1//===--- ParseTemplate.cpp - Template Parsing -----------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements parsing of C++ templates.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/AST/ASTContext.h"
14#include "clang/AST/DeclTemplate.h"
15#include "clang/AST/ExprCXX.h"
16#include "clang/Basic/DiagnosticParse.h"
17#include "clang/Parse/Parser.h"
18#include "clang/Parse/RAIIObjectsForParser.h"
19#include "clang/Sema/DeclSpec.h"
20#include "clang/Sema/EnterExpressionEvaluationContext.h"
21#include "clang/Sema/ParsedTemplate.h"
22#include "clang/Sema/Scope.h"
23using namespace clang;
24
25unsigned Parser::ReenterTemplateScopes(MultiParseScope &S, Decl *D) {
26 return Actions.ActOnReenterTemplateScope(Template: D, EnterScope: [&] {
27 S.Enter(ScopeFlags: Scope::TemplateParamScope);
28 return Actions.getCurScope();
29 });
30}
31
32Parser::DeclGroupPtrTy
33Parser::ParseDeclarationStartingWithTemplate(DeclaratorContext Context,
34 SourceLocation &DeclEnd,
35 ParsedAttributes &AccessAttrs) {
36 ObjCDeclContextSwitch ObjCDC(*this);
37
38 if (Tok.is(K: tok::kw_template) && NextToken().isNot(K: tok::less)) {
39 return ParseExplicitInstantiation(Context, ExternLoc: SourceLocation(), TemplateLoc: ConsumeToken(),
40 DeclEnd, AccessAttrs,
41 AS: AccessSpecifier::AS_none);
42 }
43 return ParseTemplateDeclarationOrSpecialization(Context, DeclEnd, AccessAttrs,
44 AS: AccessSpecifier::AS_none);
45}
46
47Parser::DeclGroupPtrTy Parser::ParseTemplateDeclarationOrSpecialization(
48 DeclaratorContext Context, SourceLocation &DeclEnd,
49 ParsedAttributes &AccessAttrs, AccessSpecifier AS) {
50 assert(Tok.isOneOf(tok::kw_export, tok::kw_template) &&
51 "Token does not start a template declaration.");
52
53 MultiParseScope TemplateParamScopes(*this);
54
55 // Tell the action that names should be checked in the context of
56 // the declaration to come.
57 ParsingDeclRAIIObject
58 ParsingTemplateParams(*this, ParsingDeclRAIIObject::NoParent);
59
60 // Parse multiple levels of template headers within this template
61 // parameter scope, e.g.,
62 //
63 // template<typename T>
64 // template<typename U>
65 // class A<T>::B { ... };
66 //
67 // We parse multiple levels non-recursively so that we can build a
68 // single data structure containing all of the template parameter
69 // lists to easily differentiate between the case above and:
70 //
71 // template<typename T>
72 // class A {
73 // template<typename U> class B;
74 // };
75 //
76 // In the first case, the action for declaring A<T>::B receives
77 // both template parameter lists. In the second case, the action for
78 // defining A<T>::B receives just the inner template parameter list
79 // (and retrieves the outer template parameter list from its
80 // context).
81 bool isSpecialization = true;
82 bool LastParamListWasEmpty = false;
83 TemplateParameterLists ParamLists;
84 TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
85
86 do {
87 // Consume the 'export', if any.
88 SourceLocation ExportLoc;
89 TryConsumeToken(Expected: tok::kw_export, Loc&: ExportLoc);
90
91 // Consume the 'template', which should be here.
92 SourceLocation TemplateLoc;
93 if (!TryConsumeToken(Expected: tok::kw_template, Loc&: TemplateLoc)) {
94 Diag(Tok.getLocation(), diag::err_expected_template);
95 return nullptr;
96 }
97
98 // Parse the '<' template-parameter-list '>'
99 SourceLocation LAngleLoc, RAngleLoc;
100 SmallVector<NamedDecl*, 4> TemplateParams;
101 if (ParseTemplateParameters(TemplateScopes&: TemplateParamScopes,
102 Depth: CurTemplateDepthTracker.getDepth(),
103 TemplateParams, LAngleLoc, RAngleLoc)) {
104 // Skip until the semi-colon or a '}'.
105 SkipUntil(T: tok::r_brace, Flags: StopAtSemi | StopBeforeMatch);
106 TryConsumeToken(Expected: tok::semi);
107 return nullptr;
108 }
109
110 ExprResult OptionalRequiresClauseConstraintER;
111 if (!TemplateParams.empty()) {
112 isSpecialization = false;
113 ++CurTemplateDepthTracker;
114
115 if (TryConsumeToken(Expected: tok::kw_requires)) {
116 OptionalRequiresClauseConstraintER =
117 Actions.ActOnRequiresClause(ConstraintExpr: ParseConstraintLogicalOrExpression(
118 /*IsTrailingRequiresClause=*/false));
119 if (!OptionalRequiresClauseConstraintER.isUsable()) {
120 // Skip until the semi-colon or a '}'.
121 SkipUntil(T: tok::r_brace, Flags: StopAtSemi | StopBeforeMatch);
122 TryConsumeToken(Expected: tok::semi);
123 return nullptr;
124 }
125 }
126 } else {
127 LastParamListWasEmpty = true;
128 }
129
130 ParamLists.push_back(Elt: Actions.ActOnTemplateParameterList(
131 Depth: CurTemplateDepthTracker.getDepth(), ExportLoc, TemplateLoc, LAngleLoc,
132 Params: TemplateParams, RAngleLoc, RequiresClause: OptionalRequiresClauseConstraintER.get()));
133 } while (Tok.isOneOf(K1: tok::kw_export, K2: tok::kw_template));
134
135 ParsedTemplateInfo TemplateInfo(&ParamLists, isSpecialization,
136 LastParamListWasEmpty);
137
138 // Parse the actual template declaration.
139 if (Tok.is(K: tok::kw_concept)) {
140 Decl *ConceptDecl = ParseConceptDefinition(TemplateInfo, DeclEnd);
141 // We need to explicitly pass ConceptDecl to ParsingDeclRAIIObject, so that
142 // delayed diagnostics (e.g. warn_deprecated) have a Decl to work with.
143 ParsingTemplateParams.complete(D: ConceptDecl);
144 return Actions.ConvertDeclToDeclGroup(Ptr: ConceptDecl);
145 }
146
147 return ParseDeclarationAfterTemplate(
148 Context, TemplateInfo, DiagsFromParams&: ParsingTemplateParams, DeclEnd, AccessAttrs, AS);
149}
150
151Parser::DeclGroupPtrTy Parser::ParseTemplateDeclarationOrSpecialization(
152 DeclaratorContext Context, SourceLocation &DeclEnd, AccessSpecifier AS) {
153 ParsedAttributes AccessAttrs(AttrFactory);
154 return ParseTemplateDeclarationOrSpecialization(Context, DeclEnd, AccessAttrs,
155 AS);
156}
157
158Parser::DeclGroupPtrTy Parser::ParseDeclarationAfterTemplate(
159 DeclaratorContext Context, ParsedTemplateInfo &TemplateInfo,
160 ParsingDeclRAIIObject &DiagsFromTParams, SourceLocation &DeclEnd,
161 ParsedAttributes &AccessAttrs, AccessSpecifier AS) {
162 assert(TemplateInfo.Kind != ParsedTemplateKind::NonTemplate &&
163 "Template information required");
164
165 if (Tok.is(K: tok::kw_static_assert)) {
166 // A static_assert declaration may not be templated.
167 Diag(Tok.getLocation(), diag::err_templated_invalid_declaration)
168 << TemplateInfo.getSourceRange();
169 // Parse the static_assert declaration to improve error recovery.
170 return Actions.ConvertDeclToDeclGroup(
171 Ptr: ParseStaticAssertDeclaration(DeclEnd));
172 }
173
174 // We are parsing a member template.
175 if (Context == DeclaratorContext::Member)
176 return ParseCXXClassMemberDeclaration(AS, Attr&: AccessAttrs, TemplateInfo,
177 DiagsFromTParams: &DiagsFromTParams);
178
179 ParsedAttributes DeclAttrs(AttrFactory);
180 ParsedAttributes DeclSpecAttrs(AttrFactory);
181
182 // GNU attributes are applied to the declaration specification while the
183 // standard attributes are applied to the declaration. We parse the two
184 // attribute sets into different containters so we can apply them during
185 // the regular parsing process.
186 while (MaybeParseCXX11Attributes(Attrs&: DeclAttrs) ||
187 MaybeParseGNUAttributes(Attrs&: DeclSpecAttrs))
188 ;
189
190 if (Tok.is(K: tok::kw_using))
191 return ParseUsingDirectiveOrDeclaration(Context, TemplateInfo, DeclEnd,
192 Attrs&: DeclAttrs);
193
194 // Parse the declaration specifiers, stealing any diagnostics from
195 // the template parameters.
196 ParsingDeclSpec DS(*this, &DiagsFromTParams);
197 DS.SetRangeStart(DeclSpecAttrs.Range.getBegin());
198 DS.SetRangeEnd(DeclSpecAttrs.Range.getEnd());
199 DS.takeAttributesFrom(attrs&: DeclSpecAttrs);
200
201 ParseDeclarationSpecifiers(DS, TemplateInfo, AS,
202 DSC: getDeclSpecContextFromDeclaratorContext(Context));
203
204 if (Tok.is(K: tok::semi)) {
205 ProhibitAttributes(Attrs&: DeclAttrs);
206 DeclEnd = ConsumeToken();
207 RecordDecl *AnonRecord = nullptr;
208 Decl *Decl = Actions.ParsedFreeStandingDeclSpec(
209 S: getCurScope(), AS, DS, DeclAttrs: ParsedAttributesView::none(),
210 TemplateParams: TemplateInfo.TemplateParams ? *TemplateInfo.TemplateParams
211 : MultiTemplateParamsArg(),
212 IsExplicitInstantiation: TemplateInfo.Kind == ParsedTemplateKind::ExplicitInstantiation,
213 AnonRecord);
214 Actions.ActOnDefinedDeclarationSpecifier(D: Decl);
215 assert(!AnonRecord &&
216 "Anonymous unions/structs should not be valid with template");
217 DS.complete(D: Decl);
218 return Actions.ConvertDeclToDeclGroup(Ptr: Decl);
219 }
220
221 if (DS.hasTagDefinition())
222 Actions.ActOnDefinedDeclarationSpecifier(D: DS.getRepAsDecl());
223
224 // Move the attributes from the prefix into the DS.
225 if (TemplateInfo.Kind == ParsedTemplateKind::ExplicitInstantiation)
226 ProhibitAttributes(Attrs&: DeclAttrs);
227
228 return ParseDeclGroup(DS, Context, Attrs&: DeclAttrs, TemplateInfo, DeclEnd: &DeclEnd);
229}
230
231Decl *
232Parser::ParseConceptDefinition(const ParsedTemplateInfo &TemplateInfo,
233 SourceLocation &DeclEnd) {
234 assert(TemplateInfo.Kind != ParsedTemplateKind::NonTemplate &&
235 "Template information required");
236 assert(Tok.is(tok::kw_concept) &&
237 "ParseConceptDefinition must be called when at a 'concept' keyword");
238
239 ConsumeToken(); // Consume 'concept'
240
241 SourceLocation BoolKWLoc;
242 if (TryConsumeToken(tok::kw_bool, BoolKWLoc))
243 Diag(Tok.getLocation(), diag::err_concept_legacy_bool_keyword) <<
244 FixItHint::CreateRemoval(SourceLocation(BoolKWLoc));
245
246 DiagnoseAndSkipCXX11Attributes();
247
248 CXXScopeSpec SS;
249 if (ParseOptionalCXXScopeSpecifier(
250 SS, /*ObjectType=*/nullptr,
251 /*ObjectHasErrors=*/false, /*EnteringContext=*/false,
252 /*MayBePseudoDestructor=*/nullptr,
253 /*IsTypename=*/false, /*LastII=*/nullptr, /*OnlyNamespace=*/true) ||
254 SS.isInvalid()) {
255 SkipUntil(T: tok::semi);
256 return nullptr;
257 }
258
259 if (SS.isNotEmpty())
260 Diag(SS.getBeginLoc(),
261 diag::err_concept_definition_not_identifier);
262
263 UnqualifiedId Result;
264 if (ParseUnqualifiedId(SS, /*ObjectType=*/nullptr,
265 /*ObjectHadErrors=*/false, /*EnteringContext=*/false,
266 /*AllowDestructorName=*/false,
267 /*AllowConstructorName=*/false,
268 /*AllowDeductionGuide=*/false,
269 /*TemplateKWLoc=*/nullptr, Result)) {
270 SkipUntil(T: tok::semi);
271 return nullptr;
272 }
273
274 if (Result.getKind() != UnqualifiedIdKind::IK_Identifier) {
275 Diag(Result.getBeginLoc(), diag::err_concept_definition_not_identifier);
276 SkipUntil(T: tok::semi);
277 return nullptr;
278 }
279
280 const IdentifierInfo *Id = Result.Identifier;
281 SourceLocation IdLoc = Result.getBeginLoc();
282
283 // [C++26][basic.scope.pdecl]/p13
284 // The locus of a concept-definition is immediately after its concept-name.
285 ConceptDecl *D = Actions.ActOnStartConceptDefinition(
286 S: getCurScope(), TemplateParameterLists: *TemplateInfo.TemplateParams, Name: Id, NameLoc: IdLoc);
287
288 ParsedAttributes Attrs(AttrFactory);
289 MaybeParseAttributes(WhichAttrKinds: PAKM_GNU | PAKM_CXX11, Attrs);
290
291 if (!TryConsumeToken(Expected: tok::equal)) {
292 Diag(Tok.getLocation(), diag::err_expected) << tok::equal;
293 SkipUntil(T: tok::semi);
294 if (D)
295 D->setInvalidDecl();
296 return nullptr;
297 }
298
299 ExprResult ConstraintExprResult =
300 Actions.CorrectDelayedTyposInExpr(ER: ParseConstraintExpression());
301 if (ConstraintExprResult.isInvalid()) {
302 SkipUntil(T: tok::semi);
303 if (D)
304 D->setInvalidDecl();
305 return nullptr;
306 }
307
308 DeclEnd = Tok.getLocation();
309 ExpectAndConsumeSemi(diag::err_expected_semi_declaration);
310 Expr *ConstraintExpr = ConstraintExprResult.get();
311
312 if (!D)
313 return nullptr;
314
315 return Actions.ActOnFinishConceptDefinition(S: getCurScope(), C: D, ConstraintExpr,
316 Attrs);
317}
318
319bool Parser::ParseTemplateParameters(
320 MultiParseScope &TemplateScopes, unsigned Depth,
321 SmallVectorImpl<NamedDecl *> &TemplateParams, SourceLocation &LAngleLoc,
322 SourceLocation &RAngleLoc) {
323 // Get the template parameter list.
324 if (!TryConsumeToken(Expected: tok::less, Loc&: LAngleLoc)) {
325 Diag(Tok.getLocation(), diag::err_expected_less_after) << "template";
326 return true;
327 }
328
329 // Try to parse the template parameter list.
330 bool Failed = false;
331 // FIXME: Missing greatergreatergreater support.
332 if (!Tok.is(K: tok::greater) && !Tok.is(K: tok::greatergreater)) {
333 TemplateScopes.Enter(ScopeFlags: Scope::TemplateParamScope);
334 Failed = ParseTemplateParameterList(Depth, TemplateParams);
335 }
336
337 if (Tok.is(K: tok::greatergreater)) {
338 // No diagnostic required here: a template-parameter-list can only be
339 // followed by a declaration or, for a template template parameter, the
340 // 'class' keyword. Therefore, the second '>' will be diagnosed later.
341 // This matters for elegant diagnosis of:
342 // template<template<typename>> struct S;
343 Tok.setKind(tok::greater);
344 RAngleLoc = Tok.getLocation();
345 Tok.setLocation(Tok.getLocation().getLocWithOffset(Offset: 1));
346 } else if (!TryConsumeToken(Expected: tok::greater, Loc&: RAngleLoc) && Failed) {
347 Diag(Tok.getLocation(), diag::err_expected) << tok::greater;
348 return true;
349 }
350 return false;
351}
352
353bool
354Parser::ParseTemplateParameterList(const unsigned Depth,
355 SmallVectorImpl<NamedDecl*> &TemplateParams) {
356 while (true) {
357
358 if (NamedDecl *TmpParam
359 = ParseTemplateParameter(Depth, Position: TemplateParams.size())) {
360 TemplateParams.push_back(Elt: TmpParam);
361 } else {
362 // If we failed to parse a template parameter, skip until we find
363 // a comma or closing brace.
364 SkipUntil(T1: tok::comma, T2: tok::greater, T3: tok::greatergreater,
365 Flags: StopAtSemi | StopBeforeMatch);
366 }
367
368 // Did we find a comma or the end of the template parameter list?
369 if (Tok.is(K: tok::comma)) {
370 ConsumeToken();
371 } else if (Tok.isOneOf(K1: tok::greater, K2: tok::greatergreater)) {
372 // Don't consume this... that's done by template parser.
373 break;
374 } else {
375 // Somebody probably forgot to close the template. Skip ahead and
376 // try to get out of the expression. This error is currently
377 // subsumed by whatever goes on in ParseTemplateParameter.
378 Diag(Tok.getLocation(), diag::err_expected_comma_greater);
379 SkipUntil(T1: tok::comma, T2: tok::greater, T3: tok::greatergreater,
380 Flags: StopAtSemi | StopBeforeMatch);
381 return false;
382 }
383 }
384 return true;
385}
386
387Parser::TPResult Parser::isStartOfTemplateTypeParameter() {
388 if (Tok.is(K: tok::kw_class)) {
389 // "class" may be the start of an elaborated-type-specifier or a
390 // type-parameter. Per C++ [temp.param]p3, we prefer the type-parameter.
391 switch (NextToken().getKind()) {
392 case tok::equal:
393 case tok::comma:
394 case tok::greater:
395 case tok::greatergreater:
396 case tok::ellipsis:
397 return TPResult::True;
398
399 case tok::identifier:
400 // This may be either a type-parameter or an elaborated-type-specifier.
401 // We have to look further.
402 break;
403
404 default:
405 return TPResult::False;
406 }
407
408 switch (GetLookAheadToken(N: 2).getKind()) {
409 case tok::equal:
410 case tok::comma:
411 case tok::greater:
412 case tok::greatergreater:
413 return TPResult::True;
414
415 default:
416 return TPResult::False;
417 }
418 }
419
420 if (TryAnnotateTypeConstraint())
421 return TPResult::Error;
422
423 if (isTypeConstraintAnnotation() &&
424 // Next token might be 'auto' or 'decltype', indicating that this
425 // type-constraint is in fact part of a placeholder-type-specifier of a
426 // non-type template parameter.
427 !GetLookAheadToken(N: Tok.is(K: tok::annot_cxxscope) ? 2 : 1)
428 .isOneOf(K1: tok::kw_auto, K2: tok::kw_decltype))
429 return TPResult::True;
430
431 // 'typedef' is a reasonably-common typo/thinko for 'typename', and is
432 // ill-formed otherwise.
433 if (Tok.isNot(K: tok::kw_typename) && Tok.isNot(K: tok::kw_typedef))
434 return TPResult::False;
435
436 // C++ [temp.param]p2:
437 // There is no semantic difference between class and typename in a
438 // template-parameter. typename followed by an unqualified-id
439 // names a template type parameter. typename followed by a
440 // qualified-id denotes the type in a non-type
441 // parameter-declaration.
442 Token Next = NextToken();
443
444 // If we have an identifier, skip over it.
445 if (Next.getKind() == tok::identifier)
446 Next = GetLookAheadToken(N: 2);
447
448 switch (Next.getKind()) {
449 case tok::equal:
450 case tok::comma:
451 case tok::greater:
452 case tok::greatergreater:
453 case tok::ellipsis:
454 return TPResult::True;
455
456 case tok::kw_typename:
457 case tok::kw_typedef:
458 case tok::kw_class:
459 // These indicate that a comma was missed after a type parameter, not that
460 // we have found a non-type parameter.
461 return TPResult::True;
462
463 default:
464 return TPResult::False;
465 }
466}
467
468NamedDecl *Parser::ParseTemplateParameter(unsigned Depth, unsigned Position) {
469
470 switch (isStartOfTemplateTypeParameter()) {
471 case TPResult::True:
472 // Is there just a typo in the input code? ('typedef' instead of
473 // 'typename')
474 if (Tok.is(K: tok::kw_typedef)) {
475 Diag(Tok.getLocation(), diag::err_expected_template_parameter);
476
477 Diag(Tok.getLocation(), diag::note_meant_to_use_typename)
478 << FixItHint::CreateReplacement(CharSourceRange::getCharRange(
479 Tok.getLocation(),
480 Tok.getEndLoc()),
481 "typename");
482
483 Tok.setKind(tok::kw_typename);
484 }
485
486 return ParseTypeParameter(Depth, Position);
487 case TPResult::False:
488 break;
489
490 case TPResult::Error: {
491 // We return an invalid parameter as opposed to null to avoid having bogus
492 // diagnostics about an empty template parameter list.
493 // FIXME: Fix ParseTemplateParameterList to better handle nullptr results
494 // from here.
495 // Return a NTTP as if there was an error in a scope specifier, the user
496 // probably meant to write the type of a NTTP.
497 DeclSpec DS(getAttrFactory());
498 DS.SetTypeSpecError();
499 Declarator D(DS, ParsedAttributesView::none(),
500 DeclaratorContext::TemplateParam);
501 D.SetIdentifier(Id: nullptr, IdLoc: Tok.getLocation());
502 D.setInvalidType(true);
503 NamedDecl *ErrorParam = Actions.ActOnNonTypeTemplateParameter(
504 S: getCurScope(), D, Depth, Position, /*EqualLoc=*/SourceLocation(),
505 /*DefaultArg=*/nullptr);
506 ErrorParam->setInvalidDecl(true);
507 SkipUntil(T1: tok::comma, T2: tok::greater, T3: tok::greatergreater,
508 Flags: StopAtSemi | StopBeforeMatch);
509 return ErrorParam;
510 }
511
512 case TPResult::Ambiguous:
513 llvm_unreachable("template param classification can't be ambiguous");
514 }
515
516 if (Tok.is(K: tok::kw_template))
517 return ParseTemplateTemplateParameter(Depth, Position);
518
519 // If it's none of the above, then it must be a parameter declaration.
520 // NOTE: This will pick up errors in the closure of the template parameter
521 // list (e.g., template < ; Check here to implement >> style closures.
522 return ParseNonTypeTemplateParameter(Depth, Position);
523}
524
525bool Parser::isTypeConstraintAnnotation() {
526 const Token &T = Tok.is(K: tok::annot_cxxscope) ? NextToken() : Tok;
527 if (T.isNot(K: tok::annot_template_id))
528 return false;
529 const auto *ExistingAnnot =
530 static_cast<TemplateIdAnnotation *>(T.getAnnotationValue());
531 return ExistingAnnot->Kind == TNK_Concept_template;
532}
533
534bool Parser::TryAnnotateTypeConstraint() {
535 if (!getLangOpts().CPlusPlus20)
536 return false;
537 CXXScopeSpec SS;
538 bool WasScopeAnnotation = Tok.is(K: tok::annot_cxxscope);
539 if (ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/nullptr,
540 /*ObjectHasErrors=*/false,
541 /*EnteringContext=*/false,
542 /*MayBePseudoDestructor=*/nullptr,
543 // If this is not a type-constraint, then
544 // this scope-spec is part of the typename
545 // of a non-type template parameter
546 /*IsTypename=*/true, /*LastII=*/nullptr,
547 // We won't find concepts in
548 // non-namespaces anyway, so might as well
549 // parse this correctly for possible type
550 // names.
551 /*OnlyNamespace=*/false))
552 return true;
553
554 if (Tok.is(K: tok::identifier)) {
555 UnqualifiedId PossibleConceptName;
556 PossibleConceptName.setIdentifier(Id: Tok.getIdentifierInfo(),
557 IdLoc: Tok.getLocation());
558
559 TemplateTy PossibleConcept;
560 bool MemberOfUnknownSpecialization = false;
561 auto TNK = Actions.isTemplateName(S: getCurScope(), SS,
562 /*hasTemplateKeyword=*/false,
563 Name: PossibleConceptName,
564 /*ObjectType=*/ParsedType(),
565 /*EnteringContext=*/false,
566 Template&: PossibleConcept,
567 MemberOfUnknownSpecialization,
568 /*Disambiguation=*/true);
569 if (MemberOfUnknownSpecialization || !PossibleConcept ||
570 TNK != TNK_Concept_template) {
571 if (SS.isNotEmpty())
572 AnnotateScopeToken(SS, IsNewAnnotation: !WasScopeAnnotation);
573 return false;
574 }
575
576 // At this point we're sure we're dealing with a constrained parameter. It
577 // may or may not have a template parameter list following the concept
578 // name.
579 if (AnnotateTemplateIdToken(Template: PossibleConcept, TNK, SS,
580 /*TemplateKWLoc=*/SourceLocation(),
581 TemplateName&: PossibleConceptName,
582 /*AllowTypeAnnotation=*/false,
583 /*TypeConstraint=*/true))
584 return true;
585 }
586
587 if (SS.isNotEmpty())
588 AnnotateScopeToken(SS, IsNewAnnotation: !WasScopeAnnotation);
589 return false;
590}
591
592NamedDecl *Parser::ParseTypeParameter(unsigned Depth, unsigned Position) {
593 assert((Tok.isOneOf(tok::kw_class, tok::kw_typename) ||
594 isTypeConstraintAnnotation()) &&
595 "A type-parameter starts with 'class', 'typename' or a "
596 "type-constraint");
597
598 CXXScopeSpec TypeConstraintSS;
599 TemplateIdAnnotation *TypeConstraint = nullptr;
600 bool TypenameKeyword = false;
601 SourceLocation KeyLoc;
602 ParseOptionalCXXScopeSpecifier(SS&: TypeConstraintSS, /*ObjectType=*/nullptr,
603 /*ObjectHasErrors=*/false,
604 /*EnteringContext*/ false);
605 if (Tok.is(K: tok::annot_template_id)) {
606 // Consume the 'type-constraint'.
607 TypeConstraint =
608 static_cast<TemplateIdAnnotation *>(Tok.getAnnotationValue());
609 assert(TypeConstraint->Kind == TNK_Concept_template &&
610 "stray non-concept template-id annotation");
611 KeyLoc = ConsumeAnnotationToken();
612 } else {
613 assert(TypeConstraintSS.isEmpty() &&
614 "expected type constraint after scope specifier");
615
616 // Consume the 'class' or 'typename' keyword.
617 TypenameKeyword = Tok.is(K: tok::kw_typename);
618 KeyLoc = ConsumeToken();
619 }
620
621 // Grab the ellipsis (if given).
622 SourceLocation EllipsisLoc;
623 if (TryConsumeToken(Expected: tok::ellipsis, Loc&: EllipsisLoc)) {
624 Diag(EllipsisLoc,
625 getLangOpts().CPlusPlus11
626 ? diag::warn_cxx98_compat_variadic_templates
627 : diag::ext_variadic_templates);
628 }
629
630 // Grab the template parameter name (if given)
631 SourceLocation NameLoc = Tok.getLocation();
632 IdentifierInfo *ParamName = nullptr;
633 if (Tok.is(K: tok::identifier)) {
634 ParamName = Tok.getIdentifierInfo();
635 ConsumeToken();
636 } else if (Tok.isOneOf(K1: tok::equal, Ks: tok::comma, Ks: tok::greater,
637 Ks: tok::greatergreater)) {
638 // Unnamed template parameter. Don't have to do anything here, just
639 // don't consume this token.
640 } else {
641 Diag(Tok.getLocation(), diag::err_expected) << tok::identifier;
642 return nullptr;
643 }
644
645 // Recover from misplaced ellipsis.
646 bool AlreadyHasEllipsis = EllipsisLoc.isValid();
647 if (TryConsumeToken(Expected: tok::ellipsis, Loc&: EllipsisLoc))
648 DiagnoseMisplacedEllipsis(EllipsisLoc, CorrectLoc: NameLoc, AlreadyHasEllipsis, IdentifierHasName: true);
649
650 // Grab a default argument (if available).
651 // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
652 // we introduce the type parameter into the local scope.
653 SourceLocation EqualLoc;
654 ParsedType DefaultArg;
655 std::optional<DelayTemplateIdDestructionRAII> DontDestructTemplateIds;
656 if (TryConsumeToken(Expected: tok::equal, Loc&: EqualLoc)) {
657 // The default argument might contain a lambda declaration; avoid destroying
658 // parsed template ids at the end of that declaration because they can be
659 // used in a type constraint later.
660 DontDestructTemplateIds.emplace(args&: *this, /*DelayTemplateIdDestruction=*/args: true);
661 // The default argument may declare template parameters, notably
662 // if it contains a generic lambda, so we need to increase
663 // the template depth as these parameters would not be instantiated
664 // at the current level.
665 TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
666 ++CurTemplateDepthTracker;
667 DefaultArg =
668 ParseTypeName(/*Range=*/nullptr, Context: DeclaratorContext::TemplateTypeArg)
669 .get();
670 }
671
672 NamedDecl *NewDecl = Actions.ActOnTypeParameter(S: getCurScope(),
673 Typename: TypenameKeyword, EllipsisLoc,
674 KeyLoc, ParamName, ParamNameLoc: NameLoc,
675 Depth, Position, EqualLoc,
676 DefaultArg,
677 HasTypeConstraint: TypeConstraint != nullptr);
678
679 if (TypeConstraint) {
680 Actions.ActOnTypeConstraint(SS: TypeConstraintSS, TypeConstraint,
681 ConstrainedParameter: cast<TemplateTypeParmDecl>(Val: NewDecl),
682 EllipsisLoc);
683 }
684
685 return NewDecl;
686}
687
688NamedDecl *Parser::ParseTemplateTemplateParameter(unsigned Depth,
689 unsigned Position) {
690 assert(Tok.is(tok::kw_template) && "Expected 'template' keyword");
691
692 // Handle the template <...> part.
693 SourceLocation TemplateLoc = ConsumeToken();
694 SmallVector<NamedDecl*,8> TemplateParams;
695 SourceLocation LAngleLoc, RAngleLoc;
696 ExprResult OptionalRequiresClauseConstraintER;
697 {
698 MultiParseScope TemplateParmScope(*this);
699 if (ParseTemplateParameters(TemplateScopes&: TemplateParmScope, Depth: Depth + 1, TemplateParams,
700 LAngleLoc, RAngleLoc)) {
701 return nullptr;
702 }
703 if (TryConsumeToken(Expected: tok::kw_requires)) {
704 OptionalRequiresClauseConstraintER =
705 Actions.ActOnRequiresClause(ConstraintExpr: ParseConstraintLogicalOrExpression(
706 /*IsTrailingRequiresClause=*/false));
707 if (!OptionalRequiresClauseConstraintER.isUsable()) {
708 SkipUntil(T1: tok::comma, T2: tok::greater, T3: tok::greatergreater,
709 Flags: StopAtSemi | StopBeforeMatch);
710 return nullptr;
711 }
712 }
713 }
714
715 // Provide an ExtWarn if the C++1z feature of using 'typename' here is used.
716 // Generate a meaningful error if the user forgot to put class before the
717 // identifier, comma, or greater. Provide a fixit if the identifier, comma,
718 // or greater appear immediately or after 'struct'. In the latter case,
719 // replace the keyword with 'class'.
720 bool TypenameKeyword = false;
721 if (!TryConsumeToken(Expected: tok::kw_class)) {
722 bool Replace = Tok.isOneOf(K1: tok::kw_typename, K2: tok::kw_struct);
723 const Token &Next = Tok.is(K: tok::kw_struct) ? NextToken() : Tok;
724 if (Tok.is(K: tok::kw_typename)) {
725 TypenameKeyword = true;
726 Diag(Tok.getLocation(),
727 getLangOpts().CPlusPlus17
728 ? diag::warn_cxx14_compat_template_template_param_typename
729 : diag::ext_template_template_param_typename)
730 << (!getLangOpts().CPlusPlus17
731 ? FixItHint::CreateReplacement(Tok.getLocation(), "class")
732 : FixItHint());
733 } else if (Next.isOneOf(K1: tok::identifier, Ks: tok::comma, Ks: tok::greater,
734 Ks: tok::greatergreater, Ks: tok::ellipsis)) {
735 Diag(Tok.getLocation(), diag::err_class_on_template_template_param)
736 << getLangOpts().CPlusPlus17
737 << (Replace
738 ? FixItHint::CreateReplacement(Tok.getLocation(), "class")
739 : FixItHint::CreateInsertion(Tok.getLocation(), "class "));
740 } else
741 Diag(Tok.getLocation(), diag::err_class_on_template_template_param)
742 << getLangOpts().CPlusPlus17;
743
744 if (Replace)
745 ConsumeToken();
746 }
747
748 // Parse the ellipsis, if given.
749 SourceLocation EllipsisLoc;
750 if (TryConsumeToken(tok::ellipsis, EllipsisLoc))
751 Diag(EllipsisLoc,
752 getLangOpts().CPlusPlus11
753 ? diag::warn_cxx98_compat_variadic_templates
754 : diag::ext_variadic_templates);
755
756 // Get the identifier, if given.
757 SourceLocation NameLoc = Tok.getLocation();
758 IdentifierInfo *ParamName = nullptr;
759 if (Tok.is(K: tok::identifier)) {
760 ParamName = Tok.getIdentifierInfo();
761 ConsumeToken();
762 } else if (Tok.isOneOf(K1: tok::equal, Ks: tok::comma, Ks: tok::greater,
763 Ks: tok::greatergreater)) {
764 // Unnamed template parameter. Don't have to do anything here, just
765 // don't consume this token.
766 } else {
767 Diag(Tok.getLocation(), diag::err_expected) << tok::identifier;
768 return nullptr;
769 }
770
771 // Recover from misplaced ellipsis.
772 bool AlreadyHasEllipsis = EllipsisLoc.isValid();
773 if (TryConsumeToken(Expected: tok::ellipsis, Loc&: EllipsisLoc))
774 DiagnoseMisplacedEllipsis(EllipsisLoc, CorrectLoc: NameLoc, AlreadyHasEllipsis, IdentifierHasName: true);
775
776 TemplateParameterList *ParamList = Actions.ActOnTemplateParameterList(
777 Depth, ExportLoc: SourceLocation(), TemplateLoc, LAngleLoc, Params: TemplateParams,
778 RAngleLoc, RequiresClause: OptionalRequiresClauseConstraintER.get());
779
780 // Grab a default argument (if available).
781 // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
782 // we introduce the template parameter into the local scope.
783 SourceLocation EqualLoc;
784 ParsedTemplateArgument DefaultArg;
785 if (TryConsumeToken(Expected: tok::equal, Loc&: EqualLoc)) {
786 DefaultArg = ParseTemplateTemplateArgument();
787 if (DefaultArg.isInvalid()) {
788 Diag(Tok.getLocation(),
789 diag::err_default_template_template_parameter_not_template);
790 SkipUntil(T1: tok::comma, T2: tok::greater, T3: tok::greatergreater,
791 Flags: StopAtSemi | StopBeforeMatch);
792 }
793 }
794
795 return Actions.ActOnTemplateTemplateParameter(
796 S: getCurScope(), TmpLoc: TemplateLoc, Params: ParamList, Typename: TypenameKeyword, EllipsisLoc,
797 ParamName, ParamNameLoc: NameLoc, Depth, Position, EqualLoc, DefaultArg);
798}
799
800NamedDecl *
801Parser::ParseNonTypeTemplateParameter(unsigned Depth, unsigned Position) {
802 // Parse the declaration-specifiers (i.e., the type).
803 // FIXME: The type should probably be restricted in some way... Not all
804 // declarators (parts of declarators?) are accepted for parameters.
805 DeclSpec DS(AttrFactory);
806 ParsedTemplateInfo TemplateInfo;
807 ParseDeclarationSpecifiers(DS, TemplateInfo, AS: AS_none,
808 DSC: DeclSpecContext::DSC_template_param);
809
810 // Parse this as a typename.
811 Declarator ParamDecl(DS, ParsedAttributesView::none(),
812 DeclaratorContext::TemplateParam);
813 ParseDeclarator(D&: ParamDecl);
814 if (DS.getTypeSpecType() == DeclSpec::TST_unspecified) {
815 Diag(Tok.getLocation(), diag::err_expected_template_parameter);
816 return nullptr;
817 }
818
819 // Recover from misplaced ellipsis.
820 SourceLocation EllipsisLoc;
821 if (TryConsumeToken(Expected: tok::ellipsis, Loc&: EllipsisLoc))
822 DiagnoseMisplacedEllipsisInDeclarator(EllipsisLoc, D&: ParamDecl);
823
824 // If there is a default value, parse it.
825 // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
826 // we introduce the template parameter into the local scope.
827 SourceLocation EqualLoc;
828 ExprResult DefaultArg;
829 if (TryConsumeToken(Expected: tok::equal, Loc&: EqualLoc)) {
830 if (Tok.is(K: tok::l_paren) && NextToken().is(K: tok::l_brace)) {
831 Diag(Tok.getLocation(), diag::err_stmt_expr_in_default_arg) << 1;
832 SkipUntil(T1: tok::comma, T2: tok::greater, Flags: StopAtSemi | StopBeforeMatch);
833 } else {
834 // C++ [temp.param]p15:
835 // When parsing a default template-argument for a non-type
836 // template-parameter, the first non-nested > is taken as the
837 // end of the template-parameter-list rather than a greater-than
838 // operator.
839 GreaterThanIsOperatorScope G(GreaterThanIsOperator, false);
840
841 // The default argument may declare template parameters, notably
842 // if it contains a generic lambda, so we need to increase
843 // the template depth as these parameters would not be instantiated
844 // at the current level.
845 TemplateParameterDepthRAII CurTemplateDepthTracker(
846 TemplateParameterDepth);
847 ++CurTemplateDepthTracker;
848 EnterExpressionEvaluationContext ConstantEvaluated(
849 Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated);
850 DefaultArg = Actions.ActOnConstantExpression(Res: ParseInitializer());
851 if (DefaultArg.isInvalid())
852 SkipUntil(T1: tok::comma, T2: tok::greater, Flags: StopAtSemi | StopBeforeMatch);
853 }
854 }
855
856 // Create the parameter.
857 return Actions.ActOnNonTypeTemplateParameter(S: getCurScope(), D&: ParamDecl,
858 Depth, Position, EqualLoc,
859 DefaultArg: DefaultArg.get());
860}
861
862void Parser::DiagnoseMisplacedEllipsis(SourceLocation EllipsisLoc,
863 SourceLocation CorrectLoc,
864 bool AlreadyHasEllipsis,
865 bool IdentifierHasName) {
866 FixItHint Insertion;
867 if (!AlreadyHasEllipsis)
868 Insertion = FixItHint::CreateInsertion(InsertionLoc: CorrectLoc, Code: "...");
869 Diag(EllipsisLoc, diag::err_misplaced_ellipsis_in_declaration)
870 << FixItHint::CreateRemoval(EllipsisLoc) << Insertion
871 << !IdentifierHasName;
872}
873
874void Parser::DiagnoseMisplacedEllipsisInDeclarator(SourceLocation EllipsisLoc,
875 Declarator &D) {
876 assert(EllipsisLoc.isValid());
877 bool AlreadyHasEllipsis = D.getEllipsisLoc().isValid();
878 if (!AlreadyHasEllipsis)
879 D.setEllipsisLoc(EllipsisLoc);
880 DiagnoseMisplacedEllipsis(EllipsisLoc, CorrectLoc: D.getIdentifierLoc(),
881 AlreadyHasEllipsis, IdentifierHasName: D.hasName());
882}
883
884bool Parser::ParseGreaterThanInTemplateList(SourceLocation LAngleLoc,
885 SourceLocation &RAngleLoc,
886 bool ConsumeLastToken,
887 bool ObjCGenericList) {
888 // What will be left once we've consumed the '>'.
889 tok::TokenKind RemainingToken;
890 const char *ReplacementStr = "> >";
891 bool MergeWithNextToken = false;
892
893 switch (Tok.getKind()) {
894 default:
895 Diag(getEndOfPreviousToken(), diag::err_expected) << tok::greater;
896 Diag(LAngleLoc, diag::note_matching) << tok::less;
897 return true;
898
899 case tok::greater:
900 // Determine the location of the '>' token. Only consume this token
901 // if the caller asked us to.
902 RAngleLoc = Tok.getLocation();
903 if (ConsumeLastToken)
904 ConsumeToken();
905 return false;
906
907 case tok::greatergreater:
908 RemainingToken = tok::greater;
909 break;
910
911 case tok::greatergreatergreater:
912 RemainingToken = tok::greatergreater;
913 break;
914
915 case tok::greaterequal:
916 RemainingToken = tok::equal;
917 ReplacementStr = "> =";
918
919 // Join two adjacent '=' tokens into one, for cases like:
920 // void (*p)() = f<int>;
921 // return f<int>==p;
922 if (NextToken().is(K: tok::equal) &&
923 areTokensAdjacent(A: Tok, B: NextToken())) {
924 RemainingToken = tok::equalequal;
925 MergeWithNextToken = true;
926 }
927 break;
928
929 case tok::greatergreaterequal:
930 RemainingToken = tok::greaterequal;
931 break;
932 }
933
934 // This template-id is terminated by a token that starts with a '>'.
935 // Outside C++11 and Objective-C, this is now error recovery.
936 //
937 // C++11 allows this when the token is '>>', and in CUDA + C++11 mode, we
938 // extend that treatment to also apply to the '>>>' token.
939 //
940 // Objective-C allows this in its type parameter / argument lists.
941
942 SourceLocation TokBeforeGreaterLoc = PrevTokLocation;
943 SourceLocation TokLoc = Tok.getLocation();
944 Token Next = NextToken();
945
946 // Whether splitting the current token after the '>' would undesirably result
947 // in the remaining token pasting with the token after it. This excludes the
948 // MergeWithNextToken cases, which we've already handled.
949 bool PreventMergeWithNextToken =
950 (RemainingToken == tok::greater ||
951 RemainingToken == tok::greatergreater) &&
952 (Next.isOneOf(K1: tok::greater, Ks: tok::greatergreater,
953 Ks: tok::greatergreatergreater, Ks: tok::equal, Ks: tok::greaterequal,
954 Ks: tok::greatergreaterequal, Ks: tok::equalequal)) &&
955 areTokensAdjacent(A: Tok, B: Next);
956
957 // Diagnose this situation as appropriate.
958 if (!ObjCGenericList) {
959 // The source range of the replaced token(s).
960 CharSourceRange ReplacementRange = CharSourceRange::getCharRange(
961 B: TokLoc, E: Lexer::AdvanceToTokenCharacter(TokStart: TokLoc, Characters: 2, SM: PP.getSourceManager(),
962 LangOpts: getLangOpts()));
963
964 // A hint to put a space between the '>>'s. In order to make the hint as
965 // clear as possible, we include the characters either side of the space in
966 // the replacement, rather than just inserting a space at SecondCharLoc.
967 FixItHint Hint1 = FixItHint::CreateReplacement(RemoveRange: ReplacementRange,
968 Code: ReplacementStr);
969
970 // A hint to put another space after the token, if it would otherwise be
971 // lexed differently.
972 FixItHint Hint2;
973 if (PreventMergeWithNextToken)
974 Hint2 = FixItHint::CreateInsertion(InsertionLoc: Next.getLocation(), Code: " ");
975
976 unsigned DiagId = diag::err_two_right_angle_brackets_need_space;
977 if (getLangOpts().CPlusPlus11 &&
978 (Tok.is(tok::greatergreater) || Tok.is(tok::greatergreatergreater)))
979 DiagId = diag::warn_cxx98_compat_two_right_angle_brackets;
980 else if (Tok.is(tok::greaterequal))
981 DiagId = diag::err_right_angle_bracket_equal_needs_space;
982 Diag(Loc: TokLoc, DiagID: DiagId) << Hint1 << Hint2;
983 }
984
985 // Find the "length" of the resulting '>' token. This is not always 1, as it
986 // can contain escaped newlines.
987 unsigned GreaterLength = Lexer::getTokenPrefixLength(
988 TokStart: TokLoc, CharNo: 1, SM: PP.getSourceManager(), LangOpts: getLangOpts());
989
990 // Annotate the source buffer to indicate that we split the token after the
991 // '>'. This allows us to properly find the end of, and extract the spelling
992 // of, the '>' token later.
993 RAngleLoc = PP.SplitToken(TokLoc, Length: GreaterLength);
994
995 // Strip the initial '>' from the token.
996 bool CachingTokens = PP.IsPreviousCachedToken(Tok);
997
998 Token Greater = Tok;
999 Greater.setLocation(RAngleLoc);
1000 Greater.setKind(tok::greater);
1001 Greater.setLength(GreaterLength);
1002
1003 unsigned OldLength = Tok.getLength();
1004 if (MergeWithNextToken) {
1005 ConsumeToken();
1006 OldLength += Tok.getLength();
1007 }
1008
1009 Tok.setKind(RemainingToken);
1010 Tok.setLength(OldLength - GreaterLength);
1011
1012 // Split the second token if lexing it normally would lex a different token
1013 // (eg, the fifth token in 'A<B>>>' should re-lex as '>', not '>>').
1014 SourceLocation AfterGreaterLoc = TokLoc.getLocWithOffset(Offset: GreaterLength);
1015 if (PreventMergeWithNextToken)
1016 AfterGreaterLoc = PP.SplitToken(TokLoc: AfterGreaterLoc, Length: Tok.getLength());
1017 Tok.setLocation(AfterGreaterLoc);
1018
1019 // Update the token cache to match what we just did if necessary.
1020 if (CachingTokens) {
1021 // If the previous cached token is being merged, delete it.
1022 if (MergeWithNextToken)
1023 PP.ReplacePreviousCachedToken(NewToks: {});
1024
1025 if (ConsumeLastToken)
1026 PP.ReplacePreviousCachedToken(NewToks: {Greater, Tok});
1027 else
1028 PP.ReplacePreviousCachedToken(NewToks: {Greater});
1029 }
1030
1031 if (ConsumeLastToken) {
1032 PrevTokLocation = RAngleLoc;
1033 } else {
1034 PrevTokLocation = TokBeforeGreaterLoc;
1035 PP.EnterToken(Tok, /*IsReinject=*/true);
1036 Tok = Greater;
1037 }
1038
1039 return false;
1040}
1041
1042bool Parser::ParseTemplateIdAfterTemplateName(bool ConsumeLastToken,
1043 SourceLocation &LAngleLoc,
1044 TemplateArgList &TemplateArgs,
1045 SourceLocation &RAngleLoc,
1046 TemplateTy Template) {
1047 assert(Tok.is(tok::less) && "Must have already parsed the template-name");
1048
1049 // Consume the '<'.
1050 LAngleLoc = ConsumeToken();
1051
1052 // Parse the optional template-argument-list.
1053 bool Invalid = false;
1054 {
1055 GreaterThanIsOperatorScope G(GreaterThanIsOperator, false);
1056 if (!Tok.isOneOf(K1: tok::greater, Ks: tok::greatergreater,
1057 Ks: tok::greatergreatergreater, Ks: tok::greaterequal,
1058 Ks: tok::greatergreaterequal))
1059 Invalid = ParseTemplateArgumentList(TemplateArgs, Template, OpenLoc: LAngleLoc);
1060
1061 if (Invalid) {
1062 // Try to find the closing '>'.
1063 if (getLangOpts().CPlusPlus11)
1064 SkipUntil(T1: tok::greater, T2: tok::greatergreater,
1065 T3: tok::greatergreatergreater, Flags: StopAtSemi | StopBeforeMatch);
1066 else
1067 SkipUntil(T: tok::greater, Flags: StopAtSemi | StopBeforeMatch);
1068 }
1069 }
1070
1071 return ParseGreaterThanInTemplateList(LAngleLoc, RAngleLoc, ConsumeLastToken,
1072 /*ObjCGenericList=*/false) ||
1073 Invalid;
1074}
1075
1076bool Parser::AnnotateTemplateIdToken(TemplateTy Template, TemplateNameKind TNK,
1077 CXXScopeSpec &SS,
1078 SourceLocation TemplateKWLoc,
1079 UnqualifiedId &TemplateName,
1080 bool AllowTypeAnnotation,
1081 bool TypeConstraint) {
1082 assert(getLangOpts().CPlusPlus && "Can only annotate template-ids in C++");
1083 assert((Tok.is(tok::less) || TypeConstraint) &&
1084 "Parser isn't at the beginning of a template-id");
1085 assert(!(TypeConstraint && AllowTypeAnnotation) && "type-constraint can't be "
1086 "a type annotation");
1087 assert((!TypeConstraint || TNK == TNK_Concept_template) && "type-constraint "
1088 "must accompany a concept name");
1089 assert((Template || TNK == TNK_Non_template) && "missing template name");
1090
1091 // Consume the template-name.
1092 SourceLocation TemplateNameLoc = TemplateName.getSourceRange().getBegin();
1093
1094 // Parse the enclosed template argument list.
1095 SourceLocation LAngleLoc, RAngleLoc;
1096 TemplateArgList TemplateArgs;
1097 bool ArgsInvalid = false;
1098 if (!TypeConstraint || Tok.is(K: tok::less)) {
1099 ArgsInvalid = ParseTemplateIdAfterTemplateName(
1100 ConsumeLastToken: false, LAngleLoc, TemplateArgs, RAngleLoc, Template);
1101 // If we couldn't recover from invalid arguments, don't form an annotation
1102 // token -- we don't know how much to annotate.
1103 // FIXME: This can lead to duplicate diagnostics if we retry parsing this
1104 // template-id in another context. Try to annotate anyway?
1105 if (RAngleLoc.isInvalid())
1106 return true;
1107 }
1108
1109 ASTTemplateArgsPtr TemplateArgsPtr(TemplateArgs);
1110
1111 // Build the annotation token.
1112 if (TNK == TNK_Type_template && AllowTypeAnnotation) {
1113 TypeResult Type = ArgsInvalid
1114 ? TypeError()
1115 : Actions.ActOnTemplateIdType(
1116 S: getCurScope(), SS, TemplateKWLoc, Template,
1117 TemplateII: TemplateName.Identifier, TemplateIILoc: TemplateNameLoc,
1118 LAngleLoc, TemplateArgs: TemplateArgsPtr, RAngleLoc);
1119
1120 Tok.setKind(tok::annot_typename);
1121 setTypeAnnotation(Tok, T: Type);
1122 if (SS.isNotEmpty())
1123 Tok.setLocation(SS.getBeginLoc());
1124 else if (TemplateKWLoc.isValid())
1125 Tok.setLocation(TemplateKWLoc);
1126 else
1127 Tok.setLocation(TemplateNameLoc);
1128 } else {
1129 // Build a template-id annotation token that can be processed
1130 // later.
1131 Tok.setKind(tok::annot_template_id);
1132
1133 const IdentifierInfo *TemplateII =
1134 TemplateName.getKind() == UnqualifiedIdKind::IK_Identifier
1135 ? TemplateName.Identifier
1136 : nullptr;
1137
1138 OverloadedOperatorKind OpKind =
1139 TemplateName.getKind() == UnqualifiedIdKind::IK_Identifier
1140 ? OO_None
1141 : TemplateName.OperatorFunctionId.Operator;
1142
1143 TemplateIdAnnotation *TemplateId = TemplateIdAnnotation::Create(
1144 TemplateKWLoc, TemplateNameLoc, Name: TemplateII, OperatorKind: OpKind, OpaqueTemplateName: Template, TemplateKind: TNK,
1145 LAngleLoc, RAngleLoc, TemplateArgs, ArgsInvalid, CleanupList&: TemplateIds);
1146
1147 Tok.setAnnotationValue(TemplateId);
1148 if (TemplateKWLoc.isValid())
1149 Tok.setLocation(TemplateKWLoc);
1150 else
1151 Tok.setLocation(TemplateNameLoc);
1152 }
1153
1154 // Common fields for the annotation token
1155 Tok.setAnnotationEndLoc(RAngleLoc);
1156
1157 // In case the tokens were cached, have Preprocessor replace them with the
1158 // annotation token.
1159 PP.AnnotateCachedTokens(Tok);
1160 return false;
1161}
1162
1163void Parser::AnnotateTemplateIdTokenAsType(
1164 CXXScopeSpec &SS, ImplicitTypenameContext AllowImplicitTypename,
1165 bool IsClassName) {
1166 assert(Tok.is(tok::annot_template_id) && "Requires template-id tokens");
1167
1168 TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(tok: Tok);
1169 assert(TemplateId->mightBeType() &&
1170 "Only works for type and dependent templates");
1171
1172 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
1173 TemplateId->NumArgs);
1174
1175 TypeResult Type =
1176 TemplateId->isInvalid()
1177 ? TypeError()
1178 : Actions.ActOnTemplateIdType(
1179 S: getCurScope(), SS, TemplateKWLoc: TemplateId->TemplateKWLoc,
1180 Template: TemplateId->Template, TemplateII: TemplateId->Name,
1181 TemplateIILoc: TemplateId->TemplateNameLoc, LAngleLoc: TemplateId->LAngleLoc,
1182 TemplateArgs: TemplateArgsPtr, RAngleLoc: TemplateId->RAngleLoc,
1183 /*IsCtorOrDtorName=*/false, IsClassName, AllowImplicitTypename);
1184 // Create the new "type" annotation token.
1185 Tok.setKind(tok::annot_typename);
1186 setTypeAnnotation(Tok, T: Type);
1187 if (SS.isNotEmpty()) // it was a C++ qualified type name.
1188 Tok.setLocation(SS.getBeginLoc());
1189 // End location stays the same
1190
1191 // Replace the template-id annotation token, and possible the scope-specifier
1192 // that precedes it, with the typename annotation token.
1193 PP.AnnotateCachedTokens(Tok);
1194}
1195
1196/// Determine whether the given token can end a template argument.
1197static bool isEndOfTemplateArgument(Token Tok) {
1198 // FIXME: Handle '>>>'.
1199 return Tok.isOneOf(K1: tok::comma, Ks: tok::greater, Ks: tok::greatergreater,
1200 Ks: tok::greatergreatergreater);
1201}
1202
1203ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() {
1204 if (!Tok.is(K: tok::identifier) && !Tok.is(K: tok::coloncolon) &&
1205 !Tok.is(K: tok::annot_cxxscope))
1206 return ParsedTemplateArgument();
1207
1208 // C++0x [temp.arg.template]p1:
1209 // A template-argument for a template template-parameter shall be the name
1210 // of a class template or an alias template, expressed as id-expression.
1211 //
1212 // We parse an id-expression that refers to a class template or alias
1213 // template. The grammar we parse is:
1214 //
1215 // nested-name-specifier[opt] template[opt] identifier ...[opt]
1216 //
1217 // followed by a token that terminates a template argument, such as ',',
1218 // '>', or (in some cases) '>>'.
1219 CXXScopeSpec SS; // nested-name-specifier, if present
1220 ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/nullptr,
1221 /*ObjectHasErrors=*/false,
1222 /*EnteringContext=*/false);
1223
1224 ParsedTemplateArgument Result;
1225 SourceLocation EllipsisLoc;
1226 if (SS.isSet() && Tok.is(K: tok::kw_template)) {
1227 // Parse the optional 'template' keyword following the
1228 // nested-name-specifier.
1229 SourceLocation TemplateKWLoc = ConsumeToken();
1230
1231 if (Tok.is(K: tok::identifier)) {
1232 // We appear to have a dependent template name.
1233 UnqualifiedId Name;
1234 Name.setIdentifier(Id: Tok.getIdentifierInfo(), IdLoc: Tok.getLocation());
1235 ConsumeToken(); // the identifier
1236
1237 TryConsumeToken(Expected: tok::ellipsis, Loc&: EllipsisLoc);
1238
1239 // If the next token signals the end of a template argument, then we have
1240 // a (possibly-dependent) template name that could be a template template
1241 // argument.
1242 TemplateTy Template;
1243 if (isEndOfTemplateArgument(Tok) &&
1244 Actions.ActOnTemplateName(S: getCurScope(), SS, TemplateKWLoc, Name,
1245 /*ObjectType=*/nullptr,
1246 /*EnteringContext=*/false, Template))
1247 Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
1248 }
1249 } else if (Tok.is(K: tok::identifier)) {
1250 // We may have a (non-dependent) template name.
1251 TemplateTy Template;
1252 UnqualifiedId Name;
1253 Name.setIdentifier(Id: Tok.getIdentifierInfo(), IdLoc: Tok.getLocation());
1254 ConsumeToken(); // the identifier
1255
1256 TryConsumeToken(Expected: tok::ellipsis, Loc&: EllipsisLoc);
1257
1258 if (isEndOfTemplateArgument(Tok)) {
1259 bool MemberOfUnknownSpecialization;
1260 TemplateNameKind TNK = Actions.isTemplateName(
1261 S: getCurScope(), SS,
1262 /*hasTemplateKeyword=*/false, Name,
1263 /*ObjectType=*/nullptr,
1264 /*EnteringContext=*/false, Template, MemberOfUnknownSpecialization);
1265 if (TNK == TNK_Dependent_template_name || TNK == TNK_Type_template) {
1266 // We have an id-expression that refers to a class template or
1267 // (C++0x) alias template.
1268 Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
1269 }
1270 }
1271 }
1272
1273 // If this is a pack expansion, build it as such.
1274 if (EllipsisLoc.isValid() && !Result.isInvalid())
1275 Result = Actions.ActOnPackExpansion(Arg: Result, EllipsisLoc);
1276
1277 return Result;
1278}
1279
1280ParsedTemplateArgument Parser::ParseTemplateArgument() {
1281 // C++ [temp.arg]p2:
1282 // In a template-argument, an ambiguity between a type-id and an
1283 // expression is resolved to a type-id, regardless of the form of
1284 // the corresponding template-parameter.
1285 //
1286 // Therefore, we initially try to parse a type-id - and isCXXTypeId might look
1287 // up and annotate an identifier as an id-expression during disambiguation,
1288 // so enter the appropriate context for a constant expression template
1289 // argument before trying to disambiguate.
1290
1291 EnterExpressionEvaluationContext EnterConstantEvaluated(
1292 Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated,
1293 /*LambdaContextDecl=*/nullptr,
1294 /*ExprContext=*/Sema::ExpressionEvaluationContextRecord::EK_TemplateArgument);
1295 if (isCXXTypeId(Context: TentativeCXXTypeIdContext::AsTemplateArgument)) {
1296 TypeResult TypeArg = ParseTypeName(
1297 /*Range=*/nullptr, Context: DeclaratorContext::TemplateArg);
1298 return Actions.ActOnTemplateTypeArgument(ParsedType: TypeArg);
1299 }
1300
1301 // Try to parse a template template argument.
1302 {
1303 TentativeParsingAction TPA(*this);
1304
1305 ParsedTemplateArgument TemplateTemplateArgument
1306 = ParseTemplateTemplateArgument();
1307 if (!TemplateTemplateArgument.isInvalid()) {
1308 TPA.Commit();
1309 return TemplateTemplateArgument;
1310 }
1311
1312 // Revert this tentative parse to parse a non-type template argument.
1313 TPA.Revert();
1314 }
1315
1316 // Parse a non-type template argument.
1317 ExprResult ExprArg;
1318 SourceLocation Loc = Tok.getLocation();
1319 if (getLangOpts().CPlusPlus11 && Tok.is(K: tok::l_brace))
1320 ExprArg = ParseBraceInitializer();
1321 else
1322 ExprArg =
1323 ParseConstantExpressionInExprEvalContext(isTypeCast: TypeCastState::MaybeTypeCast);
1324 if (ExprArg.isInvalid() || !ExprArg.get()) {
1325 return ParsedTemplateArgument();
1326 }
1327
1328 return ParsedTemplateArgument(ParsedTemplateArgument::NonType,
1329 ExprArg.get(), Loc);
1330}
1331
1332bool Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs,
1333 TemplateTy Template,
1334 SourceLocation OpenLoc) {
1335
1336 ColonProtectionRAIIObject ColonProtection(*this, false);
1337
1338 auto RunSignatureHelp = [&] {
1339 if (!Template)
1340 return QualType();
1341 CalledSignatureHelp = true;
1342 return Actions.CodeCompletion().ProduceTemplateArgumentSignatureHelp(
1343 Template, TemplateArgs, LAngleLoc: OpenLoc);
1344 };
1345
1346 do {
1347 PreferredType.enterFunctionArgument(Tok.getLocation(), RunSignatureHelp);
1348 ParsedTemplateArgument Arg = ParseTemplateArgument();
1349 SourceLocation EllipsisLoc;
1350 if (TryConsumeToken(Expected: tok::ellipsis, Loc&: EllipsisLoc))
1351 Arg = Actions.ActOnPackExpansion(Arg, EllipsisLoc);
1352
1353 if (Arg.isInvalid()) {
1354 if (PP.isCodeCompletionReached() && !CalledSignatureHelp)
1355 RunSignatureHelp();
1356 return true;
1357 }
1358
1359 // Save this template argument.
1360 TemplateArgs.push_back(Elt: Arg);
1361
1362 // If the next token is a comma, consume it and keep reading
1363 // arguments.
1364 } while (TryConsumeToken(Expected: tok::comma));
1365
1366 return false;
1367}
1368
1369Parser::DeclGroupPtrTy Parser::ParseExplicitInstantiation(
1370 DeclaratorContext Context, SourceLocation ExternLoc,
1371 SourceLocation TemplateLoc, SourceLocation &DeclEnd,
1372 ParsedAttributes &AccessAttrs, AccessSpecifier AS) {
1373 // This isn't really required here.
1374 ParsingDeclRAIIObject
1375 ParsingTemplateParams(*this, ParsingDeclRAIIObject::NoParent);
1376 ParsedTemplateInfo TemplateInfo(ExternLoc, TemplateLoc);
1377 return ParseDeclarationAfterTemplate(
1378 Context, TemplateInfo, DiagsFromTParams&: ParsingTemplateParams, DeclEnd, AccessAttrs, AS);
1379}
1380
1381SourceRange Parser::ParsedTemplateInfo::getSourceRange() const {
1382 if (TemplateParams)
1383 return getTemplateParamsRange(Params: TemplateParams->data(),
1384 NumParams: TemplateParams->size());
1385
1386 SourceRange R(TemplateLoc);
1387 if (ExternLoc.isValid())
1388 R.setBegin(ExternLoc);
1389 return R;
1390}
1391
1392void Parser::LateTemplateParserCallback(void *P, LateParsedTemplate &LPT) {
1393 ((Parser *)P)->ParseLateTemplatedFuncDef(LPT);
1394}
1395
1396void Parser::ParseLateTemplatedFuncDef(LateParsedTemplate &LPT) {
1397 if (!LPT.D)
1398 return;
1399
1400 // Destroy TemplateIdAnnotations when we're done, if possible.
1401 DestroyTemplateIdAnnotationsRAIIObj CleanupRAII(*this);
1402
1403 // Get the FunctionDecl.
1404 FunctionDecl *FunD = LPT.D->getAsFunction();
1405 // Track template parameter depth.
1406 TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
1407
1408 // To restore the context after late parsing.
1409 Sema::ContextRAII GlobalSavedContext(
1410 Actions, Actions.Context.getTranslationUnitDecl());
1411
1412 MultiParseScope Scopes(*this);
1413
1414 // Get the list of DeclContexts to reenter.
1415 SmallVector<DeclContext*, 4> DeclContextsToReenter;
1416 for (DeclContext *DC = FunD; DC && !DC->isTranslationUnit();
1417 DC = DC->getLexicalParent())
1418 DeclContextsToReenter.push_back(Elt: DC);
1419
1420 // Reenter scopes from outermost to innermost.
1421 for (DeclContext *DC : reverse(C&: DeclContextsToReenter)) {
1422 CurTemplateDepthTracker.addDepth(
1423 D: ReenterTemplateScopes(S&: Scopes, D: cast<Decl>(Val: DC)));
1424 Scopes.Enter(ScopeFlags: Scope::DeclScope);
1425 // We'll reenter the function context itself below.
1426 if (DC != FunD)
1427 Actions.PushDeclContext(S: Actions.getCurScope(), DC);
1428 }
1429
1430 // Parsing should occur with empty FP pragma stack and FP options used in the
1431 // point of the template definition.
1432 Sema::FpPragmaStackSaveRAII SavedStack(Actions);
1433 Actions.resetFPOptions(FPO: LPT.FPO);
1434
1435 assert(!LPT.Toks.empty() && "Empty body!");
1436
1437 // Append the current token at the end of the new token stream so that it
1438 // doesn't get lost.
1439 LPT.Toks.push_back(Elt: Tok);
1440 PP.EnterTokenStream(Toks: LPT.Toks, DisableMacroExpansion: true, /*IsReinject*/true);
1441
1442 // Consume the previously pushed token.
1443 ConsumeAnyToken(/*ConsumeCodeCompletionTok=*/true);
1444 assert(Tok.isOneOf(tok::l_brace, tok::colon, tok::kw_try) &&
1445 "Inline method not starting with '{', ':' or 'try'");
1446
1447 // Parse the method body. Function body parsing code is similar enough
1448 // to be re-used for method bodies as well.
1449 ParseScope FnScope(this, Scope::FnScope | Scope::DeclScope |
1450 Scope::CompoundStmtScope);
1451
1452 // Recreate the containing function DeclContext.
1453 Sema::ContextRAII FunctionSavedContext(Actions, FunD->getLexicalParent());
1454
1455 Actions.ActOnStartOfFunctionDef(getCurScope(), FunD);
1456
1457 if (Tok.is(K: tok::kw_try)) {
1458 ParseFunctionTryBlock(Decl: LPT.D, BodyScope&: FnScope);
1459 } else {
1460 if (Tok.is(K: tok::colon))
1461 ParseConstructorInitializer(ConstructorDecl: LPT.D);
1462 else
1463 Actions.ActOnDefaultCtorInitializers(CDtorDecl: LPT.D);
1464
1465 if (Tok.is(K: tok::l_brace)) {
1466 assert((!isa<FunctionTemplateDecl>(LPT.D) ||
1467 cast<FunctionTemplateDecl>(LPT.D)
1468 ->getTemplateParameters()
1469 ->getDepth() == TemplateParameterDepth - 1) &&
1470 "TemplateParameterDepth should be greater than the depth of "
1471 "current template being instantiated!");
1472 ParseFunctionStatementBody(Decl: LPT.D, BodyScope&: FnScope);
1473 Actions.UnmarkAsLateParsedTemplate(FD: FunD);
1474 } else
1475 Actions.ActOnFinishFunctionBody(Decl: LPT.D, Body: nullptr);
1476 }
1477}
1478
1479void Parser::LexTemplateFunctionForLateParsing(CachedTokens &Toks) {
1480 tok::TokenKind kind = Tok.getKind();
1481 if (!ConsumeAndStoreFunctionPrologue(Toks)) {
1482 // Consume everything up to (and including) the matching right brace.
1483 ConsumeAndStoreUntil(T1: tok::r_brace, Toks, /*StopAtSemi=*/false);
1484 }
1485
1486 // If we're in a function-try-block, we need to store all the catch blocks.
1487 if (kind == tok::kw_try) {
1488 while (Tok.is(K: tok::kw_catch)) {
1489 ConsumeAndStoreUntil(T1: tok::l_brace, Toks, /*StopAtSemi=*/false);
1490 ConsumeAndStoreUntil(T1: tok::r_brace, Toks, /*StopAtSemi=*/false);
1491 }
1492 }
1493}
1494
1495bool Parser::diagnoseUnknownTemplateId(ExprResult LHS, SourceLocation Less) {
1496 TentativeParsingAction TPA(*this);
1497 // FIXME: We could look at the token sequence in a lot more detail here.
1498 if (SkipUntil(T1: tok::greater, T2: tok::greatergreater, T3: tok::greatergreatergreater,
1499 Flags: StopAtSemi | StopBeforeMatch)) {
1500 TPA.Commit();
1501
1502 SourceLocation Greater;
1503 ParseGreaterThanInTemplateList(LAngleLoc: Less, RAngleLoc&: Greater, ConsumeLastToken: true, ObjCGenericList: false);
1504 Actions.diagnoseExprIntendedAsTemplateName(S: getCurScope(), TemplateName: LHS,
1505 Less, Greater);
1506 return true;
1507 }
1508
1509 // There's no matching '>' token, this probably isn't supposed to be
1510 // interpreted as a template-id. Parse it as an (ill-formed) comparison.
1511 TPA.Revert();
1512 return false;
1513}
1514
1515void Parser::checkPotentialAngleBracket(ExprResult &PotentialTemplateName) {
1516 assert(Tok.is(tok::less) && "not at a potential angle bracket");
1517
1518 bool DependentTemplateName = false;
1519 if (!Actions.mightBeIntendedToBeTemplateName(E: PotentialTemplateName,
1520 Dependent&: DependentTemplateName))
1521 return;
1522
1523 // OK, this might be a name that the user intended to be parsed as a
1524 // template-name, followed by a '<' token. Check for some easy cases.
1525
1526 // If we have potential_template<>, then it's supposed to be a template-name.
1527 if (NextToken().is(K: tok::greater) ||
1528 (getLangOpts().CPlusPlus11 &&
1529 NextToken().isOneOf(K1: tok::greatergreater, K2: tok::greatergreatergreater))) {
1530 SourceLocation Less = ConsumeToken();
1531 SourceLocation Greater;
1532 ParseGreaterThanInTemplateList(LAngleLoc: Less, RAngleLoc&: Greater, ConsumeLastToken: true, ObjCGenericList: false);
1533 Actions.diagnoseExprIntendedAsTemplateName(
1534 S: getCurScope(), TemplateName: PotentialTemplateName, Less, Greater);
1535 // FIXME: Perform error recovery.
1536 PotentialTemplateName = ExprError();
1537 return;
1538 }
1539
1540 // If we have 'potential_template<type-id', assume it's supposed to be a
1541 // template-name if there's a matching '>' later on.
1542 {
1543 // FIXME: Avoid the tentative parse when NextToken() can't begin a type.
1544 TentativeParsingAction TPA(*this);
1545 SourceLocation Less = ConsumeToken();
1546 if (isTypeIdUnambiguously() &&
1547 diagnoseUnknownTemplateId(LHS: PotentialTemplateName, Less)) {
1548 TPA.Commit();
1549 // FIXME: Perform error recovery.
1550 PotentialTemplateName = ExprError();
1551 return;
1552 }
1553 TPA.Revert();
1554 }
1555
1556 // Otherwise, remember that we saw this in case we see a potentially-matching
1557 // '>' token later on.
1558 AngleBracketTracker::Priority Priority =
1559 (DependentTemplateName ? AngleBracketTracker::DependentName
1560 : AngleBracketTracker::PotentialTypo) |
1561 (Tok.hasLeadingSpace() ? AngleBracketTracker::SpaceBeforeLess
1562 : AngleBracketTracker::NoSpaceBeforeLess);
1563 AngleBrackets.add(P&: *this, TemplateName: PotentialTemplateName.get(), LessLoc: Tok.getLocation(),
1564 Prio: Priority);
1565}
1566
1567bool Parser::checkPotentialAngleBracketDelimiter(
1568 const AngleBracketTracker::Loc &LAngle, const Token &OpToken) {
1569 // If a comma in an expression context is followed by a type that can be a
1570 // template argument and cannot be an expression, then this is ill-formed,
1571 // but might be intended to be part of a template-id.
1572 if (OpToken.is(K: tok::comma) && isTypeIdUnambiguously() &&
1573 diagnoseUnknownTemplateId(LHS: LAngle.TemplateName, Less: LAngle.LessLoc)) {
1574 AngleBrackets.clear(P&: *this);
1575 return true;
1576 }
1577
1578 // If a context that looks like a template-id is followed by '()', then
1579 // this is ill-formed, but might be intended to be a template-id
1580 // followed by '()'.
1581 if (OpToken.is(K: tok::greater) && Tok.is(K: tok::l_paren) &&
1582 NextToken().is(K: tok::r_paren)) {
1583 Actions.diagnoseExprIntendedAsTemplateName(
1584 S: getCurScope(), TemplateName: LAngle.TemplateName, Less: LAngle.LessLoc,
1585 Greater: OpToken.getLocation());
1586 AngleBrackets.clear(P&: *this);
1587 return true;
1588 }
1589
1590 // After a '>' (etc), we're no longer potentially in a construct that's
1591 // intended to be treated as a template-id.
1592 if (OpToken.is(K: tok::greater) ||
1593 (getLangOpts().CPlusPlus11 &&
1594 OpToken.isOneOf(K1: tok::greatergreater, K2: tok::greatergreatergreater)))
1595 AngleBrackets.clear(P&: *this);
1596 return false;
1597}
1598

source code of clang/lib/Parse/ParseTemplate.cpp