SemaTemplateInstantiateDecl.cpp revision ea7b4880bc07cd99b3994c2a95d722a06ab56594 
1//===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//===----------------------------------------------------------------------===/
8//
9//  This file implements C++ template instantiation for declarations.
10//
11//===----------------------------------------------------------------------===/
12#include "Sema.h"
13#include "Lookup.h"
14#include "clang/AST/ASTConsumer.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/DeclTemplate.h"
17#include "clang/AST/DeclVisitor.h"
18#include "clang/AST/DependentDiagnostic.h"
19#include "clang/AST/Expr.h"
20#include "clang/AST/ExprCXX.h"
21#include "clang/AST/TypeLoc.h"
22#include "clang/Basic/PrettyStackTrace.h"
23#include "clang/Lex/Preprocessor.h"
24
25using namespace clang;
26
27namespace {
28  class TemplateDeclInstantiator
29    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
30    Sema &SemaRef;
31    DeclContext *Owner;
32    const MultiLevelTemplateArgumentList &TemplateArgs;
33
34    void InstantiateAttrs(Decl *Tmpl, Decl *New);
35
36  public:
37    typedef Sema::OwningExprResult OwningExprResult;
38
39    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
40                             const MultiLevelTemplateArgumentList &TemplateArgs)
41      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
42
43    // FIXME: Once we get closer to completion, replace these manually-written
44    // declarations with automatically-generated ones from
45    // clang/AST/DeclNodes.inc.
46    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
47    Decl *VisitNamespaceDecl(NamespaceDecl *D);
48    Decl *VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
49    Decl *VisitTypedefDecl(TypedefDecl *D);
50    Decl *VisitVarDecl(VarDecl *D);
51    Decl *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->getType()->isVariablyModifiedType()) {
189    DI = SemaRef.SubstType(DI, TemplateArgs,
190                           D->getLocation(), D->getDeclName());
191    if (!DI) {
192      Invalid = true;
193      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
194    }
195  } else {
196    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
197  }
198
199  // Create the new typedef
200  TypedefDecl *Typedef
201    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
202                          D->getIdentifier(), DI);
203  if (Invalid)
204    Typedef->setInvalidDecl();
205
206  if (const TagType *TT = DI->getType()->getAs<TagType>()) {
207    TagDecl *TD = TT->getDecl();
208
209    // If the TagDecl that the TypedefDecl points to is an anonymous decl
210    // keep track of the TypedefDecl.
211    if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl())
212      TD->setTypedefForAnonDecl(Typedef);
213  }
214
215  if (TypedefDecl *Prev = D->getPreviousDeclaration()) {
216    NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
217                                                       TemplateArgs);
218    Typedef->setPreviousDeclaration(cast<TypedefDecl>(InstPrev));
219  }
220
221  InstantiateAttrs(D, Typedef);
222
223  Typedef->setAccess(D->getAccess());
224  Owner->addDecl(Typedef);
225
226  return Typedef;
227}
228
229/// \brief Instantiate the arguments provided as part of initialization.
230///
231/// \returns true if an error occurred, false otherwise.
232static bool InstantiateInitializationArguments(Sema &SemaRef,
233                                               Expr **Args, unsigned NumArgs,
234                           const MultiLevelTemplateArgumentList &TemplateArgs,
235                         llvm::SmallVectorImpl<SourceLocation> &FakeCommaLocs,
236                           ASTOwningVector<&ActionBase::DeleteExpr> &InitArgs) {
237  for (unsigned I = 0; I != NumArgs; ++I) {
238    // When we hit the first defaulted argument, break out of the loop:
239    // we don't pass those default arguments on.
240    if (Args[I]->isDefaultArgument())
241      break;
242
243    Sema::OwningExprResult Arg = SemaRef.SubstExpr(Args[I], TemplateArgs);
244    if (Arg.isInvalid())
245      return true;
246
247    Expr *ArgExpr = (Expr *)Arg.get();
248    InitArgs.push_back(Arg.release());
249
250    // FIXME: We're faking all of the comma locations. Do we need them?
251    FakeCommaLocs.push_back(
252                          SemaRef.PP.getLocForEndOfToken(ArgExpr->getLocEnd()));
253  }
254
255  return false;
256}
257
258/// \brief Instantiate an initializer, breaking it into separate
259/// initialization arguments.
260///
261/// \param S The semantic analysis object.
262///
263/// \param Init The initializer to instantiate.
264///
265/// \param TemplateArgs Template arguments to be substituted into the
266/// initializer.
267///
268/// \param NewArgs Will be filled in with the instantiation arguments.
269///
270/// \returns true if an error occurred, false otherwise
271static bool InstantiateInitializer(Sema &S, Expr *Init,
272                            const MultiLevelTemplateArgumentList &TemplateArgs,
273                                   SourceLocation &LParenLoc,
274                               llvm::SmallVector<SourceLocation, 4> &CommaLocs,
275                             ASTOwningVector<&ActionBase::DeleteExpr> &NewArgs,
276                                   SourceLocation &RParenLoc) {
277  NewArgs.clear();
278  LParenLoc = SourceLocation();
279  RParenLoc = SourceLocation();
280
281  if (!Init)
282    return false;
283
284  if (CXXExprWithTemporaries *ExprTemp = dyn_cast<CXXExprWithTemporaries>(Init))
285    Init = ExprTemp->getSubExpr();
286
287  while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init))
288    Init = Binder->getSubExpr();
289
290  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
291    Init = ICE->getSubExprAsWritten();
292
293  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
294    LParenLoc = ParenList->getLParenLoc();
295    RParenLoc = ParenList->getRParenLoc();
296    return InstantiateInitializationArguments(S, ParenList->getExprs(),
297                                              ParenList->getNumExprs(),
298                                              TemplateArgs, CommaLocs,
299                                              NewArgs);
300  }
301
302  if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) {
303    if (!isa<CXXTemporaryObjectExpr>(Construct)) {
304      if (InstantiateInitializationArguments(S,
305                                             Construct->getArgs(),
306                                             Construct->getNumArgs(),
307                                             TemplateArgs,
308                                             CommaLocs, NewArgs))
309        return true;
310
311      // FIXME: Fake locations!
312      LParenLoc = S.PP.getLocForEndOfToken(Init->getLocStart());
313      RParenLoc = CommaLocs.empty()? LParenLoc : CommaLocs.back();
314      return false;
315    }
316  }
317
318  Sema::OwningExprResult Result = S.SubstExpr(Init, TemplateArgs);
319  if (Result.isInvalid())
320    return true;
321
322  NewArgs.push_back(Result.takeAs<Expr>());
323  return false;
324}
325
326Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
327  // If this is the variable for an anonymous struct or union,
328  // instantiate the anonymous struct/union type first.
329  if (const RecordType *RecordTy = D->getType()->getAs<RecordType>())
330    if (RecordTy->getDecl()->isAnonymousStructOrUnion())
331      if (!VisitCXXRecordDecl(cast<CXXRecordDecl>(RecordTy->getDecl())))
332        return 0;
333
334  // Do substitution on the type of the declaration
335  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
336                                         TemplateArgs,
337                                         D->getTypeSpecStartLoc(),
338                                         D->getDeclName());
339  if (!DI)
340    return 0;
341
342  // Build the instantiated declaration
343  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
344                                 D->getLocation(), D->getIdentifier(),
345                                 DI->getType(), DI,
346                                 D->getStorageClass(),
347                                 D->getStorageClassAsWritten());
348  Var->setThreadSpecified(D->isThreadSpecified());
349  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
350  Var->setDeclaredInCondition(D->isDeclaredInCondition());
351
352  // Substitute the nested name specifier, if any.
353  if (SubstQualifier(D, Var))
354    return 0;
355
356  // If we are instantiating a static data member defined
357  // out-of-line, the instantiation will have the same lexical
358  // context (which will be a namespace scope) as the template.
359  if (D->isOutOfLine())
360    Var->setLexicalDeclContext(D->getLexicalDeclContext());
361
362  Var->setAccess(D->getAccess());
363  Var->setUsed(D->isUsed());
364
365  // FIXME: In theory, we could have a previous declaration for variables that
366  // are not static data members.
367  bool Redeclaration = false;
368  // FIXME: having to fake up a LookupResult is dumb.
369  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
370                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
371  if (D->isStaticDataMember())
372    SemaRef.LookupQualifiedName(Previous, Owner, false);
373  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
374
375  if (D->isOutOfLine()) {
376    if (!D->isStaticDataMember())
377      D->getLexicalDeclContext()->addDecl(Var);
378    Owner->makeDeclVisibleInContext(Var);
379  } else {
380    Owner->addDecl(Var);
381
382    if (Owner->isFunctionOrMethod())
383      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Var);
384  }
385
386  // Link instantiations of static data members back to the template from
387  // which they were instantiated.
388  if (Var->isStaticDataMember())
389    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
390                                                     TSK_ImplicitInstantiation);
391
392  if (Var->getAnyInitializer()) {
393    // We already have an initializer in the class.
394  } else if (D->getInit()) {
395    if (Var->isStaticDataMember() && !D->isOutOfLine())
396      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
397    else
398      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
399
400    // Instantiate the initializer.
401    SourceLocation LParenLoc, RParenLoc;
402    llvm::SmallVector<SourceLocation, 4> CommaLocs;
403    ASTOwningVector<&ActionBase::DeleteExpr> InitArgs(SemaRef);
404    if (!InstantiateInitializer(SemaRef, D->getInit(), TemplateArgs, LParenLoc,
405                                CommaLocs, InitArgs, RParenLoc)) {
406      // Attach the initializer to the declaration.
407      if (D->hasCXXDirectInitializer()) {
408        // Add the direct initializer to the declaration.
409        SemaRef.AddCXXDirectInitializerToDecl(Sema::DeclPtrTy::make(Var),
410                                              LParenLoc,
411                                              move_arg(InitArgs),
412                                              CommaLocs.data(),
413                                              RParenLoc);
414      } else if (InitArgs.size() == 1) {
415        Expr *Init = (Expr*)(InitArgs.take()[0]);
416        SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var),
417                                     SemaRef.Owned(Init),
418                                     false);
419      } else {
420        assert(InitArgs.size() == 0);
421        SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
422      }
423    } else {
424      // FIXME: Not too happy about invalidating the declaration
425      // because of a bogus initializer.
426      Var->setInvalidDecl();
427    }
428
429    SemaRef.PopExpressionEvaluationContext();
430  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
431    SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
432
433  // Diagnose unused local variables.
434  if (!Var->isInvalidDecl() && Owner->isFunctionOrMethod() && !Var->isUsed())
435    SemaRef.DiagnoseUnusedDecl(Var);
436
437  return Var;
438}
439
440Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
441  bool Invalid = false;
442  TypeSourceInfo *DI = D->getTypeSourceInfo();
443  if (DI->getType()->isDependentType() ||
444      DI->getType()->isVariablyModifiedType())  {
445    DI = SemaRef.SubstType(DI, TemplateArgs,
446                           D->getLocation(), D->getDeclName());
447    if (!DI) {
448      DI = D->getTypeSourceInfo();
449      Invalid = true;
450    } else if (DI->getType()->isFunctionType()) {
451      // C++ [temp.arg.type]p3:
452      //   If a declaration acquires a function type through a type
453      //   dependent on a template-parameter and this causes a
454      //   declaration that does not use the syntactic form of a
455      //   function declarator to have function type, the program is
456      //   ill-formed.
457      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
458        << DI->getType();
459      Invalid = true;
460    }
461  } else {
462    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
463  }
464
465  Expr *BitWidth = D->getBitWidth();
466  if (Invalid)
467    BitWidth = 0;
468  else if (BitWidth) {
469    // The bit-width expression is not potentially evaluated.
470    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
471
472    OwningExprResult InstantiatedBitWidth
473      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
474    if (InstantiatedBitWidth.isInvalid()) {
475      Invalid = true;
476      BitWidth = 0;
477    } else
478      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
479  }
480
481  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
482                                            DI->getType(), DI,
483                                            cast<RecordDecl>(Owner),
484                                            D->getLocation(),
485                                            D->isMutable(),
486                                            BitWidth,
487                                            D->getTypeSpecStartLoc(),
488                                            D->getAccess(),
489                                            0);
490  if (!Field) {
491    cast<Decl>(Owner)->setInvalidDecl();
492    return 0;
493  }
494
495  InstantiateAttrs(D, Field);
496
497  if (Invalid)
498    Field->setInvalidDecl();
499
500  if (!Field->getDeclName()) {
501    // Keep track of where this decl came from.
502    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
503  }
504  if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
505    if (Parent->isAnonymousStructOrUnion() &&
506        Parent->getLookupContext()->isFunctionOrMethod())
507      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
508  }
509
510  Field->setImplicit(D->isImplicit());
511  Field->setAccess(D->getAccess());
512  Owner->addDecl(Field);
513
514  return Field;
515}
516
517Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
518  // Handle friend type expressions by simply substituting template
519  // parameters into the pattern type and checking the result.
520  if (TypeSourceInfo *Ty = D->getFriendType()) {
521    TypeSourceInfo *InstTy =
522      SemaRef.SubstType(Ty, TemplateArgs,
523                        D->getLocation(), DeclarationName());
524    if (!InstTy)
525      return 0;
526
527    FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getFriendLoc(), InstTy);
528    if (!FD)
529      return 0;
530
531    FD->setAccess(AS_public);
532    Owner->addDecl(FD);
533    return FD;
534  }
535
536  NamedDecl *ND = D->getFriendDecl();
537  assert(ND && "friend decl must be a decl or a type!");
538
539  // All of the Visit implementations for the various potential friend
540  // declarations have to be carefully written to work for friend
541  // objects, with the most important detail being that the target
542  // decl should almost certainly not be placed in Owner.
543  Decl *NewND = Visit(ND);
544  if (!NewND) return 0;
545
546  FriendDecl *FD =
547    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
548                       cast<NamedDecl>(NewND), D->getFriendLoc());
549  FD->setAccess(AS_public);
550  Owner->addDecl(FD);
551  return FD;
552}
553
554Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
555  Expr *AssertExpr = D->getAssertExpr();
556
557  // The expression in a static assertion is not potentially evaluated.
558  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
559
560  OwningExprResult InstantiatedAssertExpr
561    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
562  if (InstantiatedAssertExpr.isInvalid())
563    return 0;
564
565  OwningExprResult Message(SemaRef, D->getMessage());
566  D->getMessage()->Retain();
567  Decl *StaticAssert
568    = SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
569                                           move(InstantiatedAssertExpr),
570                                           move(Message)).getAs<Decl>();
571  return StaticAssert;
572}
573
574Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
575  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
576                                    D->getLocation(), D->getIdentifier(),
577                                    D->getTagKeywordLoc(),
578                                    /*PrevDecl=*/0);
579  Enum->setInstantiationOfMemberEnum(D);
580  Enum->setAccess(D->getAccess());
581  if (SubstQualifier(D, Enum)) return 0;
582  Owner->addDecl(Enum);
583  Enum->startDefinition();
584
585  if (D->getDeclContext()->isFunctionOrMethod())
586    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
587
588  llvm::SmallVector<Sema::DeclPtrTy, 4> Enumerators;
589
590  EnumConstantDecl *LastEnumConst = 0;
591  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
592         ECEnd = D->enumerator_end();
593       EC != ECEnd; ++EC) {
594    // The specified value for the enumerator.
595    OwningExprResult Value = SemaRef.Owned((Expr *)0);
596    if (Expr *UninstValue = EC->getInitExpr()) {
597      // The enumerator's value expression is not potentially evaluated.
598      EnterExpressionEvaluationContext Unevaluated(SemaRef,
599                                                   Action::Unevaluated);
600
601      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
602    }
603
604    // Drop the initial value and continue.
605    bool isInvalid = false;
606    if (Value.isInvalid()) {
607      Value = SemaRef.Owned((Expr *)0);
608      isInvalid = true;
609    }
610
611    EnumConstantDecl *EnumConst
612      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
613                                  EC->getLocation(), EC->getIdentifier(),
614                                  move(Value));
615
616    if (isInvalid) {
617      if (EnumConst)
618        EnumConst->setInvalidDecl();
619      Enum->setInvalidDecl();
620    }
621
622    if (EnumConst) {
623      EnumConst->setAccess(Enum->getAccess());
624      Enum->addDecl(EnumConst);
625      Enumerators.push_back(Sema::DeclPtrTy::make(EnumConst));
626      LastEnumConst = EnumConst;
627
628      if (D->getDeclContext()->isFunctionOrMethod()) {
629        // If the enumeration is within a function or method, record the enum
630        // constant as a local.
631        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
632      }
633    }
634  }
635
636  // FIXME: Fixup LBraceLoc and RBraceLoc
637  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
638  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
639                        Sema::DeclPtrTy::make(Enum),
640                        &Enumerators[0], Enumerators.size(),
641                        0, 0);
642
643  return Enum;
644}
645
646Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
647  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
648  return 0;
649}
650
651Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
652  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
653
654  // Create a local instantiation scope for this class template, which
655  // will contain the instantiations of the template parameters.
656  Sema::LocalInstantiationScope Scope(SemaRef);
657  TemplateParameterList *TempParams = D->getTemplateParameters();
658  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
659  if (!InstParams)
660    return NULL;
661
662  CXXRecordDecl *Pattern = D->getTemplatedDecl();
663
664  // Instantiate the qualifier.  We have to do this first in case
665  // we're a friend declaration, because if we are then we need to put
666  // the new declaration in the appropriate context.
667  NestedNameSpecifier *Qualifier = Pattern->getQualifier();
668  if (Qualifier) {
669    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
670                                                 Pattern->getQualifierRange(),
671                                                 TemplateArgs);
672    if (!Qualifier) return 0;
673  }
674
675  CXXRecordDecl *PrevDecl = 0;
676  ClassTemplateDecl *PrevClassTemplate = 0;
677
678  // If this isn't a friend, then it's a member template, in which
679  // case we just want to build the instantiation in the
680  // specialization.  If it is a friend, we want to build it in
681  // the appropriate context.
682  DeclContext *DC = Owner;
683  if (isFriend) {
684    if (Qualifier) {
685      CXXScopeSpec SS;
686      SS.setScopeRep(Qualifier);
687      SS.setRange(Pattern->getQualifierRange());
688      DC = SemaRef.computeDeclContext(SS);
689      if (!DC) return 0;
690    } else {
691      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
692                                           Pattern->getDeclContext(),
693                                           TemplateArgs);
694    }
695
696    // Look for a previous declaration of the template in the owning
697    // context.
698    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
699                   Sema::LookupOrdinaryName, Sema::ForRedeclaration);
700    SemaRef.LookupQualifiedName(R, DC);
701
702    if (R.isSingleResult()) {
703      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
704      if (PrevClassTemplate)
705        PrevDecl = PrevClassTemplate->getTemplatedDecl();
706    }
707
708    if (!PrevClassTemplate && Qualifier) {
709      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
710        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
711        << Pattern->getQualifierRange();
712      return 0;
713    }
714
715    bool AdoptedPreviousTemplateParams = false;
716    if (PrevClassTemplate) {
717      bool Complain = true;
718
719      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
720      // template for struct std::tr1::__detail::_Map_base, where the
721      // template parameters of the friend declaration don't match the
722      // template parameters of the original declaration. In this one
723      // case, we don't complain about the ill-formed friend
724      // declaration.
725      if (isFriend && Pattern->getIdentifier() &&
726          Pattern->getIdentifier()->isStr("_Map_base") &&
727          DC->isNamespace() &&
728          cast<NamespaceDecl>(DC)->getIdentifier() &&
729          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
730        DeclContext *DCParent = DC->getParent();
731        if (DCParent->isNamespace() &&
732            cast<NamespaceDecl>(DCParent)->getIdentifier() &&
733            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
734          DeclContext *DCParent2 = DCParent->getParent();
735          if (DCParent2->isNamespace() &&
736              cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
737              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
738              DCParent2->getParent()->isTranslationUnit())
739            Complain = false;
740        }
741      }
742
743      TemplateParameterList *PrevParams
744        = PrevClassTemplate->getTemplateParameters();
745
746      // Make sure the parameter lists match.
747      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
748                                                  Complain,
749                                                  Sema::TPL_TemplateMatch)) {
750        if (Complain)
751          return 0;
752
753        AdoptedPreviousTemplateParams = true;
754        InstParams = PrevParams;
755      }
756
757      // Do some additional validation, then merge default arguments
758      // from the existing declarations.
759      if (!AdoptedPreviousTemplateParams &&
760          SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
761                                             Sema::TPC_ClassTemplate))
762        return 0;
763    }
764  }
765
766  CXXRecordDecl *RecordInst
767    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
768                            Pattern->getLocation(), Pattern->getIdentifier(),
769                            Pattern->getTagKeywordLoc(), PrevDecl,
770                            /*DelayTypeCreation=*/true);
771
772  if (Qualifier)
773    RecordInst->setQualifierInfo(Qualifier, Pattern->getQualifierRange());
774
775  ClassTemplateDecl *Inst
776    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
777                                D->getIdentifier(), InstParams, RecordInst,
778                                PrevClassTemplate);
779  RecordInst->setDescribedClassTemplate(Inst);
780
781  if (isFriend) {
782    if (PrevClassTemplate)
783      Inst->setAccess(PrevClassTemplate->getAccess());
784    else
785      Inst->setAccess(D->getAccess());
786
787    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
788    // TODO: do we want to track the instantiation progeny of this
789    // friend target decl?
790  } else {
791    Inst->setAccess(D->getAccess());
792    Inst->setInstantiatedFromMemberTemplate(D);
793  }
794
795  // Trigger creation of the type for the instantiation.
796  SemaRef.Context.getInjectedClassNameType(RecordInst,
797                  Inst->getInjectedClassNameSpecialization(SemaRef.Context));
798
799  // Finish handling of friends.
800  if (isFriend) {
801    DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
802    return Inst;
803  }
804
805  Owner->addDecl(Inst);
806
807  // Instantiate all of the partial specializations of this member class
808  // template.
809  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
810  D->getPartialSpecializations(PartialSpecs);
811  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
812    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
813
814  return Inst;
815}
816
817Decl *
818TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
819                                   ClassTemplatePartialSpecializationDecl *D) {
820  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
821
822  // Lookup the already-instantiated declaration in the instantiation
823  // of the class template and return that.
824  DeclContext::lookup_result Found
825    = Owner->lookup(ClassTemplate->getDeclName());
826  if (Found.first == Found.second)
827    return 0;
828
829  ClassTemplateDecl *InstClassTemplate
830    = dyn_cast<ClassTemplateDecl>(*Found.first);
831  if (!InstClassTemplate)
832    return 0;
833
834  Decl *DCanon = D->getCanonicalDecl();
835  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
836            P = InstClassTemplate->getPartialSpecializations().begin(),
837         PEnd = InstClassTemplate->getPartialSpecializations().end();
838       P != PEnd; ++P) {
839    if (P->getInstantiatedFromMember()->getCanonicalDecl() == DCanon)
840      return &*P;
841  }
842
843  return 0;
844}
845
846Decl *
847TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
848  // Create a local instantiation scope for this function template, which
849  // will contain the instantiations of the template parameters and then get
850  // merged with the local instantiation scope for the function template
851  // itself.
852  Sema::LocalInstantiationScope Scope(SemaRef);
853
854  TemplateParameterList *TempParams = D->getTemplateParameters();
855  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
856  if (!InstParams)
857    return NULL;
858
859  FunctionDecl *Instantiated = 0;
860  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
861    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
862                                                                 InstParams));
863  else
864    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
865                                                          D->getTemplatedDecl(),
866                                                                InstParams));
867
868  if (!Instantiated)
869    return 0;
870
871  Instantiated->setAccess(D->getAccess());
872
873  // Link the instantiated function template declaration to the function
874  // template from which it was instantiated.
875  FunctionTemplateDecl *InstTemplate
876    = Instantiated->getDescribedFunctionTemplate();
877  InstTemplate->setAccess(D->getAccess());
878  assert(InstTemplate &&
879         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
880
881  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
882
883  // Link the instantiation back to the pattern *unless* this is a
884  // non-definition friend declaration.
885  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
886      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
887    InstTemplate->setInstantiatedFromMemberTemplate(D);
888
889  // Make declarations visible in the appropriate context.
890  if (!isFriend)
891    Owner->addDecl(InstTemplate);
892
893  return InstTemplate;
894}
895
896Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
897  CXXRecordDecl *PrevDecl = 0;
898  if (D->isInjectedClassName())
899    PrevDecl = cast<CXXRecordDecl>(Owner);
900  else if (D->getPreviousDeclaration()) {
901    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
902                                                   D->getPreviousDeclaration(),
903                                                   TemplateArgs);
904    if (!Prev) return 0;
905    PrevDecl = cast<CXXRecordDecl>(Prev);
906  }
907
908  CXXRecordDecl *Record
909    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
910                            D->getLocation(), D->getIdentifier(),
911                            D->getTagKeywordLoc(), PrevDecl);
912
913  // Substitute the nested name specifier, if any.
914  if (SubstQualifier(D, Record))
915    return 0;
916
917  Record->setImplicit(D->isImplicit());
918  // FIXME: Check against AS_none is an ugly hack to work around the issue that
919  // the tag decls introduced by friend class declarations don't have an access
920  // specifier. Remove once this area of the code gets sorted out.
921  if (D->getAccess() != AS_none)
922    Record->setAccess(D->getAccess());
923  if (!D->isInjectedClassName())
924    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
925
926  // If the original function was part of a friend declaration,
927  // inherit its namespace state.
928  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
929    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
930
931  // Make sure that anonymous structs and unions are recorded.
932  if (D->isAnonymousStructOrUnion()) {
933    Record->setAnonymousStructOrUnion(true);
934    if (Record->getDeclContext()->getLookupContext()->isFunctionOrMethod())
935      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
936  }
937
938  Owner->addDecl(Record);
939  return Record;
940}
941
942/// Normal class members are of more specific types and therefore
943/// don't make it here.  This function serves two purposes:
944///   1) instantiating function templates
945///   2) substituting friend declarations
946/// FIXME: preserve function definitions in case #2
947Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
948                                       TemplateParameterList *TemplateParams) {
949  // Check whether there is already a function template specialization for
950  // this declaration.
951  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
952  void *InsertPos = 0;
953  if (FunctionTemplate && !TemplateParams) {
954    llvm::FoldingSetNodeID ID;
955    FunctionTemplateSpecializationInfo::Profile(ID,
956                             TemplateArgs.getInnermost().getFlatArgumentList(),
957                                       TemplateArgs.getInnermost().flat_size(),
958                                                SemaRef.Context);
959
960    FunctionTemplateSpecializationInfo *Info
961      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
962                                                                   InsertPos);
963
964    // If we already have a function template specialization, return it.
965    if (Info)
966      return Info->Function;
967  }
968
969  bool isFriend;
970  if (FunctionTemplate)
971    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
972  else
973    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
974
975  bool MergeWithParentScope = (TemplateParams != 0) ||
976    Owner->isFunctionOrMethod() ||
977    !(isa<Decl>(Owner) &&
978      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
979  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
980
981  llvm::SmallVector<ParmVarDecl *, 4> Params;
982  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
983  TInfo = SubstFunctionType(D, Params);
984  if (!TInfo)
985    return 0;
986  QualType T = TInfo->getType();
987
988  NestedNameSpecifier *Qualifier = D->getQualifier();
989  if (Qualifier) {
990    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
991                                                 D->getQualifierRange(),
992                                                 TemplateArgs);
993    if (!Qualifier) return 0;
994  }
995
996  // If we're instantiating a local function declaration, put the result
997  // in the owner;  otherwise we need to find the instantiated context.
998  DeclContext *DC;
999  if (D->getDeclContext()->isFunctionOrMethod())
1000    DC = Owner;
1001  else if (isFriend && Qualifier) {
1002    CXXScopeSpec SS;
1003    SS.setScopeRep(Qualifier);
1004    SS.setRange(D->getQualifierRange());
1005    DC = SemaRef.computeDeclContext(SS);
1006    if (!DC) return 0;
1007  } else {
1008    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1009                                         TemplateArgs);
1010  }
1011
1012  FunctionDecl *Function =
1013      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
1014                           D->getDeclName(), T, TInfo,
1015                           D->getStorageClass(), D->getStorageClassAsWritten(),
1016                           D->isInlineSpecified(), D->hasWrittenPrototype());
1017
1018  if (Qualifier)
1019    Function->setQualifierInfo(Qualifier, D->getQualifierRange());
1020
1021  DeclContext *LexicalDC = Owner;
1022  if (!isFriend && D->isOutOfLine()) {
1023    assert(D->getDeclContext()->isFileContext());
1024    LexicalDC = D->getDeclContext();
1025  }
1026
1027  Function->setLexicalDeclContext(LexicalDC);
1028
1029  // Attach the parameters
1030  for (unsigned P = 0; P < Params.size(); ++P)
1031    Params[P]->setOwningFunction(Function);
1032  Function->setParams(Params.data(), Params.size());
1033
1034  SourceLocation InstantiateAtPOI;
1035  if (TemplateParams) {
1036    // Our resulting instantiation is actually a function template, since we
1037    // are substituting only the outer template parameters. For example, given
1038    //
1039    //   template<typename T>
1040    //   struct X {
1041    //     template<typename U> friend void f(T, U);
1042    //   };
1043    //
1044    //   X<int> x;
1045    //
1046    // We are instantiating the friend function template "f" within X<int>,
1047    // which means substituting int for T, but leaving "f" as a friend function
1048    // template.
1049    // Build the function template itself.
1050    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1051                                                    Function->getLocation(),
1052                                                    Function->getDeclName(),
1053                                                    TemplateParams, Function);
1054    Function->setDescribedFunctionTemplate(FunctionTemplate);
1055
1056    FunctionTemplate->setLexicalDeclContext(LexicalDC);
1057
1058    if (isFriend && D->isThisDeclarationADefinition()) {
1059      // TODO: should we remember this connection regardless of whether
1060      // the friend declaration provided a body?
1061      FunctionTemplate->setInstantiatedFromMemberTemplate(
1062                                           D->getDescribedFunctionTemplate());
1063    }
1064  } else if (FunctionTemplate) {
1065    // Record this function template specialization.
1066    Function->setFunctionTemplateSpecialization(FunctionTemplate,
1067                                                &TemplateArgs.getInnermost(),
1068                                                InsertPos);
1069  } else if (isFriend && D->isThisDeclarationADefinition()) {
1070    // TODO: should we remember this connection regardless of whether
1071    // the friend declaration provided a body?
1072    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1073  }
1074
1075  if (InitFunctionInstantiation(Function, D))
1076    Function->setInvalidDecl();
1077
1078  bool Redeclaration = false;
1079  bool OverloadableAttrRequired = false;
1080  bool isExplicitSpecialization = false;
1081
1082  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1083                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1084
1085  if (DependentFunctionTemplateSpecializationInfo *Info
1086        = D->getDependentSpecializationInfo()) {
1087    assert(isFriend && "non-friend has dependent specialization info?");
1088
1089    // This needs to be set now for future sanity.
1090    Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1091
1092    // Instantiate the explicit template arguments.
1093    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1094                                          Info->getRAngleLoc());
1095    for (unsigned I = 0, E = Info->getNumTemplateArgs(); I != E; ++I) {
1096      TemplateArgumentLoc Loc;
1097      if (SemaRef.Subst(Info->getTemplateArg(I), Loc, TemplateArgs))
1098        return 0;
1099
1100      ExplicitArgs.addArgument(Loc);
1101    }
1102
1103    // Map the candidate templates to their instantiations.
1104    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1105      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1106                                                Info->getTemplate(I),
1107                                                TemplateArgs);
1108      if (!Temp) return 0;
1109
1110      Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1111    }
1112
1113    if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1114                                                    &ExplicitArgs,
1115                                                    Previous))
1116      Function->setInvalidDecl();
1117
1118    isExplicitSpecialization = true;
1119
1120  } else if (TemplateParams || !FunctionTemplate) {
1121    // Look only into the namespace where the friend would be declared to
1122    // find a previous declaration. This is the innermost enclosing namespace,
1123    // as described in ActOnFriendFunctionDecl.
1124    SemaRef.LookupQualifiedName(Previous, DC);
1125
1126    // In C++, the previous declaration we find might be a tag type
1127    // (class or enum). In this case, the new declaration will hide the
1128    // tag type. Note that this does does not apply if we're declaring a
1129    // typedef (C++ [dcl.typedef]p4).
1130    if (Previous.isSingleTagDecl())
1131      Previous.clear();
1132  }
1133
1134  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1135                                   isExplicitSpecialization, Redeclaration,
1136                                   /*FIXME:*/OverloadableAttrRequired);
1137
1138  NamedDecl *PrincipalDecl = (TemplateParams
1139                              ? cast<NamedDecl>(FunctionTemplate)
1140                              : Function);
1141
1142  // If the original function was part of a friend declaration,
1143  // inherit its namespace state and add it to the owner.
1144  if (isFriend) {
1145    NamedDecl *PrevDecl;
1146    if (TemplateParams)
1147      PrevDecl = FunctionTemplate->getPreviousDeclaration();
1148    else
1149      PrevDecl = Function->getPreviousDeclaration();
1150
1151    PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0);
1152    DC->makeDeclVisibleInContext(PrincipalDecl, /*Recoverable=*/ false);
1153
1154    if (!SemaRef.getLangOptions().CPlusPlus0x &&
1155        D->isThisDeclarationADefinition()) {
1156      // Check for a function body.
1157      const FunctionDecl *Definition = 0;
1158      if (Function->getBody(Definition) &&
1159          Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1160        SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1161          << Function->getDeclName();
1162        SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1163        Function->setInvalidDecl();
1164      }
1165      // Check for redefinitions due to other instantiations of this or
1166      // a similar friend function.
1167      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1168                                           REnd = Function->redecls_end();
1169                R != REnd; ++R) {
1170        if (*R != Function &&
1171            ((*R)->getFriendObjectKind() != Decl::FOK_None)) {
1172          if (const FunctionDecl *RPattern
1173              = (*R)->getTemplateInstantiationPattern())
1174            if (RPattern->getBody(RPattern)) {
1175              SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1176                << Function->getDeclName();
1177              SemaRef.Diag((*R)->getLocation(), diag::note_previous_definition);
1178              Function->setInvalidDecl();
1179              break;
1180            }
1181        }
1182      }
1183    }
1184
1185  }
1186
1187  if (Function->isOverloadedOperator() && !DC->isRecord() &&
1188      PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1189    PrincipalDecl->setNonMemberOperator();
1190
1191  return Function;
1192}
1193
1194Decl *
1195TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1196                                      TemplateParameterList *TemplateParams) {
1197  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1198  void *InsertPos = 0;
1199  if (FunctionTemplate && !TemplateParams) {
1200    // We are creating a function template specialization from a function
1201    // template. Check whether there is already a function template
1202    // specialization for this particular set of template arguments.
1203    llvm::FoldingSetNodeID ID;
1204    FunctionTemplateSpecializationInfo::Profile(ID,
1205                            TemplateArgs.getInnermost().getFlatArgumentList(),
1206                                      TemplateArgs.getInnermost().flat_size(),
1207                                                SemaRef.Context);
1208
1209    FunctionTemplateSpecializationInfo *Info
1210      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
1211                                                                   InsertPos);
1212
1213    // If we already have a function template specialization, return it.
1214    if (Info)
1215      return Info->Function;
1216  }
1217
1218  bool isFriend;
1219  if (FunctionTemplate)
1220    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1221  else
1222    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1223
1224  bool MergeWithParentScope = (TemplateParams != 0) ||
1225    !(isa<Decl>(Owner) &&
1226      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1227  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1228
1229  llvm::SmallVector<ParmVarDecl *, 4> Params;
1230  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1231  TInfo = SubstFunctionType(D, Params);
1232  if (!TInfo)
1233    return 0;
1234  QualType T = TInfo->getType();
1235
1236  // \brief If the type of this function is not *directly* a function
1237  // type, then we're instantiating the a function that was declared
1238  // via a typedef, e.g.,
1239  //
1240  //   typedef int functype(int, int);
1241  //   functype func;
1242  //
1243  // In this case, we'll just go instantiate the ParmVarDecls that we
1244  // synthesized in the method declaration.
1245  if (!isa<FunctionProtoType>(T)) {
1246    assert(!Params.size() && "Instantiating type could not yield parameters");
1247    for (unsigned I = 0, N = D->getNumParams(); I != N; ++I) {
1248      ParmVarDecl *P = SemaRef.SubstParmVarDecl(D->getParamDecl(I),
1249                                                TemplateArgs);
1250      if (!P)
1251        return 0;
1252
1253      Params.push_back(P);
1254    }
1255  }
1256
1257  NestedNameSpecifier *Qualifier = D->getQualifier();
1258  if (Qualifier) {
1259    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1260                                                 D->getQualifierRange(),
1261                                                 TemplateArgs);
1262    if (!Qualifier) return 0;
1263  }
1264
1265  DeclContext *DC = Owner;
1266  if (isFriend) {
1267    if (Qualifier) {
1268      CXXScopeSpec SS;
1269      SS.setScopeRep(Qualifier);
1270      SS.setRange(D->getQualifierRange());
1271      DC = SemaRef.computeDeclContext(SS);
1272    } else {
1273      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1274                                           D->getDeclContext(),
1275                                           TemplateArgs);
1276    }
1277    if (!DC) return 0;
1278  }
1279
1280  // Build the instantiated method declaration.
1281  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1282  CXXMethodDecl *Method = 0;
1283
1284  DeclarationName Name = D->getDeclName();
1285  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1286    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1287    Name = SemaRef.Context.DeclarationNames.getCXXConstructorName(
1288                                    SemaRef.Context.getCanonicalType(ClassTy));
1289    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1290                                        Constructor->getLocation(),
1291                                        Name, T, TInfo,
1292                                        Constructor->isExplicit(),
1293                                        Constructor->isInlineSpecified(),
1294                                        false);
1295  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1296    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1297    Name = SemaRef.Context.DeclarationNames.getCXXDestructorName(
1298                                   SemaRef.Context.getCanonicalType(ClassTy));
1299    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1300                                       Destructor->getLocation(), Name,
1301                                       T, Destructor->isInlineSpecified(),
1302                                       false);
1303  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1304    CanQualType ConvTy
1305      = SemaRef.Context.getCanonicalType(
1306                                      T->getAs<FunctionType>()->getResultType());
1307    Name = SemaRef.Context.DeclarationNames.getCXXConversionFunctionName(
1308                                                                      ConvTy);
1309    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1310                                       Conversion->getLocation(), Name,
1311                                       T, TInfo,
1312                                       Conversion->isInlineSpecified(),
1313                                       Conversion->isExplicit());
1314  } else {
1315    Method = CXXMethodDecl::Create(SemaRef.Context, Record, D->getLocation(),
1316                                   D->getDeclName(), T, TInfo,
1317                                   D->isStatic(),
1318                                   D->getStorageClassAsWritten(),
1319                                   D->isInlineSpecified());
1320  }
1321
1322  if (Qualifier)
1323    Method->setQualifierInfo(Qualifier, D->getQualifierRange());
1324
1325  if (TemplateParams) {
1326    // Our resulting instantiation is actually a function template, since we
1327    // are substituting only the outer template parameters. For example, given
1328    //
1329    //   template<typename T>
1330    //   struct X {
1331    //     template<typename U> void f(T, U);
1332    //   };
1333    //
1334    //   X<int> x;
1335    //
1336    // We are instantiating the member template "f" within X<int>, which means
1337    // substituting int for T, but leaving "f" as a member function template.
1338    // Build the function template itself.
1339    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1340                                                    Method->getLocation(),
1341                                                    Method->getDeclName(),
1342                                                    TemplateParams, Method);
1343    if (isFriend) {
1344      FunctionTemplate->setLexicalDeclContext(Owner);
1345      FunctionTemplate->setObjectOfFriendDecl(true);
1346    } else if (D->isOutOfLine())
1347      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1348    Method->setDescribedFunctionTemplate(FunctionTemplate);
1349  } else if (FunctionTemplate) {
1350    // Record this function template specialization.
1351    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1352                                              &TemplateArgs.getInnermost(),
1353                                              InsertPos);
1354  } else if (!isFriend) {
1355    // Record that this is an instantiation of a member function.
1356    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1357  }
1358
1359  // If we are instantiating a member function defined
1360  // out-of-line, the instantiation will have the same lexical
1361  // context (which will be a namespace scope) as the template.
1362  if (isFriend) {
1363    Method->setLexicalDeclContext(Owner);
1364    Method->setObjectOfFriendDecl(true);
1365  } else if (D->isOutOfLine())
1366    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1367
1368  // Attach the parameters
1369  for (unsigned P = 0; P < Params.size(); ++P)
1370    Params[P]->setOwningFunction(Method);
1371  Method->setParams(Params.data(), Params.size());
1372
1373  if (InitMethodInstantiation(Method, D))
1374    Method->setInvalidDecl();
1375
1376  LookupResult Previous(SemaRef, Name, SourceLocation(),
1377                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1378
1379  if (!FunctionTemplate || TemplateParams || isFriend) {
1380    SemaRef.LookupQualifiedName(Previous, Record);
1381
1382    // In C++, the previous declaration we find might be a tag type
1383    // (class or enum). In this case, the new declaration will hide the
1384    // tag type. Note that this does does not apply if we're declaring a
1385    // typedef (C++ [dcl.typedef]p4).
1386    if (Previous.isSingleTagDecl())
1387      Previous.clear();
1388  }
1389
1390  bool Redeclaration = false;
1391  bool OverloadableAttrRequired = false;
1392  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1393                                   /*FIXME:*/OverloadableAttrRequired);
1394
1395  if (D->isPure())
1396    SemaRef.CheckPureMethod(Method, SourceRange());
1397
1398  Method->setAccess(D->getAccess());
1399
1400  if (FunctionTemplate) {
1401    // If there's a function template, let our caller handle it.
1402  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1403    // Don't hide a (potentially) valid declaration with an invalid one.
1404  } else {
1405    NamedDecl *DeclToAdd = (TemplateParams
1406                            ? cast<NamedDecl>(FunctionTemplate)
1407                            : Method);
1408    if (isFriend)
1409      Record->makeDeclVisibleInContext(DeclToAdd);
1410    else
1411      Owner->addDecl(DeclToAdd);
1412  }
1413
1414  return Method;
1415}
1416
1417Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1418  return VisitCXXMethodDecl(D);
1419}
1420
1421Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1422  return VisitCXXMethodDecl(D);
1423}
1424
1425Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1426  return VisitCXXMethodDecl(D);
1427}
1428
1429ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1430  return SemaRef.SubstParmVarDecl(D, TemplateArgs);
1431}
1432
1433Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1434                                                    TemplateTypeParmDecl *D) {
1435  // TODO: don't always clone when decls are refcounted.
1436  const Type* T = D->getTypeForDecl();
1437  assert(T->isTemplateTypeParmType());
1438  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1439
1440  TemplateTypeParmDecl *Inst =
1441    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1442                                 TTPT->getDepth() - 1, TTPT->getIndex(),
1443                                 TTPT->getName(),
1444                                 D->wasDeclaredWithTypename(),
1445                                 D->isParameterPack());
1446
1447  if (D->hasDefaultArgument())
1448    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1449
1450  // Introduce this template parameter's instantiation into the instantiation
1451  // scope.
1452  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1453
1454  return Inst;
1455}
1456
1457Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1458                                                 NonTypeTemplateParmDecl *D) {
1459  // Substitute into the type of the non-type template parameter.
1460  QualType T;
1461  TypeSourceInfo *DI = D->getTypeSourceInfo();
1462  if (DI) {
1463    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1464                           D->getDeclName());
1465    if (DI) T = DI->getType();
1466  } else {
1467    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1468                          D->getDeclName());
1469    DI = 0;
1470  }
1471  if (T.isNull())
1472    return 0;
1473
1474  // Check that this type is acceptable for a non-type template parameter.
1475  bool Invalid = false;
1476  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1477  if (T.isNull()) {
1478    T = SemaRef.Context.IntTy;
1479    Invalid = true;
1480  }
1481
1482  NonTypeTemplateParmDecl *Param
1483    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1484                                      D->getDepth() - 1, D->getPosition(),
1485                                      D->getIdentifier(), T, DI);
1486  if (Invalid)
1487    Param->setInvalidDecl();
1488
1489  Param->setDefaultArgument(D->getDefaultArgument());
1490
1491  // Introduce this template parameter's instantiation into the instantiation
1492  // scope.
1493  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1494  return Param;
1495}
1496
1497Decl *
1498TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1499                                                  TemplateTemplateParmDecl *D) {
1500  // Instantiate the template parameter list of the template template parameter.
1501  TemplateParameterList *TempParams = D->getTemplateParameters();
1502  TemplateParameterList *InstParams;
1503  {
1504    // Perform the actual substitution of template parameters within a new,
1505    // local instantiation scope.
1506    Sema::LocalInstantiationScope Scope(SemaRef);
1507    InstParams = SubstTemplateParams(TempParams);
1508    if (!InstParams)
1509      return NULL;
1510  }
1511
1512  // Build the template template parameter.
1513  TemplateTemplateParmDecl *Param
1514    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1515                                       D->getDepth() - 1, D->getPosition(),
1516                                       D->getIdentifier(), InstParams);
1517  Param->setDefaultArgument(D->getDefaultArgument());
1518
1519  // Introduce this template parameter's instantiation into the instantiation
1520  // scope.
1521  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1522
1523  return Param;
1524}
1525
1526Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1527  // Using directives are never dependent, so they require no explicit
1528
1529  UsingDirectiveDecl *Inst
1530    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1531                                 D->getNamespaceKeyLocation(),
1532                                 D->getQualifierRange(), D->getQualifier(),
1533                                 D->getIdentLocation(),
1534                                 D->getNominatedNamespace(),
1535                                 D->getCommonAncestor());
1536  Owner->addDecl(Inst);
1537  return Inst;
1538}
1539
1540Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1541  // The nested name specifier is non-dependent, so no transformation
1542  // is required.
1543
1544  // We only need to do redeclaration lookups if we're in a class
1545  // scope (in fact, it's not really even possible in non-class
1546  // scopes).
1547  bool CheckRedeclaration = Owner->isRecord();
1548
1549  LookupResult Prev(SemaRef, D->getDeclName(), D->getLocation(),
1550                    Sema::LookupUsingDeclName, Sema::ForRedeclaration);
1551
1552  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1553                                       D->getLocation(),
1554                                       D->getNestedNameRange(),
1555                                       D->getUsingLocation(),
1556                                       D->getTargetNestedNameDecl(),
1557                                       D->getDeclName(),
1558                                       D->isTypeName());
1559
1560  CXXScopeSpec SS;
1561  SS.setScopeRep(D->getTargetNestedNameDecl());
1562  SS.setRange(D->getNestedNameRange());
1563
1564  if (CheckRedeclaration) {
1565    Prev.setHideTags(false);
1566    SemaRef.LookupQualifiedName(Prev, Owner);
1567
1568    // Check for invalid redeclarations.
1569    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1570                                            D->isTypeName(), SS,
1571                                            D->getLocation(), Prev))
1572      NewUD->setInvalidDecl();
1573
1574  }
1575
1576  if (!NewUD->isInvalidDecl() &&
1577      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1578                                      D->getLocation()))
1579    NewUD->setInvalidDecl();
1580
1581  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1582  NewUD->setAccess(D->getAccess());
1583  Owner->addDecl(NewUD);
1584
1585  // Don't process the shadow decls for an invalid decl.
1586  if (NewUD->isInvalidDecl())
1587    return NewUD;
1588
1589  bool isFunctionScope = Owner->isFunctionOrMethod();
1590
1591  // Process the shadow decls.
1592  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1593         I != E; ++I) {
1594    UsingShadowDecl *Shadow = *I;
1595    NamedDecl *InstTarget =
1596      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1597                                                   Shadow->getTargetDecl(),
1598                                                   TemplateArgs));
1599
1600    if (CheckRedeclaration &&
1601        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1602      continue;
1603
1604    UsingShadowDecl *InstShadow
1605      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1606    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1607
1608    if (isFunctionScope)
1609      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1610  }
1611
1612  return NewUD;
1613}
1614
1615Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1616  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1617  return 0;
1618}
1619
1620Decl * TemplateDeclInstantiator
1621    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1622  NestedNameSpecifier *NNS =
1623    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1624                                     D->getTargetNestedNameRange(),
1625                                     TemplateArgs);
1626  if (!NNS)
1627    return 0;
1628
1629  CXXScopeSpec SS;
1630  SS.setRange(D->getTargetNestedNameRange());
1631  SS.setScopeRep(NNS);
1632
1633  NamedDecl *UD =
1634    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1635                                  D->getUsingLoc(), SS, D->getLocation(),
1636                                  D->getDeclName(), 0,
1637                                  /*instantiation*/ true,
1638                                  /*typename*/ true, D->getTypenameLoc());
1639  if (UD)
1640    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1641
1642  return UD;
1643}
1644
1645Decl * TemplateDeclInstantiator
1646    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1647  NestedNameSpecifier *NNS =
1648    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1649                                     D->getTargetNestedNameRange(),
1650                                     TemplateArgs);
1651  if (!NNS)
1652    return 0;
1653
1654  CXXScopeSpec SS;
1655  SS.setRange(D->getTargetNestedNameRange());
1656  SS.setScopeRep(NNS);
1657
1658  NamedDecl *UD =
1659    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1660                                  D->getUsingLoc(), SS, D->getLocation(),
1661                                  D->getDeclName(), 0,
1662                                  /*instantiation*/ true,
1663                                  /*typename*/ false, SourceLocation());
1664  if (UD)
1665    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1666
1667  return UD;
1668}
1669
1670Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1671                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1672  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1673  if (D->isInvalidDecl())
1674    return 0;
1675
1676  return Instantiator.Visit(D);
1677}
1678
1679/// \brief Instantiates a nested template parameter list in the current
1680/// instantiation context.
1681///
1682/// \param L The parameter list to instantiate
1683///
1684/// \returns NULL if there was an error
1685TemplateParameterList *
1686TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1687  // Get errors for all the parameters before bailing out.
1688  bool Invalid = false;
1689
1690  unsigned N = L->size();
1691  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1692  ParamVector Params;
1693  Params.reserve(N);
1694  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1695       PI != PE; ++PI) {
1696    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1697    Params.push_back(D);
1698    Invalid = Invalid || !D || D->isInvalidDecl();
1699  }
1700
1701  // Clean up if we had an error.
1702  if (Invalid) {
1703    for (ParamVector::iterator PI = Params.begin(), PE = Params.end();
1704         PI != PE; ++PI)
1705      if (*PI)
1706        (*PI)->Destroy(SemaRef.Context);
1707    return NULL;
1708  }
1709
1710  TemplateParameterList *InstL
1711    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1712                                    L->getLAngleLoc(), &Params.front(), N,
1713                                    L->getRAngleLoc());
1714  return InstL;
1715}
1716
1717/// \brief Instantiate the declaration of a class template partial
1718/// specialization.
1719///
1720/// \param ClassTemplate the (instantiated) class template that is partially
1721// specialized by the instantiation of \p PartialSpec.
1722///
1723/// \param PartialSpec the (uninstantiated) class template partial
1724/// specialization that we are instantiating.
1725///
1726/// \returns true if there was an error, false otherwise.
1727bool
1728TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1729                                            ClassTemplateDecl *ClassTemplate,
1730                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1731  // Create a local instantiation scope for this class template partial
1732  // specialization, which will contain the instantiations of the template
1733  // parameters.
1734  Sema::LocalInstantiationScope Scope(SemaRef);
1735
1736  // Substitute into the template parameters of the class template partial
1737  // specialization.
1738  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1739  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1740  if (!InstParams)
1741    return true;
1742
1743  // Substitute into the template arguments of the class template partial
1744  // specialization.
1745  const TemplateArgumentLoc *PartialSpecTemplateArgs
1746    = PartialSpec->getTemplateArgsAsWritten();
1747  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1748
1749  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1750  for (unsigned I = 0; I != N; ++I) {
1751    TemplateArgumentLoc Loc;
1752    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1753      return true;
1754    InstTemplateArgs.addArgument(Loc);
1755  }
1756
1757
1758  // Check that the template argument list is well-formed for this
1759  // class template.
1760  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1761                                        InstTemplateArgs.size());
1762  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1763                                        PartialSpec->getLocation(),
1764                                        InstTemplateArgs,
1765                                        false,
1766                                        Converted))
1767    return true;
1768
1769  // Figure out where to insert this class template partial specialization
1770  // in the member template's set of class template partial specializations.
1771  llvm::FoldingSetNodeID ID;
1772  ClassTemplatePartialSpecializationDecl::Profile(ID,
1773                                                  Converted.getFlatArguments(),
1774                                                  Converted.flatSize(),
1775                                                  SemaRef.Context);
1776  void *InsertPos = 0;
1777  ClassTemplateSpecializationDecl *PrevDecl
1778    = ClassTemplate->getPartialSpecializations().FindNodeOrInsertPos(ID,
1779                                                                     InsertPos);
1780
1781  // Build the canonical type that describes the converted template
1782  // arguments of the class template partial specialization.
1783  QualType CanonType
1784    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1785                                                  Converted.getFlatArguments(),
1786                                                    Converted.flatSize());
1787
1788  // Build the fully-sugared type for this class template
1789  // specialization as the user wrote in the specialization
1790  // itself. This means that we'll pretty-print the type retrieved
1791  // from the specialization's declaration the way that the user
1792  // actually wrote the specialization, rather than formatting the
1793  // name based on the "canonical" representation used to store the
1794  // template arguments in the specialization.
1795  TypeSourceInfo *WrittenTy
1796    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1797                                                    TemplateName(ClassTemplate),
1798                                                    PartialSpec->getLocation(),
1799                                                    InstTemplateArgs,
1800                                                    CanonType);
1801
1802  if (PrevDecl) {
1803    // We've already seen a partial specialization with the same template
1804    // parameters and template arguments. This can happen, for example, when
1805    // substituting the outer template arguments ends up causing two
1806    // class template partial specializations of a member class template
1807    // to have identical forms, e.g.,
1808    //
1809    //   template<typename T, typename U>
1810    //   struct Outer {
1811    //     template<typename X, typename Y> struct Inner;
1812    //     template<typename Y> struct Inner<T, Y>;
1813    //     template<typename Y> struct Inner<U, Y>;
1814    //   };
1815    //
1816    //   Outer<int, int> outer; // error: the partial specializations of Inner
1817    //                          // have the same signature.
1818    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1819      << WrittenTy;
1820    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1821      << SemaRef.Context.getTypeDeclType(PrevDecl);
1822    return true;
1823  }
1824
1825
1826  // Create the class template partial specialization declaration.
1827  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1828    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
1829                                                     PartialSpec->getTagKind(),
1830                                                     Owner,
1831                                                     PartialSpec->getLocation(),
1832                                                     InstParams,
1833                                                     ClassTemplate,
1834                                                     Converted,
1835                                                     InstTemplateArgs,
1836                                                     CanonType,
1837                                                     0,
1838                             ClassTemplate->getPartialSpecializations().size());
1839  // Substitute the nested name specifier, if any.
1840  if (SubstQualifier(PartialSpec, InstPartialSpec))
1841    return 0;
1842
1843  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1844  InstPartialSpec->setTypeAsWritten(WrittenTy);
1845
1846  // Add this partial specialization to the set of class template partial
1847  // specializations.
1848  ClassTemplate->getPartialSpecializations().InsertNode(InstPartialSpec,
1849                                                        InsertPos);
1850  return false;
1851}
1852
1853TypeSourceInfo*
1854TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1855                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1856  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1857  assert(OldTInfo && "substituting function without type source info");
1858  assert(Params.empty() && "parameter vector is non-empty at start");
1859  TypeSourceInfo *NewTInfo
1860    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
1861                                    D->getTypeSpecStartLoc(),
1862                                    D->getDeclName());
1863  if (!NewTInfo)
1864    return 0;
1865
1866  if (NewTInfo != OldTInfo) {
1867    // Get parameters from the new type info.
1868    TypeLoc OldTL = OldTInfo->getTypeLoc();
1869    if (FunctionProtoTypeLoc *OldProtoLoc
1870                                  = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1871      TypeLoc NewTL = NewTInfo->getTypeLoc();
1872      FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1873      assert(NewProtoLoc && "Missing prototype?");
1874      for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i) {
1875        // FIXME: Variadic templates will break this.
1876        Params.push_back(NewProtoLoc->getArg(i));
1877        SemaRef.CurrentInstantiationScope->InstantiatedLocal(
1878                                                        OldProtoLoc->getArg(i),
1879                                                        NewProtoLoc->getArg(i));
1880      }
1881    }
1882  } else {
1883    // The function type itself was not dependent and therefore no
1884    // substitution occurred. However, we still need to instantiate
1885    // the function parameters themselves.
1886    TypeLoc OldTL = OldTInfo->getTypeLoc();
1887    if (FunctionProtoTypeLoc *OldProtoLoc
1888                                    = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1889      for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
1890        ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
1891        if (!Parm)
1892          return 0;
1893        Params.push_back(Parm);
1894      }
1895    }
1896  }
1897  return NewTInfo;
1898}
1899
1900/// \brief Initializes the common fields of an instantiation function
1901/// declaration (New) from the corresponding fields of its template (Tmpl).
1902///
1903/// \returns true if there was an error
1904bool
1905TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1906                                                    FunctionDecl *Tmpl) {
1907  if (Tmpl->isDeleted())
1908    New->setDeleted();
1909
1910  // If we are performing substituting explicitly-specified template arguments
1911  // or deduced template arguments into a function template and we reach this
1912  // point, we are now past the point where SFINAE applies and have committed
1913  // to keeping the new function template specialization. We therefore
1914  // convert the active template instantiation for the function template
1915  // into a template instantiation for this specific function template
1916  // specialization, which is not a SFINAE context, so that we diagnose any
1917  // further errors in the declaration itself.
1918  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1919  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1920  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1921      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1922    if (FunctionTemplateDecl *FunTmpl
1923          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1924      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1925             "Deduction from the wrong function template?");
1926      (void) FunTmpl;
1927      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1928      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1929      --SemaRef.NonInstantiationEntries;
1930    }
1931  }
1932
1933  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1934  assert(Proto && "Function template without prototype?");
1935
1936  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1937      Proto->getNoReturnAttr()) {
1938    // The function has an exception specification or a "noreturn"
1939    // attribute. Substitute into each of the exception types.
1940    llvm::SmallVector<QualType, 4> Exceptions;
1941    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1942      // FIXME: Poor location information!
1943      QualType T
1944        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1945                            New->getLocation(), New->getDeclName());
1946      if (T.isNull() ||
1947          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1948        continue;
1949
1950      Exceptions.push_back(T);
1951    }
1952
1953    // Rebuild the function type
1954
1955    const FunctionProtoType *NewProto
1956      = New->getType()->getAs<FunctionProtoType>();
1957    assert(NewProto && "Template instantiation without function prototype?");
1958    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1959                                                 NewProto->arg_type_begin(),
1960                                                 NewProto->getNumArgs(),
1961                                                 NewProto->isVariadic(),
1962                                                 NewProto->getTypeQuals(),
1963                                                 Proto->hasExceptionSpec(),
1964                                                 Proto->hasAnyExceptionSpec(),
1965                                                 Exceptions.size(),
1966                                                 Exceptions.data(),
1967                                                 Proto->getExtInfo()));
1968  }
1969
1970  return false;
1971}
1972
1973/// \brief Initializes common fields of an instantiated method
1974/// declaration (New) from the corresponding fields of its template
1975/// (Tmpl).
1976///
1977/// \returns true if there was an error
1978bool
1979TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
1980                                                  CXXMethodDecl *Tmpl) {
1981  if (InitFunctionInstantiation(New, Tmpl))
1982    return true;
1983
1984  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
1985  New->setAccess(Tmpl->getAccess());
1986  if (Tmpl->isVirtualAsWritten())
1987    Record->setMethodAsVirtual(New);
1988
1989  // FIXME: attributes
1990  // FIXME: New needs a pointer to Tmpl
1991  return false;
1992}
1993
1994/// \brief Instantiate the definition of the given function from its
1995/// template.
1996///
1997/// \param PointOfInstantiation the point at which the instantiation was
1998/// required. Note that this is not precisely a "point of instantiation"
1999/// for the function, but it's close.
2000///
2001/// \param Function the already-instantiated declaration of a
2002/// function template specialization or member function of a class template
2003/// specialization.
2004///
2005/// \param Recursive if true, recursively instantiates any functions that
2006/// are required by this instantiation.
2007///
2008/// \param DefinitionRequired if true, then we are performing an explicit
2009/// instantiation where the body of the function is required. Complain if
2010/// there is no such body.
2011void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
2012                                         FunctionDecl *Function,
2013                                         bool Recursive,
2014                                         bool DefinitionRequired) {
2015  if (Function->isInvalidDecl() || Function->getBody())
2016    return;
2017
2018  // Never instantiate an explicit specialization.
2019  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2020    return;
2021
2022  // Find the function body that we'll be substituting.
2023  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
2024  Stmt *Pattern = 0;
2025  if (PatternDecl)
2026    Pattern = PatternDecl->getBody(PatternDecl);
2027
2028  if (!Pattern) {
2029    if (DefinitionRequired) {
2030      if (Function->getPrimaryTemplate())
2031        Diag(PointOfInstantiation,
2032             diag::err_explicit_instantiation_undefined_func_template)
2033          << Function->getPrimaryTemplate();
2034      else
2035        Diag(PointOfInstantiation,
2036             diag::err_explicit_instantiation_undefined_member)
2037          << 1 << Function->getDeclName() << Function->getDeclContext();
2038
2039      if (PatternDecl)
2040        Diag(PatternDecl->getLocation(),
2041             diag::note_explicit_instantiation_here);
2042      Function->setInvalidDecl();
2043    }
2044
2045    return;
2046  }
2047
2048  // C++0x [temp.explicit]p9:
2049  //   Except for inline functions, other explicit instantiation declarations
2050  //   have the effect of suppressing the implicit instantiation of the entity
2051  //   to which they refer.
2052  if (Function->getTemplateSpecializationKind()
2053        == TSK_ExplicitInstantiationDeclaration &&
2054      !PatternDecl->isInlined())
2055    return;
2056
2057  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2058  if (Inst)
2059    return;
2060
2061  // If we're performing recursive template instantiation, create our own
2062  // queue of pending implicit instantiations that we will instantiate later,
2063  // while we're still within our own instantiation context.
2064  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2065  if (Recursive)
2066    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2067
2068  EnterExpressionEvaluationContext EvalContext(*this,
2069                                               Action::PotentiallyEvaluated);
2070  ActOnStartOfFunctionDef(0, DeclPtrTy::make(Function));
2071
2072  // Introduce a new scope where local variable instantiations will be
2073  // recorded, unless we're actually a member function within a local
2074  // class, in which case we need to merge our results with the parent
2075  // scope (of the enclosing function).
2076  bool MergeWithParentScope = false;
2077  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2078    MergeWithParentScope = Rec->isLocalClass();
2079
2080  LocalInstantiationScope Scope(*this, MergeWithParentScope);
2081
2082  // Introduce the instantiated function parameters into the local
2083  // instantiation scope.
2084  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I)
2085    Scope.InstantiatedLocal(PatternDecl->getParamDecl(I),
2086                            Function->getParamDecl(I));
2087
2088  // Enter the scope of this instantiation. We don't use
2089  // PushDeclContext because we don't have a scope.
2090  DeclContext *PreviousContext = CurContext;
2091  CurContext = Function;
2092
2093  MultiLevelTemplateArgumentList TemplateArgs =
2094    getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
2095
2096  // If this is a constructor, instantiate the member initializers.
2097  if (const CXXConstructorDecl *Ctor =
2098        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2099    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2100                               TemplateArgs);
2101  }
2102
2103  // Instantiate the function body.
2104  OwningStmtResult Body = SubstStmt(Pattern, TemplateArgs);
2105
2106  if (Body.isInvalid())
2107    Function->setInvalidDecl();
2108
2109  ActOnFinishFunctionBody(DeclPtrTy::make(Function), move(Body),
2110                          /*IsInstantiation=*/true);
2111
2112  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2113
2114  CurContext = PreviousContext;
2115
2116  DeclGroupRef DG(Function);
2117  Consumer.HandleTopLevelDecl(DG);
2118
2119  // This class may have local implicit instantiations that need to be
2120  // instantiation within this scope.
2121  PerformPendingImplicitInstantiations(/*LocalOnly=*/true);
2122  Scope.Exit();
2123
2124  if (Recursive) {
2125    // Instantiate any pending implicit instantiations found during the
2126    // instantiation of this template.
2127    PerformPendingImplicitInstantiations();
2128
2129    // Restore the set of pending implicit instantiations.
2130    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2131  }
2132}
2133
2134/// \brief Instantiate the definition of the given variable from its
2135/// template.
2136///
2137/// \param PointOfInstantiation the point at which the instantiation was
2138/// required. Note that this is not precisely a "point of instantiation"
2139/// for the function, but it's close.
2140///
2141/// \param Var the already-instantiated declaration of a static member
2142/// variable of a class template specialization.
2143///
2144/// \param Recursive if true, recursively instantiates any functions that
2145/// are required by this instantiation.
2146///
2147/// \param DefinitionRequired if true, then we are performing an explicit
2148/// instantiation where an out-of-line definition of the member variable
2149/// is required. Complain if there is no such definition.
2150void Sema::InstantiateStaticDataMemberDefinition(
2151                                          SourceLocation PointOfInstantiation,
2152                                                 VarDecl *Var,
2153                                                 bool Recursive,
2154                                                 bool DefinitionRequired) {
2155  if (Var->isInvalidDecl())
2156    return;
2157
2158  // Find the out-of-line definition of this static data member.
2159  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2160  assert(Def && "This data member was not instantiated from a template?");
2161  assert(Def->isStaticDataMember() && "Not a static data member?");
2162  Def = Def->getOutOfLineDefinition();
2163
2164  if (!Def) {
2165    // We did not find an out-of-line definition of this static data member,
2166    // so we won't perform any instantiation. Rather, we rely on the user to
2167    // instantiate this definition (or provide a specialization for it) in
2168    // another translation unit.
2169    if (DefinitionRequired) {
2170      Def = Var->getInstantiatedFromStaticDataMember();
2171      Diag(PointOfInstantiation,
2172           diag::err_explicit_instantiation_undefined_member)
2173        << 2 << Var->getDeclName() << Var->getDeclContext();
2174      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2175    }
2176
2177    return;
2178  }
2179
2180  // Never instantiate an explicit specialization.
2181  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2182    return;
2183
2184  // C++0x [temp.explicit]p9:
2185  //   Except for inline functions, other explicit instantiation declarations
2186  //   have the effect of suppressing the implicit instantiation of the entity
2187  //   to which they refer.
2188  if (Var->getTemplateSpecializationKind()
2189        == TSK_ExplicitInstantiationDeclaration)
2190    return;
2191
2192  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2193  if (Inst)
2194    return;
2195
2196  // If we're performing recursive template instantiation, create our own
2197  // queue of pending implicit instantiations that we will instantiate later,
2198  // while we're still within our own instantiation context.
2199  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2200  if (Recursive)
2201    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2202
2203  // Enter the scope of this instantiation. We don't use
2204  // PushDeclContext because we don't have a scope.
2205  DeclContext *PreviousContext = CurContext;
2206  CurContext = Var->getDeclContext();
2207
2208  VarDecl *OldVar = Var;
2209  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2210                                          getTemplateInstantiationArgs(Var)));
2211  CurContext = PreviousContext;
2212
2213  if (Var) {
2214    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2215    assert(MSInfo && "Missing member specialization information?");
2216    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2217                                       MSInfo->getPointOfInstantiation());
2218    DeclGroupRef DG(Var);
2219    Consumer.HandleTopLevelDecl(DG);
2220  }
2221
2222  if (Recursive) {
2223    // Instantiate any pending implicit instantiations found during the
2224    // instantiation of this template.
2225    PerformPendingImplicitInstantiations();
2226
2227    // Restore the set of pending implicit instantiations.
2228    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2229  }
2230}
2231
2232void
2233Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2234                                 const CXXConstructorDecl *Tmpl,
2235                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2236
2237  llvm::SmallVector<MemInitTy*, 4> NewInits;
2238  bool AnyErrors = false;
2239
2240  // Instantiate all the initializers.
2241  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2242                                            InitsEnd = Tmpl->init_end();
2243       Inits != InitsEnd; ++Inits) {
2244    CXXBaseOrMemberInitializer *Init = *Inits;
2245
2246    SourceLocation LParenLoc, RParenLoc;
2247    ASTOwningVector<&ActionBase::DeleteExpr> NewArgs(*this);
2248    llvm::SmallVector<SourceLocation, 4> CommaLocs;
2249
2250    // Instantiate the initializer.
2251    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2252                               LParenLoc, CommaLocs, NewArgs, RParenLoc)) {
2253      AnyErrors = true;
2254      continue;
2255    }
2256
2257    MemInitResult NewInit;
2258    if (Init->isBaseInitializer()) {
2259      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2260                                            TemplateArgs,
2261                                            Init->getSourceLocation(),
2262                                            New->getDeclName());
2263      if (!BaseTInfo) {
2264        AnyErrors = true;
2265        New->setInvalidDecl();
2266        continue;
2267      }
2268
2269      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2270                                     (Expr **)NewArgs.data(),
2271                                     NewArgs.size(),
2272                                     Init->getLParenLoc(),
2273                                     Init->getRParenLoc(),
2274                                     New->getParent());
2275    } else if (Init->isMemberInitializer()) {
2276      FieldDecl *Member;
2277
2278      // Is this an anonymous union?
2279      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2280        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2281                                                      UnionInit, TemplateArgs));
2282      else
2283        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2284                                                      Init->getMember(),
2285                                                      TemplateArgs));
2286
2287      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2288                                       NewArgs.size(),
2289                                       Init->getSourceLocation(),
2290                                       Init->getLParenLoc(),
2291                                       Init->getRParenLoc());
2292    }
2293
2294    if (NewInit.isInvalid()) {
2295      AnyErrors = true;
2296      New->setInvalidDecl();
2297    } else {
2298      // FIXME: It would be nice if ASTOwningVector had a release function.
2299      NewArgs.take();
2300
2301      NewInits.push_back((MemInitTy *)NewInit.get());
2302    }
2303  }
2304
2305  // Assign all the initializers to the new constructor.
2306  ActOnMemInitializers(DeclPtrTy::make(New),
2307                       /*FIXME: ColonLoc */
2308                       SourceLocation(),
2309                       NewInits.data(), NewInits.size(),
2310                       AnyErrors);
2311}
2312
2313// TODO: this could be templated if the various decl types used the
2314// same method name.
2315static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2316                              ClassTemplateDecl *Instance) {
2317  Pattern = Pattern->getCanonicalDecl();
2318
2319  do {
2320    Instance = Instance->getCanonicalDecl();
2321    if (Pattern == Instance) return true;
2322    Instance = Instance->getInstantiatedFromMemberTemplate();
2323  } while (Instance);
2324
2325  return false;
2326}
2327
2328static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2329                              FunctionTemplateDecl *Instance) {
2330  Pattern = Pattern->getCanonicalDecl();
2331
2332  do {
2333    Instance = Instance->getCanonicalDecl();
2334    if (Pattern == Instance) return true;
2335    Instance = Instance->getInstantiatedFromMemberTemplate();
2336  } while (Instance);
2337
2338  return false;
2339}
2340
2341static bool
2342isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2343                  ClassTemplatePartialSpecializationDecl *Instance) {
2344  Pattern
2345    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2346  do {
2347    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2348                                                Instance->getCanonicalDecl());
2349    if (Pattern == Instance)
2350      return true;
2351    Instance = Instance->getInstantiatedFromMember();
2352  } while (Instance);
2353
2354  return false;
2355}
2356
2357static bool isInstantiationOf(CXXRecordDecl *Pattern,
2358                              CXXRecordDecl *Instance) {
2359  Pattern = Pattern->getCanonicalDecl();
2360
2361  do {
2362    Instance = Instance->getCanonicalDecl();
2363    if (Pattern == Instance) return true;
2364    Instance = Instance->getInstantiatedFromMemberClass();
2365  } while (Instance);
2366
2367  return false;
2368}
2369
2370static bool isInstantiationOf(FunctionDecl *Pattern,
2371                              FunctionDecl *Instance) {
2372  Pattern = Pattern->getCanonicalDecl();
2373
2374  do {
2375    Instance = Instance->getCanonicalDecl();
2376    if (Pattern == Instance) return true;
2377    Instance = Instance->getInstantiatedFromMemberFunction();
2378  } while (Instance);
2379
2380  return false;
2381}
2382
2383static bool isInstantiationOf(EnumDecl *Pattern,
2384                              EnumDecl *Instance) {
2385  Pattern = Pattern->getCanonicalDecl();
2386
2387  do {
2388    Instance = Instance->getCanonicalDecl();
2389    if (Pattern == Instance) return true;
2390    Instance = Instance->getInstantiatedFromMemberEnum();
2391  } while (Instance);
2392
2393  return false;
2394}
2395
2396static bool isInstantiationOf(UsingShadowDecl *Pattern,
2397                              UsingShadowDecl *Instance,
2398                              ASTContext &C) {
2399  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2400}
2401
2402static bool isInstantiationOf(UsingDecl *Pattern,
2403                              UsingDecl *Instance,
2404                              ASTContext &C) {
2405  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2406}
2407
2408static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2409                              UsingDecl *Instance,
2410                              ASTContext &C) {
2411  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2412}
2413
2414static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2415                              UsingDecl *Instance,
2416                              ASTContext &C) {
2417  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2418}
2419
2420static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2421                                              VarDecl *Instance) {
2422  assert(Instance->isStaticDataMember());
2423
2424  Pattern = Pattern->getCanonicalDecl();
2425
2426  do {
2427    Instance = Instance->getCanonicalDecl();
2428    if (Pattern == Instance) return true;
2429    Instance = Instance->getInstantiatedFromStaticDataMember();
2430  } while (Instance);
2431
2432  return false;
2433}
2434
2435// Other is the prospective instantiation
2436// D is the prospective pattern
2437static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2438  if (D->getKind() != Other->getKind()) {
2439    if (UnresolvedUsingTypenameDecl *UUD
2440          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2441      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2442        return isInstantiationOf(UUD, UD, Ctx);
2443      }
2444    }
2445
2446    if (UnresolvedUsingValueDecl *UUD
2447          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2448      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2449        return isInstantiationOf(UUD, UD, Ctx);
2450      }
2451    }
2452
2453    return false;
2454  }
2455
2456  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2457    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2458
2459  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2460    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2461
2462  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2463    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2464
2465  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2466    if (Var->isStaticDataMember())
2467      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2468
2469  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2470    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2471
2472  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2473    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2474
2475  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2476        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2477    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2478                             PartialSpec);
2479
2480  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2481    if (!Field->getDeclName()) {
2482      // This is an unnamed field.
2483      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2484        cast<FieldDecl>(D);
2485    }
2486  }
2487
2488  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2489    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2490
2491  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2492    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2493
2494  return D->getDeclName() && isa<NamedDecl>(Other) &&
2495    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2496}
2497
2498template<typename ForwardIterator>
2499static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2500                                      NamedDecl *D,
2501                                      ForwardIterator first,
2502                                      ForwardIterator last) {
2503  for (; first != last; ++first)
2504    if (isInstantiationOf(Ctx, D, *first))
2505      return cast<NamedDecl>(*first);
2506
2507  return 0;
2508}
2509
2510/// \brief Finds the instantiation of the given declaration context
2511/// within the current instantiation.
2512///
2513/// \returns NULL if there was an error
2514DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2515                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2516  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2517    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2518    return cast_or_null<DeclContext>(ID);
2519  } else return DC;
2520}
2521
2522/// \brief Find the instantiation of the given declaration within the
2523/// current instantiation.
2524///
2525/// This routine is intended to be used when \p D is a declaration
2526/// referenced from within a template, that needs to mapped into the
2527/// corresponding declaration within an instantiation. For example,
2528/// given:
2529///
2530/// \code
2531/// template<typename T>
2532/// struct X {
2533///   enum Kind {
2534///     KnownValue = sizeof(T)
2535///   };
2536///
2537///   bool getKind() const { return KnownValue; }
2538/// };
2539///
2540/// template struct X<int>;
2541/// \endcode
2542///
2543/// In the instantiation of X<int>::getKind(), we need to map the
2544/// EnumConstantDecl for KnownValue (which refers to
2545/// X<T>::<Kind>::KnownValue) to its instantiation
2546/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2547/// this mapping from within the instantiation of X<int>.
2548NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2549                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2550  DeclContext *ParentDC = D->getDeclContext();
2551  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2552      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2553      ParentDC->isFunctionOrMethod()) {
2554    // D is a local of some kind. Look into the map of local
2555    // declarations to their instantiations.
2556    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2557  }
2558
2559  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2560    if (!Record->isDependentContext())
2561      return D;
2562
2563    // If the RecordDecl is actually the injected-class-name or a
2564    // "templated" declaration for a class template, class template
2565    // partial specialization, or a member class of a class template,
2566    // substitute into the injected-class-name of the class template
2567    // or partial specialization to find the new DeclContext.
2568    QualType T;
2569    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2570
2571    if (ClassTemplate) {
2572      T = ClassTemplate->getInjectedClassNameSpecialization(Context);
2573    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2574                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2575      ClassTemplate = PartialSpec->getSpecializedTemplate();
2576
2577      // If we call SubstType with an InjectedClassNameType here we
2578      // can end up in an infinite loop.
2579      T = Context.getTypeDeclType(Record);
2580      assert(isa<InjectedClassNameType>(T) &&
2581             "type of partial specialization is not an InjectedClassNameType");
2582      T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
2583    }
2584
2585    if (!T.isNull()) {
2586      // Substitute into the injected-class-name to get the type
2587      // corresponding to the instantiation we want, which may also be
2588      // the current instantiation (if we're in a template
2589      // definition). This substitution should never fail, since we
2590      // know we can instantiate the injected-class-name or we
2591      // wouldn't have gotten to the injected-class-name!
2592
2593      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2594      // extra instantiation in the common case?
2595      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2596      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2597
2598      if (!T->isDependentType()) {
2599        assert(T->isRecordType() && "Instantiation must produce a record type");
2600        return T->getAs<RecordType>()->getDecl();
2601      }
2602
2603      // We are performing "partial" template instantiation to create
2604      // the member declarations for the members of a class template
2605      // specialization. Therefore, D is actually referring to something
2606      // in the current instantiation. Look through the current
2607      // context, which contains actual instantiations, to find the
2608      // instantiation of the "current instantiation" that D refers
2609      // to.
2610      bool SawNonDependentContext = false;
2611      for (DeclContext *DC = CurContext; !DC->isFileContext();
2612           DC = DC->getParent()) {
2613        if (ClassTemplateSpecializationDecl *Spec
2614                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2615          if (isInstantiationOf(ClassTemplate,
2616                                Spec->getSpecializedTemplate()))
2617            return Spec;
2618
2619        if (!DC->isDependentContext())
2620          SawNonDependentContext = true;
2621      }
2622
2623      // We're performing "instantiation" of a member of the current
2624      // instantiation while we are type-checking the
2625      // definition. Compute the declaration context and return that.
2626      assert(!SawNonDependentContext &&
2627             "No dependent context while instantiating record");
2628      DeclContext *DC = computeDeclContext(T);
2629      assert(DC &&
2630             "Unable to find declaration for the current instantiation");
2631      return cast<CXXRecordDecl>(DC);
2632    }
2633
2634    // Fall through to deal with other dependent record types (e.g.,
2635    // anonymous unions in class templates).
2636  }
2637
2638  if (!ParentDC->isDependentContext())
2639    return D;
2640
2641  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2642  if (!ParentDC)
2643    return 0;
2644
2645  if (ParentDC != D->getDeclContext()) {
2646    // We performed some kind of instantiation in the parent context,
2647    // so now we need to look into the instantiated parent context to
2648    // find the instantiation of the declaration D.
2649
2650    // If our context used to be dependent, we may need to instantiate
2651    // it before performing lookup into that context.
2652    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2653      if (!Spec->isDependentContext()) {
2654        QualType T = Context.getTypeDeclType(Spec);
2655        const RecordType *Tag = T->getAs<RecordType>();
2656        assert(Tag && "type of non-dependent record is not a RecordType");
2657        if (!Tag->isBeingDefined() &&
2658            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2659          return 0;
2660      }
2661    }
2662
2663    NamedDecl *Result = 0;
2664    if (D->getDeclName()) {
2665      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2666      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2667    } else {
2668      // Since we don't have a name for the entity we're looking for,
2669      // our only option is to walk through all of the declarations to
2670      // find that name. This will occur in a few cases:
2671      //
2672      //   - anonymous struct/union within a template
2673      //   - unnamed class/struct/union/enum within a template
2674      //
2675      // FIXME: Find a better way to find these instantiations!
2676      Result = findInstantiationOf(Context, D,
2677                                   ParentDC->decls_begin(),
2678                                   ParentDC->decls_end());
2679    }
2680
2681    // UsingShadowDecls can instantiate to nothing because of using hiding.
2682    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2683            cast<Decl>(ParentDC)->isInvalidDecl())
2684           && "Unable to find instantiation of declaration!");
2685
2686    D = Result;
2687  }
2688
2689  return D;
2690}
2691
2692/// \brief Performs template instantiation for all implicit template
2693/// instantiations we have seen until this point.
2694void Sema::PerformPendingImplicitInstantiations(bool LocalOnly) {
2695  while (!PendingLocalImplicitInstantiations.empty() ||
2696         (!LocalOnly && !PendingImplicitInstantiations.empty())) {
2697    PendingImplicitInstantiation Inst;
2698
2699    if (PendingLocalImplicitInstantiations.empty()) {
2700      Inst = PendingImplicitInstantiations.front();
2701      PendingImplicitInstantiations.pop_front();
2702    } else {
2703      Inst = PendingLocalImplicitInstantiations.front();
2704      PendingLocalImplicitInstantiations.pop_front();
2705    }
2706
2707    // Instantiate function definitions
2708    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2709      PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Function),
2710                                            Function->getLocation(), *this,
2711                                            Context.getSourceManager(),
2712                                           "instantiating function definition");
2713
2714      InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true);
2715      continue;
2716    }
2717
2718    // Instantiate static data member definitions.
2719    VarDecl *Var = cast<VarDecl>(Inst.first);
2720    assert(Var->isStaticDataMember() && "Not a static data member?");
2721
2722    // Don't try to instantiate declarations if the most recent redeclaration
2723    // is invalid.
2724    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2725      continue;
2726
2727    // Check if the most recent declaration has changed the specialization kind
2728    // and removed the need for implicit instantiation.
2729    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2730    case TSK_Undeclared:
2731      assert(false && "Cannot instantitiate an undeclared specialization.");
2732    case TSK_ExplicitInstantiationDeclaration:
2733    case TSK_ExplicitInstantiationDefinition:
2734    case TSK_ExplicitSpecialization:
2735      continue;  // No longer need implicit instantiation.
2736    case TSK_ImplicitInstantiation:
2737      break;
2738    }
2739
2740    PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Var),
2741                                          Var->getLocation(), *this,
2742                                          Context.getSourceManager(),
2743                                          "instantiating static data member "
2744                                          "definition");
2745
2746    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true);
2747  }
2748}
2749
2750void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2751                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2752  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2753         E = Pattern->ddiag_end(); I != E; ++I) {
2754    DependentDiagnostic *DD = *I;
2755
2756    switch (DD->getKind()) {
2757    case DependentDiagnostic::Access:
2758      HandleDependentAccessCheck(*DD, TemplateArgs);
2759      break;
2760    }
2761  }
2762}
2763