//===--- SemaCXXScopeSpec.cpp - Semantic Analysis for C++ scope specifiers-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements C++ semantic analysis for scope specifiers. // //===----------------------------------------------------------------------===// #include "clang/Sema/SemaInternal.h" #include "TypeLocBuilder.h" #include "clang/AST/ASTContext.h" #include "clang/AST/DeclTemplate.h" #include "clang/AST/ExprCXX.h" #include "clang/AST/NestedNameSpecifier.h" #include "clang/Basic/PartialDiagnostic.h" #include "clang/Sema/DeclSpec.h" #include "clang/Sema/Lookup.h" #include "clang/Sema/Template.h" #include "llvm/ADT/STLExtras.h" #include "llvm/Support/raw_ostream.h" using namespace clang; /// \brief Find the current instantiation that associated with the given type. static CXXRecordDecl *getCurrentInstantiationOf(QualType T, DeclContext *CurContext) { if (T.isNull()) return 0; const Type *Ty = T->getCanonicalTypeInternal().getTypePtr(); if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) { CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordTy->getDecl()); if (!Record->isDependentContext() || Record->isCurrentInstantiation(CurContext)) return Record; return 0; } else if (isa<InjectedClassNameType>(Ty)) return cast<InjectedClassNameType>(Ty)->getDecl(); else return 0; } /// \brief Compute the DeclContext that is associated with the given type. /// /// \param T the type for which we are attempting to find a DeclContext. /// /// \returns the declaration context represented by the type T, /// or NULL if the declaration context cannot be computed (e.g., because it is /// dependent and not the current instantiation). DeclContext *Sema::computeDeclContext(QualType T) { if (!T->isDependentType()) if (const TagType *Tag = T->getAs<TagType>()) return Tag->getDecl(); return ::getCurrentInstantiationOf(T, CurContext); } /// \brief Compute the DeclContext that is associated with the given /// scope specifier. /// /// \param SS the C++ scope specifier as it appears in the source /// /// \param EnteringContext when true, we will be entering the context of /// this scope specifier, so we can retrieve the declaration context of a /// class template or class template partial specialization even if it is /// not the current instantiation. /// /// \returns the declaration context represented by the scope specifier @p SS, /// or NULL if the declaration context cannot be computed (e.g., because it is /// dependent and not the current instantiation). DeclContext *Sema::computeDeclContext(const CXXScopeSpec &SS, bool EnteringContext) { if (!SS.isSet() || SS.isInvalid()) return 0; NestedNameSpecifier *NNS = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); if (NNS->isDependent()) { // If this nested-name-specifier refers to the current // instantiation, return its DeclContext. if (CXXRecordDecl *Record = getCurrentInstantiationOf(NNS)) return Record; if (EnteringContext) { const Type *NNSType = NNS->getAsType(); if (!NNSType) { return 0; } // Look through type alias templates, per C++0x [temp.dep.type]p1. NNSType = Context.getCanonicalType(NNSType); if (const TemplateSpecializationType *SpecType = NNSType->getAs<TemplateSpecializationType>()) { // We are entering the context of the nested name specifier, so try to // match the nested name specifier to either a primary class template // or a class template partial specialization. if (ClassTemplateDecl *ClassTemplate = dyn_cast_or_null<ClassTemplateDecl>( SpecType->getTemplateName().getAsTemplateDecl())) { QualType ContextType = Context.getCanonicalType(QualType(SpecType, 0)); // If the type of the nested name specifier is the same as the // injected class name of the named class template, we're entering // into that class template definition. QualType Injected = ClassTemplate->getInjectedClassNameSpecialization(); if (Context.hasSameType(Injected, ContextType)) return ClassTemplate->getTemplatedDecl(); // If the type of the nested name specifier is the same as the // type of one of the class template's class template partial // specializations, we're entering into the definition of that // class template partial specialization. if (ClassTemplatePartialSpecializationDecl *PartialSpec = ClassTemplate->findPartialSpecialization(ContextType)) return PartialSpec; } } else if (const RecordType *RecordT = NNSType->getAs<RecordType>()) { // The nested name specifier refers to a member of a class template. return RecordT->getDecl(); } } return 0; } switch (NNS->getKind()) { case NestedNameSpecifier::Identifier: llvm_unreachable("Dependent nested-name-specifier has no DeclContext"); case NestedNameSpecifier::Namespace: return NNS->getAsNamespace(); case NestedNameSpecifier::NamespaceAlias: return NNS->getAsNamespaceAlias()->getNamespace(); case NestedNameSpecifier::TypeSpec: case NestedNameSpecifier::TypeSpecWithTemplate: { const TagType *Tag = NNS->getAsType()->getAs<TagType>(); assert(Tag && "Non-tag type in nested-name-specifier"); return Tag->getDecl(); } case NestedNameSpecifier::Global: return Context.getTranslationUnitDecl(); } llvm_unreachable("Invalid NestedNameSpecifier::Kind!"); } bool Sema::isDependentScopeSpecifier(const CXXScopeSpec &SS) { if (!SS.isSet() || SS.isInvalid()) return false; NestedNameSpecifier *NNS = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); return NNS->isDependent(); } // \brief Determine whether this C++ scope specifier refers to an // unknown specialization, i.e., a dependent type that is not the // current instantiation. bool Sema::isUnknownSpecialization(const CXXScopeSpec &SS) { if (!isDependentScopeSpecifier(SS)) return false; NestedNameSpecifier *NNS = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); return getCurrentInstantiationOf(NNS) == 0; } /// \brief If the given nested name specifier refers to the current /// instantiation, return the declaration that corresponds to that /// current instantiation (C++0x [temp.dep.type]p1). /// /// \param NNS a dependent nested name specifier. CXXRecordDecl *Sema::getCurrentInstantiationOf(NestedNameSpecifier *NNS) { assert(getLangOpts().CPlusPlus && "Only callable in C++"); assert(NNS->isDependent() && "Only dependent nested-name-specifier allowed"); if (!NNS->getAsType()) return 0; QualType T = QualType(NNS->getAsType(), 0); return ::getCurrentInstantiationOf(T, CurContext); } /// \brief Require that the context specified by SS be complete. /// /// If SS refers to a type, this routine checks whether the type is /// complete enough (or can be made complete enough) for name lookup /// into the DeclContext. A type that is not yet completed can be /// considered "complete enough" if it is a class/struct/union/enum /// that is currently being defined. Or, if we have a type that names /// a class template specialization that is not a complete type, we /// will attempt to instantiate that class template. bool Sema::RequireCompleteDeclContext(CXXScopeSpec &SS, DeclContext *DC) { assert(DC != 0 && "given null context"); TagDecl *tag = dyn_cast<TagDecl>(DC); // If this is a dependent type, then we consider it complete. if (!tag || tag->isDependentContext()) return false; // If we're currently defining this type, then lookup into the // type is okay: don't complain that it isn't complete yet. QualType type = Context.getTypeDeclType(tag); const TagType *tagType = type->getAs<TagType>(); if (tagType && tagType->isBeingDefined()) return false; SourceLocation loc = SS.getLastQualifierNameLoc(); if (loc.isInvalid()) loc = SS.getRange().getBegin(); // The type must be complete. if (RequireCompleteType(loc, type, diag::err_incomplete_nested_name_spec, SS.getRange())) { SS.SetInvalid(SS.getRange()); return true; } // Fixed enum types are complete, but they aren't valid as scopes // until we see a definition, so awkwardly pull out this special // case. const EnumType *enumType = dyn_cast_or_null<EnumType>(tagType); if (!enumType || enumType->getDecl()->isCompleteDefinition()) return false; // Try to instantiate the definition, if this is a specialization of an // enumeration temploid. EnumDecl *ED = enumType->getDecl(); if (EnumDecl *Pattern = ED->getInstantiatedFromMemberEnum()) { MemberSpecializationInfo *MSI = ED->getMemberSpecializationInfo(); if (MSI->getTemplateSpecializationKind() != TSK_ExplicitSpecialization) { if (InstantiateEnum(loc, ED, Pattern, getTemplateInstantiationArgs(ED), TSK_ImplicitInstantiation)) { SS.SetInvalid(SS.getRange()); return true; } return false; } } Diag(loc, diag::err_incomplete_nested_name_spec) << type << SS.getRange(); SS.SetInvalid(SS.getRange()); return true; } bool Sema::ActOnCXXGlobalScopeSpecifier(Scope *S, SourceLocation CCLoc, CXXScopeSpec &SS) { SS.MakeGlobal(Context, CCLoc); return false; } /// \brief Determines whether the given declaration is an valid acceptable /// result for name lookup of a nested-name-specifier. bool Sema::isAcceptableNestedNameSpecifier(const NamedDecl *SD) { if (!SD) return false; // Namespace and namespace aliases are fine. if (isa<NamespaceDecl>(SD) || isa<NamespaceAliasDecl>(SD)) return true; if (!isa<TypeDecl>(SD)) return false; // Determine whether we have a class (or, in C++11, an enum) or // a typedef thereof. If so, build the nested-name-specifier. QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); if (T->isDependentType()) return true; else if (const TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(SD)) { if (TD->getUnderlyingType()->isRecordType() || (Context.getLangOpts().CPlusPlus11 && TD->getUnderlyingType()->isEnumeralType())) return true; } else if (isa<RecordDecl>(SD) || (Context.getLangOpts().CPlusPlus11 && isa<EnumDecl>(SD))) return true; return false; } /// \brief If the given nested-name-specifier begins with a bare identifier /// (e.g., Base::), perform name lookup for that identifier as a /// nested-name-specifier within the given scope, and return the result of that /// name lookup. NamedDecl *Sema::FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS) { if (!S || !NNS) return 0; while (NNS->getPrefix()) NNS = NNS->getPrefix(); if (NNS->getKind() != NestedNameSpecifier::Identifier) return 0; LookupResult Found(*this, NNS->getAsIdentifier(), SourceLocation(), LookupNestedNameSpecifierName); LookupName(Found, S); assert(!Found.isAmbiguous() && "Cannot handle ambiguities here yet"); if (!Found.isSingleResult()) return 0; NamedDecl *Result = Found.getFoundDecl(); if (isAcceptableNestedNameSpecifier(Result)) return Result; return 0; } bool Sema::isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS, SourceLocation IdLoc, IdentifierInfo &II, ParsedType ObjectTypePtr) { QualType ObjectType = GetTypeFromParser(ObjectTypePtr); LookupResult Found(*this, &II, IdLoc, LookupNestedNameSpecifierName); // Determine where to perform name lookup DeclContext *LookupCtx = 0; bool isDependent = false; if (!ObjectType.isNull()) { // This nested-name-specifier occurs in a member access expression, e.g., // x->B::f, and we are looking into the type of the object. assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); LookupCtx = computeDeclContext(ObjectType); isDependent = ObjectType->isDependentType(); } else if (SS.isSet()) { // This nested-name-specifier occurs after another nested-name-specifier, // so long into the context associated with the prior nested-name-specifier. LookupCtx = computeDeclContext(SS, false); isDependent = isDependentScopeSpecifier(SS); Found.setContextRange(SS.getRange()); } if (LookupCtx) { // Perform "qualified" name lookup into the declaration context we // computed, which is either the type of the base of a member access // expression or the declaration context associated with a prior // nested-name-specifier. // The declaration context must be complete. if (!LookupCtx->isDependentContext() && RequireCompleteDeclContext(SS, LookupCtx)) return false; LookupQualifiedName(Found, LookupCtx); } else if (isDependent) { return false; } else { LookupName(Found, S); } Found.suppressDiagnostics(); if (NamedDecl *ND = Found.getAsSingle<NamedDecl>()) return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND); return false; } namespace { // Callback to only accept typo corrections that can be a valid C++ member // intializer: either a non-static field member or a base class. class NestedNameSpecifierValidatorCCC : public CorrectionCandidateCallback { public: explicit NestedNameSpecifierValidatorCCC(Sema &SRef) : SRef(SRef) {} virtual bool ValidateCandidate(const TypoCorrection &candidate) { return SRef.isAcceptableNestedNameSpecifier(candidate.getCorrectionDecl()); } private: Sema &SRef; }; } /// \brief Build a new nested-name-specifier for "identifier::", as described /// by ActOnCXXNestedNameSpecifier. /// /// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in /// that it contains an extra parameter \p ScopeLookupResult, which provides /// the result of name lookup within the scope of the nested-name-specifier /// that was computed at template definition time. /// /// If ErrorRecoveryLookup is true, then this call is used to improve error /// recovery. This means that it should not emit diagnostics, it should /// just return true on failure. It also means it should only return a valid /// scope if it *knows* that the result is correct. It should not return in a /// dependent context, for example. Nor will it extend \p SS with the scope /// specifier. bool Sema::BuildCXXNestedNameSpecifier(Scope *S, IdentifierInfo &Identifier, SourceLocation IdentifierLoc, SourceLocation CCLoc, QualType ObjectType, bool EnteringContext, CXXScopeSpec &SS, NamedDecl *ScopeLookupResult, bool ErrorRecoveryLookup) { LookupResult Found(*this, &Identifier, IdentifierLoc, LookupNestedNameSpecifierName); // Determine where to perform name lookup DeclContext *LookupCtx = 0; bool isDependent = false; if (!ObjectType.isNull()) { // This nested-name-specifier occurs in a member access expression, e.g., // x->B::f, and we are looking into the type of the object. assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); LookupCtx = computeDeclContext(ObjectType); isDependent = ObjectType->isDependentType(); } else if (SS.isSet()) { // This nested-name-specifier occurs after another nested-name-specifier, // so look into the context associated with the prior nested-name-specifier. LookupCtx = computeDeclContext(SS, EnteringContext); isDependent = isDependentScopeSpecifier(SS); Found.setContextRange(SS.getRange()); } bool ObjectTypeSearchedInScope = false; if (LookupCtx) { // Perform "qualified" name lookup into the declaration context we // computed, which is either the type of the base of a member access // expression or the declaration context associated with a prior // nested-name-specifier. // The declaration context must be complete. if (!LookupCtx->isDependentContext() && RequireCompleteDeclContext(SS, LookupCtx)) return true; LookupQualifiedName(Found, LookupCtx); if (!ObjectType.isNull() && Found.empty()) { // 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 -> operator is // looked up both in the context of the entire postfix-expression and in // the scope of the class of the object expression. If the name is found // only in the scope of the class of the object expression, the name // shall refer to a class-name. If the name is found only in the // context of the entire postfix-expression, the name shall refer to a // class-name or namespace-name. [...] // // Qualified name lookup into a class will not find a namespace-name, // so we do not need to diagnose that case specifically. However, // this qualified name lookup may find nothing. In that case, perform // unqualified name lookup in the given scope (if available) or // reconstruct the result from when name lookup was performed at template // definition time. if (S) LookupName(Found, S); else if (ScopeLookupResult) Found.addDecl(ScopeLookupResult); ObjectTypeSearchedInScope = true; } } else if (!isDependent) { // Perform unqualified name lookup in the current scope. LookupName(Found, S); } // If we performed lookup into a dependent context and did not find anything, // that's fine: just build a dependent nested-name-specifier. if (Found.empty() && isDependent && !(LookupCtx && LookupCtx->isRecord() && (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() || !cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases()))) { // Don't speculate if we're just trying to improve error recovery. if (ErrorRecoveryLookup) return true; // We were not able to compute the declaration context for a dependent // base object type or prior nested-name-specifier, so this // nested-name-specifier refers to an unknown specialization. Just build // a dependent nested-name-specifier. SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc); return false; } // FIXME: Deal with ambiguities cleanly. if (Found.empty() && !ErrorRecoveryLookup) { // We haven't found anything, and we're not recovering from a // different kind of error, so look for typos. DeclarationName Name = Found.getLookupName(); NestedNameSpecifierValidatorCCC Validator(*this); TypoCorrection Corrected; Found.clear(); if ((Corrected = CorrectTypo(Found.getLookupNameInfo(), Found.getLookupKind(), S, &SS, Validator, LookupCtx, EnteringContext))) { std::string CorrectedStr(Corrected.getAsString(getLangOpts())); std::string CorrectedQuotedStr(Corrected.getQuoted(getLangOpts())); if (LookupCtx) Diag(Found.getNameLoc(), diag::err_no_member_suggest) << Name << LookupCtx << CorrectedQuotedStr << SS.getRange() << FixItHint::CreateReplacement(Corrected.getCorrectionRange(), CorrectedStr); else Diag(Found.getNameLoc(), diag::err_undeclared_var_use_suggest) << Name << CorrectedQuotedStr << FixItHint::CreateReplacement(Found.getNameLoc(), CorrectedStr); if (NamedDecl *ND = Corrected.getCorrectionDecl()) { Diag(ND->getLocation(), diag::note_previous_decl) << CorrectedQuotedStr; Found.addDecl(ND); } Found.setLookupName(Corrected.getCorrection()); } else { Found.setLookupName(&Identifier); } } NamedDecl *SD = Found.getAsSingle<NamedDecl>(); if (isAcceptableNestedNameSpecifier(SD)) { if (!ObjectType.isNull() && !ObjectTypeSearchedInScope && !getLangOpts().CPlusPlus11) { // C++03 [basic.lookup.classref]p4: // [...] If the name is found in both contexts, the // class-name-or-namespace-name shall refer to the same entity. // // We already found the name in the scope of the object. Now, look // into the current scope (the scope of the postfix-expression) to // see if we can find the same name there. As above, if there is no // scope, reconstruct the result from the template instantiation itself. // // Note that C++11 does *not* perform this redundant lookup. NamedDecl *OuterDecl; if (S) { LookupResult FoundOuter(*this, &Identifier, IdentifierLoc, LookupNestedNameSpecifierName); LookupName(FoundOuter, S); OuterDecl = FoundOuter.getAsSingle<NamedDecl>(); } else OuterDecl = ScopeLookupResult; if (isAcceptableNestedNameSpecifier(OuterDecl) && OuterDecl->getCanonicalDecl() != SD->getCanonicalDecl() && (!isa<TypeDecl>(OuterDecl) || !isa<TypeDecl>(SD) || !Context.hasSameType( Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)), Context.getTypeDeclType(cast<TypeDecl>(SD))))) { if (ErrorRecoveryLookup) return true; Diag(IdentifierLoc, diag::err_nested_name_member_ref_lookup_ambiguous) << &Identifier; Diag(SD->getLocation(), diag::note_ambig_member_ref_object_type) << ObjectType; Diag(OuterDecl->getLocation(), diag::note_ambig_member_ref_scope); // Fall through so that we'll pick the name we found in the object // type, since that's probably what the user wanted anyway. } } // If we're just performing this lookup for error-recovery purposes, // don't extend the nested-name-specifier. Just return now. if (ErrorRecoveryLookup) return false; if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD)) { SS.Extend(Context, Namespace, IdentifierLoc, CCLoc); return false; } if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD)) { SS.Extend(Context, Alias, IdentifierLoc, CCLoc); return false; } QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); TypeLocBuilder TLB; if (isa<InjectedClassNameType>(T)) { InjectedClassNameTypeLoc InjectedTL = TLB.push<InjectedClassNameTypeLoc>(T); InjectedTL.setNameLoc(IdentifierLoc); } else if (isa<RecordType>(T)) { RecordTypeLoc RecordTL = TLB.push<RecordTypeLoc>(T); RecordTL.setNameLoc(IdentifierLoc); } else if (isa<TypedefType>(T)) { TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(T); TypedefTL.setNameLoc(IdentifierLoc); } else if (isa<EnumType>(T)) { EnumTypeLoc EnumTL = TLB.push<EnumTypeLoc>(T); EnumTL.setNameLoc(IdentifierLoc); } else if (isa<TemplateTypeParmType>(T)) { TemplateTypeParmTypeLoc TemplateTypeTL = TLB.push<TemplateTypeParmTypeLoc>(T); TemplateTypeTL.setNameLoc(IdentifierLoc); } else if (isa<UnresolvedUsingType>(T)) { UnresolvedUsingTypeLoc UnresolvedTL = TLB.push<UnresolvedUsingTypeLoc>(T); UnresolvedTL.setNameLoc(IdentifierLoc); } else if (isa<SubstTemplateTypeParmType>(T)) { SubstTemplateTypeParmTypeLoc TL = TLB.push<SubstTemplateTypeParmTypeLoc>(T); TL.setNameLoc(IdentifierLoc); } else if (isa<SubstTemplateTypeParmPackType>(T)) { SubstTemplateTypeParmPackTypeLoc TL = TLB.push<SubstTemplateTypeParmPackTypeLoc>(T); TL.setNameLoc(IdentifierLoc); } else { llvm_unreachable("Unhandled TypeDecl node in nested-name-specifier"); } if (T->isEnumeralType()) Diag(IdentifierLoc, diag::warn_cxx98_compat_enum_nested_name_spec); SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T), CCLoc); return false; } // Otherwise, we have an error case. If we don't want diagnostics, just // return an error now. if (ErrorRecoveryLookup) return true; // If we didn't find anything during our lookup, try again with // ordinary name lookup, which can help us produce better error // messages. if (Found.empty()) { Found.clear(LookupOrdinaryName); LookupName(Found, S); } // In Microsoft mode, if we are within a templated function and we can't // resolve Identifier, then extend the SS with Identifier. This will have // the effect of resolving Identifier during template instantiation. // The goal is to be able to resolve a function call whose // nested-name-specifier is located inside a dependent base class. // Example: // // class C { // public: // static void foo2() { } // }; // template <class T> class A { public: typedef C D; }; // // template <class T> class B : public A<T> { // public: // void foo() { D::foo2(); } // }; if (getLangOpts().MicrosoftExt) { DeclContext *DC = LookupCtx ? LookupCtx : CurContext; if (DC->isDependentContext() && DC->isFunctionOrMethod()) { SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc); return false; } } unsigned DiagID; if (!Found.empty()) DiagID = diag::err_expected_class_or_namespace; else if (SS.isSet()) { Diag(IdentifierLoc, diag::err_no_member) << &Identifier << LookupCtx << SS.getRange(); return true; } else DiagID = diag::err_undeclared_var_use; if (SS.isSet()) Diag(IdentifierLoc, DiagID) << &Identifier << SS.getRange(); else Diag(IdentifierLoc, DiagID) << &Identifier; return true; } bool Sema::ActOnCXXNestedNameSpecifier(Scope *S, IdentifierInfo &Identifier, SourceLocation IdentifierLoc, SourceLocation CCLoc, ParsedType ObjectType, bool EnteringContext, CXXScopeSpec &SS) { if (SS.isInvalid()) return true; return BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, CCLoc, GetTypeFromParser(ObjectType), EnteringContext, SS, /*ScopeLookupResult=*/0, false); } bool Sema::ActOnCXXNestedNameSpecifierDecltype(CXXScopeSpec &SS, const DeclSpec &DS, SourceLocation ColonColonLoc) { if (SS.isInvalid() || DS.getTypeSpecType() == DeclSpec::TST_error) return true; assert(DS.getTypeSpecType() == DeclSpec::TST_decltype); QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc()); if (!T->isDependentType() && !T->getAs<TagType>()) { Diag(DS.getTypeSpecTypeLoc(), diag::err_expected_class) << T << getLangOpts().CPlusPlus; return true; } TypeLocBuilder TLB; DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T); DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc()); SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T), ColonColonLoc); return false; } /// IsInvalidUnlessNestedName - This method is used for error recovery /// purposes to determine whether the specified identifier is only valid as /// a nested name specifier, for example a namespace name. It is /// conservatively correct to always return false from this method. /// /// The arguments are the same as those passed to ActOnCXXNestedNameSpecifier. bool Sema::IsInvalidUnlessNestedName(Scope *S, CXXScopeSpec &SS, IdentifierInfo &Identifier, SourceLocation IdentifierLoc, SourceLocation ColonLoc, ParsedType ObjectType, bool EnteringContext) { if (SS.isInvalid()) return false; return !BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, ColonLoc, GetTypeFromParser(ObjectType), EnteringContext, SS, /*ScopeLookupResult=*/0, true); } bool Sema::ActOnCXXNestedNameSpecifier(Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc, TemplateTy Template, SourceLocation TemplateNameLoc, SourceLocation LAngleLoc, ASTTemplateArgsPtr TemplateArgsIn, SourceLocation RAngleLoc, SourceLocation CCLoc, bool EnteringContext) { if (SS.isInvalid()) return true; // Translate the parser's template argument list in our AST format. TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); translateTemplateArguments(TemplateArgsIn, TemplateArgs); if (DependentTemplateName *DTN = Template.get().getAsDependentTemplateName()){ // Handle a dependent template specialization for which we cannot resolve // the template name. assert(DTN->getQualifier() == static_cast<NestedNameSpecifier*>(SS.getScopeRep())); QualType T = Context.getDependentTemplateSpecializationType(ETK_None, DTN->getQualifier(), DTN->getIdentifier(), TemplateArgs); // Create source-location information for this type. TypeLocBuilder Builder; DependentTemplateSpecializationTypeLoc SpecTL = Builder.push<DependentTemplateSpecializationTypeLoc>(T); SpecTL.setElaboratedKeywordLoc(SourceLocation()); SpecTL.setQualifierLoc(SS.getWithLocInContext(Context)); SpecTL.setTemplateKeywordLoc(TemplateKWLoc); SpecTL.setTemplateNameLoc(TemplateNameLoc); SpecTL.setLAngleLoc(LAngleLoc); SpecTL.setRAngleLoc(RAngleLoc); for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); SS.Extend(Context, TemplateKWLoc, Builder.getTypeLocInContext(Context, T), CCLoc); return false; } if (Template.get().getAsOverloadedTemplate() || isa<FunctionTemplateDecl>(Template.get().getAsTemplateDecl())) { SourceRange R(TemplateNameLoc, RAngleLoc); if (SS.getRange().isValid()) R.setBegin(SS.getRange().getBegin()); Diag(CCLoc, diag::err_non_type_template_in_nested_name_specifier) << Template.get() << R; NoteAllFoundTemplates(Template.get()); return true; } // We were able to resolve the template name to an actual template. // Build an appropriate nested-name-specifier. QualType T = CheckTemplateIdType(Template.get(), TemplateNameLoc, TemplateArgs); if (T.isNull()) return true; // Alias template specializations can produce types which are not valid // nested name specifiers. if (!T->isDependentType() && !T->getAs<TagType>()) { Diag(TemplateNameLoc, diag::err_nested_name_spec_non_tag) << T; NoteAllFoundTemplates(Template.get()); return true; } // Provide source-location information for the template specialization type. TypeLocBuilder Builder; TemplateSpecializationTypeLoc SpecTL = Builder.push<TemplateSpecializationTypeLoc>(T); SpecTL.setTemplateKeywordLoc(TemplateKWLoc); SpecTL.setTemplateNameLoc(TemplateNameLoc); SpecTL.setLAngleLoc(LAngleLoc); SpecTL.setRAngleLoc(RAngleLoc); for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); SS.Extend(Context, TemplateKWLoc, Builder.getTypeLocInContext(Context, T), CCLoc); return false; } namespace { /// \brief A structure that stores a nested-name-specifier annotation, /// including both the nested-name-specifier struct NestedNameSpecifierAnnotation { NestedNameSpecifier *NNS; }; } void *Sema::SaveNestedNameSpecifierAnnotation(CXXScopeSpec &SS) { if (SS.isEmpty() || SS.isInvalid()) return 0; void *Mem = Context.Allocate((sizeof(NestedNameSpecifierAnnotation) + SS.location_size()), llvm::alignOf<NestedNameSpecifierAnnotation>()); NestedNameSpecifierAnnotation *Annotation = new (Mem) NestedNameSpecifierAnnotation; Annotation->NNS = SS.getScopeRep(); memcpy(Annotation + 1, SS.location_data(), SS.location_size()); return Annotation; } void Sema::RestoreNestedNameSpecifierAnnotation(void *AnnotationPtr, SourceRange AnnotationRange, CXXScopeSpec &SS) { if (!AnnotationPtr) { SS.SetInvalid(AnnotationRange); return; } NestedNameSpecifierAnnotation *Annotation = static_cast<NestedNameSpecifierAnnotation *>(AnnotationPtr); SS.Adopt(NestedNameSpecifierLoc(Annotation->NNS, Annotation + 1)); } bool Sema::ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); NestedNameSpecifier *Qualifier = static_cast<NestedNameSpecifier*>(SS.getScopeRep()); // There are only two places a well-formed program may qualify a // declarator: first, when defining a namespace or class member // out-of-line, and second, when naming an explicitly-qualified // friend function. The latter case is governed by // C++03 [basic.lookup.unqual]p10: // In a friend declaration naming a member function, a name used // in the function declarator and not part of a template-argument // in a template-id is first looked up in the scope of the member // function's class. If it is not found, or if the name is part of // a template-argument in a template-id, the look up is as // described for unqualified names in the definition of the class // granting friendship. // i.e. we don't push a scope unless it's a class member. switch (Qualifier->getKind()) { case NestedNameSpecifier::Global: case NestedNameSpecifier::Namespace: case NestedNameSpecifier::NamespaceAlias: // These are always namespace scopes. We never want to enter a // namespace scope from anything but a file context. return CurContext->getRedeclContext()->isFileContext(); case NestedNameSpecifier::Identifier: case NestedNameSpecifier::TypeSpec: case NestedNameSpecifier::TypeSpecWithTemplate: // These are never namespace scopes. return true; } llvm_unreachable("Invalid NestedNameSpecifier::Kind!"); } /// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global /// scope or nested-name-specifier) is parsed, part of a declarator-id. /// After this method is called, according to [C++ 3.4.3p3], names should be /// looked up in the declarator-id's scope, until the declarator is parsed and /// ActOnCXXExitDeclaratorScope is called. /// The 'SS' should be a non-empty valid CXXScopeSpec. bool Sema::ActOnCXXEnterDeclaratorScope(Scope *S, CXXScopeSpec &SS) { assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); if (SS.isInvalid()) return true; DeclContext *DC = computeDeclContext(SS, true); if (!DC) return true; // Before we enter a declarator's context, we need to make sure that // it is a complete declaration context. if (!DC->isDependentContext() && RequireCompleteDeclContext(SS, DC)) return true; EnterDeclaratorContext(S, DC); // Rebuild the nested name specifier for the new scope. if (DC->isDependentContext()) RebuildNestedNameSpecifierInCurrentInstantiation(SS); return false; } /// ActOnCXXExitDeclaratorScope - Called when a declarator that previously /// invoked ActOnCXXEnterDeclaratorScope(), is finished. 'SS' is the same /// CXXScopeSpec that was passed to ActOnCXXEnterDeclaratorScope as well. /// Used to indicate that names should revert to being looked up in the /// defining scope. void Sema::ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); if (SS.isInvalid()) return; assert(!SS.isInvalid() && computeDeclContext(SS, true) && "exiting declarator scope we never really entered"); ExitDeclaratorContext(S); }