//===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// /// /// \file /// \brief Implements semantic analysis for C++ expressions. /// //===----------------------------------------------------------------------===// #include "clang/Sema/SemaInternal.h" #include "TreeTransform.h" #include "TypeLocBuilder.h" #include "clang/AST/ASTContext.h" #include "clang/AST/ASTLambda.h" #include "clang/AST/CXXInheritance.h" #include "clang/AST/CharUnits.h" #include "clang/AST/DeclObjC.h" #include "clang/AST/ExprCXX.h" #include "clang/AST/ExprObjC.h" #include "clang/AST/RecursiveASTVisitor.h" #include "clang/AST/TypeLoc.h" #include "clang/Basic/PartialDiagnostic.h" #include "clang/Basic/TargetInfo.h" #include "clang/Lex/Preprocessor.h" #include "clang/Sema/DeclSpec.h" #include "clang/Sema/Initialization.h" #include "clang/Sema/Lookup.h" #include "clang/Sema/ParsedTemplate.h" #include "clang/Sema/Scope.h" #include "clang/Sema/ScopeInfo.h" #include "clang/Sema/SemaLambda.h" #include "clang/Sema/TemplateDeduction.h" #include "llvm/ADT/APInt.h" #include "llvm/ADT/STLExtras.h" #include "llvm/Support/ErrorHandling.h" using namespace clang; using namespace sema; /// \brief Handle the result of the special case name lookup for inheriting /// constructor declarations. 'NS::X::X' and 'NS::X<...>::X' are treated as /// constructor names in member using declarations, even if 'X' is not the /// name of the corresponding type. ParsedType Sema::getInheritingConstructorName(CXXScopeSpec &SS, SourceLocation NameLoc, IdentifierInfo &Name) { NestedNameSpecifier *NNS = SS.getScopeRep(); // Convert the nested-name-specifier into a type. QualType Type; switch (NNS->getKind()) { case NestedNameSpecifier::TypeSpec: case NestedNameSpecifier::TypeSpecWithTemplate: Type = QualType(NNS->getAsType(), 0); break; case NestedNameSpecifier::Identifier: // Strip off the last layer of the nested-name-specifier and build a // typename type for it. assert(NNS->getAsIdentifier() == &Name && "not a constructor name"); Type = Context.getDependentNameType(ETK_None, NNS->getPrefix(), NNS->getAsIdentifier()); break; case NestedNameSpecifier::Global: case NestedNameSpecifier::Super: case NestedNameSpecifier::Namespace: case NestedNameSpecifier::NamespaceAlias: llvm_unreachable("Nested name specifier is not a type for inheriting ctor"); } // This reference to the type is located entirely at the location of the // final identifier in the qualified-id. return CreateParsedType(Type, Context.getTrivialTypeSourceInfo(Type, NameLoc)); } ParsedType Sema::getDestructorName(SourceLocation TildeLoc, IdentifierInfo &II, SourceLocation NameLoc, Scope *S, CXXScopeSpec &SS, ParsedType ObjectTypePtr, bool EnteringContext) { // Determine where to perform name lookup. // FIXME: This area of the standard is very messy, and the current // wording is rather unclear about which scopes we search for the // destructor name; see core issues 399 and 555. Issue 399 in // particular shows where the current description of destructor name // lookup is completely out of line with existing practice, e.g., // this appears to be ill-formed: // // namespace N { // template struct S { // ~S(); // }; // } // // void f(N::S* s) { // s->N::S::~S(); // } // // See also PR6358 and PR6359. // For this reason, we're currently only doing the C++03 version of this // code; the C++0x version has to wait until we get a proper spec. QualType SearchType; DeclContext *LookupCtx = nullptr; bool isDependent = false; bool LookInScope = false; if (SS.isInvalid()) return nullptr; // If we have an object type, it's because we are in a // pseudo-destructor-expression or a member access expression, and // we know what type we're looking for. if (ObjectTypePtr) SearchType = GetTypeFromParser(ObjectTypePtr); if (SS.isSet()) { NestedNameSpecifier *NNS = SS.getScopeRep(); bool AlreadySearched = false; bool LookAtPrefix = true; // C++11 [basic.lookup.qual]p6: // If a pseudo-destructor-name (5.2.4) contains a nested-name-specifier, // the type-names are looked up as types in the scope designated by the // nested-name-specifier. Similarly, in a qualified-id of the form: // // nested-name-specifier[opt] class-name :: ~ class-name // // the second class-name is looked up in the same scope as the first. // // Here, we determine whether the code below is permitted to look at the // prefix of the nested-name-specifier. DeclContext *DC = computeDeclContext(SS, EnteringContext); if (DC && DC->isFileContext()) { AlreadySearched = true; LookupCtx = DC; isDependent = false; } else if (DC && isa(DC)) { LookAtPrefix = false; LookInScope = true; } // The second case from the C++03 rules quoted further above. NestedNameSpecifier *Prefix = nullptr; if (AlreadySearched) { // Nothing left to do. } else if (LookAtPrefix && (Prefix = NNS->getPrefix())) { CXXScopeSpec PrefixSS; PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data())); LookupCtx = computeDeclContext(PrefixSS, EnteringContext); isDependent = isDependentScopeSpecifier(PrefixSS); } else if (ObjectTypePtr) { LookupCtx = computeDeclContext(SearchType); isDependent = SearchType->isDependentType(); } else { LookupCtx = computeDeclContext(SS, EnteringContext); isDependent = LookupCtx && LookupCtx->isDependentContext(); } } else if (ObjectTypePtr) { // C++ [basic.lookup.classref]p3: // If the unqualified-id is ~type-name, the type-name is looked up // in the context of the entire postfix-expression. If the type T // of the object expression is of a class type C, the type-name is // also looked up in the scope of class C. At least one of the // lookups shall find a name that refers to (possibly // cv-qualified) T. LookupCtx = computeDeclContext(SearchType); isDependent = SearchType->isDependentType(); assert((isDependent || !SearchType->isIncompleteType()) && "Caller should have completed object type"); LookInScope = true; } else { // Perform lookup into the current scope (only). LookInScope = true; } TypeDecl *NonMatchingTypeDecl = nullptr; LookupResult Found(*this, &II, NameLoc, LookupOrdinaryName); for (unsigned Step = 0; Step != 2; ++Step) { // Look for the name first in the computed lookup context (if we // have one) and, if that fails to find a match, in the scope (if // we're allowed to look there). Found.clear(); if (Step == 0 && LookupCtx) LookupQualifiedName(Found, LookupCtx); else if (Step == 1 && LookInScope && S) LookupName(Found, S); else continue; // FIXME: Should we be suppressing ambiguities here? if (Found.isAmbiguous()) return nullptr; if (TypeDecl *Type = Found.getAsSingle()) { QualType T = Context.getTypeDeclType(Type); MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false); if (SearchType.isNull() || SearchType->isDependentType() || Context.hasSameUnqualifiedType(T, SearchType)) { // We found our type! return CreateParsedType(T, Context.getTrivialTypeSourceInfo(T, NameLoc)); } if (!SearchType.isNull()) NonMatchingTypeDecl = Type; } // If the name that we found is a class template name, and it is // the same name as the template name in the last part of the // nested-name-specifier (if present) or the object type, then // this is the destructor for that class. // FIXME: This is a workaround until we get real drafting for core // issue 399, for which there isn't even an obvious direction. if (ClassTemplateDecl *Template = Found.getAsSingle()) { QualType MemberOfType; if (SS.isSet()) { if (DeclContext *Ctx = computeDeclContext(SS, EnteringContext)) { // Figure out the type of the context, if it has one. if (CXXRecordDecl *Record = dyn_cast(Ctx)) MemberOfType = Context.getTypeDeclType(Record); } } if (MemberOfType.isNull()) MemberOfType = SearchType; if (MemberOfType.isNull()) continue; // We're referring into a class template specialization. If the // class template we found is the same as the template being // specialized, we found what we are looking for. if (const RecordType *Record = MemberOfType->getAs()) { if (ClassTemplateSpecializationDecl *Spec = dyn_cast(Record->getDecl())) { if (Spec->getSpecializedTemplate()->getCanonicalDecl() == Template->getCanonicalDecl()) return CreateParsedType( MemberOfType, Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc)); } continue; } // We're referring to an unresolved class template // specialization. Determine whether we class template we found // is the same as the template being specialized or, if we don't // know which template is being specialized, that it at least // has the same name. if (const TemplateSpecializationType *SpecType = MemberOfType->getAs()) { TemplateName SpecName = SpecType->getTemplateName(); // The class template we found is the same template being // specialized. if (TemplateDecl *SpecTemplate = SpecName.getAsTemplateDecl()) { if (SpecTemplate->getCanonicalDecl() == Template->getCanonicalDecl()) return CreateParsedType( MemberOfType, Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc)); continue; } // The class template we found has the same name as the // (dependent) template name being specialized. if (DependentTemplateName *DepTemplate = SpecName.getAsDependentTemplateName()) { if (DepTemplate->isIdentifier() && DepTemplate->getIdentifier() == Template->getIdentifier()) return CreateParsedType( MemberOfType, Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc)); continue; } } } } if (isDependent) { // We didn't find our type, but that's okay: it's dependent // anyway. // FIXME: What if we have no nested-name-specifier? QualType T = CheckTypenameType(ETK_None, SourceLocation(), SS.getWithLocInContext(Context), II, NameLoc); return ParsedType::make(T); } if (NonMatchingTypeDecl) { QualType T = Context.getTypeDeclType(NonMatchingTypeDecl); Diag(NameLoc, diag::err_destructor_expr_type_mismatch) << T << SearchType; Diag(NonMatchingTypeDecl->getLocation(), diag::note_destructor_type_here) << T; } else if (ObjectTypePtr) Diag(NameLoc, diag::err_ident_in_dtor_not_a_type) << &II; else { SemaDiagnosticBuilder DtorDiag = Diag(NameLoc, diag::err_destructor_class_name); if (S) { const DeclContext *Ctx = S->getEntity(); if (const CXXRecordDecl *Class = dyn_cast_or_null(Ctx)) DtorDiag << FixItHint::CreateReplacement(SourceRange(NameLoc), Class->getNameAsString()); } } return nullptr; } ParsedType Sema::getDestructorType(const DeclSpec& DS, ParsedType ObjectType) { if (DS.getTypeSpecType() == DeclSpec::TST_error || !ObjectType) return nullptr; assert(DS.getTypeSpecType() == DeclSpec::TST_decltype && "only get destructor types from declspecs"); QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc()); QualType SearchType = GetTypeFromParser(ObjectType); if (SearchType->isDependentType() || Context.hasSameUnqualifiedType(SearchType, T)) { return ParsedType::make(T); } Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch) << T << SearchType; return nullptr; } bool Sema::checkLiteralOperatorId(const CXXScopeSpec &SS, const UnqualifiedId &Name) { assert(Name.getKind() == UnqualifiedId::IK_LiteralOperatorId); if (!SS.isValid()) return false; switch (SS.getScopeRep()->getKind()) { case NestedNameSpecifier::Identifier: case NestedNameSpecifier::TypeSpec: case NestedNameSpecifier::TypeSpecWithTemplate: // Per C++11 [over.literal]p2, literal operators can only be declared at // namespace scope. Therefore, this unqualified-id cannot name anything. // Reject it early, because we have no AST representation for this in the // case where the scope is dependent. Diag(Name.getLocStart(), diag::err_literal_operator_id_outside_namespace) << SS.getScopeRep(); return true; case NestedNameSpecifier::Global: case NestedNameSpecifier::Super: case NestedNameSpecifier::Namespace: case NestedNameSpecifier::NamespaceAlias: return false; } llvm_unreachable("unknown nested name specifier kind"); } /// \brief Build a C++ typeid expression with a type operand. ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType, SourceLocation TypeidLoc, TypeSourceInfo *Operand, SourceLocation RParenLoc) { // C++ [expr.typeid]p4: // The top-level cv-qualifiers of the lvalue expression or the type-id // that is the operand of typeid are always ignored. // If the type of the type-id is a class type or a reference to a class // type, the class shall be completely-defined. Qualifiers Quals; QualType T = Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(), Quals); if (T->getAs() && RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid)) return ExprError(); if (T->isVariablyModifiedType()) return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) << T); return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), Operand, SourceRange(TypeidLoc, RParenLoc)); } /// \brief Build a C++ typeid expression with an expression operand. ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType, SourceLocation TypeidLoc, Expr *E, SourceLocation RParenLoc) { bool WasEvaluated = false; if (E && !E->isTypeDependent()) { if (E->getType()->isPlaceholderType()) { ExprResult result = CheckPlaceholderExpr(E); if (result.isInvalid()) return ExprError(); E = result.get(); } QualType T = E->getType(); if (const RecordType *RecordT = T->getAs()) { CXXRecordDecl *RecordD = cast(RecordT->getDecl()); // C++ [expr.typeid]p3: // [...] If the type of the expression is a class type, the class // shall be completely-defined. if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid)) return ExprError(); // C++ [expr.typeid]p3: // When typeid is applied to an expression other than an glvalue of a // polymorphic class type [...] [the] expression is an unevaluated // operand. [...] if (RecordD->isPolymorphic() && E->isGLValue()) { // The subexpression is potentially evaluated; switch the context // and recheck the subexpression. ExprResult Result = TransformToPotentiallyEvaluated(E); if (Result.isInvalid()) return ExprError(); E = Result.get(); // We require a vtable to query the type at run time. MarkVTableUsed(TypeidLoc, RecordD); WasEvaluated = true; } } // C++ [expr.typeid]p4: // [...] If the type of the type-id is a reference to a possibly // cv-qualified type, the result of the typeid expression refers to a // std::type_info object representing the cv-unqualified referenced // type. Qualifiers Quals; QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals); if (!Context.hasSameType(T, UnqualT)) { T = UnqualT; E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).get(); } } if (E->getType()->isVariablyModifiedType()) return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) << E->getType()); else if (ActiveTemplateInstantiations.empty() && E->HasSideEffects(Context, WasEvaluated)) { // The expression operand for typeid is in an unevaluated expression // context, so side effects could result in unintended consequences. Diag(E->getExprLoc(), WasEvaluated ? diag::warn_side_effects_typeid : diag::warn_side_effects_unevaluated_context); } return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), E, SourceRange(TypeidLoc, RParenLoc)); } /// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression); ExprResult Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc, bool isType, void *TyOrExpr, SourceLocation RParenLoc) { // Find the std::type_info type. if (!getStdNamespace()) return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); if (!CXXTypeInfoDecl) { IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info"); LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName); LookupQualifiedName(R, getStdNamespace()); CXXTypeInfoDecl = R.getAsSingle(); // Microsoft's typeinfo doesn't have type_info in std but in the global // namespace if _HAS_EXCEPTIONS is defined to 0. See PR13153. if (!CXXTypeInfoDecl && LangOpts.MSVCCompat) { LookupQualifiedName(R, Context.getTranslationUnitDecl()); CXXTypeInfoDecl = R.getAsSingle(); } if (!CXXTypeInfoDecl) return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); } if (!getLangOpts().RTTI) { return ExprError(Diag(OpLoc, diag::err_no_typeid_with_fno_rtti)); } QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl); if (isType) { // The operand is a type; handle it as such. TypeSourceInfo *TInfo = nullptr; QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr), &TInfo); if (T.isNull()) return ExprError(); if (!TInfo) TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc); return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc); } // The operand is an expression. return BuildCXXTypeId(TypeInfoType, OpLoc, (Expr*)TyOrExpr, RParenLoc); } /// Grabs __declspec(uuid()) off a type, or returns 0 if we cannot resolve to /// a single GUID. static void getUuidAttrOfType(Sema &SemaRef, QualType QT, llvm::SmallSetVector &UuidAttrs) { // Optionally remove one level of pointer, reference or array indirection. const Type *Ty = QT.getTypePtr(); if (QT->isPointerType() || QT->isReferenceType()) Ty = QT->getPointeeType().getTypePtr(); else if (QT->isArrayType()) Ty = Ty->getBaseElementTypeUnsafe(); const auto *RD = Ty->getAsCXXRecordDecl(); if (!RD) return; if (const auto *Uuid = RD->getMostRecentDecl()->getAttr()) { UuidAttrs.insert(Uuid); return; } // __uuidof can grab UUIDs from template arguments. if (const auto *CTSD = dyn_cast(RD)) { const TemplateArgumentList &TAL = CTSD->getTemplateArgs(); for (const TemplateArgument &TA : TAL.asArray()) { const UuidAttr *UuidForTA = nullptr; if (TA.getKind() == TemplateArgument::Type) getUuidAttrOfType(SemaRef, TA.getAsType(), UuidAttrs); else if (TA.getKind() == TemplateArgument::Declaration) getUuidAttrOfType(SemaRef, TA.getAsDecl()->getType(), UuidAttrs); if (UuidForTA) UuidAttrs.insert(UuidForTA); } } } /// \brief Build a Microsoft __uuidof expression with a type operand. ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType, SourceLocation TypeidLoc, TypeSourceInfo *Operand, SourceLocation RParenLoc) { StringRef UuidStr; if (!Operand->getType()->isDependentType()) { llvm::SmallSetVector UuidAttrs; getUuidAttrOfType(*this, Operand->getType(), UuidAttrs); if (UuidAttrs.empty()) return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid)); if (UuidAttrs.size() > 1) return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids)); UuidStr = UuidAttrs.back()->getGuid(); } return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), Operand, UuidStr, SourceRange(TypeidLoc, RParenLoc)); } /// \brief Build a Microsoft __uuidof expression with an expression operand. ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType, SourceLocation TypeidLoc, Expr *E, SourceLocation RParenLoc) { StringRef UuidStr; if (!E->getType()->isDependentType()) { if (E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { UuidStr = "00000000-0000-0000-0000-000000000000"; } else { llvm::SmallSetVector UuidAttrs; getUuidAttrOfType(*this, E->getType(), UuidAttrs); if (UuidAttrs.empty()) return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid)); if (UuidAttrs.size() > 1) return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids)); UuidStr = UuidAttrs.back()->getGuid(); } } return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), E, UuidStr, SourceRange(TypeidLoc, RParenLoc)); } /// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression); ExprResult Sema::ActOnCXXUuidof(SourceLocation OpLoc, SourceLocation LParenLoc, bool isType, void *TyOrExpr, SourceLocation RParenLoc) { // If MSVCGuidDecl has not been cached, do the lookup. if (!MSVCGuidDecl) { IdentifierInfo *GuidII = &PP.getIdentifierTable().get("_GUID"); LookupResult R(*this, GuidII, SourceLocation(), LookupTagName); LookupQualifiedName(R, Context.getTranslationUnitDecl()); MSVCGuidDecl = R.getAsSingle(); if (!MSVCGuidDecl) return ExprError(Diag(OpLoc, diag::err_need_header_before_ms_uuidof)); } QualType GuidType = Context.getTypeDeclType(MSVCGuidDecl); if (isType) { // The operand is a type; handle it as such. TypeSourceInfo *TInfo = nullptr; QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr), &TInfo); if (T.isNull()) return ExprError(); if (!TInfo) TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc); return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc); } // The operand is an expression. return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc); } /// ActOnCXXBoolLiteral - Parse {true,false} literals. ExprResult Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) { assert((Kind == tok::kw_true || Kind == tok::kw_false) && "Unknown C++ Boolean value!"); return new (Context) CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc); } /// ActOnCXXNullPtrLiteral - Parse 'nullptr'. ExprResult Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) { return new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc); } /// ActOnCXXThrow - Parse throw expressions. ExprResult Sema::ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *Ex) { bool IsThrownVarInScope = false; if (Ex) { // C++0x [class.copymove]p31: // When certain criteria are met, an implementation is allowed to omit the // copy/move construction of a class object [...] // // - in a throw-expression, when the operand is the name of a // non-volatile automatic object (other than a function or catch- // clause parameter) whose scope does not extend beyond the end of the // innermost enclosing try-block (if there is one), the copy/move // operation from the operand to the exception object (15.1) can be // omitted by constructing the automatic object directly into the // exception object if (DeclRefExpr *DRE = dyn_cast(Ex->IgnoreParens())) if (VarDecl *Var = dyn_cast(DRE->getDecl())) { if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) { for( ; S; S = S->getParent()) { if (S->isDeclScope(Var)) { IsThrownVarInScope = true; break; } if (S->getFlags() & (Scope::FnScope | Scope::ClassScope | Scope::BlockScope | Scope::FunctionPrototypeScope | Scope::ObjCMethodScope | Scope::TryScope)) break; } } } } return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope); } ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex, bool IsThrownVarInScope) { // Don't report an error if 'throw' is used in system headers. if (!getLangOpts().CXXExceptions && !getSourceManager().isInSystemHeader(OpLoc)) Diag(OpLoc, diag::err_exceptions_disabled) << "throw"; if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope()) Diag(OpLoc, diag::err_omp_simd_region_cannot_use_stmt) << "throw"; if (Ex && !Ex->isTypeDependent()) { QualType ExceptionObjectTy = Context.getExceptionObjectType(Ex->getType()); if (CheckCXXThrowOperand(OpLoc, ExceptionObjectTy, Ex)) return ExprError(); // Initialize the exception result. This implicitly weeds out // abstract types or types with inaccessible copy constructors. // C++0x [class.copymove]p31: // When certain criteria are met, an implementation is allowed to omit the // copy/move construction of a class object [...] // // - in a throw-expression, when the operand is the name of a // non-volatile automatic object (other than a function or // catch-clause // parameter) whose scope does not extend beyond the end of the // innermost enclosing try-block (if there is one), the copy/move // operation from the operand to the exception object (15.1) can be // omitted by constructing the automatic object directly into the // exception object const VarDecl *NRVOVariable = nullptr; if (IsThrownVarInScope) NRVOVariable = getCopyElisionCandidate(QualType(), Ex, false); InitializedEntity Entity = InitializedEntity::InitializeException( OpLoc, ExceptionObjectTy, /*NRVO=*/NRVOVariable != nullptr); ExprResult Res = PerformMoveOrCopyInitialization( Entity, NRVOVariable, QualType(), Ex, IsThrownVarInScope); if (Res.isInvalid()) return ExprError(); Ex = Res.get(); } return new (Context) CXXThrowExpr(Ex, Context.VoidTy, OpLoc, IsThrownVarInScope); } static void collectPublicBases(CXXRecordDecl *RD, llvm::DenseMap &SubobjectsSeen, llvm::SmallPtrSetImpl &VBases, llvm::SetVector &PublicSubobjectsSeen, bool ParentIsPublic) { for (const CXXBaseSpecifier &BS : RD->bases()) { CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl(); bool NewSubobject; // Virtual bases constitute the same subobject. Non-virtual bases are // always distinct subobjects. if (BS.isVirtual()) NewSubobject = VBases.insert(BaseDecl).second; else NewSubobject = true; if (NewSubobject) ++SubobjectsSeen[BaseDecl]; // Only add subobjects which have public access throughout the entire chain. bool PublicPath = ParentIsPublic && BS.getAccessSpecifier() == AS_public; if (PublicPath) PublicSubobjectsSeen.insert(BaseDecl); // Recurse on to each base subobject. collectPublicBases(BaseDecl, SubobjectsSeen, VBases, PublicSubobjectsSeen, PublicPath); } } static void getUnambiguousPublicSubobjects( CXXRecordDecl *RD, llvm::SmallVectorImpl &Objects) { llvm::DenseMap SubobjectsSeen; llvm::SmallSet VBases; llvm::SetVector PublicSubobjectsSeen; SubobjectsSeen[RD] = 1; PublicSubobjectsSeen.insert(RD); collectPublicBases(RD, SubobjectsSeen, VBases, PublicSubobjectsSeen, /*ParentIsPublic=*/true); for (CXXRecordDecl *PublicSubobject : PublicSubobjectsSeen) { // Skip ambiguous objects. if (SubobjectsSeen[PublicSubobject] > 1) continue; Objects.push_back(PublicSubobject); } } /// CheckCXXThrowOperand - Validate the operand of a throw. bool Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc, QualType ExceptionObjectTy, Expr *E) { // If the type of the exception would be an incomplete type or a pointer // to an incomplete type other than (cv) void the program is ill-formed. QualType Ty = ExceptionObjectTy; bool isPointer = false; if (const PointerType* Ptr = Ty->getAs()) { Ty = Ptr->getPointeeType(); isPointer = true; } if (!isPointer || !Ty->isVoidType()) { if (RequireCompleteType(ThrowLoc, Ty, isPointer ? diag::err_throw_incomplete_ptr : diag::err_throw_incomplete, E->getSourceRange())) return true; if (RequireNonAbstractType(ThrowLoc, ExceptionObjectTy, diag::err_throw_abstract_type, E)) return true; } // If the exception has class type, we need additional handling. CXXRecordDecl *RD = Ty->getAsCXXRecordDecl(); if (!RD) return false; // If we are throwing a polymorphic class type or pointer thereof, // exception handling will make use of the vtable. MarkVTableUsed(ThrowLoc, RD); // If a pointer is thrown, the referenced object will not be destroyed. if (isPointer) return false; // If the class has a destructor, we must be able to call it. if (!RD->hasIrrelevantDestructor()) { if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) { MarkFunctionReferenced(E->getExprLoc(), Destructor); CheckDestructorAccess(E->getExprLoc(), Destructor, PDiag(diag::err_access_dtor_exception) << Ty); if (DiagnoseUseOfDecl(Destructor, E->getExprLoc())) return true; } } // The MSVC ABI creates a list of all types which can catch the exception // object. This list also references the appropriate copy constructor to call // if the object is caught by value and has a non-trivial copy constructor. if (Context.getTargetInfo().getCXXABI().isMicrosoft()) { // We are only interested in the public, unambiguous bases contained within // the exception object. Bases which are ambiguous or otherwise // inaccessible are not catchable types. llvm::SmallVector UnambiguousPublicSubobjects; getUnambiguousPublicSubobjects(RD, UnambiguousPublicSubobjects); for (CXXRecordDecl *Subobject : UnambiguousPublicSubobjects) { // Attempt to lookup the copy constructor. Various pieces of machinery // will spring into action, like template instantiation, which means this // cannot be a simple walk of the class's decls. Instead, we must perform // lookup and overload resolution. CXXConstructorDecl *CD = LookupCopyingConstructor(Subobject, 0); if (!CD) continue; // Mark the constructor referenced as it is used by this throw expression. MarkFunctionReferenced(E->getExprLoc(), CD); // Skip this copy constructor if it is trivial, we don't need to record it // in the catchable type data. if (CD->isTrivial()) continue; // The copy constructor is non-trivial, create a mapping from this class // type to this constructor. // N.B. The selection of copy constructor is not sensitive to this // particular throw-site. Lookup will be performed at the catch-site to // ensure that the copy constructor is, in fact, accessible (via // friendship or any other means). Context.addCopyConstructorForExceptionObject(Subobject, CD); // We don't keep the instantiated default argument expressions around so // we must rebuild them here. for (unsigned I = 1, E = CD->getNumParams(); I != E; ++I) { // Skip any default arguments that we've already instantiated. if (Context.getDefaultArgExprForConstructor(CD, I)) continue; Expr *DefaultArg = BuildCXXDefaultArgExpr(ThrowLoc, CD, CD->getParamDecl(I)).get(); Context.addDefaultArgExprForConstructor(CD, I, DefaultArg); } } } return false; } static QualType adjustCVQualifiersForCXXThisWithinLambda( ArrayRef FunctionScopes, QualType ThisTy, DeclContext *CurSemaContext, ASTContext &ASTCtx) { QualType ClassType = ThisTy->getPointeeType(); LambdaScopeInfo *CurLSI = nullptr; DeclContext *CurDC = CurSemaContext; // Iterate through the stack of lambdas starting from the innermost lambda to // the outermost lambda, checking if '*this' is ever captured by copy - since // that could change the cv-qualifiers of the '*this' object. // The object referred to by '*this' starts out with the cv-qualifiers of its // member function. We then start with the innermost lambda and iterate // outward checking to see if any lambda performs a by-copy capture of '*this' // - and if so, any nested lambda must respect the 'constness' of that // capturing lamdbda's call operator. // // The issue is that we cannot rely entirely on the FunctionScopeInfo stack // since ScopeInfos are pushed on during parsing and treetransforming. But // since a generic lambda's call operator can be instantiated anywhere (even // end of the TU) we need to be able to examine its enclosing lambdas and so // we use the DeclContext to get a hold of the closure-class and query it for // capture information. The reason we don't just resort to always using the // DeclContext chain is that it is only mature for lambda expressions // enclosing generic lambda's call operators that are being instantiated. for (int I = FunctionScopes.size(); I-- && isa(FunctionScopes[I]); CurDC = getLambdaAwareParentOfDeclContext(CurDC)) { CurLSI = cast(FunctionScopes[I]); if (!CurLSI->isCXXThisCaptured()) continue; auto C = CurLSI->getCXXThisCapture(); if (C.isCopyCapture()) { ClassType.removeLocalCVRQualifiers(Qualifiers::CVRMask); if (CurLSI->CallOperator->isConst()) ClassType.addConst(); return ASTCtx.getPointerType(ClassType); } } // We've run out of ScopeInfos but check if CurDC is a lambda (which can // happen during instantiation of generic lambdas) if (isLambdaCallOperator(CurDC)) { assert(CurLSI); assert(isGenericLambdaCallOperatorSpecialization(CurLSI->CallOperator)); assert(CurDC == getLambdaAwareParentOfDeclContext(CurLSI->CallOperator)); auto IsThisCaptured = [](CXXRecordDecl *Closure, bool &IsByCopy, bool &IsConst) { IsConst = false; IsByCopy = false; for (auto &&C : Closure->captures()) { if (C.capturesThis()) { if (C.getCaptureKind() == LCK_StarThis) IsByCopy = true; if (Closure->getLambdaCallOperator()->isConst()) IsConst = true; return true; } } return false; }; bool IsByCopyCapture = false; bool IsConstCapture = false; CXXRecordDecl *Closure = cast(CurDC->getParent()); while (Closure && IsThisCaptured(Closure, IsByCopyCapture, IsConstCapture)) { if (IsByCopyCapture) { ClassType.removeLocalCVRQualifiers(Qualifiers::CVRMask); if (IsConstCapture) ClassType.addConst(); return ASTCtx.getPointerType(ClassType); } Closure = isLambdaCallOperator(Closure->getParent()) ? cast(Closure->getParent()->getParent()) : nullptr; } } return ASTCtx.getPointerType(ClassType); } QualType Sema::getCurrentThisType() { DeclContext *DC = getFunctionLevelDeclContext(); QualType ThisTy = CXXThisTypeOverride; if (CXXMethodDecl *method = dyn_cast(DC)) { if (method && method->isInstance()) ThisTy = method->getThisType(Context); } if (ThisTy.isNull()) { if (isGenericLambdaCallOperatorSpecialization(CurContext) && CurContext->getParent()->getParent()->isRecord()) { // This is a generic lambda call operator that is being instantiated // within a default initializer - so use the enclosing class as 'this'. // There is no enclosing member function to retrieve the 'this' pointer // from. // FIXME: This looks wrong. If we're in a lambda within a lambda within a // default member initializer, we need to recurse up more parents to find // the right context. Looks like we should be walking up to the parent of // the closure type, checking whether that is itself a lambda, and if so, // recursing, until we reach a class or a function that isn't a lambda // call operator. And we should accumulate the constness of *this on the // way. QualType ClassTy = Context.getTypeDeclType( cast(CurContext->getParent()->getParent())); // There are no cv-qualifiers for 'this' within default initializers, // per [expr.prim.general]p4. ThisTy = Context.getPointerType(ClassTy); } } // If we are within a lambda's call operator, the cv-qualifiers of 'this' // might need to be adjusted if the lambda or any of its enclosing lambda's // captures '*this' by copy. if (!ThisTy.isNull() && isLambdaCallOperator(CurContext)) return adjustCVQualifiersForCXXThisWithinLambda(FunctionScopes, ThisTy, CurContext, Context); return ThisTy; } Sema::CXXThisScopeRAII::CXXThisScopeRAII(Sema &S, Decl *ContextDecl, unsigned CXXThisTypeQuals, bool Enabled) : S(S), OldCXXThisTypeOverride(S.CXXThisTypeOverride), Enabled(false) { if (!Enabled || !ContextDecl) return; CXXRecordDecl *Record = nullptr; if (ClassTemplateDecl *Template = dyn_cast(ContextDecl)) Record = Template->getTemplatedDecl(); else Record = cast(ContextDecl); // We care only for CVR qualifiers here, so cut everything else. CXXThisTypeQuals &= Qualifiers::FastMask; S.CXXThisTypeOverride = S.Context.getPointerType( S.Context.getRecordType(Record).withCVRQualifiers(CXXThisTypeQuals)); this->Enabled = true; } Sema::CXXThisScopeRAII::~CXXThisScopeRAII() { if (Enabled) { S.CXXThisTypeOverride = OldCXXThisTypeOverride; } } static Expr *captureThis(Sema &S, ASTContext &Context, RecordDecl *RD, QualType ThisTy, SourceLocation Loc, const bool ByCopy) { QualType AdjustedThisTy = ThisTy; // The type of the corresponding data member (not a 'this' pointer if 'by // copy'). QualType CaptureThisFieldTy = ThisTy; if (ByCopy) { // If we are capturing the object referred to by '*this' by copy, ignore any // cv qualifiers inherited from the type of the member function for the type // of the closure-type's corresponding data member and any use of 'this'. CaptureThisFieldTy = ThisTy->getPointeeType(); CaptureThisFieldTy.removeLocalCVRQualifiers(Qualifiers::CVRMask); AdjustedThisTy = Context.getPointerType(CaptureThisFieldTy); } FieldDecl *Field = FieldDecl::Create( Context, RD, Loc, Loc, nullptr, CaptureThisFieldTy, Context.getTrivialTypeSourceInfo(CaptureThisFieldTy, Loc), nullptr, false, ICIS_NoInit); Field->setImplicit(true); Field->setAccess(AS_private); RD->addDecl(Field); Expr *This = new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit*/ true); if (ByCopy) { Expr *StarThis = S.CreateBuiltinUnaryOp(Loc, UO_Deref, This).get(); InitializedEntity Entity = InitializedEntity::InitializeLambdaCapture( nullptr, CaptureThisFieldTy, Loc); InitializationKind InitKind = InitializationKind::CreateDirect(Loc, Loc, Loc); InitializationSequence Init(S, Entity, InitKind, StarThis); ExprResult ER = Init.Perform(S, Entity, InitKind, StarThis); if (ER.isInvalid()) return nullptr; return ER.get(); } return This; } bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit, bool BuildAndDiagnose, const unsigned *const FunctionScopeIndexToStopAt, const bool ByCopy) { // We don't need to capture this in an unevaluated context. if (isUnevaluatedContext() && !Explicit) return true; assert((!ByCopy || Explicit) && "cannot implicitly capture *this by value"); const unsigned MaxFunctionScopesIndex = FunctionScopeIndexToStopAt ? *FunctionScopeIndexToStopAt : FunctionScopes.size() - 1; // Check that we can capture the *enclosing object* (referred to by '*this') // by the capturing-entity/closure (lambda/block/etc) at // MaxFunctionScopesIndex-deep on the FunctionScopes stack. // Note: The *enclosing object* can only be captured by-value by a // closure that is a lambda, using the explicit notation: // [*this] { ... }. // Every other capture of the *enclosing object* results in its by-reference // capture. // For a closure 'L' (at MaxFunctionScopesIndex in the FunctionScopes // stack), we can capture the *enclosing object* only if: // - 'L' has an explicit byref or byval capture of the *enclosing object* // - or, 'L' has an implicit capture. // AND // -- there is no enclosing closure // -- or, there is some enclosing closure 'E' that has already captured the // *enclosing object*, and every intervening closure (if any) between 'E' // and 'L' can implicitly capture the *enclosing object*. // -- or, every enclosing closure can implicitly capture the // *enclosing object* unsigned NumCapturingClosures = 0; for (unsigned idx = MaxFunctionScopesIndex; idx != 0; idx--) { if (CapturingScopeInfo *CSI = dyn_cast(FunctionScopes[idx])) { if (CSI->CXXThisCaptureIndex != 0) { // 'this' is already being captured; there isn't anything more to do. break; } LambdaScopeInfo *LSI = dyn_cast(CSI); if (LSI && isGenericLambdaCallOperatorSpecialization(LSI->CallOperator)) { // This context can't implicitly capture 'this'; fail out. if (BuildAndDiagnose) Diag(Loc, diag::err_this_capture) << (Explicit && idx == MaxFunctionScopesIndex); return true; } if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref || CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval || CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block || CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_CapturedRegion || (Explicit && idx == MaxFunctionScopesIndex)) { // Regarding (Explicit && idx == MaxFunctionScopesIndex): only the first // iteration through can be an explicit capture, all enclosing closures, // if any, must perform implicit captures. // This closure can capture 'this'; continue looking upwards. NumCapturingClosures++; continue; } // This context can't implicitly capture 'this'; fail out. if (BuildAndDiagnose) Diag(Loc, diag::err_this_capture) << (Explicit && idx == MaxFunctionScopesIndex); return true; } break; } if (!BuildAndDiagnose) return false; // If we got here, then the closure at MaxFunctionScopesIndex on the // FunctionScopes stack, can capture the *enclosing object*, so capture it // (including implicit by-reference captures in any enclosing closures). // In the loop below, respect the ByCopy flag only for the closure requesting // the capture (i.e. first iteration through the loop below). Ignore it for // all enclosing closure's upto NumCapturingClosures (since they must be // implicitly capturing the *enclosing object* by reference (see loop // above)). assert((!ByCopy || dyn_cast(FunctionScopes[MaxFunctionScopesIndex])) && "Only a lambda can capture the enclosing object (referred to by " "*this) by copy"); // FIXME: We need to delay this marking in PotentiallyPotentiallyEvaluated // contexts. QualType ThisTy = getCurrentThisType(); for (unsigned idx = MaxFunctionScopesIndex; NumCapturingClosures; --idx, --NumCapturingClosures) { CapturingScopeInfo *CSI = cast(FunctionScopes[idx]); Expr *ThisExpr = nullptr; if (LambdaScopeInfo *LSI = dyn_cast(CSI)) { // For lambda expressions, build a field and an initializing expression, // and capture the *enclosing object* by copy only if this is the first // iteration. ThisExpr = captureThis(*this, Context, LSI->Lambda, ThisTy, Loc, ByCopy && idx == MaxFunctionScopesIndex); } else if (CapturedRegionScopeInfo *RSI = dyn_cast(FunctionScopes[idx])) ThisExpr = captureThis(*this, Context, RSI->TheRecordDecl, ThisTy, Loc, false/*ByCopy*/); bool isNested = NumCapturingClosures > 1; CSI->addThisCapture(isNested, Loc, ThisExpr, ByCopy); } return false; } ExprResult Sema::ActOnCXXThis(SourceLocation Loc) { /// C++ 9.3.2: In the body of a non-static member function, the keyword this /// is a non-lvalue expression whose value is the address of the object for /// which the function is called. QualType ThisTy = getCurrentThisType(); if (ThisTy.isNull()) return Diag(Loc, diag::err_invalid_this_use); CheckCXXThisCapture(Loc); return new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit=*/false); } bool Sema::isThisOutsideMemberFunctionBody(QualType BaseType) { // If we're outside the body of a member function, then we'll have a specified // type for 'this'. if (CXXThisTypeOverride.isNull()) return false; // Determine whether we're looking into a class that's currently being // defined. CXXRecordDecl *Class = BaseType->getAsCXXRecordDecl(); return Class && Class->isBeingDefined(); } ExprResult Sema::ActOnCXXTypeConstructExpr(ParsedType TypeRep, SourceLocation LParenLoc, MultiExprArg exprs, SourceLocation RParenLoc) { if (!TypeRep) return ExprError(); TypeSourceInfo *TInfo; QualType Ty = GetTypeFromParser(TypeRep, &TInfo); if (!TInfo) TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation()); auto Result = BuildCXXTypeConstructExpr(TInfo, LParenLoc, exprs, RParenLoc); // Avoid creating a non-type-dependent expression that contains typos. // Non-type-dependent expressions are liable to be discarded without // checking for embedded typos. if (!Result.isInvalid() && Result.get()->isInstantiationDependent() && !Result.get()->isTypeDependent()) Result = CorrectDelayedTyposInExpr(Result.get()); return Result; } /// ActOnCXXTypeConstructExpr - Parse construction of a specified type. /// Can be interpreted either as function-style casting ("int(x)") /// or class type construction ("ClassType(x,y,z)") /// or creation of a value-initialized type ("int()"). ExprResult Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo, SourceLocation LParenLoc, MultiExprArg Exprs, SourceLocation RParenLoc) { QualType Ty = TInfo->getType(); SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc(); if (Ty->isDependentType() || CallExpr::hasAnyTypeDependentArguments(Exprs)) { return CXXUnresolvedConstructExpr::Create(Context, TInfo, LParenLoc, Exprs, RParenLoc); } bool ListInitialization = LParenLoc.isInvalid(); assert((!ListInitialization || (Exprs.size() == 1 && isa(Exprs[0]))) && "List initialization must have initializer list as expression."); SourceRange FullRange = SourceRange(TyBeginLoc, ListInitialization ? Exprs[0]->getSourceRange().getEnd() : RParenLoc); // C++ [expr.type.conv]p1: // If the expression list is a single expression, the type conversion // expression is equivalent (in definedness, and if defined in meaning) to the // corresponding cast expression. if (Exprs.size() == 1 && !ListInitialization) { Expr *Arg = Exprs[0]; return BuildCXXFunctionalCastExpr(TInfo, LParenLoc, Arg, RParenLoc); } // C++14 [expr.type.conv]p2: The expression T(), where T is a // simple-type-specifier or typename-specifier for a non-array complete // object type or the (possibly cv-qualified) void type, creates a prvalue // of the specified type, whose value is that produced by value-initializing // an object of type T. QualType ElemTy = Ty; if (Ty->isArrayType()) { if (!ListInitialization) return ExprError(Diag(TyBeginLoc, diag::err_value_init_for_array_type) << FullRange); ElemTy = Context.getBaseElementType(Ty); } if (!ListInitialization && Ty->isFunctionType()) return ExprError(Diag(TyBeginLoc, diag::err_value_init_for_function_type) << FullRange); if (!Ty->isVoidType() && RequireCompleteType(TyBeginLoc, ElemTy, diag::err_invalid_incomplete_type_use, FullRange)) return ExprError(); if (RequireNonAbstractType(TyBeginLoc, Ty, diag::err_allocation_of_abstract_type)) return ExprError(); InitializedEntity Entity = InitializedEntity::InitializeTemporary(TInfo); InitializationKind Kind = Exprs.size() ? ListInitialization ? InitializationKind::CreateDirectList(TyBeginLoc) : InitializationKind::CreateDirect(TyBeginLoc, LParenLoc, RParenLoc) : InitializationKind::CreateValue(TyBeginLoc, LParenLoc, RParenLoc); InitializationSequence InitSeq(*this, Entity, Kind, Exprs); ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs); if (Result.isInvalid() || !ListInitialization) return Result; Expr *Inner = Result.get(); if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null(Inner)) Inner = BTE->getSubExpr(); if (!isa(Inner)) { // If we created a CXXTemporaryObjectExpr, that node also represents the // functional cast. Otherwise, create an explicit cast to represent // the syntactic form of a functional-style cast that was used here. // // FIXME: Creating a CXXFunctionalCastExpr around a CXXConstructExpr // would give a more consistent AST representation than using a // CXXTemporaryObjectExpr. It's also weird that the functional cast // is sometimes handled by initialization and sometimes not. QualType ResultType = Result.get()->getType(); Result = CXXFunctionalCastExpr::Create( Context, ResultType, Expr::getValueKindForType(TInfo->getType()), TInfo, CK_NoOp, Result.get(), /*Path=*/nullptr, LParenLoc, RParenLoc); } return Result; } /// doesUsualArrayDeleteWantSize - Answers whether the usual /// operator delete[] for the given type has a size_t parameter. static bool doesUsualArrayDeleteWantSize(Sema &S, SourceLocation loc, QualType allocType) { const RecordType *record = allocType->getBaseElementTypeUnsafe()->getAs(); if (!record) return false; // Try to find an operator delete[] in class scope. DeclarationName deleteName = S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete); LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName); S.LookupQualifiedName(ops, record->getDecl()); // We're just doing this for information. ops.suppressDiagnostics(); // Very likely: there's no operator delete[]. if (ops.empty()) return false; // If it's ambiguous, it should be illegal to call operator delete[] // on this thing, so it doesn't matter if we allocate extra space or not. if (ops.isAmbiguous()) return false; LookupResult::Filter filter = ops.makeFilter(); while (filter.hasNext()) { NamedDecl *del = filter.next()->getUnderlyingDecl(); // C++0x [basic.stc.dynamic.deallocation]p2: // A template instance is never a usual deallocation function, // regardless of its signature. if (isa(del)) { filter.erase(); continue; } // C++0x [basic.stc.dynamic.deallocation]p2: // If class T does not declare [an operator delete[] with one // parameter] but does declare a member deallocation function // named operator delete[] with exactly two parameters, the // second of which has type std::size_t, then this function // is a usual deallocation function. if (!cast(del)->isUsualDeallocationFunction()) { filter.erase(); continue; } } filter.done(); if (!ops.isSingleResult()) return false; const FunctionDecl *del = cast(ops.getFoundDecl()); return (del->getNumParams() == 2); } /// \brief Parsed a C++ 'new' expression (C++ 5.3.4). /// /// E.g.: /// @code new (memory) int[size][4] @endcode /// or /// @code ::new Foo(23, "hello") @endcode /// /// \param StartLoc The first location of the expression. /// \param UseGlobal True if 'new' was prefixed with '::'. /// \param PlacementLParen Opening paren of the placement arguments. /// \param PlacementArgs Placement new arguments. /// \param PlacementRParen Closing paren of the placement arguments. /// \param TypeIdParens If the type is in parens, the source range. /// \param D The type to be allocated, as well as array dimensions. /// \param Initializer The initializing expression or initializer-list, or null /// if there is none. ExprResult Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal, SourceLocation PlacementLParen, MultiExprArg PlacementArgs, SourceLocation PlacementRParen, SourceRange TypeIdParens, Declarator &D, Expr *Initializer) { bool TypeContainsAuto = D.getDeclSpec().containsPlaceholderType(); Expr *ArraySize = nullptr; // If the specified type is an array, unwrap it and save the expression. if (D.getNumTypeObjects() > 0 && D.getTypeObject(0).Kind == DeclaratorChunk::Array) { DeclaratorChunk &Chunk = D.getTypeObject(0); if (TypeContainsAuto) return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto) << D.getSourceRange()); if (Chunk.Arr.hasStatic) return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new) << D.getSourceRange()); if (!Chunk.Arr.NumElts) return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size) << D.getSourceRange()); ArraySize = static_cast(Chunk.Arr.NumElts); D.DropFirstTypeObject(); } // Every dimension shall be of constant size. if (ArraySize) { for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) { if (D.getTypeObject(I).Kind != DeclaratorChunk::Array) break; DeclaratorChunk::ArrayTypeInfo &Array = D.getTypeObject(I).Arr; if (Expr *NumElts = (Expr *)Array.NumElts) { if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) { if (getLangOpts().CPlusPlus14) { // C++1y [expr.new]p6: Every constant-expression in a noptr-new-declarator // shall be a converted constant expression (5.19) of type std::size_t // and shall evaluate to a strictly positive value. unsigned IntWidth = Context.getTargetInfo().getIntWidth(); assert(IntWidth && "Builtin type of size 0?"); llvm::APSInt Value(IntWidth); Array.NumElts = CheckConvertedConstantExpression(NumElts, Context.getSizeType(), Value, CCEK_NewExpr) .get(); } else { Array.NumElts = VerifyIntegerConstantExpression(NumElts, nullptr, diag::err_new_array_nonconst) .get(); } if (!Array.NumElts) return ExprError(); } } } } TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/nullptr); QualType AllocType = TInfo->getType(); if (D.isInvalidType()) return ExprError(); SourceRange DirectInitRange; if (ParenListExpr *List = dyn_cast_or_null(Initializer)) DirectInitRange = List->getSourceRange(); return BuildCXXNew(SourceRange(StartLoc, D.getLocEnd()), UseGlobal, PlacementLParen, PlacementArgs, PlacementRParen, TypeIdParens, AllocType, TInfo, ArraySize, DirectInitRange, Initializer, TypeContainsAuto); } static bool isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style, Expr *Init) { if (!Init) return true; if (ParenListExpr *PLE = dyn_cast(Init)) return PLE->getNumExprs() == 0; if (isa(Init)) return true; else if (CXXConstructExpr *CCE = dyn_cast(Init)) return !CCE->isListInitialization() && CCE->getConstructor()->isDefaultConstructor(); else if (Style == CXXNewExpr::ListInit) { assert(isa(Init) && "Shouldn't create list CXXConstructExprs for arrays."); return true; } return false; } ExprResult Sema::BuildCXXNew(SourceRange Range, bool UseGlobal, SourceLocation PlacementLParen, MultiExprArg PlacementArgs, SourceLocation PlacementRParen, SourceRange TypeIdParens, QualType AllocType, TypeSourceInfo *AllocTypeInfo, Expr *ArraySize, SourceRange DirectInitRange, Expr *Initializer, bool TypeMayContainAuto) { SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange(); SourceLocation StartLoc = Range.getBegin(); CXXNewExpr::InitializationStyle initStyle; if (DirectInitRange.isValid()) { assert(Initializer && "Have parens but no initializer."); initStyle = CXXNewExpr::CallInit; } else if (Initializer && isa(Initializer)) initStyle = CXXNewExpr::ListInit; else { assert((!Initializer || isa(Initializer) || isa(Initializer)) && "Initializer expression that cannot have been implicitly created."); initStyle = CXXNewExpr::NoInit; } Expr **Inits = &Initializer; unsigned NumInits = Initializer ? 1 : 0; if (ParenListExpr *List = dyn_cast_or_null(Initializer)) { assert(initStyle == CXXNewExpr::CallInit && "paren init for non-call init"); Inits = List->getExprs(); NumInits = List->getNumExprs(); } // C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for. if (TypeMayContainAuto && AllocType->isUndeducedType()) { if (initStyle == CXXNewExpr::NoInit || NumInits == 0) return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg) << AllocType << TypeRange); if (initStyle == CXXNewExpr::ListInit || (NumInits == 1 && isa(Inits[0]))) return ExprError(Diag(Inits[0]->getLocStart(), diag::err_auto_new_list_init) << AllocType << TypeRange); if (NumInits > 1) { Expr *FirstBad = Inits[1]; return ExprError(Diag(FirstBad->getLocStart(), diag::err_auto_new_ctor_multiple_expressions) << AllocType << TypeRange); } Expr *Deduce = Inits[0]; QualType DeducedType; if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == DAR_Failed) return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure) << AllocType << Deduce->getType() << TypeRange << Deduce->getSourceRange()); if (DeducedType.isNull()) return ExprError(); AllocType = DeducedType; } // Per C++0x [expr.new]p5, the type being constructed may be a // typedef of an array type. if (!ArraySize) { if (const ConstantArrayType *Array = Context.getAsConstantArrayType(AllocType)) { ArraySize = IntegerLiteral::Create(Context, Array->getSize(), Context.getSizeType(), TypeRange.getEnd()); AllocType = Array->getElementType(); } } if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange)) return ExprError(); if (initStyle == CXXNewExpr::ListInit && isStdInitializerList(AllocType, nullptr)) { Diag(AllocTypeInfo->getTypeLoc().getBeginLoc(), diag::warn_dangling_std_initializer_list) << /*at end of FE*/0 << Inits[0]->getSourceRange(); } // In ARC, infer 'retaining' for the allocated if (getLangOpts().ObjCAutoRefCount && AllocType.getObjCLifetime() == Qualifiers::OCL_None && AllocType->isObjCLifetimeType()) { AllocType = Context.getLifetimeQualifiedType(AllocType, AllocType->getObjCARCImplicitLifetime()); } QualType ResultType = Context.getPointerType(AllocType); if (ArraySize && ArraySize->getType()->isNonOverloadPlaceholderType()) { ExprResult result = CheckPlaceholderExpr(ArraySize); if (result.isInvalid()) return ExprError(); ArraySize = result.get(); } // C++98 5.3.4p6: "The expression in a direct-new-declarator shall have // integral or enumeration type with a non-negative value." // C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped // enumeration type, or a class type for which a single non-explicit // conversion function to integral or unscoped enumeration type exists. // C++1y [expr.new]p6: The expression [...] is implicitly converted to // std::size_t. if (ArraySize && !ArraySize->isTypeDependent()) { ExprResult ConvertedSize; if (getLangOpts().CPlusPlus14) { assert(Context.getTargetInfo().getIntWidth() && "Builtin type of size 0?"); ConvertedSize = PerformImplicitConversion(ArraySize, Context.getSizeType(), AA_Converting); if (!ConvertedSize.isInvalid() && ArraySize->getType()->getAs()) // Diagnose the compatibility of this conversion. Diag(StartLoc, diag::warn_cxx98_compat_array_size_conversion) << ArraySize->getType() << 0 << "'size_t'"; } else { class SizeConvertDiagnoser : public ICEConvertDiagnoser { protected: Expr *ArraySize; public: SizeConvertDiagnoser(Expr *ArraySize) : ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, false, false), ArraySize(ArraySize) {} SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc, QualType T) override { return S.Diag(Loc, diag::err_array_size_not_integral) << S.getLangOpts().CPlusPlus11 << T; } SemaDiagnosticBuilder diagnoseIncomplete( Sema &S, SourceLocation Loc, QualType T) override { return S.Diag(Loc, diag::err_array_size_incomplete_type) << T << ArraySize->getSourceRange(); } SemaDiagnosticBuilder diagnoseExplicitConv( Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { return S.Diag(Loc, diag::err_array_size_explicit_conversion) << T << ConvTy; } SemaDiagnosticBuilder noteExplicitConv( Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { return S.Diag(Conv->getLocation(), diag::note_array_size_conversion) << ConvTy->isEnumeralType() << ConvTy; } SemaDiagnosticBuilder diagnoseAmbiguous( Sema &S, SourceLocation Loc, QualType T) override { return S.Diag(Loc, diag::err_array_size_ambiguous_conversion) << T; } SemaDiagnosticBuilder noteAmbiguous( Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { return S.Diag(Conv->getLocation(), diag::note_array_size_conversion) << ConvTy->isEnumeralType() << ConvTy; } SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { return S.Diag(Loc, S.getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_array_size_conversion : diag::ext_array_size_conversion) << T << ConvTy->isEnumeralType() << ConvTy; } } SizeDiagnoser(ArraySize); ConvertedSize = PerformContextualImplicitConversion(StartLoc, ArraySize, SizeDiagnoser); } if (ConvertedSize.isInvalid()) return ExprError(); ArraySize = ConvertedSize.get(); QualType SizeType = ArraySize->getType(); if (!SizeType->isIntegralOrUnscopedEnumerationType()) return ExprError(); // C++98 [expr.new]p7: // The expression in a direct-new-declarator shall have integral type // with a non-negative value. // // Let's see if this is a constant < 0. If so, we reject it out of // hand. Otherwise, if it's not a constant, we must have an unparenthesized // array type. // // Note: such a construct has well-defined semantics in C++11: it throws // std::bad_array_new_length. if (!ArraySize->isValueDependent()) { llvm::APSInt Value; // We've already performed any required implicit conversion to integer or // unscoped enumeration type. if (ArraySize->isIntegerConstantExpr(Value, Context)) { if (Value < llvm::APSInt( llvm::APInt::getNullValue(Value.getBitWidth()), Value.isUnsigned())) { if (getLangOpts().CPlusPlus11) Diag(ArraySize->getLocStart(), diag::warn_typecheck_negative_array_new_size) << ArraySize->getSourceRange(); else return ExprError(Diag(ArraySize->getLocStart(), diag::err_typecheck_negative_array_size) << ArraySize->getSourceRange()); } else if (!AllocType->isDependentType()) { unsigned ActiveSizeBits = ConstantArrayType::getNumAddressingBits(Context, AllocType, Value); if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) { if (getLangOpts().CPlusPlus11) Diag(ArraySize->getLocStart(), diag::warn_array_new_too_large) << Value.toString(10) << ArraySize->getSourceRange(); else return ExprError(Diag(ArraySize->getLocStart(), diag::err_array_too_large) << Value.toString(10) << ArraySize->getSourceRange()); } } } else if (TypeIdParens.isValid()) { // Can't have dynamic array size when the type-id is in parentheses. Diag(ArraySize->getLocStart(), diag::ext_new_paren_array_nonconst) << ArraySize->getSourceRange() << FixItHint::CreateRemoval(TypeIdParens.getBegin()) << FixItHint::CreateRemoval(TypeIdParens.getEnd()); TypeIdParens = SourceRange(); } } // Note that we do *not* convert the argument in any way. It can // be signed, larger than size_t, whatever. } FunctionDecl *OperatorNew = nullptr; FunctionDecl *OperatorDelete = nullptr; if (!AllocType->isDependentType() && !Expr::hasAnyTypeDependentArguments(PlacementArgs) && FindAllocationFunctions(StartLoc, SourceRange(PlacementLParen, PlacementRParen), UseGlobal, AllocType, ArraySize, PlacementArgs, OperatorNew, OperatorDelete)) return ExprError(); // If this is an array allocation, compute whether the usual array // deallocation function for the type has a size_t parameter. bool UsualArrayDeleteWantsSize = false; if (ArraySize && !AllocType->isDependentType()) UsualArrayDeleteWantsSize = doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType); SmallVector AllPlaceArgs; if (OperatorNew) { const FunctionProtoType *Proto = OperatorNew->getType()->getAs(); VariadicCallType CallType = Proto->isVariadic() ? VariadicFunction : VariadicDoesNotApply; // We've already converted the placement args, just fill in any default // arguments. Skip the first parameter because we don't have a corresponding // argument. if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto, 1, PlacementArgs, AllPlaceArgs, CallType)) return ExprError(); if (!AllPlaceArgs.empty()) PlacementArgs = AllPlaceArgs; // FIXME: This is wrong: PlacementArgs misses out the first (size) argument. DiagnoseSentinelCalls(OperatorNew, PlacementLParen, PlacementArgs); // FIXME: Missing call to CheckFunctionCall or equivalent } // Warn if the type is over-aligned and is being allocated by global operator // new. if (PlacementArgs.empty() && OperatorNew && (OperatorNew->isImplicit() || (OperatorNew->getLocStart().isValid() && getSourceManager().isInSystemHeader(OperatorNew->getLocStart())))) { if (unsigned Align = Context.getPreferredTypeAlign(AllocType.getTypePtr())){ unsigned SuitableAlign = Context.getTargetInfo().getSuitableAlign(); if (Align > SuitableAlign) Diag(StartLoc, diag::warn_overaligned_type) << AllocType << unsigned(Align / Context.getCharWidth()) << unsigned(SuitableAlign / Context.getCharWidth()); } } QualType InitType = AllocType; // Array 'new' can't have any initializers except empty parentheses. // Initializer lists are also allowed, in C++11. Rely on the parser for the // dialect distinction. if (ResultType->isArrayType() || ArraySize) { if (!isLegalArrayNewInitializer(initStyle, Initializer)) { SourceRange InitRange(Inits[0]->getLocStart(), Inits[NumInits - 1]->getLocEnd()); Diag(StartLoc, diag::err_new_array_init_args) << InitRange; return ExprError(); } if (InitListExpr *ILE = dyn_cast_or_null(Initializer)) { // We do the initialization typechecking against the array type // corresponding to the number of initializers + 1 (to also check // default-initialization). unsigned NumElements = ILE->getNumInits() + 1; InitType = Context.getConstantArrayType(AllocType, llvm::APInt(Context.getTypeSize(Context.getSizeType()), NumElements), ArrayType::Normal, 0); } } // If we can perform the initialization, and we've not already done so, // do it now. if (!AllocType->isDependentType() && !Expr::hasAnyTypeDependentArguments( llvm::makeArrayRef(Inits, NumInits))) { // C++11 [expr.new]p15: // A new-expression that creates an object of type T initializes that // object as follows: InitializationKind Kind // - If the new-initializer is omitted, the object is default- // initialized (8.5); if no initialization is performed, // the object has indeterminate value = initStyle == CXXNewExpr::NoInit ? InitializationKind::CreateDefault(TypeRange.getBegin()) // - Otherwise, the new-initializer is interpreted according to the // initialization rules of 8.5 for direct-initialization. : initStyle == CXXNewExpr::ListInit ? InitializationKind::CreateDirectList(TypeRange.getBegin()) : InitializationKind::CreateDirect(TypeRange.getBegin(), DirectInitRange.getBegin(), DirectInitRange.getEnd()); InitializedEntity Entity = InitializedEntity::InitializeNew(StartLoc, InitType); InitializationSequence InitSeq(*this, Entity, Kind, MultiExprArg(Inits, NumInits)); ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind, MultiExprArg(Inits, NumInits)); if (FullInit.isInvalid()) return ExprError(); // FullInit is our initializer; strip off CXXBindTemporaryExprs, because // we don't want the initialized object to be destructed. if (CXXBindTemporaryExpr *Binder = dyn_cast_or_null(FullInit.get())) FullInit = Binder->getSubExpr(); Initializer = FullInit.get(); } // Mark the new and delete operators as referenced. if (OperatorNew) { if (DiagnoseUseOfDecl(OperatorNew, StartLoc)) return ExprError(); MarkFunctionReferenced(StartLoc, OperatorNew); } if (OperatorDelete) { if (DiagnoseUseOfDecl(OperatorDelete, StartLoc)) return ExprError(); MarkFunctionReferenced(StartLoc, OperatorDelete); } // C++0x [expr.new]p17: // If the new expression creates an array of objects of class type, // access and ambiguity control are done for the destructor. QualType BaseAllocType = Context.getBaseElementType(AllocType); if (ArraySize && !BaseAllocType->isDependentType()) { if (const RecordType *BaseRecordType = BaseAllocType->getAs()) { if (CXXDestructorDecl *dtor = LookupDestructor( cast(BaseRecordType->getDecl()))) { MarkFunctionReferenced(StartLoc, dtor); CheckDestructorAccess(StartLoc, dtor, PDiag(diag::err_access_dtor) << BaseAllocType); if (DiagnoseUseOfDecl(dtor, StartLoc)) return ExprError(); } } } return new (Context) CXXNewExpr(Context, UseGlobal, OperatorNew, OperatorDelete, UsualArrayDeleteWantsSize, PlacementArgs, TypeIdParens, ArraySize, initStyle, Initializer, ResultType, AllocTypeInfo, Range, DirectInitRange); } /// \brief Checks that a type is suitable as the allocated type /// in a new-expression. bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc, SourceRange R) { // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an // abstract class type or array thereof. if (AllocType->isFunctionType()) return Diag(Loc, diag::err_bad_new_type) << AllocType << 0 << R; else if (AllocType->isReferenceType()) return Diag(Loc, diag::err_bad_new_type) << AllocType << 1 << R; else if (!AllocType->isDependentType() && RequireCompleteType(Loc, AllocType, diag::err_new_incomplete_type,R)) return true; else if (RequireNonAbstractType(Loc, AllocType, diag::err_allocation_of_abstract_type)) return true; else if (AllocType->isVariablyModifiedType()) return Diag(Loc, diag::err_variably_modified_new_type) << AllocType; else if (unsigned AddressSpace = AllocType.getAddressSpace()) return Diag(Loc, diag::err_address_space_qualified_new) << AllocType.getUnqualifiedType() << AddressSpace; else if (getLangOpts().ObjCAutoRefCount) { if (const ArrayType *AT = Context.getAsArrayType(AllocType)) { QualType BaseAllocType = Context.getBaseElementType(AT); if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None && BaseAllocType->isObjCLifetimeType()) return Diag(Loc, diag::err_arc_new_array_without_ownership) << BaseAllocType; } } return false; } /// \brief Determine whether the given function is a non-placement /// deallocation function. static bool isNonPlacementDeallocationFunction(Sema &S, FunctionDecl *FD) { if (FD->isInvalidDecl()) return false; if (CXXMethodDecl *Method = dyn_cast(FD)) return Method->isUsualDeallocationFunction(); if (FD->getOverloadedOperator() != OO_Delete && FD->getOverloadedOperator() != OO_Array_Delete) return false; if (FD->getNumParams() == 1) return true; return S.getLangOpts().SizedDeallocation && FD->getNumParams() == 2 && S.Context.hasSameUnqualifiedType(FD->getParamDecl(1)->getType(), S.Context.getSizeType()); } /// FindAllocationFunctions - Finds the overloads of operator new and delete /// that are appropriate for the allocation. bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range, bool UseGlobal, QualType AllocType, bool IsArray, MultiExprArg PlaceArgs, FunctionDecl *&OperatorNew, FunctionDecl *&OperatorDelete) { // --- Choosing an allocation function --- // C++ 5.3.4p8 - 14 & 18 // 1) If UseGlobal is true, only look in the global scope. Else, also look // in the scope of the allocated class. // 2) If an array size is given, look for operator new[], else look for // operator new. // 3) The first argument is always size_t. Append the arguments from the // placement form. SmallVector AllocArgs(1 + PlaceArgs.size()); // We don't care about the actual value of this argument. // FIXME: Should the Sema create the expression and embed it in the syntax // tree? Or should the consumer just recalculate the value? IntegerLiteral Size(Context, llvm::APInt::getNullValue( Context.getTargetInfo().getPointerWidth(0)), Context.getSizeType(), SourceLocation()); AllocArgs[0] = &Size; std::copy(PlaceArgs.begin(), PlaceArgs.end(), AllocArgs.begin() + 1); // C++ [expr.new]p8: // If the allocated type is a non-array type, the allocation // function's name is operator new and the deallocation function's // name is operator delete. If the allocated type is an array // type, the allocation function's name is operator new[] and the // deallocation function's name is operator delete[]. DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName( IsArray ? OO_Array_New : OO_New); DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( IsArray ? OO_Array_Delete : OO_Delete); QualType AllocElemType = Context.getBaseElementType(AllocType); if (AllocElemType->isRecordType() && !UseGlobal) { CXXRecordDecl *Record = cast(AllocElemType->getAs()->getDecl()); if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, Record, /*AllowMissing=*/true, OperatorNew)) return true; } if (!OperatorNew) { // Didn't find a member overload. Look for a global one. DeclareGlobalNewDelete(); DeclContext *TUDecl = Context.getTranslationUnitDecl(); bool FallbackEnabled = IsArray && Context.getLangOpts().MSVCCompat; if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, TUDecl, /*AllowMissing=*/FallbackEnabled, OperatorNew, /*Diagnose=*/!FallbackEnabled)) { if (!FallbackEnabled) return true; // MSVC will fall back on trying to find a matching global operator new // if operator new[] cannot be found. Also, MSVC will leak by not // generating a call to operator delete or operator delete[], but we // will not replicate that bug. NewName = Context.DeclarationNames.getCXXOperatorName(OO_New); DeleteName = Context.DeclarationNames.getCXXOperatorName(OO_Delete); if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, TUDecl, /*AllowMissing=*/false, OperatorNew)) return true; } } // We don't need an operator delete if we're running under // -fno-exceptions. if (!getLangOpts().Exceptions) { OperatorDelete = nullptr; return false; } // C++ [expr.new]p19: // // If the new-expression begins with a unary :: operator, the // deallocation function's name is looked up in the global // scope. Otherwise, if the allocated type is a class type T or an // array thereof, the deallocation function's name is looked up in // the scope of T. If this lookup fails to find the name, or if // the allocated type is not a class type or array thereof, the // deallocation function's name is looked up in the global scope. LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName); if (AllocElemType->isRecordType() && !UseGlobal) { CXXRecordDecl *RD = cast(AllocElemType->getAs()->getDecl()); LookupQualifiedName(FoundDelete, RD); } if (FoundDelete.isAmbiguous()) return true; // FIXME: clean up expressions? if (FoundDelete.empty()) { DeclareGlobalNewDelete(); LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl()); } FoundDelete.suppressDiagnostics(); SmallVector, 2> Matches; // Whether we're looking for a placement operator delete is dictated // by whether we selected a placement operator new, not by whether // we had explicit placement arguments. This matters for things like // struct A { void *operator new(size_t, int = 0); ... }; // A *a = new A() bool isPlacementNew = (!PlaceArgs.empty() || OperatorNew->param_size() != 1); if (isPlacementNew) { // C++ [expr.new]p20: // A declaration of a placement deallocation function matches the // declaration of a placement allocation function if it has the // same number of parameters and, after parameter transformations // (8.3.5), all parameter types except the first are // identical. [...] // // To perform this comparison, we compute the function type that // the deallocation function should have, and use that type both // for template argument deduction and for comparison purposes. // // FIXME: this comparison should ignore CC and the like. QualType ExpectedFunctionType; { const FunctionProtoType *Proto = OperatorNew->getType()->getAs(); SmallVector ArgTypes; ArgTypes.push_back(Context.VoidPtrTy); for (unsigned I = 1, N = Proto->getNumParams(); I < N; ++I) ArgTypes.push_back(Proto->getParamType(I)); FunctionProtoType::ExtProtoInfo EPI; EPI.Variadic = Proto->isVariadic(); ExpectedFunctionType = Context.getFunctionType(Context.VoidTy, ArgTypes, EPI); } for (LookupResult::iterator D = FoundDelete.begin(), DEnd = FoundDelete.end(); D != DEnd; ++D) { FunctionDecl *Fn = nullptr; if (FunctionTemplateDecl *FnTmpl = dyn_cast((*D)->getUnderlyingDecl())) { // Perform template argument deduction to try to match the // expected function type. TemplateDeductionInfo Info(StartLoc); if (DeduceTemplateArguments(FnTmpl, nullptr, ExpectedFunctionType, Fn, Info)) continue; } else Fn = cast((*D)->getUnderlyingDecl()); if (Context.hasSameType(Fn->getType(), ExpectedFunctionType)) Matches.push_back(std::make_pair(D.getPair(), Fn)); } } else { // C++ [expr.new]p20: // [...] Any non-placement deallocation function matches a // non-placement allocation function. [...] for (LookupResult::iterator D = FoundDelete.begin(), DEnd = FoundDelete.end(); D != DEnd; ++D) { if (FunctionDecl *Fn = dyn_cast((*D)->getUnderlyingDecl())) if (isNonPlacementDeallocationFunction(*this, Fn)) Matches.push_back(std::make_pair(D.getPair(), Fn)); } // C++1y [expr.new]p22: // For a non-placement allocation function, the normal deallocation // function lookup is used // C++1y [expr.delete]p?: // If [...] deallocation function lookup finds both a usual deallocation // function with only a pointer parameter and a usual deallocation // function with both a pointer parameter and a size parameter, then the // selected deallocation function shall be the one with two parameters. // Otherwise, the selected deallocation function shall be the function // with one parameter. if (getLangOpts().SizedDeallocation && Matches.size() == 2) { if (Matches[0].second->getNumParams() == 1) Matches.erase(Matches.begin()); else Matches.erase(Matches.begin() + 1); assert(Matches[0].second->getNumParams() == 2 && "found an unexpected usual deallocation function"); } } // C++ [expr.new]p20: // [...] If the lookup finds a single matching deallocation // function, that function will be called; otherwise, no // deallocation function will be called. if (Matches.size() == 1) { OperatorDelete = Matches[0].second; // C++0x [expr.new]p20: // If the lookup finds the two-parameter form of a usual // deallocation function (3.7.4.2) and that function, considered // as a placement deallocation function, would have been // selected as a match for the allocation function, the program // is ill-formed. if (!PlaceArgs.empty() && getLangOpts().CPlusPlus11 && isNonPlacementDeallocationFunction(*this, OperatorDelete)) { Diag(StartLoc, diag::err_placement_new_non_placement_delete) << SourceRange(PlaceArgs.front()->getLocStart(), PlaceArgs.back()->getLocEnd()); if (!OperatorDelete->isImplicit()) Diag(OperatorDelete->getLocation(), diag::note_previous_decl) << DeleteName; } else { CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(), Matches[0].first); } } return false; } /// \brief Find an fitting overload for the allocation function /// in the specified scope. /// /// \param StartLoc The location of the 'new' token. /// \param Range The range of the placement arguments. /// \param Name The name of the function ('operator new' or 'operator new[]'). /// \param Args The placement arguments specified. /// \param Ctx The scope in which we should search; either a class scope or the /// translation unit. /// \param AllowMissing If \c true, report an error if we can't find any /// allocation functions. Otherwise, succeed but don't fill in \p /// Operator. /// \param Operator Filled in with the found allocation function. Unchanged if /// no allocation function was found. /// \param Diagnose If \c true, issue errors if the allocation function is not /// usable. bool Sema::FindAllocationOverload(SourceLocation StartLoc, SourceRange Range, DeclarationName Name, MultiExprArg Args, DeclContext *Ctx, bool AllowMissing, FunctionDecl *&Operator, bool Diagnose) { LookupResult R(*this, Name, StartLoc, LookupOrdinaryName); LookupQualifiedName(R, Ctx); if (R.empty()) { if (AllowMissing || !Diagnose) return false; return Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) << Name << Range; } if (R.isAmbiguous()) return true; R.suppressDiagnostics(); OverloadCandidateSet Candidates(StartLoc, OverloadCandidateSet::CSK_Normal); for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end(); Alloc != AllocEnd; ++Alloc) { // Even member operator new/delete are implicitly treated as // static, so don't use AddMemberCandidate. NamedDecl *D = (*Alloc)->getUnderlyingDecl(); if (FunctionTemplateDecl *FnTemplate = dyn_cast(D)) { AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(), /*ExplicitTemplateArgs=*/nullptr, Args, Candidates, /*SuppressUserConversions=*/false); continue; } FunctionDecl *Fn = cast(D); AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates, /*SuppressUserConversions=*/false); } // Do the resolution. OverloadCandidateSet::iterator Best; switch (Candidates.BestViableFunction(*this, StartLoc, Best)) { case OR_Success: { // Got one! FunctionDecl *FnDecl = Best->Function; if (CheckAllocationAccess(StartLoc, Range, R.getNamingClass(), Best->FoundDecl, Diagnose) == AR_inaccessible) return true; Operator = FnDecl; return false; } case OR_No_Viable_Function: if (Diagnose) { Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) << Name << Range; Candidates.NoteCandidates(*this, OCD_AllCandidates, Args); } return true; case OR_Ambiguous: if (Diagnose) { Diag(StartLoc, diag::err_ovl_ambiguous_call) << Name << Range; Candidates.NoteCandidates(*this, OCD_ViableCandidates, Args); } return true; case OR_Deleted: { if (Diagnose) { Diag(StartLoc, diag::err_ovl_deleted_call) << Best->Function->isDeleted() << Name << getDeletedOrUnavailableSuffix(Best->Function) << Range; Candidates.NoteCandidates(*this, OCD_AllCandidates, Args); } return true; } } llvm_unreachable("Unreachable, bad result from BestViableFunction"); } /// DeclareGlobalNewDelete - Declare the global forms of operator new and /// delete. These are: /// @code /// // C++03: /// void* operator new(std::size_t) throw(std::bad_alloc); /// void* operator new[](std::size_t) throw(std::bad_alloc); /// void operator delete(void *) throw(); /// void operator delete[](void *) throw(); /// // C++11: /// void* operator new(std::size_t); /// void* operator new[](std::size_t); /// void operator delete(void *) noexcept; /// void operator delete[](void *) noexcept; /// // C++1y: /// void* operator new(std::size_t); /// void* operator new[](std::size_t); /// void operator delete(void *) noexcept; /// void operator delete[](void *) noexcept; /// void operator delete(void *, std::size_t) noexcept; /// void operator delete[](void *, std::size_t) noexcept; /// @endcode /// Note that the placement and nothrow forms of new are *not* implicitly /// declared. Their use requires including \. void Sema::DeclareGlobalNewDelete() { if (GlobalNewDeleteDeclared) return; // C++ [basic.std.dynamic]p2: // [...] The following allocation and deallocation functions (18.4) are // implicitly declared in global scope in each translation unit of a // program // // C++03: // void* operator new(std::size_t) throw(std::bad_alloc); // void* operator new[](std::size_t) throw(std::bad_alloc); // void operator delete(void*) throw(); // void operator delete[](void*) throw(); // C++11: // void* operator new(std::size_t); // void* operator new[](std::size_t); // void operator delete(void*) noexcept; // void operator delete[](void*) noexcept; // C++1y: // void* operator new(std::size_t); // void* operator new[](std::size_t); // void operator delete(void*) noexcept; // void operator delete[](void*) noexcept; // void operator delete(void*, std::size_t) noexcept; // void operator delete[](void*, std::size_t) noexcept; // // These implicit declarations introduce only the function names operator // new, operator new[], operator delete, operator delete[]. // // Here, we need to refer to std::bad_alloc, so we will implicitly declare // "std" or "bad_alloc" as necessary to form the exception specification. // However, we do not make these implicit declarations visible to name // lookup. if (!StdBadAlloc && !getLangOpts().CPlusPlus11) { // The "std::bad_alloc" class has not yet been declared, so build it // implicitly. StdBadAlloc = CXXRecordDecl::Create(Context, TTK_Class, getOrCreateStdNamespace(), SourceLocation(), SourceLocation(), &PP.getIdentifierTable().get("bad_alloc"), nullptr); getStdBadAlloc()->setImplicit(true); } GlobalNewDeleteDeclared = true; QualType VoidPtr = Context.getPointerType(Context.VoidTy); QualType SizeT = Context.getSizeType(); DeclareGlobalAllocationFunction( Context.DeclarationNames.getCXXOperatorName(OO_New), VoidPtr, SizeT, QualType()); DeclareGlobalAllocationFunction( Context.DeclarationNames.getCXXOperatorName(OO_Array_New), VoidPtr, SizeT, QualType()); DeclareGlobalAllocationFunction( Context.DeclarationNames.getCXXOperatorName(OO_Delete), Context.VoidTy, VoidPtr); DeclareGlobalAllocationFunction( Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete), Context.VoidTy, VoidPtr); if (getLangOpts().SizedDeallocation) { DeclareGlobalAllocationFunction( Context.DeclarationNames.getCXXOperatorName(OO_Delete), Context.VoidTy, VoidPtr, Context.getSizeType()); DeclareGlobalAllocationFunction( Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete), Context.VoidTy, VoidPtr, Context.getSizeType()); } } /// DeclareGlobalAllocationFunction - Declares a single implicit global /// allocation function if it doesn't already exist. void Sema::DeclareGlobalAllocationFunction(DeclarationName Name, QualType Return, QualType Param1, QualType Param2) { DeclContext *GlobalCtx = Context.getTranslationUnitDecl(); unsigned NumParams = Param2.isNull() ? 1 : 2; // Check if this function is already declared. DeclContext::lookup_result R = GlobalCtx->lookup(Name); for (DeclContext::lookup_iterator Alloc = R.begin(), AllocEnd = R.end(); Alloc != AllocEnd; ++Alloc) { // Only look at non-template functions, as it is the predefined, // non-templated allocation function we are trying to declare here. if (FunctionDecl *Func = dyn_cast(*Alloc)) { if (Func->getNumParams() == NumParams) { QualType InitialParam1Type = Context.getCanonicalType(Func->getParamDecl(0) ->getType().getUnqualifiedType()); QualType InitialParam2Type = NumParams == 2 ? Context.getCanonicalType(Func->getParamDecl(1) ->getType().getUnqualifiedType()) : QualType(); // FIXME: Do we need to check for default arguments here? if (InitialParam1Type == Param1 && (NumParams == 1 || InitialParam2Type == Param2)) { // Make the function visible to name lookup, even if we found it in // an unimported module. It either is an implicitly-declared global // allocation function, or is suppressing that function. Func->setHidden(false); return; } } } } FunctionProtoType::ExtProtoInfo EPI; QualType BadAllocType; bool HasBadAllocExceptionSpec = (Name.getCXXOverloadedOperator() == OO_New || Name.getCXXOverloadedOperator() == OO_Array_New); if (HasBadAllocExceptionSpec) { if (!getLangOpts().CPlusPlus11) { BadAllocType = Context.getTypeDeclType(getStdBadAlloc()); assert(StdBadAlloc && "Must have std::bad_alloc declared"); EPI.ExceptionSpec.Type = EST_Dynamic; EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType); } } else { EPI.ExceptionSpec = getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone; } QualType Params[] = { Param1, Param2 }; QualType FnType = Context.getFunctionType( Return, llvm::makeArrayRef(Params, NumParams), EPI); FunctionDecl *Alloc = FunctionDecl::Create(Context, GlobalCtx, SourceLocation(), SourceLocation(), Name, FnType, /*TInfo=*/nullptr, SC_None, false, true); Alloc->setImplicit(); // Implicit sized deallocation functions always have default visibility. Alloc->addAttr(VisibilityAttr::CreateImplicit(Context, VisibilityAttr::Default)); ParmVarDecl *ParamDecls[2]; for (unsigned I = 0; I != NumParams; ++I) { ParamDecls[I] = ParmVarDecl::Create(Context, Alloc, SourceLocation(), SourceLocation(), nullptr, Params[I], /*TInfo=*/nullptr, SC_None, nullptr); ParamDecls[I]->setImplicit(); } Alloc->setParams(llvm::makeArrayRef(ParamDecls, NumParams)); Context.getTranslationUnitDecl()->addDecl(Alloc); IdResolver.tryAddTopLevelDecl(Alloc, Name); } FunctionDecl *Sema::FindUsualDeallocationFunction(SourceLocation StartLoc, bool CanProvideSize, DeclarationName Name) { DeclareGlobalNewDelete(); LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName); LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl()); // C++ [expr.new]p20: // [...] Any non-placement deallocation function matches a // non-placement allocation function. [...] llvm::SmallVector Matches; for (LookupResult::iterator D = FoundDelete.begin(), DEnd = FoundDelete.end(); D != DEnd; ++D) { if (FunctionDecl *Fn = dyn_cast(*D)) if (isNonPlacementDeallocationFunction(*this, Fn)) Matches.push_back(Fn); } // C++1y [expr.delete]p?: // If the type is complete and deallocation function lookup finds both a // usual deallocation function with only a pointer parameter and a usual // deallocation function with both a pointer parameter and a size // parameter, then the selected deallocation function shall be the one // with two parameters. Otherwise, the selected deallocation function // shall be the function with one parameter. if (getLangOpts().SizedDeallocation && Matches.size() == 2) { unsigned NumArgs = CanProvideSize ? 2 : 1; if (Matches[0]->getNumParams() != NumArgs) Matches.erase(Matches.begin()); else Matches.erase(Matches.begin() + 1); assert(Matches[0]->getNumParams() == NumArgs && "found an unexpected usual deallocation function"); } if (getLangOpts().CUDA) EraseUnwantedCUDAMatches(dyn_cast(CurContext), Matches); assert(Matches.size() == 1 && "unexpectedly have multiple usual deallocation functions"); return Matches.front(); } bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD, DeclarationName Name, FunctionDecl* &Operator, bool Diagnose) { LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName); // Try to find operator delete/operator delete[] in class scope. LookupQualifiedName(Found, RD); if (Found.isAmbiguous()) return true; Found.suppressDiagnostics(); SmallVector Matches; for (LookupResult::iterator F = Found.begin(), FEnd = Found.end(); F != FEnd; ++F) { NamedDecl *ND = (*F)->getUnderlyingDecl(); // Ignore template operator delete members from the check for a usual // deallocation function. if (isa(ND)) continue; if (cast(ND)->isUsualDeallocationFunction()) Matches.push_back(F.getPair()); } if (getLangOpts().CUDA) EraseUnwantedCUDAMatches(dyn_cast(CurContext), Matches); // There's exactly one suitable operator; pick it. if (Matches.size() == 1) { Operator = cast(Matches[0]->getUnderlyingDecl()); if (Operator->isDeleted()) { if (Diagnose) { Diag(StartLoc, diag::err_deleted_function_use); NoteDeletedFunction(Operator); } return true; } if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(), Matches[0], Diagnose) == AR_inaccessible) return true; return false; // We found multiple suitable operators; complain about the ambiguity. } else if (!Matches.empty()) { if (Diagnose) { Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found) << Name << RD; for (SmallVectorImpl::iterator F = Matches.begin(), FEnd = Matches.end(); F != FEnd; ++F) Diag((*F)->getUnderlyingDecl()->getLocation(), diag::note_member_declared_here) << Name; } return true; } // We did find operator delete/operator delete[] declarations, but // none of them were suitable. if (!Found.empty()) { if (Diagnose) { Diag(StartLoc, diag::err_no_suitable_delete_member_function_found) << Name << RD; for (LookupResult::iterator F = Found.begin(), FEnd = Found.end(); F != FEnd; ++F) Diag((*F)->getUnderlyingDecl()->getLocation(), diag::note_member_declared_here) << Name; } return true; } Operator = nullptr; return false; } namespace { /// \brief Checks whether delete-expression, and new-expression used for /// initializing deletee have the same array form. class MismatchingNewDeleteDetector { public: enum MismatchResult { /// Indicates that there is no mismatch or a mismatch cannot be proven. NoMismatch, /// Indicates that variable is initialized with mismatching form of \a new. VarInitMismatches, /// Indicates that member is initialized with mismatching form of \a new. MemberInitMismatches, /// Indicates that 1 or more constructors' definitions could not been /// analyzed, and they will be checked again at the end of translation unit. AnalyzeLater }; /// \param EndOfTU True, if this is the final analysis at the end of /// translation unit. False, if this is the initial analysis at the point /// delete-expression was encountered. explicit MismatchingNewDeleteDetector(bool EndOfTU) : IsArrayForm(false), Field(nullptr), EndOfTU(EndOfTU), HasUndefinedConstructors(false) {} /// \brief Checks whether pointee of a delete-expression is initialized with /// matching form of new-expression. /// /// If return value is \c VarInitMismatches or \c MemberInitMismatches at the /// point where delete-expression is encountered, then a warning will be /// issued immediately. If return value is \c AnalyzeLater at the point where /// delete-expression is seen, then member will be analyzed at the end of /// translation unit. \c AnalyzeLater is returned iff at least one constructor /// couldn't be analyzed. If at least one constructor initializes the member /// with matching type of new, the return value is \c NoMismatch. MismatchResult analyzeDeleteExpr(const CXXDeleteExpr *DE); /// \brief Analyzes a class member. /// \param Field Class member to analyze. /// \param DeleteWasArrayForm Array form-ness of the delete-expression used /// for deleting the \p Field. MismatchResult analyzeField(FieldDecl *Field, bool DeleteWasArrayForm); /// List of mismatching new-expressions used for initialization of the pointee llvm::SmallVector NewExprs; /// Indicates whether delete-expression was in array form. bool IsArrayForm; FieldDecl *Field; private: const bool EndOfTU; /// \brief Indicates that there is at least one constructor without body. bool HasUndefinedConstructors; /// \brief Returns \c CXXNewExpr from given initialization expression. /// \param E Expression used for initializing pointee in delete-expression. /// E can be a single-element \c InitListExpr consisting of new-expression. const CXXNewExpr *getNewExprFromInitListOrExpr(const Expr *E); /// \brief Returns whether member is initialized with mismatching form of /// \c new either by the member initializer or in-class initialization. /// /// If bodies of all constructors are not visible at the end of translation /// unit or at least one constructor initializes member with the matching /// form of \c new, mismatch cannot be proven, and this function will return /// \c NoMismatch. MismatchResult analyzeMemberExpr(const MemberExpr *ME); /// \brief Returns whether variable is initialized with mismatching form of /// \c new. /// /// If variable is initialized with matching form of \c new or variable is not /// initialized with a \c new expression, this function will return true. /// If variable is initialized with mismatching form of \c new, returns false. /// \param D Variable to analyze. bool hasMatchingVarInit(const DeclRefExpr *D); /// \brief Checks whether the constructor initializes pointee with mismatching /// form of \c new. /// /// Returns true, if member is initialized with matching form of \c new in /// member initializer list. Returns false, if member is initialized with the /// matching form of \c new in this constructor's initializer or given /// constructor isn't defined at the point where delete-expression is seen, or /// member isn't initialized by the constructor. bool hasMatchingNewInCtor(const CXXConstructorDecl *CD); /// \brief Checks whether member is initialized with matching form of /// \c new in member initializer list. bool hasMatchingNewInCtorInit(const CXXCtorInitializer *CI); /// Checks whether member is initialized with mismatching form of \c new by /// in-class initializer. MismatchResult analyzeInClassInitializer(); }; } MismatchingNewDeleteDetector::MismatchResult MismatchingNewDeleteDetector::analyzeDeleteExpr(const CXXDeleteExpr *DE) { NewExprs.clear(); assert(DE && "Expected delete-expression"); IsArrayForm = DE->isArrayForm(); const Expr *E = DE->getArgument()->IgnoreParenImpCasts(); if (const MemberExpr *ME = dyn_cast(E)) { return analyzeMemberExpr(ME); } else if (const DeclRefExpr *D = dyn_cast(E)) { if (!hasMatchingVarInit(D)) return VarInitMismatches; } return NoMismatch; } const CXXNewExpr * MismatchingNewDeleteDetector::getNewExprFromInitListOrExpr(const Expr *E) { assert(E != nullptr && "Expected a valid initializer expression"); E = E->IgnoreParenImpCasts(); if (const InitListExpr *ILE = dyn_cast(E)) { if (ILE->getNumInits() == 1) E = dyn_cast(ILE->getInit(0)->IgnoreParenImpCasts()); } return dyn_cast_or_null(E); } bool MismatchingNewDeleteDetector::hasMatchingNewInCtorInit( const CXXCtorInitializer *CI) { const CXXNewExpr *NE = nullptr; if (Field == CI->getMember() && (NE = getNewExprFromInitListOrExpr(CI->getInit()))) { if (NE->isArray() == IsArrayForm) return true; else NewExprs.push_back(NE); } return false; } bool MismatchingNewDeleteDetector::hasMatchingNewInCtor( const CXXConstructorDecl *CD) { if (CD->isImplicit()) return false; const FunctionDecl *Definition = CD; if (!CD->isThisDeclarationADefinition() && !CD->isDefined(Definition)) { HasUndefinedConstructors = true; return EndOfTU; } for (const auto *CI : cast(Definition)->inits()) { if (hasMatchingNewInCtorInit(CI)) return true; } return false; } MismatchingNewDeleteDetector::MismatchResult MismatchingNewDeleteDetector::analyzeInClassInitializer() { assert(Field != nullptr && "This should be called only for members"); const Expr *InitExpr = Field->getInClassInitializer(); if (!InitExpr) return EndOfTU ? NoMismatch : AnalyzeLater; if (const CXXNewExpr *NE = getNewExprFromInitListOrExpr(InitExpr)) { if (NE->isArray() != IsArrayForm) { NewExprs.push_back(NE); return MemberInitMismatches; } } return NoMismatch; } MismatchingNewDeleteDetector::MismatchResult MismatchingNewDeleteDetector::analyzeField(FieldDecl *Field, bool DeleteWasArrayForm) { assert(Field != nullptr && "Analysis requires a valid class member."); this->Field = Field; IsArrayForm = DeleteWasArrayForm; const CXXRecordDecl *RD = cast(Field->getParent()); for (const auto *CD : RD->ctors()) { if (hasMatchingNewInCtor(CD)) return NoMismatch; } if (HasUndefinedConstructors) return EndOfTU ? NoMismatch : AnalyzeLater; if (!NewExprs.empty()) return MemberInitMismatches; return Field->hasInClassInitializer() ? analyzeInClassInitializer() : NoMismatch; } MismatchingNewDeleteDetector::MismatchResult MismatchingNewDeleteDetector::analyzeMemberExpr(const MemberExpr *ME) { assert(ME != nullptr && "Expected a member expression"); if (FieldDecl *F = dyn_cast(ME->getMemberDecl())) return analyzeField(F, IsArrayForm); return NoMismatch; } bool MismatchingNewDeleteDetector::hasMatchingVarInit(const DeclRefExpr *D) { const CXXNewExpr *NE = nullptr; if (const VarDecl *VD = dyn_cast(D->getDecl())) { if (VD->hasInit() && (NE = getNewExprFromInitListOrExpr(VD->getInit())) && NE->isArray() != IsArrayForm) { NewExprs.push_back(NE); } } return NewExprs.empty(); } static void DiagnoseMismatchedNewDelete(Sema &SemaRef, SourceLocation DeleteLoc, const MismatchingNewDeleteDetector &Detector) { SourceLocation EndOfDelete = SemaRef.getLocForEndOfToken(DeleteLoc); FixItHint H; if (!Detector.IsArrayForm) H = FixItHint::CreateInsertion(EndOfDelete, "[]"); else { SourceLocation RSquare = Lexer::findLocationAfterToken( DeleteLoc, tok::l_square, SemaRef.getSourceManager(), SemaRef.getLangOpts(), true); if (RSquare.isValid()) H = FixItHint::CreateRemoval(SourceRange(EndOfDelete, RSquare)); } SemaRef.Diag(DeleteLoc, diag::warn_mismatched_delete_new) << Detector.IsArrayForm << H; for (const auto *NE : Detector.NewExprs) SemaRef.Diag(NE->getExprLoc(), diag::note_allocated_here) << Detector.IsArrayForm; } void Sema::AnalyzeDeleteExprMismatch(const CXXDeleteExpr *DE) { if (Diags.isIgnored(diag::warn_mismatched_delete_new, SourceLocation())) return; MismatchingNewDeleteDetector Detector(/*EndOfTU=*/false); switch (Detector.analyzeDeleteExpr(DE)) { case MismatchingNewDeleteDetector::VarInitMismatches: case MismatchingNewDeleteDetector::MemberInitMismatches: { DiagnoseMismatchedNewDelete(*this, DE->getLocStart(), Detector); break; } case MismatchingNewDeleteDetector::AnalyzeLater: { DeleteExprs[Detector.Field].push_back( std::make_pair(DE->getLocStart(), DE->isArrayForm())); break; } case MismatchingNewDeleteDetector::NoMismatch: break; } } void Sema::AnalyzeDeleteExprMismatch(FieldDecl *Field, SourceLocation DeleteLoc, bool DeleteWasArrayForm) { MismatchingNewDeleteDetector Detector(/*EndOfTU=*/true); switch (Detector.analyzeField(Field, DeleteWasArrayForm)) { case MismatchingNewDeleteDetector::VarInitMismatches: llvm_unreachable("This analysis should have been done for class members."); case MismatchingNewDeleteDetector::AnalyzeLater: llvm_unreachable("Analysis cannot be postponed any point beyond end of " "translation unit."); case MismatchingNewDeleteDetector::MemberInitMismatches: DiagnoseMismatchedNewDelete(*this, DeleteLoc, Detector); break; case MismatchingNewDeleteDetector::NoMismatch: break; } } /// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in: /// @code ::delete ptr; @endcode /// or /// @code delete [] ptr; @endcode ExprResult Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal, bool ArrayForm, Expr *ExE) { // C++ [expr.delete]p1: // The operand shall have a pointer type, or a class type having a single // non-explicit conversion function to a pointer type. The result has type // void. // // DR599 amends "pointer type" to "pointer to object type" in both cases. ExprResult Ex = ExE; FunctionDecl *OperatorDelete = nullptr; bool ArrayFormAsWritten = ArrayForm; bool UsualArrayDeleteWantsSize = false; if (!Ex.get()->isTypeDependent()) { // Perform lvalue-to-rvalue cast, if needed. Ex = DefaultLvalueConversion(Ex.get()); if (Ex.isInvalid()) return ExprError(); QualType Type = Ex.get()->getType(); class DeleteConverter : public ContextualImplicitConverter { public: DeleteConverter() : ContextualImplicitConverter(false, true) {} bool match(QualType ConvType) override { // FIXME: If we have an operator T* and an operator void*, we must pick // the operator T*. if (const PointerType *ConvPtrType = ConvType->getAs()) if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType()) return true; return false; } SemaDiagnosticBuilder diagnoseNoMatch(Sema &S, SourceLocation Loc, QualType T) override { return S.Diag(Loc, diag::err_delete_operand) << T; } SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc, QualType T) override { return S.Diag(Loc, diag::err_delete_incomplete_class_type) << T; } SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { return S.Diag(Loc, diag::err_delete_explicit_conversion) << T << ConvTy; } SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { return S.Diag(Conv->getLocation(), diag::note_delete_conversion) << ConvTy; } SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc, QualType T) override { return S.Diag(Loc, diag::err_ambiguous_delete_operand) << T; } SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { return S.Diag(Conv->getLocation(), diag::note_delete_conversion) << ConvTy; } SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { llvm_unreachable("conversion functions are permitted"); } } Converter; Ex = PerformContextualImplicitConversion(StartLoc, Ex.get(), Converter); if (Ex.isInvalid()) return ExprError(); Type = Ex.get()->getType(); if (!Converter.match(Type)) // FIXME: PerformContextualImplicitConversion should return ExprError // itself in this case. return ExprError(); QualType Pointee = Type->getAs()->getPointeeType(); QualType PointeeElem = Context.getBaseElementType(Pointee); if (unsigned AddressSpace = Pointee.getAddressSpace()) return Diag(Ex.get()->getLocStart(), diag::err_address_space_qualified_delete) << Pointee.getUnqualifiedType() << AddressSpace; CXXRecordDecl *PointeeRD = nullptr; if (Pointee->isVoidType() && !isSFINAEContext()) { // The C++ standard bans deleting a pointer to a non-object type, which // effectively bans deletion of "void*". However, most compilers support // this, so we treat it as a warning unless we're in a SFINAE context. Diag(StartLoc, diag::ext_delete_void_ptr_operand) << Type << Ex.get()->getSourceRange(); } else if (Pointee->isFunctionType() || Pointee->isVoidType()) { return ExprError(Diag(StartLoc, diag::err_delete_operand) << Type << Ex.get()->getSourceRange()); } else if (!Pointee->isDependentType()) { // FIXME: This can result in errors if the definition was imported from a // module but is hidden. if (!RequireCompleteType(StartLoc, Pointee, diag::warn_delete_incomplete, Ex.get())) { if (const RecordType *RT = PointeeElem->getAs()) PointeeRD = cast(RT->getDecl()); } } if (Pointee->isArrayType() && !ArrayForm) { Diag(StartLoc, diag::warn_delete_array_type) << Type << Ex.get()->getSourceRange() << FixItHint::CreateInsertion(getLocForEndOfToken(StartLoc), "[]"); ArrayForm = true; } DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( ArrayForm ? OO_Array_Delete : OO_Delete); if (PointeeRD) { if (!UseGlobal && FindDeallocationFunction(StartLoc, PointeeRD, DeleteName, OperatorDelete)) return ExprError(); // If we're allocating an array of records, check whether the // usual operator delete[] has a size_t parameter. if (ArrayForm) { // If the user specifically asked to use the global allocator, // we'll need to do the lookup into the class. if (UseGlobal) UsualArrayDeleteWantsSize = doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem); // Otherwise, the usual operator delete[] should be the // function we just found. else if (OperatorDelete && isa(OperatorDelete)) UsualArrayDeleteWantsSize = (OperatorDelete->getNumParams() == 2); } if (!PointeeRD->hasIrrelevantDestructor()) if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { MarkFunctionReferenced(StartLoc, const_cast(Dtor)); if (DiagnoseUseOfDecl(Dtor, StartLoc)) return ExprError(); } CheckVirtualDtorCall(PointeeRD->getDestructor(), StartLoc, /*IsDelete=*/true, /*CallCanBeVirtual=*/true, /*WarnOnNonAbstractTypes=*/!ArrayForm, SourceLocation()); } if (!OperatorDelete) // Look for a global declaration. OperatorDelete = FindUsualDeallocationFunction( StartLoc, isCompleteType(StartLoc, Pointee) && (!ArrayForm || UsualArrayDeleteWantsSize || Pointee.isDestructedType()), DeleteName); MarkFunctionReferenced(StartLoc, OperatorDelete); // Check access and ambiguity of operator delete and destructor. if (PointeeRD) { if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor, PDiag(diag::err_access_dtor) << PointeeElem); } } } CXXDeleteExpr *Result = new (Context) CXXDeleteExpr( Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten, UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc); AnalyzeDeleteExprMismatch(Result); return Result; } void Sema::CheckVirtualDtorCall(CXXDestructorDecl *dtor, SourceLocation Loc, bool IsDelete, bool CallCanBeVirtual, bool WarnOnNonAbstractTypes, SourceLocation DtorLoc) { if (!dtor || dtor->isVirtual() || !CallCanBeVirtual) return; // C++ [expr.delete]p3: // In the first alternative (delete object), if the static type of the // object to be deleted is different from its dynamic type, the static // type shall be a base class of the dynamic type of the object to be // deleted and the static type shall have a virtual destructor or the // behavior is undefined. // const CXXRecordDecl *PointeeRD = dtor->getParent(); // Note: a final class cannot be derived from, no issue there if (!PointeeRD->isPolymorphic() || PointeeRD->hasAttr()) return; QualType ClassType = dtor->getThisType(Context)->getPointeeType(); if (PointeeRD->isAbstract()) { // If the class is abstract, we warn by default, because we're // sure the code has undefined behavior. Diag(Loc, diag::warn_delete_abstract_non_virtual_dtor) << (IsDelete ? 0 : 1) << ClassType; } else if (WarnOnNonAbstractTypes) { // Otherwise, if this is not an array delete, it's a bit suspect, // but not necessarily wrong. Diag(Loc, diag::warn_delete_non_virtual_dtor) << (IsDelete ? 0 : 1) << ClassType; } if (!IsDelete) { std::string TypeStr; ClassType.getAsStringInternal(TypeStr, getPrintingPolicy()); Diag(DtorLoc, diag::note_delete_non_virtual) << FixItHint::CreateInsertion(DtorLoc, TypeStr + "::"); } } Sema::ConditionResult Sema::ActOnConditionVariable(Decl *ConditionVar, SourceLocation StmtLoc, ConditionKind CK) { ExprResult E = CheckConditionVariable(cast(ConditionVar), StmtLoc, CK); if (E.isInvalid()) return ConditionError(); return ConditionResult(*this, ConditionVar, MakeFullExpr(E.get(), StmtLoc), CK == ConditionKind::ConstexprIf); } /// \brief Check the use of the given variable as a C++ condition in an if, /// while, do-while, or switch statement. ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar, SourceLocation StmtLoc, ConditionKind CK) { if (ConditionVar->isInvalidDecl()) return ExprError(); QualType T = ConditionVar->getType(); // C++ [stmt.select]p2: // The declarator shall not specify a function or an array. if (T->isFunctionType()) return ExprError(Diag(ConditionVar->getLocation(), diag::err_invalid_use_of_function_type) << ConditionVar->getSourceRange()); else if (T->isArrayType()) return ExprError(Diag(ConditionVar->getLocation(), diag::err_invalid_use_of_array_type) << ConditionVar->getSourceRange()); ExprResult Condition = DeclRefExpr::Create( Context, NestedNameSpecifierLoc(), SourceLocation(), ConditionVar, /*enclosing*/ false, ConditionVar->getLocation(), ConditionVar->getType().getNonReferenceType(), VK_LValue); MarkDeclRefReferenced(cast(Condition.get())); switch (CK) { case ConditionKind::Boolean: return CheckBooleanCondition(StmtLoc, Condition.get()); case ConditionKind::ConstexprIf: return CheckBooleanCondition(StmtLoc, Condition.get(), true); case ConditionKind::Switch: return CheckSwitchCondition(StmtLoc, Condition.get()); } llvm_unreachable("unexpected condition kind"); } /// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid. ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr, bool IsConstexpr) { // C++ 6.4p4: // The value of a condition that is an initialized declaration in a statement // other than a switch statement is the value of the declared variable // implicitly converted to type bool. If that conversion is ill-formed, the // program is ill-formed. // The value of a condition that is an expression is the value of the // expression, implicitly converted to bool. // // FIXME: Return this value to the caller so they don't need to recompute it. llvm::APSInt Value(/*BitWidth*/1); return (IsConstexpr && !CondExpr->isValueDependent()) ? CheckConvertedConstantExpression(CondExpr, Context.BoolTy, Value, CCEK_ConstexprIf) : PerformContextuallyConvertToBool(CondExpr); } /// Helper function to determine whether this is the (deprecated) C++ /// conversion from a string literal to a pointer to non-const char or /// non-const wchar_t (for narrow and wide string literals, /// respectively). bool Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) { // Look inside the implicit cast, if it exists. if (ImplicitCastExpr *Cast = dyn_cast(From)) From = Cast->getSubExpr(); // A string literal (2.13.4) that is not a wide string literal can // be converted to an rvalue of type "pointer to char"; a wide // string literal can be converted to an rvalue of type "pointer // to wchar_t" (C++ 4.2p2). if (StringLiteral *StrLit = dyn_cast(From->IgnoreParens())) if (const PointerType *ToPtrType = ToType->getAs()) if (const BuiltinType *ToPointeeType = ToPtrType->getPointeeType()->getAs()) { // This conversion is considered only when there is an // explicit appropriate pointer target type (C++ 4.2p2). if (!ToPtrType->getPointeeType().hasQualifiers()) { switch (StrLit->getKind()) { case StringLiteral::UTF8: case StringLiteral::UTF16: case StringLiteral::UTF32: // We don't allow UTF literals to be implicitly converted break; case StringLiteral::Ascii: return (ToPointeeType->getKind() == BuiltinType::Char_U || ToPointeeType->getKind() == BuiltinType::Char_S); case StringLiteral::Wide: return Context.typesAreCompatible(Context.getWideCharType(), QualType(ToPointeeType, 0)); } } } return false; } static ExprResult BuildCXXCastArgument(Sema &S, SourceLocation CastLoc, QualType Ty, CastKind Kind, CXXMethodDecl *Method, DeclAccessPair FoundDecl, bool HadMultipleCandidates, Expr *From) { switch (Kind) { default: llvm_unreachable("Unhandled cast kind!"); case CK_ConstructorConversion: { CXXConstructorDecl *Constructor = cast(Method); SmallVector ConstructorArgs; if (S.RequireNonAbstractType(CastLoc, Ty, diag::err_allocation_of_abstract_type)) return ExprError(); if (S.CompleteConstructorCall(Constructor, From, CastLoc, ConstructorArgs)) return ExprError(); S.CheckConstructorAccess(CastLoc, Constructor, FoundDecl, InitializedEntity::InitializeTemporary(Ty)); if (S.DiagnoseUseOfDecl(Method, CastLoc)) return ExprError(); ExprResult Result = S.BuildCXXConstructExpr( CastLoc, Ty, FoundDecl, cast(Method), ConstructorArgs, HadMultipleCandidates, /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, CXXConstructExpr::CK_Complete, SourceRange()); if (Result.isInvalid()) return ExprError(); return S.MaybeBindToTemporary(Result.getAs()); } case CK_UserDefinedConversion: { assert(!From->getType()->isPointerType() && "Arg can't have pointer type!"); S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ nullptr, FoundDecl); if (S.DiagnoseUseOfDecl(Method, CastLoc)) return ExprError(); // Create an implicit call expr that calls it. CXXConversionDecl *Conv = cast(Method); ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Conv, HadMultipleCandidates); if (Result.isInvalid()) return ExprError(); // Record usage of conversion in an implicit cast. Result = ImplicitCastExpr::Create(S.Context, Result.get()->getType(), CK_UserDefinedConversion, Result.get(), nullptr, Result.get()->getValueKind()); return S.MaybeBindToTemporary(Result.get()); } } } /// PerformImplicitConversion - Perform an implicit conversion of the /// expression From to the type ToType using the pre-computed implicit /// conversion sequence ICS. Returns the converted /// expression. Action is the kind of conversion we're performing, /// used in the error message. ExprResult Sema::PerformImplicitConversion(Expr *From, QualType ToType, const ImplicitConversionSequence &ICS, AssignmentAction Action, CheckedConversionKind CCK) { switch (ICS.getKind()) { case ImplicitConversionSequence::StandardConversion: { ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard, Action, CCK); if (Res.isInvalid()) return ExprError(); From = Res.get(); break; } case ImplicitConversionSequence::UserDefinedConversion: { FunctionDecl *FD = ICS.UserDefined.ConversionFunction; CastKind CastKind; QualType BeforeToType; assert(FD && "no conversion function for user-defined conversion seq"); if (const CXXConversionDecl *Conv = dyn_cast(FD)) { CastKind = CK_UserDefinedConversion; // If the user-defined conversion is specified by a conversion function, // the initial standard conversion sequence converts the source type to // the implicit object parameter of the conversion function. BeforeToType = Context.getTagDeclType(Conv->getParent()); } else { const CXXConstructorDecl *Ctor = cast(FD); CastKind = CK_ConstructorConversion; // Do no conversion if dealing with ... for the first conversion. if (!ICS.UserDefined.EllipsisConversion) { // If the user-defined conversion is specified by a constructor, the // initial standard conversion sequence converts the source type to // the type required by the argument of the constructor BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType(); } } // Watch out for ellipsis conversion. if (!ICS.UserDefined.EllipsisConversion) { ExprResult Res = PerformImplicitConversion(From, BeforeToType, ICS.UserDefined.Before, AA_Converting, CCK); if (Res.isInvalid()) return ExprError(); From = Res.get(); } ExprResult CastArg = BuildCXXCastArgument(*this, From->getLocStart(), ToType.getNonReferenceType(), CastKind, cast(FD), ICS.UserDefined.FoundConversionFunction, ICS.UserDefined.HadMultipleCandidates, From); if (CastArg.isInvalid()) return ExprError(); From = CastArg.get(); return PerformImplicitConversion(From, ToType, ICS.UserDefined.After, AA_Converting, CCK); } case ImplicitConversionSequence::AmbiguousConversion: ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(), PDiag(diag::err_typecheck_ambiguous_condition) << From->getSourceRange()); return ExprError(); case ImplicitConversionSequence::EllipsisConversion: llvm_unreachable("Cannot perform an ellipsis conversion"); case ImplicitConversionSequence::BadConversion: return ExprError(); } // Everything went well. return From; } /// PerformImplicitConversion - Perform an implicit conversion of the /// expression From to the type ToType by following the standard /// conversion sequence SCS. Returns the converted /// expression. Flavor is the context in which we're performing this /// conversion, for use in error messages. ExprResult Sema::PerformImplicitConversion(Expr *From, QualType ToType, const StandardConversionSequence& SCS, AssignmentAction Action, CheckedConversionKind CCK) { bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast); // Overall FIXME: we are recomputing too many types here and doing far too // much extra work. What this means is that we need to keep track of more // information that is computed when we try the implicit conversion initially, // so that we don't need to recompute anything here. QualType FromType = From->getType(); if (SCS.CopyConstructor) { // FIXME: When can ToType be a reference type? assert(!ToType->isReferenceType()); if (SCS.Second == ICK_Derived_To_Base) { SmallVector ConstructorArgs; if (CompleteConstructorCall(cast(SCS.CopyConstructor), From, /*FIXME:ConstructLoc*/SourceLocation(), ConstructorArgs)) return ExprError(); return BuildCXXConstructExpr( /*FIXME:ConstructLoc*/ SourceLocation(), ToType, SCS.FoundCopyConstructor, SCS.CopyConstructor, ConstructorArgs, /*HadMultipleCandidates*/ false, /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, CXXConstructExpr::CK_Complete, SourceRange()); } return BuildCXXConstructExpr( /*FIXME:ConstructLoc*/ SourceLocation(), ToType, SCS.FoundCopyConstructor, SCS.CopyConstructor, From, /*HadMultipleCandidates*/ false, /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, CXXConstructExpr::CK_Complete, SourceRange()); } // Resolve overloaded function references. if (Context.hasSameType(FromType, Context.OverloadTy)) { DeclAccessPair Found; FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType, true, Found); if (!Fn) return ExprError(); if (DiagnoseUseOfDecl(Fn, From->getLocStart())) return ExprError(); From = FixOverloadedFunctionReference(From, Found, Fn); FromType = From->getType(); } // If we're converting to an atomic type, first convert to the corresponding // non-atomic type. QualType ToAtomicType; if (const AtomicType *ToAtomic = ToType->getAs()) { ToAtomicType = ToType; ToType = ToAtomic->getValueType(); } QualType InitialFromType = FromType; // Perform the first implicit conversion. switch (SCS.First) { case ICK_Identity: if (const AtomicType *FromAtomic = FromType->getAs()) { FromType = FromAtomic->getValueType().getUnqualifiedType(); From = ImplicitCastExpr::Create(Context, FromType, CK_AtomicToNonAtomic, From, /*BasePath=*/nullptr, VK_RValue); } break; case ICK_Lvalue_To_Rvalue: { assert(From->getObjectKind() != OK_ObjCProperty); ExprResult FromRes = DefaultLvalueConversion(From); assert(!FromRes.isInvalid() && "Can't perform deduced conversion?!"); From = FromRes.get(); FromType = From->getType(); break; } case ICK_Array_To_Pointer: FromType = Context.getArrayDecayedType(FromType); From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay, VK_RValue, /*BasePath=*/nullptr, CCK).get(); break; case ICK_Function_To_Pointer: FromType = Context.getPointerType(FromType); From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay, VK_RValue, /*BasePath=*/nullptr, CCK).get(); break; default: llvm_unreachable("Improper first standard conversion"); } // Perform the second implicit conversion switch (SCS.Second) { case ICK_Identity: // C++ [except.spec]p5: // [For] assignment to and initialization of pointers to functions, // pointers to member functions, and references to functions: the // target entity shall allow at least the exceptions allowed by the // source value in the assignment or initialization. switch (Action) { case AA_Assigning: case AA_Initializing: // Note, function argument passing and returning are initialization. case AA_Passing: case AA_Returning: case AA_Sending: case AA_Passing_CFAudited: if (CheckExceptionSpecCompatibility(From, ToType)) return ExprError(); break; case AA_Casting: case AA_Converting: // Casts and implicit conversions are not initialization, so are not // checked for exception specification mismatches. break; } // Nothing else to do. break; case ICK_NoReturn_Adjustment: // If both sides are functions (or pointers/references to them), there could // be incompatible exception declarations. if (CheckExceptionSpecCompatibility(From, ToType)) return ExprError(); From = ImpCastExprToType(From, ToType, CK_NoOp, VK_RValue, /*BasePath=*/nullptr, CCK).get(); break; case ICK_Integral_Promotion: case ICK_Integral_Conversion: if (ToType->isBooleanType()) { assert(FromType->castAs()->getDecl()->isFixed() && SCS.Second == ICK_Integral_Promotion && "only enums with fixed underlying type can promote to bool"); From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean, VK_RValue, /*BasePath=*/nullptr, CCK).get(); } else { From = ImpCastExprToType(From, ToType, CK_IntegralCast, VK_RValue, /*BasePath=*/nullptr, CCK).get(); } break; case ICK_Floating_Promotion: case ICK_Floating_Conversion: From = ImpCastExprToType(From, ToType, CK_FloatingCast, VK_RValue, /*BasePath=*/nullptr, CCK).get(); break; case ICK_Complex_Promotion: case ICK_Complex_Conversion: { QualType FromEl = From->getType()->getAs()->getElementType(); QualType ToEl = ToType->getAs()->getElementType(); CastKind CK; if (FromEl->isRealFloatingType()) { if (ToEl->isRealFloatingType()) CK = CK_FloatingComplexCast; else CK = CK_FloatingComplexToIntegralComplex; } else if (ToEl->isRealFloatingType()) { CK = CK_IntegralComplexToFloatingComplex; } else { CK = CK_IntegralComplexCast; } From = ImpCastExprToType(From, ToType, CK, VK_RValue, /*BasePath=*/nullptr, CCK).get(); break; } case ICK_Floating_Integral: if (ToType->isRealFloatingType()) From = ImpCastExprToType(From, ToType, CK_IntegralToFloating, VK_RValue, /*BasePath=*/nullptr, CCK).get(); else From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral, VK_RValue, /*BasePath=*/nullptr, CCK).get(); break; case ICK_Compatible_Conversion: From = ImpCastExprToType(From, ToType, CK_NoOp, VK_RValue, /*BasePath=*/nullptr, CCK).get(); break; case ICK_Writeback_Conversion: case ICK_Pointer_Conversion: { if (SCS.IncompatibleObjC && Action != AA_Casting) { // Diagnose incompatible Objective-C conversions if (Action == AA_Initializing || Action == AA_Assigning) Diag(From->getLocStart(), diag::ext_typecheck_convert_incompatible_pointer) << ToType << From->getType() << Action << From->getSourceRange() << 0; else Diag(From->getLocStart(), diag::ext_typecheck_convert_incompatible_pointer) << From->getType() << ToType << Action << From->getSourceRange() << 0; if (From->getType()->isObjCObjectPointerType() && ToType->isObjCObjectPointerType()) EmitRelatedResultTypeNote(From); } else if (getLangOpts().ObjCAutoRefCount && !CheckObjCARCUnavailableWeakConversion(ToType, From->getType())) { if (Action == AA_Initializing) Diag(From->getLocStart(), diag::err_arc_weak_unavailable_assign); else Diag(From->getLocStart(), diag::err_arc_convesion_of_weak_unavailable) << (Action == AA_Casting) << From->getType() << ToType << From->getSourceRange(); } CastKind Kind = CK_Invalid; CXXCastPath BasePath; if (CheckPointerConversion(From, ToType, Kind, BasePath, CStyle)) return ExprError(); // Make sure we extend blocks if necessary. // FIXME: doing this here is really ugly. if (Kind == CK_BlockPointerToObjCPointerCast) { ExprResult E = From; (void) PrepareCastToObjCObjectPointer(E); From = E.get(); } if (getLangOpts().ObjCAutoRefCount) CheckObjCARCConversion(SourceRange(), ToType, From, CCK); From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK) .get(); break; } case ICK_Pointer_Member: { CastKind Kind = CK_Invalid; CXXCastPath BasePath; if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle)) return ExprError(); if (CheckExceptionSpecCompatibility(From, ToType)) return ExprError(); // We may not have been able to figure out what this member pointer resolved // to up until this exact point. Attempt to lock-in it's inheritance model. if (Context.getTargetInfo().getCXXABI().isMicrosoft()) { (void)isCompleteType(From->getExprLoc(), From->getType()); (void)isCompleteType(From->getExprLoc(), ToType); } From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK) .get(); break; } case ICK_Boolean_Conversion: // Perform half-to-boolean conversion via float. if (From->getType()->isHalfType()) { From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).get(); FromType = Context.FloatTy; } From = ImpCastExprToType(From, Context.BoolTy, ScalarTypeToBooleanCastKind(FromType), VK_RValue, /*BasePath=*/nullptr, CCK).get(); break; case ICK_Derived_To_Base: { CXXCastPath BasePath; if (CheckDerivedToBaseConversion(From->getType(), ToType.getNonReferenceType(), From->getLocStart(), From->getSourceRange(), &BasePath, CStyle)) return ExprError(); From = ImpCastExprToType(From, ToType.getNonReferenceType(), CK_DerivedToBase, From->getValueKind(), &BasePath, CCK).get(); break; } case ICK_Vector_Conversion: From = ImpCastExprToType(From, ToType, CK_BitCast, VK_RValue, /*BasePath=*/nullptr, CCK).get(); break; case ICK_Vector_Splat: { // Vector splat from any arithmetic type to a vector. Expr *Elem = prepareVectorSplat(ToType, From).get(); From = ImpCastExprToType(Elem, ToType, CK_VectorSplat, VK_RValue, /*BasePath=*/nullptr, CCK).get(); break; } case ICK_Complex_Real: // Case 1. x -> _Complex y if (const ComplexType *ToComplex = ToType->getAs()) { QualType ElType = ToComplex->getElementType(); bool isFloatingComplex = ElType->isRealFloatingType(); // x -> y if (Context.hasSameUnqualifiedType(ElType, From->getType())) { // do nothing } else if (From->getType()->isRealFloatingType()) { From = ImpCastExprToType(From, ElType, isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).get(); } else { assert(From->getType()->isIntegerType()); From = ImpCastExprToType(From, ElType, isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).get(); } // y -> _Complex y From = ImpCastExprToType(From, ToType, isFloatingComplex ? CK_FloatingRealToComplex : CK_IntegralRealToComplex).get(); // Case 2. _Complex x -> y } else { const ComplexType *FromComplex = From->getType()->getAs(); assert(FromComplex); QualType ElType = FromComplex->getElementType(); bool isFloatingComplex = ElType->isRealFloatingType(); // _Complex x -> x From = ImpCastExprToType(From, ElType, isFloatingComplex ? CK_FloatingComplexToReal : CK_IntegralComplexToReal, VK_RValue, /*BasePath=*/nullptr, CCK).get(); // x -> y if (Context.hasSameUnqualifiedType(ElType, ToType)) { // do nothing } else if (ToType->isRealFloatingType()) { From = ImpCastExprToType(From, ToType, isFloatingComplex ? CK_FloatingCast : CK_IntegralToFloating, VK_RValue, /*BasePath=*/nullptr, CCK).get(); } else { assert(ToType->isIntegerType()); From = ImpCastExprToType(From, ToType, isFloatingComplex ? CK_FloatingToIntegral : CK_IntegralCast, VK_RValue, /*BasePath=*/nullptr, CCK).get(); } } break; case ICK_Block_Pointer_Conversion: { From = ImpCastExprToType(From, ToType.getUnqualifiedType(), CK_BitCast, VK_RValue, /*BasePath=*/nullptr, CCK).get(); break; } case ICK_TransparentUnionConversion: { ExprResult FromRes = From; Sema::AssignConvertType ConvTy = CheckTransparentUnionArgumentConstraints(ToType, FromRes); if (FromRes.isInvalid()) return ExprError(); From = FromRes.get(); assert ((ConvTy == Sema::Compatible) && "Improper transparent union conversion"); (void)ConvTy; break; } case ICK_Zero_Event_Conversion: From = ImpCastExprToType(From, ToType, CK_ZeroToOCLEvent, From->getValueKind()).get(); break; case ICK_Lvalue_To_Rvalue: case ICK_Array_To_Pointer: case ICK_Function_To_Pointer: case ICK_Qualification: case ICK_Num_Conversion_Kinds: case ICK_C_Only_Conversion: llvm_unreachable("Improper second standard conversion"); } switch (SCS.Third) { case ICK_Identity: // Nothing to do. break; case ICK_Qualification: { // The qualification keeps the category of the inner expression, unless the // target type isn't a reference. ExprValueKind VK = ToType->isReferenceType() ? From->getValueKind() : VK_RValue; From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context), CK_NoOp, VK, /*BasePath=*/nullptr, CCK).get(); if (SCS.DeprecatedStringLiteralToCharPtr && !getLangOpts().WritableStrings) { Diag(From->getLocStart(), getLangOpts().CPlusPlus11 ? diag::ext_deprecated_string_literal_conversion : diag::warn_deprecated_string_literal_conversion) << ToType.getNonReferenceType(); } break; } default: llvm_unreachable("Improper third standard conversion"); } // If this conversion sequence involved a scalar -> atomic conversion, perform // that conversion now. if (!ToAtomicType.isNull()) { assert(Context.hasSameType( ToAtomicType->castAs()->getValueType(), From->getType())); From = ImpCastExprToType(From, ToAtomicType, CK_NonAtomicToAtomic, VK_RValue, nullptr, CCK).get(); } // If this conversion sequence succeeded and involved implicitly converting a // _Nullable type to a _Nonnull one, complain. if (CCK == CCK_ImplicitConversion) diagnoseNullableToNonnullConversion(ToType, InitialFromType, From->getLocStart()); return From; } /// \brief Check the completeness of a type in a unary type trait. /// /// If the particular type trait requires a complete type, tries to complete /// it. If completing the type fails, a diagnostic is emitted and false /// returned. If completing the type succeeds or no completion was required, /// returns true. static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, TypeTrait UTT, SourceLocation Loc, QualType ArgTy) { // C++0x [meta.unary.prop]p3: // For all of the class templates X declared in this Clause, instantiating // that template with a template argument that is a class template // specialization may result in the implicit instantiation of the template // argument if and only if the semantics of X require that the argument // must be a complete type. // We apply this rule to all the type trait expressions used to implement // these class templates. We also try to follow any GCC documented behavior // in these expressions to ensure portability of standard libraries. switch (UTT) { default: llvm_unreachable("not a UTT"); // is_complete_type somewhat obviously cannot require a complete type. case UTT_IsCompleteType: // Fall-through // These traits are modeled on the type predicates in C++0x // [meta.unary.cat] and [meta.unary.comp]. They are not specified as // requiring a complete type, as whether or not they return true cannot be // impacted by the completeness of the type. case UTT_IsVoid: case UTT_IsIntegral: case UTT_IsFloatingPoint: case UTT_IsArray: case UTT_IsPointer: case UTT_IsLvalueReference: case UTT_IsRvalueReference: case UTT_IsMemberFunctionPointer: case UTT_IsMemberObjectPointer: case UTT_IsEnum: case UTT_IsUnion: case UTT_IsClass: case UTT_IsFunction: case UTT_IsReference: case UTT_IsArithmetic: case UTT_IsFundamental: case UTT_IsObject: case UTT_IsScalar: case UTT_IsCompound: case UTT_IsMemberPointer: // Fall-through // These traits are modeled on type predicates in C++0x [meta.unary.prop] // which requires some of its traits to have the complete type. However, // the completeness of the type cannot impact these traits' semantics, and // so they don't require it. This matches the comments on these traits in // Table 49. case UTT_IsConst: case UTT_IsVolatile: case UTT_IsSigned: case UTT_IsUnsigned: // This type trait always returns false, checking the type is moot. case UTT_IsInterfaceClass: return true; // C++14 [meta.unary.prop]: // If T is a non-union class type, T shall be a complete type. case UTT_IsEmpty: case UTT_IsPolymorphic: case UTT_IsAbstract: if (const auto *RD = ArgTy->getAsCXXRecordDecl()) if (!RD->isUnion()) return !S.RequireCompleteType( Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr); return true; // C++14 [meta.unary.prop]: // If T is a class type, T shall be a complete type. case UTT_IsFinal: case UTT_IsSealed: if (ArgTy->getAsCXXRecordDecl()) return !S.RequireCompleteType( Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr); return true; // C++0x [meta.unary.prop] Table 49 requires the following traits to be // applied to a complete type. case UTT_IsTrivial: case UTT_IsTriviallyCopyable: case UTT_IsStandardLayout: case UTT_IsPOD: case UTT_IsLiteral: case UTT_IsDestructible: case UTT_IsNothrowDestructible: // Fall-through // These trait expressions are designed to help implement predicates in // [meta.unary.prop] despite not being named the same. They are specified // by both GCC and the Embarcadero C++ compiler, and require the complete // type due to the overarching C++0x type predicates being implemented // requiring the complete type. case UTT_HasNothrowAssign: case UTT_HasNothrowMoveAssign: case UTT_HasNothrowConstructor: case UTT_HasNothrowCopy: case UTT_HasTrivialAssign: case UTT_HasTrivialMoveAssign: case UTT_HasTrivialDefaultConstructor: case UTT_HasTrivialMoveConstructor: case UTT_HasTrivialCopy: case UTT_HasTrivialDestructor: case UTT_HasVirtualDestructor: // Arrays of unknown bound are expressly allowed. QualType ElTy = ArgTy; if (ArgTy->isIncompleteArrayType()) ElTy = S.Context.getAsArrayType(ArgTy)->getElementType(); // The void type is expressly allowed. if (ElTy->isVoidType()) return true; return !S.RequireCompleteType( Loc, ElTy, diag::err_incomplete_type_used_in_type_trait_expr); } } static bool HasNoThrowOperator(const RecordType *RT, OverloadedOperatorKind Op, Sema &Self, SourceLocation KeyLoc, ASTContext &C, bool (CXXRecordDecl::*HasTrivial)() const, bool (CXXRecordDecl::*HasNonTrivial)() const, bool (CXXMethodDecl::*IsDesiredOp)() const) { CXXRecordDecl *RD = cast(RT->getDecl()); if ((RD->*HasTrivial)() && !(RD->*HasNonTrivial)()) return true; DeclarationName Name = C.DeclarationNames.getCXXOperatorName(Op); DeclarationNameInfo NameInfo(Name, KeyLoc); LookupResult Res(Self, NameInfo, Sema::LookupOrdinaryName); if (Self.LookupQualifiedName(Res, RD)) { bool FoundOperator = false; Res.suppressDiagnostics(); for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end(); Op != OpEnd; ++Op) { if (isa(*Op)) continue; CXXMethodDecl *Operator = cast(*Op); if((Operator->*IsDesiredOp)()) { FoundOperator = true; const FunctionProtoType *CPT = Operator->getType()->getAs(); CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); if (!CPT || !CPT->isNothrow(C)) return false; } } return FoundOperator; } return false; } static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT, SourceLocation KeyLoc, QualType T) { assert(!T->isDependentType() && "Cannot evaluate traits of dependent type"); ASTContext &C = Self.Context; switch(UTT) { default: llvm_unreachable("not a UTT"); // Type trait expressions corresponding to the primary type category // predicates in C++0x [meta.unary.cat]. case UTT_IsVoid: return T->isVoidType(); case UTT_IsIntegral: return T->isIntegralType(C); case UTT_IsFloatingPoint: return T->isFloatingType(); case UTT_IsArray: return T->isArrayType(); case UTT_IsPointer: return T->isPointerType(); case UTT_IsLvalueReference: return T->isLValueReferenceType(); case UTT_IsRvalueReference: return T->isRValueReferenceType(); case UTT_IsMemberFunctionPointer: return T->isMemberFunctionPointerType(); case UTT_IsMemberObjectPointer: return T->isMemberDataPointerType(); case UTT_IsEnum: return T->isEnumeralType(); case UTT_IsUnion: return T->isUnionType(); case UTT_IsClass: return T->isClassType() || T->isStructureType() || T->isInterfaceType(); case UTT_IsFunction: return T->isFunctionType(); // Type trait expressions which correspond to the convenient composition // predicates in C++0x [meta.unary.comp]. case UTT_IsReference: return T->isReferenceType(); case UTT_IsArithmetic: return T->isArithmeticType() && !T->isEnumeralType(); case UTT_IsFundamental: return T->isFundamentalType(); case UTT_IsObject: return T->isObjectType(); case UTT_IsScalar: // Note: semantic analysis depends on Objective-C lifetime types to be // considered scalar types. However, such types do not actually behave // like scalar types at run time (since they may require retain/release // operations), so we report them as non-scalar. if (T->isObjCLifetimeType()) { switch (T.getObjCLifetime()) { case Qualifiers::OCL_None: case Qualifiers::OCL_ExplicitNone: return true; case Qualifiers::OCL_Strong: case Qualifiers::OCL_Weak: case Qualifiers::OCL_Autoreleasing: return false; } } return T->isScalarType(); case UTT_IsCompound: return T->isCompoundType(); case UTT_IsMemberPointer: return T->isMemberPointerType(); // Type trait expressions which correspond to the type property predicates // in C++0x [meta.unary.prop]. case UTT_IsConst: return T.isConstQualified(); case UTT_IsVolatile: return T.isVolatileQualified(); case UTT_IsTrivial: return T.isTrivialType(C); case UTT_IsTriviallyCopyable: return T.isTriviallyCopyableType(C); case UTT_IsStandardLayout: return T->isStandardLayoutType(); case UTT_IsPOD: return T.isPODType(C); case UTT_IsLiteral: return T->isLiteralType(C); case UTT_IsEmpty: if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) return !RD->isUnion() && RD->isEmpty(); return false; case UTT_IsPolymorphic: if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) return !RD->isUnion() && RD->isPolymorphic(); return false; case UTT_IsAbstract: if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) return !RD->isUnion() && RD->isAbstract(); return false; // __is_interface_class only returns true when CL is invoked in /CLR mode and // even then only when it is used with the 'interface struct ...' syntax // Clang doesn't support /CLR which makes this type trait moot. case UTT_IsInterfaceClass: return false; case UTT_IsFinal: case UTT_IsSealed: if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) return RD->hasAttr(); return false; case UTT_IsSigned: return T->isSignedIntegerType(); case UTT_IsUnsigned: return T->isUnsignedIntegerType(); // Type trait expressions which query classes regarding their construction, // destruction, and copying. Rather than being based directly on the // related type predicates in the standard, they are specified by both // GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those // specifications. // // 1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html // 2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index // // Note that these builtins do not behave as documented in g++: if a class // has both a trivial and a non-trivial special member of a particular kind, // they return false! For now, we emulate this behavior. // FIXME: This appears to be a g++ bug: more complex cases reveal that it // does not correctly compute triviality in the presence of multiple special // members of the same kind. Revisit this once the g++ bug is fixed. case UTT_HasTrivialDefaultConstructor: // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: // If __is_pod (type) is true then the trait is true, else if type is // a cv class or union type (or array thereof) with a trivial default // constructor ([class.ctor]) then the trait is true, else it is false. if (T.isPODType(C)) return true; if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) return RD->hasTrivialDefaultConstructor() && !RD->hasNonTrivialDefaultConstructor(); return false; case UTT_HasTrivialMoveConstructor: // This trait is implemented by MSVC 2012 and needed to parse the // standard library headers. Specifically this is used as the logic // behind std::is_trivially_move_constructible (20.9.4.3). if (T.isPODType(C)) return true; if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) return RD->hasTrivialMoveConstructor() && !RD->hasNonTrivialMoveConstructor(); return false; case UTT_HasTrivialCopy: // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: // If __is_pod (type) is true or type is a reference type then // the trait is true, else if type is a cv class or union type // with a trivial copy constructor ([class.copy]) then the trait // is true, else it is false. if (T.isPODType(C) || T->isReferenceType()) return true; if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) return RD->hasTrivialCopyConstructor() && !RD->hasNonTrivialCopyConstructor(); return false; case UTT_HasTrivialMoveAssign: // This trait is implemented by MSVC 2012 and needed to parse the // standard library headers. Specifically it is used as the logic // behind std::is_trivially_move_assignable (20.9.4.3) if (T.isPODType(C)) return true; if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) return RD->hasTrivialMoveAssignment() && !RD->hasNonTrivialMoveAssignment(); return false; case UTT_HasTrivialAssign: // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: // If type is const qualified or is a reference type then the // trait is false. Otherwise if __is_pod (type) is true then the // trait is true, else if type is a cv class or union type with // a trivial copy assignment ([class.copy]) then the trait is // true, else it is false. // Note: the const and reference restrictions are interesting, // given that const and reference members don't prevent a class // from having a trivial copy assignment operator (but do cause // errors if the copy assignment operator is actually used, q.v. // [class.copy]p12). if (T.isConstQualified()) return false; if (T.isPODType(C)) return true; if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) return RD->hasTrivialCopyAssignment() && !RD->hasNonTrivialCopyAssignment(); return false; case UTT_IsDestructible: case UTT_IsNothrowDestructible: // C++14 [meta.unary.prop]: // For reference types, is_destructible::value is true. if (T->isReferenceType()) return true; // Objective-C++ ARC: autorelease types don't require destruction. if (T->isObjCLifetimeType() && T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing) return true; // C++14 [meta.unary.prop]: // For incomplete types and function types, is_destructible::value is // false. if (T->isIncompleteType() || T->isFunctionType()) return false; // C++14 [meta.unary.prop]: // For object types and given U equal to remove_all_extents_t, if the // expression std::declval().~U() is well-formed when treated as an // unevaluated operand (Clause 5), then is_destructible::value is true if (auto *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) { CXXDestructorDecl *Destructor = Self.LookupDestructor(RD); if (!Destructor) return false; // C++14 [dcl.fct.def.delete]p2: // A program that refers to a deleted function implicitly or // explicitly, other than to declare it, is ill-formed. if (Destructor->isDeleted()) return false; if (C.getLangOpts().AccessControl && Destructor->getAccess() != AS_public) return false; if (UTT == UTT_IsNothrowDestructible) { const FunctionProtoType *CPT = Destructor->getType()->getAs(); CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); if (!CPT || !CPT->isNothrow(C)) return false; } } return true; case UTT_HasTrivialDestructor: // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html // If __is_pod (type) is true or type is a reference type // then the trait is true, else if type is a cv class or union // type (or array thereof) with a trivial destructor // ([class.dtor]) then the trait is true, else it is // false. if (T.isPODType(C) || T->isReferenceType()) return true; // Objective-C++ ARC: autorelease types don't require destruction. if (T->isObjCLifetimeType() && T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing) return true; if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) return RD->hasTrivialDestructor(); return false; // TODO: Propagate nothrowness for implicitly declared special members. case UTT_HasNothrowAssign: // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: // If type is const qualified or is a reference type then the // trait is false. Otherwise if __has_trivial_assign (type) // is true then the trait is true, else if type is a cv class // or union type with copy assignment operators that are known // not to throw an exception then the trait is true, else it is // false. if (C.getBaseElementType(T).isConstQualified()) return false; if (T->isReferenceType()) return false; if (T.isPODType(C) || T->isObjCLifetimeType()) return true; if (const RecordType *RT = T->getAs()) return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C, &CXXRecordDecl::hasTrivialCopyAssignment, &CXXRecordDecl::hasNonTrivialCopyAssignment, &CXXMethodDecl::isCopyAssignmentOperator); return false; case UTT_HasNothrowMoveAssign: // This trait is implemented by MSVC 2012 and needed to parse the // standard library headers. Specifically this is used as the logic // behind std::is_nothrow_move_assignable (20.9.4.3). if (T.isPODType(C)) return true; if (const RecordType *RT = C.getBaseElementType(T)->getAs()) return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C, &CXXRecordDecl::hasTrivialMoveAssignment, &CXXRecordDecl::hasNonTrivialMoveAssignment, &CXXMethodDecl::isMoveAssignmentOperator); return false; case UTT_HasNothrowCopy: // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: // If __has_trivial_copy (type) is true then the trait is true, else // if type is a cv class or union type with copy constructors that are // known not to throw an exception then the trait is true, else it is // false. if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType()) return true; if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) { if (RD->hasTrivialCopyConstructor() && !RD->hasNonTrivialCopyConstructor()) return true; bool FoundConstructor = false; unsigned FoundTQs; for (const auto *ND : Self.LookupConstructors(RD)) { // A template constructor is never a copy constructor. // FIXME: However, it may actually be selected at the actual overload // resolution point. if (isa(ND)) continue; const CXXConstructorDecl *Constructor = cast(ND); if (Constructor->isCopyConstructor(FoundTQs)) { FoundConstructor = true; const FunctionProtoType *CPT = Constructor->getType()->getAs(); CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); if (!CPT) return false; // TODO: check whether evaluating default arguments can throw. // For now, we'll be conservative and assume that they can throw. if (!CPT->isNothrow(C) || CPT->getNumParams() > 1) return false; } } return FoundConstructor; } return false; case UTT_HasNothrowConstructor: // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html // If __has_trivial_constructor (type) is true then the trait is // true, else if type is a cv class or union type (or array // thereof) with a default constructor that is known not to // throw an exception then the trait is true, else it is false. if (T.isPODType(C) || T->isObjCLifetimeType()) return true; if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) { if (RD->hasTrivialDefaultConstructor() && !RD->hasNonTrivialDefaultConstructor()) return true; bool FoundConstructor = false; for (const auto *ND : Self.LookupConstructors(RD)) { // FIXME: In C++0x, a constructor template can be a default constructor. if (isa(ND)) continue; const CXXConstructorDecl *Constructor = cast(ND); if (Constructor->isDefaultConstructor()) { FoundConstructor = true; const FunctionProtoType *CPT = Constructor->getType()->getAs(); CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); if (!CPT) return false; // FIXME: check whether evaluating default arguments can throw. // For now, we'll be conservative and assume that they can throw. if (!CPT->isNothrow(C) || CPT->getNumParams() > 0) return false; } } return FoundConstructor; } return false; case UTT_HasVirtualDestructor: // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: // If type is a class type with a virtual destructor ([class.dtor]) // then the trait is true, else it is false. if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD)) return Destructor->isVirtual(); return false; // These type trait expressions are modeled on the specifications for the // Embarcadero C++0x type trait functions: // http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index case UTT_IsCompleteType: // http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_): // Returns True if and only if T is a complete type at the point of the // function call. return !T->isIncompleteType(); } } /// \brief Determine whether T has a non-trivial Objective-C lifetime in /// ARC mode. static bool hasNontrivialObjCLifetime(QualType T) { switch (T.getObjCLifetime()) { case Qualifiers::OCL_ExplicitNone: return false; case Qualifiers::OCL_Strong: case Qualifiers::OCL_Weak: case Qualifiers::OCL_Autoreleasing: return true; case Qualifiers::OCL_None: return T->isObjCLifetimeType(); } llvm_unreachable("Unknown ObjC lifetime qualifier"); } static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT, QualType RhsT, SourceLocation KeyLoc); static bool evaluateTypeTrait(Sema &S, TypeTrait Kind, SourceLocation KWLoc, ArrayRef Args, SourceLocation RParenLoc) { if (Kind <= UTT_Last) return EvaluateUnaryTypeTrait(S, Kind, KWLoc, Args[0]->getType()); if (Kind <= BTT_Last) return EvaluateBinaryTypeTrait(S, Kind, Args[0]->getType(), Args[1]->getType(), RParenLoc); switch (Kind) { case clang::TT_IsConstructible: case clang::TT_IsNothrowConstructible: case clang::TT_IsTriviallyConstructible: { // C++11 [meta.unary.prop]: // is_trivially_constructible is defined as: // // is_constructible::value is true and the variable // definition for is_constructible, as defined below, is known to call // no operation that is not trivial. // // The predicate condition for a template specialization // is_constructible shall be satisfied if and only if the // following variable definition would be well-formed for some invented // variable t: // // T t(create()...); assert(!Args.empty()); // Precondition: T and all types in the parameter pack Args shall be // complete types, (possibly cv-qualified) void, or arrays of // unknown bound. for (const auto *TSI : Args) { QualType ArgTy = TSI->getType(); if (ArgTy->isVoidType() || ArgTy->isIncompleteArrayType()) continue; if (S.RequireCompleteType(KWLoc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr)) return false; } // Make sure the first argument is not incomplete nor a function type. QualType T = Args[0]->getType(); if (T->isIncompleteType() || T->isFunctionType()) return false; // Make sure the first argument is not an abstract type. CXXRecordDecl *RD = T->getAsCXXRecordDecl(); if (RD && RD->isAbstract()) return false; SmallVector OpaqueArgExprs; SmallVector ArgExprs; ArgExprs.reserve(Args.size() - 1); for (unsigned I = 1, N = Args.size(); I != N; ++I) { QualType ArgTy = Args[I]->getType(); if (ArgTy->isObjectType() || ArgTy->isFunctionType()) ArgTy = S.Context.getRValueReferenceType(ArgTy); OpaqueArgExprs.push_back( OpaqueValueExpr(Args[I]->getTypeLoc().getLocStart(), ArgTy.getNonLValueExprType(S.Context), Expr::getValueKindForType(ArgTy))); } for (Expr &E : OpaqueArgExprs) ArgExprs.push_back(&E); // Perform the initialization in an unevaluated context within a SFINAE // trap at translation unit scope. EnterExpressionEvaluationContext Unevaluated(S, Sema::Unevaluated); Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true); Sema::ContextRAII TUContext(S, S.Context.getTranslationUnitDecl()); InitializedEntity To(InitializedEntity::InitializeTemporary(Args[0])); InitializationKind InitKind(InitializationKind::CreateDirect(KWLoc, KWLoc, RParenLoc)); InitializationSequence Init(S, To, InitKind, ArgExprs); if (Init.Failed()) return false; ExprResult Result = Init.Perform(S, To, InitKind, ArgExprs); if (Result.isInvalid() || SFINAE.hasErrorOccurred()) return false; if (Kind == clang::TT_IsConstructible) return true; if (Kind == clang::TT_IsNothrowConstructible) return S.canThrow(Result.get()) == CT_Cannot; if (Kind == clang::TT_IsTriviallyConstructible) { // Under Objective-C ARC, if the destination has non-trivial Objective-C // lifetime, this is a non-trivial construction. if (S.getLangOpts().ObjCAutoRefCount && hasNontrivialObjCLifetime(T.getNonReferenceType())) return false; // The initialization succeeded; now make sure there are no non-trivial // calls. return !Result.get()->hasNonTrivialCall(S.Context); } llvm_unreachable("unhandled type trait"); return false; } default: llvm_unreachable("not a TT"); } return false; } ExprResult Sema::BuildTypeTrait(TypeTrait Kind, SourceLocation KWLoc, ArrayRef Args, SourceLocation RParenLoc) { QualType ResultType = Context.getLogicalOperationType(); if (Kind <= UTT_Last && !CheckUnaryTypeTraitTypeCompleteness( *this, Kind, KWLoc, Args[0]->getType())) return ExprError(); bool Dependent = false; for (unsigned I = 0, N = Args.size(); I != N; ++I) { if (Args[I]->getType()->isDependentType()) { Dependent = true; break; } } bool Result = false; if (!Dependent) Result = evaluateTypeTrait(*this, Kind, KWLoc, Args, RParenLoc); return TypeTraitExpr::Create(Context, ResultType, KWLoc, Kind, Args, RParenLoc, Result); } ExprResult Sema::ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc, ArrayRef Args, SourceLocation RParenLoc) { SmallVector ConvertedArgs; ConvertedArgs.reserve(Args.size()); for (unsigned I = 0, N = Args.size(); I != N; ++I) { TypeSourceInfo *TInfo; QualType T = GetTypeFromParser(Args[I], &TInfo); if (!TInfo) TInfo = Context.getTrivialTypeSourceInfo(T, KWLoc); ConvertedArgs.push_back(TInfo); } return BuildTypeTrait(Kind, KWLoc, ConvertedArgs, RParenLoc); } static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT, QualType RhsT, SourceLocation KeyLoc) { assert(!LhsT->isDependentType() && !RhsT->isDependentType() && "Cannot evaluate traits of dependent types"); switch(BTT) { case BTT_IsBaseOf: { // C++0x [meta.rel]p2 // Base is a base class of Derived without regard to cv-qualifiers or // Base and Derived are not unions and name the same class type without // regard to cv-qualifiers. const RecordType *lhsRecord = LhsT->getAs(); if (!lhsRecord) return false; const RecordType *rhsRecord = RhsT->getAs(); if (!rhsRecord) return false; assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT) == (lhsRecord == rhsRecord)); if (lhsRecord == rhsRecord) return !lhsRecord->getDecl()->isUnion(); // C++0x [meta.rel]p2: // If Base and Derived are class types and are different types // (ignoring possible cv-qualifiers) then Derived shall be a // complete type. if (Self.RequireCompleteType(KeyLoc, RhsT, diag::err_incomplete_type_used_in_type_trait_expr)) return false; return cast(rhsRecord->getDecl()) ->isDerivedFrom(cast(lhsRecord->getDecl())); } case BTT_IsSame: return Self.Context.hasSameType(LhsT, RhsT); case BTT_TypeCompatible: return Self.Context.typesAreCompatible(LhsT.getUnqualifiedType(), RhsT.getUnqualifiedType()); case BTT_IsConvertible: case BTT_IsConvertibleTo: { // C++0x [meta.rel]p4: // Given the following function prototype: // // template // typename add_rvalue_reference::type create(); // // the predicate condition for a template specialization // is_convertible shall be satisfied if and only if // the return expression in the following code would be // well-formed, including any implicit conversions to the return // type of the function: // // To test() { // return create(); // } // // Access checking is performed as if in a context unrelated to To and // From. Only the validity of the immediate context of the expression // of the return-statement (including conversions to the return type) // is considered. // // We model the initialization as a copy-initialization of a temporary // of the appropriate type, which for this expression is identical to the // return statement (since NRVO doesn't apply). // Functions aren't allowed to return function or array types. if (RhsT->isFunctionType() || RhsT->isArrayType()) return false; // A return statement in a void function must have void type. if (RhsT->isVoidType()) return LhsT->isVoidType(); // A function definition requires a complete, non-abstract return type. if (!Self.isCompleteType(KeyLoc, RhsT) || Self.isAbstractType(KeyLoc, RhsT)) return false; // Compute the result of add_rvalue_reference. if (LhsT->isObjectType() || LhsT->isFunctionType()) LhsT = Self.Context.getRValueReferenceType(LhsT); // Build a fake source and destination for initialization. InitializedEntity To(InitializedEntity::InitializeTemporary(RhsT)); OpaqueValueExpr From(KeyLoc, LhsT.getNonLValueExprType(Self.Context), Expr::getValueKindForType(LhsT)); Expr *FromPtr = &From; InitializationKind Kind(InitializationKind::CreateCopy(KeyLoc, SourceLocation())); // Perform the initialization in an unevaluated context within a SFINAE // trap at translation unit scope. EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated); Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true); Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl()); InitializationSequence Init(Self, To, Kind, FromPtr); if (Init.Failed()) return false; ExprResult Result = Init.Perform(Self, To, Kind, FromPtr); return !Result.isInvalid() && !SFINAE.hasErrorOccurred(); } case BTT_IsAssignable: case BTT_IsNothrowAssignable: case BTT_IsTriviallyAssignable: { // C++11 [meta.unary.prop]p3: // is_trivially_assignable is defined as: // is_assignable::value is true and the assignment, as defined by // is_assignable, is known to call no operation that is not trivial // // is_assignable is defined as: // The expression declval() = declval() is well-formed when // treated as an unevaluated operand (Clause 5). // // For both, T and U shall be complete types, (possibly cv-qualified) // void, or arrays of unknown bound. if (!LhsT->isVoidType() && !LhsT->isIncompleteArrayType() && Self.RequireCompleteType(KeyLoc, LhsT, diag::err_incomplete_type_used_in_type_trait_expr)) return false; if (!RhsT->isVoidType() && !RhsT->isIncompleteArrayType() && Self.RequireCompleteType(KeyLoc, RhsT, diag::err_incomplete_type_used_in_type_trait_expr)) return false; // cv void is never assignable. if (LhsT->isVoidType() || RhsT->isVoidType()) return false; // Build expressions that emulate the effect of declval() and // declval(). if (LhsT->isObjectType() || LhsT->isFunctionType()) LhsT = Self.Context.getRValueReferenceType(LhsT); if (RhsT->isObjectType() || RhsT->isFunctionType()) RhsT = Self.Context.getRValueReferenceType(RhsT); OpaqueValueExpr Lhs(KeyLoc, LhsT.getNonLValueExprType(Self.Context), Expr::getValueKindForType(LhsT)); OpaqueValueExpr Rhs(KeyLoc, RhsT.getNonLValueExprType(Self.Context), Expr::getValueKindForType(RhsT)); // Attempt the assignment in an unevaluated context within a SFINAE // trap at translation unit scope. EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated); Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true); Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl()); ExprResult Result = Self.BuildBinOp(/*S=*/nullptr, KeyLoc, BO_Assign, &Lhs, &Rhs); if (Result.isInvalid() || SFINAE.hasErrorOccurred()) return false; if (BTT == BTT_IsAssignable) return true; if (BTT == BTT_IsNothrowAssignable) return Self.canThrow(Result.get()) == CT_Cannot; if (BTT == BTT_IsTriviallyAssignable) { // Under Objective-C ARC, if the destination has non-trivial Objective-C // lifetime, this is a non-trivial assignment. if (Self.getLangOpts().ObjCAutoRefCount && hasNontrivialObjCLifetime(LhsT.getNonReferenceType())) return false; return !Result.get()->hasNonTrivialCall(Self.Context); } llvm_unreachable("unhandled type trait"); return false; } default: llvm_unreachable("not a BTT"); } llvm_unreachable("Unknown type trait or not implemented"); } ExprResult Sema::ActOnArrayTypeTrait(ArrayTypeTrait ATT, SourceLocation KWLoc, ParsedType Ty, Expr* DimExpr, SourceLocation RParen) { TypeSourceInfo *TSInfo; QualType T = GetTypeFromParser(Ty, &TSInfo); if (!TSInfo) TSInfo = Context.getTrivialTypeSourceInfo(T); return BuildArrayTypeTrait(ATT, KWLoc, TSInfo, DimExpr, RParen); } static uint64_t EvaluateArrayTypeTrait(Sema &Self, ArrayTypeTrait ATT, QualType T, Expr *DimExpr, SourceLocation KeyLoc) { assert(!T->isDependentType() && "Cannot evaluate traits of dependent type"); switch(ATT) { case ATT_ArrayRank: if (T->isArrayType()) { unsigned Dim = 0; while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { ++Dim; T = AT->getElementType(); } return Dim; } return 0; case ATT_ArrayExtent: { llvm::APSInt Value; uint64_t Dim; if (Self.VerifyIntegerConstantExpression(DimExpr, &Value, diag::err_dimension_expr_not_constant_integer, false).isInvalid()) return 0; if (Value.isSigned() && Value.isNegative()) { Self.Diag(KeyLoc, diag::err_dimension_expr_not_constant_integer) << DimExpr->getSourceRange(); return 0; } Dim = Value.getLimitedValue(); if (T->isArrayType()) { unsigned D = 0; bool Matched = false; while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { if (Dim == D) { Matched = true; break; } ++D; T = AT->getElementType(); } if (Matched && T->isArrayType()) { if (const ConstantArrayType *CAT = Self.Context.getAsConstantArrayType(T)) return CAT->getSize().getLimitedValue(); } } return 0; } } llvm_unreachable("Unknown type trait or not implemented"); } ExprResult Sema::BuildArrayTypeTrait(ArrayTypeTrait ATT, SourceLocation KWLoc, TypeSourceInfo *TSInfo, Expr* DimExpr, SourceLocation RParen) { QualType T = TSInfo->getType(); // FIXME: This should likely be tracked as an APInt to remove any host // assumptions about the width of size_t on the target. uint64_t Value = 0; if (!T->isDependentType()) Value = EvaluateArrayTypeTrait(*this, ATT, T, DimExpr, KWLoc); // While the specification for these traits from the Embarcadero C++ // compiler's documentation says the return type is 'unsigned int', Clang // returns 'size_t'. On Windows, the primary platform for the Embarcadero // compiler, there is no difference. On several other platforms this is an // important distinction. return new (Context) ArrayTypeTraitExpr(KWLoc, ATT, TSInfo, Value, DimExpr, RParen, Context.getSizeType()); } ExprResult Sema::ActOnExpressionTrait(ExpressionTrait ET, SourceLocation KWLoc, Expr *Queried, SourceLocation RParen) { // If error parsing the expression, ignore. if (!Queried) return ExprError(); ExprResult Result = BuildExpressionTrait(ET, KWLoc, Queried, RParen); return Result; } static bool EvaluateExpressionTrait(ExpressionTrait ET, Expr *E) { switch (ET) { case ET_IsLValueExpr: return E->isLValue(); case ET_IsRValueExpr: return E->isRValue(); } llvm_unreachable("Expression trait not covered by switch"); } ExprResult Sema::BuildExpressionTrait(ExpressionTrait ET, SourceLocation KWLoc, Expr *Queried, SourceLocation RParen) { if (Queried->isTypeDependent()) { // Delay type-checking for type-dependent expressions. } else if (Queried->getType()->isPlaceholderType()) { ExprResult PE = CheckPlaceholderExpr(Queried); if (PE.isInvalid()) return ExprError(); return BuildExpressionTrait(ET, KWLoc, PE.get(), RParen); } bool Value = EvaluateExpressionTrait(ET, Queried); return new (Context) ExpressionTraitExpr(KWLoc, ET, Queried, Value, RParen, Context.BoolTy); } QualType Sema::CheckPointerToMemberOperands(ExprResult &LHS, ExprResult &RHS, ExprValueKind &VK, SourceLocation Loc, bool isIndirect) { assert(!LHS.get()->getType()->isPlaceholderType() && !RHS.get()->getType()->isPlaceholderType() && "placeholders should have been weeded out by now"); // The LHS undergoes lvalue conversions if this is ->*. if (isIndirect) { LHS = DefaultLvalueConversion(LHS.get()); if (LHS.isInvalid()) return QualType(); } // The RHS always undergoes lvalue conversions. RHS = DefaultLvalueConversion(RHS.get()); if (RHS.isInvalid()) return QualType(); const char *OpSpelling = isIndirect ? "->*" : ".*"; // C++ 5.5p2 // The binary operator .* [p3: ->*] binds its second operand, which shall // be of type "pointer to member of T" (where T is a completely-defined // class type) [...] QualType RHSType = RHS.get()->getType(); const MemberPointerType *MemPtr = RHSType->getAs(); if (!MemPtr) { Diag(Loc, diag::err_bad_memptr_rhs) << OpSpelling << RHSType << RHS.get()->getSourceRange(); return QualType(); } QualType Class(MemPtr->getClass(), 0); // Note: C++ [expr.mptr.oper]p2-3 says that the class type into which the // member pointer points must be completely-defined. However, there is no // reason for this semantic distinction, and the rule is not enforced by // other compilers. Therefore, we do not check this property, as it is // likely to be considered a defect. // C++ 5.5p2 // [...] to its first operand, which shall be of class T or of a class of // which T is an unambiguous and accessible base class. [p3: a pointer to // such a class] QualType LHSType = LHS.get()->getType(); if (isIndirect) { if (const PointerType *Ptr = LHSType->getAs()) LHSType = Ptr->getPointeeType(); else { Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling << 1 << LHSType << FixItHint::CreateReplacement(SourceRange(Loc), ".*"); return QualType(); } } if (!Context.hasSameUnqualifiedType(Class, LHSType)) { // If we want to check the hierarchy, we need a complete type. if (RequireCompleteType(Loc, LHSType, diag::err_bad_memptr_lhs, OpSpelling, (int)isIndirect)) { return QualType(); } if (!IsDerivedFrom(Loc, LHSType, Class)) { Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling << (int)isIndirect << LHS.get()->getType(); return QualType(); } CXXCastPath BasePath; if (CheckDerivedToBaseConversion(LHSType, Class, Loc, SourceRange(LHS.get()->getLocStart(), RHS.get()->getLocEnd()), &BasePath)) return QualType(); // Cast LHS to type of use. QualType UseType = isIndirect ? Context.getPointerType(Class) : Class; ExprValueKind VK = isIndirect ? VK_RValue : LHS.get()->getValueKind(); LHS = ImpCastExprToType(LHS.get(), UseType, CK_DerivedToBase, VK, &BasePath); } if (isa(RHS.get()->IgnoreParens())) { // Diagnose use of pointer-to-member type which when used as // the functional cast in a pointer-to-member expression. Diag(Loc, diag::err_pointer_to_member_type) << isIndirect; return QualType(); } // C++ 5.5p2 // The result is an object or a function of the type specified by the // second operand. // The cv qualifiers are the union of those in the pointer and the left side, // in accordance with 5.5p5 and 5.2.5. QualType Result = MemPtr->getPointeeType(); Result = Context.getCVRQualifiedType(Result, LHSType.getCVRQualifiers()); // C++0x [expr.mptr.oper]p6: // In a .* expression whose object expression is an rvalue, the program is // ill-formed if the second operand is a pointer to member function with // ref-qualifier &. In a ->* expression or in a .* expression whose object // expression is an lvalue, the program is ill-formed if the second operand // is a pointer to member function with ref-qualifier &&. if (const FunctionProtoType *Proto = Result->getAs()) { switch (Proto->getRefQualifier()) { case RQ_None: // Do nothing break; case RQ_LValue: if (!isIndirect && !LHS.get()->Classify(Context).isLValue()) Diag(Loc, diag::err_pointer_to_member_oper_value_classify) << RHSType << 1 << LHS.get()->getSourceRange(); break; case RQ_RValue: if (isIndirect || !LHS.get()->Classify(Context).isRValue()) Diag(Loc, diag::err_pointer_to_member_oper_value_classify) << RHSType << 0 << LHS.get()->getSourceRange(); break; } } // C++ [expr.mptr.oper]p6: // The result of a .* expression whose second operand is a pointer // to a data member is of the same value category as its // first operand. The result of a .* expression whose second // operand is a pointer to a member function is a prvalue. The // result of an ->* expression is an lvalue if its second operand // is a pointer to data member and a prvalue otherwise. if (Result->isFunctionType()) { VK = VK_RValue; return Context.BoundMemberTy; } else if (isIndirect) { VK = VK_LValue; } else { VK = LHS.get()->getValueKind(); } return Result; } /// \brief Try to convert a type to another according to C++11 5.16p3. /// /// This is part of the parameter validation for the ? operator. If either /// value operand is a class type, the two operands are attempted to be /// converted to each other. This function does the conversion in one direction. /// It returns true if the program is ill-formed and has already been diagnosed /// as such. static bool TryClassUnification(Sema &Self, Expr *From, Expr *To, SourceLocation QuestionLoc, bool &HaveConversion, QualType &ToType) { HaveConversion = false; ToType = To->getType(); InitializationKind Kind = InitializationKind::CreateCopy(To->getLocStart(), SourceLocation()); // C++11 5.16p3 // The process for determining whether an operand expression E1 of type T1 // can be converted to match an operand expression E2 of type T2 is defined // as follows: // -- If E2 is an lvalue: E1 can be converted to match E2 if E1 can be // implicitly converted to type "lvalue reference to T2", subject to the // constraint that in the conversion the reference must bind directly to // an lvalue. // -- If E2 is an xvalue: E1 can be converted to match E2 if E1 can be // implicitly conveted to the type "rvalue reference to R2", subject to // the constraint that the reference must bind directly. if (To->isLValue() || To->isXValue()) { QualType T = To->isLValue() ? Self.Context.getLValueReferenceType(ToType) : Self.Context.getRValueReferenceType(ToType); InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); InitializationSequence InitSeq(Self, Entity, Kind, From); if (InitSeq.isDirectReferenceBinding()) { ToType = T; HaveConversion = true; return false; } if (InitSeq.isAmbiguous()) return InitSeq.Diagnose(Self, Entity, Kind, From); } // -- If E2 is an rvalue, or if the conversion above cannot be done: // -- if E1 and E2 have class type, and the underlying class types are // the same or one is a base class of the other: QualType FTy = From->getType(); QualType TTy = To->getType(); const RecordType *FRec = FTy->getAs(); const RecordType *TRec = TTy->getAs(); bool FDerivedFromT = FRec && TRec && FRec != TRec && Self.IsDerivedFrom(QuestionLoc, FTy, TTy); if (FRec && TRec && (FRec == TRec || FDerivedFromT || Self.IsDerivedFrom(QuestionLoc, TTy, FTy))) { // E1 can be converted to match E2 if the class of T2 is the // same type as, or a base class of, the class of T1, and // [cv2 > cv1]. if (FRec == TRec || FDerivedFromT) { if (TTy.isAtLeastAsQualifiedAs(FTy)) { InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); InitializationSequence InitSeq(Self, Entity, Kind, From); if (InitSeq) { HaveConversion = true; return false; } if (InitSeq.isAmbiguous()) return InitSeq.Diagnose(Self, Entity, Kind, From); } } return false; } // -- Otherwise: E1 can be converted to match E2 if E1 can be // implicitly converted to the type that expression E2 would have // if E2 were converted to an rvalue (or the type it has, if E2 is // an rvalue). // // This actually refers very narrowly to the lvalue-to-rvalue conversion, not // to the array-to-pointer or function-to-pointer conversions. if (!TTy->getAs()) TTy = TTy.getUnqualifiedType(); InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); InitializationSequence InitSeq(Self, Entity, Kind, From); HaveConversion = !InitSeq.Failed(); ToType = TTy; if (InitSeq.isAmbiguous()) return InitSeq.Diagnose(Self, Entity, Kind, From); return false; } /// \brief Try to find a common type for two according to C++0x 5.16p5. /// /// This is part of the parameter validation for the ? operator. If either /// value operand is a class type, overload resolution is used to find a /// conversion to a common type. static bool FindConditionalOverload(Sema &Self, ExprResult &LHS, ExprResult &RHS, SourceLocation QuestionLoc) { Expr *Args[2] = { LHS.get(), RHS.get() }; OverloadCandidateSet CandidateSet(QuestionLoc, OverloadCandidateSet::CSK_Operator); Self.AddBuiltinOperatorCandidates(OO_Conditional, QuestionLoc, Args, CandidateSet); OverloadCandidateSet::iterator Best; switch (CandidateSet.BestViableFunction(Self, QuestionLoc, Best)) { case OR_Success: { // We found a match. Perform the conversions on the arguments and move on. ExprResult LHSRes = Self.PerformImplicitConversion(LHS.get(), Best->BuiltinTypes.ParamTypes[0], Best->Conversions[0], Sema::AA_Converting); if (LHSRes.isInvalid()) break; LHS = LHSRes; ExprResult RHSRes = Self.PerformImplicitConversion(RHS.get(), Best->BuiltinTypes.ParamTypes[1], Best->Conversions[1], Sema::AA_Converting); if (RHSRes.isInvalid()) break; RHS = RHSRes; if (Best->Function) Self.MarkFunctionReferenced(QuestionLoc, Best->Function); return false; } case OR_No_Viable_Function: // Emit a better diagnostic if one of the expressions is a null pointer // constant and the other is a pointer type. In this case, the user most // likely forgot to take the address of the other expression. if (Self.DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) return true; Self.Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) << LHS.get()->getType() << RHS.get()->getType() << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return true; case OR_Ambiguous: Self.Diag(QuestionLoc, diag::err_conditional_ambiguous_ovl) << LHS.get()->getType() << RHS.get()->getType() << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); // FIXME: Print the possible common types by printing the return types of // the viable candidates. break; case OR_Deleted: llvm_unreachable("Conditional operator has only built-in overloads"); } return true; } /// \brief Perform an "extended" implicit conversion as returned by /// TryClassUnification. static bool ConvertForConditional(Sema &Self, ExprResult &E, QualType T) { InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); InitializationKind Kind = InitializationKind::CreateCopy(E.get()->getLocStart(), SourceLocation()); Expr *Arg = E.get(); InitializationSequence InitSeq(Self, Entity, Kind, Arg); ExprResult Result = InitSeq.Perform(Self, Entity, Kind, Arg); if (Result.isInvalid()) return true; E = Result; return false; } /// \brief Check the operands of ?: under C++ semantics. /// /// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y /// extension. In this case, LHS == Cond. (But they're not aliases.) QualType Sema::CXXCheckConditionalOperands(ExprResult &Cond, ExprResult &LHS, ExprResult &RHS, ExprValueKind &VK, ExprObjectKind &OK, SourceLocation QuestionLoc) { // FIXME: Handle C99's complex types, vector types, block pointers and Obj-C++ // interface pointers. // C++11 [expr.cond]p1 // The first expression is contextually converted to bool. if (!Cond.get()->isTypeDependent()) { ExprResult CondRes = CheckCXXBooleanCondition(Cond.get()); if (CondRes.isInvalid()) return QualType(); Cond = CondRes; } // Assume r-value. VK = VK_RValue; OK = OK_Ordinary; // Either of the arguments dependent? if (LHS.get()->isTypeDependent() || RHS.get()->isTypeDependent()) return Context.DependentTy; // C++11 [expr.cond]p2 // If either the second or the third operand has type (cv) void, ... QualType LTy = LHS.get()->getType(); QualType RTy = RHS.get()->getType(); bool LVoid = LTy->isVoidType(); bool RVoid = RTy->isVoidType(); if (LVoid || RVoid) { // ... one of the following shall hold: // -- The second or the third operand (but not both) is a (possibly // parenthesized) throw-expression; the result is of the type // and value category of the other. bool LThrow = isa(LHS.get()->IgnoreParenImpCasts()); bool RThrow = isa(RHS.get()->IgnoreParenImpCasts()); if (LThrow != RThrow) { Expr *NonThrow = LThrow ? RHS.get() : LHS.get(); VK = NonThrow->getValueKind(); // DR (no number yet): the result is a bit-field if the // non-throw-expression operand is a bit-field. OK = NonThrow->getObjectKind(); return NonThrow->getType(); } // -- Both the second and third operands have type void; the result is of // type void and is a prvalue. if (LVoid && RVoid) return Context.VoidTy; // Neither holds, error. Diag(QuestionLoc, diag::err_conditional_void_nonvoid) << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1) << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return QualType(); } // Neither is void. // C++11 [expr.cond]p3 // Otherwise, if the second and third operand have different types, and // either has (cv) class type [...] an attempt is made to convert each of // those operands to the type of the other. if (!Context.hasSameType(LTy, RTy) && (LTy->isRecordType() || RTy->isRecordType())) { // These return true if a single direction is already ambiguous. QualType L2RType, R2LType; bool HaveL2R, HaveR2L; if (TryClassUnification(*this, LHS.get(), RHS.get(), QuestionLoc, HaveL2R, L2RType)) return QualType(); if (TryClassUnification(*this, RHS.get(), LHS.get(), QuestionLoc, HaveR2L, R2LType)) return QualType(); // If both can be converted, [...] the program is ill-formed. if (HaveL2R && HaveR2L) { Diag(QuestionLoc, diag::err_conditional_ambiguous) << LTy << RTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return QualType(); } // If exactly one conversion is possible, that conversion is applied to // the chosen operand and the converted operands are used in place of the // original operands for the remainder of this section. if (HaveL2R) { if (ConvertForConditional(*this, LHS, L2RType) || LHS.isInvalid()) return QualType(); LTy = LHS.get()->getType(); } else if (HaveR2L) { if (ConvertForConditional(*this, RHS, R2LType) || RHS.isInvalid()) return QualType(); RTy = RHS.get()->getType(); } } // C++11 [expr.cond]p3 // if both are glvalues of the same value category and the same type except // for cv-qualification, an attempt is made to convert each of those // operands to the type of the other. ExprValueKind LVK = LHS.get()->getValueKind(); ExprValueKind RVK = RHS.get()->getValueKind(); if (!Context.hasSameType(LTy, RTy) && Context.hasSameUnqualifiedType(LTy, RTy) && LVK == RVK && LVK != VK_RValue) { // Since the unqualified types are reference-related and we require the // result to be as if a reference bound directly, the only conversion // we can perform is to add cv-qualifiers. Qualifiers LCVR = Qualifiers::fromCVRMask(LTy.getCVRQualifiers()); Qualifiers RCVR = Qualifiers::fromCVRMask(RTy.getCVRQualifiers()); if (RCVR.isStrictSupersetOf(LCVR)) { LHS = ImpCastExprToType(LHS.get(), RTy, CK_NoOp, LVK); LTy = LHS.get()->getType(); } else if (LCVR.isStrictSupersetOf(RCVR)) { RHS = ImpCastExprToType(RHS.get(), LTy, CK_NoOp, RVK); RTy = RHS.get()->getType(); } } // C++11 [expr.cond]p4 // If the second and third operands are glvalues of the same value // category and have the same type, the result is of that type and // value category and it is a bit-field if the second or the third // operand is a bit-field, or if both are bit-fields. // We only extend this to bitfields, not to the crazy other kinds of // l-values. bool Same = Context.hasSameType(LTy, RTy); if (Same && LVK == RVK && LVK != VK_RValue && LHS.get()->isOrdinaryOrBitFieldObject() && RHS.get()->isOrdinaryOrBitFieldObject()) { VK = LHS.get()->getValueKind(); if (LHS.get()->getObjectKind() == OK_BitField || RHS.get()->getObjectKind() == OK_BitField) OK = OK_BitField; return LTy; } // C++11 [expr.cond]p5 // Otherwise, the result is a prvalue. If the second and third operands // do not have the same type, and either has (cv) class type, ... if (!Same && (LTy->isRecordType() || RTy->isRecordType())) { // ... overload resolution is used to determine the conversions (if any) // to be applied to the operands. If the overload resolution fails, the // program is ill-formed. if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc)) return QualType(); } // C++11 [expr.cond]p6 // Lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard // conversions are performed on the second and third operands. LHS = DefaultFunctionArrayLvalueConversion(LHS.get()); RHS = DefaultFunctionArrayLvalueConversion(RHS.get()); if (LHS.isInvalid() || RHS.isInvalid()) return QualType(); LTy = LHS.get()->getType(); RTy = RHS.get()->getType(); // After those conversions, one of the following shall hold: // -- The second and third operands have the same type; the result // is of that type. If the operands have class type, the result // is a prvalue temporary of the result type, which is // copy-initialized from either the second operand or the third // operand depending on the value of the first operand. if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy)) { if (LTy->isRecordType()) { // The operands have class type. Make a temporary copy. if (RequireNonAbstractType(QuestionLoc, LTy, diag::err_allocation_of_abstract_type)) return QualType(); InitializedEntity Entity = InitializedEntity::InitializeTemporary(LTy); ExprResult LHSCopy = PerformCopyInitialization(Entity, SourceLocation(), LHS); if (LHSCopy.isInvalid()) return QualType(); ExprResult RHSCopy = PerformCopyInitialization(Entity, SourceLocation(), RHS); if (RHSCopy.isInvalid()) return QualType(); LHS = LHSCopy; RHS = RHSCopy; } return LTy; } // Extension: conditional operator involving vector types. if (LTy->isVectorType() || RTy->isVectorType()) return CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false, /*AllowBothBool*/true, /*AllowBoolConversions*/false); // -- The second and third operands have arithmetic or enumeration type; // the usual arithmetic conversions are performed to bring them to a // common type, and the result is of that type. if (LTy->isArithmeticType() && RTy->isArithmeticType()) { QualType ResTy = UsualArithmeticConversions(LHS, RHS); if (LHS.isInvalid() || RHS.isInvalid()) return QualType(); if (ResTy.isNull()) { Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) << LTy << RTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return QualType(); } LHS = ImpCastExprToType(LHS.get(), ResTy, PrepareScalarCast(LHS, ResTy)); RHS = ImpCastExprToType(RHS.get(), ResTy, PrepareScalarCast(RHS, ResTy)); return ResTy; } // -- The second and third operands have pointer type, or one has pointer // type and the other is a null pointer constant, or both are null // pointer constants, at least one of which is non-integral; pointer // conversions and qualification conversions are performed to bring them // to their composite pointer type. The result is of the composite // pointer type. // -- The second and third operands have pointer to member type, or one has // pointer to member type and the other is a null pointer constant; // pointer to member conversions and qualification conversions are // performed to bring them to a common type, whose cv-qualification // shall match the cv-qualification of either the second or the third // operand. The result is of the common type. bool NonStandardCompositeType = false; QualType Composite = FindCompositePointerType(QuestionLoc, LHS, RHS, isSFINAEContext() ? nullptr : &NonStandardCompositeType); if (!Composite.isNull()) { if (NonStandardCompositeType) Diag(QuestionLoc, diag::ext_typecheck_cond_incompatible_operands_nonstandard) << LTy << RTy << Composite << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return Composite; } // Similarly, attempt to find composite type of two objective-c pointers. Composite = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc); if (!Composite.isNull()) return Composite; // Check if we are using a null with a non-pointer type. if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) return QualType(); Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) << LHS.get()->getType() << RHS.get()->getType() << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return QualType(); } /// \brief Find a merged pointer type and convert the two expressions to it. /// /// This finds the composite pointer type (or member pointer type) for @p E1 /// and @p E2 according to C++11 5.9p2. It converts both expressions to this /// type and returns it. /// It does not emit diagnostics. /// /// \param Loc The location of the operator requiring these two expressions to /// be converted to the composite pointer type. /// /// If \p NonStandardCompositeType is non-NULL, then we are permitted to find /// a non-standard (but still sane) composite type to which both expressions /// can be converted. When such a type is chosen, \c *NonStandardCompositeType /// will be set true. QualType Sema::FindCompositePointerType(SourceLocation Loc, Expr *&E1, Expr *&E2, bool *NonStandardCompositeType) { if (NonStandardCompositeType) *NonStandardCompositeType = false; assert(getLangOpts().CPlusPlus && "This function assumes C++"); QualType T1 = E1->getType(), T2 = E2->getType(); // C++11 5.9p2 // Pointer conversions and qualification conversions are performed on // pointer operands to bring them to their composite pointer type. If // one operand is a null pointer constant, the composite pointer type is // std::nullptr_t if the other operand is also a null pointer constant or, // if the other operand is a pointer, the type of the other operand. if (!T1->isAnyPointerType() && !T1->isMemberPointerType() && !T2->isAnyPointerType() && !T2->isMemberPointerType()) { if (T1->isNullPtrType() && E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { E2 = ImpCastExprToType(E2, T1, CK_NullToPointer).get(); return T1; } if (T2->isNullPtrType() && E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { E1 = ImpCastExprToType(E1, T2, CK_NullToPointer).get(); return T2; } return QualType(); } if (E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { if (T2->isMemberPointerType()) E1 = ImpCastExprToType(E1, T2, CK_NullToMemberPointer).get(); else E1 = ImpCastExprToType(E1, T2, CK_NullToPointer).get(); return T2; } if (E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { if (T1->isMemberPointerType()) E2 = ImpCastExprToType(E2, T1, CK_NullToMemberPointer).get(); else E2 = ImpCastExprToType(E2, T1, CK_NullToPointer).get(); return T1; } // Now both have to be pointers or member pointers. if ((!T1->isPointerType() && !T1->isMemberPointerType()) || (!T2->isPointerType() && !T2->isMemberPointerType())) return QualType(); // Otherwise, of one of the operands has type "pointer to cv1 void," then // the other has type "pointer to cv2 T" and the composite pointer type is // "pointer to cv12 void," where cv12 is the union of cv1 and cv2. // Otherwise, the composite pointer type is a pointer type similar to the // type of one of the operands, with a cv-qualification signature that is // the union of the cv-qualification signatures of the operand types. // In practice, the first part here is redundant; it's subsumed by the second. // What we do here is, we build the two possible composite types, and try the // conversions in both directions. If only one works, or if the two composite // types are the same, we have succeeded. // FIXME: extended qualifiers? typedef SmallVector QualifierVector; QualifierVector QualifierUnion; typedef SmallVector, 4> ContainingClassVector; ContainingClassVector MemberOfClass; QualType Composite1 = Context.getCanonicalType(T1), Composite2 = Context.getCanonicalType(T2); unsigned NeedConstBefore = 0; do { const PointerType *Ptr1, *Ptr2; if ((Ptr1 = Composite1->getAs()) && (Ptr2 = Composite2->getAs())) { Composite1 = Ptr1->getPointeeType(); Composite2 = Ptr2->getPointeeType(); // If we're allowed to create a non-standard composite type, keep track // of where we need to fill in additional 'const' qualifiers. if (NonStandardCompositeType && Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers()) NeedConstBefore = QualifierUnion.size(); QualifierUnion.push_back( Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers()); MemberOfClass.push_back(std::make_pair(nullptr, nullptr)); continue; } const MemberPointerType *MemPtr1, *MemPtr2; if ((MemPtr1 = Composite1->getAs()) && (MemPtr2 = Composite2->getAs())) { Composite1 = MemPtr1->getPointeeType(); Composite2 = MemPtr2->getPointeeType(); // If we're allowed to create a non-standard composite type, keep track // of where we need to fill in additional 'const' qualifiers. if (NonStandardCompositeType && Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers()) NeedConstBefore = QualifierUnion.size(); QualifierUnion.push_back( Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers()); MemberOfClass.push_back(std::make_pair(MemPtr1->getClass(), MemPtr2->getClass())); continue; } // FIXME: block pointer types? // Cannot unwrap any more types. break; } while (true); if (NeedConstBefore && NonStandardCompositeType) { // Extension: Add 'const' to qualifiers that come before the first qualifier // mismatch, so that our (non-standard!) composite type meets the // requirements of C++ [conv.qual]p4 bullet 3. for (unsigned I = 0; I != NeedConstBefore; ++I) { if ((QualifierUnion[I] & Qualifiers::Const) == 0) { QualifierUnion[I] = QualifierUnion[I] | Qualifiers::Const; *NonStandardCompositeType = true; } } } // Rewrap the composites as pointers or member pointers with the union CVRs. ContainingClassVector::reverse_iterator MOC = MemberOfClass.rbegin(); for (QualifierVector::reverse_iterator I = QualifierUnion.rbegin(), E = QualifierUnion.rend(); I != E; (void)++I, ++MOC) { Qualifiers Quals = Qualifiers::fromCVRMask(*I); if (MOC->first && MOC->second) { // Rebuild member pointer type Composite1 = Context.getMemberPointerType( Context.getQualifiedType(Composite1, Quals), MOC->first); Composite2 = Context.getMemberPointerType( Context.getQualifiedType(Composite2, Quals), MOC->second); } else { // Rebuild pointer type Composite1 = Context.getPointerType(Context.getQualifiedType(Composite1, Quals)); Composite2 = Context.getPointerType(Context.getQualifiedType(Composite2, Quals)); } } // Try to convert to the first composite pointer type. InitializedEntity Entity1 = InitializedEntity::InitializeTemporary(Composite1); InitializationKind Kind = InitializationKind::CreateCopy(Loc, SourceLocation()); InitializationSequence E1ToC1(*this, Entity1, Kind, E1); InitializationSequence E2ToC1(*this, Entity1, Kind, E2); if (E1ToC1 && E2ToC1) { // Conversion to Composite1 is viable. if (!Context.hasSameType(Composite1, Composite2)) { // Composite2 is a different type from Composite1. Check whether // Composite2 is also viable. InitializedEntity Entity2 = InitializedEntity::InitializeTemporary(Composite2); InitializationSequence E1ToC2(*this, Entity2, Kind, E1); InitializationSequence E2ToC2(*this, Entity2, Kind, E2); if (E1ToC2 && E2ToC2) { // Both Composite1 and Composite2 are viable and are different; // this is an ambiguity. return QualType(); } } // Convert E1 to Composite1 ExprResult E1Result = E1ToC1.Perform(*this, Entity1, Kind, E1); if (E1Result.isInvalid()) return QualType(); E1 = E1Result.getAs(); // Convert E2 to Composite1 ExprResult E2Result = E2ToC1.Perform(*this, Entity1, Kind, E2); if (E2Result.isInvalid()) return QualType(); E2 = E2Result.getAs(); return Composite1; } // Check whether Composite2 is viable. InitializedEntity Entity2 = InitializedEntity::InitializeTemporary(Composite2); InitializationSequence E1ToC2(*this, Entity2, Kind, E1); InitializationSequence E2ToC2(*this, Entity2, Kind, E2); if (!E1ToC2 || !E2ToC2) return QualType(); // Convert E1 to Composite2 ExprResult E1Result = E1ToC2.Perform(*this, Entity2, Kind, E1); if (E1Result.isInvalid()) return QualType(); E1 = E1Result.getAs(); // Convert E2 to Composite2 ExprResult E2Result = E2ToC2.Perform(*this, Entity2, Kind, E2); if (E2Result.isInvalid()) return QualType(); E2 = E2Result.getAs(); return Composite2; } ExprResult Sema::MaybeBindToTemporary(Expr *E) { if (!E) return ExprError(); assert(!isa(E) && "Double-bound temporary?"); // If the result is a glvalue, we shouldn't bind it. if (!E->isRValue()) return E; // In ARC, calls that return a retainable type can return retained, // in which case we have to insert a consuming cast. if (getLangOpts().ObjCAutoRefCount && E->getType()->isObjCRetainableType()) { bool ReturnsRetained; // For actual calls, we compute this by examining the type of the // called value. if (CallExpr *Call = dyn_cast(E)) { Expr *Callee = Call->getCallee()->IgnoreParens(); QualType T = Callee->getType(); if (T == Context.BoundMemberTy) { // Handle pointer-to-members. if (BinaryOperator *BinOp = dyn_cast(Callee)) T = BinOp->getRHS()->getType(); else if (MemberExpr *Mem = dyn_cast(Callee)) T = Mem->getMemberDecl()->getType(); } if (const PointerType *Ptr = T->getAs()) T = Ptr->getPointeeType(); else if (const BlockPointerType *Ptr = T->getAs()) T = Ptr->getPointeeType(); else if (const MemberPointerType *MemPtr = T->getAs()) T = MemPtr->getPointeeType(); const FunctionType *FTy = T->getAs(); assert(FTy && "call to value not of function type?"); ReturnsRetained = FTy->getExtInfo().getProducesResult(); // ActOnStmtExpr arranges things so that StmtExprs of retainable // type always produce a +1 object. } else if (isa(E)) { ReturnsRetained = true; // We hit this case with the lambda conversion-to-block optimization; // we don't want any extra casts here. } else if (isa(E) && isa(cast(E)->getSubExpr())) { return E; // For message sends and property references, we try to find an // actual method. FIXME: we should infer retention by selector in // cases where we don't have an actual method. } else { ObjCMethodDecl *D = nullptr; if (ObjCMessageExpr *Send = dyn_cast(E)) { D = Send->getMethodDecl(); } else if (ObjCBoxedExpr *BoxedExpr = dyn_cast(E)) { D = BoxedExpr->getBoxingMethod(); } else if (ObjCArrayLiteral *ArrayLit = dyn_cast(E)) { D = ArrayLit->getArrayWithObjectsMethod(); } else if (ObjCDictionaryLiteral *DictLit = dyn_cast(E)) { D = DictLit->getDictWithObjectsMethod(); } ReturnsRetained = (D && D->hasAttr()); // Don't do reclaims on performSelector calls; despite their // return type, the invoked method doesn't necessarily actually // return an object. if (!ReturnsRetained && D && D->getMethodFamily() == OMF_performSelector) return E; } // Don't reclaim an object of Class type. if (!ReturnsRetained && E->getType()->isObjCARCImplicitlyUnretainedType()) return E; Cleanup.setExprNeedsCleanups(true); CastKind ck = (ReturnsRetained ? CK_ARCConsumeObject : CK_ARCReclaimReturnedObject); return ImplicitCastExpr::Create(Context, E->getType(), ck, E, nullptr, VK_RValue); } if (!getLangOpts().CPlusPlus) return E; // Search for the base element type (cf. ASTContext::getBaseElementType) with // a fast path for the common case that the type is directly a RecordType. const Type *T = Context.getCanonicalType(E->getType().getTypePtr()); const RecordType *RT = nullptr; while (!RT) { switch (T->getTypeClass()) { case Type::Record: RT = cast(T); break; case Type::ConstantArray: case Type::IncompleteArray: case Type::VariableArray: case Type::DependentSizedArray: T = cast(T)->getElementType().getTypePtr(); break; default: return E; } } // That should be enough to guarantee that this type is complete, if we're // not processing a decltype expression. CXXRecordDecl *RD = cast(RT->getDecl()); if (RD->isInvalidDecl() || RD->isDependentContext()) return E; bool IsDecltype = ExprEvalContexts.back().IsDecltype; CXXDestructorDecl *Destructor = IsDecltype ? nullptr : LookupDestructor(RD); if (Destructor) { MarkFunctionReferenced(E->getExprLoc(), Destructor); CheckDestructorAccess(E->getExprLoc(), Destructor, PDiag(diag::err_access_dtor_temp) << E->getType()); if (DiagnoseUseOfDecl(Destructor, E->getExprLoc())) return ExprError(); // If destructor is trivial, we can avoid the extra copy. if (Destructor->isTrivial()) return E; // We need a cleanup, but we don't need to remember the temporary. Cleanup.setExprNeedsCleanups(true); } CXXTemporary *Temp = CXXTemporary::Create(Context, Destructor); CXXBindTemporaryExpr *Bind = CXXBindTemporaryExpr::Create(Context, Temp, E); if (IsDecltype) ExprEvalContexts.back().DelayedDecltypeBinds.push_back(Bind); return Bind; } ExprResult Sema::MaybeCreateExprWithCleanups(ExprResult SubExpr) { if (SubExpr.isInvalid()) return ExprError(); return MaybeCreateExprWithCleanups(SubExpr.get()); } Expr *Sema::MaybeCreateExprWithCleanups(Expr *SubExpr) { assert(SubExpr && "subexpression can't be null!"); CleanupVarDeclMarking(); unsigned FirstCleanup = ExprEvalContexts.back().NumCleanupObjects; assert(ExprCleanupObjects.size() >= FirstCleanup); assert(Cleanup.exprNeedsCleanups() || ExprCleanupObjects.size() == FirstCleanup); if (!Cleanup.exprNeedsCleanups()) return SubExpr; auto Cleanups = llvm::makeArrayRef(ExprCleanupObjects.begin() + FirstCleanup, ExprCleanupObjects.size() - FirstCleanup); auto *E = ExprWithCleanups::Create( Context, SubExpr, Cleanup.cleanupsHaveSideEffects(), Cleanups); DiscardCleanupsInEvaluationContext(); return E; } Stmt *Sema::MaybeCreateStmtWithCleanups(Stmt *SubStmt) { assert(SubStmt && "sub-statement can't be null!"); CleanupVarDeclMarking(); if (!Cleanup.exprNeedsCleanups()) return SubStmt; // FIXME: In order to attach the temporaries, wrap the statement into // a StmtExpr; currently this is only used for asm statements. // This is hacky, either create a new CXXStmtWithTemporaries statement or // a new AsmStmtWithTemporaries. CompoundStmt *CompStmt = new (Context) CompoundStmt(Context, SubStmt, SourceLocation(), SourceLocation()); Expr *E = new (Context) StmtExpr(CompStmt, Context.VoidTy, SourceLocation(), SourceLocation()); return MaybeCreateExprWithCleanups(E); } /// Process the expression contained within a decltype. For such expressions, /// certain semantic checks on temporaries are delayed until this point, and /// are omitted for the 'topmost' call in the decltype expression. If the /// topmost call bound a temporary, strip that temporary off the expression. ExprResult Sema::ActOnDecltypeExpression(Expr *E) { assert(ExprEvalContexts.back().IsDecltype && "not in a decltype expression"); // C++11 [expr.call]p11: // If a function call is a prvalue of object type, // -- if the function call is either // -- the operand of a decltype-specifier, or // -- the right operand of a comma operator that is the operand of a // decltype-specifier, // a temporary object is not introduced for the prvalue. // Recursively rebuild ParenExprs and comma expressions to strip out the // outermost CXXBindTemporaryExpr, if any. if (ParenExpr *PE = dyn_cast(E)) { ExprResult SubExpr = ActOnDecltypeExpression(PE->getSubExpr()); if (SubExpr.isInvalid()) return ExprError(); if (SubExpr.get() == PE->getSubExpr()) return E; return ActOnParenExpr(PE->getLParen(), PE->getRParen(), SubExpr.get()); } if (BinaryOperator *BO = dyn_cast(E)) { if (BO->getOpcode() == BO_Comma) { ExprResult RHS = ActOnDecltypeExpression(BO->getRHS()); if (RHS.isInvalid()) return ExprError(); if (RHS.get() == BO->getRHS()) return E; return new (Context) BinaryOperator( BO->getLHS(), RHS.get(), BO_Comma, BO->getType(), BO->getValueKind(), BO->getObjectKind(), BO->getOperatorLoc(), BO->isFPContractable()); } } CXXBindTemporaryExpr *TopBind = dyn_cast(E); CallExpr *TopCall = TopBind ? dyn_cast(TopBind->getSubExpr()) : nullptr; if (TopCall) E = TopCall; else TopBind = nullptr; // Disable the special decltype handling now. ExprEvalContexts.back().IsDecltype = false; // In MS mode, don't perform any extra checking of call return types within a // decltype expression. if (getLangOpts().MSVCCompat) return E; // Perform the semantic checks we delayed until this point. for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeCalls.size(); I != N; ++I) { CallExpr *Call = ExprEvalContexts.back().DelayedDecltypeCalls[I]; if (Call == TopCall) continue; if (CheckCallReturnType(Call->getCallReturnType(Context), Call->getLocStart(), Call, Call->getDirectCallee())) return ExprError(); } // Now all relevant types are complete, check the destructors are accessible // and non-deleted, and annotate them on the temporaries. for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeBinds.size(); I != N; ++I) { CXXBindTemporaryExpr *Bind = ExprEvalContexts.back().DelayedDecltypeBinds[I]; if (Bind == TopBind) continue; CXXTemporary *Temp = Bind->getTemporary(); CXXRecordDecl *RD = Bind->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); CXXDestructorDecl *Destructor = LookupDestructor(RD); Temp->setDestructor(Destructor); MarkFunctionReferenced(Bind->getExprLoc(), Destructor); CheckDestructorAccess(Bind->getExprLoc(), Destructor, PDiag(diag::err_access_dtor_temp) << Bind->getType()); if (DiagnoseUseOfDecl(Destructor, Bind->getExprLoc())) return ExprError(); // We need a cleanup, but we don't need to remember the temporary. Cleanup.setExprNeedsCleanups(true); } // Possibly strip off the top CXXBindTemporaryExpr. return E; } /// Note a set of 'operator->' functions that were used for a member access. static void noteOperatorArrows(Sema &S, ArrayRef OperatorArrows) { unsigned SkipStart = OperatorArrows.size(), SkipCount = 0; // FIXME: Make this configurable? unsigned Limit = 9; if (OperatorArrows.size() > Limit) { // Produce Limit-1 normal notes and one 'skipping' note. SkipStart = (Limit - 1) / 2 + (Limit - 1) % 2; SkipCount = OperatorArrows.size() - (Limit - 1); } for (unsigned I = 0; I < OperatorArrows.size(); /**/) { if (I == SkipStart) { S.Diag(OperatorArrows[I]->getLocation(), diag::note_operator_arrows_suppressed) << SkipCount; I += SkipCount; } else { S.Diag(OperatorArrows[I]->getLocation(), diag::note_operator_arrow_here) << OperatorArrows[I]->getCallResultType(); ++I; } } } ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base, SourceLocation OpLoc, tok::TokenKind OpKind, ParsedType &ObjectType, bool &MayBePseudoDestructor) { // Since this might be a postfix expression, get rid of ParenListExprs. ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); if (Result.isInvalid()) return ExprError(); Base = Result.get(); Result = CheckPlaceholderExpr(Base); if (Result.isInvalid()) return ExprError(); Base = Result.get(); QualType BaseType = Base->getType(); MayBePseudoDestructor = false; if (BaseType->isDependentType()) { // If we have a pointer to a dependent type and are using the -> operator, // the object type is the type that the pointer points to. We might still // have enough information about that type to do something useful. if (OpKind == tok::arrow) if (const PointerType *Ptr = BaseType->getAs()) BaseType = Ptr->getPointeeType(); ObjectType = ParsedType::make(BaseType); MayBePseudoDestructor = true; return Base; } // C++ [over.match.oper]p8: // [...] When operator->returns, the operator-> is applied to the value // returned, with the original second operand. if (OpKind == tok::arrow) { QualType StartingType = BaseType; bool NoArrowOperatorFound = false; bool FirstIteration = true; FunctionDecl *CurFD = dyn_cast(CurContext); // The set of types we've considered so far. llvm::SmallPtrSet CTypes; SmallVector OperatorArrows; CTypes.insert(Context.getCanonicalType(BaseType)); while (BaseType->isRecordType()) { if (OperatorArrows.size() >= getLangOpts().ArrowDepth) { Diag(OpLoc, diag::err_operator_arrow_depth_exceeded) << StartingType << getLangOpts().ArrowDepth << Base->getSourceRange(); noteOperatorArrows(*this, OperatorArrows); Diag(OpLoc, diag::note_operator_arrow_depth) << getLangOpts().ArrowDepth; return ExprError(); } Result = BuildOverloadedArrowExpr( S, Base, OpLoc, // When in a template specialization and on the first loop iteration, // potentially give the default diagnostic (with the fixit in a // separate note) instead of having the error reported back to here // and giving a diagnostic with a fixit attached to the error itself. (FirstIteration && CurFD && CurFD->isFunctionTemplateSpecialization()) ? nullptr : &NoArrowOperatorFound); if (Result.isInvalid()) { if (NoArrowOperatorFound) { if (FirstIteration) { Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) << BaseType << 1 << Base->getSourceRange() << FixItHint::CreateReplacement(OpLoc, "."); OpKind = tok::period; break; } Diag(OpLoc, diag::err_typecheck_member_reference_arrow) << BaseType << Base->getSourceRange(); CallExpr *CE = dyn_cast(Base); if (Decl *CD = (CE ? CE->getCalleeDecl() : nullptr)) { Diag(CD->getLocStart(), diag::note_member_reference_arrow_from_operator_arrow); } } return ExprError(); } Base = Result.get(); if (CXXOperatorCallExpr *OpCall = dyn_cast(Base)) OperatorArrows.push_back(OpCall->getDirectCallee()); BaseType = Base->getType(); CanQualType CBaseType = Context.getCanonicalType(BaseType); if (!CTypes.insert(CBaseType).second) { Diag(OpLoc, diag::err_operator_arrow_circular) << StartingType; noteOperatorArrows(*this, OperatorArrows); return ExprError(); } FirstIteration = false; } if (OpKind == tok::arrow && (BaseType->isPointerType() || BaseType->isObjCObjectPointerType())) BaseType = BaseType->getPointeeType(); } // Objective-C properties allow "." access on Objective-C pointer types, // so adjust the base type to the object type itself. if (BaseType->isObjCObjectPointerType()) BaseType = BaseType->getPointeeType(); // C++ [basic.lookup.classref]p2: // [...] If the type of the object expression is of pointer to scalar // type, the unqualified-id is looked up in the context of the complete // postfix-expression. // // This also indicates that we could be parsing a pseudo-destructor-name. // Note that Objective-C class and object types can be pseudo-destructor // expressions or normal member (ivar or property) access expressions, and // it's legal for the type to be incomplete if this is a pseudo-destructor // call. We'll do more incomplete-type checks later in the lookup process, // so just skip this check for ObjC types. if (BaseType->isObjCObjectOrInterfaceType()) { ObjectType = ParsedType::make(BaseType); MayBePseudoDestructor = true; return Base; } else if (!BaseType->isRecordType()) { ObjectType = nullptr; MayBePseudoDestructor = true; return Base; } // The object type must be complete (or dependent), or // C++11 [expr.prim.general]p3: // Unlike the object expression in other contexts, *this is not required to // be of complete type for purposes of class member access (5.2.5) outside // the member function body. if (!BaseType->isDependentType() && !isThisOutsideMemberFunctionBody(BaseType) && RequireCompleteType(OpLoc, BaseType, diag::err_incomplete_member_access)) return ExprError(); // C++ [basic.lookup.classref]p2: // If the id-expression in a class member access (5.2.5) is an // unqualified-id, and the type of the object expression is of a class // type C (or of pointer to a class type C), the unqualified-id is looked // up in the scope of class C. [...] ObjectType = ParsedType::make(BaseType); return Base; } static bool CheckArrow(Sema& S, QualType& ObjectType, Expr *&Base, tok::TokenKind& OpKind, SourceLocation OpLoc) { if (Base->hasPlaceholderType()) { ExprResult result = S.CheckPlaceholderExpr(Base); if (result.isInvalid()) return true; Base = result.get(); } ObjectType = Base->getType(); // C++ [expr.pseudo]p2: // The left-hand side of the dot operator shall be of scalar type. The // left-hand side of the arrow operator shall be of pointer to scalar type. // This scalar type is the object type. // Note that this is rather different from the normal handling for the // arrow operator. if (OpKind == tok::arrow) { if (const PointerType *Ptr = ObjectType->getAs()) { ObjectType = Ptr->getPointeeType(); } else if (!Base->isTypeDependent()) { // The user wrote "p->" when they probably meant "p."; fix it. S.Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) << ObjectType << true << FixItHint::CreateReplacement(OpLoc, "."); if (S.isSFINAEContext()) return true; OpKind = tok::period; } } return false; } ExprResult Sema::BuildPseudoDestructorExpr(Expr *Base, SourceLocation OpLoc, tok::TokenKind OpKind, const CXXScopeSpec &SS, TypeSourceInfo *ScopeTypeInfo, SourceLocation CCLoc, SourceLocation TildeLoc, PseudoDestructorTypeStorage Destructed) { TypeSourceInfo *DestructedTypeInfo = Destructed.getTypeSourceInfo(); QualType ObjectType; if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) return ExprError(); if (!ObjectType->isDependentType() && !ObjectType->isScalarType() && !ObjectType->isVectorType()) { if (getLangOpts().MSVCCompat && ObjectType->isVoidType()) Diag(OpLoc, diag::ext_pseudo_dtor_on_void) << Base->getSourceRange(); else { Diag(OpLoc, diag::err_pseudo_dtor_base_not_scalar) << ObjectType << Base->getSourceRange(); return ExprError(); } } // C++ [expr.pseudo]p2: // [...] The cv-unqualified versions of the object type and of the type // designated by the pseudo-destructor-name shall be the same type. if (DestructedTypeInfo) { QualType DestructedType = DestructedTypeInfo->getType(); SourceLocation DestructedTypeStart = DestructedTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(); if (!DestructedType->isDependentType() && !ObjectType->isDependentType()) { if (!Context.hasSameUnqualifiedType(DestructedType, ObjectType)) { Diag(DestructedTypeStart, diag::err_pseudo_dtor_type_mismatch) << ObjectType << DestructedType << Base->getSourceRange() << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); // Recover by setting the destructed type to the object type. DestructedType = ObjectType; DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType, DestructedTypeStart); Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); } else if (DestructedType.getObjCLifetime() != ObjectType.getObjCLifetime()) { if (DestructedType.getObjCLifetime() == Qualifiers::OCL_None) { // Okay: just pretend that the user provided the correctly-qualified // type. } else { Diag(DestructedTypeStart, diag::err_arc_pseudo_dtor_inconstant_quals) << ObjectType << DestructedType << Base->getSourceRange() << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); } // Recover by setting the destructed type to the object type. DestructedType = ObjectType; DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType, DestructedTypeStart); Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); } } } // C++ [expr.pseudo]p2: // [...] Furthermore, the two type-names in a pseudo-destructor-name of the // form // // ::[opt] nested-name-specifier[opt] type-name :: ~ type-name // // shall designate the same scalar type. if (ScopeTypeInfo) { QualType ScopeType = ScopeTypeInfo->getType(); if (!ScopeType->isDependentType() && !ObjectType->isDependentType() && !Context.hasSameUnqualifiedType(ScopeType, ObjectType)) { Diag(ScopeTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(), diag::err_pseudo_dtor_type_mismatch) << ObjectType << ScopeType << Base->getSourceRange() << ScopeTypeInfo->getTypeLoc().getLocalSourceRange(); ScopeType = QualType(); ScopeTypeInfo = nullptr; } } Expr *Result = new (Context) CXXPseudoDestructorExpr(Context, Base, OpKind == tok::arrow, OpLoc, SS.getWithLocInContext(Context), ScopeTypeInfo, CCLoc, TildeLoc, Destructed); return Result; } ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, SourceLocation OpLoc, tok::TokenKind OpKind, CXXScopeSpec &SS, UnqualifiedId &FirstTypeName, SourceLocation CCLoc, SourceLocation TildeLoc, UnqualifiedId &SecondTypeName) { assert((FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId || FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) && "Invalid first type name in pseudo-destructor"); assert((SecondTypeName.getKind() == UnqualifiedId::IK_TemplateId || SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) && "Invalid second type name in pseudo-destructor"); QualType ObjectType; if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) return ExprError(); // Compute the object type that we should use for name lookup purposes. Only // record types and dependent types matter. ParsedType ObjectTypePtrForLookup; if (!SS.isSet()) { if (ObjectType->isRecordType()) ObjectTypePtrForLookup = ParsedType::make(ObjectType); else if (ObjectType->isDependentType()) ObjectTypePtrForLookup = ParsedType::make(Context.DependentTy); } // Convert the name of the type being destructed (following the ~) into a // type (with source-location information). QualType DestructedType; TypeSourceInfo *DestructedTypeInfo = nullptr; PseudoDestructorTypeStorage Destructed; if (SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) { ParsedType T = getTypeName(*SecondTypeName.Identifier, SecondTypeName.StartLocation, S, &SS, true, false, ObjectTypePtrForLookup); if (!T && ((SS.isSet() && !computeDeclContext(SS, false)) || (!SS.isSet() && ObjectType->isDependentType()))) { // The name of the type being destroyed is a dependent name, and we // couldn't find anything useful in scope. Just store the identifier and // it's location, and we'll perform (qualified) name lookup again at // template instantiation time. Destructed = PseudoDestructorTypeStorage(SecondTypeName.Identifier, SecondTypeName.StartLocation); } else if (!T) { Diag(SecondTypeName.StartLocation, diag::err_pseudo_dtor_destructor_non_type) << SecondTypeName.Identifier << ObjectType; if (isSFINAEContext()) return ExprError(); // Recover by assuming we had the right type all along. DestructedType = ObjectType; } else DestructedType = GetTypeFromParser(T, &DestructedTypeInfo); } else { // Resolve the template-id to a type. TemplateIdAnnotation *TemplateId = SecondTypeName.TemplateId; ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(), TemplateId->NumArgs); TypeResult T = ActOnTemplateIdType(TemplateId->SS, TemplateId->TemplateKWLoc, TemplateId->Template, TemplateId->TemplateNameLoc, TemplateId->LAngleLoc, TemplateArgsPtr, TemplateId->RAngleLoc); if (T.isInvalid() || !T.get()) { // Recover by assuming we had the right type all along. DestructedType = ObjectType; } else DestructedType = GetTypeFromParser(T.get(), &DestructedTypeInfo); } // If we've performed some kind of recovery, (re-)build the type source // information. if (!DestructedType.isNull()) { if (!DestructedTypeInfo) DestructedTypeInfo = Context.getTrivialTypeSourceInfo(DestructedType, SecondTypeName.StartLocation); Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); } // Convert the name of the scope type (the type prior to '::') into a type. TypeSourceInfo *ScopeTypeInfo = nullptr; QualType ScopeType; if (FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId || FirstTypeName.Identifier) { if (FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) { ParsedType T = getTypeName(*FirstTypeName.Identifier, FirstTypeName.StartLocation, S, &SS, true, false, ObjectTypePtrForLookup); if (!T) { Diag(FirstTypeName.StartLocation, diag::err_pseudo_dtor_destructor_non_type) << FirstTypeName.Identifier << ObjectType; if (isSFINAEContext()) return ExprError(); // Just drop this type. It's unnecessary anyway. ScopeType = QualType(); } else ScopeType = GetTypeFromParser(T, &ScopeTypeInfo); } else { // Resolve the template-id to a type. TemplateIdAnnotation *TemplateId = FirstTypeName.TemplateId; ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(), TemplateId->NumArgs); TypeResult T = ActOnTemplateIdType(TemplateId->SS, TemplateId->TemplateKWLoc, TemplateId->Template, TemplateId->TemplateNameLoc, TemplateId->LAngleLoc, TemplateArgsPtr, TemplateId->RAngleLoc); if (T.isInvalid() || !T.get()) { // Recover by dropping this type. ScopeType = QualType(); } else ScopeType = GetTypeFromParser(T.get(), &ScopeTypeInfo); } } if (!ScopeType.isNull() && !ScopeTypeInfo) ScopeTypeInfo = Context.getTrivialTypeSourceInfo(ScopeType, FirstTypeName.StartLocation); return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, SS, ScopeTypeInfo, CCLoc, TildeLoc, Destructed); } ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, SourceLocation OpLoc, tok::TokenKind OpKind, SourceLocation TildeLoc, const DeclSpec& DS) { QualType ObjectType; if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) return ExprError(); QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc(), false); TypeLocBuilder TLB; DecltypeTypeLoc DecltypeTL = TLB.push(T); DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc()); TypeSourceInfo *DestructedTypeInfo = TLB.getTypeSourceInfo(Context, T); PseudoDestructorTypeStorage Destructed(DestructedTypeInfo); return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, CXXScopeSpec(), nullptr, SourceLocation(), TildeLoc, Destructed); } ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl, CXXConversionDecl *Method, bool HadMultipleCandidates) { if (Method->getParent()->isLambda() && Method->getConversionType()->isBlockPointerType()) { // This is a lambda coversion to block pointer; check if the argument // is a LambdaExpr. Expr *SubE = E; CastExpr *CE = dyn_cast(SubE); if (CE && CE->getCastKind() == CK_NoOp) SubE = CE->getSubExpr(); SubE = SubE->IgnoreParens(); if (CXXBindTemporaryExpr *BE = dyn_cast(SubE)) SubE = BE->getSubExpr(); if (isa(SubE)) { // For the conversion to block pointer on a lambda expression, we // construct a special BlockLiteral instead; this doesn't really make // a difference in ARC, but outside of ARC the resulting block literal // follows the normal lifetime rules for block literals instead of being // autoreleased. DiagnosticErrorTrap Trap(Diags); PushExpressionEvaluationContext(PotentiallyEvaluated); ExprResult Exp = BuildBlockForLambdaConversion(E->getExprLoc(), E->getExprLoc(), Method, E); PopExpressionEvaluationContext(); if (Exp.isInvalid()) Diag(E->getExprLoc(), diag::note_lambda_to_block_conv); return Exp; } } ExprResult Exp = PerformObjectArgumentInitialization(E, /*Qualifier=*/nullptr, FoundDecl, Method); if (Exp.isInvalid()) return true; MemberExpr *ME = new (Context) MemberExpr( Exp.get(), /*IsArrow=*/false, SourceLocation(), Method, SourceLocation(), Context.BoundMemberTy, VK_RValue, OK_Ordinary); if (HadMultipleCandidates) ME->setHadMultipleCandidates(true); MarkMemberReferenced(ME); QualType ResultType = Method->getReturnType(); ExprValueKind VK = Expr::getValueKindForType(ResultType); ResultType = ResultType.getNonLValueExprType(Context); CXXMemberCallExpr *CE = new (Context) CXXMemberCallExpr(Context, ME, None, ResultType, VK, Exp.get()->getLocEnd()); return CE; } ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand, SourceLocation RParen) { // If the operand is an unresolved lookup expression, the expression is ill- // formed per [over.over]p1, because overloaded function names cannot be used // without arguments except in explicit contexts. ExprResult R = CheckPlaceholderExpr(Operand); if (R.isInvalid()) return R; // The operand may have been modified when checking the placeholder type. Operand = R.get(); if (ActiveTemplateInstantiations.empty() && Operand->HasSideEffects(Context, false)) { // The expression operand for noexcept is in an unevaluated expression // context, so side effects could result in unintended consequences. Diag(Operand->getExprLoc(), diag::warn_side_effects_unevaluated_context); } CanThrowResult CanThrow = canThrow(Operand); return new (Context) CXXNoexceptExpr(Context.BoolTy, Operand, CanThrow, KeyLoc, RParen); } ExprResult Sema::ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation, Expr *Operand, SourceLocation RParen) { return BuildCXXNoexceptExpr(KeyLoc, Operand, RParen); } static bool IsSpecialDiscardedValue(Expr *E) { // In C++11, discarded-value expressions of a certain form are special, // according to [expr]p10: // The lvalue-to-rvalue conversion (4.1) is applied only if the // expression is an lvalue of volatile-qualified type and it has // one of the following forms: E = E->IgnoreParens(); // - id-expression (5.1.1), if (isa(E)) return true; // - subscripting (5.2.1), if (isa(E)) return true; // - class member access (5.2.5), if (isa(E)) return true; // - indirection (5.3.1), if (UnaryOperator *UO = dyn_cast(E)) if (UO->getOpcode() == UO_Deref) return true; if (BinaryOperator *BO = dyn_cast(E)) { // - pointer-to-member operation (5.5), if (BO->isPtrMemOp()) return true; // - comma expression (5.18) where the right operand is one of the above. if (BO->getOpcode() == BO_Comma) return IsSpecialDiscardedValue(BO->getRHS()); } // - conditional expression (5.16) where both the second and the third // operands are one of the above, or if (ConditionalOperator *CO = dyn_cast(E)) return IsSpecialDiscardedValue(CO->getTrueExpr()) && IsSpecialDiscardedValue(CO->getFalseExpr()); // The related edge case of "*x ?: *x". if (BinaryConditionalOperator *BCO = dyn_cast(E)) { if (OpaqueValueExpr *OVE = dyn_cast(BCO->getTrueExpr())) return IsSpecialDiscardedValue(OVE->getSourceExpr()) && IsSpecialDiscardedValue(BCO->getFalseExpr()); } // Objective-C++ extensions to the rule. if (isa(E) || isa(E)) return true; return false; } /// Perform the conversions required for an expression used in a /// context that ignores the result. ExprResult Sema::IgnoredValueConversions(Expr *E) { if (E->hasPlaceholderType()) { ExprResult result = CheckPlaceholderExpr(E); if (result.isInvalid()) return E; E = result.get(); } // C99 6.3.2.1: // [Except in specific positions,] an lvalue that does not have // array type is converted to the value stored in the // designated object (and is no longer an lvalue). if (E->isRValue()) { // In C, function designators (i.e. expressions of function type) // are r-values, but we still want to do function-to-pointer decay // on them. This is both technically correct and convenient for // some clients. if (!getLangOpts().CPlusPlus && E->getType()->isFunctionType()) return DefaultFunctionArrayConversion(E); return E; } if (getLangOpts().CPlusPlus) { // The C++11 standard defines the notion of a discarded-value expression; // normally, we don't need to do anything to handle it, but if it is a // volatile lvalue with a special form, we perform an lvalue-to-rvalue // conversion. if (getLangOpts().CPlusPlus11 && E->isGLValue() && E->getType().isVolatileQualified() && IsSpecialDiscardedValue(E)) { ExprResult Res = DefaultLvalueConversion(E); if (Res.isInvalid()) return E; E = Res.get(); } return E; } // GCC seems to also exclude expressions of incomplete enum type. if (const EnumType *T = E->getType()->getAs()) { if (!T->getDecl()->isComplete()) { // FIXME: stupid workaround for a codegen bug! E = ImpCastExprToType(E, Context.VoidTy, CK_ToVoid).get(); return E; } } ExprResult Res = DefaultFunctionArrayLvalueConversion(E); if (Res.isInvalid()) return E; E = Res.get(); if (!E->getType()->isVoidType()) RequireCompleteType(E->getExprLoc(), E->getType(), diag::err_incomplete_type); return E; } // If we can unambiguously determine whether Var can never be used // in a constant expression, return true. // - if the variable and its initializer are non-dependent, then // we can unambiguously check if the variable is a constant expression. // - if the initializer is not value dependent - we can determine whether // it can be used to initialize a constant expression. If Init can not // be used to initialize a constant expression we conclude that Var can // never be a constant expression. // - FXIME: if the initializer is dependent, we can still do some analysis and // identify certain cases unambiguously as non-const by using a Visitor: // - such as those that involve odr-use of a ParmVarDecl, involve a new // delete, lambda-expr, dynamic-cast, reinterpret-cast etc... static inline bool VariableCanNeverBeAConstantExpression(VarDecl *Var, ASTContext &Context) { if (isa(Var)) return true; const VarDecl *DefVD = nullptr; // If there is no initializer - this can not be a constant expression. if (!Var->getAnyInitializer(DefVD)) return true; assert(DefVD); if (DefVD->isWeak()) return false; EvaluatedStmt *Eval = DefVD->ensureEvaluatedStmt(); Expr *Init = cast(Eval->Value); if (Var->getType()->isDependentType() || Init->isValueDependent()) { // FIXME: Teach the constant evaluator to deal with the non-dependent parts // of value-dependent expressions, and use it here to determine whether the // initializer is a potential constant expression. return false; } return !IsVariableAConstantExpression(Var, Context); } /// \brief Check if the current lambda has any potential captures /// that must be captured by any of its enclosing lambdas that are ready to /// capture. If there is a lambda that can capture a nested /// potential-capture, go ahead and do so. Also, check to see if any /// variables are uncaptureable or do not involve an odr-use so do not /// need to be captured. static void CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures( Expr *const FE, LambdaScopeInfo *const CurrentLSI, Sema &S) { assert(!S.isUnevaluatedContext()); assert(S.CurContext->isDependentContext()); assert(CurrentLSI->CallOperator == S.CurContext && "The current call operator must be synchronized with Sema's CurContext"); const bool IsFullExprInstantiationDependent = FE->isInstantiationDependent(); ArrayRef FunctionScopesArrayRef( S.FunctionScopes.data(), S.FunctionScopes.size()); // All the potentially captureable variables in the current nested // lambda (within a generic outer lambda), must be captured by an // outer lambda that is enclosed within a non-dependent context. const unsigned NumPotentialCaptures = CurrentLSI->getNumPotentialVariableCaptures(); for (unsigned I = 0; I != NumPotentialCaptures; ++I) { Expr *VarExpr = nullptr; VarDecl *Var = nullptr; CurrentLSI->getPotentialVariableCapture(I, Var, VarExpr); // If the variable is clearly identified as non-odr-used and the full // expression is not instantiation dependent, only then do we not // need to check enclosing lambda's for speculative captures. // For e.g.: // Even though 'x' is not odr-used, it should be captured. // int test() { // const int x = 10; // auto L = [=](auto a) { // (void) +x + a; // }; // } if (CurrentLSI->isVariableExprMarkedAsNonODRUsed(VarExpr) && !IsFullExprInstantiationDependent) continue; // If we have a capture-capable lambda for the variable, go ahead and // capture the variable in that lambda (and all its enclosing lambdas). if (const Optional Index = getStackIndexOfNearestEnclosingCaptureCapableLambda( FunctionScopesArrayRef, Var, S)) { const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue(); MarkVarDeclODRUsed(Var, VarExpr->getExprLoc(), S, &FunctionScopeIndexOfCapturableLambda); } const bool IsVarNeverAConstantExpression = VariableCanNeverBeAConstantExpression(Var, S.Context); if (!IsFullExprInstantiationDependent || IsVarNeverAConstantExpression) { // This full expression is not instantiation dependent or the variable // can not be used in a constant expression - which means // this variable must be odr-used here, so diagnose a // capture violation early, if the variable is un-captureable. // This is purely for diagnosing errors early. Otherwise, this // error would get diagnosed when the lambda becomes capture ready. QualType CaptureType, DeclRefType; SourceLocation ExprLoc = VarExpr->getExprLoc(); if (S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit, /*EllipsisLoc*/ SourceLocation(), /*BuildAndDiagnose*/false, CaptureType, DeclRefType, nullptr)) { // We will never be able to capture this variable, and we need // to be able to in any and all instantiations, so diagnose it. S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit, /*EllipsisLoc*/ SourceLocation(), /*BuildAndDiagnose*/true, CaptureType, DeclRefType, nullptr); } } } // Check if 'this' needs to be captured. if (CurrentLSI->hasPotentialThisCapture()) { // If we have a capture-capable lambda for 'this', go ahead and capture // 'this' in that lambda (and all its enclosing lambdas). if (const Optional Index = getStackIndexOfNearestEnclosingCaptureCapableLambda( FunctionScopesArrayRef, /*0 is 'this'*/ nullptr, S)) { const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue(); S.CheckCXXThisCapture(CurrentLSI->PotentialThisCaptureLocation, /*Explicit*/ false, /*BuildAndDiagnose*/ true, &FunctionScopeIndexOfCapturableLambda); } } // Reset all the potential captures at the end of each full-expression. CurrentLSI->clearPotentialCaptures(); } static ExprResult attemptRecovery(Sema &SemaRef, const TypoCorrectionConsumer &Consumer, const TypoCorrection &TC) { LookupResult R(SemaRef, Consumer.getLookupResult().getLookupNameInfo(), Consumer.getLookupResult().getLookupKind()); const CXXScopeSpec *SS = Consumer.getSS(); CXXScopeSpec NewSS; // Use an approprate CXXScopeSpec for building the expr. if (auto *NNS = TC.getCorrectionSpecifier()) NewSS.MakeTrivial(SemaRef.Context, NNS, TC.getCorrectionRange()); else if (SS && !TC.WillReplaceSpecifier()) NewSS = *SS; if (auto *ND = TC.getFoundDecl()) { R.setLookupName(ND->getDeclName()); R.addDecl(ND); if (ND->isCXXClassMember()) { // Figure out the correct naming class to add to the LookupResult. CXXRecordDecl *Record = nullptr; if (auto *NNS = TC.getCorrectionSpecifier()) Record = NNS->getAsType()->getAsCXXRecordDecl(); if (!Record) Record = dyn_cast(ND->getDeclContext()->getRedeclContext()); if (Record) R.setNamingClass(Record); // Detect and handle the case where the decl might be an implicit // member. bool MightBeImplicitMember; if (!Consumer.isAddressOfOperand()) MightBeImplicitMember = true; else if (!NewSS.isEmpty()) MightBeImplicitMember = false; else if (R.isOverloadedResult()) MightBeImplicitMember = false; else if (R.isUnresolvableResult()) MightBeImplicitMember = true; else MightBeImplicitMember = isa(ND) || isa(ND) || isa(ND); if (MightBeImplicitMember) return SemaRef.BuildPossibleImplicitMemberExpr( NewSS, /*TemplateKWLoc*/ SourceLocation(), R, /*TemplateArgs*/ nullptr, /*S*/ nullptr); } else if (auto *Ivar = dyn_cast(ND)) { return SemaRef.LookupInObjCMethod(R, Consumer.getScope(), Ivar->getIdentifier()); } } return SemaRef.BuildDeclarationNameExpr(NewSS, R, /*NeedsADL*/ false, /*AcceptInvalidDecl*/ true); } namespace { class FindTypoExprs : public RecursiveASTVisitor { llvm::SmallSetVector &TypoExprs; public: explicit FindTypoExprs(llvm::SmallSetVector &TypoExprs) : TypoExprs(TypoExprs) {} bool VisitTypoExpr(TypoExpr *TE) { TypoExprs.insert(TE); return true; } }; class TransformTypos : public TreeTransform { typedef TreeTransform BaseTransform; VarDecl *InitDecl; // A decl to avoid as a correction because it is in the // process of being initialized. llvm::function_ref ExprFilter; llvm::SmallSetVector TypoExprs, AmbiguousTypoExprs; llvm::SmallDenseMap TransformCache; llvm::SmallDenseMap OverloadResolution; /// \brief Emit diagnostics for all of the TypoExprs encountered. /// If the TypoExprs were successfully corrected, then the diagnostics should /// suggest the corrections. Otherwise the diagnostics will not suggest /// anything (having been passed an empty TypoCorrection). void EmitAllDiagnostics() { for (auto E : TypoExprs) { TypoExpr *TE = cast(E); auto &State = SemaRef.getTypoExprState(TE); if (State.DiagHandler) { TypoCorrection TC = State.Consumer->getCurrentCorrection(); ExprResult Replacement = TransformCache[TE]; // Extract the NamedDecl from the transformed TypoExpr and add it to the // TypoCorrection, replacing the existing decls. This ensures the right // NamedDecl is used in diagnostics e.g. in the case where overload // resolution was used to select one from several possible decls that // had been stored in the TypoCorrection. if (auto *ND = getDeclFromExpr( Replacement.isInvalid() ? nullptr : Replacement.get())) TC.setCorrectionDecl(ND); State.DiagHandler(TC); } SemaRef.clearDelayedTypo(TE); } } /// \brief If corrections for the first TypoExpr have been exhausted for a /// given combination of the other TypoExprs, retry those corrections against /// the next combination of substitutions for the other TypoExprs by advancing /// to the next potential correction of the second TypoExpr. For the second /// and subsequent TypoExprs, if its stream of corrections has been exhausted, /// the stream is reset and the next TypoExpr's stream is advanced by one (a /// TypoExpr's correction stream is advanced by removing the TypoExpr from the /// TransformCache). Returns true if there is still any untried combinations /// of corrections. bool CheckAndAdvanceTypoExprCorrectionStreams() { for (auto TE : TypoExprs) { auto &State = SemaRef.getTypoExprState(TE); TransformCache.erase(TE); if (!State.Consumer->finished()) return true; State.Consumer->resetCorrectionStream(); } return false; } NamedDecl *getDeclFromExpr(Expr *E) { if (auto *OE = dyn_cast_or_null(E)) E = OverloadResolution[OE]; if (!E) return nullptr; if (auto *DRE = dyn_cast(E)) return DRE->getFoundDecl(); if (auto *ME = dyn_cast(E)) return ME->getFoundDecl(); // FIXME: Add any other expr types that could be be seen by the delayed typo // correction TreeTransform for which the corresponding TypoCorrection could // contain multiple decls. return nullptr; } ExprResult TryTransform(Expr *E) { Sema::SFINAETrap Trap(SemaRef); ExprResult Res = TransformExpr(E); if (Trap.hasErrorOccurred() || Res.isInvalid()) return ExprError(); return ExprFilter(Res.get()); } public: TransformTypos(Sema &SemaRef, VarDecl *InitDecl, llvm::function_ref Filter) : BaseTransform(SemaRef), InitDecl(InitDecl), ExprFilter(Filter) {} ExprResult RebuildCallExpr(Expr *Callee, SourceLocation LParenLoc, MultiExprArg Args, SourceLocation RParenLoc, Expr *ExecConfig = nullptr) { auto Result = BaseTransform::RebuildCallExpr(Callee, LParenLoc, Args, RParenLoc, ExecConfig); if (auto *OE = dyn_cast(Callee)) { if (Result.isUsable()) { Expr *ResultCall = Result.get(); if (auto *BE = dyn_cast(ResultCall)) ResultCall = BE->getSubExpr(); if (auto *CE = dyn_cast(ResultCall)) OverloadResolution[OE] = CE->getCallee(); } } return Result; } ExprResult TransformLambdaExpr(LambdaExpr *E) { return Owned(E); } ExprResult TransformBlockExpr(BlockExpr *E) { return Owned(E); } ExprResult TransformObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { return Owned(E); } ExprResult TransformObjCIvarRefExpr(ObjCIvarRefExpr *E) { return Owned(E); } ExprResult Transform(Expr *E) { ExprResult Res; while (true) { Res = TryTransform(E); // Exit if either the transform was valid or if there were no TypoExprs // to transform that still have any untried correction candidates.. if (!Res.isInvalid() || !CheckAndAdvanceTypoExprCorrectionStreams()) break; } // Ensure none of the TypoExprs have multiple typo correction candidates // with the same edit length that pass all the checks and filters. // TODO: Properly handle various permutations of possible corrections when // there is more than one potentially ambiguous typo correction. // Also, disable typo correction while attempting the transform when // handling potentially ambiguous typo corrections as any new TypoExprs will // have been introduced by the application of one of the correction // candidates and add little to no value if corrected. SemaRef.DisableTypoCorrection = true; while (!AmbiguousTypoExprs.empty()) { auto TE = AmbiguousTypoExprs.back(); auto Cached = TransformCache[TE]; auto &State = SemaRef.getTypoExprState(TE); State.Consumer->saveCurrentPosition(); TransformCache.erase(TE); if (!TryTransform(E).isInvalid()) { State.Consumer->resetCorrectionStream(); TransformCache.erase(TE); Res = ExprError(); break; } AmbiguousTypoExprs.remove(TE); State.Consumer->restoreSavedPosition(); TransformCache[TE] = Cached; } SemaRef.DisableTypoCorrection = false; // Ensure that all of the TypoExprs within the current Expr have been found. if (!Res.isUsable()) FindTypoExprs(TypoExprs).TraverseStmt(E); EmitAllDiagnostics(); return Res; } ExprResult TransformTypoExpr(TypoExpr *E) { // If the TypoExpr hasn't been seen before, record it. Otherwise, return the // cached transformation result if there is one and the TypoExpr isn't the // first one that was encountered. auto &CacheEntry = TransformCache[E]; if (!TypoExprs.insert(E) && !CacheEntry.isUnset()) { return CacheEntry; } auto &State = SemaRef.getTypoExprState(E); assert(State.Consumer && "Cannot transform a cleared TypoExpr"); // For the first TypoExpr and an uncached TypoExpr, find the next likely // typo correction and return it. while (TypoCorrection TC = State.Consumer->getNextCorrection()) { if (InitDecl && TC.getFoundDecl() == InitDecl) continue; ExprResult NE = State.RecoveryHandler ? State.RecoveryHandler(SemaRef, E, TC) : attemptRecovery(SemaRef, *State.Consumer, TC); if (!NE.isInvalid()) { // Check whether there may be a second viable correction with the same // edit distance; if so, remember this TypoExpr may have an ambiguous // correction so it can be more thoroughly vetted later. TypoCorrection Next; if ((Next = State.Consumer->peekNextCorrection()) && Next.getEditDistance(false) == TC.getEditDistance(false)) { AmbiguousTypoExprs.insert(E); } else { AmbiguousTypoExprs.remove(E); } assert(!NE.isUnset() && "Typo was transformed into a valid-but-null ExprResult"); return CacheEntry = NE; } } return CacheEntry = ExprError(); } }; } ExprResult Sema::CorrectDelayedTyposInExpr(Expr *E, VarDecl *InitDecl, llvm::function_ref Filter) { // If the current evaluation context indicates there are uncorrected typos // and the current expression isn't guaranteed to not have typos, try to // resolve any TypoExpr nodes that might be in the expression. if (E && !ExprEvalContexts.empty() && ExprEvalContexts.back().NumTypos && (E->isTypeDependent() || E->isValueDependent() || E->isInstantiationDependent())) { auto TyposInContext = ExprEvalContexts.back().NumTypos; assert(TyposInContext < ~0U && "Recursive call of CorrectDelayedTyposInExpr"); ExprEvalContexts.back().NumTypos = ~0U; auto TyposResolved = DelayedTypos.size(); auto Result = TransformTypos(*this, InitDecl, Filter).Transform(E); ExprEvalContexts.back().NumTypos = TyposInContext; TyposResolved -= DelayedTypos.size(); if (Result.isInvalid() || Result.get() != E) { ExprEvalContexts.back().NumTypos -= TyposResolved; return Result; } assert(TyposResolved == 0 && "Corrected typo but got same Expr back?"); } return E; } ExprResult Sema::ActOnFinishFullExpr(Expr *FE, SourceLocation CC, bool DiscardedValue, bool IsConstexpr, bool IsLambdaInitCaptureInitializer) { ExprResult FullExpr = FE; if (!FullExpr.get()) return ExprError(); // If we are an init-expression in a lambdas init-capture, we should not // diagnose an unexpanded pack now (will be diagnosed once lambda-expr // containing full-expression is done). // template void test(Ts ... t) { // test([&a(t)]() { <-- (t) is an init-expr that shouldn't be diagnosed now. // return a; // }() ...); // } // FIXME: This is a hack. It would be better if we pushed the lambda scope // when we parse the lambda introducer, and teach capturing (but not // unexpanded pack detection) to walk over LambdaScopeInfos which don't have a // corresponding class yet (that is, have LambdaScopeInfo either represent a // lambda where we've entered the introducer but not the body, or represent a // lambda where we've entered the body, depending on where the // parser/instantiation has got to). if (!IsLambdaInitCaptureInitializer && DiagnoseUnexpandedParameterPack(FullExpr.get())) return ExprError(); // Top-level expressions default to 'id' when we're in a debugger. if (DiscardedValue && getLangOpts().DebuggerCastResultToId && FullExpr.get()->getType() == Context.UnknownAnyTy) { FullExpr = forceUnknownAnyToType(FullExpr.get(), Context.getObjCIdType()); if (FullExpr.isInvalid()) return ExprError(); } if (DiscardedValue) { FullExpr = CheckPlaceholderExpr(FullExpr.get()); if (FullExpr.isInvalid()) return ExprError(); FullExpr = IgnoredValueConversions(FullExpr.get()); if (FullExpr.isInvalid()) return ExprError(); } FullExpr = CorrectDelayedTyposInExpr(FullExpr.get()); if (FullExpr.isInvalid()) return ExprError(); CheckCompletedExpr(FullExpr.get(), CC, IsConstexpr); // At the end of this full expression (which could be a deeply nested // lambda), if there is a potential capture within the nested lambda, // have the outer capture-able lambda try and capture it. // Consider the following code: // void f(int, int); // void f(const int&, double); // void foo() { // const int x = 10, y = 20; // auto L = [=](auto a) { // auto M = [=](auto b) { // f(x, b); <-- requires x to be captured by L and M // f(y, a); <-- requires y to be captured by L, but not all Ms // }; // }; // } // FIXME: Also consider what happens for something like this that involves // the gnu-extension statement-expressions or even lambda-init-captures: // void f() { // const int n = 0; // auto L = [&](auto a) { // +n + ({ 0; a; }); // }; // } // // Here, we see +n, and then the full-expression 0; ends, so we don't // capture n (and instead remove it from our list of potential captures), // and then the full-expression +n + ({ 0; }); ends, but it's too late // for us to see that we need to capture n after all. LambdaScopeInfo *const CurrentLSI = getCurLambda(); // FIXME: PR 17877 showed that getCurLambda() can return a valid pointer // even if CurContext is not a lambda call operator. Refer to that Bug Report // for an example of the code that might cause this asynchrony. // By ensuring we are in the context of a lambda's call operator // we can fix the bug (we only need to check whether we need to capture // if we are within a lambda's body); but per the comments in that // PR, a proper fix would entail : // "Alternative suggestion: // - Add to Sema an integer holding the smallest (outermost) scope // index that we are *lexically* within, and save/restore/set to // FunctionScopes.size() in InstantiatingTemplate's // constructor/destructor. // - Teach the handful of places that iterate over FunctionScopes to // stop at the outermost enclosing lexical scope." const bool IsInLambdaDeclContext = isLambdaCallOperator(CurContext); if (IsInLambdaDeclContext && CurrentLSI && CurrentLSI->hasPotentialCaptures() && !FullExpr.isInvalid()) CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(FE, CurrentLSI, *this); return MaybeCreateExprWithCleanups(FullExpr); } StmtResult Sema::ActOnFinishFullStmt(Stmt *FullStmt) { if (!FullStmt) return StmtError(); return MaybeCreateStmtWithCleanups(FullStmt); } Sema::IfExistsResult Sema::CheckMicrosoftIfExistsSymbol(Scope *S, CXXScopeSpec &SS, const DeclarationNameInfo &TargetNameInfo) { DeclarationName TargetName = TargetNameInfo.getName(); if (!TargetName) return IER_DoesNotExist; // If the name itself is dependent, then the result is dependent. if (TargetName.isDependentName()) return IER_Dependent; // Do the redeclaration lookup in the current scope. LookupResult R(*this, TargetNameInfo, Sema::LookupAnyName, Sema::NotForRedeclaration); LookupParsedName(R, S, &SS); R.suppressDiagnostics(); switch (R.getResultKind()) { case LookupResult::Found: case LookupResult::FoundOverloaded: case LookupResult::FoundUnresolvedValue: case LookupResult::Ambiguous: return IER_Exists; case LookupResult::NotFound: return IER_DoesNotExist; case LookupResult::NotFoundInCurrentInstantiation: return IER_Dependent; } llvm_unreachable("Invalid LookupResult Kind!"); } Sema::IfExistsResult Sema::CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc, bool IsIfExists, CXXScopeSpec &SS, UnqualifiedId &Name) { DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name); // Check for unexpanded parameter packs. SmallVector Unexpanded; collectUnexpandedParameterPacks(SS, Unexpanded); collectUnexpandedParameterPacks(TargetNameInfo, Unexpanded); if (!Unexpanded.empty()) { DiagnoseUnexpandedParameterPacks(KeywordLoc, IsIfExists? UPPC_IfExists : UPPC_IfNotExists, Unexpanded); return IER_Error; } return CheckMicrosoftIfExistsSymbol(S, SS, TargetNameInfo); }