ParseExprCXX.cpp revision 29e3a31b7cbd9f9cdf2cc857a3a805871b6f3f62
1//===--- ParseExprCXX.cpp - C++ Expression Parsing ------------------------===//
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 Expression parsing implementation for C++.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Parse/ParseDiagnostic.h"
15#include "clang/Parse/Parser.h"
16#include "RAIIObjectsForParser.h"
17#include "clang/Sema/DeclSpec.h"
18#include "clang/Sema/Scope.h"
19#include "clang/Sema/ParsedTemplate.h"
20#include "llvm/Support/ErrorHandling.h"
21
22using namespace clang;
23
24static int SelectDigraphErrorMessage(tok::TokenKind Kind) {
25  switch (Kind) {
26    case tok::kw_template:         return 0;
27    case tok::kw_const_cast:       return 1;
28    case tok::kw_dynamic_cast:     return 2;
29    case tok::kw_reinterpret_cast: return 3;
30    case tok::kw_static_cast:      return 4;
31    default:
32      llvm_unreachable("Unknown type for digraph error message.");
33  }
34}
35
36// Are the two tokens adjacent in the same source file?
37static bool AreTokensAdjacent(Preprocessor &PP, Token &First, Token &Second) {
38  SourceManager &SM = PP.getSourceManager();
39  SourceLocation FirstLoc = SM.getSpellingLoc(First.getLocation());
40  SourceLocation FirstEnd = FirstLoc.getLocWithOffset(First.getLength());
41  return FirstEnd == SM.getSpellingLoc(Second.getLocation());
42}
43
44// Suggest fixit for "<::" after a cast.
45static void FixDigraph(Parser &P, Preprocessor &PP, Token &DigraphToken,
46                       Token &ColonToken, tok::TokenKind Kind, bool AtDigraph) {
47  // Pull '<:' and ':' off token stream.
48  if (!AtDigraph)
49    PP.Lex(DigraphToken);
50  PP.Lex(ColonToken);
51
52  SourceRange Range;
53  Range.setBegin(DigraphToken.getLocation());
54  Range.setEnd(ColonToken.getLocation());
55  P.Diag(DigraphToken.getLocation(), diag::err_missing_whitespace_digraph)
56      << SelectDigraphErrorMessage(Kind)
57      << FixItHint::CreateReplacement(Range, "< ::");
58
59  // Update token information to reflect their change in token type.
60  ColonToken.setKind(tok::coloncolon);
61  ColonToken.setLocation(ColonToken.getLocation().getLocWithOffset(-1));
62  ColonToken.setLength(2);
63  DigraphToken.setKind(tok::less);
64  DigraphToken.setLength(1);
65
66  // Push new tokens back to token stream.
67  PP.EnterToken(ColonToken);
68  if (!AtDigraph)
69    PP.EnterToken(DigraphToken);
70}
71
72// Check for '<::' which should be '< ::' instead of '[:' when following
73// a template name.
74void Parser::CheckForTemplateAndDigraph(Token &Next, ParsedType ObjectType,
75                                        bool EnteringContext,
76                                        IdentifierInfo &II, CXXScopeSpec &SS) {
77  if (!Next.is(tok::l_square) || Next.getLength() != 2)
78    return;
79
80  Token SecondToken = GetLookAheadToken(2);
81  if (!SecondToken.is(tok::colon) || !AreTokensAdjacent(PP, Next, SecondToken))
82    return;
83
84  TemplateTy Template;
85  UnqualifiedId TemplateName;
86  TemplateName.setIdentifier(&II, Tok.getLocation());
87  bool MemberOfUnknownSpecialization;
88  if (!Actions.isTemplateName(getCurScope(), SS, /*hasTemplateKeyword=*/false,
89                              TemplateName, ObjectType, EnteringContext,
90                              Template, MemberOfUnknownSpecialization))
91    return;
92
93  FixDigraph(*this, PP, Next, SecondToken, tok::kw_template,
94             /*AtDigraph*/false);
95}
96
97/// \brief Parse global scope or nested-name-specifier if present.
98///
99/// Parses a C++ global scope specifier ('::') or nested-name-specifier (which
100/// may be preceded by '::'). Note that this routine will not parse ::new or
101/// ::delete; it will just leave them in the token stream.
102///
103///       '::'[opt] nested-name-specifier
104///       '::'
105///
106///       nested-name-specifier:
107///         type-name '::'
108///         namespace-name '::'
109///         nested-name-specifier identifier '::'
110///         nested-name-specifier 'template'[opt] simple-template-id '::'
111///
112///
113/// \param SS the scope specifier that will be set to the parsed
114/// nested-name-specifier (or empty)
115///
116/// \param ObjectType if this nested-name-specifier is being parsed following
117/// the "." or "->" of a member access expression, this parameter provides the
118/// type of the object whose members are being accessed.
119///
120/// \param EnteringContext whether we will be entering into the context of
121/// the nested-name-specifier after parsing it.
122///
123/// \param MayBePseudoDestructor When non-NULL, points to a flag that
124/// indicates whether this nested-name-specifier may be part of a
125/// pseudo-destructor name. In this case, the flag will be set false
126/// if we don't actually end up parsing a destructor name. Moreorover,
127/// if we do end up determining that we are parsing a destructor name,
128/// the last component of the nested-name-specifier is not parsed as
129/// part of the scope specifier.
130
131/// member access expression, e.g., the \p T:: in \p p->T::m.
132///
133/// \returns true if there was an error parsing a scope specifier
134bool Parser::ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS,
135                                            ParsedType ObjectType,
136                                            bool EnteringContext,
137                                            bool *MayBePseudoDestructor,
138                                            bool IsTypename) {
139  assert(getLang().CPlusPlus &&
140         "Call sites of this function should be guarded by checking for C++");
141
142  if (Tok.is(tok::annot_cxxscope)) {
143    Actions.RestoreNestedNameSpecifierAnnotation(Tok.getAnnotationValue(),
144                                                 Tok.getAnnotationRange(),
145                                                 SS);
146    ConsumeToken();
147    return false;
148  }
149
150  bool HasScopeSpecifier = false;
151
152  if (Tok.is(tok::coloncolon)) {
153    // ::new and ::delete aren't nested-name-specifiers.
154    tok::TokenKind NextKind = NextToken().getKind();
155    if (NextKind == tok::kw_new || NextKind == tok::kw_delete)
156      return false;
157
158    // '::' - Global scope qualifier.
159    if (Actions.ActOnCXXGlobalScopeSpecifier(getCurScope(), ConsumeToken(), SS))
160      return true;
161
162    HasScopeSpecifier = true;
163  }
164
165  bool CheckForDestructor = false;
166  if (MayBePseudoDestructor && *MayBePseudoDestructor) {
167    CheckForDestructor = true;
168    *MayBePseudoDestructor = false;
169  }
170
171  while (true) {
172    if (HasScopeSpecifier) {
173      // C++ [basic.lookup.classref]p5:
174      //   If the qualified-id has the form
175      //
176      //       ::class-name-or-namespace-name::...
177      //
178      //   the class-name-or-namespace-name is looked up in global scope as a
179      //   class-name or namespace-name.
180      //
181      // To implement this, we clear out the object type as soon as we've
182      // seen a leading '::' or part of a nested-name-specifier.
183      ObjectType = ParsedType();
184
185      if (Tok.is(tok::code_completion)) {
186        // Code completion for a nested-name-specifier, where the code
187        // code completion token follows the '::'.
188        Actions.CodeCompleteQualifiedId(getCurScope(), SS, EnteringContext);
189        // Include code completion token into the range of the scope otherwise
190        // when we try to annotate the scope tokens the dangling code completion
191        // token will cause assertion in
192        // Preprocessor::AnnotatePreviousCachedTokens.
193        SS.setEndLoc(Tok.getLocation());
194        cutOffParsing();
195        return true;
196      }
197    }
198
199    // nested-name-specifier:
200    //   nested-name-specifier 'template'[opt] simple-template-id '::'
201
202    // Parse the optional 'template' keyword, then make sure we have
203    // 'identifier <' after it.
204    if (Tok.is(tok::kw_template)) {
205      // If we don't have a scope specifier or an object type, this isn't a
206      // nested-name-specifier, since they aren't allowed to start with
207      // 'template'.
208      if (!HasScopeSpecifier && !ObjectType)
209        break;
210
211      TentativeParsingAction TPA(*this);
212      SourceLocation TemplateKWLoc = ConsumeToken();
213
214      UnqualifiedId TemplateName;
215      if (Tok.is(tok::identifier)) {
216        // Consume the identifier.
217        TemplateName.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
218        ConsumeToken();
219      } else if (Tok.is(tok::kw_operator)) {
220        if (ParseUnqualifiedIdOperator(SS, EnteringContext, ObjectType,
221                                       TemplateName)) {
222          TPA.Commit();
223          break;
224        }
225
226        if (TemplateName.getKind() != UnqualifiedId::IK_OperatorFunctionId &&
227            TemplateName.getKind() != UnqualifiedId::IK_LiteralOperatorId) {
228          Diag(TemplateName.getSourceRange().getBegin(),
229               diag::err_id_after_template_in_nested_name_spec)
230            << TemplateName.getSourceRange();
231          TPA.Commit();
232          break;
233        }
234      } else {
235        TPA.Revert();
236        break;
237      }
238
239      // If the next token is not '<', we have a qualified-id that refers
240      // to a template name, such as T::template apply, but is not a
241      // template-id.
242      if (Tok.isNot(tok::less)) {
243        TPA.Revert();
244        break;
245      }
246
247      // Commit to parsing the template-id.
248      TPA.Commit();
249      TemplateTy Template;
250      if (TemplateNameKind TNK = Actions.ActOnDependentTemplateName(getCurScope(),
251                                                                TemplateKWLoc,
252                                                                    SS,
253                                                                  TemplateName,
254                                                                    ObjectType,
255                                                                EnteringContext,
256                                                                    Template)) {
257        if (AnnotateTemplateIdToken(Template, TNK, SS, TemplateName,
258                                    TemplateKWLoc, false))
259          return true;
260      } else
261        return true;
262
263      continue;
264    }
265
266    if (Tok.is(tok::annot_template_id) && NextToken().is(tok::coloncolon)) {
267      // We have
268      //
269      //   simple-template-id '::'
270      //
271      // So we need to check whether the simple-template-id is of the
272      // right kind (it should name a type or be dependent), and then
273      // convert it into a type within the nested-name-specifier.
274      TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
275      if (CheckForDestructor && GetLookAheadToken(2).is(tok::tilde)) {
276        *MayBePseudoDestructor = true;
277        return false;
278      }
279
280      // Consume the template-id token.
281      ConsumeToken();
282
283      assert(Tok.is(tok::coloncolon) && "NextToken() not working properly!");
284      SourceLocation CCLoc = ConsumeToken();
285
286      if (!HasScopeSpecifier)
287        HasScopeSpecifier = true;
288
289      ASTTemplateArgsPtr TemplateArgsPtr(Actions,
290                                         TemplateId->getTemplateArgs(),
291                                         TemplateId->NumArgs);
292
293      if (Actions.ActOnCXXNestedNameSpecifier(getCurScope(),
294                                              /*FIXME:*/SourceLocation(),
295                                              SS,
296                                              TemplateId->Template,
297                                              TemplateId->TemplateNameLoc,
298                                              TemplateId->LAngleLoc,
299                                              TemplateArgsPtr,
300                                              TemplateId->RAngleLoc,
301                                              CCLoc,
302                                              EnteringContext)) {
303        SourceLocation StartLoc
304          = SS.getBeginLoc().isValid()? SS.getBeginLoc()
305                                      : TemplateId->TemplateNameLoc;
306        SS.SetInvalid(SourceRange(StartLoc, CCLoc));
307      }
308
309      continue;
310    }
311
312
313    // The rest of the nested-name-specifier possibilities start with
314    // tok::identifier.
315    if (Tok.isNot(tok::identifier))
316      break;
317
318    IdentifierInfo &II = *Tok.getIdentifierInfo();
319
320    // nested-name-specifier:
321    //   type-name '::'
322    //   namespace-name '::'
323    //   nested-name-specifier identifier '::'
324    Token Next = NextToken();
325
326    // If we get foo:bar, this is almost certainly a typo for foo::bar.  Recover
327    // and emit a fixit hint for it.
328    if (Next.is(tok::colon) && !ColonIsSacred) {
329      if (Actions.IsInvalidUnlessNestedName(getCurScope(), SS, II,
330                                            Tok.getLocation(),
331                                            Next.getLocation(), ObjectType,
332                                            EnteringContext) &&
333          // If the token after the colon isn't an identifier, it's still an
334          // error, but they probably meant something else strange so don't
335          // recover like this.
336          PP.LookAhead(1).is(tok::identifier)) {
337        Diag(Next, diag::err_unexected_colon_in_nested_name_spec)
338          << FixItHint::CreateReplacement(Next.getLocation(), "::");
339
340        // Recover as if the user wrote '::'.
341        Next.setKind(tok::coloncolon);
342      }
343    }
344
345    if (Next.is(tok::coloncolon)) {
346      if (CheckForDestructor && GetLookAheadToken(2).is(tok::tilde) &&
347          !Actions.isNonTypeNestedNameSpecifier(getCurScope(), SS, Tok.getLocation(),
348                                                II, ObjectType)) {
349        *MayBePseudoDestructor = true;
350        return false;
351      }
352
353      // We have an identifier followed by a '::'. Lookup this name
354      // as the name in a nested-name-specifier.
355      SourceLocation IdLoc = ConsumeToken();
356      assert((Tok.is(tok::coloncolon) || Tok.is(tok::colon)) &&
357             "NextToken() not working properly!");
358      SourceLocation CCLoc = ConsumeToken();
359
360      HasScopeSpecifier = true;
361      if (Actions.ActOnCXXNestedNameSpecifier(getCurScope(), II, IdLoc, CCLoc,
362                                              ObjectType, EnteringContext, SS))
363        SS.SetInvalid(SourceRange(IdLoc, CCLoc));
364
365      continue;
366    }
367
368    CheckForTemplateAndDigraph(Next, ObjectType, EnteringContext, II, SS);
369
370    // nested-name-specifier:
371    //   type-name '<'
372    if (Next.is(tok::less)) {
373      TemplateTy Template;
374      UnqualifiedId TemplateName;
375      TemplateName.setIdentifier(&II, Tok.getLocation());
376      bool MemberOfUnknownSpecialization;
377      if (TemplateNameKind TNK = Actions.isTemplateName(getCurScope(), SS,
378                                              /*hasTemplateKeyword=*/false,
379                                                        TemplateName,
380                                                        ObjectType,
381                                                        EnteringContext,
382                                                        Template,
383                                              MemberOfUnknownSpecialization)) {
384        // We have found a template name, so annotate this this token
385        // with a template-id annotation. We do not permit the
386        // template-id to be translated into a type annotation,
387        // because some clients (e.g., the parsing of class template
388        // specializations) still want to see the original template-id
389        // token.
390        ConsumeToken();
391        if (AnnotateTemplateIdToken(Template, TNK, SS, TemplateName,
392                                    SourceLocation(), false))
393          return true;
394        continue;
395      }
396
397      if (MemberOfUnknownSpecialization && (ObjectType || SS.isSet()) &&
398          (IsTypename || IsTemplateArgumentList(1))) {
399        // We have something like t::getAs<T>, where getAs is a
400        // member of an unknown specialization. However, this will only
401        // parse correctly as a template, so suggest the keyword 'template'
402        // before 'getAs' and treat this as a dependent template name.
403        unsigned DiagID = diag::err_missing_dependent_template_keyword;
404        if (getLang().MicrosoftExt)
405          DiagID = diag::warn_missing_dependent_template_keyword;
406
407        Diag(Tok.getLocation(), DiagID)
408          << II.getName()
409          << FixItHint::CreateInsertion(Tok.getLocation(), "template ");
410
411        if (TemplateNameKind TNK
412              = Actions.ActOnDependentTemplateName(getCurScope(),
413                                                   Tok.getLocation(), SS,
414                                                   TemplateName, ObjectType,
415                                                   EnteringContext, Template)) {
416          // Consume the identifier.
417          ConsumeToken();
418          if (AnnotateTemplateIdToken(Template, TNK, SS, TemplateName,
419                                      SourceLocation(), false))
420            return true;
421        }
422        else
423          return true;
424
425        continue;
426      }
427    }
428
429    // We don't have any tokens that form the beginning of a
430    // nested-name-specifier, so we're done.
431    break;
432  }
433
434  // Even if we didn't see any pieces of a nested-name-specifier, we
435  // still check whether there is a tilde in this position, which
436  // indicates a potential pseudo-destructor.
437  if (CheckForDestructor && Tok.is(tok::tilde))
438    *MayBePseudoDestructor = true;
439
440  return false;
441}
442
443/// ParseCXXIdExpression - Handle id-expression.
444///
445///       id-expression:
446///         unqualified-id
447///         qualified-id
448///
449///       qualified-id:
450///         '::'[opt] nested-name-specifier 'template'[opt] unqualified-id
451///         '::' identifier
452///         '::' operator-function-id
453///         '::' template-id
454///
455/// NOTE: The standard specifies that, for qualified-id, the parser does not
456/// expect:
457///
458///   '::' conversion-function-id
459///   '::' '~' class-name
460///
461/// This may cause a slight inconsistency on diagnostics:
462///
463/// class C {};
464/// namespace A {}
465/// void f() {
466///   :: A :: ~ C(); // Some Sema error about using destructor with a
467///                  // namespace.
468///   :: ~ C(); // Some Parser error like 'unexpected ~'.
469/// }
470///
471/// We simplify the parser a bit and make it work like:
472///
473///       qualified-id:
474///         '::'[opt] nested-name-specifier 'template'[opt] unqualified-id
475///         '::' unqualified-id
476///
477/// That way Sema can handle and report similar errors for namespaces and the
478/// global scope.
479///
480/// The isAddressOfOperand parameter indicates that this id-expression is a
481/// direct operand of the address-of operator. This is, besides member contexts,
482/// the only place where a qualified-id naming a non-static class member may
483/// appear.
484///
485ExprResult Parser::ParseCXXIdExpression(bool isAddressOfOperand) {
486  // qualified-id:
487  //   '::'[opt] nested-name-specifier 'template'[opt] unqualified-id
488  //   '::' unqualified-id
489  //
490  CXXScopeSpec SS;
491  ParseOptionalCXXScopeSpecifier(SS, ParsedType(), false);
492
493  UnqualifiedId Name;
494  if (ParseUnqualifiedId(SS,
495                         /*EnteringContext=*/false,
496                         /*AllowDestructorName=*/false,
497                         /*AllowConstructorName=*/false,
498                         /*ObjectType=*/ ParsedType(),
499                         Name))
500    return ExprError();
501
502  // This is only the direct operand of an & operator if it is not
503  // followed by a postfix-expression suffix.
504  if (isAddressOfOperand && isPostfixExpressionSuffixStart())
505    isAddressOfOperand = false;
506
507  return Actions.ActOnIdExpression(getCurScope(), SS, Name, Tok.is(tok::l_paren),
508                                   isAddressOfOperand);
509
510}
511
512/// ParseLambdaExpression - Parse a C++0x lambda expression.
513///
514///       lambda-expression:
515///         lambda-introducer lambda-declarator[opt] compound-statement
516///
517///       lambda-introducer:
518///         '[' lambda-capture[opt] ']'
519///
520///       lambda-capture:
521///         capture-default
522///         capture-list
523///         capture-default ',' capture-list
524///
525///       capture-default:
526///         '&'
527///         '='
528///
529///       capture-list:
530///         capture
531///         capture-list ',' capture
532///
533///       capture:
534///         identifier
535///         '&' identifier
536///         'this'
537///
538///       lambda-declarator:
539///         '(' parameter-declaration-clause ')' attribute-specifier[opt]
540///           'mutable'[opt] exception-specification[opt]
541///           trailing-return-type[opt]
542///
543ExprResult Parser::ParseLambdaExpression() {
544  // Parse lambda-introducer.
545  LambdaIntroducer Intro;
546
547  llvm::Optional<unsigned> DiagID(ParseLambdaIntroducer(Intro));
548  if (DiagID) {
549    Diag(Tok, DiagID.getValue());
550    SkipUntil(tok::r_square);
551  }
552
553  return ParseLambdaExpressionAfterIntroducer(Intro);
554}
555
556/// TryParseLambdaExpression - Use lookahead and potentially tentative
557/// parsing to determine if we are looking at a C++0x lambda expression, and parse
558/// it if we are.
559///
560/// If we are not looking at a lambda expression, returns ExprError().
561ExprResult Parser::TryParseLambdaExpression() {
562  assert(getLang().CPlusPlus0x
563         && Tok.is(tok::l_square)
564         && "Not at the start of a possible lambda expression.");
565
566  const Token Next = NextToken(), After = GetLookAheadToken(2);
567
568  // If lookahead indicates this is a lambda...
569  if (Next.is(tok::r_square) ||     // []
570      Next.is(tok::equal) ||        // [=
571      (Next.is(tok::amp) &&         // [&] or [&,
572       (After.is(tok::r_square) ||
573        After.is(tok::comma))) ||
574      (Next.is(tok::identifier) &&  // [identifier]
575       After.is(tok::r_square))) {
576    return ParseLambdaExpression();
577  }
578
579  // If lookahead indicates this is an Objective-C message...
580  if (Next.is(tok::identifier) && After.is(tok::identifier)) {
581    return ExprError();
582  }
583
584  LambdaIntroducer Intro;
585  if (TryParseLambdaIntroducer(Intro))
586    return ExprError();
587  return ParseLambdaExpressionAfterIntroducer(Intro);
588}
589
590/// ParseLambdaExpression - Parse a lambda introducer.
591///
592/// Returns a DiagnosticID if it hit something unexpected.
593llvm::Optional<unsigned> Parser::ParseLambdaIntroducer(LambdaIntroducer &Intro) {
594  typedef llvm::Optional<unsigned> DiagResult;
595
596  assert(Tok.is(tok::l_square) && "Lambda expressions begin with '['.");
597  BalancedDelimiterTracker T(*this, tok::l_square);
598  T.consumeOpen();
599
600  Intro.Range.setBegin(T.getOpenLocation());
601
602  bool first = true;
603
604  // Parse capture-default.
605  if (Tok.is(tok::amp) &&
606      (NextToken().is(tok::comma) || NextToken().is(tok::r_square))) {
607    Intro.Default = LCD_ByRef;
608    ConsumeToken();
609    first = false;
610  } else if (Tok.is(tok::equal)) {
611    Intro.Default = LCD_ByCopy;
612    ConsumeToken();
613    first = false;
614  }
615
616  while (Tok.isNot(tok::r_square)) {
617    if (!first) {
618      if (Tok.isNot(tok::comma))
619        return DiagResult(diag::err_expected_comma_or_rsquare);
620      ConsumeToken();
621    }
622
623    first = false;
624
625    // Parse capture.
626    LambdaCaptureKind Kind = LCK_ByCopy;
627    SourceLocation Loc;
628    IdentifierInfo* Id = 0;
629
630    if (Tok.is(tok::kw_this)) {
631      Kind = LCK_This;
632      Loc = ConsumeToken();
633    } else {
634      if (Tok.is(tok::amp)) {
635        Kind = LCK_ByRef;
636        ConsumeToken();
637      }
638
639      if (Tok.is(tok::identifier)) {
640        Id = Tok.getIdentifierInfo();
641        Loc = ConsumeToken();
642      } else if (Tok.is(tok::kw_this)) {
643        // FIXME: If we want to suggest a fixit here, will need to return more
644        // than just DiagnosticID. Perhaps full DiagnosticBuilder that can be
645        // Clear()ed to prevent emission in case of tentative parsing?
646        return DiagResult(diag::err_this_captured_by_reference);
647      } else {
648        return DiagResult(diag::err_expected_capture);
649      }
650    }
651
652    Intro.addCapture(Kind, Loc, Id);
653  }
654
655  T.consumeClose();
656  Intro.Range.setEnd(T.getCloseLocation());
657
658  return DiagResult();
659}
660
661/// TryParseLambdaExpression - Tentatively parse a lambda introducer.
662///
663/// Returns true if it hit something unexpected.
664bool Parser::TryParseLambdaIntroducer(LambdaIntroducer &Intro) {
665  TentativeParsingAction PA(*this);
666
667  llvm::Optional<unsigned> DiagID(ParseLambdaIntroducer(Intro));
668
669  if (DiagID) {
670    PA.Revert();
671    return true;
672  }
673
674  PA.Commit();
675  return false;
676}
677
678/// ParseLambdaExpressionAfterIntroducer - Parse the rest of a lambda
679/// expression.
680ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
681                     LambdaIntroducer &Intro) {
682  // Parse lambda-declarator[opt].
683  DeclSpec DS(AttrFactory);
684  Declarator D(DS, Declarator::PrototypeContext);
685
686  if (Tok.is(tok::l_paren)) {
687    ParseScope PrototypeScope(this,
688                              Scope::FunctionPrototypeScope |
689                              Scope::DeclScope);
690
691    SourceLocation DeclLoc, DeclEndLoc;
692    BalancedDelimiterTracker T(*this, tok::l_paren);
693    T.consumeOpen();
694    DeclLoc = T.getOpenLocation();
695
696    // Parse parameter-declaration-clause.
697    ParsedAttributes Attr(AttrFactory);
698    llvm::SmallVector<DeclaratorChunk::ParamInfo, 16> ParamInfo;
699    SourceLocation EllipsisLoc;
700
701    if (Tok.isNot(tok::r_paren))
702      ParseParameterDeclarationClause(D, Attr, ParamInfo, EllipsisLoc);
703
704    T.consumeClose();
705    DeclEndLoc = T.getCloseLocation();
706
707    // Parse 'mutable'[opt].
708    SourceLocation MutableLoc;
709    if (Tok.is(tok::kw_mutable)) {
710      MutableLoc = ConsumeToken();
711      DeclEndLoc = MutableLoc;
712    }
713
714    // Parse exception-specification[opt].
715    ExceptionSpecificationType ESpecType = EST_None;
716    SourceRange ESpecRange;
717    llvm::SmallVector<ParsedType, 2> DynamicExceptions;
718    llvm::SmallVector<SourceRange, 2> DynamicExceptionRanges;
719    ExprResult NoexceptExpr;
720    ESpecType = MaybeParseExceptionSpecification(ESpecRange,
721                                                 DynamicExceptions,
722                                                 DynamicExceptionRanges,
723                                                 NoexceptExpr);
724
725    if (ESpecType != EST_None)
726      DeclEndLoc = ESpecRange.getEnd();
727
728    // Parse attribute-specifier[opt].
729    MaybeParseCXX0XAttributes(Attr, &DeclEndLoc);
730
731    // Parse trailing-return-type[opt].
732    ParsedType TrailingReturnType;
733    if (Tok.is(tok::arrow)) {
734      SourceRange Range;
735      TrailingReturnType = ParseTrailingReturnType(Range).get();
736      if (Range.getEnd().isValid())
737        DeclEndLoc = Range.getEnd();
738    }
739
740    PrototypeScope.Exit();
741
742    D.AddTypeInfo(DeclaratorChunk::getFunction(/*hasProto=*/true,
743                                           /*isVariadic=*/EllipsisLoc.isValid(),
744                                           EllipsisLoc,
745                                           ParamInfo.data(), ParamInfo.size(),
746                                           DS.getTypeQualifiers(),
747                                           /*RefQualifierIsLValueRef=*/true,
748                                           /*RefQualifierLoc=*/SourceLocation(),
749                                           MutableLoc,
750                                           ESpecType, ESpecRange.getBegin(),
751                                           DynamicExceptions.data(),
752                                           DynamicExceptionRanges.data(),
753                                           DynamicExceptions.size(),
754                                           NoexceptExpr.isUsable() ?
755                                             NoexceptExpr.get() : 0,
756                                           DeclLoc, DeclEndLoc, D,
757                                           TrailingReturnType),
758                  Attr, DeclEndLoc);
759  }
760
761  // Parse compound-statement.
762  if (Tok.is(tok::l_brace)) {
763    // FIXME: Rename BlockScope -> ClosureScope if we decide to continue using
764    // it.
765    ParseScope BodyScope(this, Scope::BlockScope | Scope::FnScope |
766                               Scope::BreakScope | Scope::ContinueScope |
767                               Scope::DeclScope);
768
769    StmtResult Stmt(ParseCompoundStatementBody());
770
771    BodyScope.Exit();
772  } else {
773    Diag(Tok, diag::err_expected_lambda_body);
774  }
775
776  return ExprEmpty();
777}
778
779/// ParseCXXCasts - This handles the various ways to cast expressions to another
780/// type.
781///
782///       postfix-expression: [C++ 5.2p1]
783///         'dynamic_cast' '<' type-name '>' '(' expression ')'
784///         'static_cast' '<' type-name '>' '(' expression ')'
785///         'reinterpret_cast' '<' type-name '>' '(' expression ')'
786///         'const_cast' '<' type-name '>' '(' expression ')'
787///
788ExprResult Parser::ParseCXXCasts() {
789  tok::TokenKind Kind = Tok.getKind();
790  const char *CastName = 0;     // For error messages
791
792  switch (Kind) {
793  default: llvm_unreachable("Unknown C++ cast!");
794  case tok::kw_const_cast:       CastName = "const_cast";       break;
795  case tok::kw_dynamic_cast:     CastName = "dynamic_cast";     break;
796  case tok::kw_reinterpret_cast: CastName = "reinterpret_cast"; break;
797  case tok::kw_static_cast:      CastName = "static_cast";      break;
798  }
799
800  SourceLocation OpLoc = ConsumeToken();
801  SourceLocation LAngleBracketLoc = Tok.getLocation();
802
803  // Check for "<::" which is parsed as "[:".  If found, fix token stream,
804  // diagnose error, suggest fix, and recover parsing.
805  Token Next = NextToken();
806  if (Tok.is(tok::l_square) && Tok.getLength() == 2 && Next.is(tok::colon) &&
807      AreTokensAdjacent(PP, Tok, Next))
808    FixDigraph(*this, PP, Tok, Next, Kind, /*AtDigraph*/true);
809
810  if (ExpectAndConsume(tok::less, diag::err_expected_less_after, CastName))
811    return ExprError();
812
813  // Parse the common declaration-specifiers piece.
814  DeclSpec DS(AttrFactory);
815  ParseSpecifierQualifierList(DS);
816
817  // Parse the abstract-declarator, if present.
818  Declarator DeclaratorInfo(DS, Declarator::TypeNameContext);
819  ParseDeclarator(DeclaratorInfo);
820
821  SourceLocation RAngleBracketLoc = Tok.getLocation();
822
823  if (ExpectAndConsume(tok::greater, diag::err_expected_greater))
824    return ExprError(Diag(LAngleBracketLoc, diag::note_matching) << "<");
825
826  SourceLocation LParenLoc, RParenLoc;
827  BalancedDelimiterTracker T(*this, tok::l_paren);
828
829  if (T.expectAndConsume(diag::err_expected_lparen_after, CastName))
830    return ExprError();
831
832  ExprResult Result = ParseExpression();
833
834  // Match the ')'.
835  T.consumeClose();
836
837  if (!Result.isInvalid() && !DeclaratorInfo.isInvalidType())
838    Result = Actions.ActOnCXXNamedCast(OpLoc, Kind,
839                                       LAngleBracketLoc, DeclaratorInfo,
840                                       RAngleBracketLoc,
841                                       T.getOpenLocation(), Result.take(),
842                                       T.getCloseLocation());
843
844  return move(Result);
845}
846
847/// ParseCXXTypeid - This handles the C++ typeid expression.
848///
849///       postfix-expression: [C++ 5.2p1]
850///         'typeid' '(' expression ')'
851///         'typeid' '(' type-id ')'
852///
853ExprResult Parser::ParseCXXTypeid() {
854  assert(Tok.is(tok::kw_typeid) && "Not 'typeid'!");
855
856  SourceLocation OpLoc = ConsumeToken();
857  SourceLocation LParenLoc, RParenLoc;
858  BalancedDelimiterTracker T(*this, tok::l_paren);
859
860  // typeid expressions are always parenthesized.
861  if (T.expectAndConsume(diag::err_expected_lparen_after, "typeid"))
862    return ExprError();
863  LParenLoc = T.getOpenLocation();
864
865  ExprResult Result;
866
867  if (isTypeIdInParens()) {
868    TypeResult Ty = ParseTypeName();
869
870    // Match the ')'.
871    T.consumeClose();
872    RParenLoc = T.getCloseLocation();
873    if (Ty.isInvalid() || RParenLoc.isInvalid())
874      return ExprError();
875
876    Result = Actions.ActOnCXXTypeid(OpLoc, LParenLoc, /*isType=*/true,
877                                    Ty.get().getAsOpaquePtr(), RParenLoc);
878  } else {
879    // C++0x [expr.typeid]p3:
880    //   When typeid is applied to an expression other than an lvalue of a
881    //   polymorphic class type [...] The expression is an unevaluated
882    //   operand (Clause 5).
883    //
884    // Note that we can't tell whether the expression is an lvalue of a
885    // polymorphic class type until after we've parsed the expression, so
886    // we the expression is potentially potentially evaluated.
887    EnterExpressionEvaluationContext Unevaluated(Actions,
888                                       Sema::PotentiallyPotentiallyEvaluated);
889    Result = ParseExpression();
890
891    // Match the ')'.
892    if (Result.isInvalid())
893      SkipUntil(tok::r_paren);
894    else {
895      T.consumeClose();
896      RParenLoc = T.getCloseLocation();
897      if (RParenLoc.isInvalid())
898        return ExprError();
899
900      Result = Actions.ActOnCXXTypeid(OpLoc, LParenLoc, /*isType=*/false,
901                                      Result.release(), RParenLoc);
902    }
903  }
904
905  return move(Result);
906}
907
908/// ParseCXXUuidof - This handles the Microsoft C++ __uuidof expression.
909///
910///         '__uuidof' '(' expression ')'
911///         '__uuidof' '(' type-id ')'
912///
913ExprResult Parser::ParseCXXUuidof() {
914  assert(Tok.is(tok::kw___uuidof) && "Not '__uuidof'!");
915
916  SourceLocation OpLoc = ConsumeToken();
917  BalancedDelimiterTracker T(*this, tok::l_paren);
918
919  // __uuidof expressions are always parenthesized.
920  if (T.expectAndConsume(diag::err_expected_lparen_after, "__uuidof"))
921    return ExprError();
922
923  ExprResult Result;
924
925  if (isTypeIdInParens()) {
926    TypeResult Ty = ParseTypeName();
927
928    // Match the ')'.
929    T.consumeClose();
930
931    if (Ty.isInvalid())
932      return ExprError();
933
934    Result = Actions.ActOnCXXUuidof(OpLoc, T.getOpenLocation(), /*isType=*/true,
935                                    Ty.get().getAsOpaquePtr(),
936                                    T.getCloseLocation());
937  } else {
938    EnterExpressionEvaluationContext Unevaluated(Actions, Sema::Unevaluated);
939    Result = ParseExpression();
940
941    // Match the ')'.
942    if (Result.isInvalid())
943      SkipUntil(tok::r_paren);
944    else {
945      T.consumeClose();
946
947      Result = Actions.ActOnCXXUuidof(OpLoc, T.getOpenLocation(),
948                                      /*isType=*/false,
949                                      Result.release(), T.getCloseLocation());
950    }
951  }
952
953  return move(Result);
954}
955
956/// \brief Parse a C++ pseudo-destructor expression after the base,
957/// . or -> operator, and nested-name-specifier have already been
958/// parsed.
959///
960///       postfix-expression: [C++ 5.2]
961///         postfix-expression . pseudo-destructor-name
962///         postfix-expression -> pseudo-destructor-name
963///
964///       pseudo-destructor-name:
965///         ::[opt] nested-name-specifier[opt] type-name :: ~type-name
966///         ::[opt] nested-name-specifier template simple-template-id ::
967///                 ~type-name
968///         ::[opt] nested-name-specifier[opt] ~type-name
969///
970ExprResult
971Parser::ParseCXXPseudoDestructor(ExprArg Base, SourceLocation OpLoc,
972                                 tok::TokenKind OpKind,
973                                 CXXScopeSpec &SS,
974                                 ParsedType ObjectType) {
975  // We're parsing either a pseudo-destructor-name or a dependent
976  // member access that has the same form as a
977  // pseudo-destructor-name. We parse both in the same way and let
978  // the action model sort them out.
979  //
980  // Note that the ::[opt] nested-name-specifier[opt] has already
981  // been parsed, and if there was a simple-template-id, it has
982  // been coalesced into a template-id annotation token.
983  UnqualifiedId FirstTypeName;
984  SourceLocation CCLoc;
985  if (Tok.is(tok::identifier)) {
986    FirstTypeName.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
987    ConsumeToken();
988    assert(Tok.is(tok::coloncolon) &&"ParseOptionalCXXScopeSpecifier fail");
989    CCLoc = ConsumeToken();
990  } else if (Tok.is(tok::annot_template_id)) {
991    FirstTypeName.setTemplateId(
992                              (TemplateIdAnnotation *)Tok.getAnnotationValue());
993    ConsumeToken();
994    assert(Tok.is(tok::coloncolon) &&"ParseOptionalCXXScopeSpecifier fail");
995    CCLoc = ConsumeToken();
996  } else {
997    FirstTypeName.setIdentifier(0, SourceLocation());
998  }
999
1000  // Parse the tilde.
1001  assert(Tok.is(tok::tilde) && "ParseOptionalCXXScopeSpecifier fail");
1002  SourceLocation TildeLoc = ConsumeToken();
1003  if (!Tok.is(tok::identifier)) {
1004    Diag(Tok, diag::err_destructor_tilde_identifier);
1005    return ExprError();
1006  }
1007
1008  // Parse the second type.
1009  UnqualifiedId SecondTypeName;
1010  IdentifierInfo *Name = Tok.getIdentifierInfo();
1011  SourceLocation NameLoc = ConsumeToken();
1012  SecondTypeName.setIdentifier(Name, NameLoc);
1013
1014  // If there is a '<', the second type name is a template-id. Parse
1015  // it as such.
1016  if (Tok.is(tok::less) &&
1017      ParseUnqualifiedIdTemplateId(SS, Name, NameLoc, false, ObjectType,
1018                                   SecondTypeName, /*AssumeTemplateName=*/true,
1019                                   /*TemplateKWLoc*/SourceLocation()))
1020    return ExprError();
1021
1022  return Actions.ActOnPseudoDestructorExpr(getCurScope(), Base,
1023                                           OpLoc, OpKind,
1024                                           SS, FirstTypeName, CCLoc,
1025                                           TildeLoc, SecondTypeName,
1026                                           Tok.is(tok::l_paren));
1027}
1028
1029/// ParseCXXBoolLiteral - This handles the C++ Boolean literals.
1030///
1031///       boolean-literal: [C++ 2.13.5]
1032///         'true'
1033///         'false'
1034ExprResult Parser::ParseCXXBoolLiteral() {
1035  tok::TokenKind Kind = Tok.getKind();
1036  return Actions.ActOnCXXBoolLiteral(ConsumeToken(), Kind);
1037}
1038
1039/// ParseThrowExpression - This handles the C++ throw expression.
1040///
1041///       throw-expression: [C++ 15]
1042///         'throw' assignment-expression[opt]
1043ExprResult Parser::ParseThrowExpression() {
1044  assert(Tok.is(tok::kw_throw) && "Not throw!");
1045  SourceLocation ThrowLoc = ConsumeToken();           // Eat the throw token.
1046
1047  // If the current token isn't the start of an assignment-expression,
1048  // then the expression is not present.  This handles things like:
1049  //   "C ? throw : (void)42", which is crazy but legal.
1050  switch (Tok.getKind()) {  // FIXME: move this predicate somewhere common.
1051  case tok::semi:
1052  case tok::r_paren:
1053  case tok::r_square:
1054  case tok::r_brace:
1055  case tok::colon:
1056  case tok::comma:
1057    return Actions.ActOnCXXThrow(getCurScope(), ThrowLoc, 0);
1058
1059  default:
1060    ExprResult Expr(ParseAssignmentExpression());
1061    if (Expr.isInvalid()) return move(Expr);
1062    return Actions.ActOnCXXThrow(getCurScope(), ThrowLoc, Expr.take());
1063  }
1064}
1065
1066/// ParseCXXThis - This handles the C++ 'this' pointer.
1067///
1068/// C++ 9.3.2: In the body of a non-static member function, the keyword this is
1069/// a non-lvalue expression whose value is the address of the object for which
1070/// the function is called.
1071ExprResult Parser::ParseCXXThis() {
1072  assert(Tok.is(tok::kw_this) && "Not 'this'!");
1073  SourceLocation ThisLoc = ConsumeToken();
1074  return Actions.ActOnCXXThis(ThisLoc);
1075}
1076
1077/// ParseCXXTypeConstructExpression - Parse construction of a specified type.
1078/// Can be interpreted either as function-style casting ("int(x)")
1079/// or class type construction ("ClassType(x,y,z)")
1080/// or creation of a value-initialized type ("int()").
1081/// See [C++ 5.2.3].
1082///
1083///       postfix-expression: [C++ 5.2p1]
1084///         simple-type-specifier '(' expression-list[opt] ')'
1085/// [C++0x] simple-type-specifier braced-init-list
1086///         typename-specifier '(' expression-list[opt] ')'
1087/// [C++0x] typename-specifier braced-init-list
1088///
1089ExprResult
1090Parser::ParseCXXTypeConstructExpression(const DeclSpec &DS) {
1091  Declarator DeclaratorInfo(DS, Declarator::TypeNameContext);
1092  ParsedType TypeRep = Actions.ActOnTypeName(getCurScope(), DeclaratorInfo).get();
1093
1094  assert((Tok.is(tok::l_paren) ||
1095          (getLang().CPlusPlus0x && Tok.is(tok::l_brace)))
1096         && "Expected '(' or '{'!");
1097
1098  if (Tok.is(tok::l_brace)) {
1099
1100    // FIXME: Convert to a proper type construct expression.
1101    return ParseBraceInitializer();
1102
1103  } else {
1104    GreaterThanIsOperatorScope G(GreaterThanIsOperator, true);
1105
1106    BalancedDelimiterTracker T(*this, tok::l_paren);
1107    T.consumeOpen();
1108
1109    ExprVector Exprs(Actions);
1110    CommaLocsTy CommaLocs;
1111
1112    if (Tok.isNot(tok::r_paren)) {
1113      if (ParseExpressionList(Exprs, CommaLocs)) {
1114        SkipUntil(tok::r_paren);
1115        return ExprError();
1116      }
1117    }
1118
1119    // Match the ')'.
1120    T.consumeClose();
1121
1122    // TypeRep could be null, if it references an invalid typedef.
1123    if (!TypeRep)
1124      return ExprError();
1125
1126    assert((Exprs.size() == 0 || Exprs.size()-1 == CommaLocs.size())&&
1127           "Unexpected number of commas!");
1128    return Actions.ActOnCXXTypeConstructExpr(TypeRep, T.getOpenLocation(),
1129                                             move_arg(Exprs),
1130                                             T.getCloseLocation());
1131  }
1132}
1133
1134/// ParseCXXCondition - if/switch/while condition expression.
1135///
1136///       condition:
1137///         expression
1138///         type-specifier-seq declarator '=' assignment-expression
1139/// [GNU]   type-specifier-seq declarator simple-asm-expr[opt] attributes[opt]
1140///             '=' assignment-expression
1141///
1142/// \param ExprResult if the condition was parsed as an expression, the
1143/// parsed expression.
1144///
1145/// \param DeclResult if the condition was parsed as a declaration, the
1146/// parsed declaration.
1147///
1148/// \param Loc The location of the start of the statement that requires this
1149/// condition, e.g., the "for" in a for loop.
1150///
1151/// \param ConvertToBoolean Whether the condition expression should be
1152/// converted to a boolean value.
1153///
1154/// \returns true if there was a parsing, false otherwise.
1155bool Parser::ParseCXXCondition(ExprResult &ExprOut,
1156                               Decl *&DeclOut,
1157                               SourceLocation Loc,
1158                               bool ConvertToBoolean) {
1159  if (Tok.is(tok::code_completion)) {
1160    Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Condition);
1161    cutOffParsing();
1162    return true;
1163  }
1164
1165  if (!isCXXConditionDeclaration()) {
1166    // Parse the expression.
1167    ExprOut = ParseExpression(); // expression
1168    DeclOut = 0;
1169    if (ExprOut.isInvalid())
1170      return true;
1171
1172    // If required, convert to a boolean value.
1173    if (ConvertToBoolean)
1174      ExprOut
1175        = Actions.ActOnBooleanCondition(getCurScope(), Loc, ExprOut.get());
1176    return ExprOut.isInvalid();
1177  }
1178
1179  // type-specifier-seq
1180  DeclSpec DS(AttrFactory);
1181  ParseSpecifierQualifierList(DS);
1182
1183  // declarator
1184  Declarator DeclaratorInfo(DS, Declarator::ConditionContext);
1185  ParseDeclarator(DeclaratorInfo);
1186
1187  // simple-asm-expr[opt]
1188  if (Tok.is(tok::kw_asm)) {
1189    SourceLocation Loc;
1190    ExprResult AsmLabel(ParseSimpleAsm(&Loc));
1191    if (AsmLabel.isInvalid()) {
1192      SkipUntil(tok::semi);
1193      return true;
1194    }
1195    DeclaratorInfo.setAsmLabel(AsmLabel.release());
1196    DeclaratorInfo.SetRangeEnd(Loc);
1197  }
1198
1199  // If attributes are present, parse them.
1200  MaybeParseGNUAttributes(DeclaratorInfo);
1201
1202  // Type-check the declaration itself.
1203  DeclResult Dcl = Actions.ActOnCXXConditionDeclaration(getCurScope(),
1204                                                        DeclaratorInfo);
1205  DeclOut = Dcl.get();
1206  ExprOut = ExprError();
1207
1208  // '=' assignment-expression
1209  if (isTokenEqualOrMistypedEqualEqual(
1210                               diag::err_invalid_equalequal_after_declarator)) {
1211    ConsumeToken();
1212    ExprResult AssignExpr(ParseAssignmentExpression());
1213    if (!AssignExpr.isInvalid())
1214      Actions.AddInitializerToDecl(DeclOut, AssignExpr.take(), false,
1215                                   DS.getTypeSpecType() == DeclSpec::TST_auto);
1216  } else {
1217    // FIXME: C++0x allows a braced-init-list
1218    Diag(Tok, diag::err_expected_equal_after_declarator);
1219  }
1220
1221  // FIXME: Build a reference to this declaration? Convert it to bool?
1222  // (This is currently handled by Sema).
1223
1224  Actions.FinalizeDeclaration(DeclOut);
1225
1226  return false;
1227}
1228
1229/// \brief Determine whether the current token starts a C++
1230/// simple-type-specifier.
1231bool Parser::isCXXSimpleTypeSpecifier() const {
1232  switch (Tok.getKind()) {
1233  case tok::annot_typename:
1234  case tok::kw_short:
1235  case tok::kw_long:
1236  case tok::kw___int64:
1237  case tok::kw_signed:
1238  case tok::kw_unsigned:
1239  case tok::kw_void:
1240  case tok::kw_char:
1241  case tok::kw_int:
1242  case tok::kw_half:
1243  case tok::kw_float:
1244  case tok::kw_double:
1245  case tok::kw_wchar_t:
1246  case tok::kw_char16_t:
1247  case tok::kw_char32_t:
1248  case tok::kw_bool:
1249  case tok::kw_decltype:
1250  case tok::kw_typeof:
1251  case tok::kw___underlying_type:
1252    return true;
1253
1254  default:
1255    break;
1256  }
1257
1258  return false;
1259}
1260
1261/// ParseCXXSimpleTypeSpecifier - [C++ 7.1.5.2] Simple type specifiers.
1262/// This should only be called when the current token is known to be part of
1263/// simple-type-specifier.
1264///
1265///       simple-type-specifier:
1266///         '::'[opt] nested-name-specifier[opt] type-name
1267///         '::'[opt] nested-name-specifier 'template' simple-template-id [TODO]
1268///         char
1269///         wchar_t
1270///         bool
1271///         short
1272///         int
1273///         long
1274///         signed
1275///         unsigned
1276///         float
1277///         double
1278///         void
1279/// [GNU]   typeof-specifier
1280/// [C++0x] auto               [TODO]
1281///
1282///       type-name:
1283///         class-name
1284///         enum-name
1285///         typedef-name
1286///
1287void Parser::ParseCXXSimpleTypeSpecifier(DeclSpec &DS) {
1288  DS.SetRangeStart(Tok.getLocation());
1289  const char *PrevSpec;
1290  unsigned DiagID;
1291  SourceLocation Loc = Tok.getLocation();
1292
1293  switch (Tok.getKind()) {
1294  case tok::identifier:   // foo::bar
1295  case tok::coloncolon:   // ::foo::bar
1296    llvm_unreachable("Annotation token should already be formed!");
1297  default:
1298    llvm_unreachable("Not a simple-type-specifier token!");
1299
1300  // type-name
1301  case tok::annot_typename: {
1302    if (getTypeAnnotation(Tok))
1303      DS.SetTypeSpecType(DeclSpec::TST_typename, Loc, PrevSpec, DiagID,
1304                         getTypeAnnotation(Tok));
1305    else
1306      DS.SetTypeSpecError();
1307
1308    DS.SetRangeEnd(Tok.getAnnotationEndLoc());
1309    ConsumeToken();
1310
1311    // Objective-C supports syntax of the form 'id<proto1,proto2>' where 'id'
1312    // is a specific typedef and 'itf<proto1,proto2>' where 'itf' is an
1313    // Objective-C interface.  If we don't have Objective-C or a '<', this is
1314    // just a normal reference to a typedef name.
1315    if (Tok.is(tok::less) && getLang().ObjC1)
1316      ParseObjCProtocolQualifiers(DS);
1317
1318    DS.Finish(Diags, PP);
1319    return;
1320  }
1321
1322  // builtin types
1323  case tok::kw_short:
1324    DS.SetTypeSpecWidth(DeclSpec::TSW_short, Loc, PrevSpec, DiagID);
1325    break;
1326  case tok::kw_long:
1327    DS.SetTypeSpecWidth(DeclSpec::TSW_long, Loc, PrevSpec, DiagID);
1328    break;
1329  case tok::kw___int64:
1330    DS.SetTypeSpecWidth(DeclSpec::TSW_longlong, Loc, PrevSpec, DiagID);
1331    break;
1332  case tok::kw_signed:
1333    DS.SetTypeSpecSign(DeclSpec::TSS_signed, Loc, PrevSpec, DiagID);
1334    break;
1335  case tok::kw_unsigned:
1336    DS.SetTypeSpecSign(DeclSpec::TSS_unsigned, Loc, PrevSpec, DiagID);
1337    break;
1338  case tok::kw_void:
1339    DS.SetTypeSpecType(DeclSpec::TST_void, Loc, PrevSpec, DiagID);
1340    break;
1341  case tok::kw_char:
1342    DS.SetTypeSpecType(DeclSpec::TST_char, Loc, PrevSpec, DiagID);
1343    break;
1344  case tok::kw_int:
1345    DS.SetTypeSpecType(DeclSpec::TST_int, Loc, PrevSpec, DiagID);
1346    break;
1347  case tok::kw_half:
1348    DS.SetTypeSpecType(DeclSpec::TST_half, Loc, PrevSpec, DiagID);
1349    break;
1350  case tok::kw_float:
1351    DS.SetTypeSpecType(DeclSpec::TST_float, Loc, PrevSpec, DiagID);
1352    break;
1353  case tok::kw_double:
1354    DS.SetTypeSpecType(DeclSpec::TST_double, Loc, PrevSpec, DiagID);
1355    break;
1356  case tok::kw_wchar_t:
1357    DS.SetTypeSpecType(DeclSpec::TST_wchar, Loc, PrevSpec, DiagID);
1358    break;
1359  case tok::kw_char16_t:
1360    DS.SetTypeSpecType(DeclSpec::TST_char16, Loc, PrevSpec, DiagID);
1361    break;
1362  case tok::kw_char32_t:
1363    DS.SetTypeSpecType(DeclSpec::TST_char32, Loc, PrevSpec, DiagID);
1364    break;
1365  case tok::kw_bool:
1366    DS.SetTypeSpecType(DeclSpec::TST_bool, Loc, PrevSpec, DiagID);
1367    break;
1368
1369    // FIXME: C++0x decltype support.
1370  // GNU typeof support.
1371  case tok::kw_typeof:
1372    ParseTypeofSpecifier(DS);
1373    DS.Finish(Diags, PP);
1374    return;
1375  }
1376  if (Tok.is(tok::annot_typename))
1377    DS.SetRangeEnd(Tok.getAnnotationEndLoc());
1378  else
1379    DS.SetRangeEnd(Tok.getLocation());
1380  ConsumeToken();
1381  DS.Finish(Diags, PP);
1382}
1383
1384/// ParseCXXTypeSpecifierSeq - Parse a C++ type-specifier-seq (C++
1385/// [dcl.name]), which is a non-empty sequence of type-specifiers,
1386/// e.g., "const short int". Note that the DeclSpec is *not* finished
1387/// by parsing the type-specifier-seq, because these sequences are
1388/// typically followed by some form of declarator. Returns true and
1389/// emits diagnostics if this is not a type-specifier-seq, false
1390/// otherwise.
1391///
1392///   type-specifier-seq: [C++ 8.1]
1393///     type-specifier type-specifier-seq[opt]
1394///
1395bool Parser::ParseCXXTypeSpecifierSeq(DeclSpec &DS) {
1396  DS.SetRangeStart(Tok.getLocation());
1397  const char *PrevSpec = 0;
1398  unsigned DiagID;
1399  bool isInvalid = 0;
1400
1401  // Parse one or more of the type specifiers.
1402  if (!ParseOptionalTypeSpecifier(DS, isInvalid, PrevSpec, DiagID,
1403      ParsedTemplateInfo(), /*SuppressDeclarations*/true)) {
1404    Diag(Tok, diag::err_expected_type);
1405    return true;
1406  }
1407
1408  while (ParseOptionalTypeSpecifier(DS, isInvalid, PrevSpec, DiagID,
1409         ParsedTemplateInfo(), /*SuppressDeclarations*/true))
1410  {}
1411
1412  DS.Finish(Diags, PP);
1413  return false;
1414}
1415
1416/// \brief Finish parsing a C++ unqualified-id that is a template-id of
1417/// some form.
1418///
1419/// This routine is invoked when a '<' is encountered after an identifier or
1420/// operator-function-id is parsed by \c ParseUnqualifiedId() to determine
1421/// whether the unqualified-id is actually a template-id. This routine will
1422/// then parse the template arguments and form the appropriate template-id to
1423/// return to the caller.
1424///
1425/// \param SS the nested-name-specifier that precedes this template-id, if
1426/// we're actually parsing a qualified-id.
1427///
1428/// \param Name for constructor and destructor names, this is the actual
1429/// identifier that may be a template-name.
1430///
1431/// \param NameLoc the location of the class-name in a constructor or
1432/// destructor.
1433///
1434/// \param EnteringContext whether we're entering the scope of the
1435/// nested-name-specifier.
1436///
1437/// \param ObjectType if this unqualified-id occurs within a member access
1438/// expression, the type of the base object whose member is being accessed.
1439///
1440/// \param Id as input, describes the template-name or operator-function-id
1441/// that precedes the '<'. If template arguments were parsed successfully,
1442/// will be updated with the template-id.
1443///
1444/// \param AssumeTemplateId When true, this routine will assume that the name
1445/// refers to a template without performing name lookup to verify.
1446///
1447/// \returns true if a parse error occurred, false otherwise.
1448bool Parser::ParseUnqualifiedIdTemplateId(CXXScopeSpec &SS,
1449                                          IdentifierInfo *Name,
1450                                          SourceLocation NameLoc,
1451                                          bool EnteringContext,
1452                                          ParsedType ObjectType,
1453                                          UnqualifiedId &Id,
1454                                          bool AssumeTemplateId,
1455                                          SourceLocation TemplateKWLoc) {
1456  assert((AssumeTemplateId || Tok.is(tok::less)) &&
1457         "Expected '<' to finish parsing a template-id");
1458
1459  TemplateTy Template;
1460  TemplateNameKind TNK = TNK_Non_template;
1461  switch (Id.getKind()) {
1462  case UnqualifiedId::IK_Identifier:
1463  case UnqualifiedId::IK_OperatorFunctionId:
1464  case UnqualifiedId::IK_LiteralOperatorId:
1465    if (AssumeTemplateId) {
1466      TNK = Actions.ActOnDependentTemplateName(getCurScope(), TemplateKWLoc, SS,
1467                                               Id, ObjectType, EnteringContext,
1468                                               Template);
1469      if (TNK == TNK_Non_template)
1470        return true;
1471    } else {
1472      bool MemberOfUnknownSpecialization;
1473      TNK = Actions.isTemplateName(getCurScope(), SS,
1474                                   TemplateKWLoc.isValid(), Id,
1475                                   ObjectType, EnteringContext, Template,
1476                                   MemberOfUnknownSpecialization);
1477
1478      if (TNK == TNK_Non_template && MemberOfUnknownSpecialization &&
1479          ObjectType && IsTemplateArgumentList()) {
1480        // We have something like t->getAs<T>(), where getAs is a
1481        // member of an unknown specialization. However, this will only
1482        // parse correctly as a template, so suggest the keyword 'template'
1483        // before 'getAs' and treat this as a dependent template name.
1484        std::string Name;
1485        if (Id.getKind() == UnqualifiedId::IK_Identifier)
1486          Name = Id.Identifier->getName();
1487        else {
1488          Name = "operator ";
1489          if (Id.getKind() == UnqualifiedId::IK_OperatorFunctionId)
1490            Name += getOperatorSpelling(Id.OperatorFunctionId.Operator);
1491          else
1492            Name += Id.Identifier->getName();
1493        }
1494        Diag(Id.StartLocation, diag::err_missing_dependent_template_keyword)
1495          << Name
1496          << FixItHint::CreateInsertion(Id.StartLocation, "template ");
1497        TNK = Actions.ActOnDependentTemplateName(getCurScope(), TemplateKWLoc,
1498                                                 SS, Id, ObjectType,
1499                                                 EnteringContext, Template);
1500        if (TNK == TNK_Non_template)
1501          return true;
1502      }
1503    }
1504    break;
1505
1506  case UnqualifiedId::IK_ConstructorName: {
1507    UnqualifiedId TemplateName;
1508    bool MemberOfUnknownSpecialization;
1509    TemplateName.setIdentifier(Name, NameLoc);
1510    TNK = Actions.isTemplateName(getCurScope(), SS, TemplateKWLoc.isValid(),
1511                                 TemplateName, ObjectType,
1512                                 EnteringContext, Template,
1513                                 MemberOfUnknownSpecialization);
1514    break;
1515  }
1516
1517  case UnqualifiedId::IK_DestructorName: {
1518    UnqualifiedId TemplateName;
1519    bool MemberOfUnknownSpecialization;
1520    TemplateName.setIdentifier(Name, NameLoc);
1521    if (ObjectType) {
1522      TNK = Actions.ActOnDependentTemplateName(getCurScope(), TemplateKWLoc, SS,
1523                                               TemplateName, ObjectType,
1524                                               EnteringContext, Template);
1525      if (TNK == TNK_Non_template)
1526        return true;
1527    } else {
1528      TNK = Actions.isTemplateName(getCurScope(), SS, TemplateKWLoc.isValid(),
1529                                   TemplateName, ObjectType,
1530                                   EnteringContext, Template,
1531                                   MemberOfUnknownSpecialization);
1532
1533      if (TNK == TNK_Non_template && !Id.DestructorName.get()) {
1534        Diag(NameLoc, diag::err_destructor_template_id)
1535          << Name << SS.getRange();
1536        return true;
1537      }
1538    }
1539    break;
1540  }
1541
1542  default:
1543    return false;
1544  }
1545
1546  if (TNK == TNK_Non_template)
1547    return false;
1548
1549  // Parse the enclosed template argument list.
1550  SourceLocation LAngleLoc, RAngleLoc;
1551  TemplateArgList TemplateArgs;
1552  if (Tok.is(tok::less) &&
1553      ParseTemplateIdAfterTemplateName(Template, Id.StartLocation,
1554                                       SS, true, LAngleLoc,
1555                                       TemplateArgs,
1556                                       RAngleLoc))
1557    return true;
1558
1559  if (Id.getKind() == UnqualifiedId::IK_Identifier ||
1560      Id.getKind() == UnqualifiedId::IK_OperatorFunctionId ||
1561      Id.getKind() == UnqualifiedId::IK_LiteralOperatorId) {
1562    // Form a parsed representation of the template-id to be stored in the
1563    // UnqualifiedId.
1564    TemplateIdAnnotation *TemplateId
1565      = TemplateIdAnnotation::Allocate(TemplateArgs.size());
1566
1567    if (Id.getKind() == UnqualifiedId::IK_Identifier) {
1568      TemplateId->Name = Id.Identifier;
1569      TemplateId->Operator = OO_None;
1570      TemplateId->TemplateNameLoc = Id.StartLocation;
1571    } else {
1572      TemplateId->Name = 0;
1573      TemplateId->Operator = Id.OperatorFunctionId.Operator;
1574      TemplateId->TemplateNameLoc = Id.StartLocation;
1575    }
1576
1577    TemplateId->SS = SS;
1578    TemplateId->Template = Template;
1579    TemplateId->Kind = TNK;
1580    TemplateId->LAngleLoc = LAngleLoc;
1581    TemplateId->RAngleLoc = RAngleLoc;
1582    ParsedTemplateArgument *Args = TemplateId->getTemplateArgs();
1583    for (unsigned Arg = 0, ArgEnd = TemplateArgs.size();
1584         Arg != ArgEnd; ++Arg)
1585      Args[Arg] = TemplateArgs[Arg];
1586
1587    Id.setTemplateId(TemplateId);
1588    return false;
1589  }
1590
1591  // Bundle the template arguments together.
1592  ASTTemplateArgsPtr TemplateArgsPtr(Actions, TemplateArgs.data(),
1593                                     TemplateArgs.size());
1594
1595  // Constructor and destructor names.
1596  TypeResult Type
1597    = Actions.ActOnTemplateIdType(SS, Template, NameLoc,
1598                                  LAngleLoc, TemplateArgsPtr,
1599                                  RAngleLoc);
1600  if (Type.isInvalid())
1601    return true;
1602
1603  if (Id.getKind() == UnqualifiedId::IK_ConstructorName)
1604    Id.setConstructorName(Type.get(), NameLoc, RAngleLoc);
1605  else
1606    Id.setDestructorName(Id.StartLocation, Type.get(), RAngleLoc);
1607
1608  return false;
1609}
1610
1611/// \brief Parse an operator-function-id or conversion-function-id as part
1612/// of a C++ unqualified-id.
1613///
1614/// This routine is responsible only for parsing the operator-function-id or
1615/// conversion-function-id; it does not handle template arguments in any way.
1616///
1617/// \code
1618///       operator-function-id: [C++ 13.5]
1619///         'operator' operator
1620///
1621///       operator: one of
1622///            new   delete  new[]   delete[]
1623///            +     -    *  /    %  ^    &   |   ~
1624///            !     =    <  >    += -=   *=  /=  %=
1625///            ^=    &=   |= <<   >> >>= <<=  ==  !=
1626///            <=    >=   && ||   ++ --   ,   ->* ->
1627///            ()    []
1628///
1629///       conversion-function-id: [C++ 12.3.2]
1630///         operator conversion-type-id
1631///
1632///       conversion-type-id:
1633///         type-specifier-seq conversion-declarator[opt]
1634///
1635///       conversion-declarator:
1636///         ptr-operator conversion-declarator[opt]
1637/// \endcode
1638///
1639/// \param The nested-name-specifier that preceded this unqualified-id. If
1640/// non-empty, then we are parsing the unqualified-id of a qualified-id.
1641///
1642/// \param EnteringContext whether we are entering the scope of the
1643/// nested-name-specifier.
1644///
1645/// \param ObjectType if this unqualified-id occurs within a member access
1646/// expression, the type of the base object whose member is being accessed.
1647///
1648/// \param Result on a successful parse, contains the parsed unqualified-id.
1649///
1650/// \returns true if parsing fails, false otherwise.
1651bool Parser::ParseUnqualifiedIdOperator(CXXScopeSpec &SS, bool EnteringContext,
1652                                        ParsedType ObjectType,
1653                                        UnqualifiedId &Result) {
1654  assert(Tok.is(tok::kw_operator) && "Expected 'operator' keyword");
1655
1656  // Consume the 'operator' keyword.
1657  SourceLocation KeywordLoc = ConsumeToken();
1658
1659  // Determine what kind of operator name we have.
1660  unsigned SymbolIdx = 0;
1661  SourceLocation SymbolLocations[3];
1662  OverloadedOperatorKind Op = OO_None;
1663  switch (Tok.getKind()) {
1664    case tok::kw_new:
1665    case tok::kw_delete: {
1666      bool isNew = Tok.getKind() == tok::kw_new;
1667      // Consume the 'new' or 'delete'.
1668      SymbolLocations[SymbolIdx++] = ConsumeToken();
1669      if (Tok.is(tok::l_square)) {
1670        // Consume the '[' and ']'.
1671        BalancedDelimiterTracker T(*this, tok::l_square);
1672        T.consumeOpen();
1673        T.consumeClose();
1674        if (T.getCloseLocation().isInvalid())
1675          return true;
1676
1677        SymbolLocations[SymbolIdx++] = T.getOpenLocation();
1678        SymbolLocations[SymbolIdx++] = T.getCloseLocation();
1679        Op = isNew? OO_Array_New : OO_Array_Delete;
1680      } else {
1681        Op = isNew? OO_New : OO_Delete;
1682      }
1683      break;
1684    }
1685
1686#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
1687    case tok::Token:                                                     \
1688      SymbolLocations[SymbolIdx++] = ConsumeToken();                     \
1689      Op = OO_##Name;                                                    \
1690      break;
1691#define OVERLOADED_OPERATOR_MULTI(Name,Spelling,Unary,Binary,MemberOnly)
1692#include "clang/Basic/OperatorKinds.def"
1693
1694    case tok::l_paren: {
1695      // Consume the '(' and ')'.
1696      BalancedDelimiterTracker T(*this, tok::l_paren);
1697      T.consumeOpen();
1698      T.consumeClose();
1699      if (T.getCloseLocation().isInvalid())
1700        return true;
1701
1702      SymbolLocations[SymbolIdx++] = T.getOpenLocation();
1703      SymbolLocations[SymbolIdx++] = T.getCloseLocation();
1704      Op = OO_Call;
1705      break;
1706    }
1707
1708    case tok::l_square: {
1709      // Consume the '[' and ']'.
1710      BalancedDelimiterTracker T(*this, tok::l_square);
1711      T.consumeOpen();
1712      T.consumeClose();
1713      if (T.getCloseLocation().isInvalid())
1714        return true;
1715
1716      SymbolLocations[SymbolIdx++] = T.getOpenLocation();
1717      SymbolLocations[SymbolIdx++] = T.getCloseLocation();
1718      Op = OO_Subscript;
1719      break;
1720    }
1721
1722    case tok::code_completion: {
1723      // Code completion for the operator name.
1724      Actions.CodeCompleteOperatorName(getCurScope());
1725      cutOffParsing();
1726      // Don't try to parse any further.
1727      return true;
1728    }
1729
1730    default:
1731      break;
1732  }
1733
1734  if (Op != OO_None) {
1735    // We have parsed an operator-function-id.
1736    Result.setOperatorFunctionId(KeywordLoc, Op, SymbolLocations);
1737    return false;
1738  }
1739
1740  // Parse a literal-operator-id.
1741  //
1742  //   literal-operator-id: [C++0x 13.5.8]
1743  //     operator "" identifier
1744
1745  if (getLang().CPlusPlus0x && Tok.is(tok::string_literal)) {
1746    if (Tok.getLength() != 2)
1747      Diag(Tok.getLocation(), diag::err_operator_string_not_empty);
1748    ConsumeStringToken();
1749
1750    if (Tok.isNot(tok::identifier)) {
1751      Diag(Tok.getLocation(), diag::err_expected_ident);
1752      return true;
1753    }
1754
1755    IdentifierInfo *II = Tok.getIdentifierInfo();
1756    Result.setLiteralOperatorId(II, KeywordLoc, ConsumeToken());
1757    return false;
1758  }
1759
1760  // Parse a conversion-function-id.
1761  //
1762  //   conversion-function-id: [C++ 12.3.2]
1763  //     operator conversion-type-id
1764  //
1765  //   conversion-type-id:
1766  //     type-specifier-seq conversion-declarator[opt]
1767  //
1768  //   conversion-declarator:
1769  //     ptr-operator conversion-declarator[opt]
1770
1771  // Parse the type-specifier-seq.
1772  DeclSpec DS(AttrFactory);
1773  if (ParseCXXTypeSpecifierSeq(DS)) // FIXME: ObjectType?
1774    return true;
1775
1776  // Parse the conversion-declarator, which is merely a sequence of
1777  // ptr-operators.
1778  Declarator D(DS, Declarator::TypeNameContext);
1779  ParseDeclaratorInternal(D, /*DirectDeclParser=*/0);
1780
1781  // Finish up the type.
1782  TypeResult Ty = Actions.ActOnTypeName(getCurScope(), D);
1783  if (Ty.isInvalid())
1784    return true;
1785
1786  // Note that this is a conversion-function-id.
1787  Result.setConversionFunctionId(KeywordLoc, Ty.get(),
1788                                 D.getSourceRange().getEnd());
1789  return false;
1790}
1791
1792/// \brief Parse a C++ unqualified-id (or a C identifier), which describes the
1793/// name of an entity.
1794///
1795/// \code
1796///       unqualified-id: [C++ expr.prim.general]
1797///         identifier
1798///         operator-function-id
1799///         conversion-function-id
1800/// [C++0x] literal-operator-id [TODO]
1801///         ~ class-name
1802///         template-id
1803///
1804/// \endcode
1805///
1806/// \param The nested-name-specifier that preceded this unqualified-id. If
1807/// non-empty, then we are parsing the unqualified-id of a qualified-id.
1808///
1809/// \param EnteringContext whether we are entering the scope of the
1810/// nested-name-specifier.
1811///
1812/// \param AllowDestructorName whether we allow parsing of a destructor name.
1813///
1814/// \param AllowConstructorName whether we allow parsing a constructor name.
1815///
1816/// \param ObjectType if this unqualified-id occurs within a member access
1817/// expression, the type of the base object whose member is being accessed.
1818///
1819/// \param Result on a successful parse, contains the parsed unqualified-id.
1820///
1821/// \returns true if parsing fails, false otherwise.
1822bool Parser::ParseUnqualifiedId(CXXScopeSpec &SS, bool EnteringContext,
1823                                bool AllowDestructorName,
1824                                bool AllowConstructorName,
1825                                ParsedType ObjectType,
1826                                UnqualifiedId &Result) {
1827
1828  // Handle 'A::template B'. This is for template-ids which have not
1829  // already been annotated by ParseOptionalCXXScopeSpecifier().
1830  bool TemplateSpecified = false;
1831  SourceLocation TemplateKWLoc;
1832  if (getLang().CPlusPlus && Tok.is(tok::kw_template) &&
1833      (ObjectType || SS.isSet())) {
1834    TemplateSpecified = true;
1835    TemplateKWLoc = ConsumeToken();
1836  }
1837
1838  // unqualified-id:
1839  //   identifier
1840  //   template-id (when it hasn't already been annotated)
1841  if (Tok.is(tok::identifier)) {
1842    // Consume the identifier.
1843    IdentifierInfo *Id = Tok.getIdentifierInfo();
1844    SourceLocation IdLoc = ConsumeToken();
1845
1846    if (!getLang().CPlusPlus) {
1847      // If we're not in C++, only identifiers matter. Record the
1848      // identifier and return.
1849      Result.setIdentifier(Id, IdLoc);
1850      return false;
1851    }
1852
1853    if (AllowConstructorName &&
1854        Actions.isCurrentClassName(*Id, getCurScope(), &SS)) {
1855      // We have parsed a constructor name.
1856      Result.setConstructorName(Actions.getTypeName(*Id, IdLoc, getCurScope(),
1857                                                    &SS, false, false,
1858                                                    ParsedType(),
1859                                            /*NonTrivialTypeSourceInfo=*/true),
1860                                IdLoc, IdLoc);
1861    } else {
1862      // We have parsed an identifier.
1863      Result.setIdentifier(Id, IdLoc);
1864    }
1865
1866    // If the next token is a '<', we may have a template.
1867    if (TemplateSpecified || Tok.is(tok::less))
1868      return ParseUnqualifiedIdTemplateId(SS, Id, IdLoc, EnteringContext,
1869                                          ObjectType, Result,
1870                                          TemplateSpecified, TemplateKWLoc);
1871
1872    return false;
1873  }
1874
1875  // unqualified-id:
1876  //   template-id (already parsed and annotated)
1877  if (Tok.is(tok::annot_template_id)) {
1878    TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
1879
1880    // If the template-name names the current class, then this is a constructor
1881    if (AllowConstructorName && TemplateId->Name &&
1882        Actions.isCurrentClassName(*TemplateId->Name, getCurScope(), &SS)) {
1883      if (SS.isSet()) {
1884        // C++ [class.qual]p2 specifies that a qualified template-name
1885        // is taken as the constructor name where a constructor can be
1886        // declared. Thus, the template arguments are extraneous, so
1887        // complain about them and remove them entirely.
1888        Diag(TemplateId->TemplateNameLoc,
1889             diag::err_out_of_line_constructor_template_id)
1890          << TemplateId->Name
1891          << FixItHint::CreateRemoval(
1892                    SourceRange(TemplateId->LAngleLoc, TemplateId->RAngleLoc));
1893        Result.setConstructorName(Actions.getTypeName(*TemplateId->Name,
1894                                                  TemplateId->TemplateNameLoc,
1895                                                      getCurScope(),
1896                                                      &SS, false, false,
1897                                                      ParsedType(),
1898                                            /*NontrivialTypeSourceInfo=*/true),
1899                                  TemplateId->TemplateNameLoc,
1900                                  TemplateId->RAngleLoc);
1901        ConsumeToken();
1902        return false;
1903      }
1904
1905      Result.setConstructorTemplateId(TemplateId);
1906      ConsumeToken();
1907      return false;
1908    }
1909
1910    // We have already parsed a template-id; consume the annotation token as
1911    // our unqualified-id.
1912    Result.setTemplateId(TemplateId);
1913    ConsumeToken();
1914    return false;
1915  }
1916
1917  // unqualified-id:
1918  //   operator-function-id
1919  //   conversion-function-id
1920  if (Tok.is(tok::kw_operator)) {
1921    if (ParseUnqualifiedIdOperator(SS, EnteringContext, ObjectType, Result))
1922      return true;
1923
1924    // If we have an operator-function-id or a literal-operator-id and the next
1925    // token is a '<', we may have a
1926    //
1927    //   template-id:
1928    //     operator-function-id < template-argument-list[opt] >
1929    if ((Result.getKind() == UnqualifiedId::IK_OperatorFunctionId ||
1930         Result.getKind() == UnqualifiedId::IK_LiteralOperatorId) &&
1931        (TemplateSpecified || Tok.is(tok::less)))
1932      return ParseUnqualifiedIdTemplateId(SS, 0, SourceLocation(),
1933                                          EnteringContext, ObjectType,
1934                                          Result,
1935                                          TemplateSpecified, TemplateKWLoc);
1936
1937    return false;
1938  }
1939
1940  if (getLang().CPlusPlus &&
1941      (AllowDestructorName || SS.isSet()) && Tok.is(tok::tilde)) {
1942    // C++ [expr.unary.op]p10:
1943    //   There is an ambiguity in the unary-expression ~X(), where X is a
1944    //   class-name. The ambiguity is resolved in favor of treating ~ as a
1945    //    unary complement rather than treating ~X as referring to a destructor.
1946
1947    // Parse the '~'.
1948    SourceLocation TildeLoc = ConsumeToken();
1949
1950    // Parse the class-name.
1951    if (Tok.isNot(tok::identifier)) {
1952      Diag(Tok, diag::err_destructor_tilde_identifier);
1953      return true;
1954    }
1955
1956    // Parse the class-name (or template-name in a simple-template-id).
1957    IdentifierInfo *ClassName = Tok.getIdentifierInfo();
1958    SourceLocation ClassNameLoc = ConsumeToken();
1959
1960    if (TemplateSpecified || Tok.is(tok::less)) {
1961      Result.setDestructorName(TildeLoc, ParsedType(), ClassNameLoc);
1962      return ParseUnqualifiedIdTemplateId(SS, ClassName, ClassNameLoc,
1963                                          EnteringContext, ObjectType, Result,
1964                                          TemplateSpecified, TemplateKWLoc);
1965    }
1966
1967    // Note that this is a destructor name.
1968    ParsedType Ty = Actions.getDestructorName(TildeLoc, *ClassName,
1969                                              ClassNameLoc, getCurScope(),
1970                                              SS, ObjectType,
1971                                              EnteringContext);
1972    if (!Ty)
1973      return true;
1974
1975    Result.setDestructorName(TildeLoc, Ty, ClassNameLoc);
1976    return false;
1977  }
1978
1979  Diag(Tok, diag::err_expected_unqualified_id)
1980    << getLang().CPlusPlus;
1981  return true;
1982}
1983
1984/// ParseCXXNewExpression - Parse a C++ new-expression. New is used to allocate
1985/// memory in a typesafe manner and call constructors.
1986///
1987/// This method is called to parse the new expression after the optional :: has
1988/// been already parsed.  If the :: was present, "UseGlobal" is true and "Start"
1989/// is its location.  Otherwise, "Start" is the location of the 'new' token.
1990///
1991///        new-expression:
1992///                   '::'[opt] 'new' new-placement[opt] new-type-id
1993///                                     new-initializer[opt]
1994///                   '::'[opt] 'new' new-placement[opt] '(' type-id ')'
1995///                                     new-initializer[opt]
1996///
1997///        new-placement:
1998///                   '(' expression-list ')'
1999///
2000///        new-type-id:
2001///                   type-specifier-seq new-declarator[opt]
2002/// [GNU]             attributes type-specifier-seq new-declarator[opt]
2003///
2004///        new-declarator:
2005///                   ptr-operator new-declarator[opt]
2006///                   direct-new-declarator
2007///
2008///        new-initializer:
2009///                   '(' expression-list[opt] ')'
2010/// [C++0x]           braced-init-list
2011///
2012ExprResult
2013Parser::ParseCXXNewExpression(bool UseGlobal, SourceLocation Start) {
2014  assert(Tok.is(tok::kw_new) && "expected 'new' token");
2015  ConsumeToken();   // Consume 'new'
2016
2017  // A '(' now can be a new-placement or the '(' wrapping the type-id in the
2018  // second form of new-expression. It can't be a new-type-id.
2019
2020  ExprVector PlacementArgs(Actions);
2021  SourceLocation PlacementLParen, PlacementRParen;
2022
2023  SourceRange TypeIdParens;
2024  DeclSpec DS(AttrFactory);
2025  Declarator DeclaratorInfo(DS, Declarator::CXXNewContext);
2026  if (Tok.is(tok::l_paren)) {
2027    // If it turns out to be a placement, we change the type location.
2028    BalancedDelimiterTracker T(*this, tok::l_paren);
2029    T.consumeOpen();
2030    PlacementLParen = T.getOpenLocation();
2031    if (ParseExpressionListOrTypeId(PlacementArgs, DeclaratorInfo)) {
2032      SkipUntil(tok::semi, /*StopAtSemi=*/true, /*DontConsume=*/true);
2033      return ExprError();
2034    }
2035
2036    T.consumeClose();
2037    PlacementRParen = T.getCloseLocation();
2038    if (PlacementRParen.isInvalid()) {
2039      SkipUntil(tok::semi, /*StopAtSemi=*/true, /*DontConsume=*/true);
2040      return ExprError();
2041    }
2042
2043    if (PlacementArgs.empty()) {
2044      // Reset the placement locations. There was no placement.
2045      TypeIdParens = T.getRange();
2046      PlacementLParen = PlacementRParen = SourceLocation();
2047    } else {
2048      // We still need the type.
2049      if (Tok.is(tok::l_paren)) {
2050        BalancedDelimiterTracker T(*this, tok::l_paren);
2051        T.consumeOpen();
2052        MaybeParseGNUAttributes(DeclaratorInfo);
2053        ParseSpecifierQualifierList(DS);
2054        DeclaratorInfo.SetSourceRange(DS.getSourceRange());
2055        ParseDeclarator(DeclaratorInfo);
2056        T.consumeClose();
2057        TypeIdParens = T.getRange();
2058      } else {
2059        MaybeParseGNUAttributes(DeclaratorInfo);
2060        if (ParseCXXTypeSpecifierSeq(DS))
2061          DeclaratorInfo.setInvalidType(true);
2062        else {
2063          DeclaratorInfo.SetSourceRange(DS.getSourceRange());
2064          ParseDeclaratorInternal(DeclaratorInfo,
2065                                  &Parser::ParseDirectNewDeclarator);
2066        }
2067      }
2068    }
2069  } else {
2070    // A new-type-id is a simplified type-id, where essentially the
2071    // direct-declarator is replaced by a direct-new-declarator.
2072    MaybeParseGNUAttributes(DeclaratorInfo);
2073    if (ParseCXXTypeSpecifierSeq(DS))
2074      DeclaratorInfo.setInvalidType(true);
2075    else {
2076      DeclaratorInfo.SetSourceRange(DS.getSourceRange());
2077      ParseDeclaratorInternal(DeclaratorInfo,
2078                              &Parser::ParseDirectNewDeclarator);
2079    }
2080  }
2081  if (DeclaratorInfo.isInvalidType()) {
2082    SkipUntil(tok::semi, /*StopAtSemi=*/true, /*DontConsume=*/true);
2083    return ExprError();
2084  }
2085
2086  ExprVector ConstructorArgs(Actions);
2087  SourceLocation ConstructorLParen, ConstructorRParen;
2088
2089  if (Tok.is(tok::l_paren)) {
2090    BalancedDelimiterTracker T(*this, tok::l_paren);
2091    T.consumeOpen();
2092    ConstructorLParen = T.getOpenLocation();
2093    if (Tok.isNot(tok::r_paren)) {
2094      CommaLocsTy CommaLocs;
2095      if (ParseExpressionList(ConstructorArgs, CommaLocs)) {
2096        SkipUntil(tok::semi, /*StopAtSemi=*/true, /*DontConsume=*/true);
2097        return ExprError();
2098      }
2099    }
2100    T.consumeClose();
2101    ConstructorRParen = T.getCloseLocation();
2102    if (ConstructorRParen.isInvalid()) {
2103      SkipUntil(tok::semi, /*StopAtSemi=*/true, /*DontConsume=*/true);
2104      return ExprError();
2105    }
2106  } else if (Tok.is(tok::l_brace) && getLang().CPlusPlus0x) {
2107    // FIXME: Have to communicate the init-list to ActOnCXXNew.
2108    ParseBraceInitializer();
2109  }
2110
2111  return Actions.ActOnCXXNew(Start, UseGlobal, PlacementLParen,
2112                             move_arg(PlacementArgs), PlacementRParen,
2113                             TypeIdParens, DeclaratorInfo, ConstructorLParen,
2114                             move_arg(ConstructorArgs), ConstructorRParen);
2115}
2116
2117/// ParseDirectNewDeclarator - Parses a direct-new-declarator. Intended to be
2118/// passed to ParseDeclaratorInternal.
2119///
2120///        direct-new-declarator:
2121///                   '[' expression ']'
2122///                   direct-new-declarator '[' constant-expression ']'
2123///
2124void Parser::ParseDirectNewDeclarator(Declarator &D) {
2125  // Parse the array dimensions.
2126  bool first = true;
2127  while (Tok.is(tok::l_square)) {
2128    BalancedDelimiterTracker T(*this, tok::l_square);
2129    T.consumeOpen();
2130
2131    ExprResult Size(first ? ParseExpression()
2132                                : ParseConstantExpression());
2133    if (Size.isInvalid()) {
2134      // Recover
2135      SkipUntil(tok::r_square);
2136      return;
2137    }
2138    first = false;
2139
2140    T.consumeClose();
2141
2142    ParsedAttributes attrs(AttrFactory);
2143    D.AddTypeInfo(DeclaratorChunk::getArray(0,
2144                                            /*static=*/false, /*star=*/false,
2145                                            Size.release(),
2146                                            T.getOpenLocation(),
2147                                            T.getCloseLocation()),
2148                  attrs, T.getCloseLocation());
2149
2150    if (T.getCloseLocation().isInvalid())
2151      return;
2152  }
2153}
2154
2155/// ParseExpressionListOrTypeId - Parse either an expression-list or a type-id.
2156/// This ambiguity appears in the syntax of the C++ new operator.
2157///
2158///        new-expression:
2159///                   '::'[opt] 'new' new-placement[opt] '(' type-id ')'
2160///                                     new-initializer[opt]
2161///
2162///        new-placement:
2163///                   '(' expression-list ')'
2164///
2165bool Parser::ParseExpressionListOrTypeId(
2166                                   SmallVectorImpl<Expr*> &PlacementArgs,
2167                                         Declarator &D) {
2168  // The '(' was already consumed.
2169  if (isTypeIdInParens()) {
2170    ParseSpecifierQualifierList(D.getMutableDeclSpec());
2171    D.SetSourceRange(D.getDeclSpec().getSourceRange());
2172    ParseDeclarator(D);
2173    return D.isInvalidType();
2174  }
2175
2176  // It's not a type, it has to be an expression list.
2177  // Discard the comma locations - ActOnCXXNew has enough parameters.
2178  CommaLocsTy CommaLocs;
2179  return ParseExpressionList(PlacementArgs, CommaLocs);
2180}
2181
2182/// ParseCXXDeleteExpression - Parse a C++ delete-expression. Delete is used
2183/// to free memory allocated by new.
2184///
2185/// This method is called to parse the 'delete' expression after the optional
2186/// '::' has been already parsed.  If the '::' was present, "UseGlobal" is true
2187/// and "Start" is its location.  Otherwise, "Start" is the location of the
2188/// 'delete' token.
2189///
2190///        delete-expression:
2191///                   '::'[opt] 'delete' cast-expression
2192///                   '::'[opt] 'delete' '[' ']' cast-expression
2193ExprResult
2194Parser::ParseCXXDeleteExpression(bool UseGlobal, SourceLocation Start) {
2195  assert(Tok.is(tok::kw_delete) && "Expected 'delete' keyword");
2196  ConsumeToken(); // Consume 'delete'
2197
2198  // Array delete?
2199  bool ArrayDelete = false;
2200  if (Tok.is(tok::l_square)) {
2201    ArrayDelete = true;
2202    BalancedDelimiterTracker T(*this, tok::l_square);
2203
2204    T.consumeOpen();
2205    T.consumeClose();
2206    if (T.getCloseLocation().isInvalid())
2207      return ExprError();
2208  }
2209
2210  ExprResult Operand(ParseCastExpression(false));
2211  if (Operand.isInvalid())
2212    return move(Operand);
2213
2214  return Actions.ActOnCXXDelete(Start, UseGlobal, ArrayDelete, Operand.take());
2215}
2216
2217static UnaryTypeTrait UnaryTypeTraitFromTokKind(tok::TokenKind kind) {
2218  switch(kind) {
2219  default: llvm_unreachable("Not a known unary type trait.");
2220  case tok::kw___has_nothrow_assign:      return UTT_HasNothrowAssign;
2221  case tok::kw___has_nothrow_constructor: return UTT_HasNothrowConstructor;
2222  case tok::kw___has_nothrow_copy:           return UTT_HasNothrowCopy;
2223  case tok::kw___has_trivial_assign:      return UTT_HasTrivialAssign;
2224  case tok::kw___has_trivial_constructor:
2225                                    return UTT_HasTrivialDefaultConstructor;
2226  case tok::kw___has_trivial_copy:           return UTT_HasTrivialCopy;
2227  case tok::kw___has_trivial_destructor:  return UTT_HasTrivialDestructor;
2228  case tok::kw___has_virtual_destructor:  return UTT_HasVirtualDestructor;
2229  case tok::kw___is_abstract:             return UTT_IsAbstract;
2230  case tok::kw___is_arithmetic:              return UTT_IsArithmetic;
2231  case tok::kw___is_array:                   return UTT_IsArray;
2232  case tok::kw___is_class:                return UTT_IsClass;
2233  case tok::kw___is_complete_type:           return UTT_IsCompleteType;
2234  case tok::kw___is_compound:                return UTT_IsCompound;
2235  case tok::kw___is_const:                   return UTT_IsConst;
2236  case tok::kw___is_empty:                return UTT_IsEmpty;
2237  case tok::kw___is_enum:                 return UTT_IsEnum;
2238  case tok::kw___is_floating_point:          return UTT_IsFloatingPoint;
2239  case tok::kw___is_function:                return UTT_IsFunction;
2240  case tok::kw___is_fundamental:             return UTT_IsFundamental;
2241  case tok::kw___is_integral:                return UTT_IsIntegral;
2242  case tok::kw___is_lvalue_reference:        return UTT_IsLvalueReference;
2243  case tok::kw___is_member_function_pointer: return UTT_IsMemberFunctionPointer;
2244  case tok::kw___is_member_object_pointer:   return UTT_IsMemberObjectPointer;
2245  case tok::kw___is_member_pointer:          return UTT_IsMemberPointer;
2246  case tok::kw___is_object:                  return UTT_IsObject;
2247  case tok::kw___is_literal:              return UTT_IsLiteral;
2248  case tok::kw___is_literal_type:         return UTT_IsLiteral;
2249  case tok::kw___is_pod:                  return UTT_IsPOD;
2250  case tok::kw___is_pointer:                 return UTT_IsPointer;
2251  case tok::kw___is_polymorphic:          return UTT_IsPolymorphic;
2252  case tok::kw___is_reference:               return UTT_IsReference;
2253  case tok::kw___is_rvalue_reference:        return UTT_IsRvalueReference;
2254  case tok::kw___is_scalar:                  return UTT_IsScalar;
2255  case tok::kw___is_signed:                  return UTT_IsSigned;
2256  case tok::kw___is_standard_layout:         return UTT_IsStandardLayout;
2257  case tok::kw___is_trivial:                 return UTT_IsTrivial;
2258  case tok::kw___is_trivially_copyable:      return UTT_IsTriviallyCopyable;
2259  case tok::kw___is_union:                return UTT_IsUnion;
2260  case tok::kw___is_unsigned:                return UTT_IsUnsigned;
2261  case tok::kw___is_void:                    return UTT_IsVoid;
2262  case tok::kw___is_volatile:                return UTT_IsVolatile;
2263  }
2264}
2265
2266static BinaryTypeTrait BinaryTypeTraitFromTokKind(tok::TokenKind kind) {
2267  switch(kind) {
2268  default: llvm_unreachable("Not a known binary type trait");
2269  case tok::kw___is_base_of:                 return BTT_IsBaseOf;
2270  case tok::kw___is_convertible:             return BTT_IsConvertible;
2271  case tok::kw___is_same:                    return BTT_IsSame;
2272  case tok::kw___builtin_types_compatible_p: return BTT_TypeCompatible;
2273  case tok::kw___is_convertible_to:          return BTT_IsConvertibleTo;
2274  }
2275}
2276
2277static ArrayTypeTrait ArrayTypeTraitFromTokKind(tok::TokenKind kind) {
2278  switch(kind) {
2279  default: llvm_unreachable("Not a known binary type trait");
2280  case tok::kw___array_rank:                 return ATT_ArrayRank;
2281  case tok::kw___array_extent:               return ATT_ArrayExtent;
2282  }
2283}
2284
2285static ExpressionTrait ExpressionTraitFromTokKind(tok::TokenKind kind) {
2286  switch(kind) {
2287  default: llvm_unreachable("Not a known unary expression trait.");
2288  case tok::kw___is_lvalue_expr:             return ET_IsLValueExpr;
2289  case tok::kw___is_rvalue_expr:             return ET_IsRValueExpr;
2290  }
2291}
2292
2293/// ParseUnaryTypeTrait - Parse the built-in unary type-trait
2294/// pseudo-functions that allow implementation of the TR1/C++0x type traits
2295/// templates.
2296///
2297///       primary-expression:
2298/// [GNU]             unary-type-trait '(' type-id ')'
2299///
2300ExprResult Parser::ParseUnaryTypeTrait() {
2301  UnaryTypeTrait UTT = UnaryTypeTraitFromTokKind(Tok.getKind());
2302  SourceLocation Loc = ConsumeToken();
2303
2304  BalancedDelimiterTracker T(*this, tok::l_paren);
2305  if (T.expectAndConsume(diag::err_expected_lparen))
2306    return ExprError();
2307
2308  // FIXME: Error reporting absolutely sucks! If the this fails to parse a type
2309  // there will be cryptic errors about mismatched parentheses and missing
2310  // specifiers.
2311  TypeResult Ty = ParseTypeName();
2312
2313  T.consumeClose();
2314
2315  if (Ty.isInvalid())
2316    return ExprError();
2317
2318  return Actions.ActOnUnaryTypeTrait(UTT, Loc, Ty.get(), T.getCloseLocation());
2319}
2320
2321/// ParseBinaryTypeTrait - Parse the built-in binary type-trait
2322/// pseudo-functions that allow implementation of the TR1/C++0x type traits
2323/// templates.
2324///
2325///       primary-expression:
2326/// [GNU]             binary-type-trait '(' type-id ',' type-id ')'
2327///
2328ExprResult Parser::ParseBinaryTypeTrait() {
2329  BinaryTypeTrait BTT = BinaryTypeTraitFromTokKind(Tok.getKind());
2330  SourceLocation Loc = ConsumeToken();
2331
2332  BalancedDelimiterTracker T(*this, tok::l_paren);
2333  if (T.expectAndConsume(diag::err_expected_lparen))
2334    return ExprError();
2335
2336  TypeResult LhsTy = ParseTypeName();
2337  if (LhsTy.isInvalid()) {
2338    SkipUntil(tok::r_paren);
2339    return ExprError();
2340  }
2341
2342  if (ExpectAndConsume(tok::comma, diag::err_expected_comma)) {
2343    SkipUntil(tok::r_paren);
2344    return ExprError();
2345  }
2346
2347  TypeResult RhsTy = ParseTypeName();
2348  if (RhsTy.isInvalid()) {
2349    SkipUntil(tok::r_paren);
2350    return ExprError();
2351  }
2352
2353  T.consumeClose();
2354
2355  return Actions.ActOnBinaryTypeTrait(BTT, Loc, LhsTy.get(), RhsTy.get(),
2356                                      T.getCloseLocation());
2357}
2358
2359/// ParseArrayTypeTrait - Parse the built-in array type-trait
2360/// pseudo-functions.
2361///
2362///       primary-expression:
2363/// [Embarcadero]     '__array_rank' '(' type-id ')'
2364/// [Embarcadero]     '__array_extent' '(' type-id ',' expression ')'
2365///
2366ExprResult Parser::ParseArrayTypeTrait() {
2367  ArrayTypeTrait ATT = ArrayTypeTraitFromTokKind(Tok.getKind());
2368  SourceLocation Loc = ConsumeToken();
2369
2370  BalancedDelimiterTracker T(*this, tok::l_paren);
2371  if (T.expectAndConsume(diag::err_expected_lparen))
2372    return ExprError();
2373
2374  TypeResult Ty = ParseTypeName();
2375  if (Ty.isInvalid()) {
2376    SkipUntil(tok::comma);
2377    SkipUntil(tok::r_paren);
2378    return ExprError();
2379  }
2380
2381  switch (ATT) {
2382  case ATT_ArrayRank: {
2383    T.consumeClose();
2384    return Actions.ActOnArrayTypeTrait(ATT, Loc, Ty.get(), NULL,
2385                                       T.getCloseLocation());
2386  }
2387  case ATT_ArrayExtent: {
2388    if (ExpectAndConsume(tok::comma, diag::err_expected_comma)) {
2389      SkipUntil(tok::r_paren);
2390      return ExprError();
2391    }
2392
2393    ExprResult DimExpr = ParseExpression();
2394    T.consumeClose();
2395
2396    return Actions.ActOnArrayTypeTrait(ATT, Loc, Ty.get(), DimExpr.get(),
2397                                       T.getCloseLocation());
2398  }
2399  default:
2400    break;
2401  }
2402  return ExprError();
2403}
2404
2405/// ParseExpressionTrait - Parse built-in expression-trait
2406/// pseudo-functions like __is_lvalue_expr( xxx ).
2407///
2408///       primary-expression:
2409/// [Embarcadero]     expression-trait '(' expression ')'
2410///
2411ExprResult Parser::ParseExpressionTrait() {
2412  ExpressionTrait ET = ExpressionTraitFromTokKind(Tok.getKind());
2413  SourceLocation Loc = ConsumeToken();
2414
2415  BalancedDelimiterTracker T(*this, tok::l_paren);
2416  if (T.expectAndConsume(diag::err_expected_lparen))
2417    return ExprError();
2418
2419  ExprResult Expr = ParseExpression();
2420
2421  T.consumeClose();
2422
2423  return Actions.ActOnExpressionTrait(ET, Loc, Expr.get(),
2424                                      T.getCloseLocation());
2425}
2426
2427
2428/// ParseCXXAmbiguousParenExpression - We have parsed the left paren of a
2429/// parenthesized ambiguous type-id. This uses tentative parsing to disambiguate
2430/// based on the context past the parens.
2431ExprResult
2432Parser::ParseCXXAmbiguousParenExpression(ParenParseOption &ExprType,
2433                                         ParsedType &CastTy,
2434                                         BalancedDelimiterTracker &Tracker) {
2435  assert(getLang().CPlusPlus && "Should only be called for C++!");
2436  assert(ExprType == CastExpr && "Compound literals are not ambiguous!");
2437  assert(isTypeIdInParens() && "Not a type-id!");
2438
2439  ExprResult Result(true);
2440  CastTy = ParsedType();
2441
2442  // We need to disambiguate a very ugly part of the C++ syntax:
2443  //
2444  // (T())x;  - type-id
2445  // (T())*x; - type-id
2446  // (T())/x; - expression
2447  // (T());   - expression
2448  //
2449  // The bad news is that we cannot use the specialized tentative parser, since
2450  // it can only verify that the thing inside the parens can be parsed as
2451  // type-id, it is not useful for determining the context past the parens.
2452  //
2453  // The good news is that the parser can disambiguate this part without
2454  // making any unnecessary Action calls.
2455  //
2456  // It uses a scheme similar to parsing inline methods. The parenthesized
2457  // tokens are cached, the context that follows is determined (possibly by
2458  // parsing a cast-expression), and then we re-introduce the cached tokens
2459  // into the token stream and parse them appropriately.
2460
2461  ParenParseOption ParseAs;
2462  CachedTokens Toks;
2463
2464  // Store the tokens of the parentheses. We will parse them after we determine
2465  // the context that follows them.
2466  if (!ConsumeAndStoreUntil(tok::r_paren, Toks)) {
2467    // We didn't find the ')' we expected.
2468    Tracker.consumeClose();
2469    return ExprError();
2470  }
2471
2472  if (Tok.is(tok::l_brace)) {
2473    ParseAs = CompoundLiteral;
2474  } else {
2475    bool NotCastExpr;
2476    // FIXME: Special-case ++ and --: "(S())++;" is not a cast-expression
2477    if (Tok.is(tok::l_paren) && NextToken().is(tok::r_paren)) {
2478      NotCastExpr = true;
2479    } else {
2480      // Try parsing the cast-expression that may follow.
2481      // If it is not a cast-expression, NotCastExpr will be true and no token
2482      // will be consumed.
2483      Result = ParseCastExpression(false/*isUnaryExpression*/,
2484                                   false/*isAddressofOperand*/,
2485                                   NotCastExpr,
2486                                   // type-id has priority.
2487                                   true/*isTypeCast*/);
2488    }
2489
2490    // If we parsed a cast-expression, it's really a type-id, otherwise it's
2491    // an expression.
2492    ParseAs = NotCastExpr ? SimpleExpr : CastExpr;
2493  }
2494
2495  // The current token should go after the cached tokens.
2496  Toks.push_back(Tok);
2497  // Re-enter the stored parenthesized tokens into the token stream, so we may
2498  // parse them now.
2499  PP.EnterTokenStream(Toks.data(), Toks.size(),
2500                      true/*DisableMacroExpansion*/, false/*OwnsTokens*/);
2501  // Drop the current token and bring the first cached one. It's the same token
2502  // as when we entered this function.
2503  ConsumeAnyToken();
2504
2505  if (ParseAs >= CompoundLiteral) {
2506    // Parse the type declarator.
2507    DeclSpec DS(AttrFactory);
2508    ParseSpecifierQualifierList(DS);
2509    Declarator DeclaratorInfo(DS, Declarator::TypeNameContext);
2510    ParseDeclarator(DeclaratorInfo);
2511
2512    // Match the ')'.
2513    Tracker.consumeClose();
2514
2515    if (ParseAs == CompoundLiteral) {
2516      ExprType = CompoundLiteral;
2517      TypeResult Ty = ParseTypeName();
2518       return ParseCompoundLiteralExpression(Ty.get(),
2519                                            Tracker.getOpenLocation(),
2520                                            Tracker.getCloseLocation());
2521    }
2522
2523    // We parsed '(' type-id ')' and the thing after it wasn't a '{'.
2524    assert(ParseAs == CastExpr);
2525
2526    if (DeclaratorInfo.isInvalidType())
2527      return ExprError();
2528
2529    // Result is what ParseCastExpression returned earlier.
2530    if (!Result.isInvalid())
2531      Result = Actions.ActOnCastExpr(getCurScope(), Tracker.getOpenLocation(),
2532                                    DeclaratorInfo, CastTy,
2533                                    Tracker.getCloseLocation(), Result.take());
2534    return move(Result);
2535  }
2536
2537  // Not a compound literal, and not followed by a cast-expression.
2538  assert(ParseAs == SimpleExpr);
2539
2540  ExprType = SimpleExpr;
2541  Result = ParseExpression();
2542  if (!Result.isInvalid() && Tok.is(tok::r_paren))
2543    Result = Actions.ActOnParenExpr(Tracker.getOpenLocation(),
2544                                    Tok.getLocation(), Result.take());
2545
2546  // Match the ')'.
2547  if (Result.isInvalid()) {
2548    SkipUntil(tok::r_paren);
2549    return ExprError();
2550  }
2551
2552  Tracker.consumeClose();
2553  return move(Result);
2554}
2555