SemaTemplateInstantiateDecl.cpp revision 7a614d8380297fcd2bc23986241905d97222948c 
1//===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//===----------------------------------------------------------------------===/
8//
9//  This file implements C++ template instantiation for declarations.
10//
11//===----------------------------------------------------------------------===/
12#include "clang/Sema/SemaInternal.h"
13#include "clang/Sema/Lookup.h"
14#include "clang/Sema/PrettyDeclStackTrace.h"
15#include "clang/Sema/Template.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/DeclTemplate.h"
19#include "clang/AST/DeclVisitor.h"
20#include "clang/AST/DependentDiagnostic.h"
21#include "clang/AST/Expr.h"
22#include "clang/AST/ExprCXX.h"
23#include "clang/AST/TypeLoc.h"
24#include "clang/Lex/Preprocessor.h"
25
26using namespace clang;
27
28bool 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
44bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
45                                              TagDecl *NewDecl) {
46  if (!OldDecl->getQualifierLoc())
47    return false;
48
49  NestedNameSpecifierLoc NewQualifierLoc
50  = SemaRef.SubstNestedNameSpecifierLoc(OldDecl->getQualifierLoc(),
51                                        TemplateArgs);
52
53  if (!NewQualifierLoc)
54    return true;
55
56  NewDecl->setQualifierInfo(NewQualifierLoc);
57  return false;
58}
59
60// FIXME: Is this still too simple?
61void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
62                            Decl *Tmpl, Decl *New) {
63  for (AttrVec::const_iterator i = Tmpl->attr_begin(), e = Tmpl->attr_end();
64       i != e; ++i) {
65    const Attr *TmplAttr = *i;
66    // FIXME: This should be generalized to more than just the AlignedAttr.
67    if (const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr)) {
68      if (Aligned->isAlignmentDependent()) {
69        // The alignment expression is not potentially evaluated.
70        EnterExpressionEvaluationContext Unevaluated(*this,
71                                                     Sema::Unevaluated);
72
73        if (Aligned->isAlignmentExpr()) {
74          ExprResult Result = SubstExpr(Aligned->getAlignmentExpr(),
75                                        TemplateArgs);
76          if (!Result.isInvalid())
77            AddAlignedAttr(Aligned->getLocation(), New, Result.takeAs<Expr>());
78        }
79        else {
80          TypeSourceInfo *Result = SubstType(Aligned->getAlignmentType(),
81                                             TemplateArgs,
82                                             Aligned->getLocation(),
83                                             DeclarationName());
84          if (Result)
85            AddAlignedAttr(Aligned->getLocation(), New, Result);
86        }
87        continue;
88      }
89    }
90
91    // FIXME: Is cloning correct for all attributes?
92    Attr *NewAttr = TmplAttr->clone(Context);
93    New->addAttr(NewAttr);
94  }
95}
96
97Decl *
98TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
99  assert(false && "Translation units cannot be instantiated");
100  return D;
101}
102
103Decl *
104TemplateDeclInstantiator::VisitLabelDecl(LabelDecl *D) {
105  LabelDecl *Inst = LabelDecl::Create(SemaRef.Context, Owner, D->getLocation(),
106                                      D->getIdentifier());
107  Owner->addDecl(Inst);
108  return Inst;
109}
110
111Decl *
112TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
113  assert(false && "Namespaces cannot be instantiated");
114  return D;
115}
116
117Decl *
118TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
119  NamespaceAliasDecl *Inst
120    = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
121                                 D->getNamespaceLoc(),
122                                 D->getAliasLoc(),
123                                 D->getIdentifier(),
124                                 D->getQualifierLoc(),
125                                 D->getTargetNameLoc(),
126                                 D->getNamespace());
127  Owner->addDecl(Inst);
128  return Inst;
129}
130
131Decl *TemplateDeclInstantiator::InstantiateTypedefNameDecl(TypedefNameDecl *D,
132                                                           bool IsTypeAlias) {
133  bool Invalid = false;
134  TypeSourceInfo *DI = D->getTypeSourceInfo();
135  if (DI->getType()->isDependentType() ||
136      DI->getType()->isVariablyModifiedType()) {
137    DI = SemaRef.SubstType(DI, TemplateArgs,
138                           D->getLocation(), D->getDeclName());
139    if (!DI) {
140      Invalid = true;
141      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
142    }
143  } else {
144    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
145  }
146
147  // Create the new typedef
148  TypedefNameDecl *Typedef;
149  if (IsTypeAlias)
150    Typedef = TypeAliasDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
151                                    D->getLocation(), D->getIdentifier(), DI);
152  else
153    Typedef = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
154                                  D->getLocation(), D->getIdentifier(), DI);
155  if (Invalid)
156    Typedef->setInvalidDecl();
157
158  // If the old typedef was the name for linkage purposes of an anonymous
159  // tag decl, re-establish that relationship for the new typedef.
160  if (const TagType *oldTagType = D->getUnderlyingType()->getAs<TagType>()) {
161    TagDecl *oldTag = oldTagType->getDecl();
162    if (oldTag->getTypedefNameForAnonDecl() == D) {
163      TagDecl *newTag = DI->getType()->castAs<TagType>()->getDecl();
164      assert(!newTag->getIdentifier() && !newTag->getTypedefNameForAnonDecl());
165      newTag->setTypedefNameForAnonDecl(Typedef);
166    }
167  }
168
169  if (TypedefNameDecl *Prev = D->getPreviousDeclaration()) {
170    NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
171                                                       TemplateArgs);
172    if (!InstPrev)
173      return 0;
174
175    Typedef->setPreviousDeclaration(cast<TypedefNameDecl>(InstPrev));
176  }
177
178  SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef);
179
180  Typedef->setAccess(D->getAccess());
181
182  return Typedef;
183}
184
185Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
186  Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/false);
187  Owner->addDecl(Typedef);
188  return Typedef;
189}
190
191Decl *TemplateDeclInstantiator::VisitTypeAliasDecl(TypeAliasDecl *D) {
192  Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/true);
193  Owner->addDecl(Typedef);
194  return Typedef;
195}
196
197Decl *
198TemplateDeclInstantiator::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
199  // Create a local instantiation scope for this type alias template, which
200  // will contain the instantiations of the template parameters.
201  LocalInstantiationScope Scope(SemaRef);
202
203  TemplateParameterList *TempParams = D->getTemplateParameters();
204  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
205  if (!InstParams)
206    return 0;
207
208  TypeAliasDecl *Pattern = D->getTemplatedDecl();
209
210  TypeAliasTemplateDecl *PrevAliasTemplate = 0;
211  if (Pattern->getPreviousDeclaration()) {
212    DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
213    if (Found.first != Found.second) {
214      PrevAliasTemplate = dyn_cast<TypeAliasTemplateDecl>(*Found.first);
215    }
216  }
217
218  TypeAliasDecl *AliasInst = cast_or_null<TypeAliasDecl>(
219    InstantiateTypedefNameDecl(Pattern, /*IsTypeAlias=*/true));
220  if (!AliasInst)
221    return 0;
222
223  TypeAliasTemplateDecl *Inst
224    = TypeAliasTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
225                                    D->getDeclName(), InstParams, AliasInst);
226  if (PrevAliasTemplate)
227    Inst->setPreviousDeclaration(PrevAliasTemplate);
228
229  Inst->setAccess(D->getAccess());
230
231  if (!PrevAliasTemplate)
232    Inst->setInstantiatedFromMemberTemplate(D);
233
234  Owner->addDecl(Inst);
235
236  return Inst;
237}
238
239/// \brief Instantiate an initializer, breaking it into separate
240/// initialization arguments.
241///
242/// \param S The semantic analysis object.
243///
244/// \param Init The initializer to instantiate.
245///
246/// \param TemplateArgs Template arguments to be substituted into the
247/// initializer.
248///
249/// \param NewArgs Will be filled in with the instantiation arguments.
250///
251/// \returns true if an error occurred, false otherwise
252static bool InstantiateInitializer(Sema &S, Expr *Init,
253                            const MultiLevelTemplateArgumentList &TemplateArgs,
254                                   SourceLocation &LParenLoc,
255                                   ASTOwningVector<Expr*> &NewArgs,
256                                   SourceLocation &RParenLoc) {
257  NewArgs.clear();
258  LParenLoc = SourceLocation();
259  RParenLoc = SourceLocation();
260
261  if (!Init)
262    return false;
263
264  if (ExprWithCleanups *ExprTemp = dyn_cast<ExprWithCleanups>(Init))
265    Init = ExprTemp->getSubExpr();
266
267  while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init))
268    Init = Binder->getSubExpr();
269
270  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
271    Init = ICE->getSubExprAsWritten();
272
273  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
274    LParenLoc = ParenList->getLParenLoc();
275    RParenLoc = ParenList->getRParenLoc();
276    return S.SubstExprs(ParenList->getExprs(), ParenList->getNumExprs(),
277                        true, TemplateArgs, NewArgs);
278  }
279
280  if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) {
281    if (!isa<CXXTemporaryObjectExpr>(Construct)) {
282      if (S.SubstExprs(Construct->getArgs(), Construct->getNumArgs(), true,
283                       TemplateArgs, NewArgs))
284        return true;
285
286      // FIXME: Fake locations!
287      LParenLoc = S.PP.getLocForEndOfToken(Init->getLocStart());
288      RParenLoc = LParenLoc;
289      return false;
290    }
291  }
292
293  ExprResult Result = S.SubstExpr(Init, TemplateArgs);
294  if (Result.isInvalid())
295    return true;
296
297  NewArgs.push_back(Result.takeAs<Expr>());
298  return false;
299}
300
301Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
302  // If this is the variable for an anonymous struct or union,
303  // instantiate the anonymous struct/union type first.
304  if (const RecordType *RecordTy = D->getType()->getAs<RecordType>())
305    if (RecordTy->getDecl()->isAnonymousStructOrUnion())
306      if (!VisitCXXRecordDecl(cast<CXXRecordDecl>(RecordTy->getDecl())))
307        return 0;
308
309  // Do substitution on the type of the declaration
310  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
311                                         TemplateArgs,
312                                         D->getTypeSpecStartLoc(),
313                                         D->getDeclName());
314  if (!DI)
315    return 0;
316
317  if (DI->getType()->isFunctionType()) {
318    SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
319      << D->isStaticDataMember() << DI->getType();
320    return 0;
321  }
322
323  // Build the instantiated declaration
324  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
325                                 D->getInnerLocStart(),
326                                 D->getLocation(), D->getIdentifier(),
327                                 DI->getType(), DI,
328                                 D->getStorageClass(),
329                                 D->getStorageClassAsWritten());
330  Var->setThreadSpecified(D->isThreadSpecified());
331  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
332  Var->setCXXForRangeDecl(D->isCXXForRangeDecl());
333
334  // Substitute the nested name specifier, if any.
335  if (SubstQualifier(D, Var))
336    return 0;
337
338  // If we are instantiating a static data member defined
339  // out-of-line, the instantiation will have the same lexical
340  // context (which will be a namespace scope) as the template.
341  if (D->isOutOfLine())
342    Var->setLexicalDeclContext(D->getLexicalDeclContext());
343
344  Var->setAccess(D->getAccess());
345
346  if (!D->isStaticDataMember()) {
347    Var->setUsed(D->isUsed(false));
348    Var->setReferenced(D->isReferenced());
349  }
350
351  // FIXME: In theory, we could have a previous declaration for variables that
352  // are not static data members.
353  bool Redeclaration = false;
354  // FIXME: having to fake up a LookupResult is dumb.
355  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
356                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
357  if (D->isStaticDataMember())
358    SemaRef.LookupQualifiedName(Previous, Owner, false);
359  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
360
361  if (D->isOutOfLine()) {
362    if (!D->isStaticDataMember())
363      D->getLexicalDeclContext()->addDecl(Var);
364    Owner->makeDeclVisibleInContext(Var);
365  } else {
366    Owner->addDecl(Var);
367    if (Owner->isFunctionOrMethod())
368      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Var);
369  }
370  SemaRef.InstantiateAttrs(TemplateArgs, D, Var);
371
372  // Link instantiations of static data members back to the template from
373  // which they were instantiated.
374  if (Var->isStaticDataMember())
375    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
376                                                     TSK_ImplicitInstantiation);
377
378  if (Var->getAnyInitializer()) {
379    // We already have an initializer in the class.
380  } else if (D->getInit()) {
381    if (Var->isStaticDataMember() && !D->isOutOfLine())
382      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
383    else
384      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
385
386    // Instantiate the initializer.
387    SourceLocation LParenLoc, RParenLoc;
388    ASTOwningVector<Expr*> InitArgs(SemaRef);
389    if (!InstantiateInitializer(SemaRef, D->getInit(), TemplateArgs, LParenLoc,
390                                InitArgs, RParenLoc)) {
391      bool TypeMayContainAuto = true;
392      // Attach the initializer to the declaration, if we have one.
393      if (InitArgs.size() == 0)
394        SemaRef.ActOnUninitializedDecl(Var, TypeMayContainAuto);
395      else if (D->hasCXXDirectInitializer()) {
396        // Add the direct initializer to the declaration.
397        SemaRef.AddCXXDirectInitializerToDecl(Var,
398                                              LParenLoc,
399                                              move_arg(InitArgs),
400                                              RParenLoc,
401                                              TypeMayContainAuto);
402      } else {
403        assert(InitArgs.size() == 1);
404        Expr *Init = InitArgs.take()[0];
405        SemaRef.AddInitializerToDecl(Var, Init, false, TypeMayContainAuto);
406      }
407    } else {
408      // FIXME: Not too happy about invalidating the declaration
409      // because of a bogus initializer.
410      Var->setInvalidDecl();
411    }
412
413    SemaRef.PopExpressionEvaluationContext();
414  } else if ((!Var->isStaticDataMember() || Var->isOutOfLine()) &&
415             !Var->isCXXForRangeDecl())
416    SemaRef.ActOnUninitializedDecl(Var, false);
417
418  // Diagnose unused local variables.
419  if (!Var->isInvalidDecl() && Owner->isFunctionOrMethod() && !Var->isUsed())
420    SemaRef.DiagnoseUnusedDecl(Var);
421
422  return Var;
423}
424
425Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
426  AccessSpecDecl* AD
427    = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
428                             D->getAccessSpecifierLoc(), D->getColonLoc());
429  Owner->addHiddenDecl(AD);
430  return AD;
431}
432
433Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
434  bool Invalid = false;
435  TypeSourceInfo *DI = D->getTypeSourceInfo();
436  if (DI->getType()->isDependentType() ||
437      DI->getType()->isVariablyModifiedType())  {
438    DI = SemaRef.SubstType(DI, TemplateArgs,
439                           D->getLocation(), D->getDeclName());
440    if (!DI) {
441      DI = D->getTypeSourceInfo();
442      Invalid = true;
443    } else if (DI->getType()->isFunctionType()) {
444      // C++ [temp.arg.type]p3:
445      //   If a declaration acquires a function type through a type
446      //   dependent on a template-parameter and this causes a
447      //   declaration that does not use the syntactic form of a
448      //   function declarator to have function type, the program is
449      //   ill-formed.
450      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
451        << DI->getType();
452      Invalid = true;
453    }
454  } else {
455    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
456  }
457
458  Expr *BitWidth = D->getBitWidth();
459  if (Invalid)
460    BitWidth = 0;
461  else if (BitWidth) {
462    // The bit-width expression is not potentially evaluated.
463    EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
464
465    ExprResult InstantiatedBitWidth
466      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
467    if (InstantiatedBitWidth.isInvalid()) {
468      Invalid = true;
469      BitWidth = 0;
470    } else
471      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
472  }
473
474  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
475                                            DI->getType(), DI,
476                                            cast<RecordDecl>(Owner),
477                                            D->getLocation(),
478                                            D->isMutable(),
479                                            BitWidth,
480                                            D->hasInClassInitializer(),
481                                            D->getTypeSpecStartLoc(),
482                                            D->getAccess(),
483                                            0);
484  if (!Field) {
485    cast<Decl>(Owner)->setInvalidDecl();
486    return 0;
487  }
488
489  SemaRef.InstantiateAttrs(TemplateArgs, D, Field);
490
491  if (Invalid)
492    Field->setInvalidDecl();
493
494  if (!Field->getDeclName()) {
495    // Keep track of where this decl came from.
496    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
497  }
498  if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
499    if (Parent->isAnonymousStructOrUnion() &&
500        Parent->getRedeclContext()->isFunctionOrMethod())
501      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
502  }
503
504  Field->setImplicit(D->isImplicit());
505  Field->setAccess(D->getAccess());
506  Owner->addDecl(Field);
507
508  return Field;
509}
510
511Decl *TemplateDeclInstantiator::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
512  NamedDecl **NamedChain =
513    new (SemaRef.Context)NamedDecl*[D->getChainingSize()];
514
515  int i = 0;
516  for (IndirectFieldDecl::chain_iterator PI =
517       D->chain_begin(), PE = D->chain_end();
518       PI != PE; ++PI) {
519    NamedDecl *Next = SemaRef.FindInstantiatedDecl(D->getLocation(), *PI,
520                                              TemplateArgs);
521    if (!Next)
522      return 0;
523
524    NamedChain[i++] = Next;
525  }
526
527  QualType T = cast<FieldDecl>(NamedChain[i-1])->getType();
528  IndirectFieldDecl* IndirectField
529    = IndirectFieldDecl::Create(SemaRef.Context, Owner, D->getLocation(),
530                                D->getIdentifier(), T,
531                                NamedChain, D->getChainingSize());
532
533
534  IndirectField->setImplicit(D->isImplicit());
535  IndirectField->setAccess(D->getAccess());
536  Owner->addDecl(IndirectField);
537  return IndirectField;
538}
539
540Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
541  // Handle friend type expressions by simply substituting template
542  // parameters into the pattern type and checking the result.
543  if (TypeSourceInfo *Ty = D->getFriendType()) {
544    TypeSourceInfo *InstTy;
545    // If this is an unsupported friend, don't bother substituting template
546    // arguments into it. The actual type referred to won't be used by any
547    // parts of Clang, and may not be valid for instantiating. Just use the
548    // same info for the instantiated friend.
549    if (D->isUnsupportedFriend()) {
550      InstTy = Ty;
551    } else {
552      InstTy = SemaRef.SubstType(Ty, TemplateArgs,
553                                 D->getLocation(), DeclarationName());
554    }
555    if (!InstTy)
556      return 0;
557
558    FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getFriendLoc(), InstTy);
559    if (!FD)
560      return 0;
561
562    FD->setAccess(AS_public);
563    FD->setUnsupportedFriend(D->isUnsupportedFriend());
564    Owner->addDecl(FD);
565    return FD;
566  }
567
568  NamedDecl *ND = D->getFriendDecl();
569  assert(ND && "friend decl must be a decl or a type!");
570
571  // All of the Visit implementations for the various potential friend
572  // declarations have to be carefully written to work for friend
573  // objects, with the most important detail being that the target
574  // decl should almost certainly not be placed in Owner.
575  Decl *NewND = Visit(ND);
576  if (!NewND) return 0;
577
578  FriendDecl *FD =
579    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
580                       cast<NamedDecl>(NewND), D->getFriendLoc());
581  FD->setAccess(AS_public);
582  FD->setUnsupportedFriend(D->isUnsupportedFriend());
583  Owner->addDecl(FD);
584  return FD;
585}
586
587Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
588  Expr *AssertExpr = D->getAssertExpr();
589
590  // The expression in a static assertion is not potentially evaluated.
591  EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
592
593  ExprResult InstantiatedAssertExpr
594    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
595  if (InstantiatedAssertExpr.isInvalid())
596    return 0;
597
598  ExprResult Message(D->getMessage());
599  D->getMessage();
600  return SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
601                                              InstantiatedAssertExpr.get(),
602                                              Message.get(),
603                                              D->getRParenLoc());
604}
605
606Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
607  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
608                                    D->getLocation(), D->getIdentifier(),
609                                    /*PrevDecl=*/0, D->isScoped(),
610                                    D->isScopedUsingClassTag(), D->isFixed());
611  if (D->isFixed()) {
612    if (TypeSourceInfo* TI = D->getIntegerTypeSourceInfo()) {
613      // If we have type source information for the underlying type, it means it
614      // has been explicitly set by the user. Perform substitution on it before
615      // moving on.
616      SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
617      Enum->setIntegerTypeSourceInfo(SemaRef.SubstType(TI,
618                                                       TemplateArgs,
619                                                       UnderlyingLoc,
620                                                       DeclarationName()));
621
622      if (!Enum->getIntegerTypeSourceInfo())
623        Enum->setIntegerType(SemaRef.Context.IntTy);
624    }
625    else {
626      assert(!D->getIntegerType()->isDependentType()
627             && "Dependent type without type source info");
628      Enum->setIntegerType(D->getIntegerType());
629    }
630  }
631
632  SemaRef.InstantiateAttrs(TemplateArgs, D, Enum);
633
634  Enum->setInstantiationOfMemberEnum(D);
635  Enum->setAccess(D->getAccess());
636  if (SubstQualifier(D, Enum)) return 0;
637  Owner->addDecl(Enum);
638  Enum->startDefinition();
639
640  if (D->getDeclContext()->isFunctionOrMethod())
641    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
642
643  llvm::SmallVector<Decl*, 4> Enumerators;
644
645  EnumConstantDecl *LastEnumConst = 0;
646  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
647         ECEnd = D->enumerator_end();
648       EC != ECEnd; ++EC) {
649    // The specified value for the enumerator.
650    ExprResult Value = SemaRef.Owned((Expr *)0);
651    if (Expr *UninstValue = EC->getInitExpr()) {
652      // The enumerator's value expression is not potentially evaluated.
653      EnterExpressionEvaluationContext Unevaluated(SemaRef,
654                                                   Sema::Unevaluated);
655
656      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
657    }
658
659    // Drop the initial value and continue.
660    bool isInvalid = false;
661    if (Value.isInvalid()) {
662      Value = SemaRef.Owned((Expr *)0);
663      isInvalid = true;
664    }
665
666    EnumConstantDecl *EnumConst
667      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
668                                  EC->getLocation(), EC->getIdentifier(),
669                                  Value.get());
670
671    if (isInvalid) {
672      if (EnumConst)
673        EnumConst->setInvalidDecl();
674      Enum->setInvalidDecl();
675    }
676
677    if (EnumConst) {
678      SemaRef.InstantiateAttrs(TemplateArgs, *EC, EnumConst);
679
680      EnumConst->setAccess(Enum->getAccess());
681      Enum->addDecl(EnumConst);
682      Enumerators.push_back(EnumConst);
683      LastEnumConst = EnumConst;
684
685      if (D->getDeclContext()->isFunctionOrMethod()) {
686        // If the enumeration is within a function or method, record the enum
687        // constant as a local.
688        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
689      }
690    }
691  }
692
693  // FIXME: Fixup LBraceLoc and RBraceLoc
694  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
695  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
696                        Enum,
697                        Enumerators.data(), Enumerators.size(),
698                        0, 0);
699
700  return Enum;
701}
702
703Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
704  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
705  return 0;
706}
707
708Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
709  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
710
711  // Create a local instantiation scope for this class template, which
712  // will contain the instantiations of the template parameters.
713  LocalInstantiationScope Scope(SemaRef);
714  TemplateParameterList *TempParams = D->getTemplateParameters();
715  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
716  if (!InstParams)
717    return NULL;
718
719  CXXRecordDecl *Pattern = D->getTemplatedDecl();
720
721  // Instantiate the qualifier.  We have to do this first in case
722  // we're a friend declaration, because if we are then we need to put
723  // the new declaration in the appropriate context.
724  NestedNameSpecifierLoc QualifierLoc = Pattern->getQualifierLoc();
725  if (QualifierLoc) {
726    QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
727                                                       TemplateArgs);
728    if (!QualifierLoc)
729      return 0;
730  }
731
732  CXXRecordDecl *PrevDecl = 0;
733  ClassTemplateDecl *PrevClassTemplate = 0;
734
735  if (!isFriend && Pattern->getPreviousDeclaration()) {
736    DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
737    if (Found.first != Found.second) {
738      PrevClassTemplate = dyn_cast<ClassTemplateDecl>(*Found.first);
739      if (PrevClassTemplate)
740        PrevDecl = PrevClassTemplate->getTemplatedDecl();
741    }
742  }
743
744  // If this isn't a friend, then it's a member template, in which
745  // case we just want to build the instantiation in the
746  // specialization.  If it is a friend, we want to build it in
747  // the appropriate context.
748  DeclContext *DC = Owner;
749  if (isFriend) {
750    if (QualifierLoc) {
751      CXXScopeSpec SS;
752      SS.Adopt(QualifierLoc);
753      DC = SemaRef.computeDeclContext(SS);
754      if (!DC) return 0;
755    } else {
756      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
757                                           Pattern->getDeclContext(),
758                                           TemplateArgs);
759    }
760
761    // Look for a previous declaration of the template in the owning
762    // context.
763    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
764                   Sema::LookupOrdinaryName, Sema::ForRedeclaration);
765    SemaRef.LookupQualifiedName(R, DC);
766
767    if (R.isSingleResult()) {
768      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
769      if (PrevClassTemplate)
770        PrevDecl = PrevClassTemplate->getTemplatedDecl();
771    }
772
773    if (!PrevClassTemplate && QualifierLoc) {
774      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
775        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
776        << QualifierLoc.getSourceRange();
777      return 0;
778    }
779
780    bool AdoptedPreviousTemplateParams = false;
781    if (PrevClassTemplate) {
782      bool Complain = true;
783
784      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
785      // template for struct std::tr1::__detail::_Map_base, where the
786      // template parameters of the friend declaration don't match the
787      // template parameters of the original declaration. In this one
788      // case, we don't complain about the ill-formed friend
789      // declaration.
790      if (isFriend && Pattern->getIdentifier() &&
791          Pattern->getIdentifier()->isStr("_Map_base") &&
792          DC->isNamespace() &&
793          cast<NamespaceDecl>(DC)->getIdentifier() &&
794          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
795        DeclContext *DCParent = DC->getParent();
796        if (DCParent->isNamespace() &&
797            cast<NamespaceDecl>(DCParent)->getIdentifier() &&
798            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
799          DeclContext *DCParent2 = DCParent->getParent();
800          if (DCParent2->isNamespace() &&
801              cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
802              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
803              DCParent2->getParent()->isTranslationUnit())
804            Complain = false;
805        }
806      }
807
808      TemplateParameterList *PrevParams
809        = PrevClassTemplate->getTemplateParameters();
810
811      // Make sure the parameter lists match.
812      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
813                                                  Complain,
814                                                  Sema::TPL_TemplateMatch)) {
815        if (Complain)
816          return 0;
817
818        AdoptedPreviousTemplateParams = true;
819        InstParams = PrevParams;
820      }
821
822      // Do some additional validation, then merge default arguments
823      // from the existing declarations.
824      if (!AdoptedPreviousTemplateParams &&
825          SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
826                                             Sema::TPC_ClassTemplate))
827        return 0;
828    }
829  }
830
831  CXXRecordDecl *RecordInst
832    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
833                            Pattern->getLocStart(), Pattern->getLocation(),
834                            Pattern->getIdentifier(), PrevDecl,
835                            /*DelayTypeCreation=*/true);
836
837  if (QualifierLoc)
838    RecordInst->setQualifierInfo(QualifierLoc);
839
840  ClassTemplateDecl *Inst
841    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
842                                D->getIdentifier(), InstParams, RecordInst,
843                                PrevClassTemplate);
844  RecordInst->setDescribedClassTemplate(Inst);
845
846  if (isFriend) {
847    if (PrevClassTemplate)
848      Inst->setAccess(PrevClassTemplate->getAccess());
849    else
850      Inst->setAccess(D->getAccess());
851
852    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
853    // TODO: do we want to track the instantiation progeny of this
854    // friend target decl?
855  } else {
856    Inst->setAccess(D->getAccess());
857    if (!PrevClassTemplate)
858      Inst->setInstantiatedFromMemberTemplate(D);
859  }
860
861  // Trigger creation of the type for the instantiation.
862  SemaRef.Context.getInjectedClassNameType(RecordInst,
863                                    Inst->getInjectedClassNameSpecialization());
864
865  // Finish handling of friends.
866  if (isFriend) {
867    DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
868    return Inst;
869  }
870
871  Owner->addDecl(Inst);
872
873  if (!PrevClassTemplate) {
874    // Queue up any out-of-line partial specializations of this member
875    // class template; the client will force their instantiation once
876    // the enclosing class has been instantiated.
877    llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
878    D->getPartialSpecializations(PartialSpecs);
879    for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
880      if (PartialSpecs[I]->isOutOfLine())
881        OutOfLinePartialSpecs.push_back(std::make_pair(Inst, PartialSpecs[I]));
882  }
883
884  return Inst;
885}
886
887Decl *
888TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
889                                   ClassTemplatePartialSpecializationDecl *D) {
890  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
891
892  // Lookup the already-instantiated declaration in the instantiation
893  // of the class template and return that.
894  DeclContext::lookup_result Found
895    = Owner->lookup(ClassTemplate->getDeclName());
896  if (Found.first == Found.second)
897    return 0;
898
899  ClassTemplateDecl *InstClassTemplate
900    = dyn_cast<ClassTemplateDecl>(*Found.first);
901  if (!InstClassTemplate)
902    return 0;
903
904  if (ClassTemplatePartialSpecializationDecl *Result
905        = InstClassTemplate->findPartialSpecInstantiatedFromMember(D))
906    return Result;
907
908  return InstantiateClassTemplatePartialSpecialization(InstClassTemplate, D);
909}
910
911Decl *
912TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
913  // Create a local instantiation scope for this function template, which
914  // will contain the instantiations of the template parameters and then get
915  // merged with the local instantiation scope for the function template
916  // itself.
917  LocalInstantiationScope Scope(SemaRef);
918
919  TemplateParameterList *TempParams = D->getTemplateParameters();
920  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
921  if (!InstParams)
922    return NULL;
923
924  FunctionDecl *Instantiated = 0;
925  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
926    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
927                                                                 InstParams));
928  else
929    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
930                                                          D->getTemplatedDecl(),
931                                                                InstParams));
932
933  if (!Instantiated)
934    return 0;
935
936  Instantiated->setAccess(D->getAccess());
937
938  // Link the instantiated function template declaration to the function
939  // template from which it was instantiated.
940  FunctionTemplateDecl *InstTemplate
941    = Instantiated->getDescribedFunctionTemplate();
942  InstTemplate->setAccess(D->getAccess());
943  assert(InstTemplate &&
944         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
945
946  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
947
948  // Link the instantiation back to the pattern *unless* this is a
949  // non-definition friend declaration.
950  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
951      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
952    InstTemplate->setInstantiatedFromMemberTemplate(D);
953
954  // Make declarations visible in the appropriate context.
955  if (!isFriend)
956    Owner->addDecl(InstTemplate);
957
958  return InstTemplate;
959}
960
961Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
962  CXXRecordDecl *PrevDecl = 0;
963  if (D->isInjectedClassName())
964    PrevDecl = cast<CXXRecordDecl>(Owner);
965  else if (D->getPreviousDeclaration()) {
966    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
967                                                   D->getPreviousDeclaration(),
968                                                   TemplateArgs);
969    if (!Prev) return 0;
970    PrevDecl = cast<CXXRecordDecl>(Prev);
971  }
972
973  CXXRecordDecl *Record
974    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
975                            D->getLocStart(), D->getLocation(),
976                            D->getIdentifier(), PrevDecl);
977
978  // Substitute the nested name specifier, if any.
979  if (SubstQualifier(D, Record))
980    return 0;
981
982  Record->setImplicit(D->isImplicit());
983  // FIXME: Check against AS_none is an ugly hack to work around the issue that
984  // the tag decls introduced by friend class declarations don't have an access
985  // specifier. Remove once this area of the code gets sorted out.
986  if (D->getAccess() != AS_none)
987    Record->setAccess(D->getAccess());
988  if (!D->isInjectedClassName())
989    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
990
991  // If the original function was part of a friend declaration,
992  // inherit its namespace state.
993  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
994    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
995
996  // Make sure that anonymous structs and unions are recorded.
997  if (D->isAnonymousStructOrUnion()) {
998    Record->setAnonymousStructOrUnion(true);
999    if (Record->getDeclContext()->getRedeclContext()->isFunctionOrMethod())
1000      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
1001  }
1002
1003  Owner->addDecl(Record);
1004  return Record;
1005}
1006
1007/// Normal class members are of more specific types and therefore
1008/// don't make it here.  This function serves two purposes:
1009///   1) instantiating function templates
1010///   2) substituting friend declarations
1011/// FIXME: preserve function definitions in case #2
1012Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
1013                                       TemplateParameterList *TemplateParams) {
1014  // Check whether there is already a function template specialization for
1015  // this declaration.
1016  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1017  void *InsertPos = 0;
1018  if (FunctionTemplate && !TemplateParams) {
1019    std::pair<const TemplateArgument *, unsigned> Innermost
1020      = TemplateArgs.getInnermost();
1021
1022    FunctionDecl *SpecFunc
1023      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
1024                                             InsertPos);
1025
1026    // If we already have a function template specialization, return it.
1027    if (SpecFunc)
1028      return SpecFunc;
1029  }
1030
1031  bool isFriend;
1032  if (FunctionTemplate)
1033    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1034  else
1035    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1036
1037  bool MergeWithParentScope = (TemplateParams != 0) ||
1038    Owner->isFunctionOrMethod() ||
1039    !(isa<Decl>(Owner) &&
1040      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1041  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1042
1043  llvm::SmallVector<ParmVarDecl *, 4> Params;
1044  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1045  TInfo = SubstFunctionType(D, Params);
1046  if (!TInfo)
1047    return 0;
1048  QualType T = TInfo->getType();
1049
1050  NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1051  if (QualifierLoc) {
1052    QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1053                                                       TemplateArgs);
1054    if (!QualifierLoc)
1055      return 0;
1056  }
1057
1058  // If we're instantiating a local function declaration, put the result
1059  // in the owner;  otherwise we need to find the instantiated context.
1060  DeclContext *DC;
1061  if (D->getDeclContext()->isFunctionOrMethod())
1062    DC = Owner;
1063  else if (isFriend && QualifierLoc) {
1064    CXXScopeSpec SS;
1065    SS.Adopt(QualifierLoc);
1066    DC = SemaRef.computeDeclContext(SS);
1067    if (!DC) return 0;
1068  } else {
1069    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1070                                         TemplateArgs);
1071  }
1072
1073  FunctionDecl *Function =
1074      FunctionDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
1075                           D->getLocation(), D->getDeclName(), T, TInfo,
1076                           D->getStorageClass(), D->getStorageClassAsWritten(),
1077                           D->isInlineSpecified(), D->hasWrittenPrototype());
1078
1079  if (QualifierLoc)
1080    Function->setQualifierInfo(QualifierLoc);
1081
1082  DeclContext *LexicalDC = Owner;
1083  if (!isFriend && D->isOutOfLine()) {
1084    assert(D->getDeclContext()->isFileContext());
1085    LexicalDC = D->getDeclContext();
1086  }
1087
1088  Function->setLexicalDeclContext(LexicalDC);
1089
1090  // Attach the parameters
1091  for (unsigned P = 0; P < Params.size(); ++P)
1092    if (Params[P])
1093      Params[P]->setOwningFunction(Function);
1094  Function->setParams(Params.data(), Params.size());
1095
1096  SourceLocation InstantiateAtPOI;
1097  if (TemplateParams) {
1098    // Our resulting instantiation is actually a function template, since we
1099    // are substituting only the outer template parameters. For example, given
1100    //
1101    //   template<typename T>
1102    //   struct X {
1103    //     template<typename U> friend void f(T, U);
1104    //   };
1105    //
1106    //   X<int> x;
1107    //
1108    // We are instantiating the friend function template "f" within X<int>,
1109    // which means substituting int for T, but leaving "f" as a friend function
1110    // template.
1111    // Build the function template itself.
1112    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1113                                                    Function->getLocation(),
1114                                                    Function->getDeclName(),
1115                                                    TemplateParams, Function);
1116    Function->setDescribedFunctionTemplate(FunctionTemplate);
1117
1118    FunctionTemplate->setLexicalDeclContext(LexicalDC);
1119
1120    if (isFriend && D->isThisDeclarationADefinition()) {
1121      // TODO: should we remember this connection regardless of whether
1122      // the friend declaration provided a body?
1123      FunctionTemplate->setInstantiatedFromMemberTemplate(
1124                                           D->getDescribedFunctionTemplate());
1125    }
1126  } else if (FunctionTemplate) {
1127    // Record this function template specialization.
1128    std::pair<const TemplateArgument *, unsigned> Innermost
1129      = TemplateArgs.getInnermost();
1130    Function->setFunctionTemplateSpecialization(FunctionTemplate,
1131                            TemplateArgumentList::CreateCopy(SemaRef.Context,
1132                                                             Innermost.first,
1133                                                             Innermost.second),
1134                                                InsertPos);
1135  } else if (isFriend && D->isThisDeclarationADefinition()) {
1136    // TODO: should we remember this connection regardless of whether
1137    // the friend declaration provided a body?
1138    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1139  }
1140
1141  if (InitFunctionInstantiation(Function, D))
1142    Function->setInvalidDecl();
1143
1144  bool Redeclaration = false;
1145  bool isExplicitSpecialization = false;
1146
1147  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1148                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1149
1150  if (DependentFunctionTemplateSpecializationInfo *Info
1151        = D->getDependentSpecializationInfo()) {
1152    assert(isFriend && "non-friend has dependent specialization info?");
1153
1154    // This needs to be set now for future sanity.
1155    Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1156
1157    // Instantiate the explicit template arguments.
1158    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1159                                          Info->getRAngleLoc());
1160    if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(),
1161                      ExplicitArgs, TemplateArgs))
1162      return 0;
1163
1164    // Map the candidate templates to their instantiations.
1165    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1166      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1167                                                Info->getTemplate(I),
1168                                                TemplateArgs);
1169      if (!Temp) return 0;
1170
1171      Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1172    }
1173
1174    if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1175                                                    &ExplicitArgs,
1176                                                    Previous))
1177      Function->setInvalidDecl();
1178
1179    isExplicitSpecialization = true;
1180
1181  } else if (TemplateParams || !FunctionTemplate) {
1182    // Look only into the namespace where the friend would be declared to
1183    // find a previous declaration. This is the innermost enclosing namespace,
1184    // as described in ActOnFriendFunctionDecl.
1185    SemaRef.LookupQualifiedName(Previous, DC);
1186
1187    // In C++, the previous declaration we find might be a tag type
1188    // (class or enum). In this case, the new declaration will hide the
1189    // tag type. Note that this does does not apply if we're declaring a
1190    // typedef (C++ [dcl.typedef]p4).
1191    if (Previous.isSingleTagDecl())
1192      Previous.clear();
1193  }
1194
1195  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1196                                   isExplicitSpecialization, Redeclaration);
1197
1198  NamedDecl *PrincipalDecl = (TemplateParams
1199                              ? cast<NamedDecl>(FunctionTemplate)
1200                              : Function);
1201
1202  // If the original function was part of a friend declaration,
1203  // inherit its namespace state and add it to the owner.
1204  if (isFriend) {
1205    NamedDecl *PrevDecl;
1206    if (TemplateParams)
1207      PrevDecl = FunctionTemplate->getPreviousDeclaration();
1208    else
1209      PrevDecl = Function->getPreviousDeclaration();
1210
1211    PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0);
1212    DC->makeDeclVisibleInContext(PrincipalDecl, /*Recoverable=*/ false);
1213
1214    bool queuedInstantiation = false;
1215
1216    if (!SemaRef.getLangOptions().CPlusPlus0x &&
1217        D->isThisDeclarationADefinition()) {
1218      // Check for a function body.
1219      const FunctionDecl *Definition = 0;
1220      if (Function->isDefined(Definition) &&
1221          Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1222        SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1223          << Function->getDeclName();
1224        SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1225        Function->setInvalidDecl();
1226      }
1227      // Check for redefinitions due to other instantiations of this or
1228      // a similar friend function.
1229      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1230                                           REnd = Function->redecls_end();
1231                R != REnd; ++R) {
1232        if (*R == Function)
1233          continue;
1234        switch (R->getFriendObjectKind()) {
1235        case Decl::FOK_None:
1236          if (!queuedInstantiation && R->isUsed(false)) {
1237            if (MemberSpecializationInfo *MSInfo
1238                = Function->getMemberSpecializationInfo()) {
1239              if (MSInfo->getPointOfInstantiation().isInvalid()) {
1240                SourceLocation Loc = R->getLocation(); // FIXME
1241                MSInfo->setPointOfInstantiation(Loc);
1242                SemaRef.PendingLocalImplicitInstantiations.push_back(
1243                                                 std::make_pair(Function, Loc));
1244                queuedInstantiation = true;
1245              }
1246            }
1247          }
1248          break;
1249        default:
1250          if (const FunctionDecl *RPattern
1251              = R->getTemplateInstantiationPattern())
1252            if (RPattern->isDefined(RPattern)) {
1253              SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1254                << Function->getDeclName();
1255              SemaRef.Diag(R->getLocation(), diag::note_previous_definition);
1256              Function->setInvalidDecl();
1257              break;
1258            }
1259        }
1260      }
1261    }
1262  }
1263
1264  if (Function->isOverloadedOperator() && !DC->isRecord() &&
1265      PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1266    PrincipalDecl->setNonMemberOperator();
1267
1268  assert(!D->isDefaulted() && "only methods should be defaulted");
1269  return Function;
1270}
1271
1272Decl *
1273TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1274                                      TemplateParameterList *TemplateParams) {
1275  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1276  void *InsertPos = 0;
1277  if (FunctionTemplate && !TemplateParams) {
1278    // We are creating a function template specialization from a function
1279    // template. Check whether there is already a function template
1280    // specialization for this particular set of template arguments.
1281    std::pair<const TemplateArgument *, unsigned> Innermost
1282      = TemplateArgs.getInnermost();
1283
1284    FunctionDecl *SpecFunc
1285      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
1286                                             InsertPos);
1287
1288    // If we already have a function template specialization, return it.
1289    if (SpecFunc)
1290      return SpecFunc;
1291  }
1292
1293  bool isFriend;
1294  if (FunctionTemplate)
1295    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1296  else
1297    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1298
1299  bool MergeWithParentScope = (TemplateParams != 0) ||
1300    !(isa<Decl>(Owner) &&
1301      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1302  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1303
1304  // Instantiate enclosing template arguments for friends.
1305  llvm::SmallVector<TemplateParameterList *, 4> TempParamLists;
1306  unsigned NumTempParamLists = 0;
1307  if (isFriend && (NumTempParamLists = D->getNumTemplateParameterLists())) {
1308    TempParamLists.set_size(NumTempParamLists);
1309    for (unsigned I = 0; I != NumTempParamLists; ++I) {
1310      TemplateParameterList *TempParams = D->getTemplateParameterList(I);
1311      TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1312      if (!InstParams)
1313        return NULL;
1314      TempParamLists[I] = InstParams;
1315    }
1316  }
1317
1318  llvm::SmallVector<ParmVarDecl *, 4> Params;
1319  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1320  TInfo = SubstFunctionType(D, Params);
1321  if (!TInfo)
1322    return 0;
1323  QualType T = TInfo->getType();
1324
1325  // \brief If the type of this function, after ignoring parentheses,
1326  // is not *directly* a function type, then we're instantiating a function
1327  // that was declared via a typedef, e.g.,
1328  //
1329  //   typedef int functype(int, int);
1330  //   functype func;
1331  //
1332  // In this case, we'll just go instantiate the ParmVarDecls that we
1333  // synthesized in the method declaration.
1334  if (!isa<FunctionProtoType>(T.IgnoreParens())) {
1335    assert(!Params.size() && "Instantiating type could not yield parameters");
1336    llvm::SmallVector<QualType, 4> ParamTypes;
1337    if (SemaRef.SubstParmTypes(D->getLocation(), D->param_begin(),
1338                               D->getNumParams(), TemplateArgs, ParamTypes,
1339                               &Params))
1340      return 0;
1341  }
1342
1343  NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1344  if (QualifierLoc) {
1345    QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1346                                                 TemplateArgs);
1347    if (!QualifierLoc)
1348      return 0;
1349  }
1350
1351  DeclContext *DC = Owner;
1352  if (isFriend) {
1353    if (QualifierLoc) {
1354      CXXScopeSpec SS;
1355      SS.Adopt(QualifierLoc);
1356      DC = SemaRef.computeDeclContext(SS);
1357
1358      if (DC && SemaRef.RequireCompleteDeclContext(SS, DC))
1359        return 0;
1360    } else {
1361      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1362                                           D->getDeclContext(),
1363                                           TemplateArgs);
1364    }
1365    if (!DC) return 0;
1366  }
1367
1368  // Build the instantiated method declaration.
1369  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1370  CXXMethodDecl *Method = 0;
1371
1372  SourceLocation StartLoc = D->getInnerLocStart();
1373  DeclarationNameInfo NameInfo
1374    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1375  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1376    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1377                                        StartLoc, NameInfo, T, TInfo,
1378                                        Constructor->isExplicit(),
1379                                        Constructor->isInlineSpecified(),
1380                                        false);
1381  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1382    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1383                                       StartLoc, NameInfo, T, TInfo,
1384                                       Destructor->isInlineSpecified(),
1385                                       false);
1386  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1387    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1388                                       StartLoc, NameInfo, T, TInfo,
1389                                       Conversion->isInlineSpecified(),
1390                                       Conversion->isExplicit(),
1391                                       Conversion->getLocEnd());
1392  } else {
1393    Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1394                                   StartLoc, NameInfo, T, TInfo,
1395                                   D->isStatic(),
1396                                   D->getStorageClassAsWritten(),
1397                                   D->isInlineSpecified(),
1398                                   D->getLocEnd());
1399  }
1400
1401  if (QualifierLoc)
1402    Method->setQualifierInfo(QualifierLoc);
1403
1404  if (TemplateParams) {
1405    // Our resulting instantiation is actually a function template, since we
1406    // are substituting only the outer template parameters. For example, given
1407    //
1408    //   template<typename T>
1409    //   struct X {
1410    //     template<typename U> void f(T, U);
1411    //   };
1412    //
1413    //   X<int> x;
1414    //
1415    // We are instantiating the member template "f" within X<int>, which means
1416    // substituting int for T, but leaving "f" as a member function template.
1417    // Build the function template itself.
1418    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1419                                                    Method->getLocation(),
1420                                                    Method->getDeclName(),
1421                                                    TemplateParams, Method);
1422    if (isFriend) {
1423      FunctionTemplate->setLexicalDeclContext(Owner);
1424      FunctionTemplate->setObjectOfFriendDecl(true);
1425    } else if (D->isOutOfLine())
1426      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1427    Method->setDescribedFunctionTemplate(FunctionTemplate);
1428  } else if (FunctionTemplate) {
1429    // Record this function template specialization.
1430    std::pair<const TemplateArgument *, unsigned> Innermost
1431      = TemplateArgs.getInnermost();
1432    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1433                         TemplateArgumentList::CreateCopy(SemaRef.Context,
1434                                                          Innermost.first,
1435                                                          Innermost.second),
1436                                              InsertPos);
1437  } else if (!isFriend) {
1438    // Record that this is an instantiation of a member function.
1439    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1440  }
1441
1442  // If we are instantiating a member function defined
1443  // out-of-line, the instantiation will have the same lexical
1444  // context (which will be a namespace scope) as the template.
1445  if (isFriend) {
1446    if (NumTempParamLists)
1447      Method->setTemplateParameterListsInfo(SemaRef.Context,
1448                                            NumTempParamLists,
1449                                            TempParamLists.data());
1450
1451    Method->setLexicalDeclContext(Owner);
1452    Method->setObjectOfFriendDecl(true);
1453  } else if (D->isOutOfLine())
1454    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1455
1456  // Attach the parameters
1457  for (unsigned P = 0; P < Params.size(); ++P)
1458    Params[P]->setOwningFunction(Method);
1459  Method->setParams(Params.data(), Params.size());
1460
1461  if (InitMethodInstantiation(Method, D))
1462    Method->setInvalidDecl();
1463
1464  LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
1465                        Sema::ForRedeclaration);
1466
1467  if (!FunctionTemplate || TemplateParams || isFriend) {
1468    SemaRef.LookupQualifiedName(Previous, Record);
1469
1470    // In C++, the previous declaration we find might be a tag type
1471    // (class or enum). In this case, the new declaration will hide the
1472    // tag type. Note that this does does not apply if we're declaring a
1473    // typedef (C++ [dcl.typedef]p4).
1474    if (Previous.isSingleTagDecl())
1475      Previous.clear();
1476  }
1477
1478  bool Redeclaration = false;
1479  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration);
1480
1481  if (D->isPure())
1482    SemaRef.CheckPureMethod(Method, SourceRange());
1483
1484  Method->setAccess(D->getAccess());
1485
1486  SemaRef.CheckOverrideControl(Method);
1487
1488  if (FunctionTemplate) {
1489    // If there's a function template, let our caller handle it.
1490  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1491    // Don't hide a (potentially) valid declaration with an invalid one.
1492  } else {
1493    NamedDecl *DeclToAdd = (TemplateParams
1494                            ? cast<NamedDecl>(FunctionTemplate)
1495                            : Method);
1496    if (isFriend)
1497      Record->makeDeclVisibleInContext(DeclToAdd);
1498    else
1499      Owner->addDecl(DeclToAdd);
1500  }
1501
1502  if (D->isExplicitlyDefaulted()) {
1503    SemaRef.SetDeclDefaulted(Method, Method->getLocation());
1504  } else {
1505    assert(!D->isDefaulted() &&
1506           "should not implicitly default uninstantiated function");
1507  }
1508
1509  return Method;
1510}
1511
1512Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1513  return VisitCXXMethodDecl(D);
1514}
1515
1516Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1517  return VisitCXXMethodDecl(D);
1518}
1519
1520Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1521  return VisitCXXMethodDecl(D);
1522}
1523
1524ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1525  return SemaRef.SubstParmVarDecl(D, TemplateArgs, /*indexAdjustment*/ 0,
1526                                  llvm::Optional<unsigned>());
1527}
1528
1529Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1530                                                    TemplateTypeParmDecl *D) {
1531  // TODO: don't always clone when decls are refcounted.
1532  assert(D->getTypeForDecl()->isTemplateTypeParmType());
1533
1534  TemplateTypeParmDecl *Inst =
1535    TemplateTypeParmDecl::Create(SemaRef.Context, Owner,
1536                                 D->getLocStart(), D->getLocation(),
1537                                 D->getDepth() - TemplateArgs.getNumLevels(),
1538                                 D->getIndex(), D->getIdentifier(),
1539                                 D->wasDeclaredWithTypename(),
1540                                 D->isParameterPack());
1541  Inst->setAccess(AS_public);
1542
1543  if (D->hasDefaultArgument())
1544    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1545
1546  // Introduce this template parameter's instantiation into the instantiation
1547  // scope.
1548  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1549
1550  return Inst;
1551}
1552
1553Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1554                                                 NonTypeTemplateParmDecl *D) {
1555  // Substitute into the type of the non-type template parameter.
1556  TypeLoc TL = D->getTypeSourceInfo()->getTypeLoc();
1557  llvm::SmallVector<TypeSourceInfo *, 4> ExpandedParameterPackTypesAsWritten;
1558  llvm::SmallVector<QualType, 4> ExpandedParameterPackTypes;
1559  bool IsExpandedParameterPack = false;
1560  TypeSourceInfo *DI;
1561  QualType T;
1562  bool Invalid = false;
1563
1564  if (D->isExpandedParameterPack()) {
1565    // The non-type template parameter pack is an already-expanded pack
1566    // expansion of types. Substitute into each of the expanded types.
1567    ExpandedParameterPackTypes.reserve(D->getNumExpansionTypes());
1568    ExpandedParameterPackTypesAsWritten.reserve(D->getNumExpansionTypes());
1569    for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1570      TypeSourceInfo *NewDI =SemaRef.SubstType(D->getExpansionTypeSourceInfo(I),
1571                                               TemplateArgs,
1572                                               D->getLocation(),
1573                                               D->getDeclName());
1574      if (!NewDI)
1575        return 0;
1576
1577      ExpandedParameterPackTypesAsWritten.push_back(NewDI);
1578      QualType NewT =SemaRef.CheckNonTypeTemplateParameterType(NewDI->getType(),
1579                                                              D->getLocation());
1580      if (NewT.isNull())
1581        return 0;
1582      ExpandedParameterPackTypes.push_back(NewT);
1583    }
1584
1585    IsExpandedParameterPack = true;
1586    DI = D->getTypeSourceInfo();
1587    T = DI->getType();
1588  } else if (isa<PackExpansionTypeLoc>(TL)) {
1589    // The non-type template parameter pack's type is a pack expansion of types.
1590    // Determine whether we need to expand this parameter pack into separate
1591    // types.
1592    PackExpansionTypeLoc Expansion = cast<PackExpansionTypeLoc>(TL);
1593    TypeLoc Pattern = Expansion.getPatternLoc();
1594    llvm::SmallVector<UnexpandedParameterPack, 2> Unexpanded;
1595    SemaRef.collectUnexpandedParameterPacks(Pattern, Unexpanded);
1596
1597    // Determine whether the set of unexpanded parameter packs can and should
1598    // be expanded.
1599    bool Expand = true;
1600    bool RetainExpansion = false;
1601    llvm::Optional<unsigned> OrigNumExpansions
1602      = Expansion.getTypePtr()->getNumExpansions();
1603    llvm::Optional<unsigned> NumExpansions = OrigNumExpansions;
1604    if (SemaRef.CheckParameterPacksForExpansion(Expansion.getEllipsisLoc(),
1605                                                Pattern.getSourceRange(),
1606                                                Unexpanded.data(),
1607                                                Unexpanded.size(),
1608                                                TemplateArgs,
1609                                                Expand, RetainExpansion,
1610                                                NumExpansions))
1611      return 0;
1612
1613    if (Expand) {
1614      for (unsigned I = 0; I != *NumExpansions; ++I) {
1615        Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
1616        TypeSourceInfo *NewDI = SemaRef.SubstType(Pattern, TemplateArgs,
1617                                                  D->getLocation(),
1618                                                  D->getDeclName());
1619        if (!NewDI)
1620          return 0;
1621
1622        ExpandedParameterPackTypesAsWritten.push_back(NewDI);
1623        QualType NewT = SemaRef.CheckNonTypeTemplateParameterType(
1624                                                              NewDI->getType(),
1625                                                              D->getLocation());
1626        if (NewT.isNull())
1627          return 0;
1628        ExpandedParameterPackTypes.push_back(NewT);
1629      }
1630
1631      // Note that we have an expanded parameter pack. The "type" of this
1632      // expanded parameter pack is the original expansion type, but callers
1633      // will end up using the expanded parameter pack types for type-checking.
1634      IsExpandedParameterPack = true;
1635      DI = D->getTypeSourceInfo();
1636      T = DI->getType();
1637    } else {
1638      // We cannot fully expand the pack expansion now, so substitute into the
1639      // pattern and create a new pack expansion type.
1640      Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
1641      TypeSourceInfo *NewPattern = SemaRef.SubstType(Pattern, TemplateArgs,
1642                                                     D->getLocation(),
1643                                                     D->getDeclName());
1644      if (!NewPattern)
1645        return 0;
1646
1647      DI = SemaRef.CheckPackExpansion(NewPattern, Expansion.getEllipsisLoc(),
1648                                      NumExpansions);
1649      if (!DI)
1650        return 0;
1651
1652      T = DI->getType();
1653    }
1654  } else {
1655    // Simple case: substitution into a parameter that is not a parameter pack.
1656    DI = SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
1657                           D->getLocation(), D->getDeclName());
1658    if (!DI)
1659      return 0;
1660
1661    // Check that this type is acceptable for a non-type template parameter.
1662    T = SemaRef.CheckNonTypeTemplateParameterType(DI->getType(),
1663                                                  D->getLocation());
1664    if (T.isNull()) {
1665      T = SemaRef.Context.IntTy;
1666      Invalid = true;
1667    }
1668  }
1669
1670  NonTypeTemplateParmDecl *Param;
1671  if (IsExpandedParameterPack)
1672    Param = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner,
1673                                            D->getInnerLocStart(),
1674                                            D->getLocation(),
1675                                    D->getDepth() - TemplateArgs.getNumLevels(),
1676                                            D->getPosition(),
1677                                            D->getIdentifier(), T,
1678                                            DI,
1679                                            ExpandedParameterPackTypes.data(),
1680                                            ExpandedParameterPackTypes.size(),
1681                                    ExpandedParameterPackTypesAsWritten.data());
1682  else
1683    Param = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner,
1684                                            D->getInnerLocStart(),
1685                                            D->getLocation(),
1686                                    D->getDepth() - TemplateArgs.getNumLevels(),
1687                                            D->getPosition(),
1688                                            D->getIdentifier(), T,
1689                                            D->isParameterPack(), DI);
1690
1691  Param->setAccess(AS_public);
1692  if (Invalid)
1693    Param->setInvalidDecl();
1694
1695  Param->setDefaultArgument(D->getDefaultArgument(), false);
1696
1697  // Introduce this template parameter's instantiation into the instantiation
1698  // scope.
1699  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1700  return Param;
1701}
1702
1703Decl *
1704TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1705                                                  TemplateTemplateParmDecl *D) {
1706  // Instantiate the template parameter list of the template template parameter.
1707  TemplateParameterList *TempParams = D->getTemplateParameters();
1708  TemplateParameterList *InstParams;
1709  {
1710    // Perform the actual substitution of template parameters within a new,
1711    // local instantiation scope.
1712    LocalInstantiationScope Scope(SemaRef);
1713    InstParams = SubstTemplateParams(TempParams);
1714    if (!InstParams)
1715      return NULL;
1716  }
1717
1718  // Build the template template parameter.
1719  TemplateTemplateParmDecl *Param
1720    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1721                                   D->getDepth() - TemplateArgs.getNumLevels(),
1722                                       D->getPosition(), D->isParameterPack(),
1723                                       D->getIdentifier(), InstParams);
1724  Param->setDefaultArgument(D->getDefaultArgument(), false);
1725  Param->setAccess(AS_public);
1726
1727  // Introduce this template parameter's instantiation into the instantiation
1728  // scope.
1729  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1730
1731  return Param;
1732}
1733
1734Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1735  // Using directives are never dependent (and never contain any types or
1736  // expressions), so they require no explicit instantiation work.
1737
1738  UsingDirectiveDecl *Inst
1739    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1740                                 D->getNamespaceKeyLocation(),
1741                                 D->getQualifierLoc(),
1742                                 D->getIdentLocation(),
1743                                 D->getNominatedNamespace(),
1744                                 D->getCommonAncestor());
1745  Owner->addDecl(Inst);
1746  return Inst;
1747}
1748
1749Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1750
1751  // The nested name specifier may be dependent, for example
1752  //     template <typename T> struct t {
1753  //       struct s1 { T f1(); };
1754  //       struct s2 : s1 { using s1::f1; };
1755  //     };
1756  //     template struct t<int>;
1757  // Here, in using s1::f1, s1 refers to t<T>::s1;
1758  // we need to substitute for t<int>::s1.
1759  NestedNameSpecifierLoc QualifierLoc
1760    = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
1761                                          TemplateArgs);
1762  if (!QualifierLoc)
1763    return 0;
1764
1765  // The name info is non-dependent, so no transformation
1766  // is required.
1767  DeclarationNameInfo NameInfo = D->getNameInfo();
1768
1769  // We only need to do redeclaration lookups if we're in a class
1770  // scope (in fact, it's not really even possible in non-class
1771  // scopes).
1772  bool CheckRedeclaration = Owner->isRecord();
1773
1774  LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
1775                    Sema::ForRedeclaration);
1776
1777  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1778                                       D->getUsingLocation(),
1779                                       QualifierLoc,
1780                                       NameInfo,
1781                                       D->isTypeName());
1782
1783  CXXScopeSpec SS;
1784  SS.Adopt(QualifierLoc);
1785  if (CheckRedeclaration) {
1786    Prev.setHideTags(false);
1787    SemaRef.LookupQualifiedName(Prev, Owner);
1788
1789    // Check for invalid redeclarations.
1790    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1791                                            D->isTypeName(), SS,
1792                                            D->getLocation(), Prev))
1793      NewUD->setInvalidDecl();
1794
1795  }
1796
1797  if (!NewUD->isInvalidDecl() &&
1798      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1799                                      D->getLocation()))
1800    NewUD->setInvalidDecl();
1801
1802  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1803  NewUD->setAccess(D->getAccess());
1804  Owner->addDecl(NewUD);
1805
1806  // Don't process the shadow decls for an invalid decl.
1807  if (NewUD->isInvalidDecl())
1808    return NewUD;
1809
1810  bool isFunctionScope = Owner->isFunctionOrMethod();
1811
1812  // Process the shadow decls.
1813  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1814         I != E; ++I) {
1815    UsingShadowDecl *Shadow = *I;
1816    NamedDecl *InstTarget =
1817      cast_or_null<NamedDecl>(SemaRef.FindInstantiatedDecl(
1818                                                          Shadow->getLocation(),
1819                                                        Shadow->getTargetDecl(),
1820                                                           TemplateArgs));
1821    if (!InstTarget)
1822      return 0;
1823
1824    if (CheckRedeclaration &&
1825        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1826      continue;
1827
1828    UsingShadowDecl *InstShadow
1829      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1830    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1831
1832    if (isFunctionScope)
1833      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1834  }
1835
1836  return NewUD;
1837}
1838
1839Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1840  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1841  return 0;
1842}
1843
1844Decl * TemplateDeclInstantiator
1845    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1846  NestedNameSpecifierLoc QualifierLoc
1847    = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
1848                                          TemplateArgs);
1849  if (!QualifierLoc)
1850    return 0;
1851
1852  CXXScopeSpec SS;
1853  SS.Adopt(QualifierLoc);
1854
1855  // Since NameInfo refers to a typename, it cannot be a C++ special name.
1856  // Hence, no tranformation is required for it.
1857  DeclarationNameInfo NameInfo(D->getDeclName(), D->getLocation());
1858  NamedDecl *UD =
1859    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1860                                  D->getUsingLoc(), SS, NameInfo, 0,
1861                                  /*instantiation*/ true,
1862                                  /*typename*/ true, D->getTypenameLoc());
1863  if (UD)
1864    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1865
1866  return UD;
1867}
1868
1869Decl * TemplateDeclInstantiator
1870    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1871  NestedNameSpecifierLoc QualifierLoc
1872      = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(), TemplateArgs);
1873  if (!QualifierLoc)
1874    return 0;
1875
1876  CXXScopeSpec SS;
1877  SS.Adopt(QualifierLoc);
1878
1879  DeclarationNameInfo NameInfo
1880    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1881
1882  NamedDecl *UD =
1883    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1884                                  D->getUsingLoc(), SS, NameInfo, 0,
1885                                  /*instantiation*/ true,
1886                                  /*typename*/ false, SourceLocation());
1887  if (UD)
1888    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1889
1890  return UD;
1891}
1892
1893Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1894                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1895  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1896  if (D->isInvalidDecl())
1897    return 0;
1898
1899  return Instantiator.Visit(D);
1900}
1901
1902/// \brief Instantiates a nested template parameter list in the current
1903/// instantiation context.
1904///
1905/// \param L The parameter list to instantiate
1906///
1907/// \returns NULL if there was an error
1908TemplateParameterList *
1909TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1910  // Get errors for all the parameters before bailing out.
1911  bool Invalid = false;
1912
1913  unsigned N = L->size();
1914  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1915  ParamVector Params;
1916  Params.reserve(N);
1917  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1918       PI != PE; ++PI) {
1919    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1920    Params.push_back(D);
1921    Invalid = Invalid || !D || D->isInvalidDecl();
1922  }
1923
1924  // Clean up if we had an error.
1925  if (Invalid)
1926    return NULL;
1927
1928  TemplateParameterList *InstL
1929    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1930                                    L->getLAngleLoc(), &Params.front(), N,
1931                                    L->getRAngleLoc());
1932  return InstL;
1933}
1934
1935/// \brief Instantiate the declaration of a class template partial
1936/// specialization.
1937///
1938/// \param ClassTemplate the (instantiated) class template that is partially
1939// specialized by the instantiation of \p PartialSpec.
1940///
1941/// \param PartialSpec the (uninstantiated) class template partial
1942/// specialization that we are instantiating.
1943///
1944/// \returns The instantiated partial specialization, if successful; otherwise,
1945/// NULL to indicate an error.
1946ClassTemplatePartialSpecializationDecl *
1947TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1948                                            ClassTemplateDecl *ClassTemplate,
1949                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1950  // Create a local instantiation scope for this class template partial
1951  // specialization, which will contain the instantiations of the template
1952  // parameters.
1953  LocalInstantiationScope Scope(SemaRef);
1954
1955  // Substitute into the template parameters of the class template partial
1956  // specialization.
1957  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1958  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1959  if (!InstParams)
1960    return 0;
1961
1962  // Substitute into the template arguments of the class template partial
1963  // specialization.
1964  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1965  if (SemaRef.Subst(PartialSpec->getTemplateArgsAsWritten(),
1966                    PartialSpec->getNumTemplateArgsAsWritten(),
1967                    InstTemplateArgs, TemplateArgs))
1968    return 0;
1969
1970  // Check that the template argument list is well-formed for this
1971  // class template.
1972  llvm::SmallVector<TemplateArgument, 4> Converted;
1973  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1974                                        PartialSpec->getLocation(),
1975                                        InstTemplateArgs,
1976                                        false,
1977                                        Converted))
1978    return 0;
1979
1980  // Figure out where to insert this class template partial specialization
1981  // in the member template's set of class template partial specializations.
1982  void *InsertPos = 0;
1983  ClassTemplateSpecializationDecl *PrevDecl
1984    = ClassTemplate->findPartialSpecialization(Converted.data(),
1985                                               Converted.size(), InsertPos);
1986
1987  // Build the canonical type that describes the converted template
1988  // arguments of the class template partial specialization.
1989  QualType CanonType
1990    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1991                                                    Converted.data(),
1992                                                    Converted.size());
1993
1994  // Build the fully-sugared type for this class template
1995  // specialization as the user wrote in the specialization
1996  // itself. This means that we'll pretty-print the type retrieved
1997  // from the specialization's declaration the way that the user
1998  // actually wrote the specialization, rather than formatting the
1999  // name based on the "canonical" representation used to store the
2000  // template arguments in the specialization.
2001  TypeSourceInfo *WrittenTy
2002    = SemaRef.Context.getTemplateSpecializationTypeInfo(
2003                                                    TemplateName(ClassTemplate),
2004                                                    PartialSpec->getLocation(),
2005                                                    InstTemplateArgs,
2006                                                    CanonType);
2007
2008  if (PrevDecl) {
2009    // We've already seen a partial specialization with the same template
2010    // parameters and template arguments. This can happen, for example, when
2011    // substituting the outer template arguments ends up causing two
2012    // class template partial specializations of a member class template
2013    // to have identical forms, e.g.,
2014    //
2015    //   template<typename T, typename U>
2016    //   struct Outer {
2017    //     template<typename X, typename Y> struct Inner;
2018    //     template<typename Y> struct Inner<T, Y>;
2019    //     template<typename Y> struct Inner<U, Y>;
2020    //   };
2021    //
2022    //   Outer<int, int> outer; // error: the partial specializations of Inner
2023    //                          // have the same signature.
2024    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
2025      << WrittenTy->getType();
2026    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
2027      << SemaRef.Context.getTypeDeclType(PrevDecl);
2028    return 0;
2029  }
2030
2031
2032  // Create the class template partial specialization declaration.
2033  ClassTemplatePartialSpecializationDecl *InstPartialSpec
2034    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
2035                                                     PartialSpec->getTagKind(),
2036                                                     Owner,
2037                                                     PartialSpec->getLocStart(),
2038                                                     PartialSpec->getLocation(),
2039                                                     InstParams,
2040                                                     ClassTemplate,
2041                                                     Converted.data(),
2042                                                     Converted.size(),
2043                                                     InstTemplateArgs,
2044                                                     CanonType,
2045                                                     0,
2046                             ClassTemplate->getNextPartialSpecSequenceNumber());
2047  // Substitute the nested name specifier, if any.
2048  if (SubstQualifier(PartialSpec, InstPartialSpec))
2049    return 0;
2050
2051  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
2052  InstPartialSpec->setTypeAsWritten(WrittenTy);
2053
2054  // Add this partial specialization to the set of class template partial
2055  // specializations.
2056  ClassTemplate->AddPartialSpecialization(InstPartialSpec, InsertPos);
2057  return InstPartialSpec;
2058}
2059
2060TypeSourceInfo*
2061TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
2062                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
2063  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
2064  assert(OldTInfo && "substituting function without type source info");
2065  assert(Params.empty() && "parameter vector is non-empty at start");
2066  TypeSourceInfo *NewTInfo
2067    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
2068                                    D->getTypeSpecStartLoc(),
2069                                    D->getDeclName());
2070  if (!NewTInfo)
2071    return 0;
2072
2073  if (NewTInfo != OldTInfo) {
2074    // Get parameters from the new type info.
2075    TypeLoc OldTL = OldTInfo->getTypeLoc().IgnoreParens();
2076    if (FunctionProtoTypeLoc *OldProtoLoc
2077                                  = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
2078      TypeLoc NewTL = NewTInfo->getTypeLoc().IgnoreParens();
2079      FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
2080      assert(NewProtoLoc && "Missing prototype?");
2081      unsigned NewIdx = 0, NumNewParams = NewProtoLoc->getNumArgs();
2082      for (unsigned OldIdx = 0, NumOldParams = OldProtoLoc->getNumArgs();
2083           OldIdx != NumOldParams; ++OldIdx) {
2084        ParmVarDecl *OldParam = OldProtoLoc->getArg(OldIdx);
2085        if (!OldParam->isParameterPack() ||
2086            (NewIdx < NumNewParams &&
2087             NewProtoLoc->getArg(NewIdx)->isParameterPack())) {
2088          // Simple case: normal parameter, or a parameter pack that's
2089          // instantiated to a (still-dependent) parameter pack.
2090          ParmVarDecl *NewParam = NewProtoLoc->getArg(NewIdx++);
2091          Params.push_back(NewParam);
2092          SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldParam,
2093                                                               NewParam);
2094          continue;
2095        }
2096
2097        // Parameter pack: make the instantiation an argument pack.
2098        SemaRef.CurrentInstantiationScope->MakeInstantiatedLocalArgPack(
2099                                                                      OldParam);
2100        unsigned NumArgumentsInExpansion
2101          = SemaRef.getNumArgumentsInExpansion(OldParam->getType(),
2102                                               TemplateArgs);
2103        while (NumArgumentsInExpansion--) {
2104          ParmVarDecl *NewParam = NewProtoLoc->getArg(NewIdx++);
2105          Params.push_back(NewParam);
2106          SemaRef.CurrentInstantiationScope->InstantiatedLocalPackArg(OldParam,
2107                                                                      NewParam);
2108        }
2109      }
2110    }
2111  } else {
2112    // The function type itself was not dependent and therefore no
2113    // substitution occurred. However, we still need to instantiate
2114    // the function parameters themselves.
2115    TypeLoc OldTL = OldTInfo->getTypeLoc().IgnoreParens();
2116    if (FunctionProtoTypeLoc *OldProtoLoc
2117                                    = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
2118      for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
2119        ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
2120        if (!Parm)
2121          return 0;
2122        Params.push_back(Parm);
2123      }
2124    }
2125  }
2126  return NewTInfo;
2127}
2128
2129/// \brief Initializes the common fields of an instantiation function
2130/// declaration (New) from the corresponding fields of its template (Tmpl).
2131///
2132/// \returns true if there was an error
2133bool
2134TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
2135                                                    FunctionDecl *Tmpl) {
2136  if (Tmpl->isDeletedAsWritten())
2137    New->setDeletedAsWritten();
2138
2139  // If we are performing substituting explicitly-specified template arguments
2140  // or deduced template arguments into a function template and we reach this
2141  // point, we are now past the point where SFINAE applies and have committed
2142  // to keeping the new function template specialization. We therefore
2143  // convert the active template instantiation for the function template
2144  // into a template instantiation for this specific function template
2145  // specialization, which is not a SFINAE context, so that we diagnose any
2146  // further errors in the declaration itself.
2147  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
2148  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
2149  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
2150      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
2151    if (FunctionTemplateDecl *FunTmpl
2152          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
2153      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
2154             "Deduction from the wrong function template?");
2155      (void) FunTmpl;
2156      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
2157      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
2158      --SemaRef.NonInstantiationEntries;
2159    }
2160  }
2161
2162  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
2163  assert(Proto && "Function template without prototype?");
2164
2165  if (Proto->hasExceptionSpec() || Proto->getNoReturnAttr()) {
2166    // The function has an exception specification or a "noreturn"
2167    // attribute. Substitute into each of the exception types.
2168    llvm::SmallVector<QualType, 4> Exceptions;
2169    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
2170      // FIXME: Poor location information!
2171      if (const PackExpansionType *PackExpansion
2172            = Proto->getExceptionType(I)->getAs<PackExpansionType>()) {
2173        // We have a pack expansion. Instantiate it.
2174        llvm::SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2175        SemaRef.collectUnexpandedParameterPacks(PackExpansion->getPattern(),
2176                                                Unexpanded);
2177        assert(!Unexpanded.empty() &&
2178               "Pack expansion without parameter packs?");
2179
2180        bool Expand = false;
2181        bool RetainExpansion = false;
2182        llvm::Optional<unsigned> NumExpansions
2183                                          = PackExpansion->getNumExpansions();
2184        if (SemaRef.CheckParameterPacksForExpansion(New->getLocation(),
2185                                                    SourceRange(),
2186                                                    Unexpanded.data(),
2187                                                    Unexpanded.size(),
2188                                                    TemplateArgs,
2189                                                    Expand,
2190                                                    RetainExpansion,
2191                                                    NumExpansions))
2192          break;
2193
2194        if (!Expand) {
2195          // We can't expand this pack expansion into separate arguments yet;
2196          // just substitute into the pattern and create a new pack expansion
2197          // type.
2198          Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2199          QualType T = SemaRef.SubstType(PackExpansion->getPattern(),
2200                                         TemplateArgs,
2201                                       New->getLocation(), New->getDeclName());
2202          if (T.isNull())
2203            break;
2204
2205          T = SemaRef.Context.getPackExpansionType(T, NumExpansions);
2206          Exceptions.push_back(T);
2207          continue;
2208        }
2209
2210        // Substitute into the pack expansion pattern for each template
2211        bool Invalid = false;
2212        for (unsigned ArgIdx = 0; ArgIdx != *NumExpansions; ++ArgIdx) {
2213          Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, ArgIdx);
2214
2215          QualType T = SemaRef.SubstType(PackExpansion->getPattern(),
2216                                         TemplateArgs,
2217                                       New->getLocation(), New->getDeclName());
2218          if (T.isNull()) {
2219            Invalid = true;
2220            break;
2221          }
2222
2223          Exceptions.push_back(T);
2224        }
2225
2226        if (Invalid)
2227          break;
2228
2229        continue;
2230      }
2231
2232      QualType T
2233        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
2234                            New->getLocation(), New->getDeclName());
2235      if (T.isNull() ||
2236          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
2237        continue;
2238
2239      Exceptions.push_back(T);
2240    }
2241    Expr *NoexceptExpr = 0;
2242    if (Expr *OldNoexceptExpr = Proto->getNoexceptExpr()) {
2243      EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
2244      ExprResult E = SemaRef.SubstExpr(OldNoexceptExpr, TemplateArgs);
2245      if (E.isUsable())
2246        NoexceptExpr = E.take();
2247    }
2248
2249    // Rebuild the function type
2250
2251    FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
2252    EPI.ExceptionSpecType = Proto->getExceptionSpecType();
2253    EPI.NumExceptions = Exceptions.size();
2254    EPI.Exceptions = Exceptions.data();
2255    EPI.NoexceptExpr = NoexceptExpr;
2256    EPI.ExtInfo = Proto->getExtInfo();
2257
2258    const FunctionProtoType *NewProto
2259      = New->getType()->getAs<FunctionProtoType>();
2260    assert(NewProto && "Template instantiation without function prototype?");
2261    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
2262                                                 NewProto->arg_type_begin(),
2263                                                 NewProto->getNumArgs(),
2264                                                 EPI));
2265  }
2266
2267  SemaRef.InstantiateAttrs(TemplateArgs, Tmpl, New);
2268
2269  return false;
2270}
2271
2272/// \brief Initializes common fields of an instantiated method
2273/// declaration (New) from the corresponding fields of its template
2274/// (Tmpl).
2275///
2276/// \returns true if there was an error
2277bool
2278TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
2279                                                  CXXMethodDecl *Tmpl) {
2280  if (InitFunctionInstantiation(New, Tmpl))
2281    return true;
2282
2283  New->setAccess(Tmpl->getAccess());
2284  if (Tmpl->isVirtualAsWritten())
2285    New->setVirtualAsWritten(true);
2286
2287  // FIXME: attributes
2288  // FIXME: New needs a pointer to Tmpl
2289  return false;
2290}
2291
2292/// \brief Instantiate the definition of the given function from its
2293/// template.
2294///
2295/// \param PointOfInstantiation the point at which the instantiation was
2296/// required. Note that this is not precisely a "point of instantiation"
2297/// for the function, but it's close.
2298///
2299/// \param Function the already-instantiated declaration of a
2300/// function template specialization or member function of a class template
2301/// specialization.
2302///
2303/// \param Recursive if true, recursively instantiates any functions that
2304/// are required by this instantiation.
2305///
2306/// \param DefinitionRequired if true, then we are performing an explicit
2307/// instantiation where the body of the function is required. Complain if
2308/// there is no such body.
2309void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
2310                                         FunctionDecl *Function,
2311                                         bool Recursive,
2312                                         bool DefinitionRequired) {
2313  if (Function->isInvalidDecl() || Function->isDefined())
2314    return;
2315
2316  // Never instantiate an explicit specialization.
2317  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2318    return;
2319
2320  // Find the function body that we'll be substituting.
2321  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
2322  assert(PatternDecl && "instantiating a non-template");
2323
2324  Stmt *Pattern = PatternDecl->getBody(PatternDecl);
2325  assert(PatternDecl && "template definition is not a template");
2326  if (!Pattern) {
2327    // Try to find a defaulted definition
2328    PatternDecl->isDefined(PatternDecl);
2329  }
2330  assert(PatternDecl && "template definition is not a template");
2331
2332  // Postpone late parsed template instantiations.
2333  if (PatternDecl->isLateTemplateParsed() &&
2334      !LateTemplateParser) {
2335    PendingInstantiations.push_back(
2336      std::make_pair(Function, PointOfInstantiation));
2337    return;
2338  }
2339
2340  // Call the LateTemplateParser callback if there a need to late parse
2341  // a templated function definition.
2342  if (!Pattern && PatternDecl->isLateTemplateParsed() &&
2343      LateTemplateParser) {
2344    LateTemplateParser(OpaqueParser, PatternDecl);
2345    Pattern = PatternDecl->getBody(PatternDecl);
2346  }
2347
2348  if (!Pattern && !PatternDecl->isDefaulted()) {
2349    if (DefinitionRequired) {
2350      if (Function->getPrimaryTemplate())
2351        Diag(PointOfInstantiation,
2352             diag::err_explicit_instantiation_undefined_func_template)
2353          << Function->getPrimaryTemplate();
2354      else
2355        Diag(PointOfInstantiation,
2356             diag::err_explicit_instantiation_undefined_member)
2357          << 1 << Function->getDeclName() << Function->getDeclContext();
2358
2359      if (PatternDecl)
2360        Diag(PatternDecl->getLocation(),
2361             diag::note_explicit_instantiation_here);
2362      Function->setInvalidDecl();
2363    } else if (Function->getTemplateSpecializationKind()
2364                 == TSK_ExplicitInstantiationDefinition) {
2365      PendingInstantiations.push_back(
2366        std::make_pair(Function, PointOfInstantiation));
2367    }
2368
2369    return;
2370  }
2371
2372  // C++0x [temp.explicit]p9:
2373  //   Except for inline functions, other explicit instantiation declarations
2374  //   have the effect of suppressing the implicit instantiation of the entity
2375  //   to which they refer.
2376  if (Function->getTemplateSpecializationKind()
2377        == TSK_ExplicitInstantiationDeclaration &&
2378      !PatternDecl->isInlined())
2379    return;
2380
2381  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2382  if (Inst)
2383    return;
2384
2385  // If we're performing recursive template instantiation, create our own
2386  // queue of pending implicit instantiations that we will instantiate later,
2387  // while we're still within our own instantiation context.
2388  llvm::SmallVector<VTableUse, 16> SavedVTableUses;
2389  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2390  if (Recursive) {
2391    VTableUses.swap(SavedVTableUses);
2392    PendingInstantiations.swap(SavedPendingInstantiations);
2393  }
2394
2395  EnterExpressionEvaluationContext EvalContext(*this,
2396                                               Sema::PotentiallyEvaluated);
2397  ActOnStartOfFunctionDef(0, Function);
2398
2399  // Introduce a new scope where local variable instantiations will be
2400  // recorded, unless we're actually a member function within a local
2401  // class, in which case we need to merge our results with the parent
2402  // scope (of the enclosing function).
2403  bool MergeWithParentScope = false;
2404  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2405    MergeWithParentScope = Rec->isLocalClass();
2406
2407  LocalInstantiationScope Scope(*this, MergeWithParentScope);
2408
2409  // Introduce the instantiated function parameters into the local
2410  // instantiation scope, and set the parameter names to those used
2411  // in the template.
2412  unsigned FParamIdx = 0;
2413  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
2414    const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
2415    if (!PatternParam->isParameterPack()) {
2416      // Simple case: not a parameter pack.
2417      assert(FParamIdx < Function->getNumParams());
2418      ParmVarDecl *FunctionParam = Function->getParamDecl(I);
2419      FunctionParam->setDeclName(PatternParam->getDeclName());
2420      Scope.InstantiatedLocal(PatternParam, FunctionParam);
2421      ++FParamIdx;
2422      continue;
2423    }
2424
2425    // Expand the parameter pack.
2426    Scope.MakeInstantiatedLocalArgPack(PatternParam);
2427    for (unsigned NumFParams = Function->getNumParams();
2428         FParamIdx < NumFParams;
2429         ++FParamIdx) {
2430      ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
2431      FunctionParam->setDeclName(PatternParam->getDeclName());
2432      Scope.InstantiatedLocalPackArg(PatternParam, FunctionParam);
2433    }
2434  }
2435
2436  // Enter the scope of this instantiation. We don't use
2437  // PushDeclContext because we don't have a scope.
2438  Sema::ContextRAII savedContext(*this, Function);
2439
2440  MultiLevelTemplateArgumentList TemplateArgs =
2441    getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
2442
2443  if (PatternDecl->isDefaulted()) {
2444    ActOnFinishFunctionBody(Function, 0, /*IsInstantiation=*/true);
2445
2446    SetDeclDefaulted(Function, PatternDecl->getLocation());
2447  } else {
2448    // If this is a constructor, instantiate the member initializers.
2449    if (const CXXConstructorDecl *Ctor =
2450          dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2451      InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2452                                 TemplateArgs);
2453    }
2454
2455    // Instantiate the function body.
2456    StmtResult Body = SubstStmt(Pattern, TemplateArgs);
2457
2458    if (Body.isInvalid())
2459      Function->setInvalidDecl();
2460
2461    ActOnFinishFunctionBody(Function, Body.get(),
2462                            /*IsInstantiation=*/true);
2463  }
2464
2465  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2466
2467  savedContext.pop();
2468
2469  DeclGroupRef DG(Function);
2470  Consumer.HandleTopLevelDecl(DG);
2471
2472  // This class may have local implicit instantiations that need to be
2473  // instantiation within this scope.
2474  PerformPendingInstantiations(/*LocalOnly=*/true);
2475  Scope.Exit();
2476
2477  if (Recursive) {
2478    // Define any pending vtables.
2479    DefineUsedVTables();
2480
2481    // Instantiate any pending implicit instantiations found during the
2482    // instantiation of this template.
2483    PerformPendingInstantiations();
2484
2485    // Restore the set of pending vtables.
2486    assert(VTableUses.empty() &&
2487           "VTableUses should be empty before it is discarded.");
2488    VTableUses.swap(SavedVTableUses);
2489
2490    // Restore the set of pending implicit instantiations.
2491    assert(PendingInstantiations.empty() &&
2492           "PendingInstantiations should be empty before it is discarded.");
2493    PendingInstantiations.swap(SavedPendingInstantiations);
2494  }
2495}
2496
2497/// \brief Instantiate the definition of the given variable from its
2498/// template.
2499///
2500/// \param PointOfInstantiation the point at which the instantiation was
2501/// required. Note that this is not precisely a "point of instantiation"
2502/// for the function, but it's close.
2503///
2504/// \param Var the already-instantiated declaration of a static member
2505/// variable of a class template specialization.
2506///
2507/// \param Recursive if true, recursively instantiates any functions that
2508/// are required by this instantiation.
2509///
2510/// \param DefinitionRequired if true, then we are performing an explicit
2511/// instantiation where an out-of-line definition of the member variable
2512/// is required. Complain if there is no such definition.
2513void Sema::InstantiateStaticDataMemberDefinition(
2514                                          SourceLocation PointOfInstantiation,
2515                                                 VarDecl *Var,
2516                                                 bool Recursive,
2517                                                 bool DefinitionRequired) {
2518  if (Var->isInvalidDecl())
2519    return;
2520
2521  // Find the out-of-line definition of this static data member.
2522  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2523  assert(Def && "This data member was not instantiated from a template?");
2524  assert(Def->isStaticDataMember() && "Not a static data member?");
2525  Def = Def->getOutOfLineDefinition();
2526
2527  if (!Def) {
2528    // We did not find an out-of-line definition of this static data member,
2529    // so we won't perform any instantiation. Rather, we rely on the user to
2530    // instantiate this definition (or provide a specialization for it) in
2531    // another translation unit.
2532    if (DefinitionRequired) {
2533      Def = Var->getInstantiatedFromStaticDataMember();
2534      Diag(PointOfInstantiation,
2535           diag::err_explicit_instantiation_undefined_member)
2536        << 2 << Var->getDeclName() << Var->getDeclContext();
2537      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2538    } else if (Var->getTemplateSpecializationKind()
2539                 == TSK_ExplicitInstantiationDefinition) {
2540      PendingInstantiations.push_back(
2541        std::make_pair(Var, PointOfInstantiation));
2542    }
2543
2544    return;
2545  }
2546
2547  // Never instantiate an explicit specialization.
2548  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2549    return;
2550
2551  // C++0x [temp.explicit]p9:
2552  //   Except for inline functions, other explicit instantiation declarations
2553  //   have the effect of suppressing the implicit instantiation of the entity
2554  //   to which they refer.
2555  if (Var->getTemplateSpecializationKind()
2556        == TSK_ExplicitInstantiationDeclaration)
2557    return;
2558
2559  // If we already have a definition, we're done.
2560  if (Var->getDefinition())
2561    return;
2562
2563  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2564  if (Inst)
2565    return;
2566
2567  // If we're performing recursive template instantiation, create our own
2568  // queue of pending implicit instantiations that we will instantiate later,
2569  // while we're still within our own instantiation context.
2570  llvm::SmallVector<VTableUse, 16> SavedVTableUses;
2571  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2572  if (Recursive) {
2573    VTableUses.swap(SavedVTableUses);
2574    PendingInstantiations.swap(SavedPendingInstantiations);
2575  }
2576
2577  // Enter the scope of this instantiation. We don't use
2578  // PushDeclContext because we don't have a scope.
2579  ContextRAII previousContext(*this, Var->getDeclContext());
2580
2581  VarDecl *OldVar = Var;
2582  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2583                                        getTemplateInstantiationArgs(Var)));
2584
2585  previousContext.pop();
2586
2587  if (Var) {
2588    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2589    assert(MSInfo && "Missing member specialization information?");
2590    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2591                                       MSInfo->getPointOfInstantiation());
2592    DeclGroupRef DG(Var);
2593    Consumer.HandleTopLevelDecl(DG);
2594  }
2595
2596  if (Recursive) {
2597    // Define any newly required vtables.
2598    DefineUsedVTables();
2599
2600    // Instantiate any pending implicit instantiations found during the
2601    // instantiation of this template.
2602    PerformPendingInstantiations();
2603
2604    // Restore the set of pending vtables.
2605    assert(VTableUses.empty() &&
2606           "VTableUses should be empty before it is discarded, "
2607           "while instantiating static data member.");
2608    VTableUses.swap(SavedVTableUses);
2609
2610    // Restore the set of pending implicit instantiations.
2611    assert(PendingInstantiations.empty() &&
2612           "PendingInstantiations should be empty before it is discarded, "
2613           "while instantiating static data member.");
2614    PendingInstantiations.swap(SavedPendingInstantiations);
2615  }
2616}
2617
2618void
2619Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2620                                 const CXXConstructorDecl *Tmpl,
2621                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2622
2623  llvm::SmallVector<MemInitTy*, 4> NewInits;
2624  bool AnyErrors = false;
2625
2626  // Instantiate all the initializers.
2627  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2628                                            InitsEnd = Tmpl->init_end();
2629       Inits != InitsEnd; ++Inits) {
2630    CXXCtorInitializer *Init = *Inits;
2631
2632    // Only instantiate written initializers, let Sema re-construct implicit
2633    // ones.
2634    if (!Init->isWritten())
2635      continue;
2636
2637    SourceLocation LParenLoc, RParenLoc;
2638    ASTOwningVector<Expr*> NewArgs(*this);
2639
2640    SourceLocation EllipsisLoc;
2641
2642    if (Init->isPackExpansion()) {
2643      // This is a pack expansion. We should expand it now.
2644      TypeLoc BaseTL = Init->getBaseClassInfo()->getTypeLoc();
2645      llvm::SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2646      collectUnexpandedParameterPacks(BaseTL, Unexpanded);
2647      bool ShouldExpand = false;
2648      bool RetainExpansion = false;
2649      llvm::Optional<unsigned> NumExpansions;
2650      if (CheckParameterPacksForExpansion(Init->getEllipsisLoc(),
2651                                          BaseTL.getSourceRange(),
2652                                          Unexpanded.data(),
2653                                          Unexpanded.size(),
2654                                          TemplateArgs, ShouldExpand,
2655                                          RetainExpansion,
2656                                          NumExpansions)) {
2657        AnyErrors = true;
2658        New->setInvalidDecl();
2659        continue;
2660      }
2661      assert(ShouldExpand && "Partial instantiation of base initializer?");
2662
2663      // Loop over all of the arguments in the argument pack(s),
2664      for (unsigned I = 0; I != *NumExpansions; ++I) {
2665        Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, I);
2666
2667        // Instantiate the initializer.
2668        if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2669                                   LParenLoc, NewArgs, RParenLoc)) {
2670          AnyErrors = true;
2671          break;
2672        }
2673
2674        // Instantiate the base type.
2675        TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2676                                              TemplateArgs,
2677                                              Init->getSourceLocation(),
2678                                              New->getDeclName());
2679        if (!BaseTInfo) {
2680          AnyErrors = true;
2681          break;
2682        }
2683
2684        // Build the initializer.
2685        MemInitResult NewInit = BuildBaseInitializer(BaseTInfo->getType(),
2686                                                     BaseTInfo,
2687                                                     (Expr **)NewArgs.data(),
2688                                                     NewArgs.size(),
2689                                                     Init->getLParenLoc(),
2690                                                     Init->getRParenLoc(),
2691                                                     New->getParent(),
2692                                                     SourceLocation());
2693        if (NewInit.isInvalid()) {
2694          AnyErrors = true;
2695          break;
2696        }
2697
2698        NewInits.push_back(NewInit.get());
2699        NewArgs.clear();
2700      }
2701
2702      continue;
2703    }
2704
2705    // Instantiate the initializer.
2706    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2707                               LParenLoc, NewArgs, RParenLoc)) {
2708      AnyErrors = true;
2709      continue;
2710    }
2711
2712    MemInitResult NewInit;
2713    if (Init->isBaseInitializer()) {
2714      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2715                                            TemplateArgs,
2716                                            Init->getSourceLocation(),
2717                                            New->getDeclName());
2718      if (!BaseTInfo) {
2719        AnyErrors = true;
2720        New->setInvalidDecl();
2721        continue;
2722      }
2723
2724      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2725                                     (Expr **)NewArgs.data(),
2726                                     NewArgs.size(),
2727                                     Init->getLParenLoc(),
2728                                     Init->getRParenLoc(),
2729                                     New->getParent(),
2730                                     EllipsisLoc);
2731    } else if (Init->isMemberInitializer()) {
2732      FieldDecl *Member = cast_or_null<FieldDecl>(FindInstantiatedDecl(
2733                                                     Init->getMemberLocation(),
2734                                                     Init->getMember(),
2735                                                     TemplateArgs));
2736      if (!Member) {
2737        AnyErrors = true;
2738        New->setInvalidDecl();
2739        continue;
2740      }
2741
2742      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2743                                       NewArgs.size(),
2744                                       Init->getSourceLocation(),
2745                                       Init->getLParenLoc(),
2746                                       Init->getRParenLoc());
2747    } else if (Init->isIndirectMemberInitializer()) {
2748      IndirectFieldDecl *IndirectMember =
2749         cast_or_null<IndirectFieldDecl>(FindInstantiatedDecl(
2750                                 Init->getMemberLocation(),
2751                                 Init->getIndirectMember(), TemplateArgs));
2752
2753      if (!IndirectMember) {
2754        AnyErrors = true;
2755        New->setInvalidDecl();
2756        continue;
2757      }
2758
2759      NewInit = BuildMemberInitializer(IndirectMember, (Expr **)NewArgs.data(),
2760                                       NewArgs.size(),
2761                                       Init->getSourceLocation(),
2762                                       Init->getLParenLoc(),
2763                                       Init->getRParenLoc());
2764    }
2765
2766    if (NewInit.isInvalid()) {
2767      AnyErrors = true;
2768      New->setInvalidDecl();
2769    } else {
2770      // FIXME: It would be nice if ASTOwningVector had a release function.
2771      NewArgs.take();
2772
2773      NewInits.push_back((MemInitTy *)NewInit.get());
2774    }
2775  }
2776
2777  // Assign all the initializers to the new constructor.
2778  ActOnMemInitializers(New,
2779                       /*FIXME: ColonLoc */
2780                       SourceLocation(),
2781                       NewInits.data(), NewInits.size(),
2782                       AnyErrors);
2783}
2784
2785// TODO: this could be templated if the various decl types used the
2786// same method name.
2787static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2788                              ClassTemplateDecl *Instance) {
2789  Pattern = Pattern->getCanonicalDecl();
2790
2791  do {
2792    Instance = Instance->getCanonicalDecl();
2793    if (Pattern == Instance) return true;
2794    Instance = Instance->getInstantiatedFromMemberTemplate();
2795  } while (Instance);
2796
2797  return false;
2798}
2799
2800static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2801                              FunctionTemplateDecl *Instance) {
2802  Pattern = Pattern->getCanonicalDecl();
2803
2804  do {
2805    Instance = Instance->getCanonicalDecl();
2806    if (Pattern == Instance) return true;
2807    Instance = Instance->getInstantiatedFromMemberTemplate();
2808  } while (Instance);
2809
2810  return false;
2811}
2812
2813static bool
2814isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2815                  ClassTemplatePartialSpecializationDecl *Instance) {
2816  Pattern
2817    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2818  do {
2819    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2820                                                Instance->getCanonicalDecl());
2821    if (Pattern == Instance)
2822      return true;
2823    Instance = Instance->getInstantiatedFromMember();
2824  } while (Instance);
2825
2826  return false;
2827}
2828
2829static bool isInstantiationOf(CXXRecordDecl *Pattern,
2830                              CXXRecordDecl *Instance) {
2831  Pattern = Pattern->getCanonicalDecl();
2832
2833  do {
2834    Instance = Instance->getCanonicalDecl();
2835    if (Pattern == Instance) return true;
2836    Instance = Instance->getInstantiatedFromMemberClass();
2837  } while (Instance);
2838
2839  return false;
2840}
2841
2842static bool isInstantiationOf(FunctionDecl *Pattern,
2843                              FunctionDecl *Instance) {
2844  Pattern = Pattern->getCanonicalDecl();
2845
2846  do {
2847    Instance = Instance->getCanonicalDecl();
2848    if (Pattern == Instance) return true;
2849    Instance = Instance->getInstantiatedFromMemberFunction();
2850  } while (Instance);
2851
2852  return false;
2853}
2854
2855static bool isInstantiationOf(EnumDecl *Pattern,
2856                              EnumDecl *Instance) {
2857  Pattern = Pattern->getCanonicalDecl();
2858
2859  do {
2860    Instance = Instance->getCanonicalDecl();
2861    if (Pattern == Instance) return true;
2862    Instance = Instance->getInstantiatedFromMemberEnum();
2863  } while (Instance);
2864
2865  return false;
2866}
2867
2868static bool isInstantiationOf(UsingShadowDecl *Pattern,
2869                              UsingShadowDecl *Instance,
2870                              ASTContext &C) {
2871  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2872}
2873
2874static bool isInstantiationOf(UsingDecl *Pattern,
2875                              UsingDecl *Instance,
2876                              ASTContext &C) {
2877  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2878}
2879
2880static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2881                              UsingDecl *Instance,
2882                              ASTContext &C) {
2883  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2884}
2885
2886static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2887                              UsingDecl *Instance,
2888                              ASTContext &C) {
2889  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2890}
2891
2892static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2893                                              VarDecl *Instance) {
2894  assert(Instance->isStaticDataMember());
2895
2896  Pattern = Pattern->getCanonicalDecl();
2897
2898  do {
2899    Instance = Instance->getCanonicalDecl();
2900    if (Pattern == Instance) return true;
2901    Instance = Instance->getInstantiatedFromStaticDataMember();
2902  } while (Instance);
2903
2904  return false;
2905}
2906
2907// Other is the prospective instantiation
2908// D is the prospective pattern
2909static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2910  if (D->getKind() != Other->getKind()) {
2911    if (UnresolvedUsingTypenameDecl *UUD
2912          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2913      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2914        return isInstantiationOf(UUD, UD, Ctx);
2915      }
2916    }
2917
2918    if (UnresolvedUsingValueDecl *UUD
2919          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2920      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2921        return isInstantiationOf(UUD, UD, Ctx);
2922      }
2923    }
2924
2925    return false;
2926  }
2927
2928  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2929    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2930
2931  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2932    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2933
2934  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2935    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2936
2937  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2938    if (Var->isStaticDataMember())
2939      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2940
2941  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2942    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2943
2944  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2945    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2946
2947  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2948        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2949    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2950                             PartialSpec);
2951
2952  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2953    if (!Field->getDeclName()) {
2954      // This is an unnamed field.
2955      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2956        cast<FieldDecl>(D);
2957    }
2958  }
2959
2960  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2961    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2962
2963  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2964    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2965
2966  return D->getDeclName() && isa<NamedDecl>(Other) &&
2967    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2968}
2969
2970template<typename ForwardIterator>
2971static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2972                                      NamedDecl *D,
2973                                      ForwardIterator first,
2974                                      ForwardIterator last) {
2975  for (; first != last; ++first)
2976    if (isInstantiationOf(Ctx, D, *first))
2977      return cast<NamedDecl>(*first);
2978
2979  return 0;
2980}
2981
2982/// \brief Finds the instantiation of the given declaration context
2983/// within the current instantiation.
2984///
2985/// \returns NULL if there was an error
2986DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2987                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2988  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2989    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2990    return cast_or_null<DeclContext>(ID);
2991  } else return DC;
2992}
2993
2994/// \brief Find the instantiation of the given declaration within the
2995/// current instantiation.
2996///
2997/// This routine is intended to be used when \p D is a declaration
2998/// referenced from within a template, that needs to mapped into the
2999/// corresponding declaration within an instantiation. For example,
3000/// given:
3001///
3002/// \code
3003/// template<typename T>
3004/// struct X {
3005///   enum Kind {
3006///     KnownValue = sizeof(T)
3007///   };
3008///
3009///   bool getKind() const { return KnownValue; }
3010/// };
3011///
3012/// template struct X<int>;
3013/// \endcode
3014///
3015/// In the instantiation of X<int>::getKind(), we need to map the
3016/// EnumConstantDecl for KnownValue (which refers to
3017/// X<T>::<Kind>::KnownValue) to its instantiation
3018/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
3019/// this mapping from within the instantiation of X<int>.
3020NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
3021                          const MultiLevelTemplateArgumentList &TemplateArgs) {
3022  DeclContext *ParentDC = D->getDeclContext();
3023  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
3024      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
3025      (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext())) {
3026    // D is a local of some kind. Look into the map of local
3027    // declarations to their instantiations.
3028    typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
3029    llvm::PointerUnion<Decl *, DeclArgumentPack *> *Found
3030      = CurrentInstantiationScope->findInstantiationOf(D);
3031
3032    if (Found) {
3033      if (Decl *FD = Found->dyn_cast<Decl *>())
3034        return cast<NamedDecl>(FD);
3035
3036      unsigned PackIdx = ArgumentPackSubstitutionIndex;
3037      return cast<NamedDecl>((*Found->get<DeclArgumentPack *>())[PackIdx]);
3038    }
3039
3040    // If we didn't find the decl, then we must have a label decl that hasn't
3041    // been found yet.  Lazily instantiate it and return it now.
3042    assert(isa<LabelDecl>(D));
3043
3044    Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
3045    assert(Inst && "Failed to instantiate label??");
3046
3047    CurrentInstantiationScope->InstantiatedLocal(D, Inst);
3048    return cast<LabelDecl>(Inst);
3049  }
3050
3051  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
3052    if (!Record->isDependentContext())
3053      return D;
3054
3055    // If the RecordDecl is actually the injected-class-name or a
3056    // "templated" declaration for a class template, class template
3057    // partial specialization, or a member class of a class template,
3058    // substitute into the injected-class-name of the class template
3059    // or partial specialization to find the new DeclContext.
3060    QualType T;
3061    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
3062
3063    if (ClassTemplate) {
3064      T = ClassTemplate->getInjectedClassNameSpecialization();
3065    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
3066                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
3067      ClassTemplate = PartialSpec->getSpecializedTemplate();
3068
3069      // If we call SubstType with an InjectedClassNameType here we
3070      // can end up in an infinite loop.
3071      T = Context.getTypeDeclType(Record);
3072      assert(isa<InjectedClassNameType>(T) &&
3073             "type of partial specialization is not an InjectedClassNameType");
3074      T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
3075    }
3076
3077    if (!T.isNull()) {
3078      // Substitute into the injected-class-name to get the type
3079      // corresponding to the instantiation we want, which may also be
3080      // the current instantiation (if we're in a template
3081      // definition). This substitution should never fail, since we
3082      // know we can instantiate the injected-class-name or we
3083      // wouldn't have gotten to the injected-class-name!
3084
3085      // FIXME: Can we use the CurrentInstantiationScope to avoid this
3086      // extra instantiation in the common case?
3087      T = SubstType(T, TemplateArgs, Loc, DeclarationName());
3088      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
3089
3090      if (!T->isDependentType()) {
3091        assert(T->isRecordType() && "Instantiation must produce a record type");
3092        return T->getAs<RecordType>()->getDecl();
3093      }
3094
3095      // We are performing "partial" template instantiation to create
3096      // the member declarations for the members of a class template
3097      // specialization. Therefore, D is actually referring to something
3098      // in the current instantiation. Look through the current
3099      // context, which contains actual instantiations, to find the
3100      // instantiation of the "current instantiation" that D refers
3101      // to.
3102      bool SawNonDependentContext = false;
3103      for (DeclContext *DC = CurContext; !DC->isFileContext();
3104           DC = DC->getParent()) {
3105        if (ClassTemplateSpecializationDecl *Spec
3106                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
3107          if (isInstantiationOf(ClassTemplate,
3108                                Spec->getSpecializedTemplate()))
3109            return Spec;
3110
3111        if (!DC->isDependentContext())
3112          SawNonDependentContext = true;
3113      }
3114
3115      // We're performing "instantiation" of a member of the current
3116      // instantiation while we are type-checking the
3117      // definition. Compute the declaration context and return that.
3118      assert(!SawNonDependentContext &&
3119             "No dependent context while instantiating record");
3120      DeclContext *DC = computeDeclContext(T);
3121      assert(DC &&
3122             "Unable to find declaration for the current instantiation");
3123      return cast<CXXRecordDecl>(DC);
3124    }
3125
3126    // Fall through to deal with other dependent record types (e.g.,
3127    // anonymous unions in class templates).
3128  }
3129
3130  if (!ParentDC->isDependentContext())
3131    return D;
3132
3133  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
3134  if (!ParentDC)
3135    return 0;
3136
3137  if (ParentDC != D->getDeclContext()) {
3138    // We performed some kind of instantiation in the parent context,
3139    // so now we need to look into the instantiated parent context to
3140    // find the instantiation of the declaration D.
3141
3142    // If our context used to be dependent, we may need to instantiate
3143    // it before performing lookup into that context.
3144    bool IsBeingInstantiated = false;
3145    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
3146      if (!Spec->isDependentContext()) {
3147        QualType T = Context.getTypeDeclType(Spec);
3148        const RecordType *Tag = T->getAs<RecordType>();
3149        assert(Tag && "type of non-dependent record is not a RecordType");
3150        if (Tag->isBeingDefined())
3151          IsBeingInstantiated = true;
3152        if (!Tag->isBeingDefined() &&
3153            RequireCompleteType(Loc, T, diag::err_incomplete_type))
3154          return 0;
3155
3156        ParentDC = Tag->getDecl();
3157      }
3158    }
3159
3160    NamedDecl *Result = 0;
3161    if (D->getDeclName()) {
3162      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
3163      Result = findInstantiationOf(Context, D, Found.first, Found.second);
3164    } else {
3165      // Since we don't have a name for the entity we're looking for,
3166      // our only option is to walk through all of the declarations to
3167      // find that name. This will occur in a few cases:
3168      //
3169      //   - anonymous struct/union within a template
3170      //   - unnamed class/struct/union/enum within a template
3171      //
3172      // FIXME: Find a better way to find these instantiations!
3173      Result = findInstantiationOf(Context, D,
3174                                   ParentDC->decls_begin(),
3175                                   ParentDC->decls_end());
3176    }
3177
3178    if (!Result) {
3179      if (isa<UsingShadowDecl>(D)) {
3180        // UsingShadowDecls can instantiate to nothing because of using hiding.
3181      } else if (Diags.hasErrorOccurred()) {
3182        // We've already complained about something, so most likely this
3183        // declaration failed to instantiate. There's no point in complaining
3184        // further, since this is normal in invalid code.
3185      } else if (IsBeingInstantiated) {
3186        // The class in which this member exists is currently being
3187        // instantiated, and we haven't gotten around to instantiating this
3188        // member yet. This can happen when the code uses forward declarations
3189        // of member classes, and introduces ordering dependencies via
3190        // template instantiation.
3191        Diag(Loc, diag::err_member_not_yet_instantiated)
3192          << D->getDeclName()
3193          << Context.getTypeDeclType(cast<CXXRecordDecl>(ParentDC));
3194        Diag(D->getLocation(), diag::note_non_instantiated_member_here);
3195      } else {
3196        // We should have found something, but didn't.
3197        llvm_unreachable("Unable to find instantiation of declaration!");
3198      }
3199    }
3200
3201    D = Result;
3202  }
3203
3204  return D;
3205}
3206
3207/// \brief Performs template instantiation for all implicit template
3208/// instantiations we have seen until this point.
3209void Sema::PerformPendingInstantiations(bool LocalOnly) {
3210  while (!PendingLocalImplicitInstantiations.empty() ||
3211         (!LocalOnly && !PendingInstantiations.empty())) {
3212    PendingImplicitInstantiation Inst;
3213
3214    if (PendingLocalImplicitInstantiations.empty()) {
3215      Inst = PendingInstantiations.front();
3216      PendingInstantiations.pop_front();
3217    } else {
3218      Inst = PendingLocalImplicitInstantiations.front();
3219      PendingLocalImplicitInstantiations.pop_front();
3220    }
3221
3222    // Instantiate function definitions
3223    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
3224      PrettyDeclStackTraceEntry CrashInfo(*this, Function, SourceLocation(),
3225                                          "instantiating function definition");
3226      bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
3227                                TSK_ExplicitInstantiationDefinition;
3228      InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true,
3229                                    DefinitionRequired);
3230      continue;
3231    }
3232
3233    // Instantiate static data member definitions.
3234    VarDecl *Var = cast<VarDecl>(Inst.first);
3235    assert(Var->isStaticDataMember() && "Not a static data member?");
3236
3237    // Don't try to instantiate declarations if the most recent redeclaration
3238    // is invalid.
3239    if (Var->getMostRecentDeclaration()->isInvalidDecl())
3240      continue;
3241
3242    // Check if the most recent declaration has changed the specialization kind
3243    // and removed the need for implicit instantiation.
3244    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
3245    case TSK_Undeclared:
3246      assert(false && "Cannot instantitiate an undeclared specialization.");
3247    case TSK_ExplicitInstantiationDeclaration:
3248    case TSK_ExplicitSpecialization:
3249      continue;  // No longer need to instantiate this type.
3250    case TSK_ExplicitInstantiationDefinition:
3251      // We only need an instantiation if the pending instantiation *is* the
3252      // explicit instantiation.
3253      if (Var != Var->getMostRecentDeclaration()) continue;
3254    case TSK_ImplicitInstantiation:
3255      break;
3256    }
3257
3258    PrettyDeclStackTraceEntry CrashInfo(*this, Var, Var->getLocation(),
3259                                        "instantiating static data member "
3260                                        "definition");
3261
3262    bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
3263                              TSK_ExplicitInstantiationDefinition;
3264    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true,
3265                                          DefinitionRequired);
3266  }
3267}
3268
3269void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
3270                       const MultiLevelTemplateArgumentList &TemplateArgs) {
3271  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
3272         E = Pattern->ddiag_end(); I != E; ++I) {
3273    DependentDiagnostic *DD = *I;
3274
3275    switch (DD->getKind()) {
3276    case DependentDiagnostic::Access:
3277      HandleDependentAccessCheck(*DD, TemplateArgs);
3278      break;
3279    }
3280  }
3281}
3282