SemaTemplateInstantiateDecl.cpp revision d226f65006733ed7f709c3174f22ce33391cb58f 
1//===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//===----------------------------------------------------------------------===/
8//
9//  This file implements C++ template instantiation for declarations.
10//
11//===----------------------------------------------------------------------===/
12#include "clang/Sema/Sema.h"
13#include "clang/Sema/Lookup.h"
14#include "clang/AST/ASTConsumer.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/DeclTemplate.h"
17#include "clang/AST/DeclVisitor.h"
18#include "clang/AST/DependentDiagnostic.h"
19#include "clang/AST/Expr.h"
20#include "clang/AST/ExprCXX.h"
21#include "clang/AST/TypeLoc.h"
22#include "clang/Basic/PrettyStackTrace.h"
23#include "clang/Lex/Preprocessor.h"
24
25using namespace clang;
26
27namespace {
28  class TemplateDeclInstantiator
29    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
30    Sema &SemaRef;
31    DeclContext *Owner;
32    const MultiLevelTemplateArgumentList &TemplateArgs;
33
34  public:
35    typedef Sema::OwningExprResult OwningExprResult;
36
37    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
38                             const MultiLevelTemplateArgumentList &TemplateArgs)
39      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
40
41    // FIXME: Once we get closer to completion, replace these manually-written
42    // declarations with automatically-generated ones from
43    // clang/AST/DeclNodes.inc.
44    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
45    Decl *VisitNamespaceDecl(NamespaceDecl *D);
46    Decl *VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
47    Decl *VisitTypedefDecl(TypedefDecl *D);
48    Decl *VisitVarDecl(VarDecl *D);
49    Decl *VisitAccessSpecDecl(AccessSpecDecl *D);
50    Decl *VisitFieldDecl(FieldDecl *D);
51    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
52    Decl *VisitEnumDecl(EnumDecl *D);
53    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
54    Decl *VisitFriendDecl(FriendDecl *D);
55    Decl *VisitFunctionDecl(FunctionDecl *D,
56                            TemplateParameterList *TemplateParams = 0);
57    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
58    Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
59                             TemplateParameterList *TemplateParams = 0);
60    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
61    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
62    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
63    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
64    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
65    Decl *VisitClassTemplatePartialSpecializationDecl(
66                                    ClassTemplatePartialSpecializationDecl *D);
67    Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
68    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
69    Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
70    Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
71    Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
72    Decl *VisitUsingDecl(UsingDecl *D);
73    Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
74    Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
75    Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
76
77    // Base case. FIXME: Remove once we can instantiate everything.
78    Decl *VisitDecl(Decl *D) {
79      unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
80                                                            Diagnostic::Error,
81                                                   "cannot instantiate %0 yet");
82      SemaRef.Diag(D->getLocation(), DiagID)
83        << D->getDeclKindName();
84
85      return 0;
86    }
87
88    // Helper functions for instantiating methods.
89    TypeSourceInfo *SubstFunctionType(FunctionDecl *D,
90                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
91    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
92    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
93
94    TemplateParameterList *
95      SubstTemplateParams(TemplateParameterList *List);
96
97    bool SubstQualifier(const DeclaratorDecl *OldDecl,
98                        DeclaratorDecl *NewDecl);
99    bool SubstQualifier(const TagDecl *OldDecl,
100                        TagDecl *NewDecl);
101
102    bool InstantiateClassTemplatePartialSpecialization(
103                                              ClassTemplateDecl *ClassTemplate,
104                           ClassTemplatePartialSpecializationDecl *PartialSpec);
105  };
106}
107
108bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
109                                              DeclaratorDecl *NewDecl) {
110  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
111  if (!OldQual) return false;
112
113  SourceRange QualRange = OldDecl->getQualifierRange();
114
115  NestedNameSpecifier *NewQual
116    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
117  if (!NewQual)
118    return true;
119
120  NewDecl->setQualifierInfo(NewQual, QualRange);
121  return false;
122}
123
124bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
125                                              TagDecl *NewDecl) {
126  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
127  if (!OldQual) return false;
128
129  SourceRange QualRange = OldDecl->getQualifierRange();
130
131  NestedNameSpecifier *NewQual
132    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
133  if (!NewQual)
134    return true;
135
136  NewDecl->setQualifierInfo(NewQual, QualRange);
137  return false;
138}
139
140// FIXME: Is this still too simple?
141void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
142                            Decl *Tmpl, Decl *New) {
143  for (AttrVec::const_iterator i = Tmpl->attr_begin(), e = Tmpl->attr_end();
144       i != e; ++i) {
145    const Attr *TmplAttr = *i;
146    // FIXME: This should be generalized to more than just the AlignedAttr.
147    if (const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr)) {
148      if (Aligned->isAlignmentDependent()) {
149        // The alignment expression is not potentially evaluated.
150        EnterExpressionEvaluationContext Unevaluated(*this,
151                                                     Action::Unevaluated);
152
153        if (Aligned->isAlignmentExpr()) {
154          OwningExprResult Result = SubstExpr(Aligned->getAlignmentExpr(),
155                                              TemplateArgs);
156          if (!Result.isInvalid())
157            AddAlignedAttr(Aligned->getLocation(), New, Result.takeAs<Expr>());
158        }
159        else {
160          TypeSourceInfo *Result = SubstType(Aligned->getAlignmentType(),
161                                              TemplateArgs,
162                                              Aligned->getLocation(),
163                                              DeclarationName());
164          if (Result)
165            AddAlignedAttr(Aligned->getLocation(), New, Result);
166        }
167        continue;
168      }
169    }
170
171    // FIXME: Is cloning correct for all attributes?
172    Attr *NewAttr = TmplAttr->clone(Context);
173    New->addAttr(NewAttr);
174  }
175}
176
177Decl *
178TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
179  assert(false && "Translation units cannot be instantiated");
180  return D;
181}
182
183Decl *
184TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
185  assert(false && "Namespaces cannot be instantiated");
186  return D;
187}
188
189Decl *
190TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
191  NamespaceAliasDecl *Inst
192    = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
193                                 D->getNamespaceLoc(),
194                                 D->getAliasLoc(),
195                                 D->getNamespace()->getIdentifier(),
196                                 D->getQualifierRange(),
197                                 D->getQualifier(),
198                                 D->getTargetNameLoc(),
199                                 D->getNamespace());
200  Owner->addDecl(Inst);
201  return Inst;
202}
203
204Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
205  bool Invalid = false;
206  TypeSourceInfo *DI = D->getTypeSourceInfo();
207  if (DI->getType()->isDependentType() ||
208      DI->getType()->isVariablyModifiedType()) {
209    DI = SemaRef.SubstType(DI, TemplateArgs,
210                           D->getLocation(), D->getDeclName());
211    if (!DI) {
212      Invalid = true;
213      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
214    }
215  } else {
216    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
217  }
218
219  // Create the new typedef
220  TypedefDecl *Typedef
221    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
222                          D->getIdentifier(), DI);
223  if (Invalid)
224    Typedef->setInvalidDecl();
225
226  if (const TagType *TT = DI->getType()->getAs<TagType>()) {
227    TagDecl *TD = TT->getDecl();
228
229    // If the TagDecl that the TypedefDecl points to is an anonymous decl
230    // keep track of the TypedefDecl.
231    if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl())
232      TD->setTypedefForAnonDecl(Typedef);
233  }
234
235  if (TypedefDecl *Prev = D->getPreviousDeclaration()) {
236    NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
237                                                       TemplateArgs);
238    Typedef->setPreviousDeclaration(cast<TypedefDecl>(InstPrev));
239  }
240
241  SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef);
242
243  Typedef->setAccess(D->getAccess());
244  Owner->addDecl(Typedef);
245
246  return Typedef;
247}
248
249/// \brief Instantiate the arguments provided as part of initialization.
250///
251/// \returns true if an error occurred, false otherwise.
252static bool InstantiateInitializationArguments(Sema &SemaRef,
253                                               Expr **Args, unsigned NumArgs,
254                           const MultiLevelTemplateArgumentList &TemplateArgs,
255                         llvm::SmallVectorImpl<SourceLocation> &FakeCommaLocs,
256                           ASTOwningVector<&ActionBase::DeleteExpr> &InitArgs) {
257  for (unsigned I = 0; I != NumArgs; ++I) {
258    // When we hit the first defaulted argument, break out of the loop:
259    // we don't pass those default arguments on.
260    if (Args[I]->isDefaultArgument())
261      break;
262
263    Sema::OwningExprResult Arg = SemaRef.SubstExpr(Args[I], TemplateArgs);
264    if (Arg.isInvalid())
265      return true;
266
267    Expr *ArgExpr = (Expr *)Arg.get();
268    InitArgs.push_back(Arg.release());
269
270    // FIXME: We're faking all of the comma locations. Do we need them?
271    FakeCommaLocs.push_back(
272                          SemaRef.PP.getLocForEndOfToken(ArgExpr->getLocEnd()));
273  }
274
275  return false;
276}
277
278/// \brief Instantiate an initializer, breaking it into separate
279/// initialization arguments.
280///
281/// \param S The semantic analysis object.
282///
283/// \param Init The initializer to instantiate.
284///
285/// \param TemplateArgs Template arguments to be substituted into the
286/// initializer.
287///
288/// \param NewArgs Will be filled in with the instantiation arguments.
289///
290/// \returns true if an error occurred, false otherwise
291static bool InstantiateInitializer(Sema &S, Expr *Init,
292                            const MultiLevelTemplateArgumentList &TemplateArgs,
293                                   SourceLocation &LParenLoc,
294                               llvm::SmallVector<SourceLocation, 4> &CommaLocs,
295                             ASTOwningVector<&ActionBase::DeleteExpr> &NewArgs,
296                                   SourceLocation &RParenLoc) {
297  NewArgs.clear();
298  LParenLoc = SourceLocation();
299  RParenLoc = SourceLocation();
300
301  if (!Init)
302    return false;
303
304  if (CXXExprWithTemporaries *ExprTemp = dyn_cast<CXXExprWithTemporaries>(Init))
305    Init = ExprTemp->getSubExpr();
306
307  while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init))
308    Init = Binder->getSubExpr();
309
310  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
311    Init = ICE->getSubExprAsWritten();
312
313  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
314    LParenLoc = ParenList->getLParenLoc();
315    RParenLoc = ParenList->getRParenLoc();
316    return InstantiateInitializationArguments(S, ParenList->getExprs(),
317                                              ParenList->getNumExprs(),
318                                              TemplateArgs, CommaLocs,
319                                              NewArgs);
320  }
321
322  if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) {
323    if (!isa<CXXTemporaryObjectExpr>(Construct)) {
324      if (InstantiateInitializationArguments(S,
325                                             Construct->getArgs(),
326                                             Construct->getNumArgs(),
327                                             TemplateArgs,
328                                             CommaLocs, NewArgs))
329        return true;
330
331      // FIXME: Fake locations!
332      LParenLoc = S.PP.getLocForEndOfToken(Init->getLocStart());
333      RParenLoc = CommaLocs.empty()? LParenLoc : CommaLocs.back();
334      return false;
335    }
336  }
337
338  Sema::OwningExprResult Result = S.SubstExpr(Init, TemplateArgs);
339  if (Result.isInvalid())
340    return true;
341
342  NewArgs.push_back(Result.takeAs<Expr>());
343  return false;
344}
345
346Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
347  // If this is the variable for an anonymous struct or union,
348  // instantiate the anonymous struct/union type first.
349  if (const RecordType *RecordTy = D->getType()->getAs<RecordType>())
350    if (RecordTy->getDecl()->isAnonymousStructOrUnion())
351      if (!VisitCXXRecordDecl(cast<CXXRecordDecl>(RecordTy->getDecl())))
352        return 0;
353
354  // Do substitution on the type of the declaration
355  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
356                                         TemplateArgs,
357                                         D->getTypeSpecStartLoc(),
358                                         D->getDeclName());
359  if (!DI)
360    return 0;
361
362  // Build the instantiated declaration
363  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
364                                 D->getLocation(), D->getIdentifier(),
365                                 DI->getType(), DI,
366                                 D->getStorageClass(),
367                                 D->getStorageClassAsWritten());
368  Var->setThreadSpecified(D->isThreadSpecified());
369  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
370
371  // Substitute the nested name specifier, if any.
372  if (SubstQualifier(D, Var))
373    return 0;
374
375  // If we are instantiating a static data member defined
376  // out-of-line, the instantiation will have the same lexical
377  // context (which will be a namespace scope) as the template.
378  if (D->isOutOfLine())
379    Var->setLexicalDeclContext(D->getLexicalDeclContext());
380
381  Var->setAccess(D->getAccess());
382
383  if (!D->isStaticDataMember())
384    Var->setUsed(D->isUsed(false));
385
386  // FIXME: In theory, we could have a previous declaration for variables that
387  // are not static data members.
388  bool Redeclaration = false;
389  // FIXME: having to fake up a LookupResult is dumb.
390  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
391                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
392  if (D->isStaticDataMember())
393    SemaRef.LookupQualifiedName(Previous, Owner, false);
394  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
395
396  if (D->isOutOfLine()) {
397    if (!D->isStaticDataMember())
398      D->getLexicalDeclContext()->addDecl(Var);
399    Owner->makeDeclVisibleInContext(Var);
400  } else {
401    Owner->addDecl(Var);
402    if (Owner->isFunctionOrMethod())
403      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Var);
404  }
405  SemaRef.InstantiateAttrs(TemplateArgs, D, Var);
406
407  // Link instantiations of static data members back to the template from
408  // which they were instantiated.
409  if (Var->isStaticDataMember())
410    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
411                                                     TSK_ImplicitInstantiation);
412
413  if (Var->getAnyInitializer()) {
414    // We already have an initializer in the class.
415  } else if (D->getInit()) {
416    if (Var->isStaticDataMember() && !D->isOutOfLine())
417      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
418    else
419      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
420
421    // Instantiate the initializer.
422    SourceLocation LParenLoc, RParenLoc;
423    llvm::SmallVector<SourceLocation, 4> CommaLocs;
424    ASTOwningVector<&ActionBase::DeleteExpr> InitArgs(SemaRef);
425    if (!InstantiateInitializer(SemaRef, D->getInit(), TemplateArgs, LParenLoc,
426                                CommaLocs, InitArgs, RParenLoc)) {
427      // Attach the initializer to the declaration.
428      if (D->hasCXXDirectInitializer()) {
429        // Add the direct initializer to the declaration.
430        SemaRef.AddCXXDirectInitializerToDecl(Var,
431                                              LParenLoc,
432                                              move_arg(InitArgs),
433                                              CommaLocs.data(),
434                                              RParenLoc);
435      } else if (InitArgs.size() == 1) {
436        Expr *Init = (Expr*)(InitArgs.take()[0]);
437        SemaRef.AddInitializerToDecl(Var,
438                                     SemaRef.Owned(Init),
439                                     false);
440      } else {
441        assert(InitArgs.size() == 0);
442        SemaRef.ActOnUninitializedDecl(Var, false);
443      }
444    } else {
445      // FIXME: Not too happy about invalidating the declaration
446      // because of a bogus initializer.
447      Var->setInvalidDecl();
448    }
449
450    SemaRef.PopExpressionEvaluationContext();
451  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
452    SemaRef.ActOnUninitializedDecl(Var, false);
453
454  // Diagnose unused local variables.
455  if (!Var->isInvalidDecl() && Owner->isFunctionOrMethod() && !Var->isUsed())
456    SemaRef.DiagnoseUnusedDecl(Var);
457
458  return Var;
459}
460
461Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
462  AccessSpecDecl* AD
463    = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
464                             D->getAccessSpecifierLoc(), D->getColonLoc());
465  Owner->addHiddenDecl(AD);
466  return AD;
467}
468
469Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
470  bool Invalid = false;
471  TypeSourceInfo *DI = D->getTypeSourceInfo();
472  if (DI->getType()->isDependentType() ||
473      DI->getType()->isVariablyModifiedType())  {
474    DI = SemaRef.SubstType(DI, TemplateArgs,
475                           D->getLocation(), D->getDeclName());
476    if (!DI) {
477      DI = D->getTypeSourceInfo();
478      Invalid = true;
479    } else if (DI->getType()->isFunctionType()) {
480      // C++ [temp.arg.type]p3:
481      //   If a declaration acquires a function type through a type
482      //   dependent on a template-parameter and this causes a
483      //   declaration that does not use the syntactic form of a
484      //   function declarator to have function type, the program is
485      //   ill-formed.
486      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
487        << DI->getType();
488      Invalid = true;
489    }
490  } else {
491    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
492  }
493
494  Expr *BitWidth = D->getBitWidth();
495  if (Invalid)
496    BitWidth = 0;
497  else if (BitWidth) {
498    // The bit-width expression is not potentially evaluated.
499    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
500
501    OwningExprResult InstantiatedBitWidth
502      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
503    if (InstantiatedBitWidth.isInvalid()) {
504      Invalid = true;
505      BitWidth = 0;
506    } else
507      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
508  }
509
510  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
511                                            DI->getType(), DI,
512                                            cast<RecordDecl>(Owner),
513                                            D->getLocation(),
514                                            D->isMutable(),
515                                            BitWidth,
516                                            D->getTypeSpecStartLoc(),
517                                            D->getAccess(),
518                                            0);
519  if (!Field) {
520    cast<Decl>(Owner)->setInvalidDecl();
521    return 0;
522  }
523
524  SemaRef.InstantiateAttrs(TemplateArgs, D, Field);
525
526  if (Invalid)
527    Field->setInvalidDecl();
528
529  if (!Field->getDeclName()) {
530    // Keep track of where this decl came from.
531    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
532  }
533  if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
534    if (Parent->isAnonymousStructOrUnion() &&
535        Parent->getLookupContext()->isFunctionOrMethod())
536      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
537  }
538
539  Field->setImplicit(D->isImplicit());
540  Field->setAccess(D->getAccess());
541  Owner->addDecl(Field);
542
543  return Field;
544}
545
546Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
547  // Handle friend type expressions by simply substituting template
548  // parameters into the pattern type and checking the result.
549  if (TypeSourceInfo *Ty = D->getFriendType()) {
550    TypeSourceInfo *InstTy =
551      SemaRef.SubstType(Ty, TemplateArgs,
552                        D->getLocation(), DeclarationName());
553    if (!InstTy)
554      return 0;
555
556    FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getFriendLoc(), InstTy);
557    if (!FD)
558      return 0;
559
560    FD->setAccess(AS_public);
561    Owner->addDecl(FD);
562    return FD;
563  }
564
565  NamedDecl *ND = D->getFriendDecl();
566  assert(ND && "friend decl must be a decl or a type!");
567
568  // All of the Visit implementations for the various potential friend
569  // declarations have to be carefully written to work for friend
570  // objects, with the most important detail being that the target
571  // decl should almost certainly not be placed in Owner.
572  Decl *NewND = Visit(ND);
573  if (!NewND) return 0;
574
575  FriendDecl *FD =
576    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
577                       cast<NamedDecl>(NewND), D->getFriendLoc());
578  FD->setAccess(AS_public);
579  Owner->addDecl(FD);
580  return FD;
581}
582
583Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
584  Expr *AssertExpr = D->getAssertExpr();
585
586  // The expression in a static assertion is not potentially evaluated.
587  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
588
589  OwningExprResult InstantiatedAssertExpr
590    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
591  if (InstantiatedAssertExpr.isInvalid())
592    return 0;
593
594  OwningExprResult Message(SemaRef, D->getMessage());
595  D->getMessage()->Retain();
596  return SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
597                                              move(InstantiatedAssertExpr),
598                                              move(Message));
599}
600
601Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
602  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
603                                    D->getLocation(), D->getIdentifier(),
604                                    D->getTagKeywordLoc(),
605                                    /*PrevDecl=*/0);
606  Enum->setInstantiationOfMemberEnum(D);
607  Enum->setAccess(D->getAccess());
608  if (SubstQualifier(D, Enum)) return 0;
609  Owner->addDecl(Enum);
610  Enum->startDefinition();
611
612  if (D->getDeclContext()->isFunctionOrMethod())
613    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
614
615  llvm::SmallVector<Decl*, 4> Enumerators;
616
617  EnumConstantDecl *LastEnumConst = 0;
618  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
619         ECEnd = D->enumerator_end();
620       EC != ECEnd; ++EC) {
621    // The specified value for the enumerator.
622    OwningExprResult Value = SemaRef.Owned((Expr *)0);
623    if (Expr *UninstValue = EC->getInitExpr()) {
624      // The enumerator's value expression is not potentially evaluated.
625      EnterExpressionEvaluationContext Unevaluated(SemaRef,
626                                                   Action::Unevaluated);
627
628      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
629    }
630
631    // Drop the initial value and continue.
632    bool isInvalid = false;
633    if (Value.isInvalid()) {
634      Value = SemaRef.Owned((Expr *)0);
635      isInvalid = true;
636    }
637
638    EnumConstantDecl *EnumConst
639      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
640                                  EC->getLocation(), EC->getIdentifier(),
641                                  move(Value));
642
643    if (isInvalid) {
644      if (EnumConst)
645        EnumConst->setInvalidDecl();
646      Enum->setInvalidDecl();
647    }
648
649    if (EnumConst) {
650      EnumConst->setAccess(Enum->getAccess());
651      Enum->addDecl(EnumConst);
652      Enumerators.push_back(EnumConst);
653      LastEnumConst = EnumConst;
654
655      if (D->getDeclContext()->isFunctionOrMethod()) {
656        // If the enumeration is within a function or method, record the enum
657        // constant as a local.
658        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
659      }
660    }
661  }
662
663  // FIXME: Fixup LBraceLoc and RBraceLoc
664  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
665  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
666                        Enum,
667                        Enumerators.data(), Enumerators.size(),
668                        0, 0);
669
670  return Enum;
671}
672
673Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
674  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
675  return 0;
676}
677
678Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
679  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
680
681  // Create a local instantiation scope for this class template, which
682  // will contain the instantiations of the template parameters.
683  Sema::LocalInstantiationScope Scope(SemaRef);
684  TemplateParameterList *TempParams = D->getTemplateParameters();
685  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
686  if (!InstParams)
687    return NULL;
688
689  CXXRecordDecl *Pattern = D->getTemplatedDecl();
690
691  // Instantiate the qualifier.  We have to do this first in case
692  // we're a friend declaration, because if we are then we need to put
693  // the new declaration in the appropriate context.
694  NestedNameSpecifier *Qualifier = Pattern->getQualifier();
695  if (Qualifier) {
696    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
697                                                 Pattern->getQualifierRange(),
698                                                 TemplateArgs);
699    if (!Qualifier) return 0;
700  }
701
702  CXXRecordDecl *PrevDecl = 0;
703  ClassTemplateDecl *PrevClassTemplate = 0;
704
705  // If this isn't a friend, then it's a member template, in which
706  // case we just want to build the instantiation in the
707  // specialization.  If it is a friend, we want to build it in
708  // the appropriate context.
709  DeclContext *DC = Owner;
710  if (isFriend) {
711    if (Qualifier) {
712      CXXScopeSpec SS;
713      SS.setScopeRep(Qualifier);
714      SS.setRange(Pattern->getQualifierRange());
715      DC = SemaRef.computeDeclContext(SS);
716      if (!DC) return 0;
717    } else {
718      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
719                                           Pattern->getDeclContext(),
720                                           TemplateArgs);
721    }
722
723    // Look for a previous declaration of the template in the owning
724    // context.
725    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
726                   Sema::LookupOrdinaryName, Sema::ForRedeclaration);
727    SemaRef.LookupQualifiedName(R, DC);
728
729    if (R.isSingleResult()) {
730      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
731      if (PrevClassTemplate)
732        PrevDecl = PrevClassTemplate->getTemplatedDecl();
733    }
734
735    if (!PrevClassTemplate && Qualifier) {
736      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
737        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
738        << Pattern->getQualifierRange();
739      return 0;
740    }
741
742    bool AdoptedPreviousTemplateParams = false;
743    if (PrevClassTemplate) {
744      bool Complain = true;
745
746      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
747      // template for struct std::tr1::__detail::_Map_base, where the
748      // template parameters of the friend declaration don't match the
749      // template parameters of the original declaration. In this one
750      // case, we don't complain about the ill-formed friend
751      // declaration.
752      if (isFriend && Pattern->getIdentifier() &&
753          Pattern->getIdentifier()->isStr("_Map_base") &&
754          DC->isNamespace() &&
755          cast<NamespaceDecl>(DC)->getIdentifier() &&
756          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
757        DeclContext *DCParent = DC->getParent();
758        if (DCParent->isNamespace() &&
759            cast<NamespaceDecl>(DCParent)->getIdentifier() &&
760            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
761          DeclContext *DCParent2 = DCParent->getParent();
762          if (DCParent2->isNamespace() &&
763              cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
764              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
765              DCParent2->getParent()->isTranslationUnit())
766            Complain = false;
767        }
768      }
769
770      TemplateParameterList *PrevParams
771        = PrevClassTemplate->getTemplateParameters();
772
773      // Make sure the parameter lists match.
774      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
775                                                  Complain,
776                                                  Sema::TPL_TemplateMatch)) {
777        if (Complain)
778          return 0;
779
780        AdoptedPreviousTemplateParams = true;
781        InstParams = PrevParams;
782      }
783
784      // Do some additional validation, then merge default arguments
785      // from the existing declarations.
786      if (!AdoptedPreviousTemplateParams &&
787          SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
788                                             Sema::TPC_ClassTemplate))
789        return 0;
790    }
791  }
792
793  CXXRecordDecl *RecordInst
794    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
795                            Pattern->getLocation(), Pattern->getIdentifier(),
796                            Pattern->getTagKeywordLoc(), PrevDecl,
797                            /*DelayTypeCreation=*/true);
798
799  if (Qualifier)
800    RecordInst->setQualifierInfo(Qualifier, Pattern->getQualifierRange());
801
802  ClassTemplateDecl *Inst
803    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
804                                D->getIdentifier(), InstParams, RecordInst,
805                                PrevClassTemplate);
806  RecordInst->setDescribedClassTemplate(Inst);
807
808  if (isFriend) {
809    if (PrevClassTemplate)
810      Inst->setAccess(PrevClassTemplate->getAccess());
811    else
812      Inst->setAccess(D->getAccess());
813
814    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
815    // TODO: do we want to track the instantiation progeny of this
816    // friend target decl?
817  } else {
818    Inst->setAccess(D->getAccess());
819    Inst->setInstantiatedFromMemberTemplate(D);
820  }
821
822  // Trigger creation of the type for the instantiation.
823  SemaRef.Context.getInjectedClassNameType(RecordInst,
824                                    Inst->getInjectedClassNameSpecialization());
825
826  // Finish handling of friends.
827  if (isFriend) {
828    DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
829    return Inst;
830  }
831
832  Owner->addDecl(Inst);
833
834  // Instantiate all of the partial specializations of this member class
835  // template.
836  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
837  D->getPartialSpecializations(PartialSpecs);
838  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
839    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
840
841  return Inst;
842}
843
844Decl *
845TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
846                                   ClassTemplatePartialSpecializationDecl *D) {
847  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
848
849  // Lookup the already-instantiated declaration in the instantiation
850  // of the class template and return that.
851  DeclContext::lookup_result Found
852    = Owner->lookup(ClassTemplate->getDeclName());
853  if (Found.first == Found.second)
854    return 0;
855
856  ClassTemplateDecl *InstClassTemplate
857    = dyn_cast<ClassTemplateDecl>(*Found.first);
858  if (!InstClassTemplate)
859    return 0;
860
861  return InstClassTemplate->findPartialSpecInstantiatedFromMember(D);
862}
863
864Decl *
865TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
866  // Create a local instantiation scope for this function template, which
867  // will contain the instantiations of the template parameters and then get
868  // merged with the local instantiation scope for the function template
869  // itself.
870  Sema::LocalInstantiationScope Scope(SemaRef);
871
872  TemplateParameterList *TempParams = D->getTemplateParameters();
873  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
874  if (!InstParams)
875    return NULL;
876
877  FunctionDecl *Instantiated = 0;
878  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
879    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
880                                                                 InstParams));
881  else
882    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
883                                                          D->getTemplatedDecl(),
884                                                                InstParams));
885
886  if (!Instantiated)
887    return 0;
888
889  Instantiated->setAccess(D->getAccess());
890
891  // Link the instantiated function template declaration to the function
892  // template from which it was instantiated.
893  FunctionTemplateDecl *InstTemplate
894    = Instantiated->getDescribedFunctionTemplate();
895  InstTemplate->setAccess(D->getAccess());
896  assert(InstTemplate &&
897         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
898
899  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
900
901  // Link the instantiation back to the pattern *unless* this is a
902  // non-definition friend declaration.
903  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
904      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
905    InstTemplate->setInstantiatedFromMemberTemplate(D);
906
907  // Make declarations visible in the appropriate context.
908  if (!isFriend)
909    Owner->addDecl(InstTemplate);
910
911  return InstTemplate;
912}
913
914Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
915  CXXRecordDecl *PrevDecl = 0;
916  if (D->isInjectedClassName())
917    PrevDecl = cast<CXXRecordDecl>(Owner);
918  else if (D->getPreviousDeclaration()) {
919    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
920                                                   D->getPreviousDeclaration(),
921                                                   TemplateArgs);
922    if (!Prev) return 0;
923    PrevDecl = cast<CXXRecordDecl>(Prev);
924  }
925
926  CXXRecordDecl *Record
927    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
928                            D->getLocation(), D->getIdentifier(),
929                            D->getTagKeywordLoc(), PrevDecl);
930
931  // Substitute the nested name specifier, if any.
932  if (SubstQualifier(D, Record))
933    return 0;
934
935  Record->setImplicit(D->isImplicit());
936  // FIXME: Check against AS_none is an ugly hack to work around the issue that
937  // the tag decls introduced by friend class declarations don't have an access
938  // specifier. Remove once this area of the code gets sorted out.
939  if (D->getAccess() != AS_none)
940    Record->setAccess(D->getAccess());
941  if (!D->isInjectedClassName())
942    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
943
944  // If the original function was part of a friend declaration,
945  // inherit its namespace state.
946  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
947    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
948
949  // Make sure that anonymous structs and unions are recorded.
950  if (D->isAnonymousStructOrUnion()) {
951    Record->setAnonymousStructOrUnion(true);
952    if (Record->getDeclContext()->getLookupContext()->isFunctionOrMethod())
953      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
954  }
955
956  Owner->addDecl(Record);
957  return Record;
958}
959
960/// Normal class members are of more specific types and therefore
961/// don't make it here.  This function serves two purposes:
962///   1) instantiating function templates
963///   2) substituting friend declarations
964/// FIXME: preserve function definitions in case #2
965Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
966                                       TemplateParameterList *TemplateParams) {
967  // Check whether there is already a function template specialization for
968  // this declaration.
969  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
970  void *InsertPos = 0;
971  if (FunctionTemplate && !TemplateParams) {
972    std::pair<const TemplateArgument *, unsigned> Innermost
973      = TemplateArgs.getInnermost();
974
975    FunctionDecl *SpecFunc
976      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
977                                             InsertPos);
978
979    // If we already have a function template specialization, return it.
980    if (SpecFunc)
981      return SpecFunc;
982  }
983
984  bool isFriend;
985  if (FunctionTemplate)
986    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
987  else
988    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
989
990  bool MergeWithParentScope = (TemplateParams != 0) ||
991    Owner->isFunctionOrMethod() ||
992    !(isa<Decl>(Owner) &&
993      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
994  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
995
996  llvm::SmallVector<ParmVarDecl *, 4> Params;
997  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
998  TInfo = SubstFunctionType(D, Params);
999  if (!TInfo)
1000    return 0;
1001  QualType T = TInfo->getType();
1002
1003  NestedNameSpecifier *Qualifier = D->getQualifier();
1004  if (Qualifier) {
1005    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1006                                                 D->getQualifierRange(),
1007                                                 TemplateArgs);
1008    if (!Qualifier) return 0;
1009  }
1010
1011  // If we're instantiating a local function declaration, put the result
1012  // in the owner;  otherwise we need to find the instantiated context.
1013  DeclContext *DC;
1014  if (D->getDeclContext()->isFunctionOrMethod())
1015    DC = Owner;
1016  else if (isFriend && Qualifier) {
1017    CXXScopeSpec SS;
1018    SS.setScopeRep(Qualifier);
1019    SS.setRange(D->getQualifierRange());
1020    DC = SemaRef.computeDeclContext(SS);
1021    if (!DC) return 0;
1022  } else {
1023    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1024                                         TemplateArgs);
1025  }
1026
1027  FunctionDecl *Function =
1028      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
1029                           D->getDeclName(), T, TInfo,
1030                           D->getStorageClass(), D->getStorageClassAsWritten(),
1031                           D->isInlineSpecified(), D->hasWrittenPrototype());
1032
1033  if (Qualifier)
1034    Function->setQualifierInfo(Qualifier, D->getQualifierRange());
1035
1036  DeclContext *LexicalDC = Owner;
1037  if (!isFriend && D->isOutOfLine()) {
1038    assert(D->getDeclContext()->isFileContext());
1039    LexicalDC = D->getDeclContext();
1040  }
1041
1042  Function->setLexicalDeclContext(LexicalDC);
1043
1044  // Attach the parameters
1045  for (unsigned P = 0; P < Params.size(); ++P)
1046    Params[P]->setOwningFunction(Function);
1047  Function->setParams(Params.data(), Params.size());
1048
1049  SourceLocation InstantiateAtPOI;
1050  if (TemplateParams) {
1051    // Our resulting instantiation is actually a function template, since we
1052    // are substituting only the outer template parameters. For example, given
1053    //
1054    //   template<typename T>
1055    //   struct X {
1056    //     template<typename U> friend void f(T, U);
1057    //   };
1058    //
1059    //   X<int> x;
1060    //
1061    // We are instantiating the friend function template "f" within X<int>,
1062    // which means substituting int for T, but leaving "f" as a friend function
1063    // template.
1064    // Build the function template itself.
1065    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1066                                                    Function->getLocation(),
1067                                                    Function->getDeclName(),
1068                                                    TemplateParams, Function);
1069    Function->setDescribedFunctionTemplate(FunctionTemplate);
1070
1071    FunctionTemplate->setLexicalDeclContext(LexicalDC);
1072
1073    if (isFriend && D->isThisDeclarationADefinition()) {
1074      // TODO: should we remember this connection regardless of whether
1075      // the friend declaration provided a body?
1076      FunctionTemplate->setInstantiatedFromMemberTemplate(
1077                                           D->getDescribedFunctionTemplate());
1078    }
1079  } else if (FunctionTemplate) {
1080    // Record this function template specialization.
1081    std::pair<const TemplateArgument *, unsigned> Innermost
1082      = TemplateArgs.getInnermost();
1083    Function->setFunctionTemplateSpecialization(FunctionTemplate,
1084                  new (SemaRef.Context) TemplateArgumentList(SemaRef.Context,
1085                                                             Innermost.first,
1086                                                             Innermost.second),
1087                                                InsertPos);
1088  } else if (isFriend && D->isThisDeclarationADefinition()) {
1089    // TODO: should we remember this connection regardless of whether
1090    // the friend declaration provided a body?
1091    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1092  }
1093
1094  if (InitFunctionInstantiation(Function, D))
1095    Function->setInvalidDecl();
1096
1097  bool Redeclaration = false;
1098  bool OverloadableAttrRequired = false;
1099  bool isExplicitSpecialization = false;
1100
1101  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1102                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1103
1104  if (DependentFunctionTemplateSpecializationInfo *Info
1105        = D->getDependentSpecializationInfo()) {
1106    assert(isFriend && "non-friend has dependent specialization info?");
1107
1108    // This needs to be set now for future sanity.
1109    Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1110
1111    // Instantiate the explicit template arguments.
1112    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1113                                          Info->getRAngleLoc());
1114    for (unsigned I = 0, E = Info->getNumTemplateArgs(); I != E; ++I) {
1115      TemplateArgumentLoc Loc;
1116      if (SemaRef.Subst(Info->getTemplateArg(I), Loc, TemplateArgs))
1117        return 0;
1118
1119      ExplicitArgs.addArgument(Loc);
1120    }
1121
1122    // Map the candidate templates to their instantiations.
1123    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1124      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1125                                                Info->getTemplate(I),
1126                                                TemplateArgs);
1127      if (!Temp) return 0;
1128
1129      Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1130    }
1131
1132    if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1133                                                    &ExplicitArgs,
1134                                                    Previous))
1135      Function->setInvalidDecl();
1136
1137    isExplicitSpecialization = true;
1138
1139  } else if (TemplateParams || !FunctionTemplate) {
1140    // Look only into the namespace where the friend would be declared to
1141    // find a previous declaration. This is the innermost enclosing namespace,
1142    // as described in ActOnFriendFunctionDecl.
1143    SemaRef.LookupQualifiedName(Previous, DC);
1144
1145    // In C++, the previous declaration we find might be a tag type
1146    // (class or enum). In this case, the new declaration will hide the
1147    // tag type. Note that this does does not apply if we're declaring a
1148    // typedef (C++ [dcl.typedef]p4).
1149    if (Previous.isSingleTagDecl())
1150      Previous.clear();
1151  }
1152
1153  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1154                                   isExplicitSpecialization, Redeclaration,
1155                                   /*FIXME:*/OverloadableAttrRequired);
1156
1157  NamedDecl *PrincipalDecl = (TemplateParams
1158                              ? cast<NamedDecl>(FunctionTemplate)
1159                              : Function);
1160
1161  // If the original function was part of a friend declaration,
1162  // inherit its namespace state and add it to the owner.
1163  if (isFriend) {
1164    NamedDecl *PrevDecl;
1165    if (TemplateParams)
1166      PrevDecl = FunctionTemplate->getPreviousDeclaration();
1167    else
1168      PrevDecl = Function->getPreviousDeclaration();
1169
1170    PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0);
1171    DC->makeDeclVisibleInContext(PrincipalDecl, /*Recoverable=*/ false);
1172
1173    if (!SemaRef.getLangOptions().CPlusPlus0x &&
1174        D->isThisDeclarationADefinition()) {
1175      // Check for a function body.
1176      const FunctionDecl *Definition = 0;
1177      if (Function->hasBody(Definition) &&
1178          Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1179        SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1180          << Function->getDeclName();
1181        SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1182        Function->setInvalidDecl();
1183      }
1184      // Check for redefinitions due to other instantiations of this or
1185      // a similar friend function.
1186      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1187                                           REnd = Function->redecls_end();
1188                R != REnd; ++R) {
1189        if (*R != Function &&
1190            ((*R)->getFriendObjectKind() != Decl::FOK_None)) {
1191          if (const FunctionDecl *RPattern
1192              = (*R)->getTemplateInstantiationPattern())
1193            if (RPattern->hasBody(RPattern)) {
1194              SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1195                << Function->getDeclName();
1196              SemaRef.Diag((*R)->getLocation(), diag::note_previous_definition);
1197              Function->setInvalidDecl();
1198              break;
1199            }
1200        }
1201      }
1202    }
1203
1204  }
1205
1206  if (Function->isOverloadedOperator() && !DC->isRecord() &&
1207      PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1208    PrincipalDecl->setNonMemberOperator();
1209
1210  return Function;
1211}
1212
1213Decl *
1214TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1215                                      TemplateParameterList *TemplateParams) {
1216  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1217  void *InsertPos = 0;
1218  if (FunctionTemplate && !TemplateParams) {
1219    // We are creating a function template specialization from a function
1220    // template. Check whether there is already a function template
1221    // specialization for this particular set of template arguments.
1222    std::pair<const TemplateArgument *, unsigned> Innermost
1223      = TemplateArgs.getInnermost();
1224
1225    FunctionDecl *SpecFunc
1226      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
1227                                             InsertPos);
1228
1229    // If we already have a function template specialization, return it.
1230    if (SpecFunc)
1231      return SpecFunc;
1232  }
1233
1234  bool isFriend;
1235  if (FunctionTemplate)
1236    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1237  else
1238    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1239
1240  bool MergeWithParentScope = (TemplateParams != 0) ||
1241    !(isa<Decl>(Owner) &&
1242      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1243  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1244
1245  llvm::SmallVector<ParmVarDecl *, 4> Params;
1246  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1247  TInfo = SubstFunctionType(D, Params);
1248  if (!TInfo)
1249    return 0;
1250  QualType T = TInfo->getType();
1251
1252  // \brief If the type of this function is not *directly* a function
1253  // type, then we're instantiating the a function that was declared
1254  // via a typedef, e.g.,
1255  //
1256  //   typedef int functype(int, int);
1257  //   functype func;
1258  //
1259  // In this case, we'll just go instantiate the ParmVarDecls that we
1260  // synthesized in the method declaration.
1261  if (!isa<FunctionProtoType>(T)) {
1262    assert(!Params.size() && "Instantiating type could not yield parameters");
1263    for (unsigned I = 0, N = D->getNumParams(); I != N; ++I) {
1264      ParmVarDecl *P = SemaRef.SubstParmVarDecl(D->getParamDecl(I),
1265                                                TemplateArgs);
1266      if (!P)
1267        return 0;
1268
1269      Params.push_back(P);
1270    }
1271  }
1272
1273  NestedNameSpecifier *Qualifier = D->getQualifier();
1274  if (Qualifier) {
1275    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1276                                                 D->getQualifierRange(),
1277                                                 TemplateArgs);
1278    if (!Qualifier) return 0;
1279  }
1280
1281  DeclContext *DC = Owner;
1282  if (isFriend) {
1283    if (Qualifier) {
1284      CXXScopeSpec SS;
1285      SS.setScopeRep(Qualifier);
1286      SS.setRange(D->getQualifierRange());
1287      DC = SemaRef.computeDeclContext(SS);
1288    } else {
1289      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1290                                           D->getDeclContext(),
1291                                           TemplateArgs);
1292    }
1293    if (!DC) return 0;
1294  }
1295
1296  // Build the instantiated method declaration.
1297  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1298  CXXMethodDecl *Method = 0;
1299
1300  DeclarationNameInfo NameInfo
1301    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1302  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1303    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1304                                        NameInfo, T, TInfo,
1305                                        Constructor->isExplicit(),
1306                                        Constructor->isInlineSpecified(),
1307                                        false);
1308  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1309    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1310                                       NameInfo, T,
1311                                       Destructor->isInlineSpecified(),
1312                                       false);
1313  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1314    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1315                                       NameInfo, T, TInfo,
1316                                       Conversion->isInlineSpecified(),
1317                                       Conversion->isExplicit());
1318  } else {
1319    Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1320                                   NameInfo, T, TInfo,
1321                                   D->isStatic(),
1322                                   D->getStorageClassAsWritten(),
1323                                   D->isInlineSpecified());
1324  }
1325
1326  if (Qualifier)
1327    Method->setQualifierInfo(Qualifier, D->getQualifierRange());
1328
1329  if (TemplateParams) {
1330    // Our resulting instantiation is actually a function template, since we
1331    // are substituting only the outer template parameters. For example, given
1332    //
1333    //   template<typename T>
1334    //   struct X {
1335    //     template<typename U> void f(T, U);
1336    //   };
1337    //
1338    //   X<int> x;
1339    //
1340    // We are instantiating the member template "f" within X<int>, which means
1341    // substituting int for T, but leaving "f" as a member function template.
1342    // Build the function template itself.
1343    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1344                                                    Method->getLocation(),
1345                                                    Method->getDeclName(),
1346                                                    TemplateParams, Method);
1347    if (isFriend) {
1348      FunctionTemplate->setLexicalDeclContext(Owner);
1349      FunctionTemplate->setObjectOfFriendDecl(true);
1350    } else if (D->isOutOfLine())
1351      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1352    Method->setDescribedFunctionTemplate(FunctionTemplate);
1353  } else if (FunctionTemplate) {
1354    // Record this function template specialization.
1355    std::pair<const TemplateArgument *, unsigned> Innermost
1356      = TemplateArgs.getInnermost();
1357    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1358                    new (SemaRef.Context) TemplateArgumentList(SemaRef.Context,
1359                                                              Innermost.first,
1360                                                              Innermost.second),
1361                                              InsertPos);
1362  } else if (!isFriend) {
1363    // Record that this is an instantiation of a member function.
1364    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1365  }
1366
1367  // If we are instantiating a member function defined
1368  // out-of-line, the instantiation will have the same lexical
1369  // context (which will be a namespace scope) as the template.
1370  if (isFriend) {
1371    Method->setLexicalDeclContext(Owner);
1372    Method->setObjectOfFriendDecl(true);
1373  } else if (D->isOutOfLine())
1374    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1375
1376  // Attach the parameters
1377  for (unsigned P = 0; P < Params.size(); ++P)
1378    Params[P]->setOwningFunction(Method);
1379  Method->setParams(Params.data(), Params.size());
1380
1381  if (InitMethodInstantiation(Method, D))
1382    Method->setInvalidDecl();
1383
1384  LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
1385                        Sema::ForRedeclaration);
1386
1387  if (!FunctionTemplate || TemplateParams || isFriend) {
1388    SemaRef.LookupQualifiedName(Previous, Record);
1389
1390    // In C++, the previous declaration we find might be a tag type
1391    // (class or enum). In this case, the new declaration will hide the
1392    // tag type. Note that this does does not apply if we're declaring a
1393    // typedef (C++ [dcl.typedef]p4).
1394    if (Previous.isSingleTagDecl())
1395      Previous.clear();
1396  }
1397
1398  bool Redeclaration = false;
1399  bool OverloadableAttrRequired = false;
1400  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1401                                   /*FIXME:*/OverloadableAttrRequired);
1402
1403  if (D->isPure())
1404    SemaRef.CheckPureMethod(Method, SourceRange());
1405
1406  Method->setAccess(D->getAccess());
1407
1408  if (FunctionTemplate) {
1409    // If there's a function template, let our caller handle it.
1410  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1411    // Don't hide a (potentially) valid declaration with an invalid one.
1412  } else {
1413    NamedDecl *DeclToAdd = (TemplateParams
1414                            ? cast<NamedDecl>(FunctionTemplate)
1415                            : Method);
1416    if (isFriend)
1417      Record->makeDeclVisibleInContext(DeclToAdd);
1418    else
1419      Owner->addDecl(DeclToAdd);
1420  }
1421
1422  return Method;
1423}
1424
1425Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1426  return VisitCXXMethodDecl(D);
1427}
1428
1429Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1430  return VisitCXXMethodDecl(D);
1431}
1432
1433Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1434  return VisitCXXMethodDecl(D);
1435}
1436
1437ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1438  return SemaRef.SubstParmVarDecl(D, TemplateArgs);
1439}
1440
1441Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1442                                                    TemplateTypeParmDecl *D) {
1443  // TODO: don't always clone when decls are refcounted.
1444  const Type* T = D->getTypeForDecl();
1445  assert(T->isTemplateTypeParmType());
1446  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1447
1448  TemplateTypeParmDecl *Inst =
1449    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1450                                 TTPT->getDepth() - 1, TTPT->getIndex(),
1451                                 TTPT->getName(),
1452                                 D->wasDeclaredWithTypename(),
1453                                 D->isParameterPack());
1454
1455  if (D->hasDefaultArgument())
1456    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1457
1458  // Introduce this template parameter's instantiation into the instantiation
1459  // scope.
1460  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1461
1462  return Inst;
1463}
1464
1465Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1466                                                 NonTypeTemplateParmDecl *D) {
1467  // Substitute into the type of the non-type template parameter.
1468  QualType T;
1469  TypeSourceInfo *DI = D->getTypeSourceInfo();
1470  if (DI) {
1471    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1472                           D->getDeclName());
1473    if (DI) T = DI->getType();
1474  } else {
1475    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1476                          D->getDeclName());
1477    DI = 0;
1478  }
1479  if (T.isNull())
1480    return 0;
1481
1482  // Check that this type is acceptable for a non-type template parameter.
1483  bool Invalid = false;
1484  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1485  if (T.isNull()) {
1486    T = SemaRef.Context.IntTy;
1487    Invalid = true;
1488  }
1489
1490  NonTypeTemplateParmDecl *Param
1491    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1492                                      D->getDepth() - 1, D->getPosition(),
1493                                      D->getIdentifier(), T, DI);
1494  if (Invalid)
1495    Param->setInvalidDecl();
1496
1497  Param->setDefaultArgument(D->getDefaultArgument(), false);
1498
1499  // Introduce this template parameter's instantiation into the instantiation
1500  // scope.
1501  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1502  return Param;
1503}
1504
1505Decl *
1506TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1507                                                  TemplateTemplateParmDecl *D) {
1508  // Instantiate the template parameter list of the template template parameter.
1509  TemplateParameterList *TempParams = D->getTemplateParameters();
1510  TemplateParameterList *InstParams;
1511  {
1512    // Perform the actual substitution of template parameters within a new,
1513    // local instantiation scope.
1514    Sema::LocalInstantiationScope Scope(SemaRef);
1515    InstParams = SubstTemplateParams(TempParams);
1516    if (!InstParams)
1517      return NULL;
1518  }
1519
1520  // Build the template template parameter.
1521  TemplateTemplateParmDecl *Param
1522    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1523                                       D->getDepth() - 1, D->getPosition(),
1524                                       D->getIdentifier(), InstParams);
1525  Param->setDefaultArgument(D->getDefaultArgument(), false);
1526
1527  // Introduce this template parameter's instantiation into the instantiation
1528  // scope.
1529  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1530
1531  return Param;
1532}
1533
1534Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1535  // Using directives are never dependent, so they require no explicit
1536
1537  UsingDirectiveDecl *Inst
1538    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1539                                 D->getNamespaceKeyLocation(),
1540                                 D->getQualifierRange(), D->getQualifier(),
1541                                 D->getIdentLocation(),
1542                                 D->getNominatedNamespace(),
1543                                 D->getCommonAncestor());
1544  Owner->addDecl(Inst);
1545  return Inst;
1546}
1547
1548Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1549  // The nested name specifier is non-dependent, so no transformation
1550  // is required. The same holds for the name info.
1551  DeclarationNameInfo NameInfo = D->getNameInfo();
1552
1553  // We only need to do redeclaration lookups if we're in a class
1554  // scope (in fact, it's not really even possible in non-class
1555  // scopes).
1556  bool CheckRedeclaration = Owner->isRecord();
1557
1558  LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
1559                    Sema::ForRedeclaration);
1560
1561  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1562                                       D->getNestedNameRange(),
1563                                       D->getUsingLocation(),
1564                                       D->getTargetNestedNameDecl(),
1565                                       NameInfo,
1566                                       D->isTypeName());
1567
1568  CXXScopeSpec SS;
1569  SS.setScopeRep(D->getTargetNestedNameDecl());
1570  SS.setRange(D->getNestedNameRange());
1571
1572  if (CheckRedeclaration) {
1573    Prev.setHideTags(false);
1574    SemaRef.LookupQualifiedName(Prev, Owner);
1575
1576    // Check for invalid redeclarations.
1577    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1578                                            D->isTypeName(), SS,
1579                                            D->getLocation(), Prev))
1580      NewUD->setInvalidDecl();
1581
1582  }
1583
1584  if (!NewUD->isInvalidDecl() &&
1585      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1586                                      D->getLocation()))
1587    NewUD->setInvalidDecl();
1588
1589  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1590  NewUD->setAccess(D->getAccess());
1591  Owner->addDecl(NewUD);
1592
1593  // Don't process the shadow decls for an invalid decl.
1594  if (NewUD->isInvalidDecl())
1595    return NewUD;
1596
1597  bool isFunctionScope = Owner->isFunctionOrMethod();
1598
1599  // Process the shadow decls.
1600  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1601         I != E; ++I) {
1602    UsingShadowDecl *Shadow = *I;
1603    NamedDecl *InstTarget =
1604      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1605                                                   Shadow->getTargetDecl(),
1606                                                   TemplateArgs));
1607
1608    if (CheckRedeclaration &&
1609        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1610      continue;
1611
1612    UsingShadowDecl *InstShadow
1613      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1614    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1615
1616    if (isFunctionScope)
1617      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1618  }
1619
1620  return NewUD;
1621}
1622
1623Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1624  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1625  return 0;
1626}
1627
1628Decl * TemplateDeclInstantiator
1629    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1630  NestedNameSpecifier *NNS =
1631    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1632                                     D->getTargetNestedNameRange(),
1633                                     TemplateArgs);
1634  if (!NNS)
1635    return 0;
1636
1637  CXXScopeSpec SS;
1638  SS.setRange(D->getTargetNestedNameRange());
1639  SS.setScopeRep(NNS);
1640
1641  // Since NameInfo refers to a typename, it cannot be a C++ special name.
1642  // Hence, no tranformation is required for it.
1643  DeclarationNameInfo NameInfo(D->getDeclName(), D->getLocation());
1644  NamedDecl *UD =
1645    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1646                                  D->getUsingLoc(), SS, NameInfo, 0,
1647                                  /*instantiation*/ true,
1648                                  /*typename*/ true, D->getTypenameLoc());
1649  if (UD)
1650    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1651
1652  return UD;
1653}
1654
1655Decl * TemplateDeclInstantiator
1656    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1657  NestedNameSpecifier *NNS =
1658    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1659                                     D->getTargetNestedNameRange(),
1660                                     TemplateArgs);
1661  if (!NNS)
1662    return 0;
1663
1664  CXXScopeSpec SS;
1665  SS.setRange(D->getTargetNestedNameRange());
1666  SS.setScopeRep(NNS);
1667
1668  DeclarationNameInfo NameInfo
1669    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1670
1671  NamedDecl *UD =
1672    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1673                                  D->getUsingLoc(), SS, NameInfo, 0,
1674                                  /*instantiation*/ true,
1675                                  /*typename*/ false, SourceLocation());
1676  if (UD)
1677    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1678
1679  return UD;
1680}
1681
1682Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1683                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1684  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1685  if (D->isInvalidDecl())
1686    return 0;
1687
1688  return Instantiator.Visit(D);
1689}
1690
1691/// \brief Instantiates a nested template parameter list in the current
1692/// instantiation context.
1693///
1694/// \param L The parameter list to instantiate
1695///
1696/// \returns NULL if there was an error
1697TemplateParameterList *
1698TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1699  // Get errors for all the parameters before bailing out.
1700  bool Invalid = false;
1701
1702  unsigned N = L->size();
1703  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1704  ParamVector Params;
1705  Params.reserve(N);
1706  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1707       PI != PE; ++PI) {
1708    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1709    Params.push_back(D);
1710    Invalid = Invalid || !D || D->isInvalidDecl();
1711  }
1712
1713  // Clean up if we had an error.
1714  if (Invalid)
1715    return NULL;
1716
1717  TemplateParameterList *InstL
1718    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1719                                    L->getLAngleLoc(), &Params.front(), N,
1720                                    L->getRAngleLoc());
1721  return InstL;
1722}
1723
1724/// \brief Instantiate the declaration of a class template partial
1725/// specialization.
1726///
1727/// \param ClassTemplate the (instantiated) class template that is partially
1728// specialized by the instantiation of \p PartialSpec.
1729///
1730/// \param PartialSpec the (uninstantiated) class template partial
1731/// specialization that we are instantiating.
1732///
1733/// \returns true if there was an error, false otherwise.
1734bool
1735TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1736                                            ClassTemplateDecl *ClassTemplate,
1737                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1738  // Create a local instantiation scope for this class template partial
1739  // specialization, which will contain the instantiations of the template
1740  // parameters.
1741  Sema::LocalInstantiationScope Scope(SemaRef);
1742
1743  // Substitute into the template parameters of the class template partial
1744  // specialization.
1745  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1746  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1747  if (!InstParams)
1748    return true;
1749
1750  // Substitute into the template arguments of the class template partial
1751  // specialization.
1752  const TemplateArgumentLoc *PartialSpecTemplateArgs
1753    = PartialSpec->getTemplateArgsAsWritten();
1754  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1755
1756  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1757  for (unsigned I = 0; I != N; ++I) {
1758    TemplateArgumentLoc Loc;
1759    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1760      return true;
1761    InstTemplateArgs.addArgument(Loc);
1762  }
1763
1764
1765  // Check that the template argument list is well-formed for this
1766  // class template.
1767  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1768                                        InstTemplateArgs.size());
1769  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1770                                        PartialSpec->getLocation(),
1771                                        InstTemplateArgs,
1772                                        false,
1773                                        Converted))
1774    return true;
1775
1776  // Figure out where to insert this class template partial specialization
1777  // in the member template's set of class template partial specializations.
1778  void *InsertPos = 0;
1779  ClassTemplateSpecializationDecl *PrevDecl
1780    = ClassTemplate->findPartialSpecialization(Converted.getFlatArguments(),
1781                                                Converted.flatSize(), InsertPos);
1782
1783  // Build the canonical type that describes the converted template
1784  // arguments of the class template partial specialization.
1785  QualType CanonType
1786    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1787                                                  Converted.getFlatArguments(),
1788                                                    Converted.flatSize());
1789
1790  // Build the fully-sugared type for this class template
1791  // specialization as the user wrote in the specialization
1792  // itself. This means that we'll pretty-print the type retrieved
1793  // from the specialization's declaration the way that the user
1794  // actually wrote the specialization, rather than formatting the
1795  // name based on the "canonical" representation used to store the
1796  // template arguments in the specialization.
1797  TypeSourceInfo *WrittenTy
1798    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1799                                                    TemplateName(ClassTemplate),
1800                                                    PartialSpec->getLocation(),
1801                                                    InstTemplateArgs,
1802                                                    CanonType);
1803
1804  if (PrevDecl) {
1805    // We've already seen a partial specialization with the same template
1806    // parameters and template arguments. This can happen, for example, when
1807    // substituting the outer template arguments ends up causing two
1808    // class template partial specializations of a member class template
1809    // to have identical forms, e.g.,
1810    //
1811    //   template<typename T, typename U>
1812    //   struct Outer {
1813    //     template<typename X, typename Y> struct Inner;
1814    //     template<typename Y> struct Inner<T, Y>;
1815    //     template<typename Y> struct Inner<U, Y>;
1816    //   };
1817    //
1818    //   Outer<int, int> outer; // error: the partial specializations of Inner
1819    //                          // have the same signature.
1820    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1821      << WrittenTy;
1822    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1823      << SemaRef.Context.getTypeDeclType(PrevDecl);
1824    return true;
1825  }
1826
1827
1828  // Create the class template partial specialization declaration.
1829  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1830    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
1831                                                     PartialSpec->getTagKind(),
1832                                                     Owner,
1833                                                     PartialSpec->getLocation(),
1834                                                     InstParams,
1835                                                     ClassTemplate,
1836                                                     Converted,
1837                                                     InstTemplateArgs,
1838                                                     CanonType,
1839                                                     0,
1840                             ClassTemplate->getNextPartialSpecSequenceNumber());
1841  // Substitute the nested name specifier, if any.
1842  if (SubstQualifier(PartialSpec, InstPartialSpec))
1843    return 0;
1844
1845  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1846  InstPartialSpec->setTypeAsWritten(WrittenTy);
1847
1848  // Add this partial specialization to the set of class template partial
1849  // specializations.
1850  ClassTemplate->AddPartialSpecialization(InstPartialSpec, InsertPos);
1851  return false;
1852}
1853
1854TypeSourceInfo*
1855TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1856                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1857  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1858  assert(OldTInfo && "substituting function without type source info");
1859  assert(Params.empty() && "parameter vector is non-empty at start");
1860  TypeSourceInfo *NewTInfo
1861    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
1862                                    D->getTypeSpecStartLoc(),
1863                                    D->getDeclName());
1864  if (!NewTInfo)
1865    return 0;
1866
1867  if (NewTInfo != OldTInfo) {
1868    // Get parameters from the new type info.
1869    TypeLoc OldTL = OldTInfo->getTypeLoc();
1870    if (FunctionProtoTypeLoc *OldProtoLoc
1871                                  = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1872      TypeLoc NewTL = NewTInfo->getTypeLoc();
1873      FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1874      assert(NewProtoLoc && "Missing prototype?");
1875      for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i) {
1876        // FIXME: Variadic templates will break this.
1877        Params.push_back(NewProtoLoc->getArg(i));
1878        SemaRef.CurrentInstantiationScope->InstantiatedLocal(
1879                                                        OldProtoLoc->getArg(i),
1880                                                        NewProtoLoc->getArg(i));
1881      }
1882    }
1883  } else {
1884    // The function type itself was not dependent and therefore no
1885    // substitution occurred. However, we still need to instantiate
1886    // the function parameters themselves.
1887    TypeLoc OldTL = OldTInfo->getTypeLoc();
1888    if (FunctionProtoTypeLoc *OldProtoLoc
1889                                    = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1890      for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
1891        ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
1892        if (!Parm)
1893          return 0;
1894        Params.push_back(Parm);
1895      }
1896    }
1897  }
1898  return NewTInfo;
1899}
1900
1901/// \brief Initializes the common fields of an instantiation function
1902/// declaration (New) from the corresponding fields of its template (Tmpl).
1903///
1904/// \returns true if there was an error
1905bool
1906TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1907                                                    FunctionDecl *Tmpl) {
1908  if (Tmpl->isDeleted())
1909    New->setDeleted();
1910
1911  // If we are performing substituting explicitly-specified template arguments
1912  // or deduced template arguments into a function template and we reach this
1913  // point, we are now past the point where SFINAE applies and have committed
1914  // to keeping the new function template specialization. We therefore
1915  // convert the active template instantiation for the function template
1916  // into a template instantiation for this specific function template
1917  // specialization, which is not a SFINAE context, so that we diagnose any
1918  // further errors in the declaration itself.
1919  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1920  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1921  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1922      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1923    if (FunctionTemplateDecl *FunTmpl
1924          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1925      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1926             "Deduction from the wrong function template?");
1927      (void) FunTmpl;
1928      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1929      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1930      --SemaRef.NonInstantiationEntries;
1931    }
1932  }
1933
1934  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1935  assert(Proto && "Function template without prototype?");
1936
1937  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1938      Proto->getNoReturnAttr()) {
1939    // The function has an exception specification or a "noreturn"
1940    // attribute. Substitute into each of the exception types.
1941    llvm::SmallVector<QualType, 4> Exceptions;
1942    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1943      // FIXME: Poor location information!
1944      QualType T
1945        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1946                            New->getLocation(), New->getDeclName());
1947      if (T.isNull() ||
1948          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1949        continue;
1950
1951      Exceptions.push_back(T);
1952    }
1953
1954    // Rebuild the function type
1955
1956    const FunctionProtoType *NewProto
1957      = New->getType()->getAs<FunctionProtoType>();
1958    assert(NewProto && "Template instantiation without function prototype?");
1959    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1960                                                 NewProto->arg_type_begin(),
1961                                                 NewProto->getNumArgs(),
1962                                                 NewProto->isVariadic(),
1963                                                 NewProto->getTypeQuals(),
1964                                                 Proto->hasExceptionSpec(),
1965                                                 Proto->hasAnyExceptionSpec(),
1966                                                 Exceptions.size(),
1967                                                 Exceptions.data(),
1968                                                 Proto->getExtInfo()));
1969  }
1970
1971  SemaRef.InstantiateAttrs(TemplateArgs, Tmpl, New);
1972
1973  return false;
1974}
1975
1976/// \brief Initializes common fields of an instantiated method
1977/// declaration (New) from the corresponding fields of its template
1978/// (Tmpl).
1979///
1980/// \returns true if there was an error
1981bool
1982TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
1983                                                  CXXMethodDecl *Tmpl) {
1984  if (InitFunctionInstantiation(New, Tmpl))
1985    return true;
1986
1987  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
1988  New->setAccess(Tmpl->getAccess());
1989  if (Tmpl->isVirtualAsWritten())
1990    Record->setMethodAsVirtual(New);
1991
1992  // FIXME: attributes
1993  // FIXME: New needs a pointer to Tmpl
1994  return false;
1995}
1996
1997/// \brief Instantiate the definition of the given function from its
1998/// template.
1999///
2000/// \param PointOfInstantiation the point at which the instantiation was
2001/// required. Note that this is not precisely a "point of instantiation"
2002/// for the function, but it's close.
2003///
2004/// \param Function the already-instantiated declaration of a
2005/// function template specialization or member function of a class template
2006/// specialization.
2007///
2008/// \param Recursive if true, recursively instantiates any functions that
2009/// are required by this instantiation.
2010///
2011/// \param DefinitionRequired if true, then we are performing an explicit
2012/// instantiation where the body of the function is required. Complain if
2013/// there is no such body.
2014void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
2015                                         FunctionDecl *Function,
2016                                         bool Recursive,
2017                                         bool DefinitionRequired) {
2018  if (Function->isInvalidDecl() || Function->hasBody())
2019    return;
2020
2021  // Never instantiate an explicit specialization.
2022  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2023    return;
2024
2025  // Find the function body that we'll be substituting.
2026  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
2027  Stmt *Pattern = 0;
2028  if (PatternDecl)
2029    Pattern = PatternDecl->getBody(PatternDecl);
2030
2031  if (!Pattern) {
2032    if (DefinitionRequired) {
2033      if (Function->getPrimaryTemplate())
2034        Diag(PointOfInstantiation,
2035             diag::err_explicit_instantiation_undefined_func_template)
2036          << Function->getPrimaryTemplate();
2037      else
2038        Diag(PointOfInstantiation,
2039             diag::err_explicit_instantiation_undefined_member)
2040          << 1 << Function->getDeclName() << Function->getDeclContext();
2041
2042      if (PatternDecl)
2043        Diag(PatternDecl->getLocation(),
2044             diag::note_explicit_instantiation_here);
2045      Function->setInvalidDecl();
2046    }
2047
2048    return;
2049  }
2050
2051  // C++0x [temp.explicit]p9:
2052  //   Except for inline functions, other explicit instantiation declarations
2053  //   have the effect of suppressing the implicit instantiation of the entity
2054  //   to which they refer.
2055  if (Function->getTemplateSpecializationKind()
2056        == TSK_ExplicitInstantiationDeclaration &&
2057      !PatternDecl->isInlined())
2058    return;
2059
2060  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2061  if (Inst)
2062    return;
2063
2064  // If we're performing recursive template instantiation, create our own
2065  // queue of pending implicit instantiations that we will instantiate later,
2066  // while we're still within our own instantiation context.
2067  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2068  if (Recursive)
2069    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2070
2071  EnterExpressionEvaluationContext EvalContext(*this,
2072                                               Action::PotentiallyEvaluated);
2073  ActOnStartOfFunctionDef(0, Function);
2074
2075  // Introduce a new scope where local variable instantiations will be
2076  // recorded, unless we're actually a member function within a local
2077  // class, in which case we need to merge our results with the parent
2078  // scope (of the enclosing function).
2079  bool MergeWithParentScope = false;
2080  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2081    MergeWithParentScope = Rec->isLocalClass();
2082
2083  LocalInstantiationScope Scope(*this, MergeWithParentScope);
2084
2085  // Introduce the instantiated function parameters into the local
2086  // instantiation scope, and set the parameter names to those used
2087  // in the template.
2088  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
2089    const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
2090    ParmVarDecl *FunctionParam = Function->getParamDecl(I);
2091    FunctionParam->setDeclName(PatternParam->getDeclName());
2092    Scope.InstantiatedLocal(PatternParam, FunctionParam);
2093  }
2094
2095  // Enter the scope of this instantiation. We don't use
2096  // PushDeclContext because we don't have a scope.
2097  DeclContext *PreviousContext = CurContext;
2098  CurContext = Function;
2099
2100  MultiLevelTemplateArgumentList TemplateArgs =
2101    getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
2102
2103  // If this is a constructor, instantiate the member initializers.
2104  if (const CXXConstructorDecl *Ctor =
2105        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2106    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2107                               TemplateArgs);
2108  }
2109
2110  // Instantiate the function body.
2111  OwningStmtResult Body = SubstStmt(Pattern, TemplateArgs);
2112
2113  if (Body.isInvalid())
2114    Function->setInvalidDecl();
2115
2116  ActOnFinishFunctionBody(Function, move(Body),
2117                          /*IsInstantiation=*/true);
2118
2119  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2120
2121  CurContext = PreviousContext;
2122
2123  DeclGroupRef DG(Function);
2124  Consumer.HandleTopLevelDecl(DG);
2125
2126  // This class may have local implicit instantiations that need to be
2127  // instantiation within this scope.
2128  PerformPendingImplicitInstantiations(/*LocalOnly=*/true);
2129  Scope.Exit();
2130
2131  if (Recursive) {
2132    // Instantiate any pending implicit instantiations found during the
2133    // instantiation of this template.
2134    PerformPendingImplicitInstantiations();
2135
2136    // Restore the set of pending implicit instantiations.
2137    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2138  }
2139}
2140
2141/// \brief Instantiate the definition of the given variable from its
2142/// template.
2143///
2144/// \param PointOfInstantiation the point at which the instantiation was
2145/// required. Note that this is not precisely a "point of instantiation"
2146/// for the function, but it's close.
2147///
2148/// \param Var the already-instantiated declaration of a static member
2149/// variable of a class template specialization.
2150///
2151/// \param Recursive if true, recursively instantiates any functions that
2152/// are required by this instantiation.
2153///
2154/// \param DefinitionRequired if true, then we are performing an explicit
2155/// instantiation where an out-of-line definition of the member variable
2156/// is required. Complain if there is no such definition.
2157void Sema::InstantiateStaticDataMemberDefinition(
2158                                          SourceLocation PointOfInstantiation,
2159                                                 VarDecl *Var,
2160                                                 bool Recursive,
2161                                                 bool DefinitionRequired) {
2162  if (Var->isInvalidDecl())
2163    return;
2164
2165  // Find the out-of-line definition of this static data member.
2166  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2167  assert(Def && "This data member was not instantiated from a template?");
2168  assert(Def->isStaticDataMember() && "Not a static data member?");
2169  Def = Def->getOutOfLineDefinition();
2170
2171  if (!Def) {
2172    // We did not find an out-of-line definition of this static data member,
2173    // so we won't perform any instantiation. Rather, we rely on the user to
2174    // instantiate this definition (or provide a specialization for it) in
2175    // another translation unit.
2176    if (DefinitionRequired) {
2177      Def = Var->getInstantiatedFromStaticDataMember();
2178      Diag(PointOfInstantiation,
2179           diag::err_explicit_instantiation_undefined_member)
2180        << 2 << Var->getDeclName() << Var->getDeclContext();
2181      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2182    }
2183
2184    return;
2185  }
2186
2187  // Never instantiate an explicit specialization.
2188  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2189    return;
2190
2191  // C++0x [temp.explicit]p9:
2192  //   Except for inline functions, other explicit instantiation declarations
2193  //   have the effect of suppressing the implicit instantiation of the entity
2194  //   to which they refer.
2195  if (Var->getTemplateSpecializationKind()
2196        == TSK_ExplicitInstantiationDeclaration)
2197    return;
2198
2199  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2200  if (Inst)
2201    return;
2202
2203  // If we're performing recursive template instantiation, create our own
2204  // queue of pending implicit instantiations that we will instantiate later,
2205  // while we're still within our own instantiation context.
2206  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2207  if (Recursive)
2208    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2209
2210  // Enter the scope of this instantiation. We don't use
2211  // PushDeclContext because we don't have a scope.
2212  DeclContext *PreviousContext = CurContext;
2213  CurContext = Var->getDeclContext();
2214
2215  VarDecl *OldVar = Var;
2216  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2217                                          getTemplateInstantiationArgs(Var)));
2218  CurContext = PreviousContext;
2219
2220  if (Var) {
2221    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2222    assert(MSInfo && "Missing member specialization information?");
2223    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2224                                       MSInfo->getPointOfInstantiation());
2225    DeclGroupRef DG(Var);
2226    Consumer.HandleTopLevelDecl(DG);
2227  }
2228
2229  if (Recursive) {
2230    // Instantiate any pending implicit instantiations found during the
2231    // instantiation of this template.
2232    PerformPendingImplicitInstantiations();
2233
2234    // Restore the set of pending implicit instantiations.
2235    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2236  }
2237}
2238
2239void
2240Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2241                                 const CXXConstructorDecl *Tmpl,
2242                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2243
2244  llvm::SmallVector<MemInitTy*, 4> NewInits;
2245  bool AnyErrors = false;
2246
2247  // Instantiate all the initializers.
2248  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2249                                            InitsEnd = Tmpl->init_end();
2250       Inits != InitsEnd; ++Inits) {
2251    CXXBaseOrMemberInitializer *Init = *Inits;
2252
2253    SourceLocation LParenLoc, RParenLoc;
2254    ASTOwningVector<&ActionBase::DeleteExpr> NewArgs(*this);
2255    llvm::SmallVector<SourceLocation, 4> CommaLocs;
2256
2257    // Instantiate the initializer.
2258    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2259                               LParenLoc, CommaLocs, NewArgs, RParenLoc)) {
2260      AnyErrors = true;
2261      continue;
2262    }
2263
2264    MemInitResult NewInit;
2265    if (Init->isBaseInitializer()) {
2266      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2267                                            TemplateArgs,
2268                                            Init->getSourceLocation(),
2269                                            New->getDeclName());
2270      if (!BaseTInfo) {
2271        AnyErrors = true;
2272        New->setInvalidDecl();
2273        continue;
2274      }
2275
2276      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2277                                     (Expr **)NewArgs.data(),
2278                                     NewArgs.size(),
2279                                     Init->getLParenLoc(),
2280                                     Init->getRParenLoc(),
2281                                     New->getParent());
2282    } else if (Init->isMemberInitializer()) {
2283      FieldDecl *Member;
2284
2285      // Is this an anonymous union?
2286      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2287        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2288                                                      UnionInit, TemplateArgs));
2289      else
2290        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2291                                                      Init->getMember(),
2292                                                      TemplateArgs));
2293
2294      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2295                                       NewArgs.size(),
2296                                       Init->getSourceLocation(),
2297                                       Init->getLParenLoc(),
2298                                       Init->getRParenLoc());
2299    }
2300
2301    if (NewInit.isInvalid()) {
2302      AnyErrors = true;
2303      New->setInvalidDecl();
2304    } else {
2305      // FIXME: It would be nice if ASTOwningVector had a release function.
2306      NewArgs.take();
2307
2308      NewInits.push_back((MemInitTy *)NewInit.get());
2309    }
2310  }
2311
2312  // Assign all the initializers to the new constructor.
2313  ActOnMemInitializers(New,
2314                       /*FIXME: ColonLoc */
2315                       SourceLocation(),
2316                       NewInits.data(), NewInits.size(),
2317                       AnyErrors);
2318}
2319
2320// TODO: this could be templated if the various decl types used the
2321// same method name.
2322static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2323                              ClassTemplateDecl *Instance) {
2324  Pattern = Pattern->getCanonicalDecl();
2325
2326  do {
2327    Instance = Instance->getCanonicalDecl();
2328    if (Pattern == Instance) return true;
2329    Instance = Instance->getInstantiatedFromMemberTemplate();
2330  } while (Instance);
2331
2332  return false;
2333}
2334
2335static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2336                              FunctionTemplateDecl *Instance) {
2337  Pattern = Pattern->getCanonicalDecl();
2338
2339  do {
2340    Instance = Instance->getCanonicalDecl();
2341    if (Pattern == Instance) return true;
2342    Instance = Instance->getInstantiatedFromMemberTemplate();
2343  } while (Instance);
2344
2345  return false;
2346}
2347
2348static bool
2349isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2350                  ClassTemplatePartialSpecializationDecl *Instance) {
2351  Pattern
2352    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2353  do {
2354    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2355                                                Instance->getCanonicalDecl());
2356    if (Pattern == Instance)
2357      return true;
2358    Instance = Instance->getInstantiatedFromMember();
2359  } while (Instance);
2360
2361  return false;
2362}
2363
2364static bool isInstantiationOf(CXXRecordDecl *Pattern,
2365                              CXXRecordDecl *Instance) {
2366  Pattern = Pattern->getCanonicalDecl();
2367
2368  do {
2369    Instance = Instance->getCanonicalDecl();
2370    if (Pattern == Instance) return true;
2371    Instance = Instance->getInstantiatedFromMemberClass();
2372  } while (Instance);
2373
2374  return false;
2375}
2376
2377static bool isInstantiationOf(FunctionDecl *Pattern,
2378                              FunctionDecl *Instance) {
2379  Pattern = Pattern->getCanonicalDecl();
2380
2381  do {
2382    Instance = Instance->getCanonicalDecl();
2383    if (Pattern == Instance) return true;
2384    Instance = Instance->getInstantiatedFromMemberFunction();
2385  } while (Instance);
2386
2387  return false;
2388}
2389
2390static bool isInstantiationOf(EnumDecl *Pattern,
2391                              EnumDecl *Instance) {
2392  Pattern = Pattern->getCanonicalDecl();
2393
2394  do {
2395    Instance = Instance->getCanonicalDecl();
2396    if (Pattern == Instance) return true;
2397    Instance = Instance->getInstantiatedFromMemberEnum();
2398  } while (Instance);
2399
2400  return false;
2401}
2402
2403static bool isInstantiationOf(UsingShadowDecl *Pattern,
2404                              UsingShadowDecl *Instance,
2405                              ASTContext &C) {
2406  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2407}
2408
2409static bool isInstantiationOf(UsingDecl *Pattern,
2410                              UsingDecl *Instance,
2411                              ASTContext &C) {
2412  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2413}
2414
2415static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2416                              UsingDecl *Instance,
2417                              ASTContext &C) {
2418  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2419}
2420
2421static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2422                              UsingDecl *Instance,
2423                              ASTContext &C) {
2424  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2425}
2426
2427static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2428                                              VarDecl *Instance) {
2429  assert(Instance->isStaticDataMember());
2430
2431  Pattern = Pattern->getCanonicalDecl();
2432
2433  do {
2434    Instance = Instance->getCanonicalDecl();
2435    if (Pattern == Instance) return true;
2436    Instance = Instance->getInstantiatedFromStaticDataMember();
2437  } while (Instance);
2438
2439  return false;
2440}
2441
2442// Other is the prospective instantiation
2443// D is the prospective pattern
2444static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2445  if (D->getKind() != Other->getKind()) {
2446    if (UnresolvedUsingTypenameDecl *UUD
2447          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2448      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2449        return isInstantiationOf(UUD, UD, Ctx);
2450      }
2451    }
2452
2453    if (UnresolvedUsingValueDecl *UUD
2454          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2455      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2456        return isInstantiationOf(UUD, UD, Ctx);
2457      }
2458    }
2459
2460    return false;
2461  }
2462
2463  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2464    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2465
2466  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2467    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2468
2469  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2470    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2471
2472  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2473    if (Var->isStaticDataMember())
2474      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2475
2476  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2477    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2478
2479  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2480    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2481
2482  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2483        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2484    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2485                             PartialSpec);
2486
2487  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2488    if (!Field->getDeclName()) {
2489      // This is an unnamed field.
2490      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2491        cast<FieldDecl>(D);
2492    }
2493  }
2494
2495  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2496    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2497
2498  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2499    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2500
2501  return D->getDeclName() && isa<NamedDecl>(Other) &&
2502    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2503}
2504
2505template<typename ForwardIterator>
2506static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2507                                      NamedDecl *D,
2508                                      ForwardIterator first,
2509                                      ForwardIterator last) {
2510  for (; first != last; ++first)
2511    if (isInstantiationOf(Ctx, D, *first))
2512      return cast<NamedDecl>(*first);
2513
2514  return 0;
2515}
2516
2517/// \brief Finds the instantiation of the given declaration context
2518/// within the current instantiation.
2519///
2520/// \returns NULL if there was an error
2521DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2522                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2523  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2524    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2525    return cast_or_null<DeclContext>(ID);
2526  } else return DC;
2527}
2528
2529/// \brief Find the instantiation of the given declaration within the
2530/// current instantiation.
2531///
2532/// This routine is intended to be used when \p D is a declaration
2533/// referenced from within a template, that needs to mapped into the
2534/// corresponding declaration within an instantiation. For example,
2535/// given:
2536///
2537/// \code
2538/// template<typename T>
2539/// struct X {
2540///   enum Kind {
2541///     KnownValue = sizeof(T)
2542///   };
2543///
2544///   bool getKind() const { return KnownValue; }
2545/// };
2546///
2547/// template struct X<int>;
2548/// \endcode
2549///
2550/// In the instantiation of X<int>::getKind(), we need to map the
2551/// EnumConstantDecl for KnownValue (which refers to
2552/// X<T>::<Kind>::KnownValue) to its instantiation
2553/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2554/// this mapping from within the instantiation of X<int>.
2555NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2556                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2557  DeclContext *ParentDC = D->getDeclContext();
2558  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2559      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2560      (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext())) {
2561    // D is a local of some kind. Look into the map of local
2562    // declarations to their instantiations.
2563    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2564  }
2565
2566  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2567    if (!Record->isDependentContext())
2568      return D;
2569
2570    // If the RecordDecl is actually the injected-class-name or a
2571    // "templated" declaration for a class template, class template
2572    // partial specialization, or a member class of a class template,
2573    // substitute into the injected-class-name of the class template
2574    // or partial specialization to find the new DeclContext.
2575    QualType T;
2576    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2577
2578    if (ClassTemplate) {
2579      T = ClassTemplate->getInjectedClassNameSpecialization();
2580    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2581                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2582      ClassTemplate = PartialSpec->getSpecializedTemplate();
2583
2584      // If we call SubstType with an InjectedClassNameType here we
2585      // can end up in an infinite loop.
2586      T = Context.getTypeDeclType(Record);
2587      assert(isa<InjectedClassNameType>(T) &&
2588             "type of partial specialization is not an InjectedClassNameType");
2589      T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
2590    }
2591
2592    if (!T.isNull()) {
2593      // Substitute into the injected-class-name to get the type
2594      // corresponding to the instantiation we want, which may also be
2595      // the current instantiation (if we're in a template
2596      // definition). This substitution should never fail, since we
2597      // know we can instantiate the injected-class-name or we
2598      // wouldn't have gotten to the injected-class-name!
2599
2600      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2601      // extra instantiation in the common case?
2602      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2603      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2604
2605      if (!T->isDependentType()) {
2606        assert(T->isRecordType() && "Instantiation must produce a record type");
2607        return T->getAs<RecordType>()->getDecl();
2608      }
2609
2610      // We are performing "partial" template instantiation to create
2611      // the member declarations for the members of a class template
2612      // specialization. Therefore, D is actually referring to something
2613      // in the current instantiation. Look through the current
2614      // context, which contains actual instantiations, to find the
2615      // instantiation of the "current instantiation" that D refers
2616      // to.
2617      bool SawNonDependentContext = false;
2618      for (DeclContext *DC = CurContext; !DC->isFileContext();
2619           DC = DC->getParent()) {
2620        if (ClassTemplateSpecializationDecl *Spec
2621                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2622          if (isInstantiationOf(ClassTemplate,
2623                                Spec->getSpecializedTemplate()))
2624            return Spec;
2625
2626        if (!DC->isDependentContext())
2627          SawNonDependentContext = true;
2628      }
2629
2630      // We're performing "instantiation" of a member of the current
2631      // instantiation while we are type-checking the
2632      // definition. Compute the declaration context and return that.
2633      assert(!SawNonDependentContext &&
2634             "No dependent context while instantiating record");
2635      DeclContext *DC = computeDeclContext(T);
2636      assert(DC &&
2637             "Unable to find declaration for the current instantiation");
2638      return cast<CXXRecordDecl>(DC);
2639    }
2640
2641    // Fall through to deal with other dependent record types (e.g.,
2642    // anonymous unions in class templates).
2643  }
2644
2645  if (!ParentDC->isDependentContext())
2646    return D;
2647
2648  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2649  if (!ParentDC)
2650    return 0;
2651
2652  if (ParentDC != D->getDeclContext()) {
2653    // We performed some kind of instantiation in the parent context,
2654    // so now we need to look into the instantiated parent context to
2655    // find the instantiation of the declaration D.
2656
2657    // If our context used to be dependent, we may need to instantiate
2658    // it before performing lookup into that context.
2659    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2660      if (!Spec->isDependentContext()) {
2661        QualType T = Context.getTypeDeclType(Spec);
2662        const RecordType *Tag = T->getAs<RecordType>();
2663        assert(Tag && "type of non-dependent record is not a RecordType");
2664        if (!Tag->isBeingDefined() &&
2665            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2666          return 0;
2667      }
2668    }
2669
2670    NamedDecl *Result = 0;
2671    if (D->getDeclName()) {
2672      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2673      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2674    } else {
2675      // Since we don't have a name for the entity we're looking for,
2676      // our only option is to walk through all of the declarations to
2677      // find that name. This will occur in a few cases:
2678      //
2679      //   - anonymous struct/union within a template
2680      //   - unnamed class/struct/union/enum within a template
2681      //
2682      // FIXME: Find a better way to find these instantiations!
2683      Result = findInstantiationOf(Context, D,
2684                                   ParentDC->decls_begin(),
2685                                   ParentDC->decls_end());
2686    }
2687
2688    // UsingShadowDecls can instantiate to nothing because of using hiding.
2689    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2690            cast<Decl>(ParentDC)->isInvalidDecl())
2691           && "Unable to find instantiation of declaration!");
2692
2693    D = Result;
2694  }
2695
2696  return D;
2697}
2698
2699/// \brief Performs template instantiation for all implicit template
2700/// instantiations we have seen until this point.
2701void Sema::PerformPendingImplicitInstantiations(bool LocalOnly) {
2702  while (!PendingLocalImplicitInstantiations.empty() ||
2703         (!LocalOnly && !PendingImplicitInstantiations.empty())) {
2704    PendingImplicitInstantiation Inst;
2705
2706    if (PendingLocalImplicitInstantiations.empty()) {
2707      Inst = PendingImplicitInstantiations.front();
2708      PendingImplicitInstantiations.pop_front();
2709    } else {
2710      Inst = PendingLocalImplicitInstantiations.front();
2711      PendingLocalImplicitInstantiations.pop_front();
2712    }
2713
2714    // Instantiate function definitions
2715    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2716      PrettyStackTraceActionsDecl CrashInfo(Function,
2717                                            Function->getLocation(), *this,
2718                                            Context.getSourceManager(),
2719                                           "instantiating function definition");
2720
2721      InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true);
2722      continue;
2723    }
2724
2725    // Instantiate static data member definitions.
2726    VarDecl *Var = cast<VarDecl>(Inst.first);
2727    assert(Var->isStaticDataMember() && "Not a static data member?");
2728
2729    // Don't try to instantiate declarations if the most recent redeclaration
2730    // is invalid.
2731    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2732      continue;
2733
2734    // Check if the most recent declaration has changed the specialization kind
2735    // and removed the need for implicit instantiation.
2736    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2737    case TSK_Undeclared:
2738      assert(false && "Cannot instantitiate an undeclared specialization.");
2739    case TSK_ExplicitInstantiationDeclaration:
2740    case TSK_ExplicitInstantiationDefinition:
2741    case TSK_ExplicitSpecialization:
2742      continue;  // No longer need implicit instantiation.
2743    case TSK_ImplicitInstantiation:
2744      break;
2745    }
2746
2747    PrettyStackTraceActionsDecl CrashInfo(Var, Var->getLocation(), *this,
2748                                          Context.getSourceManager(),
2749                                          "instantiating static data member "
2750                                          "definition");
2751
2752    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true);
2753  }
2754}
2755
2756void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2757                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2758  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2759         E = Pattern->ddiag_end(); I != E; ++I) {
2760    DependentDiagnostic *DD = *I;
2761
2762    switch (DD->getKind()) {
2763    case DependentDiagnostic::Access:
2764      HandleDependentAccessCheck(*DD, TemplateArgs);
2765      break;
2766    }
2767  }
2768}
2769