SemaTemplateInstantiateDecl.cpp revision 2ef223af811fbd9070a01514ee049e50a072a06b 
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  }
195
196  // Create the new typedef
197  TypedefDecl *Typedef
198    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
199                          D->getIdentifier(), DI);
200  if (Invalid)
201    Typedef->setInvalidDecl();
202
203  if (TypedefDecl *Prev = D->getPreviousDeclaration()) {
204    NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
205                                                       TemplateArgs);
206    Typedef->setPreviousDeclaration(cast<TypedefDecl>(InstPrev));
207  }
208
209  Typedef->setAccess(D->getAccess());
210  Owner->addDecl(Typedef);
211
212  return Typedef;
213}
214
215/// \brief Instantiate the arguments provided as part of initialization.
216///
217/// \returns true if an error occurred, false otherwise.
218static bool InstantiateInitializationArguments(Sema &SemaRef,
219                                               Expr **Args, unsigned NumArgs,
220                           const MultiLevelTemplateArgumentList &TemplateArgs,
221                         llvm::SmallVectorImpl<SourceLocation> &FakeCommaLocs,
222                           ASTOwningVector<&ActionBase::DeleteExpr> &InitArgs) {
223  for (unsigned I = 0; I != NumArgs; ++I) {
224    // When we hit the first defaulted argument, break out of the loop:
225    // we don't pass those default arguments on.
226    if (Args[I]->isDefaultArgument())
227      break;
228
229    Sema::OwningExprResult Arg = SemaRef.SubstExpr(Args[I], TemplateArgs);
230    if (Arg.isInvalid())
231      return true;
232
233    Expr *ArgExpr = (Expr *)Arg.get();
234    InitArgs.push_back(Arg.release());
235
236    // FIXME: We're faking all of the comma locations. Do we need them?
237    FakeCommaLocs.push_back(
238                          SemaRef.PP.getLocForEndOfToken(ArgExpr->getLocEnd()));
239  }
240
241  return false;
242}
243
244/// \brief Instantiate an initializer, breaking it into separate
245/// initialization arguments.
246///
247/// \param S The semantic analysis object.
248///
249/// \param Init The initializer to instantiate.
250///
251/// \param TemplateArgs Template arguments to be substituted into the
252/// initializer.
253///
254/// \param NewArgs Will be filled in with the instantiation arguments.
255///
256/// \returns true if an error occurred, false otherwise
257static bool InstantiateInitializer(Sema &S, Expr *Init,
258                            const MultiLevelTemplateArgumentList &TemplateArgs,
259                                   SourceLocation &LParenLoc,
260                               llvm::SmallVector<SourceLocation, 4> &CommaLocs,
261                             ASTOwningVector<&ActionBase::DeleteExpr> &NewArgs,
262                                   SourceLocation &RParenLoc) {
263  NewArgs.clear();
264  LParenLoc = SourceLocation();
265  RParenLoc = SourceLocation();
266
267  if (!Init)
268    return false;
269
270  if (CXXExprWithTemporaries *ExprTemp = dyn_cast<CXXExprWithTemporaries>(Init))
271    Init = ExprTemp->getSubExpr();
272
273  while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init))
274    Init = Binder->getSubExpr();
275
276  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
277    Init = ICE->getSubExprAsWritten();
278
279  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
280    LParenLoc = ParenList->getLParenLoc();
281    RParenLoc = ParenList->getRParenLoc();
282    return InstantiateInitializationArguments(S, ParenList->getExprs(),
283                                              ParenList->getNumExprs(),
284                                              TemplateArgs, CommaLocs,
285                                              NewArgs);
286  }
287
288  if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) {
289    if (!isa<CXXTemporaryObjectExpr>(Construct)) {
290      if (InstantiateInitializationArguments(S,
291                                             Construct->getArgs(),
292                                             Construct->getNumArgs(),
293                                             TemplateArgs,
294                                             CommaLocs, NewArgs))
295        return true;
296
297      // FIXME: Fake locations!
298      LParenLoc = S.PP.getLocForEndOfToken(Init->getLocStart());
299      RParenLoc = CommaLocs.empty()? LParenLoc : CommaLocs.back();
300      return false;
301    }
302  }
303
304  Sema::OwningExprResult Result = S.SubstExpr(Init, TemplateArgs);
305  if (Result.isInvalid())
306    return true;
307
308  NewArgs.push_back(Result.takeAs<Expr>());
309  return false;
310}
311
312Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
313  // Do substitution on the type of the declaration
314  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
315                                         TemplateArgs,
316                                         D->getTypeSpecStartLoc(),
317                                         D->getDeclName());
318  if (!DI)
319    return 0;
320
321  // Build the instantiated declaration
322  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
323                                 D->getLocation(), D->getIdentifier(),
324                                 DI->getType(), DI,
325                                 D->getStorageClass());
326  Var->setThreadSpecified(D->isThreadSpecified());
327  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
328  Var->setDeclaredInCondition(D->isDeclaredInCondition());
329
330  // Substitute the nested name specifier, if any.
331  if (SubstQualifier(D, Var))
332    return 0;
333
334  // If we are instantiating a static data member defined
335  // out-of-line, the instantiation will have the same lexical
336  // context (which will be a namespace scope) as the template.
337  if (D->isOutOfLine())
338    Var->setLexicalDeclContext(D->getLexicalDeclContext());
339
340  Var->setAccess(D->getAccess());
341
342  // FIXME: In theory, we could have a previous declaration for variables that
343  // are not static data members.
344  bool Redeclaration = false;
345  // FIXME: having to fake up a LookupResult is dumb.
346  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
347                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
348  if (D->isStaticDataMember())
349    SemaRef.LookupQualifiedName(Previous, Owner, false);
350  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
351
352  if (D->isOutOfLine()) {
353    D->getLexicalDeclContext()->addDecl(Var);
354    Owner->makeDeclVisibleInContext(Var);
355  } else {
356    Owner->addDecl(Var);
357  }
358
359  // Link instantiations of static data members back to the template from
360  // which they were instantiated.
361  if (Var->isStaticDataMember())
362    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
363                                                     TSK_ImplicitInstantiation);
364
365  if (Var->getAnyInitializer()) {
366    // We already have an initializer in the class.
367  } else if (D->getInit()) {
368    if (Var->isStaticDataMember() && !D->isOutOfLine())
369      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
370    else
371      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
372
373    // Instantiate the initializer.
374    SourceLocation LParenLoc, RParenLoc;
375    llvm::SmallVector<SourceLocation, 4> CommaLocs;
376    ASTOwningVector<&ActionBase::DeleteExpr> InitArgs(SemaRef);
377    if (!InstantiateInitializer(SemaRef, D->getInit(), TemplateArgs, LParenLoc,
378                                CommaLocs, InitArgs, RParenLoc)) {
379      // Attach the initializer to the declaration.
380      if (D->hasCXXDirectInitializer()) {
381        // Add the direct initializer to the declaration.
382        SemaRef.AddCXXDirectInitializerToDecl(Sema::DeclPtrTy::make(Var),
383                                              LParenLoc,
384                                              move_arg(InitArgs),
385                                              CommaLocs.data(),
386                                              RParenLoc);
387      } else if (InitArgs.size() == 1) {
388        Expr *Init = (Expr*)(InitArgs.take()[0]);
389        SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var),
390                                     SemaRef.Owned(Init),
391                                     false);
392      } else {
393        assert(InitArgs.size() == 0);
394        SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
395      }
396    } else {
397      // FIXME: Not too happy about invalidating the declaration
398      // because of a bogus initializer.
399      Var->setInvalidDecl();
400    }
401
402    SemaRef.PopExpressionEvaluationContext();
403  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
404    SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
405
406  return Var;
407}
408
409Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
410  bool Invalid = false;
411  TypeSourceInfo *DI = D->getTypeSourceInfo();
412  if (DI->getType()->isDependentType())  {
413    DI = SemaRef.SubstType(DI, TemplateArgs,
414                           D->getLocation(), D->getDeclName());
415    if (!DI) {
416      DI = D->getTypeSourceInfo();
417      Invalid = true;
418    } else if (DI->getType()->isFunctionType()) {
419      // C++ [temp.arg.type]p3:
420      //   If a declaration acquires a function type through a type
421      //   dependent on a template-parameter and this causes a
422      //   declaration that does not use the syntactic form of a
423      //   function declarator to have function type, the program is
424      //   ill-formed.
425      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
426        << DI->getType();
427      Invalid = true;
428    }
429  }
430
431  Expr *BitWidth = D->getBitWidth();
432  if (Invalid)
433    BitWidth = 0;
434  else if (BitWidth) {
435    // The bit-width expression is not potentially evaluated.
436    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
437
438    OwningExprResult InstantiatedBitWidth
439      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
440    if (InstantiatedBitWidth.isInvalid()) {
441      Invalid = true;
442      BitWidth = 0;
443    } else
444      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
445  }
446
447  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
448                                            DI->getType(), DI,
449                                            cast<RecordDecl>(Owner),
450                                            D->getLocation(),
451                                            D->isMutable(),
452                                            BitWidth,
453                                            D->getTypeSpecStartLoc(),
454                                            D->getAccess(),
455                                            0);
456  if (!Field) {
457    cast<Decl>(Owner)->setInvalidDecl();
458    return 0;
459  }
460
461  InstantiateAttrs(D, Field);
462
463  if (Invalid)
464    Field->setInvalidDecl();
465
466  if (!Field->getDeclName()) {
467    // Keep track of where this decl came from.
468    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
469  }
470
471  Field->setImplicit(D->isImplicit());
472  Field->setAccess(D->getAccess());
473  Owner->addDecl(Field);
474
475  return Field;
476}
477
478Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
479  // Handle friend type expressions by simply substituting template
480  // parameters into the pattern type and checking the result.
481  if (TypeSourceInfo *Ty = D->getFriendType()) {
482    TypeSourceInfo *InstTy =
483      SemaRef.SubstType(Ty, TemplateArgs,
484                        D->getLocation(), DeclarationName());
485    if (!InstTy)
486      return 0;
487
488    FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getFriendLoc(), InstTy);
489    if (!FD)
490      return 0;
491
492    FD->setAccess(AS_public);
493    Owner->addDecl(FD);
494    return FD;
495  }
496
497  NamedDecl *ND = D->getFriendDecl();
498  assert(ND && "friend decl must be a decl or a type!");
499
500  // All of the Visit implementations for the various potential friend
501  // declarations have to be carefully written to work for friend
502  // objects, with the most important detail being that the target
503  // decl should almost certainly not be placed in Owner.
504  Decl *NewND = Visit(ND);
505  if (!NewND) return 0;
506
507  FriendDecl *FD =
508    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
509                       cast<NamedDecl>(NewND), D->getFriendLoc());
510  FD->setAccess(AS_public);
511  Owner->addDecl(FD);
512  return FD;
513}
514
515Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
516  Expr *AssertExpr = D->getAssertExpr();
517
518  // The expression in a static assertion is not potentially evaluated.
519  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
520
521  OwningExprResult InstantiatedAssertExpr
522    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
523  if (InstantiatedAssertExpr.isInvalid())
524    return 0;
525
526  OwningExprResult Message(SemaRef, D->getMessage());
527  D->getMessage()->Retain();
528  Decl *StaticAssert
529    = SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
530                                           move(InstantiatedAssertExpr),
531                                           move(Message)).getAs<Decl>();
532  return StaticAssert;
533}
534
535Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
536  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
537                                    D->getLocation(), D->getIdentifier(),
538                                    D->getTagKeywordLoc(),
539                                    /*PrevDecl=*/0);
540  Enum->setInstantiationOfMemberEnum(D);
541  Enum->setAccess(D->getAccess());
542  if (SubstQualifier(D, Enum)) return 0;
543  Owner->addDecl(Enum);
544  Enum->startDefinition();
545
546  if (D->getDeclContext()->isFunctionOrMethod())
547    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
548
549  llvm::SmallVector<Sema::DeclPtrTy, 4> Enumerators;
550
551  EnumConstantDecl *LastEnumConst = 0;
552  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
553         ECEnd = D->enumerator_end();
554       EC != ECEnd; ++EC) {
555    // The specified value for the enumerator.
556    OwningExprResult Value = SemaRef.Owned((Expr *)0);
557    if (Expr *UninstValue = EC->getInitExpr()) {
558      // The enumerator's value expression is not potentially evaluated.
559      EnterExpressionEvaluationContext Unevaluated(SemaRef,
560                                                   Action::Unevaluated);
561
562      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
563    }
564
565    // Drop the initial value and continue.
566    bool isInvalid = false;
567    if (Value.isInvalid()) {
568      Value = SemaRef.Owned((Expr *)0);
569      isInvalid = true;
570    }
571
572    EnumConstantDecl *EnumConst
573      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
574                                  EC->getLocation(), EC->getIdentifier(),
575                                  move(Value));
576
577    if (isInvalid) {
578      if (EnumConst)
579        EnumConst->setInvalidDecl();
580      Enum->setInvalidDecl();
581    }
582
583    if (EnumConst) {
584      EnumConst->setAccess(Enum->getAccess());
585      Enum->addDecl(EnumConst);
586      Enumerators.push_back(Sema::DeclPtrTy::make(EnumConst));
587      LastEnumConst = EnumConst;
588
589      if (D->getDeclContext()->isFunctionOrMethod()) {
590        // If the enumeration is within a function or method, record the enum
591        // constant as a local.
592        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
593      }
594    }
595  }
596
597  // FIXME: Fixup LBraceLoc and RBraceLoc
598  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
599  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
600                        Sema::DeclPtrTy::make(Enum),
601                        &Enumerators[0], Enumerators.size(),
602                        0, 0);
603
604  return Enum;
605}
606
607Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
608  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
609  return 0;
610}
611
612namespace {
613  class SortDeclByLocation {
614    SourceManager &SourceMgr;
615
616  public:
617    explicit SortDeclByLocation(SourceManager &SourceMgr)
618      : SourceMgr(SourceMgr) { }
619
620    bool operator()(const Decl *X, const Decl *Y) const {
621      return SourceMgr.isBeforeInTranslationUnit(X->getLocation(),
622                                                 Y->getLocation());
623    }
624  };
625}
626
627Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
628  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
629
630  // Create a local instantiation scope for this class template, which
631  // will contain the instantiations of the template parameters.
632  Sema::LocalInstantiationScope Scope(SemaRef);
633  TemplateParameterList *TempParams = D->getTemplateParameters();
634  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
635  if (!InstParams)
636    return NULL;
637
638  CXXRecordDecl *Pattern = D->getTemplatedDecl();
639
640  // Instantiate the qualifier.  We have to do this first in case
641  // we're a friend declaration, because if we are then we need to put
642  // the new declaration in the appropriate context.
643  NestedNameSpecifier *Qualifier = Pattern->getQualifier();
644  if (Qualifier) {
645    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
646                                                 Pattern->getQualifierRange(),
647                                                 TemplateArgs);
648    if (!Qualifier) return 0;
649  }
650
651  CXXRecordDecl *PrevDecl = 0;
652  ClassTemplateDecl *PrevClassTemplate = 0;
653
654  // If this isn't a friend, then it's a member template, in which
655  // case we just want to build the instantiation in the
656  // specialization.  If it is a friend, we want to build it in
657  // the appropriate context.
658  DeclContext *DC = Owner;
659  if (isFriend) {
660    if (Qualifier) {
661      CXXScopeSpec SS;
662      SS.setScopeRep(Qualifier);
663      SS.setRange(Pattern->getQualifierRange());
664      DC = SemaRef.computeDeclContext(SS);
665      if (!DC) return 0;
666    } else {
667      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
668                                           Pattern->getDeclContext(),
669                                           TemplateArgs);
670    }
671
672    // Look for a previous declaration of the template in the owning
673    // context.
674    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
675                   Sema::LookupOrdinaryName, Sema::ForRedeclaration);
676    SemaRef.LookupQualifiedName(R, DC);
677
678    if (R.isSingleResult()) {
679      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
680      if (PrevClassTemplate)
681        PrevDecl = PrevClassTemplate->getTemplatedDecl();
682    }
683
684    if (!PrevClassTemplate && Qualifier) {
685      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
686        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
687        << Pattern->getQualifierRange();
688      return 0;
689    }
690
691    bool AdoptedPreviousTemplateParams = false;
692    if (PrevClassTemplate) {
693      bool Complain = true;
694
695      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
696      // template for struct std::tr1::__detail::_Map_base, where the
697      // template parameters of the friend declaration don't match the
698      // template parameters of the original declaration. In this one
699      // case, we don't complain about the ill-formed friend
700      // declaration.
701      if (isFriend && Pattern->getIdentifier() &&
702          Pattern->getIdentifier()->isStr("_Map_base") &&
703          DC->isNamespace() &&
704          cast<NamespaceDecl>(DC)->getIdentifier() &&
705          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
706        DeclContext *DCParent = DC->getParent();
707        if (DCParent->isNamespace() &&
708            cast<NamespaceDecl>(DCParent)->getIdentifier() &&
709            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
710          DeclContext *DCParent2 = DCParent->getParent();
711          if (DCParent2->isNamespace() &&
712              cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
713              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
714              DCParent2->getParent()->isTranslationUnit())
715            Complain = false;
716        }
717      }
718
719      TemplateParameterList *PrevParams
720        = PrevClassTemplate->getTemplateParameters();
721
722      // Make sure the parameter lists match.
723      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
724                                                  Complain,
725                                                  Sema::TPL_TemplateMatch)) {
726        if (Complain)
727          return 0;
728
729        AdoptedPreviousTemplateParams = true;
730        InstParams = PrevParams;
731      }
732
733      // Do some additional validation, then merge default arguments
734      // from the existing declarations.
735      if (!AdoptedPreviousTemplateParams &&
736          SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
737                                             Sema::TPC_ClassTemplate))
738        return 0;
739    }
740  }
741
742  CXXRecordDecl *RecordInst
743    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
744                            Pattern->getLocation(), Pattern->getIdentifier(),
745                            Pattern->getTagKeywordLoc(), PrevDecl,
746                            /*DelayTypeCreation=*/true);
747
748  if (Qualifier)
749    RecordInst->setQualifierInfo(Qualifier, Pattern->getQualifierRange());
750
751  ClassTemplateDecl *Inst
752    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
753                                D->getIdentifier(), InstParams, RecordInst,
754                                PrevClassTemplate);
755  RecordInst->setDescribedClassTemplate(Inst);
756
757  if (isFriend) {
758    if (PrevClassTemplate)
759      Inst->setAccess(PrevClassTemplate->getAccess());
760    else
761      Inst->setAccess(D->getAccess());
762
763    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
764    // TODO: do we want to track the instantiation progeny of this
765    // friend target decl?
766  } else {
767    Inst->setAccess(D->getAccess());
768    Inst->setInstantiatedFromMemberTemplate(D);
769  }
770
771  // Trigger creation of the type for the instantiation.
772  SemaRef.Context.getInjectedClassNameType(RecordInst,
773                  Inst->getInjectedClassNameSpecialization(SemaRef.Context));
774
775  // Finish handling of friends.
776  if (isFriend) {
777    DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
778    return Inst;
779  }
780
781  Owner->addDecl(Inst);
782
783  // First, we sort the partial specializations by location, so
784  // that we instantiate them in the order they were declared.
785  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
786  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
787         P = D->getPartialSpecializations().begin(),
788         PEnd = D->getPartialSpecializations().end();
789       P != PEnd; ++P)
790    PartialSpecs.push_back(&*P);
791  std::sort(PartialSpecs.begin(), PartialSpecs.end(),
792            SortDeclByLocation(SemaRef.SourceMgr));
793
794  // Instantiate all of the partial specializations of this member class
795  // template.
796  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
797    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
798
799  return Inst;
800}
801
802Decl *
803TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
804                                   ClassTemplatePartialSpecializationDecl *D) {
805  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
806
807  // Lookup the already-instantiated declaration in the instantiation
808  // of the class template and return that.
809  DeclContext::lookup_result Found
810    = Owner->lookup(ClassTemplate->getDeclName());
811  if (Found.first == Found.second)
812    return 0;
813
814  ClassTemplateDecl *InstClassTemplate
815    = dyn_cast<ClassTemplateDecl>(*Found.first);
816  if (!InstClassTemplate)
817    return 0;
818
819  Decl *DCanon = D->getCanonicalDecl();
820  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
821            P = InstClassTemplate->getPartialSpecializations().begin(),
822         PEnd = InstClassTemplate->getPartialSpecializations().end();
823       P != PEnd; ++P) {
824    if (P->getInstantiatedFromMember()->getCanonicalDecl() == DCanon)
825      return &*P;
826  }
827
828  return 0;
829}
830
831Decl *
832TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
833  // Create a local instantiation scope for this function template, which
834  // will contain the instantiations of the template parameters and then get
835  // merged with the local instantiation scope for the function template
836  // itself.
837  Sema::LocalInstantiationScope Scope(SemaRef);
838
839  TemplateParameterList *TempParams = D->getTemplateParameters();
840  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
841  if (!InstParams)
842    return NULL;
843
844  FunctionDecl *Instantiated = 0;
845  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
846    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
847                                                                 InstParams));
848  else
849    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
850                                                          D->getTemplatedDecl(),
851                                                                InstParams));
852
853  if (!Instantiated)
854    return 0;
855
856  Instantiated->setAccess(D->getAccess());
857
858  // Link the instantiated function template declaration to the function
859  // template from which it was instantiated.
860  FunctionTemplateDecl *InstTemplate
861    = Instantiated->getDescribedFunctionTemplate();
862  InstTemplate->setAccess(D->getAccess());
863  assert(InstTemplate &&
864         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
865
866  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
867
868  // Link the instantiation back to the pattern *unless* this is a
869  // non-definition friend declaration.
870  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
871      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
872    InstTemplate->setInstantiatedFromMemberTemplate(D);
873
874  // Make declarations visible in the appropriate context.
875  if (!isFriend)
876    Owner->addDecl(InstTemplate);
877
878  return InstTemplate;
879}
880
881Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
882  CXXRecordDecl *PrevDecl = 0;
883  if (D->isInjectedClassName())
884    PrevDecl = cast<CXXRecordDecl>(Owner);
885  else if (D->getPreviousDeclaration()) {
886    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
887                                                   D->getPreviousDeclaration(),
888                                                   TemplateArgs);
889    if (!Prev) return 0;
890    PrevDecl = cast<CXXRecordDecl>(Prev);
891  }
892
893  CXXRecordDecl *Record
894    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
895                            D->getLocation(), D->getIdentifier(),
896                            D->getTagKeywordLoc(), PrevDecl);
897
898  // Substitute the nested name specifier, if any.
899  if (SubstQualifier(D, Record))
900    return 0;
901
902  Record->setImplicit(D->isImplicit());
903  // FIXME: Check against AS_none is an ugly hack to work around the issue that
904  // the tag decls introduced by friend class declarations don't have an access
905  // specifier. Remove once this area of the code gets sorted out.
906  if (D->getAccess() != AS_none)
907    Record->setAccess(D->getAccess());
908  if (!D->isInjectedClassName())
909    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
910
911  // If the original function was part of a friend declaration,
912  // inherit its namespace state.
913  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
914    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
915
916  Record->setAnonymousStructOrUnion(D->isAnonymousStructOrUnion());
917
918  Owner->addDecl(Record);
919  return Record;
920}
921
922/// Normal class members are of more specific types and therefore
923/// don't make it here.  This function serves two purposes:
924///   1) instantiating function templates
925///   2) substituting friend declarations
926/// FIXME: preserve function definitions in case #2
927Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
928                                       TemplateParameterList *TemplateParams) {
929  // Check whether there is already a function template specialization for
930  // this declaration.
931  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
932  void *InsertPos = 0;
933  if (FunctionTemplate && !TemplateParams) {
934    llvm::FoldingSetNodeID ID;
935    FunctionTemplateSpecializationInfo::Profile(ID,
936                             TemplateArgs.getInnermost().getFlatArgumentList(),
937                                       TemplateArgs.getInnermost().flat_size(),
938                                                SemaRef.Context);
939
940    FunctionTemplateSpecializationInfo *Info
941      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
942                                                                   InsertPos);
943
944    // If we already have a function template specialization, return it.
945    if (Info)
946      return Info->Function;
947  }
948
949  bool isFriend;
950  if (FunctionTemplate)
951    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
952  else
953    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
954
955  bool MergeWithParentScope = (TemplateParams != 0) ||
956    !(isa<Decl>(Owner) &&
957      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
958  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
959
960  llvm::SmallVector<ParmVarDecl *, 4> Params;
961  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
962  TInfo = SubstFunctionType(D, Params);
963  if (!TInfo)
964    return 0;
965  QualType T = TInfo->getType();
966
967  NestedNameSpecifier *Qualifier = D->getQualifier();
968  if (Qualifier) {
969    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
970                                                 D->getQualifierRange(),
971                                                 TemplateArgs);
972    if (!Qualifier) return 0;
973  }
974
975  // If we're instantiating a local function declaration, put the result
976  // in the owner;  otherwise we need to find the instantiated context.
977  DeclContext *DC;
978  if (D->getDeclContext()->isFunctionOrMethod())
979    DC = Owner;
980  else if (isFriend && Qualifier) {
981    CXXScopeSpec SS;
982    SS.setScopeRep(Qualifier);
983    SS.setRange(D->getQualifierRange());
984    DC = SemaRef.computeDeclContext(SS);
985    if (!DC) return 0;
986  } else {
987    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
988                                         TemplateArgs);
989  }
990
991  FunctionDecl *Function =
992      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
993                           D->getDeclName(), T, TInfo,
994                           D->getStorageClass(),
995                           D->isInlineSpecified(), D->hasWrittenPrototype());
996
997  if (Qualifier)
998    Function->setQualifierInfo(Qualifier, D->getQualifierRange());
999
1000  DeclContext *LexicalDC = Owner;
1001  if (!isFriend && D->isOutOfLine()) {
1002    assert(D->getDeclContext()->isFileContext());
1003    LexicalDC = D->getDeclContext();
1004  }
1005
1006  Function->setLexicalDeclContext(LexicalDC);
1007
1008  // Attach the parameters
1009  for (unsigned P = 0; P < Params.size(); ++P)
1010    Params[P]->setOwningFunction(Function);
1011  Function->setParams(Params.data(), Params.size());
1012
1013  if (TemplateParams) {
1014    // Our resulting instantiation is actually a function template, since we
1015    // are substituting only the outer template parameters. For example, given
1016    //
1017    //   template<typename T>
1018    //   struct X {
1019    //     template<typename U> friend void f(T, U);
1020    //   };
1021    //
1022    //   X<int> x;
1023    //
1024    // We are instantiating the friend function template "f" within X<int>,
1025    // which means substituting int for T, but leaving "f" as a friend function
1026    // template.
1027    // Build the function template itself.
1028    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1029                                                    Function->getLocation(),
1030                                                    Function->getDeclName(),
1031                                                    TemplateParams, Function);
1032    Function->setDescribedFunctionTemplate(FunctionTemplate);
1033
1034    FunctionTemplate->setLexicalDeclContext(LexicalDC);
1035
1036    if (isFriend && D->isThisDeclarationADefinition()) {
1037      // TODO: should we remember this connection regardless of whether
1038      // the friend declaration provided a body?
1039      FunctionTemplate->setInstantiatedFromMemberTemplate(
1040                                           D->getDescribedFunctionTemplate());
1041    }
1042  } else if (FunctionTemplate) {
1043    // Record this function template specialization.
1044    Function->setFunctionTemplateSpecialization(FunctionTemplate,
1045                                                &TemplateArgs.getInnermost(),
1046                                                InsertPos);
1047  } else if (isFriend && D->isThisDeclarationADefinition()) {
1048    // TODO: should we remember this connection regardless of whether
1049    // the friend declaration provided a body?
1050    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1051  }
1052
1053  if (InitFunctionInstantiation(Function, D))
1054    Function->setInvalidDecl();
1055
1056  bool Redeclaration = false;
1057  bool OverloadableAttrRequired = false;
1058  bool isExplicitSpecialization = false;
1059
1060  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1061                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1062
1063  if (DependentFunctionTemplateSpecializationInfo *Info
1064        = D->getDependentSpecializationInfo()) {
1065    assert(isFriend && "non-friend has dependent specialization info?");
1066
1067    // This needs to be set now for future sanity.
1068    Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1069
1070    // Instantiate the explicit template arguments.
1071    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1072                                          Info->getRAngleLoc());
1073    for (unsigned I = 0, E = Info->getNumTemplateArgs(); I != E; ++I) {
1074      TemplateArgumentLoc Loc;
1075      if (SemaRef.Subst(Info->getTemplateArg(I), Loc, TemplateArgs))
1076        return 0;
1077
1078      ExplicitArgs.addArgument(Loc);
1079    }
1080
1081    // Map the candidate templates to their instantiations.
1082    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1083      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1084                                                Info->getTemplate(I),
1085                                                TemplateArgs);
1086      if (!Temp) return 0;
1087
1088      Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1089    }
1090
1091    if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1092                                                    &ExplicitArgs,
1093                                                    Previous))
1094      Function->setInvalidDecl();
1095
1096    isExplicitSpecialization = true;
1097
1098  } else if (TemplateParams || !FunctionTemplate) {
1099    // Look only into the namespace where the friend would be declared to
1100    // find a previous declaration. This is the innermost enclosing namespace,
1101    // as described in ActOnFriendFunctionDecl.
1102    SemaRef.LookupQualifiedName(Previous, DC);
1103
1104    // In C++, the previous declaration we find might be a tag type
1105    // (class or enum). In this case, the new declaration will hide the
1106    // tag type. Note that this does does not apply if we're declaring a
1107    // typedef (C++ [dcl.typedef]p4).
1108    if (Previous.isSingleTagDecl())
1109      Previous.clear();
1110  }
1111
1112  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1113                                   isExplicitSpecialization, Redeclaration,
1114                                   /*FIXME:*/OverloadableAttrRequired);
1115
1116  // If the original function was part of a friend declaration,
1117  // inherit its namespace state and add it to the owner.
1118  if (isFriend) {
1119    NamedDecl *ToFriendD = 0;
1120    NamedDecl *PrevDecl;
1121    if (TemplateParams) {
1122      ToFriendD = cast<NamedDecl>(FunctionTemplate);
1123      PrevDecl = FunctionTemplate->getPreviousDeclaration();
1124    } else {
1125      ToFriendD = Function;
1126      PrevDecl = Function->getPreviousDeclaration();
1127    }
1128    ToFriendD->setObjectOfFriendDecl(PrevDecl != NULL);
1129    DC->makeDeclVisibleInContext(ToFriendD, /*Recoverable=*/ false);
1130  }
1131
1132  return Function;
1133}
1134
1135Decl *
1136TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1137                                      TemplateParameterList *TemplateParams) {
1138  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1139  void *InsertPos = 0;
1140  if (FunctionTemplate && !TemplateParams) {
1141    // We are creating a function template specialization from a function
1142    // template. Check whether there is already a function template
1143    // specialization for this particular set of template arguments.
1144    llvm::FoldingSetNodeID ID;
1145    FunctionTemplateSpecializationInfo::Profile(ID,
1146                            TemplateArgs.getInnermost().getFlatArgumentList(),
1147                                      TemplateArgs.getInnermost().flat_size(),
1148                                                SemaRef.Context);
1149
1150    FunctionTemplateSpecializationInfo *Info
1151      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
1152                                                                   InsertPos);
1153
1154    // If we already have a function template specialization, return it.
1155    if (Info)
1156      return Info->Function;
1157  }
1158
1159  bool isFriend;
1160  if (FunctionTemplate)
1161    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1162  else
1163    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1164
1165  bool MergeWithParentScope = (TemplateParams != 0) ||
1166    !(isa<Decl>(Owner) &&
1167      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1168  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1169
1170  llvm::SmallVector<ParmVarDecl *, 4> Params;
1171  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1172  TInfo = SubstFunctionType(D, Params);
1173  if (!TInfo)
1174    return 0;
1175  QualType T = TInfo->getType();
1176
1177  NestedNameSpecifier *Qualifier = D->getQualifier();
1178  if (Qualifier) {
1179    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1180                                                 D->getQualifierRange(),
1181                                                 TemplateArgs);
1182    if (!Qualifier) return 0;
1183  }
1184
1185  DeclContext *DC = Owner;
1186  if (isFriend) {
1187    if (Qualifier) {
1188      CXXScopeSpec SS;
1189      SS.setScopeRep(Qualifier);
1190      SS.setRange(D->getQualifierRange());
1191      DC = SemaRef.computeDeclContext(SS);
1192    } else {
1193      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1194                                           D->getDeclContext(),
1195                                           TemplateArgs);
1196    }
1197    if (!DC) return 0;
1198  }
1199
1200  // Build the instantiated method declaration.
1201  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1202  CXXMethodDecl *Method = 0;
1203
1204  DeclarationName Name = D->getDeclName();
1205  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1206    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1207    Name = SemaRef.Context.DeclarationNames.getCXXConstructorName(
1208                                    SemaRef.Context.getCanonicalType(ClassTy));
1209    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1210                                        Constructor->getLocation(),
1211                                        Name, T, TInfo,
1212                                        Constructor->isExplicit(),
1213                                        Constructor->isInlineSpecified(), false);
1214  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1215    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1216    Name = SemaRef.Context.DeclarationNames.getCXXDestructorName(
1217                                   SemaRef.Context.getCanonicalType(ClassTy));
1218    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1219                                       Destructor->getLocation(), Name,
1220                                       T, Destructor->isInlineSpecified(), false);
1221  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1222    CanQualType ConvTy
1223      = SemaRef.Context.getCanonicalType(
1224                                      T->getAs<FunctionType>()->getResultType());
1225    Name = SemaRef.Context.DeclarationNames.getCXXConversionFunctionName(
1226                                                                      ConvTy);
1227    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1228                                       Conversion->getLocation(), Name,
1229                                       T, TInfo,
1230                                       Conversion->isInlineSpecified(),
1231                                       Conversion->isExplicit());
1232  } else {
1233    Method = CXXMethodDecl::Create(SemaRef.Context, Record, D->getLocation(),
1234                                   D->getDeclName(), T, TInfo,
1235                                   D->isStatic(), D->isInlineSpecified());
1236  }
1237
1238  if (Qualifier)
1239    Method->setQualifierInfo(Qualifier, D->getQualifierRange());
1240
1241  if (TemplateParams) {
1242    // Our resulting instantiation is actually a function template, since we
1243    // are substituting only the outer template parameters. For example, given
1244    //
1245    //   template<typename T>
1246    //   struct X {
1247    //     template<typename U> void f(T, U);
1248    //   };
1249    //
1250    //   X<int> x;
1251    //
1252    // We are instantiating the member template "f" within X<int>, which means
1253    // substituting int for T, but leaving "f" as a member function template.
1254    // Build the function template itself.
1255    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1256                                                    Method->getLocation(),
1257                                                    Method->getDeclName(),
1258                                                    TemplateParams, Method);
1259    if (isFriend) {
1260      FunctionTemplate->setLexicalDeclContext(Owner);
1261      FunctionTemplate->setObjectOfFriendDecl(true);
1262    } else if (D->isOutOfLine())
1263      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1264    Method->setDescribedFunctionTemplate(FunctionTemplate);
1265  } else if (FunctionTemplate) {
1266    // Record this function template specialization.
1267    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1268                                              &TemplateArgs.getInnermost(),
1269                                              InsertPos);
1270  } else if (!isFriend) {
1271    // Record that this is an instantiation of a member function.
1272    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1273  }
1274
1275  // If we are instantiating a member function defined
1276  // out-of-line, the instantiation will have the same lexical
1277  // context (which will be a namespace scope) as the template.
1278  if (isFriend) {
1279    Method->setLexicalDeclContext(Owner);
1280    Method->setObjectOfFriendDecl(true);
1281  } else if (D->isOutOfLine())
1282    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1283
1284  // Attach the parameters
1285  for (unsigned P = 0; P < Params.size(); ++P)
1286    Params[P]->setOwningFunction(Method);
1287  Method->setParams(Params.data(), Params.size());
1288
1289  if (InitMethodInstantiation(Method, D))
1290    Method->setInvalidDecl();
1291
1292  LookupResult Previous(SemaRef, Name, SourceLocation(),
1293                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1294
1295  if (!FunctionTemplate || TemplateParams || isFriend) {
1296    SemaRef.LookupQualifiedName(Previous, Record);
1297
1298    // In C++, the previous declaration we find might be a tag type
1299    // (class or enum). In this case, the new declaration will hide the
1300    // tag type. Note that this does does not apply if we're declaring a
1301    // typedef (C++ [dcl.typedef]p4).
1302    if (Previous.isSingleTagDecl())
1303      Previous.clear();
1304  }
1305
1306  bool Redeclaration = false;
1307  bool OverloadableAttrRequired = false;
1308  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1309                                   /*FIXME:*/OverloadableAttrRequired);
1310
1311  if (D->isPure())
1312    SemaRef.CheckPureMethod(Method, SourceRange());
1313
1314  Method->setAccess(D->getAccess());
1315
1316  if (FunctionTemplate) {
1317    // If there's a function template, let our caller handle it.
1318  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1319    // Don't hide a (potentially) valid declaration with an invalid one.
1320  } else {
1321    NamedDecl *DeclToAdd = (TemplateParams
1322                            ? cast<NamedDecl>(FunctionTemplate)
1323                            : Method);
1324    if (isFriend)
1325      Record->makeDeclVisibleInContext(DeclToAdd);
1326    else
1327      Owner->addDecl(DeclToAdd);
1328  }
1329
1330  return Method;
1331}
1332
1333Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1334  return VisitCXXMethodDecl(D);
1335}
1336
1337Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1338  return VisitCXXMethodDecl(D);
1339}
1340
1341Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1342  return VisitCXXMethodDecl(D);
1343}
1344
1345ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1346  QualType T;
1347  TypeSourceInfo *DI = D->getTypeSourceInfo();
1348  if (DI) {
1349    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1350                           D->getDeclName());
1351    if (DI) T = DI->getType();
1352  } else {
1353    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1354                          D->getDeclName());
1355    DI = 0;
1356  }
1357
1358  if (T.isNull())
1359    return 0;
1360
1361  T = SemaRef.adjustParameterType(T);
1362
1363  // Allocate the parameter
1364  ParmVarDecl *Param
1365    = ParmVarDecl::Create(SemaRef.Context,
1366                          SemaRef.Context.getTranslationUnitDecl(),
1367                          D->getLocation(),
1368                          D->getIdentifier(), T, DI, D->getStorageClass(), 0);
1369
1370  // Mark the default argument as being uninstantiated.
1371  if (D->hasUninstantiatedDefaultArg())
1372    Param->setUninstantiatedDefaultArg(D->getUninstantiatedDefaultArg());
1373  else if (Expr *Arg = D->getDefaultArg())
1374    Param->setUninstantiatedDefaultArg(Arg);
1375
1376  // Note: we don't try to instantiate function parameters until after
1377  // we've instantiated the function's type. Therefore, we don't have
1378  // to check for 'void' parameter types here.
1379  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1380  return Param;
1381}
1382
1383Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1384                                                    TemplateTypeParmDecl *D) {
1385  // TODO: don't always clone when decls are refcounted.
1386  const Type* T = D->getTypeForDecl();
1387  assert(T->isTemplateTypeParmType());
1388  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1389
1390  TemplateTypeParmDecl *Inst =
1391    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1392                                 TTPT->getDepth() - 1, TTPT->getIndex(),
1393                                 TTPT->getName(),
1394                                 D->wasDeclaredWithTypename(),
1395                                 D->isParameterPack());
1396
1397  if (D->hasDefaultArgument())
1398    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1399
1400  // Introduce this template parameter's instantiation into the instantiation
1401  // scope.
1402  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1403
1404  return Inst;
1405}
1406
1407Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1408                                                 NonTypeTemplateParmDecl *D) {
1409  // Substitute into the type of the non-type template parameter.
1410  QualType T;
1411  TypeSourceInfo *DI = D->getTypeSourceInfo();
1412  if (DI) {
1413    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1414                           D->getDeclName());
1415    if (DI) T = DI->getType();
1416  } else {
1417    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1418                          D->getDeclName());
1419    DI = 0;
1420  }
1421  if (T.isNull())
1422    return 0;
1423
1424  // Check that this type is acceptable for a non-type template parameter.
1425  bool Invalid = false;
1426  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1427  if (T.isNull()) {
1428    T = SemaRef.Context.IntTy;
1429    Invalid = true;
1430  }
1431
1432  NonTypeTemplateParmDecl *Param
1433    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1434                                      D->getDepth() - 1, D->getPosition(),
1435                                      D->getIdentifier(), T, DI);
1436  if (Invalid)
1437    Param->setInvalidDecl();
1438
1439  Param->setDefaultArgument(D->getDefaultArgument());
1440
1441  // Introduce this template parameter's instantiation into the instantiation
1442  // scope.
1443  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1444  return Param;
1445}
1446
1447Decl *
1448TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1449                                                  TemplateTemplateParmDecl *D) {
1450  // Instantiate the template parameter list of the template template parameter.
1451  TemplateParameterList *TempParams = D->getTemplateParameters();
1452  TemplateParameterList *InstParams;
1453  {
1454    // Perform the actual substitution of template parameters within a new,
1455    // local instantiation scope.
1456    Sema::LocalInstantiationScope Scope(SemaRef);
1457    InstParams = SubstTemplateParams(TempParams);
1458    if (!InstParams)
1459      return NULL;
1460  }
1461
1462  // Build the template template parameter.
1463  TemplateTemplateParmDecl *Param
1464    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1465                                       D->getDepth() - 1, D->getPosition(),
1466                                       D->getIdentifier(), InstParams);
1467  Param->setDefaultArgument(D->getDefaultArgument());
1468
1469  // Introduce this template parameter's instantiation into the instantiation
1470  // scope.
1471  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1472
1473  return Param;
1474}
1475
1476Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1477  // Using directives are never dependent, so they require no explicit
1478
1479  UsingDirectiveDecl *Inst
1480    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1481                                 D->getNamespaceKeyLocation(),
1482                                 D->getQualifierRange(), D->getQualifier(),
1483                                 D->getIdentLocation(),
1484                                 D->getNominatedNamespace(),
1485                                 D->getCommonAncestor());
1486  Owner->addDecl(Inst);
1487  return Inst;
1488}
1489
1490Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1491  // The nested name specifier is non-dependent, so no transformation
1492  // is required.
1493
1494  // We only need to do redeclaration lookups if we're in a class
1495  // scope (in fact, it's not really even possible in non-class
1496  // scopes).
1497  bool CheckRedeclaration = Owner->isRecord();
1498
1499  LookupResult Prev(SemaRef, D->getDeclName(), D->getLocation(),
1500                    Sema::LookupUsingDeclName, Sema::ForRedeclaration);
1501
1502  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1503                                       D->getLocation(),
1504                                       D->getNestedNameRange(),
1505                                       D->getUsingLocation(),
1506                                       D->getTargetNestedNameDecl(),
1507                                       D->getDeclName(),
1508                                       D->isTypeName());
1509
1510  CXXScopeSpec SS;
1511  SS.setScopeRep(D->getTargetNestedNameDecl());
1512  SS.setRange(D->getNestedNameRange());
1513
1514  if (CheckRedeclaration) {
1515    Prev.setHideTags(false);
1516    SemaRef.LookupQualifiedName(Prev, Owner);
1517
1518    // Check for invalid redeclarations.
1519    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1520                                            D->isTypeName(), SS,
1521                                            D->getLocation(), Prev))
1522      NewUD->setInvalidDecl();
1523
1524  }
1525
1526  if (!NewUD->isInvalidDecl() &&
1527      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1528                                      D->getLocation()))
1529    NewUD->setInvalidDecl();
1530
1531  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1532  NewUD->setAccess(D->getAccess());
1533  Owner->addDecl(NewUD);
1534
1535  // Don't process the shadow decls for an invalid decl.
1536  if (NewUD->isInvalidDecl())
1537    return NewUD;
1538
1539  bool isFunctionScope = Owner->isFunctionOrMethod();
1540
1541  // Process the shadow decls.
1542  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1543         I != E; ++I) {
1544    UsingShadowDecl *Shadow = *I;
1545    NamedDecl *InstTarget =
1546      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1547                                                   Shadow->getTargetDecl(),
1548                                                   TemplateArgs));
1549
1550    if (CheckRedeclaration &&
1551        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1552      continue;
1553
1554    UsingShadowDecl *InstShadow
1555      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1556    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1557
1558    if (isFunctionScope)
1559      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1560  }
1561
1562  return NewUD;
1563}
1564
1565Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1566  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1567  return 0;
1568}
1569
1570Decl * TemplateDeclInstantiator
1571    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1572  NestedNameSpecifier *NNS =
1573    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1574                                     D->getTargetNestedNameRange(),
1575                                     TemplateArgs);
1576  if (!NNS)
1577    return 0;
1578
1579  CXXScopeSpec SS;
1580  SS.setRange(D->getTargetNestedNameRange());
1581  SS.setScopeRep(NNS);
1582
1583  NamedDecl *UD =
1584    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1585                                  D->getUsingLoc(), SS, D->getLocation(),
1586                                  D->getDeclName(), 0,
1587                                  /*instantiation*/ true,
1588                                  /*typename*/ true, D->getTypenameLoc());
1589  if (UD)
1590    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1591
1592  return UD;
1593}
1594
1595Decl * TemplateDeclInstantiator
1596    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1597  NestedNameSpecifier *NNS =
1598    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1599                                     D->getTargetNestedNameRange(),
1600                                     TemplateArgs);
1601  if (!NNS)
1602    return 0;
1603
1604  CXXScopeSpec SS;
1605  SS.setRange(D->getTargetNestedNameRange());
1606  SS.setScopeRep(NNS);
1607
1608  NamedDecl *UD =
1609    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1610                                  D->getUsingLoc(), SS, D->getLocation(),
1611                                  D->getDeclName(), 0,
1612                                  /*instantiation*/ true,
1613                                  /*typename*/ false, SourceLocation());
1614  if (UD)
1615    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1616
1617  return UD;
1618}
1619
1620Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1621                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1622  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1623  if (D->isInvalidDecl())
1624    return 0;
1625
1626  return Instantiator.Visit(D);
1627}
1628
1629/// \brief Instantiates a nested template parameter list in the current
1630/// instantiation context.
1631///
1632/// \param L The parameter list to instantiate
1633///
1634/// \returns NULL if there was an error
1635TemplateParameterList *
1636TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1637  // Get errors for all the parameters before bailing out.
1638  bool Invalid = false;
1639
1640  unsigned N = L->size();
1641  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1642  ParamVector Params;
1643  Params.reserve(N);
1644  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1645       PI != PE; ++PI) {
1646    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1647    Params.push_back(D);
1648    Invalid = Invalid || !D || D->isInvalidDecl();
1649  }
1650
1651  // Clean up if we had an error.
1652  if (Invalid) {
1653    for (ParamVector::iterator PI = Params.begin(), PE = Params.end();
1654         PI != PE; ++PI)
1655      if (*PI)
1656        (*PI)->Destroy(SemaRef.Context);
1657    return NULL;
1658  }
1659
1660  TemplateParameterList *InstL
1661    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1662                                    L->getLAngleLoc(), &Params.front(), N,
1663                                    L->getRAngleLoc());
1664  return InstL;
1665}
1666
1667/// \brief Instantiate the declaration of a class template partial
1668/// specialization.
1669///
1670/// \param ClassTemplate the (instantiated) class template that is partially
1671// specialized by the instantiation of \p PartialSpec.
1672///
1673/// \param PartialSpec the (uninstantiated) class template partial
1674/// specialization that we are instantiating.
1675///
1676/// \returns true if there was an error, false otherwise.
1677bool
1678TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1679                                            ClassTemplateDecl *ClassTemplate,
1680                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1681  // Create a local instantiation scope for this class template partial
1682  // specialization, which will contain the instantiations of the template
1683  // parameters.
1684  Sema::LocalInstantiationScope Scope(SemaRef);
1685
1686  // Substitute into the template parameters of the class template partial
1687  // specialization.
1688  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1689  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1690  if (!InstParams)
1691    return true;
1692
1693  // Substitute into the template arguments of the class template partial
1694  // specialization.
1695  const TemplateArgumentLoc *PartialSpecTemplateArgs
1696    = PartialSpec->getTemplateArgsAsWritten();
1697  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1698
1699  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1700  for (unsigned I = 0; I != N; ++I) {
1701    TemplateArgumentLoc Loc;
1702    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1703      return true;
1704    InstTemplateArgs.addArgument(Loc);
1705  }
1706
1707
1708  // Check that the template argument list is well-formed for this
1709  // class template.
1710  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1711                                        InstTemplateArgs.size());
1712  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1713                                        PartialSpec->getLocation(),
1714                                        InstTemplateArgs,
1715                                        false,
1716                                        Converted))
1717    return true;
1718
1719  // Figure out where to insert this class template partial specialization
1720  // in the member template's set of class template partial specializations.
1721  llvm::FoldingSetNodeID ID;
1722  ClassTemplatePartialSpecializationDecl::Profile(ID,
1723                                                  Converted.getFlatArguments(),
1724                                                  Converted.flatSize(),
1725                                                  SemaRef.Context);
1726  void *InsertPos = 0;
1727  ClassTemplateSpecializationDecl *PrevDecl
1728    = ClassTemplate->getPartialSpecializations().FindNodeOrInsertPos(ID,
1729                                                                     InsertPos);
1730
1731  // Build the canonical type that describes the converted template
1732  // arguments of the class template partial specialization.
1733  QualType CanonType
1734    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1735                                                  Converted.getFlatArguments(),
1736                                                    Converted.flatSize());
1737
1738  // Build the fully-sugared type for this class template
1739  // specialization as the user wrote in the specialization
1740  // itself. This means that we'll pretty-print the type retrieved
1741  // from the specialization's declaration the way that the user
1742  // actually wrote the specialization, rather than formatting the
1743  // name based on the "canonical" representation used to store the
1744  // template arguments in the specialization.
1745  TypeSourceInfo *WrittenTy
1746    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1747                                                    TemplateName(ClassTemplate),
1748                                                    PartialSpec->getLocation(),
1749                                                    InstTemplateArgs,
1750                                                    CanonType);
1751
1752  if (PrevDecl) {
1753    // We've already seen a partial specialization with the same template
1754    // parameters and template arguments. This can happen, for example, when
1755    // substituting the outer template arguments ends up causing two
1756    // class template partial specializations of a member class template
1757    // to have identical forms, e.g.,
1758    //
1759    //   template<typename T, typename U>
1760    //   struct Outer {
1761    //     template<typename X, typename Y> struct Inner;
1762    //     template<typename Y> struct Inner<T, Y>;
1763    //     template<typename Y> struct Inner<U, Y>;
1764    //   };
1765    //
1766    //   Outer<int, int> outer; // error: the partial specializations of Inner
1767    //                          // have the same signature.
1768    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1769      << WrittenTy;
1770    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1771      << SemaRef.Context.getTypeDeclType(PrevDecl);
1772    return true;
1773  }
1774
1775
1776  // Create the class template partial specialization declaration.
1777  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1778    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context, Owner,
1779                                                     PartialSpec->getLocation(),
1780                                                     InstParams,
1781                                                     ClassTemplate,
1782                                                     Converted,
1783                                                     InstTemplateArgs,
1784                                                     CanonType,
1785                                                     0);
1786  // Substitute the nested name specifier, if any.
1787  if (SubstQualifier(PartialSpec, InstPartialSpec))
1788    return 0;
1789
1790  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1791  InstPartialSpec->setTypeAsWritten(WrittenTy);
1792
1793  // Add this partial specialization to the set of class template partial
1794  // specializations.
1795  ClassTemplate->getPartialSpecializations().InsertNode(InstPartialSpec,
1796                                                        InsertPos);
1797  return false;
1798}
1799
1800bool
1801Sema::CheckInstantiatedParams(llvm::SmallVectorImpl<ParmVarDecl*> &Params) {
1802  bool Invalid = false;
1803  for (unsigned i = 0, i_end = Params.size(); i != i_end; ++i)
1804    if (ParmVarDecl *PInst = Params[i]) {
1805      if (PInst->isInvalidDecl())
1806        Invalid = true;
1807      else if (PInst->getType()->isVoidType()) {
1808        Diag(PInst->getLocation(), diag::err_param_with_void_type);
1809        PInst->setInvalidDecl();
1810        Invalid = true;
1811      }
1812      else if (RequireNonAbstractType(PInst->getLocation(),
1813                                      PInst->getType(),
1814                                      diag::err_abstract_type_in_decl,
1815                                      Sema::AbstractParamType)) {
1816        PInst->setInvalidDecl();
1817        Invalid = true;
1818      }
1819    }
1820  return Invalid;
1821}
1822
1823TypeSourceInfo*
1824TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1825                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1826  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1827  assert(OldTInfo && "substituting function without type source info");
1828  assert(Params.empty() && "parameter vector is non-empty at start");
1829  TypeSourceInfo *NewTInfo = SemaRef.SubstType(OldTInfo, TemplateArgs,
1830                                               D->getTypeSpecStartLoc(),
1831                                               D->getDeclName());
1832  if (!NewTInfo)
1833    return 0;
1834
1835  // Get parameters from the new type info.
1836  TypeLoc NewTL = NewTInfo->getTypeLoc();
1837  FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1838  assert(NewProtoLoc && "Missing prototype?");
1839  for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i)
1840    Params.push_back(NewProtoLoc->getArg(i));
1841
1842  return NewTInfo;
1843}
1844
1845/// \brief Initializes the common fields of an instantiation function
1846/// declaration (New) from the corresponding fields of its template (Tmpl).
1847///
1848/// \returns true if there was an error
1849bool
1850TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1851                                                    FunctionDecl *Tmpl) {
1852  if (Tmpl->isDeleted())
1853    New->setDeleted();
1854
1855  // If we are performing substituting explicitly-specified template arguments
1856  // or deduced template arguments into a function template and we reach this
1857  // point, we are now past the point where SFINAE applies and have committed
1858  // to keeping the new function template specialization. We therefore
1859  // convert the active template instantiation for the function template
1860  // into a template instantiation for this specific function template
1861  // specialization, which is not a SFINAE context, so that we diagnose any
1862  // further errors in the declaration itself.
1863  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1864  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1865  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1866      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1867    if (FunctionTemplateDecl *FunTmpl
1868          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1869      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1870             "Deduction from the wrong function template?");
1871      (void) FunTmpl;
1872      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1873      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1874      --SemaRef.NonInstantiationEntries;
1875    }
1876  }
1877
1878  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1879  assert(Proto && "Function template without prototype?");
1880
1881  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1882      Proto->getNoReturnAttr()) {
1883    // The function has an exception specification or a "noreturn"
1884    // attribute. Substitute into each of the exception types.
1885    llvm::SmallVector<QualType, 4> Exceptions;
1886    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1887      // FIXME: Poor location information!
1888      QualType T
1889        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1890                            New->getLocation(), New->getDeclName());
1891      if (T.isNull() ||
1892          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1893        continue;
1894
1895      Exceptions.push_back(T);
1896    }
1897
1898    // Rebuild the function type
1899
1900    const FunctionProtoType *NewProto
1901      = New->getType()->getAs<FunctionProtoType>();
1902    assert(NewProto && "Template instantiation without function prototype?");
1903    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1904                                                 NewProto->arg_type_begin(),
1905                                                 NewProto->getNumArgs(),
1906                                                 NewProto->isVariadic(),
1907                                                 NewProto->getTypeQuals(),
1908                                                 Proto->hasExceptionSpec(),
1909                                                 Proto->hasAnyExceptionSpec(),
1910                                                 Exceptions.size(),
1911                                                 Exceptions.data(),
1912                                                 Proto->getExtInfo()));
1913  }
1914
1915  return false;
1916}
1917
1918/// \brief Initializes common fields of an instantiated method
1919/// declaration (New) from the corresponding fields of its template
1920/// (Tmpl).
1921///
1922/// \returns true if there was an error
1923bool
1924TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
1925                                                  CXXMethodDecl *Tmpl) {
1926  if (InitFunctionInstantiation(New, Tmpl))
1927    return true;
1928
1929  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
1930  New->setAccess(Tmpl->getAccess());
1931  if (Tmpl->isVirtualAsWritten())
1932    Record->setMethodAsVirtual(New);
1933
1934  // FIXME: attributes
1935  // FIXME: New needs a pointer to Tmpl
1936  return false;
1937}
1938
1939/// \brief Instantiate the definition of the given function from its
1940/// template.
1941///
1942/// \param PointOfInstantiation the point at which the instantiation was
1943/// required. Note that this is not precisely a "point of instantiation"
1944/// for the function, but it's close.
1945///
1946/// \param Function the already-instantiated declaration of a
1947/// function template specialization or member function of a class template
1948/// specialization.
1949///
1950/// \param Recursive if true, recursively instantiates any functions that
1951/// are required by this instantiation.
1952///
1953/// \param DefinitionRequired if true, then we are performing an explicit
1954/// instantiation where the body of the function is required. Complain if
1955/// there is no such body.
1956void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
1957                                         FunctionDecl *Function,
1958                                         bool Recursive,
1959                                         bool DefinitionRequired) {
1960  if (Function->isInvalidDecl())
1961    return;
1962
1963  assert(!Function->getBody() && "Already instantiated!");
1964
1965  // Never instantiate an explicit specialization.
1966  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
1967    return;
1968
1969  // Find the function body that we'll be substituting.
1970  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
1971  Stmt *Pattern = 0;
1972  if (PatternDecl)
1973    Pattern = PatternDecl->getBody(PatternDecl);
1974
1975  if (!Pattern) {
1976    if (DefinitionRequired) {
1977      if (Function->getPrimaryTemplate())
1978        Diag(PointOfInstantiation,
1979             diag::err_explicit_instantiation_undefined_func_template)
1980          << Function->getPrimaryTemplate();
1981      else
1982        Diag(PointOfInstantiation,
1983             diag::err_explicit_instantiation_undefined_member)
1984          << 1 << Function->getDeclName() << Function->getDeclContext();
1985
1986      if (PatternDecl)
1987        Diag(PatternDecl->getLocation(),
1988             diag::note_explicit_instantiation_here);
1989    }
1990
1991    return;
1992  }
1993
1994  // C++0x [temp.explicit]p9:
1995  //   Except for inline functions, other explicit instantiation declarations
1996  //   have the effect of suppressing the implicit instantiation of the entity
1997  //   to which they refer.
1998  if (Function->getTemplateSpecializationKind()
1999        == TSK_ExplicitInstantiationDeclaration &&
2000      !PatternDecl->isInlined())
2001    return;
2002
2003  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2004  if (Inst)
2005    return;
2006
2007  // If we're performing recursive template instantiation, create our own
2008  // queue of pending implicit instantiations that we will instantiate later,
2009  // while we're still within our own instantiation context.
2010  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2011  if (Recursive)
2012    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2013
2014  ActOnStartOfFunctionDef(0, DeclPtrTy::make(Function));
2015
2016  // Introduce a new scope where local variable instantiations will be
2017  // recorded, unless we're actually a member function within a local
2018  // class, in which case we need to merge our results with the parent
2019  // scope (of the enclosing function).
2020  bool MergeWithParentScope = false;
2021  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2022    MergeWithParentScope = Rec->isLocalClass();
2023
2024  LocalInstantiationScope Scope(*this, MergeWithParentScope);
2025
2026  // Introduce the instantiated function parameters into the local
2027  // instantiation scope.
2028  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I)
2029    Scope.InstantiatedLocal(PatternDecl->getParamDecl(I),
2030                            Function->getParamDecl(I));
2031
2032  // Enter the scope of this instantiation. We don't use
2033  // PushDeclContext because we don't have a scope.
2034  DeclContext *PreviousContext = CurContext;
2035  CurContext = Function;
2036
2037  MultiLevelTemplateArgumentList TemplateArgs =
2038    getTemplateInstantiationArgs(Function);
2039
2040  // If this is a constructor, instantiate the member initializers.
2041  if (const CXXConstructorDecl *Ctor =
2042        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2043    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2044                               TemplateArgs);
2045  }
2046
2047  // Instantiate the function body.
2048  OwningStmtResult Body = SubstStmt(Pattern, TemplateArgs);
2049
2050  if (Body.isInvalid())
2051    Function->setInvalidDecl();
2052
2053  ActOnFinishFunctionBody(DeclPtrTy::make(Function), move(Body),
2054                          /*IsInstantiation=*/true);
2055
2056  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2057
2058  CurContext = PreviousContext;
2059
2060  DeclGroupRef DG(Function);
2061  Consumer.HandleTopLevelDecl(DG);
2062
2063  // This class may have local implicit instantiations that need to be
2064  // instantiation within this scope.
2065  PerformPendingImplicitInstantiations(/*LocalOnly=*/true);
2066  Scope.Exit();
2067
2068  if (Recursive) {
2069    // Instantiate any pending implicit instantiations found during the
2070    // instantiation of this template.
2071    PerformPendingImplicitInstantiations();
2072
2073    // Restore the set of pending implicit instantiations.
2074    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2075  }
2076}
2077
2078/// \brief Instantiate the definition of the given variable from its
2079/// template.
2080///
2081/// \param PointOfInstantiation the point at which the instantiation was
2082/// required. Note that this is not precisely a "point of instantiation"
2083/// for the function, but it's close.
2084///
2085/// \param Var the already-instantiated declaration of a static member
2086/// variable of a class template specialization.
2087///
2088/// \param Recursive if true, recursively instantiates any functions that
2089/// are required by this instantiation.
2090///
2091/// \param DefinitionRequired if true, then we are performing an explicit
2092/// instantiation where an out-of-line definition of the member variable
2093/// is required. Complain if there is no such definition.
2094void Sema::InstantiateStaticDataMemberDefinition(
2095                                          SourceLocation PointOfInstantiation,
2096                                                 VarDecl *Var,
2097                                                 bool Recursive,
2098                                                 bool DefinitionRequired) {
2099  if (Var->isInvalidDecl())
2100    return;
2101
2102  // Find the out-of-line definition of this static data member.
2103  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2104  assert(Def && "This data member was not instantiated from a template?");
2105  assert(Def->isStaticDataMember() && "Not a static data member?");
2106  Def = Def->getOutOfLineDefinition();
2107
2108  if (!Def) {
2109    // We did not find an out-of-line definition of this static data member,
2110    // so we won't perform any instantiation. Rather, we rely on the user to
2111    // instantiate this definition (or provide a specialization for it) in
2112    // another translation unit.
2113    if (DefinitionRequired) {
2114      Def = Var->getInstantiatedFromStaticDataMember();
2115      Diag(PointOfInstantiation,
2116           diag::err_explicit_instantiation_undefined_member)
2117        << 2 << Var->getDeclName() << Var->getDeclContext();
2118      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2119    }
2120
2121    return;
2122  }
2123
2124  // Never instantiate an explicit specialization.
2125  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2126    return;
2127
2128  // C++0x [temp.explicit]p9:
2129  //   Except for inline functions, other explicit instantiation declarations
2130  //   have the effect of suppressing the implicit instantiation of the entity
2131  //   to which they refer.
2132  if (Var->getTemplateSpecializationKind()
2133        == TSK_ExplicitInstantiationDeclaration)
2134    return;
2135
2136  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2137  if (Inst)
2138    return;
2139
2140  // If we're performing recursive template instantiation, create our own
2141  // queue of pending implicit instantiations that we will instantiate later,
2142  // while we're still within our own instantiation context.
2143  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2144  if (Recursive)
2145    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2146
2147  // Enter the scope of this instantiation. We don't use
2148  // PushDeclContext because we don't have a scope.
2149  DeclContext *PreviousContext = CurContext;
2150  CurContext = Var->getDeclContext();
2151
2152  VarDecl *OldVar = Var;
2153  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2154                                          getTemplateInstantiationArgs(Var)));
2155  CurContext = PreviousContext;
2156
2157  if (Var) {
2158    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2159    assert(MSInfo && "Missing member specialization information?");
2160    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2161                                       MSInfo->getPointOfInstantiation());
2162    DeclGroupRef DG(Var);
2163    Consumer.HandleTopLevelDecl(DG);
2164  }
2165
2166  if (Recursive) {
2167    // Instantiate any pending implicit instantiations found during the
2168    // instantiation of this template.
2169    PerformPendingImplicitInstantiations();
2170
2171    // Restore the set of pending implicit instantiations.
2172    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2173  }
2174}
2175
2176void
2177Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2178                                 const CXXConstructorDecl *Tmpl,
2179                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2180
2181  llvm::SmallVector<MemInitTy*, 4> NewInits;
2182  bool AnyErrors = false;
2183
2184  // Instantiate all the initializers.
2185  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2186                                            InitsEnd = Tmpl->init_end();
2187       Inits != InitsEnd; ++Inits) {
2188    CXXBaseOrMemberInitializer *Init = *Inits;
2189
2190    SourceLocation LParenLoc, RParenLoc;
2191    ASTOwningVector<&ActionBase::DeleteExpr> NewArgs(*this);
2192    llvm::SmallVector<SourceLocation, 4> CommaLocs;
2193
2194    // Instantiate the initializer.
2195    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2196                               LParenLoc, CommaLocs, NewArgs, RParenLoc)) {
2197      AnyErrors = true;
2198      continue;
2199    }
2200
2201    MemInitResult NewInit;
2202    if (Init->isBaseInitializer()) {
2203      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2204                                            TemplateArgs,
2205                                            Init->getSourceLocation(),
2206                                            New->getDeclName());
2207      if (!BaseTInfo) {
2208        AnyErrors = true;
2209        New->setInvalidDecl();
2210        continue;
2211      }
2212
2213      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2214                                     (Expr **)NewArgs.data(),
2215                                     NewArgs.size(),
2216                                     Init->getLParenLoc(),
2217                                     Init->getRParenLoc(),
2218                                     New->getParent());
2219    } else if (Init->isMemberInitializer()) {
2220      FieldDecl *Member;
2221
2222      // Is this an anonymous union?
2223      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2224        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2225                                                      UnionInit, TemplateArgs));
2226      else
2227        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2228                                                      Init->getMember(),
2229                                                      TemplateArgs));
2230
2231      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2232                                       NewArgs.size(),
2233                                       Init->getSourceLocation(),
2234                                       Init->getLParenLoc(),
2235                                       Init->getRParenLoc());
2236    }
2237
2238    if (NewInit.isInvalid()) {
2239      AnyErrors = true;
2240      New->setInvalidDecl();
2241    } else {
2242      // FIXME: It would be nice if ASTOwningVector had a release function.
2243      NewArgs.take();
2244
2245      NewInits.push_back((MemInitTy *)NewInit.get());
2246    }
2247  }
2248
2249  // Assign all the initializers to the new constructor.
2250  ActOnMemInitializers(DeclPtrTy::make(New),
2251                       /*FIXME: ColonLoc */
2252                       SourceLocation(),
2253                       NewInits.data(), NewInits.size(),
2254                       AnyErrors);
2255}
2256
2257// TODO: this could be templated if the various decl types used the
2258// same method name.
2259static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2260                              ClassTemplateDecl *Instance) {
2261  Pattern = Pattern->getCanonicalDecl();
2262
2263  do {
2264    Instance = Instance->getCanonicalDecl();
2265    if (Pattern == Instance) return true;
2266    Instance = Instance->getInstantiatedFromMemberTemplate();
2267  } while (Instance);
2268
2269  return false;
2270}
2271
2272static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2273                              FunctionTemplateDecl *Instance) {
2274  Pattern = Pattern->getCanonicalDecl();
2275
2276  do {
2277    Instance = Instance->getCanonicalDecl();
2278    if (Pattern == Instance) return true;
2279    Instance = Instance->getInstantiatedFromMemberTemplate();
2280  } while (Instance);
2281
2282  return false;
2283}
2284
2285static bool
2286isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2287                  ClassTemplatePartialSpecializationDecl *Instance) {
2288  Pattern
2289    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2290  do {
2291    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2292                                                Instance->getCanonicalDecl());
2293    if (Pattern == Instance)
2294      return true;
2295    Instance = Instance->getInstantiatedFromMember();
2296  } while (Instance);
2297
2298  return false;
2299}
2300
2301static bool isInstantiationOf(CXXRecordDecl *Pattern,
2302                              CXXRecordDecl *Instance) {
2303  Pattern = Pattern->getCanonicalDecl();
2304
2305  do {
2306    Instance = Instance->getCanonicalDecl();
2307    if (Pattern == Instance) return true;
2308    Instance = Instance->getInstantiatedFromMemberClass();
2309  } while (Instance);
2310
2311  return false;
2312}
2313
2314static bool isInstantiationOf(FunctionDecl *Pattern,
2315                              FunctionDecl *Instance) {
2316  Pattern = Pattern->getCanonicalDecl();
2317
2318  do {
2319    Instance = Instance->getCanonicalDecl();
2320    if (Pattern == Instance) return true;
2321    Instance = Instance->getInstantiatedFromMemberFunction();
2322  } while (Instance);
2323
2324  return false;
2325}
2326
2327static bool isInstantiationOf(EnumDecl *Pattern,
2328                              EnumDecl *Instance) {
2329  Pattern = Pattern->getCanonicalDecl();
2330
2331  do {
2332    Instance = Instance->getCanonicalDecl();
2333    if (Pattern == Instance) return true;
2334    Instance = Instance->getInstantiatedFromMemberEnum();
2335  } while (Instance);
2336
2337  return false;
2338}
2339
2340static bool isInstantiationOf(UsingShadowDecl *Pattern,
2341                              UsingShadowDecl *Instance,
2342                              ASTContext &C) {
2343  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2344}
2345
2346static bool isInstantiationOf(UsingDecl *Pattern,
2347                              UsingDecl *Instance,
2348                              ASTContext &C) {
2349  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2350}
2351
2352static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2353                              UsingDecl *Instance,
2354                              ASTContext &C) {
2355  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2356}
2357
2358static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2359                              UsingDecl *Instance,
2360                              ASTContext &C) {
2361  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2362}
2363
2364static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2365                                              VarDecl *Instance) {
2366  assert(Instance->isStaticDataMember());
2367
2368  Pattern = Pattern->getCanonicalDecl();
2369
2370  do {
2371    Instance = Instance->getCanonicalDecl();
2372    if (Pattern == Instance) return true;
2373    Instance = Instance->getInstantiatedFromStaticDataMember();
2374  } while (Instance);
2375
2376  return false;
2377}
2378
2379// Other is the prospective instantiation
2380// D is the prospective pattern
2381static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2382  if (D->getKind() != Other->getKind()) {
2383    if (UnresolvedUsingTypenameDecl *UUD
2384          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2385      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2386        return isInstantiationOf(UUD, UD, Ctx);
2387      }
2388    }
2389
2390    if (UnresolvedUsingValueDecl *UUD
2391          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2392      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2393        return isInstantiationOf(UUD, UD, Ctx);
2394      }
2395    }
2396
2397    return false;
2398  }
2399
2400  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2401    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2402
2403  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2404    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2405
2406  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2407    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2408
2409  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2410    if (Var->isStaticDataMember())
2411      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2412
2413  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2414    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2415
2416  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2417    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2418
2419  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2420        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2421    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2422                             PartialSpec);
2423
2424  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2425    if (!Field->getDeclName()) {
2426      // This is an unnamed field.
2427      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2428        cast<FieldDecl>(D);
2429    }
2430  }
2431
2432  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2433    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2434
2435  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2436    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2437
2438  return D->getDeclName() && isa<NamedDecl>(Other) &&
2439    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2440}
2441
2442template<typename ForwardIterator>
2443static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2444                                      NamedDecl *D,
2445                                      ForwardIterator first,
2446                                      ForwardIterator last) {
2447  for (; first != last; ++first)
2448    if (isInstantiationOf(Ctx, D, *first))
2449      return cast<NamedDecl>(*first);
2450
2451  return 0;
2452}
2453
2454/// \brief Finds the instantiation of the given declaration context
2455/// within the current instantiation.
2456///
2457/// \returns NULL if there was an error
2458DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2459                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2460  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2461    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2462    return cast_or_null<DeclContext>(ID);
2463  } else return DC;
2464}
2465
2466/// \brief Find the instantiation of the given declaration within the
2467/// current instantiation.
2468///
2469/// This routine is intended to be used when \p D is a declaration
2470/// referenced from within a template, that needs to mapped into the
2471/// corresponding declaration within an instantiation. For example,
2472/// given:
2473///
2474/// \code
2475/// template<typename T>
2476/// struct X {
2477///   enum Kind {
2478///     KnownValue = sizeof(T)
2479///   };
2480///
2481///   bool getKind() const { return KnownValue; }
2482/// };
2483///
2484/// template struct X<int>;
2485/// \endcode
2486///
2487/// In the instantiation of X<int>::getKind(), we need to map the
2488/// EnumConstantDecl for KnownValue (which refers to
2489/// X<T>::<Kind>::KnownValue) to its instantiation
2490/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2491/// this mapping from within the instantiation of X<int>.
2492NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2493                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2494  DeclContext *ParentDC = D->getDeclContext();
2495  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2496      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2497      ParentDC->isFunctionOrMethod()) {
2498    // D is a local of some kind. Look into the map of local
2499    // declarations to their instantiations.
2500    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2501  }
2502
2503  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2504    if (!Record->isDependentContext())
2505      return D;
2506
2507    // If the RecordDecl is actually the injected-class-name or a
2508    // "templated" declaration for a class template, class template
2509    // partial specialization, or a member class of a class template,
2510    // substitute into the injected-class-name of the class template
2511    // or partial specialization to find the new DeclContext.
2512    QualType T;
2513    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2514
2515    if (ClassTemplate) {
2516      T = ClassTemplate->getInjectedClassNameSpecialization(Context);
2517    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2518                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2519      ClassTemplate = PartialSpec->getSpecializedTemplate();
2520
2521      // If we call SubstType with an InjectedClassNameType here we
2522      // can end up in an infinite loop.
2523      T = Context.getTypeDeclType(Record);
2524      assert(isa<InjectedClassNameType>(T) &&
2525             "type of partial specialization is not an InjectedClassNameType");
2526      T = cast<InjectedClassNameType>(T)->getUnderlyingType();
2527    }
2528
2529    if (!T.isNull()) {
2530      // Substitute into the injected-class-name to get the type
2531      // corresponding to the instantiation we want, which may also be
2532      // the current instantiation (if we're in a template
2533      // definition). This substitution should never fail, since we
2534      // know we can instantiate the injected-class-name or we
2535      // wouldn't have gotten to the injected-class-name!
2536
2537      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2538      // extra instantiation in the common case?
2539      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2540      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2541
2542      if (!T->isDependentType()) {
2543        assert(T->isRecordType() && "Instantiation must produce a record type");
2544        return T->getAs<RecordType>()->getDecl();
2545      }
2546
2547      // We are performing "partial" template instantiation to create
2548      // the member declarations for the members of a class template
2549      // specialization. Therefore, D is actually referring to something
2550      // in the current instantiation. Look through the current
2551      // context, which contains actual instantiations, to find the
2552      // instantiation of the "current instantiation" that D refers
2553      // to.
2554      bool SawNonDependentContext = false;
2555      for (DeclContext *DC = CurContext; !DC->isFileContext();
2556           DC = DC->getParent()) {
2557        if (ClassTemplateSpecializationDecl *Spec
2558                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2559          if (isInstantiationOf(ClassTemplate,
2560                                Spec->getSpecializedTemplate()))
2561            return Spec;
2562
2563        if (!DC->isDependentContext())
2564          SawNonDependentContext = true;
2565      }
2566
2567      // We're performing "instantiation" of a member of the current
2568      // instantiation while we are type-checking the
2569      // definition. Compute the declaration context and return that.
2570      assert(!SawNonDependentContext &&
2571             "No dependent context while instantiating record");
2572      DeclContext *DC = computeDeclContext(T);
2573      assert(DC &&
2574             "Unable to find declaration for the current instantiation");
2575      return cast<CXXRecordDecl>(DC);
2576    }
2577
2578    // Fall through to deal with other dependent record types (e.g.,
2579    // anonymous unions in class templates).
2580  }
2581
2582  if (!ParentDC->isDependentContext())
2583    return D;
2584
2585  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2586  if (!ParentDC)
2587    return 0;
2588
2589  if (ParentDC != D->getDeclContext()) {
2590    // We performed some kind of instantiation in the parent context,
2591    // so now we need to look into the instantiated parent context to
2592    // find the instantiation of the declaration D.
2593
2594    // If our context used to be dependent, we may need to instantiate
2595    // it before performing lookup into that context.
2596    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2597      if (!Spec->isDependentContext()) {
2598        QualType T = Context.getTypeDeclType(Spec);
2599        const RecordType *Tag = T->getAs<RecordType>();
2600        assert(Tag && "type of non-dependent record is not a RecordType");
2601        if (!Tag->isBeingDefined() &&
2602            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2603          return 0;
2604      }
2605    }
2606
2607    NamedDecl *Result = 0;
2608    if (D->getDeclName()) {
2609      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2610      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2611    } else {
2612      // Since we don't have a name for the entity we're looking for,
2613      // our only option is to walk through all of the declarations to
2614      // find that name. This will occur in a few cases:
2615      //
2616      //   - anonymous struct/union within a template
2617      //   - unnamed class/struct/union/enum within a template
2618      //
2619      // FIXME: Find a better way to find these instantiations!
2620      Result = findInstantiationOf(Context, D,
2621                                   ParentDC->decls_begin(),
2622                                   ParentDC->decls_end());
2623    }
2624
2625    // UsingShadowDecls can instantiate to nothing because of using hiding.
2626    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2627            cast<Decl>(ParentDC)->isInvalidDecl())
2628           && "Unable to find instantiation of declaration!");
2629
2630    D = Result;
2631  }
2632
2633  return D;
2634}
2635
2636/// \brief Performs template instantiation for all implicit template
2637/// instantiations we have seen until this point.
2638void Sema::PerformPendingImplicitInstantiations(bool LocalOnly) {
2639  while (!PendingLocalImplicitInstantiations.empty() ||
2640         (!LocalOnly && !PendingImplicitInstantiations.empty())) {
2641    PendingImplicitInstantiation Inst;
2642
2643    if (PendingLocalImplicitInstantiations.empty()) {
2644      Inst = PendingImplicitInstantiations.front();
2645      PendingImplicitInstantiations.pop_front();
2646    } else {
2647      Inst = PendingLocalImplicitInstantiations.front();
2648      PendingLocalImplicitInstantiations.pop_front();
2649    }
2650
2651    // Instantiate function definitions
2652    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2653      PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Function),
2654                                            Function->getLocation(), *this,
2655                                            Context.getSourceManager(),
2656                                           "instantiating function definition");
2657
2658      if (!Function->getBody())
2659        InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true);
2660      continue;
2661    }
2662
2663    // Instantiate static data member definitions.
2664    VarDecl *Var = cast<VarDecl>(Inst.first);
2665    assert(Var->isStaticDataMember() && "Not a static data member?");
2666
2667    // Don't try to instantiate declarations if the most recent redeclaration
2668    // is invalid.
2669    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2670      continue;
2671
2672    // Check if the most recent declaration has changed the specialization kind
2673    // and removed the need for implicit instantiation.
2674    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2675    case TSK_Undeclared:
2676      assert(false && "Cannot instantitiate an undeclared specialization.");
2677    case TSK_ExplicitInstantiationDeclaration:
2678    case TSK_ExplicitInstantiationDefinition:
2679    case TSK_ExplicitSpecialization:
2680      continue;  // No longer need implicit instantiation.
2681    case TSK_ImplicitInstantiation:
2682      break;
2683    }
2684
2685    PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Var),
2686                                          Var->getLocation(), *this,
2687                                          Context.getSourceManager(),
2688                                          "instantiating static data member "
2689                                          "definition");
2690
2691    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true);
2692  }
2693}
2694
2695void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2696                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2697  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2698         E = Pattern->ddiag_end(); I != E; ++I) {
2699    DependentDiagnostic *DD = *I;
2700
2701    switch (DD->getKind()) {
2702    case DependentDiagnostic::Access:
2703      HandleDependentAccessCheck(*DD, TemplateArgs);
2704      break;
2705    }
2706  }
2707}
2708