C++ NestedNameSpecifier::getAsType方法代码示例

void NestedNameSpecifierLocBuilder::MakeTrivial(ASTContext &Context, 
                                                NestedNameSpecifier *Qualifier, 
                                                SourceRange R) {
  Representation = Qualifier;
  
  // Construct bogus (but well-formed) source information for the 
  // nested-name-specifier.
  BufferSize = 0;
  SmallVector<NestedNameSpecifier *, 4> Stack;
  for (NestedNameSpecifier *NNS = Qualifier; NNS; NNS = NNS->getPrefix())
    Stack.push_back(NNS);
  while (!Stack.empty()) {
    NestedNameSpecifier *NNS = Stack.back();
    Stack.pop_back();
    switch (NNS->getKind()) {
      case NestedNameSpecifier::Identifier:
      case NestedNameSpecifier::Namespace:
      case NestedNameSpecifier::NamespaceAlias:
        SaveSourceLocation(R.getBegin(), Buffer, BufferSize, BufferCapacity);
        break;
        
      case NestedNameSpecifier::TypeSpec:
      case NestedNameSpecifier::TypeSpecWithTemplate: {
        TypeSourceInfo *TSInfo
        = Context.getTrivialTypeSourceInfo(QualType(NNS->getAsType(), 0),
                                           R.getBegin());
        SavePointer(TSInfo->getTypeLoc().getOpaqueData(), Buffer, BufferSize, 
                    BufferCapacity);
        break;
      }
        
      case NestedNameSpecifier::Global:
        break;
    }
    
    // Save the location of the '::'.
    SaveSourceLocation(Stack.empty()? R.getEnd() : R.getBegin(), 
                       Buffer, BufferSize, BufferCapacity);
  }
}

/// \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();
  } break;

  case NestedNameSpecifier::Global:
    return Context.getTranslationUnitDecl();
  }

  // Required to silence a GCC warning.
  return 0;
}

/// 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:
//.........这里部分代码省略.........