ParseTemplate.cpp revision 221345
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 "clang/Parse/ParseDiagnostic.h"
16#include "clang/Sema/DeclSpec.h"
17#include "clang/Sema/ParsedTemplate.h"
18#include "clang/Sema/Scope.h"
19#include "RAIIObjectsForParser.h"
20#include "clang/AST/DeclTemplate.h"
21#include "clang/AST/ASTConsumer.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  if (Tok.is(tok::kw_template) && NextToken().isNot(tok::less))
31    return ParseExplicitInstantiation(SourceLocation(), ConsumeToken(),
32                                      DeclEnd);
33
34  return ParseTemplateDeclarationOrSpecialization(Context, DeclEnd, AS);
35}
36
37/// \brief RAII class that manages the template parameter depth.
38namespace {
39  class TemplateParameterDepthCounter {
40    unsigned &Depth;
41    unsigned AddedLevels;
42
43  public:
44    explicit TemplateParameterDepthCounter(unsigned &Depth)
45      : Depth(Depth), AddedLevels(0) { }
46
47    ~TemplateParameterDepthCounter() {
48      Depth -= AddedLevels;
49    }
50
51    void operator++() {
52      ++Depth;
53      ++AddedLevels;
54    }
55
56    operator unsigned() const { return Depth; }
57  };
58}
59
60/// \brief Parse a template declaration or an explicit specialization.
61///
62/// Template declarations include one or more template parameter lists
63/// and either the function or class template declaration. Explicit
64/// specializations contain one or more 'template < >' prefixes
65/// followed by a (possibly templated) declaration. Since the
66/// syntactic form of both features is nearly identical, we parse all
67/// of the template headers together and let semantic analysis sort
68/// the declarations from the explicit specializations.
69///
70///       template-declaration: [C++ temp]
71///         'export'[opt] 'template' '<' template-parameter-list '>' declaration
72///
73///       explicit-specialization: [ C++ temp.expl.spec]
74///         'template' '<' '>' declaration
75Decl *
76Parser::ParseTemplateDeclarationOrSpecialization(unsigned Context,
77                                                 SourceLocation &DeclEnd,
78                                                 AccessSpecifier AS) {
79  assert((Tok.is(tok::kw_export) || Tok.is(tok::kw_template)) &&
80         "Token does not start a template declaration.");
81
82  // Enter template-parameter scope.
83  ParseScope TemplateParmScope(this, Scope::TemplateParamScope);
84
85  // Tell the action that names should be checked in the context of
86  // the declaration to come.
87  ParsingDeclRAIIObject ParsingTemplateParams(*this);
88
89  // Parse multiple levels of template headers within this template
90  // parameter scope, e.g.,
91  //
92  //   template<typename T>
93  //     template<typename U>
94  //       class A<T>::B { ... };
95  //
96  // We parse multiple levels non-recursively so that we can build a
97  // single data structure containing all of the template parameter
98  // lists to easily differentiate between the case above and:
99  //
100  //   template<typename T>
101  //   class A {
102  //     template<typename U> class B;
103  //   };
104  //
105  // In the first case, the action for declaring A<T>::B receives
106  // both template parameter lists. In the second case, the action for
107  // defining A<T>::B receives just the inner template parameter list
108  // (and retrieves the outer template parameter list from its
109  // context).
110  bool isSpecialization = true;
111  bool LastParamListWasEmpty = false;
112  TemplateParameterLists ParamLists;
113  TemplateParameterDepthCounter Depth(TemplateParameterDepth);
114  do {
115    // Consume the 'export', if any.
116    SourceLocation ExportLoc;
117    if (Tok.is(tok::kw_export)) {
118      ExportLoc = ConsumeToken();
119    }
120
121    // Consume the 'template', which should be here.
122    SourceLocation TemplateLoc;
123    if (Tok.is(tok::kw_template)) {
124      TemplateLoc = ConsumeToken();
125    } else {
126      Diag(Tok.getLocation(), diag::err_expected_template);
127      return 0;
128    }
129
130    // Parse the '<' template-parameter-list '>'
131    SourceLocation LAngleLoc, RAngleLoc;
132    llvm::SmallVector<Decl*, 4> TemplateParams;
133    if (ParseTemplateParameters(Depth, TemplateParams, LAngleLoc,
134                                RAngleLoc)) {
135      // Skip until the semi-colon or a }.
136      SkipUntil(tok::r_brace, true, true);
137      if (Tok.is(tok::semi))
138        ConsumeToken();
139      return 0;
140    }
141
142    ParamLists.push_back(
143      Actions.ActOnTemplateParameterList(Depth, ExportLoc,
144                                         TemplateLoc, LAngleLoc,
145                                         TemplateParams.data(),
146                                         TemplateParams.size(), RAngleLoc));
147
148    if (!TemplateParams.empty()) {
149      isSpecialization = false;
150      ++Depth;
151    } else {
152      LastParamListWasEmpty = true;
153    }
154  } while (Tok.is(tok::kw_export) || Tok.is(tok::kw_template));
155
156  // Parse the actual template declaration.
157  return ParseSingleDeclarationAfterTemplate(Context,
158                                             ParsedTemplateInfo(&ParamLists,
159                                                             isSpecialization,
160                                                         LastParamListWasEmpty),
161                                             ParsingTemplateParams,
162                                             DeclEnd, AS);
163}
164
165/// \brief Parse a single declaration that declares a template,
166/// template specialization, or explicit instantiation of a template.
167///
168/// \param TemplateParams if non-NULL, the template parameter lists
169/// that preceded this declaration. In this case, the declaration is a
170/// template declaration, out-of-line definition of a template, or an
171/// explicit template specialization. When NULL, the declaration is an
172/// explicit template instantiation.
173///
174/// \param TemplateLoc when TemplateParams is NULL, the location of
175/// the 'template' keyword that indicates that we have an explicit
176/// template instantiation.
177///
178/// \param DeclEnd will receive the source location of the last token
179/// within this declaration.
180///
181/// \param AS the access specifier associated with this
182/// declaration. Will be AS_none for namespace-scope declarations.
183///
184/// \returns the new declaration.
185Decl *
186Parser::ParseSingleDeclarationAfterTemplate(
187                                       unsigned Context,
188                                       const ParsedTemplateInfo &TemplateInfo,
189                                       ParsingDeclRAIIObject &DiagsFromTParams,
190                                       SourceLocation &DeclEnd,
191                                       AccessSpecifier AS) {
192  assert(TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate &&
193         "Template information required");
194
195  if (Context == Declarator::MemberContext) {
196    // We are parsing a member template.
197    ParseCXXClassMemberDeclaration(AS, TemplateInfo, &DiagsFromTParams);
198    return 0;
199  }
200
201  ParsedAttributesWithRange prefixAttrs(AttrFactory);
202  MaybeParseCXX0XAttributes(prefixAttrs);
203
204  if (Tok.is(tok::kw_using))
205    return ParseUsingDirectiveOrDeclaration(Context, TemplateInfo, DeclEnd,
206                                            prefixAttrs);
207
208  // Parse the declaration specifiers, stealing the accumulated
209  // diagnostics from the template parameters.
210  ParsingDeclSpec DS(*this, &DiagsFromTParams);
211
212  DS.takeAttributesFrom(prefixAttrs);
213
214  ParseDeclarationSpecifiers(DS, TemplateInfo, AS,
215                             getDeclSpecContextFromDeclaratorContext(Context));
216
217  if (Tok.is(tok::semi)) {
218    DeclEnd = ConsumeToken();
219    Decl *Decl = Actions.ParsedFreeStandingDeclSpec(getCurScope(), AS, DS);
220    DS.complete(Decl);
221    return Decl;
222  }
223
224  // Parse the declarator.
225  ParsingDeclarator DeclaratorInfo(*this, DS, (Declarator::TheContext)Context);
226  ParseDeclarator(DeclaratorInfo);
227  // Error parsing the declarator?
228  if (!DeclaratorInfo.hasName()) {
229    // If so, skip until the semi-colon or a }.
230    SkipUntil(tok::r_brace, true, true);
231    if (Tok.is(tok::semi))
232      ConsumeToken();
233    return 0;
234  }
235
236  // If we have a declaration or declarator list, handle it.
237  if (isDeclarationAfterDeclarator()) {
238    // Parse this declaration.
239    Decl *ThisDecl = ParseDeclarationAfterDeclarator(DeclaratorInfo,
240                                                     TemplateInfo);
241
242    if (Tok.is(tok::comma)) {
243      Diag(Tok, diag::err_multiple_template_declarators)
244        << (int)TemplateInfo.Kind;
245      SkipUntil(tok::semi, true, false);
246      return ThisDecl;
247    }
248
249    // Eat the semi colon after the declaration.
250    ExpectAndConsume(tok::semi, diag::err_expected_semi_declaration);
251    DeclaratorInfo.complete(ThisDecl);
252    return ThisDecl;
253  }
254
255  if (DeclaratorInfo.isFunctionDeclarator() &&
256      isStartOfFunctionDefinition(DeclaratorInfo)) {
257    if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) {
258      Diag(Tok, diag::err_function_declared_typedef);
259
260      if (Tok.is(tok::l_brace)) {
261        // This recovery skips the entire function body. It would be nice
262        // to simply call ParseFunctionDefinition() below, however Sema
263        // assumes the declarator represents a function, not a typedef.
264        ConsumeBrace();
265        SkipUntil(tok::r_brace, true);
266      } else {
267        SkipUntil(tok::semi);
268      }
269      return 0;
270    }
271    return ParseFunctionDefinition(DeclaratorInfo, TemplateInfo);
272  }
273
274  if (DeclaratorInfo.isFunctionDeclarator())
275    Diag(Tok, diag::err_expected_fn_body);
276  else
277    Diag(Tok, diag::err_invalid_token_after_toplevel_declarator);
278  SkipUntil(tok::semi);
279  return 0;
280}
281
282/// ParseTemplateParameters - Parses a template-parameter-list enclosed in
283/// angle brackets. Depth is the depth of this template-parameter-list, which
284/// is the number of template headers directly enclosing this template header.
285/// TemplateParams is the current list of template parameters we're building.
286/// The template parameter we parse will be added to this list. LAngleLoc and
287/// RAngleLoc will receive the positions of the '<' and '>', respectively,
288/// that enclose this template parameter list.
289///
290/// \returns true if an error occurred, false otherwise.
291bool Parser::ParseTemplateParameters(unsigned Depth,
292                               llvm::SmallVectorImpl<Decl*> &TemplateParams,
293                                     SourceLocation &LAngleLoc,
294                                     SourceLocation &RAngleLoc) {
295  // Get the template parameter list.
296  if (!Tok.is(tok::less)) {
297    Diag(Tok.getLocation(), diag::err_expected_less_after) << "template";
298    return true;
299  }
300  LAngleLoc = ConsumeToken();
301
302  // Try to parse the template parameter list.
303  if (Tok.is(tok::greater))
304    RAngleLoc = ConsumeToken();
305  else if (ParseTemplateParameterList(Depth, TemplateParams)) {
306    if (!Tok.is(tok::greater)) {
307      Diag(Tok.getLocation(), diag::err_expected_greater);
308      return true;
309    }
310    RAngleLoc = ConsumeToken();
311  }
312  return false;
313}
314
315/// ParseTemplateParameterList - Parse a template parameter list. If
316/// the parsing fails badly (i.e., closing bracket was left out), this
317/// will try to put the token stream in a reasonable position (closing
318/// a statement, etc.) and return false.
319///
320///       template-parameter-list:    [C++ temp]
321///         template-parameter
322///         template-parameter-list ',' template-parameter
323bool
324Parser::ParseTemplateParameterList(unsigned Depth,
325                             llvm::SmallVectorImpl<Decl*> &TemplateParams) {
326  while (1) {
327    if (Decl *TmpParam
328          = ParseTemplateParameter(Depth, TemplateParams.size())) {
329      TemplateParams.push_back(TmpParam);
330    } else {
331      // If we failed to parse a template parameter, skip until we find
332      // a comma or closing brace.
333      SkipUntil(tok::comma, tok::greater, true, true);
334    }
335
336    // Did we find a comma or the end of the template parmeter list?
337    if (Tok.is(tok::comma)) {
338      ConsumeToken();
339    } else if (Tok.is(tok::greater)) {
340      // Don't consume this... that's done by template parser.
341      break;
342    } else {
343      // Somebody probably forgot to close the template. Skip ahead and
344      // try to get out of the expression. This error is currently
345      // subsumed by whatever goes on in ParseTemplateParameter.
346      // TODO: This could match >>, and it would be nice to avoid those
347      // silly errors with template <vec<T>>.
348      Diag(Tok.getLocation(), diag::err_expected_comma_greater);
349      SkipUntil(tok::greater, true, true);
350      return false;
351    }
352  }
353  return true;
354}
355
356/// \brief Determine whether the parser is at the start of a template
357/// type parameter.
358bool Parser::isStartOfTemplateTypeParameter() {
359  if (Tok.is(tok::kw_class)) {
360    // "class" may be the start of an elaborated-type-specifier or a
361    // type-parameter. Per C++ [temp.param]p3, we prefer the type-parameter.
362    switch (NextToken().getKind()) {
363    case tok::equal:
364    case tok::comma:
365    case tok::greater:
366    case tok::greatergreater:
367    case tok::ellipsis:
368      return true;
369
370    case tok::identifier:
371      // This may be either a type-parameter or an elaborated-type-specifier.
372      // We have to look further.
373      break;
374
375    default:
376      return false;
377    }
378
379    switch (GetLookAheadToken(2).getKind()) {
380    case tok::equal:
381    case tok::comma:
382    case tok::greater:
383    case tok::greatergreater:
384      return true;
385
386    default:
387      return false;
388    }
389  }
390
391  if (Tok.isNot(tok::kw_typename))
392    return false;
393
394  // C++ [temp.param]p2:
395  //   There is no semantic difference between class and typename in a
396  //   template-parameter. typename followed by an unqualified-id
397  //   names a template type parameter. typename followed by a
398  //   qualified-id denotes the type in a non-type
399  //   parameter-declaration.
400  Token Next = NextToken();
401
402  // If we have an identifier, skip over it.
403  if (Next.getKind() == tok::identifier)
404    Next = GetLookAheadToken(2);
405
406  switch (Next.getKind()) {
407  case tok::equal:
408  case tok::comma:
409  case tok::greater:
410  case tok::greatergreater:
411  case tok::ellipsis:
412    return true;
413
414  default:
415    return false;
416  }
417}
418
419/// ParseTemplateParameter - Parse a template-parameter (C++ [temp.param]).
420///
421///       template-parameter: [C++ temp.param]
422///         type-parameter
423///         parameter-declaration
424///
425///       type-parameter: (see below)
426///         'class' ...[opt] identifier[opt]
427///         'class' identifier[opt] '=' type-id
428///         'typename' ...[opt] identifier[opt]
429///         'typename' identifier[opt] '=' type-id
430///         'template' '<' template-parameter-list '>'
431///               'class' ...[opt] identifier[opt]
432///         'template' '<' template-parameter-list '>' 'class' identifier[opt]
433///               = id-expression
434Decl *Parser::ParseTemplateParameter(unsigned Depth, unsigned Position) {
435  if (isStartOfTemplateTypeParameter())
436    return ParseTypeParameter(Depth, Position);
437
438  if (Tok.is(tok::kw_template))
439    return ParseTemplateTemplateParameter(Depth, Position);
440
441  // If it's none of the above, then it must be a parameter declaration.
442  // NOTE: This will pick up errors in the closure of the template parameter
443  // list (e.g., template < ; Check here to implement >> style closures.
444  return ParseNonTypeTemplateParameter(Depth, Position);
445}
446
447/// ParseTypeParameter - Parse a template type parameter (C++ [temp.param]).
448/// Other kinds of template parameters are parsed in
449/// ParseTemplateTemplateParameter and ParseNonTypeTemplateParameter.
450///
451///       type-parameter:     [C++ temp.param]
452///         'class' ...[opt][C++0x] identifier[opt]
453///         'class' identifier[opt] '=' type-id
454///         'typename' ...[opt][C++0x] identifier[opt]
455///         'typename' identifier[opt] '=' type-id
456Decl *Parser::ParseTypeParameter(unsigned Depth, unsigned Position) {
457  assert((Tok.is(tok::kw_class) || Tok.is(tok::kw_typename)) &&
458         "A type-parameter starts with 'class' or 'typename'");
459
460  // Consume the 'class' or 'typename' keyword.
461  bool TypenameKeyword = Tok.is(tok::kw_typename);
462  SourceLocation KeyLoc = ConsumeToken();
463
464  // Grab the ellipsis (if given).
465  bool Ellipsis = false;
466  SourceLocation EllipsisLoc;
467  if (Tok.is(tok::ellipsis)) {
468    Ellipsis = true;
469    EllipsisLoc = ConsumeToken();
470
471    if (!getLang().CPlusPlus0x)
472      Diag(EllipsisLoc, diag::ext_variadic_templates);
473  }
474
475  // Grab the template parameter name (if given)
476  SourceLocation NameLoc;
477  IdentifierInfo* ParamName = 0;
478  if (Tok.is(tok::identifier)) {
479    ParamName = Tok.getIdentifierInfo();
480    NameLoc = ConsumeToken();
481  } else if (Tok.is(tok::equal) || Tok.is(tok::comma) ||
482            Tok.is(tok::greater)) {
483    // Unnamed template parameter. Don't have to do anything here, just
484    // don't consume this token.
485  } else {
486    Diag(Tok.getLocation(), diag::err_expected_ident);
487    return 0;
488  }
489
490  // Grab a default argument (if available).
491  // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
492  // we introduce the type parameter into the local scope.
493  SourceLocation EqualLoc;
494  ParsedType DefaultArg;
495  if (Tok.is(tok::equal)) {
496    EqualLoc = ConsumeToken();
497    DefaultArg = ParseTypeName().get();
498  }
499
500  return Actions.ActOnTypeParameter(getCurScope(), TypenameKeyword, Ellipsis,
501                                    EllipsisLoc, KeyLoc, ParamName, NameLoc,
502                                    Depth, Position, EqualLoc, DefaultArg);
503}
504
505/// ParseTemplateTemplateParameter - Handle the parsing of template
506/// template parameters.
507///
508///       type-parameter:    [C++ temp.param]
509///         'template' '<' template-parameter-list '>' 'class'
510///                  ...[opt] identifier[opt]
511///         'template' '<' template-parameter-list '>' 'class' identifier[opt]
512///                  = id-expression
513Decl *
514Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
515  assert(Tok.is(tok::kw_template) && "Expected 'template' keyword");
516
517  // Handle the template <...> part.
518  SourceLocation TemplateLoc = ConsumeToken();
519  llvm::SmallVector<Decl*,8> TemplateParams;
520  SourceLocation LAngleLoc, RAngleLoc;
521  {
522    ParseScope TemplateParmScope(this, Scope::TemplateParamScope);
523    if (ParseTemplateParameters(Depth + 1, TemplateParams, LAngleLoc,
524                               RAngleLoc)) {
525      return 0;
526    }
527  }
528
529  // Generate a meaningful error if the user forgot to put class before the
530  // identifier, comma, or greater.
531  if (!Tok.is(tok::kw_class)) {
532    Diag(Tok.getLocation(), diag::err_expected_class_before)
533      << PP.getSpelling(Tok);
534    return 0;
535  }
536  ConsumeToken();
537
538  // Parse the ellipsis, if given.
539  SourceLocation EllipsisLoc;
540  if (Tok.is(tok::ellipsis)) {
541    EllipsisLoc = ConsumeToken();
542
543    if (!getLang().CPlusPlus0x)
544      Diag(EllipsisLoc, diag::ext_variadic_templates);
545  }
546
547  // Get the identifier, if given.
548  SourceLocation NameLoc;
549  IdentifierInfo* ParamName = 0;
550  if (Tok.is(tok::identifier)) {
551    ParamName = Tok.getIdentifierInfo();
552    NameLoc = ConsumeToken();
553  } else if (Tok.is(tok::equal) || Tok.is(tok::comma) || Tok.is(tok::greater)) {
554    // Unnamed template parameter. Don't have to do anything here, just
555    // don't consume this token.
556  } else {
557    Diag(Tok.getLocation(), diag::err_expected_ident);
558    return 0;
559  }
560
561  TemplateParamsTy *ParamList =
562    Actions.ActOnTemplateParameterList(Depth, SourceLocation(),
563                                       TemplateLoc, LAngleLoc,
564                                       TemplateParams.data(),
565                                       TemplateParams.size(),
566                                       RAngleLoc);
567
568  // Grab a default argument (if available).
569  // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
570  // we introduce the template parameter into the local scope.
571  SourceLocation EqualLoc;
572  ParsedTemplateArgument DefaultArg;
573  if (Tok.is(tok::equal)) {
574    EqualLoc = ConsumeToken();
575    DefaultArg = ParseTemplateTemplateArgument();
576    if (DefaultArg.isInvalid()) {
577      Diag(Tok.getLocation(),
578           diag::err_default_template_template_parameter_not_template);
579      static const tok::TokenKind EndToks[] = {
580        tok::comma, tok::greater, tok::greatergreater
581      };
582      SkipUntil(EndToks, 3, true, true);
583    }
584  }
585
586  return Actions.ActOnTemplateTemplateParameter(getCurScope(), TemplateLoc,
587                                                ParamList, EllipsisLoc,
588                                                ParamName, NameLoc, Depth,
589                                                Position, EqualLoc, DefaultArg);
590}
591
592/// ParseNonTypeTemplateParameter - Handle the parsing of non-type
593/// template parameters (e.g., in "template<int Size> class array;").
594///
595///       template-parameter:
596///         ...
597///         parameter-declaration
598Decl *
599Parser::ParseNonTypeTemplateParameter(unsigned Depth, unsigned Position) {
600  // Parse the declaration-specifiers (i.e., the type).
601  // FIXME: The type should probably be restricted in some way... Not all
602  // declarators (parts of declarators?) are accepted for parameters.
603  DeclSpec DS(AttrFactory);
604  ParseDeclarationSpecifiers(DS);
605
606  // Parse this as a typename.
607  Declarator ParamDecl(DS, Declarator::TemplateParamContext);
608  ParseDeclarator(ParamDecl);
609  if (DS.getTypeSpecType() == DeclSpec::TST_unspecified) {
610    // This probably shouldn't happen - and it's more of a Sema thing, but
611    // basically we didn't parse the type name because we couldn't associate
612    // it with an AST node. we should just skip to the comma or greater.
613    // TODO: This is currently a placeholder for some kind of Sema Error.
614    Diag(Tok.getLocation(), diag::err_parse_error);
615    SkipUntil(tok::comma, tok::greater, true, true);
616    return 0;
617  }
618
619  // If there is a default value, parse it.
620  // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before
621  // we introduce the template parameter into the local scope.
622  SourceLocation EqualLoc;
623  ExprResult DefaultArg;
624  if (Tok.is(tok::equal)) {
625    EqualLoc = ConsumeToken();
626
627    // C++ [temp.param]p15:
628    //   When parsing a default template-argument for a non-type
629    //   template-parameter, the first non-nested > is taken as the
630    //   end of the template-parameter-list rather than a greater-than
631    //   operator.
632    GreaterThanIsOperatorScope G(GreaterThanIsOperator, false);
633
634    DefaultArg = ParseAssignmentExpression();
635    if (DefaultArg.isInvalid())
636      SkipUntil(tok::comma, tok::greater, true, true);
637  }
638
639  // Create the parameter.
640  return Actions.ActOnNonTypeTemplateParameter(getCurScope(), ParamDecl,
641                                               Depth, Position, EqualLoc,
642                                               DefaultArg.take());
643}
644
645/// \brief Parses a template-id that after the template name has
646/// already been parsed.
647///
648/// This routine takes care of parsing the enclosed template argument
649/// list ('<' template-parameter-list [opt] '>') and placing the
650/// results into a form that can be transferred to semantic analysis.
651///
652/// \param Template the template declaration produced by isTemplateName
653///
654/// \param TemplateNameLoc the source location of the template name
655///
656/// \param SS if non-NULL, the nested-name-specifier preceding the
657/// template name.
658///
659/// \param ConsumeLastToken if true, then we will consume the last
660/// token that forms the template-id. Otherwise, we will leave the
661/// last token in the stream (e.g., so that it can be replaced with an
662/// annotation token).
663bool
664Parser::ParseTemplateIdAfterTemplateName(TemplateTy Template,
665                                         SourceLocation TemplateNameLoc,
666                                         const CXXScopeSpec &SS,
667                                         bool ConsumeLastToken,
668                                         SourceLocation &LAngleLoc,
669                                         TemplateArgList &TemplateArgs,
670                                         SourceLocation &RAngleLoc) {
671  assert(Tok.is(tok::less) && "Must have already parsed the template-name");
672
673  // Consume the '<'.
674  LAngleLoc = ConsumeToken();
675
676  // Parse the optional template-argument-list.
677  bool Invalid = false;
678  {
679    GreaterThanIsOperatorScope G(GreaterThanIsOperator, false);
680    if (Tok.isNot(tok::greater) && Tok.isNot(tok::greatergreater))
681      Invalid = ParseTemplateArgumentList(TemplateArgs);
682
683    if (Invalid) {
684      // Try to find the closing '>'.
685      SkipUntil(tok::greater, true, !ConsumeLastToken);
686
687      return true;
688    }
689  }
690
691  if (Tok.isNot(tok::greater) && Tok.isNot(tok::greatergreater)) {
692    Diag(Tok.getLocation(), diag::err_expected_greater);
693    return true;
694  }
695
696  // Determine the location of the '>' or '>>'. Only consume this
697  // token if the caller asked us to.
698  RAngleLoc = Tok.getLocation();
699
700  if (Tok.is(tok::greatergreater)) {
701    if (!getLang().CPlusPlus0x) {
702      const char *ReplaceStr = "> >";
703      if (NextToken().is(tok::greater) || NextToken().is(tok::greatergreater))
704        ReplaceStr = "> > ";
705
706      Diag(Tok.getLocation(), diag::err_two_right_angle_brackets_need_space)
707        << FixItHint::CreateReplacement(
708                                 SourceRange(Tok.getLocation()), ReplaceStr);
709    }
710
711    Tok.setKind(tok::greater);
712    if (!ConsumeLastToken) {
713      // Since we're not supposed to consume the '>>' token, we need
714      // to insert a second '>' token after the first.
715      PP.EnterToken(Tok);
716    }
717  } else if (ConsumeLastToken)
718    ConsumeToken();
719
720  return false;
721}
722
723/// \brief Replace the tokens that form a simple-template-id with an
724/// annotation token containing the complete template-id.
725///
726/// The first token in the stream must be the name of a template that
727/// is followed by a '<'. This routine will parse the complete
728/// simple-template-id and replace the tokens with a single annotation
729/// token with one of two different kinds: if the template-id names a
730/// type (and \p AllowTypeAnnotation is true), the annotation token is
731/// a type annotation that includes the optional nested-name-specifier
732/// (\p SS). Otherwise, the annotation token is a template-id
733/// annotation that does not include the optional
734/// nested-name-specifier.
735///
736/// \param Template  the declaration of the template named by the first
737/// token (an identifier), as returned from \c Action::isTemplateName().
738///
739/// \param TemplateNameKind the kind of template that \p Template
740/// refers to, as returned from \c Action::isTemplateName().
741///
742/// \param SS if non-NULL, the nested-name-specifier that precedes
743/// this template name.
744///
745/// \param TemplateKWLoc if valid, specifies that this template-id
746/// annotation was preceded by the 'template' keyword and gives the
747/// location of that keyword. If invalid (the default), then this
748/// template-id was not preceded by a 'template' keyword.
749///
750/// \param AllowTypeAnnotation if true (the default), then a
751/// simple-template-id that refers to a class template, template
752/// template parameter, or other template that produces a type will be
753/// replaced with a type annotation token. Otherwise, the
754/// simple-template-id is always replaced with a template-id
755/// annotation token.
756///
757/// If an unrecoverable parse error occurs and no annotation token can be
758/// formed, this function returns true.
759///
760bool Parser::AnnotateTemplateIdToken(TemplateTy Template, TemplateNameKind TNK,
761                                     CXXScopeSpec &SS,
762                                     UnqualifiedId &TemplateName,
763                                     SourceLocation TemplateKWLoc,
764                                     bool AllowTypeAnnotation) {
765  assert(getLang().CPlusPlus && "Can only annotate template-ids in C++");
766  assert(Template && Tok.is(tok::less) &&
767         "Parser isn't at the beginning of a template-id");
768
769  // Consume the template-name.
770  SourceLocation TemplateNameLoc = TemplateName.getSourceRange().getBegin();
771
772  // Parse the enclosed template argument list.
773  SourceLocation LAngleLoc, RAngleLoc;
774  TemplateArgList TemplateArgs;
775  bool Invalid = ParseTemplateIdAfterTemplateName(Template,
776                                                  TemplateNameLoc,
777                                                  SS, false, LAngleLoc,
778                                                  TemplateArgs,
779                                                  RAngleLoc);
780
781  if (Invalid) {
782    // If we failed to parse the template ID but skipped ahead to a >, we're not
783    // going to be able to form a token annotation.  Eat the '>' if present.
784    if (Tok.is(tok::greater))
785      ConsumeToken();
786    return true;
787  }
788
789  ASTTemplateArgsPtr TemplateArgsPtr(Actions, TemplateArgs.data(),
790                                     TemplateArgs.size());
791
792  // Build the annotation token.
793  if (TNK == TNK_Type_template && AllowTypeAnnotation) {
794    TypeResult Type
795      = Actions.ActOnTemplateIdType(SS,
796                                    Template, TemplateNameLoc,
797                                    LAngleLoc, TemplateArgsPtr,
798                                    RAngleLoc);
799    if (Type.isInvalid()) {
800      // If we failed to parse the template ID but skipped ahead to a >, we're not
801      // going to be able to form a token annotation.  Eat the '>' if present.
802      if (Tok.is(tok::greater))
803        ConsumeToken();
804      return true;
805    }
806
807    Tok.setKind(tok::annot_typename);
808    setTypeAnnotation(Tok, Type.get());
809    if (SS.isNotEmpty())
810      Tok.setLocation(SS.getBeginLoc());
811    else if (TemplateKWLoc.isValid())
812      Tok.setLocation(TemplateKWLoc);
813    else
814      Tok.setLocation(TemplateNameLoc);
815  } else {
816    // Build a template-id annotation token that can be processed
817    // later.
818    Tok.setKind(tok::annot_template_id);
819    TemplateIdAnnotation *TemplateId
820      = TemplateIdAnnotation::Allocate(TemplateArgs.size());
821    TemplateId->TemplateNameLoc = TemplateNameLoc;
822    if (TemplateName.getKind() == UnqualifiedId::IK_Identifier) {
823      TemplateId->Name = TemplateName.Identifier;
824      TemplateId->Operator = OO_None;
825    } else {
826      TemplateId->Name = 0;
827      TemplateId->Operator = TemplateName.OperatorFunctionId.Operator;
828    }
829    TemplateId->SS = SS;
830    TemplateId->Template = Template;
831    TemplateId->Kind = TNK;
832    TemplateId->LAngleLoc = LAngleLoc;
833    TemplateId->RAngleLoc = RAngleLoc;
834    ParsedTemplateArgument *Args = TemplateId->getTemplateArgs();
835    for (unsigned Arg = 0, ArgEnd = TemplateArgs.size(); Arg != ArgEnd; ++Arg)
836      Args[Arg] = ParsedTemplateArgument(TemplateArgs[Arg]);
837    Tok.setAnnotationValue(TemplateId);
838    if (TemplateKWLoc.isValid())
839      Tok.setLocation(TemplateKWLoc);
840    else
841      Tok.setLocation(TemplateNameLoc);
842
843    TemplateArgsPtr.release();
844  }
845
846  // Common fields for the annotation token
847  Tok.setAnnotationEndLoc(RAngleLoc);
848
849  // In case the tokens were cached, have Preprocessor replace them with the
850  // annotation token.
851  PP.AnnotateCachedTokens(Tok);
852  return false;
853}
854
855/// \brief Replaces a template-id annotation token with a type
856/// annotation token.
857///
858/// If there was a failure when forming the type from the template-id,
859/// a type annotation token will still be created, but will have a
860/// NULL type pointer to signify an error.
861void Parser::AnnotateTemplateIdTokenAsType() {
862  assert(Tok.is(tok::annot_template_id) && "Requires template-id tokens");
863
864  TemplateIdAnnotation *TemplateId
865    = static_cast<TemplateIdAnnotation *>(Tok.getAnnotationValue());
866  assert((TemplateId->Kind == TNK_Type_template ||
867          TemplateId->Kind == TNK_Dependent_template_name) &&
868         "Only works for type and dependent templates");
869
870  ASTTemplateArgsPtr TemplateArgsPtr(Actions,
871                                     TemplateId->getTemplateArgs(),
872                                     TemplateId->NumArgs);
873
874  TypeResult Type
875    = Actions.ActOnTemplateIdType(TemplateId->SS,
876                                  TemplateId->Template,
877                                  TemplateId->TemplateNameLoc,
878                                  TemplateId->LAngleLoc,
879                                  TemplateArgsPtr,
880                                  TemplateId->RAngleLoc);
881  // Create the new "type" annotation token.
882  Tok.setKind(tok::annot_typename);
883  setTypeAnnotation(Tok, Type.isInvalid() ? ParsedType() : Type.get());
884  if (TemplateId->SS.isNotEmpty()) // it was a C++ qualified type name.
885    Tok.setLocation(TemplateId->SS.getBeginLoc());
886  // End location stays the same
887
888  // Replace the template-id annotation token, and possible the scope-specifier
889  // that precedes it, with the typename annotation token.
890  PP.AnnotateCachedTokens(Tok);
891  TemplateId->Destroy();
892}
893
894/// \brief Determine whether the given token can end a template argument.
895static bool isEndOfTemplateArgument(Token Tok) {
896  return Tok.is(tok::comma) || Tok.is(tok::greater) ||
897         Tok.is(tok::greatergreater);
898}
899
900/// \brief Parse a C++ template template argument.
901ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() {
902  if (!Tok.is(tok::identifier) && !Tok.is(tok::coloncolon) &&
903      !Tok.is(tok::annot_cxxscope))
904    return ParsedTemplateArgument();
905
906  // C++0x [temp.arg.template]p1:
907  //   A template-argument for a template template-parameter shall be the name
908  //   of a class template or a template alias, expressed as id-expression.
909  //
910  // We parse an id-expression that refers to a class template or template
911  // alias. The grammar we parse is:
912  //
913  //   nested-name-specifier[opt] template[opt] identifier ...[opt]
914  //
915  // followed by a token that terminates a template argument, such as ',',
916  // '>', or (in some cases) '>>'.
917  CXXScopeSpec SS; // nested-name-specifier, if present
918  ParseOptionalCXXScopeSpecifier(SS, ParsedType(),
919                                 /*EnteringContext=*/false);
920
921  ParsedTemplateArgument Result;
922  SourceLocation EllipsisLoc;
923  if (SS.isSet() && Tok.is(tok::kw_template)) {
924    // Parse the optional 'template' keyword following the
925    // nested-name-specifier.
926    SourceLocation TemplateLoc = ConsumeToken();
927
928    if (Tok.is(tok::identifier)) {
929      // We appear to have a dependent template name.
930      UnqualifiedId Name;
931      Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
932      ConsumeToken(); // the identifier
933
934      // Parse the ellipsis.
935      if (Tok.is(tok::ellipsis))
936        EllipsisLoc = ConsumeToken();
937
938      // If the next token signals the end of a template argument,
939      // then we have a dependent template name that could be a template
940      // template argument.
941      TemplateTy Template;
942      if (isEndOfTemplateArgument(Tok) &&
943          Actions.ActOnDependentTemplateName(getCurScope(), TemplateLoc,
944                                             SS, Name,
945                                             /*ObjectType=*/ ParsedType(),
946                                             /*EnteringContext=*/false,
947                                             Template))
948        Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
949    }
950  } else if (Tok.is(tok::identifier)) {
951    // We may have a (non-dependent) template name.
952    TemplateTy Template;
953    UnqualifiedId Name;
954    Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
955    ConsumeToken(); // the identifier
956
957    // Parse the ellipsis.
958    if (Tok.is(tok::ellipsis))
959      EllipsisLoc = ConsumeToken();
960
961    if (isEndOfTemplateArgument(Tok)) {
962      bool MemberOfUnknownSpecialization;
963      TemplateNameKind TNK = Actions.isTemplateName(getCurScope(), SS,
964                                               /*hasTemplateKeyword=*/false,
965                                                    Name,
966                                               /*ObjectType=*/ ParsedType(),
967                                                    /*EnteringContext=*/false,
968                                                    Template,
969                                                MemberOfUnknownSpecialization);
970      if (TNK == TNK_Dependent_template_name || TNK == TNK_Type_template) {
971        // We have an id-expression that refers to a class template or
972        // (C++0x) template alias.
973        Result = ParsedTemplateArgument(SS, Template, Name.StartLocation);
974      }
975    }
976  }
977
978  // If this is a pack expansion, build it as such.
979  if (EllipsisLoc.isValid() && !Result.isInvalid())
980    Result = Actions.ActOnPackExpansion(Result, EllipsisLoc);
981
982  return Result;
983}
984
985/// ParseTemplateArgument - Parse a C++ template argument (C++ [temp.names]).
986///
987///       template-argument: [C++ 14.2]
988///         constant-expression
989///         type-id
990///         id-expression
991ParsedTemplateArgument Parser::ParseTemplateArgument() {
992  // C++ [temp.arg]p2:
993  //   In a template-argument, an ambiguity between a type-id and an
994  //   expression is resolved to a type-id, regardless of the form of
995  //   the corresponding template-parameter.
996  //
997  // Therefore, we initially try to parse a type-id.
998  if (isCXXTypeId(TypeIdAsTemplateArgument)) {
999    SourceLocation Loc = Tok.getLocation();
1000    TypeResult TypeArg = ParseTypeName(/*Range=*/0,
1001                                       Declarator::TemplateTypeArgContext);
1002    if (TypeArg.isInvalid())
1003      return ParsedTemplateArgument();
1004
1005    return ParsedTemplateArgument(ParsedTemplateArgument::Type,
1006                                  TypeArg.get().getAsOpaquePtr(),
1007                                  Loc);
1008  }
1009
1010  // Try to parse a template template argument.
1011  {
1012    TentativeParsingAction TPA(*this);
1013
1014    ParsedTemplateArgument TemplateTemplateArgument
1015      = ParseTemplateTemplateArgument();
1016    if (!TemplateTemplateArgument.isInvalid()) {
1017      TPA.Commit();
1018      return TemplateTemplateArgument;
1019    }
1020
1021    // Revert this tentative parse to parse a non-type template argument.
1022    TPA.Revert();
1023  }
1024
1025  // Parse a non-type template argument.
1026  SourceLocation Loc = Tok.getLocation();
1027  ExprResult ExprArg = ParseConstantExpression();
1028  if (ExprArg.isInvalid() || !ExprArg.get())
1029    return ParsedTemplateArgument();
1030
1031  return ParsedTemplateArgument(ParsedTemplateArgument::NonType,
1032                                ExprArg.release(), Loc);
1033}
1034
1035/// \brief Determine whether the current tokens can only be parsed as a
1036/// template argument list (starting with the '<') and never as a '<'
1037/// expression.
1038bool Parser::IsTemplateArgumentList(unsigned Skip) {
1039  struct AlwaysRevertAction : TentativeParsingAction {
1040    AlwaysRevertAction(Parser &P) : TentativeParsingAction(P) { }
1041    ~AlwaysRevertAction() { Revert(); }
1042  } Tentative(*this);
1043
1044  while (Skip) {
1045    ConsumeToken();
1046    --Skip;
1047  }
1048
1049  // '<'
1050  if (!Tok.is(tok::less))
1051    return false;
1052  ConsumeToken();
1053
1054  // An empty template argument list.
1055  if (Tok.is(tok::greater))
1056    return true;
1057
1058  // See whether we have declaration specifiers, which indicate a type.
1059  while (isCXXDeclarationSpecifier() == TPResult::True())
1060    ConsumeToken();
1061
1062  // If we have a '>' or a ',' then this is a template argument list.
1063  return Tok.is(tok::greater) || Tok.is(tok::comma);
1064}
1065
1066/// ParseTemplateArgumentList - Parse a C++ template-argument-list
1067/// (C++ [temp.names]). Returns true if there was an error.
1068///
1069///       template-argument-list: [C++ 14.2]
1070///         template-argument
1071///         template-argument-list ',' template-argument
1072bool
1073Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs) {
1074  while (true) {
1075    ParsedTemplateArgument Arg = ParseTemplateArgument();
1076    if (Tok.is(tok::ellipsis)) {
1077      SourceLocation EllipsisLoc  = ConsumeToken();
1078      Arg = Actions.ActOnPackExpansion(Arg, EllipsisLoc);
1079    }
1080
1081    if (Arg.isInvalid()) {
1082      SkipUntil(tok::comma, tok::greater, true, true);
1083      return true;
1084    }
1085
1086    // Save this template argument.
1087    TemplateArgs.push_back(Arg);
1088
1089    // If the next token is a comma, consume it and keep reading
1090    // arguments.
1091    if (Tok.isNot(tok::comma)) break;
1092
1093    // Consume the comma.
1094    ConsumeToken();
1095  }
1096
1097  return false;
1098}
1099
1100/// \brief Parse a C++ explicit template instantiation
1101/// (C++ [temp.explicit]).
1102///
1103///       explicit-instantiation:
1104///         'extern' [opt] 'template' declaration
1105///
1106/// Note that the 'extern' is a GNU extension and C++0x feature.
1107Decl *Parser::ParseExplicitInstantiation(SourceLocation ExternLoc,
1108                                         SourceLocation TemplateLoc,
1109                                         SourceLocation &DeclEnd) {
1110  // This isn't really required here.
1111  ParsingDeclRAIIObject ParsingTemplateParams(*this);
1112
1113  return ParseSingleDeclarationAfterTemplate(Declarator::FileContext,
1114                                             ParsedTemplateInfo(ExternLoc,
1115                                                                TemplateLoc),
1116                                             ParsingTemplateParams,
1117                                             DeclEnd, AS_none);
1118}
1119
1120SourceRange Parser::ParsedTemplateInfo::getSourceRange() const {
1121  if (TemplateParams)
1122    return getTemplateParamsRange(TemplateParams->data(),
1123                                  TemplateParams->size());
1124
1125  SourceRange R(TemplateLoc);
1126  if (ExternLoc.isValid())
1127    R.setBegin(ExternLoc);
1128  return R;
1129}
1130
1131void Parser::LateTemplateParserCallback(void *P, const FunctionDecl *FD) {
1132  ((Parser*)P)->LateTemplateParser(FD);
1133}
1134
1135
1136void Parser::LateTemplateParser(const FunctionDecl *FD) {
1137  LateParsedTemplatedFunction *LPT = LateParsedTemplateMap[FD];
1138  if (LPT) {
1139    ParseLateTemplatedFuncDef(*LPT);
1140    return;
1141  }
1142
1143  llvm_unreachable("Late templated function without associated lexed tokens");
1144}
1145
1146/// \brief Late parse a C++ function template in Microsoft mode.
1147void Parser::ParseLateTemplatedFuncDef(LateParsedTemplatedFunction &LMT) {
1148  if(!LMT.D)
1149     return;
1150
1151  // If this is a member template, introduce the template parameter scope.
1152  ParseScope TemplateScope(this, Scope::TemplateParamScope);
1153
1154  // Get the FunctionDecl.
1155  FunctionDecl *FD = 0;
1156  if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(LMT.D))
1157    FD = FunTmpl->getTemplatedDecl();
1158  else
1159    FD = cast<FunctionDecl>(LMT.D);
1160
1161  // Reinject the template parameters.
1162  DeclaratorDecl* Declarator = dyn_cast<DeclaratorDecl>(FD);
1163  if (Declarator && Declarator->getNumTemplateParameterLists() != 0) {
1164    Actions.ActOnReenterDeclaratorTemplateScope(getCurScope(), Declarator);
1165    Actions.ActOnReenterTemplateScope(getCurScope(), LMT.D);
1166  } else {
1167    Actions.ActOnReenterTemplateScope(getCurScope(), LMT.D);
1168
1169    DeclContext *DD = FD->getLexicalParent();
1170    while (DD && DD->isRecord()) {
1171      if (ClassTemplatePartialSpecializationDecl* MD =
1172                  dyn_cast_or_null<ClassTemplatePartialSpecializationDecl>(DD))
1173          Actions.ActOnReenterTemplateScope(getCurScope(), MD);
1174      else if (CXXRecordDecl* MD = dyn_cast_or_null<CXXRecordDecl>(DD))
1175          Actions.ActOnReenterTemplateScope(getCurScope(),
1176                                            MD->getDescribedClassTemplate());
1177
1178      DD = DD->getLexicalParent();
1179    }
1180  }
1181  assert(!LMT.Toks.empty() && "Empty body!");
1182
1183  // Append the current token at the end of the new token stream so that it
1184  // doesn't get lost.
1185  LMT.Toks.push_back(Tok);
1186  PP.EnterTokenStream(LMT.Toks.data(), LMT.Toks.size(), true, false);
1187
1188  // Consume the previously pushed token.
1189  ConsumeAnyToken();
1190  assert((Tok.is(tok::l_brace) || Tok.is(tok::colon) || Tok.is(tok::kw_try))
1191         && "Inline method not starting with '{', ':' or 'try'");
1192
1193  // Parse the method body. Function body parsing code is similar enough
1194  // to be re-used for method bodies as well.
1195  ParseScope FnScope(this, Scope::FnScope|Scope::DeclScope);
1196
1197  // Recreate the DeclContext.
1198  Sema::ContextRAII SavedContext(Actions, Actions.getContainingDC(FD));
1199
1200  if (FunctionTemplateDecl *FunctionTemplate
1201        = dyn_cast_or_null<FunctionTemplateDecl>(LMT.D))
1202    Actions.ActOnStartOfFunctionDef(getCurScope(),
1203                                   FunctionTemplate->getTemplatedDecl());
1204  if (FunctionDecl *Function = dyn_cast_or_null<FunctionDecl>(LMT.D))
1205    Actions.ActOnStartOfFunctionDef(getCurScope(), Function);
1206
1207
1208  if (Tok.is(tok::kw_try)) {
1209    ParseFunctionTryBlock(LMT.D, FnScope);
1210    return;
1211  }
1212  if (Tok.is(tok::colon)) {
1213    ParseConstructorInitializer(LMT.D);
1214
1215    // Error recovery.
1216    if (!Tok.is(tok::l_brace)) {
1217      Actions.ActOnFinishFunctionBody(LMT.D, 0);
1218      return;
1219    }
1220  } else
1221    Actions.ActOnDefaultCtorInitializers(LMT.D);
1222
1223  ParseFunctionStatementBody(LMT.D, FnScope);
1224  Actions.MarkAsLateParsedTemplate(FD, false);
1225
1226  DeclGroupPtrTy grp = Actions.ConvertDeclToDeclGroup(LMT.D);
1227  if (grp)
1228    Actions.getASTConsumer().HandleTopLevelDecl(grp.get());
1229}
1230
1231/// \brief Lex a delayed template function for late parsing.
1232void Parser::LexTemplateFunctionForLateParsing(CachedTokens &Toks) {
1233  tok::TokenKind kind = Tok.getKind();
1234  // We may have a constructor initializer or function-try-block here.
1235  if (kind == tok::colon || kind == tok::kw_try)
1236    ConsumeAndStoreUntil(tok::l_brace, Toks);
1237  else {
1238    Toks.push_back(Tok);
1239    ConsumeBrace();
1240  }
1241  // Consume everything up to (and including) the matching right brace.
1242  ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
1243
1244  // If we're in a function-try-block, we need to store all the catch blocks.
1245  if (kind == tok::kw_try) {
1246    while (Tok.is(tok::kw_catch)) {
1247      ConsumeAndStoreUntil(tok::l_brace, Toks, /*StopAtSemi=*/false);
1248      ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
1249    }
1250  }
1251}
1252