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Diffstat (limited to 'contrib/llvm/tools/clang/lib/Parse/ParseTemplate.cpp')
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diff --git a/contrib/llvm/tools/clang/lib/Parse/ParseTemplate.cpp b/contrib/llvm/tools/clang/lib/Parse/ParseTemplate.cpp new file mode 100644 index 0000000..c87ddad --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Parse/ParseTemplate.cpp @@ -0,0 +1,1046 @@ +//===--- 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/Parse/DeclSpec.h" +#include "clang/Parse/Scope.h" +#include "clang/Parse/Template.h" +#include "RAIIObjectsForParser.h" +using namespace clang; + +/// \brief Parse a template declaration, explicit instantiation, or +/// explicit specialization. +Parser::DeclPtrTy +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 +Parser::DeclPtrTy +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); + + // 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 DeclPtrTy(); + } + + // Parse the '<' template-parameter-list '>' + SourceLocation LAngleLoc, RAngleLoc; + TemplateParameterList 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 DeclPtrTy(); + } + + 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), + 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. +Parser::DeclPtrTy +Parser::ParseSingleDeclarationAfterTemplate( + unsigned Context, + const ParsedTemplateInfo &TemplateInfo, + 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); + return DeclPtrTy::make((void*)0); + } + + // Parse the declaration specifiers. + ParsingDeclSpec DS(*this); + + if (getLang().CPlusPlus0x && isCXX0XAttributeSpecifier()) + DS.AddAttributes(ParseCXX0XAttributes().AttrList); + + ParseDeclarationSpecifiers(DS, TemplateInfo, AS, + getDeclSpecContextFromDeclaratorContext(Context)); + + if (Tok.is(tok::semi)) { + DeclEnd = ConsumeToken(); + DeclPtrTy Decl = Actions.ParsedFreeStandingDeclSpec(CurScope, 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 DeclPtrTy(); + } + + // If we have a declaration or declarator list, handle it. + if (isDeclarationAfterDeclarator()) { + // Parse this declaration. + DeclPtrTy 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()) { + 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 DeclPtrTy(); + } + 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 DeclPtrTy(); +} + +/// 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, + TemplateParameterList &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, + TemplateParameterList &TemplateParams) { + while (1) { + if (DeclPtrTy 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)) + return true; + + 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 +Parser::DeclPtrTy +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 +Parser::DeclPtrTy 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 DeclPtrTy(); + } + + DeclPtrTy TypeParam = Actions.ActOnTypeParameter(CurScope, TypenameKeyword, + Ellipsis, EllipsisLoc, + KeyLoc, ParamName, NameLoc, + Depth, Position); + + // Grab a default type id (if given). + if (Tok.is(tok::equal)) { + SourceLocation EqualLoc = ConsumeToken(); + SourceLocation DefaultLoc = Tok.getLocation(); + TypeResult DefaultType = ParseTypeName(); + if (!DefaultType.isInvalid()) + Actions.ActOnTypeParameterDefault(TypeParam, EqualLoc, DefaultLoc, + DefaultType.get()); + } + + return TypeParam; +} + +/// 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 +Parser::DeclPtrTy +Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) { + assert(Tok.is(tok::kw_template) && "Expected 'template' keyword"); + + // Handle the template <...> part. + SourceLocation TemplateLoc = ConsumeToken(); + TemplateParameterList TemplateParams; + SourceLocation LAngleLoc, RAngleLoc; + { + ParseScope TemplateParmScope(this, Scope::TemplateParamScope); + if (ParseTemplateParameters(Depth + 1, TemplateParams, LAngleLoc, + RAngleLoc)) { + return DeclPtrTy(); + } + } + + // 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 DeclPtrTy(); + } + 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 DeclPtrTy(); + } + + TemplateParamsTy *ParamList = + Actions.ActOnTemplateParameterList(Depth, SourceLocation(), + TemplateLoc, LAngleLoc, + &TemplateParams[0], + TemplateParams.size(), + RAngleLoc); + + Parser::DeclPtrTy Param + = Actions.ActOnTemplateTemplateParameter(CurScope, TemplateLoc, + ParamList, ParamName, + NameLoc, Depth, Position); + + // Get the a default value, if given. + if (Tok.is(tok::equal)) { + SourceLocation EqualLoc = ConsumeToken(); + ParsedTemplateArgument Default = ParseTemplateTemplateArgument(); + if (Default.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 Param; + } else if (Param) + Actions.ActOnTemplateTemplateParameterDefault(Param, EqualLoc, Default); + } + + return Param; +} + +/// ParseNonTypeTemplateParameter - Handle the parsing of non-type +/// template parameters (e.g., in "template<int Size> class array;"). +/// +/// template-parameter: +/// ... +/// parameter-declaration +/// +/// NOTE: It would be ideal to simply call out to ParseParameterDeclaration(), +/// but that didn't work out to well. Instead, this tries to recrate the basic +/// parsing of parameter declarations, but tries to constrain it for template +/// parameters. +/// FIXME: We need to make a ParseParameterDeclaration that works for +/// non-type template parameters and normal function parameters. +Parser::DeclPtrTy +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 && !DS.getTypeRep()) { + // 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 DeclPtrTy(); + } + + // Create the parameter. + DeclPtrTy Param = Actions.ActOnNonTypeTemplateParameter(CurScope, ParamDecl, + Depth, Position); + + // If there is a default value, parse it. + if (Tok.is(tok::equal)) { + SourceLocation 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); + + OwningExprResult DefaultArg = ParseAssignmentExpression(); + if (DefaultArg.isInvalid()) + SkipUntil(tok::comma, tok::greater, true, true); + else if (Param) + Actions.ActOnNonTypeTemplateParameterDefault(Param, EqualLoc, + move(DefaultArg)); + } + + return Param; +} + +/// \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) { + Action::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); + Tok.setAnnotationValue(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.getAs<void*>(); + 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); + + Action::TypeResult Type + = Actions.ActOnTemplateIdType(TemplateTy::make(TemplateId->Template), + TemplateId->TemplateNameLoc, + TemplateId->LAngleLoc, + TemplateArgsPtr, + TemplateId->RAngleLoc); + // Create the new "type" annotation token. + Tok.setKind(tok::annot_typename); + Tok.setAnnotationValue(Type.isInvalid()? 0 : 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, /*ObjectType=*/0, + /*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. + if (isEndOfTemplateArgument(Tok)) { + TemplateTy Template + = Actions.ActOnDependentTemplateName(TemplateLoc, SS, Name, + /*ObjectType=*/0, + /*EnteringContext=*/false); + if (Template.get()) + 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(CurScope, SS, Name, + /*ObjectType=*/0, + /*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(), + 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(); + OwningExprResult 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 (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. +Parser::DeclPtrTy +Parser::ParseExplicitInstantiation(SourceLocation ExternLoc, + SourceLocation TemplateLoc, + SourceLocation &DeclEnd) { + return ParseSingleDeclarationAfterTemplate(Declarator::FileContext, + ParsedTemplateInfo(ExternLoc, + TemplateLoc), + DeclEnd, AS_none); +} |
