ParseTemplate.cpp revision 688f9866c7d35725c947b080fb17055446912390 
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
43
44/// \brief Parse a template declaration or an explicit specialization.
45///
46/// Template declarations include one or more template parameter lists
47/// and either the function or class template declaration. Explicit
48/// specializations contain one or more 'template < >' prefixes
49/// followed by a (possibly templated) declaration. Since the
50/// syntactic form of both features is nearly identical, we parse all
51/// of the template headers together and let semantic analysis sort
52/// the declarations from the explicit specializations.
53///
54///       template-declaration: [C++ temp]
55///         'export'[opt] 'template' '<' template-parameter-list '>' declaration
56///
57///       explicit-specialization: [ C++ temp.expl.spec]
58///         'template' '<' '>' declaration
59Decl *
60Parser::ParseTemplateDeclarationOrSpecialization(unsigned Context,
61                                                 SourceLocation &DeclEnd,
62                                                 AccessSpecifier AS,
63                                                 AttributeList *AccessAttrs) {
64  assert((Tok.is(tok::kw_export) || Tok.is(tok::kw_template)) &&
65         "Token does not start a template declaration.");
66
67  // Enter template-parameter scope.
68  ParseScope TemplateParmScope(this, Scope::TemplateParamScope);
69
70  // Tell the action that names should be checked in the context of
71  // the declaration to come.
72  ParsingDeclRAIIObject
73    ParsingTemplateParams(*this, ParsingDeclRAIIObject::NoParent);
74
75  // Parse multiple levels of template headers within this template
76  // parameter scope, e.g.,
77  //
78  //   template<typename T>
79  //     template<typename U>
80  //       class A<T>::B { ... };
81  //
82  // We parse multiple levels non-recursively so that we can build a
83  // single data structure containing all of the template parameter
84  // lists to easily differentiate between the case above and:
85  //
86  //   template<typename T>
87  //   class A {
88  //     template<typename U> class B;
89  //   };
90  //
91  // In the first case, the action for declaring A<T>::B receives
92  // both template parameter lists. In the second case, the action for
93  // defining A<T>::B receives just the inner template parameter list
94  // (and retrieves the outer template parameter list from its
95  // context).
96  bool isSpecialization = true;
97  bool LastParamListWasEmpty = false;
98  TemplateParameterLists ParamLists;
99  TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
100
101  do {
102    // Consume the 'export', if any.
103    SourceLocation ExportLoc;
104    if (Tok.is(tok::kw_export)) {
105      ExportLoc = ConsumeToken();
106    }
107
108    // Consume the 'template', which should be here.
109    SourceLocation TemplateLoc;
110    if (Tok.is(tok::kw_template)) {
111      TemplateLoc = ConsumeToken();
112    } else {
113      Diag(Tok.getLocation(), diag::err_expected_template);
114      return 0;
115    }
116
117    // Parse the '<' template-parameter-list '>'
118    SourceLocation LAngleLoc, RAngleLoc;
119    SmallVector<Decl*, 4> TemplateParams;
120    if (ParseTemplateParameters(CurTemplateDepthTracker.getDepth(),
121                                TemplateParams, LAngleLoc, RAngleLoc)) {
122      // Skip until the semi-colon or a }.
123      SkipUntil(tok::r_brace, true, true);
124      if (Tok.is(tok::semi))
125        ConsumeToken();
126      return 0;
127    }
128
129    ParamLists.push_back(
130      Actions.ActOnTemplateParameterList(CurTemplateDepthTracker.getDepth(),
131                                         ExportLoc,
132                                         TemplateLoc, LAngleLoc,
133                                         TemplateParams.data(),
134                                         TemplateParams.size(), RAngleLoc));
135
136    if (!TemplateParams.empty()) {
137      isSpecialization = false;
138      ++CurTemplateDepthTracker;
139    } else {
140      LastParamListWasEmpty = true;
141    }
142  } while (Tok.is(tok::kw_export) || Tok.is(tok::kw_template));
143
144  // Parse the actual template declaration.
145  return ParseSingleDeclarationAfterTemplate(Context,
146                                             ParsedTemplateInfo(&ParamLists,
147                                                             isSpecialization,
148                                                         LastParamListWasEmpty),
149                                             ParsingTemplateParams,
150                                             DeclEnd, AS, AccessAttrs);
151}
152
153/// \brief Parse a single declaration that declares a template,
154/// template specialization, or explicit instantiation of a template.
155///
156/// \param DeclEnd will receive the source location of the last token
157/// within this declaration.
158///
159/// \param AS the access specifier associated with this
160/// declaration. Will be AS_none for namespace-scope declarations.
161///
162/// \returns the new declaration.
163Decl *
164Parser::ParseSingleDeclarationAfterTemplate(
165                                       unsigned Context,
166                                       const ParsedTemplateInfo &TemplateInfo,
167                                       ParsingDeclRAIIObject &DiagsFromTParams,
168                                       SourceLocation &DeclEnd,
169                                       AccessSpecifier AS,
170                                       AttributeList *AccessAttrs) {
171  assert(TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate &&
172         "Template information required");
173
174  if (Context == Declarator::MemberContext) {
175    // We are parsing a member template.
176    ParseCXXClassMemberDeclaration(AS, AccessAttrs, TemplateInfo,
177                                   &DiagsFromTParams);
178    return 0;
179  }
180
181  ParsedAttributesWithRange prefixAttrs(AttrFactory);
182  MaybeParseCXX11Attributes(prefixAttrs);
183
184  if (Tok.is(tok::kw_using))
185    return ParseUsingDirectiveOrDeclaration(Context, TemplateInfo, DeclEnd,
186                                            prefixAttrs);
187
188  // Parse the declaration specifiers, stealing any diagnostics from
189  // the template parameters.
190  ParsingDeclSpec DS(*this, &DiagsFromTParams);
191
192  ParseDeclarationSpecifiers(DS, TemplateInfo, AS,
193                             getDeclSpecContextFromDeclaratorContext(Context));
194
195  if (Tok.is(tok::semi)) {
196    ProhibitAttributes(prefixAttrs);
197    DeclEnd = ConsumeToken();
198    Decl *Decl = Actions.ParsedFreeStandingDeclSpec(
199        getCurScope(), AS, DS,
200        TemplateInfo.TemplateParams ? *TemplateInfo.TemplateParams
201                                    : MultiTemplateParamsArg(),
202        TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation);
203    DS.complete(Decl);
204    return Decl;
205  }
206
207  // Move the attributes from the prefix into the DS.
208  if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation)
209    ProhibitAttributes(prefixAttrs);
210  else
211    DS.takeAttributesFrom(prefixAttrs);
212
213  // Parse the declarator.
214  ParsingDeclarator DeclaratorInfo(*this, DS, (Declarator::TheContext)Context);
215  ParseDeclarator(DeclaratorInfo);
216  // Error parsing the declarator?
217  if (!DeclaratorInfo.hasName()) {
218    // If so, skip until the semi-colon or a }.
219    SkipUntil(tok::r_brace, true, true);
220    if (Tok.is(tok::semi))
221      ConsumeToken();
222    return 0;
223  }
224
225  LateParsedAttrList LateParsedAttrs(true);
226  if (DeclaratorInfo.isFunctionDeclarator())
227    MaybeParseGNUAttributes(DeclaratorInfo, &LateParsedAttrs);
228
229  if (DeclaratorInfo.isFunctionDeclarator() &&
230      isStartOfFunctionDefinition(DeclaratorInfo)) {
231    if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) {
232      // Recover by ignoring the 'typedef'. This was probably supposed to be
233      // the 'typename' keyword, which we should have already suggested adding
234      // if it's appropriate.
235      Diag(DS.getStorageClassSpecLoc(), diag::err_function_declared_typedef)
236        << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
237      DS.ClearStorageClassSpecs();
238    }
239    return ParseFunctionDefinition(DeclaratorInfo, TemplateInfo,
240                                   &LateParsedAttrs);
241  }
242
243  // Parse this declaration.
244  Decl *ThisDecl = ParseDeclarationAfterDeclarator(DeclaratorInfo,
245                                                   TemplateInfo);
246
247  if (Tok.is(tok::comma)) {
248    Diag(Tok, diag::err_multiple_template_declarators)
249      << (int)TemplateInfo.Kind;
250    SkipUntil(tok::semi, true, false);
251    return ThisDecl;
252  }
253
254  // Eat the semi colon after the declaration.
255  ExpectAndConsumeSemi(diag::err_expected_semi_declaration);
256  if (LateParsedAttrs.size() > 0)
257    ParseLexedAttributeList(LateParsedAttrs, ThisDecl, true, false);
258  DeclaratorInfo.complete(ThisDecl);
259  return ThisDecl;
260}
261
262/// ParseTemplateParameters - Parses a template-parameter-list enclosed in
263/// angle brackets. Depth is the depth of this template-parameter-list, which
264/// is the number of template headers directly enclosing this template header.
265/// TemplateParams is the current list of template parameters we're building.
266/// The template parameter we parse will be added to this list. LAngleLoc and
267/// RAngleLoc will receive the positions of the '<' and '>', respectively,
268/// that enclose this template parameter list.
269///
270/// \returns true if an error occurred, false otherwise.
271bool Parser::ParseTemplateParameters(unsigned Depth,
272                               SmallVectorImpl<Decl*> &TemplateParams,
273                                     SourceLocation &LAngleLoc,
274                                     SourceLocation &RAngleLoc) {
275  // Get the template parameter list.
276  if (!Tok.is(tok::less)) {
277    Diag(Tok.getLocation(), diag::err_expected_less_after) << "template";
278    return true;
279  }
280  LAngleLoc = ConsumeToken();
281
282  // Try to parse the template parameter list.
283  bool Failed = false;
284  if (!Tok.is(tok::greater) && !Tok.is(tok::greatergreater))
285    Failed = ParseTemplateParameterList(Depth, TemplateParams);
286
287  if (Tok.is(tok::greatergreater)) {
288    // No diagnostic required here: a template-parameter-list can only be
289    // followed by a declaration or, for a template template parameter, the
290    // 'class' keyword. Therefore, the second '>' will be diagnosed later.
291    // This matters for elegant diagnosis of:
292    //   template<template<typename>> struct S;
293    Tok.setKind(tok::greater);
294    RAngleLoc = Tok.getLocation();
295    Tok.setLocation(Tok.getLocation().getLocWithOffset(1));
296  } else if (Tok.is(tok::greater))
297    RAngleLoc = ConsumeToken();
298  else if (Failed) {
299    Diag(Tok.getLocation(), diag::err_expected_greater);
300    return true;
301  }
302  return false;
303}
304
305/// ParseTemplateParameterList - Parse a template parameter list. If
306/// the parsing fails badly (i.e., closing bracket was left out), this
307/// will try to put the token stream in a reasonable position (closing
308/// a statement, etc.) and return false.
309///
310///       template-parameter-list:    [C++ temp]
311///         template-parameter
312///         template-parameter-list ',' template-parameter
313bool
314Parser::ParseTemplateParameterList(unsigned Depth,
315                             SmallVectorImpl<Decl*> &TemplateParams) {
316  while (1) {
317    if (Decl *TmpParam
318          = ParseTemplateParameter(Depth, TemplateParams.size())) {
319      TemplateParams.push_back(TmpParam);
320    } else {
321      // If we failed to parse a template parameter, skip until we find
322      // a comma or closing brace.
323      SkipUntil(tok::comma, tok::greater, tok::greatergreater, true, true);
324    }
325
326    // Did we find a comma or the end of the template parameter list?
327    if (Tok.is(tok::comma)) {
328      ConsumeToken();
329    } else if (Tok.is(tok::greater) || Tok.is(tok::greatergreater)) {
330      // Don't consume this... that's done by template parser.
331      break;
332    } else {
333      // Somebody probably forgot to close the template. Skip ahead and
334      // try to get out of the expression. This error is currently
335      // subsumed by whatever goes on in ParseTemplateParameter.
336      Diag(Tok.getLocation(), diag::err_expected_comma_greater);
337      SkipUntil(tok::comma, tok::greater, tok::greatergreater, true, true);
338      return false;
339    }
340  }
341  return true;
342}
343
344/// \brief Determine whether the parser is at the start of a template
345/// type parameter.
346bool Parser::isStartOfTemplateTypeParameter() {
347  if (Tok.is(tok::kw_class)) {
348    // "class" may be the start of an elaborated-type-specifier or a
349    // type-parameter. Per C++ [temp.param]p3, we prefer the type-parameter.
350    switch (NextToken().getKind()) {
351    case tok::equal:
352    case tok::comma:
353    case tok::greater:
354    case tok::greatergreater:
355    case tok::ellipsis:
356      return true;
357
358    case tok::identifier:
359      // This may be either a type-parameter or an elaborated-type-specifier.
360      // We have to look further.
361      break;
362
363    default:
364      return false;
365    }
366
367    switch (GetLookAheadToken(2).getKind()) {
368    case tok::equal:
369    case tok::comma:
370    case tok::greater:
371    case tok::greatergreater:
372      return true;
373
374    default:
375      return false;
376    }
377  }
378
379  if (Tok.isNot(tok::kw_typename))
380    return false;
381
382  // C++ [temp.param]p2:
383  //   There is no semantic difference between class and typename in a
384  //   template-parameter. typename followed by an unqualified-id
385  //   names a template type parameter. typename followed by a
386  //   qualified-id denotes the type in a non-type
387  //   parameter-declaration.
388  Token Next = NextToken();
389
390  // If we have an identifier, skip over it.
391  if (Next.getKind() == tok::identifier)
392    Next = GetLookAheadToken(2);
393
394  switch (Next.getKind()) {
395  case tok::equal:
396  case tok::comma:
397  case tok::greater:
398  case tok::greatergreater:
399  case tok::ellipsis:
400    return true;
401
402  default:
403    return false;
404  }
405}
406
407/// ParseTemplateParameter - Parse a template-parameter (C++ [temp.param]).
408///
409///       template-parameter: [C++ temp.param]
410///         type-parameter
411///         parameter-declaration
412///
413///       type-parameter: (see below)
414///         'class' ...[opt] identifier[opt]
415///         'class' identifier[opt] '=' type-id
416///         'typename' ...[opt] identifier[opt]
417///         'typename' identifier[opt] '=' type-id
418///         'template' '<' template-parameter-list '>'
419///               'class' ...[opt] identifier[opt]
420///         'template' '<' template-parameter-list '>' 'class' identifier[opt]
421///               = id-expression
422Decl *Parser::ParseTemplateParameter(unsigned Depth, unsigned Position) {
423  if (isStartOfTemplateTypeParameter())
424    return ParseTypeParameter(Depth, Position);
425
426  if (Tok.is(tok::kw_template))
427    return ParseTemplateTemplateParameter(Depth, Position);
428
429  // If it's none of the above, then it must be a parameter declaration.
430  // NOTE: This will pick up errors in the closure of the template parameter
431  // list (e.g., template < ; Check here to implement >> style closures.
432  return ParseNonTypeTemplateParameter(Depth, Position);
433}
434
435/// ParseTypeParameter - Parse a template type parameter (C++ [temp.param]).
436/// Other kinds of template parameters are parsed in
437/// ParseTemplateTemplateParameter and ParseNonTypeTemplateParameter.
438///
439///       type-parameter:     [C++ temp.param]
440///         'class' ...[opt][C++0x] identifier[opt]
441///         'class' identifier[opt] '=' type-id
442///         'typename' ...[opt][C++0x] identifier[opt]
443///         'typename' identifier[opt] '=' type-id
444Decl *Parser::ParseTypeParameter(unsigned Depth, unsigned Position) {
445  assert((Tok.is(tok::kw_class) || Tok.is(tok::kw_typename)) &&
446         "A type-parameter starts with 'class' or 'typename'");
447
448  // Consume the 'class' or 'typename' keyword.
449  bool TypenameKeyword = Tok.is(tok::kw_typename);
450  SourceLocation KeyLoc = ConsumeToken();
451
452  // Grab the ellipsis (if given).
453  bool Ellipsis = false;
454  SourceLocation EllipsisLoc;
455  if (Tok.is(tok::ellipsis)) {
456    Ellipsis = true;
457    EllipsisLoc = ConsumeToken();
458
459    Diag(EllipsisLoc,
460         getLangOpts().CPlusPlus11
461           ? diag::warn_cxx98_compat_variadic_templates
462           : diag::ext_variadic_templates);
463  }
464
465  // Grab the template parameter name (if given)
466  SourceLocation NameLoc;
467  IdentifierInfo* ParamName = 0;
468  if (Tok.is(tok::identifier)) {
469    ParamName = Tok.getIdentifierInfo();
470    NameLoc = ConsumeToken();
471  } else if (Tok.is(tok::equal) || Tok.is(tok::comma) ||
472             Tok.is(tok::greater) || Tok.is(tok::greatergreater)) {
473    // Unnamed template parameter. Don't have to do anything here, just
474    // don't consume this token.
475  } else {
476    Diag(Tok.getLocation(), diag::err_expected_ident);
477    return 0;
478  }
479
480  // Grab a default argument (if available).
481  // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
482  // we introduce the type parameter into the local scope.
483  SourceLocation EqualLoc;
484  ParsedType DefaultArg;
485  if (Tok.is(tok::equal)) {
486    EqualLoc = ConsumeToken();
487    DefaultArg = ParseTypeName(/*Range=*/0,
488                               Declarator::TemplateTypeArgContext).get();
489  }
490
491  return Actions.ActOnTypeParameter(getCurScope(), TypenameKeyword, Ellipsis,
492                                    EllipsisLoc, KeyLoc, ParamName, NameLoc,
493                                    Depth, Position, EqualLoc, DefaultArg);
494}
495
496/// ParseTemplateTemplateParameter - Handle the parsing of template
497/// template parameters.
498///
499///       type-parameter:    [C++ temp.param]
500///         'template' '<' template-parameter-list '>' 'class'
501///                  ...[opt] identifier[opt]
502///         'template' '<' template-parameter-list '>' 'class' identifier[opt]
503///                  = id-expression
504Decl *
505Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
506  assert(Tok.is(tok::kw_template) && "Expected 'template' keyword");
507
508  // Handle the template <...> part.
509  SourceLocation TemplateLoc = ConsumeToken();
510  SmallVector<Decl*,8> TemplateParams;
511  SourceLocation LAngleLoc, RAngleLoc;
512  {
513    ParseScope TemplateParmScope(this, Scope::TemplateParamScope);
514    if (ParseTemplateParameters(Depth + 1, TemplateParams, LAngleLoc,
515                               RAngleLoc)) {
516      return 0;
517    }
518  }
519
520  // Generate a meaningful error if the user forgot to put class before the
521  // identifier, comma, or greater. Provide a fixit if the identifier, comma,
522  // or greater appear immediately or after 'typename' or 'struct'. In the
523  // latter case, replace the keyword with 'class'.
524  if (!Tok.is(tok::kw_class)) {
525    bool Replace = Tok.is(tok::kw_typename) || Tok.is(tok::kw_struct);
526    const Token& Next = Replace ? NextToken() : Tok;
527    if (Next.is(tok::identifier) || Next.is(tok::comma) ||
528        Next.is(tok::greater) || Next.is(tok::greatergreater) ||
529        Next.is(tok::ellipsis))
530      Diag(Tok.getLocation(), diag::err_class_on_template_template_param)
531        << (Replace ? FixItHint::CreateReplacement(Tok.getLocation(), "class")
532                    : FixItHint::CreateInsertion(Tok.getLocation(), "class "));
533    else
534      Diag(Tok.getLocation(), diag::err_class_on_template_template_param);
535
536    if (Replace)
537      ConsumeToken();
538  } else
539    ConsumeToken();
540
541  // Parse the ellipsis, if given.
542  SourceLocation EllipsisLoc;
543  if (Tok.is(tok::ellipsis)) {
544    EllipsisLoc = ConsumeToken();
545
546    Diag(EllipsisLoc,
547         getLangOpts().CPlusPlus11
548           ? diag::warn_cxx98_compat_variadic_templates
549           : diag::ext_variadic_templates);
550  }
551
552  // Get the identifier, if given.
553  SourceLocation NameLoc;
554  IdentifierInfo* ParamName = 0;
555  if (Tok.is(tok::identifier)) {
556    ParamName = Tok.getIdentifierInfo();
557    NameLoc = ConsumeToken();
558  } else if (Tok.is(tok::equal) || Tok.is(tok::comma) ||
559             Tok.is(tok::greater) || Tok.is(tok::greatergreater)) {
560    // Unnamed template parameter. Don't have to do anything here, just
561    // don't consume this token.
562  } else {
563    Diag(Tok.getLocation(), diag::err_expected_ident);
564    return 0;
565  }
566
567  TemplateParameterList *ParamList =
568    Actions.ActOnTemplateParameterList(Depth, SourceLocation(),
569                                       TemplateLoc, LAngleLoc,
570                                       TemplateParams.data(),
571                                       TemplateParams.size(),
572                                       RAngleLoc);
573
574  // Grab a default argument (if available).
575  // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
576  // we introduce the template parameter into the local scope.
577  SourceLocation EqualLoc;
578  ParsedTemplateArgument DefaultArg;
579  if (Tok.is(tok::equal)) {
580    EqualLoc = ConsumeToken();
581    DefaultArg = ParseTemplateTemplateArgument();
582    if (DefaultArg.isInvalid()) {
583      Diag(Tok.getLocation(),
584           diag::err_default_template_template_parameter_not_template);
585      SkipUntil(tok::comma, tok::greater, tok::greatergreater, true, true);
586    }
587  }
588
589  return Actions.ActOnTemplateTemplateParameter(getCurScope(), TemplateLoc,
590                                                ParamList, EllipsisLoc,
591                                                ParamName, NameLoc, Depth,
592                                                Position, EqualLoc, DefaultArg);
593}
594
595/// ParseNonTypeTemplateParameter - Handle the parsing of non-type
596/// template parameters (e.g., in "template<int Size> class array;").
597///
598///       template-parameter:
599///         ...
600///         parameter-declaration
601Decl *
602Parser::ParseNonTypeTemplateParameter(unsigned Depth, unsigned Position) {
603  // Parse the declaration-specifiers (i.e., the type).
604  // FIXME: The type should probably be restricted in some way... Not all
605  // declarators (parts of declarators?) are accepted for parameters.
606  DeclSpec DS(AttrFactory);
607  ParseDeclarationSpecifiers(DS);
608
609  // Parse this as a typename.
610  Declarator ParamDecl(DS, Declarator::TemplateParamContext);
611  ParseDeclarator(ParamDecl);
612  if (DS.getTypeSpecType() == DeclSpec::TST_unspecified) {
613    Diag(Tok.getLocation(), diag::err_expected_template_parameter);
614    return 0;
615  }
616
617  // If there is a default value, parse it.
618  // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
619  // we introduce the template parameter into the local scope.
620  SourceLocation EqualLoc;
621  ExprResult DefaultArg;
622  if (Tok.is(tok::equal)) {
623    EqualLoc = ConsumeToken();
624
625    // C++ [temp.param]p15:
626    //   When parsing a default template-argument for a non-type
627    //   template-parameter, the first non-nested > is taken as the
628    //   end of the template-parameter-list rather than a greater-than
629    //   operator.
630    GreaterThanIsOperatorScope G(GreaterThanIsOperator, false);
631    EnterExpressionEvaluationContext Unevaluated(Actions, Sema::Unevaluated);
632
633    DefaultArg = ParseAssignmentExpression();
634    if (DefaultArg.isInvalid())
635      SkipUntil(tok::comma, tok::greater, true, true);
636  }
637
638  // Create the parameter.
639  return Actions.ActOnNonTypeTemplateParameter(getCurScope(), ParamDecl,
640                                               Depth, Position, EqualLoc,
641                                               DefaultArg.take());
642}
643
644/// \brief Parses a '>' at the end of a template list.
645///
646/// If this function encounters '>>', '>>>', '>=', or '>>=', it tries
647/// to determine if these tokens were supposed to be a '>' followed by
648/// '>', '>>', '>=', or '>='. It emits an appropriate diagnostic if necessary.
649///
650/// \param RAngleLoc the location of the consumed '>'.
651///
652/// \param ConsumeLastToken if true, the '>' is not consumed.
653bool Parser::ParseGreaterThanInTemplateList(SourceLocation &RAngleLoc,
654                                            bool ConsumeLastToken) {
655  // What will be left once we've consumed the '>'.
656  tok::TokenKind RemainingToken;
657  const char *ReplacementStr = "> >";
658
659  switch (Tok.getKind()) {
660  default:
661    Diag(Tok.getLocation(), diag::err_expected_greater);
662    return true;
663
664  case tok::greater:
665    // Determine the location of the '>' token. Only consume this token
666    // if the caller asked us to.
667    RAngleLoc = Tok.getLocation();
668    if (ConsumeLastToken)
669      ConsumeToken();
670    return false;
671
672  case tok::greatergreater:
673    RemainingToken = tok::greater;
674    break;
675
676  case tok::greatergreatergreater:
677    RemainingToken = tok::greatergreater;
678    break;
679
680  case tok::greaterequal:
681    RemainingToken = tok::equal;
682    ReplacementStr = "> =";
683    break;
684
685  case tok::greatergreaterequal:
686    RemainingToken = tok::greaterequal;
687    break;
688  }
689
690  // This template-id is terminated by a token which starts with a '>'. Outside
691  // C++11, this is now error recovery, and in C++11, this is error recovery if
692  // the token isn't '>>'.
693
694  RAngleLoc = Tok.getLocation();
695
696  // The source range of the '>>' or '>=' at the start of the token.
697  CharSourceRange ReplacementRange =
698      CharSourceRange::getCharRange(RAngleLoc,
699          Lexer::AdvanceToTokenCharacter(RAngleLoc, 2, PP.getSourceManager(),
700                                         getLangOpts()));
701
702  // A hint to put a space between the '>>'s. In order to make the hint as
703  // clear as possible, we include the characters either side of the space in
704  // the replacement, rather than just inserting a space at SecondCharLoc.
705  FixItHint Hint1 = FixItHint::CreateReplacement(ReplacementRange,
706                                                 ReplacementStr);
707
708  // A hint to put another space after the token, if it would otherwise be
709  // lexed differently.
710  FixItHint Hint2;
711  Token Next = NextToken();
712  if ((RemainingToken == tok::greater ||
713       RemainingToken == tok::greatergreater) &&
714      (Next.is(tok::greater) || Next.is(tok::greatergreater) ||
715       Next.is(tok::greatergreatergreater) || Next.is(tok::equal) ||
716       Next.is(tok::greaterequal) || Next.is(tok::greatergreaterequal) ||
717       Next.is(tok::equalequal)) &&
718      areTokensAdjacent(Tok, Next))
719    Hint2 = FixItHint::CreateInsertion(Next.getLocation(), " ");
720
721  unsigned DiagId = diag::err_two_right_angle_brackets_need_space;
722  if (getLangOpts().CPlusPlus11 && Tok.is(tok::greatergreater))
723    DiagId = diag::warn_cxx98_compat_two_right_angle_brackets;
724  else if (Tok.is(tok::greaterequal))
725    DiagId = diag::err_right_angle_bracket_equal_needs_space;
726  Diag(Tok.getLocation(), DiagId) << Hint1 << Hint2;
727
728  // Strip the initial '>' from the token.
729  if (RemainingToken == tok::equal && Next.is(tok::equal) &&
730      areTokensAdjacent(Tok, Next)) {
731    // Join two adjacent '=' tokens into one, for cases like:
732    //   void (*p)() = f<int>;
733    //   return f<int>==p;
734    ConsumeToken();
735    Tok.setKind(tok::equalequal);
736    Tok.setLength(Tok.getLength() + 1);
737  } else {
738    Tok.setKind(RemainingToken);
739    Tok.setLength(Tok.getLength() - 1);
740  }
741  Tok.setLocation(Lexer::AdvanceToTokenCharacter(RAngleLoc, 1,
742                                                 PP.getSourceManager(),
743                                                 getLangOpts()));
744
745  if (!ConsumeLastToken) {
746    // Since we're not supposed to consume the '>' token, we need to push
747    // this token and revert the current token back to the '>'.
748    PP.EnterToken(Tok);
749    Tok.setKind(tok::greater);
750    Tok.setLength(1);
751    Tok.setLocation(RAngleLoc);
752  }
753  return false;
754}
755
756
757/// \brief Parses a template-id that after the template name has
758/// already been parsed.
759///
760/// This routine takes care of parsing the enclosed template argument
761/// list ('<' template-parameter-list [opt] '>') and placing the
762/// results into a form that can be transferred to semantic analysis.
763///
764/// \param Template the template declaration produced by isTemplateName
765///
766/// \param TemplateNameLoc the source location of the template name
767///
768/// \param SS if non-NULL, the nested-name-specifier preceding the
769/// template name.
770///
771/// \param ConsumeLastToken if true, then we will consume the last
772/// token that forms the template-id. Otherwise, we will leave the
773/// last token in the stream (e.g., so that it can be replaced with an
774/// annotation token).
775bool
776Parser::ParseTemplateIdAfterTemplateName(TemplateTy Template,
777                                         SourceLocation TemplateNameLoc,
778                                         const CXXScopeSpec &SS,
779                                         bool ConsumeLastToken,
780                                         SourceLocation &LAngleLoc,
781                                         TemplateArgList &TemplateArgs,
782                                         SourceLocation &RAngleLoc) {
783  assert(Tok.is(tok::less) && "Must have already parsed the template-name");
784
785  // Consume the '<'.
786  LAngleLoc = ConsumeToken();
787
788  // Parse the optional template-argument-list.
789  bool Invalid = false;
790  {
791    GreaterThanIsOperatorScope G(GreaterThanIsOperator, false);
792    if (Tok.isNot(tok::greater) && Tok.isNot(tok::greatergreater))
793      Invalid = ParseTemplateArgumentList(TemplateArgs);
794
795    if (Invalid) {
796      // Try to find the closing '>'.
797      SkipUntil(tok::greater, true, !ConsumeLastToken);
798
799      return true;
800    }
801  }
802
803  return ParseGreaterThanInTemplateList(RAngleLoc, ConsumeLastToken);
804}
805
806/// \brief Replace the tokens that form a simple-template-id with an
807/// annotation token containing the complete template-id.
808///
809/// The first token in the stream must be the name of a template that
810/// is followed by a '<'. This routine will parse the complete
811/// simple-template-id and replace the tokens with a single annotation
812/// token with one of two different kinds: if the template-id names a
813/// type (and \p AllowTypeAnnotation is true), the annotation token is
814/// a type annotation that includes the optional nested-name-specifier
815/// (\p SS). Otherwise, the annotation token is a template-id
816/// annotation that does not include the optional
817/// nested-name-specifier.
818///
819/// \param Template  the declaration of the template named by the first
820/// token (an identifier), as returned from \c Action::isTemplateName().
821///
822/// \param TNK the kind of template that \p Template
823/// refers to, as returned from \c Action::isTemplateName().
824///
825/// \param SS if non-NULL, the nested-name-specifier that precedes
826/// this template name.
827///
828/// \param TemplateKWLoc if valid, specifies that this template-id
829/// annotation was preceded by the 'template' keyword and gives the
830/// location of that keyword. If invalid (the default), then this
831/// template-id was not preceded by a 'template' keyword.
832///
833/// \param AllowTypeAnnotation if true (the default), then a
834/// simple-template-id that refers to a class template, template
835/// template parameter, or other template that produces a type will be
836/// replaced with a type annotation token. Otherwise, the
837/// simple-template-id is always replaced with a template-id
838/// annotation token.
839///
840/// If an unrecoverable parse error occurs and no annotation token can be
841/// formed, this function returns true.
842///
843bool Parser::AnnotateTemplateIdToken(TemplateTy Template, TemplateNameKind TNK,
844                                     CXXScopeSpec &SS,
845                                     SourceLocation TemplateKWLoc,
846                                     UnqualifiedId &TemplateName,
847                                     bool AllowTypeAnnotation) {
848  assert(getLangOpts().CPlusPlus && "Can only annotate template-ids in C++");
849  assert(Template && Tok.is(tok::less) &&
850         "Parser isn't at the beginning of a template-id");
851
852  // Consume the template-name.
853  SourceLocation TemplateNameLoc = TemplateName.getSourceRange().getBegin();
854
855  // Parse the enclosed template argument list.
856  SourceLocation LAngleLoc, RAngleLoc;
857  TemplateArgList TemplateArgs;
858  bool Invalid = ParseTemplateIdAfterTemplateName(Template,
859                                                  TemplateNameLoc,
860                                                  SS, false, LAngleLoc,
861                                                  TemplateArgs,
862                                                  RAngleLoc);
863
864  if (Invalid) {
865    // If we failed to parse the template ID but skipped ahead to a >, we're not
866    // going to be able to form a token annotation.  Eat the '>' if present.
867    if (Tok.is(tok::greater))
868      ConsumeToken();
869    return true;
870  }
871
872  ASTTemplateArgsPtr TemplateArgsPtr(TemplateArgs);
873
874  // Build the annotation token.
875  if (TNK == TNK_Type_template && AllowTypeAnnotation) {
876    TypeResult Type
877      = Actions.ActOnTemplateIdType(SS, TemplateKWLoc,
878                                    Template, TemplateNameLoc,
879                                    LAngleLoc, TemplateArgsPtr, RAngleLoc);
880    if (Type.isInvalid()) {
881      // If we failed to parse the template ID but skipped ahead to a >, we're not
882      // going to be able to form a token annotation.  Eat the '>' if present.
883      if (Tok.is(tok::greater))
884        ConsumeToken();
885      return true;
886    }
887
888    Tok.setKind(tok::annot_typename);
889    setTypeAnnotation(Tok, Type.get());
890    if (SS.isNotEmpty())
891      Tok.setLocation(SS.getBeginLoc());
892    else if (TemplateKWLoc.isValid())
893      Tok.setLocation(TemplateKWLoc);
894    else
895      Tok.setLocation(TemplateNameLoc);
896  } else {
897    // Build a template-id annotation token that can be processed
898    // later.
899    Tok.setKind(tok::annot_template_id);
900    TemplateIdAnnotation *TemplateId
901      = TemplateIdAnnotation::Allocate(TemplateArgs.size(), TemplateIds);
902    TemplateId->TemplateNameLoc = TemplateNameLoc;
903    if (TemplateName.getKind() == UnqualifiedId::IK_Identifier) {
904      TemplateId->Name = TemplateName.Identifier;
905      TemplateId->Operator = OO_None;
906    } else {
907      TemplateId->Name = 0;
908      TemplateId->Operator = TemplateName.OperatorFunctionId.Operator;
909    }
910    TemplateId->SS = SS;
911    TemplateId->TemplateKWLoc = TemplateKWLoc;
912    TemplateId->Template = Template;
913    TemplateId->Kind = TNK;
914    TemplateId->LAngleLoc = LAngleLoc;
915    TemplateId->RAngleLoc = RAngleLoc;
916    ParsedTemplateArgument *Args = TemplateId->getTemplateArgs();
917    for (unsigned Arg = 0, ArgEnd = TemplateArgs.size(); Arg != ArgEnd; ++Arg)
918      Args[Arg] = ParsedTemplateArgument(TemplateArgs[Arg]);
919    Tok.setAnnotationValue(TemplateId);
920    if (TemplateKWLoc.isValid())
921      Tok.setLocation(TemplateKWLoc);
922    else
923      Tok.setLocation(TemplateNameLoc);
924  }
925
926  // Common fields for the annotation token
927  Tok.setAnnotationEndLoc(RAngleLoc);
928
929  // In case the tokens were cached, have Preprocessor replace them with the
930  // annotation token.
931  PP.AnnotateCachedTokens(Tok);
932  return false;
933}
934
935/// \brief Replaces a template-id annotation token with a type
936/// annotation token.
937///
938/// If there was a failure when forming the type from the template-id,
939/// a type annotation token will still be created, but will have a
940/// NULL type pointer to signify an error.
941void Parser::AnnotateTemplateIdTokenAsType() {
942  assert(Tok.is(tok::annot_template_id) && "Requires template-id tokens");
943
944  TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
945  assert((TemplateId->Kind == TNK_Type_template ||
946          TemplateId->Kind == TNK_Dependent_template_name) &&
947         "Only works for type and dependent templates");
948
949  ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
950                                     TemplateId->NumArgs);
951
952  TypeResult Type
953    = Actions.ActOnTemplateIdType(TemplateId->SS,
954                                  TemplateId->TemplateKWLoc,
955                                  TemplateId->Template,
956                                  TemplateId->TemplateNameLoc,
957                                  TemplateId->LAngleLoc,
958                                  TemplateArgsPtr,
959                                  TemplateId->RAngleLoc);
960  // Create the new "type" annotation token.
961  Tok.setKind(tok::annot_typename);
962  setTypeAnnotation(Tok, Type.isInvalid() ? ParsedType() : Type.get());
963  if (TemplateId->SS.isNotEmpty()) // it was a C++ qualified type name.
964    Tok.setLocation(TemplateId->SS.getBeginLoc());
965  // End location stays the same
966
967  // Replace the template-id annotation token, and possible the scope-specifier
968  // that precedes it, with the typename annotation token.
969  PP.AnnotateCachedTokens(Tok);
970}
971
972/// \brief Determine whether the given token can end a template argument.
973static bool isEndOfTemplateArgument(Token Tok) {
974  return Tok.is(tok::comma) || Tok.is(tok::greater) ||
975         Tok.is(tok::greatergreater);
976}
977
978/// \brief Parse a C++ template template argument.
979ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() {
980  if (!Tok.is(tok::identifier) && !Tok.is(tok::coloncolon) &&
981      !Tok.is(tok::annot_cxxscope))
982    return ParsedTemplateArgument();
983
984  // C++0x [temp.arg.template]p1:
985  //   A template-argument for a template template-parameter shall be the name
986  //   of a class template or an alias template, expressed as id-expression.
987  //
988  // We parse an id-expression that refers to a class template or alias
989  // template. The grammar we parse is:
990  //
991  //   nested-name-specifier[opt] template[opt] identifier ...[opt]
992  //
993  // followed by a token that terminates a template argument, such as ',',
994  // '>', or (in some cases) '>>'.
995  CXXScopeSpec SS; // nested-name-specifier, if present
996  ParseOptionalCXXScopeSpecifier(SS, ParsedType(),
997                                 /*EnteringContext=*/false);
998
999  ParsedTemplateArgument Result;
1000  SourceLocation EllipsisLoc;
1001  if (SS.isSet() && Tok.is(tok::kw_template)) {
1002    // Parse the optional 'template' keyword following the
1003    // nested-name-specifier.
1004    SourceLocation TemplateKWLoc = ConsumeToken();
1005
1006    if (Tok.is(tok::identifier)) {
1007      // We appear to have a dependent template name.
1008      UnqualifiedId Name;
1009      Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
1010      ConsumeToken(); // the identifier
1011
1012      // Parse the ellipsis.
1013      if (Tok.is(tok::ellipsis))
1014        EllipsisLoc = ConsumeToken();
1015
1016      // If the next token signals the end of a template argument,
1017      // then we have a dependent template name that could be a template
1018      // template argument.
1019      TemplateTy Template;
1020      if (isEndOfTemplateArgument(Tok) &&
1021          Actions.ActOnDependentTemplateName(getCurScope(),
1022                                             SS, TemplateKWLoc, Name,
1023                                             /*ObjectType=*/ ParsedType(),
1024                                             /*EnteringContext=*/false,
1025                                             Template))
1026        Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
1027    }
1028  } else if (Tok.is(tok::identifier)) {
1029    // We may have a (non-dependent) template name.
1030    TemplateTy Template;
1031    UnqualifiedId Name;
1032    Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
1033    ConsumeToken(); // the identifier
1034
1035    // Parse the ellipsis.
1036    if (Tok.is(tok::ellipsis))
1037      EllipsisLoc = ConsumeToken();
1038
1039    if (isEndOfTemplateArgument(Tok)) {
1040      bool MemberOfUnknownSpecialization;
1041      TemplateNameKind TNK = Actions.isTemplateName(getCurScope(), SS,
1042                                               /*hasTemplateKeyword=*/false,
1043                                                    Name,
1044                                               /*ObjectType=*/ ParsedType(),
1045                                                    /*EnteringContext=*/false,
1046                                                    Template,
1047                                                MemberOfUnknownSpecialization);
1048      if (TNK == TNK_Dependent_template_name || TNK == TNK_Type_template) {
1049        // We have an id-expression that refers to a class template or
1050        // (C++0x) alias template.
1051        Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
1052      }
1053    }
1054  }
1055
1056  // If this is a pack expansion, build it as such.
1057  if (EllipsisLoc.isValid() && !Result.isInvalid())
1058    Result = Actions.ActOnPackExpansion(Result, EllipsisLoc);
1059
1060  return Result;
1061}
1062
1063/// ParseTemplateArgument - Parse a C++ template argument (C++ [temp.names]).
1064///
1065///       template-argument: [C++ 14.2]
1066///         constant-expression
1067///         type-id
1068///         id-expression
1069ParsedTemplateArgument Parser::ParseTemplateArgument() {
1070  // C++ [temp.arg]p2:
1071  //   In a template-argument, an ambiguity between a type-id and an
1072  //   expression is resolved to a type-id, regardless of the form of
1073  //   the corresponding template-parameter.
1074  //
1075  // Therefore, we initially try to parse a type-id.
1076  if (isCXXTypeId(TypeIdAsTemplateArgument)) {
1077    SourceLocation Loc = Tok.getLocation();
1078    TypeResult TypeArg = ParseTypeName(/*Range=*/0,
1079                                       Declarator::TemplateTypeArgContext);
1080    if (TypeArg.isInvalid())
1081      return ParsedTemplateArgument();
1082
1083    return ParsedTemplateArgument(ParsedTemplateArgument::Type,
1084                                  TypeArg.get().getAsOpaquePtr(),
1085                                  Loc);
1086  }
1087
1088  // Try to parse a template template argument.
1089  {
1090    TentativeParsingAction TPA(*this);
1091
1092    ParsedTemplateArgument TemplateTemplateArgument
1093      = ParseTemplateTemplateArgument();
1094    if (!TemplateTemplateArgument.isInvalid()) {
1095      TPA.Commit();
1096      return TemplateTemplateArgument;
1097    }
1098
1099    // Revert this tentative parse to parse a non-type template argument.
1100    TPA.Revert();
1101  }
1102
1103  // Parse a non-type template argument.
1104  SourceLocation Loc = Tok.getLocation();
1105  ExprResult ExprArg = ParseConstantExpression(MaybeTypeCast);
1106  if (ExprArg.isInvalid() || !ExprArg.get())
1107    return ParsedTemplateArgument();
1108
1109  return ParsedTemplateArgument(ParsedTemplateArgument::NonType,
1110                                ExprArg.release(), Loc);
1111}
1112
1113/// \brief Determine whether the current tokens can only be parsed as a
1114/// template argument list (starting with the '<') and never as a '<'
1115/// expression.
1116bool Parser::IsTemplateArgumentList(unsigned Skip) {
1117  struct AlwaysRevertAction : TentativeParsingAction {
1118    AlwaysRevertAction(Parser &P) : TentativeParsingAction(P) { }
1119    ~AlwaysRevertAction() { Revert(); }
1120  } Tentative(*this);
1121
1122  while (Skip) {
1123    ConsumeToken();
1124    --Skip;
1125  }
1126
1127  // '<'
1128  if (!Tok.is(tok::less))
1129    return false;
1130  ConsumeToken();
1131
1132  // An empty template argument list.
1133  if (Tok.is(tok::greater))
1134    return true;
1135
1136  // See whether we have declaration specifiers, which indicate a type.
1137  while (isCXXDeclarationSpecifier() == TPResult::True())
1138    ConsumeToken();
1139
1140  // If we have a '>' or a ',' then this is a template argument list.
1141  return Tok.is(tok::greater) || Tok.is(tok::comma);
1142}
1143
1144/// ParseTemplateArgumentList - Parse a C++ template-argument-list
1145/// (C++ [temp.names]). Returns true if there was an error.
1146///
1147///       template-argument-list: [C++ 14.2]
1148///         template-argument
1149///         template-argument-list ',' template-argument
1150bool
1151Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs) {
1152  // Template argument lists are constant-evaluation contexts.
1153  EnterExpressionEvaluationContext EvalContext(Actions,Sema::ConstantEvaluated);
1154
1155  while (true) {
1156    ParsedTemplateArgument Arg = ParseTemplateArgument();
1157    if (Tok.is(tok::ellipsis)) {
1158      SourceLocation EllipsisLoc  = ConsumeToken();
1159      Arg = Actions.ActOnPackExpansion(Arg, EllipsisLoc);
1160    }
1161
1162    if (Arg.isInvalid()) {
1163      SkipUntil(tok::comma, tok::greater, true, true);
1164      return true;
1165    }
1166
1167    // Save this template argument.
1168    TemplateArgs.push_back(Arg);
1169
1170    // If the next token is a comma, consume it and keep reading
1171    // arguments.
1172    if (Tok.isNot(tok::comma)) break;
1173
1174    // Consume the comma.
1175    ConsumeToken();
1176  }
1177
1178  return false;
1179}
1180
1181/// \brief Parse a C++ explicit template instantiation
1182/// (C++ [temp.explicit]).
1183///
1184///       explicit-instantiation:
1185///         'extern' [opt] 'template' declaration
1186///
1187/// Note that the 'extern' is a GNU extension and C++11 feature.
1188Decl *Parser::ParseExplicitInstantiation(unsigned Context,
1189                                         SourceLocation ExternLoc,
1190                                         SourceLocation TemplateLoc,
1191                                         SourceLocation &DeclEnd,
1192                                         AccessSpecifier AS) {
1193  // This isn't really required here.
1194  ParsingDeclRAIIObject
1195    ParsingTemplateParams(*this, ParsingDeclRAIIObject::NoParent);
1196
1197  return ParseSingleDeclarationAfterTemplate(Context,
1198                                             ParsedTemplateInfo(ExternLoc,
1199                                                                TemplateLoc),
1200                                             ParsingTemplateParams,
1201                                             DeclEnd, AS);
1202}
1203
1204SourceRange Parser::ParsedTemplateInfo::getSourceRange() const {
1205  if (TemplateParams)
1206    return getTemplateParamsRange(TemplateParams->data(),
1207                                  TemplateParams->size());
1208
1209  SourceRange R(TemplateLoc);
1210  if (ExternLoc.isValid())
1211    R.setBegin(ExternLoc);
1212  return R;
1213}
1214
1215void Parser::LateTemplateParserCallback(void *P, const FunctionDecl *FD) {
1216  ((Parser*)P)->LateTemplateParser(FD);
1217}
1218
1219
1220void Parser::LateTemplateParser(const FunctionDecl *FD) {
1221  LateParsedTemplatedFunction *LPT = LateParsedTemplateMap[FD];
1222  if (LPT) {
1223    ParseLateTemplatedFuncDef(*LPT);
1224    return;
1225  }
1226
1227  llvm_unreachable("Late templated function without associated lexed tokens");
1228}
1229
1230/// \brief Late parse a C++ function template in Microsoft mode.
1231void Parser::ParseLateTemplatedFuncDef(LateParsedTemplatedFunction &LMT) {
1232  if(!LMT.D)
1233     return;
1234
1235  // Get the FunctionDecl.
1236  FunctionTemplateDecl *FunTmplD = dyn_cast<FunctionTemplateDecl>(LMT.D);
1237  FunctionDecl *FunD =
1238      FunTmplD ? FunTmplD->getTemplatedDecl() : cast<FunctionDecl>(LMT.D);
1239  // Track template parameter depth.
1240  TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
1241
1242  // To restore the context after late parsing.
1243  Sema::ContextRAII GlobalSavedContext(Actions, Actions.CurContext);
1244
1245  SmallVector<ParseScope*, 4> TemplateParamScopeStack;
1246
1247  // Get the list of DeclContexts to reenter.
1248  SmallVector<DeclContext*, 4> DeclContextsToReenter;
1249  DeclContext *DD = FunD->getLexicalParent();
1250  while (DD && !DD->isTranslationUnit()) {
1251    DeclContextsToReenter.push_back(DD);
1252    DD = DD->getLexicalParent();
1253  }
1254
1255  // Reenter template scopes from outermost to innermost.
1256  SmallVector<DeclContext*, 4>::reverse_iterator II =
1257      DeclContextsToReenter.rbegin();
1258  for (; II != DeclContextsToReenter.rend(); ++II) {
1259    if (ClassTemplatePartialSpecializationDecl *MD =
1260            dyn_cast_or_null<ClassTemplatePartialSpecializationDecl>(*II)) {
1261      TemplateParamScopeStack.push_back(
1262          new ParseScope(this, Scope::TemplateParamScope));
1263      Actions.ActOnReenterTemplateScope(getCurScope(), MD);
1264      ++CurTemplateDepthTracker;
1265    } else if (CXXRecordDecl *MD = dyn_cast_or_null<CXXRecordDecl>(*II)) {
1266      bool IsClassTemplate = MD->getDescribedClassTemplate() != 0;
1267      TemplateParamScopeStack.push_back(
1268          new ParseScope(this, Scope::TemplateParamScope,
1269                        /*ManageScope*/IsClassTemplate));
1270      Actions.ActOnReenterTemplateScope(getCurScope(),
1271                                        MD->getDescribedClassTemplate());
1272      if (IsClassTemplate)
1273        ++CurTemplateDepthTracker;
1274    }
1275    TemplateParamScopeStack.push_back(new ParseScope(this, Scope::DeclScope));
1276    Actions.PushDeclContext(Actions.getCurScope(), *II);
1277  }
1278  TemplateParamScopeStack.push_back(
1279      new ParseScope(this, Scope::TemplateParamScope));
1280
1281  DeclaratorDecl *Declarator = dyn_cast<DeclaratorDecl>(FunD);
1282  if (Declarator && Declarator->getNumTemplateParameterLists() != 0) {
1283    Actions.ActOnReenterDeclaratorTemplateScope(getCurScope(), Declarator);
1284    ++CurTemplateDepthTracker;
1285  }
1286  Actions.ActOnReenterTemplateScope(getCurScope(), LMT.D);
1287  ++CurTemplateDepthTracker;
1288
1289  assert(!LMT.Toks.empty() && "Empty body!");
1290
1291  // Append the current token at the end of the new token stream so that it
1292  // doesn't get lost.
1293  LMT.Toks.push_back(Tok);
1294  PP.EnterTokenStream(LMT.Toks.data(), LMT.Toks.size(), true, false);
1295
1296  // Consume the previously pushed token.
1297  ConsumeAnyToken(/*ConsumeCodeCompletionTok=*/true);
1298  assert((Tok.is(tok::l_brace) || Tok.is(tok::colon) || Tok.is(tok::kw_try))
1299         && "Inline method not starting with '{', ':' or 'try'");
1300
1301  // Parse the method body. Function body parsing code is similar enough
1302  // to be re-used for method bodies as well.
1303  ParseScope FnScope(this, Scope::FnScope|Scope::DeclScope);
1304
1305  // Recreate the containing function DeclContext.
1306  Sema::ContextRAII FunctionSavedContext(Actions, Actions.getContainingDC(FunD));
1307
1308  Actions.ActOnStartOfFunctionDef(getCurScope(), FunD);
1309
1310  if (Tok.is(tok::kw_try)) {
1311    ParseFunctionTryBlock(LMT.D, FnScope);
1312  } else {
1313    if (Tok.is(tok::colon))
1314      ParseConstructorInitializer(LMT.D);
1315    else
1316      Actions.ActOnDefaultCtorInitializers(LMT.D);
1317
1318    if (Tok.is(tok::l_brace)) {
1319      assert((!FunTmplD || FunTmplD->getTemplateParameters()->getDepth() <
1320                               TemplateParameterDepth) &&
1321             "TemplateParameterDepth should be greater than the depth of "
1322             "current template being instantiated!");
1323      ParseFunctionStatementBody(LMT.D, FnScope);
1324      Actions.MarkAsLateParsedTemplate(FunD, false);
1325    } else
1326      Actions.ActOnFinishFunctionBody(LMT.D, 0);
1327  }
1328
1329  // Exit scopes.
1330  FnScope.Exit();
1331  SmallVector<ParseScope*, 4>::reverse_iterator I =
1332   TemplateParamScopeStack.rbegin();
1333  for (; I != TemplateParamScopeStack.rend(); ++I)
1334    delete *I;
1335
1336  DeclGroupPtrTy grp = Actions.ConvertDeclToDeclGroup(LMT.D);
1337  if (grp)
1338    Actions.getASTConsumer().HandleTopLevelDecl(grp.get());
1339}
1340
1341/// \brief Lex a delayed template function for late parsing.
1342void Parser::LexTemplateFunctionForLateParsing(CachedTokens &Toks) {
1343  tok::TokenKind kind = Tok.getKind();
1344  if (!ConsumeAndStoreFunctionPrologue(Toks)) {
1345    // Consume everything up to (and including) the matching right brace.
1346    ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
1347  }
1348
1349  // If we're in a function-try-block, we need to store all the catch blocks.
1350  if (kind == tok::kw_try) {
1351    while (Tok.is(tok::kw_catch)) {
1352      ConsumeAndStoreUntil(tok::l_brace, Toks, /*StopAtSemi=*/false);
1353      ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
1354    }
1355  }
1356}
1357