//===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// /// /// \file /// Implements semantic analysis for C++ expressions. /// //===----------------------------------------------------------------------===// #include "clang/Sema/Template.h" #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/AlignedAllocation.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; /// 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::getConstructorName(IdentifierInfo &II, SourceLocation NameLoc, Scope *S, CXXScopeSpec &SS, bool EnteringContext) { CXXRecordDecl *CurClass = getCurrentClass(S, &SS); assert(CurClass && &II == CurClass->getIdentifier() && "not a constructor name"); // When naming a constructor as a member of a dependent context (eg, in a // friend declaration or an inherited constructor declaration), form an // unresolved "typename" type. if (CurClass->isDependentContext() && !EnteringContext && SS.getScopeRep()) { QualType T = Context.getDependentNameType(ETK_None, SS.getScopeRep(), &II); return ParsedType::make(T); } if (SS.isNotEmpty() && RequireCompleteDeclContext(SS, CurClass)) return ParsedType(); // Find the injected-class-name declaration. Note that we make no attempt to // diagnose cases where the injected-class-name is shadowed: the only // declaration that can validly shadow the injected-class-name is a // non-static data member, and if the class contains both a non-static data // member and a constructor then it is ill-formed (we check that in // CheckCompletedCXXClass). CXXRecordDecl *InjectedClassName = nullptr; for (NamedDecl *ND : CurClass->lookup(&II)) { auto *RD = dyn_cast(ND); if (RD && RD->isInjectedClassName()) { InjectedClassName = RD; break; } } if (!InjectedClassName) { if (!CurClass->isInvalidDecl()) { // FIXME: RequireCompleteDeclContext doesn't check dependent contexts // properly. Work around it here for now. Diag(SS.getLastQualifierNameLoc(), diag::err_incomplete_nested_name_spec) << CurClass << SS.getRange(); } return ParsedType(); } QualType T = Context.getTypeDeclType(InjectedClassName); DiagnoseUseOfDecl(InjectedClassName, NameLoc); MarkAnyDeclReferenced(NameLoc, InjectedClassName, /*OdrUse=*/false); return ParsedType::make(T); } 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 now, we accept all the cases in which the name given could plausibly // be interpreted as a correct destructor name, issuing off-by-default // extension diagnostics on the cases that don't strictly conform to the // C++20 rules. This basically means we always consider looking in the // nested-name-specifier prefix, the complete nested-name-specifier, and // the scope, and accept if we find the expected type in any of the three // places. if (SS.isInvalid()) return nullptr; // Whether we've failed with a diagnostic already. bool Failed = false; llvm::SmallVector FoundDecls; llvm::SmallPtrSet, 8> FoundDeclSet; // 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. QualType SearchType = ObjectTypePtr ? GetTypeFromParser(ObjectTypePtr) : QualType(); auto CheckLookupResult = [&](LookupResult &Found) -> ParsedType { auto IsAcceptableResult = [&](NamedDecl *D) -> bool { auto *Type = dyn_cast(D->getUnderlyingDecl()); if (!Type) return false; if (SearchType.isNull() || SearchType->isDependentType()) return true; QualType T = Context.getTypeDeclType(Type); return Context.hasSameUnqualifiedType(T, SearchType); }; unsigned NumAcceptableResults = 0; for (NamedDecl *D : Found) { if (IsAcceptableResult(D)) ++NumAcceptableResults; // Don't list a class twice in the lookup failure diagnostic if it's // found by both its injected-class-name and by the name in the enclosing // scope. if (auto *RD = dyn_cast(D)) if (RD->isInjectedClassName()) D = cast(RD->getParent()); if (FoundDeclSet.insert(D).second) FoundDecls.push_back(D); } // As an extension, attempt to "fix" an ambiguity by erasing all non-type // results, and all non-matching results if we have a search type. It's not // clear what the right behavior is if destructor lookup hits an ambiguity, // but other compilers do generally accept at least some kinds of // ambiguity. if (Found.isAmbiguous() && NumAcceptableResults == 1) { Diag(NameLoc, diag::ext_dtor_name_ambiguous); LookupResult::Filter F = Found.makeFilter(); while (F.hasNext()) { NamedDecl *D = F.next(); if (auto *TD = dyn_cast(D->getUnderlyingDecl())) Diag(D->getLocation(), diag::note_destructor_type_here) << Context.getTypeDeclType(TD); else Diag(D->getLocation(), diag::note_destructor_nontype_here); if (!IsAcceptableResult(D)) F.erase(); } F.done(); } if (Found.isAmbiguous()) Failed = true; if (TypeDecl *Type = Found.getAsSingle()) { if (IsAcceptableResult(Type)) { QualType T = Context.getTypeDeclType(Type); MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false); return CreateParsedType(T, Context.getTrivialTypeSourceInfo(T, NameLoc)); } } return nullptr; }; bool IsDependent = false; auto LookupInObjectType = [&]() -> ParsedType { if (Failed || SearchType.isNull()) return nullptr; IsDependent |= SearchType->isDependentType(); LookupResult Found(*this, &II, NameLoc, LookupDestructorName); DeclContext *LookupCtx = computeDeclContext(SearchType); if (!LookupCtx) return nullptr; LookupQualifiedName(Found, LookupCtx); return CheckLookupResult(Found); }; auto LookupInNestedNameSpec = [&](CXXScopeSpec &LookupSS) -> ParsedType { if (Failed) return nullptr; IsDependent |= isDependentScopeSpecifier(LookupSS); DeclContext *LookupCtx = computeDeclContext(LookupSS, EnteringContext); if (!LookupCtx) return nullptr; LookupResult Found(*this, &II, NameLoc, LookupDestructorName); if (RequireCompleteDeclContext(LookupSS, LookupCtx)) { Failed = true; return nullptr; } LookupQualifiedName(Found, LookupCtx); return CheckLookupResult(Found); }; auto LookupInScope = [&]() -> ParsedType { if (Failed || !S) return nullptr; LookupResult Found(*this, &II, NameLoc, LookupDestructorName); LookupName(Found, S); return CheckLookupResult(Found); }; // C++2a [basic.lookup.qual]p6: // In a qualified-id of the form // // nested-name-specifier[opt] type-name :: ~ type-name // // the second type-name is looked up in the same scope as the first. // // We interpret this as meaning that if you do a dual-scope lookup for the // first name, you also do a dual-scope lookup for the second name, per // C++ [basic.lookup.classref]p4: // // If the id-expression in a class member access is a qualified-id of the // form // // class-name-or-namespace-name :: ... // // the class-name-or-namespace-name following the . or -> is first looked // up in the class of the object expression and the name, if found, is used. // Otherwise, it is looked up in the context of the entire // postfix-expression. // // This looks in the same scopes as for an unqualified destructor name: // // 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 cv T. // // FIXME: The intent is unclear here. Should type-name::~type-name look in // the scope anyway if it finds a non-matching name declared in the class? // If both lookups succeed and find a dependent result, which result should // we retain? (Same question for p->~type-name().) if (NestedNameSpecifier *Prefix = SS.isSet() ? SS.getScopeRep()->getPrefix() : nullptr) { // This is // // nested-name-specifier type-name :: ~ type-name // // Look for the second type-name in the nested-name-specifier. CXXScopeSpec PrefixSS; PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data())); if (ParsedType T = LookupInNestedNameSpec(PrefixSS)) return T; } else { // This is one of // // type-name :: ~ type-name // ~ type-name // // Look in the scope and (if any) the object type. if (ParsedType T = LookupInScope()) return T; if (ParsedType T = LookupInObjectType()) return T; } if (Failed) return nullptr; if (IsDependent) { // We didn't find our type, but that's OK: 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); } // The remaining cases are all non-standard extensions imitating the behavior // of various other compilers. unsigned NumNonExtensionDecls = FoundDecls.size(); if (SS.isSet()) { // For compatibility with older broken C++ rules and existing code, // // nested-name-specifier :: ~ type-name // // also looks for type-name within the nested-name-specifier. if (ParsedType T = LookupInNestedNameSpec(SS)) { Diag(SS.getEndLoc(), diag::ext_dtor_named_in_wrong_scope) << SS.getRange() << FixItHint::CreateInsertion(SS.getEndLoc(), ("::" + II.getName()).str()); return T; } // For compatibility with other compilers and older versions of Clang, // // nested-name-specifier type-name :: ~ type-name // // also looks for type-name in the scope. Unfortunately, we can't // reasonably apply this fallback for dependent nested-name-specifiers. if (SS.getScopeRep()->getPrefix()) { if (ParsedType T = LookupInScope()) { Diag(SS.getEndLoc(), diag::ext_qualified_dtor_named_in_lexical_scope) << FixItHint::CreateRemoval(SS.getRange()); Diag(FoundDecls.back()->getLocation(), diag::note_destructor_type_here) << GetTypeFromParser(T); return T; } } } // We didn't find anything matching; tell the user what we did find (if // anything). // Don't tell the user about declarations we shouldn't have found. FoundDecls.resize(NumNonExtensionDecls); // List types before non-types. std::stable_sort(FoundDecls.begin(), FoundDecls.end(), [](NamedDecl *A, NamedDecl *B) { return isa(A->getUnderlyingDecl()) > isa(B->getUnderlyingDecl()); }); // Suggest a fixit to properly name the destroyed type. auto MakeFixItHint = [&]{ const CXXRecordDecl *Destroyed = nullptr; // FIXME: If we have a scope specifier, suggest its last component? if (!SearchType.isNull()) Destroyed = SearchType->getAsCXXRecordDecl(); else if (S) Destroyed = dyn_cast_or_null(S->getEntity()); if (Destroyed) return FixItHint::CreateReplacement(SourceRange(NameLoc), Destroyed->getNameAsString()); return FixItHint(); }; if (FoundDecls.empty()) { // FIXME: Attempt typo-correction? Diag(NameLoc, diag::err_undeclared_destructor_name) << &II << MakeFixItHint(); } else if (!SearchType.isNull() && FoundDecls.size() == 1) { if (auto *TD = dyn_cast(FoundDecls[0]->getUnderlyingDecl())) { assert(!SearchType.isNull() && "should only reject a type result if we have a search type"); QualType T = Context.getTypeDeclType(TD); Diag(NameLoc, diag::err_destructor_expr_type_mismatch) << T << SearchType << MakeFixItHint(); } else { Diag(NameLoc, diag::err_destructor_expr_nontype) << &II << MakeFixItHint(); } } else { Diag(NameLoc, SearchType.isNull() ? diag::err_destructor_name_nontype : diag::err_destructor_expr_mismatch) << &II << SearchType << MakeFixItHint(); } for (NamedDecl *FoundD : FoundDecls) { if (auto *TD = dyn_cast(FoundD->getUnderlyingDecl())) Diag(FoundD->getLocation(), diag::note_destructor_type_here) << Context.getTypeDeclType(TD); else Diag(FoundD->getLocation(), diag::note_destructor_nontype_here) << FoundD; } return nullptr; } ParsedType Sema::getDestructorTypeForDecltype(const DeclSpec &DS, ParsedType ObjectType) { if (DS.getTypeSpecType() == DeclSpec::TST_error) return nullptr; if (DS.getTypeSpecType() == DeclSpec::TST_decltype_auto) { Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid); return nullptr; } assert(DS.getTypeSpecType() == DeclSpec::TST_decltype && "unexpected type in getDestructorType"); QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc()); // If we know the type of the object, check that the correct destructor // type was named now; we can give better diagnostics this way. QualType SearchType = GetTypeFromParser(ObjectType); if (!SearchType.isNull() && !SearchType->isDependentType() && !Context.hasSameUnqualifiedType(T, SearchType)) { Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch) << T << SearchType; return nullptr; } return ParsedType::make(T); } bool Sema::checkLiteralOperatorId(const CXXScopeSpec &SS, const UnqualifiedId &Name) { assert(Name.getKind() == UnqualifiedIdKind::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.getBeginLoc(), 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"); } /// 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); if (CheckQualifiedFunctionForTypeId(T, TypeidLoc)) return ExprError(); return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), Operand, SourceRange(TypeidLoc, RParenLoc)); } /// 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; } } ExprResult Result = CheckUnevaluatedOperand(E); if (Result.isInvalid()) return ExprError(); E = Result.get(); // 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 (!inTemplateInstantiation() && 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) { // typeid is not supported in OpenCL. if (getLangOpts().OpenCLCPlusPlus) { return ExprError(Diag(OpLoc, diag::err_openclcxx_not_supported) << "typeid"); } // 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. ExprResult Result = BuildCXXTypeId(TypeInfoType, OpLoc, (Expr *)TyOrExpr, RParenLoc); if (!getLangOpts().RTTIData && !Result.isInvalid()) if (auto *CTE = dyn_cast(Result.get())) if (CTE->isPotentiallyEvaluated() && !CTE->isMostDerived(Context)) Diag(OpLoc, diag::warn_no_typeid_with_rtti_disabled) << (getDiagnostics().getDiagnosticOptions().getFormat() == DiagnosticOptions::MSVC); return Result; } /// 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 *TD = Ty->getAsTagDecl(); if (!TD) return; if (const auto *Uuid = TD->getMostRecentDecl()->getAttr()) { UuidAttrs.insert(Uuid); return; } // __uuidof can grab UUIDs from template arguments. if (const auto *CTSD = dyn_cast(TD)) { 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); } } } /// Build a Microsoft __uuidof expression with a type operand. ExprResult Sema::BuildCXXUuidof(QualType Type, SourceLocation TypeidLoc, TypeSourceInfo *Operand, SourceLocation RParenLoc) { MSGuidDecl *Guid = nullptr; 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)); Guid = UuidAttrs.back()->getGuidDecl(); } return new (Context) CXXUuidofExpr(Type, Operand, Guid, SourceRange(TypeidLoc, RParenLoc)); } /// Build a Microsoft __uuidof expression with an expression operand. ExprResult Sema::BuildCXXUuidof(QualType Type, SourceLocation TypeidLoc, Expr *E, SourceLocation RParenLoc) { MSGuidDecl *Guid = nullptr; if (!E->getType()->isDependentType()) { if (E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { // A null pointer results in {00000000-0000-0000-0000-000000000000}. Guid = Context.getMSGuidDecl(MSGuidDecl::Parts{}); } 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)); Guid = UuidAttrs.back()->getGuidDecl(); } } return new (Context) CXXUuidofExpr(Type, E, Guid, SourceRange(TypeidLoc, RParenLoc)); } /// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression); ExprResult Sema::ActOnCXXUuidof(SourceLocation OpLoc, SourceLocation LParenLoc, bool isType, void *TyOrExpr, SourceLocation RParenLoc) { QualType GuidType = Context.getMSGuidType(); GuidType.addConst(); 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) && !getLangOpts().CUDA) { // Delay error emission for the OpenMP device code. targetDiag(OpLoc, diag::err_exceptions_disabled) << "throw"; } // Exceptions aren't allowed in CUDA device code. if (getLangOpts().CUDA) CUDADiagIfDeviceCode(OpLoc, diag::err_cuda_device_exceptions) << "throw" << CurrentCUDATarget(); 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, CES_Strict); 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(); } // PPC MMA non-pointer types are not allowed as throw expr types. if (Ex && Context.getTargetInfo().getTriple().isPPC64()) CheckPPCMMAType(Ex->getType(), Ex->getBeginLoc()); 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 (!isPointer && Ty->isSizelessType()) { Diag(ThrowLoc, diag::err_throw_sizeless) << Ty << 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 || CD->isDeleted()) 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) { if (CheckCXXDefaultArgExpr(ThrowLoc, CD, CD->getParamDecl(I))) return true; } } } // Under the Itanium C++ ABI, memory for the exception object is allocated by // the runtime with no ability for the compiler to request additional // alignment. Warn if the exception type requires alignment beyond the minimum // guaranteed by the target C++ runtime. if (Context.getTargetInfo().getCXXABI().isItaniumFamily()) { CharUnits TypeAlign = Context.getTypeAlignInChars(Ty); CharUnits ExnObjAlign = Context.getExnObjectAlignment(); if (ExnObjAlign < TypeAlign) { Diag(ThrowLoc, diag::warn_throw_underaligned_obj); Diag(ThrowLoc, diag::note_throw_underaligned_obj) << Ty << (unsigned)TypeAlign.getQuantity() << (unsigned)ExnObjAlign.getQuantity(); } } 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. // // Since the FunctionScopeInfo stack is representative of the lexical // nesting of the lambda expressions during initial parsing (and is the best // place for querying information about captures about lambdas that are // partially processed) and perhaps during instantiation of function templates // that contain lambda expressions that need to be transformed BUT not // necessarily during instantiation of a nested generic lambda's function call // operator (which might even be instantiated at the end of the TU) - at which // time the DeclContext tree is mature enough to query capture information // reliably - we use a two pronged approach to walk through all the lexically // enclosing lambda expressions: // // 1) Climb down the FunctionScopeInfo stack as long as each item represents // a Lambda (i.e. LambdaScopeInfo) AND each LSI's 'closure-type' is lexically // enclosed by the call-operator of the LSI below it on the stack (while // tracking the enclosing DC for step 2 if needed). Note the topmost LSI on // the stack represents the innermost lambda. // // 2) If we run out of enclosing LSI's, check if the enclosing DeclContext // represents a lambda's call operator. If it does, we must be instantiating // a generic lambda's call operator (represented by the Current LSI, and // should be the only scenario where an inconsistency between the LSI and the // DeclContext should occur), so climb out the DeclContexts if they // represent lambdas, while querying the corresponding closure types // regarding capture information. // 1) Climb down the function scope info stack. for (int I = FunctionScopes.size(); I-- && isa(FunctionScopes[I]) && (!CurLSI || !CurLSI->Lambda || CurLSI->Lambda->getDeclContext() == cast(FunctionScopes[I])->CallOperator); 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); } } // 2) We've run out of ScopeInfos but check if CurDC is a lambda (which can // happen during instantiation of its nested generic lambda call operator) if (isLambdaCallOperator(CurDC)) { assert(CurLSI && "While computing 'this' capture-type for a generic " "lambda, we must have a corresponding LambdaScopeInfo"); assert(isGenericLambdaCallOperatorSpecialization(CurLSI->CallOperator) && "While computing 'this' capture-type for a generic lambda, when we " "run out of enclosing LSI's, yet the enclosing DC is a " "lambda-call-operator we must be (i.e. Current LSI) in a generic " "lambda call oeprator"); 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(); } if (ThisTy.isNull() && isLambdaCallOperator(CurContext) && inTemplateInstantiation() && isa(DC)) { // This is a lambda call operator that is being instantiated as a default // initializer. DC must point to the enclosing class type, so we can recover // the 'this' type from it. QualType ClassTy = Context.getTypeDeclType(cast(DC)); // 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, Qualifiers 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); QualType T = S.Context.getRecordType(Record); T = S.getASTContext().getQualifiedType(T, CXXThisTypeQuals); S.CXXThisTypeOverride = S.Context.getPointerType(T); this->Enabled = true; } Sema::CXXThisScopeRAII::~CXXThisScopeRAII() { if (Enabled) { S.CXXThisTypeOverride = OldCXXThisTypeOverride; } } static void buildLambdaThisCaptureFixit(Sema &Sema, LambdaScopeInfo *LSI) { SourceLocation DiagLoc = LSI->IntroducerRange.getEnd(); assert(!LSI->isCXXThisCaptured()); // [=, this] {}; // until C++20: Error: this when = is the default if (LSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval && !Sema.getLangOpts().CPlusPlus20) return; Sema.Diag(DiagLoc, diag::note_lambda_this_capture_fixit) << FixItHint::CreateInsertion( DiagLoc, LSI->NumExplicitCaptures > 0 ? ", this" : "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 int 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 (int 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. CSI->Captures[CSI->CXXThisCaptureIndex - 1].markUsed(BuildAndDiagnose); 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); if (!Explicit) buildLambdaThisCaptureFixit(*this, LSI); } 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); if (!Explicit) buildLambdaThisCaptureFixit(*this, LSI); 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 up to 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"); QualType ThisTy = getCurrentThisType(); for (int idx = MaxFunctionScopesIndex; NumCapturingClosures; --idx, --NumCapturingClosures) { CapturingScopeInfo *CSI = cast(FunctionScopes[idx]); // The type of the corresponding data member (not a 'this' pointer if 'by // copy'). QualType CaptureType = 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'. CaptureType = ThisTy->getPointeeType(); CaptureType.removeLocalCVRQualifiers(Qualifiers::CVRMask); } bool isNested = NumCapturingClosures > 1; CSI->addThisCapture(isNested, Loc, CaptureType, 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); return BuildCXXThisExpr(Loc, ThisTy, /*IsImplicit=*/false); } Expr *Sema::BuildCXXThisExpr(SourceLocation Loc, QualType Type, bool IsImplicit) { auto *This = new (Context) CXXThisExpr(Loc, Type, IsImplicit); MarkThisReferenced(This); return This; } void Sema::MarkThisReferenced(CXXThisExpr *This) { CheckCXXThisCapture(This->getExprLoc()); } 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(); } /// 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::ActOnCXXTypeConstructExpr(ParsedType TypeRep, SourceLocation LParenOrBraceLoc, MultiExprArg exprs, SourceLocation RParenOrBraceLoc, bool ListInitialization) { if (!TypeRep) return ExprError(); TypeSourceInfo *TInfo; QualType Ty = GetTypeFromParser(TypeRep, &TInfo); if (!TInfo) TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation()); auto Result = BuildCXXTypeConstructExpr(TInfo, LParenOrBraceLoc, exprs, RParenOrBraceLoc, ListInitialization); // 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()); else if (Result.isInvalid()) Result = CreateRecoveryExpr(TInfo->getTypeLoc().getBeginLoc(), RParenOrBraceLoc, exprs, Ty); return Result; } ExprResult Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo, SourceLocation LParenOrBraceLoc, MultiExprArg Exprs, SourceLocation RParenOrBraceLoc, bool ListInitialization) { QualType Ty = TInfo->getType(); SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc(); assert((!ListInitialization || (Exprs.size() == 1 && isa(Exprs[0]))) && "List initialization must have initializer list as expression."); SourceRange FullRange = SourceRange(TyBeginLoc, RParenOrBraceLoc); InitializedEntity Entity = InitializedEntity::InitializeTemporary(TInfo); InitializationKind Kind = Exprs.size() ? ListInitialization ? InitializationKind::CreateDirectList( TyBeginLoc, LParenOrBraceLoc, RParenOrBraceLoc) : InitializationKind::CreateDirect(TyBeginLoc, LParenOrBraceLoc, RParenOrBraceLoc) : InitializationKind::CreateValue(TyBeginLoc, LParenOrBraceLoc, RParenOrBraceLoc); // C++1z [expr.type.conv]p1: // If the type is a placeholder for a deduced class type, [...perform class // template argument deduction...] DeducedType *Deduced = Ty->getContainedDeducedType(); if (Deduced && isa(Deduced)) { Ty = DeduceTemplateSpecializationFromInitializer(TInfo, Entity, Kind, Exprs); if (Ty.isNull()) return ExprError(); Entity = InitializedEntity::InitializeTemporary(TInfo, Ty); } if (Ty->isDependentType() || CallExpr::hasAnyTypeDependentArguments(Exprs)) { // FIXME: CXXUnresolvedConstructExpr does not model list-initialization // directly. We work around this by dropping the locations of the braces. SourceRange Locs = ListInitialization ? SourceRange() : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc); return CXXUnresolvedConstructExpr::Create(Context, Ty.getNonReferenceType(), TInfo, Locs.getBegin(), Exprs, Locs.getEnd()); } // C++ [expr.type.conv]p1: // If the expression list is a parenthesized 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 && !isa(Exprs[0])) { Expr *Arg = Exprs[0]; return BuildCXXFunctionalCastExpr(TInfo, Ty, LParenOrBraceLoc, Arg, RParenOrBraceLoc); } // For an expression of the form T(), T shall not be an array type. QualType ElemTy = Ty; if (Ty->isArrayType()) { if (!ListInitialization) return ExprError(Diag(TyBeginLoc, diag::err_value_init_for_array_type) << FullRange); ElemTy = Context.getBaseElementType(Ty); } // There doesn't seem to be an explicit rule against this but sanity demands // we only construct objects with object types. if (Ty->isFunctionType()) return ExprError(Diag(TyBeginLoc, diag::err_init_for_function_type) << Ty << FullRange); // C++17 [expr.type.conv]p2: // If the type is cv void and the initializer is (), the expression is a // prvalue of the specified type that performs no initialization. if (!Ty->isVoidType() && RequireCompleteType(TyBeginLoc, ElemTy, diag::err_invalid_incomplete_type_use, FullRange)) return ExprError(); // Otherwise, the expression is a prvalue of the specified type whose // result object is direct-initialized (11.6) with the initializer. InitializationSequence InitSeq(*this, Entity, Kind, Exprs); ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs); if (Result.isInvalid()) return Result; Expr *Inner = Result.get(); if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null(Inner)) Inner = BTE->getSubExpr(); if (!isa(Inner) && !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(); SourceRange Locs = ListInitialization ? SourceRange() : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc); Result = CXXFunctionalCastExpr::Create( Context, ResultType, Expr::getValueKindForType(Ty), TInfo, CK_NoOp, Result.get(), /*Path=*/nullptr, CurFPFeatureOverrides(), Locs.getBegin(), Locs.getEnd()); } return Result; } bool Sema::isUsualDeallocationFunction(const CXXMethodDecl *Method) { // [CUDA] Ignore this function, if we can't call it. const FunctionDecl *Caller = dyn_cast(CurContext); if (getLangOpts().CUDA) { auto CallPreference = IdentifyCUDAPreference(Caller, Method); // If it's not callable at all, it's not the right function. if (CallPreference < CFP_WrongSide) return false; if (CallPreference == CFP_WrongSide) { // Maybe. We have to check if there are better alternatives. DeclContext::lookup_result R = Method->getDeclContext()->lookup(Method->getDeclName()); for (const auto *D : R) { if (const auto *FD = dyn_cast(D)) { if (IdentifyCUDAPreference(Caller, FD) > CFP_WrongSide) return false; } } // We've found no better variants. } } SmallVector PreventedBy; bool Result = Method->isUsualDeallocationFunction(PreventedBy); if (Result || !getLangOpts().CUDA || PreventedBy.empty()) return Result; // In case of CUDA, return true if none of the 1-argument deallocator // functions are actually callable. return llvm::none_of(PreventedBy, [&](const FunctionDecl *FD) { assert(FD->getNumParams() == 1 && "Only single-operand functions should be in PreventedBy"); return IdentifyCUDAPreference(Caller, FD) >= CFP_HostDevice; }); } /// Determine whether the given function is a non-placement /// deallocation function. static bool isNonPlacementDeallocationFunction(Sema &S, FunctionDecl *FD) { if (CXXMethodDecl *Method = dyn_cast(FD)) return S.isUsualDeallocationFunction(Method); if (FD->getOverloadedOperator() != OO_Delete && FD->getOverloadedOperator() != OO_Array_Delete) return false; unsigned UsualParams = 1; if (S.getLangOpts().SizedDeallocation && UsualParams < FD->getNumParams() && S.Context.hasSameUnqualifiedType( FD->getParamDecl(UsualParams)->getType(), S.Context.getSizeType())) ++UsualParams; if (S.getLangOpts().AlignedAllocation && UsualParams < FD->getNumParams() && S.Context.hasSameUnqualifiedType( FD->getParamDecl(UsualParams)->getType(), S.Context.getTypeDeclType(S.getStdAlignValT()))) ++UsualParams; return UsualParams == FD->getNumParams(); } namespace { struct UsualDeallocFnInfo { UsualDeallocFnInfo() : Found(), FD(nullptr) {} UsualDeallocFnInfo(Sema &S, DeclAccessPair Found) : Found(Found), FD(dyn_cast(Found->getUnderlyingDecl())), Destroying(false), HasSizeT(false), HasAlignValT(false), CUDAPref(Sema::CFP_Native) { // A function template declaration is never a usual deallocation function. if (!FD) return; unsigned NumBaseParams = 1; if (FD->isDestroyingOperatorDelete()) { Destroying = true; ++NumBaseParams; } if (NumBaseParams < FD->getNumParams() && S.Context.hasSameUnqualifiedType( FD->getParamDecl(NumBaseParams)->getType(), S.Context.getSizeType())) { ++NumBaseParams; HasSizeT = true; } if (NumBaseParams < FD->getNumParams() && FD->getParamDecl(NumBaseParams)->getType()->isAlignValT()) { ++NumBaseParams; HasAlignValT = true; } // In CUDA, determine how much we'd like / dislike to call this. if (S.getLangOpts().CUDA) if (auto *Caller = dyn_cast(S.CurContext)) CUDAPref = S.IdentifyCUDAPreference(Caller, FD); } explicit operator bool() const { return FD; } bool isBetterThan(const UsualDeallocFnInfo &Other, bool WantSize, bool WantAlign) const { // C++ P0722: // A destroying operator delete is preferred over a non-destroying // operator delete. if (Destroying != Other.Destroying) return Destroying; // C++17 [expr.delete]p10: // If the type has new-extended alignment, a function with a parameter // of type std::align_val_t is preferred; otherwise a function without // such a parameter is preferred if (HasAlignValT != Other.HasAlignValT) return HasAlignValT == WantAlign; if (HasSizeT != Other.HasSizeT) return HasSizeT == WantSize; // Use CUDA call preference as a tiebreaker. return CUDAPref > Other.CUDAPref; } DeclAccessPair Found; FunctionDecl *FD; bool Destroying, HasSizeT, HasAlignValT; Sema::CUDAFunctionPreference CUDAPref; }; } /// Determine whether a type has new-extended alignment. This may be called when /// the type is incomplete (for a delete-expression with an incomplete pointee /// type), in which case it will conservatively return false if the alignment is /// not known. static bool hasNewExtendedAlignment(Sema &S, QualType AllocType) { return S.getLangOpts().AlignedAllocation && S.getASTContext().getTypeAlignIfKnown(AllocType) > S.getASTContext().getTargetInfo().getNewAlign(); } /// Select the correct "usual" deallocation function to use from a selection of /// deallocation functions (either global or class-scope). static UsualDeallocFnInfo resolveDeallocationOverload( Sema &S, LookupResult &R, bool WantSize, bool WantAlign, llvm::SmallVectorImpl *BestFns = nullptr) { UsualDeallocFnInfo Best; for (auto I = R.begin(), E = R.end(); I != E; ++I) { UsualDeallocFnInfo Info(S, I.getPair()); if (!Info || !isNonPlacementDeallocationFunction(S, Info.FD) || Info.CUDAPref == Sema::CFP_Never) continue; if (!Best) { Best = Info; if (BestFns) BestFns->push_back(Info); continue; } if (Best.isBetterThan(Info, WantSize, WantAlign)) continue; // If more than one preferred function is found, all non-preferred // functions are eliminated from further consideration. if (BestFns && Info.isBetterThan(Best, WantSize, WantAlign)) BestFns->clear(); Best = Info; if (BestFns) BestFns->push_back(Info); } return Best; } /// Determine whether a given type is a class for which 'delete[]' would call /// a member 'operator delete[]' with a 'size_t' parameter. This implies that /// we need to store the array size (even if the type is /// trivially-destructible). 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; // C++17 [expr.delete]p10: // If the deallocation functions have class scope, the one without a // parameter of type std::size_t is selected. auto Best = resolveDeallocationOverload( S, ops, /*WantSize*/false, /*WantAlign*/hasNewExtendedAlignment(S, allocType)); return Best && Best.HasSizeT; } /// 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) { Optional ArraySize; // 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 (D.getDeclSpec().hasAutoTypeSpec()) 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 && !Initializer) 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()) { // FIXME: GCC permits constant folding here. We should either do so consistently // or not do so at all, rather than changing behavior in C++14 onwards. 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. llvm::APSInt Value(Context.getIntWidth(Context.getSizeType())); Array.NumElts = CheckConvertedConstantExpression(NumElts, Context.getSizeType(), Value, CCEK_ArrayBound) .get(); } else { Array.NumElts = VerifyIntegerConstantExpression( NumElts, nullptr, diag::err_new_array_nonconst, AllowFold) .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.getEndLoc()), UseGlobal, PlacementLParen, PlacementArgs, PlacementRParen, TypeIdParens, AllocType, TInfo, ArraySize, DirectInitRange, Initializer); } 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; } bool Sema::isUnavailableAlignedAllocationFunction(const FunctionDecl &FD) const { if (!getLangOpts().AlignedAllocationUnavailable) return false; if (FD.isDefined()) return false; Optional AlignmentParam; if (FD.isReplaceableGlobalAllocationFunction(&AlignmentParam) && AlignmentParam.hasValue()) return true; return false; } // Emit a diagnostic if an aligned allocation/deallocation function that is not // implemented in the standard library is selected. void Sema::diagnoseUnavailableAlignedAllocation(const FunctionDecl &FD, SourceLocation Loc) { if (isUnavailableAlignedAllocationFunction(FD)) { const llvm::Triple &T = getASTContext().getTargetInfo().getTriple(); StringRef OSName = AvailabilityAttr::getPlatformNameSourceSpelling( getASTContext().getTargetInfo().getPlatformName()); VersionTuple OSVersion = alignedAllocMinVersion(T.getOS()); OverloadedOperatorKind Kind = FD.getDeclName().getCXXOverloadedOperator(); bool IsDelete = Kind == OO_Delete || Kind == OO_Array_Delete; Diag(Loc, diag::err_aligned_allocation_unavailable) << IsDelete << FD.getType().getAsString() << OSName << OSVersion.getAsString() << OSVersion.empty(); Diag(Loc, diag::note_silence_aligned_allocation_unavailable); } } ExprResult Sema::BuildCXXNew(SourceRange Range, bool UseGlobal, SourceLocation PlacementLParen, MultiExprArg PlacementArgs, SourceLocation PlacementRParen, SourceRange TypeIdParens, QualType AllocType, TypeSourceInfo *AllocTypeInfo, Optional ArraySize, SourceRange DirectInitRange, Expr *Initializer) { 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 [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(), Initializer->getBeginLoc(), Initializer->getEndLoc()) : InitializationKind::CreateDirect(TypeRange.getBegin(), DirectInitRange.getBegin(), DirectInitRange.getEnd()); // C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for. auto *Deduced = AllocType->getContainedDeducedType(); if (Deduced && isa(Deduced)) { if (ArraySize) return ExprError( Diag(ArraySize ? (*ArraySize)->getExprLoc() : TypeRange.getBegin(), diag::err_deduced_class_template_compound_type) << /*array*/ 2 << (ArraySize ? (*ArraySize)->getSourceRange() : TypeRange)); InitializedEntity Entity = InitializedEntity::InitializeNew(StartLoc, AllocType); AllocType = DeduceTemplateSpecializationFromInitializer( AllocTypeInfo, Entity, Kind, MultiExprArg(Inits, NumInits)); if (AllocType.isNull()) return ExprError(); } else if (Deduced) { bool Braced = (initStyle == CXXNewExpr::ListInit); if (NumInits == 1) { if (auto p = dyn_cast_or_null(Inits[0])) { Inits = p->getInits(); NumInits = p->getNumInits(); Braced = true; } } if (initStyle == CXXNewExpr::NoInit || NumInits == 0) return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg) << AllocType << TypeRange); if (NumInits > 1) { Expr *FirstBad = Inits[1]; return ExprError(Diag(FirstBad->getBeginLoc(), diag::err_auto_new_ctor_multiple_expressions) << AllocType << TypeRange); } if (Braced && !getLangOpts().CPlusPlus17) Diag(Initializer->getBeginLoc(), diag::ext_auto_new_list_init) << 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(); // 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 && (*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. llvm::Optional KnownArraySize; if (ArraySize && *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, // per CWG1464. Otherwise, if it's not a constant, we must have an // unparenthesized array type. if (!(*ArraySize)->isValueDependent()) { // We've already performed any required implicit conversion to integer or // unscoped enumeration type. // FIXME: Per CWG1464, we are required to check the value prior to // converting to size_t. This will never find a negative array size in // C++14 onwards, because Value is always unsigned here! if (Optional Value = (*ArraySize)->getIntegerConstantExpr(Context)) { if (Value->isSigned() && Value->isNegative()) { return ExprError(Diag((*ArraySize)->getBeginLoc(), diag::err_typecheck_negative_array_size) << (*ArraySize)->getSourceRange()); } if (!AllocType->isDependentType()) { unsigned ActiveSizeBits = ConstantArrayType::getNumAddressingBits( Context, AllocType, *Value); if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) return ExprError( Diag((*ArraySize)->getBeginLoc(), diag::err_array_too_large) << Value->toString(10) << (*ArraySize)->getSourceRange()); } KnownArraySize = Value->getZExtValue(); } else if (TypeIdParens.isValid()) { // Can't have dynamic array size when the type-id is in parentheses. Diag((*ArraySize)->getBeginLoc(), 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; unsigned Alignment = AllocType->isDependentType() ? 0 : Context.getTypeAlign(AllocType); unsigned NewAlignment = Context.getTargetInfo().getNewAlign(); bool PassAlignment = getLangOpts().AlignedAllocation && Alignment > NewAlignment; AllocationFunctionScope Scope = UseGlobal ? AFS_Global : AFS_Both; if (!AllocType->isDependentType() && !Expr::hasAnyTypeDependentArguments(PlacementArgs) && FindAllocationFunctions( StartLoc, SourceRange(PlacementLParen, PlacementRParen), Scope, Scope, AllocType, ArraySize.hasValue(), PassAlignment, 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) { auto *Proto = OperatorNew->getType()->castAs(); 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. Skip the second parameter too if we're passing in the // alignment; we've already filled it in. unsigned NumImplicitArgs = PassAlignment ? 2 : 1; if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto, NumImplicitArgs, PlacementArgs, AllPlaceArgs, CallType)) return ExprError(); if (!AllPlaceArgs.empty()) PlacementArgs = AllPlaceArgs; // We would like to perform some checking on the given `operator new` call, // but the PlacementArgs does not contain the implicit arguments, // namely allocation size and maybe allocation alignment, // so we need to conjure them. QualType SizeTy = Context.getSizeType(); unsigned SizeTyWidth = Context.getTypeSize(SizeTy); llvm::APInt SingleEltSize( SizeTyWidth, Context.getTypeSizeInChars(AllocType).getQuantity()); // How many bytes do we want to allocate here? llvm::Optional AllocationSize; if (!ArraySize.hasValue() && !AllocType->isDependentType()) { // For non-array operator new, we only want to allocate one element. AllocationSize = SingleEltSize; } else if (KnownArraySize.hasValue() && !AllocType->isDependentType()) { // For array operator new, only deal with static array size case. bool Overflow; AllocationSize = llvm::APInt(SizeTyWidth, *KnownArraySize) .umul_ov(SingleEltSize, Overflow); (void)Overflow; assert( !Overflow && "Expected that all the overflows would have been handled already."); } IntegerLiteral AllocationSizeLiteral( Context, AllocationSize.getValueOr(llvm::APInt::getNullValue(SizeTyWidth)), SizeTy, SourceLocation()); // Otherwise, if we failed to constant-fold the allocation size, we'll // just give up and pass-in something opaque, that isn't a null pointer. OpaqueValueExpr OpaqueAllocationSize(SourceLocation(), SizeTy, VK_RValue, OK_Ordinary, /*SourceExpr=*/nullptr); // Let's synthesize the alignment argument in case we will need it. // Since we *really* want to allocate these on stack, this is slightly ugly // because there might not be a `std::align_val_t` type. EnumDecl *StdAlignValT = getStdAlignValT(); QualType AlignValT = StdAlignValT ? Context.getTypeDeclType(StdAlignValT) : SizeTy; IntegerLiteral AlignmentLiteral( Context, llvm::APInt(Context.getTypeSize(SizeTy), Alignment / Context.getCharWidth()), SizeTy, SourceLocation()); ImplicitCastExpr DesiredAlignment(ImplicitCastExpr::OnStack, AlignValT, CK_IntegralCast, &AlignmentLiteral, VK_RValue, FPOptionsOverride()); // Adjust placement args by prepending conjured size and alignment exprs. llvm::SmallVector CallArgs; CallArgs.reserve(NumImplicitArgs + PlacementArgs.size()); CallArgs.emplace_back(AllocationSize.hasValue() ? static_cast(&AllocationSizeLiteral) : &OpaqueAllocationSize); if (PassAlignment) CallArgs.emplace_back(&DesiredAlignment); CallArgs.insert(CallArgs.end(), PlacementArgs.begin(), PlacementArgs.end()); DiagnoseSentinelCalls(OperatorNew, PlacementLParen, CallArgs); checkCall(OperatorNew, Proto, /*ThisArg=*/nullptr, CallArgs, /*IsMemberFunction=*/false, StartLoc, Range, CallType); // Warn if the type is over-aligned and is being allocated by (unaligned) // global operator new. if (PlacementArgs.empty() && !PassAlignment && (OperatorNew->isImplicit() || (OperatorNew->getBeginLoc().isValid() && getSourceManager().isInSystemHeader(OperatorNew->getBeginLoc())))) { if (Alignment > NewAlignment) Diag(StartLoc, diag::warn_overaligned_type) << AllocType << unsigned(Alignment / Context.getCharWidth()) << unsigned(NewAlignment / Context.getCharWidth()); } } // 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 (ArraySize && !isLegalArrayNewInitializer(initStyle, Initializer)) { SourceRange InitRange(Inits[0]->getBeginLoc(), Inits[NumInits - 1]->getEndLoc()); Diag(StartLoc, diag::err_new_array_init_args) << InitRange; return ExprError(); } // 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))) { // The type we initialize is the complete type, including the array bound. QualType InitType; if (KnownArraySize) InitType = Context.getConstantArrayType( AllocType, llvm::APInt(Context.getTypeSize(Context.getSizeType()), *KnownArraySize), *ArraySize, ArrayType::Normal, 0); else if (ArraySize) InitType = Context.getIncompleteArrayType(AllocType, ArrayType::Normal, 0); else InitType = AllocType; 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. // FIXME: We should not create these in the first place. if (CXXBindTemporaryExpr *Binder = dyn_cast_or_null(FullInit.get())) FullInit = Binder->getSubExpr(); Initializer = FullInit.get(); // FIXME: If we have a KnownArraySize, check that the array bound of the // initializer is no greater than that constant value. if (ArraySize && !*ArraySize) { auto *CAT = Context.getAsConstantArrayType(Initializer->getType()); if (CAT) { // FIXME: Track that the array size was inferred rather than explicitly // specified. ArraySize = IntegerLiteral::Create( Context, CAT->getSize(), Context.getSizeType(), TypeRange.getEnd()); } else { Diag(TypeRange.getEnd(), diag::err_new_array_size_unknown_from_init) << Initializer->getSourceRange(); } } } // 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); } return CXXNewExpr::Create(Context, UseGlobal, OperatorNew, OperatorDelete, PassAlignment, UsualArrayDeleteWantsSize, PlacementArgs, TypeIdParens, ArraySize, initStyle, Initializer, ResultType, AllocTypeInfo, Range, DirectInitRange); } /// 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() && RequireCompleteSizedType( Loc, AllocType, diag::err_new_incomplete_or_sizeless_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 (AllocType.getAddressSpace() != LangAS::Default && !getLangOpts().OpenCLCPlusPlus) return Diag(Loc, diag::err_address_space_qualified_new) << AllocType.getUnqualifiedType() << AllocType.getQualifiers().getAddressSpaceAttributePrintValue(); 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; } static bool resolveAllocationOverload( Sema &S, LookupResult &R, SourceRange Range, SmallVectorImpl &Args, bool &PassAlignment, FunctionDecl *&Operator, OverloadCandidateSet *AlignedCandidates, Expr *AlignArg, bool Diagnose) { OverloadCandidateSet Candidates(R.getNameLoc(), 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)) { S.AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(), /*ExplicitTemplateArgs=*/nullptr, Args, Candidates, /*SuppressUserConversions=*/false); continue; } FunctionDecl *Fn = cast(D); S.AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates, /*SuppressUserConversions=*/false); } // Do the resolution. OverloadCandidateSet::iterator Best; switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) { case OR_Success: { // Got one! FunctionDecl *FnDecl = Best->Function; if (S.CheckAllocationAccess(R.getNameLoc(), Range, R.getNamingClass(), Best->FoundDecl) == Sema::AR_inaccessible) return true; Operator = FnDecl; return false; } case OR_No_Viable_Function: // C++17 [expr.new]p13: // If no matching function is found and the allocated object type has // new-extended alignment, the alignment argument is removed from the // argument list, and overload resolution is performed again. if (PassAlignment) { PassAlignment = false; AlignArg = Args[1]; Args.erase(Args.begin() + 1); return resolveAllocationOverload(S, R, Range, Args, PassAlignment, Operator, &Candidates, AlignArg, Diagnose); } // 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. // FIXME: Find out how this interacts with the std::align_val_t fallback // once MSVC implements it. if (R.getLookupName().getCXXOverloadedOperator() == OO_Array_New && S.Context.getLangOpts().MSVCCompat) { R.clear(); R.setLookupName(S.Context.DeclarationNames.getCXXOperatorName(OO_New)); S.LookupQualifiedName(R, S.Context.getTranslationUnitDecl()); // FIXME: This will give bad diagnostics pointing at the wrong functions. return resolveAllocationOverload(S, R, Range, Args, PassAlignment, Operator, /*Candidates=*/nullptr, /*AlignArg=*/nullptr, Diagnose); } if (Diagnose) { // If this is an allocation of the form 'new (p) X' for some object // pointer p (or an expression that will decay to such a pointer), // diagnose the missing inclusion of . if (!R.isClassLookup() && Args.size() == 2 && (Args[1]->getType()->isObjectPointerType() || Args[1]->getType()->isArrayType())) { S.Diag(R.getNameLoc(), diag::err_need_header_before_placement_new) << R.getLookupName() << Range; // Listing the candidates is unlikely to be useful; skip it. return true; } // Finish checking all candidates before we note any. This checking can // produce additional diagnostics so can't be interleaved with our // emission of notes. // // For an aligned allocation, separately check the aligned and unaligned // candidates with their respective argument lists. SmallVector Cands; SmallVector AlignedCands; llvm::SmallVector AlignedArgs; if (AlignedCandidates) { auto IsAligned = [](OverloadCandidate &C) { return C.Function->getNumParams() > 1 && C.Function->getParamDecl(1)->getType()->isAlignValT(); }; auto IsUnaligned = [&](OverloadCandidate &C) { return !IsAligned(C); }; AlignedArgs.reserve(Args.size() + 1); AlignedArgs.push_back(Args[0]); AlignedArgs.push_back(AlignArg); AlignedArgs.append(Args.begin() + 1, Args.end()); AlignedCands = AlignedCandidates->CompleteCandidates( S, OCD_AllCandidates, AlignedArgs, R.getNameLoc(), IsAligned); Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args, R.getNameLoc(), IsUnaligned); } else { Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args, R.getNameLoc()); } S.Diag(R.getNameLoc(), diag::err_ovl_no_viable_function_in_call) << R.getLookupName() << Range; if (AlignedCandidates) AlignedCandidates->NoteCandidates(S, AlignedArgs, AlignedCands, "", R.getNameLoc()); Candidates.NoteCandidates(S, Args, Cands, "", R.getNameLoc()); } return true; case OR_Ambiguous: if (Diagnose) { Candidates.NoteCandidates( PartialDiagnosticAt(R.getNameLoc(), S.PDiag(diag::err_ovl_ambiguous_call) << R.getLookupName() << Range), S, OCD_AmbiguousCandidates, Args); } return true; case OR_Deleted: { if (Diagnose) { Candidates.NoteCandidates( PartialDiagnosticAt(R.getNameLoc(), S.PDiag(diag::err_ovl_deleted_call) << R.getLookupName() << Range), S, OCD_AllCandidates, Args); } return true; } } llvm_unreachable("Unreachable, bad result from BestViableFunction"); } bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range, AllocationFunctionScope NewScope, AllocationFunctionScope DeleteScope, QualType AllocType, bool IsArray, bool &PassAlignment, MultiExprArg PlaceArgs, FunctionDecl *&OperatorNew, FunctionDecl *&OperatorDelete, bool Diagnose) { // --- Choosing an allocation function --- // C++ 5.3.4p8 - 14 & 18 // 1) If looking in AFS_Global scope for allocation functions, only look in // the global scope. Else, if AFS_Class, only look in the scope of the // allocated class. If AFS_Both, look in both. // 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; AllocArgs.reserve((PassAlignment ? 2 : 1) + PlaceArgs.size()); // We don't care about the actual value of these arguments. // FIXME: Should the Sema create the expression and embed it in the syntax // tree? Or should the consumer just recalculate the value? // FIXME: Using a dummy value will interact poorly with attribute enable_if. IntegerLiteral Size(Context, llvm::APInt::getNullValue( Context.getTargetInfo().getPointerWidth(0)), Context.getSizeType(), SourceLocation()); AllocArgs.push_back(&Size); QualType AlignValT = Context.VoidTy; if (PassAlignment) { DeclareGlobalNewDelete(); AlignValT = Context.getTypeDeclType(getStdAlignValT()); } CXXScalarValueInitExpr Align(AlignValT, nullptr, SourceLocation()); if (PassAlignment) AllocArgs.push_back(&Align); AllocArgs.insert(AllocArgs.end(), PlaceArgs.begin(), PlaceArgs.end()); // 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); QualType AllocElemType = Context.getBaseElementType(AllocType); // Find the allocation function. { LookupResult R(*this, NewName, StartLoc, LookupOrdinaryName); // C++1z [expr.new]p9: // If the new-expression begins with a unary :: operator, the allocation // function's name is looked up in the global scope. Otherwise, if the // allocated type is a class type T or array thereof, the allocation // function's name is looked up in the scope of T. if (AllocElemType->isRecordType() && NewScope != AFS_Global) LookupQualifiedName(R, AllocElemType->getAsCXXRecordDecl()); // We can see ambiguity here if the allocation function is found in // multiple base classes. if (R.isAmbiguous()) return true; // If this lookup fails to find the name, or if the allocated type is not // a class type, the allocation function's name is looked up in the // global scope. if (R.empty()) { if (NewScope == AFS_Class) return true; LookupQualifiedName(R, Context.getTranslationUnitDecl()); } if (getLangOpts().OpenCLCPlusPlus && R.empty()) { if (PlaceArgs.empty()) { Diag(StartLoc, diag::err_openclcxx_not_supported) << "default new"; } else { Diag(StartLoc, diag::err_openclcxx_placement_new); } return true; } assert(!R.empty() && "implicitly declared allocation functions not found"); assert(!R.isAmbiguous() && "global allocation functions are ambiguous"); // We do our own custom access checks below. R.suppressDiagnostics(); if (resolveAllocationOverload(*this, R, Range, AllocArgs, PassAlignment, OperatorNew, /*Candidates=*/nullptr, /*AlignArg=*/nullptr, Diagnose)) return true; } // We don't need an operator delete if we're running under -fno-exceptions. if (!getLangOpts().Exceptions) { OperatorDelete = nullptr; return false; } // Note, the name of OperatorNew might have been changed from array to // non-array by resolveAllocationOverload. DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( OperatorNew->getDeclName().getCXXOverloadedOperator() == OO_Array_New ? OO_Array_Delete : OO_Delete); // 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() && DeleteScope != AFS_Global) { auto *RD = cast(AllocElemType->castAs()->getDecl()); LookupQualifiedName(FoundDelete, RD); } if (FoundDelete.isAmbiguous()) return true; // FIXME: clean up expressions? // Filter out any destroying operator deletes. We can't possibly call such a // function in this context, because we're handling the case where the object // was not successfully constructed. // FIXME: This is not covered by the language rules yet. { LookupResult::Filter Filter = FoundDelete.makeFilter(); while (Filter.hasNext()) { auto *FD = dyn_cast(Filter.next()->getUnderlyingDecl()); if (FD && FD->isDestroyingOperatorDelete()) Filter.erase(); } Filter.done(); } bool FoundGlobalDelete = FoundDelete.empty(); if (FoundDelete.empty()) { FoundDelete.clear(LookupOrdinaryName); if (DeleteScope == AFS_Class) return true; 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() // // We don't have any definition for what a "placement allocation function" // is, but we assume it's any allocation function whose // parameter-declaration-clause is anything other than (size_t). // // FIXME: Should (size_t, std::align_val_t) also be considered non-placement? // This affects whether an exception from the constructor of an overaligned // type uses the sized or non-sized form of aligned operator delete. bool isPlacementNew = !PlaceArgs.empty() || OperatorNew->param_size() != 1 || OperatorNew->isVariadic(); 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. QualType ExpectedFunctionType; { auto *Proto = OperatorNew->getType()->castAs(); 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; // FIXME: This is not part of the standard's rule. 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(adjustCCAndNoReturn(Fn->getType(), ExpectedFunctionType, /*AdjustExcpetionSpec*/true), ExpectedFunctionType)) Matches.push_back(std::make_pair(D.getPair(), Fn)); } if (getLangOpts().CUDA) EraseUnwantedCUDAMatches(dyn_cast(CurContext), Matches); } else { // C++1y [expr.new]p22: // For a non-placement allocation function, the normal deallocation // function lookup is used // // Per [expr.delete]p10, this lookup prefers a member operator delete // without a size_t argument, but prefers a non-member operator delete // with a size_t where possible (which it always is in this case). llvm::SmallVector BestDeallocFns; UsualDeallocFnInfo Selected = resolveDeallocationOverload( *this, FoundDelete, /*WantSize*/ FoundGlobalDelete, /*WantAlign*/ hasNewExtendedAlignment(*this, AllocElemType), &BestDeallocFns); if (Selected) Matches.push_back(std::make_pair(Selected.Found, Selected.FD)); else { // If we failed to select an operator, all remaining functions are viable // but ambiguous. for (auto Fn : BestDeallocFns) Matches.push_back(std::make_pair(Fn.Found, Fn.FD)); } } // 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++1z [expr.new]p23: // If the lookup finds a usual deallocation function (3.7.4.2) // with a parameter of type std::size_t 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 (getLangOpts().CPlusPlus11 && isPlacementNew && isNonPlacementDeallocationFunction(*this, OperatorDelete)) { UsualDeallocFnInfo Info(*this, DeclAccessPair::make(OperatorDelete, AS_public)); // Core issue, per mail to core reflector, 2016-10-09: // If this is a member operator delete, and there is a corresponding // non-sized member operator delete, this isn't /really/ a sized // deallocation function, it just happens to have a size_t parameter. bool IsSizedDelete = Info.HasSizeT; if (IsSizedDelete && !FoundGlobalDelete) { auto NonSizedDelete = resolveDeallocationOverload(*this, FoundDelete, /*WantSize*/false, /*WantAlign*/Info.HasAlignValT); if (NonSizedDelete && !NonSizedDelete.HasSizeT && NonSizedDelete.HasAlignValT == Info.HasAlignValT) IsSizedDelete = false; } if (IsSizedDelete) { SourceRange R = PlaceArgs.empty() ? SourceRange() : SourceRange(PlaceArgs.front()->getBeginLoc(), PlaceArgs.back()->getEndLoc()); Diag(StartLoc, diag::err_placement_new_non_placement_delete) << R; if (!OperatorDelete->isImplicit()) Diag(OperatorDelete->getLocation(), diag::note_previous_decl) << DeleteName; } } CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(), Matches[0].first); } else if (!Matches.empty()) { // We found multiple suitable operators. Per [expr.new]p20, that means we // call no 'operator delete' function, but we should at least warn the user. // FIXME: Suppress this warning if the construction cannot throw. Diag(StartLoc, diag::warn_ambiguous_suitable_delete_function_found) << DeleteName << AllocElemType; for (auto &Match : Matches) Diag(Match.second->getLocation(), diag::note_member_declared_here) << DeleteName; } return false; } /// 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; // The implicitly declared new and delete operators // are not supported in OpenCL. if (getLangOpts().OpenCLCPlusPlus) 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); } if (!StdAlignValT && getLangOpts().AlignedAllocation) { // The "std::align_val_t" enum class has not yet been declared, so build it // implicitly. auto *AlignValT = EnumDecl::Create( Context, getOrCreateStdNamespace(), SourceLocation(), SourceLocation(), &PP.getIdentifierTable().get("align_val_t"), nullptr, true, true, true); AlignValT->setIntegerType(Context.getSizeType()); AlignValT->setPromotionType(Context.getSizeType()); AlignValT->setImplicit(true); StdAlignValT = AlignValT; } GlobalNewDeleteDeclared = true; QualType VoidPtr = Context.getPointerType(Context.VoidTy); QualType SizeT = Context.getSizeType(); auto DeclareGlobalAllocationFunctions = [&](OverloadedOperatorKind Kind, QualType Return, QualType Param) { llvm::SmallVector Params; Params.push_back(Param); // Create up to four variants of the function (sized/aligned). bool HasSizedVariant = getLangOpts().SizedDeallocation && (Kind == OO_Delete || Kind == OO_Array_Delete); bool HasAlignedVariant = getLangOpts().AlignedAllocation; int NumSizeVariants = (HasSizedVariant ? 2 : 1); int NumAlignVariants = (HasAlignedVariant ? 2 : 1); for (int Sized = 0; Sized < NumSizeVariants; ++Sized) { if (Sized) Params.push_back(SizeT); for (int Aligned = 0; Aligned < NumAlignVariants; ++Aligned) { if (Aligned) Params.push_back(Context.getTypeDeclType(getStdAlignValT())); DeclareGlobalAllocationFunction( Context.DeclarationNames.getCXXOperatorName(Kind), Return, Params); if (Aligned) Params.pop_back(); } } }; DeclareGlobalAllocationFunctions(OO_New, VoidPtr, SizeT); DeclareGlobalAllocationFunctions(OO_Array_New, VoidPtr, SizeT); DeclareGlobalAllocationFunctions(OO_Delete, Context.VoidTy, VoidPtr); DeclareGlobalAllocationFunctions(OO_Array_Delete, Context.VoidTy, VoidPtr); } /// DeclareGlobalAllocationFunction - Declares a single implicit global /// allocation function if it doesn't already exist. void Sema::DeclareGlobalAllocationFunction(DeclarationName Name, QualType Return, ArrayRef Params) { DeclContext *GlobalCtx = Context.getTranslationUnitDecl(); // 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() == Params.size()) { llvm::SmallVector FuncParams; for (auto *P : Func->parameters()) FuncParams.push_back( Context.getCanonicalType(P->getType().getUnqualifiedType())); if (llvm::makeArrayRef(FuncParams) == Params) { // 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->setVisibleDespiteOwningModule(); return; } } } } FunctionProtoType::ExtProtoInfo EPI(Context.getDefaultCallingConvention( /*IsVariadic=*/false, /*IsCXXMethod=*/false, /*IsBuiltin=*/true)); 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; } auto CreateAllocationFunctionDecl = [&](Attr *ExtraAttr) { QualType FnType = Context.getFunctionType(Return, Params, EPI); FunctionDecl *Alloc = FunctionDecl::Create( Context, GlobalCtx, SourceLocation(), SourceLocation(), Name, FnType, /*TInfo=*/nullptr, SC_None, false, true); Alloc->setImplicit(); // Global allocation functions should always be visible. Alloc->setVisibleDespiteOwningModule(); Alloc->addAttr(VisibilityAttr::CreateImplicit( Context, LangOpts.GlobalAllocationFunctionVisibilityHidden ? VisibilityAttr::Hidden : VisibilityAttr::Default)); llvm::SmallVector ParamDecls; for (QualType T : Params) { ParamDecls.push_back(ParmVarDecl::Create( Context, Alloc, SourceLocation(), SourceLocation(), nullptr, T, /*TInfo=*/nullptr, SC_None, nullptr)); ParamDecls.back()->setImplicit(); } Alloc->setParams(ParamDecls); if (ExtraAttr) Alloc->addAttr(ExtraAttr); AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction(Alloc); Context.getTranslationUnitDecl()->addDecl(Alloc); IdResolver.tryAddTopLevelDecl(Alloc, Name); }; if (!LangOpts.CUDA) CreateAllocationFunctionDecl(nullptr); else { // Host and device get their own declaration so each can be // defined or re-declared independently. CreateAllocationFunctionDecl(CUDAHostAttr::CreateImplicit(Context)); CreateAllocationFunctionDecl(CUDADeviceAttr::CreateImplicit(Context)); } } FunctionDecl *Sema::FindUsualDeallocationFunction(SourceLocation StartLoc, bool CanProvideSize, bool Overaligned, DeclarationName Name) { DeclareGlobalNewDelete(); LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName); LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl()); // FIXME: It's possible for this to result in ambiguity, through a // user-declared variadic operator delete or the enable_if attribute. We // should probably not consider those cases to be usual deallocation // functions. But for now we just make an arbitrary choice in that case. auto Result = resolveDeallocationOverload(*this, FoundDelete, CanProvideSize, Overaligned); assert(Result.FD && "operator delete missing from global scope?"); return Result.FD; } FunctionDecl *Sema::FindDeallocationFunctionForDestructor(SourceLocation Loc, CXXRecordDecl *RD) { DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Delete); FunctionDecl *OperatorDelete = nullptr; if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete)) return nullptr; if (OperatorDelete) return OperatorDelete; // If there's no class-specific operator delete, look up the global // non-array delete. return FindUsualDeallocationFunction( Loc, true, hasNewExtendedAlignment(*this, Context.getRecordType(RD)), Name); } 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(); bool Overaligned = hasNewExtendedAlignment(*this, Context.getRecordType(RD)); // C++17 [expr.delete]p10: // If the deallocation functions have class scope, the one without a // parameter of type std::size_t is selected. llvm::SmallVector Matches; resolveDeallocationOverload(*this, Found, /*WantSize*/ false, /*WantAlign*/ Overaligned, &Matches); // If we could find an overload, use it. if (Matches.size() == 1) { Operator = cast(Matches[0].FD); // FIXME: DiagnoseUseOfDecl? if (Operator->isDeleted()) { if (Diagnose) { Diag(StartLoc, diag::err_deleted_function_use); NoteDeletedFunction(Operator); } return true; } if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(), Matches[0].Found, Diagnose) == AR_inaccessible) return true; return false; } // We found multiple suitable operators; complain about the ambiguity. // FIXME: The standard doesn't say to do this; it appears that the intent // is that this should never happen. if (!Matches.empty()) { if (Diagnose) { Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found) << Name << RD; for (auto &Match : Matches) Diag(Match.FD->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 (NamedDecl *D : Found) Diag(D->getUnderlyingDecl()->getLocation(), diag::note_member_declared_here) << Name; } return true; } Operator = nullptr; return false; } namespace { /// 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) : Field(nullptr), IsArrayForm(false), EndOfTU(EndOfTU), HasUndefinedConstructors(false) {} /// 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); /// 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); FieldDecl *Field; /// List of mismatching new-expressions used for initialization of the pointee llvm::SmallVector NewExprs; /// Indicates whether delete-expression was in array form. bool IsArrayForm; private: const bool EndOfTU; /// Indicates that there is at least one constructor without body. bool HasUndefinedConstructors; /// 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); /// 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); /// 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); /// 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); /// 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->getBeginLoc(), Detector); break; } case MismatchingNewDeleteDetector::AnalyzeLater: { DeleteExprs[Detector.Field].push_back( std::make_pair(DE->getBeginLoc(), 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->castAs()->getPointeeType(); QualType PointeeElem = Context.getBaseElementType(Pointee); if (Pointee.getAddressSpace() != LangAS::Default && !getLangOpts().OpenCLCPlusPlus) return Diag(Ex.get()->getBeginLoc(), diag::err_address_space_qualified_delete) << Pointee.getUnqualifiedType() << Pointee.getQualifiers().getAddressSpaceAttributePrintValue(); 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() || Pointee->isSizelessType()) { 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 = UsualDeallocFnInfo(*this, DeclAccessPair::make(OperatorDelete, AS_public)) .HasSizeT; } 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) { if (getLangOpts().OpenCLCPlusPlus) { Diag(StartLoc, diag::err_openclcxx_not_supported) << "default delete"; return ExprError(); } bool IsComplete = isCompleteType(StartLoc, Pointee); bool CanProvideSize = IsComplete && (!ArrayForm || UsualArrayDeleteWantsSize || Pointee.isDestructedType()); bool Overaligned = hasNewExtendedAlignment(*this, Pointee); // Look for a global declaration. OperatorDelete = FindUsualDeallocationFunction(StartLoc, CanProvideSize, Overaligned, DeleteName); } MarkFunctionReferenced(StartLoc, OperatorDelete); // Check access and ambiguity of destructor if we're going to call it. // Note that this is required even for a virtual delete. bool IsVirtualDelete = false; if (PointeeRD) { if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor, PDiag(diag::err_access_dtor) << PointeeElem); IsVirtualDelete = Dtor->isVirtual(); } } DiagnoseUseOfDecl(OperatorDelete, StartLoc); // Convert the operand to the type of the first parameter of operator // delete. This is only necessary if we selected a destroying operator // delete that we are going to call (non-virtually); converting to void* // is trivial and left to AST consumers to handle. QualType ParamType = OperatorDelete->getParamDecl(0)->getType(); if (!IsVirtualDelete && !ParamType->getPointeeType()->isVoidType()) { Qualifiers Qs = Pointee.getQualifiers(); if (Qs.hasCVRQualifiers()) { // Qualifiers are irrelevant to this conversion; we're only looking // for access and ambiguity. Qs.removeCVRQualifiers(); QualType Unqual = Context.getPointerType( Context.getQualifiedType(Pointee.getUnqualifiedType(), Qs)); Ex = ImpCastExprToType(Ex.get(), Unqual, CK_NoOp); } Ex = PerformImplicitConversion(Ex.get(), ParamType, AA_Passing); if (Ex.isInvalid()) return ExprError(); } } CXXDeleteExpr *Result = new (Context) CXXDeleteExpr( Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten, UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc); AnalyzeDeleteExprMismatch(Result); return Result; } static bool resolveBuiltinNewDeleteOverload(Sema &S, CallExpr *TheCall, bool IsDelete, FunctionDecl *&Operator) { DeclarationName NewName = S.Context.DeclarationNames.getCXXOperatorName( IsDelete ? OO_Delete : OO_New); LookupResult R(S, NewName, TheCall->getBeginLoc(), Sema::LookupOrdinaryName); S.LookupQualifiedName(R, S.Context.getTranslationUnitDecl()); assert(!R.empty() && "implicitly declared allocation functions not found"); assert(!R.isAmbiguous() && "global allocation functions are ambiguous"); // We do our own custom access checks below. R.suppressDiagnostics(); SmallVector Args(TheCall->arg_begin(), TheCall->arg_end()); OverloadCandidateSet Candidates(R.getNameLoc(), OverloadCandidateSet::CSK_Normal); for (LookupResult::iterator FnOvl = R.begin(), FnOvlEnd = R.end(); FnOvl != FnOvlEnd; ++FnOvl) { // Even member operator new/delete are implicitly treated as // static, so don't use AddMemberCandidate. NamedDecl *D = (*FnOvl)->getUnderlyingDecl(); if (FunctionTemplateDecl *FnTemplate = dyn_cast(D)) { S.AddTemplateOverloadCandidate(FnTemplate, FnOvl.getPair(), /*ExplicitTemplateArgs=*/nullptr, Args, Candidates, /*SuppressUserConversions=*/false); continue; } FunctionDecl *Fn = cast(D); S.AddOverloadCandidate(Fn, FnOvl.getPair(), Args, Candidates, /*SuppressUserConversions=*/false); } SourceRange Range = TheCall->getSourceRange(); // Do the resolution. OverloadCandidateSet::iterator Best; switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) { case OR_Success: { // Got one! FunctionDecl *FnDecl = Best->Function; assert(R.getNamingClass() == nullptr && "class members should not be considered"); if (!FnDecl->isReplaceableGlobalAllocationFunction()) { S.Diag(R.getNameLoc(), diag::err_builtin_operator_new_delete_not_usual) << (IsDelete ? 1 : 0) << Range; S.Diag(FnDecl->getLocation(), diag::note_non_usual_function_declared_here) << R.getLookupName() << FnDecl->getSourceRange(); return true; } Operator = FnDecl; return false; } case OR_No_Viable_Function: Candidates.NoteCandidates( PartialDiagnosticAt(R.getNameLoc(), S.PDiag(diag::err_ovl_no_viable_function_in_call) << R.getLookupName() << Range), S, OCD_AllCandidates, Args); return true; case OR_Ambiguous: Candidates.NoteCandidates( PartialDiagnosticAt(R.getNameLoc(), S.PDiag(diag::err_ovl_ambiguous_call) << R.getLookupName() << Range), S, OCD_AmbiguousCandidates, Args); return true; case OR_Deleted: { Candidates.NoteCandidates( PartialDiagnosticAt(R.getNameLoc(), S.PDiag(diag::err_ovl_deleted_call) << R.getLookupName() << Range), S, OCD_AllCandidates, Args); return true; } } llvm_unreachable("Unreachable, bad result from BestViableFunction"); } ExprResult Sema::SemaBuiltinOperatorNewDeleteOverloaded(ExprResult TheCallResult, bool IsDelete) { CallExpr *TheCall = cast(TheCallResult.get()); if (!getLangOpts().CPlusPlus) { Diag(TheCall->getExprLoc(), diag::err_builtin_requires_language) << (IsDelete ? "__builtin_operator_delete" : "__builtin_operator_new") << "C++"; return ExprError(); } // CodeGen assumes it can find the global new and delete to call, // so ensure that they are declared. DeclareGlobalNewDelete(); FunctionDecl *OperatorNewOrDelete = nullptr; if (resolveBuiltinNewDeleteOverload(*this, TheCall, IsDelete, OperatorNewOrDelete)) return ExprError(); assert(OperatorNewOrDelete && "should be found"); DiagnoseUseOfDecl(OperatorNewOrDelete, TheCall->getExprLoc()); MarkFunctionReferenced(TheCall->getExprLoc(), OperatorNewOrDelete); TheCall->setType(OperatorNewOrDelete->getReturnType()); for (unsigned i = 0; i != TheCall->getNumArgs(); ++i) { QualType ParamTy = OperatorNewOrDelete->getParamDecl(i)->getType(); InitializedEntity Entity = InitializedEntity::InitializeParameter(Context, ParamTy, false); ExprResult Arg = PerformCopyInitialization( Entity, TheCall->getArg(i)->getBeginLoc(), TheCall->getArg(i)); if (Arg.isInvalid()) return ExprError(); TheCall->setArg(i, Arg.get()); } auto Callee = dyn_cast(TheCall->getCallee()); assert(Callee && Callee->getCastKind() == CK_BuiltinFnToFnPtr && "Callee expected to be implicit cast to a builtin function pointer"); Callee->setType(OperatorNewOrDelete->getType()); return TheCallResult; } void Sema::CheckVirtualDtorCall(CXXDestructorDecl *dtor, SourceLocation Loc, bool IsDelete, bool CallCanBeVirtual, bool WarnOnNonAbstractTypes, SourceLocation DtorLoc) { if (!dtor || dtor->isVirtual() || !CallCanBeVirtual || isUnevaluatedContext()) 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; // If the superclass is in a system header, there's nothing that can be done. // The `delete` (where we emit the warning) can be in a system header, // what matters for this warning is where the deleted type is defined. if (getSourceManager().isInSystemHeader(PointeeRD->getLocation())) return; QualType ClassType = dtor->getThisType()->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); } /// 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 = BuildDeclRefExpr( ConditionVar, ConditionVar->getType().getNonReferenceType(), VK_LValue, ConditionVar->getLocation()); 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, Ty, 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(), S.CurFPFeatureOverrides()); 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) { // C++ [over.match.oper]p7: [...] operands of class type are converted [...] if (CCK == CCK_ForBuiltinOverloadedOp && !From->getType()->isRecordType()) return From; 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->getBeginLoc(), ToType.getNonReferenceType(), CastKind, cast(FD), ICS.UserDefined.FoundConversionFunction, ICS.UserDefined.HadMultipleCandidates, From); if (CastArg.isInvalid()) return ExprError(); From = CastArg.get(); // C++ [over.match.oper]p7: // [...] the second standard conversion sequence of a user-defined // conversion sequence is not applied. if (CCK == CCK_ForBuiltinOverloadedOp) return From; 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: Sema::AssignConvertType ConvTy = CheckAssignmentConstraints(From->getExprLoc(), ToType, From->getType()); bool Diagnosed = DiagnoseAssignmentResult( ConvTy == Compatible ? Incompatible : ConvTy, From->getExprLoc(), ToType, From->getType(), From, Action); assert(Diagnosed && "failed to diagnose bad conversion"); (void)Diagnosed; 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), ToType, 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->getBeginLoc())) 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, FPOptionsOverride()); } 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_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()->castAs()->getElementType(); QualType ToEl = ToType->castAs()->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, From->getValueKind(), /*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->getBeginLoc(), diag::ext_typecheck_convert_incompatible_pointer) << ToType << From->getType() << Action << From->getSourceRange() << 0; else Diag(From->getBeginLoc(), diag::ext_typecheck_convert_incompatible_pointer) << From->getType() << ToType << Action << From->getSourceRange() << 0; if (From->getType()->isObjCObjectPointerType() && ToType->isObjCObjectPointerType()) EmitRelatedResultTypeNote(From); } else if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers() && !CheckObjCARCUnavailableWeakConversion(ToType, From->getType())) { if (Action == AA_Initializing) Diag(From->getBeginLoc(), diag::err_arc_weak_unavailable_assign); else Diag(From->getBeginLoc(), diag::err_arc_convesion_of_weak_unavailable) << (Action == AA_Casting) << From->getType() << ToType << From->getSourceRange(); } // Defer address space conversion to the third conversion. QualType FromPteeType = From->getType()->getPointeeType(); QualType ToPteeType = ToType->getPointeeType(); QualType NewToType = ToType; if (!FromPteeType.isNull() && !ToPteeType.isNull() && FromPteeType.getAddressSpace() != ToPteeType.getAddressSpace()) { NewToType = Context.removeAddrSpaceQualType(ToPteeType); NewToType = Context.getAddrSpaceQualType(NewToType, FromPteeType.getAddressSpace()); if (ToType->isObjCObjectPointerType()) NewToType = Context.getObjCObjectPointerType(NewToType); else if (ToType->isBlockPointerType()) NewToType = Context.getBlockPointerType(NewToType); else NewToType = Context.getPointerType(NewToType); } CastKind Kind; CXXCastPath BasePath; if (CheckPointerConversion(From, NewToType, 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().allowsNonTrivialObjCLifetimeQualifiers()) CheckObjCConversion(SourceRange(), NewToType, From, CCK); From = ImpCastExprToType(From, NewToType, Kind, VK_RValue, &BasePath, CCK) .get(); break; } case ICK_Pointer_Member: { CastKind Kind; 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->getBeginLoc(), 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_SVE_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 { auto *FromComplex = From->getType()->castAs(); 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: { LangAS AddrSpaceL = ToType->castAs()->getPointeeType().getAddressSpace(); LangAS AddrSpaceR = FromType->castAs()->getPointeeType().getAddressSpace(); assert(Qualifiers::isAddressSpaceSupersetOf(AddrSpaceL, AddrSpaceR) && "Invalid cast"); CastKind Kind = AddrSpaceL != AddrSpaceR ? CK_AddressSpaceConversion : CK_BitCast; From = ImpCastExprToType(From, ToType.getUnqualifiedType(), Kind, 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: case ICK_Zero_Queue_Conversion: From = ImpCastExprToType(From, ToType, CK_ZeroToOCLOpaqueType, From->getValueKind()).get(); break; case ICK_Lvalue_To_Rvalue: case ICK_Array_To_Pointer: case ICK_Function_To_Pointer: case ICK_Function_Conversion: case ICK_Qualification: case ICK_Num_Conversion_Kinds: case ICK_C_Only_Conversion: case ICK_Incompatible_Pointer_Conversion: llvm_unreachable("Improper second standard conversion"); } switch (SCS.Third) { case ICK_Identity: // Nothing to do. break; case ICK_Function_Conversion: // 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_Qualification: { ExprValueKind VK = From->getValueKind(); CastKind CK = CK_NoOp; if (ToType->isReferenceType() && ToType->getPointeeType().getAddressSpace() != From->getType().getAddressSpace()) CK = CK_AddressSpaceConversion; if (ToType->isPointerType() && ToType->getPointeeType().getAddressSpace() != From->getType()->getPointeeType().getAddressSpace()) CK = CK_AddressSpaceConversion; From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context), CK, VK, /*BasePath=*/nullptr, CCK) .get(); if (SCS.DeprecatedStringLiteralToCharPtr && !getLangOpts().WritableStrings) { Diag(From->getBeginLoc(), 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(); } // Materialize a temporary if we're implicitly converting to a reference // type. This is not required by the C++ rules but is necessary to maintain // AST invariants. if (ToType->isReferenceType() && From->isRValue()) { ExprResult Res = TemporaryMaterializationConversion(From); if (Res.isInvalid()) return ExprError(); From = Res.get(); } // If this conversion sequence succeeded and involved implicitly converting a // _Nullable type to a _Nonnull one, complain. if (!isCast(CCK)) diagnoseNullableToNonnullConversion(ToType, InitialFromType, From->getBeginLoc()); return From; } /// 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++1z [meta.unary.prop]: // remove_all_extents_t shall be a complete type or cv void. case UTT_IsAggregate: case UTT_IsTrivial: case UTT_IsTriviallyCopyable: case UTT_IsStandardLayout: case UTT_IsPOD: case UTT_IsLiteral: // Per the GCC type traits documentation, T shall be a complete type, cv void, // or an array of unknown bound. But GCC actually imposes the same constraints // as above. 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: ArgTy = QualType(ArgTy->getBaseElementTypeUnsafe(), 0); LLVM_FALLTHROUGH; // C++1z [meta.unary.prop]: // T shall be a complete type, cv void, or an array of unknown bound. case UTT_IsDestructible: case UTT_IsNothrowDestructible: case UTT_IsTriviallyDestructible: case UTT_HasUniqueObjectRepresentations: if (ArgTy->isIncompleteArrayType() || ArgTy->isVoidType()) return true; return !S.RequireCompleteType( Loc, ArgTy, 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; auto *CPT = Operator->getType()->castAs(); CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); if (!CPT || !CPT->isNothrow()) 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->isAnyPointerType(); 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; case UTT_IsAggregate: // Report vector extensions and complex types as aggregates because they // support aggregate initialization. GCC mirrors this behavior for vectors // but not _Complex. return T->isAggregateType() || T->isVectorType() || T->isExtVectorType() || T->isAnyComplexType(); // __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: // Enum types should always return false. // Floating points should always return true. return T->isFloatingType() || (T->isSignedIntegerType() && !T->isEnumeralType()); case UTT_IsUnsigned: // Enum types should always return false. return T->isUnsignedIntegerType() && !T->isEnumeralType(); // 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_IsTriviallyDestructible: 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; // A type that requires destruction (via a non-trivial destructor or ARC // lifetime semantics) is not trivially-destructible. if (UTT == UTT_IsTriviallyDestructible && T.isDestructedType()) 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) { auto *CPT = Destructor->getType()->castAs(); CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); if (!CPT || !CPT->isNothrow()) 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->getUnderlyingDecl())) continue; // UsingDecl itself is not a constructor if (isa(ND)) continue; auto *Constructor = cast(ND->getUnderlyingDecl()); if (Constructor->isCopyConstructor(FoundTQs)) { FoundConstructor = true; auto *CPT = Constructor->getType()->castAs(); 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() || 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->getUnderlyingDecl())) continue; // UsingDecl itself is not a constructor if (isa(ND)) continue; auto *Constructor = cast(ND->getUnderlyingDecl()); if (Constructor->isDefaultConstructor()) { FoundConstructor = true; auto *CPT = Constructor->getType()->castAs(); 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() || 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(); case UTT_HasUniqueObjectRepresentations: return C.hasUniqueObjectRepresentations(T); } } 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()); // Evaluate BTT_ReferenceBindsToTemporary alongside the IsConstructible // traits to avoid duplication. if (Kind <= BTT_Last && Kind != BTT_ReferenceBindsToTemporary) return EvaluateBinaryTypeTrait(S, Kind, Args[0]->getType(), Args[1]->getType(), RParenLoc); switch (Kind) { case clang::BTT_ReferenceBindsToTemporary: 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; llvm::BumpPtrAllocator OpaqueExprAllocator; 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); ArgExprs.push_back( new (OpaqueExprAllocator.Allocate()) OpaqueValueExpr(Args[I]->getTypeLoc().getBeginLoc(), ArgTy.getNonLValueExprType(S.Context), Expr::getValueKindForType(ArgTy))); } // Perform the initialization in an unevaluated context within a SFINAE // trap at translation unit scope. EnterExpressionEvaluationContext Unevaluated( S, Sema::ExpressionEvaluationContext::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::BTT_ReferenceBindsToTemporary) { if (!T->isReferenceType()) return false; return !Init.isDirectReferenceBinding(); } if (Kind == clang::TT_IsNothrowConstructible) return S.canThrow(Result.get()) == CT_Cannot; if (Kind == clang::TT_IsTriviallyConstructible) { // Under Objective-C ARC and Weak, if the destination has non-trivial // Objective-C lifetime, this is a non-trivial construction. if (T.getNonReferenceType().hasNonTrivialObjCLifetime()) 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(); const RecordType *rhsRecord = RhsT->getAs(); if (!rhsRecord || !lhsRecord) { const ObjCObjectType *LHSObjTy = LhsT->getAs(); const ObjCObjectType *RHSObjTy = RhsT->getAs(); if (!LHSObjTy || !RHSObjTy) return false; ObjCInterfaceDecl *BaseInterface = LHSObjTy->getInterface(); ObjCInterfaceDecl *DerivedInterface = RHSObjTy->getInterface(); if (!BaseInterface || !DerivedInterface) return false; if (Self.RequireCompleteType( KeyLoc, RhsT, diag::err_incomplete_type_used_in_type_trait_expr)) return false; return BaseInterface->isSuperClassOf(DerivedInterface); } assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT) == (lhsRecord == rhsRecord)); // Unions are never base classes, and never have base classes. // It doesn't matter if they are complete or not. See PR#41843 if (lhsRecord && lhsRecord->getDecl()->isUnion()) return false; if (rhsRecord && rhsRecord->getDecl()->isUnion()) return false; if (lhsRecord == rhsRecord) return true; // 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: { // GCC ignores cv-qualifiers on arrays for this builtin. Qualifiers LhsQuals, RhsQuals; QualType Lhs = Self.getASTContext().getUnqualifiedArrayType(LhsT, LhsQuals); QualType Rhs = Self.getASTContext().getUnqualifiedArrayType(RhsT, RhsQuals); return Self.Context.typesAreCompatible(Lhs, Rhs); } 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::ExpressionEvaluationContext::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::ExpressionEvaluationContext::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()) return false; // Treat the assignment as unused for the purpose of -Wdeprecated-volatile. Self.CheckUnusedVolatileAssignment(Result.get()); if (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 and Weak, if the destination has non-trivial // Objective-C lifetime, this is a non-trivial assignment. if (LhsT.getNonReferenceType().hasNonTrivialObjCLifetime()) 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) .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 ->*, and undergoes the // temporary materialization conversion otherwise. if (isIndirect) LHS = DefaultLvalueConversion(LHS.get()); else if (LHS.get()->isRValue()) LHS = TemporaryMaterializationConversion(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()->getBeginLoc(), RHS.get()->getEndLoc()), &BasePath)) return QualType(); // Cast LHS to type of use. QualType UseType = Context.getQualifiedType(Class, LHSType.getQualifiers()); if (isIndirect) UseType = Context.getPointerType(UseType); 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()) { // C++2a allows functions with ref-qualifier & if their cv-qualifier-seq // is (exactly) 'const'. if (Proto->isConst() && !Proto->isVolatile()) Diag(Loc, getLangOpts().CPlusPlus20 ? diag::warn_cxx17_compat_pointer_to_const_ref_member_on_rvalue : diag::ext_pointer_to_const_ref_member_on_rvalue); else 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; } /// 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->getBeginLoc(), 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 converted 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. TTy = TTy.getNonLValueExprType(Self.Context); 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; } /// 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->BuiltinParamTypes[0], Best->Conversions[0], Sema::AA_Converting); if (LHSRes.isInvalid()) break; LHS = LHSRes; ExprResult RHSRes = Self.PerformImplicitConversion( RHS.get(), Best->BuiltinParamTypes[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; } /// 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()->getBeginLoc(), 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; } // Check the condition operand of ?: to see if it is valid for the GCC // extension. static bool isValidVectorForConditionalCondition(ASTContext &Ctx, QualType CondTy) { if (!CondTy->isVectorType() && !CondTy->isExtVectorType()) return false; const QualType EltTy = cast(CondTy.getCanonicalType())->getElementType(); assert(!EltTy->isBooleanType() && !EltTy->isEnumeralType() && "Vectors cant be boolean or enum types"); return EltTy->isIntegralType(Ctx); } QualType Sema::CheckVectorConditionalTypes(ExprResult &Cond, ExprResult &LHS, ExprResult &RHS, SourceLocation QuestionLoc) { LHS = DefaultFunctionArrayLvalueConversion(LHS.get()); RHS = DefaultFunctionArrayLvalueConversion(RHS.get()); QualType CondType = Cond.get()->getType(); const auto *CondVT = CondType->castAs(); QualType CondElementTy = CondVT->getElementType(); unsigned CondElementCount = CondVT->getNumElements(); QualType LHSType = LHS.get()->getType(); const auto *LHSVT = LHSType->getAs(); QualType RHSType = RHS.get()->getType(); const auto *RHSVT = RHSType->getAs(); QualType ResultType; if (LHSVT && RHSVT) { if (isa(CondVT) != isa(LHSVT)) { Diag(QuestionLoc, diag::err_conditional_vector_cond_result_mismatch) << /*isExtVector*/ isa(CondVT); return {}; } // If both are vector types, they must be the same type. if (!Context.hasSameType(LHSType, RHSType)) { Diag(QuestionLoc, diag::err_conditional_vector_mismatched) << LHSType << RHSType; return {}; } ResultType = LHSType; } else if (LHSVT || RHSVT) { ResultType = CheckVectorOperands( LHS, RHS, QuestionLoc, /*isCompAssign*/ false, /*AllowBothBool*/ true, /*AllowBoolConversions*/ false); if (ResultType.isNull()) return {}; } else { // Both are scalar. QualType ResultElementTy; LHSType = LHSType.getCanonicalType().getUnqualifiedType(); RHSType = RHSType.getCanonicalType().getUnqualifiedType(); if (Context.hasSameType(LHSType, RHSType)) ResultElementTy = LHSType; else ResultElementTy = UsualArithmeticConversions(LHS, RHS, QuestionLoc, ACK_Conditional); if (ResultElementTy->isEnumeralType()) { Diag(QuestionLoc, diag::err_conditional_vector_operand_type) << ResultElementTy; return {}; } if (CondType->isExtVectorType()) ResultType = Context.getExtVectorType(ResultElementTy, CondVT->getNumElements()); else ResultType = Context.getVectorType( ResultElementTy, CondVT->getNumElements(), VectorType::GenericVector); LHS = ImpCastExprToType(LHS.get(), ResultType, CK_VectorSplat); RHS = ImpCastExprToType(RHS.get(), ResultType, CK_VectorSplat); } assert(!ResultType.isNull() && ResultType->isVectorType() && (!CondType->isExtVectorType() || ResultType->isExtVectorType()) && "Result should have been a vector type"); auto *ResultVectorTy = ResultType->castAs(); QualType ResultElementTy = ResultVectorTy->getElementType(); unsigned ResultElementCount = ResultVectorTy->getNumElements(); if (ResultElementCount != CondElementCount) { Diag(QuestionLoc, diag::err_conditional_vector_size) << CondType << ResultType; return {}; } if (Context.getTypeSize(ResultElementTy) != Context.getTypeSize(CondElementTy)) { Diag(QuestionLoc, diag::err_conditional_vector_element_size) << CondType << ResultType; return {}; } return ResultType; } /// 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.) /// /// This function also implements GCC's vector extension and the /// OpenCL/ext_vector_type extension for conditionals. The vector extensions /// permit the use of a?b:c where the type of a is that of a integer vector with /// the same number of elements and size as the vectors of b and c. If one of /// either b or c is a scalar it is implicitly converted to match the type of /// the vector. Otherwise the expression is ill-formed. If both b and c are /// scalars, then b and c are checked and converted to the type of a if /// possible. /// /// The expressions are evaluated differently for GCC's and OpenCL's extensions. /// For the GCC extension, the ?: operator is evaluated as /// (a[0] != 0 ? b[0] : c[0], .. , a[n] != 0 ? b[n] : c[n]). /// For the OpenCL extensions, the ?: operator is evaluated as /// (most-significant-bit-set(a[0]) ? b[0] : c[0], .. , /// most-significant-bit-set(a[n]) ? b[n] : c[n]). QualType Sema::CXXCheckConditionalOperands(ExprResult &Cond, ExprResult &LHS, ExprResult &RHS, ExprValueKind &VK, ExprObjectKind &OK, SourceLocation QuestionLoc) { // FIXME: Handle C99's complex types, block pointers and Obj-C++ interface // pointers. // Assume r-value. VK = VK_RValue; OK = OK_Ordinary; bool IsVectorConditional = isValidVectorForConditionalCondition(Context, Cond.get()->getType()); // C++11 [expr.cond]p1 // The first expression is contextually converted to bool. if (!Cond.get()->isTypeDependent()) { ExprResult CondRes = IsVectorConditional ? DefaultFunctionArrayLvalueConversion(Cond.get()) : CheckCXXBooleanCondition(Cond.get()); if (CondRes.isInvalid()) return QualType(); Cond = CondRes; } else { // To implement C++, the first expression typically doesn't alter the result // type of the conditional, however the GCC compatible vector extension // changes the result type to be that of the conditional. Since we cannot // know if this is a vector extension here, delay the conversion of the // LHS/RHS below until later. return Context.DependentTy; } // 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()); // Void expressions aren't legal in the vector-conditional expressions. if (IsVectorConditional) { SourceRange DiagLoc = LVoid ? LHS.get()->getSourceRange() : RHS.get()->getSourceRange(); bool IsThrow = LVoid ? LThrow : RThrow; Diag(DiagLoc.getBegin(), diag::err_conditional_vector_has_void) << DiagLoc << IsThrow; return QualType(); } 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. if (IsVectorConditional) return CheckVectorConditionalTypes(Cond, LHS, RHS, QuestionLoc); // 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. // FIXME: // Resolving a defect in P0012R1: we extend this to cover all cases where // one of the operands is reference-compatible with the other, in order // to support conditionals between functions differing in noexcept. This // will similarly cover difference in array bounds after P0388R4. // FIXME: If LTy and RTy have a composite pointer type, should we convert to // that instead? ExprValueKind LVK = LHS.get()->getValueKind(); ExprValueKind RVK = RHS.get()->getValueKind(); if (!Context.hasSameType(LTy, RTy) && LVK == RVK && LVK != VK_RValue) { // DerivedToBase was already handled by the class-specific case above. // FIXME: Should we allow ObjC conversions here? const ReferenceConversions AllowedConversions = ReferenceConversions::Qualification | ReferenceConversions::NestedQualification | ReferenceConversions::Function; ReferenceConversions RefConv; if (CompareReferenceRelationship(QuestionLoc, LTy, RTy, &RefConv) == Ref_Compatible && !(RefConv & ~AllowedConversions) && // [...] subject to the constraint that the reference must bind // directly [...] !RHS.get()->refersToBitField() && !RHS.get()->refersToVectorElement()) { RHS = ImpCastExprToType(RHS.get(), LTy, CK_NoOp, RVK); RTy = RHS.get()->getType(); } else if (CompareReferenceRelationship(QuestionLoc, RTy, LTy, &RefConv) == Ref_Compatible && !(RefConv & ~AllowedConversions) && !LHS.get()->refersToBitField() && !LHS.get()->refersToVectorElement()) { LHS = ImpCastExprToType(LHS.get(), RTy, CK_NoOp, LVK); LTy = LHS.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; // If we have function pointer types, unify them anyway to unify their // exception specifications, if any. if (LTy->isFunctionPointerType() || LTy->isMemberFunctionPointerType()) { Qualifiers Qs = LTy.getQualifiers(); LTy = FindCompositePointerType(QuestionLoc, LHS, RHS, /*ConvertArgs*/false); LTy = Context.getQualifiedType(LTy, Qs); assert(!LTy.isNull() && "failed to find composite pointer type for " "canonically equivalent function ptr types"); assert(Context.hasSameType(LTy, RTy) && "bad composite pointer type"); } 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. 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; } // If we have function pointer types, unify them anyway to unify their // exception specifications, if any. if (LTy->isFunctionPointerType() || LTy->isMemberFunctionPointerType()) { LTy = FindCompositePointerType(QuestionLoc, LHS, RHS); assert(!LTy.isNull() && "failed to find composite pointer type for " "canonically equivalent function ptr types"); } 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, QuestionLoc, ACK_Conditional); 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. QualType Composite = FindCompositePointerType(QuestionLoc, LHS, RHS); if (!Composite.isNull()) return Composite; // Similarly, attempt to find composite type of two objective-c pointers. Composite = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc); if (LHS.isInvalid() || RHS.isInvalid()) return QualType(); 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(); } static FunctionProtoType::ExceptionSpecInfo mergeExceptionSpecs(Sema &S, FunctionProtoType::ExceptionSpecInfo ESI1, FunctionProtoType::ExceptionSpecInfo ESI2, SmallVectorImpl &ExceptionTypeStorage) { ExceptionSpecificationType EST1 = ESI1.Type; ExceptionSpecificationType EST2 = ESI2.Type; // If either of them can throw anything, that is the result. if (EST1 == EST_None) return ESI1; if (EST2 == EST_None) return ESI2; if (EST1 == EST_MSAny) return ESI1; if (EST2 == EST_MSAny) return ESI2; if (EST1 == EST_NoexceptFalse) return ESI1; if (EST2 == EST_NoexceptFalse) return ESI2; // If either of them is non-throwing, the result is the other. if (EST1 == EST_NoThrow) return ESI2; if (EST2 == EST_NoThrow) return ESI1; if (EST1 == EST_DynamicNone) return ESI2; if (EST2 == EST_DynamicNone) return ESI1; if (EST1 == EST_BasicNoexcept) return ESI2; if (EST2 == EST_BasicNoexcept) return ESI1; if (EST1 == EST_NoexceptTrue) return ESI2; if (EST2 == EST_NoexceptTrue) return ESI1; // If we're left with value-dependent computed noexcept expressions, we're // stuck. Before C++17, we can just drop the exception specification entirely, // since it's not actually part of the canonical type. And this should never // happen in C++17, because it would mean we were computing the composite // pointer type of dependent types, which should never happen. if (EST1 == EST_DependentNoexcept || EST2 == EST_DependentNoexcept) { assert(!S.getLangOpts().CPlusPlus17 && "computing composite pointer type of dependent types"); return FunctionProtoType::ExceptionSpecInfo(); } // Switch over the possibilities so that people adding new values know to // update this function. switch (EST1) { case EST_None: case EST_DynamicNone: case EST_MSAny: case EST_BasicNoexcept: case EST_DependentNoexcept: case EST_NoexceptFalse: case EST_NoexceptTrue: case EST_NoThrow: llvm_unreachable("handled above"); case EST_Dynamic: { // This is the fun case: both exception specifications are dynamic. Form // the union of the two lists. assert(EST2 == EST_Dynamic && "other cases should already be handled"); llvm::SmallPtrSet Found; for (auto &Exceptions : {ESI1.Exceptions, ESI2.Exceptions}) for (QualType E : Exceptions) if (Found.insert(S.Context.getCanonicalType(E)).second) ExceptionTypeStorage.push_back(E); FunctionProtoType::ExceptionSpecInfo Result(EST_Dynamic); Result.Exceptions = ExceptionTypeStorage; return Result; } case EST_Unevaluated: case EST_Uninstantiated: case EST_Unparsed: llvm_unreachable("shouldn't see unresolved exception specifications here"); } llvm_unreachable("invalid ExceptionSpecificationType"); } /// Find a merged pointer type and convert the two expressions to it. /// /// This finds the composite pointer type for \p E1 and \p E2 according to /// C++2a [expr.type]p3. It converts both expressions to this type and returns /// it. It does not emit diagnostics (FIXME: that's not true if \p ConvertArgs /// is \c true). /// /// \param Loc The location of the operator requiring these two expressions to /// be converted to the composite pointer type. /// /// \param ConvertArgs If \c false, do not convert E1 and E2 to the target type. QualType Sema::FindCompositePointerType(SourceLocation Loc, Expr *&E1, Expr *&E2, bool ConvertArgs) { assert(getLangOpts().CPlusPlus && "This function assumes C++"); // C++1z [expr]p14: // The composite pointer type of two operands p1 and p2 having types T1 // and T2 QualType T1 = E1->getType(), T2 = E2->getType(); // where at least one is a pointer or pointer to member type or // std::nullptr_t is: bool T1IsPointerLike = T1->isAnyPointerType() || T1->isMemberPointerType() || T1->isNullPtrType(); bool T2IsPointerLike = T2->isAnyPointerType() || T2->isMemberPointerType() || T2->isNullPtrType(); if (!T1IsPointerLike && !T2IsPointerLike) return QualType(); // - if both p1 and p2 are null pointer constants, std::nullptr_t; // This can't actually happen, following the standard, but we also use this // to implement the end of [expr.conv], which hits this case. // // - if either p1 or p2 is a null pointer constant, T2 or T1, respectively; if (T1IsPointerLike && E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { if (ConvertArgs) E2 = ImpCastExprToType(E2, T1, T1->isMemberPointerType() ? CK_NullToMemberPointer : CK_NullToPointer).get(); return T1; } if (T2IsPointerLike && E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { if (ConvertArgs) E1 = ImpCastExprToType(E1, T2, T2->isMemberPointerType() ? CK_NullToMemberPointer : CK_NullToPointer).get(); return T2; } // Now both have to be pointers or member pointers. if (!T1IsPointerLike || !T2IsPointerLike) return QualType(); assert(!T1->isNullPtrType() && !T2->isNullPtrType() && "nullptr_t should be a null pointer constant"); struct Step { enum Kind { Pointer, ObjCPointer, MemberPointer, Array } K; // Qualifiers to apply under the step kind. Qualifiers Quals; /// The class for a pointer-to-member; a constant array type with a bound /// (if any) for an array. const Type *ClassOrBound; Step(Kind K, const Type *ClassOrBound = nullptr) : K(K), Quals(), ClassOrBound(ClassOrBound) {} QualType rebuild(ASTContext &Ctx, QualType T) const { T = Ctx.getQualifiedType(T, Quals); switch (K) { case Pointer: return Ctx.getPointerType(T); case MemberPointer: return Ctx.getMemberPointerType(T, ClassOrBound); case ObjCPointer: return Ctx.getObjCObjectPointerType(T); case Array: if (auto *CAT = cast_or_null(ClassOrBound)) return Ctx.getConstantArrayType(T, CAT->getSize(), nullptr, ArrayType::Normal, 0); else return Ctx.getIncompleteArrayType(T, ArrayType::Normal, 0); } llvm_unreachable("unknown step kind"); } }; SmallVector Steps; // - if T1 is "pointer to cv1 C1" and T2 is "pointer to cv2 C2", where C1 // is reference-related to C2 or C2 is reference-related to C1 (8.6.3), // the cv-combined type of T1 and T2 or the cv-combined type of T2 and T1, // respectively; // - if T1 is "pointer to member of C1 of type cv1 U1" and T2 is "pointer // to member of C2 of type cv2 U2" for some non-function type U, where // C1 is reference-related to C2 or C2 is reference-related to C1, the // cv-combined type of T2 and T1 or the cv-combined type of T1 and T2, // respectively; // - if T1 and T2 are similar types (4.5), the cv-combined type of T1 and // T2; // // Dismantle T1 and T2 to simultaneously determine whether they are similar // and to prepare to form the cv-combined type if so. QualType Composite1 = T1; QualType Composite2 = T2; unsigned NeedConstBefore = 0; while (true) { assert(!Composite1.isNull() && !Composite2.isNull()); Qualifiers Q1, Q2; Composite1 = Context.getUnqualifiedArrayType(Composite1, Q1); Composite2 = Context.getUnqualifiedArrayType(Composite2, Q2); // Top-level qualifiers are ignored. Merge at all lower levels. if (!Steps.empty()) { // Find the qualifier union: (approximately) the unique minimal set of // qualifiers that is compatible with both types. Qualifiers Quals = Qualifiers::fromCVRUMask(Q1.getCVRUQualifiers() | Q2.getCVRUQualifiers()); // Under one level of pointer or pointer-to-member, we can change to an // unambiguous compatible address space. if (Q1.getAddressSpace() == Q2.getAddressSpace()) { Quals.setAddressSpace(Q1.getAddressSpace()); } else if (Steps.size() == 1) { bool MaybeQ1 = Q1.isAddressSpaceSupersetOf(Q2); bool MaybeQ2 = Q2.isAddressSpaceSupersetOf(Q1); if (MaybeQ1 == MaybeQ2) return QualType(); // No unique best address space. Quals.setAddressSpace(MaybeQ1 ? Q1.getAddressSpace() : Q2.getAddressSpace()); } else { return QualType(); } // FIXME: In C, we merge __strong and none to __strong at the top level. if (Q1.getObjCGCAttr() == Q2.getObjCGCAttr()) Quals.setObjCGCAttr(Q1.getObjCGCAttr()); else if (T1->isVoidPointerType() || T2->isVoidPointerType()) assert(Steps.size() == 1); else return QualType(); // Mismatched lifetime qualifiers never compatibly include each other. if (Q1.getObjCLifetime() == Q2.getObjCLifetime()) Quals.setObjCLifetime(Q1.getObjCLifetime()); else if (T1->isVoidPointerType() || T2->isVoidPointerType()) assert(Steps.size() == 1); else return QualType(); Steps.back().Quals = Quals; if (Q1 != Quals || Q2 != Quals) NeedConstBefore = Steps.size() - 1; } // FIXME: Can we unify the following with UnwrapSimilarTypes? const PointerType *Ptr1, *Ptr2; if ((Ptr1 = Composite1->getAs()) && (Ptr2 = Composite2->getAs())) { Composite1 = Ptr1->getPointeeType(); Composite2 = Ptr2->getPointeeType(); Steps.emplace_back(Step::Pointer); continue; } const ObjCObjectPointerType *ObjPtr1, *ObjPtr2; if ((ObjPtr1 = Composite1->getAs()) && (ObjPtr2 = Composite2->getAs())) { Composite1 = ObjPtr1->getPointeeType(); Composite2 = ObjPtr2->getPointeeType(); Steps.emplace_back(Step::ObjCPointer); continue; } const MemberPointerType *MemPtr1, *MemPtr2; if ((MemPtr1 = Composite1->getAs()) && (MemPtr2 = Composite2->getAs())) { Composite1 = MemPtr1->getPointeeType(); Composite2 = MemPtr2->getPointeeType(); // At the top level, we can perform a base-to-derived pointer-to-member // conversion: // // - [...] where C1 is reference-related to C2 or C2 is // reference-related to C1 // // (Note that the only kinds of reference-relatedness in scope here are // "same type or derived from".) At any other level, the class must // exactly match. const Type *Class = nullptr; QualType Cls1(MemPtr1->getClass(), 0); QualType Cls2(MemPtr2->getClass(), 0); if (Context.hasSameType(Cls1, Cls2)) Class = MemPtr1->getClass(); else if (Steps.empty()) Class = IsDerivedFrom(Loc, Cls1, Cls2) ? MemPtr1->getClass() : IsDerivedFrom(Loc, Cls2, Cls1) ? MemPtr2->getClass() : nullptr; if (!Class) return QualType(); Steps.emplace_back(Step::MemberPointer, Class); continue; } // Special case: at the top level, we can decompose an Objective-C pointer // and a 'cv void *'. Unify the qualifiers. if (Steps.empty() && ((Composite1->isVoidPointerType() && Composite2->isObjCObjectPointerType()) || (Composite1->isObjCObjectPointerType() && Composite2->isVoidPointerType()))) { Composite1 = Composite1->getPointeeType(); Composite2 = Composite2->getPointeeType(); Steps.emplace_back(Step::Pointer); continue; } // FIXME: arrays // FIXME: block pointer types? // Cannot unwrap any more types. break; } // - if T1 or T2 is "pointer to noexcept function" and the other type is // "pointer to function", where the function types are otherwise the same, // "pointer to function"; // - if T1 or T2 is "pointer to member of C1 of type function", the other // type is "pointer to member of C2 of type noexcept function", and C1 // is reference-related to C2 or C2 is reference-related to C1, where // the function types are otherwise the same, "pointer to member of C2 of // type function" or "pointer to member of C1 of type function", // respectively; // // We also support 'noreturn' here, so as a Clang extension we generalize the // above to: // // - [Clang] If T1 and T2 are both of type "pointer to function" or // "pointer to member function" and the pointee types can be unified // by a function pointer conversion, that conversion is applied // before checking the following rules. // // We've already unwrapped down to the function types, and we want to merge // rather than just convert, so do this ourselves rather than calling // IsFunctionConversion. // // FIXME: In order to match the standard wording as closely as possible, we // currently only do this under a single level of pointers. Ideally, we would // allow this in general, and set NeedConstBefore to the relevant depth on // the side(s) where we changed anything. If we permit that, we should also // consider this conversion when determining type similarity and model it as // a qualification conversion. if (Steps.size() == 1) { if (auto *FPT1 = Composite1->getAs()) { if (auto *FPT2 = Composite2->getAs()) { FunctionProtoType::ExtProtoInfo EPI1 = FPT1->getExtProtoInfo(); FunctionProtoType::ExtProtoInfo EPI2 = FPT2->getExtProtoInfo(); // The result is noreturn if both operands are. bool Noreturn = EPI1.ExtInfo.getNoReturn() && EPI2.ExtInfo.getNoReturn(); EPI1.ExtInfo = EPI1.ExtInfo.withNoReturn(Noreturn); EPI2.ExtInfo = EPI2.ExtInfo.withNoReturn(Noreturn); // The result is nothrow if both operands are. SmallVector ExceptionTypeStorage; EPI1.ExceptionSpec = EPI2.ExceptionSpec = mergeExceptionSpecs(*this, EPI1.ExceptionSpec, EPI2.ExceptionSpec, ExceptionTypeStorage); Composite1 = Context.getFunctionType(FPT1->getReturnType(), FPT1->getParamTypes(), EPI1); Composite2 = Context.getFunctionType(FPT2->getReturnType(), FPT2->getParamTypes(), EPI2); } } } // There are some more conversions we can perform under exactly one pointer. if (Steps.size() == 1 && Steps.front().K == Step::Pointer && !Context.hasSameType(Composite1, Composite2)) { // - if T1 or T2 is "pointer to cv1 void" and the other type is // "pointer to cv2 T", where T is an object type or void, // "pointer to cv12 void", where cv12 is the union of cv1 and cv2; if (Composite1->isVoidType() && Composite2->isObjectType()) Composite2 = Composite1; else if (Composite2->isVoidType() && Composite1->isObjectType()) Composite1 = Composite2; // - if T1 is "pointer to cv1 C1" and T2 is "pointer to cv2 C2", where C1 // is reference-related to C2 or C2 is reference-related to C1 (8.6.3), // the cv-combined type of T1 and T2 or the cv-combined type of T2 and // T1, respectively; // // The "similar type" handling covers all of this except for the "T1 is a // base class of T2" case in the definition of reference-related. else if (IsDerivedFrom(Loc, Composite1, Composite2)) Composite1 = Composite2; else if (IsDerivedFrom(Loc, Composite2, Composite1)) Composite2 = Composite1; } // At this point, either the inner types are the same or we have failed to // find a composite pointer type. if (!Context.hasSameType(Composite1, Composite2)) return QualType(); // Per C++ [conv.qual]p3, add 'const' to every level before the last // differing qualifier. for (unsigned I = 0; I != NeedConstBefore; ++I) Steps[I].Quals.addConst(); // Rebuild the composite type. QualType Composite = Composite1; for (auto &S : llvm::reverse(Steps)) Composite = S.rebuild(Context, Composite); if (ConvertArgs) { // Convert the expressions to the composite pointer type. InitializedEntity Entity = InitializedEntity::InitializeTemporary(Composite); InitializationKind Kind = InitializationKind::CreateCopy(Loc, SourceLocation()); InitializationSequence E1ToC(*this, Entity, Kind, E1); if (!E1ToC) return QualType(); InitializationSequence E2ToC(*this, Entity, Kind, E2); if (!E2ToC) return QualType(); // FIXME: Let the caller know if these fail to avoid duplicate diagnostics. ExprResult E1Result = E1ToC.Perform(*this, Entity, Kind, E1); if (E1Result.isInvalid()) return QualType(); E1 = E1Result.get(); ExprResult E2Result = E2ToC.Perform(*this, Entity, Kind, E2); if (E2Result.isInvalid()) return QualType(); E2 = E2Result.get(); } return Composite; } 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(); auto *FTy = T->castAs(); 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)) { // Don't do reclaims if we're using the zero-element array // constant. if (ArrayLit->getNumElements() == 0 && Context.getLangOpts().ObjCRuntime.hasEmptyCollections()) return E; D = ArrayLit->getArrayWithObjectsMethod(); } else if (ObjCDictionaryLiteral *DictLit = dyn_cast(E)) { // Don't do reclaims if we're using the zero-element dictionary // constant. if (DictLit->getNumElements() == 0 && Context.getLangOpts().ObjCRuntime.hasEmptyCollections()) return 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, FPOptionsOverride()); } if (E->getType().isDestructedType() == QualType::DK_nontrivial_c_struct) Cleanup.setExprNeedsCleanups(true); 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().ExprContext == ExpressionEvaluationContextRecord::EK_Decltype; 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 = CompoundStmt::Create( Context, SubStmt, SourceLocation(), SourceLocation()); Expr *E = new (Context) StmtExpr(CompStmt, Context.VoidTy, SourceLocation(), SourceLocation(), /*FIXME TemplateDepth=*/0); 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().ExprContext == ExpressionEvaluationContextRecord::EK_Decltype && "not in a decltype expression"); ExprResult Result = CheckPlaceholderExpr(E); if (Result.isInvalid()) return ExprError(); E = Result.get(); // 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 BinaryOperator::Create(Context, BO->getLHS(), RHS.get(), BO_Comma, BO->getType(), BO->getValueKind(), BO->getObjectKind(), BO->getOperatorLoc(), BO->getFPFeatures(getLangOpts())); } } 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().ExprContext = ExpressionEvaluationContextRecord::EK_Other; Result = CheckUnevaluatedOperand(E); if (Result.isInvalid()) return ExprError(); E = Result.get(); // 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->getBeginLoc(), 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->getBeginLoc(), 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) { if (BaseType->isPointerType()) BaseType = BaseType->getPointeeType(); else if (auto *AT = Context.getAsArrayType(BaseType)) BaseType = AT->getElementType(); } } // 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->isRecordType()) { ObjectType = ParsedType::make(BaseType); 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) { // The operator requires a prvalue, so perform lvalue conversions. // Only do this if we might plausibly end with a pointer, as otherwise // this was likely to be intended to be a '.'. if (ObjectType->isPointerType() || ObjectType->isArrayType() || ObjectType->isFunctionType()) { ExprResult BaseResult = S.DefaultFunctionArrayLvalueConversion(Base); if (BaseResult.isInvalid()) return true; Base = BaseResult.get(); ObjectType = Base->getType(); } 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; } /// Check if it's ok to try and recover dot pseudo destructor calls on /// pointer objects. static bool canRecoverDotPseudoDestructorCallsOnPointerObjects(Sema &SemaRef, QualType DestructedType) { // If this is a record type, check if its destructor is callable. if (auto *RD = DestructedType->getAsCXXRecordDecl()) { if (RD->hasDefinition()) if (CXXDestructorDecl *D = SemaRef.LookupDestructor(RD)) return SemaRef.CanUseDecl(D, /*TreatUnavailableAsInvalid=*/false); return false; } // Otherwise, check if it's a type for which it's valid to use a pseudo-dtor. return DestructedType->isDependentType() || DestructedType->isScalarType() || DestructedType->isVectorType(); } 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)) { // Detect dot pseudo destructor calls on pointer objects, e.g.: // Foo *foo; // foo.~Foo(); if (OpKind == tok::period && ObjectType->isPointerType() && Context.hasSameUnqualifiedType(DestructedType, ObjectType->getPointeeType())) { auto Diagnostic = Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) << ObjectType << /*IsArrow=*/0 << Base->getSourceRange(); // Issue a fixit only when the destructor is valid. if (canRecoverDotPseudoDestructorCallsOnPointerObjects( *this, DestructedType)) Diagnostic << FixItHint::CreateReplacement(OpLoc, "->"); // Recover by setting the object type to the destructed type and the // operator to '->'. ObjectType = DestructedType; OpKind = tok::arrow; } else { 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() == UnqualifiedIdKind::IK_TemplateId || FirstTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) && "Invalid first type name in pseudo-destructor"); assert((SecondTypeName.getKind() == UnqualifiedIdKind::IK_TemplateId || SecondTypeName.getKind() == UnqualifiedIdKind::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() == UnqualifiedIdKind::IK_Identifier) { ParsedType T = getTypeName(*SecondTypeName.Identifier, SecondTypeName.StartLocation, S, &SS, true, false, ObjectTypePtrForLookup, /*IsCtorOrDtorName*/true); 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(S, SS, TemplateId->TemplateKWLoc, TemplateId->Template, TemplateId->Name, TemplateId->TemplateNameLoc, TemplateId->LAngleLoc, TemplateArgsPtr, TemplateId->RAngleLoc, /*IsCtorOrDtorName*/true); 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() == UnqualifiedIdKind::IK_TemplateId || FirstTypeName.Identifier) { if (FirstTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) { ParsedType T = getTypeName(*FirstTypeName.Identifier, FirstTypeName.StartLocation, S, &SS, true, false, ObjectTypePtrForLookup, /*IsCtorOrDtorName*/true); 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(S, SS, TemplateId->TemplateKWLoc, TemplateId->Template, TemplateId->Name, TemplateId->TemplateNameLoc, TemplateId->LAngleLoc, TemplateArgsPtr, TemplateId->RAngleLoc, /*IsCtorOrDtorName*/true); 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(); if (DS.getTypeSpecType() == DeclSpec::TST_decltype_auto) { Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid); return true; } 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) { // Convert the expression to match the conversion function's implicit object // parameter. ExprResult Exp = PerformObjectArgumentInitialization(E, /*Qualifier=*/nullptr, FoundDecl, Method); if (Exp.isInvalid()) return true; if (Method->getParent()->isLambda() && Method->getConversionType()->isBlockPointerType()) { // This is a lambda conversion to block pointer; check if the argument // was 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. PushExpressionEvaluationContext( ExpressionEvaluationContext::PotentiallyEvaluated); ExprResult BlockExp = BuildBlockForLambdaConversion( Exp.get()->getExprLoc(), Exp.get()->getExprLoc(), Method, Exp.get()); PopExpressionEvaluationContext(); // FIXME: This note should be produced by a CodeSynthesisContext. if (BlockExp.isInvalid()) Diag(Exp.get()->getExprLoc(), diag::note_lambda_to_block_conv); return BlockExp; } } MemberExpr *ME = BuildMemberExpr(Exp.get(), /*IsArrow=*/false, SourceLocation(), NestedNameSpecifierLoc(), SourceLocation(), Method, DeclAccessPair::make(FoundDecl, FoundDecl->getAccess()), HadMultipleCandidates, DeclarationNameInfo(), Context.BoundMemberTy, VK_RValue, OK_Ordinary); QualType ResultType = Method->getReturnType(); ExprValueKind VK = Expr::getValueKindForType(ResultType); ResultType = ResultType.getNonLValueExprType(Context); CXXMemberCallExpr *CE = CXXMemberCallExpr::Create( Context, ME, /*Args=*/{}, ResultType, VK, Exp.get()->getEndLoc(), CurFPFeatureOverrides()); if (CheckFunctionCall(Method, CE, Method->getType()->castAs())) return ExprError(); 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; R = CheckUnevaluatedOperand(R.get()); if (R.isInvalid()) return ExprError(); Operand = R.get(); if (!inTemplateInstantiation() && !Operand->isInstantiationDependent() && 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); } /// 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->isReadIfDiscardedInCPlusPlus11()) { ExprResult Res = DefaultLvalueConversion(E); if (Res.isInvalid()) return E; E = Res.get(); } else { // Per C++2a [expr.ass]p5, a volatile assignment is not deprecated if // it occurs as a discarded-value expression. CheckUnusedVolatileAssignment(E); } // C++1z: // If the expression is a prvalue after this optional conversion, the // temporary materialization conversion is applied. // // We skip this step: IR generation is able to synthesize the storage for // itself in the aggregate case, and adding the extra node to the AST is // just clutter. // FIXME: We don't emit lifetime markers for the temporaries due to this. // FIXME: Do any other AST consumers care about this? 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; } ExprResult Sema::CheckUnevaluatedOperand(Expr *E) { // Per C++2a [expr.ass]p5, a volatile assignment is not deprecated if // it occurs as an unevaluated operand. CheckUnusedVolatileAssignment(E); 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 !Var->isUsableInConstantExpressions(Context); } /// 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()); #ifndef NDEBUG DeclContext *DC = S.CurContext; while (DC && isa(DC)) DC = DC->getParent(); assert( CurrentLSI->CallOperator == DC && "The current call operator must be synchronized with Sema's CurContext"); #endif // NDEBUG const bool IsFullExprInstantiationDependent = FE->isInstantiationDependent(); // 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. CurrentLSI->visitPotentialCaptures([&] (VarDecl *Var, Expr *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) return; // 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( S.FunctionScopes, Var, S)) S.MarkCaptureUsedInEnclosingContext(Var, VarExpr->getExprLoc(), Index.getValue()); 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( S.FunctionScopes, /*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; /// 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). /// /// If we've failed to correct due to ambiguous corrections, we need to /// be sure to pass empty corrections and replacements. Otherwise it's /// possible that the Consumer has a TypoCorrection that failed to ambiguity /// and we don't want to report those diagnostics. void EmitAllDiagnostics(bool IsAmbiguous) { for (TypoExpr *TE : TypoExprs) { auto &State = SemaRef.getTypoExprState(TE); if (State.DiagHandler) { TypoCorrection TC = IsAmbiguous ? TypoCorrection() : State.Consumer->getCurrentCorrection(); ExprResult Replacement = IsAmbiguous ? ExprError() : 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); } } /// Try to advance the typo correction state of the first unfinished TypoExpr. /// We allow advancement of the correction stream by removing it from the /// TransformCache which allows `TransformTypoExpr` to advance during the /// next transformation attempt. /// /// Any substitution attempts for the previous TypoExprs (which must have been /// finished) will need to be retried since it's possible that they will now /// be invalid given the latest advancement. /// /// We need to be sure that we're making progress - it's possible that the /// tree is so malformed that the transform never makes it to the /// `TransformTypoExpr`. /// /// Returns true if there are any untried correction combinations. bool CheckAndAdvanceTypoExprCorrectionStreams() { for (auto TE : TypoExprs) { auto &State = SemaRef.getTypoExprState(TE); TransformCache.erase(TE); if (!State.Consumer->hasMadeAnyCorrectionProgress()) return false; 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()); } // Since correcting typos may intoduce new TypoExprs, this function // checks for new TypoExprs and recurses if it finds any. Note that it will // only succeed if it is able to correct all typos in the given expression. ExprResult CheckForRecursiveTypos(ExprResult Res, bool &IsAmbiguous) { if (Res.isInvalid()) { return Res; } // Check to see if any new TypoExprs were created. If so, we need to recurse // to check their validity. Expr *FixedExpr = Res.get(); auto SavedTypoExprs = std::move(TypoExprs); auto SavedAmbiguousTypoExprs = std::move(AmbiguousTypoExprs); TypoExprs.clear(); AmbiguousTypoExprs.clear(); FindTypoExprs(TypoExprs).TraverseStmt(FixedExpr); if (!TypoExprs.empty()) { // Recurse to handle newly created TypoExprs. If we're not able to // handle them, discard these TypoExprs. ExprResult RecurResult = RecursiveTransformLoop(FixedExpr, IsAmbiguous); if (RecurResult.isInvalid()) { Res = ExprError(); // Recursive corrections didn't work, wipe them away and don't add // them to the TypoExprs set. Remove them from Sema's TypoExpr list // since we don't want to clear them twice. Note: it's possible the // TypoExprs were created recursively and thus won't be in our // Sema's TypoExprs - they were created in our `RecursiveTransformLoop`. auto &SemaTypoExprs = SemaRef.TypoExprs; for (auto TE : TypoExprs) { TransformCache.erase(TE); SemaRef.clearDelayedTypo(TE); auto SI = find(SemaTypoExprs, TE); if (SI != SemaTypoExprs.end()) { SemaTypoExprs.erase(SI); } } } else { // TypoExpr is valid: add newly created TypoExprs since we were // able to correct them. Res = RecurResult; SavedTypoExprs.set_union(TypoExprs); } } TypoExprs = std::move(SavedTypoExprs); AmbiguousTypoExprs = std::move(SavedAmbiguousTypoExprs); return Res; } // Try to transform the given expression, looping through the correction // candidates with `CheckAndAdvanceTypoExprCorrectionStreams`. // // If valid ambiguous typo corrections are seen, `IsAmbiguous` is set to // true and this method immediately will return an `ExprError`. ExprResult RecursiveTransformLoop(Expr *E, bool &IsAmbiguous) { ExprResult Res; auto SavedTypoExprs = std::move(SemaRef.TypoExprs); SemaRef.TypoExprs.clear(); while (true) { Res = CheckForRecursiveTypos(TryTransform(E), IsAmbiguous); // Recursion encountered an ambiguous correction. This means that our // correction itself is ambiguous, so stop now. if (IsAmbiguous) break; // If the transform is still valid after checking for any new typos, // it's good to go. if (!Res.isInvalid()) break; // The transform was invalid, see if we have any TypoExprs with untried // correction candidates. if (!CheckAndAdvanceTypoExprCorrectionStreams()) break; } // If we found a valid result, double check to make sure it's not ambiguous. if (!IsAmbiguous && !Res.isInvalid() && !AmbiguousTypoExprs.empty()) { auto SavedTransformCache = llvm::SmallDenseMap(TransformCache); // Ensure none of the TypoExprs have multiple typo correction candidates // with the same edit length that pass all the checks and filters. while (!AmbiguousTypoExprs.empty()) { auto TE = AmbiguousTypoExprs.back(); // TryTransform itself can create new Typos, adding them to the TypoExpr map // and invalidating our TypoExprState, so always fetch it instead of storing. SemaRef.getTypoExprState(TE).Consumer->saveCurrentPosition(); TypoCorrection TC = SemaRef.getTypoExprState(TE).Consumer->peekNextCorrection(); TypoCorrection Next; do { // Fetch the next correction by erasing the typo from the cache and calling // `TryTransform` which will iterate through corrections in // `TransformTypoExpr`. TransformCache.erase(TE); ExprResult AmbigRes = CheckForRecursiveTypos(TryTransform(E), IsAmbiguous); if (!AmbigRes.isInvalid() || IsAmbiguous) { SemaRef.getTypoExprState(TE).Consumer->resetCorrectionStream(); SavedTransformCache.erase(TE); Res = ExprError(); IsAmbiguous = true; break; } } while ((Next = SemaRef.getTypoExprState(TE).Consumer->peekNextCorrection()) && Next.getEditDistance(false) == TC.getEditDistance(false)); if (IsAmbiguous) break; AmbiguousTypoExprs.remove(TE); SemaRef.getTypoExprState(TE).Consumer->restoreSavedPosition(); } TransformCache = std::move(SavedTransformCache); } // Wipe away any newly created TypoExprs that we don't know about. Since we // clear any invalid TypoExprs in `CheckForRecursiveTypos`, this is only // possible if a `TypoExpr` is created during a transformation but then // fails before we can discover it. auto &SemaTypoExprs = SemaRef.TypoExprs; for (auto Iterator = SemaTypoExprs.begin(); Iterator != SemaTypoExprs.end();) { auto TE = *Iterator; auto FI = find(TypoExprs, TE); if (FI != TypoExprs.end()) { Iterator++; continue; } SemaRef.clearDelayedTypo(TE); Iterator = SemaTypoExprs.erase(Iterator); } SemaRef.TypoExprs = std::move(SavedTypoExprs); return Res; } 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 Transform(Expr *E) { bool IsAmbiguous = false; ExprResult Res = RecursiveTransformLoop(E, IsAmbiguous); if (!Res.isUsable()) FindTypoExprs(TypoExprs).TraverseStmt(E); EmitAllDiagnostics(IsAmbiguous); 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; // FIXME: If we would typo-correct to an invalid declaration, it's // probably best to just suppress all errors from this typo correction. 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, bool RecoverUncorrectedTypos, 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 TyposResolved = DelayedTypos.size(); auto Result = TransformTypos(*this, InitDecl, Filter).Transform(E); TyposResolved -= DelayedTypos.size(); if (Result.isInvalid() || Result.get() != E) { ExprEvalContexts.back().NumTypos -= TyposResolved; if (Result.isInvalid() && RecoverUncorrectedTypos) { struct TyposReplace : TreeTransform { TyposReplace(Sema &SemaRef) : TreeTransform(SemaRef) {} ExprResult TransformTypoExpr(clang::TypoExpr *E) { return this->SemaRef.CreateRecoveryExpr(E->getBeginLoc(), E->getEndLoc(), {}); } } TT(*this); return TT.TransformExpr(E); } 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) { ExprResult FullExpr = FE; if (!FullExpr.get()) return ExprError(); if (DiagnoseUnexpandedParameterPack(FullExpr.get())) return ExprError(); if (DiscardedValue) { // Top-level expressions default to 'id' when we're in a debugger. if (getLangOpts().DebuggerCastResultToId && FullExpr.get()->getType() == Context.UnknownAnyTy) { FullExpr = forceUnknownAnyToType(FullExpr.get(), Context.getObjCIdType()); if (FullExpr.isInvalid()) return ExprError(); } FullExpr = CheckPlaceholderExpr(FullExpr.get()); if (FullExpr.isInvalid()) return ExprError(); FullExpr = IgnoredValueConversions(FullExpr.get()); if (FullExpr.isInvalid()) return ExprError(); DiagnoseUnusedExprResult(FullExpr.get()); } FullExpr = CorrectDelayedTyposInExpr(FullExpr.get(), /*InitDecl=*/nullptr, /*RecoverUncorrectedTypos=*/true); 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(/*IgnoreCapturedRegions=*/true); // 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." DeclContext *DC = CurContext; while (DC && isa(DC)) DC = DC->getParent(); const bool IsInLambdaDeclContext = isLambdaCallOperator(DC); 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 an unexpanded parameter pack. auto UPPC = IsIfExists ? UPPC_IfExists : UPPC_IfNotExists; if (DiagnoseUnexpandedParameterPack(SS, UPPC) || DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC)) return IER_Error; return CheckMicrosoftIfExistsSymbol(S, SS, TargetNameInfo); } concepts::Requirement *Sema::ActOnSimpleRequirement(Expr *E) { return BuildExprRequirement(E, /*IsSimple=*/true, /*NoexceptLoc=*/SourceLocation(), /*ReturnTypeRequirement=*/{}); } concepts::Requirement * Sema::ActOnTypeRequirement(SourceLocation TypenameKWLoc, CXXScopeSpec &SS, SourceLocation NameLoc, IdentifierInfo *TypeName, TemplateIdAnnotation *TemplateId) { assert(((!TypeName && TemplateId) || (TypeName && !TemplateId)) && "Exactly one of TypeName and TemplateId must be specified."); TypeSourceInfo *TSI = nullptr; if (TypeName) { QualType T = CheckTypenameType(ETK_Typename, TypenameKWLoc, SS.getWithLocInContext(Context), *TypeName, NameLoc, &TSI, /*DeducedTypeContext=*/false); if (T.isNull()) return nullptr; } else { ASTTemplateArgsPtr ArgsPtr(TemplateId->getTemplateArgs(), TemplateId->NumArgs); TypeResult T = ActOnTypenameType(CurScope, TypenameKWLoc, SS, TemplateId->TemplateKWLoc, TemplateId->Template, TemplateId->Name, TemplateId->TemplateNameLoc, TemplateId->LAngleLoc, ArgsPtr, TemplateId->RAngleLoc); if (T.isInvalid()) return nullptr; if (GetTypeFromParser(T.get(), &TSI).isNull()) return nullptr; } return BuildTypeRequirement(TSI); } concepts::Requirement * Sema::ActOnCompoundRequirement(Expr *E, SourceLocation NoexceptLoc) { return BuildExprRequirement(E, /*IsSimple=*/false, NoexceptLoc, /*ReturnTypeRequirement=*/{}); } concepts::Requirement * Sema::ActOnCompoundRequirement( Expr *E, SourceLocation NoexceptLoc, CXXScopeSpec &SS, TemplateIdAnnotation *TypeConstraint, unsigned Depth) { // C++2a [expr.prim.req.compound] p1.3.3 // [..] the expression is deduced against an invented function template // F [...] F is a void function template with a single type template // parameter T declared with the constrained-parameter. Form a new // cv-qualifier-seq cv by taking the union of const and volatile specifiers // around the constrained-parameter. F has a single parameter whose // type-specifier is cv T followed by the abstract-declarator. [...] // // The cv part is done in the calling function - we get the concept with // arguments and the abstract declarator with the correct CV qualification and // have to synthesize T and the single parameter of F. auto &II = Context.Idents.get("expr-type"); auto *TParam = TemplateTypeParmDecl::Create(Context, CurContext, SourceLocation(), SourceLocation(), Depth, /*Index=*/0, &II, /*Typename=*/true, /*ParameterPack=*/false, /*HasTypeConstraint=*/true); if (BuildTypeConstraint(SS, TypeConstraint, TParam, /*EllpsisLoc=*/SourceLocation(), /*AllowUnexpandedPack=*/true)) // Just produce a requirement with no type requirements. return BuildExprRequirement(E, /*IsSimple=*/false, NoexceptLoc, {}); auto *TPL = TemplateParameterList::Create(Context, SourceLocation(), SourceLocation(), ArrayRef(TParam), SourceLocation(), /*RequiresClause=*/nullptr); return BuildExprRequirement( E, /*IsSimple=*/false, NoexceptLoc, concepts::ExprRequirement::ReturnTypeRequirement(TPL)); } concepts::ExprRequirement * Sema::BuildExprRequirement( Expr *E, bool IsSimple, SourceLocation NoexceptLoc, concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement) { auto Status = concepts::ExprRequirement::SS_Satisfied; ConceptSpecializationExpr *SubstitutedConstraintExpr = nullptr; if (E->isInstantiationDependent() || ReturnTypeRequirement.isDependent()) Status = concepts::ExprRequirement::SS_Dependent; else if (NoexceptLoc.isValid() && canThrow(E) == CanThrowResult::CT_Can) Status = concepts::ExprRequirement::SS_NoexceptNotMet; else if (ReturnTypeRequirement.isSubstitutionFailure()) Status = concepts::ExprRequirement::SS_TypeRequirementSubstitutionFailure; else if (ReturnTypeRequirement.isTypeConstraint()) { // C++2a [expr.prim.req]p1.3.3 // The immediately-declared constraint ([temp]) of decltype((E)) shall // be satisfied. TemplateParameterList *TPL = ReturnTypeRequirement.getTypeConstraintTemplateParameterList(); QualType MatchedType = getDecltypeForParenthesizedExpr(E).getCanonicalType(); llvm::SmallVector Args; Args.push_back(TemplateArgument(MatchedType)); TemplateArgumentList TAL(TemplateArgumentList::OnStack, Args); MultiLevelTemplateArgumentList MLTAL(TAL); for (unsigned I = 0; I < TPL->getDepth(); ++I) MLTAL.addOuterRetainedLevel(); Expr *IDC = cast(TPL->getParam(0))->getTypeConstraint() ->getImmediatelyDeclaredConstraint(); ExprResult Constraint = SubstExpr(IDC, MLTAL); assert(!Constraint.isInvalid() && "Substitution cannot fail as it is simply putting a type template " "argument into a concept specialization expression's parameter."); SubstitutedConstraintExpr = cast(Constraint.get()); if (!SubstitutedConstraintExpr->isSatisfied()) Status = concepts::ExprRequirement::SS_ConstraintsNotSatisfied; } return new (Context) concepts::ExprRequirement(E, IsSimple, NoexceptLoc, ReturnTypeRequirement, Status, SubstitutedConstraintExpr); } concepts::ExprRequirement * Sema::BuildExprRequirement( concepts::Requirement::SubstitutionDiagnostic *ExprSubstitutionDiagnostic, bool IsSimple, SourceLocation NoexceptLoc, concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement) { return new (Context) concepts::ExprRequirement(ExprSubstitutionDiagnostic, IsSimple, NoexceptLoc, ReturnTypeRequirement); } concepts::TypeRequirement * Sema::BuildTypeRequirement(TypeSourceInfo *Type) { return new (Context) concepts::TypeRequirement(Type); } concepts::TypeRequirement * Sema::BuildTypeRequirement( concepts::Requirement::SubstitutionDiagnostic *SubstDiag) { return new (Context) concepts::TypeRequirement(SubstDiag); } concepts::Requirement *Sema::ActOnNestedRequirement(Expr *Constraint) { return BuildNestedRequirement(Constraint); } concepts::NestedRequirement * Sema::BuildNestedRequirement(Expr *Constraint) { ConstraintSatisfaction Satisfaction; if (!Constraint->isInstantiationDependent() && CheckConstraintSatisfaction(nullptr, {Constraint}, /*TemplateArgs=*/{}, Constraint->getSourceRange(), Satisfaction)) return nullptr; return new (Context) concepts::NestedRequirement(Context, Constraint, Satisfaction); } concepts::NestedRequirement * Sema::BuildNestedRequirement( concepts::Requirement::SubstitutionDiagnostic *SubstDiag) { return new (Context) concepts::NestedRequirement(SubstDiag); } RequiresExprBodyDecl * Sema::ActOnStartRequiresExpr(SourceLocation RequiresKWLoc, ArrayRef LocalParameters, Scope *BodyScope) { assert(BodyScope); RequiresExprBodyDecl *Body = RequiresExprBodyDecl::Create(Context, CurContext, RequiresKWLoc); PushDeclContext(BodyScope, Body); for (ParmVarDecl *Param : LocalParameters) { if (Param->hasDefaultArg()) // C++2a [expr.prim.req] p4 // [...] A local parameter of a requires-expression shall not have a // default argument. [...] Diag(Param->getDefaultArgRange().getBegin(), diag::err_requires_expr_local_parameter_default_argument); // Ignore default argument and move on Param->setDeclContext(Body); // If this has an identifier, add it to the scope stack. if (Param->getIdentifier()) { CheckShadow(BodyScope, Param); PushOnScopeChains(Param, BodyScope); } } return Body; } void Sema::ActOnFinishRequiresExpr() { assert(CurContext && "DeclContext imbalance!"); CurContext = CurContext->getLexicalParent(); assert(CurContext && "Popped translation unit!"); } ExprResult Sema::ActOnRequiresExpr(SourceLocation RequiresKWLoc, RequiresExprBodyDecl *Body, ArrayRef LocalParameters, ArrayRef Requirements, SourceLocation ClosingBraceLoc) { auto *RE = RequiresExpr::Create(Context, RequiresKWLoc, Body, LocalParameters, Requirements, ClosingBraceLoc); if (DiagnoseUnexpandedParameterPackInRequiresExpr(RE)) return ExprError(); return RE; }