| //===--- ParseTemplate.cpp - Template Parsing -----------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements parsing of C++ templates. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/Parse/Parser.h" |
| #include "clang/Parse/ParseDiagnostic.h" |
| #include "clang/Sema/DeclSpec.h" |
| #include "clang/Sema/ParsedTemplate.h" |
| #include "clang/Sema/Scope.h" |
| #include "RAIIObjectsForParser.h" |
| using namespace clang; |
| |
| /// \brief Parse a template declaration, explicit instantiation, or |
| /// explicit specialization. |
| Decl * |
| Parser::ParseDeclarationStartingWithTemplate(unsigned Context, |
| SourceLocation &DeclEnd, |
| AccessSpecifier AS) { |
| if (Tok.is(tok::kw_template) && NextToken().isNot(tok::less)) |
| return ParseExplicitInstantiation(SourceLocation(), ConsumeToken(), |
| DeclEnd); |
| |
| return ParseTemplateDeclarationOrSpecialization(Context, DeclEnd, AS); |
| } |
| |
| /// \brief RAII class that manages the template parameter depth. |
| namespace { |
| class TemplateParameterDepthCounter { |
| unsigned &Depth; |
| unsigned AddedLevels; |
| |
| public: |
| explicit TemplateParameterDepthCounter(unsigned &Depth) |
| : Depth(Depth), AddedLevels(0) { } |
| |
| ~TemplateParameterDepthCounter() { |
| Depth -= AddedLevels; |
| } |
| |
| void operator++() { |
| ++Depth; |
| ++AddedLevels; |
| } |
| |
| operator unsigned() const { return Depth; } |
| }; |
| } |
| |
| /// \brief Parse a template declaration or an explicit specialization. |
| /// |
| /// Template declarations include one or more template parameter lists |
| /// and either the function or class template declaration. Explicit |
| /// specializations contain one or more 'template < >' prefixes |
| /// followed by a (possibly templated) declaration. Since the |
| /// syntactic form of both features is nearly identical, we parse all |
| /// of the template headers together and let semantic analysis sort |
| /// the declarations from the explicit specializations. |
| /// |
| /// template-declaration: [C++ temp] |
| /// 'export'[opt] 'template' '<' template-parameter-list '>' declaration |
| /// |
| /// explicit-specialization: [ C++ temp.expl.spec] |
| /// 'template' '<' '>' declaration |
| Decl * |
| Parser::ParseTemplateDeclarationOrSpecialization(unsigned Context, |
| SourceLocation &DeclEnd, |
| AccessSpecifier AS) { |
| assert((Tok.is(tok::kw_export) || Tok.is(tok::kw_template)) && |
| "Token does not start a template declaration."); |
| |
| // Enter template-parameter scope. |
| ParseScope TemplateParmScope(this, Scope::TemplateParamScope); |
| |
| // Tell the action that names should be checked in the context of |
| // the declaration to come. |
| ParsingDeclRAIIObject ParsingTemplateParams(*this); |
| |
| // Parse multiple levels of template headers within this template |
| // parameter scope, e.g., |
| // |
| // template<typename T> |
| // template<typename U> |
| // class A<T>::B { ... }; |
| // |
| // We parse multiple levels non-recursively so that we can build a |
| // single data structure containing all of the template parameter |
| // lists to easily differentiate between the case above and: |
| // |
| // template<typename T> |
| // class A { |
| // template<typename U> class B; |
| // }; |
| // |
| // In the first case, the action for declaring A<T>::B receives |
| // both template parameter lists. In the second case, the action for |
| // defining A<T>::B receives just the inner template parameter list |
| // (and retrieves the outer template parameter list from its |
| // context). |
| bool isSpecialization = true; |
| bool LastParamListWasEmpty = false; |
| TemplateParameterLists ParamLists; |
| TemplateParameterDepthCounter Depth(TemplateParameterDepth); |
| do { |
| // Consume the 'export', if any. |
| SourceLocation ExportLoc; |
| if (Tok.is(tok::kw_export)) { |
| ExportLoc = ConsumeToken(); |
| } |
| |
| // Consume the 'template', which should be here. |
| SourceLocation TemplateLoc; |
| if (Tok.is(tok::kw_template)) { |
| TemplateLoc = ConsumeToken(); |
| } else { |
| Diag(Tok.getLocation(), diag::err_expected_template); |
| return 0; |
| } |
| |
| // Parse the '<' template-parameter-list '>' |
| SourceLocation LAngleLoc, RAngleLoc; |
| llvm::SmallVector<Decl*, 4> TemplateParams; |
| if (ParseTemplateParameters(Depth, TemplateParams, LAngleLoc, |
| RAngleLoc)) { |
| // Skip until the semi-colon or a }. |
| SkipUntil(tok::r_brace, true, true); |
| if (Tok.is(tok::semi)) |
| ConsumeToken(); |
| return 0; |
| } |
| |
| ParamLists.push_back( |
| Actions.ActOnTemplateParameterList(Depth, ExportLoc, |
| TemplateLoc, LAngleLoc, |
| TemplateParams.data(), |
| TemplateParams.size(), RAngleLoc)); |
| |
| if (!TemplateParams.empty()) { |
| isSpecialization = false; |
| ++Depth; |
| } else { |
| LastParamListWasEmpty = true; |
| } |
| } while (Tok.is(tok::kw_export) || Tok.is(tok::kw_template)); |
| |
| // Parse the actual template declaration. |
| return ParseSingleDeclarationAfterTemplate(Context, |
| ParsedTemplateInfo(&ParamLists, |
| isSpecialization, |
| LastParamListWasEmpty), |
| ParsingTemplateParams, |
| DeclEnd, AS); |
| } |
| |
| /// \brief Parse a single declaration that declares a template, |
| /// template specialization, or explicit instantiation of a template. |
| /// |
| /// \param TemplateParams if non-NULL, the template parameter lists |
| /// that preceded this declaration. In this case, the declaration is a |
| /// template declaration, out-of-line definition of a template, or an |
| /// explicit template specialization. When NULL, the declaration is an |
| /// explicit template instantiation. |
| /// |
| /// \param TemplateLoc when TemplateParams is NULL, the location of |
| /// the 'template' keyword that indicates that we have an explicit |
| /// template instantiation. |
| /// |
| /// \param DeclEnd will receive the source location of the last token |
| /// within this declaration. |
| /// |
| /// \param AS the access specifier associated with this |
| /// declaration. Will be AS_none for namespace-scope declarations. |
| /// |
| /// \returns the new declaration. |
| Decl * |
| Parser::ParseSingleDeclarationAfterTemplate( |
| unsigned Context, |
| const ParsedTemplateInfo &TemplateInfo, |
| ParsingDeclRAIIObject &DiagsFromTParams, |
| SourceLocation &DeclEnd, |
| AccessSpecifier AS) { |
| assert(TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate && |
| "Template information required"); |
| |
| if (Context == Declarator::MemberContext) { |
| // We are parsing a member template. |
| ParseCXXClassMemberDeclaration(AS, TemplateInfo, &DiagsFromTParams); |
| return 0; |
| } |
| |
| ParsedAttributesWithRange prefixAttrs; |
| MaybeParseCXX0XAttributes(prefixAttrs); |
| |
| if (Tok.is(tok::kw_using)) |
| return ParseUsingDirectiveOrDeclaration(Context, TemplateInfo, DeclEnd, |
| prefixAttrs); |
| |
| // Parse the declaration specifiers, stealing the accumulated |
| // diagnostics from the template parameters. |
| ParsingDeclSpec DS(DiagsFromTParams); |
| |
| DS.takeAttributesFrom(prefixAttrs); |
| |
| ParseDeclarationSpecifiers(DS, TemplateInfo, AS, |
| getDeclSpecContextFromDeclaratorContext(Context)); |
| |
| if (Tok.is(tok::semi)) { |
| DeclEnd = ConsumeToken(); |
| Decl *Decl = Actions.ParsedFreeStandingDeclSpec(getCurScope(), AS, DS); |
| DS.complete(Decl); |
| return Decl; |
| } |
| |
| // Parse the declarator. |
| ParsingDeclarator DeclaratorInfo(*this, DS, (Declarator::TheContext)Context); |
| ParseDeclarator(DeclaratorInfo); |
| // Error parsing the declarator? |
| if (!DeclaratorInfo.hasName()) { |
| // If so, skip until the semi-colon or a }. |
| SkipUntil(tok::r_brace, true, true); |
| if (Tok.is(tok::semi)) |
| ConsumeToken(); |
| return 0; |
| } |
| |
| // If we have a declaration or declarator list, handle it. |
| if (isDeclarationAfterDeclarator()) { |
| // Parse this declaration. |
| Decl *ThisDecl = ParseDeclarationAfterDeclarator(DeclaratorInfo, |
| TemplateInfo); |
| |
| if (Tok.is(tok::comma)) { |
| Diag(Tok, diag::err_multiple_template_declarators) |
| << (int)TemplateInfo.Kind; |
| SkipUntil(tok::semi, true, false); |
| return ThisDecl; |
| } |
| |
| // Eat the semi colon after the declaration. |
| ExpectAndConsume(tok::semi, diag::err_expected_semi_declaration); |
| DS.complete(ThisDecl); |
| return ThisDecl; |
| } |
| |
| if (DeclaratorInfo.isFunctionDeclarator() && |
| isStartOfFunctionDefinition(DeclaratorInfo)) { |
| if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) { |
| Diag(Tok, diag::err_function_declared_typedef); |
| |
| if (Tok.is(tok::l_brace)) { |
| // This recovery skips the entire function body. It would be nice |
| // to simply call ParseFunctionDefinition() below, however Sema |
| // assumes the declarator represents a function, not a typedef. |
| ConsumeBrace(); |
| SkipUntil(tok::r_brace, true); |
| } else { |
| SkipUntil(tok::semi); |
| } |
| return 0; |
| } |
| return ParseFunctionDefinition(DeclaratorInfo, TemplateInfo); |
| } |
| |
| if (DeclaratorInfo.isFunctionDeclarator()) |
| Diag(Tok, diag::err_expected_fn_body); |
| else |
| Diag(Tok, diag::err_invalid_token_after_toplevel_declarator); |
| SkipUntil(tok::semi); |
| return 0; |
| } |
| |
| /// ParseTemplateParameters - Parses a template-parameter-list enclosed in |
| /// angle brackets. Depth is the depth of this template-parameter-list, which |
| /// is the number of template headers directly enclosing this template header. |
| /// TemplateParams is the current list of template parameters we're building. |
| /// The template parameter we parse will be added to this list. LAngleLoc and |
| /// RAngleLoc will receive the positions of the '<' and '>', respectively, |
| /// that enclose this template parameter list. |
| /// |
| /// \returns true if an error occurred, false otherwise. |
| bool Parser::ParseTemplateParameters(unsigned Depth, |
| llvm::SmallVectorImpl<Decl*> &TemplateParams, |
| SourceLocation &LAngleLoc, |
| SourceLocation &RAngleLoc) { |
| // Get the template parameter list. |
| if (!Tok.is(tok::less)) { |
| Diag(Tok.getLocation(), diag::err_expected_less_after) << "template"; |
| return true; |
| } |
| LAngleLoc = ConsumeToken(); |
| |
| // Try to parse the template parameter list. |
| if (Tok.is(tok::greater)) |
| RAngleLoc = ConsumeToken(); |
| else if (ParseTemplateParameterList(Depth, TemplateParams)) { |
| if (!Tok.is(tok::greater)) { |
| Diag(Tok.getLocation(), diag::err_expected_greater); |
| return true; |
| } |
| RAngleLoc = ConsumeToken(); |
| } |
| return false; |
| } |
| |
| /// ParseTemplateParameterList - Parse a template parameter list. If |
| /// the parsing fails badly (i.e., closing bracket was left out), this |
| /// will try to put the token stream in a reasonable position (closing |
| /// a statement, etc.) and return false. |
| /// |
| /// template-parameter-list: [C++ temp] |
| /// template-parameter |
| /// template-parameter-list ',' template-parameter |
| bool |
| Parser::ParseTemplateParameterList(unsigned Depth, |
| llvm::SmallVectorImpl<Decl*> &TemplateParams) { |
| while (1) { |
| if (Decl *TmpParam |
| = ParseTemplateParameter(Depth, TemplateParams.size())) { |
| TemplateParams.push_back(TmpParam); |
| } else { |
| // If we failed to parse a template parameter, skip until we find |
| // a comma or closing brace. |
| SkipUntil(tok::comma, tok::greater, true, true); |
| } |
| |
| // Did we find a comma or the end of the template parmeter list? |
| if (Tok.is(tok::comma)) { |
| ConsumeToken(); |
| } else if (Tok.is(tok::greater)) { |
| // Don't consume this... that's done by template parser. |
| break; |
| } else { |
| // Somebody probably forgot to close the template. Skip ahead and |
| // try to get out of the expression. This error is currently |
| // subsumed by whatever goes on in ParseTemplateParameter. |
| // TODO: This could match >>, and it would be nice to avoid those |
| // silly errors with template <vec<T>>. |
| Diag(Tok.getLocation(), diag::err_expected_comma_greater); |
| SkipUntil(tok::greater, true, true); |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /// \brief Determine whether the parser is at the start of a template |
| /// type parameter. |
| bool Parser::isStartOfTemplateTypeParameter() { |
| if (Tok.is(tok::kw_class)) { |
| // "class" may be the start of an elaborated-type-specifier or a |
| // type-parameter. Per C++ [temp.param]p3, we prefer the type-parameter. |
| switch (NextToken().getKind()) { |
| case tok::equal: |
| case tok::comma: |
| case tok::greater: |
| case tok::greatergreater: |
| case tok::ellipsis: |
| return true; |
| |
| case tok::identifier: |
| // This may be either a type-parameter or an elaborated-type-specifier. |
| // We have to look further. |
| break; |
| |
| default: |
| return false; |
| } |
| |
| switch (GetLookAheadToken(2).getKind()) { |
| case tok::equal: |
| case tok::comma: |
| case tok::greater: |
| case tok::greatergreater: |
| return true; |
| |
| default: |
| return false; |
| } |
| } |
| |
| if (Tok.isNot(tok::kw_typename)) |
| return false; |
| |
| // C++ [temp.param]p2: |
| // There is no semantic difference between class and typename in a |
| // template-parameter. typename followed by an unqualified-id |
| // names a template type parameter. typename followed by a |
| // qualified-id denotes the type in a non-type |
| // parameter-declaration. |
| Token Next = NextToken(); |
| |
| // If we have an identifier, skip over it. |
| if (Next.getKind() == tok::identifier) |
| Next = GetLookAheadToken(2); |
| |
| switch (Next.getKind()) { |
| case tok::equal: |
| case tok::comma: |
| case tok::greater: |
| case tok::greatergreater: |
| case tok::ellipsis: |
| return true; |
| |
| default: |
| return false; |
| } |
| } |
| |
| /// ParseTemplateParameter - Parse a template-parameter (C++ [temp.param]). |
| /// |
| /// template-parameter: [C++ temp.param] |
| /// type-parameter |
| /// parameter-declaration |
| /// |
| /// type-parameter: (see below) |
| /// 'class' ...[opt][C++0x] identifier[opt] |
| /// 'class' identifier[opt] '=' type-id |
| /// 'typename' ...[opt][C++0x] identifier[opt] |
| /// 'typename' identifier[opt] '=' type-id |
| /// 'template' ...[opt][C++0x] '<' template-parameter-list '>' 'class' identifier[opt] |
| /// 'template' '<' template-parameter-list '>' 'class' identifier[opt] = id-expression |
| Decl *Parser::ParseTemplateParameter(unsigned Depth, unsigned Position) { |
| if (isStartOfTemplateTypeParameter()) |
| return ParseTypeParameter(Depth, Position); |
| |
| if (Tok.is(tok::kw_template)) |
| return ParseTemplateTemplateParameter(Depth, Position); |
| |
| // If it's none of the above, then it must be a parameter declaration. |
| // NOTE: This will pick up errors in the closure of the template parameter |
| // list (e.g., template < ; Check here to implement >> style closures. |
| return ParseNonTypeTemplateParameter(Depth, Position); |
| } |
| |
| /// ParseTypeParameter - Parse a template type parameter (C++ [temp.param]). |
| /// Other kinds of template parameters are parsed in |
| /// ParseTemplateTemplateParameter and ParseNonTypeTemplateParameter. |
| /// |
| /// type-parameter: [C++ temp.param] |
| /// 'class' ...[opt][C++0x] identifier[opt] |
| /// 'class' identifier[opt] '=' type-id |
| /// 'typename' ...[opt][C++0x] identifier[opt] |
| /// 'typename' identifier[opt] '=' type-id |
| Decl *Parser::ParseTypeParameter(unsigned Depth, unsigned Position) { |
| assert((Tok.is(tok::kw_class) || Tok.is(tok::kw_typename)) && |
| "A type-parameter starts with 'class' or 'typename'"); |
| |
| // Consume the 'class' or 'typename' keyword. |
| bool TypenameKeyword = Tok.is(tok::kw_typename); |
| SourceLocation KeyLoc = ConsumeToken(); |
| |
| // Grab the ellipsis (if given). |
| bool Ellipsis = false; |
| SourceLocation EllipsisLoc; |
| if (Tok.is(tok::ellipsis)) { |
| Ellipsis = true; |
| EllipsisLoc = ConsumeToken(); |
| |
| if (!getLang().CPlusPlus0x) |
| Diag(EllipsisLoc, diag::err_variadic_templates); |
| } |
| |
| // Grab the template parameter name (if given) |
| SourceLocation NameLoc; |
| IdentifierInfo* ParamName = 0; |
| if (Tok.is(tok::identifier)) { |
| ParamName = Tok.getIdentifierInfo(); |
| NameLoc = ConsumeToken(); |
| } else if (Tok.is(tok::equal) || Tok.is(tok::comma) || |
| Tok.is(tok::greater)) { |
| // Unnamed template parameter. Don't have to do anything here, just |
| // don't consume this token. |
| } else { |
| Diag(Tok.getLocation(), diag::err_expected_ident); |
| return 0; |
| } |
| |
| // Grab a default argument (if available). |
| // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before |
| // we introduce the type parameter into the local scope. |
| SourceLocation EqualLoc; |
| ParsedType DefaultArg; |
| if (Tok.is(tok::equal)) { |
| EqualLoc = ConsumeToken(); |
| DefaultArg = ParseTypeName().get(); |
| } |
| |
| return Actions.ActOnTypeParameter(getCurScope(), TypenameKeyword, Ellipsis, |
| EllipsisLoc, KeyLoc, ParamName, NameLoc, |
| Depth, Position, EqualLoc, DefaultArg); |
| } |
| |
| /// ParseTemplateTemplateParameter - Handle the parsing of template |
| /// template parameters. |
| /// |
| /// type-parameter: [C++ temp.param] |
| /// 'template' '<' template-parameter-list '>' 'class' identifier[opt] |
| /// 'template' '<' template-parameter-list '>' 'class' identifier[opt] = id-expression |
| Decl * |
| Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) { |
| assert(Tok.is(tok::kw_template) && "Expected 'template' keyword"); |
| |
| // Handle the template <...> part. |
| SourceLocation TemplateLoc = ConsumeToken(); |
| llvm::SmallVector<Decl*,8> TemplateParams; |
| SourceLocation LAngleLoc, RAngleLoc; |
| { |
| ParseScope TemplateParmScope(this, Scope::TemplateParamScope); |
| if (ParseTemplateParameters(Depth + 1, TemplateParams, LAngleLoc, |
| RAngleLoc)) { |
| return 0; |
| } |
| } |
| |
| // Generate a meaningful error if the user forgot to put class before the |
| // identifier, comma, or greater. |
| if (!Tok.is(tok::kw_class)) { |
| Diag(Tok.getLocation(), diag::err_expected_class_before) |
| << PP.getSpelling(Tok); |
| return 0; |
| } |
| SourceLocation ClassLoc = ConsumeToken(); |
| |
| // Get the identifier, if given. |
| SourceLocation NameLoc; |
| IdentifierInfo* ParamName = 0; |
| if (Tok.is(tok::identifier)) { |
| ParamName = Tok.getIdentifierInfo(); |
| NameLoc = ConsumeToken(); |
| } else if (Tok.is(tok::equal) || Tok.is(tok::comma) || Tok.is(tok::greater)) { |
| // Unnamed template parameter. Don't have to do anything here, just |
| // don't consume this token. |
| } else { |
| Diag(Tok.getLocation(), diag::err_expected_ident); |
| return 0; |
| } |
| |
| TemplateParamsTy *ParamList = |
| Actions.ActOnTemplateParameterList(Depth, SourceLocation(), |
| TemplateLoc, LAngleLoc, |
| TemplateParams.data(), |
| TemplateParams.size(), |
| RAngleLoc); |
| |
| // Grab a default argument (if available). |
| // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before |
| // we introduce the template parameter into the local scope. |
| SourceLocation EqualLoc; |
| ParsedTemplateArgument DefaultArg; |
| if (Tok.is(tok::equal)) { |
| EqualLoc = ConsumeToken(); |
| DefaultArg = ParseTemplateTemplateArgument(); |
| if (DefaultArg.isInvalid()) { |
| Diag(Tok.getLocation(), |
| diag::err_default_template_template_parameter_not_template); |
| static const tok::TokenKind EndToks[] = { |
| tok::comma, tok::greater, tok::greatergreater |
| }; |
| SkipUntil(EndToks, 3, true, true); |
| } |
| } |
| |
| return Actions.ActOnTemplateTemplateParameter(getCurScope(), TemplateLoc, |
| ParamList, ParamName, |
| NameLoc, Depth, Position, |
| EqualLoc, DefaultArg); |
| } |
| |
| /// ParseNonTypeTemplateParameter - Handle the parsing of non-type |
| /// template parameters (e.g., in "template<int Size> class array;"). |
| /// |
| /// template-parameter: |
| /// ... |
| /// parameter-declaration |
| Decl * |
| Parser::ParseNonTypeTemplateParameter(unsigned Depth, unsigned Position) { |
| SourceLocation StartLoc = Tok.getLocation(); |
| |
| // Parse the declaration-specifiers (i.e., the type). |
| // FIXME: The type should probably be restricted in some way... Not all |
| // declarators (parts of declarators?) are accepted for parameters. |
| DeclSpec DS; |
| ParseDeclarationSpecifiers(DS); |
| |
| // Parse this as a typename. |
| Declarator ParamDecl(DS, Declarator::TemplateParamContext); |
| ParseDeclarator(ParamDecl); |
| if (DS.getTypeSpecType() == DeclSpec::TST_unspecified) { |
| // This probably shouldn't happen - and it's more of a Sema thing, but |
| // basically we didn't parse the type name because we couldn't associate |
| // it with an AST node. we should just skip to the comma or greater. |
| // TODO: This is currently a placeholder for some kind of Sema Error. |
| Diag(Tok.getLocation(), diag::err_parse_error); |
| SkipUntil(tok::comma, tok::greater, true, true); |
| return 0; |
| } |
| |
| // If there is a default value, parse it. |
| // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before |
| // we introduce the template parameter into the local scope. |
| SourceLocation EqualLoc; |
| ExprResult DefaultArg; |
| if (Tok.is(tok::equal)) { |
| EqualLoc = ConsumeToken(); |
| |
| // C++ [temp.param]p15: |
| // When parsing a default template-argument for a non-type |
| // template-parameter, the first non-nested > is taken as the |
| // end of the template-parameter-list rather than a greater-than |
| // operator. |
| GreaterThanIsOperatorScope G(GreaterThanIsOperator, false); |
| |
| DefaultArg = ParseAssignmentExpression(); |
| if (DefaultArg.isInvalid()) |
| SkipUntil(tok::comma, tok::greater, true, true); |
| } |
| |
| // Create the parameter. |
| return Actions.ActOnNonTypeTemplateParameter(getCurScope(), ParamDecl, |
| Depth, Position, EqualLoc, |
| DefaultArg.take()); |
| } |
| |
| /// \brief Parses a template-id that after the template name has |
| /// already been parsed. |
| /// |
| /// This routine takes care of parsing the enclosed template argument |
| /// list ('<' template-parameter-list [opt] '>') and placing the |
| /// results into a form that can be transferred to semantic analysis. |
| /// |
| /// \param Template the template declaration produced by isTemplateName |
| /// |
| /// \param TemplateNameLoc the source location of the template name |
| /// |
| /// \param SS if non-NULL, the nested-name-specifier preceding the |
| /// template name. |
| /// |
| /// \param ConsumeLastToken if true, then we will consume the last |
| /// token that forms the template-id. Otherwise, we will leave the |
| /// last token in the stream (e.g., so that it can be replaced with an |
| /// annotation token). |
| bool |
| Parser::ParseTemplateIdAfterTemplateName(TemplateTy Template, |
| SourceLocation TemplateNameLoc, |
| const CXXScopeSpec *SS, |
| bool ConsumeLastToken, |
| SourceLocation &LAngleLoc, |
| TemplateArgList &TemplateArgs, |
| SourceLocation &RAngleLoc) { |
| assert(Tok.is(tok::less) && "Must have already parsed the template-name"); |
| |
| // Consume the '<'. |
| LAngleLoc = ConsumeToken(); |
| |
| // Parse the optional template-argument-list. |
| bool Invalid = false; |
| { |
| GreaterThanIsOperatorScope G(GreaterThanIsOperator, false); |
| if (Tok.isNot(tok::greater)) |
| Invalid = ParseTemplateArgumentList(TemplateArgs); |
| |
| if (Invalid) { |
| // Try to find the closing '>'. |
| SkipUntil(tok::greater, true, !ConsumeLastToken); |
| |
| return true; |
| } |
| } |
| |
| if (Tok.isNot(tok::greater) && Tok.isNot(tok::greatergreater)) { |
| Diag(Tok.getLocation(), diag::err_expected_greater); |
| return true; |
| } |
| |
| // Determine the location of the '>' or '>>'. Only consume this |
| // token if the caller asked us to. |
| RAngleLoc = Tok.getLocation(); |
| |
| if (Tok.is(tok::greatergreater)) { |
| if (!getLang().CPlusPlus0x) { |
| const char *ReplaceStr = "> >"; |
| if (NextToken().is(tok::greater) || NextToken().is(tok::greatergreater)) |
| ReplaceStr = "> > "; |
| |
| Diag(Tok.getLocation(), diag::err_two_right_angle_brackets_need_space) |
| << FixItHint::CreateReplacement( |
| SourceRange(Tok.getLocation()), ReplaceStr); |
| } |
| |
| Tok.setKind(tok::greater); |
| if (!ConsumeLastToken) { |
| // Since we're not supposed to consume the '>>' token, we need |
| // to insert a second '>' token after the first. |
| PP.EnterToken(Tok); |
| } |
| } else if (ConsumeLastToken) |
| ConsumeToken(); |
| |
| return false; |
| } |
| |
| /// \brief Replace the tokens that form a simple-template-id with an |
| /// annotation token containing the complete template-id. |
| /// |
| /// The first token in the stream must be the name of a template that |
| /// is followed by a '<'. This routine will parse the complete |
| /// simple-template-id and replace the tokens with a single annotation |
| /// token with one of two different kinds: if the template-id names a |
| /// type (and \p AllowTypeAnnotation is true), the annotation token is |
| /// a type annotation that includes the optional nested-name-specifier |
| /// (\p SS). Otherwise, the annotation token is a template-id |
| /// annotation that does not include the optional |
| /// nested-name-specifier. |
| /// |
| /// \param Template the declaration of the template named by the first |
| /// token (an identifier), as returned from \c Action::isTemplateName(). |
| /// |
| /// \param TemplateNameKind the kind of template that \p Template |
| /// refers to, as returned from \c Action::isTemplateName(). |
| /// |
| /// \param SS if non-NULL, the nested-name-specifier that precedes |
| /// this template name. |
| /// |
| /// \param TemplateKWLoc if valid, specifies that this template-id |
| /// annotation was preceded by the 'template' keyword and gives the |
| /// location of that keyword. If invalid (the default), then this |
| /// template-id was not preceded by a 'template' keyword. |
| /// |
| /// \param AllowTypeAnnotation if true (the default), then a |
| /// simple-template-id that refers to a class template, template |
| /// template parameter, or other template that produces a type will be |
| /// replaced with a type annotation token. Otherwise, the |
| /// simple-template-id is always replaced with a template-id |
| /// annotation token. |
| /// |
| /// If an unrecoverable parse error occurs and no annotation token can be |
| /// formed, this function returns true. |
| /// |
| bool Parser::AnnotateTemplateIdToken(TemplateTy Template, TemplateNameKind TNK, |
| const CXXScopeSpec *SS, |
| UnqualifiedId &TemplateName, |
| SourceLocation TemplateKWLoc, |
| bool AllowTypeAnnotation) { |
| assert(getLang().CPlusPlus && "Can only annotate template-ids in C++"); |
| assert(Template && Tok.is(tok::less) && |
| "Parser isn't at the beginning of a template-id"); |
| |
| // Consume the template-name. |
| SourceLocation TemplateNameLoc = TemplateName.getSourceRange().getBegin(); |
| |
| // Parse the enclosed template argument list. |
| SourceLocation LAngleLoc, RAngleLoc; |
| TemplateArgList TemplateArgs; |
| bool Invalid = ParseTemplateIdAfterTemplateName(Template, |
| TemplateNameLoc, |
| SS, false, LAngleLoc, |
| TemplateArgs, |
| RAngleLoc); |
| |
| if (Invalid) { |
| // If we failed to parse the template ID but skipped ahead to a >, we're not |
| // going to be able to form a token annotation. Eat the '>' if present. |
| if (Tok.is(tok::greater)) |
| ConsumeToken(); |
| return true; |
| } |
| |
| ASTTemplateArgsPtr TemplateArgsPtr(Actions, TemplateArgs.data(), |
| TemplateArgs.size()); |
| |
| // Build the annotation token. |
| if (TNK == TNK_Type_template && AllowTypeAnnotation) { |
| TypeResult Type |
| = Actions.ActOnTemplateIdType(Template, TemplateNameLoc, |
| LAngleLoc, TemplateArgsPtr, |
| RAngleLoc); |
| if (Type.isInvalid()) { |
| // If we failed to parse the template ID but skipped ahead to a >, we're not |
| // going to be able to form a token annotation. Eat the '>' if present. |
| if (Tok.is(tok::greater)) |
| ConsumeToken(); |
| return true; |
| } |
| |
| Tok.setKind(tok::annot_typename); |
| setTypeAnnotation(Tok, Type.get()); |
| if (SS && SS->isNotEmpty()) |
| Tok.setLocation(SS->getBeginLoc()); |
| else if (TemplateKWLoc.isValid()) |
| Tok.setLocation(TemplateKWLoc); |
| else |
| Tok.setLocation(TemplateNameLoc); |
| } else { |
| // Build a template-id annotation token that can be processed |
| // later. |
| Tok.setKind(tok::annot_template_id); |
| TemplateIdAnnotation *TemplateId |
| = TemplateIdAnnotation::Allocate(TemplateArgs.size()); |
| TemplateId->TemplateNameLoc = TemplateNameLoc; |
| if (TemplateName.getKind() == UnqualifiedId::IK_Identifier) { |
| TemplateId->Name = TemplateName.Identifier; |
| TemplateId->Operator = OO_None; |
| } else { |
| TemplateId->Name = 0; |
| TemplateId->Operator = TemplateName.OperatorFunctionId.Operator; |
| } |
| TemplateId->Template = Template; |
| TemplateId->Kind = TNK; |
| TemplateId->LAngleLoc = LAngleLoc; |
| TemplateId->RAngleLoc = RAngleLoc; |
| ParsedTemplateArgument *Args = TemplateId->getTemplateArgs(); |
| for (unsigned Arg = 0, ArgEnd = TemplateArgs.size(); Arg != ArgEnd; ++Arg) |
| Args[Arg] = TemplateArgs[Arg]; |
| Tok.setAnnotationValue(TemplateId); |
| if (TemplateKWLoc.isValid()) |
| Tok.setLocation(TemplateKWLoc); |
| else |
| Tok.setLocation(TemplateNameLoc); |
| |
| TemplateArgsPtr.release(); |
| } |
| |
| // Common fields for the annotation token |
| Tok.setAnnotationEndLoc(RAngleLoc); |
| |
| // In case the tokens were cached, have Preprocessor replace them with the |
| // annotation token. |
| PP.AnnotateCachedTokens(Tok); |
| return false; |
| } |
| |
| /// \brief Replaces a template-id annotation token with a type |
| /// annotation token. |
| /// |
| /// If there was a failure when forming the type from the template-id, |
| /// a type annotation token will still be created, but will have a |
| /// NULL type pointer to signify an error. |
| void Parser::AnnotateTemplateIdTokenAsType(const CXXScopeSpec *SS) { |
| assert(Tok.is(tok::annot_template_id) && "Requires template-id tokens"); |
| |
| TemplateIdAnnotation *TemplateId |
| = static_cast<TemplateIdAnnotation *>(Tok.getAnnotationValue()); |
| assert((TemplateId->Kind == TNK_Type_template || |
| TemplateId->Kind == TNK_Dependent_template_name) && |
| "Only works for type and dependent templates"); |
| |
| ASTTemplateArgsPtr TemplateArgsPtr(Actions, |
| TemplateId->getTemplateArgs(), |
| TemplateId->NumArgs); |
| |
| TypeResult Type |
| = Actions.ActOnTemplateIdType(TemplateId->Template, |
| TemplateId->TemplateNameLoc, |
| TemplateId->LAngleLoc, |
| TemplateArgsPtr, |
| TemplateId->RAngleLoc); |
| // Create the new "type" annotation token. |
| Tok.setKind(tok::annot_typename); |
| setTypeAnnotation(Tok, Type.isInvalid() ? ParsedType() : Type.get()); |
| if (SS && SS->isNotEmpty()) // it was a C++ qualified type name. |
| Tok.setLocation(SS->getBeginLoc()); |
| // End location stays the same |
| |
| // Replace the template-id annotation token, and possible the scope-specifier |
| // that precedes it, with the typename annotation token. |
| PP.AnnotateCachedTokens(Tok); |
| TemplateId->Destroy(); |
| } |
| |
| /// \brief Determine whether the given token can end a template argument. |
| static bool isEndOfTemplateArgument(Token Tok) { |
| return Tok.is(tok::comma) || Tok.is(tok::greater) || |
| Tok.is(tok::greatergreater); |
| } |
| |
| /// \brief Parse a C++ template template argument. |
| ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() { |
| if (!Tok.is(tok::identifier) && !Tok.is(tok::coloncolon) && |
| !Tok.is(tok::annot_cxxscope)) |
| return ParsedTemplateArgument(); |
| |
| // C++0x [temp.arg.template]p1: |
| // A template-argument for a template template-parameter shall be the name |
| // of a class template or a template alias, expressed as id-expression. |
| // |
| // We parse an id-expression that refers to a class template or template |
| // alias. The grammar we parse is: |
| // |
| // nested-name-specifier[opt] template[opt] identifier |
| // |
| // followed by a token that terminates a template argument, such as ',', |
| // '>', or (in some cases) '>>'. |
| CXXScopeSpec SS; // nested-name-specifier, if present |
| ParseOptionalCXXScopeSpecifier(SS, ParsedType(), |
| /*EnteringContext=*/false); |
| |
| if (SS.isSet() && Tok.is(tok::kw_template)) { |
| // Parse the optional 'template' keyword following the |
| // nested-name-specifier. |
| SourceLocation TemplateLoc = ConsumeToken(); |
| |
| if (Tok.is(tok::identifier)) { |
| // We appear to have a dependent template name. |
| UnqualifiedId Name; |
| Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation()); |
| ConsumeToken(); // the identifier |
| |
| // If the next token signals the end of a template argument, |
| // then we have a dependent template name that could be a template |
| // template argument. |
| TemplateTy Template; |
| if (isEndOfTemplateArgument(Tok) && |
| Actions.ActOnDependentTemplateName(getCurScope(), TemplateLoc, |
| SS, Name, |
| /*ObjectType=*/ ParsedType(), |
| /*EnteringContext=*/false, |
| Template)) |
| return ParsedTemplateArgument(SS, Template, Name.StartLocation); |
| } |
| } else if (Tok.is(tok::identifier)) { |
| // We may have a (non-dependent) template name. |
| TemplateTy Template; |
| UnqualifiedId Name; |
| Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation()); |
| ConsumeToken(); // the identifier |
| |
| if (isEndOfTemplateArgument(Tok)) { |
| bool MemberOfUnknownSpecialization; |
| TemplateNameKind TNK = Actions.isTemplateName(getCurScope(), SS, |
| /*hasTemplateKeyword=*/false, |
| Name, |
| /*ObjectType=*/ ParsedType(), |
| /*EnteringContext=*/false, |
| Template, |
| MemberOfUnknownSpecialization); |
| if (TNK == TNK_Dependent_template_name || TNK == TNK_Type_template) { |
| // We have an id-expression that refers to a class template or |
| // (C++0x) template alias. |
| return ParsedTemplateArgument(SS, Template, Name.StartLocation); |
| } |
| } |
| } |
| |
| // We don't have a template template argument. |
| return ParsedTemplateArgument(); |
| } |
| |
| /// ParseTemplateArgument - Parse a C++ template argument (C++ [temp.names]). |
| /// |
| /// template-argument: [C++ 14.2] |
| /// constant-expression |
| /// type-id |
| /// id-expression |
| ParsedTemplateArgument Parser::ParseTemplateArgument() { |
| // C++ [temp.arg]p2: |
| // In a template-argument, an ambiguity between a type-id and an |
| // expression is resolved to a type-id, regardless of the form of |
| // the corresponding template-parameter. |
| // |
| // Therefore, we initially try to parse a type-id. |
| if (isCXXTypeId(TypeIdAsTemplateArgument)) { |
| SourceLocation Loc = Tok.getLocation(); |
| TypeResult TypeArg = ParseTypeName(); |
| if (TypeArg.isInvalid()) |
| return ParsedTemplateArgument(); |
| |
| return ParsedTemplateArgument(ParsedTemplateArgument::Type, |
| TypeArg.get().getAsOpaquePtr(), |
| Loc); |
| } |
| |
| // Try to parse a template template argument. |
| { |
| TentativeParsingAction TPA(*this); |
| |
| ParsedTemplateArgument TemplateTemplateArgument |
| = ParseTemplateTemplateArgument(); |
| if (!TemplateTemplateArgument.isInvalid()) { |
| TPA.Commit(); |
| return TemplateTemplateArgument; |
| } |
| |
| // Revert this tentative parse to parse a non-type template argument. |
| TPA.Revert(); |
| } |
| |
| // Parse a non-type template argument. |
| SourceLocation Loc = Tok.getLocation(); |
| ExprResult ExprArg = ParseConstantExpression(); |
| if (ExprArg.isInvalid() || !ExprArg.get()) |
| return ParsedTemplateArgument(); |
| |
| return ParsedTemplateArgument(ParsedTemplateArgument::NonType, |
| ExprArg.release(), Loc); |
| } |
| |
| /// \brief Determine whether the current tokens can only be parsed as a |
| /// template argument list (starting with the '<') and never as a '<' |
| /// expression. |
| bool Parser::IsTemplateArgumentList(unsigned Skip) { |
| struct AlwaysRevertAction : TentativeParsingAction { |
| AlwaysRevertAction(Parser &P) : TentativeParsingAction(P) { } |
| ~AlwaysRevertAction() { Revert(); } |
| } Tentative(*this); |
| |
| while (Skip) { |
| ConsumeToken(); |
| --Skip; |
| } |
| |
| // '<' |
| if (!Tok.is(tok::less)) |
| return false; |
| ConsumeToken(); |
| |
| // An empty template argument list. |
| if (Tok.is(tok::greater)) |
| return true; |
| |
| // See whether we have declaration specifiers, which indicate a type. |
| while (isCXXDeclarationSpecifier() == TPResult::True()) |
| ConsumeToken(); |
| |
| // If we have a '>' or a ',' then this is a template argument list. |
| return Tok.is(tok::greater) || Tok.is(tok::comma); |
| } |
| |
| /// ParseTemplateArgumentList - Parse a C++ template-argument-list |
| /// (C++ [temp.names]). Returns true if there was an error. |
| /// |
| /// template-argument-list: [C++ 14.2] |
| /// template-argument |
| /// template-argument-list ',' template-argument |
| bool |
| Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs) { |
| while (true) { |
| ParsedTemplateArgument Arg = ParseTemplateArgument(); |
| if (Tok.is(tok::ellipsis)) { |
| SourceLocation EllipsisLoc = ConsumeToken(); |
| Arg = Actions.ActOnPackExpansion(Arg, EllipsisLoc); |
| } |
| |
| if (Arg.isInvalid()) { |
| SkipUntil(tok::comma, tok::greater, true, true); |
| return true; |
| } |
| |
| // Save this template argument. |
| TemplateArgs.push_back(Arg); |
| |
| // If the next token is a comma, consume it and keep reading |
| // arguments. |
| if (Tok.isNot(tok::comma)) break; |
| |
| // Consume the comma. |
| ConsumeToken(); |
| } |
| |
| return false; |
| } |
| |
| /// \brief Parse a C++ explicit template instantiation |
| /// (C++ [temp.explicit]). |
| /// |
| /// explicit-instantiation: |
| /// 'extern' [opt] 'template' declaration |
| /// |
| /// Note that the 'extern' is a GNU extension and C++0x feature. |
| Decl *Parser::ParseExplicitInstantiation(SourceLocation ExternLoc, |
| SourceLocation TemplateLoc, |
| SourceLocation &DeclEnd) { |
| // This isn't really required here. |
| ParsingDeclRAIIObject ParsingTemplateParams(*this); |
| |
| return ParseSingleDeclarationAfterTemplate(Declarator::FileContext, |
| ParsedTemplateInfo(ExternLoc, |
| TemplateLoc), |
| ParsingTemplateParams, |
| DeclEnd, AS_none); |
| } |
| |
| SourceRange Parser::ParsedTemplateInfo::getSourceRange() const { |
| if (TemplateParams) |
| return getTemplateParamsRange(TemplateParams->data(), |
| TemplateParams->size()); |
| |
| SourceRange R(TemplateLoc); |
| if (ExternLoc.isValid()) |
| R.setBegin(ExternLoc); |
| return R; |
| } |