SemaTemplateInstantiateDecl.cpp revision 62c78d54bee499dd87f768f48b21c9b5ec15e516 
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 "clang/Sema/Sema.h"
13#include "clang/Sema/Lookup.h"
14#include "clang/Sema/Template.h"
15#include "clang/AST/ASTConsumer.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/DeclTemplate.h"
18#include "clang/AST/DeclVisitor.h"
19#include "clang/AST/DependentDiagnostic.h"
20#include "clang/AST/Expr.h"
21#include "clang/AST/ExprCXX.h"
22#include "clang/AST/TypeLoc.h"
23#include "clang/Basic/PrettyStackTrace.h"
24#include "clang/Lex/Preprocessor.h"
25
26using namespace clang;
27
28namespace {
29  class TemplateDeclInstantiator
30    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
31    Sema &SemaRef;
32    DeclContext *Owner;
33    const MultiLevelTemplateArgumentList &TemplateArgs;
34
35  public:
36    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
37                             const MultiLevelTemplateArgumentList &TemplateArgs)
38      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
39
40    // FIXME: Once we get closer to completion, replace these manually-written
41    // declarations with automatically-generated ones from
42    // clang/AST/DeclNodes.inc.
43    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
44    Decl *VisitNamespaceDecl(NamespaceDecl *D);
45    Decl *VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
46    Decl *VisitTypedefDecl(TypedefDecl *D);
47    Decl *VisitVarDecl(VarDecl *D);
48    Decl *VisitAccessSpecDecl(AccessSpecDecl *D);
49    Decl *VisitFieldDecl(FieldDecl *D);
50    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
51    Decl *VisitEnumDecl(EnumDecl *D);
52    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
53    Decl *VisitFriendDecl(FriendDecl *D);
54    Decl *VisitFunctionDecl(FunctionDecl *D,
55                            TemplateParameterList *TemplateParams = 0);
56    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
57    Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
58                             TemplateParameterList *TemplateParams = 0);
59    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
60    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
61    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
62    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
63    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
64    Decl *VisitClassTemplatePartialSpecializationDecl(
65                                    ClassTemplatePartialSpecializationDecl *D);
66    Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
67    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
68    Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
69    Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
70    Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
71    Decl *VisitUsingDecl(UsingDecl *D);
72    Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
73    Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
74    Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
75
76    // Base case. FIXME: Remove once we can instantiate everything.
77    Decl *VisitDecl(Decl *D) {
78      unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
79                                                            Diagnostic::Error,
80                                                   "cannot instantiate %0 yet");
81      SemaRef.Diag(D->getLocation(), DiagID)
82        << D->getDeclKindName();
83
84      return 0;
85    }
86
87    // Helper functions for instantiating methods.
88    TypeSourceInfo *SubstFunctionType(FunctionDecl *D,
89                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
90    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
91    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
92
93    TemplateParameterList *
94      SubstTemplateParams(TemplateParameterList *List);
95
96    bool SubstQualifier(const DeclaratorDecl *OldDecl,
97                        DeclaratorDecl *NewDecl);
98    bool SubstQualifier(const TagDecl *OldDecl,
99                        TagDecl *NewDecl);
100
101    bool InstantiateClassTemplatePartialSpecialization(
102                                              ClassTemplateDecl *ClassTemplate,
103                           ClassTemplatePartialSpecializationDecl *PartialSpec);
104  };
105}
106
107bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
108                                              DeclaratorDecl *NewDecl) {
109  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
110  if (!OldQual) return false;
111
112  SourceRange QualRange = OldDecl->getQualifierRange();
113
114  NestedNameSpecifier *NewQual
115    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
116  if (!NewQual)
117    return true;
118
119  NewDecl->setQualifierInfo(NewQual, QualRange);
120  return false;
121}
122
123bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
124                                              TagDecl *NewDecl) {
125  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
126  if (!OldQual) return false;
127
128  SourceRange QualRange = OldDecl->getQualifierRange();
129
130  NestedNameSpecifier *NewQual
131    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
132  if (!NewQual)
133    return true;
134
135  NewDecl->setQualifierInfo(NewQual, QualRange);
136  return false;
137}
138
139// FIXME: Is this still too simple?
140void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
141                            Decl *Tmpl, Decl *New) {
142  for (AttrVec::const_iterator i = Tmpl->attr_begin(), e = Tmpl->attr_end();
143       i != e; ++i) {
144    const Attr *TmplAttr = *i;
145    // FIXME: This should be generalized to more than just the AlignedAttr.
146    if (const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr)) {
147      if (Aligned->isAlignmentDependent()) {
148        // The alignment expression is not potentially evaluated.
149        EnterExpressionEvaluationContext Unevaluated(*this,
150                                                     Action::Unevaluated);
151
152        if (Aligned->isAlignmentExpr()) {
153          ExprResult Result = SubstExpr(Aligned->getAlignmentExpr(),
154                                              TemplateArgs);
155          if (!Result.isInvalid())
156            AddAlignedAttr(Aligned->getLocation(), New, Result.takeAs<Expr>());
157        }
158        else {
159          TypeSourceInfo *Result = SubstType(Aligned->getAlignmentType(),
160                                              TemplateArgs,
161                                              Aligned->getLocation(),
162                                              DeclarationName());
163          if (Result)
164            AddAlignedAttr(Aligned->getLocation(), New, Result);
165        }
166        continue;
167      }
168    }
169
170    // FIXME: Is cloning correct for all attributes?
171    Attr *NewAttr = TmplAttr->clone(Context);
172    New->addAttr(NewAttr);
173  }
174}
175
176Decl *
177TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
178  assert(false && "Translation units cannot be instantiated");
179  return D;
180}
181
182Decl *
183TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
184  assert(false && "Namespaces cannot be instantiated");
185  return D;
186}
187
188Decl *
189TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
190  NamespaceAliasDecl *Inst
191    = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
192                                 D->getNamespaceLoc(),
193                                 D->getAliasLoc(),
194                                 D->getNamespace()->getIdentifier(),
195                                 D->getQualifierRange(),
196                                 D->getQualifier(),
197                                 D->getTargetNameLoc(),
198                                 D->getNamespace());
199  Owner->addDecl(Inst);
200  return Inst;
201}
202
203Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
204  bool Invalid = false;
205  TypeSourceInfo *DI = D->getTypeSourceInfo();
206  if (DI->getType()->isDependentType() ||
207      DI->getType()->isVariablyModifiedType()) {
208    DI = SemaRef.SubstType(DI, TemplateArgs,
209                           D->getLocation(), D->getDeclName());
210    if (!DI) {
211      Invalid = true;
212      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
213    }
214  } else {
215    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
216  }
217
218  // Create the new typedef
219  TypedefDecl *Typedef
220    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
221                          D->getIdentifier(), DI);
222  if (Invalid)
223    Typedef->setInvalidDecl();
224
225  if (const TagType *TT = DI->getType()->getAs<TagType>()) {
226    TagDecl *TD = TT->getDecl();
227
228    // If the TagDecl that the TypedefDecl points to is an anonymous decl
229    // keep track of the TypedefDecl.
230    if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl())
231      TD->setTypedefForAnonDecl(Typedef);
232  }
233
234  if (TypedefDecl *Prev = D->getPreviousDeclaration()) {
235    NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
236                                                       TemplateArgs);
237    Typedef->setPreviousDeclaration(cast<TypedefDecl>(InstPrev));
238  }
239
240  SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef);
241
242  Typedef->setAccess(D->getAccess());
243  Owner->addDecl(Typedef);
244
245  return Typedef;
246}
247
248/// \brief Instantiate the arguments provided as part of initialization.
249///
250/// \returns true if an error occurred, false otherwise.
251static bool InstantiateInitializationArguments(Sema &SemaRef,
252                                               Expr **Args, unsigned NumArgs,
253                           const MultiLevelTemplateArgumentList &TemplateArgs,
254                         llvm::SmallVectorImpl<SourceLocation> &FakeCommaLocs,
255                           ASTOwningVector<Expr*> &InitArgs) {
256  for (unsigned I = 0; I != NumArgs; ++I) {
257    // When we hit the first defaulted argument, break out of the loop:
258    // we don't pass those default arguments on.
259    if (Args[I]->isDefaultArgument())
260      break;
261
262    ExprResult Arg = SemaRef.SubstExpr(Args[I], TemplateArgs);
263    if (Arg.isInvalid())
264      return true;
265
266    Expr *ArgExpr = (Expr *)Arg.get();
267    InitArgs.push_back(Arg.release());
268
269    // FIXME: We're faking all of the comma locations. Do we need them?
270    FakeCommaLocs.push_back(
271                          SemaRef.PP.getLocForEndOfToken(ArgExpr->getLocEnd()));
272  }
273
274  return false;
275}
276
277/// \brief Instantiate an initializer, breaking it into separate
278/// initialization arguments.
279///
280/// \param S The semantic analysis object.
281///
282/// \param Init The initializer to instantiate.
283///
284/// \param TemplateArgs Template arguments to be substituted into the
285/// initializer.
286///
287/// \param NewArgs Will be filled in with the instantiation arguments.
288///
289/// \returns true if an error occurred, false otherwise
290static bool InstantiateInitializer(Sema &S, Expr *Init,
291                            const MultiLevelTemplateArgumentList &TemplateArgs,
292                                   SourceLocation &LParenLoc,
293                               llvm::SmallVector<SourceLocation, 4> &CommaLocs,
294                             ASTOwningVector<Expr*> &NewArgs,
295                                   SourceLocation &RParenLoc) {
296  NewArgs.clear();
297  LParenLoc = SourceLocation();
298  RParenLoc = SourceLocation();
299
300  if (!Init)
301    return false;
302
303  if (CXXExprWithTemporaries *ExprTemp = dyn_cast<CXXExprWithTemporaries>(Init))
304    Init = ExprTemp->getSubExpr();
305
306  while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init))
307    Init = Binder->getSubExpr();
308
309  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
310    Init = ICE->getSubExprAsWritten();
311
312  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
313    LParenLoc = ParenList->getLParenLoc();
314    RParenLoc = ParenList->getRParenLoc();
315    return InstantiateInitializationArguments(S, ParenList->getExprs(),
316                                              ParenList->getNumExprs(),
317                                              TemplateArgs, CommaLocs,
318                                              NewArgs);
319  }
320
321  if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) {
322    if (!isa<CXXTemporaryObjectExpr>(Construct)) {
323      if (InstantiateInitializationArguments(S,
324                                             Construct->getArgs(),
325                                             Construct->getNumArgs(),
326                                             TemplateArgs,
327                                             CommaLocs, NewArgs))
328        return true;
329
330      // FIXME: Fake locations!
331      LParenLoc = S.PP.getLocForEndOfToken(Init->getLocStart());
332      RParenLoc = CommaLocs.empty()? LParenLoc : CommaLocs.back();
333      return false;
334    }
335  }
336
337  ExprResult Result = S.SubstExpr(Init, TemplateArgs);
338  if (Result.isInvalid())
339    return true;
340
341  NewArgs.push_back(Result.takeAs<Expr>());
342  return false;
343}
344
345Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
346  // If this is the variable for an anonymous struct or union,
347  // instantiate the anonymous struct/union type first.
348  if (const RecordType *RecordTy = D->getType()->getAs<RecordType>())
349    if (RecordTy->getDecl()->isAnonymousStructOrUnion())
350      if (!VisitCXXRecordDecl(cast<CXXRecordDecl>(RecordTy->getDecl())))
351        return 0;
352
353  // Do substitution on the type of the declaration
354  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
355                                         TemplateArgs,
356                                         D->getTypeSpecStartLoc(),
357                                         D->getDeclName());
358  if (!DI)
359    return 0;
360
361  // Build the instantiated declaration
362  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
363                                 D->getLocation(), D->getIdentifier(),
364                                 DI->getType(), DI,
365                                 D->getStorageClass(),
366                                 D->getStorageClassAsWritten());
367  Var->setThreadSpecified(D->isThreadSpecified());
368  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
369
370  // Substitute the nested name specifier, if any.
371  if (SubstQualifier(D, Var))
372    return 0;
373
374  // If we are instantiating a static data member defined
375  // out-of-line, the instantiation will have the same lexical
376  // context (which will be a namespace scope) as the template.
377  if (D->isOutOfLine())
378    Var->setLexicalDeclContext(D->getLexicalDeclContext());
379
380  Var->setAccess(D->getAccess());
381
382  if (!D->isStaticDataMember())
383    Var->setUsed(D->isUsed(false));
384
385  // FIXME: In theory, we could have a previous declaration for variables that
386  // are not static data members.
387  bool Redeclaration = false;
388  // FIXME: having to fake up a LookupResult is dumb.
389  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
390                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
391  if (D->isStaticDataMember())
392    SemaRef.LookupQualifiedName(Previous, Owner, false);
393  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
394
395  if (D->isOutOfLine()) {
396    if (!D->isStaticDataMember())
397      D->getLexicalDeclContext()->addDecl(Var);
398    Owner->makeDeclVisibleInContext(Var);
399  } else {
400    Owner->addDecl(Var);
401    if (Owner->isFunctionOrMethod())
402      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Var);
403  }
404  SemaRef.InstantiateAttrs(TemplateArgs, D, Var);
405
406  // Link instantiations of static data members back to the template from
407  // which they were instantiated.
408  if (Var->isStaticDataMember())
409    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
410                                                     TSK_ImplicitInstantiation);
411
412  if (Var->getAnyInitializer()) {
413    // We already have an initializer in the class.
414  } else if (D->getInit()) {
415    if (Var->isStaticDataMember() && !D->isOutOfLine())
416      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
417    else
418      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
419
420    // Instantiate the initializer.
421    SourceLocation LParenLoc, RParenLoc;
422    llvm::SmallVector<SourceLocation, 4> CommaLocs;
423    ASTOwningVector<Expr*> InitArgs(SemaRef);
424    if (!InstantiateInitializer(SemaRef, D->getInit(), TemplateArgs, LParenLoc,
425                                CommaLocs, InitArgs, RParenLoc)) {
426      // Attach the initializer to the declaration.
427      if (D->hasCXXDirectInitializer()) {
428        // Add the direct initializer to the declaration.
429        SemaRef.AddCXXDirectInitializerToDecl(Var,
430                                              LParenLoc,
431                                              move_arg(InitArgs),
432                                              CommaLocs.data(),
433                                              RParenLoc);
434      } else if (InitArgs.size() == 1) {
435        Expr *Init = InitArgs.take()[0];
436        SemaRef.AddInitializerToDecl(Var, Init, false);
437      } else {
438        assert(InitArgs.size() == 0);
439        SemaRef.ActOnUninitializedDecl(Var, false);
440      }
441    } else {
442      // FIXME: Not too happy about invalidating the declaration
443      // because of a bogus initializer.
444      Var->setInvalidDecl();
445    }
446
447    SemaRef.PopExpressionEvaluationContext();
448  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
449    SemaRef.ActOnUninitializedDecl(Var, false);
450
451  // Diagnose unused local variables.
452  if (!Var->isInvalidDecl() && Owner->isFunctionOrMethod() && !Var->isUsed())
453    SemaRef.DiagnoseUnusedDecl(Var);
454
455  return Var;
456}
457
458Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
459  AccessSpecDecl* AD
460    = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
461                             D->getAccessSpecifierLoc(), D->getColonLoc());
462  Owner->addHiddenDecl(AD);
463  return AD;
464}
465
466Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
467  bool Invalid = false;
468  TypeSourceInfo *DI = D->getTypeSourceInfo();
469  if (DI->getType()->isDependentType() ||
470      DI->getType()->isVariablyModifiedType())  {
471    DI = SemaRef.SubstType(DI, TemplateArgs,
472                           D->getLocation(), D->getDeclName());
473    if (!DI) {
474      DI = D->getTypeSourceInfo();
475      Invalid = true;
476    } else if (DI->getType()->isFunctionType()) {
477      // C++ [temp.arg.type]p3:
478      //   If a declaration acquires a function type through a type
479      //   dependent on a template-parameter and this causes a
480      //   declaration that does not use the syntactic form of a
481      //   function declarator to have function type, the program is
482      //   ill-formed.
483      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
484        << DI->getType();
485      Invalid = true;
486    }
487  } else {
488    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
489  }
490
491  Expr *BitWidth = D->getBitWidth();
492  if (Invalid)
493    BitWidth = 0;
494  else if (BitWidth) {
495    // The bit-width expression is not potentially evaluated.
496    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
497
498    ExprResult InstantiatedBitWidth
499      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
500    if (InstantiatedBitWidth.isInvalid()) {
501      Invalid = true;
502      BitWidth = 0;
503    } else
504      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
505  }
506
507  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
508                                            DI->getType(), DI,
509                                            cast<RecordDecl>(Owner),
510                                            D->getLocation(),
511                                            D->isMutable(),
512                                            BitWidth,
513                                            D->getTypeSpecStartLoc(),
514                                            D->getAccess(),
515                                            0);
516  if (!Field) {
517    cast<Decl>(Owner)->setInvalidDecl();
518    return 0;
519  }
520
521  SemaRef.InstantiateAttrs(TemplateArgs, D, Field);
522
523  if (Invalid)
524    Field->setInvalidDecl();
525
526  if (!Field->getDeclName()) {
527    // Keep track of where this decl came from.
528    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
529  }
530  if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
531    if (Parent->isAnonymousStructOrUnion() &&
532        Parent->getLookupContext()->isFunctionOrMethod())
533      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
534  }
535
536  Field->setImplicit(D->isImplicit());
537  Field->setAccess(D->getAccess());
538  Owner->addDecl(Field);
539
540  return Field;
541}
542
543Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
544  // Handle friend type expressions by simply substituting template
545  // parameters into the pattern type and checking the result.
546  if (TypeSourceInfo *Ty = D->getFriendType()) {
547    TypeSourceInfo *InstTy =
548      SemaRef.SubstType(Ty, TemplateArgs,
549                        D->getLocation(), DeclarationName());
550    if (!InstTy)
551      return 0;
552
553    FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getFriendLoc(), InstTy);
554    if (!FD)
555      return 0;
556
557    FD->setAccess(AS_public);
558    Owner->addDecl(FD);
559    return FD;
560  }
561
562  NamedDecl *ND = D->getFriendDecl();
563  assert(ND && "friend decl must be a decl or a type!");
564
565  // All of the Visit implementations for the various potential friend
566  // declarations have to be carefully written to work for friend
567  // objects, with the most important detail being that the target
568  // decl should almost certainly not be placed in Owner.
569  Decl *NewND = Visit(ND);
570  if (!NewND) return 0;
571
572  FriendDecl *FD =
573    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
574                       cast<NamedDecl>(NewND), D->getFriendLoc());
575  FD->setAccess(AS_public);
576  Owner->addDecl(FD);
577  return FD;
578}
579
580Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
581  Expr *AssertExpr = D->getAssertExpr();
582
583  // The expression in a static assertion is not potentially evaluated.
584  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
585
586  ExprResult InstantiatedAssertExpr
587    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
588  if (InstantiatedAssertExpr.isInvalid())
589    return 0;
590
591  ExprResult Message(D->getMessage());
592  D->getMessage()->Retain();
593  return SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
594                                              InstantiatedAssertExpr.get(),
595                                              Message.get());
596}
597
598Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
599  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
600                                    D->getLocation(), D->getIdentifier(),
601                                    D->getTagKeywordLoc(),
602                                    /*PrevDecl=*/0);
603  Enum->setInstantiationOfMemberEnum(D);
604  Enum->setAccess(D->getAccess());
605  if (SubstQualifier(D, Enum)) return 0;
606  Owner->addDecl(Enum);
607  Enum->startDefinition();
608
609  if (D->getDeclContext()->isFunctionOrMethod())
610    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
611
612  llvm::SmallVector<Decl*, 4> Enumerators;
613
614  EnumConstantDecl *LastEnumConst = 0;
615  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
616         ECEnd = D->enumerator_end();
617       EC != ECEnd; ++EC) {
618    // The specified value for the enumerator.
619    ExprResult Value = SemaRef.Owned((Expr *)0);
620    if (Expr *UninstValue = EC->getInitExpr()) {
621      // The enumerator's value expression is not potentially evaluated.
622      EnterExpressionEvaluationContext Unevaluated(SemaRef,
623                                                   Action::Unevaluated);
624
625      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
626    }
627
628    // Drop the initial value and continue.
629    bool isInvalid = false;
630    if (Value.isInvalid()) {
631      Value = SemaRef.Owned((Expr *)0);
632      isInvalid = true;
633    }
634
635    EnumConstantDecl *EnumConst
636      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
637                                  EC->getLocation(), EC->getIdentifier(),
638                                  Value.get());
639
640    if (isInvalid) {
641      if (EnumConst)
642        EnumConst->setInvalidDecl();
643      Enum->setInvalidDecl();
644    }
645
646    if (EnumConst) {
647      EnumConst->setAccess(Enum->getAccess());
648      Enum->addDecl(EnumConst);
649      Enumerators.push_back(EnumConst);
650      LastEnumConst = EnumConst;
651
652      if (D->getDeclContext()->isFunctionOrMethod()) {
653        // If the enumeration is within a function or method, record the enum
654        // constant as a local.
655        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
656      }
657    }
658  }
659
660  // FIXME: Fixup LBraceLoc and RBraceLoc
661  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
662  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
663                        Enum,
664                        Enumerators.data(), Enumerators.size(),
665                        0, 0);
666
667  return Enum;
668}
669
670Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
671  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
672  return 0;
673}
674
675Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
676  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
677
678  // Create a local instantiation scope for this class template, which
679  // will contain the instantiations of the template parameters.
680  LocalInstantiationScope Scope(SemaRef);
681  TemplateParameterList *TempParams = D->getTemplateParameters();
682  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
683  if (!InstParams)
684    return NULL;
685
686  CXXRecordDecl *Pattern = D->getTemplatedDecl();
687
688  // Instantiate the qualifier.  We have to do this first in case
689  // we're a friend declaration, because if we are then we need to put
690  // the new declaration in the appropriate context.
691  NestedNameSpecifier *Qualifier = Pattern->getQualifier();
692  if (Qualifier) {
693    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
694                                                 Pattern->getQualifierRange(),
695                                                 TemplateArgs);
696    if (!Qualifier) return 0;
697  }
698
699  CXXRecordDecl *PrevDecl = 0;
700  ClassTemplateDecl *PrevClassTemplate = 0;
701
702  // If this isn't a friend, then it's a member template, in which
703  // case we just want to build the instantiation in the
704  // specialization.  If it is a friend, we want to build it in
705  // the appropriate context.
706  DeclContext *DC = Owner;
707  if (isFriend) {
708    if (Qualifier) {
709      CXXScopeSpec SS;
710      SS.setScopeRep(Qualifier);
711      SS.setRange(Pattern->getQualifierRange());
712      DC = SemaRef.computeDeclContext(SS);
713      if (!DC) return 0;
714    } else {
715      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
716                                           Pattern->getDeclContext(),
717                                           TemplateArgs);
718    }
719
720    // Look for a previous declaration of the template in the owning
721    // context.
722    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
723                   Sema::LookupOrdinaryName, Sema::ForRedeclaration);
724    SemaRef.LookupQualifiedName(R, DC);
725
726    if (R.isSingleResult()) {
727      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
728      if (PrevClassTemplate)
729        PrevDecl = PrevClassTemplate->getTemplatedDecl();
730    }
731
732    if (!PrevClassTemplate && Qualifier) {
733      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
734        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
735        << Pattern->getQualifierRange();
736      return 0;
737    }
738
739    bool AdoptedPreviousTemplateParams = false;
740    if (PrevClassTemplate) {
741      bool Complain = true;
742
743      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
744      // template for struct std::tr1::__detail::_Map_base, where the
745      // template parameters of the friend declaration don't match the
746      // template parameters of the original declaration. In this one
747      // case, we don't complain about the ill-formed friend
748      // declaration.
749      if (isFriend && Pattern->getIdentifier() &&
750          Pattern->getIdentifier()->isStr("_Map_base") &&
751          DC->isNamespace() &&
752          cast<NamespaceDecl>(DC)->getIdentifier() &&
753          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
754        DeclContext *DCParent = DC->getParent();
755        if (DCParent->isNamespace() &&
756            cast<NamespaceDecl>(DCParent)->getIdentifier() &&
757            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
758          DeclContext *DCParent2 = DCParent->getParent();
759          if (DCParent2->isNamespace() &&
760              cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
761              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
762              DCParent2->getParent()->isTranslationUnit())
763            Complain = false;
764        }
765      }
766
767      TemplateParameterList *PrevParams
768        = PrevClassTemplate->getTemplateParameters();
769
770      // Make sure the parameter lists match.
771      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
772                                                  Complain,
773                                                  Sema::TPL_TemplateMatch)) {
774        if (Complain)
775          return 0;
776
777        AdoptedPreviousTemplateParams = true;
778        InstParams = PrevParams;
779      }
780
781      // Do some additional validation, then merge default arguments
782      // from the existing declarations.
783      if (!AdoptedPreviousTemplateParams &&
784          SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
785                                             Sema::TPC_ClassTemplate))
786        return 0;
787    }
788  }
789
790  CXXRecordDecl *RecordInst
791    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
792                            Pattern->getLocation(), Pattern->getIdentifier(),
793                            Pattern->getTagKeywordLoc(), PrevDecl,
794                            /*DelayTypeCreation=*/true);
795
796  if (Qualifier)
797    RecordInst->setQualifierInfo(Qualifier, Pattern->getQualifierRange());
798
799  ClassTemplateDecl *Inst
800    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
801                                D->getIdentifier(), InstParams, RecordInst,
802                                PrevClassTemplate);
803  RecordInst->setDescribedClassTemplate(Inst);
804
805  if (isFriend) {
806    if (PrevClassTemplate)
807      Inst->setAccess(PrevClassTemplate->getAccess());
808    else
809      Inst->setAccess(D->getAccess());
810
811    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
812    // TODO: do we want to track the instantiation progeny of this
813    // friend target decl?
814  } else {
815    Inst->setAccess(D->getAccess());
816    Inst->setInstantiatedFromMemberTemplate(D);
817  }
818
819  // Trigger creation of the type for the instantiation.
820  SemaRef.Context.getInjectedClassNameType(RecordInst,
821                                    Inst->getInjectedClassNameSpecialization());
822
823  // Finish handling of friends.
824  if (isFriend) {
825    DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
826    return Inst;
827  }
828
829  Owner->addDecl(Inst);
830
831  // Instantiate all of the partial specializations of this member class
832  // template.
833  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
834  D->getPartialSpecializations(PartialSpecs);
835  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
836    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
837
838  return Inst;
839}
840
841Decl *
842TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
843                                   ClassTemplatePartialSpecializationDecl *D) {
844  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
845
846  // Lookup the already-instantiated declaration in the instantiation
847  // of the class template and return that.
848  DeclContext::lookup_result Found
849    = Owner->lookup(ClassTemplate->getDeclName());
850  if (Found.first == Found.second)
851    return 0;
852
853  ClassTemplateDecl *InstClassTemplate
854    = dyn_cast<ClassTemplateDecl>(*Found.first);
855  if (!InstClassTemplate)
856    return 0;
857
858  return InstClassTemplate->findPartialSpecInstantiatedFromMember(D);
859}
860
861Decl *
862TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
863  // Create a local instantiation scope for this function template, which
864  // will contain the instantiations of the template parameters and then get
865  // merged with the local instantiation scope for the function template
866  // itself.
867  LocalInstantiationScope Scope(SemaRef);
868
869  TemplateParameterList *TempParams = D->getTemplateParameters();
870  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
871  if (!InstParams)
872    return NULL;
873
874  FunctionDecl *Instantiated = 0;
875  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
876    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
877                                                                 InstParams));
878  else
879    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
880                                                          D->getTemplatedDecl(),
881                                                                InstParams));
882
883  if (!Instantiated)
884    return 0;
885
886  Instantiated->setAccess(D->getAccess());
887
888  // Link the instantiated function template declaration to the function
889  // template from which it was instantiated.
890  FunctionTemplateDecl *InstTemplate
891    = Instantiated->getDescribedFunctionTemplate();
892  InstTemplate->setAccess(D->getAccess());
893  assert(InstTemplate &&
894         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
895
896  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
897
898  // Link the instantiation back to the pattern *unless* this is a
899  // non-definition friend declaration.
900  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
901      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
902    InstTemplate->setInstantiatedFromMemberTemplate(D);
903
904  // Make declarations visible in the appropriate context.
905  if (!isFriend)
906    Owner->addDecl(InstTemplate);
907
908  return InstTemplate;
909}
910
911Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
912  CXXRecordDecl *PrevDecl = 0;
913  if (D->isInjectedClassName())
914    PrevDecl = cast<CXXRecordDecl>(Owner);
915  else if (D->getPreviousDeclaration()) {
916    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
917                                                   D->getPreviousDeclaration(),
918                                                   TemplateArgs);
919    if (!Prev) return 0;
920    PrevDecl = cast<CXXRecordDecl>(Prev);
921  }
922
923  CXXRecordDecl *Record
924    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
925                            D->getLocation(), D->getIdentifier(),
926                            D->getTagKeywordLoc(), PrevDecl);
927
928  // Substitute the nested name specifier, if any.
929  if (SubstQualifier(D, Record))
930    return 0;
931
932  Record->setImplicit(D->isImplicit());
933  // FIXME: Check against AS_none is an ugly hack to work around the issue that
934  // the tag decls introduced by friend class declarations don't have an access
935  // specifier. Remove once this area of the code gets sorted out.
936  if (D->getAccess() != AS_none)
937    Record->setAccess(D->getAccess());
938  if (!D->isInjectedClassName())
939    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
940
941  // If the original function was part of a friend declaration,
942  // inherit its namespace state.
943  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
944    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
945
946  // Make sure that anonymous structs and unions are recorded.
947  if (D->isAnonymousStructOrUnion()) {
948    Record->setAnonymousStructOrUnion(true);
949    if (Record->getDeclContext()->getLookupContext()->isFunctionOrMethod())
950      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
951  }
952
953  Owner->addDecl(Record);
954  return Record;
955}
956
957/// Normal class members are of more specific types and therefore
958/// don't make it here.  This function serves two purposes:
959///   1) instantiating function templates
960///   2) substituting friend declarations
961/// FIXME: preserve function definitions in case #2
962Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
963                                       TemplateParameterList *TemplateParams) {
964  // Check whether there is already a function template specialization for
965  // this declaration.
966  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
967  void *InsertPos = 0;
968  if (FunctionTemplate && !TemplateParams) {
969    std::pair<const TemplateArgument *, unsigned> Innermost
970      = TemplateArgs.getInnermost();
971
972    FunctionDecl *SpecFunc
973      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
974                                             InsertPos);
975
976    // If we already have a function template specialization, return it.
977    if (SpecFunc)
978      return SpecFunc;
979  }
980
981  bool isFriend;
982  if (FunctionTemplate)
983    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
984  else
985    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
986
987  bool MergeWithParentScope = (TemplateParams != 0) ||
988    Owner->isFunctionOrMethod() ||
989    !(isa<Decl>(Owner) &&
990      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
991  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
992
993  llvm::SmallVector<ParmVarDecl *, 4> Params;
994  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
995  TInfo = SubstFunctionType(D, Params);
996  if (!TInfo)
997    return 0;
998  QualType T = TInfo->getType();
999
1000  NestedNameSpecifier *Qualifier = D->getQualifier();
1001  if (Qualifier) {
1002    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1003                                                 D->getQualifierRange(),
1004                                                 TemplateArgs);
1005    if (!Qualifier) return 0;
1006  }
1007
1008  // If we're instantiating a local function declaration, put the result
1009  // in the owner;  otherwise we need to find the instantiated context.
1010  DeclContext *DC;
1011  if (D->getDeclContext()->isFunctionOrMethod())
1012    DC = Owner;
1013  else if (isFriend && Qualifier) {
1014    CXXScopeSpec SS;
1015    SS.setScopeRep(Qualifier);
1016    SS.setRange(D->getQualifierRange());
1017    DC = SemaRef.computeDeclContext(SS);
1018    if (!DC) return 0;
1019  } else {
1020    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1021                                         TemplateArgs);
1022  }
1023
1024  FunctionDecl *Function =
1025      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
1026                           D->getDeclName(), T, TInfo,
1027                           D->getStorageClass(), D->getStorageClassAsWritten(),
1028                           D->isInlineSpecified(), D->hasWrittenPrototype());
1029
1030  if (Qualifier)
1031    Function->setQualifierInfo(Qualifier, D->getQualifierRange());
1032
1033  DeclContext *LexicalDC = Owner;
1034  if (!isFriend && D->isOutOfLine()) {
1035    assert(D->getDeclContext()->isFileContext());
1036    LexicalDC = D->getDeclContext();
1037  }
1038
1039  Function->setLexicalDeclContext(LexicalDC);
1040
1041  // Attach the parameters
1042  for (unsigned P = 0; P < Params.size(); ++P)
1043    Params[P]->setOwningFunction(Function);
1044  Function->setParams(Params.data(), Params.size());
1045
1046  SourceLocation InstantiateAtPOI;
1047  if (TemplateParams) {
1048    // Our resulting instantiation is actually a function template, since we
1049    // are substituting only the outer template parameters. For example, given
1050    //
1051    //   template<typename T>
1052    //   struct X {
1053    //     template<typename U> friend void f(T, U);
1054    //   };
1055    //
1056    //   X<int> x;
1057    //
1058    // We are instantiating the friend function template "f" within X<int>,
1059    // which means substituting int for T, but leaving "f" as a friend function
1060    // template.
1061    // Build the function template itself.
1062    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1063                                                    Function->getLocation(),
1064                                                    Function->getDeclName(),
1065                                                    TemplateParams, Function);
1066    Function->setDescribedFunctionTemplate(FunctionTemplate);
1067
1068    FunctionTemplate->setLexicalDeclContext(LexicalDC);
1069
1070    if (isFriend && D->isThisDeclarationADefinition()) {
1071      // TODO: should we remember this connection regardless of whether
1072      // the friend declaration provided a body?
1073      FunctionTemplate->setInstantiatedFromMemberTemplate(
1074                                           D->getDescribedFunctionTemplate());
1075    }
1076  } else if (FunctionTemplate) {
1077    // Record this function template specialization.
1078    std::pair<const TemplateArgument *, unsigned> Innermost
1079      = TemplateArgs.getInnermost();
1080    Function->setFunctionTemplateSpecialization(FunctionTemplate,
1081                  new (SemaRef.Context) TemplateArgumentList(SemaRef.Context,
1082                                                             Innermost.first,
1083                                                             Innermost.second),
1084                                                InsertPos);
1085  } else if (isFriend && D->isThisDeclarationADefinition()) {
1086    // TODO: should we remember this connection regardless of whether
1087    // the friend declaration provided a body?
1088    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1089  }
1090
1091  if (InitFunctionInstantiation(Function, D))
1092    Function->setInvalidDecl();
1093
1094  bool Redeclaration = false;
1095  bool OverloadableAttrRequired = false;
1096  bool isExplicitSpecialization = false;
1097
1098  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1099                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1100
1101  if (DependentFunctionTemplateSpecializationInfo *Info
1102        = D->getDependentSpecializationInfo()) {
1103    assert(isFriend && "non-friend has dependent specialization info?");
1104
1105    // This needs to be set now for future sanity.
1106    Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1107
1108    // Instantiate the explicit template arguments.
1109    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1110                                          Info->getRAngleLoc());
1111    for (unsigned I = 0, E = Info->getNumTemplateArgs(); I != E; ++I) {
1112      TemplateArgumentLoc Loc;
1113      if (SemaRef.Subst(Info->getTemplateArg(I), Loc, TemplateArgs))
1114        return 0;
1115
1116      ExplicitArgs.addArgument(Loc);
1117    }
1118
1119    // Map the candidate templates to their instantiations.
1120    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1121      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1122                                                Info->getTemplate(I),
1123                                                TemplateArgs);
1124      if (!Temp) return 0;
1125
1126      Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1127    }
1128
1129    if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1130                                                    &ExplicitArgs,
1131                                                    Previous))
1132      Function->setInvalidDecl();
1133
1134    isExplicitSpecialization = true;
1135
1136  } else if (TemplateParams || !FunctionTemplate) {
1137    // Look only into the namespace where the friend would be declared to
1138    // find a previous declaration. This is the innermost enclosing namespace,
1139    // as described in ActOnFriendFunctionDecl.
1140    SemaRef.LookupQualifiedName(Previous, DC);
1141
1142    // In C++, the previous declaration we find might be a tag type
1143    // (class or enum). In this case, the new declaration will hide the
1144    // tag type. Note that this does does not apply if we're declaring a
1145    // typedef (C++ [dcl.typedef]p4).
1146    if (Previous.isSingleTagDecl())
1147      Previous.clear();
1148  }
1149
1150  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1151                                   isExplicitSpecialization, Redeclaration,
1152                                   /*FIXME:*/OverloadableAttrRequired);
1153
1154  NamedDecl *PrincipalDecl = (TemplateParams
1155                              ? cast<NamedDecl>(FunctionTemplate)
1156                              : Function);
1157
1158  // If the original function was part of a friend declaration,
1159  // inherit its namespace state and add it to the owner.
1160  if (isFriend) {
1161    NamedDecl *PrevDecl;
1162    if (TemplateParams)
1163      PrevDecl = FunctionTemplate->getPreviousDeclaration();
1164    else
1165      PrevDecl = Function->getPreviousDeclaration();
1166
1167    PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0);
1168    DC->makeDeclVisibleInContext(PrincipalDecl, /*Recoverable=*/ false);
1169
1170    if (!SemaRef.getLangOptions().CPlusPlus0x &&
1171        D->isThisDeclarationADefinition()) {
1172      // Check for a function body.
1173      const FunctionDecl *Definition = 0;
1174      if (Function->hasBody(Definition) &&
1175          Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1176        SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1177          << Function->getDeclName();
1178        SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1179        Function->setInvalidDecl();
1180      }
1181      // Check for redefinitions due to other instantiations of this or
1182      // a similar friend function.
1183      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1184                                           REnd = Function->redecls_end();
1185                R != REnd; ++R) {
1186        if (*R != Function &&
1187            ((*R)->getFriendObjectKind() != Decl::FOK_None)) {
1188          if (const FunctionDecl *RPattern
1189              = (*R)->getTemplateInstantiationPattern())
1190            if (RPattern->hasBody(RPattern)) {
1191              SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1192                << Function->getDeclName();
1193              SemaRef.Diag((*R)->getLocation(), diag::note_previous_definition);
1194              Function->setInvalidDecl();
1195              break;
1196            }
1197        }
1198      }
1199    }
1200
1201  }
1202
1203  if (Function->isOverloadedOperator() && !DC->isRecord() &&
1204      PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1205    PrincipalDecl->setNonMemberOperator();
1206
1207  return Function;
1208}
1209
1210Decl *
1211TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1212                                      TemplateParameterList *TemplateParams) {
1213  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1214  void *InsertPos = 0;
1215  if (FunctionTemplate && !TemplateParams) {
1216    // We are creating a function template specialization from a function
1217    // template. Check whether there is already a function template
1218    // specialization for this particular set of template arguments.
1219    std::pair<const TemplateArgument *, unsigned> Innermost
1220      = TemplateArgs.getInnermost();
1221
1222    FunctionDecl *SpecFunc
1223      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
1224                                             InsertPos);
1225
1226    // If we already have a function template specialization, return it.
1227    if (SpecFunc)
1228      return SpecFunc;
1229  }
1230
1231  bool isFriend;
1232  if (FunctionTemplate)
1233    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1234  else
1235    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1236
1237  bool MergeWithParentScope = (TemplateParams != 0) ||
1238    !(isa<Decl>(Owner) &&
1239      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1240  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1241
1242  llvm::SmallVector<ParmVarDecl *, 4> Params;
1243  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1244  TInfo = SubstFunctionType(D, Params);
1245  if (!TInfo)
1246    return 0;
1247  QualType T = TInfo->getType();
1248
1249  // \brief If the type of this function is not *directly* a function
1250  // type, then we're instantiating the a function that was declared
1251  // via a typedef, e.g.,
1252  //
1253  //   typedef int functype(int, int);
1254  //   functype func;
1255  //
1256  // In this case, we'll just go instantiate the ParmVarDecls that we
1257  // synthesized in the method declaration.
1258  if (!isa<FunctionProtoType>(T)) {
1259    assert(!Params.size() && "Instantiating type could not yield parameters");
1260    for (unsigned I = 0, N = D->getNumParams(); I != N; ++I) {
1261      ParmVarDecl *P = SemaRef.SubstParmVarDecl(D->getParamDecl(I),
1262                                                TemplateArgs);
1263      if (!P)
1264        return 0;
1265
1266      Params.push_back(P);
1267    }
1268  }
1269
1270  NestedNameSpecifier *Qualifier = D->getQualifier();
1271  if (Qualifier) {
1272    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1273                                                 D->getQualifierRange(),
1274                                                 TemplateArgs);
1275    if (!Qualifier) return 0;
1276  }
1277
1278  DeclContext *DC = Owner;
1279  if (isFriend) {
1280    if (Qualifier) {
1281      CXXScopeSpec SS;
1282      SS.setScopeRep(Qualifier);
1283      SS.setRange(D->getQualifierRange());
1284      DC = SemaRef.computeDeclContext(SS);
1285    } else {
1286      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1287                                           D->getDeclContext(),
1288                                           TemplateArgs);
1289    }
1290    if (!DC) return 0;
1291  }
1292
1293  // Build the instantiated method declaration.
1294  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1295  CXXMethodDecl *Method = 0;
1296
1297  DeclarationNameInfo NameInfo
1298    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1299  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1300    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1301                                        NameInfo, T, TInfo,
1302                                        Constructor->isExplicit(),
1303                                        Constructor->isInlineSpecified(),
1304                                        false);
1305  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1306    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1307                                       NameInfo, T,
1308                                       Destructor->isInlineSpecified(),
1309                                       false);
1310  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1311    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1312                                       NameInfo, T, TInfo,
1313                                       Conversion->isInlineSpecified(),
1314                                       Conversion->isExplicit());
1315  } else {
1316    Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1317                                   NameInfo, T, TInfo,
1318                                   D->isStatic(),
1319                                   D->getStorageClassAsWritten(),
1320                                   D->isInlineSpecified());
1321  }
1322
1323  if (Qualifier)
1324    Method->setQualifierInfo(Qualifier, D->getQualifierRange());
1325
1326  if (TemplateParams) {
1327    // Our resulting instantiation is actually a function template, since we
1328    // are substituting only the outer template parameters. For example, given
1329    //
1330    //   template<typename T>
1331    //   struct X {
1332    //     template<typename U> void f(T, U);
1333    //   };
1334    //
1335    //   X<int> x;
1336    //
1337    // We are instantiating the member template "f" within X<int>, which means
1338    // substituting int for T, but leaving "f" as a member function template.
1339    // Build the function template itself.
1340    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1341                                                    Method->getLocation(),
1342                                                    Method->getDeclName(),
1343                                                    TemplateParams, Method);
1344    if (isFriend) {
1345      FunctionTemplate->setLexicalDeclContext(Owner);
1346      FunctionTemplate->setObjectOfFriendDecl(true);
1347    } else if (D->isOutOfLine())
1348      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1349    Method->setDescribedFunctionTemplate(FunctionTemplate);
1350  } else if (FunctionTemplate) {
1351    // Record this function template specialization.
1352    std::pair<const TemplateArgument *, unsigned> Innermost
1353      = TemplateArgs.getInnermost();
1354    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1355                    new (SemaRef.Context) TemplateArgumentList(SemaRef.Context,
1356                                                              Innermost.first,
1357                                                              Innermost.second),
1358                                              InsertPos);
1359  } else if (!isFriend) {
1360    // Record that this is an instantiation of a member function.
1361    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1362  }
1363
1364  // If we are instantiating a member function defined
1365  // out-of-line, the instantiation will have the same lexical
1366  // context (which will be a namespace scope) as the template.
1367  if (isFriend) {
1368    Method->setLexicalDeclContext(Owner);
1369    Method->setObjectOfFriendDecl(true);
1370  } else if (D->isOutOfLine())
1371    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1372
1373  // Attach the parameters
1374  for (unsigned P = 0; P < Params.size(); ++P)
1375    Params[P]->setOwningFunction(Method);
1376  Method->setParams(Params.data(), Params.size());
1377
1378  if (InitMethodInstantiation(Method, D))
1379    Method->setInvalidDecl();
1380
1381  LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
1382                        Sema::ForRedeclaration);
1383
1384  if (!FunctionTemplate || TemplateParams || isFriend) {
1385    SemaRef.LookupQualifiedName(Previous, Record);
1386
1387    // In C++, the previous declaration we find might be a tag type
1388    // (class or enum). In this case, the new declaration will hide the
1389    // tag type. Note that this does does not apply if we're declaring a
1390    // typedef (C++ [dcl.typedef]p4).
1391    if (Previous.isSingleTagDecl())
1392      Previous.clear();
1393  }
1394
1395  bool Redeclaration = false;
1396  bool OverloadableAttrRequired = false;
1397  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1398                                   /*FIXME:*/OverloadableAttrRequired);
1399
1400  if (D->isPure())
1401    SemaRef.CheckPureMethod(Method, SourceRange());
1402
1403  Method->setAccess(D->getAccess());
1404
1405  if (FunctionTemplate) {
1406    // If there's a function template, let our caller handle it.
1407  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1408    // Don't hide a (potentially) valid declaration with an invalid one.
1409  } else {
1410    NamedDecl *DeclToAdd = (TemplateParams
1411                            ? cast<NamedDecl>(FunctionTemplate)
1412                            : Method);
1413    if (isFriend)
1414      Record->makeDeclVisibleInContext(DeclToAdd);
1415    else
1416      Owner->addDecl(DeclToAdd);
1417  }
1418
1419  return Method;
1420}
1421
1422Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1423  return VisitCXXMethodDecl(D);
1424}
1425
1426Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1427  return VisitCXXMethodDecl(D);
1428}
1429
1430Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1431  return VisitCXXMethodDecl(D);
1432}
1433
1434ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1435  return SemaRef.SubstParmVarDecl(D, TemplateArgs);
1436}
1437
1438Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1439                                                    TemplateTypeParmDecl *D) {
1440  // TODO: don't always clone when decls are refcounted.
1441  const Type* T = D->getTypeForDecl();
1442  assert(T->isTemplateTypeParmType());
1443  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1444
1445  TemplateTypeParmDecl *Inst =
1446    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1447                                 TTPT->getDepth() - 1, TTPT->getIndex(),
1448                                 TTPT->getName(),
1449                                 D->wasDeclaredWithTypename(),
1450                                 D->isParameterPack());
1451
1452  if (D->hasDefaultArgument())
1453    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1454
1455  // Introduce this template parameter's instantiation into the instantiation
1456  // scope.
1457  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1458
1459  return Inst;
1460}
1461
1462Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1463                                                 NonTypeTemplateParmDecl *D) {
1464  // Substitute into the type of the non-type template parameter.
1465  QualType T;
1466  TypeSourceInfo *DI = D->getTypeSourceInfo();
1467  if (DI) {
1468    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1469                           D->getDeclName());
1470    if (DI) T = DI->getType();
1471  } else {
1472    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1473                          D->getDeclName());
1474    DI = 0;
1475  }
1476  if (T.isNull())
1477    return 0;
1478
1479  // Check that this type is acceptable for a non-type template parameter.
1480  bool Invalid = false;
1481  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1482  if (T.isNull()) {
1483    T = SemaRef.Context.IntTy;
1484    Invalid = true;
1485  }
1486
1487  NonTypeTemplateParmDecl *Param
1488    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1489                                      D->getDepth() - 1, D->getPosition(),
1490                                      D->getIdentifier(), T, DI);
1491  if (Invalid)
1492    Param->setInvalidDecl();
1493
1494  Param->setDefaultArgument(D->getDefaultArgument(), false);
1495
1496  // Introduce this template parameter's instantiation into the instantiation
1497  // scope.
1498  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1499  return Param;
1500}
1501
1502Decl *
1503TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1504                                                  TemplateTemplateParmDecl *D) {
1505  // Instantiate the template parameter list of the template template parameter.
1506  TemplateParameterList *TempParams = D->getTemplateParameters();
1507  TemplateParameterList *InstParams;
1508  {
1509    // Perform the actual substitution of template parameters within a new,
1510    // local instantiation scope.
1511    LocalInstantiationScope Scope(SemaRef);
1512    InstParams = SubstTemplateParams(TempParams);
1513    if (!InstParams)
1514      return NULL;
1515  }
1516
1517  // Build the template template parameter.
1518  TemplateTemplateParmDecl *Param
1519    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1520                                       D->getDepth() - 1, D->getPosition(),
1521                                       D->getIdentifier(), InstParams);
1522  Param->setDefaultArgument(D->getDefaultArgument(), false);
1523
1524  // Introduce this template parameter's instantiation into the instantiation
1525  // scope.
1526  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1527
1528  return Param;
1529}
1530
1531Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1532  // Using directives are never dependent, so they require no explicit
1533
1534  UsingDirectiveDecl *Inst
1535    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1536                                 D->getNamespaceKeyLocation(),
1537                                 D->getQualifierRange(), D->getQualifier(),
1538                                 D->getIdentLocation(),
1539                                 D->getNominatedNamespace(),
1540                                 D->getCommonAncestor());
1541  Owner->addDecl(Inst);
1542  return Inst;
1543}
1544
1545Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1546  // The nested name specifier is non-dependent, so no transformation
1547  // is required. The same holds for the name info.
1548  DeclarationNameInfo NameInfo = D->getNameInfo();
1549
1550  // We only need to do redeclaration lookups if we're in a class
1551  // scope (in fact, it's not really even possible in non-class
1552  // scopes).
1553  bool CheckRedeclaration = Owner->isRecord();
1554
1555  LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
1556                    Sema::ForRedeclaration);
1557
1558  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1559                                       D->getNestedNameRange(),
1560                                       D->getUsingLocation(),
1561                                       D->getTargetNestedNameDecl(),
1562                                       NameInfo,
1563                                       D->isTypeName());
1564
1565  CXXScopeSpec SS;
1566  SS.setScopeRep(D->getTargetNestedNameDecl());
1567  SS.setRange(D->getNestedNameRange());
1568
1569  if (CheckRedeclaration) {
1570    Prev.setHideTags(false);
1571    SemaRef.LookupQualifiedName(Prev, Owner);
1572
1573    // Check for invalid redeclarations.
1574    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1575                                            D->isTypeName(), SS,
1576                                            D->getLocation(), Prev))
1577      NewUD->setInvalidDecl();
1578
1579  }
1580
1581  if (!NewUD->isInvalidDecl() &&
1582      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1583                                      D->getLocation()))
1584    NewUD->setInvalidDecl();
1585
1586  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1587  NewUD->setAccess(D->getAccess());
1588  Owner->addDecl(NewUD);
1589
1590  // Don't process the shadow decls for an invalid decl.
1591  if (NewUD->isInvalidDecl())
1592    return NewUD;
1593
1594  bool isFunctionScope = Owner->isFunctionOrMethod();
1595
1596  // Process the shadow decls.
1597  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1598         I != E; ++I) {
1599    UsingShadowDecl *Shadow = *I;
1600    NamedDecl *InstTarget =
1601      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1602                                                   Shadow->getTargetDecl(),
1603                                                   TemplateArgs));
1604
1605    if (CheckRedeclaration &&
1606        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1607      continue;
1608
1609    UsingShadowDecl *InstShadow
1610      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1611    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1612
1613    if (isFunctionScope)
1614      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1615  }
1616
1617  return NewUD;
1618}
1619
1620Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1621  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1622  return 0;
1623}
1624
1625Decl * TemplateDeclInstantiator
1626    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1627  NestedNameSpecifier *NNS =
1628    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1629                                     D->getTargetNestedNameRange(),
1630                                     TemplateArgs);
1631  if (!NNS)
1632    return 0;
1633
1634  CXXScopeSpec SS;
1635  SS.setRange(D->getTargetNestedNameRange());
1636  SS.setScopeRep(NNS);
1637
1638  // Since NameInfo refers to a typename, it cannot be a C++ special name.
1639  // Hence, no tranformation is required for it.
1640  DeclarationNameInfo NameInfo(D->getDeclName(), D->getLocation());
1641  NamedDecl *UD =
1642    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1643                                  D->getUsingLoc(), SS, NameInfo, 0,
1644                                  /*instantiation*/ true,
1645                                  /*typename*/ true, D->getTypenameLoc());
1646  if (UD)
1647    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1648
1649  return UD;
1650}
1651
1652Decl * TemplateDeclInstantiator
1653    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1654  NestedNameSpecifier *NNS =
1655    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1656                                     D->getTargetNestedNameRange(),
1657                                     TemplateArgs);
1658  if (!NNS)
1659    return 0;
1660
1661  CXXScopeSpec SS;
1662  SS.setRange(D->getTargetNestedNameRange());
1663  SS.setScopeRep(NNS);
1664
1665  DeclarationNameInfo NameInfo
1666    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1667
1668  NamedDecl *UD =
1669    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1670                                  D->getUsingLoc(), SS, NameInfo, 0,
1671                                  /*instantiation*/ true,
1672                                  /*typename*/ false, SourceLocation());
1673  if (UD)
1674    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1675
1676  return UD;
1677}
1678
1679Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1680                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1681  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1682  if (D->isInvalidDecl())
1683    return 0;
1684
1685  return Instantiator.Visit(D);
1686}
1687
1688/// \brief Instantiates a nested template parameter list in the current
1689/// instantiation context.
1690///
1691/// \param L The parameter list to instantiate
1692///
1693/// \returns NULL if there was an error
1694TemplateParameterList *
1695TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1696  // Get errors for all the parameters before bailing out.
1697  bool Invalid = false;
1698
1699  unsigned N = L->size();
1700  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1701  ParamVector Params;
1702  Params.reserve(N);
1703  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1704       PI != PE; ++PI) {
1705    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1706    Params.push_back(D);
1707    Invalid = Invalid || !D || D->isInvalidDecl();
1708  }
1709
1710  // Clean up if we had an error.
1711  if (Invalid)
1712    return NULL;
1713
1714  TemplateParameterList *InstL
1715    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1716                                    L->getLAngleLoc(), &Params.front(), N,
1717                                    L->getRAngleLoc());
1718  return InstL;
1719}
1720
1721/// \brief Instantiate the declaration of a class template partial
1722/// specialization.
1723///
1724/// \param ClassTemplate the (instantiated) class template that is partially
1725// specialized by the instantiation of \p PartialSpec.
1726///
1727/// \param PartialSpec the (uninstantiated) class template partial
1728/// specialization that we are instantiating.
1729///
1730/// \returns true if there was an error, false otherwise.
1731bool
1732TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1733                                            ClassTemplateDecl *ClassTemplate,
1734                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1735  // Create a local instantiation scope for this class template partial
1736  // specialization, which will contain the instantiations of the template
1737  // parameters.
1738  LocalInstantiationScope Scope(SemaRef);
1739
1740  // Substitute into the template parameters of the class template partial
1741  // specialization.
1742  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1743  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1744  if (!InstParams)
1745    return true;
1746
1747  // Substitute into the template arguments of the class template partial
1748  // specialization.
1749  const TemplateArgumentLoc *PartialSpecTemplateArgs
1750    = PartialSpec->getTemplateArgsAsWritten();
1751  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1752
1753  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1754  for (unsigned I = 0; I != N; ++I) {
1755    TemplateArgumentLoc Loc;
1756    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1757      return true;
1758    InstTemplateArgs.addArgument(Loc);
1759  }
1760
1761
1762  // Check that the template argument list is well-formed for this
1763  // class template.
1764  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1765                                        InstTemplateArgs.size());
1766  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1767                                        PartialSpec->getLocation(),
1768                                        InstTemplateArgs,
1769                                        false,
1770                                        Converted))
1771    return true;
1772
1773  // Figure out where to insert this class template partial specialization
1774  // in the member template's set of class template partial specializations.
1775  void *InsertPos = 0;
1776  ClassTemplateSpecializationDecl *PrevDecl
1777    = ClassTemplate->findPartialSpecialization(Converted.getFlatArguments(),
1778                                                Converted.flatSize(), InsertPos);
1779
1780  // Build the canonical type that describes the converted template
1781  // arguments of the class template partial specialization.
1782  QualType CanonType
1783    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1784                                                  Converted.getFlatArguments(),
1785                                                    Converted.flatSize());
1786
1787  // Build the fully-sugared type for this class template
1788  // specialization as the user wrote in the specialization
1789  // itself. This means that we'll pretty-print the type retrieved
1790  // from the specialization's declaration the way that the user
1791  // actually wrote the specialization, rather than formatting the
1792  // name based on the "canonical" representation used to store the
1793  // template arguments in the specialization.
1794  TypeSourceInfo *WrittenTy
1795    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1796                                                    TemplateName(ClassTemplate),
1797                                                    PartialSpec->getLocation(),
1798                                                    InstTemplateArgs,
1799                                                    CanonType);
1800
1801  if (PrevDecl) {
1802    // We've already seen a partial specialization with the same template
1803    // parameters and template arguments. This can happen, for example, when
1804    // substituting the outer template arguments ends up causing two
1805    // class template partial specializations of a member class template
1806    // to have identical forms, e.g.,
1807    //
1808    //   template<typename T, typename U>
1809    //   struct Outer {
1810    //     template<typename X, typename Y> struct Inner;
1811    //     template<typename Y> struct Inner<T, Y>;
1812    //     template<typename Y> struct Inner<U, Y>;
1813    //   };
1814    //
1815    //   Outer<int, int> outer; // error: the partial specializations of Inner
1816    //                          // have the same signature.
1817    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1818      << WrittenTy;
1819    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1820      << SemaRef.Context.getTypeDeclType(PrevDecl);
1821    return true;
1822  }
1823
1824
1825  // Create the class template partial specialization declaration.
1826  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1827    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
1828                                                     PartialSpec->getTagKind(),
1829                                                     Owner,
1830                                                     PartialSpec->getLocation(),
1831                                                     InstParams,
1832                                                     ClassTemplate,
1833                                                     Converted,
1834                                                     InstTemplateArgs,
1835                                                     CanonType,
1836                                                     0,
1837                             ClassTemplate->getNextPartialSpecSequenceNumber());
1838  // Substitute the nested name specifier, if any.
1839  if (SubstQualifier(PartialSpec, InstPartialSpec))
1840    return 0;
1841
1842  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1843  InstPartialSpec->setTypeAsWritten(WrittenTy);
1844
1845  // Add this partial specialization to the set of class template partial
1846  // specializations.
1847  ClassTemplate->AddPartialSpecialization(InstPartialSpec, InsertPos);
1848  return false;
1849}
1850
1851TypeSourceInfo*
1852TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1853                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1854  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1855  assert(OldTInfo && "substituting function without type source info");
1856  assert(Params.empty() && "parameter vector is non-empty at start");
1857  TypeSourceInfo *NewTInfo
1858    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
1859                                    D->getTypeSpecStartLoc(),
1860                                    D->getDeclName());
1861  if (!NewTInfo)
1862    return 0;
1863
1864  if (NewTInfo != OldTInfo) {
1865    // Get parameters from the new type info.
1866    TypeLoc OldTL = OldTInfo->getTypeLoc();
1867    if (FunctionProtoTypeLoc *OldProtoLoc
1868                                  = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1869      TypeLoc NewTL = NewTInfo->getTypeLoc();
1870      FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1871      assert(NewProtoLoc && "Missing prototype?");
1872      for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i) {
1873        // FIXME: Variadic templates will break this.
1874        Params.push_back(NewProtoLoc->getArg(i));
1875        SemaRef.CurrentInstantiationScope->InstantiatedLocal(
1876                                                        OldProtoLoc->getArg(i),
1877                                                        NewProtoLoc->getArg(i));
1878      }
1879    }
1880  } else {
1881    // The function type itself was not dependent and therefore no
1882    // substitution occurred. However, we still need to instantiate
1883    // the function parameters themselves.
1884    TypeLoc OldTL = OldTInfo->getTypeLoc();
1885    if (FunctionProtoTypeLoc *OldProtoLoc
1886                                    = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1887      for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
1888        ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
1889        if (!Parm)
1890          return 0;
1891        Params.push_back(Parm);
1892      }
1893    }
1894  }
1895  return NewTInfo;
1896}
1897
1898/// \brief Initializes the common fields of an instantiation function
1899/// declaration (New) from the corresponding fields of its template (Tmpl).
1900///
1901/// \returns true if there was an error
1902bool
1903TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1904                                                    FunctionDecl *Tmpl) {
1905  if (Tmpl->isDeleted())
1906    New->setDeleted();
1907
1908  // If we are performing substituting explicitly-specified template arguments
1909  // or deduced template arguments into a function template and we reach this
1910  // point, we are now past the point where SFINAE applies and have committed
1911  // to keeping the new function template specialization. We therefore
1912  // convert the active template instantiation for the function template
1913  // into a template instantiation for this specific function template
1914  // specialization, which is not a SFINAE context, so that we diagnose any
1915  // further errors in the declaration itself.
1916  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1917  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1918  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1919      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1920    if (FunctionTemplateDecl *FunTmpl
1921          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1922      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1923             "Deduction from the wrong function template?");
1924      (void) FunTmpl;
1925      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1926      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1927      --SemaRef.NonInstantiationEntries;
1928    }
1929  }
1930
1931  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1932  assert(Proto && "Function template without prototype?");
1933
1934  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1935      Proto->getNoReturnAttr()) {
1936    // The function has an exception specification or a "noreturn"
1937    // attribute. Substitute into each of the exception types.
1938    llvm::SmallVector<QualType, 4> Exceptions;
1939    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1940      // FIXME: Poor location information!
1941      QualType T
1942        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1943                            New->getLocation(), New->getDeclName());
1944      if (T.isNull() ||
1945          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1946        continue;
1947
1948      Exceptions.push_back(T);
1949    }
1950
1951    // Rebuild the function type
1952
1953    const FunctionProtoType *NewProto
1954      = New->getType()->getAs<FunctionProtoType>();
1955    assert(NewProto && "Template instantiation without function prototype?");
1956    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1957                                                 NewProto->arg_type_begin(),
1958                                                 NewProto->getNumArgs(),
1959                                                 NewProto->isVariadic(),
1960                                                 NewProto->getTypeQuals(),
1961                                                 Proto->hasExceptionSpec(),
1962                                                 Proto->hasAnyExceptionSpec(),
1963                                                 Exceptions.size(),
1964                                                 Exceptions.data(),
1965                                                 Proto->getExtInfo()));
1966  }
1967
1968  SemaRef.InstantiateAttrs(TemplateArgs, Tmpl, New);
1969
1970  return false;
1971}
1972
1973/// \brief Initializes common fields of an instantiated method
1974/// declaration (New) from the corresponding fields of its template
1975/// (Tmpl).
1976///
1977/// \returns true if there was an error
1978bool
1979TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
1980                                                  CXXMethodDecl *Tmpl) {
1981  if (InitFunctionInstantiation(New, Tmpl))
1982    return true;
1983
1984  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
1985  New->setAccess(Tmpl->getAccess());
1986  if (Tmpl->isVirtualAsWritten())
1987    Record->setMethodAsVirtual(New);
1988
1989  // FIXME: attributes
1990  // FIXME: New needs a pointer to Tmpl
1991  return false;
1992}
1993
1994/// \brief Instantiate the definition of the given function from its
1995/// template.
1996///
1997/// \param PointOfInstantiation the point at which the instantiation was
1998/// required. Note that this is not precisely a "point of instantiation"
1999/// for the function, but it's close.
2000///
2001/// \param Function the already-instantiated declaration of a
2002/// function template specialization or member function of a class template
2003/// specialization.
2004///
2005/// \param Recursive if true, recursively instantiates any functions that
2006/// are required by this instantiation.
2007///
2008/// \param DefinitionRequired if true, then we are performing an explicit
2009/// instantiation where the body of the function is required. Complain if
2010/// there is no such body.
2011void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
2012                                         FunctionDecl *Function,
2013                                         bool Recursive,
2014                                         bool DefinitionRequired) {
2015  if (Function->isInvalidDecl() || Function->hasBody())
2016    return;
2017
2018  // Never instantiate an explicit specialization.
2019  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2020    return;
2021
2022  // Find the function body that we'll be substituting.
2023  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
2024  Stmt *Pattern = 0;
2025  if (PatternDecl)
2026    Pattern = PatternDecl->getBody(PatternDecl);
2027
2028  if (!Pattern) {
2029    if (DefinitionRequired) {
2030      if (Function->getPrimaryTemplate())
2031        Diag(PointOfInstantiation,
2032             diag::err_explicit_instantiation_undefined_func_template)
2033          << Function->getPrimaryTemplate();
2034      else
2035        Diag(PointOfInstantiation,
2036             diag::err_explicit_instantiation_undefined_member)
2037          << 1 << Function->getDeclName() << Function->getDeclContext();
2038
2039      if (PatternDecl)
2040        Diag(PatternDecl->getLocation(),
2041             diag::note_explicit_instantiation_here);
2042      Function->setInvalidDecl();
2043    } else if (Function->getTemplateSpecializationKind()
2044                 == TSK_ExplicitInstantiationDefinition) {
2045      PendingInstantiations.push_back(
2046        std::make_pair(Function, PointOfInstantiation));
2047    }
2048
2049    return;
2050  }
2051
2052  // C++0x [temp.explicit]p9:
2053  //   Except for inline functions, other explicit instantiation declarations
2054  //   have the effect of suppressing the implicit instantiation of the entity
2055  //   to which they refer.
2056  if (Function->getTemplateSpecializationKind()
2057        == TSK_ExplicitInstantiationDeclaration &&
2058      !PatternDecl->isInlined())
2059    return;
2060
2061  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2062  if (Inst)
2063    return;
2064
2065  // If we're performing recursive template instantiation, create our own
2066  // queue of pending implicit instantiations that we will instantiate later,
2067  // while we're still within our own instantiation context.
2068  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2069  if (Recursive)
2070    PendingInstantiations.swap(SavedPendingInstantiations);
2071
2072  EnterExpressionEvaluationContext EvalContext(*this,
2073                                               Action::PotentiallyEvaluated);
2074  ActOnStartOfFunctionDef(0, Function);
2075
2076  // Introduce a new scope where local variable instantiations will be
2077  // recorded, unless we're actually a member function within a local
2078  // class, in which case we need to merge our results with the parent
2079  // scope (of the enclosing function).
2080  bool MergeWithParentScope = false;
2081  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2082    MergeWithParentScope = Rec->isLocalClass();
2083
2084  LocalInstantiationScope Scope(*this, MergeWithParentScope);
2085
2086  // Introduce the instantiated function parameters into the local
2087  // instantiation scope, and set the parameter names to those used
2088  // in the template.
2089  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
2090    const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
2091    ParmVarDecl *FunctionParam = Function->getParamDecl(I);
2092    FunctionParam->setDeclName(PatternParam->getDeclName());
2093    Scope.InstantiatedLocal(PatternParam, FunctionParam);
2094  }
2095
2096  // Enter the scope of this instantiation. We don't use
2097  // PushDeclContext because we don't have a scope.
2098  DeclContext *PreviousContext = CurContext;
2099  CurContext = Function;
2100
2101  MultiLevelTemplateArgumentList TemplateArgs =
2102    getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
2103
2104  // If this is a constructor, instantiate the member initializers.
2105  if (const CXXConstructorDecl *Ctor =
2106        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2107    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2108                               TemplateArgs);
2109  }
2110
2111  // Instantiate the function body.
2112  StmtResult Body = SubstStmt(Pattern, TemplateArgs);
2113
2114  if (Body.isInvalid())
2115    Function->setInvalidDecl();
2116
2117  ActOnFinishFunctionBody(Function, Body.get(),
2118                          /*IsInstantiation=*/true);
2119
2120  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2121
2122  CurContext = PreviousContext;
2123
2124  DeclGroupRef DG(Function);
2125  Consumer.HandleTopLevelDecl(DG);
2126
2127  // This class may have local implicit instantiations that need to be
2128  // instantiation within this scope.
2129  PerformPendingInstantiations(/*LocalOnly=*/true);
2130  Scope.Exit();
2131
2132  if (Recursive) {
2133    // Instantiate any pending implicit instantiations found during the
2134    // instantiation of this template.
2135    PerformPendingInstantiations();
2136
2137    // Restore the set of pending implicit instantiations.
2138    PendingInstantiations.swap(SavedPendingInstantiations);
2139  }
2140}
2141
2142/// \brief Instantiate the definition of the given variable from its
2143/// template.
2144///
2145/// \param PointOfInstantiation the point at which the instantiation was
2146/// required. Note that this is not precisely a "point of instantiation"
2147/// for the function, but it's close.
2148///
2149/// \param Var the already-instantiated declaration of a static member
2150/// variable of a class template specialization.
2151///
2152/// \param Recursive if true, recursively instantiates any functions that
2153/// are required by this instantiation.
2154///
2155/// \param DefinitionRequired if true, then we are performing an explicit
2156/// instantiation where an out-of-line definition of the member variable
2157/// is required. Complain if there is no such definition.
2158void Sema::InstantiateStaticDataMemberDefinition(
2159                                          SourceLocation PointOfInstantiation,
2160                                                 VarDecl *Var,
2161                                                 bool Recursive,
2162                                                 bool DefinitionRequired) {
2163  if (Var->isInvalidDecl())
2164    return;
2165
2166  // Find the out-of-line definition of this static data member.
2167  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2168  assert(Def && "This data member was not instantiated from a template?");
2169  assert(Def->isStaticDataMember() && "Not a static data member?");
2170  Def = Def->getOutOfLineDefinition();
2171
2172  if (!Def) {
2173    // We did not find an out-of-line definition of this static data member,
2174    // so we won't perform any instantiation. Rather, we rely on the user to
2175    // instantiate this definition (or provide a specialization for it) in
2176    // another translation unit.
2177    if (DefinitionRequired) {
2178      Def = Var->getInstantiatedFromStaticDataMember();
2179      Diag(PointOfInstantiation,
2180           diag::err_explicit_instantiation_undefined_member)
2181        << 2 << Var->getDeclName() << Var->getDeclContext();
2182      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2183    } else if (Var->getTemplateSpecializationKind()
2184                 == TSK_ExplicitInstantiationDefinition) {
2185      PendingInstantiations.push_back(
2186        std::make_pair(Var, PointOfInstantiation));
2187    }
2188
2189    return;
2190  }
2191
2192  // Never instantiate an explicit specialization.
2193  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2194    return;
2195
2196  // C++0x [temp.explicit]p9:
2197  //   Except for inline functions, other explicit instantiation declarations
2198  //   have the effect of suppressing the implicit instantiation of the entity
2199  //   to which they refer.
2200  if (Var->getTemplateSpecializationKind()
2201        == TSK_ExplicitInstantiationDeclaration)
2202    return;
2203
2204  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2205  if (Inst)
2206    return;
2207
2208  // If we're performing recursive template instantiation, create our own
2209  // queue of pending implicit instantiations that we will instantiate later,
2210  // while we're still within our own instantiation context.
2211  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2212  if (Recursive)
2213    PendingInstantiations.swap(SavedPendingInstantiations);
2214
2215  // Enter the scope of this instantiation. We don't use
2216  // PushDeclContext because we don't have a scope.
2217  DeclContext *PreviousContext = CurContext;
2218  CurContext = Var->getDeclContext();
2219
2220  VarDecl *OldVar = Var;
2221  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2222                                          getTemplateInstantiationArgs(Var)));
2223  CurContext = PreviousContext;
2224
2225  if (Var) {
2226    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2227    assert(MSInfo && "Missing member specialization information?");
2228    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2229                                       MSInfo->getPointOfInstantiation());
2230    DeclGroupRef DG(Var);
2231    Consumer.HandleTopLevelDecl(DG);
2232  }
2233
2234  if (Recursive) {
2235    // Instantiate any pending implicit instantiations found during the
2236    // instantiation of this template.
2237    PerformPendingInstantiations();
2238
2239    // Restore the set of pending implicit instantiations.
2240    PendingInstantiations.swap(SavedPendingInstantiations);
2241  }
2242}
2243
2244void
2245Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2246                                 const CXXConstructorDecl *Tmpl,
2247                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2248
2249  llvm::SmallVector<MemInitTy*, 4> NewInits;
2250  bool AnyErrors = false;
2251
2252  // Instantiate all the initializers.
2253  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2254                                            InitsEnd = Tmpl->init_end();
2255       Inits != InitsEnd; ++Inits) {
2256    CXXBaseOrMemberInitializer *Init = *Inits;
2257
2258    SourceLocation LParenLoc, RParenLoc;
2259    ASTOwningVector<Expr*> NewArgs(*this);
2260    llvm::SmallVector<SourceLocation, 4> CommaLocs;
2261
2262    // Instantiate the initializer.
2263    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2264                               LParenLoc, CommaLocs, NewArgs, RParenLoc)) {
2265      AnyErrors = true;
2266      continue;
2267    }
2268
2269    MemInitResult NewInit;
2270    if (Init->isBaseInitializer()) {
2271      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2272                                            TemplateArgs,
2273                                            Init->getSourceLocation(),
2274                                            New->getDeclName());
2275      if (!BaseTInfo) {
2276        AnyErrors = true;
2277        New->setInvalidDecl();
2278        continue;
2279      }
2280
2281      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2282                                     (Expr **)NewArgs.data(),
2283                                     NewArgs.size(),
2284                                     Init->getLParenLoc(),
2285                                     Init->getRParenLoc(),
2286                                     New->getParent());
2287    } else if (Init->isMemberInitializer()) {
2288      FieldDecl *Member;
2289
2290      // Is this an anonymous union?
2291      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2292        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2293                                                      UnionInit, TemplateArgs));
2294      else
2295        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2296                                                      Init->getMember(),
2297                                                      TemplateArgs));
2298
2299      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2300                                       NewArgs.size(),
2301                                       Init->getSourceLocation(),
2302                                       Init->getLParenLoc(),
2303                                       Init->getRParenLoc());
2304    }
2305
2306    if (NewInit.isInvalid()) {
2307      AnyErrors = true;
2308      New->setInvalidDecl();
2309    } else {
2310      // FIXME: It would be nice if ASTOwningVector had a release function.
2311      NewArgs.take();
2312
2313      NewInits.push_back((MemInitTy *)NewInit.get());
2314    }
2315  }
2316
2317  // Assign all the initializers to the new constructor.
2318  ActOnMemInitializers(New,
2319                       /*FIXME: ColonLoc */
2320                       SourceLocation(),
2321                       NewInits.data(), NewInits.size(),
2322                       AnyErrors);
2323}
2324
2325// TODO: this could be templated if the various decl types used the
2326// same method name.
2327static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2328                              ClassTemplateDecl *Instance) {
2329  Pattern = Pattern->getCanonicalDecl();
2330
2331  do {
2332    Instance = Instance->getCanonicalDecl();
2333    if (Pattern == Instance) return true;
2334    Instance = Instance->getInstantiatedFromMemberTemplate();
2335  } while (Instance);
2336
2337  return false;
2338}
2339
2340static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2341                              FunctionTemplateDecl *Instance) {
2342  Pattern = Pattern->getCanonicalDecl();
2343
2344  do {
2345    Instance = Instance->getCanonicalDecl();
2346    if (Pattern == Instance) return true;
2347    Instance = Instance->getInstantiatedFromMemberTemplate();
2348  } while (Instance);
2349
2350  return false;
2351}
2352
2353static bool
2354isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2355                  ClassTemplatePartialSpecializationDecl *Instance) {
2356  Pattern
2357    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2358  do {
2359    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2360                                                Instance->getCanonicalDecl());
2361    if (Pattern == Instance)
2362      return true;
2363    Instance = Instance->getInstantiatedFromMember();
2364  } while (Instance);
2365
2366  return false;
2367}
2368
2369static bool isInstantiationOf(CXXRecordDecl *Pattern,
2370                              CXXRecordDecl *Instance) {
2371  Pattern = Pattern->getCanonicalDecl();
2372
2373  do {
2374    Instance = Instance->getCanonicalDecl();
2375    if (Pattern == Instance) return true;
2376    Instance = Instance->getInstantiatedFromMemberClass();
2377  } while (Instance);
2378
2379  return false;
2380}
2381
2382static bool isInstantiationOf(FunctionDecl *Pattern,
2383                              FunctionDecl *Instance) {
2384  Pattern = Pattern->getCanonicalDecl();
2385
2386  do {
2387    Instance = Instance->getCanonicalDecl();
2388    if (Pattern == Instance) return true;
2389    Instance = Instance->getInstantiatedFromMemberFunction();
2390  } while (Instance);
2391
2392  return false;
2393}
2394
2395static bool isInstantiationOf(EnumDecl *Pattern,
2396                              EnumDecl *Instance) {
2397  Pattern = Pattern->getCanonicalDecl();
2398
2399  do {
2400    Instance = Instance->getCanonicalDecl();
2401    if (Pattern == Instance) return true;
2402    Instance = Instance->getInstantiatedFromMemberEnum();
2403  } while (Instance);
2404
2405  return false;
2406}
2407
2408static bool isInstantiationOf(UsingShadowDecl *Pattern,
2409                              UsingShadowDecl *Instance,
2410                              ASTContext &C) {
2411  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2412}
2413
2414static bool isInstantiationOf(UsingDecl *Pattern,
2415                              UsingDecl *Instance,
2416                              ASTContext &C) {
2417  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2418}
2419
2420static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2421                              UsingDecl *Instance,
2422                              ASTContext &C) {
2423  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2424}
2425
2426static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2427                              UsingDecl *Instance,
2428                              ASTContext &C) {
2429  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2430}
2431
2432static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2433                                              VarDecl *Instance) {
2434  assert(Instance->isStaticDataMember());
2435
2436  Pattern = Pattern->getCanonicalDecl();
2437
2438  do {
2439    Instance = Instance->getCanonicalDecl();
2440    if (Pattern == Instance) return true;
2441    Instance = Instance->getInstantiatedFromStaticDataMember();
2442  } while (Instance);
2443
2444  return false;
2445}
2446
2447// Other is the prospective instantiation
2448// D is the prospective pattern
2449static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2450  if (D->getKind() != Other->getKind()) {
2451    if (UnresolvedUsingTypenameDecl *UUD
2452          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2453      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2454        return isInstantiationOf(UUD, UD, Ctx);
2455      }
2456    }
2457
2458    if (UnresolvedUsingValueDecl *UUD
2459          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2460      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2461        return isInstantiationOf(UUD, UD, Ctx);
2462      }
2463    }
2464
2465    return false;
2466  }
2467
2468  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2469    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2470
2471  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2472    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2473
2474  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2475    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2476
2477  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2478    if (Var->isStaticDataMember())
2479      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2480
2481  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2482    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2483
2484  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2485    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2486
2487  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2488        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2489    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2490                             PartialSpec);
2491
2492  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2493    if (!Field->getDeclName()) {
2494      // This is an unnamed field.
2495      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2496        cast<FieldDecl>(D);
2497    }
2498  }
2499
2500  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2501    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2502
2503  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2504    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2505
2506  return D->getDeclName() && isa<NamedDecl>(Other) &&
2507    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2508}
2509
2510template<typename ForwardIterator>
2511static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2512                                      NamedDecl *D,
2513                                      ForwardIterator first,
2514                                      ForwardIterator last) {
2515  for (; first != last; ++first)
2516    if (isInstantiationOf(Ctx, D, *first))
2517      return cast<NamedDecl>(*first);
2518
2519  return 0;
2520}
2521
2522/// \brief Finds the instantiation of the given declaration context
2523/// within the current instantiation.
2524///
2525/// \returns NULL if there was an error
2526DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2527                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2528  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2529    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2530    return cast_or_null<DeclContext>(ID);
2531  } else return DC;
2532}
2533
2534/// \brief Find the instantiation of the given declaration within the
2535/// current instantiation.
2536///
2537/// This routine is intended to be used when \p D is a declaration
2538/// referenced from within a template, that needs to mapped into the
2539/// corresponding declaration within an instantiation. For example,
2540/// given:
2541///
2542/// \code
2543/// template<typename T>
2544/// struct X {
2545///   enum Kind {
2546///     KnownValue = sizeof(T)
2547///   };
2548///
2549///   bool getKind() const { return KnownValue; }
2550/// };
2551///
2552/// template struct X<int>;
2553/// \endcode
2554///
2555/// In the instantiation of X<int>::getKind(), we need to map the
2556/// EnumConstantDecl for KnownValue (which refers to
2557/// X<T>::<Kind>::KnownValue) to its instantiation
2558/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2559/// this mapping from within the instantiation of X<int>.
2560NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2561                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2562  DeclContext *ParentDC = D->getDeclContext();
2563  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2564      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2565      (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext())) {
2566    // D is a local of some kind. Look into the map of local
2567    // declarations to their instantiations.
2568    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2569  }
2570
2571  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2572    if (!Record->isDependentContext())
2573      return D;
2574
2575    // If the RecordDecl is actually the injected-class-name or a
2576    // "templated" declaration for a class template, class template
2577    // partial specialization, or a member class of a class template,
2578    // substitute into the injected-class-name of the class template
2579    // or partial specialization to find the new DeclContext.
2580    QualType T;
2581    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2582
2583    if (ClassTemplate) {
2584      T = ClassTemplate->getInjectedClassNameSpecialization();
2585    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2586                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2587      ClassTemplate = PartialSpec->getSpecializedTemplate();
2588
2589      // If we call SubstType with an InjectedClassNameType here we
2590      // can end up in an infinite loop.
2591      T = Context.getTypeDeclType(Record);
2592      assert(isa<InjectedClassNameType>(T) &&
2593             "type of partial specialization is not an InjectedClassNameType");
2594      T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
2595    }
2596
2597    if (!T.isNull()) {
2598      // Substitute into the injected-class-name to get the type
2599      // corresponding to the instantiation we want, which may also be
2600      // the current instantiation (if we're in a template
2601      // definition). This substitution should never fail, since we
2602      // know we can instantiate the injected-class-name or we
2603      // wouldn't have gotten to the injected-class-name!
2604
2605      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2606      // extra instantiation in the common case?
2607      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2608      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2609
2610      if (!T->isDependentType()) {
2611        assert(T->isRecordType() && "Instantiation must produce a record type");
2612        return T->getAs<RecordType>()->getDecl();
2613      }
2614
2615      // We are performing "partial" template instantiation to create
2616      // the member declarations for the members of a class template
2617      // specialization. Therefore, D is actually referring to something
2618      // in the current instantiation. Look through the current
2619      // context, which contains actual instantiations, to find the
2620      // instantiation of the "current instantiation" that D refers
2621      // to.
2622      bool SawNonDependentContext = false;
2623      for (DeclContext *DC = CurContext; !DC->isFileContext();
2624           DC = DC->getParent()) {
2625        if (ClassTemplateSpecializationDecl *Spec
2626                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2627          if (isInstantiationOf(ClassTemplate,
2628                                Spec->getSpecializedTemplate()))
2629            return Spec;
2630
2631        if (!DC->isDependentContext())
2632          SawNonDependentContext = true;
2633      }
2634
2635      // We're performing "instantiation" of a member of the current
2636      // instantiation while we are type-checking the
2637      // definition. Compute the declaration context and return that.
2638      assert(!SawNonDependentContext &&
2639             "No dependent context while instantiating record");
2640      DeclContext *DC = computeDeclContext(T);
2641      assert(DC &&
2642             "Unable to find declaration for the current instantiation");
2643      return cast<CXXRecordDecl>(DC);
2644    }
2645
2646    // Fall through to deal with other dependent record types (e.g.,
2647    // anonymous unions in class templates).
2648  }
2649
2650  if (!ParentDC->isDependentContext())
2651    return D;
2652
2653  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2654  if (!ParentDC)
2655    return 0;
2656
2657  if (ParentDC != D->getDeclContext()) {
2658    // We performed some kind of instantiation in the parent context,
2659    // so now we need to look into the instantiated parent context to
2660    // find the instantiation of the declaration D.
2661
2662    // If our context used to be dependent, we may need to instantiate
2663    // it before performing lookup into that context.
2664    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2665      if (!Spec->isDependentContext()) {
2666        QualType T = Context.getTypeDeclType(Spec);
2667        const RecordType *Tag = T->getAs<RecordType>();
2668        assert(Tag && "type of non-dependent record is not a RecordType");
2669        if (!Tag->isBeingDefined() &&
2670            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2671          return 0;
2672      }
2673    }
2674
2675    NamedDecl *Result = 0;
2676    if (D->getDeclName()) {
2677      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2678      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2679    } else {
2680      // Since we don't have a name for the entity we're looking for,
2681      // our only option is to walk through all of the declarations to
2682      // find that name. This will occur in a few cases:
2683      //
2684      //   - anonymous struct/union within a template
2685      //   - unnamed class/struct/union/enum within a template
2686      //
2687      // FIXME: Find a better way to find these instantiations!
2688      Result = findInstantiationOf(Context, D,
2689                                   ParentDC->decls_begin(),
2690                                   ParentDC->decls_end());
2691    }
2692
2693    // UsingShadowDecls can instantiate to nothing because of using hiding.
2694    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2695            cast<Decl>(ParentDC)->isInvalidDecl())
2696           && "Unable to find instantiation of declaration!");
2697
2698    D = Result;
2699  }
2700
2701  return D;
2702}
2703
2704/// \brief Performs template instantiation for all implicit template
2705/// instantiations we have seen until this point.
2706void Sema::PerformPendingInstantiations(bool LocalOnly) {
2707  while (!PendingLocalImplicitInstantiations.empty() ||
2708         (!LocalOnly && !PendingInstantiations.empty())) {
2709    PendingImplicitInstantiation Inst;
2710
2711    if (PendingLocalImplicitInstantiations.empty()) {
2712      Inst = PendingInstantiations.front();
2713      PendingInstantiations.pop_front();
2714    } else {
2715      Inst = PendingLocalImplicitInstantiations.front();
2716      PendingLocalImplicitInstantiations.pop_front();
2717    }
2718
2719    // Instantiate function definitions
2720    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2721      PrettyStackTraceActionsDecl CrashInfo(Function,
2722                                            Function->getLocation(), *this,
2723                                            Context.getSourceManager(),
2724                                           "instantiating function definition");
2725      bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
2726                                TSK_ExplicitInstantiationDefinition;
2727      InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true,
2728                                    DefinitionRequired);
2729      continue;
2730    }
2731
2732    // Instantiate static data member definitions.
2733    VarDecl *Var = cast<VarDecl>(Inst.first);
2734    assert(Var->isStaticDataMember() && "Not a static data member?");
2735
2736    // Don't try to instantiate declarations if the most recent redeclaration
2737    // is invalid.
2738    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2739      continue;
2740
2741    // Check if the most recent declaration has changed the specialization kind
2742    // and removed the need for implicit instantiation.
2743    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2744    case TSK_Undeclared:
2745      assert(false && "Cannot instantitiate an undeclared specialization.");
2746    case TSK_ExplicitInstantiationDeclaration:
2747    case TSK_ExplicitSpecialization:
2748      continue;  // No longer need to instantiate this type.
2749    case TSK_ExplicitInstantiationDefinition:
2750      // We only need an instantiation if the pending instantiation *is* the
2751      // explicit instantiation.
2752      if (Var != Var->getMostRecentDeclaration()) continue;
2753    case TSK_ImplicitInstantiation:
2754      break;
2755    }
2756
2757    PrettyStackTraceActionsDecl CrashInfo(Var, Var->getLocation(), *this,
2758                                          Context.getSourceManager(),
2759                                          "instantiating static data member "
2760                                          "definition");
2761
2762    bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
2763                              TSK_ExplicitInstantiationDefinition;
2764    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true,
2765                                          DefinitionRequired);
2766  }
2767}
2768
2769void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2770                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2771  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2772         E = Pattern->ddiag_end(); I != E; ++I) {
2773    DependentDiagnostic *DD = *I;
2774
2775    switch (DD->getKind()) {
2776    case DependentDiagnostic::Access:
2777      HandleDependentAccessCheck(*DD, TemplateArgs);
2778      break;
2779    }
2780  }
2781}
2782