SemaTemplateInstantiateDecl.cpp revision 2d562147b4d12f5ca3f1d3265c4703244182603b 
1//===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//===----------------------------------------------------------------------===/
8//
9//  This file implements C++ template instantiation for declarations.
10//
11//===----------------------------------------------------------------------===/
12#include "Sema.h"
13#include "Lookup.h"
14#include "clang/AST/ASTConsumer.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/DeclTemplate.h"
17#include "clang/AST/DeclVisitor.h"
18#include "clang/AST/DependentDiagnostic.h"
19#include "clang/AST/Expr.h"
20#include "clang/AST/ExprCXX.h"
21#include "clang/AST/TypeLoc.h"
22#include "clang/Basic/PrettyStackTrace.h"
23#include "clang/Lex/Preprocessor.h"
24
25using namespace clang;
26
27namespace {
28  class TemplateDeclInstantiator
29    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
30    Sema &SemaRef;
31    DeclContext *Owner;
32    const MultiLevelTemplateArgumentList &TemplateArgs;
33
34    void InstantiateAttrs(Decl *Tmpl, Decl *New);
35
36  public:
37    typedef Sema::OwningExprResult OwningExprResult;
38
39    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
40                             const MultiLevelTemplateArgumentList &TemplateArgs)
41      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
42
43    // FIXME: Once we get closer to completion, replace these manually-written
44    // declarations with automatically-generated ones from
45    // clang/AST/DeclNodes.inc.
46    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
47    Decl *VisitNamespaceDecl(NamespaceDecl *D);
48    Decl *VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
49    Decl *VisitTypedefDecl(TypedefDecl *D);
50    Decl *VisitVarDecl(VarDecl *D);
51    Decl *VisitAccessSpecDecl(AccessSpecDecl *D);
52    Decl *VisitFieldDecl(FieldDecl *D);
53    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
54    Decl *VisitEnumDecl(EnumDecl *D);
55    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
56    Decl *VisitFriendDecl(FriendDecl *D);
57    Decl *VisitFunctionDecl(FunctionDecl *D,
58                            TemplateParameterList *TemplateParams = 0);
59    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
60    Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
61                             TemplateParameterList *TemplateParams = 0);
62    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
63    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
64    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
65    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
66    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
67    Decl *VisitClassTemplatePartialSpecializationDecl(
68                                    ClassTemplatePartialSpecializationDecl *D);
69    Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
70    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
71    Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
72    Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
73    Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
74    Decl *VisitUsingDecl(UsingDecl *D);
75    Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
76    Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
77    Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
78
79    // Base case. FIXME: Remove once we can instantiate everything.
80    Decl *VisitDecl(Decl *D) {
81      unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
82                                                            Diagnostic::Error,
83                                                   "cannot instantiate %0 yet");
84      SemaRef.Diag(D->getLocation(), DiagID)
85        << D->getDeclKindName();
86
87      return 0;
88    }
89
90    const LangOptions &getLangOptions() {
91      return SemaRef.getLangOptions();
92    }
93
94    // Helper functions for instantiating methods.
95    TypeSourceInfo *SubstFunctionType(FunctionDecl *D,
96                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
97    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
98    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
99
100    TemplateParameterList *
101      SubstTemplateParams(TemplateParameterList *List);
102
103    bool SubstQualifier(const DeclaratorDecl *OldDecl,
104                        DeclaratorDecl *NewDecl);
105    bool SubstQualifier(const TagDecl *OldDecl,
106                        TagDecl *NewDecl);
107
108    bool InstantiateClassTemplatePartialSpecialization(
109                                              ClassTemplateDecl *ClassTemplate,
110                           ClassTemplatePartialSpecializationDecl *PartialSpec);
111  };
112}
113
114bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
115                                              DeclaratorDecl *NewDecl) {
116  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
117  if (!OldQual) return false;
118
119  SourceRange QualRange = OldDecl->getQualifierRange();
120
121  NestedNameSpecifier *NewQual
122    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
123  if (!NewQual)
124    return true;
125
126  NewDecl->setQualifierInfo(NewQual, QualRange);
127  return false;
128}
129
130bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
131                                              TagDecl *NewDecl) {
132  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
133  if (!OldQual) return false;
134
135  SourceRange QualRange = OldDecl->getQualifierRange();
136
137  NestedNameSpecifier *NewQual
138    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
139  if (!NewQual)
140    return true;
141
142  NewDecl->setQualifierInfo(NewQual, QualRange);
143  return false;
144}
145
146// FIXME: Is this still too simple?
147void TemplateDeclInstantiator::InstantiateAttrs(Decl *Tmpl, Decl *New) {
148  for (const Attr *TmplAttr = Tmpl->getAttrs(); TmplAttr;
149       TmplAttr = TmplAttr->getNext()) {
150    // FIXME: This should be generalized to more than just the AlignedAttr.
151    if (const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr)) {
152      if (Aligned->isDependent()) {
153        // The alignment expression is not potentially evaluated.
154        EnterExpressionEvaluationContext Unevaluated(SemaRef,
155                                                     Action::Unevaluated);
156
157        OwningExprResult Result = SemaRef.SubstExpr(Aligned->getAlignmentExpr(),
158                                                    TemplateArgs);
159        if (!Result.isInvalid())
160          // FIXME: Is this the correct source location?
161          SemaRef.AddAlignedAttr(Aligned->getAlignmentExpr()->getExprLoc(),
162                                 New, Result.takeAs<Expr>());
163        continue;
164      }
165    }
166
167    // FIXME: Is cloning correct for all attributes?
168    Attr *NewAttr = TmplAttr->clone(SemaRef.Context);
169    New->addAttr(NewAttr);
170  }
171}
172
173Decl *
174TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
175  assert(false && "Translation units cannot be instantiated");
176  return D;
177}
178
179Decl *
180TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
181  assert(false && "Namespaces cannot be instantiated");
182  return D;
183}
184
185Decl *
186TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
187  NamespaceAliasDecl *Inst
188    = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
189                                 D->getNamespaceLoc(),
190                                 D->getAliasLoc(),
191                                 D->getNamespace()->getIdentifier(),
192                                 D->getQualifierRange(),
193                                 D->getQualifier(),
194                                 D->getTargetNameLoc(),
195                                 D->getNamespace());
196  Owner->addDecl(Inst);
197  return Inst;
198}
199
200Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
201  bool Invalid = false;
202  TypeSourceInfo *DI = D->getTypeSourceInfo();
203  if (DI->getType()->isDependentType() ||
204      DI->getType()->isVariablyModifiedType()) {
205    DI = SemaRef.SubstType(DI, TemplateArgs,
206                           D->getLocation(), D->getDeclName());
207    if (!DI) {
208      Invalid = true;
209      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
210    }
211  } else {
212    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
213  }
214
215  // Create the new typedef
216  TypedefDecl *Typedef
217    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
218                          D->getIdentifier(), DI);
219  if (Invalid)
220    Typedef->setInvalidDecl();
221
222  if (const TagType *TT = DI->getType()->getAs<TagType>()) {
223    TagDecl *TD = TT->getDecl();
224
225    // If the TagDecl that the TypedefDecl points to is an anonymous decl
226    // keep track of the TypedefDecl.
227    if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl())
228      TD->setTypedefForAnonDecl(Typedef);
229  }
230
231  if (TypedefDecl *Prev = D->getPreviousDeclaration()) {
232    NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
233                                                       TemplateArgs);
234    Typedef->setPreviousDeclaration(cast<TypedefDecl>(InstPrev));
235  }
236
237  InstantiateAttrs(D, Typedef);
238
239  Typedef->setAccess(D->getAccess());
240  Owner->addDecl(Typedef);
241
242  return Typedef;
243}
244
245/// \brief Instantiate the arguments provided as part of initialization.
246///
247/// \returns true if an error occurred, false otherwise.
248static bool InstantiateInitializationArguments(Sema &SemaRef,
249                                               Expr **Args, unsigned NumArgs,
250                           const MultiLevelTemplateArgumentList &TemplateArgs,
251                         llvm::SmallVectorImpl<SourceLocation> &FakeCommaLocs,
252                           ASTOwningVector<&ActionBase::DeleteExpr> &InitArgs) {
253  for (unsigned I = 0; I != NumArgs; ++I) {
254    // When we hit the first defaulted argument, break out of the loop:
255    // we don't pass those default arguments on.
256    if (Args[I]->isDefaultArgument())
257      break;
258
259    Sema::OwningExprResult Arg = SemaRef.SubstExpr(Args[I], TemplateArgs);
260    if (Arg.isInvalid())
261      return true;
262
263    Expr *ArgExpr = (Expr *)Arg.get();
264    InitArgs.push_back(Arg.release());
265
266    // FIXME: We're faking all of the comma locations. Do we need them?
267    FakeCommaLocs.push_back(
268                          SemaRef.PP.getLocForEndOfToken(ArgExpr->getLocEnd()));
269  }
270
271  return false;
272}
273
274/// \brief Instantiate an initializer, breaking it into separate
275/// initialization arguments.
276///
277/// \param S The semantic analysis object.
278///
279/// \param Init The initializer to instantiate.
280///
281/// \param TemplateArgs Template arguments to be substituted into the
282/// initializer.
283///
284/// \param NewArgs Will be filled in with the instantiation arguments.
285///
286/// \returns true if an error occurred, false otherwise
287static bool InstantiateInitializer(Sema &S, Expr *Init,
288                            const MultiLevelTemplateArgumentList &TemplateArgs,
289                                   SourceLocation &LParenLoc,
290                               llvm::SmallVector<SourceLocation, 4> &CommaLocs,
291                             ASTOwningVector<&ActionBase::DeleteExpr> &NewArgs,
292                                   SourceLocation &RParenLoc) {
293  NewArgs.clear();
294  LParenLoc = SourceLocation();
295  RParenLoc = SourceLocation();
296
297  if (!Init)
298    return false;
299
300  if (CXXExprWithTemporaries *ExprTemp = dyn_cast<CXXExprWithTemporaries>(Init))
301    Init = ExprTemp->getSubExpr();
302
303  while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init))
304    Init = Binder->getSubExpr();
305
306  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
307    Init = ICE->getSubExprAsWritten();
308
309  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
310    LParenLoc = ParenList->getLParenLoc();
311    RParenLoc = ParenList->getRParenLoc();
312    return InstantiateInitializationArguments(S, ParenList->getExprs(),
313                                              ParenList->getNumExprs(),
314                                              TemplateArgs, CommaLocs,
315                                              NewArgs);
316  }
317
318  if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) {
319    if (!isa<CXXTemporaryObjectExpr>(Construct)) {
320      if (InstantiateInitializationArguments(S,
321                                             Construct->getArgs(),
322                                             Construct->getNumArgs(),
323                                             TemplateArgs,
324                                             CommaLocs, NewArgs))
325        return true;
326
327      // FIXME: Fake locations!
328      LParenLoc = S.PP.getLocForEndOfToken(Init->getLocStart());
329      RParenLoc = CommaLocs.empty()? LParenLoc : CommaLocs.back();
330      return false;
331    }
332  }
333
334  Sema::OwningExprResult Result = S.SubstExpr(Init, TemplateArgs);
335  if (Result.isInvalid())
336    return true;
337
338  NewArgs.push_back(Result.takeAs<Expr>());
339  return false;
340}
341
342Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
343  // If this is the variable for an anonymous struct or union,
344  // instantiate the anonymous struct/union type first.
345  if (const RecordType *RecordTy = D->getType()->getAs<RecordType>())
346    if (RecordTy->getDecl()->isAnonymousStructOrUnion())
347      if (!VisitCXXRecordDecl(cast<CXXRecordDecl>(RecordTy->getDecl())))
348        return 0;
349
350  // Do substitution on the type of the declaration
351  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
352                                         TemplateArgs,
353                                         D->getTypeSpecStartLoc(),
354                                         D->getDeclName());
355  if (!DI)
356    return 0;
357
358  // Build the instantiated declaration
359  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
360                                 D->getLocation(), D->getIdentifier(),
361                                 DI->getType(), DI,
362                                 D->getStorageClass(),
363                                 D->getStorageClassAsWritten());
364  Var->setThreadSpecified(D->isThreadSpecified());
365  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
366  Var->setDeclaredInCondition(D->isDeclaredInCondition());
367
368  // Substitute the nested name specifier, if any.
369  if (SubstQualifier(D, Var))
370    return 0;
371
372  // If we are instantiating a static data member defined
373  // out-of-line, the instantiation will have the same lexical
374  // context (which will be a namespace scope) as the template.
375  if (D->isOutOfLine())
376    Var->setLexicalDeclContext(D->getLexicalDeclContext());
377
378  Var->setAccess(D->getAccess());
379
380  if (!D->isStaticDataMember())
381    Var->setUsed(D->isUsed(false));
382
383  // FIXME: In theory, we could have a previous declaration for variables that
384  // are not static data members.
385  bool Redeclaration = false;
386  // FIXME: having to fake up a LookupResult is dumb.
387  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
388                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
389  if (D->isStaticDataMember())
390    SemaRef.LookupQualifiedName(Previous, Owner, false);
391  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
392
393  if (D->isOutOfLine()) {
394    if (!D->isStaticDataMember())
395      D->getLexicalDeclContext()->addDecl(Var);
396    Owner->makeDeclVisibleInContext(Var);
397  } else {
398    Owner->addDecl(Var);
399
400    if (Owner->isFunctionOrMethod())
401      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Var);
402  }
403
404  // Link instantiations of static data members back to the template from
405  // which they were instantiated.
406  if (Var->isStaticDataMember())
407    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
408                                                     TSK_ImplicitInstantiation);
409
410  if (Var->getAnyInitializer()) {
411    // We already have an initializer in the class.
412  } else if (D->getInit()) {
413    if (Var->isStaticDataMember() && !D->isOutOfLine())
414      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
415    else
416      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
417
418    // Instantiate the initializer.
419    SourceLocation LParenLoc, RParenLoc;
420    llvm::SmallVector<SourceLocation, 4> CommaLocs;
421    ASTOwningVector<&ActionBase::DeleteExpr> InitArgs(SemaRef);
422    if (!InstantiateInitializer(SemaRef, D->getInit(), TemplateArgs, LParenLoc,
423                                CommaLocs, InitArgs, RParenLoc)) {
424      // Attach the initializer to the declaration.
425      if (D->hasCXXDirectInitializer()) {
426        // Add the direct initializer to the declaration.
427        SemaRef.AddCXXDirectInitializerToDecl(Sema::DeclPtrTy::make(Var),
428                                              LParenLoc,
429                                              move_arg(InitArgs),
430                                              CommaLocs.data(),
431                                              RParenLoc);
432      } else if (InitArgs.size() == 1) {
433        Expr *Init = (Expr*)(InitArgs.take()[0]);
434        SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var),
435                                     SemaRef.Owned(Init),
436                                     false);
437      } else {
438        assert(InitArgs.size() == 0);
439        SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
440      }
441    } else {
442      // FIXME: Not too happy about invalidating the declaration
443      // because of a bogus initializer.
444      Var->setInvalidDecl();
445    }
446
447    SemaRef.PopExpressionEvaluationContext();
448  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
449    SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
450
451  // Diagnose unused local variables.
452  if (!Var->isInvalidDecl() && Owner->isFunctionOrMethod() && !Var->isUsed())
453    SemaRef.DiagnoseUnusedDecl(Var);
454
455  return Var;
456}
457
458Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
459  AccessSpecDecl* AD
460    = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
461                             D->getAccessSpecifierLoc(), D->getColonLoc());
462  Owner->addHiddenDecl(AD);
463  return AD;
464}
465
466Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
467  bool Invalid = false;
468  TypeSourceInfo *DI = D->getTypeSourceInfo();
469  if (DI->getType()->isDependentType() ||
470      DI->getType()->isVariablyModifiedType())  {
471    DI = SemaRef.SubstType(DI, TemplateArgs,
472                           D->getLocation(), D->getDeclName());
473    if (!DI) {
474      DI = D->getTypeSourceInfo();
475      Invalid = true;
476    } else if (DI->getType()->isFunctionType()) {
477      // C++ [temp.arg.type]p3:
478      //   If a declaration acquires a function type through a type
479      //   dependent on a template-parameter and this causes a
480      //   declaration that does not use the syntactic form of a
481      //   function declarator to have function type, the program is
482      //   ill-formed.
483      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
484        << DI->getType();
485      Invalid = true;
486    }
487  } else {
488    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
489  }
490
491  Expr *BitWidth = D->getBitWidth();
492  if (Invalid)
493    BitWidth = 0;
494  else if (BitWidth) {
495    // The bit-width expression is not potentially evaluated.
496    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
497
498    OwningExprResult InstantiatedBitWidth
499      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
500    if (InstantiatedBitWidth.isInvalid()) {
501      Invalid = true;
502      BitWidth = 0;
503    } else
504      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
505  }
506
507  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
508                                            DI->getType(), DI,
509                                            cast<RecordDecl>(Owner),
510                                            D->getLocation(),
511                                            D->isMutable(),
512                                            BitWidth,
513                                            D->getTypeSpecStartLoc(),
514                                            D->getAccess(),
515                                            0);
516  if (!Field) {
517    cast<Decl>(Owner)->setInvalidDecl();
518    return 0;
519  }
520
521  InstantiateAttrs(D, Field);
522
523  if (Invalid)
524    Field->setInvalidDecl();
525
526  if (!Field->getDeclName()) {
527    // Keep track of where this decl came from.
528    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
529  }
530  if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
531    if (Parent->isAnonymousStructOrUnion() &&
532        Parent->getLookupContext()->isFunctionOrMethod())
533      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
534  }
535
536  Field->setImplicit(D->isImplicit());
537  Field->setAccess(D->getAccess());
538  Owner->addDecl(Field);
539
540  return Field;
541}
542
543Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
544  // Handle friend type expressions by simply substituting template
545  // parameters into the pattern type and checking the result.
546  if (TypeSourceInfo *Ty = D->getFriendType()) {
547    TypeSourceInfo *InstTy =
548      SemaRef.SubstType(Ty, TemplateArgs,
549                        D->getLocation(), DeclarationName());
550    if (!InstTy)
551      return 0;
552
553    FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getFriendLoc(), InstTy);
554    if (!FD)
555      return 0;
556
557    FD->setAccess(AS_public);
558    Owner->addDecl(FD);
559    return FD;
560  }
561
562  NamedDecl *ND = D->getFriendDecl();
563  assert(ND && "friend decl must be a decl or a type!");
564
565  // All of the Visit implementations for the various potential friend
566  // declarations have to be carefully written to work for friend
567  // objects, with the most important detail being that the target
568  // decl should almost certainly not be placed in Owner.
569  Decl *NewND = Visit(ND);
570  if (!NewND) return 0;
571
572  FriendDecl *FD =
573    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
574                       cast<NamedDecl>(NewND), D->getFriendLoc());
575  FD->setAccess(AS_public);
576  Owner->addDecl(FD);
577  return FD;
578}
579
580Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
581  Expr *AssertExpr = D->getAssertExpr();
582
583  // The expression in a static assertion is not potentially evaluated.
584  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
585
586  OwningExprResult InstantiatedAssertExpr
587    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
588  if (InstantiatedAssertExpr.isInvalid())
589    return 0;
590
591  OwningExprResult Message(SemaRef, D->getMessage());
592  D->getMessage()->Retain();
593  Decl *StaticAssert
594    = SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
595                                           move(InstantiatedAssertExpr),
596                                           move(Message)).getAs<Decl>();
597  return StaticAssert;
598}
599
600Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
601  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
602                                    D->getLocation(), D->getIdentifier(),
603                                    D->getTagKeywordLoc(),
604                                    /*PrevDecl=*/0);
605  Enum->setInstantiationOfMemberEnum(D);
606  Enum->setAccess(D->getAccess());
607  if (SubstQualifier(D, Enum)) return 0;
608  Owner->addDecl(Enum);
609  Enum->startDefinition();
610
611  if (D->getDeclContext()->isFunctionOrMethod())
612    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
613
614  llvm::SmallVector<Sema::DeclPtrTy, 4> Enumerators;
615
616  EnumConstantDecl *LastEnumConst = 0;
617  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
618         ECEnd = D->enumerator_end();
619       EC != ECEnd; ++EC) {
620    // The specified value for the enumerator.
621    OwningExprResult Value = SemaRef.Owned((Expr *)0);
622    if (Expr *UninstValue = EC->getInitExpr()) {
623      // The enumerator's value expression is not potentially evaluated.
624      EnterExpressionEvaluationContext Unevaluated(SemaRef,
625                                                   Action::Unevaluated);
626
627      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
628    }
629
630    // Drop the initial value and continue.
631    bool isInvalid = false;
632    if (Value.isInvalid()) {
633      Value = SemaRef.Owned((Expr *)0);
634      isInvalid = true;
635    }
636
637    EnumConstantDecl *EnumConst
638      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
639                                  EC->getLocation(), EC->getIdentifier(),
640                                  move(Value));
641
642    if (isInvalid) {
643      if (EnumConst)
644        EnumConst->setInvalidDecl();
645      Enum->setInvalidDecl();
646    }
647
648    if (EnumConst) {
649      EnumConst->setAccess(Enum->getAccess());
650      Enum->addDecl(EnumConst);
651      Enumerators.push_back(Sema::DeclPtrTy::make(EnumConst));
652      LastEnumConst = EnumConst;
653
654      if (D->getDeclContext()->isFunctionOrMethod()) {
655        // If the enumeration is within a function or method, record the enum
656        // constant as a local.
657        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
658      }
659    }
660  }
661
662  // FIXME: Fixup LBraceLoc and RBraceLoc
663  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
664  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
665                        Sema::DeclPtrTy::make(Enum),
666                        &Enumerators[0], Enumerators.size(),
667                        0, 0);
668
669  return Enum;
670}
671
672Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
673  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
674  return 0;
675}
676
677Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
678  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
679
680  // Create a local instantiation scope for this class template, which
681  // will contain the instantiations of the template parameters.
682  Sema::LocalInstantiationScope Scope(SemaRef);
683  TemplateParameterList *TempParams = D->getTemplateParameters();
684  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
685  if (!InstParams)
686    return NULL;
687
688  CXXRecordDecl *Pattern = D->getTemplatedDecl();
689
690  // Instantiate the qualifier.  We have to do this first in case
691  // we're a friend declaration, because if we are then we need to put
692  // the new declaration in the appropriate context.
693  NestedNameSpecifier *Qualifier = Pattern->getQualifier();
694  if (Qualifier) {
695    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
696                                                 Pattern->getQualifierRange(),
697                                                 TemplateArgs);
698    if (!Qualifier) return 0;
699  }
700
701  CXXRecordDecl *PrevDecl = 0;
702  ClassTemplateDecl *PrevClassTemplate = 0;
703
704  // If this isn't a friend, then it's a member template, in which
705  // case we just want to build the instantiation in the
706  // specialization.  If it is a friend, we want to build it in
707  // the appropriate context.
708  DeclContext *DC = Owner;
709  if (isFriend) {
710    if (Qualifier) {
711      CXXScopeSpec SS;
712      SS.setScopeRep(Qualifier);
713      SS.setRange(Pattern->getQualifierRange());
714      DC = SemaRef.computeDeclContext(SS);
715      if (!DC) return 0;
716    } else {
717      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
718                                           Pattern->getDeclContext(),
719                                           TemplateArgs);
720    }
721
722    // Look for a previous declaration of the template in the owning
723    // context.
724    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
725                   Sema::LookupOrdinaryName, Sema::ForRedeclaration);
726    SemaRef.LookupQualifiedName(R, DC);
727
728    if (R.isSingleResult()) {
729      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
730      if (PrevClassTemplate)
731        PrevDecl = PrevClassTemplate->getTemplatedDecl();
732    }
733
734    if (!PrevClassTemplate && Qualifier) {
735      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
736        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
737        << Pattern->getQualifierRange();
738      return 0;
739    }
740
741    bool AdoptedPreviousTemplateParams = false;
742    if (PrevClassTemplate) {
743      bool Complain = true;
744
745      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
746      // template for struct std::tr1::__detail::_Map_base, where the
747      // template parameters of the friend declaration don't match the
748      // template parameters of the original declaration. In this one
749      // case, we don't complain about the ill-formed friend
750      // declaration.
751      if (isFriend && Pattern->getIdentifier() &&
752          Pattern->getIdentifier()->isStr("_Map_base") &&
753          DC->isNamespace() &&
754          cast<NamespaceDecl>(DC)->getIdentifier() &&
755          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
756        DeclContext *DCParent = DC->getParent();
757        if (DCParent->isNamespace() &&
758            cast<NamespaceDecl>(DCParent)->getIdentifier() &&
759            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
760          DeclContext *DCParent2 = DCParent->getParent();
761          if (DCParent2->isNamespace() &&
762              cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
763              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
764              DCParent2->getParent()->isTranslationUnit())
765            Complain = false;
766        }
767      }
768
769      TemplateParameterList *PrevParams
770        = PrevClassTemplate->getTemplateParameters();
771
772      // Make sure the parameter lists match.
773      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
774                                                  Complain,
775                                                  Sema::TPL_TemplateMatch)) {
776        if (Complain)
777          return 0;
778
779        AdoptedPreviousTemplateParams = true;
780        InstParams = PrevParams;
781      }
782
783      // Do some additional validation, then merge default arguments
784      // from the existing declarations.
785      if (!AdoptedPreviousTemplateParams &&
786          SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
787                                             Sema::TPC_ClassTemplate))
788        return 0;
789    }
790  }
791
792  CXXRecordDecl *RecordInst
793    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
794                            Pattern->getLocation(), Pattern->getIdentifier(),
795                            Pattern->getTagKeywordLoc(), PrevDecl,
796                            /*DelayTypeCreation=*/true);
797
798  if (Qualifier)
799    RecordInst->setQualifierInfo(Qualifier, Pattern->getQualifierRange());
800
801  ClassTemplateDecl *Inst
802    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
803                                D->getIdentifier(), InstParams, RecordInst,
804                                PrevClassTemplate);
805  RecordInst->setDescribedClassTemplate(Inst);
806
807  if (isFriend) {
808    if (PrevClassTemplate)
809      Inst->setAccess(PrevClassTemplate->getAccess());
810    else
811      Inst->setAccess(D->getAccess());
812
813    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
814    // TODO: do we want to track the instantiation progeny of this
815    // friend target decl?
816  } else {
817    Inst->setAccess(D->getAccess());
818    Inst->setInstantiatedFromMemberTemplate(D);
819  }
820
821  // Trigger creation of the type for the instantiation.
822  SemaRef.Context.getInjectedClassNameType(RecordInst,
823                                    Inst->getInjectedClassNameSpecialization());
824
825  // Finish handling of friends.
826  if (isFriend) {
827    DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
828    return Inst;
829  }
830
831  Owner->addDecl(Inst);
832
833  // Instantiate all of the partial specializations of this member class
834  // template.
835  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
836  D->getPartialSpecializations(PartialSpecs);
837  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
838    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
839
840  return Inst;
841}
842
843Decl *
844TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
845                                   ClassTemplatePartialSpecializationDecl *D) {
846  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
847
848  // Lookup the already-instantiated declaration in the instantiation
849  // of the class template and return that.
850  DeclContext::lookup_result Found
851    = Owner->lookup(ClassTemplate->getDeclName());
852  if (Found.first == Found.second)
853    return 0;
854
855  ClassTemplateDecl *InstClassTemplate
856    = dyn_cast<ClassTemplateDecl>(*Found.first);
857  if (!InstClassTemplate)
858    return 0;
859
860  Decl *DCanon = D->getCanonicalDecl();
861  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
862            P = InstClassTemplate->getPartialSpecializations().begin(),
863         PEnd = InstClassTemplate->getPartialSpecializations().end();
864       P != PEnd; ++P) {
865    if (P->getInstantiatedFromMember()->getCanonicalDecl() == DCanon)
866      return &*P;
867  }
868
869  return 0;
870}
871
872Decl *
873TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
874  // Create a local instantiation scope for this function template, which
875  // will contain the instantiations of the template parameters and then get
876  // merged with the local instantiation scope for the function template
877  // itself.
878  Sema::LocalInstantiationScope Scope(SemaRef);
879
880  TemplateParameterList *TempParams = D->getTemplateParameters();
881  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
882  if (!InstParams)
883    return NULL;
884
885  FunctionDecl *Instantiated = 0;
886  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
887    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
888                                                                 InstParams));
889  else
890    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
891                                                          D->getTemplatedDecl(),
892                                                                InstParams));
893
894  if (!Instantiated)
895    return 0;
896
897  Instantiated->setAccess(D->getAccess());
898
899  // Link the instantiated function template declaration to the function
900  // template from which it was instantiated.
901  FunctionTemplateDecl *InstTemplate
902    = Instantiated->getDescribedFunctionTemplate();
903  InstTemplate->setAccess(D->getAccess());
904  assert(InstTemplate &&
905         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
906
907  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
908
909  // Link the instantiation back to the pattern *unless* this is a
910  // non-definition friend declaration.
911  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
912      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
913    InstTemplate->setInstantiatedFromMemberTemplate(D);
914
915  // Make declarations visible in the appropriate context.
916  if (!isFriend)
917    Owner->addDecl(InstTemplate);
918
919  return InstTemplate;
920}
921
922Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
923  CXXRecordDecl *PrevDecl = 0;
924  if (D->isInjectedClassName())
925    PrevDecl = cast<CXXRecordDecl>(Owner);
926  else if (D->getPreviousDeclaration()) {
927    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
928                                                   D->getPreviousDeclaration(),
929                                                   TemplateArgs);
930    if (!Prev) return 0;
931    PrevDecl = cast<CXXRecordDecl>(Prev);
932  }
933
934  CXXRecordDecl *Record
935    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
936                            D->getLocation(), D->getIdentifier(),
937                            D->getTagKeywordLoc(), PrevDecl);
938
939  // Substitute the nested name specifier, if any.
940  if (SubstQualifier(D, Record))
941    return 0;
942
943  Record->setImplicit(D->isImplicit());
944  // FIXME: Check against AS_none is an ugly hack to work around the issue that
945  // the tag decls introduced by friend class declarations don't have an access
946  // specifier. Remove once this area of the code gets sorted out.
947  if (D->getAccess() != AS_none)
948    Record->setAccess(D->getAccess());
949  if (!D->isInjectedClassName())
950    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
951
952  // If the original function was part of a friend declaration,
953  // inherit its namespace state.
954  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
955    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
956
957  // Make sure that anonymous structs and unions are recorded.
958  if (D->isAnonymousStructOrUnion()) {
959    Record->setAnonymousStructOrUnion(true);
960    if (Record->getDeclContext()->getLookupContext()->isFunctionOrMethod())
961      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
962  }
963
964  Owner->addDecl(Record);
965  return Record;
966}
967
968/// Normal class members are of more specific types and therefore
969/// don't make it here.  This function serves two purposes:
970///   1) instantiating function templates
971///   2) substituting friend declarations
972/// FIXME: preserve function definitions in case #2
973Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
974                                       TemplateParameterList *TemplateParams) {
975  // Check whether there is already a function template specialization for
976  // this declaration.
977  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
978  void *InsertPos = 0;
979  if (FunctionTemplate && !TemplateParams) {
980    llvm::FoldingSetNodeID ID;
981    std::pair<const TemplateArgument *, unsigned> Innermost
982      = TemplateArgs.getInnermost();
983    FunctionTemplateSpecializationInfo::Profile(ID, Innermost.first,
984                                                Innermost.second,
985                                                SemaRef.Context);
986
987    FunctionTemplateSpecializationInfo *Info
988      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
989                                                                   InsertPos);
990
991    // If we already have a function template specialization, return it.
992    if (Info)
993      return Info->Function;
994  }
995
996  bool isFriend;
997  if (FunctionTemplate)
998    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
999  else
1000    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1001
1002  bool MergeWithParentScope = (TemplateParams != 0) ||
1003    Owner->isFunctionOrMethod() ||
1004    !(isa<Decl>(Owner) &&
1005      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1006  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1007
1008  llvm::SmallVector<ParmVarDecl *, 4> Params;
1009  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1010  TInfo = SubstFunctionType(D, Params);
1011  if (!TInfo)
1012    return 0;
1013  QualType T = TInfo->getType();
1014
1015  NestedNameSpecifier *Qualifier = D->getQualifier();
1016  if (Qualifier) {
1017    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1018                                                 D->getQualifierRange(),
1019                                                 TemplateArgs);
1020    if (!Qualifier) return 0;
1021  }
1022
1023  // If we're instantiating a local function declaration, put the result
1024  // in the owner;  otherwise we need to find the instantiated context.
1025  DeclContext *DC;
1026  if (D->getDeclContext()->isFunctionOrMethod())
1027    DC = Owner;
1028  else if (isFriend && Qualifier) {
1029    CXXScopeSpec SS;
1030    SS.setScopeRep(Qualifier);
1031    SS.setRange(D->getQualifierRange());
1032    DC = SemaRef.computeDeclContext(SS);
1033    if (!DC) return 0;
1034  } else {
1035    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1036                                         TemplateArgs);
1037  }
1038
1039  FunctionDecl *Function =
1040      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
1041                           D->getDeclName(), T, TInfo,
1042                           D->getStorageClass(), D->getStorageClassAsWritten(),
1043                           D->isInlineSpecified(), D->hasWrittenPrototype());
1044
1045  if (Qualifier)
1046    Function->setQualifierInfo(Qualifier, D->getQualifierRange());
1047
1048  DeclContext *LexicalDC = Owner;
1049  if (!isFriend && D->isOutOfLine()) {
1050    assert(D->getDeclContext()->isFileContext());
1051    LexicalDC = D->getDeclContext();
1052  }
1053
1054  Function->setLexicalDeclContext(LexicalDC);
1055
1056  // Attach the parameters
1057  for (unsigned P = 0; P < Params.size(); ++P)
1058    Params[P]->setOwningFunction(Function);
1059  Function->setParams(Params.data(), Params.size());
1060
1061  SourceLocation InstantiateAtPOI;
1062  if (TemplateParams) {
1063    // Our resulting instantiation is actually a function template, since we
1064    // are substituting only the outer template parameters. For example, given
1065    //
1066    //   template<typename T>
1067    //   struct X {
1068    //     template<typename U> friend void f(T, U);
1069    //   };
1070    //
1071    //   X<int> x;
1072    //
1073    // We are instantiating the friend function template "f" within X<int>,
1074    // which means substituting int for T, but leaving "f" as a friend function
1075    // template.
1076    // Build the function template itself.
1077    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1078                                                    Function->getLocation(),
1079                                                    Function->getDeclName(),
1080                                                    TemplateParams, Function);
1081    Function->setDescribedFunctionTemplate(FunctionTemplate);
1082
1083    FunctionTemplate->setLexicalDeclContext(LexicalDC);
1084
1085    if (isFriend && D->isThisDeclarationADefinition()) {
1086      // TODO: should we remember this connection regardless of whether
1087      // the friend declaration provided a body?
1088      FunctionTemplate->setInstantiatedFromMemberTemplate(
1089                                           D->getDescribedFunctionTemplate());
1090    }
1091  } else if (FunctionTemplate) {
1092    // Record this function template specialization.
1093    std::pair<const TemplateArgument *, unsigned> Innermost
1094      = TemplateArgs.getInnermost();
1095    Function->setFunctionTemplateSpecialization(FunctionTemplate,
1096                  new (SemaRef.Context) TemplateArgumentList(SemaRef.Context,
1097                                                             Innermost.first,
1098                                                             Innermost.second),
1099                                                InsertPos);
1100  } else if (isFriend && D->isThisDeclarationADefinition()) {
1101    // TODO: should we remember this connection regardless of whether
1102    // the friend declaration provided a body?
1103    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1104  }
1105
1106  if (InitFunctionInstantiation(Function, D))
1107    Function->setInvalidDecl();
1108
1109  bool Redeclaration = false;
1110  bool OverloadableAttrRequired = false;
1111  bool isExplicitSpecialization = false;
1112
1113  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1114                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1115
1116  if (DependentFunctionTemplateSpecializationInfo *Info
1117        = D->getDependentSpecializationInfo()) {
1118    assert(isFriend && "non-friend has dependent specialization info?");
1119
1120    // This needs to be set now for future sanity.
1121    Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1122
1123    // Instantiate the explicit template arguments.
1124    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1125                                          Info->getRAngleLoc());
1126    for (unsigned I = 0, E = Info->getNumTemplateArgs(); I != E; ++I) {
1127      TemplateArgumentLoc Loc;
1128      if (SemaRef.Subst(Info->getTemplateArg(I), Loc, TemplateArgs))
1129        return 0;
1130
1131      ExplicitArgs.addArgument(Loc);
1132    }
1133
1134    // Map the candidate templates to their instantiations.
1135    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1136      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1137                                                Info->getTemplate(I),
1138                                                TemplateArgs);
1139      if (!Temp) return 0;
1140
1141      Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1142    }
1143
1144    if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1145                                                    &ExplicitArgs,
1146                                                    Previous))
1147      Function->setInvalidDecl();
1148
1149    isExplicitSpecialization = true;
1150
1151  } else if (TemplateParams || !FunctionTemplate) {
1152    // Look only into the namespace where the friend would be declared to
1153    // find a previous declaration. This is the innermost enclosing namespace,
1154    // as described in ActOnFriendFunctionDecl.
1155    SemaRef.LookupQualifiedName(Previous, DC);
1156
1157    // In C++, the previous declaration we find might be a tag type
1158    // (class or enum). In this case, the new declaration will hide the
1159    // tag type. Note that this does does not apply if we're declaring a
1160    // typedef (C++ [dcl.typedef]p4).
1161    if (Previous.isSingleTagDecl())
1162      Previous.clear();
1163  }
1164
1165  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1166                                   isExplicitSpecialization, Redeclaration,
1167                                   /*FIXME:*/OverloadableAttrRequired);
1168
1169  NamedDecl *PrincipalDecl = (TemplateParams
1170                              ? cast<NamedDecl>(FunctionTemplate)
1171                              : Function);
1172
1173  // If the original function was part of a friend declaration,
1174  // inherit its namespace state and add it to the owner.
1175  if (isFriend) {
1176    NamedDecl *PrevDecl;
1177    if (TemplateParams)
1178      PrevDecl = FunctionTemplate->getPreviousDeclaration();
1179    else
1180      PrevDecl = Function->getPreviousDeclaration();
1181
1182    PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0);
1183    DC->makeDeclVisibleInContext(PrincipalDecl, /*Recoverable=*/ false);
1184
1185    if (!SemaRef.getLangOptions().CPlusPlus0x &&
1186        D->isThisDeclarationADefinition()) {
1187      // Check for a function body.
1188      const FunctionDecl *Definition = 0;
1189      if (Function->hasBody(Definition) &&
1190          Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1191        SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1192          << Function->getDeclName();
1193        SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1194        Function->setInvalidDecl();
1195      }
1196      // Check for redefinitions due to other instantiations of this or
1197      // a similar friend function.
1198      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1199                                           REnd = Function->redecls_end();
1200                R != REnd; ++R) {
1201        if (*R != Function &&
1202            ((*R)->getFriendObjectKind() != Decl::FOK_None)) {
1203          if (const FunctionDecl *RPattern
1204              = (*R)->getTemplateInstantiationPattern())
1205            if (RPattern->hasBody(RPattern)) {
1206              SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1207                << Function->getDeclName();
1208              SemaRef.Diag((*R)->getLocation(), diag::note_previous_definition);
1209              Function->setInvalidDecl();
1210              break;
1211            }
1212        }
1213      }
1214    }
1215
1216  }
1217
1218  if (Function->isOverloadedOperator() && !DC->isRecord() &&
1219      PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1220    PrincipalDecl->setNonMemberOperator();
1221
1222  return Function;
1223}
1224
1225Decl *
1226TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1227                                      TemplateParameterList *TemplateParams) {
1228  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1229  void *InsertPos = 0;
1230  if (FunctionTemplate && !TemplateParams) {
1231    // We are creating a function template specialization from a function
1232    // template. Check whether there is already a function template
1233    // specialization for this particular set of template arguments.
1234    llvm::FoldingSetNodeID ID;
1235    std::pair<const TemplateArgument *, unsigned> Innermost
1236      = TemplateArgs.getInnermost();
1237    FunctionTemplateSpecializationInfo::Profile(ID, Innermost.first,
1238                                                Innermost.second,
1239                                                SemaRef.Context);
1240
1241    FunctionTemplateSpecializationInfo *Info
1242      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
1243                                                                   InsertPos);
1244
1245    // If we already have a function template specialization, return it.
1246    if (Info)
1247      return Info->Function;
1248  }
1249
1250  bool isFriend;
1251  if (FunctionTemplate)
1252    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1253  else
1254    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1255
1256  bool MergeWithParentScope = (TemplateParams != 0) ||
1257    !(isa<Decl>(Owner) &&
1258      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1259  Sema::LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1260
1261  llvm::SmallVector<ParmVarDecl *, 4> Params;
1262  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1263  TInfo = SubstFunctionType(D, Params);
1264  if (!TInfo)
1265    return 0;
1266  QualType T = TInfo->getType();
1267
1268  // \brief If the type of this function is not *directly* a function
1269  // type, then we're instantiating the a function that was declared
1270  // via a typedef, e.g.,
1271  //
1272  //   typedef int functype(int, int);
1273  //   functype func;
1274  //
1275  // In this case, we'll just go instantiate the ParmVarDecls that we
1276  // synthesized in the method declaration.
1277  if (!isa<FunctionProtoType>(T)) {
1278    assert(!Params.size() && "Instantiating type could not yield parameters");
1279    for (unsigned I = 0, N = D->getNumParams(); I != N; ++I) {
1280      ParmVarDecl *P = SemaRef.SubstParmVarDecl(D->getParamDecl(I),
1281                                                TemplateArgs);
1282      if (!P)
1283        return 0;
1284
1285      Params.push_back(P);
1286    }
1287  }
1288
1289  NestedNameSpecifier *Qualifier = D->getQualifier();
1290  if (Qualifier) {
1291    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1292                                                 D->getQualifierRange(),
1293                                                 TemplateArgs);
1294    if (!Qualifier) return 0;
1295  }
1296
1297  DeclContext *DC = Owner;
1298  if (isFriend) {
1299    if (Qualifier) {
1300      CXXScopeSpec SS;
1301      SS.setScopeRep(Qualifier);
1302      SS.setRange(D->getQualifierRange());
1303      DC = SemaRef.computeDeclContext(SS);
1304    } else {
1305      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1306                                           D->getDeclContext(),
1307                                           TemplateArgs);
1308    }
1309    if (!DC) return 0;
1310  }
1311
1312  // Build the instantiated method declaration.
1313  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1314  CXXMethodDecl *Method = 0;
1315
1316  DeclarationName Name = D->getDeclName();
1317  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1318    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1319    Name = SemaRef.Context.DeclarationNames.getCXXConstructorName(
1320                                    SemaRef.Context.getCanonicalType(ClassTy));
1321    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1322                                        Constructor->getLocation(),
1323                                        Name, T, TInfo,
1324                                        Constructor->isExplicit(),
1325                                        Constructor->isInlineSpecified(),
1326                                        false);
1327  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1328    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
1329    Name = SemaRef.Context.DeclarationNames.getCXXDestructorName(
1330                                   SemaRef.Context.getCanonicalType(ClassTy));
1331    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1332                                       Destructor->getLocation(), Name,
1333                                       T, Destructor->isInlineSpecified(),
1334                                       false);
1335  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1336    CanQualType ConvTy
1337      = SemaRef.Context.getCanonicalType(
1338                                      T->getAs<FunctionType>()->getResultType());
1339    Name = SemaRef.Context.DeclarationNames.getCXXConversionFunctionName(
1340                                                                      ConvTy);
1341    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1342                                       Conversion->getLocation(), Name,
1343                                       T, TInfo,
1344                                       Conversion->isInlineSpecified(),
1345                                       Conversion->isExplicit());
1346  } else {
1347    Method = CXXMethodDecl::Create(SemaRef.Context, Record, D->getLocation(),
1348                                   D->getDeclName(), T, TInfo,
1349                                   D->isStatic(),
1350                                   D->getStorageClassAsWritten(),
1351                                   D->isInlineSpecified());
1352  }
1353
1354  if (Qualifier)
1355    Method->setQualifierInfo(Qualifier, D->getQualifierRange());
1356
1357  if (TemplateParams) {
1358    // Our resulting instantiation is actually a function template, since we
1359    // are substituting only the outer template parameters. For example, given
1360    //
1361    //   template<typename T>
1362    //   struct X {
1363    //     template<typename U> void f(T, U);
1364    //   };
1365    //
1366    //   X<int> x;
1367    //
1368    // We are instantiating the member template "f" within X<int>, which means
1369    // substituting int for T, but leaving "f" as a member function template.
1370    // Build the function template itself.
1371    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1372                                                    Method->getLocation(),
1373                                                    Method->getDeclName(),
1374                                                    TemplateParams, Method);
1375    if (isFriend) {
1376      FunctionTemplate->setLexicalDeclContext(Owner);
1377      FunctionTemplate->setObjectOfFriendDecl(true);
1378    } else if (D->isOutOfLine())
1379      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1380    Method->setDescribedFunctionTemplate(FunctionTemplate);
1381  } else if (FunctionTemplate) {
1382    // Record this function template specialization.
1383    std::pair<const TemplateArgument *, unsigned> Innermost
1384      = TemplateArgs.getInnermost();
1385    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1386                    new (SemaRef.Context) TemplateArgumentList(SemaRef.Context,
1387                                                              Innermost.first,
1388                                                              Innermost.second),
1389                                              InsertPos);
1390  } else if (!isFriend) {
1391    // Record that this is an instantiation of a member function.
1392    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1393  }
1394
1395  // If we are instantiating a member function defined
1396  // out-of-line, the instantiation will have the same lexical
1397  // context (which will be a namespace scope) as the template.
1398  if (isFriend) {
1399    Method->setLexicalDeclContext(Owner);
1400    Method->setObjectOfFriendDecl(true);
1401  } else if (D->isOutOfLine())
1402    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1403
1404  // Attach the parameters
1405  for (unsigned P = 0; P < Params.size(); ++P)
1406    Params[P]->setOwningFunction(Method);
1407  Method->setParams(Params.data(), Params.size());
1408
1409  if (InitMethodInstantiation(Method, D))
1410    Method->setInvalidDecl();
1411
1412  LookupResult Previous(SemaRef, Name, SourceLocation(),
1413                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1414
1415  if (!FunctionTemplate || TemplateParams || isFriend) {
1416    SemaRef.LookupQualifiedName(Previous, Record);
1417
1418    // In C++, the previous declaration we find might be a tag type
1419    // (class or enum). In this case, the new declaration will hide the
1420    // tag type. Note that this does does not apply if we're declaring a
1421    // typedef (C++ [dcl.typedef]p4).
1422    if (Previous.isSingleTagDecl())
1423      Previous.clear();
1424  }
1425
1426  bool Redeclaration = false;
1427  bool OverloadableAttrRequired = false;
1428  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1429                                   /*FIXME:*/OverloadableAttrRequired);
1430
1431  if (D->isPure())
1432    SemaRef.CheckPureMethod(Method, SourceRange());
1433
1434  Method->setAccess(D->getAccess());
1435
1436  if (FunctionTemplate) {
1437    // If there's a function template, let our caller handle it.
1438  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1439    // Don't hide a (potentially) valid declaration with an invalid one.
1440  } else {
1441    NamedDecl *DeclToAdd = (TemplateParams
1442                            ? cast<NamedDecl>(FunctionTemplate)
1443                            : Method);
1444    if (isFriend)
1445      Record->makeDeclVisibleInContext(DeclToAdd);
1446    else
1447      Owner->addDecl(DeclToAdd);
1448  }
1449
1450  return Method;
1451}
1452
1453Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1454  return VisitCXXMethodDecl(D);
1455}
1456
1457Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1458  return VisitCXXMethodDecl(D);
1459}
1460
1461Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1462  return VisitCXXMethodDecl(D);
1463}
1464
1465ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1466  return SemaRef.SubstParmVarDecl(D, TemplateArgs);
1467}
1468
1469Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1470                                                    TemplateTypeParmDecl *D) {
1471  // TODO: don't always clone when decls are refcounted.
1472  const Type* T = D->getTypeForDecl();
1473  assert(T->isTemplateTypeParmType());
1474  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1475
1476  TemplateTypeParmDecl *Inst =
1477    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1478                                 TTPT->getDepth() - 1, TTPT->getIndex(),
1479                                 TTPT->getName(),
1480                                 D->wasDeclaredWithTypename(),
1481                                 D->isParameterPack());
1482
1483  if (D->hasDefaultArgument())
1484    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1485
1486  // Introduce this template parameter's instantiation into the instantiation
1487  // scope.
1488  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1489
1490  return Inst;
1491}
1492
1493Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1494                                                 NonTypeTemplateParmDecl *D) {
1495  // Substitute into the type of the non-type template parameter.
1496  QualType T;
1497  TypeSourceInfo *DI = D->getTypeSourceInfo();
1498  if (DI) {
1499    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1500                           D->getDeclName());
1501    if (DI) T = DI->getType();
1502  } else {
1503    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1504                          D->getDeclName());
1505    DI = 0;
1506  }
1507  if (T.isNull())
1508    return 0;
1509
1510  // Check that this type is acceptable for a non-type template parameter.
1511  bool Invalid = false;
1512  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1513  if (T.isNull()) {
1514    T = SemaRef.Context.IntTy;
1515    Invalid = true;
1516  }
1517
1518  NonTypeTemplateParmDecl *Param
1519    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1520                                      D->getDepth() - 1, D->getPosition(),
1521                                      D->getIdentifier(), T, DI);
1522  if (Invalid)
1523    Param->setInvalidDecl();
1524
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  return Param;
1531}
1532
1533Decl *
1534TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1535                                                  TemplateTemplateParmDecl *D) {
1536  // Instantiate the template parameter list of the template template parameter.
1537  TemplateParameterList *TempParams = D->getTemplateParameters();
1538  TemplateParameterList *InstParams;
1539  {
1540    // Perform the actual substitution of template parameters within a new,
1541    // local instantiation scope.
1542    Sema::LocalInstantiationScope Scope(SemaRef);
1543    InstParams = SubstTemplateParams(TempParams);
1544    if (!InstParams)
1545      return NULL;
1546  }
1547
1548  // Build the template template parameter.
1549  TemplateTemplateParmDecl *Param
1550    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1551                                       D->getDepth() - 1, D->getPosition(),
1552                                       D->getIdentifier(), InstParams);
1553  Param->setDefaultArgument(D->getDefaultArgument(), false);
1554
1555  // Introduce this template parameter's instantiation into the instantiation
1556  // scope.
1557  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1558
1559  return Param;
1560}
1561
1562Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1563  // Using directives are never dependent, so they require no explicit
1564
1565  UsingDirectiveDecl *Inst
1566    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1567                                 D->getNamespaceKeyLocation(),
1568                                 D->getQualifierRange(), D->getQualifier(),
1569                                 D->getIdentLocation(),
1570                                 D->getNominatedNamespace(),
1571                                 D->getCommonAncestor());
1572  Owner->addDecl(Inst);
1573  return Inst;
1574}
1575
1576Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1577  // The nested name specifier is non-dependent, so no transformation
1578  // is required.
1579
1580  // We only need to do redeclaration lookups if we're in a class
1581  // scope (in fact, it's not really even possible in non-class
1582  // scopes).
1583  bool CheckRedeclaration = Owner->isRecord();
1584
1585  LookupResult Prev(SemaRef, D->getDeclName(), D->getLocation(),
1586                    Sema::LookupUsingDeclName, Sema::ForRedeclaration);
1587
1588  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1589                                       D->getLocation(),
1590                                       D->getNestedNameRange(),
1591                                       D->getUsingLocation(),
1592                                       D->getTargetNestedNameDecl(),
1593                                       D->getDeclName(),
1594                                       D->isTypeName());
1595
1596  CXXScopeSpec SS;
1597  SS.setScopeRep(D->getTargetNestedNameDecl());
1598  SS.setRange(D->getNestedNameRange());
1599
1600  if (CheckRedeclaration) {
1601    Prev.setHideTags(false);
1602    SemaRef.LookupQualifiedName(Prev, Owner);
1603
1604    // Check for invalid redeclarations.
1605    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1606                                            D->isTypeName(), SS,
1607                                            D->getLocation(), Prev))
1608      NewUD->setInvalidDecl();
1609
1610  }
1611
1612  if (!NewUD->isInvalidDecl() &&
1613      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1614                                      D->getLocation()))
1615    NewUD->setInvalidDecl();
1616
1617  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1618  NewUD->setAccess(D->getAccess());
1619  Owner->addDecl(NewUD);
1620
1621  // Don't process the shadow decls for an invalid decl.
1622  if (NewUD->isInvalidDecl())
1623    return NewUD;
1624
1625  bool isFunctionScope = Owner->isFunctionOrMethod();
1626
1627  // Process the shadow decls.
1628  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1629         I != E; ++I) {
1630    UsingShadowDecl *Shadow = *I;
1631    NamedDecl *InstTarget =
1632      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1633                                                   Shadow->getTargetDecl(),
1634                                                   TemplateArgs));
1635
1636    if (CheckRedeclaration &&
1637        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1638      continue;
1639
1640    UsingShadowDecl *InstShadow
1641      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1642    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1643
1644    if (isFunctionScope)
1645      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1646  }
1647
1648  return NewUD;
1649}
1650
1651Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1652  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1653  return 0;
1654}
1655
1656Decl * TemplateDeclInstantiator
1657    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1658  NestedNameSpecifier *NNS =
1659    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1660                                     D->getTargetNestedNameRange(),
1661                                     TemplateArgs);
1662  if (!NNS)
1663    return 0;
1664
1665  CXXScopeSpec SS;
1666  SS.setRange(D->getTargetNestedNameRange());
1667  SS.setScopeRep(NNS);
1668
1669  NamedDecl *UD =
1670    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1671                                  D->getUsingLoc(), SS, D->getLocation(),
1672                                  D->getDeclName(), 0,
1673                                  /*instantiation*/ true,
1674                                  /*typename*/ true, D->getTypenameLoc());
1675  if (UD)
1676    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1677
1678  return UD;
1679}
1680
1681Decl * TemplateDeclInstantiator
1682    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1683  NestedNameSpecifier *NNS =
1684    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1685                                     D->getTargetNestedNameRange(),
1686                                     TemplateArgs);
1687  if (!NNS)
1688    return 0;
1689
1690  CXXScopeSpec SS;
1691  SS.setRange(D->getTargetNestedNameRange());
1692  SS.setScopeRep(NNS);
1693
1694  NamedDecl *UD =
1695    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1696                                  D->getUsingLoc(), SS, D->getLocation(),
1697                                  D->getDeclName(), 0,
1698                                  /*instantiation*/ true,
1699                                  /*typename*/ false, SourceLocation());
1700  if (UD)
1701    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1702
1703  return UD;
1704}
1705
1706Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1707                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1708  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1709  if (D->isInvalidDecl())
1710    return 0;
1711
1712  return Instantiator.Visit(D);
1713}
1714
1715/// \brief Instantiates a nested template parameter list in the current
1716/// instantiation context.
1717///
1718/// \param L The parameter list to instantiate
1719///
1720/// \returns NULL if there was an error
1721TemplateParameterList *
1722TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1723  // Get errors for all the parameters before bailing out.
1724  bool Invalid = false;
1725
1726  unsigned N = L->size();
1727  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1728  ParamVector Params;
1729  Params.reserve(N);
1730  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1731       PI != PE; ++PI) {
1732    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1733    Params.push_back(D);
1734    Invalid = Invalid || !D || D->isInvalidDecl();
1735  }
1736
1737  // Clean up if we had an error.
1738  if (Invalid) {
1739    for (ParamVector::iterator PI = Params.begin(), PE = Params.end();
1740         PI != PE; ++PI)
1741      if (*PI)
1742        (*PI)->Destroy(SemaRef.Context);
1743    return NULL;
1744  }
1745
1746  TemplateParameterList *InstL
1747    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1748                                    L->getLAngleLoc(), &Params.front(), N,
1749                                    L->getRAngleLoc());
1750  return InstL;
1751}
1752
1753/// \brief Instantiate the declaration of a class template partial
1754/// specialization.
1755///
1756/// \param ClassTemplate the (instantiated) class template that is partially
1757// specialized by the instantiation of \p PartialSpec.
1758///
1759/// \param PartialSpec the (uninstantiated) class template partial
1760/// specialization that we are instantiating.
1761///
1762/// \returns true if there was an error, false otherwise.
1763bool
1764TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1765                                            ClassTemplateDecl *ClassTemplate,
1766                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1767  // Create a local instantiation scope for this class template partial
1768  // specialization, which will contain the instantiations of the template
1769  // parameters.
1770  Sema::LocalInstantiationScope Scope(SemaRef);
1771
1772  // Substitute into the template parameters of the class template partial
1773  // specialization.
1774  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1775  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1776  if (!InstParams)
1777    return true;
1778
1779  // Substitute into the template arguments of the class template partial
1780  // specialization.
1781  const TemplateArgumentLoc *PartialSpecTemplateArgs
1782    = PartialSpec->getTemplateArgsAsWritten();
1783  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1784
1785  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1786  for (unsigned I = 0; I != N; ++I) {
1787    TemplateArgumentLoc Loc;
1788    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1789      return true;
1790    InstTemplateArgs.addArgument(Loc);
1791  }
1792
1793
1794  // Check that the template argument list is well-formed for this
1795  // class template.
1796  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1797                                        InstTemplateArgs.size());
1798  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1799                                        PartialSpec->getLocation(),
1800                                        InstTemplateArgs,
1801                                        false,
1802                                        Converted))
1803    return true;
1804
1805  // Figure out where to insert this class template partial specialization
1806  // in the member template's set of class template partial specializations.
1807  llvm::FoldingSetNodeID ID;
1808  ClassTemplatePartialSpecializationDecl::Profile(ID,
1809                                                  Converted.getFlatArguments(),
1810                                                  Converted.flatSize(),
1811                                                  SemaRef.Context);
1812  void *InsertPos = 0;
1813  ClassTemplateSpecializationDecl *PrevDecl
1814    = ClassTemplate->getPartialSpecializations().FindNodeOrInsertPos(ID,
1815                                                                     InsertPos);
1816
1817  // Build the canonical type that describes the converted template
1818  // arguments of the class template partial specialization.
1819  QualType CanonType
1820    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1821                                                  Converted.getFlatArguments(),
1822                                                    Converted.flatSize());
1823
1824  // Build the fully-sugared type for this class template
1825  // specialization as the user wrote in the specialization
1826  // itself. This means that we'll pretty-print the type retrieved
1827  // from the specialization's declaration the way that the user
1828  // actually wrote the specialization, rather than formatting the
1829  // name based on the "canonical" representation used to store the
1830  // template arguments in the specialization.
1831  TypeSourceInfo *WrittenTy
1832    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1833                                                    TemplateName(ClassTemplate),
1834                                                    PartialSpec->getLocation(),
1835                                                    InstTemplateArgs,
1836                                                    CanonType);
1837
1838  if (PrevDecl) {
1839    // We've already seen a partial specialization with the same template
1840    // parameters and template arguments. This can happen, for example, when
1841    // substituting the outer template arguments ends up causing two
1842    // class template partial specializations of a member class template
1843    // to have identical forms, e.g.,
1844    //
1845    //   template<typename T, typename U>
1846    //   struct Outer {
1847    //     template<typename X, typename Y> struct Inner;
1848    //     template<typename Y> struct Inner<T, Y>;
1849    //     template<typename Y> struct Inner<U, Y>;
1850    //   };
1851    //
1852    //   Outer<int, int> outer; // error: the partial specializations of Inner
1853    //                          // have the same signature.
1854    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1855      << WrittenTy;
1856    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1857      << SemaRef.Context.getTypeDeclType(PrevDecl);
1858    return true;
1859  }
1860
1861
1862  // Create the class template partial specialization declaration.
1863  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1864    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
1865                                                     PartialSpec->getTagKind(),
1866                                                     Owner,
1867                                                     PartialSpec->getLocation(),
1868                                                     InstParams,
1869                                                     ClassTemplate,
1870                                                     Converted,
1871                                                     InstTemplateArgs,
1872                                                     CanonType,
1873                                                     0,
1874                             ClassTemplate->getPartialSpecializations().size());
1875  // Substitute the nested name specifier, if any.
1876  if (SubstQualifier(PartialSpec, InstPartialSpec))
1877    return 0;
1878
1879  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1880  InstPartialSpec->setTypeAsWritten(WrittenTy);
1881
1882  // Add this partial specialization to the set of class template partial
1883  // specializations.
1884  ClassTemplate->getPartialSpecializations().InsertNode(InstPartialSpec,
1885                                                        InsertPos);
1886  return false;
1887}
1888
1889TypeSourceInfo*
1890TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1891                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1892  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1893  assert(OldTInfo && "substituting function without type source info");
1894  assert(Params.empty() && "parameter vector is non-empty at start");
1895  TypeSourceInfo *NewTInfo
1896    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
1897                                    D->getTypeSpecStartLoc(),
1898                                    D->getDeclName());
1899  if (!NewTInfo)
1900    return 0;
1901
1902  if (NewTInfo != OldTInfo) {
1903    // Get parameters from the new type info.
1904    TypeLoc OldTL = OldTInfo->getTypeLoc();
1905    if (FunctionProtoTypeLoc *OldProtoLoc
1906                                  = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1907      TypeLoc NewTL = NewTInfo->getTypeLoc();
1908      FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1909      assert(NewProtoLoc && "Missing prototype?");
1910      for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i) {
1911        // FIXME: Variadic templates will break this.
1912        Params.push_back(NewProtoLoc->getArg(i));
1913        SemaRef.CurrentInstantiationScope->InstantiatedLocal(
1914                                                        OldProtoLoc->getArg(i),
1915                                                        NewProtoLoc->getArg(i));
1916      }
1917    }
1918  } else {
1919    // The function type itself was not dependent and therefore no
1920    // substitution occurred. However, we still need to instantiate
1921    // the function parameters themselves.
1922    TypeLoc OldTL = OldTInfo->getTypeLoc();
1923    if (FunctionProtoTypeLoc *OldProtoLoc
1924                                    = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1925      for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
1926        ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
1927        if (!Parm)
1928          return 0;
1929        Params.push_back(Parm);
1930      }
1931    }
1932  }
1933  return NewTInfo;
1934}
1935
1936/// \brief Initializes the common fields of an instantiation function
1937/// declaration (New) from the corresponding fields of its template (Tmpl).
1938///
1939/// \returns true if there was an error
1940bool
1941TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1942                                                    FunctionDecl *Tmpl) {
1943  if (Tmpl->isDeleted())
1944    New->setDeleted();
1945
1946  // If we are performing substituting explicitly-specified template arguments
1947  // or deduced template arguments into a function template and we reach this
1948  // point, we are now past the point where SFINAE applies and have committed
1949  // to keeping the new function template specialization. We therefore
1950  // convert the active template instantiation for the function template
1951  // into a template instantiation for this specific function template
1952  // specialization, which is not a SFINAE context, so that we diagnose any
1953  // further errors in the declaration itself.
1954  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1955  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1956  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1957      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1958    if (FunctionTemplateDecl *FunTmpl
1959          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1960      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1961             "Deduction from the wrong function template?");
1962      (void) FunTmpl;
1963      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1964      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1965      --SemaRef.NonInstantiationEntries;
1966    }
1967  }
1968
1969  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1970  assert(Proto && "Function template without prototype?");
1971
1972  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1973      Proto->getNoReturnAttr()) {
1974    // The function has an exception specification or a "noreturn"
1975    // attribute. Substitute into each of the exception types.
1976    llvm::SmallVector<QualType, 4> Exceptions;
1977    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1978      // FIXME: Poor location information!
1979      QualType T
1980        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1981                            New->getLocation(), New->getDeclName());
1982      if (T.isNull() ||
1983          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1984        continue;
1985
1986      Exceptions.push_back(T);
1987    }
1988
1989    // Rebuild the function type
1990
1991    const FunctionProtoType *NewProto
1992      = New->getType()->getAs<FunctionProtoType>();
1993    assert(NewProto && "Template instantiation without function prototype?");
1994    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1995                                                 NewProto->arg_type_begin(),
1996                                                 NewProto->getNumArgs(),
1997                                                 NewProto->isVariadic(),
1998                                                 NewProto->getTypeQuals(),
1999                                                 Proto->hasExceptionSpec(),
2000                                                 Proto->hasAnyExceptionSpec(),
2001                                                 Exceptions.size(),
2002                                                 Exceptions.data(),
2003                                                 Proto->getExtInfo()));
2004  }
2005
2006  InstantiateAttrs(Tmpl, New);
2007
2008  return false;
2009}
2010
2011/// \brief Initializes common fields of an instantiated method
2012/// declaration (New) from the corresponding fields of its template
2013/// (Tmpl).
2014///
2015/// \returns true if there was an error
2016bool
2017TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
2018                                                  CXXMethodDecl *Tmpl) {
2019  if (InitFunctionInstantiation(New, Tmpl))
2020    return true;
2021
2022  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
2023  New->setAccess(Tmpl->getAccess());
2024  if (Tmpl->isVirtualAsWritten())
2025    Record->setMethodAsVirtual(New);
2026
2027  // FIXME: attributes
2028  // FIXME: New needs a pointer to Tmpl
2029  return false;
2030}
2031
2032/// \brief Instantiate the definition of the given function from its
2033/// template.
2034///
2035/// \param PointOfInstantiation the point at which the instantiation was
2036/// required. Note that this is not precisely a "point of instantiation"
2037/// for the function, but it's close.
2038///
2039/// \param Function the already-instantiated declaration of a
2040/// function template specialization or member function of a class template
2041/// specialization.
2042///
2043/// \param Recursive if true, recursively instantiates any functions that
2044/// are required by this instantiation.
2045///
2046/// \param DefinitionRequired if true, then we are performing an explicit
2047/// instantiation where the body of the function is required. Complain if
2048/// there is no such body.
2049void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
2050                                         FunctionDecl *Function,
2051                                         bool Recursive,
2052                                         bool DefinitionRequired) {
2053  if (Function->isInvalidDecl() || Function->hasBody())
2054    return;
2055
2056  // Never instantiate an explicit specialization.
2057  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2058    return;
2059
2060  // Find the function body that we'll be substituting.
2061  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
2062  Stmt *Pattern = 0;
2063  if (PatternDecl)
2064    Pattern = PatternDecl->getBody(PatternDecl);
2065
2066  if (!Pattern) {
2067    if (DefinitionRequired) {
2068      if (Function->getPrimaryTemplate())
2069        Diag(PointOfInstantiation,
2070             diag::err_explicit_instantiation_undefined_func_template)
2071          << Function->getPrimaryTemplate();
2072      else
2073        Diag(PointOfInstantiation,
2074             diag::err_explicit_instantiation_undefined_member)
2075          << 1 << Function->getDeclName() << Function->getDeclContext();
2076
2077      if (PatternDecl)
2078        Diag(PatternDecl->getLocation(),
2079             diag::note_explicit_instantiation_here);
2080      Function->setInvalidDecl();
2081    }
2082
2083    return;
2084  }
2085
2086  // C++0x [temp.explicit]p9:
2087  //   Except for inline functions, other explicit instantiation declarations
2088  //   have the effect of suppressing the implicit instantiation of the entity
2089  //   to which they refer.
2090  if (Function->getTemplateSpecializationKind()
2091        == TSK_ExplicitInstantiationDeclaration &&
2092      !PatternDecl->isInlined())
2093    return;
2094
2095  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2096  if (Inst)
2097    return;
2098
2099  // If we're performing recursive template instantiation, create our own
2100  // queue of pending implicit instantiations that we will instantiate later,
2101  // while we're still within our own instantiation context.
2102  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2103  if (Recursive)
2104    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2105
2106  EnterExpressionEvaluationContext EvalContext(*this,
2107                                               Action::PotentiallyEvaluated);
2108  ActOnStartOfFunctionDef(0, DeclPtrTy::make(Function));
2109
2110  // Introduce a new scope where local variable instantiations will be
2111  // recorded, unless we're actually a member function within a local
2112  // class, in which case we need to merge our results with the parent
2113  // scope (of the enclosing function).
2114  bool MergeWithParentScope = false;
2115  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2116    MergeWithParentScope = Rec->isLocalClass();
2117
2118  LocalInstantiationScope Scope(*this, MergeWithParentScope);
2119
2120  // Introduce the instantiated function parameters into the local
2121  // instantiation scope.
2122  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I)
2123    Scope.InstantiatedLocal(PatternDecl->getParamDecl(I),
2124                            Function->getParamDecl(I));
2125
2126  // Enter the scope of this instantiation. We don't use
2127  // PushDeclContext because we don't have a scope.
2128  DeclContext *PreviousContext = CurContext;
2129  CurContext = Function;
2130
2131  MultiLevelTemplateArgumentList TemplateArgs =
2132    getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
2133
2134  // If this is a constructor, instantiate the member initializers.
2135  if (const CXXConstructorDecl *Ctor =
2136        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2137    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2138                               TemplateArgs);
2139  }
2140
2141  // Instantiate the function body.
2142  OwningStmtResult Body = SubstStmt(Pattern, TemplateArgs);
2143
2144  if (Body.isInvalid())
2145    Function->setInvalidDecl();
2146
2147  ActOnFinishFunctionBody(DeclPtrTy::make(Function), move(Body),
2148                          /*IsInstantiation=*/true);
2149
2150  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2151
2152  CurContext = PreviousContext;
2153
2154  DeclGroupRef DG(Function);
2155  Consumer.HandleTopLevelDecl(DG);
2156
2157  // This class may have local implicit instantiations that need to be
2158  // instantiation within this scope.
2159  PerformPendingImplicitInstantiations(/*LocalOnly=*/true);
2160  Scope.Exit();
2161
2162  if (Recursive) {
2163    // Instantiate any pending implicit instantiations found during the
2164    // instantiation of this template.
2165    PerformPendingImplicitInstantiations();
2166
2167    // Restore the set of pending implicit instantiations.
2168    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2169  }
2170}
2171
2172/// \brief Instantiate the definition of the given variable from its
2173/// template.
2174///
2175/// \param PointOfInstantiation the point at which the instantiation was
2176/// required. Note that this is not precisely a "point of instantiation"
2177/// for the function, but it's close.
2178///
2179/// \param Var the already-instantiated declaration of a static member
2180/// variable of a class template specialization.
2181///
2182/// \param Recursive if true, recursively instantiates any functions that
2183/// are required by this instantiation.
2184///
2185/// \param DefinitionRequired if true, then we are performing an explicit
2186/// instantiation where an out-of-line definition of the member variable
2187/// is required. Complain if there is no such definition.
2188void Sema::InstantiateStaticDataMemberDefinition(
2189                                          SourceLocation PointOfInstantiation,
2190                                                 VarDecl *Var,
2191                                                 bool Recursive,
2192                                                 bool DefinitionRequired) {
2193  if (Var->isInvalidDecl())
2194    return;
2195
2196  // Find the out-of-line definition of this static data member.
2197  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2198  assert(Def && "This data member was not instantiated from a template?");
2199  assert(Def->isStaticDataMember() && "Not a static data member?");
2200  Def = Def->getOutOfLineDefinition();
2201
2202  if (!Def) {
2203    // We did not find an out-of-line definition of this static data member,
2204    // so we won't perform any instantiation. Rather, we rely on the user to
2205    // instantiate this definition (or provide a specialization for it) in
2206    // another translation unit.
2207    if (DefinitionRequired) {
2208      Def = Var->getInstantiatedFromStaticDataMember();
2209      Diag(PointOfInstantiation,
2210           diag::err_explicit_instantiation_undefined_member)
2211        << 2 << Var->getDeclName() << Var->getDeclContext();
2212      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2213    }
2214
2215    return;
2216  }
2217
2218  // Never instantiate an explicit specialization.
2219  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2220    return;
2221
2222  // C++0x [temp.explicit]p9:
2223  //   Except for inline functions, other explicit instantiation declarations
2224  //   have the effect of suppressing the implicit instantiation of the entity
2225  //   to which they refer.
2226  if (Var->getTemplateSpecializationKind()
2227        == TSK_ExplicitInstantiationDeclaration)
2228    return;
2229
2230  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2231  if (Inst)
2232    return;
2233
2234  // If we're performing recursive template instantiation, create our own
2235  // queue of pending implicit instantiations that we will instantiate later,
2236  // while we're still within our own instantiation context.
2237  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
2238  if (Recursive)
2239    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2240
2241  // Enter the scope of this instantiation. We don't use
2242  // PushDeclContext because we don't have a scope.
2243  DeclContext *PreviousContext = CurContext;
2244  CurContext = Var->getDeclContext();
2245
2246  VarDecl *OldVar = Var;
2247  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2248                                          getTemplateInstantiationArgs(Var)));
2249  CurContext = PreviousContext;
2250
2251  if (Var) {
2252    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2253    assert(MSInfo && "Missing member specialization information?");
2254    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2255                                       MSInfo->getPointOfInstantiation());
2256    DeclGroupRef DG(Var);
2257    Consumer.HandleTopLevelDecl(DG);
2258  }
2259
2260  if (Recursive) {
2261    // Instantiate any pending implicit instantiations found during the
2262    // instantiation of this template.
2263    PerformPendingImplicitInstantiations();
2264
2265    // Restore the set of pending implicit instantiations.
2266    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
2267  }
2268}
2269
2270void
2271Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2272                                 const CXXConstructorDecl *Tmpl,
2273                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2274
2275  llvm::SmallVector<MemInitTy*, 4> NewInits;
2276  bool AnyErrors = false;
2277
2278  // Instantiate all the initializers.
2279  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2280                                            InitsEnd = Tmpl->init_end();
2281       Inits != InitsEnd; ++Inits) {
2282    CXXBaseOrMemberInitializer *Init = *Inits;
2283
2284    SourceLocation LParenLoc, RParenLoc;
2285    ASTOwningVector<&ActionBase::DeleteExpr> NewArgs(*this);
2286    llvm::SmallVector<SourceLocation, 4> CommaLocs;
2287
2288    // Instantiate the initializer.
2289    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2290                               LParenLoc, CommaLocs, NewArgs, RParenLoc)) {
2291      AnyErrors = true;
2292      continue;
2293    }
2294
2295    MemInitResult NewInit;
2296    if (Init->isBaseInitializer()) {
2297      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2298                                            TemplateArgs,
2299                                            Init->getSourceLocation(),
2300                                            New->getDeclName());
2301      if (!BaseTInfo) {
2302        AnyErrors = true;
2303        New->setInvalidDecl();
2304        continue;
2305      }
2306
2307      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2308                                     (Expr **)NewArgs.data(),
2309                                     NewArgs.size(),
2310                                     Init->getLParenLoc(),
2311                                     Init->getRParenLoc(),
2312                                     New->getParent());
2313    } else if (Init->isMemberInitializer()) {
2314      FieldDecl *Member;
2315
2316      // Is this an anonymous union?
2317      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2318        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2319                                                      UnionInit, TemplateArgs));
2320      else
2321        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2322                                                      Init->getMember(),
2323                                                      TemplateArgs));
2324
2325      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2326                                       NewArgs.size(),
2327                                       Init->getSourceLocation(),
2328                                       Init->getLParenLoc(),
2329                                       Init->getRParenLoc());
2330    }
2331
2332    if (NewInit.isInvalid()) {
2333      AnyErrors = true;
2334      New->setInvalidDecl();
2335    } else {
2336      // FIXME: It would be nice if ASTOwningVector had a release function.
2337      NewArgs.take();
2338
2339      NewInits.push_back((MemInitTy *)NewInit.get());
2340    }
2341  }
2342
2343  // Assign all the initializers to the new constructor.
2344  ActOnMemInitializers(DeclPtrTy::make(New),
2345                       /*FIXME: ColonLoc */
2346                       SourceLocation(),
2347                       NewInits.data(), NewInits.size(),
2348                       AnyErrors);
2349}
2350
2351// TODO: this could be templated if the various decl types used the
2352// same method name.
2353static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2354                              ClassTemplateDecl *Instance) {
2355  Pattern = Pattern->getCanonicalDecl();
2356
2357  do {
2358    Instance = Instance->getCanonicalDecl();
2359    if (Pattern == Instance) return true;
2360    Instance = Instance->getInstantiatedFromMemberTemplate();
2361  } while (Instance);
2362
2363  return false;
2364}
2365
2366static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2367                              FunctionTemplateDecl *Instance) {
2368  Pattern = Pattern->getCanonicalDecl();
2369
2370  do {
2371    Instance = Instance->getCanonicalDecl();
2372    if (Pattern == Instance) return true;
2373    Instance = Instance->getInstantiatedFromMemberTemplate();
2374  } while (Instance);
2375
2376  return false;
2377}
2378
2379static bool
2380isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2381                  ClassTemplatePartialSpecializationDecl *Instance) {
2382  Pattern
2383    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2384  do {
2385    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2386                                                Instance->getCanonicalDecl());
2387    if (Pattern == Instance)
2388      return true;
2389    Instance = Instance->getInstantiatedFromMember();
2390  } while (Instance);
2391
2392  return false;
2393}
2394
2395static bool isInstantiationOf(CXXRecordDecl *Pattern,
2396                              CXXRecordDecl *Instance) {
2397  Pattern = Pattern->getCanonicalDecl();
2398
2399  do {
2400    Instance = Instance->getCanonicalDecl();
2401    if (Pattern == Instance) return true;
2402    Instance = Instance->getInstantiatedFromMemberClass();
2403  } while (Instance);
2404
2405  return false;
2406}
2407
2408static bool isInstantiationOf(FunctionDecl *Pattern,
2409                              FunctionDecl *Instance) {
2410  Pattern = Pattern->getCanonicalDecl();
2411
2412  do {
2413    Instance = Instance->getCanonicalDecl();
2414    if (Pattern == Instance) return true;
2415    Instance = Instance->getInstantiatedFromMemberFunction();
2416  } while (Instance);
2417
2418  return false;
2419}
2420
2421static bool isInstantiationOf(EnumDecl *Pattern,
2422                              EnumDecl *Instance) {
2423  Pattern = Pattern->getCanonicalDecl();
2424
2425  do {
2426    Instance = Instance->getCanonicalDecl();
2427    if (Pattern == Instance) return true;
2428    Instance = Instance->getInstantiatedFromMemberEnum();
2429  } while (Instance);
2430
2431  return false;
2432}
2433
2434static bool isInstantiationOf(UsingShadowDecl *Pattern,
2435                              UsingShadowDecl *Instance,
2436                              ASTContext &C) {
2437  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2438}
2439
2440static bool isInstantiationOf(UsingDecl *Pattern,
2441                              UsingDecl *Instance,
2442                              ASTContext &C) {
2443  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2444}
2445
2446static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2447                              UsingDecl *Instance,
2448                              ASTContext &C) {
2449  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2450}
2451
2452static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2453                              UsingDecl *Instance,
2454                              ASTContext &C) {
2455  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2456}
2457
2458static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2459                                              VarDecl *Instance) {
2460  assert(Instance->isStaticDataMember());
2461
2462  Pattern = Pattern->getCanonicalDecl();
2463
2464  do {
2465    Instance = Instance->getCanonicalDecl();
2466    if (Pattern == Instance) return true;
2467    Instance = Instance->getInstantiatedFromStaticDataMember();
2468  } while (Instance);
2469
2470  return false;
2471}
2472
2473// Other is the prospective instantiation
2474// D is the prospective pattern
2475static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2476  if (D->getKind() != Other->getKind()) {
2477    if (UnresolvedUsingTypenameDecl *UUD
2478          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2479      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2480        return isInstantiationOf(UUD, UD, Ctx);
2481      }
2482    }
2483
2484    if (UnresolvedUsingValueDecl *UUD
2485          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2486      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2487        return isInstantiationOf(UUD, UD, Ctx);
2488      }
2489    }
2490
2491    return false;
2492  }
2493
2494  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2495    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2496
2497  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2498    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2499
2500  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2501    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2502
2503  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2504    if (Var->isStaticDataMember())
2505      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2506
2507  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2508    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2509
2510  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2511    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2512
2513  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2514        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2515    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2516                             PartialSpec);
2517
2518  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2519    if (!Field->getDeclName()) {
2520      // This is an unnamed field.
2521      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2522        cast<FieldDecl>(D);
2523    }
2524  }
2525
2526  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2527    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2528
2529  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2530    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2531
2532  return D->getDeclName() && isa<NamedDecl>(Other) &&
2533    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2534}
2535
2536template<typename ForwardIterator>
2537static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2538                                      NamedDecl *D,
2539                                      ForwardIterator first,
2540                                      ForwardIterator last) {
2541  for (; first != last; ++first)
2542    if (isInstantiationOf(Ctx, D, *first))
2543      return cast<NamedDecl>(*first);
2544
2545  return 0;
2546}
2547
2548/// \brief Finds the instantiation of the given declaration context
2549/// within the current instantiation.
2550///
2551/// \returns NULL if there was an error
2552DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2553                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2554  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2555    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2556    return cast_or_null<DeclContext>(ID);
2557  } else return DC;
2558}
2559
2560/// \brief Find the instantiation of the given declaration within the
2561/// current instantiation.
2562///
2563/// This routine is intended to be used when \p D is a declaration
2564/// referenced from within a template, that needs to mapped into the
2565/// corresponding declaration within an instantiation. For example,
2566/// given:
2567///
2568/// \code
2569/// template<typename T>
2570/// struct X {
2571///   enum Kind {
2572///     KnownValue = sizeof(T)
2573///   };
2574///
2575///   bool getKind() const { return KnownValue; }
2576/// };
2577///
2578/// template struct X<int>;
2579/// \endcode
2580///
2581/// In the instantiation of X<int>::getKind(), we need to map the
2582/// EnumConstantDecl for KnownValue (which refers to
2583/// X<T>::<Kind>::KnownValue) to its instantiation
2584/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2585/// this mapping from within the instantiation of X<int>.
2586NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2587                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2588  DeclContext *ParentDC = D->getDeclContext();
2589  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2590      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2591      ParentDC->isFunctionOrMethod()) {
2592    // D is a local of some kind. Look into the map of local
2593    // declarations to their instantiations.
2594    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2595  }
2596
2597  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2598    if (!Record->isDependentContext())
2599      return D;
2600
2601    // If the RecordDecl is actually the injected-class-name or a
2602    // "templated" declaration for a class template, class template
2603    // partial specialization, or a member class of a class template,
2604    // substitute into the injected-class-name of the class template
2605    // or partial specialization to find the new DeclContext.
2606    QualType T;
2607    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2608
2609    if (ClassTemplate) {
2610      T = ClassTemplate->getInjectedClassNameSpecialization();
2611    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2612                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2613      ClassTemplate = PartialSpec->getSpecializedTemplate();
2614
2615      // If we call SubstType with an InjectedClassNameType here we
2616      // can end up in an infinite loop.
2617      T = Context.getTypeDeclType(Record);
2618      assert(isa<InjectedClassNameType>(T) &&
2619             "type of partial specialization is not an InjectedClassNameType");
2620      T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
2621    }
2622
2623    if (!T.isNull()) {
2624      // Substitute into the injected-class-name to get the type
2625      // corresponding to the instantiation we want, which may also be
2626      // the current instantiation (if we're in a template
2627      // definition). This substitution should never fail, since we
2628      // know we can instantiate the injected-class-name or we
2629      // wouldn't have gotten to the injected-class-name!
2630
2631      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2632      // extra instantiation in the common case?
2633      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2634      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2635
2636      if (!T->isDependentType()) {
2637        assert(T->isRecordType() && "Instantiation must produce a record type");
2638        return T->getAs<RecordType>()->getDecl();
2639      }
2640
2641      // We are performing "partial" template instantiation to create
2642      // the member declarations for the members of a class template
2643      // specialization. Therefore, D is actually referring to something
2644      // in the current instantiation. Look through the current
2645      // context, which contains actual instantiations, to find the
2646      // instantiation of the "current instantiation" that D refers
2647      // to.
2648      bool SawNonDependentContext = false;
2649      for (DeclContext *DC = CurContext; !DC->isFileContext();
2650           DC = DC->getParent()) {
2651        if (ClassTemplateSpecializationDecl *Spec
2652                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2653          if (isInstantiationOf(ClassTemplate,
2654                                Spec->getSpecializedTemplate()))
2655            return Spec;
2656
2657        if (!DC->isDependentContext())
2658          SawNonDependentContext = true;
2659      }
2660
2661      // We're performing "instantiation" of a member of the current
2662      // instantiation while we are type-checking the
2663      // definition. Compute the declaration context and return that.
2664      assert(!SawNonDependentContext &&
2665             "No dependent context while instantiating record");
2666      DeclContext *DC = computeDeclContext(T);
2667      assert(DC &&
2668             "Unable to find declaration for the current instantiation");
2669      return cast<CXXRecordDecl>(DC);
2670    }
2671
2672    // Fall through to deal with other dependent record types (e.g.,
2673    // anonymous unions in class templates).
2674  }
2675
2676  if (!ParentDC->isDependentContext())
2677    return D;
2678
2679  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2680  if (!ParentDC)
2681    return 0;
2682
2683  if (ParentDC != D->getDeclContext()) {
2684    // We performed some kind of instantiation in the parent context,
2685    // so now we need to look into the instantiated parent context to
2686    // find the instantiation of the declaration D.
2687
2688    // If our context used to be dependent, we may need to instantiate
2689    // it before performing lookup into that context.
2690    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2691      if (!Spec->isDependentContext()) {
2692        QualType T = Context.getTypeDeclType(Spec);
2693        const RecordType *Tag = T->getAs<RecordType>();
2694        assert(Tag && "type of non-dependent record is not a RecordType");
2695        if (!Tag->isBeingDefined() &&
2696            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2697          return 0;
2698      }
2699    }
2700
2701    NamedDecl *Result = 0;
2702    if (D->getDeclName()) {
2703      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2704      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2705    } else {
2706      // Since we don't have a name for the entity we're looking for,
2707      // our only option is to walk through all of the declarations to
2708      // find that name. This will occur in a few cases:
2709      //
2710      //   - anonymous struct/union within a template
2711      //   - unnamed class/struct/union/enum within a template
2712      //
2713      // FIXME: Find a better way to find these instantiations!
2714      Result = findInstantiationOf(Context, D,
2715                                   ParentDC->decls_begin(),
2716                                   ParentDC->decls_end());
2717    }
2718
2719    // UsingShadowDecls can instantiate to nothing because of using hiding.
2720    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2721            cast<Decl>(ParentDC)->isInvalidDecl())
2722           && "Unable to find instantiation of declaration!");
2723
2724    D = Result;
2725  }
2726
2727  return D;
2728}
2729
2730/// \brief Performs template instantiation for all implicit template
2731/// instantiations we have seen until this point.
2732void Sema::PerformPendingImplicitInstantiations(bool LocalOnly) {
2733  while (!PendingLocalImplicitInstantiations.empty() ||
2734         (!LocalOnly && !PendingImplicitInstantiations.empty())) {
2735    PendingImplicitInstantiation Inst;
2736
2737    if (PendingLocalImplicitInstantiations.empty()) {
2738      Inst = PendingImplicitInstantiations.front();
2739      PendingImplicitInstantiations.pop_front();
2740    } else {
2741      Inst = PendingLocalImplicitInstantiations.front();
2742      PendingLocalImplicitInstantiations.pop_front();
2743    }
2744
2745    // Instantiate function definitions
2746    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2747      PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Function),
2748                                            Function->getLocation(), *this,
2749                                            Context.getSourceManager(),
2750                                           "instantiating function definition");
2751
2752      InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true);
2753      continue;
2754    }
2755
2756    // Instantiate static data member definitions.
2757    VarDecl *Var = cast<VarDecl>(Inst.first);
2758    assert(Var->isStaticDataMember() && "Not a static data member?");
2759
2760    // Don't try to instantiate declarations if the most recent redeclaration
2761    // is invalid.
2762    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2763      continue;
2764
2765    // Check if the most recent declaration has changed the specialization kind
2766    // and removed the need for implicit instantiation.
2767    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2768    case TSK_Undeclared:
2769      assert(false && "Cannot instantitiate an undeclared specialization.");
2770    case TSK_ExplicitInstantiationDeclaration:
2771    case TSK_ExplicitInstantiationDefinition:
2772    case TSK_ExplicitSpecialization:
2773      continue;  // No longer need implicit instantiation.
2774    case TSK_ImplicitInstantiation:
2775      break;
2776    }
2777
2778    PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Var),
2779                                          Var->getLocation(), *this,
2780                                          Context.getSourceManager(),
2781                                          "instantiating static data member "
2782                                          "definition");
2783
2784    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true);
2785  }
2786}
2787
2788void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2789                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2790  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2791         E = Pattern->ddiag_end(); I != E; ++I) {
2792    DependentDiagnostic *DD = *I;
2793
2794    switch (DD->getKind()) {
2795    case DependentDiagnostic::Access:
2796      HandleDependentAccessCheck(*DD, TemplateArgs);
2797      break;
2798    }
2799  }
2800}
2801