SemaTemplateInstantiateDecl.cpp revision 7a126a474fdde06382b315b4e3d8ef0a21d4dc31 
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/SemaInternal.h"
13#include "clang/Sema/Lookup.h"
14#include "clang/Sema/PrettyDeclStackTrace.h"
15#include "clang/Sema/Template.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/DeclTemplate.h"
19#include "clang/AST/DeclVisitor.h"
20#include "clang/AST/DependentDiagnostic.h"
21#include "clang/AST/Expr.h"
22#include "clang/AST/ExprCXX.h"
23#include "clang/AST/TypeLoc.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                                                     Sema::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, Sema::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->getRedeclContext()->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, Sema::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                                                   Sema::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()->getRedeclContext()->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    bool queuedInstantiation = false;
1171
1172    if (!SemaRef.getLangOptions().CPlusPlus0x &&
1173        D->isThisDeclarationADefinition()) {
1174      // Check for a function body.
1175      const FunctionDecl *Definition = 0;
1176      if (Function->hasBody(Definition) &&
1177          Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1178        SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1179          << Function->getDeclName();
1180        SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1181        Function->setInvalidDecl();
1182      }
1183      // Check for redefinitions due to other instantiations of this or
1184      // a similar friend function.
1185      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1186                                           REnd = Function->redecls_end();
1187                R != REnd; ++R) {
1188        if (*R == Function)
1189          continue;
1190        switch (R->getFriendObjectKind()) {
1191        case Decl::FOK_None:
1192          if (!queuedInstantiation && R->isUsed(false)) {
1193            if (MemberSpecializationInfo *MSInfo
1194                = Function->getMemberSpecializationInfo()) {
1195              if (MSInfo->getPointOfInstantiation().isInvalid()) {
1196                SourceLocation Loc = R->getLocation(); // FIXME
1197                MSInfo->setPointOfInstantiation(Loc);
1198                SemaRef.PendingLocalImplicitInstantiations.push_back(
1199                                                 std::make_pair(Function, Loc));
1200                queuedInstantiation = true;
1201              }
1202            }
1203          }
1204          break;
1205        default:
1206          if (const FunctionDecl *RPattern
1207              = R->getTemplateInstantiationPattern())
1208            if (RPattern->hasBody(RPattern)) {
1209              SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1210                << Function->getDeclName();
1211              SemaRef.Diag(R->getLocation(), diag::note_previous_definition);
1212              Function->setInvalidDecl();
1213              break;
1214            }
1215        }
1216      }
1217    }
1218  }
1219
1220  if (Function->isOverloadedOperator() && !DC->isRecord() &&
1221      PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1222    PrincipalDecl->setNonMemberOperator();
1223
1224  return Function;
1225}
1226
1227Decl *
1228TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1229                                      TemplateParameterList *TemplateParams) {
1230  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1231  void *InsertPos = 0;
1232  if (FunctionTemplate && !TemplateParams) {
1233    // We are creating a function template specialization from a function
1234    // template. Check whether there is already a function template
1235    // specialization for this particular set of template arguments.
1236    std::pair<const TemplateArgument *, unsigned> Innermost
1237      = TemplateArgs.getInnermost();
1238
1239    FunctionDecl *SpecFunc
1240      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
1241                                             InsertPos);
1242
1243    // If we already have a function template specialization, return it.
1244    if (SpecFunc)
1245      return SpecFunc;
1246  }
1247
1248  bool isFriend;
1249  if (FunctionTemplate)
1250    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1251  else
1252    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1253
1254  bool MergeWithParentScope = (TemplateParams != 0) ||
1255    !(isa<Decl>(Owner) &&
1256      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1257  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1258
1259  llvm::SmallVector<ParmVarDecl *, 4> Params;
1260  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1261  TInfo = SubstFunctionType(D, Params);
1262  if (!TInfo)
1263    return 0;
1264  QualType T = TInfo->getType();
1265
1266  // \brief If the type of this function is not *directly* a function
1267  // type, then we're instantiating the a function that was declared
1268  // via a typedef, e.g.,
1269  //
1270  //   typedef int functype(int, int);
1271  //   functype func;
1272  //
1273  // In this case, we'll just go instantiate the ParmVarDecls that we
1274  // synthesized in the method declaration.
1275  if (!isa<FunctionProtoType>(T)) {
1276    assert(!Params.size() && "Instantiating type could not yield parameters");
1277    for (unsigned I = 0, N = D->getNumParams(); I != N; ++I) {
1278      ParmVarDecl *P = SemaRef.SubstParmVarDecl(D->getParamDecl(I),
1279                                                TemplateArgs);
1280      if (!P)
1281        return 0;
1282
1283      Params.push_back(P);
1284    }
1285  }
1286
1287  NestedNameSpecifier *Qualifier = D->getQualifier();
1288  if (Qualifier) {
1289    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1290                                                 D->getQualifierRange(),
1291                                                 TemplateArgs);
1292    if (!Qualifier) return 0;
1293  }
1294
1295  DeclContext *DC = Owner;
1296  if (isFriend) {
1297    if (Qualifier) {
1298      CXXScopeSpec SS;
1299      SS.setScopeRep(Qualifier);
1300      SS.setRange(D->getQualifierRange());
1301      DC = SemaRef.computeDeclContext(SS);
1302    } else {
1303      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1304                                           D->getDeclContext(),
1305                                           TemplateArgs);
1306    }
1307    if (!DC) return 0;
1308  }
1309
1310  // Build the instantiated method declaration.
1311  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1312  CXXMethodDecl *Method = 0;
1313
1314  DeclarationNameInfo NameInfo
1315    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1316  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1317    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1318                                        NameInfo, T, TInfo,
1319                                        Constructor->isExplicit(),
1320                                        Constructor->isInlineSpecified(),
1321                                        false);
1322  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1323    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1324                                       NameInfo, T,
1325                                       Destructor->isInlineSpecified(),
1326                                       false);
1327  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1328    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1329                                       NameInfo, T, TInfo,
1330                                       Conversion->isInlineSpecified(),
1331                                       Conversion->isExplicit());
1332  } else {
1333    Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1334                                   NameInfo, T, TInfo,
1335                                   D->isStatic(),
1336                                   D->getStorageClassAsWritten(),
1337                                   D->isInlineSpecified());
1338  }
1339
1340  if (Qualifier)
1341    Method->setQualifierInfo(Qualifier, D->getQualifierRange());
1342
1343  if (TemplateParams) {
1344    // Our resulting instantiation is actually a function template, since we
1345    // are substituting only the outer template parameters. For example, given
1346    //
1347    //   template<typename T>
1348    //   struct X {
1349    //     template<typename U> void f(T, U);
1350    //   };
1351    //
1352    //   X<int> x;
1353    //
1354    // We are instantiating the member template "f" within X<int>, which means
1355    // substituting int for T, but leaving "f" as a member function template.
1356    // Build the function template itself.
1357    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1358                                                    Method->getLocation(),
1359                                                    Method->getDeclName(),
1360                                                    TemplateParams, Method);
1361    if (isFriend) {
1362      FunctionTemplate->setLexicalDeclContext(Owner);
1363      FunctionTemplate->setObjectOfFriendDecl(true);
1364    } else if (D->isOutOfLine())
1365      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1366    Method->setDescribedFunctionTemplate(FunctionTemplate);
1367  } else if (FunctionTemplate) {
1368    // Record this function template specialization.
1369    std::pair<const TemplateArgument *, unsigned> Innermost
1370      = TemplateArgs.getInnermost();
1371    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1372                    new (SemaRef.Context) TemplateArgumentList(SemaRef.Context,
1373                                                              Innermost.first,
1374                                                              Innermost.second),
1375                                              InsertPos);
1376  } else if (!isFriend) {
1377    // Record that this is an instantiation of a member function.
1378    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1379  }
1380
1381  // If we are instantiating a member function defined
1382  // out-of-line, the instantiation will have the same lexical
1383  // context (which will be a namespace scope) as the template.
1384  if (isFriend) {
1385    Method->setLexicalDeclContext(Owner);
1386    Method->setObjectOfFriendDecl(true);
1387  } else if (D->isOutOfLine())
1388    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1389
1390  // Attach the parameters
1391  for (unsigned P = 0; P < Params.size(); ++P)
1392    Params[P]->setOwningFunction(Method);
1393  Method->setParams(Params.data(), Params.size());
1394
1395  if (InitMethodInstantiation(Method, D))
1396    Method->setInvalidDecl();
1397
1398  LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
1399                        Sema::ForRedeclaration);
1400
1401  if (!FunctionTemplate || TemplateParams || isFriend) {
1402    SemaRef.LookupQualifiedName(Previous, Record);
1403
1404    // In C++, the previous declaration we find might be a tag type
1405    // (class or enum). In this case, the new declaration will hide the
1406    // tag type. Note that this does does not apply if we're declaring a
1407    // typedef (C++ [dcl.typedef]p4).
1408    if (Previous.isSingleTagDecl())
1409      Previous.clear();
1410  }
1411
1412  bool Redeclaration = false;
1413  bool OverloadableAttrRequired = false;
1414  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1415                                   /*FIXME:*/OverloadableAttrRequired);
1416
1417  if (D->isPure())
1418    SemaRef.CheckPureMethod(Method, SourceRange());
1419
1420  Method->setAccess(D->getAccess());
1421
1422  if (FunctionTemplate) {
1423    // If there's a function template, let our caller handle it.
1424  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1425    // Don't hide a (potentially) valid declaration with an invalid one.
1426  } else {
1427    NamedDecl *DeclToAdd = (TemplateParams
1428                            ? cast<NamedDecl>(FunctionTemplate)
1429                            : Method);
1430    if (isFriend)
1431      Record->makeDeclVisibleInContext(DeclToAdd);
1432    else
1433      Owner->addDecl(DeclToAdd);
1434  }
1435
1436  return Method;
1437}
1438
1439Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1440  return VisitCXXMethodDecl(D);
1441}
1442
1443Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1444  return VisitCXXMethodDecl(D);
1445}
1446
1447Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1448  return VisitCXXMethodDecl(D);
1449}
1450
1451ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1452  return SemaRef.SubstParmVarDecl(D, TemplateArgs);
1453}
1454
1455Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1456                                                    TemplateTypeParmDecl *D) {
1457  // TODO: don't always clone when decls are refcounted.
1458  const Type* T = D->getTypeForDecl();
1459  assert(T->isTemplateTypeParmType());
1460  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1461
1462  TemplateTypeParmDecl *Inst =
1463    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1464                                 TTPT->getDepth() - TemplateArgs.getNumLevels(),
1465                                 TTPT->getIndex(),TTPT->getName(),
1466                                 D->wasDeclaredWithTypename(),
1467                                 D->isParameterPack());
1468
1469  if (D->hasDefaultArgument())
1470    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1471
1472  // Introduce this template parameter's instantiation into the instantiation
1473  // scope.
1474  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1475
1476  return Inst;
1477}
1478
1479Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1480                                                 NonTypeTemplateParmDecl *D) {
1481  // Substitute into the type of the non-type template parameter.
1482  QualType T;
1483  TypeSourceInfo *DI = D->getTypeSourceInfo();
1484  if (DI) {
1485    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1486                           D->getDeclName());
1487    if (DI) T = DI->getType();
1488  } else {
1489    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1490                          D->getDeclName());
1491    DI = 0;
1492  }
1493  if (T.isNull())
1494    return 0;
1495
1496  // Check that this type is acceptable for a non-type template parameter.
1497  bool Invalid = false;
1498  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1499  if (T.isNull()) {
1500    T = SemaRef.Context.IntTy;
1501    Invalid = true;
1502  }
1503
1504  NonTypeTemplateParmDecl *Param
1505    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1506                                    D->getDepth() - TemplateArgs.getNumLevels(),
1507                                      D->getPosition(), D->getIdentifier(), T,
1508                                      DI);
1509  if (Invalid)
1510    Param->setInvalidDecl();
1511
1512  Param->setDefaultArgument(D->getDefaultArgument(), false);
1513
1514  // Introduce this template parameter's instantiation into the instantiation
1515  // scope.
1516  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1517  return Param;
1518}
1519
1520Decl *
1521TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1522                                                  TemplateTemplateParmDecl *D) {
1523  // Instantiate the template parameter list of the template template parameter.
1524  TemplateParameterList *TempParams = D->getTemplateParameters();
1525  TemplateParameterList *InstParams;
1526  {
1527    // Perform the actual substitution of template parameters within a new,
1528    // local instantiation scope.
1529    LocalInstantiationScope Scope(SemaRef);
1530    InstParams = SubstTemplateParams(TempParams);
1531    if (!InstParams)
1532      return NULL;
1533  }
1534
1535  // Build the template template parameter.
1536  TemplateTemplateParmDecl *Param
1537    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1538                                   D->getDepth() - TemplateArgs.getNumLevels(),
1539                                       D->getPosition(), D->getIdentifier(),
1540                                       InstParams);
1541  Param->setDefaultArgument(D->getDefaultArgument(), false);
1542
1543  // Introduce this template parameter's instantiation into the instantiation
1544  // scope.
1545  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1546
1547  return Param;
1548}
1549
1550Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1551  // Using directives are never dependent, so they require no explicit
1552
1553  UsingDirectiveDecl *Inst
1554    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1555                                 D->getNamespaceKeyLocation(),
1556                                 D->getQualifierRange(), D->getQualifier(),
1557                                 D->getIdentLocation(),
1558                                 D->getNominatedNamespace(),
1559                                 D->getCommonAncestor());
1560  Owner->addDecl(Inst);
1561  return Inst;
1562}
1563
1564Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1565  // The nested name specifier is non-dependent, so no transformation
1566  // is required. The same holds for the name info.
1567  DeclarationNameInfo NameInfo = D->getNameInfo();
1568
1569  // We only need to do redeclaration lookups if we're in a class
1570  // scope (in fact, it's not really even possible in non-class
1571  // scopes).
1572  bool CheckRedeclaration = Owner->isRecord();
1573
1574  LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
1575                    Sema::ForRedeclaration);
1576
1577  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1578                                       D->getNestedNameRange(),
1579                                       D->getUsingLocation(),
1580                                       D->getTargetNestedNameDecl(),
1581                                       NameInfo,
1582                                       D->isTypeName());
1583
1584  CXXScopeSpec SS;
1585  SS.setScopeRep(D->getTargetNestedNameDecl());
1586  SS.setRange(D->getNestedNameRange());
1587
1588  if (CheckRedeclaration) {
1589    Prev.setHideTags(false);
1590    SemaRef.LookupQualifiedName(Prev, Owner);
1591
1592    // Check for invalid redeclarations.
1593    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1594                                            D->isTypeName(), SS,
1595                                            D->getLocation(), Prev))
1596      NewUD->setInvalidDecl();
1597
1598  }
1599
1600  if (!NewUD->isInvalidDecl() &&
1601      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1602                                      D->getLocation()))
1603    NewUD->setInvalidDecl();
1604
1605  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1606  NewUD->setAccess(D->getAccess());
1607  Owner->addDecl(NewUD);
1608
1609  // Don't process the shadow decls for an invalid decl.
1610  if (NewUD->isInvalidDecl())
1611    return NewUD;
1612
1613  bool isFunctionScope = Owner->isFunctionOrMethod();
1614
1615  // Process the shadow decls.
1616  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1617         I != E; ++I) {
1618    UsingShadowDecl *Shadow = *I;
1619    NamedDecl *InstTarget =
1620      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1621                                                   Shadow->getTargetDecl(),
1622                                                   TemplateArgs));
1623
1624    if (CheckRedeclaration &&
1625        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1626      continue;
1627
1628    UsingShadowDecl *InstShadow
1629      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1630    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1631
1632    if (isFunctionScope)
1633      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1634  }
1635
1636  return NewUD;
1637}
1638
1639Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1640  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1641  return 0;
1642}
1643
1644Decl * TemplateDeclInstantiator
1645    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1646  NestedNameSpecifier *NNS =
1647    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1648                                     D->getTargetNestedNameRange(),
1649                                     TemplateArgs);
1650  if (!NNS)
1651    return 0;
1652
1653  CXXScopeSpec SS;
1654  SS.setRange(D->getTargetNestedNameRange());
1655  SS.setScopeRep(NNS);
1656
1657  // Since NameInfo refers to a typename, it cannot be a C++ special name.
1658  // Hence, no tranformation is required for it.
1659  DeclarationNameInfo NameInfo(D->getDeclName(), D->getLocation());
1660  NamedDecl *UD =
1661    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1662                                  D->getUsingLoc(), SS, NameInfo, 0,
1663                                  /*instantiation*/ true,
1664                                  /*typename*/ true, D->getTypenameLoc());
1665  if (UD)
1666    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1667
1668  return UD;
1669}
1670
1671Decl * TemplateDeclInstantiator
1672    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1673  NestedNameSpecifier *NNS =
1674    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1675                                     D->getTargetNestedNameRange(),
1676                                     TemplateArgs);
1677  if (!NNS)
1678    return 0;
1679
1680  CXXScopeSpec SS;
1681  SS.setRange(D->getTargetNestedNameRange());
1682  SS.setScopeRep(NNS);
1683
1684  DeclarationNameInfo NameInfo
1685    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1686
1687  NamedDecl *UD =
1688    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1689                                  D->getUsingLoc(), SS, NameInfo, 0,
1690                                  /*instantiation*/ true,
1691                                  /*typename*/ false, SourceLocation());
1692  if (UD)
1693    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1694
1695  return UD;
1696}
1697
1698Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1699                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1700  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1701  if (D->isInvalidDecl())
1702    return 0;
1703
1704  return Instantiator.Visit(D);
1705}
1706
1707/// \brief Instantiates a nested template parameter list in the current
1708/// instantiation context.
1709///
1710/// \param L The parameter list to instantiate
1711///
1712/// \returns NULL if there was an error
1713TemplateParameterList *
1714TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1715  // Get errors for all the parameters before bailing out.
1716  bool Invalid = false;
1717
1718  unsigned N = L->size();
1719  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1720  ParamVector Params;
1721  Params.reserve(N);
1722  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1723       PI != PE; ++PI) {
1724    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1725    Params.push_back(D);
1726    Invalid = Invalid || !D || D->isInvalidDecl();
1727  }
1728
1729  // Clean up if we had an error.
1730  if (Invalid)
1731    return NULL;
1732
1733  TemplateParameterList *InstL
1734    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1735                                    L->getLAngleLoc(), &Params.front(), N,
1736                                    L->getRAngleLoc());
1737  return InstL;
1738}
1739
1740/// \brief Instantiate the declaration of a class template partial
1741/// specialization.
1742///
1743/// \param ClassTemplate the (instantiated) class template that is partially
1744// specialized by the instantiation of \p PartialSpec.
1745///
1746/// \param PartialSpec the (uninstantiated) class template partial
1747/// specialization that we are instantiating.
1748///
1749/// \returns true if there was an error, false otherwise.
1750bool
1751TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1752                                            ClassTemplateDecl *ClassTemplate,
1753                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1754  // Create a local instantiation scope for this class template partial
1755  // specialization, which will contain the instantiations of the template
1756  // parameters.
1757  LocalInstantiationScope Scope(SemaRef);
1758
1759  // Substitute into the template parameters of the class template partial
1760  // specialization.
1761  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1762  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1763  if (!InstParams)
1764    return true;
1765
1766  // Substitute into the template arguments of the class template partial
1767  // specialization.
1768  const TemplateArgumentLoc *PartialSpecTemplateArgs
1769    = PartialSpec->getTemplateArgsAsWritten();
1770  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1771
1772  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1773  for (unsigned I = 0; I != N; ++I) {
1774    TemplateArgumentLoc Loc;
1775    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1776      return true;
1777    InstTemplateArgs.addArgument(Loc);
1778  }
1779
1780
1781  // Check that the template argument list is well-formed for this
1782  // class template.
1783  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1784                                        InstTemplateArgs.size());
1785  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1786                                        PartialSpec->getLocation(),
1787                                        InstTemplateArgs,
1788                                        false,
1789                                        Converted))
1790    return true;
1791
1792  // Figure out where to insert this class template partial specialization
1793  // in the member template's set of class template partial specializations.
1794  void *InsertPos = 0;
1795  ClassTemplateSpecializationDecl *PrevDecl
1796    = ClassTemplate->findPartialSpecialization(Converted.getFlatArguments(),
1797                                                Converted.flatSize(), InsertPos);
1798
1799  // Build the canonical type that describes the converted template
1800  // arguments of the class template partial specialization.
1801  QualType CanonType
1802    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1803                                                  Converted.getFlatArguments(),
1804                                                    Converted.flatSize());
1805
1806  // Build the fully-sugared type for this class template
1807  // specialization as the user wrote in the specialization
1808  // itself. This means that we'll pretty-print the type retrieved
1809  // from the specialization's declaration the way that the user
1810  // actually wrote the specialization, rather than formatting the
1811  // name based on the "canonical" representation used to store the
1812  // template arguments in the specialization.
1813  TypeSourceInfo *WrittenTy
1814    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1815                                                    TemplateName(ClassTemplate),
1816                                                    PartialSpec->getLocation(),
1817                                                    InstTemplateArgs,
1818                                                    CanonType);
1819
1820  if (PrevDecl) {
1821    // We've already seen a partial specialization with the same template
1822    // parameters and template arguments. This can happen, for example, when
1823    // substituting the outer template arguments ends up causing two
1824    // class template partial specializations of a member class template
1825    // to have identical forms, e.g.,
1826    //
1827    //   template<typename T, typename U>
1828    //   struct Outer {
1829    //     template<typename X, typename Y> struct Inner;
1830    //     template<typename Y> struct Inner<T, Y>;
1831    //     template<typename Y> struct Inner<U, Y>;
1832    //   };
1833    //
1834    //   Outer<int, int> outer; // error: the partial specializations of Inner
1835    //                          // have the same signature.
1836    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1837      << WrittenTy;
1838    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1839      << SemaRef.Context.getTypeDeclType(PrevDecl);
1840    return true;
1841  }
1842
1843
1844  // Create the class template partial specialization declaration.
1845  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1846    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
1847                                                     PartialSpec->getTagKind(),
1848                                                     Owner,
1849                                                     PartialSpec->getLocation(),
1850                                                     InstParams,
1851                                                     ClassTemplate,
1852                                                     Converted,
1853                                                     InstTemplateArgs,
1854                                                     CanonType,
1855                                                     0,
1856                             ClassTemplate->getNextPartialSpecSequenceNumber());
1857  // Substitute the nested name specifier, if any.
1858  if (SubstQualifier(PartialSpec, InstPartialSpec))
1859    return 0;
1860
1861  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1862  InstPartialSpec->setTypeAsWritten(WrittenTy);
1863
1864  // Add this partial specialization to the set of class template partial
1865  // specializations.
1866  ClassTemplate->AddPartialSpecialization(InstPartialSpec, InsertPos);
1867  return false;
1868}
1869
1870TypeSourceInfo*
1871TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1872                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1873  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1874  assert(OldTInfo && "substituting function without type source info");
1875  assert(Params.empty() && "parameter vector is non-empty at start");
1876  TypeSourceInfo *NewTInfo
1877    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
1878                                    D->getTypeSpecStartLoc(),
1879                                    D->getDeclName());
1880  if (!NewTInfo)
1881    return 0;
1882
1883  if (NewTInfo != OldTInfo) {
1884    // Get parameters from the new type info.
1885    TypeLoc OldTL = OldTInfo->getTypeLoc();
1886    if (FunctionProtoTypeLoc *OldProtoLoc
1887                                  = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1888      TypeLoc NewTL = NewTInfo->getTypeLoc();
1889      FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1890      assert(NewProtoLoc && "Missing prototype?");
1891      for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i) {
1892        // FIXME: Variadic templates will break this.
1893        Params.push_back(NewProtoLoc->getArg(i));
1894        SemaRef.CurrentInstantiationScope->InstantiatedLocal(
1895                                                        OldProtoLoc->getArg(i),
1896                                                        NewProtoLoc->getArg(i));
1897      }
1898    }
1899  } else {
1900    // The function type itself was not dependent and therefore no
1901    // substitution occurred. However, we still need to instantiate
1902    // the function parameters themselves.
1903    TypeLoc OldTL = OldTInfo->getTypeLoc();
1904    if (FunctionProtoTypeLoc *OldProtoLoc
1905                                    = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1906      for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
1907        ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
1908        if (!Parm)
1909          return 0;
1910        Params.push_back(Parm);
1911      }
1912    }
1913  }
1914  return NewTInfo;
1915}
1916
1917/// \brief Initializes the common fields of an instantiation function
1918/// declaration (New) from the corresponding fields of its template (Tmpl).
1919///
1920/// \returns true if there was an error
1921bool
1922TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1923                                                    FunctionDecl *Tmpl) {
1924  if (Tmpl->isDeleted())
1925    New->setDeleted();
1926
1927  // If we are performing substituting explicitly-specified template arguments
1928  // or deduced template arguments into a function template and we reach this
1929  // point, we are now past the point where SFINAE applies and have committed
1930  // to keeping the new function template specialization. We therefore
1931  // convert the active template instantiation for the function template
1932  // into a template instantiation for this specific function template
1933  // specialization, which is not a SFINAE context, so that we diagnose any
1934  // further errors in the declaration itself.
1935  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1936  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1937  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1938      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1939    if (FunctionTemplateDecl *FunTmpl
1940          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1941      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1942             "Deduction from the wrong function template?");
1943      (void) FunTmpl;
1944      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1945      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1946      --SemaRef.NonInstantiationEntries;
1947    }
1948  }
1949
1950  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1951  assert(Proto && "Function template without prototype?");
1952
1953  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1954      Proto->getNoReturnAttr()) {
1955    // The function has an exception specification or a "noreturn"
1956    // attribute. Substitute into each of the exception types.
1957    llvm::SmallVector<QualType, 4> Exceptions;
1958    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1959      // FIXME: Poor location information!
1960      QualType T
1961        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1962                            New->getLocation(), New->getDeclName());
1963      if (T.isNull() ||
1964          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1965        continue;
1966
1967      Exceptions.push_back(T);
1968    }
1969
1970    // Rebuild the function type
1971
1972    const FunctionProtoType *NewProto
1973      = New->getType()->getAs<FunctionProtoType>();
1974    assert(NewProto && "Template instantiation without function prototype?");
1975    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1976                                                 NewProto->arg_type_begin(),
1977                                                 NewProto->getNumArgs(),
1978                                                 NewProto->isVariadic(),
1979                                                 NewProto->getTypeQuals(),
1980                                                 Proto->hasExceptionSpec(),
1981                                                 Proto->hasAnyExceptionSpec(),
1982                                                 Exceptions.size(),
1983                                                 Exceptions.data(),
1984                                                 Proto->getExtInfo()));
1985  }
1986
1987  SemaRef.InstantiateAttrs(TemplateArgs, Tmpl, New);
1988
1989  return false;
1990}
1991
1992/// \brief Initializes common fields of an instantiated method
1993/// declaration (New) from the corresponding fields of its template
1994/// (Tmpl).
1995///
1996/// \returns true if there was an error
1997bool
1998TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
1999                                                  CXXMethodDecl *Tmpl) {
2000  if (InitFunctionInstantiation(New, Tmpl))
2001    return true;
2002
2003  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
2004  New->setAccess(Tmpl->getAccess());
2005  if (Tmpl->isVirtualAsWritten())
2006    Record->setMethodAsVirtual(New);
2007
2008  // FIXME: attributes
2009  // FIXME: New needs a pointer to Tmpl
2010  return false;
2011}
2012
2013/// \brief Instantiate the definition of the given function from its
2014/// template.
2015///
2016/// \param PointOfInstantiation the point at which the instantiation was
2017/// required. Note that this is not precisely a "point of instantiation"
2018/// for the function, but it's close.
2019///
2020/// \param Function the already-instantiated declaration of a
2021/// function template specialization or member function of a class template
2022/// specialization.
2023///
2024/// \param Recursive if true, recursively instantiates any functions that
2025/// are required by this instantiation.
2026///
2027/// \param DefinitionRequired if true, then we are performing an explicit
2028/// instantiation where the body of the function is required. Complain if
2029/// there is no such body.
2030void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
2031                                         FunctionDecl *Function,
2032                                         bool Recursive,
2033                                         bool DefinitionRequired) {
2034  if (Function->isInvalidDecl() || Function->hasBody())
2035    return;
2036
2037  // Never instantiate an explicit specialization.
2038  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2039    return;
2040
2041  // Find the function body that we'll be substituting.
2042  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
2043  Stmt *Pattern = 0;
2044  if (PatternDecl)
2045    Pattern = PatternDecl->getBody(PatternDecl);
2046
2047  if (!Pattern) {
2048    if (DefinitionRequired) {
2049      if (Function->getPrimaryTemplate())
2050        Diag(PointOfInstantiation,
2051             diag::err_explicit_instantiation_undefined_func_template)
2052          << Function->getPrimaryTemplate();
2053      else
2054        Diag(PointOfInstantiation,
2055             diag::err_explicit_instantiation_undefined_member)
2056          << 1 << Function->getDeclName() << Function->getDeclContext();
2057
2058      if (PatternDecl)
2059        Diag(PatternDecl->getLocation(),
2060             diag::note_explicit_instantiation_here);
2061      Function->setInvalidDecl();
2062    } else if (Function->getTemplateSpecializationKind()
2063                 == TSK_ExplicitInstantiationDefinition) {
2064      PendingInstantiations.push_back(
2065        std::make_pair(Function, PointOfInstantiation));
2066    }
2067
2068    return;
2069  }
2070
2071  // C++0x [temp.explicit]p9:
2072  //   Except for inline functions, other explicit instantiation declarations
2073  //   have the effect of suppressing the implicit instantiation of the entity
2074  //   to which they refer.
2075  if (Function->getTemplateSpecializationKind()
2076        == TSK_ExplicitInstantiationDeclaration &&
2077      !PatternDecl->isInlined())
2078    return;
2079
2080  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2081  if (Inst)
2082    return;
2083
2084  // If we're performing recursive template instantiation, create our own
2085  // queue of pending implicit instantiations that we will instantiate later,
2086  // while we're still within our own instantiation context.
2087  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2088  if (Recursive)
2089    PendingInstantiations.swap(SavedPendingInstantiations);
2090
2091  EnterExpressionEvaluationContext EvalContext(*this,
2092                                               Sema::PotentiallyEvaluated);
2093  ActOnStartOfFunctionDef(0, Function);
2094
2095  // Introduce a new scope where local variable instantiations will be
2096  // recorded, unless we're actually a member function within a local
2097  // class, in which case we need to merge our results with the parent
2098  // scope (of the enclosing function).
2099  bool MergeWithParentScope = false;
2100  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2101    MergeWithParentScope = Rec->isLocalClass();
2102
2103  LocalInstantiationScope Scope(*this, MergeWithParentScope);
2104
2105  // Introduce the instantiated function parameters into the local
2106  // instantiation scope, and set the parameter names to those used
2107  // in the template.
2108  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
2109    const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
2110    ParmVarDecl *FunctionParam = Function->getParamDecl(I);
2111    FunctionParam->setDeclName(PatternParam->getDeclName());
2112    Scope.InstantiatedLocal(PatternParam, FunctionParam);
2113  }
2114
2115  // Enter the scope of this instantiation. We don't use
2116  // PushDeclContext because we don't have a scope.
2117  DeclContext *PreviousContext = CurContext;
2118  CurContext = Function;
2119
2120  MultiLevelTemplateArgumentList TemplateArgs =
2121    getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
2122
2123  // If this is a constructor, instantiate the member initializers.
2124  if (const CXXConstructorDecl *Ctor =
2125        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2126    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2127                               TemplateArgs);
2128  }
2129
2130  // Instantiate the function body.
2131  StmtResult Body = SubstStmt(Pattern, TemplateArgs);
2132
2133  if (Body.isInvalid())
2134    Function->setInvalidDecl();
2135
2136  ActOnFinishFunctionBody(Function, Body.get(),
2137                          /*IsInstantiation=*/true);
2138
2139  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2140
2141  CurContext = PreviousContext;
2142
2143  DeclGroupRef DG(Function);
2144  Consumer.HandleTopLevelDecl(DG);
2145
2146  // This class may have local implicit instantiations that need to be
2147  // instantiation within this scope.
2148  PerformPendingInstantiations(/*LocalOnly=*/true);
2149  Scope.Exit();
2150
2151  if (Recursive) {
2152    // Instantiate any pending implicit instantiations found during the
2153    // instantiation of this template.
2154    PerformPendingInstantiations();
2155
2156    // Restore the set of pending implicit instantiations.
2157    PendingInstantiations.swap(SavedPendingInstantiations);
2158  }
2159}
2160
2161/// \brief Instantiate the definition of the given variable from its
2162/// template.
2163///
2164/// \param PointOfInstantiation the point at which the instantiation was
2165/// required. Note that this is not precisely a "point of instantiation"
2166/// for the function, but it's close.
2167///
2168/// \param Var the already-instantiated declaration of a static member
2169/// variable of a class template specialization.
2170///
2171/// \param Recursive if true, recursively instantiates any functions that
2172/// are required by this instantiation.
2173///
2174/// \param DefinitionRequired if true, then we are performing an explicit
2175/// instantiation where an out-of-line definition of the member variable
2176/// is required. Complain if there is no such definition.
2177void Sema::InstantiateStaticDataMemberDefinition(
2178                                          SourceLocation PointOfInstantiation,
2179                                                 VarDecl *Var,
2180                                                 bool Recursive,
2181                                                 bool DefinitionRequired) {
2182  if (Var->isInvalidDecl())
2183    return;
2184
2185  // Find the out-of-line definition of this static data member.
2186  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2187  assert(Def && "This data member was not instantiated from a template?");
2188  assert(Def->isStaticDataMember() && "Not a static data member?");
2189  Def = Def->getOutOfLineDefinition();
2190
2191  if (!Def) {
2192    // We did not find an out-of-line definition of this static data member,
2193    // so we won't perform any instantiation. Rather, we rely on the user to
2194    // instantiate this definition (or provide a specialization for it) in
2195    // another translation unit.
2196    if (DefinitionRequired) {
2197      Def = Var->getInstantiatedFromStaticDataMember();
2198      Diag(PointOfInstantiation,
2199           diag::err_explicit_instantiation_undefined_member)
2200        << 2 << Var->getDeclName() << Var->getDeclContext();
2201      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2202    } else if (Var->getTemplateSpecializationKind()
2203                 == TSK_ExplicitInstantiationDefinition) {
2204      PendingInstantiations.push_back(
2205        std::make_pair(Var, PointOfInstantiation));
2206    }
2207
2208    return;
2209  }
2210
2211  // Never instantiate an explicit specialization.
2212  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2213    return;
2214
2215  // C++0x [temp.explicit]p9:
2216  //   Except for inline functions, other explicit instantiation declarations
2217  //   have the effect of suppressing the implicit instantiation of the entity
2218  //   to which they refer.
2219  if (Var->getTemplateSpecializationKind()
2220        == TSK_ExplicitInstantiationDeclaration)
2221    return;
2222
2223  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2224  if (Inst)
2225    return;
2226
2227  // If we're performing recursive template instantiation, create our own
2228  // queue of pending implicit instantiations that we will instantiate later,
2229  // while we're still within our own instantiation context.
2230  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2231  if (Recursive)
2232    PendingInstantiations.swap(SavedPendingInstantiations);
2233
2234  // Enter the scope of this instantiation. We don't use
2235  // PushDeclContext because we don't have a scope.
2236  DeclContext *PreviousContext = CurContext;
2237  CurContext = Var->getDeclContext();
2238
2239  VarDecl *OldVar = Var;
2240  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2241                                          getTemplateInstantiationArgs(Var)));
2242  CurContext = PreviousContext;
2243
2244  if (Var) {
2245    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2246    assert(MSInfo && "Missing member specialization information?");
2247    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2248                                       MSInfo->getPointOfInstantiation());
2249    DeclGroupRef DG(Var);
2250    Consumer.HandleTopLevelDecl(DG);
2251  }
2252
2253  if (Recursive) {
2254    // Instantiate any pending implicit instantiations found during the
2255    // instantiation of this template.
2256    PerformPendingInstantiations();
2257
2258    // Restore the set of pending implicit instantiations.
2259    PendingInstantiations.swap(SavedPendingInstantiations);
2260  }
2261}
2262
2263void
2264Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2265                                 const CXXConstructorDecl *Tmpl,
2266                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2267
2268  llvm::SmallVector<MemInitTy*, 4> NewInits;
2269  bool AnyErrors = false;
2270
2271  // Instantiate all the initializers.
2272  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2273                                            InitsEnd = Tmpl->init_end();
2274       Inits != InitsEnd; ++Inits) {
2275    CXXBaseOrMemberInitializer *Init = *Inits;
2276
2277    SourceLocation LParenLoc, RParenLoc;
2278    ASTOwningVector<Expr*> NewArgs(*this);
2279    llvm::SmallVector<SourceLocation, 4> CommaLocs;
2280
2281    // Instantiate the initializer.
2282    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2283                               LParenLoc, CommaLocs, NewArgs, RParenLoc)) {
2284      AnyErrors = true;
2285      continue;
2286    }
2287
2288    MemInitResult NewInit;
2289    if (Init->isBaseInitializer()) {
2290      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2291                                            TemplateArgs,
2292                                            Init->getSourceLocation(),
2293                                            New->getDeclName());
2294      if (!BaseTInfo) {
2295        AnyErrors = true;
2296        New->setInvalidDecl();
2297        continue;
2298      }
2299
2300      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2301                                     (Expr **)NewArgs.data(),
2302                                     NewArgs.size(),
2303                                     Init->getLParenLoc(),
2304                                     Init->getRParenLoc(),
2305                                     New->getParent());
2306    } else if (Init->isMemberInitializer()) {
2307      FieldDecl *Member;
2308
2309      // Is this an anonymous union?
2310      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2311        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2312                                                      UnionInit, TemplateArgs));
2313      else
2314        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2315                                                      Init->getMember(),
2316                                                      TemplateArgs));
2317
2318      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2319                                       NewArgs.size(),
2320                                       Init->getSourceLocation(),
2321                                       Init->getLParenLoc(),
2322                                       Init->getRParenLoc());
2323    }
2324
2325    if (NewInit.isInvalid()) {
2326      AnyErrors = true;
2327      New->setInvalidDecl();
2328    } else {
2329      // FIXME: It would be nice if ASTOwningVector had a release function.
2330      NewArgs.take();
2331
2332      NewInits.push_back((MemInitTy *)NewInit.get());
2333    }
2334  }
2335
2336  // Assign all the initializers to the new constructor.
2337  ActOnMemInitializers(New,
2338                       /*FIXME: ColonLoc */
2339                       SourceLocation(),
2340                       NewInits.data(), NewInits.size(),
2341                       AnyErrors);
2342}
2343
2344// TODO: this could be templated if the various decl types used the
2345// same method name.
2346static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2347                              ClassTemplateDecl *Instance) {
2348  Pattern = Pattern->getCanonicalDecl();
2349
2350  do {
2351    Instance = Instance->getCanonicalDecl();
2352    if (Pattern == Instance) return true;
2353    Instance = Instance->getInstantiatedFromMemberTemplate();
2354  } while (Instance);
2355
2356  return false;
2357}
2358
2359static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2360                              FunctionTemplateDecl *Instance) {
2361  Pattern = Pattern->getCanonicalDecl();
2362
2363  do {
2364    Instance = Instance->getCanonicalDecl();
2365    if (Pattern == Instance) return true;
2366    Instance = Instance->getInstantiatedFromMemberTemplate();
2367  } while (Instance);
2368
2369  return false;
2370}
2371
2372static bool
2373isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2374                  ClassTemplatePartialSpecializationDecl *Instance) {
2375  Pattern
2376    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2377  do {
2378    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2379                                                Instance->getCanonicalDecl());
2380    if (Pattern == Instance)
2381      return true;
2382    Instance = Instance->getInstantiatedFromMember();
2383  } while (Instance);
2384
2385  return false;
2386}
2387
2388static bool isInstantiationOf(CXXRecordDecl *Pattern,
2389                              CXXRecordDecl *Instance) {
2390  Pattern = Pattern->getCanonicalDecl();
2391
2392  do {
2393    Instance = Instance->getCanonicalDecl();
2394    if (Pattern == Instance) return true;
2395    Instance = Instance->getInstantiatedFromMemberClass();
2396  } while (Instance);
2397
2398  return false;
2399}
2400
2401static bool isInstantiationOf(FunctionDecl *Pattern,
2402                              FunctionDecl *Instance) {
2403  Pattern = Pattern->getCanonicalDecl();
2404
2405  do {
2406    Instance = Instance->getCanonicalDecl();
2407    if (Pattern == Instance) return true;
2408    Instance = Instance->getInstantiatedFromMemberFunction();
2409  } while (Instance);
2410
2411  return false;
2412}
2413
2414static bool isInstantiationOf(EnumDecl *Pattern,
2415                              EnumDecl *Instance) {
2416  Pattern = Pattern->getCanonicalDecl();
2417
2418  do {
2419    Instance = Instance->getCanonicalDecl();
2420    if (Pattern == Instance) return true;
2421    Instance = Instance->getInstantiatedFromMemberEnum();
2422  } while (Instance);
2423
2424  return false;
2425}
2426
2427static bool isInstantiationOf(UsingShadowDecl *Pattern,
2428                              UsingShadowDecl *Instance,
2429                              ASTContext &C) {
2430  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2431}
2432
2433static bool isInstantiationOf(UsingDecl *Pattern,
2434                              UsingDecl *Instance,
2435                              ASTContext &C) {
2436  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2437}
2438
2439static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2440                              UsingDecl *Instance,
2441                              ASTContext &C) {
2442  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2443}
2444
2445static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2446                              UsingDecl *Instance,
2447                              ASTContext &C) {
2448  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2449}
2450
2451static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2452                                              VarDecl *Instance) {
2453  assert(Instance->isStaticDataMember());
2454
2455  Pattern = Pattern->getCanonicalDecl();
2456
2457  do {
2458    Instance = Instance->getCanonicalDecl();
2459    if (Pattern == Instance) return true;
2460    Instance = Instance->getInstantiatedFromStaticDataMember();
2461  } while (Instance);
2462
2463  return false;
2464}
2465
2466// Other is the prospective instantiation
2467// D is the prospective pattern
2468static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2469  if (D->getKind() != Other->getKind()) {
2470    if (UnresolvedUsingTypenameDecl *UUD
2471          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2472      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2473        return isInstantiationOf(UUD, UD, Ctx);
2474      }
2475    }
2476
2477    if (UnresolvedUsingValueDecl *UUD
2478          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2479      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2480        return isInstantiationOf(UUD, UD, Ctx);
2481      }
2482    }
2483
2484    return false;
2485  }
2486
2487  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2488    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2489
2490  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2491    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2492
2493  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2494    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2495
2496  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2497    if (Var->isStaticDataMember())
2498      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2499
2500  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2501    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2502
2503  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2504    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2505
2506  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2507        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2508    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2509                             PartialSpec);
2510
2511  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2512    if (!Field->getDeclName()) {
2513      // This is an unnamed field.
2514      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2515        cast<FieldDecl>(D);
2516    }
2517  }
2518
2519  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2520    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2521
2522  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2523    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2524
2525  return D->getDeclName() && isa<NamedDecl>(Other) &&
2526    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2527}
2528
2529template<typename ForwardIterator>
2530static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2531                                      NamedDecl *D,
2532                                      ForwardIterator first,
2533                                      ForwardIterator last) {
2534  for (; first != last; ++first)
2535    if (isInstantiationOf(Ctx, D, *first))
2536      return cast<NamedDecl>(*first);
2537
2538  return 0;
2539}
2540
2541/// \brief Finds the instantiation of the given declaration context
2542/// within the current instantiation.
2543///
2544/// \returns NULL if there was an error
2545DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2546                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2547  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2548    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2549    return cast_or_null<DeclContext>(ID);
2550  } else return DC;
2551}
2552
2553/// \brief Find the instantiation of the given declaration within the
2554/// current instantiation.
2555///
2556/// This routine is intended to be used when \p D is a declaration
2557/// referenced from within a template, that needs to mapped into the
2558/// corresponding declaration within an instantiation. For example,
2559/// given:
2560///
2561/// \code
2562/// template<typename T>
2563/// struct X {
2564///   enum Kind {
2565///     KnownValue = sizeof(T)
2566///   };
2567///
2568///   bool getKind() const { return KnownValue; }
2569/// };
2570///
2571/// template struct X<int>;
2572/// \endcode
2573///
2574/// In the instantiation of X<int>::getKind(), we need to map the
2575/// EnumConstantDecl for KnownValue (which refers to
2576/// X<T>::<Kind>::KnownValue) to its instantiation
2577/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2578/// this mapping from within the instantiation of X<int>.
2579NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2580                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2581  DeclContext *ParentDC = D->getDeclContext();
2582  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2583      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2584      (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext())) {
2585    // D is a local of some kind. Look into the map of local
2586    // declarations to their instantiations.
2587    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2588  }
2589
2590  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2591    if (!Record->isDependentContext())
2592      return D;
2593
2594    // If the RecordDecl is actually the injected-class-name or a
2595    // "templated" declaration for a class template, class template
2596    // partial specialization, or a member class of a class template,
2597    // substitute into the injected-class-name of the class template
2598    // or partial specialization to find the new DeclContext.
2599    QualType T;
2600    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2601
2602    if (ClassTemplate) {
2603      T = ClassTemplate->getInjectedClassNameSpecialization();
2604    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2605                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2606      ClassTemplate = PartialSpec->getSpecializedTemplate();
2607
2608      // If we call SubstType with an InjectedClassNameType here we
2609      // can end up in an infinite loop.
2610      T = Context.getTypeDeclType(Record);
2611      assert(isa<InjectedClassNameType>(T) &&
2612             "type of partial specialization is not an InjectedClassNameType");
2613      T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
2614    }
2615
2616    if (!T.isNull()) {
2617      // Substitute into the injected-class-name to get the type
2618      // corresponding to the instantiation we want, which may also be
2619      // the current instantiation (if we're in a template
2620      // definition). This substitution should never fail, since we
2621      // know we can instantiate the injected-class-name or we
2622      // wouldn't have gotten to the injected-class-name!
2623
2624      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2625      // extra instantiation in the common case?
2626      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2627      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2628
2629      if (!T->isDependentType()) {
2630        assert(T->isRecordType() && "Instantiation must produce a record type");
2631        return T->getAs<RecordType>()->getDecl();
2632      }
2633
2634      // We are performing "partial" template instantiation to create
2635      // the member declarations for the members of a class template
2636      // specialization. Therefore, D is actually referring to something
2637      // in the current instantiation. Look through the current
2638      // context, which contains actual instantiations, to find the
2639      // instantiation of the "current instantiation" that D refers
2640      // to.
2641      bool SawNonDependentContext = false;
2642      for (DeclContext *DC = CurContext; !DC->isFileContext();
2643           DC = DC->getParent()) {
2644        if (ClassTemplateSpecializationDecl *Spec
2645                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2646          if (isInstantiationOf(ClassTemplate,
2647                                Spec->getSpecializedTemplate()))
2648            return Spec;
2649
2650        if (!DC->isDependentContext())
2651          SawNonDependentContext = true;
2652      }
2653
2654      // We're performing "instantiation" of a member of the current
2655      // instantiation while we are type-checking the
2656      // definition. Compute the declaration context and return that.
2657      assert(!SawNonDependentContext &&
2658             "No dependent context while instantiating record");
2659      DeclContext *DC = computeDeclContext(T);
2660      assert(DC &&
2661             "Unable to find declaration for the current instantiation");
2662      return cast<CXXRecordDecl>(DC);
2663    }
2664
2665    // Fall through to deal with other dependent record types (e.g.,
2666    // anonymous unions in class templates).
2667  }
2668
2669  if (!ParentDC->isDependentContext())
2670    return D;
2671
2672  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2673  if (!ParentDC)
2674    return 0;
2675
2676  if (ParentDC != D->getDeclContext()) {
2677    // We performed some kind of instantiation in the parent context,
2678    // so now we need to look into the instantiated parent context to
2679    // find the instantiation of the declaration D.
2680
2681    // If our context used to be dependent, we may need to instantiate
2682    // it before performing lookup into that context.
2683    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2684      if (!Spec->isDependentContext()) {
2685        QualType T = Context.getTypeDeclType(Spec);
2686        const RecordType *Tag = T->getAs<RecordType>();
2687        assert(Tag && "type of non-dependent record is not a RecordType");
2688        if (!Tag->isBeingDefined() &&
2689            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2690          return 0;
2691      }
2692    }
2693
2694    NamedDecl *Result = 0;
2695    if (D->getDeclName()) {
2696      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2697      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2698    } else {
2699      // Since we don't have a name for the entity we're looking for,
2700      // our only option is to walk through all of the declarations to
2701      // find that name. This will occur in a few cases:
2702      //
2703      //   - anonymous struct/union within a template
2704      //   - unnamed class/struct/union/enum within a template
2705      //
2706      // FIXME: Find a better way to find these instantiations!
2707      Result = findInstantiationOf(Context, D,
2708                                   ParentDC->decls_begin(),
2709                                   ParentDC->decls_end());
2710    }
2711
2712    // UsingShadowDecls can instantiate to nothing because of using hiding.
2713    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2714            cast<Decl>(ParentDC)->isInvalidDecl())
2715           && "Unable to find instantiation of declaration!");
2716
2717    D = Result;
2718  }
2719
2720  return D;
2721}
2722
2723/// \brief Performs template instantiation for all implicit template
2724/// instantiations we have seen until this point.
2725void Sema::PerformPendingInstantiations(bool LocalOnly) {
2726  while (!PendingLocalImplicitInstantiations.empty() ||
2727         (!LocalOnly && !PendingInstantiations.empty())) {
2728    PendingImplicitInstantiation Inst;
2729
2730    if (PendingLocalImplicitInstantiations.empty()) {
2731      Inst = PendingInstantiations.front();
2732      PendingInstantiations.pop_front();
2733    } else {
2734      Inst = PendingLocalImplicitInstantiations.front();
2735      PendingLocalImplicitInstantiations.pop_front();
2736    }
2737
2738    // Instantiate function definitions
2739    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2740      PrettyDeclStackTraceEntry CrashInfo(*this, Function, SourceLocation(),
2741                                          "instantiating function definition");
2742      bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
2743                                TSK_ExplicitInstantiationDefinition;
2744      InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true,
2745                                    DefinitionRequired);
2746      continue;
2747    }
2748
2749    // Instantiate static data member definitions.
2750    VarDecl *Var = cast<VarDecl>(Inst.first);
2751    assert(Var->isStaticDataMember() && "Not a static data member?");
2752
2753    // Don't try to instantiate declarations if the most recent redeclaration
2754    // is invalid.
2755    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2756      continue;
2757
2758    // Check if the most recent declaration has changed the specialization kind
2759    // and removed the need for implicit instantiation.
2760    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2761    case TSK_Undeclared:
2762      assert(false && "Cannot instantitiate an undeclared specialization.");
2763    case TSK_ExplicitInstantiationDeclaration:
2764    case TSK_ExplicitSpecialization:
2765      continue;  // No longer need to instantiate this type.
2766    case TSK_ExplicitInstantiationDefinition:
2767      // We only need an instantiation if the pending instantiation *is* the
2768      // explicit instantiation.
2769      if (Var != Var->getMostRecentDeclaration()) continue;
2770    case TSK_ImplicitInstantiation:
2771      break;
2772    }
2773
2774    PrettyDeclStackTraceEntry CrashInfo(*this, Var, Var->getLocation(),
2775                                        "instantiating static data member "
2776                                        "definition");
2777
2778    bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
2779                              TSK_ExplicitInstantiationDefinition;
2780    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true,
2781                                          DefinitionRequired);
2782  }
2783}
2784
2785void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2786                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2787  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2788         E = Pattern->ddiag_end(); I != E; ++I) {
2789    DependentDiagnostic *DD = *I;
2790
2791    switch (DD->getKind()) {
2792    case DependentDiagnostic::Access:
2793      HandleDependentAccessCheck(*DD, TemplateArgs);
2794      break;
2795    }
2796  }
2797}
2798
2799