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1 //===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
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 //  This file implements C++ template instantiation for declarations.
10 //
11 //===----------------------------------------------------------------------===/
12 #include "clang/Sema/SemaInternal.h"
13 #include "clang/Sema/Lookup.h"
14 #include "clang/Sema/PrettyDeclStackTrace.h"
15 #include "clang/Sema/Template.h"
16 #include "clang/AST/ASTConsumer.h"
17 #include "clang/AST/ASTContext.h"
18 #include "clang/AST/DeclTemplate.h"
19 #include "clang/AST/DeclVisitor.h"
20 #include "clang/AST/DependentDiagnostic.h"
21 #include "clang/AST/Expr.h"
22 #include "clang/AST/ExprCXX.h"
23 #include "clang/AST/TypeLoc.h"
24 #include "clang/Lex/Preprocessor.h"
25 
26 using namespace clang;
27 
SubstQualifier(const DeclaratorDecl * OldDecl,DeclaratorDecl * NewDecl)28 bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
29                                               DeclaratorDecl *NewDecl) {
30   if (!OldDecl->getQualifierLoc())
31     return false;
32 
33   NestedNameSpecifierLoc NewQualifierLoc
34     = SemaRef.SubstNestedNameSpecifierLoc(OldDecl->getQualifierLoc(),
35                                           TemplateArgs);
36 
37   if (!NewQualifierLoc)
38     return true;
39 
40   NewDecl->setQualifierInfo(NewQualifierLoc);
41   return false;
42 }
43 
SubstQualifier(const TagDecl * OldDecl,TagDecl * NewDecl)44 bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
45                                               TagDecl *NewDecl) {
46   if (!OldDecl->getQualifierLoc())
47     return false;
48 
49   NestedNameSpecifierLoc NewQualifierLoc
50   = SemaRef.SubstNestedNameSpecifierLoc(OldDecl->getQualifierLoc(),
51                                         TemplateArgs);
52 
53   if (!NewQualifierLoc)
54     return true;
55 
56   NewDecl->setQualifierInfo(NewQualifierLoc);
57   return false;
58 }
59 
60 // FIXME: Is this still too simple?
InstantiateAttrs(const MultiLevelTemplateArgumentList & TemplateArgs,const Decl * Tmpl,Decl * New)61 void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
62                             const Decl *Tmpl, Decl *New) {
63   for (AttrVec::const_iterator i = Tmpl->attr_begin(), e = Tmpl->attr_end();
64        i != e; ++i) {
65     const Attr *TmplAttr = *i;
66     // FIXME: This should be generalized to more than just the AlignedAttr.
67     if (const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr)) {
68       if (Aligned->isAlignmentDependent()) {
69         // The alignment expression is not potentially evaluated.
70         EnterExpressionEvaluationContext Unevaluated(*this,
71                                                      Sema::Unevaluated);
72 
73         if (Aligned->isAlignmentExpr()) {
74           ExprResult Result = SubstExpr(Aligned->getAlignmentExpr(),
75                                         TemplateArgs);
76           if (!Result.isInvalid())
77             AddAlignedAttr(Aligned->getLocation(), New, Result.takeAs<Expr>());
78         }
79         else {
80           TypeSourceInfo *Result = SubstType(Aligned->getAlignmentType(),
81                                              TemplateArgs,
82                                              Aligned->getLocation(),
83                                              DeclarationName());
84           if (Result)
85             AddAlignedAttr(Aligned->getLocation(), New, Result);
86         }
87         continue;
88       }
89     }
90 
91     // FIXME: Is cloning correct for all attributes?
92     Attr *NewAttr = TmplAttr->clone(Context);
93     New->addAttr(NewAttr);
94   }
95 }
96 
97 Decl *
VisitTranslationUnitDecl(TranslationUnitDecl * D)98 TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
99   assert(false && "Translation units cannot be instantiated");
100   return D;
101 }
102 
103 Decl *
VisitLabelDecl(LabelDecl * D)104 TemplateDeclInstantiator::VisitLabelDecl(LabelDecl *D) {
105   LabelDecl *Inst = LabelDecl::Create(SemaRef.Context, Owner, D->getLocation(),
106                                       D->getIdentifier());
107   Owner->addDecl(Inst);
108   return Inst;
109 }
110 
111 Decl *
VisitNamespaceDecl(NamespaceDecl * D)112 TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
113   assert(false && "Namespaces cannot be instantiated");
114   return D;
115 }
116 
117 Decl *
VisitNamespaceAliasDecl(NamespaceAliasDecl * D)118 TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
119   NamespaceAliasDecl *Inst
120     = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
121                                  D->getNamespaceLoc(),
122                                  D->getAliasLoc(),
123                                  D->getIdentifier(),
124                                  D->getQualifierLoc(),
125                                  D->getTargetNameLoc(),
126                                  D->getNamespace());
127   Owner->addDecl(Inst);
128   return Inst;
129 }
130 
InstantiateTypedefNameDecl(TypedefNameDecl * D,bool IsTypeAlias)131 Decl *TemplateDeclInstantiator::InstantiateTypedefNameDecl(TypedefNameDecl *D,
132                                                            bool IsTypeAlias) {
133   bool Invalid = false;
134   TypeSourceInfo *DI = D->getTypeSourceInfo();
135   if (DI->getType()->isInstantiationDependentType() ||
136       DI->getType()->isVariablyModifiedType()) {
137     DI = SemaRef.SubstType(DI, TemplateArgs,
138                            D->getLocation(), D->getDeclName());
139     if (!DI) {
140       Invalid = true;
141       DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
142     }
143   } else {
144     SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
145   }
146 
147   // Create the new typedef
148   TypedefNameDecl *Typedef;
149   if (IsTypeAlias)
150     Typedef = TypeAliasDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
151                                     D->getLocation(), D->getIdentifier(), DI);
152   else
153     Typedef = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
154                                   D->getLocation(), D->getIdentifier(), DI);
155   if (Invalid)
156     Typedef->setInvalidDecl();
157 
158   // If the old typedef was the name for linkage purposes of an anonymous
159   // tag decl, re-establish that relationship for the new typedef.
160   if (const TagType *oldTagType = D->getUnderlyingType()->getAs<TagType>()) {
161     TagDecl *oldTag = oldTagType->getDecl();
162     if (oldTag->getTypedefNameForAnonDecl() == D) {
163       TagDecl *newTag = DI->getType()->castAs<TagType>()->getDecl();
164       assert(!newTag->getIdentifier() && !newTag->getTypedefNameForAnonDecl());
165       newTag->setTypedefNameForAnonDecl(Typedef);
166     }
167   }
168 
169   if (TypedefNameDecl *Prev = D->getPreviousDeclaration()) {
170     NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
171                                                        TemplateArgs);
172     if (!InstPrev)
173       return 0;
174 
175     Typedef->setPreviousDeclaration(cast<TypedefNameDecl>(InstPrev));
176   }
177 
178   SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef);
179 
180   Typedef->setAccess(D->getAccess());
181 
182   return Typedef;
183 }
184 
VisitTypedefDecl(TypedefDecl * D)185 Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
186   Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/false);
187   Owner->addDecl(Typedef);
188   return Typedef;
189 }
190 
VisitTypeAliasDecl(TypeAliasDecl * D)191 Decl *TemplateDeclInstantiator::VisitTypeAliasDecl(TypeAliasDecl *D) {
192   Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/true);
193   Owner->addDecl(Typedef);
194   return Typedef;
195 }
196 
197 Decl *
VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl * D)198 TemplateDeclInstantiator::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
199   // Create a local instantiation scope for this type alias template, which
200   // will contain the instantiations of the template parameters.
201   LocalInstantiationScope Scope(SemaRef);
202 
203   TemplateParameterList *TempParams = D->getTemplateParameters();
204   TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
205   if (!InstParams)
206     return 0;
207 
208   TypeAliasDecl *Pattern = D->getTemplatedDecl();
209 
210   TypeAliasTemplateDecl *PrevAliasTemplate = 0;
211   if (Pattern->getPreviousDeclaration()) {
212     DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
213     if (Found.first != Found.second) {
214       PrevAliasTemplate = dyn_cast<TypeAliasTemplateDecl>(*Found.first);
215     }
216   }
217 
218   TypeAliasDecl *AliasInst = cast_or_null<TypeAliasDecl>(
219     InstantiateTypedefNameDecl(Pattern, /*IsTypeAlias=*/true));
220   if (!AliasInst)
221     return 0;
222 
223   TypeAliasTemplateDecl *Inst
224     = TypeAliasTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
225                                     D->getDeclName(), InstParams, AliasInst);
226   if (PrevAliasTemplate)
227     Inst->setPreviousDeclaration(PrevAliasTemplate);
228 
229   Inst->setAccess(D->getAccess());
230 
231   if (!PrevAliasTemplate)
232     Inst->setInstantiatedFromMemberTemplate(D);
233 
234   Owner->addDecl(Inst);
235 
236   return Inst;
237 }
238 
239 /// \brief Instantiate an initializer, breaking it into separate
240 /// initialization arguments.
241 ///
242 /// \param Init The initializer to instantiate.
243 ///
244 /// \param TemplateArgs Template arguments to be substituted into the
245 /// initializer.
246 ///
247 /// \param NewArgs Will be filled in with the instantiation arguments.
248 ///
249 /// \returns true if an error occurred, false otherwise
InstantiateInitializer(Expr * Init,const MultiLevelTemplateArgumentList & TemplateArgs,SourceLocation & LParenLoc,ASTOwningVector<Expr * > & NewArgs,SourceLocation & RParenLoc)250 bool Sema::InstantiateInitializer(Expr *Init,
251                             const MultiLevelTemplateArgumentList &TemplateArgs,
252                                   SourceLocation &LParenLoc,
253                                   ASTOwningVector<Expr*> &NewArgs,
254                                   SourceLocation &RParenLoc) {
255   NewArgs.clear();
256   LParenLoc = SourceLocation();
257   RParenLoc = SourceLocation();
258 
259   if (!Init)
260     return false;
261 
262   if (ExprWithCleanups *ExprTemp = dyn_cast<ExprWithCleanups>(Init))
263     Init = ExprTemp->getSubExpr();
264 
265   while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init))
266     Init = Binder->getSubExpr();
267 
268   if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
269     Init = ICE->getSubExprAsWritten();
270 
271   if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
272     LParenLoc = ParenList->getLParenLoc();
273     RParenLoc = ParenList->getRParenLoc();
274     return SubstExprs(ParenList->getExprs(), ParenList->getNumExprs(),
275                       true, TemplateArgs, NewArgs);
276   }
277 
278   if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) {
279     if (!isa<CXXTemporaryObjectExpr>(Construct)) {
280       if (SubstExprs(Construct->getArgs(), Construct->getNumArgs(), true,
281                      TemplateArgs, NewArgs))
282         return true;
283 
284       // FIXME: Fake locations!
285       LParenLoc = PP.getLocForEndOfToken(Init->getLocStart());
286       RParenLoc = LParenLoc;
287       return false;
288     }
289   }
290 
291   ExprResult Result = SubstExpr(Init, TemplateArgs);
292   if (Result.isInvalid())
293     return true;
294 
295   NewArgs.push_back(Result.takeAs<Expr>());
296   return false;
297 }
298 
VisitVarDecl(VarDecl * D)299 Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
300   // If this is the variable for an anonymous struct or union,
301   // instantiate the anonymous struct/union type first.
302   if (const RecordType *RecordTy = D->getType()->getAs<RecordType>())
303     if (RecordTy->getDecl()->isAnonymousStructOrUnion())
304       if (!VisitCXXRecordDecl(cast<CXXRecordDecl>(RecordTy->getDecl())))
305         return 0;
306 
307   // Do substitution on the type of the declaration
308   TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
309                                          TemplateArgs,
310                                          D->getTypeSpecStartLoc(),
311                                          D->getDeclName());
312   if (!DI)
313     return 0;
314 
315   if (DI->getType()->isFunctionType()) {
316     SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
317       << D->isStaticDataMember() << DI->getType();
318     return 0;
319   }
320 
321   // Build the instantiated declaration
322   VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
323                                  D->getInnerLocStart(),
324                                  D->getLocation(), D->getIdentifier(),
325                                  DI->getType(), DI,
326                                  D->getStorageClass(),
327                                  D->getStorageClassAsWritten());
328   Var->setThreadSpecified(D->isThreadSpecified());
329   Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
330   Var->setCXXForRangeDecl(D->isCXXForRangeDecl());
331 
332   // Substitute the nested name specifier, if any.
333   if (SubstQualifier(D, Var))
334     return 0;
335 
336   // If we are instantiating a static data member defined
337   // out-of-line, the instantiation will have the same lexical
338   // context (which will be a namespace scope) as the template.
339   if (D->isOutOfLine())
340     Var->setLexicalDeclContext(D->getLexicalDeclContext());
341 
342   Var->setAccess(D->getAccess());
343 
344   if (!D->isStaticDataMember()) {
345     Var->setUsed(D->isUsed(false));
346     Var->setReferenced(D->isReferenced());
347   }
348 
349   // FIXME: In theory, we could have a previous declaration for variables that
350   // are not static data members.
351   bool Redeclaration = false;
352   // FIXME: having to fake up a LookupResult is dumb.
353   LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
354                         Sema::LookupOrdinaryName, Sema::ForRedeclaration);
355   if (D->isStaticDataMember())
356     SemaRef.LookupQualifiedName(Previous, Owner, false);
357   SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
358 
359   if (D->isOutOfLine()) {
360     if (!D->isStaticDataMember())
361       D->getLexicalDeclContext()->addDecl(Var);
362     Owner->makeDeclVisibleInContext(Var);
363   } else {
364     Owner->addDecl(Var);
365     if (Owner->isFunctionOrMethod())
366       SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Var);
367   }
368   SemaRef.InstantiateAttrs(TemplateArgs, D, Var);
369 
370   // Link instantiations of static data members back to the template from
371   // which they were instantiated.
372   if (Var->isStaticDataMember())
373     SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
374                                                      TSK_ImplicitInstantiation);
375 
376   if (Var->getAnyInitializer()) {
377     // We already have an initializer in the class.
378   } else if (D->getInit()) {
379     if (Var->isStaticDataMember() && !D->isOutOfLine())
380       SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
381     else
382       SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
383 
384     // Instantiate the initializer.
385     SourceLocation LParenLoc, RParenLoc;
386     ASTOwningVector<Expr*> InitArgs(SemaRef);
387     if (!SemaRef.InstantiateInitializer(D->getInit(), TemplateArgs, LParenLoc,
388                                         InitArgs, RParenLoc)) {
389       bool TypeMayContainAuto = true;
390       // Attach the initializer to the declaration, if we have one.
391       if (InitArgs.size() == 0)
392         SemaRef.ActOnUninitializedDecl(Var, TypeMayContainAuto);
393       else if (D->hasCXXDirectInitializer()) {
394         // Add the direct initializer to the declaration.
395         SemaRef.AddCXXDirectInitializerToDecl(Var,
396                                               LParenLoc,
397                                               move_arg(InitArgs),
398                                               RParenLoc,
399                                               TypeMayContainAuto);
400       } else {
401         assert(InitArgs.size() == 1);
402         Expr *Init = InitArgs.take()[0];
403         SemaRef.AddInitializerToDecl(Var, Init, false, TypeMayContainAuto);
404       }
405     } else {
406       // FIXME: Not too happy about invalidating the declaration
407       // because of a bogus initializer.
408       Var->setInvalidDecl();
409     }
410 
411     SemaRef.PopExpressionEvaluationContext();
412   } else if ((!Var->isStaticDataMember() || Var->isOutOfLine()) &&
413              !Var->isCXXForRangeDecl())
414     SemaRef.ActOnUninitializedDecl(Var, false);
415 
416   // Diagnose unused local variables with dependent types, where the diagnostic
417   // will have been deferred.
418   if (!Var->isInvalidDecl() && Owner->isFunctionOrMethod() && !Var->isUsed() &&
419       D->getType()->isDependentType())
420     SemaRef.DiagnoseUnusedDecl(Var);
421 
422   return Var;
423 }
424 
VisitAccessSpecDecl(AccessSpecDecl * D)425 Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
426   AccessSpecDecl* AD
427     = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
428                              D->getAccessSpecifierLoc(), D->getColonLoc());
429   Owner->addHiddenDecl(AD);
430   return AD;
431 }
432 
VisitFieldDecl(FieldDecl * D)433 Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
434   bool Invalid = false;
435   TypeSourceInfo *DI = D->getTypeSourceInfo();
436   if (DI->getType()->isInstantiationDependentType() ||
437       DI->getType()->isVariablyModifiedType())  {
438     DI = SemaRef.SubstType(DI, TemplateArgs,
439                            D->getLocation(), D->getDeclName());
440     if (!DI) {
441       DI = D->getTypeSourceInfo();
442       Invalid = true;
443     } else if (DI->getType()->isFunctionType()) {
444       // C++ [temp.arg.type]p3:
445       //   If a declaration acquires a function type through a type
446       //   dependent on a template-parameter and this causes a
447       //   declaration that does not use the syntactic form of a
448       //   function declarator to have function type, the program is
449       //   ill-formed.
450       SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
451         << DI->getType();
452       Invalid = true;
453     }
454   } else {
455     SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
456   }
457 
458   Expr *BitWidth = D->getBitWidth();
459   if (Invalid)
460     BitWidth = 0;
461   else if (BitWidth) {
462     // The bit-width expression is not potentially evaluated.
463     EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
464 
465     ExprResult InstantiatedBitWidth
466       = SemaRef.SubstExpr(BitWidth, TemplateArgs);
467     if (InstantiatedBitWidth.isInvalid()) {
468       Invalid = true;
469       BitWidth = 0;
470     } else
471       BitWidth = InstantiatedBitWidth.takeAs<Expr>();
472   }
473 
474   FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
475                                             DI->getType(), DI,
476                                             cast<RecordDecl>(Owner),
477                                             D->getLocation(),
478                                             D->isMutable(),
479                                             BitWidth,
480                                             D->hasInClassInitializer(),
481                                             D->getTypeSpecStartLoc(),
482                                             D->getAccess(),
483                                             0);
484   if (!Field) {
485     cast<Decl>(Owner)->setInvalidDecl();
486     return 0;
487   }
488 
489   SemaRef.InstantiateAttrs(TemplateArgs, D, Field);
490 
491   if (Invalid)
492     Field->setInvalidDecl();
493 
494   if (!Field->getDeclName()) {
495     // Keep track of where this decl came from.
496     SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
497   }
498   if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
499     if (Parent->isAnonymousStructOrUnion() &&
500         Parent->getRedeclContext()->isFunctionOrMethod())
501       SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
502   }
503 
504   Field->setImplicit(D->isImplicit());
505   Field->setAccess(D->getAccess());
506   Owner->addDecl(Field);
507 
508   return Field;
509 }
510 
VisitIndirectFieldDecl(IndirectFieldDecl * D)511 Decl *TemplateDeclInstantiator::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
512   NamedDecl **NamedChain =
513     new (SemaRef.Context)NamedDecl*[D->getChainingSize()];
514 
515   int i = 0;
516   for (IndirectFieldDecl::chain_iterator PI =
517        D->chain_begin(), PE = D->chain_end();
518        PI != PE; ++PI) {
519     NamedDecl *Next = SemaRef.FindInstantiatedDecl(D->getLocation(), *PI,
520                                               TemplateArgs);
521     if (!Next)
522       return 0;
523 
524     NamedChain[i++] = Next;
525   }
526 
527   QualType T = cast<FieldDecl>(NamedChain[i-1])->getType();
528   IndirectFieldDecl* IndirectField
529     = IndirectFieldDecl::Create(SemaRef.Context, Owner, D->getLocation(),
530                                 D->getIdentifier(), T,
531                                 NamedChain, D->getChainingSize());
532 
533 
534   IndirectField->setImplicit(D->isImplicit());
535   IndirectField->setAccess(D->getAccess());
536   Owner->addDecl(IndirectField);
537   return IndirectField;
538 }
539 
VisitFriendDecl(FriendDecl * D)540 Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
541   // Handle friend type expressions by simply substituting template
542   // parameters into the pattern type and checking the result.
543   if (TypeSourceInfo *Ty = D->getFriendType()) {
544     TypeSourceInfo *InstTy;
545     // If this is an unsupported friend, don't bother substituting template
546     // arguments into it. The actual type referred to won't be used by any
547     // parts of Clang, and may not be valid for instantiating. Just use the
548     // same info for the instantiated friend.
549     if (D->isUnsupportedFriend()) {
550       InstTy = Ty;
551     } else {
552       InstTy = SemaRef.SubstType(Ty, TemplateArgs,
553                                  D->getLocation(), DeclarationName());
554     }
555     if (!InstTy)
556       return 0;
557 
558     FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getFriendLoc(), InstTy);
559     if (!FD)
560       return 0;
561 
562     FD->setAccess(AS_public);
563     FD->setUnsupportedFriend(D->isUnsupportedFriend());
564     Owner->addDecl(FD);
565     return FD;
566   }
567 
568   NamedDecl *ND = D->getFriendDecl();
569   assert(ND && "friend decl must be a decl or a type!");
570 
571   // All of the Visit implementations for the various potential friend
572   // declarations have to be carefully written to work for friend
573   // objects, with the most important detail being that the target
574   // decl should almost certainly not be placed in Owner.
575   Decl *NewND = Visit(ND);
576   if (!NewND) return 0;
577 
578   FriendDecl *FD =
579     FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
580                        cast<NamedDecl>(NewND), D->getFriendLoc());
581   FD->setAccess(AS_public);
582   FD->setUnsupportedFriend(D->isUnsupportedFriend());
583   Owner->addDecl(FD);
584   return FD;
585 }
586 
VisitStaticAssertDecl(StaticAssertDecl * D)587 Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
588   Expr *AssertExpr = D->getAssertExpr();
589 
590   // The expression in a static assertion is not potentially evaluated.
591   EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
592 
593   ExprResult InstantiatedAssertExpr
594     = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
595   if (InstantiatedAssertExpr.isInvalid())
596     return 0;
597 
598   ExprResult Message(D->getMessage());
599   D->getMessage();
600   return SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
601                                               InstantiatedAssertExpr.get(),
602                                               Message.get(),
603                                               D->getRParenLoc());
604 }
605 
VisitEnumDecl(EnumDecl * D)606 Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
607   EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
608                                     D->getLocation(), D->getIdentifier(),
609                                     /*PrevDecl=*/0, D->isScoped(),
610                                     D->isScopedUsingClassTag(), D->isFixed());
611   if (D->isFixed()) {
612     if (TypeSourceInfo* TI = D->getIntegerTypeSourceInfo()) {
613       // If we have type source information for the underlying type, it means it
614       // has been explicitly set by the user. Perform substitution on it before
615       // moving on.
616       SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
617       Enum->setIntegerTypeSourceInfo(SemaRef.SubstType(TI,
618                                                        TemplateArgs,
619                                                        UnderlyingLoc,
620                                                        DeclarationName()));
621 
622       if (!Enum->getIntegerTypeSourceInfo())
623         Enum->setIntegerType(SemaRef.Context.IntTy);
624     }
625     else {
626       assert(!D->getIntegerType()->isDependentType()
627              && "Dependent type without type source info");
628       Enum->setIntegerType(D->getIntegerType());
629     }
630   }
631 
632   SemaRef.InstantiateAttrs(TemplateArgs, D, Enum);
633 
634   Enum->setInstantiationOfMemberEnum(D);
635   Enum->setAccess(D->getAccess());
636   if (SubstQualifier(D, Enum)) return 0;
637   Owner->addDecl(Enum);
638   Enum->startDefinition();
639 
640   if (D->getDeclContext()->isFunctionOrMethod())
641     SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
642 
643   llvm::SmallVector<Decl*, 4> Enumerators;
644 
645   EnumConstantDecl *LastEnumConst = 0;
646   for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
647          ECEnd = D->enumerator_end();
648        EC != ECEnd; ++EC) {
649     // The specified value for the enumerator.
650     ExprResult Value = SemaRef.Owned((Expr *)0);
651     if (Expr *UninstValue = EC->getInitExpr()) {
652       // The enumerator's value expression is not potentially evaluated.
653       EnterExpressionEvaluationContext Unevaluated(SemaRef,
654                                                    Sema::Unevaluated);
655 
656       Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
657     }
658 
659     // Drop the initial value and continue.
660     bool isInvalid = false;
661     if (Value.isInvalid()) {
662       Value = SemaRef.Owned((Expr *)0);
663       isInvalid = true;
664     }
665 
666     EnumConstantDecl *EnumConst
667       = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
668                                   EC->getLocation(), EC->getIdentifier(),
669                                   Value.get());
670 
671     if (isInvalid) {
672       if (EnumConst)
673         EnumConst->setInvalidDecl();
674       Enum->setInvalidDecl();
675     }
676 
677     if (EnumConst) {
678       SemaRef.InstantiateAttrs(TemplateArgs, *EC, EnumConst);
679 
680       EnumConst->setAccess(Enum->getAccess());
681       Enum->addDecl(EnumConst);
682       Enumerators.push_back(EnumConst);
683       LastEnumConst = EnumConst;
684 
685       if (D->getDeclContext()->isFunctionOrMethod()) {
686         // If the enumeration is within a function or method, record the enum
687         // constant as a local.
688         SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
689       }
690     }
691   }
692 
693   // FIXME: Fixup LBraceLoc and RBraceLoc
694   // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
695   SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
696                         Enum,
697                         Enumerators.data(), Enumerators.size(),
698                         0, 0);
699 
700   return Enum;
701 }
702 
VisitEnumConstantDecl(EnumConstantDecl * D)703 Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
704   assert(false && "EnumConstantDecls can only occur within EnumDecls.");
705   return 0;
706 }
707 
VisitClassTemplateDecl(ClassTemplateDecl * D)708 Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
709   bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
710 
711   // Create a local instantiation scope for this class template, which
712   // will contain the instantiations of the template parameters.
713   LocalInstantiationScope Scope(SemaRef);
714   TemplateParameterList *TempParams = D->getTemplateParameters();
715   TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
716   if (!InstParams)
717     return NULL;
718 
719   CXXRecordDecl *Pattern = D->getTemplatedDecl();
720 
721   // Instantiate the qualifier.  We have to do this first in case
722   // we're a friend declaration, because if we are then we need to put
723   // the new declaration in the appropriate context.
724   NestedNameSpecifierLoc QualifierLoc = Pattern->getQualifierLoc();
725   if (QualifierLoc) {
726     QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
727                                                        TemplateArgs);
728     if (!QualifierLoc)
729       return 0;
730   }
731 
732   CXXRecordDecl *PrevDecl = 0;
733   ClassTemplateDecl *PrevClassTemplate = 0;
734 
735   if (!isFriend && Pattern->getPreviousDeclaration()) {
736     DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
737     if (Found.first != Found.second) {
738       PrevClassTemplate = dyn_cast<ClassTemplateDecl>(*Found.first);
739       if (PrevClassTemplate)
740         PrevDecl = PrevClassTemplate->getTemplatedDecl();
741     }
742   }
743 
744   // If this isn't a friend, then it's a member template, in which
745   // case we just want to build the instantiation in the
746   // specialization.  If it is a friend, we want to build it in
747   // the appropriate context.
748   DeclContext *DC = Owner;
749   if (isFriend) {
750     if (QualifierLoc) {
751       CXXScopeSpec SS;
752       SS.Adopt(QualifierLoc);
753       DC = SemaRef.computeDeclContext(SS);
754       if (!DC) return 0;
755     } else {
756       DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
757                                            Pattern->getDeclContext(),
758                                            TemplateArgs);
759     }
760 
761     // Look for a previous declaration of the template in the owning
762     // context.
763     LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
764                    Sema::LookupOrdinaryName, Sema::ForRedeclaration);
765     SemaRef.LookupQualifiedName(R, DC);
766 
767     if (R.isSingleResult()) {
768       PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
769       if (PrevClassTemplate)
770         PrevDecl = PrevClassTemplate->getTemplatedDecl();
771     }
772 
773     if (!PrevClassTemplate && QualifierLoc) {
774       SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
775         << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
776         << QualifierLoc.getSourceRange();
777       return 0;
778     }
779 
780     bool AdoptedPreviousTemplateParams = false;
781     if (PrevClassTemplate) {
782       bool Complain = true;
783 
784       // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
785       // template for struct std::tr1::__detail::_Map_base, where the
786       // template parameters of the friend declaration don't match the
787       // template parameters of the original declaration. In this one
788       // case, we don't complain about the ill-formed friend
789       // declaration.
790       if (isFriend && Pattern->getIdentifier() &&
791           Pattern->getIdentifier()->isStr("_Map_base") &&
792           DC->isNamespace() &&
793           cast<NamespaceDecl>(DC)->getIdentifier() &&
794           cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
795         DeclContext *DCParent = DC->getParent();
796         if (DCParent->isNamespace() &&
797             cast<NamespaceDecl>(DCParent)->getIdentifier() &&
798             cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
799           DeclContext *DCParent2 = DCParent->getParent();
800           if (DCParent2->isNamespace() &&
801               cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
802               cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
803               DCParent2->getParent()->isTranslationUnit())
804             Complain = false;
805         }
806       }
807 
808       TemplateParameterList *PrevParams
809         = PrevClassTemplate->getTemplateParameters();
810 
811       // Make sure the parameter lists match.
812       if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
813                                                   Complain,
814                                                   Sema::TPL_TemplateMatch)) {
815         if (Complain)
816           return 0;
817 
818         AdoptedPreviousTemplateParams = true;
819         InstParams = PrevParams;
820       }
821 
822       // Do some additional validation, then merge default arguments
823       // from the existing declarations.
824       if (!AdoptedPreviousTemplateParams &&
825           SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
826                                              Sema::TPC_ClassTemplate))
827         return 0;
828     }
829   }
830 
831   CXXRecordDecl *RecordInst
832     = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
833                             Pattern->getLocStart(), Pattern->getLocation(),
834                             Pattern->getIdentifier(), PrevDecl,
835                             /*DelayTypeCreation=*/true);
836 
837   if (QualifierLoc)
838     RecordInst->setQualifierInfo(QualifierLoc);
839 
840   ClassTemplateDecl *Inst
841     = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
842                                 D->getIdentifier(), InstParams, RecordInst,
843                                 PrevClassTemplate);
844   RecordInst->setDescribedClassTemplate(Inst);
845 
846   if (isFriend) {
847     if (PrevClassTemplate)
848       Inst->setAccess(PrevClassTemplate->getAccess());
849     else
850       Inst->setAccess(D->getAccess());
851 
852     Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
853     // TODO: do we want to track the instantiation progeny of this
854     // friend target decl?
855   } else {
856     Inst->setAccess(D->getAccess());
857     if (!PrevClassTemplate)
858       Inst->setInstantiatedFromMemberTemplate(D);
859   }
860 
861   // Trigger creation of the type for the instantiation.
862   SemaRef.Context.getInjectedClassNameType(RecordInst,
863                                     Inst->getInjectedClassNameSpecialization());
864 
865   // Finish handling of friends.
866   if (isFriend) {
867     DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
868     return Inst;
869   }
870 
871   Owner->addDecl(Inst);
872 
873   if (!PrevClassTemplate) {
874     // Queue up any out-of-line partial specializations of this member
875     // class template; the client will force their instantiation once
876     // the enclosing class has been instantiated.
877     llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
878     D->getPartialSpecializations(PartialSpecs);
879     for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
880       if (PartialSpecs[I]->isOutOfLine())
881         OutOfLinePartialSpecs.push_back(std::make_pair(Inst, PartialSpecs[I]));
882   }
883 
884   return Inst;
885 }
886 
887 Decl *
VisitClassTemplatePartialSpecializationDecl(ClassTemplatePartialSpecializationDecl * D)888 TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
889                                    ClassTemplatePartialSpecializationDecl *D) {
890   ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
891 
892   // Lookup the already-instantiated declaration in the instantiation
893   // of the class template and return that.
894   DeclContext::lookup_result Found
895     = Owner->lookup(ClassTemplate->getDeclName());
896   if (Found.first == Found.second)
897     return 0;
898 
899   ClassTemplateDecl *InstClassTemplate
900     = dyn_cast<ClassTemplateDecl>(*Found.first);
901   if (!InstClassTemplate)
902     return 0;
903 
904   if (ClassTemplatePartialSpecializationDecl *Result
905         = InstClassTemplate->findPartialSpecInstantiatedFromMember(D))
906     return Result;
907 
908   return InstantiateClassTemplatePartialSpecialization(InstClassTemplate, D);
909 }
910 
911 Decl *
VisitFunctionTemplateDecl(FunctionTemplateDecl * D)912 TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
913   // Create a local instantiation scope for this function template, which
914   // will contain the instantiations of the template parameters and then get
915   // merged with the local instantiation scope for the function template
916   // itself.
917   LocalInstantiationScope Scope(SemaRef);
918 
919   TemplateParameterList *TempParams = D->getTemplateParameters();
920   TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
921   if (!InstParams)
922     return NULL;
923 
924   FunctionDecl *Instantiated = 0;
925   if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
926     Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
927                                                                  InstParams));
928   else
929     Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
930                                                           D->getTemplatedDecl(),
931                                                                 InstParams));
932 
933   if (!Instantiated)
934     return 0;
935 
936   Instantiated->setAccess(D->getAccess());
937 
938   // Link the instantiated function template declaration to the function
939   // template from which it was instantiated.
940   FunctionTemplateDecl *InstTemplate
941     = Instantiated->getDescribedFunctionTemplate();
942   InstTemplate->setAccess(D->getAccess());
943   assert(InstTemplate &&
944          "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
945 
946   bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
947 
948   // Link the instantiation back to the pattern *unless* this is a
949   // non-definition friend declaration.
950   if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
951       !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
952     InstTemplate->setInstantiatedFromMemberTemplate(D);
953 
954   // Make declarations visible in the appropriate context.
955   if (!isFriend)
956     Owner->addDecl(InstTemplate);
957 
958   return InstTemplate;
959 }
960 
VisitCXXRecordDecl(CXXRecordDecl * D)961 Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
962   CXXRecordDecl *PrevDecl = 0;
963   if (D->isInjectedClassName())
964     PrevDecl = cast<CXXRecordDecl>(Owner);
965   else if (D->getPreviousDeclaration()) {
966     NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
967                                                    D->getPreviousDeclaration(),
968                                                    TemplateArgs);
969     if (!Prev) return 0;
970     PrevDecl = cast<CXXRecordDecl>(Prev);
971   }
972 
973   CXXRecordDecl *Record
974     = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
975                             D->getLocStart(), D->getLocation(),
976                             D->getIdentifier(), PrevDecl);
977 
978   // Substitute the nested name specifier, if any.
979   if (SubstQualifier(D, Record))
980     return 0;
981 
982   Record->setImplicit(D->isImplicit());
983   // FIXME: Check against AS_none is an ugly hack to work around the issue that
984   // the tag decls introduced by friend class declarations don't have an access
985   // specifier. Remove once this area of the code gets sorted out.
986   if (D->getAccess() != AS_none)
987     Record->setAccess(D->getAccess());
988   if (!D->isInjectedClassName())
989     Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
990 
991   // If the original function was part of a friend declaration,
992   // inherit its namespace state.
993   if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
994     Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
995 
996   // Make sure that anonymous structs and unions are recorded.
997   if (D->isAnonymousStructOrUnion()) {
998     Record->setAnonymousStructOrUnion(true);
999     if (Record->getDeclContext()->getRedeclContext()->isFunctionOrMethod())
1000       SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
1001   }
1002 
1003   Owner->addDecl(Record);
1004   return Record;
1005 }
1006 
1007 /// Normal class members are of more specific types and therefore
1008 /// don't make it here.  This function serves two purposes:
1009 ///   1) instantiating function templates
1010 ///   2) substituting friend declarations
1011 /// FIXME: preserve function definitions in case #2
VisitFunctionDecl(FunctionDecl * D,TemplateParameterList * TemplateParams)1012 Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
1013                                        TemplateParameterList *TemplateParams) {
1014   // Check whether there is already a function template specialization for
1015   // this declaration.
1016   FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1017   void *InsertPos = 0;
1018   if (FunctionTemplate && !TemplateParams) {
1019     std::pair<const TemplateArgument *, unsigned> Innermost
1020       = TemplateArgs.getInnermost();
1021 
1022     FunctionDecl *SpecFunc
1023       = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
1024                                              InsertPos);
1025 
1026     // If we already have a function template specialization, return it.
1027     if (SpecFunc)
1028       return SpecFunc;
1029   }
1030 
1031   bool isFriend;
1032   if (FunctionTemplate)
1033     isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1034   else
1035     isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1036 
1037   bool MergeWithParentScope = (TemplateParams != 0) ||
1038     Owner->isFunctionOrMethod() ||
1039     !(isa<Decl>(Owner) &&
1040       cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1041   LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1042 
1043   llvm::SmallVector<ParmVarDecl *, 4> Params;
1044   TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1045   TInfo = SubstFunctionType(D, Params);
1046   if (!TInfo)
1047     return 0;
1048   QualType T = TInfo->getType();
1049 
1050   NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1051   if (QualifierLoc) {
1052     QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1053                                                        TemplateArgs);
1054     if (!QualifierLoc)
1055       return 0;
1056   }
1057 
1058   // If we're instantiating a local function declaration, put the result
1059   // in the owner;  otherwise we need to find the instantiated context.
1060   DeclContext *DC;
1061   if (D->getDeclContext()->isFunctionOrMethod())
1062     DC = Owner;
1063   else if (isFriend && QualifierLoc) {
1064     CXXScopeSpec SS;
1065     SS.Adopt(QualifierLoc);
1066     DC = SemaRef.computeDeclContext(SS);
1067     if (!DC) return 0;
1068   } else {
1069     DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1070                                          TemplateArgs);
1071   }
1072 
1073   FunctionDecl *Function =
1074       FunctionDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
1075                            D->getLocation(), D->getDeclName(), T, TInfo,
1076                            D->getStorageClass(), D->getStorageClassAsWritten(),
1077                            D->isInlineSpecified(), D->hasWrittenPrototype());
1078 
1079   if (QualifierLoc)
1080     Function->setQualifierInfo(QualifierLoc);
1081 
1082   DeclContext *LexicalDC = Owner;
1083   if (!isFriend && D->isOutOfLine()) {
1084     assert(D->getDeclContext()->isFileContext());
1085     LexicalDC = D->getDeclContext();
1086   }
1087 
1088   Function->setLexicalDeclContext(LexicalDC);
1089 
1090   // Attach the parameters
1091   if (isa<FunctionProtoType>(Function->getType().IgnoreParens())) {
1092     // Adopt the already-instantiated parameters into our own context.
1093     for (unsigned P = 0; P < Params.size(); ++P)
1094       if (Params[P])
1095         Params[P]->setOwningFunction(Function);
1096   } else {
1097     // Since we were instantiated via a typedef of a function type, create
1098     // new parameters.
1099     const FunctionProtoType *Proto
1100       = Function->getType()->getAs<FunctionProtoType>();
1101     assert(Proto && "No function prototype in template instantiation?");
1102     for (FunctionProtoType::arg_type_iterator AI = Proto->arg_type_begin(),
1103          AE = Proto->arg_type_end(); AI != AE; ++AI) {
1104       ParmVarDecl *Param
1105         = SemaRef.BuildParmVarDeclForTypedef(Function, Function->getLocation(),
1106                                              *AI);
1107       Param->setScopeInfo(0, Params.size());
1108       Params.push_back(Param);
1109     }
1110   }
1111   Function->setParams(Params.data(), Params.size());
1112 
1113   SourceLocation InstantiateAtPOI;
1114   if (TemplateParams) {
1115     // Our resulting instantiation is actually a function template, since we
1116     // are substituting only the outer template parameters. For example, given
1117     //
1118     //   template<typename T>
1119     //   struct X {
1120     //     template<typename U> friend void f(T, U);
1121     //   };
1122     //
1123     //   X<int> x;
1124     //
1125     // We are instantiating the friend function template "f" within X<int>,
1126     // which means substituting int for T, but leaving "f" as a friend function
1127     // template.
1128     // Build the function template itself.
1129     FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1130                                                     Function->getLocation(),
1131                                                     Function->getDeclName(),
1132                                                     TemplateParams, Function);
1133     Function->setDescribedFunctionTemplate(FunctionTemplate);
1134 
1135     FunctionTemplate->setLexicalDeclContext(LexicalDC);
1136 
1137     if (isFriend && D->isThisDeclarationADefinition()) {
1138       // TODO: should we remember this connection regardless of whether
1139       // the friend declaration provided a body?
1140       FunctionTemplate->setInstantiatedFromMemberTemplate(
1141                                            D->getDescribedFunctionTemplate());
1142     }
1143   } else if (FunctionTemplate) {
1144     // Record this function template specialization.
1145     std::pair<const TemplateArgument *, unsigned> Innermost
1146       = TemplateArgs.getInnermost();
1147     Function->setFunctionTemplateSpecialization(FunctionTemplate,
1148                             TemplateArgumentList::CreateCopy(SemaRef.Context,
1149                                                              Innermost.first,
1150                                                              Innermost.second),
1151                                                 InsertPos);
1152   } else if (isFriend && D->isThisDeclarationADefinition()) {
1153     // TODO: should we remember this connection regardless of whether
1154     // the friend declaration provided a body?
1155     Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1156   }
1157 
1158   if (InitFunctionInstantiation(Function, D))
1159     Function->setInvalidDecl();
1160 
1161   bool Redeclaration = false;
1162   bool isExplicitSpecialization = false;
1163 
1164   LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1165                         Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1166 
1167   if (DependentFunctionTemplateSpecializationInfo *Info
1168         = D->getDependentSpecializationInfo()) {
1169     assert(isFriend && "non-friend has dependent specialization info?");
1170 
1171     // This needs to be set now for future sanity.
1172     Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1173 
1174     // Instantiate the explicit template arguments.
1175     TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1176                                           Info->getRAngleLoc());
1177     if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(),
1178                       ExplicitArgs, TemplateArgs))
1179       return 0;
1180 
1181     // Map the candidate templates to their instantiations.
1182     for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1183       Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1184                                                 Info->getTemplate(I),
1185                                                 TemplateArgs);
1186       if (!Temp) return 0;
1187 
1188       Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1189     }
1190 
1191     if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1192                                                     &ExplicitArgs,
1193                                                     Previous))
1194       Function->setInvalidDecl();
1195 
1196     isExplicitSpecialization = true;
1197 
1198   } else if (TemplateParams || !FunctionTemplate) {
1199     // Look only into the namespace where the friend would be declared to
1200     // find a previous declaration. This is the innermost enclosing namespace,
1201     // as described in ActOnFriendFunctionDecl.
1202     SemaRef.LookupQualifiedName(Previous, DC);
1203 
1204     // In C++, the previous declaration we find might be a tag type
1205     // (class or enum). In this case, the new declaration will hide the
1206     // tag type. Note that this does does not apply if we're declaring a
1207     // typedef (C++ [dcl.typedef]p4).
1208     if (Previous.isSingleTagDecl())
1209       Previous.clear();
1210   }
1211 
1212   SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1213                                    isExplicitSpecialization, Redeclaration);
1214 
1215   NamedDecl *PrincipalDecl = (TemplateParams
1216                               ? cast<NamedDecl>(FunctionTemplate)
1217                               : Function);
1218 
1219   // If the original function was part of a friend declaration,
1220   // inherit its namespace state and add it to the owner.
1221   if (isFriend) {
1222     NamedDecl *PrevDecl;
1223     if (TemplateParams)
1224       PrevDecl = FunctionTemplate->getPreviousDeclaration();
1225     else
1226       PrevDecl = Function->getPreviousDeclaration();
1227 
1228     PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0);
1229     DC->makeDeclVisibleInContext(PrincipalDecl, /*Recoverable=*/ false);
1230 
1231     bool queuedInstantiation = false;
1232 
1233     if (!SemaRef.getLangOptions().CPlusPlus0x &&
1234         D->isThisDeclarationADefinition()) {
1235       // Check for a function body.
1236       const FunctionDecl *Definition = 0;
1237       if (Function->isDefined(Definition) &&
1238           Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1239         SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1240           << Function->getDeclName();
1241         SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1242         Function->setInvalidDecl();
1243       }
1244       // Check for redefinitions due to other instantiations of this or
1245       // a similar friend function.
1246       else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1247                                            REnd = Function->redecls_end();
1248                 R != REnd; ++R) {
1249         if (*R == Function)
1250           continue;
1251         switch (R->getFriendObjectKind()) {
1252         case Decl::FOK_None:
1253           if (!queuedInstantiation && R->isUsed(false)) {
1254             if (MemberSpecializationInfo *MSInfo
1255                 = Function->getMemberSpecializationInfo()) {
1256               if (MSInfo->getPointOfInstantiation().isInvalid()) {
1257                 SourceLocation Loc = R->getLocation(); // FIXME
1258                 MSInfo->setPointOfInstantiation(Loc);
1259                 SemaRef.PendingLocalImplicitInstantiations.push_back(
1260                                                  std::make_pair(Function, Loc));
1261                 queuedInstantiation = true;
1262               }
1263             }
1264           }
1265           break;
1266         default:
1267           if (const FunctionDecl *RPattern
1268               = R->getTemplateInstantiationPattern())
1269             if (RPattern->isDefined(RPattern)) {
1270               SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1271                 << Function->getDeclName();
1272               SemaRef.Diag(R->getLocation(), diag::note_previous_definition);
1273               Function->setInvalidDecl();
1274               break;
1275             }
1276         }
1277       }
1278     }
1279   }
1280 
1281   if (Function->isOverloadedOperator() && !DC->isRecord() &&
1282       PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1283     PrincipalDecl->setNonMemberOperator();
1284 
1285   assert(!D->isDefaulted() && "only methods should be defaulted");
1286   return Function;
1287 }
1288 
1289 Decl *
VisitCXXMethodDecl(CXXMethodDecl * D,TemplateParameterList * TemplateParams)1290 TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1291                                       TemplateParameterList *TemplateParams) {
1292   FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1293   void *InsertPos = 0;
1294   if (FunctionTemplate && !TemplateParams) {
1295     // We are creating a function template specialization from a function
1296     // template. Check whether there is already a function template
1297     // specialization for this particular set of template arguments.
1298     std::pair<const TemplateArgument *, unsigned> Innermost
1299       = TemplateArgs.getInnermost();
1300 
1301     FunctionDecl *SpecFunc
1302       = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
1303                                              InsertPos);
1304 
1305     // If we already have a function template specialization, return it.
1306     if (SpecFunc)
1307       return SpecFunc;
1308   }
1309 
1310   bool isFriend;
1311   if (FunctionTemplate)
1312     isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1313   else
1314     isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1315 
1316   bool MergeWithParentScope = (TemplateParams != 0) ||
1317     !(isa<Decl>(Owner) &&
1318       cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1319   LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1320 
1321   // Instantiate enclosing template arguments for friends.
1322   llvm::SmallVector<TemplateParameterList *, 4> TempParamLists;
1323   unsigned NumTempParamLists = 0;
1324   if (isFriend && (NumTempParamLists = D->getNumTemplateParameterLists())) {
1325     TempParamLists.set_size(NumTempParamLists);
1326     for (unsigned I = 0; I != NumTempParamLists; ++I) {
1327       TemplateParameterList *TempParams = D->getTemplateParameterList(I);
1328       TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1329       if (!InstParams)
1330         return NULL;
1331       TempParamLists[I] = InstParams;
1332     }
1333   }
1334 
1335   llvm::SmallVector<ParmVarDecl *, 4> Params;
1336   TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1337   TInfo = SubstFunctionType(D, Params);
1338   if (!TInfo)
1339     return 0;
1340   QualType T = TInfo->getType();
1341 
1342   // \brief If the type of this function, after ignoring parentheses,
1343   // is not *directly* a function type, then we're instantiating a function
1344   // that was declared via a typedef, e.g.,
1345   //
1346   //   typedef int functype(int, int);
1347   //   functype func;
1348   //
1349   // In this case, we'll just go instantiate the ParmVarDecls that we
1350   // synthesized in the method declaration.
1351   if (!isa<FunctionProtoType>(T.IgnoreParens())) {
1352     assert(!Params.size() && "Instantiating type could not yield parameters");
1353     llvm::SmallVector<QualType, 4> ParamTypes;
1354     if (SemaRef.SubstParmTypes(D->getLocation(), D->param_begin(),
1355                                D->getNumParams(), TemplateArgs, ParamTypes,
1356                                &Params))
1357       return 0;
1358   }
1359 
1360   NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1361   if (QualifierLoc) {
1362     QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1363                                                  TemplateArgs);
1364     if (!QualifierLoc)
1365       return 0;
1366   }
1367 
1368   DeclContext *DC = Owner;
1369   if (isFriend) {
1370     if (QualifierLoc) {
1371       CXXScopeSpec SS;
1372       SS.Adopt(QualifierLoc);
1373       DC = SemaRef.computeDeclContext(SS);
1374 
1375       if (DC && SemaRef.RequireCompleteDeclContext(SS, DC))
1376         return 0;
1377     } else {
1378       DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1379                                            D->getDeclContext(),
1380                                            TemplateArgs);
1381     }
1382     if (!DC) return 0;
1383   }
1384 
1385   // Build the instantiated method declaration.
1386   CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1387   CXXMethodDecl *Method = 0;
1388 
1389   SourceLocation StartLoc = D->getInnerLocStart();
1390   DeclarationNameInfo NameInfo
1391     = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1392   if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1393     Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1394                                         StartLoc, NameInfo, T, TInfo,
1395                                         Constructor->isExplicit(),
1396                                         Constructor->isInlineSpecified(),
1397                                         false);
1398   } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1399     Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1400                                        StartLoc, NameInfo, T, TInfo,
1401                                        Destructor->isInlineSpecified(),
1402                                        false);
1403   } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1404     Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1405                                        StartLoc, NameInfo, T, TInfo,
1406                                        Conversion->isInlineSpecified(),
1407                                        Conversion->isExplicit(),
1408                                        Conversion->getLocEnd());
1409   } else {
1410     Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1411                                    StartLoc, NameInfo, T, TInfo,
1412                                    D->isStatic(),
1413                                    D->getStorageClassAsWritten(),
1414                                    D->isInlineSpecified(),
1415                                    D->getLocEnd());
1416   }
1417 
1418   if (QualifierLoc)
1419     Method->setQualifierInfo(QualifierLoc);
1420 
1421   if (TemplateParams) {
1422     // Our resulting instantiation is actually a function template, since we
1423     // are substituting only the outer template parameters. For example, given
1424     //
1425     //   template<typename T>
1426     //   struct X {
1427     //     template<typename U> void f(T, U);
1428     //   };
1429     //
1430     //   X<int> x;
1431     //
1432     // We are instantiating the member template "f" within X<int>, which means
1433     // substituting int for T, but leaving "f" as a member function template.
1434     // Build the function template itself.
1435     FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1436                                                     Method->getLocation(),
1437                                                     Method->getDeclName(),
1438                                                     TemplateParams, Method);
1439     if (isFriend) {
1440       FunctionTemplate->setLexicalDeclContext(Owner);
1441       FunctionTemplate->setObjectOfFriendDecl(true);
1442     } else if (D->isOutOfLine())
1443       FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1444     Method->setDescribedFunctionTemplate(FunctionTemplate);
1445   } else if (FunctionTemplate) {
1446     // Record this function template specialization.
1447     std::pair<const TemplateArgument *, unsigned> Innermost
1448       = TemplateArgs.getInnermost();
1449     Method->setFunctionTemplateSpecialization(FunctionTemplate,
1450                          TemplateArgumentList::CreateCopy(SemaRef.Context,
1451                                                           Innermost.first,
1452                                                           Innermost.second),
1453                                               InsertPos);
1454   } else if (!isFriend) {
1455     // Record that this is an instantiation of a member function.
1456     Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1457   }
1458 
1459   // If we are instantiating a member function defined
1460   // out-of-line, the instantiation will have the same lexical
1461   // context (which will be a namespace scope) as the template.
1462   if (isFriend) {
1463     if (NumTempParamLists)
1464       Method->setTemplateParameterListsInfo(SemaRef.Context,
1465                                             NumTempParamLists,
1466                                             TempParamLists.data());
1467 
1468     Method->setLexicalDeclContext(Owner);
1469     Method->setObjectOfFriendDecl(true);
1470   } else if (D->isOutOfLine())
1471     Method->setLexicalDeclContext(D->getLexicalDeclContext());
1472 
1473   // Attach the parameters
1474   for (unsigned P = 0; P < Params.size(); ++P)
1475     Params[P]->setOwningFunction(Method);
1476   Method->setParams(Params.data(), Params.size());
1477 
1478   if (InitMethodInstantiation(Method, D))
1479     Method->setInvalidDecl();
1480 
1481   LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
1482                         Sema::ForRedeclaration);
1483 
1484   if (!FunctionTemplate || TemplateParams || isFriend) {
1485     SemaRef.LookupQualifiedName(Previous, Record);
1486 
1487     // In C++, the previous declaration we find might be a tag type
1488     // (class or enum). In this case, the new declaration will hide the
1489     // tag type. Note that this does does not apply if we're declaring a
1490     // typedef (C++ [dcl.typedef]p4).
1491     if (Previous.isSingleTagDecl())
1492       Previous.clear();
1493   }
1494 
1495   bool Redeclaration = false;
1496   SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration);
1497 
1498   if (D->isPure())
1499     SemaRef.CheckPureMethod(Method, SourceRange());
1500 
1501   Method->setAccess(D->getAccess());
1502 
1503   SemaRef.CheckOverrideControl(Method);
1504 
1505   if (FunctionTemplate) {
1506     // If there's a function template, let our caller handle it.
1507   } else if (Method->isInvalidDecl() && !Previous.empty()) {
1508     // Don't hide a (potentially) valid declaration with an invalid one.
1509   } else {
1510     NamedDecl *DeclToAdd = (TemplateParams
1511                             ? cast<NamedDecl>(FunctionTemplate)
1512                             : Method);
1513     if (isFriend)
1514       Record->makeDeclVisibleInContext(DeclToAdd);
1515     else
1516       Owner->addDecl(DeclToAdd);
1517   }
1518 
1519   if (D->isExplicitlyDefaulted()) {
1520     SemaRef.SetDeclDefaulted(Method, Method->getLocation());
1521   } else {
1522     assert(!D->isDefaulted() &&
1523            "should not implicitly default uninstantiated function");
1524   }
1525 
1526   return Method;
1527 }
1528 
VisitCXXConstructorDecl(CXXConstructorDecl * D)1529 Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1530   return VisitCXXMethodDecl(D);
1531 }
1532 
VisitCXXDestructorDecl(CXXDestructorDecl * D)1533 Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1534   return VisitCXXMethodDecl(D);
1535 }
1536 
VisitCXXConversionDecl(CXXConversionDecl * D)1537 Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1538   return VisitCXXMethodDecl(D);
1539 }
1540 
VisitParmVarDecl(ParmVarDecl * D)1541 ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1542   return SemaRef.SubstParmVarDecl(D, TemplateArgs, /*indexAdjustment*/ 0,
1543                                   llvm::Optional<unsigned>());
1544 }
1545 
VisitTemplateTypeParmDecl(TemplateTypeParmDecl * D)1546 Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1547                                                     TemplateTypeParmDecl *D) {
1548   // TODO: don't always clone when decls are refcounted.
1549   assert(D->getTypeForDecl()->isTemplateTypeParmType());
1550 
1551   TemplateTypeParmDecl *Inst =
1552     TemplateTypeParmDecl::Create(SemaRef.Context, Owner,
1553                                  D->getLocStart(), D->getLocation(),
1554                                  D->getDepth() - TemplateArgs.getNumLevels(),
1555                                  D->getIndex(), D->getIdentifier(),
1556                                  D->wasDeclaredWithTypename(),
1557                                  D->isParameterPack());
1558   Inst->setAccess(AS_public);
1559 
1560   if (D->hasDefaultArgument())
1561     Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1562 
1563   // Introduce this template parameter's instantiation into the instantiation
1564   // scope.
1565   SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1566 
1567   return Inst;
1568 }
1569 
VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl * D)1570 Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1571                                                  NonTypeTemplateParmDecl *D) {
1572   // Substitute into the type of the non-type template parameter.
1573   TypeLoc TL = D->getTypeSourceInfo()->getTypeLoc();
1574   llvm::SmallVector<TypeSourceInfo *, 4> ExpandedParameterPackTypesAsWritten;
1575   llvm::SmallVector<QualType, 4> ExpandedParameterPackTypes;
1576   bool IsExpandedParameterPack = false;
1577   TypeSourceInfo *DI;
1578   QualType T;
1579   bool Invalid = false;
1580 
1581   if (D->isExpandedParameterPack()) {
1582     // The non-type template parameter pack is an already-expanded pack
1583     // expansion of types. Substitute into each of the expanded types.
1584     ExpandedParameterPackTypes.reserve(D->getNumExpansionTypes());
1585     ExpandedParameterPackTypesAsWritten.reserve(D->getNumExpansionTypes());
1586     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1587       TypeSourceInfo *NewDI =SemaRef.SubstType(D->getExpansionTypeSourceInfo(I),
1588                                                TemplateArgs,
1589                                                D->getLocation(),
1590                                                D->getDeclName());
1591       if (!NewDI)
1592         return 0;
1593 
1594       ExpandedParameterPackTypesAsWritten.push_back(NewDI);
1595       QualType NewT =SemaRef.CheckNonTypeTemplateParameterType(NewDI->getType(),
1596                                                               D->getLocation());
1597       if (NewT.isNull())
1598         return 0;
1599       ExpandedParameterPackTypes.push_back(NewT);
1600     }
1601 
1602     IsExpandedParameterPack = true;
1603     DI = D->getTypeSourceInfo();
1604     T = DI->getType();
1605   } else if (isa<PackExpansionTypeLoc>(TL)) {
1606     // The non-type template parameter pack's type is a pack expansion of types.
1607     // Determine whether we need to expand this parameter pack into separate
1608     // types.
1609     PackExpansionTypeLoc Expansion = cast<PackExpansionTypeLoc>(TL);
1610     TypeLoc Pattern = Expansion.getPatternLoc();
1611     llvm::SmallVector<UnexpandedParameterPack, 2> Unexpanded;
1612     SemaRef.collectUnexpandedParameterPacks(Pattern, Unexpanded);
1613 
1614     // Determine whether the set of unexpanded parameter packs can and should
1615     // be expanded.
1616     bool Expand = true;
1617     bool RetainExpansion = false;
1618     llvm::Optional<unsigned> OrigNumExpansions
1619       = Expansion.getTypePtr()->getNumExpansions();
1620     llvm::Optional<unsigned> NumExpansions = OrigNumExpansions;
1621     if (SemaRef.CheckParameterPacksForExpansion(Expansion.getEllipsisLoc(),
1622                                                 Pattern.getSourceRange(),
1623                                                 Unexpanded.data(),
1624                                                 Unexpanded.size(),
1625                                                 TemplateArgs,
1626                                                 Expand, RetainExpansion,
1627                                                 NumExpansions))
1628       return 0;
1629 
1630     if (Expand) {
1631       for (unsigned I = 0; I != *NumExpansions; ++I) {
1632         Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
1633         TypeSourceInfo *NewDI = SemaRef.SubstType(Pattern, TemplateArgs,
1634                                                   D->getLocation(),
1635                                                   D->getDeclName());
1636         if (!NewDI)
1637           return 0;
1638 
1639         ExpandedParameterPackTypesAsWritten.push_back(NewDI);
1640         QualType NewT = SemaRef.CheckNonTypeTemplateParameterType(
1641                                                               NewDI->getType(),
1642                                                               D->getLocation());
1643         if (NewT.isNull())
1644           return 0;
1645         ExpandedParameterPackTypes.push_back(NewT);
1646       }
1647 
1648       // Note that we have an expanded parameter pack. The "type" of this
1649       // expanded parameter pack is the original expansion type, but callers
1650       // will end up using the expanded parameter pack types for type-checking.
1651       IsExpandedParameterPack = true;
1652       DI = D->getTypeSourceInfo();
1653       T = DI->getType();
1654     } else {
1655       // We cannot fully expand the pack expansion now, so substitute into the
1656       // pattern and create a new pack expansion type.
1657       Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
1658       TypeSourceInfo *NewPattern = SemaRef.SubstType(Pattern, TemplateArgs,
1659                                                      D->getLocation(),
1660                                                      D->getDeclName());
1661       if (!NewPattern)
1662         return 0;
1663 
1664       DI = SemaRef.CheckPackExpansion(NewPattern, Expansion.getEllipsisLoc(),
1665                                       NumExpansions);
1666       if (!DI)
1667         return 0;
1668 
1669       T = DI->getType();
1670     }
1671   } else {
1672     // Simple case: substitution into a parameter that is not a parameter pack.
1673     DI = SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
1674                            D->getLocation(), D->getDeclName());
1675     if (!DI)
1676       return 0;
1677 
1678     // Check that this type is acceptable for a non-type template parameter.
1679     T = SemaRef.CheckNonTypeTemplateParameterType(DI->getType(),
1680                                                   D->getLocation());
1681     if (T.isNull()) {
1682       T = SemaRef.Context.IntTy;
1683       Invalid = true;
1684     }
1685   }
1686 
1687   NonTypeTemplateParmDecl *Param;
1688   if (IsExpandedParameterPack)
1689     Param = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner,
1690                                             D->getInnerLocStart(),
1691                                             D->getLocation(),
1692                                     D->getDepth() - TemplateArgs.getNumLevels(),
1693                                             D->getPosition(),
1694                                             D->getIdentifier(), T,
1695                                             DI,
1696                                             ExpandedParameterPackTypes.data(),
1697                                             ExpandedParameterPackTypes.size(),
1698                                     ExpandedParameterPackTypesAsWritten.data());
1699   else
1700     Param = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner,
1701                                             D->getInnerLocStart(),
1702                                             D->getLocation(),
1703                                     D->getDepth() - TemplateArgs.getNumLevels(),
1704                                             D->getPosition(),
1705                                             D->getIdentifier(), T,
1706                                             D->isParameterPack(), DI);
1707 
1708   Param->setAccess(AS_public);
1709   if (Invalid)
1710     Param->setInvalidDecl();
1711 
1712   Param->setDefaultArgument(D->getDefaultArgument(), false);
1713 
1714   // Introduce this template parameter's instantiation into the instantiation
1715   // scope.
1716   SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1717   return Param;
1718 }
1719 
1720 Decl *
VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl * D)1721 TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1722                                                   TemplateTemplateParmDecl *D) {
1723   // Instantiate the template parameter list of the template template parameter.
1724   TemplateParameterList *TempParams = D->getTemplateParameters();
1725   TemplateParameterList *InstParams;
1726   {
1727     // Perform the actual substitution of template parameters within a new,
1728     // local instantiation scope.
1729     LocalInstantiationScope Scope(SemaRef);
1730     InstParams = SubstTemplateParams(TempParams);
1731     if (!InstParams)
1732       return NULL;
1733   }
1734 
1735   // Build the template template parameter.
1736   TemplateTemplateParmDecl *Param
1737     = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1738                                    D->getDepth() - TemplateArgs.getNumLevels(),
1739                                        D->getPosition(), D->isParameterPack(),
1740                                        D->getIdentifier(), InstParams);
1741   Param->setDefaultArgument(D->getDefaultArgument(), false);
1742   Param->setAccess(AS_public);
1743 
1744   // Introduce this template parameter's instantiation into the instantiation
1745   // scope.
1746   SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1747 
1748   return Param;
1749 }
1750 
VisitUsingDirectiveDecl(UsingDirectiveDecl * D)1751 Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1752   // Using directives are never dependent (and never contain any types or
1753   // expressions), so they require no explicit instantiation work.
1754 
1755   UsingDirectiveDecl *Inst
1756     = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1757                                  D->getNamespaceKeyLocation(),
1758                                  D->getQualifierLoc(),
1759                                  D->getIdentLocation(),
1760                                  D->getNominatedNamespace(),
1761                                  D->getCommonAncestor());
1762   Owner->addDecl(Inst);
1763   return Inst;
1764 }
1765 
VisitUsingDecl(UsingDecl * D)1766 Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1767 
1768   // The nested name specifier may be dependent, for example
1769   //     template <typename T> struct t {
1770   //       struct s1 { T f1(); };
1771   //       struct s2 : s1 { using s1::f1; };
1772   //     };
1773   //     template struct t<int>;
1774   // Here, in using s1::f1, s1 refers to t<T>::s1;
1775   // we need to substitute for t<int>::s1.
1776   NestedNameSpecifierLoc QualifierLoc
1777     = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
1778                                           TemplateArgs);
1779   if (!QualifierLoc)
1780     return 0;
1781 
1782   // The name info is non-dependent, so no transformation
1783   // is required.
1784   DeclarationNameInfo NameInfo = D->getNameInfo();
1785 
1786   // We only need to do redeclaration lookups if we're in a class
1787   // scope (in fact, it's not really even possible in non-class
1788   // scopes).
1789   bool CheckRedeclaration = Owner->isRecord();
1790 
1791   LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
1792                     Sema::ForRedeclaration);
1793 
1794   UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1795                                        D->getUsingLocation(),
1796                                        QualifierLoc,
1797                                        NameInfo,
1798                                        D->isTypeName());
1799 
1800   CXXScopeSpec SS;
1801   SS.Adopt(QualifierLoc);
1802   if (CheckRedeclaration) {
1803     Prev.setHideTags(false);
1804     SemaRef.LookupQualifiedName(Prev, Owner);
1805 
1806     // Check for invalid redeclarations.
1807     if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1808                                             D->isTypeName(), SS,
1809                                             D->getLocation(), Prev))
1810       NewUD->setInvalidDecl();
1811 
1812   }
1813 
1814   if (!NewUD->isInvalidDecl() &&
1815       SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1816                                       D->getLocation()))
1817     NewUD->setInvalidDecl();
1818 
1819   SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1820   NewUD->setAccess(D->getAccess());
1821   Owner->addDecl(NewUD);
1822 
1823   // Don't process the shadow decls for an invalid decl.
1824   if (NewUD->isInvalidDecl())
1825     return NewUD;
1826 
1827   bool isFunctionScope = Owner->isFunctionOrMethod();
1828 
1829   // Process the shadow decls.
1830   for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1831          I != E; ++I) {
1832     UsingShadowDecl *Shadow = *I;
1833     NamedDecl *InstTarget =
1834       cast_or_null<NamedDecl>(SemaRef.FindInstantiatedDecl(
1835                                                           Shadow->getLocation(),
1836                                                         Shadow->getTargetDecl(),
1837                                                            TemplateArgs));
1838     if (!InstTarget)
1839       return 0;
1840 
1841     if (CheckRedeclaration &&
1842         SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1843       continue;
1844 
1845     UsingShadowDecl *InstShadow
1846       = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1847     SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1848 
1849     if (isFunctionScope)
1850       SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1851   }
1852 
1853   return NewUD;
1854 }
1855 
VisitUsingShadowDecl(UsingShadowDecl * D)1856 Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1857   // Ignore these;  we handle them in bulk when processing the UsingDecl.
1858   return 0;
1859 }
1860 
1861 Decl * TemplateDeclInstantiator
VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl * D)1862     ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1863   NestedNameSpecifierLoc QualifierLoc
1864     = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
1865                                           TemplateArgs);
1866   if (!QualifierLoc)
1867     return 0;
1868 
1869   CXXScopeSpec SS;
1870   SS.Adopt(QualifierLoc);
1871 
1872   // Since NameInfo refers to a typename, it cannot be a C++ special name.
1873   // Hence, no tranformation is required for it.
1874   DeclarationNameInfo NameInfo(D->getDeclName(), D->getLocation());
1875   NamedDecl *UD =
1876     SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1877                                   D->getUsingLoc(), SS, NameInfo, 0,
1878                                   /*instantiation*/ true,
1879                                   /*typename*/ true, D->getTypenameLoc());
1880   if (UD)
1881     SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1882 
1883   return UD;
1884 }
1885 
1886 Decl * TemplateDeclInstantiator
VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl * D)1887     ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1888   NestedNameSpecifierLoc QualifierLoc
1889       = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(), TemplateArgs);
1890   if (!QualifierLoc)
1891     return 0;
1892 
1893   CXXScopeSpec SS;
1894   SS.Adopt(QualifierLoc);
1895 
1896   DeclarationNameInfo NameInfo
1897     = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1898 
1899   NamedDecl *UD =
1900     SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1901                                   D->getUsingLoc(), SS, NameInfo, 0,
1902                                   /*instantiation*/ true,
1903                                   /*typename*/ false, SourceLocation());
1904   if (UD)
1905     SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1906 
1907   return UD;
1908 }
1909 
SubstDecl(Decl * D,DeclContext * Owner,const MultiLevelTemplateArgumentList & TemplateArgs)1910 Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1911                       const MultiLevelTemplateArgumentList &TemplateArgs) {
1912   TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1913   if (D->isInvalidDecl())
1914     return 0;
1915 
1916   return Instantiator.Visit(D);
1917 }
1918 
1919 /// \brief Instantiates a nested template parameter list in the current
1920 /// instantiation context.
1921 ///
1922 /// \param L The parameter list to instantiate
1923 ///
1924 /// \returns NULL if there was an error
1925 TemplateParameterList *
SubstTemplateParams(TemplateParameterList * L)1926 TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1927   // Get errors for all the parameters before bailing out.
1928   bool Invalid = false;
1929 
1930   unsigned N = L->size();
1931   typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1932   ParamVector Params;
1933   Params.reserve(N);
1934   for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1935        PI != PE; ++PI) {
1936     NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1937     Params.push_back(D);
1938     Invalid = Invalid || !D || D->isInvalidDecl();
1939   }
1940 
1941   // Clean up if we had an error.
1942   if (Invalid)
1943     return NULL;
1944 
1945   TemplateParameterList *InstL
1946     = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1947                                     L->getLAngleLoc(), &Params.front(), N,
1948                                     L->getRAngleLoc());
1949   return InstL;
1950 }
1951 
1952 /// \brief Instantiate the declaration of a class template partial
1953 /// specialization.
1954 ///
1955 /// \param ClassTemplate the (instantiated) class template that is partially
1956 // specialized by the instantiation of \p PartialSpec.
1957 ///
1958 /// \param PartialSpec the (uninstantiated) class template partial
1959 /// specialization that we are instantiating.
1960 ///
1961 /// \returns The instantiated partial specialization, if successful; otherwise,
1962 /// NULL to indicate an error.
1963 ClassTemplatePartialSpecializationDecl *
InstantiateClassTemplatePartialSpecialization(ClassTemplateDecl * ClassTemplate,ClassTemplatePartialSpecializationDecl * PartialSpec)1964 TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1965                                             ClassTemplateDecl *ClassTemplate,
1966                           ClassTemplatePartialSpecializationDecl *PartialSpec) {
1967   // Create a local instantiation scope for this class template partial
1968   // specialization, which will contain the instantiations of the template
1969   // parameters.
1970   LocalInstantiationScope Scope(SemaRef);
1971 
1972   // Substitute into the template parameters of the class template partial
1973   // specialization.
1974   TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1975   TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1976   if (!InstParams)
1977     return 0;
1978 
1979   // Substitute into the template arguments of the class template partial
1980   // specialization.
1981   TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1982   if (SemaRef.Subst(PartialSpec->getTemplateArgsAsWritten(),
1983                     PartialSpec->getNumTemplateArgsAsWritten(),
1984                     InstTemplateArgs, TemplateArgs))
1985     return 0;
1986 
1987   // Check that the template argument list is well-formed for this
1988   // class template.
1989   llvm::SmallVector<TemplateArgument, 4> Converted;
1990   if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1991                                         PartialSpec->getLocation(),
1992                                         InstTemplateArgs,
1993                                         false,
1994                                         Converted))
1995     return 0;
1996 
1997   // Figure out where to insert this class template partial specialization
1998   // in the member template's set of class template partial specializations.
1999   void *InsertPos = 0;
2000   ClassTemplateSpecializationDecl *PrevDecl
2001     = ClassTemplate->findPartialSpecialization(Converted.data(),
2002                                                Converted.size(), InsertPos);
2003 
2004   // Build the canonical type that describes the converted template
2005   // arguments of the class template partial specialization.
2006   QualType CanonType
2007     = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
2008                                                     Converted.data(),
2009                                                     Converted.size());
2010 
2011   // Build the fully-sugared type for this class template
2012   // specialization as the user wrote in the specialization
2013   // itself. This means that we'll pretty-print the type retrieved
2014   // from the specialization's declaration the way that the user
2015   // actually wrote the specialization, rather than formatting the
2016   // name based on the "canonical" representation used to store the
2017   // template arguments in the specialization.
2018   TypeSourceInfo *WrittenTy
2019     = SemaRef.Context.getTemplateSpecializationTypeInfo(
2020                                                     TemplateName(ClassTemplate),
2021                                                     PartialSpec->getLocation(),
2022                                                     InstTemplateArgs,
2023                                                     CanonType);
2024 
2025   if (PrevDecl) {
2026     // We've already seen a partial specialization with the same template
2027     // parameters and template arguments. This can happen, for example, when
2028     // substituting the outer template arguments ends up causing two
2029     // class template partial specializations of a member class template
2030     // to have identical forms, e.g.,
2031     //
2032     //   template<typename T, typename U>
2033     //   struct Outer {
2034     //     template<typename X, typename Y> struct Inner;
2035     //     template<typename Y> struct Inner<T, Y>;
2036     //     template<typename Y> struct Inner<U, Y>;
2037     //   };
2038     //
2039     //   Outer<int, int> outer; // error: the partial specializations of Inner
2040     //                          // have the same signature.
2041     SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
2042       << WrittenTy->getType();
2043     SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
2044       << SemaRef.Context.getTypeDeclType(PrevDecl);
2045     return 0;
2046   }
2047 
2048 
2049   // Create the class template partial specialization declaration.
2050   ClassTemplatePartialSpecializationDecl *InstPartialSpec
2051     = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
2052                                                      PartialSpec->getTagKind(),
2053                                                      Owner,
2054                                                      PartialSpec->getLocStart(),
2055                                                      PartialSpec->getLocation(),
2056                                                      InstParams,
2057                                                      ClassTemplate,
2058                                                      Converted.data(),
2059                                                      Converted.size(),
2060                                                      InstTemplateArgs,
2061                                                      CanonType,
2062                                                      0,
2063                              ClassTemplate->getNextPartialSpecSequenceNumber());
2064   // Substitute the nested name specifier, if any.
2065   if (SubstQualifier(PartialSpec, InstPartialSpec))
2066     return 0;
2067 
2068   InstPartialSpec->setInstantiatedFromMember(PartialSpec);
2069   InstPartialSpec->setTypeAsWritten(WrittenTy);
2070 
2071   // Add this partial specialization to the set of class template partial
2072   // specializations.
2073   ClassTemplate->AddPartialSpecialization(InstPartialSpec, InsertPos);
2074   return InstPartialSpec;
2075 }
2076 
2077 TypeSourceInfo*
SubstFunctionType(FunctionDecl * D,llvm::SmallVectorImpl<ParmVarDecl * > & Params)2078 TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
2079                               llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
2080   TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
2081   assert(OldTInfo && "substituting function without type source info");
2082   assert(Params.empty() && "parameter vector is non-empty at start");
2083   TypeSourceInfo *NewTInfo
2084     = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
2085                                     D->getTypeSpecStartLoc(),
2086                                     D->getDeclName());
2087   if (!NewTInfo)
2088     return 0;
2089 
2090   if (NewTInfo != OldTInfo) {
2091     // Get parameters from the new type info.
2092     TypeLoc OldTL = OldTInfo->getTypeLoc().IgnoreParens();
2093     if (FunctionProtoTypeLoc *OldProtoLoc
2094                                   = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
2095       TypeLoc NewTL = NewTInfo->getTypeLoc().IgnoreParens();
2096       FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
2097       assert(NewProtoLoc && "Missing prototype?");
2098       unsigned NewIdx = 0, NumNewParams = NewProtoLoc->getNumArgs();
2099       for (unsigned OldIdx = 0, NumOldParams = OldProtoLoc->getNumArgs();
2100            OldIdx != NumOldParams; ++OldIdx) {
2101         ParmVarDecl *OldParam = OldProtoLoc->getArg(OldIdx);
2102         if (!OldParam->isParameterPack() ||
2103             (NewIdx < NumNewParams &&
2104              NewProtoLoc->getArg(NewIdx)->isParameterPack())) {
2105           // Simple case: normal parameter, or a parameter pack that's
2106           // instantiated to a (still-dependent) parameter pack.
2107           ParmVarDecl *NewParam = NewProtoLoc->getArg(NewIdx++);
2108           Params.push_back(NewParam);
2109           SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldParam,
2110                                                                NewParam);
2111           continue;
2112         }
2113 
2114         // Parameter pack: make the instantiation an argument pack.
2115         SemaRef.CurrentInstantiationScope->MakeInstantiatedLocalArgPack(
2116                                                                       OldParam);
2117         unsigned NumArgumentsInExpansion
2118           = SemaRef.getNumArgumentsInExpansion(OldParam->getType(),
2119                                                TemplateArgs);
2120         while (NumArgumentsInExpansion--) {
2121           ParmVarDecl *NewParam = NewProtoLoc->getArg(NewIdx++);
2122           Params.push_back(NewParam);
2123           SemaRef.CurrentInstantiationScope->InstantiatedLocalPackArg(OldParam,
2124                                                                       NewParam);
2125         }
2126       }
2127     }
2128   } else {
2129     // The function type itself was not dependent and therefore no
2130     // substitution occurred. However, we still need to instantiate
2131     // the function parameters themselves.
2132     TypeLoc OldTL = OldTInfo->getTypeLoc().IgnoreParens();
2133     if (FunctionProtoTypeLoc *OldProtoLoc
2134                                     = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
2135       for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
2136         ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
2137         if (!Parm)
2138           return 0;
2139         Params.push_back(Parm);
2140       }
2141     }
2142   }
2143   return NewTInfo;
2144 }
2145 
2146 /// \brief Initializes the common fields of an instantiation function
2147 /// declaration (New) from the corresponding fields of its template (Tmpl).
2148 ///
2149 /// \returns true if there was an error
2150 bool
InitFunctionInstantiation(FunctionDecl * New,FunctionDecl * Tmpl)2151 TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
2152                                                     FunctionDecl *Tmpl) {
2153   if (Tmpl->isDeletedAsWritten())
2154     New->setDeletedAsWritten();
2155 
2156   // If we are performing substituting explicitly-specified template arguments
2157   // or deduced template arguments into a function template and we reach this
2158   // point, we are now past the point where SFINAE applies and have committed
2159   // to keeping the new function template specialization. We therefore
2160   // convert the active template instantiation for the function template
2161   // into a template instantiation for this specific function template
2162   // specialization, which is not a SFINAE context, so that we diagnose any
2163   // further errors in the declaration itself.
2164   typedef Sema::ActiveTemplateInstantiation ActiveInstType;
2165   ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
2166   if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
2167       ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
2168     if (FunctionTemplateDecl *FunTmpl
2169           = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
2170       assert(FunTmpl->getTemplatedDecl() == Tmpl &&
2171              "Deduction from the wrong function template?");
2172       (void) FunTmpl;
2173       ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
2174       ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
2175       --SemaRef.NonInstantiationEntries;
2176     }
2177   }
2178 
2179   const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
2180   assert(Proto && "Function template without prototype?");
2181 
2182   if (Proto->hasExceptionSpec() || Proto->getNoReturnAttr()) {
2183     // The function has an exception specification or a "noreturn"
2184     // attribute. Substitute into each of the exception types.
2185     llvm::SmallVector<QualType, 4> Exceptions;
2186     for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
2187       // FIXME: Poor location information!
2188       if (const PackExpansionType *PackExpansion
2189             = Proto->getExceptionType(I)->getAs<PackExpansionType>()) {
2190         // We have a pack expansion. Instantiate it.
2191         llvm::SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2192         SemaRef.collectUnexpandedParameterPacks(PackExpansion->getPattern(),
2193                                                 Unexpanded);
2194         assert(!Unexpanded.empty() &&
2195                "Pack expansion without parameter packs?");
2196 
2197         bool Expand = false;
2198         bool RetainExpansion = false;
2199         llvm::Optional<unsigned> NumExpansions
2200                                           = PackExpansion->getNumExpansions();
2201         if (SemaRef.CheckParameterPacksForExpansion(New->getLocation(),
2202                                                     SourceRange(),
2203                                                     Unexpanded.data(),
2204                                                     Unexpanded.size(),
2205                                                     TemplateArgs,
2206                                                     Expand,
2207                                                     RetainExpansion,
2208                                                     NumExpansions))
2209           break;
2210 
2211         if (!Expand) {
2212           // We can't expand this pack expansion into separate arguments yet;
2213           // just substitute into the pattern and create a new pack expansion
2214           // type.
2215           Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2216           QualType T = SemaRef.SubstType(PackExpansion->getPattern(),
2217                                          TemplateArgs,
2218                                        New->getLocation(), New->getDeclName());
2219           if (T.isNull())
2220             break;
2221 
2222           T = SemaRef.Context.getPackExpansionType(T, NumExpansions);
2223           Exceptions.push_back(T);
2224           continue;
2225         }
2226 
2227         // Substitute into the pack expansion pattern for each template
2228         bool Invalid = false;
2229         for (unsigned ArgIdx = 0; ArgIdx != *NumExpansions; ++ArgIdx) {
2230           Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, ArgIdx);
2231 
2232           QualType T = SemaRef.SubstType(PackExpansion->getPattern(),
2233                                          TemplateArgs,
2234                                        New->getLocation(), New->getDeclName());
2235           if (T.isNull()) {
2236             Invalid = true;
2237             break;
2238           }
2239 
2240           Exceptions.push_back(T);
2241         }
2242 
2243         if (Invalid)
2244           break;
2245 
2246         continue;
2247       }
2248 
2249       QualType T
2250         = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
2251                             New->getLocation(), New->getDeclName());
2252       if (T.isNull() ||
2253           SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
2254         continue;
2255 
2256       Exceptions.push_back(T);
2257     }
2258     Expr *NoexceptExpr = 0;
2259     if (Expr *OldNoexceptExpr = Proto->getNoexceptExpr()) {
2260       EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
2261       ExprResult E = SemaRef.SubstExpr(OldNoexceptExpr, TemplateArgs);
2262       if (E.isUsable())
2263         NoexceptExpr = E.take();
2264     }
2265 
2266     // Rebuild the function type
2267 
2268     FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
2269     EPI.ExceptionSpecType = Proto->getExceptionSpecType();
2270     EPI.NumExceptions = Exceptions.size();
2271     EPI.Exceptions = Exceptions.data();
2272     EPI.NoexceptExpr = NoexceptExpr;
2273     EPI.ExtInfo = Proto->getExtInfo();
2274 
2275     const FunctionProtoType *NewProto
2276       = New->getType()->getAs<FunctionProtoType>();
2277     assert(NewProto && "Template instantiation without function prototype?");
2278     New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
2279                                                  NewProto->arg_type_begin(),
2280                                                  NewProto->getNumArgs(),
2281                                                  EPI));
2282   }
2283 
2284   const FunctionDecl* Definition = Tmpl;
2285 
2286   // Get the definition. Leaves the variable unchanged if undefined.
2287   Tmpl->isDefined(Definition);
2288 
2289   SemaRef.InstantiateAttrs(TemplateArgs, Definition, New);
2290 
2291   return false;
2292 }
2293 
2294 /// \brief Initializes common fields of an instantiated method
2295 /// declaration (New) from the corresponding fields of its template
2296 /// (Tmpl).
2297 ///
2298 /// \returns true if there was an error
2299 bool
InitMethodInstantiation(CXXMethodDecl * New,CXXMethodDecl * Tmpl)2300 TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
2301                                                   CXXMethodDecl *Tmpl) {
2302   if (InitFunctionInstantiation(New, Tmpl))
2303     return true;
2304 
2305   New->setAccess(Tmpl->getAccess());
2306   if (Tmpl->isVirtualAsWritten())
2307     New->setVirtualAsWritten(true);
2308 
2309   // FIXME: attributes
2310   // FIXME: New needs a pointer to Tmpl
2311   return false;
2312 }
2313 
2314 /// \brief Instantiate the definition of the given function from its
2315 /// template.
2316 ///
2317 /// \param PointOfInstantiation the point at which the instantiation was
2318 /// required. Note that this is not precisely a "point of instantiation"
2319 /// for the function, but it's close.
2320 ///
2321 /// \param Function the already-instantiated declaration of a
2322 /// function template specialization or member function of a class template
2323 /// specialization.
2324 ///
2325 /// \param Recursive if true, recursively instantiates any functions that
2326 /// are required by this instantiation.
2327 ///
2328 /// \param DefinitionRequired if true, then we are performing an explicit
2329 /// instantiation where the body of the function is required. Complain if
2330 /// there is no such body.
InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,FunctionDecl * Function,bool Recursive,bool DefinitionRequired)2331 void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
2332                                          FunctionDecl *Function,
2333                                          bool Recursive,
2334                                          bool DefinitionRequired) {
2335   if (Function->isInvalidDecl() || Function->isDefined())
2336     return;
2337 
2338   // Never instantiate an explicit specialization.
2339   if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2340     return;
2341 
2342   // Find the function body that we'll be substituting.
2343   const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
2344   assert(PatternDecl && "instantiating a non-template");
2345 
2346   Stmt *Pattern = PatternDecl->getBody(PatternDecl);
2347   assert(PatternDecl && "template definition is not a template");
2348   if (!Pattern) {
2349     // Try to find a defaulted definition
2350     PatternDecl->isDefined(PatternDecl);
2351   }
2352   assert(PatternDecl && "template definition is not a template");
2353 
2354   // Postpone late parsed template instantiations.
2355   if (PatternDecl->isLateTemplateParsed() &&
2356       !LateTemplateParser) {
2357     PendingInstantiations.push_back(
2358       std::make_pair(Function, PointOfInstantiation));
2359     return;
2360   }
2361 
2362   // Call the LateTemplateParser callback if there a need to late parse
2363   // a templated function definition.
2364   if (!Pattern && PatternDecl->isLateTemplateParsed() &&
2365       LateTemplateParser) {
2366     LateTemplateParser(OpaqueParser, PatternDecl);
2367     Pattern = PatternDecl->getBody(PatternDecl);
2368   }
2369 
2370   if (!Pattern && !PatternDecl->isDefaulted()) {
2371     if (DefinitionRequired) {
2372       if (Function->getPrimaryTemplate())
2373         Diag(PointOfInstantiation,
2374              diag::err_explicit_instantiation_undefined_func_template)
2375           << Function->getPrimaryTemplate();
2376       else
2377         Diag(PointOfInstantiation,
2378              diag::err_explicit_instantiation_undefined_member)
2379           << 1 << Function->getDeclName() << Function->getDeclContext();
2380 
2381       if (PatternDecl)
2382         Diag(PatternDecl->getLocation(),
2383              diag::note_explicit_instantiation_here);
2384       Function->setInvalidDecl();
2385     } else if (Function->getTemplateSpecializationKind()
2386                  == TSK_ExplicitInstantiationDefinition) {
2387       PendingInstantiations.push_back(
2388         std::make_pair(Function, PointOfInstantiation));
2389     }
2390 
2391     return;
2392   }
2393 
2394   // C++0x [temp.explicit]p9:
2395   //   Except for inline functions, other explicit instantiation declarations
2396   //   have the effect of suppressing the implicit instantiation of the entity
2397   //   to which they refer.
2398   if (Function->getTemplateSpecializationKind()
2399         == TSK_ExplicitInstantiationDeclaration &&
2400       !PatternDecl->isInlined())
2401     return;
2402 
2403   InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2404   if (Inst)
2405     return;
2406 
2407   // If we're performing recursive template instantiation, create our own
2408   // queue of pending implicit instantiations that we will instantiate later,
2409   // while we're still within our own instantiation context.
2410   llvm::SmallVector<VTableUse, 16> SavedVTableUses;
2411   std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2412   if (Recursive) {
2413     VTableUses.swap(SavedVTableUses);
2414     PendingInstantiations.swap(SavedPendingInstantiations);
2415   }
2416 
2417   EnterExpressionEvaluationContext EvalContext(*this,
2418                                                Sema::PotentiallyEvaluated);
2419   ActOnStartOfFunctionDef(0, Function);
2420 
2421   // Introduce a new scope where local variable instantiations will be
2422   // recorded, unless we're actually a member function within a local
2423   // class, in which case we need to merge our results with the parent
2424   // scope (of the enclosing function).
2425   bool MergeWithParentScope = false;
2426   if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2427     MergeWithParentScope = Rec->isLocalClass();
2428 
2429   LocalInstantiationScope Scope(*this, MergeWithParentScope);
2430 
2431   // Introduce the instantiated function parameters into the local
2432   // instantiation scope, and set the parameter names to those used
2433   // in the template.
2434   unsigned FParamIdx = 0;
2435   for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
2436     const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
2437     if (!PatternParam->isParameterPack()) {
2438       // Simple case: not a parameter pack.
2439       assert(FParamIdx < Function->getNumParams());
2440       ParmVarDecl *FunctionParam = Function->getParamDecl(I);
2441       FunctionParam->setDeclName(PatternParam->getDeclName());
2442       Scope.InstantiatedLocal(PatternParam, FunctionParam);
2443       ++FParamIdx;
2444       continue;
2445     }
2446 
2447     // Expand the parameter pack.
2448     Scope.MakeInstantiatedLocalArgPack(PatternParam);
2449     for (unsigned NumFParams = Function->getNumParams();
2450          FParamIdx < NumFParams;
2451          ++FParamIdx) {
2452       ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
2453       FunctionParam->setDeclName(PatternParam->getDeclName());
2454       Scope.InstantiatedLocalPackArg(PatternParam, FunctionParam);
2455     }
2456   }
2457 
2458   // Enter the scope of this instantiation. We don't use
2459   // PushDeclContext because we don't have a scope.
2460   Sema::ContextRAII savedContext(*this, Function);
2461 
2462   MultiLevelTemplateArgumentList TemplateArgs =
2463     getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
2464 
2465   if (PatternDecl->isDefaulted()) {
2466     ActOnFinishFunctionBody(Function, 0, /*IsInstantiation=*/true);
2467 
2468     SetDeclDefaulted(Function, PatternDecl->getLocation());
2469   } else {
2470     // If this is a constructor, instantiate the member initializers.
2471     if (const CXXConstructorDecl *Ctor =
2472           dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2473       InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2474                                  TemplateArgs);
2475     }
2476 
2477     // Instantiate the function body.
2478     StmtResult Body = SubstStmt(Pattern, TemplateArgs);
2479 
2480     if (Body.isInvalid())
2481       Function->setInvalidDecl();
2482 
2483     ActOnFinishFunctionBody(Function, Body.get(),
2484                             /*IsInstantiation=*/true);
2485   }
2486 
2487   PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2488 
2489   savedContext.pop();
2490 
2491   DeclGroupRef DG(Function);
2492   Consumer.HandleTopLevelDecl(DG);
2493 
2494   // This class may have local implicit instantiations that need to be
2495   // instantiation within this scope.
2496   PerformPendingInstantiations(/*LocalOnly=*/true);
2497   Scope.Exit();
2498 
2499   if (Recursive) {
2500     // Define any pending vtables.
2501     DefineUsedVTables();
2502 
2503     // Instantiate any pending implicit instantiations found during the
2504     // instantiation of this template.
2505     PerformPendingInstantiations();
2506 
2507     // Restore the set of pending vtables.
2508     assert(VTableUses.empty() &&
2509            "VTableUses should be empty before it is discarded.");
2510     VTableUses.swap(SavedVTableUses);
2511 
2512     // Restore the set of pending implicit instantiations.
2513     assert(PendingInstantiations.empty() &&
2514            "PendingInstantiations should be empty before it is discarded.");
2515     PendingInstantiations.swap(SavedPendingInstantiations);
2516   }
2517 }
2518 
2519 /// \brief Instantiate the definition of the given variable from its
2520 /// template.
2521 ///
2522 /// \param PointOfInstantiation the point at which the instantiation was
2523 /// required. Note that this is not precisely a "point of instantiation"
2524 /// for the function, but it's close.
2525 ///
2526 /// \param Var the already-instantiated declaration of a static member
2527 /// variable of a class template specialization.
2528 ///
2529 /// \param Recursive if true, recursively instantiates any functions that
2530 /// are required by this instantiation.
2531 ///
2532 /// \param DefinitionRequired if true, then we are performing an explicit
2533 /// instantiation where an out-of-line definition of the member variable
2534 /// is required. Complain if there is no such definition.
InstantiateStaticDataMemberDefinition(SourceLocation PointOfInstantiation,VarDecl * Var,bool Recursive,bool DefinitionRequired)2535 void Sema::InstantiateStaticDataMemberDefinition(
2536                                           SourceLocation PointOfInstantiation,
2537                                                  VarDecl *Var,
2538                                                  bool Recursive,
2539                                                  bool DefinitionRequired) {
2540   if (Var->isInvalidDecl())
2541     return;
2542 
2543   // Find the out-of-line definition of this static data member.
2544   VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2545   assert(Def && "This data member was not instantiated from a template?");
2546   assert(Def->isStaticDataMember() && "Not a static data member?");
2547   Def = Def->getOutOfLineDefinition();
2548 
2549   if (!Def) {
2550     // We did not find an out-of-line definition of this static data member,
2551     // so we won't perform any instantiation. Rather, we rely on the user to
2552     // instantiate this definition (or provide a specialization for it) in
2553     // another translation unit.
2554     if (DefinitionRequired) {
2555       Def = Var->getInstantiatedFromStaticDataMember();
2556       Diag(PointOfInstantiation,
2557            diag::err_explicit_instantiation_undefined_member)
2558         << 2 << Var->getDeclName() << Var->getDeclContext();
2559       Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2560     } else if (Var->getTemplateSpecializationKind()
2561                  == TSK_ExplicitInstantiationDefinition) {
2562       PendingInstantiations.push_back(
2563         std::make_pair(Var, PointOfInstantiation));
2564     }
2565 
2566     return;
2567   }
2568 
2569   // Never instantiate an explicit specialization.
2570   if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2571     return;
2572 
2573   // C++0x [temp.explicit]p9:
2574   //   Except for inline functions, other explicit instantiation declarations
2575   //   have the effect of suppressing the implicit instantiation of the entity
2576   //   to which they refer.
2577   if (Var->getTemplateSpecializationKind()
2578         == TSK_ExplicitInstantiationDeclaration)
2579     return;
2580 
2581   // If we already have a definition, we're done.
2582   if (Var->getDefinition())
2583     return;
2584 
2585   InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2586   if (Inst)
2587     return;
2588 
2589   // If we're performing recursive template instantiation, create our own
2590   // queue of pending implicit instantiations that we will instantiate later,
2591   // while we're still within our own instantiation context.
2592   llvm::SmallVector<VTableUse, 16> SavedVTableUses;
2593   std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2594   if (Recursive) {
2595     VTableUses.swap(SavedVTableUses);
2596     PendingInstantiations.swap(SavedPendingInstantiations);
2597   }
2598 
2599   // Enter the scope of this instantiation. We don't use
2600   // PushDeclContext because we don't have a scope.
2601   ContextRAII previousContext(*this, Var->getDeclContext());
2602 
2603   VarDecl *OldVar = Var;
2604   Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2605                                         getTemplateInstantiationArgs(Var)));
2606 
2607   previousContext.pop();
2608 
2609   if (Var) {
2610     MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2611     assert(MSInfo && "Missing member specialization information?");
2612     Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2613                                        MSInfo->getPointOfInstantiation());
2614     DeclGroupRef DG(Var);
2615     Consumer.HandleTopLevelDecl(DG);
2616   }
2617 
2618   if (Recursive) {
2619     // Define any newly required vtables.
2620     DefineUsedVTables();
2621 
2622     // Instantiate any pending implicit instantiations found during the
2623     // instantiation of this template.
2624     PerformPendingInstantiations();
2625 
2626     // Restore the set of pending vtables.
2627     assert(VTableUses.empty() &&
2628            "VTableUses should be empty before it is discarded, "
2629            "while instantiating static data member.");
2630     VTableUses.swap(SavedVTableUses);
2631 
2632     // Restore the set of pending implicit instantiations.
2633     assert(PendingInstantiations.empty() &&
2634            "PendingInstantiations should be empty before it is discarded, "
2635            "while instantiating static data member.");
2636     PendingInstantiations.swap(SavedPendingInstantiations);
2637   }
2638 }
2639 
2640 void
InstantiateMemInitializers(CXXConstructorDecl * New,const CXXConstructorDecl * Tmpl,const MultiLevelTemplateArgumentList & TemplateArgs)2641 Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2642                                  const CXXConstructorDecl *Tmpl,
2643                            const MultiLevelTemplateArgumentList &TemplateArgs) {
2644 
2645   llvm::SmallVector<MemInitTy*, 4> NewInits;
2646   bool AnyErrors = false;
2647 
2648   // Instantiate all the initializers.
2649   for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2650                                             InitsEnd = Tmpl->init_end();
2651        Inits != InitsEnd; ++Inits) {
2652     CXXCtorInitializer *Init = *Inits;
2653 
2654     // Only instantiate written initializers, let Sema re-construct implicit
2655     // ones.
2656     if (!Init->isWritten())
2657       continue;
2658 
2659     SourceLocation LParenLoc, RParenLoc;
2660     ASTOwningVector<Expr*> NewArgs(*this);
2661 
2662     SourceLocation EllipsisLoc;
2663 
2664     if (Init->isPackExpansion()) {
2665       // This is a pack expansion. We should expand it now.
2666       TypeLoc BaseTL = Init->getBaseClassInfo()->getTypeLoc();
2667       llvm::SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2668       collectUnexpandedParameterPacks(BaseTL, Unexpanded);
2669       bool ShouldExpand = false;
2670       bool RetainExpansion = false;
2671       llvm::Optional<unsigned> NumExpansions;
2672       if (CheckParameterPacksForExpansion(Init->getEllipsisLoc(),
2673                                           BaseTL.getSourceRange(),
2674                                           Unexpanded.data(),
2675                                           Unexpanded.size(),
2676                                           TemplateArgs, ShouldExpand,
2677                                           RetainExpansion,
2678                                           NumExpansions)) {
2679         AnyErrors = true;
2680         New->setInvalidDecl();
2681         continue;
2682       }
2683       assert(ShouldExpand && "Partial instantiation of base initializer?");
2684 
2685       // Loop over all of the arguments in the argument pack(s),
2686       for (unsigned I = 0; I != *NumExpansions; ++I) {
2687         Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, I);
2688 
2689         // Instantiate the initializer.
2690         if (InstantiateInitializer(Init->getInit(), TemplateArgs,
2691                                    LParenLoc, NewArgs, RParenLoc)) {
2692           AnyErrors = true;
2693           break;
2694         }
2695 
2696         // Instantiate the base type.
2697         TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2698                                               TemplateArgs,
2699                                               Init->getSourceLocation(),
2700                                               New->getDeclName());
2701         if (!BaseTInfo) {
2702           AnyErrors = true;
2703           break;
2704         }
2705 
2706         // Build the initializer.
2707         MemInitResult NewInit = BuildBaseInitializer(BaseTInfo->getType(),
2708                                                      BaseTInfo,
2709                                                      (Expr **)NewArgs.data(),
2710                                                      NewArgs.size(),
2711                                                      Init->getLParenLoc(),
2712                                                      Init->getRParenLoc(),
2713                                                      New->getParent(),
2714                                                      SourceLocation());
2715         if (NewInit.isInvalid()) {
2716           AnyErrors = true;
2717           break;
2718         }
2719 
2720         NewInits.push_back(NewInit.get());
2721         NewArgs.clear();
2722       }
2723 
2724       continue;
2725     }
2726 
2727     // Instantiate the initializer.
2728     if (InstantiateInitializer(Init->getInit(), TemplateArgs,
2729                                LParenLoc, NewArgs, RParenLoc)) {
2730       AnyErrors = true;
2731       continue;
2732     }
2733 
2734     MemInitResult NewInit;
2735     if (Init->isBaseInitializer()) {
2736       TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2737                                             TemplateArgs,
2738                                             Init->getSourceLocation(),
2739                                             New->getDeclName());
2740       if (!BaseTInfo) {
2741         AnyErrors = true;
2742         New->setInvalidDecl();
2743         continue;
2744       }
2745 
2746       NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2747                                      (Expr **)NewArgs.data(),
2748                                      NewArgs.size(),
2749                                      Init->getLParenLoc(),
2750                                      Init->getRParenLoc(),
2751                                      New->getParent(),
2752                                      EllipsisLoc);
2753     } else if (Init->isMemberInitializer()) {
2754       FieldDecl *Member = cast_or_null<FieldDecl>(FindInstantiatedDecl(
2755                                                      Init->getMemberLocation(),
2756                                                      Init->getMember(),
2757                                                      TemplateArgs));
2758       if (!Member) {
2759         AnyErrors = true;
2760         New->setInvalidDecl();
2761         continue;
2762       }
2763 
2764       NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2765                                        NewArgs.size(),
2766                                        Init->getSourceLocation(),
2767                                        Init->getLParenLoc(),
2768                                        Init->getRParenLoc());
2769     } else if (Init->isIndirectMemberInitializer()) {
2770       IndirectFieldDecl *IndirectMember =
2771          cast_or_null<IndirectFieldDecl>(FindInstantiatedDecl(
2772                                  Init->getMemberLocation(),
2773                                  Init->getIndirectMember(), TemplateArgs));
2774 
2775       if (!IndirectMember) {
2776         AnyErrors = true;
2777         New->setInvalidDecl();
2778         continue;
2779       }
2780 
2781       NewInit = BuildMemberInitializer(IndirectMember, (Expr **)NewArgs.data(),
2782                                        NewArgs.size(),
2783                                        Init->getSourceLocation(),
2784                                        Init->getLParenLoc(),
2785                                        Init->getRParenLoc());
2786     }
2787 
2788     if (NewInit.isInvalid()) {
2789       AnyErrors = true;
2790       New->setInvalidDecl();
2791     } else {
2792       // FIXME: It would be nice if ASTOwningVector had a release function.
2793       NewArgs.take();
2794 
2795       NewInits.push_back((MemInitTy *)NewInit.get());
2796     }
2797   }
2798 
2799   // Assign all the initializers to the new constructor.
2800   ActOnMemInitializers(New,
2801                        /*FIXME: ColonLoc */
2802                        SourceLocation(),
2803                        NewInits.data(), NewInits.size(),
2804                        AnyErrors);
2805 }
2806 
2807 // TODO: this could be templated if the various decl types used the
2808 // same method name.
isInstantiationOf(ClassTemplateDecl * Pattern,ClassTemplateDecl * Instance)2809 static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2810                               ClassTemplateDecl *Instance) {
2811   Pattern = Pattern->getCanonicalDecl();
2812 
2813   do {
2814     Instance = Instance->getCanonicalDecl();
2815     if (Pattern == Instance) return true;
2816     Instance = Instance->getInstantiatedFromMemberTemplate();
2817   } while (Instance);
2818 
2819   return false;
2820 }
2821 
isInstantiationOf(FunctionTemplateDecl * Pattern,FunctionTemplateDecl * Instance)2822 static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2823                               FunctionTemplateDecl *Instance) {
2824   Pattern = Pattern->getCanonicalDecl();
2825 
2826   do {
2827     Instance = Instance->getCanonicalDecl();
2828     if (Pattern == Instance) return true;
2829     Instance = Instance->getInstantiatedFromMemberTemplate();
2830   } while (Instance);
2831 
2832   return false;
2833 }
2834 
2835 static bool
isInstantiationOf(ClassTemplatePartialSpecializationDecl * Pattern,ClassTemplatePartialSpecializationDecl * Instance)2836 isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2837                   ClassTemplatePartialSpecializationDecl *Instance) {
2838   Pattern
2839     = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2840   do {
2841     Instance = cast<ClassTemplatePartialSpecializationDecl>(
2842                                                 Instance->getCanonicalDecl());
2843     if (Pattern == Instance)
2844       return true;
2845     Instance = Instance->getInstantiatedFromMember();
2846   } while (Instance);
2847 
2848   return false;
2849 }
2850 
isInstantiationOf(CXXRecordDecl * Pattern,CXXRecordDecl * Instance)2851 static bool isInstantiationOf(CXXRecordDecl *Pattern,
2852                               CXXRecordDecl *Instance) {
2853   Pattern = Pattern->getCanonicalDecl();
2854 
2855   do {
2856     Instance = Instance->getCanonicalDecl();
2857     if (Pattern == Instance) return true;
2858     Instance = Instance->getInstantiatedFromMemberClass();
2859   } while (Instance);
2860 
2861   return false;
2862 }
2863 
isInstantiationOf(FunctionDecl * Pattern,FunctionDecl * Instance)2864 static bool isInstantiationOf(FunctionDecl *Pattern,
2865                               FunctionDecl *Instance) {
2866   Pattern = Pattern->getCanonicalDecl();
2867 
2868   do {
2869     Instance = Instance->getCanonicalDecl();
2870     if (Pattern == Instance) return true;
2871     Instance = Instance->getInstantiatedFromMemberFunction();
2872   } while (Instance);
2873 
2874   return false;
2875 }
2876 
isInstantiationOf(EnumDecl * Pattern,EnumDecl * Instance)2877 static bool isInstantiationOf(EnumDecl *Pattern,
2878                               EnumDecl *Instance) {
2879   Pattern = Pattern->getCanonicalDecl();
2880 
2881   do {
2882     Instance = Instance->getCanonicalDecl();
2883     if (Pattern == Instance) return true;
2884     Instance = Instance->getInstantiatedFromMemberEnum();
2885   } while (Instance);
2886 
2887   return false;
2888 }
2889 
isInstantiationOf(UsingShadowDecl * Pattern,UsingShadowDecl * Instance,ASTContext & C)2890 static bool isInstantiationOf(UsingShadowDecl *Pattern,
2891                               UsingShadowDecl *Instance,
2892                               ASTContext &C) {
2893   return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2894 }
2895 
isInstantiationOf(UsingDecl * Pattern,UsingDecl * Instance,ASTContext & C)2896 static bool isInstantiationOf(UsingDecl *Pattern,
2897                               UsingDecl *Instance,
2898                               ASTContext &C) {
2899   return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2900 }
2901 
isInstantiationOf(UnresolvedUsingValueDecl * Pattern,UsingDecl * Instance,ASTContext & C)2902 static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2903                               UsingDecl *Instance,
2904                               ASTContext &C) {
2905   return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2906 }
2907 
isInstantiationOf(UnresolvedUsingTypenameDecl * Pattern,UsingDecl * Instance,ASTContext & C)2908 static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2909                               UsingDecl *Instance,
2910                               ASTContext &C) {
2911   return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2912 }
2913 
isInstantiationOfStaticDataMember(VarDecl * Pattern,VarDecl * Instance)2914 static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2915                                               VarDecl *Instance) {
2916   assert(Instance->isStaticDataMember());
2917 
2918   Pattern = Pattern->getCanonicalDecl();
2919 
2920   do {
2921     Instance = Instance->getCanonicalDecl();
2922     if (Pattern == Instance) return true;
2923     Instance = Instance->getInstantiatedFromStaticDataMember();
2924   } while (Instance);
2925 
2926   return false;
2927 }
2928 
2929 // Other is the prospective instantiation
2930 // D is the prospective pattern
isInstantiationOf(ASTContext & Ctx,NamedDecl * D,Decl * Other)2931 static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2932   if (D->getKind() != Other->getKind()) {
2933     if (UnresolvedUsingTypenameDecl *UUD
2934           = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2935       if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2936         return isInstantiationOf(UUD, UD, Ctx);
2937       }
2938     }
2939 
2940     if (UnresolvedUsingValueDecl *UUD
2941           = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2942       if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2943         return isInstantiationOf(UUD, UD, Ctx);
2944       }
2945     }
2946 
2947     return false;
2948   }
2949 
2950   if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2951     return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2952 
2953   if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2954     return isInstantiationOf(cast<FunctionDecl>(D), Function);
2955 
2956   if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2957     return isInstantiationOf(cast<EnumDecl>(D), Enum);
2958 
2959   if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2960     if (Var->isStaticDataMember())
2961       return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2962 
2963   if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2964     return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2965 
2966   if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2967     return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2968 
2969   if (ClassTemplatePartialSpecializationDecl *PartialSpec
2970         = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2971     return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2972                              PartialSpec);
2973 
2974   if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2975     if (!Field->getDeclName()) {
2976       // This is an unnamed field.
2977       return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2978         cast<FieldDecl>(D);
2979     }
2980   }
2981 
2982   if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2983     return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2984 
2985   if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2986     return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2987 
2988   return D->getDeclName() && isa<NamedDecl>(Other) &&
2989     D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2990 }
2991 
2992 template<typename ForwardIterator>
findInstantiationOf(ASTContext & Ctx,NamedDecl * D,ForwardIterator first,ForwardIterator last)2993 static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2994                                       NamedDecl *D,
2995                                       ForwardIterator first,
2996                                       ForwardIterator last) {
2997   for (; first != last; ++first)
2998     if (isInstantiationOf(Ctx, D, *first))
2999       return cast<NamedDecl>(*first);
3000 
3001   return 0;
3002 }
3003 
3004 /// \brief Finds the instantiation of the given declaration context
3005 /// within the current instantiation.
3006 ///
3007 /// \returns NULL if there was an error
FindInstantiatedContext(SourceLocation Loc,DeclContext * DC,const MultiLevelTemplateArgumentList & TemplateArgs)3008 DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
3009                           const MultiLevelTemplateArgumentList &TemplateArgs) {
3010   if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
3011     Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
3012     return cast_or_null<DeclContext>(ID);
3013   } else return DC;
3014 }
3015 
3016 /// \brief Find the instantiation of the given declaration within the
3017 /// current instantiation.
3018 ///
3019 /// This routine is intended to be used when \p D is a declaration
3020 /// referenced from within a template, that needs to mapped into the
3021 /// corresponding declaration within an instantiation. For example,
3022 /// given:
3023 ///
3024 /// \code
3025 /// template<typename T>
3026 /// struct X {
3027 ///   enum Kind {
3028 ///     KnownValue = sizeof(T)
3029 ///   };
3030 ///
3031 ///   bool getKind() const { return KnownValue; }
3032 /// };
3033 ///
3034 /// template struct X<int>;
3035 /// \endcode
3036 ///
3037 /// In the instantiation of X<int>::getKind(), we need to map the
3038 /// EnumConstantDecl for KnownValue (which refers to
3039 /// X<T>::<Kind>::KnownValue) to its instantiation
3040 /// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
3041 /// this mapping from within the instantiation of X<int>.
FindInstantiatedDecl(SourceLocation Loc,NamedDecl * D,const MultiLevelTemplateArgumentList & TemplateArgs)3042 NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
3043                           const MultiLevelTemplateArgumentList &TemplateArgs) {
3044   DeclContext *ParentDC = D->getDeclContext();
3045   if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
3046       isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
3047       (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext())) {
3048     // D is a local of some kind. Look into the map of local
3049     // declarations to their instantiations.
3050     typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
3051     llvm::PointerUnion<Decl *, DeclArgumentPack *> *Found
3052       = CurrentInstantiationScope->findInstantiationOf(D);
3053 
3054     if (Found) {
3055       if (Decl *FD = Found->dyn_cast<Decl *>())
3056         return cast<NamedDecl>(FD);
3057 
3058       unsigned PackIdx = ArgumentPackSubstitutionIndex;
3059       return cast<NamedDecl>((*Found->get<DeclArgumentPack *>())[PackIdx]);
3060     }
3061 
3062     // If we didn't find the decl, then we must have a label decl that hasn't
3063     // been found yet.  Lazily instantiate it and return it now.
3064     assert(isa<LabelDecl>(D));
3065 
3066     Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
3067     assert(Inst && "Failed to instantiate label??");
3068 
3069     CurrentInstantiationScope->InstantiatedLocal(D, Inst);
3070     return cast<LabelDecl>(Inst);
3071   }
3072 
3073   if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
3074     if (!Record->isDependentContext())
3075       return D;
3076 
3077     // If the RecordDecl is actually the injected-class-name or a
3078     // "templated" declaration for a class template, class template
3079     // partial specialization, or a member class of a class template,
3080     // substitute into the injected-class-name of the class template
3081     // or partial specialization to find the new DeclContext.
3082     QualType T;
3083     ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
3084 
3085     if (ClassTemplate) {
3086       T = ClassTemplate->getInjectedClassNameSpecialization();
3087     } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
3088                  = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
3089       ClassTemplate = PartialSpec->getSpecializedTemplate();
3090 
3091       // If we call SubstType with an InjectedClassNameType here we
3092       // can end up in an infinite loop.
3093       T = Context.getTypeDeclType(Record);
3094       assert(isa<InjectedClassNameType>(T) &&
3095              "type of partial specialization is not an InjectedClassNameType");
3096       T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
3097     }
3098 
3099     if (!T.isNull()) {
3100       // Substitute into the injected-class-name to get the type
3101       // corresponding to the instantiation we want, which may also be
3102       // the current instantiation (if we're in a template
3103       // definition). This substitution should never fail, since we
3104       // know we can instantiate the injected-class-name or we
3105       // wouldn't have gotten to the injected-class-name!
3106 
3107       // FIXME: Can we use the CurrentInstantiationScope to avoid this
3108       // extra instantiation in the common case?
3109       T = SubstType(T, TemplateArgs, Loc, DeclarationName());
3110       assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
3111 
3112       if (!T->isDependentType()) {
3113         assert(T->isRecordType() && "Instantiation must produce a record type");
3114         return T->getAs<RecordType>()->getDecl();
3115       }
3116 
3117       // We are performing "partial" template instantiation to create
3118       // the member declarations for the members of a class template
3119       // specialization. Therefore, D is actually referring to something
3120       // in the current instantiation. Look through the current
3121       // context, which contains actual instantiations, to find the
3122       // instantiation of the "current instantiation" that D refers
3123       // to.
3124       bool SawNonDependentContext = false;
3125       for (DeclContext *DC = CurContext; !DC->isFileContext();
3126            DC = DC->getParent()) {
3127         if (ClassTemplateSpecializationDecl *Spec
3128                           = dyn_cast<ClassTemplateSpecializationDecl>(DC))
3129           if (isInstantiationOf(ClassTemplate,
3130                                 Spec->getSpecializedTemplate()))
3131             return Spec;
3132 
3133         if (!DC->isDependentContext())
3134           SawNonDependentContext = true;
3135       }
3136 
3137       // We're performing "instantiation" of a member of the current
3138       // instantiation while we are type-checking the
3139       // definition. Compute the declaration context and return that.
3140       assert(!SawNonDependentContext &&
3141              "No dependent context while instantiating record");
3142       DeclContext *DC = computeDeclContext(T);
3143       assert(DC &&
3144              "Unable to find declaration for the current instantiation");
3145       return cast<CXXRecordDecl>(DC);
3146     }
3147 
3148     // Fall through to deal with other dependent record types (e.g.,
3149     // anonymous unions in class templates).
3150   }
3151 
3152   if (!ParentDC->isDependentContext())
3153     return D;
3154 
3155   ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
3156   if (!ParentDC)
3157     return 0;
3158 
3159   if (ParentDC != D->getDeclContext()) {
3160     // We performed some kind of instantiation in the parent context,
3161     // so now we need to look into the instantiated parent context to
3162     // find the instantiation of the declaration D.
3163 
3164     // If our context used to be dependent, we may need to instantiate
3165     // it before performing lookup into that context.
3166     bool IsBeingInstantiated = false;
3167     if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
3168       if (!Spec->isDependentContext()) {
3169         QualType T = Context.getTypeDeclType(Spec);
3170         const RecordType *Tag = T->getAs<RecordType>();
3171         assert(Tag && "type of non-dependent record is not a RecordType");
3172         if (Tag->isBeingDefined())
3173           IsBeingInstantiated = true;
3174         if (!Tag->isBeingDefined() &&
3175             RequireCompleteType(Loc, T, diag::err_incomplete_type))
3176           return 0;
3177 
3178         ParentDC = Tag->getDecl();
3179       }
3180     }
3181 
3182     NamedDecl *Result = 0;
3183     if (D->getDeclName()) {
3184       DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
3185       Result = findInstantiationOf(Context, D, Found.first, Found.second);
3186     } else {
3187       // Since we don't have a name for the entity we're looking for,
3188       // our only option is to walk through all of the declarations to
3189       // find that name. This will occur in a few cases:
3190       //
3191       //   - anonymous struct/union within a template
3192       //   - unnamed class/struct/union/enum within a template
3193       //
3194       // FIXME: Find a better way to find these instantiations!
3195       Result = findInstantiationOf(Context, D,
3196                                    ParentDC->decls_begin(),
3197                                    ParentDC->decls_end());
3198     }
3199 
3200     if (!Result) {
3201       if (isa<UsingShadowDecl>(D)) {
3202         // UsingShadowDecls can instantiate to nothing because of using hiding.
3203       } else if (Diags.hasErrorOccurred()) {
3204         // We've already complained about something, so most likely this
3205         // declaration failed to instantiate. There's no point in complaining
3206         // further, since this is normal in invalid code.
3207       } else if (IsBeingInstantiated) {
3208         // The class in which this member exists is currently being
3209         // instantiated, and we haven't gotten around to instantiating this
3210         // member yet. This can happen when the code uses forward declarations
3211         // of member classes, and introduces ordering dependencies via
3212         // template instantiation.
3213         Diag(Loc, diag::err_member_not_yet_instantiated)
3214           << D->getDeclName()
3215           << Context.getTypeDeclType(cast<CXXRecordDecl>(ParentDC));
3216         Diag(D->getLocation(), diag::note_non_instantiated_member_here);
3217       } else {
3218         // We should have found something, but didn't.
3219         llvm_unreachable("Unable to find instantiation of declaration!");
3220       }
3221     }
3222 
3223     D = Result;
3224   }
3225 
3226   return D;
3227 }
3228 
3229 /// \brief Performs template instantiation for all implicit template
3230 /// instantiations we have seen until this point.
PerformPendingInstantiations(bool LocalOnly)3231 void Sema::PerformPendingInstantiations(bool LocalOnly) {
3232   while (!PendingLocalImplicitInstantiations.empty() ||
3233          (!LocalOnly && !PendingInstantiations.empty())) {
3234     PendingImplicitInstantiation Inst;
3235 
3236     if (PendingLocalImplicitInstantiations.empty()) {
3237       Inst = PendingInstantiations.front();
3238       PendingInstantiations.pop_front();
3239     } else {
3240       Inst = PendingLocalImplicitInstantiations.front();
3241       PendingLocalImplicitInstantiations.pop_front();
3242     }
3243 
3244     // Instantiate function definitions
3245     if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
3246       PrettyDeclStackTraceEntry CrashInfo(*this, Function, SourceLocation(),
3247                                           "instantiating function definition");
3248       bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
3249                                 TSK_ExplicitInstantiationDefinition;
3250       InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true,
3251                                     DefinitionRequired);
3252       continue;
3253     }
3254 
3255     // Instantiate static data member definitions.
3256     VarDecl *Var = cast<VarDecl>(Inst.first);
3257     assert(Var->isStaticDataMember() && "Not a static data member?");
3258 
3259     // Don't try to instantiate declarations if the most recent redeclaration
3260     // is invalid.
3261     if (Var->getMostRecentDeclaration()->isInvalidDecl())
3262       continue;
3263 
3264     // Check if the most recent declaration has changed the specialization kind
3265     // and removed the need for implicit instantiation.
3266     switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
3267     case TSK_Undeclared:
3268       assert(false && "Cannot instantitiate an undeclared specialization.");
3269     case TSK_ExplicitInstantiationDeclaration:
3270     case TSK_ExplicitSpecialization:
3271       continue;  // No longer need to instantiate this type.
3272     case TSK_ExplicitInstantiationDefinition:
3273       // We only need an instantiation if the pending instantiation *is* the
3274       // explicit instantiation.
3275       if (Var != Var->getMostRecentDeclaration()) continue;
3276     case TSK_ImplicitInstantiation:
3277       break;
3278     }
3279 
3280     PrettyDeclStackTraceEntry CrashInfo(*this, Var, Var->getLocation(),
3281                                         "instantiating static data member "
3282                                         "definition");
3283 
3284     bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
3285                               TSK_ExplicitInstantiationDefinition;
3286     InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true,
3287                                           DefinitionRequired);
3288   }
3289 }
3290 
PerformDependentDiagnostics(const DeclContext * Pattern,const MultiLevelTemplateArgumentList & TemplateArgs)3291 void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
3292                        const MultiLevelTemplateArgumentList &TemplateArgs) {
3293   for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
3294          E = Pattern->ddiag_end(); I != E; ++I) {
3295     DependentDiagnostic *DD = *I;
3296 
3297     switch (DD->getKind()) {
3298     case DependentDiagnostic::Access:
3299       HandleDependentAccessCheck(*DD, TemplateArgs);
3300       break;
3301     }
3302   }
3303 }
3304