| //===--- 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/AST/ASTContext.h" |
| #include "clang/AST/DeclTemplate.h" |
| #include "clang/Parse/ParseDiagnostic.h" |
| #include "clang/Parse/Parser.h" |
| #include "clang/Parse/RAIIObjectsForParser.h" |
| #include "clang/Sema/DeclSpec.h" |
| #include "clang/Sema/ParsedTemplate.h" |
| #include "clang/Sema/Scope.h" |
| using namespace clang; |
| |
| /// Parse a template declaration, explicit instantiation, or |
| /// explicit specialization. |
| Decl *Parser::ParseDeclarationStartingWithTemplate( |
| DeclaratorContext Context, SourceLocation &DeclEnd, |
| ParsedAttributes &AccessAttrs, AccessSpecifier AS) { |
| ObjCDeclContextSwitch ObjCDC(*this); |
| |
| if (Tok.is(tok::kw_template) && NextToken().isNot(tok::less)) { |
| return ParseExplicitInstantiation(Context, SourceLocation(), ConsumeToken(), |
| DeclEnd, AccessAttrs, AS); |
| } |
| return ParseTemplateDeclarationOrSpecialization(Context, DeclEnd, AccessAttrs, |
| AS); |
| } |
| |
| /// 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( |
| DeclaratorContext Context, SourceLocation &DeclEnd, |
| ParsedAttributes &AccessAttrs, AccessSpecifier AS) { |
| assert(Tok.isOneOf(tok::kw_export, 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, ParsingDeclRAIIObject::NoParent); |
| |
| // 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; |
| TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth); |
| |
| do { |
| // Consume the 'export', if any. |
| SourceLocation ExportLoc; |
| TryConsumeToken(tok::kw_export, ExportLoc); |
| |
| // Consume the 'template', which should be here. |
| SourceLocation TemplateLoc; |
| if (!TryConsumeToken(tok::kw_template, TemplateLoc)) { |
| Diag(Tok.getLocation(), diag::err_expected_template); |
| return nullptr; |
| } |
| |
| // Parse the '<' template-parameter-list '>' |
| SourceLocation LAngleLoc, RAngleLoc; |
| SmallVector<NamedDecl*, 4> TemplateParams; |
| if (ParseTemplateParameters(CurTemplateDepthTracker.getDepth(), |
| TemplateParams, LAngleLoc, RAngleLoc)) { |
| // Skip until the semi-colon or a '}'. |
| SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch); |
| TryConsumeToken(tok::semi); |
| return nullptr; |
| } |
| |
| ExprResult OptionalRequiresClauseConstraintER; |
| if (!TemplateParams.empty()) { |
| isSpecialization = false; |
| ++CurTemplateDepthTracker; |
| |
| if (TryConsumeToken(tok::kw_requires)) { |
| OptionalRequiresClauseConstraintER = |
| Actions.CorrectDelayedTyposInExpr(ParseConstraintExpression()); |
| if (!OptionalRequiresClauseConstraintER.isUsable()) { |
| // Skip until the semi-colon or a '}'. |
| SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch); |
| TryConsumeToken(tok::semi); |
| return nullptr; |
| } |
| } |
| } else { |
| LastParamListWasEmpty = true; |
| } |
| |
| ParamLists.push_back(Actions.ActOnTemplateParameterList( |
| CurTemplateDepthTracker.getDepth(), ExportLoc, TemplateLoc, LAngleLoc, |
| TemplateParams, RAngleLoc, OptionalRequiresClauseConstraintER.get())); |
| } while (Tok.isOneOf(tok::kw_export, tok::kw_template)); |
| |
| unsigned NewFlags = getCurScope()->getFlags() & ~Scope::TemplateParamScope; |
| ParseScopeFlags TemplateScopeFlags(this, NewFlags, isSpecialization); |
| |
| // Parse the actual template declaration. |
| return ParseSingleDeclarationAfterTemplate( |
| Context, |
| ParsedTemplateInfo(&ParamLists, isSpecialization, LastParamListWasEmpty), |
| ParsingTemplateParams, DeclEnd, AccessAttrs, AS); |
| } |
| |
| /// Parse a single declaration that declares a template, |
| /// template specialization, or explicit instantiation of a template. |
| /// |
| /// \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( |
| DeclaratorContext Context, const ParsedTemplateInfo &TemplateInfo, |
| ParsingDeclRAIIObject &DiagsFromTParams, SourceLocation &DeclEnd, |
| ParsedAttributes &AccessAttrs, AccessSpecifier AS) { |
| assert(TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate && |
| "Template information required"); |
| |
| if (Tok.is(tok::kw_static_assert)) { |
| // A static_assert declaration may not be templated. |
| Diag(Tok.getLocation(), diag::err_templated_invalid_declaration) |
| << TemplateInfo.getSourceRange(); |
| // Parse the static_assert declaration to improve error recovery. |
| return ParseStaticAssertDeclaration(DeclEnd); |
| } |
| |
| if (Context == DeclaratorContext::MemberContext) { |
| // We are parsing a member template. |
| ParseCXXClassMemberDeclaration(AS, AccessAttrs, TemplateInfo, |
| &DiagsFromTParams); |
| return nullptr; |
| } |
| |
| ParsedAttributesWithRange prefixAttrs(AttrFactory); |
| MaybeParseCXX11Attributes(prefixAttrs); |
| |
| if (Tok.is(tok::kw_using)) { |
| auto usingDeclPtr = ParseUsingDirectiveOrDeclaration(Context, TemplateInfo, DeclEnd, |
| prefixAttrs); |
| if (!usingDeclPtr || !usingDeclPtr.get().isSingleDecl()) |
| return nullptr; |
| return usingDeclPtr.get().getSingleDecl(); |
| } |
| |
| // Parse the declaration specifiers, stealing any diagnostics from |
| // the template parameters. |
| ParsingDeclSpec DS(*this, &DiagsFromTParams); |
| |
| ParseDeclarationSpecifiers(DS, TemplateInfo, AS, |
| getDeclSpecContextFromDeclaratorContext(Context)); |
| |
| if (Tok.is(tok::semi)) { |
| ProhibitAttributes(prefixAttrs); |
| DeclEnd = ConsumeToken(); |
| RecordDecl *AnonRecord = nullptr; |
| Decl *Decl = Actions.ParsedFreeStandingDeclSpec( |
| getCurScope(), AS, DS, |
| TemplateInfo.TemplateParams ? *TemplateInfo.TemplateParams |
| : MultiTemplateParamsArg(), |
| TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation, |
| AnonRecord); |
| assert(!AnonRecord && |
| "Anonymous unions/structs should not be valid with template"); |
| DS.complete(Decl); |
| return Decl; |
| } |
| |
| // Move the attributes from the prefix into the DS. |
| if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation) |
| ProhibitAttributes(prefixAttrs); |
| else |
| DS.takeAttributesFrom(prefixAttrs); |
| |
| // Parse the declarator. |
| ParsingDeclarator DeclaratorInfo(*this, DS, (DeclaratorContext)Context); |
| ParseDeclarator(DeclaratorInfo); |
| // Error parsing the declarator? |
| if (!DeclaratorInfo.hasName()) { |
| // If so, skip until the semi-colon or a }. |
| SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch); |
| if (Tok.is(tok::semi)) |
| ConsumeToken(); |
| return nullptr; |
| } |
| |
| LateParsedAttrList LateParsedAttrs(true); |
| if (DeclaratorInfo.isFunctionDeclarator()) |
| MaybeParseGNUAttributes(DeclaratorInfo, &LateParsedAttrs); |
| |
| if (DeclaratorInfo.isFunctionDeclarator() && |
| isStartOfFunctionDefinition(DeclaratorInfo)) { |
| |
| // Function definitions are only allowed at file scope and in C++ classes. |
| // The C++ inline method definition case is handled elsewhere, so we only |
| // need to handle the file scope definition case. |
| if (Context != DeclaratorContext::FileContext) { |
| Diag(Tok, diag::err_function_definition_not_allowed); |
| SkipMalformedDecl(); |
| return nullptr; |
| } |
| |
| if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) { |
| // Recover by ignoring the 'typedef'. This was probably supposed to be |
| // the 'typename' keyword, which we should have already suggested adding |
| // if it's appropriate. |
| Diag(DS.getStorageClassSpecLoc(), diag::err_function_declared_typedef) |
| << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc()); |
| DS.ClearStorageClassSpecs(); |
| } |
| |
| if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation) { |
| if (DeclaratorInfo.getName().getKind() != |
| UnqualifiedIdKind::IK_TemplateId) { |
| // If the declarator-id is not a template-id, issue a diagnostic and |
| // recover by ignoring the 'template' keyword. |
| Diag(Tok, diag::err_template_defn_explicit_instantiation) << 0; |
| return ParseFunctionDefinition(DeclaratorInfo, ParsedTemplateInfo(), |
| &LateParsedAttrs); |
| } else { |
| SourceLocation LAngleLoc |
| = PP.getLocForEndOfToken(TemplateInfo.TemplateLoc); |
| Diag(DeclaratorInfo.getIdentifierLoc(), |
| diag::err_explicit_instantiation_with_definition) |
| << SourceRange(TemplateInfo.TemplateLoc) |
| << FixItHint::CreateInsertion(LAngleLoc, "<>"); |
| |
| // Recover as if it were an explicit specialization. |
| TemplateParameterLists FakedParamLists; |
| FakedParamLists.push_back(Actions.ActOnTemplateParameterList( |
| 0, SourceLocation(), TemplateInfo.TemplateLoc, LAngleLoc, None, |
| LAngleLoc, nullptr)); |
| |
| return ParseFunctionDefinition( |
| DeclaratorInfo, ParsedTemplateInfo(&FakedParamLists, |
| /*isSpecialization=*/true, |
| /*LastParamListWasEmpty=*/true), |
| &LateParsedAttrs); |
| } |
| } |
| return ParseFunctionDefinition(DeclaratorInfo, TemplateInfo, |
| &LateParsedAttrs); |
| } |
| |
| // 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); |
| return ThisDecl; |
| } |
| |
| // Eat the semi colon after the declaration. |
| ExpectAndConsumeSemi(diag::err_expected_semi_declaration); |
| if (LateParsedAttrs.size() > 0) |
| ParseLexedAttributeList(LateParsedAttrs, ThisDecl, true, false); |
| DeclaratorInfo.complete(ThisDecl); |
| return ThisDecl; |
| } |
| |
| /// 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, SmallVectorImpl<NamedDecl *> &TemplateParams, |
| SourceLocation &LAngleLoc, SourceLocation &RAngleLoc) { |
| // Get the template parameter list. |
| if (!TryConsumeToken(tok::less, LAngleLoc)) { |
| Diag(Tok.getLocation(), diag::err_expected_less_after) << "template"; |
| return true; |
| } |
| |
| // Try to parse the template parameter list. |
| bool Failed = false; |
| if (!Tok.is(tok::greater) && !Tok.is(tok::greatergreater)) |
| Failed = ParseTemplateParameterList(Depth, TemplateParams); |
| |
| if (Tok.is(tok::greatergreater)) { |
| // No diagnostic required here: a template-parameter-list can only be |
| // followed by a declaration or, for a template template parameter, the |
| // 'class' keyword. Therefore, the second '>' will be diagnosed later. |
| // This matters for elegant diagnosis of: |
| // template<template<typename>> struct S; |
| Tok.setKind(tok::greater); |
| RAngleLoc = Tok.getLocation(); |
| Tok.setLocation(Tok.getLocation().getLocWithOffset(1)); |
| } else if (!TryConsumeToken(tok::greater, RAngleLoc) && Failed) { |
| Diag(Tok.getLocation(), diag::err_expected) << tok::greater; |
| return true; |
| } |
| 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(const unsigned Depth, |
| SmallVectorImpl<NamedDecl*> &TemplateParams) { |
| while (1) { |
| |
| if (NamedDecl *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, tok::greatergreater, |
| StopAtSemi | StopBeforeMatch); |
| } |
| |
| // Did we find a comma or the end of the template parameter list? |
| if (Tok.is(tok::comma)) { |
| ConsumeToken(); |
| } else if (Tok.isOneOf(tok::greater, tok::greatergreater)) { |
| // 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. |
| Diag(Tok.getLocation(), diag::err_expected_comma_greater); |
| SkipUntil(tok::comma, tok::greater, tok::greatergreater, |
| StopAtSemi | StopBeforeMatch); |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /// 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; |
| } |
| } |
| |
| // 'typedef' is a reasonably-common typo/thinko for 'typename', and is |
| // ill-formed otherwise. |
| if (Tok.isNot(tok::kw_typename) && Tok.isNot(tok::kw_typedef)) |
| 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; |
| |
| case tok::kw_typename: |
| case tok::kw_typedef: |
| case tok::kw_class: |
| // These indicate that a comma was missed after a type parameter, not that |
| // we have found a non-type parameter. |
| 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] identifier[opt] |
| /// 'class' identifier[opt] '=' type-id |
| /// 'typename' ...[opt] identifier[opt] |
| /// 'typename' identifier[opt] '=' type-id |
| /// 'template' '<' template-parameter-list '>' |
| /// 'class' ...[opt] identifier[opt] |
| /// 'template' '<' template-parameter-list '>' 'class' identifier[opt] |
| /// = id-expression |
| NamedDecl *Parser::ParseTemplateParameter(unsigned Depth, unsigned Position) { |
| if (isStartOfTemplateTypeParameter()) { |
| // Is there just a typo in the input code? ('typedef' instead of 'typename') |
| if (Tok.is(tok::kw_typedef)) { |
| Diag(Tok.getLocation(), diag::err_expected_template_parameter); |
| |
| Diag(Tok.getLocation(), diag::note_meant_to_use_typename) |
| << FixItHint::CreateReplacement(CharSourceRange::getCharRange( |
| Tok.getLocation(), Tok.getEndLoc()), |
| "typename"); |
| |
| Tok.setKind(tok::kw_typename); |
| } |
| |
| 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 |
| NamedDecl *Parser::ParseTypeParameter(unsigned Depth, unsigned Position) { |
| assert(Tok.isOneOf(tok::kw_class, 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). |
| SourceLocation EllipsisLoc; |
| if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) { |
| Diag(EllipsisLoc, |
| getLangOpts().CPlusPlus11 |
| ? diag::warn_cxx98_compat_variadic_templates |
| : diag::ext_variadic_templates); |
| } |
| |
| // Grab the template parameter name (if given) |
| SourceLocation NameLoc; |
| IdentifierInfo *ParamName = nullptr; |
| if (Tok.is(tok::identifier)) { |
| ParamName = Tok.getIdentifierInfo(); |
| NameLoc = ConsumeToken(); |
| } else if (Tok.isOneOf(tok::equal, tok::comma, tok::greater, |
| tok::greatergreater)) { |
| // Unnamed template parameter. Don't have to do anything here, just |
| // don't consume this token. |
| } else { |
| Diag(Tok.getLocation(), diag::err_expected) << tok::identifier; |
| return nullptr; |
| } |
| |
| // Recover from misplaced ellipsis. |
| bool AlreadyHasEllipsis = EllipsisLoc.isValid(); |
| if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) |
| DiagnoseMisplacedEllipsis(EllipsisLoc, NameLoc, AlreadyHasEllipsis, true); |
| |
| // 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 (TryConsumeToken(tok::equal, EqualLoc)) |
| DefaultArg = ParseTypeName(/*Range=*/nullptr, |
| DeclaratorContext::TemplateTypeArgContext).get(); |
| |
| return Actions.ActOnTypeParameter(getCurScope(), TypenameKeyword, 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 '>' type-parameter-key |
| /// ...[opt] identifier[opt] |
| /// 'template' '<' template-parameter-list '>' type-parameter-key |
| /// identifier[opt] = id-expression |
| /// type-parameter-key: |
| /// 'class' |
| /// 'typename' [C++1z] |
| NamedDecl * |
| Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) { |
| assert(Tok.is(tok::kw_template) && "Expected 'template' keyword"); |
| |
| // Handle the template <...> part. |
| SourceLocation TemplateLoc = ConsumeToken(); |
| SmallVector<NamedDecl*,8> TemplateParams; |
| SourceLocation LAngleLoc, RAngleLoc; |
| { |
| ParseScope TemplateParmScope(this, Scope::TemplateParamScope); |
| if (ParseTemplateParameters(Depth + 1, TemplateParams, LAngleLoc, |
| RAngleLoc)) { |
| return nullptr; |
| } |
| } |
| |
| // Provide an ExtWarn if the C++1z feature of using 'typename' here is used. |
| // Generate a meaningful error if the user forgot to put class before the |
| // identifier, comma, or greater. Provide a fixit if the identifier, comma, |
| // or greater appear immediately or after 'struct'. In the latter case, |
| // replace the keyword with 'class'. |
| if (!TryConsumeToken(tok::kw_class)) { |
| bool Replace = Tok.isOneOf(tok::kw_typename, tok::kw_struct); |
| const Token &Next = Tok.is(tok::kw_struct) ? NextToken() : Tok; |
| if (Tok.is(tok::kw_typename)) { |
| Diag(Tok.getLocation(), |
| getLangOpts().CPlusPlus17 |
| ? diag::warn_cxx14_compat_template_template_param_typename |
| : diag::ext_template_template_param_typename) |
| << (!getLangOpts().CPlusPlus17 |
| ? FixItHint::CreateReplacement(Tok.getLocation(), "class") |
| : FixItHint()); |
| } else if (Next.isOneOf(tok::identifier, tok::comma, tok::greater, |
| tok::greatergreater, tok::ellipsis)) { |
| Diag(Tok.getLocation(), diag::err_class_on_template_template_param) |
| << (Replace ? FixItHint::CreateReplacement(Tok.getLocation(), "class") |
| : FixItHint::CreateInsertion(Tok.getLocation(), "class ")); |
| } else |
| Diag(Tok.getLocation(), diag::err_class_on_template_template_param); |
| |
| if (Replace) |
| ConsumeToken(); |
| } |
| |
| // Parse the ellipsis, if given. |
| SourceLocation EllipsisLoc; |
| if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) |
| Diag(EllipsisLoc, |
| getLangOpts().CPlusPlus11 |
| ? diag::warn_cxx98_compat_variadic_templates |
| : diag::ext_variadic_templates); |
| |
| // Get the identifier, if given. |
| SourceLocation NameLoc; |
| IdentifierInfo *ParamName = nullptr; |
| if (Tok.is(tok::identifier)) { |
| ParamName = Tok.getIdentifierInfo(); |
| NameLoc = ConsumeToken(); |
| } else if (Tok.isOneOf(tok::equal, tok::comma, tok::greater, |
| tok::greatergreater)) { |
| // Unnamed template parameter. Don't have to do anything here, just |
| // don't consume this token. |
| } else { |
| Diag(Tok.getLocation(), diag::err_expected) << tok::identifier; |
| return nullptr; |
| } |
| |
| // Recover from misplaced ellipsis. |
| bool AlreadyHasEllipsis = EllipsisLoc.isValid(); |
| if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) |
| DiagnoseMisplacedEllipsis(EllipsisLoc, NameLoc, AlreadyHasEllipsis, true); |
| |
| TemplateParameterList *ParamList = |
| Actions.ActOnTemplateParameterList(Depth, SourceLocation(), |
| TemplateLoc, LAngleLoc, |
| TemplateParams, |
| RAngleLoc, nullptr); |
| |
| // 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 (TryConsumeToken(tok::equal, EqualLoc)) { |
| DefaultArg = ParseTemplateTemplateArgument(); |
| if (DefaultArg.isInvalid()) { |
| Diag(Tok.getLocation(), |
| diag::err_default_template_template_parameter_not_template); |
| SkipUntil(tok::comma, tok::greater, tok::greatergreater, |
| StopAtSemi | StopBeforeMatch); |
| } |
| } |
| |
| return Actions.ActOnTemplateTemplateParameter(getCurScope(), TemplateLoc, |
| ParamList, EllipsisLoc, |
| 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 |
| NamedDecl * |
| Parser::ParseNonTypeTemplateParameter(unsigned Depth, unsigned Position) { |
| // 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(AttrFactory); |
| ParseDeclarationSpecifiers(DS, ParsedTemplateInfo(), AS_none, |
| DeclSpecContext::DSC_template_param); |
| |
| // Parse this as a typename. |
| Declarator ParamDecl(DS, DeclaratorContext::TemplateParamContext); |
| ParseDeclarator(ParamDecl); |
| if (DS.getTypeSpecType() == DeclSpec::TST_unspecified) { |
| Diag(Tok.getLocation(), diag::err_expected_template_parameter); |
| return nullptr; |
| } |
| |
| // Recover from misplaced ellipsis. |
| SourceLocation EllipsisLoc; |
| if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) |
| DiagnoseMisplacedEllipsisInDeclarator(EllipsisLoc, ParamDecl); |
| |
| // 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 (TryConsumeToken(tok::equal, EqualLoc)) { |
| // 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); |
| EnterExpressionEvaluationContext ConstantEvaluated( |
| Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated); |
| |
| DefaultArg = Actions.CorrectDelayedTyposInExpr(ParseAssignmentExpression()); |
| if (DefaultArg.isInvalid()) |
| SkipUntil(tok::comma, tok::greater, StopAtSemi | StopBeforeMatch); |
| } |
| |
| // Create the parameter. |
| return Actions.ActOnNonTypeTemplateParameter(getCurScope(), ParamDecl, |
| Depth, Position, EqualLoc, |
| DefaultArg.get()); |
| } |
| |
| void Parser::DiagnoseMisplacedEllipsis(SourceLocation EllipsisLoc, |
| SourceLocation CorrectLoc, |
| bool AlreadyHasEllipsis, |
| bool IdentifierHasName) { |
| FixItHint Insertion; |
| if (!AlreadyHasEllipsis) |
| Insertion = FixItHint::CreateInsertion(CorrectLoc, "..."); |
| Diag(EllipsisLoc, diag::err_misplaced_ellipsis_in_declaration) |
| << FixItHint::CreateRemoval(EllipsisLoc) << Insertion |
| << !IdentifierHasName; |
| } |
| |
| void Parser::DiagnoseMisplacedEllipsisInDeclarator(SourceLocation EllipsisLoc, |
| Declarator &D) { |
| assert(EllipsisLoc.isValid()); |
| bool AlreadyHasEllipsis = D.getEllipsisLoc().isValid(); |
| if (!AlreadyHasEllipsis) |
| D.setEllipsisLoc(EllipsisLoc); |
| DiagnoseMisplacedEllipsis(EllipsisLoc, D.getIdentifierLoc(), |
| AlreadyHasEllipsis, D.hasName()); |
| } |
| |
| /// Parses a '>' at the end of a template list. |
| /// |
| /// If this function encounters '>>', '>>>', '>=', or '>>=', it tries |
| /// to determine if these tokens were supposed to be a '>' followed by |
| /// '>', '>>', '>=', or '>='. It emits an appropriate diagnostic if necessary. |
| /// |
| /// \param RAngleLoc the location of the consumed '>'. |
| /// |
| /// \param ConsumeLastToken if true, the '>' is consumed. |
| /// |
| /// \param ObjCGenericList if true, this is the '>' closing an Objective-C |
| /// type parameter or type argument list, rather than a C++ template parameter |
| /// or argument list. |
| /// |
| /// \returns true, if current token does not start with '>', false otherwise. |
| bool Parser::ParseGreaterThanInTemplateList(SourceLocation &RAngleLoc, |
| bool ConsumeLastToken, |
| bool ObjCGenericList) { |
| // What will be left once we've consumed the '>'. |
| tok::TokenKind RemainingToken; |
| const char *ReplacementStr = "> >"; |
| bool MergeWithNextToken = false; |
| |
| switch (Tok.getKind()) { |
| default: |
| Diag(Tok.getLocation(), diag::err_expected) << tok::greater; |
| return true; |
| |
| case tok::greater: |
| // Determine the location of the '>' token. Only consume this token |
| // if the caller asked us to. |
| RAngleLoc = Tok.getLocation(); |
| if (ConsumeLastToken) |
| ConsumeToken(); |
| return false; |
| |
| case tok::greatergreater: |
| RemainingToken = tok::greater; |
| break; |
| |
| case tok::greatergreatergreater: |
| RemainingToken = tok::greatergreater; |
| break; |
| |
| case tok::greaterequal: |
| RemainingToken = tok::equal; |
| ReplacementStr = "> ="; |
| |
| // Join two adjacent '=' tokens into one, for cases like: |
| // void (*p)() = f<int>; |
| // return f<int>==p; |
| if (NextToken().is(tok::equal) && |
| areTokensAdjacent(Tok, NextToken())) { |
| RemainingToken = tok::equalequal; |
| MergeWithNextToken = true; |
| } |
| break; |
| |
| case tok::greatergreaterequal: |
| RemainingToken = tok::greaterequal; |
| break; |
| } |
| |
| // This template-id is terminated by a token that starts with a '>'. |
| // Outside C++11 and Objective-C, this is now error recovery. |
| // |
| // C++11 allows this when the token is '>>', and in CUDA + C++11 mode, we |
| // extend that treatment to also apply to the '>>>' token. |
| // |
| // Objective-C allows this in its type parameter / argument lists. |
| |
| SourceLocation TokBeforeGreaterLoc = PrevTokLocation; |
| SourceLocation TokLoc = Tok.getLocation(); |
| Token Next = NextToken(); |
| |
| // Whether splitting the current token after the '>' would undesirably result |
| // in the remaining token pasting with the token after it. This excludes the |
| // MergeWithNextToken cases, which we've already handled. |
| bool PreventMergeWithNextToken = |
| (RemainingToken == tok::greater || |
| RemainingToken == tok::greatergreater) && |
| (Next.isOneOf(tok::greater, tok::greatergreater, |
| tok::greatergreatergreater, tok::equal, tok::greaterequal, |
| tok::greatergreaterequal, tok::equalequal)) && |
| areTokensAdjacent(Tok, Next); |
| |
| // Diagnose this situation as appropriate. |
| if (!ObjCGenericList) { |
| // The source range of the replaced token(s). |
| CharSourceRange ReplacementRange = CharSourceRange::getCharRange( |
| TokLoc, Lexer::AdvanceToTokenCharacter(TokLoc, 2, PP.getSourceManager(), |
| getLangOpts())); |
| |
| // A hint to put a space between the '>>'s. In order to make the hint as |
| // clear as possible, we include the characters either side of the space in |
| // the replacement, rather than just inserting a space at SecondCharLoc. |
| FixItHint Hint1 = FixItHint::CreateReplacement(ReplacementRange, |
| ReplacementStr); |
| |
| // A hint to put another space after the token, if it would otherwise be |
| // lexed differently. |
| FixItHint Hint2; |
| if (PreventMergeWithNextToken) |
| Hint2 = FixItHint::CreateInsertion(Next.getLocation(), " "); |
| |
| unsigned DiagId = diag::err_two_right_angle_brackets_need_space; |
| if (getLangOpts().CPlusPlus11 && |
| (Tok.is(tok::greatergreater) || Tok.is(tok::greatergreatergreater))) |
| DiagId = diag::warn_cxx98_compat_two_right_angle_brackets; |
| else if (Tok.is(tok::greaterequal)) |
| DiagId = diag::err_right_angle_bracket_equal_needs_space; |
| Diag(TokLoc, DiagId) << Hint1 << Hint2; |
| } |
| |
| // Find the "length" of the resulting '>' token. This is not always 1, as it |
| // can contain escaped newlines. |
| unsigned GreaterLength = Lexer::getTokenPrefixLength( |
| TokLoc, 1, PP.getSourceManager(), getLangOpts()); |
| |
| // Annotate the source buffer to indicate that we split the token after the |
| // '>'. This allows us to properly find the end of, and extract the spelling |
| // of, the '>' token later. |
| RAngleLoc = PP.SplitToken(TokLoc, GreaterLength); |
| |
| // Strip the initial '>' from the token. |
| bool CachingTokens = PP.IsPreviousCachedToken(Tok); |
| |
| Token Greater = Tok; |
| Greater.setLocation(RAngleLoc); |
| Greater.setKind(tok::greater); |
| Greater.setLength(GreaterLength); |
| |
| unsigned OldLength = Tok.getLength(); |
| if (MergeWithNextToken) { |
| ConsumeToken(); |
| OldLength += Tok.getLength(); |
| } |
| |
| Tok.setKind(RemainingToken); |
| Tok.setLength(OldLength - GreaterLength); |
| |
| // Split the second token if lexing it normally would lex a different token |
| // (eg, the fifth token in 'A<B>>>' should re-lex as '>', not '>>'). |
| SourceLocation AfterGreaterLoc = TokLoc.getLocWithOffset(GreaterLength); |
| if (PreventMergeWithNextToken) |
| AfterGreaterLoc = PP.SplitToken(AfterGreaterLoc, Tok.getLength()); |
| Tok.setLocation(AfterGreaterLoc); |
| |
| // Update the token cache to match what we just did if necessary. |
| if (CachingTokens) { |
| // If the previous cached token is being merged, delete it. |
| if (MergeWithNextToken) |
| PP.ReplacePreviousCachedToken({}); |
| |
| if (ConsumeLastToken) |
| PP.ReplacePreviousCachedToken({Greater, Tok}); |
| else |
| PP.ReplacePreviousCachedToken({Greater}); |
| } |
| |
| if (ConsumeLastToken) { |
| PrevTokLocation = RAngleLoc; |
| } else { |
| PrevTokLocation = TokBeforeGreaterLoc; |
| PP.EnterToken(Tok); |
| Tok = Greater; |
| } |
| |
| return false; |
| } |
| |
| |
| /// 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 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(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.isOneOf(tok::greater, tok::greatergreater, |
| tok::greatergreatergreater, tok::greaterequal, |
| tok::greatergreaterequal)) |
| Invalid = ParseTemplateArgumentList(TemplateArgs); |
| |
| if (Invalid) { |
| // Try to find the closing '>'. |
| if (ConsumeLastToken) |
| SkipUntil(tok::greater, StopAtSemi); |
| else |
| SkipUntil(tok::greater, StopAtSemi | StopBeforeMatch); |
| return true; |
| } |
| } |
| |
| return ParseGreaterThanInTemplateList(RAngleLoc, ConsumeLastToken, |
| /*ObjCGenericList=*/false); |
| } |
| |
| /// 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 TNK 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, |
| CXXScopeSpec &SS, |
| SourceLocation TemplateKWLoc, |
| UnqualifiedId &TemplateName, |
| bool AllowTypeAnnotation) { |
| assert(getLangOpts().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(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. |
| TryConsumeToken(tok::greater); |
| return true; |
| } |
| |
| ASTTemplateArgsPtr TemplateArgsPtr(TemplateArgs); |
| |
| // Build the annotation token. |
| if (TNK == TNK_Type_template && AllowTypeAnnotation) { |
| TypeResult Type = Actions.ActOnTemplateIdType( |
| SS, TemplateKWLoc, Template, TemplateName.Identifier, |
| 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. |
| TryConsumeToken(tok::greater); |
| return true; |
| } |
| |
| Tok.setKind(tok::annot_typename); |
| setTypeAnnotation(Tok, Type.get()); |
| if (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); |
| |
| IdentifierInfo *TemplateII = |
| TemplateName.getKind() == UnqualifiedIdKind::IK_Identifier |
| ? TemplateName.Identifier |
| : nullptr; |
| |
| OverloadedOperatorKind OpKind = |
| TemplateName.getKind() == UnqualifiedIdKind::IK_Identifier |
| ? OO_None |
| : TemplateName.OperatorFunctionId.Operator; |
| |
| TemplateIdAnnotation *TemplateId = TemplateIdAnnotation::Create( |
| SS, TemplateKWLoc, TemplateNameLoc, TemplateII, OpKind, Template, TNK, |
| LAngleLoc, RAngleLoc, TemplateArgs, TemplateIds); |
| |
| Tok.setAnnotationValue(TemplateId); |
| if (TemplateKWLoc.isValid()) |
| Tok.setLocation(TemplateKWLoc); |
| else |
| Tok.setLocation(TemplateNameLoc); |
| } |
| |
| // 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; |
| } |
| |
| /// 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. |
| /// |
| /// \param IsClassName Is this template-id appearing in a context where we |
| /// know it names a class, such as in an elaborated-type-specifier or |
| /// base-specifier? ('typename' and 'template' are unneeded and disallowed |
| /// in those contexts.) |
| void Parser::AnnotateTemplateIdTokenAsType(bool IsClassName) { |
| assert(Tok.is(tok::annot_template_id) && "Requires template-id tokens"); |
| |
| TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok); |
| assert((TemplateId->Kind == TNK_Type_template || |
| TemplateId->Kind == TNK_Dependent_template_name) && |
| "Only works for type and dependent templates"); |
| |
| ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(), |
| TemplateId->NumArgs); |
| |
| TypeResult Type |
| = Actions.ActOnTemplateIdType(TemplateId->SS, |
| TemplateId->TemplateKWLoc, |
| TemplateId->Template, |
| TemplateId->Name, |
| TemplateId->TemplateNameLoc, |
| TemplateId->LAngleLoc, |
| TemplateArgsPtr, |
| TemplateId->RAngleLoc, |
| /*IsCtorOrDtorName*/false, |
| IsClassName); |
| // Create the new "type" annotation token. |
| Tok.setKind(tok::annot_typename); |
| setTypeAnnotation(Tok, Type.isInvalid() ? nullptr : Type.get()); |
| if (TemplateId->SS.isNotEmpty()) // it was a C++ qualified type name. |
| Tok.setLocation(TemplateId->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); |
| } |
| |
| /// Determine whether the given token can end a template argument. |
| static bool isEndOfTemplateArgument(Token Tok) { |
| return Tok.isOneOf(tok::comma, tok::greater, tok::greatergreater); |
| } |
| |
| /// 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 an alias template, expressed as id-expression. |
| // |
| // We parse an id-expression that refers to a class template or alias |
| // template. The grammar we parse is: |
| // |
| // nested-name-specifier[opt] template[opt] identifier ...[opt] |
| // |
| // followed by a token that terminates a template argument, such as ',', |
| // '>', or (in some cases) '>>'. |
| CXXScopeSpec SS; // nested-name-specifier, if present |
| ParseOptionalCXXScopeSpecifier(SS, nullptr, |
| /*EnteringContext=*/false); |
| |
| ParsedTemplateArgument Result; |
| SourceLocation EllipsisLoc; |
| if (SS.isSet() && Tok.is(tok::kw_template)) { |
| // Parse the optional 'template' keyword following the |
| // nested-name-specifier. |
| SourceLocation TemplateKWLoc = 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 |
| |
| TryConsumeToken(tok::ellipsis, EllipsisLoc); |
| |
| // 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(), SS, TemplateKWLoc, Name, |
| /*ObjectType=*/nullptr, |
| /*EnteringContext=*/false, Template)) |
| Result = 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 |
| |
| TryConsumeToken(tok::ellipsis, EllipsisLoc); |
| |
| if (isEndOfTemplateArgument(Tok)) { |
| bool MemberOfUnknownSpecialization; |
| TemplateNameKind TNK = Actions.isTemplateName( |
| getCurScope(), SS, |
| /*hasTemplateKeyword=*/false, Name, |
| /*ObjectType=*/nullptr, |
| /*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) alias template. |
| Result = ParsedTemplateArgument(SS, Template, Name.StartLocation); |
| } |
| } |
| } |
| |
| // If this is a pack expansion, build it as such. |
| if (EllipsisLoc.isValid() && !Result.isInvalid()) |
| Result = Actions.ActOnPackExpansion(Result, EllipsisLoc); |
| |
| return Result; |
| } |
| |
| /// 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 - and isCXXTypeId might look |
| // up and annotate an identifier as an id-expression during disambiguation, |
| // so enter the appropriate context for a constant expression template |
| // argument before trying to disambiguate. |
| |
| EnterExpressionEvaluationContext EnterConstantEvaluated( |
| Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated, |
| /*LambdaContextDecl=*/nullptr, |
| /*ExprContext=*/Sema::ExpressionEvaluationContextRecord::EK_TemplateArgument); |
| if (isCXXTypeId(TypeIdAsTemplateArgument)) { |
| TypeResult TypeArg = ParseTypeName( |
| /*Range=*/nullptr, DeclaratorContext::TemplateArgContext); |
| return Actions.ActOnTemplateTypeArgument(TypeArg); |
| } |
| |
| // 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 = ParseConstantExpressionInExprEvalContext(MaybeTypeCast); |
| if (ExprArg.isInvalid() || !ExprArg.get()) |
| return ParsedTemplateArgument(); |
| |
| return ParsedTemplateArgument(ParsedTemplateArgument::NonType, |
| ExprArg.get(), Loc); |
| } |
| |
| /// 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) { |
| ConsumeAnyToken(); |
| --Skip; |
| } |
| |
| // '<' |
| if (!TryConsumeToken(tok::less)) |
| return false; |
| |
| // 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) |
| ConsumeAnyToken(); |
| |
| // If we have a '>' or a ',' then this is a template argument list. |
| return Tok.isOneOf(tok::greater, 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) { |
| |
| ColonProtectionRAIIObject ColonProtection(*this, false); |
| |
| do { |
| ParsedTemplateArgument Arg = ParseTemplateArgument(); |
| SourceLocation EllipsisLoc; |
| if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) |
| Arg = Actions.ActOnPackExpansion(Arg, EllipsisLoc); |
| |
| if (Arg.isInvalid()) { |
| SkipUntil(tok::comma, tok::greater, StopAtSemi | StopBeforeMatch); |
| return true; |
| } |
| |
| // Save this template argument. |
| TemplateArgs.push_back(Arg); |
| |
| // If the next token is a comma, consume it and keep reading |
| // arguments. |
| } while (TryConsumeToken(tok::comma)); |
| |
| return false; |
| } |
| |
| /// 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++11 feature. |
| Decl *Parser::ParseExplicitInstantiation(DeclaratorContext Context, |
| SourceLocation ExternLoc, |
| SourceLocation TemplateLoc, |
| SourceLocation &DeclEnd, |
| ParsedAttributes &AccessAttrs, |
| AccessSpecifier AS) { |
| // This isn't really required here. |
| ParsingDeclRAIIObject |
| ParsingTemplateParams(*this, ParsingDeclRAIIObject::NoParent); |
| |
| return ParseSingleDeclarationAfterTemplate( |
| Context, ParsedTemplateInfo(ExternLoc, TemplateLoc), |
| ParsingTemplateParams, DeclEnd, AccessAttrs, AS); |
| } |
| |
| SourceRange Parser::ParsedTemplateInfo::getSourceRange() const { |
| if (TemplateParams) |
| return getTemplateParamsRange(TemplateParams->data(), |
| TemplateParams->size()); |
| |
| SourceRange R(TemplateLoc); |
| if (ExternLoc.isValid()) |
| R.setBegin(ExternLoc); |
| return R; |
| } |
| |
| void Parser::LateTemplateParserCallback(void *P, LateParsedTemplate &LPT) { |
| ((Parser *)P)->ParseLateTemplatedFuncDef(LPT); |
| } |
| |
| /// Late parse a C++ function template in Microsoft mode. |
| void Parser::ParseLateTemplatedFuncDef(LateParsedTemplate &LPT) { |
| if (!LPT.D) |
| return; |
| |
| // Get the FunctionDecl. |
| FunctionDecl *FunD = LPT.D->getAsFunction(); |
| // Track template parameter depth. |
| TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth); |
| |
| // To restore the context after late parsing. |
| Sema::ContextRAII GlobalSavedContext( |
| Actions, Actions.Context.getTranslationUnitDecl()); |
| |
| SmallVector<ParseScope*, 4> TemplateParamScopeStack; |
| |
| // Get the list of DeclContexts to reenter. |
| SmallVector<DeclContext*, 4> DeclContextsToReenter; |
| DeclContext *DD = FunD; |
| while (DD && !DD->isTranslationUnit()) { |
| DeclContextsToReenter.push_back(DD); |
| DD = DD->getLexicalParent(); |
| } |
| |
| // Reenter template scopes from outermost to innermost. |
| SmallVectorImpl<DeclContext *>::reverse_iterator II = |
| DeclContextsToReenter.rbegin(); |
| for (; II != DeclContextsToReenter.rend(); ++II) { |
| TemplateParamScopeStack.push_back(new ParseScope(this, |
| Scope::TemplateParamScope)); |
| unsigned NumParamLists = |
| Actions.ActOnReenterTemplateScope(getCurScope(), cast<Decl>(*II)); |
| CurTemplateDepthTracker.addDepth(NumParamLists); |
| if (*II != FunD) { |
| TemplateParamScopeStack.push_back(new ParseScope(this, Scope::DeclScope)); |
| Actions.PushDeclContext(Actions.getCurScope(), *II); |
| } |
| } |
| |
| assert(!LPT.Toks.empty() && "Empty body!"); |
| |
| // Append the current token at the end of the new token stream so that it |
| // doesn't get lost. |
| LPT.Toks.push_back(Tok); |
| PP.EnterTokenStream(LPT.Toks, true); |
| |
| // Consume the previously pushed token. |
| ConsumeAnyToken(/*ConsumeCodeCompletionTok=*/true); |
| assert(Tok.isOneOf(tok::l_brace, tok::colon, tok::kw_try) && |
| "Inline method not starting with '{', ':' or 'try'"); |
| |
| // Parse the method body. Function body parsing code is similar enough |
| // to be re-used for method bodies as well. |
| ParseScope FnScope(this, Scope::FnScope | Scope::DeclScope | |
| Scope::CompoundStmtScope); |
| |
| // Recreate the containing function DeclContext. |
| Sema::ContextRAII FunctionSavedContext(Actions, |
| Actions.getContainingDC(FunD)); |
| |
| Actions.ActOnStartOfFunctionDef(getCurScope(), FunD); |
| |
| if (Tok.is(tok::kw_try)) { |
| ParseFunctionTryBlock(LPT.D, FnScope); |
| } else { |
| if (Tok.is(tok::colon)) |
| ParseConstructorInitializer(LPT.D); |
| else |
| Actions.ActOnDefaultCtorInitializers(LPT.D); |
| |
| if (Tok.is(tok::l_brace)) { |
| assert((!isa<FunctionTemplateDecl>(LPT.D) || |
| cast<FunctionTemplateDecl>(LPT.D) |
| ->getTemplateParameters() |
| ->getDepth() == TemplateParameterDepth - 1) && |
| "TemplateParameterDepth should be greater than the depth of " |
| "current template being instantiated!"); |
| ParseFunctionStatementBody(LPT.D, FnScope); |
| Actions.UnmarkAsLateParsedTemplate(FunD); |
| } else |
| Actions.ActOnFinishFunctionBody(LPT.D, nullptr); |
| } |
| |
| // Exit scopes. |
| FnScope.Exit(); |
| SmallVectorImpl<ParseScope *>::reverse_iterator I = |
| TemplateParamScopeStack.rbegin(); |
| for (; I != TemplateParamScopeStack.rend(); ++I) |
| delete *I; |
| } |
| |
| /// Lex a delayed template function for late parsing. |
| void Parser::LexTemplateFunctionForLateParsing(CachedTokens &Toks) { |
| tok::TokenKind kind = Tok.getKind(); |
| if (!ConsumeAndStoreFunctionPrologue(Toks)) { |
| // Consume everything up to (and including) the matching right brace. |
| ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false); |
| } |
| |
| // If we're in a function-try-block, we need to store all the catch blocks. |
| if (kind == tok::kw_try) { |
| while (Tok.is(tok::kw_catch)) { |
| ConsumeAndStoreUntil(tok::l_brace, Toks, /*StopAtSemi=*/false); |
| ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false); |
| } |
| } |
| } |
| |
| /// We've parsed something that could plausibly be intended to be a template |
| /// name (\p LHS) followed by a '<' token, and the following code can't possibly |
| /// be an expression. Determine if this is likely to be a template-id and if so, |
| /// diagnose it. |
| bool Parser::diagnoseUnknownTemplateId(ExprResult LHS, SourceLocation Less) { |
| TentativeParsingAction TPA(*this); |
| // FIXME: We could look at the token sequence in a lot more detail here. |
| if (SkipUntil(tok::greater, tok::greatergreater, tok::greatergreatergreater, |
| StopAtSemi | StopBeforeMatch)) { |
| TPA.Commit(); |
| |
| SourceLocation Greater; |
| ParseGreaterThanInTemplateList(Greater, true, false); |
| Actions.diagnoseExprIntendedAsTemplateName(getCurScope(), LHS, |
| Less, Greater); |
| return true; |
| } |
| |
| // There's no matching '>' token, this probably isn't supposed to be |
| // interpreted as a template-id. Parse it as an (ill-formed) comparison. |
| TPA.Revert(); |
| return false; |
| } |
| |
| void Parser::checkPotentialAngleBracket(ExprResult &PotentialTemplateName) { |
| assert(Tok.is(tok::less) && "not at a potential angle bracket"); |
| |
| bool DependentTemplateName = false; |
| if (!Actions.mightBeIntendedToBeTemplateName(PotentialTemplateName, |
| DependentTemplateName)) |
| return; |
| |
| // OK, this might be a name that the user intended to be parsed as a |
| // template-name, followed by a '<' token. Check for some easy cases. |
| |
| // If we have potential_template<>, then it's supposed to be a template-name. |
| if (NextToken().is(tok::greater) || |
| (getLangOpts().CPlusPlus11 && |
| NextToken().isOneOf(tok::greatergreater, tok::greatergreatergreater))) { |
| SourceLocation Less = ConsumeToken(); |
| SourceLocation Greater; |
| ParseGreaterThanInTemplateList(Greater, true, false); |
| Actions.diagnoseExprIntendedAsTemplateName( |
| getCurScope(), PotentialTemplateName, Less, Greater); |
| // FIXME: Perform error recovery. |
| PotentialTemplateName = ExprError(); |
| return; |
| } |
| |
| // If we have 'potential_template<type-id', assume it's supposed to be a |
| // template-name if there's a matching '>' later on. |
| { |
| // FIXME: Avoid the tentative parse when NextToken() can't begin a type. |
| TentativeParsingAction TPA(*this); |
| SourceLocation Less = ConsumeToken(); |
| if (isTypeIdUnambiguously() && |
| diagnoseUnknownTemplateId(PotentialTemplateName, Less)) { |
| TPA.Commit(); |
| // FIXME: Perform error recovery. |
| PotentialTemplateName = ExprError(); |
| return; |
| } |
| TPA.Revert(); |
| } |
| |
| // Otherwise, remember that we saw this in case we see a potentially-matching |
| // '>' token later on. |
| AngleBracketTracker::Priority Priority = |
| (DependentTemplateName ? AngleBracketTracker::DependentName |
| : AngleBracketTracker::PotentialTypo) | |
| (Tok.hasLeadingSpace() ? AngleBracketTracker::SpaceBeforeLess |
| : AngleBracketTracker::NoSpaceBeforeLess); |
| AngleBrackets.add(*this, PotentialTemplateName.get(), Tok.getLocation(), |
| Priority); |
| } |
| |
| bool Parser::checkPotentialAngleBracketDelimiter( |
| const AngleBracketTracker::Loc &LAngle, const Token &OpToken) { |
| // If a comma in an expression context is followed by a type that can be a |
| // template argument and cannot be an expression, then this is ill-formed, |
| // but might be intended to be part of a template-id. |
| if (OpToken.is(tok::comma) && isTypeIdUnambiguously() && |
| diagnoseUnknownTemplateId(LAngle.TemplateName, LAngle.LessLoc)) { |
| AngleBrackets.clear(*this); |
| return true; |
| } |
| |
| // If a context that looks like a template-id is followed by '()', then |
| // this is ill-formed, but might be intended to be a template-id |
| // followed by '()'. |
| if (OpToken.is(tok::greater) && Tok.is(tok::l_paren) && |
| NextToken().is(tok::r_paren)) { |
| Actions.diagnoseExprIntendedAsTemplateName( |
| getCurScope(), LAngle.TemplateName, LAngle.LessLoc, |
| OpToken.getLocation()); |
| AngleBrackets.clear(*this); |
| return true; |
| } |
| |
| // After a '>' (etc), we're no longer potentially in a construct that's |
| // intended to be treated as a template-id. |
| if (OpToken.is(tok::greater) || |
| (getLangOpts().CPlusPlus11 && |
| OpToken.isOneOf(tok::greatergreater, tok::greatergreatergreater))) |
| AngleBrackets.clear(*this); |
| return false; |
| } |