|  | //===--- 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 "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/SemaInternal.h" | 
|  | #include "clang/Sema/Template.h" | 
|  | #include "llvm/ADT/STLExtras.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 nullptr; | 
|  |  | 
|  | 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 nullptr; | 
|  | } else if (isa<InjectedClassNameType>(Ty)) | 
|  | return cast<InjectedClassNameType>(Ty)->getDecl(); | 
|  | else | 
|  | return nullptr; | 
|  | } | 
|  |  | 
|  | /// \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 nullptr; | 
|  |  | 
|  | NestedNameSpecifier *NNS = 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 nullptr; | 
|  | } | 
|  |  | 
|  | // 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)) { | 
|  | // A declaration of the partial specialization must be visible. | 
|  | // We can always recover here, because this only happens when we're | 
|  | // entering the context, and that can't happen in a SFINAE context. | 
|  | assert(!isSFINAEContext() && | 
|  | "partial specialization scope specifier in SFINAE context?"); | 
|  | if (!hasVisibleDeclaration(PartialSpec)) | 
|  | diagnoseMissingImport(SS.getLastQualifierNameLoc(), PartialSpec, | 
|  | MissingImportKind::PartialSpecialization, | 
|  | /*Recover*/true); | 
|  | 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 nullptr; | 
|  | } | 
|  |  | 
|  | 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(); | 
|  |  | 
|  | case NestedNameSpecifier::Super: | 
|  | return NNS->getAsRecordDecl(); | 
|  | } | 
|  |  | 
|  | llvm_unreachable("Invalid NestedNameSpecifier::Kind!"); | 
|  | } | 
|  |  | 
|  | bool Sema::isDependentScopeSpecifier(const CXXScopeSpec &SS) { | 
|  | if (!SS.isSet() || SS.isInvalid()) | 
|  | return false; | 
|  |  | 
|  | return SS.getScopeRep()->isDependent(); | 
|  | } | 
|  |  | 
|  | /// \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 nullptr; | 
|  |  | 
|  | 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 && "given null context"); | 
|  |  | 
|  | TagDecl *tag = dyn_cast<TagDecl>(DC); | 
|  |  | 
|  | // If this is a dependent type, then we consider it complete. | 
|  | // FIXME: This is wrong; we should require a (visible) definition to | 
|  | // exist in this case too. | 
|  | 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) | 
|  | return false; | 
|  | if (enumType->getDecl()->isCompleteDefinition()) { | 
|  | // If we know about the definition but it is not visible, complain. | 
|  | NamedDecl *SuggestedDef = nullptr; | 
|  | if (!hasVisibleDefinition(enumType->getDecl(), &SuggestedDef, | 
|  | /*OnlyNeedComplete*/false)) { | 
|  | // If the user is going to see an error here, recover by making the | 
|  | // definition visible. | 
|  | bool TreatAsComplete = !isSFINAEContext(); | 
|  | diagnoseMissingImport(loc, SuggestedDef, MissingImportKind::Definition, | 
|  | /*Recover*/TreatAsComplete); | 
|  | return !TreatAsComplete; | 
|  | } | 
|  | 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(SourceLocation CCLoc, | 
|  | CXXScopeSpec &SS) { | 
|  | SS.MakeGlobal(Context, CCLoc); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | bool Sema::ActOnSuperScopeSpecifier(SourceLocation SuperLoc, | 
|  | SourceLocation ColonColonLoc, | 
|  | CXXScopeSpec &SS) { | 
|  | CXXRecordDecl *RD = nullptr; | 
|  | for (Scope *S = getCurScope(); S; S = S->getParent()) { | 
|  | if (S->isFunctionScope()) { | 
|  | if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(S->getEntity())) | 
|  | RD = MD->getParent(); | 
|  | break; | 
|  | } | 
|  | if (S->isClassScope()) { | 
|  | RD = cast<CXXRecordDecl>(S->getEntity()); | 
|  | break; | 
|  | } | 
|  | } | 
|  |  | 
|  | if (!RD) { | 
|  | Diag(SuperLoc, diag::err_invalid_super_scope); | 
|  | return true; | 
|  | } else if (RD->isLambda()) { | 
|  | Diag(SuperLoc, diag::err_super_in_lambda_unsupported); | 
|  | return true; | 
|  | } else if (RD->getNumBases() == 0) { | 
|  | Diag(SuperLoc, diag::err_no_base_classes) << RD->getName(); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | SS.MakeSuper(Context, RD, SuperLoc, ColonColonLoc); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | /// \brief Determines whether the given declaration is an valid acceptable | 
|  | /// result for name lookup of a nested-name-specifier. | 
|  | /// \param SD Declaration checked for nested-name-specifier. | 
|  | /// \param IsExtension If not null and the declaration is accepted as an | 
|  | /// extension, the pointed variable is assigned true. | 
|  | bool Sema::isAcceptableNestedNameSpecifier(const NamedDecl *SD, | 
|  | bool *IsExtension) { | 
|  | if (!SD) | 
|  | return false; | 
|  |  | 
|  | SD = SD->getUnderlyingDecl(); | 
|  |  | 
|  | // Namespace and namespace aliases are fine. | 
|  | if (isa<NamespaceDecl>(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; | 
|  | if (const TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(SD)) { | 
|  | if (TD->getUnderlyingType()->isRecordType()) | 
|  | return true; | 
|  | if (TD->getUnderlyingType()->isEnumeralType()) { | 
|  | if (Context.getLangOpts().CPlusPlus11) | 
|  | return true; | 
|  | if (IsExtension) | 
|  | *IsExtension = true; | 
|  | } | 
|  | } else if (isa<RecordDecl>(SD)) { | 
|  | return true; | 
|  | } else if (isa<EnumDecl>(SD)) { | 
|  | if (Context.getLangOpts().CPlusPlus11) | 
|  | return true; | 
|  | if (IsExtension) | 
|  | *IsExtension = 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 nullptr; | 
|  |  | 
|  | while (NNS->getPrefix()) | 
|  | NNS = NNS->getPrefix(); | 
|  |  | 
|  | if (NNS->getKind() != NestedNameSpecifier::Identifier) | 
|  | return nullptr; | 
|  |  | 
|  | LookupResult Found(*this, NNS->getAsIdentifier(), SourceLocation(), | 
|  | LookupNestedNameSpecifierName); | 
|  | LookupName(Found, S); | 
|  | assert(!Found.isAmbiguous() && "Cannot handle ambiguities here yet"); | 
|  |  | 
|  | if (!Found.isSingleResult()) | 
|  | return nullptr; | 
|  |  | 
|  | NamedDecl *Result = Found.getFoundDecl(); | 
|  | if (isAcceptableNestedNameSpecifier(Result)) | 
|  | return Result; | 
|  |  | 
|  | return nullptr; | 
|  | } | 
|  |  | 
|  | bool Sema::isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS, | 
|  | NestedNameSpecInfo &IdInfo) { | 
|  | QualType ObjectType = GetTypeFromParser(IdInfo.ObjectType); | 
|  | LookupResult Found(*this, IdInfo.Identifier, IdInfo.IdentifierLoc, | 
|  | LookupNestedNameSpecifierName); | 
|  |  | 
|  | // Determine where to perform name lookup | 
|  | DeclContext *LookupCtx = nullptr; | 
|  | 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(); | 
|  |  | 
|  | return Found.getAsSingle<NamespaceDecl>(); | 
|  | } | 
|  |  | 
|  | 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) {} | 
|  |  | 
|  | bool ValidateCandidate(const TypoCorrection &candidate) override { | 
|  | return SRef.isAcceptableNestedNameSpecifier(candidate.getCorrectionDecl()); | 
|  | } | 
|  |  | 
|  | private: | 
|  | Sema &SRef; | 
|  | }; | 
|  |  | 
|  | } | 
|  |  | 
|  | /// \brief Build a new nested-name-specifier for "identifier::", as described | 
|  | /// by ActOnCXXNestedNameSpecifier. | 
|  | /// | 
|  | /// \param S Scope in which the nested-name-specifier occurs. | 
|  | /// \param IdInfo Parser information about an identifier in the | 
|  | ///        nested-name-spec. | 
|  | /// \param EnteringContext If true, enter the context specified by the | 
|  | ///        nested-name-specifier. | 
|  | /// \param SS Optional nested name specifier preceding the identifier. | 
|  | /// \param ScopeLookupResult Provides the result of name lookup within the | 
|  | ///        scope of the nested-name-specifier that was computed at template | 
|  | ///        definition time. | 
|  | /// \param ErrorRecoveryLookup Specifies if the method is called to improve | 
|  | ///        error recovery and what kind of recovery is performed. | 
|  | /// \param IsCorrectedToColon If not null, suggestion of replace '::' -> ':' | 
|  | ///        are allowed.  The bool value pointed by this parameter is set to | 
|  | ///       'true' if the identifier is treated as if it was followed by ':', | 
|  | ///        not '::'. | 
|  | /// | 
|  | /// 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, | 
|  | NestedNameSpecInfo &IdInfo, | 
|  | bool EnteringContext, | 
|  | CXXScopeSpec &SS, | 
|  | NamedDecl *ScopeLookupResult, | 
|  | bool ErrorRecoveryLookup, | 
|  | bool *IsCorrectedToColon) { | 
|  | LookupResult Found(*this, IdInfo.Identifier, IdInfo.IdentifierLoc, | 
|  | LookupNestedNameSpecifierName); | 
|  | QualType ObjectType = GetTypeFromParser(IdInfo.ObjectType); | 
|  |  | 
|  | // Determine where to perform name lookup | 
|  | DeclContext *LookupCtx = nullptr; | 
|  | bool isDependent = false; | 
|  | if (IsCorrectedToColon) | 
|  | *IsCorrectedToColon = 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 (Found.isAmbiguous()) | 
|  | return true; | 
|  |  | 
|  | // 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, IdInfo.Identifier, IdInfo.IdentifierLoc, IdInfo.CCLoc); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | if (Found.empty() && !ErrorRecoveryLookup) { | 
|  | // If identifier is not found as class-name-or-namespace-name, but is found | 
|  | // as other entity, don't look for typos. | 
|  | LookupResult R(*this, Found.getLookupNameInfo(), LookupOrdinaryName); | 
|  | if (LookupCtx) | 
|  | LookupQualifiedName(R, LookupCtx); | 
|  | else if (S && !isDependent) | 
|  | LookupName(R, S); | 
|  | if (!R.empty()) { | 
|  | // Don't diagnose problems with this speculative lookup. | 
|  | R.suppressDiagnostics(); | 
|  | // The identifier is found in ordinary lookup. If correction to colon is | 
|  | // allowed, suggest replacement to ':'. | 
|  | if (IsCorrectedToColon) { | 
|  | *IsCorrectedToColon = true; | 
|  | Diag(IdInfo.CCLoc, diag::err_nested_name_spec_is_not_class) | 
|  | << IdInfo.Identifier << getLangOpts().CPlusPlus | 
|  | << FixItHint::CreateReplacement(IdInfo.CCLoc, ":"); | 
|  | if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) | 
|  | Diag(ND->getLocation(), diag::note_declared_at); | 
|  | return true; | 
|  | } | 
|  | // Replacement '::' -> ':' is not allowed, just issue respective error. | 
|  | Diag(R.getNameLoc(), diag::err_expected_class_or_namespace) | 
|  | << IdInfo.Identifier << getLangOpts().CPlusPlus; | 
|  | if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) | 
|  | Diag(ND->getLocation(), diag::note_entity_declared_at) | 
|  | << IdInfo.Identifier; | 
|  | return true; | 
|  | } | 
|  | } | 
|  |  | 
|  | if (Found.empty() && !ErrorRecoveryLookup && !getLangOpts().MSVCCompat) { | 
|  | // We haven't found anything, and we're not recovering from a | 
|  | // different kind of error, so look for typos. | 
|  | DeclarationName Name = Found.getLookupName(); | 
|  | Found.clear(); | 
|  | if (TypoCorrection Corrected = CorrectTypo( | 
|  | Found.getLookupNameInfo(), Found.getLookupKind(), S, &SS, | 
|  | llvm::make_unique<NestedNameSpecifierValidatorCCC>(*this), | 
|  | CTK_ErrorRecovery, LookupCtx, EnteringContext)) { | 
|  | if (LookupCtx) { | 
|  | bool DroppedSpecifier = | 
|  | Corrected.WillReplaceSpecifier() && | 
|  | Name.getAsString() == Corrected.getAsString(getLangOpts()); | 
|  | if (DroppedSpecifier) | 
|  | SS.clear(); | 
|  | diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest) | 
|  | << Name << LookupCtx << DroppedSpecifier | 
|  | << SS.getRange()); | 
|  | } else | 
|  | diagnoseTypo(Corrected, PDiag(diag::err_undeclared_var_use_suggest) | 
|  | << Name); | 
|  |  | 
|  | if (Corrected.getCorrectionSpecifier()) | 
|  | SS.MakeTrivial(Context, Corrected.getCorrectionSpecifier(), | 
|  | SourceRange(Found.getNameLoc())); | 
|  |  | 
|  | if (NamedDecl *ND = Corrected.getFoundDecl()) | 
|  | Found.addDecl(ND); | 
|  | Found.setLookupName(Corrected.getCorrection()); | 
|  | } else { | 
|  | Found.setLookupName(IdInfo.Identifier); | 
|  | } | 
|  | } | 
|  |  | 
|  | NamedDecl *SD = | 
|  | Found.isSingleResult() ? Found.getRepresentativeDecl() : nullptr; | 
|  | bool IsExtension = false; | 
|  | bool AcceptSpec = isAcceptableNestedNameSpecifier(SD, &IsExtension); | 
|  | if (!AcceptSpec && IsExtension) { | 
|  | AcceptSpec = true; | 
|  | Diag(IdInfo.IdentifierLoc, diag::ext_nested_name_spec_is_enum); | 
|  | } | 
|  | if (AcceptSpec) { | 
|  | 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, IdInfo.Identifier, IdInfo.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(IdInfo.IdentifierLoc, | 
|  | diag::err_nested_name_member_ref_lookup_ambiguous) | 
|  | << IdInfo.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 (auto *TD = dyn_cast_or_null<TypedefNameDecl>(SD)) | 
|  | MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false); | 
|  |  | 
|  | // 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; | 
|  |  | 
|  | // The use of a nested name specifier may trigger deprecation warnings. | 
|  | DiagnoseUseOfDecl(SD, IdInfo.CCLoc); | 
|  |  | 
|  | if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD)) { | 
|  | SS.Extend(Context, Namespace, IdInfo.IdentifierLoc, IdInfo.CCLoc); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD)) { | 
|  | SS.Extend(Context, Alias, IdInfo.IdentifierLoc, IdInfo.CCLoc); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | QualType T = | 
|  | Context.getTypeDeclType(cast<TypeDecl>(SD->getUnderlyingDecl())); | 
|  | TypeLocBuilder TLB; | 
|  | if (isa<InjectedClassNameType>(T)) { | 
|  | InjectedClassNameTypeLoc InjectedTL | 
|  | = TLB.push<InjectedClassNameTypeLoc>(T); | 
|  | InjectedTL.setNameLoc(IdInfo.IdentifierLoc); | 
|  | } else if (isa<RecordType>(T)) { | 
|  | RecordTypeLoc RecordTL = TLB.push<RecordTypeLoc>(T); | 
|  | RecordTL.setNameLoc(IdInfo.IdentifierLoc); | 
|  | } else if (isa<TypedefType>(T)) { | 
|  | TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(T); | 
|  | TypedefTL.setNameLoc(IdInfo.IdentifierLoc); | 
|  | } else if (isa<EnumType>(T)) { | 
|  | EnumTypeLoc EnumTL = TLB.push<EnumTypeLoc>(T); | 
|  | EnumTL.setNameLoc(IdInfo.IdentifierLoc); | 
|  | } else if (isa<TemplateTypeParmType>(T)) { | 
|  | TemplateTypeParmTypeLoc TemplateTypeTL | 
|  | = TLB.push<TemplateTypeParmTypeLoc>(T); | 
|  | TemplateTypeTL.setNameLoc(IdInfo.IdentifierLoc); | 
|  | } else if (isa<UnresolvedUsingType>(T)) { | 
|  | UnresolvedUsingTypeLoc UnresolvedTL | 
|  | = TLB.push<UnresolvedUsingTypeLoc>(T); | 
|  | UnresolvedTL.setNameLoc(IdInfo.IdentifierLoc); | 
|  | } else if (isa<SubstTemplateTypeParmType>(T)) { | 
|  | SubstTemplateTypeParmTypeLoc TL | 
|  | = TLB.push<SubstTemplateTypeParmTypeLoc>(T); | 
|  | TL.setNameLoc(IdInfo.IdentifierLoc); | 
|  | } else if (isa<SubstTemplateTypeParmPackType>(T)) { | 
|  | SubstTemplateTypeParmPackTypeLoc TL | 
|  | = TLB.push<SubstTemplateTypeParmPackTypeLoc>(T); | 
|  | TL.setNameLoc(IdInfo.IdentifierLoc); | 
|  | } else { | 
|  | llvm_unreachable("Unhandled TypeDecl node in nested-name-specifier"); | 
|  | } | 
|  |  | 
|  | if (T->isEnumeralType()) | 
|  | Diag(IdInfo.IdentifierLoc, diag::warn_cxx98_compat_enum_nested_name_spec); | 
|  |  | 
|  | SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T), | 
|  | IdInfo.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().MSVCCompat) { | 
|  | DeclContext *DC = LookupCtx ? LookupCtx : CurContext; | 
|  | if (DC->isDependentContext() && DC->isFunctionOrMethod()) { | 
|  | CXXRecordDecl *ContainingClass = dyn_cast<CXXRecordDecl>(DC->getParent()); | 
|  | if (ContainingClass && ContainingClass->hasAnyDependentBases()) { | 
|  | Diag(IdInfo.IdentifierLoc, | 
|  | diag::ext_undeclared_unqual_id_with_dependent_base) | 
|  | << IdInfo.Identifier << ContainingClass; | 
|  | SS.Extend(Context, IdInfo.Identifier, IdInfo.IdentifierLoc, | 
|  | IdInfo.CCLoc); | 
|  | return false; | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | if (!Found.empty()) { | 
|  | if (TypeDecl *TD = Found.getAsSingle<TypeDecl>()) | 
|  | Diag(IdInfo.IdentifierLoc, diag::err_expected_class_or_namespace) | 
|  | << QualType(TD->getTypeForDecl(), 0) << getLangOpts().CPlusPlus; | 
|  | else { | 
|  | Diag(IdInfo.IdentifierLoc, diag::err_expected_class_or_namespace) | 
|  | << IdInfo.Identifier << getLangOpts().CPlusPlus; | 
|  | if (NamedDecl *ND = Found.getAsSingle<NamedDecl>()) | 
|  | Diag(ND->getLocation(), diag::note_entity_declared_at) | 
|  | << IdInfo.Identifier; | 
|  | } | 
|  | } else if (SS.isSet()) | 
|  | Diag(IdInfo.IdentifierLoc, diag::err_no_member) << IdInfo.Identifier | 
|  | << LookupCtx << SS.getRange(); | 
|  | else | 
|  | Diag(IdInfo.IdentifierLoc, diag::err_undeclared_var_use) | 
|  | << IdInfo.Identifier; | 
|  |  | 
|  | return true; | 
|  | } | 
|  |  | 
|  | bool Sema::ActOnCXXNestedNameSpecifier(Scope *S, | 
|  | NestedNameSpecInfo &IdInfo, | 
|  | bool EnteringContext, | 
|  | CXXScopeSpec &SS, | 
|  | bool ErrorRecoveryLookup, | 
|  | bool *IsCorrectedToColon) { | 
|  | if (SS.isInvalid()) | 
|  | return true; | 
|  |  | 
|  | return BuildCXXNestedNameSpecifier(S, IdInfo, | 
|  | EnteringContext, SS, | 
|  | /*ScopeLookupResult=*/nullptr, false, | 
|  | IsCorrectedToColon); | 
|  | } | 
|  |  | 
|  | 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_or_namespace) | 
|  | << 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, | 
|  | NestedNameSpecInfo &IdInfo, | 
|  | bool EnteringContext) { | 
|  | if (SS.isInvalid()) | 
|  | return false; | 
|  |  | 
|  | return !BuildCXXNestedNameSpecifier(S, IdInfo, EnteringContext, SS, | 
|  | /*ScopeLookupResult=*/nullptr, 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); | 
|  |  | 
|  | DependentTemplateName *DTN = Template.get().getAsDependentTemplateName(); | 
|  | if (DTN && DTN->isIdentifier()) { | 
|  | // Handle a dependent template specialization for which we cannot resolve | 
|  | // the template name. | 
|  | assert(DTN->getQualifier() == 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; | 
|  | } | 
|  |  | 
|  | TemplateDecl *TD = Template.get().getAsTemplateDecl(); | 
|  | if (Template.get().getAsOverloadedTemplate() || DTN || | 
|  | isa<FunctionTemplateDecl>(TD) || isa<VarTemplateDecl>(TD)) { | 
|  | SourceRange R(TemplateNameLoc, RAngleLoc); | 
|  | if (SS.getRange().isValid()) | 
|  | R.setBegin(SS.getRange().getBegin()); | 
|  |  | 
|  | Diag(CCLoc, diag::err_non_type_template_in_nested_name_specifier) | 
|  | << (TD && isa<VarTemplateDecl>(TD)) << 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 nullptr; | 
|  |  | 
|  | 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 = 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: | 
|  | case NestedNameSpecifier::Super: | 
|  | // 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); | 
|  | } |