SemaTemplateInstantiateDecl.cpp revision 944c37abb8acd1e14e73176922ee351db6a0f62f 
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                                 D->getStorageClassAsWritten());
327  Var->setThreadSpecified(D->isThreadSpecified());
328  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
329  Var->setDeclaredInCondition(D->isDeclaredInCondition());
330
331  // Substitute the nested name specifier, if any.
332  if (SubstQualifier(D, Var))
333    return 0;
334
335  // If we are instantiating a static data member defined
336  // out-of-line, the instantiation will have the same lexical
337  // context (which will be a namespace scope) as the template.
338  if (D->isOutOfLine())
339    Var->setLexicalDeclContext(D->getLexicalDeclContext());
340
341  Var->setAccess(D->getAccess());
342
343  // FIXME: In theory, we could have a previous declaration for variables that
344  // are not static data members.
345  bool Redeclaration = false;
346  // FIXME: having to fake up a LookupResult is dumb.
347  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
348                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
349  if (D->isStaticDataMember())
350    SemaRef.LookupQualifiedName(Previous, Owner, false);
351  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
352
353  if (D->isOutOfLine()) {
354    D->getLexicalDeclContext()->addDecl(Var);
355    Owner->makeDeclVisibleInContext(Var);
356  } else {
357    Owner->addDecl(Var);
358  }
359
360  // Link instantiations of static data members back to the template from
361  // which they were instantiated.
362  if (Var->isStaticDataMember())
363    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
364                                                     TSK_ImplicitInstantiation);
365
366  if (Var->getAnyInitializer()) {
367    // We already have an initializer in the class.
368  } else if (D->getInit()) {
369    if (Var->isStaticDataMember() && !D->isOutOfLine())
370      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
371    else
372      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
373
374    // Instantiate the initializer.
375    SourceLocation LParenLoc, RParenLoc;
376    llvm::SmallVector<SourceLocation, 4> CommaLocs;
377    ASTOwningVector<&ActionBase::DeleteExpr> InitArgs(SemaRef);
378    if (!InstantiateInitializer(SemaRef, D->getInit(), TemplateArgs, LParenLoc,
379                                CommaLocs, InitArgs, RParenLoc)) {
380      // Attach the initializer to the declaration.
381      if (D->hasCXXDirectInitializer()) {
382        // Add the direct initializer to the declaration.
383        SemaRef.AddCXXDirectInitializerToDecl(Sema::DeclPtrTy::make(Var),
384                                              LParenLoc,
385                                              move_arg(InitArgs),
386                                              CommaLocs.data(),
387                                              RParenLoc);
388      } else if (InitArgs.size() == 1) {
389        Expr *Init = (Expr*)(InitArgs.take()[0]);
390        SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var),
391                                     SemaRef.Owned(Init),
392                                     false);
393      } else {
394        assert(InitArgs.size() == 0);
395        SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
396      }
397    } else {
398      // FIXME: Not too happy about invalidating the declaration
399      // because of a bogus initializer.
400      Var->setInvalidDecl();
401    }
402
403    SemaRef.PopExpressionEvaluationContext();
404  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
405    SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
406
407  return Var;
408}
409
410Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
411  bool Invalid = false;
412  TypeSourceInfo *DI = D->getTypeSourceInfo();
413  if (DI->getType()->isDependentType())  {
414    DI = SemaRef.SubstType(DI, TemplateArgs,
415                           D->getLocation(), D->getDeclName());
416    if (!DI) {
417      DI = D->getTypeSourceInfo();
418      Invalid = true;
419    } else if (DI->getType()->isFunctionType()) {
420      // C++ [temp.arg.type]p3:
421      //   If a declaration acquires a function type through a type
422      //   dependent on a template-parameter and this causes a
423      //   declaration that does not use the syntactic form of a
424      //   function declarator to have function type, the program is
425      //   ill-formed.
426      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
427        << DI->getType();
428      Invalid = true;
429    }
430  }
431
432  Expr *BitWidth = D->getBitWidth();
433  if (Invalid)
434    BitWidth = 0;
435  else if (BitWidth) {
436    // The bit-width expression is not potentially evaluated.
437    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
438
439    OwningExprResult InstantiatedBitWidth
440      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
441    if (InstantiatedBitWidth.isInvalid()) {
442      Invalid = true;
443      BitWidth = 0;
444    } else
445      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
446  }
447
448  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
449                                            DI->getType(), DI,
450                                            cast<RecordDecl>(Owner),
451                                            D->getLocation(),
452                                            D->isMutable(),
453                                            BitWidth,
454                                            D->getTypeSpecStartLoc(),
455                                            D->getAccess(),
456                                            0);
457  if (!Field) {
458    cast<Decl>(Owner)->setInvalidDecl();
459    return 0;
460  }
461
462  InstantiateAttrs(D, Field);
463
464  if (Invalid)
465    Field->setInvalidDecl();
466
467  if (!Field->getDeclName()) {
468    // Keep track of where this decl came from.
469    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
470  }
471
472  Field->setImplicit(D->isImplicit());
473  Field->setAccess(D->getAccess());
474  Owner->addDecl(Field);
475
476  return Field;
477}
478
479Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
480  // Handle friend type expressions by simply substituting template
481  // parameters into the pattern type and checking the result.
482  if (TypeSourceInfo *Ty = D->getFriendType()) {
483    TypeSourceInfo *InstTy =
484      SemaRef.SubstType(Ty, TemplateArgs,
485                        D->getLocation(), DeclarationName());
486    if (!InstTy)
487      return 0;
488
489    FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getFriendLoc(), InstTy);
490    if (!FD)
491      return 0;
492
493    FD->setAccess(AS_public);
494    Owner->addDecl(FD);
495    return FD;
496  }
497
498  NamedDecl *ND = D->getFriendDecl();
499  assert(ND && "friend decl must be a decl or a type!");
500
501  // All of the Visit implementations for the various potential friend
502  // declarations have to be carefully written to work for friend
503  // objects, with the most important detail being that the target
504  // decl should almost certainly not be placed in Owner.
505  Decl *NewND = Visit(ND);
506  if (!NewND) return 0;
507
508  FriendDecl *FD =
509    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
510                       cast<NamedDecl>(NewND), D->getFriendLoc());
511  FD->setAccess(AS_public);
512  Owner->addDecl(FD);
513  return FD;
514}
515
516Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
517  Expr *AssertExpr = D->getAssertExpr();
518
519  // The expression in a static assertion is not potentially evaluated.
520  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
521
522  OwningExprResult InstantiatedAssertExpr
523    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
524  if (InstantiatedAssertExpr.isInvalid())
525    return 0;
526
527  OwningExprResult Message(SemaRef, D->getMessage());
528  D->getMessage()->Retain();
529  Decl *StaticAssert
530    = SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
531                                           move(InstantiatedAssertExpr),
532                                           move(Message)).getAs<Decl>();
533  return StaticAssert;
534}
535
536Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
537  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
538                                    D->getLocation(), D->getIdentifier(),
539                                    D->getTagKeywordLoc(),
540                                    /*PrevDecl=*/0);
541  Enum->setInstantiationOfMemberEnum(D);
542  Enum->setAccess(D->getAccess());
543  if (SubstQualifier(D, Enum)) return 0;
544  Owner->addDecl(Enum);
545  Enum->startDefinition();
546
547  if (D->getDeclContext()->isFunctionOrMethod())
548    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
549
550  llvm::SmallVector<Sema::DeclPtrTy, 4> Enumerators;
551
552  EnumConstantDecl *LastEnumConst = 0;
553  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
554         ECEnd = D->enumerator_end();
555       EC != ECEnd; ++EC) {
556    // The specified value for the enumerator.
557    OwningExprResult Value = SemaRef.Owned((Expr *)0);
558    if (Expr *UninstValue = EC->getInitExpr()) {
559      // The enumerator's value expression is not potentially evaluated.
560      EnterExpressionEvaluationContext Unevaluated(SemaRef,
561                                                   Action::Unevaluated);
562
563      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
564    }
565
566    // Drop the initial value and continue.
567    bool isInvalid = false;
568    if (Value.isInvalid()) {
569      Value = SemaRef.Owned((Expr *)0);
570      isInvalid = true;
571    }
572
573    EnumConstantDecl *EnumConst
574      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
575                                  EC->getLocation(), EC->getIdentifier(),
576                                  move(Value));
577
578    if (isInvalid) {
579      if (EnumConst)
580        EnumConst->setInvalidDecl();
581      Enum->setInvalidDecl();
582    }
583
584    if (EnumConst) {
585      EnumConst->setAccess(Enum->getAccess());
586      Enum->addDecl(EnumConst);
587      Enumerators.push_back(Sema::DeclPtrTy::make(EnumConst));
588      LastEnumConst = EnumConst;
589
590      if (D->getDeclContext()->isFunctionOrMethod()) {
591        // If the enumeration is within a function or method, record the enum
592        // constant as a local.
593        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
594      }
595    }
596  }
597
598  // FIXME: Fixup LBraceLoc and RBraceLoc
599  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
600  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
601                        Sema::DeclPtrTy::make(Enum),
602                        &Enumerators[0], Enumerators.size(),
603                        0, 0);
604
605  return Enum;
606}
607
608Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
609  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
610  return 0;
611}
612
613namespace {
614  class SortDeclByLocation {
615    SourceManager &SourceMgr;
616
617  public:
618    explicit SortDeclByLocation(SourceManager &SourceMgr)
619      : SourceMgr(SourceMgr) { }
620
621    bool operator()(const Decl *X, const Decl *Y) const {
622      return SourceMgr.isBeforeInTranslationUnit(X->getLocation(),
623                                                 Y->getLocation());
624    }
625  };
626}
627
628Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
629  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
630
631  // Create a local instantiation scope for this class template, which
632  // will contain the instantiations of the template parameters.
633  Sema::LocalInstantiationScope Scope(SemaRef);
634  TemplateParameterList *TempParams = D->getTemplateParameters();
635  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
636  if (!InstParams)
637    return NULL;
638
639  CXXRecordDecl *Pattern = D->getTemplatedDecl();
640
641  // Instantiate the qualifier.  We have to do this first in case
642  // we're a friend declaration, because if we are then we need to put
643  // the new declaration in the appropriate context.
644  NestedNameSpecifier *Qualifier = Pattern->getQualifier();
645  if (Qualifier) {
646    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
647                                                 Pattern->getQualifierRange(),
648                                                 TemplateArgs);
649    if (!Qualifier) return 0;
650  }
651
652  CXXRecordDecl *PrevDecl = 0;
653  ClassTemplateDecl *PrevClassTemplate = 0;
654
655  // If this isn't a friend, then it's a member template, in which
656  // case we just want to build the instantiation in the
657  // specialization.  If it is a friend, we want to build it in
658  // the appropriate context.
659  DeclContext *DC = Owner;
660  if (isFriend) {
661    if (Qualifier) {
662      CXXScopeSpec SS;
663      SS.setScopeRep(Qualifier);
664      SS.setRange(Pattern->getQualifierRange());
665      DC = SemaRef.computeDeclContext(SS);
666      if (!DC) return 0;
667    } else {
668      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
669                                           Pattern->getDeclContext(),
670                                           TemplateArgs);
671    }
672
673    // Look for a previous declaration of the template in the owning
674    // context.
675    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
676                   Sema::LookupOrdinaryName, Sema::ForRedeclaration);
677    SemaRef.LookupQualifiedName(R, DC);
678
679    if (R.isSingleResult()) {
680      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
681      if (PrevClassTemplate)
682        PrevDecl = PrevClassTemplate->getTemplatedDecl();
683    }
684
685    if (!PrevClassTemplate && Qualifier) {
686      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
687        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
688        << Pattern->getQualifierRange();
689      return 0;
690    }
691
692    bool AdoptedPreviousTemplateParams = false;
693    if (PrevClassTemplate) {
694      bool Complain = true;
695
696      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
697      // template for struct std::tr1::__detail::_Map_base, where the
698      // template parameters of the friend declaration don't match the
699      // template parameters of the original declaration. In this one
700      // case, we don't complain about the ill-formed friend
701      // declaration.
702      if (isFriend && Pattern->getIdentifier() &&
703          Pattern->getIdentifier()->isStr("_Map_base") &&
704          DC->isNamespace() &&
705          cast<NamespaceDecl>(DC)->getIdentifier() &&
706          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
707        DeclContext *DCParent = DC->getParent();
708        if (DCParent->isNamespace() &&
709            cast<NamespaceDecl>(DCParent)->getIdentifier() &&
710            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
711          DeclContext *DCParent2 = DCParent->getParent();
712          if (DCParent2->isNamespace() &&
713              cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
714              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
715              DCParent2->getParent()->isTranslationUnit())
716            Complain = false;
717        }
718      }
719
720      TemplateParameterList *PrevParams
721        = PrevClassTemplate->getTemplateParameters();
722
723      // Make sure the parameter lists match.
724      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
725                                                  Complain,
726                                                  Sema::TPL_TemplateMatch)) {
727        if (Complain)
728          return 0;
729
730        AdoptedPreviousTemplateParams = true;
731        InstParams = PrevParams;
732      }
733
734      // Do some additional validation, then merge default arguments
735      // from the existing declarations.
736      if (!AdoptedPreviousTemplateParams &&
737          SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
738                                             Sema::TPC_ClassTemplate))
739        return 0;
740    }
741  }
742
743  CXXRecordDecl *RecordInst
744    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
745                            Pattern->getLocation(), Pattern->getIdentifier(),
746                            Pattern->getTagKeywordLoc(), PrevDecl,
747                            /*DelayTypeCreation=*/true);
748
749  if (Qualifier)
750    RecordInst->setQualifierInfo(Qualifier, Pattern->getQualifierRange());
751
752  ClassTemplateDecl *Inst
753    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
754                                D->getIdentifier(), InstParams, RecordInst,
755                                PrevClassTemplate);
756  RecordInst->setDescribedClassTemplate(Inst);
757
758  if (isFriend) {
759    if (PrevClassTemplate)
760      Inst->setAccess(PrevClassTemplate->getAccess());
761    else
762      Inst->setAccess(D->getAccess());
763
764    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
765    // TODO: do we want to track the instantiation progeny of this
766    // friend target decl?
767  } else {
768    Inst->setAccess(D->getAccess());
769    Inst->setInstantiatedFromMemberTemplate(D);
770  }
771
772  // Trigger creation of the type for the instantiation.
773  SemaRef.Context.getInjectedClassNameType(RecordInst,
774                  Inst->getInjectedClassNameSpecialization(SemaRef.Context));
775
776  // Finish handling of friends.
777  if (isFriend) {
778    DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
779    return Inst;
780  }
781
782  Owner->addDecl(Inst);
783
784  // First, we sort the partial specializations by location, so
785  // that we instantiate them in the order they were declared.
786  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
787  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
788         P = D->getPartialSpecializations().begin(),
789         PEnd = D->getPartialSpecializations().end();
790       P != PEnd; ++P)
791    PartialSpecs.push_back(&*P);
792  std::sort(PartialSpecs.begin(), PartialSpecs.end(),
793            SortDeclByLocation(SemaRef.SourceMgr));
794
795  // Instantiate all of the partial specializations of this member class
796  // template.
797  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
798    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
799
800  return Inst;
801}
802
803Decl *
804TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
805                                   ClassTemplatePartialSpecializationDecl *D) {
806  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
807
808  // Lookup the already-instantiated declaration in the instantiation
809  // of the class template and return that.
810  DeclContext::lookup_result Found
811    = Owner->lookup(ClassTemplate->getDeclName());
812  if (Found.first == Found.second)
813    return 0;
814
815  ClassTemplateDecl *InstClassTemplate
816    = dyn_cast<ClassTemplateDecl>(*Found.first);
817  if (!InstClassTemplate)
818    return 0;
819
820  Decl *DCanon = D->getCanonicalDecl();
821  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
822            P = InstClassTemplate->getPartialSpecializations().begin(),
823         PEnd = InstClassTemplate->getPartialSpecializations().end();
824       P != PEnd; ++P) {
825    if (P->getInstantiatedFromMember()->getCanonicalDecl() == DCanon)
826      return &*P;
827  }
828
829  return 0;
830}
831
832Decl *
833TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
834  // Create a local instantiation scope for this function template, which
835  // will contain the instantiations of the template parameters and then get
836  // merged with the local instantiation scope for the function template
837  // itself.
838  Sema::LocalInstantiationScope Scope(SemaRef);
839
840  TemplateParameterList *TempParams = D->getTemplateParameters();
841  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
842  if (!InstParams)
843    return NULL;
844
845  FunctionDecl *Instantiated = 0;
846  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
847    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
848                                                                 InstParams));
849  else
850    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
851                                                          D->getTemplatedDecl(),
852                                                                InstParams));
853
854  if (!Instantiated)
855    return 0;
856
857  Instantiated->setAccess(D->getAccess());
858
859  // Link the instantiated function template declaration to the function
860  // template from which it was instantiated.
861  FunctionTemplateDecl *InstTemplate
862    = Instantiated->getDescribedFunctionTemplate();
863  InstTemplate->setAccess(D->getAccess());
864  assert(InstTemplate &&
865         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
866
867  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
868
869  // Link the instantiation back to the pattern *unless* this is a
870  // non-definition friend declaration.
871  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
872      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
873    InstTemplate->setInstantiatedFromMemberTemplate(D);
874
875  // Make declarations visible in the appropriate context.
876  if (!isFriend)
877    Owner->addDecl(InstTemplate);
878
879  return InstTemplate;
880}
881
882Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
883  CXXRecordDecl *PrevDecl = 0;
884  if (D->isInjectedClassName())
885    PrevDecl = cast<CXXRecordDecl>(Owner);
886  else if (D->getPreviousDeclaration()) {
887    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
888                                                   D->getPreviousDeclaration(),
889                                                   TemplateArgs);
890    if (!Prev) return 0;
891    PrevDecl = cast<CXXRecordDecl>(Prev);
892  }
893
894  CXXRecordDecl *Record
895    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
896                            D->getLocation(), D->getIdentifier(),
897                            D->getTagKeywordLoc(), PrevDecl);
898
899  // Substitute the nested name specifier, if any.
900  if (SubstQualifier(D, Record))
901    return 0;
902
903  Record->setImplicit(D->isImplicit());
904  // FIXME: Check against AS_none is an ugly hack to work around the issue that
905  // the tag decls introduced by friend class declarations don't have an access
906  // specifier. Remove once this area of the code gets sorted out.
907  if (D->getAccess() != AS_none)
908    Record->setAccess(D->getAccess());
909  if (!D->isInjectedClassName())
910    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
911
912  // If the original function was part of a friend declaration,
913  // inherit its namespace state.
914  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
915    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
916
917  Record->setAnonymousStructOrUnion(D->isAnonymousStructOrUnion());
918
919  Owner->addDecl(Record);
920  return Record;
921}
922
923/// Normal class members are of more specific types and therefore
924/// don't make it here.  This function serves two purposes:
925///   1) instantiating function templates
926///   2) substituting friend declarations
927/// FIXME: preserve function definitions in case #2
928Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
929                                       TemplateParameterList *TemplateParams) {
930  // Check whether there is already a function template specialization for
931  // this declaration.
932  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
933  void *InsertPos = 0;
934  if (FunctionTemplate && !TemplateParams) {
935    llvm::FoldingSetNodeID ID;
936    FunctionTemplateSpecializationInfo::Profile(ID,
937                             TemplateArgs.getInnermost().getFlatArgumentList(),
938                                       TemplateArgs.getInnermost().flat_size(),
939                                                SemaRef.Context);
940
941    FunctionTemplateSpecializationInfo *Info
942      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
943                                                                   InsertPos);
944
945    // If we already have a function template specialization, return it.
946    if (Info)
947      return Info->Function;
948  }
949
950  bool isFriend;
951  if (FunctionTemplate)
952    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
953  else
954    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
955
956  bool MergeWithParentScope = (TemplateParams != 0) ||
957    !(isa<Decl>(Owner) &&
958      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
959  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
960
961  llvm::SmallVector<ParmVarDecl *, 4> Params;
962  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
963  TInfo = SubstFunctionType(D, Params);
964  if (!TInfo)
965    return 0;
966  QualType T = TInfo->getType();
967
968  NestedNameSpecifier *Qualifier = D->getQualifier();
969  if (Qualifier) {
970    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
971                                                 D->getQualifierRange(),
972                                                 TemplateArgs);
973    if (!Qualifier) return 0;
974  }
975
976  // If we're instantiating a local function declaration, put the result
977  // in the owner;  otherwise we need to find the instantiated context.
978  DeclContext *DC;
979  if (D->getDeclContext()->isFunctionOrMethod())
980    DC = Owner;
981  else if (isFriend && Qualifier) {
982    CXXScopeSpec SS;
983    SS.setScopeRep(Qualifier);
984    SS.setRange(D->getQualifierRange());
985    DC = SemaRef.computeDeclContext(SS);
986    if (!DC) return 0;
987  } else {
988    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
989                                         TemplateArgs);
990  }
991
992  FunctionDecl *Function =
993      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
994                           D->getDeclName(), T, TInfo,
995                           D->getStorageClass(), D->getStorageClassAsWritten(),
996                           D->isInlineSpecified(), D->hasWrittenPrototype());
997
998  if (Qualifier)
999    Function->setQualifierInfo(Qualifier, D->getQualifierRange());
1000
1001  DeclContext *LexicalDC = Owner;
1002  if (!isFriend && D->isOutOfLine()) {
1003    assert(D->getDeclContext()->isFileContext());
1004    LexicalDC = D->getDeclContext();
1005  }
1006
1007  Function->setLexicalDeclContext(LexicalDC);
1008
1009  // Attach the parameters
1010  for (unsigned P = 0; P < Params.size(); ++P)
1011    Params[P]->setOwningFunction(Function);
1012  Function->setParams(Params.data(), Params.size());
1013
1014  if (TemplateParams) {
1015    // Our resulting instantiation is actually a function template, since we
1016    // are substituting only the outer template parameters. For example, given
1017    //
1018    //   template<typename T>
1019    //   struct X {
1020    //     template<typename U> friend void f(T, U);
1021    //   };
1022    //
1023    //   X<int> x;
1024    //
1025    // We are instantiating the friend function template "f" within X<int>,
1026    // which means substituting int for T, but leaving "f" as a friend function
1027    // template.
1028    // Build the function template itself.
1029    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1030                                                    Function->getLocation(),
1031                                                    Function->getDeclName(),
1032                                                    TemplateParams, Function);
1033    Function->setDescribedFunctionTemplate(FunctionTemplate);
1034
1035    FunctionTemplate->setLexicalDeclContext(LexicalDC);
1036
1037    if (isFriend && D->isThisDeclarationADefinition()) {
1038      // TODO: should we remember this connection regardless of whether
1039      // the friend declaration provided a body?
1040      FunctionTemplate->setInstantiatedFromMemberTemplate(
1041                                           D->getDescribedFunctionTemplate());
1042    }
1043  } else if (FunctionTemplate) {
1044    // Record this function template specialization.
1045    Function->setFunctionTemplateSpecialization(FunctionTemplate,
1046                                                &TemplateArgs.getInnermost(),
1047                                                InsertPos);
1048  } else if (isFriend && D->isThisDeclarationADefinition()) {
1049    // TODO: should we remember this connection regardless of whether
1050    // the friend declaration provided a body?
1051    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1052  }
1053
1054  if (InitFunctionInstantiation(Function, D))
1055    Function->setInvalidDecl();
1056
1057  bool Redeclaration = false;
1058  bool OverloadableAttrRequired = false;
1059  bool isExplicitSpecialization = false;
1060
1061  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1062                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1063
1064  if (DependentFunctionTemplateSpecializationInfo *Info
1065        = D->getDependentSpecializationInfo()) {
1066    assert(isFriend && "non-friend has dependent specialization info?");
1067
1068    // This needs to be set now for future sanity.
1069    Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1070
1071    // Instantiate the explicit template arguments.
1072    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1073                                          Info->getRAngleLoc());
1074    for (unsigned I = 0, E = Info->getNumTemplateArgs(); I != E; ++I) {
1075      TemplateArgumentLoc Loc;
1076      if (SemaRef.Subst(Info->getTemplateArg(I), Loc, TemplateArgs))
1077        return 0;
1078
1079      ExplicitArgs.addArgument(Loc);
1080    }
1081
1082    // Map the candidate templates to their instantiations.
1083    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1084      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1085                                                Info->getTemplate(I),
1086                                                TemplateArgs);
1087      if (!Temp) return 0;
1088
1089      Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1090    }
1091
1092    if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1093                                                    &ExplicitArgs,
1094                                                    Previous))
1095      Function->setInvalidDecl();
1096
1097    isExplicitSpecialization = true;
1098
1099  } else if (TemplateParams || !FunctionTemplate) {
1100    // Look only into the namespace where the friend would be declared to
1101    // find a previous declaration. This is the innermost enclosing namespace,
1102    // as described in ActOnFriendFunctionDecl.
1103    SemaRef.LookupQualifiedName(Previous, DC);
1104
1105    // In C++, the previous declaration we find might be a tag type
1106    // (class or enum). In this case, the new declaration will hide the
1107    // tag type. Note that this does does not apply if we're declaring a
1108    // typedef (C++ [dcl.typedef]p4).
1109    if (Previous.isSingleTagDecl())
1110      Previous.clear();
1111  }
1112
1113  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1114                                   isExplicitSpecialization, Redeclaration,
1115                                   /*FIXME:*/OverloadableAttrRequired);
1116
1117  // If the original function was part of a friend declaration,
1118  // inherit its namespace state and add it to the owner.
1119  if (isFriend) {
1120    NamedDecl *ToFriendD = 0;
1121    NamedDecl *PrevDecl;
1122    if (TemplateParams) {
1123      ToFriendD = cast<NamedDecl>(FunctionTemplate);
1124      PrevDecl = FunctionTemplate->getPreviousDeclaration();
1125    } else {
1126      ToFriendD = Function;
1127      PrevDecl = Function->getPreviousDeclaration();
1128    }
1129    ToFriendD->setObjectOfFriendDecl(PrevDecl != NULL);
1130    DC->makeDeclVisibleInContext(ToFriendD, /*Recoverable=*/ false);
1131  }
1132
1133  return Function;
1134}
1135
1136Decl *
1137TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1138                                      TemplateParameterList *TemplateParams) {
1139  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1140  void *InsertPos = 0;
1141  if (FunctionTemplate && !TemplateParams) {
1142    // We are creating a function template specialization from a function
1143    // template. Check whether there is already a function template
1144    // specialization for this particular set of template arguments.
1145    llvm::FoldingSetNodeID ID;
1146    FunctionTemplateSpecializationInfo::Profile(ID,
1147                            TemplateArgs.getInnermost().getFlatArgumentList(),
1148                                      TemplateArgs.getInnermost().flat_size(),
1149                                                SemaRef.Context);
1150
1151    FunctionTemplateSpecializationInfo *Info
1152      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
1153                                                                   InsertPos);
1154
1155    // If we already have a function template specialization, return it.
1156    if (Info)
1157      return Info->Function;
1158  }
1159
1160  bool isFriend;
1161  if (FunctionTemplate)
1162    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1163  else
1164    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1165
1166  bool MergeWithParentScope = (TemplateParams != 0) ||
1167    !(isa<Decl>(Owner) &&
1168      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1169  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1170
1171  llvm::SmallVector<ParmVarDecl *, 4> Params;
1172  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1173  TInfo = SubstFunctionType(D, Params);
1174  if (!TInfo)
1175    return 0;
1176  QualType T = TInfo->getType();
1177
1178  NestedNameSpecifier *Qualifier = D->getQualifier();
1179  if (Qualifier) {
1180    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1181                                                 D->getQualifierRange(),
1182                                                 TemplateArgs);
1183    if (!Qualifier) return 0;
1184  }
1185
1186  DeclContext *DC = Owner;
1187  if (isFriend) {
1188    if (Qualifier) {
1189      CXXScopeSpec SS;
1190      SS.setScopeRep(Qualifier);
1191      SS.setRange(D->getQualifierRange());
1192      DC = SemaRef.computeDeclContext(SS);
1193    } else {
1194      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1195                                           D->getDeclContext(),
1196                                           TemplateArgs);
1197    }
1198    if (!DC) return 0;
1199  }
1200
1201  // Build the instantiated method declaration.
1202  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1203  CXXMethodDecl *Method = 0;
1204
1205  DeclarationName Name = D->getDeclName();
1206  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1207    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1208    Name = SemaRef.Context.DeclarationNames.getCXXConstructorName(
1209                                    SemaRef.Context.getCanonicalType(ClassTy));
1210    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1211                                        Constructor->getLocation(),
1212                                        Name, T, TInfo,
1213                                        Constructor->isExplicit(),
1214                                        Constructor->isInlineSpecified(),
1215                                        false);
1216  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1217    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1218    Name = SemaRef.Context.DeclarationNames.getCXXDestructorName(
1219                                   SemaRef.Context.getCanonicalType(ClassTy));
1220    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1221                                       Destructor->getLocation(), Name,
1222                                       T, Destructor->isInlineSpecified(),
1223                                       false);
1224  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1225    CanQualType ConvTy
1226      = SemaRef.Context.getCanonicalType(
1227                                      T->getAs<FunctionType>()->getResultType());
1228    Name = SemaRef.Context.DeclarationNames.getCXXConversionFunctionName(
1229                                                                      ConvTy);
1230    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1231                                       Conversion->getLocation(), Name,
1232                                       T, TInfo,
1233                                       Conversion->isInlineSpecified(),
1234                                       Conversion->isExplicit());
1235  } else {
1236    Method = CXXMethodDecl::Create(SemaRef.Context, Record, D->getLocation(),
1237                                   D->getDeclName(), T, TInfo,
1238                                   D->isStatic(),
1239                                   D->getStorageClassAsWritten(),
1240                                   D->isInlineSpecified());
1241  }
1242
1243  if (Qualifier)
1244    Method->setQualifierInfo(Qualifier, D->getQualifierRange());
1245
1246  if (TemplateParams) {
1247    // Our resulting instantiation is actually a function template, since we
1248    // are substituting only the outer template parameters. For example, given
1249    //
1250    //   template<typename T>
1251    //   struct X {
1252    //     template<typename U> void f(T, U);
1253    //   };
1254    //
1255    //   X<int> x;
1256    //
1257    // We are instantiating the member template "f" within X<int>, which means
1258    // substituting int for T, but leaving "f" as a member function template.
1259    // Build the function template itself.
1260    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1261                                                    Method->getLocation(),
1262                                                    Method->getDeclName(),
1263                                                    TemplateParams, Method);
1264    if (isFriend) {
1265      FunctionTemplate->setLexicalDeclContext(Owner);
1266      FunctionTemplate->setObjectOfFriendDecl(true);
1267    } else if (D->isOutOfLine())
1268      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1269    Method->setDescribedFunctionTemplate(FunctionTemplate);
1270  } else if (FunctionTemplate) {
1271    // Record this function template specialization.
1272    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1273                                              &TemplateArgs.getInnermost(),
1274                                              InsertPos);
1275  } else if (!isFriend) {
1276    // Record that this is an instantiation of a member function.
1277    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1278  }
1279
1280  // If we are instantiating a member function defined
1281  // out-of-line, the instantiation will have the same lexical
1282  // context (which will be a namespace scope) as the template.
1283  if (isFriend) {
1284    Method->setLexicalDeclContext(Owner);
1285    Method->setObjectOfFriendDecl(true);
1286  } else if (D->isOutOfLine())
1287    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1288
1289  // Attach the parameters
1290  for (unsigned P = 0; P < Params.size(); ++P)
1291    Params[P]->setOwningFunction(Method);
1292  Method->setParams(Params.data(), Params.size());
1293
1294  if (InitMethodInstantiation(Method, D))
1295    Method->setInvalidDecl();
1296
1297  LookupResult Previous(SemaRef, Name, SourceLocation(),
1298                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1299
1300  if (!FunctionTemplate || TemplateParams || isFriend) {
1301    SemaRef.LookupQualifiedName(Previous, Record);
1302
1303    // In C++, the previous declaration we find might be a tag type
1304    // (class or enum). In this case, the new declaration will hide the
1305    // tag type. Note that this does does not apply if we're declaring a
1306    // typedef (C++ [dcl.typedef]p4).
1307    if (Previous.isSingleTagDecl())
1308      Previous.clear();
1309  }
1310
1311  bool Redeclaration = false;
1312  bool OverloadableAttrRequired = false;
1313  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1314                                   /*FIXME:*/OverloadableAttrRequired);
1315
1316  if (D->isPure())
1317    SemaRef.CheckPureMethod(Method, SourceRange());
1318
1319  Method->setAccess(D->getAccess());
1320
1321  if (FunctionTemplate) {
1322    // If there's a function template, let our caller handle it.
1323  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1324    // Don't hide a (potentially) valid declaration with an invalid one.
1325  } else {
1326    NamedDecl *DeclToAdd = (TemplateParams
1327                            ? cast<NamedDecl>(FunctionTemplate)
1328                            : Method);
1329    if (isFriend)
1330      Record->makeDeclVisibleInContext(DeclToAdd);
1331    else
1332      Owner->addDecl(DeclToAdd);
1333  }
1334
1335  return Method;
1336}
1337
1338Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1339  return VisitCXXMethodDecl(D);
1340}
1341
1342Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1343  return VisitCXXMethodDecl(D);
1344}
1345
1346Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1347  return VisitCXXMethodDecl(D);
1348}
1349
1350ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1351  return SemaRef.SubstParmVarDecl(D, TemplateArgs);
1352}
1353
1354Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1355                                                    TemplateTypeParmDecl *D) {
1356  // TODO: don't always clone when decls are refcounted.
1357  const Type* T = D->getTypeForDecl();
1358  assert(T->isTemplateTypeParmType());
1359  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1360
1361  TemplateTypeParmDecl *Inst =
1362    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1363                                 TTPT->getDepth() - 1, TTPT->getIndex(),
1364                                 TTPT->getName(),
1365                                 D->wasDeclaredWithTypename(),
1366                                 D->isParameterPack());
1367
1368  if (D->hasDefaultArgument())
1369    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1370
1371  // Introduce this template parameter's instantiation into the instantiation
1372  // scope.
1373  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1374
1375  return Inst;
1376}
1377
1378Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1379                                                 NonTypeTemplateParmDecl *D) {
1380  // Substitute into the type of the non-type template parameter.
1381  QualType T;
1382  TypeSourceInfo *DI = D->getTypeSourceInfo();
1383  if (DI) {
1384    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1385                           D->getDeclName());
1386    if (DI) T = DI->getType();
1387  } else {
1388    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1389                          D->getDeclName());
1390    DI = 0;
1391  }
1392  if (T.isNull())
1393    return 0;
1394
1395  // Check that this type is acceptable for a non-type template parameter.
1396  bool Invalid = false;
1397  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1398  if (T.isNull()) {
1399    T = SemaRef.Context.IntTy;
1400    Invalid = true;
1401  }
1402
1403  NonTypeTemplateParmDecl *Param
1404    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1405                                      D->getDepth() - 1, D->getPosition(),
1406                                      D->getIdentifier(), T, DI);
1407  if (Invalid)
1408    Param->setInvalidDecl();
1409
1410  Param->setDefaultArgument(D->getDefaultArgument());
1411
1412  // Introduce this template parameter's instantiation into the instantiation
1413  // scope.
1414  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1415  return Param;
1416}
1417
1418Decl *
1419TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1420                                                  TemplateTemplateParmDecl *D) {
1421  // Instantiate the template parameter list of the template template parameter.
1422  TemplateParameterList *TempParams = D->getTemplateParameters();
1423  TemplateParameterList *InstParams;
1424  {
1425    // Perform the actual substitution of template parameters within a new,
1426    // local instantiation scope.
1427    Sema::LocalInstantiationScope Scope(SemaRef);
1428    InstParams = SubstTemplateParams(TempParams);
1429    if (!InstParams)
1430      return NULL;
1431  }
1432
1433  // Build the template template parameter.
1434  TemplateTemplateParmDecl *Param
1435    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1436                                       D->getDepth() - 1, D->getPosition(),
1437                                       D->getIdentifier(), InstParams);
1438  Param->setDefaultArgument(D->getDefaultArgument());
1439
1440  // Introduce this template parameter's instantiation into the instantiation
1441  // scope.
1442  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1443
1444  return Param;
1445}
1446
1447Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1448  // Using directives are never dependent, so they require no explicit
1449
1450  UsingDirectiveDecl *Inst
1451    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1452                                 D->getNamespaceKeyLocation(),
1453                                 D->getQualifierRange(), D->getQualifier(),
1454                                 D->getIdentLocation(),
1455                                 D->getNominatedNamespace(),
1456                                 D->getCommonAncestor());
1457  Owner->addDecl(Inst);
1458  return Inst;
1459}
1460
1461Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1462  // The nested name specifier is non-dependent, so no transformation
1463  // is required.
1464
1465  // We only need to do redeclaration lookups if we're in a class
1466  // scope (in fact, it's not really even possible in non-class
1467  // scopes).
1468  bool CheckRedeclaration = Owner->isRecord();
1469
1470  LookupResult Prev(SemaRef, D->getDeclName(), D->getLocation(),
1471                    Sema::LookupUsingDeclName, Sema::ForRedeclaration);
1472
1473  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1474                                       D->getLocation(),
1475                                       D->getNestedNameRange(),
1476                                       D->getUsingLocation(),
1477                                       D->getTargetNestedNameDecl(),
1478                                       D->getDeclName(),
1479                                       D->isTypeName());
1480
1481  CXXScopeSpec SS;
1482  SS.setScopeRep(D->getTargetNestedNameDecl());
1483  SS.setRange(D->getNestedNameRange());
1484
1485  if (CheckRedeclaration) {
1486    Prev.setHideTags(false);
1487    SemaRef.LookupQualifiedName(Prev, Owner);
1488
1489    // Check for invalid redeclarations.
1490    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1491                                            D->isTypeName(), SS,
1492                                            D->getLocation(), Prev))
1493      NewUD->setInvalidDecl();
1494
1495  }
1496
1497  if (!NewUD->isInvalidDecl() &&
1498      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1499                                      D->getLocation()))
1500    NewUD->setInvalidDecl();
1501
1502  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1503  NewUD->setAccess(D->getAccess());
1504  Owner->addDecl(NewUD);
1505
1506  // Don't process the shadow decls for an invalid decl.
1507  if (NewUD->isInvalidDecl())
1508    return NewUD;
1509
1510  bool isFunctionScope = Owner->isFunctionOrMethod();
1511
1512  // Process the shadow decls.
1513  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1514         I != E; ++I) {
1515    UsingShadowDecl *Shadow = *I;
1516    NamedDecl *InstTarget =
1517      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1518                                                   Shadow->getTargetDecl(),
1519                                                   TemplateArgs));
1520
1521    if (CheckRedeclaration &&
1522        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1523      continue;
1524
1525    UsingShadowDecl *InstShadow
1526      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1527    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1528
1529    if (isFunctionScope)
1530      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1531  }
1532
1533  return NewUD;
1534}
1535
1536Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1537  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1538  return 0;
1539}
1540
1541Decl * TemplateDeclInstantiator
1542    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1543  NestedNameSpecifier *NNS =
1544    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1545                                     D->getTargetNestedNameRange(),
1546                                     TemplateArgs);
1547  if (!NNS)
1548    return 0;
1549
1550  CXXScopeSpec SS;
1551  SS.setRange(D->getTargetNestedNameRange());
1552  SS.setScopeRep(NNS);
1553
1554  NamedDecl *UD =
1555    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1556                                  D->getUsingLoc(), SS, D->getLocation(),
1557                                  D->getDeclName(), 0,
1558                                  /*instantiation*/ true,
1559                                  /*typename*/ true, D->getTypenameLoc());
1560  if (UD)
1561    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1562
1563  return UD;
1564}
1565
1566Decl * TemplateDeclInstantiator
1567    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1568  NestedNameSpecifier *NNS =
1569    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1570                                     D->getTargetNestedNameRange(),
1571                                     TemplateArgs);
1572  if (!NNS)
1573    return 0;
1574
1575  CXXScopeSpec SS;
1576  SS.setRange(D->getTargetNestedNameRange());
1577  SS.setScopeRep(NNS);
1578
1579  NamedDecl *UD =
1580    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1581                                  D->getUsingLoc(), SS, D->getLocation(),
1582                                  D->getDeclName(), 0,
1583                                  /*instantiation*/ true,
1584                                  /*typename*/ false, SourceLocation());
1585  if (UD)
1586    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1587
1588  return UD;
1589}
1590
1591Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1592                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1593  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1594  if (D->isInvalidDecl())
1595    return 0;
1596
1597  return Instantiator.Visit(D);
1598}
1599
1600/// \brief Instantiates a nested template parameter list in the current
1601/// instantiation context.
1602///
1603/// \param L The parameter list to instantiate
1604///
1605/// \returns NULL if there was an error
1606TemplateParameterList *
1607TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1608  // Get errors for all the parameters before bailing out.
1609  bool Invalid = false;
1610
1611  unsigned N = L->size();
1612  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1613  ParamVector Params;
1614  Params.reserve(N);
1615  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1616       PI != PE; ++PI) {
1617    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1618    Params.push_back(D);
1619    Invalid = Invalid || !D || D->isInvalidDecl();
1620  }
1621
1622  // Clean up if we had an error.
1623  if (Invalid) {
1624    for (ParamVector::iterator PI = Params.begin(), PE = Params.end();
1625         PI != PE; ++PI)
1626      if (*PI)
1627        (*PI)->Destroy(SemaRef.Context);
1628    return NULL;
1629  }
1630
1631  TemplateParameterList *InstL
1632    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1633                                    L->getLAngleLoc(), &Params.front(), N,
1634                                    L->getRAngleLoc());
1635  return InstL;
1636}
1637
1638/// \brief Instantiate the declaration of a class template partial
1639/// specialization.
1640///
1641/// \param ClassTemplate the (instantiated) class template that is partially
1642// specialized by the instantiation of \p PartialSpec.
1643///
1644/// \param PartialSpec the (uninstantiated) class template partial
1645/// specialization that we are instantiating.
1646///
1647/// \returns true if there was an error, false otherwise.
1648bool
1649TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1650                                            ClassTemplateDecl *ClassTemplate,
1651                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1652  // Create a local instantiation scope for this class template partial
1653  // specialization, which will contain the instantiations of the template
1654  // parameters.
1655  Sema::LocalInstantiationScope Scope(SemaRef);
1656
1657  // Substitute into the template parameters of the class template partial
1658  // specialization.
1659  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1660  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1661  if (!InstParams)
1662    return true;
1663
1664  // Substitute into the template arguments of the class template partial
1665  // specialization.
1666  const TemplateArgumentLoc *PartialSpecTemplateArgs
1667    = PartialSpec->getTemplateArgsAsWritten();
1668  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1669
1670  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1671  for (unsigned I = 0; I != N; ++I) {
1672    TemplateArgumentLoc Loc;
1673    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1674      return true;
1675    InstTemplateArgs.addArgument(Loc);
1676  }
1677
1678
1679  // Check that the template argument list is well-formed for this
1680  // class template.
1681  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1682                                        InstTemplateArgs.size());
1683  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1684                                        PartialSpec->getLocation(),
1685                                        InstTemplateArgs,
1686                                        false,
1687                                        Converted))
1688    return true;
1689
1690  // Figure out where to insert this class template partial specialization
1691  // in the member template's set of class template partial specializations.
1692  llvm::FoldingSetNodeID ID;
1693  ClassTemplatePartialSpecializationDecl::Profile(ID,
1694                                                  Converted.getFlatArguments(),
1695                                                  Converted.flatSize(),
1696                                                  SemaRef.Context);
1697  void *InsertPos = 0;
1698  ClassTemplateSpecializationDecl *PrevDecl
1699    = ClassTemplate->getPartialSpecializations().FindNodeOrInsertPos(ID,
1700                                                                     InsertPos);
1701
1702  // Build the canonical type that describes the converted template
1703  // arguments of the class template partial specialization.
1704  QualType CanonType
1705    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1706                                                  Converted.getFlatArguments(),
1707                                                    Converted.flatSize());
1708
1709  // Build the fully-sugared type for this class template
1710  // specialization as the user wrote in the specialization
1711  // itself. This means that we'll pretty-print the type retrieved
1712  // from the specialization's declaration the way that the user
1713  // actually wrote the specialization, rather than formatting the
1714  // name based on the "canonical" representation used to store the
1715  // template arguments in the specialization.
1716  TypeSourceInfo *WrittenTy
1717    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1718                                                    TemplateName(ClassTemplate),
1719                                                    PartialSpec->getLocation(),
1720                                                    InstTemplateArgs,
1721                                                    CanonType);
1722
1723  if (PrevDecl) {
1724    // We've already seen a partial specialization with the same template
1725    // parameters and template arguments. This can happen, for example, when
1726    // substituting the outer template arguments ends up causing two
1727    // class template partial specializations of a member class template
1728    // to have identical forms, e.g.,
1729    //
1730    //   template<typename T, typename U>
1731    //   struct Outer {
1732    //     template<typename X, typename Y> struct Inner;
1733    //     template<typename Y> struct Inner<T, Y>;
1734    //     template<typename Y> struct Inner<U, Y>;
1735    //   };
1736    //
1737    //   Outer<int, int> outer; // error: the partial specializations of Inner
1738    //                          // have the same signature.
1739    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1740      << WrittenTy;
1741    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1742      << SemaRef.Context.getTypeDeclType(PrevDecl);
1743    return true;
1744  }
1745
1746
1747  // Create the class template partial specialization declaration.
1748  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1749    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context, Owner,
1750                                                     PartialSpec->getLocation(),
1751                                                     InstParams,
1752                                                     ClassTemplate,
1753                                                     Converted,
1754                                                     InstTemplateArgs,
1755                                                     CanonType,
1756                                                     0);
1757  // Substitute the nested name specifier, if any.
1758  if (SubstQualifier(PartialSpec, InstPartialSpec))
1759    return 0;
1760
1761  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1762  InstPartialSpec->setTypeAsWritten(WrittenTy);
1763
1764  // Add this partial specialization to the set of class template partial
1765  // specializations.
1766  ClassTemplate->getPartialSpecializations().InsertNode(InstPartialSpec,
1767                                                        InsertPos);
1768  return false;
1769}
1770
1771TypeSourceInfo*
1772TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1773                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1774  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1775  assert(OldTInfo && "substituting function without type source info");
1776  assert(Params.empty() && "parameter vector is non-empty at start");
1777  TypeSourceInfo *NewTInfo
1778    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
1779                                    D->getTypeSpecStartLoc(),
1780                                    D->getDeclName());
1781  if (!NewTInfo)
1782    return 0;
1783
1784  if (NewTInfo != OldTInfo) {
1785    // Get parameters from the new type info.
1786    TypeLoc NewTL = NewTInfo->getTypeLoc();
1787    FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1788    assert(NewProtoLoc && "Missing prototype?");
1789    for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i)
1790      Params.push_back(NewProtoLoc->getArg(i));
1791  } else {
1792    // The function type itself was not dependent and therefore no
1793    // substitution occurred. However, we still need to instantiate
1794    // the function parameters themselves.
1795    TypeLoc OldTL = OldTInfo->getTypeLoc();
1796    FunctionProtoTypeLoc *OldProtoLoc = cast<FunctionProtoTypeLoc>(&OldTL);
1797    for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
1798      ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
1799      if (!Parm)
1800        return 0;
1801      Params.push_back(Parm);
1802    }
1803  }
1804  return NewTInfo;
1805}
1806
1807/// \brief Initializes the common fields of an instantiation function
1808/// declaration (New) from the corresponding fields of its template (Tmpl).
1809///
1810/// \returns true if there was an error
1811bool
1812TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1813                                                    FunctionDecl *Tmpl) {
1814  if (Tmpl->isDeleted())
1815    New->setDeleted();
1816
1817  // If we are performing substituting explicitly-specified template arguments
1818  // or deduced template arguments into a function template and we reach this
1819  // point, we are now past the point where SFINAE applies and have committed
1820  // to keeping the new function template specialization. We therefore
1821  // convert the active template instantiation for the function template
1822  // into a template instantiation for this specific function template
1823  // specialization, which is not a SFINAE context, so that we diagnose any
1824  // further errors in the declaration itself.
1825  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1826  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1827  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1828      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1829    if (FunctionTemplateDecl *FunTmpl
1830          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1831      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1832             "Deduction from the wrong function template?");
1833      (void) FunTmpl;
1834      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1835      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1836      --SemaRef.NonInstantiationEntries;
1837    }
1838  }
1839
1840  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1841  assert(Proto && "Function template without prototype?");
1842
1843  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1844      Proto->getNoReturnAttr()) {
1845    // The function has an exception specification or a "noreturn"
1846    // attribute. Substitute into each of the exception types.
1847    llvm::SmallVector<QualType, 4> Exceptions;
1848    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1849      // FIXME: Poor location information!
1850      QualType T
1851        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1852                            New->getLocation(), New->getDeclName());
1853      if (T.isNull() ||
1854          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1855        continue;
1856
1857      Exceptions.push_back(T);
1858    }
1859
1860    // Rebuild the function type
1861
1862    const FunctionProtoType *NewProto
1863      = New->getType()->getAs<FunctionProtoType>();
1864    assert(NewProto && "Template instantiation without function prototype?");
1865    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1866                                                 NewProto->arg_type_begin(),
1867                                                 NewProto->getNumArgs(),
1868                                                 NewProto->isVariadic(),
1869                                                 NewProto->getTypeQuals(),
1870                                                 Proto->hasExceptionSpec(),
1871                                                 Proto->hasAnyExceptionSpec(),
1872                                                 Exceptions.size(),
1873                                                 Exceptions.data(),
1874                                                 Proto->getExtInfo()));
1875  }
1876
1877  return false;
1878}
1879
1880/// \brief Initializes common fields of an instantiated method
1881/// declaration (New) from the corresponding fields of its template
1882/// (Tmpl).
1883///
1884/// \returns true if there was an error
1885bool
1886TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
1887                                                  CXXMethodDecl *Tmpl) {
1888  if (InitFunctionInstantiation(New, Tmpl))
1889    return true;
1890
1891  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
1892  New->setAccess(Tmpl->getAccess());
1893  if (Tmpl->isVirtualAsWritten())
1894    Record->setMethodAsVirtual(New);
1895
1896  // FIXME: attributes
1897  // FIXME: New needs a pointer to Tmpl
1898  return false;
1899}
1900
1901/// \brief Instantiate the definition of the given function from its
1902/// template.
1903///
1904/// \param PointOfInstantiation the point at which the instantiation was
1905/// required. Note that this is not precisely a "point of instantiation"
1906/// for the function, but it's close.
1907///
1908/// \param Function the already-instantiated declaration of a
1909/// function template specialization or member function of a class template
1910/// specialization.
1911///
1912/// \param Recursive if true, recursively instantiates any functions that
1913/// are required by this instantiation.
1914///
1915/// \param DefinitionRequired if true, then we are performing an explicit
1916/// instantiation where the body of the function is required. Complain if
1917/// there is no such body.
1918void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
1919                                         FunctionDecl *Function,
1920                                         bool Recursive,
1921                                         bool DefinitionRequired) {
1922  if (Function->isInvalidDecl())
1923    return;
1924
1925  assert(!Function->getBody() && "Already instantiated!");
1926
1927  // Never instantiate an explicit specialization.
1928  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
1929    return;
1930
1931  // Find the function body that we'll be substituting.
1932  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
1933  Stmt *Pattern = 0;
1934  if (PatternDecl)
1935    Pattern = PatternDecl->getBody(PatternDecl);
1936
1937  if (!Pattern) {
1938    if (DefinitionRequired) {
1939      if (Function->getPrimaryTemplate())
1940        Diag(PointOfInstantiation,
1941             diag::err_explicit_instantiation_undefined_func_template)
1942          << Function->getPrimaryTemplate();
1943      else
1944        Diag(PointOfInstantiation,
1945             diag::err_explicit_instantiation_undefined_member)
1946          << 1 << Function->getDeclName() << Function->getDeclContext();
1947
1948      if (PatternDecl)
1949        Diag(PatternDecl->getLocation(),
1950             diag::note_explicit_instantiation_here);
1951    }
1952
1953    return;
1954  }
1955
1956  // C++0x [temp.explicit]p9:
1957  //   Except for inline functions, other explicit instantiation declarations
1958  //   have the effect of suppressing the implicit instantiation of the entity
1959  //   to which they refer.
1960  if (Function->getTemplateSpecializationKind()
1961        == TSK_ExplicitInstantiationDeclaration &&
1962      !PatternDecl->isInlined())
1963    return;
1964
1965  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
1966  if (Inst)
1967    return;
1968
1969  // If we're performing recursive template instantiation, create our own
1970  // queue of pending implicit instantiations that we will instantiate later,
1971  // while we're still within our own instantiation context.
1972  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
1973  if (Recursive)
1974    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1975
1976  ActOnStartOfFunctionDef(0, DeclPtrTy::make(Function));
1977
1978  // Introduce a new scope where local variable instantiations will be
1979  // recorded, unless we're actually a member function within a local
1980  // class, in which case we need to merge our results with the parent
1981  // scope (of the enclosing function).
1982  bool MergeWithParentScope = false;
1983  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
1984    MergeWithParentScope = Rec->isLocalClass();
1985
1986  LocalInstantiationScope Scope(*this, MergeWithParentScope);
1987
1988  // Introduce the instantiated function parameters into the local
1989  // instantiation scope.
1990  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I)
1991    Scope.InstantiatedLocal(PatternDecl->getParamDecl(I),
1992                            Function->getParamDecl(I));
1993
1994  // Enter the scope of this instantiation. We don't use
1995  // PushDeclContext because we don't have a scope.
1996  DeclContext *PreviousContext = CurContext;
1997  CurContext = Function;
1998
1999  MultiLevelTemplateArgumentList TemplateArgs =
2000    getTemplateInstantiationArgs(Function);
2001
2002  // If this is a constructor, instantiate the member initializers.
2003  if (const CXXConstructorDecl *Ctor =
2004        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2005    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2006                               TemplateArgs);
2007  }
2008
2009  // Instantiate the function body.
2010  OwningStmtResult Body = SubstStmt(Pattern, TemplateArgs);
2011
2012  if (Body.isInvalid())
2013    Function->setInvalidDecl();
2014
2015  ActOnFinishFunctionBody(DeclPtrTy::make(Function), move(Body),
2016                          /*IsInstantiation=*/true);
2017
2018  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2019
2020  CurContext = PreviousContext;
2021
2022  DeclGroupRef DG(Function);
2023  Consumer.HandleTopLevelDecl(DG);
2024
2025  // This class may have local implicit instantiations that need to be
2026  // instantiation within this scope.
2027  PerformPendingImplicitInstantiations(/*LocalOnly=*/true);
2028  Scope.Exit();
2029
2030  if (Recursive) {
2031    // Instantiate any pending implicit instantiations found during the
2032    // instantiation of this template.
2033    PerformPendingImplicitInstantiations();
2034
2035    // Restore the set of pending implicit instantiations.
2036    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2037  }
2038}
2039
2040/// \brief Instantiate the definition of the given variable from its
2041/// template.
2042///
2043/// \param PointOfInstantiation the point at which the instantiation was
2044/// required. Note that this is not precisely a "point of instantiation"
2045/// for the function, but it's close.
2046///
2047/// \param Var the already-instantiated declaration of a static member
2048/// variable of a class template specialization.
2049///
2050/// \param Recursive if true, recursively instantiates any functions that
2051/// are required by this instantiation.
2052///
2053/// \param DefinitionRequired if true, then we are performing an explicit
2054/// instantiation where an out-of-line definition of the member variable
2055/// is required. Complain if there is no such definition.
2056void Sema::InstantiateStaticDataMemberDefinition(
2057                                          SourceLocation PointOfInstantiation,
2058                                                 VarDecl *Var,
2059                                                 bool Recursive,
2060                                                 bool DefinitionRequired) {
2061  if (Var->isInvalidDecl())
2062    return;
2063
2064  // Find the out-of-line definition of this static data member.
2065  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2066  assert(Def && "This data member was not instantiated from a template?");
2067  assert(Def->isStaticDataMember() && "Not a static data member?");
2068  Def = Def->getOutOfLineDefinition();
2069
2070  if (!Def) {
2071    // We did not find an out-of-line definition of this static data member,
2072    // so we won't perform any instantiation. Rather, we rely on the user to
2073    // instantiate this definition (or provide a specialization for it) in
2074    // another translation unit.
2075    if (DefinitionRequired) {
2076      Def = Var->getInstantiatedFromStaticDataMember();
2077      Diag(PointOfInstantiation,
2078           diag::err_explicit_instantiation_undefined_member)
2079        << 2 << Var->getDeclName() << Var->getDeclContext();
2080      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2081    }
2082
2083    return;
2084  }
2085
2086  // Never instantiate an explicit specialization.
2087  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2088    return;
2089
2090  // C++0x [temp.explicit]p9:
2091  //   Except for inline functions, other explicit instantiation declarations
2092  //   have the effect of suppressing the implicit instantiation of the entity
2093  //   to which they refer.
2094  if (Var->getTemplateSpecializationKind()
2095        == TSK_ExplicitInstantiationDeclaration)
2096    return;
2097
2098  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2099  if (Inst)
2100    return;
2101
2102  // If we're performing recursive template instantiation, create our own
2103  // queue of pending implicit instantiations that we will instantiate later,
2104  // while we're still within our own instantiation context.
2105  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2106  if (Recursive)
2107    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2108
2109  // Enter the scope of this instantiation. We don't use
2110  // PushDeclContext because we don't have a scope.
2111  DeclContext *PreviousContext = CurContext;
2112  CurContext = Var->getDeclContext();
2113
2114  VarDecl *OldVar = Var;
2115  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2116                                          getTemplateInstantiationArgs(Var)));
2117  CurContext = PreviousContext;
2118
2119  if (Var) {
2120    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2121    assert(MSInfo && "Missing member specialization information?");
2122    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2123                                       MSInfo->getPointOfInstantiation());
2124    DeclGroupRef DG(Var);
2125    Consumer.HandleTopLevelDecl(DG);
2126  }
2127
2128  if (Recursive) {
2129    // Instantiate any pending implicit instantiations found during the
2130    // instantiation of this template.
2131    PerformPendingImplicitInstantiations();
2132
2133    // Restore the set of pending implicit instantiations.
2134    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2135  }
2136}
2137
2138void
2139Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2140                                 const CXXConstructorDecl *Tmpl,
2141                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2142
2143  llvm::SmallVector<MemInitTy*, 4> NewInits;
2144  bool AnyErrors = false;
2145
2146  // Instantiate all the initializers.
2147  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2148                                            InitsEnd = Tmpl->init_end();
2149       Inits != InitsEnd; ++Inits) {
2150    CXXBaseOrMemberInitializer *Init = *Inits;
2151
2152    SourceLocation LParenLoc, RParenLoc;
2153    ASTOwningVector<&ActionBase::DeleteExpr> NewArgs(*this);
2154    llvm::SmallVector<SourceLocation, 4> CommaLocs;
2155
2156    // Instantiate the initializer.
2157    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2158                               LParenLoc, CommaLocs, NewArgs, RParenLoc)) {
2159      AnyErrors = true;
2160      continue;
2161    }
2162
2163    MemInitResult NewInit;
2164    if (Init->isBaseInitializer()) {
2165      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2166                                            TemplateArgs,
2167                                            Init->getSourceLocation(),
2168                                            New->getDeclName());
2169      if (!BaseTInfo) {
2170        AnyErrors = true;
2171        New->setInvalidDecl();
2172        continue;
2173      }
2174
2175      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2176                                     (Expr **)NewArgs.data(),
2177                                     NewArgs.size(),
2178                                     Init->getLParenLoc(),
2179                                     Init->getRParenLoc(),
2180                                     New->getParent());
2181    } else if (Init->isMemberInitializer()) {
2182      FieldDecl *Member;
2183
2184      // Is this an anonymous union?
2185      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2186        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2187                                                      UnionInit, TemplateArgs));
2188      else
2189        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2190                                                      Init->getMember(),
2191                                                      TemplateArgs));
2192
2193      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2194                                       NewArgs.size(),
2195                                       Init->getSourceLocation(),
2196                                       Init->getLParenLoc(),
2197                                       Init->getRParenLoc());
2198    }
2199
2200    if (NewInit.isInvalid()) {
2201      AnyErrors = true;
2202      New->setInvalidDecl();
2203    } else {
2204      // FIXME: It would be nice if ASTOwningVector had a release function.
2205      NewArgs.take();
2206
2207      NewInits.push_back((MemInitTy *)NewInit.get());
2208    }
2209  }
2210
2211  // Assign all the initializers to the new constructor.
2212  ActOnMemInitializers(DeclPtrTy::make(New),
2213                       /*FIXME: ColonLoc */
2214                       SourceLocation(),
2215                       NewInits.data(), NewInits.size(),
2216                       AnyErrors);
2217}
2218
2219// TODO: this could be templated if the various decl types used the
2220// same method name.
2221static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2222                              ClassTemplateDecl *Instance) {
2223  Pattern = Pattern->getCanonicalDecl();
2224
2225  do {
2226    Instance = Instance->getCanonicalDecl();
2227    if (Pattern == Instance) return true;
2228    Instance = Instance->getInstantiatedFromMemberTemplate();
2229  } while (Instance);
2230
2231  return false;
2232}
2233
2234static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2235                              FunctionTemplateDecl *Instance) {
2236  Pattern = Pattern->getCanonicalDecl();
2237
2238  do {
2239    Instance = Instance->getCanonicalDecl();
2240    if (Pattern == Instance) return true;
2241    Instance = Instance->getInstantiatedFromMemberTemplate();
2242  } while (Instance);
2243
2244  return false;
2245}
2246
2247static bool
2248isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2249                  ClassTemplatePartialSpecializationDecl *Instance) {
2250  Pattern
2251    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2252  do {
2253    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2254                                                Instance->getCanonicalDecl());
2255    if (Pattern == Instance)
2256      return true;
2257    Instance = Instance->getInstantiatedFromMember();
2258  } while (Instance);
2259
2260  return false;
2261}
2262
2263static bool isInstantiationOf(CXXRecordDecl *Pattern,
2264                              CXXRecordDecl *Instance) {
2265  Pattern = Pattern->getCanonicalDecl();
2266
2267  do {
2268    Instance = Instance->getCanonicalDecl();
2269    if (Pattern == Instance) return true;
2270    Instance = Instance->getInstantiatedFromMemberClass();
2271  } while (Instance);
2272
2273  return false;
2274}
2275
2276static bool isInstantiationOf(FunctionDecl *Pattern,
2277                              FunctionDecl *Instance) {
2278  Pattern = Pattern->getCanonicalDecl();
2279
2280  do {
2281    Instance = Instance->getCanonicalDecl();
2282    if (Pattern == Instance) return true;
2283    Instance = Instance->getInstantiatedFromMemberFunction();
2284  } while (Instance);
2285
2286  return false;
2287}
2288
2289static bool isInstantiationOf(EnumDecl *Pattern,
2290                              EnumDecl *Instance) {
2291  Pattern = Pattern->getCanonicalDecl();
2292
2293  do {
2294    Instance = Instance->getCanonicalDecl();
2295    if (Pattern == Instance) return true;
2296    Instance = Instance->getInstantiatedFromMemberEnum();
2297  } while (Instance);
2298
2299  return false;
2300}
2301
2302static bool isInstantiationOf(UsingShadowDecl *Pattern,
2303                              UsingShadowDecl *Instance,
2304                              ASTContext &C) {
2305  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2306}
2307
2308static bool isInstantiationOf(UsingDecl *Pattern,
2309                              UsingDecl *Instance,
2310                              ASTContext &C) {
2311  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2312}
2313
2314static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2315                              UsingDecl *Instance,
2316                              ASTContext &C) {
2317  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2318}
2319
2320static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2321                              UsingDecl *Instance,
2322                              ASTContext &C) {
2323  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2324}
2325
2326static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2327                                              VarDecl *Instance) {
2328  assert(Instance->isStaticDataMember());
2329
2330  Pattern = Pattern->getCanonicalDecl();
2331
2332  do {
2333    Instance = Instance->getCanonicalDecl();
2334    if (Pattern == Instance) return true;
2335    Instance = Instance->getInstantiatedFromStaticDataMember();
2336  } while (Instance);
2337
2338  return false;
2339}
2340
2341// Other is the prospective instantiation
2342// D is the prospective pattern
2343static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2344  if (D->getKind() != Other->getKind()) {
2345    if (UnresolvedUsingTypenameDecl *UUD
2346          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2347      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2348        return isInstantiationOf(UUD, UD, Ctx);
2349      }
2350    }
2351
2352    if (UnresolvedUsingValueDecl *UUD
2353          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2354      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2355        return isInstantiationOf(UUD, UD, Ctx);
2356      }
2357    }
2358
2359    return false;
2360  }
2361
2362  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2363    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2364
2365  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2366    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2367
2368  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2369    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2370
2371  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2372    if (Var->isStaticDataMember())
2373      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2374
2375  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2376    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2377
2378  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2379    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2380
2381  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2382        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2383    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2384                             PartialSpec);
2385
2386  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2387    if (!Field->getDeclName()) {
2388      // This is an unnamed field.
2389      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2390        cast<FieldDecl>(D);
2391    }
2392  }
2393
2394  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2395    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2396
2397  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2398    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2399
2400  return D->getDeclName() && isa<NamedDecl>(Other) &&
2401    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2402}
2403
2404template<typename ForwardIterator>
2405static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2406                                      NamedDecl *D,
2407                                      ForwardIterator first,
2408                                      ForwardIterator last) {
2409  for (; first != last; ++first)
2410    if (isInstantiationOf(Ctx, D, *first))
2411      return cast<NamedDecl>(*first);
2412
2413  return 0;
2414}
2415
2416/// \brief Finds the instantiation of the given declaration context
2417/// within the current instantiation.
2418///
2419/// \returns NULL if there was an error
2420DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2421                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2422  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2423    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2424    return cast_or_null<DeclContext>(ID);
2425  } else return DC;
2426}
2427
2428/// \brief Find the instantiation of the given declaration within the
2429/// current instantiation.
2430///
2431/// This routine is intended to be used when \p D is a declaration
2432/// referenced from within a template, that needs to mapped into the
2433/// corresponding declaration within an instantiation. For example,
2434/// given:
2435///
2436/// \code
2437/// template<typename T>
2438/// struct X {
2439///   enum Kind {
2440///     KnownValue = sizeof(T)
2441///   };
2442///
2443///   bool getKind() const { return KnownValue; }
2444/// };
2445///
2446/// template struct X<int>;
2447/// \endcode
2448///
2449/// In the instantiation of X<int>::getKind(), we need to map the
2450/// EnumConstantDecl for KnownValue (which refers to
2451/// X<T>::<Kind>::KnownValue) to its instantiation
2452/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2453/// this mapping from within the instantiation of X<int>.
2454NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2455                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2456  DeclContext *ParentDC = D->getDeclContext();
2457  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2458      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2459      ParentDC->isFunctionOrMethod()) {
2460    // D is a local of some kind. Look into the map of local
2461    // declarations to their instantiations.
2462    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2463  }
2464
2465  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2466    if (!Record->isDependentContext())
2467      return D;
2468
2469    // If the RecordDecl is actually the injected-class-name or a
2470    // "templated" declaration for a class template, class template
2471    // partial specialization, or a member class of a class template,
2472    // substitute into the injected-class-name of the class template
2473    // or partial specialization to find the new DeclContext.
2474    QualType T;
2475    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2476
2477    if (ClassTemplate) {
2478      T = ClassTemplate->getInjectedClassNameSpecialization(Context);
2479    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2480                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2481      ClassTemplate = PartialSpec->getSpecializedTemplate();
2482
2483      // If we call SubstType with an InjectedClassNameType here we
2484      // can end up in an infinite loop.
2485      T = Context.getTypeDeclType(Record);
2486      assert(isa<InjectedClassNameType>(T) &&
2487             "type of partial specialization is not an InjectedClassNameType");
2488      T = cast<InjectedClassNameType>(T)->getUnderlyingType();
2489    }
2490
2491    if (!T.isNull()) {
2492      // Substitute into the injected-class-name to get the type
2493      // corresponding to the instantiation we want, which may also be
2494      // the current instantiation (if we're in a template
2495      // definition). This substitution should never fail, since we
2496      // know we can instantiate the injected-class-name or we
2497      // wouldn't have gotten to the injected-class-name!
2498
2499      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2500      // extra instantiation in the common case?
2501      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2502      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2503
2504      if (!T->isDependentType()) {
2505        assert(T->isRecordType() && "Instantiation must produce a record type");
2506        return T->getAs<RecordType>()->getDecl();
2507      }
2508
2509      // We are performing "partial" template instantiation to create
2510      // the member declarations for the members of a class template
2511      // specialization. Therefore, D is actually referring to something
2512      // in the current instantiation. Look through the current
2513      // context, which contains actual instantiations, to find the
2514      // instantiation of the "current instantiation" that D refers
2515      // to.
2516      bool SawNonDependentContext = false;
2517      for (DeclContext *DC = CurContext; !DC->isFileContext();
2518           DC = DC->getParent()) {
2519        if (ClassTemplateSpecializationDecl *Spec
2520                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2521          if (isInstantiationOf(ClassTemplate,
2522                                Spec->getSpecializedTemplate()))
2523            return Spec;
2524
2525        if (!DC->isDependentContext())
2526          SawNonDependentContext = true;
2527      }
2528
2529      // We're performing "instantiation" of a member of the current
2530      // instantiation while we are type-checking the
2531      // definition. Compute the declaration context and return that.
2532      assert(!SawNonDependentContext &&
2533             "No dependent context while instantiating record");
2534      DeclContext *DC = computeDeclContext(T);
2535      assert(DC &&
2536             "Unable to find declaration for the current instantiation");
2537      return cast<CXXRecordDecl>(DC);
2538    }
2539
2540    // Fall through to deal with other dependent record types (e.g.,
2541    // anonymous unions in class templates).
2542  }
2543
2544  if (!ParentDC->isDependentContext())
2545    return D;
2546
2547  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2548  if (!ParentDC)
2549    return 0;
2550
2551  if (ParentDC != D->getDeclContext()) {
2552    // We performed some kind of instantiation in the parent context,
2553    // so now we need to look into the instantiated parent context to
2554    // find the instantiation of the declaration D.
2555
2556    // If our context used to be dependent, we may need to instantiate
2557    // it before performing lookup into that context.
2558    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2559      if (!Spec->isDependentContext()) {
2560        QualType T = Context.getTypeDeclType(Spec);
2561        const RecordType *Tag = T->getAs<RecordType>();
2562        assert(Tag && "type of non-dependent record is not a RecordType");
2563        if (!Tag->isBeingDefined() &&
2564            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2565          return 0;
2566      }
2567    }
2568
2569    NamedDecl *Result = 0;
2570    if (D->getDeclName()) {
2571      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2572      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2573    } else {
2574      // Since we don't have a name for the entity we're looking for,
2575      // our only option is to walk through all of the declarations to
2576      // find that name. This will occur in a few cases:
2577      //
2578      //   - anonymous struct/union within a template
2579      //   - unnamed class/struct/union/enum within a template
2580      //
2581      // FIXME: Find a better way to find these instantiations!
2582      Result = findInstantiationOf(Context, D,
2583                                   ParentDC->decls_begin(),
2584                                   ParentDC->decls_end());
2585    }
2586
2587    // UsingShadowDecls can instantiate to nothing because of using hiding.
2588    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2589            cast<Decl>(ParentDC)->isInvalidDecl())
2590           && "Unable to find instantiation of declaration!");
2591
2592    D = Result;
2593  }
2594
2595  return D;
2596}
2597
2598/// \brief Performs template instantiation for all implicit template
2599/// instantiations we have seen until this point.
2600void Sema::PerformPendingImplicitInstantiations(bool LocalOnly) {
2601  while (!PendingLocalImplicitInstantiations.empty() ||
2602         (!LocalOnly && !PendingImplicitInstantiations.empty())) {
2603    PendingImplicitInstantiation Inst;
2604
2605    if (PendingLocalImplicitInstantiations.empty()) {
2606      Inst = PendingImplicitInstantiations.front();
2607      PendingImplicitInstantiations.pop_front();
2608    } else {
2609      Inst = PendingLocalImplicitInstantiations.front();
2610      PendingLocalImplicitInstantiations.pop_front();
2611    }
2612
2613    // Instantiate function definitions
2614    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2615      PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Function),
2616                                            Function->getLocation(), *this,
2617                                            Context.getSourceManager(),
2618                                           "instantiating function definition");
2619
2620      if (!Function->getBody())
2621        InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true);
2622      continue;
2623    }
2624
2625    // Instantiate static data member definitions.
2626    VarDecl *Var = cast<VarDecl>(Inst.first);
2627    assert(Var->isStaticDataMember() && "Not a static data member?");
2628
2629    // Don't try to instantiate declarations if the most recent redeclaration
2630    // is invalid.
2631    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2632      continue;
2633
2634    // Check if the most recent declaration has changed the specialization kind
2635    // and removed the need for implicit instantiation.
2636    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2637    case TSK_Undeclared:
2638      assert(false && "Cannot instantitiate an undeclared specialization.");
2639    case TSK_ExplicitInstantiationDeclaration:
2640    case TSK_ExplicitInstantiationDefinition:
2641    case TSK_ExplicitSpecialization:
2642      continue;  // No longer need implicit instantiation.
2643    case TSK_ImplicitInstantiation:
2644      break;
2645    }
2646
2647    PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Var),
2648                                          Var->getLocation(), *this,
2649                                          Context.getSourceManager(),
2650                                          "instantiating static data member "
2651                                          "definition");
2652
2653    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true);
2654  }
2655}
2656
2657void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2658                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2659  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2660         E = Pattern->ddiag_end(); I != E; ++I) {
2661    DependentDiagnostic *DD = *I;
2662
2663    switch (DD->getKind()) {
2664    case DependentDiagnostic::Access:
2665      HandleDependentAccessCheck(*DD, TemplateArgs);
2666      break;
2667    }
2668  }
2669}
2670