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} // end anonymous namespace
42
43IdentifierInfo *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
51Parser::Parser(Preprocessor &pp, Sema &actions, bool skipFunctionBodies)
52  : PP(pp), Actions(actions), Diags(PP.getDiagnostics()),
53    GreaterThanIsOperator(true), ColonIsSacred(false),
54    InMessageExpression(false), TemplateParameterDepth(0),
55    ParsingInObjCContainer(false) {
56  SkipFunctionBodies = pp.isCodeCompletionEnabled() || skipFunctionBodies;
57  Tok.startToken();
58  Tok.setKind(tok::eof);
59  Actions.CurScope = nullptr;
60  NumCachedScopes = 0;
61  ParenCount = BracketCount = BraceCount = 0;
62  CurParsedObjCImpl = nullptr;
63
64  // Add #pragma handlers. These are removed and destroyed in the
65  // destructor.
66  initializePragmaHandlers();
67
68  CommentSemaHandler.reset(new ActionCommentHandler(actions));
69  PP.addCommentHandler(CommentSemaHandler.get());
70
71  PP.setCodeCompletionHandler(*this);
72}
73
74DiagnosticBuilder Parser::Diag(SourceLocation Loc, unsigned DiagID) {
75  return Diags.Report(Loc, DiagID);
76}
77
78DiagnosticBuilder Parser::Diag(const Token &Tok, unsigned DiagID) {
79  return Diag(Tok.getLocation(), DiagID);
80}
81
82/// \brief Emits a diagnostic suggesting parentheses surrounding a
83/// given range.
84///
85/// \param Loc The location where we'll emit the diagnostic.
86/// \param DK The kind of diagnostic to emit.
87/// \param ParenRange Source range enclosing code that should be parenthesized.
88void Parser::SuggestParentheses(SourceLocation Loc, unsigned DK,
89                                SourceRange ParenRange) {
90  SourceLocation EndLoc = PP.getLocForEndOfToken(ParenRange.getEnd());
91  if (!ParenRange.getEnd().isFileID() || EndLoc.isInvalid()) {
92    // We can't display the parentheses, so just dig the
93    // warning/error and return.
94    Diag(Loc, DK);
95    return;
96  }
97
98  Diag(Loc, DK)
99    << FixItHint::CreateInsertion(ParenRange.getBegin(), "(")
100    << FixItHint::CreateInsertion(EndLoc, ")");
101}
102
103static bool IsCommonTypo(tok::TokenKind ExpectedTok, const Token &Tok) {
104  switch (ExpectedTok) {
105  case tok::semi:
106    return Tok.is(tok::colon) || Tok.is(tok::comma); // : or , for ;
107  default: return false;
108  }
109}
110
111bool Parser::ExpectAndConsume(tok::TokenKind ExpectedTok, unsigned DiagID,
112                              const char *Msg) {
113  if (Tok.is(ExpectedTok) || Tok.is(tok::code_completion)) {
114    ConsumeAnyToken();
115    return false;
116  }
117
118  // Detect common single-character typos and resume.
119  if (IsCommonTypo(ExpectedTok, Tok)) {
120    SourceLocation Loc = Tok.getLocation();
121    {
122      DiagnosticBuilder DB = Diag(Loc, DiagID);
123      DB << FixItHint::CreateReplacement(
124                SourceRange(Loc), tok::getPunctuatorSpelling(ExpectedTok));
125      if (DiagID == diag::err_expected)
126        DB << ExpectedTok;
127      else if (DiagID == diag::err_expected_after)
128        DB << Msg << ExpectedTok;
129      else
130        DB << Msg;
131    }
132
133    // Pretend there wasn't a problem.
134    ConsumeAnyToken();
135    return false;
136  }
137
138  SourceLocation EndLoc = PP.getLocForEndOfToken(PrevTokLocation);
139  const char *Spelling = nullptr;
140  if (EndLoc.isValid())
141    Spelling = tok::getPunctuatorSpelling(ExpectedTok);
142
143  DiagnosticBuilder DB =
144      Spelling
145          ? Diag(EndLoc, DiagID) << FixItHint::CreateInsertion(EndLoc, Spelling)
146          : Diag(Tok, DiagID);
147  if (DiagID == diag::err_expected)
148    DB << ExpectedTok;
149  else if (DiagID == diag::err_expected_after)
150    DB << Msg << ExpectedTok;
151  else
152    DB << Msg;
153
154  return true;
155}
156
157bool Parser::ExpectAndConsumeSemi(unsigned DiagID) {
158  if (TryConsumeToken(tok::semi))
159    return false;
160
161  if (Tok.is(tok::code_completion)) {
162    handleUnexpectedCodeCompletionToken();
163    return false;
164  }
165
166  if ((Tok.is(tok::r_paren) || Tok.is(tok::r_square)) &&
167      NextToken().is(tok::semi)) {
168    Diag(Tok, diag::err_extraneous_token_before_semi)
169      << PP.getSpelling(Tok)
170      << FixItHint::CreateRemoval(Tok.getLocation());
171    ConsumeAnyToken(); // The ')' or ']'.
172    ConsumeToken(); // The ';'.
173    return false;
174  }
175
176  return ExpectAndConsume(tok::semi, DiagID);
177}
178
179void Parser::ConsumeExtraSemi(ExtraSemiKind Kind, unsigned TST) {
180  if (!Tok.is(tok::semi)) return;
181
182  bool HadMultipleSemis = false;
183  SourceLocation StartLoc = Tok.getLocation();
184  SourceLocation EndLoc = Tok.getLocation();
185  ConsumeToken();
186
187  while ((Tok.is(tok::semi) && !Tok.isAtStartOfLine())) {
188    HadMultipleSemis = true;
189    EndLoc = Tok.getLocation();
190    ConsumeToken();
191  }
192
193  // C++11 allows extra semicolons at namespace scope, but not in any of the
194  // other contexts.
195  if (Kind == OutsideFunction && getLangOpts().CPlusPlus) {
196    if (getLangOpts().CPlusPlus11)
197      Diag(StartLoc, diag::warn_cxx98_compat_top_level_semi)
198          << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
199    else
200      Diag(StartLoc, diag::ext_extra_semi_cxx11)
201          << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
202    return;
203  }
204
205  if (Kind != AfterMemberFunctionDefinition || HadMultipleSemis)
206    Diag(StartLoc, diag::ext_extra_semi)
207        << Kind << DeclSpec::getSpecifierName((DeclSpec::TST)TST,
208                                    Actions.getASTContext().getPrintingPolicy())
209        << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
210  else
211    // A single semicolon is valid after a member function definition.
212    Diag(StartLoc, diag::warn_extra_semi_after_mem_fn_def)
213      << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
214}
215
216//===----------------------------------------------------------------------===//
217// Error recovery.
218//===----------------------------------------------------------------------===//
219
220static bool HasFlagsSet(Parser::SkipUntilFlags L, Parser::SkipUntilFlags R) {
221  return (static_cast<unsigned>(L) & static_cast<unsigned>(R)) != 0;
222}
223
224/// SkipUntil - Read tokens until we get to the specified token, then consume
225/// it (unless no flag StopBeforeMatch).  Because we cannot guarantee that the
226/// token will ever occur, this skips to the next token, or to some likely
227/// good stopping point.  If StopAtSemi is true, skipping will stop at a ';'
228/// character.
229///
230/// If SkipUntil finds the specified token, it returns true, otherwise it
231/// returns false.
232bool Parser::SkipUntil(ArrayRef<tok::TokenKind> Toks, SkipUntilFlags Flags) {
233  // We always want this function to skip at least one token if the first token
234  // isn't T and if not at EOF.
235  bool isFirstTokenSkipped = true;
236  while (1) {
237    // If we found one of the tokens, stop and return true.
238    for (unsigned i = 0, NumToks = Toks.size(); i != NumToks; ++i) {
239      if (Tok.is(Toks[i])) {
240        if (HasFlagsSet(Flags, StopBeforeMatch)) {
241          // Noop, don't consume the token.
242        } else {
243          ConsumeAnyToken();
244        }
245        return true;
246      }
247    }
248
249    // Important special case: The caller has given up and just wants us to
250    // skip the rest of the file. Do this without recursing, since we can
251    // get here precisely because the caller detected too much recursion.
252    if (Toks.size() == 1 && Toks[0] == tok::eof &&
253        !HasFlagsSet(Flags, StopAtSemi) &&
254        !HasFlagsSet(Flags, StopAtCodeCompletion)) {
255      while (Tok.isNot(tok::eof))
256        ConsumeAnyToken();
257      return true;
258    }
259
260    switch (Tok.getKind()) {
261    case tok::eof:
262      // Ran out of tokens.
263      return false;
264
265    case tok::annot_pragma_openmp_end:
266      // Stop before an OpenMP pragma boundary.
267    case tok::annot_module_begin:
268    case tok::annot_module_end:
269    case tok::annot_module_include:
270      // Stop before we change submodules. They generally indicate a "good"
271      // place to pick up parsing again (except in the special case where
272      // we're trying to skip to EOF).
273      return false;
274
275    case tok::code_completion:
276      if (!HasFlagsSet(Flags, StopAtCodeCompletion))
277        handleUnexpectedCodeCompletionToken();
278      return false;
279
280    case tok::l_paren:
281      // Recursively skip properly-nested parens.
282      ConsumeParen();
283      if (HasFlagsSet(Flags, StopAtCodeCompletion))
284        SkipUntil(tok::r_paren, StopAtCodeCompletion);
285      else
286        SkipUntil(tok::r_paren);
287      break;
288    case tok::l_square:
289      // Recursively skip properly-nested square brackets.
290      ConsumeBracket();
291      if (HasFlagsSet(Flags, StopAtCodeCompletion))
292        SkipUntil(tok::r_square, StopAtCodeCompletion);
293      else
294        SkipUntil(tok::r_square);
295      break;
296    case tok::l_brace:
297      // Recursively skip properly-nested braces.
298      ConsumeBrace();
299      if (HasFlagsSet(Flags, StopAtCodeCompletion))
300        SkipUntil(tok::r_brace, StopAtCodeCompletion);
301      else
302        SkipUntil(tok::r_brace);
303      break;
304
305    // Okay, we found a ']' or '}' or ')', which we think should be balanced.
306    // Since the user wasn't looking for this token (if they were, it would
307    // already be handled), this isn't balanced.  If there is a LHS token at a
308    // higher level, we will assume that this matches the unbalanced token
309    // and return it.  Otherwise, this is a spurious RHS token, which we skip.
310    case tok::r_paren:
311      if (ParenCount && !isFirstTokenSkipped)
312        return false;  // Matches something.
313      ConsumeParen();
314      break;
315    case tok::r_square:
316      if (BracketCount && !isFirstTokenSkipped)
317        return false;  // Matches something.
318      ConsumeBracket();
319      break;
320    case tok::r_brace:
321      if (BraceCount && !isFirstTokenSkipped)
322        return false;  // Matches something.
323      ConsumeBrace();
324      break;
325
326    case tok::string_literal:
327    case tok::wide_string_literal:
328    case tok::utf8_string_literal:
329    case tok::utf16_string_literal:
330    case tok::utf32_string_literal:
331      ConsumeStringToken();
332      break;
333
334    case tok::semi:
335      if (HasFlagsSet(Flags, StopAtSemi))
336        return false;
337      // FALL THROUGH.
338    default:
339      // Skip this token.
340      ConsumeToken();
341      break;
342    }
343    isFirstTokenSkipped = false;
344  }
345}
346
347//===----------------------------------------------------------------------===//
348// Scope manipulation
349//===----------------------------------------------------------------------===//
350
351/// EnterScope - Start a new scope.
352void Parser::EnterScope(unsigned ScopeFlags) {
353  if (NumCachedScopes) {
354    Scope *N = ScopeCache[--NumCachedScopes];
355    N->Init(getCurScope(), ScopeFlags);
356    Actions.CurScope = N;
357  } else {
358    Actions.CurScope = new Scope(getCurScope(), ScopeFlags, Diags);
359  }
360}
361
362/// ExitScope - Pop a scope off the scope stack.
363void Parser::ExitScope() {
364  assert(getCurScope() && "Scope imbalance!");
365
366  // Inform the actions module that this scope is going away if there are any
367  // decls in it.
368  Actions.ActOnPopScope(Tok.getLocation(), getCurScope());
369
370  Scope *OldScope = getCurScope();
371  Actions.CurScope = OldScope->getParent();
372
373  if (NumCachedScopes == ScopeCacheSize)
374    delete OldScope;
375  else
376    ScopeCache[NumCachedScopes++] = OldScope;
377}
378
379/// Set the flags for the current scope to ScopeFlags. If ManageFlags is false,
380/// this object does nothing.
381Parser::ParseScopeFlags::ParseScopeFlags(Parser *Self, unsigned ScopeFlags,
382                                 bool ManageFlags)
383  : CurScope(ManageFlags ? Self->getCurScope() : nullptr) {
384  if (CurScope) {
385    OldFlags = CurScope->getFlags();
386    CurScope->setFlags(ScopeFlags);
387  }
388}
389
390/// Restore the flags for the current scope to what they were before this
391/// object overrode them.
392Parser::ParseScopeFlags::~ParseScopeFlags() {
393  if (CurScope)
394    CurScope->setFlags(OldFlags);
395}
396
397
398//===----------------------------------------------------------------------===//
399// C99 6.9: External Definitions.
400//===----------------------------------------------------------------------===//
401
402Parser::~Parser() {
403  // If we still have scopes active, delete the scope tree.
404  delete getCurScope();
405  Actions.CurScope = nullptr;
406
407  // Free the scope cache.
408  for (unsigned i = 0, e = NumCachedScopes; i != e; ++i)
409    delete ScopeCache[i];
410
411  resetPragmaHandlers();
412
413  PP.removeCommentHandler(CommentSemaHandler.get());
414
415  PP.clearCodeCompletionHandler();
416
417  assert(TemplateIds.empty() && "Still alive TemplateIdAnnotations around?");
418}
419
420/// Initialize - Warm up the parser.
421///
422void Parser::Initialize() {
423  // Create the translation unit scope.  Install it as the current scope.
424  assert(getCurScope() == nullptr && "A scope is already active?");
425  EnterScope(Scope::DeclScope);
426  Actions.ActOnTranslationUnitScope(getCurScope());
427
428  // Initialization for Objective-C context sensitive keywords recognition.
429  // Referenced in Parser::ParseObjCTypeQualifierList.
430  if (getLangOpts().ObjC1) {
431    ObjCTypeQuals[objc_in] = &PP.getIdentifierTable().get("in");
432    ObjCTypeQuals[objc_out] = &PP.getIdentifierTable().get("out");
433    ObjCTypeQuals[objc_inout] = &PP.getIdentifierTable().get("inout");
434    ObjCTypeQuals[objc_oneway] = &PP.getIdentifierTable().get("oneway");
435    ObjCTypeQuals[objc_bycopy] = &PP.getIdentifierTable().get("bycopy");
436    ObjCTypeQuals[objc_byref] = &PP.getIdentifierTable().get("byref");
437  }
438
439  Ident_instancetype = nullptr;
440  Ident_final = nullptr;
441  Ident_sealed = nullptr;
442  Ident_override = nullptr;
443
444  Ident_super = &PP.getIdentifierTable().get("super");
445
446  if (getLangOpts().AltiVec) {
447    Ident_vector = &PP.getIdentifierTable().get("vector");
448    Ident_pixel = &PP.getIdentifierTable().get("pixel");
449    Ident_bool = &PP.getIdentifierTable().get("bool");
450  }
451
452  Ident_introduced = nullptr;
453  Ident_deprecated = nullptr;
454  Ident_obsoleted = nullptr;
455  Ident_unavailable = nullptr;
456
457  Ident__except = nullptr;
458
459  Ident__exception_code = Ident__exception_info = nullptr;
460  Ident__abnormal_termination = Ident___exception_code = nullptr;
461  Ident___exception_info = Ident___abnormal_termination = nullptr;
462  Ident_GetExceptionCode = Ident_GetExceptionInfo = nullptr;
463  Ident_AbnormalTermination = nullptr;
464
465  if(getLangOpts().Borland) {
466    Ident__exception_info        = PP.getIdentifierInfo("_exception_info");
467    Ident___exception_info       = PP.getIdentifierInfo("__exception_info");
468    Ident_GetExceptionInfo       = PP.getIdentifierInfo("GetExceptionInformation");
469    Ident__exception_code        = PP.getIdentifierInfo("_exception_code");
470    Ident___exception_code       = PP.getIdentifierInfo("__exception_code");
471    Ident_GetExceptionCode       = PP.getIdentifierInfo("GetExceptionCode");
472    Ident__abnormal_termination  = PP.getIdentifierInfo("_abnormal_termination");
473    Ident___abnormal_termination = PP.getIdentifierInfo("__abnormal_termination");
474    Ident_AbnormalTermination    = PP.getIdentifierInfo("AbnormalTermination");
475
476    PP.SetPoisonReason(Ident__exception_code,diag::err_seh___except_block);
477    PP.SetPoisonReason(Ident___exception_code,diag::err_seh___except_block);
478    PP.SetPoisonReason(Ident_GetExceptionCode,diag::err_seh___except_block);
479    PP.SetPoisonReason(Ident__exception_info,diag::err_seh___except_filter);
480    PP.SetPoisonReason(Ident___exception_info,diag::err_seh___except_filter);
481    PP.SetPoisonReason(Ident_GetExceptionInfo,diag::err_seh___except_filter);
482    PP.SetPoisonReason(Ident__abnormal_termination,diag::err_seh___finally_block);
483    PP.SetPoisonReason(Ident___abnormal_termination,diag::err_seh___finally_block);
484    PP.SetPoisonReason(Ident_AbnormalTermination,diag::err_seh___finally_block);
485  }
486
487  Actions.Initialize();
488
489  // Prime the lexer look-ahead.
490  ConsumeToken();
491}
492
493namespace {
494  /// \brief RAIIObject to destroy the contents of a SmallVector of
495  /// TemplateIdAnnotation pointers and clear the vector.
496  class DestroyTemplateIdAnnotationsRAIIObj {
497    SmallVectorImpl<TemplateIdAnnotation *> &Container;
498  public:
499    DestroyTemplateIdAnnotationsRAIIObj(SmallVectorImpl<TemplateIdAnnotation *>
500                                       &Container)
501      : Container(Container) {}
502
503    ~DestroyTemplateIdAnnotationsRAIIObj() {
504      for (SmallVectorImpl<TemplateIdAnnotation *>::iterator I =
505           Container.begin(), E = Container.end();
506           I != E; ++I)
507        (*I)->Destroy();
508      Container.clear();
509    }
510  };
511}
512
513/// ParseTopLevelDecl - Parse one top-level declaration, return whatever the
514/// action tells us to.  This returns true if the EOF was encountered.
515bool Parser::ParseTopLevelDecl(DeclGroupPtrTy &Result) {
516  DestroyTemplateIdAnnotationsRAIIObj CleanupRAII(TemplateIds);
517
518  // Skip over the EOF token, flagging end of previous input for incremental
519  // processing
520  if (PP.isIncrementalProcessingEnabled() && Tok.is(tok::eof))
521    ConsumeToken();
522
523  Result = DeclGroupPtrTy();
524  switch (Tok.getKind()) {
525  case tok::annot_pragma_unused:
526    HandlePragmaUnused();
527    return false;
528
529  case tok::annot_module_include:
530    Actions.ActOnModuleInclude(Tok.getLocation(),
531                               reinterpret_cast<Module *>(
532                                   Tok.getAnnotationValue()));
533    ConsumeToken();
534    return false;
535
536  case tok::annot_module_begin:
537  case tok::annot_module_end:
538    // FIXME: Update visibility based on the submodule we're in.
539    ConsumeToken();
540    return false;
541
542  case tok::eof:
543    // Late template parsing can begin.
544    if (getLangOpts().DelayedTemplateParsing)
545      Actions.SetLateTemplateParser(LateTemplateParserCallback, this);
546    if (!PP.isIncrementalProcessingEnabled())
547      Actions.ActOnEndOfTranslationUnit();
548    //else don't tell Sema that we ended parsing: more input might come.
549    return true;
550
551  default:
552    break;
553  }
554
555  ParsedAttributesWithRange attrs(AttrFactory);
556  MaybeParseCXX11Attributes(attrs);
557  MaybeParseMicrosoftAttributes(attrs);
558
559  Result = ParseExternalDeclaration(attrs);
560  return false;
561}
562
563/// ParseExternalDeclaration:
564///
565///       external-declaration: [C99 6.9], declaration: [C++ dcl.dcl]
566///         function-definition
567///         declaration
568/// [GNU]   asm-definition
569/// [GNU]   __extension__ external-declaration
570/// [OBJC]  objc-class-definition
571/// [OBJC]  objc-class-declaration
572/// [OBJC]  objc-alias-declaration
573/// [OBJC]  objc-protocol-definition
574/// [OBJC]  objc-method-definition
575/// [OBJC]  @end
576/// [C++]   linkage-specification
577/// [GNU] asm-definition:
578///         simple-asm-expr ';'
579/// [C++11] empty-declaration
580/// [C++11] attribute-declaration
581///
582/// [C++11] empty-declaration:
583///           ';'
584///
585/// [C++0x/GNU] 'extern' 'template' declaration
586Parser::DeclGroupPtrTy
587Parser::ParseExternalDeclaration(ParsedAttributesWithRange &attrs,
588                                 ParsingDeclSpec *DS) {
589  DestroyTemplateIdAnnotationsRAIIObj CleanupRAII(TemplateIds);
590  ParenBraceBracketBalancer BalancerRAIIObj(*this);
591
592  if (PP.isCodeCompletionReached()) {
593    cutOffParsing();
594    return DeclGroupPtrTy();
595  }
596
597  Decl *SingleDecl = nullptr;
598  switch (Tok.getKind()) {
599  case tok::annot_pragma_vis:
600    HandlePragmaVisibility();
601    return DeclGroupPtrTy();
602  case tok::annot_pragma_pack:
603    HandlePragmaPack();
604    return DeclGroupPtrTy();
605  case tok::annot_pragma_msstruct:
606    HandlePragmaMSStruct();
607    return DeclGroupPtrTy();
608  case tok::annot_pragma_align:
609    HandlePragmaAlign();
610    return DeclGroupPtrTy();
611  case tok::annot_pragma_weak:
612    HandlePragmaWeak();
613    return DeclGroupPtrTy();
614  case tok::annot_pragma_weakalias:
615    HandlePragmaWeakAlias();
616    return DeclGroupPtrTy();
617  case tok::annot_pragma_redefine_extname:
618    HandlePragmaRedefineExtname();
619    return DeclGroupPtrTy();
620  case tok::annot_pragma_fp_contract:
621    HandlePragmaFPContract();
622    return DeclGroupPtrTy();
623  case tok::annot_pragma_opencl_extension:
624    HandlePragmaOpenCLExtension();
625    return DeclGroupPtrTy();
626  case tok::annot_pragma_openmp:
627    ParseOpenMPDeclarativeDirective();
628    return DeclGroupPtrTy();
629  case tok::annot_pragma_ms_pointers_to_members:
630    HandlePragmaMSPointersToMembers();
631    return DeclGroupPtrTy();
632  case tok::annot_pragma_ms_vtordisp:
633    HandlePragmaMSVtorDisp();
634    return DeclGroupPtrTy();
635  case tok::annot_pragma_ms_pragma:
636    HandlePragmaMSPragma();
637    return DeclGroupPtrTy();
638  case tok::semi:
639    // Either a C++11 empty-declaration or attribute-declaration.
640    SingleDecl = Actions.ActOnEmptyDeclaration(getCurScope(),
641                                               attrs.getList(),
642                                               Tok.getLocation());
643    ConsumeExtraSemi(OutsideFunction);
644    break;
645  case tok::r_brace:
646    Diag(Tok, diag::err_extraneous_closing_brace);
647    ConsumeBrace();
648    return DeclGroupPtrTy();
649  case tok::eof:
650    Diag(Tok, diag::err_expected_external_declaration);
651    return DeclGroupPtrTy();
652  case tok::kw___extension__: {
653    // __extension__ silences extension warnings in the subexpression.
654    ExtensionRAIIObject O(Diags);  // Use RAII to do this.
655    ConsumeToken();
656    return ParseExternalDeclaration(attrs);
657  }
658  case tok::kw_asm: {
659    ProhibitAttributes(attrs);
660
661    SourceLocation StartLoc = Tok.getLocation();
662    SourceLocation EndLoc;
663    ExprResult Result(ParseSimpleAsm(&EndLoc));
664
665    ExpectAndConsume(tok::semi, diag::err_expected_after,
666                     "top-level asm block");
667
668    if (Result.isInvalid())
669      return DeclGroupPtrTy();
670    SingleDecl = Actions.ActOnFileScopeAsmDecl(Result.get(), StartLoc, EndLoc);
671    break;
672  }
673  case tok::at:
674    return ParseObjCAtDirectives();
675  case tok::minus:
676  case tok::plus:
677    if (!getLangOpts().ObjC1) {
678      Diag(Tok, diag::err_expected_external_declaration);
679      ConsumeToken();
680      return DeclGroupPtrTy();
681    }
682    SingleDecl = ParseObjCMethodDefinition();
683    break;
684  case tok::code_completion:
685      Actions.CodeCompleteOrdinaryName(getCurScope(),
686                             CurParsedObjCImpl? Sema::PCC_ObjCImplementation
687                                              : Sema::PCC_Namespace);
688    cutOffParsing();
689    return DeclGroupPtrTy();
690  case tok::kw_using:
691  case tok::kw_namespace:
692  case tok::kw_typedef:
693  case tok::kw_template:
694  case tok::kw_export:    // As in 'export template'
695  case tok::kw_static_assert:
696  case tok::kw__Static_assert:
697    // A function definition cannot start with any of these keywords.
698    {
699      SourceLocation DeclEnd;
700      StmtVector Stmts;
701      return ParseDeclaration(Stmts, Declarator::FileContext, DeclEnd, attrs);
702    }
703
704  case tok::kw_static:
705    // Parse (then ignore) 'static' prior to a template instantiation. This is
706    // a GCC extension that we intentionally do not support.
707    if (getLangOpts().CPlusPlus && NextToken().is(tok::kw_template)) {
708      Diag(ConsumeToken(), diag::warn_static_inline_explicit_inst_ignored)
709        << 0;
710      SourceLocation DeclEnd;
711      StmtVector Stmts;
712      return ParseDeclaration(Stmts, Declarator::FileContext, DeclEnd, attrs);
713    }
714    goto dont_know;
715
716  case tok::kw_inline:
717    if (getLangOpts().CPlusPlus) {
718      tok::TokenKind NextKind = NextToken().getKind();
719
720      // Inline namespaces. Allowed as an extension even in C++03.
721      if (NextKind == tok::kw_namespace) {
722        SourceLocation DeclEnd;
723        StmtVector Stmts;
724        return ParseDeclaration(Stmts, Declarator::FileContext, DeclEnd, attrs);
725      }
726
727      // Parse (then ignore) 'inline' prior to a template instantiation. This is
728      // a GCC extension that we intentionally do not support.
729      if (NextKind == tok::kw_template) {
730        Diag(ConsumeToken(), diag::warn_static_inline_explicit_inst_ignored)
731          << 1;
732        SourceLocation DeclEnd;
733        StmtVector Stmts;
734        return ParseDeclaration(Stmts, Declarator::FileContext, DeclEnd, attrs);
735      }
736    }
737    goto dont_know;
738
739  case tok::kw_extern:
740    if (getLangOpts().CPlusPlus && NextToken().is(tok::kw_template)) {
741      // Extern templates
742      SourceLocation ExternLoc = ConsumeToken();
743      SourceLocation TemplateLoc = ConsumeToken();
744      Diag(ExternLoc, getLangOpts().CPlusPlus11 ?
745             diag::warn_cxx98_compat_extern_template :
746             diag::ext_extern_template) << SourceRange(ExternLoc, TemplateLoc);
747      SourceLocation DeclEnd;
748      return Actions.ConvertDeclToDeclGroup(
749                  ParseExplicitInstantiation(Declarator::FileContext,
750                                             ExternLoc, TemplateLoc, DeclEnd));
751    }
752    goto dont_know;
753
754  case tok::kw___if_exists:
755  case tok::kw___if_not_exists:
756    ParseMicrosoftIfExistsExternalDeclaration();
757    return DeclGroupPtrTy();
758
759  default:
760  dont_know:
761    // We can't tell whether this is a function-definition or declaration yet.
762    return ParseDeclarationOrFunctionDefinition(attrs, DS);
763  }
764
765  // This routine returns a DeclGroup, if the thing we parsed only contains a
766  // single decl, convert it now.
767  return Actions.ConvertDeclToDeclGroup(SingleDecl);
768}
769
770/// \brief Determine whether the current token, if it occurs after a
771/// declarator, continues a declaration or declaration list.
772bool Parser::isDeclarationAfterDeclarator() {
773  // Check for '= delete' or '= default'
774  if (getLangOpts().CPlusPlus && Tok.is(tok::equal)) {
775    const Token &KW = NextToken();
776    if (KW.is(tok::kw_default) || KW.is(tok::kw_delete))
777      return false;
778  }
779
780  return Tok.is(tok::equal) ||      // int X()=  -> not a function def
781    Tok.is(tok::comma) ||           // int X(),  -> not a function def
782    Tok.is(tok::semi)  ||           // int X();  -> not a function def
783    Tok.is(tok::kw_asm) ||          // int X() __asm__ -> not a function def
784    Tok.is(tok::kw___attribute) ||  // int X() __attr__ -> not a function def
785    (getLangOpts().CPlusPlus &&
786     Tok.is(tok::l_paren));         // int X(0) -> not a function def [C++]
787}
788
789/// \brief Determine whether the current token, if it occurs after a
790/// declarator, indicates the start of a function definition.
791bool Parser::isStartOfFunctionDefinition(const ParsingDeclarator &Declarator) {
792  assert(Declarator.isFunctionDeclarator() && "Isn't a function declarator");
793  if (Tok.is(tok::l_brace))   // int X() {}
794    return true;
795
796  // Handle K&R C argument lists: int X(f) int f; {}
797  if (!getLangOpts().CPlusPlus &&
798      Declarator.getFunctionTypeInfo().isKNRPrototype())
799    return isDeclarationSpecifier();
800
801  if (getLangOpts().CPlusPlus && Tok.is(tok::equal)) {
802    const Token &KW = NextToken();
803    return KW.is(tok::kw_default) || KW.is(tok::kw_delete);
804  }
805
806  return Tok.is(tok::colon) ||         // X() : Base() {} (used for ctors)
807         Tok.is(tok::kw_try);          // X() try { ... }
808}
809
810/// ParseDeclarationOrFunctionDefinition - Parse either a function-definition or
811/// a declaration.  We can't tell which we have until we read up to the
812/// compound-statement in function-definition. TemplateParams, if
813/// non-NULL, provides the template parameters when we're parsing a
814/// C++ template-declaration.
815///
816///       function-definition: [C99 6.9.1]
817///         decl-specs      declarator declaration-list[opt] compound-statement
818/// [C90] function-definition: [C99 6.7.1] - implicit int result
819/// [C90]   decl-specs[opt] declarator declaration-list[opt] compound-statement
820///
821///       declaration: [C99 6.7]
822///         declaration-specifiers init-declarator-list[opt] ';'
823/// [!C99]  init-declarator-list ';'                   [TODO: warn in c99 mode]
824/// [OMP]   threadprivate-directive                              [TODO]
825///
826Parser::DeclGroupPtrTy
827Parser::ParseDeclOrFunctionDefInternal(ParsedAttributesWithRange &attrs,
828                                       ParsingDeclSpec &DS,
829                                       AccessSpecifier AS) {
830  // Parse the common declaration-specifiers piece.
831  ParseDeclarationSpecifiers(DS, ParsedTemplateInfo(), AS, DSC_top_level);
832
833  // If we had a free-standing type definition with a missing semicolon, we
834  // may get this far before the problem becomes obvious.
835  if (DS.hasTagDefinition() &&
836      DiagnoseMissingSemiAfterTagDefinition(DS, AS, DSC_top_level))
837    return DeclGroupPtrTy();
838
839  // C99 6.7.2.3p6: Handle "struct-or-union identifier;", "enum { X };"
840  // declaration-specifiers init-declarator-list[opt] ';'
841  if (Tok.is(tok::semi)) {
842    ProhibitAttributes(attrs);
843    ConsumeToken();
844    Decl *TheDecl = Actions.ParsedFreeStandingDeclSpec(getCurScope(), AS, DS);
845    DS.complete(TheDecl);
846    return Actions.ConvertDeclToDeclGroup(TheDecl);
847  }
848
849  DS.takeAttributesFrom(attrs);
850
851  // ObjC2 allows prefix attributes on class interfaces and protocols.
852  // FIXME: This still needs better diagnostics. We should only accept
853  // attributes here, no types, etc.
854  if (getLangOpts().ObjC2 && Tok.is(tok::at)) {
855    SourceLocation AtLoc = ConsumeToken(); // the "@"
856    if (!Tok.isObjCAtKeyword(tok::objc_interface) &&
857        !Tok.isObjCAtKeyword(tok::objc_protocol)) {
858      Diag(Tok, diag::err_objc_unexpected_attr);
859      SkipUntil(tok::semi); // FIXME: better skip?
860      return DeclGroupPtrTy();
861    }
862
863    DS.abort();
864
865    const char *PrevSpec = nullptr;
866    unsigned DiagID;
867    if (DS.SetTypeSpecType(DeclSpec::TST_unspecified, AtLoc, PrevSpec, DiagID,
868                           Actions.getASTContext().getPrintingPolicy()))
869      Diag(AtLoc, DiagID) << PrevSpec;
870
871    if (Tok.isObjCAtKeyword(tok::objc_protocol))
872      return ParseObjCAtProtocolDeclaration(AtLoc, DS.getAttributes());
873
874    return Actions.ConvertDeclToDeclGroup(
875            ParseObjCAtInterfaceDeclaration(AtLoc, DS.getAttributes()));
876  }
877
878  // If the declspec consisted only of 'extern' and we have a string
879  // literal following it, this must be a C++ linkage specifier like
880  // 'extern "C"'.
881  if (getLangOpts().CPlusPlus && isTokenStringLiteral() &&
882      DS.getStorageClassSpec() == DeclSpec::SCS_extern &&
883      DS.getParsedSpecifiers() == DeclSpec::PQ_StorageClassSpecifier) {
884    Decl *TheDecl = ParseLinkage(DS, Declarator::FileContext);
885    return Actions.ConvertDeclToDeclGroup(TheDecl);
886  }
887
888  return ParseDeclGroup(DS, Declarator::FileContext, true);
889}
890
891Parser::DeclGroupPtrTy
892Parser::ParseDeclarationOrFunctionDefinition(ParsedAttributesWithRange &attrs,
893                                             ParsingDeclSpec *DS,
894                                             AccessSpecifier AS) {
895  if (DS) {
896    return ParseDeclOrFunctionDefInternal(attrs, *DS, AS);
897  } else {
898    ParsingDeclSpec PDS(*this);
899    // Must temporarily exit the objective-c container scope for
900    // parsing c constructs and re-enter objc container scope
901    // afterwards.
902    ObjCDeclContextSwitch ObjCDC(*this);
903
904    return ParseDeclOrFunctionDefInternal(attrs, PDS, AS);
905  }
906}
907
908/// ParseFunctionDefinition - We parsed and verified that the specified
909/// Declarator is well formed.  If this is a K&R-style function, read the
910/// parameters declaration-list, then start the compound-statement.
911///
912///       function-definition: [C99 6.9.1]
913///         decl-specs      declarator declaration-list[opt] compound-statement
914/// [C90] function-definition: [C99 6.7.1] - implicit int result
915/// [C90]   decl-specs[opt] declarator declaration-list[opt] compound-statement
916/// [C++] function-definition: [C++ 8.4]
917///         decl-specifier-seq[opt] declarator ctor-initializer[opt]
918///         function-body
919/// [C++] function-definition: [C++ 8.4]
920///         decl-specifier-seq[opt] declarator function-try-block
921///
922Decl *Parser::ParseFunctionDefinition(ParsingDeclarator &D,
923                                      const ParsedTemplateInfo &TemplateInfo,
924                                      LateParsedAttrList *LateParsedAttrs) {
925  // Poison the SEH identifiers so they are flagged as illegal in function bodies
926  PoisonSEHIdentifiersRAIIObject PoisonSEHIdentifiers(*this, true);
927  const DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
928
929  // If this is C90 and the declspecs were completely missing, fudge in an
930  // implicit int.  We do this here because this is the only place where
931  // declaration-specifiers are completely optional in the grammar.
932  if (getLangOpts().ImplicitInt && D.getDeclSpec().isEmpty()) {
933    const char *PrevSpec;
934    unsigned DiagID;
935    const PrintingPolicy &Policy = Actions.getASTContext().getPrintingPolicy();
936    D.getMutableDeclSpec().SetTypeSpecType(DeclSpec::TST_int,
937                                           D.getIdentifierLoc(),
938                                           PrevSpec, DiagID,
939                                           Policy);
940    D.SetRangeBegin(D.getDeclSpec().getSourceRange().getBegin());
941  }
942
943  // If this declaration was formed with a K&R-style identifier list for the
944  // arguments, parse declarations for all of the args next.
945  // int foo(a,b) int a; float b; {}
946  if (FTI.isKNRPrototype())
947    ParseKNRParamDeclarations(D);
948
949  // We should have either an opening brace or, in a C++ constructor,
950  // we may have a colon.
951  if (Tok.isNot(tok::l_brace) &&
952      (!getLangOpts().CPlusPlus ||
953       (Tok.isNot(tok::colon) && Tok.isNot(tok::kw_try) &&
954        Tok.isNot(tok::equal)))) {
955    Diag(Tok, diag::err_expected_fn_body);
956
957    // Skip over garbage, until we get to '{'.  Don't eat the '{'.
958    SkipUntil(tok::l_brace, StopAtSemi | StopBeforeMatch);
959
960    // If we didn't find the '{', bail out.
961    if (Tok.isNot(tok::l_brace))
962      return nullptr;
963  }
964
965  // Check to make sure that any normal attributes are allowed to be on
966  // a definition.  Late parsed attributes are checked at the end.
967  if (Tok.isNot(tok::equal)) {
968    AttributeList *DtorAttrs = D.getAttributes();
969    while (DtorAttrs) {
970      if (DtorAttrs->isKnownToGCC() &&
971          !DtorAttrs->isCXX11Attribute()) {
972        Diag(DtorAttrs->getLoc(), diag::warn_attribute_on_function_definition)
973          << DtorAttrs->getName();
974      }
975      DtorAttrs = DtorAttrs->getNext();
976    }
977  }
978
979  // In delayed template parsing mode, for function template we consume the
980  // tokens and store them for late parsing at the end of the translation unit.
981  if (getLangOpts().DelayedTemplateParsing && Tok.isNot(tok::equal) &&
982      TemplateInfo.Kind == ParsedTemplateInfo::Template &&
983      Actions.canDelayFunctionBody(D)) {
984    MultiTemplateParamsArg TemplateParameterLists(*TemplateInfo.TemplateParams);
985
986    ParseScope BodyScope(this, Scope::FnScope|Scope::DeclScope);
987    Scope *ParentScope = getCurScope()->getParent();
988
989    D.setFunctionDefinitionKind(FDK_Definition);
990    Decl *DP = Actions.HandleDeclarator(ParentScope, D,
991                                        TemplateParameterLists);
992    D.complete(DP);
993    D.getMutableDeclSpec().abort();
994
995    CachedTokens Toks;
996    LexTemplateFunctionForLateParsing(Toks);
997
998    if (DP) {
999      FunctionDecl *FnD = DP->getAsFunction();
1000      Actions.CheckForFunctionRedefinition(FnD);
1001      Actions.MarkAsLateParsedTemplate(FnD, DP, Toks);
1002    }
1003    return DP;
1004  }
1005  else if (CurParsedObjCImpl &&
1006           !TemplateInfo.TemplateParams &&
1007           (Tok.is(tok::l_brace) || Tok.is(tok::kw_try) ||
1008            Tok.is(tok::colon)) &&
1009      Actions.CurContext->isTranslationUnit()) {
1010    ParseScope BodyScope(this, Scope::FnScope|Scope::DeclScope);
1011    Scope *ParentScope = getCurScope()->getParent();
1012
1013    D.setFunctionDefinitionKind(FDK_Definition);
1014    Decl *FuncDecl = Actions.HandleDeclarator(ParentScope, D,
1015                                              MultiTemplateParamsArg());
1016    D.complete(FuncDecl);
1017    D.getMutableDeclSpec().abort();
1018    if (FuncDecl) {
1019      // Consume the tokens and store them for later parsing.
1020      StashAwayMethodOrFunctionBodyTokens(FuncDecl);
1021      CurParsedObjCImpl->HasCFunction = true;
1022      return FuncDecl;
1023    }
1024    // FIXME: Should we really fall through here?
1025  }
1026
1027  // Enter a scope for the function body.
1028  ParseScope BodyScope(this, Scope::FnScope|Scope::DeclScope);
1029
1030  // Tell the actions module that we have entered a function definition with the
1031  // specified Declarator for the function.
1032  Decl *Res = TemplateInfo.TemplateParams?
1033      Actions.ActOnStartOfFunctionTemplateDef(getCurScope(),
1034                                              *TemplateInfo.TemplateParams, D)
1035    : Actions.ActOnStartOfFunctionDef(getCurScope(), D);
1036
1037  // Break out of the ParsingDeclarator context before we parse the body.
1038  D.complete(Res);
1039
1040  // Break out of the ParsingDeclSpec context, too.  This const_cast is
1041  // safe because we're always the sole owner.
1042  D.getMutableDeclSpec().abort();
1043
1044  if (TryConsumeToken(tok::equal)) {
1045    assert(getLangOpts().CPlusPlus && "Only C++ function definitions have '='");
1046    Actions.ActOnFinishFunctionBody(Res, nullptr, false);
1047
1048    bool Delete = false;
1049    SourceLocation KWLoc;
1050    if (TryConsumeToken(tok::kw_delete, KWLoc)) {
1051      Diag(KWLoc, getLangOpts().CPlusPlus11
1052                      ? diag::warn_cxx98_compat_deleted_function
1053                      : diag::ext_deleted_function);
1054      Actions.SetDeclDeleted(Res, KWLoc);
1055      Delete = true;
1056    } else if (TryConsumeToken(tok::kw_default, KWLoc)) {
1057      Diag(KWLoc, getLangOpts().CPlusPlus11
1058                      ? diag::warn_cxx98_compat_defaulted_function
1059                      : diag::ext_defaulted_function);
1060      Actions.SetDeclDefaulted(Res, KWLoc);
1061    } else {
1062      llvm_unreachable("function definition after = not 'delete' or 'default'");
1063    }
1064
1065    if (Tok.is(tok::comma)) {
1066      Diag(KWLoc, diag::err_default_delete_in_multiple_declaration)
1067        << Delete;
1068      SkipUntil(tok::semi);
1069    } else if (ExpectAndConsume(tok::semi, diag::err_expected_after,
1070                                Delete ? "delete" : "default")) {
1071      SkipUntil(tok::semi);
1072    }
1073
1074    return Res;
1075  }
1076
1077  if (Tok.is(tok::kw_try))
1078    return ParseFunctionTryBlock(Res, BodyScope);
1079
1080  // If we have a colon, then we're probably parsing a C++
1081  // ctor-initializer.
1082  if (Tok.is(tok::colon)) {
1083    ParseConstructorInitializer(Res);
1084
1085    // Recover from error.
1086    if (!Tok.is(tok::l_brace)) {
1087      BodyScope.Exit();
1088      Actions.ActOnFinishFunctionBody(Res, nullptr);
1089      return Res;
1090    }
1091  } else
1092    Actions.ActOnDefaultCtorInitializers(Res);
1093
1094  // Late attributes are parsed in the same scope as the function body.
1095  if (LateParsedAttrs)
1096    ParseLexedAttributeList(*LateParsedAttrs, Res, false, true);
1097
1098  return ParseFunctionStatementBody(Res, BodyScope);
1099}
1100
1101/// ParseKNRParamDeclarations - Parse 'declaration-list[opt]' which provides
1102/// types for a function with a K&R-style identifier list for arguments.
1103void Parser::ParseKNRParamDeclarations(Declarator &D) {
1104  // We know that the top-level of this declarator is a function.
1105  DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
1106
1107  // Enter function-declaration scope, limiting any declarators to the
1108  // function prototype scope, including parameter declarators.
1109  ParseScope PrototypeScope(this, Scope::FunctionPrototypeScope |
1110                            Scope::FunctionDeclarationScope | Scope::DeclScope);
1111
1112  // Read all the argument declarations.
1113  while (isDeclarationSpecifier()) {
1114    SourceLocation DSStart = Tok.getLocation();
1115
1116    // Parse the common declaration-specifiers piece.
1117    DeclSpec DS(AttrFactory);
1118    ParseDeclarationSpecifiers(DS);
1119
1120    // C99 6.9.1p6: 'each declaration in the declaration list shall have at
1121    // least one declarator'.
1122    // NOTE: GCC just makes this an ext-warn.  It's not clear what it does with
1123    // the declarations though.  It's trivial to ignore them, really hard to do
1124    // anything else with them.
1125    if (TryConsumeToken(tok::semi)) {
1126      Diag(DSStart, diag::err_declaration_does_not_declare_param);
1127      continue;
1128    }
1129
1130    // C99 6.9.1p6: Declarations shall contain no storage-class specifiers other
1131    // than register.
1132    if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
1133        DS.getStorageClassSpec() != DeclSpec::SCS_register) {
1134      Diag(DS.getStorageClassSpecLoc(),
1135           diag::err_invalid_storage_class_in_func_decl);
1136      DS.ClearStorageClassSpecs();
1137    }
1138    if (DS.getThreadStorageClassSpec() != DeclSpec::TSCS_unspecified) {
1139      Diag(DS.getThreadStorageClassSpecLoc(),
1140           diag::err_invalid_storage_class_in_func_decl);
1141      DS.ClearStorageClassSpecs();
1142    }
1143
1144    // Parse the first declarator attached to this declspec.
1145    Declarator ParmDeclarator(DS, Declarator::KNRTypeListContext);
1146    ParseDeclarator(ParmDeclarator);
1147
1148    // Handle the full declarator list.
1149    while (1) {
1150      // If attributes are present, parse them.
1151      MaybeParseGNUAttributes(ParmDeclarator);
1152
1153      // Ask the actions module to compute the type for this declarator.
1154      Decl *Param =
1155        Actions.ActOnParamDeclarator(getCurScope(), ParmDeclarator);
1156
1157      if (Param &&
1158          // A missing identifier has already been diagnosed.
1159          ParmDeclarator.getIdentifier()) {
1160
1161        // Scan the argument list looking for the correct param to apply this
1162        // type.
1163        for (unsigned i = 0; ; ++i) {
1164          // C99 6.9.1p6: those declarators shall declare only identifiers from
1165          // the identifier list.
1166          if (i == FTI.NumParams) {
1167            Diag(ParmDeclarator.getIdentifierLoc(), diag::err_no_matching_param)
1168              << ParmDeclarator.getIdentifier();
1169            break;
1170          }
1171
1172          if (FTI.Params[i].Ident == ParmDeclarator.getIdentifier()) {
1173            // Reject redefinitions of parameters.
1174            if (FTI.Params[i].Param) {
1175              Diag(ParmDeclarator.getIdentifierLoc(),
1176                   diag::err_param_redefinition)
1177                 << ParmDeclarator.getIdentifier();
1178            } else {
1179              FTI.Params[i].Param = Param;
1180            }
1181            break;
1182          }
1183        }
1184      }
1185
1186      // If we don't have a comma, it is either the end of the list (a ';') or
1187      // an error, bail out.
1188      if (Tok.isNot(tok::comma))
1189        break;
1190
1191      ParmDeclarator.clear();
1192
1193      // Consume the comma.
1194      ParmDeclarator.setCommaLoc(ConsumeToken());
1195
1196      // Parse the next declarator.
1197      ParseDeclarator(ParmDeclarator);
1198    }
1199
1200    // Consume ';' and continue parsing.
1201    if (!ExpectAndConsumeSemi(diag::err_expected_semi_declaration))
1202      continue;
1203
1204    // Otherwise recover by skipping to next semi or mandatory function body.
1205    if (SkipUntil(tok::l_brace, StopAtSemi | StopBeforeMatch))
1206      break;
1207    TryConsumeToken(tok::semi);
1208  }
1209
1210  // The actions module must verify that all arguments were declared.
1211  Actions.ActOnFinishKNRParamDeclarations(getCurScope(), D, Tok.getLocation());
1212}
1213
1214
1215/// ParseAsmStringLiteral - This is just a normal string-literal, but is not
1216/// allowed to be a wide string, and is not subject to character translation.
1217///
1218/// [GNU] asm-string-literal:
1219///         string-literal
1220///
1221Parser::ExprResult Parser::ParseAsmStringLiteral() {
1222  switch (Tok.getKind()) {
1223    case tok::string_literal:
1224      break;
1225    case tok::utf8_string_literal:
1226    case tok::utf16_string_literal:
1227    case tok::utf32_string_literal:
1228    case tok::wide_string_literal: {
1229      SourceLocation L = Tok.getLocation();
1230      Diag(Tok, diag::err_asm_operand_wide_string_literal)
1231        << (Tok.getKind() == tok::wide_string_literal)
1232        << SourceRange(L, L);
1233      return ExprError();
1234    }
1235    default:
1236      Diag(Tok, diag::err_expected_string_literal)
1237        << /*Source='in...'*/0 << "'asm'";
1238      return ExprError();
1239  }
1240
1241  return ParseStringLiteralExpression();
1242}
1243
1244/// ParseSimpleAsm
1245///
1246/// [GNU] simple-asm-expr:
1247///         'asm' '(' asm-string-literal ')'
1248///
1249Parser::ExprResult Parser::ParseSimpleAsm(SourceLocation *EndLoc) {
1250  assert(Tok.is(tok::kw_asm) && "Not an asm!");
1251  SourceLocation Loc = ConsumeToken();
1252
1253  if (Tok.is(tok::kw_volatile)) {
1254    // Remove from the end of 'asm' to the end of 'volatile'.
1255    SourceRange RemovalRange(PP.getLocForEndOfToken(Loc),
1256                             PP.getLocForEndOfToken(Tok.getLocation()));
1257
1258    Diag(Tok, diag::warn_file_asm_volatile)
1259      << FixItHint::CreateRemoval(RemovalRange);
1260    ConsumeToken();
1261  }
1262
1263  BalancedDelimiterTracker T(*this, tok::l_paren);
1264  if (T.consumeOpen()) {
1265    Diag(Tok, diag::err_expected_lparen_after) << "asm";
1266    return ExprError();
1267  }
1268
1269  ExprResult Result(ParseAsmStringLiteral());
1270
1271  if (!Result.isInvalid()) {
1272    // Close the paren and get the location of the end bracket
1273    T.consumeClose();
1274    if (EndLoc)
1275      *EndLoc = T.getCloseLocation();
1276  } else if (SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch)) {
1277    if (EndLoc)
1278      *EndLoc = Tok.getLocation();
1279    ConsumeParen();
1280  }
1281
1282  return Result;
1283}
1284
1285/// \brief Get the TemplateIdAnnotation from the token and put it in the
1286/// cleanup pool so that it gets destroyed when parsing the current top level
1287/// declaration is finished.
1288TemplateIdAnnotation *Parser::takeTemplateIdAnnotation(const Token &tok) {
1289  assert(tok.is(tok::annot_template_id) && "Expected template-id token");
1290  TemplateIdAnnotation *
1291      Id = static_cast<TemplateIdAnnotation *>(tok.getAnnotationValue());
1292  return Id;
1293}
1294
1295void Parser::AnnotateScopeToken(CXXScopeSpec &SS, bool IsNewAnnotation) {
1296  // Push the current token back into the token stream (or revert it if it is
1297  // cached) and use an annotation scope token for current token.
1298  if (PP.isBacktrackEnabled())
1299    PP.RevertCachedTokens(1);
1300  else
1301    PP.EnterToken(Tok);
1302  Tok.setKind(tok::annot_cxxscope);
1303  Tok.setAnnotationValue(Actions.SaveNestedNameSpecifierAnnotation(SS));
1304  Tok.setAnnotationRange(SS.getRange());
1305
1306  // In case the tokens were cached, have Preprocessor replace them
1307  // with the annotation token.  We don't need to do this if we've
1308  // just reverted back to a prior state.
1309  if (IsNewAnnotation)
1310    PP.AnnotateCachedTokens(Tok);
1311}
1312
1313/// \brief Attempt to classify the name at the current token position. This may
1314/// form a type, scope or primary expression annotation, or replace the token
1315/// with a typo-corrected keyword. This is only appropriate when the current
1316/// name must refer to an entity which has already been declared.
1317///
1318/// \param IsAddressOfOperand Must be \c true if the name is preceded by an '&'
1319///        and might possibly have a dependent nested name specifier.
1320/// \param CCC Indicates how to perform typo-correction for this name. If NULL,
1321///        no typo correction will be performed.
1322Parser::AnnotatedNameKind
1323Parser::TryAnnotateName(bool IsAddressOfOperand,
1324                        CorrectionCandidateCallback *CCC) {
1325  assert(Tok.is(tok::identifier) || Tok.is(tok::annot_cxxscope));
1326
1327  const bool EnteringContext = false;
1328  const bool WasScopeAnnotation = Tok.is(tok::annot_cxxscope);
1329
1330  CXXScopeSpec SS;
1331  if (getLangOpts().CPlusPlus &&
1332      ParseOptionalCXXScopeSpecifier(SS, ParsedType(), EnteringContext))
1333    return ANK_Error;
1334
1335  if (Tok.isNot(tok::identifier) || SS.isInvalid()) {
1336    if (TryAnnotateTypeOrScopeTokenAfterScopeSpec(EnteringContext, false, SS,
1337                                                  !WasScopeAnnotation))
1338      return ANK_Error;
1339    return ANK_Unresolved;
1340  }
1341
1342  IdentifierInfo *Name = Tok.getIdentifierInfo();
1343  SourceLocation NameLoc = Tok.getLocation();
1344
1345  // FIXME: Move the tentative declaration logic into ClassifyName so we can
1346  // typo-correct to tentatively-declared identifiers.
1347  if (isTentativelyDeclared(Name)) {
1348    // Identifier has been tentatively declared, and thus cannot be resolved as
1349    // an expression. Fall back to annotating it as a type.
1350    if (TryAnnotateTypeOrScopeTokenAfterScopeSpec(EnteringContext, false, SS,
1351                                                  !WasScopeAnnotation))
1352      return ANK_Error;
1353    return Tok.is(tok::annot_typename) ? ANK_Success : ANK_TentativeDecl;
1354  }
1355
1356  Token Next = NextToken();
1357
1358  // Look up and classify the identifier. We don't perform any typo-correction
1359  // after a scope specifier, because in general we can't recover from typos
1360  // there (eg, after correcting 'A::tempalte B<X>::C' [sic], we would need to
1361  // jump back into scope specifier parsing).
1362  Sema::NameClassification Classification
1363    = Actions.ClassifyName(getCurScope(), SS, Name, NameLoc, Next,
1364                           IsAddressOfOperand, SS.isEmpty() ? CCC : nullptr);
1365
1366  switch (Classification.getKind()) {
1367  case Sema::NC_Error:
1368    return ANK_Error;
1369
1370  case Sema::NC_Keyword:
1371    // The identifier was typo-corrected to a keyword.
1372    Tok.setIdentifierInfo(Name);
1373    Tok.setKind(Name->getTokenID());
1374    PP.TypoCorrectToken(Tok);
1375    if (SS.isNotEmpty())
1376      AnnotateScopeToken(SS, !WasScopeAnnotation);
1377    // We've "annotated" this as a keyword.
1378    return ANK_Success;
1379
1380  case Sema::NC_Unknown:
1381    // It's not something we know about. Leave it unannotated.
1382    break;
1383
1384  case Sema::NC_Type:
1385    Tok.setKind(tok::annot_typename);
1386    setTypeAnnotation(Tok, Classification.getType());
1387    Tok.setAnnotationEndLoc(NameLoc);
1388    if (SS.isNotEmpty())
1389      Tok.setLocation(SS.getBeginLoc());
1390    PP.AnnotateCachedTokens(Tok);
1391    return ANK_Success;
1392
1393  case Sema::NC_Expression:
1394    Tok.setKind(tok::annot_primary_expr);
1395    setExprAnnotation(Tok, Classification.getExpression());
1396    Tok.setAnnotationEndLoc(NameLoc);
1397    if (SS.isNotEmpty())
1398      Tok.setLocation(SS.getBeginLoc());
1399    PP.AnnotateCachedTokens(Tok);
1400    return ANK_Success;
1401
1402  case Sema::NC_TypeTemplate:
1403    if (Next.isNot(tok::less)) {
1404      // This may be a type template being used as a template template argument.
1405      if (SS.isNotEmpty())
1406        AnnotateScopeToken(SS, !WasScopeAnnotation);
1407      return ANK_TemplateName;
1408    }
1409    // Fall through.
1410  case Sema::NC_VarTemplate:
1411  case Sema::NC_FunctionTemplate: {
1412    // We have a type, variable or function template followed by '<'.
1413    ConsumeToken();
1414    UnqualifiedId Id;
1415    Id.setIdentifier(Name, NameLoc);
1416    if (AnnotateTemplateIdToken(
1417            TemplateTy::make(Classification.getTemplateName()),
1418            Classification.getTemplateNameKind(), SS, SourceLocation(), Id))
1419      return ANK_Error;
1420    return ANK_Success;
1421  }
1422
1423  case Sema::NC_NestedNameSpecifier:
1424    llvm_unreachable("already parsed nested name specifier");
1425  }
1426
1427  // Unable to classify the name, but maybe we can annotate a scope specifier.
1428  if (SS.isNotEmpty())
1429    AnnotateScopeToken(SS, !WasScopeAnnotation);
1430  return ANK_Unresolved;
1431}
1432
1433bool Parser::TryKeywordIdentFallback(bool DisableKeyword) {
1434  assert(!Tok.is(tok::identifier) && !Tok.isAnnotation());
1435  Diag(Tok, diag::ext_keyword_as_ident)
1436    << PP.getSpelling(Tok)
1437    << DisableKeyword;
1438  if (DisableKeyword) {
1439    IdentifierInfo *II = Tok.getIdentifierInfo();
1440    ContextualKeywords[II] = Tok.getKind();
1441    II->RevertTokenIDToIdentifier();
1442  }
1443  Tok.setKind(tok::identifier);
1444  return true;
1445}
1446
1447bool Parser::TryIdentKeywordUpgrade() {
1448  assert(Tok.is(tok::identifier));
1449  const IdentifierInfo *II = Tok.getIdentifierInfo();
1450  assert(II->hasRevertedTokenIDToIdentifier());
1451  // If we find that this is in fact the name of a type trait,
1452  // update the token kind in place and parse again to treat it as
1453  // the appropriate kind of type trait.
1454  llvm::SmallDenseMap<const IdentifierInfo *, tok::TokenKind>::iterator Known =
1455      ContextualKeywords.find(II);
1456  if (Known == ContextualKeywords.end())
1457    return false;
1458  Tok.setKind(Known->second);
1459  return true;
1460}
1461
1462/// TryAnnotateTypeOrScopeToken - If the current token position is on a
1463/// typename (possibly qualified in C++) or a C++ scope specifier not followed
1464/// by a typename, TryAnnotateTypeOrScopeToken will replace one or more tokens
1465/// with a single annotation token representing the typename or C++ scope
1466/// respectively.
1467/// This simplifies handling of C++ scope specifiers and allows efficient
1468/// backtracking without the need to re-parse and resolve nested-names and
1469/// typenames.
1470/// It will mainly be called when we expect to treat identifiers as typenames
1471/// (if they are typenames). For example, in C we do not expect identifiers
1472/// inside expressions to be treated as typenames so it will not be called
1473/// for expressions in C.
1474/// The benefit for C/ObjC is that a typename will be annotated and
1475/// Actions.getTypeName will not be needed to be called again (e.g. getTypeName
1476/// will not be called twice, once to check whether we have a declaration
1477/// specifier, and another one to get the actual type inside
1478/// ParseDeclarationSpecifiers).
1479///
1480/// This returns true if an error occurred.
1481///
1482/// Note that this routine emits an error if you call it with ::new or ::delete
1483/// as the current tokens, so only call it in contexts where these are invalid.
1484bool Parser::TryAnnotateTypeOrScopeToken(bool EnteringContext, bool NeedType) {
1485  assert((Tok.is(tok::identifier) || Tok.is(tok::coloncolon)
1486          || Tok.is(tok::kw_typename) || Tok.is(tok::annot_cxxscope)
1487          || Tok.is(tok::kw_decltype) || Tok.is(tok::annot_template_id))
1488          && "Cannot be a type or scope token!");
1489
1490  if (Tok.is(tok::kw_typename)) {
1491    // MSVC lets you do stuff like:
1492    //   typename typedef T_::D D;
1493    //
1494    // We will consume the typedef token here and put it back after we have
1495    // parsed the first identifier, transforming it into something more like:
1496    //   typename T_::D typedef D;
1497    if (getLangOpts().MSVCCompat && NextToken().is(tok::kw_typedef)) {
1498      Token TypedefToken;
1499      PP.Lex(TypedefToken);
1500      bool Result = TryAnnotateTypeOrScopeToken(EnteringContext, NeedType);
1501      PP.EnterToken(Tok);
1502      Tok = TypedefToken;
1503      if (!Result)
1504        Diag(Tok.getLocation(), diag::warn_expected_qualified_after_typename);
1505      return Result;
1506    }
1507
1508    // Parse a C++ typename-specifier, e.g., "typename T::type".
1509    //
1510    //   typename-specifier:
1511    //     'typename' '::' [opt] nested-name-specifier identifier
1512    //     'typename' '::' [opt] nested-name-specifier template [opt]
1513    //            simple-template-id
1514    SourceLocation TypenameLoc = ConsumeToken();
1515    CXXScopeSpec SS;
1516    if (ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/ParsedType(),
1517                                       /*EnteringContext=*/false,
1518                                       nullptr, /*IsTypename*/ true))
1519      return true;
1520    if (!SS.isSet()) {
1521      if (Tok.is(tok::identifier) || Tok.is(tok::annot_template_id) ||
1522          Tok.is(tok::annot_decltype)) {
1523        // Attempt to recover by skipping the invalid 'typename'
1524        if (Tok.is(tok::annot_decltype) ||
1525            (!TryAnnotateTypeOrScopeToken(EnteringContext, NeedType) &&
1526             Tok.isAnnotation())) {
1527          unsigned DiagID = diag::err_expected_qualified_after_typename;
1528          // MS compatibility: MSVC permits using known types with typename.
1529          // e.g. "typedef typename T* pointer_type"
1530          if (getLangOpts().MicrosoftExt)
1531            DiagID = diag::warn_expected_qualified_after_typename;
1532          Diag(Tok.getLocation(), DiagID);
1533          return false;
1534        }
1535      }
1536
1537      Diag(Tok.getLocation(), diag::err_expected_qualified_after_typename);
1538      return true;
1539    }
1540
1541    TypeResult Ty;
1542    if (Tok.is(tok::identifier)) {
1543      // FIXME: check whether the next token is '<', first!
1544      Ty = Actions.ActOnTypenameType(getCurScope(), TypenameLoc, SS,
1545                                     *Tok.getIdentifierInfo(),
1546                                     Tok.getLocation());
1547    } else if (Tok.is(tok::annot_template_id)) {
1548      TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
1549      if (TemplateId->Kind != TNK_Type_template &&
1550          TemplateId->Kind != TNK_Dependent_template_name) {
1551        Diag(Tok, diag::err_typename_refers_to_non_type_template)
1552          << Tok.getAnnotationRange();
1553        return true;
1554      }
1555
1556      ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
1557                                         TemplateId->NumArgs);
1558
1559      Ty = Actions.ActOnTypenameType(getCurScope(), TypenameLoc, SS,
1560                                     TemplateId->TemplateKWLoc,
1561                                     TemplateId->Template,
1562                                     TemplateId->TemplateNameLoc,
1563                                     TemplateId->LAngleLoc,
1564                                     TemplateArgsPtr,
1565                                     TemplateId->RAngleLoc);
1566    } else {
1567      Diag(Tok, diag::err_expected_type_name_after_typename)
1568        << SS.getRange();
1569      return true;
1570    }
1571
1572    SourceLocation EndLoc = Tok.getLastLoc();
1573    Tok.setKind(tok::annot_typename);
1574    setTypeAnnotation(Tok, Ty.isInvalid() ? ParsedType() : Ty.get());
1575    Tok.setAnnotationEndLoc(EndLoc);
1576    Tok.setLocation(TypenameLoc);
1577    PP.AnnotateCachedTokens(Tok);
1578    return false;
1579  }
1580
1581  // Remembers whether the token was originally a scope annotation.
1582  bool WasScopeAnnotation = Tok.is(tok::annot_cxxscope);
1583
1584  CXXScopeSpec SS;
1585  if (getLangOpts().CPlusPlus)
1586    if (ParseOptionalCXXScopeSpecifier(SS, ParsedType(), EnteringContext))
1587      return true;
1588
1589  return TryAnnotateTypeOrScopeTokenAfterScopeSpec(EnteringContext, NeedType,
1590                                                   SS, !WasScopeAnnotation);
1591}
1592
1593/// \brief Try to annotate a type or scope token, having already parsed an
1594/// optional scope specifier. \p IsNewScope should be \c true unless the scope
1595/// specifier was extracted from an existing tok::annot_cxxscope annotation.
1596bool Parser::TryAnnotateTypeOrScopeTokenAfterScopeSpec(bool EnteringContext,
1597                                                       bool NeedType,
1598                                                       CXXScopeSpec &SS,
1599                                                       bool IsNewScope) {
1600  if (Tok.is(tok::identifier)) {
1601    IdentifierInfo *CorrectedII = nullptr;
1602    // Determine whether the identifier is a type name.
1603    if (ParsedType Ty = Actions.getTypeName(*Tok.getIdentifierInfo(),
1604                                            Tok.getLocation(), getCurScope(),
1605                                            &SS, false,
1606                                            NextToken().is(tok::period),
1607                                            ParsedType(),
1608                                            /*IsCtorOrDtorName=*/false,
1609                                            /*NonTrivialTypeSourceInfo*/ true,
1610                                            NeedType ? &CorrectedII
1611                                                     : nullptr)) {
1612      // A FixIt was applied as a result of typo correction
1613      if (CorrectedII)
1614        Tok.setIdentifierInfo(CorrectedII);
1615      // This is a typename. Replace the current token in-place with an
1616      // annotation type token.
1617      Tok.setKind(tok::annot_typename);
1618      setTypeAnnotation(Tok, Ty);
1619      Tok.setAnnotationEndLoc(Tok.getLocation());
1620      if (SS.isNotEmpty()) // it was a C++ qualified type name.
1621        Tok.setLocation(SS.getBeginLoc());
1622
1623      // In case the tokens were cached, have Preprocessor replace
1624      // them with the annotation token.
1625      PP.AnnotateCachedTokens(Tok);
1626      return false;
1627    }
1628
1629    if (!getLangOpts().CPlusPlus) {
1630      // If we're in C, we can't have :: tokens at all (the lexer won't return
1631      // them).  If the identifier is not a type, then it can't be scope either,
1632      // just early exit.
1633      return false;
1634    }
1635
1636    // If this is a template-id, annotate with a template-id or type token.
1637    if (NextToken().is(tok::less)) {
1638      TemplateTy Template;
1639      UnqualifiedId TemplateName;
1640      TemplateName.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
1641      bool MemberOfUnknownSpecialization;
1642      if (TemplateNameKind TNK
1643          = Actions.isTemplateName(getCurScope(), SS,
1644                                   /*hasTemplateKeyword=*/false, TemplateName,
1645                                   /*ObjectType=*/ ParsedType(),
1646                                   EnteringContext,
1647                                   Template, MemberOfUnknownSpecialization)) {
1648        // Consume the identifier.
1649        ConsumeToken();
1650        if (AnnotateTemplateIdToken(Template, TNK, SS, SourceLocation(),
1651                                    TemplateName)) {
1652          // If an unrecoverable error occurred, we need to return true here,
1653          // because the token stream is in a damaged state.  We may not return
1654          // a valid identifier.
1655          return true;
1656        }
1657      }
1658    }
1659
1660    // The current token, which is either an identifier or a
1661    // template-id, is not part of the annotation. Fall through to
1662    // push that token back into the stream and complete the C++ scope
1663    // specifier annotation.
1664  }
1665
1666  if (Tok.is(tok::annot_template_id)) {
1667    TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
1668    if (TemplateId->Kind == TNK_Type_template) {
1669      // A template-id that refers to a type was parsed into a
1670      // template-id annotation in a context where we weren't allowed
1671      // to produce a type annotation token. Update the template-id
1672      // annotation token to a type annotation token now.
1673      AnnotateTemplateIdTokenAsType();
1674      return false;
1675    }
1676  }
1677
1678  if (SS.isEmpty())
1679    return false;
1680
1681  // A C++ scope specifier that isn't followed by a typename.
1682  AnnotateScopeToken(SS, IsNewScope);
1683  return false;
1684}
1685
1686/// TryAnnotateScopeToken - Like TryAnnotateTypeOrScopeToken but only
1687/// annotates C++ scope specifiers and template-ids.  This returns
1688/// true if there was an error that could not be recovered from.
1689///
1690/// Note that this routine emits an error if you call it with ::new or ::delete
1691/// as the current tokens, so only call it in contexts where these are invalid.
1692bool Parser::TryAnnotateCXXScopeToken(bool EnteringContext) {
1693  assert(getLangOpts().CPlusPlus &&
1694         "Call sites of this function should be guarded by checking for C++");
1695  assert((Tok.is(tok::identifier) || Tok.is(tok::coloncolon) ||
1696          (Tok.is(tok::annot_template_id) && NextToken().is(tok::coloncolon)) ||
1697         Tok.is(tok::kw_decltype)) && "Cannot be a type or scope token!");
1698
1699  CXXScopeSpec SS;
1700  if (ParseOptionalCXXScopeSpecifier(SS, ParsedType(), EnteringContext))
1701    return true;
1702  if (SS.isEmpty())
1703    return false;
1704
1705  AnnotateScopeToken(SS, true);
1706  return false;
1707}
1708
1709bool Parser::isTokenEqualOrEqualTypo() {
1710  tok::TokenKind Kind = Tok.getKind();
1711  switch (Kind) {
1712  default:
1713    return false;
1714  case tok::ampequal:            // &=
1715  case tok::starequal:           // *=
1716  case tok::plusequal:           // +=
1717  case tok::minusequal:          // -=
1718  case tok::exclaimequal:        // !=
1719  case tok::slashequal:          // /=
1720  case tok::percentequal:        // %=
1721  case tok::lessequal:           // <=
1722  case tok::lesslessequal:       // <<=
1723  case tok::greaterequal:        // >=
1724  case tok::greatergreaterequal: // >>=
1725  case tok::caretequal:          // ^=
1726  case tok::pipeequal:           // |=
1727  case tok::equalequal:          // ==
1728    Diag(Tok, diag::err_invalid_token_after_declarator_suggest_equal)
1729        << Kind
1730        << FixItHint::CreateReplacement(SourceRange(Tok.getLocation()), "=");
1731  case tok::equal:
1732    return true;
1733  }
1734}
1735
1736SourceLocation Parser::handleUnexpectedCodeCompletionToken() {
1737  assert(Tok.is(tok::code_completion));
1738  PrevTokLocation = Tok.getLocation();
1739
1740  for (Scope *S = getCurScope(); S; S = S->getParent()) {
1741    if (S->getFlags() & Scope::FnScope) {
1742      Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_RecoveryInFunction);
1743      cutOffParsing();
1744      return PrevTokLocation;
1745    }
1746
1747    if (S->getFlags() & Scope::ClassScope) {
1748      Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Class);
1749      cutOffParsing();
1750      return PrevTokLocation;
1751    }
1752  }
1753
1754  Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Namespace);
1755  cutOffParsing();
1756  return PrevTokLocation;
1757}
1758
1759// Anchor the Parser::FieldCallback vtable to this translation unit.
1760// We use a spurious method instead of the destructor because
1761// destroying FieldCallbacks can actually be slightly
1762// performance-sensitive.
1763void Parser::FieldCallback::_anchor() {
1764}
1765
1766// Code-completion pass-through functions
1767
1768void Parser::CodeCompleteDirective(bool InConditional) {
1769  Actions.CodeCompletePreprocessorDirective(InConditional);
1770}
1771
1772void Parser::CodeCompleteInConditionalExclusion() {
1773  Actions.CodeCompleteInPreprocessorConditionalExclusion(getCurScope());
1774}
1775
1776void Parser::CodeCompleteMacroName(bool IsDefinition) {
1777  Actions.CodeCompletePreprocessorMacroName(IsDefinition);
1778}
1779
1780void Parser::CodeCompletePreprocessorExpression() {
1781  Actions.CodeCompletePreprocessorExpression();
1782}
1783
1784void Parser::CodeCompleteMacroArgument(IdentifierInfo *Macro,
1785                                       MacroInfo *MacroInfo,
1786                                       unsigned ArgumentIndex) {
1787  Actions.CodeCompletePreprocessorMacroArgument(getCurScope(), Macro, MacroInfo,
1788                                                ArgumentIndex);
1789}
1790
1791void Parser::CodeCompleteNaturalLanguage() {
1792  Actions.CodeCompleteNaturalLanguage();
1793}
1794
1795bool Parser::ParseMicrosoftIfExistsCondition(IfExistsCondition& Result) {
1796  assert((Tok.is(tok::kw___if_exists) || Tok.is(tok::kw___if_not_exists)) &&
1797         "Expected '__if_exists' or '__if_not_exists'");
1798  Result.IsIfExists = Tok.is(tok::kw___if_exists);
1799  Result.KeywordLoc = ConsumeToken();
1800
1801  BalancedDelimiterTracker T(*this, tok::l_paren);
1802  if (T.consumeOpen()) {
1803    Diag(Tok, diag::err_expected_lparen_after)
1804      << (Result.IsIfExists? "__if_exists" : "__if_not_exists");
1805    return true;
1806  }
1807
1808  // Parse nested-name-specifier.
1809  ParseOptionalCXXScopeSpecifier(Result.SS, ParsedType(),
1810                                 /*EnteringContext=*/false);
1811
1812  // Check nested-name specifier.
1813  if (Result.SS.isInvalid()) {
1814    T.skipToEnd();
1815    return true;
1816  }
1817
1818  // Parse the unqualified-id.
1819  SourceLocation TemplateKWLoc; // FIXME: parsed, but unused.
1820  if (ParseUnqualifiedId(Result.SS, false, true, true, ParsedType(),
1821                         TemplateKWLoc, Result.Name)) {
1822    T.skipToEnd();
1823    return true;
1824  }
1825
1826  if (T.consumeClose())
1827    return true;
1828
1829  // Check if the symbol exists.
1830  switch (Actions.CheckMicrosoftIfExistsSymbol(getCurScope(), Result.KeywordLoc,
1831                                               Result.IsIfExists, Result.SS,
1832                                               Result.Name)) {
1833  case Sema::IER_Exists:
1834    Result.Behavior = Result.IsIfExists ? IEB_Parse : IEB_Skip;
1835    break;
1836
1837  case Sema::IER_DoesNotExist:
1838    Result.Behavior = !Result.IsIfExists ? IEB_Parse : IEB_Skip;
1839    break;
1840
1841  case Sema::IER_Dependent:
1842    Result.Behavior = IEB_Dependent;
1843    break;
1844
1845  case Sema::IER_Error:
1846    return true;
1847  }
1848
1849  return false;
1850}
1851
1852void Parser::ParseMicrosoftIfExistsExternalDeclaration() {
1853  IfExistsCondition Result;
1854  if (ParseMicrosoftIfExistsCondition(Result))
1855    return;
1856
1857  BalancedDelimiterTracker Braces(*this, tok::l_brace);
1858  if (Braces.consumeOpen()) {
1859    Diag(Tok, diag::err_expected) << tok::l_brace;
1860    return;
1861  }
1862
1863  switch (Result.Behavior) {
1864  case IEB_Parse:
1865    // Parse declarations below.
1866    break;
1867
1868  case IEB_Dependent:
1869    llvm_unreachable("Cannot have a dependent external declaration");
1870
1871  case IEB_Skip:
1872    Braces.skipToEnd();
1873    return;
1874  }
1875
1876  // Parse the declarations.
1877  // FIXME: Support module import within __if_exists?
1878  while (Tok.isNot(tok::r_brace) && !isEofOrEom()) {
1879    ParsedAttributesWithRange attrs(AttrFactory);
1880    MaybeParseCXX11Attributes(attrs);
1881    MaybeParseMicrosoftAttributes(attrs);
1882    DeclGroupPtrTy Result = ParseExternalDeclaration(attrs);
1883    if (Result && !getCurScope()->getParent())
1884      Actions.getASTConsumer().HandleTopLevelDecl(Result.get());
1885  }
1886  Braces.consumeClose();
1887}
1888
1889Parser::DeclGroupPtrTy Parser::ParseModuleImport(SourceLocation AtLoc) {
1890  assert(Tok.isObjCAtKeyword(tok::objc_import) &&
1891         "Improper start to module import");
1892  SourceLocation ImportLoc = ConsumeToken();
1893
1894  SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> Path;
1895
1896  // Parse the module path.
1897  do {
1898    if (!Tok.is(tok::identifier)) {
1899      if (Tok.is(tok::code_completion)) {
1900        Actions.CodeCompleteModuleImport(ImportLoc, Path);
1901        cutOffParsing();
1902        return DeclGroupPtrTy();
1903      }
1904
1905      Diag(Tok, diag::err_module_expected_ident);
1906      SkipUntil(tok::semi);
1907      return DeclGroupPtrTy();
1908    }
1909
1910    // Record this part of the module path.
1911    Path.push_back(std::make_pair(Tok.getIdentifierInfo(), Tok.getLocation()));
1912    ConsumeToken();
1913
1914    if (Tok.is(tok::period)) {
1915      ConsumeToken();
1916      continue;
1917    }
1918
1919    break;
1920  } while (true);
1921
1922  if (PP.hadModuleLoaderFatalFailure()) {
1923    // With a fatal failure in the module loader, we abort parsing.
1924    cutOffParsing();
1925    return DeclGroupPtrTy();
1926  }
1927
1928  DeclResult Import = Actions.ActOnModuleImport(AtLoc, ImportLoc, Path);
1929  ExpectAndConsumeSemi(diag::err_module_expected_semi);
1930  if (Import.isInvalid())
1931    return DeclGroupPtrTy();
1932
1933  return Actions.ConvertDeclToDeclGroup(Import.get());
1934}
1935
1936bool BalancedDelimiterTracker::diagnoseOverflow() {
1937  P.Diag(P.Tok, diag::err_bracket_depth_exceeded)
1938    << P.getLangOpts().BracketDepth;
1939  P.Diag(P.Tok, diag::note_bracket_depth);
1940  P.cutOffParsing();
1941  return true;
1942}
1943
1944bool BalancedDelimiterTracker::expectAndConsume(unsigned DiagID,
1945                                                const char *Msg,
1946                                                tok::TokenKind SkipToTok) {
1947  LOpen = P.Tok.getLocation();
1948  if (P.ExpectAndConsume(Kind, DiagID, Msg)) {
1949    if (SkipToTok != tok::unknown)
1950      P.SkipUntil(SkipToTok, Parser::StopAtSemi);
1951    return true;
1952  }
1953
1954  if (getDepth() < MaxDepth)
1955    return false;
1956
1957  return diagnoseOverflow();
1958}
1959
1960bool BalancedDelimiterTracker::diagnoseMissingClose() {
1961  assert(!P.Tok.is(Close) && "Should have consumed closing delimiter");
1962
1963  P.Diag(P.Tok, diag::err_expected) << Close;
1964  P.Diag(LOpen, diag::note_matching) << Kind;
1965
1966  // If we're not already at some kind of closing bracket, skip to our closing
1967  // token.
1968  if (P.Tok.isNot(tok::r_paren) && P.Tok.isNot(tok::r_brace) &&
1969      P.Tok.isNot(tok::r_square) &&
1970      P.SkipUntil(Close, FinalToken,
1971                  Parser::StopAtSemi | Parser::StopBeforeMatch) &&
1972      P.Tok.is(Close))
1973    LClose = P.ConsumeAnyToken();
1974  return true;
1975}
1976
1977void BalancedDelimiterTracker::skipToEnd() {
1978  P.SkipUntil(Close, Parser::StopBeforeMatch);
1979  consumeClose();
1980}
1981