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,ExprResult & Init)25 NamedDecl *Parser::ParseCXXInlineMethodDef(AccessSpecifier AS,
26                                       AttributeList *AccessAttrs,
27                                       ParsingDeclarator &D,
28                                       const ParsedTemplateInfo &TemplateInfo,
29                                       const VirtSpecifiers& VS,
30                                       ExprResult& Init) {
31   assert(D.isFunctionDeclarator() && "This isn't a function declarator!");
32   assert((Tok.is(tok::l_brace) || Tok.is(tok::colon) || Tok.is(tok::kw_try) ||
33           Tok.is(tok::equal)) &&
34          "Current token not a '{', ':', '=', or 'try'!");
35 
36   MultiTemplateParamsArg TemplateParams(
37       TemplateInfo.TemplateParams ? TemplateInfo.TemplateParams->data()
38                                   : nullptr,
39       TemplateInfo.TemplateParams ? TemplateInfo.TemplateParams->size() : 0);
40 
41   NamedDecl *FnD;
42   if (D.getDeclSpec().isFriendSpecified())
43     FnD = Actions.ActOnFriendFunctionDecl(getCurScope(), D,
44                                           TemplateParams);
45   else {
46     FnD = Actions.ActOnCXXMemberDeclarator(getCurScope(), AS, D,
47                                            TemplateParams, nullptr,
48                                            VS, ICIS_NoInit);
49     if (FnD) {
50       Actions.ProcessDeclAttributeList(getCurScope(), FnD, AccessAttrs);
51       bool TypeSpecContainsAuto = D.getDeclSpec().containsPlaceholderType();
52       if (Init.isUsable())
53         Actions.AddInitializerToDecl(FnD, Init.get(), false,
54                                      TypeSpecContainsAuto);
55       else
56         Actions.ActOnUninitializedDecl(FnD, TypeSpecContainsAuto);
57     }
58   }
59 
60   HandleMemberFunctionDeclDelays(D, FnD);
61 
62   D.complete(FnD);
63 
64   if (TryConsumeToken(tok::equal)) {
65     if (!FnD) {
66       SkipUntil(tok::semi);
67       return nullptr;
68     }
69 
70     bool Delete = false;
71     SourceLocation KWLoc;
72     SourceLocation KWEndLoc = Tok.getEndLoc().getLocWithOffset(-1);
73     if (TryConsumeToken(tok::kw_delete, KWLoc)) {
74       Diag(KWLoc, getLangOpts().CPlusPlus11
75                       ? diag::warn_cxx98_compat_deleted_function
76                       : diag::ext_deleted_function);
77       Actions.SetDeclDeleted(FnD, KWLoc);
78       Delete = true;
79       if (auto *DeclAsFunction = dyn_cast<FunctionDecl>(FnD)) {
80         DeclAsFunction->setRangeEnd(KWEndLoc);
81       }
82     } else if (TryConsumeToken(tok::kw_default, KWLoc)) {
83       Diag(KWLoc, getLangOpts().CPlusPlus11
84                       ? diag::warn_cxx98_compat_defaulted_function
85                       : diag::ext_defaulted_function);
86       Actions.SetDeclDefaulted(FnD, KWLoc);
87       if (auto *DeclAsFunction = dyn_cast<FunctionDecl>(FnD)) {
88         DeclAsFunction->setRangeEnd(KWEndLoc);
89       }
90     } else {
91       llvm_unreachable("function definition after = not 'delete' or 'default'");
92     }
93 
94     if (Tok.is(tok::comma)) {
95       Diag(KWLoc, diag::err_default_delete_in_multiple_declaration)
96         << Delete;
97       SkipUntil(tok::semi);
98     } else if (ExpectAndConsume(tok::semi, diag::err_expected_after,
99                                 Delete ? "delete" : "default")) {
100       SkipUntil(tok::semi);
101     }
102 
103     return FnD;
104   }
105 
106   // In delayed template parsing mode, if we are within a class template
107   // or if we are about to parse function member template then consume
108   // the tokens and store them for parsing at the end of the translation unit.
109   if (getLangOpts().DelayedTemplateParsing &&
110       D.getFunctionDefinitionKind() == FDK_Definition &&
111       !D.getDeclSpec().isConstexprSpecified() &&
112       !(FnD && FnD->getAsFunction() &&
113         FnD->getAsFunction()->getReturnType()->getContainedAutoType()) &&
114       ((Actions.CurContext->isDependentContext() ||
115         (TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate &&
116          TemplateInfo.Kind != ParsedTemplateInfo::ExplicitSpecialization)) &&
117        !Actions.IsInsideALocalClassWithinATemplateFunction())) {
118 
119     CachedTokens Toks;
120     LexTemplateFunctionForLateParsing(Toks);
121 
122     if (FnD) {
123       FunctionDecl *FD = FnD->getAsFunction();
124       Actions.CheckForFunctionRedefinition(FD);
125       Actions.MarkAsLateParsedTemplate(FD, FnD, Toks);
126     }
127 
128     return FnD;
129   }
130 
131   // Consume the tokens and store them for later parsing.
132 
133   LexedMethod* LM = new LexedMethod(this, FnD);
134   getCurrentClass().LateParsedDeclarations.push_back(LM);
135   LM->TemplateScope = getCurScope()->isTemplateParamScope();
136   CachedTokens &Toks = LM->Toks;
137 
138   tok::TokenKind kind = Tok.getKind();
139   // Consume everything up to (and including) the left brace of the
140   // function body.
141   if (ConsumeAndStoreFunctionPrologue(Toks)) {
142     // We didn't find the left-brace we expected after the
143     // constructor initializer; we already printed an error, and it's likely
144     // impossible to recover, so don't try to parse this method later.
145     // Skip over the rest of the decl and back to somewhere that looks
146     // reasonable.
147     SkipMalformedDecl();
148     delete getCurrentClass().LateParsedDeclarations.back();
149     getCurrentClass().LateParsedDeclarations.pop_back();
150     return FnD;
151   } else {
152     // Consume everything up to (and including) the matching right brace.
153     ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
154   }
155 
156   // If we're in a function-try-block, we need to store all the catch blocks.
157   if (kind == tok::kw_try) {
158     while (Tok.is(tok::kw_catch)) {
159       ConsumeAndStoreUntil(tok::l_brace, Toks, /*StopAtSemi=*/false);
160       ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
161     }
162   }
163 
164   if (FnD) {
165     // If this is a friend function, mark that it's late-parsed so that
166     // it's still known to be a definition even before we attach the
167     // parsed body.  Sema needs to treat friend function definitions
168     // differently during template instantiation, and it's possible for
169     // the containing class to be instantiated before all its member
170     // function definitions are parsed.
171     //
172     // If you remove this, you can remove the code that clears the flag
173     // after parsing the member.
174     if (D.getDeclSpec().isFriendSpecified()) {
175       FunctionDecl *FD = FnD->getAsFunction();
176       Actions.CheckForFunctionRedefinition(FD);
177       FD->setLateTemplateParsed(true);
178     }
179   } else {
180     // If semantic analysis could not build a function declaration,
181     // just throw away the late-parsed declaration.
182     delete getCurrentClass().LateParsedDeclarations.back();
183     getCurrentClass().LateParsedDeclarations.pop_back();
184   }
185 
186   return FnD;
187 }
188 
189 /// ParseCXXNonStaticMemberInitializer - We parsed and verified that the
190 /// specified Declarator is a well formed C++ non-static data member
191 /// declaration. Now lex its initializer and store its tokens for parsing
192 /// after the class is complete.
ParseCXXNonStaticMemberInitializer(Decl * VarD)193 void Parser::ParseCXXNonStaticMemberInitializer(Decl *VarD) {
194   assert((Tok.is(tok::l_brace) || Tok.is(tok::equal)) &&
195          "Current token not a '{' or '='!");
196 
197   LateParsedMemberInitializer *MI =
198     new LateParsedMemberInitializer(this, VarD);
199   getCurrentClass().LateParsedDeclarations.push_back(MI);
200   CachedTokens &Toks = MI->Toks;
201 
202   tok::TokenKind kind = Tok.getKind();
203   if (kind == tok::equal) {
204     Toks.push_back(Tok);
205     ConsumeToken();
206   }
207 
208   if (kind == tok::l_brace) {
209     // Begin by storing the '{' token.
210     Toks.push_back(Tok);
211     ConsumeBrace();
212 
213     // Consume everything up to (and including) the matching right brace.
214     ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/true);
215   } else {
216     // Consume everything up to (but excluding) the comma or semicolon.
217     ConsumeAndStoreInitializer(Toks, CIK_DefaultInitializer);
218   }
219 
220   // Store an artificial EOF token to ensure that we don't run off the end of
221   // the initializer when we come to parse it.
222   Token Eof;
223   Eof.startToken();
224   Eof.setKind(tok::eof);
225   Eof.setLocation(Tok.getLocation());
226   Eof.setEofData(VarD);
227   Toks.push_back(Eof);
228 }
229 
~LateParsedDeclaration()230 Parser::LateParsedDeclaration::~LateParsedDeclaration() {}
ParseLexedMethodDeclarations()231 void Parser::LateParsedDeclaration::ParseLexedMethodDeclarations() {}
ParseLexedMemberInitializers()232 void Parser::LateParsedDeclaration::ParseLexedMemberInitializers() {}
ParseLexedMethodDefs()233 void Parser::LateParsedDeclaration::ParseLexedMethodDefs() {}
234 
LateParsedClass(Parser * P,ParsingClass * C)235 Parser::LateParsedClass::LateParsedClass(Parser *P, ParsingClass *C)
236   : Self(P), Class(C) {}
237 
~LateParsedClass()238 Parser::LateParsedClass::~LateParsedClass() {
239   Self->DeallocateParsedClasses(Class);
240 }
241 
ParseLexedMethodDeclarations()242 void Parser::LateParsedClass::ParseLexedMethodDeclarations() {
243   Self->ParseLexedMethodDeclarations(*Class);
244 }
245 
ParseLexedMemberInitializers()246 void Parser::LateParsedClass::ParseLexedMemberInitializers() {
247   Self->ParseLexedMemberInitializers(*Class);
248 }
249 
ParseLexedMethodDefs()250 void Parser::LateParsedClass::ParseLexedMethodDefs() {
251   Self->ParseLexedMethodDefs(*Class);
252 }
253 
ParseLexedMethodDeclarations()254 void Parser::LateParsedMethodDeclaration::ParseLexedMethodDeclarations() {
255   Self->ParseLexedMethodDeclaration(*this);
256 }
257 
ParseLexedMethodDefs()258 void Parser::LexedMethod::ParseLexedMethodDefs() {
259   Self->ParseLexedMethodDef(*this);
260 }
261 
ParseLexedMemberInitializers()262 void Parser::LateParsedMemberInitializer::ParseLexedMemberInitializers() {
263   Self->ParseLexedMemberInitializer(*this);
264 }
265 
266 /// ParseLexedMethodDeclarations - We finished parsing the member
267 /// specification of a top (non-nested) C++ class. Now go over the
268 /// stack of method declarations with some parts for which parsing was
269 /// delayed (such as default arguments) and parse them.
ParseLexedMethodDeclarations(ParsingClass & Class)270 void Parser::ParseLexedMethodDeclarations(ParsingClass &Class) {
271   bool HasTemplateScope = !Class.TopLevelClass && Class.TemplateScope;
272   ParseScope ClassTemplateScope(this, Scope::TemplateParamScope,
273                                 HasTemplateScope);
274   TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
275   if (HasTemplateScope) {
276     Actions.ActOnReenterTemplateScope(getCurScope(), Class.TagOrTemplate);
277     ++CurTemplateDepthTracker;
278   }
279 
280   // The current scope is still active if we're the top-level class.
281   // Otherwise we'll need to push and enter a new scope.
282   bool HasClassScope = !Class.TopLevelClass;
283   ParseScope ClassScope(this, Scope::ClassScope|Scope::DeclScope,
284                         HasClassScope);
285   if (HasClassScope)
286     Actions.ActOnStartDelayedMemberDeclarations(getCurScope(),
287                                                 Class.TagOrTemplate);
288 
289   for (size_t i = 0; i < Class.LateParsedDeclarations.size(); ++i) {
290     Class.LateParsedDeclarations[i]->ParseLexedMethodDeclarations();
291   }
292 
293   if (HasClassScope)
294     Actions.ActOnFinishDelayedMemberDeclarations(getCurScope(),
295                                                  Class.TagOrTemplate);
296 }
297 
ParseLexedMethodDeclaration(LateParsedMethodDeclaration & LM)298 void Parser::ParseLexedMethodDeclaration(LateParsedMethodDeclaration &LM) {
299   // If this is a member template, introduce the template parameter scope.
300   ParseScope TemplateScope(this, Scope::TemplateParamScope, LM.TemplateScope);
301   TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
302   if (LM.TemplateScope) {
303     Actions.ActOnReenterTemplateScope(getCurScope(), LM.Method);
304     ++CurTemplateDepthTracker;
305   }
306   // Start the delayed C++ method declaration
307   Actions.ActOnStartDelayedCXXMethodDeclaration(getCurScope(), LM.Method);
308 
309   // Introduce the parameters into scope and parse their default
310   // arguments.
311   ParseScope PrototypeScope(this, Scope::FunctionPrototypeScope |
312                             Scope::FunctionDeclarationScope | Scope::DeclScope);
313   for (unsigned I = 0, N = LM.DefaultArgs.size(); I != N; ++I) {
314     auto Param = cast<ParmVarDecl>(LM.DefaultArgs[I].Param);
315     // Introduce the parameter into scope.
316     bool HasUnparsed = Param->hasUnparsedDefaultArg();
317     Actions.ActOnDelayedCXXMethodParameter(getCurScope(), Param);
318     if (CachedTokens *Toks = LM.DefaultArgs[I].Toks) {
319       // Mark the end of the default argument so that we know when to stop when
320       // we parse it later on.
321       Token LastDefaultArgToken = Toks->back();
322       Token DefArgEnd;
323       DefArgEnd.startToken();
324       DefArgEnd.setKind(tok::eof);
325       DefArgEnd.setLocation(LastDefaultArgToken.getEndLoc());
326       DefArgEnd.setEofData(Param);
327       Toks->push_back(DefArgEnd);
328 
329       // Parse the default argument from its saved token stream.
330       Toks->push_back(Tok); // So that the current token doesn't get lost
331       PP.EnterTokenStream(&Toks->front(), Toks->size(), true, false);
332 
333       // Consume the previously-pushed token.
334       ConsumeAnyToken();
335 
336       // Consume the '='.
337       assert(Tok.is(tok::equal) && "Default argument not starting with '='");
338       SourceLocation EqualLoc = ConsumeToken();
339 
340       // The argument isn't actually potentially evaluated unless it is
341       // used.
342       EnterExpressionEvaluationContext Eval(Actions,
343                                             Sema::PotentiallyEvaluatedIfUsed,
344                                             Param);
345 
346       ExprResult DefArgResult;
347       if (getLangOpts().CPlusPlus11 && Tok.is(tok::l_brace)) {
348         Diag(Tok, diag::warn_cxx98_compat_generalized_initializer_lists);
349         DefArgResult = ParseBraceInitializer();
350       } else
351         DefArgResult = ParseAssignmentExpression();
352       DefArgResult = Actions.CorrectDelayedTyposInExpr(DefArgResult);
353       if (DefArgResult.isInvalid()) {
354         Actions.ActOnParamDefaultArgumentError(Param, EqualLoc);
355       } else {
356         if (Tok.isNot(tok::eof) || Tok.getEofData() != Param) {
357           // The last two tokens are the terminator and the saved value of
358           // Tok; the last token in the default argument is the one before
359           // those.
360           assert(Toks->size() >= 3 && "expected a token in default arg");
361           Diag(Tok.getLocation(), diag::err_default_arg_unparsed)
362             << SourceRange(Tok.getLocation(),
363                            (*Toks)[Toks->size() - 3].getLocation());
364         }
365         Actions.ActOnParamDefaultArgument(Param, EqualLoc,
366                                           DefArgResult.get());
367       }
368 
369       // There could be leftover tokens (e.g. because of an error).
370       // Skip through until we reach the 'end of default argument' token.
371       while (Tok.isNot(tok::eof))
372         ConsumeAnyToken();
373 
374       if (Tok.is(tok::eof) && Tok.getEofData() == Param)
375         ConsumeAnyToken();
376 
377       delete Toks;
378       LM.DefaultArgs[I].Toks = nullptr;
379     } else if (HasUnparsed) {
380       assert(Param->hasInheritedDefaultArg());
381       FunctionDecl *Old = cast<FunctionDecl>(LM.Method)->getPreviousDecl();
382       ParmVarDecl *OldParam = Old->getParamDecl(I);
383       assert (!OldParam->hasUnparsedDefaultArg());
384       if (OldParam->hasUninstantiatedDefaultArg())
385         Param->setUninstantiatedDefaultArg(
386                                       Param->getUninstantiatedDefaultArg());
387       else
388         Param->setDefaultArg(OldParam->getInit());
389     }
390   }
391 
392   // Parse a delayed exception-specification, if there is one.
393   if (CachedTokens *Toks = LM.ExceptionSpecTokens) {
394     // Add the 'stop' token.
395     Token LastExceptionSpecToken = Toks->back();
396     Token ExceptionSpecEnd;
397     ExceptionSpecEnd.startToken();
398     ExceptionSpecEnd.setKind(tok::eof);
399     ExceptionSpecEnd.setLocation(LastExceptionSpecToken.getEndLoc());
400     ExceptionSpecEnd.setEofData(LM.Method);
401     Toks->push_back(ExceptionSpecEnd);
402 
403     // Parse the default argument from its saved token stream.
404     Toks->push_back(Tok); // So that the current token doesn't get lost
405     PP.EnterTokenStream(&Toks->front(), Toks->size(), true, false);
406 
407     // Consume the previously-pushed token.
408     ConsumeAnyToken();
409 
410     // C++11 [expr.prim.general]p3:
411     //   If a declaration declares a member function or member function
412     //   template of a class X, the expression this is a prvalue of type
413     //   "pointer to cv-qualifier-seq X" between the optional cv-qualifer-seq
414     //   and the end of the function-definition, member-declarator, or
415     //   declarator.
416     CXXMethodDecl *Method;
417     if (FunctionTemplateDecl *FunTmpl
418           = dyn_cast<FunctionTemplateDecl>(LM.Method))
419       Method = cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
420     else
421       Method = cast<CXXMethodDecl>(LM.Method);
422 
423     Sema::CXXThisScopeRAII ThisScope(Actions, Method->getParent(),
424                                      Method->getTypeQualifiers(),
425                                      getLangOpts().CPlusPlus11);
426 
427     // Parse the exception-specification.
428     SourceRange SpecificationRange;
429     SmallVector<ParsedType, 4> DynamicExceptions;
430     SmallVector<SourceRange, 4> DynamicExceptionRanges;
431     ExprResult NoexceptExpr;
432     CachedTokens *ExceptionSpecTokens;
433 
434     ExceptionSpecificationType EST
435       = tryParseExceptionSpecification(/*Delayed=*/false, SpecificationRange,
436                                        DynamicExceptions,
437                                        DynamicExceptionRanges, NoexceptExpr,
438                                        ExceptionSpecTokens);
439 
440     if (Tok.isNot(tok::eof) || Tok.getEofData() != LM.Method)
441       Diag(Tok.getLocation(), diag::err_except_spec_unparsed);
442 
443     // Attach the exception-specification to the method.
444     Actions.actOnDelayedExceptionSpecification(LM.Method, EST,
445                                                SpecificationRange,
446                                                DynamicExceptions,
447                                                DynamicExceptionRanges,
448                                                NoexceptExpr.isUsable()?
449                                                  NoexceptExpr.get() : nullptr);
450 
451     // There could be leftover tokens (e.g. because of an error).
452     // Skip through until we reach the original token position.
453     while (Tok.isNot(tok::eof))
454       ConsumeAnyToken();
455 
456     // Clean up the remaining EOF token.
457     if (Tok.is(tok::eof) && Tok.getEofData() == LM.Method)
458       ConsumeAnyToken();
459 
460     delete Toks;
461     LM.ExceptionSpecTokens = nullptr;
462   }
463 
464   PrototypeScope.Exit();
465 
466   // Finish the delayed C++ method declaration.
467   Actions.ActOnFinishDelayedCXXMethodDeclaration(getCurScope(), LM.Method);
468 }
469 
470 /// ParseLexedMethodDefs - We finished parsing the member specification of a top
471 /// (non-nested) C++ class. Now go over the stack of lexed methods that were
472 /// collected during its parsing and parse them all.
ParseLexedMethodDefs(ParsingClass & Class)473 void Parser::ParseLexedMethodDefs(ParsingClass &Class) {
474   bool HasTemplateScope = !Class.TopLevelClass && Class.TemplateScope;
475   ParseScope ClassTemplateScope(this, Scope::TemplateParamScope, HasTemplateScope);
476   TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
477   if (HasTemplateScope) {
478     Actions.ActOnReenterTemplateScope(getCurScope(), Class.TagOrTemplate);
479     ++CurTemplateDepthTracker;
480   }
481   bool HasClassScope = !Class.TopLevelClass;
482   ParseScope ClassScope(this, Scope::ClassScope|Scope::DeclScope,
483                         HasClassScope);
484 
485   for (size_t i = 0; i < Class.LateParsedDeclarations.size(); ++i) {
486     Class.LateParsedDeclarations[i]->ParseLexedMethodDefs();
487   }
488 }
489 
ParseLexedMethodDef(LexedMethod & LM)490 void Parser::ParseLexedMethodDef(LexedMethod &LM) {
491   // If this is a member template, introduce the template parameter scope.
492   ParseScope TemplateScope(this, Scope::TemplateParamScope, LM.TemplateScope);
493   TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
494   if (LM.TemplateScope) {
495     Actions.ActOnReenterTemplateScope(getCurScope(), LM.D);
496     ++CurTemplateDepthTracker;
497   }
498 
499   assert(!LM.Toks.empty() && "Empty body!");
500   Token LastBodyToken = LM.Toks.back();
501   Token BodyEnd;
502   BodyEnd.startToken();
503   BodyEnd.setKind(tok::eof);
504   BodyEnd.setLocation(LastBodyToken.getEndLoc());
505   BodyEnd.setEofData(LM.D);
506   LM.Toks.push_back(BodyEnd);
507   // Append the current token at the end of the new token stream so that it
508   // doesn't get lost.
509   LM.Toks.push_back(Tok);
510   PP.EnterTokenStream(LM.Toks.data(), LM.Toks.size(), true, false);
511 
512   // Consume the previously pushed token.
513   ConsumeAnyToken(/*ConsumeCodeCompletionTok=*/true);
514   assert((Tok.is(tok::l_brace) || Tok.is(tok::colon) || Tok.is(tok::kw_try))
515          && "Inline method not starting with '{', ':' or 'try'");
516 
517   // Parse the method body. Function body parsing code is similar enough
518   // to be re-used for method bodies as well.
519   ParseScope FnScope(this, Scope::FnScope|Scope::DeclScope);
520   Actions.ActOnStartOfFunctionDef(getCurScope(), LM.D);
521 
522   if (Tok.is(tok::kw_try)) {
523     ParseFunctionTryBlock(LM.D, FnScope);
524 
525     while (Tok.isNot(tok::eof))
526       ConsumeAnyToken();
527 
528     if (Tok.is(tok::eof) && Tok.getEofData() == LM.D)
529       ConsumeAnyToken();
530     return;
531   }
532   if (Tok.is(tok::colon)) {
533     ParseConstructorInitializer(LM.D);
534 
535     // Error recovery.
536     if (!Tok.is(tok::l_brace)) {
537       FnScope.Exit();
538       Actions.ActOnFinishFunctionBody(LM.D, nullptr);
539 
540       while (Tok.isNot(tok::eof))
541         ConsumeAnyToken();
542 
543       if (Tok.is(tok::eof) && Tok.getEofData() == LM.D)
544         ConsumeAnyToken();
545       return;
546     }
547   } else
548     Actions.ActOnDefaultCtorInitializers(LM.D);
549 
550   assert((Actions.getDiagnostics().hasErrorOccurred() ||
551           !isa<FunctionTemplateDecl>(LM.D) ||
552           cast<FunctionTemplateDecl>(LM.D)->getTemplateParameters()->getDepth()
553             < TemplateParameterDepth) &&
554          "TemplateParameterDepth should be greater than the depth of "
555          "current template being instantiated!");
556 
557   ParseFunctionStatementBody(LM.D, FnScope);
558 
559   // Clear the late-template-parsed bit if we set it before.
560   if (LM.D)
561     LM.D->getAsFunction()->setLateTemplateParsed(false);
562 
563   while (Tok.isNot(tok::eof))
564     ConsumeAnyToken();
565 
566   if (Tok.is(tok::eof) && Tok.getEofData() == LM.D)
567     ConsumeAnyToken();
568 
569   if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(LM.D))
570     Actions.ActOnFinishInlineMethodDef(MD);
571 }
572 
573 /// ParseLexedMemberInitializers - We finished parsing the member specification
574 /// of a top (non-nested) C++ class. Now go over the stack of lexed data member
575 /// initializers that were collected during its parsing and parse them all.
ParseLexedMemberInitializers(ParsingClass & Class)576 void Parser::ParseLexedMemberInitializers(ParsingClass &Class) {
577   bool HasTemplateScope = !Class.TopLevelClass && Class.TemplateScope;
578   ParseScope ClassTemplateScope(this, Scope::TemplateParamScope,
579                                 HasTemplateScope);
580   TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
581   if (HasTemplateScope) {
582     Actions.ActOnReenterTemplateScope(getCurScope(), Class.TagOrTemplate);
583     ++CurTemplateDepthTracker;
584   }
585   // Set or update the scope flags.
586   bool AlreadyHasClassScope = Class.TopLevelClass;
587   unsigned ScopeFlags = Scope::ClassScope|Scope::DeclScope;
588   ParseScope ClassScope(this, ScopeFlags, !AlreadyHasClassScope);
589   ParseScopeFlags ClassScopeFlags(this, ScopeFlags, AlreadyHasClassScope);
590 
591   if (!AlreadyHasClassScope)
592     Actions.ActOnStartDelayedMemberDeclarations(getCurScope(),
593                                                 Class.TagOrTemplate);
594 
595   if (!Class.LateParsedDeclarations.empty()) {
596     // C++11 [expr.prim.general]p4:
597     //   Otherwise, if a member-declarator declares a non-static data member
598     //  (9.2) of a class X, the expression this is a prvalue of type "pointer
599     //  to X" within the optional brace-or-equal-initializer. It shall not
600     //  appear elsewhere in the member-declarator.
601     Sema::CXXThisScopeRAII ThisScope(Actions, Class.TagOrTemplate,
602                                      /*TypeQuals=*/(unsigned)0);
603 
604     for (size_t i = 0; i < Class.LateParsedDeclarations.size(); ++i) {
605       Class.LateParsedDeclarations[i]->ParseLexedMemberInitializers();
606     }
607   }
608 
609   if (!AlreadyHasClassScope)
610     Actions.ActOnFinishDelayedMemberDeclarations(getCurScope(),
611                                                  Class.TagOrTemplate);
612 
613   Actions.ActOnFinishDelayedMemberInitializers(Class.TagOrTemplate);
614 }
615 
ParseLexedMemberInitializer(LateParsedMemberInitializer & MI)616 void Parser::ParseLexedMemberInitializer(LateParsedMemberInitializer &MI) {
617   if (!MI.Field || MI.Field->isInvalidDecl())
618     return;
619 
620   // Append the current token at the end of the new token stream so that it
621   // doesn't get lost.
622   MI.Toks.push_back(Tok);
623   PP.EnterTokenStream(MI.Toks.data(), MI.Toks.size(), true, false);
624 
625   // Consume the previously pushed token.
626   ConsumeAnyToken(/*ConsumeCodeCompletionTok=*/true);
627 
628   SourceLocation EqualLoc;
629 
630   Actions.ActOnStartCXXInClassMemberInitializer();
631 
632   ExprResult Init = ParseCXXMemberInitializer(MI.Field, /*IsFunction=*/false,
633                                               EqualLoc);
634 
635   Actions.ActOnFinishCXXInClassMemberInitializer(MI.Field, EqualLoc,
636                                                  Init.get());
637 
638   // The next token should be our artificial terminating EOF token.
639   if (Tok.isNot(tok::eof)) {
640     if (!Init.isInvalid()) {
641       SourceLocation EndLoc = PP.getLocForEndOfToken(PrevTokLocation);
642       if (!EndLoc.isValid())
643         EndLoc = Tok.getLocation();
644       // No fixit; we can't recover as if there were a semicolon here.
645       Diag(EndLoc, diag::err_expected_semi_decl_list);
646     }
647 
648     // Consume tokens until we hit the artificial EOF.
649     while (Tok.isNot(tok::eof))
650       ConsumeAnyToken();
651   }
652   // Make sure this is *our* artificial EOF token.
653   if (Tok.getEofData() == MI.Field)
654     ConsumeAnyToken();
655 }
656 
657 /// ConsumeAndStoreUntil - Consume and store the token at the passed token
658 /// container until the token 'T' is reached (which gets
659 /// consumed/stored too, if ConsumeFinalToken).
660 /// If StopAtSemi is true, then we will stop early at a ';' character.
661 /// Returns true if token 'T1' or 'T2' was found.
662 /// NOTE: This is a specialized version of Parser::SkipUntil.
ConsumeAndStoreUntil(tok::TokenKind T1,tok::TokenKind T2,CachedTokens & Toks,bool StopAtSemi,bool ConsumeFinalToken)663 bool Parser::ConsumeAndStoreUntil(tok::TokenKind T1, tok::TokenKind T2,
664                                   CachedTokens &Toks,
665                                   bool StopAtSemi, bool ConsumeFinalToken) {
666   // We always want this function to consume at least one token if the first
667   // token isn't T and if not at EOF.
668   bool isFirstTokenConsumed = true;
669   while (1) {
670     // If we found one of the tokens, stop and return true.
671     if (Tok.is(T1) || Tok.is(T2)) {
672       if (ConsumeFinalToken) {
673         Toks.push_back(Tok);
674         ConsumeAnyToken();
675       }
676       return true;
677     }
678 
679     switch (Tok.getKind()) {
680     case tok::eof:
681     case tok::annot_module_begin:
682     case tok::annot_module_end:
683     case tok::annot_module_include:
684       // Ran out of tokens.
685       return false;
686 
687     case tok::l_paren:
688       // Recursively consume properly-nested parens.
689       Toks.push_back(Tok);
690       ConsumeParen();
691       ConsumeAndStoreUntil(tok::r_paren, Toks, /*StopAtSemi=*/false);
692       break;
693     case tok::l_square:
694       // Recursively consume properly-nested square brackets.
695       Toks.push_back(Tok);
696       ConsumeBracket();
697       ConsumeAndStoreUntil(tok::r_square, Toks, /*StopAtSemi=*/false);
698       break;
699     case tok::l_brace:
700       // Recursively consume properly-nested braces.
701       Toks.push_back(Tok);
702       ConsumeBrace();
703       ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
704       break;
705 
706     // Okay, we found a ']' or '}' or ')', which we think should be balanced.
707     // Since the user wasn't looking for this token (if they were, it would
708     // already be handled), this isn't balanced.  If there is a LHS token at a
709     // higher level, we will assume that this matches the unbalanced token
710     // and return it.  Otherwise, this is a spurious RHS token, which we skip.
711     case tok::r_paren:
712       if (ParenCount && !isFirstTokenConsumed)
713         return false;  // Matches something.
714       Toks.push_back(Tok);
715       ConsumeParen();
716       break;
717     case tok::r_square:
718       if (BracketCount && !isFirstTokenConsumed)
719         return false;  // Matches something.
720       Toks.push_back(Tok);
721       ConsumeBracket();
722       break;
723     case tok::r_brace:
724       if (BraceCount && !isFirstTokenConsumed)
725         return false;  // Matches something.
726       Toks.push_back(Tok);
727       ConsumeBrace();
728       break;
729 
730     case tok::code_completion:
731       Toks.push_back(Tok);
732       ConsumeCodeCompletionToken();
733       break;
734 
735     case tok::string_literal:
736     case tok::wide_string_literal:
737     case tok::utf8_string_literal:
738     case tok::utf16_string_literal:
739     case tok::utf32_string_literal:
740       Toks.push_back(Tok);
741       ConsumeStringToken();
742       break;
743     case tok::semi:
744       if (StopAtSemi)
745         return false;
746       // FALL THROUGH.
747     default:
748       // consume this token.
749       Toks.push_back(Tok);
750       ConsumeToken();
751       break;
752     }
753     isFirstTokenConsumed = false;
754   }
755 }
756 
757 /// \brief Consume tokens and store them in the passed token container until
758 /// we've passed the try keyword and constructor initializers and have consumed
759 /// the opening brace of the function body. The opening brace will be consumed
760 /// if and only if there was no error.
761 ///
762 /// \return True on error.
ConsumeAndStoreFunctionPrologue(CachedTokens & Toks)763 bool Parser::ConsumeAndStoreFunctionPrologue(CachedTokens &Toks) {
764   if (Tok.is(tok::kw_try)) {
765     Toks.push_back(Tok);
766     ConsumeToken();
767   }
768 
769   if (Tok.isNot(tok::colon)) {
770     // Easy case, just a function body.
771 
772     // Grab any remaining garbage to be diagnosed later. We stop when we reach a
773     // brace: an opening one is the function body, while a closing one probably
774     // means we've reached the end of the class.
775     ConsumeAndStoreUntil(tok::l_brace, tok::r_brace, Toks,
776                          /*StopAtSemi=*/true,
777                          /*ConsumeFinalToken=*/false);
778     if (Tok.isNot(tok::l_brace))
779       return Diag(Tok.getLocation(), diag::err_expected) << tok::l_brace;
780 
781     Toks.push_back(Tok);
782     ConsumeBrace();
783     return false;
784   }
785 
786   Toks.push_back(Tok);
787   ConsumeToken();
788 
789   // We can't reliably skip over a mem-initializer-id, because it could be
790   // a template-id involving not-yet-declared names. Given:
791   //
792   //   S ( ) : a < b < c > ( e )
793   //
794   // 'e' might be an initializer or part of a template argument, depending
795   // on whether 'b' is a template.
796 
797   // Track whether we might be inside a template argument. We can give
798   // significantly better diagnostics if we know that we're not.
799   bool MightBeTemplateArgument = false;
800 
801   while (true) {
802     // Skip over the mem-initializer-id, if possible.
803     if (Tok.is(tok::kw_decltype)) {
804       Toks.push_back(Tok);
805       SourceLocation OpenLoc = ConsumeToken();
806       if (Tok.isNot(tok::l_paren))
807         return Diag(Tok.getLocation(), diag::err_expected_lparen_after)
808                  << "decltype";
809       Toks.push_back(Tok);
810       ConsumeParen();
811       if (!ConsumeAndStoreUntil(tok::r_paren, Toks, /*StopAtSemi=*/true)) {
812         Diag(Tok.getLocation(), diag::err_expected) << tok::r_paren;
813         Diag(OpenLoc, diag::note_matching) << tok::l_paren;
814         return true;
815       }
816     }
817     do {
818       // Walk over a component of a nested-name-specifier.
819       if (Tok.is(tok::coloncolon)) {
820         Toks.push_back(Tok);
821         ConsumeToken();
822 
823         if (Tok.is(tok::kw_template)) {
824           Toks.push_back(Tok);
825           ConsumeToken();
826         }
827       }
828 
829       if (Tok.is(tok::identifier) || Tok.is(tok::kw_template)) {
830         Toks.push_back(Tok);
831         ConsumeToken();
832       } else if (Tok.is(tok::code_completion)) {
833         Toks.push_back(Tok);
834         ConsumeCodeCompletionToken();
835         // Consume the rest of the initializers permissively.
836         // FIXME: We should be able to perform code-completion here even if
837         //        there isn't a subsequent '{' token.
838         MightBeTemplateArgument = true;
839         break;
840       } else {
841         break;
842       }
843     } while (Tok.is(tok::coloncolon));
844 
845     if (Tok.is(tok::less))
846       MightBeTemplateArgument = true;
847 
848     if (MightBeTemplateArgument) {
849       // We may be inside a template argument list. Grab up to the start of the
850       // next parenthesized initializer or braced-init-list. This *might* be the
851       // initializer, or it might be a subexpression in the template argument
852       // list.
853       // FIXME: Count angle brackets, and clear MightBeTemplateArgument
854       //        if all angles are closed.
855       if (!ConsumeAndStoreUntil(tok::l_paren, tok::l_brace, Toks,
856                                 /*StopAtSemi=*/true,
857                                 /*ConsumeFinalToken=*/false)) {
858         // We're not just missing the initializer, we're also missing the
859         // function body!
860         return Diag(Tok.getLocation(), diag::err_expected) << tok::l_brace;
861       }
862     } else if (Tok.isNot(tok::l_paren) && Tok.isNot(tok::l_brace)) {
863       // We found something weird in a mem-initializer-id.
864       if (getLangOpts().CPlusPlus11)
865         return Diag(Tok.getLocation(), diag::err_expected_either)
866                << tok::l_paren << tok::l_brace;
867       else
868         return Diag(Tok.getLocation(), diag::err_expected) << tok::l_paren;
869     }
870 
871     tok::TokenKind kind = Tok.getKind();
872     Toks.push_back(Tok);
873     bool IsLParen = (kind == tok::l_paren);
874     SourceLocation OpenLoc = Tok.getLocation();
875 
876     if (IsLParen) {
877       ConsumeParen();
878     } else {
879       assert(kind == tok::l_brace && "Must be left paren or brace here.");
880       ConsumeBrace();
881       // In C++03, this has to be the start of the function body, which
882       // means the initializer is malformed; we'll diagnose it later.
883       if (!getLangOpts().CPlusPlus11)
884         return false;
885     }
886 
887     // Grab the initializer (or the subexpression of the template argument).
888     // FIXME: If we support lambdas here, we'll need to set StopAtSemi to false
889     //        if we might be inside the braces of a lambda-expression.
890     tok::TokenKind CloseKind = IsLParen ? tok::r_paren : tok::r_brace;
891     if (!ConsumeAndStoreUntil(CloseKind, Toks, /*StopAtSemi=*/true)) {
892       Diag(Tok, diag::err_expected) << CloseKind;
893       Diag(OpenLoc, diag::note_matching) << kind;
894       return true;
895     }
896 
897     // Grab pack ellipsis, if present.
898     if (Tok.is(tok::ellipsis)) {
899       Toks.push_back(Tok);
900       ConsumeToken();
901     }
902 
903     // If we know we just consumed a mem-initializer, we must have ',' or '{'
904     // next.
905     if (Tok.is(tok::comma)) {
906       Toks.push_back(Tok);
907       ConsumeToken();
908     } else if (Tok.is(tok::l_brace)) {
909       // This is the function body if the ')' or '}' is immediately followed by
910       // a '{'. That cannot happen within a template argument, apart from the
911       // case where a template argument contains a compound literal:
912       //
913       //   S ( ) : a < b < c > ( d ) { }
914       //   // End of declaration, or still inside the template argument?
915       //
916       // ... and the case where the template argument contains a lambda:
917       //
918       //   S ( ) : a < 0 && b < c > ( d ) + [ ] ( ) { return 0; }
919       //     ( ) > ( ) { }
920       //
921       // FIXME: Disambiguate these cases. Note that the latter case is probably
922       //        going to be made ill-formed by core issue 1607.
923       Toks.push_back(Tok);
924       ConsumeBrace();
925       return false;
926     } else if (!MightBeTemplateArgument) {
927       return Diag(Tok.getLocation(), diag::err_expected_either) << tok::l_brace
928                                                                 << tok::comma;
929     }
930   }
931 }
932 
933 /// \brief Consume and store tokens from the '?' to the ':' in a conditional
934 /// expression.
ConsumeAndStoreConditional(CachedTokens & Toks)935 bool Parser::ConsumeAndStoreConditional(CachedTokens &Toks) {
936   // Consume '?'.
937   assert(Tok.is(tok::question));
938   Toks.push_back(Tok);
939   ConsumeToken();
940 
941   while (Tok.isNot(tok::colon)) {
942     if (!ConsumeAndStoreUntil(tok::question, tok::colon, Toks,
943                               /*StopAtSemi=*/true,
944                               /*ConsumeFinalToken=*/false))
945       return false;
946 
947     // If we found a nested conditional, consume it.
948     if (Tok.is(tok::question) && !ConsumeAndStoreConditional(Toks))
949       return false;
950   }
951 
952   // Consume ':'.
953   Toks.push_back(Tok);
954   ConsumeToken();
955   return true;
956 }
957 
958 /// \brief A tentative parsing action that can also revert token annotations.
959 class Parser::UnannotatedTentativeParsingAction : public TentativeParsingAction {
960 public:
UnannotatedTentativeParsingAction(Parser & Self,tok::TokenKind EndKind)961   explicit UnannotatedTentativeParsingAction(Parser &Self,
962                                              tok::TokenKind EndKind)
963       : TentativeParsingAction(Self), Self(Self), EndKind(EndKind) {
964     // Stash away the old token stream, so we can restore it once the
965     // tentative parse is complete.
966     TentativeParsingAction Inner(Self);
967     Self.ConsumeAndStoreUntil(EndKind, Toks, true, /*ConsumeFinalToken*/false);
968     Inner.Revert();
969   }
970 
RevertAnnotations()971   void RevertAnnotations() {
972     Revert();
973 
974     // Put back the original tokens.
975     Self.SkipUntil(EndKind, StopAtSemi | StopBeforeMatch);
976     if (Toks.size()) {
977       Token *Buffer = new Token[Toks.size()];
978       std::copy(Toks.begin() + 1, Toks.end(), Buffer);
979       Buffer[Toks.size() - 1] = Self.Tok;
980       Self.PP.EnterTokenStream(Buffer, Toks.size(), true, /*Owned*/true);
981 
982       Self.Tok = Toks.front();
983     }
984   }
985 
986 private:
987   Parser &Self;
988   CachedTokens Toks;
989   tok::TokenKind EndKind;
990 };
991 
992 /// ConsumeAndStoreInitializer - Consume and store the token at the passed token
993 /// container until the end of the current initializer expression (either a
994 /// default argument or an in-class initializer for a non-static data member).
995 ///
996 /// Returns \c true if we reached the end of something initializer-shaped,
997 /// \c false if we bailed out.
ConsumeAndStoreInitializer(CachedTokens & Toks,CachedInitKind CIK)998 bool Parser::ConsumeAndStoreInitializer(CachedTokens &Toks,
999                                         CachedInitKind CIK) {
1000   // We always want this function to consume at least one token if not at EOF.
1001   bool IsFirstToken = true;
1002 
1003   // Number of possible unclosed <s we've seen so far. These might be templates,
1004   // and might not, but if there were none of them (or we know for sure that
1005   // we're within a template), we can avoid a tentative parse.
1006   unsigned AngleCount = 0;
1007   unsigned KnownTemplateCount = 0;
1008 
1009   while (1) {
1010     switch (Tok.getKind()) {
1011     case tok::comma:
1012       // If we might be in a template, perform a tentative parse to check.
1013       if (!AngleCount)
1014         // Not a template argument: this is the end of the initializer.
1015         return true;
1016       if (KnownTemplateCount)
1017         goto consume_token;
1018 
1019       // We hit a comma inside angle brackets. This is the hard case. The
1020       // rule we follow is:
1021       //  * For a default argument, if the tokens after the comma form a
1022       //    syntactically-valid parameter-declaration-clause, in which each
1023       //    parameter has an initializer, then this comma ends the default
1024       //    argument.
1025       //  * For a default initializer, if the tokens after the comma form a
1026       //    syntactically-valid init-declarator-list, then this comma ends
1027       //    the default initializer.
1028       {
1029         UnannotatedTentativeParsingAction PA(*this,
1030                                              CIK == CIK_DefaultInitializer
1031                                                ? tok::semi : tok::r_paren);
1032         Sema::TentativeAnalysisScope Scope(Actions);
1033 
1034         TPResult Result = TPResult::Error;
1035         ConsumeToken();
1036         switch (CIK) {
1037         case CIK_DefaultInitializer:
1038           Result = TryParseInitDeclaratorList();
1039           // If we parsed a complete, ambiguous init-declarator-list, this
1040           // is only syntactically-valid if it's followed by a semicolon.
1041           if (Result == TPResult::Ambiguous && Tok.isNot(tok::semi))
1042             Result = TPResult::False;
1043           break;
1044 
1045         case CIK_DefaultArgument:
1046           bool InvalidAsDeclaration = false;
1047           Result = TryParseParameterDeclarationClause(
1048               &InvalidAsDeclaration, /*VersusTemplateArgument=*/true);
1049           // If this is an expression or a declaration with a missing
1050           // 'typename', assume it's not a declaration.
1051           if (Result == TPResult::Ambiguous && InvalidAsDeclaration)
1052             Result = TPResult::False;
1053           break;
1054         }
1055 
1056         // If what follows could be a declaration, it is a declaration.
1057         if (Result != TPResult::False && Result != TPResult::Error) {
1058           PA.Revert();
1059           return true;
1060         }
1061 
1062         // In the uncommon case that we decide the following tokens are part
1063         // of a template argument, revert any annotations we've performed in
1064         // those tokens. We're not going to look them up until we've parsed
1065         // the rest of the class, and that might add more declarations.
1066         PA.RevertAnnotations();
1067       }
1068 
1069       // Keep going. We know we're inside a template argument list now.
1070       ++KnownTemplateCount;
1071       goto consume_token;
1072 
1073     case tok::eof:
1074     case tok::annot_module_begin:
1075     case tok::annot_module_end:
1076     case tok::annot_module_include:
1077       // Ran out of tokens.
1078       return false;
1079 
1080     case tok::less:
1081       // FIXME: A '<' can only start a template-id if it's preceded by an
1082       // identifier, an operator-function-id, or a literal-operator-id.
1083       ++AngleCount;
1084       goto consume_token;
1085 
1086     case tok::question:
1087       // In 'a ? b : c', 'b' can contain an unparenthesized comma. If it does,
1088       // that is *never* the end of the initializer. Skip to the ':'.
1089       if (!ConsumeAndStoreConditional(Toks))
1090         return false;
1091       break;
1092 
1093     case tok::greatergreatergreater:
1094       if (!getLangOpts().CPlusPlus11)
1095         goto consume_token;
1096       if (AngleCount) --AngleCount;
1097       if (KnownTemplateCount) --KnownTemplateCount;
1098       // Fall through.
1099     case tok::greatergreater:
1100       if (!getLangOpts().CPlusPlus11)
1101         goto consume_token;
1102       if (AngleCount) --AngleCount;
1103       if (KnownTemplateCount) --KnownTemplateCount;
1104       // Fall through.
1105     case tok::greater:
1106       if (AngleCount) --AngleCount;
1107       if (KnownTemplateCount) --KnownTemplateCount;
1108       goto consume_token;
1109 
1110     case tok::kw_template:
1111       // 'template' identifier '<' is known to start a template argument list,
1112       // and can be used to disambiguate the parse.
1113       // FIXME: Support all forms of 'template' unqualified-id '<'.
1114       Toks.push_back(Tok);
1115       ConsumeToken();
1116       if (Tok.is(tok::identifier)) {
1117         Toks.push_back(Tok);
1118         ConsumeToken();
1119         if (Tok.is(tok::less)) {
1120           ++AngleCount;
1121           ++KnownTemplateCount;
1122           Toks.push_back(Tok);
1123           ConsumeToken();
1124         }
1125       }
1126       break;
1127 
1128     case tok::kw_operator:
1129       // If 'operator' precedes other punctuation, that punctuation loses
1130       // its special behavior.
1131       Toks.push_back(Tok);
1132       ConsumeToken();
1133       switch (Tok.getKind()) {
1134       case tok::comma:
1135       case tok::greatergreatergreater:
1136       case tok::greatergreater:
1137       case tok::greater:
1138       case tok::less:
1139         Toks.push_back(Tok);
1140         ConsumeToken();
1141         break;
1142       default:
1143         break;
1144       }
1145       break;
1146 
1147     case tok::l_paren:
1148       // Recursively consume properly-nested parens.
1149       Toks.push_back(Tok);
1150       ConsumeParen();
1151       ConsumeAndStoreUntil(tok::r_paren, Toks, /*StopAtSemi=*/false);
1152       break;
1153     case tok::l_square:
1154       // Recursively consume properly-nested square brackets.
1155       Toks.push_back(Tok);
1156       ConsumeBracket();
1157       ConsumeAndStoreUntil(tok::r_square, Toks, /*StopAtSemi=*/false);
1158       break;
1159     case tok::l_brace:
1160       // Recursively consume properly-nested braces.
1161       Toks.push_back(Tok);
1162       ConsumeBrace();
1163       ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false);
1164       break;
1165 
1166     // Okay, we found a ']' or '}' or ')', which we think should be balanced.
1167     // Since the user wasn't looking for this token (if they were, it would
1168     // already be handled), this isn't balanced.  If there is a LHS token at a
1169     // higher level, we will assume that this matches the unbalanced token
1170     // and return it.  Otherwise, this is a spurious RHS token, which we
1171     // consume and pass on to downstream code to diagnose.
1172     case tok::r_paren:
1173       if (CIK == CIK_DefaultArgument)
1174         return true; // End of the default argument.
1175       if (ParenCount && !IsFirstToken)
1176         return false;
1177       Toks.push_back(Tok);
1178       ConsumeParen();
1179       continue;
1180     case tok::r_square:
1181       if (BracketCount && !IsFirstToken)
1182         return false;
1183       Toks.push_back(Tok);
1184       ConsumeBracket();
1185       continue;
1186     case tok::r_brace:
1187       if (BraceCount && !IsFirstToken)
1188         return false;
1189       Toks.push_back(Tok);
1190       ConsumeBrace();
1191       continue;
1192 
1193     case tok::code_completion:
1194       Toks.push_back(Tok);
1195       ConsumeCodeCompletionToken();
1196       break;
1197 
1198     case tok::string_literal:
1199     case tok::wide_string_literal:
1200     case tok::utf8_string_literal:
1201     case tok::utf16_string_literal:
1202     case tok::utf32_string_literal:
1203       Toks.push_back(Tok);
1204       ConsumeStringToken();
1205       break;
1206     case tok::semi:
1207       if (CIK == CIK_DefaultInitializer)
1208         return true; // End of the default initializer.
1209       // FALL THROUGH.
1210     default:
1211     consume_token:
1212       Toks.push_back(Tok);
1213       ConsumeToken();
1214       break;
1215     }
1216     IsFirstToken = false;
1217   }
1218 }
1219