SemaTemplateInstantiateDecl.cpp revision 238058c372cfb7bdaf489f51171eb1380ebfd6a6 
1//===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//===----------------------------------------------------------------------===/
8//
9//  This file implements C++ template instantiation for declarations.
10//
11//===----------------------------------------------------------------------===/
12#include "Sema.h"
13#include "Lookup.h"
14#include "clang/AST/ASTConsumer.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/DeclTemplate.h"
17#include "clang/AST/DeclVisitor.h"
18#include "clang/AST/DependentDiagnostic.h"
19#include "clang/AST/Expr.h"
20#include "clang/AST/ExprCXX.h"
21#include "clang/AST/TypeLoc.h"
22#include "clang/Basic/PrettyStackTrace.h"
23#include "clang/Lex/Preprocessor.h"
24
25using namespace clang;
26
27namespace {
28  class TemplateDeclInstantiator
29    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
30    Sema &SemaRef;
31    DeclContext *Owner;
32    const MultiLevelTemplateArgumentList &TemplateArgs;
33
34    void InstantiateAttrs(Decl *Tmpl, Decl *New);
35
36  public:
37    typedef Sema::OwningExprResult OwningExprResult;
38
39    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
40                             const MultiLevelTemplateArgumentList &TemplateArgs)
41      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
42
43    // FIXME: Once we get closer to completion, replace these manually-written
44    // declarations with automatically-generated ones from
45    // clang/AST/DeclNodes.def.
46    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
47    Decl *VisitNamespaceDecl(NamespaceDecl *D);
48    Decl *VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
49    Decl *VisitTypedefDecl(TypedefDecl *D);
50    Decl *VisitVarDecl(VarDecl *D);
51    Decl *VisitFieldDecl(FieldDecl *D);
52    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
53    Decl *VisitEnumDecl(EnumDecl *D);
54    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
55    Decl *VisitFriendDecl(FriendDecl *D);
56    Decl *VisitFunctionDecl(FunctionDecl *D,
57                            TemplateParameterList *TemplateParams = 0);
58    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
59    Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
60                             TemplateParameterList *TemplateParams = 0);
61    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
62    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
63    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
64    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
65    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
66    Decl *VisitClassTemplatePartialSpecializationDecl(
67                                    ClassTemplatePartialSpecializationDecl *D);
68    Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
69    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
70    Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
71    Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
72    Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
73    Decl *VisitUsingDecl(UsingDecl *D);
74    Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
75    Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
76    Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
77
78    // Base case. FIXME: Remove once we can instantiate everything.
79    Decl *VisitDecl(Decl *D) {
80      unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
81                                                            Diagnostic::Error,
82                                                   "cannot instantiate %0 yet");
83      SemaRef.Diag(D->getLocation(), DiagID)
84        << D->getDeclKindName();
85
86      return 0;
87    }
88
89    const LangOptions &getLangOptions() {
90      return SemaRef.getLangOptions();
91    }
92
93    // Helper functions for instantiating methods.
94    TypeSourceInfo *SubstFunctionType(FunctionDecl *D,
95                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
96    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
97    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
98
99    TemplateParameterList *
100      SubstTemplateParams(TemplateParameterList *List);
101
102    bool SubstQualifier(const DeclaratorDecl *OldDecl,
103                        DeclaratorDecl *NewDecl);
104    bool SubstQualifier(const TagDecl *OldDecl,
105                        TagDecl *NewDecl);
106
107    bool InstantiateClassTemplatePartialSpecialization(
108                                              ClassTemplateDecl *ClassTemplate,
109                           ClassTemplatePartialSpecializationDecl *PartialSpec);
110  };
111}
112
113bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
114                                              DeclaratorDecl *NewDecl) {
115  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
116  if (!OldQual) return false;
117
118  SourceRange QualRange = OldDecl->getQualifierRange();
119
120  NestedNameSpecifier *NewQual
121    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
122  if (!NewQual)
123    return true;
124
125  NewDecl->setQualifierInfo(NewQual, QualRange);
126  return false;
127}
128
129bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
130                                              TagDecl *NewDecl) {
131  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
132  if (!OldQual) return false;
133
134  SourceRange QualRange = OldDecl->getQualifierRange();
135
136  NestedNameSpecifier *NewQual
137    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
138  if (!NewQual)
139    return true;
140
141  NewDecl->setQualifierInfo(NewQual, QualRange);
142  return false;
143}
144
145// FIXME: Is this too simple?
146void TemplateDeclInstantiator::InstantiateAttrs(Decl *Tmpl, Decl *New) {
147  for (const Attr *TmplAttr = Tmpl->getAttrs(); TmplAttr;
148       TmplAttr = TmplAttr->getNext()) {
149
150    // FIXME: Is cloning correct for all attributes?
151    Attr *NewAttr = TmplAttr->clone(SemaRef.Context);
152
153    New->addAttr(NewAttr);
154  }
155}
156
157Decl *
158TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
159  assert(false && "Translation units cannot be instantiated");
160  return D;
161}
162
163Decl *
164TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
165  assert(false && "Namespaces cannot be instantiated");
166  return D;
167}
168
169Decl *
170TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
171  NamespaceAliasDecl *Inst
172    = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
173                                 D->getNamespaceLoc(),
174                                 D->getAliasLoc(),
175                                 D->getNamespace()->getIdentifier(),
176                                 D->getQualifierRange(),
177                                 D->getQualifier(),
178                                 D->getTargetNameLoc(),
179                                 D->getNamespace());
180  Owner->addDecl(Inst);
181  return Inst;
182}
183
184Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
185  bool Invalid = false;
186  TypeSourceInfo *DI = D->getTypeSourceInfo();
187  if (DI->getType()->isDependentType()) {
188    DI = SemaRef.SubstType(DI, TemplateArgs,
189                           D->getLocation(), D->getDeclName());
190    if (!DI) {
191      Invalid = true;
192      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
193    }
194  } else {
195    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
196  }
197
198  // Create the new typedef
199  TypedefDecl *Typedef
200    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
201                          D->getIdentifier(), DI);
202  if (Invalid)
203    Typedef->setInvalidDecl();
204
205  if (const TagType *TT = DI->getType()->getAs<TagType>()) {
206    TagDecl *TD = TT->getDecl();
207
208    // If the TagDecl that the TypedefDecl points to is an anonymous decl
209    // keep track of the TypedefDecl.
210    if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl())
211      TD->setTypedefForAnonDecl(Typedef);
212  }
213
214  if (TypedefDecl *Prev = D->getPreviousDeclaration()) {
215    NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
216                                                       TemplateArgs);
217    Typedef->setPreviousDeclaration(cast<TypedefDecl>(InstPrev));
218  }
219
220  InstantiateAttrs(D, Typedef);
221
222  Typedef->setAccess(D->getAccess());
223  Owner->addDecl(Typedef);
224
225  return Typedef;
226}
227
228/// \brief Instantiate the arguments provided as part of initialization.
229///
230/// \returns true if an error occurred, false otherwise.
231static bool InstantiateInitializationArguments(Sema &SemaRef,
232                                               Expr **Args, unsigned NumArgs,
233                           const MultiLevelTemplateArgumentList &TemplateArgs,
234                         llvm::SmallVectorImpl<SourceLocation> &FakeCommaLocs,
235                           ASTOwningVector<&ActionBase::DeleteExpr> &InitArgs) {
236  for (unsigned I = 0; I != NumArgs; ++I) {
237    // When we hit the first defaulted argument, break out of the loop:
238    // we don't pass those default arguments on.
239    if (Args[I]->isDefaultArgument())
240      break;
241
242    Sema::OwningExprResult Arg = SemaRef.SubstExpr(Args[I], TemplateArgs);
243    if (Arg.isInvalid())
244      return true;
245
246    Expr *ArgExpr = (Expr *)Arg.get();
247    InitArgs.push_back(Arg.release());
248
249    // FIXME: We're faking all of the comma locations. Do we need them?
250    FakeCommaLocs.push_back(
251                          SemaRef.PP.getLocForEndOfToken(ArgExpr->getLocEnd()));
252  }
253
254  return false;
255}
256
257/// \brief Instantiate an initializer, breaking it into separate
258/// initialization arguments.
259///
260/// \param S The semantic analysis object.
261///
262/// \param Init The initializer to instantiate.
263///
264/// \param TemplateArgs Template arguments to be substituted into the
265/// initializer.
266///
267/// \param NewArgs Will be filled in with the instantiation arguments.
268///
269/// \returns true if an error occurred, false otherwise
270static bool InstantiateInitializer(Sema &S, Expr *Init,
271                            const MultiLevelTemplateArgumentList &TemplateArgs,
272                                   SourceLocation &LParenLoc,
273                               llvm::SmallVector<SourceLocation, 4> &CommaLocs,
274                             ASTOwningVector<&ActionBase::DeleteExpr> &NewArgs,
275                                   SourceLocation &RParenLoc) {
276  NewArgs.clear();
277  LParenLoc = SourceLocation();
278  RParenLoc = SourceLocation();
279
280  if (!Init)
281    return false;
282
283  if (CXXExprWithTemporaries *ExprTemp = dyn_cast<CXXExprWithTemporaries>(Init))
284    Init = ExprTemp->getSubExpr();
285
286  while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init))
287    Init = Binder->getSubExpr();
288
289  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
290    Init = ICE->getSubExprAsWritten();
291
292  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
293    LParenLoc = ParenList->getLParenLoc();
294    RParenLoc = ParenList->getRParenLoc();
295    return InstantiateInitializationArguments(S, ParenList->getExprs(),
296                                              ParenList->getNumExprs(),
297                                              TemplateArgs, CommaLocs,
298                                              NewArgs);
299  }
300
301  if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) {
302    if (!isa<CXXTemporaryObjectExpr>(Construct)) {
303      if (InstantiateInitializationArguments(S,
304                                             Construct->getArgs(),
305                                             Construct->getNumArgs(),
306                                             TemplateArgs,
307                                             CommaLocs, NewArgs))
308        return true;
309
310      // FIXME: Fake locations!
311      LParenLoc = S.PP.getLocForEndOfToken(Init->getLocStart());
312      RParenLoc = CommaLocs.empty()? LParenLoc : CommaLocs.back();
313      return false;
314    }
315  }
316
317  Sema::OwningExprResult Result = S.SubstExpr(Init, TemplateArgs);
318  if (Result.isInvalid())
319    return true;
320
321  NewArgs.push_back(Result.takeAs<Expr>());
322  return false;
323}
324
325Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
326  // Do substitution on the type of the declaration
327  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
328                                         TemplateArgs,
329                                         D->getTypeSpecStartLoc(),
330                                         D->getDeclName());
331  if (!DI)
332    return 0;
333
334  // Build the instantiated declaration
335  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
336                                 D->getLocation(), D->getIdentifier(),
337                                 DI->getType(), DI,
338                                 D->getStorageClass(),
339                                 D->getStorageClassAsWritten());
340  Var->setThreadSpecified(D->isThreadSpecified());
341  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
342  Var->setDeclaredInCondition(D->isDeclaredInCondition());
343
344  // Substitute the nested name specifier, if any.
345  if (SubstQualifier(D, Var))
346    return 0;
347
348  // If we are instantiating a static data member defined
349  // out-of-line, the instantiation will have the same lexical
350  // context (which will be a namespace scope) as the template.
351  if (D->isOutOfLine())
352    Var->setLexicalDeclContext(D->getLexicalDeclContext());
353
354  Var->setAccess(D->getAccess());
355  Var->setUsed(D->isUsed());
356
357  // FIXME: In theory, we could have a previous declaration for variables that
358  // are not static data members.
359  bool Redeclaration = false;
360  // FIXME: having to fake up a LookupResult is dumb.
361  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
362                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
363  if (D->isStaticDataMember())
364    SemaRef.LookupQualifiedName(Previous, Owner, false);
365  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
366
367  if (D->isOutOfLine()) {
368    D->getLexicalDeclContext()->addDecl(Var);
369    Owner->makeDeclVisibleInContext(Var);
370  } else {
371    Owner->addDecl(Var);
372
373    if (Owner->isFunctionOrMethod())
374      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Var);
375  }
376
377  // Link instantiations of static data members back to the template from
378  // which they were instantiated.
379  if (Var->isStaticDataMember())
380    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
381                                                     TSK_ImplicitInstantiation);
382
383  if (Var->getAnyInitializer()) {
384    // We already have an initializer in the class.
385  } else if (D->getInit()) {
386    if (Var->isStaticDataMember() && !D->isOutOfLine())
387      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
388    else
389      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
390
391    // Instantiate the initializer.
392    SourceLocation LParenLoc, RParenLoc;
393    llvm::SmallVector<SourceLocation, 4> CommaLocs;
394    ASTOwningVector<&ActionBase::DeleteExpr> InitArgs(SemaRef);
395    if (!InstantiateInitializer(SemaRef, D->getInit(), TemplateArgs, LParenLoc,
396                                CommaLocs, InitArgs, RParenLoc)) {
397      // Attach the initializer to the declaration.
398      if (D->hasCXXDirectInitializer()) {
399        // Add the direct initializer to the declaration.
400        SemaRef.AddCXXDirectInitializerToDecl(Sema::DeclPtrTy::make(Var),
401                                              LParenLoc,
402                                              move_arg(InitArgs),
403                                              CommaLocs.data(),
404                                              RParenLoc);
405      } else if (InitArgs.size() == 1) {
406        Expr *Init = (Expr*)(InitArgs.take()[0]);
407        SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var),
408                                     SemaRef.Owned(Init),
409                                     false);
410      } else {
411        assert(InitArgs.size() == 0);
412        SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
413      }
414    } else {
415      // FIXME: Not too happy about invalidating the declaration
416      // because of a bogus initializer.
417      Var->setInvalidDecl();
418    }
419
420    SemaRef.PopExpressionEvaluationContext();
421  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
422    SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
423
424  // Diagnose unused local variables.
425  if (!Var->isInvalidDecl() && Owner->isFunctionOrMethod() && !Var->isUsed())
426    SemaRef.DiagnoseUnusedDecl(Var);
427
428  return Var;
429}
430
431Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
432  bool Invalid = false;
433  TypeSourceInfo *DI = D->getTypeSourceInfo();
434  if (DI->getType()->isDependentType())  {
435    DI = SemaRef.SubstType(DI, TemplateArgs,
436                           D->getLocation(), D->getDeclName());
437    if (!DI) {
438      DI = D->getTypeSourceInfo();
439      Invalid = true;
440    } else if (DI->getType()->isFunctionType()) {
441      // C++ [temp.arg.type]p3:
442      //   If a declaration acquires a function type through a type
443      //   dependent on a template-parameter and this causes a
444      //   declaration that does not use the syntactic form of a
445      //   function declarator to have function type, the program is
446      //   ill-formed.
447      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
448        << DI->getType();
449      Invalid = true;
450    }
451  } else {
452    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
453  }
454
455  Expr *BitWidth = D->getBitWidth();
456  if (Invalid)
457    BitWidth = 0;
458  else if (BitWidth) {
459    // The bit-width expression is not potentially evaluated.
460    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
461
462    OwningExprResult InstantiatedBitWidth
463      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
464    if (InstantiatedBitWidth.isInvalid()) {
465      Invalid = true;
466      BitWidth = 0;
467    } else
468      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
469  }
470
471  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
472                                            DI->getType(), DI,
473                                            cast<RecordDecl>(Owner),
474                                            D->getLocation(),
475                                            D->isMutable(),
476                                            BitWidth,
477                                            D->getTypeSpecStartLoc(),
478                                            D->getAccess(),
479                                            0);
480  if (!Field) {
481    cast<Decl>(Owner)->setInvalidDecl();
482    return 0;
483  }
484
485  InstantiateAttrs(D, Field);
486
487  if (Invalid)
488    Field->setInvalidDecl();
489
490  if (!Field->getDeclName()) {
491    // Keep track of where this decl came from.
492    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
493  }
494
495  Field->setImplicit(D->isImplicit());
496  Field->setAccess(D->getAccess());
497  Owner->addDecl(Field);
498
499  return Field;
500}
501
502Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
503  // Handle friend type expressions by simply substituting template
504  // parameters into the pattern type and checking the result.
505  if (TypeSourceInfo *Ty = D->getFriendType()) {
506    TypeSourceInfo *InstTy =
507      SemaRef.SubstType(Ty, TemplateArgs,
508                        D->getLocation(), DeclarationName());
509    if (!InstTy)
510      return 0;
511
512    FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getFriendLoc(), InstTy);
513    if (!FD)
514      return 0;
515
516    FD->setAccess(AS_public);
517    Owner->addDecl(FD);
518    return FD;
519  }
520
521  NamedDecl *ND = D->getFriendDecl();
522  assert(ND && "friend decl must be a decl or a type!");
523
524  // All of the Visit implementations for the various potential friend
525  // declarations have to be carefully written to work for friend
526  // objects, with the most important detail being that the target
527  // decl should almost certainly not be placed in Owner.
528  Decl *NewND = Visit(ND);
529  if (!NewND) return 0;
530
531  FriendDecl *FD =
532    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
533                       cast<NamedDecl>(NewND), D->getFriendLoc());
534  FD->setAccess(AS_public);
535  Owner->addDecl(FD);
536  return FD;
537}
538
539Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
540  Expr *AssertExpr = D->getAssertExpr();
541
542  // The expression in a static assertion is not potentially evaluated.
543  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
544
545  OwningExprResult InstantiatedAssertExpr
546    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
547  if (InstantiatedAssertExpr.isInvalid())
548    return 0;
549
550  OwningExprResult Message(SemaRef, D->getMessage());
551  D->getMessage()->Retain();
552  Decl *StaticAssert
553    = SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
554                                           move(InstantiatedAssertExpr),
555                                           move(Message)).getAs<Decl>();
556  return StaticAssert;
557}
558
559Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
560  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
561                                    D->getLocation(), D->getIdentifier(),
562                                    D->getTagKeywordLoc(),
563                                    /*PrevDecl=*/0);
564  Enum->setInstantiationOfMemberEnum(D);
565  Enum->setAccess(D->getAccess());
566  if (SubstQualifier(D, Enum)) return 0;
567  Owner->addDecl(Enum);
568  Enum->startDefinition();
569
570  if (D->getDeclContext()->isFunctionOrMethod())
571    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
572
573  llvm::SmallVector<Sema::DeclPtrTy, 4> Enumerators;
574
575  EnumConstantDecl *LastEnumConst = 0;
576  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
577         ECEnd = D->enumerator_end();
578       EC != ECEnd; ++EC) {
579    // The specified value for the enumerator.
580    OwningExprResult Value = SemaRef.Owned((Expr *)0);
581    if (Expr *UninstValue = EC->getInitExpr()) {
582      // The enumerator's value expression is not potentially evaluated.
583      EnterExpressionEvaluationContext Unevaluated(SemaRef,
584                                                   Action::Unevaluated);
585
586      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
587    }
588
589    // Drop the initial value and continue.
590    bool isInvalid = false;
591    if (Value.isInvalid()) {
592      Value = SemaRef.Owned((Expr *)0);
593      isInvalid = true;
594    }
595
596    EnumConstantDecl *EnumConst
597      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
598                                  EC->getLocation(), EC->getIdentifier(),
599                                  move(Value));
600
601    if (isInvalid) {
602      if (EnumConst)
603        EnumConst->setInvalidDecl();
604      Enum->setInvalidDecl();
605    }
606
607    if (EnumConst) {
608      EnumConst->setAccess(Enum->getAccess());
609      Enum->addDecl(EnumConst);
610      Enumerators.push_back(Sema::DeclPtrTy::make(EnumConst));
611      LastEnumConst = EnumConst;
612
613      if (D->getDeclContext()->isFunctionOrMethod()) {
614        // If the enumeration is within a function or method, record the enum
615        // constant as a local.
616        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
617      }
618    }
619  }
620
621  // FIXME: Fixup LBraceLoc and RBraceLoc
622  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
623  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
624                        Sema::DeclPtrTy::make(Enum),
625                        &Enumerators[0], Enumerators.size(),
626                        0, 0);
627
628  return Enum;
629}
630
631Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
632  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
633  return 0;
634}
635
636Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
637  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
638
639  // Create a local instantiation scope for this class template, which
640  // will contain the instantiations of the template parameters.
641  Sema::LocalInstantiationScope Scope(SemaRef);
642  TemplateParameterList *TempParams = D->getTemplateParameters();
643  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
644  if (!InstParams)
645    return NULL;
646
647  CXXRecordDecl *Pattern = D->getTemplatedDecl();
648
649  // Instantiate the qualifier.  We have to do this first in case
650  // we're a friend declaration, because if we are then we need to put
651  // the new declaration in the appropriate context.
652  NestedNameSpecifier *Qualifier = Pattern->getQualifier();
653  if (Qualifier) {
654    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
655                                                 Pattern->getQualifierRange(),
656                                                 TemplateArgs);
657    if (!Qualifier) return 0;
658  }
659
660  CXXRecordDecl *PrevDecl = 0;
661  ClassTemplateDecl *PrevClassTemplate = 0;
662
663  // If this isn't a friend, then it's a member template, in which
664  // case we just want to build the instantiation in the
665  // specialization.  If it is a friend, we want to build it in
666  // the appropriate context.
667  DeclContext *DC = Owner;
668  if (isFriend) {
669    if (Qualifier) {
670      CXXScopeSpec SS;
671      SS.setScopeRep(Qualifier);
672      SS.setRange(Pattern->getQualifierRange());
673      DC = SemaRef.computeDeclContext(SS);
674      if (!DC) return 0;
675    } else {
676      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
677                                           Pattern->getDeclContext(),
678                                           TemplateArgs);
679    }
680
681    // Look for a previous declaration of the template in the owning
682    // context.
683    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
684                   Sema::LookupOrdinaryName, Sema::ForRedeclaration);
685    SemaRef.LookupQualifiedName(R, DC);
686
687    if (R.isSingleResult()) {
688      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
689      if (PrevClassTemplate)
690        PrevDecl = PrevClassTemplate->getTemplatedDecl();
691    }
692
693    if (!PrevClassTemplate && Qualifier) {
694      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
695        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
696        << Pattern->getQualifierRange();
697      return 0;
698    }
699
700    bool AdoptedPreviousTemplateParams = false;
701    if (PrevClassTemplate) {
702      bool Complain = true;
703
704      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
705      // template for struct std::tr1::__detail::_Map_base, where the
706      // template parameters of the friend declaration don't match the
707      // template parameters of the original declaration. In this one
708      // case, we don't complain about the ill-formed friend
709      // declaration.
710      if (isFriend && Pattern->getIdentifier() &&
711          Pattern->getIdentifier()->isStr("_Map_base") &&
712          DC->isNamespace() &&
713          cast<NamespaceDecl>(DC)->getIdentifier() &&
714          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
715        DeclContext *DCParent = DC->getParent();
716        if (DCParent->isNamespace() &&
717            cast<NamespaceDecl>(DCParent)->getIdentifier() &&
718            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
719          DeclContext *DCParent2 = DCParent->getParent();
720          if (DCParent2->isNamespace() &&
721              cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
722              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
723              DCParent2->getParent()->isTranslationUnit())
724            Complain = false;
725        }
726      }
727
728      TemplateParameterList *PrevParams
729        = PrevClassTemplate->getTemplateParameters();
730
731      // Make sure the parameter lists match.
732      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
733                                                  Complain,
734                                                  Sema::TPL_TemplateMatch)) {
735        if (Complain)
736          return 0;
737
738        AdoptedPreviousTemplateParams = true;
739        InstParams = PrevParams;
740      }
741
742      // Do some additional validation, then merge default arguments
743      // from the existing declarations.
744      if (!AdoptedPreviousTemplateParams &&
745          SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
746                                             Sema::TPC_ClassTemplate))
747        return 0;
748    }
749  }
750
751  CXXRecordDecl *RecordInst
752    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
753                            Pattern->getLocation(), Pattern->getIdentifier(),
754                            Pattern->getTagKeywordLoc(), PrevDecl,
755                            /*DelayTypeCreation=*/true);
756
757  if (Qualifier)
758    RecordInst->setQualifierInfo(Qualifier, Pattern->getQualifierRange());
759
760  ClassTemplateDecl *Inst
761    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
762                                D->getIdentifier(), InstParams, RecordInst,
763                                PrevClassTemplate);
764  RecordInst->setDescribedClassTemplate(Inst);
765
766  if (isFriend) {
767    if (PrevClassTemplate)
768      Inst->setAccess(PrevClassTemplate->getAccess());
769    else
770      Inst->setAccess(D->getAccess());
771
772    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
773    // TODO: do we want to track the instantiation progeny of this
774    // friend target decl?
775  } else {
776    Inst->setAccess(D->getAccess());
777    Inst->setInstantiatedFromMemberTemplate(D);
778  }
779
780  // Trigger creation of the type for the instantiation.
781  SemaRef.Context.getInjectedClassNameType(RecordInst,
782                  Inst->getInjectedClassNameSpecialization(SemaRef.Context));
783
784  // Finish handling of friends.
785  if (isFriend) {
786    DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
787    return Inst;
788  }
789
790  Owner->addDecl(Inst);
791
792  // Instantiate all of the partial specializations of this member class
793  // template.
794  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
795  D->getPartialSpecializations(PartialSpecs);
796  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
797    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
798
799  return Inst;
800}
801
802Decl *
803TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
804                                   ClassTemplatePartialSpecializationDecl *D) {
805  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
806
807  // Lookup the already-instantiated declaration in the instantiation
808  // of the class template and return that.
809  DeclContext::lookup_result Found
810    = Owner->lookup(ClassTemplate->getDeclName());
811  if (Found.first == Found.second)
812    return 0;
813
814  ClassTemplateDecl *InstClassTemplate
815    = dyn_cast<ClassTemplateDecl>(*Found.first);
816  if (!InstClassTemplate)
817    return 0;
818
819  Decl *DCanon = D->getCanonicalDecl();
820  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
821            P = InstClassTemplate->getPartialSpecializations().begin(),
822         PEnd = InstClassTemplate->getPartialSpecializations().end();
823       P != PEnd; ++P) {
824    if (P->getInstantiatedFromMember()->getCanonicalDecl() == DCanon)
825      return &*P;
826  }
827
828  return 0;
829}
830
831Decl *
832TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
833  // Create a local instantiation scope for this function template, which
834  // will contain the instantiations of the template parameters and then get
835  // merged with the local instantiation scope for the function template
836  // itself.
837  Sema::LocalInstantiationScope Scope(SemaRef);
838
839  TemplateParameterList *TempParams = D->getTemplateParameters();
840  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
841  if (!InstParams)
842    return NULL;
843
844  FunctionDecl *Instantiated = 0;
845  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
846    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
847                                                                 InstParams));
848  else
849    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
850                                                          D->getTemplatedDecl(),
851                                                                InstParams));
852
853  if (!Instantiated)
854    return 0;
855
856  Instantiated->setAccess(D->getAccess());
857
858  // Link the instantiated function template declaration to the function
859  // template from which it was instantiated.
860  FunctionTemplateDecl *InstTemplate
861    = Instantiated->getDescribedFunctionTemplate();
862  InstTemplate->setAccess(D->getAccess());
863  assert(InstTemplate &&
864         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
865
866  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
867
868  // Link the instantiation back to the pattern *unless* this is a
869  // non-definition friend declaration.
870  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
871      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
872    InstTemplate->setInstantiatedFromMemberTemplate(D);
873
874  // Make declarations visible in the appropriate context.
875  if (!isFriend)
876    Owner->addDecl(InstTemplate);
877
878  return InstTemplate;
879}
880
881Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
882  CXXRecordDecl *PrevDecl = 0;
883  if (D->isInjectedClassName())
884    PrevDecl = cast<CXXRecordDecl>(Owner);
885  else if (D->getPreviousDeclaration()) {
886    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
887                                                   D->getPreviousDeclaration(),
888                                                   TemplateArgs);
889    if (!Prev) return 0;
890    PrevDecl = cast<CXXRecordDecl>(Prev);
891  }
892
893  CXXRecordDecl *Record
894    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
895                            D->getLocation(), D->getIdentifier(),
896                            D->getTagKeywordLoc(), PrevDecl);
897
898  // Substitute the nested name specifier, if any.
899  if (SubstQualifier(D, Record))
900    return 0;
901
902  Record->setImplicit(D->isImplicit());
903  // FIXME: Check against AS_none is an ugly hack to work around the issue that
904  // the tag decls introduced by friend class declarations don't have an access
905  // specifier. Remove once this area of the code gets sorted out.
906  if (D->getAccess() != AS_none)
907    Record->setAccess(D->getAccess());
908  if (!D->isInjectedClassName())
909    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
910
911  // If the original function was part of a friend declaration,
912  // inherit its namespace state.
913  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
914    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
915
916  Record->setAnonymousStructOrUnion(D->isAnonymousStructOrUnion());
917
918  Owner->addDecl(Record);
919  return Record;
920}
921
922/// Normal class members are of more specific types and therefore
923/// don't make it here.  This function serves two purposes:
924///   1) instantiating function templates
925///   2) substituting friend declarations
926/// FIXME: preserve function definitions in case #2
927Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
928                                       TemplateParameterList *TemplateParams) {
929  // Check whether there is already a function template specialization for
930  // this declaration.
931  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
932  void *InsertPos = 0;
933  if (FunctionTemplate && !TemplateParams) {
934    llvm::FoldingSetNodeID ID;
935    FunctionTemplateSpecializationInfo::Profile(ID,
936                             TemplateArgs.getInnermost().getFlatArgumentList(),
937                                       TemplateArgs.getInnermost().flat_size(),
938                                                SemaRef.Context);
939
940    FunctionTemplateSpecializationInfo *Info
941      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
942                                                                   InsertPos);
943
944    // If we already have a function template specialization, return it.
945    if (Info)
946      return Info->Function;
947  }
948
949  bool isFriend;
950  if (FunctionTemplate)
951    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
952  else
953    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
954
955  bool MergeWithParentScope = (TemplateParams != 0) ||
956    !(isa<Decl>(Owner) &&
957      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
958  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
959
960  llvm::SmallVector<ParmVarDecl *, 4> Params;
961  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
962  TInfo = SubstFunctionType(D, Params);
963  if (!TInfo)
964    return 0;
965  QualType T = TInfo->getType();
966
967  NestedNameSpecifier *Qualifier = D->getQualifier();
968  if (Qualifier) {
969    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
970                                                 D->getQualifierRange(),
971                                                 TemplateArgs);
972    if (!Qualifier) return 0;
973  }
974
975  // If we're instantiating a local function declaration, put the result
976  // in the owner;  otherwise we need to find the instantiated context.
977  DeclContext *DC;
978  if (D->getDeclContext()->isFunctionOrMethod())
979    DC = Owner;
980  else if (isFriend && Qualifier) {
981    CXXScopeSpec SS;
982    SS.setScopeRep(Qualifier);
983    SS.setRange(D->getQualifierRange());
984    DC = SemaRef.computeDeclContext(SS);
985    if (!DC) return 0;
986  } else {
987    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
988                                         TemplateArgs);
989  }
990
991  FunctionDecl *Function =
992      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
993                           D->getDeclName(), T, TInfo,
994                           D->getStorageClass(), D->getStorageClassAsWritten(),
995                           D->isInlineSpecified(), D->hasWrittenPrototype());
996
997  if (Qualifier)
998    Function->setQualifierInfo(Qualifier, D->getQualifierRange());
999
1000  DeclContext *LexicalDC = Owner;
1001  if (!isFriend && D->isOutOfLine()) {
1002    assert(D->getDeclContext()->isFileContext());
1003    LexicalDC = D->getDeclContext();
1004  }
1005
1006  Function->setLexicalDeclContext(LexicalDC);
1007
1008  // Attach the parameters
1009  for (unsigned P = 0; P < Params.size(); ++P)
1010    Params[P]->setOwningFunction(Function);
1011  Function->setParams(Params.data(), Params.size());
1012
1013  SourceLocation InstantiateAtPOI;
1014  if (TemplateParams) {
1015    // Our resulting instantiation is actually a function template, since we
1016    // are substituting only the outer template parameters. For example, given
1017    //
1018    //   template<typename T>
1019    //   struct X {
1020    //     template<typename U> friend void f(T, U);
1021    //   };
1022    //
1023    //   X<int> x;
1024    //
1025    // We are instantiating the friend function template "f" within X<int>,
1026    // which means substituting int for T, but leaving "f" as a friend function
1027    // template.
1028    // Build the function template itself.
1029    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1030                                                    Function->getLocation(),
1031                                                    Function->getDeclName(),
1032                                                    TemplateParams, Function);
1033    Function->setDescribedFunctionTemplate(FunctionTemplate);
1034
1035    FunctionTemplate->setLexicalDeclContext(LexicalDC);
1036
1037    if (isFriend && D->isThisDeclarationADefinition()) {
1038      // TODO: should we remember this connection regardless of whether
1039      // the friend declaration provided a body?
1040      FunctionTemplate->setInstantiatedFromMemberTemplate(
1041                                           D->getDescribedFunctionTemplate());
1042    }
1043  } else if (FunctionTemplate) {
1044    // Record this function template specialization.
1045    Function->setFunctionTemplateSpecialization(FunctionTemplate,
1046                                                &TemplateArgs.getInnermost(),
1047                                                InsertPos);
1048  } else if (isFriend && D->isThisDeclarationADefinition()) {
1049    // TODO: should we remember this connection regardless of whether
1050    // the friend declaration provided a body?
1051    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1052  }
1053
1054  if (InitFunctionInstantiation(Function, D))
1055    Function->setInvalidDecl();
1056
1057  bool Redeclaration = false;
1058  bool OverloadableAttrRequired = false;
1059  bool isExplicitSpecialization = false;
1060
1061  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1062                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1063
1064  if (DependentFunctionTemplateSpecializationInfo *Info
1065        = D->getDependentSpecializationInfo()) {
1066    assert(isFriend && "non-friend has dependent specialization info?");
1067
1068    // This needs to be set now for future sanity.
1069    Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1070
1071    // Instantiate the explicit template arguments.
1072    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1073                                          Info->getRAngleLoc());
1074    for (unsigned I = 0, E = Info->getNumTemplateArgs(); I != E; ++I) {
1075      TemplateArgumentLoc Loc;
1076      if (SemaRef.Subst(Info->getTemplateArg(I), Loc, TemplateArgs))
1077        return 0;
1078
1079      ExplicitArgs.addArgument(Loc);
1080    }
1081
1082    // Map the candidate templates to their instantiations.
1083    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1084      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1085                                                Info->getTemplate(I),
1086                                                TemplateArgs);
1087      if (!Temp) return 0;
1088
1089      Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1090    }
1091
1092    if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1093                                                    &ExplicitArgs,
1094                                                    Previous))
1095      Function->setInvalidDecl();
1096
1097    isExplicitSpecialization = true;
1098
1099  } else if (TemplateParams || !FunctionTemplate) {
1100    // Look only into the namespace where the friend would be declared to
1101    // find a previous declaration. This is the innermost enclosing namespace,
1102    // as described in ActOnFriendFunctionDecl.
1103    SemaRef.LookupQualifiedName(Previous, DC);
1104
1105    // In C++, the previous declaration we find might be a tag type
1106    // (class or enum). In this case, the new declaration will hide the
1107    // tag type. Note that this does does not apply if we're declaring a
1108    // typedef (C++ [dcl.typedef]p4).
1109    if (Previous.isSingleTagDecl())
1110      Previous.clear();
1111  }
1112
1113  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1114                                   isExplicitSpecialization, Redeclaration,
1115                                   /*FIXME:*/OverloadableAttrRequired);
1116
1117  NamedDecl *PrincipalDecl = (TemplateParams
1118                              ? cast<NamedDecl>(FunctionTemplate)
1119                              : Function);
1120
1121  // If the original function was part of a friend declaration,
1122  // inherit its namespace state and add it to the owner.
1123  if (isFriend) {
1124    NamedDecl *PrevDecl;
1125    if (TemplateParams)
1126      PrevDecl = FunctionTemplate->getPreviousDeclaration();
1127    else
1128      PrevDecl = Function->getPreviousDeclaration();
1129
1130    PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0);
1131    DC->makeDeclVisibleInContext(PrincipalDecl, /*Recoverable=*/ false);
1132
1133    if (!SemaRef.getLangOptions().CPlusPlus0x &&
1134        D->isThisDeclarationADefinition()) {
1135      // Check for a function body.
1136      const FunctionDecl *Definition = 0;
1137      if (Function->getBody(Definition) &&
1138          Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1139        SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1140          << Function->getDeclName();
1141        SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1142        Function->setInvalidDecl();
1143      }
1144      // Check for redefinitions due to other instantiations of this or
1145      // a similar friend function.
1146      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1147                                           REnd = Function->redecls_end();
1148                R != REnd; ++R) {
1149        if (*R != Function &&
1150            ((*R)->getFriendObjectKind() != Decl::FOK_None)) {
1151          if (const FunctionDecl *RPattern
1152              = (*R)->getTemplateInstantiationPattern())
1153            if (RPattern->getBody(RPattern)) {
1154              SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1155                << Function->getDeclName();
1156              SemaRef.Diag((*R)->getLocation(), diag::note_previous_definition);
1157              Function->setInvalidDecl();
1158              break;
1159            }
1160        }
1161      }
1162    }
1163
1164  }
1165
1166  if (Function->isOverloadedOperator() && !DC->isRecord() &&
1167      PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1168    PrincipalDecl->setNonMemberOperator();
1169
1170  return Function;
1171}
1172
1173Decl *
1174TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1175                                      TemplateParameterList *TemplateParams) {
1176  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1177  void *InsertPos = 0;
1178  if (FunctionTemplate && !TemplateParams) {
1179    // We are creating a function template specialization from a function
1180    // template. Check whether there is already a function template
1181    // specialization for this particular set of template arguments.
1182    llvm::FoldingSetNodeID ID;
1183    FunctionTemplateSpecializationInfo::Profile(ID,
1184                            TemplateArgs.getInnermost().getFlatArgumentList(),
1185                                      TemplateArgs.getInnermost().flat_size(),
1186                                                SemaRef.Context);
1187
1188    FunctionTemplateSpecializationInfo *Info
1189      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
1190                                                                   InsertPos);
1191
1192    // If we already have a function template specialization, return it.
1193    if (Info)
1194      return Info->Function;
1195  }
1196
1197  bool isFriend;
1198  if (FunctionTemplate)
1199    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1200  else
1201    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1202
1203  bool MergeWithParentScope = (TemplateParams != 0) ||
1204    !(isa<Decl>(Owner) &&
1205      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1206  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1207
1208  llvm::SmallVector<ParmVarDecl *, 4> Params;
1209  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1210  TInfo = SubstFunctionType(D, Params);
1211  if (!TInfo)
1212    return 0;
1213  QualType T = TInfo->getType();
1214
1215  // \brief If the type of this function is not *directly* a function
1216  // type, then we're instantiating the a function that was declared
1217  // via a typedef, e.g.,
1218  //
1219  //   typedef int functype(int, int);
1220  //   functype func;
1221  //
1222  // In this case, we'll just go instantiate the ParmVarDecls that we
1223  // synthesized in the method declaration.
1224  if (!isa<FunctionProtoType>(T)) {
1225    assert(!Params.size() && "Instantiating type could not yield parameters");
1226    for (unsigned I = 0, N = D->getNumParams(); I != N; ++I) {
1227      ParmVarDecl *P = SemaRef.SubstParmVarDecl(D->getParamDecl(I),
1228                                                TemplateArgs);
1229      if (!P)
1230        return 0;
1231
1232      Params.push_back(P);
1233    }
1234  }
1235
1236  NestedNameSpecifier *Qualifier = D->getQualifier();
1237  if (Qualifier) {
1238    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1239                                                 D->getQualifierRange(),
1240                                                 TemplateArgs);
1241    if (!Qualifier) return 0;
1242  }
1243
1244  DeclContext *DC = Owner;
1245  if (isFriend) {
1246    if (Qualifier) {
1247      CXXScopeSpec SS;
1248      SS.setScopeRep(Qualifier);
1249      SS.setRange(D->getQualifierRange());
1250      DC = SemaRef.computeDeclContext(SS);
1251    } else {
1252      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1253                                           D->getDeclContext(),
1254                                           TemplateArgs);
1255    }
1256    if (!DC) return 0;
1257  }
1258
1259  // Build the instantiated method declaration.
1260  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1261  CXXMethodDecl *Method = 0;
1262
1263  DeclarationName Name = D->getDeclName();
1264  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1265    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1266    Name = SemaRef.Context.DeclarationNames.getCXXConstructorName(
1267                                    SemaRef.Context.getCanonicalType(ClassTy));
1268    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1269                                        Constructor->getLocation(),
1270                                        Name, T, TInfo,
1271                                        Constructor->isExplicit(),
1272                                        Constructor->isInlineSpecified(),
1273                                        false);
1274  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1275    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1276    Name = SemaRef.Context.DeclarationNames.getCXXDestructorName(
1277                                   SemaRef.Context.getCanonicalType(ClassTy));
1278    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1279                                       Destructor->getLocation(), Name,
1280                                       T, Destructor->isInlineSpecified(),
1281                                       false);
1282  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1283    CanQualType ConvTy
1284      = SemaRef.Context.getCanonicalType(
1285                                      T->getAs<FunctionType>()->getResultType());
1286    Name = SemaRef.Context.DeclarationNames.getCXXConversionFunctionName(
1287                                                                      ConvTy);
1288    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1289                                       Conversion->getLocation(), Name,
1290                                       T, TInfo,
1291                                       Conversion->isInlineSpecified(),
1292                                       Conversion->isExplicit());
1293  } else {
1294    Method = CXXMethodDecl::Create(SemaRef.Context, Record, D->getLocation(),
1295                                   D->getDeclName(), T, TInfo,
1296                                   D->isStatic(),
1297                                   D->getStorageClassAsWritten(),
1298                                   D->isInlineSpecified());
1299  }
1300
1301  if (Qualifier)
1302    Method->setQualifierInfo(Qualifier, D->getQualifierRange());
1303
1304  if (TemplateParams) {
1305    // Our resulting instantiation is actually a function template, since we
1306    // are substituting only the outer template parameters. For example, given
1307    //
1308    //   template<typename T>
1309    //   struct X {
1310    //     template<typename U> void f(T, U);
1311    //   };
1312    //
1313    //   X<int> x;
1314    //
1315    // We are instantiating the member template "f" within X<int>, which means
1316    // substituting int for T, but leaving "f" as a member function template.
1317    // Build the function template itself.
1318    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1319                                                    Method->getLocation(),
1320                                                    Method->getDeclName(),
1321                                                    TemplateParams, Method);
1322    if (isFriend) {
1323      FunctionTemplate->setLexicalDeclContext(Owner);
1324      FunctionTemplate->setObjectOfFriendDecl(true);
1325    } else if (D->isOutOfLine())
1326      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1327    Method->setDescribedFunctionTemplate(FunctionTemplate);
1328  } else if (FunctionTemplate) {
1329    // Record this function template specialization.
1330    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1331                                              &TemplateArgs.getInnermost(),
1332                                              InsertPos);
1333  } else if (!isFriend) {
1334    // Record that this is an instantiation of a member function.
1335    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1336  }
1337
1338  // If we are instantiating a member function defined
1339  // out-of-line, the instantiation will have the same lexical
1340  // context (which will be a namespace scope) as the template.
1341  if (isFriend) {
1342    Method->setLexicalDeclContext(Owner);
1343    Method->setObjectOfFriendDecl(true);
1344  } else if (D->isOutOfLine())
1345    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1346
1347  // Attach the parameters
1348  for (unsigned P = 0; P < Params.size(); ++P)
1349    Params[P]->setOwningFunction(Method);
1350  Method->setParams(Params.data(), Params.size());
1351
1352  if (InitMethodInstantiation(Method, D))
1353    Method->setInvalidDecl();
1354
1355  LookupResult Previous(SemaRef, Name, SourceLocation(),
1356                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1357
1358  if (!FunctionTemplate || TemplateParams || isFriend) {
1359    SemaRef.LookupQualifiedName(Previous, Record);
1360
1361    // In C++, the previous declaration we find might be a tag type
1362    // (class or enum). In this case, the new declaration will hide the
1363    // tag type. Note that this does does not apply if we're declaring a
1364    // typedef (C++ [dcl.typedef]p4).
1365    if (Previous.isSingleTagDecl())
1366      Previous.clear();
1367  }
1368
1369  bool Redeclaration = false;
1370  bool OverloadableAttrRequired = false;
1371  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1372                                   /*FIXME:*/OverloadableAttrRequired);
1373
1374  if (D->isPure())
1375    SemaRef.CheckPureMethod(Method, SourceRange());
1376
1377  Method->setAccess(D->getAccess());
1378
1379  if (FunctionTemplate) {
1380    // If there's a function template, let our caller handle it.
1381  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1382    // Don't hide a (potentially) valid declaration with an invalid one.
1383  } else {
1384    NamedDecl *DeclToAdd = (TemplateParams
1385                            ? cast<NamedDecl>(FunctionTemplate)
1386                            : Method);
1387    if (isFriend)
1388      Record->makeDeclVisibleInContext(DeclToAdd);
1389    else
1390      Owner->addDecl(DeclToAdd);
1391  }
1392
1393  return Method;
1394}
1395
1396Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1397  return VisitCXXMethodDecl(D);
1398}
1399
1400Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1401  return VisitCXXMethodDecl(D);
1402}
1403
1404Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1405  return VisitCXXMethodDecl(D);
1406}
1407
1408ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1409  return SemaRef.SubstParmVarDecl(D, TemplateArgs);
1410}
1411
1412Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1413                                                    TemplateTypeParmDecl *D) {
1414  // TODO: don't always clone when decls are refcounted.
1415  const Type* T = D->getTypeForDecl();
1416  assert(T->isTemplateTypeParmType());
1417  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1418
1419  TemplateTypeParmDecl *Inst =
1420    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1421                                 TTPT->getDepth() - 1, TTPT->getIndex(),
1422                                 TTPT->getName(),
1423                                 D->wasDeclaredWithTypename(),
1424                                 D->isParameterPack());
1425
1426  if (D->hasDefaultArgument())
1427    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1428
1429  // Introduce this template parameter's instantiation into the instantiation
1430  // scope.
1431  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1432
1433  return Inst;
1434}
1435
1436Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1437                                                 NonTypeTemplateParmDecl *D) {
1438  // Substitute into the type of the non-type template parameter.
1439  QualType T;
1440  TypeSourceInfo *DI = D->getTypeSourceInfo();
1441  if (DI) {
1442    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1443                           D->getDeclName());
1444    if (DI) T = DI->getType();
1445  } else {
1446    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1447                          D->getDeclName());
1448    DI = 0;
1449  }
1450  if (T.isNull())
1451    return 0;
1452
1453  // Check that this type is acceptable for a non-type template parameter.
1454  bool Invalid = false;
1455  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1456  if (T.isNull()) {
1457    T = SemaRef.Context.IntTy;
1458    Invalid = true;
1459  }
1460
1461  NonTypeTemplateParmDecl *Param
1462    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1463                                      D->getDepth() - 1, D->getPosition(),
1464                                      D->getIdentifier(), T, DI);
1465  if (Invalid)
1466    Param->setInvalidDecl();
1467
1468  Param->setDefaultArgument(D->getDefaultArgument());
1469
1470  // Introduce this template parameter's instantiation into the instantiation
1471  // scope.
1472  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1473  return Param;
1474}
1475
1476Decl *
1477TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1478                                                  TemplateTemplateParmDecl *D) {
1479  // Instantiate the template parameter list of the template template parameter.
1480  TemplateParameterList *TempParams = D->getTemplateParameters();
1481  TemplateParameterList *InstParams;
1482  {
1483    // Perform the actual substitution of template parameters within a new,
1484    // local instantiation scope.
1485    Sema::LocalInstantiationScope Scope(SemaRef);
1486    InstParams = SubstTemplateParams(TempParams);
1487    if (!InstParams)
1488      return NULL;
1489  }
1490
1491  // Build the template template parameter.
1492  TemplateTemplateParmDecl *Param
1493    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1494                                       D->getDepth() - 1, D->getPosition(),
1495                                       D->getIdentifier(), InstParams);
1496  Param->setDefaultArgument(D->getDefaultArgument());
1497
1498  // Introduce this template parameter's instantiation into the instantiation
1499  // scope.
1500  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1501
1502  return Param;
1503}
1504
1505Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1506  // Using directives are never dependent, so they require no explicit
1507
1508  UsingDirectiveDecl *Inst
1509    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1510                                 D->getNamespaceKeyLocation(),
1511                                 D->getQualifierRange(), D->getQualifier(),
1512                                 D->getIdentLocation(),
1513                                 D->getNominatedNamespace(),
1514                                 D->getCommonAncestor());
1515  Owner->addDecl(Inst);
1516  return Inst;
1517}
1518
1519Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1520  // The nested name specifier is non-dependent, so no transformation
1521  // is required.
1522
1523  // We only need to do redeclaration lookups if we're in a class
1524  // scope (in fact, it's not really even possible in non-class
1525  // scopes).
1526  bool CheckRedeclaration = Owner->isRecord();
1527
1528  LookupResult Prev(SemaRef, D->getDeclName(), D->getLocation(),
1529                    Sema::LookupUsingDeclName, Sema::ForRedeclaration);
1530
1531  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1532                                       D->getLocation(),
1533                                       D->getNestedNameRange(),
1534                                       D->getUsingLocation(),
1535                                       D->getTargetNestedNameDecl(),
1536                                       D->getDeclName(),
1537                                       D->isTypeName());
1538
1539  CXXScopeSpec SS;
1540  SS.setScopeRep(D->getTargetNestedNameDecl());
1541  SS.setRange(D->getNestedNameRange());
1542
1543  if (CheckRedeclaration) {
1544    Prev.setHideTags(false);
1545    SemaRef.LookupQualifiedName(Prev, Owner);
1546
1547    // Check for invalid redeclarations.
1548    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1549                                            D->isTypeName(), SS,
1550                                            D->getLocation(), Prev))
1551      NewUD->setInvalidDecl();
1552
1553  }
1554
1555  if (!NewUD->isInvalidDecl() &&
1556      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1557                                      D->getLocation()))
1558    NewUD->setInvalidDecl();
1559
1560  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1561  NewUD->setAccess(D->getAccess());
1562  Owner->addDecl(NewUD);
1563
1564  // Don't process the shadow decls for an invalid decl.
1565  if (NewUD->isInvalidDecl())
1566    return NewUD;
1567
1568  bool isFunctionScope = Owner->isFunctionOrMethod();
1569
1570  // Process the shadow decls.
1571  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1572         I != E; ++I) {
1573    UsingShadowDecl *Shadow = *I;
1574    NamedDecl *InstTarget =
1575      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1576                                                   Shadow->getTargetDecl(),
1577                                                   TemplateArgs));
1578
1579    if (CheckRedeclaration &&
1580        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1581      continue;
1582
1583    UsingShadowDecl *InstShadow
1584      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1585    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1586
1587    if (isFunctionScope)
1588      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1589  }
1590
1591  return NewUD;
1592}
1593
1594Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1595  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1596  return 0;
1597}
1598
1599Decl * TemplateDeclInstantiator
1600    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1601  NestedNameSpecifier *NNS =
1602    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1603                                     D->getTargetNestedNameRange(),
1604                                     TemplateArgs);
1605  if (!NNS)
1606    return 0;
1607
1608  CXXScopeSpec SS;
1609  SS.setRange(D->getTargetNestedNameRange());
1610  SS.setScopeRep(NNS);
1611
1612  NamedDecl *UD =
1613    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1614                                  D->getUsingLoc(), SS, D->getLocation(),
1615                                  D->getDeclName(), 0,
1616                                  /*instantiation*/ true,
1617                                  /*typename*/ true, D->getTypenameLoc());
1618  if (UD)
1619    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1620
1621  return UD;
1622}
1623
1624Decl * TemplateDeclInstantiator
1625    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1626  NestedNameSpecifier *NNS =
1627    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1628                                     D->getTargetNestedNameRange(),
1629                                     TemplateArgs);
1630  if (!NNS)
1631    return 0;
1632
1633  CXXScopeSpec SS;
1634  SS.setRange(D->getTargetNestedNameRange());
1635  SS.setScopeRep(NNS);
1636
1637  NamedDecl *UD =
1638    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1639                                  D->getUsingLoc(), SS, D->getLocation(),
1640                                  D->getDeclName(), 0,
1641                                  /*instantiation*/ true,
1642                                  /*typename*/ false, SourceLocation());
1643  if (UD)
1644    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1645
1646  return UD;
1647}
1648
1649Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1650                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1651  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1652  if (D->isInvalidDecl())
1653    return 0;
1654
1655  return Instantiator.Visit(D);
1656}
1657
1658/// \brief Instantiates a nested template parameter list in the current
1659/// instantiation context.
1660///
1661/// \param L The parameter list to instantiate
1662///
1663/// \returns NULL if there was an error
1664TemplateParameterList *
1665TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1666  // Get errors for all the parameters before bailing out.
1667  bool Invalid = false;
1668
1669  unsigned N = L->size();
1670  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1671  ParamVector Params;
1672  Params.reserve(N);
1673  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1674       PI != PE; ++PI) {
1675    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1676    Params.push_back(D);
1677    Invalid = Invalid || !D || D->isInvalidDecl();
1678  }
1679
1680  // Clean up if we had an error.
1681  if (Invalid) {
1682    for (ParamVector::iterator PI = Params.begin(), PE = Params.end();
1683         PI != PE; ++PI)
1684      if (*PI)
1685        (*PI)->Destroy(SemaRef.Context);
1686    return NULL;
1687  }
1688
1689  TemplateParameterList *InstL
1690    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1691                                    L->getLAngleLoc(), &Params.front(), N,
1692                                    L->getRAngleLoc());
1693  return InstL;
1694}
1695
1696/// \brief Instantiate the declaration of a class template partial
1697/// specialization.
1698///
1699/// \param ClassTemplate the (instantiated) class template that is partially
1700// specialized by the instantiation of \p PartialSpec.
1701///
1702/// \param PartialSpec the (uninstantiated) class template partial
1703/// specialization that we are instantiating.
1704///
1705/// \returns true if there was an error, false otherwise.
1706bool
1707TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1708                                            ClassTemplateDecl *ClassTemplate,
1709                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1710  // Create a local instantiation scope for this class template partial
1711  // specialization, which will contain the instantiations of the template
1712  // parameters.
1713  Sema::LocalInstantiationScope Scope(SemaRef);
1714
1715  // Substitute into the template parameters of the class template partial
1716  // specialization.
1717  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1718  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1719  if (!InstParams)
1720    return true;
1721
1722  // Substitute into the template arguments of the class template partial
1723  // specialization.
1724  const TemplateArgumentLoc *PartialSpecTemplateArgs
1725    = PartialSpec->getTemplateArgsAsWritten();
1726  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1727
1728  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1729  for (unsigned I = 0; I != N; ++I) {
1730    TemplateArgumentLoc Loc;
1731    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1732      return true;
1733    InstTemplateArgs.addArgument(Loc);
1734  }
1735
1736
1737  // Check that the template argument list is well-formed for this
1738  // class template.
1739  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1740                                        InstTemplateArgs.size());
1741  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1742                                        PartialSpec->getLocation(),
1743                                        InstTemplateArgs,
1744                                        false,
1745                                        Converted))
1746    return true;
1747
1748  // Figure out where to insert this class template partial specialization
1749  // in the member template's set of class template partial specializations.
1750  llvm::FoldingSetNodeID ID;
1751  ClassTemplatePartialSpecializationDecl::Profile(ID,
1752                                                  Converted.getFlatArguments(),
1753                                                  Converted.flatSize(),
1754                                                  SemaRef.Context);
1755  void *InsertPos = 0;
1756  ClassTemplateSpecializationDecl *PrevDecl
1757    = ClassTemplate->getPartialSpecializations().FindNodeOrInsertPos(ID,
1758                                                                     InsertPos);
1759
1760  // Build the canonical type that describes the converted template
1761  // arguments of the class template partial specialization.
1762  QualType CanonType
1763    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1764                                                  Converted.getFlatArguments(),
1765                                                    Converted.flatSize());
1766
1767  // Build the fully-sugared type for this class template
1768  // specialization as the user wrote in the specialization
1769  // itself. This means that we'll pretty-print the type retrieved
1770  // from the specialization's declaration the way that the user
1771  // actually wrote the specialization, rather than formatting the
1772  // name based on the "canonical" representation used to store the
1773  // template arguments in the specialization.
1774  TypeSourceInfo *WrittenTy
1775    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1776                                                    TemplateName(ClassTemplate),
1777                                                    PartialSpec->getLocation(),
1778                                                    InstTemplateArgs,
1779                                                    CanonType);
1780
1781  if (PrevDecl) {
1782    // We've already seen a partial specialization with the same template
1783    // parameters and template arguments. This can happen, for example, when
1784    // substituting the outer template arguments ends up causing two
1785    // class template partial specializations of a member class template
1786    // to have identical forms, e.g.,
1787    //
1788    //   template<typename T, typename U>
1789    //   struct Outer {
1790    //     template<typename X, typename Y> struct Inner;
1791    //     template<typename Y> struct Inner<T, Y>;
1792    //     template<typename Y> struct Inner<U, Y>;
1793    //   };
1794    //
1795    //   Outer<int, int> outer; // error: the partial specializations of Inner
1796    //                          // have the same signature.
1797    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1798      << WrittenTy;
1799    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1800      << SemaRef.Context.getTypeDeclType(PrevDecl);
1801    return true;
1802  }
1803
1804
1805  // Create the class template partial specialization declaration.
1806  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1807    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
1808                                                     PartialSpec->getTagKind(),
1809                                                     Owner,
1810                                                     PartialSpec->getLocation(),
1811                                                     InstParams,
1812                                                     ClassTemplate,
1813                                                     Converted,
1814                                                     InstTemplateArgs,
1815                                                     CanonType,
1816                                                     0,
1817                             ClassTemplate->getPartialSpecializations().size());
1818  // Substitute the nested name specifier, if any.
1819  if (SubstQualifier(PartialSpec, InstPartialSpec))
1820    return 0;
1821
1822  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1823  InstPartialSpec->setTypeAsWritten(WrittenTy);
1824
1825  // Add this partial specialization to the set of class template partial
1826  // specializations.
1827  ClassTemplate->getPartialSpecializations().InsertNode(InstPartialSpec,
1828                                                        InsertPos);
1829  return false;
1830}
1831
1832TypeSourceInfo*
1833TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1834                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1835  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1836  assert(OldTInfo && "substituting function without type source info");
1837  assert(Params.empty() && "parameter vector is non-empty at start");
1838  TypeSourceInfo *NewTInfo
1839    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
1840                                    D->getTypeSpecStartLoc(),
1841                                    D->getDeclName());
1842  if (!NewTInfo)
1843    return 0;
1844
1845  if (NewTInfo != OldTInfo) {
1846    // Get parameters from the new type info.
1847    TypeLoc OldTL = OldTInfo->getTypeLoc();
1848    if (FunctionProtoTypeLoc *OldProtoLoc
1849                                  = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1850      TypeLoc NewTL = NewTInfo->getTypeLoc();
1851      FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1852      assert(NewProtoLoc && "Missing prototype?");
1853      for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i) {
1854        // FIXME: Variadic templates will break this.
1855        Params.push_back(NewProtoLoc->getArg(i));
1856        SemaRef.CurrentInstantiationScope->InstantiatedLocal(
1857                                                        OldProtoLoc->getArg(i),
1858                                                        NewProtoLoc->getArg(i));
1859      }
1860    }
1861  } else {
1862    // The function type itself was not dependent and therefore no
1863    // substitution occurred. However, we still need to instantiate
1864    // the function parameters themselves.
1865    TypeLoc OldTL = OldTInfo->getTypeLoc();
1866    if (FunctionProtoTypeLoc *OldProtoLoc
1867                                    = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1868      for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
1869        ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
1870        if (!Parm)
1871          return 0;
1872        Params.push_back(Parm);
1873      }
1874    }
1875  }
1876  return NewTInfo;
1877}
1878
1879/// \brief Initializes the common fields of an instantiation function
1880/// declaration (New) from the corresponding fields of its template (Tmpl).
1881///
1882/// \returns true if there was an error
1883bool
1884TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1885                                                    FunctionDecl *Tmpl) {
1886  if (Tmpl->isDeleted())
1887    New->setDeleted();
1888
1889  // If we are performing substituting explicitly-specified template arguments
1890  // or deduced template arguments into a function template and we reach this
1891  // point, we are now past the point where SFINAE applies and have committed
1892  // to keeping the new function template specialization. We therefore
1893  // convert the active template instantiation for the function template
1894  // into a template instantiation for this specific function template
1895  // specialization, which is not a SFINAE context, so that we diagnose any
1896  // further errors in the declaration itself.
1897  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1898  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1899  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1900      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1901    if (FunctionTemplateDecl *FunTmpl
1902          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1903      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1904             "Deduction from the wrong function template?");
1905      (void) FunTmpl;
1906      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1907      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1908      --SemaRef.NonInstantiationEntries;
1909    }
1910  }
1911
1912  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1913  assert(Proto && "Function template without prototype?");
1914
1915  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1916      Proto->getNoReturnAttr()) {
1917    // The function has an exception specification or a "noreturn"
1918    // attribute. Substitute into each of the exception types.
1919    llvm::SmallVector<QualType, 4> Exceptions;
1920    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1921      // FIXME: Poor location information!
1922      QualType T
1923        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1924                            New->getLocation(), New->getDeclName());
1925      if (T.isNull() ||
1926          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1927        continue;
1928
1929      Exceptions.push_back(T);
1930    }
1931
1932    // Rebuild the function type
1933
1934    const FunctionProtoType *NewProto
1935      = New->getType()->getAs<FunctionProtoType>();
1936    assert(NewProto && "Template instantiation without function prototype?");
1937    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1938                                                 NewProto->arg_type_begin(),
1939                                                 NewProto->getNumArgs(),
1940                                                 NewProto->isVariadic(),
1941                                                 NewProto->getTypeQuals(),
1942                                                 Proto->hasExceptionSpec(),
1943                                                 Proto->hasAnyExceptionSpec(),
1944                                                 Exceptions.size(),
1945                                                 Exceptions.data(),
1946                                                 Proto->getExtInfo()));
1947  }
1948
1949  return false;
1950}
1951
1952/// \brief Initializes common fields of an instantiated method
1953/// declaration (New) from the corresponding fields of its template
1954/// (Tmpl).
1955///
1956/// \returns true if there was an error
1957bool
1958TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
1959                                                  CXXMethodDecl *Tmpl) {
1960  if (InitFunctionInstantiation(New, Tmpl))
1961    return true;
1962
1963  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
1964  New->setAccess(Tmpl->getAccess());
1965  if (Tmpl->isVirtualAsWritten())
1966    Record->setMethodAsVirtual(New);
1967
1968  // FIXME: attributes
1969  // FIXME: New needs a pointer to Tmpl
1970  return false;
1971}
1972
1973/// \brief Instantiate the definition of the given function from its
1974/// template.
1975///
1976/// \param PointOfInstantiation the point at which the instantiation was
1977/// required. Note that this is not precisely a "point of instantiation"
1978/// for the function, but it's close.
1979///
1980/// \param Function the already-instantiated declaration of a
1981/// function template specialization or member function of a class template
1982/// specialization.
1983///
1984/// \param Recursive if true, recursively instantiates any functions that
1985/// are required by this instantiation.
1986///
1987/// \param DefinitionRequired if true, then we are performing an explicit
1988/// instantiation where the body of the function is required. Complain if
1989/// there is no such body.
1990void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
1991                                         FunctionDecl *Function,
1992                                         bool Recursive,
1993                                         bool DefinitionRequired) {
1994  if (Function->isInvalidDecl() || Function->getBody())
1995    return;
1996
1997  // Never instantiate an explicit specialization.
1998  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
1999    return;
2000
2001  // Find the function body that we'll be substituting.
2002  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
2003  Stmt *Pattern = 0;
2004  if (PatternDecl)
2005    Pattern = PatternDecl->getBody(PatternDecl);
2006
2007  if (!Pattern) {
2008    if (DefinitionRequired) {
2009      if (Function->getPrimaryTemplate())
2010        Diag(PointOfInstantiation,
2011             diag::err_explicit_instantiation_undefined_func_template)
2012          << Function->getPrimaryTemplate();
2013      else
2014        Diag(PointOfInstantiation,
2015             diag::err_explicit_instantiation_undefined_member)
2016          << 1 << Function->getDeclName() << Function->getDeclContext();
2017
2018      if (PatternDecl)
2019        Diag(PatternDecl->getLocation(),
2020             diag::note_explicit_instantiation_here);
2021      Function->setInvalidDecl();
2022    }
2023
2024    return;
2025  }
2026
2027  // C++0x [temp.explicit]p9:
2028  //   Except for inline functions, other explicit instantiation declarations
2029  //   have the effect of suppressing the implicit instantiation of the entity
2030  //   to which they refer.
2031  if (Function->getTemplateSpecializationKind()
2032        == TSK_ExplicitInstantiationDeclaration &&
2033      !PatternDecl->isInlined())
2034    return;
2035
2036  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2037  if (Inst)
2038    return;
2039
2040  // If we're performing recursive template instantiation, create our own
2041  // queue of pending implicit instantiations that we will instantiate later,
2042  // while we're still within our own instantiation context.
2043  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2044  if (Recursive)
2045    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2046
2047  EnterExpressionEvaluationContext EvalContext(*this,
2048                                               Action::PotentiallyEvaluated);
2049  ActOnStartOfFunctionDef(0, DeclPtrTy::make(Function));
2050
2051  // Introduce a new scope where local variable instantiations will be
2052  // recorded, unless we're actually a member function within a local
2053  // class, in which case we need to merge our results with the parent
2054  // scope (of the enclosing function).
2055  bool MergeWithParentScope = false;
2056  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2057    MergeWithParentScope = Rec->isLocalClass();
2058
2059  LocalInstantiationScope Scope(*this, MergeWithParentScope);
2060
2061  // Introduce the instantiated function parameters into the local
2062  // instantiation scope.
2063  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I)
2064    Scope.InstantiatedLocal(PatternDecl->getParamDecl(I),
2065                            Function->getParamDecl(I));
2066
2067  // Enter the scope of this instantiation. We don't use
2068  // PushDeclContext because we don't have a scope.
2069  DeclContext *PreviousContext = CurContext;
2070  CurContext = Function;
2071
2072  MultiLevelTemplateArgumentList TemplateArgs =
2073    getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
2074
2075  // If this is a constructor, instantiate the member initializers.
2076  if (const CXXConstructorDecl *Ctor =
2077        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2078    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2079                               TemplateArgs);
2080  }
2081
2082  // Instantiate the function body.
2083  OwningStmtResult Body = SubstStmt(Pattern, TemplateArgs);
2084
2085  if (Body.isInvalid())
2086    Function->setInvalidDecl();
2087
2088  ActOnFinishFunctionBody(DeclPtrTy::make(Function), move(Body),
2089                          /*IsInstantiation=*/true);
2090
2091  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2092
2093  CurContext = PreviousContext;
2094
2095  DeclGroupRef DG(Function);
2096  Consumer.HandleTopLevelDecl(DG);
2097
2098  // This class may have local implicit instantiations that need to be
2099  // instantiation within this scope.
2100  PerformPendingImplicitInstantiations(/*LocalOnly=*/true);
2101  Scope.Exit();
2102
2103  if (Recursive) {
2104    // Instantiate any pending implicit instantiations found during the
2105    // instantiation of this template.
2106    PerformPendingImplicitInstantiations();
2107
2108    // Restore the set of pending implicit instantiations.
2109    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2110  }
2111}
2112
2113/// \brief Instantiate the definition of the given variable from its
2114/// template.
2115///
2116/// \param PointOfInstantiation the point at which the instantiation was
2117/// required. Note that this is not precisely a "point of instantiation"
2118/// for the function, but it's close.
2119///
2120/// \param Var the already-instantiated declaration of a static member
2121/// variable of a class template specialization.
2122///
2123/// \param Recursive if true, recursively instantiates any functions that
2124/// are required by this instantiation.
2125///
2126/// \param DefinitionRequired if true, then we are performing an explicit
2127/// instantiation where an out-of-line definition of the member variable
2128/// is required. Complain if there is no such definition.
2129void Sema::InstantiateStaticDataMemberDefinition(
2130                                          SourceLocation PointOfInstantiation,
2131                                                 VarDecl *Var,
2132                                                 bool Recursive,
2133                                                 bool DefinitionRequired) {
2134  if (Var->isInvalidDecl())
2135    return;
2136
2137  // Find the out-of-line definition of this static data member.
2138  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2139  assert(Def && "This data member was not instantiated from a template?");
2140  assert(Def->isStaticDataMember() && "Not a static data member?");
2141  Def = Def->getOutOfLineDefinition();
2142
2143  if (!Def) {
2144    // We did not find an out-of-line definition of this static data member,
2145    // so we won't perform any instantiation. Rather, we rely on the user to
2146    // instantiate this definition (or provide a specialization for it) in
2147    // another translation unit.
2148    if (DefinitionRequired) {
2149      Def = Var->getInstantiatedFromStaticDataMember();
2150      Diag(PointOfInstantiation,
2151           diag::err_explicit_instantiation_undefined_member)
2152        << 2 << Var->getDeclName() << Var->getDeclContext();
2153      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2154    }
2155
2156    return;
2157  }
2158
2159  // Never instantiate an explicit specialization.
2160  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2161    return;
2162
2163  // C++0x [temp.explicit]p9:
2164  //   Except for inline functions, other explicit instantiation declarations
2165  //   have the effect of suppressing the implicit instantiation of the entity
2166  //   to which they refer.
2167  if (Var->getTemplateSpecializationKind()
2168        == TSK_ExplicitInstantiationDeclaration)
2169    return;
2170
2171  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2172  if (Inst)
2173    return;
2174
2175  // If we're performing recursive template instantiation, create our own
2176  // queue of pending implicit instantiations that we will instantiate later,
2177  // while we're still within our own instantiation context.
2178  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2179  if (Recursive)
2180    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2181
2182  // Enter the scope of this instantiation. We don't use
2183  // PushDeclContext because we don't have a scope.
2184  DeclContext *PreviousContext = CurContext;
2185  CurContext = Var->getDeclContext();
2186
2187  VarDecl *OldVar = Var;
2188  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2189                                          getTemplateInstantiationArgs(Var)));
2190  CurContext = PreviousContext;
2191
2192  if (Var) {
2193    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2194    assert(MSInfo && "Missing member specialization information?");
2195    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2196                                       MSInfo->getPointOfInstantiation());
2197    DeclGroupRef DG(Var);
2198    Consumer.HandleTopLevelDecl(DG);
2199  }
2200
2201  if (Recursive) {
2202    // Instantiate any pending implicit instantiations found during the
2203    // instantiation of this template.
2204    PerformPendingImplicitInstantiations();
2205
2206    // Restore the set of pending implicit instantiations.
2207    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2208  }
2209}
2210
2211void
2212Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2213                                 const CXXConstructorDecl *Tmpl,
2214                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2215
2216  llvm::SmallVector<MemInitTy*, 4> NewInits;
2217  bool AnyErrors = false;
2218
2219  // Instantiate all the initializers.
2220  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2221                                            InitsEnd = Tmpl->init_end();
2222       Inits != InitsEnd; ++Inits) {
2223    CXXBaseOrMemberInitializer *Init = *Inits;
2224
2225    SourceLocation LParenLoc, RParenLoc;
2226    ASTOwningVector<&ActionBase::DeleteExpr> NewArgs(*this);
2227    llvm::SmallVector<SourceLocation, 4> CommaLocs;
2228
2229    // Instantiate the initializer.
2230    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2231                               LParenLoc, CommaLocs, NewArgs, RParenLoc)) {
2232      AnyErrors = true;
2233      continue;
2234    }
2235
2236    MemInitResult NewInit;
2237    if (Init->isBaseInitializer()) {
2238      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2239                                            TemplateArgs,
2240                                            Init->getSourceLocation(),
2241                                            New->getDeclName());
2242      if (!BaseTInfo) {
2243        AnyErrors = true;
2244        New->setInvalidDecl();
2245        continue;
2246      }
2247
2248      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2249                                     (Expr **)NewArgs.data(),
2250                                     NewArgs.size(),
2251                                     Init->getLParenLoc(),
2252                                     Init->getRParenLoc(),
2253                                     New->getParent());
2254    } else if (Init->isMemberInitializer()) {
2255      FieldDecl *Member;
2256
2257      // Is this an anonymous union?
2258      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2259        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2260                                                      UnionInit, TemplateArgs));
2261      else
2262        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2263                                                      Init->getMember(),
2264                                                      TemplateArgs));
2265
2266      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2267                                       NewArgs.size(),
2268                                       Init->getSourceLocation(),
2269                                       Init->getLParenLoc(),
2270                                       Init->getRParenLoc());
2271    }
2272
2273    if (NewInit.isInvalid()) {
2274      AnyErrors = true;
2275      New->setInvalidDecl();
2276    } else {
2277      // FIXME: It would be nice if ASTOwningVector had a release function.
2278      NewArgs.take();
2279
2280      NewInits.push_back((MemInitTy *)NewInit.get());
2281    }
2282  }
2283
2284  // Assign all the initializers to the new constructor.
2285  ActOnMemInitializers(DeclPtrTy::make(New),
2286                       /*FIXME: ColonLoc */
2287                       SourceLocation(),
2288                       NewInits.data(), NewInits.size(),
2289                       AnyErrors);
2290}
2291
2292// TODO: this could be templated if the various decl types used the
2293// same method name.
2294static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2295                              ClassTemplateDecl *Instance) {
2296  Pattern = Pattern->getCanonicalDecl();
2297
2298  do {
2299    Instance = Instance->getCanonicalDecl();
2300    if (Pattern == Instance) return true;
2301    Instance = Instance->getInstantiatedFromMemberTemplate();
2302  } while (Instance);
2303
2304  return false;
2305}
2306
2307static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2308                              FunctionTemplateDecl *Instance) {
2309  Pattern = Pattern->getCanonicalDecl();
2310
2311  do {
2312    Instance = Instance->getCanonicalDecl();
2313    if (Pattern == Instance) return true;
2314    Instance = Instance->getInstantiatedFromMemberTemplate();
2315  } while (Instance);
2316
2317  return false;
2318}
2319
2320static bool
2321isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2322                  ClassTemplatePartialSpecializationDecl *Instance) {
2323  Pattern
2324    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2325  do {
2326    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2327                                                Instance->getCanonicalDecl());
2328    if (Pattern == Instance)
2329      return true;
2330    Instance = Instance->getInstantiatedFromMember();
2331  } while (Instance);
2332
2333  return false;
2334}
2335
2336static bool isInstantiationOf(CXXRecordDecl *Pattern,
2337                              CXXRecordDecl *Instance) {
2338  Pattern = Pattern->getCanonicalDecl();
2339
2340  do {
2341    Instance = Instance->getCanonicalDecl();
2342    if (Pattern == Instance) return true;
2343    Instance = Instance->getInstantiatedFromMemberClass();
2344  } while (Instance);
2345
2346  return false;
2347}
2348
2349static bool isInstantiationOf(FunctionDecl *Pattern,
2350                              FunctionDecl *Instance) {
2351  Pattern = Pattern->getCanonicalDecl();
2352
2353  do {
2354    Instance = Instance->getCanonicalDecl();
2355    if (Pattern == Instance) return true;
2356    Instance = Instance->getInstantiatedFromMemberFunction();
2357  } while (Instance);
2358
2359  return false;
2360}
2361
2362static bool isInstantiationOf(EnumDecl *Pattern,
2363                              EnumDecl *Instance) {
2364  Pattern = Pattern->getCanonicalDecl();
2365
2366  do {
2367    Instance = Instance->getCanonicalDecl();
2368    if (Pattern == Instance) return true;
2369    Instance = Instance->getInstantiatedFromMemberEnum();
2370  } while (Instance);
2371
2372  return false;
2373}
2374
2375static bool isInstantiationOf(UsingShadowDecl *Pattern,
2376                              UsingShadowDecl *Instance,
2377                              ASTContext &C) {
2378  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2379}
2380
2381static bool isInstantiationOf(UsingDecl *Pattern,
2382                              UsingDecl *Instance,
2383                              ASTContext &C) {
2384  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2385}
2386
2387static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2388                              UsingDecl *Instance,
2389                              ASTContext &C) {
2390  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2391}
2392
2393static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2394                              UsingDecl *Instance,
2395                              ASTContext &C) {
2396  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2397}
2398
2399static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2400                                              VarDecl *Instance) {
2401  assert(Instance->isStaticDataMember());
2402
2403  Pattern = Pattern->getCanonicalDecl();
2404
2405  do {
2406    Instance = Instance->getCanonicalDecl();
2407    if (Pattern == Instance) return true;
2408    Instance = Instance->getInstantiatedFromStaticDataMember();
2409  } while (Instance);
2410
2411  return false;
2412}
2413
2414// Other is the prospective instantiation
2415// D is the prospective pattern
2416static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2417  if (D->getKind() != Other->getKind()) {
2418    if (UnresolvedUsingTypenameDecl *UUD
2419          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2420      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2421        return isInstantiationOf(UUD, UD, Ctx);
2422      }
2423    }
2424
2425    if (UnresolvedUsingValueDecl *UUD
2426          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2427      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2428        return isInstantiationOf(UUD, UD, Ctx);
2429      }
2430    }
2431
2432    return false;
2433  }
2434
2435  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2436    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2437
2438  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2439    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2440
2441  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2442    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2443
2444  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2445    if (Var->isStaticDataMember())
2446      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2447
2448  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2449    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2450
2451  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2452    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2453
2454  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2455        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2456    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2457                             PartialSpec);
2458
2459  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2460    if (!Field->getDeclName()) {
2461      // This is an unnamed field.
2462      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2463        cast<FieldDecl>(D);
2464    }
2465  }
2466
2467  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2468    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2469
2470  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2471    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2472
2473  return D->getDeclName() && isa<NamedDecl>(Other) &&
2474    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2475}
2476
2477template<typename ForwardIterator>
2478static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2479                                      NamedDecl *D,
2480                                      ForwardIterator first,
2481                                      ForwardIterator last) {
2482  for (; first != last; ++first)
2483    if (isInstantiationOf(Ctx, D, *first))
2484      return cast<NamedDecl>(*first);
2485
2486  return 0;
2487}
2488
2489/// \brief Finds the instantiation of the given declaration context
2490/// within the current instantiation.
2491///
2492/// \returns NULL if there was an error
2493DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2494                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2495  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2496    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2497    return cast_or_null<DeclContext>(ID);
2498  } else return DC;
2499}
2500
2501/// \brief Find the instantiation of the given declaration within the
2502/// current instantiation.
2503///
2504/// This routine is intended to be used when \p D is a declaration
2505/// referenced from within a template, that needs to mapped into the
2506/// corresponding declaration within an instantiation. For example,
2507/// given:
2508///
2509/// \code
2510/// template<typename T>
2511/// struct X {
2512///   enum Kind {
2513///     KnownValue = sizeof(T)
2514///   };
2515///
2516///   bool getKind() const { return KnownValue; }
2517/// };
2518///
2519/// template struct X<int>;
2520/// \endcode
2521///
2522/// In the instantiation of X<int>::getKind(), we need to map the
2523/// EnumConstantDecl for KnownValue (which refers to
2524/// X<T>::<Kind>::KnownValue) to its instantiation
2525/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2526/// this mapping from within the instantiation of X<int>.
2527NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2528                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2529  DeclContext *ParentDC = D->getDeclContext();
2530  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2531      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2532      ParentDC->isFunctionOrMethod()) {
2533    // D is a local of some kind. Look into the map of local
2534    // declarations to their instantiations.
2535    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2536  }
2537
2538  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2539    if (!Record->isDependentContext())
2540      return D;
2541
2542    // If the RecordDecl is actually the injected-class-name or a
2543    // "templated" declaration for a class template, class template
2544    // partial specialization, or a member class of a class template,
2545    // substitute into the injected-class-name of the class template
2546    // or partial specialization to find the new DeclContext.
2547    QualType T;
2548    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2549
2550    if (ClassTemplate) {
2551      T = ClassTemplate->getInjectedClassNameSpecialization(Context);
2552    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2553                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2554      ClassTemplate = PartialSpec->getSpecializedTemplate();
2555
2556      // If we call SubstType with an InjectedClassNameType here we
2557      // can end up in an infinite loop.
2558      T = Context.getTypeDeclType(Record);
2559      assert(isa<InjectedClassNameType>(T) &&
2560             "type of partial specialization is not an InjectedClassNameType");
2561      T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
2562    }
2563
2564    if (!T.isNull()) {
2565      // Substitute into the injected-class-name to get the type
2566      // corresponding to the instantiation we want, which may also be
2567      // the current instantiation (if we're in a template
2568      // definition). This substitution should never fail, since we
2569      // know we can instantiate the injected-class-name or we
2570      // wouldn't have gotten to the injected-class-name!
2571
2572      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2573      // extra instantiation in the common case?
2574      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2575      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2576
2577      if (!T->isDependentType()) {
2578        assert(T->isRecordType() && "Instantiation must produce a record type");
2579        return T->getAs<RecordType>()->getDecl();
2580      }
2581
2582      // We are performing "partial" template instantiation to create
2583      // the member declarations for the members of a class template
2584      // specialization. Therefore, D is actually referring to something
2585      // in the current instantiation. Look through the current
2586      // context, which contains actual instantiations, to find the
2587      // instantiation of the "current instantiation" that D refers
2588      // to.
2589      bool SawNonDependentContext = false;
2590      for (DeclContext *DC = CurContext; !DC->isFileContext();
2591           DC = DC->getParent()) {
2592        if (ClassTemplateSpecializationDecl *Spec
2593                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2594          if (isInstantiationOf(ClassTemplate,
2595                                Spec->getSpecializedTemplate()))
2596            return Spec;
2597
2598        if (!DC->isDependentContext())
2599          SawNonDependentContext = true;
2600      }
2601
2602      // We're performing "instantiation" of a member of the current
2603      // instantiation while we are type-checking the
2604      // definition. Compute the declaration context and return that.
2605      assert(!SawNonDependentContext &&
2606             "No dependent context while instantiating record");
2607      DeclContext *DC = computeDeclContext(T);
2608      assert(DC &&
2609             "Unable to find declaration for the current instantiation");
2610      return cast<CXXRecordDecl>(DC);
2611    }
2612
2613    // Fall through to deal with other dependent record types (e.g.,
2614    // anonymous unions in class templates).
2615  }
2616
2617  if (!ParentDC->isDependentContext())
2618    return D;
2619
2620  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2621  if (!ParentDC)
2622    return 0;
2623
2624  if (ParentDC != D->getDeclContext()) {
2625    // We performed some kind of instantiation in the parent context,
2626    // so now we need to look into the instantiated parent context to
2627    // find the instantiation of the declaration D.
2628
2629    // If our context used to be dependent, we may need to instantiate
2630    // it before performing lookup into that context.
2631    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2632      if (!Spec->isDependentContext()) {
2633        QualType T = Context.getTypeDeclType(Spec);
2634        const RecordType *Tag = T->getAs<RecordType>();
2635        assert(Tag && "type of non-dependent record is not a RecordType");
2636        if (!Tag->isBeingDefined() &&
2637            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2638          return 0;
2639      }
2640    }
2641
2642    NamedDecl *Result = 0;
2643    if (D->getDeclName()) {
2644      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2645      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2646    } else {
2647      // Since we don't have a name for the entity we're looking for,
2648      // our only option is to walk through all of the declarations to
2649      // find that name. This will occur in a few cases:
2650      //
2651      //   - anonymous struct/union within a template
2652      //   - unnamed class/struct/union/enum within a template
2653      //
2654      // FIXME: Find a better way to find these instantiations!
2655      Result = findInstantiationOf(Context, D,
2656                                   ParentDC->decls_begin(),
2657                                   ParentDC->decls_end());
2658    }
2659
2660    // UsingShadowDecls can instantiate to nothing because of using hiding.
2661    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2662            cast<Decl>(ParentDC)->isInvalidDecl())
2663           && "Unable to find instantiation of declaration!");
2664
2665    D = Result;
2666  }
2667
2668  return D;
2669}
2670
2671/// \brief Performs template instantiation for all implicit template
2672/// instantiations we have seen until this point.
2673void Sema::PerformPendingImplicitInstantiations(bool LocalOnly) {
2674  while (!PendingLocalImplicitInstantiations.empty() ||
2675         (!LocalOnly && !PendingImplicitInstantiations.empty())) {
2676    PendingImplicitInstantiation Inst;
2677
2678    if (PendingLocalImplicitInstantiations.empty()) {
2679      Inst = PendingImplicitInstantiations.front();
2680      PendingImplicitInstantiations.pop_front();
2681    } else {
2682      Inst = PendingLocalImplicitInstantiations.front();
2683      PendingLocalImplicitInstantiations.pop_front();
2684    }
2685
2686    // Instantiate function definitions
2687    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2688      PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Function),
2689                                            Function->getLocation(), *this,
2690                                            Context.getSourceManager(),
2691                                           "instantiating function definition");
2692
2693      InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true);
2694      continue;
2695    }
2696
2697    // Instantiate static data member definitions.
2698    VarDecl *Var = cast<VarDecl>(Inst.first);
2699    assert(Var->isStaticDataMember() && "Not a static data member?");
2700
2701    // Don't try to instantiate declarations if the most recent redeclaration
2702    // is invalid.
2703    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2704      continue;
2705
2706    // Check if the most recent declaration has changed the specialization kind
2707    // and removed the need for implicit instantiation.
2708    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2709    case TSK_Undeclared:
2710      assert(false && "Cannot instantitiate an undeclared specialization.");
2711    case TSK_ExplicitInstantiationDeclaration:
2712    case TSK_ExplicitInstantiationDefinition:
2713    case TSK_ExplicitSpecialization:
2714      continue;  // No longer need implicit instantiation.
2715    case TSK_ImplicitInstantiation:
2716      break;
2717    }
2718
2719    PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Var),
2720                                          Var->getLocation(), *this,
2721                                          Context.getSourceManager(),
2722                                          "instantiating static data member "
2723                                          "definition");
2724
2725    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true);
2726  }
2727}
2728
2729void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2730                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2731  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2732         E = Pattern->ddiag_end(); I != E; ++I) {
2733    DependentDiagnostic *DD = *I;
2734
2735    switch (DD->getKind()) {
2736    case DependentDiagnostic::Access:
2737      HandleDependentAccessCheck(*DD, TemplateArgs);
2738      break;
2739    }
2740  }
2741}
2742