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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/AST/ASTConsumer.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/DeclTemplate.h"
16 #include "clang/AST/DeclVisitor.h"
17 #include "clang/AST/DependentDiagnostic.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/TypeLoc.h"
21 #include "clang/Lex/Preprocessor.h"
22 #include "clang/Sema/Lookup.h"
23 #include "clang/Sema/PrettyDeclStackTrace.h"
24 #include "clang/Sema/Template.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 // Include attribute instantiation code.
61 #include "clang/Sema/AttrTemplateInstantiate.inc"
62 
instantiateDependentAlignedAttr(Sema & S,const MultiLevelTemplateArgumentList & TemplateArgs,const AlignedAttr * Aligned,Decl * New,bool IsPackExpansion)63 static void instantiateDependentAlignedAttr(
64     Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
65     const AlignedAttr *Aligned, Decl *New, bool IsPackExpansion) {
66   if (Aligned->isAlignmentExpr()) {
67     // The alignment expression is a constant expression.
68     EnterExpressionEvaluationContext Unevaluated(S, Sema::ConstantEvaluated);
69     ExprResult Result = S.SubstExpr(Aligned->getAlignmentExpr(), TemplateArgs);
70     if (!Result.isInvalid())
71       S.AddAlignedAttr(Aligned->getLocation(), New, Result.takeAs<Expr>(),
72                        Aligned->getSpellingListIndex(), IsPackExpansion);
73   } else {
74     TypeSourceInfo *Result = S.SubstType(Aligned->getAlignmentType(),
75                                          TemplateArgs, Aligned->getLocation(),
76                                          DeclarationName());
77     if (Result)
78       S.AddAlignedAttr(Aligned->getLocation(), New, Result,
79                        Aligned->getSpellingListIndex(), IsPackExpansion);
80   }
81 }
82 
instantiateDependentAlignedAttr(Sema & S,const MultiLevelTemplateArgumentList & TemplateArgs,const AlignedAttr * Aligned,Decl * New)83 static void instantiateDependentAlignedAttr(
84     Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
85     const AlignedAttr *Aligned, Decl *New) {
86   if (!Aligned->isPackExpansion()) {
87     instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
88     return;
89   }
90 
91   SmallVector<UnexpandedParameterPack, 2> Unexpanded;
92   if (Aligned->isAlignmentExpr())
93     S.collectUnexpandedParameterPacks(Aligned->getAlignmentExpr(),
94                                       Unexpanded);
95   else
96     S.collectUnexpandedParameterPacks(Aligned->getAlignmentType()->getTypeLoc(),
97                                       Unexpanded);
98   assert(!Unexpanded.empty() && "Pack expansion without parameter packs?");
99 
100   // Determine whether we can expand this attribute pack yet.
101   bool Expand = true, RetainExpansion = false;
102   Optional<unsigned> NumExpansions;
103   // FIXME: Use the actual location of the ellipsis.
104   SourceLocation EllipsisLoc = Aligned->getLocation();
105   if (S.CheckParameterPacksForExpansion(EllipsisLoc, Aligned->getRange(),
106                                         Unexpanded, TemplateArgs, Expand,
107                                         RetainExpansion, NumExpansions))
108     return;
109 
110   if (!Expand) {
111     Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, -1);
112     instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, true);
113   } else {
114     for (unsigned I = 0; I != *NumExpansions; ++I) {
115       Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, I);
116       instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
117     }
118   }
119 }
120 
InstantiateAttrs(const MultiLevelTemplateArgumentList & TemplateArgs,const Decl * Tmpl,Decl * New,LateInstantiatedAttrVec * LateAttrs,LocalInstantiationScope * OuterMostScope)121 void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
122                             const Decl *Tmpl, Decl *New,
123                             LateInstantiatedAttrVec *LateAttrs,
124                             LocalInstantiationScope *OuterMostScope) {
125   for (AttrVec::const_iterator i = Tmpl->attr_begin(), e = Tmpl->attr_end();
126        i != e; ++i) {
127     const Attr *TmplAttr = *i;
128 
129     // FIXME: This should be generalized to more than just the AlignedAttr.
130     const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr);
131     if (Aligned && Aligned->isAlignmentDependent()) {
132       instantiateDependentAlignedAttr(*this, TemplateArgs, Aligned, New);
133       continue;
134     }
135 
136     assert(!TmplAttr->isPackExpansion());
137     if (TmplAttr->isLateParsed() && LateAttrs) {
138       // Late parsed attributes must be instantiated and attached after the
139       // enclosing class has been instantiated.  See Sema::InstantiateClass.
140       LocalInstantiationScope *Saved = 0;
141       if (CurrentInstantiationScope)
142         Saved = CurrentInstantiationScope->cloneScopes(OuterMostScope);
143       LateAttrs->push_back(LateInstantiatedAttribute(TmplAttr, Saved, New));
144     } else {
145       // Allow 'this' within late-parsed attributes.
146       NamedDecl *ND = dyn_cast<NamedDecl>(New);
147       CXXRecordDecl *ThisContext =
148           dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext());
149       CXXThisScopeRAII ThisScope(*this, ThisContext, /*TypeQuals*/0,
150                                  ND && ND->isCXXInstanceMember());
151 
152       Attr *NewAttr = sema::instantiateTemplateAttribute(TmplAttr, Context,
153                                                          *this, TemplateArgs);
154       if (NewAttr)
155         New->addAttr(NewAttr);
156     }
157   }
158 }
159 
160 Decl *
VisitTranslationUnitDecl(TranslationUnitDecl * D)161 TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
162   llvm_unreachable("Translation units cannot be instantiated");
163 }
164 
165 Decl *
VisitLabelDecl(LabelDecl * D)166 TemplateDeclInstantiator::VisitLabelDecl(LabelDecl *D) {
167   LabelDecl *Inst = LabelDecl::Create(SemaRef.Context, Owner, D->getLocation(),
168                                       D->getIdentifier());
169   Owner->addDecl(Inst);
170   return Inst;
171 }
172 
173 Decl *
VisitNamespaceDecl(NamespaceDecl * D)174 TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
175   llvm_unreachable("Namespaces cannot be instantiated");
176 }
177 
178 Decl *
VisitNamespaceAliasDecl(NamespaceAliasDecl * D)179 TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
180   NamespaceAliasDecl *Inst
181     = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
182                                  D->getNamespaceLoc(),
183                                  D->getAliasLoc(),
184                                  D->getIdentifier(),
185                                  D->getQualifierLoc(),
186                                  D->getTargetNameLoc(),
187                                  D->getNamespace());
188   Owner->addDecl(Inst);
189   return Inst;
190 }
191 
InstantiateTypedefNameDecl(TypedefNameDecl * D,bool IsTypeAlias)192 Decl *TemplateDeclInstantiator::InstantiateTypedefNameDecl(TypedefNameDecl *D,
193                                                            bool IsTypeAlias) {
194   bool Invalid = false;
195   TypeSourceInfo *DI = D->getTypeSourceInfo();
196   if (DI->getType()->isInstantiationDependentType() ||
197       DI->getType()->isVariablyModifiedType()) {
198     DI = SemaRef.SubstType(DI, TemplateArgs,
199                            D->getLocation(), D->getDeclName());
200     if (!DI) {
201       Invalid = true;
202       DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
203     }
204   } else {
205     SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
206   }
207 
208   // HACK: g++ has a bug where it gets the value kind of ?: wrong.
209   // libstdc++ relies upon this bug in its implementation of common_type.
210   // If we happen to be processing that implementation, fake up the g++ ?:
211   // semantics. See LWG issue 2141 for more information on the bug.
212   const DecltypeType *DT = DI->getType()->getAs<DecltypeType>();
213   CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext());
214   if (DT && RD && isa<ConditionalOperator>(DT->getUnderlyingExpr()) &&
215       DT->isReferenceType() &&
216       RD->getEnclosingNamespaceContext() == SemaRef.getStdNamespace() &&
217       RD->getIdentifier() && RD->getIdentifier()->isStr("common_type") &&
218       D->getIdentifier() && D->getIdentifier()->isStr("type") &&
219       SemaRef.getSourceManager().isInSystemHeader(D->getLocStart()))
220     // Fold it to the (non-reference) type which g++ would have produced.
221     DI = SemaRef.Context.getTrivialTypeSourceInfo(
222       DI->getType().getNonReferenceType());
223 
224   // Create the new typedef
225   TypedefNameDecl *Typedef;
226   if (IsTypeAlias)
227     Typedef = TypeAliasDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
228                                     D->getLocation(), D->getIdentifier(), DI);
229   else
230     Typedef = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
231                                   D->getLocation(), D->getIdentifier(), DI);
232   if (Invalid)
233     Typedef->setInvalidDecl();
234 
235   // If the old typedef was the name for linkage purposes of an anonymous
236   // tag decl, re-establish that relationship for the new typedef.
237   if (const TagType *oldTagType = D->getUnderlyingType()->getAs<TagType>()) {
238     TagDecl *oldTag = oldTagType->getDecl();
239     if (oldTag->getTypedefNameForAnonDecl() == D && !Invalid) {
240       TagDecl *newTag = DI->getType()->castAs<TagType>()->getDecl();
241       assert(!newTag->hasNameForLinkage());
242       newTag->setTypedefNameForAnonDecl(Typedef);
243     }
244   }
245 
246   if (TypedefNameDecl *Prev = D->getPreviousDecl()) {
247     NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
248                                                        TemplateArgs);
249     if (!InstPrev)
250       return 0;
251 
252     TypedefNameDecl *InstPrevTypedef = cast<TypedefNameDecl>(InstPrev);
253 
254     // If the typedef types are not identical, reject them.
255     SemaRef.isIncompatibleTypedef(InstPrevTypedef, Typedef);
256 
257     Typedef->setPreviousDeclaration(InstPrevTypedef);
258   }
259 
260   SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef);
261 
262   Typedef->setAccess(D->getAccess());
263 
264   return Typedef;
265 }
266 
VisitTypedefDecl(TypedefDecl * D)267 Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
268   Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/false);
269   Owner->addDecl(Typedef);
270   return Typedef;
271 }
272 
VisitTypeAliasDecl(TypeAliasDecl * D)273 Decl *TemplateDeclInstantiator::VisitTypeAliasDecl(TypeAliasDecl *D) {
274   Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/true);
275   Owner->addDecl(Typedef);
276   return Typedef;
277 }
278 
279 Decl *
VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl * D)280 TemplateDeclInstantiator::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
281   // Create a local instantiation scope for this type alias template, which
282   // will contain the instantiations of the template parameters.
283   LocalInstantiationScope Scope(SemaRef);
284 
285   TemplateParameterList *TempParams = D->getTemplateParameters();
286   TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
287   if (!InstParams)
288     return 0;
289 
290   TypeAliasDecl *Pattern = D->getTemplatedDecl();
291 
292   TypeAliasTemplateDecl *PrevAliasTemplate = 0;
293   if (Pattern->getPreviousDecl()) {
294     DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
295     if (!Found.empty()) {
296       PrevAliasTemplate = dyn_cast<TypeAliasTemplateDecl>(Found.front());
297     }
298   }
299 
300   TypeAliasDecl *AliasInst = cast_or_null<TypeAliasDecl>(
301     InstantiateTypedefNameDecl(Pattern, /*IsTypeAlias=*/true));
302   if (!AliasInst)
303     return 0;
304 
305   TypeAliasTemplateDecl *Inst
306     = TypeAliasTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
307                                     D->getDeclName(), InstParams, AliasInst);
308   if (PrevAliasTemplate)
309     Inst->setPreviousDeclaration(PrevAliasTemplate);
310 
311   Inst->setAccess(D->getAccess());
312 
313   if (!PrevAliasTemplate)
314     Inst->setInstantiatedFromMemberTemplate(D);
315 
316   Owner->addDecl(Inst);
317 
318   return Inst;
319 }
320 
321 // FIXME: Revise for static member templates.
VisitVarDecl(VarDecl * D)322 Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
323   return VisitVarDecl(D, /*ForVarTemplate=*/false);
324 }
325 
VisitVarDecl(VarDecl * D,bool ForVarTemplate)326 Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D, bool ForVarTemplate) {
327 
328   // If this is the variable for an anonymous struct or union,
329   // instantiate the anonymous struct/union type first.
330   if (const RecordType *RecordTy = D->getType()->getAs<RecordType>())
331     if (RecordTy->getDecl()->isAnonymousStructOrUnion())
332       if (!VisitCXXRecordDecl(cast<CXXRecordDecl>(RecordTy->getDecl())))
333         return 0;
334 
335   // Do substitution on the type of the declaration
336   TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
337                                          TemplateArgs,
338                                          D->getTypeSpecStartLoc(),
339                                          D->getDeclName());
340   if (!DI)
341     return 0;
342 
343   if (DI->getType()->isFunctionType()) {
344     SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
345       << D->isStaticDataMember() << DI->getType();
346     return 0;
347   }
348 
349   // Build the instantiated declaration.
350   VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner, D->getInnerLocStart(),
351                                  D->getLocation(), D->getIdentifier(),
352                                  DI->getType(), DI, D->getStorageClass());
353 
354   // In ARC, infer 'retaining' for variables of retainable type.
355   if (SemaRef.getLangOpts().ObjCAutoRefCount &&
356       SemaRef.inferObjCARCLifetime(Var))
357     Var->setInvalidDecl();
358 
359   // Substitute the nested name specifier, if any.
360   if (SubstQualifier(D, Var))
361     return 0;
362 
363   SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs,
364                                      StartingScope, ForVarTemplate);
365   return Var;
366 }
367 
VisitAccessSpecDecl(AccessSpecDecl * D)368 Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
369   AccessSpecDecl* AD
370     = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
371                              D->getAccessSpecifierLoc(), D->getColonLoc());
372   Owner->addHiddenDecl(AD);
373   return AD;
374 }
375 
VisitFieldDecl(FieldDecl * D)376 Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
377   bool Invalid = false;
378   TypeSourceInfo *DI = D->getTypeSourceInfo();
379   if (DI->getType()->isInstantiationDependentType() ||
380       DI->getType()->isVariablyModifiedType())  {
381     DI = SemaRef.SubstType(DI, TemplateArgs,
382                            D->getLocation(), D->getDeclName());
383     if (!DI) {
384       DI = D->getTypeSourceInfo();
385       Invalid = true;
386     } else if (DI->getType()->isFunctionType()) {
387       // C++ [temp.arg.type]p3:
388       //   If a declaration acquires a function type through a type
389       //   dependent on a template-parameter and this causes a
390       //   declaration that does not use the syntactic form of a
391       //   function declarator to have function type, the program is
392       //   ill-formed.
393       SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
394         << DI->getType();
395       Invalid = true;
396     }
397   } else {
398     SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
399   }
400 
401   Expr *BitWidth = D->getBitWidth();
402   if (Invalid)
403     BitWidth = 0;
404   else if (BitWidth) {
405     // The bit-width expression is a constant expression.
406     EnterExpressionEvaluationContext Unevaluated(SemaRef,
407                                                  Sema::ConstantEvaluated);
408 
409     ExprResult InstantiatedBitWidth
410       = SemaRef.SubstExpr(BitWidth, TemplateArgs);
411     if (InstantiatedBitWidth.isInvalid()) {
412       Invalid = true;
413       BitWidth = 0;
414     } else
415       BitWidth = InstantiatedBitWidth.takeAs<Expr>();
416   }
417 
418   FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
419                                             DI->getType(), DI,
420                                             cast<RecordDecl>(Owner),
421                                             D->getLocation(),
422                                             D->isMutable(),
423                                             BitWidth,
424                                             D->getInClassInitStyle(),
425                                             D->getInnerLocStart(),
426                                             D->getAccess(),
427                                             0);
428   if (!Field) {
429     cast<Decl>(Owner)->setInvalidDecl();
430     return 0;
431   }
432 
433   SemaRef.InstantiateAttrs(TemplateArgs, D, Field, LateAttrs, StartingScope);
434 
435   if (Field->hasAttrs())
436     SemaRef.CheckAlignasUnderalignment(Field);
437 
438   if (Invalid)
439     Field->setInvalidDecl();
440 
441   if (!Field->getDeclName()) {
442     // Keep track of where this decl came from.
443     SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
444   }
445   if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
446     if (Parent->isAnonymousStructOrUnion() &&
447         Parent->getRedeclContext()->isFunctionOrMethod())
448       SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
449   }
450 
451   Field->setImplicit(D->isImplicit());
452   Field->setAccess(D->getAccess());
453   Owner->addDecl(Field);
454 
455   return Field;
456 }
457 
VisitMSPropertyDecl(MSPropertyDecl * D)458 Decl *TemplateDeclInstantiator::VisitMSPropertyDecl(MSPropertyDecl *D) {
459   bool Invalid = false;
460   TypeSourceInfo *DI = D->getTypeSourceInfo();
461 
462   if (DI->getType()->isVariablyModifiedType()) {
463     SemaRef.Diag(D->getLocation(), diag::err_property_is_variably_modified)
464     << D->getName();
465     Invalid = true;
466   } else if (DI->getType()->isInstantiationDependentType())  {
467     DI = SemaRef.SubstType(DI, TemplateArgs,
468                            D->getLocation(), D->getDeclName());
469     if (!DI) {
470       DI = D->getTypeSourceInfo();
471       Invalid = true;
472     } else if (DI->getType()->isFunctionType()) {
473       // C++ [temp.arg.type]p3:
474       //   If a declaration acquires a function type through a type
475       //   dependent on a template-parameter and this causes a
476       //   declaration that does not use the syntactic form of a
477       //   function declarator to have function type, the program is
478       //   ill-formed.
479       SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
480       << DI->getType();
481       Invalid = true;
482     }
483   } else {
484     SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
485   }
486 
487   MSPropertyDecl *Property = new (SemaRef.Context)
488       MSPropertyDecl(Owner, D->getLocation(),
489                      D->getDeclName(), DI->getType(), DI,
490                      D->getLocStart(),
491                      D->getGetterId(), D->getSetterId());
492 
493   SemaRef.InstantiateAttrs(TemplateArgs, D, Property, LateAttrs,
494                            StartingScope);
495 
496   if (Invalid)
497     Property->setInvalidDecl();
498 
499   Property->setAccess(D->getAccess());
500   Owner->addDecl(Property);
501 
502   return Property;
503 }
504 
VisitIndirectFieldDecl(IndirectFieldDecl * D)505 Decl *TemplateDeclInstantiator::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
506   NamedDecl **NamedChain =
507     new (SemaRef.Context)NamedDecl*[D->getChainingSize()];
508 
509   int i = 0;
510   for (IndirectFieldDecl::chain_iterator PI =
511        D->chain_begin(), PE = D->chain_end();
512        PI != PE; ++PI) {
513     NamedDecl *Next = SemaRef.FindInstantiatedDecl(D->getLocation(), *PI,
514                                               TemplateArgs);
515     if (!Next)
516       return 0;
517 
518     NamedChain[i++] = Next;
519   }
520 
521   QualType T = cast<FieldDecl>(NamedChain[i-1])->getType();
522   IndirectFieldDecl* IndirectField
523     = IndirectFieldDecl::Create(SemaRef.Context, Owner, D->getLocation(),
524                                 D->getIdentifier(), T,
525                                 NamedChain, D->getChainingSize());
526 
527 
528   IndirectField->setImplicit(D->isImplicit());
529   IndirectField->setAccess(D->getAccess());
530   Owner->addDecl(IndirectField);
531   return IndirectField;
532 }
533 
VisitFriendDecl(FriendDecl * D)534 Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
535   // Handle friend type expressions by simply substituting template
536   // parameters into the pattern type and checking the result.
537   if (TypeSourceInfo *Ty = D->getFriendType()) {
538     TypeSourceInfo *InstTy;
539     // If this is an unsupported friend, don't bother substituting template
540     // arguments into it. The actual type referred to won't be used by any
541     // parts of Clang, and may not be valid for instantiating. Just use the
542     // same info for the instantiated friend.
543     if (D->isUnsupportedFriend()) {
544       InstTy = Ty;
545     } else {
546       InstTy = SemaRef.SubstType(Ty, TemplateArgs,
547                                  D->getLocation(), DeclarationName());
548     }
549     if (!InstTy)
550       return 0;
551 
552     FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getLocStart(),
553                                                  D->getFriendLoc(), InstTy);
554     if (!FD)
555       return 0;
556 
557     FD->setAccess(AS_public);
558     FD->setUnsupportedFriend(D->isUnsupportedFriend());
559     Owner->addDecl(FD);
560     return FD;
561   }
562 
563   NamedDecl *ND = D->getFriendDecl();
564   assert(ND && "friend decl must be a decl or a type!");
565 
566   // All of the Visit implementations for the various potential friend
567   // declarations have to be carefully written to work for friend
568   // objects, with the most important detail being that the target
569   // decl should almost certainly not be placed in Owner.
570   Decl *NewND = Visit(ND);
571   if (!NewND) return 0;
572 
573   FriendDecl *FD =
574     FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
575                        cast<NamedDecl>(NewND), D->getFriendLoc());
576   FD->setAccess(AS_public);
577   FD->setUnsupportedFriend(D->isUnsupportedFriend());
578   Owner->addDecl(FD);
579   return FD;
580 }
581 
VisitStaticAssertDecl(StaticAssertDecl * D)582 Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
583   Expr *AssertExpr = D->getAssertExpr();
584 
585   // The expression in a static assertion is a constant expression.
586   EnterExpressionEvaluationContext Unevaluated(SemaRef,
587                                                Sema::ConstantEvaluated);
588 
589   ExprResult InstantiatedAssertExpr
590     = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
591   if (InstantiatedAssertExpr.isInvalid())
592     return 0;
593 
594   return SemaRef.BuildStaticAssertDeclaration(D->getLocation(),
595                                               InstantiatedAssertExpr.get(),
596                                               D->getMessage(),
597                                               D->getRParenLoc(),
598                                               D->isFailed());
599 }
600 
VisitEnumDecl(EnumDecl * D)601 Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
602   EnumDecl *PrevDecl = 0;
603   if (D->getPreviousDecl()) {
604     NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
605                                                    D->getPreviousDecl(),
606                                                    TemplateArgs);
607     if (!Prev) return 0;
608     PrevDecl = cast<EnumDecl>(Prev);
609   }
610 
611   EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
612                                     D->getLocation(), D->getIdentifier(),
613                                     PrevDecl, D->isScoped(),
614                                     D->isScopedUsingClassTag(), D->isFixed());
615   if (D->isFixed()) {
616     if (TypeSourceInfo *TI = D->getIntegerTypeSourceInfo()) {
617       // If we have type source information for the underlying type, it means it
618       // has been explicitly set by the user. Perform substitution on it before
619       // moving on.
620       SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
621       TypeSourceInfo *NewTI = SemaRef.SubstType(TI, TemplateArgs, UnderlyingLoc,
622                                                 DeclarationName());
623       if (!NewTI || SemaRef.CheckEnumUnderlyingType(NewTI))
624         Enum->setIntegerType(SemaRef.Context.IntTy);
625       else
626         Enum->setIntegerTypeSourceInfo(NewTI);
627     } else {
628       assert(!D->getIntegerType()->isDependentType()
629              && "Dependent type without type source info");
630       Enum->setIntegerType(D->getIntegerType());
631     }
632   }
633 
634   SemaRef.InstantiateAttrs(TemplateArgs, D, Enum);
635 
636   Enum->setInstantiationOfMemberEnum(D, TSK_ImplicitInstantiation);
637   Enum->setAccess(D->getAccess());
638   if (SubstQualifier(D, Enum)) return 0;
639   Owner->addDecl(Enum);
640 
641   EnumDecl *Def = D->getDefinition();
642   if (Def && Def != D) {
643     // If this is an out-of-line definition of an enum member template, check
644     // that the underlying types match in the instantiation of both
645     // declarations.
646     if (TypeSourceInfo *TI = Def->getIntegerTypeSourceInfo()) {
647       SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
648       QualType DefnUnderlying =
649         SemaRef.SubstType(TI->getType(), TemplateArgs,
650                           UnderlyingLoc, DeclarationName());
651       SemaRef.CheckEnumRedeclaration(Def->getLocation(), Def->isScoped(),
652                                      DefnUnderlying, Enum);
653     }
654   }
655 
656   if (D->getDeclContext()->isFunctionOrMethod())
657     SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
658 
659   // C++11 [temp.inst]p1: The implicit instantiation of a class template
660   // specialization causes the implicit instantiation of the declarations, but
661   // not the definitions of scoped member enumerations.
662   // FIXME: There appears to be no wording for what happens for an enum defined
663   // within a block scope, but we treat that much like a member template. Only
664   // instantiate the definition when visiting the definition in that case, since
665   // we will visit all redeclarations.
666   if (!Enum->isScoped() && Def &&
667       (!D->getDeclContext()->isFunctionOrMethod() || D->isCompleteDefinition()))
668     InstantiateEnumDefinition(Enum, Def);
669 
670   return Enum;
671 }
672 
InstantiateEnumDefinition(EnumDecl * Enum,EnumDecl * Pattern)673 void TemplateDeclInstantiator::InstantiateEnumDefinition(
674     EnumDecl *Enum, EnumDecl *Pattern) {
675   Enum->startDefinition();
676 
677   // Update the location to refer to the definition.
678   Enum->setLocation(Pattern->getLocation());
679 
680   SmallVector<Decl*, 4> Enumerators;
681 
682   EnumConstantDecl *LastEnumConst = 0;
683   for (EnumDecl::enumerator_iterator EC = Pattern->enumerator_begin(),
684          ECEnd = Pattern->enumerator_end();
685        EC != ECEnd; ++EC) {
686     // The specified value for the enumerator.
687     ExprResult Value = SemaRef.Owned((Expr *)0);
688     if (Expr *UninstValue = EC->getInitExpr()) {
689       // The enumerator's value expression is a constant expression.
690       EnterExpressionEvaluationContext Unevaluated(SemaRef,
691                                                    Sema::ConstantEvaluated);
692 
693       Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
694     }
695 
696     // Drop the initial value and continue.
697     bool isInvalid = false;
698     if (Value.isInvalid()) {
699       Value = SemaRef.Owned((Expr *)0);
700       isInvalid = true;
701     }
702 
703     EnumConstantDecl *EnumConst
704       = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
705                                   EC->getLocation(), EC->getIdentifier(),
706                                   Value.get());
707 
708     if (isInvalid) {
709       if (EnumConst)
710         EnumConst->setInvalidDecl();
711       Enum->setInvalidDecl();
712     }
713 
714     if (EnumConst) {
715       SemaRef.InstantiateAttrs(TemplateArgs, *EC, EnumConst);
716 
717       EnumConst->setAccess(Enum->getAccess());
718       Enum->addDecl(EnumConst);
719       Enumerators.push_back(EnumConst);
720       LastEnumConst = EnumConst;
721 
722       if (Pattern->getDeclContext()->isFunctionOrMethod() &&
723           !Enum->isScoped()) {
724         // If the enumeration is within a function or method, record the enum
725         // constant as a local.
726         SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
727       }
728     }
729   }
730 
731   // FIXME: Fixup LBraceLoc
732   SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(),
733                         Enum->getRBraceLoc(), Enum,
734                         Enumerators,
735                         0, 0);
736 }
737 
VisitEnumConstantDecl(EnumConstantDecl * D)738 Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
739   llvm_unreachable("EnumConstantDecls can only occur within EnumDecls.");
740 }
741 
VisitClassTemplateDecl(ClassTemplateDecl * D)742 Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
743   bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
744 
745   // Create a local instantiation scope for this class template, which
746   // will contain the instantiations of the template parameters.
747   LocalInstantiationScope Scope(SemaRef);
748   TemplateParameterList *TempParams = D->getTemplateParameters();
749   TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
750   if (!InstParams)
751     return NULL;
752 
753   CXXRecordDecl *Pattern = D->getTemplatedDecl();
754 
755   // Instantiate the qualifier.  We have to do this first in case
756   // we're a friend declaration, because if we are then we need to put
757   // the new declaration in the appropriate context.
758   NestedNameSpecifierLoc QualifierLoc = Pattern->getQualifierLoc();
759   if (QualifierLoc) {
760     QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
761                                                        TemplateArgs);
762     if (!QualifierLoc)
763       return 0;
764   }
765 
766   CXXRecordDecl *PrevDecl = 0;
767   ClassTemplateDecl *PrevClassTemplate = 0;
768 
769   if (!isFriend && Pattern->getPreviousDecl()) {
770     DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
771     if (!Found.empty()) {
772       PrevClassTemplate = dyn_cast<ClassTemplateDecl>(Found.front());
773       if (PrevClassTemplate)
774         PrevDecl = PrevClassTemplate->getTemplatedDecl();
775     }
776   }
777 
778   // If this isn't a friend, then it's a member template, in which
779   // case we just want to build the instantiation in the
780   // specialization.  If it is a friend, we want to build it in
781   // the appropriate context.
782   DeclContext *DC = Owner;
783   if (isFriend) {
784     if (QualifierLoc) {
785       CXXScopeSpec SS;
786       SS.Adopt(QualifierLoc);
787       DC = SemaRef.computeDeclContext(SS);
788       if (!DC) return 0;
789     } else {
790       DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
791                                            Pattern->getDeclContext(),
792                                            TemplateArgs);
793     }
794 
795     // Look for a previous declaration of the template in the owning
796     // context.
797     LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
798                    Sema::LookupOrdinaryName, Sema::ForRedeclaration);
799     SemaRef.LookupQualifiedName(R, DC);
800 
801     if (R.isSingleResult()) {
802       PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
803       if (PrevClassTemplate)
804         PrevDecl = PrevClassTemplate->getTemplatedDecl();
805     }
806 
807     if (!PrevClassTemplate && QualifierLoc) {
808       SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
809         << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
810         << QualifierLoc.getSourceRange();
811       return 0;
812     }
813 
814     bool AdoptedPreviousTemplateParams = false;
815     if (PrevClassTemplate) {
816       bool Complain = true;
817 
818       // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
819       // template for struct std::tr1::__detail::_Map_base, where the
820       // template parameters of the friend declaration don't match the
821       // template parameters of the original declaration. In this one
822       // case, we don't complain about the ill-formed friend
823       // declaration.
824       if (isFriend && Pattern->getIdentifier() &&
825           Pattern->getIdentifier()->isStr("_Map_base") &&
826           DC->isNamespace() &&
827           cast<NamespaceDecl>(DC)->getIdentifier() &&
828           cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
829         DeclContext *DCParent = DC->getParent();
830         if (DCParent->isNamespace() &&
831             cast<NamespaceDecl>(DCParent)->getIdentifier() &&
832             cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
833           DeclContext *DCParent2 = DCParent->getParent();
834           if (DCParent2->isNamespace() &&
835               cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
836               cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
837               DCParent2->getParent()->isTranslationUnit())
838             Complain = false;
839         }
840       }
841 
842       TemplateParameterList *PrevParams
843         = PrevClassTemplate->getTemplateParameters();
844 
845       // Make sure the parameter lists match.
846       if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
847                                                   Complain,
848                                                   Sema::TPL_TemplateMatch)) {
849         if (Complain)
850           return 0;
851 
852         AdoptedPreviousTemplateParams = true;
853         InstParams = PrevParams;
854       }
855 
856       // Do some additional validation, then merge default arguments
857       // from the existing declarations.
858       if (!AdoptedPreviousTemplateParams &&
859           SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
860                                              Sema::TPC_ClassTemplate))
861         return 0;
862     }
863   }
864 
865   CXXRecordDecl *RecordInst
866     = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
867                             Pattern->getLocStart(), Pattern->getLocation(),
868                             Pattern->getIdentifier(), PrevDecl,
869                             /*DelayTypeCreation=*/true);
870 
871   if (QualifierLoc)
872     RecordInst->setQualifierInfo(QualifierLoc);
873 
874   ClassTemplateDecl *Inst
875     = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
876                                 D->getIdentifier(), InstParams, RecordInst,
877                                 PrevClassTemplate);
878   RecordInst->setDescribedClassTemplate(Inst);
879 
880   if (isFriend) {
881     if (PrevClassTemplate)
882       Inst->setAccess(PrevClassTemplate->getAccess());
883     else
884       Inst->setAccess(D->getAccess());
885 
886     Inst->setObjectOfFriendDecl();
887     // TODO: do we want to track the instantiation progeny of this
888     // friend target decl?
889   } else {
890     Inst->setAccess(D->getAccess());
891     if (!PrevClassTemplate)
892       Inst->setInstantiatedFromMemberTemplate(D);
893   }
894 
895   // Trigger creation of the type for the instantiation.
896   SemaRef.Context.getInjectedClassNameType(RecordInst,
897                                     Inst->getInjectedClassNameSpecialization());
898 
899   // Finish handling of friends.
900   if (isFriend) {
901     DC->makeDeclVisibleInContext(Inst);
902     Inst->setLexicalDeclContext(Owner);
903     RecordInst->setLexicalDeclContext(Owner);
904     return Inst;
905   }
906 
907   if (D->isOutOfLine()) {
908     Inst->setLexicalDeclContext(D->getLexicalDeclContext());
909     RecordInst->setLexicalDeclContext(D->getLexicalDeclContext());
910   }
911 
912   Owner->addDecl(Inst);
913 
914   if (!PrevClassTemplate) {
915     // Queue up any out-of-line partial specializations of this member
916     // class template; the client will force their instantiation once
917     // the enclosing class has been instantiated.
918     SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
919     D->getPartialSpecializations(PartialSpecs);
920     for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
921       if (PartialSpecs[I]->isOutOfLine())
922         OutOfLinePartialSpecs.push_back(std::make_pair(Inst, PartialSpecs[I]));
923   }
924 
925   return Inst;
926 }
927 
928 Decl *
VisitClassTemplatePartialSpecializationDecl(ClassTemplatePartialSpecializationDecl * D)929 TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
930                                    ClassTemplatePartialSpecializationDecl *D) {
931   ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
932 
933   // Lookup the already-instantiated declaration in the instantiation
934   // of the class template and return that.
935   DeclContext::lookup_result Found
936     = Owner->lookup(ClassTemplate->getDeclName());
937   if (Found.empty())
938     return 0;
939 
940   ClassTemplateDecl *InstClassTemplate
941     = dyn_cast<ClassTemplateDecl>(Found.front());
942   if (!InstClassTemplate)
943     return 0;
944 
945   if (ClassTemplatePartialSpecializationDecl *Result
946         = InstClassTemplate->findPartialSpecInstantiatedFromMember(D))
947     return Result;
948 
949   return InstantiateClassTemplatePartialSpecialization(InstClassTemplate, D);
950 }
951 
VisitVarTemplateDecl(VarTemplateDecl * D)952 Decl *TemplateDeclInstantiator::VisitVarTemplateDecl(VarTemplateDecl *D) {
953   assert(D->getTemplatedDecl()->isStaticDataMember() &&
954          "Only static data member templates are allowed.");
955   // FIXME: Also only when instantiating a class?
956 
957   // Create a local instantiation scope for this variable template, which
958   // will contain the instantiations of the template parameters.
959   LocalInstantiationScope Scope(SemaRef);
960   TemplateParameterList *TempParams = D->getTemplateParameters();
961   TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
962   if (!InstParams)
963     return NULL;
964 
965   VarDecl *Pattern = D->getTemplatedDecl();
966   VarTemplateDecl *PrevVarTemplate = 0;
967 
968   if (Pattern->getPreviousDecl()) {
969     DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
970     if (!Found.empty())
971       PrevVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
972   }
973 
974   // FIXME: This, and ForVarTemplate, is a hack that is probably unnecessary.
975   // We should use a simplified version of VisitVarDecl.
976   VarDecl *VarInst = cast_or_null<VarDecl>(VisitVarDecl(Pattern, /*ForVarTemplate=*/true));
977 
978   DeclContext *DC = Owner;
979 
980   /* FIXME: This should be handled in VisitVarDecl, as used to produce
981      VarInst above.
982   // Instantiate the qualifier.
983   NestedNameSpecifierLoc QualifierLoc = Pattern->getQualifierLoc();
984   if (QualifierLoc) {
985     QualifierLoc =
986         SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgs);
987     if (!QualifierLoc)
988       return 0;
989   }
990 
991   if (QualifierLoc)
992     VarInst->setQualifierInfo(QualifierLoc);
993   */
994 
995   VarTemplateDecl *Inst = VarTemplateDecl::Create(
996       SemaRef.Context, DC, D->getLocation(), D->getIdentifier(), InstParams,
997       VarInst, PrevVarTemplate);
998   VarInst->setDescribedVarTemplate(Inst);
999 
1000   Inst->setAccess(D->getAccess());
1001   if (!PrevVarTemplate)
1002     Inst->setInstantiatedFromMemberTemplate(D);
1003 
1004   if (D->isOutOfLine()) {
1005     Inst->setLexicalDeclContext(D->getLexicalDeclContext());
1006     VarInst->setLexicalDeclContext(D->getLexicalDeclContext());
1007   }
1008 
1009   Owner->addDecl(Inst);
1010 
1011   if (!PrevVarTemplate) {
1012     // Queue up any out-of-line partial specializations of this member
1013     // variable template; the client will force their instantiation once
1014     // the enclosing class has been instantiated.
1015     SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
1016     D->getPartialSpecializations(PartialSpecs);
1017     for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
1018       if (PartialSpecs[I]->isOutOfLine())
1019         OutOfLineVarPartialSpecs.push_back(
1020             std::make_pair(Inst, PartialSpecs[I]));
1021   }
1022 
1023   return Inst;
1024 }
1025 
VisitVarTemplatePartialSpecializationDecl(VarTemplatePartialSpecializationDecl * D)1026 Decl *TemplateDeclInstantiator::VisitVarTemplatePartialSpecializationDecl(
1027     VarTemplatePartialSpecializationDecl *D) {
1028   assert(D->isStaticDataMember() &&
1029          "Only static data member templates are allowed.");
1030   // FIXME: Also only when instantiating a class?
1031 
1032   VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
1033 
1034   // Lookup the already-instantiated declaration and return that.
1035   DeclContext::lookup_result Found = Owner->lookup(VarTemplate->getDeclName());
1036   assert(!Found.empty() && "Instantiation found nothing?");
1037 
1038   VarTemplateDecl *InstVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
1039   assert(InstVarTemplate && "Instantiation did not find a variable template?");
1040 
1041   if (VarTemplatePartialSpecializationDecl *Result =
1042           InstVarTemplate->findPartialSpecInstantiatedFromMember(D))
1043     return Result;
1044 
1045   return InstantiateVarTemplatePartialSpecialization(InstVarTemplate, D);
1046 }
1047 
1048 Decl *
VisitFunctionTemplateDecl(FunctionTemplateDecl * D)1049 TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1050   // Create a local instantiation scope for this function template, which
1051   // will contain the instantiations of the template parameters and then get
1052   // merged with the local instantiation scope for the function template
1053   // itself.
1054   LocalInstantiationScope Scope(SemaRef);
1055 
1056   TemplateParameterList *TempParams = D->getTemplateParameters();
1057   TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1058   if (!InstParams)
1059     return NULL;
1060 
1061   FunctionDecl *Instantiated = 0;
1062   if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
1063     Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
1064                                                                  InstParams));
1065   else
1066     Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
1067                                                           D->getTemplatedDecl(),
1068                                                                 InstParams));
1069 
1070   if (!Instantiated)
1071     return 0;
1072 
1073   // Link the instantiated function template declaration to the function
1074   // template from which it was instantiated.
1075   FunctionTemplateDecl *InstTemplate
1076     = Instantiated->getDescribedFunctionTemplate();
1077   InstTemplate->setAccess(D->getAccess());
1078   assert(InstTemplate &&
1079          "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
1080 
1081   bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
1082 
1083   // Link the instantiation back to the pattern *unless* this is a
1084   // non-definition friend declaration.
1085   if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
1086       !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
1087     InstTemplate->setInstantiatedFromMemberTemplate(D);
1088 
1089   // Make declarations visible in the appropriate context.
1090   if (!isFriend) {
1091     Owner->addDecl(InstTemplate);
1092   } else if (InstTemplate->getDeclContext()->isRecord() &&
1093              !D->getPreviousDecl()) {
1094     SemaRef.CheckFriendAccess(InstTemplate);
1095   }
1096 
1097   return InstTemplate;
1098 }
1099 
VisitCXXRecordDecl(CXXRecordDecl * D)1100 Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
1101   CXXRecordDecl *PrevDecl = 0;
1102   if (D->isInjectedClassName())
1103     PrevDecl = cast<CXXRecordDecl>(Owner);
1104   else if (D->getPreviousDecl()) {
1105     NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
1106                                                    D->getPreviousDecl(),
1107                                                    TemplateArgs);
1108     if (!Prev) return 0;
1109     PrevDecl = cast<CXXRecordDecl>(Prev);
1110   }
1111 
1112   CXXRecordDecl *Record
1113     = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
1114                             D->getLocStart(), D->getLocation(),
1115                             D->getIdentifier(), PrevDecl);
1116 
1117   // Substitute the nested name specifier, if any.
1118   if (SubstQualifier(D, Record))
1119     return 0;
1120 
1121   Record->setImplicit(D->isImplicit());
1122   // FIXME: Check against AS_none is an ugly hack to work around the issue that
1123   // the tag decls introduced by friend class declarations don't have an access
1124   // specifier. Remove once this area of the code gets sorted out.
1125   if (D->getAccess() != AS_none)
1126     Record->setAccess(D->getAccess());
1127   if (!D->isInjectedClassName())
1128     Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
1129 
1130   // If the original function was part of a friend declaration,
1131   // inherit its namespace state.
1132   if (D->getFriendObjectKind())
1133     Record->setObjectOfFriendDecl();
1134 
1135   // Make sure that anonymous structs and unions are recorded.
1136   if (D->isAnonymousStructOrUnion()) {
1137     Record->setAnonymousStructOrUnion(true);
1138     if (Record->getDeclContext()->getRedeclContext()->isFunctionOrMethod())
1139       SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
1140   }
1141 
1142   Owner->addDecl(Record);
1143   return Record;
1144 }
1145 
1146 /// \brief Adjust the given function type for an instantiation of the
1147 /// given declaration, to cope with modifications to the function's type that
1148 /// aren't reflected in the type-source information.
1149 ///
1150 /// \param D The declaration we're instantiating.
1151 /// \param TInfo The already-instantiated type.
adjustFunctionTypeForInstantiation(ASTContext & Context,FunctionDecl * D,TypeSourceInfo * TInfo)1152 static QualType adjustFunctionTypeForInstantiation(ASTContext &Context,
1153                                                    FunctionDecl *D,
1154                                                    TypeSourceInfo *TInfo) {
1155   const FunctionProtoType *OrigFunc
1156     = D->getType()->castAs<FunctionProtoType>();
1157   const FunctionProtoType *NewFunc
1158     = TInfo->getType()->castAs<FunctionProtoType>();
1159   if (OrigFunc->getExtInfo() == NewFunc->getExtInfo())
1160     return TInfo->getType();
1161 
1162   FunctionProtoType::ExtProtoInfo NewEPI = NewFunc->getExtProtoInfo();
1163   NewEPI.ExtInfo = OrigFunc->getExtInfo();
1164   return Context.getFunctionType(NewFunc->getResultType(),
1165                                  NewFunc->getArgTypes(), NewEPI);
1166 }
1167 
1168 /// Normal class members are of more specific types and therefore
1169 /// don't make it here.  This function serves two purposes:
1170 ///   1) instantiating function templates
1171 ///   2) substituting friend declarations
1172 /// FIXME: preserve function definitions in case #2
VisitFunctionDecl(FunctionDecl * D,TemplateParameterList * TemplateParams)1173 Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
1174                                        TemplateParameterList *TemplateParams) {
1175   // Check whether there is already a function template specialization for
1176   // this declaration.
1177   FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1178   if (FunctionTemplate && !TemplateParams) {
1179     ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1180 
1181     void *InsertPos = 0;
1182     FunctionDecl *SpecFunc
1183       = FunctionTemplate->findSpecialization(Innermost.begin(), Innermost.size(),
1184                                              InsertPos);
1185 
1186     // If we already have a function template specialization, return it.
1187     if (SpecFunc)
1188       return SpecFunc;
1189   }
1190 
1191   bool isFriend;
1192   if (FunctionTemplate)
1193     isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1194   else
1195     isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1196 
1197   bool MergeWithParentScope = (TemplateParams != 0) ||
1198     Owner->isFunctionOrMethod() ||
1199     !(isa<Decl>(Owner) &&
1200       cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1201   LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1202 
1203   SmallVector<ParmVarDecl *, 4> Params;
1204   TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1205   if (!TInfo)
1206     return 0;
1207   QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1208 
1209   NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1210   if (QualifierLoc) {
1211     QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1212                                                        TemplateArgs);
1213     if (!QualifierLoc)
1214       return 0;
1215   }
1216 
1217   // If we're instantiating a local function declaration, put the result
1218   // in the owner;  otherwise we need to find the instantiated context.
1219   DeclContext *DC;
1220   if (D->getDeclContext()->isFunctionOrMethod())
1221     DC = Owner;
1222   else if (isFriend && QualifierLoc) {
1223     CXXScopeSpec SS;
1224     SS.Adopt(QualifierLoc);
1225     DC = SemaRef.computeDeclContext(SS);
1226     if (!DC) return 0;
1227   } else {
1228     DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1229                                          TemplateArgs);
1230   }
1231 
1232   FunctionDecl *Function =
1233       FunctionDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
1234                            D->getNameInfo(), T, TInfo,
1235                            D->getCanonicalDecl()->getStorageClass(),
1236                            D->isInlineSpecified(), D->hasWrittenPrototype(),
1237                            D->isConstexpr());
1238   Function->setRangeEnd(D->getSourceRange().getEnd());
1239 
1240   if (D->isInlined())
1241     Function->setImplicitlyInline();
1242 
1243   if (QualifierLoc)
1244     Function->setQualifierInfo(QualifierLoc);
1245 
1246   DeclContext *LexicalDC = Owner;
1247   if (!isFriend && D->isOutOfLine()) {
1248     assert(D->getDeclContext()->isFileContext());
1249     LexicalDC = D->getDeclContext();
1250   }
1251 
1252   Function->setLexicalDeclContext(LexicalDC);
1253 
1254   // Attach the parameters
1255   for (unsigned P = 0; P < Params.size(); ++P)
1256     if (Params[P])
1257       Params[P]->setOwningFunction(Function);
1258   Function->setParams(Params);
1259 
1260   SourceLocation InstantiateAtPOI;
1261   if (TemplateParams) {
1262     // Our resulting instantiation is actually a function template, since we
1263     // are substituting only the outer template parameters. For example, given
1264     //
1265     //   template<typename T>
1266     //   struct X {
1267     //     template<typename U> friend void f(T, U);
1268     //   };
1269     //
1270     //   X<int> x;
1271     //
1272     // We are instantiating the friend function template "f" within X<int>,
1273     // which means substituting int for T, but leaving "f" as a friend function
1274     // template.
1275     // Build the function template itself.
1276     FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1277                                                     Function->getLocation(),
1278                                                     Function->getDeclName(),
1279                                                     TemplateParams, Function);
1280     Function->setDescribedFunctionTemplate(FunctionTemplate);
1281 
1282     FunctionTemplate->setLexicalDeclContext(LexicalDC);
1283 
1284     if (isFriend && D->isThisDeclarationADefinition()) {
1285       // TODO: should we remember this connection regardless of whether
1286       // the friend declaration provided a body?
1287       FunctionTemplate->setInstantiatedFromMemberTemplate(
1288                                            D->getDescribedFunctionTemplate());
1289     }
1290   } else if (FunctionTemplate) {
1291     // Record this function template specialization.
1292     ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1293     Function->setFunctionTemplateSpecialization(FunctionTemplate,
1294                             TemplateArgumentList::CreateCopy(SemaRef.Context,
1295                                                              Innermost.begin(),
1296                                                              Innermost.size()),
1297                                                 /*InsertPos=*/0);
1298   } else if (isFriend) {
1299     // Note, we need this connection even if the friend doesn't have a body.
1300     // Its body may exist but not have been attached yet due to deferred
1301     // parsing.
1302     // FIXME: It might be cleaner to set this when attaching the body to the
1303     // friend function declaration, however that would require finding all the
1304     // instantiations and modifying them.
1305     Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1306   }
1307 
1308   if (InitFunctionInstantiation(Function, D))
1309     Function->setInvalidDecl();
1310 
1311   bool isExplicitSpecialization = false;
1312 
1313   LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1314                         Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1315 
1316   if (DependentFunctionTemplateSpecializationInfo *Info
1317         = D->getDependentSpecializationInfo()) {
1318     assert(isFriend && "non-friend has dependent specialization info?");
1319 
1320     // This needs to be set now for future sanity.
1321     Function->setObjectOfFriendDecl();
1322 
1323     // Instantiate the explicit template arguments.
1324     TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1325                                           Info->getRAngleLoc());
1326     if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(),
1327                       ExplicitArgs, TemplateArgs))
1328       return 0;
1329 
1330     // Map the candidate templates to their instantiations.
1331     for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1332       Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1333                                                 Info->getTemplate(I),
1334                                                 TemplateArgs);
1335       if (!Temp) return 0;
1336 
1337       Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1338     }
1339 
1340     if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1341                                                     &ExplicitArgs,
1342                                                     Previous))
1343       Function->setInvalidDecl();
1344 
1345     isExplicitSpecialization = true;
1346 
1347   } else if (TemplateParams || !FunctionTemplate) {
1348     // Look only into the namespace where the friend would be declared to
1349     // find a previous declaration. This is the innermost enclosing namespace,
1350     // as described in ActOnFriendFunctionDecl.
1351     SemaRef.LookupQualifiedName(Previous, DC);
1352 
1353     // In C++, the previous declaration we find might be a tag type
1354     // (class or enum). In this case, the new declaration will hide the
1355     // tag type. Note that this does does not apply if we're declaring a
1356     // typedef (C++ [dcl.typedef]p4).
1357     if (Previous.isSingleTagDecl())
1358       Previous.clear();
1359   }
1360 
1361   SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1362                                    isExplicitSpecialization);
1363 
1364   NamedDecl *PrincipalDecl = (TemplateParams
1365                               ? cast<NamedDecl>(FunctionTemplate)
1366                               : Function);
1367 
1368   // If the original function was part of a friend declaration,
1369   // inherit its namespace state and add it to the owner.
1370   if (isFriend) {
1371     PrincipalDecl->setObjectOfFriendDecl();
1372     DC->makeDeclVisibleInContext(PrincipalDecl);
1373 
1374     bool queuedInstantiation = false;
1375 
1376     // C++98 [temp.friend]p5: When a function is defined in a friend function
1377     //   declaration in a class template, the function is defined at each
1378     //   instantiation of the class template. The function is defined even if it
1379     //   is never used.
1380     // C++11 [temp.friend]p4: When a function is defined in a friend function
1381     //   declaration in a class template, the function is instantiated when the
1382     //   function is odr-used.
1383     //
1384     // If -Wc++98-compat is enabled, we go through the motions of checking for a
1385     // redefinition, but don't instantiate the function.
1386     if ((!SemaRef.getLangOpts().CPlusPlus11 ||
1387          SemaRef.Diags.getDiagnosticLevel(
1388              diag::warn_cxx98_compat_friend_redefinition,
1389              Function->getLocation())
1390            != DiagnosticsEngine::Ignored) &&
1391         D->isThisDeclarationADefinition()) {
1392       // Check for a function body.
1393       const FunctionDecl *Definition = 0;
1394       if (Function->isDefined(Definition) &&
1395           Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1396         SemaRef.Diag(Function->getLocation(),
1397                      SemaRef.getLangOpts().CPlusPlus11 ?
1398                        diag::warn_cxx98_compat_friend_redefinition :
1399                        diag::err_redefinition) << Function->getDeclName();
1400         SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1401         if (!SemaRef.getLangOpts().CPlusPlus11)
1402           Function->setInvalidDecl();
1403       }
1404       // Check for redefinitions due to other instantiations of this or
1405       // a similar friend function.
1406       else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1407                                            REnd = Function->redecls_end();
1408                 R != REnd; ++R) {
1409         if (*R == Function)
1410           continue;
1411         switch (R->getFriendObjectKind()) {
1412         case Decl::FOK_None:
1413           if (!SemaRef.getLangOpts().CPlusPlus11 &&
1414               !queuedInstantiation && R->isUsed(false)) {
1415             if (MemberSpecializationInfo *MSInfo
1416                 = Function->getMemberSpecializationInfo()) {
1417               if (MSInfo->getPointOfInstantiation().isInvalid()) {
1418                 SourceLocation Loc = R->getLocation(); // FIXME
1419                 MSInfo->setPointOfInstantiation(Loc);
1420                 SemaRef.PendingLocalImplicitInstantiations.push_back(
1421                                                  std::make_pair(Function, Loc));
1422                 queuedInstantiation = true;
1423               }
1424             }
1425           }
1426           break;
1427         default:
1428           if (const FunctionDecl *RPattern
1429               = R->getTemplateInstantiationPattern())
1430             if (RPattern->isDefined(RPattern)) {
1431               SemaRef.Diag(Function->getLocation(),
1432                            SemaRef.getLangOpts().CPlusPlus11 ?
1433                              diag::warn_cxx98_compat_friend_redefinition :
1434                              diag::err_redefinition)
1435                 << Function->getDeclName();
1436               SemaRef.Diag(R->getLocation(), diag::note_previous_definition);
1437               if (!SemaRef.getLangOpts().CPlusPlus11)
1438                 Function->setInvalidDecl();
1439               break;
1440             }
1441         }
1442       }
1443     }
1444   }
1445 
1446   if (Function->isOverloadedOperator() && !DC->isRecord() &&
1447       PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1448     PrincipalDecl->setNonMemberOperator();
1449 
1450   assert(!D->isDefaulted() && "only methods should be defaulted");
1451   return Function;
1452 }
1453 
1454 Decl *
VisitCXXMethodDecl(CXXMethodDecl * D,TemplateParameterList * TemplateParams,bool IsClassScopeSpecialization)1455 TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1456                                       TemplateParameterList *TemplateParams,
1457                                       bool IsClassScopeSpecialization) {
1458   FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1459   if (FunctionTemplate && !TemplateParams) {
1460     // We are creating a function template specialization from a function
1461     // template. Check whether there is already a function template
1462     // specialization for this particular set of template arguments.
1463     ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1464 
1465     void *InsertPos = 0;
1466     FunctionDecl *SpecFunc
1467       = FunctionTemplate->findSpecialization(Innermost.begin(),
1468                                              Innermost.size(),
1469                                              InsertPos);
1470 
1471     // If we already have a function template specialization, return it.
1472     if (SpecFunc)
1473       return SpecFunc;
1474   }
1475 
1476   bool isFriend;
1477   if (FunctionTemplate)
1478     isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1479   else
1480     isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1481 
1482   bool MergeWithParentScope = (TemplateParams != 0) ||
1483     !(isa<Decl>(Owner) &&
1484       cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1485   LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1486 
1487   // Instantiate enclosing template arguments for friends.
1488   SmallVector<TemplateParameterList *, 4> TempParamLists;
1489   unsigned NumTempParamLists = 0;
1490   if (isFriend && (NumTempParamLists = D->getNumTemplateParameterLists())) {
1491     TempParamLists.set_size(NumTempParamLists);
1492     for (unsigned I = 0; I != NumTempParamLists; ++I) {
1493       TemplateParameterList *TempParams = D->getTemplateParameterList(I);
1494       TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1495       if (!InstParams)
1496         return NULL;
1497       TempParamLists[I] = InstParams;
1498     }
1499   }
1500 
1501   SmallVector<ParmVarDecl *, 4> Params;
1502   TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1503   if (!TInfo)
1504     return 0;
1505   QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1506 
1507   NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1508   if (QualifierLoc) {
1509     QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1510                                                  TemplateArgs);
1511     if (!QualifierLoc)
1512       return 0;
1513   }
1514 
1515   DeclContext *DC = Owner;
1516   if (isFriend) {
1517     if (QualifierLoc) {
1518       CXXScopeSpec SS;
1519       SS.Adopt(QualifierLoc);
1520       DC = SemaRef.computeDeclContext(SS);
1521 
1522       if (DC && SemaRef.RequireCompleteDeclContext(SS, DC))
1523         return 0;
1524     } else {
1525       DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1526                                            D->getDeclContext(),
1527                                            TemplateArgs);
1528     }
1529     if (!DC) return 0;
1530   }
1531 
1532   // Build the instantiated method declaration.
1533   CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1534   CXXMethodDecl *Method = 0;
1535 
1536   SourceLocation StartLoc = D->getInnerLocStart();
1537   DeclarationNameInfo NameInfo
1538     = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1539   if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1540     Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1541                                         StartLoc, NameInfo, T, TInfo,
1542                                         Constructor->isExplicit(),
1543                                         Constructor->isInlineSpecified(),
1544                                         false, Constructor->isConstexpr());
1545 
1546     // Claim that the instantiation of a constructor or constructor template
1547     // inherits the same constructor that the template does.
1548     if (CXXConstructorDecl *Inh = const_cast<CXXConstructorDecl *>(
1549             Constructor->getInheritedConstructor())) {
1550       // If we're instantiating a specialization of a function template, our
1551       // "inherited constructor" will actually itself be a function template.
1552       // Instantiate a declaration of it, too.
1553       if (FunctionTemplate) {
1554         assert(!TemplateParams && Inh->getDescribedFunctionTemplate() &&
1555                !Inh->getParent()->isDependentContext() &&
1556                "inheriting constructor template in dependent context?");
1557         Sema::InstantiatingTemplate Inst(SemaRef, Constructor->getLocation(),
1558                                          Inh);
1559         if (Inst)
1560           return 0;
1561         Sema::ContextRAII SavedContext(SemaRef, Inh->getDeclContext());
1562         LocalInstantiationScope LocalScope(SemaRef);
1563 
1564         // Use the same template arguments that we deduced for the inheriting
1565         // constructor. There's no way they could be deduced differently.
1566         MultiLevelTemplateArgumentList InheritedArgs;
1567         InheritedArgs.addOuterTemplateArguments(TemplateArgs.getInnermost());
1568         Inh = cast_or_null<CXXConstructorDecl>(
1569             SemaRef.SubstDecl(Inh, Inh->getDeclContext(), InheritedArgs));
1570         if (!Inh)
1571           return 0;
1572       }
1573       cast<CXXConstructorDecl>(Method)->setInheritedConstructor(Inh);
1574     }
1575   } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1576     Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1577                                        StartLoc, NameInfo, T, TInfo,
1578                                        Destructor->isInlineSpecified(),
1579                                        false);
1580   } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1581     Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1582                                        StartLoc, NameInfo, T, TInfo,
1583                                        Conversion->isInlineSpecified(),
1584                                        Conversion->isExplicit(),
1585                                        Conversion->isConstexpr(),
1586                                        Conversion->getLocEnd());
1587   } else {
1588     StorageClass SC = D->isStatic() ? SC_Static : SC_None;
1589     Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1590                                    StartLoc, NameInfo, T, TInfo,
1591                                    SC, D->isInlineSpecified(),
1592                                    D->isConstexpr(), D->getLocEnd());
1593   }
1594 
1595   if (D->isInlined())
1596     Method->setImplicitlyInline();
1597 
1598   if (QualifierLoc)
1599     Method->setQualifierInfo(QualifierLoc);
1600 
1601   if (TemplateParams) {
1602     // Our resulting instantiation is actually a function template, since we
1603     // are substituting only the outer template parameters. For example, given
1604     //
1605     //   template<typename T>
1606     //   struct X {
1607     //     template<typename U> void f(T, U);
1608     //   };
1609     //
1610     //   X<int> x;
1611     //
1612     // We are instantiating the member template "f" within X<int>, which means
1613     // substituting int for T, but leaving "f" as a member function template.
1614     // Build the function template itself.
1615     FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1616                                                     Method->getLocation(),
1617                                                     Method->getDeclName(),
1618                                                     TemplateParams, Method);
1619     if (isFriend) {
1620       FunctionTemplate->setLexicalDeclContext(Owner);
1621       FunctionTemplate->setObjectOfFriendDecl();
1622     } else if (D->isOutOfLine())
1623       FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1624     Method->setDescribedFunctionTemplate(FunctionTemplate);
1625   } else if (FunctionTemplate) {
1626     // Record this function template specialization.
1627     ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1628     Method->setFunctionTemplateSpecialization(FunctionTemplate,
1629                          TemplateArgumentList::CreateCopy(SemaRef.Context,
1630                                                           Innermost.begin(),
1631                                                           Innermost.size()),
1632                                               /*InsertPos=*/0);
1633   } else if (!isFriend) {
1634     // Record that this is an instantiation of a member function.
1635     Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1636   }
1637 
1638   // If we are instantiating a member function defined
1639   // out-of-line, the instantiation will have the same lexical
1640   // context (which will be a namespace scope) as the template.
1641   if (isFriend) {
1642     if (NumTempParamLists)
1643       Method->setTemplateParameterListsInfo(SemaRef.Context,
1644                                             NumTempParamLists,
1645                                             TempParamLists.data());
1646 
1647     Method->setLexicalDeclContext(Owner);
1648     Method->setObjectOfFriendDecl();
1649   } else if (D->isOutOfLine())
1650     Method->setLexicalDeclContext(D->getLexicalDeclContext());
1651 
1652   // Attach the parameters
1653   for (unsigned P = 0; P < Params.size(); ++P)
1654     Params[P]->setOwningFunction(Method);
1655   Method->setParams(Params);
1656 
1657   if (InitMethodInstantiation(Method, D))
1658     Method->setInvalidDecl();
1659 
1660   LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
1661                         Sema::ForRedeclaration);
1662 
1663   if (!FunctionTemplate || TemplateParams || isFriend) {
1664     SemaRef.LookupQualifiedName(Previous, Record);
1665 
1666     // In C++, the previous declaration we find might be a tag type
1667     // (class or enum). In this case, the new declaration will hide the
1668     // tag type. Note that this does does not apply if we're declaring a
1669     // typedef (C++ [dcl.typedef]p4).
1670     if (Previous.isSingleTagDecl())
1671       Previous.clear();
1672   }
1673 
1674   if (!IsClassScopeSpecialization)
1675     SemaRef.CheckFunctionDeclaration(0, Method, Previous, false);
1676 
1677   if (D->isPure())
1678     SemaRef.CheckPureMethod(Method, SourceRange());
1679 
1680   // Propagate access.  For a non-friend declaration, the access is
1681   // whatever we're propagating from.  For a friend, it should be the
1682   // previous declaration we just found.
1683   if (isFriend && Method->getPreviousDecl())
1684     Method->setAccess(Method->getPreviousDecl()->getAccess());
1685   else
1686     Method->setAccess(D->getAccess());
1687   if (FunctionTemplate)
1688     FunctionTemplate->setAccess(Method->getAccess());
1689 
1690   SemaRef.CheckOverrideControl(Method);
1691 
1692   // If a function is defined as defaulted or deleted, mark it as such now.
1693   if (D->isExplicitlyDefaulted())
1694     SemaRef.SetDeclDefaulted(Method, Method->getLocation());
1695   if (D->isDeletedAsWritten())
1696     SemaRef.SetDeclDeleted(Method, Method->getLocation());
1697 
1698   // If there's a function template, let our caller handle it.
1699   if (FunctionTemplate) {
1700     // do nothing
1701 
1702   // Don't hide a (potentially) valid declaration with an invalid one.
1703   } else if (Method->isInvalidDecl() && !Previous.empty()) {
1704     // do nothing
1705 
1706   // Otherwise, check access to friends and make them visible.
1707   } else if (isFriend) {
1708     // We only need to re-check access for methods which we didn't
1709     // manage to match during parsing.
1710     if (!D->getPreviousDecl())
1711       SemaRef.CheckFriendAccess(Method);
1712 
1713     Record->makeDeclVisibleInContext(Method);
1714 
1715   // Otherwise, add the declaration.  We don't need to do this for
1716   // class-scope specializations because we'll have matched them with
1717   // the appropriate template.
1718   } else if (!IsClassScopeSpecialization) {
1719     Owner->addDecl(Method);
1720   }
1721 
1722   return Method;
1723 }
1724 
VisitCXXConstructorDecl(CXXConstructorDecl * D)1725 Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1726   return VisitCXXMethodDecl(D);
1727 }
1728 
VisitCXXDestructorDecl(CXXDestructorDecl * D)1729 Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1730   return VisitCXXMethodDecl(D);
1731 }
1732 
VisitCXXConversionDecl(CXXConversionDecl * D)1733 Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1734   return VisitCXXMethodDecl(D);
1735 }
1736 
VisitParmVarDecl(ParmVarDecl * D)1737 Decl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1738   return SemaRef.SubstParmVarDecl(D, TemplateArgs, /*indexAdjustment*/ 0, None,
1739                                   /*ExpectParameterPack=*/ false);
1740 }
1741 
VisitTemplateTypeParmDecl(TemplateTypeParmDecl * D)1742 Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1743                                                     TemplateTypeParmDecl *D) {
1744   // TODO: don't always clone when decls are refcounted.
1745   assert(D->getTypeForDecl()->isTemplateTypeParmType());
1746 
1747   TemplateTypeParmDecl *Inst =
1748     TemplateTypeParmDecl::Create(SemaRef.Context, Owner,
1749                                  D->getLocStart(), D->getLocation(),
1750                                  D->getDepth() - TemplateArgs.getNumLevels(),
1751                                  D->getIndex(), D->getIdentifier(),
1752                                  D->wasDeclaredWithTypename(),
1753                                  D->isParameterPack());
1754   Inst->setAccess(AS_public);
1755 
1756   if (D->hasDefaultArgument())
1757     Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1758 
1759   // Introduce this template parameter's instantiation into the instantiation
1760   // scope.
1761   SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1762 
1763   return Inst;
1764 }
1765 
VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl * D)1766 Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1767                                                  NonTypeTemplateParmDecl *D) {
1768   // Substitute into the type of the non-type template parameter.
1769   TypeLoc TL = D->getTypeSourceInfo()->getTypeLoc();
1770   SmallVector<TypeSourceInfo *, 4> ExpandedParameterPackTypesAsWritten;
1771   SmallVector<QualType, 4> ExpandedParameterPackTypes;
1772   bool IsExpandedParameterPack = false;
1773   TypeSourceInfo *DI;
1774   QualType T;
1775   bool Invalid = false;
1776 
1777   if (D->isExpandedParameterPack()) {
1778     // The non-type template parameter pack is an already-expanded pack
1779     // expansion of types. Substitute into each of the expanded types.
1780     ExpandedParameterPackTypes.reserve(D->getNumExpansionTypes());
1781     ExpandedParameterPackTypesAsWritten.reserve(D->getNumExpansionTypes());
1782     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1783       TypeSourceInfo *NewDI =SemaRef.SubstType(D->getExpansionTypeSourceInfo(I),
1784                                                TemplateArgs,
1785                                                D->getLocation(),
1786                                                D->getDeclName());
1787       if (!NewDI)
1788         return 0;
1789 
1790       ExpandedParameterPackTypesAsWritten.push_back(NewDI);
1791       QualType NewT =SemaRef.CheckNonTypeTemplateParameterType(NewDI->getType(),
1792                                                               D->getLocation());
1793       if (NewT.isNull())
1794         return 0;
1795       ExpandedParameterPackTypes.push_back(NewT);
1796     }
1797 
1798     IsExpandedParameterPack = true;
1799     DI = D->getTypeSourceInfo();
1800     T = DI->getType();
1801   } else if (D->isPackExpansion()) {
1802     // The non-type template parameter pack's type is a pack expansion of types.
1803     // Determine whether we need to expand this parameter pack into separate
1804     // types.
1805     PackExpansionTypeLoc Expansion = TL.castAs<PackExpansionTypeLoc>();
1806     TypeLoc Pattern = Expansion.getPatternLoc();
1807     SmallVector<UnexpandedParameterPack, 2> Unexpanded;
1808     SemaRef.collectUnexpandedParameterPacks(Pattern, Unexpanded);
1809 
1810     // Determine whether the set of unexpanded parameter packs can and should
1811     // be expanded.
1812     bool Expand = true;
1813     bool RetainExpansion = false;
1814     Optional<unsigned> OrigNumExpansions
1815       = Expansion.getTypePtr()->getNumExpansions();
1816     Optional<unsigned> NumExpansions = OrigNumExpansions;
1817     if (SemaRef.CheckParameterPacksForExpansion(Expansion.getEllipsisLoc(),
1818                                                 Pattern.getSourceRange(),
1819                                                 Unexpanded,
1820                                                 TemplateArgs,
1821                                                 Expand, RetainExpansion,
1822                                                 NumExpansions))
1823       return 0;
1824 
1825     if (Expand) {
1826       for (unsigned I = 0; I != *NumExpansions; ++I) {
1827         Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
1828         TypeSourceInfo *NewDI = SemaRef.SubstType(Pattern, TemplateArgs,
1829                                                   D->getLocation(),
1830                                                   D->getDeclName());
1831         if (!NewDI)
1832           return 0;
1833 
1834         ExpandedParameterPackTypesAsWritten.push_back(NewDI);
1835         QualType NewT = SemaRef.CheckNonTypeTemplateParameterType(
1836                                                               NewDI->getType(),
1837                                                               D->getLocation());
1838         if (NewT.isNull())
1839           return 0;
1840         ExpandedParameterPackTypes.push_back(NewT);
1841       }
1842 
1843       // Note that we have an expanded parameter pack. The "type" of this
1844       // expanded parameter pack is the original expansion type, but callers
1845       // will end up using the expanded parameter pack types for type-checking.
1846       IsExpandedParameterPack = true;
1847       DI = D->getTypeSourceInfo();
1848       T = DI->getType();
1849     } else {
1850       // We cannot fully expand the pack expansion now, so substitute into the
1851       // pattern and create a new pack expansion type.
1852       Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
1853       TypeSourceInfo *NewPattern = SemaRef.SubstType(Pattern, TemplateArgs,
1854                                                      D->getLocation(),
1855                                                      D->getDeclName());
1856       if (!NewPattern)
1857         return 0;
1858 
1859       DI = SemaRef.CheckPackExpansion(NewPattern, Expansion.getEllipsisLoc(),
1860                                       NumExpansions);
1861       if (!DI)
1862         return 0;
1863 
1864       T = DI->getType();
1865     }
1866   } else {
1867     // Simple case: substitution into a parameter that is not a parameter pack.
1868     DI = SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
1869                            D->getLocation(), D->getDeclName());
1870     if (!DI)
1871       return 0;
1872 
1873     // Check that this type is acceptable for a non-type template parameter.
1874     T = SemaRef.CheckNonTypeTemplateParameterType(DI->getType(),
1875                                                   D->getLocation());
1876     if (T.isNull()) {
1877       T = SemaRef.Context.IntTy;
1878       Invalid = true;
1879     }
1880   }
1881 
1882   NonTypeTemplateParmDecl *Param;
1883   if (IsExpandedParameterPack)
1884     Param = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner,
1885                                             D->getInnerLocStart(),
1886                                             D->getLocation(),
1887                                     D->getDepth() - TemplateArgs.getNumLevels(),
1888                                             D->getPosition(),
1889                                             D->getIdentifier(), T,
1890                                             DI,
1891                                             ExpandedParameterPackTypes.data(),
1892                                             ExpandedParameterPackTypes.size(),
1893                                     ExpandedParameterPackTypesAsWritten.data());
1894   else
1895     Param = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner,
1896                                             D->getInnerLocStart(),
1897                                             D->getLocation(),
1898                                     D->getDepth() - TemplateArgs.getNumLevels(),
1899                                             D->getPosition(),
1900                                             D->getIdentifier(), T,
1901                                             D->isParameterPack(), DI);
1902 
1903   Param->setAccess(AS_public);
1904   if (Invalid)
1905     Param->setInvalidDecl();
1906 
1907   Param->setDefaultArgument(D->getDefaultArgument(), false);
1908 
1909   // Introduce this template parameter's instantiation into the instantiation
1910   // scope.
1911   SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1912   return Param;
1913 }
1914 
collectUnexpandedParameterPacks(Sema & S,TemplateParameterList * Params,SmallVectorImpl<UnexpandedParameterPack> & Unexpanded)1915 static void collectUnexpandedParameterPacks(
1916     Sema &S,
1917     TemplateParameterList *Params,
1918     SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) {
1919   for (TemplateParameterList::const_iterator I = Params->begin(),
1920                                              E = Params->end(); I != E; ++I) {
1921     if ((*I)->isTemplateParameterPack())
1922       continue;
1923     if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(*I))
1924       S.collectUnexpandedParameterPacks(NTTP->getTypeSourceInfo()->getTypeLoc(),
1925                                         Unexpanded);
1926     if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(*I))
1927       collectUnexpandedParameterPacks(S, TTP->getTemplateParameters(),
1928                                       Unexpanded);
1929   }
1930 }
1931 
1932 Decl *
VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl * D)1933 TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1934                                                   TemplateTemplateParmDecl *D) {
1935   // Instantiate the template parameter list of the template template parameter.
1936   TemplateParameterList *TempParams = D->getTemplateParameters();
1937   TemplateParameterList *InstParams;
1938   SmallVector<TemplateParameterList*, 8> ExpandedParams;
1939 
1940   bool IsExpandedParameterPack = false;
1941 
1942   if (D->isExpandedParameterPack()) {
1943     // The template template parameter pack is an already-expanded pack
1944     // expansion of template parameters. Substitute into each of the expanded
1945     // parameters.
1946     ExpandedParams.reserve(D->getNumExpansionTemplateParameters());
1947     for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
1948          I != N; ++I) {
1949       LocalInstantiationScope Scope(SemaRef);
1950       TemplateParameterList *Expansion =
1951         SubstTemplateParams(D->getExpansionTemplateParameters(I));
1952       if (!Expansion)
1953         return 0;
1954       ExpandedParams.push_back(Expansion);
1955     }
1956 
1957     IsExpandedParameterPack = true;
1958     InstParams = TempParams;
1959   } else if (D->isPackExpansion()) {
1960     // The template template parameter pack expands to a pack of template
1961     // template parameters. Determine whether we need to expand this parameter
1962     // pack into separate parameters.
1963     SmallVector<UnexpandedParameterPack, 2> Unexpanded;
1964     collectUnexpandedParameterPacks(SemaRef, D->getTemplateParameters(),
1965                                     Unexpanded);
1966 
1967     // Determine whether the set of unexpanded parameter packs can and should
1968     // be expanded.
1969     bool Expand = true;
1970     bool RetainExpansion = false;
1971     Optional<unsigned> NumExpansions;
1972     if (SemaRef.CheckParameterPacksForExpansion(D->getLocation(),
1973                                                 TempParams->getSourceRange(),
1974                                                 Unexpanded,
1975                                                 TemplateArgs,
1976                                                 Expand, RetainExpansion,
1977                                                 NumExpansions))
1978       return 0;
1979 
1980     if (Expand) {
1981       for (unsigned I = 0; I != *NumExpansions; ++I) {
1982         Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
1983         LocalInstantiationScope Scope(SemaRef);
1984         TemplateParameterList *Expansion = SubstTemplateParams(TempParams);
1985         if (!Expansion)
1986           return 0;
1987         ExpandedParams.push_back(Expansion);
1988       }
1989 
1990       // Note that we have an expanded parameter pack. The "type" of this
1991       // expanded parameter pack is the original expansion type, but callers
1992       // will end up using the expanded parameter pack types for type-checking.
1993       IsExpandedParameterPack = true;
1994       InstParams = TempParams;
1995     } else {
1996       // We cannot fully expand the pack expansion now, so just substitute
1997       // into the pattern.
1998       Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
1999 
2000       LocalInstantiationScope Scope(SemaRef);
2001       InstParams = SubstTemplateParams(TempParams);
2002       if (!InstParams)
2003         return 0;
2004     }
2005   } else {
2006     // Perform the actual substitution of template parameters within a new,
2007     // local instantiation scope.
2008     LocalInstantiationScope Scope(SemaRef);
2009     InstParams = SubstTemplateParams(TempParams);
2010     if (!InstParams)
2011       return 0;
2012   }
2013 
2014   // Build the template template parameter.
2015   TemplateTemplateParmDecl *Param;
2016   if (IsExpandedParameterPack)
2017     Param = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner,
2018                                              D->getLocation(),
2019                                    D->getDepth() - TemplateArgs.getNumLevels(),
2020                                              D->getPosition(),
2021                                              D->getIdentifier(), InstParams,
2022                                              ExpandedParams);
2023   else
2024     Param = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner,
2025                                              D->getLocation(),
2026                                    D->getDepth() - TemplateArgs.getNumLevels(),
2027                                              D->getPosition(),
2028                                              D->isParameterPack(),
2029                                              D->getIdentifier(), InstParams);
2030   Param->setDefaultArgument(D->getDefaultArgument(), false);
2031   Param->setAccess(AS_public);
2032 
2033   // Introduce this template parameter's instantiation into the instantiation
2034   // scope.
2035   SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
2036 
2037   return Param;
2038 }
2039 
VisitUsingDirectiveDecl(UsingDirectiveDecl * D)2040 Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
2041   // Using directives are never dependent (and never contain any types or
2042   // expressions), so they require no explicit instantiation work.
2043 
2044   UsingDirectiveDecl *Inst
2045     = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
2046                                  D->getNamespaceKeyLocation(),
2047                                  D->getQualifierLoc(),
2048                                  D->getIdentLocation(),
2049                                  D->getNominatedNamespace(),
2050                                  D->getCommonAncestor());
2051 
2052   // Add the using directive to its declaration context
2053   // only if this is not a function or method.
2054   if (!Owner->isFunctionOrMethod())
2055     Owner->addDecl(Inst);
2056 
2057   return Inst;
2058 }
2059 
VisitUsingDecl(UsingDecl * D)2060 Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
2061 
2062   // The nested name specifier may be dependent, for example
2063   //     template <typename T> struct t {
2064   //       struct s1 { T f1(); };
2065   //       struct s2 : s1 { using s1::f1; };
2066   //     };
2067   //     template struct t<int>;
2068   // Here, in using s1::f1, s1 refers to t<T>::s1;
2069   // we need to substitute for t<int>::s1.
2070   NestedNameSpecifierLoc QualifierLoc
2071     = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
2072                                           TemplateArgs);
2073   if (!QualifierLoc)
2074     return 0;
2075 
2076   // The name info is non-dependent, so no transformation
2077   // is required.
2078   DeclarationNameInfo NameInfo = D->getNameInfo();
2079 
2080   // We only need to do redeclaration lookups if we're in a class
2081   // scope (in fact, it's not really even possible in non-class
2082   // scopes).
2083   bool CheckRedeclaration = Owner->isRecord();
2084 
2085   LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
2086                     Sema::ForRedeclaration);
2087 
2088   UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
2089                                        D->getUsingLoc(),
2090                                        QualifierLoc,
2091                                        NameInfo,
2092                                        D->hasTypename());
2093 
2094   CXXScopeSpec SS;
2095   SS.Adopt(QualifierLoc);
2096   if (CheckRedeclaration) {
2097     Prev.setHideTags(false);
2098     SemaRef.LookupQualifiedName(Prev, Owner);
2099 
2100     // Check for invalid redeclarations.
2101     if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLoc(),
2102                                             D->hasTypename(), SS,
2103                                             D->getLocation(), Prev))
2104       NewUD->setInvalidDecl();
2105 
2106   }
2107 
2108   if (!NewUD->isInvalidDecl() &&
2109       SemaRef.CheckUsingDeclQualifier(D->getUsingLoc(), SS,
2110                                       D->getLocation()))
2111     NewUD->setInvalidDecl();
2112 
2113   SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
2114   NewUD->setAccess(D->getAccess());
2115   Owner->addDecl(NewUD);
2116 
2117   // Don't process the shadow decls for an invalid decl.
2118   if (NewUD->isInvalidDecl())
2119     return NewUD;
2120 
2121   if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName) {
2122     if (SemaRef.CheckInheritingConstructorUsingDecl(NewUD))
2123       NewUD->setInvalidDecl();
2124     return NewUD;
2125   }
2126 
2127   bool isFunctionScope = Owner->isFunctionOrMethod();
2128 
2129   // Process the shadow decls.
2130   for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
2131          I != E; ++I) {
2132     UsingShadowDecl *Shadow = *I;
2133     NamedDecl *InstTarget =
2134       cast_or_null<NamedDecl>(SemaRef.FindInstantiatedDecl(
2135                                                           Shadow->getLocation(),
2136                                                         Shadow->getTargetDecl(),
2137                                                            TemplateArgs));
2138     if (!InstTarget)
2139       return 0;
2140 
2141     if (CheckRedeclaration &&
2142         SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
2143       continue;
2144 
2145     UsingShadowDecl *InstShadow
2146       = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
2147     SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
2148 
2149     if (isFunctionScope)
2150       SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
2151   }
2152 
2153   return NewUD;
2154 }
2155 
VisitUsingShadowDecl(UsingShadowDecl * D)2156 Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
2157   // Ignore these;  we handle them in bulk when processing the UsingDecl.
2158   return 0;
2159 }
2160 
2161 Decl * TemplateDeclInstantiator
VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl * D)2162     ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
2163   NestedNameSpecifierLoc QualifierLoc
2164     = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
2165                                           TemplateArgs);
2166   if (!QualifierLoc)
2167     return 0;
2168 
2169   CXXScopeSpec SS;
2170   SS.Adopt(QualifierLoc);
2171 
2172   // Since NameInfo refers to a typename, it cannot be a C++ special name.
2173   // Hence, no transformation is required for it.
2174   DeclarationNameInfo NameInfo(D->getDeclName(), D->getLocation());
2175   NamedDecl *UD =
2176     SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
2177                                   D->getUsingLoc(), SS, NameInfo, 0,
2178                                   /*instantiation*/ true,
2179                                   /*typename*/ true, D->getTypenameLoc());
2180   if (UD)
2181     SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
2182 
2183   return UD;
2184 }
2185 
2186 Decl * TemplateDeclInstantiator
VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl * D)2187     ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
2188   NestedNameSpecifierLoc QualifierLoc
2189       = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(), TemplateArgs);
2190   if (!QualifierLoc)
2191     return 0;
2192 
2193   CXXScopeSpec SS;
2194   SS.Adopt(QualifierLoc);
2195 
2196   DeclarationNameInfo NameInfo
2197     = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
2198 
2199   NamedDecl *UD =
2200     SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
2201                                   D->getUsingLoc(), SS, NameInfo, 0,
2202                                   /*instantiation*/ true,
2203                                   /*typename*/ false, SourceLocation());
2204   if (UD)
2205     SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
2206 
2207   return UD;
2208 }
2209 
2210 
VisitClassScopeFunctionSpecializationDecl(ClassScopeFunctionSpecializationDecl * Decl)2211 Decl *TemplateDeclInstantiator::VisitClassScopeFunctionSpecializationDecl(
2212                                      ClassScopeFunctionSpecializationDecl *Decl) {
2213   CXXMethodDecl *OldFD = Decl->getSpecialization();
2214   CXXMethodDecl *NewFD = cast<CXXMethodDecl>(VisitCXXMethodDecl(OldFD,
2215                                                                 0, true));
2216 
2217   LookupResult Previous(SemaRef, NewFD->getNameInfo(), Sema::LookupOrdinaryName,
2218                         Sema::ForRedeclaration);
2219 
2220   TemplateArgumentListInfo TemplateArgs;
2221   TemplateArgumentListInfo* TemplateArgsPtr = 0;
2222   if (Decl->hasExplicitTemplateArgs()) {
2223     TemplateArgs = Decl->templateArgs();
2224     TemplateArgsPtr = &TemplateArgs;
2225   }
2226 
2227   SemaRef.LookupQualifiedName(Previous, SemaRef.CurContext);
2228   if (SemaRef.CheckFunctionTemplateSpecialization(NewFD, TemplateArgsPtr,
2229                                                   Previous)) {
2230     NewFD->setInvalidDecl();
2231     return NewFD;
2232   }
2233 
2234   // Associate the specialization with the pattern.
2235   FunctionDecl *Specialization = cast<FunctionDecl>(Previous.getFoundDecl());
2236   assert(Specialization && "Class scope Specialization is null");
2237   SemaRef.Context.setClassScopeSpecializationPattern(Specialization, OldFD);
2238 
2239   return NewFD;
2240 }
2241 
VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl * D)2242 Decl *TemplateDeclInstantiator::VisitOMPThreadPrivateDecl(
2243                                      OMPThreadPrivateDecl *D) {
2244   SmallVector<Expr *, 5> Vars;
2245   for (ArrayRef<Expr *>::iterator I = D->varlist_begin(),
2246                                   E = D->varlist_end();
2247        I != E; ++I) {
2248     Expr *Var = SemaRef.SubstExpr(*I, TemplateArgs).take();
2249     assert(isa<DeclRefExpr>(Var) && "threadprivate arg is not a DeclRefExpr");
2250     Vars.push_back(Var);
2251   }
2252 
2253   OMPThreadPrivateDecl *TD =
2254     SemaRef.CheckOMPThreadPrivateDecl(D->getLocation(), Vars);
2255 
2256   return TD;
2257 }
2258 
VisitFunctionDecl(FunctionDecl * D)2259 Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D) {
2260   return VisitFunctionDecl(D, 0);
2261 }
2262 
VisitCXXMethodDecl(CXXMethodDecl * D)2263 Decl *TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D) {
2264   return VisitCXXMethodDecl(D, 0);
2265 }
2266 
VisitRecordDecl(RecordDecl * D)2267 Decl *TemplateDeclInstantiator::VisitRecordDecl(RecordDecl *D) {
2268   llvm_unreachable("There are only CXXRecordDecls in C++");
2269 }
2270 
2271 Decl *
VisitClassTemplateSpecializationDecl(ClassTemplateSpecializationDecl * D)2272 TemplateDeclInstantiator::VisitClassTemplateSpecializationDecl(
2273     ClassTemplateSpecializationDecl *D) {
2274   llvm_unreachable("Only ClassTemplatePartialSpecializationDecls occur"
2275                    "inside templates");
2276 }
2277 
VisitVarTemplateSpecializationDecl(VarTemplateSpecializationDecl * D)2278 Decl *TemplateDeclInstantiator::VisitVarTemplateSpecializationDecl(
2279     VarTemplateSpecializationDecl *D) {
2280 
2281   TemplateArgumentListInfo VarTemplateArgsInfo;
2282   VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
2283   assert(VarTemplate &&
2284          "A template specialization without specialized template?");
2285 
2286   // Substitute the current template arguments.
2287   const TemplateArgumentListInfo &TemplateArgsInfo = D->getTemplateArgsInfo();
2288   VarTemplateArgsInfo.setLAngleLoc(TemplateArgsInfo.getLAngleLoc());
2289   VarTemplateArgsInfo.setRAngleLoc(TemplateArgsInfo.getRAngleLoc());
2290 
2291   if (SemaRef.Subst(TemplateArgsInfo.getArgumentArray(),
2292                     TemplateArgsInfo.size(), VarTemplateArgsInfo, TemplateArgs))
2293     return 0;
2294 
2295   // Check that the template argument list is well-formed for this template.
2296   SmallVector<TemplateArgument, 4> Converted;
2297   bool ExpansionIntoFixedList = false;
2298   if (SemaRef.CheckTemplateArgumentList(
2299           VarTemplate, VarTemplate->getLocStart(),
2300           const_cast<TemplateArgumentListInfo &>(VarTemplateArgsInfo), false,
2301           Converted, &ExpansionIntoFixedList))
2302     return 0;
2303 
2304   // Find the variable template specialization declaration that
2305   // corresponds to these arguments.
2306   void *InsertPos = 0;
2307   if (VarTemplateSpecializationDecl *VarSpec = VarTemplate->findSpecialization(
2308           Converted.data(), Converted.size(), InsertPos))
2309     // If we already have a variable template specialization, return it.
2310     return VarSpec;
2311 
2312   return VisitVarTemplateSpecializationDecl(VarTemplate, D, InsertPos,
2313                                             VarTemplateArgsInfo, Converted);
2314 }
2315 
VisitVarTemplateSpecializationDecl(VarTemplateDecl * VarTemplate,VarDecl * D,void * InsertPos,const TemplateArgumentListInfo & TemplateArgsInfo,SmallVectorImpl<TemplateArgument> & Converted)2316 Decl *TemplateDeclInstantiator::VisitVarTemplateSpecializationDecl(
2317     VarTemplateDecl *VarTemplate, VarDecl *D, void *InsertPos,
2318     const TemplateArgumentListInfo &TemplateArgsInfo,
2319     SmallVectorImpl<TemplateArgument> &Converted) {
2320 
2321   // If this is the variable for an anonymous struct or union,
2322   // instantiate the anonymous struct/union type first.
2323   if (const RecordType *RecordTy = D->getType()->getAs<RecordType>())
2324     if (RecordTy->getDecl()->isAnonymousStructOrUnion())
2325       if (!VisitCXXRecordDecl(cast<CXXRecordDecl>(RecordTy->getDecl())))
2326         return 0;
2327 
2328   // Do substitution on the type of the declaration
2329   TypeSourceInfo *DI =
2330       SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
2331                         D->getTypeSpecStartLoc(), D->getDeclName());
2332   if (!DI)
2333     return 0;
2334 
2335   if (DI->getType()->isFunctionType()) {
2336     SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
2337         << D->isStaticDataMember() << DI->getType();
2338     return 0;
2339   }
2340 
2341   // Build the instantiated declaration
2342   VarTemplateSpecializationDecl *Var = VarTemplateSpecializationDecl::Create(
2343       SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
2344       VarTemplate, DI->getType(), DI, D->getStorageClass(), Converted.data(),
2345       Converted.size());
2346   Var->setTemplateArgsInfo(TemplateArgsInfo);
2347   VarTemplate->AddSpecialization(Var, InsertPos);
2348 
2349   // Substitute the nested name specifier, if any.
2350   if (SubstQualifier(D, Var))
2351     return 0;
2352 
2353   SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs,
2354                                      StartingScope);
2355 
2356   return Var;
2357 }
2358 
VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl * D)2359 Decl *TemplateDeclInstantiator::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
2360   llvm_unreachable("@defs is not supported in Objective-C++");
2361 }
2362 
VisitFriendTemplateDecl(FriendTemplateDecl * D)2363 Decl *TemplateDeclInstantiator::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
2364   // FIXME: We need to be able to instantiate FriendTemplateDecls.
2365   unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
2366                                                DiagnosticsEngine::Error,
2367                                                "cannot instantiate %0 yet");
2368   SemaRef.Diag(D->getLocation(), DiagID)
2369     << D->getDeclKindName();
2370 
2371   return 0;
2372 }
2373 
VisitDecl(Decl * D)2374 Decl *TemplateDeclInstantiator::VisitDecl(Decl *D) {
2375   llvm_unreachable("Unexpected decl");
2376 }
2377 
SubstDecl(Decl * D,DeclContext * Owner,const MultiLevelTemplateArgumentList & TemplateArgs)2378 Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
2379                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2380   TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
2381   if (D->isInvalidDecl())
2382     return 0;
2383 
2384   return Instantiator.Visit(D);
2385 }
2386 
2387 /// \brief Instantiates a nested template parameter list in the current
2388 /// instantiation context.
2389 ///
2390 /// \param L The parameter list to instantiate
2391 ///
2392 /// \returns NULL if there was an error
2393 TemplateParameterList *
SubstTemplateParams(TemplateParameterList * L)2394 TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
2395   // Get errors for all the parameters before bailing out.
2396   bool Invalid = false;
2397 
2398   unsigned N = L->size();
2399   typedef SmallVector<NamedDecl *, 8> ParamVector;
2400   ParamVector Params;
2401   Params.reserve(N);
2402   for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
2403        PI != PE; ++PI) {
2404     NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
2405     Params.push_back(D);
2406     Invalid = Invalid || !D || D->isInvalidDecl();
2407   }
2408 
2409   // Clean up if we had an error.
2410   if (Invalid)
2411     return NULL;
2412 
2413   TemplateParameterList *InstL
2414     = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
2415                                     L->getLAngleLoc(), &Params.front(), N,
2416                                     L->getRAngleLoc());
2417   return InstL;
2418 }
2419 
2420 /// \brief Instantiate the declaration of a class template partial
2421 /// specialization.
2422 ///
2423 /// \param ClassTemplate the (instantiated) class template that is partially
2424 // specialized by the instantiation of \p PartialSpec.
2425 ///
2426 /// \param PartialSpec the (uninstantiated) class template partial
2427 /// specialization that we are instantiating.
2428 ///
2429 /// \returns The instantiated partial specialization, if successful; otherwise,
2430 /// NULL to indicate an error.
2431 ClassTemplatePartialSpecializationDecl *
InstantiateClassTemplatePartialSpecialization(ClassTemplateDecl * ClassTemplate,ClassTemplatePartialSpecializationDecl * PartialSpec)2432 TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
2433                                             ClassTemplateDecl *ClassTemplate,
2434                           ClassTemplatePartialSpecializationDecl *PartialSpec) {
2435   // Create a local instantiation scope for this class template partial
2436   // specialization, which will contain the instantiations of the template
2437   // parameters.
2438   LocalInstantiationScope Scope(SemaRef);
2439 
2440   // Substitute into the template parameters of the class template partial
2441   // specialization.
2442   TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
2443   TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
2444   if (!InstParams)
2445     return 0;
2446 
2447   // Substitute into the template arguments of the class template partial
2448   // specialization.
2449   TemplateArgumentListInfo InstTemplateArgs; // no angle locations
2450   if (SemaRef.Subst(PartialSpec->getTemplateArgsAsWritten(),
2451                     PartialSpec->getNumTemplateArgsAsWritten(),
2452                     InstTemplateArgs, TemplateArgs))
2453     return 0;
2454 
2455   // Check that the template argument list is well-formed for this
2456   // class template.
2457   SmallVector<TemplateArgument, 4> Converted;
2458   if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
2459                                         PartialSpec->getLocation(),
2460                                         InstTemplateArgs,
2461                                         false,
2462                                         Converted))
2463     return 0;
2464 
2465   // Figure out where to insert this class template partial specialization
2466   // in the member template's set of class template partial specializations.
2467   void *InsertPos = 0;
2468   ClassTemplateSpecializationDecl *PrevDecl
2469     = ClassTemplate->findPartialSpecialization(Converted.data(),
2470                                                Converted.size(), InsertPos);
2471 
2472   // Build the canonical type that describes the converted template
2473   // arguments of the class template partial specialization.
2474   QualType CanonType
2475     = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
2476                                                     Converted.data(),
2477                                                     Converted.size());
2478 
2479   // Build the fully-sugared type for this class template
2480   // specialization as the user wrote in the specialization
2481   // itself. This means that we'll pretty-print the type retrieved
2482   // from the specialization's declaration the way that the user
2483   // actually wrote the specialization, rather than formatting the
2484   // name based on the "canonical" representation used to store the
2485   // template arguments in the specialization.
2486   TypeSourceInfo *WrittenTy
2487     = SemaRef.Context.getTemplateSpecializationTypeInfo(
2488                                                     TemplateName(ClassTemplate),
2489                                                     PartialSpec->getLocation(),
2490                                                     InstTemplateArgs,
2491                                                     CanonType);
2492 
2493   if (PrevDecl) {
2494     // We've already seen a partial specialization with the same template
2495     // parameters and template arguments. This can happen, for example, when
2496     // substituting the outer template arguments ends up causing two
2497     // class template partial specializations of a member class template
2498     // to have identical forms, e.g.,
2499     //
2500     //   template<typename T, typename U>
2501     //   struct Outer {
2502     //     template<typename X, typename Y> struct Inner;
2503     //     template<typename Y> struct Inner<T, Y>;
2504     //     template<typename Y> struct Inner<U, Y>;
2505     //   };
2506     //
2507     //   Outer<int, int> outer; // error: the partial specializations of Inner
2508     //                          // have the same signature.
2509     SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
2510       << WrittenTy->getType();
2511     SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
2512       << SemaRef.Context.getTypeDeclType(PrevDecl);
2513     return 0;
2514   }
2515 
2516 
2517   // Create the class template partial specialization declaration.
2518   ClassTemplatePartialSpecializationDecl *InstPartialSpec
2519     = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
2520                                                      PartialSpec->getTagKind(),
2521                                                      Owner,
2522                                                      PartialSpec->getLocStart(),
2523                                                      PartialSpec->getLocation(),
2524                                                      InstParams,
2525                                                      ClassTemplate,
2526                                                      Converted.data(),
2527                                                      Converted.size(),
2528                                                      InstTemplateArgs,
2529                                                      CanonType,
2530                                                      0,
2531                              ClassTemplate->getNextPartialSpecSequenceNumber());
2532   // Substitute the nested name specifier, if any.
2533   if (SubstQualifier(PartialSpec, InstPartialSpec))
2534     return 0;
2535 
2536   InstPartialSpec->setInstantiatedFromMember(PartialSpec);
2537   InstPartialSpec->setTypeAsWritten(WrittenTy);
2538 
2539   // Add this partial specialization to the set of class template partial
2540   // specializations.
2541   ClassTemplate->AddPartialSpecialization(InstPartialSpec, /*InsertPos=*/0);
2542   return InstPartialSpec;
2543 }
2544 
2545 /// \brief Instantiate the declaration of a variable template partial
2546 /// specialization.
2547 ///
2548 /// \param VarTemplate the (instantiated) variable template that is partially
2549 /// specialized by the instantiation of \p PartialSpec.
2550 ///
2551 /// \param PartialSpec the (uninstantiated) variable template partial
2552 /// specialization that we are instantiating.
2553 ///
2554 /// \returns The instantiated partial specialization, if successful; otherwise,
2555 /// NULL to indicate an error.
2556 VarTemplatePartialSpecializationDecl *
InstantiateVarTemplatePartialSpecialization(VarTemplateDecl * VarTemplate,VarTemplatePartialSpecializationDecl * PartialSpec)2557 TemplateDeclInstantiator::InstantiateVarTemplatePartialSpecialization(
2558     VarTemplateDecl *VarTemplate,
2559     VarTemplatePartialSpecializationDecl *PartialSpec) {
2560   // Create a local instantiation scope for this variable template partial
2561   // specialization, which will contain the instantiations of the template
2562   // parameters.
2563   LocalInstantiationScope Scope(SemaRef);
2564 
2565   // Substitute into the template parameters of the variable template partial
2566   // specialization.
2567   TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
2568   TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
2569   if (!InstParams)
2570     return 0;
2571 
2572   // Substitute into the template arguments of the variable template partial
2573   // specialization.
2574   TemplateArgumentListInfo InstTemplateArgs; // no angle locations
2575   if (SemaRef.Subst(PartialSpec->getTemplateArgsAsWritten(),
2576                     PartialSpec->getNumTemplateArgsAsWritten(),
2577                     InstTemplateArgs, TemplateArgs))
2578     return 0;
2579 
2580   // Check that the template argument list is well-formed for this
2581   // class template.
2582   SmallVector<TemplateArgument, 4> Converted;
2583   if (SemaRef.CheckTemplateArgumentList(VarTemplate, PartialSpec->getLocation(),
2584                                         InstTemplateArgs, false, Converted))
2585     return 0;
2586 
2587   // Figure out where to insert this variable template partial specialization
2588   // in the member template's set of variable template partial specializations.
2589   void *InsertPos = 0;
2590   VarTemplateSpecializationDecl *PrevDecl =
2591       VarTemplate->findPartialSpecialization(Converted.data(), Converted.size(),
2592                                              InsertPos);
2593 
2594   // Build the canonical type that describes the converted template
2595   // arguments of the variable template partial specialization.
2596   QualType CanonType = SemaRef.Context.getTemplateSpecializationType(
2597       TemplateName(VarTemplate), Converted.data(), Converted.size());
2598 
2599   // Build the fully-sugared type for this variable template
2600   // specialization as the user wrote in the specialization
2601   // itself. This means that we'll pretty-print the type retrieved
2602   // from the specialization's declaration the way that the user
2603   // actually wrote the specialization, rather than formatting the
2604   // name based on the "canonical" representation used to store the
2605   // template arguments in the specialization.
2606   TypeSourceInfo *WrittenTy = SemaRef.Context.getTemplateSpecializationTypeInfo(
2607       TemplateName(VarTemplate), PartialSpec->getLocation(), InstTemplateArgs,
2608       CanonType);
2609 
2610   if (PrevDecl) {
2611     // We've already seen a partial specialization with the same template
2612     // parameters and template arguments. This can happen, for example, when
2613     // substituting the outer template arguments ends up causing two
2614     // variable template partial specializations of a member variable template
2615     // to have identical forms, e.g.,
2616     //
2617     //   template<typename T, typename U>
2618     //   struct Outer {
2619     //     template<typename X, typename Y> pair<X,Y> p;
2620     //     template<typename Y> pair<T, Y> p;
2621     //     template<typename Y> pair<U, Y> p;
2622     //   };
2623     //
2624     //   Outer<int, int> outer; // error: the partial specializations of Inner
2625     //                          // have the same signature.
2626     SemaRef.Diag(PartialSpec->getLocation(),
2627                  diag::err_var_partial_spec_redeclared)
2628         << WrittenTy->getType();
2629     SemaRef.Diag(PrevDecl->getLocation(),
2630                  diag::note_var_prev_partial_spec_here);
2631     return 0;
2632   }
2633 
2634   // Do substitution on the type of the declaration
2635   TypeSourceInfo *DI = SemaRef.SubstType(
2636       PartialSpec->getTypeSourceInfo(), TemplateArgs,
2637       PartialSpec->getTypeSpecStartLoc(), PartialSpec->getDeclName());
2638   if (!DI)
2639     return 0;
2640 
2641   if (DI->getType()->isFunctionType()) {
2642     SemaRef.Diag(PartialSpec->getLocation(),
2643                  diag::err_variable_instantiates_to_function)
2644         << PartialSpec->isStaticDataMember() << DI->getType();
2645     return 0;
2646   }
2647 
2648   // Create the variable template partial specialization declaration.
2649   VarTemplatePartialSpecializationDecl *InstPartialSpec =
2650       VarTemplatePartialSpecializationDecl::Create(
2651           SemaRef.Context, Owner, PartialSpec->getInnerLocStart(),
2652           PartialSpec->getLocation(), InstParams, VarTemplate, DI->getType(),
2653           DI, PartialSpec->getStorageClass(), Converted.data(),
2654           Converted.size(), InstTemplateArgs,
2655           VarTemplate->getNextPartialSpecSequenceNumber());
2656 
2657   // Substitute the nested name specifier, if any.
2658   if (SubstQualifier(PartialSpec, InstPartialSpec))
2659     return 0;
2660 
2661   InstPartialSpec->setInstantiatedFromMember(PartialSpec);
2662   InstPartialSpec->setTypeAsWritten(WrittenTy);
2663 
2664   InstPartialSpec->setAccess(PartialSpec->getAccess());
2665   // FIXME: How much of BuildVariableInstantiation() should go in here?
2666 
2667   // Add this partial specialization to the set of variable template partial
2668   // specializations. The instantiation of the initializer is not necessary.
2669   VarTemplate->AddPartialSpecialization(InstPartialSpec, /*InsertPos=*/0);
2670   return InstPartialSpec;
2671 }
2672 
2673 TypeSourceInfo*
SubstFunctionType(FunctionDecl * D,SmallVectorImpl<ParmVarDecl * > & Params)2674 TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
2675                               SmallVectorImpl<ParmVarDecl *> &Params) {
2676   TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
2677   assert(OldTInfo && "substituting function without type source info");
2678   assert(Params.empty() && "parameter vector is non-empty at start");
2679 
2680   CXXRecordDecl *ThisContext = 0;
2681   unsigned ThisTypeQuals = 0;
2682   if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
2683     ThisContext = cast<CXXRecordDecl>(Owner);
2684     ThisTypeQuals = Method->getTypeQualifiers();
2685   }
2686 
2687   TypeSourceInfo *NewTInfo
2688     = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
2689                                     D->getTypeSpecStartLoc(),
2690                                     D->getDeclName(),
2691                                     ThisContext, ThisTypeQuals);
2692   if (!NewTInfo)
2693     return 0;
2694 
2695   TypeLoc OldTL = OldTInfo->getTypeLoc().IgnoreParens();
2696   if (FunctionProtoTypeLoc OldProtoLoc = OldTL.getAs<FunctionProtoTypeLoc>()) {
2697     if (NewTInfo != OldTInfo) {
2698       // Get parameters from the new type info.
2699       TypeLoc NewTL = NewTInfo->getTypeLoc().IgnoreParens();
2700       FunctionProtoTypeLoc NewProtoLoc = NewTL.castAs<FunctionProtoTypeLoc>();
2701       unsigned NewIdx = 0;
2702       for (unsigned OldIdx = 0, NumOldParams = OldProtoLoc.getNumArgs();
2703            OldIdx != NumOldParams; ++OldIdx) {
2704         ParmVarDecl *OldParam = OldProtoLoc.getArg(OldIdx);
2705         LocalInstantiationScope *Scope = SemaRef.CurrentInstantiationScope;
2706 
2707         Optional<unsigned> NumArgumentsInExpansion;
2708         if (OldParam->isParameterPack())
2709           NumArgumentsInExpansion =
2710               SemaRef.getNumArgumentsInExpansion(OldParam->getType(),
2711                                                  TemplateArgs);
2712         if (!NumArgumentsInExpansion) {
2713           // Simple case: normal parameter, or a parameter pack that's
2714           // instantiated to a (still-dependent) parameter pack.
2715           ParmVarDecl *NewParam = NewProtoLoc.getArg(NewIdx++);
2716           Params.push_back(NewParam);
2717           Scope->InstantiatedLocal(OldParam, NewParam);
2718         } else {
2719           // Parameter pack expansion: make the instantiation an argument pack.
2720           Scope->MakeInstantiatedLocalArgPack(OldParam);
2721           for (unsigned I = 0; I != *NumArgumentsInExpansion; ++I) {
2722             ParmVarDecl *NewParam = NewProtoLoc.getArg(NewIdx++);
2723             Params.push_back(NewParam);
2724             Scope->InstantiatedLocalPackArg(OldParam, NewParam);
2725           }
2726         }
2727       }
2728     } else {
2729       // The function type itself was not dependent and therefore no
2730       // substitution occurred. However, we still need to instantiate
2731       // the function parameters themselves.
2732       const FunctionProtoType *OldProto =
2733           cast<FunctionProtoType>(OldProtoLoc.getType());
2734       for (unsigned i = 0, i_end = OldProtoLoc.getNumArgs(); i != i_end; ++i) {
2735         ParmVarDecl *OldParam = OldProtoLoc.getArg(i);
2736         if (!OldParam) {
2737           Params.push_back(SemaRef.BuildParmVarDeclForTypedef(
2738               D, D->getLocation(), OldProto->getArgType(i)));
2739           continue;
2740         }
2741 
2742         ParmVarDecl *Parm =
2743             cast_or_null<ParmVarDecl>(VisitParmVarDecl(OldParam));
2744         if (!Parm)
2745           return 0;
2746         Params.push_back(Parm);
2747       }
2748     }
2749   } else {
2750     // If the type of this function, after ignoring parentheses, is not
2751     // *directly* a function type, then we're instantiating a function that
2752     // was declared via a typedef or with attributes, e.g.,
2753     //
2754     //   typedef int functype(int, int);
2755     //   functype func;
2756     //   int __cdecl meth(int, int);
2757     //
2758     // In this case, we'll just go instantiate the ParmVarDecls that we
2759     // synthesized in the method declaration.
2760     SmallVector<QualType, 4> ParamTypes;
2761     if (SemaRef.SubstParmTypes(D->getLocation(), D->param_begin(),
2762                                D->getNumParams(), TemplateArgs, ParamTypes,
2763                                &Params))
2764       return 0;
2765   }
2766 
2767   return NewTInfo;
2768 }
2769 
2770 /// Introduce the instantiated function parameters into the local
2771 /// instantiation scope, and set the parameter names to those used
2772 /// in the template.
addInstantiatedParametersToScope(Sema & S,FunctionDecl * Function,const FunctionDecl * PatternDecl,LocalInstantiationScope & Scope,const MultiLevelTemplateArgumentList & TemplateArgs)2773 static void addInstantiatedParametersToScope(Sema &S, FunctionDecl *Function,
2774                                              const FunctionDecl *PatternDecl,
2775                                              LocalInstantiationScope &Scope,
2776                            const MultiLevelTemplateArgumentList &TemplateArgs) {
2777   unsigned FParamIdx = 0;
2778   for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
2779     const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
2780     if (!PatternParam->isParameterPack()) {
2781       // Simple case: not a parameter pack.
2782       assert(FParamIdx < Function->getNumParams());
2783       ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
2784       FunctionParam->setDeclName(PatternParam->getDeclName());
2785       Scope.InstantiatedLocal(PatternParam, FunctionParam);
2786       ++FParamIdx;
2787       continue;
2788     }
2789 
2790     // Expand the parameter pack.
2791     Scope.MakeInstantiatedLocalArgPack(PatternParam);
2792     Optional<unsigned> NumArgumentsInExpansion
2793       = S.getNumArgumentsInExpansion(PatternParam->getType(), TemplateArgs);
2794     assert(NumArgumentsInExpansion &&
2795            "should only be called when all template arguments are known");
2796     for (unsigned Arg = 0; Arg < *NumArgumentsInExpansion; ++Arg) {
2797       ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
2798       FunctionParam->setDeclName(PatternParam->getDeclName());
2799       Scope.InstantiatedLocalPackArg(PatternParam, FunctionParam);
2800       ++FParamIdx;
2801     }
2802   }
2803 }
2804 
InstantiateExceptionSpec(Sema & SemaRef,FunctionDecl * New,const FunctionProtoType * Proto,const MultiLevelTemplateArgumentList & TemplateArgs)2805 static void InstantiateExceptionSpec(Sema &SemaRef, FunctionDecl *New,
2806                                      const FunctionProtoType *Proto,
2807                            const MultiLevelTemplateArgumentList &TemplateArgs) {
2808   assert(Proto->getExceptionSpecType() != EST_Uninstantiated);
2809 
2810   // C++11 [expr.prim.general]p3:
2811   //   If a declaration declares a member function or member function
2812   //   template of a class X, the expression this is a prvalue of type
2813   //   "pointer to cv-qualifier-seq X" between the optional cv-qualifer-seq
2814   //   and the end of the function-definition, member-declarator, or
2815   //   declarator.
2816   CXXRecordDecl *ThisContext = 0;
2817   unsigned ThisTypeQuals = 0;
2818   if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(New)) {
2819     ThisContext = Method->getParent();
2820     ThisTypeQuals = Method->getTypeQualifiers();
2821   }
2822   Sema::CXXThisScopeRAII ThisScope(SemaRef, ThisContext, ThisTypeQuals,
2823                                    SemaRef.getLangOpts().CPlusPlus11);
2824 
2825   // The function has an exception specification or a "noreturn"
2826   // attribute. Substitute into each of the exception types.
2827   SmallVector<QualType, 4> Exceptions;
2828   for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
2829     // FIXME: Poor location information!
2830     if (const PackExpansionType *PackExpansion
2831           = Proto->getExceptionType(I)->getAs<PackExpansionType>()) {
2832       // We have a pack expansion. Instantiate it.
2833       SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2834       SemaRef.collectUnexpandedParameterPacks(PackExpansion->getPattern(),
2835                                               Unexpanded);
2836       assert(!Unexpanded.empty() &&
2837              "Pack expansion without parameter packs?");
2838 
2839       bool Expand = false;
2840       bool RetainExpansion = false;
2841       Optional<unsigned> NumExpansions = PackExpansion->getNumExpansions();
2842       if (SemaRef.CheckParameterPacksForExpansion(New->getLocation(),
2843                                                   SourceRange(),
2844                                                   Unexpanded,
2845                                                   TemplateArgs,
2846                                                   Expand,
2847                                                   RetainExpansion,
2848                                                   NumExpansions))
2849         break;
2850 
2851       if (!Expand) {
2852         // We can't expand this pack expansion into separate arguments yet;
2853         // just substitute into the pattern and create a new pack expansion
2854         // type.
2855         Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2856         QualType T = SemaRef.SubstType(PackExpansion->getPattern(),
2857                                        TemplateArgs,
2858                                      New->getLocation(), New->getDeclName());
2859         if (T.isNull())
2860           break;
2861 
2862         T = SemaRef.Context.getPackExpansionType(T, NumExpansions);
2863         Exceptions.push_back(T);
2864         continue;
2865       }
2866 
2867       // Substitute into the pack expansion pattern for each template
2868       bool Invalid = false;
2869       for (unsigned ArgIdx = 0; ArgIdx != *NumExpansions; ++ArgIdx) {
2870         Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, ArgIdx);
2871 
2872         QualType T = SemaRef.SubstType(PackExpansion->getPattern(),
2873                                        TemplateArgs,
2874                                      New->getLocation(), New->getDeclName());
2875         if (T.isNull()) {
2876           Invalid = true;
2877           break;
2878         }
2879 
2880         Exceptions.push_back(T);
2881       }
2882 
2883       if (Invalid)
2884         break;
2885 
2886       continue;
2887     }
2888 
2889     QualType T
2890       = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
2891                           New->getLocation(), New->getDeclName());
2892     if (T.isNull() ||
2893         SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
2894       continue;
2895 
2896     Exceptions.push_back(T);
2897   }
2898   Expr *NoexceptExpr = 0;
2899   if (Expr *OldNoexceptExpr = Proto->getNoexceptExpr()) {
2900     EnterExpressionEvaluationContext Unevaluated(SemaRef,
2901                                                  Sema::ConstantEvaluated);
2902     ExprResult E = SemaRef.SubstExpr(OldNoexceptExpr, TemplateArgs);
2903     if (E.isUsable())
2904       E = SemaRef.CheckBooleanCondition(E.get(), E.get()->getLocStart());
2905 
2906     if (E.isUsable()) {
2907       NoexceptExpr = E.take();
2908       if (!NoexceptExpr->isTypeDependent() &&
2909           !NoexceptExpr->isValueDependent())
2910         NoexceptExpr
2911           = SemaRef.VerifyIntegerConstantExpression(NoexceptExpr,
2912               0, diag::err_noexcept_needs_constant_expression,
2913               /*AllowFold*/ false).take();
2914     }
2915   }
2916 
2917   // Rebuild the function type
2918   const FunctionProtoType *NewProto
2919     = New->getType()->getAs<FunctionProtoType>();
2920   assert(NewProto && "Template instantiation without function prototype?");
2921 
2922   FunctionProtoType::ExtProtoInfo EPI = NewProto->getExtProtoInfo();
2923   EPI.ExceptionSpecType = Proto->getExceptionSpecType();
2924   EPI.NumExceptions = Exceptions.size();
2925   EPI.Exceptions = Exceptions.data();
2926   EPI.NoexceptExpr = NoexceptExpr;
2927 
2928   New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
2929                                                NewProto->getArgTypes(), EPI));
2930 }
2931 
InstantiateExceptionSpec(SourceLocation PointOfInstantiation,FunctionDecl * Decl)2932 void Sema::InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
2933                                     FunctionDecl *Decl) {
2934   const FunctionProtoType *Proto = Decl->getType()->castAs<FunctionProtoType>();
2935   if (Proto->getExceptionSpecType() != EST_Uninstantiated)
2936     return;
2937 
2938   InstantiatingTemplate Inst(*this, PointOfInstantiation, Decl,
2939                              InstantiatingTemplate::ExceptionSpecification());
2940   if (Inst) {
2941     // We hit the instantiation depth limit. Clear the exception specification
2942     // so that our callers don't have to cope with EST_Uninstantiated.
2943     FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
2944     EPI.ExceptionSpecType = EST_None;
2945     Decl->setType(Context.getFunctionType(Proto->getResultType(),
2946                                           Proto->getArgTypes(), EPI));
2947     return;
2948   }
2949 
2950   // Enter the scope of this instantiation. We don't use
2951   // PushDeclContext because we don't have a scope.
2952   Sema::ContextRAII savedContext(*this, Decl);
2953   LocalInstantiationScope Scope(*this);
2954 
2955   MultiLevelTemplateArgumentList TemplateArgs =
2956     getTemplateInstantiationArgs(Decl, 0, /*RelativeToPrimary*/true);
2957 
2958   FunctionDecl *Template = Proto->getExceptionSpecTemplate();
2959   addInstantiatedParametersToScope(*this, Decl, Template, Scope, TemplateArgs);
2960 
2961   ::InstantiateExceptionSpec(*this, Decl,
2962                              Template->getType()->castAs<FunctionProtoType>(),
2963                              TemplateArgs);
2964 }
2965 
2966 /// \brief Initializes the common fields of an instantiation function
2967 /// declaration (New) from the corresponding fields of its template (Tmpl).
2968 ///
2969 /// \returns true if there was an error
2970 bool
InitFunctionInstantiation(FunctionDecl * New,FunctionDecl * Tmpl)2971 TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
2972                                                     FunctionDecl *Tmpl) {
2973   if (Tmpl->isDeleted())
2974     New->setDeletedAsWritten();
2975 
2976   // If we are performing substituting explicitly-specified template arguments
2977   // or deduced template arguments into a function template and we reach this
2978   // point, we are now past the point where SFINAE applies and have committed
2979   // to keeping the new function template specialization. We therefore
2980   // convert the active template instantiation for the function template
2981   // into a template instantiation for this specific function template
2982   // specialization, which is not a SFINAE context, so that we diagnose any
2983   // further errors in the declaration itself.
2984   typedef Sema::ActiveTemplateInstantiation ActiveInstType;
2985   ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
2986   if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
2987       ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
2988     if (FunctionTemplateDecl *FunTmpl
2989           = dyn_cast<FunctionTemplateDecl>(ActiveInst.Entity)) {
2990       assert(FunTmpl->getTemplatedDecl() == Tmpl &&
2991              "Deduction from the wrong function template?");
2992       (void) FunTmpl;
2993       ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
2994       ActiveInst.Entity = New;
2995     }
2996   }
2997 
2998   const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
2999   assert(Proto && "Function template without prototype?");
3000 
3001   if (Proto->hasExceptionSpec() || Proto->getNoReturnAttr()) {
3002     FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
3003 
3004     // DR1330: In C++11, defer instantiation of a non-trivial
3005     // exception specification.
3006     if (SemaRef.getLangOpts().CPlusPlus11 &&
3007         EPI.ExceptionSpecType != EST_None &&
3008         EPI.ExceptionSpecType != EST_DynamicNone &&
3009         EPI.ExceptionSpecType != EST_BasicNoexcept) {
3010       FunctionDecl *ExceptionSpecTemplate = Tmpl;
3011       if (EPI.ExceptionSpecType == EST_Uninstantiated)
3012         ExceptionSpecTemplate = EPI.ExceptionSpecTemplate;
3013       ExceptionSpecificationType NewEST = EST_Uninstantiated;
3014       if (EPI.ExceptionSpecType == EST_Unevaluated)
3015         NewEST = EST_Unevaluated;
3016 
3017       // Mark the function has having an uninstantiated exception specification.
3018       const FunctionProtoType *NewProto
3019         = New->getType()->getAs<FunctionProtoType>();
3020       assert(NewProto && "Template instantiation without function prototype?");
3021       EPI = NewProto->getExtProtoInfo();
3022       EPI.ExceptionSpecType = NewEST;
3023       EPI.ExceptionSpecDecl = New;
3024       EPI.ExceptionSpecTemplate = ExceptionSpecTemplate;
3025       New->setType(SemaRef.Context.getFunctionType(
3026           NewProto->getResultType(), NewProto->getArgTypes(), EPI));
3027     } else {
3028       ::InstantiateExceptionSpec(SemaRef, New, Proto, TemplateArgs);
3029     }
3030   }
3031 
3032   // Get the definition. Leaves the variable unchanged if undefined.
3033   const FunctionDecl *Definition = Tmpl;
3034   Tmpl->isDefined(Definition);
3035 
3036   SemaRef.InstantiateAttrs(TemplateArgs, Definition, New,
3037                            LateAttrs, StartingScope);
3038 
3039   return false;
3040 }
3041 
3042 /// \brief Initializes common fields of an instantiated method
3043 /// declaration (New) from the corresponding fields of its template
3044 /// (Tmpl).
3045 ///
3046 /// \returns true if there was an error
3047 bool
InitMethodInstantiation(CXXMethodDecl * New,CXXMethodDecl * Tmpl)3048 TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
3049                                                   CXXMethodDecl *Tmpl) {
3050   if (InitFunctionInstantiation(New, Tmpl))
3051     return true;
3052 
3053   New->setAccess(Tmpl->getAccess());
3054   if (Tmpl->isVirtualAsWritten())
3055     New->setVirtualAsWritten(true);
3056 
3057   // FIXME: New needs a pointer to Tmpl
3058   return false;
3059 }
3060 
3061 /// \brief Instantiate the definition of the given function from its
3062 /// template.
3063 ///
3064 /// \param PointOfInstantiation the point at which the instantiation was
3065 /// required. Note that this is not precisely a "point of instantiation"
3066 /// for the function, but it's close.
3067 ///
3068 /// \param Function the already-instantiated declaration of a
3069 /// function template specialization or member function of a class template
3070 /// specialization.
3071 ///
3072 /// \param Recursive if true, recursively instantiates any functions that
3073 /// are required by this instantiation.
3074 ///
3075 /// \param DefinitionRequired if true, then we are performing an explicit
3076 /// instantiation where the body of the function is required. Complain if
3077 /// there is no such body.
InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,FunctionDecl * Function,bool Recursive,bool DefinitionRequired)3078 void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
3079                                          FunctionDecl *Function,
3080                                          bool Recursive,
3081                                          bool DefinitionRequired) {
3082   if (Function->isInvalidDecl() || Function->isDefined())
3083     return;
3084 
3085   // Never instantiate an explicit specialization except if it is a class scope
3086   // explicit specialization.
3087   if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
3088       !Function->getClassScopeSpecializationPattern())
3089     return;
3090 
3091   // Find the function body that we'll be substituting.
3092   const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
3093   assert(PatternDecl && "instantiating a non-template");
3094 
3095   Stmt *Pattern = PatternDecl->getBody(PatternDecl);
3096   assert(PatternDecl && "template definition is not a template");
3097   if (!Pattern) {
3098     // Try to find a defaulted definition
3099     PatternDecl->isDefined(PatternDecl);
3100   }
3101   assert(PatternDecl && "template definition is not a template");
3102 
3103   // Postpone late parsed template instantiations.
3104   if (PatternDecl->isLateTemplateParsed() &&
3105       !LateTemplateParser) {
3106     PendingInstantiations.push_back(
3107       std::make_pair(Function, PointOfInstantiation));
3108     return;
3109   }
3110 
3111   // Call the LateTemplateParser callback if there a need to late parse
3112   // a templated function definition.
3113   if (!Pattern && PatternDecl->isLateTemplateParsed() &&
3114       LateTemplateParser) {
3115     LateTemplateParser(OpaqueParser, PatternDecl);
3116     Pattern = PatternDecl->getBody(PatternDecl);
3117   }
3118 
3119   if (!Pattern && !PatternDecl->isDefaulted()) {
3120     if (DefinitionRequired) {
3121       if (Function->getPrimaryTemplate())
3122         Diag(PointOfInstantiation,
3123              diag::err_explicit_instantiation_undefined_func_template)
3124           << Function->getPrimaryTemplate();
3125       else
3126         Diag(PointOfInstantiation,
3127              diag::err_explicit_instantiation_undefined_member)
3128           << 1 << Function->getDeclName() << Function->getDeclContext();
3129 
3130       if (PatternDecl)
3131         Diag(PatternDecl->getLocation(),
3132              diag::note_explicit_instantiation_here);
3133       Function->setInvalidDecl();
3134     } else if (Function->getTemplateSpecializationKind()
3135                  == TSK_ExplicitInstantiationDefinition) {
3136       PendingInstantiations.push_back(
3137         std::make_pair(Function, PointOfInstantiation));
3138     }
3139 
3140     return;
3141   }
3142 
3143   // C++1y [temp.explicit]p10:
3144   //   Except for inline functions, declarations with types deduced from their
3145   //   initializer or return value, and class template specializations, other
3146   //   explicit instantiation declarations have the effect of suppressing the
3147   //   implicit instantiation of the entity to which they refer.
3148   if (Function->getTemplateSpecializationKind()
3149         == TSK_ExplicitInstantiationDeclaration &&
3150       !PatternDecl->isInlined() &&
3151       !PatternDecl->getResultType()->isUndeducedType())
3152     return;
3153 
3154   if (PatternDecl->isInlined())
3155     Function->setImplicitlyInline();
3156 
3157   InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
3158   if (Inst)
3159     return;
3160 
3161   // Copy the inner loc start from the pattern.
3162   Function->setInnerLocStart(PatternDecl->getInnerLocStart());
3163 
3164   // If we're performing recursive template instantiation, create our own
3165   // queue of pending implicit instantiations that we will instantiate later,
3166   // while we're still within our own instantiation context.
3167   SmallVector<VTableUse, 16> SavedVTableUses;
3168   std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
3169   std::deque<PendingImplicitInstantiation>
3170                               SavedPendingLocalImplicitInstantiations;
3171   SavedPendingLocalImplicitInstantiations.swap(
3172                                   PendingLocalImplicitInstantiations);
3173   if (Recursive) {
3174     VTableUses.swap(SavedVTableUses);
3175     PendingInstantiations.swap(SavedPendingInstantiations);
3176   }
3177 
3178   EnterExpressionEvaluationContext EvalContext(*this,
3179                                                Sema::PotentiallyEvaluated);
3180 
3181   // Introduce a new scope where local variable instantiations will be
3182   // recorded, unless we're actually a member function within a local
3183   // class, in which case we need to merge our results with the parent
3184   // scope (of the enclosing function).
3185   bool MergeWithParentScope = false;
3186   if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
3187     MergeWithParentScope = Rec->isLocalClass();
3188 
3189   LocalInstantiationScope Scope(*this, MergeWithParentScope);
3190 
3191   if (PatternDecl->isDefaulted())
3192     SetDeclDefaulted(Function, PatternDecl->getLocation());
3193   else {
3194     ActOnStartOfFunctionDef(0, Function);
3195 
3196     // Enter the scope of this instantiation. We don't use
3197     // PushDeclContext because we don't have a scope.
3198     Sema::ContextRAII savedContext(*this, Function);
3199 
3200     MultiLevelTemplateArgumentList TemplateArgs =
3201       getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
3202 
3203     addInstantiatedParametersToScope(*this, Function, PatternDecl, Scope,
3204                                      TemplateArgs);
3205 
3206     // If this is a constructor, instantiate the member initializers.
3207     if (const CXXConstructorDecl *Ctor =
3208           dyn_cast<CXXConstructorDecl>(PatternDecl)) {
3209       InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
3210                                  TemplateArgs);
3211     }
3212 
3213     // Instantiate the function body.
3214     StmtResult Body = SubstStmt(Pattern, TemplateArgs);
3215 
3216     if (Body.isInvalid())
3217       Function->setInvalidDecl();
3218 
3219     ActOnFinishFunctionBody(Function, Body.get(),
3220                             /*IsInstantiation=*/true);
3221 
3222     PerformDependentDiagnostics(PatternDecl, TemplateArgs);
3223 
3224     savedContext.pop();
3225   }
3226 
3227   DeclGroupRef DG(Function);
3228   Consumer.HandleTopLevelDecl(DG);
3229 
3230   // This class may have local implicit instantiations that need to be
3231   // instantiation within this scope.
3232   PerformPendingInstantiations(/*LocalOnly=*/true);
3233   Scope.Exit();
3234 
3235   if (Recursive) {
3236     // Define any pending vtables.
3237     DefineUsedVTables();
3238 
3239     // Instantiate any pending implicit instantiations found during the
3240     // instantiation of this template.
3241     PerformPendingInstantiations();
3242 
3243     // Restore the set of pending vtables.
3244     assert(VTableUses.empty() &&
3245            "VTableUses should be empty before it is discarded.");
3246     VTableUses.swap(SavedVTableUses);
3247 
3248     // Restore the set of pending implicit instantiations.
3249     assert(PendingInstantiations.empty() &&
3250            "PendingInstantiations should be empty before it is discarded.");
3251     PendingInstantiations.swap(SavedPendingInstantiations);
3252   }
3253   SavedPendingLocalImplicitInstantiations.swap(
3254                             PendingLocalImplicitInstantiations);
3255 }
3256 
BuildVarTemplateInstantiation(VarTemplateDecl * VarTemplate,VarDecl * FromVar,const TemplateArgumentList & TemplateArgList,const TemplateArgumentListInfo & TemplateArgsInfo,SmallVectorImpl<TemplateArgument> & Converted,SourceLocation PointOfInstantiation,void * InsertPos,LateInstantiatedAttrVec * LateAttrs,LocalInstantiationScope * StartingScope)3257 VarTemplateSpecializationDecl *Sema::BuildVarTemplateInstantiation(
3258     VarTemplateDecl *VarTemplate, VarDecl *FromVar,
3259     const TemplateArgumentList &TemplateArgList,
3260     const TemplateArgumentListInfo &TemplateArgsInfo,
3261     SmallVectorImpl<TemplateArgument> &Converted,
3262     SourceLocation PointOfInstantiation, void *InsertPos,
3263     LateInstantiatedAttrVec *LateAttrs,
3264     LocalInstantiationScope *StartingScope) {
3265   if (FromVar->isInvalidDecl())
3266     return 0;
3267 
3268   InstantiatingTemplate Inst(*this, PointOfInstantiation, FromVar);
3269   if (Inst)
3270     return 0;
3271 
3272   MultiLevelTemplateArgumentList TemplateArgLists;
3273   TemplateArgLists.addOuterTemplateArguments(&TemplateArgList);
3274 
3275   TemplateDeclInstantiator Instantiator(
3276       *this, VarTemplate->getDeclContext(),
3277       MultiLevelTemplateArgumentList(TemplateArgList));
3278 
3279   // TODO: Set LateAttrs and StartingScope ...
3280 
3281   return cast_or_null<VarTemplateSpecializationDecl>(
3282       Instantiator.VisitVarTemplateSpecializationDecl(
3283           VarTemplate, FromVar, InsertPos, TemplateArgsInfo, Converted));
3284 }
3285 
3286 /// \brief Instantiates a variable template specialization by completing it
3287 /// with appropriate type information and initializer.
CompleteVarTemplateSpecializationDecl(VarTemplateSpecializationDecl * VarSpec,VarDecl * PatternDecl,const MultiLevelTemplateArgumentList & TemplateArgs)3288 VarTemplateSpecializationDecl *Sema::CompleteVarTemplateSpecializationDecl(
3289     VarTemplateSpecializationDecl *VarSpec, VarDecl *PatternDecl,
3290     const MultiLevelTemplateArgumentList &TemplateArgs) {
3291 
3292   // Do substitution on the type of the declaration
3293   TypeSourceInfo *DI =
3294       SubstType(PatternDecl->getTypeSourceInfo(), TemplateArgs,
3295                 PatternDecl->getTypeSpecStartLoc(), PatternDecl->getDeclName());
3296   if (!DI)
3297     return 0;
3298 
3299   // Update the type of this variable template specialization.
3300   VarSpec->setType(DI->getType());
3301 
3302   // Instantiate the initializer.
3303   InstantiateVariableInitializer(VarSpec, PatternDecl, TemplateArgs);
3304 
3305   return VarSpec;
3306 }
3307 
3308 /// BuildVariableInstantiation - Used after a new variable has been created.
3309 /// Sets basic variable data and decides whether to postpone the
3310 /// variable instantiation.
BuildVariableInstantiation(VarDecl * NewVar,VarDecl * OldVar,const MultiLevelTemplateArgumentList & TemplateArgs,LateInstantiatedAttrVec * LateAttrs,LocalInstantiationScope * StartingScope,bool ForVarTemplate)3311 void Sema::BuildVariableInstantiation(
3312     VarDecl *NewVar, VarDecl *OldVar,
3313     const MultiLevelTemplateArgumentList &TemplateArgs,
3314     LateInstantiatedAttrVec *LateAttrs,
3315     LocalInstantiationScope *StartingScope,
3316     bool ForVarTemplate) {
3317 
3318   // If we are instantiating a static data member defined
3319   // out-of-line, the instantiation will have the same lexical
3320   // context (which will be a namespace scope) as the template.
3321   if (OldVar->isOutOfLine())
3322     NewVar->setLexicalDeclContext(OldVar->getLexicalDeclContext());
3323   NewVar->setTSCSpec(OldVar->getTSCSpec());
3324   NewVar->setInitStyle(OldVar->getInitStyle());
3325   NewVar->setCXXForRangeDecl(OldVar->isCXXForRangeDecl());
3326   NewVar->setConstexpr(OldVar->isConstexpr());
3327   NewVar->setAccess(OldVar->getAccess());
3328 
3329   if (!OldVar->isStaticDataMember()) {
3330     NewVar->setUsed(OldVar->isUsed(false));
3331     NewVar->setReferenced(OldVar->isReferenced());
3332   }
3333 
3334   InstantiateAttrs(TemplateArgs, OldVar, NewVar, LateAttrs, StartingScope);
3335 
3336   if (NewVar->hasAttrs())
3337     CheckAlignasUnderalignment(NewVar);
3338 
3339   // FIXME: In theory, we could have a previous declaration for variables that
3340   // are not static data members.
3341   // FIXME: having to fake up a LookupResult is dumb.
3342   LookupResult Previous(*this, NewVar->getDeclName(), NewVar->getLocation(),
3343                         Sema::LookupOrdinaryName, Sema::ForRedeclaration);
3344 
3345   if (!isa<VarTemplateSpecializationDecl>(NewVar))
3346     LookupQualifiedName(Previous, NewVar->getDeclContext(), false);
3347 
3348   CheckVariableDeclaration(NewVar, Previous);
3349 
3350   if (OldVar->isOutOfLine()) {
3351     OldVar->getLexicalDeclContext()->addDecl(NewVar);
3352     if (!ForVarTemplate)
3353       NewVar->getDeclContext()->makeDeclVisibleInContext(NewVar);
3354   } else {
3355     if (!ForVarTemplate)
3356       NewVar->getDeclContext()->addDecl(NewVar);
3357     if (NewVar->getDeclContext()->isFunctionOrMethod())
3358       CurrentInstantiationScope->InstantiatedLocal(OldVar, NewVar);
3359   }
3360 
3361   // Link instantiations of static data members back to the template from
3362   // which they were instantiated.
3363   if (NewVar->isStaticDataMember() && !ForVarTemplate)
3364     NewVar->setInstantiationOfStaticDataMember(OldVar,
3365                                                TSK_ImplicitInstantiation);
3366 
3367   if (isa<VarTemplateSpecializationDecl>(NewVar)) {
3368     // Do not instantiate the variable just yet.
3369   } else
3370     InstantiateVariableInitializer(NewVar, OldVar, TemplateArgs);
3371 
3372   // Diagnose unused local variables with dependent types, where the diagnostic
3373   // will have been deferred.
3374   if (!NewVar->isInvalidDecl() &&
3375       NewVar->getDeclContext()->isFunctionOrMethod() && !NewVar->isUsed() &&
3376       OldVar->getType()->isDependentType())
3377     DiagnoseUnusedDecl(NewVar);
3378 }
3379 
3380 /// \brief Instantiate the initializer of a variable.
InstantiateVariableInitializer(VarDecl * Var,VarDecl * OldVar,const MultiLevelTemplateArgumentList & TemplateArgs)3381 void Sema::InstantiateVariableInitializer(
3382     VarDecl *Var, VarDecl *OldVar,
3383     const MultiLevelTemplateArgumentList &TemplateArgs) {
3384 
3385   if (Var->getAnyInitializer())
3386     // We already have an initializer in the class.
3387     return;
3388 
3389   if (OldVar->getInit()) {
3390     if (Var->isStaticDataMember() && !OldVar->isOutOfLine())
3391       PushExpressionEvaluationContext(Sema::ConstantEvaluated, OldVar);
3392     else
3393       PushExpressionEvaluationContext(Sema::PotentiallyEvaluated, OldVar);
3394 
3395     // Instantiate the initializer.
3396     ExprResult Init =
3397         SubstInitializer(OldVar->getInit(), TemplateArgs,
3398                          OldVar->getInitStyle() == VarDecl::CallInit);
3399     if (!Init.isInvalid()) {
3400       bool TypeMayContainAuto = true;
3401       if (Init.get()) {
3402         bool DirectInit = OldVar->isDirectInit();
3403         AddInitializerToDecl(Var, Init.take(), DirectInit, TypeMayContainAuto);
3404       } else
3405         ActOnUninitializedDecl(Var, TypeMayContainAuto);
3406     } else {
3407       // FIXME: Not too happy about invalidating the declaration
3408       // because of a bogus initializer.
3409       Var->setInvalidDecl();
3410     }
3411 
3412     PopExpressionEvaluationContext();
3413   } else if ((!Var->isStaticDataMember() || Var->isOutOfLine()) &&
3414              !Var->isCXXForRangeDecl())
3415     ActOnUninitializedDecl(Var, false);
3416 }
3417 
3418 /// \brief Instantiate the definition of the given variable from its
3419 /// template.
3420 ///
3421 /// \param PointOfInstantiation the point at which the instantiation was
3422 /// required. Note that this is not precisely a "point of instantiation"
3423 /// for the function, but it's close.
3424 ///
3425 /// \param Var the already-instantiated declaration of a static member
3426 /// variable of a class template specialization.
3427 ///
3428 /// \param Recursive if true, recursively instantiates any functions that
3429 /// are required by this instantiation.
3430 ///
3431 /// \param DefinitionRequired if true, then we are performing an explicit
3432 /// instantiation where an out-of-line definition of the member variable
3433 /// is required. Complain if there is no such definition.
InstantiateStaticDataMemberDefinition(SourceLocation PointOfInstantiation,VarDecl * Var,bool Recursive,bool DefinitionRequired)3434 void Sema::InstantiateStaticDataMemberDefinition(
3435                                           SourceLocation PointOfInstantiation,
3436                                                  VarDecl *Var,
3437                                                  bool Recursive,
3438                                                  bool DefinitionRequired) {
3439   InstantiateVariableDefinition(PointOfInstantiation, Var, Recursive,
3440                                 DefinitionRequired);
3441 }
3442 
InstantiateVariableDefinition(SourceLocation PointOfInstantiation,VarDecl * Var,bool Recursive,bool DefinitionRequired)3443 void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
3444                                          VarDecl *Var, bool Recursive,
3445                                          bool DefinitionRequired) {
3446 
3447   if (Var->isInvalidDecl())
3448     return;
3449 
3450   VarTemplateSpecializationDecl *VarSpec =
3451       dyn_cast<VarTemplateSpecializationDecl>(Var);
3452   assert((VarSpec || Var->isStaticDataMember()) &&
3453          "Not a static data member, nor a variable template specialization?");
3454   VarDecl *PatternDecl = 0;
3455 
3456   // If this is a variable template specialization, make sure that it is
3457   // non-dependent, then find its instantiation pattern.
3458   if (VarSpec) {
3459     bool InstantiationDependent = false;
3460     assert(!TemplateSpecializationType::anyDependentTemplateArguments(
3461                VarSpec->getTemplateArgsInfo(), InstantiationDependent) &&
3462            "Only instantiate variable template specializations that are "
3463            "not type-dependent");
3464     (void)InstantiationDependent;
3465 
3466     // Find the variable initialization that we'll be substituting.
3467     assert(VarSpec->getSpecializedTemplate() &&
3468            "Specialization without specialized template?");
3469     llvm::PointerUnion<VarTemplateDecl *,
3470                        VarTemplatePartialSpecializationDecl *> PatternPtr =
3471         VarSpec->getSpecializedTemplateOrPartial();
3472     if (PatternPtr.is<VarTemplatePartialSpecializationDecl *>())
3473       PatternDecl = cast<VarDecl>(
3474           PatternPtr.get<VarTemplatePartialSpecializationDecl *>());
3475     else
3476       PatternDecl = (PatternPtr.get<VarTemplateDecl *>())->getTemplatedDecl();
3477     assert(PatternDecl && "instantiating a non-template");
3478   }
3479 
3480   // If this is a static data member, find its out-of-line definition.
3481   VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
3482   if (Var->isStaticDataMember()) {
3483     assert(Def && "This data member was not instantiated from a template?");
3484     assert(Def->isStaticDataMember() && "Not a static data member?");
3485     Def = Def->getOutOfLineDefinition();
3486   }
3487 
3488   // If the instantiation pattern does not have an initializer, or if an
3489   // out-of-line definition is not found, we won't perform any instantiation.
3490   // Rather, we rely on the user to instantiate this definition (or provide
3491   // a specialization for it) in another translation unit.
3492   if ((VarSpec && !PatternDecl->getInit()) ||
3493       (!VarSpec && Var->isStaticDataMember() && !Def)) {
3494     if (DefinitionRequired) {
3495       if (!Var->isStaticDataMember()) {
3496         Diag(PointOfInstantiation,
3497              diag::err_explicit_instantiation_undefined_var_template)
3498             << PatternDecl;
3499         Diag(PatternDecl->getLocation(),
3500              diag::note_explicit_instantiation_here);
3501       } else {
3502         Def = Var->getInstantiatedFromStaticDataMember();
3503         Diag(PointOfInstantiation,
3504              diag::err_explicit_instantiation_undefined_member)
3505             << 3 << Var->getDeclName() << Var->getDeclContext();
3506         Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
3507       }
3508       if (VarSpec)
3509         Var->setInvalidDecl();
3510     } else if (Var->getTemplateSpecializationKind()
3511                  == TSK_ExplicitInstantiationDefinition) {
3512       PendingInstantiations.push_back(
3513         std::make_pair(Var, PointOfInstantiation));
3514     }
3515 
3516     return;
3517   }
3518 
3519   TemplateSpecializationKind TSK = Var->getTemplateSpecializationKind();
3520 
3521   // Never instantiate an explicit specialization.
3522   if (TSK == TSK_ExplicitSpecialization)
3523     return;
3524 
3525   // C++0x [temp.explicit]p9:
3526   //   Except for inline functions, other explicit instantiation declarations
3527   //   have the effect of suppressing the implicit instantiation of the entity
3528   //   to which they refer.
3529   //
3530   // C++11 [temp.explicit]p10:
3531   //   Except for inline functions, [...] explicit instantiation declarations
3532   //   have the effect of suppressing the implicit instantiation of the entity
3533   //   to which they refer.
3534   if (TSK == TSK_ExplicitInstantiationDeclaration)
3535     return;
3536 
3537   // Make sure to pass the instantiated variable to the consumer at the end.
3538   struct PassToConsumerRAII {
3539     ASTConsumer &Consumer;
3540     VarDecl *Var;
3541 
3542     PassToConsumerRAII(ASTConsumer &Consumer, VarDecl *Var)
3543       : Consumer(Consumer), Var(Var) { }
3544 
3545     ~PassToConsumerRAII() {
3546       if (Var->isStaticDataMember())
3547         Consumer.HandleCXXStaticMemberVarInstantiation(Var);
3548       else {
3549         DeclGroupRef DG(Var);
3550         Consumer.HandleTopLevelDecl(DG);
3551       }
3552     }
3553   } PassToConsumerRAII(Consumer, Var);
3554 
3555   if (!VarSpec) {
3556     // If we already have a definition, we're done.
3557     if (VarDecl *Def = Var->getDefinition()) {
3558       // We may be explicitly instantiating something we've already implicitly
3559       // instantiated.
3560       Def->setTemplateSpecializationKind(Var->getTemplateSpecializationKind(),
3561                                          PointOfInstantiation);
3562       return;
3563     }
3564   }
3565 
3566   InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
3567   if (Inst)
3568     return;
3569 
3570   // If we're performing recursive template instantiation, create our own
3571   // queue of pending implicit instantiations that we will instantiate later,
3572   // while we're still within our own instantiation context.
3573   SmallVector<VTableUse, 16> SavedVTableUses;
3574   std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
3575   if (Recursive) {
3576     VTableUses.swap(SavedVTableUses);
3577     PendingInstantiations.swap(SavedPendingInstantiations);
3578   }
3579 
3580   // Enter the scope of this instantiation. We don't use
3581   // PushDeclContext because we don't have a scope.
3582   ContextRAII PreviousContext(*this, Var->getDeclContext());
3583   LocalInstantiationScope Local(*this);
3584 
3585   VarDecl *OldVar = Var;
3586   if (!VarSpec)
3587     Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
3588                                           getTemplateInstantiationArgs(Var)));
3589   else
3590     // Construct a VarTemplateSpecializationDecl to avoid name clashing with
3591     // the primary template. (Note that unlike function declarations, variable
3592     // declarations cannot be overloaded.)
3593     // In fact, there is no need to construct a new declaration from scratch.
3594     // Thus, simply complete its definition with an appropriately substituted
3595     // type and initializer.
3596     Var = CompleteVarTemplateSpecializationDecl(
3597         VarSpec, PatternDecl, getTemplateInstantiationArgs(Var));
3598 
3599   PreviousContext.pop();
3600 
3601   if (Var) {
3602     MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
3603     if (!VarSpec)
3604       assert(MSInfo && "Missing member specialization information?");
3605 
3606     PassToConsumerRAII.Var = Var;
3607     if (MSInfo)
3608       Var->setTemplateSpecializationKind(
3609           MSInfo->getTemplateSpecializationKind(),
3610           MSInfo->getPointOfInstantiation());
3611   }
3612 
3613   // This variable may have local implicit instantiations that need to be
3614   // instantiated within this scope.
3615   PerformPendingInstantiations(/*LocalOnly=*/true);
3616 
3617   Local.Exit();
3618 
3619   if (Recursive) {
3620     // Define any newly required vtables.
3621     DefineUsedVTables();
3622 
3623     // Instantiate any pending implicit instantiations found during the
3624     // instantiation of this template.
3625     PerformPendingInstantiations();
3626 
3627     // Restore the set of pending vtables.
3628     assert(VTableUses.empty() &&
3629            "VTableUses should be empty before it is discarded.");
3630     VTableUses.swap(SavedVTableUses);
3631 
3632     // Restore the set of pending implicit instantiations.
3633     assert(PendingInstantiations.empty() &&
3634            "PendingInstantiations should be empty before it is discarded.");
3635     PendingInstantiations.swap(SavedPendingInstantiations);
3636   }
3637 }
3638 
3639 void
InstantiateMemInitializers(CXXConstructorDecl * New,const CXXConstructorDecl * Tmpl,const MultiLevelTemplateArgumentList & TemplateArgs)3640 Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
3641                                  const CXXConstructorDecl *Tmpl,
3642                            const MultiLevelTemplateArgumentList &TemplateArgs) {
3643 
3644   SmallVector<CXXCtorInitializer*, 4> NewInits;
3645   bool AnyErrors = Tmpl->isInvalidDecl();
3646 
3647   // Instantiate all the initializers.
3648   for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
3649                                             InitsEnd = Tmpl->init_end();
3650        Inits != InitsEnd; ++Inits) {
3651     CXXCtorInitializer *Init = *Inits;
3652 
3653     // Only instantiate written initializers, let Sema re-construct implicit
3654     // ones.
3655     if (!Init->isWritten())
3656       continue;
3657 
3658     SourceLocation EllipsisLoc;
3659 
3660     if (Init->isPackExpansion()) {
3661       // This is a pack expansion. We should expand it now.
3662       TypeLoc BaseTL = Init->getTypeSourceInfo()->getTypeLoc();
3663       SmallVector<UnexpandedParameterPack, 4> Unexpanded;
3664       collectUnexpandedParameterPacks(BaseTL, Unexpanded);
3665       collectUnexpandedParameterPacks(Init->getInit(), Unexpanded);
3666       bool ShouldExpand = false;
3667       bool RetainExpansion = false;
3668       Optional<unsigned> NumExpansions;
3669       if (CheckParameterPacksForExpansion(Init->getEllipsisLoc(),
3670                                           BaseTL.getSourceRange(),
3671                                           Unexpanded,
3672                                           TemplateArgs, ShouldExpand,
3673                                           RetainExpansion,
3674                                           NumExpansions)) {
3675         AnyErrors = true;
3676         New->setInvalidDecl();
3677         continue;
3678       }
3679       assert(ShouldExpand && "Partial instantiation of base initializer?");
3680 
3681       // Loop over all of the arguments in the argument pack(s),
3682       for (unsigned I = 0; I != *NumExpansions; ++I) {
3683         Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, I);
3684 
3685         // Instantiate the initializer.
3686         ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
3687                                                /*CXXDirectInit=*/true);
3688         if (TempInit.isInvalid()) {
3689           AnyErrors = true;
3690           break;
3691         }
3692 
3693         // Instantiate the base type.
3694         TypeSourceInfo *BaseTInfo = SubstType(Init->getTypeSourceInfo(),
3695                                               TemplateArgs,
3696                                               Init->getSourceLocation(),
3697                                               New->getDeclName());
3698         if (!BaseTInfo) {
3699           AnyErrors = true;
3700           break;
3701         }
3702 
3703         // Build the initializer.
3704         MemInitResult NewInit = BuildBaseInitializer(BaseTInfo->getType(),
3705                                                      BaseTInfo, TempInit.take(),
3706                                                      New->getParent(),
3707                                                      SourceLocation());
3708         if (NewInit.isInvalid()) {
3709           AnyErrors = true;
3710           break;
3711         }
3712 
3713         NewInits.push_back(NewInit.get());
3714       }
3715 
3716       continue;
3717     }
3718 
3719     // Instantiate the initializer.
3720     ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
3721                                            /*CXXDirectInit=*/true);
3722     if (TempInit.isInvalid()) {
3723       AnyErrors = true;
3724       continue;
3725     }
3726 
3727     MemInitResult NewInit;
3728     if (Init->isDelegatingInitializer() || Init->isBaseInitializer()) {
3729       TypeSourceInfo *TInfo = SubstType(Init->getTypeSourceInfo(),
3730                                         TemplateArgs,
3731                                         Init->getSourceLocation(),
3732                                         New->getDeclName());
3733       if (!TInfo) {
3734         AnyErrors = true;
3735         New->setInvalidDecl();
3736         continue;
3737       }
3738 
3739       if (Init->isBaseInitializer())
3740         NewInit = BuildBaseInitializer(TInfo->getType(), TInfo, TempInit.take(),
3741                                        New->getParent(), EllipsisLoc);
3742       else
3743         NewInit = BuildDelegatingInitializer(TInfo, TempInit.take(),
3744                                   cast<CXXRecordDecl>(CurContext->getParent()));
3745     } else if (Init->isMemberInitializer()) {
3746       FieldDecl *Member = cast_or_null<FieldDecl>(FindInstantiatedDecl(
3747                                                      Init->getMemberLocation(),
3748                                                      Init->getMember(),
3749                                                      TemplateArgs));
3750       if (!Member) {
3751         AnyErrors = true;
3752         New->setInvalidDecl();
3753         continue;
3754       }
3755 
3756       NewInit = BuildMemberInitializer(Member, TempInit.take(),
3757                                        Init->getSourceLocation());
3758     } else if (Init->isIndirectMemberInitializer()) {
3759       IndirectFieldDecl *IndirectMember =
3760          cast_or_null<IndirectFieldDecl>(FindInstantiatedDecl(
3761                                  Init->getMemberLocation(),
3762                                  Init->getIndirectMember(), TemplateArgs));
3763 
3764       if (!IndirectMember) {
3765         AnyErrors = true;
3766         New->setInvalidDecl();
3767         continue;
3768       }
3769 
3770       NewInit = BuildMemberInitializer(IndirectMember, TempInit.take(),
3771                                        Init->getSourceLocation());
3772     }
3773 
3774     if (NewInit.isInvalid()) {
3775       AnyErrors = true;
3776       New->setInvalidDecl();
3777     } else {
3778       NewInits.push_back(NewInit.get());
3779     }
3780   }
3781 
3782   // Assign all the initializers to the new constructor.
3783   ActOnMemInitializers(New,
3784                        /*FIXME: ColonLoc */
3785                        SourceLocation(),
3786                        NewInits,
3787                        AnyErrors);
3788 }
3789 
3790 // TODO: this could be templated if the various decl types used the
3791 // same method name.
isInstantiationOf(ClassTemplateDecl * Pattern,ClassTemplateDecl * Instance)3792 static bool isInstantiationOf(ClassTemplateDecl *Pattern,
3793                               ClassTemplateDecl *Instance) {
3794   Pattern = Pattern->getCanonicalDecl();
3795 
3796   do {
3797     Instance = Instance->getCanonicalDecl();
3798     if (Pattern == Instance) return true;
3799     Instance = Instance->getInstantiatedFromMemberTemplate();
3800   } while (Instance);
3801 
3802   return false;
3803 }
3804 
isInstantiationOf(FunctionTemplateDecl * Pattern,FunctionTemplateDecl * Instance)3805 static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
3806                               FunctionTemplateDecl *Instance) {
3807   Pattern = Pattern->getCanonicalDecl();
3808 
3809   do {
3810     Instance = Instance->getCanonicalDecl();
3811     if (Pattern == Instance) return true;
3812     Instance = Instance->getInstantiatedFromMemberTemplate();
3813   } while (Instance);
3814 
3815   return false;
3816 }
3817 
3818 static bool
isInstantiationOf(ClassTemplatePartialSpecializationDecl * Pattern,ClassTemplatePartialSpecializationDecl * Instance)3819 isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
3820                   ClassTemplatePartialSpecializationDecl *Instance) {
3821   Pattern
3822     = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
3823   do {
3824     Instance = cast<ClassTemplatePartialSpecializationDecl>(
3825                                                 Instance->getCanonicalDecl());
3826     if (Pattern == Instance)
3827       return true;
3828     Instance = Instance->getInstantiatedFromMember();
3829   } while (Instance);
3830 
3831   return false;
3832 }
3833 
isInstantiationOf(CXXRecordDecl * Pattern,CXXRecordDecl * Instance)3834 static bool isInstantiationOf(CXXRecordDecl *Pattern,
3835                               CXXRecordDecl *Instance) {
3836   Pattern = Pattern->getCanonicalDecl();
3837 
3838   do {
3839     Instance = Instance->getCanonicalDecl();
3840     if (Pattern == Instance) return true;
3841     Instance = Instance->getInstantiatedFromMemberClass();
3842   } while (Instance);
3843 
3844   return false;
3845 }
3846 
isInstantiationOf(FunctionDecl * Pattern,FunctionDecl * Instance)3847 static bool isInstantiationOf(FunctionDecl *Pattern,
3848                               FunctionDecl *Instance) {
3849   Pattern = Pattern->getCanonicalDecl();
3850 
3851   do {
3852     Instance = Instance->getCanonicalDecl();
3853     if (Pattern == Instance) return true;
3854     Instance = Instance->getInstantiatedFromMemberFunction();
3855   } while (Instance);
3856 
3857   return false;
3858 }
3859 
isInstantiationOf(EnumDecl * Pattern,EnumDecl * Instance)3860 static bool isInstantiationOf(EnumDecl *Pattern,
3861                               EnumDecl *Instance) {
3862   Pattern = Pattern->getCanonicalDecl();
3863 
3864   do {
3865     Instance = Instance->getCanonicalDecl();
3866     if (Pattern == Instance) return true;
3867     Instance = Instance->getInstantiatedFromMemberEnum();
3868   } while (Instance);
3869 
3870   return false;
3871 }
3872 
isInstantiationOf(UsingShadowDecl * Pattern,UsingShadowDecl * Instance,ASTContext & C)3873 static bool isInstantiationOf(UsingShadowDecl *Pattern,
3874                               UsingShadowDecl *Instance,
3875                               ASTContext &C) {
3876   return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
3877 }
3878 
isInstantiationOf(UsingDecl * Pattern,UsingDecl * Instance,ASTContext & C)3879 static bool isInstantiationOf(UsingDecl *Pattern,
3880                               UsingDecl *Instance,
3881                               ASTContext &C) {
3882   return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
3883 }
3884 
isInstantiationOf(UnresolvedUsingValueDecl * Pattern,UsingDecl * Instance,ASTContext & C)3885 static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
3886                               UsingDecl *Instance,
3887                               ASTContext &C) {
3888   return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
3889 }
3890 
isInstantiationOf(UnresolvedUsingTypenameDecl * Pattern,UsingDecl * Instance,ASTContext & C)3891 static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
3892                               UsingDecl *Instance,
3893                               ASTContext &C) {
3894   return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
3895 }
3896 
isInstantiationOfStaticDataMember(VarDecl * Pattern,VarDecl * Instance)3897 static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
3898                                               VarDecl *Instance) {
3899   assert(Instance->isStaticDataMember());
3900 
3901   Pattern = Pattern->getCanonicalDecl();
3902 
3903   do {
3904     Instance = Instance->getCanonicalDecl();
3905     if (Pattern == Instance) return true;
3906     Instance = Instance->getInstantiatedFromStaticDataMember();
3907   } while (Instance);
3908 
3909   return false;
3910 }
3911 
3912 // Other is the prospective instantiation
3913 // D is the prospective pattern
isInstantiationOf(ASTContext & Ctx,NamedDecl * D,Decl * Other)3914 static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
3915   if (D->getKind() != Other->getKind()) {
3916     if (UnresolvedUsingTypenameDecl *UUD
3917           = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
3918       if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
3919         return isInstantiationOf(UUD, UD, Ctx);
3920       }
3921     }
3922 
3923     if (UnresolvedUsingValueDecl *UUD
3924           = dyn_cast<UnresolvedUsingValueDecl>(D)) {
3925       if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
3926         return isInstantiationOf(UUD, UD, Ctx);
3927       }
3928     }
3929 
3930     return false;
3931   }
3932 
3933   if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
3934     return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
3935 
3936   if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
3937     return isInstantiationOf(cast<FunctionDecl>(D), Function);
3938 
3939   if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
3940     return isInstantiationOf(cast<EnumDecl>(D), Enum);
3941 
3942   if (VarDecl *Var = dyn_cast<VarDecl>(Other))
3943     if (Var->isStaticDataMember())
3944       return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
3945 
3946   if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
3947     return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
3948 
3949   if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
3950     return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
3951 
3952   if (ClassTemplatePartialSpecializationDecl *PartialSpec
3953         = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
3954     return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
3955                              PartialSpec);
3956 
3957   if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
3958     if (!Field->getDeclName()) {
3959       // This is an unnamed field.
3960       return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
3961         cast<FieldDecl>(D);
3962     }
3963   }
3964 
3965   if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
3966     return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
3967 
3968   if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
3969     return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
3970 
3971   return D->getDeclName() && isa<NamedDecl>(Other) &&
3972     D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
3973 }
3974 
3975 template<typename ForwardIterator>
findInstantiationOf(ASTContext & Ctx,NamedDecl * D,ForwardIterator first,ForwardIterator last)3976 static NamedDecl *findInstantiationOf(ASTContext &Ctx,
3977                                       NamedDecl *D,
3978                                       ForwardIterator first,
3979                                       ForwardIterator last) {
3980   for (; first != last; ++first)
3981     if (isInstantiationOf(Ctx, D, *first))
3982       return cast<NamedDecl>(*first);
3983 
3984   return 0;
3985 }
3986 
3987 /// \brief Finds the instantiation of the given declaration context
3988 /// within the current instantiation.
3989 ///
3990 /// \returns NULL if there was an error
FindInstantiatedContext(SourceLocation Loc,DeclContext * DC,const MultiLevelTemplateArgumentList & TemplateArgs)3991 DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
3992                           const MultiLevelTemplateArgumentList &TemplateArgs) {
3993   if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
3994     Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
3995     return cast_or_null<DeclContext>(ID);
3996   } else return DC;
3997 }
3998 
3999 /// \brief Find the instantiation of the given declaration within the
4000 /// current instantiation.
4001 ///
4002 /// This routine is intended to be used when \p D is a declaration
4003 /// referenced from within a template, that needs to mapped into the
4004 /// corresponding declaration within an instantiation. For example,
4005 /// given:
4006 ///
4007 /// \code
4008 /// template<typename T>
4009 /// struct X {
4010 ///   enum Kind {
4011 ///     KnownValue = sizeof(T)
4012 ///   };
4013 ///
4014 ///   bool getKind() const { return KnownValue; }
4015 /// };
4016 ///
4017 /// template struct X<int>;
4018 /// \endcode
4019 ///
4020 /// In the instantiation of <tt>X<int>::getKind()</tt>, we need to map the
4021 /// \p EnumConstantDecl for \p KnownValue (which refers to
4022 /// <tt>X<T>::<Kind>::KnownValue</tt>) to its instantiation
4023 /// (<tt>X<int>::<Kind>::KnownValue</tt>). \p FindInstantiatedDecl performs
4024 /// this mapping from within the instantiation of <tt>X<int></tt>.
FindInstantiatedDecl(SourceLocation Loc,NamedDecl * D,const MultiLevelTemplateArgumentList & TemplateArgs)4025 NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
4026                           const MultiLevelTemplateArgumentList &TemplateArgs) {
4027   DeclContext *ParentDC = D->getDeclContext();
4028   if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
4029       isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
4030       (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext()) ||
4031       (isa<CXXRecordDecl>(D) && cast<CXXRecordDecl>(D)->isLambda())) {
4032     // D is a local of some kind. Look into the map of local
4033     // declarations to their instantiations.
4034     typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
4035     llvm::PointerUnion<Decl *, DeclArgumentPack *> *Found
4036       = CurrentInstantiationScope->findInstantiationOf(D);
4037 
4038     if (Found) {
4039       if (Decl *FD = Found->dyn_cast<Decl *>())
4040         return cast<NamedDecl>(FD);
4041 
4042       int PackIdx = ArgumentPackSubstitutionIndex;
4043       assert(PackIdx != -1 && "found declaration pack but not pack expanding");
4044       return cast<NamedDecl>((*Found->get<DeclArgumentPack *>())[PackIdx]);
4045     }
4046 
4047     // If we're performing a partial substitution during template argument
4048     // deduction, we may not have values for template parameters yet. They
4049     // just map to themselves.
4050     if (isa<NonTypeTemplateParmDecl>(D) || isa<TemplateTypeParmDecl>(D) ||
4051         isa<TemplateTemplateParmDecl>(D))
4052       return D;
4053 
4054     // If we didn't find the decl, then we must have a label decl that hasn't
4055     // been found yet.  Lazily instantiate it and return it now.
4056     assert(isa<LabelDecl>(D));
4057 
4058     Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
4059     assert(Inst && "Failed to instantiate label??");
4060 
4061     CurrentInstantiationScope->InstantiatedLocal(D, Inst);
4062     return cast<LabelDecl>(Inst);
4063   }
4064 
4065   // For variable template specializations, update those that are still
4066   // type-dependent.
4067   if (VarTemplateSpecializationDecl *VarSpec =
4068           dyn_cast<VarTemplateSpecializationDecl>(D)) {
4069     bool InstantiationDependent = false;
4070     const TemplateArgumentListInfo &VarTemplateArgs =
4071         VarSpec->getTemplateArgsInfo();
4072     if (TemplateSpecializationType::anyDependentTemplateArguments(
4073             VarTemplateArgs, InstantiationDependent))
4074       D = cast<NamedDecl>(
4075           SubstDecl(D, VarSpec->getDeclContext(), TemplateArgs));
4076     return D;
4077   }
4078 
4079   if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
4080     if (!Record->isDependentContext())
4081       return D;
4082 
4083     // Determine whether this record is the "templated" declaration describing
4084     // a class template or class template partial specialization.
4085     ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
4086     if (ClassTemplate)
4087       ClassTemplate = ClassTemplate->getCanonicalDecl();
4088     else if (ClassTemplatePartialSpecializationDecl *PartialSpec
4089                = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record))
4090       ClassTemplate = PartialSpec->getSpecializedTemplate()->getCanonicalDecl();
4091 
4092     // Walk the current context to find either the record or an instantiation of
4093     // it.
4094     DeclContext *DC = CurContext;
4095     while (!DC->isFileContext()) {
4096       // If we're performing substitution while we're inside the template
4097       // definition, we'll find our own context. We're done.
4098       if (DC->Equals(Record))
4099         return Record;
4100 
4101       if (CXXRecordDecl *InstRecord = dyn_cast<CXXRecordDecl>(DC)) {
4102         // Check whether we're in the process of instantiating a class template
4103         // specialization of the template we're mapping.
4104         if (ClassTemplateSpecializationDecl *InstSpec
4105                       = dyn_cast<ClassTemplateSpecializationDecl>(InstRecord)){
4106           ClassTemplateDecl *SpecTemplate = InstSpec->getSpecializedTemplate();
4107           if (ClassTemplate && isInstantiationOf(ClassTemplate, SpecTemplate))
4108             return InstRecord;
4109         }
4110 
4111         // Check whether we're in the process of instantiating a member class.
4112         if (isInstantiationOf(Record, InstRecord))
4113           return InstRecord;
4114       }
4115 
4116       // Move to the outer template scope.
4117       if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) {
4118         if (FD->getFriendObjectKind() && FD->getDeclContext()->isFileContext()){
4119           DC = FD->getLexicalDeclContext();
4120           continue;
4121         }
4122       }
4123 
4124       DC = DC->getParent();
4125     }
4126 
4127     // Fall through to deal with other dependent record types (e.g.,
4128     // anonymous unions in class templates).
4129   }
4130 
4131   if (!ParentDC->isDependentContext())
4132     return D;
4133 
4134   ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
4135   if (!ParentDC)
4136     return 0;
4137 
4138   if (ParentDC != D->getDeclContext()) {
4139     // We performed some kind of instantiation in the parent context,
4140     // so now we need to look into the instantiated parent context to
4141     // find the instantiation of the declaration D.
4142 
4143     // If our context used to be dependent, we may need to instantiate
4144     // it before performing lookup into that context.
4145     bool IsBeingInstantiated = false;
4146     if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
4147       if (!Spec->isDependentContext()) {
4148         QualType T = Context.getTypeDeclType(Spec);
4149         const RecordType *Tag = T->getAs<RecordType>();
4150         assert(Tag && "type of non-dependent record is not a RecordType");
4151         if (Tag->isBeingDefined())
4152           IsBeingInstantiated = true;
4153         if (!Tag->isBeingDefined() &&
4154             RequireCompleteType(Loc, T, diag::err_incomplete_type))
4155           return 0;
4156 
4157         ParentDC = Tag->getDecl();
4158       }
4159     }
4160 
4161     NamedDecl *Result = 0;
4162     if (D->getDeclName()) {
4163       DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
4164       Result = findInstantiationOf(Context, D, Found.begin(), Found.end());
4165     } else {
4166       // Since we don't have a name for the entity we're looking for,
4167       // our only option is to walk through all of the declarations to
4168       // find that name. This will occur in a few cases:
4169       //
4170       //   - anonymous struct/union within a template
4171       //   - unnamed class/struct/union/enum within a template
4172       //
4173       // FIXME: Find a better way to find these instantiations!
4174       Result = findInstantiationOf(Context, D,
4175                                    ParentDC->decls_begin(),
4176                                    ParentDC->decls_end());
4177     }
4178 
4179     if (!Result) {
4180       if (isa<UsingShadowDecl>(D)) {
4181         // UsingShadowDecls can instantiate to nothing because of using hiding.
4182       } else if (Diags.hasErrorOccurred()) {
4183         // We've already complained about something, so most likely this
4184         // declaration failed to instantiate. There's no point in complaining
4185         // further, since this is normal in invalid code.
4186       } else if (IsBeingInstantiated) {
4187         // The class in which this member exists is currently being
4188         // instantiated, and we haven't gotten around to instantiating this
4189         // member yet. This can happen when the code uses forward declarations
4190         // of member classes, and introduces ordering dependencies via
4191         // template instantiation.
4192         Diag(Loc, diag::err_member_not_yet_instantiated)
4193           << D->getDeclName()
4194           << Context.getTypeDeclType(cast<CXXRecordDecl>(ParentDC));
4195         Diag(D->getLocation(), diag::note_non_instantiated_member_here);
4196       } else if (EnumConstantDecl *ED = dyn_cast<EnumConstantDecl>(D)) {
4197         // This enumeration constant was found when the template was defined,
4198         // but can't be found in the instantiation. This can happen if an
4199         // unscoped enumeration member is explicitly specialized.
4200         EnumDecl *Enum = cast<EnumDecl>(ED->getLexicalDeclContext());
4201         EnumDecl *Spec = cast<EnumDecl>(FindInstantiatedDecl(Loc, Enum,
4202                                                              TemplateArgs));
4203         assert(Spec->getTemplateSpecializationKind() ==
4204                  TSK_ExplicitSpecialization);
4205         Diag(Loc, diag::err_enumerator_does_not_exist)
4206           << D->getDeclName()
4207           << Context.getTypeDeclType(cast<TypeDecl>(Spec->getDeclContext()));
4208         Diag(Spec->getLocation(), diag::note_enum_specialized_here)
4209           << Context.getTypeDeclType(Spec);
4210       } else {
4211         // We should have found something, but didn't.
4212         llvm_unreachable("Unable to find instantiation of declaration!");
4213       }
4214     }
4215 
4216     D = Result;
4217   }
4218 
4219   return D;
4220 }
4221 
4222 /// \brief Performs template instantiation for all implicit template
4223 /// instantiations we have seen until this point.
PerformPendingInstantiations(bool LocalOnly)4224 void Sema::PerformPendingInstantiations(bool LocalOnly) {
4225   // Load pending instantiations from the external source.
4226   if (!LocalOnly && ExternalSource) {
4227     SmallVector<PendingImplicitInstantiation, 4> Pending;
4228     ExternalSource->ReadPendingInstantiations(Pending);
4229     PendingInstantiations.insert(PendingInstantiations.begin(),
4230                                  Pending.begin(), Pending.end());
4231   }
4232 
4233   while (!PendingLocalImplicitInstantiations.empty() ||
4234          (!LocalOnly && !PendingInstantiations.empty())) {
4235     PendingImplicitInstantiation Inst;
4236 
4237     if (PendingLocalImplicitInstantiations.empty()) {
4238       Inst = PendingInstantiations.front();
4239       PendingInstantiations.pop_front();
4240     } else {
4241       Inst = PendingLocalImplicitInstantiations.front();
4242       PendingLocalImplicitInstantiations.pop_front();
4243     }
4244 
4245     // Instantiate function definitions
4246     if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
4247       PrettyDeclStackTraceEntry CrashInfo(*this, Function, SourceLocation(),
4248                                           "instantiating function definition");
4249       bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
4250                                 TSK_ExplicitInstantiationDefinition;
4251       InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true,
4252                                     DefinitionRequired);
4253       continue;
4254     }
4255 
4256     // Instantiate variable definitions
4257     VarDecl *Var = cast<VarDecl>(Inst.first);
4258 
4259     assert((Var->isStaticDataMember() ||
4260             isa<VarTemplateSpecializationDecl>(Var)) &&
4261            "Not a static data member, nor a variable template"
4262            " specialization?");
4263 
4264     // Don't try to instantiate declarations if the most recent redeclaration
4265     // is invalid.
4266     if (Var->getMostRecentDecl()->isInvalidDecl())
4267       continue;
4268 
4269     // Check if the most recent declaration has changed the specialization kind
4270     // and removed the need for implicit instantiation.
4271     switch (Var->getMostRecentDecl()->getTemplateSpecializationKind()) {
4272     case TSK_Undeclared:
4273       llvm_unreachable("Cannot instantitiate an undeclared specialization.");
4274     case TSK_ExplicitInstantiationDeclaration:
4275     case TSK_ExplicitSpecialization:
4276       continue;  // No longer need to instantiate this type.
4277     case TSK_ExplicitInstantiationDefinition:
4278       // We only need an instantiation if the pending instantiation *is* the
4279       // explicit instantiation.
4280       if (Var != Var->getMostRecentDecl()) continue;
4281     case TSK_ImplicitInstantiation:
4282       break;
4283     }
4284 
4285     PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
4286                                         "instantiating variable definition");
4287     bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
4288                               TSK_ExplicitInstantiationDefinition;
4289 
4290     // Instantiate static data member definitions or variable template
4291     // specializations.
4292     InstantiateVariableDefinition(/*FIXME:*/ Inst.second, Var, true,
4293                                   DefinitionRequired);
4294   }
4295 }
4296 
PerformDependentDiagnostics(const DeclContext * Pattern,const MultiLevelTemplateArgumentList & TemplateArgs)4297 void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
4298                        const MultiLevelTemplateArgumentList &TemplateArgs) {
4299   for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
4300          E = Pattern->ddiag_end(); I != E; ++I) {
4301     DependentDiagnostic *DD = *I;
4302 
4303     switch (DD->getKind()) {
4304     case DependentDiagnostic::Access:
4305       HandleDependentAccessCheck(*DD, TemplateArgs);
4306       break;
4307     }
4308   }
4309 }
4310