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/Parser.h"
15 #include "RAIIObjectsForParser.h"
16 #include "clang/AST/DeclTemplate.h"
17 #include "clang/Parse/ParseDiagnostic.h"
18 #include "clang/Sema/DeclSpec.h"
19 #include "clang/Sema/Scope.h"
20 using namespace clang;
21 
22 /// ParseCXXInlineMethodDef - We parsed and verified that the specified
23 /// Declarator is a well formed C++ inline method definition. Now lex its body
24 /// and store its tokens for parsing after the C++ class is complete.
ParseCXXInlineMethodDef(AccessSpecifier AS,AttributeList * AccessAttrs,ParsingDeclarator & D,const ParsedTemplateInfo & TemplateInfo,const VirtSpecifiers & VS,SourceLocation PureSpecLoc)25 NamedDecl *Parser::ParseCXXInlineMethodDef(AccessSpecifier AS,
26                                       AttributeList *AccessAttrs,
27                                       ParsingDeclarator &D,
28                                       const ParsedTemplateInfo &TemplateInfo,
29                                       const VirtSpecifiers& VS,
30                                       SourceLocation PureSpecLoc) {
31   assert(D.isFunctionDeclarator() && "This isn't a function declarator!");
32   assert(Tok.isOneOf(tok::l_brace, tok::colon, tok::kw_try, tok::equal) &&
33          "Current token not a '{', ':', '=', or 'try'!");
34 
35   MultiTemplateParamsArg TemplateParams(
36       TemplateInfo.TemplateParams ? TemplateInfo.TemplateParams->data()
37                                   : nullptr,
38       TemplateInfo.TemplateParams ? TemplateInfo.TemplateParams->size() : 0);
39 
40   NamedDecl *FnD;
41   if (D.getDeclSpec().isFriendSpecified())
42     FnD = Actions.ActOnFriendFunctionDecl(getCurScope(), D,
43                                           TemplateParams);
44   else {
45     FnD = Actions.ActOnCXXMemberDeclarator(getCurScope(), AS, D,
46                                            TemplateParams, nullptr,
47                                            VS, ICIS_NoInit);
48     if (FnD) {
49       Actions.ProcessDeclAttributeList(getCurScope(), FnD, AccessAttrs);
50       if (PureSpecLoc.isValid())
51         Actions.ActOnPureSpecifier(FnD, PureSpecLoc);
52     }
53   }
54 
55   HandleMemberFunctionDeclDelays(D, FnD);
56 
57   D.complete(FnD);
58 
59   if (TryConsumeToken(tok::equal)) {
60     if (!FnD) {
61       SkipUntil(tok::semi);
62       return nullptr;
63     }
64 
65     bool Delete = false;
66     SourceLocation KWLoc;
67     SourceLocation KWEndLoc = Tok.getEndLoc().getLocWithOffset(-1);
68     if (TryConsumeToken(tok::kw_delete, KWLoc)) {
69       Diag(KWLoc, getLangOpts().CPlusPlus11
70                       ? diag::warn_cxx98_compat_defaulted_deleted_function
71                       : diag::ext_defaulted_deleted_function)
72         << 1 /* deleted */;
73       Actions.SetDeclDeleted(FnD, KWLoc);
74       Delete = true;
75       if (auto *DeclAsFunction = dyn_cast<FunctionDecl>(FnD)) {
76         DeclAsFunction->setRangeEnd(KWEndLoc);
77       }
78     } else if (TryConsumeToken(tok::kw_default, KWLoc)) {
79       Diag(KWLoc, getLangOpts().CPlusPlus11
80                       ? diag::warn_cxx98_compat_defaulted_deleted_function
81                       : diag::ext_defaulted_deleted_function)
82         << 0 /* defaulted */;
83       Actions.SetDeclDefaulted(FnD, KWLoc);
84       if (auto *DeclAsFunction = dyn_cast<FunctionDecl>(FnD)) {
85         DeclAsFunction->setRangeEnd(KWEndLoc);
86       }
87     } else {
88       llvm_unreachable("function definition after = not 'delete' or 'default'");
89     }
90 
91     if (Tok.is(tok::comma)) {
92       Diag(KWLoc, diag::err_default_delete_in_multiple_declaration)
93         << Delete;
94       SkipUntil(tok::semi);
95     } else if (ExpectAndConsume(tok::semi, diag::err_expected_after,
96                                 Delete ? "delete" : "default")) {
97       SkipUntil(tok::semi);
98     }
99 
100     return FnD;
101   }
102 
103   // In delayed template parsing mode, if we are within a class template
104   // or if we are about to parse function member template then consume
105   // the tokens and store them for parsing at the end of the translation unit.
106   if (getLangOpts().DelayedTemplateParsing &&
107       D.getFunctionDefinitionKind() == FDK_Definition &&
108       !D.getDeclSpec().isConstexprSpecified() &&
109       !(FnD && FnD->getAsFunction() &&
110         FnD->getAsFunction()->getReturnType()->getContainedAutoType()) &&
111       ((Actions.CurContext->isDependentContext() ||
112         (TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate &&
113          TemplateInfo.Kind != ParsedTemplateInfo::ExplicitSpecialization)) &&
114        !Actions.IsInsideALocalClassWithinATemplateFunction())) {
115 
116     CachedTokens Toks;
117     LexTemplateFunctionForLateParsing(Toks);
118 
119     if (FnD) {
120       FunctionDecl *FD = FnD->getAsFunction();
121       Actions.CheckForFunctionRedefinition(FD);
122       Actions.MarkAsLateParsedTemplate(FD, FnD, Toks);
123     }
124 
125     return FnD;
126   }
127 
128   // Consume the tokens and store them for later parsing.
129 
130   LexedMethod* LM = new LexedMethod(this, FnD);
131   getCurrentClass().LateParsedDeclarations.push_back(LM);
132   LM->TemplateScope = getCurScope()->isTemplateParamScope();
133   CachedTokens &Toks = LM->Toks;
134 
135   tok::TokenKind kind = Tok.getKind();
136   // Consume everything up to (and including) the left brace of the
137   // function body.
138   if (ConsumeAndStoreFunctionPrologue(Toks)) {
139     // We didn't find the left-brace we expected after the
140     // constructor initializer; we already printed an error, and it's likely
141     // impossible to recover, so don't try to parse this method later.
142     // Skip over the rest of the decl and back to somewhere that looks
143     // reasonable.
144     SkipMalformedDecl();
145     delete getCurrentClass().LateParsedDeclarations.back();
146     getCurrentClass().LateParsedDeclarations.pop_back();
147     return FnD;
148   } else {
149     // Consume everything up to (and including) the matching right brace.
150     ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
151   }
152 
153   // If we're in a function-try-block, we need to store all the catch blocks.
154   if (kind == tok::kw_try) {
155     while (Tok.is(tok::kw_catch)) {
156       ConsumeAndStoreUntil(tok::l_brace, Toks, /*StopAtSemi=*/false);
157       ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
158     }
159   }
160 
161   if (FnD) {
162     // If this is a friend function, mark that it's late-parsed so that
163     // it's still known to be a definition even before we attach the
164     // parsed body.  Sema needs to treat friend function definitions
165     // differently during template instantiation, and it's possible for
166     // the containing class to be instantiated before all its member
167     // function definitions are parsed.
168     //
169     // If you remove this, you can remove the code that clears the flag
170     // after parsing the member.
171     if (D.getDeclSpec().isFriendSpecified()) {
172       FunctionDecl *FD = FnD->getAsFunction();
173       Actions.CheckForFunctionRedefinition(FD);
174       FD->setLateTemplateParsed(true);
175     }
176   } else {
177     // If semantic analysis could not build a function declaration,
178     // just throw away the late-parsed declaration.
179     delete getCurrentClass().LateParsedDeclarations.back();
180     getCurrentClass().LateParsedDeclarations.pop_back();
181   }
182 
183   return FnD;
184 }
185 
186 /// ParseCXXNonStaticMemberInitializer - We parsed and verified that the
187 /// specified Declarator is a well formed C++ non-static data member
188 /// declaration. Now lex its initializer and store its tokens for parsing
189 /// after the class is complete.
ParseCXXNonStaticMemberInitializer(Decl * VarD)190 void Parser::ParseCXXNonStaticMemberInitializer(Decl *VarD) {
191   assert(Tok.isOneOf(tok::l_brace, tok::equal) &&
192          "Current token not a '{' or '='!");
193 
194   LateParsedMemberInitializer *MI =
195     new LateParsedMemberInitializer(this, VarD);
196   getCurrentClass().LateParsedDeclarations.push_back(MI);
197   CachedTokens &Toks = MI->Toks;
198 
199   tok::TokenKind kind = Tok.getKind();
200   if (kind == tok::equal) {
201     Toks.push_back(Tok);
202     ConsumeToken();
203   }
204 
205   if (kind == tok::l_brace) {
206     // Begin by storing the '{' token.
207     Toks.push_back(Tok);
208     ConsumeBrace();
209 
210     // Consume everything up to (and including) the matching right brace.
211     ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/true);
212   } else {
213     // Consume everything up to (but excluding) the comma or semicolon.
214     ConsumeAndStoreInitializer(Toks, CIK_DefaultInitializer);
215   }
216 
217   // Store an artificial EOF token to ensure that we don't run off the end of
218   // the initializer when we come to parse it.
219   Token Eof;
220   Eof.startToken();
221   Eof.setKind(tok::eof);
222   Eof.setLocation(Tok.getLocation());
223   Eof.setEofData(VarD);
224   Toks.push_back(Eof);
225 }
226 
~LateParsedDeclaration()227 Parser::LateParsedDeclaration::~LateParsedDeclaration() {}
ParseLexedMethodDeclarations()228 void Parser::LateParsedDeclaration::ParseLexedMethodDeclarations() {}
ParseLexedMemberInitializers()229 void Parser::LateParsedDeclaration::ParseLexedMemberInitializers() {}
ParseLexedMethodDefs()230 void Parser::LateParsedDeclaration::ParseLexedMethodDefs() {}
231 
LateParsedClass(Parser * P,ParsingClass * C)232 Parser::LateParsedClass::LateParsedClass(Parser *P, ParsingClass *C)
233   : Self(P), Class(C) {}
234 
~LateParsedClass()235 Parser::LateParsedClass::~LateParsedClass() {
236   Self->DeallocateParsedClasses(Class);
237 }
238 
ParseLexedMethodDeclarations()239 void Parser::LateParsedClass::ParseLexedMethodDeclarations() {
240   Self->ParseLexedMethodDeclarations(*Class);
241 }
242 
ParseLexedMemberInitializers()243 void Parser::LateParsedClass::ParseLexedMemberInitializers() {
244   Self->ParseLexedMemberInitializers(*Class);
245 }
246 
ParseLexedMethodDefs()247 void Parser::LateParsedClass::ParseLexedMethodDefs() {
248   Self->ParseLexedMethodDefs(*Class);
249 }
250 
ParseLexedMethodDeclarations()251 void Parser::LateParsedMethodDeclaration::ParseLexedMethodDeclarations() {
252   Self->ParseLexedMethodDeclaration(*this);
253 }
254 
ParseLexedMethodDefs()255 void Parser::LexedMethod::ParseLexedMethodDefs() {
256   Self->ParseLexedMethodDef(*this);
257 }
258 
ParseLexedMemberInitializers()259 void Parser::LateParsedMemberInitializer::ParseLexedMemberInitializers() {
260   Self->ParseLexedMemberInitializer(*this);
261 }
262 
263 /// ParseLexedMethodDeclarations - We finished parsing the member
264 /// specification of a top (non-nested) C++ class. Now go over the
265 /// stack of method declarations with some parts for which parsing was
266 /// delayed (such as default arguments) and parse them.
ParseLexedMethodDeclarations(ParsingClass & Class)267 void Parser::ParseLexedMethodDeclarations(ParsingClass &Class) {
268   bool HasTemplateScope = !Class.TopLevelClass && Class.TemplateScope;
269   ParseScope ClassTemplateScope(this, Scope::TemplateParamScope,
270                                 HasTemplateScope);
271   TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
272   if (HasTemplateScope) {
273     Actions.ActOnReenterTemplateScope(getCurScope(), Class.TagOrTemplate);
274     ++CurTemplateDepthTracker;
275   }
276 
277   // The current scope is still active if we're the top-level class.
278   // Otherwise we'll need to push and enter a new scope.
279   bool HasClassScope = !Class.TopLevelClass;
280   ParseScope ClassScope(this, Scope::ClassScope|Scope::DeclScope,
281                         HasClassScope);
282   if (HasClassScope)
283     Actions.ActOnStartDelayedMemberDeclarations(getCurScope(),
284                                                 Class.TagOrTemplate);
285 
286   for (size_t i = 0; i < Class.LateParsedDeclarations.size(); ++i) {
287     Class.LateParsedDeclarations[i]->ParseLexedMethodDeclarations();
288   }
289 
290   if (HasClassScope)
291     Actions.ActOnFinishDelayedMemberDeclarations(getCurScope(),
292                                                  Class.TagOrTemplate);
293 }
294 
ParseLexedMethodDeclaration(LateParsedMethodDeclaration & LM)295 void Parser::ParseLexedMethodDeclaration(LateParsedMethodDeclaration &LM) {
296   // If this is a member template, introduce the template parameter scope.
297   ParseScope TemplateScope(this, Scope::TemplateParamScope, LM.TemplateScope);
298   TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
299   if (LM.TemplateScope) {
300     Actions.ActOnReenterTemplateScope(getCurScope(), LM.Method);
301     ++CurTemplateDepthTracker;
302   }
303   // Start the delayed C++ method declaration
304   Actions.ActOnStartDelayedCXXMethodDeclaration(getCurScope(), LM.Method);
305 
306   // Introduce the parameters into scope and parse their default
307   // arguments.
308   ParseScope PrototypeScope(this, Scope::FunctionPrototypeScope |
309                             Scope::FunctionDeclarationScope | Scope::DeclScope);
310   for (unsigned I = 0, N = LM.DefaultArgs.size(); I != N; ++I) {
311     auto Param = cast<ParmVarDecl>(LM.DefaultArgs[I].Param);
312     // Introduce the parameter into scope.
313     bool HasUnparsed = Param->hasUnparsedDefaultArg();
314     Actions.ActOnDelayedCXXMethodParameter(getCurScope(), Param);
315     if (CachedTokens *Toks = LM.DefaultArgs[I].Toks) {
316       // Mark the end of the default argument so that we know when to stop when
317       // we parse it later on.
318       Token LastDefaultArgToken = Toks->back();
319       Token DefArgEnd;
320       DefArgEnd.startToken();
321       DefArgEnd.setKind(tok::eof);
322       DefArgEnd.setLocation(LastDefaultArgToken.getEndLoc());
323       DefArgEnd.setEofData(Param);
324       Toks->push_back(DefArgEnd);
325 
326       // Parse the default argument from its saved token stream.
327       Toks->push_back(Tok); // So that the current token doesn't get lost
328       PP.EnterTokenStream(&Toks->front(), Toks->size(), true, false);
329 
330       // Consume the previously-pushed token.
331       ConsumeAnyToken();
332 
333       // Consume the '='.
334       assert(Tok.is(tok::equal) && "Default argument not starting with '='");
335       SourceLocation EqualLoc = ConsumeToken();
336 
337       // The argument isn't actually potentially evaluated unless it is
338       // used.
339       EnterExpressionEvaluationContext Eval(Actions,
340                                             Sema::PotentiallyEvaluatedIfUsed,
341                                             Param);
342 
343       ExprResult DefArgResult;
344       if (getLangOpts().CPlusPlus11 && Tok.is(tok::l_brace)) {
345         Diag(Tok, diag::warn_cxx98_compat_generalized_initializer_lists);
346         DefArgResult = ParseBraceInitializer();
347       } else
348         DefArgResult = ParseAssignmentExpression();
349       DefArgResult = Actions.CorrectDelayedTyposInExpr(DefArgResult);
350       if (DefArgResult.isInvalid()) {
351         Actions.ActOnParamDefaultArgumentError(Param, EqualLoc);
352       } else {
353         if (Tok.isNot(tok::eof) || Tok.getEofData() != Param) {
354           // The last two tokens are the terminator and the saved value of
355           // Tok; the last token in the default argument is the one before
356           // those.
357           assert(Toks->size() >= 3 && "expected a token in default arg");
358           Diag(Tok.getLocation(), diag::err_default_arg_unparsed)
359             << SourceRange(Tok.getLocation(),
360                            (*Toks)[Toks->size() - 3].getLocation());
361         }
362         Actions.ActOnParamDefaultArgument(Param, EqualLoc,
363                                           DefArgResult.get());
364       }
365 
366       // There could be leftover tokens (e.g. because of an error).
367       // Skip through until we reach the 'end of default argument' token.
368       while (Tok.isNot(tok::eof))
369         ConsumeAnyToken();
370 
371       if (Tok.is(tok::eof) && Tok.getEofData() == Param)
372         ConsumeAnyToken();
373 
374       delete Toks;
375       LM.DefaultArgs[I].Toks = nullptr;
376     } else if (HasUnparsed) {
377       assert(Param->hasInheritedDefaultArg());
378       FunctionDecl *Old = cast<FunctionDecl>(LM.Method)->getPreviousDecl();
379       ParmVarDecl *OldParam = Old->getParamDecl(I);
380       assert (!OldParam->hasUnparsedDefaultArg());
381       if (OldParam->hasUninstantiatedDefaultArg())
382         Param->setUninstantiatedDefaultArg(
383                                       Param->getUninstantiatedDefaultArg());
384       else
385         Param->setDefaultArg(OldParam->getInit());
386     }
387   }
388 
389   // Parse a delayed exception-specification, if there is one.
390   if (CachedTokens *Toks = LM.ExceptionSpecTokens) {
391     // Add the 'stop' token.
392     Token LastExceptionSpecToken = Toks->back();
393     Token ExceptionSpecEnd;
394     ExceptionSpecEnd.startToken();
395     ExceptionSpecEnd.setKind(tok::eof);
396     ExceptionSpecEnd.setLocation(LastExceptionSpecToken.getEndLoc());
397     ExceptionSpecEnd.setEofData(LM.Method);
398     Toks->push_back(ExceptionSpecEnd);
399 
400     // Parse the default argument from its saved token stream.
401     Toks->push_back(Tok); // So that the current token doesn't get lost
402     PP.EnterTokenStream(&Toks->front(), Toks->size(), true, false);
403 
404     // Consume the previously-pushed token.
405     ConsumeAnyToken();
406 
407     // C++11 [expr.prim.general]p3:
408     //   If a declaration declares a member function or member function
409     //   template of a class X, the expression this is a prvalue of type
410     //   "pointer to cv-qualifier-seq X" between the optional cv-qualifer-seq
411     //   and the end of the function-definition, member-declarator, or
412     //   declarator.
413     CXXMethodDecl *Method;
414     if (FunctionTemplateDecl *FunTmpl
415           = dyn_cast<FunctionTemplateDecl>(LM.Method))
416       Method = cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
417     else
418       Method = cast<CXXMethodDecl>(LM.Method);
419 
420     Sema::CXXThisScopeRAII ThisScope(Actions, Method->getParent(),
421                                      Method->getTypeQualifiers(),
422                                      getLangOpts().CPlusPlus11);
423 
424     // Parse the exception-specification.
425     SourceRange SpecificationRange;
426     SmallVector<ParsedType, 4> DynamicExceptions;
427     SmallVector<SourceRange, 4> DynamicExceptionRanges;
428     ExprResult NoexceptExpr;
429     CachedTokens *ExceptionSpecTokens;
430 
431     ExceptionSpecificationType EST
432       = tryParseExceptionSpecification(/*Delayed=*/false, SpecificationRange,
433                                        DynamicExceptions,
434                                        DynamicExceptionRanges, NoexceptExpr,
435                                        ExceptionSpecTokens);
436 
437     if (Tok.isNot(tok::eof) || Tok.getEofData() != LM.Method)
438       Diag(Tok.getLocation(), diag::err_except_spec_unparsed);
439 
440     // Attach the exception-specification to the method.
441     Actions.actOnDelayedExceptionSpecification(LM.Method, EST,
442                                                SpecificationRange,
443                                                DynamicExceptions,
444                                                DynamicExceptionRanges,
445                                                NoexceptExpr.isUsable()?
446                                                  NoexceptExpr.get() : nullptr);
447 
448     // There could be leftover tokens (e.g. because of an error).
449     // Skip through until we reach the original token position.
450     while (Tok.isNot(tok::eof))
451       ConsumeAnyToken();
452 
453     // Clean up the remaining EOF token.
454     if (Tok.is(tok::eof) && Tok.getEofData() == LM.Method)
455       ConsumeAnyToken();
456 
457     delete Toks;
458     LM.ExceptionSpecTokens = nullptr;
459   }
460 
461   PrototypeScope.Exit();
462 
463   // Finish the delayed C++ method declaration.
464   Actions.ActOnFinishDelayedCXXMethodDeclaration(getCurScope(), LM.Method);
465 }
466 
467 /// ParseLexedMethodDefs - We finished parsing the member specification of a top
468 /// (non-nested) C++ class. Now go over the stack of lexed methods that were
469 /// collected during its parsing and parse them all.
ParseLexedMethodDefs(ParsingClass & Class)470 void Parser::ParseLexedMethodDefs(ParsingClass &Class) {
471   bool HasTemplateScope = !Class.TopLevelClass && Class.TemplateScope;
472   ParseScope ClassTemplateScope(this, Scope::TemplateParamScope, HasTemplateScope);
473   TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
474   if (HasTemplateScope) {
475     Actions.ActOnReenterTemplateScope(getCurScope(), Class.TagOrTemplate);
476     ++CurTemplateDepthTracker;
477   }
478   bool HasClassScope = !Class.TopLevelClass;
479   ParseScope ClassScope(this, Scope::ClassScope|Scope::DeclScope,
480                         HasClassScope);
481 
482   for (size_t i = 0; i < Class.LateParsedDeclarations.size(); ++i) {
483     Class.LateParsedDeclarations[i]->ParseLexedMethodDefs();
484   }
485 }
486 
ParseLexedMethodDef(LexedMethod & LM)487 void Parser::ParseLexedMethodDef(LexedMethod &LM) {
488   // If this is a member template, introduce the template parameter scope.
489   ParseScope TemplateScope(this, Scope::TemplateParamScope, LM.TemplateScope);
490   TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
491   if (LM.TemplateScope) {
492     Actions.ActOnReenterTemplateScope(getCurScope(), LM.D);
493     ++CurTemplateDepthTracker;
494   }
495 
496   assert(!LM.Toks.empty() && "Empty body!");
497   Token LastBodyToken = LM.Toks.back();
498   Token BodyEnd;
499   BodyEnd.startToken();
500   BodyEnd.setKind(tok::eof);
501   BodyEnd.setLocation(LastBodyToken.getEndLoc());
502   BodyEnd.setEofData(LM.D);
503   LM.Toks.push_back(BodyEnd);
504   // Append the current token at the end of the new token stream so that it
505   // doesn't get lost.
506   LM.Toks.push_back(Tok);
507   PP.EnterTokenStream(LM.Toks.data(), LM.Toks.size(), true, false);
508 
509   // Consume the previously pushed token.
510   ConsumeAnyToken(/*ConsumeCodeCompletionTok=*/true);
511   assert(Tok.isOneOf(tok::l_brace, tok::colon, tok::kw_try)
512          && "Inline method not starting with '{', ':' or 'try'");
513 
514   // Parse the method body. Function body parsing code is similar enough
515   // to be re-used for method bodies as well.
516   ParseScope FnScope(this, Scope::FnScope|Scope::DeclScope);
517   Actions.ActOnStartOfFunctionDef(getCurScope(), LM.D);
518 
519   if (Tok.is(tok::kw_try)) {
520     ParseFunctionTryBlock(LM.D, FnScope);
521 
522     while (Tok.isNot(tok::eof))
523       ConsumeAnyToken();
524 
525     if (Tok.is(tok::eof) && Tok.getEofData() == LM.D)
526       ConsumeAnyToken();
527     return;
528   }
529   if (Tok.is(tok::colon)) {
530     ParseConstructorInitializer(LM.D);
531 
532     // Error recovery.
533     if (!Tok.is(tok::l_brace)) {
534       FnScope.Exit();
535       Actions.ActOnFinishFunctionBody(LM.D, nullptr);
536 
537       while (Tok.isNot(tok::eof))
538         ConsumeAnyToken();
539 
540       if (Tok.is(tok::eof) && Tok.getEofData() == LM.D)
541         ConsumeAnyToken();
542       return;
543     }
544   } else
545     Actions.ActOnDefaultCtorInitializers(LM.D);
546 
547   assert((Actions.getDiagnostics().hasErrorOccurred() ||
548           !isa<FunctionTemplateDecl>(LM.D) ||
549           cast<FunctionTemplateDecl>(LM.D)->getTemplateParameters()->getDepth()
550             < TemplateParameterDepth) &&
551          "TemplateParameterDepth should be greater than the depth of "
552          "current template being instantiated!");
553 
554   ParseFunctionStatementBody(LM.D, FnScope);
555 
556   // Clear the late-template-parsed bit if we set it before.
557   if (LM.D)
558     LM.D->getAsFunction()->setLateTemplateParsed(false);
559 
560   while (Tok.isNot(tok::eof))
561     ConsumeAnyToken();
562 
563   if (Tok.is(tok::eof) && Tok.getEofData() == LM.D)
564     ConsumeAnyToken();
565 
566   if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(LM.D))
567     Actions.ActOnFinishInlineMethodDef(MD);
568 }
569 
570 /// ParseLexedMemberInitializers - We finished parsing the member specification
571 /// of a top (non-nested) C++ class. Now go over the stack of lexed data member
572 /// initializers that were collected during its parsing and parse them all.
ParseLexedMemberInitializers(ParsingClass & Class)573 void Parser::ParseLexedMemberInitializers(ParsingClass &Class) {
574   bool HasTemplateScope = !Class.TopLevelClass && Class.TemplateScope;
575   ParseScope ClassTemplateScope(this, Scope::TemplateParamScope,
576                                 HasTemplateScope);
577   TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
578   if (HasTemplateScope) {
579     Actions.ActOnReenterTemplateScope(getCurScope(), Class.TagOrTemplate);
580     ++CurTemplateDepthTracker;
581   }
582   // Set or update the scope flags.
583   bool AlreadyHasClassScope = Class.TopLevelClass;
584   unsigned ScopeFlags = Scope::ClassScope|Scope::DeclScope;
585   ParseScope ClassScope(this, ScopeFlags, !AlreadyHasClassScope);
586   ParseScopeFlags ClassScopeFlags(this, ScopeFlags, AlreadyHasClassScope);
587 
588   if (!AlreadyHasClassScope)
589     Actions.ActOnStartDelayedMemberDeclarations(getCurScope(),
590                                                 Class.TagOrTemplate);
591 
592   if (!Class.LateParsedDeclarations.empty()) {
593     // C++11 [expr.prim.general]p4:
594     //   Otherwise, if a member-declarator declares a non-static data member
595     //  (9.2) of a class X, the expression this is a prvalue of type "pointer
596     //  to X" within the optional brace-or-equal-initializer. It shall not
597     //  appear elsewhere in the member-declarator.
598     Sema::CXXThisScopeRAII ThisScope(Actions, Class.TagOrTemplate,
599                                      /*TypeQuals=*/(unsigned)0);
600 
601     for (size_t i = 0; i < Class.LateParsedDeclarations.size(); ++i) {
602       Class.LateParsedDeclarations[i]->ParseLexedMemberInitializers();
603     }
604   }
605 
606   if (!AlreadyHasClassScope)
607     Actions.ActOnFinishDelayedMemberDeclarations(getCurScope(),
608                                                  Class.TagOrTemplate);
609 
610   Actions.ActOnFinishDelayedMemberInitializers(Class.TagOrTemplate);
611 }
612 
ParseLexedMemberInitializer(LateParsedMemberInitializer & MI)613 void Parser::ParseLexedMemberInitializer(LateParsedMemberInitializer &MI) {
614   if (!MI.Field || MI.Field->isInvalidDecl())
615     return;
616 
617   // Append the current token at the end of the new token stream so that it
618   // doesn't get lost.
619   MI.Toks.push_back(Tok);
620   PP.EnterTokenStream(MI.Toks.data(), MI.Toks.size(), true, false);
621 
622   // Consume the previously pushed token.
623   ConsumeAnyToken(/*ConsumeCodeCompletionTok=*/true);
624 
625   SourceLocation EqualLoc;
626 
627   Actions.ActOnStartCXXInClassMemberInitializer();
628 
629   ExprResult Init = ParseCXXMemberInitializer(MI.Field, /*IsFunction=*/false,
630                                               EqualLoc);
631 
632   Actions.ActOnFinishCXXInClassMemberInitializer(MI.Field, EqualLoc,
633                                                  Init.get());
634 
635   // The next token should be our artificial terminating EOF token.
636   if (Tok.isNot(tok::eof)) {
637     if (!Init.isInvalid()) {
638       SourceLocation EndLoc = PP.getLocForEndOfToken(PrevTokLocation);
639       if (!EndLoc.isValid())
640         EndLoc = Tok.getLocation();
641       // No fixit; we can't recover as if there were a semicolon here.
642       Diag(EndLoc, diag::err_expected_semi_decl_list);
643     }
644 
645     // Consume tokens until we hit the artificial EOF.
646     while (Tok.isNot(tok::eof))
647       ConsumeAnyToken();
648   }
649   // Make sure this is *our* artificial EOF token.
650   if (Tok.getEofData() == MI.Field)
651     ConsumeAnyToken();
652 }
653 
654 /// ConsumeAndStoreUntil - Consume and store the token at the passed token
655 /// container until the token 'T' is reached (which gets
656 /// consumed/stored too, if ConsumeFinalToken).
657 /// If StopAtSemi is true, then we will stop early at a ';' character.
658 /// Returns true if token 'T1' or 'T2' was found.
659 /// NOTE: This is a specialized version of Parser::SkipUntil.
ConsumeAndStoreUntil(tok::TokenKind T1,tok::TokenKind T2,CachedTokens & Toks,bool StopAtSemi,bool ConsumeFinalToken)660 bool Parser::ConsumeAndStoreUntil(tok::TokenKind T1, tok::TokenKind T2,
661                                   CachedTokens &Toks,
662                                   bool StopAtSemi, bool ConsumeFinalToken) {
663   // We always want this function to consume at least one token if the first
664   // token isn't T and if not at EOF.
665   bool isFirstTokenConsumed = true;
666   while (1) {
667     // If we found one of the tokens, stop and return true.
668     if (Tok.is(T1) || Tok.is(T2)) {
669       if (ConsumeFinalToken) {
670         Toks.push_back(Tok);
671         ConsumeAnyToken();
672       }
673       return true;
674     }
675 
676     switch (Tok.getKind()) {
677     case tok::eof:
678     case tok::annot_module_begin:
679     case tok::annot_module_end:
680     case tok::annot_module_include:
681       // Ran out of tokens.
682       return false;
683 
684     case tok::l_paren:
685       // Recursively consume properly-nested parens.
686       Toks.push_back(Tok);
687       ConsumeParen();
688       ConsumeAndStoreUntil(tok::r_paren, Toks, /*StopAtSemi=*/false);
689       break;
690     case tok::l_square:
691       // Recursively consume properly-nested square brackets.
692       Toks.push_back(Tok);
693       ConsumeBracket();
694       ConsumeAndStoreUntil(tok::r_square, Toks, /*StopAtSemi=*/false);
695       break;
696     case tok::l_brace:
697       // Recursively consume properly-nested braces.
698       Toks.push_back(Tok);
699       ConsumeBrace();
700       ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
701       break;
702 
703     // Okay, we found a ']' or '}' or ')', which we think should be balanced.
704     // Since the user wasn't looking for this token (if they were, it would
705     // already be handled), this isn't balanced.  If there is a LHS token at a
706     // higher level, we will assume that this matches the unbalanced token
707     // and return it.  Otherwise, this is a spurious RHS token, which we skip.
708     case tok::r_paren:
709       if (ParenCount && !isFirstTokenConsumed)
710         return false;  // Matches something.
711       Toks.push_back(Tok);
712       ConsumeParen();
713       break;
714     case tok::r_square:
715       if (BracketCount && !isFirstTokenConsumed)
716         return false;  // Matches something.
717       Toks.push_back(Tok);
718       ConsumeBracket();
719       break;
720     case tok::r_brace:
721       if (BraceCount && !isFirstTokenConsumed)
722         return false;  // Matches something.
723       Toks.push_back(Tok);
724       ConsumeBrace();
725       break;
726 
727     case tok::code_completion:
728       Toks.push_back(Tok);
729       ConsumeCodeCompletionToken();
730       break;
731 
732     case tok::string_literal:
733     case tok::wide_string_literal:
734     case tok::utf8_string_literal:
735     case tok::utf16_string_literal:
736     case tok::utf32_string_literal:
737       Toks.push_back(Tok);
738       ConsumeStringToken();
739       break;
740     case tok::semi:
741       if (StopAtSemi)
742         return false;
743       // FALL THROUGH.
744     default:
745       // consume this token.
746       Toks.push_back(Tok);
747       ConsumeToken();
748       break;
749     }
750     isFirstTokenConsumed = false;
751   }
752 }
753 
754 /// \brief Consume tokens and store them in the passed token container until
755 /// we've passed the try keyword and constructor initializers and have consumed
756 /// the opening brace of the function body. The opening brace will be consumed
757 /// if and only if there was no error.
758 ///
759 /// \return True on error.
ConsumeAndStoreFunctionPrologue(CachedTokens & Toks)760 bool Parser::ConsumeAndStoreFunctionPrologue(CachedTokens &Toks) {
761   if (Tok.is(tok::kw_try)) {
762     Toks.push_back(Tok);
763     ConsumeToken();
764   }
765 
766   if (Tok.isNot(tok::colon)) {
767     // Easy case, just a function body.
768 
769     // Grab any remaining garbage to be diagnosed later. We stop when we reach a
770     // brace: an opening one is the function body, while a closing one probably
771     // means we've reached the end of the class.
772     ConsumeAndStoreUntil(tok::l_brace, tok::r_brace, Toks,
773                          /*StopAtSemi=*/true,
774                          /*ConsumeFinalToken=*/false);
775     if (Tok.isNot(tok::l_brace))
776       return Diag(Tok.getLocation(), diag::err_expected) << tok::l_brace;
777 
778     Toks.push_back(Tok);
779     ConsumeBrace();
780     return false;
781   }
782 
783   Toks.push_back(Tok);
784   ConsumeToken();
785 
786   // We can't reliably skip over a mem-initializer-id, because it could be
787   // a template-id involving not-yet-declared names. Given:
788   //
789   //   S ( ) : a < b < c > ( e )
790   //
791   // 'e' might be an initializer or part of a template argument, depending
792   // on whether 'b' is a template.
793 
794   // Track whether we might be inside a template argument. We can give
795   // significantly better diagnostics if we know that we're not.
796   bool MightBeTemplateArgument = false;
797 
798   while (true) {
799     // Skip over the mem-initializer-id, if possible.
800     if (Tok.is(tok::kw_decltype)) {
801       Toks.push_back(Tok);
802       SourceLocation OpenLoc = ConsumeToken();
803       if (Tok.isNot(tok::l_paren))
804         return Diag(Tok.getLocation(), diag::err_expected_lparen_after)
805                  << "decltype";
806       Toks.push_back(Tok);
807       ConsumeParen();
808       if (!ConsumeAndStoreUntil(tok::r_paren, Toks, /*StopAtSemi=*/true)) {
809         Diag(Tok.getLocation(), diag::err_expected) << tok::r_paren;
810         Diag(OpenLoc, diag::note_matching) << tok::l_paren;
811         return true;
812       }
813     }
814     do {
815       // Walk over a component of a nested-name-specifier.
816       if (Tok.is(tok::coloncolon)) {
817         Toks.push_back(Tok);
818         ConsumeToken();
819 
820         if (Tok.is(tok::kw_template)) {
821           Toks.push_back(Tok);
822           ConsumeToken();
823         }
824       }
825 
826       if (Tok.isOneOf(tok::identifier, tok::kw_template)) {
827         Toks.push_back(Tok);
828         ConsumeToken();
829       } else if (Tok.is(tok::code_completion)) {
830         Toks.push_back(Tok);
831         ConsumeCodeCompletionToken();
832         // Consume the rest of the initializers permissively.
833         // FIXME: We should be able to perform code-completion here even if
834         //        there isn't a subsequent '{' token.
835         MightBeTemplateArgument = true;
836         break;
837       } else {
838         break;
839       }
840     } while (Tok.is(tok::coloncolon));
841 
842     if (Tok.is(tok::less))
843       MightBeTemplateArgument = true;
844 
845     if (MightBeTemplateArgument) {
846       // We may be inside a template argument list. Grab up to the start of the
847       // next parenthesized initializer or braced-init-list. This *might* be the
848       // initializer, or it might be a subexpression in the template argument
849       // list.
850       // FIXME: Count angle brackets, and clear MightBeTemplateArgument
851       //        if all angles are closed.
852       if (!ConsumeAndStoreUntil(tok::l_paren, tok::l_brace, Toks,
853                                 /*StopAtSemi=*/true,
854                                 /*ConsumeFinalToken=*/false)) {
855         // We're not just missing the initializer, we're also missing the
856         // function body!
857         return Diag(Tok.getLocation(), diag::err_expected) << tok::l_brace;
858       }
859     } else if (Tok.isNot(tok::l_paren) && Tok.isNot(tok::l_brace)) {
860       // We found something weird in a mem-initializer-id.
861       if (getLangOpts().CPlusPlus11)
862         return Diag(Tok.getLocation(), diag::err_expected_either)
863                << tok::l_paren << tok::l_brace;
864       else
865         return Diag(Tok.getLocation(), diag::err_expected) << tok::l_paren;
866     }
867 
868     tok::TokenKind kind = Tok.getKind();
869     Toks.push_back(Tok);
870     bool IsLParen = (kind == tok::l_paren);
871     SourceLocation OpenLoc = Tok.getLocation();
872 
873     if (IsLParen) {
874       ConsumeParen();
875     } else {
876       assert(kind == tok::l_brace && "Must be left paren or brace here.");
877       ConsumeBrace();
878       // In C++03, this has to be the start of the function body, which
879       // means the initializer is malformed; we'll diagnose it later.
880       if (!getLangOpts().CPlusPlus11)
881         return false;
882     }
883 
884     // Grab the initializer (or the subexpression of the template argument).
885     // FIXME: If we support lambdas here, we'll need to set StopAtSemi to false
886     //        if we might be inside the braces of a lambda-expression.
887     tok::TokenKind CloseKind = IsLParen ? tok::r_paren : tok::r_brace;
888     if (!ConsumeAndStoreUntil(CloseKind, Toks, /*StopAtSemi=*/true)) {
889       Diag(Tok, diag::err_expected) << CloseKind;
890       Diag(OpenLoc, diag::note_matching) << kind;
891       return true;
892     }
893 
894     // Grab pack ellipsis, if present.
895     if (Tok.is(tok::ellipsis)) {
896       Toks.push_back(Tok);
897       ConsumeToken();
898     }
899 
900     // If we know we just consumed a mem-initializer, we must have ',' or '{'
901     // next.
902     if (Tok.is(tok::comma)) {
903       Toks.push_back(Tok);
904       ConsumeToken();
905     } else if (Tok.is(tok::l_brace)) {
906       // This is the function body if the ')' or '}' is immediately followed by
907       // a '{'. That cannot happen within a template argument, apart from the
908       // case where a template argument contains a compound literal:
909       //
910       //   S ( ) : a < b < c > ( d ) { }
911       //   // End of declaration, or still inside the template argument?
912       //
913       // ... and the case where the template argument contains a lambda:
914       //
915       //   S ( ) : a < 0 && b < c > ( d ) + [ ] ( ) { return 0; }
916       //     ( ) > ( ) { }
917       //
918       // FIXME: Disambiguate these cases. Note that the latter case is probably
919       //        going to be made ill-formed by core issue 1607.
920       Toks.push_back(Tok);
921       ConsumeBrace();
922       return false;
923     } else if (!MightBeTemplateArgument) {
924       return Diag(Tok.getLocation(), diag::err_expected_either) << tok::l_brace
925                                                                 << tok::comma;
926     }
927   }
928 }
929 
930 /// \brief Consume and store tokens from the '?' to the ':' in a conditional
931 /// expression.
ConsumeAndStoreConditional(CachedTokens & Toks)932 bool Parser::ConsumeAndStoreConditional(CachedTokens &Toks) {
933   // Consume '?'.
934   assert(Tok.is(tok::question));
935   Toks.push_back(Tok);
936   ConsumeToken();
937 
938   while (Tok.isNot(tok::colon)) {
939     if (!ConsumeAndStoreUntil(tok::question, tok::colon, Toks,
940                               /*StopAtSemi=*/true,
941                               /*ConsumeFinalToken=*/false))
942       return false;
943 
944     // If we found a nested conditional, consume it.
945     if (Tok.is(tok::question) && !ConsumeAndStoreConditional(Toks))
946       return false;
947   }
948 
949   // Consume ':'.
950   Toks.push_back(Tok);
951   ConsumeToken();
952   return true;
953 }
954 
955 /// \brief A tentative parsing action that can also revert token annotations.
956 class Parser::UnannotatedTentativeParsingAction : public TentativeParsingAction {
957 public:
UnannotatedTentativeParsingAction(Parser & Self,tok::TokenKind EndKind)958   explicit UnannotatedTentativeParsingAction(Parser &Self,
959                                              tok::TokenKind EndKind)
960       : TentativeParsingAction(Self), Self(Self), EndKind(EndKind) {
961     // Stash away the old token stream, so we can restore it once the
962     // tentative parse is complete.
963     TentativeParsingAction Inner(Self);
964     Self.ConsumeAndStoreUntil(EndKind, Toks, true, /*ConsumeFinalToken*/false);
965     Inner.Revert();
966   }
967 
RevertAnnotations()968   void RevertAnnotations() {
969     Revert();
970 
971     // Put back the original tokens.
972     Self.SkipUntil(EndKind, StopAtSemi | StopBeforeMatch);
973     if (Toks.size()) {
974       Token *Buffer = new Token[Toks.size()];
975       std::copy(Toks.begin() + 1, Toks.end(), Buffer);
976       Buffer[Toks.size() - 1] = Self.Tok;
977       Self.PP.EnterTokenStream(Buffer, Toks.size(), true, /*Owned*/true);
978 
979       Self.Tok = Toks.front();
980     }
981   }
982 
983 private:
984   Parser &Self;
985   CachedTokens Toks;
986   tok::TokenKind EndKind;
987 };
988 
989 /// ConsumeAndStoreInitializer - Consume and store the token at the passed token
990 /// container until the end of the current initializer expression (either a
991 /// default argument or an in-class initializer for a non-static data member).
992 ///
993 /// Returns \c true if we reached the end of something initializer-shaped,
994 /// \c false if we bailed out.
ConsumeAndStoreInitializer(CachedTokens & Toks,CachedInitKind CIK)995 bool Parser::ConsumeAndStoreInitializer(CachedTokens &Toks,
996                                         CachedInitKind CIK) {
997   // We always want this function to consume at least one token if not at EOF.
998   bool IsFirstToken = true;
999 
1000   // Number of possible unclosed <s we've seen so far. These might be templates,
1001   // and might not, but if there were none of them (or we know for sure that
1002   // we're within a template), we can avoid a tentative parse.
1003   unsigned AngleCount = 0;
1004   unsigned KnownTemplateCount = 0;
1005 
1006   while (1) {
1007     switch (Tok.getKind()) {
1008     case tok::comma:
1009       // If we might be in a template, perform a tentative parse to check.
1010       if (!AngleCount)
1011         // Not a template argument: this is the end of the initializer.
1012         return true;
1013       if (KnownTemplateCount)
1014         goto consume_token;
1015 
1016       // We hit a comma inside angle brackets. This is the hard case. The
1017       // rule we follow is:
1018       //  * For a default argument, if the tokens after the comma form a
1019       //    syntactically-valid parameter-declaration-clause, in which each
1020       //    parameter has an initializer, then this comma ends the default
1021       //    argument.
1022       //  * For a default initializer, if the tokens after the comma form a
1023       //    syntactically-valid init-declarator-list, then this comma ends
1024       //    the default initializer.
1025       {
1026         UnannotatedTentativeParsingAction PA(*this,
1027                                              CIK == CIK_DefaultInitializer
1028                                                ? tok::semi : tok::r_paren);
1029         Sema::TentativeAnalysisScope Scope(Actions);
1030 
1031         TPResult Result = TPResult::Error;
1032         ConsumeToken();
1033         switch (CIK) {
1034         case CIK_DefaultInitializer:
1035           Result = TryParseInitDeclaratorList();
1036           // If we parsed a complete, ambiguous init-declarator-list, this
1037           // is only syntactically-valid if it's followed by a semicolon.
1038           if (Result == TPResult::Ambiguous && Tok.isNot(tok::semi))
1039             Result = TPResult::False;
1040           break;
1041 
1042         case CIK_DefaultArgument:
1043           bool InvalidAsDeclaration = false;
1044           Result = TryParseParameterDeclarationClause(
1045               &InvalidAsDeclaration, /*VersusTemplateArgument=*/true);
1046           // If this is an expression or a declaration with a missing
1047           // 'typename', assume it's not a declaration.
1048           if (Result == TPResult::Ambiguous && InvalidAsDeclaration)
1049             Result = TPResult::False;
1050           break;
1051         }
1052 
1053         // If what follows could be a declaration, it is a declaration.
1054         if (Result != TPResult::False && Result != TPResult::Error) {
1055           PA.Revert();
1056           return true;
1057         }
1058 
1059         // In the uncommon case that we decide the following tokens are part
1060         // of a template argument, revert any annotations we've performed in
1061         // those tokens. We're not going to look them up until we've parsed
1062         // the rest of the class, and that might add more declarations.
1063         PA.RevertAnnotations();
1064       }
1065 
1066       // Keep going. We know we're inside a template argument list now.
1067       ++KnownTemplateCount;
1068       goto consume_token;
1069 
1070     case tok::eof:
1071     case tok::annot_module_begin:
1072     case tok::annot_module_end:
1073     case tok::annot_module_include:
1074       // Ran out of tokens.
1075       return false;
1076 
1077     case tok::less:
1078       // FIXME: A '<' can only start a template-id if it's preceded by an
1079       // identifier, an operator-function-id, or a literal-operator-id.
1080       ++AngleCount;
1081       goto consume_token;
1082 
1083     case tok::question:
1084       // In 'a ? b : c', 'b' can contain an unparenthesized comma. If it does,
1085       // that is *never* the end of the initializer. Skip to the ':'.
1086       if (!ConsumeAndStoreConditional(Toks))
1087         return false;
1088       break;
1089 
1090     case tok::greatergreatergreater:
1091       if (!getLangOpts().CPlusPlus11)
1092         goto consume_token;
1093       if (AngleCount) --AngleCount;
1094       if (KnownTemplateCount) --KnownTemplateCount;
1095       // Fall through.
1096     case tok::greatergreater:
1097       if (!getLangOpts().CPlusPlus11)
1098         goto consume_token;
1099       if (AngleCount) --AngleCount;
1100       if (KnownTemplateCount) --KnownTemplateCount;
1101       // Fall through.
1102     case tok::greater:
1103       if (AngleCount) --AngleCount;
1104       if (KnownTemplateCount) --KnownTemplateCount;
1105       goto consume_token;
1106 
1107     case tok::kw_template:
1108       // 'template' identifier '<' is known to start a template argument list,
1109       // and can be used to disambiguate the parse.
1110       // FIXME: Support all forms of 'template' unqualified-id '<'.
1111       Toks.push_back(Tok);
1112       ConsumeToken();
1113       if (Tok.is(tok::identifier)) {
1114         Toks.push_back(Tok);
1115         ConsumeToken();
1116         if (Tok.is(tok::less)) {
1117           ++AngleCount;
1118           ++KnownTemplateCount;
1119           Toks.push_back(Tok);
1120           ConsumeToken();
1121         }
1122       }
1123       break;
1124 
1125     case tok::kw_operator:
1126       // If 'operator' precedes other punctuation, that punctuation loses
1127       // its special behavior.
1128       Toks.push_back(Tok);
1129       ConsumeToken();
1130       switch (Tok.getKind()) {
1131       case tok::comma:
1132       case tok::greatergreatergreater:
1133       case tok::greatergreater:
1134       case tok::greater:
1135       case tok::less:
1136         Toks.push_back(Tok);
1137         ConsumeToken();
1138         break;
1139       default:
1140         break;
1141       }
1142       break;
1143 
1144     case tok::l_paren:
1145       // Recursively consume properly-nested parens.
1146       Toks.push_back(Tok);
1147       ConsumeParen();
1148       ConsumeAndStoreUntil(tok::r_paren, Toks, /*StopAtSemi=*/false);
1149       break;
1150     case tok::l_square:
1151       // Recursively consume properly-nested square brackets.
1152       Toks.push_back(Tok);
1153       ConsumeBracket();
1154       ConsumeAndStoreUntil(tok::r_square, Toks, /*StopAtSemi=*/false);
1155       break;
1156     case tok::l_brace:
1157       // Recursively consume properly-nested braces.
1158       Toks.push_back(Tok);
1159       ConsumeBrace();
1160       ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
1161       break;
1162 
1163     // Okay, we found a ']' or '}' or ')', which we think should be balanced.
1164     // Since the user wasn't looking for this token (if they were, it would
1165     // already be handled), this isn't balanced.  If there is a LHS token at a
1166     // higher level, we will assume that this matches the unbalanced token
1167     // and return it.  Otherwise, this is a spurious RHS token, which we
1168     // consume and pass on to downstream code to diagnose.
1169     case tok::r_paren:
1170       if (CIK == CIK_DefaultArgument)
1171         return true; // End of the default argument.
1172       if (ParenCount && !IsFirstToken)
1173         return false;
1174       Toks.push_back(Tok);
1175       ConsumeParen();
1176       continue;
1177     case tok::r_square:
1178       if (BracketCount && !IsFirstToken)
1179         return false;
1180       Toks.push_back(Tok);
1181       ConsumeBracket();
1182       continue;
1183     case tok::r_brace:
1184       if (BraceCount && !IsFirstToken)
1185         return false;
1186       Toks.push_back(Tok);
1187       ConsumeBrace();
1188       continue;
1189 
1190     case tok::code_completion:
1191       Toks.push_back(Tok);
1192       ConsumeCodeCompletionToken();
1193       break;
1194 
1195     case tok::string_literal:
1196     case tok::wide_string_literal:
1197     case tok::utf8_string_literal:
1198     case tok::utf16_string_literal:
1199     case tok::utf32_string_literal:
1200       Toks.push_back(Tok);
1201       ConsumeStringToken();
1202       break;
1203     case tok::semi:
1204       if (CIK == CIK_DefaultInitializer)
1205         return true; // End of the default initializer.
1206       // FALL THROUGH.
1207     default:
1208     consume_token:
1209       Toks.push_back(Tok);
1210       ConsumeToken();
1211       break;
1212     }
1213     IsFirstToken = false;
1214   }
1215 }
1216