xref: /openbsd/gnu/llvm/clang/lib/Parse/Parser.cpp (revision 12c85518)
1 //===--- Parser.cpp - C Language Family Parser ----------------------------===//
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 Parser interfaces.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/Parse/Parser.h"
14 #include "clang/AST/ASTConsumer.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/DeclTemplate.h"
17 #include "clang/Basic/FileManager.h"
18 #include "clang/Parse/ParseDiagnostic.h"
19 #include "clang/Parse/RAIIObjectsForParser.h"
20 #include "clang/Sema/DeclSpec.h"
21 #include "clang/Sema/ParsedTemplate.h"
22 #include "clang/Sema/Scope.h"
23 #include "llvm/Support/Path.h"
24 using namespace clang;
25 
26 
27 namespace {
28 /// A comment handler that passes comments found by the preprocessor
29 /// to the parser action.
30 class ActionCommentHandler : public CommentHandler {
31   Sema &S;
32 
33 public:
ActionCommentHandler(Sema & S)34   explicit ActionCommentHandler(Sema &S) : S(S) { }
35 
HandleComment(Preprocessor & PP,SourceRange Comment)36   bool HandleComment(Preprocessor &PP, SourceRange Comment) override {
37     S.ActOnComment(Comment);
38     return false;
39   }
40 };
41 } // end anonymous namespace
42 
getSEHExceptKeyword()43 IdentifierInfo *Parser::getSEHExceptKeyword() {
44   // __except is accepted as a (contextual) keyword
45   if (!Ident__except && (getLangOpts().MicrosoftExt || getLangOpts().Borland))
46     Ident__except = PP.getIdentifierInfo("__except");
47 
48   return Ident__except;
49 }
50 
Parser(Preprocessor & pp,Sema & actions,bool skipFunctionBodies)51 Parser::Parser(Preprocessor &pp, Sema &actions, bool skipFunctionBodies)
52     : PP(pp), PreferredType(pp.isCodeCompletionEnabled()), Actions(actions),
53       Diags(PP.getDiagnostics()), GreaterThanIsOperator(true),
54       ColonIsSacred(false), InMessageExpression(false),
55       TemplateParameterDepth(0), ParsingInObjCContainer(false) {
56   SkipFunctionBodies = pp.isCodeCompletionEnabled() || skipFunctionBodies;
57   Tok.startToken();
58   Tok.setKind(tok::eof);
59   Actions.CurScope = nullptr;
60   NumCachedScopes = 0;
61   CurParsedObjCImpl = nullptr;
62 
63   // Add #pragma handlers. These are removed and destroyed in the
64   // destructor.
65   initializePragmaHandlers();
66 
67   CommentSemaHandler.reset(new ActionCommentHandler(actions));
68   PP.addCommentHandler(CommentSemaHandler.get());
69 
70   PP.setCodeCompletionHandler(*this);
71 }
72 
Diag(SourceLocation Loc,unsigned DiagID)73 DiagnosticBuilder Parser::Diag(SourceLocation Loc, unsigned DiagID) {
74   return Diags.Report(Loc, DiagID);
75 }
76 
Diag(const Token & Tok,unsigned DiagID)77 DiagnosticBuilder Parser::Diag(const Token &Tok, unsigned DiagID) {
78   return Diag(Tok.getLocation(), DiagID);
79 }
80 
81 /// Emits a diagnostic suggesting parentheses surrounding a
82 /// given range.
83 ///
84 /// \param Loc The location where we'll emit the diagnostic.
85 /// \param DK The kind of diagnostic to emit.
86 /// \param ParenRange Source range enclosing code that should be parenthesized.
SuggestParentheses(SourceLocation Loc,unsigned DK,SourceRange ParenRange)87 void Parser::SuggestParentheses(SourceLocation Loc, unsigned DK,
88                                 SourceRange ParenRange) {
89   SourceLocation EndLoc = PP.getLocForEndOfToken(ParenRange.getEnd());
90   if (!ParenRange.getEnd().isFileID() || EndLoc.isInvalid()) {
91     // We can't display the parentheses, so just dig the
92     // warning/error and return.
93     Diag(Loc, DK);
94     return;
95   }
96 
97   Diag(Loc, DK)
98     << FixItHint::CreateInsertion(ParenRange.getBegin(), "(")
99     << FixItHint::CreateInsertion(EndLoc, ")");
100 }
101 
IsCommonTypo(tok::TokenKind ExpectedTok,const Token & Tok)102 static bool IsCommonTypo(tok::TokenKind ExpectedTok, const Token &Tok) {
103   switch (ExpectedTok) {
104   case tok::semi:
105     return Tok.is(tok::colon) || Tok.is(tok::comma); // : or , for ;
106   default: return false;
107   }
108 }
109 
ExpectAndConsume(tok::TokenKind ExpectedTok,unsigned DiagID,StringRef Msg)110 bool Parser::ExpectAndConsume(tok::TokenKind ExpectedTok, unsigned DiagID,
111                               StringRef Msg) {
112   if (Tok.is(ExpectedTok) || Tok.is(tok::code_completion)) {
113     ConsumeAnyToken();
114     return false;
115   }
116 
117   // Detect common single-character typos and resume.
118   if (IsCommonTypo(ExpectedTok, Tok)) {
119     SourceLocation Loc = Tok.getLocation();
120     {
121       DiagnosticBuilder DB = Diag(Loc, DiagID);
122       DB << FixItHint::CreateReplacement(
123                 SourceRange(Loc), tok::getPunctuatorSpelling(ExpectedTok));
124       if (DiagID == diag::err_expected)
125         DB << ExpectedTok;
126       else if (DiagID == diag::err_expected_after)
127         DB << Msg << ExpectedTok;
128       else
129         DB << Msg;
130     }
131 
132     // Pretend there wasn't a problem.
133     ConsumeAnyToken();
134     return false;
135   }
136 
137   SourceLocation EndLoc = PP.getLocForEndOfToken(PrevTokLocation);
138   const char *Spelling = nullptr;
139   if (EndLoc.isValid())
140     Spelling = tok::getPunctuatorSpelling(ExpectedTok);
141 
142   DiagnosticBuilder DB =
143       Spelling
144           ? Diag(EndLoc, DiagID) << FixItHint::CreateInsertion(EndLoc, Spelling)
145           : Diag(Tok, DiagID);
146   if (DiagID == diag::err_expected)
147     DB << ExpectedTok;
148   else if (DiagID == diag::err_expected_after)
149     DB << Msg << ExpectedTok;
150   else
151     DB << Msg;
152 
153   return true;
154 }
155 
ExpectAndConsumeSemi(unsigned DiagID,StringRef TokenUsed)156 bool Parser::ExpectAndConsumeSemi(unsigned DiagID, StringRef TokenUsed) {
157   if (TryConsumeToken(tok::semi))
158     return false;
159 
160   if (Tok.is(tok::code_completion)) {
161     handleUnexpectedCodeCompletionToken();
162     return false;
163   }
164 
165   if ((Tok.is(tok::r_paren) || Tok.is(tok::r_square)) &&
166       NextToken().is(tok::semi)) {
167     Diag(Tok, diag::err_extraneous_token_before_semi)
168       << PP.getSpelling(Tok)
169       << FixItHint::CreateRemoval(Tok.getLocation());
170     ConsumeAnyToken(); // The ')' or ']'.
171     ConsumeToken(); // The ';'.
172     return false;
173   }
174 
175   return ExpectAndConsume(tok::semi, DiagID , TokenUsed);
176 }
177 
ConsumeExtraSemi(ExtraSemiKind Kind,DeclSpec::TST TST)178 void Parser::ConsumeExtraSemi(ExtraSemiKind Kind, DeclSpec::TST TST) {
179   if (!Tok.is(tok::semi)) return;
180 
181   bool HadMultipleSemis = false;
182   SourceLocation StartLoc = Tok.getLocation();
183   SourceLocation EndLoc = Tok.getLocation();
184   ConsumeToken();
185 
186   while ((Tok.is(tok::semi) && !Tok.isAtStartOfLine())) {
187     HadMultipleSemis = true;
188     EndLoc = Tok.getLocation();
189     ConsumeToken();
190   }
191 
192   // C++11 allows extra semicolons at namespace scope, but not in any of the
193   // other contexts.
194   if (Kind == OutsideFunction && getLangOpts().CPlusPlus) {
195     if (getLangOpts().CPlusPlus11)
196       Diag(StartLoc, diag::warn_cxx98_compat_top_level_semi)
197           << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
198     else
199       Diag(StartLoc, diag::ext_extra_semi_cxx11)
200           << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
201     return;
202   }
203 
204   if (Kind != AfterMemberFunctionDefinition || HadMultipleSemis)
205     Diag(StartLoc, diag::ext_extra_semi)
206         << Kind << DeclSpec::getSpecifierName(TST,
207                                     Actions.getASTContext().getPrintingPolicy())
208         << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
209   else
210     // A single semicolon is valid after a member function definition.
211     Diag(StartLoc, diag::warn_extra_semi_after_mem_fn_def)
212       << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
213 }
214 
expectIdentifier()215 bool Parser::expectIdentifier() {
216   if (Tok.is(tok::identifier))
217     return false;
218   if (const auto *II = Tok.getIdentifierInfo()) {
219     if (II->isCPlusPlusKeyword(getLangOpts())) {
220       Diag(Tok, diag::err_expected_token_instead_of_objcxx_keyword)
221           << tok::identifier << Tok.getIdentifierInfo();
222       // Objective-C++: Recover by treating this keyword as a valid identifier.
223       return false;
224     }
225   }
226   Diag(Tok, diag::err_expected) << tok::identifier;
227   return true;
228 }
229 
checkCompoundToken(SourceLocation FirstTokLoc,tok::TokenKind FirstTokKind,CompoundToken Op)230 void Parser::checkCompoundToken(SourceLocation FirstTokLoc,
231                                 tok::TokenKind FirstTokKind, CompoundToken Op) {
232   if (FirstTokLoc.isInvalid())
233     return;
234   SourceLocation SecondTokLoc = Tok.getLocation();
235 
236   // If either token is in a macro, we expect both tokens to come from the same
237   // macro expansion.
238   if ((FirstTokLoc.isMacroID() || SecondTokLoc.isMacroID()) &&
239       PP.getSourceManager().getFileID(FirstTokLoc) !=
240           PP.getSourceManager().getFileID(SecondTokLoc)) {
241     Diag(FirstTokLoc, diag::warn_compound_token_split_by_macro)
242         << (FirstTokKind == Tok.getKind()) << FirstTokKind << Tok.getKind()
243         << static_cast<int>(Op) << SourceRange(FirstTokLoc);
244     Diag(SecondTokLoc, diag::note_compound_token_split_second_token_here)
245         << (FirstTokKind == Tok.getKind()) << Tok.getKind()
246         << SourceRange(SecondTokLoc);
247     return;
248   }
249 
250   // We expect the tokens to abut.
251   if (Tok.hasLeadingSpace() || Tok.isAtStartOfLine()) {
252     SourceLocation SpaceLoc = PP.getLocForEndOfToken(FirstTokLoc);
253     if (SpaceLoc.isInvalid())
254       SpaceLoc = FirstTokLoc;
255     Diag(SpaceLoc, diag::warn_compound_token_split_by_whitespace)
256         << (FirstTokKind == Tok.getKind()) << FirstTokKind << Tok.getKind()
257         << static_cast<int>(Op) << SourceRange(FirstTokLoc, SecondTokLoc);
258     return;
259   }
260 }
261 
262 //===----------------------------------------------------------------------===//
263 // Error recovery.
264 //===----------------------------------------------------------------------===//
265 
HasFlagsSet(Parser::SkipUntilFlags L,Parser::SkipUntilFlags R)266 static bool HasFlagsSet(Parser::SkipUntilFlags L, Parser::SkipUntilFlags R) {
267   return (static_cast<unsigned>(L) & static_cast<unsigned>(R)) != 0;
268 }
269 
270 /// SkipUntil - Read tokens until we get to the specified token, then consume
271 /// it (unless no flag StopBeforeMatch).  Because we cannot guarantee that the
272 /// token will ever occur, this skips to the next token, or to some likely
273 /// good stopping point.  If StopAtSemi is true, skipping will stop at a ';'
274 /// character.
275 ///
276 /// If SkipUntil finds the specified token, it returns true, otherwise it
277 /// returns false.
SkipUntil(ArrayRef<tok::TokenKind> Toks,SkipUntilFlags Flags)278 bool Parser::SkipUntil(ArrayRef<tok::TokenKind> Toks, SkipUntilFlags Flags) {
279   // We always want this function to skip at least one token if the first token
280   // isn't T and if not at EOF.
281   bool isFirstTokenSkipped = true;
282   while (true) {
283     // If we found one of the tokens, stop and return true.
284     for (unsigned i = 0, NumToks = Toks.size(); i != NumToks; ++i) {
285       if (Tok.is(Toks[i])) {
286         if (HasFlagsSet(Flags, StopBeforeMatch)) {
287           // Noop, don't consume the token.
288         } else {
289           ConsumeAnyToken();
290         }
291         return true;
292       }
293     }
294 
295     // Important special case: The caller has given up and just wants us to
296     // skip the rest of the file. Do this without recursing, since we can
297     // get here precisely because the caller detected too much recursion.
298     if (Toks.size() == 1 && Toks[0] == tok::eof &&
299         !HasFlagsSet(Flags, StopAtSemi) &&
300         !HasFlagsSet(Flags, StopAtCodeCompletion)) {
301       while (Tok.isNot(tok::eof))
302         ConsumeAnyToken();
303       return true;
304     }
305 
306     switch (Tok.getKind()) {
307     case tok::eof:
308       // Ran out of tokens.
309       return false;
310 
311     case tok::annot_pragma_openmp:
312     case tok::annot_attr_openmp:
313     case tok::annot_pragma_openmp_end:
314       // Stop before an OpenMP pragma boundary.
315       if (OpenMPDirectiveParsing)
316         return false;
317       ConsumeAnnotationToken();
318       break;
319     case tok::annot_module_begin:
320     case tok::annot_module_end:
321     case tok::annot_module_include:
322       // Stop before we change submodules. They generally indicate a "good"
323       // place to pick up parsing again (except in the special case where
324       // we're trying to skip to EOF).
325       return false;
326 
327     case tok::code_completion:
328       if (!HasFlagsSet(Flags, StopAtCodeCompletion))
329         handleUnexpectedCodeCompletionToken();
330       return false;
331 
332     case tok::l_paren:
333       // Recursively skip properly-nested parens.
334       ConsumeParen();
335       if (HasFlagsSet(Flags, StopAtCodeCompletion))
336         SkipUntil(tok::r_paren, StopAtCodeCompletion);
337       else
338         SkipUntil(tok::r_paren);
339       break;
340     case tok::l_square:
341       // Recursively skip properly-nested square brackets.
342       ConsumeBracket();
343       if (HasFlagsSet(Flags, StopAtCodeCompletion))
344         SkipUntil(tok::r_square, StopAtCodeCompletion);
345       else
346         SkipUntil(tok::r_square);
347       break;
348     case tok::l_brace:
349       // Recursively skip properly-nested braces.
350       ConsumeBrace();
351       if (HasFlagsSet(Flags, StopAtCodeCompletion))
352         SkipUntil(tok::r_brace, StopAtCodeCompletion);
353       else
354         SkipUntil(tok::r_brace);
355       break;
356     case tok::question:
357       // Recursively skip ? ... : pairs; these function as brackets. But
358       // still stop at a semicolon if requested.
359       ConsumeToken();
360       SkipUntil(tok::colon,
361                 SkipUntilFlags(unsigned(Flags) &
362                                unsigned(StopAtCodeCompletion | StopAtSemi)));
363       break;
364 
365     // Okay, we found a ']' or '}' or ')', which we think should be balanced.
366     // Since the user wasn't looking for this token (if they were, it would
367     // already be handled), this isn't balanced.  If there is a LHS token at a
368     // higher level, we will assume that this matches the unbalanced token
369     // and return it.  Otherwise, this is a spurious RHS token, which we skip.
370     case tok::r_paren:
371       if (ParenCount && !isFirstTokenSkipped)
372         return false;  // Matches something.
373       ConsumeParen();
374       break;
375     case tok::r_square:
376       if (BracketCount && !isFirstTokenSkipped)
377         return false;  // Matches something.
378       ConsumeBracket();
379       break;
380     case tok::r_brace:
381       if (BraceCount && !isFirstTokenSkipped)
382         return false;  // Matches something.
383       ConsumeBrace();
384       break;
385 
386     case tok::semi:
387       if (HasFlagsSet(Flags, StopAtSemi))
388         return false;
389       [[fallthrough]];
390     default:
391       // Skip this token.
392       ConsumeAnyToken();
393       break;
394     }
395     isFirstTokenSkipped = false;
396   }
397 }
398 
399 //===----------------------------------------------------------------------===//
400 // Scope manipulation
401 //===----------------------------------------------------------------------===//
402 
403 /// EnterScope - Start a new scope.
EnterScope(unsigned ScopeFlags)404 void Parser::EnterScope(unsigned ScopeFlags) {
405   if (NumCachedScopes) {
406     Scope *N = ScopeCache[--NumCachedScopes];
407     N->Init(getCurScope(), ScopeFlags);
408     Actions.CurScope = N;
409   } else {
410     Actions.CurScope = new Scope(getCurScope(), ScopeFlags, Diags);
411   }
412 }
413 
414 /// ExitScope - Pop a scope off the scope stack.
ExitScope()415 void Parser::ExitScope() {
416   assert(getCurScope() && "Scope imbalance!");
417 
418   // Inform the actions module that this scope is going away if there are any
419   // decls in it.
420   Actions.ActOnPopScope(Tok.getLocation(), getCurScope());
421 
422   Scope *OldScope = getCurScope();
423   Actions.CurScope = OldScope->getParent();
424 
425   if (NumCachedScopes == ScopeCacheSize)
426     delete OldScope;
427   else
428     ScopeCache[NumCachedScopes++] = OldScope;
429 }
430 
431 /// Set the flags for the current scope to ScopeFlags. If ManageFlags is false,
432 /// this object does nothing.
ParseScopeFlags(Parser * Self,unsigned ScopeFlags,bool ManageFlags)433 Parser::ParseScopeFlags::ParseScopeFlags(Parser *Self, unsigned ScopeFlags,
434                                  bool ManageFlags)
435   : CurScope(ManageFlags ? Self->getCurScope() : nullptr) {
436   if (CurScope) {
437     OldFlags = CurScope->getFlags();
438     CurScope->setFlags(ScopeFlags);
439   }
440 }
441 
442 /// Restore the flags for the current scope to what they were before this
443 /// object overrode them.
~ParseScopeFlags()444 Parser::ParseScopeFlags::~ParseScopeFlags() {
445   if (CurScope)
446     CurScope->setFlags(OldFlags);
447 }
448 
449 
450 //===----------------------------------------------------------------------===//
451 // C99 6.9: External Definitions.
452 //===----------------------------------------------------------------------===//
453 
~Parser()454 Parser::~Parser() {
455   // If we still have scopes active, delete the scope tree.
456   delete getCurScope();
457   Actions.CurScope = nullptr;
458 
459   // Free the scope cache.
460   for (unsigned i = 0, e = NumCachedScopes; i != e; ++i)
461     delete ScopeCache[i];
462 
463   resetPragmaHandlers();
464 
465   PP.removeCommentHandler(CommentSemaHandler.get());
466 
467   PP.clearCodeCompletionHandler();
468 
469   DestroyTemplateIds();
470 }
471 
472 /// Initialize - Warm up the parser.
473 ///
Initialize()474 void Parser::Initialize() {
475   // Create the translation unit scope.  Install it as the current scope.
476   assert(getCurScope() == nullptr && "A scope is already active?");
477   EnterScope(Scope::DeclScope);
478   Actions.ActOnTranslationUnitScope(getCurScope());
479 
480   // Initialization for Objective-C context sensitive keywords recognition.
481   // Referenced in Parser::ParseObjCTypeQualifierList.
482   if (getLangOpts().ObjC) {
483     ObjCTypeQuals[objc_in] = &PP.getIdentifierTable().get("in");
484     ObjCTypeQuals[objc_out] = &PP.getIdentifierTable().get("out");
485     ObjCTypeQuals[objc_inout] = &PP.getIdentifierTable().get("inout");
486     ObjCTypeQuals[objc_oneway] = &PP.getIdentifierTable().get("oneway");
487     ObjCTypeQuals[objc_bycopy] = &PP.getIdentifierTable().get("bycopy");
488     ObjCTypeQuals[objc_byref] = &PP.getIdentifierTable().get("byref");
489     ObjCTypeQuals[objc_nonnull] = &PP.getIdentifierTable().get("nonnull");
490     ObjCTypeQuals[objc_nullable] = &PP.getIdentifierTable().get("nullable");
491     ObjCTypeQuals[objc_null_unspecified]
492       = &PP.getIdentifierTable().get("null_unspecified");
493   }
494 
495   Ident_instancetype = nullptr;
496   Ident_final = nullptr;
497   Ident_sealed = nullptr;
498   Ident_abstract = nullptr;
499   Ident_override = nullptr;
500   Ident_GNU_final = nullptr;
501   Ident_import = nullptr;
502   Ident_module = nullptr;
503 
504   Ident_super = &PP.getIdentifierTable().get("super");
505 
506   Ident_vector = nullptr;
507   Ident_bool = nullptr;
508   Ident_Bool = nullptr;
509   Ident_pixel = nullptr;
510   if (getLangOpts().AltiVec || getLangOpts().ZVector) {
511     Ident_vector = &PP.getIdentifierTable().get("vector");
512     Ident_bool = &PP.getIdentifierTable().get("bool");
513     Ident_Bool = &PP.getIdentifierTable().get("_Bool");
514   }
515   if (getLangOpts().AltiVec)
516     Ident_pixel = &PP.getIdentifierTable().get("pixel");
517 
518   Ident_introduced = nullptr;
519   Ident_deprecated = nullptr;
520   Ident_obsoleted = nullptr;
521   Ident_unavailable = nullptr;
522   Ident_strict = nullptr;
523   Ident_replacement = nullptr;
524 
525   Ident_language = Ident_defined_in = Ident_generated_declaration = nullptr;
526 
527   Ident__except = nullptr;
528 
529   Ident__exception_code = Ident__exception_info = nullptr;
530   Ident__abnormal_termination = Ident___exception_code = nullptr;
531   Ident___exception_info = Ident___abnormal_termination = nullptr;
532   Ident_GetExceptionCode = Ident_GetExceptionInfo = nullptr;
533   Ident_AbnormalTermination = nullptr;
534 
535   if(getLangOpts().Borland) {
536     Ident__exception_info        = PP.getIdentifierInfo("_exception_info");
537     Ident___exception_info       = PP.getIdentifierInfo("__exception_info");
538     Ident_GetExceptionInfo       = PP.getIdentifierInfo("GetExceptionInformation");
539     Ident__exception_code        = PP.getIdentifierInfo("_exception_code");
540     Ident___exception_code       = PP.getIdentifierInfo("__exception_code");
541     Ident_GetExceptionCode       = PP.getIdentifierInfo("GetExceptionCode");
542     Ident__abnormal_termination  = PP.getIdentifierInfo("_abnormal_termination");
543     Ident___abnormal_termination = PP.getIdentifierInfo("__abnormal_termination");
544     Ident_AbnormalTermination    = PP.getIdentifierInfo("AbnormalTermination");
545 
546     PP.SetPoisonReason(Ident__exception_code,diag::err_seh___except_block);
547     PP.SetPoisonReason(Ident___exception_code,diag::err_seh___except_block);
548     PP.SetPoisonReason(Ident_GetExceptionCode,diag::err_seh___except_block);
549     PP.SetPoisonReason(Ident__exception_info,diag::err_seh___except_filter);
550     PP.SetPoisonReason(Ident___exception_info,diag::err_seh___except_filter);
551     PP.SetPoisonReason(Ident_GetExceptionInfo,diag::err_seh___except_filter);
552     PP.SetPoisonReason(Ident__abnormal_termination,diag::err_seh___finally_block);
553     PP.SetPoisonReason(Ident___abnormal_termination,diag::err_seh___finally_block);
554     PP.SetPoisonReason(Ident_AbnormalTermination,diag::err_seh___finally_block);
555   }
556 
557   if (getLangOpts().CPlusPlusModules) {
558     Ident_import = PP.getIdentifierInfo("import");
559     Ident_module = PP.getIdentifierInfo("module");
560   }
561 
562   Actions.Initialize();
563 
564   // Prime the lexer look-ahead.
565   ConsumeToken();
566 }
567 
DestroyTemplateIds()568 void Parser::DestroyTemplateIds() {
569   for (TemplateIdAnnotation *Id : TemplateIds)
570     Id->Destroy();
571   TemplateIds.clear();
572 }
573 
574 /// Parse the first top-level declaration in a translation unit.
575 ///
576 ///   translation-unit:
577 /// [C]     external-declaration
578 /// [C]     translation-unit external-declaration
579 /// [C++]   top-level-declaration-seq[opt]
580 /// [C++20] global-module-fragment[opt] module-declaration
581 ///                 top-level-declaration-seq[opt] private-module-fragment[opt]
582 ///
583 /// Note that in C, it is an error if there is no first declaration.
ParseFirstTopLevelDecl(DeclGroupPtrTy & Result,Sema::ModuleImportState & ImportState)584 bool Parser::ParseFirstTopLevelDecl(DeclGroupPtrTy &Result,
585                                     Sema::ModuleImportState &ImportState) {
586   Actions.ActOnStartOfTranslationUnit();
587 
588   // For C++20 modules, a module decl must be the first in the TU.  We also
589   // need to track module imports.
590   ImportState = Sema::ModuleImportState::FirstDecl;
591   bool NoTopLevelDecls = ParseTopLevelDecl(Result, ImportState);
592 
593   // C11 6.9p1 says translation units must have at least one top-level
594   // declaration. C++ doesn't have this restriction. We also don't want to
595   // complain if we have a precompiled header, although technically if the PCH
596   // is empty we should still emit the (pedantic) diagnostic.
597   // If the main file is a header, we're only pretending it's a TU; don't warn.
598   if (NoTopLevelDecls && !Actions.getASTContext().getExternalSource() &&
599       !getLangOpts().CPlusPlus && !getLangOpts().IsHeaderFile)
600     Diag(diag::ext_empty_translation_unit);
601 
602   return NoTopLevelDecls;
603 }
604 
605 /// ParseTopLevelDecl - Parse one top-level declaration, return whatever the
606 /// action tells us to.  This returns true if the EOF was encountered.
607 ///
608 ///   top-level-declaration:
609 ///           declaration
610 /// [C++20]   module-import-declaration
ParseTopLevelDecl(DeclGroupPtrTy & Result,Sema::ModuleImportState & ImportState)611 bool Parser::ParseTopLevelDecl(DeclGroupPtrTy &Result,
612                                Sema::ModuleImportState &ImportState) {
613   DestroyTemplateIdAnnotationsRAIIObj CleanupRAII(*this);
614 
615   // Skip over the EOF token, flagging end of previous input for incremental
616   // processing
617   if (PP.isIncrementalProcessingEnabled() && Tok.is(tok::eof))
618     ConsumeToken();
619 
620   Result = nullptr;
621   switch (Tok.getKind()) {
622   case tok::annot_pragma_unused:
623     HandlePragmaUnused();
624     return false;
625 
626   case tok::kw_export:
627     switch (NextToken().getKind()) {
628     case tok::kw_module:
629       goto module_decl;
630 
631     // Note: no need to handle kw_import here. We only form kw_import under
632     // the Modules TS, and in that case 'export import' is parsed as an
633     // export-declaration containing an import-declaration.
634 
635     // Recognize context-sensitive C++20 'export module' and 'export import'
636     // declarations.
637     case tok::identifier: {
638       IdentifierInfo *II = NextToken().getIdentifierInfo();
639       if ((II == Ident_module || II == Ident_import) &&
640           GetLookAheadToken(2).isNot(tok::coloncolon)) {
641         if (II == Ident_module)
642           goto module_decl;
643         else
644           goto import_decl;
645       }
646       break;
647     }
648 
649     default:
650       break;
651     }
652     break;
653 
654   case tok::kw_module:
655   module_decl:
656     Result = ParseModuleDecl(ImportState);
657     return false;
658 
659   case tok::kw_import:
660   import_decl: {
661     Decl *ImportDecl = ParseModuleImport(SourceLocation(), ImportState);
662     Result = Actions.ConvertDeclToDeclGroup(ImportDecl);
663     return false;
664   }
665 
666   case tok::annot_module_include: {
667     auto Loc = Tok.getLocation();
668     Module *Mod = reinterpret_cast<Module *>(Tok.getAnnotationValue());
669     // FIXME: We need a better way to disambiguate C++ clang modules and
670     // standard C++ modules.
671     if (!getLangOpts().CPlusPlusModules || !Mod->isHeaderUnit())
672       Actions.ActOnModuleInclude(Loc, Mod);
673     else {
674       DeclResult Import =
675           Actions.ActOnModuleImport(Loc, SourceLocation(), Loc, Mod);
676       Decl *ImportDecl = Import.isInvalid() ? nullptr : Import.get();
677       Result = Actions.ConvertDeclToDeclGroup(ImportDecl);
678     }
679     ConsumeAnnotationToken();
680     return false;
681   }
682 
683   case tok::annot_module_begin:
684     Actions.ActOnModuleBegin(Tok.getLocation(), reinterpret_cast<Module *>(
685                                                     Tok.getAnnotationValue()));
686     ConsumeAnnotationToken();
687     ImportState = Sema::ModuleImportState::NotACXX20Module;
688     return false;
689 
690   case tok::annot_module_end:
691     Actions.ActOnModuleEnd(Tok.getLocation(), reinterpret_cast<Module *>(
692                                                   Tok.getAnnotationValue()));
693     ConsumeAnnotationToken();
694     ImportState = Sema::ModuleImportState::NotACXX20Module;
695     return false;
696 
697   case tok::eof:
698     // Check whether -fmax-tokens= was reached.
699     if (PP.getMaxTokens() != 0 && PP.getTokenCount() > PP.getMaxTokens()) {
700       PP.Diag(Tok.getLocation(), diag::warn_max_tokens_total)
701           << PP.getTokenCount() << PP.getMaxTokens();
702       SourceLocation OverrideLoc = PP.getMaxTokensOverrideLoc();
703       if (OverrideLoc.isValid()) {
704         PP.Diag(OverrideLoc, diag::note_max_tokens_total_override);
705       }
706     }
707 
708     // Late template parsing can begin.
709     Actions.SetLateTemplateParser(LateTemplateParserCallback, nullptr, this);
710     Actions.ActOnEndOfTranslationUnit();
711     //else don't tell Sema that we ended parsing: more input might come.
712     return true;
713 
714   case tok::identifier:
715     // C++2a [basic.link]p3:
716     //   A token sequence beginning with 'export[opt] module' or
717     //   'export[opt] import' and not immediately followed by '::'
718     //   is never interpreted as the declaration of a top-level-declaration.
719     if ((Tok.getIdentifierInfo() == Ident_module ||
720          Tok.getIdentifierInfo() == Ident_import) &&
721         NextToken().isNot(tok::coloncolon)) {
722       if (Tok.getIdentifierInfo() == Ident_module)
723         goto module_decl;
724       else
725         goto import_decl;
726     }
727     break;
728 
729   default:
730     break;
731   }
732 
733   ParsedAttributes DeclAttrs(AttrFactory);
734   ParsedAttributes DeclSpecAttrs(AttrFactory);
735   // GNU attributes are applied to the declaration specification while the
736   // standard attributes are applied to the declaration.  We parse the two
737   // attribute sets into different containters so we can apply them during
738   // the regular parsing process.
739   while (MaybeParseCXX11Attributes(DeclAttrs) ||
740          MaybeParseGNUAttributes(DeclSpecAttrs))
741     ;
742 
743   Result = ParseExternalDeclaration(DeclAttrs, DeclSpecAttrs);
744   // An empty Result might mean a line with ';' or some parsing error, ignore
745   // it.
746   if (Result) {
747     if (ImportState == Sema::ModuleImportState::FirstDecl)
748       // First decl was not modular.
749       ImportState = Sema::ModuleImportState::NotACXX20Module;
750     else if (ImportState == Sema::ModuleImportState::ImportAllowed)
751       // Non-imports disallow further imports.
752       ImportState = Sema::ModuleImportState::ImportFinished;
753     else if (ImportState ==
754              Sema::ModuleImportState::PrivateFragmentImportAllowed)
755       // Non-imports disallow further imports.
756       ImportState = Sema::ModuleImportState::PrivateFragmentImportFinished;
757   }
758   return false;
759 }
760 
761 /// ParseExternalDeclaration:
762 ///
763 /// The `Attrs` that are passed in are C++11 attributes and appertain to the
764 /// declaration.
765 ///
766 ///       external-declaration: [C99 6.9], declaration: [C++ dcl.dcl]
767 ///         function-definition
768 ///         declaration
769 /// [GNU]   asm-definition
770 /// [GNU]   __extension__ external-declaration
771 /// [OBJC]  objc-class-definition
772 /// [OBJC]  objc-class-declaration
773 /// [OBJC]  objc-alias-declaration
774 /// [OBJC]  objc-protocol-definition
775 /// [OBJC]  objc-method-definition
776 /// [OBJC]  @end
777 /// [C++]   linkage-specification
778 /// [GNU] asm-definition:
779 ///         simple-asm-expr ';'
780 /// [C++11] empty-declaration
781 /// [C++11] attribute-declaration
782 ///
783 /// [C++11] empty-declaration:
784 ///           ';'
785 ///
786 /// [C++0x/GNU] 'extern' 'template' declaration
787 ///
788 /// [Modules-TS] module-import-declaration
789 ///
790 Parser::DeclGroupPtrTy
ParseExternalDeclaration(ParsedAttributes & Attrs,ParsedAttributes & DeclSpecAttrs,ParsingDeclSpec * DS)791 Parser::ParseExternalDeclaration(ParsedAttributes &Attrs,
792                                  ParsedAttributes &DeclSpecAttrs,
793                                  ParsingDeclSpec *DS) {
794   DestroyTemplateIdAnnotationsRAIIObj CleanupRAII(*this);
795   ParenBraceBracketBalancer BalancerRAIIObj(*this);
796 
797   if (PP.isCodeCompletionReached()) {
798     cutOffParsing();
799     return nullptr;
800   }
801 
802   Decl *SingleDecl = nullptr;
803   switch (Tok.getKind()) {
804   case tok::annot_pragma_vis:
805     HandlePragmaVisibility();
806     return nullptr;
807   case tok::annot_pragma_pack:
808     HandlePragmaPack();
809     return nullptr;
810   case tok::annot_pragma_msstruct:
811     HandlePragmaMSStruct();
812     return nullptr;
813   case tok::annot_pragma_align:
814     HandlePragmaAlign();
815     return nullptr;
816   case tok::annot_pragma_weak:
817     HandlePragmaWeak();
818     return nullptr;
819   case tok::annot_pragma_weakalias:
820     HandlePragmaWeakAlias();
821     return nullptr;
822   case tok::annot_pragma_redefine_extname:
823     HandlePragmaRedefineExtname();
824     return nullptr;
825   case tok::annot_pragma_fp_contract:
826     HandlePragmaFPContract();
827     return nullptr;
828   case tok::annot_pragma_fenv_access:
829   case tok::annot_pragma_fenv_access_ms:
830     HandlePragmaFEnvAccess();
831     return nullptr;
832   case tok::annot_pragma_fenv_round:
833     HandlePragmaFEnvRound();
834     return nullptr;
835   case tok::annot_pragma_float_control:
836     HandlePragmaFloatControl();
837     return nullptr;
838   case tok::annot_pragma_fp:
839     HandlePragmaFP();
840     break;
841   case tok::annot_pragma_opencl_extension:
842     HandlePragmaOpenCLExtension();
843     return nullptr;
844   case tok::annot_attr_openmp:
845   case tok::annot_pragma_openmp: {
846     AccessSpecifier AS = AS_none;
847     return ParseOpenMPDeclarativeDirectiveWithExtDecl(AS, Attrs);
848   }
849   case tok::annot_pragma_ms_pointers_to_members:
850     HandlePragmaMSPointersToMembers();
851     return nullptr;
852   case tok::annot_pragma_ms_vtordisp:
853     HandlePragmaMSVtorDisp();
854     return nullptr;
855   case tok::annot_pragma_ms_pragma:
856     HandlePragmaMSPragma();
857     return nullptr;
858   case tok::annot_pragma_dump:
859     HandlePragmaDump();
860     return nullptr;
861   case tok::annot_pragma_attribute:
862     HandlePragmaAttribute();
863     return nullptr;
864   case tok::semi:
865     // Either a C++11 empty-declaration or attribute-declaration.
866     SingleDecl =
867         Actions.ActOnEmptyDeclaration(getCurScope(), Attrs, Tok.getLocation());
868     ConsumeExtraSemi(OutsideFunction);
869     break;
870   case tok::r_brace:
871     Diag(Tok, diag::err_extraneous_closing_brace);
872     ConsumeBrace();
873     return nullptr;
874   case tok::eof:
875     Diag(Tok, diag::err_expected_external_declaration);
876     return nullptr;
877   case tok::kw___extension__: {
878     // __extension__ silences extension warnings in the subexpression.
879     ExtensionRAIIObject O(Diags);  // Use RAII to do this.
880     ConsumeToken();
881     return ParseExternalDeclaration(Attrs, DeclSpecAttrs);
882   }
883   case tok::kw_asm: {
884     ProhibitAttributes(Attrs);
885 
886     SourceLocation StartLoc = Tok.getLocation();
887     SourceLocation EndLoc;
888 
889     ExprResult Result(ParseSimpleAsm(/*ForAsmLabel*/ false, &EndLoc));
890 
891     // Check if GNU-style InlineAsm is disabled.
892     // Empty asm string is allowed because it will not introduce
893     // any assembly code.
894     if (!(getLangOpts().GNUAsm || Result.isInvalid())) {
895       const auto *SL = cast<StringLiteral>(Result.get());
896       if (!SL->getString().trim().empty())
897         Diag(StartLoc, diag::err_gnu_inline_asm_disabled);
898     }
899 
900     ExpectAndConsume(tok::semi, diag::err_expected_after,
901                      "top-level asm block");
902 
903     if (Result.isInvalid())
904       return nullptr;
905     SingleDecl = Actions.ActOnFileScopeAsmDecl(Result.get(), StartLoc, EndLoc);
906     break;
907   }
908   case tok::at:
909     return ParseObjCAtDirectives(Attrs, DeclSpecAttrs);
910   case tok::minus:
911   case tok::plus:
912     if (!getLangOpts().ObjC) {
913       Diag(Tok, diag::err_expected_external_declaration);
914       ConsumeToken();
915       return nullptr;
916     }
917     SingleDecl = ParseObjCMethodDefinition();
918     break;
919   case tok::code_completion:
920     cutOffParsing();
921     if (CurParsedObjCImpl) {
922       // Code-complete Objective-C methods even without leading '-'/'+' prefix.
923       Actions.CodeCompleteObjCMethodDecl(getCurScope(),
924                                          /*IsInstanceMethod=*/std::nullopt,
925                                          /*ReturnType=*/nullptr);
926     }
927     Actions.CodeCompleteOrdinaryName(
928         getCurScope(),
929         CurParsedObjCImpl ? Sema::PCC_ObjCImplementation : Sema::PCC_Namespace);
930     return nullptr;
931   case tok::kw_import: {
932     Sema::ModuleImportState IS = Sema::ModuleImportState::NotACXX20Module;
933     if (getLangOpts().CPlusPlusModules) {
934       llvm_unreachable("not expecting a c++20 import here");
935       ProhibitAttributes(Attrs);
936     }
937     SingleDecl = ParseModuleImport(SourceLocation(), IS);
938   } break;
939   case tok::kw_export:
940     if (getLangOpts().CPlusPlusModules || getLangOpts().ModulesTS) {
941       ProhibitAttributes(Attrs);
942       SingleDecl = ParseExportDeclaration();
943       break;
944     }
945     // This must be 'export template'. Parse it so we can diagnose our lack
946     // of support.
947     [[fallthrough]];
948   case tok::kw_using:
949   case tok::kw_namespace:
950   case tok::kw_typedef:
951   case tok::kw_template:
952   case tok::kw_static_assert:
953   case tok::kw__Static_assert:
954     // A function definition cannot start with any of these keywords.
955     {
956       SourceLocation DeclEnd;
957       return ParseDeclaration(DeclaratorContext::File, DeclEnd, Attrs,
958                               DeclSpecAttrs);
959     }
960 
961   case tok::kw_cbuffer:
962   case tok::kw_tbuffer:
963     if (getLangOpts().HLSL) {
964       SourceLocation DeclEnd;
965       return ParseDeclaration(DeclaratorContext::File, DeclEnd, Attrs,
966                               DeclSpecAttrs);
967     }
968     goto dont_know;
969 
970   case tok::kw_static:
971     // Parse (then ignore) 'static' prior to a template instantiation. This is
972     // a GCC extension that we intentionally do not support.
973     if (getLangOpts().CPlusPlus && NextToken().is(tok::kw_template)) {
974       Diag(ConsumeToken(), diag::warn_static_inline_explicit_inst_ignored)
975         << 0;
976       SourceLocation DeclEnd;
977       return ParseDeclaration(DeclaratorContext::File, DeclEnd, Attrs,
978                               DeclSpecAttrs);
979     }
980     goto dont_know;
981 
982   case tok::kw_inline:
983     if (getLangOpts().CPlusPlus) {
984       tok::TokenKind NextKind = NextToken().getKind();
985 
986       // Inline namespaces. Allowed as an extension even in C++03.
987       if (NextKind == tok::kw_namespace) {
988         SourceLocation DeclEnd;
989         return ParseDeclaration(DeclaratorContext::File, DeclEnd, Attrs,
990                                 DeclSpecAttrs);
991       }
992 
993       // Parse (then ignore) 'inline' prior to a template instantiation. This is
994       // a GCC extension that we intentionally do not support.
995       if (NextKind == tok::kw_template) {
996         Diag(ConsumeToken(), diag::warn_static_inline_explicit_inst_ignored)
997           << 1;
998         SourceLocation DeclEnd;
999         return ParseDeclaration(DeclaratorContext::File, DeclEnd, Attrs,
1000                                 DeclSpecAttrs);
1001       }
1002     }
1003     goto dont_know;
1004 
1005   case tok::kw_extern:
1006     if (getLangOpts().CPlusPlus && NextToken().is(tok::kw_template)) {
1007       // Extern templates
1008       SourceLocation ExternLoc = ConsumeToken();
1009       SourceLocation TemplateLoc = ConsumeToken();
1010       Diag(ExternLoc, getLangOpts().CPlusPlus11 ?
1011              diag::warn_cxx98_compat_extern_template :
1012              diag::ext_extern_template) << SourceRange(ExternLoc, TemplateLoc);
1013       SourceLocation DeclEnd;
1014       return Actions.ConvertDeclToDeclGroup(ParseExplicitInstantiation(
1015           DeclaratorContext::File, ExternLoc, TemplateLoc, DeclEnd, Attrs));
1016     }
1017     goto dont_know;
1018 
1019   case tok::kw___if_exists:
1020   case tok::kw___if_not_exists:
1021     ParseMicrosoftIfExistsExternalDeclaration();
1022     return nullptr;
1023 
1024   case tok::kw_module:
1025     Diag(Tok, diag::err_unexpected_module_decl);
1026     SkipUntil(tok::semi);
1027     return nullptr;
1028 
1029   default:
1030   dont_know:
1031     if (Tok.isEditorPlaceholder()) {
1032       ConsumeToken();
1033       return nullptr;
1034     }
1035     if (PP.isIncrementalProcessingEnabled() &&
1036         !isDeclarationStatement(/*DisambiguatingWithExpression=*/true))
1037       return ParseTopLevelStmtDecl();
1038 
1039     // We can't tell whether this is a function-definition or declaration yet.
1040     if (!SingleDecl)
1041       return ParseDeclarationOrFunctionDefinition(Attrs, DeclSpecAttrs, DS);
1042   }
1043 
1044   // This routine returns a DeclGroup, if the thing we parsed only contains a
1045   // single decl, convert it now.
1046   return Actions.ConvertDeclToDeclGroup(SingleDecl);
1047 }
1048 
1049 /// Determine whether the current token, if it occurs after a
1050 /// declarator, continues a declaration or declaration list.
isDeclarationAfterDeclarator()1051 bool Parser::isDeclarationAfterDeclarator() {
1052   // Check for '= delete' or '= default'
1053   if (getLangOpts().CPlusPlus && Tok.is(tok::equal)) {
1054     const Token &KW = NextToken();
1055     if (KW.is(tok::kw_default) || KW.is(tok::kw_delete))
1056       return false;
1057   }
1058 
1059   return Tok.is(tok::equal) ||      // int X()=  -> not a function def
1060     Tok.is(tok::comma) ||           // int X(),  -> not a function def
1061     Tok.is(tok::semi)  ||           // int X();  -> not a function def
1062     Tok.is(tok::kw_asm) ||          // int X() __asm__ -> not a function def
1063     Tok.is(tok::kw___attribute) ||  // int X() __attr__ -> not a function def
1064     (getLangOpts().CPlusPlus &&
1065      Tok.is(tok::l_paren));         // int X(0) -> not a function def [C++]
1066 }
1067 
1068 /// Determine whether the current token, if it occurs after a
1069 /// declarator, indicates the start of a function definition.
isStartOfFunctionDefinition(const ParsingDeclarator & Declarator)1070 bool Parser::isStartOfFunctionDefinition(const ParsingDeclarator &Declarator) {
1071   assert(Declarator.isFunctionDeclarator() && "Isn't a function declarator");
1072   if (Tok.is(tok::l_brace))   // int X() {}
1073     return true;
1074 
1075   // Handle K&R C argument lists: int X(f) int f; {}
1076   if (!getLangOpts().CPlusPlus &&
1077       Declarator.getFunctionTypeInfo().isKNRPrototype())
1078     return isDeclarationSpecifier(ImplicitTypenameContext::No);
1079 
1080   if (getLangOpts().CPlusPlus && Tok.is(tok::equal)) {
1081     const Token &KW = NextToken();
1082     return KW.is(tok::kw_default) || KW.is(tok::kw_delete);
1083   }
1084 
1085   return Tok.is(tok::colon) ||         // X() : Base() {} (used for ctors)
1086          Tok.is(tok::kw_try);          // X() try { ... }
1087 }
1088 
1089 /// Parse either a function-definition or a declaration.  We can't tell which
1090 /// we have until we read up to the compound-statement in function-definition.
1091 /// TemplateParams, if non-NULL, provides the template parameters when we're
1092 /// parsing a C++ template-declaration.
1093 ///
1094 ///       function-definition: [C99 6.9.1]
1095 ///         decl-specs      declarator declaration-list[opt] compound-statement
1096 /// [C90] function-definition: [C99 6.7.1] - implicit int result
1097 /// [C90]   decl-specs[opt] declarator declaration-list[opt] compound-statement
1098 ///
1099 ///       declaration: [C99 6.7]
1100 ///         declaration-specifiers init-declarator-list[opt] ';'
1101 /// [!C99]  init-declarator-list ';'                   [TODO: warn in c99 mode]
1102 /// [OMP]   threadprivate-directive
1103 /// [OMP]   allocate-directive                         [TODO]
1104 ///
ParseDeclOrFunctionDefInternal(ParsedAttributes & Attrs,ParsedAttributes & DeclSpecAttrs,ParsingDeclSpec & DS,AccessSpecifier AS)1105 Parser::DeclGroupPtrTy Parser::ParseDeclOrFunctionDefInternal(
1106     ParsedAttributes &Attrs, ParsedAttributes &DeclSpecAttrs,
1107     ParsingDeclSpec &DS, AccessSpecifier AS) {
1108   // Because we assume that the DeclSpec has not yet been initialised, we simply
1109   // overwrite the source range and attribute the provided leading declspec
1110   // attributes.
1111   assert(DS.getSourceRange().isInvalid() &&
1112          "expected uninitialised source range");
1113   DS.SetRangeStart(DeclSpecAttrs.Range.getBegin());
1114   DS.SetRangeEnd(DeclSpecAttrs.Range.getEnd());
1115   DS.takeAttributesFrom(DeclSpecAttrs);
1116 
1117   MaybeParseMicrosoftAttributes(DS.getAttributes());
1118   // Parse the common declaration-specifiers piece.
1119   ParseDeclarationSpecifiers(DS, ParsedTemplateInfo(), AS,
1120                              DeclSpecContext::DSC_top_level);
1121 
1122   // If we had a free-standing type definition with a missing semicolon, we
1123   // may get this far before the problem becomes obvious.
1124   if (DS.hasTagDefinition() && DiagnoseMissingSemiAfterTagDefinition(
1125                                    DS, AS, DeclSpecContext::DSC_top_level))
1126     return nullptr;
1127 
1128   // C99 6.7.2.3p6: Handle "struct-or-union identifier;", "enum { X };"
1129   // declaration-specifiers init-declarator-list[opt] ';'
1130   if (Tok.is(tok::semi)) {
1131     auto LengthOfTSTToken = [](DeclSpec::TST TKind) {
1132       assert(DeclSpec::isDeclRep(TKind));
1133       switch(TKind) {
1134       case DeclSpec::TST_class:
1135         return 5;
1136       case DeclSpec::TST_struct:
1137         return 6;
1138       case DeclSpec::TST_union:
1139         return 5;
1140       case DeclSpec::TST_enum:
1141         return 4;
1142       case DeclSpec::TST_interface:
1143         return 9;
1144       default:
1145         llvm_unreachable("we only expect to get the length of the class/struct/union/enum");
1146       }
1147 
1148     };
1149     // Suggest correct location to fix '[[attrib]] struct' to 'struct [[attrib]]'
1150     SourceLocation CorrectLocationForAttributes =
1151         DeclSpec::isDeclRep(DS.getTypeSpecType())
1152             ? DS.getTypeSpecTypeLoc().getLocWithOffset(
1153                   LengthOfTSTToken(DS.getTypeSpecType()))
1154             : SourceLocation();
1155     ProhibitAttributes(Attrs, CorrectLocationForAttributes);
1156     ConsumeToken();
1157     RecordDecl *AnonRecord = nullptr;
1158     Decl *TheDecl = Actions.ParsedFreeStandingDeclSpec(
1159         getCurScope(), AS_none, DS, ParsedAttributesView::none(), AnonRecord);
1160     DS.complete(TheDecl);
1161     if (AnonRecord) {
1162       Decl* decls[] = {AnonRecord, TheDecl};
1163       return Actions.BuildDeclaratorGroup(decls);
1164     }
1165     return Actions.ConvertDeclToDeclGroup(TheDecl);
1166   }
1167 
1168   // ObjC2 allows prefix attributes on class interfaces and protocols.
1169   // FIXME: This still needs better diagnostics. We should only accept
1170   // attributes here, no types, etc.
1171   if (getLangOpts().ObjC && Tok.is(tok::at)) {
1172     SourceLocation AtLoc = ConsumeToken(); // the "@"
1173     if (!Tok.isObjCAtKeyword(tok::objc_interface) &&
1174         !Tok.isObjCAtKeyword(tok::objc_protocol) &&
1175         !Tok.isObjCAtKeyword(tok::objc_implementation)) {
1176       Diag(Tok, diag::err_objc_unexpected_attr);
1177       SkipUntil(tok::semi);
1178       return nullptr;
1179     }
1180 
1181     DS.abort();
1182     DS.takeAttributesFrom(Attrs);
1183 
1184     const char *PrevSpec = nullptr;
1185     unsigned DiagID;
1186     if (DS.SetTypeSpecType(DeclSpec::TST_unspecified, AtLoc, PrevSpec, DiagID,
1187                            Actions.getASTContext().getPrintingPolicy()))
1188       Diag(AtLoc, DiagID) << PrevSpec;
1189 
1190     if (Tok.isObjCAtKeyword(tok::objc_protocol))
1191       return ParseObjCAtProtocolDeclaration(AtLoc, DS.getAttributes());
1192 
1193     if (Tok.isObjCAtKeyword(tok::objc_implementation))
1194       return ParseObjCAtImplementationDeclaration(AtLoc, DS.getAttributes());
1195 
1196     return Actions.ConvertDeclToDeclGroup(
1197             ParseObjCAtInterfaceDeclaration(AtLoc, DS.getAttributes()));
1198   }
1199 
1200   // If the declspec consisted only of 'extern' and we have a string
1201   // literal following it, this must be a C++ linkage specifier like
1202   // 'extern "C"'.
1203   if (getLangOpts().CPlusPlus && isTokenStringLiteral() &&
1204       DS.getStorageClassSpec() == DeclSpec::SCS_extern &&
1205       DS.getParsedSpecifiers() == DeclSpec::PQ_StorageClassSpecifier) {
1206     ProhibitAttributes(Attrs);
1207     Decl *TheDecl = ParseLinkage(DS, DeclaratorContext::File);
1208     return Actions.ConvertDeclToDeclGroup(TheDecl);
1209   }
1210 
1211   return ParseDeclGroup(DS, DeclaratorContext::File, Attrs);
1212 }
1213 
ParseDeclarationOrFunctionDefinition(ParsedAttributes & Attrs,ParsedAttributes & DeclSpecAttrs,ParsingDeclSpec * DS,AccessSpecifier AS)1214 Parser::DeclGroupPtrTy Parser::ParseDeclarationOrFunctionDefinition(
1215     ParsedAttributes &Attrs, ParsedAttributes &DeclSpecAttrs,
1216     ParsingDeclSpec *DS, AccessSpecifier AS) {
1217   if (DS) {
1218     return ParseDeclOrFunctionDefInternal(Attrs, DeclSpecAttrs, *DS, AS);
1219   } else {
1220     ParsingDeclSpec PDS(*this);
1221     // Must temporarily exit the objective-c container scope for
1222     // parsing c constructs and re-enter objc container scope
1223     // afterwards.
1224     ObjCDeclContextSwitch ObjCDC(*this);
1225 
1226     return ParseDeclOrFunctionDefInternal(Attrs, DeclSpecAttrs, PDS, AS);
1227   }
1228 }
1229 
1230 /// ParseFunctionDefinition - We parsed and verified that the specified
1231 /// Declarator is well formed.  If this is a K&R-style function, read the
1232 /// parameters declaration-list, then start the compound-statement.
1233 ///
1234 ///       function-definition: [C99 6.9.1]
1235 ///         decl-specs      declarator declaration-list[opt] compound-statement
1236 /// [C90] function-definition: [C99 6.7.1] - implicit int result
1237 /// [C90]   decl-specs[opt] declarator declaration-list[opt] compound-statement
1238 /// [C++] function-definition: [C++ 8.4]
1239 ///         decl-specifier-seq[opt] declarator ctor-initializer[opt]
1240 ///         function-body
1241 /// [C++] function-definition: [C++ 8.4]
1242 ///         decl-specifier-seq[opt] declarator function-try-block
1243 ///
ParseFunctionDefinition(ParsingDeclarator & D,const ParsedTemplateInfo & TemplateInfo,LateParsedAttrList * LateParsedAttrs)1244 Decl *Parser::ParseFunctionDefinition(ParsingDeclarator &D,
1245                                       const ParsedTemplateInfo &TemplateInfo,
1246                                       LateParsedAttrList *LateParsedAttrs) {
1247   // Poison SEH identifiers so they are flagged as illegal in function bodies.
1248   PoisonSEHIdentifiersRAIIObject PoisonSEHIdentifiers(*this, true);
1249   const DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
1250   TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
1251 
1252   // If this is C89 and the declspecs were completely missing, fudge in an
1253   // implicit int.  We do this here because this is the only place where
1254   // declaration-specifiers are completely optional in the grammar.
1255   if (getLangOpts().isImplicitIntRequired() && D.getDeclSpec().isEmpty()) {
1256     Diag(D.getIdentifierLoc(), diag::warn_missing_type_specifier)
1257         << D.getDeclSpec().getSourceRange();
1258     const char *PrevSpec;
1259     unsigned DiagID;
1260     const PrintingPolicy &Policy = Actions.getASTContext().getPrintingPolicy();
1261     D.getMutableDeclSpec().SetTypeSpecType(DeclSpec::TST_int,
1262                                            D.getIdentifierLoc(),
1263                                            PrevSpec, DiagID,
1264                                            Policy);
1265     D.SetRangeBegin(D.getDeclSpec().getSourceRange().getBegin());
1266   }
1267 
1268   // If this declaration was formed with a K&R-style identifier list for the
1269   // arguments, parse declarations for all of the args next.
1270   // int foo(a,b) int a; float b; {}
1271   if (FTI.isKNRPrototype())
1272     ParseKNRParamDeclarations(D);
1273 
1274   // We should have either an opening brace or, in a C++ constructor,
1275   // we may have a colon.
1276   if (Tok.isNot(tok::l_brace) &&
1277       (!getLangOpts().CPlusPlus ||
1278        (Tok.isNot(tok::colon) && Tok.isNot(tok::kw_try) &&
1279         Tok.isNot(tok::equal)))) {
1280     Diag(Tok, diag::err_expected_fn_body);
1281 
1282     // Skip over garbage, until we get to '{'.  Don't eat the '{'.
1283     SkipUntil(tok::l_brace, StopAtSemi | StopBeforeMatch);
1284 
1285     // If we didn't find the '{', bail out.
1286     if (Tok.isNot(tok::l_brace))
1287       return nullptr;
1288   }
1289 
1290   // Check to make sure that any normal attributes are allowed to be on
1291   // a definition.  Late parsed attributes are checked at the end.
1292   if (Tok.isNot(tok::equal)) {
1293     for (const ParsedAttr &AL : D.getAttributes())
1294       if (AL.isKnownToGCC() && !AL.isStandardAttributeSyntax())
1295         Diag(AL.getLoc(), diag::warn_attribute_on_function_definition) << AL;
1296   }
1297 
1298   // In delayed template parsing mode, for function template we consume the
1299   // tokens and store them for late parsing at the end of the translation unit.
1300   if (getLangOpts().DelayedTemplateParsing && Tok.isNot(tok::equal) &&
1301       TemplateInfo.Kind == ParsedTemplateInfo::Template &&
1302       Actions.canDelayFunctionBody(D)) {
1303     MultiTemplateParamsArg TemplateParameterLists(*TemplateInfo.TemplateParams);
1304 
1305     ParseScope BodyScope(this, Scope::FnScope | Scope::DeclScope |
1306                                    Scope::CompoundStmtScope);
1307     Scope *ParentScope = getCurScope()->getParent();
1308 
1309     D.setFunctionDefinitionKind(FunctionDefinitionKind::Definition);
1310     Decl *DP = Actions.HandleDeclarator(ParentScope, D,
1311                                         TemplateParameterLists);
1312     D.complete(DP);
1313     D.getMutableDeclSpec().abort();
1314 
1315     if (SkipFunctionBodies && (!DP || Actions.canSkipFunctionBody(DP)) &&
1316         trySkippingFunctionBody()) {
1317       BodyScope.Exit();
1318       return Actions.ActOnSkippedFunctionBody(DP);
1319     }
1320 
1321     CachedTokens Toks;
1322     LexTemplateFunctionForLateParsing(Toks);
1323 
1324     if (DP) {
1325       FunctionDecl *FnD = DP->getAsFunction();
1326       Actions.CheckForFunctionRedefinition(FnD);
1327       Actions.MarkAsLateParsedTemplate(FnD, DP, Toks);
1328     }
1329     return DP;
1330   }
1331   else if (CurParsedObjCImpl &&
1332            !TemplateInfo.TemplateParams &&
1333            (Tok.is(tok::l_brace) || Tok.is(tok::kw_try) ||
1334             Tok.is(tok::colon)) &&
1335       Actions.CurContext->isTranslationUnit()) {
1336     ParseScope BodyScope(this, Scope::FnScope | Scope::DeclScope |
1337                                    Scope::CompoundStmtScope);
1338     Scope *ParentScope = getCurScope()->getParent();
1339 
1340     D.setFunctionDefinitionKind(FunctionDefinitionKind::Definition);
1341     Decl *FuncDecl = Actions.HandleDeclarator(ParentScope, D,
1342                                               MultiTemplateParamsArg());
1343     D.complete(FuncDecl);
1344     D.getMutableDeclSpec().abort();
1345     if (FuncDecl) {
1346       // Consume the tokens and store them for later parsing.
1347       StashAwayMethodOrFunctionBodyTokens(FuncDecl);
1348       CurParsedObjCImpl->HasCFunction = true;
1349       return FuncDecl;
1350     }
1351     // FIXME: Should we really fall through here?
1352   }
1353 
1354   // Enter a scope for the function body.
1355   ParseScope BodyScope(this, Scope::FnScope | Scope::DeclScope |
1356                                  Scope::CompoundStmtScope);
1357 
1358   // Parse function body eagerly if it is either '= delete;' or '= default;' as
1359   // ActOnStartOfFunctionDef needs to know whether the function is deleted.
1360   Sema::FnBodyKind BodyKind = Sema::FnBodyKind::Other;
1361   SourceLocation KWLoc;
1362   if (TryConsumeToken(tok::equal)) {
1363     assert(getLangOpts().CPlusPlus && "Only C++ function definitions have '='");
1364 
1365     if (TryConsumeToken(tok::kw_delete, KWLoc)) {
1366       Diag(KWLoc, getLangOpts().CPlusPlus11
1367                       ? diag::warn_cxx98_compat_defaulted_deleted_function
1368                       : diag::ext_defaulted_deleted_function)
1369           << 1 /* deleted */;
1370       BodyKind = Sema::FnBodyKind::Delete;
1371     } else if (TryConsumeToken(tok::kw_default, KWLoc)) {
1372       Diag(KWLoc, getLangOpts().CPlusPlus11
1373                       ? diag::warn_cxx98_compat_defaulted_deleted_function
1374                       : diag::ext_defaulted_deleted_function)
1375           << 0 /* defaulted */;
1376       BodyKind = Sema::FnBodyKind::Default;
1377     } else {
1378       llvm_unreachable("function definition after = not 'delete' or 'default'");
1379     }
1380 
1381     if (Tok.is(tok::comma)) {
1382       Diag(KWLoc, diag::err_default_delete_in_multiple_declaration)
1383           << (BodyKind == Sema::FnBodyKind::Delete);
1384       SkipUntil(tok::semi);
1385     } else if (ExpectAndConsume(tok::semi, diag::err_expected_after,
1386                                 BodyKind == Sema::FnBodyKind::Delete
1387                                     ? "delete"
1388                                     : "default")) {
1389       SkipUntil(tok::semi);
1390     }
1391   }
1392 
1393   // Tell the actions module that we have entered a function definition with the
1394   // specified Declarator for the function.
1395   Sema::SkipBodyInfo SkipBody;
1396   Decl *Res = Actions.ActOnStartOfFunctionDef(getCurScope(), D,
1397                                               TemplateInfo.TemplateParams
1398                                                   ? *TemplateInfo.TemplateParams
1399                                                   : MultiTemplateParamsArg(),
1400                                               &SkipBody, BodyKind);
1401 
1402   if (SkipBody.ShouldSkip) {
1403     // Do NOT enter SkipFunctionBody if we already consumed the tokens.
1404     if (BodyKind == Sema::FnBodyKind::Other)
1405       SkipFunctionBody();
1406 
1407     return Res;
1408   }
1409 
1410   // Break out of the ParsingDeclarator context before we parse the body.
1411   D.complete(Res);
1412 
1413   // Break out of the ParsingDeclSpec context, too.  This const_cast is
1414   // safe because we're always the sole owner.
1415   D.getMutableDeclSpec().abort();
1416 
1417   if (BodyKind != Sema::FnBodyKind::Other) {
1418     Actions.SetFunctionBodyKind(Res, KWLoc, BodyKind);
1419     Stmt *GeneratedBody = Res ? Res->getBody() : nullptr;
1420     Actions.ActOnFinishFunctionBody(Res, GeneratedBody, false);
1421     return Res;
1422   }
1423 
1424   // With abbreviated function templates - we need to explicitly add depth to
1425   // account for the implicit template parameter list induced by the template.
1426   if (auto *Template = dyn_cast_or_null<FunctionTemplateDecl>(Res))
1427     if (Template->isAbbreviated() &&
1428         Template->getTemplateParameters()->getParam(0)->isImplicit())
1429       // First template parameter is implicit - meaning no explicit template
1430       // parameter list was specified.
1431       CurTemplateDepthTracker.addDepth(1);
1432 
1433   if (SkipFunctionBodies && (!Res || Actions.canSkipFunctionBody(Res)) &&
1434       trySkippingFunctionBody()) {
1435     BodyScope.Exit();
1436     Actions.ActOnSkippedFunctionBody(Res);
1437     return Actions.ActOnFinishFunctionBody(Res, nullptr, false);
1438   }
1439 
1440   if (Tok.is(tok::kw_try))
1441     return ParseFunctionTryBlock(Res, BodyScope);
1442 
1443   // If we have a colon, then we're probably parsing a C++
1444   // ctor-initializer.
1445   if (Tok.is(tok::colon)) {
1446     ParseConstructorInitializer(Res);
1447 
1448     // Recover from error.
1449     if (!Tok.is(tok::l_brace)) {
1450       BodyScope.Exit();
1451       Actions.ActOnFinishFunctionBody(Res, nullptr);
1452       return Res;
1453     }
1454   } else
1455     Actions.ActOnDefaultCtorInitializers(Res);
1456 
1457   // Late attributes are parsed in the same scope as the function body.
1458   if (LateParsedAttrs)
1459     ParseLexedAttributeList(*LateParsedAttrs, Res, false, true);
1460 
1461   return ParseFunctionStatementBody(Res, BodyScope);
1462 }
1463 
SkipFunctionBody()1464 void Parser::SkipFunctionBody() {
1465   if (Tok.is(tok::equal)) {
1466     SkipUntil(tok::semi);
1467     return;
1468   }
1469 
1470   bool IsFunctionTryBlock = Tok.is(tok::kw_try);
1471   if (IsFunctionTryBlock)
1472     ConsumeToken();
1473 
1474   CachedTokens Skipped;
1475   if (ConsumeAndStoreFunctionPrologue(Skipped))
1476     SkipMalformedDecl();
1477   else {
1478     SkipUntil(tok::r_brace);
1479     while (IsFunctionTryBlock && Tok.is(tok::kw_catch)) {
1480       SkipUntil(tok::l_brace);
1481       SkipUntil(tok::r_brace);
1482     }
1483   }
1484 }
1485 
1486 /// ParseKNRParamDeclarations - Parse 'declaration-list[opt]' which provides
1487 /// types for a function with a K&R-style identifier list for arguments.
ParseKNRParamDeclarations(Declarator & D)1488 void Parser::ParseKNRParamDeclarations(Declarator &D) {
1489   // We know that the top-level of this declarator is a function.
1490   DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
1491 
1492   // Enter function-declaration scope, limiting any declarators to the
1493   // function prototype scope, including parameter declarators.
1494   ParseScope PrototypeScope(this, Scope::FunctionPrototypeScope |
1495                             Scope::FunctionDeclarationScope | Scope::DeclScope);
1496 
1497   // Read all the argument declarations.
1498   while (isDeclarationSpecifier(ImplicitTypenameContext::No)) {
1499     SourceLocation DSStart = Tok.getLocation();
1500 
1501     // Parse the common declaration-specifiers piece.
1502     DeclSpec DS(AttrFactory);
1503     ParseDeclarationSpecifiers(DS);
1504 
1505     // C99 6.9.1p6: 'each declaration in the declaration list shall have at
1506     // least one declarator'.
1507     // NOTE: GCC just makes this an ext-warn.  It's not clear what it does with
1508     // the declarations though.  It's trivial to ignore them, really hard to do
1509     // anything else with them.
1510     if (TryConsumeToken(tok::semi)) {
1511       Diag(DSStart, diag::err_declaration_does_not_declare_param);
1512       continue;
1513     }
1514 
1515     // C99 6.9.1p6: Declarations shall contain no storage-class specifiers other
1516     // than register.
1517     if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
1518         DS.getStorageClassSpec() != DeclSpec::SCS_register) {
1519       Diag(DS.getStorageClassSpecLoc(),
1520            diag::err_invalid_storage_class_in_func_decl);
1521       DS.ClearStorageClassSpecs();
1522     }
1523     if (DS.getThreadStorageClassSpec() != DeclSpec::TSCS_unspecified) {
1524       Diag(DS.getThreadStorageClassSpecLoc(),
1525            diag::err_invalid_storage_class_in_func_decl);
1526       DS.ClearStorageClassSpecs();
1527     }
1528 
1529     // Parse the first declarator attached to this declspec.
1530     Declarator ParmDeclarator(DS, ParsedAttributesView::none(),
1531                               DeclaratorContext::KNRTypeList);
1532     ParseDeclarator(ParmDeclarator);
1533 
1534     // Handle the full declarator list.
1535     while (true) {
1536       // If attributes are present, parse them.
1537       MaybeParseGNUAttributes(ParmDeclarator);
1538 
1539       // Ask the actions module to compute the type for this declarator.
1540       Decl *Param =
1541         Actions.ActOnParamDeclarator(getCurScope(), ParmDeclarator);
1542 
1543       if (Param &&
1544           // A missing identifier has already been diagnosed.
1545           ParmDeclarator.getIdentifier()) {
1546 
1547         // Scan the argument list looking for the correct param to apply this
1548         // type.
1549         for (unsigned i = 0; ; ++i) {
1550           // C99 6.9.1p6: those declarators shall declare only identifiers from
1551           // the identifier list.
1552           if (i == FTI.NumParams) {
1553             Diag(ParmDeclarator.getIdentifierLoc(), diag::err_no_matching_param)
1554               << ParmDeclarator.getIdentifier();
1555             break;
1556           }
1557 
1558           if (FTI.Params[i].Ident == ParmDeclarator.getIdentifier()) {
1559             // Reject redefinitions of parameters.
1560             if (FTI.Params[i].Param) {
1561               Diag(ParmDeclarator.getIdentifierLoc(),
1562                    diag::err_param_redefinition)
1563                  << ParmDeclarator.getIdentifier();
1564             } else {
1565               FTI.Params[i].Param = Param;
1566             }
1567             break;
1568           }
1569         }
1570       }
1571 
1572       // If we don't have a comma, it is either the end of the list (a ';') or
1573       // an error, bail out.
1574       if (Tok.isNot(tok::comma))
1575         break;
1576 
1577       ParmDeclarator.clear();
1578 
1579       // Consume the comma.
1580       ParmDeclarator.setCommaLoc(ConsumeToken());
1581 
1582       // Parse the next declarator.
1583       ParseDeclarator(ParmDeclarator);
1584     }
1585 
1586     // Consume ';' and continue parsing.
1587     if (!ExpectAndConsumeSemi(diag::err_expected_semi_declaration))
1588       continue;
1589 
1590     // Otherwise recover by skipping to next semi or mandatory function body.
1591     if (SkipUntil(tok::l_brace, StopAtSemi | StopBeforeMatch))
1592       break;
1593     TryConsumeToken(tok::semi);
1594   }
1595 
1596   // The actions module must verify that all arguments were declared.
1597   Actions.ActOnFinishKNRParamDeclarations(getCurScope(), D, Tok.getLocation());
1598 }
1599 
1600 
1601 /// ParseAsmStringLiteral - This is just a normal string-literal, but is not
1602 /// allowed to be a wide string, and is not subject to character translation.
1603 /// Unlike GCC, we also diagnose an empty string literal when parsing for an
1604 /// asm label as opposed to an asm statement, because such a construct does not
1605 /// behave well.
1606 ///
1607 /// [GNU] asm-string-literal:
1608 ///         string-literal
1609 ///
ParseAsmStringLiteral(bool ForAsmLabel)1610 ExprResult Parser::ParseAsmStringLiteral(bool ForAsmLabel) {
1611   if (!isTokenStringLiteral()) {
1612     Diag(Tok, diag::err_expected_string_literal)
1613       << /*Source='in...'*/0 << "'asm'";
1614     return ExprError();
1615   }
1616 
1617   ExprResult AsmString(ParseStringLiteralExpression());
1618   if (!AsmString.isInvalid()) {
1619     const auto *SL = cast<StringLiteral>(AsmString.get());
1620     if (!SL->isOrdinary()) {
1621       Diag(Tok, diag::err_asm_operand_wide_string_literal)
1622         << SL->isWide()
1623         << SL->getSourceRange();
1624       return ExprError();
1625     }
1626     if (ForAsmLabel && SL->getString().empty()) {
1627       Diag(Tok, diag::err_asm_operand_wide_string_literal)
1628           << 2 /* an empty */ << SL->getSourceRange();
1629       return ExprError();
1630     }
1631   }
1632   return AsmString;
1633 }
1634 
1635 /// ParseSimpleAsm
1636 ///
1637 /// [GNU] simple-asm-expr:
1638 ///         'asm' '(' asm-string-literal ')'
1639 ///
ParseSimpleAsm(bool ForAsmLabel,SourceLocation * EndLoc)1640 ExprResult Parser::ParseSimpleAsm(bool ForAsmLabel, SourceLocation *EndLoc) {
1641   assert(Tok.is(tok::kw_asm) && "Not an asm!");
1642   SourceLocation Loc = ConsumeToken();
1643 
1644   if (isGNUAsmQualifier(Tok)) {
1645     // Remove from the end of 'asm' to the end of the asm qualifier.
1646     SourceRange RemovalRange(PP.getLocForEndOfToken(Loc),
1647                              PP.getLocForEndOfToken(Tok.getLocation()));
1648     Diag(Tok, diag::err_global_asm_qualifier_ignored)
1649         << GNUAsmQualifiers::getQualifierName(getGNUAsmQualifier(Tok))
1650         << FixItHint::CreateRemoval(RemovalRange);
1651     ConsumeToken();
1652   }
1653 
1654   BalancedDelimiterTracker T(*this, tok::l_paren);
1655   if (T.consumeOpen()) {
1656     Diag(Tok, diag::err_expected_lparen_after) << "asm";
1657     return ExprError();
1658   }
1659 
1660   ExprResult Result(ParseAsmStringLiteral(ForAsmLabel));
1661 
1662   if (!Result.isInvalid()) {
1663     // Close the paren and get the location of the end bracket
1664     T.consumeClose();
1665     if (EndLoc)
1666       *EndLoc = T.getCloseLocation();
1667   } else if (SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch)) {
1668     if (EndLoc)
1669       *EndLoc = Tok.getLocation();
1670     ConsumeParen();
1671   }
1672 
1673   return Result;
1674 }
1675 
1676 /// Get the TemplateIdAnnotation from the token and put it in the
1677 /// cleanup pool so that it gets destroyed when parsing the current top level
1678 /// declaration is finished.
takeTemplateIdAnnotation(const Token & tok)1679 TemplateIdAnnotation *Parser::takeTemplateIdAnnotation(const Token &tok) {
1680   assert(tok.is(tok::annot_template_id) && "Expected template-id token");
1681   TemplateIdAnnotation *
1682       Id = static_cast<TemplateIdAnnotation *>(tok.getAnnotationValue());
1683   return Id;
1684 }
1685 
AnnotateScopeToken(CXXScopeSpec & SS,bool IsNewAnnotation)1686 void Parser::AnnotateScopeToken(CXXScopeSpec &SS, bool IsNewAnnotation) {
1687   // Push the current token back into the token stream (or revert it if it is
1688   // cached) and use an annotation scope token for current token.
1689   if (PP.isBacktrackEnabled())
1690     PP.RevertCachedTokens(1);
1691   else
1692     PP.EnterToken(Tok, /*IsReinject=*/true);
1693   Tok.setKind(tok::annot_cxxscope);
1694   Tok.setAnnotationValue(Actions.SaveNestedNameSpecifierAnnotation(SS));
1695   Tok.setAnnotationRange(SS.getRange());
1696 
1697   // In case the tokens were cached, have Preprocessor replace them
1698   // with the annotation token.  We don't need to do this if we've
1699   // just reverted back to a prior state.
1700   if (IsNewAnnotation)
1701     PP.AnnotateCachedTokens(Tok);
1702 }
1703 
1704 /// Attempt to classify the name at the current token position. This may
1705 /// form a type, scope or primary expression annotation, or replace the token
1706 /// with a typo-corrected keyword. This is only appropriate when the current
1707 /// name must refer to an entity which has already been declared.
1708 ///
1709 /// \param CCC Indicates how to perform typo-correction for this name. If NULL,
1710 ///        no typo correction will be performed.
1711 /// \param AllowImplicitTypename Whether we are in a context where a dependent
1712 ///        nested-name-specifier without typename is treated as a type (e.g.
1713 ///        T::type).
1714 Parser::AnnotatedNameKind
TryAnnotateName(CorrectionCandidateCallback * CCC,ImplicitTypenameContext AllowImplicitTypename)1715 Parser::TryAnnotateName(CorrectionCandidateCallback *CCC,
1716                         ImplicitTypenameContext AllowImplicitTypename) {
1717   assert(Tok.is(tok::identifier) || Tok.is(tok::annot_cxxscope));
1718 
1719   const bool EnteringContext = false;
1720   const bool WasScopeAnnotation = Tok.is(tok::annot_cxxscope);
1721 
1722   CXXScopeSpec SS;
1723   if (getLangOpts().CPlusPlus &&
1724       ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/nullptr,
1725                                      /*ObjectHasErrors=*/false,
1726                                      EnteringContext))
1727     return ANK_Error;
1728 
1729   if (Tok.isNot(tok::identifier) || SS.isInvalid()) {
1730     if (TryAnnotateTypeOrScopeTokenAfterScopeSpec(SS, !WasScopeAnnotation,
1731                                                   AllowImplicitTypename))
1732       return ANK_Error;
1733     return ANK_Unresolved;
1734   }
1735 
1736   IdentifierInfo *Name = Tok.getIdentifierInfo();
1737   SourceLocation NameLoc = Tok.getLocation();
1738 
1739   // FIXME: Move the tentative declaration logic into ClassifyName so we can
1740   // typo-correct to tentatively-declared identifiers.
1741   if (isTentativelyDeclared(Name) && SS.isEmpty()) {
1742     // Identifier has been tentatively declared, and thus cannot be resolved as
1743     // an expression. Fall back to annotating it as a type.
1744     if (TryAnnotateTypeOrScopeTokenAfterScopeSpec(SS, !WasScopeAnnotation,
1745                                                   AllowImplicitTypename))
1746       return ANK_Error;
1747     return Tok.is(tok::annot_typename) ? ANK_Success : ANK_TentativeDecl;
1748   }
1749 
1750   Token Next = NextToken();
1751 
1752   // Look up and classify the identifier. We don't perform any typo-correction
1753   // after a scope specifier, because in general we can't recover from typos
1754   // there (eg, after correcting 'A::template B<X>::C' [sic], we would need to
1755   // jump back into scope specifier parsing).
1756   Sema::NameClassification Classification = Actions.ClassifyName(
1757       getCurScope(), SS, Name, NameLoc, Next, SS.isEmpty() ? CCC : nullptr);
1758 
1759   // If name lookup found nothing and we guessed that this was a template name,
1760   // double-check before committing to that interpretation. C++20 requires that
1761   // we interpret this as a template-id if it can be, but if it can't be, then
1762   // this is an error recovery case.
1763   if (Classification.getKind() == Sema::NC_UndeclaredTemplate &&
1764       isTemplateArgumentList(1) == TPResult::False) {
1765     // It's not a template-id; re-classify without the '<' as a hint.
1766     Token FakeNext = Next;
1767     FakeNext.setKind(tok::unknown);
1768     Classification =
1769         Actions.ClassifyName(getCurScope(), SS, Name, NameLoc, FakeNext,
1770                              SS.isEmpty() ? CCC : nullptr);
1771   }
1772 
1773   switch (Classification.getKind()) {
1774   case Sema::NC_Error:
1775     return ANK_Error;
1776 
1777   case Sema::NC_Keyword:
1778     // The identifier was typo-corrected to a keyword.
1779     Tok.setIdentifierInfo(Name);
1780     Tok.setKind(Name->getTokenID());
1781     PP.TypoCorrectToken(Tok);
1782     if (SS.isNotEmpty())
1783       AnnotateScopeToken(SS, !WasScopeAnnotation);
1784     // We've "annotated" this as a keyword.
1785     return ANK_Success;
1786 
1787   case Sema::NC_Unknown:
1788     // It's not something we know about. Leave it unannotated.
1789     break;
1790 
1791   case Sema::NC_Type: {
1792     if (TryAltiVecVectorToken())
1793       // vector has been found as a type id when altivec is enabled but
1794       // this is followed by a declaration specifier so this is really the
1795       // altivec vector token.  Leave it unannotated.
1796       break;
1797     SourceLocation BeginLoc = NameLoc;
1798     if (SS.isNotEmpty())
1799       BeginLoc = SS.getBeginLoc();
1800 
1801     /// An Objective-C object type followed by '<' is a specialization of
1802     /// a parameterized class type or a protocol-qualified type.
1803     ParsedType Ty = Classification.getType();
1804     if (getLangOpts().ObjC && NextToken().is(tok::less) &&
1805         (Ty.get()->isObjCObjectType() ||
1806          Ty.get()->isObjCObjectPointerType())) {
1807       // Consume the name.
1808       SourceLocation IdentifierLoc = ConsumeToken();
1809       SourceLocation NewEndLoc;
1810       TypeResult NewType
1811           = parseObjCTypeArgsAndProtocolQualifiers(IdentifierLoc, Ty,
1812                                                    /*consumeLastToken=*/false,
1813                                                    NewEndLoc);
1814       if (NewType.isUsable())
1815         Ty = NewType.get();
1816       else if (Tok.is(tok::eof)) // Nothing to do here, bail out...
1817         return ANK_Error;
1818     }
1819 
1820     Tok.setKind(tok::annot_typename);
1821     setTypeAnnotation(Tok, Ty);
1822     Tok.setAnnotationEndLoc(Tok.getLocation());
1823     Tok.setLocation(BeginLoc);
1824     PP.AnnotateCachedTokens(Tok);
1825     return ANK_Success;
1826   }
1827 
1828   case Sema::NC_OverloadSet:
1829     Tok.setKind(tok::annot_overload_set);
1830     setExprAnnotation(Tok, Classification.getExpression());
1831     Tok.setAnnotationEndLoc(NameLoc);
1832     if (SS.isNotEmpty())
1833       Tok.setLocation(SS.getBeginLoc());
1834     PP.AnnotateCachedTokens(Tok);
1835     return ANK_Success;
1836 
1837   case Sema::NC_NonType:
1838     if (TryAltiVecVectorToken())
1839       // vector has been found as a non-type id when altivec is enabled but
1840       // this is followed by a declaration specifier so this is really the
1841       // altivec vector token.  Leave it unannotated.
1842       break;
1843     Tok.setKind(tok::annot_non_type);
1844     setNonTypeAnnotation(Tok, Classification.getNonTypeDecl());
1845     Tok.setLocation(NameLoc);
1846     Tok.setAnnotationEndLoc(NameLoc);
1847     PP.AnnotateCachedTokens(Tok);
1848     if (SS.isNotEmpty())
1849       AnnotateScopeToken(SS, !WasScopeAnnotation);
1850     return ANK_Success;
1851 
1852   case Sema::NC_UndeclaredNonType:
1853   case Sema::NC_DependentNonType:
1854     Tok.setKind(Classification.getKind() == Sema::NC_UndeclaredNonType
1855                     ? tok::annot_non_type_undeclared
1856                     : tok::annot_non_type_dependent);
1857     setIdentifierAnnotation(Tok, Name);
1858     Tok.setLocation(NameLoc);
1859     Tok.setAnnotationEndLoc(NameLoc);
1860     PP.AnnotateCachedTokens(Tok);
1861     if (SS.isNotEmpty())
1862       AnnotateScopeToken(SS, !WasScopeAnnotation);
1863     return ANK_Success;
1864 
1865   case Sema::NC_TypeTemplate:
1866     if (Next.isNot(tok::less)) {
1867       // This may be a type template being used as a template template argument.
1868       if (SS.isNotEmpty())
1869         AnnotateScopeToken(SS, !WasScopeAnnotation);
1870       return ANK_TemplateName;
1871     }
1872     [[fallthrough]];
1873   case Sema::NC_VarTemplate:
1874   case Sema::NC_FunctionTemplate:
1875   case Sema::NC_UndeclaredTemplate: {
1876     // We have a type, variable or function template followed by '<'.
1877     ConsumeToken();
1878     UnqualifiedId Id;
1879     Id.setIdentifier(Name, NameLoc);
1880     if (AnnotateTemplateIdToken(
1881             TemplateTy::make(Classification.getTemplateName()),
1882             Classification.getTemplateNameKind(), SS, SourceLocation(), Id))
1883       return ANK_Error;
1884     return ANK_Success;
1885   }
1886   case Sema::NC_Concept: {
1887     UnqualifiedId Id;
1888     Id.setIdentifier(Name, NameLoc);
1889     if (Next.is(tok::less))
1890       // We have a concept name followed by '<'. Consume the identifier token so
1891       // we reach the '<' and annotate it.
1892       ConsumeToken();
1893     if (AnnotateTemplateIdToken(
1894             TemplateTy::make(Classification.getTemplateName()),
1895             Classification.getTemplateNameKind(), SS, SourceLocation(), Id,
1896             /*AllowTypeAnnotation=*/false, /*TypeConstraint=*/true))
1897       return ANK_Error;
1898     return ANK_Success;
1899   }
1900   }
1901 
1902   // Unable to classify the name, but maybe we can annotate a scope specifier.
1903   if (SS.isNotEmpty())
1904     AnnotateScopeToken(SS, !WasScopeAnnotation);
1905   return ANK_Unresolved;
1906 }
1907 
TryKeywordIdentFallback(bool DisableKeyword)1908 bool Parser::TryKeywordIdentFallback(bool DisableKeyword) {
1909   assert(Tok.isNot(tok::identifier));
1910   Diag(Tok, diag::ext_keyword_as_ident)
1911     << PP.getSpelling(Tok)
1912     << DisableKeyword;
1913   if (DisableKeyword)
1914     Tok.getIdentifierInfo()->revertTokenIDToIdentifier();
1915   Tok.setKind(tok::identifier);
1916   return true;
1917 }
1918 
1919 /// TryAnnotateTypeOrScopeToken - If the current token position is on a
1920 /// typename (possibly qualified in C++) or a C++ scope specifier not followed
1921 /// by a typename, TryAnnotateTypeOrScopeToken will replace one or more tokens
1922 /// with a single annotation token representing the typename or C++ scope
1923 /// respectively.
1924 /// This simplifies handling of C++ scope specifiers and allows efficient
1925 /// backtracking without the need to re-parse and resolve nested-names and
1926 /// typenames.
1927 /// It will mainly be called when we expect to treat identifiers as typenames
1928 /// (if they are typenames). For example, in C we do not expect identifiers
1929 /// inside expressions to be treated as typenames so it will not be called
1930 /// for expressions in C.
1931 /// The benefit for C/ObjC is that a typename will be annotated and
1932 /// Actions.getTypeName will not be needed to be called again (e.g. getTypeName
1933 /// will not be called twice, once to check whether we have a declaration
1934 /// specifier, and another one to get the actual type inside
1935 /// ParseDeclarationSpecifiers).
1936 ///
1937 /// This returns true if an error occurred.
1938 ///
1939 /// Note that this routine emits an error if you call it with ::new or ::delete
1940 /// as the current tokens, so only call it in contexts where these are invalid.
TryAnnotateTypeOrScopeToken(ImplicitTypenameContext AllowImplicitTypename)1941 bool Parser::TryAnnotateTypeOrScopeToken(
1942     ImplicitTypenameContext AllowImplicitTypename) {
1943   assert((Tok.is(tok::identifier) || Tok.is(tok::coloncolon) ||
1944           Tok.is(tok::kw_typename) || Tok.is(tok::annot_cxxscope) ||
1945           Tok.is(tok::kw_decltype) || Tok.is(tok::annot_template_id) ||
1946           Tok.is(tok::kw___super)) &&
1947          "Cannot be a type or scope token!");
1948 
1949   if (Tok.is(tok::kw_typename)) {
1950     // MSVC lets you do stuff like:
1951     //   typename typedef T_::D D;
1952     //
1953     // We will consume the typedef token here and put it back after we have
1954     // parsed the first identifier, transforming it into something more like:
1955     //   typename T_::D typedef D;
1956     if (getLangOpts().MSVCCompat && NextToken().is(tok::kw_typedef)) {
1957       Token TypedefToken;
1958       PP.Lex(TypedefToken);
1959       bool Result = TryAnnotateTypeOrScopeToken(AllowImplicitTypename);
1960       PP.EnterToken(Tok, /*IsReinject=*/true);
1961       Tok = TypedefToken;
1962       if (!Result)
1963         Diag(Tok.getLocation(), diag::warn_expected_qualified_after_typename);
1964       return Result;
1965     }
1966 
1967     // Parse a C++ typename-specifier, e.g., "typename T::type".
1968     //
1969     //   typename-specifier:
1970     //     'typename' '::' [opt] nested-name-specifier identifier
1971     //     'typename' '::' [opt] nested-name-specifier template [opt]
1972     //            simple-template-id
1973     SourceLocation TypenameLoc = ConsumeToken();
1974     CXXScopeSpec SS;
1975     if (ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/nullptr,
1976                                        /*ObjectHasErrors=*/false,
1977                                        /*EnteringContext=*/false, nullptr,
1978                                        /*IsTypename*/ true))
1979       return true;
1980     if (SS.isEmpty()) {
1981       if (Tok.is(tok::identifier) || Tok.is(tok::annot_template_id) ||
1982           Tok.is(tok::annot_decltype)) {
1983         // Attempt to recover by skipping the invalid 'typename'
1984         if (Tok.is(tok::annot_decltype) ||
1985             (!TryAnnotateTypeOrScopeToken(AllowImplicitTypename) &&
1986              Tok.isAnnotation())) {
1987           unsigned DiagID = diag::err_expected_qualified_after_typename;
1988           // MS compatibility: MSVC permits using known types with typename.
1989           // e.g. "typedef typename T* pointer_type"
1990           if (getLangOpts().MicrosoftExt)
1991             DiagID = diag::warn_expected_qualified_after_typename;
1992           Diag(Tok.getLocation(), DiagID);
1993           return false;
1994         }
1995       }
1996       if (Tok.isEditorPlaceholder())
1997         return true;
1998 
1999       Diag(Tok.getLocation(), diag::err_expected_qualified_after_typename);
2000       return true;
2001     }
2002 
2003     TypeResult Ty;
2004     if (Tok.is(tok::identifier)) {
2005       // FIXME: check whether the next token is '<', first!
2006       Ty = Actions.ActOnTypenameType(getCurScope(), TypenameLoc, SS,
2007                                      *Tok.getIdentifierInfo(),
2008                                      Tok.getLocation());
2009     } else if (Tok.is(tok::annot_template_id)) {
2010       TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
2011       if (!TemplateId->mightBeType()) {
2012         Diag(Tok, diag::err_typename_refers_to_non_type_template)
2013           << Tok.getAnnotationRange();
2014         return true;
2015       }
2016 
2017       ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
2018                                          TemplateId->NumArgs);
2019 
2020       Ty = TemplateId->isInvalid()
2021                ? TypeError()
2022                : Actions.ActOnTypenameType(
2023                      getCurScope(), TypenameLoc, SS, TemplateId->TemplateKWLoc,
2024                      TemplateId->Template, TemplateId->Name,
2025                      TemplateId->TemplateNameLoc, TemplateId->LAngleLoc,
2026                      TemplateArgsPtr, TemplateId->RAngleLoc);
2027     } else {
2028       Diag(Tok, diag::err_expected_type_name_after_typename)
2029         << SS.getRange();
2030       return true;
2031     }
2032 
2033     SourceLocation EndLoc = Tok.getLastLoc();
2034     Tok.setKind(tok::annot_typename);
2035     setTypeAnnotation(Tok, Ty);
2036     Tok.setAnnotationEndLoc(EndLoc);
2037     Tok.setLocation(TypenameLoc);
2038     PP.AnnotateCachedTokens(Tok);
2039     return false;
2040   }
2041 
2042   // Remembers whether the token was originally a scope annotation.
2043   bool WasScopeAnnotation = Tok.is(tok::annot_cxxscope);
2044 
2045   CXXScopeSpec SS;
2046   if (getLangOpts().CPlusPlus)
2047     if (ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/nullptr,
2048                                        /*ObjectHasErrors=*/false,
2049                                        /*EnteringContext*/ false))
2050       return true;
2051 
2052   return TryAnnotateTypeOrScopeTokenAfterScopeSpec(SS, !WasScopeAnnotation,
2053                                                    AllowImplicitTypename);
2054 }
2055 
2056 /// Try to annotate a type or scope token, having already parsed an
2057 /// optional scope specifier. \p IsNewScope should be \c true unless the scope
2058 /// specifier was extracted from an existing tok::annot_cxxscope annotation.
TryAnnotateTypeOrScopeTokenAfterScopeSpec(CXXScopeSpec & SS,bool IsNewScope,ImplicitTypenameContext AllowImplicitTypename)2059 bool Parser::TryAnnotateTypeOrScopeTokenAfterScopeSpec(
2060     CXXScopeSpec &SS, bool IsNewScope,
2061     ImplicitTypenameContext AllowImplicitTypename) {
2062   if (Tok.is(tok::identifier)) {
2063     // Determine whether the identifier is a type name.
2064     if (ParsedType Ty = Actions.getTypeName(
2065             *Tok.getIdentifierInfo(), Tok.getLocation(), getCurScope(), &SS,
2066             false, NextToken().is(tok::period), nullptr,
2067             /*IsCtorOrDtorName=*/false,
2068             /*NonTrivialTypeSourceInfo=*/true,
2069             /*IsClassTemplateDeductionContext=*/true, AllowImplicitTypename)) {
2070       SourceLocation BeginLoc = Tok.getLocation();
2071       if (SS.isNotEmpty()) // it was a C++ qualified type name.
2072         BeginLoc = SS.getBeginLoc();
2073 
2074       /// An Objective-C object type followed by '<' is a specialization of
2075       /// a parameterized class type or a protocol-qualified type.
2076       if (getLangOpts().ObjC && NextToken().is(tok::less) &&
2077           (Ty.get()->isObjCObjectType() ||
2078            Ty.get()->isObjCObjectPointerType())) {
2079         // Consume the name.
2080         SourceLocation IdentifierLoc = ConsumeToken();
2081         SourceLocation NewEndLoc;
2082         TypeResult NewType
2083           = parseObjCTypeArgsAndProtocolQualifiers(IdentifierLoc, Ty,
2084                                                    /*consumeLastToken=*/false,
2085                                                    NewEndLoc);
2086         if (NewType.isUsable())
2087           Ty = NewType.get();
2088         else if (Tok.is(tok::eof)) // Nothing to do here, bail out...
2089           return false;
2090       }
2091 
2092       // This is a typename. Replace the current token in-place with an
2093       // annotation type token.
2094       Tok.setKind(tok::annot_typename);
2095       setTypeAnnotation(Tok, Ty);
2096       Tok.setAnnotationEndLoc(Tok.getLocation());
2097       Tok.setLocation(BeginLoc);
2098 
2099       // In case the tokens were cached, have Preprocessor replace
2100       // them with the annotation token.
2101       PP.AnnotateCachedTokens(Tok);
2102       return false;
2103     }
2104 
2105     if (!getLangOpts().CPlusPlus) {
2106       // If we're in C, the only place we can have :: tokens is C2x
2107       // attribute which is parsed elsewhere. If the identifier is not a type,
2108       // then it can't be scope either, just early exit.
2109       return false;
2110     }
2111 
2112     // If this is a template-id, annotate with a template-id or type token.
2113     // FIXME: This appears to be dead code. We already have formed template-id
2114     // tokens when parsing the scope specifier; this can never form a new one.
2115     if (NextToken().is(tok::less)) {
2116       TemplateTy Template;
2117       UnqualifiedId TemplateName;
2118       TemplateName.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
2119       bool MemberOfUnknownSpecialization;
2120       if (TemplateNameKind TNK = Actions.isTemplateName(
2121               getCurScope(), SS,
2122               /*hasTemplateKeyword=*/false, TemplateName,
2123               /*ObjectType=*/nullptr, /*EnteringContext*/false, Template,
2124               MemberOfUnknownSpecialization)) {
2125         // Only annotate an undeclared template name as a template-id if the
2126         // following tokens have the form of a template argument list.
2127         if (TNK != TNK_Undeclared_template ||
2128             isTemplateArgumentList(1) != TPResult::False) {
2129           // Consume the identifier.
2130           ConsumeToken();
2131           if (AnnotateTemplateIdToken(Template, TNK, SS, SourceLocation(),
2132                                       TemplateName)) {
2133             // If an unrecoverable error occurred, we need to return true here,
2134             // because the token stream is in a damaged state.  We may not
2135             // return a valid identifier.
2136             return true;
2137           }
2138         }
2139       }
2140     }
2141 
2142     // The current token, which is either an identifier or a
2143     // template-id, is not part of the annotation. Fall through to
2144     // push that token back into the stream and complete the C++ scope
2145     // specifier annotation.
2146   }
2147 
2148   if (Tok.is(tok::annot_template_id)) {
2149     TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
2150     if (TemplateId->Kind == TNK_Type_template) {
2151       // A template-id that refers to a type was parsed into a
2152       // template-id annotation in a context where we weren't allowed
2153       // to produce a type annotation token. Update the template-id
2154       // annotation token to a type annotation token now.
2155       AnnotateTemplateIdTokenAsType(SS, AllowImplicitTypename);
2156       return false;
2157     }
2158   }
2159 
2160   if (SS.isEmpty())
2161     return false;
2162 
2163   // A C++ scope specifier that isn't followed by a typename.
2164   AnnotateScopeToken(SS, IsNewScope);
2165   return false;
2166 }
2167 
2168 /// TryAnnotateScopeToken - Like TryAnnotateTypeOrScopeToken but only
2169 /// annotates C++ scope specifiers and template-ids.  This returns
2170 /// true if there was an error that could not be recovered from.
2171 ///
2172 /// Note that this routine emits an error if you call it with ::new or ::delete
2173 /// as the current tokens, so only call it in contexts where these are invalid.
TryAnnotateCXXScopeToken(bool EnteringContext)2174 bool Parser::TryAnnotateCXXScopeToken(bool EnteringContext) {
2175   assert(getLangOpts().CPlusPlus &&
2176          "Call sites of this function should be guarded by checking for C++");
2177   assert(MightBeCXXScopeToken() && "Cannot be a type or scope token!");
2178 
2179   CXXScopeSpec SS;
2180   if (ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/nullptr,
2181                                      /*ObjectHasErrors=*/false,
2182                                      EnteringContext))
2183     return true;
2184   if (SS.isEmpty())
2185     return false;
2186 
2187   AnnotateScopeToken(SS, true);
2188   return false;
2189 }
2190 
isTokenEqualOrEqualTypo()2191 bool Parser::isTokenEqualOrEqualTypo() {
2192   tok::TokenKind Kind = Tok.getKind();
2193   switch (Kind) {
2194   default:
2195     return false;
2196   case tok::ampequal:            // &=
2197   case tok::starequal:           // *=
2198   case tok::plusequal:           // +=
2199   case tok::minusequal:          // -=
2200   case tok::exclaimequal:        // !=
2201   case tok::slashequal:          // /=
2202   case tok::percentequal:        // %=
2203   case tok::lessequal:           // <=
2204   case tok::lesslessequal:       // <<=
2205   case tok::greaterequal:        // >=
2206   case tok::greatergreaterequal: // >>=
2207   case tok::caretequal:          // ^=
2208   case tok::pipeequal:           // |=
2209   case tok::equalequal:          // ==
2210     Diag(Tok, diag::err_invalid_token_after_declarator_suggest_equal)
2211         << Kind
2212         << FixItHint::CreateReplacement(SourceRange(Tok.getLocation()), "=");
2213     [[fallthrough]];
2214   case tok::equal:
2215     return true;
2216   }
2217 }
2218 
handleUnexpectedCodeCompletionToken()2219 SourceLocation Parser::handleUnexpectedCodeCompletionToken() {
2220   assert(Tok.is(tok::code_completion));
2221   PrevTokLocation = Tok.getLocation();
2222 
2223   for (Scope *S = getCurScope(); S; S = S->getParent()) {
2224     if (S->isFunctionScope()) {
2225       cutOffParsing();
2226       Actions.CodeCompleteOrdinaryName(getCurScope(),
2227                                        Sema::PCC_RecoveryInFunction);
2228       return PrevTokLocation;
2229     }
2230 
2231     if (S->isClassScope()) {
2232       cutOffParsing();
2233       Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Class);
2234       return PrevTokLocation;
2235     }
2236   }
2237 
2238   cutOffParsing();
2239   Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Namespace);
2240   return PrevTokLocation;
2241 }
2242 
2243 // Code-completion pass-through functions
2244 
CodeCompleteDirective(bool InConditional)2245 void Parser::CodeCompleteDirective(bool InConditional) {
2246   Actions.CodeCompletePreprocessorDirective(InConditional);
2247 }
2248 
CodeCompleteInConditionalExclusion()2249 void Parser::CodeCompleteInConditionalExclusion() {
2250   Actions.CodeCompleteInPreprocessorConditionalExclusion(getCurScope());
2251 }
2252 
CodeCompleteMacroName(bool IsDefinition)2253 void Parser::CodeCompleteMacroName(bool IsDefinition) {
2254   Actions.CodeCompletePreprocessorMacroName(IsDefinition);
2255 }
2256 
CodeCompletePreprocessorExpression()2257 void Parser::CodeCompletePreprocessorExpression() {
2258   Actions.CodeCompletePreprocessorExpression();
2259 }
2260 
CodeCompleteMacroArgument(IdentifierInfo * Macro,MacroInfo * MacroInfo,unsigned ArgumentIndex)2261 void Parser::CodeCompleteMacroArgument(IdentifierInfo *Macro,
2262                                        MacroInfo *MacroInfo,
2263                                        unsigned ArgumentIndex) {
2264   Actions.CodeCompletePreprocessorMacroArgument(getCurScope(), Macro, MacroInfo,
2265                                                 ArgumentIndex);
2266 }
2267 
CodeCompleteIncludedFile(llvm::StringRef Dir,bool IsAngled)2268 void Parser::CodeCompleteIncludedFile(llvm::StringRef Dir, bool IsAngled) {
2269   Actions.CodeCompleteIncludedFile(Dir, IsAngled);
2270 }
2271 
CodeCompleteNaturalLanguage()2272 void Parser::CodeCompleteNaturalLanguage() {
2273   Actions.CodeCompleteNaturalLanguage();
2274 }
2275 
ParseMicrosoftIfExistsCondition(IfExistsCondition & Result)2276 bool Parser::ParseMicrosoftIfExistsCondition(IfExistsCondition& Result) {
2277   assert((Tok.is(tok::kw___if_exists) || Tok.is(tok::kw___if_not_exists)) &&
2278          "Expected '__if_exists' or '__if_not_exists'");
2279   Result.IsIfExists = Tok.is(tok::kw___if_exists);
2280   Result.KeywordLoc = ConsumeToken();
2281 
2282   BalancedDelimiterTracker T(*this, tok::l_paren);
2283   if (T.consumeOpen()) {
2284     Diag(Tok, diag::err_expected_lparen_after)
2285       << (Result.IsIfExists? "__if_exists" : "__if_not_exists");
2286     return true;
2287   }
2288 
2289   // Parse nested-name-specifier.
2290   if (getLangOpts().CPlusPlus)
2291     ParseOptionalCXXScopeSpecifier(Result.SS, /*ObjectType=*/nullptr,
2292                                    /*ObjectHasErrors=*/false,
2293                                    /*EnteringContext=*/false);
2294 
2295   // Check nested-name specifier.
2296   if (Result.SS.isInvalid()) {
2297     T.skipToEnd();
2298     return true;
2299   }
2300 
2301   // Parse the unqualified-id.
2302   SourceLocation TemplateKWLoc; // FIXME: parsed, but unused.
2303   if (ParseUnqualifiedId(Result.SS, /*ObjectType=*/nullptr,
2304                          /*ObjectHadErrors=*/false, /*EnteringContext*/ false,
2305                          /*AllowDestructorName*/ true,
2306                          /*AllowConstructorName*/ true,
2307                          /*AllowDeductionGuide*/ false, &TemplateKWLoc,
2308                          Result.Name)) {
2309     T.skipToEnd();
2310     return true;
2311   }
2312 
2313   if (T.consumeClose())
2314     return true;
2315 
2316   // Check if the symbol exists.
2317   switch (Actions.CheckMicrosoftIfExistsSymbol(getCurScope(), Result.KeywordLoc,
2318                                                Result.IsIfExists, Result.SS,
2319                                                Result.Name)) {
2320   case Sema::IER_Exists:
2321     Result.Behavior = Result.IsIfExists ? IEB_Parse : IEB_Skip;
2322     break;
2323 
2324   case Sema::IER_DoesNotExist:
2325     Result.Behavior = !Result.IsIfExists ? IEB_Parse : IEB_Skip;
2326     break;
2327 
2328   case Sema::IER_Dependent:
2329     Result.Behavior = IEB_Dependent;
2330     break;
2331 
2332   case Sema::IER_Error:
2333     return true;
2334   }
2335 
2336   return false;
2337 }
2338 
ParseMicrosoftIfExistsExternalDeclaration()2339 void Parser::ParseMicrosoftIfExistsExternalDeclaration() {
2340   IfExistsCondition Result;
2341   if (ParseMicrosoftIfExistsCondition(Result))
2342     return;
2343 
2344   BalancedDelimiterTracker Braces(*this, tok::l_brace);
2345   if (Braces.consumeOpen()) {
2346     Diag(Tok, diag::err_expected) << tok::l_brace;
2347     return;
2348   }
2349 
2350   switch (Result.Behavior) {
2351   case IEB_Parse:
2352     // Parse declarations below.
2353     break;
2354 
2355   case IEB_Dependent:
2356     llvm_unreachable("Cannot have a dependent external declaration");
2357 
2358   case IEB_Skip:
2359     Braces.skipToEnd();
2360     return;
2361   }
2362 
2363   // Parse the declarations.
2364   // FIXME: Support module import within __if_exists?
2365   while (Tok.isNot(tok::r_brace) && !isEofOrEom()) {
2366     ParsedAttributes Attrs(AttrFactory);
2367     MaybeParseCXX11Attributes(Attrs);
2368     ParsedAttributes EmptyDeclSpecAttrs(AttrFactory);
2369     DeclGroupPtrTy Result = ParseExternalDeclaration(Attrs, EmptyDeclSpecAttrs);
2370     if (Result && !getCurScope()->getParent())
2371       Actions.getASTConsumer().HandleTopLevelDecl(Result.get());
2372   }
2373   Braces.consumeClose();
2374 }
2375 
2376 /// Parse a declaration beginning with the 'module' keyword or C++20
2377 /// context-sensitive keyword (optionally preceded by 'export').
2378 ///
2379 ///   module-declaration:   [Modules TS + P0629R0]
2380 ///     'export'[opt] 'module' module-name attribute-specifier-seq[opt] ';'
2381 ///
2382 ///   global-module-fragment:  [C++2a]
2383 ///     'module' ';' top-level-declaration-seq[opt]
2384 ///   module-declaration:      [C++2a]
2385 ///     'export'[opt] 'module' module-name module-partition[opt]
2386 ///            attribute-specifier-seq[opt] ';'
2387 ///   private-module-fragment: [C++2a]
2388 ///     'module' ':' 'private' ';' top-level-declaration-seq[opt]
2389 Parser::DeclGroupPtrTy
ParseModuleDecl(Sema::ModuleImportState & ImportState)2390 Parser::ParseModuleDecl(Sema::ModuleImportState &ImportState) {
2391   SourceLocation StartLoc = Tok.getLocation();
2392 
2393   Sema::ModuleDeclKind MDK = TryConsumeToken(tok::kw_export)
2394                                  ? Sema::ModuleDeclKind::Interface
2395                                  : Sema::ModuleDeclKind::Implementation;
2396 
2397   assert(
2398       (Tok.is(tok::kw_module) ||
2399        (Tok.is(tok::identifier) && Tok.getIdentifierInfo() == Ident_module)) &&
2400       "not a module declaration");
2401   SourceLocation ModuleLoc = ConsumeToken();
2402 
2403   // Attributes appear after the module name, not before.
2404   // FIXME: Suggest moving the attributes later with a fixit.
2405   DiagnoseAndSkipCXX11Attributes();
2406 
2407   // Parse a global-module-fragment, if present.
2408   if (getLangOpts().CPlusPlusModules && Tok.is(tok::semi)) {
2409     SourceLocation SemiLoc = ConsumeToken();
2410     if (ImportState != Sema::ModuleImportState::FirstDecl) {
2411       Diag(StartLoc, diag::err_global_module_introducer_not_at_start)
2412         << SourceRange(StartLoc, SemiLoc);
2413       return nullptr;
2414     }
2415     if (MDK == Sema::ModuleDeclKind::Interface) {
2416       Diag(StartLoc, diag::err_module_fragment_exported)
2417         << /*global*/0 << FixItHint::CreateRemoval(StartLoc);
2418     }
2419     ImportState = Sema::ModuleImportState::GlobalFragment;
2420     return Actions.ActOnGlobalModuleFragmentDecl(ModuleLoc);
2421   }
2422 
2423   // Parse a private-module-fragment, if present.
2424   if (getLangOpts().CPlusPlusModules && Tok.is(tok::colon) &&
2425       NextToken().is(tok::kw_private)) {
2426     if (MDK == Sema::ModuleDeclKind::Interface) {
2427       Diag(StartLoc, diag::err_module_fragment_exported)
2428         << /*private*/1 << FixItHint::CreateRemoval(StartLoc);
2429     }
2430     ConsumeToken();
2431     SourceLocation PrivateLoc = ConsumeToken();
2432     DiagnoseAndSkipCXX11Attributes();
2433     ExpectAndConsumeSemi(diag::err_private_module_fragment_expected_semi);
2434     ImportState = ImportState == Sema::ModuleImportState::ImportAllowed
2435                       ? Sema::ModuleImportState::PrivateFragmentImportAllowed
2436                       : Sema::ModuleImportState::PrivateFragmentImportFinished;
2437     return Actions.ActOnPrivateModuleFragmentDecl(ModuleLoc, PrivateLoc);
2438   }
2439 
2440   SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> Path;
2441   if (ParseModuleName(ModuleLoc, Path, /*IsImport*/ false))
2442     return nullptr;
2443 
2444   // Parse the optional module-partition.
2445   SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> Partition;
2446   if (Tok.is(tok::colon)) {
2447     SourceLocation ColonLoc = ConsumeToken();
2448     if (!getLangOpts().CPlusPlusModules)
2449       Diag(ColonLoc, diag::err_unsupported_module_partition)
2450           << SourceRange(ColonLoc, Partition.back().second);
2451     // Recover by ignoring the partition name.
2452     else if (ParseModuleName(ModuleLoc, Partition, /*IsImport*/ false))
2453       return nullptr;
2454   }
2455 
2456   // We don't support any module attributes yet; just parse them and diagnose.
2457   ParsedAttributes Attrs(AttrFactory);
2458   MaybeParseCXX11Attributes(Attrs);
2459   ProhibitCXX11Attributes(Attrs, diag::err_attribute_not_module_attr,
2460                           /*DiagnoseEmptyAttrs=*/false,
2461                           /*WarnOnUnknownAttrs=*/true);
2462 
2463   ExpectAndConsumeSemi(diag::err_module_expected_semi);
2464 
2465   return Actions.ActOnModuleDecl(StartLoc, ModuleLoc, MDK, Path, Partition,
2466                                  ImportState);
2467 }
2468 
2469 /// Parse a module import declaration. This is essentially the same for
2470 /// Objective-C and C++20 except for the leading '@' (in ObjC) and the
2471 /// trailing optional attributes (in C++).
2472 ///
2473 /// [ObjC]  @import declaration:
2474 ///           '@' 'import' module-name ';'
2475 /// [ModTS] module-import-declaration:
2476 ///           'import' module-name attribute-specifier-seq[opt] ';'
2477 /// [C++20] module-import-declaration:
2478 ///           'export'[opt] 'import' module-name
2479 ///                   attribute-specifier-seq[opt] ';'
2480 ///           'export'[opt] 'import' module-partition
2481 ///                   attribute-specifier-seq[opt] ';'
2482 ///           'export'[opt] 'import' header-name
2483 ///                   attribute-specifier-seq[opt] ';'
ParseModuleImport(SourceLocation AtLoc,Sema::ModuleImportState & ImportState)2484 Decl *Parser::ParseModuleImport(SourceLocation AtLoc,
2485                                 Sema::ModuleImportState &ImportState) {
2486   SourceLocation StartLoc = AtLoc.isInvalid() ? Tok.getLocation() : AtLoc;
2487 
2488   SourceLocation ExportLoc;
2489   TryConsumeToken(tok::kw_export, ExportLoc);
2490 
2491   assert((AtLoc.isInvalid() ? Tok.isOneOf(tok::kw_import, tok::identifier)
2492                             : Tok.isObjCAtKeyword(tok::objc_import)) &&
2493          "Improper start to module import");
2494   bool IsObjCAtImport = Tok.isObjCAtKeyword(tok::objc_import);
2495   SourceLocation ImportLoc = ConsumeToken();
2496 
2497   // For C++20 modules, we can have "name" or ":Partition name" as valid input.
2498   SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> Path;
2499   bool IsPartition = false;
2500   Module *HeaderUnit = nullptr;
2501   if (Tok.is(tok::header_name)) {
2502     // This is a header import that the preprocessor decided we should skip
2503     // because it was malformed in some way. Parse and ignore it; it's already
2504     // been diagnosed.
2505     ConsumeToken();
2506   } else if (Tok.is(tok::annot_header_unit)) {
2507     // This is a header import that the preprocessor mapped to a module import.
2508     HeaderUnit = reinterpret_cast<Module *>(Tok.getAnnotationValue());
2509     ConsumeAnnotationToken();
2510   } else if (Tok.is(tok::colon)) {
2511     SourceLocation ColonLoc = ConsumeToken();
2512     if (!getLangOpts().CPlusPlusModules)
2513       Diag(ColonLoc, diag::err_unsupported_module_partition)
2514           << SourceRange(ColonLoc, Path.back().second);
2515     // Recover by leaving partition empty.
2516     else if (ParseModuleName(ColonLoc, Path, /*IsImport*/ true))
2517       return nullptr;
2518     else
2519       IsPartition = true;
2520   } else {
2521     if (ParseModuleName(ImportLoc, Path, /*IsImport*/ true))
2522       return nullptr;
2523   }
2524 
2525   ParsedAttributes Attrs(AttrFactory);
2526   MaybeParseCXX11Attributes(Attrs);
2527   // We don't support any module import attributes yet.
2528   ProhibitCXX11Attributes(Attrs, diag::err_attribute_not_import_attr,
2529                           /*DiagnoseEmptyAttrs=*/false,
2530                           /*WarnOnUnknownAttrs=*/true);
2531 
2532   if (PP.hadModuleLoaderFatalFailure()) {
2533     // With a fatal failure in the module loader, we abort parsing.
2534     cutOffParsing();
2535     return nullptr;
2536   }
2537 
2538   // Diagnose mis-imports.
2539   bool SeenError = true;
2540   switch (ImportState) {
2541   case Sema::ModuleImportState::ImportAllowed:
2542     SeenError = false;
2543     break;
2544   case Sema::ModuleImportState::FirstDecl:
2545   case Sema::ModuleImportState::NotACXX20Module:
2546     // We can only import a partition within a module purview.
2547     if (IsPartition)
2548       Diag(ImportLoc, diag::err_partition_import_outside_module);
2549     else
2550       SeenError = false;
2551     break;
2552   case Sema::ModuleImportState::GlobalFragment:
2553   case Sema::ModuleImportState::PrivateFragmentImportAllowed:
2554     // We can only have pre-processor directives in the global module fragment
2555     // which allows pp-import, but not of a partition (since the global module
2556     // does not have partitions).
2557     // We cannot import a partition into a private module fragment, since
2558     // [module.private.frag]/1 disallows private module fragments in a multi-
2559     // TU module.
2560     if (IsPartition || (HeaderUnit && HeaderUnit->Kind !=
2561                                           Module::ModuleKind::ModuleHeaderUnit))
2562       Diag(ImportLoc, diag::err_import_in_wrong_fragment)
2563           << IsPartition
2564           << (ImportState == Sema::ModuleImportState::GlobalFragment ? 0 : 1);
2565     else
2566       SeenError = false;
2567     break;
2568   case Sema::ModuleImportState::ImportFinished:
2569   case Sema::ModuleImportState::PrivateFragmentImportFinished:
2570     if (getLangOpts().CPlusPlusModules)
2571       Diag(ImportLoc, diag::err_import_not_allowed_here);
2572     else
2573       SeenError = false;
2574     break;
2575   }
2576   if (SeenError) {
2577     ExpectAndConsumeSemi(diag::err_module_expected_semi);
2578     return nullptr;
2579   }
2580 
2581   DeclResult Import;
2582   if (HeaderUnit)
2583     Import =
2584         Actions.ActOnModuleImport(StartLoc, ExportLoc, ImportLoc, HeaderUnit);
2585   else if (!Path.empty())
2586     Import = Actions.ActOnModuleImport(StartLoc, ExportLoc, ImportLoc, Path,
2587                                        IsPartition);
2588   ExpectAndConsumeSemi(diag::err_module_expected_semi);
2589   if (Import.isInvalid())
2590     return nullptr;
2591 
2592   // Using '@import' in framework headers requires modules to be enabled so that
2593   // the header is parseable. Emit a warning to make the user aware.
2594   if (IsObjCAtImport && AtLoc.isValid()) {
2595     auto &SrcMgr = PP.getSourceManager();
2596     auto FE = SrcMgr.getFileEntryRefForID(SrcMgr.getFileID(AtLoc));
2597     if (FE && llvm::sys::path::parent_path(FE->getDir().getName())
2598                   .endswith(".framework"))
2599       Diags.Report(AtLoc, diag::warn_atimport_in_framework_header);
2600   }
2601 
2602   return Import.get();
2603 }
2604 
2605 /// Parse a C++ Modules TS / Objective-C module name (both forms use the same
2606 /// grammar).
2607 ///
2608 ///         module-name:
2609 ///           module-name-qualifier[opt] identifier
2610 ///         module-name-qualifier:
2611 ///           module-name-qualifier[opt] identifier '.'
ParseModuleName(SourceLocation UseLoc,SmallVectorImpl<std::pair<IdentifierInfo *,SourceLocation>> & Path,bool IsImport)2612 bool Parser::ParseModuleName(
2613     SourceLocation UseLoc,
2614     SmallVectorImpl<std::pair<IdentifierInfo *, SourceLocation>> &Path,
2615     bool IsImport) {
2616   // Parse the module path.
2617   while (true) {
2618     if (!Tok.is(tok::identifier)) {
2619       if (Tok.is(tok::code_completion)) {
2620         cutOffParsing();
2621         Actions.CodeCompleteModuleImport(UseLoc, Path);
2622         return true;
2623       }
2624 
2625       Diag(Tok, diag::err_module_expected_ident) << IsImport;
2626       SkipUntil(tok::semi);
2627       return true;
2628     }
2629 
2630     // Record this part of the module path.
2631     Path.push_back(std::make_pair(Tok.getIdentifierInfo(), Tok.getLocation()));
2632     ConsumeToken();
2633 
2634     if (Tok.isNot(tok::period))
2635       return false;
2636 
2637     ConsumeToken();
2638   }
2639 }
2640 
2641 /// Try recover parser when module annotation appears where it must not
2642 /// be found.
2643 /// \returns false if the recover was successful and parsing may be continued, or
2644 /// true if parser must bail out to top level and handle the token there.
parseMisplacedModuleImport()2645 bool Parser::parseMisplacedModuleImport() {
2646   while (true) {
2647     switch (Tok.getKind()) {
2648     case tok::annot_module_end:
2649       // If we recovered from a misplaced module begin, we expect to hit a
2650       // misplaced module end too. Stay in the current context when this
2651       // happens.
2652       if (MisplacedModuleBeginCount) {
2653         --MisplacedModuleBeginCount;
2654         Actions.ActOnModuleEnd(Tok.getLocation(),
2655                                reinterpret_cast<Module *>(
2656                                    Tok.getAnnotationValue()));
2657         ConsumeAnnotationToken();
2658         continue;
2659       }
2660       // Inform caller that recovery failed, the error must be handled at upper
2661       // level. This will generate the desired "missing '}' at end of module"
2662       // diagnostics on the way out.
2663       return true;
2664     case tok::annot_module_begin:
2665       // Recover by entering the module (Sema will diagnose).
2666       Actions.ActOnModuleBegin(Tok.getLocation(),
2667                                reinterpret_cast<Module *>(
2668                                    Tok.getAnnotationValue()));
2669       ConsumeAnnotationToken();
2670       ++MisplacedModuleBeginCount;
2671       continue;
2672     case tok::annot_module_include:
2673       // Module import found where it should not be, for instance, inside a
2674       // namespace. Recover by importing the module.
2675       Actions.ActOnModuleInclude(Tok.getLocation(),
2676                                  reinterpret_cast<Module *>(
2677                                      Tok.getAnnotationValue()));
2678       ConsumeAnnotationToken();
2679       // If there is another module import, process it.
2680       continue;
2681     default:
2682       return false;
2683     }
2684   }
2685   return false;
2686 }
2687 
diagnoseOverflow()2688 bool BalancedDelimiterTracker::diagnoseOverflow() {
2689   P.Diag(P.Tok, diag::err_bracket_depth_exceeded)
2690     << P.getLangOpts().BracketDepth;
2691   P.Diag(P.Tok, diag::note_bracket_depth);
2692   P.cutOffParsing();
2693   return true;
2694 }
2695 
expectAndConsume(unsigned DiagID,const char * Msg,tok::TokenKind SkipToTok)2696 bool BalancedDelimiterTracker::expectAndConsume(unsigned DiagID,
2697                                                 const char *Msg,
2698                                                 tok::TokenKind SkipToTok) {
2699   LOpen = P.Tok.getLocation();
2700   if (P.ExpectAndConsume(Kind, DiagID, Msg)) {
2701     if (SkipToTok != tok::unknown)
2702       P.SkipUntil(SkipToTok, Parser::StopAtSemi);
2703     return true;
2704   }
2705 
2706   if (getDepth() < P.getLangOpts().BracketDepth)
2707     return false;
2708 
2709   return diagnoseOverflow();
2710 }
2711 
diagnoseMissingClose()2712 bool BalancedDelimiterTracker::diagnoseMissingClose() {
2713   assert(!P.Tok.is(Close) && "Should have consumed closing delimiter");
2714 
2715   if (P.Tok.is(tok::annot_module_end))
2716     P.Diag(P.Tok, diag::err_missing_before_module_end) << Close;
2717   else
2718     P.Diag(P.Tok, diag::err_expected) << Close;
2719   P.Diag(LOpen, diag::note_matching) << Kind;
2720 
2721   // If we're not already at some kind of closing bracket, skip to our closing
2722   // token.
2723   if (P.Tok.isNot(tok::r_paren) && P.Tok.isNot(tok::r_brace) &&
2724       P.Tok.isNot(tok::r_square) &&
2725       P.SkipUntil(Close, FinalToken,
2726                   Parser::StopAtSemi | Parser::StopBeforeMatch) &&
2727       P.Tok.is(Close))
2728     LClose = P.ConsumeAnyToken();
2729   return true;
2730 }
2731 
skipToEnd()2732 void BalancedDelimiterTracker::skipToEnd() {
2733   P.SkipUntil(Close, Parser::StopBeforeMatch);
2734   consumeClose();
2735 }
2736