SemaTemplateInstantiateDecl.cpp revision f0e3e30d42c2c72ece53393d8d5d045e0c24ac70 
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    FD->setUnsupportedFriend(D->isUnsupportedFriend());
554    Owner->addDecl(FD);
555    return FD;
556  }
557
558  NamedDecl *ND = D->getFriendDecl();
559  assert(ND && "friend decl must be a decl or a type!");
560
561  // All of the Visit implementations for the various potential friend
562  // declarations have to be carefully written to work for friend
563  // objects, with the most important detail being that the target
564  // decl should almost certainly not be placed in Owner.
565  Decl *NewND = Visit(ND);
566  if (!NewND) return 0;
567
568  FriendDecl *FD =
569    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
570                       cast<NamedDecl>(NewND), D->getFriendLoc());
571  FD->setAccess(AS_public);
572  FD->setUnsupportedFriend(D->isUnsupportedFriend());
573  Owner->addDecl(FD);
574  return FD;
575}
576
577Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
578  Expr *AssertExpr = D->getAssertExpr();
579
580  // The expression in a static assertion is not potentially evaluated.
581  EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
582
583  ExprResult InstantiatedAssertExpr
584    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
585  if (InstantiatedAssertExpr.isInvalid())
586    return 0;
587
588  ExprResult Message(D->getMessage());
589  D->getMessage();
590  return SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
591                                              InstantiatedAssertExpr.get(),
592                                              Message.get());
593}
594
595Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
596  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
597                                    D->getLocation(), D->getIdentifier(),
598                                    D->getTagKeywordLoc(),
599                                    /*PrevDecl=*/0,
600                                    D->isScoped(), D->isFixed());
601  if (D->isFixed()) {
602    if (TypeSourceInfo* TI = D->getIntegerTypeSourceInfo()) {
603      // If we have type source information for the underlying type, it means it
604      // has been explicitly set by the user. Perform substitution on it before
605      // moving on.
606      SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
607      Enum->setIntegerTypeSourceInfo(SemaRef.SubstType(TI,
608                                                       TemplateArgs,
609                                                       UnderlyingLoc,
610                                                       DeclarationName()));
611
612      if (!Enum->getIntegerTypeSourceInfo())
613        Enum->setIntegerType(SemaRef.Context.IntTy);
614    }
615    else {
616      assert(!D->getIntegerType()->isDependentType()
617             && "Dependent type without type source info");
618      Enum->setIntegerType(D->getIntegerType());
619    }
620  }
621
622  SemaRef.InstantiateAttrs(TemplateArgs, D, Enum);
623
624  Enum->setInstantiationOfMemberEnum(D);
625  Enum->setAccess(D->getAccess());
626  if (SubstQualifier(D, Enum)) return 0;
627  Owner->addDecl(Enum);
628  Enum->startDefinition();
629
630  if (D->getDeclContext()->isFunctionOrMethod())
631    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
632
633  llvm::SmallVector<Decl*, 4> Enumerators;
634
635  EnumConstantDecl *LastEnumConst = 0;
636  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
637         ECEnd = D->enumerator_end();
638       EC != ECEnd; ++EC) {
639    // The specified value for the enumerator.
640    ExprResult Value = SemaRef.Owned((Expr *)0);
641    if (Expr *UninstValue = EC->getInitExpr()) {
642      // The enumerator's value expression is not potentially evaluated.
643      EnterExpressionEvaluationContext Unevaluated(SemaRef,
644                                                   Sema::Unevaluated);
645
646      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
647    }
648
649    // Drop the initial value and continue.
650    bool isInvalid = false;
651    if (Value.isInvalid()) {
652      Value = SemaRef.Owned((Expr *)0);
653      isInvalid = true;
654    }
655
656    EnumConstantDecl *EnumConst
657      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
658                                  EC->getLocation(), EC->getIdentifier(),
659                                  Value.get());
660
661    if (isInvalid) {
662      if (EnumConst)
663        EnumConst->setInvalidDecl();
664      Enum->setInvalidDecl();
665    }
666
667    if (EnumConst) {
668      SemaRef.InstantiateAttrs(TemplateArgs, *EC, EnumConst);
669
670      EnumConst->setAccess(Enum->getAccess());
671      Enum->addDecl(EnumConst);
672      Enumerators.push_back(EnumConst);
673      LastEnumConst = EnumConst;
674
675      if (D->getDeclContext()->isFunctionOrMethod()) {
676        // If the enumeration is within a function or method, record the enum
677        // constant as a local.
678        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
679      }
680    }
681  }
682
683  // FIXME: Fixup LBraceLoc and RBraceLoc
684  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
685  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
686                        Enum,
687                        Enumerators.data(), Enumerators.size(),
688                        0, 0);
689
690  return Enum;
691}
692
693Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
694  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
695  return 0;
696}
697
698Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
699  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
700
701  // Create a local instantiation scope for this class template, which
702  // will contain the instantiations of the template parameters.
703  LocalInstantiationScope Scope(SemaRef);
704  TemplateParameterList *TempParams = D->getTemplateParameters();
705  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
706  if (!InstParams)
707    return NULL;
708
709  CXXRecordDecl *Pattern = D->getTemplatedDecl();
710
711  // Instantiate the qualifier.  We have to do this first in case
712  // we're a friend declaration, because if we are then we need to put
713  // the new declaration in the appropriate context.
714  NestedNameSpecifier *Qualifier = Pattern->getQualifier();
715  if (Qualifier) {
716    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
717                                                 Pattern->getQualifierRange(),
718                                                 TemplateArgs);
719    if (!Qualifier) return 0;
720  }
721
722  CXXRecordDecl *PrevDecl = 0;
723  ClassTemplateDecl *PrevClassTemplate = 0;
724
725  // If this isn't a friend, then it's a member template, in which
726  // case we just want to build the instantiation in the
727  // specialization.  If it is a friend, we want to build it in
728  // the appropriate context.
729  DeclContext *DC = Owner;
730  if (isFriend) {
731    if (Qualifier) {
732      CXXScopeSpec SS;
733      SS.setScopeRep(Qualifier);
734      SS.setRange(Pattern->getQualifierRange());
735      DC = SemaRef.computeDeclContext(SS);
736      if (!DC) return 0;
737    } else {
738      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
739                                           Pattern->getDeclContext(),
740                                           TemplateArgs);
741    }
742
743    // Look for a previous declaration of the template in the owning
744    // context.
745    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
746                   Sema::LookupOrdinaryName, Sema::ForRedeclaration);
747    SemaRef.LookupQualifiedName(R, DC);
748
749    if (R.isSingleResult()) {
750      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
751      if (PrevClassTemplate)
752        PrevDecl = PrevClassTemplate->getTemplatedDecl();
753    }
754
755    if (!PrevClassTemplate && Qualifier) {
756      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
757        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
758        << Pattern->getQualifierRange();
759      return 0;
760    }
761
762    bool AdoptedPreviousTemplateParams = false;
763    if (PrevClassTemplate) {
764      bool Complain = true;
765
766      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
767      // template for struct std::tr1::__detail::_Map_base, where the
768      // template parameters of the friend declaration don't match the
769      // template parameters of the original declaration. In this one
770      // case, we don't complain about the ill-formed friend
771      // declaration.
772      if (isFriend && Pattern->getIdentifier() &&
773          Pattern->getIdentifier()->isStr("_Map_base") &&
774          DC->isNamespace() &&
775          cast<NamespaceDecl>(DC)->getIdentifier() &&
776          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
777        DeclContext *DCParent = DC->getParent();
778        if (DCParent->isNamespace() &&
779            cast<NamespaceDecl>(DCParent)->getIdentifier() &&
780            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
781          DeclContext *DCParent2 = DCParent->getParent();
782          if (DCParent2->isNamespace() &&
783              cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
784              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
785              DCParent2->getParent()->isTranslationUnit())
786            Complain = false;
787        }
788      }
789
790      TemplateParameterList *PrevParams
791        = PrevClassTemplate->getTemplateParameters();
792
793      // Make sure the parameter lists match.
794      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
795                                                  Complain,
796                                                  Sema::TPL_TemplateMatch)) {
797        if (Complain)
798          return 0;
799
800        AdoptedPreviousTemplateParams = true;
801        InstParams = PrevParams;
802      }
803
804      // Do some additional validation, then merge default arguments
805      // from the existing declarations.
806      if (!AdoptedPreviousTemplateParams &&
807          SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
808                                             Sema::TPC_ClassTemplate))
809        return 0;
810    }
811  }
812
813  CXXRecordDecl *RecordInst
814    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
815                            Pattern->getLocation(), Pattern->getIdentifier(),
816                            Pattern->getTagKeywordLoc(), PrevDecl,
817                            /*DelayTypeCreation=*/true);
818
819  if (Qualifier)
820    RecordInst->setQualifierInfo(Qualifier, Pattern->getQualifierRange());
821
822  ClassTemplateDecl *Inst
823    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
824                                D->getIdentifier(), InstParams, RecordInst,
825                                PrevClassTemplate);
826  RecordInst->setDescribedClassTemplate(Inst);
827
828  if (isFriend) {
829    if (PrevClassTemplate)
830      Inst->setAccess(PrevClassTemplate->getAccess());
831    else
832      Inst->setAccess(D->getAccess());
833
834    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
835    // TODO: do we want to track the instantiation progeny of this
836    // friend target decl?
837  } else {
838    Inst->setAccess(D->getAccess());
839    Inst->setInstantiatedFromMemberTemplate(D);
840  }
841
842  // Trigger creation of the type for the instantiation.
843  SemaRef.Context.getInjectedClassNameType(RecordInst,
844                                    Inst->getInjectedClassNameSpecialization());
845
846  // Finish handling of friends.
847  if (isFriend) {
848    DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
849    return Inst;
850  }
851
852  Owner->addDecl(Inst);
853
854  // Instantiate all of the partial specializations of this member class
855  // template.
856  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
857  D->getPartialSpecializations(PartialSpecs);
858  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
859    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
860
861  return Inst;
862}
863
864Decl *
865TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
866                                   ClassTemplatePartialSpecializationDecl *D) {
867  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
868
869  // Lookup the already-instantiated declaration in the instantiation
870  // of the class template and return that.
871  DeclContext::lookup_result Found
872    = Owner->lookup(ClassTemplate->getDeclName());
873  if (Found.first == Found.second)
874    return 0;
875
876  ClassTemplateDecl *InstClassTemplate
877    = dyn_cast<ClassTemplateDecl>(*Found.first);
878  if (!InstClassTemplate)
879    return 0;
880
881  return InstClassTemplate->findPartialSpecInstantiatedFromMember(D);
882}
883
884Decl *
885TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
886  // Create a local instantiation scope for this function template, which
887  // will contain the instantiations of the template parameters and then get
888  // merged with the local instantiation scope for the function template
889  // itself.
890  LocalInstantiationScope Scope(SemaRef);
891
892  TemplateParameterList *TempParams = D->getTemplateParameters();
893  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
894  if (!InstParams)
895    return NULL;
896
897  FunctionDecl *Instantiated = 0;
898  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
899    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
900                                                                 InstParams));
901  else
902    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
903                                                          D->getTemplatedDecl(),
904                                                                InstParams));
905
906  if (!Instantiated)
907    return 0;
908
909  Instantiated->setAccess(D->getAccess());
910
911  // Link the instantiated function template declaration to the function
912  // template from which it was instantiated.
913  FunctionTemplateDecl *InstTemplate
914    = Instantiated->getDescribedFunctionTemplate();
915  InstTemplate->setAccess(D->getAccess());
916  assert(InstTemplate &&
917         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
918
919  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
920
921  // Link the instantiation back to the pattern *unless* this is a
922  // non-definition friend declaration.
923  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
924      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
925    InstTemplate->setInstantiatedFromMemberTemplate(D);
926
927  // Make declarations visible in the appropriate context.
928  if (!isFriend)
929    Owner->addDecl(InstTemplate);
930
931  return InstTemplate;
932}
933
934Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
935  CXXRecordDecl *PrevDecl = 0;
936  if (D->isInjectedClassName())
937    PrevDecl = cast<CXXRecordDecl>(Owner);
938  else if (D->getPreviousDeclaration()) {
939    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
940                                                   D->getPreviousDeclaration(),
941                                                   TemplateArgs);
942    if (!Prev) return 0;
943    PrevDecl = cast<CXXRecordDecl>(Prev);
944  }
945
946  CXXRecordDecl *Record
947    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
948                            D->getLocation(), D->getIdentifier(),
949                            D->getTagKeywordLoc(), PrevDecl);
950
951  // Substitute the nested name specifier, if any.
952  if (SubstQualifier(D, Record))
953    return 0;
954
955  Record->setImplicit(D->isImplicit());
956  // FIXME: Check against AS_none is an ugly hack to work around the issue that
957  // the tag decls introduced by friend class declarations don't have an access
958  // specifier. Remove once this area of the code gets sorted out.
959  if (D->getAccess() != AS_none)
960    Record->setAccess(D->getAccess());
961  if (!D->isInjectedClassName())
962    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
963
964  // If the original function was part of a friend declaration,
965  // inherit its namespace state.
966  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
967    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
968
969  // Make sure that anonymous structs and unions are recorded.
970  if (D->isAnonymousStructOrUnion()) {
971    Record->setAnonymousStructOrUnion(true);
972    if (Record->getDeclContext()->getRedeclContext()->isFunctionOrMethod())
973      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
974  }
975
976  Owner->addDecl(Record);
977  return Record;
978}
979
980/// Normal class members are of more specific types and therefore
981/// don't make it here.  This function serves two purposes:
982///   1) instantiating function templates
983///   2) substituting friend declarations
984/// FIXME: preserve function definitions in case #2
985Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
986                                       TemplateParameterList *TemplateParams) {
987  // Check whether there is already a function template specialization for
988  // this declaration.
989  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
990  void *InsertPos = 0;
991  if (FunctionTemplate && !TemplateParams) {
992    std::pair<const TemplateArgument *, unsigned> Innermost
993      = TemplateArgs.getInnermost();
994
995    FunctionDecl *SpecFunc
996      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
997                                             InsertPos);
998
999    // If we already have a function template specialization, return it.
1000    if (SpecFunc)
1001      return SpecFunc;
1002  }
1003
1004  bool isFriend;
1005  if (FunctionTemplate)
1006    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1007  else
1008    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1009
1010  bool MergeWithParentScope = (TemplateParams != 0) ||
1011    Owner->isFunctionOrMethod() ||
1012    !(isa<Decl>(Owner) &&
1013      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1014  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1015
1016  llvm::SmallVector<ParmVarDecl *, 4> Params;
1017  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1018  TInfo = SubstFunctionType(D, Params);
1019  if (!TInfo)
1020    return 0;
1021  QualType T = TInfo->getType();
1022
1023  NestedNameSpecifier *Qualifier = D->getQualifier();
1024  if (Qualifier) {
1025    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1026                                                 D->getQualifierRange(),
1027                                                 TemplateArgs);
1028    if (!Qualifier) return 0;
1029  }
1030
1031  // If we're instantiating a local function declaration, put the result
1032  // in the owner;  otherwise we need to find the instantiated context.
1033  DeclContext *DC;
1034  if (D->getDeclContext()->isFunctionOrMethod())
1035    DC = Owner;
1036  else if (isFriend && Qualifier) {
1037    CXXScopeSpec SS;
1038    SS.setScopeRep(Qualifier);
1039    SS.setRange(D->getQualifierRange());
1040    DC = SemaRef.computeDeclContext(SS);
1041    if (!DC) return 0;
1042  } else {
1043    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1044                                         TemplateArgs);
1045  }
1046
1047  FunctionDecl *Function =
1048      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
1049                           D->getDeclName(), T, TInfo,
1050                           D->getStorageClass(), D->getStorageClassAsWritten(),
1051                           D->isInlineSpecified(), D->hasWrittenPrototype());
1052
1053  if (Qualifier)
1054    Function->setQualifierInfo(Qualifier, D->getQualifierRange());
1055
1056  DeclContext *LexicalDC = Owner;
1057  if (!isFriend && D->isOutOfLine()) {
1058    assert(D->getDeclContext()->isFileContext());
1059    LexicalDC = D->getDeclContext();
1060  }
1061
1062  Function->setLexicalDeclContext(LexicalDC);
1063
1064  // Attach the parameters
1065  for (unsigned P = 0; P < Params.size(); ++P)
1066    if (Params[P])
1067      Params[P]->setOwningFunction(Function);
1068  Function->setParams(Params.data(), Params.size());
1069
1070  SourceLocation InstantiateAtPOI;
1071  if (TemplateParams) {
1072    // Our resulting instantiation is actually a function template, since we
1073    // are substituting only the outer template parameters. For example, given
1074    //
1075    //   template<typename T>
1076    //   struct X {
1077    //     template<typename U> friend void f(T, U);
1078    //   };
1079    //
1080    //   X<int> x;
1081    //
1082    // We are instantiating the friend function template "f" within X<int>,
1083    // which means substituting int for T, but leaving "f" as a friend function
1084    // template.
1085    // Build the function template itself.
1086    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1087                                                    Function->getLocation(),
1088                                                    Function->getDeclName(),
1089                                                    TemplateParams, Function);
1090    Function->setDescribedFunctionTemplate(FunctionTemplate);
1091
1092    FunctionTemplate->setLexicalDeclContext(LexicalDC);
1093
1094    if (isFriend && D->isThisDeclarationADefinition()) {
1095      // TODO: should we remember this connection regardless of whether
1096      // the friend declaration provided a body?
1097      FunctionTemplate->setInstantiatedFromMemberTemplate(
1098                                           D->getDescribedFunctionTemplate());
1099    }
1100  } else if (FunctionTemplate) {
1101    // Record this function template specialization.
1102    std::pair<const TemplateArgument *, unsigned> Innermost
1103      = TemplateArgs.getInnermost();
1104    Function->setFunctionTemplateSpecialization(FunctionTemplate,
1105                  new (SemaRef.Context) TemplateArgumentList(SemaRef.Context,
1106                                                             Innermost.first,
1107                                                             Innermost.second),
1108                                                InsertPos);
1109  } else if (isFriend && D->isThisDeclarationADefinition()) {
1110    // TODO: should we remember this connection regardless of whether
1111    // the friend declaration provided a body?
1112    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1113  }
1114
1115  if (InitFunctionInstantiation(Function, D))
1116    Function->setInvalidDecl();
1117
1118  bool Redeclaration = false;
1119  bool OverloadableAttrRequired = false;
1120  bool isExplicitSpecialization = false;
1121
1122  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1123                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1124
1125  if (DependentFunctionTemplateSpecializationInfo *Info
1126        = D->getDependentSpecializationInfo()) {
1127    assert(isFriend && "non-friend has dependent specialization info?");
1128
1129    // This needs to be set now for future sanity.
1130    Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1131
1132    // Instantiate the explicit template arguments.
1133    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1134                                          Info->getRAngleLoc());
1135    for (unsigned I = 0, E = Info->getNumTemplateArgs(); I != E; ++I) {
1136      TemplateArgumentLoc Loc;
1137      if (SemaRef.Subst(Info->getTemplateArg(I), Loc, TemplateArgs))
1138        return 0;
1139
1140      ExplicitArgs.addArgument(Loc);
1141    }
1142
1143    // Map the candidate templates to their instantiations.
1144    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1145      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1146                                                Info->getTemplate(I),
1147                                                TemplateArgs);
1148      if (!Temp) return 0;
1149
1150      Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1151    }
1152
1153    if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1154                                                    &ExplicitArgs,
1155                                                    Previous))
1156      Function->setInvalidDecl();
1157
1158    isExplicitSpecialization = true;
1159
1160  } else if (TemplateParams || !FunctionTemplate) {
1161    // Look only into the namespace where the friend would be declared to
1162    // find a previous declaration. This is the innermost enclosing namespace,
1163    // as described in ActOnFriendFunctionDecl.
1164    SemaRef.LookupQualifiedName(Previous, DC);
1165
1166    // In C++, the previous declaration we find might be a tag type
1167    // (class or enum). In this case, the new declaration will hide the
1168    // tag type. Note that this does does not apply if we're declaring a
1169    // typedef (C++ [dcl.typedef]p4).
1170    if (Previous.isSingleTagDecl())
1171      Previous.clear();
1172  }
1173
1174  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1175                                   isExplicitSpecialization, Redeclaration,
1176                                   /*FIXME:*/OverloadableAttrRequired);
1177
1178  NamedDecl *PrincipalDecl = (TemplateParams
1179                              ? cast<NamedDecl>(FunctionTemplate)
1180                              : Function);
1181
1182  // If the original function was part of a friend declaration,
1183  // inherit its namespace state and add it to the owner.
1184  if (isFriend) {
1185    NamedDecl *PrevDecl;
1186    if (TemplateParams)
1187      PrevDecl = FunctionTemplate->getPreviousDeclaration();
1188    else
1189      PrevDecl = Function->getPreviousDeclaration();
1190
1191    PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0);
1192    DC->makeDeclVisibleInContext(PrincipalDecl, /*Recoverable=*/ false);
1193
1194    bool queuedInstantiation = false;
1195
1196    if (!SemaRef.getLangOptions().CPlusPlus0x &&
1197        D->isThisDeclarationADefinition()) {
1198      // Check for a function body.
1199      const FunctionDecl *Definition = 0;
1200      if (Function->hasBody(Definition) &&
1201          Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1202        SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1203          << Function->getDeclName();
1204        SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1205        Function->setInvalidDecl();
1206      }
1207      // Check for redefinitions due to other instantiations of this or
1208      // a similar friend function.
1209      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1210                                           REnd = Function->redecls_end();
1211                R != REnd; ++R) {
1212        if (*R == Function)
1213          continue;
1214        switch (R->getFriendObjectKind()) {
1215        case Decl::FOK_None:
1216          if (!queuedInstantiation && R->isUsed(false)) {
1217            if (MemberSpecializationInfo *MSInfo
1218                = Function->getMemberSpecializationInfo()) {
1219              if (MSInfo->getPointOfInstantiation().isInvalid()) {
1220                SourceLocation Loc = R->getLocation(); // FIXME
1221                MSInfo->setPointOfInstantiation(Loc);
1222                SemaRef.PendingLocalImplicitInstantiations.push_back(
1223                                                 std::make_pair(Function, Loc));
1224                queuedInstantiation = true;
1225              }
1226            }
1227          }
1228          break;
1229        default:
1230          if (const FunctionDecl *RPattern
1231              = R->getTemplateInstantiationPattern())
1232            if (RPattern->hasBody(RPattern)) {
1233              SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1234                << Function->getDeclName();
1235              SemaRef.Diag(R->getLocation(), diag::note_previous_definition);
1236              Function->setInvalidDecl();
1237              break;
1238            }
1239        }
1240      }
1241    }
1242  }
1243
1244  if (Function->isOverloadedOperator() && !DC->isRecord() &&
1245      PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1246    PrincipalDecl->setNonMemberOperator();
1247
1248  return Function;
1249}
1250
1251Decl *
1252TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1253                                      TemplateParameterList *TemplateParams) {
1254  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1255  void *InsertPos = 0;
1256  if (FunctionTemplate && !TemplateParams) {
1257    // We are creating a function template specialization from a function
1258    // template. Check whether there is already a function template
1259    // specialization for this particular set of template arguments.
1260    std::pair<const TemplateArgument *, unsigned> Innermost
1261      = TemplateArgs.getInnermost();
1262
1263    FunctionDecl *SpecFunc
1264      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
1265                                             InsertPos);
1266
1267    // If we already have a function template specialization, return it.
1268    if (SpecFunc)
1269      return SpecFunc;
1270  }
1271
1272  bool isFriend;
1273  if (FunctionTemplate)
1274    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1275  else
1276    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1277
1278  bool MergeWithParentScope = (TemplateParams != 0) ||
1279    !(isa<Decl>(Owner) &&
1280      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1281  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1282
1283  // Instantiate enclosing template arguments for friends.
1284  llvm::SmallVector<TemplateParameterList *, 4> TempParamLists;
1285  unsigned NumTempParamLists = 0;
1286  if (isFriend && (NumTempParamLists = D->getNumTemplateParameterLists())) {
1287    TempParamLists.set_size(NumTempParamLists);
1288    for (unsigned I = 0; I != NumTempParamLists; ++I) {
1289      TemplateParameterList *TempParams = D->getTemplateParameterList(I);
1290      TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1291      if (!InstParams)
1292        return NULL;
1293      TempParamLists[I] = InstParams;
1294    }
1295  }
1296
1297  llvm::SmallVector<ParmVarDecl *, 4> Params;
1298  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1299  TInfo = SubstFunctionType(D, Params);
1300  if (!TInfo)
1301    return 0;
1302  QualType T = TInfo->getType();
1303
1304  // \brief If the type of this function is not *directly* a function
1305  // type, then we're instantiating the a function that was declared
1306  // via a typedef, e.g.,
1307  //
1308  //   typedef int functype(int, int);
1309  //   functype func;
1310  //
1311  // In this case, we'll just go instantiate the ParmVarDecls that we
1312  // synthesized in the method declaration.
1313  if (!isa<FunctionProtoType>(T)) {
1314    assert(!Params.size() && "Instantiating type could not yield parameters");
1315    for (unsigned I = 0, N = D->getNumParams(); I != N; ++I) {
1316      ParmVarDecl *P = SemaRef.SubstParmVarDecl(D->getParamDecl(I),
1317                                                TemplateArgs);
1318      if (!P)
1319        return 0;
1320
1321      Params.push_back(P);
1322    }
1323  }
1324
1325  NestedNameSpecifier *Qualifier = D->getQualifier();
1326  if (Qualifier) {
1327    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1328                                                 D->getQualifierRange(),
1329                                                 TemplateArgs);
1330    if (!Qualifier) return 0;
1331  }
1332
1333  DeclContext *DC = Owner;
1334  if (isFriend) {
1335    if (Qualifier) {
1336      CXXScopeSpec SS;
1337      SS.setScopeRep(Qualifier);
1338      SS.setRange(D->getQualifierRange());
1339      DC = SemaRef.computeDeclContext(SS);
1340
1341      if (DC && SemaRef.RequireCompleteDeclContext(SS, DC))
1342        return 0;
1343    } else {
1344      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1345                                           D->getDeclContext(),
1346                                           TemplateArgs);
1347    }
1348    if (!DC) return 0;
1349  }
1350
1351  // Build the instantiated method declaration.
1352  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1353  CXXMethodDecl *Method = 0;
1354
1355  DeclarationNameInfo NameInfo
1356    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1357  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1358    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1359                                        NameInfo, T, TInfo,
1360                                        Constructor->isExplicit(),
1361                                        Constructor->isInlineSpecified(),
1362                                        false);
1363  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1364    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1365                                       NameInfo, T, TInfo,
1366                                       Destructor->isInlineSpecified(),
1367                                       false);
1368  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1369    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1370                                       NameInfo, T, TInfo,
1371                                       Conversion->isInlineSpecified(),
1372                                       Conversion->isExplicit());
1373  } else {
1374    Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1375                                   NameInfo, T, TInfo,
1376                                   D->isStatic(),
1377                                   D->getStorageClassAsWritten(),
1378                                   D->isInlineSpecified());
1379  }
1380
1381  if (Qualifier)
1382    Method->setQualifierInfo(Qualifier, D->getQualifierRange());
1383
1384  if (TemplateParams) {
1385    // Our resulting instantiation is actually a function template, since we
1386    // are substituting only the outer template parameters. For example, given
1387    //
1388    //   template<typename T>
1389    //   struct X {
1390    //     template<typename U> void f(T, U);
1391    //   };
1392    //
1393    //   X<int> x;
1394    //
1395    // We are instantiating the member template "f" within X<int>, which means
1396    // substituting int for T, but leaving "f" as a member function template.
1397    // Build the function template itself.
1398    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1399                                                    Method->getLocation(),
1400                                                    Method->getDeclName(),
1401                                                    TemplateParams, Method);
1402    if (isFriend) {
1403      FunctionTemplate->setLexicalDeclContext(Owner);
1404      FunctionTemplate->setObjectOfFriendDecl(true);
1405    } else if (D->isOutOfLine())
1406      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1407    Method->setDescribedFunctionTemplate(FunctionTemplate);
1408  } else if (FunctionTemplate) {
1409    // Record this function template specialization.
1410    std::pair<const TemplateArgument *, unsigned> Innermost
1411      = TemplateArgs.getInnermost();
1412    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1413                    new (SemaRef.Context) TemplateArgumentList(SemaRef.Context,
1414                                                              Innermost.first,
1415                                                              Innermost.second),
1416                                              InsertPos);
1417  } else if (!isFriend) {
1418    // Record that this is an instantiation of a member function.
1419    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1420  }
1421
1422  // If we are instantiating a member function defined
1423  // out-of-line, the instantiation will have the same lexical
1424  // context (which will be a namespace scope) as the template.
1425  if (isFriend) {
1426    if (NumTempParamLists)
1427      Method->setTemplateParameterListsInfo(SemaRef.Context,
1428                                            NumTempParamLists,
1429                                            TempParamLists.data());
1430
1431    Method->setLexicalDeclContext(Owner);
1432    Method->setObjectOfFriendDecl(true);
1433  } else if (D->isOutOfLine())
1434    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1435
1436  // Attach the parameters
1437  for (unsigned P = 0; P < Params.size(); ++P)
1438    Params[P]->setOwningFunction(Method);
1439  Method->setParams(Params.data(), Params.size());
1440
1441  if (InitMethodInstantiation(Method, D))
1442    Method->setInvalidDecl();
1443
1444  LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
1445                        Sema::ForRedeclaration);
1446
1447  if (!FunctionTemplate || TemplateParams || isFriend) {
1448    SemaRef.LookupQualifiedName(Previous, Record);
1449
1450    // In C++, the previous declaration we find might be a tag type
1451    // (class or enum). In this case, the new declaration will hide the
1452    // tag type. Note that this does does not apply if we're declaring a
1453    // typedef (C++ [dcl.typedef]p4).
1454    if (Previous.isSingleTagDecl())
1455      Previous.clear();
1456  }
1457
1458  bool Redeclaration = false;
1459  bool OverloadableAttrRequired = false;
1460  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1461                                   /*FIXME:*/OverloadableAttrRequired);
1462
1463  if (D->isPure())
1464    SemaRef.CheckPureMethod(Method, SourceRange());
1465
1466  Method->setAccess(D->getAccess());
1467
1468  if (FunctionTemplate) {
1469    // If there's a function template, let our caller handle it.
1470  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1471    // Don't hide a (potentially) valid declaration with an invalid one.
1472  } else {
1473    NamedDecl *DeclToAdd = (TemplateParams
1474                            ? cast<NamedDecl>(FunctionTemplate)
1475                            : Method);
1476    if (isFriend)
1477      Record->makeDeclVisibleInContext(DeclToAdd);
1478    else
1479      Owner->addDecl(DeclToAdd);
1480  }
1481
1482  return Method;
1483}
1484
1485Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1486  return VisitCXXMethodDecl(D);
1487}
1488
1489Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1490  return VisitCXXMethodDecl(D);
1491}
1492
1493Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1494  return VisitCXXMethodDecl(D);
1495}
1496
1497ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1498  return SemaRef.SubstParmVarDecl(D, TemplateArgs);
1499}
1500
1501Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1502                                                    TemplateTypeParmDecl *D) {
1503  // TODO: don't always clone when decls are refcounted.
1504  const Type* T = D->getTypeForDecl();
1505  assert(T->isTemplateTypeParmType());
1506  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1507
1508  TemplateTypeParmDecl *Inst =
1509    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1510                                 TTPT->getDepth() - TemplateArgs.getNumLevels(),
1511                                 TTPT->getIndex(), D->getIdentifier(),
1512                                 D->wasDeclaredWithTypename(),
1513                                 D->isParameterPack());
1514
1515  if (D->hasDefaultArgument())
1516    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1517
1518  // Introduce this template parameter's instantiation into the instantiation
1519  // scope.
1520  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1521
1522  return Inst;
1523}
1524
1525Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1526                                                 NonTypeTemplateParmDecl *D) {
1527  // Substitute into the type of the non-type template parameter.
1528  QualType T;
1529  TypeSourceInfo *DI = D->getTypeSourceInfo();
1530  if (DI) {
1531    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1532                           D->getDeclName());
1533    if (DI) T = DI->getType();
1534  } else {
1535    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1536                          D->getDeclName());
1537    DI = 0;
1538  }
1539  if (T.isNull())
1540    return 0;
1541
1542  // Check that this type is acceptable for a non-type template parameter.
1543  bool Invalid = false;
1544  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1545  if (T.isNull()) {
1546    T = SemaRef.Context.IntTy;
1547    Invalid = true;
1548  }
1549
1550  NonTypeTemplateParmDecl *Param
1551    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1552                                    D->getDepth() - TemplateArgs.getNumLevels(),
1553                                      D->getPosition(), D->getIdentifier(), T,
1554                                      DI);
1555  if (Invalid)
1556    Param->setInvalidDecl();
1557
1558  Param->setDefaultArgument(D->getDefaultArgument(), false);
1559
1560  // Introduce this template parameter's instantiation into the instantiation
1561  // scope.
1562  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1563  return Param;
1564}
1565
1566Decl *
1567TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1568                                                  TemplateTemplateParmDecl *D) {
1569  // Instantiate the template parameter list of the template template parameter.
1570  TemplateParameterList *TempParams = D->getTemplateParameters();
1571  TemplateParameterList *InstParams;
1572  {
1573    // Perform the actual substitution of template parameters within a new,
1574    // local instantiation scope.
1575    LocalInstantiationScope Scope(SemaRef);
1576    InstParams = SubstTemplateParams(TempParams);
1577    if (!InstParams)
1578      return NULL;
1579  }
1580
1581  // Build the template template parameter.
1582  TemplateTemplateParmDecl *Param
1583    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1584                                   D->getDepth() - TemplateArgs.getNumLevels(),
1585                                       D->getPosition(), D->getIdentifier(),
1586                                       InstParams);
1587  Param->setDefaultArgument(D->getDefaultArgument(), false);
1588
1589  // Introduce this template parameter's instantiation into the instantiation
1590  // scope.
1591  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1592
1593  return Param;
1594}
1595
1596Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1597  // Using directives are never dependent, so they require no explicit
1598
1599  UsingDirectiveDecl *Inst
1600    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1601                                 D->getNamespaceKeyLocation(),
1602                                 D->getQualifierRange(), D->getQualifier(),
1603                                 D->getIdentLocation(),
1604                                 D->getNominatedNamespace(),
1605                                 D->getCommonAncestor());
1606  Owner->addDecl(Inst);
1607  return Inst;
1608}
1609
1610Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1611
1612  // The nested name specifier may be dependent, for example
1613  //     template <typename T> struct t {
1614  //       struct s1 { T f1(); };
1615  //       struct s2 : s1 { using s1::f1; };
1616  //     };
1617  //     template struct t<int>;
1618  // Here, in using s1::f1, s1 refers to t<T>::s1;
1619  // we need to substitute for t<int>::s1.
1620  NestedNameSpecifier *NNS =
1621      SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameDecl(),
1622      D->getNestedNameRange(),
1623      TemplateArgs);
1624  if (!NNS)
1625      return 0;
1626
1627  // The name info is non-dependent, so no transformation
1628  // is required.
1629  DeclarationNameInfo NameInfo = D->getNameInfo();
1630
1631  // We only need to do redeclaration lookups if we're in a class
1632  // scope (in fact, it's not really even possible in non-class
1633  // scopes).
1634  bool CheckRedeclaration = Owner->isRecord();
1635
1636  LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
1637                    Sema::ForRedeclaration);
1638
1639  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1640                                       D->getNestedNameRange(),
1641                                       D->getUsingLocation(),
1642                                       NNS,
1643                                       NameInfo,
1644                                       D->isTypeName());
1645
1646  CXXScopeSpec SS;
1647  SS.setScopeRep(NNS);
1648  SS.setRange(D->getNestedNameRange());
1649
1650  if (CheckRedeclaration) {
1651    Prev.setHideTags(false);
1652    SemaRef.LookupQualifiedName(Prev, Owner);
1653
1654    // Check for invalid redeclarations.
1655    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1656                                            D->isTypeName(), SS,
1657                                            D->getLocation(), Prev))
1658      NewUD->setInvalidDecl();
1659
1660  }
1661
1662  if (!NewUD->isInvalidDecl() &&
1663      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1664                                      D->getLocation()))
1665    NewUD->setInvalidDecl();
1666
1667  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1668  NewUD->setAccess(D->getAccess());
1669  Owner->addDecl(NewUD);
1670
1671  // Don't process the shadow decls for an invalid decl.
1672  if (NewUD->isInvalidDecl())
1673    return NewUD;
1674
1675  bool isFunctionScope = Owner->isFunctionOrMethod();
1676
1677  // Process the shadow decls.
1678  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1679         I != E; ++I) {
1680    UsingShadowDecl *Shadow = *I;
1681    NamedDecl *InstTarget =
1682      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1683                                                   Shadow->getTargetDecl(),
1684                                                   TemplateArgs));
1685
1686    if (CheckRedeclaration &&
1687        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1688      continue;
1689
1690    UsingShadowDecl *InstShadow
1691      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1692    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1693
1694    if (isFunctionScope)
1695      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1696  }
1697
1698  return NewUD;
1699}
1700
1701Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1702  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1703  return 0;
1704}
1705
1706Decl * TemplateDeclInstantiator
1707    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1708  NestedNameSpecifier *NNS =
1709    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1710                                     D->getTargetNestedNameRange(),
1711                                     TemplateArgs);
1712  if (!NNS)
1713    return 0;
1714
1715  CXXScopeSpec SS;
1716  SS.setRange(D->getTargetNestedNameRange());
1717  SS.setScopeRep(NNS);
1718
1719  // Since NameInfo refers to a typename, it cannot be a C++ special name.
1720  // Hence, no tranformation is required for it.
1721  DeclarationNameInfo NameInfo(D->getDeclName(), D->getLocation());
1722  NamedDecl *UD =
1723    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1724                                  D->getUsingLoc(), SS, NameInfo, 0,
1725                                  /*instantiation*/ true,
1726                                  /*typename*/ true, D->getTypenameLoc());
1727  if (UD)
1728    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1729
1730  return UD;
1731}
1732
1733Decl * TemplateDeclInstantiator
1734    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1735  NestedNameSpecifier *NNS =
1736    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1737                                     D->getTargetNestedNameRange(),
1738                                     TemplateArgs);
1739  if (!NNS)
1740    return 0;
1741
1742  CXXScopeSpec SS;
1743  SS.setRange(D->getTargetNestedNameRange());
1744  SS.setScopeRep(NNS);
1745
1746  DeclarationNameInfo NameInfo
1747    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1748
1749  NamedDecl *UD =
1750    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1751                                  D->getUsingLoc(), SS, NameInfo, 0,
1752                                  /*instantiation*/ true,
1753                                  /*typename*/ false, SourceLocation());
1754  if (UD)
1755    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1756
1757  return UD;
1758}
1759
1760Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1761                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1762  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1763  if (D->isInvalidDecl())
1764    return 0;
1765
1766  return Instantiator.Visit(D);
1767}
1768
1769/// \brief Instantiates a nested template parameter list in the current
1770/// instantiation context.
1771///
1772/// \param L The parameter list to instantiate
1773///
1774/// \returns NULL if there was an error
1775TemplateParameterList *
1776TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1777  // Get errors for all the parameters before bailing out.
1778  bool Invalid = false;
1779
1780  unsigned N = L->size();
1781  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1782  ParamVector Params;
1783  Params.reserve(N);
1784  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1785       PI != PE; ++PI) {
1786    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1787    Params.push_back(D);
1788    Invalid = Invalid || !D || D->isInvalidDecl();
1789  }
1790
1791  // Clean up if we had an error.
1792  if (Invalid)
1793    return NULL;
1794
1795  TemplateParameterList *InstL
1796    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1797                                    L->getLAngleLoc(), &Params.front(), N,
1798                                    L->getRAngleLoc());
1799  return InstL;
1800}
1801
1802/// \brief Instantiate the declaration of a class template partial
1803/// specialization.
1804///
1805/// \param ClassTemplate the (instantiated) class template that is partially
1806// specialized by the instantiation of \p PartialSpec.
1807///
1808/// \param PartialSpec the (uninstantiated) class template partial
1809/// specialization that we are instantiating.
1810///
1811/// \returns true if there was an error, false otherwise.
1812bool
1813TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1814                                            ClassTemplateDecl *ClassTemplate,
1815                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1816  // Create a local instantiation scope for this class template partial
1817  // specialization, which will contain the instantiations of the template
1818  // parameters.
1819  LocalInstantiationScope Scope(SemaRef);
1820
1821  // Substitute into the template parameters of the class template partial
1822  // specialization.
1823  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1824  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1825  if (!InstParams)
1826    return true;
1827
1828  // Substitute into the template arguments of the class template partial
1829  // specialization.
1830  const TemplateArgumentLoc *PartialSpecTemplateArgs
1831    = PartialSpec->getTemplateArgsAsWritten();
1832  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1833
1834  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1835  for (unsigned I = 0; I != N; ++I) {
1836    TemplateArgumentLoc Loc;
1837    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1838      return true;
1839    InstTemplateArgs.addArgument(Loc);
1840  }
1841
1842
1843  // Check that the template argument list is well-formed for this
1844  // class template.
1845  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1846                                        InstTemplateArgs.size());
1847  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1848                                        PartialSpec->getLocation(),
1849                                        InstTemplateArgs,
1850                                        false,
1851                                        Converted))
1852    return true;
1853
1854  // Figure out where to insert this class template partial specialization
1855  // in the member template's set of class template partial specializations.
1856  void *InsertPos = 0;
1857  ClassTemplateSpecializationDecl *PrevDecl
1858    = ClassTemplate->findPartialSpecialization(Converted.getFlatArguments(),
1859                                                Converted.flatSize(), InsertPos);
1860
1861  // Build the canonical type that describes the converted template
1862  // arguments of the class template partial specialization.
1863  QualType CanonType
1864    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1865                                                  Converted.getFlatArguments(),
1866                                                    Converted.flatSize());
1867
1868  // Build the fully-sugared type for this class template
1869  // specialization as the user wrote in the specialization
1870  // itself. This means that we'll pretty-print the type retrieved
1871  // from the specialization's declaration the way that the user
1872  // actually wrote the specialization, rather than formatting the
1873  // name based on the "canonical" representation used to store the
1874  // template arguments in the specialization.
1875  TypeSourceInfo *WrittenTy
1876    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1877                                                    TemplateName(ClassTemplate),
1878                                                    PartialSpec->getLocation(),
1879                                                    InstTemplateArgs,
1880                                                    CanonType);
1881
1882  if (PrevDecl) {
1883    // We've already seen a partial specialization with the same template
1884    // parameters and template arguments. This can happen, for example, when
1885    // substituting the outer template arguments ends up causing two
1886    // class template partial specializations of a member class template
1887    // to have identical forms, e.g.,
1888    //
1889    //   template<typename T, typename U>
1890    //   struct Outer {
1891    //     template<typename X, typename Y> struct Inner;
1892    //     template<typename Y> struct Inner<T, Y>;
1893    //     template<typename Y> struct Inner<U, Y>;
1894    //   };
1895    //
1896    //   Outer<int, int> outer; // error: the partial specializations of Inner
1897    //                          // have the same signature.
1898    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1899      << WrittenTy;
1900    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1901      << SemaRef.Context.getTypeDeclType(PrevDecl);
1902    return true;
1903  }
1904
1905
1906  // Create the class template partial specialization declaration.
1907  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1908    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
1909                                                     PartialSpec->getTagKind(),
1910                                                     Owner,
1911                                                     PartialSpec->getLocation(),
1912                                                     InstParams,
1913                                                     ClassTemplate,
1914                                                     Converted,
1915                                                     InstTemplateArgs,
1916                                                     CanonType,
1917                                                     0,
1918                             ClassTemplate->getNextPartialSpecSequenceNumber());
1919  // Substitute the nested name specifier, if any.
1920  if (SubstQualifier(PartialSpec, InstPartialSpec))
1921    return 0;
1922
1923  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1924  InstPartialSpec->setTypeAsWritten(WrittenTy);
1925
1926  // Add this partial specialization to the set of class template partial
1927  // specializations.
1928  ClassTemplate->AddPartialSpecialization(InstPartialSpec, InsertPos);
1929  return false;
1930}
1931
1932TypeSourceInfo*
1933TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1934                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1935  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1936  assert(OldTInfo && "substituting function without type source info");
1937  assert(Params.empty() && "parameter vector is non-empty at start");
1938  TypeSourceInfo *NewTInfo
1939    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
1940                                    D->getTypeSpecStartLoc(),
1941                                    D->getDeclName());
1942  if (!NewTInfo)
1943    return 0;
1944
1945  if (NewTInfo != OldTInfo) {
1946    // Get parameters from the new type info.
1947    TypeLoc OldTL = OldTInfo->getTypeLoc();
1948    if (FunctionProtoTypeLoc *OldProtoLoc
1949                                  = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1950      TypeLoc NewTL = NewTInfo->getTypeLoc();
1951      FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1952      assert(NewProtoLoc && "Missing prototype?");
1953      for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i) {
1954        // FIXME: Variadic templates will break this.
1955        Params.push_back(NewProtoLoc->getArg(i));
1956        SemaRef.CurrentInstantiationScope->InstantiatedLocal(
1957                                                        OldProtoLoc->getArg(i),
1958                                                        NewProtoLoc->getArg(i));
1959      }
1960    }
1961  } else {
1962    // The function type itself was not dependent and therefore no
1963    // substitution occurred. However, we still need to instantiate
1964    // the function parameters themselves.
1965    TypeLoc OldTL = OldTInfo->getTypeLoc();
1966    if (FunctionProtoTypeLoc *OldProtoLoc
1967                                    = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1968      for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
1969        ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
1970        if (!Parm)
1971          return 0;
1972        Params.push_back(Parm);
1973      }
1974    }
1975  }
1976  return NewTInfo;
1977}
1978
1979/// \brief Initializes the common fields of an instantiation function
1980/// declaration (New) from the corresponding fields of its template (Tmpl).
1981///
1982/// \returns true if there was an error
1983bool
1984TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1985                                                    FunctionDecl *Tmpl) {
1986  if (Tmpl->isDeleted())
1987    New->setDeleted();
1988
1989  // If we are performing substituting explicitly-specified template arguments
1990  // or deduced template arguments into a function template and we reach this
1991  // point, we are now past the point where SFINAE applies and have committed
1992  // to keeping the new function template specialization. We therefore
1993  // convert the active template instantiation for the function template
1994  // into a template instantiation for this specific function template
1995  // specialization, which is not a SFINAE context, so that we diagnose any
1996  // further errors in the declaration itself.
1997  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1998  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1999  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
2000      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
2001    if (FunctionTemplateDecl *FunTmpl
2002          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
2003      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
2004             "Deduction from the wrong function template?");
2005      (void) FunTmpl;
2006      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
2007      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
2008      --SemaRef.NonInstantiationEntries;
2009    }
2010  }
2011
2012  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
2013  assert(Proto && "Function template without prototype?");
2014
2015  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
2016      Proto->getNoReturnAttr()) {
2017    // The function has an exception specification or a "noreturn"
2018    // attribute. Substitute into each of the exception types.
2019    llvm::SmallVector<QualType, 4> Exceptions;
2020    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
2021      // FIXME: Poor location information!
2022      QualType T
2023        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
2024                            New->getLocation(), New->getDeclName());
2025      if (T.isNull() ||
2026          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
2027        continue;
2028
2029      Exceptions.push_back(T);
2030    }
2031
2032    // Rebuild the function type
2033
2034    const FunctionProtoType *NewProto
2035      = New->getType()->getAs<FunctionProtoType>();
2036    assert(NewProto && "Template instantiation without function prototype?");
2037    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
2038                                                 NewProto->arg_type_begin(),
2039                                                 NewProto->getNumArgs(),
2040                                                 NewProto->isVariadic(),
2041                                                 NewProto->getTypeQuals(),
2042                                                 Proto->hasExceptionSpec(),
2043                                                 Proto->hasAnyExceptionSpec(),
2044                                                 Exceptions.size(),
2045                                                 Exceptions.data(),
2046                                                 Proto->getExtInfo()));
2047  }
2048
2049  SemaRef.InstantiateAttrs(TemplateArgs, Tmpl, New);
2050
2051  return false;
2052}
2053
2054/// \brief Initializes common fields of an instantiated method
2055/// declaration (New) from the corresponding fields of its template
2056/// (Tmpl).
2057///
2058/// \returns true if there was an error
2059bool
2060TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
2061                                                  CXXMethodDecl *Tmpl) {
2062  if (InitFunctionInstantiation(New, Tmpl))
2063    return true;
2064
2065  New->setAccess(Tmpl->getAccess());
2066  if (Tmpl->isVirtualAsWritten())
2067    New->setVirtualAsWritten(true);
2068
2069  // FIXME: attributes
2070  // FIXME: New needs a pointer to Tmpl
2071  return false;
2072}
2073
2074/// \brief Instantiate the definition of the given function from its
2075/// template.
2076///
2077/// \param PointOfInstantiation the point at which the instantiation was
2078/// required. Note that this is not precisely a "point of instantiation"
2079/// for the function, but it's close.
2080///
2081/// \param Function the already-instantiated declaration of a
2082/// function template specialization or member function of a class template
2083/// specialization.
2084///
2085/// \param Recursive if true, recursively instantiates any functions that
2086/// are required by this instantiation.
2087///
2088/// \param DefinitionRequired if true, then we are performing an explicit
2089/// instantiation where the body of the function is required. Complain if
2090/// there is no such body.
2091void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
2092                                         FunctionDecl *Function,
2093                                         bool Recursive,
2094                                         bool DefinitionRequired) {
2095  if (Function->isInvalidDecl() || Function->hasBody())
2096    return;
2097
2098  // Never instantiate an explicit specialization.
2099  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2100    return;
2101
2102  // Find the function body that we'll be substituting.
2103  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
2104  Stmt *Pattern = 0;
2105  if (PatternDecl)
2106    Pattern = PatternDecl->getBody(PatternDecl);
2107
2108  if (!Pattern) {
2109    if (DefinitionRequired) {
2110      if (Function->getPrimaryTemplate())
2111        Diag(PointOfInstantiation,
2112             diag::err_explicit_instantiation_undefined_func_template)
2113          << Function->getPrimaryTemplate();
2114      else
2115        Diag(PointOfInstantiation,
2116             diag::err_explicit_instantiation_undefined_member)
2117          << 1 << Function->getDeclName() << Function->getDeclContext();
2118
2119      if (PatternDecl)
2120        Diag(PatternDecl->getLocation(),
2121             diag::note_explicit_instantiation_here);
2122      Function->setInvalidDecl();
2123    } else if (Function->getTemplateSpecializationKind()
2124                 == TSK_ExplicitInstantiationDefinition) {
2125      PendingInstantiations.push_back(
2126        std::make_pair(Function, PointOfInstantiation));
2127    }
2128
2129    return;
2130  }
2131
2132  // C++0x [temp.explicit]p9:
2133  //   Except for inline functions, other explicit instantiation declarations
2134  //   have the effect of suppressing the implicit instantiation of the entity
2135  //   to which they refer.
2136  if (Function->getTemplateSpecializationKind()
2137        == TSK_ExplicitInstantiationDeclaration &&
2138      !PatternDecl->isInlined())
2139    return;
2140
2141  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2142  if (Inst)
2143    return;
2144
2145  // If we're performing recursive template instantiation, create our own
2146  // queue of pending implicit instantiations that we will instantiate later,
2147  // while we're still within our own instantiation context.
2148  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2149  if (Recursive)
2150    PendingInstantiations.swap(SavedPendingInstantiations);
2151
2152  EnterExpressionEvaluationContext EvalContext(*this,
2153                                               Sema::PotentiallyEvaluated);
2154  ActOnStartOfFunctionDef(0, Function);
2155
2156  // Introduce a new scope where local variable instantiations will be
2157  // recorded, unless we're actually a member function within a local
2158  // class, in which case we need to merge our results with the parent
2159  // scope (of the enclosing function).
2160  bool MergeWithParentScope = false;
2161  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2162    MergeWithParentScope = Rec->isLocalClass();
2163
2164  LocalInstantiationScope Scope(*this, MergeWithParentScope);
2165
2166  // Introduce the instantiated function parameters into the local
2167  // instantiation scope, and set the parameter names to those used
2168  // in the template.
2169  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
2170    const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
2171    ParmVarDecl *FunctionParam = Function->getParamDecl(I);
2172    FunctionParam->setDeclName(PatternParam->getDeclName());
2173    Scope.InstantiatedLocal(PatternParam, FunctionParam);
2174  }
2175
2176  // Enter the scope of this instantiation. We don't use
2177  // PushDeclContext because we don't have a scope.
2178  DeclContext *PreviousContext = CurContext;
2179  CurContext = Function;
2180
2181  MultiLevelTemplateArgumentList TemplateArgs =
2182    getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
2183
2184  // If this is a constructor, instantiate the member initializers.
2185  if (const CXXConstructorDecl *Ctor =
2186        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2187    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2188                               TemplateArgs);
2189  }
2190
2191  // Instantiate the function body.
2192  StmtResult Body = SubstStmt(Pattern, TemplateArgs);
2193
2194  if (Body.isInvalid())
2195    Function->setInvalidDecl();
2196
2197  ActOnFinishFunctionBody(Function, Body.get(),
2198                          /*IsInstantiation=*/true);
2199
2200  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2201
2202  CurContext = PreviousContext;
2203
2204  DeclGroupRef DG(Function);
2205  Consumer.HandleTopLevelDecl(DG);
2206
2207  // This class may have local implicit instantiations that need to be
2208  // instantiation within this scope.
2209  PerformPendingInstantiations(/*LocalOnly=*/true);
2210  Scope.Exit();
2211
2212  if (Recursive) {
2213    // Instantiate any pending implicit instantiations found during the
2214    // instantiation of this template.
2215    PerformPendingInstantiations();
2216
2217    // Restore the set of pending implicit instantiations.
2218    PendingInstantiations.swap(SavedPendingInstantiations);
2219  }
2220}
2221
2222/// \brief Instantiate the definition of the given variable from its
2223/// template.
2224///
2225/// \param PointOfInstantiation the point at which the instantiation was
2226/// required. Note that this is not precisely a "point of instantiation"
2227/// for the function, but it's close.
2228///
2229/// \param Var the already-instantiated declaration of a static member
2230/// variable of a class template specialization.
2231///
2232/// \param Recursive if true, recursively instantiates any functions that
2233/// are required by this instantiation.
2234///
2235/// \param DefinitionRequired if true, then we are performing an explicit
2236/// instantiation where an out-of-line definition of the member variable
2237/// is required. Complain if there is no such definition.
2238void Sema::InstantiateStaticDataMemberDefinition(
2239                                          SourceLocation PointOfInstantiation,
2240                                                 VarDecl *Var,
2241                                                 bool Recursive,
2242                                                 bool DefinitionRequired) {
2243  if (Var->isInvalidDecl())
2244    return;
2245
2246  // Find the out-of-line definition of this static data member.
2247  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2248  assert(Def && "This data member was not instantiated from a template?");
2249  assert(Def->isStaticDataMember() && "Not a static data member?");
2250  Def = Def->getOutOfLineDefinition();
2251
2252  if (!Def) {
2253    // We did not find an out-of-line definition of this static data member,
2254    // so we won't perform any instantiation. Rather, we rely on the user to
2255    // instantiate this definition (or provide a specialization for it) in
2256    // another translation unit.
2257    if (DefinitionRequired) {
2258      Def = Var->getInstantiatedFromStaticDataMember();
2259      Diag(PointOfInstantiation,
2260           diag::err_explicit_instantiation_undefined_member)
2261        << 2 << Var->getDeclName() << Var->getDeclContext();
2262      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2263    } else if (Var->getTemplateSpecializationKind()
2264                 == TSK_ExplicitInstantiationDefinition) {
2265      PendingInstantiations.push_back(
2266        std::make_pair(Var, PointOfInstantiation));
2267    }
2268
2269    return;
2270  }
2271
2272  // Never instantiate an explicit specialization.
2273  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2274    return;
2275
2276  // C++0x [temp.explicit]p9:
2277  //   Except for inline functions, other explicit instantiation declarations
2278  //   have the effect of suppressing the implicit instantiation of the entity
2279  //   to which they refer.
2280  if (Var->getTemplateSpecializationKind()
2281        == TSK_ExplicitInstantiationDeclaration)
2282    return;
2283
2284  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2285  if (Inst)
2286    return;
2287
2288  // If we're performing recursive template instantiation, create our own
2289  // queue of pending implicit instantiations that we will instantiate later,
2290  // while we're still within our own instantiation context.
2291  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2292  if (Recursive)
2293    PendingInstantiations.swap(SavedPendingInstantiations);
2294
2295  // Enter the scope of this instantiation. We don't use
2296  // PushDeclContext because we don't have a scope.
2297  DeclContext *PreviousContext = CurContext;
2298  CurContext = Var->getDeclContext();
2299
2300  VarDecl *OldVar = Var;
2301  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2302                                          getTemplateInstantiationArgs(Var)));
2303  CurContext = PreviousContext;
2304
2305  if (Var) {
2306    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2307    assert(MSInfo && "Missing member specialization information?");
2308    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2309                                       MSInfo->getPointOfInstantiation());
2310    DeclGroupRef DG(Var);
2311    Consumer.HandleTopLevelDecl(DG);
2312  }
2313
2314  if (Recursive) {
2315    // Instantiate any pending implicit instantiations found during the
2316    // instantiation of this template.
2317    PerformPendingInstantiations();
2318
2319    // Restore the set of pending implicit instantiations.
2320    PendingInstantiations.swap(SavedPendingInstantiations);
2321  }
2322}
2323
2324void
2325Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2326                                 const CXXConstructorDecl *Tmpl,
2327                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2328
2329  llvm::SmallVector<MemInitTy*, 4> NewInits;
2330  bool AnyErrors = false;
2331
2332  // Instantiate all the initializers.
2333  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2334                                            InitsEnd = Tmpl->init_end();
2335       Inits != InitsEnd; ++Inits) {
2336    CXXBaseOrMemberInitializer *Init = *Inits;
2337
2338    // Only instantiate written initializers, let Sema re-construct implicit
2339    // ones.
2340    if (!Init->isWritten())
2341      continue;
2342
2343    SourceLocation LParenLoc, RParenLoc;
2344    ASTOwningVector<Expr*> NewArgs(*this);
2345
2346    // Instantiate the initializer.
2347    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2348                               LParenLoc, NewArgs, RParenLoc)) {
2349      AnyErrors = true;
2350      continue;
2351    }
2352
2353    MemInitResult NewInit;
2354    if (Init->isBaseInitializer()) {
2355      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2356                                            TemplateArgs,
2357                                            Init->getSourceLocation(),
2358                                            New->getDeclName());
2359      if (!BaseTInfo) {
2360        AnyErrors = true;
2361        New->setInvalidDecl();
2362        continue;
2363      }
2364
2365      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2366                                     (Expr **)NewArgs.data(),
2367                                     NewArgs.size(),
2368                                     Init->getLParenLoc(),
2369                                     Init->getRParenLoc(),
2370                                     New->getParent());
2371    } else if (Init->isMemberInitializer()) {
2372      FieldDecl *Member;
2373
2374      // Is this an anonymous union?
2375      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2376        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2377                                                      UnionInit, TemplateArgs));
2378      else
2379        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2380                                                      Init->getMember(),
2381                                                      TemplateArgs));
2382
2383      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2384                                       NewArgs.size(),
2385                                       Init->getSourceLocation(),
2386                                       Init->getLParenLoc(),
2387                                       Init->getRParenLoc());
2388    }
2389
2390    if (NewInit.isInvalid()) {
2391      AnyErrors = true;
2392      New->setInvalidDecl();
2393    } else {
2394      // FIXME: It would be nice if ASTOwningVector had a release function.
2395      NewArgs.take();
2396
2397      NewInits.push_back((MemInitTy *)NewInit.get());
2398    }
2399  }
2400
2401  // Assign all the initializers to the new constructor.
2402  ActOnMemInitializers(New,
2403                       /*FIXME: ColonLoc */
2404                       SourceLocation(),
2405                       NewInits.data(), NewInits.size(),
2406                       AnyErrors);
2407}
2408
2409// TODO: this could be templated if the various decl types used the
2410// same method name.
2411static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2412                              ClassTemplateDecl *Instance) {
2413  Pattern = Pattern->getCanonicalDecl();
2414
2415  do {
2416    Instance = Instance->getCanonicalDecl();
2417    if (Pattern == Instance) return true;
2418    Instance = Instance->getInstantiatedFromMemberTemplate();
2419  } while (Instance);
2420
2421  return false;
2422}
2423
2424static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2425                              FunctionTemplateDecl *Instance) {
2426  Pattern = Pattern->getCanonicalDecl();
2427
2428  do {
2429    Instance = Instance->getCanonicalDecl();
2430    if (Pattern == Instance) return true;
2431    Instance = Instance->getInstantiatedFromMemberTemplate();
2432  } while (Instance);
2433
2434  return false;
2435}
2436
2437static bool
2438isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2439                  ClassTemplatePartialSpecializationDecl *Instance) {
2440  Pattern
2441    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2442  do {
2443    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2444                                                Instance->getCanonicalDecl());
2445    if (Pattern == Instance)
2446      return true;
2447    Instance = Instance->getInstantiatedFromMember();
2448  } while (Instance);
2449
2450  return false;
2451}
2452
2453static bool isInstantiationOf(CXXRecordDecl *Pattern,
2454                              CXXRecordDecl *Instance) {
2455  Pattern = Pattern->getCanonicalDecl();
2456
2457  do {
2458    Instance = Instance->getCanonicalDecl();
2459    if (Pattern == Instance) return true;
2460    Instance = Instance->getInstantiatedFromMemberClass();
2461  } while (Instance);
2462
2463  return false;
2464}
2465
2466static bool isInstantiationOf(FunctionDecl *Pattern,
2467                              FunctionDecl *Instance) {
2468  Pattern = Pattern->getCanonicalDecl();
2469
2470  do {
2471    Instance = Instance->getCanonicalDecl();
2472    if (Pattern == Instance) return true;
2473    Instance = Instance->getInstantiatedFromMemberFunction();
2474  } while (Instance);
2475
2476  return false;
2477}
2478
2479static bool isInstantiationOf(EnumDecl *Pattern,
2480                              EnumDecl *Instance) {
2481  Pattern = Pattern->getCanonicalDecl();
2482
2483  do {
2484    Instance = Instance->getCanonicalDecl();
2485    if (Pattern == Instance) return true;
2486    Instance = Instance->getInstantiatedFromMemberEnum();
2487  } while (Instance);
2488
2489  return false;
2490}
2491
2492static bool isInstantiationOf(UsingShadowDecl *Pattern,
2493                              UsingShadowDecl *Instance,
2494                              ASTContext &C) {
2495  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2496}
2497
2498static bool isInstantiationOf(UsingDecl *Pattern,
2499                              UsingDecl *Instance,
2500                              ASTContext &C) {
2501  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2502}
2503
2504static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2505                              UsingDecl *Instance,
2506                              ASTContext &C) {
2507  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2508}
2509
2510static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2511                              UsingDecl *Instance,
2512                              ASTContext &C) {
2513  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2514}
2515
2516static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2517                                              VarDecl *Instance) {
2518  assert(Instance->isStaticDataMember());
2519
2520  Pattern = Pattern->getCanonicalDecl();
2521
2522  do {
2523    Instance = Instance->getCanonicalDecl();
2524    if (Pattern == Instance) return true;
2525    Instance = Instance->getInstantiatedFromStaticDataMember();
2526  } while (Instance);
2527
2528  return false;
2529}
2530
2531// Other is the prospective instantiation
2532// D is the prospective pattern
2533static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2534  if (D->getKind() != Other->getKind()) {
2535    if (UnresolvedUsingTypenameDecl *UUD
2536          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2537      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2538        return isInstantiationOf(UUD, UD, Ctx);
2539      }
2540    }
2541
2542    if (UnresolvedUsingValueDecl *UUD
2543          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2544      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2545        return isInstantiationOf(UUD, UD, Ctx);
2546      }
2547    }
2548
2549    return false;
2550  }
2551
2552  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2553    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2554
2555  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2556    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2557
2558  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2559    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2560
2561  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2562    if (Var->isStaticDataMember())
2563      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2564
2565  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2566    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2567
2568  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2569    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2570
2571  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2572        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2573    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2574                             PartialSpec);
2575
2576  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2577    if (!Field->getDeclName()) {
2578      // This is an unnamed field.
2579      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2580        cast<FieldDecl>(D);
2581    }
2582  }
2583
2584  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2585    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2586
2587  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2588    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2589
2590  return D->getDeclName() && isa<NamedDecl>(Other) &&
2591    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2592}
2593
2594template<typename ForwardIterator>
2595static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2596                                      NamedDecl *D,
2597                                      ForwardIterator first,
2598                                      ForwardIterator last) {
2599  for (; first != last; ++first)
2600    if (isInstantiationOf(Ctx, D, *first))
2601      return cast<NamedDecl>(*first);
2602
2603  return 0;
2604}
2605
2606/// \brief Finds the instantiation of the given declaration context
2607/// within the current instantiation.
2608///
2609/// \returns NULL if there was an error
2610DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2611                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2612  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2613    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2614    return cast_or_null<DeclContext>(ID);
2615  } else return DC;
2616}
2617
2618/// \brief Find the instantiation of the given declaration within the
2619/// current instantiation.
2620///
2621/// This routine is intended to be used when \p D is a declaration
2622/// referenced from within a template, that needs to mapped into the
2623/// corresponding declaration within an instantiation. For example,
2624/// given:
2625///
2626/// \code
2627/// template<typename T>
2628/// struct X {
2629///   enum Kind {
2630///     KnownValue = sizeof(T)
2631///   };
2632///
2633///   bool getKind() const { return KnownValue; }
2634/// };
2635///
2636/// template struct X<int>;
2637/// \endcode
2638///
2639/// In the instantiation of X<int>::getKind(), we need to map the
2640/// EnumConstantDecl for KnownValue (which refers to
2641/// X<T>::<Kind>::KnownValue) to its instantiation
2642/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2643/// this mapping from within the instantiation of X<int>.
2644NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2645                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2646  DeclContext *ParentDC = D->getDeclContext();
2647  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2648      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2649      (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext())) {
2650    // D is a local of some kind. Look into the map of local
2651    // declarations to their instantiations.
2652    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2653  }
2654
2655  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2656    if (!Record->isDependentContext())
2657      return D;
2658
2659    // If the RecordDecl is actually the injected-class-name or a
2660    // "templated" declaration for a class template, class template
2661    // partial specialization, or a member class of a class template,
2662    // substitute into the injected-class-name of the class template
2663    // or partial specialization to find the new DeclContext.
2664    QualType T;
2665    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2666
2667    if (ClassTemplate) {
2668      T = ClassTemplate->getInjectedClassNameSpecialization();
2669    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2670                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2671      ClassTemplate = PartialSpec->getSpecializedTemplate();
2672
2673      // If we call SubstType with an InjectedClassNameType here we
2674      // can end up in an infinite loop.
2675      T = Context.getTypeDeclType(Record);
2676      assert(isa<InjectedClassNameType>(T) &&
2677             "type of partial specialization is not an InjectedClassNameType");
2678      T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
2679    }
2680
2681    if (!T.isNull()) {
2682      // Substitute into the injected-class-name to get the type
2683      // corresponding to the instantiation we want, which may also be
2684      // the current instantiation (if we're in a template
2685      // definition). This substitution should never fail, since we
2686      // know we can instantiate the injected-class-name or we
2687      // wouldn't have gotten to the injected-class-name!
2688
2689      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2690      // extra instantiation in the common case?
2691      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2692      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2693
2694      if (!T->isDependentType()) {
2695        assert(T->isRecordType() && "Instantiation must produce a record type");
2696        return T->getAs<RecordType>()->getDecl();
2697      }
2698
2699      // We are performing "partial" template instantiation to create
2700      // the member declarations for the members of a class template
2701      // specialization. Therefore, D is actually referring to something
2702      // in the current instantiation. Look through the current
2703      // context, which contains actual instantiations, to find the
2704      // instantiation of the "current instantiation" that D refers
2705      // to.
2706      bool SawNonDependentContext = false;
2707      for (DeclContext *DC = CurContext; !DC->isFileContext();
2708           DC = DC->getParent()) {
2709        if (ClassTemplateSpecializationDecl *Spec
2710                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2711          if (isInstantiationOf(ClassTemplate,
2712                                Spec->getSpecializedTemplate()))
2713            return Spec;
2714
2715        if (!DC->isDependentContext())
2716          SawNonDependentContext = true;
2717      }
2718
2719      // We're performing "instantiation" of a member of the current
2720      // instantiation while we are type-checking the
2721      // definition. Compute the declaration context and return that.
2722      assert(!SawNonDependentContext &&
2723             "No dependent context while instantiating record");
2724      DeclContext *DC = computeDeclContext(T);
2725      assert(DC &&
2726             "Unable to find declaration for the current instantiation");
2727      return cast<CXXRecordDecl>(DC);
2728    }
2729
2730    // Fall through to deal with other dependent record types (e.g.,
2731    // anonymous unions in class templates).
2732  }
2733
2734  if (!ParentDC->isDependentContext())
2735    return D;
2736
2737  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2738  if (!ParentDC)
2739    return 0;
2740
2741  if (ParentDC != D->getDeclContext()) {
2742    // We performed some kind of instantiation in the parent context,
2743    // so now we need to look into the instantiated parent context to
2744    // find the instantiation of the declaration D.
2745
2746    // If our context used to be dependent, we may need to instantiate
2747    // it before performing lookup into that context.
2748    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2749      if (!Spec->isDependentContext()) {
2750        QualType T = Context.getTypeDeclType(Spec);
2751        const RecordType *Tag = T->getAs<RecordType>();
2752        assert(Tag && "type of non-dependent record is not a RecordType");
2753        if (!Tag->isBeingDefined() &&
2754            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2755          return 0;
2756      }
2757    }
2758
2759    NamedDecl *Result = 0;
2760    if (D->getDeclName()) {
2761      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2762      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2763    } else {
2764      // Since we don't have a name for the entity we're looking for,
2765      // our only option is to walk through all of the declarations to
2766      // find that name. This will occur in a few cases:
2767      //
2768      //   - anonymous struct/union within a template
2769      //   - unnamed class/struct/union/enum within a template
2770      //
2771      // FIXME: Find a better way to find these instantiations!
2772      Result = findInstantiationOf(Context, D,
2773                                   ParentDC->decls_begin(),
2774                                   ParentDC->decls_end());
2775    }
2776
2777    // UsingShadowDecls can instantiate to nothing because of using hiding.
2778    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2779            cast<Decl>(ParentDC)->isInvalidDecl())
2780           && "Unable to find instantiation of declaration!");
2781
2782    D = Result;
2783  }
2784
2785  return D;
2786}
2787
2788/// \brief Performs template instantiation for all implicit template
2789/// instantiations we have seen until this point.
2790void Sema::PerformPendingInstantiations(bool LocalOnly) {
2791  while (!PendingLocalImplicitInstantiations.empty() ||
2792         (!LocalOnly && !PendingInstantiations.empty())) {
2793    PendingImplicitInstantiation Inst;
2794
2795    if (PendingLocalImplicitInstantiations.empty()) {
2796      Inst = PendingInstantiations.front();
2797      PendingInstantiations.pop_front();
2798    } else {
2799      Inst = PendingLocalImplicitInstantiations.front();
2800      PendingLocalImplicitInstantiations.pop_front();
2801    }
2802
2803    // Instantiate function definitions
2804    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2805      PrettyDeclStackTraceEntry CrashInfo(*this, Function, SourceLocation(),
2806                                          "instantiating function definition");
2807      bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
2808                                TSK_ExplicitInstantiationDefinition;
2809      InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true,
2810                                    DefinitionRequired);
2811      continue;
2812    }
2813
2814    // Instantiate static data member definitions.
2815    VarDecl *Var = cast<VarDecl>(Inst.first);
2816    assert(Var->isStaticDataMember() && "Not a static data member?");
2817
2818    // Don't try to instantiate declarations if the most recent redeclaration
2819    // is invalid.
2820    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2821      continue;
2822
2823    // Check if the most recent declaration has changed the specialization kind
2824    // and removed the need for implicit instantiation.
2825    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2826    case TSK_Undeclared:
2827      assert(false && "Cannot instantitiate an undeclared specialization.");
2828    case TSK_ExplicitInstantiationDeclaration:
2829    case TSK_ExplicitSpecialization:
2830      continue;  // No longer need to instantiate this type.
2831    case TSK_ExplicitInstantiationDefinition:
2832      // We only need an instantiation if the pending instantiation *is* the
2833      // explicit instantiation.
2834      if (Var != Var->getMostRecentDeclaration()) continue;
2835    case TSK_ImplicitInstantiation:
2836      break;
2837    }
2838
2839    PrettyDeclStackTraceEntry CrashInfo(*this, Var, Var->getLocation(),
2840                                        "instantiating static data member "
2841                                        "definition");
2842
2843    bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
2844                              TSK_ExplicitInstantiationDefinition;
2845    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true,
2846                                          DefinitionRequired);
2847  }
2848}
2849
2850void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2851                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2852  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2853         E = Pattern->ddiag_end(); I != E; ++I) {
2854    DependentDiagnostic *DD = *I;
2855
2856    switch (DD->getKind()) {
2857    case DependentDiagnostic::Access:
2858      HandleDependentAccessCheck(*DD, TemplateArgs);
2859      break;
2860    }
2861  }
2862}
2863