SemaTemplateInstantiateDecl.cpp revision 2187bd5e166890241f1611afca7eb7f7e3e7a0fe 
1//===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//===----------------------------------------------------------------------===/
8//
9//  This file implements C++ template instantiation for declarations.
10//
11//===----------------------------------------------------------------------===/
12#include "Sema.h"
13#include "Lookup.h"
14#include "clang/AST/ASTConsumer.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/DeclTemplate.h"
17#include "clang/AST/DeclVisitor.h"
18#include "clang/AST/DependentDiagnostic.h"
19#include "clang/AST/Expr.h"
20#include "clang/AST/ExprCXX.h"
21#include "clang/AST/TypeLoc.h"
22#include "clang/Basic/PrettyStackTrace.h"
23#include "clang/Lex/Preprocessor.h"
24
25using namespace clang;
26
27namespace {
28  class TemplateDeclInstantiator
29    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
30    Sema &SemaRef;
31    DeclContext *Owner;
32    const MultiLevelTemplateArgumentList &TemplateArgs;
33
34    void InstantiateAttrs(Decl *Tmpl, Decl *New);
35
36  public:
37    typedef Sema::OwningExprResult OwningExprResult;
38
39    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
40                             const MultiLevelTemplateArgumentList &TemplateArgs)
41      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
42
43    // FIXME: Once we get closer to completion, replace these manually-written
44    // declarations with automatically-generated ones from
45    // clang/AST/DeclNodes.def.
46    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
47    Decl *VisitNamespaceDecl(NamespaceDecl *D);
48    Decl *VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
49    Decl *VisitTypedefDecl(TypedefDecl *D);
50    Decl *VisitVarDecl(VarDecl *D);
51    Decl *VisitFieldDecl(FieldDecl *D);
52    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
53    Decl *VisitEnumDecl(EnumDecl *D);
54    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
55    Decl *VisitFriendDecl(FriendDecl *D);
56    Decl *VisitFunctionDecl(FunctionDecl *D,
57                            TemplateParameterList *TemplateParams = 0);
58    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
59    Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
60                             TemplateParameterList *TemplateParams = 0);
61    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
62    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
63    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
64    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
65    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
66    Decl *VisitClassTemplatePartialSpecializationDecl(
67                                    ClassTemplatePartialSpecializationDecl *D);
68    Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
69    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
70    Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
71    Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
72    Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
73    Decl *VisitUsingDecl(UsingDecl *D);
74    Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
75    Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
76    Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
77
78    // Base case. FIXME: Remove once we can instantiate everything.
79    Decl *VisitDecl(Decl *D) {
80      unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
81                                                            Diagnostic::Error,
82                                                   "cannot instantiate %0 yet");
83      SemaRef.Diag(D->getLocation(), DiagID)
84        << D->getDeclKindName();
85
86      return 0;
87    }
88
89    const LangOptions &getLangOptions() {
90      return SemaRef.getLangOptions();
91    }
92
93    // Helper functions for instantiating methods.
94    TypeSourceInfo *SubstFunctionType(FunctionDecl *D,
95                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
96    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
97    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
98
99    TemplateParameterList *
100      SubstTemplateParams(TemplateParameterList *List);
101
102    bool SubstQualifier(const DeclaratorDecl *OldDecl,
103                        DeclaratorDecl *NewDecl);
104    bool SubstQualifier(const TagDecl *OldDecl,
105                        TagDecl *NewDecl);
106
107    bool InstantiateClassTemplatePartialSpecialization(
108                                              ClassTemplateDecl *ClassTemplate,
109                           ClassTemplatePartialSpecializationDecl *PartialSpec);
110  };
111}
112
113bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
114                                              DeclaratorDecl *NewDecl) {
115  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
116  if (!OldQual) return false;
117
118  SourceRange QualRange = OldDecl->getQualifierRange();
119
120  NestedNameSpecifier *NewQual
121    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
122  if (!NewQual)
123    return true;
124
125  NewDecl->setQualifierInfo(NewQual, QualRange);
126  return false;
127}
128
129bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
130                                              TagDecl *NewDecl) {
131  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
132  if (!OldQual) return false;
133
134  SourceRange QualRange = OldDecl->getQualifierRange();
135
136  NestedNameSpecifier *NewQual
137    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
138  if (!NewQual)
139    return true;
140
141  NewDecl->setQualifierInfo(NewQual, QualRange);
142  return false;
143}
144
145// FIXME: Is this too simple?
146void TemplateDeclInstantiator::InstantiateAttrs(Decl *Tmpl, Decl *New) {
147  for (const Attr *TmplAttr = Tmpl->getAttrs(); TmplAttr;
148       TmplAttr = TmplAttr->getNext()) {
149
150    // FIXME: Is cloning correct for all attributes?
151    Attr *NewAttr = TmplAttr->clone(SemaRef.Context);
152
153    New->addAttr(NewAttr);
154  }
155}
156
157Decl *
158TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
159  assert(false && "Translation units cannot be instantiated");
160  return D;
161}
162
163Decl *
164TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
165  assert(false && "Namespaces cannot be instantiated");
166  return D;
167}
168
169Decl *
170TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
171  NamespaceAliasDecl *Inst
172    = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
173                                 D->getNamespaceLoc(),
174                                 D->getAliasLoc(),
175                                 D->getNamespace()->getIdentifier(),
176                                 D->getQualifierRange(),
177                                 D->getQualifier(),
178                                 D->getTargetNameLoc(),
179                                 D->getNamespace());
180  Owner->addDecl(Inst);
181  return Inst;
182}
183
184Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
185  bool Invalid = false;
186  TypeSourceInfo *DI = D->getTypeSourceInfo();
187  if (DI->getType()->isDependentType()) {
188    DI = SemaRef.SubstType(DI, TemplateArgs,
189                           D->getLocation(), D->getDeclName());
190    if (!DI) {
191      Invalid = true;
192      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
193    }
194  }
195
196  // Create the new typedef
197  TypedefDecl *Typedef
198    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
199                          D->getIdentifier(), DI);
200  if (Invalid)
201    Typedef->setInvalidDecl();
202
203  if (TypedefDecl *Prev = D->getPreviousDeclaration()) {
204    NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
205                                                       TemplateArgs);
206    Typedef->setPreviousDeclaration(cast<TypedefDecl>(InstPrev));
207  }
208
209  Typedef->setAccess(D->getAccess());
210  Owner->addDecl(Typedef);
211
212  return Typedef;
213}
214
215/// \brief Instantiate the arguments provided as part of initialization.
216///
217/// \returns true if an error occurred, false otherwise.
218static bool InstantiateInitializationArguments(Sema &SemaRef,
219                                               Expr **Args, unsigned NumArgs,
220                           const MultiLevelTemplateArgumentList &TemplateArgs,
221                         llvm::SmallVectorImpl<SourceLocation> &FakeCommaLocs,
222                           ASTOwningVector<&ActionBase::DeleteExpr> &InitArgs) {
223  for (unsigned I = 0; I != NumArgs; ++I) {
224    // When we hit the first defaulted argument, break out of the loop:
225    // we don't pass those default arguments on.
226    if (Args[I]->isDefaultArgument())
227      break;
228
229    Sema::OwningExprResult Arg = SemaRef.SubstExpr(Args[I], TemplateArgs);
230    if (Arg.isInvalid())
231      return true;
232
233    Expr *ArgExpr = (Expr *)Arg.get();
234    InitArgs.push_back(Arg.release());
235
236    // FIXME: We're faking all of the comma locations. Do we need them?
237    FakeCommaLocs.push_back(
238                          SemaRef.PP.getLocForEndOfToken(ArgExpr->getLocEnd()));
239  }
240
241  return false;
242}
243
244/// \brief Instantiate an initializer, breaking it into separate
245/// initialization arguments.
246///
247/// \param S The semantic analysis object.
248///
249/// \param Init The initializer to instantiate.
250///
251/// \param TemplateArgs Template arguments to be substituted into the
252/// initializer.
253///
254/// \param NewArgs Will be filled in with the instantiation arguments.
255///
256/// \returns true if an error occurred, false otherwise
257static bool InstantiateInitializer(Sema &S, Expr *Init,
258                            const MultiLevelTemplateArgumentList &TemplateArgs,
259                                   SourceLocation &LParenLoc,
260                               llvm::SmallVector<SourceLocation, 4> &CommaLocs,
261                             ASTOwningVector<&ActionBase::DeleteExpr> &NewArgs,
262                                   SourceLocation &RParenLoc) {
263  NewArgs.clear();
264  LParenLoc = SourceLocation();
265  RParenLoc = SourceLocation();
266
267  if (!Init)
268    return false;
269
270  if (CXXExprWithTemporaries *ExprTemp = dyn_cast<CXXExprWithTemporaries>(Init))
271    Init = ExprTemp->getSubExpr();
272
273  while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init))
274    Init = Binder->getSubExpr();
275
276  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
277    Init = ICE->getSubExprAsWritten();
278
279  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
280    LParenLoc = ParenList->getLParenLoc();
281    RParenLoc = ParenList->getRParenLoc();
282    return InstantiateInitializationArguments(S, ParenList->getExprs(),
283                                              ParenList->getNumExprs(),
284                                              TemplateArgs, CommaLocs,
285                                              NewArgs);
286  }
287
288  if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) {
289    if (!isa<CXXTemporaryObjectExpr>(Construct)) {
290      if (InstantiateInitializationArguments(S,
291                                             Construct->getArgs(),
292                                             Construct->getNumArgs(),
293                                             TemplateArgs,
294                                             CommaLocs, NewArgs))
295        return true;
296
297      // FIXME: Fake locations!
298      LParenLoc = S.PP.getLocForEndOfToken(Init->getLocStart());
299      RParenLoc = CommaLocs.empty()? LParenLoc : CommaLocs.back();
300      return false;
301    }
302  }
303
304  Sema::OwningExprResult Result = S.SubstExpr(Init, TemplateArgs);
305  if (Result.isInvalid())
306    return true;
307
308  NewArgs.push_back(Result.takeAs<Expr>());
309  return false;
310}
311
312Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
313  // Do substitution on the type of the declaration
314  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
315                                         TemplateArgs,
316                                         D->getTypeSpecStartLoc(),
317                                         D->getDeclName());
318  if (!DI)
319    return 0;
320
321  // Build the instantiated declaration
322  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
323                                 D->getLocation(), D->getIdentifier(),
324                                 DI->getType(), DI,
325                                 D->getStorageClass());
326  Var->setThreadSpecified(D->isThreadSpecified());
327  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
328  Var->setDeclaredInCondition(D->isDeclaredInCondition());
329
330  // Substitute the nested name specifier, if any.
331  if (SubstQualifier(D, Var))
332    return 0;
333
334  // If we are instantiating a static data member defined
335  // out-of-line, the instantiation will have the same lexical
336  // context (which will be a namespace scope) as the template.
337  if (D->isOutOfLine())
338    Var->setLexicalDeclContext(D->getLexicalDeclContext());
339
340  Var->setAccess(D->getAccess());
341
342  // FIXME: In theory, we could have a previous declaration for variables that
343  // are not static data members.
344  bool Redeclaration = false;
345  // FIXME: having to fake up a LookupResult is dumb.
346  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
347                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
348  if (D->isStaticDataMember())
349    SemaRef.LookupQualifiedName(Previous, Owner, false);
350  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
351
352  if (D->isOutOfLine()) {
353    D->getLexicalDeclContext()->addDecl(Var);
354    Owner->makeDeclVisibleInContext(Var);
355  } else {
356    Owner->addDecl(Var);
357  }
358
359  // Link instantiations of static data members back to the template from
360  // which they were instantiated.
361  if (Var->isStaticDataMember())
362    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
363                                                     TSK_ImplicitInstantiation);
364
365  if (Var->getAnyInitializer()) {
366    // We already have an initializer in the class.
367  } else if (D->getInit()) {
368    if (Var->isStaticDataMember() && !D->isOutOfLine())
369      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
370    else
371      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
372
373    // Instantiate the initializer.
374    SourceLocation LParenLoc, RParenLoc;
375    llvm::SmallVector<SourceLocation, 4> CommaLocs;
376    ASTOwningVector<&ActionBase::DeleteExpr> InitArgs(SemaRef);
377    if (!InstantiateInitializer(SemaRef, D->getInit(), TemplateArgs, LParenLoc,
378                                CommaLocs, InitArgs, RParenLoc)) {
379      // Attach the initializer to the declaration.
380      if (D->hasCXXDirectInitializer()) {
381        // Add the direct initializer to the declaration.
382        SemaRef.AddCXXDirectInitializerToDecl(Sema::DeclPtrTy::make(Var),
383                                              LParenLoc,
384                                              move_arg(InitArgs),
385                                              CommaLocs.data(),
386                                              RParenLoc);
387      } else if (InitArgs.size() == 1) {
388        Expr *Init = (Expr*)(InitArgs.take()[0]);
389        SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var),
390                                     SemaRef.Owned(Init),
391                                     false);
392      } else {
393        assert(InitArgs.size() == 0);
394        SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
395      }
396    } else {
397      // FIXME: Not too happy about invalidating the declaration
398      // because of a bogus initializer.
399      Var->setInvalidDecl();
400    }
401
402    SemaRef.PopExpressionEvaluationContext();
403  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
404    SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
405
406  return Var;
407}
408
409Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
410  bool Invalid = false;
411  TypeSourceInfo *DI = D->getTypeSourceInfo();
412  if (DI->getType()->isDependentType())  {
413    DI = SemaRef.SubstType(DI, TemplateArgs,
414                           D->getLocation(), D->getDeclName());
415    if (!DI) {
416      DI = D->getTypeSourceInfo();
417      Invalid = true;
418    } else if (DI->getType()->isFunctionType()) {
419      // C++ [temp.arg.type]p3:
420      //   If a declaration acquires a function type through a type
421      //   dependent on a template-parameter and this causes a
422      //   declaration that does not use the syntactic form of a
423      //   function declarator to have function type, the program is
424      //   ill-formed.
425      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
426        << DI->getType();
427      Invalid = true;
428    }
429  }
430
431  Expr *BitWidth = D->getBitWidth();
432  if (Invalid)
433    BitWidth = 0;
434  else if (BitWidth) {
435    // The bit-width expression is not potentially evaluated.
436    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
437
438    OwningExprResult InstantiatedBitWidth
439      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
440    if (InstantiatedBitWidth.isInvalid()) {
441      Invalid = true;
442      BitWidth = 0;
443    } else
444      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
445  }
446
447  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
448                                            DI->getType(), DI,
449                                            cast<RecordDecl>(Owner),
450                                            D->getLocation(),
451                                            D->isMutable(),
452                                            BitWidth,
453                                            D->getTypeSpecStartLoc(),
454                                            D->getAccess(),
455                                            0);
456  if (!Field) {
457    cast<Decl>(Owner)->setInvalidDecl();
458    return 0;
459  }
460
461  InstantiateAttrs(D, Field);
462
463  if (Invalid)
464    Field->setInvalidDecl();
465
466  if (!Field->getDeclName()) {
467    // Keep track of where this decl came from.
468    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
469  }
470
471  Field->setImplicit(D->isImplicit());
472  Field->setAccess(D->getAccess());
473  Owner->addDecl(Field);
474
475  return Field;
476}
477
478Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
479  FriendDecl::FriendUnion FU;
480
481  // Handle friend type expressions by simply substituting template
482  // parameters into the pattern type.
483  if (Type *Ty = D->getFriendType()) {
484    QualType T = SemaRef.SubstType(QualType(Ty,0), TemplateArgs,
485                                   D->getLocation(), DeclarationName());
486    if (T.isNull()) return 0;
487
488    assert(getLangOptions().CPlusPlus0x || T->isRecordType());
489    FU = T.getTypePtr();
490
491  // Handle everything else by appropriate substitution.
492  } else {
493    NamedDecl *ND = D->getFriendDecl();
494    assert(ND && "friend decl must be a decl or a type!");
495
496    // FIXME: We have a problem here, because the nested call to Visit(ND)
497    // will inject the thing that the friend references into the current
498    // owner, which is wrong.
499    Decl *NewND;
500
501    // Hack to make this work almost well pending a rewrite.
502    if (ND->getDeclContext()->isRecord()) {
503      if (!ND->getDeclContext()->isDependentContext()) {
504        NewND = SemaRef.FindInstantiatedDecl(D->getLocation(), ND,
505                                             TemplateArgs);
506      } else {
507        // FIXME: Hack to avoid crashing when incorrectly trying to instantiate
508        // templated friend declarations. This doesn't produce a correct AST;
509        // however this is sufficient for some AST analysis. The real solution
510        // must be put in place during the pending rewrite. See PR5848.
511        return 0;
512      }
513    } else if (D->wasSpecialization()) {
514      // Totally egregious hack to work around PR5866
515      return 0;
516    } else
517      NewND = Visit(ND);
518    if (!NewND) return 0;
519
520    FU = cast<NamedDecl>(NewND);
521  }
522
523  FriendDecl *FD =
524    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(), FU,
525                       D->getFriendLoc());
526  FD->setAccess(AS_public);
527  Owner->addDecl(FD);
528  return FD;
529}
530
531Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
532  Expr *AssertExpr = D->getAssertExpr();
533
534  // The expression in a static assertion is not potentially evaluated.
535  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
536
537  OwningExprResult InstantiatedAssertExpr
538    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
539  if (InstantiatedAssertExpr.isInvalid())
540    return 0;
541
542  OwningExprResult Message(SemaRef, D->getMessage());
543  D->getMessage()->Retain();
544  Decl *StaticAssert
545    = SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
546                                           move(InstantiatedAssertExpr),
547                                           move(Message)).getAs<Decl>();
548  return StaticAssert;
549}
550
551Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
552  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
553                                    D->getLocation(), D->getIdentifier(),
554                                    D->getTagKeywordLoc(),
555                                    /*PrevDecl=*/0);
556  Enum->setInstantiationOfMemberEnum(D);
557  Enum->setAccess(D->getAccess());
558  if (SubstQualifier(D, Enum)) return 0;
559  Owner->addDecl(Enum);
560  Enum->startDefinition();
561
562  if (D->getDeclContext()->isFunctionOrMethod())
563    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
564
565  llvm::SmallVector<Sema::DeclPtrTy, 4> Enumerators;
566
567  EnumConstantDecl *LastEnumConst = 0;
568  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
569         ECEnd = D->enumerator_end();
570       EC != ECEnd; ++EC) {
571    // The specified value for the enumerator.
572    OwningExprResult Value = SemaRef.Owned((Expr *)0);
573    if (Expr *UninstValue = EC->getInitExpr()) {
574      // The enumerator's value expression is not potentially evaluated.
575      EnterExpressionEvaluationContext Unevaluated(SemaRef,
576                                                   Action::Unevaluated);
577
578      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
579    }
580
581    // Drop the initial value and continue.
582    bool isInvalid = false;
583    if (Value.isInvalid()) {
584      Value = SemaRef.Owned((Expr *)0);
585      isInvalid = true;
586    }
587
588    EnumConstantDecl *EnumConst
589      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
590                                  EC->getLocation(), EC->getIdentifier(),
591                                  move(Value));
592
593    if (isInvalid) {
594      if (EnumConst)
595        EnumConst->setInvalidDecl();
596      Enum->setInvalidDecl();
597    }
598
599    if (EnumConst) {
600      EnumConst->setAccess(Enum->getAccess());
601      Enum->addDecl(EnumConst);
602      Enumerators.push_back(Sema::DeclPtrTy::make(EnumConst));
603      LastEnumConst = EnumConst;
604
605      if (D->getDeclContext()->isFunctionOrMethod()) {
606        // If the enumeration is within a function or method, record the enum
607        // constant as a local.
608        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
609      }
610    }
611  }
612
613  // FIXME: Fixup LBraceLoc and RBraceLoc
614  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
615  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
616                        Sema::DeclPtrTy::make(Enum),
617                        &Enumerators[0], Enumerators.size(),
618                        0, 0);
619
620  return Enum;
621}
622
623Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
624  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
625  return 0;
626}
627
628namespace {
629  class SortDeclByLocation {
630    SourceManager &SourceMgr;
631
632  public:
633    explicit SortDeclByLocation(SourceManager &SourceMgr)
634      : SourceMgr(SourceMgr) { }
635
636    bool operator()(const Decl *X, const Decl *Y) const {
637      return SourceMgr.isBeforeInTranslationUnit(X->getLocation(),
638                                                 Y->getLocation());
639    }
640  };
641}
642
643Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
644  // Create a local instantiation scope for this class template, which
645  // will contain the instantiations of the template parameters.
646  Sema::LocalInstantiationScope Scope(SemaRef);
647  TemplateParameterList *TempParams = D->getTemplateParameters();
648  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
649  if (!InstParams)
650    return NULL;
651
652  CXXRecordDecl *Pattern = D->getTemplatedDecl();
653  CXXRecordDecl *RecordInst
654    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), Owner,
655                            Pattern->getLocation(), Pattern->getIdentifier(),
656                            Pattern->getTagKeywordLoc(), /*PrevDecl=*/ NULL,
657                            /*DelayTypeCreation=*/true);
658
659  // Substitute the nested name specifier, if any.
660  if (SubstQualifier(Pattern, RecordInst))
661    return 0;
662
663  ClassTemplateDecl *Inst
664    = ClassTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
665                                D->getIdentifier(), InstParams, RecordInst, 0);
666  RecordInst->setDescribedClassTemplate(Inst);
667  if (D->getFriendObjectKind())
668    Inst->setObjectOfFriendDecl(true);
669  else
670    Inst->setAccess(D->getAccess());
671  Inst->setInstantiatedFromMemberTemplate(D);
672
673  // Trigger creation of the type for the instantiation.
674  SemaRef.Context.getInjectedClassNameType(RecordInst,
675                  Inst->getInjectedClassNameSpecialization(SemaRef.Context));
676
677  // Finish handling of friends.
678  if (Inst->getFriendObjectKind()) {
679    return Inst;
680  }
681
682  Inst->setAccess(D->getAccess());
683  Owner->addDecl(Inst);
684
685  // First, we sort the partial specializations by location, so
686  // that we instantiate them in the order they were declared.
687  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
688  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
689         P = D->getPartialSpecializations().begin(),
690         PEnd = D->getPartialSpecializations().end();
691       P != PEnd; ++P)
692    PartialSpecs.push_back(&*P);
693  std::sort(PartialSpecs.begin(), PartialSpecs.end(),
694            SortDeclByLocation(SemaRef.SourceMgr));
695
696  // Instantiate all of the partial specializations of this member class
697  // template.
698  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
699    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
700
701  return Inst;
702}
703
704Decl *
705TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
706                                   ClassTemplatePartialSpecializationDecl *D) {
707  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
708
709  // Lookup the already-instantiated declaration in the instantiation
710  // of the class template and return that.
711  DeclContext::lookup_result Found
712    = Owner->lookup(ClassTemplate->getDeclName());
713  if (Found.first == Found.second)
714    return 0;
715
716  ClassTemplateDecl *InstClassTemplate
717    = dyn_cast<ClassTemplateDecl>(*Found.first);
718  if (!InstClassTemplate)
719    return 0;
720
721  Decl *DCanon = D->getCanonicalDecl();
722  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
723            P = InstClassTemplate->getPartialSpecializations().begin(),
724         PEnd = InstClassTemplate->getPartialSpecializations().end();
725       P != PEnd; ++P) {
726    if (P->getInstantiatedFromMember()->getCanonicalDecl() == DCanon)
727      return &*P;
728  }
729
730  return 0;
731}
732
733Decl *
734TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
735  // Create a local instantiation scope for this function template, which
736  // will contain the instantiations of the template parameters and then get
737  // merged with the local instantiation scope for the function template
738  // itself.
739  Sema::LocalInstantiationScope Scope(SemaRef);
740
741  TemplateParameterList *TempParams = D->getTemplateParameters();
742  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
743  if (!InstParams)
744    return NULL;
745
746  FunctionDecl *Instantiated = 0;
747  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
748    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
749                                                                 InstParams));
750  else
751    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
752                                                          D->getTemplatedDecl(),
753                                                                InstParams));
754
755  if (!Instantiated)
756    return 0;
757
758  Instantiated->setAccess(D->getAccess());
759
760  // Link the instantiated function template declaration to the function
761  // template from which it was instantiated.
762  FunctionTemplateDecl *InstTemplate
763    = Instantiated->getDescribedFunctionTemplate();
764  InstTemplate->setAccess(D->getAccess());
765  assert(InstTemplate &&
766         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
767
768  // Link the instantiation back to the pattern *unless* this is a
769  // non-definition friend declaration.
770  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
771      !(InstTemplate->getFriendObjectKind() &&
772        !D->getTemplatedDecl()->isThisDeclarationADefinition()))
773    InstTemplate->setInstantiatedFromMemberTemplate(D);
774
775  // Add non-friends into the owner.
776  if (!InstTemplate->getFriendObjectKind())
777    Owner->addDecl(InstTemplate);
778  return InstTemplate;
779}
780
781Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
782  CXXRecordDecl *PrevDecl = 0;
783  if (D->isInjectedClassName())
784    PrevDecl = cast<CXXRecordDecl>(Owner);
785  else if (D->getPreviousDeclaration()) {
786    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
787                                                   D->getPreviousDeclaration(),
788                                                   TemplateArgs);
789    if (!Prev) return 0;
790    PrevDecl = cast<CXXRecordDecl>(Prev);
791  }
792
793  CXXRecordDecl *Record
794    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
795                            D->getLocation(), D->getIdentifier(),
796                            D->getTagKeywordLoc(), PrevDecl);
797
798  // Substitute the nested name specifier, if any.
799  if (SubstQualifier(D, Record))
800    return 0;
801
802  Record->setImplicit(D->isImplicit());
803  // FIXME: Check against AS_none is an ugly hack to work around the issue that
804  // the tag decls introduced by friend class declarations don't have an access
805  // specifier. Remove once this area of the code gets sorted out.
806  if (D->getAccess() != AS_none)
807    Record->setAccess(D->getAccess());
808  if (!D->isInjectedClassName())
809    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
810
811  // If the original function was part of a friend declaration,
812  // inherit its namespace state.
813  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
814    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
815
816  Record->setAnonymousStructOrUnion(D->isAnonymousStructOrUnion());
817
818  Owner->addDecl(Record);
819  return Record;
820}
821
822/// Normal class members are of more specific types and therefore
823/// don't make it here.  This function serves two purposes:
824///   1) instantiating function templates
825///   2) substituting friend declarations
826/// FIXME: preserve function definitions in case #2
827Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
828                                       TemplateParameterList *TemplateParams) {
829  // Check whether there is already a function template specialization for
830  // this declaration.
831  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
832  void *InsertPos = 0;
833  if (FunctionTemplate && !TemplateParams) {
834    llvm::FoldingSetNodeID ID;
835    FunctionTemplateSpecializationInfo::Profile(ID,
836                             TemplateArgs.getInnermost().getFlatArgumentList(),
837                                       TemplateArgs.getInnermost().flat_size(),
838                                                SemaRef.Context);
839
840    FunctionTemplateSpecializationInfo *Info
841      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
842                                                                   InsertPos);
843
844    // If we already have a function template specialization, return it.
845    if (Info)
846      return Info->Function;
847  }
848
849  bool MergeWithParentScope = (TemplateParams != 0) ||
850    !(isa<Decl>(Owner) &&
851      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
852  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
853
854  llvm::SmallVector<ParmVarDecl *, 4> Params;
855  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
856  TInfo = SubstFunctionType(D, Params);
857  if (!TInfo)
858    return 0;
859  QualType T = TInfo->getType();
860
861  // If we're instantiating a local function declaration, put the result
862  // in the owner;  otherwise we need to find the instantiated context.
863  DeclContext *DC;
864  if (D->getDeclContext()->isFunctionOrMethod())
865    DC = Owner;
866  else
867    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
868                                         TemplateArgs);
869
870  FunctionDecl *Function =
871      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
872                           D->getDeclName(), T, TInfo,
873                           D->getStorageClass(),
874                           D->isInlineSpecified(), D->hasWrittenPrototype());
875
876  // Substitute the nested name specifier, if any.
877  if (SubstQualifier(D, Function))
878    return 0;
879
880  Function->setLexicalDeclContext(Owner);
881
882  // Attach the parameters
883  for (unsigned P = 0; P < Params.size(); ++P)
884    Params[P]->setOwningFunction(Function);
885  Function->setParams(Params.data(), Params.size());
886
887  if (TemplateParams) {
888    // Our resulting instantiation is actually a function template, since we
889    // are substituting only the outer template parameters. For example, given
890    //
891    //   template<typename T>
892    //   struct X {
893    //     template<typename U> friend void f(T, U);
894    //   };
895    //
896    //   X<int> x;
897    //
898    // We are instantiating the friend function template "f" within X<int>,
899    // which means substituting int for T, but leaving "f" as a friend function
900    // template.
901    // Build the function template itself.
902    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Owner,
903                                                    Function->getLocation(),
904                                                    Function->getDeclName(),
905                                                    TemplateParams, Function);
906    Function->setDescribedFunctionTemplate(FunctionTemplate);
907    FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
908  } else if (FunctionTemplate) {
909    // Record this function template specialization.
910    Function->setFunctionTemplateSpecialization(FunctionTemplate,
911                                                &TemplateArgs.getInnermost(),
912                                                InsertPos);
913  }
914
915  if (InitFunctionInstantiation(Function, D))
916    Function->setInvalidDecl();
917
918  bool Redeclaration = false;
919  bool OverloadableAttrRequired = false;
920
921  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
922                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
923
924  if (TemplateParams || !FunctionTemplate) {
925    // Look only into the namespace where the friend would be declared to
926    // find a previous declaration. This is the innermost enclosing namespace,
927    // as described in ActOnFriendFunctionDecl.
928    SemaRef.LookupQualifiedName(Previous, DC);
929
930    // In C++, the previous declaration we find might be a tag type
931    // (class or enum). In this case, the new declaration will hide the
932    // tag type. Note that this does does not apply if we're declaring a
933    // typedef (C++ [dcl.typedef]p4).
934    if (Previous.isSingleTagDecl())
935      Previous.clear();
936  }
937
938  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
939                                   false, Redeclaration,
940                                   /*FIXME:*/OverloadableAttrRequired);
941
942  // If the original function was part of a friend declaration,
943  // inherit its namespace state and add it to the owner.
944  NamedDecl *FromFriendD
945      = TemplateParams? cast<NamedDecl>(D->getDescribedFunctionTemplate()) : D;
946  if (FromFriendD->getFriendObjectKind()) {
947    NamedDecl *ToFriendD = 0;
948    NamedDecl *PrevDecl;
949    if (TemplateParams) {
950      ToFriendD = cast<NamedDecl>(FunctionTemplate);
951      PrevDecl = FunctionTemplate->getPreviousDeclaration();
952    } else {
953      ToFriendD = Function;
954      PrevDecl = Function->getPreviousDeclaration();
955    }
956    ToFriendD->setObjectOfFriendDecl(PrevDecl != NULL);
957    if (!Owner->isDependentContext() && !PrevDecl)
958      DC->makeDeclVisibleInContext(ToFriendD, /* Recoverable = */ false);
959
960    if (!TemplateParams)
961      Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
962  }
963
964  return Function;
965}
966
967Decl *
968TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
969                                      TemplateParameterList *TemplateParams) {
970  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
971  void *InsertPos = 0;
972  if (FunctionTemplate && !TemplateParams) {
973    // We are creating a function template specialization from a function
974    // template. Check whether there is already a function template
975    // specialization for this particular set of template arguments.
976    llvm::FoldingSetNodeID ID;
977    FunctionTemplateSpecializationInfo::Profile(ID,
978                            TemplateArgs.getInnermost().getFlatArgumentList(),
979                                      TemplateArgs.getInnermost().flat_size(),
980                                                SemaRef.Context);
981
982    FunctionTemplateSpecializationInfo *Info
983      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
984                                                                   InsertPos);
985
986    // If we already have a function template specialization, return it.
987    if (Info)
988      return Info->Function;
989  }
990
991  bool MergeWithParentScope = (TemplateParams != 0) ||
992    !(isa<Decl>(Owner) &&
993      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
994  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
995
996  llvm::SmallVector<ParmVarDecl *, 4> Params;
997  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
998  TInfo = SubstFunctionType(D, Params);
999  if (!TInfo)
1000    return 0;
1001  QualType T = TInfo->getType();
1002
1003  // Build the instantiated method declaration.
1004  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
1005  CXXMethodDecl *Method = 0;
1006
1007  DeclarationName Name = D->getDeclName();
1008  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1009    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1010    Name = SemaRef.Context.DeclarationNames.getCXXConstructorName(
1011                                    SemaRef.Context.getCanonicalType(ClassTy));
1012    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1013                                        Constructor->getLocation(),
1014                                        Name, T, TInfo,
1015                                        Constructor->isExplicit(),
1016                                        Constructor->isInlineSpecified(), false);
1017  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1018    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1019    Name = SemaRef.Context.DeclarationNames.getCXXDestructorName(
1020                                   SemaRef.Context.getCanonicalType(ClassTy));
1021    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1022                                       Destructor->getLocation(), Name,
1023                                       T, Destructor->isInlineSpecified(), false);
1024  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1025    CanQualType ConvTy
1026      = SemaRef.Context.getCanonicalType(
1027                                      T->getAs<FunctionType>()->getResultType());
1028    Name = SemaRef.Context.DeclarationNames.getCXXConversionFunctionName(
1029                                                                      ConvTy);
1030    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1031                                       Conversion->getLocation(), Name,
1032                                       T, TInfo,
1033                                       Conversion->isInlineSpecified(),
1034                                       Conversion->isExplicit());
1035  } else {
1036    Method = CXXMethodDecl::Create(SemaRef.Context, Record, D->getLocation(),
1037                                   D->getDeclName(), T, TInfo,
1038                                   D->isStatic(), D->isInlineSpecified());
1039  }
1040
1041  // Substitute the nested name specifier, if any.
1042  if (SubstQualifier(D, Method))
1043    return 0;
1044
1045  if (TemplateParams) {
1046    // Our resulting instantiation is actually a function template, since we
1047    // are substituting only the outer template parameters. For example, given
1048    //
1049    //   template<typename T>
1050    //   struct X {
1051    //     template<typename U> void f(T, U);
1052    //   };
1053    //
1054    //   X<int> x;
1055    //
1056    // We are instantiating the member template "f" within X<int>, which means
1057    // substituting int for T, but leaving "f" as a member function template.
1058    // Build the function template itself.
1059    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1060                                                    Method->getLocation(),
1061                                                    Method->getDeclName(),
1062                                                    TemplateParams, Method);
1063    if (D->isOutOfLine())
1064      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1065    Method->setDescribedFunctionTemplate(FunctionTemplate);
1066  } else if (FunctionTemplate) {
1067    // Record this function template specialization.
1068    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1069                                              &TemplateArgs.getInnermost(),
1070                                              InsertPos);
1071  } else {
1072    // Record that this is an instantiation of a member function.
1073    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1074  }
1075
1076  // If we are instantiating a member function defined
1077  // out-of-line, the instantiation will have the same lexical
1078  // context (which will be a namespace scope) as the template.
1079  if (D->isOutOfLine())
1080    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1081
1082  // Attach the parameters
1083  for (unsigned P = 0; P < Params.size(); ++P)
1084    Params[P]->setOwningFunction(Method);
1085  Method->setParams(Params.data(), Params.size());
1086
1087  if (InitMethodInstantiation(Method, D))
1088    Method->setInvalidDecl();
1089
1090  LookupResult Previous(SemaRef, Name, SourceLocation(),
1091                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1092
1093  if (!FunctionTemplate || TemplateParams) {
1094    SemaRef.LookupQualifiedName(Previous, Owner);
1095
1096    // In C++, the previous declaration we find might be a tag type
1097    // (class or enum). In this case, the new declaration will hide the
1098    // tag type. Note that this does does not apply if we're declaring a
1099    // typedef (C++ [dcl.typedef]p4).
1100    if (Previous.isSingleTagDecl())
1101      Previous.clear();
1102  }
1103
1104  bool Redeclaration = false;
1105  bool OverloadableAttrRequired = false;
1106  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1107                                   /*FIXME:*/OverloadableAttrRequired);
1108
1109  if (D->isPure())
1110    SemaRef.CheckPureMethod(Method, SourceRange());
1111
1112  Method->setAccess(D->getAccess());
1113
1114  if (!FunctionTemplate && (!Method->isInvalidDecl() || Previous.empty()) &&
1115      !Method->getFriendObjectKind())
1116    Owner->addDecl(Method);
1117
1118  return Method;
1119}
1120
1121Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1122  return VisitCXXMethodDecl(D);
1123}
1124
1125Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1126  return VisitCXXMethodDecl(D);
1127}
1128
1129Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1130  return VisitCXXMethodDecl(D);
1131}
1132
1133ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1134  QualType T;
1135  TypeSourceInfo *DI = D->getTypeSourceInfo();
1136  if (DI) {
1137    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1138                           D->getDeclName());
1139    if (DI) T = DI->getType();
1140  } else {
1141    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1142                          D->getDeclName());
1143    DI = 0;
1144  }
1145
1146  if (T.isNull())
1147    return 0;
1148
1149  T = SemaRef.adjustParameterType(T);
1150
1151  // Allocate the parameter
1152  ParmVarDecl *Param
1153    = ParmVarDecl::Create(SemaRef.Context,
1154                          SemaRef.Context.getTranslationUnitDecl(),
1155                          D->getLocation(),
1156                          D->getIdentifier(), T, DI, D->getStorageClass(), 0);
1157
1158  // Mark the default argument as being uninstantiated.
1159  if (D->hasUninstantiatedDefaultArg())
1160    Param->setUninstantiatedDefaultArg(D->getUninstantiatedDefaultArg());
1161  else if (Expr *Arg = D->getDefaultArg())
1162    Param->setUninstantiatedDefaultArg(Arg);
1163
1164  // Note: we don't try to instantiate function parameters until after
1165  // we've instantiated the function's type. Therefore, we don't have
1166  // to check for 'void' parameter types here.
1167  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1168  return Param;
1169}
1170
1171Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1172                                                    TemplateTypeParmDecl *D) {
1173  // TODO: don't always clone when decls are refcounted.
1174  const Type* T = D->getTypeForDecl();
1175  assert(T->isTemplateTypeParmType());
1176  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1177
1178  TemplateTypeParmDecl *Inst =
1179    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1180                                 TTPT->getDepth() - 1, TTPT->getIndex(),
1181                                 TTPT->getName(),
1182                                 D->wasDeclaredWithTypename(),
1183                                 D->isParameterPack());
1184
1185  if (D->hasDefaultArgument())
1186    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1187
1188  // Introduce this template parameter's instantiation into the instantiation
1189  // scope.
1190  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1191
1192  return Inst;
1193}
1194
1195Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1196                                                 NonTypeTemplateParmDecl *D) {
1197  // Substitute into the type of the non-type template parameter.
1198  QualType T;
1199  TypeSourceInfo *DI = D->getTypeSourceInfo();
1200  if (DI) {
1201    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1202                           D->getDeclName());
1203    if (DI) T = DI->getType();
1204  } else {
1205    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1206                          D->getDeclName());
1207    DI = 0;
1208  }
1209  if (T.isNull())
1210    return 0;
1211
1212  // Check that this type is acceptable for a non-type template parameter.
1213  bool Invalid = false;
1214  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1215  if (T.isNull()) {
1216    T = SemaRef.Context.IntTy;
1217    Invalid = true;
1218  }
1219
1220  NonTypeTemplateParmDecl *Param
1221    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1222                                      D->getDepth() - 1, D->getPosition(),
1223                                      D->getIdentifier(), T, DI);
1224  if (Invalid)
1225    Param->setInvalidDecl();
1226
1227  Param->setDefaultArgument(D->getDefaultArgument());
1228
1229  // Introduce this template parameter's instantiation into the instantiation
1230  // scope.
1231  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1232  return Param;
1233}
1234
1235Decl *
1236TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1237                                                  TemplateTemplateParmDecl *D) {
1238  // Instantiate the template parameter list of the template template parameter.
1239  TemplateParameterList *TempParams = D->getTemplateParameters();
1240  TemplateParameterList *InstParams;
1241  {
1242    // Perform the actual substitution of template parameters within a new,
1243    // local instantiation scope.
1244    Sema::LocalInstantiationScope Scope(SemaRef);
1245    InstParams = SubstTemplateParams(TempParams);
1246    if (!InstParams)
1247      return NULL;
1248  }
1249
1250  // Build the template template parameter.
1251  TemplateTemplateParmDecl *Param
1252    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1253                                       D->getDepth() - 1, D->getPosition(),
1254                                       D->getIdentifier(), InstParams);
1255  Param->setDefaultArgument(D->getDefaultArgument());
1256
1257  // Introduce this template parameter's instantiation into the instantiation
1258  // scope.
1259  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1260
1261  return Param;
1262}
1263
1264Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1265  // Using directives are never dependent, so they require no explicit
1266
1267  UsingDirectiveDecl *Inst
1268    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1269                                 D->getNamespaceKeyLocation(),
1270                                 D->getQualifierRange(), D->getQualifier(),
1271                                 D->getIdentLocation(),
1272                                 D->getNominatedNamespace(),
1273                                 D->getCommonAncestor());
1274  Owner->addDecl(Inst);
1275  return Inst;
1276}
1277
1278Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1279  // The nested name specifier is non-dependent, so no transformation
1280  // is required.
1281
1282  // We only need to do redeclaration lookups if we're in a class
1283  // scope (in fact, it's not really even possible in non-class
1284  // scopes).
1285  bool CheckRedeclaration = Owner->isRecord();
1286
1287  LookupResult Prev(SemaRef, D->getDeclName(), D->getLocation(),
1288                    Sema::LookupUsingDeclName, Sema::ForRedeclaration);
1289
1290  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1291                                       D->getLocation(),
1292                                       D->getNestedNameRange(),
1293                                       D->getUsingLocation(),
1294                                       D->getTargetNestedNameDecl(),
1295                                       D->getDeclName(),
1296                                       D->isTypeName());
1297
1298  CXXScopeSpec SS;
1299  SS.setScopeRep(D->getTargetNestedNameDecl());
1300  SS.setRange(D->getNestedNameRange());
1301
1302  if (CheckRedeclaration) {
1303    Prev.setHideTags(false);
1304    SemaRef.LookupQualifiedName(Prev, Owner);
1305
1306    // Check for invalid redeclarations.
1307    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1308                                            D->isTypeName(), SS,
1309                                            D->getLocation(), Prev))
1310      NewUD->setInvalidDecl();
1311
1312  }
1313
1314  if (!NewUD->isInvalidDecl() &&
1315      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1316                                      D->getLocation()))
1317    NewUD->setInvalidDecl();
1318
1319  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1320  NewUD->setAccess(D->getAccess());
1321  Owner->addDecl(NewUD);
1322
1323  // Don't process the shadow decls for an invalid decl.
1324  if (NewUD->isInvalidDecl())
1325    return NewUD;
1326
1327  bool isFunctionScope = Owner->isFunctionOrMethod();
1328
1329  // Process the shadow decls.
1330  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1331         I != E; ++I) {
1332    UsingShadowDecl *Shadow = *I;
1333    NamedDecl *InstTarget =
1334      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1335                                                   Shadow->getTargetDecl(),
1336                                                   TemplateArgs));
1337
1338    if (CheckRedeclaration &&
1339        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1340      continue;
1341
1342    UsingShadowDecl *InstShadow
1343      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1344    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1345
1346    if (isFunctionScope)
1347      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1348  }
1349
1350  return NewUD;
1351}
1352
1353Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1354  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1355  return 0;
1356}
1357
1358Decl * TemplateDeclInstantiator
1359    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1360  NestedNameSpecifier *NNS =
1361    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1362                                     D->getTargetNestedNameRange(),
1363                                     TemplateArgs);
1364  if (!NNS)
1365    return 0;
1366
1367  CXXScopeSpec SS;
1368  SS.setRange(D->getTargetNestedNameRange());
1369  SS.setScopeRep(NNS);
1370
1371  NamedDecl *UD =
1372    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1373                                  D->getUsingLoc(), SS, D->getLocation(),
1374                                  D->getDeclName(), 0,
1375                                  /*instantiation*/ true,
1376                                  /*typename*/ true, D->getTypenameLoc());
1377  if (UD)
1378    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1379
1380  return UD;
1381}
1382
1383Decl * TemplateDeclInstantiator
1384    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1385  NestedNameSpecifier *NNS =
1386    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1387                                     D->getTargetNestedNameRange(),
1388                                     TemplateArgs);
1389  if (!NNS)
1390    return 0;
1391
1392  CXXScopeSpec SS;
1393  SS.setRange(D->getTargetNestedNameRange());
1394  SS.setScopeRep(NNS);
1395
1396  NamedDecl *UD =
1397    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1398                                  D->getUsingLoc(), SS, D->getLocation(),
1399                                  D->getDeclName(), 0,
1400                                  /*instantiation*/ true,
1401                                  /*typename*/ false, SourceLocation());
1402  if (UD)
1403    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1404
1405  return UD;
1406}
1407
1408Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1409                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1410  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1411  if (D->isInvalidDecl())
1412    return 0;
1413
1414  return Instantiator.Visit(D);
1415}
1416
1417/// \brief Instantiates a nested template parameter list in the current
1418/// instantiation context.
1419///
1420/// \param L The parameter list to instantiate
1421///
1422/// \returns NULL if there was an error
1423TemplateParameterList *
1424TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1425  // Get errors for all the parameters before bailing out.
1426  bool Invalid = false;
1427
1428  unsigned N = L->size();
1429  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1430  ParamVector Params;
1431  Params.reserve(N);
1432  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1433       PI != PE; ++PI) {
1434    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1435    Params.push_back(D);
1436    Invalid = Invalid || !D || D->isInvalidDecl();
1437  }
1438
1439  // Clean up if we had an error.
1440  if (Invalid) {
1441    for (ParamVector::iterator PI = Params.begin(), PE = Params.end();
1442         PI != PE; ++PI)
1443      if (*PI)
1444        (*PI)->Destroy(SemaRef.Context);
1445    return NULL;
1446  }
1447
1448  TemplateParameterList *InstL
1449    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1450                                    L->getLAngleLoc(), &Params.front(), N,
1451                                    L->getRAngleLoc());
1452  return InstL;
1453}
1454
1455/// \brief Instantiate the declaration of a class template partial
1456/// specialization.
1457///
1458/// \param ClassTemplate the (instantiated) class template that is partially
1459// specialized by the instantiation of \p PartialSpec.
1460///
1461/// \param PartialSpec the (uninstantiated) class template partial
1462/// specialization that we are instantiating.
1463///
1464/// \returns true if there was an error, false otherwise.
1465bool
1466TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1467                                            ClassTemplateDecl *ClassTemplate,
1468                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1469  // Create a local instantiation scope for this class template partial
1470  // specialization, which will contain the instantiations of the template
1471  // parameters.
1472  Sema::LocalInstantiationScope Scope(SemaRef);
1473
1474  // Substitute into the template parameters of the class template partial
1475  // specialization.
1476  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1477  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1478  if (!InstParams)
1479    return true;
1480
1481  // Substitute into the template arguments of the class template partial
1482  // specialization.
1483  const TemplateArgumentLoc *PartialSpecTemplateArgs
1484    = PartialSpec->getTemplateArgsAsWritten();
1485  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1486
1487  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1488  for (unsigned I = 0; I != N; ++I) {
1489    TemplateArgumentLoc Loc;
1490    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1491      return true;
1492    InstTemplateArgs.addArgument(Loc);
1493  }
1494
1495
1496  // Check that the template argument list is well-formed for this
1497  // class template.
1498  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1499                                        InstTemplateArgs.size());
1500  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1501                                        PartialSpec->getLocation(),
1502                                        InstTemplateArgs,
1503                                        false,
1504                                        Converted))
1505    return true;
1506
1507  // Figure out where to insert this class template partial specialization
1508  // in the member template's set of class template partial specializations.
1509  llvm::FoldingSetNodeID ID;
1510  ClassTemplatePartialSpecializationDecl::Profile(ID,
1511                                                  Converted.getFlatArguments(),
1512                                                  Converted.flatSize(),
1513                                                  SemaRef.Context);
1514  void *InsertPos = 0;
1515  ClassTemplateSpecializationDecl *PrevDecl
1516    = ClassTemplate->getPartialSpecializations().FindNodeOrInsertPos(ID,
1517                                                                     InsertPos);
1518
1519  // Build the canonical type that describes the converted template
1520  // arguments of the class template partial specialization.
1521  QualType CanonType
1522    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1523                                                  Converted.getFlatArguments(),
1524                                                    Converted.flatSize());
1525
1526  // Build the fully-sugared type for this class template
1527  // specialization as the user wrote in the specialization
1528  // itself. This means that we'll pretty-print the type retrieved
1529  // from the specialization's declaration the way that the user
1530  // actually wrote the specialization, rather than formatting the
1531  // name based on the "canonical" representation used to store the
1532  // template arguments in the specialization.
1533  TypeSourceInfo *WrittenTy
1534    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1535                                                    TemplateName(ClassTemplate),
1536                                                    PartialSpec->getLocation(),
1537                                                    InstTemplateArgs,
1538                                                    CanonType);
1539
1540  if (PrevDecl) {
1541    // We've already seen a partial specialization with the same template
1542    // parameters and template arguments. This can happen, for example, when
1543    // substituting the outer template arguments ends up causing two
1544    // class template partial specializations of a member class template
1545    // to have identical forms, e.g.,
1546    //
1547    //   template<typename T, typename U>
1548    //   struct Outer {
1549    //     template<typename X, typename Y> struct Inner;
1550    //     template<typename Y> struct Inner<T, Y>;
1551    //     template<typename Y> struct Inner<U, Y>;
1552    //   };
1553    //
1554    //   Outer<int, int> outer; // error: the partial specializations of Inner
1555    //                          // have the same signature.
1556    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1557      << WrittenTy;
1558    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1559      << SemaRef.Context.getTypeDeclType(PrevDecl);
1560    return true;
1561  }
1562
1563
1564  // Create the class template partial specialization declaration.
1565  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1566    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context, Owner,
1567                                                     PartialSpec->getLocation(),
1568                                                     InstParams,
1569                                                     ClassTemplate,
1570                                                     Converted,
1571                                                     InstTemplateArgs,
1572                                                     CanonType,
1573                                                     0);
1574  // Substitute the nested name specifier, if any.
1575  if (SubstQualifier(PartialSpec, InstPartialSpec))
1576    return 0;
1577
1578  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1579  InstPartialSpec->setTypeAsWritten(WrittenTy);
1580
1581  // Add this partial specialization to the set of class template partial
1582  // specializations.
1583  ClassTemplate->getPartialSpecializations().InsertNode(InstPartialSpec,
1584                                                        InsertPos);
1585  return false;
1586}
1587
1588bool
1589Sema::CheckInstantiatedParams(llvm::SmallVectorImpl<ParmVarDecl*> &Params) {
1590  bool Invalid = false;
1591  for (unsigned i = 0, i_end = Params.size(); i != i_end; ++i)
1592    if (ParmVarDecl *PInst = Params[i]) {
1593      if (PInst->isInvalidDecl())
1594        Invalid = true;
1595      else if (PInst->getType()->isVoidType()) {
1596        Diag(PInst->getLocation(), diag::err_param_with_void_type);
1597        PInst->setInvalidDecl();
1598        Invalid = true;
1599      }
1600      else if (RequireNonAbstractType(PInst->getLocation(),
1601                                      PInst->getType(),
1602                                      diag::err_abstract_type_in_decl,
1603                                      Sema::AbstractParamType)) {
1604        PInst->setInvalidDecl();
1605        Invalid = true;
1606      }
1607    }
1608  return Invalid;
1609}
1610
1611TypeSourceInfo*
1612TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1613                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1614  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1615  assert(OldTInfo && "substituting function without type source info");
1616  assert(Params.empty() && "parameter vector is non-empty at start");
1617  TypeSourceInfo *NewTInfo = SemaRef.SubstType(OldTInfo, TemplateArgs,
1618                                               D->getTypeSpecStartLoc(),
1619                                               D->getDeclName());
1620  if (!NewTInfo)
1621    return 0;
1622
1623  // Get parameters from the new type info.
1624  TypeLoc NewTL = NewTInfo->getTypeLoc();
1625  FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1626  assert(NewProtoLoc && "Missing prototype?");
1627  for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i)
1628    Params.push_back(NewProtoLoc->getArg(i));
1629
1630  return NewTInfo;
1631}
1632
1633/// \brief Initializes the common fields of an instantiation function
1634/// declaration (New) from the corresponding fields of its template (Tmpl).
1635///
1636/// \returns true if there was an error
1637bool
1638TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1639                                                    FunctionDecl *Tmpl) {
1640  if (Tmpl->isDeleted())
1641    New->setDeleted();
1642
1643  // If we are performing substituting explicitly-specified template arguments
1644  // or deduced template arguments into a function template and we reach this
1645  // point, we are now past the point where SFINAE applies and have committed
1646  // to keeping the new function template specialization. We therefore
1647  // convert the active template instantiation for the function template
1648  // into a template instantiation for this specific function template
1649  // specialization, which is not a SFINAE context, so that we diagnose any
1650  // further errors in the declaration itself.
1651  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1652  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1653  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1654      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1655    if (FunctionTemplateDecl *FunTmpl
1656          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1657      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1658             "Deduction from the wrong function template?");
1659      (void) FunTmpl;
1660      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1661      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1662      --SemaRef.NonInstantiationEntries;
1663    }
1664  }
1665
1666  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1667  assert(Proto && "Function template without prototype?");
1668
1669  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1670      Proto->getNoReturnAttr()) {
1671    // The function has an exception specification or a "noreturn"
1672    // attribute. Substitute into each of the exception types.
1673    llvm::SmallVector<QualType, 4> Exceptions;
1674    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1675      // FIXME: Poor location information!
1676      QualType T
1677        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1678                            New->getLocation(), New->getDeclName());
1679      if (T.isNull() ||
1680          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1681        continue;
1682
1683      Exceptions.push_back(T);
1684    }
1685
1686    // Rebuild the function type
1687
1688    const FunctionProtoType *NewProto
1689      = New->getType()->getAs<FunctionProtoType>();
1690    assert(NewProto && "Template instantiation without function prototype?");
1691    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1692                                                 NewProto->arg_type_begin(),
1693                                                 NewProto->getNumArgs(),
1694                                                 NewProto->isVariadic(),
1695                                                 NewProto->getTypeQuals(),
1696                                                 Proto->hasExceptionSpec(),
1697                                                 Proto->hasAnyExceptionSpec(),
1698                                                 Exceptions.size(),
1699                                                 Exceptions.data(),
1700                                                 Proto->getNoReturnAttr(),
1701                                                 Proto->getCallConv()));
1702  }
1703
1704  return false;
1705}
1706
1707/// \brief Initializes common fields of an instantiated method
1708/// declaration (New) from the corresponding fields of its template
1709/// (Tmpl).
1710///
1711/// \returns true if there was an error
1712bool
1713TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
1714                                                  CXXMethodDecl *Tmpl) {
1715  if (InitFunctionInstantiation(New, Tmpl))
1716    return true;
1717
1718  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
1719  New->setAccess(Tmpl->getAccess());
1720  if (Tmpl->isVirtualAsWritten())
1721    Record->setMethodAsVirtual(New);
1722
1723  // FIXME: attributes
1724  // FIXME: New needs a pointer to Tmpl
1725  return false;
1726}
1727
1728/// \brief Instantiate the definition of the given function from its
1729/// template.
1730///
1731/// \param PointOfInstantiation the point at which the instantiation was
1732/// required. Note that this is not precisely a "point of instantiation"
1733/// for the function, but it's close.
1734///
1735/// \param Function the already-instantiated declaration of a
1736/// function template specialization or member function of a class template
1737/// specialization.
1738///
1739/// \param Recursive if true, recursively instantiates any functions that
1740/// are required by this instantiation.
1741///
1742/// \param DefinitionRequired if true, then we are performing an explicit
1743/// instantiation where the body of the function is required. Complain if
1744/// there is no such body.
1745void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
1746                                         FunctionDecl *Function,
1747                                         bool Recursive,
1748                                         bool DefinitionRequired) {
1749  if (Function->isInvalidDecl())
1750    return;
1751
1752  assert(!Function->getBody() && "Already instantiated!");
1753
1754  // Never instantiate an explicit specialization.
1755  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
1756    return;
1757
1758  // Find the function body that we'll be substituting.
1759  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
1760  Stmt *Pattern = 0;
1761  if (PatternDecl)
1762    Pattern = PatternDecl->getBody(PatternDecl);
1763
1764  if (!Pattern) {
1765    if (DefinitionRequired) {
1766      if (Function->getPrimaryTemplate())
1767        Diag(PointOfInstantiation,
1768             diag::err_explicit_instantiation_undefined_func_template)
1769          << Function->getPrimaryTemplate();
1770      else
1771        Diag(PointOfInstantiation,
1772             diag::err_explicit_instantiation_undefined_member)
1773          << 1 << Function->getDeclName() << Function->getDeclContext();
1774
1775      if (PatternDecl)
1776        Diag(PatternDecl->getLocation(),
1777             diag::note_explicit_instantiation_here);
1778    }
1779
1780    return;
1781  }
1782
1783  // C++0x [temp.explicit]p9:
1784  //   Except for inline functions, other explicit instantiation declarations
1785  //   have the effect of suppressing the implicit instantiation of the entity
1786  //   to which they refer.
1787  if (Function->getTemplateSpecializationKind()
1788        == TSK_ExplicitInstantiationDeclaration &&
1789      !PatternDecl->isInlined())
1790    return;
1791
1792  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
1793  if (Inst)
1794    return;
1795
1796  // If we're performing recursive template instantiation, create our own
1797  // queue of pending implicit instantiations that we will instantiate later,
1798  // while we're still within our own instantiation context.
1799  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
1800  if (Recursive)
1801    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1802
1803  ActOnStartOfFunctionDef(0, DeclPtrTy::make(Function));
1804
1805  // Introduce a new scope where local variable instantiations will be
1806  // recorded, unless we're actually a member function within a local
1807  // class, in which case we need to merge our results with the parent
1808  // scope (of the enclosing function).
1809  bool MergeWithParentScope = false;
1810  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
1811    MergeWithParentScope = Rec->isLocalClass();
1812
1813  LocalInstantiationScope Scope(*this, MergeWithParentScope);
1814
1815  // Introduce the instantiated function parameters into the local
1816  // instantiation scope.
1817  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I)
1818    Scope.InstantiatedLocal(PatternDecl->getParamDecl(I),
1819                            Function->getParamDecl(I));
1820
1821  // Enter the scope of this instantiation. We don't use
1822  // PushDeclContext because we don't have a scope.
1823  DeclContext *PreviousContext = CurContext;
1824  CurContext = Function;
1825
1826  MultiLevelTemplateArgumentList TemplateArgs =
1827    getTemplateInstantiationArgs(Function);
1828
1829  // If this is a constructor, instantiate the member initializers.
1830  if (const CXXConstructorDecl *Ctor =
1831        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
1832    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
1833                               TemplateArgs);
1834  }
1835
1836  // Instantiate the function body.
1837  OwningStmtResult Body = SubstStmt(Pattern, TemplateArgs);
1838
1839  if (Body.isInvalid())
1840    Function->setInvalidDecl();
1841
1842  ActOnFinishFunctionBody(DeclPtrTy::make(Function), move(Body),
1843                          /*IsInstantiation=*/true);
1844
1845  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
1846
1847  CurContext = PreviousContext;
1848
1849  DeclGroupRef DG(Function);
1850  Consumer.HandleTopLevelDecl(DG);
1851
1852  // This class may have local implicit instantiations that need to be
1853  // instantiation within this scope.
1854  PerformPendingImplicitInstantiations(/*LocalOnly=*/true);
1855  Scope.Exit();
1856
1857  if (Recursive) {
1858    // Instantiate any pending implicit instantiations found during the
1859    // instantiation of this template.
1860    PerformPendingImplicitInstantiations();
1861
1862    // Restore the set of pending implicit instantiations.
1863    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1864  }
1865}
1866
1867/// \brief Instantiate the definition of the given variable from its
1868/// template.
1869///
1870/// \param PointOfInstantiation the point at which the instantiation was
1871/// required. Note that this is not precisely a "point of instantiation"
1872/// for the function, but it's close.
1873///
1874/// \param Var the already-instantiated declaration of a static member
1875/// variable of a class template specialization.
1876///
1877/// \param Recursive if true, recursively instantiates any functions that
1878/// are required by this instantiation.
1879///
1880/// \param DefinitionRequired if true, then we are performing an explicit
1881/// instantiation where an out-of-line definition of the member variable
1882/// is required. Complain if there is no such definition.
1883void Sema::InstantiateStaticDataMemberDefinition(
1884                                          SourceLocation PointOfInstantiation,
1885                                                 VarDecl *Var,
1886                                                 bool Recursive,
1887                                                 bool DefinitionRequired) {
1888  if (Var->isInvalidDecl())
1889    return;
1890
1891  // Find the out-of-line definition of this static data member.
1892  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
1893  assert(Def && "This data member was not instantiated from a template?");
1894  assert(Def->isStaticDataMember() && "Not a static data member?");
1895  Def = Def->getOutOfLineDefinition();
1896
1897  if (!Def) {
1898    // We did not find an out-of-line definition of this static data member,
1899    // so we won't perform any instantiation. Rather, we rely on the user to
1900    // instantiate this definition (or provide a specialization for it) in
1901    // another translation unit.
1902    if (DefinitionRequired) {
1903      Def = Var->getInstantiatedFromStaticDataMember();
1904      Diag(PointOfInstantiation,
1905           diag::err_explicit_instantiation_undefined_member)
1906        << 2 << Var->getDeclName() << Var->getDeclContext();
1907      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
1908    }
1909
1910    return;
1911  }
1912
1913  // Never instantiate an explicit specialization.
1914  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
1915    return;
1916
1917  // C++0x [temp.explicit]p9:
1918  //   Except for inline functions, other explicit instantiation declarations
1919  //   have the effect of suppressing the implicit instantiation of the entity
1920  //   to which they refer.
1921  if (Var->getTemplateSpecializationKind()
1922        == TSK_ExplicitInstantiationDeclaration)
1923    return;
1924
1925  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
1926  if (Inst)
1927    return;
1928
1929  // If we're performing recursive template instantiation, create our own
1930  // queue of pending implicit instantiations that we will instantiate later,
1931  // while we're still within our own instantiation context.
1932  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
1933  if (Recursive)
1934    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1935
1936  // Enter the scope of this instantiation. We don't use
1937  // PushDeclContext because we don't have a scope.
1938  DeclContext *PreviousContext = CurContext;
1939  CurContext = Var->getDeclContext();
1940
1941  VarDecl *OldVar = Var;
1942  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
1943                                          getTemplateInstantiationArgs(Var)));
1944  CurContext = PreviousContext;
1945
1946  if (Var) {
1947    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
1948    assert(MSInfo && "Missing member specialization information?");
1949    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
1950                                       MSInfo->getPointOfInstantiation());
1951    DeclGroupRef DG(Var);
1952    Consumer.HandleTopLevelDecl(DG);
1953  }
1954
1955  if (Recursive) {
1956    // Instantiate any pending implicit instantiations found during the
1957    // instantiation of this template.
1958    PerformPendingImplicitInstantiations();
1959
1960    // Restore the set of pending implicit instantiations.
1961    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1962  }
1963}
1964
1965void
1966Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
1967                                 const CXXConstructorDecl *Tmpl,
1968                           const MultiLevelTemplateArgumentList &TemplateArgs) {
1969
1970  llvm::SmallVector<MemInitTy*, 4> NewInits;
1971  bool AnyErrors = false;
1972
1973  // Instantiate all the initializers.
1974  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
1975                                            InitsEnd = Tmpl->init_end();
1976       Inits != InitsEnd; ++Inits) {
1977    CXXBaseOrMemberInitializer *Init = *Inits;
1978
1979    SourceLocation LParenLoc, RParenLoc;
1980    ASTOwningVector<&ActionBase::DeleteExpr> NewArgs(*this);
1981    llvm::SmallVector<SourceLocation, 4> CommaLocs;
1982
1983    // Instantiate the initializer.
1984    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
1985                               LParenLoc, CommaLocs, NewArgs, RParenLoc)) {
1986      AnyErrors = true;
1987      continue;
1988    }
1989
1990    MemInitResult NewInit;
1991    if (Init->isBaseInitializer()) {
1992      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
1993                                            TemplateArgs,
1994                                            Init->getSourceLocation(),
1995                                            New->getDeclName());
1996      if (!BaseTInfo) {
1997        AnyErrors = true;
1998        New->setInvalidDecl();
1999        continue;
2000      }
2001
2002      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2003                                     (Expr **)NewArgs.data(),
2004                                     NewArgs.size(),
2005                                     Init->getLParenLoc(),
2006                                     Init->getRParenLoc(),
2007                                     New->getParent());
2008    } else if (Init->isMemberInitializer()) {
2009      FieldDecl *Member;
2010
2011      // Is this an anonymous union?
2012      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2013        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2014                                                      UnionInit, TemplateArgs));
2015      else
2016        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2017                                                      Init->getMember(),
2018                                                      TemplateArgs));
2019
2020      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2021                                       NewArgs.size(),
2022                                       Init->getSourceLocation(),
2023                                       Init->getLParenLoc(),
2024                                       Init->getRParenLoc());
2025    }
2026
2027    if (NewInit.isInvalid()) {
2028      AnyErrors = true;
2029      New->setInvalidDecl();
2030    } else {
2031      // FIXME: It would be nice if ASTOwningVector had a release function.
2032      NewArgs.take();
2033
2034      NewInits.push_back((MemInitTy *)NewInit.get());
2035    }
2036  }
2037
2038  // Assign all the initializers to the new constructor.
2039  ActOnMemInitializers(DeclPtrTy::make(New),
2040                       /*FIXME: ColonLoc */
2041                       SourceLocation(),
2042                       NewInits.data(), NewInits.size(),
2043                       AnyErrors);
2044}
2045
2046// TODO: this could be templated if the various decl types used the
2047// same method name.
2048static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2049                              ClassTemplateDecl *Instance) {
2050  Pattern = Pattern->getCanonicalDecl();
2051
2052  do {
2053    Instance = Instance->getCanonicalDecl();
2054    if (Pattern == Instance) return true;
2055    Instance = Instance->getInstantiatedFromMemberTemplate();
2056  } while (Instance);
2057
2058  return false;
2059}
2060
2061static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2062                              FunctionTemplateDecl *Instance) {
2063  Pattern = Pattern->getCanonicalDecl();
2064
2065  do {
2066    Instance = Instance->getCanonicalDecl();
2067    if (Pattern == Instance) return true;
2068    Instance = Instance->getInstantiatedFromMemberTemplate();
2069  } while (Instance);
2070
2071  return false;
2072}
2073
2074static bool
2075isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2076                  ClassTemplatePartialSpecializationDecl *Instance) {
2077  Pattern
2078    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2079  do {
2080    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2081                                                Instance->getCanonicalDecl());
2082    if (Pattern == Instance)
2083      return true;
2084    Instance = Instance->getInstantiatedFromMember();
2085  } while (Instance);
2086
2087  return false;
2088}
2089
2090static bool isInstantiationOf(CXXRecordDecl *Pattern,
2091                              CXXRecordDecl *Instance) {
2092  Pattern = Pattern->getCanonicalDecl();
2093
2094  do {
2095    Instance = Instance->getCanonicalDecl();
2096    if (Pattern == Instance) return true;
2097    Instance = Instance->getInstantiatedFromMemberClass();
2098  } while (Instance);
2099
2100  return false;
2101}
2102
2103static bool isInstantiationOf(FunctionDecl *Pattern,
2104                              FunctionDecl *Instance) {
2105  Pattern = Pattern->getCanonicalDecl();
2106
2107  do {
2108    Instance = Instance->getCanonicalDecl();
2109    if (Pattern == Instance) return true;
2110    Instance = Instance->getInstantiatedFromMemberFunction();
2111  } while (Instance);
2112
2113  return false;
2114}
2115
2116static bool isInstantiationOf(EnumDecl *Pattern,
2117                              EnumDecl *Instance) {
2118  Pattern = Pattern->getCanonicalDecl();
2119
2120  do {
2121    Instance = Instance->getCanonicalDecl();
2122    if (Pattern == Instance) return true;
2123    Instance = Instance->getInstantiatedFromMemberEnum();
2124  } while (Instance);
2125
2126  return false;
2127}
2128
2129static bool isInstantiationOf(UsingShadowDecl *Pattern,
2130                              UsingShadowDecl *Instance,
2131                              ASTContext &C) {
2132  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2133}
2134
2135static bool isInstantiationOf(UsingDecl *Pattern,
2136                              UsingDecl *Instance,
2137                              ASTContext &C) {
2138  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2139}
2140
2141static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2142                              UsingDecl *Instance,
2143                              ASTContext &C) {
2144  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2145}
2146
2147static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2148                              UsingDecl *Instance,
2149                              ASTContext &C) {
2150  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2151}
2152
2153static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2154                                              VarDecl *Instance) {
2155  assert(Instance->isStaticDataMember());
2156
2157  Pattern = Pattern->getCanonicalDecl();
2158
2159  do {
2160    Instance = Instance->getCanonicalDecl();
2161    if (Pattern == Instance) return true;
2162    Instance = Instance->getInstantiatedFromStaticDataMember();
2163  } while (Instance);
2164
2165  return false;
2166}
2167
2168// Other is the prospective instantiation
2169// D is the prospective pattern
2170static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2171  if (D->getKind() != Other->getKind()) {
2172    if (UnresolvedUsingTypenameDecl *UUD
2173          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2174      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2175        return isInstantiationOf(UUD, UD, Ctx);
2176      }
2177    }
2178
2179    if (UnresolvedUsingValueDecl *UUD
2180          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2181      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2182        return isInstantiationOf(UUD, UD, Ctx);
2183      }
2184    }
2185
2186    return false;
2187  }
2188
2189  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2190    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2191
2192  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2193    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2194
2195  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2196    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2197
2198  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2199    if (Var->isStaticDataMember())
2200      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2201
2202  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2203    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2204
2205  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2206    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2207
2208  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2209        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2210    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2211                             PartialSpec);
2212
2213  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2214    if (!Field->getDeclName()) {
2215      // This is an unnamed field.
2216      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2217        cast<FieldDecl>(D);
2218    }
2219  }
2220
2221  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2222    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2223
2224  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2225    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2226
2227  return D->getDeclName() && isa<NamedDecl>(Other) &&
2228    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2229}
2230
2231template<typename ForwardIterator>
2232static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2233                                      NamedDecl *D,
2234                                      ForwardIterator first,
2235                                      ForwardIterator last) {
2236  for (; first != last; ++first)
2237    if (isInstantiationOf(Ctx, D, *first))
2238      return cast<NamedDecl>(*first);
2239
2240  return 0;
2241}
2242
2243/// \brief Finds the instantiation of the given declaration context
2244/// within the current instantiation.
2245///
2246/// \returns NULL if there was an error
2247DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2248                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2249  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2250    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2251    return cast_or_null<DeclContext>(ID);
2252  } else return DC;
2253}
2254
2255/// \brief Find the instantiation of the given declaration within the
2256/// current instantiation.
2257///
2258/// This routine is intended to be used when \p D is a declaration
2259/// referenced from within a template, that needs to mapped into the
2260/// corresponding declaration within an instantiation. For example,
2261/// given:
2262///
2263/// \code
2264/// template<typename T>
2265/// struct X {
2266///   enum Kind {
2267///     KnownValue = sizeof(T)
2268///   };
2269///
2270///   bool getKind() const { return KnownValue; }
2271/// };
2272///
2273/// template struct X<int>;
2274/// \endcode
2275///
2276/// In the instantiation of X<int>::getKind(), we need to map the
2277/// EnumConstantDecl for KnownValue (which refers to
2278/// X<T>::<Kind>::KnownValue) to its instantiation
2279/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2280/// this mapping from within the instantiation of X<int>.
2281NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2282                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2283  DeclContext *ParentDC = D->getDeclContext();
2284  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2285      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2286      ParentDC->isFunctionOrMethod()) {
2287    // D is a local of some kind. Look into the map of local
2288    // declarations to their instantiations.
2289    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2290  }
2291
2292  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2293    if (!Record->isDependentContext())
2294      return D;
2295
2296    // If the RecordDecl is actually the injected-class-name or a
2297    // "templated" declaration for a class template, class template
2298    // partial specialization, or a member class of a class template,
2299    // substitute into the injected-class-name of the class template
2300    // or partial specialization to find the new DeclContext.
2301    QualType T;
2302    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2303
2304    if (ClassTemplate) {
2305      T = ClassTemplate->getInjectedClassNameSpecialization(Context);
2306    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2307                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2308      ClassTemplate = PartialSpec->getSpecializedTemplate();
2309
2310      // If we call SubstType with an InjectedClassNameType here we
2311      // can end up in an infinite loop.
2312      T = Context.getTypeDeclType(Record);
2313      assert(isa<InjectedClassNameType>(T) &&
2314             "type of partial specialization is not an InjectedClassNameType");
2315      T = cast<InjectedClassNameType>(T)->getUnderlyingType();
2316    }
2317
2318    if (!T.isNull()) {
2319      // Substitute into the injected-class-name to get the type
2320      // corresponding to the instantiation we want, which may also be
2321      // the current instantiation (if we're in a template
2322      // definition). This substitution should never fail, since we
2323      // know we can instantiate the injected-class-name or we
2324      // wouldn't have gotten to the injected-class-name!
2325
2326      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2327      // extra instantiation in the common case?
2328      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2329      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2330
2331      if (!T->isDependentType()) {
2332        assert(T->isRecordType() && "Instantiation must produce a record type");
2333        return T->getAs<RecordType>()->getDecl();
2334      }
2335
2336      // We are performing "partial" template instantiation to create
2337      // the member declarations for the members of a class template
2338      // specialization. Therefore, D is actually referring to something
2339      // in the current instantiation. Look through the current
2340      // context, which contains actual instantiations, to find the
2341      // instantiation of the "current instantiation" that D refers
2342      // to.
2343      bool SawNonDependentContext = false;
2344      for (DeclContext *DC = CurContext; !DC->isFileContext();
2345           DC = DC->getParent()) {
2346        if (ClassTemplateSpecializationDecl *Spec
2347                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2348          if (isInstantiationOf(ClassTemplate,
2349                                Spec->getSpecializedTemplate()))
2350            return Spec;
2351
2352        if (!DC->isDependentContext())
2353          SawNonDependentContext = true;
2354      }
2355
2356      // We're performing "instantiation" of a member of the current
2357      // instantiation while we are type-checking the
2358      // definition. Compute the declaration context and return that.
2359      assert(!SawNonDependentContext &&
2360             "No dependent context while instantiating record");
2361      DeclContext *DC = computeDeclContext(T);
2362      assert(DC &&
2363             "Unable to find declaration for the current instantiation");
2364      return cast<CXXRecordDecl>(DC);
2365    }
2366
2367    // Fall through to deal with other dependent record types (e.g.,
2368    // anonymous unions in class templates).
2369  }
2370
2371  if (!ParentDC->isDependentContext())
2372    return D;
2373
2374  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2375  if (!ParentDC)
2376    return 0;
2377
2378  if (ParentDC != D->getDeclContext()) {
2379    // We performed some kind of instantiation in the parent context,
2380    // so now we need to look into the instantiated parent context to
2381    // find the instantiation of the declaration D.
2382
2383    // If our context used to be dependent, we may need to instantiate
2384    // it before performing lookup into that context.
2385    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2386      if (!Spec->isDependentContext()) {
2387        QualType T = Context.getTypeDeclType(Spec);
2388        const RecordType *Tag = T->getAs<RecordType>();
2389        assert(Tag && "type of non-dependent record is not a RecordType");
2390        if (!Tag->isBeingDefined() &&
2391            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2392          return 0;
2393      }
2394    }
2395
2396    NamedDecl *Result = 0;
2397    if (D->getDeclName()) {
2398      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2399      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2400    } else {
2401      // Since we don't have a name for the entity we're looking for,
2402      // our only option is to walk through all of the declarations to
2403      // find that name. This will occur in a few cases:
2404      //
2405      //   - anonymous struct/union within a template
2406      //   - unnamed class/struct/union/enum within a template
2407      //
2408      // FIXME: Find a better way to find these instantiations!
2409      Result = findInstantiationOf(Context, D,
2410                                   ParentDC->decls_begin(),
2411                                   ParentDC->decls_end());
2412    }
2413
2414    // UsingShadowDecls can instantiate to nothing because of using hiding.
2415    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2416            cast<Decl>(ParentDC)->isInvalidDecl())
2417           && "Unable to find instantiation of declaration!");
2418
2419    D = Result;
2420  }
2421
2422  return D;
2423}
2424
2425/// \brief Performs template instantiation for all implicit template
2426/// instantiations we have seen until this point.
2427void Sema::PerformPendingImplicitInstantiations(bool LocalOnly) {
2428  while (!PendingLocalImplicitInstantiations.empty() ||
2429         (!LocalOnly && !PendingImplicitInstantiations.empty())) {
2430    PendingImplicitInstantiation Inst;
2431
2432    if (PendingLocalImplicitInstantiations.empty()) {
2433      Inst = PendingImplicitInstantiations.front();
2434      PendingImplicitInstantiations.pop_front();
2435    } else {
2436      Inst = PendingLocalImplicitInstantiations.front();
2437      PendingLocalImplicitInstantiations.pop_front();
2438    }
2439
2440    // Instantiate function definitions
2441    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2442      PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Function),
2443                                            Function->getLocation(), *this,
2444                                            Context.getSourceManager(),
2445                                           "instantiating function definition");
2446
2447      if (!Function->getBody())
2448        InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true);
2449      continue;
2450    }
2451
2452    // Instantiate static data member definitions.
2453    VarDecl *Var = cast<VarDecl>(Inst.first);
2454    assert(Var->isStaticDataMember() && "Not a static data member?");
2455
2456    // Don't try to instantiate declarations if the most recent redeclaration
2457    // is invalid.
2458    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2459      continue;
2460
2461    // Check if the most recent declaration has changed the specialization kind
2462    // and removed the need for implicit instantiation.
2463    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2464    case TSK_Undeclared:
2465      assert(false && "Cannot instantitiate an undeclared specialization.");
2466    case TSK_ExplicitInstantiationDeclaration:
2467    case TSK_ExplicitInstantiationDefinition:
2468    case TSK_ExplicitSpecialization:
2469      continue;  // No longer need implicit instantiation.
2470    case TSK_ImplicitInstantiation:
2471      break;
2472    }
2473
2474    PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Var),
2475                                          Var->getLocation(), *this,
2476                                          Context.getSourceManager(),
2477                                          "instantiating static data member "
2478                                          "definition");
2479
2480    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true);
2481  }
2482}
2483
2484void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2485                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2486  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2487         E = Pattern->ddiag_end(); I != E; ++I) {
2488    DependentDiagnostic *DD = *I;
2489
2490    switch (DD->getKind()) {
2491    case DependentDiagnostic::Access:
2492      HandleDependentAccessCheck(*DD, TemplateArgs);
2493      break;
2494    }
2495  }
2496}
2497