SemaTemplateInstantiateDecl.cpp revision 1b398205267ea69f35230eea50e0225db22ebb7e 
1//===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//===----------------------------------------------------------------------===/
8//
9//  This file implements C++ template instantiation for declarations.
10//
11//===----------------------------------------------------------------------===/
12#include "clang/Sema/SemaInternal.h"
13#include "clang/Sema/Lookup.h"
14#include "clang/Sema/PrettyDeclStackTrace.h"
15#include "clang/Sema/Template.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/DeclTemplate.h"
19#include "clang/AST/DeclVisitor.h"
20#include "clang/AST/DependentDiagnostic.h"
21#include "clang/AST/Expr.h"
22#include "clang/AST/ExprCXX.h"
23#include "clang/AST/TypeLoc.h"
24#include "clang/Lex/Preprocessor.h"
25
26using namespace clang;
27
28namespace {
29  class TemplateDeclInstantiator
30    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
31    Sema &SemaRef;
32    DeclContext *Owner;
33    const MultiLevelTemplateArgumentList &TemplateArgs;
34
35  public:
36    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
37                             const MultiLevelTemplateArgumentList &TemplateArgs)
38      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
39
40    // FIXME: Once we get closer to completion, replace these manually-written
41    // declarations with automatically-generated ones from
42    // clang/AST/DeclNodes.inc.
43    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
44    Decl *VisitNamespaceDecl(NamespaceDecl *D);
45    Decl *VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
46    Decl *VisitTypedefDecl(TypedefDecl *D);
47    Decl *VisitVarDecl(VarDecl *D);
48    Decl *VisitAccessSpecDecl(AccessSpecDecl *D);
49    Decl *VisitFieldDecl(FieldDecl *D);
50    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
51    Decl *VisitEnumDecl(EnumDecl *D);
52    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
53    Decl *VisitFriendDecl(FriendDecl *D);
54    Decl *VisitFunctionDecl(FunctionDecl *D,
55                            TemplateParameterList *TemplateParams = 0);
56    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
57    Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
58                             TemplateParameterList *TemplateParams = 0);
59    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
60    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
61    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
62    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
63    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
64    Decl *VisitClassTemplatePartialSpecializationDecl(
65                                    ClassTemplatePartialSpecializationDecl *D);
66    Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
67    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
68    Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
69    Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
70    Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
71    Decl *VisitUsingDecl(UsingDecl *D);
72    Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
73    Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
74    Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
75
76    // Base case. FIXME: Remove once we can instantiate everything.
77    Decl *VisitDecl(Decl *D) {
78      unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
79                                                            Diagnostic::Error,
80                                                   "cannot instantiate %0 yet");
81      SemaRef.Diag(D->getLocation(), DiagID)
82        << D->getDeclKindName();
83
84      return 0;
85    }
86
87    // Helper functions for instantiating methods.
88    TypeSourceInfo *SubstFunctionType(FunctionDecl *D,
89                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
90    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
91    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
92
93    TemplateParameterList *
94      SubstTemplateParams(TemplateParameterList *List);
95
96    bool SubstQualifier(const DeclaratorDecl *OldDecl,
97                        DeclaratorDecl *NewDecl);
98    bool SubstQualifier(const TagDecl *OldDecl,
99                        TagDecl *NewDecl);
100
101    bool InstantiateClassTemplatePartialSpecialization(
102                                              ClassTemplateDecl *ClassTemplate,
103                           ClassTemplatePartialSpecializationDecl *PartialSpec);
104  };
105}
106
107bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
108                                              DeclaratorDecl *NewDecl) {
109  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
110  if (!OldQual) return false;
111
112  SourceRange QualRange = OldDecl->getQualifierRange();
113
114  NestedNameSpecifier *NewQual
115    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
116  if (!NewQual)
117    return true;
118
119  NewDecl->setQualifierInfo(NewQual, QualRange);
120  return false;
121}
122
123bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
124                                              TagDecl *NewDecl) {
125  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
126  if (!OldQual) return false;
127
128  SourceRange QualRange = OldDecl->getQualifierRange();
129
130  NestedNameSpecifier *NewQual
131    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
132  if (!NewQual)
133    return true;
134
135  NewDecl->setQualifierInfo(NewQual, QualRange);
136  return false;
137}
138
139// FIXME: Is this still too simple?
140void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
141                            Decl *Tmpl, Decl *New) {
142  for (AttrVec::const_iterator i = Tmpl->attr_begin(), e = Tmpl->attr_end();
143       i != e; ++i) {
144    const Attr *TmplAttr = *i;
145    // FIXME: This should be generalized to more than just the AlignedAttr.
146    if (const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr)) {
147      if (Aligned->isAlignmentDependent()) {
148        // The alignment expression is not potentially evaluated.
149        EnterExpressionEvaluationContext Unevaluated(*this,
150                                                     Sema::Unevaluated);
151
152        if (Aligned->isAlignmentExpr()) {
153          ExprResult Result = SubstExpr(Aligned->getAlignmentExpr(),
154                                              TemplateArgs);
155          if (!Result.isInvalid())
156            AddAlignedAttr(Aligned->getLocation(), New, Result.takeAs<Expr>());
157        }
158        else {
159          TypeSourceInfo *Result = SubstType(Aligned->getAlignmentType(),
160                                              TemplateArgs,
161                                              Aligned->getLocation(),
162                                              DeclarationName());
163          if (Result)
164            AddAlignedAttr(Aligned->getLocation(), New, Result);
165        }
166        continue;
167      }
168    }
169
170    // FIXME: Is cloning correct for all attributes?
171    Attr *NewAttr = TmplAttr->clone(Context);
172    New->addAttr(NewAttr);
173  }
174}
175
176Decl *
177TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
178  assert(false && "Translation units cannot be instantiated");
179  return D;
180}
181
182Decl *
183TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
184  assert(false && "Namespaces cannot be instantiated");
185  return D;
186}
187
188Decl *
189TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
190  NamespaceAliasDecl *Inst
191    = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
192                                 D->getNamespaceLoc(),
193                                 D->getAliasLoc(),
194                                 D->getNamespace()->getIdentifier(),
195                                 D->getQualifierRange(),
196                                 D->getQualifier(),
197                                 D->getTargetNameLoc(),
198                                 D->getNamespace());
199  Owner->addDecl(Inst);
200  return Inst;
201}
202
203Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
204  bool Invalid = false;
205  TypeSourceInfo *DI = D->getTypeSourceInfo();
206  if (DI->getType()->isDependentType() ||
207      DI->getType()->isVariablyModifiedType()) {
208    DI = SemaRef.SubstType(DI, TemplateArgs,
209                           D->getLocation(), D->getDeclName());
210    if (!DI) {
211      Invalid = true;
212      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
213    }
214  } else {
215    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
216  }
217
218  // Create the new typedef
219  TypedefDecl *Typedef
220    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
221                          D->getIdentifier(), DI);
222  if (Invalid)
223    Typedef->setInvalidDecl();
224
225  if (const TagType *TT = DI->getType()->getAs<TagType>()) {
226    TagDecl *TD = TT->getDecl();
227
228    // If the TagDecl that the TypedefDecl points to is an anonymous decl
229    // keep track of the TypedefDecl.
230    if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl())
231      TD->setTypedefForAnonDecl(Typedef);
232  }
233
234  if (TypedefDecl *Prev = D->getPreviousDeclaration()) {
235    NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
236                                                       TemplateArgs);
237    Typedef->setPreviousDeclaration(cast<TypedefDecl>(InstPrev));
238  }
239
240  SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef);
241
242  Typedef->setAccess(D->getAccess());
243  Owner->addDecl(Typedef);
244
245  return Typedef;
246}
247
248/// \brief Instantiate the arguments provided as part of initialization.
249///
250/// \returns true if an error occurred, false otherwise.
251static bool InstantiateInitializationArguments(Sema &SemaRef,
252                                               Expr **Args, unsigned NumArgs,
253                           const MultiLevelTemplateArgumentList &TemplateArgs,
254                           ASTOwningVector<Expr*> &InitArgs) {
255  for (unsigned I = 0; I != NumArgs; ++I) {
256    // When we hit the first defaulted argument, break out of the loop:
257    // we don't pass those default arguments on.
258    if (Args[I]->isDefaultArgument())
259      break;
260
261    ExprResult Arg = SemaRef.SubstExpr(Args[I], TemplateArgs);
262    if (Arg.isInvalid())
263      return true;
264
265    InitArgs.push_back(Arg.release());
266  }
267
268  return false;
269}
270
271/// \brief Instantiate an initializer, breaking it into separate
272/// initialization arguments.
273///
274/// \param S The semantic analysis object.
275///
276/// \param Init The initializer to instantiate.
277///
278/// \param TemplateArgs Template arguments to be substituted into the
279/// initializer.
280///
281/// \param NewArgs Will be filled in with the instantiation arguments.
282///
283/// \returns true if an error occurred, false otherwise
284static bool InstantiateInitializer(Sema &S, Expr *Init,
285                            const MultiLevelTemplateArgumentList &TemplateArgs,
286                                   SourceLocation &LParenLoc,
287                             ASTOwningVector<Expr*> &NewArgs,
288                                   SourceLocation &RParenLoc) {
289  NewArgs.clear();
290  LParenLoc = SourceLocation();
291  RParenLoc = SourceLocation();
292
293  if (!Init)
294    return false;
295
296  if (CXXExprWithTemporaries *ExprTemp = dyn_cast<CXXExprWithTemporaries>(Init))
297    Init = ExprTemp->getSubExpr();
298
299  while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init))
300    Init = Binder->getSubExpr();
301
302  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
303    Init = ICE->getSubExprAsWritten();
304
305  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
306    LParenLoc = ParenList->getLParenLoc();
307    RParenLoc = ParenList->getRParenLoc();
308    return InstantiateInitializationArguments(S, ParenList->getExprs(),
309                                              ParenList->getNumExprs(),
310                                              TemplateArgs, NewArgs);
311  }
312
313  if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) {
314    if (!isa<CXXTemporaryObjectExpr>(Construct)) {
315      if (InstantiateInitializationArguments(S,
316                                             Construct->getArgs(),
317                                             Construct->getNumArgs(),
318                                             TemplateArgs, NewArgs))
319        return true;
320
321      // FIXME: Fake locations!
322      LParenLoc = S.PP.getLocForEndOfToken(Init->getLocStart());
323      RParenLoc = LParenLoc;
324      return false;
325    }
326  }
327
328  ExprResult Result = S.SubstExpr(Init, TemplateArgs);
329  if (Result.isInvalid())
330    return true;
331
332  NewArgs.push_back(Result.takeAs<Expr>());
333  return false;
334}
335
336Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
337  // If this is the variable for an anonymous struct or union,
338  // instantiate the anonymous struct/union type first.
339  if (const RecordType *RecordTy = D->getType()->getAs<RecordType>())
340    if (RecordTy->getDecl()->isAnonymousStructOrUnion())
341      if (!VisitCXXRecordDecl(cast<CXXRecordDecl>(RecordTy->getDecl())))
342        return 0;
343
344  // Do substitution on the type of the declaration
345  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
346                                         TemplateArgs,
347                                         D->getTypeSpecStartLoc(),
348                                         D->getDeclName());
349  if (!DI)
350    return 0;
351
352  if (DI->getType()->isFunctionType()) {
353    SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
354      << D->isStaticDataMember() << DI->getType();
355    return 0;
356  }
357
358  // Build the instantiated declaration
359  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
360                                 D->getLocation(), D->getIdentifier(),
361                                 DI->getType(), DI,
362                                 D->getStorageClass(),
363                                 D->getStorageClassAsWritten());
364  Var->setThreadSpecified(D->isThreadSpecified());
365  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
366
367  // Substitute the nested name specifier, if any.
368  if (SubstQualifier(D, Var))
369    return 0;
370
371  // If we are instantiating a static data member defined
372  // out-of-line, the instantiation will have the same lexical
373  // context (which will be a namespace scope) as the template.
374  if (D->isOutOfLine())
375    Var->setLexicalDeclContext(D->getLexicalDeclContext());
376
377  Var->setAccess(D->getAccess());
378
379  if (!D->isStaticDataMember())
380    Var->setUsed(D->isUsed(false));
381
382  // FIXME: In theory, we could have a previous declaration for variables that
383  // are not static data members.
384  bool Redeclaration = false;
385  // FIXME: having to fake up a LookupResult is dumb.
386  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
387                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
388  if (D->isStaticDataMember())
389    SemaRef.LookupQualifiedName(Previous, Owner, false);
390  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
391
392  if (D->isOutOfLine()) {
393    if (!D->isStaticDataMember())
394      D->getLexicalDeclContext()->addDecl(Var);
395    Owner->makeDeclVisibleInContext(Var);
396  } else {
397    Owner->addDecl(Var);
398    if (Owner->isFunctionOrMethod())
399      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Var);
400  }
401  SemaRef.InstantiateAttrs(TemplateArgs, D, Var);
402
403  // Link instantiations of static data members back to the template from
404  // which they were instantiated.
405  if (Var->isStaticDataMember())
406    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
407                                                     TSK_ImplicitInstantiation);
408
409  if (Var->getAnyInitializer()) {
410    // We already have an initializer in the class.
411  } else if (D->getInit()) {
412    if (Var->isStaticDataMember() && !D->isOutOfLine())
413      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
414    else
415      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
416
417    // Instantiate the initializer.
418    SourceLocation LParenLoc, RParenLoc;
419    ASTOwningVector<Expr*> InitArgs(SemaRef);
420    if (!InstantiateInitializer(SemaRef, D->getInit(), TemplateArgs, LParenLoc,
421                                InitArgs, RParenLoc)) {
422      // Attach the initializer to the declaration.
423      if (D->hasCXXDirectInitializer()) {
424        // Add the direct initializer to the declaration.
425        SemaRef.AddCXXDirectInitializerToDecl(Var,
426                                              LParenLoc,
427                                              move_arg(InitArgs),
428                                              RParenLoc);
429      } else if (InitArgs.size() == 1) {
430        Expr *Init = InitArgs.take()[0];
431        SemaRef.AddInitializerToDecl(Var, Init, false);
432      } else {
433        assert(InitArgs.size() == 0);
434        SemaRef.ActOnUninitializedDecl(Var, false);
435      }
436    } else {
437      // FIXME: Not too happy about invalidating the declaration
438      // because of a bogus initializer.
439      Var->setInvalidDecl();
440    }
441
442    SemaRef.PopExpressionEvaluationContext();
443  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
444    SemaRef.ActOnUninitializedDecl(Var, false);
445
446  // Diagnose unused local variables.
447  if (!Var->isInvalidDecl() && Owner->isFunctionOrMethod() && !Var->isUsed())
448    SemaRef.DiagnoseUnusedDecl(Var);
449
450  return Var;
451}
452
453Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
454  AccessSpecDecl* AD
455    = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
456                             D->getAccessSpecifierLoc(), D->getColonLoc());
457  Owner->addHiddenDecl(AD);
458  return AD;
459}
460
461Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
462  bool Invalid = false;
463  TypeSourceInfo *DI = D->getTypeSourceInfo();
464  if (DI->getType()->isDependentType() ||
465      DI->getType()->isVariablyModifiedType())  {
466    DI = SemaRef.SubstType(DI, TemplateArgs,
467                           D->getLocation(), D->getDeclName());
468    if (!DI) {
469      DI = D->getTypeSourceInfo();
470      Invalid = true;
471    } else if (DI->getType()->isFunctionType()) {
472      // C++ [temp.arg.type]p3:
473      //   If a declaration acquires a function type through a type
474      //   dependent on a template-parameter and this causes a
475      //   declaration that does not use the syntactic form of a
476      //   function declarator to have function type, the program is
477      //   ill-formed.
478      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
479        << DI->getType();
480      Invalid = true;
481    }
482  } else {
483    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
484  }
485
486  Expr *BitWidth = D->getBitWidth();
487  if (Invalid)
488    BitWidth = 0;
489  else if (BitWidth) {
490    // The bit-width expression is not potentially evaluated.
491    EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
492
493    ExprResult InstantiatedBitWidth
494      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
495    if (InstantiatedBitWidth.isInvalid()) {
496      Invalid = true;
497      BitWidth = 0;
498    } else
499      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
500  }
501
502  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
503                                            DI->getType(), DI,
504                                            cast<RecordDecl>(Owner),
505                                            D->getLocation(),
506                                            D->isMutable(),
507                                            BitWidth,
508                                            D->getTypeSpecStartLoc(),
509                                            D->getAccess(),
510                                            0);
511  if (!Field) {
512    cast<Decl>(Owner)->setInvalidDecl();
513    return 0;
514  }
515
516  SemaRef.InstantiateAttrs(TemplateArgs, D, Field);
517
518  if (Invalid)
519    Field->setInvalidDecl();
520
521  if (!Field->getDeclName()) {
522    // Keep track of where this decl came from.
523    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
524  }
525  if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
526    if (Parent->isAnonymousStructOrUnion() &&
527        Parent->getRedeclContext()->isFunctionOrMethod())
528      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
529  }
530
531  Field->setImplicit(D->isImplicit());
532  Field->setAccess(D->getAccess());
533  Owner->addDecl(Field);
534
535  return Field;
536}
537
538Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
539  // Handle friend type expressions by simply substituting template
540  // parameters into the pattern type and checking the result.
541  if (TypeSourceInfo *Ty = D->getFriendType()) {
542    TypeSourceInfo *InstTy =
543      SemaRef.SubstType(Ty, TemplateArgs,
544                        D->getLocation(), DeclarationName());
545    if (!InstTy)
546      return 0;
547
548    FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getFriendLoc(), InstTy);
549    if (!FD)
550      return 0;
551
552    FD->setAccess(AS_public);
553    Owner->addDecl(FD);
554    return FD;
555  }
556
557  NamedDecl *ND = D->getFriendDecl();
558  assert(ND && "friend decl must be a decl or a type!");
559
560  // All of the Visit implementations for the various potential friend
561  // declarations have to be carefully written to work for friend
562  // objects, with the most important detail being that the target
563  // decl should almost certainly not be placed in Owner.
564  Decl *NewND = Visit(ND);
565  if (!NewND) return 0;
566
567  FriendDecl *FD =
568    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
569                       cast<NamedDecl>(NewND), D->getFriendLoc());
570  FD->setAccess(AS_public);
571  Owner->addDecl(FD);
572  return FD;
573}
574
575Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
576  Expr *AssertExpr = D->getAssertExpr();
577
578  // The expression in a static assertion is not potentially evaluated.
579  EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
580
581  ExprResult InstantiatedAssertExpr
582    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
583  if (InstantiatedAssertExpr.isInvalid())
584    return 0;
585
586  ExprResult Message(D->getMessage());
587  D->getMessage()->Retain();
588  return SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
589                                              InstantiatedAssertExpr.get(),
590                                              Message.get());
591}
592
593Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
594  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
595                                    D->getLocation(), D->getIdentifier(),
596                                    D->getTagKeywordLoc(),
597                                    /*PrevDecl=*/0);
598  Enum->setInstantiationOfMemberEnum(D);
599  Enum->setAccess(D->getAccess());
600  if (SubstQualifier(D, Enum)) return 0;
601  Owner->addDecl(Enum);
602  Enum->startDefinition();
603
604  if (D->getDeclContext()->isFunctionOrMethod())
605    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
606
607  llvm::SmallVector<Decl*, 4> Enumerators;
608
609  EnumConstantDecl *LastEnumConst = 0;
610  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
611         ECEnd = D->enumerator_end();
612       EC != ECEnd; ++EC) {
613    // The specified value for the enumerator.
614    ExprResult Value = SemaRef.Owned((Expr *)0);
615    if (Expr *UninstValue = EC->getInitExpr()) {
616      // The enumerator's value expression is not potentially evaluated.
617      EnterExpressionEvaluationContext Unevaluated(SemaRef,
618                                                   Sema::Unevaluated);
619
620      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
621    }
622
623    // Drop the initial value and continue.
624    bool isInvalid = false;
625    if (Value.isInvalid()) {
626      Value = SemaRef.Owned((Expr *)0);
627      isInvalid = true;
628    }
629
630    EnumConstantDecl *EnumConst
631      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
632                                  EC->getLocation(), EC->getIdentifier(),
633                                  Value.get());
634
635    if (isInvalid) {
636      if (EnumConst)
637        EnumConst->setInvalidDecl();
638      Enum->setInvalidDecl();
639    }
640
641    if (EnumConst) {
642      EnumConst->setAccess(Enum->getAccess());
643      Enum->addDecl(EnumConst);
644      Enumerators.push_back(EnumConst);
645      LastEnumConst = EnumConst;
646
647      if (D->getDeclContext()->isFunctionOrMethod()) {
648        // If the enumeration is within a function or method, record the enum
649        // constant as a local.
650        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
651      }
652    }
653  }
654
655  // FIXME: Fixup LBraceLoc and RBraceLoc
656  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
657  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
658                        Enum,
659                        Enumerators.data(), Enumerators.size(),
660                        0, 0);
661
662  return Enum;
663}
664
665Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
666  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
667  return 0;
668}
669
670Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
671  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
672
673  // Create a local instantiation scope for this class template, which
674  // will contain the instantiations of the template parameters.
675  LocalInstantiationScope Scope(SemaRef);
676  TemplateParameterList *TempParams = D->getTemplateParameters();
677  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
678  if (!InstParams)
679    return NULL;
680
681  CXXRecordDecl *Pattern = D->getTemplatedDecl();
682
683  // Instantiate the qualifier.  We have to do this first in case
684  // we're a friend declaration, because if we are then we need to put
685  // the new declaration in the appropriate context.
686  NestedNameSpecifier *Qualifier = Pattern->getQualifier();
687  if (Qualifier) {
688    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
689                                                 Pattern->getQualifierRange(),
690                                                 TemplateArgs);
691    if (!Qualifier) return 0;
692  }
693
694  CXXRecordDecl *PrevDecl = 0;
695  ClassTemplateDecl *PrevClassTemplate = 0;
696
697  // If this isn't a friend, then it's a member template, in which
698  // case we just want to build the instantiation in the
699  // specialization.  If it is a friend, we want to build it in
700  // the appropriate context.
701  DeclContext *DC = Owner;
702  if (isFriend) {
703    if (Qualifier) {
704      CXXScopeSpec SS;
705      SS.setScopeRep(Qualifier);
706      SS.setRange(Pattern->getQualifierRange());
707      DC = SemaRef.computeDeclContext(SS);
708      if (!DC) return 0;
709    } else {
710      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
711                                           Pattern->getDeclContext(),
712                                           TemplateArgs);
713    }
714
715    // Look for a previous declaration of the template in the owning
716    // context.
717    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
718                   Sema::LookupOrdinaryName, Sema::ForRedeclaration);
719    SemaRef.LookupQualifiedName(R, DC);
720
721    if (R.isSingleResult()) {
722      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
723      if (PrevClassTemplate)
724        PrevDecl = PrevClassTemplate->getTemplatedDecl();
725    }
726
727    if (!PrevClassTemplate && Qualifier) {
728      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
729        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
730        << Pattern->getQualifierRange();
731      return 0;
732    }
733
734    bool AdoptedPreviousTemplateParams = false;
735    if (PrevClassTemplate) {
736      bool Complain = true;
737
738      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
739      // template for struct std::tr1::__detail::_Map_base, where the
740      // template parameters of the friend declaration don't match the
741      // template parameters of the original declaration. In this one
742      // case, we don't complain about the ill-formed friend
743      // declaration.
744      if (isFriend && Pattern->getIdentifier() &&
745          Pattern->getIdentifier()->isStr("_Map_base") &&
746          DC->isNamespace() &&
747          cast<NamespaceDecl>(DC)->getIdentifier() &&
748          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
749        DeclContext *DCParent = DC->getParent();
750        if (DCParent->isNamespace() &&
751            cast<NamespaceDecl>(DCParent)->getIdentifier() &&
752            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
753          DeclContext *DCParent2 = DCParent->getParent();
754          if (DCParent2->isNamespace() &&
755              cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
756              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
757              DCParent2->getParent()->isTranslationUnit())
758            Complain = false;
759        }
760      }
761
762      TemplateParameterList *PrevParams
763        = PrevClassTemplate->getTemplateParameters();
764
765      // Make sure the parameter lists match.
766      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
767                                                  Complain,
768                                                  Sema::TPL_TemplateMatch)) {
769        if (Complain)
770          return 0;
771
772        AdoptedPreviousTemplateParams = true;
773        InstParams = PrevParams;
774      }
775
776      // Do some additional validation, then merge default arguments
777      // from the existing declarations.
778      if (!AdoptedPreviousTemplateParams &&
779          SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
780                                             Sema::TPC_ClassTemplate))
781        return 0;
782    }
783  }
784
785  CXXRecordDecl *RecordInst
786    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
787                            Pattern->getLocation(), Pattern->getIdentifier(),
788                            Pattern->getTagKeywordLoc(), PrevDecl,
789                            /*DelayTypeCreation=*/true);
790
791  if (Qualifier)
792    RecordInst->setQualifierInfo(Qualifier, Pattern->getQualifierRange());
793
794  ClassTemplateDecl *Inst
795    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
796                                D->getIdentifier(), InstParams, RecordInst,
797                                PrevClassTemplate);
798  RecordInst->setDescribedClassTemplate(Inst);
799
800  if (isFriend) {
801    if (PrevClassTemplate)
802      Inst->setAccess(PrevClassTemplate->getAccess());
803    else
804      Inst->setAccess(D->getAccess());
805
806    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
807    // TODO: do we want to track the instantiation progeny of this
808    // friend target decl?
809  } else {
810    Inst->setAccess(D->getAccess());
811    Inst->setInstantiatedFromMemberTemplate(D);
812  }
813
814  // Trigger creation of the type for the instantiation.
815  SemaRef.Context.getInjectedClassNameType(RecordInst,
816                                    Inst->getInjectedClassNameSpecialization());
817
818  // Finish handling of friends.
819  if (isFriend) {
820    DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
821    return Inst;
822  }
823
824  Owner->addDecl(Inst);
825
826  // Instantiate all of the partial specializations of this member class
827  // template.
828  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
829  D->getPartialSpecializations(PartialSpecs);
830  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
831    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
832
833  return Inst;
834}
835
836Decl *
837TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
838                                   ClassTemplatePartialSpecializationDecl *D) {
839  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
840
841  // Lookup the already-instantiated declaration in the instantiation
842  // of the class template and return that.
843  DeclContext::lookup_result Found
844    = Owner->lookup(ClassTemplate->getDeclName());
845  if (Found.first == Found.second)
846    return 0;
847
848  ClassTemplateDecl *InstClassTemplate
849    = dyn_cast<ClassTemplateDecl>(*Found.first);
850  if (!InstClassTemplate)
851    return 0;
852
853  return InstClassTemplate->findPartialSpecInstantiatedFromMember(D);
854}
855
856Decl *
857TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
858  // Create a local instantiation scope for this function template, which
859  // will contain the instantiations of the template parameters and then get
860  // merged with the local instantiation scope for the function template
861  // itself.
862  LocalInstantiationScope Scope(SemaRef);
863
864  TemplateParameterList *TempParams = D->getTemplateParameters();
865  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
866  if (!InstParams)
867    return NULL;
868
869  FunctionDecl *Instantiated = 0;
870  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
871    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
872                                                                 InstParams));
873  else
874    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
875                                                          D->getTemplatedDecl(),
876                                                                InstParams));
877
878  if (!Instantiated)
879    return 0;
880
881  Instantiated->setAccess(D->getAccess());
882
883  // Link the instantiated function template declaration to the function
884  // template from which it was instantiated.
885  FunctionTemplateDecl *InstTemplate
886    = Instantiated->getDescribedFunctionTemplate();
887  InstTemplate->setAccess(D->getAccess());
888  assert(InstTemplate &&
889         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
890
891  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
892
893  // Link the instantiation back to the pattern *unless* this is a
894  // non-definition friend declaration.
895  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
896      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
897    InstTemplate->setInstantiatedFromMemberTemplate(D);
898
899  // Make declarations visible in the appropriate context.
900  if (!isFriend)
901    Owner->addDecl(InstTemplate);
902
903  return InstTemplate;
904}
905
906Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
907  CXXRecordDecl *PrevDecl = 0;
908  if (D->isInjectedClassName())
909    PrevDecl = cast<CXXRecordDecl>(Owner);
910  else if (D->getPreviousDeclaration()) {
911    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
912                                                   D->getPreviousDeclaration(),
913                                                   TemplateArgs);
914    if (!Prev) return 0;
915    PrevDecl = cast<CXXRecordDecl>(Prev);
916  }
917
918  CXXRecordDecl *Record
919    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
920                            D->getLocation(), D->getIdentifier(),
921                            D->getTagKeywordLoc(), PrevDecl);
922
923  // Substitute the nested name specifier, if any.
924  if (SubstQualifier(D, Record))
925    return 0;
926
927  Record->setImplicit(D->isImplicit());
928  // FIXME: Check against AS_none is an ugly hack to work around the issue that
929  // the tag decls introduced by friend class declarations don't have an access
930  // specifier. Remove once this area of the code gets sorted out.
931  if (D->getAccess() != AS_none)
932    Record->setAccess(D->getAccess());
933  if (!D->isInjectedClassName())
934    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
935
936  // If the original function was part of a friend declaration,
937  // inherit its namespace state.
938  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
939    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
940
941  // Make sure that anonymous structs and unions are recorded.
942  if (D->isAnonymousStructOrUnion()) {
943    Record->setAnonymousStructOrUnion(true);
944    if (Record->getDeclContext()->getRedeclContext()->isFunctionOrMethod())
945      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
946  }
947
948  Owner->addDecl(Record);
949  return Record;
950}
951
952/// Normal class members are of more specific types and therefore
953/// don't make it here.  This function serves two purposes:
954///   1) instantiating function templates
955///   2) substituting friend declarations
956/// FIXME: preserve function definitions in case #2
957Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
958                                       TemplateParameterList *TemplateParams) {
959  // Check whether there is already a function template specialization for
960  // this declaration.
961  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
962  void *InsertPos = 0;
963  if (FunctionTemplate && !TemplateParams) {
964    std::pair<const TemplateArgument *, unsigned> Innermost
965      = TemplateArgs.getInnermost();
966
967    FunctionDecl *SpecFunc
968      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
969                                             InsertPos);
970
971    // If we already have a function template specialization, return it.
972    if (SpecFunc)
973      return SpecFunc;
974  }
975
976  bool isFriend;
977  if (FunctionTemplate)
978    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
979  else
980    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
981
982  bool MergeWithParentScope = (TemplateParams != 0) ||
983    Owner->isFunctionOrMethod() ||
984    !(isa<Decl>(Owner) &&
985      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
986  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
987
988  llvm::SmallVector<ParmVarDecl *, 4> Params;
989  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
990  TInfo = SubstFunctionType(D, Params);
991  if (!TInfo)
992    return 0;
993  QualType T = TInfo->getType();
994
995  NestedNameSpecifier *Qualifier = D->getQualifier();
996  if (Qualifier) {
997    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
998                                                 D->getQualifierRange(),
999                                                 TemplateArgs);
1000    if (!Qualifier) return 0;
1001  }
1002
1003  // If we're instantiating a local function declaration, put the result
1004  // in the owner;  otherwise we need to find the instantiated context.
1005  DeclContext *DC;
1006  if (D->getDeclContext()->isFunctionOrMethod())
1007    DC = Owner;
1008  else if (isFriend && Qualifier) {
1009    CXXScopeSpec SS;
1010    SS.setScopeRep(Qualifier);
1011    SS.setRange(D->getQualifierRange());
1012    DC = SemaRef.computeDeclContext(SS);
1013    if (!DC) return 0;
1014  } else {
1015    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1016                                         TemplateArgs);
1017  }
1018
1019  FunctionDecl *Function =
1020      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
1021                           D->getDeclName(), T, TInfo,
1022                           D->getStorageClass(), D->getStorageClassAsWritten(),
1023                           D->isInlineSpecified(), D->hasWrittenPrototype());
1024
1025  if (Qualifier)
1026    Function->setQualifierInfo(Qualifier, D->getQualifierRange());
1027
1028  DeclContext *LexicalDC = Owner;
1029  if (!isFriend && D->isOutOfLine()) {
1030    assert(D->getDeclContext()->isFileContext());
1031    LexicalDC = D->getDeclContext();
1032  }
1033
1034  Function->setLexicalDeclContext(LexicalDC);
1035
1036  // Attach the parameters
1037  for (unsigned P = 0; P < Params.size(); ++P)
1038    if (Params[P])
1039      Params[P]->setOwningFunction(Function);
1040  Function->setParams(Params.data(), Params.size());
1041
1042  SourceLocation InstantiateAtPOI;
1043  if (TemplateParams) {
1044    // Our resulting instantiation is actually a function template, since we
1045    // are substituting only the outer template parameters. For example, given
1046    //
1047    //   template<typename T>
1048    //   struct X {
1049    //     template<typename U> friend void f(T, U);
1050    //   };
1051    //
1052    //   X<int> x;
1053    //
1054    // We are instantiating the friend function template "f" within X<int>,
1055    // which means substituting int for T, but leaving "f" as a friend function
1056    // template.
1057    // Build the function template itself.
1058    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1059                                                    Function->getLocation(),
1060                                                    Function->getDeclName(),
1061                                                    TemplateParams, Function);
1062    Function->setDescribedFunctionTemplate(FunctionTemplate);
1063
1064    FunctionTemplate->setLexicalDeclContext(LexicalDC);
1065
1066    if (isFriend && D->isThisDeclarationADefinition()) {
1067      // TODO: should we remember this connection regardless of whether
1068      // the friend declaration provided a body?
1069      FunctionTemplate->setInstantiatedFromMemberTemplate(
1070                                           D->getDescribedFunctionTemplate());
1071    }
1072  } else if (FunctionTemplate) {
1073    // Record this function template specialization.
1074    std::pair<const TemplateArgument *, unsigned> Innermost
1075      = TemplateArgs.getInnermost();
1076    Function->setFunctionTemplateSpecialization(FunctionTemplate,
1077                  new (SemaRef.Context) TemplateArgumentList(SemaRef.Context,
1078                                                             Innermost.first,
1079                                                             Innermost.second),
1080                                                InsertPos);
1081  } else if (isFriend && D->isThisDeclarationADefinition()) {
1082    // TODO: should we remember this connection regardless of whether
1083    // the friend declaration provided a body?
1084    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1085  }
1086
1087  if (InitFunctionInstantiation(Function, D))
1088    Function->setInvalidDecl();
1089
1090  bool Redeclaration = false;
1091  bool OverloadableAttrRequired = false;
1092  bool isExplicitSpecialization = false;
1093
1094  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1095                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1096
1097  if (DependentFunctionTemplateSpecializationInfo *Info
1098        = D->getDependentSpecializationInfo()) {
1099    assert(isFriend && "non-friend has dependent specialization info?");
1100
1101    // This needs to be set now for future sanity.
1102    Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1103
1104    // Instantiate the explicit template arguments.
1105    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1106                                          Info->getRAngleLoc());
1107    for (unsigned I = 0, E = Info->getNumTemplateArgs(); I != E; ++I) {
1108      TemplateArgumentLoc Loc;
1109      if (SemaRef.Subst(Info->getTemplateArg(I), Loc, TemplateArgs))
1110        return 0;
1111
1112      ExplicitArgs.addArgument(Loc);
1113    }
1114
1115    // Map the candidate templates to their instantiations.
1116    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1117      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1118                                                Info->getTemplate(I),
1119                                                TemplateArgs);
1120      if (!Temp) return 0;
1121
1122      Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1123    }
1124
1125    if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1126                                                    &ExplicitArgs,
1127                                                    Previous))
1128      Function->setInvalidDecl();
1129
1130    isExplicitSpecialization = true;
1131
1132  } else if (TemplateParams || !FunctionTemplate) {
1133    // Look only into the namespace where the friend would be declared to
1134    // find a previous declaration. This is the innermost enclosing namespace,
1135    // as described in ActOnFriendFunctionDecl.
1136    SemaRef.LookupQualifiedName(Previous, DC);
1137
1138    // In C++, the previous declaration we find might be a tag type
1139    // (class or enum). In this case, the new declaration will hide the
1140    // tag type. Note that this does does not apply if we're declaring a
1141    // typedef (C++ [dcl.typedef]p4).
1142    if (Previous.isSingleTagDecl())
1143      Previous.clear();
1144  }
1145
1146  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1147                                   isExplicitSpecialization, Redeclaration,
1148                                   /*FIXME:*/OverloadableAttrRequired);
1149
1150  NamedDecl *PrincipalDecl = (TemplateParams
1151                              ? cast<NamedDecl>(FunctionTemplate)
1152                              : Function);
1153
1154  // If the original function was part of a friend declaration,
1155  // inherit its namespace state and add it to the owner.
1156  if (isFriend) {
1157    NamedDecl *PrevDecl;
1158    if (TemplateParams)
1159      PrevDecl = FunctionTemplate->getPreviousDeclaration();
1160    else
1161      PrevDecl = Function->getPreviousDeclaration();
1162
1163    PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0);
1164    DC->makeDeclVisibleInContext(PrincipalDecl, /*Recoverable=*/ false);
1165
1166    bool queuedInstantiation = false;
1167
1168    if (!SemaRef.getLangOptions().CPlusPlus0x &&
1169        D->isThisDeclarationADefinition()) {
1170      // Check for a function body.
1171      const FunctionDecl *Definition = 0;
1172      if (Function->hasBody(Definition) &&
1173          Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1174        SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1175          << Function->getDeclName();
1176        SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1177        Function->setInvalidDecl();
1178      }
1179      // Check for redefinitions due to other instantiations of this or
1180      // a similar friend function.
1181      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1182                                           REnd = Function->redecls_end();
1183                R != REnd; ++R) {
1184        if (*R == Function)
1185          continue;
1186        switch (R->getFriendObjectKind()) {
1187        case Decl::FOK_None:
1188          if (!queuedInstantiation && R->isUsed(false)) {
1189            if (MemberSpecializationInfo *MSInfo
1190                = Function->getMemberSpecializationInfo()) {
1191              if (MSInfo->getPointOfInstantiation().isInvalid()) {
1192                SourceLocation Loc = R->getLocation(); // FIXME
1193                MSInfo->setPointOfInstantiation(Loc);
1194                SemaRef.PendingLocalImplicitInstantiations.push_back(
1195                                                 std::make_pair(Function, Loc));
1196                queuedInstantiation = true;
1197              }
1198            }
1199          }
1200          break;
1201        default:
1202          if (const FunctionDecl *RPattern
1203              = R->getTemplateInstantiationPattern())
1204            if (RPattern->hasBody(RPattern)) {
1205              SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1206                << Function->getDeclName();
1207              SemaRef.Diag(R->getLocation(), diag::note_previous_definition);
1208              Function->setInvalidDecl();
1209              break;
1210            }
1211        }
1212      }
1213    }
1214  }
1215
1216  if (Function->isOverloadedOperator() && !DC->isRecord() &&
1217      PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1218    PrincipalDecl->setNonMemberOperator();
1219
1220  return Function;
1221}
1222
1223Decl *
1224TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1225                                      TemplateParameterList *TemplateParams) {
1226  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1227  void *InsertPos = 0;
1228  if (FunctionTemplate && !TemplateParams) {
1229    // We are creating a function template specialization from a function
1230    // template. Check whether there is already a function template
1231    // specialization for this particular set of template arguments.
1232    std::pair<const TemplateArgument *, unsigned> Innermost
1233      = TemplateArgs.getInnermost();
1234
1235    FunctionDecl *SpecFunc
1236      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
1237                                             InsertPos);
1238
1239    // If we already have a function template specialization, return it.
1240    if (SpecFunc)
1241      return SpecFunc;
1242  }
1243
1244  bool isFriend;
1245  if (FunctionTemplate)
1246    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1247  else
1248    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1249
1250  bool MergeWithParentScope = (TemplateParams != 0) ||
1251    !(isa<Decl>(Owner) &&
1252      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1253  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1254
1255  llvm::SmallVector<ParmVarDecl *, 4> Params;
1256  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1257  TInfo = SubstFunctionType(D, Params);
1258  if (!TInfo)
1259    return 0;
1260  QualType T = TInfo->getType();
1261
1262  // \brief If the type of this function is not *directly* a function
1263  // type, then we're instantiating the a function that was declared
1264  // via a typedef, e.g.,
1265  //
1266  //   typedef int functype(int, int);
1267  //   functype func;
1268  //
1269  // In this case, we'll just go instantiate the ParmVarDecls that we
1270  // synthesized in the method declaration.
1271  if (!isa<FunctionProtoType>(T)) {
1272    assert(!Params.size() && "Instantiating type could not yield parameters");
1273    for (unsigned I = 0, N = D->getNumParams(); I != N; ++I) {
1274      ParmVarDecl *P = SemaRef.SubstParmVarDecl(D->getParamDecl(I),
1275                                                TemplateArgs);
1276      if (!P)
1277        return 0;
1278
1279      Params.push_back(P);
1280    }
1281  }
1282
1283  NestedNameSpecifier *Qualifier = D->getQualifier();
1284  if (Qualifier) {
1285    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1286                                                 D->getQualifierRange(),
1287                                                 TemplateArgs);
1288    if (!Qualifier) return 0;
1289  }
1290
1291  DeclContext *DC = Owner;
1292  if (isFriend) {
1293    if (Qualifier) {
1294      CXXScopeSpec SS;
1295      SS.setScopeRep(Qualifier);
1296      SS.setRange(D->getQualifierRange());
1297      DC = SemaRef.computeDeclContext(SS);
1298    } else {
1299      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1300                                           D->getDeclContext(),
1301                                           TemplateArgs);
1302    }
1303    if (!DC) return 0;
1304  }
1305
1306  // Build the instantiated method declaration.
1307  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1308  CXXMethodDecl *Method = 0;
1309
1310  DeclarationNameInfo NameInfo
1311    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1312  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1313    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1314                                        NameInfo, T, TInfo,
1315                                        Constructor->isExplicit(),
1316                                        Constructor->isInlineSpecified(),
1317                                        false);
1318  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1319    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1320                                       NameInfo, T,
1321                                       Destructor->isInlineSpecified(),
1322                                       false);
1323  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1324    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1325                                       NameInfo, T, TInfo,
1326                                       Conversion->isInlineSpecified(),
1327                                       Conversion->isExplicit());
1328  } else {
1329    Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1330                                   NameInfo, T, TInfo,
1331                                   D->isStatic(),
1332                                   D->getStorageClassAsWritten(),
1333                                   D->isInlineSpecified());
1334  }
1335
1336  if (Qualifier)
1337    Method->setQualifierInfo(Qualifier, D->getQualifierRange());
1338
1339  if (TemplateParams) {
1340    // Our resulting instantiation is actually a function template, since we
1341    // are substituting only the outer template parameters. For example, given
1342    //
1343    //   template<typename T>
1344    //   struct X {
1345    //     template<typename U> void f(T, U);
1346    //   };
1347    //
1348    //   X<int> x;
1349    //
1350    // We are instantiating the member template "f" within X<int>, which means
1351    // substituting int for T, but leaving "f" as a member function template.
1352    // Build the function template itself.
1353    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1354                                                    Method->getLocation(),
1355                                                    Method->getDeclName(),
1356                                                    TemplateParams, Method);
1357    if (isFriend) {
1358      FunctionTemplate->setLexicalDeclContext(Owner);
1359      FunctionTemplate->setObjectOfFriendDecl(true);
1360    } else if (D->isOutOfLine())
1361      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1362    Method->setDescribedFunctionTemplate(FunctionTemplate);
1363  } else if (FunctionTemplate) {
1364    // Record this function template specialization.
1365    std::pair<const TemplateArgument *, unsigned> Innermost
1366      = TemplateArgs.getInnermost();
1367    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1368                    new (SemaRef.Context) TemplateArgumentList(SemaRef.Context,
1369                                                              Innermost.first,
1370                                                              Innermost.second),
1371                                              InsertPos);
1372  } else if (!isFriend) {
1373    // Record that this is an instantiation of a member function.
1374    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1375  }
1376
1377  // If we are instantiating a member function defined
1378  // out-of-line, the instantiation will have the same lexical
1379  // context (which will be a namespace scope) as the template.
1380  if (isFriend) {
1381    Method->setLexicalDeclContext(Owner);
1382    Method->setObjectOfFriendDecl(true);
1383  } else if (D->isOutOfLine())
1384    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1385
1386  // Attach the parameters
1387  for (unsigned P = 0; P < Params.size(); ++P)
1388    Params[P]->setOwningFunction(Method);
1389  Method->setParams(Params.data(), Params.size());
1390
1391  if (InitMethodInstantiation(Method, D))
1392    Method->setInvalidDecl();
1393
1394  LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
1395                        Sema::ForRedeclaration);
1396
1397  if (!FunctionTemplate || TemplateParams || isFriend) {
1398    SemaRef.LookupQualifiedName(Previous, Record);
1399
1400    // In C++, the previous declaration we find might be a tag type
1401    // (class or enum). In this case, the new declaration will hide the
1402    // tag type. Note that this does does not apply if we're declaring a
1403    // typedef (C++ [dcl.typedef]p4).
1404    if (Previous.isSingleTagDecl())
1405      Previous.clear();
1406  }
1407
1408  bool Redeclaration = false;
1409  bool OverloadableAttrRequired = false;
1410  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1411                                   /*FIXME:*/OverloadableAttrRequired);
1412
1413  if (D->isPure())
1414    SemaRef.CheckPureMethod(Method, SourceRange());
1415
1416  Method->setAccess(D->getAccess());
1417
1418  if (FunctionTemplate) {
1419    // If there's a function template, let our caller handle it.
1420  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1421    // Don't hide a (potentially) valid declaration with an invalid one.
1422  } else {
1423    NamedDecl *DeclToAdd = (TemplateParams
1424                            ? cast<NamedDecl>(FunctionTemplate)
1425                            : Method);
1426    if (isFriend)
1427      Record->makeDeclVisibleInContext(DeclToAdd);
1428    else
1429      Owner->addDecl(DeclToAdd);
1430  }
1431
1432  return Method;
1433}
1434
1435Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1436  return VisitCXXMethodDecl(D);
1437}
1438
1439Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1440  return VisitCXXMethodDecl(D);
1441}
1442
1443Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1444  return VisitCXXMethodDecl(D);
1445}
1446
1447ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1448  return SemaRef.SubstParmVarDecl(D, TemplateArgs);
1449}
1450
1451Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1452                                                    TemplateTypeParmDecl *D) {
1453  // TODO: don't always clone when decls are refcounted.
1454  const Type* T = D->getTypeForDecl();
1455  assert(T->isTemplateTypeParmType());
1456  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1457
1458  TemplateTypeParmDecl *Inst =
1459    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1460                                 TTPT->getDepth() - TemplateArgs.getNumLevels(),
1461                                 TTPT->getIndex(),TTPT->getName(),
1462                                 D->wasDeclaredWithTypename(),
1463                                 D->isParameterPack());
1464
1465  if (D->hasDefaultArgument())
1466    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1467
1468  // Introduce this template parameter's instantiation into the instantiation
1469  // scope.
1470  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1471
1472  return Inst;
1473}
1474
1475Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1476                                                 NonTypeTemplateParmDecl *D) {
1477  // Substitute into the type of the non-type template parameter.
1478  QualType T;
1479  TypeSourceInfo *DI = D->getTypeSourceInfo();
1480  if (DI) {
1481    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1482                           D->getDeclName());
1483    if (DI) T = DI->getType();
1484  } else {
1485    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1486                          D->getDeclName());
1487    DI = 0;
1488  }
1489  if (T.isNull())
1490    return 0;
1491
1492  // Check that this type is acceptable for a non-type template parameter.
1493  bool Invalid = false;
1494  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1495  if (T.isNull()) {
1496    T = SemaRef.Context.IntTy;
1497    Invalid = true;
1498  }
1499
1500  NonTypeTemplateParmDecl *Param
1501    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1502                                    D->getDepth() - TemplateArgs.getNumLevels(),
1503                                      D->getPosition(), D->getIdentifier(), T,
1504                                      DI);
1505  if (Invalid)
1506    Param->setInvalidDecl();
1507
1508  Param->setDefaultArgument(D->getDefaultArgument(), false);
1509
1510  // Introduce this template parameter's instantiation into the instantiation
1511  // scope.
1512  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1513  return Param;
1514}
1515
1516Decl *
1517TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1518                                                  TemplateTemplateParmDecl *D) {
1519  // Instantiate the template parameter list of the template template parameter.
1520  TemplateParameterList *TempParams = D->getTemplateParameters();
1521  TemplateParameterList *InstParams;
1522  {
1523    // Perform the actual substitution of template parameters within a new,
1524    // local instantiation scope.
1525    LocalInstantiationScope Scope(SemaRef);
1526    InstParams = SubstTemplateParams(TempParams);
1527    if (!InstParams)
1528      return NULL;
1529  }
1530
1531  // Build the template template parameter.
1532  TemplateTemplateParmDecl *Param
1533    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1534                                   D->getDepth() - TemplateArgs.getNumLevels(),
1535                                       D->getPosition(), D->getIdentifier(),
1536                                       InstParams);
1537  Param->setDefaultArgument(D->getDefaultArgument(), false);
1538
1539  // Introduce this template parameter's instantiation into the instantiation
1540  // scope.
1541  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1542
1543  return Param;
1544}
1545
1546Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1547  // Using directives are never dependent, so they require no explicit
1548
1549  UsingDirectiveDecl *Inst
1550    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1551                                 D->getNamespaceKeyLocation(),
1552                                 D->getQualifierRange(), D->getQualifier(),
1553                                 D->getIdentLocation(),
1554                                 D->getNominatedNamespace(),
1555                                 D->getCommonAncestor());
1556  Owner->addDecl(Inst);
1557  return Inst;
1558}
1559
1560Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1561
1562  // The nested name specifier may be dependent, for example
1563  //     template <typename T> struct t {
1564  //       struct s1 { T f1(); };
1565  //       struct s2 : s1 { using s1::f1; };
1566  //     };
1567  //     template struct t<int>;
1568  // Here, in using s1::f1, s1 refers to t<T>::s1;
1569  // we need to substitute for t<int>::s1.
1570  NestedNameSpecifier *NNS =
1571      SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameDecl(),
1572      D->getNestedNameRange(),
1573      TemplateArgs);
1574  if (!NNS)
1575      return 0;
1576
1577  // The name info is non-dependent, so no transformation
1578  // is required.
1579  DeclarationNameInfo NameInfo = D->getNameInfo();
1580
1581  // We only need to do redeclaration lookups if we're in a class
1582  // scope (in fact, it's not really even possible in non-class
1583  // scopes).
1584  bool CheckRedeclaration = Owner->isRecord();
1585
1586  LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
1587                    Sema::ForRedeclaration);
1588
1589  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1590                                       D->getNestedNameRange(),
1591                                       D->getUsingLocation(),
1592                                       NNS,
1593                                       NameInfo,
1594                                       D->isTypeName());
1595
1596  CXXScopeSpec SS;
1597  SS.setScopeRep(NNS);
1598  SS.setRange(D->getNestedNameRange());
1599
1600  if (CheckRedeclaration) {
1601    Prev.setHideTags(false);
1602    SemaRef.LookupQualifiedName(Prev, Owner);
1603
1604    // Check for invalid redeclarations.
1605    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1606                                            D->isTypeName(), SS,
1607                                            D->getLocation(), Prev))
1608      NewUD->setInvalidDecl();
1609
1610  }
1611
1612  if (!NewUD->isInvalidDecl() &&
1613      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1614                                      D->getLocation()))
1615    NewUD->setInvalidDecl();
1616
1617  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1618  NewUD->setAccess(D->getAccess());
1619  Owner->addDecl(NewUD);
1620
1621  // Don't process the shadow decls for an invalid decl.
1622  if (NewUD->isInvalidDecl())
1623    return NewUD;
1624
1625  bool isFunctionScope = Owner->isFunctionOrMethod();
1626
1627  // Process the shadow decls.
1628  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1629         I != E; ++I) {
1630    UsingShadowDecl *Shadow = *I;
1631    NamedDecl *InstTarget =
1632      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1633                                                   Shadow->getTargetDecl(),
1634                                                   TemplateArgs));
1635
1636    if (CheckRedeclaration &&
1637        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1638      continue;
1639
1640    UsingShadowDecl *InstShadow
1641      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1642    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1643
1644    if (isFunctionScope)
1645      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1646  }
1647
1648  return NewUD;
1649}
1650
1651Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1652  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1653  return 0;
1654}
1655
1656Decl * TemplateDeclInstantiator
1657    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1658  NestedNameSpecifier *NNS =
1659    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1660                                     D->getTargetNestedNameRange(),
1661                                     TemplateArgs);
1662  if (!NNS)
1663    return 0;
1664
1665  CXXScopeSpec SS;
1666  SS.setRange(D->getTargetNestedNameRange());
1667  SS.setScopeRep(NNS);
1668
1669  // Since NameInfo refers to a typename, it cannot be a C++ special name.
1670  // Hence, no tranformation is required for it.
1671  DeclarationNameInfo NameInfo(D->getDeclName(), D->getLocation());
1672  NamedDecl *UD =
1673    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1674                                  D->getUsingLoc(), SS, NameInfo, 0,
1675                                  /*instantiation*/ true,
1676                                  /*typename*/ true, D->getTypenameLoc());
1677  if (UD)
1678    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1679
1680  return UD;
1681}
1682
1683Decl * TemplateDeclInstantiator
1684    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1685  NestedNameSpecifier *NNS =
1686    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1687                                     D->getTargetNestedNameRange(),
1688                                     TemplateArgs);
1689  if (!NNS)
1690    return 0;
1691
1692  CXXScopeSpec SS;
1693  SS.setRange(D->getTargetNestedNameRange());
1694  SS.setScopeRep(NNS);
1695
1696  DeclarationNameInfo NameInfo
1697    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1698
1699  NamedDecl *UD =
1700    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1701                                  D->getUsingLoc(), SS, NameInfo, 0,
1702                                  /*instantiation*/ true,
1703                                  /*typename*/ false, SourceLocation());
1704  if (UD)
1705    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1706
1707  return UD;
1708}
1709
1710Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1711                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1712  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1713  if (D->isInvalidDecl())
1714    return 0;
1715
1716  return Instantiator.Visit(D);
1717}
1718
1719/// \brief Instantiates a nested template parameter list in the current
1720/// instantiation context.
1721///
1722/// \param L The parameter list to instantiate
1723///
1724/// \returns NULL if there was an error
1725TemplateParameterList *
1726TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1727  // Get errors for all the parameters before bailing out.
1728  bool Invalid = false;
1729
1730  unsigned N = L->size();
1731  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1732  ParamVector Params;
1733  Params.reserve(N);
1734  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1735       PI != PE; ++PI) {
1736    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1737    Params.push_back(D);
1738    Invalid = Invalid || !D || D->isInvalidDecl();
1739  }
1740
1741  // Clean up if we had an error.
1742  if (Invalid)
1743    return NULL;
1744
1745  TemplateParameterList *InstL
1746    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1747                                    L->getLAngleLoc(), &Params.front(), N,
1748                                    L->getRAngleLoc());
1749  return InstL;
1750}
1751
1752/// \brief Instantiate the declaration of a class template partial
1753/// specialization.
1754///
1755/// \param ClassTemplate the (instantiated) class template that is partially
1756// specialized by the instantiation of \p PartialSpec.
1757///
1758/// \param PartialSpec the (uninstantiated) class template partial
1759/// specialization that we are instantiating.
1760///
1761/// \returns true if there was an error, false otherwise.
1762bool
1763TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1764                                            ClassTemplateDecl *ClassTemplate,
1765                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1766  // Create a local instantiation scope for this class template partial
1767  // specialization, which will contain the instantiations of the template
1768  // parameters.
1769  LocalInstantiationScope Scope(SemaRef);
1770
1771  // Substitute into the template parameters of the class template partial
1772  // specialization.
1773  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1774  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1775  if (!InstParams)
1776    return true;
1777
1778  // Substitute into the template arguments of the class template partial
1779  // specialization.
1780  const TemplateArgumentLoc *PartialSpecTemplateArgs
1781    = PartialSpec->getTemplateArgsAsWritten();
1782  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1783
1784  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1785  for (unsigned I = 0; I != N; ++I) {
1786    TemplateArgumentLoc Loc;
1787    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1788      return true;
1789    InstTemplateArgs.addArgument(Loc);
1790  }
1791
1792
1793  // Check that the template argument list is well-formed for this
1794  // class template.
1795  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1796                                        InstTemplateArgs.size());
1797  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1798                                        PartialSpec->getLocation(),
1799                                        InstTemplateArgs,
1800                                        false,
1801                                        Converted))
1802    return true;
1803
1804  // Figure out where to insert this class template partial specialization
1805  // in the member template's set of class template partial specializations.
1806  void *InsertPos = 0;
1807  ClassTemplateSpecializationDecl *PrevDecl
1808    = ClassTemplate->findPartialSpecialization(Converted.getFlatArguments(),
1809                                                Converted.flatSize(), InsertPos);
1810
1811  // Build the canonical type that describes the converted template
1812  // arguments of the class template partial specialization.
1813  QualType CanonType
1814    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1815                                                  Converted.getFlatArguments(),
1816                                                    Converted.flatSize());
1817
1818  // Build the fully-sugared type for this class template
1819  // specialization as the user wrote in the specialization
1820  // itself. This means that we'll pretty-print the type retrieved
1821  // from the specialization's declaration the way that the user
1822  // actually wrote the specialization, rather than formatting the
1823  // name based on the "canonical" representation used to store the
1824  // template arguments in the specialization.
1825  TypeSourceInfo *WrittenTy
1826    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1827                                                    TemplateName(ClassTemplate),
1828                                                    PartialSpec->getLocation(),
1829                                                    InstTemplateArgs,
1830                                                    CanonType);
1831
1832  if (PrevDecl) {
1833    // We've already seen a partial specialization with the same template
1834    // parameters and template arguments. This can happen, for example, when
1835    // substituting the outer template arguments ends up causing two
1836    // class template partial specializations of a member class template
1837    // to have identical forms, e.g.,
1838    //
1839    //   template<typename T, typename U>
1840    //   struct Outer {
1841    //     template<typename X, typename Y> struct Inner;
1842    //     template<typename Y> struct Inner<T, Y>;
1843    //     template<typename Y> struct Inner<U, Y>;
1844    //   };
1845    //
1846    //   Outer<int, int> outer; // error: the partial specializations of Inner
1847    //                          // have the same signature.
1848    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1849      << WrittenTy;
1850    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1851      << SemaRef.Context.getTypeDeclType(PrevDecl);
1852    return true;
1853  }
1854
1855
1856  // Create the class template partial specialization declaration.
1857  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1858    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
1859                                                     PartialSpec->getTagKind(),
1860                                                     Owner,
1861                                                     PartialSpec->getLocation(),
1862                                                     InstParams,
1863                                                     ClassTemplate,
1864                                                     Converted,
1865                                                     InstTemplateArgs,
1866                                                     CanonType,
1867                                                     0,
1868                             ClassTemplate->getNextPartialSpecSequenceNumber());
1869  // Substitute the nested name specifier, if any.
1870  if (SubstQualifier(PartialSpec, InstPartialSpec))
1871    return 0;
1872
1873  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1874  InstPartialSpec->setTypeAsWritten(WrittenTy);
1875
1876  // Add this partial specialization to the set of class template partial
1877  // specializations.
1878  ClassTemplate->AddPartialSpecialization(InstPartialSpec, InsertPos);
1879  return false;
1880}
1881
1882TypeSourceInfo*
1883TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1884                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1885  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1886  assert(OldTInfo && "substituting function without type source info");
1887  assert(Params.empty() && "parameter vector is non-empty at start");
1888  TypeSourceInfo *NewTInfo
1889    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
1890                                    D->getTypeSpecStartLoc(),
1891                                    D->getDeclName());
1892  if (!NewTInfo)
1893    return 0;
1894
1895  if (NewTInfo != OldTInfo) {
1896    // Get parameters from the new type info.
1897    TypeLoc OldTL = OldTInfo->getTypeLoc();
1898    if (FunctionProtoTypeLoc *OldProtoLoc
1899                                  = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1900      TypeLoc NewTL = NewTInfo->getTypeLoc();
1901      FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1902      assert(NewProtoLoc && "Missing prototype?");
1903      for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i) {
1904        // FIXME: Variadic templates will break this.
1905        Params.push_back(NewProtoLoc->getArg(i));
1906        SemaRef.CurrentInstantiationScope->InstantiatedLocal(
1907                                                        OldProtoLoc->getArg(i),
1908                                                        NewProtoLoc->getArg(i));
1909      }
1910    }
1911  } else {
1912    // The function type itself was not dependent and therefore no
1913    // substitution occurred. However, we still need to instantiate
1914    // the function parameters themselves.
1915    TypeLoc OldTL = OldTInfo->getTypeLoc();
1916    if (FunctionProtoTypeLoc *OldProtoLoc
1917                                    = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1918      for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
1919        ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
1920        if (!Parm)
1921          return 0;
1922        Params.push_back(Parm);
1923      }
1924    }
1925  }
1926  return NewTInfo;
1927}
1928
1929/// \brief Initializes the common fields of an instantiation function
1930/// declaration (New) from the corresponding fields of its template (Tmpl).
1931///
1932/// \returns true if there was an error
1933bool
1934TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1935                                                    FunctionDecl *Tmpl) {
1936  if (Tmpl->isDeleted())
1937    New->setDeleted();
1938
1939  // If we are performing substituting explicitly-specified template arguments
1940  // or deduced template arguments into a function template and we reach this
1941  // point, we are now past the point where SFINAE applies and have committed
1942  // to keeping the new function template specialization. We therefore
1943  // convert the active template instantiation for the function template
1944  // into a template instantiation for this specific function template
1945  // specialization, which is not a SFINAE context, so that we diagnose any
1946  // further errors in the declaration itself.
1947  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1948  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1949  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1950      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1951    if (FunctionTemplateDecl *FunTmpl
1952          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1953      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1954             "Deduction from the wrong function template?");
1955      (void) FunTmpl;
1956      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1957      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1958      --SemaRef.NonInstantiationEntries;
1959    }
1960  }
1961
1962  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1963  assert(Proto && "Function template without prototype?");
1964
1965  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1966      Proto->getNoReturnAttr()) {
1967    // The function has an exception specification or a "noreturn"
1968    // attribute. Substitute into each of the exception types.
1969    llvm::SmallVector<QualType, 4> Exceptions;
1970    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1971      // FIXME: Poor location information!
1972      QualType T
1973        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1974                            New->getLocation(), New->getDeclName());
1975      if (T.isNull() ||
1976          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1977        continue;
1978
1979      Exceptions.push_back(T);
1980    }
1981
1982    // Rebuild the function type
1983
1984    const FunctionProtoType *NewProto
1985      = New->getType()->getAs<FunctionProtoType>();
1986    assert(NewProto && "Template instantiation without function prototype?");
1987    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1988                                                 NewProto->arg_type_begin(),
1989                                                 NewProto->getNumArgs(),
1990                                                 NewProto->isVariadic(),
1991                                                 NewProto->getTypeQuals(),
1992                                                 Proto->hasExceptionSpec(),
1993                                                 Proto->hasAnyExceptionSpec(),
1994                                                 Exceptions.size(),
1995                                                 Exceptions.data(),
1996                                                 Proto->getExtInfo()));
1997  }
1998
1999  SemaRef.InstantiateAttrs(TemplateArgs, Tmpl, New);
2000
2001  return false;
2002}
2003
2004/// \brief Initializes common fields of an instantiated method
2005/// declaration (New) from the corresponding fields of its template
2006/// (Tmpl).
2007///
2008/// \returns true if there was an error
2009bool
2010TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
2011                                                  CXXMethodDecl *Tmpl) {
2012  if (InitFunctionInstantiation(New, Tmpl))
2013    return true;
2014
2015  New->setAccess(Tmpl->getAccess());
2016  if (Tmpl->isVirtualAsWritten())
2017    New->setVirtualAsWritten(true);
2018
2019  // FIXME: attributes
2020  // FIXME: New needs a pointer to Tmpl
2021  return false;
2022}
2023
2024/// \brief Instantiate the definition of the given function from its
2025/// template.
2026///
2027/// \param PointOfInstantiation the point at which the instantiation was
2028/// required. Note that this is not precisely a "point of instantiation"
2029/// for the function, but it's close.
2030///
2031/// \param Function the already-instantiated declaration of a
2032/// function template specialization or member function of a class template
2033/// specialization.
2034///
2035/// \param Recursive if true, recursively instantiates any functions that
2036/// are required by this instantiation.
2037///
2038/// \param DefinitionRequired if true, then we are performing an explicit
2039/// instantiation where the body of the function is required. Complain if
2040/// there is no such body.
2041void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
2042                                         FunctionDecl *Function,
2043                                         bool Recursive,
2044                                         bool DefinitionRequired) {
2045  if (Function->isInvalidDecl() || Function->hasBody())
2046    return;
2047
2048  // Never instantiate an explicit specialization.
2049  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2050    return;
2051
2052  // Find the function body that we'll be substituting.
2053  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
2054  Stmt *Pattern = 0;
2055  if (PatternDecl)
2056    Pattern = PatternDecl->getBody(PatternDecl);
2057
2058  if (!Pattern) {
2059    if (DefinitionRequired) {
2060      if (Function->getPrimaryTemplate())
2061        Diag(PointOfInstantiation,
2062             diag::err_explicit_instantiation_undefined_func_template)
2063          << Function->getPrimaryTemplate();
2064      else
2065        Diag(PointOfInstantiation,
2066             diag::err_explicit_instantiation_undefined_member)
2067          << 1 << Function->getDeclName() << Function->getDeclContext();
2068
2069      if (PatternDecl)
2070        Diag(PatternDecl->getLocation(),
2071             diag::note_explicit_instantiation_here);
2072      Function->setInvalidDecl();
2073    } else if (Function->getTemplateSpecializationKind()
2074                 == TSK_ExplicitInstantiationDefinition) {
2075      PendingInstantiations.push_back(
2076        std::make_pair(Function, PointOfInstantiation));
2077    }
2078
2079    return;
2080  }
2081
2082  // C++0x [temp.explicit]p9:
2083  //   Except for inline functions, other explicit instantiation declarations
2084  //   have the effect of suppressing the implicit instantiation of the entity
2085  //   to which they refer.
2086  if (Function->getTemplateSpecializationKind()
2087        == TSK_ExplicitInstantiationDeclaration &&
2088      !PatternDecl->isInlined())
2089    return;
2090
2091  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2092  if (Inst)
2093    return;
2094
2095  // If we're performing recursive template instantiation, create our own
2096  // queue of pending implicit instantiations that we will instantiate later,
2097  // while we're still within our own instantiation context.
2098  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2099  if (Recursive)
2100    PendingInstantiations.swap(SavedPendingInstantiations);
2101
2102  EnterExpressionEvaluationContext EvalContext(*this,
2103                                               Sema::PotentiallyEvaluated);
2104  ActOnStartOfFunctionDef(0, Function);
2105
2106  // Introduce a new scope where local variable instantiations will be
2107  // recorded, unless we're actually a member function within a local
2108  // class, in which case we need to merge our results with the parent
2109  // scope (of the enclosing function).
2110  bool MergeWithParentScope = false;
2111  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2112    MergeWithParentScope = Rec->isLocalClass();
2113
2114  LocalInstantiationScope Scope(*this, MergeWithParentScope);
2115
2116  // Introduce the instantiated function parameters into the local
2117  // instantiation scope, and set the parameter names to those used
2118  // in the template.
2119  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
2120    const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
2121    ParmVarDecl *FunctionParam = Function->getParamDecl(I);
2122    FunctionParam->setDeclName(PatternParam->getDeclName());
2123    Scope.InstantiatedLocal(PatternParam, FunctionParam);
2124  }
2125
2126  // Enter the scope of this instantiation. We don't use
2127  // PushDeclContext because we don't have a scope.
2128  DeclContext *PreviousContext = CurContext;
2129  CurContext = Function;
2130
2131  MultiLevelTemplateArgumentList TemplateArgs =
2132    getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
2133
2134  // If this is a constructor, instantiate the member initializers.
2135  if (const CXXConstructorDecl *Ctor =
2136        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2137    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2138                               TemplateArgs);
2139  }
2140
2141  // Instantiate the function body.
2142  StmtResult Body = SubstStmt(Pattern, TemplateArgs);
2143
2144  if (Body.isInvalid())
2145    Function->setInvalidDecl();
2146
2147  ActOnFinishFunctionBody(Function, Body.get(),
2148                          /*IsInstantiation=*/true);
2149
2150  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2151
2152  CurContext = PreviousContext;
2153
2154  DeclGroupRef DG(Function);
2155  Consumer.HandleTopLevelDecl(DG);
2156
2157  // This class may have local implicit instantiations that need to be
2158  // instantiation within this scope.
2159  PerformPendingInstantiations(/*LocalOnly=*/true);
2160  Scope.Exit();
2161
2162  if (Recursive) {
2163    // Instantiate any pending implicit instantiations found during the
2164    // instantiation of this template.
2165    PerformPendingInstantiations();
2166
2167    // Restore the set of pending implicit instantiations.
2168    PendingInstantiations.swap(SavedPendingInstantiations);
2169  }
2170}
2171
2172/// \brief Instantiate the definition of the given variable from its
2173/// template.
2174///
2175/// \param PointOfInstantiation the point at which the instantiation was
2176/// required. Note that this is not precisely a "point of instantiation"
2177/// for the function, but it's close.
2178///
2179/// \param Var the already-instantiated declaration of a static member
2180/// variable of a class template specialization.
2181///
2182/// \param Recursive if true, recursively instantiates any functions that
2183/// are required by this instantiation.
2184///
2185/// \param DefinitionRequired if true, then we are performing an explicit
2186/// instantiation where an out-of-line definition of the member variable
2187/// is required. Complain if there is no such definition.
2188void Sema::InstantiateStaticDataMemberDefinition(
2189                                          SourceLocation PointOfInstantiation,
2190                                                 VarDecl *Var,
2191                                                 bool Recursive,
2192                                                 bool DefinitionRequired) {
2193  if (Var->isInvalidDecl())
2194    return;
2195
2196  // Find the out-of-line definition of this static data member.
2197  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2198  assert(Def && "This data member was not instantiated from a template?");
2199  assert(Def->isStaticDataMember() && "Not a static data member?");
2200  Def = Def->getOutOfLineDefinition();
2201
2202  if (!Def) {
2203    // We did not find an out-of-line definition of this static data member,
2204    // so we won't perform any instantiation. Rather, we rely on the user to
2205    // instantiate this definition (or provide a specialization for it) in
2206    // another translation unit.
2207    if (DefinitionRequired) {
2208      Def = Var->getInstantiatedFromStaticDataMember();
2209      Diag(PointOfInstantiation,
2210           diag::err_explicit_instantiation_undefined_member)
2211        << 2 << Var->getDeclName() << Var->getDeclContext();
2212      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2213    } else if (Var->getTemplateSpecializationKind()
2214                 == TSK_ExplicitInstantiationDefinition) {
2215      PendingInstantiations.push_back(
2216        std::make_pair(Var, PointOfInstantiation));
2217    }
2218
2219    return;
2220  }
2221
2222  // Never instantiate an explicit specialization.
2223  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2224    return;
2225
2226  // C++0x [temp.explicit]p9:
2227  //   Except for inline functions, other explicit instantiation declarations
2228  //   have the effect of suppressing the implicit instantiation of the entity
2229  //   to which they refer.
2230  if (Var->getTemplateSpecializationKind()
2231        == TSK_ExplicitInstantiationDeclaration)
2232    return;
2233
2234  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2235  if (Inst)
2236    return;
2237
2238  // If we're performing recursive template instantiation, create our own
2239  // queue of pending implicit instantiations that we will instantiate later,
2240  // while we're still within our own instantiation context.
2241  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2242  if (Recursive)
2243    PendingInstantiations.swap(SavedPendingInstantiations);
2244
2245  // Enter the scope of this instantiation. We don't use
2246  // PushDeclContext because we don't have a scope.
2247  DeclContext *PreviousContext = CurContext;
2248  CurContext = Var->getDeclContext();
2249
2250  VarDecl *OldVar = Var;
2251  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2252                                          getTemplateInstantiationArgs(Var)));
2253  CurContext = PreviousContext;
2254
2255  if (Var) {
2256    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2257    assert(MSInfo && "Missing member specialization information?");
2258    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2259                                       MSInfo->getPointOfInstantiation());
2260    DeclGroupRef DG(Var);
2261    Consumer.HandleTopLevelDecl(DG);
2262  }
2263
2264  if (Recursive) {
2265    // Instantiate any pending implicit instantiations found during the
2266    // instantiation of this template.
2267    PerformPendingInstantiations();
2268
2269    // Restore the set of pending implicit instantiations.
2270    PendingInstantiations.swap(SavedPendingInstantiations);
2271  }
2272}
2273
2274void
2275Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2276                                 const CXXConstructorDecl *Tmpl,
2277                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2278
2279  llvm::SmallVector<MemInitTy*, 4> NewInits;
2280  bool AnyErrors = false;
2281
2282  // Instantiate all the initializers.
2283  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2284                                            InitsEnd = Tmpl->init_end();
2285       Inits != InitsEnd; ++Inits) {
2286    CXXBaseOrMemberInitializer *Init = *Inits;
2287
2288    // Only instantiate written initializers, let Sema re-construct implicit
2289    // ones.
2290    if (!Init->isWritten())
2291      continue;
2292
2293    SourceLocation LParenLoc, RParenLoc;
2294    ASTOwningVector<Expr*> NewArgs(*this);
2295
2296    // Instantiate the initializer.
2297    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2298                               LParenLoc, NewArgs, RParenLoc)) {
2299      AnyErrors = true;
2300      continue;
2301    }
2302
2303    MemInitResult NewInit;
2304    if (Init->isBaseInitializer()) {
2305      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2306                                            TemplateArgs,
2307                                            Init->getSourceLocation(),
2308                                            New->getDeclName());
2309      if (!BaseTInfo) {
2310        AnyErrors = true;
2311        New->setInvalidDecl();
2312        continue;
2313      }
2314
2315      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2316                                     (Expr **)NewArgs.data(),
2317                                     NewArgs.size(),
2318                                     Init->getLParenLoc(),
2319                                     Init->getRParenLoc(),
2320                                     New->getParent());
2321    } else if (Init->isMemberInitializer()) {
2322      FieldDecl *Member;
2323
2324      // Is this an anonymous union?
2325      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2326        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2327                                                      UnionInit, TemplateArgs));
2328      else
2329        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2330                                                      Init->getMember(),
2331                                                      TemplateArgs));
2332
2333      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2334                                       NewArgs.size(),
2335                                       Init->getSourceLocation(),
2336                                       Init->getLParenLoc(),
2337                                       Init->getRParenLoc());
2338    }
2339
2340    if (NewInit.isInvalid()) {
2341      AnyErrors = true;
2342      New->setInvalidDecl();
2343    } else {
2344      // FIXME: It would be nice if ASTOwningVector had a release function.
2345      NewArgs.take();
2346
2347      NewInits.push_back((MemInitTy *)NewInit.get());
2348    }
2349  }
2350
2351  // Assign all the initializers to the new constructor.
2352  ActOnMemInitializers(New,
2353                       /*FIXME: ColonLoc */
2354                       SourceLocation(),
2355                       NewInits.data(), NewInits.size(),
2356                       AnyErrors);
2357}
2358
2359// TODO: this could be templated if the various decl types used the
2360// same method name.
2361static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2362                              ClassTemplateDecl *Instance) {
2363  Pattern = Pattern->getCanonicalDecl();
2364
2365  do {
2366    Instance = Instance->getCanonicalDecl();
2367    if (Pattern == Instance) return true;
2368    Instance = Instance->getInstantiatedFromMemberTemplate();
2369  } while (Instance);
2370
2371  return false;
2372}
2373
2374static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2375                              FunctionTemplateDecl *Instance) {
2376  Pattern = Pattern->getCanonicalDecl();
2377
2378  do {
2379    Instance = Instance->getCanonicalDecl();
2380    if (Pattern == Instance) return true;
2381    Instance = Instance->getInstantiatedFromMemberTemplate();
2382  } while (Instance);
2383
2384  return false;
2385}
2386
2387static bool
2388isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2389                  ClassTemplatePartialSpecializationDecl *Instance) {
2390  Pattern
2391    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2392  do {
2393    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2394                                                Instance->getCanonicalDecl());
2395    if (Pattern == Instance)
2396      return true;
2397    Instance = Instance->getInstantiatedFromMember();
2398  } while (Instance);
2399
2400  return false;
2401}
2402
2403static bool isInstantiationOf(CXXRecordDecl *Pattern,
2404                              CXXRecordDecl *Instance) {
2405  Pattern = Pattern->getCanonicalDecl();
2406
2407  do {
2408    Instance = Instance->getCanonicalDecl();
2409    if (Pattern == Instance) return true;
2410    Instance = Instance->getInstantiatedFromMemberClass();
2411  } while (Instance);
2412
2413  return false;
2414}
2415
2416static bool isInstantiationOf(FunctionDecl *Pattern,
2417                              FunctionDecl *Instance) {
2418  Pattern = Pattern->getCanonicalDecl();
2419
2420  do {
2421    Instance = Instance->getCanonicalDecl();
2422    if (Pattern == Instance) return true;
2423    Instance = Instance->getInstantiatedFromMemberFunction();
2424  } while (Instance);
2425
2426  return false;
2427}
2428
2429static bool isInstantiationOf(EnumDecl *Pattern,
2430                              EnumDecl *Instance) {
2431  Pattern = Pattern->getCanonicalDecl();
2432
2433  do {
2434    Instance = Instance->getCanonicalDecl();
2435    if (Pattern == Instance) return true;
2436    Instance = Instance->getInstantiatedFromMemberEnum();
2437  } while (Instance);
2438
2439  return false;
2440}
2441
2442static bool isInstantiationOf(UsingShadowDecl *Pattern,
2443                              UsingShadowDecl *Instance,
2444                              ASTContext &C) {
2445  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2446}
2447
2448static bool isInstantiationOf(UsingDecl *Pattern,
2449                              UsingDecl *Instance,
2450                              ASTContext &C) {
2451  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2452}
2453
2454static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2455                              UsingDecl *Instance,
2456                              ASTContext &C) {
2457  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2458}
2459
2460static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2461                              UsingDecl *Instance,
2462                              ASTContext &C) {
2463  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2464}
2465
2466static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2467                                              VarDecl *Instance) {
2468  assert(Instance->isStaticDataMember());
2469
2470  Pattern = Pattern->getCanonicalDecl();
2471
2472  do {
2473    Instance = Instance->getCanonicalDecl();
2474    if (Pattern == Instance) return true;
2475    Instance = Instance->getInstantiatedFromStaticDataMember();
2476  } while (Instance);
2477
2478  return false;
2479}
2480
2481// Other is the prospective instantiation
2482// D is the prospective pattern
2483static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2484  if (D->getKind() != Other->getKind()) {
2485    if (UnresolvedUsingTypenameDecl *UUD
2486          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2487      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2488        return isInstantiationOf(UUD, UD, Ctx);
2489      }
2490    }
2491
2492    if (UnresolvedUsingValueDecl *UUD
2493          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2494      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2495        return isInstantiationOf(UUD, UD, Ctx);
2496      }
2497    }
2498
2499    return false;
2500  }
2501
2502  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2503    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2504
2505  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2506    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2507
2508  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2509    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2510
2511  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2512    if (Var->isStaticDataMember())
2513      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2514
2515  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2516    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2517
2518  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2519    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2520
2521  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2522        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2523    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2524                             PartialSpec);
2525
2526  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2527    if (!Field->getDeclName()) {
2528      // This is an unnamed field.
2529      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2530        cast<FieldDecl>(D);
2531    }
2532  }
2533
2534  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2535    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2536
2537  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2538    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2539
2540  return D->getDeclName() && isa<NamedDecl>(Other) &&
2541    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2542}
2543
2544template<typename ForwardIterator>
2545static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2546                                      NamedDecl *D,
2547                                      ForwardIterator first,
2548                                      ForwardIterator last) {
2549  for (; first != last; ++first)
2550    if (isInstantiationOf(Ctx, D, *first))
2551      return cast<NamedDecl>(*first);
2552
2553  return 0;
2554}
2555
2556/// \brief Finds the instantiation of the given declaration context
2557/// within the current instantiation.
2558///
2559/// \returns NULL if there was an error
2560DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2561                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2562  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2563    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2564    return cast_or_null<DeclContext>(ID);
2565  } else return DC;
2566}
2567
2568/// \brief Find the instantiation of the given declaration within the
2569/// current instantiation.
2570///
2571/// This routine is intended to be used when \p D is a declaration
2572/// referenced from within a template, that needs to mapped into the
2573/// corresponding declaration within an instantiation. For example,
2574/// given:
2575///
2576/// \code
2577/// template<typename T>
2578/// struct X {
2579///   enum Kind {
2580///     KnownValue = sizeof(T)
2581///   };
2582///
2583///   bool getKind() const { return KnownValue; }
2584/// };
2585///
2586/// template struct X<int>;
2587/// \endcode
2588///
2589/// In the instantiation of X<int>::getKind(), we need to map the
2590/// EnumConstantDecl for KnownValue (which refers to
2591/// X<T>::<Kind>::KnownValue) to its instantiation
2592/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2593/// this mapping from within the instantiation of X<int>.
2594NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2595                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2596  DeclContext *ParentDC = D->getDeclContext();
2597  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2598      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2599      (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext())) {
2600    // D is a local of some kind. Look into the map of local
2601    // declarations to their instantiations.
2602    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2603  }
2604
2605  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2606    if (!Record->isDependentContext())
2607      return D;
2608
2609    // If the RecordDecl is actually the injected-class-name or a
2610    // "templated" declaration for a class template, class template
2611    // partial specialization, or a member class of a class template,
2612    // substitute into the injected-class-name of the class template
2613    // or partial specialization to find the new DeclContext.
2614    QualType T;
2615    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2616
2617    if (ClassTemplate) {
2618      T = ClassTemplate->getInjectedClassNameSpecialization();
2619    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2620                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2621      ClassTemplate = PartialSpec->getSpecializedTemplate();
2622
2623      // If we call SubstType with an InjectedClassNameType here we
2624      // can end up in an infinite loop.
2625      T = Context.getTypeDeclType(Record);
2626      assert(isa<InjectedClassNameType>(T) &&
2627             "type of partial specialization is not an InjectedClassNameType");
2628      T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
2629    }
2630
2631    if (!T.isNull()) {
2632      // Substitute into the injected-class-name to get the type
2633      // corresponding to the instantiation we want, which may also be
2634      // the current instantiation (if we're in a template
2635      // definition). This substitution should never fail, since we
2636      // know we can instantiate the injected-class-name or we
2637      // wouldn't have gotten to the injected-class-name!
2638
2639      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2640      // extra instantiation in the common case?
2641      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2642      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2643
2644      if (!T->isDependentType()) {
2645        assert(T->isRecordType() && "Instantiation must produce a record type");
2646        return T->getAs<RecordType>()->getDecl();
2647      }
2648
2649      // We are performing "partial" template instantiation to create
2650      // the member declarations for the members of a class template
2651      // specialization. Therefore, D is actually referring to something
2652      // in the current instantiation. Look through the current
2653      // context, which contains actual instantiations, to find the
2654      // instantiation of the "current instantiation" that D refers
2655      // to.
2656      bool SawNonDependentContext = false;
2657      for (DeclContext *DC = CurContext; !DC->isFileContext();
2658           DC = DC->getParent()) {
2659        if (ClassTemplateSpecializationDecl *Spec
2660                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2661          if (isInstantiationOf(ClassTemplate,
2662                                Spec->getSpecializedTemplate()))
2663            return Spec;
2664
2665        if (!DC->isDependentContext())
2666          SawNonDependentContext = true;
2667      }
2668
2669      // We're performing "instantiation" of a member of the current
2670      // instantiation while we are type-checking the
2671      // definition. Compute the declaration context and return that.
2672      assert(!SawNonDependentContext &&
2673             "No dependent context while instantiating record");
2674      DeclContext *DC = computeDeclContext(T);
2675      assert(DC &&
2676             "Unable to find declaration for the current instantiation");
2677      return cast<CXXRecordDecl>(DC);
2678    }
2679
2680    // Fall through to deal with other dependent record types (e.g.,
2681    // anonymous unions in class templates).
2682  }
2683
2684  if (!ParentDC->isDependentContext())
2685    return D;
2686
2687  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2688  if (!ParentDC)
2689    return 0;
2690
2691  if (ParentDC != D->getDeclContext()) {
2692    // We performed some kind of instantiation in the parent context,
2693    // so now we need to look into the instantiated parent context to
2694    // find the instantiation of the declaration D.
2695
2696    // If our context used to be dependent, we may need to instantiate
2697    // it before performing lookup into that context.
2698    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2699      if (!Spec->isDependentContext()) {
2700        QualType T = Context.getTypeDeclType(Spec);
2701        const RecordType *Tag = T->getAs<RecordType>();
2702        assert(Tag && "type of non-dependent record is not a RecordType");
2703        if (!Tag->isBeingDefined() &&
2704            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2705          return 0;
2706      }
2707    }
2708
2709    NamedDecl *Result = 0;
2710    if (D->getDeclName()) {
2711      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2712      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2713    } else {
2714      // Since we don't have a name for the entity we're looking for,
2715      // our only option is to walk through all of the declarations to
2716      // find that name. This will occur in a few cases:
2717      //
2718      //   - anonymous struct/union within a template
2719      //   - unnamed class/struct/union/enum within a template
2720      //
2721      // FIXME: Find a better way to find these instantiations!
2722      Result = findInstantiationOf(Context, D,
2723                                   ParentDC->decls_begin(),
2724                                   ParentDC->decls_end());
2725    }
2726
2727    // UsingShadowDecls can instantiate to nothing because of using hiding.
2728    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2729            cast<Decl>(ParentDC)->isInvalidDecl())
2730           && "Unable to find instantiation of declaration!");
2731
2732    D = Result;
2733  }
2734
2735  return D;
2736}
2737
2738/// \brief Performs template instantiation for all implicit template
2739/// instantiations we have seen until this point.
2740void Sema::PerformPendingInstantiations(bool LocalOnly) {
2741  while (!PendingLocalImplicitInstantiations.empty() ||
2742         (!LocalOnly && !PendingInstantiations.empty())) {
2743    PendingImplicitInstantiation Inst;
2744
2745    if (PendingLocalImplicitInstantiations.empty()) {
2746      Inst = PendingInstantiations.front();
2747      PendingInstantiations.pop_front();
2748    } else {
2749      Inst = PendingLocalImplicitInstantiations.front();
2750      PendingLocalImplicitInstantiations.pop_front();
2751    }
2752
2753    // Instantiate function definitions
2754    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2755      PrettyDeclStackTraceEntry CrashInfo(*this, Function, SourceLocation(),
2756                                          "instantiating function definition");
2757      bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
2758                                TSK_ExplicitInstantiationDefinition;
2759      InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true,
2760                                    DefinitionRequired);
2761      continue;
2762    }
2763
2764    // Instantiate static data member definitions.
2765    VarDecl *Var = cast<VarDecl>(Inst.first);
2766    assert(Var->isStaticDataMember() && "Not a static data member?");
2767
2768    // Don't try to instantiate declarations if the most recent redeclaration
2769    // is invalid.
2770    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2771      continue;
2772
2773    // Check if the most recent declaration has changed the specialization kind
2774    // and removed the need for implicit instantiation.
2775    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2776    case TSK_Undeclared:
2777      assert(false && "Cannot instantitiate an undeclared specialization.");
2778    case TSK_ExplicitInstantiationDeclaration:
2779    case TSK_ExplicitSpecialization:
2780      continue;  // No longer need to instantiate this type.
2781    case TSK_ExplicitInstantiationDefinition:
2782      // We only need an instantiation if the pending instantiation *is* the
2783      // explicit instantiation.
2784      if (Var != Var->getMostRecentDeclaration()) continue;
2785    case TSK_ImplicitInstantiation:
2786      break;
2787    }
2788
2789    PrettyDeclStackTraceEntry CrashInfo(*this, Var, Var->getLocation(),
2790                                        "instantiating static data member "
2791                                        "definition");
2792
2793    bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
2794                              TSK_ExplicitInstantiationDefinition;
2795    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true,
2796                                          DefinitionRequired);
2797  }
2798}
2799
2800void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2801                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2802  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2803         E = Pattern->ddiag_end(); I != E; ++I) {
2804    DependentDiagnostic *DD = *I;
2805
2806    switch (DD->getKind()) {
2807    case DependentDiagnostic::Access:
2808      HandleDependentAccessCheck(*DD, TemplateArgs);
2809      break;
2810    }
2811  }
2812}
2813
2814