1 //===--- ParseTemplate.cpp - Template Parsing -----------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements parsing of C++ templates.
12 //===----------------------------------------------------------------------===//
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/DeclTemplate.h"
16 #include "clang/Parse/ParseDiagnostic.h"
17 #include "clang/Parse/Parser.h"
18 #include "clang/Parse/RAIIObjectsForParser.h"
19 #include "clang/Sema/DeclSpec.h"
20 #include "clang/Sema/ParsedTemplate.h"
21 #include "clang/Sema/Scope.h"
22 using namespace clang;
24 /// Parse a template declaration, explicit instantiation, or
25 /// explicit specialization.
26 Decl *Parser::ParseDeclarationStartingWithTemplate(
27 DeclaratorContext Context, SourceLocation &DeclEnd,
28 ParsedAttributes &AccessAttrs, AccessSpecifier AS) {
29 ObjCDeclContextSwitch ObjCDC(*this);
31 if (Tok.is(tok::kw_template) && NextToken().isNot(tok::less)) {
32 return ParseExplicitInstantiation(Context, SourceLocation(), ConsumeToken(),
33 DeclEnd, AccessAttrs, AS);
35 return ParseTemplateDeclarationOrSpecialization(Context, DeclEnd, AccessAttrs,
39 /// Parse a template declaration or an explicit specialization.
41 /// Template declarations include one or more template parameter lists
42 /// and either the function or class template declaration. Explicit
43 /// specializations contain one or more 'template < >' prefixes
44 /// followed by a (possibly templated) declaration. Since the
45 /// syntactic form of both features is nearly identical, we parse all
46 /// of the template headers together and let semantic analysis sort
47 /// the declarations from the explicit specializations.
49 /// template-declaration: [C++ temp]
50 /// 'export'[opt] 'template' '<' template-parameter-list '>' declaration
52 /// explicit-specialization: [ C++ temp.expl.spec]
53 /// 'template' '<' '>' declaration
54 Decl *Parser::ParseTemplateDeclarationOrSpecialization(
55 DeclaratorContext Context, SourceLocation &DeclEnd,
56 ParsedAttributes &AccessAttrs, AccessSpecifier AS) {
57 assert(Tok.isOneOf(tok::kw_export, tok::kw_template) &&
58 "Token does not start a template declaration.");
60 // Enter template-parameter scope.
61 ParseScope TemplateParmScope(this, Scope::TemplateParamScope);
63 // Tell the action that names should be checked in the context of
64 // the declaration to come.
66 ParsingTemplateParams(*this, ParsingDeclRAIIObject::NoParent);
68 // Parse multiple levels of template headers within this template
69 // parameter scope, e.g.,
71 // template<typename T>
72 // template<typename U>
73 // class A<T>::B { ... };
75 // We parse multiple levels non-recursively so that we can build a
76 // single data structure containing all of the template parameter
77 // lists to easily differentiate between the case above and:
79 // template<typename T>
81 // template<typename U> class B;
84 // In the first case, the action for declaring A<T>::B receives
85 // both template parameter lists. In the second case, the action for
86 // defining A<T>::B receives just the inner template parameter list
87 // (and retrieves the outer template parameter list from its
89 bool isSpecialization = true;
90 bool LastParamListWasEmpty = false;
91 TemplateParameterLists ParamLists;
92 TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
95 // Consume the 'export', if any.
96 SourceLocation ExportLoc;
97 TryConsumeToken(tok::kw_export, ExportLoc);
99 // Consume the 'template', which should be here.
100 SourceLocation TemplateLoc;
101 if (!TryConsumeToken(tok::kw_template, TemplateLoc)) {
102 Diag(Tok.getLocation(), diag::err_expected_template);
106 // Parse the '<' template-parameter-list '>'
107 SourceLocation LAngleLoc, RAngleLoc;
108 SmallVector<NamedDecl*, 4> TemplateParams;
109 if (ParseTemplateParameters(CurTemplateDepthTracker.getDepth(),
110 TemplateParams, LAngleLoc, RAngleLoc)) {
111 // Skip until the semi-colon or a '}'.
112 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
113 TryConsumeToken(tok::semi);
117 ExprResult OptionalRequiresClauseConstraintER;
118 if (!TemplateParams.empty()) {
119 isSpecialization = false;
120 ++CurTemplateDepthTracker;
122 if (TryConsumeToken(tok::kw_requires)) {
123 OptionalRequiresClauseConstraintER =
124 Actions.CorrectDelayedTyposInExpr(ParseConstraintExpression());
125 if (!OptionalRequiresClauseConstraintER.isUsable()) {
126 // Skip until the semi-colon or a '}'.
127 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
128 TryConsumeToken(tok::semi);
133 LastParamListWasEmpty = true;
136 ParamLists.push_back(Actions.ActOnTemplateParameterList(
137 CurTemplateDepthTracker.getDepth(), ExportLoc, TemplateLoc, LAngleLoc,
138 TemplateParams, RAngleLoc, OptionalRequiresClauseConstraintER.get()));
139 } while (Tok.isOneOf(tok::kw_export, tok::kw_template));
141 unsigned NewFlags = getCurScope()->getFlags() & ~Scope::TemplateParamScope;
142 ParseScopeFlags TemplateScopeFlags(this, NewFlags, isSpecialization);
144 // Parse the actual template declaration.
145 return ParseSingleDeclarationAfterTemplate(
147 ParsedTemplateInfo(&ParamLists, isSpecialization, LastParamListWasEmpty),
148 ParsingTemplateParams, DeclEnd, AccessAttrs, AS);
151 /// Parse a single declaration that declares a template,
152 /// template specialization, or explicit instantiation of a template.
154 /// \param DeclEnd will receive the source location of the last token
155 /// within this declaration.
157 /// \param AS the access specifier associated with this
158 /// declaration. Will be AS_none for namespace-scope declarations.
160 /// \returns the new declaration.
161 Decl *Parser::ParseSingleDeclarationAfterTemplate(
162 DeclaratorContext Context, const ParsedTemplateInfo &TemplateInfo,
163 ParsingDeclRAIIObject &DiagsFromTParams, SourceLocation &DeclEnd,
164 ParsedAttributes &AccessAttrs, AccessSpecifier AS) {
165 assert(TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate &&
166 "Template information required");
168 if (Tok.is(tok::kw_static_assert)) {
169 // A static_assert declaration may not be templated.
170 Diag(Tok.getLocation(), diag::err_templated_invalid_declaration)
171 << TemplateInfo.getSourceRange();
172 // Parse the static_assert declaration to improve error recovery.
173 return ParseStaticAssertDeclaration(DeclEnd);
176 if (Context == DeclaratorContext::MemberContext) {
177 // We are parsing a member template.
178 ParseCXXClassMemberDeclaration(AS, AccessAttrs, TemplateInfo,
183 ParsedAttributesWithRange prefixAttrs(AttrFactory);
184 MaybeParseCXX11Attributes(prefixAttrs);
186 if (Tok.is(tok::kw_using)) {
187 auto usingDeclPtr = ParseUsingDirectiveOrDeclaration(Context, TemplateInfo, DeclEnd,
189 if (!usingDeclPtr || !usingDeclPtr.get().isSingleDecl())
191 return usingDeclPtr.get().getSingleDecl();
194 // Parse the declaration specifiers, stealing any diagnostics from
195 // the template parameters.
196 ParsingDeclSpec DS(*this, &DiagsFromTParams);
198 ParseDeclarationSpecifiers(DS, TemplateInfo, AS,
199 getDeclSpecContextFromDeclaratorContext(Context));
201 if (Tok.is(tok::semi)) {
202 ProhibitAttributes(prefixAttrs);
203 DeclEnd = ConsumeToken();
204 RecordDecl *AnonRecord = nullptr;
205 Decl *Decl = Actions.ParsedFreeStandingDeclSpec(
206 getCurScope(), AS, DS,
207 TemplateInfo.TemplateParams ? *TemplateInfo.TemplateParams
208 : MultiTemplateParamsArg(),
209 TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation,
211 assert(!AnonRecord &&
212 "Anonymous unions/structs should not be valid with template");
217 // Move the attributes from the prefix into the DS.
218 if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation)
219 ProhibitAttributes(prefixAttrs);
221 DS.takeAttributesFrom(prefixAttrs);
223 // Parse the declarator.
224 ParsingDeclarator DeclaratorInfo(*this, DS, (DeclaratorContext)Context);
225 ParseDeclarator(DeclaratorInfo);
226 // Error parsing the declarator?
227 if (!DeclaratorInfo.hasName()) {
228 // If so, skip until the semi-colon or a }.
229 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
230 if (Tok.is(tok::semi))
235 LateParsedAttrList LateParsedAttrs(true);
236 if (DeclaratorInfo.isFunctionDeclarator())
237 MaybeParseGNUAttributes(DeclaratorInfo, &LateParsedAttrs);
239 if (DeclaratorInfo.isFunctionDeclarator() &&
240 isStartOfFunctionDefinition(DeclaratorInfo)) {
242 // Function definitions are only allowed at file scope and in C++ classes.
243 // The C++ inline method definition case is handled elsewhere, so we only
244 // need to handle the file scope definition case.
245 if (Context != DeclaratorContext::FileContext) {
246 Diag(Tok, diag::err_function_definition_not_allowed);
251 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) {
252 // Recover by ignoring the 'typedef'. This was probably supposed to be
253 // the 'typename' keyword, which we should have already suggested adding
254 // if it's appropriate.
255 Diag(DS.getStorageClassSpecLoc(), diag::err_function_declared_typedef)
256 << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
257 DS.ClearStorageClassSpecs();
260 if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation) {
261 if (DeclaratorInfo.getName().getKind() !=
262 UnqualifiedIdKind::IK_TemplateId) {
263 // If the declarator-id is not a template-id, issue a diagnostic and
264 // recover by ignoring the 'template' keyword.
265 Diag(Tok, diag::err_template_defn_explicit_instantiation) << 0;
266 return ParseFunctionDefinition(DeclaratorInfo, ParsedTemplateInfo(),
269 SourceLocation LAngleLoc
270 = PP.getLocForEndOfToken(TemplateInfo.TemplateLoc);
271 Diag(DeclaratorInfo.getIdentifierLoc(),
272 diag::err_explicit_instantiation_with_definition)
273 << SourceRange(TemplateInfo.TemplateLoc)
274 << FixItHint::CreateInsertion(LAngleLoc, "<>");
276 // Recover as if it were an explicit specialization.
277 TemplateParameterLists FakedParamLists;
278 FakedParamLists.push_back(Actions.ActOnTemplateParameterList(
279 0, SourceLocation(), TemplateInfo.TemplateLoc, LAngleLoc, None,
280 LAngleLoc, nullptr));
282 return ParseFunctionDefinition(
283 DeclaratorInfo, ParsedTemplateInfo(&FakedParamLists,
284 /*isSpecialization=*/true,
285 /*LastParamListWasEmpty=*/true),
289 return ParseFunctionDefinition(DeclaratorInfo, TemplateInfo,
293 // Parse this declaration.
294 Decl *ThisDecl = ParseDeclarationAfterDeclarator(DeclaratorInfo,
297 if (Tok.is(tok::comma)) {
298 Diag(Tok, diag::err_multiple_template_declarators)
299 << (int)TemplateInfo.Kind;
300 SkipUntil(tok::semi);
304 // Eat the semi colon after the declaration.
305 ExpectAndConsumeSemi(diag::err_expected_semi_declaration);
306 if (LateParsedAttrs.size() > 0)
307 ParseLexedAttributeList(LateParsedAttrs, ThisDecl, true, false);
308 DeclaratorInfo.complete(ThisDecl);
312 /// ParseTemplateParameters - Parses a template-parameter-list enclosed in
313 /// angle brackets. Depth is the depth of this template-parameter-list, which
314 /// is the number of template headers directly enclosing this template header.
315 /// TemplateParams is the current list of template parameters we're building.
316 /// The template parameter we parse will be added to this list. LAngleLoc and
317 /// RAngleLoc will receive the positions of the '<' and '>', respectively,
318 /// that enclose this template parameter list.
320 /// \returns true if an error occurred, false otherwise.
321 bool Parser::ParseTemplateParameters(
322 unsigned Depth, SmallVectorImpl<NamedDecl *> &TemplateParams,
323 SourceLocation &LAngleLoc, SourceLocation &RAngleLoc) {
324 // Get the template parameter list.
325 if (!TryConsumeToken(tok::less, LAngleLoc)) {
326 Diag(Tok.getLocation(), diag::err_expected_less_after) << "template";
330 // Try to parse the template parameter list.
332 if (!Tok.is(tok::greater) && !Tok.is(tok::greatergreater))
333 Failed = ParseTemplateParameterList(Depth, TemplateParams);
335 if (Tok.is(tok::greatergreater)) {
336 // No diagnostic required here: a template-parameter-list can only be
337 // followed by a declaration or, for a template template parameter, the
338 // 'class' keyword. Therefore, the second '>' will be diagnosed later.
339 // This matters for elegant diagnosis of:
340 // template<template<typename>> struct S;
341 Tok.setKind(tok::greater);
342 RAngleLoc = Tok.getLocation();
343 Tok.setLocation(Tok.getLocation().getLocWithOffset(1));
344 } else if (!TryConsumeToken(tok::greater, RAngleLoc) && Failed) {
345 Diag(Tok.getLocation(), diag::err_expected) << tok::greater;
351 /// ParseTemplateParameterList - Parse a template parameter list. If
352 /// the parsing fails badly (i.e., closing bracket was left out), this
353 /// will try to put the token stream in a reasonable position (closing
354 /// a statement, etc.) and return false.
356 /// template-parameter-list: [C++ temp]
357 /// template-parameter
358 /// template-parameter-list ',' template-parameter
360 Parser::ParseTemplateParameterList(const unsigned Depth,
361 SmallVectorImpl<NamedDecl*> &TemplateParams) {
364 if (NamedDecl *TmpParam
365 = ParseTemplateParameter(Depth, TemplateParams.size())) {
366 TemplateParams.push_back(TmpParam);
368 // If we failed to parse a template parameter, skip until we find
369 // a comma or closing brace.
370 SkipUntil(tok::comma, tok::greater, tok::greatergreater,
371 StopAtSemi | StopBeforeMatch);
374 // Did we find a comma or the end of the template parameter list?
375 if (Tok.is(tok::comma)) {
377 } else if (Tok.isOneOf(tok::greater, tok::greatergreater)) {
378 // Don't consume this... that's done by template parser.
381 // Somebody probably forgot to close the template. Skip ahead and
382 // try to get out of the expression. This error is currently
383 // subsumed by whatever goes on in ParseTemplateParameter.
384 Diag(Tok.getLocation(), diag::err_expected_comma_greater);
385 SkipUntil(tok::comma, tok::greater, tok::greatergreater,
386 StopAtSemi | StopBeforeMatch);
393 /// Determine whether the parser is at the start of a template
395 bool Parser::isStartOfTemplateTypeParameter() {
396 if (Tok.is(tok::kw_class)) {
397 // "class" may be the start of an elaborated-type-specifier or a
398 // type-parameter. Per C++ [temp.param]p3, we prefer the type-parameter.
399 switch (NextToken().getKind()) {
403 case tok::greatergreater:
407 case tok::identifier:
408 // This may be either a type-parameter or an elaborated-type-specifier.
409 // We have to look further.
416 switch (GetLookAheadToken(2).getKind()) {
420 case tok::greatergreater:
428 if (Tok.isNot(tok::kw_typename))
431 // C++ [temp.param]p2:
432 // There is no semantic difference between class and typename in a
433 // template-parameter. typename followed by an unqualified-id
434 // names a template type parameter. typename followed by a
435 // qualified-id denotes the type in a non-type
436 // parameter-declaration.
437 Token Next = NextToken();
439 // If we have an identifier, skip over it.
440 if (Next.getKind() == tok::identifier)
441 Next = GetLookAheadToken(2);
443 switch (Next.getKind()) {
447 case tok::greatergreater:
456 /// ParseTemplateParameter - Parse a template-parameter (C++ [temp.param]).
458 /// template-parameter: [C++ temp.param]
460 /// parameter-declaration
462 /// type-parameter: (see below)
463 /// 'class' ...[opt] identifier[opt]
464 /// 'class' identifier[opt] '=' type-id
465 /// 'typename' ...[opt] identifier[opt]
466 /// 'typename' identifier[opt] '=' type-id
467 /// 'template' '<' template-parameter-list '>'
468 /// 'class' ...[opt] identifier[opt]
469 /// 'template' '<' template-parameter-list '>' 'class' identifier[opt]
471 NamedDecl *Parser::ParseTemplateParameter(unsigned Depth, unsigned Position) {
472 if (isStartOfTemplateTypeParameter())
473 return ParseTypeParameter(Depth, Position);
475 if (Tok.is(tok::kw_template))
476 return ParseTemplateTemplateParameter(Depth, Position);
478 // Is there just a typo in the input code? ('typedef' instead of 'typename')
479 if (Tok.is(tok::kw_typedef)) {
480 Diag(Tok.getLocation(), diag::err_expected_template_parameter);
482 Diag(Tok.getLocation(), diag::note_meant_to_use_typename)
483 << FixItHint::CreateReplacement(CharSourceRange::getCharRange(
484 Tok.getLocation(), Tok.getEndLoc()),
487 Tok.setKind(tok::kw_typename);
489 return ParseTypeParameter(Depth, Position);
492 // If it's none of the above, then it must be a parameter declaration.
493 // NOTE: This will pick up errors in the closure of the template parameter
494 // list (e.g., template < ; Check here to implement >> style closures.
495 return ParseNonTypeTemplateParameter(Depth, Position);
498 /// ParseTypeParameter - Parse a template type parameter (C++ [temp.param]).
499 /// Other kinds of template parameters are parsed in
500 /// ParseTemplateTemplateParameter and ParseNonTypeTemplateParameter.
502 /// type-parameter: [C++ temp.param]
503 /// 'class' ...[opt][C++0x] identifier[opt]
504 /// 'class' identifier[opt] '=' type-id
505 /// 'typename' ...[opt][C++0x] identifier[opt]
506 /// 'typename' identifier[opt] '=' type-id
507 NamedDecl *Parser::ParseTypeParameter(unsigned Depth, unsigned Position) {
508 assert(Tok.isOneOf(tok::kw_class, tok::kw_typename) &&
509 "A type-parameter starts with 'class' or 'typename'");
511 // Consume the 'class' or 'typename' keyword.
512 bool TypenameKeyword = Tok.is(tok::kw_typename);
513 SourceLocation KeyLoc = ConsumeToken();
515 // Grab the ellipsis (if given).
516 SourceLocation EllipsisLoc;
517 if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) {
519 getLangOpts().CPlusPlus11
520 ? diag::warn_cxx98_compat_variadic_templates
521 : diag::ext_variadic_templates);
524 // Grab the template parameter name (if given)
525 SourceLocation NameLoc;
526 IdentifierInfo *ParamName = nullptr;
527 if (Tok.is(tok::identifier)) {
528 ParamName = Tok.getIdentifierInfo();
529 NameLoc = ConsumeToken();
530 } else if (Tok.isOneOf(tok::equal, tok::comma, tok::greater,
531 tok::greatergreater)) {
532 // Unnamed template parameter. Don't have to do anything here, just
533 // don't consume this token.
535 Diag(Tok.getLocation(), diag::err_expected) << tok::identifier;
539 // Recover from misplaced ellipsis.
540 bool AlreadyHasEllipsis = EllipsisLoc.isValid();
541 if (TryConsumeToken(tok::ellipsis, EllipsisLoc))
542 DiagnoseMisplacedEllipsis(EllipsisLoc, NameLoc, AlreadyHasEllipsis, true);
544 // Grab a default argument (if available).
545 // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
546 // we introduce the type parameter into the local scope.
547 SourceLocation EqualLoc;
548 ParsedType DefaultArg;
549 if (TryConsumeToken(tok::equal, EqualLoc))
550 DefaultArg = ParseTypeName(/*Range=*/nullptr,
551 DeclaratorContext::TemplateTypeArgContext).get();
553 return Actions.ActOnTypeParameter(getCurScope(), TypenameKeyword, EllipsisLoc,
554 KeyLoc, ParamName, NameLoc, Depth, Position,
555 EqualLoc, DefaultArg);
558 /// ParseTemplateTemplateParameter - Handle the parsing of template
559 /// template parameters.
561 /// type-parameter: [C++ temp.param]
562 /// 'template' '<' template-parameter-list '>' type-parameter-key
563 /// ...[opt] identifier[opt]
564 /// 'template' '<' template-parameter-list '>' type-parameter-key
565 /// identifier[opt] = id-expression
566 /// type-parameter-key:
568 /// 'typename' [C++1z]
570 Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
571 assert(Tok.is(tok::kw_template) && "Expected 'template' keyword");
573 // Handle the template <...> part.
574 SourceLocation TemplateLoc = ConsumeToken();
575 SmallVector<NamedDecl*,8> TemplateParams;
576 SourceLocation LAngleLoc, RAngleLoc;
578 ParseScope TemplateParmScope(this, Scope::TemplateParamScope);
579 if (ParseTemplateParameters(Depth + 1, TemplateParams, LAngleLoc,
585 // Provide an ExtWarn if the C++1z feature of using 'typename' here is used.
586 // Generate a meaningful error if the user forgot to put class before the
587 // identifier, comma, or greater. Provide a fixit if the identifier, comma,
588 // or greater appear immediately or after 'struct'. In the latter case,
589 // replace the keyword with 'class'.
590 if (!TryConsumeToken(tok::kw_class)) {
591 bool Replace = Tok.isOneOf(tok::kw_typename, tok::kw_struct);
592 const Token &Next = Tok.is(tok::kw_struct) ? NextToken() : Tok;
593 if (Tok.is(tok::kw_typename)) {
594 Diag(Tok.getLocation(),
595 getLangOpts().CPlusPlus17
596 ? diag::warn_cxx14_compat_template_template_param_typename
597 : diag::ext_template_template_param_typename)
598 << (!getLangOpts().CPlusPlus17
599 ? FixItHint::CreateReplacement(Tok.getLocation(), "class")
601 } else if (Next.isOneOf(tok::identifier, tok::comma, tok::greater,
602 tok::greatergreater, tok::ellipsis)) {
603 Diag(Tok.getLocation(), diag::err_class_on_template_template_param)
604 << (Replace ? FixItHint::CreateReplacement(Tok.getLocation(), "class")
605 : FixItHint::CreateInsertion(Tok.getLocation(), "class "));
607 Diag(Tok.getLocation(), diag::err_class_on_template_template_param);
613 // Parse the ellipsis, if given.
614 SourceLocation EllipsisLoc;
615 if (TryConsumeToken(tok::ellipsis, EllipsisLoc))
617 getLangOpts().CPlusPlus11
618 ? diag::warn_cxx98_compat_variadic_templates
619 : diag::ext_variadic_templates);
621 // Get the identifier, if given.
622 SourceLocation NameLoc;
623 IdentifierInfo *ParamName = nullptr;
624 if (Tok.is(tok::identifier)) {
625 ParamName = Tok.getIdentifierInfo();
626 NameLoc = ConsumeToken();
627 } else if (Tok.isOneOf(tok::equal, tok::comma, tok::greater,
628 tok::greatergreater)) {
629 // Unnamed template parameter. Don't have to do anything here, just
630 // don't consume this token.
632 Diag(Tok.getLocation(), diag::err_expected) << tok::identifier;
636 // Recover from misplaced ellipsis.
637 bool AlreadyHasEllipsis = EllipsisLoc.isValid();
638 if (TryConsumeToken(tok::ellipsis, EllipsisLoc))
639 DiagnoseMisplacedEllipsis(EllipsisLoc, NameLoc, AlreadyHasEllipsis, true);
641 TemplateParameterList *ParamList =
642 Actions.ActOnTemplateParameterList(Depth, SourceLocation(),
643 TemplateLoc, LAngleLoc,
647 // Grab a default argument (if available).
648 // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
649 // we introduce the template parameter into the local scope.
650 SourceLocation EqualLoc;
651 ParsedTemplateArgument DefaultArg;
652 if (TryConsumeToken(tok::equal, EqualLoc)) {
653 DefaultArg = ParseTemplateTemplateArgument();
654 if (DefaultArg.isInvalid()) {
655 Diag(Tok.getLocation(),
656 diag::err_default_template_template_parameter_not_template);
657 SkipUntil(tok::comma, tok::greater, tok::greatergreater,
658 StopAtSemi | StopBeforeMatch);
662 return Actions.ActOnTemplateTemplateParameter(getCurScope(), TemplateLoc,
663 ParamList, EllipsisLoc,
664 ParamName, NameLoc, Depth,
665 Position, EqualLoc, DefaultArg);
668 /// ParseNonTypeTemplateParameter - Handle the parsing of non-type
669 /// template parameters (e.g., in "template<int Size> class array;").
671 /// template-parameter:
673 /// parameter-declaration
675 Parser::ParseNonTypeTemplateParameter(unsigned Depth, unsigned Position) {
676 // Parse the declaration-specifiers (i.e., the type).
677 // FIXME: The type should probably be restricted in some way... Not all
678 // declarators (parts of declarators?) are accepted for parameters.
679 DeclSpec DS(AttrFactory);
680 ParseDeclarationSpecifiers(DS, ParsedTemplateInfo(), AS_none,
681 DeclSpecContext::DSC_template_param);
683 // Parse this as a typename.
684 Declarator ParamDecl(DS, DeclaratorContext::TemplateParamContext);
685 ParseDeclarator(ParamDecl);
686 if (DS.getTypeSpecType() == DeclSpec::TST_unspecified) {
687 Diag(Tok.getLocation(), diag::err_expected_template_parameter);
691 // Recover from misplaced ellipsis.
692 SourceLocation EllipsisLoc;
693 if (TryConsumeToken(tok::ellipsis, EllipsisLoc))
694 DiagnoseMisplacedEllipsisInDeclarator(EllipsisLoc, ParamDecl);
696 // If there is a default value, parse it.
697 // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
698 // we introduce the template parameter into the local scope.
699 SourceLocation EqualLoc;
700 ExprResult DefaultArg;
701 if (TryConsumeToken(tok::equal, EqualLoc)) {
702 // C++ [temp.param]p15:
703 // When parsing a default template-argument for a non-type
704 // template-parameter, the first non-nested > is taken as the
705 // end of the template-parameter-list rather than a greater-than
707 GreaterThanIsOperatorScope G(GreaterThanIsOperator, false);
708 EnterExpressionEvaluationContext ConstantEvaluated(
709 Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated);
711 DefaultArg = Actions.CorrectDelayedTyposInExpr(ParseAssignmentExpression());
712 if (DefaultArg.isInvalid())
713 SkipUntil(tok::comma, tok::greater, StopAtSemi | StopBeforeMatch);
716 // Create the parameter.
717 return Actions.ActOnNonTypeTemplateParameter(getCurScope(), ParamDecl,
718 Depth, Position, EqualLoc,
722 void Parser::DiagnoseMisplacedEllipsis(SourceLocation EllipsisLoc,
723 SourceLocation CorrectLoc,
724 bool AlreadyHasEllipsis,
725 bool IdentifierHasName) {
727 if (!AlreadyHasEllipsis)
728 Insertion = FixItHint::CreateInsertion(CorrectLoc, "...");
729 Diag(EllipsisLoc, diag::err_misplaced_ellipsis_in_declaration)
730 << FixItHint::CreateRemoval(EllipsisLoc) << Insertion
731 << !IdentifierHasName;
734 void Parser::DiagnoseMisplacedEllipsisInDeclarator(SourceLocation EllipsisLoc,
736 assert(EllipsisLoc.isValid());
737 bool AlreadyHasEllipsis = D.getEllipsisLoc().isValid();
738 if (!AlreadyHasEllipsis)
739 D.setEllipsisLoc(EllipsisLoc);
740 DiagnoseMisplacedEllipsis(EllipsisLoc, D.getIdentifierLoc(),
741 AlreadyHasEllipsis, D.hasName());
744 /// Parses a '>' at the end of a template list.
746 /// If this function encounters '>>', '>>>', '>=', or '>>=', it tries
747 /// to determine if these tokens were supposed to be a '>' followed by
748 /// '>', '>>', '>=', or '>='. It emits an appropriate diagnostic if necessary.
750 /// \param RAngleLoc the location of the consumed '>'.
752 /// \param ConsumeLastToken if true, the '>' is consumed.
754 /// \param ObjCGenericList if true, this is the '>' closing an Objective-C
755 /// type parameter or type argument list, rather than a C++ template parameter
756 /// or argument list.
758 /// \returns true, if current token does not start with '>', false otherwise.
759 bool Parser::ParseGreaterThanInTemplateList(SourceLocation &RAngleLoc,
760 bool ConsumeLastToken,
761 bool ObjCGenericList) {
762 // What will be left once we've consumed the '>'.
763 tok::TokenKind RemainingToken;
764 const char *ReplacementStr = "> >";
765 bool MergeWithNextToken = false;
767 switch (Tok.getKind()) {
769 Diag(Tok.getLocation(), diag::err_expected) << tok::greater;
773 // Determine the location of the '>' token. Only consume this token
774 // if the caller asked us to.
775 RAngleLoc = Tok.getLocation();
776 if (ConsumeLastToken)
780 case tok::greatergreater:
781 RemainingToken = tok::greater;
784 case tok::greatergreatergreater:
785 RemainingToken = tok::greatergreater;
788 case tok::greaterequal:
789 RemainingToken = tok::equal;
790 ReplacementStr = "> =";
792 // Join two adjacent '=' tokens into one, for cases like:
793 // void (*p)() = f<int>;
795 if (NextToken().is(tok::equal) &&
796 areTokensAdjacent(Tok, NextToken())) {
797 RemainingToken = tok::equalequal;
798 MergeWithNextToken = true;
802 case tok::greatergreaterequal:
803 RemainingToken = tok::greaterequal;
807 // This template-id is terminated by a token that starts with a '>'.
808 // Outside C++11 and Objective-C, this is now error recovery.
810 // C++11 allows this when the token is '>>', and in CUDA + C++11 mode, we
811 // extend that treatment to also apply to the '>>>' token.
813 // Objective-C allows this in its type parameter / argument lists.
815 SourceLocation TokBeforeGreaterLoc = PrevTokLocation;
816 SourceLocation TokLoc = Tok.getLocation();
817 Token Next = NextToken();
819 // Whether splitting the current token after the '>' would undesirably result
820 // in the remaining token pasting with the token after it. This excludes the
821 // MergeWithNextToken cases, which we've already handled.
822 bool PreventMergeWithNextToken =
823 (RemainingToken == tok::greater ||
824 RemainingToken == tok::greatergreater) &&
825 (Next.isOneOf(tok::greater, tok::greatergreater,
826 tok::greatergreatergreater, tok::equal, tok::greaterequal,
827 tok::greatergreaterequal, tok::equalequal)) &&
828 areTokensAdjacent(Tok, Next);
830 // Diagnose this situation as appropriate.
831 if (!ObjCGenericList) {
832 // The source range of the replaced token(s).
833 CharSourceRange ReplacementRange = CharSourceRange::getCharRange(
834 TokLoc, Lexer::AdvanceToTokenCharacter(TokLoc, 2, PP.getSourceManager(),
837 // A hint to put a space between the '>>'s. In order to make the hint as
838 // clear as possible, we include the characters either side of the space in
839 // the replacement, rather than just inserting a space at SecondCharLoc.
840 FixItHint Hint1 = FixItHint::CreateReplacement(ReplacementRange,
843 // A hint to put another space after the token, if it would otherwise be
844 // lexed differently.
846 if (PreventMergeWithNextToken)
847 Hint2 = FixItHint::CreateInsertion(Next.getLocation(), " ");
849 unsigned DiagId = diag::err_two_right_angle_brackets_need_space;
850 if (getLangOpts().CPlusPlus11 &&
851 (Tok.is(tok::greatergreater) || Tok.is(tok::greatergreatergreater)))
852 DiagId = diag::warn_cxx98_compat_two_right_angle_brackets;
853 else if (Tok.is(tok::greaterequal))
854 DiagId = diag::err_right_angle_bracket_equal_needs_space;
855 Diag(TokLoc, DiagId) << Hint1 << Hint2;
858 // Find the "length" of the resulting '>' token. This is not always 1, as it
859 // can contain escaped newlines.
860 unsigned GreaterLength = Lexer::getTokenPrefixLength(
861 TokLoc, 1, PP.getSourceManager(), getLangOpts());
863 // Annotate the source buffer to indicate that we split the token after the
864 // '>'. This allows us to properly find the end of, and extract the spelling
865 // of, the '>' token later.
866 RAngleLoc = PP.SplitToken(TokLoc, GreaterLength);
868 // Strip the initial '>' from the token.
869 bool CachingTokens = PP.IsPreviousCachedToken(Tok);
872 Greater.setLocation(RAngleLoc);
873 Greater.setKind(tok::greater);
874 Greater.setLength(GreaterLength);
876 unsigned OldLength = Tok.getLength();
877 if (MergeWithNextToken) {
879 OldLength += Tok.getLength();
882 Tok.setKind(RemainingToken);
883 Tok.setLength(OldLength - GreaterLength);
885 // Split the second token if lexing it normally would lex a different token
886 // (eg, the fifth token in 'A<B>>>' should re-lex as '>', not '>>').
887 SourceLocation AfterGreaterLoc = TokLoc.getLocWithOffset(GreaterLength);
888 if (PreventMergeWithNextToken)
889 AfterGreaterLoc = PP.SplitToken(AfterGreaterLoc, Tok.getLength());
890 Tok.setLocation(AfterGreaterLoc);
892 // Update the token cache to match what we just did if necessary.
894 // If the previous cached token is being merged, delete it.
895 if (MergeWithNextToken)
896 PP.ReplacePreviousCachedToken({});
898 if (ConsumeLastToken)
899 PP.ReplacePreviousCachedToken({Greater, Tok});
901 PP.ReplacePreviousCachedToken({Greater});
904 if (ConsumeLastToken) {
905 PrevTokLocation = RAngleLoc;
907 PrevTokLocation = TokBeforeGreaterLoc;
916 /// Parses a template-id that after the template name has
917 /// already been parsed.
919 /// This routine takes care of parsing the enclosed template argument
920 /// list ('<' template-parameter-list [opt] '>') and placing the
921 /// results into a form that can be transferred to semantic analysis.
923 /// \param ConsumeLastToken if true, then we will consume the last
924 /// token that forms the template-id. Otherwise, we will leave the
925 /// last token in the stream (e.g., so that it can be replaced with an
926 /// annotation token).
928 Parser::ParseTemplateIdAfterTemplateName(bool ConsumeLastToken,
929 SourceLocation &LAngleLoc,
930 TemplateArgList &TemplateArgs,
931 SourceLocation &RAngleLoc) {
932 assert(Tok.is(tok::less) && "Must have already parsed the template-name");
935 LAngleLoc = ConsumeToken();
937 // Parse the optional template-argument-list.
938 bool Invalid = false;
940 GreaterThanIsOperatorScope G(GreaterThanIsOperator, false);
941 if (Tok.isNot(tok::greater) && Tok.isNot(tok::greatergreater))
942 Invalid = ParseTemplateArgumentList(TemplateArgs);
945 // Try to find the closing '>'.
946 if (ConsumeLastToken)
947 SkipUntil(tok::greater, StopAtSemi);
949 SkipUntil(tok::greater, StopAtSemi | StopBeforeMatch);
954 return ParseGreaterThanInTemplateList(RAngleLoc, ConsumeLastToken,
955 /*ObjCGenericList=*/false);
958 /// Replace the tokens that form a simple-template-id with an
959 /// annotation token containing the complete template-id.
961 /// The first token in the stream must be the name of a template that
962 /// is followed by a '<'. This routine will parse the complete
963 /// simple-template-id and replace the tokens with a single annotation
964 /// token with one of two different kinds: if the template-id names a
965 /// type (and \p AllowTypeAnnotation is true), the annotation token is
966 /// a type annotation that includes the optional nested-name-specifier
967 /// (\p SS). Otherwise, the annotation token is a template-id
968 /// annotation that does not include the optional
969 /// nested-name-specifier.
971 /// \param Template the declaration of the template named by the first
972 /// token (an identifier), as returned from \c Action::isTemplateName().
974 /// \param TNK the kind of template that \p Template
975 /// refers to, as returned from \c Action::isTemplateName().
977 /// \param SS if non-NULL, the nested-name-specifier that precedes
978 /// this template name.
980 /// \param TemplateKWLoc if valid, specifies that this template-id
981 /// annotation was preceded by the 'template' keyword and gives the
982 /// location of that keyword. If invalid (the default), then this
983 /// template-id was not preceded by a 'template' keyword.
985 /// \param AllowTypeAnnotation if true (the default), then a
986 /// simple-template-id that refers to a class template, template
987 /// template parameter, or other template that produces a type will be
988 /// replaced with a type annotation token. Otherwise, the
989 /// simple-template-id is always replaced with a template-id
990 /// annotation token.
992 /// If an unrecoverable parse error occurs and no annotation token can be
993 /// formed, this function returns true.
995 bool Parser::AnnotateTemplateIdToken(TemplateTy Template, TemplateNameKind TNK,
997 SourceLocation TemplateKWLoc,
998 UnqualifiedId &TemplateName,
999 bool AllowTypeAnnotation) {
1000 assert(getLangOpts().CPlusPlus && "Can only annotate template-ids in C++");
1001 assert(Template && Tok.is(tok::less) &&
1002 "Parser isn't at the beginning of a template-id");
1004 // Consume the template-name.
1005 SourceLocation TemplateNameLoc = TemplateName.getSourceRange().getBegin();
1007 // Parse the enclosed template argument list.
1008 SourceLocation LAngleLoc, RAngleLoc;
1009 TemplateArgList TemplateArgs;
1010 bool Invalid = ParseTemplateIdAfterTemplateName(false, LAngleLoc,
1015 // If we failed to parse the template ID but skipped ahead to a >, we're not
1016 // going to be able to form a token annotation. Eat the '>' if present.
1017 TryConsumeToken(tok::greater);
1021 ASTTemplateArgsPtr TemplateArgsPtr(TemplateArgs);
1023 // Build the annotation token.
1024 if (TNK == TNK_Type_template && AllowTypeAnnotation) {
1025 TypeResult Type = Actions.ActOnTemplateIdType(
1026 SS, TemplateKWLoc, Template, TemplateName.Identifier,
1027 TemplateNameLoc, LAngleLoc, TemplateArgsPtr, RAngleLoc);
1028 if (Type.isInvalid()) {
1029 // If we failed to parse the template ID but skipped ahead to a >, we're
1030 // not going to be able to form a token annotation. Eat the '>' if
1032 TryConsumeToken(tok::greater);
1036 Tok.setKind(tok::annot_typename);
1037 setTypeAnnotation(Tok, Type.get());
1038 if (SS.isNotEmpty())
1039 Tok.setLocation(SS.getBeginLoc());
1040 else if (TemplateKWLoc.isValid())
1041 Tok.setLocation(TemplateKWLoc);
1043 Tok.setLocation(TemplateNameLoc);
1045 // Build a template-id annotation token that can be processed
1047 Tok.setKind(tok::annot_template_id);
1049 IdentifierInfo *TemplateII =
1050 TemplateName.getKind() == UnqualifiedIdKind::IK_Identifier
1051 ? TemplateName.Identifier
1054 OverloadedOperatorKind OpKind =
1055 TemplateName.getKind() == UnqualifiedIdKind::IK_Identifier
1057 : TemplateName.OperatorFunctionId.Operator;
1059 TemplateIdAnnotation *TemplateId = TemplateIdAnnotation::Create(
1060 SS, TemplateKWLoc, TemplateNameLoc, TemplateII, OpKind, Template, TNK,
1061 LAngleLoc, RAngleLoc, TemplateArgs, TemplateIds);
1063 Tok.setAnnotationValue(TemplateId);
1064 if (TemplateKWLoc.isValid())
1065 Tok.setLocation(TemplateKWLoc);
1067 Tok.setLocation(TemplateNameLoc);
1070 // Common fields for the annotation token
1071 Tok.setAnnotationEndLoc(RAngleLoc);
1073 // In case the tokens were cached, have Preprocessor replace them with the
1074 // annotation token.
1075 PP.AnnotateCachedTokens(Tok);
1079 /// Replaces a template-id annotation token with a type
1080 /// annotation token.
1082 /// If there was a failure when forming the type from the template-id,
1083 /// a type annotation token will still be created, but will have a
1084 /// NULL type pointer to signify an error.
1086 /// \param IsClassName Is this template-id appearing in a context where we
1087 /// know it names a class, such as in an elaborated-type-specifier or
1088 /// base-specifier? ('typename' and 'template' are unneeded and disallowed
1089 /// in those contexts.)
1090 void Parser::AnnotateTemplateIdTokenAsType(bool IsClassName) {
1091 assert(Tok.is(tok::annot_template_id) && "Requires template-id tokens");
1093 TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
1094 assert((TemplateId->Kind == TNK_Type_template ||
1095 TemplateId->Kind == TNK_Dependent_template_name) &&
1096 "Only works for type and dependent templates");
1098 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
1099 TemplateId->NumArgs);
1102 = Actions.ActOnTemplateIdType(TemplateId->SS,
1103 TemplateId->TemplateKWLoc,
1104 TemplateId->Template,
1106 TemplateId->TemplateNameLoc,
1107 TemplateId->LAngleLoc,
1109 TemplateId->RAngleLoc,
1110 /*IsCtorOrDtorName*/false,
1112 // Create the new "type" annotation token.
1113 Tok.setKind(tok::annot_typename);
1114 setTypeAnnotation(Tok, Type.isInvalid() ? nullptr : Type.get());
1115 if (TemplateId->SS.isNotEmpty()) // it was a C++ qualified type name.
1116 Tok.setLocation(TemplateId->SS.getBeginLoc());
1117 // End location stays the same
1119 // Replace the template-id annotation token, and possible the scope-specifier
1120 // that precedes it, with the typename annotation token.
1121 PP.AnnotateCachedTokens(Tok);
1124 /// Determine whether the given token can end a template argument.
1125 static bool isEndOfTemplateArgument(Token Tok) {
1126 return Tok.isOneOf(tok::comma, tok::greater, tok::greatergreater);
1129 /// Parse a C++ template template argument.
1130 ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() {
1131 if (!Tok.is(tok::identifier) && !Tok.is(tok::coloncolon) &&
1132 !Tok.is(tok::annot_cxxscope))
1133 return ParsedTemplateArgument();
1135 // C++0x [temp.arg.template]p1:
1136 // A template-argument for a template template-parameter shall be the name
1137 // of a class template or an alias template, expressed as id-expression.
1139 // We parse an id-expression that refers to a class template or alias
1140 // template. The grammar we parse is:
1142 // nested-name-specifier[opt] template[opt] identifier ...[opt]
1144 // followed by a token that terminates a template argument, such as ',',
1145 // '>', or (in some cases) '>>'.
1146 CXXScopeSpec SS; // nested-name-specifier, if present
1147 ParseOptionalCXXScopeSpecifier(SS, nullptr,
1148 /*EnteringContext=*/false);
1150 ParsedTemplateArgument Result;
1151 SourceLocation EllipsisLoc;
1152 if (SS.isSet() && Tok.is(tok::kw_template)) {
1153 // Parse the optional 'template' keyword following the
1154 // nested-name-specifier.
1155 SourceLocation TemplateKWLoc = ConsumeToken();
1157 if (Tok.is(tok::identifier)) {
1158 // We appear to have a dependent template name.
1160 Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
1161 ConsumeToken(); // the identifier
1163 TryConsumeToken(tok::ellipsis, EllipsisLoc);
1165 // If the next token signals the end of a template argument,
1166 // then we have a dependent template name that could be a template
1167 // template argument.
1168 TemplateTy Template;
1169 if (isEndOfTemplateArgument(Tok) &&
1170 Actions.ActOnDependentTemplateName(
1171 getCurScope(), SS, TemplateKWLoc, Name,
1172 /*ObjectType=*/nullptr,
1173 /*EnteringContext=*/false, Template))
1174 Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
1176 } else if (Tok.is(tok::identifier)) {
1177 // We may have a (non-dependent) template name.
1178 TemplateTy Template;
1180 Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
1181 ConsumeToken(); // the identifier
1183 TryConsumeToken(tok::ellipsis, EllipsisLoc);
1185 if (isEndOfTemplateArgument(Tok)) {
1186 bool MemberOfUnknownSpecialization;
1187 TemplateNameKind TNK = Actions.isTemplateName(
1189 /*hasTemplateKeyword=*/false, Name,
1190 /*ObjectType=*/nullptr,
1191 /*EnteringContext=*/false, Template, MemberOfUnknownSpecialization);
1192 if (TNK == TNK_Dependent_template_name || TNK == TNK_Type_template) {
1193 // We have an id-expression that refers to a class template or
1194 // (C++0x) alias template.
1195 Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
1200 // If this is a pack expansion, build it as such.
1201 if (EllipsisLoc.isValid() && !Result.isInvalid())
1202 Result = Actions.ActOnPackExpansion(Result, EllipsisLoc);
1207 /// ParseTemplateArgument - Parse a C++ template argument (C++ [temp.names]).
1209 /// template-argument: [C++ 14.2]
1210 /// constant-expression
1213 ParsedTemplateArgument Parser::ParseTemplateArgument() {
1214 // C++ [temp.arg]p2:
1215 // In a template-argument, an ambiguity between a type-id and an
1216 // expression is resolved to a type-id, regardless of the form of
1217 // the corresponding template-parameter.
1219 // Therefore, we initially try to parse a type-id - and isCXXTypeId might look
1220 // up and annotate an identifier as an id-expression during disambiguation,
1221 // so enter the appropriate context for a constant expression template
1222 // argument before trying to disambiguate.
1224 EnterExpressionEvaluationContext EnterConstantEvaluated(
1225 Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated,
1226 /*LambdaContextDecl=*/nullptr,
1227 /*ExprContext=*/Sema::ExpressionEvaluationContextRecord::EK_TemplateArgument);
1228 if (isCXXTypeId(TypeIdAsTemplateArgument)) {
1229 TypeResult TypeArg = ParseTypeName(
1230 /*Range=*/nullptr, DeclaratorContext::TemplateArgContext);
1231 return Actions.ActOnTemplateTypeArgument(TypeArg);
1234 // Try to parse a template template argument.
1236 TentativeParsingAction TPA(*this);
1238 ParsedTemplateArgument TemplateTemplateArgument
1239 = ParseTemplateTemplateArgument();
1240 if (!TemplateTemplateArgument.isInvalid()) {
1242 return TemplateTemplateArgument;
1245 // Revert this tentative parse to parse a non-type template argument.
1249 // Parse a non-type template argument.
1250 SourceLocation Loc = Tok.getLocation();
1251 ExprResult ExprArg = ParseConstantExpressionInExprEvalContext(MaybeTypeCast);
1252 if (ExprArg.isInvalid() || !ExprArg.get())
1253 return ParsedTemplateArgument();
1255 return ParsedTemplateArgument(ParsedTemplateArgument::NonType,
1256 ExprArg.get(), Loc);
1259 /// Determine whether the current tokens can only be parsed as a
1260 /// template argument list (starting with the '<') and never as a '<'
1262 bool Parser::IsTemplateArgumentList(unsigned Skip) {
1263 struct AlwaysRevertAction : TentativeParsingAction {
1264 AlwaysRevertAction(Parser &P) : TentativeParsingAction(P) { }
1265 ~AlwaysRevertAction() { Revert(); }
1274 if (!TryConsumeToken(tok::less))
1277 // An empty template argument list.
1278 if (Tok.is(tok::greater))
1281 // See whether we have declaration specifiers, which indicate a type.
1282 while (isCXXDeclarationSpecifier() == TPResult::True)
1285 // If we have a '>' or a ',' then this is a template argument list.
1286 return Tok.isOneOf(tok::greater, tok::comma);
1289 /// ParseTemplateArgumentList - Parse a C++ template-argument-list
1290 /// (C++ [temp.names]). Returns true if there was an error.
1292 /// template-argument-list: [C++ 14.2]
1293 /// template-argument
1294 /// template-argument-list ',' template-argument
1296 Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs) {
1298 ColonProtectionRAIIObject ColonProtection(*this, false);
1301 ParsedTemplateArgument Arg = ParseTemplateArgument();
1302 SourceLocation EllipsisLoc;
1303 if (TryConsumeToken(tok::ellipsis, EllipsisLoc))
1304 Arg = Actions.ActOnPackExpansion(Arg, EllipsisLoc);
1306 if (Arg.isInvalid()) {
1307 SkipUntil(tok::comma, tok::greater, StopAtSemi | StopBeforeMatch);
1311 // Save this template argument.
1312 TemplateArgs.push_back(Arg);
1314 // If the next token is a comma, consume it and keep reading
1316 } while (TryConsumeToken(tok::comma));
1321 /// Parse a C++ explicit template instantiation
1322 /// (C++ [temp.explicit]).
1324 /// explicit-instantiation:
1325 /// 'extern' [opt] 'template' declaration
1327 /// Note that the 'extern' is a GNU extension and C++11 feature.
1328 Decl *Parser::ParseExplicitInstantiation(DeclaratorContext Context,
1329 SourceLocation ExternLoc,
1330 SourceLocation TemplateLoc,
1331 SourceLocation &DeclEnd,
1332 ParsedAttributes &AccessAttrs,
1333 AccessSpecifier AS) {
1334 // This isn't really required here.
1335 ParsingDeclRAIIObject
1336 ParsingTemplateParams(*this, ParsingDeclRAIIObject::NoParent);
1338 return ParseSingleDeclarationAfterTemplate(
1339 Context, ParsedTemplateInfo(ExternLoc, TemplateLoc),
1340 ParsingTemplateParams, DeclEnd, AccessAttrs, AS);
1343 SourceRange Parser::ParsedTemplateInfo::getSourceRange() const {
1345 return getTemplateParamsRange(TemplateParams->data(),
1346 TemplateParams->size());
1348 SourceRange R(TemplateLoc);
1349 if (ExternLoc.isValid())
1350 R.setBegin(ExternLoc);
1354 void Parser::LateTemplateParserCallback(void *P, LateParsedTemplate &LPT) {
1355 ((Parser *)P)->ParseLateTemplatedFuncDef(LPT);
1358 /// Late parse a C++ function template in Microsoft mode.
1359 void Parser::ParseLateTemplatedFuncDef(LateParsedTemplate &LPT) {
1363 // Get the FunctionDecl.
1364 FunctionDecl *FunD = LPT.D->getAsFunction();
1365 // Track template parameter depth.
1366 TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
1368 // To restore the context after late parsing.
1369 Sema::ContextRAII GlobalSavedContext(
1370 Actions, Actions.Context.getTranslationUnitDecl());
1372 SmallVector<ParseScope*, 4> TemplateParamScopeStack;
1374 // Get the list of DeclContexts to reenter.
1375 SmallVector<DeclContext*, 4> DeclContextsToReenter;
1376 DeclContext *DD = FunD;
1377 while (DD && !DD->isTranslationUnit()) {
1378 DeclContextsToReenter.push_back(DD);
1379 DD = DD->getLexicalParent();
1382 // Reenter template scopes from outermost to innermost.
1383 SmallVectorImpl<DeclContext *>::reverse_iterator II =
1384 DeclContextsToReenter.rbegin();
1385 for (; II != DeclContextsToReenter.rend(); ++II) {
1386 TemplateParamScopeStack.push_back(new ParseScope(this,
1387 Scope::TemplateParamScope));
1388 unsigned NumParamLists =
1389 Actions.ActOnReenterTemplateScope(getCurScope(), cast<Decl>(*II));
1390 CurTemplateDepthTracker.addDepth(NumParamLists);
1392 TemplateParamScopeStack.push_back(new ParseScope(this, Scope::DeclScope));
1393 Actions.PushDeclContext(Actions.getCurScope(), *II);
1397 assert(!LPT.Toks.empty() && "Empty body!");
1399 // Append the current token at the end of the new token stream so that it
1400 // doesn't get lost.
1401 LPT.Toks.push_back(Tok);
1402 PP.EnterTokenStream(LPT.Toks, true);
1404 // Consume the previously pushed token.
1405 ConsumeAnyToken(/*ConsumeCodeCompletionTok=*/true);
1406 assert(Tok.isOneOf(tok::l_brace, tok::colon, tok::kw_try) &&
1407 "Inline method not starting with '{', ':' or 'try'");
1409 // Parse the method body. Function body parsing code is similar enough
1410 // to be re-used for method bodies as well.
1411 ParseScope FnScope(this, Scope::FnScope | Scope::DeclScope |
1412 Scope::CompoundStmtScope);
1414 // Recreate the containing function DeclContext.
1415 Sema::ContextRAII FunctionSavedContext(Actions,
1416 Actions.getContainingDC(FunD));
1418 Actions.ActOnStartOfFunctionDef(getCurScope(), FunD);
1420 if (Tok.is(tok::kw_try)) {
1421 ParseFunctionTryBlock(LPT.D, FnScope);
1423 if (Tok.is(tok::colon))
1424 ParseConstructorInitializer(LPT.D);
1426 Actions.ActOnDefaultCtorInitializers(LPT.D);
1428 if (Tok.is(tok::l_brace)) {
1429 assert((!isa<FunctionTemplateDecl>(LPT.D) ||
1430 cast<FunctionTemplateDecl>(LPT.D)
1431 ->getTemplateParameters()
1432 ->getDepth() == TemplateParameterDepth - 1) &&
1433 "TemplateParameterDepth should be greater than the depth of "
1434 "current template being instantiated!");
1435 ParseFunctionStatementBody(LPT.D, FnScope);
1436 Actions.UnmarkAsLateParsedTemplate(FunD);
1438 Actions.ActOnFinishFunctionBody(LPT.D, nullptr);
1443 SmallVectorImpl<ParseScope *>::reverse_iterator I =
1444 TemplateParamScopeStack.rbegin();
1445 for (; I != TemplateParamScopeStack.rend(); ++I)
1449 /// Lex a delayed template function for late parsing.
1450 void Parser::LexTemplateFunctionForLateParsing(CachedTokens &Toks) {
1451 tok::TokenKind kind = Tok.getKind();
1452 if (!ConsumeAndStoreFunctionPrologue(Toks)) {
1453 // Consume everything up to (and including) the matching right brace.
1454 ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
1457 // If we're in a function-try-block, we need to store all the catch blocks.
1458 if (kind == tok::kw_try) {
1459 while (Tok.is(tok::kw_catch)) {
1460 ConsumeAndStoreUntil(tok::l_brace, Toks, /*StopAtSemi=*/false);
1461 ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
1466 /// We've parsed something that could plausibly be intended to be a template
1467 /// name (\p LHS) followed by a '<' token, and the following code can't possibly
1468 /// be an expression. Determine if this is likely to be a template-id and if so,
1470 bool Parser::diagnoseUnknownTemplateId(ExprResult LHS, SourceLocation Less) {
1471 TentativeParsingAction TPA(*this);
1472 // FIXME: We could look at the token sequence in a lot more detail here.
1473 if (SkipUntil(tok::greater, tok::greatergreater, tok::greatergreatergreater,
1474 StopAtSemi | StopBeforeMatch)) {
1477 SourceLocation Greater;
1478 ParseGreaterThanInTemplateList(Greater, true, false);
1479 Actions.diagnoseExprIntendedAsTemplateName(getCurScope(), LHS,
1484 // There's no matching '>' token, this probably isn't supposed to be
1485 // interpreted as a template-id. Parse it as an (ill-formed) comparison.
1490 void Parser::checkPotentialAngleBracket(ExprResult &PotentialTemplateName) {
1491 assert(Tok.is(tok::less) && "not at a potential angle bracket");
1493 bool DependentTemplateName = false;
1494 if (!Actions.mightBeIntendedToBeTemplateName(PotentialTemplateName,
1495 DependentTemplateName))
1498 // OK, this might be a name that the user intended to be parsed as a
1499 // template-name, followed by a '<' token. Check for some easy cases.
1501 // If we have potential_template<>, then it's supposed to be a template-name.
1502 if (NextToken().is(tok::greater) ||
1503 (getLangOpts().CPlusPlus11 &&
1504 NextToken().isOneOf(tok::greatergreater, tok::greatergreatergreater))) {
1505 SourceLocation Less = ConsumeToken();
1506 SourceLocation Greater;
1507 ParseGreaterThanInTemplateList(Greater, true, false);
1508 Actions.diagnoseExprIntendedAsTemplateName(
1509 getCurScope(), PotentialTemplateName, Less, Greater);
1510 // FIXME: Perform error recovery.
1511 PotentialTemplateName = ExprError();
1515 // If we have 'potential_template<type-id', assume it's supposed to be a
1516 // template-name if there's a matching '>' later on.
1518 // FIXME: Avoid the tentative parse when NextToken() can't begin a type.
1519 TentativeParsingAction TPA(*this);
1520 SourceLocation Less = ConsumeToken();
1521 if (isTypeIdUnambiguously() &&
1522 diagnoseUnknownTemplateId(PotentialTemplateName, Less)) {
1524 // FIXME: Perform error recovery.
1525 PotentialTemplateName = ExprError();
1531 // Otherwise, remember that we saw this in case we see a potentially-matching
1532 // '>' token later on.
1533 AngleBracketTracker::Priority Priority =
1534 (DependentTemplateName ? AngleBracketTracker::DependentName
1535 : AngleBracketTracker::PotentialTypo) |
1536 (Tok.hasLeadingSpace() ? AngleBracketTracker::SpaceBeforeLess
1537 : AngleBracketTracker::NoSpaceBeforeLess);
1538 AngleBrackets.add(*this, PotentialTemplateName.get(), Tok.getLocation(),
1542 bool Parser::checkPotentialAngleBracketDelimiter(
1543 const AngleBracketTracker::Loc &LAngle, const Token &OpToken) {
1544 // If a comma in an expression context is followed by a type that can be a
1545 // template argument and cannot be an expression, then this is ill-formed,
1546 // but might be intended to be part of a template-id.
1547 if (OpToken.is(tok::comma) && isTypeIdUnambiguously() &&
1548 diagnoseUnknownTemplateId(LAngle.TemplateName, LAngle.LessLoc)) {
1549 AngleBrackets.clear(*this);
1553 // If a context that looks like a template-id is followed by '()', then
1554 // this is ill-formed, but might be intended to be a template-id
1555 // followed by '()'.
1556 if (OpToken.is(tok::greater) && Tok.is(tok::l_paren) &&
1557 NextToken().is(tok::r_paren)) {
1558 Actions.diagnoseExprIntendedAsTemplateName(
1559 getCurScope(), LAngle.TemplateName, LAngle.LessLoc,
1560 OpToken.getLocation());
1561 AngleBrackets.clear(*this);
1565 // After a '>' (etc), we're no longer potentially in a construct that's
1566 // intended to be treated as a template-id.
1567 if (OpToken.is(tok::greater) ||
1568 (getLangOpts().CPlusPlus11 &&
1569 OpToken.isOneOf(tok::greatergreater, tok::greatergreatergreater)))
1570 AngleBrackets.clear(*this);