//===--- 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/Lex/Preprocessor.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 == 0) 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::warn_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, unsigned &Index, InitListExpr *StructuredList, unsigned &StructuredIndex, 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); void FillInValueInitForField(unsigned Init, FieldDecl *Field, const InitializedEntity &ParentEntity, InitListExpr *ILE, bool &RequiresSecondPass); void FillInValueInitializations(const InitializedEntity &Entity, InitListExpr *ILE, bool &RequiresSecondPass); bool CheckFlexibleArrayInit(const InitializedEntity &Entity, Expr *InitExpr, FieldDecl *Field, bool TopLevelObject); void CheckValueInitializable(const InitializedEntity &Entity); 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 void InitListChecker::CheckValueInitializable(const InitializedEntity &Entity) { assert(VerifyOnly && "CheckValueInitializable is only inteded for verification mode."); SourceLocation Loc; InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc, true); InitializationSequence InitSeq(SemaRef, Entity, Kind, None); if (InitSeq.Failed()) hadError = true; } void InitListChecker::FillInValueInitForField(unsigned Init, FieldDecl *Field, const InitializedEntity &ParentEntity, InitListExpr *ILE, bool &RequiresSecondPass) { SourceLocation Loc = ILE->getLocStart(); unsigned NumInits = ILE->getNumInits(); InitializedEntity MemberEntity = InitializedEntity::InitializeMember(Field, &ParentEntity); if (Init >= NumInits || !ILE->getInit(Init)) { // If there's no explicit initializer but we have a default initializer, use // that. This only happens in C++1y, since classes with default // initializers are not aggregates in C++11. if (Field->hasInClassInitializer()) { Expr *DIE = CXXDefaultInitExpr::Create(SemaRef.Context, ILE->getRBraceLoc(), Field); if (Init < NumInits) ILE->setInit(Init, DIE); else { ILE->updateInit(SemaRef.Context, Init, DIE); RequiresSecondPass = true; } return; } // FIXME: We probably don't need to handle references // specially here, since value-initialization of references is // handled in InitializationSequence. 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; } InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc, true); InitializationSequence InitSeq(SemaRef, MemberEntity, Kind, None); if (!InitSeq) { InitSeq.Diagnose(SemaRef, MemberEntity, Kind, None); hadError = true; return; } ExprResult MemberInit = InitSeq.Perform(SemaRef, MemberEntity, Kind, None); if (MemberInit.isInvalid()) { hadError = true; return; } if (hadError) { // Do nothing } else if (Init < NumInits) { ILE->setInit(Init, MemberInit.takeAs<Expr>()); } else if (InitSeq.isConstructorInitialization()) { // Value-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.takeAs<Expr>()); RequiresSecondPass = true; } } else if (InitListExpr *InnerILE = dyn_cast<InitListExpr>(ILE->getInit(Init))) FillInValueInitializations(MemberEntity, InnerILE, RequiresSecondPass); } /// Recursively replaces NULL values within the given initializer list /// with expressions that perform value-initialization of the /// appropriate type. void InitListChecker::FillInValueInitializations(const InitializedEntity &Entity, InitListExpr *ILE, bool &RequiresSecondPass) { assert((ILE->getType() != SemaRef.Context.VoidTy) && "Should not have void type"); SourceLocation Loc = ILE->getLocStart(); if (ILE->getSyntacticForm()) Loc = ILE->getSyntacticForm()->getLocStart(); if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) { const RecordDecl *RDecl = RType->getDecl(); if (RDecl->isUnion() && ILE->getInitializedFieldInUnion()) FillInValueInitForField(0, ILE->getInitializedFieldInUnion(), Entity, ILE, RequiresSecondPass); else if (RDecl->isUnion() && isa<CXXRecordDecl>(RDecl) && cast<CXXRecordDecl>(RDecl)->hasInClassInitializer()) { for (RecordDecl::field_iterator Field = RDecl->field_begin(), FieldEnd = RDecl->field_end(); Field != FieldEnd; ++Field) { if (Field->hasInClassInitializer()) { FillInValueInitForField(0, *Field, Entity, ILE, RequiresSecondPass); break; } } } else { unsigned Init = 0; for (RecordDecl::field_iterator Field = RDecl->field_begin(), FieldEnd = RDecl->field_end(); Field != FieldEnd; ++Field) { if (Field->isUnnamedBitfield()) continue; if (hadError) return; FillInValueInitForField(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) : 0); if (!InitExpr && !ILE->hasArrayFiller()) { InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc, true); InitializationSequence InitSeq(SemaRef, ElementEntity, Kind, None); if (!InitSeq) { InitSeq.Diagnose(SemaRef, ElementEntity, Kind, None); hadError = true; return; } ExprResult ElementInit = InitSeq.Perform(SemaRef, ElementEntity, Kind, None); 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.takeAs<Expr>()); else ILE->setInit(Init, ElementInit.takeAs<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.takeAs<Expr>()); return; } if (InitSeq.isConstructorInitialization()) { // Value-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.takeAs<Expr>()); RequiresSecondPass = true; } } } else if (InitListExpr *InnerILE = dyn_cast_or_null<InitListExpr>(InitExpr)) FillInValueInitializations(ElementEntity, InnerILE, RequiresSecondPass); } } InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity, InitListExpr *IL, QualType &T, bool VerifyOnly) : SemaRef(S), VerifyOnly(VerifyOnly) { hadError = false; unsigned newIndex = 0; unsigned newStructuredIndex = 0; FullyStructuredList = getStructuredSubobjectInit(IL, newIndex, T, 0, 0, IL->getSourceRange()); CheckExplicitInitList(Entity, IL, T, newIndex, FullyStructuredList, newStructuredIndex, /*TopLevelObject=*/true); if (!hadError && !VerifyOnly) { bool RequiresSecondPass = false; FillInValueInitializations(Entity, FullyStructuredList, RequiresSecondPass); if (RequiresSecondPass && !hadError) FillInValueInitializations(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 (RecordDecl::field_iterator Field = structDecl->field_begin(), FieldEnd = structDecl->field_end(); Field != FieldEnd; ++Field) { if (!Field->isUnnamedBitfield()) ++InitializableMembers; } if (structDecl->isUnion()) return std::min(InitializableMembers, 1); return InitializableMembers - structDecl->hasFlexibleArrayMember(); } 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.PP.getLocForEndOfToken( StructuredSubobjectInitList->getLocEnd()), "}"); } } } void InitListChecker::CheckExplicitInitList(const InitializedEntity &Entity, InitListExpr *IList, QualType &T, unsigned &Index, InitListExpr *StructuredList, unsigned &StructuredIndex, bool TopLevelObject) { assert(IList->isExplicit() && "Illegal Implicit InitListExpr"); if (!VerifyOnly) { SyntacticToSemantic[IList] = StructuredList; StructuredList->setSyntacticForm(IList); } 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::warn_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::warn_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()) { unsigned newIndex = 0; unsigned newStructuredIndex = 0; InitListExpr *newStructuredList = getStructuredSubobjectInit(IList, Index, ElemType, StructuredList, StructuredIndex, SubInitList->getSourceRange()); CheckExplicitInitList(Entity, SubInitList, ElemType, newIndex, newStructuredList, newStructuredIndex); ++StructuredIndex; ++Index; return; } assert(SemaRef.getLangOpts().CPlusPlus && "non-aggregate records are only possible in C++"); // C++ initialization is handled later. } if (ElemType->isScalarType()) return CheckScalarType(Entity, IList, ElemType, Index, StructuredList, StructuredIndex); 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.takeAs<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 = SemaRef.Owned(expr); if ((ElemType->isRecordType() || ElemType->isVectorType()) && SemaRef.CheckSingleAssignmentConstraints(ElemType, ExprRes, !VerifyOnly) == Sema::Compatible) { if (ExprRes.isInvalid()) hadError = true; else { ExprRes = SemaRef.DefaultFunctionArrayLvalueConversion(ExprRes.take()); if (ExprRes.isInvalid()) hadError = true; } UpdateStructuredListElement(StructuredList, StructuredIndex, ExprRes.takeAs<Expr>()); ++Index; return; } ExprRes.release(); // 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(), SemaRef.Owned(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)) { if (!VerifyOnly) SemaRef.Diag(SubIList->getLocStart(), diag::warn_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, SemaRef.Owned(expr))) hadError = true; ++Index; return; } ExprResult Result = SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), SemaRef.Owned(expr), /*TopLevelOfInitList=*/true); Expr *ResultExpr = 0; if (Result.isInvalid()) hadError = true; // types weren't compatible. else { ResultExpr = Result.takeAs<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, SemaRef.Owned(expr))) hadError = true; ++Index; return; } ExprResult Result = SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), SemaRef.Owned(expr), /*TopLevelOfInitList=*/true); if (Result.isInvalid()) hadError = true; expr = Result.takeAs<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) CheckValueInitializable( InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity)); 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, SemaRef.Owned(Init))) hadError = true; ++Index; return; } ExprResult Result = SemaRef.PerformCopyInitialization(Entity, Init->getLocStart(), SemaRef.Owned(Init), /*TopLevelOfInitList=*/true); Expr *ResultExpr = 0; if (Result.isInvalid()) hadError = true; // types weren't compatible. else { ResultExpr = Result.takeAs<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) CheckValueInitializable(ElementEntity); break; } ElementEntity.setElementIndex(Index); CheckSubElementType(ElementEntity, IList, elementType, Index, StructuredList, StructuredIndex); } 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, 0, &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) CheckValueInitializable(InitializedEntity::InitializeElement( SemaRef.Context, 0, Entity)); } } 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) CheckValueInitializable( InitializedEntity::InitializeMember(*Field, &Entity)); 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, 0, 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->getName(); 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()) CheckValueInitializable( InitializedEntity::InitializeMember(*Field, &Entity)); } } 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 *)0, DIE->getDesignator(DesigIdx)->getDotLoc(), DIE->getDesignator(DesigIdx)->getFieldLoc())); else Replacements.push_back(Designator((IdentifierInfo *)0, 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()); } /// \brief Given an implicit anonymous field, search the IndirectField that /// corresponds to FieldName. static IndirectFieldDecl *FindIndirectFieldDesignator(FieldDecl *AnonField, IdentifierInfo *FieldName) { if (!FieldName) return 0; assert(AnonField->isAnonymousStructOrUnion()); Decl *NextDecl = AnonField->getNextDeclInContext(); while (IndirectFieldDecl *IF = dyn_cast_or_null<IndirectFieldDecl>(NextDecl)) { if (FieldName == IF->getAnonField()->getIdentifier()) return IF; NextDecl = NextDecl->getNextDeclInContext(); } return 0; } 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) {} virtual bool ValidateCandidate(const TypoCorrection &candidate) { 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; } // Note: we perform a linear search of the fields here, despite // the fact that we have a faster lookup method, because we always // need to compute the field's index. FieldDecl *KnownField = D->getField(); IdentifierInfo *FieldName = D->getFieldName(); unsigned FieldIndex = 0; RecordDecl::field_iterator Field = RT->getDecl()->field_begin(), FieldEnd = RT->getDecl()->field_end(); for (; Field != FieldEnd; ++Field) { if (Field->isUnnamedBitfield()) continue; // If we find a field representing an anonymous field, look in the // IndirectFieldDecl that follow for the designated initializer. if (!KnownField && Field->isAnonymousStructOrUnion()) { if (IndirectFieldDecl *IF = FindIndirectFieldDesignator(*Field, FieldName)) { // In verify mode, don't modify the original. if (VerifyOnly) DIE = CloneDesignatedInitExpr(SemaRef, DIE); ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, IF); D = DIE->getDesignator(DesigIdx); break; } } if (KnownField && KnownField == *Field) break; if (FieldName && FieldName == Field->getIdentifier()) break; ++FieldIndex; } if (Field == FieldEnd) { if (VerifyOnly) { ++Index; return true; // No typo correction when just trying this out. } // There was no normal field in the struct with the designated // name. Perform another lookup for this name, which may find // something that we can't designate (e.g., a member function), // may find nothing, or may find a member of an anonymous // struct/union. DeclContext::lookup_result Lookup = RT->getDecl()->lookup(FieldName); FieldDecl *ReplacementField = 0; if (Lookup.empty()) { // Name lookup didn't find anything. Determine whether this // was a typo for another field name. FieldInitializerValidatorCCC Validator(RT->getDecl()); TypoCorrection Corrected = SemaRef.CorrectTypo( DeclarationNameInfo(FieldName, D->getFieldLoc()), Sema::LookupMemberName, /*Scope=*/0, /*SS=*/0, Validator, RT->getDecl()); if (Corrected) { std::string CorrectedStr( Corrected.getAsString(SemaRef.getLangOpts())); std::string CorrectedQuotedStr( Corrected.getQuoted(SemaRef.getLangOpts())); ReplacementField = Corrected.getCorrectionDeclAs<FieldDecl>(); SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown_suggest) << FieldName << CurrentObjectType << CorrectedQuotedStr << FixItHint::CreateReplacement(D->getFieldLoc(), CorrectedStr); SemaRef.Diag(ReplacementField->getLocation(), diag::note_previous_decl) << CorrectedQuotedStr; hadError = true; } else { SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown) << FieldName << CurrentObjectType; ++Index; return true; } } if (!ReplacementField) { // Name lookup found something, but it wasn't a field. SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_nonfield) << FieldName; SemaRef.Diag(Lookup.front()->getLocation(), diag::note_field_designator_found); ++Index; return true; } if (!KnownField) { // The replacement field comes from typo correction; find it // in the list of fields. FieldIndex = 0; Field = RT->getDecl()->field_begin(); for (; Field != FieldEnd; ++Field) { if (Field->isUnnamedBitfield()) continue; if (ReplacementField == *Field || Field->getIdentifier() == ReplacementField->getIdentifier()) break; ++FieldIndex; } } } // 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) 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, 0, 0, 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 = 0; 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, 0, 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, 0, 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, 0, 0, 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 0; // No structured list in verification-only mode. Expr *ExistingInit = 0; 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).take(); 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).take(); if (!EndDependent) EndIndex = CheckArrayDesignatorExpr(*this, EndIndex, EndValue).take(); 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.takeAs<Expr>()); if (!getLangOpts().C99) Diag(DIE->getLocStart(), diag::ext_designated_init) << DIE->getSourceRange(); return Owned(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 = 0; 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 Capture.Var->getDeclName(); 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 0; } 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 "; getCapturedVar()->printName(OS); 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_LValueToRValue: case SK_ListInitialization: case SK_ListConstructorCall: case SK_UnwrapInitList: case SK_RewrapInitList: case SK_ConstructorInitialization: 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_OCLSamplerInit: case SK_OCLZeroEvent: break; case SK_ConversionSequence: 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::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) { Step S; S.Kind = 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_ListConstructorCall : 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 = 0; FunctionTemplateDecl *ConstructorTmpl = dyn_cast<FunctionTemplateDecl>(D); if (ConstructorTmpl) Constructor = cast<CXXConstructorDecl>( ConstructorTmpl->getTemplatedDecl()); else { Constructor = cast<CXXConstructorDecl>(D); // If we're performing copy initialization using a copy constructor, we // suppress user-defined conversions on the arguments. We do the same for // move constructors. 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*/ 0, 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 = 0); /// \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; } } 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.allowExplicitConversionFunctions(); const RecordType *T1RecordType = 0; 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 = 0; 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*/ 0, 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 = 0; 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); else S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Initializer, DestType, CandidateSet); } } } 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->getResultType(); 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 rvlaue 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. 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", 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, const InitializedEntity &Entity, const InitializationKind &Kind, Expr *Initializer, InitializationSequence &Sequence) { QualType DestType = Entity.getType(); 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 = 0; 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*/ 0, 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); else S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Initializer, DestType, CandidateSet); } } } } // 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); } } /// 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) : FailedCandidateSet(Kind.getLocation()) { 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.take(); } // 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 = 0; if (Args.size() == 1) { Initializer = Args[0]; 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, Entity.getType(), *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, Entity, Kind, Initializer, *this); 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()) { TryUserDefinedConversion(S, Entity, Kind, Initializer, *this); MaybeProduceObjCObject(S, *this, Entity); 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, Entity.getType(), /*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(Entity.getType(), 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, Entity.getType()); 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 = 0; 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, 0, 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 = 0; 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); 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.release(); // 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 S.Owned(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, /*ZeroInit*/ false, CXXConstructExpr::CK_Complete, SourceRange()); // If we're supposed to bind temporaries, do so. if (!CurInit.isInvalid() && shouldBindAsTemporary(Entity)) CurInit = S.MaybeBindToTemporary(CurInit.takeAs<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.getDiagnosticLevel(diag::warn_cxx98_compat_temp_copy, Loc) == DiagnosticsEngine::Ignored) return; // Find constructors which would have been considered. OverloadCandidateSet CandidateSet(Loc); 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) { 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 = S.Owned((Expr *)0); // 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 ParenRange; if (Kind.getKind() != InitializationKind::IK_DirectList) ParenRange = Kind.getParenRange(); CurInit = S.Owned( new (S.Context) CXXTemporaryObjectExpr(S.Context, Constructor, TSInfo, ConstructorArgs, ParenRange, IsListInitialization, HadMultipleCandidates, 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 range if it is a direct construction. SourceRange parenRange = Kind.getKind() == InitializationKind::IK_Direct ? Kind.getParenRange() : SourceRange(); // 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, ConstructorInitRequiresZeroInit, ConstructKind, parenRange); else CurInit = S.BuildCXXConstructExpr(Loc, Entity.getType(), Constructor, ConstructorArgs, HadMultipleCandidates, IsListInitialization, ConstructorInitRequiresZeroInit, ConstructKind, parenRange); } 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.take()); 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 ValueDecl * getDeclForTemporaryLifetimeExtension(const InitializedEntity &Entity, const ValueDecl *FallbackDecl = 0) { // C++11 [class.temporary]p5: switch (Entity.getKind()) { case InitializedEntity::EK_Variable: // The temporary [...] persists for the lifetime of the reference return Entity.getDecl(); case InitializedEntity::EK_Member: // For subobjects, we look at the complete object. if (Entity.getParent()) return getDeclForTemporaryLifetimeExtension(*Entity.getParent(), Entity.getDecl()); // except: // -- A temporary bound to a reference member in a constructor's // ctor-initializer persists until the constructor exits. return Entity.getDecl(); 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 0; 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 0; case InitializedEntity::EK_ArrayElement: // For subobjects, we look at the complete object. return getDeclForTemporaryLifetimeExtension(*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 0; } llvm_unreachable("unknown entity kind"); } static void performLifetimeExtension(Expr *Init, const ValueDecl *ExtendingD); /// 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 ValueDecl *ExtendingD) { 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(ExtendingD); performLifetimeExtension(ME->GetTemporaryExpr(), ExtendingD); 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 ValueDecl *ExtendingD) { // 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(), ExtendingD); 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), ExtendingD); 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), ExtendingD); else { unsigned Index = 0; for (RecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end(); I != E; ++I) { if (Index >= ILE->getNumInits()) break; if (I->isUnnamedBitfield()) continue; Expr *SubInit = ILE->getInit(Index); if (I->getType()->isReferenceType()) performReferenceExtension(SubInit, ExtendingD); 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, ExtendingD); ++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; } } 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=*/0, 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 S.Owned((Expr *)0); 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 = S.Owned((Expr *)0); // 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_LValueToRValue: case SK_ConversionSequence: 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_ListConstructorCall: 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 = S.Owned(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 != NULL) << 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 ValueDecl *ExtendingDecl = getDeclForTemporaryLifetimeExtension(Entity)) { if (performReferenceExtension(CurInit.get(), ExtendingDecl)) warnOnLifetimeExtension(S, Entity, CurInit.get(), false, ExtendingDecl); } 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(); // Maybe lifetime-extend the temporary's subobjects to match the // entity's lifetime. const ValueDecl *ExtendingDecl = getDeclForTemporaryLifetimeExtension(Entity); if (ExtendingDecl) { performLifetimeExtension(CurInit.get(), ExtendingDecl); warnOnLifetimeExtension(S, Entity, CurInit.get(), false, ExtendingDecl); } // Materialize the temporary into memory. MaterializeTemporaryExpr *MTE = new (S.Context) MaterializeTemporaryExpr( Entity.getType().getNonReferenceType(), CurInit.get(), Entity.getType()->isLValueReferenceType(), ExtendingDecl); // 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 = S.Owned(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.release(); // 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, /*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(), 0, 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.take(), /*Qualifier=*/0, 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->getResultType()->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 = S.Owned(ImplicitCastExpr::Create(S.Context, CurInit.get()->getType(), CastKind, CurInit.get(), 0, CurInit.get()->getValueKind())); if (MaybeBindToTemp) CurInit = S.MaybeBindToTemporary(CurInit.takeAs<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.take(), Step->Type, CK_NoOp, VK); break; } case SK_LValueToRValue: { assert(CurInit.get()->isGLValue() && "cannot load from a prvalue"); CurInit = S.Owned(ImplicitCastExpr::Create(S.Context, Step->Type, CK_LValueToRValue, CurInit.take(), /*BasePath=*/0, VK_RValue)); break; } case SK_ConversionSequence: { 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; 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.release(); CurInit = shouldBindAsTemporary(InitEntity) ? S.MaybeBindToTemporary(StructuredInitList) : S.Owned(StructuredInitList); break; } case SK_ListConstructorCall: { // 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); break; } case SK_UnwrapInitList: CurInit = S.Owned(cast<InitListExpr>(CurInit.take())->getInit(0)); break; case SK_RewrapInitList: { Expr *E = CurInit.take(); 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 = S.Owned(ILE); break; } case SK_ConstructorInitialization: { // 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(); CurInit = PerformConstructorInitialization(S, UseTemporary ? TempEntity : Entity, Kind, Args, *Step, ConstructorInitRequiresZeroInit, /*IsListInitialization*/ false); break; } case SK_ZeroInitialization: { step_iterator NextStep = Step; ++NextStep; if (NextStep != StepEnd && (NextStep->Kind == SK_ConstructorInitialization || NextStep->Kind == SK_ListConstructorCall)) { // 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 = S.Owned(new (S.Context) CXXScalarValueInitExpr( TSInfo->getType().getNonLValueExprType(S.Context), TSInfo, Kind.getRange().getEnd())); } else { CurInit = S.Owned(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.take(), 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 = S.Owned(new (S.Context) ObjCIndirectCopyRestoreExpr(CurInit.take(), Step->Type, Step->Kind == SK_PassByIndirectCopyRestore)); break; case SK_ProduceObjCObject: CurInit = S.Owned(ImplicitCastExpr::Create(S.Context, Step->Type, CK_ARCProduceObject, CurInit.take(), 0, VK_RValue)); break; case SK_StdInitializerList: { S.Diag(CurInit.get()->getExprLoc(), diag::warn_cxx98_compat_initializer_list_init) << CurInit.get()->getSourceRange(); // Maybe lifetime-extend the array temporary's subobjects to match the // entity's lifetime. const ValueDecl *ExtendingDecl = getDeclForTemporaryLifetimeExtension(Entity); if (ExtendingDecl) { performLifetimeExtension(CurInit.get(), ExtendingDecl); warnOnLifetimeExtension(S, Entity, CurInit.get(), true, ExtendingDecl); } // Materialize the temporary into memory. MaterializeTemporaryExpr *MTE = new (S.Context) MaterializeTemporaryExpr(CurInit.get()->getType(), CurInit.get(), /*lvalue reference*/ false, ExtendingDecl); // Wrap it in a construction of a std::initializer_list<T>. CurInit = S.Owned( 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.take()); 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.take(), 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 (CXXRecordDecl::field_iterator FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI) { if (FI->isUnnamedBitfield()) continue; if (DiagnoseUninitializedReference(S, FI->getLocation(), FI->getType())) { S.Diag(Loc, diag::note_value_initialization_here) << RD; return true; } } for (CXXRecordDecl::base_class_iterator BI = RD->bases_begin(), BE = RD->bases_end(); BI != BE; ++BI) { 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); } } 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.PP.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_field_decl); 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>(); } 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]); QualType DestType = Entity.getType(); InitListChecker DiagnoseInitList(S, Entity, InitList, DestType, /*VerifyOnly=*/false); assert(DiagnoseInitList.HadError() && "Inconsistent init list check result."); 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_LValueToRValue: OS << "load (lvalue to rvalue)"; break; case SK_ConversionSequence: OS << "implicit conversion sequence ("; S->ICS->DebugPrint(); // FIXME: use OS OS << ")"; break; case SK_ListInitialization: OS << "list aggregate initialization"; break; case SK_ListConstructorCall: OS << "list initialization via constructor"; 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_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_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, InitializationSequence &Seq, QualType EntityType, const Expr *PreInit, const Expr *PostInit) { if (Seq.step_begin() == Seq.step_end() || PreInit->isValueDependent()) return; // A narrowing conversion can only appear as the final implicit conversion in // an initialization sequence. const InitializationSequence::Step &LastStep = Seq.step_end()[-1]; if (LastStep.Kind != InitializationSequence::SK_ConversionSequence) return; const ImplicitConversionSequence &ICS = *LastStep.ICS; const StandardConversionSequence *SCS = 0; 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; } // Determine the type prior to the narrowing conversion. If a conversion // operator was used, this may be different from both the type of the entity // and of the pre-initialization expression. QualType PreNarrowingType = PreInit->getType(); if (Seq.step_begin() + 1 != Seq.step_end()) PreNarrowingType = Seq.step_end()[-2].Type; // 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 : S.isSFINAEContext()? diag::err_init_list_type_narrowing_sfinae : diag::err_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 : S.isSFINAEContext()? diag::err_init_list_constant_narrowing_sfinae : diag::err_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 : S.isSFINAEContext()? diag::err_init_list_variable_narrowing_sfinae : diag::err_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_override) << PostInit->getSourceRange() << FixItHint::CreateInsertion(PostInit->getLocStart(), OS.str()) << FixItHint::CreateInsertion( S.getPreprocessor().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); Init.release(); ExprResult Result = Seq.Perform(*this, Entity, Kind, InitE); if (!Result.isInvalid() && TopLevelOfInitList) DiagnoseNarrowingInInitList(*this, Seq, Entity.getType(), InitE, Result.get()); return Result; }