SemaTemplateInstantiateDecl.cpp revision e129d44aab6324aa2094d68730a7843c41a4e45f 
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 "Sema.h"
13#include "Lookup.h"
14#include "clang/AST/ASTConsumer.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/DeclTemplate.h"
17#include "clang/AST/DeclVisitor.h"
18#include "clang/AST/Expr.h"
19#include "clang/AST/ExprCXX.h"
20#include "clang/Basic/PrettyStackTrace.h"
21#include "clang/Lex/Preprocessor.h"
22
23using namespace clang;
24
25namespace {
26  class TemplateDeclInstantiator
27    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
28    Sema &SemaRef;
29    DeclContext *Owner;
30    const MultiLevelTemplateArgumentList &TemplateArgs;
31
32    void InstantiateAttrs(Decl *Tmpl, Decl *New);
33
34  public:
35    typedef Sema::OwningExprResult OwningExprResult;
36
37    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
38                             const MultiLevelTemplateArgumentList &TemplateArgs)
39      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
40
41    // FIXME: Once we get closer to completion, replace these manually-written
42    // declarations with automatically-generated ones from
43    // clang/AST/DeclNodes.def.
44    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
45    Decl *VisitNamespaceDecl(NamespaceDecl *D);
46    Decl *VisitTypedefDecl(TypedefDecl *D);
47    Decl *VisitVarDecl(VarDecl *D);
48    Decl *VisitFieldDecl(FieldDecl *D);
49    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
50    Decl *VisitEnumDecl(EnumDecl *D);
51    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
52    Decl *VisitFriendDecl(FriendDecl *D);
53    Decl *VisitFunctionDecl(FunctionDecl *D,
54                            TemplateParameterList *TemplateParams = 0);
55    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
56    Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
57                             TemplateParameterList *TemplateParams = 0);
58    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
59    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
60    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
61    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
62    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
63    Decl *VisitClassTemplatePartialSpecializationDecl(
64                                    ClassTemplatePartialSpecializationDecl *D);
65    Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
66    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
67    Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
68    Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
69    Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
70    Decl *VisitUsingDecl(UsingDecl *D);
71    Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
72    Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
73    Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
74
75    // Base case. FIXME: Remove once we can instantiate everything.
76    Decl *VisitDecl(Decl *D) {
77      unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
78                                                            Diagnostic::Error,
79                                                   "cannot instantiate %0 yet");
80      SemaRef.Diag(D->getLocation(), DiagID)
81        << D->getDeclKindName();
82
83      return 0;
84    }
85
86    const LangOptions &getLangOptions() {
87      return SemaRef.getLangOptions();
88    }
89
90    // Helper functions for instantiating methods.
91    QualType SubstFunctionType(FunctionDecl *D,
92                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
93    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
94    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
95
96    TemplateParameterList *
97      SubstTemplateParams(TemplateParameterList *List);
98
99    bool InstantiateClassTemplatePartialSpecialization(
100                                              ClassTemplateDecl *ClassTemplate,
101                           ClassTemplatePartialSpecializationDecl *PartialSpec);
102  };
103}
104
105// FIXME: Is this too simple?
106void TemplateDeclInstantiator::InstantiateAttrs(Decl *Tmpl, Decl *New) {
107  for (const Attr *TmplAttr = Tmpl->getAttrs(); TmplAttr;
108       TmplAttr = TmplAttr->getNext()) {
109
110    // FIXME: Is cloning correct for all attributes?
111    Attr *NewAttr = TmplAttr->clone(SemaRef.Context);
112
113    New->addAttr(NewAttr);
114  }
115}
116
117Decl *
118TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
119  assert(false && "Translation units cannot be instantiated");
120  return D;
121}
122
123Decl *
124TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
125  assert(false && "Namespaces cannot be instantiated");
126  return D;
127}
128
129Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
130  bool Invalid = false;
131  TypeSourceInfo *DI = D->getTypeSourceInfo();
132  if (DI->getType()->isDependentType()) {
133    DI = SemaRef.SubstType(DI, TemplateArgs,
134                           D->getLocation(), D->getDeclName());
135    if (!DI) {
136      Invalid = true;
137      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
138    }
139  }
140
141  // Create the new typedef
142  TypedefDecl *Typedef
143    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
144                          D->getIdentifier(), DI);
145  if (Invalid)
146    Typedef->setInvalidDecl();
147
148  Owner->addDecl(Typedef);
149
150  return Typedef;
151}
152
153/// \brief Instantiate the arguments provided as part of initialization.
154///
155/// \returns true if an error occurred, false otherwise.
156static bool InstantiateInitializationArguments(Sema &SemaRef,
157                                               Expr **Args, unsigned NumArgs,
158                           const MultiLevelTemplateArgumentList &TemplateArgs,
159                         llvm::SmallVectorImpl<SourceLocation> &FakeCommaLocs,
160                           ASTOwningVector<&ActionBase::DeleteExpr> &InitArgs) {
161  for (unsigned I = 0; I != NumArgs; ++I) {
162    // When we hit the first defaulted argument, break out of the loop:
163    // we don't pass those default arguments on.
164    if (Args[I]->isDefaultArgument())
165      break;
166
167    Sema::OwningExprResult Arg = SemaRef.SubstExpr(Args[I], TemplateArgs);
168    if (Arg.isInvalid())
169      return true;
170
171    Expr *ArgExpr = (Expr *)Arg.get();
172    InitArgs.push_back(Arg.release());
173
174    // FIXME: We're faking all of the comma locations. Do we need them?
175    FakeCommaLocs.push_back(
176                          SemaRef.PP.getLocForEndOfToken(ArgExpr->getLocEnd()));
177  }
178
179  return false;
180}
181
182Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
183  // Do substitution on the type of the declaration
184  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
185                                         TemplateArgs,
186                                         D->getTypeSpecStartLoc(),
187                                         D->getDeclName());
188  if (!DI)
189    return 0;
190
191  // Build the instantiated declaration
192  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
193                                 D->getLocation(), D->getIdentifier(),
194                                 DI->getType(), DI,
195                                 D->getStorageClass());
196  Var->setThreadSpecified(D->isThreadSpecified());
197  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
198  Var->setDeclaredInCondition(D->isDeclaredInCondition());
199
200  // If we are instantiating a static data member defined
201  // out-of-line, the instantiation will have the same lexical
202  // context (which will be a namespace scope) as the template.
203  if (D->isOutOfLine())
204    Var->setLexicalDeclContext(D->getLexicalDeclContext());
205
206  // FIXME: In theory, we could have a previous declaration for variables that
207  // are not static data members.
208  bool Redeclaration = false;
209  // FIXME: having to fake up a LookupResult is dumb.
210  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
211                        Sema::LookupOrdinaryName);
212  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
213
214  if (D->isOutOfLine()) {
215    D->getLexicalDeclContext()->addDecl(Var);
216    Owner->makeDeclVisibleInContext(Var);
217  } else {
218    Owner->addDecl(Var);
219  }
220
221  // Link instantiations of static data members back to the template from
222  // which they were instantiated.
223  if (Var->isStaticDataMember())
224    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
225                                                     TSK_ImplicitInstantiation);
226
227  if (D->getInit()) {
228    if (Var->isStaticDataMember() && !D->isOutOfLine())
229      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
230    else
231      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
232
233    // Extract the initializer, skipping through any temporary-binding
234    // expressions and look at the subexpression as it was written.
235    Expr *DInit = D->getInit();
236    while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(DInit))
237      DInit = Binder->getSubExpr();
238    if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(DInit))
239      DInit = ICE->getSubExprAsWritten();
240
241    if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(DInit)) {
242      // The initializer is a parenthesized list of expressions that is
243      // type-dependent. Instantiate each of the expressions; we'll be
244      // performing direct initialization with them.
245      llvm::SmallVector<SourceLocation, 4> CommaLocs;
246      ASTOwningVector<&ActionBase::DeleteExpr> InitArgs(SemaRef);
247      if (!InstantiateInitializationArguments(SemaRef,
248                                              PLE->getExprs(),
249                                              PLE->getNumExprs(),
250                                              TemplateArgs,
251                                              CommaLocs, InitArgs)) {
252        // Add the direct initializer to the declaration.
253        SemaRef.AddCXXDirectInitializerToDecl(Sema::DeclPtrTy::make(Var),
254                                              PLE->getLParenLoc(),
255                                              move_arg(InitArgs),
256                                              CommaLocs.data(),
257                                              PLE->getRParenLoc());
258      }
259    } else if (CXXConstructExpr *Construct =dyn_cast<CXXConstructExpr>(DInit)) {
260      // The initializer resolved to a constructor. Instantiate the constructor
261      // arguments.
262      llvm::SmallVector<SourceLocation, 4> CommaLocs;
263      ASTOwningVector<&ActionBase::DeleteExpr> InitArgs(SemaRef);
264
265      if (!InstantiateInitializationArguments(SemaRef,
266                                              Construct->getArgs(),
267                                              Construct->getNumArgs(),
268                                              TemplateArgs,
269                                              CommaLocs, InitArgs)) {
270        if (D->hasCXXDirectInitializer()) {
271          SourceLocation FakeLParenLoc =
272            SemaRef.PP.getLocForEndOfToken(D->getLocation());
273          SourceLocation FakeRParenLoc = CommaLocs.empty()? FakeLParenLoc
274                                                          : CommaLocs.back();
275          SemaRef.AddCXXDirectInitializerToDecl(Sema::DeclPtrTy::make(Var),
276                                                FakeLParenLoc,
277                                                move_arg(InitArgs),
278                                                CommaLocs.data(),
279                                                FakeRParenLoc);
280        } else if (InitArgs.size() == 1) {
281          Expr *Init = (Expr*)(InitArgs.take()[0]);
282          SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var),
283                                       SemaRef.Owned(Init),
284                                       false);
285        } else {
286          assert(InitArgs.size() == 0);
287          SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
288        }
289      }
290    } else {
291      OwningExprResult Init
292        = SemaRef.SubstExpr(D->getInit(), TemplateArgs);
293
294      // FIXME: Not happy about invalidating decls just because of a bad
295      // initializer, unless it affects the type.
296      if (Init.isInvalid())
297        Var->setInvalidDecl();
298      else
299        SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var), move(Init),
300                                     D->hasCXXDirectInitializer());
301    }
302
303    SemaRef.PopExpressionEvaluationContext();
304  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
305    SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
306
307  return Var;
308}
309
310Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
311  bool Invalid = false;
312  TypeSourceInfo *DI = D->getTypeSourceInfo();
313  if (DI->getType()->isDependentType())  {
314    DI = SemaRef.SubstType(DI, TemplateArgs,
315                           D->getLocation(), D->getDeclName());
316    if (!DI) {
317      DI = D->getTypeSourceInfo();
318      Invalid = true;
319    } else if (DI->getType()->isFunctionType()) {
320      // C++ [temp.arg.type]p3:
321      //   If a declaration acquires a function type through a type
322      //   dependent on a template-parameter and this causes a
323      //   declaration that does not use the syntactic form of a
324      //   function declarator to have function type, the program is
325      //   ill-formed.
326      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
327        << DI->getType();
328      Invalid = true;
329    }
330  }
331
332  Expr *BitWidth = D->getBitWidth();
333  if (Invalid)
334    BitWidth = 0;
335  else if (BitWidth) {
336    // The bit-width expression is not potentially evaluated.
337    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
338
339    OwningExprResult InstantiatedBitWidth
340      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
341    if (InstantiatedBitWidth.isInvalid()) {
342      Invalid = true;
343      BitWidth = 0;
344    } else
345      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
346  }
347
348  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
349                                            DI->getType(), DI,
350                                            cast<RecordDecl>(Owner),
351                                            D->getLocation(),
352                                            D->isMutable(),
353                                            BitWidth,
354                                            D->getTypeSpecStartLoc(),
355                                            D->getAccess(),
356                                            0);
357  if (!Field) {
358    cast<Decl>(Owner)->setInvalidDecl();
359    return 0;
360  }
361
362  InstantiateAttrs(D, Field);
363
364  if (Invalid)
365    Field->setInvalidDecl();
366
367  if (!Field->getDeclName()) {
368    // Keep track of where this decl came from.
369    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
370  }
371
372  Field->setImplicit(D->isImplicit());
373  Owner->addDecl(Field);
374
375  return Field;
376}
377
378Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
379  FriendDecl::FriendUnion FU;
380
381  // Handle friend type expressions by simply substituting template
382  // parameters into the pattern type.
383  if (Type *Ty = D->getFriendType()) {
384    QualType T = SemaRef.SubstType(QualType(Ty,0), TemplateArgs,
385                                   D->getLocation(), DeclarationName());
386    if (T.isNull()) return 0;
387
388    assert(getLangOptions().CPlusPlus0x || T->isRecordType());
389    FU = T.getTypePtr();
390
391  // Handle everything else by appropriate substitution.
392  } else {
393    NamedDecl *ND = D->getFriendDecl();
394    assert(ND && "friend decl must be a decl or a type!");
395
396    // FIXME: We have a problem here, because the nested call to Visit(ND)
397    // will inject the thing that the friend references into the current
398    // owner, which is wrong.
399    Decl *NewND;
400
401    // Hack to make this work almost well pending a rewrite.
402    if (ND->getDeclContext()->isRecord())
403      NewND = SemaRef.FindInstantiatedDecl(ND, TemplateArgs);
404    else
405      NewND = Visit(ND);
406    if (!NewND) return 0;
407
408    FU = cast<NamedDecl>(NewND);
409  }
410
411  FriendDecl *FD =
412    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(), FU,
413                       D->getFriendLoc());
414  FD->setAccess(AS_public);
415  Owner->addDecl(FD);
416  return FD;
417}
418
419Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
420  Expr *AssertExpr = D->getAssertExpr();
421
422  // The expression in a static assertion is not potentially evaluated.
423  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
424
425  OwningExprResult InstantiatedAssertExpr
426    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
427  if (InstantiatedAssertExpr.isInvalid())
428    return 0;
429
430  OwningExprResult Message(SemaRef, D->getMessage());
431  D->getMessage()->Retain();
432  Decl *StaticAssert
433    = SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
434                                           move(InstantiatedAssertExpr),
435                                           move(Message)).getAs<Decl>();
436  return StaticAssert;
437}
438
439Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
440  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
441                                    D->getLocation(), D->getIdentifier(),
442                                    D->getTagKeywordLoc(),
443                                    /*PrevDecl=*/0);
444  Enum->setInstantiationOfMemberEnum(D);
445  Enum->setAccess(D->getAccess());
446  Owner->addDecl(Enum);
447  Enum->startDefinition();
448
449  llvm::SmallVector<Sema::DeclPtrTy, 4> Enumerators;
450
451  EnumConstantDecl *LastEnumConst = 0;
452  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
453         ECEnd = D->enumerator_end();
454       EC != ECEnd; ++EC) {
455    // The specified value for the enumerator.
456    OwningExprResult Value = SemaRef.Owned((Expr *)0);
457    if (Expr *UninstValue = EC->getInitExpr()) {
458      // The enumerator's value expression is not potentially evaluated.
459      EnterExpressionEvaluationContext Unevaluated(SemaRef,
460                                                   Action::Unevaluated);
461
462      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
463    }
464
465    // Drop the initial value and continue.
466    bool isInvalid = false;
467    if (Value.isInvalid()) {
468      Value = SemaRef.Owned((Expr *)0);
469      isInvalid = true;
470    }
471
472    EnumConstantDecl *EnumConst
473      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
474                                  EC->getLocation(), EC->getIdentifier(),
475                                  move(Value));
476
477    if (isInvalid) {
478      if (EnumConst)
479        EnumConst->setInvalidDecl();
480      Enum->setInvalidDecl();
481    }
482
483    if (EnumConst) {
484      Enum->addDecl(EnumConst);
485      Enumerators.push_back(Sema::DeclPtrTy::make(EnumConst));
486      LastEnumConst = EnumConst;
487    }
488  }
489
490  // FIXME: Fixup LBraceLoc and RBraceLoc
491  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
492  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
493                        Sema::DeclPtrTy::make(Enum),
494                        &Enumerators[0], Enumerators.size(),
495                        0, 0);
496
497  return Enum;
498}
499
500Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
501  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
502  return 0;
503}
504
505namespace {
506  class SortDeclByLocation {
507    SourceManager &SourceMgr;
508
509  public:
510    explicit SortDeclByLocation(SourceManager &SourceMgr)
511      : SourceMgr(SourceMgr) { }
512
513    bool operator()(const Decl *X, const Decl *Y) const {
514      return SourceMgr.isBeforeInTranslationUnit(X->getLocation(),
515                                                 Y->getLocation());
516    }
517  };
518}
519
520Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
521  // Create a local instantiation scope for this class template, which
522  // will contain the instantiations of the template parameters.
523  Sema::LocalInstantiationScope Scope(SemaRef);
524  TemplateParameterList *TempParams = D->getTemplateParameters();
525  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
526  if (!InstParams)
527    return NULL;
528
529  CXXRecordDecl *Pattern = D->getTemplatedDecl();
530  CXXRecordDecl *RecordInst
531    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), Owner,
532                            Pattern->getLocation(), Pattern->getIdentifier(),
533                            Pattern->getTagKeywordLoc(), /*PrevDecl=*/ NULL,
534                            /*DelayTypeCreation=*/true);
535
536  ClassTemplateDecl *Inst
537    = ClassTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
538                                D->getIdentifier(), InstParams, RecordInst, 0);
539  RecordInst->setDescribedClassTemplate(Inst);
540  if (D->getFriendObjectKind())
541    Inst->setObjectOfFriendDecl(true);
542  else
543    Inst->setAccess(D->getAccess());
544  Inst->setInstantiatedFromMemberTemplate(D);
545
546  // Trigger creation of the type for the instantiation.
547  SemaRef.Context.getTypeDeclType(RecordInst);
548
549  // Finish handling of friends.
550  if (Inst->getFriendObjectKind()) {
551    return Inst;
552  }
553
554  Owner->addDecl(Inst);
555
556  // First, we sort the partial specializations by location, so
557  // that we instantiate them in the order they were declared.
558  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
559  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
560         P = D->getPartialSpecializations().begin(),
561         PEnd = D->getPartialSpecializations().end();
562       P != PEnd; ++P)
563    PartialSpecs.push_back(&*P);
564  std::sort(PartialSpecs.begin(), PartialSpecs.end(),
565            SortDeclByLocation(SemaRef.SourceMgr));
566
567  // Instantiate all of the partial specializations of this member class
568  // template.
569  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
570    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
571
572  return Inst;
573}
574
575Decl *
576TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
577                                   ClassTemplatePartialSpecializationDecl *D) {
578  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
579
580  // Lookup the already-instantiated declaration in the instantiation
581  // of the class template and return that.
582  DeclContext::lookup_result Found
583    = Owner->lookup(ClassTemplate->getDeclName());
584  if (Found.first == Found.second)
585    return 0;
586
587  ClassTemplateDecl *InstClassTemplate
588    = dyn_cast<ClassTemplateDecl>(*Found.first);
589  if (!InstClassTemplate)
590    return 0;
591
592  Decl *DCanon = D->getCanonicalDecl();
593  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
594            P = InstClassTemplate->getPartialSpecializations().begin(),
595         PEnd = InstClassTemplate->getPartialSpecializations().end();
596       P != PEnd; ++P) {
597    if (P->getInstantiatedFromMember()->getCanonicalDecl() == DCanon)
598      return &*P;
599  }
600
601  return 0;
602}
603
604Decl *
605TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
606  // Create a local instantiation scope for this function template, which
607  // will contain the instantiations of the template parameters and then get
608  // merged with the local instantiation scope for the function template
609  // itself.
610  Sema::LocalInstantiationScope Scope(SemaRef);
611
612  TemplateParameterList *TempParams = D->getTemplateParameters();
613  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
614  if (!InstParams)
615    return NULL;
616
617  FunctionDecl *Instantiated = 0;
618  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
619    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
620                                                                 InstParams));
621  else
622    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
623                                                          D->getTemplatedDecl(),
624                                                                InstParams));
625
626  if (!Instantiated)
627    return 0;
628
629  // Link the instantiated function template declaration to the function
630  // template from which it was instantiated.
631  FunctionTemplateDecl *InstTemplate
632    = Instantiated->getDescribedFunctionTemplate();
633  InstTemplate->setAccess(D->getAccess());
634  assert(InstTemplate &&
635         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
636
637  // Link the instantiation back to the pattern *unless* this is a
638  // non-definition friend declaration.
639  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
640      !(InstTemplate->getFriendObjectKind() &&
641        !D->getTemplatedDecl()->isThisDeclarationADefinition()))
642    InstTemplate->setInstantiatedFromMemberTemplate(D);
643
644  // Add non-friends into the owner.
645  if (!InstTemplate->getFriendObjectKind())
646    Owner->addDecl(InstTemplate);
647  return InstTemplate;
648}
649
650Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
651  CXXRecordDecl *PrevDecl = 0;
652  if (D->isInjectedClassName())
653    PrevDecl = cast<CXXRecordDecl>(Owner);
654  else if (D->getPreviousDeclaration()) {
655    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getPreviousDeclaration(),
656                                                   TemplateArgs);
657    if (!Prev) return 0;
658    PrevDecl = cast<CXXRecordDecl>(Prev);
659  }
660
661  CXXRecordDecl *Record
662    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
663                            D->getLocation(), D->getIdentifier(),
664                            D->getTagKeywordLoc(), PrevDecl);
665  Record->setImplicit(D->isImplicit());
666  // FIXME: Check against AS_none is an ugly hack to work around the issue that
667  // the tag decls introduced by friend class declarations don't have an access
668  // specifier. Remove once this area of the code gets sorted out.
669  if (D->getAccess() != AS_none)
670    Record->setAccess(D->getAccess());
671  if (!D->isInjectedClassName())
672    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
673
674  // If the original function was part of a friend declaration,
675  // inherit its namespace state.
676  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
677    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
678
679  Record->setAnonymousStructOrUnion(D->isAnonymousStructOrUnion());
680
681  Owner->addDecl(Record);
682  return Record;
683}
684
685/// Normal class members are of more specific types and therefore
686/// don't make it here.  This function serves two purposes:
687///   1) instantiating function templates
688///   2) substituting friend declarations
689/// FIXME: preserve function definitions in case #2
690  Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
691                                       TemplateParameterList *TemplateParams) {
692  // Check whether there is already a function template specialization for
693  // this declaration.
694  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
695  void *InsertPos = 0;
696  if (FunctionTemplate && !TemplateParams) {
697    llvm::FoldingSetNodeID ID;
698    FunctionTemplateSpecializationInfo::Profile(ID,
699                             TemplateArgs.getInnermost().getFlatArgumentList(),
700                                       TemplateArgs.getInnermost().flat_size(),
701                                                SemaRef.Context);
702
703    FunctionTemplateSpecializationInfo *Info
704      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
705                                                                   InsertPos);
706
707    // If we already have a function template specialization, return it.
708    if (Info)
709      return Info->Function;
710  }
711
712  Sema::LocalInstantiationScope Scope(SemaRef, TemplateParams != 0);
713
714  llvm::SmallVector<ParmVarDecl *, 4> Params;
715  QualType T = SubstFunctionType(D, Params);
716  if (T.isNull())
717    return 0;
718
719  // Build the instantiated method declaration.
720  DeclContext *DC = SemaRef.FindInstantiatedContext(D->getDeclContext(),
721                                                    TemplateArgs);
722  FunctionDecl *Function =
723      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
724                           D->getDeclName(), T, D->getTypeSourceInfo(),
725                           D->getStorageClass(),
726                           D->isInlineSpecified(), D->hasWrittenPrototype());
727  Function->setLexicalDeclContext(Owner);
728
729  // Attach the parameters
730  for (unsigned P = 0; P < Params.size(); ++P)
731    Params[P]->setOwningFunction(Function);
732  Function->setParams(SemaRef.Context, Params.data(), Params.size());
733
734  if (TemplateParams) {
735    // Our resulting instantiation is actually a function template, since we
736    // are substituting only the outer template parameters. For example, given
737    //
738    //   template<typename T>
739    //   struct X {
740    //     template<typename U> friend void f(T, U);
741    //   };
742    //
743    //   X<int> x;
744    //
745    // We are instantiating the friend function template "f" within X<int>,
746    // which means substituting int for T, but leaving "f" as a friend function
747    // template.
748    // Build the function template itself.
749    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Owner,
750                                                    Function->getLocation(),
751                                                    Function->getDeclName(),
752                                                    TemplateParams, Function);
753    Function->setDescribedFunctionTemplate(FunctionTemplate);
754    FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
755  } else if (FunctionTemplate) {
756    // Record this function template specialization.
757    Function->setFunctionTemplateSpecialization(SemaRef.Context,
758                                                FunctionTemplate,
759                                                &TemplateArgs.getInnermost(),
760                                                InsertPos);
761  }
762
763  if (InitFunctionInstantiation(Function, D))
764    Function->setInvalidDecl();
765
766  bool Redeclaration = false;
767  bool OverloadableAttrRequired = false;
768
769  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
770                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
771
772  if (TemplateParams || !FunctionTemplate) {
773    // Look only into the namespace where the friend would be declared to
774    // find a previous declaration. This is the innermost enclosing namespace,
775    // as described in ActOnFriendFunctionDecl.
776    SemaRef.LookupQualifiedName(Previous, DC);
777
778    // In C++, the previous declaration we find might be a tag type
779    // (class or enum). In this case, the new declaration will hide the
780    // tag type. Note that this does does not apply if we're declaring a
781    // typedef (C++ [dcl.typedef]p4).
782    if (Previous.isSingleTagDecl())
783      Previous.clear();
784  }
785
786  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
787                                   false, Redeclaration,
788                                   /*FIXME:*/OverloadableAttrRequired);
789
790  // If the original function was part of a friend declaration,
791  // inherit its namespace state and add it to the owner.
792  NamedDecl *FromFriendD
793      = TemplateParams? cast<NamedDecl>(D->getDescribedFunctionTemplate()) : D;
794  if (FromFriendD->getFriendObjectKind()) {
795    NamedDecl *ToFriendD = 0;
796    NamedDecl *PrevDecl;
797    if (TemplateParams) {
798      ToFriendD = cast<NamedDecl>(FunctionTemplate);
799      PrevDecl = FunctionTemplate->getPreviousDeclaration();
800    } else {
801      ToFriendD = Function;
802      PrevDecl = Function->getPreviousDeclaration();
803    }
804    ToFriendD->setObjectOfFriendDecl(PrevDecl != NULL);
805    if (!Owner->isDependentContext() && !PrevDecl)
806      DC->makeDeclVisibleInContext(ToFriendD, /* Recoverable = */ false);
807
808    if (!TemplateParams)
809      Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
810  }
811
812  return Function;
813}
814
815Decl *
816TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
817                                      TemplateParameterList *TemplateParams) {
818  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
819  void *InsertPos = 0;
820  if (FunctionTemplate && !TemplateParams) {
821    // We are creating a function template specialization from a function
822    // template. Check whether there is already a function template
823    // specialization for this particular set of template arguments.
824    llvm::FoldingSetNodeID ID;
825    FunctionTemplateSpecializationInfo::Profile(ID,
826                            TemplateArgs.getInnermost().getFlatArgumentList(),
827                                      TemplateArgs.getInnermost().flat_size(),
828                                                SemaRef.Context);
829
830    FunctionTemplateSpecializationInfo *Info
831      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
832                                                                   InsertPos);
833
834    // If we already have a function template specialization, return it.
835    if (Info)
836      return Info->Function;
837  }
838
839  Sema::LocalInstantiationScope Scope(SemaRef, TemplateParams != 0);
840
841  llvm::SmallVector<ParmVarDecl *, 4> Params;
842  QualType T = SubstFunctionType(D, Params);
843  if (T.isNull())
844    return 0;
845
846  // Build the instantiated method declaration.
847  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
848  CXXMethodDecl *Method = 0;
849
850  DeclarationName Name = D->getDeclName();
851  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
852    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
853    Name = SemaRef.Context.DeclarationNames.getCXXConstructorName(
854                                    SemaRef.Context.getCanonicalType(ClassTy));
855    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
856                                        Constructor->getLocation(),
857                                        Name, T,
858                                        Constructor->getTypeSourceInfo(),
859                                        Constructor->isExplicit(),
860                                        Constructor->isInlineSpecified(), false);
861  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
862    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
863    Name = SemaRef.Context.DeclarationNames.getCXXDestructorName(
864                                   SemaRef.Context.getCanonicalType(ClassTy));
865    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
866                                       Destructor->getLocation(), Name,
867                                       T, Destructor->isInlineSpecified(), false);
868  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
869    CanQualType ConvTy
870      = SemaRef.Context.getCanonicalType(
871                                      T->getAs<FunctionType>()->getResultType());
872    Name = SemaRef.Context.DeclarationNames.getCXXConversionFunctionName(
873                                                                      ConvTy);
874    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
875                                       Conversion->getLocation(), Name,
876                                       T, Conversion->getTypeSourceInfo(),
877                                       Conversion->isInlineSpecified(),
878                                       Conversion->isExplicit());
879  } else {
880    Method = CXXMethodDecl::Create(SemaRef.Context, Record, D->getLocation(),
881                                   D->getDeclName(), T, D->getTypeSourceInfo(),
882                                   D->isStatic(), D->isInlineSpecified());
883  }
884
885  if (TemplateParams) {
886    // Our resulting instantiation is actually a function template, since we
887    // are substituting only the outer template parameters. For example, given
888    //
889    //   template<typename T>
890    //   struct X {
891    //     template<typename U> void f(T, U);
892    //   };
893    //
894    //   X<int> x;
895    //
896    // We are instantiating the member template "f" within X<int>, which means
897    // substituting int for T, but leaving "f" as a member function template.
898    // Build the function template itself.
899    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
900                                                    Method->getLocation(),
901                                                    Method->getDeclName(),
902                                                    TemplateParams, Method);
903    if (D->isOutOfLine())
904      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
905    Method->setDescribedFunctionTemplate(FunctionTemplate);
906  } else if (FunctionTemplate) {
907    // Record this function template specialization.
908    Method->setFunctionTemplateSpecialization(SemaRef.Context,
909                                              FunctionTemplate,
910                                              &TemplateArgs.getInnermost(),
911                                              InsertPos);
912  } else {
913    // Record that this is an instantiation of a member function.
914    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
915  }
916
917  // If we are instantiating a member function defined
918  // out-of-line, the instantiation will have the same lexical
919  // context (which will be a namespace scope) as the template.
920  if (D->isOutOfLine())
921    Method->setLexicalDeclContext(D->getLexicalDeclContext());
922
923  // Attach the parameters
924  for (unsigned P = 0; P < Params.size(); ++P)
925    Params[P]->setOwningFunction(Method);
926  Method->setParams(SemaRef.Context, Params.data(), Params.size());
927
928  if (InitMethodInstantiation(Method, D))
929    Method->setInvalidDecl();
930
931  LookupResult Previous(SemaRef, Name, SourceLocation(),
932                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
933
934  if (!FunctionTemplate || TemplateParams) {
935    SemaRef.LookupQualifiedName(Previous, Owner);
936
937    // In C++, the previous declaration we find might be a tag type
938    // (class or enum). In this case, the new declaration will hide the
939    // tag type. Note that this does does not apply if we're declaring a
940    // typedef (C++ [dcl.typedef]p4).
941    if (Previous.isSingleTagDecl())
942      Previous.clear();
943  }
944
945  bool Redeclaration = false;
946  bool OverloadableAttrRequired = false;
947  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
948                                   /*FIXME:*/OverloadableAttrRequired);
949
950  if (D->isPure())
951    SemaRef.CheckPureMethod(Method, SourceRange());
952
953  if (!FunctionTemplate && (!Method->isInvalidDecl() || Previous.empty()) &&
954      !Method->getFriendObjectKind())
955    Owner->addDecl(Method);
956
957  return Method;
958}
959
960Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
961  return VisitCXXMethodDecl(D);
962}
963
964Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
965  return VisitCXXMethodDecl(D);
966}
967
968Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
969  return VisitCXXMethodDecl(D);
970}
971
972ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
973  QualType T;
974  TypeSourceInfo *DI = D->getTypeSourceInfo();
975  if (DI) {
976    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
977                           D->getDeclName());
978    if (DI) T = DI->getType();
979  } else {
980    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
981                          D->getDeclName());
982    DI = 0;
983  }
984
985  if (T.isNull())
986    return 0;
987
988  T = SemaRef.adjustParameterType(T);
989
990  // Allocate the parameter
991  ParmVarDecl *Param
992    = ParmVarDecl::Create(SemaRef.Context, Owner, D->getLocation(),
993                          D->getIdentifier(), T, DI, D->getStorageClass(), 0);
994
995  // Mark the default argument as being uninstantiated.
996  if (D->hasUninstantiatedDefaultArg())
997    Param->setUninstantiatedDefaultArg(D->getUninstantiatedDefaultArg());
998  else if (Expr *Arg = D->getDefaultArg())
999    Param->setUninstantiatedDefaultArg(Arg);
1000
1001  // Note: we don't try to instantiate function parameters until after
1002  // we've instantiated the function's type. Therefore, we don't have
1003  // to check for 'void' parameter types here.
1004  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1005  return Param;
1006}
1007
1008Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1009                                                    TemplateTypeParmDecl *D) {
1010  // TODO: don't always clone when decls are refcounted.
1011  const Type* T = D->getTypeForDecl();
1012  assert(T->isTemplateTypeParmType());
1013  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1014
1015  TemplateTypeParmDecl *Inst =
1016    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1017                                 TTPT->getDepth() - 1, TTPT->getIndex(),
1018                                 TTPT->getName(),
1019                                 D->wasDeclaredWithTypename(),
1020                                 D->isParameterPack());
1021
1022  if (D->hasDefaultArgument())
1023    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1024
1025  // Introduce this template parameter's instantiation into the instantiation
1026  // scope.
1027  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1028
1029  return Inst;
1030}
1031
1032Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1033                                                 NonTypeTemplateParmDecl *D) {
1034  // Substitute into the type of the non-type template parameter.
1035  QualType T;
1036  TypeSourceInfo *DI = D->getTypeSourceInfo();
1037  if (DI) {
1038    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1039                           D->getDeclName());
1040    if (DI) T = DI->getType();
1041  } else {
1042    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1043                          D->getDeclName());
1044    DI = 0;
1045  }
1046  if (T.isNull())
1047    return 0;
1048
1049  // Check that this type is acceptable for a non-type template parameter.
1050  bool Invalid = false;
1051  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1052  if (T.isNull()) {
1053    T = SemaRef.Context.IntTy;
1054    Invalid = true;
1055  }
1056
1057  NonTypeTemplateParmDecl *Param
1058    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1059                                      D->getDepth() - 1, D->getPosition(),
1060                                      D->getIdentifier(), T, DI);
1061  if (Invalid)
1062    Param->setInvalidDecl();
1063
1064  Param->setDefaultArgument(D->getDefaultArgument());
1065
1066  // Introduce this template parameter's instantiation into the instantiation
1067  // scope.
1068  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1069  return Param;
1070}
1071
1072Decl *
1073TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1074                                                  TemplateTemplateParmDecl *D) {
1075  // Instantiate the template parameter list of the template template parameter.
1076  TemplateParameterList *TempParams = D->getTemplateParameters();
1077  TemplateParameterList *InstParams;
1078  {
1079    // Perform the actual substitution of template parameters within a new,
1080    // local instantiation scope.
1081    Sema::LocalInstantiationScope Scope(SemaRef);
1082    InstParams = SubstTemplateParams(TempParams);
1083    if (!InstParams)
1084      return NULL;
1085  }
1086
1087  // Build the template template parameter.
1088  TemplateTemplateParmDecl *Param
1089    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1090                                       D->getDepth() - 1, D->getPosition(),
1091                                       D->getIdentifier(), InstParams);
1092  Param->setDefaultArgument(D->getDefaultArgument());
1093
1094  // Introduce this template parameter's instantiation into the instantiation
1095  // scope.
1096  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1097
1098  return Param;
1099}
1100
1101Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1102  // Using directives are never dependent, so they require no explicit
1103
1104  UsingDirectiveDecl *Inst
1105    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1106                                 D->getNamespaceKeyLocation(),
1107                                 D->getQualifierRange(), D->getQualifier(),
1108                                 D->getIdentLocation(),
1109                                 D->getNominatedNamespace(),
1110                                 D->getCommonAncestor());
1111  Owner->addDecl(Inst);
1112  return Inst;
1113}
1114
1115Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1116  // The nested name specifier is non-dependent, so no transformation
1117  // is required.
1118
1119  // We only need to do redeclaration lookups if we're in a class
1120  // scope (in fact, it's not really even possible in non-class
1121  // scopes).
1122  bool CheckRedeclaration = Owner->isRecord();
1123
1124  LookupResult Prev(SemaRef, D->getDeclName(), D->getLocation(),
1125                    Sema::LookupUsingDeclName, Sema::ForRedeclaration);
1126
1127  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1128                                       D->getLocation(),
1129                                       D->getNestedNameRange(),
1130                                       D->getUsingLocation(),
1131                                       D->getTargetNestedNameDecl(),
1132                                       D->getDeclName(),
1133                                       D->isTypeName());
1134
1135  CXXScopeSpec SS;
1136  SS.setScopeRep(D->getTargetNestedNameDecl());
1137  SS.setRange(D->getNestedNameRange());
1138
1139  if (CheckRedeclaration) {
1140    Prev.setHideTags(false);
1141    SemaRef.LookupQualifiedName(Prev, Owner);
1142
1143    // Check for invalid redeclarations.
1144    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1145                                            D->isTypeName(), SS,
1146                                            D->getLocation(), Prev))
1147      NewUD->setInvalidDecl();
1148
1149  }
1150
1151  if (!NewUD->isInvalidDecl() &&
1152      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1153                                      D->getLocation()))
1154    NewUD->setInvalidDecl();
1155
1156  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1157  NewUD->setAccess(D->getAccess());
1158  Owner->addDecl(NewUD);
1159
1160  // Don't process the shadow decls for an invalid decl.
1161  if (NewUD->isInvalidDecl())
1162    return NewUD;
1163
1164  // Process the shadow decls.
1165  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1166         I != E; ++I) {
1167    UsingShadowDecl *Shadow = *I;
1168    NamedDecl *InstTarget =
1169      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getTargetDecl(),
1170                                                   TemplateArgs));
1171
1172    if (CheckRedeclaration &&
1173        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1174      continue;
1175
1176    UsingShadowDecl *InstShadow
1177      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1178    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1179  }
1180
1181  return NewUD;
1182}
1183
1184Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1185  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1186  return 0;
1187}
1188
1189Decl * TemplateDeclInstantiator
1190    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1191  NestedNameSpecifier *NNS =
1192    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1193                                     D->getTargetNestedNameRange(),
1194                                     TemplateArgs);
1195  if (!NNS)
1196    return 0;
1197
1198  CXXScopeSpec SS;
1199  SS.setRange(D->getTargetNestedNameRange());
1200  SS.setScopeRep(NNS);
1201
1202  NamedDecl *UD =
1203    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1204                                  D->getUsingLoc(), SS, D->getLocation(),
1205                                  D->getDeclName(), 0,
1206                                  /*instantiation*/ true,
1207                                  /*typename*/ true, D->getTypenameLoc());
1208  if (UD)
1209    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1210
1211  return UD;
1212}
1213
1214Decl * TemplateDeclInstantiator
1215    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1216  NestedNameSpecifier *NNS =
1217    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1218                                     D->getTargetNestedNameRange(),
1219                                     TemplateArgs);
1220  if (!NNS)
1221    return 0;
1222
1223  CXXScopeSpec SS;
1224  SS.setRange(D->getTargetNestedNameRange());
1225  SS.setScopeRep(NNS);
1226
1227  NamedDecl *UD =
1228    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1229                                  D->getUsingLoc(), SS, D->getLocation(),
1230                                  D->getDeclName(), 0,
1231                                  /*instantiation*/ true,
1232                                  /*typename*/ false, SourceLocation());
1233  if (UD)
1234    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1235
1236  return UD;
1237}
1238
1239Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1240                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1241  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1242  return Instantiator.Visit(D);
1243}
1244
1245/// \brief Instantiates a nested template parameter list in the current
1246/// instantiation context.
1247///
1248/// \param L The parameter list to instantiate
1249///
1250/// \returns NULL if there was an error
1251TemplateParameterList *
1252TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1253  // Get errors for all the parameters before bailing out.
1254  bool Invalid = false;
1255
1256  unsigned N = L->size();
1257  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1258  ParamVector Params;
1259  Params.reserve(N);
1260  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1261       PI != PE; ++PI) {
1262    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1263    Params.push_back(D);
1264    Invalid = Invalid || !D || D->isInvalidDecl();
1265  }
1266
1267  // Clean up if we had an error.
1268  if (Invalid) {
1269    for (ParamVector::iterator PI = Params.begin(), PE = Params.end();
1270         PI != PE; ++PI)
1271      if (*PI)
1272        (*PI)->Destroy(SemaRef.Context);
1273    return NULL;
1274  }
1275
1276  TemplateParameterList *InstL
1277    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1278                                    L->getLAngleLoc(), &Params.front(), N,
1279                                    L->getRAngleLoc());
1280  return InstL;
1281}
1282
1283/// \brief Instantiate the declaration of a class template partial
1284/// specialization.
1285///
1286/// \param ClassTemplate the (instantiated) class template that is partially
1287// specialized by the instantiation of \p PartialSpec.
1288///
1289/// \param PartialSpec the (uninstantiated) class template partial
1290/// specialization that we are instantiating.
1291///
1292/// \returns true if there was an error, false otherwise.
1293bool
1294TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1295                                            ClassTemplateDecl *ClassTemplate,
1296                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1297  // Create a local instantiation scope for this class template partial
1298  // specialization, which will contain the instantiations of the template
1299  // parameters.
1300  Sema::LocalInstantiationScope Scope(SemaRef);
1301
1302  // Substitute into the template parameters of the class template partial
1303  // specialization.
1304  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1305  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1306  if (!InstParams)
1307    return true;
1308
1309  // Substitute into the template arguments of the class template partial
1310  // specialization.
1311  const TemplateArgumentLoc *PartialSpecTemplateArgs
1312    = PartialSpec->getTemplateArgsAsWritten();
1313  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1314
1315  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1316  for (unsigned I = 0; I != N; ++I) {
1317    TemplateArgumentLoc Loc;
1318    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1319      return true;
1320    InstTemplateArgs.addArgument(Loc);
1321  }
1322
1323
1324  // Check that the template argument list is well-formed for this
1325  // class template.
1326  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1327                                        InstTemplateArgs.size());
1328  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1329                                        PartialSpec->getLocation(),
1330                                        InstTemplateArgs,
1331                                        false,
1332                                        Converted))
1333    return true;
1334
1335  // Figure out where to insert this class template partial specialization
1336  // in the member template's set of class template partial specializations.
1337  llvm::FoldingSetNodeID ID;
1338  ClassTemplatePartialSpecializationDecl::Profile(ID,
1339                                                  Converted.getFlatArguments(),
1340                                                  Converted.flatSize(),
1341                                                  SemaRef.Context);
1342  void *InsertPos = 0;
1343  ClassTemplateSpecializationDecl *PrevDecl
1344    = ClassTemplate->getPartialSpecializations().FindNodeOrInsertPos(ID,
1345                                                                     InsertPos);
1346
1347  // Build the canonical type that describes the converted template
1348  // arguments of the class template partial specialization.
1349  QualType CanonType
1350    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1351                                                  Converted.getFlatArguments(),
1352                                                    Converted.flatSize());
1353
1354  // Build the fully-sugared type for this class template
1355  // specialization as the user wrote in the specialization
1356  // itself. This means that we'll pretty-print the type retrieved
1357  // from the specialization's declaration the way that the user
1358  // actually wrote the specialization, rather than formatting the
1359  // name based on the "canonical" representation used to store the
1360  // template arguments in the specialization.
1361  QualType WrittenTy
1362    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1363                                                    InstTemplateArgs,
1364                                                    CanonType);
1365
1366  if (PrevDecl) {
1367    // We've already seen a partial specialization with the same template
1368    // parameters and template arguments. This can happen, for example, when
1369    // substituting the outer template arguments ends up causing two
1370    // class template partial specializations of a member class template
1371    // to have identical forms, e.g.,
1372    //
1373    //   template<typename T, typename U>
1374    //   struct Outer {
1375    //     template<typename X, typename Y> struct Inner;
1376    //     template<typename Y> struct Inner<T, Y>;
1377    //     template<typename Y> struct Inner<U, Y>;
1378    //   };
1379    //
1380    //   Outer<int, int> outer; // error: the partial specializations of Inner
1381    //                          // have the same signature.
1382    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1383      << WrittenTy;
1384    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1385      << SemaRef.Context.getTypeDeclType(PrevDecl);
1386    return true;
1387  }
1388
1389
1390  // Create the class template partial specialization declaration.
1391  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1392    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context, Owner,
1393                                                     PartialSpec->getLocation(),
1394                                                     InstParams,
1395                                                     ClassTemplate,
1396                                                     Converted,
1397                                                     InstTemplateArgs,
1398                                                     0);
1399  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1400  InstPartialSpec->setTypeAsWritten(WrittenTy);
1401
1402  // Add this partial specialization to the set of class template partial
1403  // specializations.
1404  ClassTemplate->getPartialSpecializations().InsertNode(InstPartialSpec,
1405                                                        InsertPos);
1406  return false;
1407}
1408
1409/// \brief Does substitution on the type of the given function, including
1410/// all of the function parameters.
1411///
1412/// \param D The function whose type will be the basis of the substitution
1413///
1414/// \param Params the instantiated parameter declarations
1415
1416/// \returns the instantiated function's type if successful, a NULL
1417/// type if there was an error.
1418QualType
1419TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1420                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1421  bool InvalidDecl = false;
1422
1423  // Substitute all of the function's formal parameter types.
1424  TemplateDeclInstantiator ParamInstantiator(SemaRef, 0, TemplateArgs);
1425  llvm::SmallVector<QualType, 4> ParamTys;
1426  for (FunctionDecl::param_iterator P = D->param_begin(),
1427                                 PEnd = D->param_end();
1428       P != PEnd; ++P) {
1429    if (ParmVarDecl *PInst = ParamInstantiator.VisitParmVarDecl(*P)) {
1430      if (PInst->getType()->isVoidType()) {
1431        SemaRef.Diag(PInst->getLocation(), diag::err_param_with_void_type);
1432        PInst->setInvalidDecl();
1433      } else if (SemaRef.RequireNonAbstractType(PInst->getLocation(),
1434                                                PInst->getType(),
1435                                                diag::err_abstract_type_in_decl,
1436                                                Sema::AbstractParamType))
1437        PInst->setInvalidDecl();
1438
1439      Params.push_back(PInst);
1440      ParamTys.push_back(PInst->getType());
1441
1442      if (PInst->isInvalidDecl())
1443        InvalidDecl = true;
1444    } else
1445      InvalidDecl = true;
1446  }
1447
1448  // FIXME: Deallocate dead declarations.
1449  if (InvalidDecl)
1450    return QualType();
1451
1452  const FunctionProtoType *Proto = D->getType()->getAs<FunctionProtoType>();
1453  assert(Proto && "Missing prototype?");
1454  QualType ResultType
1455    = SemaRef.SubstType(Proto->getResultType(), TemplateArgs,
1456                        D->getLocation(), D->getDeclName());
1457  if (ResultType.isNull())
1458    return QualType();
1459
1460  return SemaRef.BuildFunctionType(ResultType, ParamTys.data(), ParamTys.size(),
1461                                   Proto->isVariadic(), Proto->getTypeQuals(),
1462                                   D->getLocation(), D->getDeclName());
1463}
1464
1465/// \brief Initializes the common fields of an instantiation function
1466/// declaration (New) from the corresponding fields of its template (Tmpl).
1467///
1468/// \returns true if there was an error
1469bool
1470TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1471                                                    FunctionDecl *Tmpl) {
1472  if (Tmpl->isDeleted())
1473    New->setDeleted();
1474
1475  // If we are performing substituting explicitly-specified template arguments
1476  // or deduced template arguments into a function template and we reach this
1477  // point, we are now past the point where SFINAE applies and have committed
1478  // to keeping the new function template specialization. We therefore
1479  // convert the active template instantiation for the function template
1480  // into a template instantiation for this specific function template
1481  // specialization, which is not a SFINAE context, so that we diagnose any
1482  // further errors in the declaration itself.
1483  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1484  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1485  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1486      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1487    if (FunctionTemplateDecl *FunTmpl
1488          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1489      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1490             "Deduction from the wrong function template?");
1491      (void) FunTmpl;
1492      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1493      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1494      --SemaRef.NonInstantiationEntries;
1495    }
1496  }
1497
1498  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1499  assert(Proto && "Function template without prototype?");
1500
1501  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1502      Proto->getNoReturnAttr()) {
1503    // The function has an exception specification or a "noreturn"
1504    // attribute. Substitute into each of the exception types.
1505    llvm::SmallVector<QualType, 4> Exceptions;
1506    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1507      // FIXME: Poor location information!
1508      QualType T
1509        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1510                            New->getLocation(), New->getDeclName());
1511      if (T.isNull() ||
1512          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1513        continue;
1514
1515      Exceptions.push_back(T);
1516    }
1517
1518    // Rebuild the function type
1519
1520    const FunctionProtoType *NewProto
1521      = New->getType()->getAs<FunctionProtoType>();
1522    assert(NewProto && "Template instantiation without function prototype?");
1523    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1524                                                 NewProto->arg_type_begin(),
1525                                                 NewProto->getNumArgs(),
1526                                                 NewProto->isVariadic(),
1527                                                 NewProto->getTypeQuals(),
1528                                                 Proto->hasExceptionSpec(),
1529                                                 Proto->hasAnyExceptionSpec(),
1530                                                 Exceptions.size(),
1531                                                 Exceptions.data(),
1532                                                 Proto->getNoReturnAttr()));
1533  }
1534
1535  return false;
1536}
1537
1538/// \brief Initializes common fields of an instantiated method
1539/// declaration (New) from the corresponding fields of its template
1540/// (Tmpl).
1541///
1542/// \returns true if there was an error
1543bool
1544TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
1545                                                  CXXMethodDecl *Tmpl) {
1546  if (InitFunctionInstantiation(New, Tmpl))
1547    return true;
1548
1549  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
1550  New->setAccess(Tmpl->getAccess());
1551  if (Tmpl->isVirtualAsWritten())
1552    Record->setMethodAsVirtual(New);
1553
1554  // FIXME: attributes
1555  // FIXME: New needs a pointer to Tmpl
1556  return false;
1557}
1558
1559/// \brief Instantiate the definition of the given function from its
1560/// template.
1561///
1562/// \param PointOfInstantiation the point at which the instantiation was
1563/// required. Note that this is not precisely a "point of instantiation"
1564/// for the function, but it's close.
1565///
1566/// \param Function the already-instantiated declaration of a
1567/// function template specialization or member function of a class template
1568/// specialization.
1569///
1570/// \param Recursive if true, recursively instantiates any functions that
1571/// are required by this instantiation.
1572///
1573/// \param DefinitionRequired if true, then we are performing an explicit
1574/// instantiation where the body of the function is required. Complain if
1575/// there is no such body.
1576void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
1577                                         FunctionDecl *Function,
1578                                         bool Recursive,
1579                                         bool DefinitionRequired) {
1580  if (Function->isInvalidDecl())
1581    return;
1582
1583  assert(!Function->getBody() && "Already instantiated!");
1584
1585  // Never instantiate an explicit specialization.
1586  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
1587    return;
1588
1589  // Find the function body that we'll be substituting.
1590  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
1591  Stmt *Pattern = 0;
1592  if (PatternDecl)
1593    Pattern = PatternDecl->getBody(PatternDecl);
1594
1595  if (!Pattern) {
1596    if (DefinitionRequired) {
1597      if (Function->getPrimaryTemplate())
1598        Diag(PointOfInstantiation,
1599             diag::err_explicit_instantiation_undefined_func_template)
1600          << Function->getPrimaryTemplate();
1601      else
1602        Diag(PointOfInstantiation,
1603             diag::err_explicit_instantiation_undefined_member)
1604          << 1 << Function->getDeclName() << Function->getDeclContext();
1605
1606      if (PatternDecl)
1607        Diag(PatternDecl->getLocation(),
1608             diag::note_explicit_instantiation_here);
1609    }
1610
1611    return;
1612  }
1613
1614  // C++0x [temp.explicit]p9:
1615  //   Except for inline functions, other explicit instantiation declarations
1616  //   have the effect of suppressing the implicit instantiation of the entity
1617  //   to which they refer.
1618  if (Function->getTemplateSpecializationKind()
1619        == TSK_ExplicitInstantiationDeclaration &&
1620      !PatternDecl->isInlined())
1621    return;
1622
1623  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
1624  if (Inst)
1625    return;
1626
1627  // If we're performing recursive template instantiation, create our own
1628  // queue of pending implicit instantiations that we will instantiate later,
1629  // while we're still within our own instantiation context.
1630  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
1631  if (Recursive)
1632    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1633
1634  ActOnStartOfFunctionDef(0, DeclPtrTy::make(Function));
1635
1636  // Introduce a new scope where local variable instantiations will be
1637  // recorded.
1638  LocalInstantiationScope Scope(*this);
1639
1640  // Introduce the instantiated function parameters into the local
1641  // instantiation scope.
1642  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I)
1643    Scope.InstantiatedLocal(PatternDecl->getParamDecl(I),
1644                            Function->getParamDecl(I));
1645
1646  // Enter the scope of this instantiation. We don't use
1647  // PushDeclContext because we don't have a scope.
1648  DeclContext *PreviousContext = CurContext;
1649  CurContext = Function;
1650
1651  MultiLevelTemplateArgumentList TemplateArgs =
1652    getTemplateInstantiationArgs(Function);
1653
1654  // If this is a constructor, instantiate the member initializers.
1655  if (const CXXConstructorDecl *Ctor =
1656        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
1657    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
1658                               TemplateArgs);
1659  }
1660
1661  // Instantiate the function body.
1662  OwningStmtResult Body = SubstStmt(Pattern, TemplateArgs);
1663
1664  if (Body.isInvalid())
1665    Function->setInvalidDecl();
1666
1667  ActOnFinishFunctionBody(DeclPtrTy::make(Function), move(Body),
1668                          /*IsInstantiation=*/true);
1669
1670  CurContext = PreviousContext;
1671
1672  DeclGroupRef DG(Function);
1673  Consumer.HandleTopLevelDecl(DG);
1674
1675  if (Recursive) {
1676    // Instantiate any pending implicit instantiations found during the
1677    // instantiation of this template.
1678    PerformPendingImplicitInstantiations();
1679
1680    // Restore the set of pending implicit instantiations.
1681    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1682  }
1683}
1684
1685/// \brief Instantiate the definition of the given variable from its
1686/// template.
1687///
1688/// \param PointOfInstantiation the point at which the instantiation was
1689/// required. Note that this is not precisely a "point of instantiation"
1690/// for the function, but it's close.
1691///
1692/// \param Var the already-instantiated declaration of a static member
1693/// variable of a class template specialization.
1694///
1695/// \param Recursive if true, recursively instantiates any functions that
1696/// are required by this instantiation.
1697///
1698/// \param DefinitionRequired if true, then we are performing an explicit
1699/// instantiation where an out-of-line definition of the member variable
1700/// is required. Complain if there is no such definition.
1701void Sema::InstantiateStaticDataMemberDefinition(
1702                                          SourceLocation PointOfInstantiation,
1703                                                 VarDecl *Var,
1704                                                 bool Recursive,
1705                                                 bool DefinitionRequired) {
1706  if (Var->isInvalidDecl())
1707    return;
1708
1709  // Find the out-of-line definition of this static data member.
1710  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
1711  assert(Def && "This data member was not instantiated from a template?");
1712  assert(Def->isStaticDataMember() && "Not a static data member?");
1713  Def = Def->getOutOfLineDefinition();
1714
1715  if (!Def) {
1716    // We did not find an out-of-line definition of this static data member,
1717    // so we won't perform any instantiation. Rather, we rely on the user to
1718    // instantiate this definition (or provide a specialization for it) in
1719    // another translation unit.
1720    if (DefinitionRequired) {
1721      Def = Var->getInstantiatedFromStaticDataMember();
1722      Diag(PointOfInstantiation,
1723           diag::err_explicit_instantiation_undefined_member)
1724        << 2 << Var->getDeclName() << Var->getDeclContext();
1725      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
1726    }
1727
1728    return;
1729  }
1730
1731  // Never instantiate an explicit specialization.
1732  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
1733    return;
1734
1735  // C++0x [temp.explicit]p9:
1736  //   Except for inline functions, other explicit instantiation declarations
1737  //   have the effect of suppressing the implicit instantiation of the entity
1738  //   to which they refer.
1739  if (Var->getTemplateSpecializationKind()
1740        == TSK_ExplicitInstantiationDeclaration)
1741    return;
1742
1743  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
1744  if (Inst)
1745    return;
1746
1747  // If we're performing recursive template instantiation, create our own
1748  // queue of pending implicit instantiations that we will instantiate later,
1749  // while we're still within our own instantiation context.
1750  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
1751  if (Recursive)
1752    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1753
1754  // Enter the scope of this instantiation. We don't use
1755  // PushDeclContext because we don't have a scope.
1756  DeclContext *PreviousContext = CurContext;
1757  CurContext = Var->getDeclContext();
1758
1759  VarDecl *OldVar = Var;
1760  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
1761                                          getTemplateInstantiationArgs(Var)));
1762  CurContext = PreviousContext;
1763
1764  if (Var) {
1765    Var->setPreviousDeclaration(OldVar);
1766    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
1767    assert(MSInfo && "Missing member specialization information?");
1768    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
1769                                       MSInfo->getPointOfInstantiation());
1770    DeclGroupRef DG(Var);
1771    Consumer.HandleTopLevelDecl(DG);
1772  }
1773
1774  if (Recursive) {
1775    // Instantiate any pending implicit instantiations found during the
1776    // instantiation of this template.
1777    PerformPendingImplicitInstantiations();
1778
1779    // Restore the set of pending implicit instantiations.
1780    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1781  }
1782}
1783
1784void
1785Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
1786                                 const CXXConstructorDecl *Tmpl,
1787                           const MultiLevelTemplateArgumentList &TemplateArgs) {
1788
1789  llvm::SmallVector<MemInitTy*, 4> NewInits;
1790
1791  // Instantiate all the initializers.
1792  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
1793                                            InitsEnd = Tmpl->init_end();
1794       Inits != InitsEnd; ++Inits) {
1795    CXXBaseOrMemberInitializer *Init = *Inits;
1796
1797    ASTOwningVector<&ActionBase::DeleteExpr> NewArgs(*this);
1798
1799    // Instantiate all the arguments.
1800    for (ExprIterator Args = Init->arg_begin(), ArgsEnd = Init->arg_end();
1801         Args != ArgsEnd; ++Args) {
1802      OwningExprResult NewArg = SubstExpr(*Args, TemplateArgs);
1803
1804      if (NewArg.isInvalid())
1805        New->setInvalidDecl();
1806      else
1807        NewArgs.push_back(NewArg.takeAs<Expr>());
1808    }
1809
1810    MemInitResult NewInit;
1811
1812    if (Init->isBaseInitializer()) {
1813      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
1814                                            TemplateArgs,
1815                                            Init->getSourceLocation(),
1816                                            New->getDeclName());
1817      if (!BaseTInfo) {
1818        New->setInvalidDecl();
1819        continue;
1820      }
1821
1822      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
1823                                     (Expr **)NewArgs.data(),
1824                                     NewArgs.size(),
1825                                     Init->getLParenLoc(),
1826                                     Init->getRParenLoc(),
1827                                     New->getParent());
1828    } else if (Init->isMemberInitializer()) {
1829      FieldDecl *Member;
1830
1831      // Is this an anonymous union?
1832      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
1833        Member = cast<FieldDecl>(FindInstantiatedDecl(UnionInit, TemplateArgs));
1834      else
1835        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMember(),
1836                                                      TemplateArgs));
1837
1838      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
1839                                       NewArgs.size(),
1840                                       Init->getSourceLocation(),
1841                                       Init->getLParenLoc(),
1842                                       Init->getRParenLoc());
1843    }
1844
1845    if (NewInit.isInvalid())
1846      New->setInvalidDecl();
1847    else {
1848      // FIXME: It would be nice if ASTOwningVector had a release function.
1849      NewArgs.take();
1850
1851      NewInits.push_back((MemInitTy *)NewInit.get());
1852    }
1853  }
1854
1855  // Assign all the initializers to the new constructor.
1856  ActOnMemInitializers(DeclPtrTy::make(New),
1857                       /*FIXME: ColonLoc */
1858                       SourceLocation(),
1859                       NewInits.data(), NewInits.size());
1860}
1861
1862// TODO: this could be templated if the various decl types used the
1863// same method name.
1864static bool isInstantiationOf(ClassTemplateDecl *Pattern,
1865                              ClassTemplateDecl *Instance) {
1866  Pattern = Pattern->getCanonicalDecl();
1867
1868  do {
1869    Instance = Instance->getCanonicalDecl();
1870    if (Pattern == Instance) return true;
1871    Instance = Instance->getInstantiatedFromMemberTemplate();
1872  } while (Instance);
1873
1874  return false;
1875}
1876
1877static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
1878                              FunctionTemplateDecl *Instance) {
1879  Pattern = Pattern->getCanonicalDecl();
1880
1881  do {
1882    Instance = Instance->getCanonicalDecl();
1883    if (Pattern == Instance) return true;
1884    Instance = Instance->getInstantiatedFromMemberTemplate();
1885  } while (Instance);
1886
1887  return false;
1888}
1889
1890static bool
1891isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
1892                  ClassTemplatePartialSpecializationDecl *Instance) {
1893  Pattern
1894    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
1895  do {
1896    Instance = cast<ClassTemplatePartialSpecializationDecl>(
1897                                                Instance->getCanonicalDecl());
1898    if (Pattern == Instance)
1899      return true;
1900    Instance = Instance->getInstantiatedFromMember();
1901  } while (Instance);
1902
1903  return false;
1904}
1905
1906static bool isInstantiationOf(CXXRecordDecl *Pattern,
1907                              CXXRecordDecl *Instance) {
1908  Pattern = Pattern->getCanonicalDecl();
1909
1910  do {
1911    Instance = Instance->getCanonicalDecl();
1912    if (Pattern == Instance) return true;
1913    Instance = Instance->getInstantiatedFromMemberClass();
1914  } while (Instance);
1915
1916  return false;
1917}
1918
1919static bool isInstantiationOf(FunctionDecl *Pattern,
1920                              FunctionDecl *Instance) {
1921  Pattern = Pattern->getCanonicalDecl();
1922
1923  do {
1924    Instance = Instance->getCanonicalDecl();
1925    if (Pattern == Instance) return true;
1926    Instance = Instance->getInstantiatedFromMemberFunction();
1927  } while (Instance);
1928
1929  return false;
1930}
1931
1932static bool isInstantiationOf(EnumDecl *Pattern,
1933                              EnumDecl *Instance) {
1934  Pattern = Pattern->getCanonicalDecl();
1935
1936  do {
1937    Instance = Instance->getCanonicalDecl();
1938    if (Pattern == Instance) return true;
1939    Instance = Instance->getInstantiatedFromMemberEnum();
1940  } while (Instance);
1941
1942  return false;
1943}
1944
1945static bool isInstantiationOf(UsingShadowDecl *Pattern,
1946                              UsingShadowDecl *Instance,
1947                              ASTContext &C) {
1948  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
1949}
1950
1951static bool isInstantiationOf(UsingDecl *Pattern,
1952                              UsingDecl *Instance,
1953                              ASTContext &C) {
1954  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
1955}
1956
1957static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
1958                              UsingDecl *Instance,
1959                              ASTContext &C) {
1960  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
1961}
1962
1963static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
1964                              UsingDecl *Instance,
1965                              ASTContext &C) {
1966  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
1967}
1968
1969static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
1970                                              VarDecl *Instance) {
1971  assert(Instance->isStaticDataMember());
1972
1973  Pattern = Pattern->getCanonicalDecl();
1974
1975  do {
1976    Instance = Instance->getCanonicalDecl();
1977    if (Pattern == Instance) return true;
1978    Instance = Instance->getInstantiatedFromStaticDataMember();
1979  } while (Instance);
1980
1981  return false;
1982}
1983
1984// Other is the prospective instantiation
1985// D is the prospective pattern
1986static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
1987  if (D->getKind() != Other->getKind()) {
1988    if (UnresolvedUsingTypenameDecl *UUD
1989          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
1990      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
1991        return isInstantiationOf(UUD, UD, Ctx);
1992      }
1993    }
1994
1995    if (UnresolvedUsingValueDecl *UUD
1996          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
1997      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
1998        return isInstantiationOf(UUD, UD, Ctx);
1999      }
2000    }
2001
2002    return false;
2003  }
2004
2005  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2006    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2007
2008  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2009    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2010
2011  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2012    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2013
2014  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2015    if (Var->isStaticDataMember())
2016      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2017
2018  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2019    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2020
2021  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2022    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2023
2024  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2025        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2026    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2027                             PartialSpec);
2028
2029  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2030    if (!Field->getDeclName()) {
2031      // This is an unnamed field.
2032      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2033        cast<FieldDecl>(D);
2034    }
2035  }
2036
2037  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2038    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2039
2040  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2041    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2042
2043  return D->getDeclName() && isa<NamedDecl>(Other) &&
2044    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2045}
2046
2047template<typename ForwardIterator>
2048static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2049                                      NamedDecl *D,
2050                                      ForwardIterator first,
2051                                      ForwardIterator last) {
2052  for (; first != last; ++first)
2053    if (isInstantiationOf(Ctx, D, *first))
2054      return cast<NamedDecl>(*first);
2055
2056  return 0;
2057}
2058
2059/// \brief Finds the instantiation of the given declaration context
2060/// within the current instantiation.
2061///
2062/// \returns NULL if there was an error
2063DeclContext *Sema::FindInstantiatedContext(DeclContext* DC,
2064                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2065  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2066    Decl* ID = FindInstantiatedDecl(D, TemplateArgs);
2067    return cast_or_null<DeclContext>(ID);
2068  } else return DC;
2069}
2070
2071/// \brief Find the instantiation of the given declaration within the
2072/// current instantiation.
2073///
2074/// This routine is intended to be used when \p D is a declaration
2075/// referenced from within a template, that needs to mapped into the
2076/// corresponding declaration within an instantiation. For example,
2077/// given:
2078///
2079/// \code
2080/// template<typename T>
2081/// struct X {
2082///   enum Kind {
2083///     KnownValue = sizeof(T)
2084///   };
2085///
2086///   bool getKind() const { return KnownValue; }
2087/// };
2088///
2089/// template struct X<int>;
2090/// \endcode
2091///
2092/// In the instantiation of X<int>::getKind(), we need to map the
2093/// EnumConstantDecl for KnownValue (which refers to
2094/// X<T>::<Kind>::KnownValue) to its instantiation
2095/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2096/// this mapping from within the instantiation of X<int>.
2097NamedDecl *Sema::FindInstantiatedDecl(NamedDecl *D,
2098                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2099  DeclContext *ParentDC = D->getDeclContext();
2100  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2101      isa<TemplateTypeParmDecl>(D) || isa<TemplateTypeParmDecl>(D) ||
2102      ParentDC->isFunctionOrMethod()) {
2103    // D is a local of some kind. Look into the map of local
2104    // declarations to their instantiations.
2105    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2106  }
2107
2108  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2109    if (!Record->isDependentContext())
2110      return D;
2111
2112    // If the RecordDecl is actually the injected-class-name or a "templated"
2113    // declaration for a class template or class template partial
2114    // specialization, substitute into the injected-class-name of the
2115    // class template or partial specialization to find the new DeclContext.
2116    QualType T;
2117    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2118
2119    if (ClassTemplate) {
2120      T = ClassTemplate->getInjectedClassNameType(Context);
2121    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2122                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2123      T = Context.getTypeDeclType(Record);
2124      ClassTemplate = PartialSpec->getSpecializedTemplate();
2125    }
2126
2127    if (!T.isNull()) {
2128      // Substitute into the injected-class-name to get the type corresponding
2129      // to the instantiation we want. This substitution should never fail,
2130      // since we know we can instantiate the injected-class-name or we wouldn't
2131      // have gotten to the injected-class-name!
2132      // FIXME: Can we use the CurrentInstantiationScope to avoid this extra
2133      // instantiation in the common case?
2134      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2135      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2136
2137      if (!T->isDependentType()) {
2138        assert(T->isRecordType() && "Instantiation must produce a record type");
2139        return T->getAs<RecordType>()->getDecl();
2140      }
2141
2142      // We are performing "partial" template instantiation to create the
2143      // member declarations for the members of a class template
2144      // specialization. Therefore, D is actually referring to something in
2145      // the current instantiation. Look through the current context,
2146      // which contains actual instantiations, to find the instantiation of
2147      // the "current instantiation" that D refers to.
2148      for (DeclContext *DC = CurContext; !DC->isFileContext();
2149           DC = DC->getParent()) {
2150        if (ClassTemplateSpecializationDecl *Spec
2151              = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2152          if (isInstantiationOf(ClassTemplate,
2153                                Spec->getSpecializedTemplate()))
2154            return Spec;
2155      }
2156
2157      assert(false &&
2158             "Unable to find declaration for the current instantiation");
2159      return Record;
2160    }
2161
2162    // Fall through to deal with other dependent record types (e.g.,
2163    // anonymous unions in class templates).
2164  }
2165
2166  if (!ParentDC->isDependentContext())
2167    return D;
2168
2169  ParentDC = FindInstantiatedContext(ParentDC, TemplateArgs);
2170  if (!ParentDC)
2171    return 0;
2172
2173  if (ParentDC != D->getDeclContext()) {
2174    // We performed some kind of instantiation in the parent context,
2175    // so now we need to look into the instantiated parent context to
2176    // find the instantiation of the declaration D.
2177    NamedDecl *Result = 0;
2178    if (D->getDeclName()) {
2179      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2180      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2181    } else {
2182      // Since we don't have a name for the entity we're looking for,
2183      // our only option is to walk through all of the declarations to
2184      // find that name. This will occur in a few cases:
2185      //
2186      //   - anonymous struct/union within a template
2187      //   - unnamed class/struct/union/enum within a template
2188      //
2189      // FIXME: Find a better way to find these instantiations!
2190      Result = findInstantiationOf(Context, D,
2191                                   ParentDC->decls_begin(),
2192                                   ParentDC->decls_end());
2193    }
2194
2195    // UsingShadowDecls can instantiate to nothing because of using hiding.
2196    assert((Result || isa<UsingShadowDecl>(D))
2197           && "Unable to find instantiation of declaration!");
2198
2199    D = Result;
2200  }
2201
2202  return D;
2203}
2204
2205/// \brief Performs template instantiation for all implicit template
2206/// instantiations we have seen until this point.
2207void Sema::PerformPendingImplicitInstantiations() {
2208  while (!PendingImplicitInstantiations.empty()) {
2209    PendingImplicitInstantiation Inst = PendingImplicitInstantiations.front();
2210    PendingImplicitInstantiations.pop_front();
2211
2212    // Instantiate function definitions
2213    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2214      PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Function),
2215                                            Function->getLocation(), *this,
2216                                            Context.getSourceManager(),
2217                                           "instantiating function definition");
2218
2219      if (!Function->getBody())
2220        InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true);
2221      continue;
2222    }
2223
2224    // Instantiate static data member definitions.
2225    VarDecl *Var = cast<VarDecl>(Inst.first);
2226    assert(Var->isStaticDataMember() && "Not a static data member?");
2227
2228    PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Var),
2229                                          Var->getLocation(), *this,
2230                                          Context.getSourceManager(),
2231                                          "instantiating static data member "
2232                                          "definition");
2233
2234    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true);
2235  }
2236}
2237