation(), DestType, 0)) {
DeclContext::lookup_result R = S.LookupConstructors(DestRecordDecl);
// The container holding the constructors can under certain conditions
// be changed while iterating. To be safe we copy the lookup results
// to a new container.
SmallVector<NamedDecl*, 8> CopyOfCon(R.begin(), R.end());
for (SmallVectorImpl<NamedDecl *>::iterator
Con = CopyOfCon.begin(), ConEnd = CopyOfCon.end();
Con != ConEnd; ++Con) {
NamedDecl *D = *Con;
DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess());
// Find the constructor (which may be a template).
CXXConstructorDecl *Constructor = nullptr;
FunctionTemplateDecl *ConstructorTmpl
= dyn_cast<FunctionTemplateDecl>(D);
if (ConstructorTmpl)
Constructor = cast<CXXConstructorDecl>(
ConstructorTmpl->getTemplatedDecl());
else
Constructor = cast<CXXConstructorDecl>(D);
if (!Constructor->isInvalidDecl() &&
Constructor->isConvertingConstructor(AllowExplicit)) {
if (ConstructorTmpl)
S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl,
/*ExplicitArgs*/ nullptr,
Initializer, CandidateSet,
/*SuppressUserConversions=*/true);
else
S.AddOverloadCandidate(Constructor, FoundDecl,
Initializer, CandidateSet,
/*SuppressUserConversions=*/true);
}
}
}
}
SourceLocation DeclLoc = Initializer->getLocStart();
if (const RecordType *SourceRecordType = SourceType->getAs<RecordType>()) {
// The type we're converting from is a class type, enumerate its conversion
// functions.
// We can only enumerate the conversion functions for a complete type; if
// the type isn't complete, simply skip this step.
if (!S.RequireCompleteType(DeclLoc, SourceType, 0)) {
CXXRecordDecl *SourceRecordDecl
= cast<CXXRecordDecl>(SourceRecordType->getDecl());
std::pair<CXXRecordDecl::conversion_iterator,
CXXRecordDecl::conversion_iterator>
Conversions = SourceRecordDecl->getVisibleConversionFunctions();
for (CXXRecordDecl::conversion_iterator
I = Conversions.first, E = Conversions.second; I != E; ++I) {
NamedDecl *D = *I;
CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
CXXConversionDecl *Conv;
if (ConvTemplate)
Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
else
Conv = cast<CXXConversionDecl>(D);
if (AllowExplicit || !Conv->isExplicit()) {
if (ConvTemplate)
S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(),
ActingDC, Initializer, DestType,
CandidateSet, AllowExplicit);
else
S.AddConversionCandidate(Conv, I.getPair(), ActingDC,
Initializer, DestType, CandidateSet,
AllowExplicit);
}
}
}
}
// Perform overload resolution. If it fails, return the failed result.
OverloadCandidateSet::iterator Best;
if (OverloadingResult Result
= CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) {
Sequence.SetOverloadFailure(
InitializationSequence::FK_UserConversionOverloadFailed,
Result);
return;
}
FunctionDecl *Function = Best->Function;
Function->setReferenced();
bool HadMultipleCandidates = (CandidateSet.size() > 1);
if (isa<CXXConstructorDecl>(Function)) {
// Add the user-defined conversion step. Any cv-qualification conversion is
// subsumed by the initialization. Per DR5, the created temporary is of the
// cv-unqualified type of the destination.
Sequence.AddUserConversionStep(Function, Best->FoundDecl,
DestType.getUnqualifiedType(),
HadMultipleCandidates);
return;
}
// Add the user-defined conversion step that calls the conversion function.
QualType ConvType = Function->getCallResultType();
if (ConvType->getAs<RecordType>()) {
// If we're converting to a class type, there may be an copy of
// the resulting temporary object (possible to create an object of
// a base class type). That copy is not a separate conversion, so
// we just make a note of the actual destination type (possibly a
// base class of the type returned by the conversion function) and
// let the user-defined conversion step handle the conversion.
Sequence.AddUserConversionStep(Function, Best->FoundDecl, DestType,
HadMultipleCandidates);
return;
}
Sequence.AddUserConversionStep(Function, Best->FoundDecl, ConvType,
HadMultipleCandidates);
// If the conversion following the call to the conversion function
// is interesting, add it as a separate step.
if (Best->FinalConversion.First || Best->FinalConversion.Second ||
Best->FinalConversion.Third) {
ImplicitConversionSequence ICS;
ICS.setStandard();
ICS.Standard = Best->FinalConversion;
Sequence.AddConversionSequenceStep(ICS, DestType, TopLevelOfInitList);
}
}
/// An egregious hack for compatibility with libstdc++-4.2: in <tr1/hashtable>,
/// a function with a pointer return type contains a 'return false;' statement.
/// In C++11, 'false' is not a null pointer, so this breaks the build of any
/// code using that header.
///
/// Work around this by treating 'return false;' as zero-initializing the result
/// if it's used in a pointer-returning function in a system header.
static bool isLibstdcxxPointerReturnFalseHack(Sema &S,
const InitializedEntity &Entity,
const Expr *Init) {
return S.getLangOpts().CPlusPlus11 &&
Entity.getKind() == InitializedEntity::EK_Result &&
Entity.getType()->isPointerType() &&
isa<CXXBoolLiteralExpr>(Init) &&
!cast<CXXBoolLiteralExpr>(Init)->getValue() &&
S.getSourceManager().isInSystemHeader(Init->getExprLoc());
}
/// The non-zero enum values here are indexes into diagnostic alternatives.
enum InvalidICRKind { IIK_okay, IIK_nonlocal, IIK_nonscalar };
/// Determines whether this expression is an acceptable ICR source.
static InvalidICRKind isInvalidICRSource(ASTContext &C, Expr *e,
bool isAddressOf, bool &isWeakAccess) {
// Skip parens.
e = e->IgnoreParens();
// Skip address-of nodes.
if (UnaryOperator *op = dyn_cast<UnaryOperator>(e)) {
if (op->getOpcode() == UO_AddrOf)
return isInvalidICRSource(C, op->getSubExpr(), /*addressof*/ true,
isWeakAccess);
// Skip certain casts.
} else if (CastExpr *ce = dyn_cast<CastExpr>(e)) {
switch (ce->getCastKind()) {
case CK_Dependent:
case CK_BitCast:
case CK_LValueBitCast:
case CK_NoOp:
return isInvalidICRSource(C, ce->getSubExpr(), isAddressOf, isWeakAccess);
case CK_ArrayToPointerDecay:
return IIK_nonscalar;
case CK_NullToPointer:
return IIK_okay;
default:
break;
}
// If we have a declaration reference, it had better be a local variable.
} else if (isa<DeclRefExpr>(e)) {
// set isWeakAccess to true, to mean that there will be an implicit
// load which requires a cleanup.
if (e->getType().getObjCLifetime() == Qualifiers::OCL_Weak)
isWeakAccess = true;
if (!isAddressOf) return IIK_nonlocal;
VarDecl *var = dyn_cast<VarDecl>(cast<DeclRefExpr>(e)->getDecl());
if (!var) return IIK_nonlocal;
return (var->hasLocalStorage() ? IIK_okay : IIK_nonlocal);
// If we have a conditional operator, check both sides.
} else if (ConditionalOperator *cond = dyn_cast<ConditionalOperator>(e)) {
if (InvalidICRKind iik = isInvalidICRSource(C, cond->getLHS(), isAddressOf,
isWeakAccess))
return iik;
return isInvalidICRSource(C, cond->getRHS(), isAddressOf, isWeakAccess);
// These are never scalar.
} else if (isa<ArraySubscriptExpr>(e)) {
return IIK_nonscalar;
// Otherwise, it needs to be a null pointer constant.
} else {
return (e->isNullPointerConstant(C, Expr::NPC_ValueDependentIsNull)
? IIK_okay : IIK_nonlocal);
}
return IIK_nonlocal;
}
/// Check whether the given expression is a valid operand for an
/// indirect copy/restore.
static void checkIndirectCopyRestoreSource(Sema &S, Expr *src) {
assert(src->isRValue());
bool isWeakAccess = false;
InvalidICRKind iik = isInvalidICRSource(S.Context, src, false, isWeakAccess);
// If isWeakAccess to true, there will be an implicit
// load which requires a cleanup.
if (S.getLangOpts().ObjCAutoRefCount && isWeakAccess)
S.ExprNeedsCleanups = true;
if (iik == IIK_okay) return;
S.Diag(src->getExprLoc(), diag::err_arc_nonlocal_writeback)
<< ((unsigned) iik - 1) // shift index into diagnostic explanations
<< src->getSourceRange();
}
/// \brief Determine whether we have compatible array types for the
/// purposes of GNU by-copy array initialization.
static bool hasCompatibleArrayTypes(ASTContext &Context,
const ArrayType *Dest,
const ArrayType *Source) {
// If the source and destination array types are equivalent, we're
// done.
if (Context.hasSameType(QualType(Dest, 0), QualType(Source, 0)))
return true;
// Make sure that the element types are the same.
if (!Context.hasSameType(Dest->getElementType(), Source->getElementType()))
return false;
// The only mismatch we allow is when the destination is an
// incomplete array type and the source is a constant array type.
return Source->isConstantArrayType() && Dest->isIncompleteArrayType();
}
static bool tryObjCWritebackConversion(Sema &S,
InitializationSequence &Sequence,
const InitializedEntity &Entity,
Expr *Initializer) {
bool ArrayDecay = false;
QualType ArgType = Initializer->getType();
QualType ArgPointee;
if (const ArrayType *ArgArrayType = S.Context.getAsArrayType(ArgType)) {
ArrayDecay = true;
ArgPointee = ArgArrayType->getElementType();
ArgType = S.Context.getPointerType(ArgPointee);
}
// Handle write-back conversion.
QualType ConvertedArgType;
if (!S.isObjCWritebackConversion(ArgType, Entity.getType(),
ConvertedArgType))
return false;
// We should copy unless we're passing to an argument explicitly
// marked 'out'.
bool ShouldCopy = true;
if (ParmVarDecl *param = cast_or_null<ParmVarDecl>(Entity.getDecl()))
ShouldCopy = (param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out);
// Do we need an lvalue conversion?
if (ArrayDecay || Initializer->isGLValue()) {
ImplicitConversionSequence ICS;
ICS.setStandard();
ICS.Standard.setAsIdentityConversion();
QualType ResultType;
if (ArrayDecay) {
ICS.Standard.First = ICK_Array_To_Pointer;
ResultType = S.Context.getPointerType(ArgPointee);
} else {
ICS.Standard.First = ICK_Lvalue_To_Rvalue;
ResultType = Initializer->getType().getNonLValueExprType(S.Context);
}
Sequence.AddConversionSequenceStep(ICS, ResultType);
}
Sequence.AddPassByIndirectCopyRestoreStep(Entity.getType(), ShouldCopy);
return true;
}
static bool TryOCLSamplerInitialization(Sema &S,
InitializationSequence &Sequence,
QualType DestType,
Expr *Initializer) {
if (!S.getLangOpts().OpenCL || !DestType->isSamplerT() ||
!Initializer->isIntegerConstantExpr(S.getASTContext()))
return false;
Sequence.AddOCLSamplerInitStep(DestType);
return true;
}
//
// OpenCL 1.2 spec, s6.12.10
//
// The event argument can also be used to associate the
// async_work_group_copy with a previous async copy allowing
// an event to be shared by multiple async copies; otherwise
// event should be zero.
//
static bool TryOCLZeroEventInitialization(Sema &S,
InitializationSequence &Sequence,
QualType DestType,
Expr *Initializer) {
if (!S.getLangOpts().OpenCL || !DestType->isEventT() ||
!Initializer->isIntegerConstantExpr(S.getASTContext()) ||
(Initializer->EvaluateKnownConstInt(S.getASTContext()) != 0))
return false;
Sequence.AddOCLZeroEventStep(DestType);
return true;
}
InitializationSequence::InitializationSequence(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
MultiExprArg Args,
bool TopLevelOfInitList)
: FailedCandidateSet(Kind.getLocation(), OverloadCandidateSet::CSK_Normal) {
InitializeFrom(S, Entity, Kind, Args, TopLevelOfInitList);
}
void InitializationSequence::InitializeFrom(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
MultiExprArg Args,
bool TopLevelOfInitList) {
ASTContext &Context = S.Context;
// Eliminate non-overload placeholder types in the arguments. We
// need to do this before checking whether types are dependent
// because lowering a pseudo-object expression might well give us
// something of dependent type.
for (unsigned I = 0, E = Args.size(); I != E; ++I)
if (Args[I]->getType()->isNonOverloadPlaceholderType()) {
// FIXME: should we be doing this here?
ExprResult result = S.CheckPlaceholderExpr(Args[I]);
if (result.isInvalid()) {
SetFailed(FK_PlaceholderType);
return;
}
Args[I] = result.get();
}
// C++0x [dcl.init]p16:
// The semantics of initializers are as follows. The destination type is
// the type of the object or reference being initialized and the source
// type is the type of the initializer expression. The source type is not
// defined when the initializer is a braced-init-list or when it is a
// parenthesized list of expressions.
QualType DestType = Entity.getType();
if (DestType->isDependentType() ||
Expr::hasAnyTypeDependentArguments(Args)) {
SequenceKind = DependentSequence;
return;
}
// Almost everything is a normal sequence.
setSequenceKind(NormalSequence);
QualType SourceType;
Expr *Initializer = nullptr;
if (Args.size() == 1) {
Initializer = Args[0];
if (S.getLangOpts().ObjC1) {
if (S.CheckObjCBridgeRelatedConversions(Initializer->getLocStart(),
DestType, Initializer->getType(),
Initializer) ||
S.ConversionToObjCStringLiteralCheck(DestType, Initializer))
Args[0] = Initializer;
}
if (!isa<InitListExpr>(Initializer))
SourceType = Initializer->getType();
}
// - If the initializer is a (non-parenthesized) braced-init-list, the
// object is list-initialized (8.5.4).
if (Kind.getKind() != InitializationKind::IK_Direct) {
if (InitListExpr *InitList = dyn_cast_or_null<InitListExpr>(Initializer)) {
TryListInitialization(S, Entity, Kind, InitList, *this);
return;
}
}
// - If the destination type is a reference type, see 8.5.3.
if (DestType->isReferenceType()) {
// C++0x [dcl.init.ref]p1:
// A variable declared to be a T& or T&&, that is, "reference to type T"
// (8.3.2), shall be initialized by an object, or function, of type T or
// by an object that can be converted into a T.
// (Therefore, multiple arguments are not permitted.)
if (Args.size() != 1)
SetFailed(FK_TooManyInitsForReference);
else
TryReferenceInitialization(S, Entity, Kind, Args[0], *this);
return;
}
// - If the initializer is (), the object is value-initialized.
if (Kind.getKind() == InitializationKind::IK_Value ||
(Kind.getKind() == InitializationKind::IK_Direct && Args.empty())) {
TryValueInitialization(S, Entity, Kind, *this);
return;
}
// Handle default initialization.
if (Kind.getKind() == InitializationKind::IK_Default) {
TryDefaultInitialization(S, Entity, Kind, *this);
return;
}
// - If the destination type is an array of characters, an array of
// char16_t, an array of char32_t, or an array of wchar_t, and the
// initializer is a string literal, see 8.5.2.
// - Otherwise, if the destination type is an array, the program is
// ill-formed.
if (const ArrayType *DestAT = Context.getAsArrayType(DestType)) {
if (Initializer && isa<VariableArrayType>(DestAT)) {
SetFailed(FK_VariableLengthArrayHasInitializer);
return;
}
if (Initializer) {
switch (IsStringInit(Initializer, DestAT, Context)) {
case SIF_None:
TryStringLiteralInitialization(S, Entity, Kind, Initializer, *this);
return;
case SIF_NarrowStringIntoWideChar:
SetFailed(FK_NarrowStringIntoWideCharArray);
return;
case SIF_WideStringIntoChar:
SetFailed(FK_WideStringIntoCharArray);
return;
case SIF_IncompatWideStringIntoWideChar:
SetFailed(FK_IncompatWideStringIntoWideChar);
return;
case SIF_Other:
break;
}
}
// Note: as an GNU C extension, we allow initialization of an
// array from a compound literal that creates an array of the same
// type, so long as the initializer has no side effects.
if (!S.getLangOpts().CPlusPlus && Initializer &&
isa<CompoundLiteralExpr>(Initializer->IgnoreParens()) &&
Initializer->getType()->isArrayType()) {
const ArrayType *SourceAT
= Context.getAsArrayType(Initializer->getType());
if (!hasCompatibleArrayTypes(S.Context, DestAT, SourceAT))
SetFailed(FK_ArrayTypeMismatch);
else if (Initializer->HasSideEffects(S.Context))
SetFailed(FK_NonConstantArrayInit);
else {
AddArrayInitStep(DestType);
}
}
// Note: as a GNU C++ extension, we allow list-initialization of a
// class member of array type from a parenthesized initializer list.
else if (S.getLangOpts().CPlusPlus &&
Entity.getKind() == InitializedEntity::EK_Member &&
Initializer && isa<InitListExpr>(Initializer)) {
TryListInitialization(S, Entity, Kind, cast<InitListExpr>(Initializer),
*this);
AddParenthesizedArrayInitStep(DestType);
} else if (DestAT->getElementType()->isCharType())
SetFailed(FK_ArrayNeedsInitListOrStringLiteral);
else if (IsWideCharCompatible(DestAT->getElementType(), Context))
SetFailed(FK_ArrayNeedsInitListOrWideStringLiteral);
else
SetFailed(FK_ArrayNeedsInitList);
return;
}
// Determine whether we should consider writeback conversions for
// Objective-C ARC.
bool allowObjCWritebackConversion = S.getLangOpts().ObjCAutoRefCount &&
Entity.isParameterKind();
// We're at the end of the line for C: it's either a write-back conversion
// or it's a C assignment. There's no need to check anything else.
if (!S.getLangOpts().CPlusPlus) {
// If allowed, check whether this is an Objective-C writeback conversion.
if (allowObjCWritebackConversion &&
tryObjCWritebackConversion(S, *this, Entity, Initializer)) {
return;
}
if (TryOCLSamplerInitialization(S, *this, DestType, Initializer))
return;
if (TryOCLZeroEventInitialization(S, *this, DestType, Initializer))
return;
// Handle initialization in C
AddCAssignmentStep(DestType);
MaybeProduceObjCObject(S, *this, Entity);
return;
}
assert(S.getLangOpts().CPlusPlus);
// - If the destination type is a (possibly cv-qualified) class type:
if (DestType->isRecordType()) {
// - If the initialization is direct-initialization, or if it is
// copy-initialization where the cv-unqualified version of the
// source type is the same class as, or a derived class of, the
// class of the destination, constructors are considered. [...]
if (Kind.getKind() == InitializationKind::IK_Direct ||
(Kind.getKind() == InitializationKind::IK_Copy &&
(Context.hasSameUnqualifiedType(SourceType, DestType) ||
S.IsDerivedFrom(SourceType, DestType))))
TryConstructorInitialization(S, Entity, Kind, Args,
DestType, *this);
// - Otherwise (i.e., for the remaining copy-initialization cases),
// user-defined conversion sequences that can convert from the source
// type to the destination type or (when a conversion function is
// used) to a derived class thereof are enumerated as described in
// 13.3.1.4, and the best one is chosen through overload resolution
// (13.3).
else
TryUserDefinedConversion(S, DestType, Kind, Initializer, *this,
TopLevelOfInitList);
return;
}
if (Args.size() > 1) {
SetFailed(FK_TooManyInitsForScalar);
return;
}
assert(Args.size() == 1 && "Zero-argument case handled above");
// - Otherwise, if the source type is a (possibly cv-qualified) class
// type, conversion functions are considered.
if (!SourceType.isNull() && SourceType->isRecordType()) {
// For a conversion to _Atomic(T) from either T or a class type derived
// from T, initialize the T object then convert to _Atomic type.
bool NeedAtomicConversion = false;
if (const AtomicType *Atomic = DestType->getAs<AtomicType>()) {
if (Context.hasSameUnqualifiedType(SourceType, Atomic->getValueType()) ||
S.IsDerivedFrom(SourceType, Atomic->getValueType())) {
DestType = Atomic->getValueType();
NeedAtomicConversion = true;
}
}
TryUserDefinedConversion(S, DestType, Kind, Initializer, *this,
TopLevelOfInitList);
MaybeProduceObjCObject(S, *this, Entity);
if (!Failed() && NeedAtomicConversion)
AddAtomicConversionStep(Entity.getType());
return;
}
// - Otherwise, the initial value of the object being initialized is the
// (possibly converted) value of the initializer expression. Standard
// conversions (Clause 4) will be used, if necessary, to convert the
// initializer expression to the cv-unqualified version of the
// destination type; no user-defined conversions are considered.
ImplicitConversionSequence ICS
= S.TryImplicitConversion(Initializer, DestType,
/*SuppressUserConversions*/true,
/*AllowExplicitConversions*/ false,
/*InOverloadResolution*/ false,
/*CStyle=*/Kind.isCStyleOrFunctionalCast(),
allowObjCWritebackConversion);
if (ICS.isStandard() &&
ICS.Standard.Second == ICK_Writeback_Conversion) {
// Objective-C ARC writeback conversion.
// We should copy unless we're passing to an argument explicitly
// marked 'out'.
bool ShouldCopy = true;
if (ParmVarDecl *Param = cast_or_null<ParmVarDecl>(Entity.getDecl()))
ShouldCopy = (Param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out);
// If there was an lvalue adjustment, add it as a separate conversion.
if (ICS.Standard.First == ICK_Array_To_Pointer ||
ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
ImplicitConversionSequence LvalueICS;
LvalueICS.setStandard();
LvalueICS.Standard.setAsIdentityConversion();
LvalueICS.Standard.setAllToTypes(ICS.Standard.getToType(0));
LvalueICS.Standard.First = ICS.Standard.First;
AddConversionSequenceStep(LvalueICS, ICS.Standard.getToType(0));
}
AddPassByIndirectCopyRestoreStep(DestType, ShouldCopy);
} else if (ICS.isBad()) {
DeclAccessPair dap;
if (isLibstdcxxPointerReturnFalseHack(S, Entity, Initializer)) {
AddZeroInitializationStep(Entity.getType());
} else if (Initializer->getType() == Context.OverloadTy &&
!S.ResolveAddressOfOverloadedFunction(Initializer, DestType,
false, dap))
SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
else
SetFailed(InitializationSequence::FK_ConversionFailed);
} else {
AddConversionSequenceStep(ICS, DestType, TopLevelOfInitList);
MaybeProduceObjCObject(S, *this, Entity);
}
}
InitializationSequence::~InitializationSequence() {
for (SmallVectorImpl<Step>::iterator Step = Steps.begin(),
StepEnd = Steps.end();
Step != StepEnd; ++Step)
Step->Destroy();
}
//===----------------------------------------------------------------------===//
// Perform initialization
//===----------------------------------------------------------------------===//
static Sema::AssignmentAction
getAssignmentAction(const InitializedEntity &Entity, bool Diagnose = false) {
switch(Entity.getKind()) {
case InitializedEntity::EK_Variable:
case InitializedEntity::EK_New:
case InitializedEntity::EK_Exception:
case InitializedEntity::EK_Base:
case InitializedEntity::EK_Delegating:
return Sema::AA_Initializing;
case InitializedEntity::EK_Parameter:
if (Entity.getDecl() &&
isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext()))
return Sema::AA_Sending;
return Sema::AA_Passing;
case InitializedEntity::EK_Parameter_CF_Audited:
if (Entity.getDecl() &&
isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext()))
return Sema::AA_Sending;
return !Diagnose ? Sema::AA_Passing : Sema::AA_Passing_CFAudited;
case InitializedEntity::EK_Result:
return Sema::AA_Returning;
case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_RelatedResult:
// FIXME: Can we tell apart casting vs. converting?
return Sema::AA_Casting;
case InitializedEntity::EK_Member:
case InitializedEntity::EK_ArrayElement:
case InitializedEntity::EK_VectorElement:
case InitializedEntity::EK_ComplexElement:
case InitializedEntity::EK_BlockElement:
case InitializedEntity::EK_LambdaCapture:
case InitializedEntity::EK_CompoundLiteralInit:
return Sema::AA_Initializing;
}
llvm_unreachable("Invalid EntityKind!");
}
/// \brief Whether we should bind a created object as a temporary when
/// initializing the given entity.
static bool shouldBindAsTemporary(const InitializedEntity &Entity) {
switch (Entity.getKind()) {
case InitializedEntity::EK_ArrayElement:
case InitializedEntity::EK_Member:
case InitializedEntity::EK_Result:
case InitializedEntity::EK_New:
case InitializedEntity::EK_Variable:
case InitializedEntity::EK_Base:
case InitializedEntity::EK_Delegating:
case InitializedEntity::EK_VectorElement:
case InitializedEntity::EK_ComplexElement:
case InitializedEntity::EK_Exception:
case InitializedEntity::EK_BlockElement:
case InitializedEntity::EK_LambdaCapture:
case InitializedEntity::EK_CompoundLiteralInit:
return false;
case InitializedEntity::EK_Parameter:
case InitializedEntity::EK_Parameter_CF_Audited:
case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_RelatedResult:
return true;
}
llvm_unreachable("missed an InitializedEntity kind?");
}
/// \brief Whether the given entity, when initialized with an object
/// created for that initialization, requires destruction.
static bool shouldDestroyTemporary(const InitializedEntity &Entity) {
switch (Entity.getKind()) {
case InitializedEntity::EK_Result:
case InitializedEntity::EK_New:
case InitializedEntity::EK_Base:
case InitializedEntity::EK_Delegating:
case InitializedEntity::EK_VectorElement:
case InitializedEntity::EK_ComplexElement:
case InitializedEntity::EK_BlockElement:
case InitializedEntity::EK_LambdaCapture:
return false;
case InitializedEntity::EK_Member:
case InitializedEntity::EK_Variable:
case InitializedEntity::EK_Parameter:
case InitializedEntity::EK_Parameter_CF_Audited:
case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_ArrayElement:
case InitializedEntity::EK_Exception:
case InitializedEntity::EK_CompoundLiteralInit:
case InitializedEntity::EK_RelatedResult:
return true;
}
llvm_unreachable("missed an InitializedEntity kind?");
}
/// \brief Look for copy and move constructors and constructor templates, for
/// copying an object via direct-initialization (per C++11 [dcl.init]p16).
static void LookupCopyAndMoveConstructors(Sema &S,
OverloadCandidateSet &CandidateSet,
CXXRecordDecl *Class,
Expr *CurInitExpr) {
DeclContext::lookup_result R = S.LookupConstructors(Class);
// The container holding the constructors can under certain conditions
// be changed while iterating (e.g. because of deserialization).
// To be safe we copy the lookup results to a new container.
SmallVector<NamedDecl*, 16> Ctors(R.begin(), R.end());
for (SmallVectorImpl<NamedDecl *>::iterator
CI = Ctors.begin(), CE = Ctors.end(); CI != CE; ++CI) {
NamedDecl *D = *CI;
CXXConstructorDecl *Constructor = nullptr;
if ((Constructor = dyn_cast<CXXConstructorDecl>(D))) {
// Handle copy/moveconstructors, only.
if (!Constructor || Constructor->isInvalidDecl() ||
!Constructor->isCopyOrMoveConstructor() ||
!Constructor->isConvertingConstructor(/*AllowExplicit=*/true))
continue;
DeclAccessPair FoundDecl
= DeclAccessPair::make(Constructor, Constructor->getAccess());
S.AddOverloadCandidate(Constructor, FoundDecl,
CurInitExpr, CandidateSet);
continue;
}
// Handle constructor templates.
FunctionTemplateDecl *ConstructorTmpl = cast<FunctionTemplateDecl>(D);
if (ConstructorTmpl->isInvalidDecl())
continue;
Constructor = cast<CXXConstructorDecl>(
ConstructorTmpl->getTemplatedDecl());
if (!Constructor->isConvertingConstructor(/*AllowExplicit=*/true))
continue;
// FIXME: Do we need to limit this to copy-constructor-like
// candidates?
DeclAccessPair FoundDecl
= DeclAccessPair::make(ConstructorTmpl, ConstructorTmpl->getAccess());
S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, nullptr,
CurInitExpr, CandidateSet, true);
}
}
/// \brief Get the location at which initialization diagnostics should appear.
static SourceLocation getInitializationLoc(const InitializedEntity &Entity,
Expr *Initializer) {
switch (Entity.getKind()) {
case InitializedEntity::EK_Result:
return Entity.getReturnLoc();
case InitializedEntity::EK_Exception:
return Entity.getThrowLoc();
case InitializedEntity::EK_Variable:
return Entity.getDecl()->getLocation();
case InitializedEntity::EK_LambdaCapture:
return Entity.getCaptureLoc();
case InitializedEntity::EK_ArrayElement:
case InitializedEntity::EK_Member:
case InitializedEntity::EK_Parameter:
case InitializedEntity::EK_Parameter_CF_Audited:
case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_New:
case InitializedEntity::EK_Base:
case InitializedEntity::EK_Delegating:
case InitializedEntity::EK_VectorElement:
case InitializedEntity::EK_ComplexElement:
case InitializedEntity::EK_BlockElement:
case InitializedEntity::EK_CompoundLiteralInit:
case InitializedEntity::EK_RelatedResult:
return Initializer->getLocStart();
}
llvm_unreachable("missed an InitializedEntity kind?");
}
/// \brief Make a (potentially elidable) temporary copy of the object
/// provided by the given initializer by calling the appropriate copy
/// constructor.
///
/// \param S The Sema object used for type-checking.
///
/// \param T The type of the temporary object, which must either be
/// the type of the initializer expression or a superclass thereof.
///
/// \param Entity The entity being initialized.
///
/// \param CurInit The initializer expression.
///
/// \param IsExtraneousCopy Whether this is an "extraneous" copy that
/// is permitted in C++03 (but not C++0x) when binding a reference to
/// an rvalue.
///
/// \returns An expression that copies the initializer expression into
/// a temporary object, or an error expression if a copy could not be
/// created.
static ExprResult CopyObject(Sema &S,
QualType T,
const InitializedEntity &Entity,
ExprResult CurInit,
bool IsExtraneousCopy) {
// Determine which class type we're copying to.
Expr *CurInitExpr = (Expr *)CurInit.get();
CXXRecordDecl *Class = nullptr;
if (const RecordType *Record = T->getAs<RecordType>())
Class = cast<CXXRecordDecl>(Record->getDecl());
if (!Class)
return CurInit;
// C++0x [class.copy]p32:
// When certain criteria are met, an implementation is allowed to
// omit the copy/move construction of a class object, even if the
// copy/move constructor and/or destructor for the object have
// side effects. [...]
// - when a temporary class object that has not been bound to a
// reference (12.2) would be copied/moved to a class object
// with the same cv-unqualified type, the copy/move operation
// can be omitted by constructing the temporary object
// directly into the target of the omitted copy/move
//
// Note that the other three bullets are handled elsewhere. Copy
// elision for return statements and throw expressions are handled as part
// of constructor initialization, while copy elision for exception handlers
// is handled by the run-time.
bool Elidable = CurInitExpr->isTemporaryObject(S.Context, Class);
SourceLocation Loc = getInitializationLoc(Entity, CurInit.get());
// Make sure that the type we are copying is complete.
if (S.RequireCompleteType(Loc, T, diag::err_temp_copy_incomplete))
return CurInit;
// Perform overload resolution using the class's copy/move constructors.
// Only consider constructors and constructor templates. Per
// C++0x [dcl.init]p16, second bullet to class types, this initialization
// is direct-initialization.
OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
LookupCopyAndMoveConstructors(S, CandidateSet, Class, CurInitExpr);
bool HadMultipleCandidates = (CandidateSet.size() > 1);
OverloadCandidateSet::iterator Best;
switch (CandidateSet.BestViableFunction(S, Loc, Best)) {
case OR_Success:
break;
case OR_No_Viable_Function:
S.Diag(Loc, IsExtraneousCopy && !S.isSFINAEContext()
? diag::ext_rvalue_to_reference_temp_copy_no_viable
: diag::err_temp_copy_no_viable)
<< (int)Entity.getKind() << CurInitExpr->getType()
<< CurInitExpr->getSourceRange();
CandidateSet.NoteCandidates(S, OCD_AllCandidates, CurInitExpr);
if (!IsExtraneousCopy || S.isSFINAEContext())
return ExprError();
return CurInit;
case OR_Ambiguous:
S.Diag(Loc, diag::err_temp_copy_ambiguous)
<< (int)Entity.getKind() << CurInitExpr->getType()
<< CurInitExpr->getSourceRange();
CandidateSet.NoteCandidates(S, OCD_ViableCandidates, CurInitExpr);
return ExprError();
case OR_Deleted:
S.Diag(Loc, diag::err_temp_copy_deleted)
<< (int)Entity.getKind() << CurInitExpr->getType()
<< CurInitExpr->getSourceRange();
S.NoteDeletedFunction(Best->Function);
return ExprError();
}
CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
SmallVector<Expr*, 8> ConstructorArgs;
CurInit.get(); // Ownership transferred into MultiExprArg, below.
S.CheckConstructorAccess(Loc, Constructor, Entity,
Best->FoundDecl.getAccess(), IsExtraneousCopy);
if (IsExtraneousCopy) {
// If this is a totally extraneous copy for C++03 reference
// binding purposes, just return the original initialization
// expression. We don't generate an (elided) copy operation here
// because doing so would require us to pass down a flag to avoid
// infinite recursion, where each step adds another extraneous,
// elidable copy.
// Instantiate the default arguments of any extra parameters in
// the selected copy constructor, as if we were going to create a
// proper call to the copy constructor.
for (unsigned I = 1, N = Constructor->getNumParams(); I != N; ++I) {
ParmVarDecl *Parm = Constructor->getParamDecl(I);
if (S.RequireCompleteType(Loc, Parm->getType(),
diag::err_call_incomplete_argument))
break;
// Build the default argument expression; we don't actually care
// if this succeeds or not, because this routine will complain
// if there was a problem.
S.BuildCXXDefaultArgExpr(Loc, Constructor, Parm);
}
return CurInitExpr;
}
// Determine the arguments required to actually perform the
// constructor call (we might have derived-to-base conversions, or
// the copy constructor may have default arguments).
if (S.CompleteConstructorCall(Constructor, CurInitExpr, Loc, ConstructorArgs))
return ExprError();
// Actually perform the constructor call.
CurInit = S.BuildCXXConstructExpr(Loc, T, Constructor, Elidable,
ConstructorArgs,
HadMultipleCandidates,
/*ListInit*/ false,
/*StdInitListInit*/ false,
/*ZeroInit*/ false,
CXXConstructExpr::CK_Complete,
SourceRange());
// If we're supposed to bind temporaries, do so.
if (!CurInit.isInvalid() && shouldBindAsTemporary(Entity))
CurInit = S.MaybeBindToTemporary(CurInit.getAs<Expr>());
return CurInit;
}
/// \brief Check whether elidable copy construction for binding a reference to
/// a temporary would have succeeded if we were building in C++98 mode, for
/// -Wc++98-compat.
static void CheckCXX98CompatAccessibleCopy(Sema &S,
const InitializedEntity &Entity,
Expr *CurInitExpr) {
assert(S.getLangOpts().CPlusPlus11);
const RecordType *Record = CurInitExpr->getType()->getAs<RecordType>();
if (!Record)
return;
SourceLocation Loc = getInitializationLoc(Entity, CurInitExpr);
if (S.Diags.isIgnored(diag::warn_cxx98_compat_temp_copy, Loc))
return;
// Find constructors which would have been considered.
OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
LookupCopyAndMoveConstructors(
S, CandidateSet, cast<CXXRecordDecl>(Record->getDecl()), CurInitExpr);
// Perform overload resolution.
OverloadCandidateSet::iterator Best;
OverloadingResult OR = CandidateSet.BestViableFunction(S, Loc, Best);
PartialDiagnostic Diag = S.PDiag(diag::warn_cxx98_compat_temp_copy)
<< OR << (int)Entity.getKind() << CurInitExpr->getType()
<< CurInitExpr->getSourceRange();
switch (OR) {
case OR_Success:
S.CheckConstructorAccess(Loc, cast<CXXConstructorDecl>(Best->Function),
Entity, Best->FoundDecl.getAccess(), Diag);
// FIXME: Check default arguments as far as that's possible.
break;
case OR_No_Viable_Function:
S.Diag(Loc, Diag);
CandidateSet.NoteCandidates(S, OCD_AllCandidates, CurInitExpr);
break;
case OR_Ambiguous:
S.Diag(Loc, Diag);
CandidateSet.NoteCandidates(S, OCD_ViableCandidates, CurInitExpr);
break;
case OR_Deleted:
S.Diag(Loc, Diag);
S.NoteDeletedFunction(Best->Function);
break;
}
}
void InitializationSequence::PrintInitLocationNote(Sema &S,
const InitializedEntity &Entity) {
if (Entity.isParameterKind() && Entity.getDecl()) {
if (Entity.getDecl()->getLocation().isInvalid())
return;
if (Entity.getDecl()->getDeclName())
S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_named_here)
<< Entity.getDecl()->getDeclName();
else
S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_here);
}
else if (Entity.getKind() == InitializedEntity::EK_RelatedResult &&
Entity.getMethodDecl())
S.Diag(Entity.getMethodDecl()->getLocation(),
diag::note_method_return_type_change)
<< Entity.getMethodDecl()->getDeclName();
}
static bool isReferenceBinding(const InitializationSequence::Step &s) {
return s.Kind == InitializationSequence::SK_BindReference ||
s.Kind == InitializationSequence::SK_BindReferenceToTemporary;
}
/// Returns true if the parameters describe a constructor initialization of
/// an explicit temporary object, e.g. "Point(x, y)".
static bool isExplicitTemporary(const InitializedEntity &Entity,
const InitializationKind &Kind,
unsigned NumArgs) {
switch (Entity.getKind()) {
case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_CompoundLiteralInit:
case InitializedEntity::EK_RelatedResult:
break;
default:
return false;
}
switch (Kind.getKind()) {
case InitializationKind::IK_DirectList:
return true;
// FIXME: Hack to work around cast weirdness.
case InitializationKind::IK_Direct:
case InitializationKind::IK_Value:
return NumArgs != 1;
default:
return false;
}
}
static ExprResult
PerformConstructorInitialization(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
MultiExprArg Args,
const InitializationSequence::Step& Step,
bool &ConstructorInitRequiresZeroInit,
bool IsListInitialization,
bool IsStdInitListInitialization,
SourceLocation LBraceLoc,
SourceLocation RBraceLoc) {
unsigned NumArgs = Args.size();
CXXConstructorDecl *Constructor
= cast<CXXConstructorDecl>(Step.Function.Function);
bool HadMultipleCandidates = Step.Function.HadMultipleCandidates;
// Build a call to the selected constructor.
SmallVector<Expr*, 8> ConstructorArgs;
SourceLocation Loc = (Kind.isCopyInit() && Kind.getEqualLoc().isValid())
? Kind.getEqualLoc()
: Kind.getLocation();
if (Kind.getKind() == InitializationKind::IK_Default) {
// Force even a trivial, implicit default constructor to be
// semantically checked. We do this explicitly because we don't build
// the definition for completely trivial constructors.
assert(Constructor->getParent() && "No parent class for constructor.");
if (Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&
Constructor->isTrivial() && !Constructor->isUsed(false))
S.DefineImplicitDefaultConstructor(Loc, Constructor);
}
ExprResult CurInit((Expr *)nullptr);
// C++ [over.match.copy]p1:
// - When initializing a temporary to be bound to the first parameter
// of a constructor that takes a reference to possibly cv-qualified
// T as its first argument, called with a single argument in the
// context of direct-initialization, explicit conversion functions
// are also considered.
bool AllowExplicitConv = Kind.AllowExplicit() && !Kind.isCopyInit() &&
Args.size() == 1 &&
Constructor->isCopyOrMoveConstructor();
// Determine the arguments required to actually perform the constructor
// call.
if (S.CompleteConstructorCall(Constructor, Args,
Loc, ConstructorArgs,
AllowExplicitConv,
IsListInitialization))
return ExprError();
if (isExplicitTemporary(Entity, Kind, NumArgs)) {
// An explicitly-constructed temporary, e.g., X(1, 2).
S.MarkFunctionReferenced(Loc, Constructor);
if (S.DiagnoseUseOfDecl(Constructor, Loc))
return ExprError();
TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo();
if (!TSInfo)
TSInfo = S.Context.getTrivialTypeSourceInfo(Entity.getType(), Loc);
SourceRange ParenOrBraceRange =
(Kind.getKind() == InitializationKind::IK_DirectList)
? SourceRange(LBraceLoc, RBraceLoc)
: Kind.getParenRange();
CurInit = new (S.Context) CXXTemporaryObjectExpr(
S.Context, Constructor, TSInfo, ConstructorArgs, ParenOrBraceRange,
HadMultipleCandidates, IsListInitialization,
IsStdInitListInitialization, ConstructorInitRequiresZeroInit);
} else {
CXXConstructExpr::ConstructionKind ConstructKind =
CXXConstructExpr::CK_Complete;
if (Entity.getKind() == InitializedEntity::EK_Base) {
ConstructKind = Entity.getBaseSpecifier()->isVirtual() ?
CXXConstructExpr::CK_VirtualBase :
CXXConstructExpr::CK_NonVirtualBase;
} else if (Entity.getKind() == InitializedEntity::EK_Delegating) {
ConstructKind = CXXConstructExpr::CK_Delegating;
}
// Only get the parenthesis or brace range if it is a list initialization or
// direct construction.
SourceRange ParenOrBraceRange;
if (IsListInitialization)
ParenOrBraceRange = SourceRange(LBraceLoc, RBraceLoc);
else if (Kind.getKind() == InitializationKind::IK_Direct)
ParenOrBraceRange = Kind.getParenRange();
// If the entity allows NRVO, mark the construction as elidable
// unconditionally.
if (Entity.allowsNRVO())
CurInit = S.BuildCXXConstructExpr(Loc, Entity.getType(),
Constructor, /*Elidable=*/true,
ConstructorArgs,
HadMultipleCandidates,
IsListInitialization,
IsStdInitListInitialization,
ConstructorInitRequiresZeroInit,
ConstructKind,
ParenOrBraceRange);
else
CurInit = S.BuildCXXConstructExpr(Loc, Entity.getType(),
Constructor,
ConstructorArgs,
HadMultipleCandidates,
IsListInitialization,
IsStdInitListInitialization,
ConstructorInitRequiresZeroInit,
ConstructKind,
ParenOrBraceRange);
}
if (CurInit.isInvalid())
return ExprError();
// Only check access if all of that succeeded.
S.CheckConstructorAccess(Loc, Constructor, Entity,
Step.Function.FoundDecl.getAccess());
if (S.DiagnoseUseOfDecl(Step.Function.FoundDecl, Loc))
return ExprError();
if (shouldBindAsTemporary(Entity))
CurInit = S.MaybeBindToTemporary(CurInit.get());
return CurInit;
}
/// Determine whether the specified InitializedEntity definitely has a lifetime
/// longer than the current full-expression. Conservatively returns false if
/// it's unclear.
static bool
InitializedEntityOutlivesFullExpression(const InitializedEntity &Entity) {
const InitializedEntity *Top = &Entity;
while (Top->getParent())
Top = Top->getParent();
switch (Top->getKind()) {
case InitializedEntity::EK_Variable:
case InitializedEntity::EK_Result:
case InitializedEntity::EK_Exception:
case InitializedEntity::EK_Member:
case InitializedEntity::EK_New:
case InitializedEntity::EK_Base:
case InitializedEntity::EK_Delegating:
return true;
case InitializedEntity::EK_ArrayElement:
case InitializedEntity::EK_VectorElement:
case InitializedEntity::EK_BlockElement:
case InitializedEntity::EK_ComplexElement:
// Could not determine what the full initialization is. Assume it might not
// outlive the full-expression.
return false;
case InitializedEntity::EK_Parameter:
case InitializedEntity::EK_Parameter_CF_Audited:
case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_LambdaCapture:
case InitializedEntity::EK_CompoundLiteralInit:
case InitializedEntity::EK_RelatedResult:
// The entity being initialized might not outlive the full-expression.
return false;
}
llvm_unreachable("unknown entity kind");
}
/// Determine the declaration which an initialized entity ultimately refers to,
/// for the purpose of lifetime-extending a temporary bound to a reference in
/// the initialization of \p Entity.
static const InitializedEntity *getEntityForTemporaryLifetimeExtension(
const InitializedEntity *Entity,
const InitializedEntity *FallbackDecl = nullptr) {
// C++11 [class.temporary]p5:
switch (Entity->getKind()) {
case InitializedEntity::EK_Variable:
// The temporary [...] persists for the lifetime of the reference
return Entity;
case InitializedEntity::EK_Member:
// For subobjects, we look at the complete object.
if (Entity->getParent())
return getEntityForTemporaryLifetimeExtension(Entity->getParent(),
Entity);
// except:
// -- A temporary bound to a reference member in a constructor's
// ctor-initializer persists until the constructor exits.
return Entity;
case InitializedEntity::EK_Parameter:
case InitializedEntity::EK_Parameter_CF_Audited:
// -- A temporary bound to a reference parameter in a function call
// persists until the completion of the full-expression containing
// the call.
case InitializedEntity::EK_Result:
// -- The lifetime of a temporary bound to the returned value in a
// function return statement is not extended; the temporary is
// destroyed at the end of the full-expression in the return statement.
case InitializedEntity::EK_New:
// -- A temporary bound to a reference in a new-initializer persists
// until the completion of the full-expression containing the
// new-initializer.
return nullptr;
case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_CompoundLiteralInit:
case InitializedEntity::EK_RelatedResult:
// We don't yet know the storage duration of the surrounding temporary.
// Assume it's got full-expression duration for now, it will patch up our
// storage duration if that's not correct.
return nullptr;
case InitializedEntity::EK_ArrayElement:
// For subobjects, we look at the complete object.
return getEntityForTemporaryLifetimeExtension(Entity->getParent(),
FallbackDecl);
case InitializedEntity::EK_Base:
case InitializedEntity::EK_Delegating:
// We can reach this case for aggregate initialization in a constructor:
// struct A { int &&r; };
// struct B : A { B() : A{0} {} };
// In this case, use the innermost field decl as the context.
return FallbackDecl;
case InitializedEntity::EK_BlockElement:
case InitializedEntity::EK_LambdaCapture:
case InitializedEntity::EK_Exception:
case InitializedEntity::EK_VectorElement:
case InitializedEntity::EK_ComplexElement:
return nullptr;
}
llvm_unreachable("unknown entity kind");
}
static void performLifetimeExtension(Expr *Init,
const InitializedEntity *ExtendingEntity);
/// Update a glvalue expression that is used as the initializer of a reference
/// to note that its lifetime is extended.
/// \return \c true if any temporary had its lifetime extended.
static bool
performReferenceExtension(Expr *Init,
const InitializedEntity *ExtendingEntity) {
if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
if (ILE->getNumInits() == 1 && ILE->isGLValue()) {
// This is just redundant braces around an initializer. Step over it.
Init = ILE->getInit(0);
}
}
// Walk past any constructs which we can lifetime-extend across.
Expr *Old;
do {
Old = Init;
// Step over any subobject adjustments; we may have a materialized
// temporary inside them.
SmallVector<const Expr *, 2> CommaLHSs;
SmallVector<SubobjectAdjustment, 2> Adjustments;
Init = const_cast<Expr *>(
Init->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments));
// Per current approach for DR1376, look through casts to reference type
// when performing lifetime extension.
if (CastExpr *CE = dyn_cast<CastExpr>(Init))
if (CE->getSubExpr()->isGLValue())
Init = CE->getSubExpr();
// FIXME: Per DR1213, subscripting on an array temporary produces an xvalue.
// It's unclear if binding a reference to that xvalue extends the array
// temporary.
} while (Init != Old);
if (MaterializeTemporaryExpr *ME = dyn_cast<MaterializeTemporaryExpr>(Init)) {
// Update the storage duration of the materialized temporary.
// FIXME: Rebuild the expression instead of mutating it.
ME->setExtendingDecl(ExtendingEntity->getDecl(),
ExtendingEntity->allocateManglingNumber());
performLifetimeExtension(ME->GetTemporaryExpr(), ExtendingEntity);
return true;
}
return false;
}
/// Update a prvalue expression that is going to be materialized as a
/// lifetime-extended temporary.
static void performLifetimeExtension(Expr *Init,
const InitializedEntity *ExtendingEntity) {
// Dig out the expression which constructs the extended temporary.
SmallVector<const Expr *, 2> CommaLHSs;
SmallVector<SubobjectAdjustment, 2> Adjustments;
Init = const_cast<Expr *>(
Init->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments));
if (CXXBindTemporaryExpr *BTE = dyn_cast<CXXBindTemporaryExpr>(Init))
Init = BTE->getSubExpr();
if (CXXStdInitializerListExpr *ILE =
dyn_cast<CXXStdInitializerListExpr>(Init)) {
performReferenceExtension(ILE->getSubExpr(), ExtendingEntity);
return;
}
if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
if (ILE->getType()->isArrayType()) {
for (unsigned I = 0, N = ILE->getNumInits(); I != N; ++I)
performLifetimeExtension(ILE->getInit(I), ExtendingEntity);
return;
}
if (CXXRecordDecl *RD = ILE->getType()->getAsCXXRecordDecl()) {
assert(RD->isAggregate() && "aggregate init on non-aggregate");
// If we lifetime-extend a braced initializer which is initializing an
// aggregate, and that aggregate contains reference members which are
// bound to temporaries, those temporaries are also lifetime-extended.
if (RD->isUnion() && ILE->getInitializedFieldInUnion() &&
ILE->getInitializedFieldInUnion()->getType()->isReferenceType())
performReferenceExtension(ILE->getInit(0), ExtendingEntity);
else {
unsigned Index = 0;
for (const auto *I : RD->fields()) {
if (Index >= ILE->getNumInits())
break;
if (I->isUnnamedBitfield())
continue;
Expr *SubInit = ILE->getInit(Index);
if (I->getType()->isReferenceType())
performReferenceExtension(SubInit, ExtendingEntity);
else if (isa<InitListExpr>(SubInit) ||
isa<CXXStdInitializerListExpr>(SubInit))
// This may be either aggregate-initialization of a member or
// initialization of a std::initializer_list object. Either way,
// we should recursively lifetime-extend that initializer.
performLifetimeExtension(SubInit, ExtendingEntity);
++Index;
}
}
}
}
}
static void warnOnLifetimeExtension(Sema &S, const InitializedEntity &Entity,
const Expr *Init, bool IsInitializerList,
const ValueDecl *ExtendingDecl) {
// Warn if a field lifetime-extends a temporary.
if (isa<FieldDecl>(ExtendingDecl)) {
if (IsInitializerList) {
S.Diag(Init->getExprLoc(), diag::warn_dangling_std_initializer_list)
<< /*at end of constructor*/true;
return;
}
bool IsSubobjectMember = false;
for (const InitializedEntity *Ent = Entity.getParent(); Ent;
Ent = Ent->getParent()) {
if (Ent->getKind() != InitializedEntity::EK_Base) {
IsSubobjectMember = true;
break;
}
}
S.Diag(Init->getExprLoc(),
diag::warn_bind_ref_member_to_temporary)
<< ExtendingDecl << Init->getSourceRange()
<< IsSubobjectMember << IsInitializerList;
if (IsSubobjectMember)
S.Diag(ExtendingDecl->getLocation(),
diag::note_ref_subobject_of_member_declared_here);
else
S.Diag(ExtendingDecl->getLocation(),
diag::note_ref_or_ptr_member_declared_here)
<< /*is pointer*/false;
}
}
static void DiagnoseNarrowingInInitList(Sema &S,
const ImplicitConversionSequence &ICS,
QualType PreNarrowingType,
QualType EntityType,
const Expr *PostInit);
ExprResult
InitializationSequence::Perform(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
MultiExprArg Args,
QualType *ResultType) {
if (Failed()) {
Diagnose(S, Entity, Kind, Args);
return ExprError();
}
if (getKind() == DependentSequence) {
// If the declaration is a non-dependent, incomplete array type
// that has an initializer, then its type will be completed once
// the initializer is instantiated.
if (ResultType && !Entity.getType()->isDependentType() &&
Args.size() == 1) {
QualType DeclType = Entity.getType();
if (const IncompleteArrayType *ArrayT
= S.Context.getAsIncompleteArrayType(DeclType)) {
// FIXME: We don't currently have the ability to accurately
// compute the length of an initializer list without
// performing full type-checking of the initializer list
// (since we have to determine where braces are implicitly
// introduced and such). So, we fall back to making the array
// type a dependently-sized array type with no specified
// bound.
if (isa<InitListExpr>((Expr *)Args[0])) {
SourceRange Brackets;
// Scavange the location of the brackets from the entity, if we can.
if (DeclaratorDecl *DD = Entity.getDecl()) {
if (TypeSourceInfo *TInfo = DD->getTypeSourceInfo()) {
TypeLoc TL = TInfo->getTypeLoc();
if (IncompleteArrayTypeLoc ArrayLoc =
TL.getAs<IncompleteArrayTypeLoc>())
Brackets = ArrayLoc.getBracketsRange();
}
}
*ResultType
= S.Context.getDependentSizedArrayType(ArrayT->getElementType(),
/*NumElts=*/nullptr,
ArrayT->getSizeModifier(),
ArrayT->getIndexTypeCVRQualifiers(),
Brackets);
}
}
}
if (Kind.getKind() == InitializationKind::IK_Direct &&
!Kind.isExplicitCast()) {
// Rebuild the ParenListExpr.
SourceRange ParenRange = Kind.getParenRange();
return S.ActOnParenListExpr(ParenRange.getBegin(), ParenRange.getEnd(),
Args);
}
assert(Kind.getKind() == InitializationKind::IK_Copy ||
Kind.isExplicitCast() ||
Kind.getKind() == InitializationKind::IK_DirectList);
return ExprResult(Args[0]);
}
// No steps means no initialization.
if (Steps.empty())
return ExprResult((Expr *)nullptr);
if (S.getLangOpts().CPlusPlus11 && Entity.getType()->isReferenceType() &&
Args.size() == 1 && isa<InitListExpr>(Args[0]) &&
!Entity.isParameterKind()) {
// Produce a C++98 compatibility warning if we are initializing a reference
// from an initializer list. For parameters, we produce a better warning
// elsewhere.
Expr *Init = Args[0];
S.Diag(Init->getLocStart(), diag::warn_cxx98_compat_reference_list_init)
<< Init->getSourceRange();
}
// Diagnose cases where we initialize a pointer to an array temporary, and the
// pointer obviously outlives the temporary.
if (Args.size() == 1 && Args[0]->getType()->isArrayType() &&
Entity.getType()->isPointerType() &&
InitializedEntityOutlivesFullExpression(Entity)) {
Expr *Init = Args[0];
Expr::LValueClassification Kind = Init->ClassifyLValue(S.Context);
if (Kind == Expr::LV_ClassTemporary || Kind == Expr::LV_ArrayTemporary)
S.Diag(Init->getLocStart(), diag::warn_temporary_array_to_pointer_decay)
<< Init->getSourceRange();
}
QualType DestType = Entity.getType().getNonReferenceType();
// FIXME: Ugly hack around the fact that Entity.getType() is not
// the same as Entity.getDecl()->getType() in cases involving type merging,
// and we want latter when it makes sense.
if (ResultType)
*ResultType = Entity.getDecl() ? Entity.getDecl()->getType() :
Entity.getType();
ExprResult CurInit((Expr *)nullptr);
// For initialization steps that start with a single initializer,
// grab the only argument out the Args and place it into the "current"
// initializer.
switch (Steps.front().Kind) {
case SK_ResolveAddressOfOverloadedFunction:
case SK_CastDerivedToBaseRValue:
case SK_CastDerivedToBaseXValue:
case SK_CastDerivedToBaseLValue:
case SK_BindReference:
case SK_BindReferenceToTemporary:
case SK_ExtraneousCopyToTemporary:
case SK_UserConversion:
case SK_QualificationConversionLValue:
case SK_QualificationConversionXValue:
case SK_QualificationConversionRValue:
case SK_AtomicConversion:
case SK_LValueToRValue:
case SK_ConversionSequence:
case SK_ConversionSequenceNoNarrowing:
case SK_ListInitialization:
case SK_UnwrapInitList:
case SK_RewrapInitList:
case SK_CAssignment:
case SK_StringInit:
case SK_ObjCObjectConversion:
case SK_ArrayInit:
case SK_ParenthesizedArrayInit:
case SK_PassByIndirectCopyRestore:
case SK_PassByIndirectRestore:
case SK_ProduceObjCObject:
case SK_StdInitializerList:
case SK_OCLSamplerInit:
case SK_OCLZeroEvent: {
assert(Args.size() == 1);
CurInit = Args[0];
if (!CurInit.get()) return ExprError();
break;
}
case SK_ConstructorInitialization:
case SK_ConstructorInitializationFromList:
case SK_StdInitializerListConstructorCall:
case SK_ZeroInitialization:
break;
}
// Walk through the computed steps for the initialization sequence,
// performing the specified conversions along the way.
bool ConstructorInitRequiresZeroInit = false;
for (step_iterator Step = step_begin(), StepEnd = step_end();
Step != StepEnd; ++Step) {
if (CurInit.isInvalid())
return ExprError();
QualType SourceType = CurInit.get() ? CurInit.get()->getType() : QualType();
switch (Step->Kind) {
case SK_ResolveAddressOfOverloadedFunction:
// Overload resolution determined which function invoke; update the
// initializer to reflect that choice.
S.CheckAddressOfMemberAccess(CurInit.get(), Step->Function.FoundDecl);
if (S.DiagnoseUseOfDecl(Step->Function.FoundDecl, Kind.getLocation()))
return ExprError();
CurInit = S.FixOverloadedFunctionReference(CurInit,
Step->Function.FoundDecl,
Step->Function.Function);
break;
case SK_CastDerivedToBaseRValue:
case SK_CastDerivedToBaseXValue:
case SK_CastDerivedToBaseLValue: {
// We have a derived-to-base cast that produces either an rvalue or an
// lvalue. Perform that cast.
CXXCastPath BasePath;
// Casts to inaccessible base classes are allowed with C-style casts.
bool IgnoreBaseAccess = Kind.isCStyleOrFunctionalCast();
if (S.CheckDerivedToBaseConversion(SourceType, Step->Type,
CurInit.get()->getLocStart(),
CurInit.get()->getSourceRange(),
&BasePath, IgnoreBaseAccess))
return ExprError();
if (S.BasePathInvolvesVirtualBase(BasePath)) {
QualType T = SourceType;
if (const PointerType *Pointer = T->getAs<PointerType>())
T = Pointer->getPointeeType();
if (const RecordType *RecordTy = T->getAs<RecordType>())
S.MarkVTableUsed(CurInit.get()->getLocStart(),
cast<CXXRecordDecl>(RecordTy->getDecl()));
}
ExprValueKind VK =
Step->Kind == SK_CastDerivedToBaseLValue ?
VK_LValue :
(Step->Kind == SK_CastDerivedToBaseXValue ?
VK_XValue :
VK_RValue);
CurInit =
ImplicitCastExpr::Create(S.Context, Step->Type, CK_DerivedToBase,
CurInit.get(), &BasePath, VK);
break;
}
case SK_BindReference:
// References cannot bind to bit-fields (C++ [dcl.init.ref]p5).
if (CurInit.get()->refersToBitField()) {
// We don't necessarily have an unambiguous source bit-field.
FieldDecl *BitField = CurInit.get()->getSourceBitField();
S.Diag(Kind.getLocation(), diag::err_reference_bind_to_bitfield)
<< Entity.getType().isVolatileQualified()
<< (BitField ? BitField->getDeclName() : DeclarationName())
<< (BitField != nullptr)
<< CurInit.get()->getSourceRange();
if (BitField)
S.Diag(BitField->getLocation(), diag::note_bitfield_decl);
return ExprError();
}
if (CurInit.get()->refersToVectorElement()) {
// References cannot bind to vector elements.
S.Diag(Kind.getLocation(), diag::err_reference_bind_to_vector_element)
<< Entity.getType().isVolatileQualified()
<< CurInit.get()->getSourceRange();
PrintInitLocationNote(S, Entity);
return ExprError();
}
// Reference binding does not have any corresponding ASTs.
// Check exception specifications
if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType))
return ExprError();
// Even though we didn't materialize a temporary, the binding may still
// extend the lifetime of a temporary. This happens if we bind a reference
// to the result of a cast to reference type.
if (const InitializedEntity *ExtendingEntity =
getEntityForTemporaryLifetimeExtension(&Entity))
if (performReferenceExtension(CurInit.get(), ExtendingEntity))
warnOnLifetimeExtension(S, Entity, CurInit.get(),
/*IsInitializerList=*/false,
ExtendingEntity->getDecl());
break;
case SK_BindReferenceToTemporary: {
// Make sure the "temporary" is actually an rvalue.
assert(CurInit.get()->isRValue() && "not a temporary");
// Check exception specifications
if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType))
return ExprError();
// Materialize the temporary into memory.
MaterializeTemporaryExpr *MTE = new (S.Context) MaterializeTemporaryExpr(
Entity.getType().getNonReferenceType(), CurInit.get(),
Entity.getType()->isLValueReferenceType());
// Maybe lifetime-extend the temporary's subobjects to match the
// entity's lifetime.
if (const InitializedEntity *ExtendingEntity =
getEntityForTemporaryLifetimeExtension(&Entity))
if (performReferenceExtension(MTE, ExtendingEntity))
warnOnLifetimeExtension(S, Entity, CurInit.get(), /*IsInitializerList=*/false,
ExtendingEntity->getDecl());
// If we're binding to an Objective-C object that has lifetime, we
// need cleanups. Likewise if we're extending this temporary to automatic
// storage duration -- we need to register its cleanup during the
// full-expression's cleanups.
if ((S.getLangOpts().ObjCAutoRefCount &&
MTE->getType()->isObjCLifetimeType()) ||
(MTE->getStorageDuration() == SD_Automatic &&
MTE->getType().isDestructedType()))
S.ExprNeedsCleanups = true;
CurInit = MTE;
break;
}
case SK_ExtraneousCopyToTemporary:
CurInit = CopyObject(S, Step->Type, Entity, CurInit,
/*IsExtraneousCopy=*/true);
break;
case SK_UserConversion: {
// We have a user-defined conversion that invokes either a constructor
// or a conversion function.
CastKind CastKind;
bool IsCopy = false;
FunctionDecl *Fn = Step->Function.Function;
DeclAccessPair FoundFn = Step->Function.FoundDecl;
bool HadMultipleCandidates = Step->Function.HadMultipleCandidates;
bool CreatedObject = false;
if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Fn)) {
// Build a call to the selected constructor.
SmallVector<Expr*, 8> ConstructorArgs;
SourceLocation Loc = CurInit.get()->getLocStart();
CurInit.get(); // Ownership transferred into MultiExprArg, below.
// Determine the arguments required to actually perform the constructor
// call.
Expr *Arg = CurInit.get();
if (S.CompleteConstructorCall(Constructor,
MultiExprArg(&Arg, 1),
Loc, ConstructorArgs))
return ExprError();
// Build an expression that constructs a temporary.
CurInit = S.BuildCXXConstructExpr(Loc, Step->Type, Constructor,
ConstructorArgs,
HadMultipleCandidates,
/*ListInit*/ false,
/*StdInitListInit*/ false,
/*ZeroInit*/ false,
CXXConstructExpr::CK_Complete,
SourceRange());
if (CurInit.isInvalid())
return ExprError();
S.CheckConstructorAccess(Kind.getLocation(), Constructor, Entity,
FoundFn.getAccess());
if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation()))
return ExprError();
CastKind = CK_ConstructorConversion;
QualType Class = S.Context.getTypeDeclType(Constructor->getParent());
if (S.Context.hasSameUnqualifiedType(SourceType, Class) ||
S.IsDerivedFrom(SourceType, Class))
IsCopy = true;
CreatedObject = true;
} else {
// Build a call to the conversion function.
CXXConversionDecl *Conversion = cast<CXXConversionDecl>(Fn);
S.CheckMemberOperatorAccess(Kind.getLocation(), CurInit.get(), nullptr,
FoundFn);
if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation()))
return ExprError();
// FIXME: Should we move this initialization into a separate
// derived-to-base conversion? I believe the answer is "no", because
// we don't want to turn off access control here for c-style casts.
ExprResult CurInitExprRes =
S.PerformObjectArgumentInitialization(CurInit.get(),
/*Qualifier=*/nullptr,
FoundFn, Conversion);
if(CurInitExprRes.isInvalid())
return ExprError();
CurInit = CurInitExprRes;
// Build the actual call to the conversion function.
CurInit = S.BuildCXXMemberCallExpr(CurInit.get(), FoundFn, Conversion,
HadMultipleCandidates);
if (CurInit.isInvalid() || !CurInit.get())
return ExprError();
CastKind = CK_UserDefinedConversion;
CreatedObject = Conversion->getReturnType()->isRecordType();
}
bool RequiresCopy = !IsCopy && !isReferenceBinding(Steps.back());
bool MaybeBindToTemp = RequiresCopy || shouldBindAsTemporary(Entity);
if (!MaybeBindToTemp && CreatedObject && shouldDestroyTemporary(Entity)) {
QualType T = CurInit.get()->getType();
if (const RecordType *Record = T->getAs<RecordType>()) {
CXXDestructorDecl *Destructor
= S.LookupDestructor(cast<CXXRecordDecl>(Record->getDecl()));
S.CheckDestructorAccess(CurInit.get()->getLocStart(), Destructor,
S.PDiag(diag::err_access_dtor_temp) << T);
S.MarkFunctionReferenced(CurInit.get()->getLocStart(), Destructor);
if (S.DiagnoseUseOfDecl(Destructor, CurInit.get()->getLocStart()))
return ExprError();
}
}
CurInit = ImplicitCastExpr::Create(S.Context, CurInit.get()->getType(),
CastKind, CurInit.get(), nullptr,
CurInit.get()->getValueKind());
if (MaybeBindToTemp)
CurInit = S.MaybeBindToTemporary(CurInit.getAs<Expr>());
if (RequiresCopy)
CurInit = CopyObject(S, Entity.getType().getNonReferenceType(), Entity,
CurInit, /*IsExtraneousCopy=*/false);
break;
}
case SK_QualificationConversionLValue:
case SK_QualificationConversionXValue:
case SK_QualificationConversionRValue: {
// Perform a qualification conversion; these can never go wrong.
ExprValueKind VK =
Step->Kind == SK_QualificationConversionLValue ?
VK_LValue :
(Step->Kind == SK_QualificationConversionXValue ?
VK_XValue :
VK_RValue);
CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type, CK_NoOp, VK);
break;
}
case SK_AtomicConversion: {
assert(CurInit.get()->isRValue() && "cannot convert glvalue to atomic");
CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
CK_NonAtomicToAtomic, VK_RValue);
break;
}
case SK_LValueToRValue: {
assert(CurInit.get()->isGLValue() && "cannot load from a prvalue");
CurInit = ImplicitCastExpr::Create(S.Context, Step->Type,
CK_LValueToRValue, CurInit.get(),
/*BasePath=*/nullptr, VK_RValue);
break;
}
case SK_ConversionSequence:
case SK_ConversionSequenceNoNarrowing: {
Sema::CheckedConversionKind CCK
= Kind.isCStyleCast()? Sema::CCK_CStyleCast
: Kind.isFunctionalCast()? Sema::CCK_FunctionalCast
: Kind.isExplicitCast()? Sema::CCK_OtherCast
: Sema::CCK_ImplicitConversion;
ExprResult CurInitExprRes =
S.PerformImplicitConversion(CurInit.get(), Step->Type, *Step->ICS,
getAssignmentAction(Entity), CCK);
if (CurInitExprRes.isInvalid())
return ExprError();
CurInit = CurInitExprRes;
if (Step->Kind == SK_ConversionSequenceNoNarrowing &&
S.getLangOpts().CPlusPlus && !CurInit.get()->isValueDependent())
DiagnoseNarrowingInInitList(S, *Step->ICS, SourceType, Entity.getType(),
CurInit.get());
break;
}
case SK_ListInitialization: {
InitListExpr *InitList = cast<InitListExpr>(CurInit.get());
// If we're not initializing the top-level entity, we need to create an
// InitializeTemporary entity for our target type.
QualType Ty = Step->Type;
bool IsTemporary = !S.Context.hasSameType(Entity.getType(), Ty);
InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(Ty);
InitializedEntity InitEntity = IsTemporary ? TempEntity : Entity;
InitListChecker PerformInitList(S, InitEntity,
InitList, Ty, /*VerifyOnly=*/false);
if (PerformInitList.HadError())
return ExprError();
// Hack: We must update *ResultType if available in order to set the
// bounds of arrays, e.g. in 'int ar[] = {1, 2, 3};'.
// Worst case: 'const int (&arref)[] = {1, 2, 3};'.
if (ResultType &&
ResultType->getNonReferenceType()->isIncompleteArrayType()) {
if ((*ResultType)->isRValueReferenceType())
Ty = S.Context.getRValueReferenceType(Ty);
else if ((*ResultType)->isLValueReferenceType())
Ty = S.Context.getLValueReferenceType(Ty,
(*ResultType)->getAs<LValueReferenceType>()->isSpelledAsLValue());
*ResultType = Ty;
}
InitListExpr *StructuredInitList =
PerformInitList.getFullyStructuredList();
CurInit.get();
CurInit = shouldBindAsTemporary(InitEntity)
? S.MaybeBindToTemporary(StructuredInitList)
: StructuredInitList;
break;
}
case SK_ConstructorInitializationFromList: {
// When an initializer list is passed for a parameter of type "reference
// to object", we don't get an EK_Temporary entity, but instead an
// EK_Parameter entity with reference type.
// FIXME: This is a hack. What we really should do is create a user
// conversion step for this case, but this makes it considerably more
// complicated. For now, this will do.
InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(
Entity.getType().getNonReferenceType());
bool UseTemporary = Entity.getType()->isReferenceType();
assert(Args.size() == 1 && "expected a single argument for list init");
InitListExpr *InitList = cast<InitListExpr>(Args[0]);
S.Diag(InitList->getExprLoc(), diag::warn_cxx98_compat_ctor_list_init)
<< InitList->getSourceRange();
MultiExprArg Arg(InitList->getInits(), InitList->getNumInits());
CurInit = PerformConstructorInitialization(S, UseTemporary ? TempEntity :
Entity,
Kind, Arg, *Step,
ConstructorInitRequiresZeroInit,
/*IsListInitialization*/true,
/*IsStdInitListInit*/false,
InitList->getLBraceLoc(),
InitList->getRBraceLoc());
break;
}
case SK_UnwrapInitList:
CurInit = cast<InitListExpr>(CurInit.get())->getInit(0);
break;
case SK_RewrapInitList: {
Expr *E = CurInit.get();
InitListExpr *Syntactic = Step->WrappingSyntacticList;
InitListExpr *ILE = new (S.Context) InitListExpr(S.Context,
Syntactic->getLBraceLoc(), E, Syntactic->getRBraceLoc());
ILE->setSyntacticForm(Syntactic);
ILE->setType(E->getType());
ILE->setValueKind(E->getValueKind());
CurInit = ILE;
break;
}
case SK_ConstructorInitialization:
case SK_StdInitializerListConstructorCall: {
// When an initializer list is passed for a parameter of type "reference
// to object", we don't get an EK_Temporary entity, but instead an
// EK_Parameter entity with reference type.
// FIXME: This is a hack. What we really should do is create a user
// conversion step for this case, but this makes it considerably more
// complicated. For now, this will do.
InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(
Entity.getType().getNonReferenceType());
bool UseTemporary = Entity.getType()->isReferenceType();
bool IsStdInitListInit =
Step->Kind == SK_StdInitializerListConstructorCall;
CurInit = PerformConstructorInitialization(
S, UseTemporary ? TempEntity : Entity, Kind, Args, *Step,
ConstructorInitRequiresZeroInit,
/*IsListInitialization*/IsStdInitListInit,
/*IsStdInitListInitialization*/IsStdInitListInit,
/*LBraceLoc*/SourceLocation(),
/*RBraceLoc*/SourceLocation());
break;
}
case SK_ZeroInitialization: {
step_iterator NextStep = Step;
++NextStep;
if (NextStep != StepEnd &&
(NextStep->Kind == SK_ConstructorInitialization ||
NextStep->Kind == SK_ConstructorInitializationFromList)) {
// The need for zero-initialization is recorded directly into
// the call to the object's constructor within the next step.
ConstructorInitRequiresZeroInit = true;
} else if (Kind.getKind() == InitializationKind::IK_Value &&
S.getLangOpts().CPlusPlus &&
!Kind.isImplicitValueInit()) {
TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo();
if (!TSInfo)
TSInfo = S.Context.getTrivialTypeSourceInfo(Step->Type,
Kind.getRange().getBegin());
CurInit = new (S.Context) CXXScalarValueInitExpr(
TSInfo->getType().getNonLValueExprType(S.Context), TSInfo,
Kind.getRange().getEnd());
} else {
CurInit = new (S.Context) ImplicitValueInitExpr(Step->Type);
}
break;
}
case SK_CAssignment: {
QualType SourceType = CurInit.get()->getType();
ExprResult Result = CurInit;
Sema::AssignConvertType ConvTy =
S.CheckSingleAssignmentConstraints(Step->Type, Result, true,
Entity.getKind() == InitializedEntity::EK_Parameter_CF_Audited);
if (Result.isInvalid())
return ExprError();
CurInit = Result;
// If this is a call, allow conversion to a transparent union.
ExprResult CurInitExprRes = CurInit;
if (ConvTy != Sema::Compatible &&
Entity.isParameterKind() &&
S.CheckTransparentUnionArgumentConstraints(Step->Type, CurInitExprRes)
== Sema::Compatible)
ConvTy = Sema::Compatible;
if (CurInitExprRes.isInvalid())
return ExprError();
CurInit = CurInitExprRes;
bool Complained;
if (S.DiagnoseAssignmentResult(ConvTy, Kind.getLocation(),
Step->Type, SourceType,
CurInit.get(),
getAssignmentAction(Entity, true),
&Complained)) {
PrintInitLocationNote(S, Entity);
return ExprError();
} else if (Complained)
PrintInitLocationNote(S, Entity);
break;
}
case SK_StringInit: {
QualType Ty = Step->Type;
CheckStringInit(CurInit.get(), ResultType ? *ResultType : Ty,
S.Context.getAsArrayType(Ty), S);
break;
}
case SK_ObjCObjectConversion:
CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
CK_ObjCObjectLValueCast,
CurInit.get()->getValueKind());
break;
case SK_ArrayInit:
// Okay: we checked everything before creating this step. Note that
// this is a GNU extension.
S.Diag(Kind.getLocation(), diag::ext_array_init_copy)
<< Step->Type << CurInit.get()->getType()
<< CurInit.get()->getSourceRange();
// If the destination type is an incomplete array type, update the
// type accordingly.
if (ResultType) {
if (const IncompleteArrayType *IncompleteDest
= S.Context.getAsIncompleteArrayType(Step->Type)) {
if (const ConstantArrayType *ConstantSource
= S.Context.getAsConstantArrayType(CurInit.get()->getType())) {
*ResultType = S.Context.getConstantArrayType(
IncompleteDest->getElementType(),
ConstantSource->getSize(),
ArrayType::Normal, 0);
}
}
}
break;
case SK_ParenthesizedArrayInit:
// Okay: we checked everything before creating this step. Note that
// this is a GNU extension.
S.Diag(Kind.getLocation(), diag::ext_array_init_parens)
<< CurInit.get()->getSourceRange();
break;
case SK_PassByIndirectCopyRestore:
case SK_PassByIndirectRestore:
checkIndirectCopyRestoreSource(S, CurInit.get());
CurInit = new (S.Context) ObjCIndirectCopyRestoreExpr(
CurInit.get(), Step->Type,
Step->Kind == SK_PassByIndirectCopyRestore);
break;
case SK_ProduceObjCObject:
CurInit =
ImplicitCastExpr::Create(S.Context, Step->Type, CK_ARCProduceObject,
CurInit.get(), nullptr, VK_RValue);
break;
case SK_StdInitializerList: {
S.Diag(CurInit.get()->getExprLoc(),
diag::warn_cxx98_compat_initializer_list_init)
<< CurInit.get()->getSourceRange();
// Materialize the temporary into memory.
MaterializeTemporaryExpr *MTE = new (S.Context)
MaterializeTemporaryExpr(CurInit.get()->getType(), CurInit.get(),
/*BoundToLvalueReference=*/false);
// Maybe lifetime-extend the array temporary's subobjects to match the
// entity's lifetime.
if (const InitializedEntity *ExtendingEntity =
getEntityForTemporaryLifetimeExtension(&Entity))
if (performReferenceExtension(MTE, ExtendingEntity))
warnOnLifetimeExtension(S, Entity, CurInit.get(),
/*IsInitializerList=*/true,
ExtendingEntity->getDecl());
// Wrap it in a construction of a std::initializer_list<T>.
CurInit = new (S.Context) CXXStdInitializerListExpr(Step->Type, MTE);
// Bind the result, in case the library has given initializer_list a
// non-trivial destructor.
if (shouldBindAsTemporary(Entity))
CurInit = S.MaybeBindToTemporary(CurInit.get());
break;
}
case SK_OCLSamplerInit: {
assert(Step->Type->isSamplerT() &&
"Sampler initialization on non-sampler type.");
QualType SourceType = CurInit.get()->getType();
if (Entity.isParameterKind()) {
if (!SourceType->isSamplerT())
S.Diag(Kind.getLocation(), diag::err_sampler_argument_required)
<< SourceType;
} else if (Entity.getKind() != InitializedEntity::EK_Variable) {
llvm_unreachable("Invalid EntityKind!");
}
break;
}
case SK_OCLZeroEvent: {
assert(Step->Type->isEventT() &&
"Event initialization on non-event type.");
CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
CK_ZeroToOCLEvent,
CurInit.get()->getValueKind());
break;
}
}
}
// Diagnose non-fatal problems with the completed initialization.
if (Entity.getKind() == InitializedEntity::EK_Member &&
cast<FieldDecl>(Entity.getDecl())->isBitField())
S.CheckBitFieldInitialization(Kind.getLocation(),
cast<FieldDecl>(Entity.getDecl()),
CurInit.get());
return CurInit;
}
/// Somewhere within T there is an uninitialized reference subobject.
/// Dig it out and diagnose it.
static bool DiagnoseUninitializedReference(Sema &S, SourceLocation Loc,
QualType T) {
if (T->isReferenceType()) {
S.Diag(Loc, diag::err_reference_without_init)
<< T.getNonReferenceType();
return true;
}
CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
if (!RD || !RD->hasUninitializedReferenceMember())
return false;
for (const auto *FI : RD->fields()) {
if (FI->isUnnamedBitfield())
continue;
if (DiagnoseUninitializedReference(S, FI->getLocation(), FI->getType())) {
S.Diag(Loc, diag::note_value_initialization_here) << RD;
return true;
}
}
for (const auto &BI : RD->bases()) {
if (DiagnoseUninitializedReference(S, BI.getLocStart(), BI.getType())) {
S.Diag(Loc, diag::note_value_initialization_here) << RD;
return true;
}
}
return false;
}
//===----------------------------------------------------------------------===//
// Diagnose initialization failures
//===----------------------------------------------------------------------===//
/// Emit notes associated with an initialization that failed due to a
/// "simple" conversion failure.
static void emitBadConversionNotes(Sema &S, const InitializedEntity &entity,
Expr *op) {
QualType destType = entity.getType();
if (destType.getNonReferenceType()->isObjCObjectPointerType() &&
op->getType()->isObjCObjectPointerType()) {
// Emit a possible note about the conversion failing because the
// operand is a message send with a related result type.
S.EmitRelatedResultTypeNote(op);
// Emit a possible note about a return failing because we're
// expecting a related result type.
if (entity.getKind() == InitializedEntity::EK_Result)
S.EmitRelatedResultTypeNoteForReturn(destType);
}
}
static void diagnoseListInit(Sema &S, const InitializedEntity &Entity,
InitListExpr *InitList) {
QualType DestType = Entity.getType();
QualType E;
if (S.getLangOpts().CPlusPlus11 && S.isStdInitializerList(DestType, &E)) {
QualType ArrayType = S.Context.getConstantArrayType(
E.withConst(),
llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
InitList->getNumInits()),
clang::ArrayType::Normal, 0);
InitializedEntity HiddenArray =
InitializedEntity::InitializeTemporary(ArrayType);
return diagnoseListInit(S, HiddenArray, InitList);
}
if (DestType->isReferenceType()) {
// A list-initialization failure for a reference means that we tried to
// create a temporary of the inner type (per [dcl.init.list]p3.6) and the
// inner initialization failed.
QualType T = DestType->getAs<ReferenceType>()->getPointeeType();
diagnoseListInit(S, InitializedEntity::InitializeTemporary(T), InitList);
SourceLocation Loc = InitList->getLocStart();
if (auto *D = Entity.getDecl())
Loc = D->getLocation();
S.Diag(Loc, diag::note_in_reference_temporary_list_initializer) << T;
return;
}
InitListChecker DiagnoseInitList(S, Entity, InitList, DestType,
/*VerifyOnly=*/false);
assert(DiagnoseInitList.HadError() &&
"Inconsistent init list check result.");
}
/// Prints a fixit for adding a null initializer for |Entity|. Call this only
/// right after emitting a diagnostic.
static void maybeEmitZeroInitializationFixit(Sema &S,
InitializationSequence &Sequence,
const InitializedEntity &Entity) {
if (Entity.getKind() != InitializedEntity::EK_Variable)
return;
VarDecl *VD = cast<VarDecl>(Entity.getDecl());
if (VD->getInit() || VD->getLocEnd().isMacroID())
return;
QualType VariableTy = VD->getType().getCanonicalType();
SourceLocation Loc = S.getLocForEndOfToken(VD->getLocEnd());
std::string Init = S.getFixItZeroInitializerForType(VariableTy, Loc);
S.Diag(Loc, diag::note_add_initializer)
<< VD << FixItHint::CreateInsertion(Loc, Init);
}
bool InitializationSequence::Diagnose(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
ArrayRef<Expr *> Args) {
if (!Failed())
return false;
QualType DestType = Entity.getType();
switch (Failure) {
case FK_TooManyInitsForReference:
// FIXME: Customize for the initialized entity?
if (Args.empty()) {
// Dig out the reference subobject which is uninitialized and diagnose it.
// If this is value-initialization, this could be nested some way within
// the target type.
assert(Kind.getKind() == InitializationKind::IK_Value ||
DestType->isReferenceType());
bool Diagnosed =
DiagnoseUninitializedReference(S, Kind.getLocation(), DestType);
assert(Diagnosed && "couldn't find uninitialized reference to diagnose");
(void)Diagnosed;
} else // FIXME: diagnostic below could be better!
S.Diag(Kind.getLocation(), diag::err_reference_has_multiple_inits)
<< SourceRange(Args.front()->getLocStart(), Args.back()->getLocEnd());
break;
case FK_ArrayNeedsInitList:
S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 0;
break;
case FK_ArrayNeedsInitListOrStringLiteral:
S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 1;
break;
case FK_ArrayNeedsInitListOrWideStringLiteral:
S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 2;
break;
case FK_NarrowStringIntoWideCharArray:
S.Diag(Kind.getLocation(), diag::err_array_init_narrow_string_into_wchar);
break;
case FK_WideStringIntoCharArray:
S.Diag(Kind.getLocation(), diag::err_array_init_wide_string_into_char);
break;
case FK_IncompatWideStringIntoWideChar:
S.Diag(Kind.getLocation(),
diag::err_array_init_incompat_wide_string_into_wchar);
break;
case FK_ArrayTypeMismatch:
case FK_NonConstantArrayInit:
S.Diag(Kind.getLocation(),
(Failure == FK_ArrayTypeMismatch
? diag::err_array_init_different_type
: diag::err_array_init_non_constant_array))
<< DestType.getNonReferenceType()
<< Args[0]->getType()
<< Args[0]->getSourceRange();
break;
case FK_VariableLengthArrayHasInitializer:
S.Diag(Kind.getLocation(), diag::err_variable_object_no_init)
<< Args[0]->getSourceRange();
break;
case FK_AddressOfOverloadFailed: {
DeclAccessPair Found;
S.ResolveAddressOfOverloadedFunction(Args[0],
DestType.getNonReferenceType(),
true,
Found);
break;
}
case FK_ReferenceInitOverloadFailed:
case FK_UserConversionOverloadFailed:
switch (FailedOverloadResult) {
case OR_Ambiguous:
if (Failure == FK_UserConversionOverloadFailed)
S.Diag(Kind.getLocation(), diag::err_typecheck_ambiguous_condition)
<< Args[0]->getType() << DestType
<< Args[0]->getSourceRange();
else
S.Diag(Kind.getLocation(), diag::err_ref_init_ambiguous)
<< DestType << Args[0]->getType()
<< Args[0]->getSourceRange();
FailedCandidateSet.NoteCandidates(S, OCD_ViableCandidates, Args);
break;
case OR_No_Viable_Function:
if (!S.RequireCompleteType(Kind.getLocation(),
DestType.getNonReferenceType(),
diag::err_typecheck_nonviable_condition_incomplete,
Args[0]->getType(), Args[0]->getSourceRange()))
S.Diag(Kind.getLocation(), diag::err_typecheck_nonviable_condition)
<< Args[0]->getType() << Args[0]->getSourceRange()
<< DestType.getNonReferenceType();
FailedCandidateSet.NoteCandidates(S, OCD_AllCandidates, Args);
break;
case OR_Deleted: {
S.Diag(Kind.getLocation(), diag::err_typecheck_deleted_function)
<< Args[0]->getType() << DestType.getNonReferenceType()
<< Args[0]->getSourceRange();
OverloadCandidateSet::iterator Best;
OverloadingResult Ovl
= FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best,
true);
if (Ovl == OR_Deleted) {
S.NoteDeletedFunction(Best->Function);
} else {
llvm_unreachable("Inconsistent overload resolution?");
}
break;
}
case OR_Success:
llvm_unreachable("Conversion did not fail!");
}
break;
case FK_NonConstLValueReferenceBindingToTemporary:
if (isa<InitListExpr>(Args[0])) {
S.Diag(Kind.getLocation(),
diag::err_lvalue_reference_bind_to_initlist)
<< DestType.getNonReferenceType().isVolatileQualified()
<< DestType.getNonReferenceType()
<< Args[0]->getSourceRange();
break;
}
// Intentional fallthrough
case FK_NonConstLValueReferenceBindingToUnrelated:
S.Diag(Kind.getLocation(),
Failure == FK_NonConstLValueReferenceBindingToTemporary
? diag::err_lvalue_reference_bind_to_temporary
: diag::err_lvalue_reference_bind_to_unrelated)
<< DestType.getNonReferenceType().isVolatileQualified()
<< DestType.getNonReferenceType()
<< Args[0]->getType()
<< Args[0]->getSourceRange();
break;
case FK_RValueReferenceBindingToLValue:
S.Diag(Kind.getLocation(), diag::err_lvalue_to_rvalue_ref)
<< DestType.getNonReferenceType() << Args[0]->getType()
<< Args[0]->getSourceRange();
break;
case FK_ReferenceInitDropsQualifiers:
S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
<< DestType.getNonReferenceType()
<< Args[0]->getType()
<< Args[0]->getSourceRange();
break;
case FK_ReferenceInitFailed:
S.Diag(Kind.getLocation(), diag::err_reference_bind_failed)
<< DestType.getNonReferenceType()
<< Args[0]->isLValue()
<< Args[0]->getType()
<< Args[0]->getSourceRange();
emitBadConversionNotes(S, Entity, Args[0]);
break;
case FK_ConversionFailed: {
QualType FromType = Args[0]->getType();
PartialDiagnostic PDiag = S.PDiag(diag::err_init_conversion_failed)
<< (int)Entity.getKind()
<< DestType
<< Args[0]->isLValue()
<< FromType
<< Args[0]->getSourceRange();
S.HandleFunctionTypeMismatch(PDiag, FromType, DestType);
S.Diag(Kind.getLocation(), PDiag);
emitBadConversionNotes(S, Entity, Args[0]);
break;
}
case FK_ConversionFromPropertyFailed:
// No-op. This error has already been reported.
break;
case FK_TooManyInitsForScalar: {
SourceRange R;
if (InitListExpr *InitList = dyn_cast<InitListExpr>(Args[0]))
R = SourceRange(InitList->getInit(0)->getLocEnd(),
InitList->getLocEnd());
else
R = SourceRange(Args.front()->getLocEnd(), Args.back()->getLocEnd());
R.setBegin(S.getLocForEndOfToken(R.getBegin()));
if (Kind.isCStyleOrFunctionalCast())
S.Diag(Kind.getLocation(), diag::err_builtin_func_cast_more_than_one_arg)
<< R;
else
S.Diag(Kind.getLocation(), diag::err_excess_initializers)
<< /*scalar=*/2 << R;
break;
}
case FK_ReferenceBindingToInitList:
S.Diag(Kind.getLocation(), diag::err_reference_bind_init_list)
<< DestType.getNonReferenceType() << Args[0]->getSourceRange();
break;
case FK_InitListBadDestinationType:
S.Diag(Kind.getLocation(), diag::err_init_list_bad_dest_type)
<< (DestType->isRecordType()) << DestType << Args[0]->getSourceRange();
break;
case FK_ListConstructorOverloadFailed:
case FK_ConstructorOverloadFailed: {
SourceRange ArgsRange;
if (Args.size())
ArgsRange = SourceRange(Args.front()->getLocStart(),
Args.back()->getLocEnd());
if (Failure == FK_ListConstructorOverloadFailed) {
assert(Args.size() == 1 &&
"List construction from other than 1 argument.");
InitListExpr *InitList = cast<InitListExpr>(Args[0]);
Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
}
// FIXME: Using "DestType" for the entity we're printing is probably
// bad.
switch (FailedOverloadResult) {
case OR_Ambiguous:
S.Diag(Kind.getLocation(), diag::err_ovl_ambiguous_init)
<< DestType << ArgsRange;
FailedCandidateSet.NoteCandidates(S, OCD_ViableCandidates, Args);
break;
case OR_No_Viable_Function:
if (Kind.getKind() == InitializationKind::IK_Default &&
(Entity.getKind() == InitializedEntity::EK_Base ||
Entity.getKind() == InitializedEntity::EK_Member) &&
isa<CXXConstructorDecl>(S.CurContext)) {
// This is implicit default initialization of a member or
// base within a constructor. If no viable function was
// found, notify the user that she needs to explicitly
// initialize this base/member.
CXXConstructorDecl *Constructor
= cast<CXXConstructorDecl>(S.CurContext);
if (Entity.getKind() == InitializedEntity::EK_Base) {
S.Diag(Kind.getLocation(), diag::err_missing_default_ctor)
<< (Constructor->getInheritedConstructor() ? 2 :
Constructor->isImplicit() ? 1 : 0)
<< S.Context.getTypeDeclType(Constructor->getParent())
<< /*base=*/0
<< Entity.getType();
RecordDecl *BaseDecl
= Entity.getBaseSpecifier()->getType()->getAs<RecordType>()
->getDecl();
S.Diag(BaseDecl->getLocation(), diag::note_previous_decl)
<< S.Context.getTagDeclType(BaseDecl);
} else {
S.Diag(Kind.getLocation(), diag::err_missing_default_ctor)
<< (Constructor->getInheritedConstructor() ? 2 :
Constructor->isImplicit() ? 1 : 0)
<< S.Context.getTypeDeclType(Constructor->getParent())
<< /*member=*/1
<< Entity.getName();
S.Diag(Entity.getDecl()->getLocation(),
diag::note_member_declared_at);
if (const RecordType *Record
= Entity.getType()->getAs<RecordType>())
S.Diag(Record->getDecl()->getLocation(),
diag::note_previous_decl)
<< S.Context.getTagDeclType(Record->getDecl());
}
break;
}
S.Diag(Kind.getLocation(), diag::err_ovl_no_viable_function_in_init)
<< DestType << ArgsRange;
FailedCandidateSet.NoteCandidates(S, OCD_AllCandidates, Args);
break;
case OR_Deleted: {
OverloadCandidateSet::iterator Best;
OverloadingResult Ovl
= FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best);
if (Ovl != OR_Deleted) {
S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init)
<< true << DestType << ArgsRange;
llvm_unreachable("Inconsistent overload resolution?");
break;
}
// If this is a defaulted or implicitly-declared function, then
// it was implicitly deleted. Make it clear that the deletion was
// implicit.
if (S.isImplicitlyDeleted(Best->Function))
S.Diag(Kind.getLocation(), diag::err_ovl_deleted_special_init)
<< S.getSpecialMember(cast<CXXMethodDecl>(Best->Function))
<< DestType << ArgsRange;
else
S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init)
<< true << DestType << ArgsRange;
S.NoteDeletedFunction(Best->Function);
break;
}
case OR_Success:
llvm_unreachable("Conversion did not fail!");
}
}
break;
case FK_DefaultInitOfConst:
if (Entity.getKind() == InitializedEntity::EK_Member &&
isa<CXXConstructorDecl>(S.CurContext)) {
// This is implicit default-initialization of a const member in
// a constructor. Complain that it needs to be explicitly
// initialized.
CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(S.CurContext);
S.Diag(Kind.getLocation(), diag::err_uninitialized_member_in_ctor)
<< (Constructor->getInheritedConstructor() ? 2 :
Constructor->isImplicit() ? 1 : 0)
<< S.Context.getTypeDeclType(Constructor->getParent())
<< /*const=*/1
<< Entity.getName();
S.Diag(Entity.getDecl()->getLocation(), diag::note_previous_decl)
<< Entity.getName();
} else {
S.Diag(Kind.getLocation(), diag::err_default_init_const)
<< DestType << (bool)DestType->getAs<RecordType>();
maybeEmitZeroInitializationFixit(S, *this, Entity);
}
break;
case FK_Incomplete:
S.RequireCompleteType(Kind.getLocation(), FailedIncompleteType,
diag::err_init_incomplete_type);
break;
case FK_ListInitializationFailed: {
// Run the init list checker again to emit diagnostics.
InitListExpr *InitList = cast<InitListExpr>(Args[0]);
diagnoseListInit(S, Entity, InitList);
break;
}
case FK_PlaceholderType: {
// FIXME: Already diagnosed!
break;
}
case FK_ExplicitConstructor: {
S.Diag(Kind.getLocation(), diag::err_selected_explicit_constructor)
<< Args[0]->getSourceRange();
OverloadCandidateSet::iterator Best;
OverloadingResult Ovl
= FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best);
(void)Ovl;
assert(Ovl == OR_Success && "Inconsistent overload resolution");
CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
S.Diag(CtorDecl->getLocation(), diag::note_constructor_declared_here);
break;
}
}
PrintInitLocationNote(S, Entity);
return true;
}
void InitializationSequence::dump(raw_ostream &OS) const {
switch (SequenceKind) {
case FailedSequence: {
OS << "Failed sequence: ";
switch (Failure) {
case FK_TooManyInitsForReference:
OS << "too many initializers for reference";
break;
case FK_ArrayNeedsInitList:
OS << "array requires initializer list";
break;
case FK_ArrayNeedsInitListOrStringLiteral:
OS << "array requires initializer list or string literal";
break;
case FK_ArrayNeedsInitListOrWideStringLiteral:
OS << "array requires initializer list or wide string literal";
break;
case FK_NarrowStringIntoWideCharArray:
OS << "narrow string into wide char array";
break;
case FK_WideStringIntoCharArray:
OS << "wide string into char array";
break;
case FK_IncompatWideStringIntoWideChar:
OS << "incompatible wide string into wide char array";
break;
case FK_ArrayTypeMismatch:
OS << "array type mismatch";
break;
case FK_NonConstantArrayInit:
OS << "non-constant array initializer";
break;
case FK_AddressOfOverloadFailed:
OS << "address of overloaded function failed";
break;
case FK_ReferenceInitOverloadFailed:
OS << "overload resolution for reference initialization failed";
break;
case FK_NonConstLValueReferenceBindingToTemporary:
OS << "non-const lvalue reference bound to temporary";
break;
case FK_NonConstLValueReferenceBindingToUnrelated:
OS << "non-const lvalue reference bound to unrelated type";
break;
case FK_RValueReferenceBindingToLValue:
OS << "rvalue reference bound to an lvalue";
break;
case FK_ReferenceInitDropsQualifiers:
OS << "reference initialization drops qualifiers";
break;
case FK_ReferenceInitFailed:
OS << "reference initialization failed";
break;
case FK_ConversionFailed:
OS << "conversion failed";
break;
case FK_ConversionFromPropertyFailed:
OS << "conversion from property failed";
break;
case FK_TooManyInitsForScalar:
OS << "too many initializers for scalar";
break;
case FK_ReferenceBindingToInitList:
OS << "referencing binding to initializer list";
break;
case FK_InitListBadDestinationType:
OS << "initializer list for non-aggregate, non-scalar type";
break;
case FK_UserConversionOverloadFailed:
OS << "overloading failed for user-defined conversion";
break;
case FK_ConstructorOverloadFailed:
OS << "constructor overloading failed";
break;
case FK_DefaultInitOfConst:
OS << "default initialization of a const variable";
break;
case FK_Incomplete:
OS << "initialization of incomplete type";
break;
case FK_ListInitializationFailed:
OS << "list initialization checker failure";
break;
case FK_VariableLengthArrayHasInitializer:
OS << "variable length array has an initializer";
break;
case FK_PlaceholderType:
OS << "initializer expression isn't contextually valid";
break;
case FK_ListConstructorOverloadFailed:
OS << "list constructor overloading failed";
break;
case FK_ExplicitConstructor:
OS << "list copy initialization chose explicit constructor";
break;
}
OS << '\n';
return;
}
case DependentSequence:
OS << "Dependent sequence\n";
return;
case NormalSequence:
OS << "Normal sequence: ";
break;
}
for (step_iterator S = step_begin(), SEnd = step_end(); S != SEnd; ++S) {
if (S != step_begin()) {
OS << " -> ";
}
switch (S->Kind) {
case SK_ResolveAddressOfOverloadedFunction:
OS << "resolve address of overloaded function";
break;
case SK_CastDerivedToBaseRValue:
OS << "derived-to-base case (rvalue" << S->Type.getAsString() << ")";
break;
case SK_CastDerivedToBaseXValue:
OS << "derived-to-base case (xvalue" << S->Type.getAsString() << ")";
break;
case SK_CastDerivedToBaseLValue:
OS << "derived-to-base case (lvalue" << S->Type.getAsString() << ")";
break;
case SK_BindReference:
OS << "bind reference to lvalue";
break;
case SK_BindReferenceToTemporary:
OS << "bind reference to a temporary";
break;
case SK_ExtraneousCopyToTemporary:
OS << "extraneous C++03 copy to temporary";
break;
case SK_UserConversion:
OS << "user-defined conversion via " << *S->Function.Function;
break;
case SK_QualificationConversionRValue:
OS << "qualification conversion (rvalue)";
break;
case SK_QualificationConversionXValue:
OS << "qualification conversion (xvalue)";
break;
case SK_QualificationConversionLValue:
OS << "qualification conversion (lvalue)";
break;
case SK_AtomicConversion:
OS << "non-atomic-to-atomic conversion";
break;
case SK_LValueToRValue:
OS << "load (lvalue to rvalue)";
break;
case SK_ConversionSequence:
OS << "implicit conversion sequence (";
S->ICS->dump(); // FIXME: use OS
OS << ")";
break;
case SK_ConversionSequenceNoNarrowing:
OS << "implicit conversion sequence with narrowing prohibited (";
S->ICS->dump(); // FIXME: use OS
OS << ")";
break;
case SK_ListInitialization:
OS << "list aggregate initialization";
break;
case SK_UnwrapInitList:
OS << "unwrap reference initializer list";
break;
case SK_RewrapInitList:
OS << "rewrap reference initializer list";
break;
case SK_ConstructorInitialization:
OS << "constructor initialization";
break;
case SK_ConstructorInitializationFromList:
OS << "list initialization via constructor";
break;
case SK_ZeroInitialization:
OS << "zero initialization";
break;
case SK_CAssignment:
OS << "C assignment";
break;
case SK_StringInit:
OS << "string initialization";
break;
case SK_ObjCObjectConversion:
OS << "Objective-C object conversion";
break;
case SK_ArrayInit:
OS << "array initialization";
break;
case SK_ParenthesizedArrayInit:
OS << "parenthesized array initialization";
break;
case SK_PassByIndirectCopyRestore:
OS << "pass by indirect copy and restore";
break;
case SK_PassByIndirectRestore:
OS << "pass by indirect restore";
break;
case SK_ProduceObjCObject:
OS << "Objective-C object retension";
break;
case SK_StdInitializerList:
OS << "std::initializer_list from initializer list";
break;
case SK_StdInitializerListConstructorCall:
OS << "list initialization from std::initializer_list";
break;
case SK_OCLSamplerInit:
OS << "OpenCL sampler_t from integer constant";
break;
case SK_OCLZeroEvent:
OS << "OpenCL event_t from zero";
break;
}
OS << " [" << S->Type.getAsString() << ']';
}
OS << '\n';
}
void InitializationSequence::dump() const {
dump(llvm::errs());
}
static void DiagnoseNarrowingInInitList(Sema &S,
const ImplicitConversionSequence &ICS,
QualType PreNarrowingType,
QualType EntityType,
const Expr *PostInit) {
const StandardConversionSequence *SCS = nullptr;
switch (ICS.getKind()) {
case ImplicitConversionSequence::StandardConversion:
SCS = &ICS.Standard;
break;
case ImplicitConversionSequence::UserDefinedConversion:
SCS = &ICS.UserDefined.After;
break;
case ImplicitConversionSequence::AmbiguousConversion:
case ImplicitConversionSequence::EllipsisConversion:
case ImplicitConversionSequence::BadConversion:
return;
}
// C++11 [dcl.init.list]p7: Check whether this is a narrowing conversion.
APValue ConstantValue;
QualType ConstantType;
switch (SCS->getNarrowingKind(S.Context, PostInit, ConstantValue,
ConstantType)) {
case NK_Not_Narrowing:
// No narrowing occurred.
return;
case NK_Type_Narrowing:
// This was a floating-to-integer conversion, which is always considered a
// narrowing conversion even if the value is a constant and can be
// represented exactly as an integer.
S.Diag(PostInit->getLocStart(),
(S.getLangOpts().MicrosoftExt || !S.getLangOpts().CPlusPlus11)
? diag::warn_init_list_type_narrowing
: diag::ext_init_list_type_narrowing)
<< PostInit->getSourceRange()
<< PreNarrowingType.getLocalUnqualifiedType()
<< EntityType.getLocalUnqualifiedType();
break;
case NK_Constant_Narrowing:
// A constant value was narrowed.
S.Diag(PostInit->getLocStart(),
(S.getLangOpts().MicrosoftExt || !S.getLangOpts().CPlusPlus11)
? diag::warn_init_list_constant_narrowing
: diag::ext_init_list_constant_narrowing)
<< PostInit->getSourceRange()
<< ConstantValue.getAsString(S.getASTContext(), ConstantType)
<< EntityType.getLocalUnqualifiedType();
break;
case NK_Variable_Narrowing:
// A variable's value may have been narrowed.
S.Diag(PostInit->getLocStart(),
(S.getLangOpts().MicrosoftExt || !S.getLangOpts().CPlusPlus11)
? diag::warn_init_list_variable_narrowing
: diag::ext_init_list_variable_narrowing)
<< PostInit->getSourceRange()
<< PreNarrowingType.getLocalUnqualifiedType()
<< EntityType.getLocalUnqualifiedType();
break;
}
SmallString<128> StaticCast;
llvm::raw_svector_ostream OS(StaticCast);
OS << "static_cast<";
if (const TypedefType *TT = EntityType->getAs<TypedefType>()) {
// It's important to use the typedef's name if there is one so that the
// fixit doesn't break code using types like int64_t.
//
// FIXME: This will break if the typedef requires qualification. But
// getQualifiedNameAsString() includes non-machine-parsable components.
OS << *TT->getDecl();
} else if (const BuiltinType *BT = EntityType->getAs<BuiltinType>())
OS << BT->getName(S.getLangOpts());
else {
// Oops, we didn't find the actual type of the variable. Don't emit a fixit
// with a broken cast.
return;
}
OS << ">(";
S.Diag(PostInit->getLocStart(), diag::note_init_list_narrowing_silence)
<< PostInit->getSourceRange()
<< FixItHint::CreateInsertion(PostInit->getLocStart(), OS.str())
<< FixItHint::CreateInsertion(
S.getLocForEndOfToken(PostInit->getLocEnd()), ")");
}
//===----------------------------------------------------------------------===//
// Initialization helper functions
//===----------------------------------------------------------------------===//
bool
Sema::CanPerformCopyInitialization(const InitializedEntity &Entity,
ExprResult Init) {
if (Init.isInvalid())
return false;
Expr *InitE = Init.get();
assert(InitE && "No initialization expression");
InitializationKind Kind
= InitializationKind::CreateCopy(InitE->getLocStart(), SourceLocation());
InitializationSequence Seq(*this, Entity, Kind, InitE);
return !Seq.Failed();
}
ExprResult
Sema::PerformCopyInitialization(const InitializedEntity &Entity,
SourceLocation EqualLoc,
ExprResult Init,
bool TopLevelOfInitList,
bool AllowExplicit) {
if (Init.isInvalid())
return ExprError();
Expr *InitE = Init.get();
assert(InitE && "No initialization expression?");
if (EqualLoc.isInvalid())
EqualLoc = InitE->getLocStart();
InitializationKind Kind = InitializationKind::CreateCopy(InitE->getLocStart(),
EqualLoc,
AllowExplicit);
InitializationSequence Seq(*this, Entity, Kind, InitE, TopLevelOfInitList);
Init.get();
ExprResult Result = Seq.Perform(*this, Entity, Kind, InitE);
return Result;
}
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