SemaTemplateInstantiateDecl.cpp revision 6206d53f67613958ae1b023aba337ebb46f11a8b 
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/DependentDiagnostic.h"
19#include "clang/AST/Expr.h"
20#include "clang/AST/ExprCXX.h"
21#include "clang/AST/TypeLoc.h"
22#include "clang/Basic/PrettyStackTrace.h"
23#include "clang/Lex/Preprocessor.h"
24
25using namespace clang;
26
27namespace {
28  class TemplateDeclInstantiator
29    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
30    Sema &SemaRef;
31    DeclContext *Owner;
32    const MultiLevelTemplateArgumentList &TemplateArgs;
33
34    void InstantiateAttrs(Decl *Tmpl, Decl *New);
35
36  public:
37    typedef Sema::OwningExprResult OwningExprResult;
38
39    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
40                             const MultiLevelTemplateArgumentList &TemplateArgs)
41      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
42
43    // FIXME: Once we get closer to completion, replace these manually-written
44    // declarations with automatically-generated ones from
45    // clang/AST/DeclNodes.inc.
46    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
47    Decl *VisitNamespaceDecl(NamespaceDecl *D);
48    Decl *VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
49    Decl *VisitTypedefDecl(TypedefDecl *D);
50    Decl *VisitVarDecl(VarDecl *D);
51    Decl *VisitAccessSpecDecl(AccessSpecDecl *D);
52    Decl *VisitFieldDecl(FieldDecl *D);
53    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
54    Decl *VisitEnumDecl(EnumDecl *D);
55    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
56    Decl *VisitFriendDecl(FriendDecl *D);
57    Decl *VisitFunctionDecl(FunctionDecl *D,
58                            TemplateParameterList *TemplateParams = 0);
59    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
60    Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
61                             TemplateParameterList *TemplateParams = 0);
62    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
63    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
64    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
65    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
66    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
67    Decl *VisitClassTemplatePartialSpecializationDecl(
68                                    ClassTemplatePartialSpecializationDecl *D);
69    Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
70    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
71    Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
72    Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
73    Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
74    Decl *VisitUsingDecl(UsingDecl *D);
75    Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
76    Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
77    Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
78
79    // Base case. FIXME: Remove once we can instantiate everything.
80    Decl *VisitDecl(Decl *D) {
81      unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
82                                                            Diagnostic::Error,
83                                                   "cannot instantiate %0 yet");
84      SemaRef.Diag(D->getLocation(), DiagID)
85        << D->getDeclKindName();
86
87      return 0;
88    }
89
90    const LangOptions &getLangOptions() {
91      return SemaRef.getLangOptions();
92    }
93
94    // Helper functions for instantiating methods.
95    TypeSourceInfo *SubstFunctionType(FunctionDecl *D,
96                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
97    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
98    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
99
100    TemplateParameterList *
101      SubstTemplateParams(TemplateParameterList *List);
102
103    bool SubstQualifier(const DeclaratorDecl *OldDecl,
104                        DeclaratorDecl *NewDecl);
105    bool SubstQualifier(const TagDecl *OldDecl,
106                        TagDecl *NewDecl);
107
108    bool InstantiateClassTemplatePartialSpecialization(
109                                              ClassTemplateDecl *ClassTemplate,
110                           ClassTemplatePartialSpecializationDecl *PartialSpec);
111  };
112}
113
114bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
115                                              DeclaratorDecl *NewDecl) {
116  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
117  if (!OldQual) return false;
118
119  SourceRange QualRange = OldDecl->getQualifierRange();
120
121  NestedNameSpecifier *NewQual
122    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
123  if (!NewQual)
124    return true;
125
126  NewDecl->setQualifierInfo(NewQual, QualRange);
127  return false;
128}
129
130bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
131                                              TagDecl *NewDecl) {
132  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
133  if (!OldQual) return false;
134
135  SourceRange QualRange = OldDecl->getQualifierRange();
136
137  NestedNameSpecifier *NewQual
138    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
139  if (!NewQual)
140    return true;
141
142  NewDecl->setQualifierInfo(NewQual, QualRange);
143  return false;
144}
145
146// FIXME: Is this too simple?
147void TemplateDeclInstantiator::InstantiateAttrs(Decl *Tmpl, Decl *New) {
148  for (const Attr *TmplAttr = Tmpl->getAttrs(); TmplAttr;
149       TmplAttr = TmplAttr->getNext()) {
150
151    // FIXME: Is cloning correct for all attributes?
152    Attr *NewAttr = TmplAttr->clone(SemaRef.Context);
153
154    New->addAttr(NewAttr);
155  }
156}
157
158Decl *
159TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
160  assert(false && "Translation units cannot be instantiated");
161  return D;
162}
163
164Decl *
165TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
166  assert(false && "Namespaces cannot be instantiated");
167  return D;
168}
169
170Decl *
171TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
172  NamespaceAliasDecl *Inst
173    = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
174                                 D->getNamespaceLoc(),
175                                 D->getAliasLoc(),
176                                 D->getNamespace()->getIdentifier(),
177                                 D->getQualifierRange(),
178                                 D->getQualifier(),
179                                 D->getTargetNameLoc(),
180                                 D->getNamespace());
181  Owner->addDecl(Inst);
182  return Inst;
183}
184
185Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
186  bool Invalid = false;
187  TypeSourceInfo *DI = D->getTypeSourceInfo();
188  if (DI->getType()->isDependentType() ||
189      DI->getType()->isVariablyModifiedType()) {
190    DI = SemaRef.SubstType(DI, TemplateArgs,
191                           D->getLocation(), D->getDeclName());
192    if (!DI) {
193      Invalid = true;
194      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
195    }
196  } else {
197    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
198  }
199
200  // Create the new typedef
201  TypedefDecl *Typedef
202    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
203                          D->getIdentifier(), DI);
204  if (Invalid)
205    Typedef->setInvalidDecl();
206
207  if (const TagType *TT = DI->getType()->getAs<TagType>()) {
208    TagDecl *TD = TT->getDecl();
209
210    // If the TagDecl that the TypedefDecl points to is an anonymous decl
211    // keep track of the TypedefDecl.
212    if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl())
213      TD->setTypedefForAnonDecl(Typedef);
214  }
215
216  if (TypedefDecl *Prev = D->getPreviousDeclaration()) {
217    NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
218                                                       TemplateArgs);
219    Typedef->setPreviousDeclaration(cast<TypedefDecl>(InstPrev));
220  }
221
222  InstantiateAttrs(D, Typedef);
223
224  Typedef->setAccess(D->getAccess());
225  Owner->addDecl(Typedef);
226
227  return Typedef;
228}
229
230/// \brief Instantiate the arguments provided as part of initialization.
231///
232/// \returns true if an error occurred, false otherwise.
233static bool InstantiateInitializationArguments(Sema &SemaRef,
234                                               Expr **Args, unsigned NumArgs,
235                           const MultiLevelTemplateArgumentList &TemplateArgs,
236                         llvm::SmallVectorImpl<SourceLocation> &FakeCommaLocs,
237                           ASTOwningVector<&ActionBase::DeleteExpr> &InitArgs) {
238  for (unsigned I = 0; I != NumArgs; ++I) {
239    // When we hit the first defaulted argument, break out of the loop:
240    // we don't pass those default arguments on.
241    if (Args[I]->isDefaultArgument())
242      break;
243
244    Sema::OwningExprResult Arg = SemaRef.SubstExpr(Args[I], TemplateArgs);
245    if (Arg.isInvalid())
246      return true;
247
248    Expr *ArgExpr = (Expr *)Arg.get();
249    InitArgs.push_back(Arg.release());
250
251    // FIXME: We're faking all of the comma locations. Do we need them?
252    FakeCommaLocs.push_back(
253                          SemaRef.PP.getLocForEndOfToken(ArgExpr->getLocEnd()));
254  }
255
256  return false;
257}
258
259/// \brief Instantiate an initializer, breaking it into separate
260/// initialization arguments.
261///
262/// \param S The semantic analysis object.
263///
264/// \param Init The initializer to instantiate.
265///
266/// \param TemplateArgs Template arguments to be substituted into the
267/// initializer.
268///
269/// \param NewArgs Will be filled in with the instantiation arguments.
270///
271/// \returns true if an error occurred, false otherwise
272static bool InstantiateInitializer(Sema &S, Expr *Init,
273                            const MultiLevelTemplateArgumentList &TemplateArgs,
274                                   SourceLocation &LParenLoc,
275                               llvm::SmallVector<SourceLocation, 4> &CommaLocs,
276                             ASTOwningVector<&ActionBase::DeleteExpr> &NewArgs,
277                                   SourceLocation &RParenLoc) {
278  NewArgs.clear();
279  LParenLoc = SourceLocation();
280  RParenLoc = SourceLocation();
281
282  if (!Init)
283    return false;
284
285  if (CXXExprWithTemporaries *ExprTemp = dyn_cast<CXXExprWithTemporaries>(Init))
286    Init = ExprTemp->getSubExpr();
287
288  while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init))
289    Init = Binder->getSubExpr();
290
291  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
292    Init = ICE->getSubExprAsWritten();
293
294  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
295    LParenLoc = ParenList->getLParenLoc();
296    RParenLoc = ParenList->getRParenLoc();
297    return InstantiateInitializationArguments(S, ParenList->getExprs(),
298                                              ParenList->getNumExprs(),
299                                              TemplateArgs, CommaLocs,
300                                              NewArgs);
301  }
302
303  if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) {
304    if (!isa<CXXTemporaryObjectExpr>(Construct)) {
305      if (InstantiateInitializationArguments(S,
306                                             Construct->getArgs(),
307                                             Construct->getNumArgs(),
308                                             TemplateArgs,
309                                             CommaLocs, NewArgs))
310        return true;
311
312      // FIXME: Fake locations!
313      LParenLoc = S.PP.getLocForEndOfToken(Init->getLocStart());
314      RParenLoc = CommaLocs.empty()? LParenLoc : CommaLocs.back();
315      return false;
316    }
317  }
318
319  Sema::OwningExprResult Result = S.SubstExpr(Init, TemplateArgs);
320  if (Result.isInvalid())
321    return true;
322
323  NewArgs.push_back(Result.takeAs<Expr>());
324  return false;
325}
326
327Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
328  // If this is the variable for an anonymous struct or union,
329  // instantiate the anonymous struct/union type first.
330  if (const RecordType *RecordTy = D->getType()->getAs<RecordType>())
331    if (RecordTy->getDecl()->isAnonymousStructOrUnion())
332      if (!VisitCXXRecordDecl(cast<CXXRecordDecl>(RecordTy->getDecl())))
333        return 0;
334
335  // Do substitution on the type of the declaration
336  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
337                                         TemplateArgs,
338                                         D->getTypeSpecStartLoc(),
339                                         D->getDeclName());
340  if (!DI)
341    return 0;
342
343  // Build the instantiated declaration
344  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
345                                 D->getLocation(), D->getIdentifier(),
346                                 DI->getType(), DI,
347                                 D->getStorageClass(),
348                                 D->getStorageClassAsWritten());
349  Var->setThreadSpecified(D->isThreadSpecified());
350  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
351  Var->setDeclaredInCondition(D->isDeclaredInCondition());
352
353  // Substitute the nested name specifier, if any.
354  if (SubstQualifier(D, Var))
355    return 0;
356
357  // If we are instantiating a static data member defined
358  // out-of-line, the instantiation will have the same lexical
359  // context (which will be a namespace scope) as the template.
360  if (D->isOutOfLine())
361    Var->setLexicalDeclContext(D->getLexicalDeclContext());
362
363  Var->setAccess(D->getAccess());
364  Var->setUsed(D->isUsed());
365
366  // FIXME: In theory, we could have a previous declaration for variables that
367  // are not static data members.
368  bool Redeclaration = false;
369  // FIXME: having to fake up a LookupResult is dumb.
370  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
371                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
372  if (D->isStaticDataMember())
373    SemaRef.LookupQualifiedName(Previous, Owner, false);
374  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
375
376  if (D->isOutOfLine()) {
377    if (!D->isStaticDataMember())
378      D->getLexicalDeclContext()->addDecl(Var);
379    Owner->makeDeclVisibleInContext(Var);
380  } else {
381    Owner->addDecl(Var);
382
383    if (Owner->isFunctionOrMethod())
384      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Var);
385  }
386
387  // Link instantiations of static data members back to the template from
388  // which they were instantiated.
389  if (Var->isStaticDataMember())
390    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
391                                                     TSK_ImplicitInstantiation);
392
393  if (Var->getAnyInitializer()) {
394    // We already have an initializer in the class.
395  } else if (D->getInit()) {
396    if (Var->isStaticDataMember() && !D->isOutOfLine())
397      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
398    else
399      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
400
401    // Instantiate the initializer.
402    SourceLocation LParenLoc, RParenLoc;
403    llvm::SmallVector<SourceLocation, 4> CommaLocs;
404    ASTOwningVector<&ActionBase::DeleteExpr> InitArgs(SemaRef);
405    if (!InstantiateInitializer(SemaRef, D->getInit(), TemplateArgs, LParenLoc,
406                                CommaLocs, InitArgs, RParenLoc)) {
407      // Attach the initializer to the declaration.
408      if (D->hasCXXDirectInitializer()) {
409        // Add the direct initializer to the declaration.
410        SemaRef.AddCXXDirectInitializerToDecl(Sema::DeclPtrTy::make(Var),
411                                              LParenLoc,
412                                              move_arg(InitArgs),
413                                              CommaLocs.data(),
414                                              RParenLoc);
415      } else if (InitArgs.size() == 1) {
416        Expr *Init = (Expr*)(InitArgs.take()[0]);
417        SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var),
418                                     SemaRef.Owned(Init),
419                                     false);
420      } else {
421        assert(InitArgs.size() == 0);
422        SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
423      }
424    } else {
425      // FIXME: Not too happy about invalidating the declaration
426      // because of a bogus initializer.
427      Var->setInvalidDecl();
428    }
429
430    SemaRef.PopExpressionEvaluationContext();
431  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
432    SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
433
434  // Diagnose unused local variables.
435  if (!Var->isInvalidDecl() && Owner->isFunctionOrMethod() && !Var->isUsed())
436    SemaRef.DiagnoseUnusedDecl(Var);
437
438  return Var;
439}
440
441Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
442  AccessSpecDecl* AD
443    = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
444                             D->getAccessSpecifierLoc(), D->getColonLoc());
445  Owner->addHiddenDecl(AD);
446  return AD;
447}
448
449Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
450  bool Invalid = false;
451  TypeSourceInfo *DI = D->getTypeSourceInfo();
452  if (DI->getType()->isDependentType() ||
453      DI->getType()->isVariablyModifiedType())  {
454    DI = SemaRef.SubstType(DI, TemplateArgs,
455                           D->getLocation(), D->getDeclName());
456    if (!DI) {
457      DI = D->getTypeSourceInfo();
458      Invalid = true;
459    } else if (DI->getType()->isFunctionType()) {
460      // C++ [temp.arg.type]p3:
461      //   If a declaration acquires a function type through a type
462      //   dependent on a template-parameter and this causes a
463      //   declaration that does not use the syntactic form of a
464      //   function declarator to have function type, the program is
465      //   ill-formed.
466      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
467        << DI->getType();
468      Invalid = true;
469    }
470  } else {
471    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
472  }
473
474  Expr *BitWidth = D->getBitWidth();
475  if (Invalid)
476    BitWidth = 0;
477  else if (BitWidth) {
478    // The bit-width expression is not potentially evaluated.
479    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
480
481    OwningExprResult InstantiatedBitWidth
482      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
483    if (InstantiatedBitWidth.isInvalid()) {
484      Invalid = true;
485      BitWidth = 0;
486    } else
487      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
488  }
489
490  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
491                                            DI->getType(), DI,
492                                            cast<RecordDecl>(Owner),
493                                            D->getLocation(),
494                                            D->isMutable(),
495                                            BitWidth,
496                                            D->getTypeSpecStartLoc(),
497                                            D->getAccess(),
498                                            0);
499  if (!Field) {
500    cast<Decl>(Owner)->setInvalidDecl();
501    return 0;
502  }
503
504  InstantiateAttrs(D, Field);
505
506  if (Invalid)
507    Field->setInvalidDecl();
508
509  if (!Field->getDeclName()) {
510    // Keep track of where this decl came from.
511    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
512  }
513  if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
514    if (Parent->isAnonymousStructOrUnion() &&
515        Parent->getLookupContext()->isFunctionOrMethod())
516      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
517  }
518
519  Field->setImplicit(D->isImplicit());
520  Field->setAccess(D->getAccess());
521  Owner->addDecl(Field);
522
523  return Field;
524}
525
526Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
527  // Handle friend type expressions by simply substituting template
528  // parameters into the pattern type and checking the result.
529  if (TypeSourceInfo *Ty = D->getFriendType()) {
530    TypeSourceInfo *InstTy =
531      SemaRef.SubstType(Ty, TemplateArgs,
532                        D->getLocation(), DeclarationName());
533    if (!InstTy)
534      return 0;
535
536    FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getFriendLoc(), InstTy);
537    if (!FD)
538      return 0;
539
540    FD->setAccess(AS_public);
541    Owner->addDecl(FD);
542    return FD;
543  }
544
545  NamedDecl *ND = D->getFriendDecl();
546  assert(ND && "friend decl must be a decl or a type!");
547
548  // All of the Visit implementations for the various potential friend
549  // declarations have to be carefully written to work for friend
550  // objects, with the most important detail being that the target
551  // decl should almost certainly not be placed in Owner.
552  Decl *NewND = Visit(ND);
553  if (!NewND) return 0;
554
555  FriendDecl *FD =
556    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
557                       cast<NamedDecl>(NewND), D->getFriendLoc());
558  FD->setAccess(AS_public);
559  Owner->addDecl(FD);
560  return FD;
561}
562
563Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
564  Expr *AssertExpr = D->getAssertExpr();
565
566  // The expression in a static assertion is not potentially evaluated.
567  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
568
569  OwningExprResult InstantiatedAssertExpr
570    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
571  if (InstantiatedAssertExpr.isInvalid())
572    return 0;
573
574  OwningExprResult Message(SemaRef, D->getMessage());
575  D->getMessage()->Retain();
576  Decl *StaticAssert
577    = SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
578                                           move(InstantiatedAssertExpr),
579                                           move(Message)).getAs<Decl>();
580  return StaticAssert;
581}
582
583Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
584  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
585                                    D->getLocation(), D->getIdentifier(),
586                                    D->getTagKeywordLoc(),
587                                    /*PrevDecl=*/0);
588  Enum->setInstantiationOfMemberEnum(D);
589  Enum->setAccess(D->getAccess());
590  if (SubstQualifier(D, Enum)) return 0;
591  Owner->addDecl(Enum);
592  Enum->startDefinition();
593
594  if (D->getDeclContext()->isFunctionOrMethod())
595    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
596
597  llvm::SmallVector<Sema::DeclPtrTy, 4> Enumerators;
598
599  EnumConstantDecl *LastEnumConst = 0;
600  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
601         ECEnd = D->enumerator_end();
602       EC != ECEnd; ++EC) {
603    // The specified value for the enumerator.
604    OwningExprResult Value = SemaRef.Owned((Expr *)0);
605    if (Expr *UninstValue = EC->getInitExpr()) {
606      // The enumerator's value expression is not potentially evaluated.
607      EnterExpressionEvaluationContext Unevaluated(SemaRef,
608                                                   Action::Unevaluated);
609
610      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
611    }
612
613    // Drop the initial value and continue.
614    bool isInvalid = false;
615    if (Value.isInvalid()) {
616      Value = SemaRef.Owned((Expr *)0);
617      isInvalid = true;
618    }
619
620    EnumConstantDecl *EnumConst
621      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
622                                  EC->getLocation(), EC->getIdentifier(),
623                                  move(Value));
624
625    if (isInvalid) {
626      if (EnumConst)
627        EnumConst->setInvalidDecl();
628      Enum->setInvalidDecl();
629    }
630
631    if (EnumConst) {
632      EnumConst->setAccess(Enum->getAccess());
633      Enum->addDecl(EnumConst);
634      Enumerators.push_back(Sema::DeclPtrTy::make(EnumConst));
635      LastEnumConst = EnumConst;
636
637      if (D->getDeclContext()->isFunctionOrMethod()) {
638        // If the enumeration is within a function or method, record the enum
639        // constant as a local.
640        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
641      }
642    }
643  }
644
645  // FIXME: Fixup LBraceLoc and RBraceLoc
646  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
647  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
648                        Sema::DeclPtrTy::make(Enum),
649                        &Enumerators[0], Enumerators.size(),
650                        0, 0);
651
652  return Enum;
653}
654
655Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
656  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
657  return 0;
658}
659
660Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
661  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
662
663  // Create a local instantiation scope for this class template, which
664  // will contain the instantiations of the template parameters.
665  Sema::LocalInstantiationScope Scope(SemaRef);
666  TemplateParameterList *TempParams = D->getTemplateParameters();
667  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
668  if (!InstParams)
669    return NULL;
670
671  CXXRecordDecl *Pattern = D->getTemplatedDecl();
672
673  // Instantiate the qualifier.  We have to do this first in case
674  // we're a friend declaration, because if we are then we need to put
675  // the new declaration in the appropriate context.
676  NestedNameSpecifier *Qualifier = Pattern->getQualifier();
677  if (Qualifier) {
678    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
679                                                 Pattern->getQualifierRange(),
680                                                 TemplateArgs);
681    if (!Qualifier) return 0;
682  }
683
684  CXXRecordDecl *PrevDecl = 0;
685  ClassTemplateDecl *PrevClassTemplate = 0;
686
687  // If this isn't a friend, then it's a member template, in which
688  // case we just want to build the instantiation in the
689  // specialization.  If it is a friend, we want to build it in
690  // the appropriate context.
691  DeclContext *DC = Owner;
692  if (isFriend) {
693    if (Qualifier) {
694      CXXScopeSpec SS;
695      SS.setScopeRep(Qualifier);
696      SS.setRange(Pattern->getQualifierRange());
697      DC = SemaRef.computeDeclContext(SS);
698      if (!DC) return 0;
699    } else {
700      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
701                                           Pattern->getDeclContext(),
702                                           TemplateArgs);
703    }
704
705    // Look for a previous declaration of the template in the owning
706    // context.
707    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
708                   Sema::LookupOrdinaryName, Sema::ForRedeclaration);
709    SemaRef.LookupQualifiedName(R, DC);
710
711    if (R.isSingleResult()) {
712      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
713      if (PrevClassTemplate)
714        PrevDecl = PrevClassTemplate->getTemplatedDecl();
715    }
716
717    if (!PrevClassTemplate && Qualifier) {
718      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
719        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
720        << Pattern->getQualifierRange();
721      return 0;
722    }
723
724    bool AdoptedPreviousTemplateParams = false;
725    if (PrevClassTemplate) {
726      bool Complain = true;
727
728      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
729      // template for struct std::tr1::__detail::_Map_base, where the
730      // template parameters of the friend declaration don't match the
731      // template parameters of the original declaration. In this one
732      // case, we don't complain about the ill-formed friend
733      // declaration.
734      if (isFriend && Pattern->getIdentifier() &&
735          Pattern->getIdentifier()->isStr("_Map_base") &&
736          DC->isNamespace() &&
737          cast<NamespaceDecl>(DC)->getIdentifier() &&
738          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
739        DeclContext *DCParent = DC->getParent();
740        if (DCParent->isNamespace() &&
741            cast<NamespaceDecl>(DCParent)->getIdentifier() &&
742            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
743          DeclContext *DCParent2 = DCParent->getParent();
744          if (DCParent2->isNamespace() &&
745              cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
746              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
747              DCParent2->getParent()->isTranslationUnit())
748            Complain = false;
749        }
750      }
751
752      TemplateParameterList *PrevParams
753        = PrevClassTemplate->getTemplateParameters();
754
755      // Make sure the parameter lists match.
756      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
757                                                  Complain,
758                                                  Sema::TPL_TemplateMatch)) {
759        if (Complain)
760          return 0;
761
762        AdoptedPreviousTemplateParams = true;
763        InstParams = PrevParams;
764      }
765
766      // Do some additional validation, then merge default arguments
767      // from the existing declarations.
768      if (!AdoptedPreviousTemplateParams &&
769          SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
770                                             Sema::TPC_ClassTemplate))
771        return 0;
772    }
773  }
774
775  CXXRecordDecl *RecordInst
776    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
777                            Pattern->getLocation(), Pattern->getIdentifier(),
778                            Pattern->getTagKeywordLoc(), PrevDecl,
779                            /*DelayTypeCreation=*/true);
780
781  if (Qualifier)
782    RecordInst->setQualifierInfo(Qualifier, Pattern->getQualifierRange());
783
784  ClassTemplateDecl *Inst
785    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
786                                D->getIdentifier(), InstParams, RecordInst,
787                                PrevClassTemplate);
788  RecordInst->setDescribedClassTemplate(Inst);
789
790  if (isFriend) {
791    if (PrevClassTemplate)
792      Inst->setAccess(PrevClassTemplate->getAccess());
793    else
794      Inst->setAccess(D->getAccess());
795
796    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
797    // TODO: do we want to track the instantiation progeny of this
798    // friend target decl?
799  } else {
800    Inst->setAccess(D->getAccess());
801    Inst->setInstantiatedFromMemberTemplate(D);
802  }
803
804  // Trigger creation of the type for the instantiation.
805  SemaRef.Context.getInjectedClassNameType(RecordInst,
806                  Inst->getInjectedClassNameSpecialization(SemaRef.Context));
807
808  // Finish handling of friends.
809  if (isFriend) {
810    DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
811    return Inst;
812  }
813
814  Owner->addDecl(Inst);
815
816  // Instantiate all of the partial specializations of this member class
817  // template.
818  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
819  D->getPartialSpecializations(PartialSpecs);
820  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
821    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
822
823  return Inst;
824}
825
826Decl *
827TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
828                                   ClassTemplatePartialSpecializationDecl *D) {
829  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
830
831  // Lookup the already-instantiated declaration in the instantiation
832  // of the class template and return that.
833  DeclContext::lookup_result Found
834    = Owner->lookup(ClassTemplate->getDeclName());
835  if (Found.first == Found.second)
836    return 0;
837
838  ClassTemplateDecl *InstClassTemplate
839    = dyn_cast<ClassTemplateDecl>(*Found.first);
840  if (!InstClassTemplate)
841    return 0;
842
843  Decl *DCanon = D->getCanonicalDecl();
844  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
845            P = InstClassTemplate->getPartialSpecializations().begin(),
846         PEnd = InstClassTemplate->getPartialSpecializations().end();
847       P != PEnd; ++P) {
848    if (P->getInstantiatedFromMember()->getCanonicalDecl() == DCanon)
849      return &*P;
850  }
851
852  return 0;
853}
854
855Decl *
856TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
857  // Create a local instantiation scope for this function template, which
858  // will contain the instantiations of the template parameters and then get
859  // merged with the local instantiation scope for the function template
860  // itself.
861  Sema::LocalInstantiationScope Scope(SemaRef);
862
863  TemplateParameterList *TempParams = D->getTemplateParameters();
864  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
865  if (!InstParams)
866    return NULL;
867
868  FunctionDecl *Instantiated = 0;
869  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
870    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
871                                                                 InstParams));
872  else
873    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
874                                                          D->getTemplatedDecl(),
875                                                                InstParams));
876
877  if (!Instantiated)
878    return 0;
879
880  Instantiated->setAccess(D->getAccess());
881
882  // Link the instantiated function template declaration to the function
883  // template from which it was instantiated.
884  FunctionTemplateDecl *InstTemplate
885    = Instantiated->getDescribedFunctionTemplate();
886  InstTemplate->setAccess(D->getAccess());
887  assert(InstTemplate &&
888         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
889
890  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
891
892  // Link the instantiation back to the pattern *unless* this is a
893  // non-definition friend declaration.
894  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
895      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
896    InstTemplate->setInstantiatedFromMemberTemplate(D);
897
898  // Make declarations visible in the appropriate context.
899  if (!isFriend)
900    Owner->addDecl(InstTemplate);
901
902  return InstTemplate;
903}
904
905Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
906  CXXRecordDecl *PrevDecl = 0;
907  if (D->isInjectedClassName())
908    PrevDecl = cast<CXXRecordDecl>(Owner);
909  else if (D->getPreviousDeclaration()) {
910    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
911                                                   D->getPreviousDeclaration(),
912                                                   TemplateArgs);
913    if (!Prev) return 0;
914    PrevDecl = cast<CXXRecordDecl>(Prev);
915  }
916
917  CXXRecordDecl *Record
918    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
919                            D->getLocation(), D->getIdentifier(),
920                            D->getTagKeywordLoc(), PrevDecl);
921
922  // Substitute the nested name specifier, if any.
923  if (SubstQualifier(D, Record))
924    return 0;
925
926  Record->setImplicit(D->isImplicit());
927  // FIXME: Check against AS_none is an ugly hack to work around the issue that
928  // the tag decls introduced by friend class declarations don't have an access
929  // specifier. Remove once this area of the code gets sorted out.
930  if (D->getAccess() != AS_none)
931    Record->setAccess(D->getAccess());
932  if (!D->isInjectedClassName())
933    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
934
935  // If the original function was part of a friend declaration,
936  // inherit its namespace state.
937  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
938    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
939
940  // Make sure that anonymous structs and unions are recorded.
941  if (D->isAnonymousStructOrUnion()) {
942    Record->setAnonymousStructOrUnion(true);
943    if (Record->getDeclContext()->getLookupContext()->isFunctionOrMethod())
944      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
945  }
946
947  Owner->addDecl(Record);
948  return Record;
949}
950
951/// Normal class members are of more specific types and therefore
952/// don't make it here.  This function serves two purposes:
953///   1) instantiating function templates
954///   2) substituting friend declarations
955/// FIXME: preserve function definitions in case #2
956Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
957                                       TemplateParameterList *TemplateParams) {
958  // Check whether there is already a function template specialization for
959  // this declaration.
960  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
961  void *InsertPos = 0;
962  if (FunctionTemplate && !TemplateParams) {
963    llvm::FoldingSetNodeID ID;
964    FunctionTemplateSpecializationInfo::Profile(ID,
965                             TemplateArgs.getInnermost().getFlatArgumentList(),
966                                       TemplateArgs.getInnermost().flat_size(),
967                                                SemaRef.Context);
968
969    FunctionTemplateSpecializationInfo *Info
970      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
971                                                                   InsertPos);
972
973    // If we already have a function template specialization, return it.
974    if (Info)
975      return Info->Function;
976  }
977
978  bool isFriend;
979  if (FunctionTemplate)
980    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
981  else
982    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
983
984  bool MergeWithParentScope = (TemplateParams != 0) ||
985    Owner->isFunctionOrMethod() ||
986    !(isa<Decl>(Owner) &&
987      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
988  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
989
990  llvm::SmallVector<ParmVarDecl *, 4> Params;
991  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
992  TInfo = SubstFunctionType(D, Params);
993  if (!TInfo)
994    return 0;
995  QualType T = TInfo->getType();
996
997  NestedNameSpecifier *Qualifier = D->getQualifier();
998  if (Qualifier) {
999    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1000                                                 D->getQualifierRange(),
1001                                                 TemplateArgs);
1002    if (!Qualifier) return 0;
1003  }
1004
1005  // If we're instantiating a local function declaration, put the result
1006  // in the owner;  otherwise we need to find the instantiated context.
1007  DeclContext *DC;
1008  if (D->getDeclContext()->isFunctionOrMethod())
1009    DC = Owner;
1010  else if (isFriend && Qualifier) {
1011    CXXScopeSpec SS;
1012    SS.setScopeRep(Qualifier);
1013    SS.setRange(D->getQualifierRange());
1014    DC = SemaRef.computeDeclContext(SS);
1015    if (!DC) return 0;
1016  } else {
1017    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1018                                         TemplateArgs);
1019  }
1020
1021  FunctionDecl *Function =
1022      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
1023                           D->getDeclName(), T, TInfo,
1024                           D->getStorageClass(), D->getStorageClassAsWritten(),
1025                           D->isInlineSpecified(), D->hasWrittenPrototype());
1026
1027  if (Qualifier)
1028    Function->setQualifierInfo(Qualifier, D->getQualifierRange());
1029
1030  DeclContext *LexicalDC = Owner;
1031  if (!isFriend && D->isOutOfLine()) {
1032    assert(D->getDeclContext()->isFileContext());
1033    LexicalDC = D->getDeclContext();
1034  }
1035
1036  Function->setLexicalDeclContext(LexicalDC);
1037
1038  // Attach the parameters
1039  for (unsigned P = 0; P < Params.size(); ++P)
1040    Params[P]->setOwningFunction(Function);
1041  Function->setParams(Params.data(), Params.size());
1042
1043  SourceLocation InstantiateAtPOI;
1044  if (TemplateParams) {
1045    // Our resulting instantiation is actually a function template, since we
1046    // are substituting only the outer template parameters. For example, given
1047    //
1048    //   template<typename T>
1049    //   struct X {
1050    //     template<typename U> friend void f(T, U);
1051    //   };
1052    //
1053    //   X<int> x;
1054    //
1055    // We are instantiating the friend function template "f" within X<int>,
1056    // which means substituting int for T, but leaving "f" as a friend function
1057    // template.
1058    // Build the function template itself.
1059    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1060                                                    Function->getLocation(),
1061                                                    Function->getDeclName(),
1062                                                    TemplateParams, Function);
1063    Function->setDescribedFunctionTemplate(FunctionTemplate);
1064
1065    FunctionTemplate->setLexicalDeclContext(LexicalDC);
1066
1067    if (isFriend && D->isThisDeclarationADefinition()) {
1068      // TODO: should we remember this connection regardless of whether
1069      // the friend declaration provided a body?
1070      FunctionTemplate->setInstantiatedFromMemberTemplate(
1071                                           D->getDescribedFunctionTemplate());
1072    }
1073  } else if (FunctionTemplate) {
1074    // Record this function template specialization.
1075    Function->setFunctionTemplateSpecialization(FunctionTemplate,
1076                                                &TemplateArgs.getInnermost(),
1077                                                InsertPos);
1078  } else if (isFriend && D->isThisDeclarationADefinition()) {
1079    // TODO: should we remember this connection regardless of whether
1080    // the friend declaration provided a body?
1081    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1082  }
1083
1084  if (InitFunctionInstantiation(Function, D))
1085    Function->setInvalidDecl();
1086
1087  bool Redeclaration = false;
1088  bool OverloadableAttrRequired = false;
1089  bool isExplicitSpecialization = false;
1090
1091  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1092                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1093
1094  if (DependentFunctionTemplateSpecializationInfo *Info
1095        = D->getDependentSpecializationInfo()) {
1096    assert(isFriend && "non-friend has dependent specialization info?");
1097
1098    // This needs to be set now for future sanity.
1099    Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1100
1101    // Instantiate the explicit template arguments.
1102    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1103                                          Info->getRAngleLoc());
1104    for (unsigned I = 0, E = Info->getNumTemplateArgs(); I != E; ++I) {
1105      TemplateArgumentLoc Loc;
1106      if (SemaRef.Subst(Info->getTemplateArg(I), Loc, TemplateArgs))
1107        return 0;
1108
1109      ExplicitArgs.addArgument(Loc);
1110    }
1111
1112    // Map the candidate templates to their instantiations.
1113    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1114      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1115                                                Info->getTemplate(I),
1116                                                TemplateArgs);
1117      if (!Temp) return 0;
1118
1119      Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1120    }
1121
1122    if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1123                                                    &ExplicitArgs,
1124                                                    Previous))
1125      Function->setInvalidDecl();
1126
1127    isExplicitSpecialization = true;
1128
1129  } else if (TemplateParams || !FunctionTemplate) {
1130    // Look only into the namespace where the friend would be declared to
1131    // find a previous declaration. This is the innermost enclosing namespace,
1132    // as described in ActOnFriendFunctionDecl.
1133    SemaRef.LookupQualifiedName(Previous, DC);
1134
1135    // In C++, the previous declaration we find might be a tag type
1136    // (class or enum). In this case, the new declaration will hide the
1137    // tag type. Note that this does does not apply if we're declaring a
1138    // typedef (C++ [dcl.typedef]p4).
1139    if (Previous.isSingleTagDecl())
1140      Previous.clear();
1141  }
1142
1143  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1144                                   isExplicitSpecialization, Redeclaration,
1145                                   /*FIXME:*/OverloadableAttrRequired);
1146
1147  NamedDecl *PrincipalDecl = (TemplateParams
1148                              ? cast<NamedDecl>(FunctionTemplate)
1149                              : Function);
1150
1151  // If the original function was part of a friend declaration,
1152  // inherit its namespace state and add it to the owner.
1153  if (isFriend) {
1154    NamedDecl *PrevDecl;
1155    if (TemplateParams)
1156      PrevDecl = FunctionTemplate->getPreviousDeclaration();
1157    else
1158      PrevDecl = Function->getPreviousDeclaration();
1159
1160    PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0);
1161    DC->makeDeclVisibleInContext(PrincipalDecl, /*Recoverable=*/ false);
1162
1163    if (!SemaRef.getLangOptions().CPlusPlus0x &&
1164        D->isThisDeclarationADefinition()) {
1165      // Check for a function body.
1166      const FunctionDecl *Definition = 0;
1167      if (Function->getBody(Definition) &&
1168          Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1169        SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1170          << Function->getDeclName();
1171        SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1172        Function->setInvalidDecl();
1173      }
1174      // Check for redefinitions due to other instantiations of this or
1175      // a similar friend function.
1176      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1177                                           REnd = Function->redecls_end();
1178                R != REnd; ++R) {
1179        if (*R != Function &&
1180            ((*R)->getFriendObjectKind() != Decl::FOK_None)) {
1181          if (const FunctionDecl *RPattern
1182              = (*R)->getTemplateInstantiationPattern())
1183            if (RPattern->getBody(RPattern)) {
1184              SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1185                << Function->getDeclName();
1186              SemaRef.Diag((*R)->getLocation(), diag::note_previous_definition);
1187              Function->setInvalidDecl();
1188              break;
1189            }
1190        }
1191      }
1192    }
1193
1194  }
1195
1196  if (Function->isOverloadedOperator() && !DC->isRecord() &&
1197      PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1198    PrincipalDecl->setNonMemberOperator();
1199
1200  return Function;
1201}
1202
1203Decl *
1204TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1205                                      TemplateParameterList *TemplateParams) {
1206  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1207  void *InsertPos = 0;
1208  if (FunctionTemplate && !TemplateParams) {
1209    // We are creating a function template specialization from a function
1210    // template. Check whether there is already a function template
1211    // specialization for this particular set of template arguments.
1212    llvm::FoldingSetNodeID ID;
1213    FunctionTemplateSpecializationInfo::Profile(ID,
1214                            TemplateArgs.getInnermost().getFlatArgumentList(),
1215                                      TemplateArgs.getInnermost().flat_size(),
1216                                                SemaRef.Context);
1217
1218    FunctionTemplateSpecializationInfo *Info
1219      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
1220                                                                   InsertPos);
1221
1222    // If we already have a function template specialization, return it.
1223    if (Info)
1224      return Info->Function;
1225  }
1226
1227  bool isFriend;
1228  if (FunctionTemplate)
1229    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1230  else
1231    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1232
1233  bool MergeWithParentScope = (TemplateParams != 0) ||
1234    !(isa<Decl>(Owner) &&
1235      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1236  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1237
1238  llvm::SmallVector<ParmVarDecl *, 4> Params;
1239  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1240  TInfo = SubstFunctionType(D, Params);
1241  if (!TInfo)
1242    return 0;
1243  QualType T = TInfo->getType();
1244
1245  // \brief If the type of this function is not *directly* a function
1246  // type, then we're instantiating the a function that was declared
1247  // via a typedef, e.g.,
1248  //
1249  //   typedef int functype(int, int);
1250  //   functype func;
1251  //
1252  // In this case, we'll just go instantiate the ParmVarDecls that we
1253  // synthesized in the method declaration.
1254  if (!isa<FunctionProtoType>(T)) {
1255    assert(!Params.size() && "Instantiating type could not yield parameters");
1256    for (unsigned I = 0, N = D->getNumParams(); I != N; ++I) {
1257      ParmVarDecl *P = SemaRef.SubstParmVarDecl(D->getParamDecl(I),
1258                                                TemplateArgs);
1259      if (!P)
1260        return 0;
1261
1262      Params.push_back(P);
1263    }
1264  }
1265
1266  NestedNameSpecifier *Qualifier = D->getQualifier();
1267  if (Qualifier) {
1268    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1269                                                 D->getQualifierRange(),
1270                                                 TemplateArgs);
1271    if (!Qualifier) return 0;
1272  }
1273
1274  DeclContext *DC = Owner;
1275  if (isFriend) {
1276    if (Qualifier) {
1277      CXXScopeSpec SS;
1278      SS.setScopeRep(Qualifier);
1279      SS.setRange(D->getQualifierRange());
1280      DC = SemaRef.computeDeclContext(SS);
1281    } else {
1282      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1283                                           D->getDeclContext(),
1284                                           TemplateArgs);
1285    }
1286    if (!DC) return 0;
1287  }
1288
1289  // Build the instantiated method declaration.
1290  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1291  CXXMethodDecl *Method = 0;
1292
1293  DeclarationName Name = D->getDeclName();
1294  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1295    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1296    Name = SemaRef.Context.DeclarationNames.getCXXConstructorName(
1297                                    SemaRef.Context.getCanonicalType(ClassTy));
1298    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1299                                        Constructor->getLocation(),
1300                                        Name, T, TInfo,
1301                                        Constructor->isExplicit(),
1302                                        Constructor->isInlineSpecified(),
1303                                        false);
1304  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1305    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1306    Name = SemaRef.Context.DeclarationNames.getCXXDestructorName(
1307                                   SemaRef.Context.getCanonicalType(ClassTy));
1308    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1309                                       Destructor->getLocation(), Name,
1310                                       T, Destructor->isInlineSpecified(),
1311                                       false);
1312  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1313    CanQualType ConvTy
1314      = SemaRef.Context.getCanonicalType(
1315                                      T->getAs<FunctionType>()->getResultType());
1316    Name = SemaRef.Context.DeclarationNames.getCXXConversionFunctionName(
1317                                                                      ConvTy);
1318    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1319                                       Conversion->getLocation(), Name,
1320                                       T, TInfo,
1321                                       Conversion->isInlineSpecified(),
1322                                       Conversion->isExplicit());
1323  } else {
1324    Method = CXXMethodDecl::Create(SemaRef.Context, Record, D->getLocation(),
1325                                   D->getDeclName(), T, TInfo,
1326                                   D->isStatic(),
1327                                   D->getStorageClassAsWritten(),
1328                                   D->isInlineSpecified());
1329  }
1330
1331  if (Qualifier)
1332    Method->setQualifierInfo(Qualifier, D->getQualifierRange());
1333
1334  if (TemplateParams) {
1335    // Our resulting instantiation is actually a function template, since we
1336    // are substituting only the outer template parameters. For example, given
1337    //
1338    //   template<typename T>
1339    //   struct X {
1340    //     template<typename U> void f(T, U);
1341    //   };
1342    //
1343    //   X<int> x;
1344    //
1345    // We are instantiating the member template "f" within X<int>, which means
1346    // substituting int for T, but leaving "f" as a member function template.
1347    // Build the function template itself.
1348    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1349                                                    Method->getLocation(),
1350                                                    Method->getDeclName(),
1351                                                    TemplateParams, Method);
1352    if (isFriend) {
1353      FunctionTemplate->setLexicalDeclContext(Owner);
1354      FunctionTemplate->setObjectOfFriendDecl(true);
1355    } else if (D->isOutOfLine())
1356      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1357    Method->setDescribedFunctionTemplate(FunctionTemplate);
1358  } else if (FunctionTemplate) {
1359    // Record this function template specialization.
1360    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1361                                              &TemplateArgs.getInnermost(),
1362                                              InsertPos);
1363  } else if (!isFriend) {
1364    // Record that this is an instantiation of a member function.
1365    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1366  }
1367
1368  // If we are instantiating a member function defined
1369  // out-of-line, the instantiation will have the same lexical
1370  // context (which will be a namespace scope) as the template.
1371  if (isFriend) {
1372    Method->setLexicalDeclContext(Owner);
1373    Method->setObjectOfFriendDecl(true);
1374  } else if (D->isOutOfLine())
1375    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1376
1377  // Attach the parameters
1378  for (unsigned P = 0; P < Params.size(); ++P)
1379    Params[P]->setOwningFunction(Method);
1380  Method->setParams(Params.data(), Params.size());
1381
1382  if (InitMethodInstantiation(Method, D))
1383    Method->setInvalidDecl();
1384
1385  LookupResult Previous(SemaRef, Name, SourceLocation(),
1386                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1387
1388  if (!FunctionTemplate || TemplateParams || isFriend) {
1389    SemaRef.LookupQualifiedName(Previous, Record);
1390
1391    // In C++, the previous declaration we find might be a tag type
1392    // (class or enum). In this case, the new declaration will hide the
1393    // tag type. Note that this does does not apply if we're declaring a
1394    // typedef (C++ [dcl.typedef]p4).
1395    if (Previous.isSingleTagDecl())
1396      Previous.clear();
1397  }
1398
1399  bool Redeclaration = false;
1400  bool OverloadableAttrRequired = false;
1401  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1402                                   /*FIXME:*/OverloadableAttrRequired);
1403
1404  if (D->isPure())
1405    SemaRef.CheckPureMethod(Method, SourceRange());
1406
1407  Method->setAccess(D->getAccess());
1408
1409  if (FunctionTemplate) {
1410    // If there's a function template, let our caller handle it.
1411  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1412    // Don't hide a (potentially) valid declaration with an invalid one.
1413  } else {
1414    NamedDecl *DeclToAdd = (TemplateParams
1415                            ? cast<NamedDecl>(FunctionTemplate)
1416                            : Method);
1417    if (isFriend)
1418      Record->makeDeclVisibleInContext(DeclToAdd);
1419    else
1420      Owner->addDecl(DeclToAdd);
1421  }
1422
1423  return Method;
1424}
1425
1426Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1427  return VisitCXXMethodDecl(D);
1428}
1429
1430Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1431  return VisitCXXMethodDecl(D);
1432}
1433
1434Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1435  return VisitCXXMethodDecl(D);
1436}
1437
1438ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1439  return SemaRef.SubstParmVarDecl(D, TemplateArgs);
1440}
1441
1442Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1443                                                    TemplateTypeParmDecl *D) {
1444  // TODO: don't always clone when decls are refcounted.
1445  const Type* T = D->getTypeForDecl();
1446  assert(T->isTemplateTypeParmType());
1447  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1448
1449  TemplateTypeParmDecl *Inst =
1450    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1451                                 TTPT->getDepth() - 1, TTPT->getIndex(),
1452                                 TTPT->getName(),
1453                                 D->wasDeclaredWithTypename(),
1454                                 D->isParameterPack());
1455
1456  if (D->hasDefaultArgument())
1457    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1458
1459  // Introduce this template parameter's instantiation into the instantiation
1460  // scope.
1461  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1462
1463  return Inst;
1464}
1465
1466Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1467                                                 NonTypeTemplateParmDecl *D) {
1468  // Substitute into the type of the non-type template parameter.
1469  QualType T;
1470  TypeSourceInfo *DI = D->getTypeSourceInfo();
1471  if (DI) {
1472    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1473                           D->getDeclName());
1474    if (DI) T = DI->getType();
1475  } else {
1476    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1477                          D->getDeclName());
1478    DI = 0;
1479  }
1480  if (T.isNull())
1481    return 0;
1482
1483  // Check that this type is acceptable for a non-type template parameter.
1484  bool Invalid = false;
1485  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1486  if (T.isNull()) {
1487    T = SemaRef.Context.IntTy;
1488    Invalid = true;
1489  }
1490
1491  NonTypeTemplateParmDecl *Param
1492    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1493                                      D->getDepth() - 1, D->getPosition(),
1494                                      D->getIdentifier(), T, DI);
1495  if (Invalid)
1496    Param->setInvalidDecl();
1497
1498  Param->setDefaultArgument(D->getDefaultArgument());
1499
1500  // Introduce this template parameter's instantiation into the instantiation
1501  // scope.
1502  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1503  return Param;
1504}
1505
1506Decl *
1507TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1508                                                  TemplateTemplateParmDecl *D) {
1509  // Instantiate the template parameter list of the template template parameter.
1510  TemplateParameterList *TempParams = D->getTemplateParameters();
1511  TemplateParameterList *InstParams;
1512  {
1513    // Perform the actual substitution of template parameters within a new,
1514    // local instantiation scope.
1515    Sema::LocalInstantiationScope Scope(SemaRef);
1516    InstParams = SubstTemplateParams(TempParams);
1517    if (!InstParams)
1518      return NULL;
1519  }
1520
1521  // Build the template template parameter.
1522  TemplateTemplateParmDecl *Param
1523    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1524                                       D->getDepth() - 1, D->getPosition(),
1525                                       D->getIdentifier(), InstParams);
1526  Param->setDefaultArgument(D->getDefaultArgument());
1527
1528  // Introduce this template parameter's instantiation into the instantiation
1529  // scope.
1530  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1531
1532  return Param;
1533}
1534
1535Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1536  // Using directives are never dependent, so they require no explicit
1537
1538  UsingDirectiveDecl *Inst
1539    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1540                                 D->getNamespaceKeyLocation(),
1541                                 D->getQualifierRange(), D->getQualifier(),
1542                                 D->getIdentLocation(),
1543                                 D->getNominatedNamespace(),
1544                                 D->getCommonAncestor());
1545  Owner->addDecl(Inst);
1546  return Inst;
1547}
1548
1549Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1550  // The nested name specifier is non-dependent, so no transformation
1551  // is required.
1552
1553  // We only need to do redeclaration lookups if we're in a class
1554  // scope (in fact, it's not really even possible in non-class
1555  // scopes).
1556  bool CheckRedeclaration = Owner->isRecord();
1557
1558  LookupResult Prev(SemaRef, D->getDeclName(), D->getLocation(),
1559                    Sema::LookupUsingDeclName, Sema::ForRedeclaration);
1560
1561  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1562                                       D->getLocation(),
1563                                       D->getNestedNameRange(),
1564                                       D->getUsingLocation(),
1565                                       D->getTargetNestedNameDecl(),
1566                                       D->getDeclName(),
1567                                       D->isTypeName());
1568
1569  CXXScopeSpec SS;
1570  SS.setScopeRep(D->getTargetNestedNameDecl());
1571  SS.setRange(D->getNestedNameRange());
1572
1573  if (CheckRedeclaration) {
1574    Prev.setHideTags(false);
1575    SemaRef.LookupQualifiedName(Prev, Owner);
1576
1577    // Check for invalid redeclarations.
1578    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1579                                            D->isTypeName(), SS,
1580                                            D->getLocation(), Prev))
1581      NewUD->setInvalidDecl();
1582
1583  }
1584
1585  if (!NewUD->isInvalidDecl() &&
1586      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1587                                      D->getLocation()))
1588    NewUD->setInvalidDecl();
1589
1590  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1591  NewUD->setAccess(D->getAccess());
1592  Owner->addDecl(NewUD);
1593
1594  // Don't process the shadow decls for an invalid decl.
1595  if (NewUD->isInvalidDecl())
1596    return NewUD;
1597
1598  bool isFunctionScope = Owner->isFunctionOrMethod();
1599
1600  // Process the shadow decls.
1601  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1602         I != E; ++I) {
1603    UsingShadowDecl *Shadow = *I;
1604    NamedDecl *InstTarget =
1605      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1606                                                   Shadow->getTargetDecl(),
1607                                                   TemplateArgs));
1608
1609    if (CheckRedeclaration &&
1610        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1611      continue;
1612
1613    UsingShadowDecl *InstShadow
1614      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1615    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1616
1617    if (isFunctionScope)
1618      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1619  }
1620
1621  return NewUD;
1622}
1623
1624Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1625  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1626  return 0;
1627}
1628
1629Decl * TemplateDeclInstantiator
1630    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1631  NestedNameSpecifier *NNS =
1632    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1633                                     D->getTargetNestedNameRange(),
1634                                     TemplateArgs);
1635  if (!NNS)
1636    return 0;
1637
1638  CXXScopeSpec SS;
1639  SS.setRange(D->getTargetNestedNameRange());
1640  SS.setScopeRep(NNS);
1641
1642  NamedDecl *UD =
1643    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1644                                  D->getUsingLoc(), SS, D->getLocation(),
1645                                  D->getDeclName(), 0,
1646                                  /*instantiation*/ true,
1647                                  /*typename*/ true, D->getTypenameLoc());
1648  if (UD)
1649    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1650
1651  return UD;
1652}
1653
1654Decl * TemplateDeclInstantiator
1655    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1656  NestedNameSpecifier *NNS =
1657    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1658                                     D->getTargetNestedNameRange(),
1659                                     TemplateArgs);
1660  if (!NNS)
1661    return 0;
1662
1663  CXXScopeSpec SS;
1664  SS.setRange(D->getTargetNestedNameRange());
1665  SS.setScopeRep(NNS);
1666
1667  NamedDecl *UD =
1668    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1669                                  D->getUsingLoc(), SS, D->getLocation(),
1670                                  D->getDeclName(), 0,
1671                                  /*instantiation*/ true,
1672                                  /*typename*/ false, SourceLocation());
1673  if (UD)
1674    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1675
1676  return UD;
1677}
1678
1679Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1680                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1681  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1682  if (D->isInvalidDecl())
1683    return 0;
1684
1685  return Instantiator.Visit(D);
1686}
1687
1688/// \brief Instantiates a nested template parameter list in the current
1689/// instantiation context.
1690///
1691/// \param L The parameter list to instantiate
1692///
1693/// \returns NULL if there was an error
1694TemplateParameterList *
1695TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1696  // Get errors for all the parameters before bailing out.
1697  bool Invalid = false;
1698
1699  unsigned N = L->size();
1700  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1701  ParamVector Params;
1702  Params.reserve(N);
1703  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1704       PI != PE; ++PI) {
1705    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1706    Params.push_back(D);
1707    Invalid = Invalid || !D || D->isInvalidDecl();
1708  }
1709
1710  // Clean up if we had an error.
1711  if (Invalid) {
1712    for (ParamVector::iterator PI = Params.begin(), PE = Params.end();
1713         PI != PE; ++PI)
1714      if (*PI)
1715        (*PI)->Destroy(SemaRef.Context);
1716    return NULL;
1717  }
1718
1719  TemplateParameterList *InstL
1720    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1721                                    L->getLAngleLoc(), &Params.front(), N,
1722                                    L->getRAngleLoc());
1723  return InstL;
1724}
1725
1726/// \brief Instantiate the declaration of a class template partial
1727/// specialization.
1728///
1729/// \param ClassTemplate the (instantiated) class template that is partially
1730// specialized by the instantiation of \p PartialSpec.
1731///
1732/// \param PartialSpec the (uninstantiated) class template partial
1733/// specialization that we are instantiating.
1734///
1735/// \returns true if there was an error, false otherwise.
1736bool
1737TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1738                                            ClassTemplateDecl *ClassTemplate,
1739                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1740  // Create a local instantiation scope for this class template partial
1741  // specialization, which will contain the instantiations of the template
1742  // parameters.
1743  Sema::LocalInstantiationScope Scope(SemaRef);
1744
1745  // Substitute into the template parameters of the class template partial
1746  // specialization.
1747  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1748  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1749  if (!InstParams)
1750    return true;
1751
1752  // Substitute into the template arguments of the class template partial
1753  // specialization.
1754  const TemplateArgumentLoc *PartialSpecTemplateArgs
1755    = PartialSpec->getTemplateArgsAsWritten();
1756  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1757
1758  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1759  for (unsigned I = 0; I != N; ++I) {
1760    TemplateArgumentLoc Loc;
1761    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1762      return true;
1763    InstTemplateArgs.addArgument(Loc);
1764  }
1765
1766
1767  // Check that the template argument list is well-formed for this
1768  // class template.
1769  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1770                                        InstTemplateArgs.size());
1771  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1772                                        PartialSpec->getLocation(),
1773                                        InstTemplateArgs,
1774                                        false,
1775                                        Converted))
1776    return true;
1777
1778  // Figure out where to insert this class template partial specialization
1779  // in the member template's set of class template partial specializations.
1780  llvm::FoldingSetNodeID ID;
1781  ClassTemplatePartialSpecializationDecl::Profile(ID,
1782                                                  Converted.getFlatArguments(),
1783                                                  Converted.flatSize(),
1784                                                  SemaRef.Context);
1785  void *InsertPos = 0;
1786  ClassTemplateSpecializationDecl *PrevDecl
1787    = ClassTemplate->getPartialSpecializations().FindNodeOrInsertPos(ID,
1788                                                                     InsertPos);
1789
1790  // Build the canonical type that describes the converted template
1791  // arguments of the class template partial specialization.
1792  QualType CanonType
1793    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1794                                                  Converted.getFlatArguments(),
1795                                                    Converted.flatSize());
1796
1797  // Build the fully-sugared type for this class template
1798  // specialization as the user wrote in the specialization
1799  // itself. This means that we'll pretty-print the type retrieved
1800  // from the specialization's declaration the way that the user
1801  // actually wrote the specialization, rather than formatting the
1802  // name based on the "canonical" representation used to store the
1803  // template arguments in the specialization.
1804  TypeSourceInfo *WrittenTy
1805    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1806                                                    TemplateName(ClassTemplate),
1807                                                    PartialSpec->getLocation(),
1808                                                    InstTemplateArgs,
1809                                                    CanonType);
1810
1811  if (PrevDecl) {
1812    // We've already seen a partial specialization with the same template
1813    // parameters and template arguments. This can happen, for example, when
1814    // substituting the outer template arguments ends up causing two
1815    // class template partial specializations of a member class template
1816    // to have identical forms, e.g.,
1817    //
1818    //   template<typename T, typename U>
1819    //   struct Outer {
1820    //     template<typename X, typename Y> struct Inner;
1821    //     template<typename Y> struct Inner<T, Y>;
1822    //     template<typename Y> struct Inner<U, Y>;
1823    //   };
1824    //
1825    //   Outer<int, int> outer; // error: the partial specializations of Inner
1826    //                          // have the same signature.
1827    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1828      << WrittenTy;
1829    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1830      << SemaRef.Context.getTypeDeclType(PrevDecl);
1831    return true;
1832  }
1833
1834
1835  // Create the class template partial specialization declaration.
1836  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1837    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
1838                                                     PartialSpec->getTagKind(),
1839                                                     Owner,
1840                                                     PartialSpec->getLocation(),
1841                                                     InstParams,
1842                                                     ClassTemplate,
1843                                                     Converted,
1844                                                     InstTemplateArgs,
1845                                                     CanonType,
1846                                                     0,
1847                             ClassTemplate->getPartialSpecializations().size());
1848  // Substitute the nested name specifier, if any.
1849  if (SubstQualifier(PartialSpec, InstPartialSpec))
1850    return 0;
1851
1852  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1853  InstPartialSpec->setTypeAsWritten(WrittenTy);
1854
1855  // Add this partial specialization to the set of class template partial
1856  // specializations.
1857  ClassTemplate->getPartialSpecializations().InsertNode(InstPartialSpec,
1858                                                        InsertPos);
1859  return false;
1860}
1861
1862TypeSourceInfo*
1863TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1864                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1865  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1866  assert(OldTInfo && "substituting function without type source info");
1867  assert(Params.empty() && "parameter vector is non-empty at start");
1868  TypeSourceInfo *NewTInfo
1869    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
1870                                    D->getTypeSpecStartLoc(),
1871                                    D->getDeclName());
1872  if (!NewTInfo)
1873    return 0;
1874
1875  if (NewTInfo != OldTInfo) {
1876    // Get parameters from the new type info.
1877    TypeLoc OldTL = OldTInfo->getTypeLoc();
1878    if (FunctionProtoTypeLoc *OldProtoLoc
1879                                  = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1880      TypeLoc NewTL = NewTInfo->getTypeLoc();
1881      FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1882      assert(NewProtoLoc && "Missing prototype?");
1883      for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i) {
1884        // FIXME: Variadic templates will break this.
1885        Params.push_back(NewProtoLoc->getArg(i));
1886        SemaRef.CurrentInstantiationScope->InstantiatedLocal(
1887                                                        OldProtoLoc->getArg(i),
1888                                                        NewProtoLoc->getArg(i));
1889      }
1890    }
1891  } else {
1892    // The function type itself was not dependent and therefore no
1893    // substitution occurred. However, we still need to instantiate
1894    // the function parameters themselves.
1895    TypeLoc OldTL = OldTInfo->getTypeLoc();
1896    if (FunctionProtoTypeLoc *OldProtoLoc
1897                                    = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1898      for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
1899        ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
1900        if (!Parm)
1901          return 0;
1902        Params.push_back(Parm);
1903      }
1904    }
1905  }
1906  return NewTInfo;
1907}
1908
1909/// \brief Initializes the common fields of an instantiation function
1910/// declaration (New) from the corresponding fields of its template (Tmpl).
1911///
1912/// \returns true if there was an error
1913bool
1914TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1915                                                    FunctionDecl *Tmpl) {
1916  if (Tmpl->isDeleted())
1917    New->setDeleted();
1918
1919  // If we are performing substituting explicitly-specified template arguments
1920  // or deduced template arguments into a function template and we reach this
1921  // point, we are now past the point where SFINAE applies and have committed
1922  // to keeping the new function template specialization. We therefore
1923  // convert the active template instantiation for the function template
1924  // into a template instantiation for this specific function template
1925  // specialization, which is not a SFINAE context, so that we diagnose any
1926  // further errors in the declaration itself.
1927  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1928  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1929  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1930      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1931    if (FunctionTemplateDecl *FunTmpl
1932          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1933      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1934             "Deduction from the wrong function template?");
1935      (void) FunTmpl;
1936      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1937      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1938      --SemaRef.NonInstantiationEntries;
1939    }
1940  }
1941
1942  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1943  assert(Proto && "Function template without prototype?");
1944
1945  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1946      Proto->getNoReturnAttr()) {
1947    // The function has an exception specification or a "noreturn"
1948    // attribute. Substitute into each of the exception types.
1949    llvm::SmallVector<QualType, 4> Exceptions;
1950    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1951      // FIXME: Poor location information!
1952      QualType T
1953        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1954                            New->getLocation(), New->getDeclName());
1955      if (T.isNull() ||
1956          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1957        continue;
1958
1959      Exceptions.push_back(T);
1960    }
1961
1962    // Rebuild the function type
1963
1964    const FunctionProtoType *NewProto
1965      = New->getType()->getAs<FunctionProtoType>();
1966    assert(NewProto && "Template instantiation without function prototype?");
1967    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1968                                                 NewProto->arg_type_begin(),
1969                                                 NewProto->getNumArgs(),
1970                                                 NewProto->isVariadic(),
1971                                                 NewProto->getTypeQuals(),
1972                                                 Proto->hasExceptionSpec(),
1973                                                 Proto->hasAnyExceptionSpec(),
1974                                                 Exceptions.size(),
1975                                                 Exceptions.data(),
1976                                                 Proto->getExtInfo()));
1977  }
1978
1979  return false;
1980}
1981
1982/// \brief Initializes common fields of an instantiated method
1983/// declaration (New) from the corresponding fields of its template
1984/// (Tmpl).
1985///
1986/// \returns true if there was an error
1987bool
1988TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
1989                                                  CXXMethodDecl *Tmpl) {
1990  if (InitFunctionInstantiation(New, Tmpl))
1991    return true;
1992
1993  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
1994  New->setAccess(Tmpl->getAccess());
1995  if (Tmpl->isVirtualAsWritten())
1996    Record->setMethodAsVirtual(New);
1997
1998  // FIXME: attributes
1999  // FIXME: New needs a pointer to Tmpl
2000  return false;
2001}
2002
2003/// \brief Instantiate the definition of the given function from its
2004/// template.
2005///
2006/// \param PointOfInstantiation the point at which the instantiation was
2007/// required. Note that this is not precisely a "point of instantiation"
2008/// for the function, but it's close.
2009///
2010/// \param Function the already-instantiated declaration of a
2011/// function template specialization or member function of a class template
2012/// specialization.
2013///
2014/// \param Recursive if true, recursively instantiates any functions that
2015/// are required by this instantiation.
2016///
2017/// \param DefinitionRequired if true, then we are performing an explicit
2018/// instantiation where the body of the function is required. Complain if
2019/// there is no such body.
2020void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
2021                                         FunctionDecl *Function,
2022                                         bool Recursive,
2023                                         bool DefinitionRequired) {
2024  if (Function->isInvalidDecl() || Function->getBody())
2025    return;
2026
2027  // Never instantiate an explicit specialization.
2028  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2029    return;
2030
2031  // Find the function body that we'll be substituting.
2032  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
2033  Stmt *Pattern = 0;
2034  if (PatternDecl)
2035    Pattern = PatternDecl->getBody(PatternDecl);
2036
2037  if (!Pattern) {
2038    if (DefinitionRequired) {
2039      if (Function->getPrimaryTemplate())
2040        Diag(PointOfInstantiation,
2041             diag::err_explicit_instantiation_undefined_func_template)
2042          << Function->getPrimaryTemplate();
2043      else
2044        Diag(PointOfInstantiation,
2045             diag::err_explicit_instantiation_undefined_member)
2046          << 1 << Function->getDeclName() << Function->getDeclContext();
2047
2048      if (PatternDecl)
2049        Diag(PatternDecl->getLocation(),
2050             diag::note_explicit_instantiation_here);
2051      Function->setInvalidDecl();
2052    }
2053
2054    return;
2055  }
2056
2057  // C++0x [temp.explicit]p9:
2058  //   Except for inline functions, other explicit instantiation declarations
2059  //   have the effect of suppressing the implicit instantiation of the entity
2060  //   to which they refer.
2061  if (Function->getTemplateSpecializationKind()
2062        == TSK_ExplicitInstantiationDeclaration &&
2063      !PatternDecl->isInlined())
2064    return;
2065
2066  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2067  if (Inst)
2068    return;
2069
2070  // If we're performing recursive template instantiation, create our own
2071  // queue of pending implicit instantiations that we will instantiate later,
2072  // while we're still within our own instantiation context.
2073  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2074  if (Recursive)
2075    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2076
2077  EnterExpressionEvaluationContext EvalContext(*this,
2078                                               Action::PotentiallyEvaluated);
2079  ActOnStartOfFunctionDef(0, DeclPtrTy::make(Function));
2080
2081  // Introduce a new scope where local variable instantiations will be
2082  // recorded, unless we're actually a member function within a local
2083  // class, in which case we need to merge our results with the parent
2084  // scope (of the enclosing function).
2085  bool MergeWithParentScope = false;
2086  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2087    MergeWithParentScope = Rec->isLocalClass();
2088
2089  LocalInstantiationScope Scope(*this, MergeWithParentScope);
2090
2091  // Introduce the instantiated function parameters into the local
2092  // instantiation scope.
2093  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I)
2094    Scope.InstantiatedLocal(PatternDecl->getParamDecl(I),
2095                            Function->getParamDecl(I));
2096
2097  // Enter the scope of this instantiation. We don't use
2098  // PushDeclContext because we don't have a scope.
2099  DeclContext *PreviousContext = CurContext;
2100  CurContext = Function;
2101
2102  MultiLevelTemplateArgumentList TemplateArgs =
2103    getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
2104
2105  // If this is a constructor, instantiate the member initializers.
2106  if (const CXXConstructorDecl *Ctor =
2107        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2108    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2109                               TemplateArgs);
2110  }
2111
2112  // Instantiate the function body.
2113  OwningStmtResult Body = SubstStmt(Pattern, TemplateArgs);
2114
2115  if (Body.isInvalid())
2116    Function->setInvalidDecl();
2117
2118  ActOnFinishFunctionBody(DeclPtrTy::make(Function), move(Body),
2119                          /*IsInstantiation=*/true);
2120
2121  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2122
2123  CurContext = PreviousContext;
2124
2125  DeclGroupRef DG(Function);
2126  Consumer.HandleTopLevelDecl(DG);
2127
2128  // This class may have local implicit instantiations that need to be
2129  // instantiation within this scope.
2130  PerformPendingImplicitInstantiations(/*LocalOnly=*/true);
2131  Scope.Exit();
2132
2133  if (Recursive) {
2134    // Instantiate any pending implicit instantiations found during the
2135    // instantiation of this template.
2136    PerformPendingImplicitInstantiations();
2137
2138    // Restore the set of pending implicit instantiations.
2139    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2140  }
2141}
2142
2143/// \brief Instantiate the definition of the given variable from its
2144/// template.
2145///
2146/// \param PointOfInstantiation the point at which the instantiation was
2147/// required. Note that this is not precisely a "point of instantiation"
2148/// for the function, but it's close.
2149///
2150/// \param Var the already-instantiated declaration of a static member
2151/// variable of a class template specialization.
2152///
2153/// \param Recursive if true, recursively instantiates any functions that
2154/// are required by this instantiation.
2155///
2156/// \param DefinitionRequired if true, then we are performing an explicit
2157/// instantiation where an out-of-line definition of the member variable
2158/// is required. Complain if there is no such definition.
2159void Sema::InstantiateStaticDataMemberDefinition(
2160                                          SourceLocation PointOfInstantiation,
2161                                                 VarDecl *Var,
2162                                                 bool Recursive,
2163                                                 bool DefinitionRequired) {
2164  if (Var->isInvalidDecl())
2165    return;
2166
2167  // Find the out-of-line definition of this static data member.
2168  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2169  assert(Def && "This data member was not instantiated from a template?");
2170  assert(Def->isStaticDataMember() && "Not a static data member?");
2171  Def = Def->getOutOfLineDefinition();
2172
2173  if (!Def) {
2174    // We did not find an out-of-line definition of this static data member,
2175    // so we won't perform any instantiation. Rather, we rely on the user to
2176    // instantiate this definition (or provide a specialization for it) in
2177    // another translation unit.
2178    if (DefinitionRequired) {
2179      Def = Var->getInstantiatedFromStaticDataMember();
2180      Diag(PointOfInstantiation,
2181           diag::err_explicit_instantiation_undefined_member)
2182        << 2 << Var->getDeclName() << Var->getDeclContext();
2183      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2184    }
2185
2186    return;
2187  }
2188
2189  // Never instantiate an explicit specialization.
2190  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2191    return;
2192
2193  // C++0x [temp.explicit]p9:
2194  //   Except for inline functions, other explicit instantiation declarations
2195  //   have the effect of suppressing the implicit instantiation of the entity
2196  //   to which they refer.
2197  if (Var->getTemplateSpecializationKind()
2198        == TSK_ExplicitInstantiationDeclaration)
2199    return;
2200
2201  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2202  if (Inst)
2203    return;
2204
2205  // If we're performing recursive template instantiation, create our own
2206  // queue of pending implicit instantiations that we will instantiate later,
2207  // while we're still within our own instantiation context.
2208  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2209  if (Recursive)
2210    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2211
2212  // Enter the scope of this instantiation. We don't use
2213  // PushDeclContext because we don't have a scope.
2214  DeclContext *PreviousContext = CurContext;
2215  CurContext = Var->getDeclContext();
2216
2217  VarDecl *OldVar = Var;
2218  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2219                                          getTemplateInstantiationArgs(Var)));
2220  CurContext = PreviousContext;
2221
2222  if (Var) {
2223    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2224    assert(MSInfo && "Missing member specialization information?");
2225    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2226                                       MSInfo->getPointOfInstantiation());
2227    DeclGroupRef DG(Var);
2228    Consumer.HandleTopLevelDecl(DG);
2229  }
2230
2231  if (Recursive) {
2232    // Instantiate any pending implicit instantiations found during the
2233    // instantiation of this template.
2234    PerformPendingImplicitInstantiations();
2235
2236    // Restore the set of pending implicit instantiations.
2237    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2238  }
2239}
2240
2241void
2242Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2243                                 const CXXConstructorDecl *Tmpl,
2244                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2245
2246  llvm::SmallVector<MemInitTy*, 4> NewInits;
2247  bool AnyErrors = false;
2248
2249  // Instantiate all the initializers.
2250  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2251                                            InitsEnd = Tmpl->init_end();
2252       Inits != InitsEnd; ++Inits) {
2253    CXXBaseOrMemberInitializer *Init = *Inits;
2254
2255    SourceLocation LParenLoc, RParenLoc;
2256    ASTOwningVector<&ActionBase::DeleteExpr> NewArgs(*this);
2257    llvm::SmallVector<SourceLocation, 4> CommaLocs;
2258
2259    // Instantiate the initializer.
2260    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2261                               LParenLoc, CommaLocs, NewArgs, RParenLoc)) {
2262      AnyErrors = true;
2263      continue;
2264    }
2265
2266    MemInitResult NewInit;
2267    if (Init->isBaseInitializer()) {
2268      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2269                                            TemplateArgs,
2270                                            Init->getSourceLocation(),
2271                                            New->getDeclName());
2272      if (!BaseTInfo) {
2273        AnyErrors = true;
2274        New->setInvalidDecl();
2275        continue;
2276      }
2277
2278      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2279                                     (Expr **)NewArgs.data(),
2280                                     NewArgs.size(),
2281                                     Init->getLParenLoc(),
2282                                     Init->getRParenLoc(),
2283                                     New->getParent());
2284    } else if (Init->isMemberInitializer()) {
2285      FieldDecl *Member;
2286
2287      // Is this an anonymous union?
2288      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2289        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2290                                                      UnionInit, TemplateArgs));
2291      else
2292        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2293                                                      Init->getMember(),
2294                                                      TemplateArgs));
2295
2296      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2297                                       NewArgs.size(),
2298                                       Init->getSourceLocation(),
2299                                       Init->getLParenLoc(),
2300                                       Init->getRParenLoc());
2301    }
2302
2303    if (NewInit.isInvalid()) {
2304      AnyErrors = true;
2305      New->setInvalidDecl();
2306    } else {
2307      // FIXME: It would be nice if ASTOwningVector had a release function.
2308      NewArgs.take();
2309
2310      NewInits.push_back((MemInitTy *)NewInit.get());
2311    }
2312  }
2313
2314  // Assign all the initializers to the new constructor.
2315  ActOnMemInitializers(DeclPtrTy::make(New),
2316                       /*FIXME: ColonLoc */
2317                       SourceLocation(),
2318                       NewInits.data(), NewInits.size(),
2319                       AnyErrors);
2320}
2321
2322// TODO: this could be templated if the various decl types used the
2323// same method name.
2324static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2325                              ClassTemplateDecl *Instance) {
2326  Pattern = Pattern->getCanonicalDecl();
2327
2328  do {
2329    Instance = Instance->getCanonicalDecl();
2330    if (Pattern == Instance) return true;
2331    Instance = Instance->getInstantiatedFromMemberTemplate();
2332  } while (Instance);
2333
2334  return false;
2335}
2336
2337static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2338                              FunctionTemplateDecl *Instance) {
2339  Pattern = Pattern->getCanonicalDecl();
2340
2341  do {
2342    Instance = Instance->getCanonicalDecl();
2343    if (Pattern == Instance) return true;
2344    Instance = Instance->getInstantiatedFromMemberTemplate();
2345  } while (Instance);
2346
2347  return false;
2348}
2349
2350static bool
2351isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2352                  ClassTemplatePartialSpecializationDecl *Instance) {
2353  Pattern
2354    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2355  do {
2356    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2357                                                Instance->getCanonicalDecl());
2358    if (Pattern == Instance)
2359      return true;
2360    Instance = Instance->getInstantiatedFromMember();
2361  } while (Instance);
2362
2363  return false;
2364}
2365
2366static bool isInstantiationOf(CXXRecordDecl *Pattern,
2367                              CXXRecordDecl *Instance) {
2368  Pattern = Pattern->getCanonicalDecl();
2369
2370  do {
2371    Instance = Instance->getCanonicalDecl();
2372    if (Pattern == Instance) return true;
2373    Instance = Instance->getInstantiatedFromMemberClass();
2374  } while (Instance);
2375
2376  return false;
2377}
2378
2379static bool isInstantiationOf(FunctionDecl *Pattern,
2380                              FunctionDecl *Instance) {
2381  Pattern = Pattern->getCanonicalDecl();
2382
2383  do {
2384    Instance = Instance->getCanonicalDecl();
2385    if (Pattern == Instance) return true;
2386    Instance = Instance->getInstantiatedFromMemberFunction();
2387  } while (Instance);
2388
2389  return false;
2390}
2391
2392static bool isInstantiationOf(EnumDecl *Pattern,
2393                              EnumDecl *Instance) {
2394  Pattern = Pattern->getCanonicalDecl();
2395
2396  do {
2397    Instance = Instance->getCanonicalDecl();
2398    if (Pattern == Instance) return true;
2399    Instance = Instance->getInstantiatedFromMemberEnum();
2400  } while (Instance);
2401
2402  return false;
2403}
2404
2405static bool isInstantiationOf(UsingShadowDecl *Pattern,
2406                              UsingShadowDecl *Instance,
2407                              ASTContext &C) {
2408  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2409}
2410
2411static bool isInstantiationOf(UsingDecl *Pattern,
2412                              UsingDecl *Instance,
2413                              ASTContext &C) {
2414  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2415}
2416
2417static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2418                              UsingDecl *Instance,
2419                              ASTContext &C) {
2420  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2421}
2422
2423static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2424                              UsingDecl *Instance,
2425                              ASTContext &C) {
2426  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2427}
2428
2429static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2430                                              VarDecl *Instance) {
2431  assert(Instance->isStaticDataMember());
2432
2433  Pattern = Pattern->getCanonicalDecl();
2434
2435  do {
2436    Instance = Instance->getCanonicalDecl();
2437    if (Pattern == Instance) return true;
2438    Instance = Instance->getInstantiatedFromStaticDataMember();
2439  } while (Instance);
2440
2441  return false;
2442}
2443
2444// Other is the prospective instantiation
2445// D is the prospective pattern
2446static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2447  if (D->getKind() != Other->getKind()) {
2448    if (UnresolvedUsingTypenameDecl *UUD
2449          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2450      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2451        return isInstantiationOf(UUD, UD, Ctx);
2452      }
2453    }
2454
2455    if (UnresolvedUsingValueDecl *UUD
2456          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2457      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2458        return isInstantiationOf(UUD, UD, Ctx);
2459      }
2460    }
2461
2462    return false;
2463  }
2464
2465  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2466    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2467
2468  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2469    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2470
2471  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2472    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2473
2474  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2475    if (Var->isStaticDataMember())
2476      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2477
2478  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2479    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2480
2481  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2482    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2483
2484  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2485        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2486    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2487                             PartialSpec);
2488
2489  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2490    if (!Field->getDeclName()) {
2491      // This is an unnamed field.
2492      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2493        cast<FieldDecl>(D);
2494    }
2495  }
2496
2497  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2498    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2499
2500  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2501    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2502
2503  return D->getDeclName() && isa<NamedDecl>(Other) &&
2504    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2505}
2506
2507template<typename ForwardIterator>
2508static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2509                                      NamedDecl *D,
2510                                      ForwardIterator first,
2511                                      ForwardIterator last) {
2512  for (; first != last; ++first)
2513    if (isInstantiationOf(Ctx, D, *first))
2514      return cast<NamedDecl>(*first);
2515
2516  return 0;
2517}
2518
2519/// \brief Finds the instantiation of the given declaration context
2520/// within the current instantiation.
2521///
2522/// \returns NULL if there was an error
2523DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2524                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2525  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2526    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2527    return cast_or_null<DeclContext>(ID);
2528  } else return DC;
2529}
2530
2531/// \brief Find the instantiation of the given declaration within the
2532/// current instantiation.
2533///
2534/// This routine is intended to be used when \p D is a declaration
2535/// referenced from within a template, that needs to mapped into the
2536/// corresponding declaration within an instantiation. For example,
2537/// given:
2538///
2539/// \code
2540/// template<typename T>
2541/// struct X {
2542///   enum Kind {
2543///     KnownValue = sizeof(T)
2544///   };
2545///
2546///   bool getKind() const { return KnownValue; }
2547/// };
2548///
2549/// template struct X<int>;
2550/// \endcode
2551///
2552/// In the instantiation of X<int>::getKind(), we need to map the
2553/// EnumConstantDecl for KnownValue (which refers to
2554/// X<T>::<Kind>::KnownValue) to its instantiation
2555/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2556/// this mapping from within the instantiation of X<int>.
2557NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2558                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2559  DeclContext *ParentDC = D->getDeclContext();
2560  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2561      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2562      ParentDC->isFunctionOrMethod()) {
2563    // D is a local of some kind. Look into the map of local
2564    // declarations to their instantiations.
2565    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2566  }
2567
2568  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2569    if (!Record->isDependentContext())
2570      return D;
2571
2572    // If the RecordDecl is actually the injected-class-name or a
2573    // "templated" declaration for a class template, class template
2574    // partial specialization, or a member class of a class template,
2575    // substitute into the injected-class-name of the class template
2576    // or partial specialization to find the new DeclContext.
2577    QualType T;
2578    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2579
2580    if (ClassTemplate) {
2581      T = ClassTemplate->getInjectedClassNameSpecialization(Context);
2582    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2583                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2584      ClassTemplate = PartialSpec->getSpecializedTemplate();
2585
2586      // If we call SubstType with an InjectedClassNameType here we
2587      // can end up in an infinite loop.
2588      T = Context.getTypeDeclType(Record);
2589      assert(isa<InjectedClassNameType>(T) &&
2590             "type of partial specialization is not an InjectedClassNameType");
2591      T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
2592    }
2593
2594    if (!T.isNull()) {
2595      // Substitute into the injected-class-name to get the type
2596      // corresponding to the instantiation we want, which may also be
2597      // the current instantiation (if we're in a template
2598      // definition). This substitution should never fail, since we
2599      // know we can instantiate the injected-class-name or we
2600      // wouldn't have gotten to the injected-class-name!
2601
2602      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2603      // extra instantiation in the common case?
2604      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2605      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2606
2607      if (!T->isDependentType()) {
2608        assert(T->isRecordType() && "Instantiation must produce a record type");
2609        return T->getAs<RecordType>()->getDecl();
2610      }
2611
2612      // We are performing "partial" template instantiation to create
2613      // the member declarations for the members of a class template
2614      // specialization. Therefore, D is actually referring to something
2615      // in the current instantiation. Look through the current
2616      // context, which contains actual instantiations, to find the
2617      // instantiation of the "current instantiation" that D refers
2618      // to.
2619      bool SawNonDependentContext = false;
2620      for (DeclContext *DC = CurContext; !DC->isFileContext();
2621           DC = DC->getParent()) {
2622        if (ClassTemplateSpecializationDecl *Spec
2623                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2624          if (isInstantiationOf(ClassTemplate,
2625                                Spec->getSpecializedTemplate()))
2626            return Spec;
2627
2628        if (!DC->isDependentContext())
2629          SawNonDependentContext = true;
2630      }
2631
2632      // We're performing "instantiation" of a member of the current
2633      // instantiation while we are type-checking the
2634      // definition. Compute the declaration context and return that.
2635      assert(!SawNonDependentContext &&
2636             "No dependent context while instantiating record");
2637      DeclContext *DC = computeDeclContext(T);
2638      assert(DC &&
2639             "Unable to find declaration for the current instantiation");
2640      return cast<CXXRecordDecl>(DC);
2641    }
2642
2643    // Fall through to deal with other dependent record types (e.g.,
2644    // anonymous unions in class templates).
2645  }
2646
2647  if (!ParentDC->isDependentContext())
2648    return D;
2649
2650  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2651  if (!ParentDC)
2652    return 0;
2653
2654  if (ParentDC != D->getDeclContext()) {
2655    // We performed some kind of instantiation in the parent context,
2656    // so now we need to look into the instantiated parent context to
2657    // find the instantiation of the declaration D.
2658
2659    // If our context used to be dependent, we may need to instantiate
2660    // it before performing lookup into that context.
2661    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2662      if (!Spec->isDependentContext()) {
2663        QualType T = Context.getTypeDeclType(Spec);
2664        const RecordType *Tag = T->getAs<RecordType>();
2665        assert(Tag && "type of non-dependent record is not a RecordType");
2666        if (!Tag->isBeingDefined() &&
2667            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2668          return 0;
2669      }
2670    }
2671
2672    NamedDecl *Result = 0;
2673    if (D->getDeclName()) {
2674      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2675      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2676    } else {
2677      // Since we don't have a name for the entity we're looking for,
2678      // our only option is to walk through all of the declarations to
2679      // find that name. This will occur in a few cases:
2680      //
2681      //   - anonymous struct/union within a template
2682      //   - unnamed class/struct/union/enum within a template
2683      //
2684      // FIXME: Find a better way to find these instantiations!
2685      Result = findInstantiationOf(Context, D,
2686                                   ParentDC->decls_begin(),
2687                                   ParentDC->decls_end());
2688    }
2689
2690    // UsingShadowDecls can instantiate to nothing because of using hiding.
2691    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2692            cast<Decl>(ParentDC)->isInvalidDecl())
2693           && "Unable to find instantiation of declaration!");
2694
2695    D = Result;
2696  }
2697
2698  return D;
2699}
2700
2701/// \brief Performs template instantiation for all implicit template
2702/// instantiations we have seen until this point.
2703void Sema::PerformPendingImplicitInstantiations(bool LocalOnly) {
2704  while (!PendingLocalImplicitInstantiations.empty() ||
2705         (!LocalOnly && !PendingImplicitInstantiations.empty())) {
2706    PendingImplicitInstantiation Inst;
2707
2708    if (PendingLocalImplicitInstantiations.empty()) {
2709      Inst = PendingImplicitInstantiations.front();
2710      PendingImplicitInstantiations.pop_front();
2711    } else {
2712      Inst = PendingLocalImplicitInstantiations.front();
2713      PendingLocalImplicitInstantiations.pop_front();
2714    }
2715
2716    // Instantiate function definitions
2717    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2718      PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Function),
2719                                            Function->getLocation(), *this,
2720                                            Context.getSourceManager(),
2721                                           "instantiating function definition");
2722
2723      InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true);
2724      continue;
2725    }
2726
2727    // Instantiate static data member definitions.
2728    VarDecl *Var = cast<VarDecl>(Inst.first);
2729    assert(Var->isStaticDataMember() && "Not a static data member?");
2730
2731    // Don't try to instantiate declarations if the most recent redeclaration
2732    // is invalid.
2733    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2734      continue;
2735
2736    // Check if the most recent declaration has changed the specialization kind
2737    // and removed the need for implicit instantiation.
2738    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2739    case TSK_Undeclared:
2740      assert(false && "Cannot instantitiate an undeclared specialization.");
2741    case TSK_ExplicitInstantiationDeclaration:
2742    case TSK_ExplicitInstantiationDefinition:
2743    case TSK_ExplicitSpecialization:
2744      continue;  // No longer need implicit instantiation.
2745    case TSK_ImplicitInstantiation:
2746      break;
2747    }
2748
2749    PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Var),
2750                                          Var->getLocation(), *this,
2751                                          Context.getSourceManager(),
2752                                          "instantiating static data member "
2753                                          "definition");
2754
2755    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true);
2756  }
2757}
2758
2759void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2760                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2761  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2762         E = Pattern->ddiag_end(); I != E; ++I) {
2763    DependentDiagnostic *DD = *I;
2764
2765    switch (DD->getKind()) {
2766    case DependentDiagnostic::Access:
2767      HandleDependentAccessCheck(*DD, TemplateArgs);
2768      break;
2769    }
2770  }
2771}
2772