SemaTemplateInstantiateDecl.cpp revision 659107b190503e2588bec81f92af1d5f745f9580 
1//===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//===----------------------------------------------------------------------===/
8//
9//  This file implements C++ template instantiation for declarations.
10//
11//===----------------------------------------------------------------------===/
12#include "Sema.h"
13#include "Lookup.h"
14#include "clang/AST/ASTConsumer.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/DeclTemplate.h"
17#include "clang/AST/DeclVisitor.h"
18#include "clang/AST/DependentDiagnostic.h"
19#include "clang/AST/Expr.h"
20#include "clang/AST/ExprCXX.h"
21#include "clang/AST/TypeLoc.h"
22#include "clang/Basic/PrettyStackTrace.h"
23#include "clang/Lex/Preprocessor.h"
24
25using namespace clang;
26
27namespace {
28  class TemplateDeclInstantiator
29    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
30    Sema &SemaRef;
31    DeclContext *Owner;
32    const MultiLevelTemplateArgumentList &TemplateArgs;
33
34    void InstantiateAttrs(Decl *Tmpl, Decl *New);
35
36  public:
37    typedef Sema::OwningExprResult OwningExprResult;
38
39    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
40                             const MultiLevelTemplateArgumentList &TemplateArgs)
41      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
42
43    // FIXME: Once we get closer to completion, replace these manually-written
44    // declarations with automatically-generated ones from
45    // clang/AST/DeclNodes.def.
46    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
47    Decl *VisitNamespaceDecl(NamespaceDecl *D);
48    Decl *VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
49    Decl *VisitTypedefDecl(TypedefDecl *D);
50    Decl *VisitVarDecl(VarDecl *D);
51    Decl *VisitFieldDecl(FieldDecl *D);
52    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
53    Decl *VisitEnumDecl(EnumDecl *D);
54    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
55    Decl *VisitFriendDecl(FriendDecl *D);
56    Decl *VisitFunctionDecl(FunctionDecl *D,
57                            TemplateParameterList *TemplateParams = 0);
58    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
59    Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
60                             TemplateParameterList *TemplateParams = 0);
61    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
62    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
63    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
64    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
65    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
66    Decl *VisitClassTemplatePartialSpecializationDecl(
67                                    ClassTemplatePartialSpecializationDecl *D);
68    Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
69    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
70    Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
71    Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
72    Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
73    Decl *VisitUsingDecl(UsingDecl *D);
74    Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
75    Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
76    Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
77
78    // Base case. FIXME: Remove once we can instantiate everything.
79    Decl *VisitDecl(Decl *D) {
80      unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
81                                                            Diagnostic::Error,
82                                                   "cannot instantiate %0 yet");
83      SemaRef.Diag(D->getLocation(), DiagID)
84        << D->getDeclKindName();
85
86      return 0;
87    }
88
89    const LangOptions &getLangOptions() {
90      return SemaRef.getLangOptions();
91    }
92
93    // Helper functions for instantiating methods.
94    TypeSourceInfo *SubstFunctionType(FunctionDecl *D,
95                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
96    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
97    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
98
99    TemplateParameterList *
100      SubstTemplateParams(TemplateParameterList *List);
101
102    bool SubstQualifier(const DeclaratorDecl *OldDecl,
103                        DeclaratorDecl *NewDecl);
104    bool SubstQualifier(const TagDecl *OldDecl,
105                        TagDecl *NewDecl);
106
107    bool InstantiateClassTemplatePartialSpecialization(
108                                              ClassTemplateDecl *ClassTemplate,
109                           ClassTemplatePartialSpecializationDecl *PartialSpec);
110  };
111}
112
113bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
114                                              DeclaratorDecl *NewDecl) {
115  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
116  if (!OldQual) return false;
117
118  SourceRange QualRange = OldDecl->getQualifierRange();
119
120  NestedNameSpecifier *NewQual
121    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
122  if (!NewQual)
123    return true;
124
125  NewDecl->setQualifierInfo(NewQual, QualRange);
126  return false;
127}
128
129bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
130                                              TagDecl *NewDecl) {
131  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
132  if (!OldQual) return false;
133
134  SourceRange QualRange = OldDecl->getQualifierRange();
135
136  NestedNameSpecifier *NewQual
137    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
138  if (!NewQual)
139    return true;
140
141  NewDecl->setQualifierInfo(NewQual, QualRange);
142  return false;
143}
144
145// FIXME: Is this too simple?
146void TemplateDeclInstantiator::InstantiateAttrs(Decl *Tmpl, Decl *New) {
147  for (const Attr *TmplAttr = Tmpl->getAttrs(); TmplAttr;
148       TmplAttr = TmplAttr->getNext()) {
149
150    // FIXME: Is cloning correct for all attributes?
151    Attr *NewAttr = TmplAttr->clone(SemaRef.Context);
152
153    New->addAttr(NewAttr);
154  }
155}
156
157Decl *
158TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
159  assert(false && "Translation units cannot be instantiated");
160  return D;
161}
162
163Decl *
164TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
165  assert(false && "Namespaces cannot be instantiated");
166  return D;
167}
168
169Decl *
170TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
171  NamespaceAliasDecl *Inst
172    = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
173                                 D->getNamespaceLoc(),
174                                 D->getAliasLoc(),
175                                 D->getNamespace()->getIdentifier(),
176                                 D->getQualifierRange(),
177                                 D->getQualifier(),
178                                 D->getTargetNameLoc(),
179                                 D->getNamespace());
180  Owner->addDecl(Inst);
181  return Inst;
182}
183
184Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
185  bool Invalid = false;
186  TypeSourceInfo *DI = D->getTypeSourceInfo();
187  if (DI->getType()->isDependentType()) {
188    DI = SemaRef.SubstType(DI, TemplateArgs,
189                           D->getLocation(), D->getDeclName());
190    if (!DI) {
191      Invalid = true;
192      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
193    }
194  } else {
195    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
196  }
197
198  // Create the new typedef
199  TypedefDecl *Typedef
200    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
201                          D->getIdentifier(), DI);
202  if (Invalid)
203    Typedef->setInvalidDecl();
204
205  if (const TagType *TT = DI->getType()->getAs<TagType>()) {
206    TagDecl *TD = TT->getDecl();
207
208    // If the TagDecl that the TypedefDecl points to is an anonymous decl
209    // keep track of the TypedefDecl.
210    if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl())
211      TD->setTypedefForAnonDecl(Typedef);
212  }
213
214  if (TypedefDecl *Prev = D->getPreviousDeclaration()) {
215    NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
216                                                       TemplateArgs);
217    Typedef->setPreviousDeclaration(cast<TypedefDecl>(InstPrev));
218  }
219
220  InstantiateAttrs(D, Typedef);
221
222  Typedef->setAccess(D->getAccess());
223  Owner->addDecl(Typedef);
224
225  return Typedef;
226}
227
228/// \brief Instantiate the arguments provided as part of initialization.
229///
230/// \returns true if an error occurred, false otherwise.
231static bool InstantiateInitializationArguments(Sema &SemaRef,
232                                               Expr **Args, unsigned NumArgs,
233                           const MultiLevelTemplateArgumentList &TemplateArgs,
234                         llvm::SmallVectorImpl<SourceLocation> &FakeCommaLocs,
235                           ASTOwningVector<&ActionBase::DeleteExpr> &InitArgs) {
236  for (unsigned I = 0; I != NumArgs; ++I) {
237    // When we hit the first defaulted argument, break out of the loop:
238    // we don't pass those default arguments on.
239    if (Args[I]->isDefaultArgument())
240      break;
241
242    Sema::OwningExprResult Arg = SemaRef.SubstExpr(Args[I], TemplateArgs);
243    if (Arg.isInvalid())
244      return true;
245
246    Expr *ArgExpr = (Expr *)Arg.get();
247    InitArgs.push_back(Arg.release());
248
249    // FIXME: We're faking all of the comma locations. Do we need them?
250    FakeCommaLocs.push_back(
251                          SemaRef.PP.getLocForEndOfToken(ArgExpr->getLocEnd()));
252  }
253
254  return false;
255}
256
257/// \brief Instantiate an initializer, breaking it into separate
258/// initialization arguments.
259///
260/// \param S The semantic analysis object.
261///
262/// \param Init The initializer to instantiate.
263///
264/// \param TemplateArgs Template arguments to be substituted into the
265/// initializer.
266///
267/// \param NewArgs Will be filled in with the instantiation arguments.
268///
269/// \returns true if an error occurred, false otherwise
270static bool InstantiateInitializer(Sema &S, Expr *Init,
271                            const MultiLevelTemplateArgumentList &TemplateArgs,
272                                   SourceLocation &LParenLoc,
273                               llvm::SmallVector<SourceLocation, 4> &CommaLocs,
274                             ASTOwningVector<&ActionBase::DeleteExpr> &NewArgs,
275                                   SourceLocation &RParenLoc) {
276  NewArgs.clear();
277  LParenLoc = SourceLocation();
278  RParenLoc = SourceLocation();
279
280  if (!Init)
281    return false;
282
283  if (CXXExprWithTemporaries *ExprTemp = dyn_cast<CXXExprWithTemporaries>(Init))
284    Init = ExprTemp->getSubExpr();
285
286  while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init))
287    Init = Binder->getSubExpr();
288
289  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
290    Init = ICE->getSubExprAsWritten();
291
292  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
293    LParenLoc = ParenList->getLParenLoc();
294    RParenLoc = ParenList->getRParenLoc();
295    return InstantiateInitializationArguments(S, ParenList->getExprs(),
296                                              ParenList->getNumExprs(),
297                                              TemplateArgs, CommaLocs,
298                                              NewArgs);
299  }
300
301  if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) {
302    if (!isa<CXXTemporaryObjectExpr>(Construct)) {
303      if (InstantiateInitializationArguments(S,
304                                             Construct->getArgs(),
305                                             Construct->getNumArgs(),
306                                             TemplateArgs,
307                                             CommaLocs, NewArgs))
308        return true;
309
310      // FIXME: Fake locations!
311      LParenLoc = S.PP.getLocForEndOfToken(Init->getLocStart());
312      RParenLoc = CommaLocs.empty()? LParenLoc : CommaLocs.back();
313      return false;
314    }
315  }
316
317  Sema::OwningExprResult Result = S.SubstExpr(Init, TemplateArgs);
318  if (Result.isInvalid())
319    return true;
320
321  NewArgs.push_back(Result.takeAs<Expr>());
322  return false;
323}
324
325Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
326  // If this is the variable for an anonymous struct or union,
327  // instantiate the anonymous struct/union type first.
328  if (const RecordType *RecordTy = D->getType()->getAs<RecordType>())
329    if (RecordTy->getDecl()->isAnonymousStructOrUnion())
330      if (!VisitCXXRecordDecl(cast<CXXRecordDecl>(RecordTy->getDecl())))
331        return 0;
332
333  // Do substitution on the type of the declaration
334  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
335                                         TemplateArgs,
336                                         D->getTypeSpecStartLoc(),
337                                         D->getDeclName());
338  if (!DI)
339    return 0;
340
341  // Build the instantiated declaration
342  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
343                                 D->getLocation(), D->getIdentifier(),
344                                 DI->getType(), DI,
345                                 D->getStorageClass(),
346                                 D->getStorageClassAsWritten());
347  Var->setThreadSpecified(D->isThreadSpecified());
348  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
349  Var->setDeclaredInCondition(D->isDeclaredInCondition());
350
351  // Substitute the nested name specifier, if any.
352  if (SubstQualifier(D, Var))
353    return 0;
354
355  // If we are instantiating a static data member defined
356  // out-of-line, the instantiation will have the same lexical
357  // context (which will be a namespace scope) as the template.
358  if (D->isOutOfLine())
359    Var->setLexicalDeclContext(D->getLexicalDeclContext());
360
361  Var->setAccess(D->getAccess());
362  Var->setUsed(D->isUsed());
363
364  // FIXME: In theory, we could have a previous declaration for variables that
365  // are not static data members.
366  bool Redeclaration = false;
367  // FIXME: having to fake up a LookupResult is dumb.
368  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
369                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
370  if (D->isStaticDataMember())
371    SemaRef.LookupQualifiedName(Previous, Owner, false);
372  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
373
374  if (D->isOutOfLine()) {
375    D->getLexicalDeclContext()->addDecl(Var);
376    Owner->makeDeclVisibleInContext(Var);
377  } else {
378    Owner->addDecl(Var);
379
380    if (Owner->isFunctionOrMethod())
381      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Var);
382  }
383
384  // Link instantiations of static data members back to the template from
385  // which they were instantiated.
386  if (Var->isStaticDataMember())
387    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
388                                                     TSK_ImplicitInstantiation);
389
390  if (Var->getAnyInitializer()) {
391    // We already have an initializer in the class.
392  } else if (D->getInit()) {
393    if (Var->isStaticDataMember() && !D->isOutOfLine())
394      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
395    else
396      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
397
398    // Instantiate the initializer.
399    SourceLocation LParenLoc, RParenLoc;
400    llvm::SmallVector<SourceLocation, 4> CommaLocs;
401    ASTOwningVector<&ActionBase::DeleteExpr> InitArgs(SemaRef);
402    if (!InstantiateInitializer(SemaRef, D->getInit(), TemplateArgs, LParenLoc,
403                                CommaLocs, InitArgs, RParenLoc)) {
404      // Attach the initializer to the declaration.
405      if (D->hasCXXDirectInitializer()) {
406        // Add the direct initializer to the declaration.
407        SemaRef.AddCXXDirectInitializerToDecl(Sema::DeclPtrTy::make(Var),
408                                              LParenLoc,
409                                              move_arg(InitArgs),
410                                              CommaLocs.data(),
411                                              RParenLoc);
412      } else if (InitArgs.size() == 1) {
413        Expr *Init = (Expr*)(InitArgs.take()[0]);
414        SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var),
415                                     SemaRef.Owned(Init),
416                                     false);
417      } else {
418        assert(InitArgs.size() == 0);
419        SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
420      }
421    } else {
422      // FIXME: Not too happy about invalidating the declaration
423      // because of a bogus initializer.
424      Var->setInvalidDecl();
425    }
426
427    SemaRef.PopExpressionEvaluationContext();
428  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
429    SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
430
431  // Diagnose unused local variables.
432  if (!Var->isInvalidDecl() && Owner->isFunctionOrMethod() && !Var->isUsed())
433    SemaRef.DiagnoseUnusedDecl(Var);
434
435  return Var;
436}
437
438Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
439  bool Invalid = false;
440  TypeSourceInfo *DI = D->getTypeSourceInfo();
441  if (DI->getType()->isDependentType())  {
442    DI = SemaRef.SubstType(DI, TemplateArgs,
443                           D->getLocation(), D->getDeclName());
444    if (!DI) {
445      DI = D->getTypeSourceInfo();
446      Invalid = true;
447    } else if (DI->getType()->isFunctionType()) {
448      // C++ [temp.arg.type]p3:
449      //   If a declaration acquires a function type through a type
450      //   dependent on a template-parameter and this causes a
451      //   declaration that does not use the syntactic form of a
452      //   function declarator to have function type, the program is
453      //   ill-formed.
454      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
455        << DI->getType();
456      Invalid = true;
457    }
458  } else {
459    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
460  }
461
462  Expr *BitWidth = D->getBitWidth();
463  if (Invalid)
464    BitWidth = 0;
465  else if (BitWidth) {
466    // The bit-width expression is not potentially evaluated.
467    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
468
469    OwningExprResult InstantiatedBitWidth
470      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
471    if (InstantiatedBitWidth.isInvalid()) {
472      Invalid = true;
473      BitWidth = 0;
474    } else
475      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
476  }
477
478  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
479                                            DI->getType(), DI,
480                                            cast<RecordDecl>(Owner),
481                                            D->getLocation(),
482                                            D->isMutable(),
483                                            BitWidth,
484                                            D->getTypeSpecStartLoc(),
485                                            D->getAccess(),
486                                            0);
487  if (!Field) {
488    cast<Decl>(Owner)->setInvalidDecl();
489    return 0;
490  }
491
492  InstantiateAttrs(D, Field);
493
494  if (Invalid)
495    Field->setInvalidDecl();
496
497  if (!Field->getDeclName()) {
498    // Keep track of where this decl came from.
499    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
500  }
501  if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
502    if (Parent->isAnonymousStructOrUnion() &&
503        Parent->getLookupContext()->isFunctionOrMethod())
504      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
505  }
506
507  Field->setImplicit(D->isImplicit());
508  Field->setAccess(D->getAccess());
509  Owner->addDecl(Field);
510
511  return Field;
512}
513
514Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
515  // Handle friend type expressions by simply substituting template
516  // parameters into the pattern type and checking the result.
517  if (TypeSourceInfo *Ty = D->getFriendType()) {
518    TypeSourceInfo *InstTy =
519      SemaRef.SubstType(Ty, TemplateArgs,
520                        D->getLocation(), DeclarationName());
521    if (!InstTy)
522      return 0;
523
524    FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getFriendLoc(), InstTy);
525    if (!FD)
526      return 0;
527
528    FD->setAccess(AS_public);
529    Owner->addDecl(FD);
530    return FD;
531  }
532
533  NamedDecl *ND = D->getFriendDecl();
534  assert(ND && "friend decl must be a decl or a type!");
535
536  // All of the Visit implementations for the various potential friend
537  // declarations have to be carefully written to work for friend
538  // objects, with the most important detail being that the target
539  // decl should almost certainly not be placed in Owner.
540  Decl *NewND = Visit(ND);
541  if (!NewND) return 0;
542
543  FriendDecl *FD =
544    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
545                       cast<NamedDecl>(NewND), D->getFriendLoc());
546  FD->setAccess(AS_public);
547  Owner->addDecl(FD);
548  return FD;
549}
550
551Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
552  Expr *AssertExpr = D->getAssertExpr();
553
554  // The expression in a static assertion is not potentially evaluated.
555  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
556
557  OwningExprResult InstantiatedAssertExpr
558    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
559  if (InstantiatedAssertExpr.isInvalid())
560    return 0;
561
562  OwningExprResult Message(SemaRef, D->getMessage());
563  D->getMessage()->Retain();
564  Decl *StaticAssert
565    = SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
566                                           move(InstantiatedAssertExpr),
567                                           move(Message)).getAs<Decl>();
568  return StaticAssert;
569}
570
571Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
572  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
573                                    D->getLocation(), D->getIdentifier(),
574                                    D->getTagKeywordLoc(),
575                                    /*PrevDecl=*/0);
576  Enum->setInstantiationOfMemberEnum(D);
577  Enum->setAccess(D->getAccess());
578  if (SubstQualifier(D, Enum)) return 0;
579  Owner->addDecl(Enum);
580  Enum->startDefinition();
581
582  if (D->getDeclContext()->isFunctionOrMethod())
583    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
584
585  llvm::SmallVector<Sema::DeclPtrTy, 4> Enumerators;
586
587  EnumConstantDecl *LastEnumConst = 0;
588  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
589         ECEnd = D->enumerator_end();
590       EC != ECEnd; ++EC) {
591    // The specified value for the enumerator.
592    OwningExprResult Value = SemaRef.Owned((Expr *)0);
593    if (Expr *UninstValue = EC->getInitExpr()) {
594      // The enumerator's value expression is not potentially evaluated.
595      EnterExpressionEvaluationContext Unevaluated(SemaRef,
596                                                   Action::Unevaluated);
597
598      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
599    }
600
601    // Drop the initial value and continue.
602    bool isInvalid = false;
603    if (Value.isInvalid()) {
604      Value = SemaRef.Owned((Expr *)0);
605      isInvalid = true;
606    }
607
608    EnumConstantDecl *EnumConst
609      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
610                                  EC->getLocation(), EC->getIdentifier(),
611                                  move(Value));
612
613    if (isInvalid) {
614      if (EnumConst)
615        EnumConst->setInvalidDecl();
616      Enum->setInvalidDecl();
617    }
618
619    if (EnumConst) {
620      EnumConst->setAccess(Enum->getAccess());
621      Enum->addDecl(EnumConst);
622      Enumerators.push_back(Sema::DeclPtrTy::make(EnumConst));
623      LastEnumConst = EnumConst;
624
625      if (D->getDeclContext()->isFunctionOrMethod()) {
626        // If the enumeration is within a function or method, record the enum
627        // constant as a local.
628        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
629      }
630    }
631  }
632
633  // FIXME: Fixup LBraceLoc and RBraceLoc
634  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
635  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
636                        Sema::DeclPtrTy::make(Enum),
637                        &Enumerators[0], Enumerators.size(),
638                        0, 0);
639
640  return Enum;
641}
642
643Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
644  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
645  return 0;
646}
647
648Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
649  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
650
651  // Create a local instantiation scope for this class template, which
652  // will contain the instantiations of the template parameters.
653  Sema::LocalInstantiationScope Scope(SemaRef);
654  TemplateParameterList *TempParams = D->getTemplateParameters();
655  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
656  if (!InstParams)
657    return NULL;
658
659  CXXRecordDecl *Pattern = D->getTemplatedDecl();
660
661  // Instantiate the qualifier.  We have to do this first in case
662  // we're a friend declaration, because if we are then we need to put
663  // the new declaration in the appropriate context.
664  NestedNameSpecifier *Qualifier = Pattern->getQualifier();
665  if (Qualifier) {
666    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
667                                                 Pattern->getQualifierRange(),
668                                                 TemplateArgs);
669    if (!Qualifier) return 0;
670  }
671
672  CXXRecordDecl *PrevDecl = 0;
673  ClassTemplateDecl *PrevClassTemplate = 0;
674
675  // If this isn't a friend, then it's a member template, in which
676  // case we just want to build the instantiation in the
677  // specialization.  If it is a friend, we want to build it in
678  // the appropriate context.
679  DeclContext *DC = Owner;
680  if (isFriend) {
681    if (Qualifier) {
682      CXXScopeSpec SS;
683      SS.setScopeRep(Qualifier);
684      SS.setRange(Pattern->getQualifierRange());
685      DC = SemaRef.computeDeclContext(SS);
686      if (!DC) return 0;
687    } else {
688      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
689                                           Pattern->getDeclContext(),
690                                           TemplateArgs);
691    }
692
693    // Look for a previous declaration of the template in the owning
694    // context.
695    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
696                   Sema::LookupOrdinaryName, Sema::ForRedeclaration);
697    SemaRef.LookupQualifiedName(R, DC);
698
699    if (R.isSingleResult()) {
700      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
701      if (PrevClassTemplate)
702        PrevDecl = PrevClassTemplate->getTemplatedDecl();
703    }
704
705    if (!PrevClassTemplate && Qualifier) {
706      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
707        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
708        << Pattern->getQualifierRange();
709      return 0;
710    }
711
712    bool AdoptedPreviousTemplateParams = false;
713    if (PrevClassTemplate) {
714      bool Complain = true;
715
716      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
717      // template for struct std::tr1::__detail::_Map_base, where the
718      // template parameters of the friend declaration don't match the
719      // template parameters of the original declaration. In this one
720      // case, we don't complain about the ill-formed friend
721      // declaration.
722      if (isFriend && Pattern->getIdentifier() &&
723          Pattern->getIdentifier()->isStr("_Map_base") &&
724          DC->isNamespace() &&
725          cast<NamespaceDecl>(DC)->getIdentifier() &&
726          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
727        DeclContext *DCParent = DC->getParent();
728        if (DCParent->isNamespace() &&
729            cast<NamespaceDecl>(DCParent)->getIdentifier() &&
730            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
731          DeclContext *DCParent2 = DCParent->getParent();
732          if (DCParent2->isNamespace() &&
733              cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
734              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
735              DCParent2->getParent()->isTranslationUnit())
736            Complain = false;
737        }
738      }
739
740      TemplateParameterList *PrevParams
741        = PrevClassTemplate->getTemplateParameters();
742
743      // Make sure the parameter lists match.
744      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
745                                                  Complain,
746                                                  Sema::TPL_TemplateMatch)) {
747        if (Complain)
748          return 0;
749
750        AdoptedPreviousTemplateParams = true;
751        InstParams = PrevParams;
752      }
753
754      // Do some additional validation, then merge default arguments
755      // from the existing declarations.
756      if (!AdoptedPreviousTemplateParams &&
757          SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
758                                             Sema::TPC_ClassTemplate))
759        return 0;
760    }
761  }
762
763  CXXRecordDecl *RecordInst
764    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
765                            Pattern->getLocation(), Pattern->getIdentifier(),
766                            Pattern->getTagKeywordLoc(), PrevDecl,
767                            /*DelayTypeCreation=*/true);
768
769  if (Qualifier)
770    RecordInst->setQualifierInfo(Qualifier, Pattern->getQualifierRange());
771
772  ClassTemplateDecl *Inst
773    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
774                                D->getIdentifier(), InstParams, RecordInst,
775                                PrevClassTemplate);
776  RecordInst->setDescribedClassTemplate(Inst);
777
778  if (isFriend) {
779    if (PrevClassTemplate)
780      Inst->setAccess(PrevClassTemplate->getAccess());
781    else
782      Inst->setAccess(D->getAccess());
783
784    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
785    // TODO: do we want to track the instantiation progeny of this
786    // friend target decl?
787  } else {
788    Inst->setAccess(D->getAccess());
789    Inst->setInstantiatedFromMemberTemplate(D);
790  }
791
792  // Trigger creation of the type for the instantiation.
793  SemaRef.Context.getInjectedClassNameType(RecordInst,
794                  Inst->getInjectedClassNameSpecialization(SemaRef.Context));
795
796  // Finish handling of friends.
797  if (isFriend) {
798    DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
799    return Inst;
800  }
801
802  Owner->addDecl(Inst);
803
804  // Instantiate all of the partial specializations of this member class
805  // template.
806  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
807  D->getPartialSpecializations(PartialSpecs);
808  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
809    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
810
811  return Inst;
812}
813
814Decl *
815TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
816                                   ClassTemplatePartialSpecializationDecl *D) {
817  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
818
819  // Lookup the already-instantiated declaration in the instantiation
820  // of the class template and return that.
821  DeclContext::lookup_result Found
822    = Owner->lookup(ClassTemplate->getDeclName());
823  if (Found.first == Found.second)
824    return 0;
825
826  ClassTemplateDecl *InstClassTemplate
827    = dyn_cast<ClassTemplateDecl>(*Found.first);
828  if (!InstClassTemplate)
829    return 0;
830
831  Decl *DCanon = D->getCanonicalDecl();
832  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
833            P = InstClassTemplate->getPartialSpecializations().begin(),
834         PEnd = InstClassTemplate->getPartialSpecializations().end();
835       P != PEnd; ++P) {
836    if (P->getInstantiatedFromMember()->getCanonicalDecl() == DCanon)
837      return &*P;
838  }
839
840  return 0;
841}
842
843Decl *
844TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
845  // Create a local instantiation scope for this function template, which
846  // will contain the instantiations of the template parameters and then get
847  // merged with the local instantiation scope for the function template
848  // itself.
849  Sema::LocalInstantiationScope Scope(SemaRef);
850
851  TemplateParameterList *TempParams = D->getTemplateParameters();
852  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
853  if (!InstParams)
854    return NULL;
855
856  FunctionDecl *Instantiated = 0;
857  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
858    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
859                                                                 InstParams));
860  else
861    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
862                                                          D->getTemplatedDecl(),
863                                                                InstParams));
864
865  if (!Instantiated)
866    return 0;
867
868  Instantiated->setAccess(D->getAccess());
869
870  // Link the instantiated function template declaration to the function
871  // template from which it was instantiated.
872  FunctionTemplateDecl *InstTemplate
873    = Instantiated->getDescribedFunctionTemplate();
874  InstTemplate->setAccess(D->getAccess());
875  assert(InstTemplate &&
876         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
877
878  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
879
880  // Link the instantiation back to the pattern *unless* this is a
881  // non-definition friend declaration.
882  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
883      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
884    InstTemplate->setInstantiatedFromMemberTemplate(D);
885
886  // Make declarations visible in the appropriate context.
887  if (!isFriend)
888    Owner->addDecl(InstTemplate);
889
890  return InstTemplate;
891}
892
893Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
894  CXXRecordDecl *PrevDecl = 0;
895  if (D->isInjectedClassName())
896    PrevDecl = cast<CXXRecordDecl>(Owner);
897  else if (D->getPreviousDeclaration()) {
898    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
899                                                   D->getPreviousDeclaration(),
900                                                   TemplateArgs);
901    if (!Prev) return 0;
902    PrevDecl = cast<CXXRecordDecl>(Prev);
903  }
904
905  CXXRecordDecl *Record
906    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
907                            D->getLocation(), D->getIdentifier(),
908                            D->getTagKeywordLoc(), PrevDecl);
909
910  // Substitute the nested name specifier, if any.
911  if (SubstQualifier(D, Record))
912    return 0;
913
914  Record->setImplicit(D->isImplicit());
915  // FIXME: Check against AS_none is an ugly hack to work around the issue that
916  // the tag decls introduced by friend class declarations don't have an access
917  // specifier. Remove once this area of the code gets sorted out.
918  if (D->getAccess() != AS_none)
919    Record->setAccess(D->getAccess());
920  if (!D->isInjectedClassName())
921    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
922
923  // If the original function was part of a friend declaration,
924  // inherit its namespace state.
925  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
926    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
927
928  // Make sure that anonymous structs and unions are recorded.
929  if (D->isAnonymousStructOrUnion()) {
930    Record->setAnonymousStructOrUnion(true);
931    if (Record->getDeclContext()->getLookupContext()->isFunctionOrMethod())
932      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
933  }
934
935  Owner->addDecl(Record);
936  return Record;
937}
938
939/// Normal class members are of more specific types and therefore
940/// don't make it here.  This function serves two purposes:
941///   1) instantiating function templates
942///   2) substituting friend declarations
943/// FIXME: preserve function definitions in case #2
944Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
945                                       TemplateParameterList *TemplateParams) {
946  // Check whether there is already a function template specialization for
947  // this declaration.
948  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
949  void *InsertPos = 0;
950  if (FunctionTemplate && !TemplateParams) {
951    llvm::FoldingSetNodeID ID;
952    FunctionTemplateSpecializationInfo::Profile(ID,
953                             TemplateArgs.getInnermost().getFlatArgumentList(),
954                                       TemplateArgs.getInnermost().flat_size(),
955                                                SemaRef.Context);
956
957    FunctionTemplateSpecializationInfo *Info
958      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
959                                                                   InsertPos);
960
961    // If we already have a function template specialization, return it.
962    if (Info)
963      return Info->Function;
964  }
965
966  bool isFriend;
967  if (FunctionTemplate)
968    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
969  else
970    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
971
972  bool MergeWithParentScope = (TemplateParams != 0) ||
973    !(isa<Decl>(Owner) &&
974      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
975  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
976
977  llvm::SmallVector<ParmVarDecl *, 4> Params;
978  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
979  TInfo = SubstFunctionType(D, Params);
980  if (!TInfo)
981    return 0;
982  QualType T = TInfo->getType();
983
984  NestedNameSpecifier *Qualifier = D->getQualifier();
985  if (Qualifier) {
986    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
987                                                 D->getQualifierRange(),
988                                                 TemplateArgs);
989    if (!Qualifier) return 0;
990  }
991
992  // If we're instantiating a local function declaration, put the result
993  // in the owner;  otherwise we need to find the instantiated context.
994  DeclContext *DC;
995  if (D->getDeclContext()->isFunctionOrMethod())
996    DC = Owner;
997  else if (isFriend && Qualifier) {
998    CXXScopeSpec SS;
999    SS.setScopeRep(Qualifier);
1000    SS.setRange(D->getQualifierRange());
1001    DC = SemaRef.computeDeclContext(SS);
1002    if (!DC) return 0;
1003  } else {
1004    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1005                                         TemplateArgs);
1006  }
1007
1008  FunctionDecl *Function =
1009      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
1010                           D->getDeclName(), T, TInfo,
1011                           D->getStorageClass(), D->getStorageClassAsWritten(),
1012                           D->isInlineSpecified(), D->hasWrittenPrototype());
1013
1014  if (Qualifier)
1015    Function->setQualifierInfo(Qualifier, D->getQualifierRange());
1016
1017  DeclContext *LexicalDC = Owner;
1018  if (!isFriend && D->isOutOfLine()) {
1019    assert(D->getDeclContext()->isFileContext());
1020    LexicalDC = D->getDeclContext();
1021  }
1022
1023  Function->setLexicalDeclContext(LexicalDC);
1024
1025  // Attach the parameters
1026  for (unsigned P = 0; P < Params.size(); ++P)
1027    Params[P]->setOwningFunction(Function);
1028  Function->setParams(Params.data(), Params.size());
1029
1030  SourceLocation InstantiateAtPOI;
1031  if (TemplateParams) {
1032    // Our resulting instantiation is actually a function template, since we
1033    // are substituting only the outer template parameters. For example, given
1034    //
1035    //   template<typename T>
1036    //   struct X {
1037    //     template<typename U> friend void f(T, U);
1038    //   };
1039    //
1040    //   X<int> x;
1041    //
1042    // We are instantiating the friend function template "f" within X<int>,
1043    // which means substituting int for T, but leaving "f" as a friend function
1044    // template.
1045    // Build the function template itself.
1046    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1047                                                    Function->getLocation(),
1048                                                    Function->getDeclName(),
1049                                                    TemplateParams, Function);
1050    Function->setDescribedFunctionTemplate(FunctionTemplate);
1051
1052    FunctionTemplate->setLexicalDeclContext(LexicalDC);
1053
1054    if (isFriend && D->isThisDeclarationADefinition()) {
1055      // TODO: should we remember this connection regardless of whether
1056      // the friend declaration provided a body?
1057      FunctionTemplate->setInstantiatedFromMemberTemplate(
1058                                           D->getDescribedFunctionTemplate());
1059    }
1060  } else if (FunctionTemplate) {
1061    // Record this function template specialization.
1062    Function->setFunctionTemplateSpecialization(FunctionTemplate,
1063                                                &TemplateArgs.getInnermost(),
1064                                                InsertPos);
1065  } else if (isFriend && D->isThisDeclarationADefinition()) {
1066    // TODO: should we remember this connection regardless of whether
1067    // the friend declaration provided a body?
1068    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1069  }
1070
1071  if (InitFunctionInstantiation(Function, D))
1072    Function->setInvalidDecl();
1073
1074  bool Redeclaration = false;
1075  bool OverloadableAttrRequired = false;
1076  bool isExplicitSpecialization = false;
1077
1078  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1079                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1080
1081  if (DependentFunctionTemplateSpecializationInfo *Info
1082        = D->getDependentSpecializationInfo()) {
1083    assert(isFriend && "non-friend has dependent specialization info?");
1084
1085    // This needs to be set now for future sanity.
1086    Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1087
1088    // Instantiate the explicit template arguments.
1089    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1090                                          Info->getRAngleLoc());
1091    for (unsigned I = 0, E = Info->getNumTemplateArgs(); I != E; ++I) {
1092      TemplateArgumentLoc Loc;
1093      if (SemaRef.Subst(Info->getTemplateArg(I), Loc, TemplateArgs))
1094        return 0;
1095
1096      ExplicitArgs.addArgument(Loc);
1097    }
1098
1099    // Map the candidate templates to their instantiations.
1100    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1101      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1102                                                Info->getTemplate(I),
1103                                                TemplateArgs);
1104      if (!Temp) return 0;
1105
1106      Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1107    }
1108
1109    if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1110                                                    &ExplicitArgs,
1111                                                    Previous))
1112      Function->setInvalidDecl();
1113
1114    isExplicitSpecialization = true;
1115
1116  } else if (TemplateParams || !FunctionTemplate) {
1117    // Look only into the namespace where the friend would be declared to
1118    // find a previous declaration. This is the innermost enclosing namespace,
1119    // as described in ActOnFriendFunctionDecl.
1120    SemaRef.LookupQualifiedName(Previous, DC);
1121
1122    // In C++, the previous declaration we find might be a tag type
1123    // (class or enum). In this case, the new declaration will hide the
1124    // tag type. Note that this does does not apply if we're declaring a
1125    // typedef (C++ [dcl.typedef]p4).
1126    if (Previous.isSingleTagDecl())
1127      Previous.clear();
1128  }
1129
1130  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1131                                   isExplicitSpecialization, Redeclaration,
1132                                   /*FIXME:*/OverloadableAttrRequired);
1133
1134  NamedDecl *PrincipalDecl = (TemplateParams
1135                              ? cast<NamedDecl>(FunctionTemplate)
1136                              : Function);
1137
1138  // If the original function was part of a friend declaration,
1139  // inherit its namespace state and add it to the owner.
1140  if (isFriend) {
1141    NamedDecl *PrevDecl;
1142    if (TemplateParams)
1143      PrevDecl = FunctionTemplate->getPreviousDeclaration();
1144    else
1145      PrevDecl = Function->getPreviousDeclaration();
1146
1147    PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0);
1148    DC->makeDeclVisibleInContext(PrincipalDecl, /*Recoverable=*/ false);
1149
1150    if (!SemaRef.getLangOptions().CPlusPlus0x &&
1151        D->isThisDeclarationADefinition()) {
1152      // Check for a function body.
1153      const FunctionDecl *Definition = 0;
1154      if (Function->getBody(Definition) &&
1155          Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1156        SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1157          << Function->getDeclName();
1158        SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1159        Function->setInvalidDecl();
1160      }
1161      // Check for redefinitions due to other instantiations of this or
1162      // a similar friend function.
1163      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1164                                           REnd = Function->redecls_end();
1165                R != REnd; ++R) {
1166        if (*R != Function &&
1167            ((*R)->getFriendObjectKind() != Decl::FOK_None)) {
1168          if (const FunctionDecl *RPattern
1169              = (*R)->getTemplateInstantiationPattern())
1170            if (RPattern->getBody(RPattern)) {
1171              SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1172                << Function->getDeclName();
1173              SemaRef.Diag((*R)->getLocation(), diag::note_previous_definition);
1174              Function->setInvalidDecl();
1175              break;
1176            }
1177        }
1178      }
1179    }
1180
1181  }
1182
1183  if (Function->isOverloadedOperator() && !DC->isRecord() &&
1184      PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1185    PrincipalDecl->setNonMemberOperator();
1186
1187  return Function;
1188}
1189
1190Decl *
1191TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1192                                      TemplateParameterList *TemplateParams) {
1193  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1194  void *InsertPos = 0;
1195  if (FunctionTemplate && !TemplateParams) {
1196    // We are creating a function template specialization from a function
1197    // template. Check whether there is already a function template
1198    // specialization for this particular set of template arguments.
1199    llvm::FoldingSetNodeID ID;
1200    FunctionTemplateSpecializationInfo::Profile(ID,
1201                            TemplateArgs.getInnermost().getFlatArgumentList(),
1202                                      TemplateArgs.getInnermost().flat_size(),
1203                                                SemaRef.Context);
1204
1205    FunctionTemplateSpecializationInfo *Info
1206      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
1207                                                                   InsertPos);
1208
1209    // If we already have a function template specialization, return it.
1210    if (Info)
1211      return Info->Function;
1212  }
1213
1214  bool isFriend;
1215  if (FunctionTemplate)
1216    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1217  else
1218    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1219
1220  bool MergeWithParentScope = (TemplateParams != 0) ||
1221    !(isa<Decl>(Owner) &&
1222      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1223  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1224
1225  llvm::SmallVector<ParmVarDecl *, 4> Params;
1226  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1227  TInfo = SubstFunctionType(D, Params);
1228  if (!TInfo)
1229    return 0;
1230  QualType T = TInfo->getType();
1231
1232  // \brief If the type of this function is not *directly* a function
1233  // type, then we're instantiating the a function that was declared
1234  // via a typedef, e.g.,
1235  //
1236  //   typedef int functype(int, int);
1237  //   functype func;
1238  //
1239  // In this case, we'll just go instantiate the ParmVarDecls that we
1240  // synthesized in the method declaration.
1241  if (!isa<FunctionProtoType>(T)) {
1242    assert(!Params.size() && "Instantiating type could not yield parameters");
1243    for (unsigned I = 0, N = D->getNumParams(); I != N; ++I) {
1244      ParmVarDecl *P = SemaRef.SubstParmVarDecl(D->getParamDecl(I),
1245                                                TemplateArgs);
1246      if (!P)
1247        return 0;
1248
1249      Params.push_back(P);
1250    }
1251  }
1252
1253  NestedNameSpecifier *Qualifier = D->getQualifier();
1254  if (Qualifier) {
1255    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1256                                                 D->getQualifierRange(),
1257                                                 TemplateArgs);
1258    if (!Qualifier) return 0;
1259  }
1260
1261  DeclContext *DC = Owner;
1262  if (isFriend) {
1263    if (Qualifier) {
1264      CXXScopeSpec SS;
1265      SS.setScopeRep(Qualifier);
1266      SS.setRange(D->getQualifierRange());
1267      DC = SemaRef.computeDeclContext(SS);
1268    } else {
1269      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1270                                           D->getDeclContext(),
1271                                           TemplateArgs);
1272    }
1273    if (!DC) return 0;
1274  }
1275
1276  // Build the instantiated method declaration.
1277  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1278  CXXMethodDecl *Method = 0;
1279
1280  DeclarationName Name = D->getDeclName();
1281  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1282    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1283    Name = SemaRef.Context.DeclarationNames.getCXXConstructorName(
1284                                    SemaRef.Context.getCanonicalType(ClassTy));
1285    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1286                                        Constructor->getLocation(),
1287                                        Name, T, TInfo,
1288                                        Constructor->isExplicit(),
1289                                        Constructor->isInlineSpecified(),
1290                                        false);
1291  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1292    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1293    Name = SemaRef.Context.DeclarationNames.getCXXDestructorName(
1294                                   SemaRef.Context.getCanonicalType(ClassTy));
1295    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1296                                       Destructor->getLocation(), Name,
1297                                       T, Destructor->isInlineSpecified(),
1298                                       false);
1299  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1300    CanQualType ConvTy
1301      = SemaRef.Context.getCanonicalType(
1302                                      T->getAs<FunctionType>()->getResultType());
1303    Name = SemaRef.Context.DeclarationNames.getCXXConversionFunctionName(
1304                                                                      ConvTy);
1305    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1306                                       Conversion->getLocation(), Name,
1307                                       T, TInfo,
1308                                       Conversion->isInlineSpecified(),
1309                                       Conversion->isExplicit());
1310  } else {
1311    Method = CXXMethodDecl::Create(SemaRef.Context, Record, D->getLocation(),
1312                                   D->getDeclName(), T, TInfo,
1313                                   D->isStatic(),
1314                                   D->getStorageClassAsWritten(),
1315                                   D->isInlineSpecified());
1316  }
1317
1318  if (Qualifier)
1319    Method->setQualifierInfo(Qualifier, D->getQualifierRange());
1320
1321  if (TemplateParams) {
1322    // Our resulting instantiation is actually a function template, since we
1323    // are substituting only the outer template parameters. For example, given
1324    //
1325    //   template<typename T>
1326    //   struct X {
1327    //     template<typename U> void f(T, U);
1328    //   };
1329    //
1330    //   X<int> x;
1331    //
1332    // We are instantiating the member template "f" within X<int>, which means
1333    // substituting int for T, but leaving "f" as a member function template.
1334    // Build the function template itself.
1335    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1336                                                    Method->getLocation(),
1337                                                    Method->getDeclName(),
1338                                                    TemplateParams, Method);
1339    if (isFriend) {
1340      FunctionTemplate->setLexicalDeclContext(Owner);
1341      FunctionTemplate->setObjectOfFriendDecl(true);
1342    } else if (D->isOutOfLine())
1343      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1344    Method->setDescribedFunctionTemplate(FunctionTemplate);
1345  } else if (FunctionTemplate) {
1346    // Record this function template specialization.
1347    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1348                                              &TemplateArgs.getInnermost(),
1349                                              InsertPos);
1350  } else if (!isFriend) {
1351    // Record that this is an instantiation of a member function.
1352    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1353  }
1354
1355  // If we are instantiating a member function defined
1356  // out-of-line, the instantiation will have the same lexical
1357  // context (which will be a namespace scope) as the template.
1358  if (isFriend) {
1359    Method->setLexicalDeclContext(Owner);
1360    Method->setObjectOfFriendDecl(true);
1361  } else if (D->isOutOfLine())
1362    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1363
1364  // Attach the parameters
1365  for (unsigned P = 0; P < Params.size(); ++P)
1366    Params[P]->setOwningFunction(Method);
1367  Method->setParams(Params.data(), Params.size());
1368
1369  if (InitMethodInstantiation(Method, D))
1370    Method->setInvalidDecl();
1371
1372  LookupResult Previous(SemaRef, Name, SourceLocation(),
1373                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1374
1375  if (!FunctionTemplate || TemplateParams || isFriend) {
1376    SemaRef.LookupQualifiedName(Previous, Record);
1377
1378    // In C++, the previous declaration we find might be a tag type
1379    // (class or enum). In this case, the new declaration will hide the
1380    // tag type. Note that this does does not apply if we're declaring a
1381    // typedef (C++ [dcl.typedef]p4).
1382    if (Previous.isSingleTagDecl())
1383      Previous.clear();
1384  }
1385
1386  bool Redeclaration = false;
1387  bool OverloadableAttrRequired = false;
1388  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1389                                   /*FIXME:*/OverloadableAttrRequired);
1390
1391  if (D->isPure())
1392    SemaRef.CheckPureMethod(Method, SourceRange());
1393
1394  Method->setAccess(D->getAccess());
1395
1396  if (FunctionTemplate) {
1397    // If there's a function template, let our caller handle it.
1398  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1399    // Don't hide a (potentially) valid declaration with an invalid one.
1400  } else {
1401    NamedDecl *DeclToAdd = (TemplateParams
1402                            ? cast<NamedDecl>(FunctionTemplate)
1403                            : Method);
1404    if (isFriend)
1405      Record->makeDeclVisibleInContext(DeclToAdd);
1406    else
1407      Owner->addDecl(DeclToAdd);
1408  }
1409
1410  return Method;
1411}
1412
1413Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1414  return VisitCXXMethodDecl(D);
1415}
1416
1417Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1418  return VisitCXXMethodDecl(D);
1419}
1420
1421Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1422  return VisitCXXMethodDecl(D);
1423}
1424
1425ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1426  return SemaRef.SubstParmVarDecl(D, TemplateArgs);
1427}
1428
1429Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1430                                                    TemplateTypeParmDecl *D) {
1431  // TODO: don't always clone when decls are refcounted.
1432  const Type* T = D->getTypeForDecl();
1433  assert(T->isTemplateTypeParmType());
1434  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1435
1436  TemplateTypeParmDecl *Inst =
1437    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1438                                 TTPT->getDepth() - 1, TTPT->getIndex(),
1439                                 TTPT->getName(),
1440                                 D->wasDeclaredWithTypename(),
1441                                 D->isParameterPack());
1442
1443  if (D->hasDefaultArgument())
1444    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1445
1446  // Introduce this template parameter's instantiation into the instantiation
1447  // scope.
1448  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1449
1450  return Inst;
1451}
1452
1453Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1454                                                 NonTypeTemplateParmDecl *D) {
1455  // Substitute into the type of the non-type template parameter.
1456  QualType T;
1457  TypeSourceInfo *DI = D->getTypeSourceInfo();
1458  if (DI) {
1459    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1460                           D->getDeclName());
1461    if (DI) T = DI->getType();
1462  } else {
1463    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1464                          D->getDeclName());
1465    DI = 0;
1466  }
1467  if (T.isNull())
1468    return 0;
1469
1470  // Check that this type is acceptable for a non-type template parameter.
1471  bool Invalid = false;
1472  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1473  if (T.isNull()) {
1474    T = SemaRef.Context.IntTy;
1475    Invalid = true;
1476  }
1477
1478  NonTypeTemplateParmDecl *Param
1479    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1480                                      D->getDepth() - 1, D->getPosition(),
1481                                      D->getIdentifier(), T, DI);
1482  if (Invalid)
1483    Param->setInvalidDecl();
1484
1485  Param->setDefaultArgument(D->getDefaultArgument());
1486
1487  // Introduce this template parameter's instantiation into the instantiation
1488  // scope.
1489  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1490  return Param;
1491}
1492
1493Decl *
1494TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1495                                                  TemplateTemplateParmDecl *D) {
1496  // Instantiate the template parameter list of the template template parameter.
1497  TemplateParameterList *TempParams = D->getTemplateParameters();
1498  TemplateParameterList *InstParams;
1499  {
1500    // Perform the actual substitution of template parameters within a new,
1501    // local instantiation scope.
1502    Sema::LocalInstantiationScope Scope(SemaRef);
1503    InstParams = SubstTemplateParams(TempParams);
1504    if (!InstParams)
1505      return NULL;
1506  }
1507
1508  // Build the template template parameter.
1509  TemplateTemplateParmDecl *Param
1510    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1511                                       D->getDepth() - 1, D->getPosition(),
1512                                       D->getIdentifier(), InstParams);
1513  Param->setDefaultArgument(D->getDefaultArgument());
1514
1515  // Introduce this template parameter's instantiation into the instantiation
1516  // scope.
1517  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1518
1519  return Param;
1520}
1521
1522Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1523  // Using directives are never dependent, so they require no explicit
1524
1525  UsingDirectiveDecl *Inst
1526    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1527                                 D->getNamespaceKeyLocation(),
1528                                 D->getQualifierRange(), D->getQualifier(),
1529                                 D->getIdentLocation(),
1530                                 D->getNominatedNamespace(),
1531                                 D->getCommonAncestor());
1532  Owner->addDecl(Inst);
1533  return Inst;
1534}
1535
1536Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1537  // The nested name specifier is non-dependent, so no transformation
1538  // is required.
1539
1540  // We only need to do redeclaration lookups if we're in a class
1541  // scope (in fact, it's not really even possible in non-class
1542  // scopes).
1543  bool CheckRedeclaration = Owner->isRecord();
1544
1545  LookupResult Prev(SemaRef, D->getDeclName(), D->getLocation(),
1546                    Sema::LookupUsingDeclName, Sema::ForRedeclaration);
1547
1548  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1549                                       D->getLocation(),
1550                                       D->getNestedNameRange(),
1551                                       D->getUsingLocation(),
1552                                       D->getTargetNestedNameDecl(),
1553                                       D->getDeclName(),
1554                                       D->isTypeName());
1555
1556  CXXScopeSpec SS;
1557  SS.setScopeRep(D->getTargetNestedNameDecl());
1558  SS.setRange(D->getNestedNameRange());
1559
1560  if (CheckRedeclaration) {
1561    Prev.setHideTags(false);
1562    SemaRef.LookupQualifiedName(Prev, Owner);
1563
1564    // Check for invalid redeclarations.
1565    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1566                                            D->isTypeName(), SS,
1567                                            D->getLocation(), Prev))
1568      NewUD->setInvalidDecl();
1569
1570  }
1571
1572  if (!NewUD->isInvalidDecl() &&
1573      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1574                                      D->getLocation()))
1575    NewUD->setInvalidDecl();
1576
1577  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1578  NewUD->setAccess(D->getAccess());
1579  Owner->addDecl(NewUD);
1580
1581  // Don't process the shadow decls for an invalid decl.
1582  if (NewUD->isInvalidDecl())
1583    return NewUD;
1584
1585  bool isFunctionScope = Owner->isFunctionOrMethod();
1586
1587  // Process the shadow decls.
1588  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1589         I != E; ++I) {
1590    UsingShadowDecl *Shadow = *I;
1591    NamedDecl *InstTarget =
1592      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1593                                                   Shadow->getTargetDecl(),
1594                                                   TemplateArgs));
1595
1596    if (CheckRedeclaration &&
1597        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1598      continue;
1599
1600    UsingShadowDecl *InstShadow
1601      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1602    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1603
1604    if (isFunctionScope)
1605      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1606  }
1607
1608  return NewUD;
1609}
1610
1611Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1612  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1613  return 0;
1614}
1615
1616Decl * TemplateDeclInstantiator
1617    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1618  NestedNameSpecifier *NNS =
1619    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1620                                     D->getTargetNestedNameRange(),
1621                                     TemplateArgs);
1622  if (!NNS)
1623    return 0;
1624
1625  CXXScopeSpec SS;
1626  SS.setRange(D->getTargetNestedNameRange());
1627  SS.setScopeRep(NNS);
1628
1629  NamedDecl *UD =
1630    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1631                                  D->getUsingLoc(), SS, D->getLocation(),
1632                                  D->getDeclName(), 0,
1633                                  /*instantiation*/ true,
1634                                  /*typename*/ true, D->getTypenameLoc());
1635  if (UD)
1636    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1637
1638  return UD;
1639}
1640
1641Decl * TemplateDeclInstantiator
1642    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1643  NestedNameSpecifier *NNS =
1644    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1645                                     D->getTargetNestedNameRange(),
1646                                     TemplateArgs);
1647  if (!NNS)
1648    return 0;
1649
1650  CXXScopeSpec SS;
1651  SS.setRange(D->getTargetNestedNameRange());
1652  SS.setScopeRep(NNS);
1653
1654  NamedDecl *UD =
1655    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1656                                  D->getUsingLoc(), SS, D->getLocation(),
1657                                  D->getDeclName(), 0,
1658                                  /*instantiation*/ true,
1659                                  /*typename*/ false, SourceLocation());
1660  if (UD)
1661    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1662
1663  return UD;
1664}
1665
1666Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1667                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1668  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1669  if (D->isInvalidDecl())
1670    return 0;
1671
1672  return Instantiator.Visit(D);
1673}
1674
1675/// \brief Instantiates a nested template parameter list in the current
1676/// instantiation context.
1677///
1678/// \param L The parameter list to instantiate
1679///
1680/// \returns NULL if there was an error
1681TemplateParameterList *
1682TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1683  // Get errors for all the parameters before bailing out.
1684  bool Invalid = false;
1685
1686  unsigned N = L->size();
1687  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1688  ParamVector Params;
1689  Params.reserve(N);
1690  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1691       PI != PE; ++PI) {
1692    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1693    Params.push_back(D);
1694    Invalid = Invalid || !D || D->isInvalidDecl();
1695  }
1696
1697  // Clean up if we had an error.
1698  if (Invalid) {
1699    for (ParamVector::iterator PI = Params.begin(), PE = Params.end();
1700         PI != PE; ++PI)
1701      if (*PI)
1702        (*PI)->Destroy(SemaRef.Context);
1703    return NULL;
1704  }
1705
1706  TemplateParameterList *InstL
1707    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1708                                    L->getLAngleLoc(), &Params.front(), N,
1709                                    L->getRAngleLoc());
1710  return InstL;
1711}
1712
1713/// \brief Instantiate the declaration of a class template partial
1714/// specialization.
1715///
1716/// \param ClassTemplate the (instantiated) class template that is partially
1717// specialized by the instantiation of \p PartialSpec.
1718///
1719/// \param PartialSpec the (uninstantiated) class template partial
1720/// specialization that we are instantiating.
1721///
1722/// \returns true if there was an error, false otherwise.
1723bool
1724TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1725                                            ClassTemplateDecl *ClassTemplate,
1726                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1727  // Create a local instantiation scope for this class template partial
1728  // specialization, which will contain the instantiations of the template
1729  // parameters.
1730  Sema::LocalInstantiationScope Scope(SemaRef);
1731
1732  // Substitute into the template parameters of the class template partial
1733  // specialization.
1734  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1735  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1736  if (!InstParams)
1737    return true;
1738
1739  // Substitute into the template arguments of the class template partial
1740  // specialization.
1741  const TemplateArgumentLoc *PartialSpecTemplateArgs
1742    = PartialSpec->getTemplateArgsAsWritten();
1743  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1744
1745  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1746  for (unsigned I = 0; I != N; ++I) {
1747    TemplateArgumentLoc Loc;
1748    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1749      return true;
1750    InstTemplateArgs.addArgument(Loc);
1751  }
1752
1753
1754  // Check that the template argument list is well-formed for this
1755  // class template.
1756  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1757                                        InstTemplateArgs.size());
1758  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1759                                        PartialSpec->getLocation(),
1760                                        InstTemplateArgs,
1761                                        false,
1762                                        Converted))
1763    return true;
1764
1765  // Figure out where to insert this class template partial specialization
1766  // in the member template's set of class template partial specializations.
1767  llvm::FoldingSetNodeID ID;
1768  ClassTemplatePartialSpecializationDecl::Profile(ID,
1769                                                  Converted.getFlatArguments(),
1770                                                  Converted.flatSize(),
1771                                                  SemaRef.Context);
1772  void *InsertPos = 0;
1773  ClassTemplateSpecializationDecl *PrevDecl
1774    = ClassTemplate->getPartialSpecializations().FindNodeOrInsertPos(ID,
1775                                                                     InsertPos);
1776
1777  // Build the canonical type that describes the converted template
1778  // arguments of the class template partial specialization.
1779  QualType CanonType
1780    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1781                                                  Converted.getFlatArguments(),
1782                                                    Converted.flatSize());
1783
1784  // Build the fully-sugared type for this class template
1785  // specialization as the user wrote in the specialization
1786  // itself. This means that we'll pretty-print the type retrieved
1787  // from the specialization's declaration the way that the user
1788  // actually wrote the specialization, rather than formatting the
1789  // name based on the "canonical" representation used to store the
1790  // template arguments in the specialization.
1791  TypeSourceInfo *WrittenTy
1792    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1793                                                    TemplateName(ClassTemplate),
1794                                                    PartialSpec->getLocation(),
1795                                                    InstTemplateArgs,
1796                                                    CanonType);
1797
1798  if (PrevDecl) {
1799    // We've already seen a partial specialization with the same template
1800    // parameters and template arguments. This can happen, for example, when
1801    // substituting the outer template arguments ends up causing two
1802    // class template partial specializations of a member class template
1803    // to have identical forms, e.g.,
1804    //
1805    //   template<typename T, typename U>
1806    //   struct Outer {
1807    //     template<typename X, typename Y> struct Inner;
1808    //     template<typename Y> struct Inner<T, Y>;
1809    //     template<typename Y> struct Inner<U, Y>;
1810    //   };
1811    //
1812    //   Outer<int, int> outer; // error: the partial specializations of Inner
1813    //                          // have the same signature.
1814    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1815      << WrittenTy;
1816    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1817      << SemaRef.Context.getTypeDeclType(PrevDecl);
1818    return true;
1819  }
1820
1821
1822  // Create the class template partial specialization declaration.
1823  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1824    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
1825                                                     PartialSpec->getTagKind(),
1826                                                     Owner,
1827                                                     PartialSpec->getLocation(),
1828                                                     InstParams,
1829                                                     ClassTemplate,
1830                                                     Converted,
1831                                                     InstTemplateArgs,
1832                                                     CanonType,
1833                                                     0,
1834                             ClassTemplate->getPartialSpecializations().size());
1835  // Substitute the nested name specifier, if any.
1836  if (SubstQualifier(PartialSpec, InstPartialSpec))
1837    return 0;
1838
1839  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1840  InstPartialSpec->setTypeAsWritten(WrittenTy);
1841
1842  // Add this partial specialization to the set of class template partial
1843  // specializations.
1844  ClassTemplate->getPartialSpecializations().InsertNode(InstPartialSpec,
1845                                                        InsertPos);
1846  return false;
1847}
1848
1849TypeSourceInfo*
1850TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1851                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1852  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1853  assert(OldTInfo && "substituting function without type source info");
1854  assert(Params.empty() && "parameter vector is non-empty at start");
1855  TypeSourceInfo *NewTInfo
1856    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
1857                                    D->getTypeSpecStartLoc(),
1858                                    D->getDeclName());
1859  if (!NewTInfo)
1860    return 0;
1861
1862  if (NewTInfo != OldTInfo) {
1863    // Get parameters from the new type info.
1864    TypeLoc OldTL = OldTInfo->getTypeLoc();
1865    if (FunctionProtoTypeLoc *OldProtoLoc
1866                                  = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1867      TypeLoc NewTL = NewTInfo->getTypeLoc();
1868      FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1869      assert(NewProtoLoc && "Missing prototype?");
1870      for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i) {
1871        // FIXME: Variadic templates will break this.
1872        Params.push_back(NewProtoLoc->getArg(i));
1873        SemaRef.CurrentInstantiationScope->InstantiatedLocal(
1874                                                        OldProtoLoc->getArg(i),
1875                                                        NewProtoLoc->getArg(i));
1876      }
1877    }
1878  } else {
1879    // The function type itself was not dependent and therefore no
1880    // substitution occurred. However, we still need to instantiate
1881    // the function parameters themselves.
1882    TypeLoc OldTL = OldTInfo->getTypeLoc();
1883    if (FunctionProtoTypeLoc *OldProtoLoc
1884                                    = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1885      for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
1886        ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
1887        if (!Parm)
1888          return 0;
1889        Params.push_back(Parm);
1890      }
1891    }
1892  }
1893  return NewTInfo;
1894}
1895
1896/// \brief Initializes the common fields of an instantiation function
1897/// declaration (New) from the corresponding fields of its template (Tmpl).
1898///
1899/// \returns true if there was an error
1900bool
1901TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1902                                                    FunctionDecl *Tmpl) {
1903  if (Tmpl->isDeleted())
1904    New->setDeleted();
1905
1906  // If we are performing substituting explicitly-specified template arguments
1907  // or deduced template arguments into a function template and we reach this
1908  // point, we are now past the point where SFINAE applies and have committed
1909  // to keeping the new function template specialization. We therefore
1910  // convert the active template instantiation for the function template
1911  // into a template instantiation for this specific function template
1912  // specialization, which is not a SFINAE context, so that we diagnose any
1913  // further errors in the declaration itself.
1914  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1915  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1916  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1917      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1918    if (FunctionTemplateDecl *FunTmpl
1919          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1920      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1921             "Deduction from the wrong function template?");
1922      (void) FunTmpl;
1923      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1924      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1925      --SemaRef.NonInstantiationEntries;
1926    }
1927  }
1928
1929  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1930  assert(Proto && "Function template without prototype?");
1931
1932  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1933      Proto->getNoReturnAttr()) {
1934    // The function has an exception specification or a "noreturn"
1935    // attribute. Substitute into each of the exception types.
1936    llvm::SmallVector<QualType, 4> Exceptions;
1937    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1938      // FIXME: Poor location information!
1939      QualType T
1940        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1941                            New->getLocation(), New->getDeclName());
1942      if (T.isNull() ||
1943          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1944        continue;
1945
1946      Exceptions.push_back(T);
1947    }
1948
1949    // Rebuild the function type
1950
1951    const FunctionProtoType *NewProto
1952      = New->getType()->getAs<FunctionProtoType>();
1953    assert(NewProto && "Template instantiation without function prototype?");
1954    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1955                                                 NewProto->arg_type_begin(),
1956                                                 NewProto->getNumArgs(),
1957                                                 NewProto->isVariadic(),
1958                                                 NewProto->getTypeQuals(),
1959                                                 Proto->hasExceptionSpec(),
1960                                                 Proto->hasAnyExceptionSpec(),
1961                                                 Exceptions.size(),
1962                                                 Exceptions.data(),
1963                                                 Proto->getExtInfo()));
1964  }
1965
1966  return false;
1967}
1968
1969/// \brief Initializes common fields of an instantiated method
1970/// declaration (New) from the corresponding fields of its template
1971/// (Tmpl).
1972///
1973/// \returns true if there was an error
1974bool
1975TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
1976                                                  CXXMethodDecl *Tmpl) {
1977  if (InitFunctionInstantiation(New, Tmpl))
1978    return true;
1979
1980  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
1981  New->setAccess(Tmpl->getAccess());
1982  if (Tmpl->isVirtualAsWritten())
1983    Record->setMethodAsVirtual(New);
1984
1985  // FIXME: attributes
1986  // FIXME: New needs a pointer to Tmpl
1987  return false;
1988}
1989
1990/// \brief Instantiate the definition of the given function from its
1991/// template.
1992///
1993/// \param PointOfInstantiation the point at which the instantiation was
1994/// required. Note that this is not precisely a "point of instantiation"
1995/// for the function, but it's close.
1996///
1997/// \param Function the already-instantiated declaration of a
1998/// function template specialization or member function of a class template
1999/// specialization.
2000///
2001/// \param Recursive if true, recursively instantiates any functions that
2002/// are required by this instantiation.
2003///
2004/// \param DefinitionRequired if true, then we are performing an explicit
2005/// instantiation where the body of the function is required. Complain if
2006/// there is no such body.
2007void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
2008                                         FunctionDecl *Function,
2009                                         bool Recursive,
2010                                         bool DefinitionRequired) {
2011  if (Function->isInvalidDecl() || Function->getBody())
2012    return;
2013
2014  // Never instantiate an explicit specialization.
2015  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2016    return;
2017
2018  // Find the function body that we'll be substituting.
2019  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
2020  Stmt *Pattern = 0;
2021  if (PatternDecl)
2022    Pattern = PatternDecl->getBody(PatternDecl);
2023
2024  if (!Pattern) {
2025    if (DefinitionRequired) {
2026      if (Function->getPrimaryTemplate())
2027        Diag(PointOfInstantiation,
2028             diag::err_explicit_instantiation_undefined_func_template)
2029          << Function->getPrimaryTemplate();
2030      else
2031        Diag(PointOfInstantiation,
2032             diag::err_explicit_instantiation_undefined_member)
2033          << 1 << Function->getDeclName() << Function->getDeclContext();
2034
2035      if (PatternDecl)
2036        Diag(PatternDecl->getLocation(),
2037             diag::note_explicit_instantiation_here);
2038      Function->setInvalidDecl();
2039    }
2040
2041    return;
2042  }
2043
2044  // C++0x [temp.explicit]p9:
2045  //   Except for inline functions, other explicit instantiation declarations
2046  //   have the effect of suppressing the implicit instantiation of the entity
2047  //   to which they refer.
2048  if (Function->getTemplateSpecializationKind()
2049        == TSK_ExplicitInstantiationDeclaration &&
2050      !PatternDecl->isInlined())
2051    return;
2052
2053  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2054  if (Inst)
2055    return;
2056
2057  // If we're performing recursive template instantiation, create our own
2058  // queue of pending implicit instantiations that we will instantiate later,
2059  // while we're still within our own instantiation context.
2060  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2061  if (Recursive)
2062    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2063
2064  EnterExpressionEvaluationContext EvalContext(*this,
2065                                               Action::PotentiallyEvaluated);
2066  ActOnStartOfFunctionDef(0, DeclPtrTy::make(Function));
2067
2068  // Introduce a new scope where local variable instantiations will be
2069  // recorded, unless we're actually a member function within a local
2070  // class, in which case we need to merge our results with the parent
2071  // scope (of the enclosing function).
2072  bool MergeWithParentScope = false;
2073  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2074    MergeWithParentScope = Rec->isLocalClass();
2075
2076  LocalInstantiationScope Scope(*this, MergeWithParentScope);
2077
2078  // Introduce the instantiated function parameters into the local
2079  // instantiation scope.
2080  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I)
2081    Scope.InstantiatedLocal(PatternDecl->getParamDecl(I),
2082                            Function->getParamDecl(I));
2083
2084  // Enter the scope of this instantiation. We don't use
2085  // PushDeclContext because we don't have a scope.
2086  DeclContext *PreviousContext = CurContext;
2087  CurContext = Function;
2088
2089  MultiLevelTemplateArgumentList TemplateArgs =
2090    getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
2091
2092  // If this is a constructor, instantiate the member initializers.
2093  if (const CXXConstructorDecl *Ctor =
2094        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2095    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2096                               TemplateArgs);
2097  }
2098
2099  // Instantiate the function body.
2100  OwningStmtResult Body = SubstStmt(Pattern, TemplateArgs);
2101
2102  if (Body.isInvalid())
2103    Function->setInvalidDecl();
2104
2105  ActOnFinishFunctionBody(DeclPtrTy::make(Function), move(Body),
2106                          /*IsInstantiation=*/true);
2107
2108  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2109
2110  CurContext = PreviousContext;
2111
2112  DeclGroupRef DG(Function);
2113  Consumer.HandleTopLevelDecl(DG);
2114
2115  // This class may have local implicit instantiations that need to be
2116  // instantiation within this scope.
2117  PerformPendingImplicitInstantiations(/*LocalOnly=*/true);
2118  Scope.Exit();
2119
2120  if (Recursive) {
2121    // Instantiate any pending implicit instantiations found during the
2122    // instantiation of this template.
2123    PerformPendingImplicitInstantiations();
2124
2125    // Restore the set of pending implicit instantiations.
2126    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2127  }
2128}
2129
2130/// \brief Instantiate the definition of the given variable from its
2131/// template.
2132///
2133/// \param PointOfInstantiation the point at which the instantiation was
2134/// required. Note that this is not precisely a "point of instantiation"
2135/// for the function, but it's close.
2136///
2137/// \param Var the already-instantiated declaration of a static member
2138/// variable of a class template specialization.
2139///
2140/// \param Recursive if true, recursively instantiates any functions that
2141/// are required by this instantiation.
2142///
2143/// \param DefinitionRequired if true, then we are performing an explicit
2144/// instantiation where an out-of-line definition of the member variable
2145/// is required. Complain if there is no such definition.
2146void Sema::InstantiateStaticDataMemberDefinition(
2147                                          SourceLocation PointOfInstantiation,
2148                                                 VarDecl *Var,
2149                                                 bool Recursive,
2150                                                 bool DefinitionRequired) {
2151  if (Var->isInvalidDecl())
2152    return;
2153
2154  // Find the out-of-line definition of this static data member.
2155  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2156  assert(Def && "This data member was not instantiated from a template?");
2157  assert(Def->isStaticDataMember() && "Not a static data member?");
2158  Def = Def->getOutOfLineDefinition();
2159
2160  if (!Def) {
2161    // We did not find an out-of-line definition of this static data member,
2162    // so we won't perform any instantiation. Rather, we rely on the user to
2163    // instantiate this definition (or provide a specialization for it) in
2164    // another translation unit.
2165    if (DefinitionRequired) {
2166      Def = Var->getInstantiatedFromStaticDataMember();
2167      Diag(PointOfInstantiation,
2168           diag::err_explicit_instantiation_undefined_member)
2169        << 2 << Var->getDeclName() << Var->getDeclContext();
2170      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2171    }
2172
2173    return;
2174  }
2175
2176  // Never instantiate an explicit specialization.
2177  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2178    return;
2179
2180  // C++0x [temp.explicit]p9:
2181  //   Except for inline functions, other explicit instantiation declarations
2182  //   have the effect of suppressing the implicit instantiation of the entity
2183  //   to which they refer.
2184  if (Var->getTemplateSpecializationKind()
2185        == TSK_ExplicitInstantiationDeclaration)
2186    return;
2187
2188  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2189  if (Inst)
2190    return;
2191
2192  // If we're performing recursive template instantiation, create our own
2193  // queue of pending implicit instantiations that we will instantiate later,
2194  // while we're still within our own instantiation context.
2195  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2196  if (Recursive)
2197    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2198
2199  // Enter the scope of this instantiation. We don't use
2200  // PushDeclContext because we don't have a scope.
2201  DeclContext *PreviousContext = CurContext;
2202  CurContext = Var->getDeclContext();
2203
2204  VarDecl *OldVar = Var;
2205  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2206                                          getTemplateInstantiationArgs(Var)));
2207  CurContext = PreviousContext;
2208
2209  if (Var) {
2210    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2211    assert(MSInfo && "Missing member specialization information?");
2212    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2213                                       MSInfo->getPointOfInstantiation());
2214    DeclGroupRef DG(Var);
2215    Consumer.HandleTopLevelDecl(DG);
2216  }
2217
2218  if (Recursive) {
2219    // Instantiate any pending implicit instantiations found during the
2220    // instantiation of this template.
2221    PerformPendingImplicitInstantiations();
2222
2223    // Restore the set of pending implicit instantiations.
2224    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2225  }
2226}
2227
2228void
2229Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2230                                 const CXXConstructorDecl *Tmpl,
2231                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2232
2233  llvm::SmallVector<MemInitTy*, 4> NewInits;
2234  bool AnyErrors = false;
2235
2236  // Instantiate all the initializers.
2237  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2238                                            InitsEnd = Tmpl->init_end();
2239       Inits != InitsEnd; ++Inits) {
2240    CXXBaseOrMemberInitializer *Init = *Inits;
2241
2242    SourceLocation LParenLoc, RParenLoc;
2243    ASTOwningVector<&ActionBase::DeleteExpr> NewArgs(*this);
2244    llvm::SmallVector<SourceLocation, 4> CommaLocs;
2245
2246    // Instantiate the initializer.
2247    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2248                               LParenLoc, CommaLocs, NewArgs, RParenLoc)) {
2249      AnyErrors = true;
2250      continue;
2251    }
2252
2253    MemInitResult NewInit;
2254    if (Init->isBaseInitializer()) {
2255      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2256                                            TemplateArgs,
2257                                            Init->getSourceLocation(),
2258                                            New->getDeclName());
2259      if (!BaseTInfo) {
2260        AnyErrors = true;
2261        New->setInvalidDecl();
2262        continue;
2263      }
2264
2265      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2266                                     (Expr **)NewArgs.data(),
2267                                     NewArgs.size(),
2268                                     Init->getLParenLoc(),
2269                                     Init->getRParenLoc(),
2270                                     New->getParent());
2271    } else if (Init->isMemberInitializer()) {
2272      FieldDecl *Member;
2273
2274      // Is this an anonymous union?
2275      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2276        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2277                                                      UnionInit, TemplateArgs));
2278      else
2279        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2280                                                      Init->getMember(),
2281                                                      TemplateArgs));
2282
2283      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2284                                       NewArgs.size(),
2285                                       Init->getSourceLocation(),
2286                                       Init->getLParenLoc(),
2287                                       Init->getRParenLoc());
2288    }
2289
2290    if (NewInit.isInvalid()) {
2291      AnyErrors = true;
2292      New->setInvalidDecl();
2293    } else {
2294      // FIXME: It would be nice if ASTOwningVector had a release function.
2295      NewArgs.take();
2296
2297      NewInits.push_back((MemInitTy *)NewInit.get());
2298    }
2299  }
2300
2301  // Assign all the initializers to the new constructor.
2302  ActOnMemInitializers(DeclPtrTy::make(New),
2303                       /*FIXME: ColonLoc */
2304                       SourceLocation(),
2305                       NewInits.data(), NewInits.size(),
2306                       AnyErrors);
2307}
2308
2309// TODO: this could be templated if the various decl types used the
2310// same method name.
2311static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2312                              ClassTemplateDecl *Instance) {
2313  Pattern = Pattern->getCanonicalDecl();
2314
2315  do {
2316    Instance = Instance->getCanonicalDecl();
2317    if (Pattern == Instance) return true;
2318    Instance = Instance->getInstantiatedFromMemberTemplate();
2319  } while (Instance);
2320
2321  return false;
2322}
2323
2324static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2325                              FunctionTemplateDecl *Instance) {
2326  Pattern = Pattern->getCanonicalDecl();
2327
2328  do {
2329    Instance = Instance->getCanonicalDecl();
2330    if (Pattern == Instance) return true;
2331    Instance = Instance->getInstantiatedFromMemberTemplate();
2332  } while (Instance);
2333
2334  return false;
2335}
2336
2337static bool
2338isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2339                  ClassTemplatePartialSpecializationDecl *Instance) {
2340  Pattern
2341    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2342  do {
2343    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2344                                                Instance->getCanonicalDecl());
2345    if (Pattern == Instance)
2346      return true;
2347    Instance = Instance->getInstantiatedFromMember();
2348  } while (Instance);
2349
2350  return false;
2351}
2352
2353static bool isInstantiationOf(CXXRecordDecl *Pattern,
2354                              CXXRecordDecl *Instance) {
2355  Pattern = Pattern->getCanonicalDecl();
2356
2357  do {
2358    Instance = Instance->getCanonicalDecl();
2359    if (Pattern == Instance) return true;
2360    Instance = Instance->getInstantiatedFromMemberClass();
2361  } while (Instance);
2362
2363  return false;
2364}
2365
2366static bool isInstantiationOf(FunctionDecl *Pattern,
2367                              FunctionDecl *Instance) {
2368  Pattern = Pattern->getCanonicalDecl();
2369
2370  do {
2371    Instance = Instance->getCanonicalDecl();
2372    if (Pattern == Instance) return true;
2373    Instance = Instance->getInstantiatedFromMemberFunction();
2374  } while (Instance);
2375
2376  return false;
2377}
2378
2379static bool isInstantiationOf(EnumDecl *Pattern,
2380                              EnumDecl *Instance) {
2381  Pattern = Pattern->getCanonicalDecl();
2382
2383  do {
2384    Instance = Instance->getCanonicalDecl();
2385    if (Pattern == Instance) return true;
2386    Instance = Instance->getInstantiatedFromMemberEnum();
2387  } while (Instance);
2388
2389  return false;
2390}
2391
2392static bool isInstantiationOf(UsingShadowDecl *Pattern,
2393                              UsingShadowDecl *Instance,
2394                              ASTContext &C) {
2395  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2396}
2397
2398static bool isInstantiationOf(UsingDecl *Pattern,
2399                              UsingDecl *Instance,
2400                              ASTContext &C) {
2401  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2402}
2403
2404static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2405                              UsingDecl *Instance,
2406                              ASTContext &C) {
2407  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2408}
2409
2410static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2411                              UsingDecl *Instance,
2412                              ASTContext &C) {
2413  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2414}
2415
2416static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2417                                              VarDecl *Instance) {
2418  assert(Instance->isStaticDataMember());
2419
2420  Pattern = Pattern->getCanonicalDecl();
2421
2422  do {
2423    Instance = Instance->getCanonicalDecl();
2424    if (Pattern == Instance) return true;
2425    Instance = Instance->getInstantiatedFromStaticDataMember();
2426  } while (Instance);
2427
2428  return false;
2429}
2430
2431// Other is the prospective instantiation
2432// D is the prospective pattern
2433static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2434  if (D->getKind() != Other->getKind()) {
2435    if (UnresolvedUsingTypenameDecl *UUD
2436          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2437      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2438        return isInstantiationOf(UUD, UD, Ctx);
2439      }
2440    }
2441
2442    if (UnresolvedUsingValueDecl *UUD
2443          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2444      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2445        return isInstantiationOf(UUD, UD, Ctx);
2446      }
2447    }
2448
2449    return false;
2450  }
2451
2452  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2453    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2454
2455  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2456    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2457
2458  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2459    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2460
2461  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2462    if (Var->isStaticDataMember())
2463      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2464
2465  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2466    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2467
2468  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2469    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2470
2471  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2472        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2473    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2474                             PartialSpec);
2475
2476  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2477    if (!Field->getDeclName()) {
2478      // This is an unnamed field.
2479      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2480        cast<FieldDecl>(D);
2481    }
2482  }
2483
2484  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2485    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2486
2487  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2488    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2489
2490  return D->getDeclName() && isa<NamedDecl>(Other) &&
2491    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2492}
2493
2494template<typename ForwardIterator>
2495static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2496                                      NamedDecl *D,
2497                                      ForwardIterator first,
2498                                      ForwardIterator last) {
2499  for (; first != last; ++first)
2500    if (isInstantiationOf(Ctx, D, *first))
2501      return cast<NamedDecl>(*first);
2502
2503  return 0;
2504}
2505
2506/// \brief Finds the instantiation of the given declaration context
2507/// within the current instantiation.
2508///
2509/// \returns NULL if there was an error
2510DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2511                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2512  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2513    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2514    return cast_or_null<DeclContext>(ID);
2515  } else return DC;
2516}
2517
2518/// \brief Find the instantiation of the given declaration within the
2519/// current instantiation.
2520///
2521/// This routine is intended to be used when \p D is a declaration
2522/// referenced from within a template, that needs to mapped into the
2523/// corresponding declaration within an instantiation. For example,
2524/// given:
2525///
2526/// \code
2527/// template<typename T>
2528/// struct X {
2529///   enum Kind {
2530///     KnownValue = sizeof(T)
2531///   };
2532///
2533///   bool getKind() const { return KnownValue; }
2534/// };
2535///
2536/// template struct X<int>;
2537/// \endcode
2538///
2539/// In the instantiation of X<int>::getKind(), we need to map the
2540/// EnumConstantDecl for KnownValue (which refers to
2541/// X<T>::<Kind>::KnownValue) to its instantiation
2542/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2543/// this mapping from within the instantiation of X<int>.
2544NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2545                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2546  DeclContext *ParentDC = D->getDeclContext();
2547  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2548      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2549      ParentDC->isFunctionOrMethod()) {
2550    // D is a local of some kind. Look into the map of local
2551    // declarations to their instantiations.
2552    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2553  }
2554
2555  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2556    if (!Record->isDependentContext())
2557      return D;
2558
2559    // If the RecordDecl is actually the injected-class-name or a
2560    // "templated" declaration for a class template, class template
2561    // partial specialization, or a member class of a class template,
2562    // substitute into the injected-class-name of the class template
2563    // or partial specialization to find the new DeclContext.
2564    QualType T;
2565    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2566
2567    if (ClassTemplate) {
2568      T = ClassTemplate->getInjectedClassNameSpecialization(Context);
2569    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2570                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2571      ClassTemplate = PartialSpec->getSpecializedTemplate();
2572
2573      // If we call SubstType with an InjectedClassNameType here we
2574      // can end up in an infinite loop.
2575      T = Context.getTypeDeclType(Record);
2576      assert(isa<InjectedClassNameType>(T) &&
2577             "type of partial specialization is not an InjectedClassNameType");
2578      T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
2579    }
2580
2581    if (!T.isNull()) {
2582      // Substitute into the injected-class-name to get the type
2583      // corresponding to the instantiation we want, which may also be
2584      // the current instantiation (if we're in a template
2585      // definition). This substitution should never fail, since we
2586      // know we can instantiate the injected-class-name or we
2587      // wouldn't have gotten to the injected-class-name!
2588
2589      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2590      // extra instantiation in the common case?
2591      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2592      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2593
2594      if (!T->isDependentType()) {
2595        assert(T->isRecordType() && "Instantiation must produce a record type");
2596        return T->getAs<RecordType>()->getDecl();
2597      }
2598
2599      // We are performing "partial" template instantiation to create
2600      // the member declarations for the members of a class template
2601      // specialization. Therefore, D is actually referring to something
2602      // in the current instantiation. Look through the current
2603      // context, which contains actual instantiations, to find the
2604      // instantiation of the "current instantiation" that D refers
2605      // to.
2606      bool SawNonDependentContext = false;
2607      for (DeclContext *DC = CurContext; !DC->isFileContext();
2608           DC = DC->getParent()) {
2609        if (ClassTemplateSpecializationDecl *Spec
2610                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2611          if (isInstantiationOf(ClassTemplate,
2612                                Spec->getSpecializedTemplate()))
2613            return Spec;
2614
2615        if (!DC->isDependentContext())
2616          SawNonDependentContext = true;
2617      }
2618
2619      // We're performing "instantiation" of a member of the current
2620      // instantiation while we are type-checking the
2621      // definition. Compute the declaration context and return that.
2622      assert(!SawNonDependentContext &&
2623             "No dependent context while instantiating record");
2624      DeclContext *DC = computeDeclContext(T);
2625      assert(DC &&
2626             "Unable to find declaration for the current instantiation");
2627      return cast<CXXRecordDecl>(DC);
2628    }
2629
2630    // Fall through to deal with other dependent record types (e.g.,
2631    // anonymous unions in class templates).
2632  }
2633
2634  if (!ParentDC->isDependentContext())
2635    return D;
2636
2637  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2638  if (!ParentDC)
2639    return 0;
2640
2641  if (ParentDC != D->getDeclContext()) {
2642    // We performed some kind of instantiation in the parent context,
2643    // so now we need to look into the instantiated parent context to
2644    // find the instantiation of the declaration D.
2645
2646    // If our context used to be dependent, we may need to instantiate
2647    // it before performing lookup into that context.
2648    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2649      if (!Spec->isDependentContext()) {
2650        QualType T = Context.getTypeDeclType(Spec);
2651        const RecordType *Tag = T->getAs<RecordType>();
2652        assert(Tag && "type of non-dependent record is not a RecordType");
2653        if (!Tag->isBeingDefined() &&
2654            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2655          return 0;
2656      }
2657    }
2658
2659    NamedDecl *Result = 0;
2660    if (D->getDeclName()) {
2661      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2662      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2663    } else {
2664      // Since we don't have a name for the entity we're looking for,
2665      // our only option is to walk through all of the declarations to
2666      // find that name. This will occur in a few cases:
2667      //
2668      //   - anonymous struct/union within a template
2669      //   - unnamed class/struct/union/enum within a template
2670      //
2671      // FIXME: Find a better way to find these instantiations!
2672      Result = findInstantiationOf(Context, D,
2673                                   ParentDC->decls_begin(),
2674                                   ParentDC->decls_end());
2675    }
2676
2677    // UsingShadowDecls can instantiate to nothing because of using hiding.
2678    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2679            cast<Decl>(ParentDC)->isInvalidDecl())
2680           && "Unable to find instantiation of declaration!");
2681
2682    D = Result;
2683  }
2684
2685  return D;
2686}
2687
2688/// \brief Performs template instantiation for all implicit template
2689/// instantiations we have seen until this point.
2690void Sema::PerformPendingImplicitInstantiations(bool LocalOnly) {
2691  while (!PendingLocalImplicitInstantiations.empty() ||
2692         (!LocalOnly && !PendingImplicitInstantiations.empty())) {
2693    PendingImplicitInstantiation Inst;
2694
2695    if (PendingLocalImplicitInstantiations.empty()) {
2696      Inst = PendingImplicitInstantiations.front();
2697      PendingImplicitInstantiations.pop_front();
2698    } else {
2699      Inst = PendingLocalImplicitInstantiations.front();
2700      PendingLocalImplicitInstantiations.pop_front();
2701    }
2702
2703    // Instantiate function definitions
2704    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2705      PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Function),
2706                                            Function->getLocation(), *this,
2707                                            Context.getSourceManager(),
2708                                           "instantiating function definition");
2709
2710      InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true);
2711      continue;
2712    }
2713
2714    // Instantiate static data member definitions.
2715    VarDecl *Var = cast<VarDecl>(Inst.first);
2716    assert(Var->isStaticDataMember() && "Not a static data member?");
2717
2718    // Don't try to instantiate declarations if the most recent redeclaration
2719    // is invalid.
2720    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2721      continue;
2722
2723    // Check if the most recent declaration has changed the specialization kind
2724    // and removed the need for implicit instantiation.
2725    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2726    case TSK_Undeclared:
2727      assert(false && "Cannot instantitiate an undeclared specialization.");
2728    case TSK_ExplicitInstantiationDeclaration:
2729    case TSK_ExplicitInstantiationDefinition:
2730    case TSK_ExplicitSpecialization:
2731      continue;  // No longer need implicit instantiation.
2732    case TSK_ImplicitInstantiation:
2733      break;
2734    }
2735
2736    PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Var),
2737                                          Var->getLocation(), *this,
2738                                          Context.getSourceManager(),
2739                                          "instantiating static data member "
2740                                          "definition");
2741
2742    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true);
2743  }
2744}
2745
2746void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2747                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2748  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2749         E = Pattern->ddiag_end(); I != E; ++I) {
2750    DependentDiagnostic *DD = *I;
2751
2752    switch (DD->getKind()) {
2753    case DependentDiagnostic::Access:
2754      HandleDependentAccessCheck(*DD, TemplateArgs);
2755      break;
2756    }
2757  }
2758}
2759