ParseExprCXX.cpp revision 7fe6208c3fa91f835813bb78236ef5c2bbf81053 
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  Diag(Intro.Range.getBegin(), diag::warn_cxx98_compat_lambda);
683
684  // Parse lambda-declarator[opt].
685  DeclSpec DS(AttrFactory);
686  Declarator D(DS, Declarator::PrototypeContext);
687
688  if (Tok.is(tok::l_paren)) {
689    ParseScope PrototypeScope(this,
690                              Scope::FunctionPrototypeScope |
691                              Scope::DeclScope);
692
693    SourceLocation DeclLoc, DeclEndLoc;
694    BalancedDelimiterTracker T(*this, tok::l_paren);
695    T.consumeOpen();
696    DeclLoc = T.getOpenLocation();
697
698    // Parse parameter-declaration-clause.
699    ParsedAttributes Attr(AttrFactory);
700    llvm::SmallVector<DeclaratorChunk::ParamInfo, 16> ParamInfo;
701    SourceLocation EllipsisLoc;
702
703    if (Tok.isNot(tok::r_paren))
704      ParseParameterDeclarationClause(D, Attr, ParamInfo, EllipsisLoc);
705
706    T.consumeClose();
707    DeclEndLoc = T.getCloseLocation();
708
709    // Parse 'mutable'[opt].
710    SourceLocation MutableLoc;
711    if (Tok.is(tok::kw_mutable)) {
712      MutableLoc = ConsumeToken();
713      DeclEndLoc = MutableLoc;
714    }
715
716    // Parse exception-specification[opt].
717    ExceptionSpecificationType ESpecType = EST_None;
718    SourceRange ESpecRange;
719    llvm::SmallVector<ParsedType, 2> DynamicExceptions;
720    llvm::SmallVector<SourceRange, 2> DynamicExceptionRanges;
721    ExprResult NoexceptExpr;
722    ESpecType = MaybeParseExceptionSpecification(ESpecRange,
723                                                 DynamicExceptions,
724                                                 DynamicExceptionRanges,
725                                                 NoexceptExpr);
726
727    if (ESpecType != EST_None)
728      DeclEndLoc = ESpecRange.getEnd();
729
730    // Parse attribute-specifier[opt].
731    MaybeParseCXX0XAttributes(Attr, &DeclEndLoc);
732
733    // Parse trailing-return-type[opt].
734    ParsedType TrailingReturnType;
735    if (Tok.is(tok::arrow)) {
736      SourceRange Range;
737      TrailingReturnType = ParseTrailingReturnType(Range).get();
738      if (Range.getEnd().isValid())
739        DeclEndLoc = Range.getEnd();
740    }
741
742    PrototypeScope.Exit();
743
744    D.AddTypeInfo(DeclaratorChunk::getFunction(/*hasProto=*/true,
745                                           /*isVariadic=*/EllipsisLoc.isValid(),
746                                           EllipsisLoc,
747                                           ParamInfo.data(), ParamInfo.size(),
748                                           DS.getTypeQualifiers(),
749                                           /*RefQualifierIsLValueRef=*/true,
750                                           /*RefQualifierLoc=*/SourceLocation(),
751                                           MutableLoc,
752                                           ESpecType, ESpecRange.getBegin(),
753                                           DynamicExceptions.data(),
754                                           DynamicExceptionRanges.data(),
755                                           DynamicExceptions.size(),
756                                           NoexceptExpr.isUsable() ?
757                                             NoexceptExpr.get() : 0,
758                                           DeclLoc, DeclEndLoc, D,
759                                           TrailingReturnType),
760                  Attr, DeclEndLoc);
761  }
762
763  // Parse compound-statement.
764  if (Tok.is(tok::l_brace)) {
765    // FIXME: Rename BlockScope -> ClosureScope if we decide to continue using
766    // it.
767    ParseScope BodyScope(this, Scope::BlockScope | Scope::FnScope |
768                               Scope::BreakScope | Scope::ContinueScope |
769                               Scope::DeclScope);
770
771    StmtResult Stmt(ParseCompoundStatementBody());
772
773    BodyScope.Exit();
774  } else {
775    Diag(Tok, diag::err_expected_lambda_body);
776  }
777
778  return ExprEmpty();
779}
780
781/// ParseCXXCasts - This handles the various ways to cast expressions to another
782/// type.
783///
784///       postfix-expression: [C++ 5.2p1]
785///         'dynamic_cast' '<' type-name '>' '(' expression ')'
786///         'static_cast' '<' type-name '>' '(' expression ')'
787///         'reinterpret_cast' '<' type-name '>' '(' expression ')'
788///         'const_cast' '<' type-name '>' '(' expression ')'
789///
790ExprResult Parser::ParseCXXCasts() {
791  tok::TokenKind Kind = Tok.getKind();
792  const char *CastName = 0;     // For error messages
793
794  switch (Kind) {
795  default: llvm_unreachable("Unknown C++ cast!");
796  case tok::kw_const_cast:       CastName = "const_cast";       break;
797  case tok::kw_dynamic_cast:     CastName = "dynamic_cast";     break;
798  case tok::kw_reinterpret_cast: CastName = "reinterpret_cast"; break;
799  case tok::kw_static_cast:      CastName = "static_cast";      break;
800  }
801
802  SourceLocation OpLoc = ConsumeToken();
803  SourceLocation LAngleBracketLoc = Tok.getLocation();
804
805  // Check for "<::" which is parsed as "[:".  If found, fix token stream,
806  // diagnose error, suggest fix, and recover parsing.
807  Token Next = NextToken();
808  if (Tok.is(tok::l_square) && Tok.getLength() == 2 && Next.is(tok::colon) &&
809      AreTokensAdjacent(PP, Tok, Next))
810    FixDigraph(*this, PP, Tok, Next, Kind, /*AtDigraph*/true);
811
812  if (ExpectAndConsume(tok::less, diag::err_expected_less_after, CastName))
813    return ExprError();
814
815  // Parse the common declaration-specifiers piece.
816  DeclSpec DS(AttrFactory);
817  ParseSpecifierQualifierList(DS);
818
819  // Parse the abstract-declarator, if present.
820  Declarator DeclaratorInfo(DS, Declarator::TypeNameContext);
821  ParseDeclarator(DeclaratorInfo);
822
823  SourceLocation RAngleBracketLoc = Tok.getLocation();
824
825  if (ExpectAndConsume(tok::greater, diag::err_expected_greater))
826    return ExprError(Diag(LAngleBracketLoc, diag::note_matching) << "<");
827
828  SourceLocation LParenLoc, RParenLoc;
829  BalancedDelimiterTracker T(*this, tok::l_paren);
830
831  if (T.expectAndConsume(diag::err_expected_lparen_after, CastName))
832    return ExprError();
833
834  ExprResult Result = ParseExpression();
835
836  // Match the ')'.
837  T.consumeClose();
838
839  if (!Result.isInvalid() && !DeclaratorInfo.isInvalidType())
840    Result = Actions.ActOnCXXNamedCast(OpLoc, Kind,
841                                       LAngleBracketLoc, DeclaratorInfo,
842                                       RAngleBracketLoc,
843                                       T.getOpenLocation(), Result.take(),
844                                       T.getCloseLocation());
845
846  return move(Result);
847}
848
849/// ParseCXXTypeid - This handles the C++ typeid expression.
850///
851///       postfix-expression: [C++ 5.2p1]
852///         'typeid' '(' expression ')'
853///         'typeid' '(' type-id ')'
854///
855ExprResult Parser::ParseCXXTypeid() {
856  assert(Tok.is(tok::kw_typeid) && "Not 'typeid'!");
857
858  SourceLocation OpLoc = ConsumeToken();
859  SourceLocation LParenLoc, RParenLoc;
860  BalancedDelimiterTracker T(*this, tok::l_paren);
861
862  // typeid expressions are always parenthesized.
863  if (T.expectAndConsume(diag::err_expected_lparen_after, "typeid"))
864    return ExprError();
865  LParenLoc = T.getOpenLocation();
866
867  ExprResult Result;
868
869  if (isTypeIdInParens()) {
870    TypeResult Ty = ParseTypeName();
871
872    // Match the ')'.
873    T.consumeClose();
874    RParenLoc = T.getCloseLocation();
875    if (Ty.isInvalid() || RParenLoc.isInvalid())
876      return ExprError();
877
878    Result = Actions.ActOnCXXTypeid(OpLoc, LParenLoc, /*isType=*/true,
879                                    Ty.get().getAsOpaquePtr(), RParenLoc);
880  } else {
881    // C++0x [expr.typeid]p3:
882    //   When typeid is applied to an expression other than an lvalue of a
883    //   polymorphic class type [...] The expression is an unevaluated
884    //   operand (Clause 5).
885    //
886    // Note that we can't tell whether the expression is an lvalue of a
887    // polymorphic class type until after we've parsed the expression, so
888    // we the expression is potentially potentially evaluated.
889    EnterExpressionEvaluationContext Unevaluated(Actions,
890                                       Sema::PotentiallyPotentiallyEvaluated);
891    Result = ParseExpression();
892
893    // Match the ')'.
894    if (Result.isInvalid())
895      SkipUntil(tok::r_paren);
896    else {
897      T.consumeClose();
898      RParenLoc = T.getCloseLocation();
899      if (RParenLoc.isInvalid())
900        return ExprError();
901
902      Result = Actions.ActOnCXXTypeid(OpLoc, LParenLoc, /*isType=*/false,
903                                      Result.release(), RParenLoc);
904    }
905  }
906
907  return move(Result);
908}
909
910/// ParseCXXUuidof - This handles the Microsoft C++ __uuidof expression.
911///
912///         '__uuidof' '(' expression ')'
913///         '__uuidof' '(' type-id ')'
914///
915ExprResult Parser::ParseCXXUuidof() {
916  assert(Tok.is(tok::kw___uuidof) && "Not '__uuidof'!");
917
918  SourceLocation OpLoc = ConsumeToken();
919  BalancedDelimiterTracker T(*this, tok::l_paren);
920
921  // __uuidof expressions are always parenthesized.
922  if (T.expectAndConsume(diag::err_expected_lparen_after, "__uuidof"))
923    return ExprError();
924
925  ExprResult Result;
926
927  if (isTypeIdInParens()) {
928    TypeResult Ty = ParseTypeName();
929
930    // Match the ')'.
931    T.consumeClose();
932
933    if (Ty.isInvalid())
934      return ExprError();
935
936    Result = Actions.ActOnCXXUuidof(OpLoc, T.getOpenLocation(), /*isType=*/true,
937                                    Ty.get().getAsOpaquePtr(),
938                                    T.getCloseLocation());
939  } else {
940    EnterExpressionEvaluationContext Unevaluated(Actions, Sema::Unevaluated);
941    Result = ParseExpression();
942
943    // Match the ')'.
944    if (Result.isInvalid())
945      SkipUntil(tok::r_paren);
946    else {
947      T.consumeClose();
948
949      Result = Actions.ActOnCXXUuidof(OpLoc, T.getOpenLocation(),
950                                      /*isType=*/false,
951                                      Result.release(), T.getCloseLocation());
952    }
953  }
954
955  return move(Result);
956}
957
958/// \brief Parse a C++ pseudo-destructor expression after the base,
959/// . or -> operator, and nested-name-specifier have already been
960/// parsed.
961///
962///       postfix-expression: [C++ 5.2]
963///         postfix-expression . pseudo-destructor-name
964///         postfix-expression -> pseudo-destructor-name
965///
966///       pseudo-destructor-name:
967///         ::[opt] nested-name-specifier[opt] type-name :: ~type-name
968///         ::[opt] nested-name-specifier template simple-template-id ::
969///                 ~type-name
970///         ::[opt] nested-name-specifier[opt] ~type-name
971///
972ExprResult
973Parser::ParseCXXPseudoDestructor(ExprArg Base, SourceLocation OpLoc,
974                                 tok::TokenKind OpKind,
975                                 CXXScopeSpec &SS,
976                                 ParsedType ObjectType) {
977  // We're parsing either a pseudo-destructor-name or a dependent
978  // member access that has the same form as a
979  // pseudo-destructor-name. We parse both in the same way and let
980  // the action model sort them out.
981  //
982  // Note that the ::[opt] nested-name-specifier[opt] has already
983  // been parsed, and if there was a simple-template-id, it has
984  // been coalesced into a template-id annotation token.
985  UnqualifiedId FirstTypeName;
986  SourceLocation CCLoc;
987  if (Tok.is(tok::identifier)) {
988    FirstTypeName.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
989    ConsumeToken();
990    assert(Tok.is(tok::coloncolon) &&"ParseOptionalCXXScopeSpecifier fail");
991    CCLoc = ConsumeToken();
992  } else if (Tok.is(tok::annot_template_id)) {
993    FirstTypeName.setTemplateId(
994                              (TemplateIdAnnotation *)Tok.getAnnotationValue());
995    ConsumeToken();
996    assert(Tok.is(tok::coloncolon) &&"ParseOptionalCXXScopeSpecifier fail");
997    CCLoc = ConsumeToken();
998  } else {
999    FirstTypeName.setIdentifier(0, SourceLocation());
1000  }
1001
1002  // Parse the tilde.
1003  assert(Tok.is(tok::tilde) && "ParseOptionalCXXScopeSpecifier fail");
1004  SourceLocation TildeLoc = ConsumeToken();
1005  if (!Tok.is(tok::identifier)) {
1006    Diag(Tok, diag::err_destructor_tilde_identifier);
1007    return ExprError();
1008  }
1009
1010  // Parse the second type.
1011  UnqualifiedId SecondTypeName;
1012  IdentifierInfo *Name = Tok.getIdentifierInfo();
1013  SourceLocation NameLoc = ConsumeToken();
1014  SecondTypeName.setIdentifier(Name, NameLoc);
1015
1016  // If there is a '<', the second type name is a template-id. Parse
1017  // it as such.
1018  if (Tok.is(tok::less) &&
1019      ParseUnqualifiedIdTemplateId(SS, Name, NameLoc, false, ObjectType,
1020                                   SecondTypeName, /*AssumeTemplateName=*/true,
1021                                   /*TemplateKWLoc*/SourceLocation()))
1022    return ExprError();
1023
1024  return Actions.ActOnPseudoDestructorExpr(getCurScope(), Base,
1025                                           OpLoc, OpKind,
1026                                           SS, FirstTypeName, CCLoc,
1027                                           TildeLoc, SecondTypeName,
1028                                           Tok.is(tok::l_paren));
1029}
1030
1031/// ParseCXXBoolLiteral - This handles the C++ Boolean literals.
1032///
1033///       boolean-literal: [C++ 2.13.5]
1034///         'true'
1035///         'false'
1036ExprResult Parser::ParseCXXBoolLiteral() {
1037  tok::TokenKind Kind = Tok.getKind();
1038  return Actions.ActOnCXXBoolLiteral(ConsumeToken(), Kind);
1039}
1040
1041/// ParseThrowExpression - This handles the C++ throw expression.
1042///
1043///       throw-expression: [C++ 15]
1044///         'throw' assignment-expression[opt]
1045ExprResult Parser::ParseThrowExpression() {
1046  assert(Tok.is(tok::kw_throw) && "Not throw!");
1047  SourceLocation ThrowLoc = ConsumeToken();           // Eat the throw token.
1048
1049  // If the current token isn't the start of an assignment-expression,
1050  // then the expression is not present.  This handles things like:
1051  //   "C ? throw : (void)42", which is crazy but legal.
1052  switch (Tok.getKind()) {  // FIXME: move this predicate somewhere common.
1053  case tok::semi:
1054  case tok::r_paren:
1055  case tok::r_square:
1056  case tok::r_brace:
1057  case tok::colon:
1058  case tok::comma:
1059    return Actions.ActOnCXXThrow(getCurScope(), ThrowLoc, 0);
1060
1061  default:
1062    ExprResult Expr(ParseAssignmentExpression());
1063    if (Expr.isInvalid()) return move(Expr);
1064    return Actions.ActOnCXXThrow(getCurScope(), ThrowLoc, Expr.take());
1065  }
1066}
1067
1068/// ParseCXXThis - This handles the C++ 'this' pointer.
1069///
1070/// C++ 9.3.2: In the body of a non-static member function, the keyword this is
1071/// a non-lvalue expression whose value is the address of the object for which
1072/// the function is called.
1073ExprResult Parser::ParseCXXThis() {
1074  assert(Tok.is(tok::kw_this) && "Not 'this'!");
1075  SourceLocation ThisLoc = ConsumeToken();
1076  return Actions.ActOnCXXThis(ThisLoc);
1077}
1078
1079/// ParseCXXTypeConstructExpression - Parse construction of a specified type.
1080/// Can be interpreted either as function-style casting ("int(x)")
1081/// or class type construction ("ClassType(x,y,z)")
1082/// or creation of a value-initialized type ("int()").
1083/// See [C++ 5.2.3].
1084///
1085///       postfix-expression: [C++ 5.2p1]
1086///         simple-type-specifier '(' expression-list[opt] ')'
1087/// [C++0x] simple-type-specifier braced-init-list
1088///         typename-specifier '(' expression-list[opt] ')'
1089/// [C++0x] typename-specifier braced-init-list
1090///
1091ExprResult
1092Parser::ParseCXXTypeConstructExpression(const DeclSpec &DS) {
1093  Declarator DeclaratorInfo(DS, Declarator::TypeNameContext);
1094  ParsedType TypeRep = Actions.ActOnTypeName(getCurScope(), DeclaratorInfo).get();
1095
1096  assert((Tok.is(tok::l_paren) ||
1097          (getLang().CPlusPlus0x && Tok.is(tok::l_brace)))
1098         && "Expected '(' or '{'!");
1099
1100  if (Tok.is(tok::l_brace)) {
1101
1102    // FIXME: Convert to a proper type construct expression.
1103    return ParseBraceInitializer();
1104
1105  } else {
1106    GreaterThanIsOperatorScope G(GreaterThanIsOperator, true);
1107
1108    BalancedDelimiterTracker T(*this, tok::l_paren);
1109    T.consumeOpen();
1110
1111    ExprVector Exprs(Actions);
1112    CommaLocsTy CommaLocs;
1113
1114    if (Tok.isNot(tok::r_paren)) {
1115      if (ParseExpressionList(Exprs, CommaLocs)) {
1116        SkipUntil(tok::r_paren);
1117        return ExprError();
1118      }
1119    }
1120
1121    // Match the ')'.
1122    T.consumeClose();
1123
1124    // TypeRep could be null, if it references an invalid typedef.
1125    if (!TypeRep)
1126      return ExprError();
1127
1128    assert((Exprs.size() == 0 || Exprs.size()-1 == CommaLocs.size())&&
1129           "Unexpected number of commas!");
1130    return Actions.ActOnCXXTypeConstructExpr(TypeRep, T.getOpenLocation(),
1131                                             move_arg(Exprs),
1132                                             T.getCloseLocation());
1133  }
1134}
1135
1136/// ParseCXXCondition - if/switch/while condition expression.
1137///
1138///       condition:
1139///         expression
1140///         type-specifier-seq declarator '=' assignment-expression
1141/// [GNU]   type-specifier-seq declarator simple-asm-expr[opt] attributes[opt]
1142///             '=' assignment-expression
1143///
1144/// \param ExprResult if the condition was parsed as an expression, the
1145/// parsed expression.
1146///
1147/// \param DeclResult if the condition was parsed as a declaration, the
1148/// parsed declaration.
1149///
1150/// \param Loc The location of the start of the statement that requires this
1151/// condition, e.g., the "for" in a for loop.
1152///
1153/// \param ConvertToBoolean Whether the condition expression should be
1154/// converted to a boolean value.
1155///
1156/// \returns true if there was a parsing, false otherwise.
1157bool Parser::ParseCXXCondition(ExprResult &ExprOut,
1158                               Decl *&DeclOut,
1159                               SourceLocation Loc,
1160                               bool ConvertToBoolean) {
1161  if (Tok.is(tok::code_completion)) {
1162    Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Condition);
1163    cutOffParsing();
1164    return true;
1165  }
1166
1167  if (!isCXXConditionDeclaration()) {
1168    // Parse the expression.
1169    ExprOut = ParseExpression(); // expression
1170    DeclOut = 0;
1171    if (ExprOut.isInvalid())
1172      return true;
1173
1174    // If required, convert to a boolean value.
1175    if (ConvertToBoolean)
1176      ExprOut
1177        = Actions.ActOnBooleanCondition(getCurScope(), Loc, ExprOut.get());
1178    return ExprOut.isInvalid();
1179  }
1180
1181  // type-specifier-seq
1182  DeclSpec DS(AttrFactory);
1183  ParseSpecifierQualifierList(DS);
1184
1185  // declarator
1186  Declarator DeclaratorInfo(DS, Declarator::ConditionContext);
1187  ParseDeclarator(DeclaratorInfo);
1188
1189  // simple-asm-expr[opt]
1190  if (Tok.is(tok::kw_asm)) {
1191    SourceLocation Loc;
1192    ExprResult AsmLabel(ParseSimpleAsm(&Loc));
1193    if (AsmLabel.isInvalid()) {
1194      SkipUntil(tok::semi);
1195      return true;
1196    }
1197    DeclaratorInfo.setAsmLabel(AsmLabel.release());
1198    DeclaratorInfo.SetRangeEnd(Loc);
1199  }
1200
1201  // If attributes are present, parse them.
1202  MaybeParseGNUAttributes(DeclaratorInfo);
1203
1204  // Type-check the declaration itself.
1205  DeclResult Dcl = Actions.ActOnCXXConditionDeclaration(getCurScope(),
1206                                                        DeclaratorInfo);
1207  DeclOut = Dcl.get();
1208  ExprOut = ExprError();
1209
1210  // '=' assignment-expression
1211  if (isTokenEqualOrMistypedEqualEqual(
1212                               diag::err_invalid_equalequal_after_declarator)) {
1213    ConsumeToken();
1214    ExprResult AssignExpr(ParseAssignmentExpression());
1215    if (!AssignExpr.isInvalid())
1216      Actions.AddInitializerToDecl(DeclOut, AssignExpr.take(), false,
1217                                   DS.getTypeSpecType() == DeclSpec::TST_auto);
1218  } else {
1219    // FIXME: C++0x allows a braced-init-list
1220    Diag(Tok, diag::err_expected_equal_after_declarator);
1221  }
1222
1223  // FIXME: Build a reference to this declaration? Convert it to bool?
1224  // (This is currently handled by Sema).
1225
1226  Actions.FinalizeDeclaration(DeclOut);
1227
1228  return false;
1229}
1230
1231/// \brief Determine whether the current token starts a C++
1232/// simple-type-specifier.
1233bool Parser::isCXXSimpleTypeSpecifier() const {
1234  switch (Tok.getKind()) {
1235  case tok::annot_typename:
1236  case tok::kw_short:
1237  case tok::kw_long:
1238  case tok::kw___int64:
1239  case tok::kw_signed:
1240  case tok::kw_unsigned:
1241  case tok::kw_void:
1242  case tok::kw_char:
1243  case tok::kw_int:
1244  case tok::kw_half:
1245  case tok::kw_float:
1246  case tok::kw_double:
1247  case tok::kw_wchar_t:
1248  case tok::kw_char16_t:
1249  case tok::kw_char32_t:
1250  case tok::kw_bool:
1251  case tok::kw_decltype:
1252  case tok::kw_typeof:
1253  case tok::kw___underlying_type:
1254    return true;
1255
1256  default:
1257    break;
1258  }
1259
1260  return false;
1261}
1262
1263/// ParseCXXSimpleTypeSpecifier - [C++ 7.1.5.2] Simple type specifiers.
1264/// This should only be called when the current token is known to be part of
1265/// simple-type-specifier.
1266///
1267///       simple-type-specifier:
1268///         '::'[opt] nested-name-specifier[opt] type-name
1269///         '::'[opt] nested-name-specifier 'template' simple-template-id [TODO]
1270///         char
1271///         wchar_t
1272///         bool
1273///         short
1274///         int
1275///         long
1276///         signed
1277///         unsigned
1278///         float
1279///         double
1280///         void
1281/// [GNU]   typeof-specifier
1282/// [C++0x] auto               [TODO]
1283///
1284///       type-name:
1285///         class-name
1286///         enum-name
1287///         typedef-name
1288///
1289void Parser::ParseCXXSimpleTypeSpecifier(DeclSpec &DS) {
1290  DS.SetRangeStart(Tok.getLocation());
1291  const char *PrevSpec;
1292  unsigned DiagID;
1293  SourceLocation Loc = Tok.getLocation();
1294
1295  switch (Tok.getKind()) {
1296  case tok::identifier:   // foo::bar
1297  case tok::coloncolon:   // ::foo::bar
1298    llvm_unreachable("Annotation token should already be formed!");
1299  default:
1300    llvm_unreachable("Not a simple-type-specifier token!");
1301
1302  // type-name
1303  case tok::annot_typename: {
1304    if (getTypeAnnotation(Tok))
1305      DS.SetTypeSpecType(DeclSpec::TST_typename, Loc, PrevSpec, DiagID,
1306                         getTypeAnnotation(Tok));
1307    else
1308      DS.SetTypeSpecError();
1309
1310    DS.SetRangeEnd(Tok.getAnnotationEndLoc());
1311    ConsumeToken();
1312
1313    // Objective-C supports syntax of the form 'id<proto1,proto2>' where 'id'
1314    // is a specific typedef and 'itf<proto1,proto2>' where 'itf' is an
1315    // Objective-C interface.  If we don't have Objective-C or a '<', this is
1316    // just a normal reference to a typedef name.
1317    if (Tok.is(tok::less) && getLang().ObjC1)
1318      ParseObjCProtocolQualifiers(DS);
1319
1320    DS.Finish(Diags, PP);
1321    return;
1322  }
1323
1324  // builtin types
1325  case tok::kw_short:
1326    DS.SetTypeSpecWidth(DeclSpec::TSW_short, Loc, PrevSpec, DiagID);
1327    break;
1328  case tok::kw_long:
1329    DS.SetTypeSpecWidth(DeclSpec::TSW_long, Loc, PrevSpec, DiagID);
1330    break;
1331  case tok::kw___int64:
1332    DS.SetTypeSpecWidth(DeclSpec::TSW_longlong, Loc, PrevSpec, DiagID);
1333    break;
1334  case tok::kw_signed:
1335    DS.SetTypeSpecSign(DeclSpec::TSS_signed, Loc, PrevSpec, DiagID);
1336    break;
1337  case tok::kw_unsigned:
1338    DS.SetTypeSpecSign(DeclSpec::TSS_unsigned, Loc, PrevSpec, DiagID);
1339    break;
1340  case tok::kw_void:
1341    DS.SetTypeSpecType(DeclSpec::TST_void, Loc, PrevSpec, DiagID);
1342    break;
1343  case tok::kw_char:
1344    DS.SetTypeSpecType(DeclSpec::TST_char, Loc, PrevSpec, DiagID);
1345    break;
1346  case tok::kw_int:
1347    DS.SetTypeSpecType(DeclSpec::TST_int, Loc, PrevSpec, DiagID);
1348    break;
1349  case tok::kw_half:
1350    DS.SetTypeSpecType(DeclSpec::TST_half, Loc, PrevSpec, DiagID);
1351    break;
1352  case tok::kw_float:
1353    DS.SetTypeSpecType(DeclSpec::TST_float, Loc, PrevSpec, DiagID);
1354    break;
1355  case tok::kw_double:
1356    DS.SetTypeSpecType(DeclSpec::TST_double, Loc, PrevSpec, DiagID);
1357    break;
1358  case tok::kw_wchar_t:
1359    DS.SetTypeSpecType(DeclSpec::TST_wchar, Loc, PrevSpec, DiagID);
1360    break;
1361  case tok::kw_char16_t:
1362    DS.SetTypeSpecType(DeclSpec::TST_char16, Loc, PrevSpec, DiagID);
1363    break;
1364  case tok::kw_char32_t:
1365    DS.SetTypeSpecType(DeclSpec::TST_char32, Loc, PrevSpec, DiagID);
1366    break;
1367  case tok::kw_bool:
1368    DS.SetTypeSpecType(DeclSpec::TST_bool, Loc, PrevSpec, DiagID);
1369    break;
1370
1371    // FIXME: C++0x decltype support.
1372  // GNU typeof support.
1373  case tok::kw_typeof:
1374    ParseTypeofSpecifier(DS);
1375    DS.Finish(Diags, PP);
1376    return;
1377  }
1378  if (Tok.is(tok::annot_typename))
1379    DS.SetRangeEnd(Tok.getAnnotationEndLoc());
1380  else
1381    DS.SetRangeEnd(Tok.getLocation());
1382  ConsumeToken();
1383  DS.Finish(Diags, PP);
1384}
1385
1386/// ParseCXXTypeSpecifierSeq - Parse a C++ type-specifier-seq (C++
1387/// [dcl.name]), which is a non-empty sequence of type-specifiers,
1388/// e.g., "const short int". Note that the DeclSpec is *not* finished
1389/// by parsing the type-specifier-seq, because these sequences are
1390/// typically followed by some form of declarator. Returns true and
1391/// emits diagnostics if this is not a type-specifier-seq, false
1392/// otherwise.
1393///
1394///   type-specifier-seq: [C++ 8.1]
1395///     type-specifier type-specifier-seq[opt]
1396///
1397bool Parser::ParseCXXTypeSpecifierSeq(DeclSpec &DS) {
1398  DS.SetRangeStart(Tok.getLocation());
1399  const char *PrevSpec = 0;
1400  unsigned DiagID;
1401  bool isInvalid = 0;
1402
1403  // Parse one or more of the type specifiers.
1404  if (!ParseOptionalTypeSpecifier(DS, isInvalid, PrevSpec, DiagID,
1405      ParsedTemplateInfo(), /*SuppressDeclarations*/true)) {
1406    Diag(Tok, diag::err_expected_type);
1407    return true;
1408  }
1409
1410  while (ParseOptionalTypeSpecifier(DS, isInvalid, PrevSpec, DiagID,
1411         ParsedTemplateInfo(), /*SuppressDeclarations*/true))
1412  {}
1413
1414  DS.Finish(Diags, PP);
1415  return false;
1416}
1417
1418/// \brief Finish parsing a C++ unqualified-id that is a template-id of
1419/// some form.
1420///
1421/// This routine is invoked when a '<' is encountered after an identifier or
1422/// operator-function-id is parsed by \c ParseUnqualifiedId() to determine
1423/// whether the unqualified-id is actually a template-id. This routine will
1424/// then parse the template arguments and form the appropriate template-id to
1425/// return to the caller.
1426///
1427/// \param SS the nested-name-specifier that precedes this template-id, if
1428/// we're actually parsing a qualified-id.
1429///
1430/// \param Name for constructor and destructor names, this is the actual
1431/// identifier that may be a template-name.
1432///
1433/// \param NameLoc the location of the class-name in a constructor or
1434/// destructor.
1435///
1436/// \param EnteringContext whether we're entering the scope of the
1437/// nested-name-specifier.
1438///
1439/// \param ObjectType if this unqualified-id occurs within a member access
1440/// expression, the type of the base object whose member is being accessed.
1441///
1442/// \param Id as input, describes the template-name or operator-function-id
1443/// that precedes the '<'. If template arguments were parsed successfully,
1444/// will be updated with the template-id.
1445///
1446/// \param AssumeTemplateId When true, this routine will assume that the name
1447/// refers to a template without performing name lookup to verify.
1448///
1449/// \returns true if a parse error occurred, false otherwise.
1450bool Parser::ParseUnqualifiedIdTemplateId(CXXScopeSpec &SS,
1451                                          IdentifierInfo *Name,
1452                                          SourceLocation NameLoc,
1453                                          bool EnteringContext,
1454                                          ParsedType ObjectType,
1455                                          UnqualifiedId &Id,
1456                                          bool AssumeTemplateId,
1457                                          SourceLocation TemplateKWLoc) {
1458  assert((AssumeTemplateId || Tok.is(tok::less)) &&
1459         "Expected '<' to finish parsing a template-id");
1460
1461  TemplateTy Template;
1462  TemplateNameKind TNK = TNK_Non_template;
1463  switch (Id.getKind()) {
1464  case UnqualifiedId::IK_Identifier:
1465  case UnqualifiedId::IK_OperatorFunctionId:
1466  case UnqualifiedId::IK_LiteralOperatorId:
1467    if (AssumeTemplateId) {
1468      TNK = Actions.ActOnDependentTemplateName(getCurScope(), TemplateKWLoc, SS,
1469                                               Id, ObjectType, EnteringContext,
1470                                               Template);
1471      if (TNK == TNK_Non_template)
1472        return true;
1473    } else {
1474      bool MemberOfUnknownSpecialization;
1475      TNK = Actions.isTemplateName(getCurScope(), SS,
1476                                   TemplateKWLoc.isValid(), Id,
1477                                   ObjectType, EnteringContext, Template,
1478                                   MemberOfUnknownSpecialization);
1479
1480      if (TNK == TNK_Non_template && MemberOfUnknownSpecialization &&
1481          ObjectType && IsTemplateArgumentList()) {
1482        // We have something like t->getAs<T>(), where getAs is a
1483        // member of an unknown specialization. However, this will only
1484        // parse correctly as a template, so suggest the keyword 'template'
1485        // before 'getAs' and treat this as a dependent template name.
1486        std::string Name;
1487        if (Id.getKind() == UnqualifiedId::IK_Identifier)
1488          Name = Id.Identifier->getName();
1489        else {
1490          Name = "operator ";
1491          if (Id.getKind() == UnqualifiedId::IK_OperatorFunctionId)
1492            Name += getOperatorSpelling(Id.OperatorFunctionId.Operator);
1493          else
1494            Name += Id.Identifier->getName();
1495        }
1496        Diag(Id.StartLocation, diag::err_missing_dependent_template_keyword)
1497          << Name
1498          << FixItHint::CreateInsertion(Id.StartLocation, "template ");
1499        TNK = Actions.ActOnDependentTemplateName(getCurScope(), TemplateKWLoc,
1500                                                 SS, Id, ObjectType,
1501                                                 EnteringContext, Template);
1502        if (TNK == TNK_Non_template)
1503          return true;
1504      }
1505    }
1506    break;
1507
1508  case UnqualifiedId::IK_ConstructorName: {
1509    UnqualifiedId TemplateName;
1510    bool MemberOfUnknownSpecialization;
1511    TemplateName.setIdentifier(Name, NameLoc);
1512    TNK = Actions.isTemplateName(getCurScope(), SS, TemplateKWLoc.isValid(),
1513                                 TemplateName, ObjectType,
1514                                 EnteringContext, Template,
1515                                 MemberOfUnknownSpecialization);
1516    break;
1517  }
1518
1519  case UnqualifiedId::IK_DestructorName: {
1520    UnqualifiedId TemplateName;
1521    bool MemberOfUnknownSpecialization;
1522    TemplateName.setIdentifier(Name, NameLoc);
1523    if (ObjectType) {
1524      TNK = Actions.ActOnDependentTemplateName(getCurScope(), TemplateKWLoc, SS,
1525                                               TemplateName, ObjectType,
1526                                               EnteringContext, Template);
1527      if (TNK == TNK_Non_template)
1528        return true;
1529    } else {
1530      TNK = Actions.isTemplateName(getCurScope(), SS, TemplateKWLoc.isValid(),
1531                                   TemplateName, ObjectType,
1532                                   EnteringContext, Template,
1533                                   MemberOfUnknownSpecialization);
1534
1535      if (TNK == TNK_Non_template && !Id.DestructorName.get()) {
1536        Diag(NameLoc, diag::err_destructor_template_id)
1537          << Name << SS.getRange();
1538        return true;
1539      }
1540    }
1541    break;
1542  }
1543
1544  default:
1545    return false;
1546  }
1547
1548  if (TNK == TNK_Non_template)
1549    return false;
1550
1551  // Parse the enclosed template argument list.
1552  SourceLocation LAngleLoc, RAngleLoc;
1553  TemplateArgList TemplateArgs;
1554  if (Tok.is(tok::less) &&
1555      ParseTemplateIdAfterTemplateName(Template, Id.StartLocation,
1556                                       SS, true, LAngleLoc,
1557                                       TemplateArgs,
1558                                       RAngleLoc))
1559    return true;
1560
1561  if (Id.getKind() == UnqualifiedId::IK_Identifier ||
1562      Id.getKind() == UnqualifiedId::IK_OperatorFunctionId ||
1563      Id.getKind() == UnqualifiedId::IK_LiteralOperatorId) {
1564    // Form a parsed representation of the template-id to be stored in the
1565    // UnqualifiedId.
1566    TemplateIdAnnotation *TemplateId
1567      = TemplateIdAnnotation::Allocate(TemplateArgs.size());
1568
1569    if (Id.getKind() == UnqualifiedId::IK_Identifier) {
1570      TemplateId->Name = Id.Identifier;
1571      TemplateId->Operator = OO_None;
1572      TemplateId->TemplateNameLoc = Id.StartLocation;
1573    } else {
1574      TemplateId->Name = 0;
1575      TemplateId->Operator = Id.OperatorFunctionId.Operator;
1576      TemplateId->TemplateNameLoc = Id.StartLocation;
1577    }
1578
1579    TemplateId->SS = SS;
1580    TemplateId->Template = Template;
1581    TemplateId->Kind = TNK;
1582    TemplateId->LAngleLoc = LAngleLoc;
1583    TemplateId->RAngleLoc = RAngleLoc;
1584    ParsedTemplateArgument *Args = TemplateId->getTemplateArgs();
1585    for (unsigned Arg = 0, ArgEnd = TemplateArgs.size();
1586         Arg != ArgEnd; ++Arg)
1587      Args[Arg] = TemplateArgs[Arg];
1588
1589    Id.setTemplateId(TemplateId);
1590    return false;
1591  }
1592
1593  // Bundle the template arguments together.
1594  ASTTemplateArgsPtr TemplateArgsPtr(Actions, TemplateArgs.data(),
1595                                     TemplateArgs.size());
1596
1597  // Constructor and destructor names.
1598  TypeResult Type
1599    = Actions.ActOnTemplateIdType(SS, Template, NameLoc,
1600                                  LAngleLoc, TemplateArgsPtr,
1601                                  RAngleLoc);
1602  if (Type.isInvalid())
1603    return true;
1604
1605  if (Id.getKind() == UnqualifiedId::IK_ConstructorName)
1606    Id.setConstructorName(Type.get(), NameLoc, RAngleLoc);
1607  else
1608    Id.setDestructorName(Id.StartLocation, Type.get(), RAngleLoc);
1609
1610  return false;
1611}
1612
1613/// \brief Parse an operator-function-id or conversion-function-id as part
1614/// of a C++ unqualified-id.
1615///
1616/// This routine is responsible only for parsing the operator-function-id or
1617/// conversion-function-id; it does not handle template arguments in any way.
1618///
1619/// \code
1620///       operator-function-id: [C++ 13.5]
1621///         'operator' operator
1622///
1623///       operator: one of
1624///            new   delete  new[]   delete[]
1625///            +     -    *  /    %  ^    &   |   ~
1626///            !     =    <  >    += -=   *=  /=  %=
1627///            ^=    &=   |= <<   >> >>= <<=  ==  !=
1628///            <=    >=   && ||   ++ --   ,   ->* ->
1629///            ()    []
1630///
1631///       conversion-function-id: [C++ 12.3.2]
1632///         operator conversion-type-id
1633///
1634///       conversion-type-id:
1635///         type-specifier-seq conversion-declarator[opt]
1636///
1637///       conversion-declarator:
1638///         ptr-operator conversion-declarator[opt]
1639/// \endcode
1640///
1641/// \param The nested-name-specifier that preceded this unqualified-id. If
1642/// non-empty, then we are parsing the unqualified-id of a qualified-id.
1643///
1644/// \param EnteringContext whether we are entering the scope of the
1645/// nested-name-specifier.
1646///
1647/// \param ObjectType if this unqualified-id occurs within a member access
1648/// expression, the type of the base object whose member is being accessed.
1649///
1650/// \param Result on a successful parse, contains the parsed unqualified-id.
1651///
1652/// \returns true if parsing fails, false otherwise.
1653bool Parser::ParseUnqualifiedIdOperator(CXXScopeSpec &SS, bool EnteringContext,
1654                                        ParsedType ObjectType,
1655                                        UnqualifiedId &Result) {
1656  assert(Tok.is(tok::kw_operator) && "Expected 'operator' keyword");
1657
1658  // Consume the 'operator' keyword.
1659  SourceLocation KeywordLoc = ConsumeToken();
1660
1661  // Determine what kind of operator name we have.
1662  unsigned SymbolIdx = 0;
1663  SourceLocation SymbolLocations[3];
1664  OverloadedOperatorKind Op = OO_None;
1665  switch (Tok.getKind()) {
1666    case tok::kw_new:
1667    case tok::kw_delete: {
1668      bool isNew = Tok.getKind() == tok::kw_new;
1669      // Consume the 'new' or 'delete'.
1670      SymbolLocations[SymbolIdx++] = ConsumeToken();
1671      if (Tok.is(tok::l_square)) {
1672        // Consume the '[' and ']'.
1673        BalancedDelimiterTracker T(*this, tok::l_square);
1674        T.consumeOpen();
1675        T.consumeClose();
1676        if (T.getCloseLocation().isInvalid())
1677          return true;
1678
1679        SymbolLocations[SymbolIdx++] = T.getOpenLocation();
1680        SymbolLocations[SymbolIdx++] = T.getCloseLocation();
1681        Op = isNew? OO_Array_New : OO_Array_Delete;
1682      } else {
1683        Op = isNew? OO_New : OO_Delete;
1684      }
1685      break;
1686    }
1687
1688#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
1689    case tok::Token:                                                     \
1690      SymbolLocations[SymbolIdx++] = ConsumeToken();                     \
1691      Op = OO_##Name;                                                    \
1692      break;
1693#define OVERLOADED_OPERATOR_MULTI(Name,Spelling,Unary,Binary,MemberOnly)
1694#include "clang/Basic/OperatorKinds.def"
1695
1696    case tok::l_paren: {
1697      // Consume the '(' and ')'.
1698      BalancedDelimiterTracker T(*this, tok::l_paren);
1699      T.consumeOpen();
1700      T.consumeClose();
1701      if (T.getCloseLocation().isInvalid())
1702        return true;
1703
1704      SymbolLocations[SymbolIdx++] = T.getOpenLocation();
1705      SymbolLocations[SymbolIdx++] = T.getCloseLocation();
1706      Op = OO_Call;
1707      break;
1708    }
1709
1710    case tok::l_square: {
1711      // Consume the '[' and ']'.
1712      BalancedDelimiterTracker T(*this, tok::l_square);
1713      T.consumeOpen();
1714      T.consumeClose();
1715      if (T.getCloseLocation().isInvalid())
1716        return true;
1717
1718      SymbolLocations[SymbolIdx++] = T.getOpenLocation();
1719      SymbolLocations[SymbolIdx++] = T.getCloseLocation();
1720      Op = OO_Subscript;
1721      break;
1722    }
1723
1724    case tok::code_completion: {
1725      // Code completion for the operator name.
1726      Actions.CodeCompleteOperatorName(getCurScope());
1727      cutOffParsing();
1728      // Don't try to parse any further.
1729      return true;
1730    }
1731
1732    default:
1733      break;
1734  }
1735
1736  if (Op != OO_None) {
1737    // We have parsed an operator-function-id.
1738    Result.setOperatorFunctionId(KeywordLoc, Op, SymbolLocations);
1739    return false;
1740  }
1741
1742  // Parse a literal-operator-id.
1743  //
1744  //   literal-operator-id: [C++0x 13.5.8]
1745  //     operator "" identifier
1746
1747  if (getLang().CPlusPlus0x && Tok.is(tok::string_literal)) {
1748    Diag(Tok.getLocation(), diag::warn_cxx98_compat_literal_operator);
1749    if (Tok.getLength() != 2)
1750      Diag(Tok.getLocation(), diag::err_operator_string_not_empty);
1751    ConsumeStringToken();
1752
1753    if (Tok.isNot(tok::identifier)) {
1754      Diag(Tok.getLocation(), diag::err_expected_ident);
1755      return true;
1756    }
1757
1758    IdentifierInfo *II = Tok.getIdentifierInfo();
1759    Result.setLiteralOperatorId(II, KeywordLoc, ConsumeToken());
1760    return false;
1761  }
1762
1763  // Parse a conversion-function-id.
1764  //
1765  //   conversion-function-id: [C++ 12.3.2]
1766  //     operator conversion-type-id
1767  //
1768  //   conversion-type-id:
1769  //     type-specifier-seq conversion-declarator[opt]
1770  //
1771  //   conversion-declarator:
1772  //     ptr-operator conversion-declarator[opt]
1773
1774  // Parse the type-specifier-seq.
1775  DeclSpec DS(AttrFactory);
1776  if (ParseCXXTypeSpecifierSeq(DS)) // FIXME: ObjectType?
1777    return true;
1778
1779  // Parse the conversion-declarator, which is merely a sequence of
1780  // ptr-operators.
1781  Declarator D(DS, Declarator::TypeNameContext);
1782  ParseDeclaratorInternal(D, /*DirectDeclParser=*/0);
1783
1784  // Finish up the type.
1785  TypeResult Ty = Actions.ActOnTypeName(getCurScope(), D);
1786  if (Ty.isInvalid())
1787    return true;
1788
1789  // Note that this is a conversion-function-id.
1790  Result.setConversionFunctionId(KeywordLoc, Ty.get(),
1791                                 D.getSourceRange().getEnd());
1792  return false;
1793}
1794
1795/// \brief Parse a C++ unqualified-id (or a C identifier), which describes the
1796/// name of an entity.
1797///
1798/// \code
1799///       unqualified-id: [C++ expr.prim.general]
1800///         identifier
1801///         operator-function-id
1802///         conversion-function-id
1803/// [C++0x] literal-operator-id [TODO]
1804///         ~ class-name
1805///         template-id
1806///
1807/// \endcode
1808///
1809/// \param The nested-name-specifier that preceded this unqualified-id. If
1810/// non-empty, then we are parsing the unqualified-id of a qualified-id.
1811///
1812/// \param EnteringContext whether we are entering the scope of the
1813/// nested-name-specifier.
1814///
1815/// \param AllowDestructorName whether we allow parsing of a destructor name.
1816///
1817/// \param AllowConstructorName whether we allow parsing a constructor name.
1818///
1819/// \param ObjectType if this unqualified-id occurs within a member access
1820/// expression, the type of the base object whose member is being accessed.
1821///
1822/// \param Result on a successful parse, contains the parsed unqualified-id.
1823///
1824/// \returns true if parsing fails, false otherwise.
1825bool Parser::ParseUnqualifiedId(CXXScopeSpec &SS, bool EnteringContext,
1826                                bool AllowDestructorName,
1827                                bool AllowConstructorName,
1828                                ParsedType ObjectType,
1829                                UnqualifiedId &Result) {
1830
1831  // Handle 'A::template B'. This is for template-ids which have not
1832  // already been annotated by ParseOptionalCXXScopeSpecifier().
1833  bool TemplateSpecified = false;
1834  SourceLocation TemplateKWLoc;
1835  if (getLang().CPlusPlus && Tok.is(tok::kw_template) &&
1836      (ObjectType || SS.isSet())) {
1837    TemplateSpecified = true;
1838    TemplateKWLoc = ConsumeToken();
1839  }
1840
1841  // unqualified-id:
1842  //   identifier
1843  //   template-id (when it hasn't already been annotated)
1844  if (Tok.is(tok::identifier)) {
1845    // Consume the identifier.
1846    IdentifierInfo *Id = Tok.getIdentifierInfo();
1847    SourceLocation IdLoc = ConsumeToken();
1848
1849    if (!getLang().CPlusPlus) {
1850      // If we're not in C++, only identifiers matter. Record the
1851      // identifier and return.
1852      Result.setIdentifier(Id, IdLoc);
1853      return false;
1854    }
1855
1856    if (AllowConstructorName &&
1857        Actions.isCurrentClassName(*Id, getCurScope(), &SS)) {
1858      // We have parsed a constructor name.
1859      Result.setConstructorName(Actions.getTypeName(*Id, IdLoc, getCurScope(),
1860                                                    &SS, false, false,
1861                                                    ParsedType(),
1862                                            /*NonTrivialTypeSourceInfo=*/true),
1863                                IdLoc, IdLoc);
1864    } else {
1865      // We have parsed an identifier.
1866      Result.setIdentifier(Id, IdLoc);
1867    }
1868
1869    // If the next token is a '<', we may have a template.
1870    if (TemplateSpecified || Tok.is(tok::less))
1871      return ParseUnqualifiedIdTemplateId(SS, Id, IdLoc, EnteringContext,
1872                                          ObjectType, Result,
1873                                          TemplateSpecified, TemplateKWLoc);
1874
1875    return false;
1876  }
1877
1878  // unqualified-id:
1879  //   template-id (already parsed and annotated)
1880  if (Tok.is(tok::annot_template_id)) {
1881    TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
1882
1883    // If the template-name names the current class, then this is a constructor
1884    if (AllowConstructorName && TemplateId->Name &&
1885        Actions.isCurrentClassName(*TemplateId->Name, getCurScope(), &SS)) {
1886      if (SS.isSet()) {
1887        // C++ [class.qual]p2 specifies that a qualified template-name
1888        // is taken as the constructor name where a constructor can be
1889        // declared. Thus, the template arguments are extraneous, so
1890        // complain about them and remove them entirely.
1891        Diag(TemplateId->TemplateNameLoc,
1892             diag::err_out_of_line_constructor_template_id)
1893          << TemplateId->Name
1894          << FixItHint::CreateRemoval(
1895                    SourceRange(TemplateId->LAngleLoc, TemplateId->RAngleLoc));
1896        Result.setConstructorName(Actions.getTypeName(*TemplateId->Name,
1897                                                  TemplateId->TemplateNameLoc,
1898                                                      getCurScope(),
1899                                                      &SS, false, false,
1900                                                      ParsedType(),
1901                                            /*NontrivialTypeSourceInfo=*/true),
1902                                  TemplateId->TemplateNameLoc,
1903                                  TemplateId->RAngleLoc);
1904        ConsumeToken();
1905        return false;
1906      }
1907
1908      Result.setConstructorTemplateId(TemplateId);
1909      ConsumeToken();
1910      return false;
1911    }
1912
1913    // We have already parsed a template-id; consume the annotation token as
1914    // our unqualified-id.
1915    Result.setTemplateId(TemplateId);
1916    ConsumeToken();
1917    return false;
1918  }
1919
1920  // unqualified-id:
1921  //   operator-function-id
1922  //   conversion-function-id
1923  if (Tok.is(tok::kw_operator)) {
1924    if (ParseUnqualifiedIdOperator(SS, EnteringContext, ObjectType, Result))
1925      return true;
1926
1927    // If we have an operator-function-id or a literal-operator-id and the next
1928    // token is a '<', we may have a
1929    //
1930    //   template-id:
1931    //     operator-function-id < template-argument-list[opt] >
1932    if ((Result.getKind() == UnqualifiedId::IK_OperatorFunctionId ||
1933         Result.getKind() == UnqualifiedId::IK_LiteralOperatorId) &&
1934        (TemplateSpecified || Tok.is(tok::less)))
1935      return ParseUnqualifiedIdTemplateId(SS, 0, SourceLocation(),
1936                                          EnteringContext, ObjectType,
1937                                          Result,
1938                                          TemplateSpecified, TemplateKWLoc);
1939
1940    return false;
1941  }
1942
1943  if (getLang().CPlusPlus &&
1944      (AllowDestructorName || SS.isSet()) && Tok.is(tok::tilde)) {
1945    // C++ [expr.unary.op]p10:
1946    //   There is an ambiguity in the unary-expression ~X(), where X is a
1947    //   class-name. The ambiguity is resolved in favor of treating ~ as a
1948    //    unary complement rather than treating ~X as referring to a destructor.
1949
1950    // Parse the '~'.
1951    SourceLocation TildeLoc = ConsumeToken();
1952
1953    // Parse the class-name.
1954    if (Tok.isNot(tok::identifier)) {
1955      Diag(Tok, diag::err_destructor_tilde_identifier);
1956      return true;
1957    }
1958
1959    // Parse the class-name (or template-name in a simple-template-id).
1960    IdentifierInfo *ClassName = Tok.getIdentifierInfo();
1961    SourceLocation ClassNameLoc = ConsumeToken();
1962
1963    if (TemplateSpecified || Tok.is(tok::less)) {
1964      Result.setDestructorName(TildeLoc, ParsedType(), ClassNameLoc);
1965      return ParseUnqualifiedIdTemplateId(SS, ClassName, ClassNameLoc,
1966                                          EnteringContext, ObjectType, Result,
1967                                          TemplateSpecified, TemplateKWLoc);
1968    }
1969
1970    // Note that this is a destructor name.
1971    ParsedType Ty = Actions.getDestructorName(TildeLoc, *ClassName,
1972                                              ClassNameLoc, getCurScope(),
1973                                              SS, ObjectType,
1974                                              EnteringContext);
1975    if (!Ty)
1976      return true;
1977
1978    Result.setDestructorName(TildeLoc, Ty, ClassNameLoc);
1979    return false;
1980  }
1981
1982  Diag(Tok, diag::err_expected_unqualified_id)
1983    << getLang().CPlusPlus;
1984  return true;
1985}
1986
1987/// ParseCXXNewExpression - Parse a C++ new-expression. New is used to allocate
1988/// memory in a typesafe manner and call constructors.
1989///
1990/// This method is called to parse the new expression after the optional :: has
1991/// been already parsed.  If the :: was present, "UseGlobal" is true and "Start"
1992/// is its location.  Otherwise, "Start" is the location of the 'new' token.
1993///
1994///        new-expression:
1995///                   '::'[opt] 'new' new-placement[opt] new-type-id
1996///                                     new-initializer[opt]
1997///                   '::'[opt] 'new' new-placement[opt] '(' type-id ')'
1998///                                     new-initializer[opt]
1999///
2000///        new-placement:
2001///                   '(' expression-list ')'
2002///
2003///        new-type-id:
2004///                   type-specifier-seq new-declarator[opt]
2005/// [GNU]             attributes type-specifier-seq new-declarator[opt]
2006///
2007///        new-declarator:
2008///                   ptr-operator new-declarator[opt]
2009///                   direct-new-declarator
2010///
2011///        new-initializer:
2012///                   '(' expression-list[opt] ')'
2013/// [C++0x]           braced-init-list
2014///
2015ExprResult
2016Parser::ParseCXXNewExpression(bool UseGlobal, SourceLocation Start) {
2017  assert(Tok.is(tok::kw_new) && "expected 'new' token");
2018  ConsumeToken();   // Consume 'new'
2019
2020  // A '(' now can be a new-placement or the '(' wrapping the type-id in the
2021  // second form of new-expression. It can't be a new-type-id.
2022
2023  ExprVector PlacementArgs(Actions);
2024  SourceLocation PlacementLParen, PlacementRParen;
2025
2026  SourceRange TypeIdParens;
2027  DeclSpec DS(AttrFactory);
2028  Declarator DeclaratorInfo(DS, Declarator::CXXNewContext);
2029  if (Tok.is(tok::l_paren)) {
2030    // If it turns out to be a placement, we change the type location.
2031    BalancedDelimiterTracker T(*this, tok::l_paren);
2032    T.consumeOpen();
2033    PlacementLParen = T.getOpenLocation();
2034    if (ParseExpressionListOrTypeId(PlacementArgs, DeclaratorInfo)) {
2035      SkipUntil(tok::semi, /*StopAtSemi=*/true, /*DontConsume=*/true);
2036      return ExprError();
2037    }
2038
2039    T.consumeClose();
2040    PlacementRParen = T.getCloseLocation();
2041    if (PlacementRParen.isInvalid()) {
2042      SkipUntil(tok::semi, /*StopAtSemi=*/true, /*DontConsume=*/true);
2043      return ExprError();
2044    }
2045
2046    if (PlacementArgs.empty()) {
2047      // Reset the placement locations. There was no placement.
2048      TypeIdParens = T.getRange();
2049      PlacementLParen = PlacementRParen = SourceLocation();
2050    } else {
2051      // We still need the type.
2052      if (Tok.is(tok::l_paren)) {
2053        BalancedDelimiterTracker T(*this, tok::l_paren);
2054        T.consumeOpen();
2055        MaybeParseGNUAttributes(DeclaratorInfo);
2056        ParseSpecifierQualifierList(DS);
2057        DeclaratorInfo.SetSourceRange(DS.getSourceRange());
2058        ParseDeclarator(DeclaratorInfo);
2059        T.consumeClose();
2060        TypeIdParens = T.getRange();
2061      } else {
2062        MaybeParseGNUAttributes(DeclaratorInfo);
2063        if (ParseCXXTypeSpecifierSeq(DS))
2064          DeclaratorInfo.setInvalidType(true);
2065        else {
2066          DeclaratorInfo.SetSourceRange(DS.getSourceRange());
2067          ParseDeclaratorInternal(DeclaratorInfo,
2068                                  &Parser::ParseDirectNewDeclarator);
2069        }
2070      }
2071    }
2072  } else {
2073    // A new-type-id is a simplified type-id, where essentially the
2074    // direct-declarator is replaced by a direct-new-declarator.
2075    MaybeParseGNUAttributes(DeclaratorInfo);
2076    if (ParseCXXTypeSpecifierSeq(DS))
2077      DeclaratorInfo.setInvalidType(true);
2078    else {
2079      DeclaratorInfo.SetSourceRange(DS.getSourceRange());
2080      ParseDeclaratorInternal(DeclaratorInfo,
2081                              &Parser::ParseDirectNewDeclarator);
2082    }
2083  }
2084  if (DeclaratorInfo.isInvalidType()) {
2085    SkipUntil(tok::semi, /*StopAtSemi=*/true, /*DontConsume=*/true);
2086    return ExprError();
2087  }
2088
2089  ExprVector ConstructorArgs(Actions);
2090  SourceLocation ConstructorLParen, ConstructorRParen;
2091
2092  if (Tok.is(tok::l_paren)) {
2093    BalancedDelimiterTracker T(*this, tok::l_paren);
2094    T.consumeOpen();
2095    ConstructorLParen = T.getOpenLocation();
2096    if (Tok.isNot(tok::r_paren)) {
2097      CommaLocsTy CommaLocs;
2098      if (ParseExpressionList(ConstructorArgs, CommaLocs)) {
2099        SkipUntil(tok::semi, /*StopAtSemi=*/true, /*DontConsume=*/true);
2100        return ExprError();
2101      }
2102    }
2103    T.consumeClose();
2104    ConstructorRParen = T.getCloseLocation();
2105    if (ConstructorRParen.isInvalid()) {
2106      SkipUntil(tok::semi, /*StopAtSemi=*/true, /*DontConsume=*/true);
2107      return ExprError();
2108    }
2109  } else if (Tok.is(tok::l_brace) && getLang().CPlusPlus0x) {
2110    Diag(Tok.getLocation(),
2111         diag::warn_cxx98_compat_generalized_initializer_lists);
2112    // FIXME: Have to communicate the init-list to ActOnCXXNew.
2113    ParseBraceInitializer();
2114  }
2115
2116  return Actions.ActOnCXXNew(Start, UseGlobal, PlacementLParen,
2117                             move_arg(PlacementArgs), PlacementRParen,
2118                             TypeIdParens, DeclaratorInfo, ConstructorLParen,
2119                             move_arg(ConstructorArgs), ConstructorRParen);
2120}
2121
2122/// ParseDirectNewDeclarator - Parses a direct-new-declarator. Intended to be
2123/// passed to ParseDeclaratorInternal.
2124///
2125///        direct-new-declarator:
2126///                   '[' expression ']'
2127///                   direct-new-declarator '[' constant-expression ']'
2128///
2129void Parser::ParseDirectNewDeclarator(Declarator &D) {
2130  // Parse the array dimensions.
2131  bool first = true;
2132  while (Tok.is(tok::l_square)) {
2133    BalancedDelimiterTracker T(*this, tok::l_square);
2134    T.consumeOpen();
2135
2136    ExprResult Size(first ? ParseExpression()
2137                                : ParseConstantExpression());
2138    if (Size.isInvalid()) {
2139      // Recover
2140      SkipUntil(tok::r_square);
2141      return;
2142    }
2143    first = false;
2144
2145    T.consumeClose();
2146
2147    ParsedAttributes attrs(AttrFactory);
2148    D.AddTypeInfo(DeclaratorChunk::getArray(0,
2149                                            /*static=*/false, /*star=*/false,
2150                                            Size.release(),
2151                                            T.getOpenLocation(),
2152                                            T.getCloseLocation()),
2153                  attrs, T.getCloseLocation());
2154
2155    if (T.getCloseLocation().isInvalid())
2156      return;
2157  }
2158}
2159
2160/// ParseExpressionListOrTypeId - Parse either an expression-list or a type-id.
2161/// This ambiguity appears in the syntax of the C++ new operator.
2162///
2163///        new-expression:
2164///                   '::'[opt] 'new' new-placement[opt] '(' type-id ')'
2165///                                     new-initializer[opt]
2166///
2167///        new-placement:
2168///                   '(' expression-list ')'
2169///
2170bool Parser::ParseExpressionListOrTypeId(
2171                                   SmallVectorImpl<Expr*> &PlacementArgs,
2172                                         Declarator &D) {
2173  // The '(' was already consumed.
2174  if (isTypeIdInParens()) {
2175    ParseSpecifierQualifierList(D.getMutableDeclSpec());
2176    D.SetSourceRange(D.getDeclSpec().getSourceRange());
2177    ParseDeclarator(D);
2178    return D.isInvalidType();
2179  }
2180
2181  // It's not a type, it has to be an expression list.
2182  // Discard the comma locations - ActOnCXXNew has enough parameters.
2183  CommaLocsTy CommaLocs;
2184  return ParseExpressionList(PlacementArgs, CommaLocs);
2185}
2186
2187/// ParseCXXDeleteExpression - Parse a C++ delete-expression. Delete is used
2188/// to free memory allocated by new.
2189///
2190/// This method is called to parse the 'delete' expression after the optional
2191/// '::' has been already parsed.  If the '::' was present, "UseGlobal" is true
2192/// and "Start" is its location.  Otherwise, "Start" is the location of the
2193/// 'delete' token.
2194///
2195///        delete-expression:
2196///                   '::'[opt] 'delete' cast-expression
2197///                   '::'[opt] 'delete' '[' ']' cast-expression
2198ExprResult
2199Parser::ParseCXXDeleteExpression(bool UseGlobal, SourceLocation Start) {
2200  assert(Tok.is(tok::kw_delete) && "Expected 'delete' keyword");
2201  ConsumeToken(); // Consume 'delete'
2202
2203  // Array delete?
2204  bool ArrayDelete = false;
2205  if (Tok.is(tok::l_square)) {
2206    ArrayDelete = true;
2207    BalancedDelimiterTracker T(*this, tok::l_square);
2208
2209    T.consumeOpen();
2210    T.consumeClose();
2211    if (T.getCloseLocation().isInvalid())
2212      return ExprError();
2213  }
2214
2215  ExprResult Operand(ParseCastExpression(false));
2216  if (Operand.isInvalid())
2217    return move(Operand);
2218
2219  return Actions.ActOnCXXDelete(Start, UseGlobal, ArrayDelete, Operand.take());
2220}
2221
2222static UnaryTypeTrait UnaryTypeTraitFromTokKind(tok::TokenKind kind) {
2223  switch(kind) {
2224  default: llvm_unreachable("Not a known unary type trait.");
2225  case tok::kw___has_nothrow_assign:      return UTT_HasNothrowAssign;
2226  case tok::kw___has_nothrow_constructor: return UTT_HasNothrowConstructor;
2227  case tok::kw___has_nothrow_copy:           return UTT_HasNothrowCopy;
2228  case tok::kw___has_trivial_assign:      return UTT_HasTrivialAssign;
2229  case tok::kw___has_trivial_constructor:
2230                                    return UTT_HasTrivialDefaultConstructor;
2231  case tok::kw___has_trivial_copy:           return UTT_HasTrivialCopy;
2232  case tok::kw___has_trivial_destructor:  return UTT_HasTrivialDestructor;
2233  case tok::kw___has_virtual_destructor:  return UTT_HasVirtualDestructor;
2234  case tok::kw___is_abstract:             return UTT_IsAbstract;
2235  case tok::kw___is_arithmetic:              return UTT_IsArithmetic;
2236  case tok::kw___is_array:                   return UTT_IsArray;
2237  case tok::kw___is_class:                return UTT_IsClass;
2238  case tok::kw___is_complete_type:           return UTT_IsCompleteType;
2239  case tok::kw___is_compound:                return UTT_IsCompound;
2240  case tok::kw___is_const:                   return UTT_IsConst;
2241  case tok::kw___is_empty:                return UTT_IsEmpty;
2242  case tok::kw___is_enum:                 return UTT_IsEnum;
2243  case tok::kw___is_floating_point:          return UTT_IsFloatingPoint;
2244  case tok::kw___is_function:                return UTT_IsFunction;
2245  case tok::kw___is_fundamental:             return UTT_IsFundamental;
2246  case tok::kw___is_integral:                return UTT_IsIntegral;
2247  case tok::kw___is_lvalue_reference:        return UTT_IsLvalueReference;
2248  case tok::kw___is_member_function_pointer: return UTT_IsMemberFunctionPointer;
2249  case tok::kw___is_member_object_pointer:   return UTT_IsMemberObjectPointer;
2250  case tok::kw___is_member_pointer:          return UTT_IsMemberPointer;
2251  case tok::kw___is_object:                  return UTT_IsObject;
2252  case tok::kw___is_literal:              return UTT_IsLiteral;
2253  case tok::kw___is_literal_type:         return UTT_IsLiteral;
2254  case tok::kw___is_pod:                  return UTT_IsPOD;
2255  case tok::kw___is_pointer:                 return UTT_IsPointer;
2256  case tok::kw___is_polymorphic:          return UTT_IsPolymorphic;
2257  case tok::kw___is_reference:               return UTT_IsReference;
2258  case tok::kw___is_rvalue_reference:        return UTT_IsRvalueReference;
2259  case tok::kw___is_scalar:                  return UTT_IsScalar;
2260  case tok::kw___is_signed:                  return UTT_IsSigned;
2261  case tok::kw___is_standard_layout:         return UTT_IsStandardLayout;
2262  case tok::kw___is_trivial:                 return UTT_IsTrivial;
2263  case tok::kw___is_trivially_copyable:      return UTT_IsTriviallyCopyable;
2264  case tok::kw___is_union:                return UTT_IsUnion;
2265  case tok::kw___is_unsigned:                return UTT_IsUnsigned;
2266  case tok::kw___is_void:                    return UTT_IsVoid;
2267  case tok::kw___is_volatile:                return UTT_IsVolatile;
2268  }
2269}
2270
2271static BinaryTypeTrait BinaryTypeTraitFromTokKind(tok::TokenKind kind) {
2272  switch(kind) {
2273  default: llvm_unreachable("Not a known binary type trait");
2274  case tok::kw___is_base_of:                 return BTT_IsBaseOf;
2275  case tok::kw___is_convertible:             return BTT_IsConvertible;
2276  case tok::kw___is_same:                    return BTT_IsSame;
2277  case tok::kw___builtin_types_compatible_p: return BTT_TypeCompatible;
2278  case tok::kw___is_convertible_to:          return BTT_IsConvertibleTo;
2279  }
2280}
2281
2282static ArrayTypeTrait ArrayTypeTraitFromTokKind(tok::TokenKind kind) {
2283  switch(kind) {
2284  default: llvm_unreachable("Not a known binary type trait");
2285  case tok::kw___array_rank:                 return ATT_ArrayRank;
2286  case tok::kw___array_extent:               return ATT_ArrayExtent;
2287  }
2288}
2289
2290static ExpressionTrait ExpressionTraitFromTokKind(tok::TokenKind kind) {
2291  switch(kind) {
2292  default: llvm_unreachable("Not a known unary expression trait.");
2293  case tok::kw___is_lvalue_expr:             return ET_IsLValueExpr;
2294  case tok::kw___is_rvalue_expr:             return ET_IsRValueExpr;
2295  }
2296}
2297
2298/// ParseUnaryTypeTrait - Parse the built-in unary type-trait
2299/// pseudo-functions that allow implementation of the TR1/C++0x type traits
2300/// templates.
2301///
2302///       primary-expression:
2303/// [GNU]             unary-type-trait '(' type-id ')'
2304///
2305ExprResult Parser::ParseUnaryTypeTrait() {
2306  UnaryTypeTrait UTT = UnaryTypeTraitFromTokKind(Tok.getKind());
2307  SourceLocation Loc = ConsumeToken();
2308
2309  BalancedDelimiterTracker T(*this, tok::l_paren);
2310  if (T.expectAndConsume(diag::err_expected_lparen))
2311    return ExprError();
2312
2313  // FIXME: Error reporting absolutely sucks! If the this fails to parse a type
2314  // there will be cryptic errors about mismatched parentheses and missing
2315  // specifiers.
2316  TypeResult Ty = ParseTypeName();
2317
2318  T.consumeClose();
2319
2320  if (Ty.isInvalid())
2321    return ExprError();
2322
2323  return Actions.ActOnUnaryTypeTrait(UTT, Loc, Ty.get(), T.getCloseLocation());
2324}
2325
2326/// ParseBinaryTypeTrait - Parse the built-in binary type-trait
2327/// pseudo-functions that allow implementation of the TR1/C++0x type traits
2328/// templates.
2329///
2330///       primary-expression:
2331/// [GNU]             binary-type-trait '(' type-id ',' type-id ')'
2332///
2333ExprResult Parser::ParseBinaryTypeTrait() {
2334  BinaryTypeTrait BTT = BinaryTypeTraitFromTokKind(Tok.getKind());
2335  SourceLocation Loc = ConsumeToken();
2336
2337  BalancedDelimiterTracker T(*this, tok::l_paren);
2338  if (T.expectAndConsume(diag::err_expected_lparen))
2339    return ExprError();
2340
2341  TypeResult LhsTy = ParseTypeName();
2342  if (LhsTy.isInvalid()) {
2343    SkipUntil(tok::r_paren);
2344    return ExprError();
2345  }
2346
2347  if (ExpectAndConsume(tok::comma, diag::err_expected_comma)) {
2348    SkipUntil(tok::r_paren);
2349    return ExprError();
2350  }
2351
2352  TypeResult RhsTy = ParseTypeName();
2353  if (RhsTy.isInvalid()) {
2354    SkipUntil(tok::r_paren);
2355    return ExprError();
2356  }
2357
2358  T.consumeClose();
2359
2360  return Actions.ActOnBinaryTypeTrait(BTT, Loc, LhsTy.get(), RhsTy.get(),
2361                                      T.getCloseLocation());
2362}
2363
2364/// ParseArrayTypeTrait - Parse the built-in array type-trait
2365/// pseudo-functions.
2366///
2367///       primary-expression:
2368/// [Embarcadero]     '__array_rank' '(' type-id ')'
2369/// [Embarcadero]     '__array_extent' '(' type-id ',' expression ')'
2370///
2371ExprResult Parser::ParseArrayTypeTrait() {
2372  ArrayTypeTrait ATT = ArrayTypeTraitFromTokKind(Tok.getKind());
2373  SourceLocation Loc = ConsumeToken();
2374
2375  BalancedDelimiterTracker T(*this, tok::l_paren);
2376  if (T.expectAndConsume(diag::err_expected_lparen))
2377    return ExprError();
2378
2379  TypeResult Ty = ParseTypeName();
2380  if (Ty.isInvalid()) {
2381    SkipUntil(tok::comma);
2382    SkipUntil(tok::r_paren);
2383    return ExprError();
2384  }
2385
2386  switch (ATT) {
2387  case ATT_ArrayRank: {
2388    T.consumeClose();
2389    return Actions.ActOnArrayTypeTrait(ATT, Loc, Ty.get(), NULL,
2390                                       T.getCloseLocation());
2391  }
2392  case ATT_ArrayExtent: {
2393    if (ExpectAndConsume(tok::comma, diag::err_expected_comma)) {
2394      SkipUntil(tok::r_paren);
2395      return ExprError();
2396    }
2397
2398    ExprResult DimExpr = ParseExpression();
2399    T.consumeClose();
2400
2401    return Actions.ActOnArrayTypeTrait(ATT, Loc, Ty.get(), DimExpr.get(),
2402                                       T.getCloseLocation());
2403  }
2404  default:
2405    break;
2406  }
2407  return ExprError();
2408}
2409
2410/// ParseExpressionTrait - Parse built-in expression-trait
2411/// pseudo-functions like __is_lvalue_expr( xxx ).
2412///
2413///       primary-expression:
2414/// [Embarcadero]     expression-trait '(' expression ')'
2415///
2416ExprResult Parser::ParseExpressionTrait() {
2417  ExpressionTrait ET = ExpressionTraitFromTokKind(Tok.getKind());
2418  SourceLocation Loc = ConsumeToken();
2419
2420  BalancedDelimiterTracker T(*this, tok::l_paren);
2421  if (T.expectAndConsume(diag::err_expected_lparen))
2422    return ExprError();
2423
2424  ExprResult Expr = ParseExpression();
2425
2426  T.consumeClose();
2427
2428  return Actions.ActOnExpressionTrait(ET, Loc, Expr.get(),
2429                                      T.getCloseLocation());
2430}
2431
2432
2433/// ParseCXXAmbiguousParenExpression - We have parsed the left paren of a
2434/// parenthesized ambiguous type-id. This uses tentative parsing to disambiguate
2435/// based on the context past the parens.
2436ExprResult
2437Parser::ParseCXXAmbiguousParenExpression(ParenParseOption &ExprType,
2438                                         ParsedType &CastTy,
2439                                         BalancedDelimiterTracker &Tracker) {
2440  assert(getLang().CPlusPlus && "Should only be called for C++!");
2441  assert(ExprType == CastExpr && "Compound literals are not ambiguous!");
2442  assert(isTypeIdInParens() && "Not a type-id!");
2443
2444  ExprResult Result(true);
2445  CastTy = ParsedType();
2446
2447  // We need to disambiguate a very ugly part of the C++ syntax:
2448  //
2449  // (T())x;  - type-id
2450  // (T())*x; - type-id
2451  // (T())/x; - expression
2452  // (T());   - expression
2453  //
2454  // The bad news is that we cannot use the specialized tentative parser, since
2455  // it can only verify that the thing inside the parens can be parsed as
2456  // type-id, it is not useful for determining the context past the parens.
2457  //
2458  // The good news is that the parser can disambiguate this part without
2459  // making any unnecessary Action calls.
2460  //
2461  // It uses a scheme similar to parsing inline methods. The parenthesized
2462  // tokens are cached, the context that follows is determined (possibly by
2463  // parsing a cast-expression), and then we re-introduce the cached tokens
2464  // into the token stream and parse them appropriately.
2465
2466  ParenParseOption ParseAs;
2467  CachedTokens Toks;
2468
2469  // Store the tokens of the parentheses. We will parse them after we determine
2470  // the context that follows them.
2471  if (!ConsumeAndStoreUntil(tok::r_paren, Toks)) {
2472    // We didn't find the ')' we expected.
2473    Tracker.consumeClose();
2474    return ExprError();
2475  }
2476
2477  if (Tok.is(tok::l_brace)) {
2478    ParseAs = CompoundLiteral;
2479  } else {
2480    bool NotCastExpr;
2481    // FIXME: Special-case ++ and --: "(S())++;" is not a cast-expression
2482    if (Tok.is(tok::l_paren) && NextToken().is(tok::r_paren)) {
2483      NotCastExpr = true;
2484    } else {
2485      // Try parsing the cast-expression that may follow.
2486      // If it is not a cast-expression, NotCastExpr will be true and no token
2487      // will be consumed.
2488      Result = ParseCastExpression(false/*isUnaryExpression*/,
2489                                   false/*isAddressofOperand*/,
2490                                   NotCastExpr,
2491                                   // type-id has priority.
2492                                   true/*isTypeCast*/);
2493    }
2494
2495    // If we parsed a cast-expression, it's really a type-id, otherwise it's
2496    // an expression.
2497    ParseAs = NotCastExpr ? SimpleExpr : CastExpr;
2498  }
2499
2500  // The current token should go after the cached tokens.
2501  Toks.push_back(Tok);
2502  // Re-enter the stored parenthesized tokens into the token stream, so we may
2503  // parse them now.
2504  PP.EnterTokenStream(Toks.data(), Toks.size(),
2505                      true/*DisableMacroExpansion*/, false/*OwnsTokens*/);
2506  // Drop the current token and bring the first cached one. It's the same token
2507  // as when we entered this function.
2508  ConsumeAnyToken();
2509
2510  if (ParseAs >= CompoundLiteral) {
2511    // Parse the type declarator.
2512    DeclSpec DS(AttrFactory);
2513    ParseSpecifierQualifierList(DS);
2514    Declarator DeclaratorInfo(DS, Declarator::TypeNameContext);
2515    ParseDeclarator(DeclaratorInfo);
2516
2517    // Match the ')'.
2518    Tracker.consumeClose();
2519
2520    if (ParseAs == CompoundLiteral) {
2521      ExprType = CompoundLiteral;
2522      TypeResult Ty = ParseTypeName();
2523       return ParseCompoundLiteralExpression(Ty.get(),
2524                                            Tracker.getOpenLocation(),
2525                                            Tracker.getCloseLocation());
2526    }
2527
2528    // We parsed '(' type-id ')' and the thing after it wasn't a '{'.
2529    assert(ParseAs == CastExpr);
2530
2531    if (DeclaratorInfo.isInvalidType())
2532      return ExprError();
2533
2534    // Result is what ParseCastExpression returned earlier.
2535    if (!Result.isInvalid())
2536      Result = Actions.ActOnCastExpr(getCurScope(), Tracker.getOpenLocation(),
2537                                    DeclaratorInfo, CastTy,
2538                                    Tracker.getCloseLocation(), Result.take());
2539    return move(Result);
2540  }
2541
2542  // Not a compound literal, and not followed by a cast-expression.
2543  assert(ParseAs == SimpleExpr);
2544
2545  ExprType = SimpleExpr;
2546  Result = ParseExpression();
2547  if (!Result.isInvalid() && Tok.is(tok::r_paren))
2548    Result = Actions.ActOnParenExpr(Tracker.getOpenLocation(),
2549                                    Tok.getLocation(), Result.take());
2550
2551  // Match the ')'.
2552  if (Result.isInvalid()) {
2553    SkipUntil(tok::r_paren);
2554    return ExprError();
2555  }
2556
2557  Tracker.consumeClose();
2558  return move(Result);
2559}
2560