ParseTemplate.cpp revision 80ad52f327b532bded5c5b0ee38779d841c6cd35 
1//===--- ParseTemplate.cpp - Template 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 parsing of C++ templates.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Parse/Parser.h"
15#include "RAIIObjectsForParser.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/AST/DeclTemplate.h"
18#include "clang/Parse/ParseDiagnostic.h"
19#include "clang/Sema/DeclSpec.h"
20#include "clang/Sema/ParsedTemplate.h"
21#include "clang/Sema/Scope.h"
22using namespace clang;
23
24/// \brief Parse a template declaration, explicit instantiation, or
25/// explicit specialization.
26Decl *
27Parser::ParseDeclarationStartingWithTemplate(unsigned Context,
28                                             SourceLocation &DeclEnd,
29                                             AccessSpecifier AS,
30                                             AttributeList *AccessAttrs) {
31  ObjCDeclContextSwitch ObjCDC(*this);
32
33  if (Tok.is(tok::kw_template) && NextToken().isNot(tok::less)) {
34    return ParseExplicitInstantiation(Context,
35                                      SourceLocation(), ConsumeToken(),
36                                      DeclEnd, AS);
37  }
38  return ParseTemplateDeclarationOrSpecialization(Context, DeclEnd, AS,
39                                                  AccessAttrs);
40}
41
42/// \brief RAII class that manages the template parameter depth.
43namespace {
44  class TemplateParameterDepthCounter {
45    unsigned &Depth;
46    unsigned AddedLevels;
47
48  public:
49    explicit TemplateParameterDepthCounter(unsigned &Depth)
50      : Depth(Depth), AddedLevels(0) { }
51
52    ~TemplateParameterDepthCounter() {
53      Depth -= AddedLevels;
54    }
55
56    void operator++() {
57      ++Depth;
58      ++AddedLevels;
59    }
60
61    operator unsigned() const { return Depth; }
62  };
63}
64
65/// \brief Parse a template declaration or an explicit specialization.
66///
67/// Template declarations include one or more template parameter lists
68/// and either the function or class template declaration. Explicit
69/// specializations contain one or more 'template < >' prefixes
70/// followed by a (possibly templated) declaration. Since the
71/// syntactic form of both features is nearly identical, we parse all
72/// of the template headers together and let semantic analysis sort
73/// the declarations from the explicit specializations.
74///
75///       template-declaration: [C++ temp]
76///         'export'[opt] 'template' '<' template-parameter-list '>' declaration
77///
78///       explicit-specialization: [ C++ temp.expl.spec]
79///         'template' '<' '>' declaration
80Decl *
81Parser::ParseTemplateDeclarationOrSpecialization(unsigned Context,
82                                                 SourceLocation &DeclEnd,
83                                                 AccessSpecifier AS,
84                                                 AttributeList *AccessAttrs) {
85  assert((Tok.is(tok::kw_export) || Tok.is(tok::kw_template)) &&
86         "Token does not start a template declaration.");
87
88  // Enter template-parameter scope.
89  ParseScope TemplateParmScope(this, Scope::TemplateParamScope);
90
91  // Tell the action that names should be checked in the context of
92  // the declaration to come.
93  ParsingDeclRAIIObject
94    ParsingTemplateParams(*this, ParsingDeclRAIIObject::NoParent);
95
96  // Parse multiple levels of template headers within this template
97  // parameter scope, e.g.,
98  //
99  //   template<typename T>
100  //     template<typename U>
101  //       class A<T>::B { ... };
102  //
103  // We parse multiple levels non-recursively so that we can build a
104  // single data structure containing all of the template parameter
105  // lists to easily differentiate between the case above and:
106  //
107  //   template<typename T>
108  //   class A {
109  //     template<typename U> class B;
110  //   };
111  //
112  // In the first case, the action for declaring A<T>::B receives
113  // both template parameter lists. In the second case, the action for
114  // defining A<T>::B receives just the inner template parameter list
115  // (and retrieves the outer template parameter list from its
116  // context).
117  bool isSpecialization = true;
118  bool LastParamListWasEmpty = false;
119  TemplateParameterLists ParamLists;
120  TemplateParameterDepthCounter Depth(TemplateParameterDepth);
121  do {
122    // Consume the 'export', if any.
123    SourceLocation ExportLoc;
124    if (Tok.is(tok::kw_export)) {
125      ExportLoc = ConsumeToken();
126    }
127
128    // Consume the 'template', which should be here.
129    SourceLocation TemplateLoc;
130    if (Tok.is(tok::kw_template)) {
131      TemplateLoc = ConsumeToken();
132    } else {
133      Diag(Tok.getLocation(), diag::err_expected_template);
134      return 0;
135    }
136
137    // Parse the '<' template-parameter-list '>'
138    SourceLocation LAngleLoc, RAngleLoc;
139    SmallVector<Decl*, 4> TemplateParams;
140    if (ParseTemplateParameters(Depth, TemplateParams, LAngleLoc,
141                                RAngleLoc)) {
142      // Skip until the semi-colon or a }.
143      SkipUntil(tok::r_brace, true, true);
144      if (Tok.is(tok::semi))
145        ConsumeToken();
146      return 0;
147    }
148
149    ParamLists.push_back(
150      Actions.ActOnTemplateParameterList(Depth, ExportLoc,
151                                         TemplateLoc, LAngleLoc,
152                                         TemplateParams.data(),
153                                         TemplateParams.size(), RAngleLoc));
154
155    if (!TemplateParams.empty()) {
156      isSpecialization = false;
157      ++Depth;
158    } else {
159      LastParamListWasEmpty = true;
160    }
161  } while (Tok.is(tok::kw_export) || Tok.is(tok::kw_template));
162
163  // Parse the actual template declaration.
164  return ParseSingleDeclarationAfterTemplate(Context,
165                                             ParsedTemplateInfo(&ParamLists,
166                                                             isSpecialization,
167                                                         LastParamListWasEmpty),
168                                             ParsingTemplateParams,
169                                             DeclEnd, AS, AccessAttrs);
170}
171
172/// \brief Parse a single declaration that declares a template,
173/// template specialization, or explicit instantiation of a template.
174///
175/// \param DeclEnd will receive the source location of the last token
176/// within this declaration.
177///
178/// \param AS the access specifier associated with this
179/// declaration. Will be AS_none for namespace-scope declarations.
180///
181/// \returns the new declaration.
182Decl *
183Parser::ParseSingleDeclarationAfterTemplate(
184                                       unsigned Context,
185                                       const ParsedTemplateInfo &TemplateInfo,
186                                       ParsingDeclRAIIObject &DiagsFromTParams,
187                                       SourceLocation &DeclEnd,
188                                       AccessSpecifier AS,
189                                       AttributeList *AccessAttrs) {
190  assert(TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate &&
191         "Template information required");
192
193  if (Context == Declarator::MemberContext) {
194    // We are parsing a member template.
195    ParseCXXClassMemberDeclaration(AS, AccessAttrs, TemplateInfo,
196                                   &DiagsFromTParams);
197    return 0;
198  }
199
200  ParsedAttributesWithRange prefixAttrs(AttrFactory);
201  MaybeParseCXX0XAttributes(prefixAttrs);
202
203  if (Tok.is(tok::kw_using))
204    return ParseUsingDirectiveOrDeclaration(Context, TemplateInfo, DeclEnd,
205                                            prefixAttrs);
206
207  // Parse the declaration specifiers, stealing any diagnostics from
208  // the template parameters.
209  ParsingDeclSpec DS(*this, &DiagsFromTParams);
210
211  // Move the attributes from the prefix into the DS.
212  if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation)
213    ProhibitAttributes(prefixAttrs);
214  else
215    DS.takeAttributesFrom(prefixAttrs);
216
217  ParseDeclarationSpecifiers(DS, TemplateInfo, AS,
218                             getDeclSpecContextFromDeclaratorContext(Context));
219
220  if (Tok.is(tok::semi)) {
221    DeclEnd = ConsumeToken();
222    Decl *Decl = Actions.ParsedFreeStandingDeclSpec(getCurScope(), AS, DS);
223    DS.complete(Decl);
224    return Decl;
225  }
226
227  // Parse the declarator.
228  ParsingDeclarator DeclaratorInfo(*this, DS, (Declarator::TheContext)Context);
229  ParseDeclarator(DeclaratorInfo);
230  // Error parsing the declarator?
231  if (!DeclaratorInfo.hasName()) {
232    // If so, skip until the semi-colon or a }.
233    SkipUntil(tok::r_brace, true, true);
234    if (Tok.is(tok::semi))
235      ConsumeToken();
236    return 0;
237  }
238
239  LateParsedAttrList LateParsedAttrs(true);
240  if (DeclaratorInfo.isFunctionDeclarator())
241    MaybeParseGNUAttributes(DeclaratorInfo, &LateParsedAttrs);
242
243  // If we have a declaration or declarator list, handle it.
244  if (isDeclarationAfterDeclarator()) {
245    // Parse this declaration.
246    Decl *ThisDecl = ParseDeclarationAfterDeclarator(DeclaratorInfo,
247                                                     TemplateInfo);
248
249    if (Tok.is(tok::comma)) {
250      Diag(Tok, diag::err_multiple_template_declarators)
251        << (int)TemplateInfo.Kind;
252      SkipUntil(tok::semi, true, false);
253      return ThisDecl;
254    }
255
256    // Eat the semi colon after the declaration.
257    ExpectAndConsumeSemi(diag::err_expected_semi_declaration);
258    if (LateParsedAttrs.size() > 0)
259      ParseLexedAttributeList(LateParsedAttrs, ThisDecl, true, false);
260    DeclaratorInfo.complete(ThisDecl);
261    return ThisDecl;
262  }
263
264  if (DeclaratorInfo.isFunctionDeclarator() &&
265      isStartOfFunctionDefinition(DeclaratorInfo)) {
266    if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) {
267      // Recover by ignoring the 'typedef'. This was probably supposed to be
268      // the 'typename' keyword, which we should have already suggested adding
269      // if it's appropriate.
270      Diag(DS.getStorageClassSpecLoc(), diag::err_function_declared_typedef)
271        << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
272      DS.ClearStorageClassSpecs();
273    }
274    return ParseFunctionDefinition(DeclaratorInfo, TemplateInfo,
275                                   &LateParsedAttrs);
276  }
277
278  if (DeclaratorInfo.isFunctionDeclarator())
279    Diag(Tok, diag::err_expected_fn_body);
280  else
281    Diag(Tok, diag::err_invalid_token_after_toplevel_declarator);
282  SkipUntil(tok::semi);
283  return 0;
284}
285
286/// ParseTemplateParameters - Parses a template-parameter-list enclosed in
287/// angle brackets. Depth is the depth of this template-parameter-list, which
288/// is the number of template headers directly enclosing this template header.
289/// TemplateParams is the current list of template parameters we're building.
290/// The template parameter we parse will be added to this list. LAngleLoc and
291/// RAngleLoc will receive the positions of the '<' and '>', respectively,
292/// that enclose this template parameter list.
293///
294/// \returns true if an error occurred, false otherwise.
295bool Parser::ParseTemplateParameters(unsigned Depth,
296                               SmallVectorImpl<Decl*> &TemplateParams,
297                                     SourceLocation &LAngleLoc,
298                                     SourceLocation &RAngleLoc) {
299  // Get the template parameter list.
300  if (!Tok.is(tok::less)) {
301    Diag(Tok.getLocation(), diag::err_expected_less_after) << "template";
302    return true;
303  }
304  LAngleLoc = ConsumeToken();
305
306  // Try to parse the template parameter list.
307  bool Failed = false;
308  if (!Tok.is(tok::greater) && !Tok.is(tok::greatergreater))
309    Failed = ParseTemplateParameterList(Depth, TemplateParams);
310
311  if (Tok.is(tok::greatergreater)) {
312    // No diagnostic required here: a template-parameter-list can only be
313    // followed by a declaration or, for a template template parameter, the
314    // 'class' keyword. Therefore, the second '>' will be diagnosed later.
315    // This matters for elegant diagnosis of:
316    //   template<template<typename>> struct S;
317    Tok.setKind(tok::greater);
318    RAngleLoc = Tok.getLocation();
319    Tok.setLocation(Tok.getLocation().getLocWithOffset(1));
320  } else if (Tok.is(tok::greater))
321    RAngleLoc = ConsumeToken();
322  else if (Failed) {
323    Diag(Tok.getLocation(), diag::err_expected_greater);
324    return true;
325  }
326  return false;
327}
328
329/// ParseTemplateParameterList - Parse a template parameter list. If
330/// the parsing fails badly (i.e., closing bracket was left out), this
331/// will try to put the token stream in a reasonable position (closing
332/// a statement, etc.) and return false.
333///
334///       template-parameter-list:    [C++ temp]
335///         template-parameter
336///         template-parameter-list ',' template-parameter
337bool
338Parser::ParseTemplateParameterList(unsigned Depth,
339                             SmallVectorImpl<Decl*> &TemplateParams) {
340  while (1) {
341    if (Decl *TmpParam
342          = ParseTemplateParameter(Depth, TemplateParams.size())) {
343      TemplateParams.push_back(TmpParam);
344    } else {
345      // If we failed to parse a template parameter, skip until we find
346      // a comma or closing brace.
347      SkipUntil(tok::comma, tok::greater, tok::greatergreater, true, true);
348    }
349
350    // Did we find a comma or the end of the template parameter list?
351    if (Tok.is(tok::comma)) {
352      ConsumeToken();
353    } else if (Tok.is(tok::greater) || Tok.is(tok::greatergreater)) {
354      // Don't consume this... that's done by template parser.
355      break;
356    } else {
357      // Somebody probably forgot to close the template. Skip ahead and
358      // try to get out of the expression. This error is currently
359      // subsumed by whatever goes on in ParseTemplateParameter.
360      Diag(Tok.getLocation(), diag::err_expected_comma_greater);
361      SkipUntil(tok::comma, tok::greater, tok::greatergreater, true, true);
362      return false;
363    }
364  }
365  return true;
366}
367
368/// \brief Determine whether the parser is at the start of a template
369/// type parameter.
370bool Parser::isStartOfTemplateTypeParameter() {
371  if (Tok.is(tok::kw_class)) {
372    // "class" may be the start of an elaborated-type-specifier or a
373    // type-parameter. Per C++ [temp.param]p3, we prefer the type-parameter.
374    switch (NextToken().getKind()) {
375    case tok::equal:
376    case tok::comma:
377    case tok::greater:
378    case tok::greatergreater:
379    case tok::ellipsis:
380      return true;
381
382    case tok::identifier:
383      // This may be either a type-parameter or an elaborated-type-specifier.
384      // We have to look further.
385      break;
386
387    default:
388      return false;
389    }
390
391    switch (GetLookAheadToken(2).getKind()) {
392    case tok::equal:
393    case tok::comma:
394    case tok::greater:
395    case tok::greatergreater:
396      return true;
397
398    default:
399      return false;
400    }
401  }
402
403  if (Tok.isNot(tok::kw_typename))
404    return false;
405
406  // C++ [temp.param]p2:
407  //   There is no semantic difference between class and typename in a
408  //   template-parameter. typename followed by an unqualified-id
409  //   names a template type parameter. typename followed by a
410  //   qualified-id denotes the type in a non-type
411  //   parameter-declaration.
412  Token Next = NextToken();
413
414  // If we have an identifier, skip over it.
415  if (Next.getKind() == tok::identifier)
416    Next = GetLookAheadToken(2);
417
418  switch (Next.getKind()) {
419  case tok::equal:
420  case tok::comma:
421  case tok::greater:
422  case tok::greatergreater:
423  case tok::ellipsis:
424    return true;
425
426  default:
427    return false;
428  }
429}
430
431/// ParseTemplateParameter - Parse a template-parameter (C++ [temp.param]).
432///
433///       template-parameter: [C++ temp.param]
434///         type-parameter
435///         parameter-declaration
436///
437///       type-parameter: (see below)
438///         'class' ...[opt] identifier[opt]
439///         'class' identifier[opt] '=' type-id
440///         'typename' ...[opt] identifier[opt]
441///         'typename' identifier[opt] '=' type-id
442///         'template' '<' template-parameter-list '>'
443///               'class' ...[opt] identifier[opt]
444///         'template' '<' template-parameter-list '>' 'class' identifier[opt]
445///               = id-expression
446Decl *Parser::ParseTemplateParameter(unsigned Depth, unsigned Position) {
447  if (isStartOfTemplateTypeParameter())
448    return ParseTypeParameter(Depth, Position);
449
450  if (Tok.is(tok::kw_template))
451    return ParseTemplateTemplateParameter(Depth, Position);
452
453  // If it's none of the above, then it must be a parameter declaration.
454  // NOTE: This will pick up errors in the closure of the template parameter
455  // list (e.g., template < ; Check here to implement >> style closures.
456  return ParseNonTypeTemplateParameter(Depth, Position);
457}
458
459/// ParseTypeParameter - Parse a template type parameter (C++ [temp.param]).
460/// Other kinds of template parameters are parsed in
461/// ParseTemplateTemplateParameter and ParseNonTypeTemplateParameter.
462///
463///       type-parameter:     [C++ temp.param]
464///         'class' ...[opt][C++0x] identifier[opt]
465///         'class' identifier[opt] '=' type-id
466///         'typename' ...[opt][C++0x] identifier[opt]
467///         'typename' identifier[opt] '=' type-id
468Decl *Parser::ParseTypeParameter(unsigned Depth, unsigned Position) {
469  assert((Tok.is(tok::kw_class) || Tok.is(tok::kw_typename)) &&
470         "A type-parameter starts with 'class' or 'typename'");
471
472  // Consume the 'class' or 'typename' keyword.
473  bool TypenameKeyword = Tok.is(tok::kw_typename);
474  SourceLocation KeyLoc = ConsumeToken();
475
476  // Grab the ellipsis (if given).
477  bool Ellipsis = false;
478  SourceLocation EllipsisLoc;
479  if (Tok.is(tok::ellipsis)) {
480    Ellipsis = true;
481    EllipsisLoc = ConsumeToken();
482
483    Diag(EllipsisLoc,
484         getLangOpts().CPlusPlus11
485           ? diag::warn_cxx98_compat_variadic_templates
486           : diag::ext_variadic_templates);
487  }
488
489  // Grab the template parameter name (if given)
490  SourceLocation NameLoc;
491  IdentifierInfo* ParamName = 0;
492  if (Tok.is(tok::identifier)) {
493    ParamName = Tok.getIdentifierInfo();
494    NameLoc = ConsumeToken();
495  } else if (Tok.is(tok::equal) || Tok.is(tok::comma) ||
496             Tok.is(tok::greater) || Tok.is(tok::greatergreater)) {
497    // Unnamed template parameter. Don't have to do anything here, just
498    // don't consume this token.
499  } else {
500    Diag(Tok.getLocation(), diag::err_expected_ident);
501    return 0;
502  }
503
504  // Grab a default argument (if available).
505  // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
506  // we introduce the type parameter into the local scope.
507  SourceLocation EqualLoc;
508  ParsedType DefaultArg;
509  if (Tok.is(tok::equal)) {
510    EqualLoc = ConsumeToken();
511    DefaultArg = ParseTypeName(/*Range=*/0,
512                               Declarator::TemplateTypeArgContext).get();
513  }
514
515  return Actions.ActOnTypeParameter(getCurScope(), TypenameKeyword, Ellipsis,
516                                    EllipsisLoc, KeyLoc, ParamName, NameLoc,
517                                    Depth, Position, EqualLoc, DefaultArg);
518}
519
520/// ParseTemplateTemplateParameter - Handle the parsing of template
521/// template parameters.
522///
523///       type-parameter:    [C++ temp.param]
524///         'template' '<' template-parameter-list '>' 'class'
525///                  ...[opt] identifier[opt]
526///         'template' '<' template-parameter-list '>' 'class' identifier[opt]
527///                  = id-expression
528Decl *
529Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
530  assert(Tok.is(tok::kw_template) && "Expected 'template' keyword");
531
532  // Handle the template <...> part.
533  SourceLocation TemplateLoc = ConsumeToken();
534  SmallVector<Decl*,8> TemplateParams;
535  SourceLocation LAngleLoc, RAngleLoc;
536  {
537    ParseScope TemplateParmScope(this, Scope::TemplateParamScope);
538    if (ParseTemplateParameters(Depth + 1, TemplateParams, LAngleLoc,
539                               RAngleLoc)) {
540      return 0;
541    }
542  }
543
544  // Generate a meaningful error if the user forgot to put class before the
545  // identifier, comma, or greater. Provide a fixit if the identifier, comma,
546  // or greater appear immediately or after 'typename' or 'struct'. In the
547  // latter case, replace the keyword with 'class'.
548  if (!Tok.is(tok::kw_class)) {
549    bool Replace = Tok.is(tok::kw_typename) || Tok.is(tok::kw_struct);
550    const Token& Next = Replace ? NextToken() : Tok;
551    if (Next.is(tok::identifier) || Next.is(tok::comma) ||
552        Next.is(tok::greater) || Next.is(tok::greatergreater) ||
553        Next.is(tok::ellipsis))
554      Diag(Tok.getLocation(), diag::err_class_on_template_template_param)
555        << (Replace ? FixItHint::CreateReplacement(Tok.getLocation(), "class")
556                    : FixItHint::CreateInsertion(Tok.getLocation(), "class "));
557    else
558      Diag(Tok.getLocation(), diag::err_class_on_template_template_param);
559
560    if (Replace)
561      ConsumeToken();
562  } else
563    ConsumeToken();
564
565  // Parse the ellipsis, if given.
566  SourceLocation EllipsisLoc;
567  if (Tok.is(tok::ellipsis)) {
568    EllipsisLoc = ConsumeToken();
569
570    Diag(EllipsisLoc,
571         getLangOpts().CPlusPlus11
572           ? diag::warn_cxx98_compat_variadic_templates
573           : diag::ext_variadic_templates);
574  }
575
576  // Get the identifier, if given.
577  SourceLocation NameLoc;
578  IdentifierInfo* ParamName = 0;
579  if (Tok.is(tok::identifier)) {
580    ParamName = Tok.getIdentifierInfo();
581    NameLoc = ConsumeToken();
582  } else if (Tok.is(tok::equal) || Tok.is(tok::comma) ||
583             Tok.is(tok::greater) || Tok.is(tok::greatergreater)) {
584    // Unnamed template parameter. Don't have to do anything here, just
585    // don't consume this token.
586  } else {
587    Diag(Tok.getLocation(), diag::err_expected_ident);
588    return 0;
589  }
590
591  TemplateParameterList *ParamList =
592    Actions.ActOnTemplateParameterList(Depth, SourceLocation(),
593                                       TemplateLoc, LAngleLoc,
594                                       TemplateParams.data(),
595                                       TemplateParams.size(),
596                                       RAngleLoc);
597
598  // Grab a default argument (if available).
599  // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
600  // we introduce the template parameter into the local scope.
601  SourceLocation EqualLoc;
602  ParsedTemplateArgument DefaultArg;
603  if (Tok.is(tok::equal)) {
604    EqualLoc = ConsumeToken();
605    DefaultArg = ParseTemplateTemplateArgument();
606    if (DefaultArg.isInvalid()) {
607      Diag(Tok.getLocation(),
608           diag::err_default_template_template_parameter_not_template);
609      SkipUntil(tok::comma, tok::greater, tok::greatergreater, true, true);
610    }
611  }
612
613  return Actions.ActOnTemplateTemplateParameter(getCurScope(), TemplateLoc,
614                                                ParamList, EllipsisLoc,
615                                                ParamName, NameLoc, Depth,
616                                                Position, EqualLoc, DefaultArg);
617}
618
619/// ParseNonTypeTemplateParameter - Handle the parsing of non-type
620/// template parameters (e.g., in "template<int Size> class array;").
621///
622///       template-parameter:
623///         ...
624///         parameter-declaration
625Decl *
626Parser::ParseNonTypeTemplateParameter(unsigned Depth, unsigned Position) {
627  // Parse the declaration-specifiers (i.e., the type).
628  // FIXME: The type should probably be restricted in some way... Not all
629  // declarators (parts of declarators?) are accepted for parameters.
630  DeclSpec DS(AttrFactory);
631  ParseDeclarationSpecifiers(DS);
632
633  // Parse this as a typename.
634  Declarator ParamDecl(DS, Declarator::TemplateParamContext);
635  ParseDeclarator(ParamDecl);
636  if (DS.getTypeSpecType() == DeclSpec::TST_unspecified) {
637    Diag(Tok.getLocation(), diag::err_expected_template_parameter);
638    return 0;
639  }
640
641  // If there is a default value, parse it.
642  // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
643  // we introduce the template parameter into the local scope.
644  SourceLocation EqualLoc;
645  ExprResult DefaultArg;
646  if (Tok.is(tok::equal)) {
647    EqualLoc = ConsumeToken();
648
649    // C++ [temp.param]p15:
650    //   When parsing a default template-argument for a non-type
651    //   template-parameter, the first non-nested > is taken as the
652    //   end of the template-parameter-list rather than a greater-than
653    //   operator.
654    GreaterThanIsOperatorScope G(GreaterThanIsOperator, false);
655    EnterExpressionEvaluationContext Unevaluated(Actions, Sema::Unevaluated);
656
657    DefaultArg = ParseAssignmentExpression();
658    if (DefaultArg.isInvalid())
659      SkipUntil(tok::comma, tok::greater, true, true);
660  }
661
662  // Create the parameter.
663  return Actions.ActOnNonTypeTemplateParameter(getCurScope(), ParamDecl,
664                                               Depth, Position, EqualLoc,
665                                               DefaultArg.take());
666}
667
668/// \brief Parses a '>' at the end of a template list.
669///
670/// If this function encounters '>>', '>>>', '>=', or '>>=', it tries
671/// to determine if these tokens were supposed to be a '>' followed by
672/// '>', '>>', '>=', or '>='. It emits an appropriate diagnostic if necessary.
673///
674/// \param RAngleLoc the location of the consumed '>'.
675///
676/// \param ConsumeLastToken if true, the '>' is not consumed.
677bool Parser::ParseGreaterThanInTemplateList(SourceLocation &RAngleLoc,
678                                            bool ConsumeLastToken) {
679  // What will be left once we've consumed the '>'.
680  tok::TokenKind RemainingToken;
681  const char *ReplacementStr = "> >";
682
683  switch (Tok.getKind()) {
684  default:
685    Diag(Tok.getLocation(), diag::err_expected_greater);
686    return true;
687
688  case tok::greater:
689    // Determine the location of the '>' token. Only consume this token
690    // if the caller asked us to.
691    RAngleLoc = Tok.getLocation();
692    if (ConsumeLastToken)
693      ConsumeToken();
694    return false;
695
696  case tok::greatergreater:
697    RemainingToken = tok::greater;
698    break;
699
700  case tok::greatergreatergreater:
701    RemainingToken = tok::greatergreater;
702    break;
703
704  case tok::greaterequal:
705    RemainingToken = tok::equal;
706    ReplacementStr = "> =";
707    break;
708
709  case tok::greatergreaterequal:
710    RemainingToken = tok::greaterequal;
711    break;
712  }
713
714  // This template-id is terminated by a token which starts with a '>'. Outside
715  // C++11, this is now error recovery, and in C++11, this is error recovery if
716  // the token isn't '>>'.
717
718  RAngleLoc = Tok.getLocation();
719
720  // The source range of the '>>' or '>=' at the start of the token.
721  CharSourceRange ReplacementRange =
722      CharSourceRange::getCharRange(RAngleLoc,
723          Lexer::AdvanceToTokenCharacter(RAngleLoc, 2, PP.getSourceManager(),
724                                         getLangOpts()));
725
726  // A hint to put a space between the '>>'s. In order to make the hint as
727  // clear as possible, we include the characters either side of the space in
728  // the replacement, rather than just inserting a space at SecondCharLoc.
729  FixItHint Hint1 = FixItHint::CreateReplacement(ReplacementRange,
730                                                 ReplacementStr);
731
732  // A hint to put another space after the token, if it would otherwise be
733  // lexed differently.
734  FixItHint Hint2;
735  Token Next = NextToken();
736  if ((RemainingToken == tok::greater ||
737       RemainingToken == tok::greatergreater) &&
738      (Next.is(tok::greater) || Next.is(tok::greatergreater) ||
739       Next.is(tok::greatergreatergreater) || Next.is(tok::equal) ||
740       Next.is(tok::greaterequal) || Next.is(tok::greatergreaterequal) ||
741       Next.is(tok::equalequal)) &&
742      areTokensAdjacent(Tok, Next))
743    Hint2 = FixItHint::CreateInsertion(Next.getLocation(), " ");
744
745  unsigned DiagId = diag::err_two_right_angle_brackets_need_space;
746  if (getLangOpts().CPlusPlus11 && Tok.is(tok::greatergreater))
747    DiagId = diag::warn_cxx98_compat_two_right_angle_brackets;
748  else if (Tok.is(tok::greaterequal))
749    DiagId = diag::err_right_angle_bracket_equal_needs_space;
750  Diag(Tok.getLocation(), DiagId) << Hint1 << Hint2;
751
752  // Strip the initial '>' from the token.
753  if (RemainingToken == tok::equal && Next.is(tok::equal) &&
754      areTokensAdjacent(Tok, Next)) {
755    // Join two adjacent '=' tokens into one, for cases like:
756    //   void (*p)() = f<int>;
757    //   return f<int>==p;
758    ConsumeToken();
759    Tok.setKind(tok::equalequal);
760    Tok.setLength(Tok.getLength() + 1);
761  } else {
762    Tok.setKind(RemainingToken);
763    Tok.setLength(Tok.getLength() - 1);
764  }
765  Tok.setLocation(Lexer::AdvanceToTokenCharacter(RAngleLoc, 1,
766                                                 PP.getSourceManager(),
767                                                 getLangOpts()));
768
769  if (!ConsumeLastToken) {
770    // Since we're not supposed to consume the '>' token, we need to push
771    // this token and revert the current token back to the '>'.
772    PP.EnterToken(Tok);
773    Tok.setKind(tok::greater);
774    Tok.setLength(1);
775    Tok.setLocation(RAngleLoc);
776  }
777  return false;
778}
779
780
781/// \brief Parses a template-id that after the template name has
782/// already been parsed.
783///
784/// This routine takes care of parsing the enclosed template argument
785/// list ('<' template-parameter-list [opt] '>') and placing the
786/// results into a form that can be transferred to semantic analysis.
787///
788/// \param Template the template declaration produced by isTemplateName
789///
790/// \param TemplateNameLoc the source location of the template name
791///
792/// \param SS if non-NULL, the nested-name-specifier preceding the
793/// template name.
794///
795/// \param ConsumeLastToken if true, then we will consume the last
796/// token that forms the template-id. Otherwise, we will leave the
797/// last token in the stream (e.g., so that it can be replaced with an
798/// annotation token).
799bool
800Parser::ParseTemplateIdAfterTemplateName(TemplateTy Template,
801                                         SourceLocation TemplateNameLoc,
802                                         const CXXScopeSpec &SS,
803                                         bool ConsumeLastToken,
804                                         SourceLocation &LAngleLoc,
805                                         TemplateArgList &TemplateArgs,
806                                         SourceLocation &RAngleLoc) {
807  assert(Tok.is(tok::less) && "Must have already parsed the template-name");
808
809  // Consume the '<'.
810  LAngleLoc = ConsumeToken();
811
812  // Parse the optional template-argument-list.
813  bool Invalid = false;
814  {
815    GreaterThanIsOperatorScope G(GreaterThanIsOperator, false);
816    if (Tok.isNot(tok::greater) && Tok.isNot(tok::greatergreater))
817      Invalid = ParseTemplateArgumentList(TemplateArgs);
818
819    if (Invalid) {
820      // Try to find the closing '>'.
821      SkipUntil(tok::greater, true, !ConsumeLastToken);
822
823      return true;
824    }
825  }
826
827  return ParseGreaterThanInTemplateList(RAngleLoc, ConsumeLastToken);
828}
829
830/// \brief Replace the tokens that form a simple-template-id with an
831/// annotation token containing the complete template-id.
832///
833/// The first token in the stream must be the name of a template that
834/// is followed by a '<'. This routine will parse the complete
835/// simple-template-id and replace the tokens with a single annotation
836/// token with one of two different kinds: if the template-id names a
837/// type (and \p AllowTypeAnnotation is true), the annotation token is
838/// a type annotation that includes the optional nested-name-specifier
839/// (\p SS). Otherwise, the annotation token is a template-id
840/// annotation that does not include the optional
841/// nested-name-specifier.
842///
843/// \param Template  the declaration of the template named by the first
844/// token (an identifier), as returned from \c Action::isTemplateName().
845///
846/// \param TNK the kind of template that \p Template
847/// refers to, as returned from \c Action::isTemplateName().
848///
849/// \param SS if non-NULL, the nested-name-specifier that precedes
850/// this template name.
851///
852/// \param TemplateKWLoc if valid, specifies that this template-id
853/// annotation was preceded by the 'template' keyword and gives the
854/// location of that keyword. If invalid (the default), then this
855/// template-id was not preceded by a 'template' keyword.
856///
857/// \param AllowTypeAnnotation if true (the default), then a
858/// simple-template-id that refers to a class template, template
859/// template parameter, or other template that produces a type will be
860/// replaced with a type annotation token. Otherwise, the
861/// simple-template-id is always replaced with a template-id
862/// annotation token.
863///
864/// If an unrecoverable parse error occurs and no annotation token can be
865/// formed, this function returns true.
866///
867bool Parser::AnnotateTemplateIdToken(TemplateTy Template, TemplateNameKind TNK,
868                                     CXXScopeSpec &SS,
869                                     SourceLocation TemplateKWLoc,
870                                     UnqualifiedId &TemplateName,
871                                     bool AllowTypeAnnotation) {
872  assert(getLangOpts().CPlusPlus && "Can only annotate template-ids in C++");
873  assert(Template && Tok.is(tok::less) &&
874         "Parser isn't at the beginning of a template-id");
875
876  // Consume the template-name.
877  SourceLocation TemplateNameLoc = TemplateName.getSourceRange().getBegin();
878
879  // Parse the enclosed template argument list.
880  SourceLocation LAngleLoc, RAngleLoc;
881  TemplateArgList TemplateArgs;
882  bool Invalid = ParseTemplateIdAfterTemplateName(Template,
883                                                  TemplateNameLoc,
884                                                  SS, false, LAngleLoc,
885                                                  TemplateArgs,
886                                                  RAngleLoc);
887
888  if (Invalid) {
889    // If we failed to parse the template ID but skipped ahead to a >, we're not
890    // going to be able to form a token annotation.  Eat the '>' if present.
891    if (Tok.is(tok::greater))
892      ConsumeToken();
893    return true;
894  }
895
896  ASTTemplateArgsPtr TemplateArgsPtr(TemplateArgs);
897
898  // Build the annotation token.
899  if (TNK == TNK_Type_template && AllowTypeAnnotation) {
900    TypeResult Type
901      = Actions.ActOnTemplateIdType(SS, TemplateKWLoc,
902                                    Template, TemplateNameLoc,
903                                    LAngleLoc, TemplateArgsPtr, RAngleLoc);
904    if (Type.isInvalid()) {
905      // If we failed to parse the template ID but skipped ahead to a >, we're not
906      // going to be able to form a token annotation.  Eat the '>' if present.
907      if (Tok.is(tok::greater))
908        ConsumeToken();
909      return true;
910    }
911
912    Tok.setKind(tok::annot_typename);
913    setTypeAnnotation(Tok, Type.get());
914    if (SS.isNotEmpty())
915      Tok.setLocation(SS.getBeginLoc());
916    else if (TemplateKWLoc.isValid())
917      Tok.setLocation(TemplateKWLoc);
918    else
919      Tok.setLocation(TemplateNameLoc);
920  } else {
921    // Build a template-id annotation token that can be processed
922    // later.
923    Tok.setKind(tok::annot_template_id);
924    TemplateIdAnnotation *TemplateId
925      = TemplateIdAnnotation::Allocate(TemplateArgs.size(), TemplateIds);
926    TemplateId->TemplateNameLoc = TemplateNameLoc;
927    if (TemplateName.getKind() == UnqualifiedId::IK_Identifier) {
928      TemplateId->Name = TemplateName.Identifier;
929      TemplateId->Operator = OO_None;
930    } else {
931      TemplateId->Name = 0;
932      TemplateId->Operator = TemplateName.OperatorFunctionId.Operator;
933    }
934    TemplateId->SS = SS;
935    TemplateId->TemplateKWLoc = TemplateKWLoc;
936    TemplateId->Template = Template;
937    TemplateId->Kind = TNK;
938    TemplateId->LAngleLoc = LAngleLoc;
939    TemplateId->RAngleLoc = RAngleLoc;
940    ParsedTemplateArgument *Args = TemplateId->getTemplateArgs();
941    for (unsigned Arg = 0, ArgEnd = TemplateArgs.size(); Arg != ArgEnd; ++Arg)
942      Args[Arg] = ParsedTemplateArgument(TemplateArgs[Arg]);
943    Tok.setAnnotationValue(TemplateId);
944    if (TemplateKWLoc.isValid())
945      Tok.setLocation(TemplateKWLoc);
946    else
947      Tok.setLocation(TemplateNameLoc);
948  }
949
950  // Common fields for the annotation token
951  Tok.setAnnotationEndLoc(RAngleLoc);
952
953  // In case the tokens were cached, have Preprocessor replace them with the
954  // annotation token.
955  PP.AnnotateCachedTokens(Tok);
956  return false;
957}
958
959/// \brief Replaces a template-id annotation token with a type
960/// annotation token.
961///
962/// If there was a failure when forming the type from the template-id,
963/// a type annotation token will still be created, but will have a
964/// NULL type pointer to signify an error.
965void Parser::AnnotateTemplateIdTokenAsType() {
966  assert(Tok.is(tok::annot_template_id) && "Requires template-id tokens");
967
968  TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
969  assert((TemplateId->Kind == TNK_Type_template ||
970          TemplateId->Kind == TNK_Dependent_template_name) &&
971         "Only works for type and dependent templates");
972
973  ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
974                                     TemplateId->NumArgs);
975
976  TypeResult Type
977    = Actions.ActOnTemplateIdType(TemplateId->SS,
978                                  TemplateId->TemplateKWLoc,
979                                  TemplateId->Template,
980                                  TemplateId->TemplateNameLoc,
981                                  TemplateId->LAngleLoc,
982                                  TemplateArgsPtr,
983                                  TemplateId->RAngleLoc);
984  // Create the new "type" annotation token.
985  Tok.setKind(tok::annot_typename);
986  setTypeAnnotation(Tok, Type.isInvalid() ? ParsedType() : Type.get());
987  if (TemplateId->SS.isNotEmpty()) // it was a C++ qualified type name.
988    Tok.setLocation(TemplateId->SS.getBeginLoc());
989  // End location stays the same
990
991  // Replace the template-id annotation token, and possible the scope-specifier
992  // that precedes it, with the typename annotation token.
993  PP.AnnotateCachedTokens(Tok);
994}
995
996/// \brief Determine whether the given token can end a template argument.
997static bool isEndOfTemplateArgument(Token Tok) {
998  return Tok.is(tok::comma) || Tok.is(tok::greater) ||
999         Tok.is(tok::greatergreater);
1000}
1001
1002/// \brief Parse a C++ template template argument.
1003ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() {
1004  if (!Tok.is(tok::identifier) && !Tok.is(tok::coloncolon) &&
1005      !Tok.is(tok::annot_cxxscope))
1006    return ParsedTemplateArgument();
1007
1008  // C++0x [temp.arg.template]p1:
1009  //   A template-argument for a template template-parameter shall be the name
1010  //   of a class template or an alias template, expressed as id-expression.
1011  //
1012  // We parse an id-expression that refers to a class template or alias
1013  // template. The grammar we parse is:
1014  //
1015  //   nested-name-specifier[opt] template[opt] identifier ...[opt]
1016  //
1017  // followed by a token that terminates a template argument, such as ',',
1018  // '>', or (in some cases) '>>'.
1019  CXXScopeSpec SS; // nested-name-specifier, if present
1020  ParseOptionalCXXScopeSpecifier(SS, ParsedType(),
1021                                 /*EnteringContext=*/false);
1022
1023  ParsedTemplateArgument Result;
1024  SourceLocation EllipsisLoc;
1025  if (SS.isSet() && Tok.is(tok::kw_template)) {
1026    // Parse the optional 'template' keyword following the
1027    // nested-name-specifier.
1028    SourceLocation TemplateKWLoc = ConsumeToken();
1029
1030    if (Tok.is(tok::identifier)) {
1031      // We appear to have a dependent template name.
1032      UnqualifiedId Name;
1033      Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
1034      ConsumeToken(); // the identifier
1035
1036      // Parse the ellipsis.
1037      if (Tok.is(tok::ellipsis))
1038        EllipsisLoc = ConsumeToken();
1039
1040      // If the next token signals the end of a template argument,
1041      // then we have a dependent template name that could be a template
1042      // template argument.
1043      TemplateTy Template;
1044      if (isEndOfTemplateArgument(Tok) &&
1045          Actions.ActOnDependentTemplateName(getCurScope(),
1046                                             SS, TemplateKWLoc, Name,
1047                                             /*ObjectType=*/ ParsedType(),
1048                                             /*EnteringContext=*/false,
1049                                             Template))
1050        Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
1051    }
1052  } else if (Tok.is(tok::identifier)) {
1053    // We may have a (non-dependent) template name.
1054    TemplateTy Template;
1055    UnqualifiedId Name;
1056    Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
1057    ConsumeToken(); // the identifier
1058
1059    // Parse the ellipsis.
1060    if (Tok.is(tok::ellipsis))
1061      EllipsisLoc = ConsumeToken();
1062
1063    if (isEndOfTemplateArgument(Tok)) {
1064      bool MemberOfUnknownSpecialization;
1065      TemplateNameKind TNK = Actions.isTemplateName(getCurScope(), SS,
1066                                               /*hasTemplateKeyword=*/false,
1067                                                    Name,
1068                                               /*ObjectType=*/ ParsedType(),
1069                                                    /*EnteringContext=*/false,
1070                                                    Template,
1071                                                MemberOfUnknownSpecialization);
1072      if (TNK == TNK_Dependent_template_name || TNK == TNK_Type_template) {
1073        // We have an id-expression that refers to a class template or
1074        // (C++0x) alias template.
1075        Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
1076      }
1077    }
1078  }
1079
1080  // If this is a pack expansion, build it as such.
1081  if (EllipsisLoc.isValid() && !Result.isInvalid())
1082    Result = Actions.ActOnPackExpansion(Result, EllipsisLoc);
1083
1084  return Result;
1085}
1086
1087/// ParseTemplateArgument - Parse a C++ template argument (C++ [temp.names]).
1088///
1089///       template-argument: [C++ 14.2]
1090///         constant-expression
1091///         type-id
1092///         id-expression
1093ParsedTemplateArgument Parser::ParseTemplateArgument() {
1094  // C++ [temp.arg]p2:
1095  //   In a template-argument, an ambiguity between a type-id and an
1096  //   expression is resolved to a type-id, regardless of the form of
1097  //   the corresponding template-parameter.
1098  //
1099  // Therefore, we initially try to parse a type-id.
1100  if (isCXXTypeId(TypeIdAsTemplateArgument)) {
1101    SourceLocation Loc = Tok.getLocation();
1102    TypeResult TypeArg = ParseTypeName(/*Range=*/0,
1103                                       Declarator::TemplateTypeArgContext);
1104    if (TypeArg.isInvalid())
1105      return ParsedTemplateArgument();
1106
1107    return ParsedTemplateArgument(ParsedTemplateArgument::Type,
1108                                  TypeArg.get().getAsOpaquePtr(),
1109                                  Loc);
1110  }
1111
1112  // Try to parse a template template argument.
1113  {
1114    TentativeParsingAction TPA(*this);
1115
1116    ParsedTemplateArgument TemplateTemplateArgument
1117      = ParseTemplateTemplateArgument();
1118    if (!TemplateTemplateArgument.isInvalid()) {
1119      TPA.Commit();
1120      return TemplateTemplateArgument;
1121    }
1122
1123    // Revert this tentative parse to parse a non-type template argument.
1124    TPA.Revert();
1125  }
1126
1127  // Parse a non-type template argument.
1128  SourceLocation Loc = Tok.getLocation();
1129  ExprResult ExprArg = ParseConstantExpression(MaybeTypeCast);
1130  if (ExprArg.isInvalid() || !ExprArg.get())
1131    return ParsedTemplateArgument();
1132
1133  return ParsedTemplateArgument(ParsedTemplateArgument::NonType,
1134                                ExprArg.release(), Loc);
1135}
1136
1137/// \brief Determine whether the current tokens can only be parsed as a
1138/// template argument list (starting with the '<') and never as a '<'
1139/// expression.
1140bool Parser::IsTemplateArgumentList(unsigned Skip) {
1141  struct AlwaysRevertAction : TentativeParsingAction {
1142    AlwaysRevertAction(Parser &P) : TentativeParsingAction(P) { }
1143    ~AlwaysRevertAction() { Revert(); }
1144  } Tentative(*this);
1145
1146  while (Skip) {
1147    ConsumeToken();
1148    --Skip;
1149  }
1150
1151  // '<'
1152  if (!Tok.is(tok::less))
1153    return false;
1154  ConsumeToken();
1155
1156  // An empty template argument list.
1157  if (Tok.is(tok::greater))
1158    return true;
1159
1160  // See whether we have declaration specifiers, which indicate a type.
1161  while (isCXXDeclarationSpecifier() == TPResult::True())
1162    ConsumeToken();
1163
1164  // If we have a '>' or a ',' then this is a template argument list.
1165  return Tok.is(tok::greater) || Tok.is(tok::comma);
1166}
1167
1168/// ParseTemplateArgumentList - Parse a C++ template-argument-list
1169/// (C++ [temp.names]). Returns true if there was an error.
1170///
1171///       template-argument-list: [C++ 14.2]
1172///         template-argument
1173///         template-argument-list ',' template-argument
1174bool
1175Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs) {
1176  while (true) {
1177    ParsedTemplateArgument Arg = ParseTemplateArgument();
1178    if (Tok.is(tok::ellipsis)) {
1179      SourceLocation EllipsisLoc  = ConsumeToken();
1180      Arg = Actions.ActOnPackExpansion(Arg, EllipsisLoc);
1181    }
1182
1183    if (Arg.isInvalid()) {
1184      SkipUntil(tok::comma, tok::greater, true, true);
1185      return true;
1186    }
1187
1188    // Save this template argument.
1189    TemplateArgs.push_back(Arg);
1190
1191    // If the next token is a comma, consume it and keep reading
1192    // arguments.
1193    if (Tok.isNot(tok::comma)) break;
1194
1195    // Consume the comma.
1196    ConsumeToken();
1197  }
1198
1199  return false;
1200}
1201
1202/// \brief Parse a C++ explicit template instantiation
1203/// (C++ [temp.explicit]).
1204///
1205///       explicit-instantiation:
1206///         'extern' [opt] 'template' declaration
1207///
1208/// Note that the 'extern' is a GNU extension and C++0x feature.
1209Decl *Parser::ParseExplicitInstantiation(unsigned Context,
1210                                         SourceLocation ExternLoc,
1211                                         SourceLocation TemplateLoc,
1212                                         SourceLocation &DeclEnd,
1213                                         AccessSpecifier AS) {
1214  // This isn't really required here.
1215  ParsingDeclRAIIObject
1216    ParsingTemplateParams(*this, ParsingDeclRAIIObject::NoParent);
1217
1218  return ParseSingleDeclarationAfterTemplate(Context,
1219                                             ParsedTemplateInfo(ExternLoc,
1220                                                                TemplateLoc),
1221                                             ParsingTemplateParams,
1222                                             DeclEnd, AS);
1223}
1224
1225SourceRange Parser::ParsedTemplateInfo::getSourceRange() const {
1226  if (TemplateParams)
1227    return getTemplateParamsRange(TemplateParams->data(),
1228                                  TemplateParams->size());
1229
1230  SourceRange R(TemplateLoc);
1231  if (ExternLoc.isValid())
1232    R.setBegin(ExternLoc);
1233  return R;
1234}
1235
1236void Parser::LateTemplateParserCallback(void *P, const FunctionDecl *FD) {
1237  ((Parser*)P)->LateTemplateParser(FD);
1238}
1239
1240
1241void Parser::LateTemplateParser(const FunctionDecl *FD) {
1242  LateParsedTemplatedFunction *LPT = LateParsedTemplateMap[FD];
1243  if (LPT) {
1244    ParseLateTemplatedFuncDef(*LPT);
1245    return;
1246  }
1247
1248  llvm_unreachable("Late templated function without associated lexed tokens");
1249}
1250
1251/// \brief Late parse a C++ function template in Microsoft mode.
1252void Parser::ParseLateTemplatedFuncDef(LateParsedTemplatedFunction &LMT) {
1253  if(!LMT.D)
1254     return;
1255
1256  // Get the FunctionDecl.
1257  FunctionDecl *FD = 0;
1258  if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(LMT.D))
1259    FD = FunTmpl->getTemplatedDecl();
1260  else
1261    FD = cast<FunctionDecl>(LMT.D);
1262
1263  // To restore the context after late parsing.
1264  Sema::ContextRAII GlobalSavedContext(Actions, Actions.CurContext);
1265
1266  SmallVector<ParseScope*, 4> TemplateParamScopeStack;
1267  DeclaratorDecl* Declarator = dyn_cast<DeclaratorDecl>(FD);
1268  if (Declarator && Declarator->getNumTemplateParameterLists() != 0) {
1269    TemplateParamScopeStack.push_back(new ParseScope(this, Scope::TemplateParamScope));
1270    Actions.ActOnReenterDeclaratorTemplateScope(getCurScope(), Declarator);
1271    Actions.ActOnReenterTemplateScope(getCurScope(), LMT.D);
1272  } else {
1273    // Get the list of DeclContext to reenter.
1274    SmallVector<DeclContext*, 4> DeclContextToReenter;
1275    DeclContext *DD = FD->getLexicalParent();
1276    while (DD && !DD->isTranslationUnit()) {
1277      DeclContextToReenter.push_back(DD);
1278      DD = DD->getLexicalParent();
1279    }
1280
1281    // Reenter template scopes from outmost to innermost.
1282    SmallVector<DeclContext*, 4>::reverse_iterator II =
1283    DeclContextToReenter.rbegin();
1284    for (; II != DeclContextToReenter.rend(); ++II) {
1285      if (ClassTemplatePartialSpecializationDecl* MD =
1286                dyn_cast_or_null<ClassTemplatePartialSpecializationDecl>(*II)) {
1287        TemplateParamScopeStack.push_back(new ParseScope(this,
1288                                                   Scope::TemplateParamScope));
1289        Actions.ActOnReenterTemplateScope(getCurScope(), MD);
1290      } else if (CXXRecordDecl* MD = dyn_cast_or_null<CXXRecordDecl>(*II)) {
1291        TemplateParamScopeStack.push_back(new ParseScope(this,
1292                                                    Scope::TemplateParamScope,
1293                                       MD->getDescribedClassTemplate() != 0 ));
1294        Actions.ActOnReenterTemplateScope(getCurScope(),
1295                                          MD->getDescribedClassTemplate());
1296      }
1297      TemplateParamScopeStack.push_back(new ParseScope(this, Scope::DeclScope));
1298      Actions.PushDeclContext(Actions.getCurScope(), *II);
1299    }
1300    TemplateParamScopeStack.push_back(new ParseScope(this,
1301                                      Scope::TemplateParamScope));
1302    Actions.ActOnReenterTemplateScope(getCurScope(), LMT.D);
1303  }
1304
1305  assert(!LMT.Toks.empty() && "Empty body!");
1306
1307  // Append the current token at the end of the new token stream so that it
1308  // doesn't get lost.
1309  LMT.Toks.push_back(Tok);
1310  PP.EnterTokenStream(LMT.Toks.data(), LMT.Toks.size(), true, false);
1311
1312  // Consume the previously pushed token.
1313  ConsumeAnyToken();
1314  assert((Tok.is(tok::l_brace) || Tok.is(tok::colon) || Tok.is(tok::kw_try))
1315         && "Inline method not starting with '{', ':' or 'try'");
1316
1317  // Parse the method body. Function body parsing code is similar enough
1318  // to be re-used for method bodies as well.
1319  ParseScope FnScope(this, Scope::FnScope|Scope::DeclScope);
1320
1321  // Recreate the containing function DeclContext.
1322  Sema::ContextRAII FunctionSavedContext(Actions, Actions.getContainingDC(FD));
1323
1324  if (FunctionTemplateDecl *FunctionTemplate
1325        = dyn_cast_or_null<FunctionTemplateDecl>(LMT.D))
1326    Actions.ActOnStartOfFunctionDef(getCurScope(),
1327                                   FunctionTemplate->getTemplatedDecl());
1328  if (FunctionDecl *Function = dyn_cast_or_null<FunctionDecl>(LMT.D))
1329    Actions.ActOnStartOfFunctionDef(getCurScope(), Function);
1330
1331
1332  if (Tok.is(tok::kw_try)) {
1333    ParseFunctionTryBlock(LMT.D, FnScope);
1334  } else {
1335    if (Tok.is(tok::colon))
1336      ParseConstructorInitializer(LMT.D);
1337    else
1338      Actions.ActOnDefaultCtorInitializers(LMT.D);
1339
1340    if (Tok.is(tok::l_brace)) {
1341      ParseFunctionStatementBody(LMT.D, FnScope);
1342      Actions.MarkAsLateParsedTemplate(FD, false);
1343    } else
1344      Actions.ActOnFinishFunctionBody(LMT.D, 0);
1345  }
1346
1347  // Exit scopes.
1348  FnScope.Exit();
1349  SmallVector<ParseScope*, 4>::reverse_iterator I =
1350   TemplateParamScopeStack.rbegin();
1351  for (; I != TemplateParamScopeStack.rend(); ++I)
1352    delete *I;
1353
1354  DeclGroupPtrTy grp = Actions.ConvertDeclToDeclGroup(LMT.D);
1355  if (grp)
1356    Actions.getASTConsumer().HandleTopLevelDecl(grp.get());
1357}
1358
1359/// \brief Lex a delayed template function for late parsing.
1360void Parser::LexTemplateFunctionForLateParsing(CachedTokens &Toks) {
1361  tok::TokenKind kind = Tok.getKind();
1362  if (!ConsumeAndStoreFunctionPrologue(Toks)) {
1363    // Consume everything up to (and including) the matching right brace.
1364    ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
1365  }
1366
1367  // If we're in a function-try-block, we need to store all the catch blocks.
1368  if (kind == tok::kw_try) {
1369    while (Tok.is(tok::kw_catch)) {
1370      ConsumeAndStoreUntil(tok::l_brace, Toks, /*StopAtSemi=*/false);
1371      ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
1372    }
1373  }
1374}
1375