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, StopAtSemi | StopBeforeMatch);
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, StopAtSemi | StopBeforeMatch);
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
240    if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation) {
241      if (DeclaratorInfo.getName().getKind() != UnqualifiedId::IK_TemplateId) {
242        // If the declarator-id is not a template-id, issue a diagnostic and
243        // recover by ignoring the 'template' keyword.
244        Diag(Tok, diag::err_template_defn_explicit_instantiation) << 0;
245        return ParseFunctionDefinition(DeclaratorInfo, ParsedTemplateInfo(),
246                                       &LateParsedAttrs);
247      } else {
248        SourceLocation LAngleLoc
249          = PP.getLocForEndOfToken(TemplateInfo.TemplateLoc);
250        Diag(DeclaratorInfo.getIdentifierLoc(),
251             diag::err_explicit_instantiation_with_definition)
252            << SourceRange(TemplateInfo.TemplateLoc)
253            << FixItHint::CreateInsertion(LAngleLoc, "<>");
254
255        // Recover as if it were an explicit specialization.
256        TemplateParameterLists FakedParamLists;
257        FakedParamLists.push_back(Actions.ActOnTemplateParameterList(
258            0, SourceLocation(), TemplateInfo.TemplateLoc, LAngleLoc, 0, 0,
259            LAngleLoc));
260
261        return ParseFunctionDefinition(
262            DeclaratorInfo, ParsedTemplateInfo(&FakedParamLists,
263                                               /*isSpecialization=*/true,
264                                               /*LastParamListWasEmpty=*/true),
265            &LateParsedAttrs);
266      }
267    }
268    return ParseFunctionDefinition(DeclaratorInfo, TemplateInfo,
269                                   &LateParsedAttrs);
270  }
271
272  // Parse this declaration.
273  Decl *ThisDecl = ParseDeclarationAfterDeclarator(DeclaratorInfo,
274                                                   TemplateInfo);
275
276  if (Tok.is(tok::comma)) {
277    Diag(Tok, diag::err_multiple_template_declarators)
278      << (int)TemplateInfo.Kind;
279    SkipUntil(tok::semi);
280    return ThisDecl;
281  }
282
283  // Eat the semi colon after the declaration.
284  ExpectAndConsumeSemi(diag::err_expected_semi_declaration);
285  if (LateParsedAttrs.size() > 0)
286    ParseLexedAttributeList(LateParsedAttrs, ThisDecl, true, false);
287  DeclaratorInfo.complete(ThisDecl);
288  return ThisDecl;
289}
290
291/// ParseTemplateParameters - Parses a template-parameter-list enclosed in
292/// angle brackets. Depth is the depth of this template-parameter-list, which
293/// is the number of template headers directly enclosing this template header.
294/// TemplateParams is the current list of template parameters we're building.
295/// The template parameter we parse will be added to this list. LAngleLoc and
296/// RAngleLoc will receive the positions of the '<' and '>', respectively,
297/// that enclose this template parameter list.
298///
299/// \returns true if an error occurred, false otherwise.
300bool Parser::ParseTemplateParameters(unsigned Depth,
301                               SmallVectorImpl<Decl*> &TemplateParams,
302                                     SourceLocation &LAngleLoc,
303                                     SourceLocation &RAngleLoc) {
304  // Get the template parameter list.
305  if (!Tok.is(tok::less)) {
306    Diag(Tok.getLocation(), diag::err_expected_less_after) << "template";
307    return true;
308  }
309  LAngleLoc = ConsumeToken();
310
311  // Try to parse the template parameter list.
312  bool Failed = false;
313  if (!Tok.is(tok::greater) && !Tok.is(tok::greatergreater))
314    Failed = ParseTemplateParameterList(Depth, TemplateParams);
315
316  if (Tok.is(tok::greatergreater)) {
317    // No diagnostic required here: a template-parameter-list can only be
318    // followed by a declaration or, for a template template parameter, the
319    // 'class' keyword. Therefore, the second '>' will be diagnosed later.
320    // This matters for elegant diagnosis of:
321    //   template<template<typename>> struct S;
322    Tok.setKind(tok::greater);
323    RAngleLoc = Tok.getLocation();
324    Tok.setLocation(Tok.getLocation().getLocWithOffset(1));
325  } else if (Tok.is(tok::greater))
326    RAngleLoc = ConsumeToken();
327  else if (Failed) {
328    Diag(Tok.getLocation(), diag::err_expected_greater);
329    return true;
330  }
331  return false;
332}
333
334/// ParseTemplateParameterList - Parse a template parameter list. If
335/// the parsing fails badly (i.e., closing bracket was left out), this
336/// will try to put the token stream in a reasonable position (closing
337/// a statement, etc.) and return false.
338///
339///       template-parameter-list:    [C++ temp]
340///         template-parameter
341///         template-parameter-list ',' template-parameter
342bool
343Parser::ParseTemplateParameterList(unsigned Depth,
344                             SmallVectorImpl<Decl*> &TemplateParams) {
345  while (1) {
346    if (Decl *TmpParam
347          = ParseTemplateParameter(Depth, TemplateParams.size())) {
348      TemplateParams.push_back(TmpParam);
349    } else {
350      // If we failed to parse a template parameter, skip until we find
351      // a comma or closing brace.
352      SkipUntil(tok::comma, tok::greater, tok::greatergreater,
353                StopAtSemi | StopBeforeMatch);
354    }
355
356    // Did we find a comma or the end of the template parameter list?
357    if (Tok.is(tok::comma)) {
358      ConsumeToken();
359    } else if (Tok.is(tok::greater) || Tok.is(tok::greatergreater)) {
360      // Don't consume this... that's done by template parser.
361      break;
362    } else {
363      // Somebody probably forgot to close the template. Skip ahead and
364      // try to get out of the expression. This error is currently
365      // subsumed by whatever goes on in ParseTemplateParameter.
366      Diag(Tok.getLocation(), diag::err_expected_comma_greater);
367      SkipUntil(tok::comma, tok::greater, tok::greatergreater,
368                StopAtSemi | StopBeforeMatch);
369      return false;
370    }
371  }
372  return true;
373}
374
375/// \brief Determine whether the parser is at the start of a template
376/// type parameter.
377bool Parser::isStartOfTemplateTypeParameter() {
378  if (Tok.is(tok::kw_class)) {
379    // "class" may be the start of an elaborated-type-specifier or a
380    // type-parameter. Per C++ [temp.param]p3, we prefer the type-parameter.
381    switch (NextToken().getKind()) {
382    case tok::equal:
383    case tok::comma:
384    case tok::greater:
385    case tok::greatergreater:
386    case tok::ellipsis:
387      return true;
388
389    case tok::identifier:
390      // This may be either a type-parameter or an elaborated-type-specifier.
391      // We have to look further.
392      break;
393
394    default:
395      return false;
396    }
397
398    switch (GetLookAheadToken(2).getKind()) {
399    case tok::equal:
400    case tok::comma:
401    case tok::greater:
402    case tok::greatergreater:
403      return true;
404
405    default:
406      return false;
407    }
408  }
409
410  if (Tok.isNot(tok::kw_typename))
411    return false;
412
413  // C++ [temp.param]p2:
414  //   There is no semantic difference between class and typename in a
415  //   template-parameter. typename followed by an unqualified-id
416  //   names a template type parameter. typename followed by a
417  //   qualified-id denotes the type in a non-type
418  //   parameter-declaration.
419  Token Next = NextToken();
420
421  // If we have an identifier, skip over it.
422  if (Next.getKind() == tok::identifier)
423    Next = GetLookAheadToken(2);
424
425  switch (Next.getKind()) {
426  case tok::equal:
427  case tok::comma:
428  case tok::greater:
429  case tok::greatergreater:
430  case tok::ellipsis:
431    return true;
432
433  default:
434    return false;
435  }
436}
437
438/// ParseTemplateParameter - Parse a template-parameter (C++ [temp.param]).
439///
440///       template-parameter: [C++ temp.param]
441///         type-parameter
442///         parameter-declaration
443///
444///       type-parameter: (see below)
445///         'class' ...[opt] identifier[opt]
446///         'class' identifier[opt] '=' type-id
447///         'typename' ...[opt] identifier[opt]
448///         'typename' identifier[opt] '=' type-id
449///         'template' '<' template-parameter-list '>'
450///               'class' ...[opt] identifier[opt]
451///         'template' '<' template-parameter-list '>' 'class' identifier[opt]
452///               = id-expression
453Decl *Parser::ParseTemplateParameter(unsigned Depth, unsigned Position) {
454  if (isStartOfTemplateTypeParameter())
455    return ParseTypeParameter(Depth, Position);
456
457  if (Tok.is(tok::kw_template))
458    return ParseTemplateTemplateParameter(Depth, Position);
459
460  // If it's none of the above, then it must be a parameter declaration.
461  // NOTE: This will pick up errors in the closure of the template parameter
462  // list (e.g., template < ; Check here to implement >> style closures.
463  return ParseNonTypeTemplateParameter(Depth, Position);
464}
465
466/// ParseTypeParameter - Parse a template type parameter (C++ [temp.param]).
467/// Other kinds of template parameters are parsed in
468/// ParseTemplateTemplateParameter and ParseNonTypeTemplateParameter.
469///
470///       type-parameter:     [C++ temp.param]
471///         'class' ...[opt][C++0x] identifier[opt]
472///         'class' identifier[opt] '=' type-id
473///         'typename' ...[opt][C++0x] identifier[opt]
474///         'typename' identifier[opt] '=' type-id
475Decl *Parser::ParseTypeParameter(unsigned Depth, unsigned Position) {
476  assert((Tok.is(tok::kw_class) || Tok.is(tok::kw_typename)) &&
477         "A type-parameter starts with 'class' or 'typename'");
478
479  // Consume the 'class' or 'typename' keyword.
480  bool TypenameKeyword = Tok.is(tok::kw_typename);
481  SourceLocation KeyLoc = ConsumeToken();
482
483  // Grab the ellipsis (if given).
484  bool Ellipsis = false;
485  SourceLocation EllipsisLoc;
486  if (Tok.is(tok::ellipsis)) {
487    Ellipsis = true;
488    EllipsisLoc = ConsumeToken();
489
490    Diag(EllipsisLoc,
491         getLangOpts().CPlusPlus11
492           ? diag::warn_cxx98_compat_variadic_templates
493           : diag::ext_variadic_templates);
494  }
495
496  // Grab the template parameter name (if given)
497  SourceLocation NameLoc;
498  IdentifierInfo* ParamName = 0;
499  if (Tok.is(tok::identifier)) {
500    ParamName = Tok.getIdentifierInfo();
501    NameLoc = ConsumeToken();
502  } else if (Tok.is(tok::equal) || Tok.is(tok::comma) ||
503             Tok.is(tok::greater) || Tok.is(tok::greatergreater)) {
504    // Unnamed template parameter. Don't have to do anything here, just
505    // don't consume this token.
506  } else {
507    Diag(Tok.getLocation(), diag::err_expected_ident);
508    return 0;
509  }
510
511  // Grab a default argument (if available).
512  // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
513  // we introduce the type parameter into the local scope.
514  SourceLocation EqualLoc;
515  ParsedType DefaultArg;
516  if (Tok.is(tok::equal)) {
517    EqualLoc = ConsumeToken();
518    DefaultArg = ParseTypeName(/*Range=*/0,
519                               Declarator::TemplateTypeArgContext).get();
520  }
521
522  return Actions.ActOnTypeParameter(getCurScope(), TypenameKeyword, Ellipsis,
523                                    EllipsisLoc, KeyLoc, ParamName, NameLoc,
524                                    Depth, Position, EqualLoc, DefaultArg);
525}
526
527/// ParseTemplateTemplateParameter - Handle the parsing of template
528/// template parameters.
529///
530///       type-parameter:    [C++ temp.param]
531///         'template' '<' template-parameter-list '>' 'class'
532///                  ...[opt] identifier[opt]
533///         'template' '<' template-parameter-list '>' 'class' identifier[opt]
534///                  = id-expression
535Decl *
536Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
537  assert(Tok.is(tok::kw_template) && "Expected 'template' keyword");
538
539  // Handle the template <...> part.
540  SourceLocation TemplateLoc = ConsumeToken();
541  SmallVector<Decl*,8> TemplateParams;
542  SourceLocation LAngleLoc, RAngleLoc;
543  {
544    ParseScope TemplateParmScope(this, Scope::TemplateParamScope);
545    if (ParseTemplateParameters(Depth + 1, TemplateParams, LAngleLoc,
546                               RAngleLoc)) {
547      return 0;
548    }
549  }
550
551  // Generate a meaningful error if the user forgot to put class before the
552  // identifier, comma, or greater. Provide a fixit if the identifier, comma,
553  // or greater appear immediately or after 'typename' or 'struct'. In the
554  // latter case, replace the keyword with 'class'.
555  if (!Tok.is(tok::kw_class)) {
556    bool Replace = Tok.is(tok::kw_typename) || Tok.is(tok::kw_struct);
557    const Token& Next = Replace ? NextToken() : Tok;
558    if (Next.is(tok::identifier) || Next.is(tok::comma) ||
559        Next.is(tok::greater) || Next.is(tok::greatergreater) ||
560        Next.is(tok::ellipsis))
561      Diag(Tok.getLocation(), diag::err_class_on_template_template_param)
562        << (Replace ? FixItHint::CreateReplacement(Tok.getLocation(), "class")
563                    : FixItHint::CreateInsertion(Tok.getLocation(), "class "));
564    else
565      Diag(Tok.getLocation(), diag::err_class_on_template_template_param);
566
567    if (Replace)
568      ConsumeToken();
569  } else
570    ConsumeToken();
571
572  // Parse the ellipsis, if given.
573  SourceLocation EllipsisLoc;
574  if (Tok.is(tok::ellipsis)) {
575    EllipsisLoc = ConsumeToken();
576
577    Diag(EllipsisLoc,
578         getLangOpts().CPlusPlus11
579           ? diag::warn_cxx98_compat_variadic_templates
580           : diag::ext_variadic_templates);
581  }
582
583  // Get the identifier, if given.
584  SourceLocation NameLoc;
585  IdentifierInfo* ParamName = 0;
586  if (Tok.is(tok::identifier)) {
587    ParamName = Tok.getIdentifierInfo();
588    NameLoc = ConsumeToken();
589  } else if (Tok.is(tok::equal) || Tok.is(tok::comma) ||
590             Tok.is(tok::greater) || Tok.is(tok::greatergreater)) {
591    // Unnamed template parameter. Don't have to do anything here, just
592    // don't consume this token.
593  } else {
594    Diag(Tok.getLocation(), diag::err_expected_ident);
595    return 0;
596  }
597
598  TemplateParameterList *ParamList =
599    Actions.ActOnTemplateParameterList(Depth, SourceLocation(),
600                                       TemplateLoc, LAngleLoc,
601                                       TemplateParams.data(),
602                                       TemplateParams.size(),
603                                       RAngleLoc);
604
605  // Grab a default argument (if available).
606  // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
607  // we introduce the template parameter into the local scope.
608  SourceLocation EqualLoc;
609  ParsedTemplateArgument DefaultArg;
610  if (Tok.is(tok::equal)) {
611    EqualLoc = ConsumeToken();
612    DefaultArg = ParseTemplateTemplateArgument();
613    if (DefaultArg.isInvalid()) {
614      Diag(Tok.getLocation(),
615           diag::err_default_template_template_parameter_not_template);
616      SkipUntil(tok::comma, tok::greater, tok::greatergreater,
617                StopAtSemi | StopBeforeMatch);
618    }
619  }
620
621  return Actions.ActOnTemplateTemplateParameter(getCurScope(), TemplateLoc,
622                                                ParamList, EllipsisLoc,
623                                                ParamName, NameLoc, Depth,
624                                                Position, EqualLoc, DefaultArg);
625}
626
627/// ParseNonTypeTemplateParameter - Handle the parsing of non-type
628/// template parameters (e.g., in "template<int Size> class array;").
629///
630///       template-parameter:
631///         ...
632///         parameter-declaration
633Decl *
634Parser::ParseNonTypeTemplateParameter(unsigned Depth, unsigned Position) {
635  // Parse the declaration-specifiers (i.e., the type).
636  // FIXME: The type should probably be restricted in some way... Not all
637  // declarators (parts of declarators?) are accepted for parameters.
638  DeclSpec DS(AttrFactory);
639  ParseDeclarationSpecifiers(DS);
640
641  // Parse this as a typename.
642  Declarator ParamDecl(DS, Declarator::TemplateParamContext);
643  ParseDeclarator(ParamDecl);
644  if (DS.getTypeSpecType() == DeclSpec::TST_unspecified) {
645    Diag(Tok.getLocation(), diag::err_expected_template_parameter);
646    return 0;
647  }
648
649  // If there is a default value, parse it.
650  // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
651  // we introduce the template parameter into the local scope.
652  SourceLocation EqualLoc;
653  ExprResult DefaultArg;
654  if (Tok.is(tok::equal)) {
655    EqualLoc = ConsumeToken();
656
657    // C++ [temp.param]p15:
658    //   When parsing a default template-argument for a non-type
659    //   template-parameter, the first non-nested > is taken as the
660    //   end of the template-parameter-list rather than a greater-than
661    //   operator.
662    GreaterThanIsOperatorScope G(GreaterThanIsOperator, false);
663    EnterExpressionEvaluationContext Unevaluated(Actions, Sema::Unevaluated);
664
665    DefaultArg = ParseAssignmentExpression();
666    if (DefaultArg.isInvalid())
667      SkipUntil(tok::comma, tok::greater, StopAtSemi | StopBeforeMatch);
668  }
669
670  // Create the parameter.
671  return Actions.ActOnNonTypeTemplateParameter(getCurScope(), ParamDecl,
672                                               Depth, Position, EqualLoc,
673                                               DefaultArg.take());
674}
675
676/// \brief Parses a '>' at the end of a template list.
677///
678/// If this function encounters '>>', '>>>', '>=', or '>>=', it tries
679/// to determine if these tokens were supposed to be a '>' followed by
680/// '>', '>>', '>=', or '>='. It emits an appropriate diagnostic if necessary.
681///
682/// \param RAngleLoc the location of the consumed '>'.
683///
684/// \param ConsumeLastToken if true, the '>' is not consumed.
685///
686/// \returns true, if current token does not start with '>', false otherwise.
687bool Parser::ParseGreaterThanInTemplateList(SourceLocation &RAngleLoc,
688                                            bool ConsumeLastToken) {
689  // What will be left once we've consumed the '>'.
690  tok::TokenKind RemainingToken;
691  const char *ReplacementStr = "> >";
692
693  switch (Tok.getKind()) {
694  default:
695    Diag(Tok.getLocation(), diag::err_expected_greater);
696    return true;
697
698  case tok::greater:
699    // Determine the location of the '>' token. Only consume this token
700    // if the caller asked us to.
701    RAngleLoc = Tok.getLocation();
702    if (ConsumeLastToken)
703      ConsumeToken();
704    return false;
705
706  case tok::greatergreater:
707    RemainingToken = tok::greater;
708    break;
709
710  case tok::greatergreatergreater:
711    RemainingToken = tok::greatergreater;
712    break;
713
714  case tok::greaterequal:
715    RemainingToken = tok::equal;
716    ReplacementStr = "> =";
717    break;
718
719  case tok::greatergreaterequal:
720    RemainingToken = tok::greaterequal;
721    break;
722  }
723
724  // This template-id is terminated by a token which starts with a '>'. Outside
725  // C++11, this is now error recovery, and in C++11, this is error recovery if
726  // the token isn't '>>'.
727
728  RAngleLoc = Tok.getLocation();
729
730  // The source range of the '>>' or '>=' at the start of the token.
731  CharSourceRange ReplacementRange =
732      CharSourceRange::getCharRange(RAngleLoc,
733          Lexer::AdvanceToTokenCharacter(RAngleLoc, 2, PP.getSourceManager(),
734                                         getLangOpts()));
735
736  // A hint to put a space between the '>>'s. In order to make the hint as
737  // clear as possible, we include the characters either side of the space in
738  // the replacement, rather than just inserting a space at SecondCharLoc.
739  FixItHint Hint1 = FixItHint::CreateReplacement(ReplacementRange,
740                                                 ReplacementStr);
741
742  // A hint to put another space after the token, if it would otherwise be
743  // lexed differently.
744  FixItHint Hint2;
745  Token Next = NextToken();
746  if ((RemainingToken == tok::greater ||
747       RemainingToken == tok::greatergreater) &&
748      (Next.is(tok::greater) || Next.is(tok::greatergreater) ||
749       Next.is(tok::greatergreatergreater) || Next.is(tok::equal) ||
750       Next.is(tok::greaterequal) || Next.is(tok::greatergreaterequal) ||
751       Next.is(tok::equalequal)) &&
752      areTokensAdjacent(Tok, Next))
753    Hint2 = FixItHint::CreateInsertion(Next.getLocation(), " ");
754
755  unsigned DiagId = diag::err_two_right_angle_brackets_need_space;
756  if (getLangOpts().CPlusPlus11 && Tok.is(tok::greatergreater))
757    DiagId = diag::warn_cxx98_compat_two_right_angle_brackets;
758  else if (Tok.is(tok::greaterequal))
759    DiagId = diag::err_right_angle_bracket_equal_needs_space;
760  Diag(Tok.getLocation(), DiagId) << Hint1 << Hint2;
761
762  // Strip the initial '>' from the token.
763  if (RemainingToken == tok::equal && Next.is(tok::equal) &&
764      areTokensAdjacent(Tok, Next)) {
765    // Join two adjacent '=' tokens into one, for cases like:
766    //   void (*p)() = f<int>;
767    //   return f<int>==p;
768    ConsumeToken();
769    Tok.setKind(tok::equalequal);
770    Tok.setLength(Tok.getLength() + 1);
771  } else {
772    Tok.setKind(RemainingToken);
773    Tok.setLength(Tok.getLength() - 1);
774  }
775  Tok.setLocation(Lexer::AdvanceToTokenCharacter(RAngleLoc, 1,
776                                                 PP.getSourceManager(),
777                                                 getLangOpts()));
778
779  if (!ConsumeLastToken) {
780    // Since we're not supposed to consume the '>' token, we need to push
781    // this token and revert the current token back to the '>'.
782    PP.EnterToken(Tok);
783    Tok.setKind(tok::greater);
784    Tok.setLength(1);
785    Tok.setLocation(RAngleLoc);
786  }
787  return false;
788}
789
790
791/// \brief Parses a template-id that after the template name has
792/// already been parsed.
793///
794/// This routine takes care of parsing the enclosed template argument
795/// list ('<' template-parameter-list [opt] '>') and placing the
796/// results into a form that can be transferred to semantic analysis.
797///
798/// \param Template the template declaration produced by isTemplateName
799///
800/// \param TemplateNameLoc the source location of the template name
801///
802/// \param SS if non-NULL, the nested-name-specifier preceding the
803/// template name.
804///
805/// \param ConsumeLastToken if true, then we will consume the last
806/// token that forms the template-id. Otherwise, we will leave the
807/// last token in the stream (e.g., so that it can be replaced with an
808/// annotation token).
809bool
810Parser::ParseTemplateIdAfterTemplateName(TemplateTy Template,
811                                         SourceLocation TemplateNameLoc,
812                                         const CXXScopeSpec &SS,
813                                         bool ConsumeLastToken,
814                                         SourceLocation &LAngleLoc,
815                                         TemplateArgList &TemplateArgs,
816                                         SourceLocation &RAngleLoc) {
817  assert(Tok.is(tok::less) && "Must have already parsed the template-name");
818
819  // Consume the '<'.
820  LAngleLoc = ConsumeToken();
821
822  // Parse the optional template-argument-list.
823  bool Invalid = false;
824  {
825    GreaterThanIsOperatorScope G(GreaterThanIsOperator, false);
826    if (Tok.isNot(tok::greater) && Tok.isNot(tok::greatergreater))
827      Invalid = ParseTemplateArgumentList(TemplateArgs);
828
829    if (Invalid) {
830      // Try to find the closing '>'.
831      if (ConsumeLastToken)
832        SkipUntil(tok::greater, StopAtSemi);
833      else
834        SkipUntil(tok::greater, StopAtSemi | StopBeforeMatch);
835      return true;
836    }
837  }
838
839  return ParseGreaterThanInTemplateList(RAngleLoc, ConsumeLastToken);
840}
841
842/// \brief Replace the tokens that form a simple-template-id with an
843/// annotation token containing the complete template-id.
844///
845/// The first token in the stream must be the name of a template that
846/// is followed by a '<'. This routine will parse the complete
847/// simple-template-id and replace the tokens with a single annotation
848/// token with one of two different kinds: if the template-id names a
849/// type (and \p AllowTypeAnnotation is true), the annotation token is
850/// a type annotation that includes the optional nested-name-specifier
851/// (\p SS). Otherwise, the annotation token is a template-id
852/// annotation that does not include the optional
853/// nested-name-specifier.
854///
855/// \param Template  the declaration of the template named by the first
856/// token (an identifier), as returned from \c Action::isTemplateName().
857///
858/// \param TNK the kind of template that \p Template
859/// refers to, as returned from \c Action::isTemplateName().
860///
861/// \param SS if non-NULL, the nested-name-specifier that precedes
862/// this template name.
863///
864/// \param TemplateKWLoc if valid, specifies that this template-id
865/// annotation was preceded by the 'template' keyword and gives the
866/// location of that keyword. If invalid (the default), then this
867/// template-id was not preceded by a 'template' keyword.
868///
869/// \param AllowTypeAnnotation if true (the default), then a
870/// simple-template-id that refers to a class template, template
871/// template parameter, or other template that produces a type will be
872/// replaced with a type annotation token. Otherwise, the
873/// simple-template-id is always replaced with a template-id
874/// annotation token.
875///
876/// If an unrecoverable parse error occurs and no annotation token can be
877/// formed, this function returns true.
878///
879bool Parser::AnnotateTemplateIdToken(TemplateTy Template, TemplateNameKind TNK,
880                                     CXXScopeSpec &SS,
881                                     SourceLocation TemplateKWLoc,
882                                     UnqualifiedId &TemplateName,
883                                     bool AllowTypeAnnotation) {
884  assert(getLangOpts().CPlusPlus && "Can only annotate template-ids in C++");
885  assert(Template && Tok.is(tok::less) &&
886         "Parser isn't at the beginning of a template-id");
887
888  // Consume the template-name.
889  SourceLocation TemplateNameLoc = TemplateName.getSourceRange().getBegin();
890
891  // Parse the enclosed template argument list.
892  SourceLocation LAngleLoc, RAngleLoc;
893  TemplateArgList TemplateArgs;
894  bool Invalid = ParseTemplateIdAfterTemplateName(Template,
895                                                  TemplateNameLoc,
896                                                  SS, false, LAngleLoc,
897                                                  TemplateArgs,
898                                                  RAngleLoc);
899
900  if (Invalid) {
901    // If we failed to parse the template ID but skipped ahead to a >, we're not
902    // going to be able to form a token annotation.  Eat the '>' if present.
903    if (Tok.is(tok::greater))
904      ConsumeToken();
905    return true;
906  }
907
908  ASTTemplateArgsPtr TemplateArgsPtr(TemplateArgs);
909
910  // Build the annotation token.
911  if (TNK == TNK_Type_template && AllowTypeAnnotation) {
912    TypeResult Type
913      = Actions.ActOnTemplateIdType(SS, TemplateKWLoc,
914                                    Template, TemplateNameLoc,
915                                    LAngleLoc, TemplateArgsPtr, RAngleLoc);
916    if (Type.isInvalid()) {
917      // If we failed to parse the template ID but skipped ahead to a >, we're not
918      // going to be able to form a token annotation.  Eat the '>' if present.
919      if (Tok.is(tok::greater))
920        ConsumeToken();
921      return true;
922    }
923
924    Tok.setKind(tok::annot_typename);
925    setTypeAnnotation(Tok, Type.get());
926    if (SS.isNotEmpty())
927      Tok.setLocation(SS.getBeginLoc());
928    else if (TemplateKWLoc.isValid())
929      Tok.setLocation(TemplateKWLoc);
930    else
931      Tok.setLocation(TemplateNameLoc);
932  } else {
933    // Build a template-id annotation token that can be processed
934    // later.
935    Tok.setKind(tok::annot_template_id);
936    TemplateIdAnnotation *TemplateId
937      = TemplateIdAnnotation::Allocate(TemplateArgs.size(), TemplateIds);
938    TemplateId->TemplateNameLoc = TemplateNameLoc;
939    if (TemplateName.getKind() == UnqualifiedId::IK_Identifier) {
940      TemplateId->Name = TemplateName.Identifier;
941      TemplateId->Operator = OO_None;
942    } else {
943      TemplateId->Name = 0;
944      TemplateId->Operator = TemplateName.OperatorFunctionId.Operator;
945    }
946    TemplateId->SS = SS;
947    TemplateId->TemplateKWLoc = TemplateKWLoc;
948    TemplateId->Template = Template;
949    TemplateId->Kind = TNK;
950    TemplateId->LAngleLoc = LAngleLoc;
951    TemplateId->RAngleLoc = RAngleLoc;
952    ParsedTemplateArgument *Args = TemplateId->getTemplateArgs();
953    for (unsigned Arg = 0, ArgEnd = TemplateArgs.size(); Arg != ArgEnd; ++Arg)
954      Args[Arg] = ParsedTemplateArgument(TemplateArgs[Arg]);
955    Tok.setAnnotationValue(TemplateId);
956    if (TemplateKWLoc.isValid())
957      Tok.setLocation(TemplateKWLoc);
958    else
959      Tok.setLocation(TemplateNameLoc);
960  }
961
962  // Common fields for the annotation token
963  Tok.setAnnotationEndLoc(RAngleLoc);
964
965  // In case the tokens were cached, have Preprocessor replace them with the
966  // annotation token.
967  PP.AnnotateCachedTokens(Tok);
968  return false;
969}
970
971/// \brief Replaces a template-id annotation token with a type
972/// annotation token.
973///
974/// If there was a failure when forming the type from the template-id,
975/// a type annotation token will still be created, but will have a
976/// NULL type pointer to signify an error.
977void Parser::AnnotateTemplateIdTokenAsType() {
978  assert(Tok.is(tok::annot_template_id) && "Requires template-id tokens");
979
980  TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
981  assert((TemplateId->Kind == TNK_Type_template ||
982          TemplateId->Kind == TNK_Dependent_template_name) &&
983         "Only works for type and dependent templates");
984
985  ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
986                                     TemplateId->NumArgs);
987
988  TypeResult Type
989    = Actions.ActOnTemplateIdType(TemplateId->SS,
990                                  TemplateId->TemplateKWLoc,
991                                  TemplateId->Template,
992                                  TemplateId->TemplateNameLoc,
993                                  TemplateId->LAngleLoc,
994                                  TemplateArgsPtr,
995                                  TemplateId->RAngleLoc);
996  // Create the new "type" annotation token.
997  Tok.setKind(tok::annot_typename);
998  setTypeAnnotation(Tok, Type.isInvalid() ? ParsedType() : Type.get());
999  if (TemplateId->SS.isNotEmpty()) // it was a C++ qualified type name.
1000    Tok.setLocation(TemplateId->SS.getBeginLoc());
1001  // End location stays the same
1002
1003  // Replace the template-id annotation token, and possible the scope-specifier
1004  // that precedes it, with the typename annotation token.
1005  PP.AnnotateCachedTokens(Tok);
1006}
1007
1008/// \brief Determine whether the given token can end a template argument.
1009static bool isEndOfTemplateArgument(Token Tok) {
1010  return Tok.is(tok::comma) || Tok.is(tok::greater) ||
1011         Tok.is(tok::greatergreater);
1012}
1013
1014/// \brief Parse a C++ template template argument.
1015ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() {
1016  if (!Tok.is(tok::identifier) && !Tok.is(tok::coloncolon) &&
1017      !Tok.is(tok::annot_cxxscope))
1018    return ParsedTemplateArgument();
1019
1020  // C++0x [temp.arg.template]p1:
1021  //   A template-argument for a template template-parameter shall be the name
1022  //   of a class template or an alias template, expressed as id-expression.
1023  //
1024  // We parse an id-expression that refers to a class template or alias
1025  // template. The grammar we parse is:
1026  //
1027  //   nested-name-specifier[opt] template[opt] identifier ...[opt]
1028  //
1029  // followed by a token that terminates a template argument, such as ',',
1030  // '>', or (in some cases) '>>'.
1031  CXXScopeSpec SS; // nested-name-specifier, if present
1032  ParseOptionalCXXScopeSpecifier(SS, ParsedType(),
1033                                 /*EnteringContext=*/false);
1034
1035  ParsedTemplateArgument Result;
1036  SourceLocation EllipsisLoc;
1037  if (SS.isSet() && Tok.is(tok::kw_template)) {
1038    // Parse the optional 'template' keyword following the
1039    // nested-name-specifier.
1040    SourceLocation TemplateKWLoc = ConsumeToken();
1041
1042    if (Tok.is(tok::identifier)) {
1043      // We appear to have a dependent template name.
1044      UnqualifiedId Name;
1045      Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
1046      ConsumeToken(); // the identifier
1047
1048      // Parse the ellipsis.
1049      if (Tok.is(tok::ellipsis))
1050        EllipsisLoc = ConsumeToken();
1051
1052      // If the next token signals the end of a template argument,
1053      // then we have a dependent template name that could be a template
1054      // template argument.
1055      TemplateTy Template;
1056      if (isEndOfTemplateArgument(Tok) &&
1057          Actions.ActOnDependentTemplateName(getCurScope(),
1058                                             SS, TemplateKWLoc, Name,
1059                                             /*ObjectType=*/ ParsedType(),
1060                                             /*EnteringContext=*/false,
1061                                             Template))
1062        Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
1063    }
1064  } else if (Tok.is(tok::identifier)) {
1065    // We may have a (non-dependent) template name.
1066    TemplateTy Template;
1067    UnqualifiedId Name;
1068    Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
1069    ConsumeToken(); // the identifier
1070
1071    // Parse the ellipsis.
1072    if (Tok.is(tok::ellipsis))
1073      EllipsisLoc = ConsumeToken();
1074
1075    if (isEndOfTemplateArgument(Tok)) {
1076      bool MemberOfUnknownSpecialization;
1077      TemplateNameKind TNK = Actions.isTemplateName(getCurScope(), SS,
1078                                               /*hasTemplateKeyword=*/false,
1079                                                    Name,
1080                                               /*ObjectType=*/ ParsedType(),
1081                                                    /*EnteringContext=*/false,
1082                                                    Template,
1083                                                MemberOfUnknownSpecialization);
1084      if (TNK == TNK_Dependent_template_name || TNK == TNK_Type_template) {
1085        // We have an id-expression that refers to a class template or
1086        // (C++0x) alias template.
1087        Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
1088      }
1089    }
1090  }
1091
1092  // If this is a pack expansion, build it as such.
1093  if (EllipsisLoc.isValid() && !Result.isInvalid())
1094    Result = Actions.ActOnPackExpansion(Result, EllipsisLoc);
1095
1096  return Result;
1097}
1098
1099/// ParseTemplateArgument - Parse a C++ template argument (C++ [temp.names]).
1100///
1101///       template-argument: [C++ 14.2]
1102///         constant-expression
1103///         type-id
1104///         id-expression
1105ParsedTemplateArgument Parser::ParseTemplateArgument() {
1106  // C++ [temp.arg]p2:
1107  //   In a template-argument, an ambiguity between a type-id and an
1108  //   expression is resolved to a type-id, regardless of the form of
1109  //   the corresponding template-parameter.
1110  //
1111  // Therefore, we initially try to parse a type-id.
1112  if (isCXXTypeId(TypeIdAsTemplateArgument)) {
1113    SourceLocation Loc = Tok.getLocation();
1114    TypeResult TypeArg = ParseTypeName(/*Range=*/0,
1115                                       Declarator::TemplateTypeArgContext);
1116    if (TypeArg.isInvalid())
1117      return ParsedTemplateArgument();
1118
1119    return ParsedTemplateArgument(ParsedTemplateArgument::Type,
1120                                  TypeArg.get().getAsOpaquePtr(),
1121                                  Loc);
1122  }
1123
1124  // Try to parse a template template argument.
1125  {
1126    TentativeParsingAction TPA(*this);
1127
1128    ParsedTemplateArgument TemplateTemplateArgument
1129      = ParseTemplateTemplateArgument();
1130    if (!TemplateTemplateArgument.isInvalid()) {
1131      TPA.Commit();
1132      return TemplateTemplateArgument;
1133    }
1134
1135    // Revert this tentative parse to parse a non-type template argument.
1136    TPA.Revert();
1137  }
1138
1139  // Parse a non-type template argument.
1140  SourceLocation Loc = Tok.getLocation();
1141  ExprResult ExprArg = ParseConstantExpression(MaybeTypeCast);
1142  if (ExprArg.isInvalid() || !ExprArg.get())
1143    return ParsedTemplateArgument();
1144
1145  return ParsedTemplateArgument(ParsedTemplateArgument::NonType,
1146                                ExprArg.release(), Loc);
1147}
1148
1149/// \brief Determine whether the current tokens can only be parsed as a
1150/// template argument list (starting with the '<') and never as a '<'
1151/// expression.
1152bool Parser::IsTemplateArgumentList(unsigned Skip) {
1153  struct AlwaysRevertAction : TentativeParsingAction {
1154    AlwaysRevertAction(Parser &P) : TentativeParsingAction(P) { }
1155    ~AlwaysRevertAction() { Revert(); }
1156  } Tentative(*this);
1157
1158  while (Skip) {
1159    ConsumeToken();
1160    --Skip;
1161  }
1162
1163  // '<'
1164  if (!Tok.is(tok::less))
1165    return false;
1166  ConsumeToken();
1167
1168  // An empty template argument list.
1169  if (Tok.is(tok::greater))
1170    return true;
1171
1172  // See whether we have declaration specifiers, which indicate a type.
1173  while (isCXXDeclarationSpecifier() == TPResult::True())
1174    ConsumeToken();
1175
1176  // If we have a '>' or a ',' then this is a template argument list.
1177  return Tok.is(tok::greater) || Tok.is(tok::comma);
1178}
1179
1180/// ParseTemplateArgumentList - Parse a C++ template-argument-list
1181/// (C++ [temp.names]). Returns true if there was an error.
1182///
1183///       template-argument-list: [C++ 14.2]
1184///         template-argument
1185///         template-argument-list ',' template-argument
1186bool
1187Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs) {
1188  // Template argument lists are constant-evaluation contexts.
1189  EnterExpressionEvaluationContext EvalContext(Actions,Sema::ConstantEvaluated);
1190
1191  while (true) {
1192    ParsedTemplateArgument Arg = ParseTemplateArgument();
1193    if (Tok.is(tok::ellipsis)) {
1194      SourceLocation EllipsisLoc  = ConsumeToken();
1195      Arg = Actions.ActOnPackExpansion(Arg, EllipsisLoc);
1196    }
1197
1198    if (Arg.isInvalid()) {
1199      SkipUntil(tok::comma, tok::greater, StopAtSemi | StopBeforeMatch);
1200      return true;
1201    }
1202
1203    // Save this template argument.
1204    TemplateArgs.push_back(Arg);
1205
1206    // If the next token is a comma, consume it and keep reading
1207    // arguments.
1208    if (Tok.isNot(tok::comma)) break;
1209
1210    // Consume the comma.
1211    ConsumeToken();
1212  }
1213
1214  return false;
1215}
1216
1217/// \brief Parse a C++ explicit template instantiation
1218/// (C++ [temp.explicit]).
1219///
1220///       explicit-instantiation:
1221///         'extern' [opt] 'template' declaration
1222///
1223/// Note that the 'extern' is a GNU extension and C++11 feature.
1224Decl *Parser::ParseExplicitInstantiation(unsigned Context,
1225                                         SourceLocation ExternLoc,
1226                                         SourceLocation TemplateLoc,
1227                                         SourceLocation &DeclEnd,
1228                                         AccessSpecifier AS) {
1229  // This isn't really required here.
1230  ParsingDeclRAIIObject
1231    ParsingTemplateParams(*this, ParsingDeclRAIIObject::NoParent);
1232
1233  return ParseSingleDeclarationAfterTemplate(Context,
1234                                             ParsedTemplateInfo(ExternLoc,
1235                                                                TemplateLoc),
1236                                             ParsingTemplateParams,
1237                                             DeclEnd, AS);
1238}
1239
1240SourceRange Parser::ParsedTemplateInfo::getSourceRange() const {
1241  if (TemplateParams)
1242    return getTemplateParamsRange(TemplateParams->data(),
1243                                  TemplateParams->size());
1244
1245  SourceRange R(TemplateLoc);
1246  if (ExternLoc.isValid())
1247    R.setBegin(ExternLoc);
1248  return R;
1249}
1250
1251void Parser::LateTemplateParserCallback(void *P, LateParsedTemplate &LPT) {
1252  ((Parser *)P)->ParseLateTemplatedFuncDef(LPT);
1253}
1254
1255/// \brief Late parse a C++ function template in Microsoft mode.
1256void Parser::ParseLateTemplatedFuncDef(LateParsedTemplate &LPT) {
1257  if (!LPT.D)
1258     return;
1259
1260  // Get the FunctionDecl.
1261  FunctionTemplateDecl *FunTmplD = dyn_cast<FunctionTemplateDecl>(LPT.D);
1262  FunctionDecl *FunD =
1263      FunTmplD ? FunTmplD->getTemplatedDecl() : cast<FunctionDecl>(LPT.D);
1264  // Track template parameter depth.
1265  TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
1266
1267  // To restore the context after late parsing.
1268  Sema::ContextRAII GlobalSavedContext(Actions, Actions.CurContext);
1269
1270  SmallVector<ParseScope*, 4> TemplateParamScopeStack;
1271
1272  // Get the list of DeclContexts to reenter.
1273  SmallVector<DeclContext*, 4> DeclContextsToReenter;
1274  DeclContext *DD = FunD->getLexicalParent();
1275  while (DD && !DD->isTranslationUnit()) {
1276    DeclContextsToReenter.push_back(DD);
1277    DD = DD->getLexicalParent();
1278  }
1279
1280  // Reenter template scopes from outermost to innermost.
1281  SmallVectorImpl<DeclContext *>::reverse_iterator II =
1282      DeclContextsToReenter.rbegin();
1283  for (; II != DeclContextsToReenter.rend(); ++II) {
1284    if (ClassTemplatePartialSpecializationDecl *MD =
1285            dyn_cast_or_null<ClassTemplatePartialSpecializationDecl>(*II)) {
1286      TemplateParamScopeStack.push_back(
1287          new ParseScope(this, Scope::TemplateParamScope));
1288      Actions.ActOnReenterTemplateScope(getCurScope(), MD);
1289      ++CurTemplateDepthTracker;
1290    } else if (CXXRecordDecl *MD = dyn_cast_or_null<CXXRecordDecl>(*II)) {
1291      bool IsClassTemplate = MD->getDescribedClassTemplate() != 0;
1292      TemplateParamScopeStack.push_back(
1293          new ParseScope(this, Scope::TemplateParamScope,
1294                        /*ManageScope*/IsClassTemplate));
1295      Actions.ActOnReenterTemplateScope(getCurScope(),
1296                                        MD->getDescribedClassTemplate());
1297      if (IsClassTemplate)
1298        ++CurTemplateDepthTracker;
1299    }
1300    TemplateParamScopeStack.push_back(new ParseScope(this, Scope::DeclScope));
1301    Actions.PushDeclContext(Actions.getCurScope(), *II);
1302  }
1303  TemplateParamScopeStack.push_back(
1304      new ParseScope(this, Scope::TemplateParamScope));
1305
1306  DeclaratorDecl *Declarator = dyn_cast<DeclaratorDecl>(FunD);
1307  if (Declarator && Declarator->getNumTemplateParameterLists() != 0) {
1308    Actions.ActOnReenterDeclaratorTemplateScope(getCurScope(), Declarator);
1309    ++CurTemplateDepthTracker;
1310  }
1311  Actions.ActOnReenterTemplateScope(getCurScope(), LPT.D);
1312  ++CurTemplateDepthTracker;
1313
1314  assert(!LPT.Toks.empty() && "Empty body!");
1315
1316  // Append the current token at the end of the new token stream so that it
1317  // doesn't get lost.
1318  LPT.Toks.push_back(Tok);
1319  PP.EnterTokenStream(LPT.Toks.data(), LPT.Toks.size(), true, false);
1320
1321  // Consume the previously pushed token.
1322  ConsumeAnyToken(/*ConsumeCodeCompletionTok=*/true);
1323  assert((Tok.is(tok::l_brace) || Tok.is(tok::colon) || Tok.is(tok::kw_try))
1324         && "Inline method not starting with '{', ':' or 'try'");
1325
1326  // Parse the method body. Function body parsing code is similar enough
1327  // to be re-used for method bodies as well.
1328  ParseScope FnScope(this, Scope::FnScope|Scope::DeclScope);
1329
1330  // Recreate the containing function DeclContext.
1331  Sema::ContextRAII FunctionSavedContext(Actions, Actions.getContainingDC(FunD));
1332
1333  Actions.ActOnStartOfFunctionDef(getCurScope(), FunD);
1334
1335  if (Tok.is(tok::kw_try)) {
1336    ParseFunctionTryBlock(LPT.D, FnScope);
1337  } else {
1338    if (Tok.is(tok::colon))
1339      ParseConstructorInitializer(LPT.D);
1340    else
1341      Actions.ActOnDefaultCtorInitializers(LPT.D);
1342
1343    if (Tok.is(tok::l_brace)) {
1344      assert((!FunTmplD || FunTmplD->getTemplateParameters()->getDepth() <
1345                               TemplateParameterDepth) &&
1346             "TemplateParameterDepth should be greater than the depth of "
1347             "current template being instantiated!");
1348      ParseFunctionStatementBody(LPT.D, FnScope);
1349      Actions.UnmarkAsLateParsedTemplate(FunD);
1350    } else
1351      Actions.ActOnFinishFunctionBody(LPT.D, 0);
1352  }
1353
1354  // Exit scopes.
1355  FnScope.Exit();
1356  SmallVectorImpl<ParseScope *>::reverse_iterator I =
1357   TemplateParamScopeStack.rbegin();
1358  for (; I != TemplateParamScopeStack.rend(); ++I)
1359    delete *I;
1360}
1361
1362/// \brief Lex a delayed template function for late parsing.
1363void Parser::LexTemplateFunctionForLateParsing(CachedTokens &Toks) {
1364  tok::TokenKind kind = Tok.getKind();
1365  if (!ConsumeAndStoreFunctionPrologue(Toks)) {
1366    // Consume everything up to (and including) the matching right brace.
1367    ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
1368  }
1369
1370  // If we're in a function-try-block, we need to store all the catch blocks.
1371  if (kind == tok::kw_try) {
1372    while (Tok.is(tok::kw_catch)) {
1373      ConsumeAndStoreUntil(tok::l_brace, Toks, /*StopAtSemi=*/false);
1374      ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
1375    }
1376  }
1377}
1378