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      1 //===--- ParseCXXInlineMethods.cpp - C++ class inline methods 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 for C++ class inline methods.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "clang/Parse/ParseDiagnostic.h"
     15 #include "clang/Parse/Parser.h"
     16 #include "clang/Sema/DeclSpec.h"
     17 #include "clang/Sema/Scope.h"
     18 #include "clang/AST/DeclTemplate.h"
     19 using namespace clang;
     20 
     21 /// ParseCXXInlineMethodDef - We parsed and verified that the specified
     22 /// Declarator is a well formed C++ inline method definition. Now lex its body
     23 /// and store its tokens for parsing after the C++ class is complete.
     24 Decl *Parser::ParseCXXInlineMethodDef(AccessSpecifier AS, ParsingDeclarator &D,
     25                                 const ParsedTemplateInfo &TemplateInfo,
     26                                 const VirtSpecifiers& VS, ExprResult& Init) {
     27   assert(D.isFunctionDeclarator() && "This isn't a function declarator!");
     28   assert((Tok.is(tok::l_brace) || Tok.is(tok::colon) || Tok.is(tok::kw_try) ||
     29           Tok.is(tok::equal)) &&
     30          "Current token not a '{', ':', '=', or 'try'!");
     31 
     32   MultiTemplateParamsArg TemplateParams(Actions,
     33           TemplateInfo.TemplateParams ? TemplateInfo.TemplateParams->data() : 0,
     34           TemplateInfo.TemplateParams ? TemplateInfo.TemplateParams->size() : 0);
     35 
     36   Decl *FnD;
     37   if (D.getDeclSpec().isFriendSpecified())
     38     // FIXME: Friend templates
     39     FnD = Actions.ActOnFriendFunctionDecl(getCurScope(), D, true,
     40                                           move(TemplateParams));
     41   else { // FIXME: pass template information through
     42     FnD = Actions.ActOnCXXMemberDeclarator(getCurScope(), AS, D,
     43                                            move(TemplateParams), 0,
     44                                            VS, Init.release(),
     45                                            /*HasInit=*/false,
     46                                            /*IsDefinition*/true);
     47   }
     48 
     49   HandleMemberFunctionDefaultArgs(D, FnD);
     50 
     51   D.complete(FnD);
     52 
     53   if (Tok.is(tok::equal)) {
     54     ConsumeToken();
     55 
     56     bool Delete = false;
     57     SourceLocation KWLoc;
     58     if (Tok.is(tok::kw_delete)) {
     59       if (!getLang().CPlusPlus0x)
     60         Diag(Tok, diag::warn_deleted_function_accepted_as_extension);
     61 
     62       KWLoc = ConsumeToken();
     63       Actions.SetDeclDeleted(FnD, KWLoc);
     64       Delete = true;
     65     } else if (Tok.is(tok::kw_default)) {
     66       if (!getLang().CPlusPlus0x)
     67         Diag(Tok, diag::warn_defaulted_function_accepted_as_extension);
     68 
     69       KWLoc = ConsumeToken();
     70       Actions.SetDeclDefaulted(FnD, KWLoc);
     71     } else {
     72       llvm_unreachable("function definition after = not 'delete' or 'default'");
     73     }
     74 
     75     if (Tok.is(tok::comma)) {
     76       Diag(KWLoc, diag::err_default_delete_in_multiple_declaration)
     77         << Delete;
     78       SkipUntil(tok::semi);
     79     } else {
     80       ExpectAndConsume(tok::semi, diag::err_expected_semi_after,
     81                        Delete ? "delete" : "default", tok::semi);
     82     }
     83 
     84     return FnD;
     85   }
     86 
     87   // In delayed template parsing mode, if we are within a class template
     88   // or if we are about to parse function member template then consume
     89   // the tokens and store them for parsing at the end of the translation unit.
     90   if (getLang().DelayedTemplateParsing &&
     91       ((Actions.CurContext->isDependentContext() ||
     92         TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate) &&
     93         !Actions.IsInsideALocalClassWithinATemplateFunction()) &&
     94         !D.getDeclSpec().isFriendSpecified()) {
     95 
     96     if (FnD) {
     97       LateParsedTemplatedFunction *LPT =
     98         new LateParsedTemplatedFunction(this, FnD);
     99 
    100       FunctionDecl *FD = 0;
    101       if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(FnD))
    102         FD = FunTmpl->getTemplatedDecl();
    103       else
    104         FD = cast<FunctionDecl>(FnD);
    105       Actions.CheckForFunctionRedefinition(FD);
    106 
    107       LateParsedTemplateMap[FD] = LPT;
    108       Actions.MarkAsLateParsedTemplate(FD);
    109       LexTemplateFunctionForLateParsing(LPT->Toks);
    110     } else {
    111       CachedTokens Toks;
    112       LexTemplateFunctionForLateParsing(Toks);
    113     }
    114 
    115     return FnD;
    116   }
    117 
    118   // Consume the tokens and store them for later parsing.
    119 
    120   LexedMethod* LM = new LexedMethod(this, FnD);
    121   getCurrentClass().LateParsedDeclarations.push_back(LM);
    122   LM->TemplateScope = getCurScope()->isTemplateParamScope();
    123   CachedTokens &Toks = LM->Toks;
    124 
    125   tok::TokenKind kind = Tok.getKind();
    126   // We may have a constructor initializer or function-try-block here.
    127   if (kind == tok::colon || kind == tok::kw_try) {
    128     // Consume everything up to (and including) the left brace.
    129     if (!ConsumeAndStoreUntil(tok::l_brace, Toks)) {
    130       // We didn't find the left-brace we expected after the
    131       // constructor initializer.
    132       if (Tok.is(tok::semi)) {
    133         // We found a semicolon; complain, consume the semicolon, and
    134         // don't try to parse this method later.
    135         Diag(Tok.getLocation(), diag::err_expected_lbrace);
    136         ConsumeAnyToken();
    137         delete getCurrentClass().LateParsedDeclarations.back();
    138         getCurrentClass().LateParsedDeclarations.pop_back();
    139         return FnD;
    140       }
    141     }
    142 
    143   } else {
    144     // Begin by storing the '{' token.
    145     Toks.push_back(Tok);
    146     ConsumeBrace();
    147   }
    148   // Consume everything up to (and including) the matching right brace.
    149   ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
    150 
    151   // If we're in a function-try-block, we need to store all the catch blocks.
    152   if (kind == tok::kw_try) {
    153     while (Tok.is(tok::kw_catch)) {
    154       ConsumeAndStoreUntil(tok::l_brace, Toks, /*StopAtSemi=*/false);
    155       ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
    156     }
    157   }
    158 
    159 
    160   if (!FnD) {
    161     // If semantic analysis could not build a function declaration,
    162     // just throw away the late-parsed declaration.
    163     delete getCurrentClass().LateParsedDeclarations.back();
    164     getCurrentClass().LateParsedDeclarations.pop_back();
    165   }
    166 
    167   return FnD;
    168 }
    169 
    170 /// ParseCXXNonStaticMemberInitializer - We parsed and verified that the
    171 /// specified Declarator is a well formed C++ non-static data member
    172 /// declaration. Now lex its initializer and store its tokens for parsing
    173 /// after the class is complete.
    174 void Parser::ParseCXXNonStaticMemberInitializer(Decl *VarD) {
    175   assert((Tok.is(tok::l_brace) || Tok.is(tok::equal)) &&
    176          "Current token not a '{' or '='!");
    177 
    178   LateParsedMemberInitializer *MI =
    179     new LateParsedMemberInitializer(this, VarD);
    180   getCurrentClass().LateParsedDeclarations.push_back(MI);
    181   CachedTokens &Toks = MI->Toks;
    182 
    183   tok::TokenKind kind = Tok.getKind();
    184   if (kind == tok::equal) {
    185     Toks.push_back(Tok);
    186     ConsumeAnyToken();
    187   }
    188 
    189   if (kind == tok::l_brace) {
    190     // Begin by storing the '{' token.
    191     Toks.push_back(Tok);
    192     ConsumeBrace();
    193 
    194     // Consume everything up to (and including) the matching right brace.
    195     ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/true);
    196   } else {
    197     // Consume everything up to (but excluding) the comma or semicolon.
    198     ConsumeAndStoreUntil(tok::comma, Toks, /*StopAtSemi=*/true,
    199                          /*ConsumeFinalToken=*/false);
    200   }
    201 
    202   // Store an artificial EOF token to ensure that we don't run off the end of
    203   // the initializer when we come to parse it.
    204   Token Eof;
    205   Eof.startToken();
    206   Eof.setKind(tok::eof);
    207   Eof.setLocation(Tok.getLocation());
    208   Toks.push_back(Eof);
    209 }
    210 
    211 Parser::LateParsedDeclaration::~LateParsedDeclaration() {}
    212 void Parser::LateParsedDeclaration::ParseLexedMethodDeclarations() {}
    213 void Parser::LateParsedDeclaration::ParseLexedMemberInitializers() {}
    214 void Parser::LateParsedDeclaration::ParseLexedMethodDefs() {}
    215 
    216 Parser::LateParsedClass::LateParsedClass(Parser *P, ParsingClass *C)
    217   : Self(P), Class(C) {}
    218 
    219 Parser::LateParsedClass::~LateParsedClass() {
    220   Self->DeallocateParsedClasses(Class);
    221 }
    222 
    223 void Parser::LateParsedClass::ParseLexedMethodDeclarations() {
    224   Self->ParseLexedMethodDeclarations(*Class);
    225 }
    226 
    227 void Parser::LateParsedClass::ParseLexedMemberInitializers() {
    228   Self->ParseLexedMemberInitializers(*Class);
    229 }
    230 
    231 void Parser::LateParsedClass::ParseLexedMethodDefs() {
    232   Self->ParseLexedMethodDefs(*Class);
    233 }
    234 
    235 void Parser::LateParsedMethodDeclaration::ParseLexedMethodDeclarations() {
    236   Self->ParseLexedMethodDeclaration(*this);
    237 }
    238 
    239 void Parser::LexedMethod::ParseLexedMethodDefs() {
    240   Self->ParseLexedMethodDef(*this);
    241 }
    242 
    243 void Parser::LateParsedMemberInitializer::ParseLexedMemberInitializers() {
    244   Self->ParseLexedMemberInitializer(*this);
    245 }
    246 
    247 /// ParseLexedMethodDeclarations - We finished parsing the member
    248 /// specification of a top (non-nested) C++ class. Now go over the
    249 /// stack of method declarations with some parts for which parsing was
    250 /// delayed (such as default arguments) and parse them.
    251 void Parser::ParseLexedMethodDeclarations(ParsingClass &Class) {
    252   bool HasTemplateScope = !Class.TopLevelClass && Class.TemplateScope;
    253   ParseScope ClassTemplateScope(this, Scope::TemplateParamScope, HasTemplateScope);
    254   if (HasTemplateScope)
    255     Actions.ActOnReenterTemplateScope(getCurScope(), Class.TagOrTemplate);
    256 
    257   // The current scope is still active if we're the top-level class.
    258   // Otherwise we'll need to push and enter a new scope.
    259   bool HasClassScope = !Class.TopLevelClass;
    260   ParseScope ClassScope(this, Scope::ClassScope|Scope::DeclScope,
    261                         HasClassScope);
    262   if (HasClassScope)
    263     Actions.ActOnStartDelayedMemberDeclarations(getCurScope(), Class.TagOrTemplate);
    264 
    265   for (size_t i = 0; i < Class.LateParsedDeclarations.size(); ++i) {
    266     Class.LateParsedDeclarations[i]->ParseLexedMethodDeclarations();
    267   }
    268 
    269   if (HasClassScope)
    270     Actions.ActOnFinishDelayedMemberDeclarations(getCurScope(), Class.TagOrTemplate);
    271 }
    272 
    273 void Parser::ParseLexedMethodDeclaration(LateParsedMethodDeclaration &LM) {
    274   // If this is a member template, introduce the template parameter scope.
    275   ParseScope TemplateScope(this, Scope::TemplateParamScope, LM.TemplateScope);
    276   if (LM.TemplateScope)
    277     Actions.ActOnReenterTemplateScope(getCurScope(), LM.Method);
    278 
    279   // Start the delayed C++ method declaration
    280   Actions.ActOnStartDelayedCXXMethodDeclaration(getCurScope(), LM.Method);
    281 
    282   // Introduce the parameters into scope and parse their default
    283   // arguments.
    284   ParseScope PrototypeScope(this,
    285                             Scope::FunctionPrototypeScope|Scope::DeclScope);
    286   for (unsigned I = 0, N = LM.DefaultArgs.size(); I != N; ++I) {
    287     // Introduce the parameter into scope.
    288     Actions.ActOnDelayedCXXMethodParameter(getCurScope(), LM.DefaultArgs[I].Param);
    289 
    290     if (CachedTokens *Toks = LM.DefaultArgs[I].Toks) {
    291       // Save the current token position.
    292       SourceLocation origLoc = Tok.getLocation();
    293 
    294       // Parse the default argument from its saved token stream.
    295       Toks->push_back(Tok); // So that the current token doesn't get lost
    296       PP.EnterTokenStream(&Toks->front(), Toks->size(), true, false);
    297 
    298       // Consume the previously-pushed token.
    299       ConsumeAnyToken();
    300 
    301       // Consume the '='.
    302       assert(Tok.is(tok::equal) && "Default argument not starting with '='");
    303       SourceLocation EqualLoc = ConsumeToken();
    304 
    305       // The argument isn't actually potentially evaluated unless it is
    306       // used.
    307       EnterExpressionEvaluationContext Eval(Actions,
    308                                             Sema::PotentiallyEvaluatedIfUsed);
    309 
    310       ExprResult DefArgResult(ParseAssignmentExpression());
    311       if (DefArgResult.isInvalid())
    312         Actions.ActOnParamDefaultArgumentError(LM.DefaultArgs[I].Param);
    313       else {
    314         if (Tok.is(tok::cxx_defaultarg_end))
    315           ConsumeToken();
    316         else
    317           Diag(Tok.getLocation(), diag::err_default_arg_unparsed);
    318         Actions.ActOnParamDefaultArgument(LM.DefaultArgs[I].Param, EqualLoc,
    319                                           DefArgResult.take());
    320       }
    321 
    322       assert(!PP.getSourceManager().isBeforeInTranslationUnit(origLoc,
    323                                                          Tok.getLocation()) &&
    324              "ParseAssignmentExpression went over the default arg tokens!");
    325       // There could be leftover tokens (e.g. because of an error).
    326       // Skip through until we reach the original token position.
    327       while (Tok.getLocation() != origLoc && Tok.isNot(tok::eof))
    328         ConsumeAnyToken();
    329 
    330       delete Toks;
    331       LM.DefaultArgs[I].Toks = 0;
    332     }
    333   }
    334   PrototypeScope.Exit();
    335 
    336   // Finish the delayed C++ method declaration.
    337   Actions.ActOnFinishDelayedCXXMethodDeclaration(getCurScope(), LM.Method);
    338 }
    339 
    340 /// ParseLexedMethodDefs - We finished parsing the member specification of a top
    341 /// (non-nested) C++ class. Now go over the stack of lexed methods that were
    342 /// collected during its parsing and parse them all.
    343 void Parser::ParseLexedMethodDefs(ParsingClass &Class) {
    344   bool HasTemplateScope = !Class.TopLevelClass && Class.TemplateScope;
    345   ParseScope ClassTemplateScope(this, Scope::TemplateParamScope, HasTemplateScope);
    346   if (HasTemplateScope)
    347     Actions.ActOnReenterTemplateScope(getCurScope(), Class.TagOrTemplate);
    348 
    349   bool HasClassScope = !Class.TopLevelClass;
    350   ParseScope ClassScope(this, Scope::ClassScope|Scope::DeclScope,
    351                         HasClassScope);
    352 
    353   for (size_t i = 0; i < Class.LateParsedDeclarations.size(); ++i) {
    354     Class.LateParsedDeclarations[i]->ParseLexedMethodDefs();
    355   }
    356 }
    357 
    358 void Parser::ParseLexedMethodDef(LexedMethod &LM) {
    359   // If this is a member template, introduce the template parameter scope.
    360   ParseScope TemplateScope(this, Scope::TemplateParamScope, LM.TemplateScope);
    361   if (LM.TemplateScope)
    362     Actions.ActOnReenterTemplateScope(getCurScope(), LM.D);
    363 
    364   // Save the current token position.
    365   SourceLocation origLoc = Tok.getLocation();
    366 
    367   assert(!LM.Toks.empty() && "Empty body!");
    368   // Append the current token at the end of the new token stream so that it
    369   // doesn't get lost.
    370   LM.Toks.push_back(Tok);
    371   PP.EnterTokenStream(LM.Toks.data(), LM.Toks.size(), true, false);
    372 
    373   // Consume the previously pushed token.
    374   ConsumeAnyToken();
    375   assert((Tok.is(tok::l_brace) || Tok.is(tok::colon) || Tok.is(tok::kw_try))
    376          && "Inline method not starting with '{', ':' or 'try'");
    377 
    378   // Parse the method body. Function body parsing code is similar enough
    379   // to be re-used for method bodies as well.
    380   ParseScope FnScope(this, Scope::FnScope|Scope::DeclScope);
    381   Actions.ActOnStartOfFunctionDef(getCurScope(), LM.D);
    382 
    383   if (Tok.is(tok::kw_try)) {
    384     ParseFunctionTryBlock(LM.D, FnScope);
    385     assert(!PP.getSourceManager().isBeforeInTranslationUnit(origLoc,
    386                                                          Tok.getLocation()) &&
    387            "ParseFunctionTryBlock went over the cached tokens!");
    388     // There could be leftover tokens (e.g. because of an error).
    389     // Skip through until we reach the original token position.
    390     while (Tok.getLocation() != origLoc && Tok.isNot(tok::eof))
    391       ConsumeAnyToken();
    392     return;
    393   }
    394   if (Tok.is(tok::colon)) {
    395     ParseConstructorInitializer(LM.D);
    396 
    397     // Error recovery.
    398     if (!Tok.is(tok::l_brace)) {
    399       FnScope.Exit();
    400       Actions.ActOnFinishFunctionBody(LM.D, 0);
    401       return;
    402     }
    403   } else
    404     Actions.ActOnDefaultCtorInitializers(LM.D);
    405 
    406   ParseFunctionStatementBody(LM.D, FnScope);
    407 
    408   if (Tok.getLocation() != origLoc) {
    409     // Due to parsing error, we either went over the cached tokens or
    410     // there are still cached tokens left. If it's the latter case skip the
    411     // leftover tokens.
    412     // Since this is an uncommon situation that should be avoided, use the
    413     // expensive isBeforeInTranslationUnit call.
    414     if (PP.getSourceManager().isBeforeInTranslationUnit(Tok.getLocation(),
    415                                                         origLoc))
    416       while (Tok.getLocation() != origLoc && Tok.isNot(tok::eof))
    417         ConsumeAnyToken();
    418   }
    419 }
    420 
    421 /// ParseLexedMemberInitializers - We finished parsing the member specification
    422 /// of a top (non-nested) C++ class. Now go over the stack of lexed data member
    423 /// initializers that were collected during its parsing and parse them all.
    424 void Parser::ParseLexedMemberInitializers(ParsingClass &Class) {
    425   bool HasTemplateScope = !Class.TopLevelClass && Class.TemplateScope;
    426   ParseScope ClassTemplateScope(this, Scope::TemplateParamScope,
    427                                 HasTemplateScope);
    428   if (HasTemplateScope)
    429     Actions.ActOnReenterTemplateScope(getCurScope(), Class.TagOrTemplate);
    430 
    431   // Set or update the scope flags to include Scope::ThisScope.
    432   bool AlreadyHasClassScope = Class.TopLevelClass;
    433   unsigned ScopeFlags = Scope::ClassScope|Scope::DeclScope|Scope::ThisScope;
    434   ParseScope ClassScope(this, ScopeFlags, !AlreadyHasClassScope);
    435   ParseScopeFlags ClassScopeFlags(this, ScopeFlags, AlreadyHasClassScope);
    436 
    437   if (!AlreadyHasClassScope)
    438     Actions.ActOnStartDelayedMemberDeclarations(getCurScope(),
    439                                                 Class.TagOrTemplate);
    440 
    441   for (size_t i = 0; i < Class.LateParsedDeclarations.size(); ++i) {
    442     Class.LateParsedDeclarations[i]->ParseLexedMemberInitializers();
    443   }
    444 
    445   if (!AlreadyHasClassScope)
    446     Actions.ActOnFinishDelayedMemberDeclarations(getCurScope(),
    447                                                  Class.TagOrTemplate);
    448 
    449   Actions.ActOnFinishDelayedMemberInitializers(Class.TagOrTemplate);
    450 }
    451 
    452 void Parser::ParseLexedMemberInitializer(LateParsedMemberInitializer &MI) {
    453   if (MI.Field->isInvalidDecl())
    454     return;
    455 
    456   // Append the current token at the end of the new token stream so that it
    457   // doesn't get lost.
    458   MI.Toks.push_back(Tok);
    459   PP.EnterTokenStream(MI.Toks.data(), MI.Toks.size(), true, false);
    460 
    461   // Consume the previously pushed token.
    462   ConsumeAnyToken();
    463 
    464   SourceLocation EqualLoc;
    465   ExprResult Init = ParseCXXMemberInitializer(/*IsFunction=*/false, EqualLoc);
    466 
    467   Actions.ActOnCXXInClassMemberInitializer(MI.Field, EqualLoc, Init.release());
    468 
    469   // The next token should be our artificial terminating EOF token.
    470   if (Tok.isNot(tok::eof)) {
    471     SourceLocation EndLoc = PP.getLocForEndOfToken(PrevTokLocation);
    472     if (!EndLoc.isValid())
    473       EndLoc = Tok.getLocation();
    474     // No fixit; we can't recover as if there were a semicolon here.
    475     Diag(EndLoc, diag::err_expected_semi_decl_list);
    476 
    477     // Consume tokens until we hit the artificial EOF.
    478     while (Tok.isNot(tok::eof))
    479       ConsumeAnyToken();
    480   }
    481   ConsumeAnyToken();
    482 }
    483 
    484 /// ConsumeAndStoreUntil - Consume and store the token at the passed token
    485 /// container until the token 'T' is reached (which gets
    486 /// consumed/stored too, if ConsumeFinalToken).
    487 /// If StopAtSemi is true, then we will stop early at a ';' character.
    488 /// Returns true if token 'T1' or 'T2' was found.
    489 /// NOTE: This is a specialized version of Parser::SkipUntil.
    490 bool Parser::ConsumeAndStoreUntil(tok::TokenKind T1, tok::TokenKind T2,
    491                                   CachedTokens &Toks,
    492                                   bool StopAtSemi, bool ConsumeFinalToken) {
    493   // We always want this function to consume at least one token if the first
    494   // token isn't T and if not at EOF.
    495   bool isFirstTokenConsumed = true;
    496   while (1) {
    497     // If we found one of the tokens, stop and return true.
    498     if (Tok.is(T1) || Tok.is(T2)) {
    499       if (ConsumeFinalToken) {
    500         Toks.push_back(Tok);
    501         ConsumeAnyToken();
    502       }
    503       return true;
    504     }
    505 
    506     switch (Tok.getKind()) {
    507     case tok::eof:
    508       // Ran out of tokens.
    509       return false;
    510 
    511     case tok::l_paren:
    512       // Recursively consume properly-nested parens.
    513       Toks.push_back(Tok);
    514       ConsumeParen();
    515       ConsumeAndStoreUntil(tok::r_paren, Toks, /*StopAtSemi=*/false);
    516       break;
    517     case tok::l_square:
    518       // Recursively consume properly-nested square brackets.
    519       Toks.push_back(Tok);
    520       ConsumeBracket();
    521       ConsumeAndStoreUntil(tok::r_square, Toks, /*StopAtSemi=*/false);
    522       break;
    523     case tok::l_brace:
    524       // Recursively consume properly-nested braces.
    525       Toks.push_back(Tok);
    526       ConsumeBrace();
    527       ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
    528       break;
    529 
    530     // Okay, we found a ']' or '}' or ')', which we think should be balanced.
    531     // Since the user wasn't looking for this token (if they were, it would
    532     // already be handled), this isn't balanced.  If there is a LHS token at a
    533     // higher level, we will assume that this matches the unbalanced token
    534     // and return it.  Otherwise, this is a spurious RHS token, which we skip.
    535     case tok::r_paren:
    536       if (ParenCount && !isFirstTokenConsumed)
    537         return false;  // Matches something.
    538       Toks.push_back(Tok);
    539       ConsumeParen();
    540       break;
    541     case tok::r_square:
    542       if (BracketCount && !isFirstTokenConsumed)
    543         return false;  // Matches something.
    544       Toks.push_back(Tok);
    545       ConsumeBracket();
    546       break;
    547     case tok::r_brace:
    548       if (BraceCount && !isFirstTokenConsumed)
    549         return false;  // Matches something.
    550       Toks.push_back(Tok);
    551       ConsumeBrace();
    552       break;
    553 
    554     case tok::string_literal:
    555     case tok::wide_string_literal:
    556       Toks.push_back(Tok);
    557       ConsumeStringToken();
    558       break;
    559     case tok::semi:
    560       if (StopAtSemi)
    561         return false;
    562       // FALL THROUGH.
    563     default:
    564       // consume this token.
    565       Toks.push_back(Tok);
    566       ConsumeToken();
    567       break;
    568     }
    569     isFirstTokenConsumed = false;
    570   }
    571 }
    572