1//===--- Parser.cpp - C Language Family Parser ----------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file implements the Parser interfaces.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Parse/Parser.h"
15#include "RAIIObjectsForParser.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/DeclTemplate.h"
19#include "clang/Parse/ParseDiagnostic.h"
20#include "clang/Sema/DeclSpec.h"
21#include "clang/Sema/ParsedTemplate.h"
22#include "clang/Sema/Scope.h"
23#include "llvm/Support/raw_ostream.h"
24using namespace clang;
25
26
27namespace {
28/// \brief A comment handler that passes comments found by the preprocessor
29/// to the parser action.
30class ActionCommentHandler : public CommentHandler {
31  Sema &S;
32
33public:
34  explicit ActionCommentHandler(Sema &S) : S(S) { }
35
36  bool HandleComment(Preprocessor &PP, SourceRange Comment) override {
37    S.ActOnComment(Comment);
38    return false;
39  }
40};
41
42/// \brief RAIIObject to destroy the contents of a SmallVector of
43/// TemplateIdAnnotation pointers and clear the vector.
44class DestroyTemplateIdAnnotationsRAIIObj {
45  SmallVectorImpl<TemplateIdAnnotation *> &Container;
46
47public:
48  DestroyTemplateIdAnnotationsRAIIObj(
49      SmallVectorImpl<TemplateIdAnnotation *> &Container)
50      : Container(Container) {}
51
52  ~DestroyTemplateIdAnnotationsRAIIObj() {
53    for (SmallVectorImpl<TemplateIdAnnotation *>::iterator I =
54             Container.begin(),
55                                                           E = Container.end();
56         I != E; ++I)
57      (*I)->Destroy();
58    Container.clear();
59  }
60};
61} // end anonymous namespace
62
63IdentifierInfo *Parser::getSEHExceptKeyword() {
64  // __except is accepted as a (contextual) keyword
65  if (!Ident__except && (getLangOpts().MicrosoftExt || getLangOpts().Borland))
66    Ident__except = PP.getIdentifierInfo("__except");
67
68  return Ident__except;
69}
70
71Parser::Parser(Preprocessor &pp, Sema &actions, bool skipFunctionBodies)
72  : PP(pp), Actions(actions), Diags(PP.getDiagnostics()),
73    GreaterThanIsOperator(true), ColonIsSacred(false),
74    InMessageExpression(false), TemplateParameterDepth(0),
75    ParsingInObjCContainer(false) {
76  SkipFunctionBodies = pp.isCodeCompletionEnabled() || skipFunctionBodies;
77  Tok.startToken();
78  Tok.setKind(tok::eof);
79  Actions.CurScope = nullptr;
80  NumCachedScopes = 0;
81  ParenCount = BracketCount = BraceCount = 0;
82  CurParsedObjCImpl = nullptr;
83
84  // Add #pragma handlers. These are removed and destroyed in the
85  // destructor.
86  initializePragmaHandlers();
87
88  CommentSemaHandler.reset(new ActionCommentHandler(actions));
89  PP.addCommentHandler(CommentSemaHandler.get());
90
91  PP.setCodeCompletionHandler(*this);
92}
93
94DiagnosticBuilder Parser::Diag(SourceLocation Loc, unsigned DiagID) {
95  return Diags.Report(Loc, DiagID);
96}
97
98DiagnosticBuilder Parser::Diag(const Token &Tok, unsigned DiagID) {
99  return Diag(Tok.getLocation(), DiagID);
100}
101
102/// \brief Emits a diagnostic suggesting parentheses surrounding a
103/// given range.
104///
105/// \param Loc The location where we'll emit the diagnostic.
106/// \param DK The kind of diagnostic to emit.
107/// \param ParenRange Source range enclosing code that should be parenthesized.
108void Parser::SuggestParentheses(SourceLocation Loc, unsigned DK,
109                                SourceRange ParenRange) {
110  SourceLocation EndLoc = PP.getLocForEndOfToken(ParenRange.getEnd());
111  if (!ParenRange.getEnd().isFileID() || EndLoc.isInvalid()) {
112    // We can't display the parentheses, so just dig the
113    // warning/error and return.
114    Diag(Loc, DK);
115    return;
116  }
117
118  Diag(Loc, DK)
119    << FixItHint::CreateInsertion(ParenRange.getBegin(), "(")
120    << FixItHint::CreateInsertion(EndLoc, ")");
121}
122
123static bool IsCommonTypo(tok::TokenKind ExpectedTok, const Token &Tok) {
124  switch (ExpectedTok) {
125  case tok::semi:
126    return Tok.is(tok::colon) || Tok.is(tok::comma); // : or , for ;
127  default: return false;
128  }
129}
130
131bool Parser::ExpectAndConsume(tok::TokenKind ExpectedTok, unsigned DiagID,
132                              StringRef Msg) {
133  if (Tok.is(ExpectedTok) || Tok.is(tok::code_completion)) {
134    ConsumeAnyToken();
135    return false;
136  }
137
138  // Detect common single-character typos and resume.
139  if (IsCommonTypo(ExpectedTok, Tok)) {
140    SourceLocation Loc = Tok.getLocation();
141    {
142      DiagnosticBuilder DB = Diag(Loc, DiagID);
143      DB << FixItHint::CreateReplacement(
144                SourceRange(Loc), tok::getPunctuatorSpelling(ExpectedTok));
145      if (DiagID == diag::err_expected)
146        DB << ExpectedTok;
147      else if (DiagID == diag::err_expected_after)
148        DB << Msg << ExpectedTok;
149      else
150        DB << Msg;
151    }
152
153    // Pretend there wasn't a problem.
154    ConsumeAnyToken();
155    return false;
156  }
157
158  SourceLocation EndLoc = PP.getLocForEndOfToken(PrevTokLocation);
159  const char *Spelling = nullptr;
160  if (EndLoc.isValid())
161    Spelling = tok::getPunctuatorSpelling(ExpectedTok);
162
163  DiagnosticBuilder DB =
164      Spelling
165          ? Diag(EndLoc, DiagID) << FixItHint::CreateInsertion(EndLoc, Spelling)
166          : Diag(Tok, DiagID);
167  if (DiagID == diag::err_expected)
168    DB << ExpectedTok;
169  else if (DiagID == diag::err_expected_after)
170    DB << Msg << ExpectedTok;
171  else
172    DB << Msg;
173
174  return true;
175}
176
177bool Parser::ExpectAndConsumeSemi(unsigned DiagID) {
178  if (TryConsumeToken(tok::semi))
179    return false;
180
181  if (Tok.is(tok::code_completion)) {
182    handleUnexpectedCodeCompletionToken();
183    return false;
184  }
185
186  if ((Tok.is(tok::r_paren) || Tok.is(tok::r_square)) &&
187      NextToken().is(tok::semi)) {
188    Diag(Tok, diag::err_extraneous_token_before_semi)
189      << PP.getSpelling(Tok)
190      << FixItHint::CreateRemoval(Tok.getLocation());
191    ConsumeAnyToken(); // The ')' or ']'.
192    ConsumeToken(); // The ';'.
193    return false;
194  }
195
196  return ExpectAndConsume(tok::semi, DiagID);
197}
198
199void Parser::ConsumeExtraSemi(ExtraSemiKind Kind, unsigned TST) {
200  if (!Tok.is(tok::semi)) return;
201
202  bool HadMultipleSemis = false;
203  SourceLocation StartLoc = Tok.getLocation();
204  SourceLocation EndLoc = Tok.getLocation();
205  ConsumeToken();
206
207  while ((Tok.is(tok::semi) && !Tok.isAtStartOfLine())) {
208    HadMultipleSemis = true;
209    EndLoc = Tok.getLocation();
210    ConsumeToken();
211  }
212
213  // C++11 allows extra semicolons at namespace scope, but not in any of the
214  // other contexts.
215  if (Kind == OutsideFunction && getLangOpts().CPlusPlus) {
216    if (getLangOpts().CPlusPlus11)
217      Diag(StartLoc, diag::warn_cxx98_compat_top_level_semi)
218          << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
219    else
220      Diag(StartLoc, diag::ext_extra_semi_cxx11)
221          << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
222    return;
223  }
224
225  if (Kind != AfterMemberFunctionDefinition || HadMultipleSemis)
226    Diag(StartLoc, diag::ext_extra_semi)
227        << Kind << DeclSpec::getSpecifierName((DeclSpec::TST)TST,
228                                    Actions.getASTContext().getPrintingPolicy())
229        << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
230  else
231    // A single semicolon is valid after a member function definition.
232    Diag(StartLoc, diag::warn_extra_semi_after_mem_fn_def)
233      << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
234}
235
236//===----------------------------------------------------------------------===//
237// Error recovery.
238//===----------------------------------------------------------------------===//
239
240static bool HasFlagsSet(Parser::SkipUntilFlags L, Parser::SkipUntilFlags R) {
241  return (static_cast<unsigned>(L) & static_cast<unsigned>(R)) != 0;
242}
243
244/// SkipUntil - Read tokens until we get to the specified token, then consume
245/// it (unless no flag StopBeforeMatch).  Because we cannot guarantee that the
246/// token will ever occur, this skips to the next token, or to some likely
247/// good stopping point.  If StopAtSemi is true, skipping will stop at a ';'
248/// character.
249///
250/// If SkipUntil finds the specified token, it returns true, otherwise it
251/// returns false.
252bool Parser::SkipUntil(ArrayRef<tok::TokenKind> Toks, SkipUntilFlags Flags) {
253  // We always want this function to skip at least one token if the first token
254  // isn't T and if not at EOF.
255  bool isFirstTokenSkipped = true;
256  while (1) {
257    // If we found one of the tokens, stop and return true.
258    for (unsigned i = 0, NumToks = Toks.size(); i != NumToks; ++i) {
259      if (Tok.is(Toks[i])) {
260        if (HasFlagsSet(Flags, StopBeforeMatch)) {
261          // Noop, don't consume the token.
262        } else {
263          ConsumeAnyToken();
264        }
265        return true;
266      }
267    }
268
269    // Important special case: The caller has given up and just wants us to
270    // skip the rest of the file. Do this without recursing, since we can
271    // get here precisely because the caller detected too much recursion.
272    if (Toks.size() == 1 && Toks[0] == tok::eof &&
273        !HasFlagsSet(Flags, StopAtSemi) &&
274        !HasFlagsSet(Flags, StopAtCodeCompletion)) {
275      while (Tok.isNot(tok::eof))
276        ConsumeAnyToken();
277      return true;
278    }
279
280    switch (Tok.getKind()) {
281    case tok::eof:
282      // Ran out of tokens.
283      return false;
284
285    case tok::annot_pragma_openmp:
286    case tok::annot_pragma_openmp_end:
287      // Stop before an OpenMP pragma boundary.
288    case tok::annot_module_begin:
289    case tok::annot_module_end:
290    case tok::annot_module_include:
291      // Stop before we change submodules. They generally indicate a "good"
292      // place to pick up parsing again (except in the special case where
293      // we're trying to skip to EOF).
294      return false;
295
296    case tok::code_completion:
297      if (!HasFlagsSet(Flags, StopAtCodeCompletion))
298        handleUnexpectedCodeCompletionToken();
299      return false;
300
301    case tok::l_paren:
302      // Recursively skip properly-nested parens.
303      ConsumeParen();
304      if (HasFlagsSet(Flags, StopAtCodeCompletion))
305        SkipUntil(tok::r_paren, StopAtCodeCompletion);
306      else
307        SkipUntil(tok::r_paren);
308      break;
309    case tok::l_square:
310      // Recursively skip properly-nested square brackets.
311      ConsumeBracket();
312      if (HasFlagsSet(Flags, StopAtCodeCompletion))
313        SkipUntil(tok::r_square, StopAtCodeCompletion);
314      else
315        SkipUntil(tok::r_square);
316      break;
317    case tok::l_brace:
318      // Recursively skip properly-nested braces.
319      ConsumeBrace();
320      if (HasFlagsSet(Flags, StopAtCodeCompletion))
321        SkipUntil(tok::r_brace, StopAtCodeCompletion);
322      else
323        SkipUntil(tok::r_brace);
324      break;
325
326    // Okay, we found a ']' or '}' or ')', which we think should be balanced.
327    // Since the user wasn't looking for this token (if they were, it would
328    // already be handled), this isn't balanced.  If there is a LHS token at a
329    // higher level, we will assume that this matches the unbalanced token
330    // and return it.  Otherwise, this is a spurious RHS token, which we skip.
331    case tok::r_paren:
332      if (ParenCount && !isFirstTokenSkipped)
333        return false;  // Matches something.
334      ConsumeParen();
335      break;
336    case tok::r_square:
337      if (BracketCount && !isFirstTokenSkipped)
338        return false;  // Matches something.
339      ConsumeBracket();
340      break;
341    case tok::r_brace:
342      if (BraceCount && !isFirstTokenSkipped)
343        return false;  // Matches something.
344      ConsumeBrace();
345      break;
346
347    case tok::string_literal:
348    case tok::wide_string_literal:
349    case tok::utf8_string_literal:
350    case tok::utf16_string_literal:
351    case tok::utf32_string_literal:
352      ConsumeStringToken();
353      break;
354
355    case tok::semi:
356      if (HasFlagsSet(Flags, StopAtSemi))
357        return false;
358      // FALL THROUGH.
359    default:
360      // Skip this token.
361      ConsumeToken();
362      break;
363    }
364    isFirstTokenSkipped = false;
365  }
366}
367
368//===----------------------------------------------------------------------===//
369// Scope manipulation
370//===----------------------------------------------------------------------===//
371
372/// EnterScope - Start a new scope.
373void Parser::EnterScope(unsigned ScopeFlags) {
374  if (NumCachedScopes) {
375    Scope *N = ScopeCache[--NumCachedScopes];
376    N->Init(getCurScope(), ScopeFlags);
377    Actions.CurScope = N;
378  } else {
379    Actions.CurScope = new Scope(getCurScope(), ScopeFlags, Diags);
380  }
381}
382
383/// ExitScope - Pop a scope off the scope stack.
384void Parser::ExitScope() {
385  assert(getCurScope() && "Scope imbalance!");
386
387  // Inform the actions module that this scope is going away if there are any
388  // decls in it.
389  Actions.ActOnPopScope(Tok.getLocation(), getCurScope());
390
391  Scope *OldScope = getCurScope();
392  Actions.CurScope = OldScope->getParent();
393
394  if (NumCachedScopes == ScopeCacheSize)
395    delete OldScope;
396  else
397    ScopeCache[NumCachedScopes++] = OldScope;
398}
399
400/// Set the flags for the current scope to ScopeFlags. If ManageFlags is false,
401/// this object does nothing.
402Parser::ParseScopeFlags::ParseScopeFlags(Parser *Self, unsigned ScopeFlags,
403                                 bool ManageFlags)
404  : CurScope(ManageFlags ? Self->getCurScope() : nullptr) {
405  if (CurScope) {
406    OldFlags = CurScope->getFlags();
407    CurScope->setFlags(ScopeFlags);
408  }
409}
410
411/// Restore the flags for the current scope to what they were before this
412/// object overrode them.
413Parser::ParseScopeFlags::~ParseScopeFlags() {
414  if (CurScope)
415    CurScope->setFlags(OldFlags);
416}
417
418
419//===----------------------------------------------------------------------===//
420// C99 6.9: External Definitions.
421//===----------------------------------------------------------------------===//
422
423Parser::~Parser() {
424  // If we still have scopes active, delete the scope tree.
425  delete getCurScope();
426  Actions.CurScope = nullptr;
427
428  // Free the scope cache.
429  for (unsigned i = 0, e = NumCachedScopes; i != e; ++i)
430    delete ScopeCache[i];
431
432  resetPragmaHandlers();
433
434  PP.removeCommentHandler(CommentSemaHandler.get());
435
436  PP.clearCodeCompletionHandler();
437
438  if (getLangOpts().DelayedTemplateParsing &&
439      !PP.isIncrementalProcessingEnabled() && !TemplateIds.empty()) {
440    // If an ASTConsumer parsed delay-parsed templates in their
441    // HandleTranslationUnit() method, TemplateIds created there were not
442    // guarded by a DestroyTemplateIdAnnotationsRAIIObj object in
443    // ParseTopLevelDecl(). Destroy them here.
444    DestroyTemplateIdAnnotationsRAIIObj CleanupRAII(TemplateIds);
445  }
446
447  assert(TemplateIds.empty() && "Still alive TemplateIdAnnotations around?");
448}
449
450/// Initialize - Warm up the parser.
451///
452void Parser::Initialize() {
453  // Create the translation unit scope.  Install it as the current scope.
454  assert(getCurScope() == nullptr && "A scope is already active?");
455  EnterScope(Scope::DeclScope);
456  Actions.ActOnTranslationUnitScope(getCurScope());
457
458  // Initialization for Objective-C context sensitive keywords recognition.
459  // Referenced in Parser::ParseObjCTypeQualifierList.
460  if (getLangOpts().ObjC1) {
461    ObjCTypeQuals[objc_in] = &PP.getIdentifierTable().get("in");
462    ObjCTypeQuals[objc_out] = &PP.getIdentifierTable().get("out");
463    ObjCTypeQuals[objc_inout] = &PP.getIdentifierTable().get("inout");
464    ObjCTypeQuals[objc_oneway] = &PP.getIdentifierTable().get("oneway");
465    ObjCTypeQuals[objc_bycopy] = &PP.getIdentifierTable().get("bycopy");
466    ObjCTypeQuals[objc_byref] = &PP.getIdentifierTable().get("byref");
467    ObjCTypeQuals[objc_nonnull] = &PP.getIdentifierTable().get("nonnull");
468    ObjCTypeQuals[objc_nullable] = &PP.getIdentifierTable().get("nullable");
469    ObjCTypeQuals[objc_null_unspecified]
470      = &PP.getIdentifierTable().get("null_unspecified");
471  }
472
473  Ident_instancetype = nullptr;
474  Ident_final = nullptr;
475  Ident_sealed = nullptr;
476  Ident_override = nullptr;
477
478  Ident_super = &PP.getIdentifierTable().get("super");
479
480  Ident_vector = nullptr;
481  Ident_bool = nullptr;
482  Ident_pixel = nullptr;
483  if (getLangOpts().AltiVec || getLangOpts().ZVector) {
484    Ident_vector = &PP.getIdentifierTable().get("vector");
485    Ident_bool = &PP.getIdentifierTable().get("bool");
486  }
487  if (getLangOpts().AltiVec)
488    Ident_pixel = &PP.getIdentifierTable().get("pixel");
489
490  Ident_introduced = nullptr;
491  Ident_deprecated = nullptr;
492  Ident_obsoleted = nullptr;
493  Ident_unavailable = nullptr;
494  Ident_strict = nullptr;
495  Ident_replacement = nullptr;
496
497  Ident__except = nullptr;
498
499  Ident__exception_code = Ident__exception_info = nullptr;
500  Ident__abnormal_termination = Ident___exception_code = nullptr;
501  Ident___exception_info = Ident___abnormal_termination = nullptr;
502  Ident_GetExceptionCode = Ident_GetExceptionInfo = nullptr;
503  Ident_AbnormalTermination = nullptr;
504
505  if(getLangOpts().Borland) {
506    Ident__exception_info        = PP.getIdentifierInfo("_exception_info");
507    Ident___exception_info       = PP.getIdentifierInfo("__exception_info");
508    Ident_GetExceptionInfo       = PP.getIdentifierInfo("GetExceptionInformation");
509    Ident__exception_code        = PP.getIdentifierInfo("_exception_code");
510    Ident___exception_code       = PP.getIdentifierInfo("__exception_code");
511    Ident_GetExceptionCode       = PP.getIdentifierInfo("GetExceptionCode");
512    Ident__abnormal_termination  = PP.getIdentifierInfo("_abnormal_termination");
513    Ident___abnormal_termination = PP.getIdentifierInfo("__abnormal_termination");
514    Ident_AbnormalTermination    = PP.getIdentifierInfo("AbnormalTermination");
515
516    PP.SetPoisonReason(Ident__exception_code,diag::err_seh___except_block);
517    PP.SetPoisonReason(Ident___exception_code,diag::err_seh___except_block);
518    PP.SetPoisonReason(Ident_GetExceptionCode,diag::err_seh___except_block);
519    PP.SetPoisonReason(Ident__exception_info,diag::err_seh___except_filter);
520    PP.SetPoisonReason(Ident___exception_info,diag::err_seh___except_filter);
521    PP.SetPoisonReason(Ident_GetExceptionInfo,diag::err_seh___except_filter);
522    PP.SetPoisonReason(Ident__abnormal_termination,diag::err_seh___finally_block);
523    PP.SetPoisonReason(Ident___abnormal_termination,diag::err_seh___finally_block);
524    PP.SetPoisonReason(Ident_AbnormalTermination,diag::err_seh___finally_block);
525  }
526
527  Actions.Initialize();
528
529  // Prime the lexer look-ahead.
530  ConsumeToken();
531}
532
533void Parser::LateTemplateParserCleanupCallback(void *P) {
534  // While this RAII helper doesn't bracket any actual work, the destructor will
535  // clean up annotations that were created during ActOnEndOfTranslationUnit
536  // when incremental processing is enabled.
537  DestroyTemplateIdAnnotationsRAIIObj CleanupRAII(((Parser *)P)->TemplateIds);
538}
539
540/// ParseTopLevelDecl - Parse one top-level declaration, return whatever the
541/// action tells us to.  This returns true if the EOF was encountered.
542bool Parser::ParseTopLevelDecl(DeclGroupPtrTy &Result) {
543  DestroyTemplateIdAnnotationsRAIIObj CleanupRAII(TemplateIds);
544
545  // Skip over the EOF token, flagging end of previous input for incremental
546  // processing
547  if (PP.isIncrementalProcessingEnabled() && Tok.is(tok::eof))
548    ConsumeToken();
549
550  Result = nullptr;
551  switch (Tok.getKind()) {
552  case tok::annot_pragma_unused:
553    HandlePragmaUnused();
554    return false;
555
556  case tok::annot_module_include:
557    Actions.ActOnModuleInclude(Tok.getLocation(),
558                               reinterpret_cast<Module *>(
559                                   Tok.getAnnotationValue()));
560    ConsumeToken();
561    return false;
562
563  case tok::annot_module_begin:
564    Actions.ActOnModuleBegin(Tok.getLocation(), reinterpret_cast<Module *>(
565                                                    Tok.getAnnotationValue()));
566    ConsumeToken();
567    return false;
568
569  case tok::annot_module_end:
570    Actions.ActOnModuleEnd(Tok.getLocation(), reinterpret_cast<Module *>(
571                                                  Tok.getAnnotationValue()));
572    ConsumeToken();
573    return false;
574
575  case tok::eof:
576    // Late template parsing can begin.
577    if (getLangOpts().DelayedTemplateParsing)
578      Actions.SetLateTemplateParser(LateTemplateParserCallback,
579                                    PP.isIncrementalProcessingEnabled() ?
580                                    LateTemplateParserCleanupCallback : nullptr,
581                                    this);
582    if (!PP.isIncrementalProcessingEnabled())
583      Actions.ActOnEndOfTranslationUnit();
584    //else don't tell Sema that we ended parsing: more input might come.
585    return true;
586
587  default:
588    break;
589  }
590
591  ParsedAttributesWithRange attrs(AttrFactory);
592  MaybeParseCXX11Attributes(attrs);
593  MaybeParseMicrosoftAttributes(attrs);
594
595  Result = ParseExternalDeclaration(attrs);
596  return false;
597}
598
599/// ParseExternalDeclaration:
600///
601///       external-declaration: [C99 6.9], declaration: [C++ dcl.dcl]
602///         function-definition
603///         declaration
604/// [GNU]   asm-definition
605/// [GNU]   __extension__ external-declaration
606/// [OBJC]  objc-class-definition
607/// [OBJC]  objc-class-declaration
608/// [OBJC]  objc-alias-declaration
609/// [OBJC]  objc-protocol-definition
610/// [OBJC]  objc-method-definition
611/// [OBJC]  @end
612/// [C++]   linkage-specification
613/// [GNU] asm-definition:
614///         simple-asm-expr ';'
615/// [C++11] empty-declaration
616/// [C++11] attribute-declaration
617///
618/// [C++11] empty-declaration:
619///           ';'
620///
621/// [C++0x/GNU] 'extern' 'template' declaration
622Parser::DeclGroupPtrTy
623Parser::ParseExternalDeclaration(ParsedAttributesWithRange &attrs,
624                                 ParsingDeclSpec *DS) {
625  DestroyTemplateIdAnnotationsRAIIObj CleanupRAII(TemplateIds);
626  ParenBraceBracketBalancer BalancerRAIIObj(*this);
627
628  if (PP.isCodeCompletionReached()) {
629    cutOffParsing();
630    return nullptr;
631  }
632
633  Decl *SingleDecl = nullptr;
634  switch (Tok.getKind()) {
635  case tok::annot_pragma_vis:
636    HandlePragmaVisibility();
637    return nullptr;
638  case tok::annot_pragma_pack:
639    HandlePragmaPack();
640    return nullptr;
641  case tok::annot_pragma_msstruct:
642    HandlePragmaMSStruct();
643    return nullptr;
644  case tok::annot_pragma_align:
645    HandlePragmaAlign();
646    return nullptr;
647  case tok::annot_pragma_weak:
648    HandlePragmaWeak();
649    return nullptr;
650  case tok::annot_pragma_weakalias:
651    HandlePragmaWeakAlias();
652    return nullptr;
653  case tok::annot_pragma_redefine_extname:
654    HandlePragmaRedefineExtname();
655    return nullptr;
656  case tok::annot_pragma_fp_contract:
657    HandlePragmaFPContract();
658    return nullptr;
659  case tok::annot_pragma_opencl_extension:
660    HandlePragmaOpenCLExtension();
661    return nullptr;
662  case tok::annot_pragma_openmp: {
663    AccessSpecifier AS = AS_none;
664    return ParseOpenMPDeclarativeDirectiveWithExtDecl(AS, attrs);
665  }
666  case tok::annot_pragma_ms_pointers_to_members:
667    HandlePragmaMSPointersToMembers();
668    return nullptr;
669  case tok::annot_pragma_ms_vtordisp:
670    HandlePragmaMSVtorDisp();
671    return nullptr;
672  case tok::annot_pragma_ms_pragma:
673    HandlePragmaMSPragma();
674    return nullptr;
675  case tok::annot_pragma_dump:
676    HandlePragmaDump();
677    return nullptr;
678  case tok::semi:
679    // Either a C++11 empty-declaration or attribute-declaration.
680    SingleDecl = Actions.ActOnEmptyDeclaration(getCurScope(),
681                                               attrs.getList(),
682                                               Tok.getLocation());
683    ConsumeExtraSemi(OutsideFunction);
684    break;
685  case tok::r_brace:
686    Diag(Tok, diag::err_extraneous_closing_brace);
687    ConsumeBrace();
688    return nullptr;
689  case tok::eof:
690    Diag(Tok, diag::err_expected_external_declaration);
691    return nullptr;
692  case tok::kw___extension__: {
693    // __extension__ silences extension warnings in the subexpression.
694    ExtensionRAIIObject O(Diags);  // Use RAII to do this.
695    ConsumeToken();
696    return ParseExternalDeclaration(attrs);
697  }
698  case tok::kw_asm: {
699    ProhibitAttributes(attrs);
700
701    SourceLocation StartLoc = Tok.getLocation();
702    SourceLocation EndLoc;
703
704    ExprResult Result(ParseSimpleAsm(&EndLoc));
705
706    // Check if GNU-style InlineAsm is disabled.
707    // Empty asm string is allowed because it will not introduce
708    // any assembly code.
709    if (!(getLangOpts().GNUAsm || Result.isInvalid())) {
710      const auto *SL = cast<StringLiteral>(Result.get());
711      if (!SL->getString().trim().empty())
712        Diag(StartLoc, diag::err_gnu_inline_asm_disabled);
713    }
714
715    ExpectAndConsume(tok::semi, diag::err_expected_after,
716                     "top-level asm block");
717
718    if (Result.isInvalid())
719      return nullptr;
720    SingleDecl = Actions.ActOnFileScopeAsmDecl(Result.get(), StartLoc, EndLoc);
721    break;
722  }
723  case tok::at:
724    return ParseObjCAtDirectives();
725  case tok::minus:
726  case tok::plus:
727    if (!getLangOpts().ObjC1) {
728      Diag(Tok, diag::err_expected_external_declaration);
729      ConsumeToken();
730      return nullptr;
731    }
732    SingleDecl = ParseObjCMethodDefinition();
733    break;
734  case tok::code_completion:
735      Actions.CodeCompleteOrdinaryName(getCurScope(),
736                             CurParsedObjCImpl? Sema::PCC_ObjCImplementation
737                                              : Sema::PCC_Namespace);
738    cutOffParsing();
739    return nullptr;
740  case tok::kw_using:
741  case tok::kw_namespace:
742  case tok::kw_typedef:
743  case tok::kw_template:
744  case tok::kw_export:    // As in 'export template'
745  case tok::kw_static_assert:
746  case tok::kw__Static_assert:
747    // A function definition cannot start with any of these keywords.
748    {
749      SourceLocation DeclEnd;
750      return ParseDeclaration(Declarator::FileContext, DeclEnd, attrs);
751    }
752
753  case tok::kw_static:
754    // Parse (then ignore) 'static' prior to a template instantiation. This is
755    // a GCC extension that we intentionally do not support.
756    if (getLangOpts().CPlusPlus && NextToken().is(tok::kw_template)) {
757      Diag(ConsumeToken(), diag::warn_static_inline_explicit_inst_ignored)
758        << 0;
759      SourceLocation DeclEnd;
760      return ParseDeclaration(Declarator::FileContext, DeclEnd, attrs);
761    }
762    goto dont_know;
763
764  case tok::kw_inline:
765    if (getLangOpts().CPlusPlus) {
766      tok::TokenKind NextKind = NextToken().getKind();
767
768      // Inline namespaces. Allowed as an extension even in C++03.
769      if (NextKind == tok::kw_namespace) {
770        SourceLocation DeclEnd;
771        return ParseDeclaration(Declarator::FileContext, DeclEnd, attrs);
772      }
773
774      // Parse (then ignore) 'inline' prior to a template instantiation. This is
775      // a GCC extension that we intentionally do not support.
776      if (NextKind == tok::kw_template) {
777        Diag(ConsumeToken(), diag::warn_static_inline_explicit_inst_ignored)
778          << 1;
779        SourceLocation DeclEnd;
780        return ParseDeclaration(Declarator::FileContext, DeclEnd, attrs);
781      }
782    }
783    goto dont_know;
784
785  case tok::kw_extern:
786    if (getLangOpts().CPlusPlus && NextToken().is(tok::kw_template)) {
787      // Extern templates
788      SourceLocation ExternLoc = ConsumeToken();
789      SourceLocation TemplateLoc = ConsumeToken();
790      Diag(ExternLoc, getLangOpts().CPlusPlus11 ?
791             diag::warn_cxx98_compat_extern_template :
792             diag::ext_extern_template) << SourceRange(ExternLoc, TemplateLoc);
793      SourceLocation DeclEnd;
794      return Actions.ConvertDeclToDeclGroup(
795                  ParseExplicitInstantiation(Declarator::FileContext,
796                                             ExternLoc, TemplateLoc, DeclEnd));
797    }
798    goto dont_know;
799
800  case tok::kw___if_exists:
801  case tok::kw___if_not_exists:
802    ParseMicrosoftIfExistsExternalDeclaration();
803    return nullptr;
804
805  default:
806  dont_know:
807    // We can't tell whether this is a function-definition or declaration yet.
808    return ParseDeclarationOrFunctionDefinition(attrs, DS);
809  }
810
811  // This routine returns a DeclGroup, if the thing we parsed only contains a
812  // single decl, convert it now.
813  return Actions.ConvertDeclToDeclGroup(SingleDecl);
814}
815
816/// \brief Determine whether the current token, if it occurs after a
817/// declarator, continues a declaration or declaration list.
818bool Parser::isDeclarationAfterDeclarator() {
819  // Check for '= delete' or '= default'
820  if (getLangOpts().CPlusPlus && Tok.is(tok::equal)) {
821    const Token &KW = NextToken();
822    if (KW.is(tok::kw_default) || KW.is(tok::kw_delete))
823      return false;
824  }
825
826  return Tok.is(tok::equal) ||      // int X()=  -> not a function def
827    Tok.is(tok::comma) ||           // int X(),  -> not a function def
828    Tok.is(tok::semi)  ||           // int X();  -> not a function def
829    Tok.is(tok::kw_asm) ||          // int X() __asm__ -> not a function def
830    Tok.is(tok::kw___attribute) ||  // int X() __attr__ -> not a function def
831    (getLangOpts().CPlusPlus &&
832     Tok.is(tok::l_paren));         // int X(0) -> not a function def [C++]
833}
834
835/// \brief Determine whether the current token, if it occurs after a
836/// declarator, indicates the start of a function definition.
837bool Parser::isStartOfFunctionDefinition(const ParsingDeclarator &Declarator) {
838  assert(Declarator.isFunctionDeclarator() && "Isn't a function declarator");
839  if (Tok.is(tok::l_brace))   // int X() {}
840    return true;
841
842  // Handle K&R C argument lists: int X(f) int f; {}
843  if (!getLangOpts().CPlusPlus &&
844      Declarator.getFunctionTypeInfo().isKNRPrototype())
845    return isDeclarationSpecifier();
846
847  if (getLangOpts().CPlusPlus && Tok.is(tok::equal)) {
848    const Token &KW = NextToken();
849    return KW.is(tok::kw_default) || KW.is(tok::kw_delete);
850  }
851
852  return Tok.is(tok::colon) ||         // X() : Base() {} (used for ctors)
853         Tok.is(tok::kw_try);          // X() try { ... }
854}
855
856/// ParseDeclarationOrFunctionDefinition - Parse either a function-definition or
857/// a declaration.  We can't tell which we have until we read up to the
858/// compound-statement in function-definition. TemplateParams, if
859/// non-NULL, provides the template parameters when we're parsing a
860/// C++ template-declaration.
861///
862///       function-definition: [C99 6.9.1]
863///         decl-specs      declarator declaration-list[opt] compound-statement
864/// [C90] function-definition: [C99 6.7.1] - implicit int result
865/// [C90]   decl-specs[opt] declarator declaration-list[opt] compound-statement
866///
867///       declaration: [C99 6.7]
868///         declaration-specifiers init-declarator-list[opt] ';'
869/// [!C99]  init-declarator-list ';'                   [TODO: warn in c99 mode]
870/// [OMP]   threadprivate-directive                              [TODO]
871///
872Parser::DeclGroupPtrTy
873Parser::ParseDeclOrFunctionDefInternal(ParsedAttributesWithRange &attrs,
874                                       ParsingDeclSpec &DS,
875                                       AccessSpecifier AS) {
876  // Parse the common declaration-specifiers piece.
877  ParseDeclarationSpecifiers(DS, ParsedTemplateInfo(), AS, DSC_top_level);
878
879  // If we had a free-standing type definition with a missing semicolon, we
880  // may get this far before the problem becomes obvious.
881  if (DS.hasTagDefinition() &&
882      DiagnoseMissingSemiAfterTagDefinition(DS, AS, DSC_top_level))
883    return nullptr;
884
885  // C99 6.7.2.3p6: Handle "struct-or-union identifier;", "enum { X };"
886  // declaration-specifiers init-declarator-list[opt] ';'
887  if (Tok.is(tok::semi)) {
888    ProhibitAttributes(attrs);
889    ConsumeToken();
890    RecordDecl *AnonRecord = nullptr;
891    Decl *TheDecl = Actions.ParsedFreeStandingDeclSpec(getCurScope(), AS_none,
892                                                       DS, AnonRecord);
893    DS.complete(TheDecl);
894    if (AnonRecord) {
895      Decl* decls[] = {AnonRecord, TheDecl};
896      return Actions.BuildDeclaratorGroup(decls, /*TypeMayContainAuto=*/false);
897    }
898    return Actions.ConvertDeclToDeclGroup(TheDecl);
899  }
900
901  DS.takeAttributesFrom(attrs);
902
903  // ObjC2 allows prefix attributes on class interfaces and protocols.
904  // FIXME: This still needs better diagnostics. We should only accept
905  // attributes here, no types, etc.
906  if (getLangOpts().ObjC2 && Tok.is(tok::at)) {
907    SourceLocation AtLoc = ConsumeToken(); // the "@"
908    if (!Tok.isObjCAtKeyword(tok::objc_interface) &&
909        !Tok.isObjCAtKeyword(tok::objc_protocol)) {
910      Diag(Tok, diag::err_objc_unexpected_attr);
911      SkipUntil(tok::semi); // FIXME: better skip?
912      return nullptr;
913    }
914
915    DS.abort();
916
917    const char *PrevSpec = nullptr;
918    unsigned DiagID;
919    if (DS.SetTypeSpecType(DeclSpec::TST_unspecified, AtLoc, PrevSpec, DiagID,
920                           Actions.getASTContext().getPrintingPolicy()))
921      Diag(AtLoc, DiagID) << PrevSpec;
922
923    if (Tok.isObjCAtKeyword(tok::objc_protocol))
924      return ParseObjCAtProtocolDeclaration(AtLoc, DS.getAttributes());
925
926    return Actions.ConvertDeclToDeclGroup(
927            ParseObjCAtInterfaceDeclaration(AtLoc, DS.getAttributes()));
928  }
929
930  // If the declspec consisted only of 'extern' and we have a string
931  // literal following it, this must be a C++ linkage specifier like
932  // 'extern "C"'.
933  if (getLangOpts().CPlusPlus && isTokenStringLiteral() &&
934      DS.getStorageClassSpec() == DeclSpec::SCS_extern &&
935      DS.getParsedSpecifiers() == DeclSpec::PQ_StorageClassSpecifier) {
936    Decl *TheDecl = ParseLinkage(DS, Declarator::FileContext);
937    return Actions.ConvertDeclToDeclGroup(TheDecl);
938  }
939
940  return ParseDeclGroup(DS, Declarator::FileContext);
941}
942
943Parser::DeclGroupPtrTy
944Parser::ParseDeclarationOrFunctionDefinition(ParsedAttributesWithRange &attrs,
945                                             ParsingDeclSpec *DS,
946                                             AccessSpecifier AS) {
947  if (DS) {
948    return ParseDeclOrFunctionDefInternal(attrs, *DS, AS);
949  } else {
950    ParsingDeclSpec PDS(*this);
951    // Must temporarily exit the objective-c container scope for
952    // parsing c constructs and re-enter objc container scope
953    // afterwards.
954    ObjCDeclContextSwitch ObjCDC(*this);
955
956    return ParseDeclOrFunctionDefInternal(attrs, PDS, AS);
957  }
958}
959
960/// ParseFunctionDefinition - We parsed and verified that the specified
961/// Declarator is well formed.  If this is a K&R-style function, read the
962/// parameters declaration-list, then start the compound-statement.
963///
964///       function-definition: [C99 6.9.1]
965///         decl-specs      declarator declaration-list[opt] compound-statement
966/// [C90] function-definition: [C99 6.7.1] - implicit int result
967/// [C90]   decl-specs[opt] declarator declaration-list[opt] compound-statement
968/// [C++] function-definition: [C++ 8.4]
969///         decl-specifier-seq[opt] declarator ctor-initializer[opt]
970///         function-body
971/// [C++] function-definition: [C++ 8.4]
972///         decl-specifier-seq[opt] declarator function-try-block
973///
974Decl *Parser::ParseFunctionDefinition(ParsingDeclarator &D,
975                                      const ParsedTemplateInfo &TemplateInfo,
976                                      LateParsedAttrList *LateParsedAttrs) {
977  // Poison SEH identifiers so they are flagged as illegal in function bodies.
978  PoisonSEHIdentifiersRAIIObject PoisonSEHIdentifiers(*this, true);
979  const DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
980
981  // If this is C90 and the declspecs were completely missing, fudge in an
982  // implicit int.  We do this here because this is the only place where
983  // declaration-specifiers are completely optional in the grammar.
984  if (getLangOpts().ImplicitInt && D.getDeclSpec().isEmpty()) {
985    const char *PrevSpec;
986    unsigned DiagID;
987    const PrintingPolicy &Policy = Actions.getASTContext().getPrintingPolicy();
988    D.getMutableDeclSpec().SetTypeSpecType(DeclSpec::TST_int,
989                                           D.getIdentifierLoc(),
990                                           PrevSpec, DiagID,
991                                           Policy);
992    D.SetRangeBegin(D.getDeclSpec().getSourceRange().getBegin());
993  }
994
995  // If this declaration was formed with a K&R-style identifier list for the
996  // arguments, parse declarations for all of the args next.
997  // int foo(a,b) int a; float b; {}
998  if (FTI.isKNRPrototype())
999    ParseKNRParamDeclarations(D);
1000
1001  // We should have either an opening brace or, in a C++ constructor,
1002  // we may have a colon.
1003  if (Tok.isNot(tok::l_brace) &&
1004      (!getLangOpts().CPlusPlus ||
1005       (Tok.isNot(tok::colon) && Tok.isNot(tok::kw_try) &&
1006        Tok.isNot(tok::equal)))) {
1007    Diag(Tok, diag::err_expected_fn_body);
1008
1009    // Skip over garbage, until we get to '{'.  Don't eat the '{'.
1010    SkipUntil(tok::l_brace, StopAtSemi | StopBeforeMatch);
1011
1012    // If we didn't find the '{', bail out.
1013    if (Tok.isNot(tok::l_brace))
1014      return nullptr;
1015  }
1016
1017  // Check to make sure that any normal attributes are allowed to be on
1018  // a definition.  Late parsed attributes are checked at the end.
1019  if (Tok.isNot(tok::equal)) {
1020    AttributeList *DtorAttrs = D.getAttributes();
1021    while (DtorAttrs) {
1022      if (DtorAttrs->isKnownToGCC() &&
1023          !DtorAttrs->isCXX11Attribute()) {
1024        Diag(DtorAttrs->getLoc(), diag::warn_attribute_on_function_definition)
1025          << DtorAttrs->getName();
1026      }
1027      DtorAttrs = DtorAttrs->getNext();
1028    }
1029  }
1030
1031  // In delayed template parsing mode, for function template we consume the
1032  // tokens and store them for late parsing at the end of the translation unit.
1033  if (getLangOpts().DelayedTemplateParsing && Tok.isNot(tok::equal) &&
1034      TemplateInfo.Kind == ParsedTemplateInfo::Template &&
1035      Actions.canDelayFunctionBody(D)) {
1036    MultiTemplateParamsArg TemplateParameterLists(*TemplateInfo.TemplateParams);
1037
1038    ParseScope BodyScope(this, Scope::FnScope|Scope::DeclScope);
1039    Scope *ParentScope = getCurScope()->getParent();
1040
1041    D.setFunctionDefinitionKind(FDK_Definition);
1042    Decl *DP = Actions.HandleDeclarator(ParentScope, D,
1043                                        TemplateParameterLists);
1044    D.complete(DP);
1045    D.getMutableDeclSpec().abort();
1046
1047    if (SkipFunctionBodies && (!DP || Actions.canSkipFunctionBody(DP)) &&
1048        trySkippingFunctionBody()) {
1049      BodyScope.Exit();
1050      return Actions.ActOnSkippedFunctionBody(DP);
1051    }
1052
1053    CachedTokens Toks;
1054    LexTemplateFunctionForLateParsing(Toks);
1055
1056    if (DP) {
1057      FunctionDecl *FnD = DP->getAsFunction();
1058      Actions.CheckForFunctionRedefinition(FnD);
1059      Actions.MarkAsLateParsedTemplate(FnD, DP, Toks);
1060    }
1061    return DP;
1062  }
1063  else if (CurParsedObjCImpl &&
1064           !TemplateInfo.TemplateParams &&
1065           (Tok.is(tok::l_brace) || Tok.is(tok::kw_try) ||
1066            Tok.is(tok::colon)) &&
1067      Actions.CurContext->isTranslationUnit()) {
1068    ParseScope BodyScope(this, Scope::FnScope|Scope::DeclScope);
1069    Scope *ParentScope = getCurScope()->getParent();
1070
1071    D.setFunctionDefinitionKind(FDK_Definition);
1072    Decl *FuncDecl = Actions.HandleDeclarator(ParentScope, D,
1073                                              MultiTemplateParamsArg());
1074    D.complete(FuncDecl);
1075    D.getMutableDeclSpec().abort();
1076    if (FuncDecl) {
1077      // Consume the tokens and store them for later parsing.
1078      StashAwayMethodOrFunctionBodyTokens(FuncDecl);
1079      CurParsedObjCImpl->HasCFunction = true;
1080      return FuncDecl;
1081    }
1082    // FIXME: Should we really fall through here?
1083  }
1084
1085  // Enter a scope for the function body.
1086  ParseScope BodyScope(this, Scope::FnScope|Scope::DeclScope);
1087
1088  // Tell the actions module that we have entered a function definition with the
1089  // specified Declarator for the function.
1090  Sema::SkipBodyInfo SkipBody;
1091  Decl *Res = Actions.ActOnStartOfFunctionDef(getCurScope(), D,
1092                                              TemplateInfo.TemplateParams
1093                                                  ? *TemplateInfo.TemplateParams
1094                                                  : MultiTemplateParamsArg(),
1095                                              &SkipBody);
1096
1097  if (SkipBody.ShouldSkip) {
1098    SkipFunctionBody();
1099    return Res;
1100  }
1101
1102  // Break out of the ParsingDeclarator context before we parse the body.
1103  D.complete(Res);
1104
1105  // Break out of the ParsingDeclSpec context, too.  This const_cast is
1106  // safe because we're always the sole owner.
1107  D.getMutableDeclSpec().abort();
1108
1109  if (TryConsumeToken(tok::equal)) {
1110    assert(getLangOpts().CPlusPlus && "Only C++ function definitions have '='");
1111
1112    bool Delete = false;
1113    SourceLocation KWLoc;
1114    if (TryConsumeToken(tok::kw_delete, KWLoc)) {
1115      Diag(KWLoc, getLangOpts().CPlusPlus11
1116                      ? diag::warn_cxx98_compat_defaulted_deleted_function
1117                      : diag::ext_defaulted_deleted_function)
1118        << 1 /* deleted */;
1119      Actions.SetDeclDeleted(Res, KWLoc);
1120      Delete = true;
1121    } else if (TryConsumeToken(tok::kw_default, KWLoc)) {
1122      Diag(KWLoc, getLangOpts().CPlusPlus11
1123                      ? diag::warn_cxx98_compat_defaulted_deleted_function
1124                      : diag::ext_defaulted_deleted_function)
1125        << 0 /* defaulted */;
1126      Actions.SetDeclDefaulted(Res, KWLoc);
1127    } else {
1128      llvm_unreachable("function definition after = not 'delete' or 'default'");
1129    }
1130
1131    if (Tok.is(tok::comma)) {
1132      Diag(KWLoc, diag::err_default_delete_in_multiple_declaration)
1133        << Delete;
1134      SkipUntil(tok::semi);
1135    } else if (ExpectAndConsume(tok::semi, diag::err_expected_after,
1136                                Delete ? "delete" : "default")) {
1137      SkipUntil(tok::semi);
1138    }
1139
1140    Stmt *GeneratedBody = Res ? Res->getBody() : nullptr;
1141    Actions.ActOnFinishFunctionBody(Res, GeneratedBody, false);
1142    return Res;
1143  }
1144
1145  if (SkipFunctionBodies && (!Res || Actions.canSkipFunctionBody(Res)) &&
1146      trySkippingFunctionBody()) {
1147    BodyScope.Exit();
1148    Actions.ActOnSkippedFunctionBody(Res);
1149    return Actions.ActOnFinishFunctionBody(Res, nullptr, false);
1150  }
1151
1152  if (Tok.is(tok::kw_try))
1153    return ParseFunctionTryBlock(Res, BodyScope);
1154
1155  // If we have a colon, then we're probably parsing a C++
1156  // ctor-initializer.
1157  if (Tok.is(tok::colon)) {
1158    ParseConstructorInitializer(Res);
1159
1160    // Recover from error.
1161    if (!Tok.is(tok::l_brace)) {
1162      BodyScope.Exit();
1163      Actions.ActOnFinishFunctionBody(Res, nullptr);
1164      return Res;
1165    }
1166  } else
1167    Actions.ActOnDefaultCtorInitializers(Res);
1168
1169  // Late attributes are parsed in the same scope as the function body.
1170  if (LateParsedAttrs)
1171    ParseLexedAttributeList(*LateParsedAttrs, Res, false, true);
1172
1173  return ParseFunctionStatementBody(Res, BodyScope);
1174}
1175
1176void Parser::SkipFunctionBody() {
1177  if (Tok.is(tok::equal)) {
1178    SkipUntil(tok::semi);
1179    return;
1180  }
1181
1182  bool IsFunctionTryBlock = Tok.is(tok::kw_try);
1183  if (IsFunctionTryBlock)
1184    ConsumeToken();
1185
1186  CachedTokens Skipped;
1187  if (ConsumeAndStoreFunctionPrologue(Skipped))
1188    SkipMalformedDecl();
1189  else {
1190    SkipUntil(tok::r_brace);
1191    while (IsFunctionTryBlock && Tok.is(tok::kw_catch)) {
1192      SkipUntil(tok::l_brace);
1193      SkipUntil(tok::r_brace);
1194    }
1195  }
1196}
1197
1198/// ParseKNRParamDeclarations - Parse 'declaration-list[opt]' which provides
1199/// types for a function with a K&R-style identifier list for arguments.
1200void Parser::ParseKNRParamDeclarations(Declarator &D) {
1201  // We know that the top-level of this declarator is a function.
1202  DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
1203
1204  // Enter function-declaration scope, limiting any declarators to the
1205  // function prototype scope, including parameter declarators.
1206  ParseScope PrototypeScope(this, Scope::FunctionPrototypeScope |
1207                            Scope::FunctionDeclarationScope | Scope::DeclScope);
1208
1209  // Read all the argument declarations.
1210  while (isDeclarationSpecifier()) {
1211    SourceLocation DSStart = Tok.getLocation();
1212
1213    // Parse the common declaration-specifiers piece.
1214    DeclSpec DS(AttrFactory);
1215    ParseDeclarationSpecifiers(DS);
1216
1217    // C99 6.9.1p6: 'each declaration in the declaration list shall have at
1218    // least one declarator'.
1219    // NOTE: GCC just makes this an ext-warn.  It's not clear what it does with
1220    // the declarations though.  It's trivial to ignore them, really hard to do
1221    // anything else with them.
1222    if (TryConsumeToken(tok::semi)) {
1223      Diag(DSStart, diag::err_declaration_does_not_declare_param);
1224      continue;
1225    }
1226
1227    // C99 6.9.1p6: Declarations shall contain no storage-class specifiers other
1228    // than register.
1229    if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
1230        DS.getStorageClassSpec() != DeclSpec::SCS_register) {
1231      Diag(DS.getStorageClassSpecLoc(),
1232           diag::err_invalid_storage_class_in_func_decl);
1233      DS.ClearStorageClassSpecs();
1234    }
1235    if (DS.getThreadStorageClassSpec() != DeclSpec::TSCS_unspecified) {
1236      Diag(DS.getThreadStorageClassSpecLoc(),
1237           diag::err_invalid_storage_class_in_func_decl);
1238      DS.ClearStorageClassSpecs();
1239    }
1240
1241    // Parse the first declarator attached to this declspec.
1242    Declarator ParmDeclarator(DS, Declarator::KNRTypeListContext);
1243    ParseDeclarator(ParmDeclarator);
1244
1245    // Handle the full declarator list.
1246    while (1) {
1247      // If attributes are present, parse them.
1248      MaybeParseGNUAttributes(ParmDeclarator);
1249
1250      // Ask the actions module to compute the type for this declarator.
1251      Decl *Param =
1252        Actions.ActOnParamDeclarator(getCurScope(), ParmDeclarator);
1253
1254      if (Param &&
1255          // A missing identifier has already been diagnosed.
1256          ParmDeclarator.getIdentifier()) {
1257
1258        // Scan the argument list looking for the correct param to apply this
1259        // type.
1260        for (unsigned i = 0; ; ++i) {
1261          // C99 6.9.1p6: those declarators shall declare only identifiers from
1262          // the identifier list.
1263          if (i == FTI.NumParams) {
1264            Diag(ParmDeclarator.getIdentifierLoc(), diag::err_no_matching_param)
1265              << ParmDeclarator.getIdentifier();
1266            break;
1267          }
1268
1269          if (FTI.Params[i].Ident == ParmDeclarator.getIdentifier()) {
1270            // Reject redefinitions of parameters.
1271            if (FTI.Params[i].Param) {
1272              Diag(ParmDeclarator.getIdentifierLoc(),
1273                   diag::err_param_redefinition)
1274                 << ParmDeclarator.getIdentifier();
1275            } else {
1276              FTI.Params[i].Param = Param;
1277            }
1278            break;
1279          }
1280        }
1281      }
1282
1283      // If we don't have a comma, it is either the end of the list (a ';') or
1284      // an error, bail out.
1285      if (Tok.isNot(tok::comma))
1286        break;
1287
1288      ParmDeclarator.clear();
1289
1290      // Consume the comma.
1291      ParmDeclarator.setCommaLoc(ConsumeToken());
1292
1293      // Parse the next declarator.
1294      ParseDeclarator(ParmDeclarator);
1295    }
1296
1297    // Consume ';' and continue parsing.
1298    if (!ExpectAndConsumeSemi(diag::err_expected_semi_declaration))
1299      continue;
1300
1301    // Otherwise recover by skipping to next semi or mandatory function body.
1302    if (SkipUntil(tok::l_brace, StopAtSemi | StopBeforeMatch))
1303      break;
1304    TryConsumeToken(tok::semi);
1305  }
1306
1307  // The actions module must verify that all arguments were declared.
1308  Actions.ActOnFinishKNRParamDeclarations(getCurScope(), D, Tok.getLocation());
1309}
1310
1311
1312/// ParseAsmStringLiteral - This is just a normal string-literal, but is not
1313/// allowed to be a wide string, and is not subject to character translation.
1314///
1315/// [GNU] asm-string-literal:
1316///         string-literal
1317///
1318ExprResult Parser::ParseAsmStringLiteral() {
1319  if (!isTokenStringLiteral()) {
1320    Diag(Tok, diag::err_expected_string_literal)
1321      << /*Source='in...'*/0 << "'asm'";
1322    return ExprError();
1323  }
1324
1325  ExprResult AsmString(ParseStringLiteralExpression());
1326  if (!AsmString.isInvalid()) {
1327    const auto *SL = cast<StringLiteral>(AsmString.get());
1328    if (!SL->isAscii()) {
1329      Diag(Tok, diag::err_asm_operand_wide_string_literal)
1330        << SL->isWide()
1331        << SL->getSourceRange();
1332      return ExprError();
1333    }
1334  }
1335  return AsmString;
1336}
1337
1338/// ParseSimpleAsm
1339///
1340/// [GNU] simple-asm-expr:
1341///         'asm' '(' asm-string-literal ')'
1342///
1343ExprResult Parser::ParseSimpleAsm(SourceLocation *EndLoc) {
1344  assert(Tok.is(tok::kw_asm) && "Not an asm!");
1345  SourceLocation Loc = ConsumeToken();
1346
1347  if (Tok.is(tok::kw_volatile)) {
1348    // Remove from the end of 'asm' to the end of 'volatile'.
1349    SourceRange RemovalRange(PP.getLocForEndOfToken(Loc),
1350                             PP.getLocForEndOfToken(Tok.getLocation()));
1351
1352    Diag(Tok, diag::warn_file_asm_volatile)
1353      << FixItHint::CreateRemoval(RemovalRange);
1354    ConsumeToken();
1355  }
1356
1357  BalancedDelimiterTracker T(*this, tok::l_paren);
1358  if (T.consumeOpen()) {
1359    Diag(Tok, diag::err_expected_lparen_after) << "asm";
1360    return ExprError();
1361  }
1362
1363  ExprResult Result(ParseAsmStringLiteral());
1364
1365  if (!Result.isInvalid()) {
1366    // Close the paren and get the location of the end bracket
1367    T.consumeClose();
1368    if (EndLoc)
1369      *EndLoc = T.getCloseLocation();
1370  } else if (SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch)) {
1371    if (EndLoc)
1372      *EndLoc = Tok.getLocation();
1373    ConsumeParen();
1374  }
1375
1376  return Result;
1377}
1378
1379/// \brief Get the TemplateIdAnnotation from the token and put it in the
1380/// cleanup pool so that it gets destroyed when parsing the current top level
1381/// declaration is finished.
1382TemplateIdAnnotation *Parser::takeTemplateIdAnnotation(const Token &tok) {
1383  assert(tok.is(tok::annot_template_id) && "Expected template-id token");
1384  TemplateIdAnnotation *
1385      Id = static_cast<TemplateIdAnnotation *>(tok.getAnnotationValue());
1386  return Id;
1387}
1388
1389void Parser::AnnotateScopeToken(CXXScopeSpec &SS, bool IsNewAnnotation) {
1390  // Push the current token back into the token stream (or revert it if it is
1391  // cached) and use an annotation scope token for current token.
1392  if (PP.isBacktrackEnabled())
1393    PP.RevertCachedTokens(1);
1394  else
1395    PP.EnterToken(Tok);
1396  Tok.setKind(tok::annot_cxxscope);
1397  Tok.setAnnotationValue(Actions.SaveNestedNameSpecifierAnnotation(SS));
1398  Tok.setAnnotationRange(SS.getRange());
1399
1400  // In case the tokens were cached, have Preprocessor replace them
1401  // with the annotation token.  We don't need to do this if we've
1402  // just reverted back to a prior state.
1403  if (IsNewAnnotation)
1404    PP.AnnotateCachedTokens(Tok);
1405}
1406
1407/// \brief Attempt to classify the name at the current token position. This may
1408/// form a type, scope or primary expression annotation, or replace the token
1409/// with a typo-corrected keyword. This is only appropriate when the current
1410/// name must refer to an entity which has already been declared.
1411///
1412/// \param IsAddressOfOperand Must be \c true if the name is preceded by an '&'
1413///        and might possibly have a dependent nested name specifier.
1414/// \param CCC Indicates how to perform typo-correction for this name. If NULL,
1415///        no typo correction will be performed.
1416Parser::AnnotatedNameKind
1417Parser::TryAnnotateName(bool IsAddressOfOperand,
1418                        std::unique_ptr<CorrectionCandidateCallback> CCC) {
1419  assert(Tok.is(tok::identifier) || Tok.is(tok::annot_cxxscope));
1420
1421  const bool EnteringContext = false;
1422  const bool WasScopeAnnotation = Tok.is(tok::annot_cxxscope);
1423
1424  CXXScopeSpec SS;
1425  if (getLangOpts().CPlusPlus &&
1426      ParseOptionalCXXScopeSpecifier(SS, nullptr, EnteringContext))
1427    return ANK_Error;
1428
1429  if (Tok.isNot(tok::identifier) || SS.isInvalid()) {
1430    if (TryAnnotateTypeOrScopeTokenAfterScopeSpec(EnteringContext, false, SS,
1431                                                  !WasScopeAnnotation))
1432      return ANK_Error;
1433    return ANK_Unresolved;
1434  }
1435
1436  IdentifierInfo *Name = Tok.getIdentifierInfo();
1437  SourceLocation NameLoc = Tok.getLocation();
1438
1439  // FIXME: Move the tentative declaration logic into ClassifyName so we can
1440  // typo-correct to tentatively-declared identifiers.
1441  if (isTentativelyDeclared(Name)) {
1442    // Identifier has been tentatively declared, and thus cannot be resolved as
1443    // an expression. Fall back to annotating it as a type.
1444    if (TryAnnotateTypeOrScopeTokenAfterScopeSpec(EnteringContext, false, SS,
1445                                                  !WasScopeAnnotation))
1446      return ANK_Error;
1447    return Tok.is(tok::annot_typename) ? ANK_Success : ANK_TentativeDecl;
1448  }
1449
1450  Token Next = NextToken();
1451
1452  // Look up and classify the identifier. We don't perform any typo-correction
1453  // after a scope specifier, because in general we can't recover from typos
1454  // there (eg, after correcting 'A::tempalte B<X>::C' [sic], we would need to
1455  // jump back into scope specifier parsing).
1456  Sema::NameClassification Classification = Actions.ClassifyName(
1457      getCurScope(), SS, Name, NameLoc, Next, IsAddressOfOperand,
1458      SS.isEmpty() ? std::move(CCC) : nullptr);
1459
1460  switch (Classification.getKind()) {
1461  case Sema::NC_Error:
1462    return ANK_Error;
1463
1464  case Sema::NC_Keyword:
1465    // The identifier was typo-corrected to a keyword.
1466    Tok.setIdentifierInfo(Name);
1467    Tok.setKind(Name->getTokenID());
1468    PP.TypoCorrectToken(Tok);
1469    if (SS.isNotEmpty())
1470      AnnotateScopeToken(SS, !WasScopeAnnotation);
1471    // We've "annotated" this as a keyword.
1472    return ANK_Success;
1473
1474  case Sema::NC_Unknown:
1475    // It's not something we know about. Leave it unannotated.
1476    break;
1477
1478  case Sema::NC_Type: {
1479    SourceLocation BeginLoc = NameLoc;
1480    if (SS.isNotEmpty())
1481      BeginLoc = SS.getBeginLoc();
1482
1483    /// An Objective-C object type followed by '<' is a specialization of
1484    /// a parameterized class type or a protocol-qualified type.
1485    ParsedType Ty = Classification.getType();
1486    if (getLangOpts().ObjC1 && NextToken().is(tok::less) &&
1487        (Ty.get()->isObjCObjectType() ||
1488         Ty.get()->isObjCObjectPointerType())) {
1489      // Consume the name.
1490      SourceLocation IdentifierLoc = ConsumeToken();
1491      SourceLocation NewEndLoc;
1492      TypeResult NewType
1493          = parseObjCTypeArgsAndProtocolQualifiers(IdentifierLoc, Ty,
1494                                                   /*consumeLastToken=*/false,
1495                                                   NewEndLoc);
1496      if (NewType.isUsable())
1497        Ty = NewType.get();
1498    }
1499
1500    Tok.setKind(tok::annot_typename);
1501    setTypeAnnotation(Tok, Ty);
1502    Tok.setAnnotationEndLoc(Tok.getLocation());
1503    Tok.setLocation(BeginLoc);
1504    PP.AnnotateCachedTokens(Tok);
1505    return ANK_Success;
1506  }
1507
1508  case Sema::NC_Expression:
1509    Tok.setKind(tok::annot_primary_expr);
1510    setExprAnnotation(Tok, Classification.getExpression());
1511    Tok.setAnnotationEndLoc(NameLoc);
1512    if (SS.isNotEmpty())
1513      Tok.setLocation(SS.getBeginLoc());
1514    PP.AnnotateCachedTokens(Tok);
1515    return ANK_Success;
1516
1517  case Sema::NC_TypeTemplate:
1518    if (Next.isNot(tok::less)) {
1519      // This may be a type template being used as a template template argument.
1520      if (SS.isNotEmpty())
1521        AnnotateScopeToken(SS, !WasScopeAnnotation);
1522      return ANK_TemplateName;
1523    }
1524    // Fall through.
1525  case Sema::NC_VarTemplate:
1526  case Sema::NC_FunctionTemplate: {
1527    // We have a type, variable or function template followed by '<'.
1528    ConsumeToken();
1529    UnqualifiedId Id;
1530    Id.setIdentifier(Name, NameLoc);
1531    if (AnnotateTemplateIdToken(
1532            TemplateTy::make(Classification.getTemplateName()),
1533            Classification.getTemplateNameKind(), SS, SourceLocation(), Id))
1534      return ANK_Error;
1535    return ANK_Success;
1536  }
1537
1538  case Sema::NC_NestedNameSpecifier:
1539    llvm_unreachable("already parsed nested name specifier");
1540  }
1541
1542  // Unable to classify the name, but maybe we can annotate a scope specifier.
1543  if (SS.isNotEmpty())
1544    AnnotateScopeToken(SS, !WasScopeAnnotation);
1545  return ANK_Unresolved;
1546}
1547
1548bool Parser::TryKeywordIdentFallback(bool DisableKeyword) {
1549  assert(Tok.isNot(tok::identifier));
1550  Diag(Tok, diag::ext_keyword_as_ident)
1551    << PP.getSpelling(Tok)
1552    << DisableKeyword;
1553  if (DisableKeyword)
1554    Tok.getIdentifierInfo()->revertTokenIDToIdentifier();
1555  Tok.setKind(tok::identifier);
1556  return true;
1557}
1558
1559/// TryAnnotateTypeOrScopeToken - If the current token position is on a
1560/// typename (possibly qualified in C++) or a C++ scope specifier not followed
1561/// by a typename, TryAnnotateTypeOrScopeToken will replace one or more tokens
1562/// with a single annotation token representing the typename or C++ scope
1563/// respectively.
1564/// This simplifies handling of C++ scope specifiers and allows efficient
1565/// backtracking without the need to re-parse and resolve nested-names and
1566/// typenames.
1567/// It will mainly be called when we expect to treat identifiers as typenames
1568/// (if they are typenames). For example, in C we do not expect identifiers
1569/// inside expressions to be treated as typenames so it will not be called
1570/// for expressions in C.
1571/// The benefit for C/ObjC is that a typename will be annotated and
1572/// Actions.getTypeName will not be needed to be called again (e.g. getTypeName
1573/// will not be called twice, once to check whether we have a declaration
1574/// specifier, and another one to get the actual type inside
1575/// ParseDeclarationSpecifiers).
1576///
1577/// This returns true if an error occurred.
1578///
1579/// Note that this routine emits an error if you call it with ::new or ::delete
1580/// as the current tokens, so only call it in contexts where these are invalid.
1581bool Parser::TryAnnotateTypeOrScopeToken(bool EnteringContext, bool NeedType) {
1582  assert((Tok.is(tok::identifier) || Tok.is(tok::coloncolon) ||
1583          Tok.is(tok::kw_typename) || Tok.is(tok::annot_cxxscope) ||
1584          Tok.is(tok::kw_decltype) || Tok.is(tok::annot_template_id) ||
1585          Tok.is(tok::kw___super)) &&
1586         "Cannot be a type or scope token!");
1587
1588  if (Tok.is(tok::kw_typename)) {
1589    // MSVC lets you do stuff like:
1590    //   typename typedef T_::D D;
1591    //
1592    // We will consume the typedef token here and put it back after we have
1593    // parsed the first identifier, transforming it into something more like:
1594    //   typename T_::D typedef D;
1595    if (getLangOpts().MSVCCompat && NextToken().is(tok::kw_typedef)) {
1596      Token TypedefToken;
1597      PP.Lex(TypedefToken);
1598      bool Result = TryAnnotateTypeOrScopeToken(EnteringContext, NeedType);
1599      PP.EnterToken(Tok);
1600      Tok = TypedefToken;
1601      if (!Result)
1602        Diag(Tok.getLocation(), diag::warn_expected_qualified_after_typename);
1603      return Result;
1604    }
1605
1606    // Parse a C++ typename-specifier, e.g., "typename T::type".
1607    //
1608    //   typename-specifier:
1609    //     'typename' '::' [opt] nested-name-specifier identifier
1610    //     'typename' '::' [opt] nested-name-specifier template [opt]
1611    //            simple-template-id
1612    SourceLocation TypenameLoc = ConsumeToken();
1613    CXXScopeSpec SS;
1614    if (ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/nullptr,
1615                                       /*EnteringContext=*/false, nullptr,
1616                                       /*IsTypename*/ true))
1617      return true;
1618    if (!SS.isSet()) {
1619      if (Tok.is(tok::identifier) || Tok.is(tok::annot_template_id) ||
1620          Tok.is(tok::annot_decltype)) {
1621        // Attempt to recover by skipping the invalid 'typename'
1622        if (Tok.is(tok::annot_decltype) ||
1623            (!TryAnnotateTypeOrScopeToken(EnteringContext, NeedType) &&
1624             Tok.isAnnotation())) {
1625          unsigned DiagID = diag::err_expected_qualified_after_typename;
1626          // MS compatibility: MSVC permits using known types with typename.
1627          // e.g. "typedef typename T* pointer_type"
1628          if (getLangOpts().MicrosoftExt)
1629            DiagID = diag::warn_expected_qualified_after_typename;
1630          Diag(Tok.getLocation(), DiagID);
1631          return false;
1632        }
1633      }
1634
1635      Diag(Tok.getLocation(), diag::err_expected_qualified_after_typename);
1636      return true;
1637    }
1638
1639    TypeResult Ty;
1640    if (Tok.is(tok::identifier)) {
1641      // FIXME: check whether the next token is '<', first!
1642      Ty = Actions.ActOnTypenameType(getCurScope(), TypenameLoc, SS,
1643                                     *Tok.getIdentifierInfo(),
1644                                     Tok.getLocation());
1645    } else if (Tok.is(tok::annot_template_id)) {
1646      TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
1647      if (TemplateId->Kind != TNK_Type_template &&
1648          TemplateId->Kind != TNK_Dependent_template_name) {
1649        Diag(Tok, diag::err_typename_refers_to_non_type_template)
1650          << Tok.getAnnotationRange();
1651        return true;
1652      }
1653
1654      ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
1655                                         TemplateId->NumArgs);
1656
1657      Ty = Actions.ActOnTypenameType(getCurScope(), TypenameLoc, SS,
1658                                     TemplateId->TemplateKWLoc,
1659                                     TemplateId->Template,
1660                                     TemplateId->TemplateNameLoc,
1661                                     TemplateId->LAngleLoc,
1662                                     TemplateArgsPtr,
1663                                     TemplateId->RAngleLoc);
1664    } else {
1665      Diag(Tok, diag::err_expected_type_name_after_typename)
1666        << SS.getRange();
1667      return true;
1668    }
1669
1670    SourceLocation EndLoc = Tok.getLastLoc();
1671    Tok.setKind(tok::annot_typename);
1672    setTypeAnnotation(Tok, Ty.isInvalid() ? nullptr : Ty.get());
1673    Tok.setAnnotationEndLoc(EndLoc);
1674    Tok.setLocation(TypenameLoc);
1675    PP.AnnotateCachedTokens(Tok);
1676    return false;
1677  }
1678
1679  // Remembers whether the token was originally a scope annotation.
1680  bool WasScopeAnnotation = Tok.is(tok::annot_cxxscope);
1681
1682  CXXScopeSpec SS;
1683  if (getLangOpts().CPlusPlus)
1684    if (ParseOptionalCXXScopeSpecifier(SS, nullptr, EnteringContext))
1685      return true;
1686
1687  return TryAnnotateTypeOrScopeTokenAfterScopeSpec(EnteringContext, NeedType,
1688                                                   SS, !WasScopeAnnotation);
1689}
1690
1691/// \brief Try to annotate a type or scope token, having already parsed an
1692/// optional scope specifier. \p IsNewScope should be \c true unless the scope
1693/// specifier was extracted from an existing tok::annot_cxxscope annotation.
1694bool Parser::TryAnnotateTypeOrScopeTokenAfterScopeSpec(bool EnteringContext,
1695                                                       bool NeedType,
1696                                                       CXXScopeSpec &SS,
1697                                                       bool IsNewScope) {
1698  if (Tok.is(tok::identifier)) {
1699    IdentifierInfo *CorrectedII = nullptr;
1700    // Determine whether the identifier is a type name.
1701    if (ParsedType Ty = Actions.getTypeName(
1702            *Tok.getIdentifierInfo(), Tok.getLocation(), getCurScope(), &SS,
1703            false, NextToken().is(tok::period), nullptr,
1704            /*IsCtorOrDtorName=*/false,
1705            /*NonTrivialTypeSourceInfo*/ true,
1706            NeedType ? &CorrectedII : nullptr)) {
1707      // A FixIt was applied as a result of typo correction
1708      if (CorrectedII)
1709        Tok.setIdentifierInfo(CorrectedII);
1710
1711      SourceLocation BeginLoc = Tok.getLocation();
1712      if (SS.isNotEmpty()) // it was a C++ qualified type name.
1713        BeginLoc = SS.getBeginLoc();
1714
1715      /// An Objective-C object type followed by '<' is a specialization of
1716      /// a parameterized class type or a protocol-qualified type.
1717      if (getLangOpts().ObjC1 && NextToken().is(tok::less) &&
1718          (Ty.get()->isObjCObjectType() ||
1719           Ty.get()->isObjCObjectPointerType())) {
1720        // Consume the name.
1721        SourceLocation IdentifierLoc = ConsumeToken();
1722        SourceLocation NewEndLoc;
1723        TypeResult NewType
1724          = parseObjCTypeArgsAndProtocolQualifiers(IdentifierLoc, Ty,
1725                                                   /*consumeLastToken=*/false,
1726                                                   NewEndLoc);
1727        if (NewType.isUsable())
1728          Ty = NewType.get();
1729      }
1730
1731      // This is a typename. Replace the current token in-place with an
1732      // annotation type token.
1733      Tok.setKind(tok::annot_typename);
1734      setTypeAnnotation(Tok, Ty);
1735      Tok.setAnnotationEndLoc(Tok.getLocation());
1736      Tok.setLocation(BeginLoc);
1737
1738      // In case the tokens were cached, have Preprocessor replace
1739      // them with the annotation token.
1740      PP.AnnotateCachedTokens(Tok);
1741      return false;
1742    }
1743
1744    if (!getLangOpts().CPlusPlus) {
1745      // If we're in C, we can't have :: tokens at all (the lexer won't return
1746      // them).  If the identifier is not a type, then it can't be scope either,
1747      // just early exit.
1748      return false;
1749    }
1750
1751    // If this is a template-id, annotate with a template-id or type token.
1752    if (NextToken().is(tok::less)) {
1753      TemplateTy Template;
1754      UnqualifiedId TemplateName;
1755      TemplateName.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
1756      bool MemberOfUnknownSpecialization;
1757      if (TemplateNameKind TNK =
1758              Actions.isTemplateName(getCurScope(), SS,
1759                                     /*hasTemplateKeyword=*/false, TemplateName,
1760                                     /*ObjectType=*/nullptr, EnteringContext,
1761                                     Template, MemberOfUnknownSpecialization)) {
1762        // Consume the identifier.
1763        ConsumeToken();
1764        if (AnnotateTemplateIdToken(Template, TNK, SS, SourceLocation(),
1765                                    TemplateName)) {
1766          // If an unrecoverable error occurred, we need to return true here,
1767          // because the token stream is in a damaged state.  We may not return
1768          // a valid identifier.
1769          return true;
1770        }
1771      }
1772    }
1773
1774    // The current token, which is either an identifier or a
1775    // template-id, is not part of the annotation. Fall through to
1776    // push that token back into the stream and complete the C++ scope
1777    // specifier annotation.
1778  }
1779
1780  if (Tok.is(tok::annot_template_id)) {
1781    TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
1782    if (TemplateId->Kind == TNK_Type_template) {
1783      // A template-id that refers to a type was parsed into a
1784      // template-id annotation in a context where we weren't allowed
1785      // to produce a type annotation token. Update the template-id
1786      // annotation token to a type annotation token now.
1787      AnnotateTemplateIdTokenAsType();
1788      return false;
1789    }
1790  }
1791
1792  if (SS.isEmpty())
1793    return false;
1794
1795  // A C++ scope specifier that isn't followed by a typename.
1796  AnnotateScopeToken(SS, IsNewScope);
1797  return false;
1798}
1799
1800/// TryAnnotateScopeToken - Like TryAnnotateTypeOrScopeToken but only
1801/// annotates C++ scope specifiers and template-ids.  This returns
1802/// true if there was an error that could not be recovered from.
1803///
1804/// Note that this routine emits an error if you call it with ::new or ::delete
1805/// as the current tokens, so only call it in contexts where these are invalid.
1806bool Parser::TryAnnotateCXXScopeToken(bool EnteringContext) {
1807  assert(getLangOpts().CPlusPlus &&
1808         "Call sites of this function should be guarded by checking for C++");
1809  assert((Tok.is(tok::identifier) || Tok.is(tok::coloncolon) ||
1810          (Tok.is(tok::annot_template_id) && NextToken().is(tok::coloncolon)) ||
1811          Tok.is(tok::kw_decltype) || Tok.is(tok::kw___super)) &&
1812         "Cannot be a type or scope token!");
1813
1814  CXXScopeSpec SS;
1815  if (ParseOptionalCXXScopeSpecifier(SS, nullptr, EnteringContext))
1816    return true;
1817  if (SS.isEmpty())
1818    return false;
1819
1820  AnnotateScopeToken(SS, true);
1821  return false;
1822}
1823
1824bool Parser::isTokenEqualOrEqualTypo() {
1825  tok::TokenKind Kind = Tok.getKind();
1826  switch (Kind) {
1827  default:
1828    return false;
1829  case tok::ampequal:            // &=
1830  case tok::starequal:           // *=
1831  case tok::plusequal:           // +=
1832  case tok::minusequal:          // -=
1833  case tok::exclaimequal:        // !=
1834  case tok::slashequal:          // /=
1835  case tok::percentequal:        // %=
1836  case tok::lessequal:           // <=
1837  case tok::lesslessequal:       // <<=
1838  case tok::greaterequal:        // >=
1839  case tok::greatergreaterequal: // >>=
1840  case tok::caretequal:          // ^=
1841  case tok::pipeequal:           // |=
1842  case tok::equalequal:          // ==
1843    Diag(Tok, diag::err_invalid_token_after_declarator_suggest_equal)
1844        << Kind
1845        << FixItHint::CreateReplacement(SourceRange(Tok.getLocation()), "=");
1846  case tok::equal:
1847    return true;
1848  }
1849}
1850
1851SourceLocation Parser::handleUnexpectedCodeCompletionToken() {
1852  assert(Tok.is(tok::code_completion));
1853  PrevTokLocation = Tok.getLocation();
1854
1855  for (Scope *S = getCurScope(); S; S = S->getParent()) {
1856    if (S->getFlags() & Scope::FnScope) {
1857      Actions.CodeCompleteOrdinaryName(getCurScope(),
1858                                       Sema::PCC_RecoveryInFunction);
1859      cutOffParsing();
1860      return PrevTokLocation;
1861    }
1862
1863    if (S->getFlags() & Scope::ClassScope) {
1864      Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Class);
1865      cutOffParsing();
1866      return PrevTokLocation;
1867    }
1868  }
1869
1870  Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Namespace);
1871  cutOffParsing();
1872  return PrevTokLocation;
1873}
1874
1875// Code-completion pass-through functions
1876
1877void Parser::CodeCompleteDirective(bool InConditional) {
1878  Actions.CodeCompletePreprocessorDirective(InConditional);
1879}
1880
1881void Parser::CodeCompleteInConditionalExclusion() {
1882  Actions.CodeCompleteInPreprocessorConditionalExclusion(getCurScope());
1883}
1884
1885void Parser::CodeCompleteMacroName(bool IsDefinition) {
1886  Actions.CodeCompletePreprocessorMacroName(IsDefinition);
1887}
1888
1889void Parser::CodeCompletePreprocessorExpression() {
1890  Actions.CodeCompletePreprocessorExpression();
1891}
1892
1893void Parser::CodeCompleteMacroArgument(IdentifierInfo *Macro,
1894                                       MacroInfo *MacroInfo,
1895                                       unsigned ArgumentIndex) {
1896  Actions.CodeCompletePreprocessorMacroArgument(getCurScope(), Macro, MacroInfo,
1897                                                ArgumentIndex);
1898}
1899
1900void Parser::CodeCompleteNaturalLanguage() {
1901  Actions.CodeCompleteNaturalLanguage();
1902}
1903
1904bool Parser::ParseMicrosoftIfExistsCondition(IfExistsCondition& Result) {
1905  assert((Tok.is(tok::kw___if_exists) || Tok.is(tok::kw___if_not_exists)) &&
1906         "Expected '__if_exists' or '__if_not_exists'");
1907  Result.IsIfExists = Tok.is(tok::kw___if_exists);
1908  Result.KeywordLoc = ConsumeToken();
1909
1910  BalancedDelimiterTracker T(*this, tok::l_paren);
1911  if (T.consumeOpen()) {
1912    Diag(Tok, diag::err_expected_lparen_after)
1913      << (Result.IsIfExists? "__if_exists" : "__if_not_exists");
1914    return true;
1915  }
1916
1917  // Parse nested-name-specifier.
1918  if (getLangOpts().CPlusPlus)
1919    ParseOptionalCXXScopeSpecifier(Result.SS, nullptr,
1920                                   /*EnteringContext=*/false);
1921
1922  // Check nested-name specifier.
1923  if (Result.SS.isInvalid()) {
1924    T.skipToEnd();
1925    return true;
1926  }
1927
1928  // Parse the unqualified-id.
1929  SourceLocation TemplateKWLoc; // FIXME: parsed, but unused.
1930  if (ParseUnqualifiedId(Result.SS, false, true, true, nullptr, TemplateKWLoc,
1931                         Result.Name)) {
1932    T.skipToEnd();
1933    return true;
1934  }
1935
1936  if (T.consumeClose())
1937    return true;
1938
1939  // Check if the symbol exists.
1940  switch (Actions.CheckMicrosoftIfExistsSymbol(getCurScope(), Result.KeywordLoc,
1941                                               Result.IsIfExists, Result.SS,
1942                                               Result.Name)) {
1943  case Sema::IER_Exists:
1944    Result.Behavior = Result.IsIfExists ? IEB_Parse : IEB_Skip;
1945    break;
1946
1947  case Sema::IER_DoesNotExist:
1948    Result.Behavior = !Result.IsIfExists ? IEB_Parse : IEB_Skip;
1949    break;
1950
1951  case Sema::IER_Dependent:
1952    Result.Behavior = IEB_Dependent;
1953    break;
1954
1955  case Sema::IER_Error:
1956    return true;
1957  }
1958
1959  return false;
1960}
1961
1962void Parser::ParseMicrosoftIfExistsExternalDeclaration() {
1963  IfExistsCondition Result;
1964  if (ParseMicrosoftIfExistsCondition(Result))
1965    return;
1966
1967  BalancedDelimiterTracker Braces(*this, tok::l_brace);
1968  if (Braces.consumeOpen()) {
1969    Diag(Tok, diag::err_expected) << tok::l_brace;
1970    return;
1971  }
1972
1973  switch (Result.Behavior) {
1974  case IEB_Parse:
1975    // Parse declarations below.
1976    break;
1977
1978  case IEB_Dependent:
1979    llvm_unreachable("Cannot have a dependent external declaration");
1980
1981  case IEB_Skip:
1982    Braces.skipToEnd();
1983    return;
1984  }
1985
1986  // Parse the declarations.
1987  // FIXME: Support module import within __if_exists?
1988  while (Tok.isNot(tok::r_brace) && !isEofOrEom()) {
1989    ParsedAttributesWithRange attrs(AttrFactory);
1990    MaybeParseCXX11Attributes(attrs);
1991    MaybeParseMicrosoftAttributes(attrs);
1992    DeclGroupPtrTy Result = ParseExternalDeclaration(attrs);
1993    if (Result && !getCurScope()->getParent())
1994      Actions.getASTConsumer().HandleTopLevelDecl(Result.get());
1995  }
1996  Braces.consumeClose();
1997}
1998
1999Parser::DeclGroupPtrTy Parser::ParseModuleImport(SourceLocation AtLoc) {
2000  assert(Tok.isObjCAtKeyword(tok::objc_import) &&
2001         "Improper start to module import");
2002  SourceLocation ImportLoc = ConsumeToken();
2003
2004  SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> Path;
2005
2006  // Parse the module path.
2007  do {
2008    if (!Tok.is(tok::identifier)) {
2009      if (Tok.is(tok::code_completion)) {
2010        Actions.CodeCompleteModuleImport(ImportLoc, Path);
2011        cutOffParsing();
2012        return nullptr;
2013      }
2014
2015      Diag(Tok, diag::err_module_expected_ident);
2016      SkipUntil(tok::semi);
2017      return nullptr;
2018    }
2019
2020    // Record this part of the module path.
2021    Path.push_back(std::make_pair(Tok.getIdentifierInfo(), Tok.getLocation()));
2022    ConsumeToken();
2023
2024    if (Tok.is(tok::period)) {
2025      ConsumeToken();
2026      continue;
2027    }
2028
2029    break;
2030  } while (true);
2031
2032  if (PP.hadModuleLoaderFatalFailure()) {
2033    // With a fatal failure in the module loader, we abort parsing.
2034    cutOffParsing();
2035    return nullptr;
2036  }
2037
2038  DeclResult Import = Actions.ActOnModuleImport(AtLoc, ImportLoc, Path);
2039  ExpectAndConsumeSemi(diag::err_module_expected_semi);
2040  if (Import.isInvalid())
2041    return nullptr;
2042
2043  return Actions.ConvertDeclToDeclGroup(Import.get());
2044}
2045
2046/// \brief Try recover parser when module annotation appears where it must not
2047/// be found.
2048/// \returns false if the recover was successful and parsing may be continued, or
2049/// true if parser must bail out to top level and handle the token there.
2050bool Parser::parseMisplacedModuleImport() {
2051  while (true) {
2052    switch (Tok.getKind()) {
2053    case tok::annot_module_end:
2054      // Inform caller that recovery failed, the error must be handled at upper
2055      // level.
2056      return true;
2057    case tok::annot_module_begin:
2058      Actions.diagnoseMisplacedModuleImport(reinterpret_cast<Module *>(
2059        Tok.getAnnotationValue()), Tok.getLocation());
2060      return true;
2061    case tok::annot_module_include:
2062      // Module import found where it should not be, for instance, inside a
2063      // namespace. Recover by importing the module.
2064      Actions.ActOnModuleInclude(Tok.getLocation(),
2065                                 reinterpret_cast<Module *>(
2066                                 Tok.getAnnotationValue()));
2067      ConsumeToken();
2068      // If there is another module import, process it.
2069      continue;
2070    default:
2071      return false;
2072    }
2073  }
2074  return false;
2075}
2076
2077bool BalancedDelimiterTracker::diagnoseOverflow() {
2078  P.Diag(P.Tok, diag::err_bracket_depth_exceeded)
2079    << P.getLangOpts().BracketDepth;
2080  P.Diag(P.Tok, diag::note_bracket_depth);
2081  P.cutOffParsing();
2082  return true;
2083}
2084
2085bool BalancedDelimiterTracker::expectAndConsume(unsigned DiagID,
2086                                                const char *Msg,
2087                                                tok::TokenKind SkipToTok) {
2088  LOpen = P.Tok.getLocation();
2089  if (P.ExpectAndConsume(Kind, DiagID, Msg)) {
2090    if (SkipToTok != tok::unknown)
2091      P.SkipUntil(SkipToTok, Parser::StopAtSemi);
2092    return true;
2093  }
2094
2095  if (getDepth() < MaxDepth)
2096    return false;
2097
2098  return diagnoseOverflow();
2099}
2100
2101bool BalancedDelimiterTracker::diagnoseMissingClose() {
2102  assert(!P.Tok.is(Close) && "Should have consumed closing delimiter");
2103
2104  if (P.Tok.is(tok::annot_module_end))
2105    P.Diag(P.Tok, diag::err_missing_before_module_end) << Close;
2106  else
2107    P.Diag(P.Tok, diag::err_expected) << Close;
2108  P.Diag(LOpen, diag::note_matching) << Kind;
2109
2110  // If we're not already at some kind of closing bracket, skip to our closing
2111  // token.
2112  if (P.Tok.isNot(tok::r_paren) && P.Tok.isNot(tok::r_brace) &&
2113      P.Tok.isNot(tok::r_square) &&
2114      P.SkipUntil(Close, FinalToken,
2115                  Parser::StopAtSemi | Parser::StopBeforeMatch) &&
2116      P.Tok.is(Close))
2117    LClose = P.ConsumeAnyToken();
2118  return true;
2119}
2120
2121void BalancedDelimiterTracker::skipToEnd() {
2122  P.SkipUntil(Close, Parser::StopBeforeMatch);
2123  consumeClose();
2124}
2125