1	//===--- ParseExprCXX.cpp - C++ Expression 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 the Expression parsing implementation for C++.
10	//
11	//===----------------------------------------------------------------------===//
12	#include "clang/AST/ASTContext.h"
13	#include "clang/AST/Decl.h"
14	#include "clang/AST/DeclTemplate.h"
15	#include "clang/AST/ExprCXX.h"
16	#include "clang/Basic/DiagnosticParse.h"
17	#include "clang/Basic/PrettyStackTrace.h"
18	#include "clang/Basic/TemplateKinds.h"
19	#include "clang/Basic/TokenKinds.h"
20	#include "clang/Lex/LiteralSupport.h"
21	#include "clang/Parse/Parser.h"
22	#include "clang/Parse/RAIIObjectsForParser.h"
23	#include "clang/Sema/DeclSpec.h"
24	#include "clang/Sema/EnterExpressionEvaluationContext.h"
25	#include "clang/Sema/ParsedTemplate.h"
26	#include "clang/Sema/Scope.h"
27	#include "clang/Sema/SemaCodeCompletion.h"
28	#include "llvm/Support/Compiler.h"
29	#include "llvm/Support/ErrorHandling.h"
30	#include <numeric>
31
32	using namespace clang;
33
34	static int SelectDigraphErrorMessage(tok::TokenKind Kind) {
35	switch (Kind) {
36	// template name
37	case tok::unknown: return 0;
38	// casts
39	case tok::kw_addrspace_cast: return 1;
40	case tok::kw_const_cast: return 2;
41	case tok::kw_dynamic_cast: return 3;
42	case tok::kw_reinterpret_cast: return 4;
43	case tok::kw_static_cast: return 5;
44	default:
45	llvm_unreachable("Unknown type for digraph error message.");
46	}
47	}
48
49	bool Parser::areTokensAdjacent(const Token &First, const Token &Second) {
50	SourceManager &SM = PP.getSourceManager();
51	SourceLocation FirstLoc = SM.getSpellingLoc(Loc: First.getLocation());
52	SourceLocation FirstEnd = FirstLoc.getLocWithOffset(Offset: First.getLength());
53	return FirstEnd == SM.getSpellingLoc(Loc: Second.getLocation());
54	}
55
56	// Suggest fixit for "<::" after a cast.
57	static void FixDigraph(Parser &P, Preprocessor &PP, Token &DigraphToken,
58	Token &ColonToken, tok::TokenKind Kind, bool AtDigraph) {
59	// Pull '<:' and ':' off token stream.
60	if (!AtDigraph)
61	PP.Lex(Result&: DigraphToken);
62	PP.Lex(Result&: ColonToken);
63
64	SourceRange Range;
65	Range.setBegin(DigraphToken.getLocation());
66	Range.setEnd(ColonToken.getLocation());
67	P.Diag(DigraphToken.getLocation(), diag::err_missing_whitespace_digraph)
68	<< SelectDigraphErrorMessage(Kind)
69	<< FixItHint::CreateReplacement(Range, "< ::");
70
71	// Update token information to reflect their change in token type.
72	ColonToken.setKind(tok::coloncolon);
73	ColonToken.setLocation(ColonToken.getLocation().getLocWithOffset(Offset: -1));
74	ColonToken.setLength(2);
75	DigraphToken.setKind(tok::less);
76	DigraphToken.setLength(1);
77
78	// Push new tokens back to token stream.
79	PP.EnterToken(Tok: ColonToken, /*IsReinject*/ true);
80	if (!AtDigraph)
81	PP.EnterToken(Tok: DigraphToken, /*IsReinject*/ true);
82	}
83
84	void Parser::CheckForTemplateAndDigraph(Token &Next, ParsedType ObjectType,
85	bool EnteringContext,
86	IdentifierInfo &II, CXXScopeSpec &SS) {
87	if (!Next.is(K: tok::l_square) || Next.getLength() != 2)
88	return;
89
90	Token SecondToken = GetLookAheadToken(N: 2);
91	if (!SecondToken.is(K: tok::colon) || !areTokensAdjacent(First: Next, Second: SecondToken))
92	return;
93
94	TemplateTy Template;
95	UnqualifiedId TemplateName;
96	TemplateName.setIdentifier(Id: &II, IdLoc: Tok.getLocation());
97	bool MemberOfUnknownSpecialization;
98	if (!Actions.isTemplateName(S: getCurScope(), SS, /*hasTemplateKeyword=*/false,
99	Name: TemplateName, ObjectType, EnteringContext,
100	Template, MemberOfUnknownSpecialization))
101	return;
102
103	FixDigraph(P&: *this, PP, DigraphToken&: Next, ColonToken&: SecondToken, Kind: tok::unknown,
104	/*AtDigraph*/false);
105	}
106
107	bool Parser::ParseOptionalCXXScopeSpecifier(
108	CXXScopeSpec &SS, ParsedType ObjectType, bool ObjectHadErrors,
109	bool EnteringContext, bool *MayBePseudoDestructor, bool IsTypename,
110	const IdentifierInfo **LastII, bool OnlyNamespace, bool InUsingDeclaration,
111	bool Disambiguation) {
112	assert(getLangOpts().CPlusPlus &&
113	"Call sites of this function should be guarded by checking for C++");
114
115	if (Tok.is(K: tok::annot_cxxscope)) {
116	assert(!LastII && "want last identifier but have already annotated scope");
117	assert(!MayBePseudoDestructor && "unexpected annot_cxxscope");
118	Actions.RestoreNestedNameSpecifierAnnotation(Annotation: Tok.getAnnotationValue(),
119	AnnotationRange: Tok.getAnnotationRange(),
120	SS);
121	ConsumeAnnotationToken();
122	return false;
123	}
124
125	// Has to happen before any "return false"s in this function.
126	bool CheckForDestructor = false;
127	if (MayBePseudoDestructor && *MayBePseudoDestructor) {
128	CheckForDestructor = true;
129	*MayBePseudoDestructor = false;
130	}
131
132	if (LastII)
133	*LastII = nullptr;
134
135	bool HasScopeSpecifier = false;
136
137	if (Tok.is(K: tok::coloncolon)) {
138	// ::new and ::delete aren't nested-name-specifiers.
139	tok::TokenKind NextKind = NextToken().getKind();
140	if (NextKind == tok::kw_new || NextKind == tok::kw_delete)
141	return false;
142
143	if (NextKind == tok::l_brace) {
144	// It is invalid to have :: {, consume the scope qualifier and pretend
145	// like we never saw it.
146	Diag(ConsumeToken(), diag::err_expected) << tok::identifier;
147	} else {
148	// '::' - Global scope qualifier.
149	if (Actions.ActOnCXXGlobalScopeSpecifier(CCLoc: ConsumeToken(), SS))
150	return true;
151
152	HasScopeSpecifier = true;
153	}
154	}
155
156	if (Tok.is(K: tok::kw___super)) {
157	SourceLocation SuperLoc = ConsumeToken();
158	if (!Tok.is(K: tok::coloncolon)) {
159	Diag(Tok.getLocation(), diag::err_expected_coloncolon_after_super);
160	return true;
161	}
162
163	return Actions.ActOnSuperScopeSpecifier(SuperLoc, ColonColonLoc: ConsumeToken(), SS);
164	}
165
166	if (!HasScopeSpecifier &&
167	Tok.isOneOf(K1: tok::kw_decltype, K2: tok::annot_decltype)) {
168	DeclSpec DS(AttrFactory);
169	SourceLocation DeclLoc = Tok.getLocation();
170	SourceLocation EndLoc = ParseDecltypeSpecifier(DS);
171
172	SourceLocation CCLoc;
173	// Work around a standard defect: 'decltype(auto)::' is not a
174	// nested-name-specifier.
175	if (DS.getTypeSpecType() == DeclSpec::TST_decltype_auto ||
176	!TryConsumeToken(Expected: tok::coloncolon, Loc&: CCLoc)) {
177	AnnotateExistingDecltypeSpecifier(DS, StartLoc: DeclLoc, EndLoc);
178	return false;
179	}
180
181	if (Actions.ActOnCXXNestedNameSpecifierDecltype(SS, DS, ColonColonLoc: CCLoc))
182	SS.SetInvalid(SourceRange(DeclLoc, CCLoc));
183
184	HasScopeSpecifier = true;
185	}
186
187	else if (!HasScopeSpecifier && Tok.is(K: tok::identifier) &&
188	GetLookAheadToken(N: 1).is(K: tok::ellipsis) &&
189	GetLookAheadToken(N: 2).is(K: tok::l_square) &&
190	!GetLookAheadToken(N: 3).is(K: tok::r_square)) {
191	SourceLocation Start = Tok.getLocation();
192	DeclSpec DS(AttrFactory);
193	SourceLocation CCLoc;
194	SourceLocation EndLoc = ParsePackIndexingType(DS);
195	if (DS.getTypeSpecType() == DeclSpec::TST_error)
196	return false;
197
198	QualType Type = Actions.ActOnPackIndexingType(
199	Pattern: DS.getRepAsType().get(), IndexExpr: DS.getPackIndexingExpr(), Loc: DS.getBeginLoc(),
200	EllipsisLoc: DS.getEllipsisLoc());
201
202	if (Type.isNull())
203	return false;
204
205	// C++ [cpp23.dcl.dcl-2]:
206	// Previously, T...[n] would declare a pack of function parameters.
207	// T...[n] is now a pack-index-specifier. [...] Valid C++ 2023 code that
208	// declares a pack of parameters without specifying a declarator-id
209	// becomes ill-formed.
210	//
211	// However, we still treat it as a pack indexing type because the use case
212	// is fairly rare, to ensure semantic consistency given that we have
213	// backported this feature to pre-C++26 modes.
214	if (!Tok.is(tok::coloncolon) && !getLangOpts().CPlusPlus26 &&
215	getCurScope()->isFunctionDeclarationScope())
216	Diag(Start, diag::warn_pre_cxx26_ambiguous_pack_indexing_type) << Type;
217
218	if (!TryConsumeToken(Expected: tok::coloncolon, Loc&: CCLoc)) {
219	AnnotateExistingIndexedTypeNamePack(T: ParsedType::make(P: Type), StartLoc: Start,
220	EndLoc);
221	return false;
222	}
223	if (Actions.ActOnCXXNestedNameSpecifierIndexedPack(SS, DS, ColonColonLoc: CCLoc,
224	Type: std::move(Type)))
225	SS.SetInvalid(SourceRange(Start, CCLoc));
226	HasScopeSpecifier = true;
227	}
228
229	// Preferred type might change when parsing qualifiers, we need the original.
230	auto SavedType = PreferredType;
231	while (true) {
232	if (HasScopeSpecifier) {
233	if (Tok.is(K: tok::code_completion)) {
234	cutOffParsing();
235	// Code completion for a nested-name-specifier, where the code
236	// completion token follows the '::'.
237	Actions.CodeCompletion().CodeCompleteQualifiedId(
238	S: getCurScope(), SS, EnteringContext, IsUsingDeclaration: InUsingDeclaration,
239	BaseType: ObjectType.get(), PreferredType: SavedType.get(SS.getBeginLoc()));
240	// Include code completion token into the range of the scope otherwise
241	// when we try to annotate the scope tokens the dangling code completion
242	// token will cause assertion in
243	// Preprocessor::AnnotatePreviousCachedTokens.
244	SS.setEndLoc(Tok.getLocation());
245	return true;
246	}
247
248	// C++ [basic.lookup.classref]p5:
249	// If the qualified-id has the form
250	//
251	// ::class-name-or-namespace-name::...
252	//
253	// the class-name-or-namespace-name is looked up in global scope as a
254	// class-name or namespace-name.
255	//
256	// To implement this, we clear out the object type as soon as we've
257	// seen a leading '::' or part of a nested-name-specifier.
258	ObjectType = nullptr;
259	}
260
261	// nested-name-specifier:
262	// nested-name-specifier 'template'[opt] simple-template-id '::'
263
264	// Parse the optional 'template' keyword, then make sure we have
265	// 'identifier <' after it.
266	if (Tok.is(K: tok::kw_template)) {
267	// If we don't have a scope specifier or an object type, this isn't a
268	// nested-name-specifier, since they aren't allowed to start with
269	// 'template'.
270	if (!HasScopeSpecifier && !ObjectType)
271	break;
272
273	TentativeParsingAction TPA(*this);
274	SourceLocation TemplateKWLoc = ConsumeToken();
275
276	UnqualifiedId TemplateName;
277	if (Tok.is(K: tok::identifier)) {
278	// Consume the identifier.
279	TemplateName.setIdentifier(Id: Tok.getIdentifierInfo(), IdLoc: Tok.getLocation());
280	ConsumeToken();
281	} else if (Tok.is(K: tok::kw_operator)) {
282	// We don't need to actually parse the unqualified-id in this case,
283	// because a simple-template-id cannot start with 'operator', but
284	// go ahead and parse it anyway for consistency with the case where
285	// we already annotated the template-id.
286	if (ParseUnqualifiedIdOperator(SS, EnteringContext, ObjectType,
287	Result&: TemplateName)) {
288	TPA.Commit();
289	break;
290	}
291
292	if (TemplateName.getKind() != UnqualifiedIdKind::IK_OperatorFunctionId &&
293	TemplateName.getKind() != UnqualifiedIdKind::IK_LiteralOperatorId) {
294	Diag(TemplateName.getSourceRange().getBegin(),
295	diag::err_id_after_template_in_nested_name_spec)
296	<< TemplateName.getSourceRange();
297	TPA.Commit();
298	break;
299	}
300	} else {
301	TPA.Revert();
302	break;
303	}
304
305	// If the next token is not '<', we have a qualified-id that refers
306	// to a template name, such as T::template apply, but is not a
307	// template-id.
308	if (Tok.isNot(K: tok::less)) {
309	TPA.Revert();
310	break;
311	}
312
313	// Commit to parsing the template-id.
314	TPA.Commit();
315	TemplateTy Template;
316	TemplateNameKind TNK = Actions.ActOnTemplateName(
317	S: getCurScope(), SS, TemplateKWLoc, Name: TemplateName, ObjectType,
318	EnteringContext, Template, /*AllowInjectedClassName*/ true);
319	if (AnnotateTemplateIdToken(Template, TNK, SS, TemplateKWLoc,
320	TemplateName, AllowTypeAnnotation: false))
321	return true;
322
323	continue;
324	}
325
326	if (Tok.is(K: tok::annot_template_id) && NextToken().is(K: tok::coloncolon)) {
327	// We have
328	//
329	// template-id '::'
330	//
331	// So we need to check whether the template-id is a simple-template-id of
332	// the right kind (it should name a type or be dependent), and then
333	// convert it into a type within the nested-name-specifier.
334	TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(tok: Tok);
335	if (CheckForDestructor && GetLookAheadToken(N: 2).is(K: tok::tilde)) {
336	*MayBePseudoDestructor = true;
337	return false;
338	}
339
340	if (LastII)
341	*LastII = TemplateId->Name;
342
343	// Consume the template-id token.
344	ConsumeAnnotationToken();
345
346	assert(Tok.is(tok::coloncolon) && "NextToken() not working properly!");
347	SourceLocation CCLoc = ConsumeToken();
348
349	HasScopeSpecifier = true;
350
351	ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
352	TemplateId->NumArgs);
353
354	if (TemplateId->isInvalid() ||
355	Actions.ActOnCXXNestedNameSpecifier(S: getCurScope(),
356	SS,
357	TemplateKWLoc: TemplateId->TemplateKWLoc,
358	TemplateName: TemplateId->Template,
359	TemplateNameLoc: TemplateId->TemplateNameLoc,
360	LAngleLoc: TemplateId->LAngleLoc,
361	TemplateArgs: TemplateArgsPtr,
362	RAngleLoc: TemplateId->RAngleLoc,
363	CCLoc,
364	EnteringContext)) {
365	SourceLocation StartLoc
366	= SS.getBeginLoc().isValid()? SS.getBeginLoc()
367	: TemplateId->TemplateNameLoc;
368	SS.SetInvalid(SourceRange(StartLoc, CCLoc));
369	}
370
371	continue;
372	}
373
374	switch (Tok.getKind()) {
375	#define TRANSFORM_TYPE_TRAIT_DEF(_, Trait) case tok::kw___##Trait:
376	#include "clang/Basic/TransformTypeTraits.def"
377	if (!NextToken().is(K: tok::l_paren)) {
378	Tok.setKind(tok::identifier);
379	Diag(Tok, diag::ext_keyword_as_ident)
380	<< Tok.getIdentifierInfo()->getName() << 0;
381	continue;
382	}
383	[[fallthrough]];
384	default:
385	break;
386	}
387
388	// The rest of the nested-name-specifier possibilities start with
389	// tok::identifier.
390	if (Tok.isNot(K: tok::identifier))
391	break;
392
393	IdentifierInfo &II = *Tok.getIdentifierInfo();
394
395	// nested-name-specifier:
396	// type-name '::'
397	// namespace-name '::'
398	// nested-name-specifier identifier '::'
399	Token Next = NextToken();
400	Sema::NestedNameSpecInfo IdInfo(&II, Tok.getLocation(), Next.getLocation(),
401	ObjectType);
402
403	// If we get foo:bar, this is almost certainly a typo for foo::bar. Recover
404	// and emit a fixit hint for it.
405	if (Next.is(K: tok::colon) && !ColonIsSacred) {
406	if (Actions.IsInvalidUnlessNestedName(S: getCurScope(), SS, IdInfo,
407	EnteringContext) &&
408	// If the token after the colon isn't an identifier, it's still an
409	// error, but they probably meant something else strange so don't
410	// recover like this.
411	PP.LookAhead(N: 1).is(K: tok::identifier)) {
412	Diag(Next, diag::err_unexpected_colon_in_nested_name_spec)
413	<< FixItHint::CreateReplacement(Next.getLocation(), "::");
414	// Recover as if the user wrote '::'.
415	Next.setKind(tok::coloncolon);
416	}
417	}
418
419	if (Next.is(K: tok::coloncolon) && GetLookAheadToken(N: 2).is(K: tok::l_brace)) {
420	// It is invalid to have :: {, consume the scope qualifier and pretend
421	// like we never saw it.
422	Token Identifier = Tok; // Stash away the identifier.
423	ConsumeToken(); // Eat the identifier, current token is now '::'.
424	ConsumeToken();
425	Diag(getEndOfPreviousToken(), diag::err_expected) << tok::identifier;
426	UnconsumeToken(Consumed&: Identifier); // Stick the identifier back.
427	Next = NextToken(); // Point Next at the '{' token.
428	}
429
430	if (Next.is(K: tok::coloncolon)) {
431	if (CheckForDestructor && GetLookAheadToken(N: 2).is(K: tok::tilde)) {
432	*MayBePseudoDestructor = true;
433	return false;
434	}
435
436	if (ColonIsSacred) {
437	const Token &Next2 = GetLookAheadToken(N: 2);
438	if (Next2.is(K: tok::kw_private) || Next2.is(K: tok::kw_protected) ||
439	Next2.is(K: tok::kw_public) || Next2.is(K: tok::kw_virtual)) {
440	Diag(Next2, diag::err_unexpected_token_in_nested_name_spec)
441	<< Next2.getName()
442	<< FixItHint::CreateReplacement(Next.getLocation(), ":");
443	Token ColonColon;
444	PP.Lex(Result&: ColonColon);
445	ColonColon.setKind(tok::colon);
446	PP.EnterToken(Tok: ColonColon, /*IsReinject*/ true);
447	break;
448	}
449	}
450
451	if (LastII)
452	*LastII = &II;
453
454	// We have an identifier followed by a '::'. Lookup this name
455	// as the name in a nested-name-specifier.
456	Token Identifier = Tok;
457	SourceLocation IdLoc = ConsumeToken();
458	assert(Tok.isOneOf(tok::coloncolon, tok::colon) &&
459	"NextToken() not working properly!");
460	Token ColonColon = Tok;
461	SourceLocation CCLoc = ConsumeToken();
462
463	bool IsCorrectedToColon = false;
464	bool *CorrectionFlagPtr = ColonIsSacred ? &IsCorrectedToColon : nullptr;
465	if (Actions.ActOnCXXNestedNameSpecifier(
466	S: getCurScope(), IdInfo, EnteringContext, SS, IsCorrectedToColon: CorrectionFlagPtr,
467	OnlyNamespace)) {
468	// Identifier is not recognized as a nested name, but we can have
469	// mistyped '::' instead of ':'.
470	if (CorrectionFlagPtr && IsCorrectedToColon) {
471	ColonColon.setKind(tok::colon);
472	PP.EnterToken(Tok, /*IsReinject*/ true);
473	PP.EnterToken(Tok: ColonColon, /*IsReinject*/ true);
474	Tok = Identifier;
475	break;
476	}
477	SS.SetInvalid(SourceRange(IdLoc, CCLoc));
478	}
479	HasScopeSpecifier = true;
480	continue;
481	}
482
483	CheckForTemplateAndDigraph(Next, ObjectType, EnteringContext, II, SS);
484
485	// nested-name-specifier:
486	// type-name '<'
487	if (Next.is(K: tok::less)) {
488
489	TemplateTy Template;
490	UnqualifiedId TemplateName;
491	TemplateName.setIdentifier(Id: &II, IdLoc: Tok.getLocation());
492	bool MemberOfUnknownSpecialization;
493	if (TemplateNameKind TNK = Actions.isTemplateName(
494	S: getCurScope(), SS,
495	/*hasTemplateKeyword=*/false, Name: TemplateName, ObjectType,
496	EnteringContext, Template, MemberOfUnknownSpecialization,
497	Disambiguation)) {
498	// If lookup didn't find anything, we treat the name as a template-name
499	// anyway. C++20 requires this, and in prior language modes it improves
500	// error recovery. But before we commit to this, check that we actually
501	// have something that looks like a template-argument-list next.
502	if (!IsTypename && TNK == TNK_Undeclared_template &&
503	isTemplateArgumentList(TokensToSkip: 1) == TPResult::False)
504	break;
505
506	// We have found a template name, so annotate this token
507	// with a template-id annotation. We do not permit the
508	// template-id to be translated into a type annotation,
509	// because some clients (e.g., the parsing of class template
510	// specializations) still want to see the original template-id
511	// token, and it might not be a type at all (e.g. a concept name in a
512	// type-constraint).
513	ConsumeToken();
514	if (AnnotateTemplateIdToken(Template, TNK, SS, TemplateKWLoc: SourceLocation(),
515	TemplateName, AllowTypeAnnotation: false))
516	return true;
517	continue;
518	}
519
520	if (MemberOfUnknownSpecialization && !Disambiguation &&
521	(ObjectType || SS.isSet()) &&
522	(IsTypename || isTemplateArgumentList(TokensToSkip: 1) == TPResult::True)) {
523	// If we had errors before, ObjectType can be dependent even without any
524	// templates. Do not report missing template keyword in that case.
525	if (!ObjectHadErrors) {
526	// We have something like t::getAs<T>, where getAs is a
527	// member of an unknown specialization. However, this will only
528	// parse correctly as a template, so suggest the keyword 'template'
529	// before 'getAs' and treat this as a dependent template name.
530	unsigned DiagID = diag::err_missing_dependent_template_keyword;
531	if (getLangOpts().MicrosoftExt)
532	DiagID = diag::warn_missing_dependent_template_keyword;
533
534	Diag(Loc: Tok.getLocation(), DiagID)
535	<< II.getName()
536	<< FixItHint::CreateInsertion(InsertionLoc: Tok.getLocation(), Code: "template ");
537	}
538	ConsumeToken();
539
540	TemplateNameKind TNK = Actions.ActOnTemplateName(
541	S: getCurScope(), SS, /*TemplateKWLoc=*/SourceLocation(), Name: TemplateName,
542	ObjectType, EnteringContext, Template,
543	/*AllowInjectedClassName=*/true);
544	if (AnnotateTemplateIdToken(Template, TNK, SS, TemplateKWLoc: SourceLocation(),
545	TemplateName, AllowTypeAnnotation: false))
546	return true;
547
548	continue;
549	}
550	}
551
552	// We don't have any tokens that form the beginning of a
553	// nested-name-specifier, so we're done.
554	break;
555	}
556
557	// Even if we didn't see any pieces of a nested-name-specifier, we
558	// still check whether there is a tilde in this position, which
559	// indicates a potential pseudo-destructor.
560	if (CheckForDestructor && !HasScopeSpecifier && Tok.is(K: tok::tilde))
561	*MayBePseudoDestructor = true;
562
563	return false;
564	}
565
566	ExprResult Parser::tryParseCXXIdExpression(CXXScopeSpec &SS,
567	bool isAddressOfOperand,
568	Token &Replacement) {
569	ExprResult E;
570
571	// We may have already annotated this id-expression.
572	switch (Tok.getKind()) {
573	case tok::annot_non_type: {
574	NamedDecl *ND = getNonTypeAnnotation(Tok);
575	SourceLocation Loc = ConsumeAnnotationToken();
576	E = Actions.ActOnNameClassifiedAsNonType(S: getCurScope(), SS, Found: ND, NameLoc: Loc, NextToken: Tok);
577	break;
578	}
579
580	case tok::annot_non_type_dependent: {
581	IdentifierInfo *II = getIdentifierAnnotation(Tok);
582	SourceLocation Loc = ConsumeAnnotationToken();
583
584	// This is only the direct operand of an & operator if it is not
585	// followed by a postfix-expression suffix.
586	if (isAddressOfOperand && isPostfixExpressionSuffixStart())
587	isAddressOfOperand = false;
588
589	E = Actions.ActOnNameClassifiedAsDependentNonType(SS, Name: II, NameLoc: Loc,
590	IsAddressOfOperand: isAddressOfOperand);
591	break;
592	}
593
594	case tok::annot_non_type_undeclared: {
595	assert(SS.isEmpty() &&
596	"undeclared non-type annotation should be unqualified");
597	IdentifierInfo *II = getIdentifierAnnotation(Tok);
598	SourceLocation Loc = ConsumeAnnotationToken();
599	E = Actions.ActOnNameClassifiedAsUndeclaredNonType(Name: II, NameLoc: Loc);
600	break;
601	}
602
603	default:
604	SourceLocation TemplateKWLoc;
605	UnqualifiedId Name;
606	if (ParseUnqualifiedId(SS, /*ObjectType=*/nullptr,
607	/*ObjectHadErrors=*/false,
608	/*EnteringContext=*/false,
609	/*AllowDestructorName=*/false,
610	/*AllowConstructorName=*/false,
611	/*AllowDeductionGuide=*/false, TemplateKWLoc: &TemplateKWLoc, Result&: Name))
612	return ExprError();
613
614	// This is only the direct operand of an & operator if it is not
615	// followed by a postfix-expression suffix.
616	if (isAddressOfOperand && isPostfixExpressionSuffixStart())
617	isAddressOfOperand = false;
618
619	E = Actions.ActOnIdExpression(
620	S: getCurScope(), SS, TemplateKWLoc, Id&: Name, HasTrailingLParen: Tok.is(K: tok::l_paren),
621	IsAddressOfOperand: isAddressOfOperand, /*CCC=*/nullptr, /*IsInlineAsmIdentifier=*/false,
622	KeywordReplacement: &Replacement);
623	break;
624	}
625
626	// Might be a pack index expression!
627	E = tryParseCXXPackIndexingExpression(PackIdExpression: E);
628
629	if (!E.isInvalid() && !E.isUnset() && Tok.is(K: tok::less))
630	checkPotentialAngleBracket(PotentialTemplateName&: E);
631	return E;
632	}
633
634	ExprResult Parser::ParseCXXPackIndexingExpression(ExprResult PackIdExpression) {
635	assert(Tok.is(tok::ellipsis) && NextToken().is(tok::l_square) &&
636	"expected ...[");
637	SourceLocation EllipsisLoc = ConsumeToken();
638	BalancedDelimiterTracker T(*this, tok::l_square);
639	T.consumeOpen();
640	ExprResult IndexExpr = ParseConstantExpression();
641	if (T.consumeClose() || IndexExpr.isInvalid())
642	return ExprError();
643	return Actions.ActOnPackIndexingExpr(S: getCurScope(), PackExpression: PackIdExpression.get(),
644	EllipsisLoc, LSquareLoc: T.getOpenLocation(),
645	IndexExpr: IndexExpr.get(), RSquareLoc: T.getCloseLocation());
646	}
647
648	ExprResult
649	Parser::tryParseCXXPackIndexingExpression(ExprResult PackIdExpression) {
650	ExprResult E = PackIdExpression;
651	if (!PackIdExpression.isInvalid() && !PackIdExpression.isUnset() &&
652	Tok.is(K: tok::ellipsis) && NextToken().is(K: tok::l_square)) {
653	E = ParseCXXPackIndexingExpression(PackIdExpression: E);
654	}
655	return E;
656	}
657
658	ExprResult Parser::ParseCXXIdExpression(bool isAddressOfOperand) {
659	// qualified-id:
660	// '::'[opt] nested-name-specifier 'template'[opt] unqualified-id
661	// '::' unqualified-id
662	//
663	CXXScopeSpec SS;
664	ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/nullptr,
665	/*ObjectHasErrors=*/ObjectHadErrors: false,
666	/*EnteringContext=*/false);
667
668	Token Replacement;
669	ExprResult Result =
670	tryParseCXXIdExpression(SS, isAddressOfOperand, Replacement);
671	if (Result.isUnset()) {
672	// If the ExprResult is valid but null, then typo correction suggested a
673	// keyword replacement that needs to be reparsed.
674	UnconsumeToken(Consumed&: Replacement);
675	Result = tryParseCXXIdExpression(SS, isAddressOfOperand, Replacement);
676	}
677	assert(!Result.isUnset() && "Typo correction suggested a keyword replacement "
678	"for a previous keyword suggestion");
679	return Result;
680	}
681
682	ExprResult Parser::ParseLambdaExpression() {
683	// Parse lambda-introducer.
684	LambdaIntroducer Intro;
685	if (ParseLambdaIntroducer(Intro)) {
686	SkipUntil(T: tok::r_square, Flags: StopAtSemi);
687	SkipUntil(T: tok::l_brace, Flags: StopAtSemi);
688	SkipUntil(T: tok::r_brace, Flags: StopAtSemi);
689	return ExprError();
690	}
691
692	return ParseLambdaExpressionAfterIntroducer(Intro);
693	}
694
695	ExprResult Parser::TryParseLambdaExpression() {
696	assert(getLangOpts().CPlusPlus && Tok.is(tok::l_square) &&
697	"Not at the start of a possible lambda expression.");
698
699	const Token Next = NextToken();
700	if (Next.is(K: tok::eof)) // Nothing else to lookup here...
701	return ExprEmpty();
702
703	const Token After = GetLookAheadToken(N: 2);
704	// If lookahead indicates this is a lambda...
705	if (Next.is(K: tok::r_square) || // []
706	Next.is(K: tok::equal) || // [=
707	(Next.is(K: tok::amp) && // [&] or [&,
708	After.isOneOf(K1: tok::r_square, K2: tok::comma)) ||
709	(Next.is(K: tok::identifier) && // [identifier]
710	After.is(K: tok::r_square)) ||
711	Next.is(K: tok::ellipsis)) { // [...
712	return ParseLambdaExpression();
713	}
714
715	// If lookahead indicates an ObjC message send...
716	// [identifier identifier
717	if (Next.is(K: tok::identifier) && After.is(K: tok::identifier))
718	return ExprEmpty();
719
720	// Here, we're stuck: lambda introducers and Objective-C message sends are
721	// unambiguous, but it requires arbitrary lookhead. [a,b,c,d,e,f,g] is a
722	// lambda, and [a,b,c,d,e,f,g h] is a Objective-C message send. Instead of
723	// writing two routines to parse a lambda introducer, just try to parse
724	// a lambda introducer first, and fall back if that fails.
725	LambdaIntroducer Intro;
726	{
727	TentativeParsingAction TPA(*this);
728	LambdaIntroducerTentativeParse Tentative;
729	if (ParseLambdaIntroducer(Intro, Tentative: &Tentative)) {
730	TPA.Commit();
731	return ExprError();
732	}
733
734	switch (Tentative) {
735	case LambdaIntroducerTentativeParse::Success:
736	TPA.Commit();
737	break;
738
739	case LambdaIntroducerTentativeParse::Incomplete:
740	// Didn't fully parse the lambda-introducer, try again with a
741	// non-tentative parse.
742	TPA.Revert();
743	Intro = LambdaIntroducer();
744	if (ParseLambdaIntroducer(Intro))
745	return ExprError();
746	break;
747
748	case LambdaIntroducerTentativeParse::MessageSend:
749	case LambdaIntroducerTentativeParse::Invalid:
750	// Not a lambda-introducer, might be a message send.
751	TPA.Revert();
752	return ExprEmpty();
753	}
754	}
755
756	return ParseLambdaExpressionAfterIntroducer(Intro);
757	}
758
759	bool Parser::ParseLambdaIntroducer(LambdaIntroducer &Intro,
760	LambdaIntroducerTentativeParse *Tentative) {
761	if (Tentative)
762	*Tentative = LambdaIntroducerTentativeParse::Success;
763
764	assert(Tok.is(tok::l_square) && "Lambda expressions begin with '['.");
765	BalancedDelimiterTracker T(*this, tok::l_square);
766	T.consumeOpen();
767
768	Intro.Range.setBegin(T.getOpenLocation());
769
770	bool First = true;
771
772	// Produce a diagnostic if we're not tentatively parsing; otherwise track
773	// that our parse has failed.
774	auto Invalid = [&](llvm::function_ref<void()> Action) {
775	if (Tentative) {
776	*Tentative = LambdaIntroducerTentativeParse::Invalid;
777	return false;
778	}
779	Action();
780	return true;
781	};
782
783	// Perform some irreversible action if this is a non-tentative parse;
784	// otherwise note that our actions were incomplete.
785	auto NonTentativeAction = [&](llvm::function_ref<void()> Action) {
786	if (Tentative)
787	*Tentative = LambdaIntroducerTentativeParse::Incomplete;
788	else
789	Action();
790	};
791
792	// Parse capture-default.
793	if (Tok.is(K: tok::amp) &&
794	(NextToken().is(K: tok::comma) || NextToken().is(K: tok::r_square))) {
795	Intro.Default = LCD_ByRef;
796	Intro.DefaultLoc = ConsumeToken();
797	First = false;
798	if (!Tok.getIdentifierInfo()) {
799	// This can only be a lambda; no need for tentative parsing any more.
800	// '[[and]]' can still be an attribute, though.
801	Tentative = nullptr;
802	}
803	} else if (Tok.is(K: tok::equal)) {
804	Intro.Default = LCD_ByCopy;
805	Intro.DefaultLoc = ConsumeToken();
806	First = false;
807	Tentative = nullptr;
808	}
809
810	while (Tok.isNot(K: tok::r_square)) {
811	if (!First) {
812	if (Tok.isNot(K: tok::comma)) {
813	// Provide a completion for a lambda introducer here. Except
814	// in Objective-C, where this is Almost Surely meant to be a message
815	// send. In that case, fail here and let the ObjC message
816	// expression parser perform the completion.
817	if (Tok.is(K: tok::code_completion) &&
818	!(getLangOpts().ObjC && Tentative)) {
819	cutOffParsing();
820	Actions.CodeCompletion().CodeCompleteLambdaIntroducer(
821	S: getCurScope(), Intro,
822	/*AfterAmpersand=*/false);
823	break;
824	}
825
826	return Invalid([&] {
827	Diag(Tok.getLocation(), diag::err_expected_comma_or_rsquare);
828	});
829	}
830	ConsumeToken();
831	}
832
833	if (Tok.is(K: tok::code_completion)) {
834	cutOffParsing();
835	// If we're in Objective-C++ and we have a bare '[', then this is more
836	// likely to be a message receiver.
837	if (getLangOpts().ObjC && Tentative && First)
838	Actions.CodeCompletion().CodeCompleteObjCMessageReceiver(S: getCurScope());
839	else
840	Actions.CodeCompletion().CodeCompleteLambdaIntroducer(
841	S: getCurScope(), Intro,
842	/*AfterAmpersand=*/false);
843	break;
844	}
845
846	First = false;
847
848	// Parse capture.
849	LambdaCaptureKind Kind = LCK_ByCopy;
850	LambdaCaptureInitKind InitKind = LambdaCaptureInitKind::NoInit;
851	SourceLocation Loc;
852	IdentifierInfo *Id = nullptr;
853	SourceLocation EllipsisLocs[4];
854	ExprResult Init;
855	SourceLocation LocStart = Tok.getLocation();
856
857	if (Tok.is(K: tok::star)) {
858	Loc = ConsumeToken();
859	if (Tok.is(K: tok::kw_this)) {
860	ConsumeToken();
861	Kind = LCK_StarThis;
862	} else {
863	return Invalid([&] {
864	Diag(Tok.getLocation(), diag::err_expected_star_this_capture);
865	});
866	}
867	} else if (Tok.is(K: tok::kw_this)) {
868	Kind = LCK_This;
869	Loc = ConsumeToken();
870	} else if (Tok.isOneOf(K1: tok::amp, K2: tok::equal) &&
871	NextToken().isOneOf(K1: tok::comma, K2: tok::r_square) &&
872	Intro.Default == LCD_None) {
873	// We have a lone "&" or "=" which is either a misplaced capture-default
874	// or the start of a capture (in the "&" case) with the rest of the
875	// capture missing. Both are an error but a misplaced capture-default
876	// is more likely if we don't already have a capture default.
877	return Invalid(
878	[&] { Diag(Tok.getLocation(), diag::err_capture_default_first); });
879	} else {
880	TryConsumeToken(Expected: tok::ellipsis, Loc&: EllipsisLocs[0]);
881
882	if (Tok.is(K: tok::amp)) {
883	Kind = LCK_ByRef;
884	ConsumeToken();
885
886	if (Tok.is(K: tok::code_completion)) {
887	cutOffParsing();
888	Actions.CodeCompletion().CodeCompleteLambdaIntroducer(
889	S: getCurScope(), Intro,
890	/*AfterAmpersand=*/true);
891	break;
892	}
893	}
894
895	TryConsumeToken(Expected: tok::ellipsis, Loc&: EllipsisLocs[1]);
896
897	if (Tok.is(K: tok::identifier)) {
898	Id = Tok.getIdentifierInfo();
899	Loc = ConsumeToken();
900	} else if (Tok.is(K: tok::kw_this)) {
901	return Invalid([&] {
902	// FIXME: Suggest a fixit here.
903	Diag(Tok.getLocation(), diag::err_this_captured_by_reference);
904	});
905	} else {
906	return Invalid([&] {
907	Diag(Tok.getLocation(), diag::err_expected_capture);
908	});
909	}
910
911	TryConsumeToken(Expected: tok::ellipsis, Loc&: EllipsisLocs[2]);
912
913	if (Tok.is(K: tok::l_paren)) {
914	BalancedDelimiterTracker Parens(*this, tok::l_paren);
915	Parens.consumeOpen();
916
917	InitKind = LambdaCaptureInitKind::DirectInit;
918
919	ExprVector Exprs;
920	if (Tentative) {
921	Parens.skipToEnd();
922	*Tentative = LambdaIntroducerTentativeParse::Incomplete;
923	} else if (ParseExpressionList(Exprs)) {
924	Parens.skipToEnd();
925	Init = ExprError();
926	} else {
927	Parens.consumeClose();
928	Init = Actions.ActOnParenListExpr(L: Parens.getOpenLocation(),
929	R: Parens.getCloseLocation(),
930	Val: Exprs);
931	}
932	} else if (Tok.isOneOf(K1: tok::l_brace, K2: tok::equal)) {
933	// Each lambda init-capture forms its own full expression, which clears
934	// Actions.MaybeODRUseExprs. So create an expression evaluation context
935	// to save the necessary state, and restore it later.
936	EnterExpressionEvaluationContext EC(
937	Actions, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
938
939	if (TryConsumeToken(Expected: tok::equal))
940	InitKind = LambdaCaptureInitKind::CopyInit;
941	else
942	InitKind = LambdaCaptureInitKind::ListInit;
943
944	if (!Tentative) {
945	Init = ParseInitializer();
946	} else if (Tok.is(K: tok::l_brace)) {
947	BalancedDelimiterTracker Braces(*this, tok::l_brace);
948	Braces.consumeOpen();
949	Braces.skipToEnd();
950	*Tentative = LambdaIntroducerTentativeParse::Incomplete;
951	} else {
952	// We're disambiguating this:
953	//
954	// [..., x = expr
955	//
956	// We need to find the end of the following expression in order to
957	// determine whether this is an Obj-C message send's receiver, a
958	// C99 designator, or a lambda init-capture.
959	//
960	// Parse the expression to find where it ends, and annotate it back
961	// onto the tokens. We would have parsed this expression the same way
962	// in either case: both the RHS of an init-capture and the RHS of an
963	// assignment expression are parsed as an initializer-clause, and in
964	// neither case can anything be added to the scope between the '[' and
965	// here.
966	//
967	// FIXME: This is horrible. Adding a mechanism to skip an expression
968	// would be much cleaner.
969	// FIXME: If there is a ',' before the next ']' or ':', we can skip to
970	// that instead. (And if we see a ':' with no matching '?', we can
971	// classify this as an Obj-C message send.)
972	SourceLocation StartLoc = Tok.getLocation();
973	InMessageExpressionRAIIObject MaybeInMessageExpression(*this, true);
974	Init = ParseInitializer();
975	if (!Init.isInvalid())
976	Init = Actions.CorrectDelayedTyposInExpr(E: Init.get());
977
978	if (Tok.getLocation() != StartLoc) {
979	// Back out the lexing of the token after the initializer.
980	PP.RevertCachedTokens(N: 1);
981
982	// Replace the consumed tokens with an appropriate annotation.
983	Tok.setLocation(StartLoc);
984	Tok.setKind(tok::annot_primary_expr);
985	setExprAnnotation(Tok, ER: Init);
986	Tok.setAnnotationEndLoc(PP.getLastCachedTokenLocation());
987	PP.AnnotateCachedTokens(Tok);
988
989	// Consume the annotated initializer.
990	ConsumeAnnotationToken();
991	}
992	}
993	}
994
995	TryConsumeToken(Expected: tok::ellipsis, Loc&: EllipsisLocs[3]);
996	}
997
998	// Check if this is a message send before we act on a possible init-capture.
999	if (Tentative && Tok.is(K: tok::identifier) &&
1000	NextToken().isOneOf(K1: tok::colon, K2: tok::r_square)) {
1001	// This can only be a message send. We're done with disambiguation.
1002	*Tentative = LambdaIntroducerTentativeParse::MessageSend;
1003	return false;
1004	}
1005
1006	// Ensure that any ellipsis was in the right place.
1007	SourceLocation EllipsisLoc;
1008	if (llvm::any_of(Range&: EllipsisLocs,
1009	P: [](SourceLocation Loc) { return Loc.isValid(); })) {
1010	// The '...' should appear before the identifier in an init-capture, and
1011	// after the identifier otherwise.
1012	bool InitCapture = InitKind != LambdaCaptureInitKind::NoInit;
1013	SourceLocation *ExpectedEllipsisLoc =
1014	!InitCapture ? &EllipsisLocs[2] :
1015	Kind == LCK_ByRef ? &EllipsisLocs[1] :
1016	&EllipsisLocs[0];
1017	EllipsisLoc = *ExpectedEllipsisLoc;
1018
1019	unsigned DiagID = 0;
1020	if (EllipsisLoc.isInvalid()) {
1021	DiagID = diag::err_lambda_capture_misplaced_ellipsis;
1022	for (SourceLocation Loc : EllipsisLocs) {
1023	if (Loc.isValid())
1024	EllipsisLoc = Loc;
1025	}
1026	} else {
1027	unsigned NumEllipses = std::accumulate(
1028	first: std::begin(arr&: EllipsisLocs), last: std::end(arr&: EllipsisLocs), init: 0,
1029	binary_op: [](int N, SourceLocation Loc) { return N + Loc.isValid(); });
1030	if (NumEllipses > 1)
1031	DiagID = diag::err_lambda_capture_multiple_ellipses;
1032	}
1033	if (DiagID) {
1034	NonTentativeAction([&] {
1035	// Point the diagnostic at the first misplaced ellipsis.
1036	SourceLocation DiagLoc;
1037	for (SourceLocation &Loc : EllipsisLocs) {
1038	if (&Loc != ExpectedEllipsisLoc && Loc.isValid()) {
1039	DiagLoc = Loc;
1040	break;
1041	}
1042	}
1043	assert(DiagLoc.isValid() && "no location for diagnostic");
1044
1045	// Issue the diagnostic and produce fixits showing where the ellipsis
1046	// should have been written.
1047	auto &&D = Diag(Loc: DiagLoc, DiagID);
1048	if (DiagID == diag::err_lambda_capture_misplaced_ellipsis) {
1049	SourceLocation ExpectedLoc =
1050	InitCapture ? Loc
1051	: Lexer::getLocForEndOfToken(
1052	Loc, Offset: 0, SM: PP.getSourceManager(), LangOpts: getLangOpts());
1053	D << InitCapture << FixItHint::CreateInsertion(InsertionLoc: ExpectedLoc, Code: "...");
1054	}
1055	for (SourceLocation &Loc : EllipsisLocs) {
1056	if (&Loc != ExpectedEllipsisLoc && Loc.isValid())
1057	D << FixItHint::CreateRemoval(RemoveRange: Loc);
1058	}
1059	});
1060	}
1061	}
1062
1063	// Process the init-capture initializers now rather than delaying until we
1064	// form the lambda-expression so that they can be handled in the context
1065	// enclosing the lambda-expression, rather than in the context of the
1066	// lambda-expression itself.
1067	ParsedType InitCaptureType;
1068	if (Init.isUsable())
1069	Init = Actions.CorrectDelayedTyposInExpr(E: Init.get());
1070	if (Init.isUsable()) {
1071	NonTentativeAction([&] {
1072	// Get the pointer and store it in an lvalue, so we can use it as an
1073	// out argument.
1074	Expr *InitExpr = Init.get();
1075	// This performs any lvalue-to-rvalue conversions if necessary, which
1076	// can affect what gets captured in the containing decl-context.
1077	InitCaptureType = Actions.actOnLambdaInitCaptureInitialization(
1078	Loc, ByRef: Kind == LCK_ByRef, EllipsisLoc, Id, InitKind, Init&: InitExpr);
1079	Init = InitExpr;
1080	});
1081	}
1082
1083	SourceLocation LocEnd = PrevTokLocation;
1084
1085	Intro.addCapture(Kind, Loc, Id, EllipsisLoc, InitKind, Init,
1086	InitCaptureType, ExplicitRange: SourceRange(LocStart, LocEnd));
1087	}
1088
1089	T.consumeClose();
1090	Intro.Range.setEnd(T.getCloseLocation());
1091	return false;
1092	}
1093
1094	static void tryConsumeLambdaSpecifierToken(Parser &P,
1095	SourceLocation &MutableLoc,
1096	SourceLocation &StaticLoc,
1097	SourceLocation &ConstexprLoc,
1098	SourceLocation &ConstevalLoc,
1099	SourceLocation &DeclEndLoc) {
1100	assert(MutableLoc.isInvalid());
1101	assert(StaticLoc.isInvalid());
1102	assert(ConstexprLoc.isInvalid());
1103	assert(ConstevalLoc.isInvalid());
1104	// Consume constexpr-opt mutable-opt in any sequence, and set the DeclEndLoc
1105	// to the final of those locations. Emit an error if we have multiple
1106	// copies of those keywords and recover.
1107
1108	auto ConsumeLocation = [&P, &DeclEndLoc](SourceLocation &SpecifierLoc,
1109	int DiagIndex) {
1110	if (SpecifierLoc.isValid()) {
1111	P.Diag(P.getCurToken().getLocation(),
1112	diag::err_lambda_decl_specifier_repeated)
1113	<< DiagIndex
1114	<< FixItHint::CreateRemoval(P.getCurToken().getLocation());
1115	}
1116	SpecifierLoc = P.ConsumeToken();
1117	DeclEndLoc = SpecifierLoc;
1118	};
1119
1120	while (true) {
1121	switch (P.getCurToken().getKind()) {
1122	case tok::kw_mutable:
1123	ConsumeLocation(MutableLoc, 0);
1124	break;
1125	case tok::kw_static:
1126	ConsumeLocation(StaticLoc, 1);
1127	break;
1128	case tok::kw_constexpr:
1129	ConsumeLocation(ConstexprLoc, 2);
1130	break;
1131	case tok::kw_consteval:
1132	ConsumeLocation(ConstevalLoc, 3);
1133	break;
1134	default:
1135	return;
1136	}
1137	}
1138	}
1139
1140	static void addStaticToLambdaDeclSpecifier(Parser &P, SourceLocation StaticLoc,
1141	DeclSpec &DS) {
1142	if (StaticLoc.isValid()) {
1143	P.Diag(StaticLoc, !P.getLangOpts().CPlusPlus23
1144	? diag::err_static_lambda
1145	: diag::warn_cxx20_compat_static_lambda);
1146	const char *PrevSpec = nullptr;
1147	unsigned DiagID = 0;
1148	DS.SetStorageClassSpec(S&: P.getActions(), SC: DeclSpec::SCS_static, Loc: StaticLoc,
1149	PrevSpec, DiagID,
1150	Policy: P.getActions().getASTContext().getPrintingPolicy());
1151	assert(PrevSpec == nullptr && DiagID == 0 &&
1152	"Static cannot have been set previously!");
1153	}
1154	}
1155
1156	static void
1157	addConstexprToLambdaDeclSpecifier(Parser &P, SourceLocation ConstexprLoc,
1158	DeclSpec &DS) {
1159	if (ConstexprLoc.isValid()) {
1160	P.Diag(ConstexprLoc, !P.getLangOpts().CPlusPlus17
1161	? diag::ext_constexpr_on_lambda_cxx17
1162	: diag::warn_cxx14_compat_constexpr_on_lambda);
1163	const char *PrevSpec = nullptr;
1164	unsigned DiagID = 0;
1165	DS.SetConstexprSpec(ConstexprKind: ConstexprSpecKind::Constexpr, Loc: ConstexprLoc, PrevSpec,
1166	DiagID);
1167	assert(PrevSpec == nullptr && DiagID == 0 &&
1168	"Constexpr cannot have been set previously!");
1169	}
1170	}
1171
1172	static void addConstevalToLambdaDeclSpecifier(Parser &P,
1173	SourceLocation ConstevalLoc,
1174	DeclSpec &DS) {
1175	if (ConstevalLoc.isValid()) {
1176	P.Diag(ConstevalLoc, diag::warn_cxx20_compat_consteval);
1177	const char *PrevSpec = nullptr;
1178	unsigned DiagID = 0;
1179	DS.SetConstexprSpec(ConstexprKind: ConstexprSpecKind::Consteval, Loc: ConstevalLoc, PrevSpec,
1180	DiagID);
1181	if (DiagID != 0)
1182	P.Diag(Loc: ConstevalLoc, DiagID) << PrevSpec;
1183	}
1184	}
1185
1186	static void DiagnoseStaticSpecifierRestrictions(Parser &P,
1187	SourceLocation StaticLoc,
1188	SourceLocation MutableLoc,
1189	const LambdaIntroducer &Intro) {
1190	if (StaticLoc.isInvalid())
1191	return;
1192
1193	// [expr.prim.lambda.general] p4
1194	// The lambda-specifier-seq shall not contain both mutable and static.
1195	// If the lambda-specifier-seq contains static, there shall be no
1196	// lambda-capture.
1197	if (MutableLoc.isValid())
1198	P.Diag(StaticLoc, diag::err_static_mutable_lambda);
1199	if (Intro.hasLambdaCapture()) {
1200	P.Diag(StaticLoc, diag::err_static_lambda_captures);
1201	}
1202	}
1203
1204	ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
1205	LambdaIntroducer &Intro) {
1206	SourceLocation LambdaBeginLoc = Intro.Range.getBegin();
1207	if (getLangOpts().HLSL)
1208	Diag(LambdaBeginLoc, diag::ext_hlsl_lambda) << /*HLSL*/ 1;
1209	else
1210	Diag(LambdaBeginLoc, getLangOpts().CPlusPlus11
1211	? diag::warn_cxx98_compat_lambda
1212	: diag::ext_lambda)
1213	<< /*C++*/ 0;
1214
1215	PrettyStackTraceLoc CrashInfo(PP.getSourceManager(), LambdaBeginLoc,
1216	"lambda expression parsing");
1217
1218	// Parse lambda-declarator[opt].
1219	DeclSpec DS(AttrFactory);
1220	Declarator D(DS, ParsedAttributesView::none(), DeclaratorContext::LambdaExpr);
1221	TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
1222
1223	ParseScope LambdaScope(this, Scope::LambdaScope | Scope::DeclScope |
1224	Scope::FunctionDeclarationScope |
1225	Scope::FunctionPrototypeScope);
1226
1227	Actions.PushLambdaScope();
1228	Actions.ActOnLambdaExpressionAfterIntroducer(Intro, CurContext: getCurScope());
1229
1230	ParsedAttributes Attributes(AttrFactory);
1231	if (getLangOpts().CUDA) {
1232	// In CUDA code, GNU attributes are allowed to appear immediately after the
1233	// "[...]", even if there is no "(...)" before the lambda body.
1234	//
1235	// Note that we support __noinline__ as a keyword in this mode and thus
1236	// it has to be separately handled.
1237	while (true) {
1238	if (Tok.is(K: tok::kw___noinline__)) {
1239	IdentifierInfo *AttrName = Tok.getIdentifierInfo();
1240	SourceLocation AttrNameLoc = ConsumeToken();
1241	Attributes.addNew(attrName: AttrName, attrRange: AttrNameLoc, /*ScopeName=*/scopeName: nullptr,
1242	scopeLoc: AttrNameLoc, /*ArgsUnion=*/args: nullptr,
1243	/*numArgs=*/0, form: tok::kw___noinline__);
1244	} else if (Tok.is(K: tok::kw___attribute))
1245	ParseGNUAttributes(Attrs&: Attributes, /*LatePArsedAttrList=*/LateAttrs: nullptr, D: &D);
1246	else
1247	break;
1248	}
1249
1250	D.takeAttributes(attrs&: Attributes);
1251	}
1252
1253	MultiParseScope TemplateParamScope(*this);
1254	if (Tok.is(K: tok::less)) {
1255	Diag(Tok, getLangOpts().CPlusPlus20
1256	? diag::warn_cxx17_compat_lambda_template_parameter_list
1257	: diag::ext_lambda_template_parameter_list);
1258
1259	SmallVector<NamedDecl*, 4> TemplateParams;
1260	SourceLocation LAngleLoc, RAngleLoc;
1261	if (ParseTemplateParameters(TemplateScopes&: TemplateParamScope,
1262	Depth: CurTemplateDepthTracker.getDepth(),
1263	TemplateParams, LAngleLoc, RAngleLoc)) {
1264	Actions.ActOnLambdaError(StartLoc: LambdaBeginLoc, CurScope: getCurScope());
1265	return ExprError();
1266	}
1267
1268	if (TemplateParams.empty()) {
1269	Diag(RAngleLoc,
1270	diag::err_lambda_template_parameter_list_empty);
1271	} else {
1272	// We increase the template depth before recursing into a requires-clause.
1273	//
1274	// This depth is used for setting up a LambdaScopeInfo (in
1275	// Sema::RecordParsingTemplateParameterDepth), which is used later when
1276	// inventing template parameters in InventTemplateParameter.
1277	//
1278	// This way, abbreviated generic lambdas could have different template
1279	// depths, avoiding substitution into the wrong template parameters during
1280	// constraint satisfaction check.
1281	++CurTemplateDepthTracker;
1282	ExprResult RequiresClause;
1283	if (TryConsumeToken(Expected: tok::kw_requires)) {
1284	RequiresClause =
1285	Actions.ActOnRequiresClause(ConstraintExpr: ParseConstraintLogicalOrExpression(
1286	/*IsTrailingRequiresClause=*/false));
1287	if (RequiresClause.isInvalid())
1288	SkipUntil(Toks: {tok::l_brace, tok::l_paren}, Flags: StopAtSemi | StopBeforeMatch);
1289	}
1290
1291	Actions.ActOnLambdaExplicitTemplateParameterList(
1292	Intro, LAngleLoc, TParams: TemplateParams, RAngleLoc, RequiresClause);
1293	}
1294	}
1295
1296	// Implement WG21 P2173, which allows attributes immediately before the
1297	// lambda declarator and applies them to the corresponding function operator
1298	// or operator template declaration. We accept this as a conforming extension
1299	// in all language modes that support lambdas.
1300	if (isCXX11AttributeSpecifier() !=
1301	CXX11AttributeKind::NotAttributeSpecifier) {
1302	Diag(Tok, getLangOpts().CPlusPlus23
1303	? diag::warn_cxx20_compat_decl_attrs_on_lambda
1304	: diag::ext_decl_attrs_on_lambda)
1305	<< Tok.getIdentifierInfo() << Tok.isRegularKeywordAttribute();
1306	MaybeParseCXX11Attributes(D);
1307	}
1308
1309	TypeResult TrailingReturnType;
1310	SourceLocation TrailingReturnTypeLoc;
1311	SourceLocation LParenLoc, RParenLoc;
1312	SourceLocation DeclEndLoc;
1313	bool HasParentheses = false;
1314	bool HasSpecifiers = false;
1315	SourceLocation MutableLoc;
1316
1317	ParseScope Prototype(this, Scope::FunctionPrototypeScope |
1318	Scope::FunctionDeclarationScope |
1319	Scope::DeclScope);
1320
1321	// Parse parameter-declaration-clause.
1322	SmallVector<DeclaratorChunk::ParamInfo, 16> ParamInfo;
1323	SourceLocation EllipsisLoc;
1324
1325	if (Tok.is(K: tok::l_paren)) {
1326	BalancedDelimiterTracker T(*this, tok::l_paren);
1327	T.consumeOpen();
1328	LParenLoc = T.getOpenLocation();
1329
1330	if (Tok.isNot(K: tok::r_paren)) {
1331	Actions.RecordParsingTemplateParameterDepth(
1332	Depth: CurTemplateDepthTracker.getOriginalDepth());
1333
1334	ParseParameterDeclarationClause(D, attrs&: Attributes, ParamInfo, EllipsisLoc);
1335	// For a generic lambda, each 'auto' within the parameter declaration
1336	// clause creates a template type parameter, so increment the depth.
1337	// If we've parsed any explicit template parameters, then the depth will
1338	// have already been incremented. So we make sure that at most a single
1339	// depth level is added.
1340	if (Actions.getCurGenericLambda())
1341	CurTemplateDepthTracker.setAddedDepth(1);
1342	}
1343
1344	T.consumeClose();
1345	DeclEndLoc = RParenLoc = T.getCloseLocation();
1346	HasParentheses = true;
1347	}
1348
1349	HasSpecifiers =
1350	Tok.isOneOf(K1: tok::kw_mutable, Ks: tok::arrow, Ks: tok::kw___attribute,
1351	Ks: tok::kw_constexpr, Ks: tok::kw_consteval, Ks: tok::kw_static,
1352	Ks: tok::kw___private, Ks: tok::kw___global, Ks: tok::kw___local,
1353	Ks: tok::kw___constant, Ks: tok::kw___generic, Ks: tok::kw_groupshared,
1354	Ks: tok::kw_requires, Ks: tok::kw_noexcept) ||
1355	Tok.isRegularKeywordAttribute() ||
1356	(Tok.is(K: tok::l_square) && NextToken().is(K: tok::l_square));
1357
1358	if (HasSpecifiers && !HasParentheses && !getLangOpts().CPlusPlus23) {
1359	// It's common to forget that one needs '()' before 'mutable', an
1360	// attribute specifier, the result type, or the requires clause. Deal with
1361	// this.
1362	Diag(Tok, diag::ext_lambda_missing_parens)
1363	<< FixItHint::CreateInsertion(Tok.getLocation(), "() ");
1364	}
1365
1366	if (HasParentheses || HasSpecifiers) {
1367	// GNU-style attributes must be parsed before the mutable specifier to
1368	// be compatible with GCC. MSVC-style attributes must be parsed before
1369	// the mutable specifier to be compatible with MSVC.
1370	MaybeParseAttributes(WhichAttrKinds: PAKM_GNU | PAKM_Declspec, Attrs&: Attributes);
1371	// Parse mutable-opt and/or constexpr-opt or consteval-opt, and update
1372	// the DeclEndLoc.
1373	SourceLocation ConstexprLoc;
1374	SourceLocation ConstevalLoc;
1375	SourceLocation StaticLoc;
1376
1377	tryConsumeLambdaSpecifierToken(P&: *this, MutableLoc, StaticLoc, ConstexprLoc,
1378	ConstevalLoc, DeclEndLoc);
1379
1380	DiagnoseStaticSpecifierRestrictions(P&: *this, StaticLoc, MutableLoc, Intro);
1381
1382	addStaticToLambdaDeclSpecifier(P&: *this, StaticLoc, DS);
1383	addConstexprToLambdaDeclSpecifier(P&: *this, ConstexprLoc, DS);
1384	addConstevalToLambdaDeclSpecifier(P&: *this, ConstevalLoc, DS);
1385	}
1386
1387	Actions.ActOnLambdaClosureParameters(LambdaScope: getCurScope(), ParamInfo);
1388
1389	if (!HasParentheses)
1390	Actions.ActOnLambdaClosureQualifiers(Intro, MutableLoc);
1391
1392	if (HasSpecifiers || HasParentheses) {
1393	// Parse exception-specification[opt].
1394	ExceptionSpecificationType ESpecType = EST_None;
1395	SourceRange ESpecRange;
1396	SmallVector<ParsedType, 2> DynamicExceptions;
1397	SmallVector<SourceRange, 2> DynamicExceptionRanges;
1398	ExprResult NoexceptExpr;
1399	CachedTokens *ExceptionSpecTokens;
1400
1401	ESpecType = tryParseExceptionSpecification(
1402	/*Delayed=*/false, SpecificationRange&: ESpecRange, DynamicExceptions,
1403	DynamicExceptionRanges, NoexceptExpr, ExceptionSpecTokens);
1404
1405	if (ESpecType != EST_None)
1406	DeclEndLoc = ESpecRange.getEnd();
1407
1408	// Parse attribute-specifier[opt].
1409	if (MaybeParseCXX11Attributes(Attrs&: Attributes))
1410	DeclEndLoc = Attributes.Range.getEnd();
1411
1412	// Parse OpenCL addr space attribute.
1413	if (Tok.isOneOf(K1: tok::kw___private, Ks: tok::kw___global, Ks: tok::kw___local,
1414	Ks: tok::kw___constant, Ks: tok::kw___generic)) {
1415	ParseOpenCLQualifiers(Attrs&: DS.getAttributes());
1416	ConsumeToken();
1417	}
1418
1419	SourceLocation FunLocalRangeEnd = DeclEndLoc;
1420
1421	// Parse trailing-return-type[opt].
1422	if (Tok.is(K: tok::arrow)) {
1423	FunLocalRangeEnd = Tok.getLocation();
1424	SourceRange Range;
1425	TrailingReturnType =
1426	ParseTrailingReturnType(Range, /*MayBeFollowedByDirectInit=*/false);
1427	TrailingReturnTypeLoc = Range.getBegin();
1428	if (Range.getEnd().isValid())
1429	DeclEndLoc = Range.getEnd();
1430	}
1431
1432	SourceLocation NoLoc;
1433	D.AddTypeInfo(TI: DeclaratorChunk::getFunction(
1434	/*HasProto=*/true,
1435	/*IsAmbiguous=*/false, LParenLoc, Params: ParamInfo.data(),
1436	NumParams: ParamInfo.size(), EllipsisLoc, RParenLoc,
1437	/*RefQualifierIsLvalueRef=*/true,
1438	/*RefQualifierLoc=*/NoLoc, MutableLoc, ESpecType,
1439	ESpecRange, Exceptions: DynamicExceptions.data(),
1440	ExceptionRanges: DynamicExceptionRanges.data(), NumExceptions: DynamicExceptions.size(),
1441	NoexceptExpr: NoexceptExpr.isUsable() ? NoexceptExpr.get() : nullptr,
1442	/*ExceptionSpecTokens*/ nullptr,
1443	/*DeclsInPrototype=*/{}, LocalRangeBegin: LParenLoc, LocalRangeEnd: FunLocalRangeEnd, TheDeclarator&: D,
1444	TrailingReturnType, TrailingReturnTypeLoc, MethodQualifiers: &DS),
1445	attrs: std::move(Attributes), EndLoc: DeclEndLoc);
1446
1447	// We have called ActOnLambdaClosureQualifiers for parentheses-less cases
1448	// above.
1449	if (HasParentheses)
1450	Actions.ActOnLambdaClosureQualifiers(Intro, MutableLoc);
1451
1452	if (HasParentheses && Tok.is(K: tok::kw_requires))
1453	ParseTrailingRequiresClause(D);
1454	}
1455
1456	// Emit a warning if we see a CUDA host/device/global attribute
1457	// after '(...)'. nvcc doesn't accept this.
1458	if (getLangOpts().CUDA) {
1459	for (const ParsedAttr &A : Attributes)
1460	if (A.getKind() == ParsedAttr::AT_CUDADevice ||
1461	A.getKind() == ParsedAttr::AT_CUDAHost ||
1462	A.getKind() == ParsedAttr::AT_CUDAGlobal)
1463	Diag(A.getLoc(), diag::warn_cuda_attr_lambda_position)
1464	<< A.getAttrName()->getName();
1465	}
1466
1467	Prototype.Exit();
1468
1469	// FIXME: Rename BlockScope -> ClosureScope if we decide to continue using
1470	// it.
1471	unsigned ScopeFlags = Scope::BlockScope | Scope::FnScope | Scope::DeclScope |
1472	Scope::CompoundStmtScope;
1473	ParseScope BodyScope(this, ScopeFlags);
1474
1475	Actions.ActOnStartOfLambdaDefinition(Intro, ParamInfo&: D, DS);
1476
1477	// Parse compound-statement.
1478	if (!Tok.is(K: tok::l_brace)) {
1479	Diag(Tok, diag::err_expected_lambda_body);
1480	Actions.ActOnLambdaError(StartLoc: LambdaBeginLoc, CurScope: getCurScope());
1481	return ExprError();
1482	}
1483
1484	StmtResult Stmt(ParseCompoundStatementBody());
1485	BodyScope.Exit();
1486	TemplateParamScope.Exit();
1487	LambdaScope.Exit();
1488
1489	if (!Stmt.isInvalid() && !TrailingReturnType.isInvalid() &&
1490	!D.isInvalidType())
1491	return Actions.ActOnLambdaExpr(StartLoc: LambdaBeginLoc, Body: Stmt.get());
1492
1493	Actions.ActOnLambdaError(StartLoc: LambdaBeginLoc, CurScope: getCurScope());
1494	return ExprError();
1495	}
1496
1497	ExprResult Parser::ParseCXXCasts() {
1498	tok::TokenKind Kind = Tok.getKind();
1499	const char *CastName = nullptr; // For error messages
1500
1501	switch (Kind) {
1502	default: llvm_unreachable("Unknown C++ cast!");
1503	case tok::kw_addrspace_cast: CastName = "addrspace_cast"; break;
1504	case tok::kw_const_cast: CastName = "const_cast"; break;
1505	case tok::kw_dynamic_cast: CastName = "dynamic_cast"; break;
1506	case tok::kw_reinterpret_cast: CastName = "reinterpret_cast"; break;
1507	case tok::kw_static_cast: CastName = "static_cast"; break;
1508	}
1509
1510	SourceLocation OpLoc = ConsumeToken();
1511	SourceLocation LAngleBracketLoc = Tok.getLocation();
1512
1513	// Check for "<::" which is parsed as "[:". If found, fix token stream,
1514	// diagnose error, suggest fix, and recover parsing.
1515	if (Tok.is(K: tok::l_square) && Tok.getLength() == 2) {
1516	Token Next = NextToken();
1517	if (Next.is(K: tok::colon) && areTokensAdjacent(First: Tok, Second: Next))
1518	FixDigraph(P&: *this, PP, DigraphToken&: Tok, ColonToken&: Next, Kind, /*AtDigraph*/true);
1519	}
1520
1521	if (ExpectAndConsume(tok::less, diag::err_expected_less_after, CastName))
1522	return ExprError();
1523
1524	// Parse the common declaration-specifiers piece.
1525	DeclSpec DS(AttrFactory);
1526	ParseSpecifierQualifierList(DS, /*AccessSpecifier=*/AS: AS_none,
1527	DSC: DeclSpecContext::DSC_type_specifier);
1528
1529	// Parse the abstract-declarator, if present.
1530	Declarator DeclaratorInfo(DS, ParsedAttributesView::none(),
1531	DeclaratorContext::TypeName);
1532	ParseDeclarator(D&: DeclaratorInfo);
1533
1534	SourceLocation RAngleBracketLoc = Tok.getLocation();
1535
1536	if (ExpectAndConsume(tok::greater))
1537	return ExprError(Diag(LAngleBracketLoc, diag::note_matching) << tok::less);
1538
1539	BalancedDelimiterTracker T(*this, tok::l_paren);
1540
1541	if (T.expectAndConsume(diag::err_expected_lparen_after, CastName))
1542	return ExprError();
1543
1544	ExprResult Result = ParseExpression();
1545
1546	// Match the ')'.
1547	T.consumeClose();
1548
1549	if (!Result.isInvalid() && !DeclaratorInfo.isInvalidType())
1550	Result = Actions.ActOnCXXNamedCast(OpLoc, Kind,
1551	LAngleBracketLoc, D&: DeclaratorInfo,
1552	RAngleBracketLoc,
1553	LParenLoc: T.getOpenLocation(), E: Result.get(),
1554	RParenLoc: T.getCloseLocation());
1555
1556	return Result;
1557	}
1558
1559	ExprResult Parser::ParseCXXTypeid() {
1560	assert(Tok.is(tok::kw_typeid) && "Not 'typeid'!");
1561
1562	SourceLocation OpLoc = ConsumeToken();
1563	SourceLocation LParenLoc, RParenLoc;
1564	BalancedDelimiterTracker T(*this, tok::l_paren);
1565
1566	// typeid expressions are always parenthesized.
1567	if (T.expectAndConsume(diag::err_expected_lparen_after, "typeid"))
1568	return ExprError();
1569	LParenLoc = T.getOpenLocation();
1570
1571	ExprResult Result;
1572
1573	// C++0x [expr.typeid]p3:
1574	// When typeid is applied to an expression other than an lvalue of a
1575	// polymorphic class type [...] The expression is an unevaluated
1576	// operand (Clause 5).
1577	//
1578	// Note that we can't tell whether the expression is an lvalue of a
1579	// polymorphic class type until after we've parsed the expression; we
1580	// speculatively assume the subexpression is unevaluated, and fix it up
1581	// later.
1582	//
1583	// We enter the unevaluated context before trying to determine whether we
1584	// have a type-id, because the tentative parse logic will try to resolve
1585	// names, and must treat them as unevaluated.
1586	EnterExpressionEvaluationContext Unevaluated(
1587	Actions, Sema::ExpressionEvaluationContext::Unevaluated,
1588	Sema::ReuseLambdaContextDecl);
1589
1590	if (isTypeIdInParens()) {
1591	TypeResult Ty = ParseTypeName();
1592
1593	// Match the ')'.
1594	T.consumeClose();
1595	RParenLoc = T.getCloseLocation();
1596	if (Ty.isInvalid() || RParenLoc.isInvalid())
1597	return ExprError();
1598
1599	Result = Actions.ActOnCXXTypeid(OpLoc, LParenLoc, /*isType=*/true,
1600	TyOrExpr: Ty.get().getAsOpaquePtr(), RParenLoc);
1601	} else {
1602	Result = ParseExpression();
1603
1604	// Match the ')'.
1605	if (Result.isInvalid())
1606	SkipUntil(T: tok::r_paren, Flags: StopAtSemi);
1607	else {
1608	T.consumeClose();
1609	RParenLoc = T.getCloseLocation();
1610	if (RParenLoc.isInvalid())
1611	return ExprError();
1612
1613	Result = Actions.ActOnCXXTypeid(OpLoc, LParenLoc, /*isType=*/false,
1614	TyOrExpr: Result.get(), RParenLoc);
1615	}
1616	}
1617
1618	return Result;
1619	}
1620
1621	ExprResult Parser::ParseCXXUuidof() {
1622	assert(Tok.is(tok::kw___uuidof) && "Not '__uuidof'!");
1623
1624	SourceLocation OpLoc = ConsumeToken();
1625	BalancedDelimiterTracker T(*this, tok::l_paren);
1626
1627	// __uuidof expressions are always parenthesized.
1628	if (T.expectAndConsume(diag::err_expected_lparen_after, "__uuidof"))
1629	return ExprError();
1630
1631	ExprResult Result;
1632
1633	if (isTypeIdInParens()) {
1634	TypeResult Ty = ParseTypeName();
1635
1636	// Match the ')'.
1637	T.consumeClose();
1638
1639	if (Ty.isInvalid())
1640	return ExprError();
1641
1642	Result = Actions.ActOnCXXUuidof(OpLoc, LParenLoc: T.getOpenLocation(), /*isType=*/true,
1643	TyOrExpr: Ty.get().getAsOpaquePtr(),
1644	RParenLoc: T.getCloseLocation());
1645	} else {
1646	EnterExpressionEvaluationContext Unevaluated(
1647	Actions, Sema::ExpressionEvaluationContext::Unevaluated);
1648	Result = ParseExpression();
1649
1650	// Match the ')'.
1651	if (Result.isInvalid())
1652	SkipUntil(T: tok::r_paren, Flags: StopAtSemi);
1653	else {
1654	T.consumeClose();
1655
1656	Result = Actions.ActOnCXXUuidof(OpLoc, LParenLoc: T.getOpenLocation(),
1657	/*isType=*/false,
1658	TyOrExpr: Result.get(), RParenLoc: T.getCloseLocation());
1659	}
1660	}
1661
1662	return Result;
1663	}
1664
1665	ExprResult
1666	Parser::ParseCXXPseudoDestructor(Expr *Base, SourceLocation OpLoc,
1667	tok::TokenKind OpKind,
1668	CXXScopeSpec &SS,
1669	ParsedType ObjectType) {
1670	// If the last component of the (optional) nested-name-specifier is
1671	// template[opt] simple-template-id, it has already been annotated.
1672	UnqualifiedId FirstTypeName;
1673	SourceLocation CCLoc;
1674	if (Tok.is(K: tok::identifier)) {
1675	FirstTypeName.setIdentifier(Id: Tok.getIdentifierInfo(), IdLoc: Tok.getLocation());
1676	ConsumeToken();
1677	assert(Tok.is(tok::coloncolon) &&"ParseOptionalCXXScopeSpecifier fail");
1678	CCLoc = ConsumeToken();
1679	} else if (Tok.is(K: tok::annot_template_id)) {
1680	TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(tok: Tok);
1681	// FIXME: Carry on and build an AST representation for tooling.
1682	if (TemplateId->isInvalid())
1683	return ExprError();
1684	FirstTypeName.setTemplateId(TemplateId);
1685	ConsumeAnnotationToken();
1686	assert(Tok.is(tok::coloncolon) &&"ParseOptionalCXXScopeSpecifier fail");
1687	CCLoc = ConsumeToken();
1688	} else {
1689	assert(SS.isEmpty() && "missing last component of nested name specifier");
1690	FirstTypeName.setIdentifier(Id: nullptr, IdLoc: SourceLocation());
1691	}
1692
1693	// Parse the tilde.
1694	assert(Tok.is(tok::tilde) && "ParseOptionalCXXScopeSpecifier fail");
1695	SourceLocation TildeLoc = ConsumeToken();
1696
1697	if (Tok.is(K: tok::kw_decltype) && !FirstTypeName.isValid()) {
1698	DeclSpec DS(AttrFactory);
1699	ParseDecltypeSpecifier(DS);
1700	if (DS.getTypeSpecType() == TST_error)
1701	return ExprError();
1702	return Actions.ActOnPseudoDestructorExpr(S: getCurScope(), Base, OpLoc, OpKind,
1703	TildeLoc, DS);
1704	}
1705
1706	if (!Tok.is(K: tok::identifier)) {
1707	Diag(Tok, diag::err_destructor_tilde_identifier);
1708	return ExprError();
1709	}
1710
1711	// pack-index-specifier
1712	if (GetLookAheadToken(N: 1).is(K: tok::ellipsis) &&
1713	GetLookAheadToken(N: 2).is(K: tok::l_square)) {
1714	DeclSpec DS(AttrFactory);
1715	ParsePackIndexingType(DS);
1716	return Actions.ActOnPseudoDestructorExpr(S: getCurScope(), Base, OpLoc, OpKind,
1717	TildeLoc, DS);
1718	}
1719
1720	// Parse the second type.
1721	UnqualifiedId SecondTypeName;
1722	IdentifierInfo *Name = Tok.getIdentifierInfo();
1723	SourceLocation NameLoc = ConsumeToken();
1724	SecondTypeName.setIdentifier(Id: Name, IdLoc: NameLoc);
1725
1726	// If there is a '<', the second type name is a template-id. Parse
1727	// it as such.
1728	//
1729	// FIXME: This is not a context in which a '<' is assumed to start a template
1730	// argument list. This affects examples such as
1731	// void f(auto *p) { p->~X<int>(); }
1732	// ... but there's no ambiguity, and nowhere to write 'template' in such an
1733	// example, so we accept it anyway.
1734	if (Tok.is(K: tok::less) &&
1735	ParseUnqualifiedIdTemplateId(
1736	SS, ObjectType, ObjectHadErrors: Base && Base->containsErrors(), TemplateKWLoc: SourceLocation(),
1737	Name, NameLoc, EnteringContext: false, Id&: SecondTypeName,
1738	/*AssumeTemplateId=*/true))
1739	return ExprError();
1740
1741	return Actions.ActOnPseudoDestructorExpr(S: getCurScope(), Base, OpLoc, OpKind,
1742	SS, FirstTypeName, CCLoc, TildeLoc,
1743	SecondTypeName);
1744	}
1745
1746	ExprResult Parser::ParseCXXBoolLiteral() {
1747	tok::TokenKind Kind = Tok.getKind();
1748	return Actions.ActOnCXXBoolLiteral(OpLoc: ConsumeToken(), Kind);
1749	}
1750
1751	ExprResult Parser::ParseThrowExpression() {
1752	assert(Tok.is(tok::kw_throw) && "Not throw!");
1753	SourceLocation ThrowLoc = ConsumeToken(); // Eat the throw token.
1754
1755	// If the current token isn't the start of an assignment-expression,
1756	// then the expression is not present. This handles things like:
1757	// "C ? throw : (void)42", which is crazy but legal.
1758	switch (Tok.getKind()) { // FIXME: move this predicate somewhere common.
1759	case tok::semi:
1760	case tok::r_paren:
1761	case tok::r_square:
1762	case tok::r_brace:
1763	case tok::colon:
1764	case tok::comma:
1765	return Actions.ActOnCXXThrow(S: getCurScope(), OpLoc: ThrowLoc, expr: nullptr);
1766
1767	default:
1768	ExprResult Expr(ParseAssignmentExpression());
1769	if (Expr.isInvalid()) return Expr;
1770	return Actions.ActOnCXXThrow(S: getCurScope(), OpLoc: ThrowLoc, expr: Expr.get());
1771	}
1772	}
1773
1774	ExprResult Parser::ParseCoyieldExpression() {
1775	assert(Tok.is(tok::kw_co_yield) && "Not co_yield!");
1776
1777	SourceLocation Loc = ConsumeToken();
1778	ExprResult Expr = Tok.is(K: tok::l_brace) ? ParseBraceInitializer()
1779	: ParseAssignmentExpression();
1780	if (!Expr.isInvalid())
1781	Expr = Actions.ActOnCoyieldExpr(S: getCurScope(), KwLoc: Loc, E: Expr.get());
1782	return Expr;
1783	}
1784
1785	ExprResult Parser::ParseCXXThis() {
1786	assert(Tok.is(tok::kw_this) && "Not 'this'!");
1787	SourceLocation ThisLoc = ConsumeToken();
1788	return Actions.ActOnCXXThis(Loc: ThisLoc);
1789	}
1790
1791	ExprResult
1792	Parser::ParseCXXTypeConstructExpression(const DeclSpec &DS) {
1793	Declarator DeclaratorInfo(DS, ParsedAttributesView::none(),
1794	DeclaratorContext::FunctionalCast);
1795	ParsedType TypeRep = Actions.ActOnTypeName(D&: DeclaratorInfo).get();
1796
1797	assert((Tok.is(tok::l_paren) ||
1798	(getLangOpts().CPlusPlus11 && Tok.is(tok::l_brace)))
1799	&& "Expected '(' or '{'!");
1800
1801	if (Tok.is(K: tok::l_brace)) {
1802	PreferredType.enterTypeCast(Tok.getLocation(), TypeRep.get());
1803	ExprResult Init = ParseBraceInitializer();
1804	if (Init.isInvalid())
1805	return Init;
1806	Expr *InitList = Init.get();
1807	return Actions.ActOnCXXTypeConstructExpr(
1808	TypeRep, LParenOrBraceLoc: InitList->getBeginLoc(), Exprs: MultiExprArg(&InitList, 1),
1809	RParenOrBraceLoc: InitList->getEndLoc(), /*ListInitialization=*/true);
1810	} else {
1811	BalancedDelimiterTracker T(*this, tok::l_paren);
1812	T.consumeOpen();
1813
1814	PreferredType.enterTypeCast(Tok.getLocation(), TypeRep.get());
1815
1816	ExprVector Exprs;
1817
1818	auto RunSignatureHelp = [&]() {
1819	QualType PreferredType;
1820	if (TypeRep)
1821	PreferredType =
1822	Actions.CodeCompletion().ProduceConstructorSignatureHelp(
1823	Type: TypeRep.get()->getCanonicalTypeInternal(), Loc: DS.getEndLoc(),
1824	Args: Exprs, OpenParLoc: T.getOpenLocation(), /*Braced=*/false);
1825	CalledSignatureHelp = true;
1826	return PreferredType;
1827	};
1828
1829	if (Tok.isNot(K: tok::r_paren)) {
1830	if (ParseExpressionList(Exprs, ExpressionStarts: [&] {
1831	PreferredType.enterFunctionArgument(Tok.getLocation(),
1832	RunSignatureHelp);
1833	})) {
1834	if (PP.isCodeCompletionReached() && !CalledSignatureHelp)
1835	RunSignatureHelp();
1836	SkipUntil(T: tok::r_paren, Flags: StopAtSemi);
1837	return ExprError();
1838	}
1839	}
1840
1841	// Match the ')'.
1842	T.consumeClose();
1843
1844	// TypeRep could be null, if it references an invalid typedef.
1845	if (!TypeRep)
1846	return ExprError();
1847
1848	return Actions.ActOnCXXTypeConstructExpr(TypeRep, LParenOrBraceLoc: T.getOpenLocation(),
1849	Exprs, RParenOrBraceLoc: T.getCloseLocation(),
1850	/*ListInitialization=*/false);
1851	}
1852	}
1853
1854	Parser::DeclGroupPtrTy
1855	Parser::ParseAliasDeclarationInInitStatement(DeclaratorContext Context,
1856	ParsedAttributes &Attrs) {
1857	assert(Tok.is(tok::kw_using) && "Expected using");
1858	assert((Context == DeclaratorContext::ForInit ||
1859	Context == DeclaratorContext::SelectionInit) &&
1860	"Unexpected Declarator Context");
1861	DeclGroupPtrTy DG;
1862	SourceLocation DeclStart = ConsumeToken(), DeclEnd;
1863
1864	DG = ParseUsingDeclaration(Context, TemplateInfo: {}, UsingLoc: DeclStart, DeclEnd, Attrs, AS: AS_none);
1865	if (!DG)
1866	return DG;
1867
1868	Diag(DeclStart, !getLangOpts().CPlusPlus23
1869	? diag::ext_alias_in_init_statement
1870	: diag::warn_cxx20_alias_in_init_statement)
1871	<< SourceRange(DeclStart, DeclEnd);
1872
1873	return DG;
1874	}
1875
1876	Sema::ConditionResult
1877	Parser::ParseCXXCondition(StmtResult *InitStmt, SourceLocation Loc,
1878	Sema::ConditionKind CK, bool MissingOK,
1879	ForRangeInfo *FRI, bool EnterForConditionScope) {
1880	// Helper to ensure we always enter a continue/break scope if requested.
1881	struct ForConditionScopeRAII {
1882	Scope *S;
1883	void enter(bool IsConditionVariable) {
1884	if (S) {
1885	S->AddFlags(Flags: Scope::BreakScope | Scope::ContinueScope);
1886	S->setIsConditionVarScope(IsConditionVariable);
1887	}
1888	}
1889	~ForConditionScopeRAII() {
1890	if (S)
1891	S->setIsConditionVarScope(false);
1892	}
1893	} ForConditionScope{.S: EnterForConditionScope ? getCurScope() : nullptr};
1894
1895	ParenBraceBracketBalancer BalancerRAIIObj(*this);
1896	PreferredType.enterCondition(Actions, Tok.getLocation());
1897
1898	if (Tok.is(K: tok::code_completion)) {
1899	cutOffParsing();
1900	Actions.CodeCompletion().CodeCompleteOrdinaryName(
1901	S: getCurScope(), CompletionContext: SemaCodeCompletion::PCC_Condition);
1902	return Sema::ConditionError();
1903	}
1904
1905	ParsedAttributes attrs(AttrFactory);
1906	MaybeParseCXX11Attributes(Attrs&: attrs);
1907
1908	const auto WarnOnInit = [this, &CK] {
1909	Diag(Tok.getLocation(), getLangOpts().CPlusPlus17
1910	? diag::warn_cxx14_compat_init_statement
1911	: diag::ext_init_statement)
1912	<< (CK == Sema::ConditionKind::Switch);
1913	};
1914
1915	// Determine what kind of thing we have.
1916	switch (isCXXConditionDeclarationOrInitStatement(CanBeInitStmt: InitStmt, CanBeForRangeDecl: FRI)) {
1917	case ConditionOrInitStatement::Expression: {
1918	// If this is a for loop, we're entering its condition.
1919	ForConditionScope.enter(/*IsConditionVariable=*/false);
1920
1921	ProhibitAttributes(Attrs&: attrs);
1922
1923	// We can have an empty expression here.
1924	// if (; true);
1925	if (InitStmt && Tok.is(K: tok::semi)) {
1926	WarnOnInit();
1927	SourceLocation SemiLoc = Tok.getLocation();
1928	if (!Tok.hasLeadingEmptyMacro() && !SemiLoc.isMacroID()) {
1929	Diag(SemiLoc, diag::warn_empty_init_statement)
1930	<< (CK == Sema::ConditionKind::Switch)
1931	<< FixItHint::CreateRemoval(SemiLoc);
1932	}
1933	ConsumeToken();
1934	*InitStmt = Actions.ActOnNullStmt(SemiLoc);
1935	return ParseCXXCondition(InitStmt: nullptr, Loc, CK, MissingOK);
1936	}
1937
1938	ExprResult Expr = [&] {
1939	EnterExpressionEvaluationContext Eval(
1940	Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated,
1941	/*LambdaContextDecl=*/nullptr,
1942	/*ExprContext=*/Sema::ExpressionEvaluationContextRecord::EK_Other,
1943	/*ShouldEnter=*/CK == Sema::ConditionKind::ConstexprIf);
1944	// Parse the expression.
1945	return ParseExpression(); // expression
1946	}();
1947
1948	if (Expr.isInvalid())
1949	return Sema::ConditionError();
1950
1951	if (InitStmt && Tok.is(K: tok::semi)) {
1952	WarnOnInit();
1953	*InitStmt = Actions.ActOnExprStmt(Arg: Expr.get());
1954	ConsumeToken();
1955	return ParseCXXCondition(InitStmt: nullptr, Loc, CK, MissingOK);
1956	}
1957
1958	return Actions.ActOnCondition(S: getCurScope(), Loc, SubExpr: Expr.get(), CK,
1959	MissingOK);
1960	}
1961
1962	case ConditionOrInitStatement::InitStmtDecl: {
1963	WarnOnInit();
1964	DeclGroupPtrTy DG;
1965	SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
1966	if (Tok.is(K: tok::kw_using))
1967	DG = ParseAliasDeclarationInInitStatement(
1968	Context: DeclaratorContext::SelectionInit, Attrs&: attrs);
1969	else {
1970	ParsedAttributes DeclSpecAttrs(AttrFactory);
1971	DG = ParseSimpleDeclaration(Context: DeclaratorContext::SelectionInit, DeclEnd,
1972	DeclAttrs&: attrs, DeclSpecAttrs, /*RequireSemi=*/true);
1973	}
1974	*InitStmt = Actions.ActOnDeclStmt(Decl: DG, StartLoc: DeclStart, EndLoc: DeclEnd);
1975	return ParseCXXCondition(InitStmt: nullptr, Loc, CK, MissingOK);
1976	}
1977
1978	case ConditionOrInitStatement::ForRangeDecl: {
1979	// This is 'for (init-stmt; for-range-decl : range-expr)'.
1980	// We're not actually in a for loop yet, so 'break' and 'continue' aren't
1981	// permitted here.
1982	assert(FRI && "should not parse a for range declaration here");
1983	SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
1984	ParsedAttributes DeclSpecAttrs(AttrFactory);
1985	DeclGroupPtrTy DG = ParseSimpleDeclaration(
1986	Context: DeclaratorContext::ForInit, DeclEnd, DeclAttrs&: attrs, DeclSpecAttrs, RequireSemi: false, FRI);
1987	FRI->LoopVar = Actions.ActOnDeclStmt(Decl: DG, StartLoc: DeclStart, EndLoc: Tok.getLocation());
1988	return Sema::ConditionResult();
1989	}
1990
1991	case ConditionOrInitStatement::ConditionDecl:
1992	case ConditionOrInitStatement::Error:
1993	break;
1994	}
1995
1996	// If this is a for loop, we're entering its condition.
1997	ForConditionScope.enter(/*IsConditionVariable=*/true);
1998
1999	// type-specifier-seq
2000	DeclSpec DS(AttrFactory);
2001	ParseSpecifierQualifierList(DS, AS: AS_none, DSC: DeclSpecContext::DSC_condition);
2002
2003	// declarator
2004	Declarator DeclaratorInfo(DS, attrs, DeclaratorContext::Condition);
2005	ParseDeclarator(D&: DeclaratorInfo);
2006
2007	// simple-asm-expr[opt]
2008	if (Tok.is(K: tok::kw_asm)) {
2009	SourceLocation Loc;
2010	ExprResult AsmLabel(ParseSimpleAsm(/*ForAsmLabel*/ true, EndLoc: &Loc));
2011	if (AsmLabel.isInvalid()) {
2012	SkipUntil(T: tok::semi, Flags: StopAtSemi);
2013	return Sema::ConditionError();
2014	}
2015	DeclaratorInfo.setAsmLabel(AsmLabel.get());
2016	DeclaratorInfo.SetRangeEnd(Loc);
2017	}
2018
2019	// If attributes are present, parse them.
2020	MaybeParseGNUAttributes(D&: DeclaratorInfo);
2021
2022	// Type-check the declaration itself.
2023	DeclResult Dcl = Actions.ActOnCXXConditionDeclaration(S: getCurScope(),
2024	D&: DeclaratorInfo);
2025	if (Dcl.isInvalid())
2026	return Sema::ConditionError();
2027	Decl *DeclOut = Dcl.get();
2028
2029	// '=' assignment-expression
2030	// If a '==' or '+=' is found, suggest a fixit to '='.
2031	bool CopyInitialization = isTokenEqualOrEqualTypo();
2032	if (CopyInitialization)
2033	ConsumeToken();
2034
2035	ExprResult InitExpr = ExprError();
2036	if (getLangOpts().CPlusPlus11 && Tok.is(K: tok::l_brace)) {
2037	Diag(Tok.getLocation(),
2038	diag::warn_cxx98_compat_generalized_initializer_lists);
2039	InitExpr = ParseBraceInitializer();
2040	} else if (CopyInitialization) {
2041	PreferredType.enterVariableInit(Tok.getLocation(), DeclOut);
2042	InitExpr = ParseAssignmentExpression();
2043	} else if (Tok.is(K: tok::l_paren)) {
2044	// This was probably an attempt to initialize the variable.
2045	SourceLocation LParen = ConsumeParen(), RParen = LParen;
2046	if (SkipUntil(T: tok::r_paren, Flags: StopAtSemi | StopBeforeMatch))
2047	RParen = ConsumeParen();
2048	Diag(DeclOut->getLocation(),
2049	diag::err_expected_init_in_condition_lparen)
2050	<< SourceRange(LParen, RParen);
2051	} else {
2052	Diag(DeclOut->getLocation(), diag::err_expected_init_in_condition);
2053	}
2054
2055	if (!InitExpr.isInvalid())
2056	Actions.AddInitializerToDecl(dcl: DeclOut, init: InitExpr.get(), DirectInit: !CopyInitialization);
2057	else
2058	Actions.ActOnInitializerError(Dcl: DeclOut);
2059
2060	Actions.FinalizeDeclaration(D: DeclOut);
2061	return Actions.ActOnConditionVariable(ConditionVar: DeclOut, StmtLoc: Loc, CK);
2062	}
2063
2064	void Parser::ParseCXXSimpleTypeSpecifier(DeclSpec &DS) {
2065	DS.SetRangeStart(Tok.getLocation());
2066	const char *PrevSpec;
2067	unsigned DiagID;
2068	SourceLocation Loc = Tok.getLocation();
2069	const clang::PrintingPolicy &Policy =
2070	Actions.getASTContext().getPrintingPolicy();
2071
2072	switch (Tok.getKind()) {
2073	case tok::identifier: // foo::bar
2074	case tok::coloncolon: // ::foo::bar
2075	llvm_unreachable("Annotation token should already be formed!");
2076	default:
2077	llvm_unreachable("Not a simple-type-specifier token!");
2078
2079	// type-name
2080	case tok::annot_typename: {
2081	DS.SetTypeSpecType(T: DeclSpec::TST_typename, Loc, PrevSpec, DiagID,
2082	Rep: getTypeAnnotation(Tok), Policy);
2083	DS.SetRangeEnd(Tok.getAnnotationEndLoc());
2084	ConsumeAnnotationToken();
2085	DS.Finish(S&: Actions, Policy);
2086	return;
2087	}
2088
2089	case tok::kw__ExtInt:
2090	case tok::kw__BitInt: {
2091	DiagnoseBitIntUse(Tok);
2092	ExprResult ER = ParseExtIntegerArgument();
2093	if (ER.isInvalid())
2094	DS.SetTypeSpecError();
2095	else
2096	DS.SetBitIntType(KWLoc: Loc, BitWidth: ER.get(), PrevSpec, DiagID, Policy);
2097
2098	// Do this here because we have already consumed the close paren.
2099	DS.SetRangeEnd(PrevTokLocation);
2100	DS.Finish(S&: Actions, Policy);
2101	return;
2102	}
2103
2104	// builtin types
2105	case tok::kw_short:
2106	DS.SetTypeSpecWidth(W: TypeSpecifierWidth::Short, Loc, PrevSpec, DiagID,
2107	Policy);
2108	break;
2109	case tok::kw_long:
2110	DS.SetTypeSpecWidth(W: TypeSpecifierWidth::Long, Loc, PrevSpec, DiagID,
2111	Policy);
2112	break;
2113	case tok::kw___int64:
2114	DS.SetTypeSpecWidth(W: TypeSpecifierWidth::LongLong, Loc, PrevSpec, DiagID,
2115	Policy);
2116	break;
2117	case tok::kw_signed:
2118	DS.SetTypeSpecSign(S: TypeSpecifierSign::Signed, Loc, PrevSpec, DiagID);
2119	break;
2120	case tok::kw_unsigned:
2121	DS.SetTypeSpecSign(S: TypeSpecifierSign::Unsigned, Loc, PrevSpec, DiagID);
2122	break;
2123	case tok::kw_void:
2124	DS.SetTypeSpecType(T: DeclSpec::TST_void, Loc, PrevSpec, DiagID, Policy);
2125	break;
2126	case tok::kw_auto:
2127	DS.SetTypeSpecType(T: DeclSpec::TST_auto, Loc, PrevSpec, DiagID, Policy);
2128	break;
2129	case tok::kw_char:
2130	DS.SetTypeSpecType(T: DeclSpec::TST_char, Loc, PrevSpec, DiagID, Policy);
2131	break;
2132	case tok::kw_int:
2133	DS.SetTypeSpecType(T: DeclSpec::TST_int, Loc, PrevSpec, DiagID, Policy);
2134	break;
2135	case tok::kw___int128:
2136	DS.SetTypeSpecType(T: DeclSpec::TST_int128, Loc, PrevSpec, DiagID, Policy);
2137	break;
2138	case tok::kw___bf16:
2139	DS.SetTypeSpecType(T: DeclSpec::TST_BFloat16, Loc, PrevSpec, DiagID, Policy);
2140	break;
2141	case tok::kw_half:
2142	DS.SetTypeSpecType(T: DeclSpec::TST_half, Loc, PrevSpec, DiagID, Policy);
2143	break;
2144	case tok::kw_float:
2145	DS.SetTypeSpecType(T: DeclSpec::TST_float, Loc, PrevSpec, DiagID, Policy);
2146	break;
2147	case tok::kw_double:
2148	DS.SetTypeSpecType(T: DeclSpec::TST_double, Loc, PrevSpec, DiagID, Policy);
2149	break;
2150	case tok::kw__Float16:
2151	DS.SetTypeSpecType(T: DeclSpec::TST_float16, Loc, PrevSpec, DiagID, Policy);
2152	break;
2153	case tok::kw___float128:
2154	DS.SetTypeSpecType(T: DeclSpec::TST_float128, Loc, PrevSpec, DiagID, Policy);
2155	break;
2156	case tok::kw___ibm128:
2157	DS.SetTypeSpecType(T: DeclSpec::TST_ibm128, Loc, PrevSpec, DiagID, Policy);
2158	break;
2159	case tok::kw_wchar_t:
2160	DS.SetTypeSpecType(T: DeclSpec::TST_wchar, Loc, PrevSpec, DiagID, Policy);
2161	break;
2162	case tok::kw_char8_t:
2163	DS.SetTypeSpecType(T: DeclSpec::TST_char8, Loc, PrevSpec, DiagID, Policy);
2164	break;
2165	case tok::kw_char16_t:
2166	DS.SetTypeSpecType(T: DeclSpec::TST_char16, Loc, PrevSpec, DiagID, Policy);
2167	break;
2168	case tok::kw_char32_t:
2169	DS.SetTypeSpecType(T: DeclSpec::TST_char32, Loc, PrevSpec, DiagID, Policy);
2170	break;
2171	case tok::kw_bool:
2172	DS.SetTypeSpecType(T: DeclSpec::TST_bool, Loc, PrevSpec, DiagID, Policy);
2173	break;
2174	case tok::kw__Accum:
2175	DS.SetTypeSpecType(T: DeclSpec::TST_accum, Loc, PrevSpec, DiagID, Policy);
2176	break;
2177	case tok::kw__Fract:
2178	DS.SetTypeSpecType(T: DeclSpec::TST_fract, Loc, PrevSpec, DiagID, Policy);
2179	break;
2180	case tok::kw__Sat:
2181	DS.SetTypeSpecSat(Loc, PrevSpec, DiagID);
2182	break;
2183	#define GENERIC_IMAGE_TYPE(ImgType, Id) \
2184	case tok::kw_##ImgType##_t: \
2185	DS.SetTypeSpecType(DeclSpec::TST_##ImgType##_t, Loc, PrevSpec, DiagID, \
2186	Policy); \
2187	break;
2188	#include "clang/Basic/OpenCLImageTypes.def"
2189	#define HLSL_INTANGIBLE_TYPE(Name, Id, SingletonId) \
2190	case tok::kw_##Name: \
2191	DS.SetTypeSpecType(DeclSpec::TST_##Name, Loc, PrevSpec, DiagID, Policy); \
2192	break;
2193	#include "clang/Basic/HLSLIntangibleTypes.def"
2194
2195	case tok::annot_decltype:
2196	case tok::kw_decltype:
2197	DS.SetRangeEnd(ParseDecltypeSpecifier(DS));
2198	return DS.Finish(S&: Actions, Policy);
2199
2200	case tok::annot_pack_indexing_type:
2201	DS.SetRangeEnd(ParsePackIndexingType(DS));
2202	return DS.Finish(S&: Actions, Policy);
2203
2204	// GNU typeof support.
2205	case tok::kw_typeof:
2206	ParseTypeofSpecifier(DS);
2207	DS.Finish(S&: Actions, Policy);
2208	return;
2209	}
2210	ConsumeAnyToken();
2211	DS.SetRangeEnd(PrevTokLocation);
2212	DS.Finish(S&: Actions, Policy);
2213	}
2214
2215	bool Parser::ParseCXXTypeSpecifierSeq(DeclSpec &DS, DeclaratorContext Context) {
2216	ParseSpecifierQualifierList(DS, AS: AS_none,
2217	DSC: getDeclSpecContextFromDeclaratorContext(Context));
2218	DS.Finish(S&: Actions, Policy: Actions.getASTContext().getPrintingPolicy());
2219	return false;
2220	}
2221
2222	bool Parser::ParseUnqualifiedIdTemplateId(
2223	CXXScopeSpec &SS, ParsedType ObjectType, bool ObjectHadErrors,
2224	SourceLocation TemplateKWLoc, IdentifierInfo *Name, SourceLocation NameLoc,
2225	bool EnteringContext, UnqualifiedId &Id, bool AssumeTemplateId) {
2226	assert(Tok.is(tok::less) && "Expected '<' to finish parsing a template-id");
2227
2228	TemplateTy Template;
2229	TemplateNameKind TNK = TNK_Non_template;
2230	switch (Id.getKind()) {
2231	case UnqualifiedIdKind::IK_Identifier:
2232	case UnqualifiedIdKind::IK_OperatorFunctionId:
2233	case UnqualifiedIdKind::IK_LiteralOperatorId:
2234	if (AssumeTemplateId) {
2235	// We defer the injected-class-name checks until we've found whether
2236	// this template-id is used to form a nested-name-specifier or not.
2237	TNK = Actions.ActOnTemplateName(S: getCurScope(), SS, TemplateKWLoc, Name: Id,
2238	ObjectType, EnteringContext, Template,
2239	/*AllowInjectedClassName*/ true);
2240	} else {
2241	bool MemberOfUnknownSpecialization;
2242	TNK = Actions.isTemplateName(S: getCurScope(), SS,
2243	hasTemplateKeyword: TemplateKWLoc.isValid(), Name: Id,
2244	ObjectType, EnteringContext, Template,
2245	MemberOfUnknownSpecialization);
2246	// If lookup found nothing but we're assuming that this is a template
2247	// name, double-check that makes sense syntactically before committing
2248	// to it.
2249	if (TNK == TNK_Undeclared_template &&
2250	isTemplateArgumentList(TokensToSkip: 0) == TPResult::False)
2251	return false;
2252
2253	if (TNK == TNK_Non_template && MemberOfUnknownSpecialization &&
2254	ObjectType && isTemplateArgumentList(TokensToSkip: 0) == TPResult::True) {
2255	// If we had errors before, ObjectType can be dependent even without any
2256	// templates, do not report missing template keyword in that case.
2257	if (!ObjectHadErrors) {
2258	// We have something like t->getAs<T>(), where getAs is a
2259	// member of an unknown specialization. However, this will only
2260	// parse correctly as a template, so suggest the keyword 'template'
2261	// before 'getAs' and treat this as a dependent template name.
2262	std::string Name;
2263	if (Id.getKind() == UnqualifiedIdKind::IK_Identifier)
2264	Name = std::string(Id.Identifier->getName());
2265	else {
2266	Name = "operator ";
2267	if (Id.getKind() == UnqualifiedIdKind::IK_OperatorFunctionId)
2268	Name += getOperatorSpelling(Operator: Id.OperatorFunctionId.Operator);
2269	else
2270	Name += Id.Identifier->getName();
2271	}
2272	Diag(Id.StartLocation, diag::err_missing_dependent_template_keyword)
2273	<< Name
2274	<< FixItHint::CreateInsertion(Id.StartLocation, "template ");
2275	}
2276	TNK = Actions.ActOnTemplateName(
2277	S: getCurScope(), SS, TemplateKWLoc, Name: Id, ObjectType, EnteringContext,
2278	Template, /*AllowInjectedClassName*/ true);
2279	} else if (TNK == TNK_Non_template) {
2280	return false;
2281	}
2282	}
2283	break;
2284
2285	case UnqualifiedIdKind::IK_ConstructorName: {
2286	UnqualifiedId TemplateName;
2287	bool MemberOfUnknownSpecialization;
2288	TemplateName.setIdentifier(Id: Name, IdLoc: NameLoc);
2289	TNK = Actions.isTemplateName(S: getCurScope(), SS, hasTemplateKeyword: TemplateKWLoc.isValid(),
2290	Name: TemplateName, ObjectType,
2291	EnteringContext, Template,
2292	MemberOfUnknownSpecialization);
2293	if (TNK == TNK_Non_template)
2294	return false;
2295	break;
2296	}
2297
2298	case UnqualifiedIdKind::IK_DestructorName: {
2299	UnqualifiedId TemplateName;
2300	bool MemberOfUnknownSpecialization;
2301	TemplateName.setIdentifier(Id: Name, IdLoc: NameLoc);
2302	if (ObjectType) {
2303	TNK = Actions.ActOnTemplateName(
2304	S: getCurScope(), SS, TemplateKWLoc, Name: TemplateName, ObjectType,
2305	EnteringContext, Template, /*AllowInjectedClassName*/ true);
2306	} else {
2307	TNK = Actions.isTemplateName(S: getCurScope(), SS, hasTemplateKeyword: TemplateKWLoc.isValid(),
2308	Name: TemplateName, ObjectType,
2309	EnteringContext, Template,
2310	MemberOfUnknownSpecialization);
2311
2312	if (TNK == TNK_Non_template && !Id.DestructorName.get()) {
2313	Diag(NameLoc, diag::err_destructor_template_id)
2314	<< Name << SS.getRange();
2315	// Carry on to parse the template arguments before bailing out.
2316	}
2317	}
2318	break;
2319	}
2320
2321	default:
2322	return false;
2323	}
2324
2325	// Parse the enclosed template argument list.
2326	SourceLocation LAngleLoc, RAngleLoc;
2327	TemplateArgList TemplateArgs;
2328	if (ParseTemplateIdAfterTemplateName(ConsumeLastToken: true, LAngleLoc, TemplateArgs, RAngleLoc,
2329	NameHint: Template))
2330	return true;
2331
2332	// If this is a non-template, we already issued a diagnostic.
2333	if (TNK == TNK_Non_template)
2334	return true;
2335
2336	if (Id.getKind() == UnqualifiedIdKind::IK_Identifier ||
2337	Id.getKind() == UnqualifiedIdKind::IK_OperatorFunctionId ||
2338	Id.getKind() == UnqualifiedIdKind::IK_LiteralOperatorId) {
2339	// Form a parsed representation of the template-id to be stored in the
2340	// UnqualifiedId.
2341
2342	// FIXME: Store name for literal operator too.
2343	const IdentifierInfo *TemplateII =
2344	Id.getKind() == UnqualifiedIdKind::IK_Identifier ? Id.Identifier
2345	: nullptr;
2346	OverloadedOperatorKind OpKind =
2347	Id.getKind() == UnqualifiedIdKind::IK_Identifier
2348	? OO_None
2349	: Id.OperatorFunctionId.Operator;
2350
2351	TemplateIdAnnotation *TemplateId = TemplateIdAnnotation::Create(
2352	TemplateKWLoc, TemplateNameLoc: Id.StartLocation, Name: TemplateII, OperatorKind: OpKind, OpaqueTemplateName: Template, TemplateKind: TNK,
2353	LAngleLoc, RAngleLoc, TemplateArgs, /*ArgsInvalid*/false, CleanupList&: TemplateIds);
2354
2355	Id.setTemplateId(TemplateId);
2356	return false;
2357	}
2358
2359	// Bundle the template arguments together.
2360	ASTTemplateArgsPtr TemplateArgsPtr(TemplateArgs);
2361
2362	// Constructor and destructor names.
2363	TypeResult Type = Actions.ActOnTemplateIdType(
2364	S: getCurScope(), SS, TemplateKWLoc, Template, TemplateII: Name, TemplateIILoc: NameLoc, LAngleLoc,
2365	TemplateArgs: TemplateArgsPtr, RAngleLoc, /*IsCtorOrDtorName=*/true);
2366	if (Type.isInvalid())
2367	return true;
2368
2369	if (Id.getKind() == UnqualifiedIdKind::IK_ConstructorName)
2370	Id.setConstructorName(ClassType: Type.get(), ClassNameLoc: NameLoc, EndLoc: RAngleLoc);
2371	else
2372	Id.setDestructorName(TildeLoc: Id.StartLocation, ClassType: Type.get(), EndLoc: RAngleLoc);
2373
2374	return false;
2375	}
2376
2377	bool Parser::ParseUnqualifiedIdOperator(CXXScopeSpec &SS, bool EnteringContext,
2378	ParsedType ObjectType,
2379	UnqualifiedId &Result) {
2380	assert(Tok.is(tok::kw_operator) && "Expected 'operator' keyword");
2381
2382	// Consume the 'operator' keyword.
2383	SourceLocation KeywordLoc = ConsumeToken();
2384
2385	// Determine what kind of operator name we have.
2386	unsigned SymbolIdx = 0;
2387	SourceLocation SymbolLocations[3];
2388	OverloadedOperatorKind Op = OO_None;
2389	switch (Tok.getKind()) {
2390	case tok::kw_new:
2391	case tok::kw_delete: {
2392	bool isNew = Tok.getKind() == tok::kw_new;
2393	// Consume the 'new' or 'delete'.
2394	SymbolLocations[SymbolIdx++] = ConsumeToken();
2395	// Check for array new/delete.
2396	if (Tok.is(K: tok::l_square) &&
2397	(!getLangOpts().CPlusPlus11 || NextToken().isNot(K: tok::l_square))) {
2398	// Consume the '[' and ']'.
2399	BalancedDelimiterTracker T(*this, tok::l_square);
2400	T.consumeOpen();
2401	T.consumeClose();
2402	if (T.getCloseLocation().isInvalid())
2403	return true;
2404
2405	SymbolLocations[SymbolIdx++] = T.getOpenLocation();
2406	SymbolLocations[SymbolIdx++] = T.getCloseLocation();
2407	Op = isNew? OO_Array_New : OO_Array_Delete;
2408	} else {
2409	Op = isNew? OO_New : OO_Delete;
2410	}
2411	break;
2412	}
2413
2414	#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
2415	case tok::Token: \
2416	SymbolLocations[SymbolIdx++] = ConsumeToken(); \
2417	Op = OO_##Name; \
2418	break;
2419	#define OVERLOADED_OPERATOR_MULTI(Name,Spelling,Unary,Binary,MemberOnly)
2420	#include "clang/Basic/OperatorKinds.def"
2421
2422	case tok::l_paren: {
2423	// Consume the '(' and ')'.
2424	BalancedDelimiterTracker T(*this, tok::l_paren);
2425	T.consumeOpen();
2426	T.consumeClose();
2427	if (T.getCloseLocation().isInvalid())
2428	return true;
2429
2430	SymbolLocations[SymbolIdx++] = T.getOpenLocation();
2431	SymbolLocations[SymbolIdx++] = T.getCloseLocation();
2432	Op = OO_Call;
2433	break;
2434	}
2435
2436	case tok::l_square: {
2437	// Consume the '[' and ']'.
2438	BalancedDelimiterTracker T(*this, tok::l_square);
2439	T.consumeOpen();
2440	T.consumeClose();
2441	if (T.getCloseLocation().isInvalid())
2442	return true;
2443
2444	SymbolLocations[SymbolIdx++] = T.getOpenLocation();
2445	SymbolLocations[SymbolIdx++] = T.getCloseLocation();
2446	Op = OO_Subscript;
2447	break;
2448	}
2449
2450	case tok::code_completion: {
2451	// Don't try to parse any further.
2452	cutOffParsing();
2453	// Code completion for the operator name.
2454	Actions.CodeCompletion().CodeCompleteOperatorName(S: getCurScope());
2455	return true;
2456	}
2457
2458	default:
2459	break;
2460	}
2461
2462	if (Op != OO_None) {
2463	// We have parsed an operator-function-id.
2464	Result.setOperatorFunctionId(OperatorLoc: KeywordLoc, Op, SymbolLocations);
2465	return false;
2466	}
2467
2468	// Parse a literal-operator-id.
2469	//
2470	// literal-operator-id: C++11 [over.literal]
2471	// operator string-literal identifier
2472	// operator user-defined-string-literal
2473
2474	if (getLangOpts().CPlusPlus11 && isTokenStringLiteral()) {
2475	Diag(Tok.getLocation(), diag::warn_cxx98_compat_literal_operator);
2476
2477	SourceLocation DiagLoc;
2478	unsigned DiagId = 0;
2479
2480	// We're past translation phase 6, so perform string literal concatenation
2481	// before checking for "".
2482	SmallVector<Token, 4> Toks;
2483	SmallVector<SourceLocation, 4> TokLocs;
2484	while (isTokenStringLiteral()) {
2485	if (!Tok.is(K: tok::string_literal) && !DiagId) {
2486	// C++11 [over.literal]p1:
2487	// The string-literal or user-defined-string-literal in a
2488	// literal-operator-id shall have no encoding-prefix [...].
2489	DiagLoc = Tok.getLocation();
2490	DiagId = diag::err_literal_operator_string_prefix;
2491	}
2492	Toks.push_back(Elt: Tok);
2493	TokLocs.push_back(Elt: ConsumeStringToken());
2494	}
2495
2496	StringLiteralParser Literal(Toks, PP);
2497	if (Literal.hadError)
2498	return true;
2499
2500	// Grab the literal operator's suffix, which will be either the next token
2501	// or a ud-suffix from the string literal.
2502	bool IsUDSuffix = !Literal.getUDSuffix().empty();
2503	IdentifierInfo *II = nullptr;
2504	SourceLocation SuffixLoc;
2505	if (IsUDSuffix) {
2506	II = &PP.getIdentifierTable().get(Name: Literal.getUDSuffix());
2507	SuffixLoc =
2508	Lexer::AdvanceToTokenCharacter(TokStart: TokLocs[Literal.getUDSuffixToken()],
2509	Characters: Literal.getUDSuffixOffset(),
2510	SM: PP.getSourceManager(), LangOpts: getLangOpts());
2511	} else if (Tok.is(K: tok::identifier)) {
2512	II = Tok.getIdentifierInfo();
2513	SuffixLoc = ConsumeToken();
2514	TokLocs.push_back(Elt: SuffixLoc);
2515	} else {
2516	Diag(Tok.getLocation(), diag::err_expected) << tok::identifier;
2517	return true;
2518	}
2519
2520	// The string literal must be empty.
2521	if (!Literal.GetString().empty() || Literal.Pascal) {
2522	// C++11 [over.literal]p1:
2523	// The string-literal or user-defined-string-literal in a
2524	// literal-operator-id shall [...] contain no characters
2525	// other than the implicit terminating '\0'.
2526	DiagLoc = TokLocs.front();
2527	DiagId = diag::err_literal_operator_string_not_empty;
2528	}
2529
2530	if (DiagId) {
2531	// This isn't a valid literal-operator-id, but we think we know
2532	// what the user meant. Tell them what they should have written.
2533	SmallString<32> Str;
2534	Str += "\"\"";
2535	Str += II->getName();
2536	Diag(Loc: DiagLoc, DiagID: DiagId) << FixItHint::CreateReplacement(
2537	RemoveRange: SourceRange(TokLocs.front(), TokLocs.back()), Code: Str);
2538	}
2539
2540	Result.setLiteralOperatorId(Id: II, OpLoc: KeywordLoc, IdLoc: SuffixLoc);
2541
2542	return Actions.checkLiteralOperatorId(SS, Id: Result, IsUDSuffix);
2543	}
2544
2545	// Parse a conversion-function-id.
2546	//
2547	// conversion-function-id: [C++ 12.3.2]
2548	// operator conversion-type-id
2549	//
2550	// conversion-type-id:
2551	// type-specifier-seq conversion-declarator[opt]
2552	//
2553	// conversion-declarator:
2554	// ptr-operator conversion-declarator[opt]
2555
2556	// Parse the type-specifier-seq.
2557	DeclSpec DS(AttrFactory);
2558	if (ParseCXXTypeSpecifierSeq(
2559	DS, Context: DeclaratorContext::ConversionId)) // FIXME: ObjectType?
2560	return true;
2561
2562	// Parse the conversion-declarator, which is merely a sequence of
2563	// ptr-operators.
2564	Declarator D(DS, ParsedAttributesView::none(),
2565	DeclaratorContext::ConversionId);
2566	ParseDeclaratorInternal(D, /*DirectDeclParser=*/nullptr);
2567
2568	// Finish up the type.
2569	TypeResult Ty = Actions.ActOnTypeName(D);
2570	if (Ty.isInvalid())
2571	return true;
2572
2573	// Note that this is a conversion-function-id.
2574	Result.setConversionFunctionId(OperatorLoc: KeywordLoc, Ty: Ty.get(),
2575	EndLoc: D.getSourceRange().getEnd());
2576	return false;
2577	}
2578
2579	bool Parser::ParseUnqualifiedId(CXXScopeSpec &SS, ParsedType ObjectType,
2580	bool ObjectHadErrors, bool EnteringContext,
2581	bool AllowDestructorName,
2582	bool AllowConstructorName,
2583	bool AllowDeductionGuide,
2584	SourceLocation *TemplateKWLoc,
2585	UnqualifiedId &Result) {
2586	if (TemplateKWLoc)
2587	*TemplateKWLoc = SourceLocation();
2588
2589	// Handle 'A::template B'. This is for template-ids which have not
2590	// already been annotated by ParseOptionalCXXScopeSpecifier().
2591	bool TemplateSpecified = false;
2592	if (Tok.is(K: tok::kw_template)) {
2593	if (TemplateKWLoc && (ObjectType || SS.isSet())) {
2594	TemplateSpecified = true;
2595	*TemplateKWLoc = ConsumeToken();
2596	} else {
2597	SourceLocation TemplateLoc = ConsumeToken();
2598	Diag(TemplateLoc, diag::err_unexpected_template_in_unqualified_id)
2599	<< FixItHint::CreateRemoval(TemplateLoc);
2600	}
2601	}
2602
2603	// unqualified-id:
2604	// identifier
2605	// template-id (when it hasn't already been annotated)
2606	if (Tok.is(K: tok::identifier)) {
2607	ParseIdentifier:
2608	// Consume the identifier.
2609	IdentifierInfo *Id = Tok.getIdentifierInfo();
2610	SourceLocation IdLoc = ConsumeToken();
2611
2612	if (!getLangOpts().CPlusPlus) {
2613	// If we're not in C++, only identifiers matter. Record the
2614	// identifier and return.
2615	Result.setIdentifier(Id, IdLoc);
2616	return false;
2617	}
2618
2619	ParsedTemplateTy TemplateName;
2620	if (AllowConstructorName &&
2621	Actions.isCurrentClassName(II: *Id, S: getCurScope(), SS: &SS)) {
2622	// We have parsed a constructor name.
2623	ParsedType Ty = Actions.getConstructorName(II: *Id, NameLoc: IdLoc, S: getCurScope(), SS,
2624	EnteringContext);
2625	if (!Ty)
2626	return true;
2627	Result.setConstructorName(ClassType: Ty, ClassNameLoc: IdLoc, EndLoc: IdLoc);
2628	} else if (getLangOpts().CPlusPlus17 && AllowDeductionGuide &&
2629	SS.isEmpty() &&
2630	Actions.isDeductionGuideName(S: getCurScope(), Name: *Id, NameLoc: IdLoc, SS,
2631	Template: &TemplateName)) {
2632	// We have parsed a template-name naming a deduction guide.
2633	Result.setDeductionGuideName(Template: TemplateName, TemplateLoc: IdLoc);
2634	} else {
2635	// We have parsed an identifier.
2636	Result.setIdentifier(Id, IdLoc);
2637	}
2638
2639	// If the next token is a '<', we may have a template.
2640	TemplateTy Template;
2641	if (Tok.is(K: tok::less))
2642	return ParseUnqualifiedIdTemplateId(
2643	SS, ObjectType, ObjectHadErrors,
2644	TemplateKWLoc: TemplateKWLoc ? *TemplateKWLoc : SourceLocation(), Name: Id, NameLoc: IdLoc,
2645	EnteringContext, Id&: Result, AssumeTemplateId: TemplateSpecified);
2646
2647	if (TemplateSpecified) {
2648	TemplateNameKind TNK =
2649	Actions.ActOnTemplateName(S: getCurScope(), SS, TemplateKWLoc: *TemplateKWLoc, Name: Result,
2650	ObjectType, EnteringContext, Template,
2651	/*AllowInjectedClassName=*/true);
2652	if (TNK == TNK_Non_template)
2653	return true;
2654
2655	// C++2c [tem.names]p6
2656	// A name prefixed by the keyword template shall be followed by a template
2657	// argument list or refer to a class template or an alias template.
2658	if ((TNK == TNK_Function_template || TNK == TNK_Dependent_template_name ||
2659	TNK == TNK_Var_template) &&
2660	!Tok.is(tok::less))
2661	Diag(IdLoc, diag::missing_template_arg_list_after_template_kw);
2662	}
2663	return false;
2664	}
2665
2666	// unqualified-id:
2667	// template-id (already parsed and annotated)
2668	if (Tok.is(K: tok::annot_template_id)) {
2669	TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(tok: Tok);
2670
2671	// FIXME: Consider passing invalid template-ids on to callers; they may
2672	// be able to recover better than we can.
2673	if (TemplateId->isInvalid()) {
2674	ConsumeAnnotationToken();
2675	return true;
2676	}
2677
2678	// If the template-name names the current class, then this is a constructor
2679	if (AllowConstructorName && TemplateId->Name &&
2680	Actions.isCurrentClassName(II: *TemplateId->Name, S: getCurScope(), SS: &SS)) {
2681	if (SS.isSet()) {
2682	// C++ [class.qual]p2 specifies that a qualified template-name
2683	// is taken as the constructor name where a constructor can be
2684	// declared. Thus, the template arguments are extraneous, so
2685	// complain about them and remove them entirely.
2686	Diag(TemplateId->TemplateNameLoc,
2687	diag::err_out_of_line_constructor_template_id)
2688	<< TemplateId->Name
2689	<< FixItHint::CreateRemoval(
2690	SourceRange(TemplateId->LAngleLoc, TemplateId->RAngleLoc));
2691	ParsedType Ty = Actions.getConstructorName(
2692	II: *TemplateId->Name, NameLoc: TemplateId->TemplateNameLoc, S: getCurScope(), SS,
2693	EnteringContext);
2694	if (!Ty)
2695	return true;
2696	Result.setConstructorName(ClassType: Ty, ClassNameLoc: TemplateId->TemplateNameLoc,
2697	EndLoc: TemplateId->RAngleLoc);
2698	ConsumeAnnotationToken();
2699	return false;
2700	}
2701
2702	Result.setConstructorTemplateId(TemplateId);
2703	ConsumeAnnotationToken();
2704	return false;
2705	}
2706
2707	// We have already parsed a template-id; consume the annotation token as
2708	// our unqualified-id.
2709	Result.setTemplateId(TemplateId);
2710	SourceLocation TemplateLoc = TemplateId->TemplateKWLoc;
2711	if (TemplateLoc.isValid()) {
2712	if (TemplateKWLoc && (ObjectType || SS.isSet()))
2713	*TemplateKWLoc = TemplateLoc;
2714	else
2715	Diag(TemplateLoc, diag::err_unexpected_template_in_unqualified_id)
2716	<< FixItHint::CreateRemoval(TemplateLoc);
2717	}
2718	ConsumeAnnotationToken();
2719	return false;
2720	}
2721
2722	// unqualified-id:
2723	// operator-function-id
2724	// conversion-function-id
2725	if (Tok.is(K: tok::kw_operator)) {
2726	if (ParseUnqualifiedIdOperator(SS, EnteringContext, ObjectType, Result))
2727	return true;
2728
2729	// If we have an operator-function-id or a literal-operator-id and the next
2730	// token is a '<', we may have a
2731	//
2732	// template-id:
2733	// operator-function-id < template-argument-list[opt] >
2734	TemplateTy Template;
2735	if ((Result.getKind() == UnqualifiedIdKind::IK_OperatorFunctionId ||
2736	Result.getKind() == UnqualifiedIdKind::IK_LiteralOperatorId) &&
2737	Tok.is(K: tok::less))
2738	return ParseUnqualifiedIdTemplateId(
2739	SS, ObjectType, ObjectHadErrors,
2740	TemplateKWLoc: TemplateKWLoc ? *TemplateKWLoc : SourceLocation(), Name: nullptr,
2741	NameLoc: SourceLocation(), EnteringContext, Id&: Result, AssumeTemplateId: TemplateSpecified);
2742	else if (TemplateSpecified &&
2743	Actions.ActOnTemplateName(
2744	S: getCurScope(), SS, TemplateKWLoc: *TemplateKWLoc, Name: Result, ObjectType,
2745	EnteringContext, Template,
2746	/*AllowInjectedClassName*/ true) == TNK_Non_template)
2747	return true;
2748
2749	return false;
2750	}
2751
2752	if (getLangOpts().CPlusPlus &&
2753	(AllowDestructorName || SS.isSet()) && Tok.is(K: tok::tilde)) {
2754	// C++ [expr.unary.op]p10:
2755	// There is an ambiguity in the unary-expression ~X(), where X is a
2756	// class-name. The ambiguity is resolved in favor of treating ~ as a
2757	// unary complement rather than treating ~X as referring to a destructor.
2758
2759	// Parse the '~'.
2760	SourceLocation TildeLoc = ConsumeToken();
2761
2762	if (TemplateSpecified) {
2763	// C++ [temp.names]p3:
2764	// A name prefixed by the keyword template shall be a template-id [...]
2765	//
2766	// A template-id cannot begin with a '~' token. This would never work
2767	// anyway: x.~A<int>() would specify that the destructor is a template,
2768	// not that 'A' is a template.
2769	//
2770	// FIXME: Suggest replacing the attempted destructor name with a correct
2771	// destructor name and recover. (This is not trivial if this would become
2772	// a pseudo-destructor name).
2773	Diag(*TemplateKWLoc, diag::err_unexpected_template_in_destructor_name)
2774	<< Tok.getLocation();
2775	return true;
2776	}
2777
2778	if (SS.isEmpty() && Tok.is(K: tok::kw_decltype)) {
2779	DeclSpec DS(AttrFactory);
2780	SourceLocation EndLoc = ParseDecltypeSpecifier(DS);
2781	if (ParsedType Type =
2782	Actions.getDestructorTypeForDecltype(DS, ObjectType)) {
2783	Result.setDestructorName(TildeLoc, ClassType: Type, EndLoc);
2784	return false;
2785	}
2786	return true;
2787	}
2788
2789	// Parse the class-name.
2790	if (Tok.isNot(K: tok::identifier)) {
2791	Diag(Tok, diag::err_destructor_tilde_identifier);
2792	return true;
2793	}
2794
2795	// If the user wrote ~T::T, correct it to T::~T.
2796	DeclaratorScopeObj DeclScopeObj(*this, SS);
2797	if (NextToken().is(K: tok::coloncolon)) {
2798	// Don't let ParseOptionalCXXScopeSpecifier() "correct"
2799	// `int A; struct { ~A::A(); };` to `int A; struct { ~A:A(); };`,
2800	// it will confuse this recovery logic.
2801	ColonProtectionRAIIObject ColonRAII(*this, false);
2802
2803	if (SS.isSet()) {
2804	AnnotateScopeToken(SS, /*NewAnnotation*/IsNewAnnotation: true);
2805	SS.clear();
2806	}
2807	if (ParseOptionalCXXScopeSpecifier(SS, ObjectType, ObjectHadErrors,
2808	EnteringContext))
2809	return true;
2810	if (SS.isNotEmpty())
2811	ObjectType = nullptr;
2812	if (Tok.isNot(K: tok::identifier) || NextToken().is(K: tok::coloncolon) ||
2813	!SS.isSet()) {
2814	Diag(TildeLoc, diag::err_destructor_tilde_scope);
2815	return true;
2816	}
2817
2818	// Recover as if the tilde had been written before the identifier.
2819	Diag(TildeLoc, diag::err_destructor_tilde_scope)
2820	<< FixItHint::CreateRemoval(TildeLoc)
2821	<< FixItHint::CreateInsertion(Tok.getLocation(), "~");
2822
2823	// Temporarily enter the scope for the rest of this function.
2824	if (Actions.ShouldEnterDeclaratorScope(S: getCurScope(), SS))
2825	DeclScopeObj.EnterDeclaratorScope();
2826	}
2827
2828	// Parse the class-name (or template-name in a simple-template-id).
2829	IdentifierInfo *ClassName = Tok.getIdentifierInfo();
2830	SourceLocation ClassNameLoc = ConsumeToken();
2831
2832	if (Tok.is(K: tok::less)) {
2833	Result.setDestructorName(TildeLoc, ClassType: nullptr, EndLoc: ClassNameLoc);
2834	return ParseUnqualifiedIdTemplateId(
2835	SS, ObjectType, ObjectHadErrors,
2836	TemplateKWLoc: TemplateKWLoc ? *TemplateKWLoc : SourceLocation(), Name: ClassName,
2837	NameLoc: ClassNameLoc, EnteringContext, Id&: Result, AssumeTemplateId: TemplateSpecified);
2838	}
2839
2840	// Note that this is a destructor name.
2841	ParsedType Ty =
2842	Actions.getDestructorName(II: *ClassName, NameLoc: ClassNameLoc, S: getCurScope(), SS,
2843	ObjectType, EnteringContext);
2844	if (!Ty)
2845	return true;
2846
2847	Result.setDestructorName(TildeLoc, ClassType: Ty, EndLoc: ClassNameLoc);
2848	return false;
2849	}
2850
2851	switch (Tok.getKind()) {
2852	#define TRANSFORM_TYPE_TRAIT_DEF(_, Trait) case tok::kw___##Trait:
2853	#include "clang/Basic/TransformTypeTraits.def"
2854	if (!NextToken().is(K: tok::l_paren)) {
2855	Tok.setKind(tok::identifier);
2856	Diag(Tok, diag::ext_keyword_as_ident)
2857	<< Tok.getIdentifierInfo()->getName() << 0;
2858	goto ParseIdentifier;
2859	}
2860	[[fallthrough]];
2861	default:
2862	Diag(Tok, diag::err_expected_unqualified_id) << getLangOpts().CPlusPlus;
2863	return true;
2864	}
2865	}
2866
2867	ExprResult
2868	Parser::ParseCXXNewExpression(bool UseGlobal, SourceLocation Start) {
2869	assert(Tok.is(tok::kw_new) && "expected 'new' token");
2870	ConsumeToken(); // Consume 'new'
2871
2872	// A '(' now can be a new-placement or the '(' wrapping the type-id in the
2873	// second form of new-expression. It can't be a new-type-id.
2874
2875	ExprVector PlacementArgs;
2876	SourceLocation PlacementLParen, PlacementRParen;
2877
2878	SourceRange TypeIdParens;
2879	DeclSpec DS(AttrFactory);
2880	Declarator DeclaratorInfo(DS, ParsedAttributesView::none(),
2881	DeclaratorContext::CXXNew);
2882	if (Tok.is(K: tok::l_paren)) {
2883	// If it turns out to be a placement, we change the type location.
2884	BalancedDelimiterTracker T(*this, tok::l_paren);
2885	T.consumeOpen();
2886	PlacementLParen = T.getOpenLocation();
2887	if (ParseExpressionListOrTypeId(Exprs&: PlacementArgs, D&: DeclaratorInfo)) {
2888	SkipUntil(T: tok::semi, Flags: StopAtSemi | StopBeforeMatch);
2889	return ExprError();
2890	}
2891
2892	T.consumeClose();
2893	PlacementRParen = T.getCloseLocation();
2894	if (PlacementRParen.isInvalid()) {
2895	SkipUntil(T: tok::semi, Flags: StopAtSemi | StopBeforeMatch);
2896	return ExprError();
2897	}
2898
2899	if (PlacementArgs.empty()) {
2900	// Reset the placement locations. There was no placement.
2901	TypeIdParens = T.getRange();
2902	PlacementLParen = PlacementRParen = SourceLocation();
2903	} else {
2904	// We still need the type.
2905	if (Tok.is(K: tok::l_paren)) {
2906	BalancedDelimiterTracker T(*this, tok::l_paren);
2907	T.consumeOpen();
2908	MaybeParseGNUAttributes(D&: DeclaratorInfo);
2909	ParseSpecifierQualifierList(DS);
2910	DeclaratorInfo.SetSourceRange(DS.getSourceRange());
2911	ParseDeclarator(D&: DeclaratorInfo);
2912	T.consumeClose();
2913	TypeIdParens = T.getRange();
2914	} else {
2915	MaybeParseGNUAttributes(D&: DeclaratorInfo);
2916	if (ParseCXXTypeSpecifierSeq(DS))
2917	DeclaratorInfo.setInvalidType(true);
2918	else {
2919	DeclaratorInfo.SetSourceRange(DS.getSourceRange());
2920	ParseDeclaratorInternal(D&: DeclaratorInfo,
2921	DirectDeclParser: &Parser::ParseDirectNewDeclarator);
2922	}
2923	}
2924	}
2925	} else {
2926	// A new-type-id is a simplified type-id, where essentially the
2927	// direct-declarator is replaced by a direct-new-declarator.
2928	MaybeParseGNUAttributes(D&: DeclaratorInfo);
2929	if (ParseCXXTypeSpecifierSeq(DS, Context: DeclaratorContext::CXXNew))
2930	DeclaratorInfo.setInvalidType(true);
2931	else {
2932	DeclaratorInfo.SetSourceRange(DS.getSourceRange());
2933	ParseDeclaratorInternal(D&: DeclaratorInfo,
2934	DirectDeclParser: &Parser::ParseDirectNewDeclarator);
2935	}
2936	}
2937	if (DeclaratorInfo.isInvalidType()) {
2938	SkipUntil(T: tok::semi, Flags: StopAtSemi | StopBeforeMatch);
2939	return ExprError();
2940	}
2941
2942	ExprResult Initializer;
2943
2944	if (Tok.is(K: tok::l_paren)) {
2945	SourceLocation ConstructorLParen, ConstructorRParen;
2946	ExprVector ConstructorArgs;
2947	BalancedDelimiterTracker T(*this, tok::l_paren);
2948	T.consumeOpen();
2949	ConstructorLParen = T.getOpenLocation();
2950	if (Tok.isNot(K: tok::r_paren)) {
2951	auto RunSignatureHelp = [&]() {
2952	ParsedType TypeRep = Actions.ActOnTypeName(D&: DeclaratorInfo).get();
2953	QualType PreferredType;
2954	// ActOnTypeName might adjust DeclaratorInfo and return a null type even
2955	// the passing DeclaratorInfo is valid, e.g. running SignatureHelp on
2956	// `new decltype(invalid) (^)`.
2957	if (TypeRep)
2958	PreferredType =
2959	Actions.CodeCompletion().ProduceConstructorSignatureHelp(
2960	Type: TypeRep.get()->getCanonicalTypeInternal(),
2961	Loc: DeclaratorInfo.getEndLoc(), Args: ConstructorArgs,
2962	OpenParLoc: ConstructorLParen,
2963	/*Braced=*/false);
2964	CalledSignatureHelp = true;
2965	return PreferredType;
2966	};
2967	if (ParseExpressionList(Exprs&: ConstructorArgs, ExpressionStarts: [&] {
2968	PreferredType.enterFunctionArgument(Tok.getLocation(),
2969	RunSignatureHelp);
2970	})) {
2971	if (PP.isCodeCompletionReached() && !CalledSignatureHelp)
2972	RunSignatureHelp();
2973	SkipUntil(T: tok::semi, Flags: StopAtSemi | StopBeforeMatch);
2974	return ExprError();
2975	}
2976	}
2977	T.consumeClose();
2978	ConstructorRParen = T.getCloseLocation();
2979	if (ConstructorRParen.isInvalid()) {
2980	SkipUntil(T: tok::semi, Flags: StopAtSemi | StopBeforeMatch);
2981	return ExprError();
2982	}
2983	Initializer = Actions.ActOnParenListExpr(L: ConstructorLParen,
2984	R: ConstructorRParen,
2985	Val: ConstructorArgs);
2986	} else if (Tok.is(K: tok::l_brace) && getLangOpts().CPlusPlus11) {
2987	Diag(Tok.getLocation(),
2988	diag::warn_cxx98_compat_generalized_initializer_lists);
2989	Initializer = ParseBraceInitializer();
2990	}
2991	if (Initializer.isInvalid())
2992	return Initializer;
2993
2994	return Actions.ActOnCXXNew(StartLoc: Start, UseGlobal, PlacementLParen,
2995	PlacementArgs, PlacementRParen,
2996	TypeIdParens, D&: DeclaratorInfo, Initializer: Initializer.get());
2997	}
2998
2999	void Parser::ParseDirectNewDeclarator(Declarator &D) {
3000	// Parse the array dimensions.
3001	bool First = true;
3002	while (Tok.is(K: tok::l_square)) {
3003	// An array-size expression can't start with a lambda.
3004	if (CheckProhibitedCXX11Attribute())
3005	continue;
3006
3007	BalancedDelimiterTracker T(*this, tok::l_square);
3008	T.consumeOpen();
3009
3010	ExprResult Size =
3011	First ? (Tok.is(K: tok::r_square) ? ExprResult() : ParseExpression())
3012	: ParseConstantExpression();
3013	if (Size.isInvalid()) {
3014	// Recover
3015	SkipUntil(T: tok::r_square, Flags: StopAtSemi);
3016	return;
3017	}
3018	First = false;
3019
3020	T.consumeClose();
3021
3022	// Attributes here appertain to the array type. C++11 [expr.new]p5.
3023	ParsedAttributes Attrs(AttrFactory);
3024	MaybeParseCXX11Attributes(Attrs);
3025
3026	D.AddTypeInfo(TI: DeclaratorChunk::getArray(TypeQuals: 0,
3027	/*isStatic=*/false, /*isStar=*/false,
3028	NumElts: Size.get(), LBLoc: T.getOpenLocation(),
3029	RBLoc: T.getCloseLocation()),
3030	attrs: std::move(Attrs), EndLoc: T.getCloseLocation());
3031
3032	if (T.getCloseLocation().isInvalid())
3033	return;
3034	}
3035	}
3036
3037	bool Parser::ParseExpressionListOrTypeId(
3038	SmallVectorImpl<Expr*> &PlacementArgs,
3039	Declarator &D) {
3040	// The '(' was already consumed.
3041	if (isTypeIdInParens()) {
3042	ParseSpecifierQualifierList(DS&: D.getMutableDeclSpec());
3043	D.SetSourceRange(D.getDeclSpec().getSourceRange());
3044	ParseDeclarator(D);
3045	return D.isInvalidType();
3046	}
3047
3048	// It's not a type, it has to be an expression list.
3049	return ParseExpressionList(Exprs&: PlacementArgs);
3050	}
3051
3052	ExprResult
3053	Parser::ParseCXXDeleteExpression(bool UseGlobal, SourceLocation Start) {
3054	assert(Tok.is(tok::kw_delete) && "Expected 'delete' keyword");
3055	ConsumeToken(); // Consume 'delete'
3056
3057	// Array delete?
3058	bool ArrayDelete = false;
3059	if (Tok.is(K: tok::l_square) && NextToken().is(K: tok::r_square)) {
3060	// C++11 [expr.delete]p1:
3061	// Whenever the delete keyword is followed by empty square brackets, it
3062	// shall be interpreted as [array delete].
3063	// [Footnote: A lambda expression with a lambda-introducer that consists
3064	// of empty square brackets can follow the delete keyword if
3065	// the lambda expression is enclosed in parentheses.]
3066
3067	const Token Next = GetLookAheadToken(N: 2);
3068
3069	// Basic lookahead to check if we have a lambda expression.
3070	if (Next.isOneOf(K1: tok::l_brace, K2: tok::less) ||
3071	(Next.is(K: tok::l_paren) &&
3072	(GetLookAheadToken(N: 3).is(K: tok::r_paren) ||
3073	(GetLookAheadToken(N: 3).is(K: tok::identifier) &&
3074	GetLookAheadToken(N: 4).is(K: tok::identifier))))) {
3075	TentativeParsingAction TPA(*this);
3076	SourceLocation LSquareLoc = Tok.getLocation();
3077	SourceLocation RSquareLoc = NextToken().getLocation();
3078
3079	// SkipUntil can't skip pairs of </*...*/>; don't emit a FixIt in this
3080	// case.
3081	SkipUntil(Toks: {tok::l_brace, tok::less}, Flags: StopBeforeMatch);
3082	SourceLocation RBraceLoc;
3083	bool EmitFixIt = false;
3084	if (Tok.is(K: tok::l_brace)) {
3085	ConsumeBrace();
3086	SkipUntil(T: tok::r_brace, Flags: StopBeforeMatch);
3087	RBraceLoc = Tok.getLocation();
3088	EmitFixIt = true;
3089	}
3090
3091	TPA.Revert();
3092
3093	if (EmitFixIt)
3094	Diag(Start, diag::err_lambda_after_delete)
3095	<< SourceRange(Start, RSquareLoc)
3096	<< FixItHint::CreateInsertion(LSquareLoc, "(")
3097	<< FixItHint::CreateInsertion(
3098	Lexer::getLocForEndOfToken(
3099	RBraceLoc, 0, Actions.getSourceManager(), getLangOpts()),
3100	")");
3101	else
3102	Diag(Start, diag::err_lambda_after_delete)
3103	<< SourceRange(Start, RSquareLoc);
3104
3105	// Warn that the non-capturing lambda isn't surrounded by parentheses
3106	// to disambiguate it from 'delete[]'.
3107	ExprResult Lambda = ParseLambdaExpression();
3108	if (Lambda.isInvalid())
3109	return ExprError();
3110
3111	// Evaluate any postfix expressions used on the lambda.
3112	Lambda = ParsePostfixExpressionSuffix(LHS: Lambda);
3113	if (Lambda.isInvalid())
3114	return ExprError();
3115	return Actions.ActOnCXXDelete(StartLoc: Start, UseGlobal, /*ArrayForm=*/false,
3116	Operand: Lambda.get());
3117	}
3118
3119	ArrayDelete = true;
3120	BalancedDelimiterTracker T(*this, tok::l_square);
3121
3122	T.consumeOpen();
3123	T.consumeClose();
3124	if (T.getCloseLocation().isInvalid())
3125	return ExprError();
3126	}
3127
3128	ExprResult Operand(ParseCastExpression(ParseKind: CastParseKind::AnyCastExpr));
3129	if (Operand.isInvalid())
3130	return Operand;
3131
3132	return Actions.ActOnCXXDelete(StartLoc: Start, UseGlobal, ArrayForm: ArrayDelete, Operand: Operand.get());
3133	}
3134
3135	ExprResult Parser::ParseRequiresExpression() {
3136	assert(Tok.is(tok::kw_requires) && "Expected 'requires' keyword");
3137	SourceLocation RequiresKWLoc = ConsumeToken(); // Consume 'requires'
3138
3139	llvm::SmallVector<ParmVarDecl *, 2> LocalParameterDecls;
3140	BalancedDelimiterTracker Parens(*this, tok::l_paren);
3141	if (Tok.is(K: tok::l_paren)) {
3142	// requirement parameter list is present.
3143	ParseScope LocalParametersScope(this, Scope::FunctionPrototypeScope |
3144	Scope::DeclScope);
3145	Parens.consumeOpen();
3146	if (!Tok.is(K: tok::r_paren)) {
3147	ParsedAttributes FirstArgAttrs(getAttrFactory());
3148	SourceLocation EllipsisLoc;
3149	llvm::SmallVector<DeclaratorChunk::ParamInfo, 2> LocalParameters;
3150	ParseParameterDeclarationClause(DeclaratorContext: DeclaratorContext::RequiresExpr,
3151	attrs&: FirstArgAttrs, ParamInfo&: LocalParameters,
3152	EllipsisLoc);
3153	if (EllipsisLoc.isValid())
3154	Diag(EllipsisLoc, diag::err_requires_expr_parameter_list_ellipsis);
3155	for (auto &ParamInfo : LocalParameters)
3156	LocalParameterDecls.push_back(Elt: cast<ParmVarDecl>(Val: ParamInfo.Param));
3157	}
3158	Parens.consumeClose();
3159	}
3160
3161	BalancedDelimiterTracker Braces(*this, tok::l_brace);
3162	if (Braces.expectAndConsume())
3163	return ExprError();
3164
3165	// Start of requirement list
3166	llvm::SmallVector<concepts::Requirement *, 2> Requirements;
3167
3168	// C++2a [expr.prim.req]p2
3169	// Expressions appearing within a requirement-body are unevaluated operands.
3170	EnterExpressionEvaluationContext Ctx(
3171	Actions, Sema::ExpressionEvaluationContext::Unevaluated);
3172
3173	ParseScope BodyScope(this, Scope::DeclScope);
3174	// Create a separate diagnostic pool for RequiresExprBodyDecl.
3175	// Dependent diagnostics are attached to this Decl and non-depenedent
3176	// diagnostics are surfaced after this parse.
3177	ParsingDeclRAIIObject ParsingBodyDecl(*this, ParsingDeclRAIIObject::NoParent);
3178	RequiresExprBodyDecl *Body = Actions.ActOnStartRequiresExpr(
3179	RequiresKWLoc, LocalParameters: LocalParameterDecls, BodyScope: getCurScope());
3180
3181	if (Tok.is(K: tok::r_brace)) {
3182	// Grammar does not allow an empty body.
3183	// requirement-body:
3184	// { requirement-seq }
3185	// requirement-seq:
3186	// requirement
3187	// requirement-seq requirement
3188	Diag(Tok, diag::err_empty_requires_expr);
3189	// Continue anyway and produce a requires expr with no requirements.
3190	} else {
3191	while (!Tok.is(K: tok::r_brace)) {
3192	switch (Tok.getKind()) {
3193	case tok::l_brace: {
3194	// Compound requirement
3195	// C++ [expr.prim.req.compound]
3196	// compound-requirement:
3197	// '{' expression '}' 'noexcept'[opt]
3198	// return-type-requirement[opt] ';'
3199	// return-type-requirement:
3200	// trailing-return-type
3201	// '->' cv-qualifier-seq[opt] constrained-parameter
3202	// cv-qualifier-seq[opt] abstract-declarator[opt]
3203	BalancedDelimiterTracker ExprBraces(*this, tok::l_brace);
3204	ExprBraces.consumeOpen();
3205	ExprResult Expression =
3206	Actions.CorrectDelayedTyposInExpr(ER: ParseExpression());
3207	if (!Expression.isUsable()) {
3208	ExprBraces.skipToEnd();
3209	SkipUntil(T1: tok::semi, T2: tok::r_brace, Flags: SkipUntilFlags::StopBeforeMatch);
3210	break;
3211	}
3212	// If there's an error consuming the closing bracket, consumeClose()
3213	// will handle skipping to the nearest recovery point for us.
3214	if (ExprBraces.consumeClose())
3215	break;
3216
3217	concepts::Requirement *Req = nullptr;
3218	SourceLocation NoexceptLoc;
3219	TryConsumeToken(Expected: tok::kw_noexcept, Loc&: NoexceptLoc);
3220	if (Tok.is(K: tok::semi)) {
3221	Req = Actions.ActOnCompoundRequirement(E: Expression.get(), NoexceptLoc);
3222	if (Req)
3223	Requirements.push_back(Elt: Req);
3224	break;
3225	}
3226	if (!TryConsumeToken(tok::arrow))
3227	// User probably forgot the arrow, remind them and try to continue.
3228	Diag(Tok, diag::err_requires_expr_missing_arrow)
3229	<< FixItHint::CreateInsertion(Tok.getLocation(), "->");
3230	// Try to parse a 'type-constraint'
3231	if (TryAnnotateTypeConstraint()) {
3232	SkipUntil(T1: tok::semi, T2: tok::r_brace, Flags: SkipUntilFlags::StopBeforeMatch);
3233	break;
3234	}
3235	if (!isTypeConstraintAnnotation()) {
3236	Diag(Tok, diag::err_requires_expr_expected_type_constraint);
3237	SkipUntil(T1: tok::semi, T2: tok::r_brace, Flags: SkipUntilFlags::StopBeforeMatch);
3238	break;
3239	}
3240	CXXScopeSpec SS;
3241	if (Tok.is(K: tok::annot_cxxscope)) {
3242	Actions.RestoreNestedNameSpecifierAnnotation(Annotation: Tok.getAnnotationValue(),
3243	AnnotationRange: Tok.getAnnotationRange(),
3244	SS);
3245	ConsumeAnnotationToken();
3246	}
3247
3248	Req = Actions.ActOnCompoundRequirement(
3249	E: Expression.get(), NoexceptLoc, SS, TypeConstraint: takeTemplateIdAnnotation(tok: Tok),
3250	Depth: TemplateParameterDepth);
3251	ConsumeAnnotationToken();
3252	if (Req)
3253	Requirements.push_back(Elt: Req);
3254	break;
3255	}
3256	default: {
3257	bool PossibleRequiresExprInSimpleRequirement = false;
3258	if (Tok.is(K: tok::kw_requires)) {
3259	auto IsNestedRequirement = [&] {
3260	RevertingTentativeParsingAction TPA(*this);
3261	ConsumeToken(); // 'requires'
3262	if (Tok.is(K: tok::l_brace))
3263	// This is a requires expression
3264	// requires (T t) {
3265	// requires { t++; };
3266	// ... ^
3267	// }
3268	return false;
3269	if (Tok.is(K: tok::l_paren)) {
3270	// This might be the parameter list of a requires expression
3271	ConsumeParen();
3272	auto Res = TryParseParameterDeclarationClause();
3273	if (Res != TPResult::False) {
3274	// Skip to the closing parenthesis
3275	unsigned Depth = 1;
3276	while (Depth != 0) {
3277	bool FoundParen = SkipUntil(T1: tok::l_paren, T2: tok::r_paren,
3278	Flags: SkipUntilFlags::StopBeforeMatch);
3279	if (!FoundParen)
3280	break;
3281	if (Tok.is(K: tok::l_paren))
3282	Depth++;
3283	else if (Tok.is(K: tok::r_paren))
3284	Depth--;
3285	ConsumeAnyToken();
3286	}
3287	// requires (T t) {
3288	// requires () ?
3289	// ... ^
3290	// - OR -
3291	// requires (int x) ?
3292	// ... ^
3293	// }
3294	if (Tok.is(K: tok::l_brace))
3295	// requires (...) {
3296	// ^ - a requires expression as a
3297	// simple-requirement.
3298	return false;
3299	}
3300	}
3301	return true;
3302	};
3303	if (IsNestedRequirement()) {
3304	ConsumeToken();
3305	// Nested requirement
3306	// C++ [expr.prim.req.nested]
3307	// nested-requirement:
3308	// 'requires' constraint-expression ';'
3309	ExprResult ConstraintExpr =
3310	Actions.CorrectDelayedTyposInExpr(ER: ParseConstraintExpression());
3311	if (ConstraintExpr.isInvalid() || !ConstraintExpr.isUsable()) {
3312	SkipUntil(T1: tok::semi, T2: tok::r_brace,
3313	Flags: SkipUntilFlags::StopBeforeMatch);
3314	break;
3315	}
3316	if (auto *Req =
3317	Actions.ActOnNestedRequirement(Constraint: ConstraintExpr.get()))
3318	Requirements.push_back(Elt: Req);
3319	else {
3320	SkipUntil(T1: tok::semi, T2: tok::r_brace,
3321	Flags: SkipUntilFlags::StopBeforeMatch);
3322	break;
3323	}
3324	break;
3325	} else
3326	PossibleRequiresExprInSimpleRequirement = true;
3327	} else if (Tok.is(K: tok::kw_typename)) {
3328	// This might be 'typename T::value_type;' (a type requirement) or
3329	// 'typename T::value_type{};' (a simple requirement).
3330	TentativeParsingAction TPA(*this);
3331
3332	// We need to consume the typename to allow 'requires { typename a; }'
3333	SourceLocation TypenameKWLoc = ConsumeToken();
3334	if (TryAnnotateOptionalCXXScopeToken()) {
3335	TPA.Commit();
3336	SkipUntil(T1: tok::semi, T2: tok::r_brace, Flags: SkipUntilFlags::StopBeforeMatch);
3337	break;
3338	}
3339	CXXScopeSpec SS;
3340	if (Tok.is(K: tok::annot_cxxscope)) {
3341	Actions.RestoreNestedNameSpecifierAnnotation(
3342	Annotation: Tok.getAnnotationValue(), AnnotationRange: Tok.getAnnotationRange(), SS);
3343	ConsumeAnnotationToken();
3344	}
3345
3346	if (Tok.isOneOf(K1: tok::identifier, K2: tok::annot_template_id) &&
3347	!NextToken().isOneOf(K1: tok::l_brace, K2: tok::l_paren)) {
3348	TPA.Commit();
3349	SourceLocation NameLoc = Tok.getLocation();
3350	IdentifierInfo *II = nullptr;
3351	TemplateIdAnnotation *TemplateId = nullptr;
3352	if (Tok.is(K: tok::identifier)) {
3353	II = Tok.getIdentifierInfo();
3354	ConsumeToken();
3355	} else {
3356	TemplateId = takeTemplateIdAnnotation(tok: Tok);
3357	ConsumeAnnotationToken();
3358	if (TemplateId->isInvalid())
3359	break;
3360	}
3361
3362	if (auto *Req = Actions.ActOnTypeRequirement(TypenameKWLoc, SS,
3363	NameLoc, TypeName: II,
3364	TemplateId)) {
3365	Requirements.push_back(Elt: Req);
3366	}
3367	break;
3368	}
3369	TPA.Revert();
3370	}
3371	// Simple requirement
3372	// C++ [expr.prim.req.simple]
3373	// simple-requirement:
3374	// expression ';'
3375	SourceLocation StartLoc = Tok.getLocation();
3376	ExprResult Expression =
3377	Actions.CorrectDelayedTyposInExpr(ER: ParseExpression());
3378	if (!Expression.isUsable()) {
3379	SkipUntil(T1: tok::semi, T2: tok::r_brace, Flags: SkipUntilFlags::StopBeforeMatch);
3380	break;
3381	}
3382	if (!Expression.isInvalid() && PossibleRequiresExprInSimpleRequirement)
3383	Diag(StartLoc, diag::err_requires_expr_in_simple_requirement)
3384	<< FixItHint::CreateInsertion(StartLoc, "requires");
3385	if (auto *Req = Actions.ActOnSimpleRequirement(E: Expression.get()))
3386	Requirements.push_back(Elt: Req);
3387	else {
3388	SkipUntil(T1: tok::semi, T2: tok::r_brace, Flags: SkipUntilFlags::StopBeforeMatch);
3389	break;
3390	}
3391	// User may have tried to put some compound requirement stuff here
3392	if (Tok.is(K: tok::kw_noexcept)) {
3393	Diag(Tok, diag::err_requires_expr_simple_requirement_noexcept)
3394	<< FixItHint::CreateInsertion(StartLoc, "{")
3395	<< FixItHint::CreateInsertion(Tok.getLocation(), "}");
3396	SkipUntil(T1: tok::semi, T2: tok::r_brace, Flags: SkipUntilFlags::StopBeforeMatch);
3397	break;
3398	}
3399	break;
3400	}
3401	}
3402	if (ExpectAndConsumeSemi(diag::err_expected_semi_requirement)) {
3403	SkipUntil(T1: tok::semi, T2: tok::r_brace, Flags: SkipUntilFlags::StopBeforeMatch);
3404	TryConsumeToken(Expected: tok::semi);
3405	break;
3406	}
3407	}
3408	if (Requirements.empty()) {
3409	// Don't emit an empty requires expr here to avoid confusing the user with
3410	// other diagnostics quoting an empty requires expression they never
3411	// wrote.
3412	Braces.consumeClose();
3413	Actions.ActOnFinishRequiresExpr();
3414	return ExprError();
3415	}
3416	}
3417	Braces.consumeClose();
3418	Actions.ActOnFinishRequiresExpr();
3419	ParsingBodyDecl.complete(Body);
3420	return Actions.ActOnRequiresExpr(
3421	RequiresKWLoc, Body, LParenLoc: Parens.getOpenLocation(), LocalParameters: LocalParameterDecls,
3422	RParenLoc: Parens.getCloseLocation(), Requirements, ClosingBraceLoc: Braces.getCloseLocation());
3423	}
3424
3425	static TypeTrait TypeTraitFromTokKind(tok::TokenKind kind) {
3426	switch (kind) {
3427	default: llvm_unreachable("Not a known type trait");
3428	#define TYPE_TRAIT_1(Spelling, Name, Key) \
3429	case tok::kw_ ## Spelling: return UTT_ ## Name;
3430	#define TYPE_TRAIT_2(Spelling, Name, Key) \
3431	case tok::kw_ ## Spelling: return BTT_ ## Name;
3432	#include "clang/Basic/TokenKinds.def"
3433	#define TYPE_TRAIT_N(Spelling, Name, Key) \
3434	case tok::kw_ ## Spelling: return TT_ ## Name;
3435	#include "clang/Basic/TokenKinds.def"
3436	}
3437	}
3438
3439	static ArrayTypeTrait ArrayTypeTraitFromTokKind(tok::TokenKind kind) {
3440	switch (kind) {
3441	default:
3442	llvm_unreachable("Not a known array type trait");
3443	#define ARRAY_TYPE_TRAIT(Spelling, Name, Key) \
3444	case tok::kw_##Spelling: \
3445	return ATT_##Name;
3446	#include "clang/Basic/TokenKinds.def"
3447	}
3448	}
3449
3450	static ExpressionTrait ExpressionTraitFromTokKind(tok::TokenKind kind) {
3451	switch (kind) {
3452	default:
3453	llvm_unreachable("Not a known unary expression trait.");
3454	#define EXPRESSION_TRAIT(Spelling, Name, Key) \
3455	case tok::kw_##Spelling: \
3456	return ET_##Name;
3457	#include "clang/Basic/TokenKinds.def"
3458	}
3459	}
3460
3461	ExprResult Parser::ParseTypeTrait() {
3462	tok::TokenKind Kind = Tok.getKind();
3463
3464	SourceLocation Loc = ConsumeToken();
3465
3466	BalancedDelimiterTracker Parens(*this, tok::l_paren);
3467	if (Parens.expectAndConsume())
3468	return ExprError();
3469
3470	SmallVector<ParsedType, 2> Args;
3471	do {
3472	// Parse the next type.
3473	TypeResult Ty = ParseTypeName(/*SourceRange=*/Range: nullptr,
3474	Context: getLangOpts().CPlusPlus
3475	? DeclaratorContext::TemplateTypeArg
3476	: DeclaratorContext::TypeName);
3477	if (Ty.isInvalid()) {
3478	Parens.skipToEnd();
3479	return ExprError();
3480	}
3481
3482	// Parse the ellipsis, if present.
3483	if (Tok.is(K: tok::ellipsis)) {
3484	Ty = Actions.ActOnPackExpansion(Type: Ty.get(), EllipsisLoc: ConsumeToken());
3485	if (Ty.isInvalid()) {
3486	Parens.skipToEnd();
3487	return ExprError();
3488	}
3489	}
3490
3491	// Add this type to the list of arguments.
3492	Args.push_back(Elt: Ty.get());
3493	} while (TryConsumeToken(Expected: tok::comma));
3494
3495	if (Parens.consumeClose())
3496	return ExprError();
3497
3498	SourceLocation EndLoc = Parens.getCloseLocation();
3499
3500	return Actions.ActOnTypeTrait(Kind: TypeTraitFromTokKind(kind: Kind), KWLoc: Loc, Args, RParenLoc: EndLoc);
3501	}
3502
3503	ExprResult Parser::ParseArrayTypeTrait() {
3504	ArrayTypeTrait ATT = ArrayTypeTraitFromTokKind(kind: Tok.getKind());
3505	SourceLocation Loc = ConsumeToken();
3506
3507	BalancedDelimiterTracker T(*this, tok::l_paren);
3508	if (T.expectAndConsume())
3509	return ExprError();
3510
3511	TypeResult Ty = ParseTypeName(/*SourceRange=*/Range: nullptr,
3512	Context: DeclaratorContext::TemplateTypeArg);
3513	if (Ty.isInvalid()) {
3514	SkipUntil(T: tok::comma, Flags: StopAtSemi);
3515	SkipUntil(T: tok::r_paren, Flags: StopAtSemi);
3516	return ExprError();
3517	}
3518
3519	switch (ATT) {
3520	case ATT_ArrayRank: {
3521	T.consumeClose();
3522	return Actions.ActOnArrayTypeTrait(ATT, KWLoc: Loc, LhsTy: Ty.get(), DimExpr: nullptr,
3523	RParen: T.getCloseLocation());
3524	}
3525	case ATT_ArrayExtent: {
3526	if (ExpectAndConsume(ExpectedTok: tok::comma)) {
3527	SkipUntil(T: tok::r_paren, Flags: StopAtSemi);
3528	return ExprError();
3529	}
3530
3531	ExprResult DimExpr = ParseExpression();
3532	T.consumeClose();
3533
3534	if (DimExpr.isInvalid())
3535	return ExprError();
3536
3537	return Actions.ActOnArrayTypeTrait(ATT, KWLoc: Loc, LhsTy: Ty.get(), DimExpr: DimExpr.get(),
3538	RParen: T.getCloseLocation());
3539	}
3540	}
3541	llvm_unreachable("Invalid ArrayTypeTrait!");
3542	}
3543
3544	ExprResult Parser::ParseExpressionTrait() {
3545	ExpressionTrait ET = ExpressionTraitFromTokKind(kind: Tok.getKind());
3546	SourceLocation Loc = ConsumeToken();
3547
3548	BalancedDelimiterTracker T(*this, tok::l_paren);
3549	if (T.expectAndConsume())
3550	return ExprError();
3551
3552	ExprResult Expr = ParseExpression();
3553
3554	T.consumeClose();
3555
3556	return Actions.ActOnExpressionTrait(OET: ET, KWLoc: Loc, Queried: Expr.get(),
3557	RParen: T.getCloseLocation());
3558	}
3559
3560	ExprResult
3561	Parser::ParseCXXAmbiguousParenExpression(ParenParseOption &ExprType,
3562	ParsedType &CastTy,
3563	BalancedDelimiterTracker &Tracker,
3564	ColonProtectionRAIIObject &ColonProt) {
3565	assert(getLangOpts().CPlusPlus && "Should only be called for C++!");
3566	assert(ExprType == ParenParseOption::CastExpr &&
3567	"Compound literals are not ambiguous!");
3568	assert(isTypeIdInParens() && "Not a type-id!");
3569
3570	ExprResult Result(true);
3571	CastTy = nullptr;
3572
3573	// We need to disambiguate a very ugly part of the C++ syntax:
3574	//
3575	// (T())x; - type-id
3576	// (T())*x; - type-id
3577	// (T())/x; - expression
3578	// (T()); - expression
3579	//
3580	// The bad news is that we cannot use the specialized tentative parser, since
3581	// it can only verify that the thing inside the parens can be parsed as
3582	// type-id, it is not useful for determining the context past the parens.
3583	//
3584	// The good news is that the parser can disambiguate this part without
3585	// making any unnecessary Action calls.
3586	//
3587	// It uses a scheme similar to parsing inline methods. The parenthesized
3588	// tokens are cached, the context that follows is determined (possibly by
3589	// parsing a cast-expression), and then we re-introduce the cached tokens
3590	// into the token stream and parse them appropriately.
3591
3592	ParenParseOption ParseAs;
3593	CachedTokens Toks;
3594
3595	// Store the tokens of the parentheses. We will parse them after we determine
3596	// the context that follows them.
3597	if (!ConsumeAndStoreUntil(T1: tok::r_paren, Toks)) {
3598	// We didn't find the ')' we expected.
3599	Tracker.consumeClose();
3600	return ExprError();
3601	}
3602
3603	if (Tok.is(K: tok::l_brace)) {
3604	ParseAs = ParenParseOption::CompoundLiteral;
3605	} else {
3606	bool NotCastExpr;
3607	if (Tok.is(K: tok::l_paren) && NextToken().is(K: tok::r_paren)) {
3608	NotCastExpr = true;
3609	} else {
3610	// Try parsing the cast-expression that may follow.
3611	// If it is not a cast-expression, NotCastExpr will be true and no token
3612	// will be consumed.
3613	ColonProt.restore();
3614	Result = ParseCastExpression(ParseKind: CastParseKind::AnyCastExpr,
3615	isAddressOfOperand: false /*isAddressofOperand*/, NotCastExpr,
3616	// type-id has priority.
3617	isTypeCast: TypeCastState::IsTypeCast);
3618	}
3619
3620	// If we parsed a cast-expression, it's really a type-id, otherwise it's
3621	// an expression.
3622	ParseAs =
3623	NotCastExpr ? ParenParseOption::SimpleExpr : ParenParseOption::CastExpr;
3624	}
3625
3626	// Create a fake EOF to mark end of Toks buffer.
3627	Token AttrEnd;
3628	AttrEnd.startToken();
3629	AttrEnd.setKind(tok::eof);
3630	AttrEnd.setLocation(Tok.getLocation());
3631	AttrEnd.setEofData(Toks.data());
3632	Toks.push_back(Elt: AttrEnd);
3633
3634	// The current token should go after the cached tokens.
3635	Toks.push_back(Elt: Tok);
3636	// Re-enter the stored parenthesized tokens into the token stream, so we may
3637	// parse them now.
3638	PP.EnterTokenStream(Toks, /*DisableMacroExpansion*/ true,
3639	/*IsReinject*/ true);
3640	// Drop the current token and bring the first cached one. It's the same token
3641	// as when we entered this function.
3642	ConsumeAnyToken();
3643
3644	if (ParseAs >= ParenParseOption::CompoundLiteral) {
3645	// Parse the type declarator.
3646	DeclSpec DS(AttrFactory);
3647	Declarator DeclaratorInfo(DS, ParsedAttributesView::none(),
3648	DeclaratorContext::TypeName);
3649	{
3650	ColonProtectionRAIIObject InnerColonProtection(*this);
3651	ParseSpecifierQualifierList(DS);
3652	ParseDeclarator(D&: DeclaratorInfo);
3653	}
3654
3655	// Match the ')'.
3656	Tracker.consumeClose();
3657	ColonProt.restore();
3658
3659	// Consume EOF marker for Toks buffer.
3660	assert(Tok.is(tok::eof) && Tok.getEofData() == AttrEnd.getEofData());
3661	ConsumeAnyToken();
3662
3663	if (ParseAs == ParenParseOption::CompoundLiteral) {
3664	ExprType = ParenParseOption::CompoundLiteral;
3665	if (DeclaratorInfo.isInvalidType())
3666	return ExprError();
3667
3668	TypeResult Ty = Actions.ActOnTypeName(D&: DeclaratorInfo);
3669	return ParseCompoundLiteralExpression(Ty: Ty.get(),
3670	LParenLoc: Tracker.getOpenLocation(),
3671	RParenLoc: Tracker.getCloseLocation());
3672	}
3673
3674	// We parsed '(' type-id ')' and the thing after it wasn't a '{'.
3675	assert(ParseAs == ParenParseOption::CastExpr);
3676
3677	if (DeclaratorInfo.isInvalidType())
3678	return ExprError();
3679
3680	// Result is what ParseCastExpression returned earlier.
3681	if (!Result.isInvalid())
3682	Result = Actions.ActOnCastExpr(S: getCurScope(), LParenLoc: Tracker.getOpenLocation(),
3683	D&: DeclaratorInfo, Ty&: CastTy,
3684	RParenLoc: Tracker.getCloseLocation(), CastExpr: Result.get());
3685	return Result;
3686	}
3687
3688	// Not a compound literal, and not followed by a cast-expression.
3689	assert(ParseAs == ParenParseOption::SimpleExpr);
3690
3691	ExprType = ParenParseOption::SimpleExpr;
3692	Result = ParseExpression();
3693	if (!Result.isInvalid() && Tok.is(K: tok::r_paren))
3694	Result = Actions.ActOnParenExpr(L: Tracker.getOpenLocation(),
3695	R: Tok.getLocation(), E: Result.get());
3696
3697	// Match the ')'.
3698	if (Result.isInvalid()) {
3699	while (Tok.isNot(K: tok::eof))
3700	ConsumeAnyToken();
3701	assert(Tok.getEofData() == AttrEnd.getEofData());
3702	ConsumeAnyToken();
3703	return ExprError();
3704	}
3705
3706	Tracker.consumeClose();
3707	// Consume EOF marker for Toks buffer.
3708	assert(Tok.is(tok::eof) && Tok.getEofData() == AttrEnd.getEofData());
3709	ConsumeAnyToken();
3710	return Result;
3711	}
3712
3713	ExprResult Parser::ParseBuiltinBitCast() {
3714	SourceLocation KWLoc = ConsumeToken();
3715
3716	BalancedDelimiterTracker T(*this, tok::l_paren);
3717	if (T.expectAndConsume(diag::err_expected_lparen_after, "__builtin_bit_cast"))
3718	return ExprError();
3719
3720	// Parse the common declaration-specifiers piece.
3721	DeclSpec DS(AttrFactory);
3722	ParseSpecifierQualifierList(DS);
3723
3724	// Parse the abstract-declarator, if present.
3725	Declarator DeclaratorInfo(DS, ParsedAttributesView::none(),
3726	DeclaratorContext::TypeName);
3727	ParseDeclarator(D&: DeclaratorInfo);
3728
3729	if (ExpectAndConsume(ExpectedTok: tok::comma)) {
3730	Diag(Tok.getLocation(), diag::err_expected) << tok::comma;
3731	SkipUntil(T: tok::r_paren, Flags: StopAtSemi);
3732	return ExprError();
3733	}
3734
3735	ExprResult Operand = ParseExpression();
3736
3737	if (T.consumeClose())
3738	return ExprError();
3739
3740	if (Operand.isInvalid() || DeclaratorInfo.isInvalidType())
3741	return ExprError();
3742
3743	return Actions.ActOnBuiltinBitCastExpr(KWLoc, Dcl&: DeclaratorInfo, Operand,
3744	RParenLoc: T.getCloseLocation());
3745	}
3746