SemaTemplateInstantiateDecl.cpp revision 67bee8199b79de7be7cb5cc05389176749c270b7 
1//===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//===----------------------------------------------------------------------===/
8//
9//  This file implements C++ template instantiation for declarations.
10//
11//===----------------------------------------------------------------------===/
12#include "clang/Sema/SemaInternal.h"
13#include "clang/Sema/Lookup.h"
14#include "clang/Sema/PrettyDeclStackTrace.h"
15#include "clang/Sema/Template.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/DeclTemplate.h"
19#include "clang/AST/DeclVisitor.h"
20#include "clang/AST/DependentDiagnostic.h"
21#include "clang/AST/Expr.h"
22#include "clang/AST/ExprCXX.h"
23#include "clang/AST/TypeLoc.h"
24#include "clang/Lex/Preprocessor.h"
25
26using namespace clang;
27
28namespace {
29  class TemplateDeclInstantiator
30    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
31    Sema &SemaRef;
32    DeclContext *Owner;
33    const MultiLevelTemplateArgumentList &TemplateArgs;
34
35  public:
36    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
37                             const MultiLevelTemplateArgumentList &TemplateArgs)
38      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
39
40    // FIXME: Once we get closer to completion, replace these manually-written
41    // declarations with automatically-generated ones from
42    // clang/AST/DeclNodes.inc.
43    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
44    Decl *VisitNamespaceDecl(NamespaceDecl *D);
45    Decl *VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
46    Decl *VisitTypedefDecl(TypedefDecl *D);
47    Decl *VisitVarDecl(VarDecl *D);
48    Decl *VisitAccessSpecDecl(AccessSpecDecl *D);
49    Decl *VisitFieldDecl(FieldDecl *D);
50    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
51    Decl *VisitEnumDecl(EnumDecl *D);
52    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
53    Decl *VisitFriendDecl(FriendDecl *D);
54    Decl *VisitFunctionDecl(FunctionDecl *D,
55                            TemplateParameterList *TemplateParams = 0);
56    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
57    Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
58                             TemplateParameterList *TemplateParams = 0);
59    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
60    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
61    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
62    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
63    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
64    Decl *VisitClassTemplatePartialSpecializationDecl(
65                                    ClassTemplatePartialSpecializationDecl *D);
66    Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
67    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
68    Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
69    Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
70    Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
71    Decl *VisitUsingDecl(UsingDecl *D);
72    Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
73    Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
74    Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
75
76    // Base case. FIXME: Remove once we can instantiate everything.
77    Decl *VisitDecl(Decl *D) {
78      unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
79                                                            Diagnostic::Error,
80                                                   "cannot instantiate %0 yet");
81      SemaRef.Diag(D->getLocation(), DiagID)
82        << D->getDeclKindName();
83
84      return 0;
85    }
86
87    // Helper functions for instantiating methods.
88    TypeSourceInfo *SubstFunctionType(FunctionDecl *D,
89                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
90    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
91    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
92
93    TemplateParameterList *
94      SubstTemplateParams(TemplateParameterList *List);
95
96    bool SubstQualifier(const DeclaratorDecl *OldDecl,
97                        DeclaratorDecl *NewDecl);
98    bool SubstQualifier(const TagDecl *OldDecl,
99                        TagDecl *NewDecl);
100
101    bool InstantiateClassTemplatePartialSpecialization(
102                                              ClassTemplateDecl *ClassTemplate,
103                           ClassTemplatePartialSpecializationDecl *PartialSpec);
104  };
105}
106
107bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
108                                              DeclaratorDecl *NewDecl) {
109  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
110  if (!OldQual) return false;
111
112  SourceRange QualRange = OldDecl->getQualifierRange();
113
114  NestedNameSpecifier *NewQual
115    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
116  if (!NewQual)
117    return true;
118
119  NewDecl->setQualifierInfo(NewQual, QualRange);
120  return false;
121}
122
123bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
124                                              TagDecl *NewDecl) {
125  NestedNameSpecifier *OldQual = OldDecl->getQualifier();
126  if (!OldQual) return false;
127
128  SourceRange QualRange = OldDecl->getQualifierRange();
129
130  NestedNameSpecifier *NewQual
131    = SemaRef.SubstNestedNameSpecifier(OldQual, QualRange, TemplateArgs);
132  if (!NewQual)
133    return true;
134
135  NewDecl->setQualifierInfo(NewQual, QualRange);
136  return false;
137}
138
139// FIXME: Is this still too simple?
140void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
141                            Decl *Tmpl, Decl *New) {
142  for (AttrVec::const_iterator i = Tmpl->attr_begin(), e = Tmpl->attr_end();
143       i != e; ++i) {
144    const Attr *TmplAttr = *i;
145    // FIXME: This should be generalized to more than just the AlignedAttr.
146    if (const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr)) {
147      if (Aligned->isAlignmentDependent()) {
148        // The alignment expression is not potentially evaluated.
149        EnterExpressionEvaluationContext Unevaluated(*this,
150                                                     Sema::Unevaluated);
151
152        if (Aligned->isAlignmentExpr()) {
153          ExprResult Result = SubstExpr(Aligned->getAlignmentExpr(),
154                                              TemplateArgs);
155          if (!Result.isInvalid())
156            AddAlignedAttr(Aligned->getLocation(), New, Result.takeAs<Expr>());
157        }
158        else {
159          TypeSourceInfo *Result = SubstType(Aligned->getAlignmentType(),
160                                              TemplateArgs,
161                                              Aligned->getLocation(),
162                                              DeclarationName());
163          if (Result)
164            AddAlignedAttr(Aligned->getLocation(), New, Result);
165        }
166        continue;
167      }
168    }
169
170    // FIXME: Is cloning correct for all attributes?
171    Attr *NewAttr = TmplAttr->clone(Context);
172    New->addAttr(NewAttr);
173  }
174}
175
176Decl *
177TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
178  assert(false && "Translation units cannot be instantiated");
179  return D;
180}
181
182Decl *
183TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
184  assert(false && "Namespaces cannot be instantiated");
185  return D;
186}
187
188Decl *
189TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
190  NamespaceAliasDecl *Inst
191    = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
192                                 D->getNamespaceLoc(),
193                                 D->getAliasLoc(),
194                                 D->getNamespace()->getIdentifier(),
195                                 D->getQualifierRange(),
196                                 D->getQualifier(),
197                                 D->getTargetNameLoc(),
198                                 D->getNamespace());
199  Owner->addDecl(Inst);
200  return Inst;
201}
202
203Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
204  bool Invalid = false;
205  TypeSourceInfo *DI = D->getTypeSourceInfo();
206  if (DI->getType()->isDependentType() ||
207      DI->getType()->isVariablyModifiedType()) {
208    DI = SemaRef.SubstType(DI, TemplateArgs,
209                           D->getLocation(), D->getDeclName());
210    if (!DI) {
211      Invalid = true;
212      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
213    }
214  } else {
215    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
216  }
217
218  // Create the new typedef
219  TypedefDecl *Typedef
220    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
221                          D->getIdentifier(), DI);
222  if (Invalid)
223    Typedef->setInvalidDecl();
224
225  if (const TagType *TT = DI->getType()->getAs<TagType>()) {
226    TagDecl *TD = TT->getDecl();
227
228    // If the TagDecl that the TypedefDecl points to is an anonymous decl
229    // keep track of the TypedefDecl.
230    if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl())
231      TD->setTypedefForAnonDecl(Typedef);
232  }
233
234  if (TypedefDecl *Prev = D->getPreviousDeclaration()) {
235    NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
236                                                       TemplateArgs);
237    Typedef->setPreviousDeclaration(cast<TypedefDecl>(InstPrev));
238  }
239
240  SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef);
241
242  Typedef->setAccess(D->getAccess());
243  Owner->addDecl(Typedef);
244
245  return Typedef;
246}
247
248/// \brief Instantiate the arguments provided as part of initialization.
249///
250/// \returns true if an error occurred, false otherwise.
251static bool InstantiateInitializationArguments(Sema &SemaRef,
252                                               Expr **Args, unsigned NumArgs,
253                           const MultiLevelTemplateArgumentList &TemplateArgs,
254                         llvm::SmallVectorImpl<SourceLocation> &FakeCommaLocs,
255                           ASTOwningVector<Expr*> &InitArgs) {
256  for (unsigned I = 0; I != NumArgs; ++I) {
257    // When we hit the first defaulted argument, break out of the loop:
258    // we don't pass those default arguments on.
259    if (Args[I]->isDefaultArgument())
260      break;
261
262    ExprResult Arg = SemaRef.SubstExpr(Args[I], TemplateArgs);
263    if (Arg.isInvalid())
264      return true;
265
266    Expr *ArgExpr = (Expr *)Arg.get();
267    InitArgs.push_back(Arg.release());
268
269    // FIXME: We're faking all of the comma locations. Do we need them?
270    FakeCommaLocs.push_back(
271                          SemaRef.PP.getLocForEndOfToken(ArgExpr->getLocEnd()));
272  }
273
274  return false;
275}
276
277/// \brief Instantiate an initializer, breaking it into separate
278/// initialization arguments.
279///
280/// \param S The semantic analysis object.
281///
282/// \param Init The initializer to instantiate.
283///
284/// \param TemplateArgs Template arguments to be substituted into the
285/// initializer.
286///
287/// \param NewArgs Will be filled in with the instantiation arguments.
288///
289/// \returns true if an error occurred, false otherwise
290static bool InstantiateInitializer(Sema &S, Expr *Init,
291                            const MultiLevelTemplateArgumentList &TemplateArgs,
292                                   SourceLocation &LParenLoc,
293                               llvm::SmallVector<SourceLocation, 4> &CommaLocs,
294                             ASTOwningVector<Expr*> &NewArgs,
295                                   SourceLocation &RParenLoc) {
296  NewArgs.clear();
297  LParenLoc = SourceLocation();
298  RParenLoc = SourceLocation();
299
300  if (!Init)
301    return false;
302
303  if (CXXExprWithTemporaries *ExprTemp = dyn_cast<CXXExprWithTemporaries>(Init))
304    Init = ExprTemp->getSubExpr();
305
306  while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init))
307    Init = Binder->getSubExpr();
308
309  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init))
310    Init = ICE->getSubExprAsWritten();
311
312  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
313    LParenLoc = ParenList->getLParenLoc();
314    RParenLoc = ParenList->getRParenLoc();
315    return InstantiateInitializationArguments(S, ParenList->getExprs(),
316                                              ParenList->getNumExprs(),
317                                              TemplateArgs, CommaLocs,
318                                              NewArgs);
319  }
320
321  if (CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) {
322    if (!isa<CXXTemporaryObjectExpr>(Construct)) {
323      if (InstantiateInitializationArguments(S,
324                                             Construct->getArgs(),
325                                             Construct->getNumArgs(),
326                                             TemplateArgs,
327                                             CommaLocs, NewArgs))
328        return true;
329
330      // FIXME: Fake locations!
331      LParenLoc = S.PP.getLocForEndOfToken(Init->getLocStart());
332      RParenLoc = CommaLocs.empty()? LParenLoc : CommaLocs.back();
333      return false;
334    }
335  }
336
337  ExprResult Result = S.SubstExpr(Init, TemplateArgs);
338  if (Result.isInvalid())
339    return true;
340
341  NewArgs.push_back(Result.takeAs<Expr>());
342  return false;
343}
344
345Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
346  // If this is the variable for an anonymous struct or union,
347  // instantiate the anonymous struct/union type first.
348  if (const RecordType *RecordTy = D->getType()->getAs<RecordType>())
349    if (RecordTy->getDecl()->isAnonymousStructOrUnion())
350      if (!VisitCXXRecordDecl(cast<CXXRecordDecl>(RecordTy->getDecl())))
351        return 0;
352
353  // Do substitution on the type of the declaration
354  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(),
355                                         TemplateArgs,
356                                         D->getTypeSpecStartLoc(),
357                                         D->getDeclName());
358  if (!DI)
359    return 0;
360
361  // Build the instantiated declaration
362  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
363                                 D->getLocation(), D->getIdentifier(),
364                                 DI->getType(), DI,
365                                 D->getStorageClass(),
366                                 D->getStorageClassAsWritten());
367  Var->setThreadSpecified(D->isThreadSpecified());
368  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
369
370  // Substitute the nested name specifier, if any.
371  if (SubstQualifier(D, Var))
372    return 0;
373
374  // If we are instantiating a static data member defined
375  // out-of-line, the instantiation will have the same lexical
376  // context (which will be a namespace scope) as the template.
377  if (D->isOutOfLine())
378    Var->setLexicalDeclContext(D->getLexicalDeclContext());
379
380  Var->setAccess(D->getAccess());
381
382  if (!D->isStaticDataMember())
383    Var->setUsed(D->isUsed(false));
384
385  // FIXME: In theory, we could have a previous declaration for variables that
386  // are not static data members.
387  bool Redeclaration = false;
388  // FIXME: having to fake up a LookupResult is dumb.
389  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(),
390                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
391  if (D->isStaticDataMember())
392    SemaRef.LookupQualifiedName(Previous, Owner, false);
393  SemaRef.CheckVariableDeclaration(Var, Previous, Redeclaration);
394
395  if (D->isOutOfLine()) {
396    if (!D->isStaticDataMember())
397      D->getLexicalDeclContext()->addDecl(Var);
398    Owner->makeDeclVisibleInContext(Var);
399  } else {
400    Owner->addDecl(Var);
401    if (Owner->isFunctionOrMethod())
402      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Var);
403  }
404  SemaRef.InstantiateAttrs(TemplateArgs, D, Var);
405
406  // Link instantiations of static data members back to the template from
407  // which they were instantiated.
408  if (Var->isStaticDataMember())
409    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D,
410                                                     TSK_ImplicitInstantiation);
411
412  if (Var->getAnyInitializer()) {
413    // We already have an initializer in the class.
414  } else if (D->getInit()) {
415    if (Var->isStaticDataMember() && !D->isOutOfLine())
416      SemaRef.PushExpressionEvaluationContext(Sema::Unevaluated);
417    else
418      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
419
420    // Instantiate the initializer.
421    SourceLocation LParenLoc, RParenLoc;
422    llvm::SmallVector<SourceLocation, 4> CommaLocs;
423    ASTOwningVector<Expr*> InitArgs(SemaRef);
424    if (!InstantiateInitializer(SemaRef, D->getInit(), TemplateArgs, LParenLoc,
425                                CommaLocs, InitArgs, RParenLoc)) {
426      // Attach the initializer to the declaration.
427      if (D->hasCXXDirectInitializer()) {
428        // Add the direct initializer to the declaration.
429        SemaRef.AddCXXDirectInitializerToDecl(Var,
430                                              LParenLoc,
431                                              move_arg(InitArgs),
432                                              CommaLocs.data(),
433                                              RParenLoc);
434      } else if (InitArgs.size() == 1) {
435        Expr *Init = InitArgs.take()[0];
436        SemaRef.AddInitializerToDecl(Var, Init, false);
437      } else {
438        assert(InitArgs.size() == 0);
439        SemaRef.ActOnUninitializedDecl(Var, false);
440      }
441    } else {
442      // FIXME: Not too happy about invalidating the declaration
443      // because of a bogus initializer.
444      Var->setInvalidDecl();
445    }
446
447    SemaRef.PopExpressionEvaluationContext();
448  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
449    SemaRef.ActOnUninitializedDecl(Var, false);
450
451  // Diagnose unused local variables.
452  if (!Var->isInvalidDecl() && Owner->isFunctionOrMethod() && !Var->isUsed())
453    SemaRef.DiagnoseUnusedDecl(Var);
454
455  return Var;
456}
457
458Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
459  AccessSpecDecl* AD
460    = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
461                             D->getAccessSpecifierLoc(), D->getColonLoc());
462  Owner->addHiddenDecl(AD);
463  return AD;
464}
465
466Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
467  bool Invalid = false;
468  TypeSourceInfo *DI = D->getTypeSourceInfo();
469  if (DI->getType()->isDependentType() ||
470      DI->getType()->isVariablyModifiedType())  {
471    DI = SemaRef.SubstType(DI, TemplateArgs,
472                           D->getLocation(), D->getDeclName());
473    if (!DI) {
474      DI = D->getTypeSourceInfo();
475      Invalid = true;
476    } else if (DI->getType()->isFunctionType()) {
477      // C++ [temp.arg.type]p3:
478      //   If a declaration acquires a function type through a type
479      //   dependent on a template-parameter and this causes a
480      //   declaration that does not use the syntactic form of a
481      //   function declarator to have function type, the program is
482      //   ill-formed.
483      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
484        << DI->getType();
485      Invalid = true;
486    }
487  } else {
488    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
489  }
490
491  Expr *BitWidth = D->getBitWidth();
492  if (Invalid)
493    BitWidth = 0;
494  else if (BitWidth) {
495    // The bit-width expression is not potentially evaluated.
496    EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
497
498    ExprResult InstantiatedBitWidth
499      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
500    if (InstantiatedBitWidth.isInvalid()) {
501      Invalid = true;
502      BitWidth = 0;
503    } else
504      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
505  }
506
507  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
508                                            DI->getType(), DI,
509                                            cast<RecordDecl>(Owner),
510                                            D->getLocation(),
511                                            D->isMutable(),
512                                            BitWidth,
513                                            D->getTypeSpecStartLoc(),
514                                            D->getAccess(),
515                                            0);
516  if (!Field) {
517    cast<Decl>(Owner)->setInvalidDecl();
518    return 0;
519  }
520
521  SemaRef.InstantiateAttrs(TemplateArgs, D, Field);
522
523  if (Invalid)
524    Field->setInvalidDecl();
525
526  if (!Field->getDeclName()) {
527    // Keep track of where this decl came from.
528    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
529  }
530  if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
531    if (Parent->isAnonymousStructOrUnion() &&
532        Parent->getLookupContext()->isFunctionOrMethod())
533      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
534  }
535
536  Field->setImplicit(D->isImplicit());
537  Field->setAccess(D->getAccess());
538  Owner->addDecl(Field);
539
540  return Field;
541}
542
543Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
544  // Handle friend type expressions by simply substituting template
545  // parameters into the pattern type and checking the result.
546  if (TypeSourceInfo *Ty = D->getFriendType()) {
547    TypeSourceInfo *InstTy =
548      SemaRef.SubstType(Ty, TemplateArgs,
549                        D->getLocation(), DeclarationName());
550    if (!InstTy)
551      return 0;
552
553    FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getFriendLoc(), InstTy);
554    if (!FD)
555      return 0;
556
557    FD->setAccess(AS_public);
558    Owner->addDecl(FD);
559    return FD;
560  }
561
562  NamedDecl *ND = D->getFriendDecl();
563  assert(ND && "friend decl must be a decl or a type!");
564
565  // All of the Visit implementations for the various potential friend
566  // declarations have to be carefully written to work for friend
567  // objects, with the most important detail being that the target
568  // decl should almost certainly not be placed in Owner.
569  Decl *NewND = Visit(ND);
570  if (!NewND) return 0;
571
572  FriendDecl *FD =
573    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
574                       cast<NamedDecl>(NewND), D->getFriendLoc());
575  FD->setAccess(AS_public);
576  Owner->addDecl(FD);
577  return FD;
578}
579
580Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
581  Expr *AssertExpr = D->getAssertExpr();
582
583  // The expression in a static assertion is not potentially evaluated.
584  EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
585
586  ExprResult InstantiatedAssertExpr
587    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
588  if (InstantiatedAssertExpr.isInvalid())
589    return 0;
590
591  ExprResult Message(D->getMessage());
592  D->getMessage()->Retain();
593  return SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
594                                              InstantiatedAssertExpr.get(),
595                                              Message.get());
596}
597
598Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
599  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
600                                    D->getLocation(), D->getIdentifier(),
601                                    D->getTagKeywordLoc(),
602                                    /*PrevDecl=*/0);
603  Enum->setInstantiationOfMemberEnum(D);
604  Enum->setAccess(D->getAccess());
605  if (SubstQualifier(D, Enum)) return 0;
606  Owner->addDecl(Enum);
607  Enum->startDefinition();
608
609  if (D->getDeclContext()->isFunctionOrMethod())
610    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
611
612  llvm::SmallVector<Decl*, 4> Enumerators;
613
614  EnumConstantDecl *LastEnumConst = 0;
615  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
616         ECEnd = D->enumerator_end();
617       EC != ECEnd; ++EC) {
618    // The specified value for the enumerator.
619    ExprResult Value = SemaRef.Owned((Expr *)0);
620    if (Expr *UninstValue = EC->getInitExpr()) {
621      // The enumerator's value expression is not potentially evaluated.
622      EnterExpressionEvaluationContext Unevaluated(SemaRef,
623                                                   Sema::Unevaluated);
624
625      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
626    }
627
628    // Drop the initial value and continue.
629    bool isInvalid = false;
630    if (Value.isInvalid()) {
631      Value = SemaRef.Owned((Expr *)0);
632      isInvalid = true;
633    }
634
635    EnumConstantDecl *EnumConst
636      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
637                                  EC->getLocation(), EC->getIdentifier(),
638                                  Value.get());
639
640    if (isInvalid) {
641      if (EnumConst)
642        EnumConst->setInvalidDecl();
643      Enum->setInvalidDecl();
644    }
645
646    if (EnumConst) {
647      EnumConst->setAccess(Enum->getAccess());
648      Enum->addDecl(EnumConst);
649      Enumerators.push_back(EnumConst);
650      LastEnumConst = EnumConst;
651
652      if (D->getDeclContext()->isFunctionOrMethod()) {
653        // If the enumeration is within a function or method, record the enum
654        // constant as a local.
655        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst);
656      }
657    }
658  }
659
660  // FIXME: Fixup LBraceLoc and RBraceLoc
661  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
662  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
663                        Enum,
664                        Enumerators.data(), Enumerators.size(),
665                        0, 0);
666
667  return Enum;
668}
669
670Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
671  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
672  return 0;
673}
674
675Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
676  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
677
678  // Create a local instantiation scope for this class template, which
679  // will contain the instantiations of the template parameters.
680  LocalInstantiationScope Scope(SemaRef);
681  TemplateParameterList *TempParams = D->getTemplateParameters();
682  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
683  if (!InstParams)
684    return NULL;
685
686  CXXRecordDecl *Pattern = D->getTemplatedDecl();
687
688  // Instantiate the qualifier.  We have to do this first in case
689  // we're a friend declaration, because if we are then we need to put
690  // the new declaration in the appropriate context.
691  NestedNameSpecifier *Qualifier = Pattern->getQualifier();
692  if (Qualifier) {
693    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
694                                                 Pattern->getQualifierRange(),
695                                                 TemplateArgs);
696    if (!Qualifier) return 0;
697  }
698
699  CXXRecordDecl *PrevDecl = 0;
700  ClassTemplateDecl *PrevClassTemplate = 0;
701
702  // If this isn't a friend, then it's a member template, in which
703  // case we just want to build the instantiation in the
704  // specialization.  If it is a friend, we want to build it in
705  // the appropriate context.
706  DeclContext *DC = Owner;
707  if (isFriend) {
708    if (Qualifier) {
709      CXXScopeSpec SS;
710      SS.setScopeRep(Qualifier);
711      SS.setRange(Pattern->getQualifierRange());
712      DC = SemaRef.computeDeclContext(SS);
713      if (!DC) return 0;
714    } else {
715      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
716                                           Pattern->getDeclContext(),
717                                           TemplateArgs);
718    }
719
720    // Look for a previous declaration of the template in the owning
721    // context.
722    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
723                   Sema::LookupOrdinaryName, Sema::ForRedeclaration);
724    SemaRef.LookupQualifiedName(R, DC);
725
726    if (R.isSingleResult()) {
727      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
728      if (PrevClassTemplate)
729        PrevDecl = PrevClassTemplate->getTemplatedDecl();
730    }
731
732    if (!PrevClassTemplate && Qualifier) {
733      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
734        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
735        << Pattern->getQualifierRange();
736      return 0;
737    }
738
739    bool AdoptedPreviousTemplateParams = false;
740    if (PrevClassTemplate) {
741      bool Complain = true;
742
743      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
744      // template for struct std::tr1::__detail::_Map_base, where the
745      // template parameters of the friend declaration don't match the
746      // template parameters of the original declaration. In this one
747      // case, we don't complain about the ill-formed friend
748      // declaration.
749      if (isFriend && Pattern->getIdentifier() &&
750          Pattern->getIdentifier()->isStr("_Map_base") &&
751          DC->isNamespace() &&
752          cast<NamespaceDecl>(DC)->getIdentifier() &&
753          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
754        DeclContext *DCParent = DC->getParent();
755        if (DCParent->isNamespace() &&
756            cast<NamespaceDecl>(DCParent)->getIdentifier() &&
757            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
758          DeclContext *DCParent2 = DCParent->getParent();
759          if (DCParent2->isNamespace() &&
760              cast<NamespaceDecl>(DCParent2)->getIdentifier() &&
761              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") &&
762              DCParent2->getParent()->isTranslationUnit())
763            Complain = false;
764        }
765      }
766
767      TemplateParameterList *PrevParams
768        = PrevClassTemplate->getTemplateParameters();
769
770      // Make sure the parameter lists match.
771      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
772                                                  Complain,
773                                                  Sema::TPL_TemplateMatch)) {
774        if (Complain)
775          return 0;
776
777        AdoptedPreviousTemplateParams = true;
778        InstParams = PrevParams;
779      }
780
781      // Do some additional validation, then merge default arguments
782      // from the existing declarations.
783      if (!AdoptedPreviousTemplateParams &&
784          SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
785                                             Sema::TPC_ClassTemplate))
786        return 0;
787    }
788  }
789
790  CXXRecordDecl *RecordInst
791    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
792                            Pattern->getLocation(), Pattern->getIdentifier(),
793                            Pattern->getTagKeywordLoc(), PrevDecl,
794                            /*DelayTypeCreation=*/true);
795
796  if (Qualifier)
797    RecordInst->setQualifierInfo(Qualifier, Pattern->getQualifierRange());
798
799  ClassTemplateDecl *Inst
800    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
801                                D->getIdentifier(), InstParams, RecordInst,
802                                PrevClassTemplate);
803  RecordInst->setDescribedClassTemplate(Inst);
804
805  if (isFriend) {
806    if (PrevClassTemplate)
807      Inst->setAccess(PrevClassTemplate->getAccess());
808    else
809      Inst->setAccess(D->getAccess());
810
811    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0);
812    // TODO: do we want to track the instantiation progeny of this
813    // friend target decl?
814  } else {
815    Inst->setAccess(D->getAccess());
816    Inst->setInstantiatedFromMemberTemplate(D);
817  }
818
819  // Trigger creation of the type for the instantiation.
820  SemaRef.Context.getInjectedClassNameType(RecordInst,
821                                    Inst->getInjectedClassNameSpecialization());
822
823  // Finish handling of friends.
824  if (isFriend) {
825    DC->makeDeclVisibleInContext(Inst, /*Recoverable*/ false);
826    return Inst;
827  }
828
829  Owner->addDecl(Inst);
830
831  // Instantiate all of the partial specializations of this member class
832  // template.
833  llvm::SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
834  D->getPartialSpecializations(PartialSpecs);
835  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
836    InstantiateClassTemplatePartialSpecialization(Inst, PartialSpecs[I]);
837
838  return Inst;
839}
840
841Decl *
842TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
843                                   ClassTemplatePartialSpecializationDecl *D) {
844  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
845
846  // Lookup the already-instantiated declaration in the instantiation
847  // of the class template and return that.
848  DeclContext::lookup_result Found
849    = Owner->lookup(ClassTemplate->getDeclName());
850  if (Found.first == Found.second)
851    return 0;
852
853  ClassTemplateDecl *InstClassTemplate
854    = dyn_cast<ClassTemplateDecl>(*Found.first);
855  if (!InstClassTemplate)
856    return 0;
857
858  return InstClassTemplate->findPartialSpecInstantiatedFromMember(D);
859}
860
861Decl *
862TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
863  // Create a local instantiation scope for this function template, which
864  // will contain the instantiations of the template parameters and then get
865  // merged with the local instantiation scope for the function template
866  // itself.
867  LocalInstantiationScope Scope(SemaRef);
868
869  TemplateParameterList *TempParams = D->getTemplateParameters();
870  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
871  if (!InstParams)
872    return NULL;
873
874  FunctionDecl *Instantiated = 0;
875  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
876    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
877                                                                 InstParams));
878  else
879    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
880                                                          D->getTemplatedDecl(),
881                                                                InstParams));
882
883  if (!Instantiated)
884    return 0;
885
886  Instantiated->setAccess(D->getAccess());
887
888  // Link the instantiated function template declaration to the function
889  // template from which it was instantiated.
890  FunctionTemplateDecl *InstTemplate
891    = Instantiated->getDescribedFunctionTemplate();
892  InstTemplate->setAccess(D->getAccess());
893  assert(InstTemplate &&
894         "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
895
896  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
897
898  // Link the instantiation back to the pattern *unless* this is a
899  // non-definition friend declaration.
900  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
901      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
902    InstTemplate->setInstantiatedFromMemberTemplate(D);
903
904  // Make declarations visible in the appropriate context.
905  if (!isFriend)
906    Owner->addDecl(InstTemplate);
907
908  return InstTemplate;
909}
910
911Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
912  CXXRecordDecl *PrevDecl = 0;
913  if (D->isInjectedClassName())
914    PrevDecl = cast<CXXRecordDecl>(Owner);
915  else if (D->getPreviousDeclaration()) {
916    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
917                                                   D->getPreviousDeclaration(),
918                                                   TemplateArgs);
919    if (!Prev) return 0;
920    PrevDecl = cast<CXXRecordDecl>(Prev);
921  }
922
923  CXXRecordDecl *Record
924    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
925                            D->getLocation(), D->getIdentifier(),
926                            D->getTagKeywordLoc(), PrevDecl);
927
928  // Substitute the nested name specifier, if any.
929  if (SubstQualifier(D, Record))
930    return 0;
931
932  Record->setImplicit(D->isImplicit());
933  // FIXME: Check against AS_none is an ugly hack to work around the issue that
934  // the tag decls introduced by friend class declarations don't have an access
935  // specifier. Remove once this area of the code gets sorted out.
936  if (D->getAccess() != AS_none)
937    Record->setAccess(D->getAccess());
938  if (!D->isInjectedClassName())
939    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
940
941  // If the original function was part of a friend declaration,
942  // inherit its namespace state.
943  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
944    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
945
946  // Make sure that anonymous structs and unions are recorded.
947  if (D->isAnonymousStructOrUnion()) {
948    Record->setAnonymousStructOrUnion(true);
949    if (Record->getDeclContext()->getLookupContext()->isFunctionOrMethod())
950      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
951  }
952
953  Owner->addDecl(Record);
954  return Record;
955}
956
957/// Normal class members are of more specific types and therefore
958/// don't make it here.  This function serves two purposes:
959///   1) instantiating function templates
960///   2) substituting friend declarations
961/// FIXME: preserve function definitions in case #2
962Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
963                                       TemplateParameterList *TemplateParams) {
964  // Check whether there is already a function template specialization for
965  // this declaration.
966  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
967  void *InsertPos = 0;
968  if (FunctionTemplate && !TemplateParams) {
969    std::pair<const TemplateArgument *, unsigned> Innermost
970      = TemplateArgs.getInnermost();
971
972    FunctionDecl *SpecFunc
973      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
974                                             InsertPos);
975
976    // If we already have a function template specialization, return it.
977    if (SpecFunc)
978      return SpecFunc;
979  }
980
981  bool isFriend;
982  if (FunctionTemplate)
983    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
984  else
985    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
986
987  bool MergeWithParentScope = (TemplateParams != 0) ||
988    Owner->isFunctionOrMethod() ||
989    !(isa<Decl>(Owner) &&
990      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
991  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
992
993  llvm::SmallVector<ParmVarDecl *, 4> Params;
994  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
995  TInfo = SubstFunctionType(D, Params);
996  if (!TInfo)
997    return 0;
998  QualType T = TInfo->getType();
999
1000  NestedNameSpecifier *Qualifier = D->getQualifier();
1001  if (Qualifier) {
1002    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1003                                                 D->getQualifierRange(),
1004                                                 TemplateArgs);
1005    if (!Qualifier) return 0;
1006  }
1007
1008  // If we're instantiating a local function declaration, put the result
1009  // in the owner;  otherwise we need to find the instantiated context.
1010  DeclContext *DC;
1011  if (D->getDeclContext()->isFunctionOrMethod())
1012    DC = Owner;
1013  else if (isFriend && Qualifier) {
1014    CXXScopeSpec SS;
1015    SS.setScopeRep(Qualifier);
1016    SS.setRange(D->getQualifierRange());
1017    DC = SemaRef.computeDeclContext(SS);
1018    if (!DC) return 0;
1019  } else {
1020    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1021                                         TemplateArgs);
1022  }
1023
1024  FunctionDecl *Function =
1025      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
1026                           D->getDeclName(), T, TInfo,
1027                           D->getStorageClass(), D->getStorageClassAsWritten(),
1028                           D->isInlineSpecified(), D->hasWrittenPrototype());
1029
1030  if (Qualifier)
1031    Function->setQualifierInfo(Qualifier, D->getQualifierRange());
1032
1033  DeclContext *LexicalDC = Owner;
1034  if (!isFriend && D->isOutOfLine()) {
1035    assert(D->getDeclContext()->isFileContext());
1036    LexicalDC = D->getDeclContext();
1037  }
1038
1039  Function->setLexicalDeclContext(LexicalDC);
1040
1041  // Attach the parameters
1042  for (unsigned P = 0; P < Params.size(); ++P)
1043    Params[P]->setOwningFunction(Function);
1044  Function->setParams(Params.data(), Params.size());
1045
1046  SourceLocation InstantiateAtPOI;
1047  if (TemplateParams) {
1048    // Our resulting instantiation is actually a function template, since we
1049    // are substituting only the outer template parameters. For example, given
1050    //
1051    //   template<typename T>
1052    //   struct X {
1053    //     template<typename U> friend void f(T, U);
1054    //   };
1055    //
1056    //   X<int> x;
1057    //
1058    // We are instantiating the friend function template "f" within X<int>,
1059    // which means substituting int for T, but leaving "f" as a friend function
1060    // template.
1061    // Build the function template itself.
1062    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1063                                                    Function->getLocation(),
1064                                                    Function->getDeclName(),
1065                                                    TemplateParams, Function);
1066    Function->setDescribedFunctionTemplate(FunctionTemplate);
1067
1068    FunctionTemplate->setLexicalDeclContext(LexicalDC);
1069
1070    if (isFriend && D->isThisDeclarationADefinition()) {
1071      // TODO: should we remember this connection regardless of whether
1072      // the friend declaration provided a body?
1073      FunctionTemplate->setInstantiatedFromMemberTemplate(
1074                                           D->getDescribedFunctionTemplate());
1075    }
1076  } else if (FunctionTemplate) {
1077    // Record this function template specialization.
1078    std::pair<const TemplateArgument *, unsigned> Innermost
1079      = TemplateArgs.getInnermost();
1080    Function->setFunctionTemplateSpecialization(FunctionTemplate,
1081                  new (SemaRef.Context) TemplateArgumentList(SemaRef.Context,
1082                                                             Innermost.first,
1083                                                             Innermost.second),
1084                                                InsertPos);
1085  } else if (isFriend && D->isThisDeclarationADefinition()) {
1086    // TODO: should we remember this connection regardless of whether
1087    // the friend declaration provided a body?
1088    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1089  }
1090
1091  if (InitFunctionInstantiation(Function, D))
1092    Function->setInvalidDecl();
1093
1094  bool Redeclaration = false;
1095  bool OverloadableAttrRequired = false;
1096  bool isExplicitSpecialization = false;
1097
1098  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(),
1099                        Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1100
1101  if (DependentFunctionTemplateSpecializationInfo *Info
1102        = D->getDependentSpecializationInfo()) {
1103    assert(isFriend && "non-friend has dependent specialization info?");
1104
1105    // This needs to be set now for future sanity.
1106    Function->setObjectOfFriendDecl(/*HasPrevious*/ true);
1107
1108    // Instantiate the explicit template arguments.
1109    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1110                                          Info->getRAngleLoc());
1111    for (unsigned I = 0, E = Info->getNumTemplateArgs(); I != E; ++I) {
1112      TemplateArgumentLoc Loc;
1113      if (SemaRef.Subst(Info->getTemplateArg(I), Loc, TemplateArgs))
1114        return 0;
1115
1116      ExplicitArgs.addArgument(Loc);
1117    }
1118
1119    // Map the candidate templates to their instantiations.
1120    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1121      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1122                                                Info->getTemplate(I),
1123                                                TemplateArgs);
1124      if (!Temp) return 0;
1125
1126      Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1127    }
1128
1129    if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1130                                                    &ExplicitArgs,
1131                                                    Previous))
1132      Function->setInvalidDecl();
1133
1134    isExplicitSpecialization = true;
1135
1136  } else if (TemplateParams || !FunctionTemplate) {
1137    // Look only into the namespace where the friend would be declared to
1138    // find a previous declaration. This is the innermost enclosing namespace,
1139    // as described in ActOnFriendFunctionDecl.
1140    SemaRef.LookupQualifiedName(Previous, DC);
1141
1142    // In C++, the previous declaration we find might be a tag type
1143    // (class or enum). In this case, the new declaration will hide the
1144    // tag type. Note that this does does not apply if we're declaring a
1145    // typedef (C++ [dcl.typedef]p4).
1146    if (Previous.isSingleTagDecl())
1147      Previous.clear();
1148  }
1149
1150  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous,
1151                                   isExplicitSpecialization, Redeclaration,
1152                                   /*FIXME:*/OverloadableAttrRequired);
1153
1154  NamedDecl *PrincipalDecl = (TemplateParams
1155                              ? cast<NamedDecl>(FunctionTemplate)
1156                              : Function);
1157
1158  // If the original function was part of a friend declaration,
1159  // inherit its namespace state and add it to the owner.
1160  if (isFriend) {
1161    NamedDecl *PrevDecl;
1162    if (TemplateParams)
1163      PrevDecl = FunctionTemplate->getPreviousDeclaration();
1164    else
1165      PrevDecl = Function->getPreviousDeclaration();
1166
1167    PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0);
1168    DC->makeDeclVisibleInContext(PrincipalDecl, /*Recoverable=*/ false);
1169
1170    if (!SemaRef.getLangOptions().CPlusPlus0x &&
1171        D->isThisDeclarationADefinition()) {
1172      // Check for a function body.
1173      const FunctionDecl *Definition = 0;
1174      if (Function->hasBody(Definition) &&
1175          Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1176        SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1177          << Function->getDeclName();
1178        SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1179        Function->setInvalidDecl();
1180      }
1181      // Check for redefinitions due to other instantiations of this or
1182      // a similar friend function.
1183      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(),
1184                                           REnd = Function->redecls_end();
1185                R != REnd; ++R) {
1186        if (*R == Function)
1187          continue;
1188        if ((*R)->getFriendObjectKind() != Decl::FOK_None) {
1189          if (const FunctionDecl *RPattern
1190              = (*R)->getTemplateInstantiationPattern())
1191            if (RPattern->hasBody(RPattern)) {
1192              SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1193                << Function->getDeclName();
1194              SemaRef.Diag((*R)->getLocation(), diag::note_previous_definition);
1195              Function->setInvalidDecl();
1196              break;
1197            }
1198        }
1199      }
1200    }
1201
1202  }
1203
1204  if (Function->isOverloadedOperator() && !DC->isRecord() &&
1205      PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1206    PrincipalDecl->setNonMemberOperator();
1207
1208  return Function;
1209}
1210
1211Decl *
1212TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1213                                      TemplateParameterList *TemplateParams) {
1214  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1215  void *InsertPos = 0;
1216  if (FunctionTemplate && !TemplateParams) {
1217    // We are creating a function template specialization from a function
1218    // template. Check whether there is already a function template
1219    // specialization for this particular set of template arguments.
1220    std::pair<const TemplateArgument *, unsigned> Innermost
1221      = TemplateArgs.getInnermost();
1222
1223    FunctionDecl *SpecFunc
1224      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second,
1225                                             InsertPos);
1226
1227    // If we already have a function template specialization, return it.
1228    if (SpecFunc)
1229      return SpecFunc;
1230  }
1231
1232  bool isFriend;
1233  if (FunctionTemplate)
1234    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1235  else
1236    isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1237
1238  bool MergeWithParentScope = (TemplateParams != 0) ||
1239    !(isa<Decl>(Owner) &&
1240      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1241  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1242
1243  llvm::SmallVector<ParmVarDecl *, 4> Params;
1244  TypeSourceInfo *TInfo = D->getTypeSourceInfo();
1245  TInfo = SubstFunctionType(D, Params);
1246  if (!TInfo)
1247    return 0;
1248  QualType T = TInfo->getType();
1249
1250  // \brief If the type of this function is not *directly* a function
1251  // type, then we're instantiating the a function that was declared
1252  // via a typedef, e.g.,
1253  //
1254  //   typedef int functype(int, int);
1255  //   functype func;
1256  //
1257  // In this case, we'll just go instantiate the ParmVarDecls that we
1258  // synthesized in the method declaration.
1259  if (!isa<FunctionProtoType>(T)) {
1260    assert(!Params.size() && "Instantiating type could not yield parameters");
1261    for (unsigned I = 0, N = D->getNumParams(); I != N; ++I) {
1262      ParmVarDecl *P = SemaRef.SubstParmVarDecl(D->getParamDecl(I),
1263                                                TemplateArgs);
1264      if (!P)
1265        return 0;
1266
1267      Params.push_back(P);
1268    }
1269  }
1270
1271  NestedNameSpecifier *Qualifier = D->getQualifier();
1272  if (Qualifier) {
1273    Qualifier = SemaRef.SubstNestedNameSpecifier(Qualifier,
1274                                                 D->getQualifierRange(),
1275                                                 TemplateArgs);
1276    if (!Qualifier) return 0;
1277  }
1278
1279  DeclContext *DC = Owner;
1280  if (isFriend) {
1281    if (Qualifier) {
1282      CXXScopeSpec SS;
1283      SS.setScopeRep(Qualifier);
1284      SS.setRange(D->getQualifierRange());
1285      DC = SemaRef.computeDeclContext(SS);
1286    } else {
1287      DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1288                                           D->getDeclContext(),
1289                                           TemplateArgs);
1290    }
1291    if (!DC) return 0;
1292  }
1293
1294  // Build the instantiated method declaration.
1295  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1296  CXXMethodDecl *Method = 0;
1297
1298  DeclarationNameInfo NameInfo
1299    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1300  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1301    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1302                                        NameInfo, T, TInfo,
1303                                        Constructor->isExplicit(),
1304                                        Constructor->isInlineSpecified(),
1305                                        false);
1306  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1307    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1308                                       NameInfo, T,
1309                                       Destructor->isInlineSpecified(),
1310                                       false);
1311  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1312    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1313                                       NameInfo, T, TInfo,
1314                                       Conversion->isInlineSpecified(),
1315                                       Conversion->isExplicit());
1316  } else {
1317    Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1318                                   NameInfo, T, TInfo,
1319                                   D->isStatic(),
1320                                   D->getStorageClassAsWritten(),
1321                                   D->isInlineSpecified());
1322  }
1323
1324  if (Qualifier)
1325    Method->setQualifierInfo(Qualifier, D->getQualifierRange());
1326
1327  if (TemplateParams) {
1328    // Our resulting instantiation is actually a function template, since we
1329    // are substituting only the outer template parameters. For example, given
1330    //
1331    //   template<typename T>
1332    //   struct X {
1333    //     template<typename U> void f(T, U);
1334    //   };
1335    //
1336    //   X<int> x;
1337    //
1338    // We are instantiating the member template "f" within X<int>, which means
1339    // substituting int for T, but leaving "f" as a member function template.
1340    // Build the function template itself.
1341    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1342                                                    Method->getLocation(),
1343                                                    Method->getDeclName(),
1344                                                    TemplateParams, Method);
1345    if (isFriend) {
1346      FunctionTemplate->setLexicalDeclContext(Owner);
1347      FunctionTemplate->setObjectOfFriendDecl(true);
1348    } else if (D->isOutOfLine())
1349      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1350    Method->setDescribedFunctionTemplate(FunctionTemplate);
1351  } else if (FunctionTemplate) {
1352    // Record this function template specialization.
1353    std::pair<const TemplateArgument *, unsigned> Innermost
1354      = TemplateArgs.getInnermost();
1355    Method->setFunctionTemplateSpecialization(FunctionTemplate,
1356                    new (SemaRef.Context) TemplateArgumentList(SemaRef.Context,
1357                                                              Innermost.first,
1358                                                              Innermost.second),
1359                                              InsertPos);
1360  } else if (!isFriend) {
1361    // Record that this is an instantiation of a member function.
1362    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1363  }
1364
1365  // If we are instantiating a member function defined
1366  // out-of-line, the instantiation will have the same lexical
1367  // context (which will be a namespace scope) as the template.
1368  if (isFriend) {
1369    Method->setLexicalDeclContext(Owner);
1370    Method->setObjectOfFriendDecl(true);
1371  } else if (D->isOutOfLine())
1372    Method->setLexicalDeclContext(D->getLexicalDeclContext());
1373
1374  // Attach the parameters
1375  for (unsigned P = 0; P < Params.size(); ++P)
1376    Params[P]->setOwningFunction(Method);
1377  Method->setParams(Params.data(), Params.size());
1378
1379  if (InitMethodInstantiation(Method, D))
1380    Method->setInvalidDecl();
1381
1382  LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
1383                        Sema::ForRedeclaration);
1384
1385  if (!FunctionTemplate || TemplateParams || isFriend) {
1386    SemaRef.LookupQualifiedName(Previous, Record);
1387
1388    // In C++, the previous declaration we find might be a tag type
1389    // (class or enum). In this case, the new declaration will hide the
1390    // tag type. Note that this does does not apply if we're declaring a
1391    // typedef (C++ [dcl.typedef]p4).
1392    if (Previous.isSingleTagDecl())
1393      Previous.clear();
1394  }
1395
1396  bool Redeclaration = false;
1397  bool OverloadableAttrRequired = false;
1398  SemaRef.CheckFunctionDeclaration(0, Method, Previous, false, Redeclaration,
1399                                   /*FIXME:*/OverloadableAttrRequired);
1400
1401  if (D->isPure())
1402    SemaRef.CheckPureMethod(Method, SourceRange());
1403
1404  Method->setAccess(D->getAccess());
1405
1406  if (FunctionTemplate) {
1407    // If there's a function template, let our caller handle it.
1408  } else if (Method->isInvalidDecl() && !Previous.empty()) {
1409    // Don't hide a (potentially) valid declaration with an invalid one.
1410  } else {
1411    NamedDecl *DeclToAdd = (TemplateParams
1412                            ? cast<NamedDecl>(FunctionTemplate)
1413                            : Method);
1414    if (isFriend)
1415      Record->makeDeclVisibleInContext(DeclToAdd);
1416    else
1417      Owner->addDecl(DeclToAdd);
1418  }
1419
1420  return Method;
1421}
1422
1423Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1424  return VisitCXXMethodDecl(D);
1425}
1426
1427Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1428  return VisitCXXMethodDecl(D);
1429}
1430
1431Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
1432  return VisitCXXMethodDecl(D);
1433}
1434
1435ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
1436  return SemaRef.SubstParmVarDecl(D, TemplateArgs);
1437}
1438
1439Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
1440                                                    TemplateTypeParmDecl *D) {
1441  // TODO: don't always clone when decls are refcounted.
1442  const Type* T = D->getTypeForDecl();
1443  assert(T->isTemplateTypeParmType());
1444  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
1445
1446  TemplateTypeParmDecl *Inst =
1447    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1448                                 TTPT->getDepth() - 1, TTPT->getIndex(),
1449                                 TTPT->getName(),
1450                                 D->wasDeclaredWithTypename(),
1451                                 D->isParameterPack());
1452
1453  if (D->hasDefaultArgument())
1454    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
1455
1456  // Introduce this template parameter's instantiation into the instantiation
1457  // scope.
1458  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1459
1460  return Inst;
1461}
1462
1463Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
1464                                                 NonTypeTemplateParmDecl *D) {
1465  // Substitute into the type of the non-type template parameter.
1466  QualType T;
1467  TypeSourceInfo *DI = D->getTypeSourceInfo();
1468  if (DI) {
1469    DI = SemaRef.SubstType(DI, TemplateArgs, D->getLocation(),
1470                           D->getDeclName());
1471    if (DI) T = DI->getType();
1472  } else {
1473    T = SemaRef.SubstType(D->getType(), TemplateArgs, D->getLocation(),
1474                          D->getDeclName());
1475    DI = 0;
1476  }
1477  if (T.isNull())
1478    return 0;
1479
1480  // Check that this type is acceptable for a non-type template parameter.
1481  bool Invalid = false;
1482  T = SemaRef.CheckNonTypeTemplateParameterType(T, D->getLocation());
1483  if (T.isNull()) {
1484    T = SemaRef.Context.IntTy;
1485    Invalid = true;
1486  }
1487
1488  NonTypeTemplateParmDecl *Param
1489    = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1490                                      D->getDepth() - 1, D->getPosition(),
1491                                      D->getIdentifier(), T, DI);
1492  if (Invalid)
1493    Param->setInvalidDecl();
1494
1495  Param->setDefaultArgument(D->getDefaultArgument(), false);
1496
1497  // Introduce this template parameter's instantiation into the instantiation
1498  // scope.
1499  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1500  return Param;
1501}
1502
1503Decl *
1504TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
1505                                                  TemplateTemplateParmDecl *D) {
1506  // Instantiate the template parameter list of the template template parameter.
1507  TemplateParameterList *TempParams = D->getTemplateParameters();
1508  TemplateParameterList *InstParams;
1509  {
1510    // Perform the actual substitution of template parameters within a new,
1511    // local instantiation scope.
1512    LocalInstantiationScope Scope(SemaRef);
1513    InstParams = SubstTemplateParams(TempParams);
1514    if (!InstParams)
1515      return NULL;
1516  }
1517
1518  // Build the template template parameter.
1519  TemplateTemplateParmDecl *Param
1520    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1521                                       D->getDepth() - 1, D->getPosition(),
1522                                       D->getIdentifier(), InstParams);
1523  Param->setDefaultArgument(D->getDefaultArgument(), false);
1524
1525  // Introduce this template parameter's instantiation into the instantiation
1526  // scope.
1527  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
1528
1529  return Param;
1530}
1531
1532Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1533  // Using directives are never dependent, so they require no explicit
1534
1535  UsingDirectiveDecl *Inst
1536    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
1537                                 D->getNamespaceKeyLocation(),
1538                                 D->getQualifierRange(), D->getQualifier(),
1539                                 D->getIdentLocation(),
1540                                 D->getNominatedNamespace(),
1541                                 D->getCommonAncestor());
1542  Owner->addDecl(Inst);
1543  return Inst;
1544}
1545
1546Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
1547  // The nested name specifier is non-dependent, so no transformation
1548  // is required. The same holds for the name info.
1549  DeclarationNameInfo NameInfo = D->getNameInfo();
1550
1551  // We only need to do redeclaration lookups if we're in a class
1552  // scope (in fact, it's not really even possible in non-class
1553  // scopes).
1554  bool CheckRedeclaration = Owner->isRecord();
1555
1556  LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
1557                    Sema::ForRedeclaration);
1558
1559  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
1560                                       D->getNestedNameRange(),
1561                                       D->getUsingLocation(),
1562                                       D->getTargetNestedNameDecl(),
1563                                       NameInfo,
1564                                       D->isTypeName());
1565
1566  CXXScopeSpec SS;
1567  SS.setScopeRep(D->getTargetNestedNameDecl());
1568  SS.setRange(D->getNestedNameRange());
1569
1570  if (CheckRedeclaration) {
1571    Prev.setHideTags(false);
1572    SemaRef.LookupQualifiedName(Prev, Owner);
1573
1574    // Check for invalid redeclarations.
1575    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(),
1576                                            D->isTypeName(), SS,
1577                                            D->getLocation(), Prev))
1578      NewUD->setInvalidDecl();
1579
1580  }
1581
1582  if (!NewUD->isInvalidDecl() &&
1583      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS,
1584                                      D->getLocation()))
1585    NewUD->setInvalidDecl();
1586
1587  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
1588  NewUD->setAccess(D->getAccess());
1589  Owner->addDecl(NewUD);
1590
1591  // Don't process the shadow decls for an invalid decl.
1592  if (NewUD->isInvalidDecl())
1593    return NewUD;
1594
1595  bool isFunctionScope = Owner->isFunctionOrMethod();
1596
1597  // Process the shadow decls.
1598  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
1599         I != E; ++I) {
1600    UsingShadowDecl *Shadow = *I;
1601    NamedDecl *InstTarget =
1602      cast<NamedDecl>(SemaRef.FindInstantiatedDecl(Shadow->getLocation(),
1603                                                   Shadow->getTargetDecl(),
1604                                                   TemplateArgs));
1605
1606    if (CheckRedeclaration &&
1607        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
1608      continue;
1609
1610    UsingShadowDecl *InstShadow
1611      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
1612    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
1613
1614    if (isFunctionScope)
1615      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
1616  }
1617
1618  return NewUD;
1619}
1620
1621Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
1622  // Ignore these;  we handle them in bulk when processing the UsingDecl.
1623  return 0;
1624}
1625
1626Decl * TemplateDeclInstantiator
1627    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
1628  NestedNameSpecifier *NNS =
1629    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1630                                     D->getTargetNestedNameRange(),
1631                                     TemplateArgs);
1632  if (!NNS)
1633    return 0;
1634
1635  CXXScopeSpec SS;
1636  SS.setRange(D->getTargetNestedNameRange());
1637  SS.setScopeRep(NNS);
1638
1639  // Since NameInfo refers to a typename, it cannot be a C++ special name.
1640  // Hence, no tranformation is required for it.
1641  DeclarationNameInfo NameInfo(D->getDeclName(), D->getLocation());
1642  NamedDecl *UD =
1643    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1644                                  D->getUsingLoc(), SS, NameInfo, 0,
1645                                  /*instantiation*/ true,
1646                                  /*typename*/ true, D->getTypenameLoc());
1647  if (UD)
1648    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1649
1650  return UD;
1651}
1652
1653Decl * TemplateDeclInstantiator
1654    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1655  NestedNameSpecifier *NNS =
1656    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
1657                                     D->getTargetNestedNameRange(),
1658                                     TemplateArgs);
1659  if (!NNS)
1660    return 0;
1661
1662  CXXScopeSpec SS;
1663  SS.setRange(D->getTargetNestedNameRange());
1664  SS.setScopeRep(NNS);
1665
1666  DeclarationNameInfo NameInfo
1667    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1668
1669  NamedDecl *UD =
1670    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(),
1671                                  D->getUsingLoc(), SS, NameInfo, 0,
1672                                  /*instantiation*/ true,
1673                                  /*typename*/ false, SourceLocation());
1674  if (UD)
1675    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D);
1676
1677  return UD;
1678}
1679
1680Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
1681                      const MultiLevelTemplateArgumentList &TemplateArgs) {
1682  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
1683  if (D->isInvalidDecl())
1684    return 0;
1685
1686  return Instantiator.Visit(D);
1687}
1688
1689/// \brief Instantiates a nested template parameter list in the current
1690/// instantiation context.
1691///
1692/// \param L The parameter list to instantiate
1693///
1694/// \returns NULL if there was an error
1695TemplateParameterList *
1696TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
1697  // Get errors for all the parameters before bailing out.
1698  bool Invalid = false;
1699
1700  unsigned N = L->size();
1701  typedef llvm::SmallVector<NamedDecl *, 8> ParamVector;
1702  ParamVector Params;
1703  Params.reserve(N);
1704  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
1705       PI != PE; ++PI) {
1706    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
1707    Params.push_back(D);
1708    Invalid = Invalid || !D || D->isInvalidDecl();
1709  }
1710
1711  // Clean up if we had an error.
1712  if (Invalid)
1713    return NULL;
1714
1715  TemplateParameterList *InstL
1716    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
1717                                    L->getLAngleLoc(), &Params.front(), N,
1718                                    L->getRAngleLoc());
1719  return InstL;
1720}
1721
1722/// \brief Instantiate the declaration of a class template partial
1723/// specialization.
1724///
1725/// \param ClassTemplate the (instantiated) class template that is partially
1726// specialized by the instantiation of \p PartialSpec.
1727///
1728/// \param PartialSpec the (uninstantiated) class template partial
1729/// specialization that we are instantiating.
1730///
1731/// \returns true if there was an error, false otherwise.
1732bool
1733TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
1734                                            ClassTemplateDecl *ClassTemplate,
1735                          ClassTemplatePartialSpecializationDecl *PartialSpec) {
1736  // Create a local instantiation scope for this class template partial
1737  // specialization, which will contain the instantiations of the template
1738  // parameters.
1739  LocalInstantiationScope Scope(SemaRef);
1740
1741  // Substitute into the template parameters of the class template partial
1742  // specialization.
1743  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
1744  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1745  if (!InstParams)
1746    return true;
1747
1748  // Substitute into the template arguments of the class template partial
1749  // specialization.
1750  const TemplateArgumentLoc *PartialSpecTemplateArgs
1751    = PartialSpec->getTemplateArgsAsWritten();
1752  unsigned N = PartialSpec->getNumTemplateArgsAsWritten();
1753
1754  TemplateArgumentListInfo InstTemplateArgs; // no angle locations
1755  for (unsigned I = 0; I != N; ++I) {
1756    TemplateArgumentLoc Loc;
1757    if (SemaRef.Subst(PartialSpecTemplateArgs[I], Loc, TemplateArgs))
1758      return true;
1759    InstTemplateArgs.addArgument(Loc);
1760  }
1761
1762
1763  // Check that the template argument list is well-formed for this
1764  // class template.
1765  TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(),
1766                                        InstTemplateArgs.size());
1767  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
1768                                        PartialSpec->getLocation(),
1769                                        InstTemplateArgs,
1770                                        false,
1771                                        Converted))
1772    return true;
1773
1774  // Figure out where to insert this class template partial specialization
1775  // in the member template's set of class template partial specializations.
1776  void *InsertPos = 0;
1777  ClassTemplateSpecializationDecl *PrevDecl
1778    = ClassTemplate->findPartialSpecialization(Converted.getFlatArguments(),
1779                                                Converted.flatSize(), InsertPos);
1780
1781  // Build the canonical type that describes the converted template
1782  // arguments of the class template partial specialization.
1783  QualType CanonType
1784    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
1785                                                  Converted.getFlatArguments(),
1786                                                    Converted.flatSize());
1787
1788  // Build the fully-sugared type for this class template
1789  // specialization as the user wrote in the specialization
1790  // itself. This means that we'll pretty-print the type retrieved
1791  // from the specialization's declaration the way that the user
1792  // actually wrote the specialization, rather than formatting the
1793  // name based on the "canonical" representation used to store the
1794  // template arguments in the specialization.
1795  TypeSourceInfo *WrittenTy
1796    = SemaRef.Context.getTemplateSpecializationTypeInfo(
1797                                                    TemplateName(ClassTemplate),
1798                                                    PartialSpec->getLocation(),
1799                                                    InstTemplateArgs,
1800                                                    CanonType);
1801
1802  if (PrevDecl) {
1803    // We've already seen a partial specialization with the same template
1804    // parameters and template arguments. This can happen, for example, when
1805    // substituting the outer template arguments ends up causing two
1806    // class template partial specializations of a member class template
1807    // to have identical forms, e.g.,
1808    //
1809    //   template<typename T, typename U>
1810    //   struct Outer {
1811    //     template<typename X, typename Y> struct Inner;
1812    //     template<typename Y> struct Inner<T, Y>;
1813    //     template<typename Y> struct Inner<U, Y>;
1814    //   };
1815    //
1816    //   Outer<int, int> outer; // error: the partial specializations of Inner
1817    //                          // have the same signature.
1818    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
1819      << WrittenTy;
1820    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
1821      << SemaRef.Context.getTypeDeclType(PrevDecl);
1822    return true;
1823  }
1824
1825
1826  // Create the class template partial specialization declaration.
1827  ClassTemplatePartialSpecializationDecl *InstPartialSpec
1828    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
1829                                                     PartialSpec->getTagKind(),
1830                                                     Owner,
1831                                                     PartialSpec->getLocation(),
1832                                                     InstParams,
1833                                                     ClassTemplate,
1834                                                     Converted,
1835                                                     InstTemplateArgs,
1836                                                     CanonType,
1837                                                     0,
1838                             ClassTemplate->getNextPartialSpecSequenceNumber());
1839  // Substitute the nested name specifier, if any.
1840  if (SubstQualifier(PartialSpec, InstPartialSpec))
1841    return 0;
1842
1843  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
1844  InstPartialSpec->setTypeAsWritten(WrittenTy);
1845
1846  // Add this partial specialization to the set of class template partial
1847  // specializations.
1848  ClassTemplate->AddPartialSpecialization(InstPartialSpec, InsertPos);
1849  return false;
1850}
1851
1852TypeSourceInfo*
1853TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
1854                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
1855  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
1856  assert(OldTInfo && "substituting function without type source info");
1857  assert(Params.empty() && "parameter vector is non-empty at start");
1858  TypeSourceInfo *NewTInfo
1859    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
1860                                    D->getTypeSpecStartLoc(),
1861                                    D->getDeclName());
1862  if (!NewTInfo)
1863    return 0;
1864
1865  if (NewTInfo != OldTInfo) {
1866    // Get parameters from the new type info.
1867    TypeLoc OldTL = OldTInfo->getTypeLoc();
1868    if (FunctionProtoTypeLoc *OldProtoLoc
1869                                  = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1870      TypeLoc NewTL = NewTInfo->getTypeLoc();
1871      FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL);
1872      assert(NewProtoLoc && "Missing prototype?");
1873      for (unsigned i = 0, i_end = NewProtoLoc->getNumArgs(); i != i_end; ++i) {
1874        // FIXME: Variadic templates will break this.
1875        Params.push_back(NewProtoLoc->getArg(i));
1876        SemaRef.CurrentInstantiationScope->InstantiatedLocal(
1877                                                        OldProtoLoc->getArg(i),
1878                                                        NewProtoLoc->getArg(i));
1879      }
1880    }
1881  } else {
1882    // The function type itself was not dependent and therefore no
1883    // substitution occurred. However, we still need to instantiate
1884    // the function parameters themselves.
1885    TypeLoc OldTL = OldTInfo->getTypeLoc();
1886    if (FunctionProtoTypeLoc *OldProtoLoc
1887                                    = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) {
1888      for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) {
1889        ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i));
1890        if (!Parm)
1891          return 0;
1892        Params.push_back(Parm);
1893      }
1894    }
1895  }
1896  return NewTInfo;
1897}
1898
1899/// \brief Initializes the common fields of an instantiation function
1900/// declaration (New) from the corresponding fields of its template (Tmpl).
1901///
1902/// \returns true if there was an error
1903bool
1904TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
1905                                                    FunctionDecl *Tmpl) {
1906  if (Tmpl->isDeleted())
1907    New->setDeleted();
1908
1909  // If we are performing substituting explicitly-specified template arguments
1910  // or deduced template arguments into a function template and we reach this
1911  // point, we are now past the point where SFINAE applies and have committed
1912  // to keeping the new function template specialization. We therefore
1913  // convert the active template instantiation for the function template
1914  // into a template instantiation for this specific function template
1915  // specialization, which is not a SFINAE context, so that we diagnose any
1916  // further errors in the declaration itself.
1917  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
1918  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
1919  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
1920      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
1921    if (FunctionTemplateDecl *FunTmpl
1922          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
1923      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
1924             "Deduction from the wrong function template?");
1925      (void) FunTmpl;
1926      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
1927      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
1928      --SemaRef.NonInstantiationEntries;
1929    }
1930  }
1931
1932  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
1933  assert(Proto && "Function template without prototype?");
1934
1935  if (Proto->hasExceptionSpec() || Proto->hasAnyExceptionSpec() ||
1936      Proto->getNoReturnAttr()) {
1937    // The function has an exception specification or a "noreturn"
1938    // attribute. Substitute into each of the exception types.
1939    llvm::SmallVector<QualType, 4> Exceptions;
1940    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
1941      // FIXME: Poor location information!
1942      QualType T
1943        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
1944                            New->getLocation(), New->getDeclName());
1945      if (T.isNull() ||
1946          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
1947        continue;
1948
1949      Exceptions.push_back(T);
1950    }
1951
1952    // Rebuild the function type
1953
1954    const FunctionProtoType *NewProto
1955      = New->getType()->getAs<FunctionProtoType>();
1956    assert(NewProto && "Template instantiation without function prototype?");
1957    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
1958                                                 NewProto->arg_type_begin(),
1959                                                 NewProto->getNumArgs(),
1960                                                 NewProto->isVariadic(),
1961                                                 NewProto->getTypeQuals(),
1962                                                 Proto->hasExceptionSpec(),
1963                                                 Proto->hasAnyExceptionSpec(),
1964                                                 Exceptions.size(),
1965                                                 Exceptions.data(),
1966                                                 Proto->getExtInfo()));
1967  }
1968
1969  SemaRef.InstantiateAttrs(TemplateArgs, Tmpl, New);
1970
1971  return false;
1972}
1973
1974/// \brief Initializes common fields of an instantiated method
1975/// declaration (New) from the corresponding fields of its template
1976/// (Tmpl).
1977///
1978/// \returns true if there was an error
1979bool
1980TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
1981                                                  CXXMethodDecl *Tmpl) {
1982  if (InitFunctionInstantiation(New, Tmpl))
1983    return true;
1984
1985  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
1986  New->setAccess(Tmpl->getAccess());
1987  if (Tmpl->isVirtualAsWritten())
1988    Record->setMethodAsVirtual(New);
1989
1990  // FIXME: attributes
1991  // FIXME: New needs a pointer to Tmpl
1992  return false;
1993}
1994
1995/// \brief Instantiate the definition of the given function from its
1996/// template.
1997///
1998/// \param PointOfInstantiation the point at which the instantiation was
1999/// required. Note that this is not precisely a "point of instantiation"
2000/// for the function, but it's close.
2001///
2002/// \param Function the already-instantiated declaration of a
2003/// function template specialization or member function of a class template
2004/// specialization.
2005///
2006/// \param Recursive if true, recursively instantiates any functions that
2007/// are required by this instantiation.
2008///
2009/// \param DefinitionRequired if true, then we are performing an explicit
2010/// instantiation where the body of the function is required. Complain if
2011/// there is no such body.
2012void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
2013                                         FunctionDecl *Function,
2014                                         bool Recursive,
2015                                         bool DefinitionRequired) {
2016  if (Function->isInvalidDecl() || Function->hasBody())
2017    return;
2018
2019  // Never instantiate an explicit specialization.
2020  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2021    return;
2022
2023  // Find the function body that we'll be substituting.
2024  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
2025  Stmt *Pattern = 0;
2026  if (PatternDecl)
2027    Pattern = PatternDecl->getBody(PatternDecl);
2028
2029  if (!Pattern) {
2030    if (DefinitionRequired) {
2031      if (Function->getPrimaryTemplate())
2032        Diag(PointOfInstantiation,
2033             diag::err_explicit_instantiation_undefined_func_template)
2034          << Function->getPrimaryTemplate();
2035      else
2036        Diag(PointOfInstantiation,
2037             diag::err_explicit_instantiation_undefined_member)
2038          << 1 << Function->getDeclName() << Function->getDeclContext();
2039
2040      if (PatternDecl)
2041        Diag(PatternDecl->getLocation(),
2042             diag::note_explicit_instantiation_here);
2043      Function->setInvalidDecl();
2044    } else if (Function->getTemplateSpecializationKind()
2045                 == TSK_ExplicitInstantiationDefinition) {
2046      PendingInstantiations.push_back(
2047        std::make_pair(Function, PointOfInstantiation));
2048    }
2049
2050    return;
2051  }
2052
2053  // C++0x [temp.explicit]p9:
2054  //   Except for inline functions, other explicit instantiation declarations
2055  //   have the effect of suppressing the implicit instantiation of the entity
2056  //   to which they refer.
2057  if (Function->getTemplateSpecializationKind()
2058        == TSK_ExplicitInstantiationDeclaration &&
2059      !PatternDecl->isInlined())
2060    return;
2061
2062  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
2063  if (Inst)
2064    return;
2065
2066  // If we're performing recursive template instantiation, create our own
2067  // queue of pending implicit instantiations that we will instantiate later,
2068  // while we're still within our own instantiation context.
2069  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2070  if (Recursive)
2071    PendingInstantiations.swap(SavedPendingInstantiations);
2072
2073  EnterExpressionEvaluationContext EvalContext(*this,
2074                                               Sema::PotentiallyEvaluated);
2075  ActOnStartOfFunctionDef(0, Function);
2076
2077  // Introduce a new scope where local variable instantiations will be
2078  // recorded, unless we're actually a member function within a local
2079  // class, in which case we need to merge our results with the parent
2080  // scope (of the enclosing function).
2081  bool MergeWithParentScope = false;
2082  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
2083    MergeWithParentScope = Rec->isLocalClass();
2084
2085  LocalInstantiationScope Scope(*this, MergeWithParentScope);
2086
2087  // Introduce the instantiated function parameters into the local
2088  // instantiation scope, and set the parameter names to those used
2089  // in the template.
2090  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
2091    const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
2092    ParmVarDecl *FunctionParam = Function->getParamDecl(I);
2093    FunctionParam->setDeclName(PatternParam->getDeclName());
2094    Scope.InstantiatedLocal(PatternParam, FunctionParam);
2095  }
2096
2097  // Enter the scope of this instantiation. We don't use
2098  // PushDeclContext because we don't have a scope.
2099  DeclContext *PreviousContext = CurContext;
2100  CurContext = Function;
2101
2102  MultiLevelTemplateArgumentList TemplateArgs =
2103    getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
2104
2105  // If this is a constructor, instantiate the member initializers.
2106  if (const CXXConstructorDecl *Ctor =
2107        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
2108    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
2109                               TemplateArgs);
2110  }
2111
2112  // Instantiate the function body.
2113  StmtResult Body = SubstStmt(Pattern, TemplateArgs);
2114
2115  if (Body.isInvalid())
2116    Function->setInvalidDecl();
2117
2118  ActOnFinishFunctionBody(Function, Body.get(),
2119                          /*IsInstantiation=*/true);
2120
2121  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
2122
2123  CurContext = PreviousContext;
2124
2125  DeclGroupRef DG(Function);
2126  Consumer.HandleTopLevelDecl(DG);
2127
2128  // This class may have local implicit instantiations that need to be
2129  // instantiation within this scope.
2130  PerformPendingInstantiations(/*LocalOnly=*/true);
2131  Scope.Exit();
2132
2133  if (Recursive) {
2134    // Instantiate any pending implicit instantiations found during the
2135    // instantiation of this template.
2136    PerformPendingInstantiations();
2137
2138    // Restore the set of pending implicit instantiations.
2139    PendingInstantiations.swap(SavedPendingInstantiations);
2140  }
2141}
2142
2143/// \brief Instantiate the definition of the given variable from its
2144/// template.
2145///
2146/// \param PointOfInstantiation the point at which the instantiation was
2147/// required. Note that this is not precisely a "point of instantiation"
2148/// for the function, but it's close.
2149///
2150/// \param Var the already-instantiated declaration of a static member
2151/// variable of a class template specialization.
2152///
2153/// \param Recursive if true, recursively instantiates any functions that
2154/// are required by this instantiation.
2155///
2156/// \param DefinitionRequired if true, then we are performing an explicit
2157/// instantiation where an out-of-line definition of the member variable
2158/// is required. Complain if there is no such definition.
2159void Sema::InstantiateStaticDataMemberDefinition(
2160                                          SourceLocation PointOfInstantiation,
2161                                                 VarDecl *Var,
2162                                                 bool Recursive,
2163                                                 bool DefinitionRequired) {
2164  if (Var->isInvalidDecl())
2165    return;
2166
2167  // Find the out-of-line definition of this static data member.
2168  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
2169  assert(Def && "This data member was not instantiated from a template?");
2170  assert(Def->isStaticDataMember() && "Not a static data member?");
2171  Def = Def->getOutOfLineDefinition();
2172
2173  if (!Def) {
2174    // We did not find an out-of-line definition of this static data member,
2175    // so we won't perform any instantiation. Rather, we rely on the user to
2176    // instantiate this definition (or provide a specialization for it) in
2177    // another translation unit.
2178    if (DefinitionRequired) {
2179      Def = Var->getInstantiatedFromStaticDataMember();
2180      Diag(PointOfInstantiation,
2181           diag::err_explicit_instantiation_undefined_member)
2182        << 2 << Var->getDeclName() << Var->getDeclContext();
2183      Diag(Def->getLocation(), diag::note_explicit_instantiation_here);
2184    } else if (Var->getTemplateSpecializationKind()
2185                 == TSK_ExplicitInstantiationDefinition) {
2186      PendingInstantiations.push_back(
2187        std::make_pair(Var, PointOfInstantiation));
2188    }
2189
2190    return;
2191  }
2192
2193  // Never instantiate an explicit specialization.
2194  if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
2195    return;
2196
2197  // C++0x [temp.explicit]p9:
2198  //   Except for inline functions, other explicit instantiation declarations
2199  //   have the effect of suppressing the implicit instantiation of the entity
2200  //   to which they refer.
2201  if (Var->getTemplateSpecializationKind()
2202        == TSK_ExplicitInstantiationDeclaration)
2203    return;
2204
2205  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
2206  if (Inst)
2207    return;
2208
2209  // If we're performing recursive template instantiation, create our own
2210  // queue of pending implicit instantiations that we will instantiate later,
2211  // while we're still within our own instantiation context.
2212  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
2213  if (Recursive)
2214    PendingInstantiations.swap(SavedPendingInstantiations);
2215
2216  // Enter the scope of this instantiation. We don't use
2217  // PushDeclContext because we don't have a scope.
2218  DeclContext *PreviousContext = CurContext;
2219  CurContext = Var->getDeclContext();
2220
2221  VarDecl *OldVar = Var;
2222  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
2223                                          getTemplateInstantiationArgs(Var)));
2224  CurContext = PreviousContext;
2225
2226  if (Var) {
2227    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo();
2228    assert(MSInfo && "Missing member specialization information?");
2229    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(),
2230                                       MSInfo->getPointOfInstantiation());
2231    DeclGroupRef DG(Var);
2232    Consumer.HandleTopLevelDecl(DG);
2233  }
2234
2235  if (Recursive) {
2236    // Instantiate any pending implicit instantiations found during the
2237    // instantiation of this template.
2238    PerformPendingInstantiations();
2239
2240    // Restore the set of pending implicit instantiations.
2241    PendingInstantiations.swap(SavedPendingInstantiations);
2242  }
2243}
2244
2245void
2246Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
2247                                 const CXXConstructorDecl *Tmpl,
2248                           const MultiLevelTemplateArgumentList &TemplateArgs) {
2249
2250  llvm::SmallVector<MemInitTy*, 4> NewInits;
2251  bool AnyErrors = false;
2252
2253  // Instantiate all the initializers.
2254  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
2255                                            InitsEnd = Tmpl->init_end();
2256       Inits != InitsEnd; ++Inits) {
2257    CXXBaseOrMemberInitializer *Init = *Inits;
2258
2259    SourceLocation LParenLoc, RParenLoc;
2260    ASTOwningVector<Expr*> NewArgs(*this);
2261    llvm::SmallVector<SourceLocation, 4> CommaLocs;
2262
2263    // Instantiate the initializer.
2264    if (InstantiateInitializer(*this, Init->getInit(), TemplateArgs,
2265                               LParenLoc, CommaLocs, NewArgs, RParenLoc)) {
2266      AnyErrors = true;
2267      continue;
2268    }
2269
2270    MemInitResult NewInit;
2271    if (Init->isBaseInitializer()) {
2272      TypeSourceInfo *BaseTInfo = SubstType(Init->getBaseClassInfo(),
2273                                            TemplateArgs,
2274                                            Init->getSourceLocation(),
2275                                            New->getDeclName());
2276      if (!BaseTInfo) {
2277        AnyErrors = true;
2278        New->setInvalidDecl();
2279        continue;
2280      }
2281
2282      NewInit = BuildBaseInitializer(BaseTInfo->getType(), BaseTInfo,
2283                                     (Expr **)NewArgs.data(),
2284                                     NewArgs.size(),
2285                                     Init->getLParenLoc(),
2286                                     Init->getRParenLoc(),
2287                                     New->getParent());
2288    } else if (Init->isMemberInitializer()) {
2289      FieldDecl *Member;
2290
2291      // Is this an anonymous union?
2292      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
2293        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2294                                                      UnionInit, TemplateArgs));
2295      else
2296        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMemberLocation(),
2297                                                      Init->getMember(),
2298                                                      TemplateArgs));
2299
2300      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
2301                                       NewArgs.size(),
2302                                       Init->getSourceLocation(),
2303                                       Init->getLParenLoc(),
2304                                       Init->getRParenLoc());
2305    }
2306
2307    if (NewInit.isInvalid()) {
2308      AnyErrors = true;
2309      New->setInvalidDecl();
2310    } else {
2311      // FIXME: It would be nice if ASTOwningVector had a release function.
2312      NewArgs.take();
2313
2314      NewInits.push_back((MemInitTy *)NewInit.get());
2315    }
2316  }
2317
2318  // Assign all the initializers to the new constructor.
2319  ActOnMemInitializers(New,
2320                       /*FIXME: ColonLoc */
2321                       SourceLocation(),
2322                       NewInits.data(), NewInits.size(),
2323                       AnyErrors);
2324}
2325
2326// TODO: this could be templated if the various decl types used the
2327// same method name.
2328static bool isInstantiationOf(ClassTemplateDecl *Pattern,
2329                              ClassTemplateDecl *Instance) {
2330  Pattern = Pattern->getCanonicalDecl();
2331
2332  do {
2333    Instance = Instance->getCanonicalDecl();
2334    if (Pattern == Instance) return true;
2335    Instance = Instance->getInstantiatedFromMemberTemplate();
2336  } while (Instance);
2337
2338  return false;
2339}
2340
2341static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
2342                              FunctionTemplateDecl *Instance) {
2343  Pattern = Pattern->getCanonicalDecl();
2344
2345  do {
2346    Instance = Instance->getCanonicalDecl();
2347    if (Pattern == Instance) return true;
2348    Instance = Instance->getInstantiatedFromMemberTemplate();
2349  } while (Instance);
2350
2351  return false;
2352}
2353
2354static bool
2355isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
2356                  ClassTemplatePartialSpecializationDecl *Instance) {
2357  Pattern
2358    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
2359  do {
2360    Instance = cast<ClassTemplatePartialSpecializationDecl>(
2361                                                Instance->getCanonicalDecl());
2362    if (Pattern == Instance)
2363      return true;
2364    Instance = Instance->getInstantiatedFromMember();
2365  } while (Instance);
2366
2367  return false;
2368}
2369
2370static bool isInstantiationOf(CXXRecordDecl *Pattern,
2371                              CXXRecordDecl *Instance) {
2372  Pattern = Pattern->getCanonicalDecl();
2373
2374  do {
2375    Instance = Instance->getCanonicalDecl();
2376    if (Pattern == Instance) return true;
2377    Instance = Instance->getInstantiatedFromMemberClass();
2378  } while (Instance);
2379
2380  return false;
2381}
2382
2383static bool isInstantiationOf(FunctionDecl *Pattern,
2384                              FunctionDecl *Instance) {
2385  Pattern = Pattern->getCanonicalDecl();
2386
2387  do {
2388    Instance = Instance->getCanonicalDecl();
2389    if (Pattern == Instance) return true;
2390    Instance = Instance->getInstantiatedFromMemberFunction();
2391  } while (Instance);
2392
2393  return false;
2394}
2395
2396static bool isInstantiationOf(EnumDecl *Pattern,
2397                              EnumDecl *Instance) {
2398  Pattern = Pattern->getCanonicalDecl();
2399
2400  do {
2401    Instance = Instance->getCanonicalDecl();
2402    if (Pattern == Instance) return true;
2403    Instance = Instance->getInstantiatedFromMemberEnum();
2404  } while (Instance);
2405
2406  return false;
2407}
2408
2409static bool isInstantiationOf(UsingShadowDecl *Pattern,
2410                              UsingShadowDecl *Instance,
2411                              ASTContext &C) {
2412  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern;
2413}
2414
2415static bool isInstantiationOf(UsingDecl *Pattern,
2416                              UsingDecl *Instance,
2417                              ASTContext &C) {
2418  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2419}
2420
2421static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern,
2422                              UsingDecl *Instance,
2423                              ASTContext &C) {
2424  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2425}
2426
2427static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern,
2428                              UsingDecl *Instance,
2429                              ASTContext &C) {
2430  return C.getInstantiatedFromUsingDecl(Instance) == Pattern;
2431}
2432
2433static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
2434                                              VarDecl *Instance) {
2435  assert(Instance->isStaticDataMember());
2436
2437  Pattern = Pattern->getCanonicalDecl();
2438
2439  do {
2440    Instance = Instance->getCanonicalDecl();
2441    if (Pattern == Instance) return true;
2442    Instance = Instance->getInstantiatedFromStaticDataMember();
2443  } while (Instance);
2444
2445  return false;
2446}
2447
2448// Other is the prospective instantiation
2449// D is the prospective pattern
2450static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
2451  if (D->getKind() != Other->getKind()) {
2452    if (UnresolvedUsingTypenameDecl *UUD
2453          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
2454      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2455        return isInstantiationOf(UUD, UD, Ctx);
2456      }
2457    }
2458
2459    if (UnresolvedUsingValueDecl *UUD
2460          = dyn_cast<UnresolvedUsingValueDecl>(D)) {
2461      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
2462        return isInstantiationOf(UUD, UD, Ctx);
2463      }
2464    }
2465
2466    return false;
2467  }
2468
2469  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
2470    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
2471
2472  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
2473    return isInstantiationOf(cast<FunctionDecl>(D), Function);
2474
2475  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
2476    return isInstantiationOf(cast<EnumDecl>(D), Enum);
2477
2478  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
2479    if (Var->isStaticDataMember())
2480      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
2481
2482  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
2483    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
2484
2485  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other))
2486    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
2487
2488  if (ClassTemplatePartialSpecializationDecl *PartialSpec
2489        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
2490    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
2491                             PartialSpec);
2492
2493  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
2494    if (!Field->getDeclName()) {
2495      // This is an unnamed field.
2496      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
2497        cast<FieldDecl>(D);
2498    }
2499  }
2500
2501  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other))
2502    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
2503
2504  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other))
2505    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
2506
2507  return D->getDeclName() && isa<NamedDecl>(Other) &&
2508    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
2509}
2510
2511template<typename ForwardIterator>
2512static NamedDecl *findInstantiationOf(ASTContext &Ctx,
2513                                      NamedDecl *D,
2514                                      ForwardIterator first,
2515                                      ForwardIterator last) {
2516  for (; first != last; ++first)
2517    if (isInstantiationOf(Ctx, D, *first))
2518      return cast<NamedDecl>(*first);
2519
2520  return 0;
2521}
2522
2523/// \brief Finds the instantiation of the given declaration context
2524/// within the current instantiation.
2525///
2526/// \returns NULL if there was an error
2527DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
2528                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2529  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
2530    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
2531    return cast_or_null<DeclContext>(ID);
2532  } else return DC;
2533}
2534
2535/// \brief Find the instantiation of the given declaration within the
2536/// current instantiation.
2537///
2538/// This routine is intended to be used when \p D is a declaration
2539/// referenced from within a template, that needs to mapped into the
2540/// corresponding declaration within an instantiation. For example,
2541/// given:
2542///
2543/// \code
2544/// template<typename T>
2545/// struct X {
2546///   enum Kind {
2547///     KnownValue = sizeof(T)
2548///   };
2549///
2550///   bool getKind() const { return KnownValue; }
2551/// };
2552///
2553/// template struct X<int>;
2554/// \endcode
2555///
2556/// In the instantiation of X<int>::getKind(), we need to map the
2557/// EnumConstantDecl for KnownValue (which refers to
2558/// X<T>::<Kind>::KnownValue) to its instantiation
2559/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
2560/// this mapping from within the instantiation of X<int>.
2561NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
2562                          const MultiLevelTemplateArgumentList &TemplateArgs) {
2563  DeclContext *ParentDC = D->getDeclContext();
2564  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
2565      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
2566      (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext())) {
2567    // D is a local of some kind. Look into the map of local
2568    // declarations to their instantiations.
2569    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
2570  }
2571
2572  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
2573    if (!Record->isDependentContext())
2574      return D;
2575
2576    // If the RecordDecl is actually the injected-class-name or a
2577    // "templated" declaration for a class template, class template
2578    // partial specialization, or a member class of a class template,
2579    // substitute into the injected-class-name of the class template
2580    // or partial specialization to find the new DeclContext.
2581    QualType T;
2582    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
2583
2584    if (ClassTemplate) {
2585      T = ClassTemplate->getInjectedClassNameSpecialization();
2586    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2587                 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
2588      ClassTemplate = PartialSpec->getSpecializedTemplate();
2589
2590      // If we call SubstType with an InjectedClassNameType here we
2591      // can end up in an infinite loop.
2592      T = Context.getTypeDeclType(Record);
2593      assert(isa<InjectedClassNameType>(T) &&
2594             "type of partial specialization is not an InjectedClassNameType");
2595      T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
2596    }
2597
2598    if (!T.isNull()) {
2599      // Substitute into the injected-class-name to get the type
2600      // corresponding to the instantiation we want, which may also be
2601      // the current instantiation (if we're in a template
2602      // definition). This substitution should never fail, since we
2603      // know we can instantiate the injected-class-name or we
2604      // wouldn't have gotten to the injected-class-name!
2605
2606      // FIXME: Can we use the CurrentInstantiationScope to avoid this
2607      // extra instantiation in the common case?
2608      T = SubstType(T, TemplateArgs, SourceLocation(), DeclarationName());
2609      assert(!T.isNull() && "Instantiation of injected-class-name cannot fail.");
2610
2611      if (!T->isDependentType()) {
2612        assert(T->isRecordType() && "Instantiation must produce a record type");
2613        return T->getAs<RecordType>()->getDecl();
2614      }
2615
2616      // We are performing "partial" template instantiation to create
2617      // the member declarations for the members of a class template
2618      // specialization. Therefore, D is actually referring to something
2619      // in the current instantiation. Look through the current
2620      // context, which contains actual instantiations, to find the
2621      // instantiation of the "current instantiation" that D refers
2622      // to.
2623      bool SawNonDependentContext = false;
2624      for (DeclContext *DC = CurContext; !DC->isFileContext();
2625           DC = DC->getParent()) {
2626        if (ClassTemplateSpecializationDecl *Spec
2627                          = dyn_cast<ClassTemplateSpecializationDecl>(DC))
2628          if (isInstantiationOf(ClassTemplate,
2629                                Spec->getSpecializedTemplate()))
2630            return Spec;
2631
2632        if (!DC->isDependentContext())
2633          SawNonDependentContext = true;
2634      }
2635
2636      // We're performing "instantiation" of a member of the current
2637      // instantiation while we are type-checking the
2638      // definition. Compute the declaration context and return that.
2639      assert(!SawNonDependentContext &&
2640             "No dependent context while instantiating record");
2641      DeclContext *DC = computeDeclContext(T);
2642      assert(DC &&
2643             "Unable to find declaration for the current instantiation");
2644      return cast<CXXRecordDecl>(DC);
2645    }
2646
2647    // Fall through to deal with other dependent record types (e.g.,
2648    // anonymous unions in class templates).
2649  }
2650
2651  if (!ParentDC->isDependentContext())
2652    return D;
2653
2654  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
2655  if (!ParentDC)
2656    return 0;
2657
2658  if (ParentDC != D->getDeclContext()) {
2659    // We performed some kind of instantiation in the parent context,
2660    // so now we need to look into the instantiated parent context to
2661    // find the instantiation of the declaration D.
2662
2663    // If our context used to be dependent, we may need to instantiate
2664    // it before performing lookup into that context.
2665    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
2666      if (!Spec->isDependentContext()) {
2667        QualType T = Context.getTypeDeclType(Spec);
2668        const RecordType *Tag = T->getAs<RecordType>();
2669        assert(Tag && "type of non-dependent record is not a RecordType");
2670        if (!Tag->isBeingDefined() &&
2671            RequireCompleteType(Loc, T, diag::err_incomplete_type))
2672          return 0;
2673      }
2674    }
2675
2676    NamedDecl *Result = 0;
2677    if (D->getDeclName()) {
2678      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
2679      Result = findInstantiationOf(Context, D, Found.first, Found.second);
2680    } else {
2681      // Since we don't have a name for the entity we're looking for,
2682      // our only option is to walk through all of the declarations to
2683      // find that name. This will occur in a few cases:
2684      //
2685      //   - anonymous struct/union within a template
2686      //   - unnamed class/struct/union/enum within a template
2687      //
2688      // FIXME: Find a better way to find these instantiations!
2689      Result = findInstantiationOf(Context, D,
2690                                   ParentDC->decls_begin(),
2691                                   ParentDC->decls_end());
2692    }
2693
2694    // UsingShadowDecls can instantiate to nothing because of using hiding.
2695    assert((Result || isa<UsingShadowDecl>(D) || D->isInvalidDecl() ||
2696            cast<Decl>(ParentDC)->isInvalidDecl())
2697           && "Unable to find instantiation of declaration!");
2698
2699    D = Result;
2700  }
2701
2702  return D;
2703}
2704
2705/// \brief Performs template instantiation for all implicit template
2706/// instantiations we have seen until this point.
2707void Sema::PerformPendingInstantiations(bool LocalOnly) {
2708  while (!PendingLocalImplicitInstantiations.empty() ||
2709         (!LocalOnly && !PendingInstantiations.empty())) {
2710    PendingImplicitInstantiation Inst;
2711
2712    if (PendingLocalImplicitInstantiations.empty()) {
2713      Inst = PendingInstantiations.front();
2714      PendingInstantiations.pop_front();
2715    } else {
2716      Inst = PendingLocalImplicitInstantiations.front();
2717      PendingLocalImplicitInstantiations.pop_front();
2718    }
2719
2720    // Instantiate function definitions
2721    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
2722      PrettyDeclStackTraceEntry CrashInfo(*this, Function, SourceLocation(),
2723                                          "instantiating function definition");
2724      bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
2725                                TSK_ExplicitInstantiationDefinition;
2726      InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true,
2727                                    DefinitionRequired);
2728      continue;
2729    }
2730
2731    // Instantiate static data member definitions.
2732    VarDecl *Var = cast<VarDecl>(Inst.first);
2733    assert(Var->isStaticDataMember() && "Not a static data member?");
2734
2735    // Don't try to instantiate declarations if the most recent redeclaration
2736    // is invalid.
2737    if (Var->getMostRecentDeclaration()->isInvalidDecl())
2738      continue;
2739
2740    // Check if the most recent declaration has changed the specialization kind
2741    // and removed the need for implicit instantiation.
2742    switch (Var->getMostRecentDeclaration()->getTemplateSpecializationKind()) {
2743    case TSK_Undeclared:
2744      assert(false && "Cannot instantitiate an undeclared specialization.");
2745    case TSK_ExplicitInstantiationDeclaration:
2746    case TSK_ExplicitSpecialization:
2747      continue;  // No longer need to instantiate this type.
2748    case TSK_ExplicitInstantiationDefinition:
2749      // We only need an instantiation if the pending instantiation *is* the
2750      // explicit instantiation.
2751      if (Var != Var->getMostRecentDeclaration()) continue;
2752    case TSK_ImplicitInstantiation:
2753      break;
2754    }
2755
2756    PrettyDeclStackTraceEntry CrashInfo(*this, Var, Var->getLocation(),
2757                                        "instantiating static data member "
2758                                        "definition");
2759
2760    bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
2761                              TSK_ExplicitInstantiationDefinition;
2762    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true,
2763                                          DefinitionRequired);
2764  }
2765}
2766
2767void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
2768                       const MultiLevelTemplateArgumentList &TemplateArgs) {
2769  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(),
2770         E = Pattern->ddiag_end(); I != E; ++I) {
2771    DependentDiagnostic *DD = *I;
2772
2773    switch (DD->getKind()) {
2774    case DependentDiagnostic::Access:
2775      HandleDependentAccessCheck(*DD, TemplateArgs);
2776      break;
2777    }
2778  }
2779}
2780
2781