SemaTemplateInstantiateDecl.cpp revision 6c1c1b8c6ca743a5b6b4c81f9ac56392c12c7457 
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/Expr.h"
19#include "clang/AST/ExprCXX.h"
20#include "clang/Basic/PrettyStackTrace.h"
21#include "clang/Lex/Preprocessor.h"
22
23using namespace clang;
24
25namespace {
26  class TemplateDeclInstantiator
27    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
28    Sema &SemaRef;
29    DeclContext *Owner;
30    const MultiLevelTemplateArgumentList &TemplateArgs;
31
32    void InstantiateAttrs(Decl *Tmpl, Decl *New);
33
34  public:
35    typedef Sema::OwningExprResult OwningExprResult;
36
37    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
38                             const MultiLevelTemplateArgumentList &TemplateArgs)
39      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
40
41    // FIXME: Once we get closer to completion, replace these manually-written
42    // declarations with automatically-generated ones from
43    // clang/AST/DeclNodes.def.
44    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
45    Decl *VisitNamespaceDecl(NamespaceDecl *D);
46    Decl *VisitTypedefDecl(TypedefDecl *D);
47    Decl *VisitVarDecl(VarDecl *D);
48    Decl *VisitFieldDecl(FieldDecl *D);
49    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
50    Decl *VisitEnumDecl(EnumDecl *D);
51    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
52    Decl *VisitFriendDecl(FriendDecl *D);
53    Decl *VisitFunctionDecl(FunctionDecl *D,
54                            TemplateParameterList *TemplateParams = 0);
55    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
56    Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
57                             TemplateParameterList *TemplateParams = 0);
58    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
59    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
60    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
61    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
62    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
63    Decl *VisitClassTemplatePartialSpecializationDecl(
64                                    ClassTemplatePartialSpecializationDecl *D);
65    Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
66    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
67    Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
68    Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
69    Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
70    Decl *VisitUsingDecl(UsingDecl *D);
71    Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
72    Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
73    Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
74
75    // Base case. FIXME: Remove once we can instantiate everything.
76    Decl *VisitDecl(Decl *D) {
77      unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
78                                                            Diagnostic::Error,
79                                                   "cannot instantiate %0 yet");
80      SemaRef.Diag(D->getLocation(), DiagID)
81        << D->getDeclKindName();
82
83      return 0;
84    }
85
86    const LangOptions &getLangOptions() {
87      return SemaRef.getLangOptions();
88    }
89
90    // Helper functions for instantiating methods.
91    QualType SubstFunctionType(FunctionDecl *D,
92                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
93    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
94    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
95
96    TemplateParameterList *
97      SubstTemplateParams(TemplateParameterList *List);
98
99    bool InstantiateClassTemplatePartialSpecialization(
100                                              ClassTemplateDecl *ClassTemplate,
101                           ClassTemplatePartialSpecializationDecl *PartialSpec);
102  };
103}
104
105// FIXME: Is this too simple?
106void TemplateDeclInstantiator::InstantiateAttrs(Decl *Tmpl, Decl *New) {
107  for (const Attr *TmplAttr = Tmpl->getAttrs(); TmplAttr;
108       TmplAttr = TmplAttr->getNext()) {
109
110    // FIXME: Is cloning correct for all attributes?
111    Attr *NewAttr = TmplAttr->clone(SemaRef.Context);
112
113    New->addAttr(NewAttr);
114  }
115}
116
117Decl *
118TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
119  assert(false && "Translation units cannot be instantiated");
120  return D;
121}
122
123Decl *
124TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
125  assert(false && "Namespaces cannot be instantiated");
126  return D;
127}
128
129Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
130  bool Invalid = false;
131  TypeSourceInfo *DI = D->getTypeSourceInfo();
132  if (DI->getType()->isDependentType()) {
133    DI = SemaRef.SubstType(DI, TemplateArgs,
134                           D->getLocation(), D->getDeclName());
135    if (!DI) {
136      Invalid = true;
137      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
138    }
139  }
140
141  // Create the new typedef
142  TypedefDecl *Typedef
143    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
144                          D->getIdentifier(), DI);
145  if (Invalid)
146    Typedef->setInvalidDecl();
147
148  Owner->addDecl(Typedef);
149
150  return Typedef;
151}
152
153/// \brief Instantiate the arguments provided as part of initialization.
154///
155/// \returns true if an error occurred, false otherwise.
156static bool InstantiateInitializationArguments(Sema &SemaRef,
157                                               Expr **Args, unsigned NumArgs,
158                           const MultiLevelTemplateArgumentList &TemplateArgs,
159                         llvm::SmallVectorImpl<SourceLocation> &FakeCommaLocs,
160                           ASTOwningVector<&ActionBase::DeleteExpr> &InitArgs) {
161  for (unsigned I = 0; I != NumArgs; ++I) {
162    // When we hit the first defaulted argument, break out of the loop:
163    // we don't pass those default arguments on.
164    if (Args[I]->isDefaultArgument())
165      break;
166
167    Sema::OwningExprResult Arg = SemaRef.SubstExpr(Args[I], TemplateArgs);
168    if (Arg.isInvalid())
169      return true;
170
171    Expr *ArgExpr = (Expr *)Arg.get();
172    InitArgs.push_back(Arg.release());
173
174    // FIXME: We're faking all of the comma locations. Do we need them?
175    FakeCommaLocs.push_back(
176                          SemaRef.PP.getLocForEndOfToken(ArgExpr->getLocEnd()));
177  }
178
179  return false;
180}
181
182Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
183  // Do substitution on the type of the declaration
184  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
185                                         TemplateArgs,
186                                         D->getTypeSpecStartLoc(),
187                                         D->getDeclName());
188  if (!DI)
189    return 0;
190
191  // Build the instantiated declaration
192  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
193                                 D->getLocation(), D->getIdentifier(),
194                                 DI->getType(), DI,
195                                 D->getStorageClass());
196  Var->setThreadSpecified(D->isThreadSpecified());
197  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
198  Var->setDeclaredInCondition(D->isDeclaredInCondition());
199
200  // If we are instantiating a static data member defined
201  // out-of-line, the instantiation will have the same lexical
202  // context (which will be a namespace scope) as the template.
203  if (D->isOutOfLine())
204    Var->setLexicalDeclContext(D->getLexicalDeclContext());
205
206  // FIXME: In theory, we could have a previous declaration for variables that
207  // are not static data members.
208  bool Redeclaration = false;
209  // FIXME: having to fake up a LookupResult is dumb.
210  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
211                        Sema::LookupOrdinaryName);
212  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
213
214  if (D->isOutOfLine()) {
215    D->getLexicalDeclContext()->addDecl(Var);
216    Owner->makeDeclVisibleInContext(Var);
217  } else {
218    Owner->addDecl(Var);
219  }
220
221  // Link instantiations of static data members back to the template from
222  // which they were instantiated.
223  if (Var->isStaticDataMember())
224    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
225                                                     TSK_ImplicitInstantiation);
226
227  if (D->getInit()) {
228    if (Var->isStaticDataMember() && !D->isOutOfLine())
229      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
230    else
231      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
232
233    // Extract the initializer, skipping through any temporary-binding
234    // expressions and look at the subexpression as it was written.
235    Expr *DInit = D->getInit();
236    while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(DInit))
237      DInit = Binder->getSubExpr();
238    if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(DInit))
239      DInit = ICE->getSubExprAsWritten();
240
241    if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(DInit)) {
242      // The initializer is a parenthesized list of expressions that is
243      // type-dependent. Instantiate each of the expressions; we'll be
244      // performing direct initialization with them.
245      llvm::SmallVector<SourceLocation, 4> CommaLocs;
246      ASTOwningVector<&ActionBase::DeleteExpr> InitArgs(SemaRef);
247      if (!InstantiateInitializationArguments(SemaRef,
248                                              PLE->getExprs(),
249                                              PLE->getNumExprs(),
250                                              TemplateArgs,
251                                              CommaLocs, InitArgs)) {
252        // Add the direct initializer to the declaration.
253        SemaRef.AddCXXDirectInitializerToDecl(Sema::DeclPtrTy::make(Var),
254                                              PLE->getLParenLoc(),
255                                              move_arg(InitArgs),
256                                              CommaLocs.data(),
257                                              PLE->getRParenLoc());
258      }
259    } else if (CXXConstructExpr *Construct =dyn_cast<CXXConstructExpr>(DInit)) {
260      // The initializer resolved to a constructor. Instantiate the constructor
261      // arguments.
262      llvm::SmallVector<SourceLocation, 4> CommaLocs;
263      ASTOwningVector<&ActionBase::DeleteExpr> InitArgs(SemaRef);
264
265      if (!InstantiateInitializationArguments(SemaRef,
266                                              Construct->getArgs(),
267                                              Construct->getNumArgs(),
268                                              TemplateArgs,
269                                              CommaLocs, InitArgs)) {
270        if (D->hasCXXDirectInitializer()) {
271          SourceLocation FakeLParenLoc =
272            SemaRef.PP.getLocForEndOfToken(D->getLocation());
273          SourceLocation FakeRParenLoc = CommaLocs.empty()? FakeLParenLoc
274                                                          : CommaLocs.back();
275          SemaRef.AddCXXDirectInitializerToDecl(Sema::DeclPtrTy::make(Var),
276                                                FakeLParenLoc,
277                                                move_arg(InitArgs),
278                                                CommaLocs.data(),
279                                                FakeRParenLoc);
280        } else if (InitArgs.size() == 1) {
281          Expr *Init = (Expr*)(InitArgs.take()[0]);
282          SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var),
283                                       SemaRef.Owned(Init),
284                                       false);
285        } else {
286          assert(InitArgs.size() == 0);
287          SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
288        }
289      }
290    } else {
291      OwningExprResult Init
292        = SemaRef.SubstExpr(D->getInit(), TemplateArgs);
293
294      // FIXME: Not happy about invalidating decls just because of a bad
295      // initializer, unless it affects the type.
296      if (Init.isInvalid())
297        Var->setInvalidDecl();
298      else
299        SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var), move(Init),
300                                     D->hasCXXDirectInitializer());
301    }
302
303    SemaRef.PopExpressionEvaluationContext();
304  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
305    SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
306
307  return Var;
308}
309
310Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
311  bool Invalid = false;
312  TypeSourceInfo *DI = D->getTypeSourceInfo();
313  if (DI->getType()->isDependentType())  {
314    DI = SemaRef.SubstType(DI, TemplateArgs,
315                           D->getLocation(), D->getDeclName());
316    if (!DI) {
317      DI = D->getTypeSourceInfo();
318      Invalid = true;
319    } else if (DI->getType()->isFunctionType()) {
320      // C++ [temp.arg.type]p3:
321      //   If a declaration acquires a function type through a type
322      //   dependent on a template-parameter and this causes a
323      //   declaration that does not use the syntactic form of a
324      //   function declarator to have function type, the program is
325      //   ill-formed.
326      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
327        << DI->getType();
328      Invalid = true;
329    }
330  }
331
332  Expr *BitWidth = D->getBitWidth();
333  if (Invalid)
334    BitWidth = 0;
335  else if (BitWidth) {
336    // The bit-width expression is not potentially evaluated.
337    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
338
339    OwningExprResult InstantiatedBitWidth
340      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
341    if (InstantiatedBitWidth.isInvalid()) {
342      Invalid = true;
343      BitWidth = 0;
344    } else
345      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
346  }
347
348  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
349                                            DI->getType(), DI,
350                                            cast<RecordDecl>(Owner),
351                                            D->getLocation(),
352                                            D->isMutable(),
353                                            BitWidth,
354                                            D->getTypeSpecStartLoc(),
355                                            D->getAccess(),
356                                            0);
357  if (!Field) {
358    cast<Decl>(Owner)->setInvalidDecl();
359    return 0;
360  }
361
362  InstantiateAttrs(D, Field);
363
364  if (Invalid)
365    Field->setInvalidDecl();
366
367  if (!Field->getDeclName()) {
368    // Keep track of where this decl came from.
369    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
370  }
371
372  Field->setImplicit(D->isImplicit());
373  Owner->addDecl(Field);
374
375  return Field;
376}
377
378Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
379  FriendDecl::FriendUnion FU;
380
381  // Handle friend type expressions by simply substituting template
382  // parameters into the pattern type.
383  if (Type *Ty = D->getFriendType()) {
384    QualType T = SemaRef.SubstType(QualType(Ty,0), TemplateArgs,
385                                   D->getLocation(), DeclarationName());
386    if (T.isNull()) return 0;
387
388    assert(getLangOptions().CPlusPlus0x || T->isRecordType());
389    FU = T.getTypePtr();
390
391  // Handle everything else by appropriate substitution.
392  } else {
393    NamedDecl *ND = D->getFriendDecl();
394    assert(ND && "friend decl must be a decl or a type!");
395
396    // FIXME: We have a problem here, because the nested call to Visit(ND)
397    // will inject the thing that the friend references into the current
398    // owner, which is wrong.
399    Decl *NewND = Visit(ND);
400    if (!NewND) return 0;
401
402    FU = cast<NamedDecl>(NewND);
403  }
404
405  FriendDecl *FD =
406    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(), FU,
407                       D->getFriendLoc());
408  FD->setAccess(AS_public);
409  Owner->addDecl(FD);
410  return FD;
411}
412
413Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
414  Expr *AssertExpr = D->getAssertExpr();
415
416  // The expression in a static assertion is not potentially evaluated.
417  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
418
419  OwningExprResult InstantiatedAssertExpr
420    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
421  if (InstantiatedAssertExpr.isInvalid())
422    return 0;
423
424  OwningExprResult Message(SemaRef, D->getMessage());
425  D->getMessage()->Retain();
426  Decl *StaticAssert
427    = SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
428                                           move(InstantiatedAssertExpr),
429                                           move(Message)).getAs<Decl>();
430  return StaticAssert;
431}
432
433Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
434  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
435                                    D->getLocation(), D->getIdentifier(),
436                                    D->getTagKeywordLoc(),
437                                    /*PrevDecl=*/0);
438  Enum->setInstantiationOfMemberEnum(D);
439  Enum->setAccess(D->getAccess());
440  Owner->addDecl(Enum);
441  Enum->startDefinition();
442
443  llvm::SmallVector<Sema::DeclPtrTy, 4> Enumerators;
444
445  EnumConstantDecl *LastEnumConst = 0;
446  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
447         ECEnd = D->enumerator_end();
448       EC != ECEnd; ++EC) {
449    // The specified value for the enumerator.
450    OwningExprResult Value = SemaRef.Owned((Expr *)0);
451    if (Expr *UninstValue = EC->getInitExpr()) {
452      // The enumerator's value expression is not potentially evaluated.
453      EnterExpressionEvaluationContext Unevaluated(SemaRef,
454                                                   Action::Unevaluated);
455
456      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
457    }
458
459    // Drop the initial value and continue.
460    bool isInvalid = false;
461    if (Value.isInvalid()) {
462      Value = SemaRef.Owned((Expr *)0);
463      isInvalid = true;
464    }
465
466    EnumConstantDecl *EnumConst
467      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
468                                  EC->getLocation(), EC->getIdentifier(),
469                                  move(Value));
470
471    if (isInvalid) {
472      if (EnumConst)
473        EnumConst->setInvalidDecl();
474      Enum->setInvalidDecl();
475    }
476
477    if (EnumConst) {
478      Enum->addDecl(EnumConst);
479      Enumerators.push_back(Sema::DeclPtrTy::make(EnumConst));
480      LastEnumConst = EnumConst;
481    }
482  }
483
484  // FIXME: Fixup LBraceLoc and RBraceLoc
485  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
486  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
487                        Sema::DeclPtrTy::make(Enum),
488                        &Enumerators[0], Enumerators.size(),
489                        0, 0);
490
491  return Enum;
492}
493
494Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
495  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
496  return 0;
497}
498
499namespace {
500  class SortDeclByLocation {
501    SourceManager &SourceMgr;
502
503  public:
504    explicit SortDeclByLocation(SourceManager &SourceMgr)
505      : SourceMgr(SourceMgr) { }
506
507    bool operator()(const Decl *X, const Decl *Y) const {
508      return SourceMgr.isBeforeInTranslationUnit(X->getLocation(),
509                                                 Y->getLocation());
510    }
511  };
512}
513
514Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
515  // Create a local instantiation scope for this class template, which
516  // will contain the instantiations of the template parameters.
517  Sema::LocalInstantiationScope Scope(SemaRef);
518  TemplateParameterList *TempParams = D->getTemplateParameters();
519  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
520  if (!InstParams)
521    return NULL;
522
523  CXXRecordDecl *Pattern = D->getTemplatedDecl();
524  CXXRecordDecl *RecordInst
525    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), Owner,
526                            Pattern->getLocation(), Pattern->getIdentifier(),
527                            Pattern->getTagKeywordLoc(), /*PrevDecl=*/ NULL,
528                            /*DelayTypeCreation=*/true);
529
530  ClassTemplateDecl *Inst
531    = ClassTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
532                                D->getIdentifier(), InstParams, RecordInst, 0);
533  RecordInst->setDescribedClassTemplate(Inst);
534  if (D->getFriendObjectKind())
535    Inst->setObjectOfFriendDecl(true);
536  else
537    Inst->setAccess(D->getAccess());
538  Inst->setInstantiatedFromMemberTemplate(D);
539
540  // Trigger creation of the type for the instantiation.
541  SemaRef.Context.getTypeDeclType(RecordInst);
542
543  // Finish handling of friends.
544  if (Inst->getFriendObjectKind()) {
545    return Inst;
546  }
547
548  Owner->addDecl(Inst);
549
550  // First, we sort the partial specializations by location, so
551  // that we instantiate them in the order they were declared.
552  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
553  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
554         P = D->getPartialSpecializations().begin(),
555         PEnd = D->getPartialSpecializations().end();
556       P != PEnd; ++P)
557    PartialSpecs.push_back(&*P);
558  std::sort(PartialSpecs.begin(), PartialSpecs.end(),
559            SortDeclByLocation(SemaRef.SourceMgr));
560
561  // Instantiate all of the partial specializations of this member class
562  // template.
563  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
564    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
565
566  return Inst;
567}
568
569Decl *
570TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
571                                   ClassTemplatePartialSpecializationDecl *D) {
572  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
573
574  // Lookup the already-instantiated declaration in the instantiation
575  // of the class template and return that.
576  DeclContext::lookup_result Found
577    = Owner->lookup(ClassTemplate->getDeclName());
578  if (Found.first == Found.second)
579    return 0;
580
581  ClassTemplateDecl *InstClassTemplate
582    = dyn_cast<ClassTemplateDecl>(*Found.first);
583  if (!InstClassTemplate)
584    return 0;
585
586  Decl *DCanon = D->getCanonicalDecl();
587  for (llvm::FoldingSet<ClassTemplatePartialSpecializationDecl>::iterator
588            P = InstClassTemplate->getPartialSpecializations().begin(),
589         PEnd = InstClassTemplate->getPartialSpecializations().end();
590       P != PEnd; ++P) {
591    if (P->getInstantiatedFromMember()->getCanonicalDecl() == DCanon)
592      return &*P;
593  }
594
595  return 0;
596}
597
598Decl *
599TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
600  // Create a local instantiation scope for this function template, which
601  // will contain the instantiations of the template parameters and then get
602  // merged with the local instantiation scope for the function template
603  // itself.
604  Sema::LocalInstantiationScope Scope(SemaRef);
605
606  TemplateParameterList *TempParams = D->getTemplateParameters();
607  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
608  if (!InstParams)
609    return NULL;
610
611  FunctionDecl *Instantiated = 0;
612  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
613    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
614                                                                 InstParams));
615  else
616    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
617                                                          D->getTemplatedDecl(),
618                                                                InstParams));
619
620  if (!Instantiated)
621    return 0;
622
623  // Link the instantiated function template declaration to the function
624  // template from which it was instantiated.
625  FunctionTemplateDecl *InstTemplate
626    = Instantiated->getDescribedFunctionTemplate();
627  InstTemplate->setAccess(D->getAccess());
628  assert(InstTemplate &&
629         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
630
631  // Link the instantiation back to the pattern *unless* this is a
632  // non-definition friend declaration.
633  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
634      !(InstTemplate->getFriendObjectKind() &&
635        !D->getTemplatedDecl()->isThisDeclarationADefinition()))
636    InstTemplate->setInstantiatedFromMemberTemplate(D);
637
638  // Add non-friends into the owner.
639  if (!InstTemplate->getFriendObjectKind())
640    Owner->addDecl(InstTemplate);
641  return InstTemplate;
642}
643
644Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
645  CXXRecordDecl *PrevDecl = 0;
646  if (D->isInjectedClassName())
647    PrevDecl = cast<CXXRecordDecl>(Owner);
648  else if (D->getPreviousDeclaration()) {
649    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getPreviousDeclaration(),
650                                                   TemplateArgs);
651    if (!Prev) return 0;
652    PrevDecl = cast<CXXRecordDecl>(Prev);
653  }
654
655  CXXRecordDecl *Record
656    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
657                            D->getLocation(), D->getIdentifier(),
658                            D->getTagKeywordLoc(), PrevDecl);
659  Record->setImplicit(D->isImplicit());
660  // FIXME: Check against AS_none is an ugly hack to work around the issue that
661  // the tag decls introduced by friend class declarations don't have an access
662  // specifier. Remove once this area of the code gets sorted out.
663  if (D->getAccess() != AS_none)
664    Record->setAccess(D->getAccess());
665  if (!D->isInjectedClassName())
666    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
667
668  // If the original function was part of a friend declaration,
669  // inherit its namespace state.
670  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
671    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
672
673  Record->setAnonymousStructOrUnion(D->isAnonymousStructOrUnion());
674
675  Owner->addDecl(Record);
676  return Record;
677}
678
679/// Normal class members are of more specific types and therefore
680/// don't make it here.  This function serves two purposes:
681///   1) instantiating function templates
682///   2) substituting friend declarations
683/// FIXME: preserve function definitions in case #2
684  Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
685                                       TemplateParameterList *TemplateParams) {
686  // Check whether there is already a function template specialization for
687  // this declaration.
688  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
689  void *InsertPos = 0;
690  if (FunctionTemplate && !TemplateParams) {
691    llvm::FoldingSetNodeID ID;
692    FunctionTemplateSpecializationInfo::Profile(ID,
693                             TemplateArgs.getInnermost().getFlatArgumentList(),
694                                       TemplateArgs.getInnermost().flat_size(),
695                                                SemaRef.Context);
696
697    FunctionTemplateSpecializationInfo *Info
698      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
699                                                                   InsertPos);
700
701    // If we already have a function template specialization, return it.
702    if (Info)
703      return Info->Function;
704  }
705
706  Sema::LocalInstantiationScope Scope(SemaRef, TemplateParams != 0);
707
708  llvm::SmallVector<ParmVarDecl *, 4> Params;
709  QualType T = SubstFunctionType(D, Params);
710  if (T.isNull())
711    return 0;
712
713  // Build the instantiated method declaration.
714  DeclContext *DC = SemaRef.FindInstantiatedContext(D->getDeclContext(),
715                                                    TemplateArgs);
716  FunctionDecl *Function =
717      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
718                           D->getDeclName(), T, D->getTypeSourceInfo(),
719                           D->getStorageClass(),
720                           D->isInlineSpecified(), D->hasWrittenPrototype());
721  Function->setLexicalDeclContext(Owner);
722
723  // Attach the parameters
724  for (unsigned P = 0; P < Params.size(); ++P)
725    Params[P]->setOwningFunction(Function);
726  Function->setParams(SemaRef.Context, Params.data(), Params.size());
727
728  if (TemplateParams) {
729    // Our resulting instantiation is actually a function template, since we
730    // are substituting only the outer template parameters. For example, given
731    //
732    //   template<typename T>
733    //   struct X {
734    //     template<typename U> friend void f(T, U);
735    //   };
736    //
737    //   X<int> x;
738    //
739    // We are instantiating the friend function template "f" within X<int>,
740    // which means substituting int for T, but leaving "f" as a friend function
741    // template.
742    // Build the function template itself.
743    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Owner,
744                                                    Function->getLocation(),
745                                                    Function->getDeclName(),
746                                                    TemplateParams, Function);
747    Function->setDescribedFunctionTemplate(FunctionTemplate);
748    FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
749  } else if (FunctionTemplate) {
750    // Record this function template specialization.
751    Function->setFunctionTemplateSpecialization(SemaRef.Context,
752                                                FunctionTemplate,
753                                                &TemplateArgs.getInnermost(),
754                                                InsertPos);
755  }
756
757  if (InitFunctionInstantiation(Function, D))
758    Function->setInvalidDecl();
759
760  bool Redeclaration = false;
761  bool OverloadableAttrRequired = false;
762
763  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
764                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
765
766  if (TemplateParams || !FunctionTemplate) {
767    // Look only into the namespace where the friend would be declared to
768    // find a previous declaration. This is the innermost enclosing namespace,
769    // as described in ActOnFriendFunctionDecl.
770    SemaRef.LookupQualifiedName(Previous, DC);
771
772    // In C++, the previous declaration we find might be a tag type
773    // (class or enum). In this case, the new declaration will hide the
774    // tag type. Note that this does does not apply if we're declaring a
775    // typedef (C++ [dcl.typedef]p4).
776    if (Previous.isSingleTagDecl())
777      Previous.clear();
778  }
779
780  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
781                                   false, Redeclaration,
782                                   /*FIXME:*/OverloadableAttrRequired);
783
784  // If the original function was part of a friend declaration,
785  // inherit its namespace state and add it to the owner.
786  NamedDecl *FromFriendD
787      = TemplateParams? cast<NamedDecl>(D->getDescribedFunctionTemplate()) : D;
788  if (FromFriendD->getFriendObjectKind()) {
789    NamedDecl *ToFriendD = 0;
790    NamedDecl *PrevDecl;
791    if (TemplateParams) {
792      ToFriendD = cast<NamedDecl>(FunctionTemplate);
793      PrevDecl = FunctionTemplate->getPreviousDeclaration();
794    } else {
795      ToFriendD = Function;
796      PrevDecl = Function->getPreviousDeclaration();
797    }
798    ToFriendD->setObjectOfFriendDecl(PrevDecl != NULL);
799    if (!Owner->isDependentContext() && !PrevDecl)
800      DC->makeDeclVisibleInContext(ToFriendD, /* Recoverable = */ false);
801
802    if (!TemplateParams)
803      Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
804  }
805
806  return Function;
807}
808
809Decl *
810TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
811                                      TemplateParameterList *TemplateParams) {
812  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
813  void *InsertPos = 0;
814  if (FunctionTemplate && !TemplateParams) {
815    // We are creating a function template specialization from a function
816    // template. Check whether there is already a function template
817    // specialization for this particular set of template arguments.
818    llvm::FoldingSetNodeID ID;
819    FunctionTemplateSpecializationInfo::Profile(ID,
820                            TemplateArgs.getInnermost().getFlatArgumentList(),
821                                      TemplateArgs.getInnermost().flat_size(),
822                                                SemaRef.Context);
823
824    FunctionTemplateSpecializationInfo *Info
825      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
826                                                                   InsertPos);
827
828    // If we already have a function template specialization, return it.
829    if (Info)
830      return Info->Function;
831  }
832
833  Sema::LocalInstantiationScope Scope(SemaRef, TemplateParams != 0);
834
835  llvm::SmallVector<ParmVarDecl *, 4> Params;
836  QualType T = SubstFunctionType(D, Params);
837  if (T.isNull())
838    return 0;
839
840  // Build the instantiated method declaration.
841  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
842  CXXMethodDecl *Method = 0;
843
844  DeclarationName Name = D->getDeclName();
845  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
846    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
847    Name = SemaRef.Context.DeclarationNames.getCXXConstructorName(
848                                    SemaRef.Context.getCanonicalType(ClassTy));
849    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
850                                        Constructor->getLocation(),
851                                        Name, T,
852                                        Constructor->getTypeSourceInfo(),
853                                        Constructor->isExplicit(),
854                                        Constructor->isInlineSpecified(), false);
855  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
856    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
857    Name = SemaRef.Context.DeclarationNames.getCXXDestructorName(
858                                   SemaRef.Context.getCanonicalType(ClassTy));
859    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
860                                       Destructor->getLocation(), Name,
861                                       T, Destructor->isInlineSpecified(), false);
862  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
863    CanQualType ConvTy
864      = SemaRef.Context.getCanonicalType(
865                                      T->getAs<FunctionType>()->getResultType());
866    Name = SemaRef.Context.DeclarationNames.getCXXConversionFunctionName(
867                                                                      ConvTy);
868    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
869                                       Conversion->getLocation(), Name,
870                                       T, Conversion->getTypeSourceInfo(),
871                                       Conversion->isInlineSpecified(),
872                                       Conversion->isExplicit());
873  } else {
874    Method = CXXMethodDecl::Create(SemaRef.Context, Record, D->getLocation(),
875                                   D->getDeclName(), T, D->getTypeSourceInfo(),
876                                   D->isStatic(), D->isInlineSpecified());
877  }
878
879  if (TemplateParams) {
880    // Our resulting instantiation is actually a function template, since we
881    // are substituting only the outer template parameters. For example, given
882    //
883    //   template<typename T>
884    //   struct X {
885    //     template<typename U> void f(T, U);
886    //   };
887    //
888    //   X<int> x;
889    //
890    // We are instantiating the member template "f" within X<int>, which means
891    // substituting int for T, but leaving "f" as a member function template.
892    // Build the function template itself.
893    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
894                                                    Method->getLocation(),
895                                                    Method->getDeclName(),
896                                                    TemplateParams, Method);
897    if (D->isOutOfLine())
898      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
899    Method->setDescribedFunctionTemplate(FunctionTemplate);
900  } else if (FunctionTemplate) {
901    // Record this function template specialization.
902    Method->setFunctionTemplateSpecialization(SemaRef.Context,
903                                              FunctionTemplate,
904                                              &TemplateArgs.getInnermost(),
905                                              InsertPos);
906  } else {
907    // Record that this is an instantiation of a member function.
908    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
909  }
910
911  // If we are instantiating a member function defined
912  // out-of-line, the instantiation will have the same lexical
913  // context (which will be a namespace scope) as the template.
914  if (D->isOutOfLine())
915    Method->setLexicalDeclContext(D->getLexicalDeclContext());
916
917  // Attach the parameters
918  for (unsigned P = 0; P < Params.size(); ++P)
919    Params[P]->setOwningFunction(Method);
920  Method->setParams(SemaRef.Context, Params.data(), Params.size());
921
922  if (InitMethodInstantiation(Method, D))
923    Method->setInvalidDecl();
924
925  LookupResult Previous(SemaRef, Name, SourceLocation(),
926                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
927
928  if (!FunctionTemplate || TemplateParams) {
929    SemaRef.LookupQualifiedName(Previous, Owner);
930
931    // In C++, the previous declaration we find might be a tag type
932    // (class or enum). In this case, the new declaration will hide the
933    // tag type. Note that this does does not apply if we're declaring a
934    // typedef (C++ [dcl.typedef]p4).
935    if (Previous.isSingleTagDecl())
936      Previous.clear();
937  }
938
939  bool Redeclaration = false;
940  bool OverloadableAttrRequired = false;
941  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
942                                   /*FIXME:*/OverloadableAttrRequired);
943
944  if (D->isPure())
945    SemaRef.CheckPureMethod(Method, SourceRange());
946
947  if (!FunctionTemplate && (!Method->isInvalidDecl() || Previous.empty()) &&
948      !Method->getFriendObjectKind())
949    Owner->addDecl(Method);
950
951  return Method;
952}
953
954Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
955  return VisitCXXMethodDecl(D);
956}
957
958Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
959  return VisitCXXMethodDecl(D);
960}
961
962Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
963  return VisitCXXMethodDecl(D);
964}
965
966ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
967  QualType T;
968  TypeSourceInfo *DI = D->getTypeSourceInfo();
969  if (DI) {
970    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
971                           D->getDeclName());
972    if (DI) T = DI->getType();
973  } else {
974    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
975                          D->getDeclName());
976    DI = 0;
977  }
978
979  if (T.isNull())
980    return 0;
981
982  T = SemaRef.adjustParameterType(T);
983
984  // Allocate the parameter
985  ParmVarDecl *Param
986    = ParmVarDecl::Create(SemaRef.Context, Owner, D->getLocation(),
987                          D->getIdentifier(), T, DI, D->getStorageClass(), 0);
988
989  // Mark the default argument as being uninstantiated.
990  if (D->hasUninstantiatedDefaultArg())
991    Param->setUninstantiatedDefaultArg(D->getUninstantiatedDefaultArg());
992  else if (Expr *Arg = D->getDefaultArg())
993    Param->setUninstantiatedDefaultArg(Arg);
994
995  // Note: we don't try to instantiate function parameters until after
996  // we've instantiated the function's type. Therefore, we don't have
997  // to check for 'void' parameter types here.
998  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
999  return Param;
1000}
1001
1002Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1003                                                    TemplateTypeParmDecl *D) {
1004  // TODO: don't always clone when decls are refcounted.
1005  const Type* T = D->getTypeForDecl();
1006  assert(T->isTemplateTypeParmType());
1007  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1008
1009  TemplateTypeParmDecl *Inst =
1010    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1011                                 TTPT->getDepth() - 1, TTPT->getIndex(),
1012                                 TTPT->getName(),
1013                                 D->wasDeclaredWithTypename(),
1014                                 D->isParameterPack());
1015
1016  if (D->hasDefaultArgument())
1017    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1018
1019  // Introduce this template parameter's instantiation into the instantiation
1020  // scope.
1021  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1022
1023  return Inst;
1024}
1025
1026Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1027                                                 NonTypeTemplateParmDecl *D) {
1028  // Substitute into the type of the non-type template parameter.
1029  QualType T;
1030  TypeSourceInfo *DI = D->getTypeSourceInfo();
1031  if (DI) {
1032    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1033                           D->getDeclName());
1034    if (DI) T = DI->getType();
1035  } else {
1036    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1037                          D->getDeclName());
1038    DI = 0;
1039  }
1040  if (T.isNull())
1041    return 0;
1042
1043  // Check that this type is acceptable for a non-type template parameter.
1044  bool Invalid = false;
1045  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1046  if (T.isNull()) {
1047    T = SemaRef.Context.IntTy;
1048    Invalid = true;
1049  }
1050
1051  NonTypeTemplateParmDecl *Param
1052    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1053                                      D->getDepth() - 1, D->getPosition(),
1054                                      D->getIdentifier(), T, DI);
1055  if (Invalid)
1056    Param->setInvalidDecl();
1057
1058  Param->setDefaultArgument(D->getDefaultArgument());
1059
1060  // Introduce this template parameter's instantiation into the instantiation
1061  // scope.
1062  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1063  return Param;
1064}
1065
1066Decl *
1067TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1068                                                  TemplateTemplateParmDecl *D) {
1069  // Instantiate the template parameter list of the template template parameter.
1070  TemplateParameterList *TempParams = D->getTemplateParameters();
1071  TemplateParameterList *InstParams;
1072  {
1073    // Perform the actual substitution of template parameters within a new,
1074    // local instantiation scope.
1075    Sema::LocalInstantiationScope Scope(SemaRef);
1076    InstParams = SubstTemplateParams(TempParams);
1077    if (!InstParams)
1078      return NULL;
1079  }
1080
1081  // Build the template template parameter.
1082  TemplateTemplateParmDecl *Param
1083    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1084                                       D->getDepth() - 1, D->getPosition(),
1085                                       D->getIdentifier(), InstParams);
1086  Param->setDefaultArgument(D->getDefaultArgument());
1087
1088  // Introduce this template parameter's instantiation into the instantiation
1089  // scope.
1090  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1091
1092  return Param;
1093}
1094
1095Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1096  // Using directives are never dependent, so they require no explicit
1097
1098  UsingDirectiveDecl *Inst
1099    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1100                                 D->getNamespaceKeyLocation(),
1101                                 D->getQualifierRange(), D->getQualifier(),
1102                                 D->getIdentLocation(),
1103                                 D->getNominatedNamespace(),
1104                                 D->getCommonAncestor());
1105  Owner->addDecl(Inst);
1106  return Inst;
1107}
1108
1109Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1110  // The nested name specifier is non-dependent, so no transformation
1111  // is required.
1112
1113  // We only need to do redeclaration lookups if we're in a class
1114  // scope (in fact, it's not really even possible in non-class
1115  // scopes).
1116  bool CheckRedeclaration = Owner->isRecord();
1117
1118  LookupResult Prev(SemaRef, D->getDeclName(), D->getLocation(),
1119                    Sema::LookupUsingDeclName, Sema::ForRedeclaration);
1120
1121  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1122                                       D->getLocation(),
1123                                       D->getNestedNameRange(),
1124                                       D->getUsingLocation(),
1125                                       D->getTargetNestedNameDecl(),
1126                                       D->getDeclName(),
1127                                       D->isTypeName());
1128
1129  CXXScopeSpec SS;
1130  SS.setScopeRep(D->getTargetNestedNameDecl());
1131  SS.setRange(D->getNestedNameRange());
1132
1133  if (CheckRedeclaration) {
1134    Prev.setHideTags(false);
1135    SemaRef.LookupQualifiedName(Prev, Owner);
1136
1137    // Check for invalid redeclarations.
1138    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1139                                            D->isTypeName(), SS,
1140                                            D->getLocation(), Prev))
1141      NewUD->setInvalidDecl();
1142
1143  }
1144
1145  if (!NewUD->isInvalidDecl() &&
1146      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1147                                      D->getLocation()))
1148    NewUD->setInvalidDecl();
1149
1150  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1151  NewUD->setAccess(D->getAccess());
1152  Owner->addDecl(NewUD);
1153
1154  // Don't process the shadow decls for an invalid decl.
1155  if (NewUD->isInvalidDecl())
1156    return NewUD;
1157
1158  // Process the shadow decls.
1159  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1160         I != E; ++I) {
1161    UsingShadowDecl *Shadow = *I;
1162    NamedDecl *InstTarget =
1163      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getTargetDecl(),
1164                                                   TemplateArgs));
1165
1166    if (CheckRedeclaration &&
1167        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1168      continue;
1169
1170    UsingShadowDecl *InstShadow
1171      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1172    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1173  }
1174
1175  return NewUD;
1176}
1177
1178Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1179  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1180  return 0;
1181}
1182
1183Decl * TemplateDeclInstantiator
1184    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1185  NestedNameSpecifier *NNS =
1186    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1187                                     D->getTargetNestedNameRange(),
1188                                     TemplateArgs);
1189  if (!NNS)
1190    return 0;
1191
1192  CXXScopeSpec SS;
1193  SS.setRange(D->getTargetNestedNameRange());
1194  SS.setScopeRep(NNS);
1195
1196  NamedDecl *UD =
1197    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1198                                  D->getUsingLoc(), SS, D->getLocation(),
1199                                  D->getDeclName(), 0,
1200                                  /*instantiation*/ true,
1201                                  /*typename*/ true, D->getTypenameLoc());
1202  if (UD)
1203    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1204
1205  return UD;
1206}
1207
1208Decl * TemplateDeclInstantiator
1209    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1210  NestedNameSpecifier *NNS =
1211    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1212                                     D->getTargetNestedNameRange(),
1213                                     TemplateArgs);
1214  if (!NNS)
1215    return 0;
1216
1217  CXXScopeSpec SS;
1218  SS.setRange(D->getTargetNestedNameRange());
1219  SS.setScopeRep(NNS);
1220
1221  NamedDecl *UD =
1222    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1223                                  D->getUsingLoc(), SS, D->getLocation(),
1224                                  D->getDeclName(), 0,
1225                                  /*instantiation*/ true,
1226                                  /*typename*/ false, SourceLocation());
1227  if (UD)
1228    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1229
1230  return UD;
1231}
1232
1233Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1234                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1235  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1236  return Instantiator.Visit(D);
1237}
1238
1239/// \brief Instantiates a nested template parameter list in the current
1240/// instantiation context.
1241///
1242/// \param L The parameter list to instantiate
1243///
1244/// \returns NULL if there was an error
1245TemplateParameterList *
1246TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1247  // Get errors for all the parameters before bailing out.
1248  bool Invalid = false;
1249
1250  unsigned N = L->size();
1251  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1252  ParamVector Params;
1253  Params.reserve(N);
1254  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1255       PI != PE; ++PI) {
1256    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1257    Params.push_back(D);
1258    Invalid = Invalid || !D || D->isInvalidDecl();
1259  }
1260
1261  // Clean up if we had an error.
1262  if (Invalid) {
1263    for (ParamVector::iterator PI = Params.begin(), PE = Params.end();
1264         PI != PE; ++PI)
1265      if (*PI)
1266        (*PI)->Destroy(SemaRef.Context);
1267    return NULL;
1268  }
1269
1270  TemplateParameterList *InstL
1271    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1272                                    L->getLAngleLoc(), &Params.front(), N,
1273                                    L->getRAngleLoc());
1274  return InstL;
1275}
1276
1277/// \brief Instantiate the declaration of a class template partial
1278/// specialization.
1279///
1280/// \param ClassTemplate the (instantiated) class template that is partially
1281// specialized by the instantiation of \p PartialSpec.
1282///
1283/// \param PartialSpec the (uninstantiated) class template partial
1284/// specialization that we are instantiating.
1285///
1286/// \returns true if there was an error, false otherwise.
1287bool
1288TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1289                                            ClassTemplateDecl *ClassTemplate,
1290                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1291  // Create a local instantiation scope for this class template partial
1292  // specialization, which will contain the instantiations of the template
1293  // parameters.
1294  Sema::LocalInstantiationScope Scope(SemaRef);
1295
1296  // Substitute into the template parameters of the class template partial
1297  // specialization.
1298  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1299  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1300  if (!InstParams)
1301    return true;
1302
1303  // Substitute into the template arguments of the class template partial
1304  // specialization.
1305  const TemplateArgumentLoc *PartialSpecTemplateArgs
1306    = PartialSpec->getTemplateArgsAsWritten();
1307  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1308
1309  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1310  for (unsigned I = 0; I != N; ++I) {
1311    TemplateArgumentLoc Loc;
1312    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1313      return true;
1314    InstTemplateArgs.addArgument(Loc);
1315  }
1316
1317
1318  // Check that the template argument list is well-formed for this
1319  // class template.
1320  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1321                                        InstTemplateArgs.size());
1322  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1323                                        PartialSpec->getLocation(),
1324                                        InstTemplateArgs,
1325                                        false,
1326                                        Converted))
1327    return true;
1328
1329  // Figure out where to insert this class template partial specialization
1330  // in the member template's set of class template partial specializations.
1331  llvm::FoldingSetNodeID ID;
1332  ClassTemplatePartialSpecializationDecl::Profile(ID,
1333                                                  Converted.getFlatArguments(),
1334                                                  Converted.flatSize(),
1335                                                  SemaRef.Context);
1336  void *InsertPos = 0;
1337  ClassTemplateSpecializationDecl *PrevDecl
1338    = ClassTemplate->getPartialSpecializations().FindNodeOrInsertPos(ID,
1339                                                                     InsertPos);
1340
1341  // Build the canonical type that describes the converted template
1342  // arguments of the class template partial specialization.
1343  QualType CanonType
1344    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1345                                                  Converted.getFlatArguments(),
1346                                                    Converted.flatSize());
1347
1348  // Build the fully-sugared type for this class template
1349  // specialization as the user wrote in the specialization
1350  // itself. This means that we'll pretty-print the type retrieved
1351  // from the specialization's declaration the way that the user
1352  // actually wrote the specialization, rather than formatting the
1353  // name based on the "canonical" representation used to store the
1354  // template arguments in the specialization.
1355  QualType WrittenTy
1356    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1357                                                    InstTemplateArgs,
1358                                                    CanonType);
1359
1360  if (PrevDecl) {
1361    // We've already seen a partial specialization with the same template
1362    // parameters and template arguments. This can happen, for example, when
1363    // substituting the outer template arguments ends up causing two
1364    // class template partial specializations of a member class template
1365    // to have identical forms, e.g.,
1366    //
1367    //   template<typename T, typename U>
1368    //   struct Outer {
1369    //     template<typename X, typename Y> struct Inner;
1370    //     template<typename Y> struct Inner<T, Y>;
1371    //     template<typename Y> struct Inner<U, Y>;
1372    //   };
1373    //
1374    //   Outer<int, int> outer; // error: the partial specializations of Inner
1375    //                          // have the same signature.
1376    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1377      << WrittenTy;
1378    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1379      << SemaRef.Context.getTypeDeclType(PrevDecl);
1380    return true;
1381  }
1382
1383
1384  // Create the class template partial specialization declaration.
1385  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1386    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context, Owner,
1387                                                     PartialSpec->getLocation(),
1388                                                     InstParams,
1389                                                     ClassTemplate,
1390                                                     Converted,
1391                                                     InstTemplateArgs,
1392                                                     0);
1393  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1394  InstPartialSpec->setTypeAsWritten(WrittenTy);
1395
1396  // Add this partial specialization to the set of class template partial
1397  // specializations.
1398  ClassTemplate->getPartialSpecializations().InsertNode(InstPartialSpec,
1399                                                        InsertPos);
1400  return false;
1401}
1402
1403/// \brief Does substitution on the type of the given function, including
1404/// all of the function parameters.
1405///
1406/// \param D The function whose type will be the basis of the substitution
1407///
1408/// \param Params the instantiated parameter declarations
1409
1410/// \returns the instantiated function's type if successful, a NULL
1411/// type if there was an error.
1412QualType
1413TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1414                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1415  bool InvalidDecl = false;
1416
1417  // Substitute all of the function's formal parameter types.
1418  TemplateDeclInstantiator ParamInstantiator(SemaRef, 0, TemplateArgs);
1419  llvm::SmallVector<QualType, 4> ParamTys;
1420  for (FunctionDecl::param_iterator P = D->param_begin(),
1421                                 PEnd = D->param_end();
1422       P != PEnd; ++P) {
1423    if (ParmVarDecl *PInst = ParamInstantiator.VisitParmVarDecl(*P)) {
1424      if (PInst->getType()->isVoidType()) {
1425        SemaRef.Diag(PInst->getLocation(), diag::err_param_with_void_type);
1426        PInst->setInvalidDecl();
1427      } else if (SemaRef.RequireNonAbstractType(PInst->getLocation(),
1428                                                PInst->getType(),
1429                                                diag::err_abstract_type_in_decl,
1430                                                Sema::AbstractParamType))
1431        PInst->setInvalidDecl();
1432
1433      Params.push_back(PInst);
1434      ParamTys.push_back(PInst->getType());
1435
1436      if (PInst->isInvalidDecl())
1437        InvalidDecl = true;
1438    } else
1439      InvalidDecl = true;
1440  }
1441
1442  // FIXME: Deallocate dead declarations.
1443  if (InvalidDecl)
1444    return QualType();
1445
1446  const FunctionProtoType *Proto = D->getType()->getAs<FunctionProtoType>();
1447  assert(Proto && "Missing prototype?");
1448  QualType ResultType
1449    = SemaRef.SubstType(Proto->getResultType(), TemplateArgs,
1450                        D->getLocation(), D->getDeclName());
1451  if (ResultType.isNull())
1452    return QualType();
1453
1454  return SemaRef.BuildFunctionType(ResultType, ParamTys.data(), ParamTys.size(),
1455                                   Proto->isVariadic(), Proto->getTypeQuals(),
1456                                   D->getLocation(), D->getDeclName());
1457}
1458
1459/// \brief Initializes the common fields of an instantiation function
1460/// declaration (New) from the corresponding fields of its template (Tmpl).
1461///
1462/// \returns true if there was an error
1463bool
1464TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1465                                                    FunctionDecl *Tmpl) {
1466  if (Tmpl->isDeleted())
1467    New->setDeleted();
1468
1469  // If we are performing substituting explicitly-specified template arguments
1470  // or deduced template arguments into a function template and we reach this
1471  // point, we are now past the point where SFINAE applies and have committed
1472  // to keeping the new function template specialization. We therefore
1473  // convert the active template instantiation for the function template
1474  // into a template instantiation for this specific function template
1475  // specialization, which is not a SFINAE context, so that we diagnose any
1476  // further errors in the declaration itself.
1477  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1478  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1479  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1480      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1481    if (FunctionTemplateDecl *FunTmpl
1482          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1483      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1484             "Deduction from the wrong function template?");
1485      (void) FunTmpl;
1486      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1487      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1488      --SemaRef.NonInstantiationEntries;
1489    }
1490  }
1491
1492  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1493  assert(Proto && "Function template without prototype?");
1494
1495  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1496      Proto->getNoReturnAttr()) {
1497    // The function has an exception specification or a "noreturn"
1498    // attribute. Substitute into each of the exception types.
1499    llvm::SmallVector<QualType, 4> Exceptions;
1500    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1501      // FIXME: Poor location information!
1502      QualType T
1503        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1504                            New->getLocation(), New->getDeclName());
1505      if (T.isNull() ||
1506          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1507        continue;
1508
1509      Exceptions.push_back(T);
1510    }
1511
1512    // Rebuild the function type
1513
1514    const FunctionProtoType *NewProto
1515      = New->getType()->getAs<FunctionProtoType>();
1516    assert(NewProto && "Template instantiation without function prototype?");
1517    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1518                                                 NewProto->arg_type_begin(),
1519                                                 NewProto->getNumArgs(),
1520                                                 NewProto->isVariadic(),
1521                                                 NewProto->getTypeQuals(),
1522                                                 Proto->hasExceptionSpec(),
1523                                                 Proto->hasAnyExceptionSpec(),
1524                                                 Exceptions.size(),
1525                                                 Exceptions.data(),
1526                                                 Proto->getNoReturnAttr()));
1527  }
1528
1529  return false;
1530}
1531
1532/// \brief Initializes common fields of an instantiated method
1533/// declaration (New) from the corresponding fields of its template
1534/// (Tmpl).
1535///
1536/// \returns true if there was an error
1537bool
1538TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
1539                                                  CXXMethodDecl *Tmpl) {
1540  if (InitFunctionInstantiation(New, Tmpl))
1541    return true;
1542
1543  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
1544  New->setAccess(Tmpl->getAccess());
1545  if (Tmpl->isVirtualAsWritten())
1546    Record->setMethodAsVirtual(New);
1547
1548  // FIXME: attributes
1549  // FIXME: New needs a pointer to Tmpl
1550  return false;
1551}
1552
1553/// \brief Instantiate the definition of the given function from its
1554/// template.
1555///
1556/// \param PointOfInstantiation the point at which the instantiation was
1557/// required. Note that this is not precisely a "point of instantiation"
1558/// for the function, but it's close.
1559///
1560/// \param Function the already-instantiated declaration of a
1561/// function template specialization or member function of a class template
1562/// specialization.
1563///
1564/// \param Recursive if true, recursively instantiates any functions that
1565/// are required by this instantiation.
1566///
1567/// \param DefinitionRequired if true, then we are performing an explicit
1568/// instantiation where the body of the function is required. Complain if
1569/// there is no such body.
1570void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
1571                                         FunctionDecl *Function,
1572                                         bool Recursive,
1573                                         bool DefinitionRequired) {
1574  if (Function->isInvalidDecl())
1575    return;
1576
1577  assert(!Function->getBody() && "Already instantiated!");
1578
1579  // Never instantiate an explicit specialization.
1580  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
1581    return;
1582
1583  // Find the function body that we'll be substituting.
1584  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
1585  Stmt *Pattern = 0;
1586  if (PatternDecl)
1587    Pattern = PatternDecl->getBody(PatternDecl);
1588
1589  if (!Pattern) {
1590    if (DefinitionRequired) {
1591      if (Function->getPrimaryTemplate())
1592        Diag(PointOfInstantiation,
1593             diag::err_explicit_instantiation_undefined_func_template)
1594          << Function->getPrimaryTemplate();
1595      else
1596        Diag(PointOfInstantiation,
1597             diag::err_explicit_instantiation_undefined_member)
1598          << 1 << Function->getDeclName() << Function->getDeclContext();
1599
1600      if (PatternDecl)
1601        Diag(PatternDecl->getLocation(),
1602             diag::note_explicit_instantiation_here);
1603    }
1604
1605    return;
1606  }
1607
1608  // C++0x [temp.explicit]p9:
1609  //   Except for inline functions, other explicit instantiation declarations
1610  //   have the effect of suppressing the implicit instantiation of the entity
1611  //   to which they refer.
1612  if (Function->getTemplateSpecializationKind()
1613        == TSK_ExplicitInstantiationDeclaration &&
1614      !PatternDecl->isInlined())
1615    return;
1616
1617  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
1618  if (Inst)
1619    return;
1620
1621  // If we're performing recursive template instantiation, create our own
1622  // queue of pending implicit instantiations that we will instantiate later,
1623  // while we're still within our own instantiation context.
1624  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
1625  if (Recursive)
1626    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1627
1628  ActOnStartOfFunctionDef(0, DeclPtrTy::make(Function));
1629
1630  // Introduce a new scope where local variable instantiations will be
1631  // recorded.
1632  LocalInstantiationScope Scope(*this);
1633
1634  // Introduce the instantiated function parameters into the local
1635  // instantiation scope.
1636  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I)
1637    Scope.InstantiatedLocal(PatternDecl->getParamDecl(I),
1638                            Function->getParamDecl(I));
1639
1640  // Enter the scope of this instantiation. We don't use
1641  // PushDeclContext because we don't have a scope.
1642  DeclContext *PreviousContext = CurContext;
1643  CurContext = Function;
1644
1645  MultiLevelTemplateArgumentList TemplateArgs =
1646    getTemplateInstantiationArgs(Function);
1647
1648  // If this is a constructor, instantiate the member initializers.
1649  if (const CXXConstructorDecl *Ctor =
1650        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
1651    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
1652                               TemplateArgs);
1653  }
1654
1655  // Instantiate the function body.
1656  OwningStmtResult Body = SubstStmt(Pattern, TemplateArgs);
1657
1658  if (Body.isInvalid())
1659    Function->setInvalidDecl();
1660
1661  ActOnFinishFunctionBody(DeclPtrTy::make(Function), move(Body),
1662                          /*IsInstantiation=*/true);
1663
1664  CurContext = PreviousContext;
1665
1666  DeclGroupRef DG(Function);
1667  Consumer.HandleTopLevelDecl(DG);
1668
1669  if (Recursive) {
1670    // Instantiate any pending implicit instantiations found during the
1671    // instantiation of this template.
1672    PerformPendingImplicitInstantiations();
1673
1674    // Restore the set of pending implicit instantiations.
1675    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1676  }
1677}
1678
1679/// \brief Instantiate the definition of the given variable from its
1680/// template.
1681///
1682/// \param PointOfInstantiation the point at which the instantiation was
1683/// required. Note that this is not precisely a "point of instantiation"
1684/// for the function, but it's close.
1685///
1686/// \param Var the already-instantiated declaration of a static member
1687/// variable of a class template specialization.
1688///
1689/// \param Recursive if true, recursively instantiates any functions that
1690/// are required by this instantiation.
1691///
1692/// \param DefinitionRequired if true, then we are performing an explicit
1693/// instantiation where an out-of-line definition of the member variable
1694/// is required. Complain if there is no such definition.
1695void Sema::InstantiateStaticDataMemberDefinition(
1696                                          SourceLocation PointOfInstantiation,
1697                                                 VarDecl *Var,
1698                                                 bool Recursive,
1699                                                 bool DefinitionRequired) {
1700  if (Var->isInvalidDecl())
1701    return;
1702
1703  // Find the out-of-line definition of this static data member.
1704  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
1705  assert(Def && "This data member was not instantiated from a template?");
1706  assert(Def->isStaticDataMember() && "Not a static data member?");
1707  Def = Def->getOutOfLineDefinition();
1708
1709  if (!Def) {
1710    // We did not find an out-of-line definition of this static data member,
1711    // so we won't perform any instantiation. Rather, we rely on the user to
1712    // instantiate this definition (or provide a specialization for it) in
1713    // another translation unit.
1714    if (DefinitionRequired) {
1715      Def = Var->getInstantiatedFromStaticDataMember();
1716      Diag(PointOfInstantiation,
1717           diag::err_explicit_instantiation_undefined_member)
1718        << 2 << Var->getDeclName() << Var->getDeclContext();
1719      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
1720    }
1721
1722    return;
1723  }
1724
1725  // Never instantiate an explicit specialization.
1726  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
1727    return;
1728
1729  // C++0x [temp.explicit]p9:
1730  //   Except for inline functions, other explicit instantiation declarations
1731  //   have the effect of suppressing the implicit instantiation of the entity
1732  //   to which they refer.
1733  if (Var->getTemplateSpecializationKind()
1734        == TSK_ExplicitInstantiationDeclaration)
1735    return;
1736
1737  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
1738  if (Inst)
1739    return;
1740
1741  // If we're performing recursive template instantiation, create our own
1742  // queue of pending implicit instantiations that we will instantiate later,
1743  // while we're still within our own instantiation context.
1744  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
1745  if (Recursive)
1746    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1747
1748  // Enter the scope of this instantiation. We don't use
1749  // PushDeclContext because we don't have a scope.
1750  DeclContext *PreviousContext = CurContext;
1751  CurContext = Var->getDeclContext();
1752
1753  VarDecl *OldVar = Var;
1754  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
1755                                          getTemplateInstantiationArgs(Var)));
1756  CurContext = PreviousContext;
1757
1758  if (Var) {
1759    Var->setPreviousDeclaration(OldVar);
1760    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
1761    assert(MSInfo && "Missing member specialization information?");
1762    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
1763                                       MSInfo->getPointOfInstantiation());
1764    DeclGroupRef DG(Var);
1765    Consumer.HandleTopLevelDecl(DG);
1766  }
1767
1768  if (Recursive) {
1769    // Instantiate any pending implicit instantiations found during the
1770    // instantiation of this template.
1771    PerformPendingImplicitInstantiations();
1772
1773    // Restore the set of pending implicit instantiations.
1774    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1775  }
1776}
1777
1778void
1779Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
1780                                 const CXXConstructorDecl *Tmpl,
1781                           const MultiLevelTemplateArgumentList &TemplateArgs) {
1782
1783  llvm::SmallVector<MemInitTy*, 4> NewInits;
1784
1785  // Instantiate all the initializers.
1786  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
1787                                            InitsEnd = Tmpl->init_end();
1788       Inits != InitsEnd; ++Inits) {
1789    CXXBaseOrMemberInitializer *Init = *Inits;
1790
1791    ASTOwningVector<&ActionBase::DeleteExpr> NewArgs(*this);
1792
1793    // Instantiate all the arguments.
1794    for (ExprIterator Args = Init->arg_begin(), ArgsEnd = Init->arg_end();
1795         Args != ArgsEnd; ++Args) {
1796      OwningExprResult NewArg = SubstExpr(*Args, TemplateArgs);
1797
1798      if (NewArg.isInvalid())
1799        New->setInvalidDecl();
1800      else
1801        NewArgs.push_back(NewArg.takeAs<Expr>());
1802    }
1803
1804    MemInitResult NewInit;
1805
1806    if (Init->isBaseInitializer()) {
1807      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
1808                                            TemplateArgs,
1809                                            Init->getSourceLocation(),
1810                                            New->getDeclName());
1811      if (!BaseTInfo) {
1812        New->setInvalidDecl();
1813        continue;
1814      }
1815
1816      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
1817                                     (Expr **)NewArgs.data(),
1818                                     NewArgs.size(),
1819                                     Init->getLParenLoc(),
1820                                     Init->getRParenLoc(),
1821                                     New->getParent());
1822    } else if (Init->isMemberInitializer()) {
1823      FieldDecl *Member;
1824
1825      // Is this an anonymous union?
1826      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
1827        Member = cast<FieldDecl>(FindInstantiatedDecl(UnionInit, TemplateArgs));
1828      else
1829        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMember(),
1830                                                      TemplateArgs));
1831
1832      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
1833                                       NewArgs.size(),
1834                                       Init->getSourceLocation(),
1835                                       Init->getLParenLoc(),
1836                                       Init->getRParenLoc());
1837    }
1838
1839    if (NewInit.isInvalid())
1840      New->setInvalidDecl();
1841    else {
1842      // FIXME: It would be nice if ASTOwningVector had a release function.
1843      NewArgs.take();
1844
1845      NewInits.push_back((MemInitTy *)NewInit.get());
1846    }
1847  }
1848
1849  // Assign all the initializers to the new constructor.
1850  ActOnMemInitializers(DeclPtrTy::make(New),
1851                       /*FIXME: ColonLoc */
1852                       SourceLocation(),
1853                       NewInits.data(), NewInits.size());
1854}
1855
1856// TODO: this could be templated if the various decl types used the
1857// same method name.
1858static bool isInstantiationOf(ClassTemplateDecl *Pattern,
1859                              ClassTemplateDecl *Instance) {
1860  Pattern = Pattern->getCanonicalDecl();
1861
1862  do {
1863    Instance = Instance->getCanonicalDecl();
1864    if (Pattern == Instance) return true;
1865    Instance = Instance->getInstantiatedFromMemberTemplate();
1866  } while (Instance);
1867
1868  return false;
1869}
1870
1871static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
1872                              FunctionTemplateDecl *Instance) {
1873  Pattern = Pattern->getCanonicalDecl();
1874
1875  do {
1876    Instance = Instance->getCanonicalDecl();
1877    if (Pattern == Instance) return true;
1878    Instance = Instance->getInstantiatedFromMemberTemplate();
1879  } while (Instance);
1880
1881  return false;
1882}
1883
1884static bool
1885isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
1886                  ClassTemplatePartialSpecializationDecl *Instance) {
1887  Pattern
1888    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
1889  do {
1890    Instance = cast<ClassTemplatePartialSpecializationDecl>(
1891                                                Instance->getCanonicalDecl());
1892    if (Pattern == Instance)
1893      return true;
1894    Instance = Instance->getInstantiatedFromMember();
1895  } while (Instance);
1896
1897  return false;
1898}
1899
1900static bool isInstantiationOf(CXXRecordDecl *Pattern,
1901                              CXXRecordDecl *Instance) {
1902  Pattern = Pattern->getCanonicalDecl();
1903
1904  do {
1905    Instance = Instance->getCanonicalDecl();
1906    if (Pattern == Instance) return true;
1907    Instance = Instance->getInstantiatedFromMemberClass();
1908  } while (Instance);
1909
1910  return false;
1911}
1912
1913static bool isInstantiationOf(FunctionDecl *Pattern,
1914                              FunctionDecl *Instance) {
1915  Pattern = Pattern->getCanonicalDecl();
1916
1917  do {
1918    Instance = Instance->getCanonicalDecl();
1919    if (Pattern == Instance) return true;
1920    Instance = Instance->getInstantiatedFromMemberFunction();
1921  } while (Instance);
1922
1923  return false;
1924}
1925
1926static bool isInstantiationOf(EnumDecl *Pattern,
1927                              EnumDecl *Instance) {
1928  Pattern = Pattern->getCanonicalDecl();
1929
1930  do {
1931    Instance = Instance->getCanonicalDecl();
1932    if (Pattern == Instance) return true;
1933    Instance = Instance->getInstantiatedFromMemberEnum();
1934  } while (Instance);
1935
1936  return false;
1937}
1938
1939static bool isInstantiationOf(UsingShadowDecl *Pattern,
1940                              UsingShadowDecl *Instance,
1941                              ASTContext &C) {
1942  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
1943}
1944
1945static bool isInstantiationOf(UsingDecl *Pattern,
1946                              UsingDecl *Instance,
1947                              ASTContext &C) {
1948  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
1949}
1950
1951static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
1952                              UsingDecl *Instance,
1953                              ASTContext &C) {
1954  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
1955}
1956
1957static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
1958                              UsingDecl *Instance,
1959                              ASTContext &C) {
1960  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
1961}
1962
1963static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
1964                                              VarDecl *Instance) {
1965  assert(Instance->isStaticDataMember());
1966
1967  Pattern = Pattern->getCanonicalDecl();
1968
1969  do {
1970    Instance = Instance->getCanonicalDecl();
1971    if (Pattern == Instance) return true;
1972    Instance = Instance->getInstantiatedFromStaticDataMember();
1973  } while (Instance);
1974
1975  return false;
1976}
1977
1978// Other is the prospective instantiation
1979// D is the prospective pattern
1980static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
1981  if (D->getKind() != Other->getKind()) {
1982    if (UnresolvedUsingTypenameDecl *UUD
1983          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
1984      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
1985        return isInstantiationOf(UUD, UD, Ctx);
1986      }
1987    }
1988
1989    if (UnresolvedUsingValueDecl *UUD
1990          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
1991      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
1992        return isInstantiationOf(UUD, UD, Ctx);
1993      }
1994    }
1995
1996    return false;
1997  }
1998
1999  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2000    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2001
2002  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2003    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2004
2005  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2006    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2007
2008  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2009    if (Var->isStaticDataMember())
2010      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2011
2012  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2013    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2014
2015  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2016    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2017
2018  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2019        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2020    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2021                             PartialSpec);
2022
2023  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2024    if (!Field->getDeclName()) {
2025      // This is an unnamed field.
2026      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2027        cast<FieldDecl>(D);
2028    }
2029  }
2030
2031  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2032    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2033
2034  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2035    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2036
2037  return D->getDeclName() && isa<NamedDecl>(Other) &&
2038    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2039}
2040
2041template<typename ForwardIterator>
2042static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2043                                      NamedDecl *D,
2044                                      ForwardIterator first,
2045                                      ForwardIterator last) {
2046  for (; first != last; ++first)
2047    if (isInstantiationOf(Ctx, D, *first))
2048      return cast<NamedDecl>(*first);
2049
2050  return 0;
2051}
2052
2053/// \brief Finds the instantiation of the given declaration context
2054/// within the current instantiation.
2055///
2056/// \returns NULL if there was an error
2057DeclContext *Sema::FindInstantiatedContext(DeclContext* DC,
2058                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2059  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2060    Decl* ID = FindInstantiatedDecl(D, TemplateArgs);
2061    return cast_or_null<DeclContext>(ID);
2062  } else return DC;
2063}
2064
2065/// \brief Find the instantiation of the given declaration within the
2066/// current instantiation.
2067///
2068/// This routine is intended to be used when \p D is a declaration
2069/// referenced from within a template, that needs to mapped into the
2070/// corresponding declaration within an instantiation. For example,
2071/// given:
2072///
2073/// \code
2074/// template<typename T>
2075/// struct X {
2076///   enum Kind {
2077///     KnownValue = sizeof(T)
2078///   };
2079///
2080///   bool getKind() const { return KnownValue; }
2081/// };
2082///
2083/// template struct X<int>;
2084/// \endcode
2085///
2086/// In the instantiation of X<int>::getKind(), we need to map the
2087/// EnumConstantDecl for KnownValue (which refers to
2088/// X<T>::<Kind>::KnownValue) to its instantiation
2089/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2090/// this mapping from within the instantiation of X<int>.
2091NamedDecl *Sema::FindInstantiatedDecl(NamedDecl *D,
2092                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2093  DeclContext *ParentDC = D->getDeclContext();
2094  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2095      isa<TemplateTypeParmDecl>(D) || isa<TemplateTypeParmDecl>(D) ||
2096      ParentDC->isFunctionOrMethod()) {
2097    // D is a local of some kind. Look into the map of local
2098    // declarations to their instantiations.
2099    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2100  }
2101
2102  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2103    if (!Record->isDependentContext())
2104      return D;
2105
2106    // If the RecordDecl is actually the injected-class-name or a "templated"
2107    // declaration for a class template or class template partial
2108    // specialization, substitute into the injected-class-name of the
2109    // class template or partial specialization to find the new DeclContext.
2110    QualType T;
2111    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2112
2113    if (ClassTemplate) {
2114      T = ClassTemplate->getInjectedClassNameType(Context);
2115    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2116                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2117      T = Context.getTypeDeclType(Record);
2118      ClassTemplate = PartialSpec->getSpecializedTemplate();
2119    }
2120
2121    if (!T.isNull()) {
2122      // Substitute into the injected-class-name to get the type corresponding
2123      // to the instantiation we want. This substitution should never fail,
2124      // since we know we can instantiate the injected-class-name or we wouldn't
2125      // have gotten to the injected-class-name!
2126      // FIXME: Can we use the CurrentInstantiationScope to avoid this extra
2127      // instantiation in the common case?
2128      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2129      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2130
2131      if (!T->isDependentType()) {
2132        assert(T->isRecordType() && "Instantiation must produce a record type");
2133        return T->getAs<RecordType>()->getDecl();
2134      }
2135
2136      // We are performing "partial" template instantiation to create the
2137      // member declarations for the members of a class template
2138      // specialization. Therefore, D is actually referring to something in
2139      // the current instantiation. Look through the current context,
2140      // which contains actual instantiations, to find the instantiation of
2141      // the "current instantiation" that D refers to.
2142      for (DeclContext *DC = CurContext; !DC->isFileContext();
2143           DC = DC->getParent()) {
2144        if (ClassTemplateSpecializationDecl *Spec
2145              = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2146          if (isInstantiationOf(ClassTemplate,
2147                                Spec->getSpecializedTemplate()))
2148            return Spec;
2149      }
2150
2151      assert(false &&
2152             "Unable to find declaration for the current instantiation");
2153      return Record;
2154    }
2155
2156    // Fall through to deal with other dependent record types (e.g.,
2157    // anonymous unions in class templates).
2158  }
2159
2160  if (!ParentDC->isDependentContext())
2161    return D;
2162
2163  ParentDC = FindInstantiatedContext(ParentDC, TemplateArgs);
2164  if (!ParentDC)
2165    return 0;
2166
2167  if (ParentDC != D->getDeclContext()) {
2168    // We performed some kind of instantiation in the parent context,
2169    // so now we need to look into the instantiated parent context to
2170    // find the instantiation of the declaration D.
2171    NamedDecl *Result = 0;
2172    if (D->getDeclName()) {
2173      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2174      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2175    } else {
2176      // Since we don't have a name for the entity we're looking for,
2177      // our only option is to walk through all of the declarations to
2178      // find that name. This will occur in a few cases:
2179      //
2180      //   - anonymous struct/union within a template
2181      //   - unnamed class/struct/union/enum within a template
2182      //
2183      // FIXME: Find a better way to find these instantiations!
2184      Result = findInstantiationOf(Context, D,
2185                                   ParentDC->decls_begin(),
2186                                   ParentDC->decls_end());
2187    }
2188
2189    // UsingShadowDecls can instantiate to nothing because of using hiding.
2190    assert((Result || isa<UsingShadowDecl>(D))
2191           && "Unable to find instantiation of declaration!");
2192
2193    D = Result;
2194  }
2195
2196  return D;
2197}
2198
2199/// \brief Performs template instantiation for all implicit template
2200/// instantiations we have seen until this point.
2201void Sema::PerformPendingImplicitInstantiations() {
2202  while (!PendingImplicitInstantiations.empty()) {
2203    PendingImplicitInstantiation Inst = PendingImplicitInstantiations.front();
2204    PendingImplicitInstantiations.pop_front();
2205
2206    // Instantiate function definitions
2207    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2208      PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Function),
2209                                            Function->getLocation(), *this,
2210                                            Context.getSourceManager(),
2211                                           "instantiating function definition");
2212
2213      if (!Function->getBody())
2214        InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true);
2215      continue;
2216    }
2217
2218    // Instantiate static data member definitions.
2219    VarDecl *Var = cast<VarDecl>(Inst.first);
2220    assert(Var->isStaticDataMember() && "Not a static data member?");
2221
2222    PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Var),
2223                                          Var->getLocation(), *this,
2224                                          Context.getSourceManager(),
2225                                          "instantiating static data member "
2226                                          "definition");
2227
2228    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true);
2229  }
2230}
2231