SemaTemplateInstantiate.cpp revision 275313cbb0847f1f117f60d144d113804d4fa42d 
1//===------- SemaTemplateInstantiate.cpp - C++ Template 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.
10//
11//===----------------------------------------------------------------------===/
12
13#include "Sema.h"
14#include "TreeTransform.h"
15#include "Lookup.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/Expr.h"
19#include "clang/AST/DeclTemplate.h"
20#include "clang/Parse/DeclSpec.h"
21#include "clang/Basic/LangOptions.h"
22
23using namespace clang;
24
25//===----------------------------------------------------------------------===/
26// Template Instantiation Support
27//===----------------------------------------------------------------------===/
28
29/// \brief Retrieve the template argument list(s) that should be used to
30/// instantiate the definition of the given declaration.
31///
32/// \param D the declaration for which we are computing template instantiation
33/// arguments.
34///
35/// \param Innermost if non-NULL, the innermost template argument list.
36///
37/// \param RelativeToPrimary true if we should get the template
38/// arguments relative to the primary template, even when we're
39/// dealing with a specialization. This is only relevant for function
40/// template specializations.
41MultiLevelTemplateArgumentList
42Sema::getTemplateInstantiationArgs(NamedDecl *D,
43                                   const TemplateArgumentList *Innermost,
44                                   bool RelativeToPrimary) {
45  // Accumulate the set of template argument lists in this structure.
46  MultiLevelTemplateArgumentList Result;
47
48  if (Innermost)
49    Result.addOuterTemplateArguments(Innermost);
50
51  DeclContext *Ctx = dyn_cast<DeclContext>(D);
52  if (!Ctx)
53    Ctx = D->getDeclContext();
54
55  while (!Ctx->isFileContext()) {
56    // Add template arguments from a class template instantiation.
57    if (ClassTemplateSpecializationDecl *Spec
58          = dyn_cast<ClassTemplateSpecializationDecl>(Ctx)) {
59      // We're done when we hit an explicit specialization.
60      if (Spec->getSpecializationKind() == TSK_ExplicitSpecialization)
61        break;
62
63      Result.addOuterTemplateArguments(&Spec->getTemplateInstantiationArgs());
64
65      // If this class template specialization was instantiated from a
66      // specialized member that is a class template, we're done.
67      assert(Spec->getSpecializedTemplate() && "No class template?");
68      if (Spec->getSpecializedTemplate()->isMemberSpecialization())
69        break;
70    }
71    // Add template arguments from a function template specialization.
72    else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Ctx)) {
73      if (!RelativeToPrimary &&
74          Function->getTemplateSpecializationKind()
75                                                  == TSK_ExplicitSpecialization)
76        break;
77
78      if (const TemplateArgumentList *TemplateArgs
79            = Function->getTemplateSpecializationArgs()) {
80        // Add the template arguments for this specialization.
81        Result.addOuterTemplateArguments(TemplateArgs);
82
83        // If this function was instantiated from a specialized member that is
84        // a function template, we're done.
85        assert(Function->getPrimaryTemplate() && "No function template?");
86        if (Function->getPrimaryTemplate()->isMemberSpecialization())
87          break;
88      }
89
90      // If this is a friend declaration and it declares an entity at
91      // namespace scope, take arguments from its lexical parent
92      // instead of its semantic parent.
93      if (Function->getFriendObjectKind() &&
94          Function->getDeclContext()->isFileContext()) {
95        Ctx = Function->getLexicalDeclContext();
96        RelativeToPrimary = false;
97        continue;
98      }
99    }
100
101    Ctx = Ctx->getParent();
102    RelativeToPrimary = false;
103  }
104
105  return Result;
106}
107
108bool Sema::ActiveTemplateInstantiation::isInstantiationRecord() const {
109  switch (Kind) {
110  case TemplateInstantiation:
111  case DefaultTemplateArgumentInstantiation:
112  case DefaultFunctionArgumentInstantiation:
113    return true;
114
115  case ExplicitTemplateArgumentSubstitution:
116  case DeducedTemplateArgumentSubstitution:
117  case PriorTemplateArgumentSubstitution:
118  case DefaultTemplateArgumentChecking:
119    return false;
120  }
121
122  return true;
123}
124
125Sema::InstantiatingTemplate::
126InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
127                      Decl *Entity,
128                      SourceRange InstantiationRange)
129  :  SemaRef(SemaRef) {
130
131  Invalid = CheckInstantiationDepth(PointOfInstantiation,
132                                    InstantiationRange);
133  if (!Invalid) {
134    ActiveTemplateInstantiation Inst;
135    Inst.Kind = ActiveTemplateInstantiation::TemplateInstantiation;
136    Inst.PointOfInstantiation = PointOfInstantiation;
137    Inst.Entity = reinterpret_cast<uintptr_t>(Entity);
138    Inst.TemplateArgs = 0;
139    Inst.NumTemplateArgs = 0;
140    Inst.InstantiationRange = InstantiationRange;
141    SemaRef.ActiveTemplateInstantiations.push_back(Inst);
142  }
143}
144
145Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef,
146                                         SourceLocation PointOfInstantiation,
147                                         TemplateDecl *Template,
148                                         const TemplateArgument *TemplateArgs,
149                                         unsigned NumTemplateArgs,
150                                         SourceRange InstantiationRange)
151  : SemaRef(SemaRef) {
152
153  Invalid = CheckInstantiationDepth(PointOfInstantiation,
154                                    InstantiationRange);
155  if (!Invalid) {
156    ActiveTemplateInstantiation Inst;
157    Inst.Kind
158      = ActiveTemplateInstantiation::DefaultTemplateArgumentInstantiation;
159    Inst.PointOfInstantiation = PointOfInstantiation;
160    Inst.Entity = reinterpret_cast<uintptr_t>(Template);
161    Inst.TemplateArgs = TemplateArgs;
162    Inst.NumTemplateArgs = NumTemplateArgs;
163    Inst.InstantiationRange = InstantiationRange;
164    SemaRef.ActiveTemplateInstantiations.push_back(Inst);
165  }
166}
167
168Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef,
169                                         SourceLocation PointOfInstantiation,
170                                      FunctionTemplateDecl *FunctionTemplate,
171                                        const TemplateArgument *TemplateArgs,
172                                                   unsigned NumTemplateArgs,
173                         ActiveTemplateInstantiation::InstantiationKind Kind,
174                                              SourceRange InstantiationRange)
175: SemaRef(SemaRef) {
176
177  Invalid = CheckInstantiationDepth(PointOfInstantiation,
178                                    InstantiationRange);
179  if (!Invalid) {
180    ActiveTemplateInstantiation Inst;
181    Inst.Kind = Kind;
182    Inst.PointOfInstantiation = PointOfInstantiation;
183    Inst.Entity = reinterpret_cast<uintptr_t>(FunctionTemplate);
184    Inst.TemplateArgs = TemplateArgs;
185    Inst.NumTemplateArgs = NumTemplateArgs;
186    Inst.InstantiationRange = InstantiationRange;
187    SemaRef.ActiveTemplateInstantiations.push_back(Inst);
188
189    if (!Inst.isInstantiationRecord())
190      ++SemaRef.NonInstantiationEntries;
191  }
192}
193
194Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef,
195                                         SourceLocation PointOfInstantiation,
196                          ClassTemplatePartialSpecializationDecl *PartialSpec,
197                                         const TemplateArgument *TemplateArgs,
198                                         unsigned NumTemplateArgs,
199                                         SourceRange InstantiationRange)
200  : SemaRef(SemaRef) {
201
202  Invalid = false;
203
204  ActiveTemplateInstantiation Inst;
205  Inst.Kind = ActiveTemplateInstantiation::DeducedTemplateArgumentSubstitution;
206  Inst.PointOfInstantiation = PointOfInstantiation;
207  Inst.Entity = reinterpret_cast<uintptr_t>(PartialSpec);
208  Inst.TemplateArgs = TemplateArgs;
209  Inst.NumTemplateArgs = NumTemplateArgs;
210  Inst.InstantiationRange = InstantiationRange;
211  SemaRef.ActiveTemplateInstantiations.push_back(Inst);
212
213  assert(!Inst.isInstantiationRecord());
214  ++SemaRef.NonInstantiationEntries;
215}
216
217Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef,
218                                          SourceLocation PointOfInstantiation,
219                                          ParmVarDecl *Param,
220                                          const TemplateArgument *TemplateArgs,
221                                          unsigned NumTemplateArgs,
222                                          SourceRange InstantiationRange)
223  : SemaRef(SemaRef) {
224
225  Invalid = CheckInstantiationDepth(PointOfInstantiation, InstantiationRange);
226
227  if (!Invalid) {
228    ActiveTemplateInstantiation Inst;
229    Inst.Kind
230      = ActiveTemplateInstantiation::DefaultFunctionArgumentInstantiation;
231    Inst.PointOfInstantiation = PointOfInstantiation;
232    Inst.Entity = reinterpret_cast<uintptr_t>(Param);
233    Inst.TemplateArgs = TemplateArgs;
234    Inst.NumTemplateArgs = NumTemplateArgs;
235    Inst.InstantiationRange = InstantiationRange;
236    SemaRef.ActiveTemplateInstantiations.push_back(Inst);
237  }
238}
239
240Sema::InstantiatingTemplate::
241InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
242                      TemplateDecl *Template,
243                      NonTypeTemplateParmDecl *Param,
244                      const TemplateArgument *TemplateArgs,
245                      unsigned NumTemplateArgs,
246                      SourceRange InstantiationRange) : SemaRef(SemaRef) {
247  Invalid = false;
248
249  ActiveTemplateInstantiation Inst;
250  Inst.Kind = ActiveTemplateInstantiation::PriorTemplateArgumentSubstitution;
251  Inst.PointOfInstantiation = PointOfInstantiation;
252  Inst.Template = Template;
253  Inst.Entity = reinterpret_cast<uintptr_t>(Param);
254  Inst.TemplateArgs = TemplateArgs;
255  Inst.NumTemplateArgs = NumTemplateArgs;
256  Inst.InstantiationRange = InstantiationRange;
257  SemaRef.ActiveTemplateInstantiations.push_back(Inst);
258
259  assert(!Inst.isInstantiationRecord());
260  ++SemaRef.NonInstantiationEntries;
261}
262
263Sema::InstantiatingTemplate::
264InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
265                      TemplateDecl *Template,
266                      TemplateTemplateParmDecl *Param,
267                      const TemplateArgument *TemplateArgs,
268                      unsigned NumTemplateArgs,
269                      SourceRange InstantiationRange) : SemaRef(SemaRef) {
270  Invalid = false;
271  ActiveTemplateInstantiation Inst;
272  Inst.Kind = ActiveTemplateInstantiation::PriorTemplateArgumentSubstitution;
273  Inst.PointOfInstantiation = PointOfInstantiation;
274  Inst.Template = Template;
275  Inst.Entity = reinterpret_cast<uintptr_t>(Param);
276  Inst.TemplateArgs = TemplateArgs;
277  Inst.NumTemplateArgs = NumTemplateArgs;
278  Inst.InstantiationRange = InstantiationRange;
279  SemaRef.ActiveTemplateInstantiations.push_back(Inst);
280
281  assert(!Inst.isInstantiationRecord());
282  ++SemaRef.NonInstantiationEntries;
283}
284
285Sema::InstantiatingTemplate::
286InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
287                      TemplateDecl *Template,
288                      NamedDecl *Param,
289                      const TemplateArgument *TemplateArgs,
290                      unsigned NumTemplateArgs,
291                      SourceRange InstantiationRange) : SemaRef(SemaRef) {
292  Invalid = false;
293
294  ActiveTemplateInstantiation Inst;
295  Inst.Kind = ActiveTemplateInstantiation::DefaultTemplateArgumentChecking;
296  Inst.PointOfInstantiation = PointOfInstantiation;
297  Inst.Template = Template;
298  Inst.Entity = reinterpret_cast<uintptr_t>(Param);
299  Inst.TemplateArgs = TemplateArgs;
300  Inst.NumTemplateArgs = NumTemplateArgs;
301  Inst.InstantiationRange = InstantiationRange;
302  SemaRef.ActiveTemplateInstantiations.push_back(Inst);
303
304  assert(!Inst.isInstantiationRecord());
305  ++SemaRef.NonInstantiationEntries;
306}
307
308void Sema::InstantiatingTemplate::Clear() {
309  if (!Invalid) {
310    if (!SemaRef.ActiveTemplateInstantiations.back().isInstantiationRecord()) {
311      assert(SemaRef.NonInstantiationEntries > 0);
312      --SemaRef.NonInstantiationEntries;
313    }
314
315    SemaRef.ActiveTemplateInstantiations.pop_back();
316    Invalid = true;
317  }
318}
319
320bool Sema::InstantiatingTemplate::CheckInstantiationDepth(
321                                        SourceLocation PointOfInstantiation,
322                                           SourceRange InstantiationRange) {
323  assert(SemaRef.NonInstantiationEntries <=
324                                   SemaRef.ActiveTemplateInstantiations.size());
325  if ((SemaRef.ActiveTemplateInstantiations.size() -
326          SemaRef.NonInstantiationEntries)
327        <= SemaRef.getLangOptions().InstantiationDepth)
328    return false;
329
330  SemaRef.Diag(PointOfInstantiation,
331               diag::err_template_recursion_depth_exceeded)
332    << SemaRef.getLangOptions().InstantiationDepth
333    << InstantiationRange;
334  SemaRef.Diag(PointOfInstantiation, diag::note_template_recursion_depth)
335    << SemaRef.getLangOptions().InstantiationDepth;
336  return true;
337}
338
339/// \brief Prints the current instantiation stack through a series of
340/// notes.
341void Sema::PrintInstantiationStack() {
342  // FIXME: In all of these cases, we need to show the template arguments
343  for (llvm::SmallVector<ActiveTemplateInstantiation, 16>::reverse_iterator
344         Active = ActiveTemplateInstantiations.rbegin(),
345         ActiveEnd = ActiveTemplateInstantiations.rend();
346       Active != ActiveEnd;
347       ++Active) {
348    switch (Active->Kind) {
349    case ActiveTemplateInstantiation::TemplateInstantiation: {
350      Decl *D = reinterpret_cast<Decl *>(Active->Entity);
351      if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
352        unsigned DiagID = diag::note_template_member_class_here;
353        if (isa<ClassTemplateSpecializationDecl>(Record))
354          DiagID = diag::note_template_class_instantiation_here;
355        Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
356                     DiagID)
357          << Context.getTypeDeclType(Record)
358          << Active->InstantiationRange;
359      } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) {
360        unsigned DiagID;
361        if (Function->getPrimaryTemplate())
362          DiagID = diag::note_function_template_spec_here;
363        else
364          DiagID = diag::note_template_member_function_here;
365        Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
366                     DiagID)
367          << Function
368          << Active->InstantiationRange;
369      } else {
370        Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
371                     diag::note_template_static_data_member_def_here)
372          << cast<VarDecl>(D)
373          << Active->InstantiationRange;
374      }
375      break;
376    }
377
378    case ActiveTemplateInstantiation::DefaultTemplateArgumentInstantiation: {
379      TemplateDecl *Template = cast<TemplateDecl>((Decl *)Active->Entity);
380      std::string TemplateArgsStr
381        = TemplateSpecializationType::PrintTemplateArgumentList(
382                                                         Active->TemplateArgs,
383                                                      Active->NumTemplateArgs,
384                                                      Context.PrintingPolicy);
385      Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
386                   diag::note_default_arg_instantiation_here)
387        << (Template->getNameAsString() + TemplateArgsStr)
388        << Active->InstantiationRange;
389      break;
390    }
391
392    case ActiveTemplateInstantiation::ExplicitTemplateArgumentSubstitution: {
393      FunctionTemplateDecl *FnTmpl
394        = cast<FunctionTemplateDecl>((Decl *)Active->Entity);
395      Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
396                   diag::note_explicit_template_arg_substitution_here)
397        << FnTmpl
398        << getTemplateArgumentBindingsText(FnTmpl->getTemplateParameters(),
399                                           Active->TemplateArgs,
400                                           Active->NumTemplateArgs)
401        << Active->InstantiationRange;
402      break;
403    }
404
405    case ActiveTemplateInstantiation::DeducedTemplateArgumentSubstitution:
406      if (ClassTemplatePartialSpecializationDecl *PartialSpec
407            = dyn_cast<ClassTemplatePartialSpecializationDecl>(
408                                                    (Decl *)Active->Entity)) {
409        Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
410                     diag::note_partial_spec_deduct_instantiation_here)
411          << Context.getTypeDeclType(PartialSpec)
412          << getTemplateArgumentBindingsText(
413                                         PartialSpec->getTemplateParameters(),
414                                             Active->TemplateArgs,
415                                             Active->NumTemplateArgs)
416          << Active->InstantiationRange;
417      } else {
418        FunctionTemplateDecl *FnTmpl
419          = cast<FunctionTemplateDecl>((Decl *)Active->Entity);
420        Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
421                     diag::note_function_template_deduction_instantiation_here)
422          << FnTmpl
423          << getTemplateArgumentBindingsText(FnTmpl->getTemplateParameters(),
424                                             Active->TemplateArgs,
425                                             Active->NumTemplateArgs)
426          << Active->InstantiationRange;
427      }
428      break;
429
430    case ActiveTemplateInstantiation::DefaultFunctionArgumentInstantiation: {
431      ParmVarDecl *Param = cast<ParmVarDecl>((Decl *)Active->Entity);
432      FunctionDecl *FD = cast<FunctionDecl>(Param->getDeclContext());
433
434      std::string TemplateArgsStr
435        = TemplateSpecializationType::PrintTemplateArgumentList(
436                                                         Active->TemplateArgs,
437                                                      Active->NumTemplateArgs,
438                                                      Context.PrintingPolicy);
439      Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
440                   diag::note_default_function_arg_instantiation_here)
441        << (FD->getNameAsString() + TemplateArgsStr)
442        << Active->InstantiationRange;
443      break;
444    }
445
446    case ActiveTemplateInstantiation::PriorTemplateArgumentSubstitution: {
447      NamedDecl *Parm = cast<NamedDecl>((Decl *)Active->Entity);
448      std::string Name;
449      if (!Parm->getName().empty())
450        Name = std::string(" '") + Parm->getName().str() + "'";
451
452      Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
453                   diag::note_prior_template_arg_substitution)
454        << isa<TemplateTemplateParmDecl>(Parm)
455        << Name
456        << getTemplateArgumentBindingsText(
457                                    Active->Template->getTemplateParameters(),
458                                           Active->TemplateArgs,
459                                           Active->NumTemplateArgs)
460        << Active->InstantiationRange;
461      break;
462    }
463
464    case ActiveTemplateInstantiation::DefaultTemplateArgumentChecking: {
465      Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
466                   diag::note_template_default_arg_checking)
467        << getTemplateArgumentBindingsText(
468                                     Active->Template->getTemplateParameters(),
469                                           Active->TemplateArgs,
470                                           Active->NumTemplateArgs)
471        << Active->InstantiationRange;
472      break;
473    }
474    }
475  }
476}
477
478bool Sema::isSFINAEContext() const {
479  using llvm::SmallVector;
480  for (SmallVector<ActiveTemplateInstantiation, 16>::const_reverse_iterator
481         Active = ActiveTemplateInstantiations.rbegin(),
482         ActiveEnd = ActiveTemplateInstantiations.rend();
483       Active != ActiveEnd;
484       ++Active)
485  {
486    switch(Active->Kind) {
487    case ActiveTemplateInstantiation::TemplateInstantiation:
488    case ActiveTemplateInstantiation::DefaultFunctionArgumentInstantiation:
489      // This is a template instantiation, so there is no SFINAE.
490      return false;
491
492    case ActiveTemplateInstantiation::DefaultTemplateArgumentInstantiation:
493    case ActiveTemplateInstantiation::PriorTemplateArgumentSubstitution:
494    case ActiveTemplateInstantiation::DefaultTemplateArgumentChecking:
495      // A default template argument instantiation and substitution into
496      // template parameters with arguments for prior parameters may or may
497      // not be a SFINAE context; look further up the stack.
498      break;
499
500    case ActiveTemplateInstantiation::ExplicitTemplateArgumentSubstitution:
501    case ActiveTemplateInstantiation::DeducedTemplateArgumentSubstitution:
502      // We're either substitution explicitly-specified template arguments
503      // or deduced template arguments, so SFINAE applies.
504      return true;
505    }
506  }
507
508  return false;
509}
510
511//===----------------------------------------------------------------------===/
512// Template Instantiation for Types
513//===----------------------------------------------------------------------===/
514namespace {
515  class TemplateInstantiator
516    : public TreeTransform<TemplateInstantiator> {
517    const MultiLevelTemplateArgumentList &TemplateArgs;
518    SourceLocation Loc;
519    DeclarationName Entity;
520
521  public:
522    typedef TreeTransform<TemplateInstantiator> inherited;
523
524    TemplateInstantiator(Sema &SemaRef,
525                         const MultiLevelTemplateArgumentList &TemplateArgs,
526                         SourceLocation Loc,
527                         DeclarationName Entity)
528      : inherited(SemaRef), TemplateArgs(TemplateArgs), Loc(Loc),
529        Entity(Entity) { }
530
531    /// \brief Determine whether the given type \p T has already been
532    /// transformed.
533    ///
534    /// For the purposes of template instantiation, a type has already been
535    /// transformed if it is NULL or if it is not dependent.
536    bool AlreadyTransformed(QualType T) {
537      return T.isNull() || !T->isDependentType();
538    }
539
540    /// \brief Returns the location of the entity being instantiated, if known.
541    SourceLocation getBaseLocation() { return Loc; }
542
543    /// \brief Returns the name of the entity being instantiated, if any.
544    DeclarationName getBaseEntity() { return Entity; }
545
546    /// \brief Sets the "base" location and entity when that
547    /// information is known based on another transformation.
548    void setBase(SourceLocation Loc, DeclarationName Entity) {
549      this->Loc = Loc;
550      this->Entity = Entity;
551    }
552
553    /// \brief Transform the given declaration by instantiating a reference to
554    /// this declaration.
555    Decl *TransformDecl(SourceLocation Loc, Decl *D);
556
557    /// \brief Transform the definition of the given declaration by
558    /// instantiating it.
559    Decl *TransformDefinition(SourceLocation Loc, Decl *D);
560
561    /// \bried Transform the first qualifier within a scope by instantiating the
562    /// declaration.
563    NamedDecl *TransformFirstQualifierInScope(NamedDecl *D, SourceLocation Loc);
564
565    /// \brief Rebuild the exception declaration and register the declaration
566    /// as an instantiated local.
567    VarDecl *RebuildExceptionDecl(VarDecl *ExceptionDecl, QualType T,
568                                  TypeSourceInfo *Declarator,
569                                  IdentifierInfo *Name,
570                                  SourceLocation Loc, SourceRange TypeRange);
571
572    /// \brief Check for tag mismatches when instantiating an
573    /// elaborated type.
574    QualType RebuildElaboratedType(QualType T, ElaboratedType::TagKind Tag);
575
576    Sema::OwningExprResult TransformPredefinedExpr(PredefinedExpr *E);
577    Sema::OwningExprResult TransformDeclRefExpr(DeclRefExpr *E);
578    Sema::OwningExprResult TransformCXXDefaultArgExpr(CXXDefaultArgExpr *E);
579    Sema::OwningExprResult TransformTemplateParmRefExpr(DeclRefExpr *E,
580                                                NonTypeTemplateParmDecl *D);
581
582    /// \brief Transforms a function proto type by performing
583    /// substitution in the function parameters, possibly adjusting
584    /// their types and marking default arguments as uninstantiated.
585    bool TransformFunctionTypeParams(FunctionProtoTypeLoc TL,
586                                     llvm::SmallVectorImpl<QualType> &PTypes,
587                                  llvm::SmallVectorImpl<ParmVarDecl*> &PVars);
588
589    ParmVarDecl *TransformFunctionTypeParam(ParmVarDecl *OldParm);
590
591    /// \brief Transforms a template type parameter type by performing
592    /// substitution of the corresponding template type argument.
593    QualType TransformTemplateTypeParmType(TypeLocBuilder &TLB,
594                                           TemplateTypeParmTypeLoc TL,
595                                           QualType ObjectType);
596  };
597}
598
599Decl *TemplateInstantiator::TransformDecl(SourceLocation Loc, Decl *D) {
600  if (!D)
601    return 0;
602
603  if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(D)) {
604    if (TTP->getDepth() < TemplateArgs.getNumLevels()) {
605      // If the corresponding template argument is NULL or non-existent, it's
606      // because we are performing instantiation from explicitly-specified
607      // template arguments in a function template, but there were some
608      // arguments left unspecified.
609      if (!TemplateArgs.hasTemplateArgument(TTP->getDepth(),
610                                            TTP->getPosition()))
611        return D;
612
613      TemplateName Template
614        = TemplateArgs(TTP->getDepth(), TTP->getPosition()).getAsTemplate();
615      assert(!Template.isNull() && Template.getAsTemplateDecl() &&
616             "Wrong kind of template template argument");
617      return Template.getAsTemplateDecl();
618    }
619
620    // Fall through to find the instantiated declaration for this template
621    // template parameter.
622  }
623
624  return SemaRef.FindInstantiatedDecl(Loc, cast<NamedDecl>(D), TemplateArgs);
625}
626
627Decl *TemplateInstantiator::TransformDefinition(SourceLocation Loc, Decl *D) {
628  Decl *Inst = getSema().SubstDecl(D, getSema().CurContext, TemplateArgs);
629  if (!Inst)
630    return 0;
631
632  getSema().CurrentInstantiationScope->InstantiatedLocal(D, Inst);
633  return Inst;
634}
635
636NamedDecl *
637TemplateInstantiator::TransformFirstQualifierInScope(NamedDecl *D,
638                                                     SourceLocation Loc) {
639  // If the first part of the nested-name-specifier was a template type
640  // parameter, instantiate that type parameter down to a tag type.
641  if (TemplateTypeParmDecl *TTPD = dyn_cast_or_null<TemplateTypeParmDecl>(D)) {
642    const TemplateTypeParmType *TTP
643      = cast<TemplateTypeParmType>(getSema().Context.getTypeDeclType(TTPD));
644    if (TTP->getDepth() < TemplateArgs.getNumLevels()) {
645      QualType T = TemplateArgs(TTP->getDepth(), TTP->getIndex()).getAsType();
646      if (T.isNull())
647        return cast_or_null<NamedDecl>(TransformDecl(Loc, D));
648
649      if (const TagType *Tag = T->getAs<TagType>())
650        return Tag->getDecl();
651
652      // The resulting type is not a tag; complain.
653      getSema().Diag(Loc, diag::err_nested_name_spec_non_tag) << T;
654      return 0;
655    }
656  }
657
658  return cast_or_null<NamedDecl>(TransformDecl(Loc, D));
659}
660
661VarDecl *
662TemplateInstantiator::RebuildExceptionDecl(VarDecl *ExceptionDecl,
663                                           QualType T,
664                                           TypeSourceInfo *Declarator,
665                                           IdentifierInfo *Name,
666                                           SourceLocation Loc,
667                                           SourceRange TypeRange) {
668  VarDecl *Var = inherited::RebuildExceptionDecl(ExceptionDecl, T, Declarator,
669                                                 Name, Loc, TypeRange);
670  if (Var && !Var->isInvalidDecl())
671    getSema().CurrentInstantiationScope->InstantiatedLocal(ExceptionDecl, Var);
672  return Var;
673}
674
675QualType
676TemplateInstantiator::RebuildElaboratedType(QualType T,
677                                            ElaboratedType::TagKind Tag) {
678  if (const TagType *TT = T->getAs<TagType>()) {
679    TagDecl* TD = TT->getDecl();
680
681    // FIXME: this location is very wrong;  we really need typelocs.
682    SourceLocation TagLocation = TD->getTagKeywordLoc();
683
684    // FIXME: type might be anonymous.
685    IdentifierInfo *Id = TD->getIdentifier();
686
687    // TODO: should we even warn on struct/class mismatches for this?  Seems
688    // like it's likely to produce a lot of spurious errors.
689    if (!SemaRef.isAcceptableTagRedeclaration(TD, Tag, TagLocation, *Id)) {
690      SemaRef.Diag(TagLocation, diag::err_use_with_wrong_tag)
691        << Id
692        << CodeModificationHint::CreateReplacement(SourceRange(TagLocation),
693                                                   TD->getKindName());
694      SemaRef.Diag(TD->getLocation(), diag::note_previous_use);
695    }
696  }
697
698  return TreeTransform<TemplateInstantiator>::RebuildElaboratedType(T, Tag);
699}
700
701Sema::OwningExprResult
702TemplateInstantiator::TransformPredefinedExpr(PredefinedExpr *E) {
703  if (!E->isTypeDependent())
704    return SemaRef.Owned(E->Retain());
705
706  FunctionDecl *currentDecl = getSema().getCurFunctionDecl();
707  assert(currentDecl && "Must have current function declaration when "
708                        "instantiating.");
709
710  PredefinedExpr::IdentType IT = E->getIdentType();
711
712  unsigned Length = PredefinedExpr::ComputeName(IT, currentDecl).length();
713
714  llvm::APInt LengthI(32, Length + 1);
715  QualType ResTy = getSema().Context.CharTy.withConst();
716  ResTy = getSema().Context.getConstantArrayType(ResTy, LengthI,
717                                                 ArrayType::Normal, 0);
718  PredefinedExpr *PE =
719    new (getSema().Context) PredefinedExpr(E->getLocation(), ResTy, IT);
720  return getSema().Owned(PE);
721}
722
723Sema::OwningExprResult
724TemplateInstantiator::TransformTemplateParmRefExpr(DeclRefExpr *E,
725                                               NonTypeTemplateParmDecl *NTTP) {
726  // If the corresponding template argument is NULL or non-existent, it's
727  // because we are performing instantiation from explicitly-specified
728  // template arguments in a function template, but there were some
729  // arguments left unspecified.
730  if (!TemplateArgs.hasTemplateArgument(NTTP->getDepth(),
731                                        NTTP->getPosition()))
732    return SemaRef.Owned(E->Retain());
733
734  const TemplateArgument &Arg = TemplateArgs(NTTP->getDepth(),
735                                             NTTP->getPosition());
736
737  // The template argument itself might be an expression, in which
738  // case we just return that expression.
739  if (Arg.getKind() == TemplateArgument::Expression)
740    return SemaRef.Owned(Arg.getAsExpr()->Retain());
741
742  if (Arg.getKind() == TemplateArgument::Declaration) {
743    ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl());
744
745    // Find the instantiation of the template argument.  This is
746    // required for nested templates.
747    VD = cast_or_null<ValueDecl>(
748                            getSema().FindInstantiatedDecl(E->getLocation(),
749                                                           VD, TemplateArgs));
750    if (!VD)
751      return SemaRef.ExprError();
752
753    // Derive the type we want the substituted decl to have.  This had
754    // better be non-dependent, or these checks will have serious problems.
755    QualType TargetType = SemaRef.SubstType(NTTP->getType(), TemplateArgs,
756                                            E->getLocation(),
757                                            DeclarationName());
758    assert(!TargetType.isNull() && "type substitution failed for param type");
759    assert(!TargetType->isDependentType() && "param type still dependent");
760    return SemaRef.BuildExpressionFromDeclTemplateArgument(Arg,
761                                                           TargetType,
762                                                           E->getLocation());
763  }
764
765  return SemaRef.BuildExpressionFromIntegralTemplateArgument(Arg,
766                                                E->getSourceRange().getBegin());
767}
768
769
770Sema::OwningExprResult
771TemplateInstantiator::TransformDeclRefExpr(DeclRefExpr *E) {
772  NamedDecl *D = E->getDecl();
773  if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(D)) {
774    if (NTTP->getDepth() < TemplateArgs.getNumLevels())
775      return TransformTemplateParmRefExpr(E, NTTP);
776
777    // We have a non-type template parameter that isn't fully substituted;
778    // FindInstantiatedDecl will find it in the local instantiation scope.
779  }
780
781  return TreeTransform<TemplateInstantiator>::TransformDeclRefExpr(E);
782}
783
784Sema::OwningExprResult TemplateInstantiator::TransformCXXDefaultArgExpr(
785    CXXDefaultArgExpr *E) {
786  assert(!cast<FunctionDecl>(E->getParam()->getDeclContext())->
787             getDescribedFunctionTemplate() &&
788         "Default arg expressions are never formed in dependent cases.");
789  return SemaRef.BuildCXXDefaultArgExpr(E->getUsedLocation(),
790                           cast<FunctionDecl>(E->getParam()->getDeclContext()),
791                                        E->getParam());
792}
793
794
795bool
796TemplateInstantiator::TransformFunctionTypeParams(FunctionProtoTypeLoc TL,
797                                  llvm::SmallVectorImpl<QualType> &PTypes,
798                               llvm::SmallVectorImpl<ParmVarDecl*> &PVars) {
799  // Create a local instantiation scope for the parameters.
800  // FIXME: When we implement the C++0x late-specified return type,
801  // we will need to move this scope out to the function type itself.
802  bool IsTemporaryScope = (SemaRef.CurrentInstantiationScope != 0);
803  Sema::LocalInstantiationScope Scope(SemaRef, IsTemporaryScope,
804                                      IsTemporaryScope);
805
806  if (TreeTransform<TemplateInstantiator>::
807        TransformFunctionTypeParams(TL, PTypes, PVars))
808    return true;
809
810  // Check instantiated parameters.
811  if (SemaRef.CheckInstantiatedParams(PVars))
812    return true;
813
814  return false;
815}
816
817ParmVarDecl *
818TemplateInstantiator::TransformFunctionTypeParam(ParmVarDecl *OldParm) {
819  TypeSourceInfo *OldDI = OldParm->getTypeSourceInfo();
820  TypeSourceInfo *NewDI = getDerived().TransformType(OldDI);
821  if (!NewDI)
822    return 0;
823
824  // TODO: do we have to clone this decl if the types match and
825  // there's no default argument?
826
827  ParmVarDecl *NewParm
828    = ParmVarDecl::Create(SemaRef.Context,
829                          OldParm->getDeclContext(),
830                          OldParm->getLocation(),
831                          OldParm->getIdentifier(),
832                          NewDI->getType(),
833                          NewDI,
834                          OldParm->getStorageClass(),
835                          /* DefArg */ NULL);
836
837  // Maybe adjust new parameter type.
838  NewParm->setType(SemaRef.adjustParameterType(NewParm->getType()));
839
840  // Mark the (new) default argument as uninstantiated (if any).
841  if (OldParm->hasUninstantiatedDefaultArg()) {
842    Expr *Arg = OldParm->getUninstantiatedDefaultArg();
843    NewParm->setUninstantiatedDefaultArg(Arg);
844  } else if (Expr *Arg = OldParm->getDefaultArg())
845    NewParm->setUninstantiatedDefaultArg(Arg);
846
847  NewParm->setHasInheritedDefaultArg(OldParm->hasInheritedDefaultArg());
848
849  SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldParm, NewParm);
850  return NewParm;
851}
852
853QualType
854TemplateInstantiator::TransformTemplateTypeParmType(TypeLocBuilder &TLB,
855                                                TemplateTypeParmTypeLoc TL,
856                                                    QualType ObjectType) {
857  TemplateTypeParmType *T = TL.getTypePtr();
858  if (T->getDepth() < TemplateArgs.getNumLevels()) {
859    // Replace the template type parameter with its corresponding
860    // template argument.
861
862    // If the corresponding template argument is NULL or doesn't exist, it's
863    // because we are performing instantiation from explicitly-specified
864    // template arguments in a function template class, but there were some
865    // arguments left unspecified.
866    if (!TemplateArgs.hasTemplateArgument(T->getDepth(), T->getIndex())) {
867      TemplateTypeParmTypeLoc NewTL
868        = TLB.push<TemplateTypeParmTypeLoc>(TL.getType());
869      NewTL.setNameLoc(TL.getNameLoc());
870      return TL.getType();
871    }
872
873    assert(TemplateArgs(T->getDepth(), T->getIndex()).getKind()
874             == TemplateArgument::Type &&
875           "Template argument kind mismatch");
876
877    QualType Replacement
878      = TemplateArgs(T->getDepth(), T->getIndex()).getAsType();
879
880    // TODO: only do this uniquing once, at the start of instantiation.
881    QualType Result
882      = getSema().Context.getSubstTemplateTypeParmType(T, Replacement);
883    SubstTemplateTypeParmTypeLoc NewTL
884      = TLB.push<SubstTemplateTypeParmTypeLoc>(Result);
885    NewTL.setNameLoc(TL.getNameLoc());
886    return Result;
887  }
888
889  // The template type parameter comes from an inner template (e.g.,
890  // the template parameter list of a member template inside the
891  // template we are instantiating). Create a new template type
892  // parameter with the template "level" reduced by one.
893  QualType Result
894    = getSema().Context.getTemplateTypeParmType(T->getDepth()
895                                                 - TemplateArgs.getNumLevels(),
896                                                T->getIndex(),
897                                                T->isParameterPack(),
898                                                T->getName());
899  TemplateTypeParmTypeLoc NewTL = TLB.push<TemplateTypeParmTypeLoc>(Result);
900  NewTL.setNameLoc(TL.getNameLoc());
901  return Result;
902}
903
904/// \brief Perform substitution on the type T with a given set of template
905/// arguments.
906///
907/// This routine substitutes the given template arguments into the
908/// type T and produces the instantiated type.
909///
910/// \param T the type into which the template arguments will be
911/// substituted. If this type is not dependent, it will be returned
912/// immediately.
913///
914/// \param TemplateArgs the template arguments that will be
915/// substituted for the top-level template parameters within T.
916///
917/// \param Loc the location in the source code where this substitution
918/// is being performed. It will typically be the location of the
919/// declarator (if we're instantiating the type of some declaration)
920/// or the location of the type in the source code (if, e.g., we're
921/// instantiating the type of a cast expression).
922///
923/// \param Entity the name of the entity associated with a declaration
924/// being instantiated (if any). May be empty to indicate that there
925/// is no such entity (if, e.g., this is a type that occurs as part of
926/// a cast expression) or that the entity has no name (e.g., an
927/// unnamed function parameter).
928///
929/// \returns If the instantiation succeeds, the instantiated
930/// type. Otherwise, produces diagnostics and returns a NULL type.
931TypeSourceInfo *Sema::SubstType(TypeSourceInfo *T,
932                                const MultiLevelTemplateArgumentList &Args,
933                                SourceLocation Loc,
934                                DeclarationName Entity) {
935  assert(!ActiveTemplateInstantiations.empty() &&
936         "Cannot perform an instantiation without some context on the "
937         "instantiation stack");
938
939  if (!T->getType()->isDependentType())
940    return T;
941
942  TemplateInstantiator Instantiator(*this, Args, Loc, Entity);
943  return Instantiator.TransformType(T);
944}
945
946/// Deprecated form of the above.
947QualType Sema::SubstType(QualType T,
948                         const MultiLevelTemplateArgumentList &TemplateArgs,
949                         SourceLocation Loc, DeclarationName Entity) {
950  assert(!ActiveTemplateInstantiations.empty() &&
951         "Cannot perform an instantiation without some context on the "
952         "instantiation stack");
953
954  // If T is not a dependent type, there is nothing to do.
955  if (!T->isDependentType())
956    return T;
957
958  TemplateInstantiator Instantiator(*this, TemplateArgs, Loc, Entity);
959  return Instantiator.TransformType(T);
960}
961
962/// \brief Perform substitution on the base class specifiers of the
963/// given class template specialization.
964///
965/// Produces a diagnostic and returns true on error, returns false and
966/// attaches the instantiated base classes to the class template
967/// specialization if successful.
968bool
969Sema::SubstBaseSpecifiers(CXXRecordDecl *Instantiation,
970                          CXXRecordDecl *Pattern,
971                          const MultiLevelTemplateArgumentList &TemplateArgs) {
972  bool Invalid = false;
973  llvm::SmallVector<CXXBaseSpecifier*, 4> InstantiatedBases;
974  for (ClassTemplateSpecializationDecl::base_class_iterator
975         Base = Pattern->bases_begin(), BaseEnd = Pattern->bases_end();
976       Base != BaseEnd; ++Base) {
977    if (!Base->getType()->isDependentType()) {
978      const CXXRecordDecl *BaseDecl =
979        cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
980
981      // Make sure to set the attributes from the base.
982      SetClassDeclAttributesFromBase(Instantiation, BaseDecl,
983                                     Base->isVirtual());
984
985      InstantiatedBases.push_back(new (Context) CXXBaseSpecifier(*Base));
986      continue;
987    }
988
989    QualType BaseType = SubstType(Base->getType(),
990                                  TemplateArgs,
991                                  Base->getSourceRange().getBegin(),
992                                  DeclarationName());
993    if (BaseType.isNull()) {
994      Invalid = true;
995      continue;
996    }
997
998    if (CXXBaseSpecifier *InstantiatedBase
999          = CheckBaseSpecifier(Instantiation,
1000                               Base->getSourceRange(),
1001                               Base->isVirtual(),
1002                               Base->getAccessSpecifierAsWritten(),
1003                               BaseType,
1004                               /*FIXME: Not totally accurate */
1005                               Base->getSourceRange().getBegin()))
1006      InstantiatedBases.push_back(InstantiatedBase);
1007    else
1008      Invalid = true;
1009  }
1010
1011  if (!Invalid &&
1012      AttachBaseSpecifiers(Instantiation, InstantiatedBases.data(),
1013                           InstantiatedBases.size()))
1014    Invalid = true;
1015
1016  return Invalid;
1017}
1018
1019/// \brief Instantiate the definition of a class from a given pattern.
1020///
1021/// \param PointOfInstantiation The point of instantiation within the
1022/// source code.
1023///
1024/// \param Instantiation is the declaration whose definition is being
1025/// instantiated. This will be either a class template specialization
1026/// or a member class of a class template specialization.
1027///
1028/// \param Pattern is the pattern from which the instantiation
1029/// occurs. This will be either the declaration of a class template or
1030/// the declaration of a member class of a class template.
1031///
1032/// \param TemplateArgs The template arguments to be substituted into
1033/// the pattern.
1034///
1035/// \param TSK the kind of implicit or explicit instantiation to perform.
1036///
1037/// \param Complain whether to complain if the class cannot be instantiated due
1038/// to the lack of a definition.
1039///
1040/// \returns true if an error occurred, false otherwise.
1041bool
1042Sema::InstantiateClass(SourceLocation PointOfInstantiation,
1043                       CXXRecordDecl *Instantiation, CXXRecordDecl *Pattern,
1044                       const MultiLevelTemplateArgumentList &TemplateArgs,
1045                       TemplateSpecializationKind TSK,
1046                       bool Complain) {
1047  bool Invalid = false;
1048
1049  CXXRecordDecl *PatternDef
1050    = cast_or_null<CXXRecordDecl>(Pattern->getDefinition());
1051  if (!PatternDef) {
1052    if (!Complain) {
1053      // Say nothing
1054    } else if (Pattern == Instantiation->getInstantiatedFromMemberClass()) {
1055      Diag(PointOfInstantiation,
1056           diag::err_implicit_instantiate_member_undefined)
1057        << Context.getTypeDeclType(Instantiation);
1058      Diag(Pattern->getLocation(), diag::note_member_of_template_here);
1059    } else {
1060      Diag(PointOfInstantiation, diag::err_template_instantiate_undefined)
1061        << (TSK != TSK_ImplicitInstantiation)
1062        << Context.getTypeDeclType(Instantiation);
1063      Diag(Pattern->getLocation(), diag::note_template_decl_here);
1064    }
1065    return true;
1066  }
1067  Pattern = PatternDef;
1068
1069  // \brief Record the point of instantiation.
1070  if (MemberSpecializationInfo *MSInfo
1071        = Instantiation->getMemberSpecializationInfo()) {
1072    MSInfo->setTemplateSpecializationKind(TSK);
1073    MSInfo->setPointOfInstantiation(PointOfInstantiation);
1074  } else if (ClassTemplateSpecializationDecl *Spec
1075               = dyn_cast<ClassTemplateSpecializationDecl>(Instantiation)) {
1076    Spec->setTemplateSpecializationKind(TSK);
1077    Spec->setPointOfInstantiation(PointOfInstantiation);
1078  }
1079
1080  InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation);
1081  if (Inst)
1082    return true;
1083
1084  // Enter the scope of this instantiation. We don't use
1085  // PushDeclContext because we don't have a scope.
1086  DeclContext *PreviousContext = CurContext;
1087  CurContext = Instantiation;
1088
1089  // If this is an instantiation of a local class, merge this local
1090  // instantiation scope with the enclosing scope. Otherwise, every
1091  // instantiation of a class has its own local instantiation scope.
1092  bool MergeWithParentScope = !Instantiation->isDefinedOutsideFunctionOrMethod();
1093  Sema::LocalInstantiationScope Scope(*this, MergeWithParentScope);
1094
1095  // Start the definition of this instantiation.
1096  Instantiation->startDefinition();
1097
1098  // Do substitution on the base class specifiers.
1099  if (SubstBaseSpecifiers(Instantiation, Pattern, TemplateArgs))
1100    Invalid = true;
1101
1102  llvm::SmallVector<DeclPtrTy, 4> Fields;
1103  for (RecordDecl::decl_iterator Member = Pattern->decls_begin(),
1104         MemberEnd = Pattern->decls_end();
1105       Member != MemberEnd; ++Member) {
1106    Decl *NewMember = SubstDecl(*Member, Instantiation, TemplateArgs);
1107    if (NewMember) {
1108      if (FieldDecl *Field = dyn_cast<FieldDecl>(NewMember))
1109        Fields.push_back(DeclPtrTy::make(Field));
1110      else if (NewMember->isInvalidDecl())
1111        Invalid = true;
1112    } else {
1113      // FIXME: Eventually, a NULL return will mean that one of the
1114      // instantiations was a semantic disaster, and we'll want to set Invalid =
1115      // true. For now, we expect to skip some members that we can't yet handle.
1116    }
1117  }
1118
1119  // Finish checking fields.
1120  ActOnFields(0, Instantiation->getLocation(), DeclPtrTy::make(Instantiation),
1121              Fields.data(), Fields.size(), SourceLocation(), SourceLocation(),
1122              0);
1123  CheckCompletedCXXClass(Instantiation);
1124  if (Instantiation->isInvalidDecl())
1125    Invalid = true;
1126
1127  // Exit the scope of this instantiation.
1128  CurContext = PreviousContext;
1129
1130  // If this is a polymorphic C++ class without a key function, we'll
1131  // have to mark all of the virtual members to allow emission of a vtable
1132  // in this translation unit.
1133  if (Instantiation->isDynamicClass() &&
1134      !Context.getKeyFunction(Instantiation)) {
1135    // Local classes need to have their methods instantiated immediately in
1136    // order to have the correct instantiation scope.
1137    if (Instantiation->isLocalClass()) {
1138      MarkVirtualMembersReferenced(PointOfInstantiation,
1139                                   Instantiation);
1140    } else {
1141      ClassesWithUnmarkedVirtualMembers.push_back(std::make_pair(Instantiation,
1142                                                       PointOfInstantiation));
1143    }
1144  }
1145
1146  if (!Invalid)
1147    Consumer.HandleTagDeclDefinition(Instantiation);
1148
1149  return Invalid;
1150}
1151
1152bool
1153Sema::InstantiateClassTemplateSpecialization(
1154                           SourceLocation PointOfInstantiation,
1155                           ClassTemplateSpecializationDecl *ClassTemplateSpec,
1156                           TemplateSpecializationKind TSK,
1157                           bool Complain) {
1158  // Perform the actual instantiation on the canonical declaration.
1159  ClassTemplateSpec = cast<ClassTemplateSpecializationDecl>(
1160                                         ClassTemplateSpec->getCanonicalDecl());
1161
1162  // Check whether we have already instantiated or specialized this class
1163  // template specialization.
1164  if (ClassTemplateSpec->getSpecializationKind() != TSK_Undeclared) {
1165    if (ClassTemplateSpec->getSpecializationKind() ==
1166          TSK_ExplicitInstantiationDeclaration &&
1167        TSK == TSK_ExplicitInstantiationDefinition) {
1168      // An explicit instantiation definition follows an explicit instantiation
1169      // declaration (C++0x [temp.explicit]p10); go ahead and perform the
1170      // explicit instantiation.
1171      ClassTemplateSpec->setSpecializationKind(TSK);
1172      return false;
1173    }
1174
1175    // We can only instantiate something that hasn't already been
1176    // instantiated or specialized. Fail without any diagnostics: our
1177    // caller will provide an error message.
1178    return true;
1179  }
1180
1181  if (ClassTemplateSpec->isInvalidDecl())
1182    return true;
1183
1184  ClassTemplateDecl *Template = ClassTemplateSpec->getSpecializedTemplate();
1185  CXXRecordDecl *Pattern = 0;
1186
1187  // C++ [temp.class.spec.match]p1:
1188  //   When a class template is used in a context that requires an
1189  //   instantiation of the class, it is necessary to determine
1190  //   whether the instantiation is to be generated using the primary
1191  //   template or one of the partial specializations. This is done by
1192  //   matching the template arguments of the class template
1193  //   specialization with the template argument lists of the partial
1194  //   specializations.
1195  typedef std::pair<ClassTemplatePartialSpecializationDecl *,
1196                    TemplateArgumentList *> MatchResult;
1197  llvm::SmallVector<MatchResult, 4> Matched;
1198  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
1199         Partial = Template->getPartialSpecializations().begin(),
1200         PartialEnd = Template->getPartialSpecializations().end();
1201       Partial != PartialEnd;
1202       ++Partial) {
1203    TemplateDeductionInfo Info(Context, PointOfInstantiation);
1204    if (TemplateDeductionResult Result
1205          = DeduceTemplateArguments(&*Partial,
1206                                    ClassTemplateSpec->getTemplateArgs(),
1207                                    Info)) {
1208      // FIXME: Store the failed-deduction information for use in
1209      // diagnostics, later.
1210      (void)Result;
1211    } else {
1212      Matched.push_back(std::make_pair(&*Partial, Info.take()));
1213    }
1214  }
1215
1216  if (Matched.size() >= 1) {
1217    llvm::SmallVector<MatchResult, 4>::iterator Best = Matched.begin();
1218    if (Matched.size() == 1) {
1219      //   -- If exactly one matching specialization is found, the
1220      //      instantiation is generated from that specialization.
1221      // We don't need to do anything for this.
1222    } else {
1223      //   -- If more than one matching specialization is found, the
1224      //      partial order rules (14.5.4.2) are used to determine
1225      //      whether one of the specializations is more specialized
1226      //      than the others. If none of the specializations is more
1227      //      specialized than all of the other matching
1228      //      specializations, then the use of the class template is
1229      //      ambiguous and the program is ill-formed.
1230      for (llvm::SmallVector<MatchResult, 4>::iterator P = Best + 1,
1231                                                    PEnd = Matched.end();
1232           P != PEnd; ++P) {
1233        if (getMoreSpecializedPartialSpecialization(P->first, Best->first,
1234                                                    PointOfInstantiation)
1235              == P->first)
1236          Best = P;
1237      }
1238
1239      // Determine if the best partial specialization is more specialized than
1240      // the others.
1241      bool Ambiguous = false;
1242      for (llvm::SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
1243                                                    PEnd = Matched.end();
1244           P != PEnd; ++P) {
1245        if (P != Best &&
1246            getMoreSpecializedPartialSpecialization(P->first, Best->first,
1247                                                    PointOfInstantiation)
1248              != Best->first) {
1249          Ambiguous = true;
1250          break;
1251        }
1252      }
1253
1254      if (Ambiguous) {
1255        // Partial ordering did not produce a clear winner. Complain.
1256        ClassTemplateSpec->setInvalidDecl();
1257        Diag(PointOfInstantiation, diag::err_partial_spec_ordering_ambiguous)
1258          << ClassTemplateSpec;
1259
1260        // Print the matching partial specializations.
1261        for (llvm::SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
1262                                                      PEnd = Matched.end();
1263             P != PEnd; ++P)
1264          Diag(P->first->getLocation(), diag::note_partial_spec_match)
1265            << getTemplateArgumentBindingsText(P->first->getTemplateParameters(),
1266                                               *P->second);
1267
1268        return true;
1269      }
1270    }
1271
1272    // Instantiate using the best class template partial specialization.
1273    ClassTemplatePartialSpecializationDecl *OrigPartialSpec = Best->first;
1274    while (OrigPartialSpec->getInstantiatedFromMember()) {
1275      // If we've found an explicit specialization of this class template,
1276      // stop here and use that as the pattern.
1277      if (OrigPartialSpec->isMemberSpecialization())
1278        break;
1279
1280      OrigPartialSpec = OrigPartialSpec->getInstantiatedFromMember();
1281    }
1282
1283    Pattern = OrigPartialSpec;
1284    ClassTemplateSpec->setInstantiationOf(Best->first, Best->second);
1285  } else {
1286    //   -- If no matches are found, the instantiation is generated
1287    //      from the primary template.
1288    ClassTemplateDecl *OrigTemplate = Template;
1289    while (OrigTemplate->getInstantiatedFromMemberTemplate()) {
1290      // If we've found an explicit specialization of this class template,
1291      // stop here and use that as the pattern.
1292      if (OrigTemplate->isMemberSpecialization())
1293        break;
1294
1295      OrigTemplate = OrigTemplate->getInstantiatedFromMemberTemplate();
1296    }
1297
1298    Pattern = OrigTemplate->getTemplatedDecl();
1299  }
1300
1301  bool Result = InstantiateClass(PointOfInstantiation, ClassTemplateSpec,
1302                                 Pattern,
1303                                getTemplateInstantiationArgs(ClassTemplateSpec),
1304                                 TSK,
1305                                 Complain);
1306
1307  for (unsigned I = 0, N = Matched.size(); I != N; ++I) {
1308    // FIXME: Implement TemplateArgumentList::Destroy!
1309    //    if (Matched[I].first != Pattern)
1310    //      Matched[I].second->Destroy(Context);
1311  }
1312
1313  return Result;
1314}
1315
1316/// \brief Instantiates the definitions of all of the member
1317/// of the given class, which is an instantiation of a class template
1318/// or a member class of a template.
1319void
1320Sema::InstantiateClassMembers(SourceLocation PointOfInstantiation,
1321                              CXXRecordDecl *Instantiation,
1322                        const MultiLevelTemplateArgumentList &TemplateArgs,
1323                              TemplateSpecializationKind TSK) {
1324  for (DeclContext::decl_iterator D = Instantiation->decls_begin(),
1325                               DEnd = Instantiation->decls_end();
1326       D != DEnd; ++D) {
1327    bool SuppressNew = false;
1328    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(*D)) {
1329      if (FunctionDecl *Pattern
1330            = Function->getInstantiatedFromMemberFunction()) {
1331        MemberSpecializationInfo *MSInfo
1332          = Function->getMemberSpecializationInfo();
1333        assert(MSInfo && "No member specialization information?");
1334        if (CheckSpecializationInstantiationRedecl(PointOfInstantiation, TSK,
1335                                                   Function,
1336                                        MSInfo->getTemplateSpecializationKind(),
1337                                              MSInfo->getPointOfInstantiation(),
1338                                                   SuppressNew) ||
1339            SuppressNew)
1340          continue;
1341
1342        if (Function->getBody())
1343          continue;
1344
1345        if (TSK == TSK_ExplicitInstantiationDefinition) {
1346          // C++0x [temp.explicit]p8:
1347          //   An explicit instantiation definition that names a class template
1348          //   specialization explicitly instantiates the class template
1349          //   specialization and is only an explicit instantiation definition
1350          //   of members whose definition is visible at the point of
1351          //   instantiation.
1352          if (!Pattern->getBody())
1353            continue;
1354
1355          Function->setTemplateSpecializationKind(TSK, PointOfInstantiation);
1356
1357          InstantiateFunctionDefinition(PointOfInstantiation, Function);
1358        } else {
1359          Function->setTemplateSpecializationKind(TSK, PointOfInstantiation);
1360        }
1361      }
1362    } else if (VarDecl *Var = dyn_cast<VarDecl>(*D)) {
1363      if (Var->isStaticDataMember()) {
1364        MemberSpecializationInfo *MSInfo = Var->getMemberSpecializationInfo();
1365        assert(MSInfo && "No member specialization information?");
1366        if (CheckSpecializationInstantiationRedecl(PointOfInstantiation, TSK,
1367                                                   Var,
1368                                        MSInfo->getTemplateSpecializationKind(),
1369                                              MSInfo->getPointOfInstantiation(),
1370                                                   SuppressNew) ||
1371            SuppressNew)
1372          continue;
1373
1374        if (TSK == TSK_ExplicitInstantiationDefinition) {
1375          // C++0x [temp.explicit]p8:
1376          //   An explicit instantiation definition that names a class template
1377          //   specialization explicitly instantiates the class template
1378          //   specialization and is only an explicit instantiation definition
1379          //   of members whose definition is visible at the point of
1380          //   instantiation.
1381          if (!Var->getInstantiatedFromStaticDataMember()
1382                                                     ->getOutOfLineDefinition())
1383            continue;
1384
1385          Var->setTemplateSpecializationKind(TSK, PointOfInstantiation);
1386          InstantiateStaticDataMemberDefinition(PointOfInstantiation, Var);
1387        } else {
1388          Var->setTemplateSpecializationKind(TSK, PointOfInstantiation);
1389        }
1390      }
1391    } else if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(*D)) {
1392      if (Record->isInjectedClassName())
1393        continue;
1394
1395      MemberSpecializationInfo *MSInfo = Record->getMemberSpecializationInfo();
1396      assert(MSInfo && "No member specialization information?");
1397      if (CheckSpecializationInstantiationRedecl(PointOfInstantiation, TSK,
1398                                                 Record,
1399                                        MSInfo->getTemplateSpecializationKind(),
1400                                              MSInfo->getPointOfInstantiation(),
1401                                                 SuppressNew) ||
1402          SuppressNew)
1403        continue;
1404
1405      CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass();
1406      assert(Pattern && "Missing instantiated-from-template information");
1407
1408      if (!Record->getDefinition()) {
1409        if (!Pattern->getDefinition()) {
1410          // C++0x [temp.explicit]p8:
1411          //   An explicit instantiation definition that names a class template
1412          //   specialization explicitly instantiates the class template
1413          //   specialization and is only an explicit instantiation definition
1414          //   of members whose definition is visible at the point of
1415          //   instantiation.
1416          if (TSK == TSK_ExplicitInstantiationDeclaration) {
1417            MSInfo->setTemplateSpecializationKind(TSK);
1418            MSInfo->setPointOfInstantiation(PointOfInstantiation);
1419          }
1420
1421          continue;
1422        }
1423
1424        InstantiateClass(PointOfInstantiation, Record, Pattern,
1425                         TemplateArgs,
1426                         TSK);
1427      }
1428
1429      Pattern = cast_or_null<CXXRecordDecl>(Record->getDefinition());
1430      if (Pattern)
1431        InstantiateClassMembers(PointOfInstantiation, Pattern, TemplateArgs,
1432                                TSK);
1433    }
1434  }
1435}
1436
1437/// \brief Instantiate the definitions of all of the members of the
1438/// given class template specialization, which was named as part of an
1439/// explicit instantiation.
1440void
1441Sema::InstantiateClassTemplateSpecializationMembers(
1442                                           SourceLocation PointOfInstantiation,
1443                            ClassTemplateSpecializationDecl *ClassTemplateSpec,
1444                                               TemplateSpecializationKind TSK) {
1445  // C++0x [temp.explicit]p7:
1446  //   An explicit instantiation that names a class template
1447  //   specialization is an explicit instantion of the same kind
1448  //   (declaration or definition) of each of its members (not
1449  //   including members inherited from base classes) that has not
1450  //   been previously explicitly specialized in the translation unit
1451  //   containing the explicit instantiation, except as described
1452  //   below.
1453  InstantiateClassMembers(PointOfInstantiation, ClassTemplateSpec,
1454                          getTemplateInstantiationArgs(ClassTemplateSpec),
1455                          TSK);
1456}
1457
1458Sema::OwningStmtResult
1459Sema::SubstStmt(Stmt *S, const MultiLevelTemplateArgumentList &TemplateArgs) {
1460  if (!S)
1461    return Owned(S);
1462
1463  TemplateInstantiator Instantiator(*this, TemplateArgs,
1464                                    SourceLocation(),
1465                                    DeclarationName());
1466  return Instantiator.TransformStmt(S);
1467}
1468
1469Sema::OwningExprResult
1470Sema::SubstExpr(Expr *E, const MultiLevelTemplateArgumentList &TemplateArgs) {
1471  if (!E)
1472    return Owned(E);
1473
1474  TemplateInstantiator Instantiator(*this, TemplateArgs,
1475                                    SourceLocation(),
1476                                    DeclarationName());
1477  return Instantiator.TransformExpr(E);
1478}
1479
1480/// \brief Do template substitution on a nested-name-specifier.
1481NestedNameSpecifier *
1482Sema::SubstNestedNameSpecifier(NestedNameSpecifier *NNS,
1483                               SourceRange Range,
1484                         const MultiLevelTemplateArgumentList &TemplateArgs) {
1485  TemplateInstantiator Instantiator(*this, TemplateArgs, Range.getBegin(),
1486                                    DeclarationName());
1487  return Instantiator.TransformNestedNameSpecifier(NNS, Range);
1488}
1489
1490TemplateName
1491Sema::SubstTemplateName(TemplateName Name, SourceLocation Loc,
1492                        const MultiLevelTemplateArgumentList &TemplateArgs) {
1493  TemplateInstantiator Instantiator(*this, TemplateArgs, Loc,
1494                                    DeclarationName());
1495  return Instantiator.TransformTemplateName(Name);
1496}
1497
1498bool Sema::Subst(const TemplateArgumentLoc &Input, TemplateArgumentLoc &Output,
1499                 const MultiLevelTemplateArgumentList &TemplateArgs) {
1500  TemplateInstantiator Instantiator(*this, TemplateArgs, SourceLocation(),
1501                                    DeclarationName());
1502
1503  return Instantiator.TransformTemplateArgument(Input, Output);
1504}
1505