SemaTemplateInstantiateDecl.cpp revision 17e32f30e2d1eaf6639d3d4e2196a8d7c709fbac 
1//===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//===----------------------------------------------------------------------===/
8//
9//  This file implements C++ template instantiation for declarations.
10//
11//===----------------------------------------------------------------------===/
12#include "Sema.h"
13#include "clang/AST/ASTConsumer.h"
14#include "clang/AST/ASTContext.h"
15#include "clang/AST/DeclTemplate.h"
16#include "clang/AST/DeclVisitor.h"
17#include "clang/AST/Expr.h"
18#include "llvm/Support/Compiler.h"
19
20using namespace clang;
21
22namespace {
23  class VISIBILITY_HIDDEN TemplateDeclInstantiator
24    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
25    Sema &SemaRef;
26    DeclContext *Owner;
27    const TemplateArgumentList &TemplateArgs;
28
29  public:
30    typedef Sema::OwningExprResult OwningExprResult;
31
32    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
33                             const TemplateArgumentList &TemplateArgs)
34      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
35
36    // FIXME: Once we get closer to completion, replace these manually-written
37    // declarations with automatically-generated ones from
38    // clang/AST/DeclNodes.def.
39    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
40    Decl *VisitNamespaceDecl(NamespaceDecl *D);
41    Decl *VisitTypedefDecl(TypedefDecl *D);
42    Decl *VisitVarDecl(VarDecl *D);
43    Decl *VisitFieldDecl(FieldDecl *D);
44    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
45    Decl *VisitEnumDecl(EnumDecl *D);
46    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
47    Decl *VisitFriendClassDecl(FriendClassDecl *D);
48    Decl *VisitFunctionDecl(FunctionDecl *D);
49    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
50    Decl *VisitCXXMethodDecl(CXXMethodDecl *D);
51    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
52    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
53    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
54    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
55    Decl *VisitOriginalParmVarDecl(OriginalParmVarDecl *D);
56    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
57    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
58
59    // Base case. FIXME: Remove once we can instantiate everything.
60    Decl *VisitDecl(Decl *) {
61      assert(false && "Template instantiation of unknown declaration kind!");
62      return 0;
63    }
64
65    const LangOptions &getLangOptions() {
66      return SemaRef.getLangOptions();
67    }
68
69    // Helper functions for instantiating methods.
70    QualType InstantiateFunctionType(FunctionDecl *D,
71                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
72    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
73    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
74
75    TemplateParameterList *
76      InstantiateTemplateParams(TemplateParameterList *List);
77  };
78}
79
80Decl *
81TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
82  assert(false && "Translation units cannot be instantiated");
83  return D;
84}
85
86Decl *
87TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
88  assert(false && "Namespaces cannot be instantiated");
89  return D;
90}
91
92Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
93  bool Invalid = false;
94  QualType T = D->getUnderlyingType();
95  if (T->isDependentType()) {
96    T = SemaRef.InstantiateType(T, TemplateArgs,
97                                D->getLocation(), D->getDeclName());
98    if (T.isNull()) {
99      Invalid = true;
100      T = SemaRef.Context.IntTy;
101    }
102  }
103
104  // Create the new typedef
105  TypedefDecl *Typedef
106    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
107                          D->getIdentifier(), T);
108  if (Invalid)
109    Typedef->setInvalidDecl();
110
111  Owner->addDecl(Typedef);
112
113  return Typedef;
114}
115
116Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
117  // Instantiate the type of the declaration
118  QualType T = SemaRef.InstantiateType(D->getType(), TemplateArgs,
119                                       D->getTypeSpecStartLoc(),
120                                       D->getDeclName());
121  if (T.isNull())
122    return 0;
123
124  // Build the instantiated declaration
125  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
126                                 D->getLocation(), D->getIdentifier(),
127                                 T, D->getDeclaratorInfo(),
128                                 D->getStorageClass());
129  Var->setThreadSpecified(D->isThreadSpecified());
130  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
131  Var->setDeclaredInCondition(D->isDeclaredInCondition());
132
133  // If we are instantiating a static data member defined
134  // out-of-line, the instantiation will have the same lexical
135  // context (which will be a namespace scope) as the template.
136  if (D->isOutOfLine())
137    Var->setLexicalDeclContext(D->getLexicalDeclContext());
138
139  // FIXME: In theory, we could have a previous declaration for variables that
140  // are not static data members.
141  bool Redeclaration = false;
142  SemaRef.CheckVariableDeclaration(Var, 0, Redeclaration);
143
144  if (D->isOutOfLine()) {
145    D->getLexicalDeclContext()->addDecl(Var);
146    Owner->makeDeclVisibleInContext(Var);
147  } else {
148    Owner->addDecl(Var);
149  }
150
151  if (D->getInit()) {
152    OwningExprResult Init
153      = SemaRef.InstantiateExpr(D->getInit(), TemplateArgs);
154    if (Init.isInvalid())
155      Var->setInvalidDecl();
156    else
157      SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var), move(Init),
158                                   D->hasCXXDirectInitializer());
159  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
160    SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
161
162  // Link instantiations of static data members back to the template from
163  // which they were instantiated.
164  if (Var->isStaticDataMember())
165    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D);
166
167  return Var;
168}
169
170Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
171  bool Invalid = false;
172  QualType T = D->getType();
173  if (T->isDependentType())  {
174    T = SemaRef.InstantiateType(T, TemplateArgs,
175                                D->getLocation(), D->getDeclName());
176    if (!T.isNull() && T->isFunctionType()) {
177      // C++ [temp.arg.type]p3:
178      //   If a declaration acquires a function type through a type
179      //   dependent on a template-parameter and this causes a
180      //   declaration that does not use the syntactic form of a
181      //   function declarator to have function type, the program is
182      //   ill-formed.
183      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
184        << T;
185      T = QualType();
186      Invalid = true;
187    }
188  }
189
190  Expr *BitWidth = D->getBitWidth();
191  if (Invalid)
192    BitWidth = 0;
193  else if (BitWidth) {
194    // The bit-width expression is not potentially evaluated.
195    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
196
197    OwningExprResult InstantiatedBitWidth
198      = SemaRef.InstantiateExpr(BitWidth, TemplateArgs);
199    if (InstantiatedBitWidth.isInvalid()) {
200      Invalid = true;
201      BitWidth = 0;
202    } else
203      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
204  }
205
206  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(), T,
207                                            D->getDeclaratorInfo(),
208                                            cast<RecordDecl>(Owner),
209                                            D->getLocation(),
210                                            D->isMutable(),
211                                            BitWidth,
212                                            D->getTypeSpecStartLoc(),
213                                            D->getAccess(),
214                                            0);
215  if (Field) {
216    if (Invalid)
217      Field->setInvalidDecl();
218
219    Owner->addDecl(Field);
220  }
221
222  return Field;
223}
224
225Decl *TemplateDeclInstantiator::VisitFriendClassDecl(FriendClassDecl *D) {
226  QualType T = D->getFriendType();
227  if (T->isDependentType())  {
228    T = SemaRef.InstantiateType(T, TemplateArgs, D->getLocation(),
229                                DeclarationName());
230    assert(T.isNull() || getLangOptions().CPlusPlus0x || T->isRecordType());
231  }
232
233  // FIXME: the target context might be dependent.
234  DeclContext *DC = D->getDeclContext();
235  assert(DC->isFileContext());
236
237  FriendClassDecl *NewD =
238    FriendClassDecl::Create(SemaRef.Context, DC, D->getLocation(), T,
239                            D->getFriendLoc());
240  Owner->addDecl(NewD);
241  return NewD;
242}
243
244Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
245  Expr *AssertExpr = D->getAssertExpr();
246
247  // The expression in a static assertion is not potentially evaluated.
248  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
249
250  OwningExprResult InstantiatedAssertExpr
251    = SemaRef.InstantiateExpr(AssertExpr, TemplateArgs);
252  if (InstantiatedAssertExpr.isInvalid())
253    return 0;
254
255  OwningExprResult Message(SemaRef, D->getMessage());
256  D->getMessage()->Retain();
257  Decl *StaticAssert
258    = SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
259                                           move(InstantiatedAssertExpr),
260                                           move(Message)).getAs<Decl>();
261  return StaticAssert;
262}
263
264Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
265  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
266                                    D->getLocation(), D->getIdentifier(),
267                                    D->getTagKeywordLoc(),
268                                    /*PrevDecl=*/0);
269  Enum->setInstantiationOfMemberEnum(D);
270  Enum->setAccess(D->getAccess());
271  Owner->addDecl(Enum);
272  Enum->startDefinition();
273
274  llvm::SmallVector<Sema::DeclPtrTy, 4> Enumerators;
275
276  EnumConstantDecl *LastEnumConst = 0;
277  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
278         ECEnd = D->enumerator_end();
279       EC != ECEnd; ++EC) {
280    // The specified value for the enumerator.
281    OwningExprResult Value = SemaRef.Owned((Expr *)0);
282    if (Expr *UninstValue = EC->getInitExpr()) {
283      // The enumerator's value expression is not potentially evaluated.
284      EnterExpressionEvaluationContext Unevaluated(SemaRef,
285                                                   Action::Unevaluated);
286
287      Value = SemaRef.InstantiateExpr(UninstValue, TemplateArgs);
288    }
289
290    // Drop the initial value and continue.
291    bool isInvalid = false;
292    if (Value.isInvalid()) {
293      Value = SemaRef.Owned((Expr *)0);
294      isInvalid = true;
295    }
296
297    EnumConstantDecl *EnumConst
298      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
299                                  EC->getLocation(), EC->getIdentifier(),
300                                  move(Value));
301
302    if (isInvalid) {
303      if (EnumConst)
304        EnumConst->setInvalidDecl();
305      Enum->setInvalidDecl();
306    }
307
308    if (EnumConst) {
309      Enum->addDecl(EnumConst);
310      Enumerators.push_back(Sema::DeclPtrTy::make(EnumConst));
311      LastEnumConst = EnumConst;
312    }
313  }
314
315  // FIXME: Fixup LBraceLoc and RBraceLoc
316  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
317  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
318                        Sema::DeclPtrTy::make(Enum),
319                        &Enumerators[0], Enumerators.size(),
320                        0, 0);
321
322  return Enum;
323}
324
325Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
326  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
327  return 0;
328}
329
330Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
331  TemplateParameterList *TempParams = D->getTemplateParameters();
332  TemplateParameterList *InstParams = InstantiateTemplateParams(TempParams);
333  if (!InstParams) return NULL;
334
335  CXXRecordDecl *Pattern = D->getTemplatedDecl();
336  CXXRecordDecl *RecordInst
337    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), Owner,
338                            Pattern->getLocation(), Pattern->getIdentifier(),
339                            Pattern->getTagKeywordLoc(), /*PrevDecl=*/ NULL);
340
341  ClassTemplateDecl *Inst
342    = ClassTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
343                                D->getIdentifier(), InstParams, RecordInst, 0);
344  RecordInst->setDescribedClassTemplate(Inst);
345  Inst->setAccess(D->getAccess());
346  Inst->setInstantiatedFromMemberTemplate(D);
347
348  Owner->addDecl(Inst);
349  return Inst;
350}
351
352Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
353  CXXRecordDecl *PrevDecl = 0;
354  if (D->isInjectedClassName())
355    PrevDecl = cast<CXXRecordDecl>(Owner);
356
357  CXXRecordDecl *Record
358    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
359                            D->getLocation(), D->getIdentifier(),
360                            D->getTagKeywordLoc(), PrevDecl);
361  Record->setImplicit(D->isImplicit());
362  Record->setAccess(D->getAccess());
363  if (!D->isInjectedClassName())
364    Record->setInstantiationOfMemberClass(D);
365
366  Owner->addDecl(Record);
367  return Record;
368}
369
370Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D) {
371  // Check whether there is already a function template specialization for
372  // this declaration.
373  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
374  void *InsertPos = 0;
375  if (FunctionTemplate) {
376    llvm::FoldingSetNodeID ID;
377    FunctionTemplateSpecializationInfo::Profile(ID,
378                                          TemplateArgs.getFlatArgumentList(),
379                                                TemplateArgs.flat_size(),
380                                                SemaRef.Context);
381
382    FunctionTemplateSpecializationInfo *Info
383      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
384                                                                   InsertPos);
385
386    // If we already have a function template specialization, return it.
387    if (Info)
388      return Info->Function;
389  }
390
391  Sema::LocalInstantiationScope Scope(SemaRef);
392
393  llvm::SmallVector<ParmVarDecl *, 4> Params;
394  QualType T = InstantiateFunctionType(D, Params);
395  if (T.isNull())
396    return 0;
397
398  // Build the instantiated method declaration.
399  FunctionDecl *Function;
400  if (FriendFunctionDecl* FFD = dyn_cast<FriendFunctionDecl>(D)) {
401    // The new decl's semantic context.  FIXME:  this might need
402    // to be instantiated.
403    DeclContext *DC = D->getDeclContext();
404
405    // This assert is bogus and exists only to catch cases we don't
406    // handle yet.
407    assert(!DC->isDependentContext());
408
409    Function =
410      FriendFunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
411                                 D->getDeclName(), T, D->getDeclaratorInfo(),
412                                 D->isInline(), FFD->getFriendLoc());
413    Function->setLexicalDeclContext(Owner);
414  } else {
415    Function =
416      FunctionDecl::Create(SemaRef.Context, Owner, D->getLocation(),
417                           D->getDeclName(), T, D->getDeclaratorInfo(),
418                           D->getStorageClass(),
419                           D->isInline(), D->hasWrittenPrototype());
420  }
421
422  // Attach the parameters
423  for (unsigned P = 0; P < Params.size(); ++P)
424    Params[P]->setOwningFunction(Function);
425  Function->setParams(SemaRef.Context, Params.data(), Params.size());
426
427  if (InitFunctionInstantiation(Function, D))
428    Function->setInvalidDecl();
429
430  bool Redeclaration = false;
431  bool OverloadableAttrRequired = false;
432  NamedDecl *PrevDecl = 0;
433  SemaRef.CheckFunctionDeclaration(Function, PrevDecl, Redeclaration,
434                                   /*FIXME:*/OverloadableAttrRequired);
435
436  if (FunctionTemplate) {
437    // Record this function template specialization.
438    Function->setFunctionTemplateSpecialization(SemaRef.Context,
439                                                FunctionTemplate,
440                                                &TemplateArgs,
441                                                InsertPos);
442  }
443
444  // If this was a friend function decl, it's a member which
445  // needs to be added.
446  if (isa<FriendFunctionDecl>(Function)) {
447    // If the new context is still dependent, this declaration
448    // needs to remain hidden.
449    if (Owner->isDependentContext())
450      Owner->addHiddenDecl(Function);
451    else
452      Owner->addDecl(Function);
453  }
454
455  return Function;
456}
457
458Decl *TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D) {
459  // Check whether there is already a function template specialization for
460  // this declaration.
461  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
462  void *InsertPos = 0;
463  if (FunctionTemplate) {
464    llvm::FoldingSetNodeID ID;
465    FunctionTemplateSpecializationInfo::Profile(ID,
466                                          TemplateArgs.getFlatArgumentList(),
467                                                TemplateArgs.flat_size(),
468                                                SemaRef.Context);
469
470    FunctionTemplateSpecializationInfo *Info
471      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
472                                                                   InsertPos);
473
474    // If we already have a function template specialization, return it.
475    if (Info)
476      return Info->Function;
477  }
478
479  Sema::LocalInstantiationScope Scope(SemaRef);
480
481  llvm::SmallVector<ParmVarDecl *, 4> Params;
482  QualType T = InstantiateFunctionType(D, Params);
483  if (T.isNull())
484    return 0;
485
486  // Build the instantiated method declaration.
487  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
488  CXXMethodDecl *Method = 0;
489
490  DeclarationName Name = D->getDeclName();
491  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
492    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
493    Name = SemaRef.Context.DeclarationNames.getCXXConstructorName(
494                                    SemaRef.Context.getCanonicalType(ClassTy));
495    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
496                                        Constructor->getLocation(),
497                                        Name, T,
498                                        Constructor->getDeclaratorInfo(),
499                                        Constructor->isExplicit(),
500                                        Constructor->isInline(), false);
501  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
502    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
503    Name = SemaRef.Context.DeclarationNames.getCXXDestructorName(
504                                   SemaRef.Context.getCanonicalType(ClassTy));
505    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
506                                       Destructor->getLocation(), Name,
507                                       T, Destructor->isInline(), false);
508  } else {
509    Method = CXXMethodDecl::Create(SemaRef.Context, Record, D->getLocation(),
510                                   D->getDeclName(), T, D->getDeclaratorInfo(),
511                                   D->isStatic(), D->isInline());
512  }
513
514  if (!FunctionTemplate)
515    Method->setInstantiationOfMemberFunction(D);
516
517  // If we are instantiating a member function defined
518  // out-of-line, the instantiation will have the same lexical
519  // context (which will be a namespace scope) as the template.
520  if (D->isOutOfLine())
521    Method->setLexicalDeclContext(D->getLexicalDeclContext());
522
523  // Attach the parameters
524  for (unsigned P = 0; P < Params.size(); ++P)
525    Params[P]->setOwningFunction(Method);
526  Method->setParams(SemaRef.Context, Params.data(), Params.size());
527
528  if (InitMethodInstantiation(Method, D))
529    Method->setInvalidDecl();
530
531  NamedDecl *PrevDecl = 0;
532
533  if (!FunctionTemplate) {
534    PrevDecl = SemaRef.LookupQualifiedName(Owner, Name,
535                                           Sema::LookupOrdinaryName, true);
536
537    // In C++, the previous declaration we find might be a tag type
538    // (class or enum). In this case, the new declaration will hide the
539    // tag type. Note that this does does not apply if we're declaring a
540    // typedef (C++ [dcl.typedef]p4).
541    if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag)
542      PrevDecl = 0;
543  }
544
545  bool Redeclaration = false;
546  bool OverloadableAttrRequired = false;
547  SemaRef.CheckFunctionDeclaration(Method, PrevDecl, Redeclaration,
548                                   /*FIXME:*/OverloadableAttrRequired);
549
550  if (FunctionTemplate)
551    // Record this function template specialization.
552    Method->setFunctionTemplateSpecialization(SemaRef.Context,
553                                              FunctionTemplate,
554                                              &TemplateArgs,
555                                              InsertPos);
556  else if (!Method->isInvalidDecl() || !PrevDecl)
557    Owner->addDecl(Method);
558
559  return Method;
560}
561
562Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
563  return VisitCXXMethodDecl(D);
564}
565
566Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
567  return VisitCXXMethodDecl(D);
568}
569
570Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
571  // FIXME: Look for existing, explicit specializations.
572  Sema::LocalInstantiationScope Scope(SemaRef);
573
574  llvm::SmallVector<ParmVarDecl *, 4> Params;
575  QualType T = InstantiateFunctionType(D, Params);
576  if (T.isNull())
577    return 0;
578  assert(Params.size() == 0 && "Destructor with parameters?");
579
580  // Build the instantiated conversion declaration.
581  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
582  QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
583  CanQualType ConvTy
584    = SemaRef.Context.getCanonicalType(T->getAsFunctionType()->getResultType());
585  CXXConversionDecl *Conversion
586    = CXXConversionDecl::Create(SemaRef.Context, Record,
587                                D->getLocation(),
588         SemaRef.Context.DeclarationNames.getCXXConversionFunctionName(ConvTy),
589                                T, D->getDeclaratorInfo(),
590                                D->isInline(), D->isExplicit());
591  Conversion->setInstantiationOfMemberFunction(D);
592  if (InitMethodInstantiation(Conversion, D))
593    Conversion->setInvalidDecl();
594
595  bool Redeclaration = false;
596  bool OverloadableAttrRequired = false;
597  NamedDecl *PrevDecl = 0;
598  SemaRef.CheckFunctionDeclaration(Conversion, PrevDecl, Redeclaration,
599                                   /*FIXME:*/OverloadableAttrRequired);
600  Owner->addDecl(Conversion);
601  return Conversion;
602}
603
604ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
605  QualType OrigT = SemaRef.InstantiateType(D->getOriginalType(), TemplateArgs,
606                                           D->getLocation(), D->getDeclName());
607  if (OrigT.isNull())
608    return 0;
609
610  QualType T = SemaRef.adjustParameterType(OrigT);
611
612  if (D->getDefaultArg()) {
613    // FIXME: Leave a marker for "uninstantiated" default
614    // arguments. They only get instantiated on demand at the call
615    // site.
616    unsigned DiagID = SemaRef.Diags.getCustomDiagID(Diagnostic::Warning,
617        "sorry, dropping default argument during template instantiation");
618    SemaRef.Diag(D->getDefaultArg()->getSourceRange().getBegin(), DiagID)
619      << D->getDefaultArg()->getSourceRange();
620  }
621
622  // Allocate the parameter
623  ParmVarDecl *Param = 0;
624  if (T == OrigT)
625    Param = ParmVarDecl::Create(SemaRef.Context, Owner, D->getLocation(),
626                                D->getIdentifier(), T, D->getDeclaratorInfo(),
627                                D->getStorageClass(), 0);
628  else
629    Param = OriginalParmVarDecl::Create(SemaRef.Context, Owner,
630                                        D->getLocation(), D->getIdentifier(),
631                                        T, D->getDeclaratorInfo(), OrigT,
632                                        D->getStorageClass(), 0);
633
634  // Note: we don't try to instantiate function parameters until after
635  // we've instantiated the function's type. Therefore, we don't have
636  // to check for 'void' parameter types here.
637  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
638  return Param;
639}
640
641Decl *
642TemplateDeclInstantiator::VisitOriginalParmVarDecl(OriginalParmVarDecl *D) {
643  // Since parameter types can decay either before or after
644  // instantiation, we simply treat OriginalParmVarDecls as
645  // ParmVarDecls the same way, and create one or the other depending
646  // on what happens after template instantiation.
647  return VisitParmVarDecl(D);
648}
649
650Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
651                                                    TemplateTypeParmDecl *D) {
652  // TODO: don't always clone when decls are refcounted.
653  const Type* T = D->getTypeForDecl();
654  assert(T->isTemplateTypeParmType());
655  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
656
657  TemplateTypeParmDecl *Inst =
658    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
659                                 TTPT->getDepth(), TTPT->getIndex(),
660                                 TTPT->getName(),
661                                 D->wasDeclaredWithTypename(),
662                                 D->isParameterPack());
663
664  if (D->hasDefaultArgument()) {
665    QualType DefaultPattern = D->getDefaultArgument();
666    QualType DefaultInst
667      = SemaRef.InstantiateType(DefaultPattern, TemplateArgs,
668                                D->getDefaultArgumentLoc(),
669                                D->getDeclName());
670
671    Inst->setDefaultArgument(DefaultInst,
672                             D->getDefaultArgumentLoc(),
673                             D->defaultArgumentWasInherited() /* preserve? */);
674  }
675
676  return Inst;
677}
678
679Decl *Sema::InstantiateDecl(Decl *D, DeclContext *Owner,
680                            const TemplateArgumentList &TemplateArgs) {
681  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
682  return Instantiator.Visit(D);
683}
684
685/// \brief Instantiates a nested template parameter list in the current
686/// instantiation context.
687///
688/// \param L The parameter list to instantiate
689///
690/// \returns NULL if there was an error
691TemplateParameterList *
692TemplateDeclInstantiator::InstantiateTemplateParams(TemplateParameterList *L) {
693  // Get errors for all the parameters before bailing out.
694  bool Invalid = false;
695
696  unsigned N = L->size();
697  typedef llvm::SmallVector<Decl*,8> ParamVector;
698  ParamVector Params;
699  Params.reserve(N);
700  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
701       PI != PE; ++PI) {
702    Decl *D = Visit(*PI);
703    Params.push_back(D);
704    Invalid = Invalid || !D;
705  }
706
707  // Clean up if we had an error.
708  if (Invalid) {
709    for (ParamVector::iterator PI = Params.begin(), PE = Params.end();
710         PI != PE; ++PI)
711      if (*PI)
712        (*PI)->Destroy(SemaRef.Context);
713    return NULL;
714  }
715
716  TemplateParameterList *InstL
717    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
718                                    L->getLAngleLoc(), &Params.front(), N,
719                                    L->getRAngleLoc());
720  return InstL;
721}
722
723/// \brief Instantiates the type of the given function, including
724/// instantiating all of the function parameters.
725///
726/// \param D The function that we will be instantiated
727///
728/// \param Params the instantiated parameter declarations
729
730/// \returns the instantiated function's type if successfull, a NULL
731/// type if there was an error.
732QualType
733TemplateDeclInstantiator::InstantiateFunctionType(FunctionDecl *D,
734                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
735  bool InvalidDecl = false;
736
737  // Instantiate the function parameters
738  TemplateDeclInstantiator ParamInstantiator(SemaRef, 0, TemplateArgs);
739  llvm::SmallVector<QualType, 4> ParamTys;
740  for (FunctionDecl::param_iterator P = D->param_begin(),
741                                 PEnd = D->param_end();
742       P != PEnd; ++P) {
743    if (ParmVarDecl *PInst = ParamInstantiator.VisitParmVarDecl(*P)) {
744      if (PInst->getType()->isVoidType()) {
745        SemaRef.Diag(PInst->getLocation(), diag::err_param_with_void_type);
746        PInst->setInvalidDecl();
747      } else if (SemaRef.RequireNonAbstractType(PInst->getLocation(),
748                                                PInst->getType(),
749                                                diag::err_abstract_type_in_decl,
750                                                Sema::AbstractParamType))
751        PInst->setInvalidDecl();
752
753      Params.push_back(PInst);
754      ParamTys.push_back(PInst->getType());
755
756      if (PInst->isInvalidDecl())
757        InvalidDecl = true;
758    } else
759      InvalidDecl = true;
760  }
761
762  // FIXME: Deallocate dead declarations.
763  if (InvalidDecl)
764    return QualType();
765
766  const FunctionProtoType *Proto = D->getType()->getAsFunctionProtoType();
767  assert(Proto && "Missing prototype?");
768  QualType ResultType
769    = SemaRef.InstantiateType(Proto->getResultType(), TemplateArgs,
770                              D->getLocation(), D->getDeclName());
771  if (ResultType.isNull())
772    return QualType();
773
774  return SemaRef.BuildFunctionType(ResultType, ParamTys.data(), ParamTys.size(),
775                                   Proto->isVariadic(), Proto->getTypeQuals(),
776                                   D->getLocation(), D->getDeclName());
777}
778
779/// \brief Initializes the common fields of an instantiation function
780/// declaration (New) from the corresponding fields of its template (Tmpl).
781///
782/// \returns true if there was an error
783bool
784TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
785                                                    FunctionDecl *Tmpl) {
786  if (Tmpl->isDeleted())
787    New->setDeleted();
788
789  // If we are performing substituting explicitly-specified template arguments
790  // or deduced template arguments into a function template and we reach this
791  // point, we are now past the point where SFINAE applies and have committed
792  // to keeping the new function template specialization. We therefore
793  // convert the active template instantiation for the function template
794  // into a template instantiation for this specific function template
795  // specialization, which is not a SFINAE context, so that we diagnose any
796  // further errors in the declaration itself.
797  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
798  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
799  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
800      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
801    if (FunctionTemplateDecl *FunTmpl
802          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
803      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
804             "Deduction from the wrong function template?");
805      (void) FunTmpl;
806      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
807      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
808    }
809  }
810
811  return false;
812}
813
814/// \brief Initializes common fields of an instantiated method
815/// declaration (New) from the corresponding fields of its template
816/// (Tmpl).
817///
818/// \returns true if there was an error
819bool
820TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
821                                                  CXXMethodDecl *Tmpl) {
822  if (InitFunctionInstantiation(New, Tmpl))
823    return true;
824
825  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
826  New->setAccess(Tmpl->getAccess());
827  if (Tmpl->isVirtualAsWritten()) {
828    New->setVirtualAsWritten(true);
829    Record->setAggregate(false);
830    Record->setPOD(false);
831    Record->setEmpty(false);
832    Record->setPolymorphic(true);
833  }
834  if (Tmpl->isPure()) {
835    New->setPure();
836    Record->setAbstract(true);
837  }
838
839  // FIXME: attributes
840  // FIXME: New needs a pointer to Tmpl
841  return false;
842}
843
844/// \brief Instantiate the definition of the given function from its
845/// template.
846///
847/// \param PointOfInstantiation the point at which the instantiation was
848/// required. Note that this is not precisely a "point of instantiation"
849/// for the function, but it's close.
850///
851/// \param Function the already-instantiated declaration of a
852/// function template specialization or member function of a class template
853/// specialization.
854///
855/// \param Recursive if true, recursively instantiates any functions that
856/// are required by this instantiation.
857void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
858                                         FunctionDecl *Function,
859                                         bool Recursive) {
860  if (Function->isInvalidDecl())
861    return;
862
863  assert(!Function->getBody() && "Already instantiated!");
864
865  // Find the function body that we'll be substituting.
866  const FunctionDecl *PatternDecl = 0;
867  if (FunctionTemplateDecl *Primary = Function->getPrimaryTemplate())
868    PatternDecl = Primary->getTemplatedDecl();
869  else
870    PatternDecl = Function->getInstantiatedFromMemberFunction();
871  Stmt *Pattern = 0;
872  if (PatternDecl)
873    Pattern = PatternDecl->getBody(PatternDecl);
874
875  if (!Pattern)
876    return;
877
878  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
879  if (Inst)
880    return;
881
882  // If we're performing recursive template instantiation, create our own
883  // queue of pending implicit instantiations that we will instantiate later,
884  // while we're still within our own instantiation context.
885  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
886  if (Recursive)
887    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
888
889  ActOnStartOfFunctionDef(0, DeclPtrTy::make(Function));
890
891  // Introduce a new scope where local variable instantiations will be
892  // recorded.
893  LocalInstantiationScope Scope(*this);
894
895  // Introduce the instantiated function parameters into the local
896  // instantiation scope.
897  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I)
898    Scope.InstantiatedLocal(PatternDecl->getParamDecl(I),
899                            Function->getParamDecl(I));
900
901  // Enter the scope of this instantiation. We don't use
902  // PushDeclContext because we don't have a scope.
903  DeclContext *PreviousContext = CurContext;
904  CurContext = Function;
905
906  // Instantiate the function body.
907  OwningStmtResult Body
908    = InstantiateStmt(Pattern, getTemplateInstantiationArgs(Function));
909
910  ActOnFinishFunctionBody(DeclPtrTy::make(Function), move(Body),
911                          /*IsInstantiation=*/true);
912
913  CurContext = PreviousContext;
914
915  DeclGroupRef DG(Function);
916  Consumer.HandleTopLevelDecl(DG);
917
918  if (Recursive) {
919    // Instantiate any pending implicit instantiations found during the
920    // instantiation of this template.
921    PerformPendingImplicitInstantiations();
922
923    // Restore the set of pending implicit instantiations.
924    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
925  }
926}
927
928/// \brief Instantiate the definition of the given variable from its
929/// template.
930///
931/// \param PointOfInstantiation the point at which the instantiation was
932/// required. Note that this is not precisely a "point of instantiation"
933/// for the function, but it's close.
934///
935/// \param Var the already-instantiated declaration of a static member
936/// variable of a class template specialization.
937///
938/// \param Recursive if true, recursively instantiates any functions that
939/// are required by this instantiation.
940void Sema::InstantiateStaticDataMemberDefinition(
941                                          SourceLocation PointOfInstantiation,
942                                                 VarDecl *Var,
943                                                 bool Recursive) {
944  if (Var->isInvalidDecl())
945    return;
946
947  // Find the out-of-line definition of this static data member.
948  // FIXME: Do we have to look for specializations separately?
949  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
950  bool FoundOutOfLineDef = false;
951  assert(Def && "This data member was not instantiated from a template?");
952  assert(Def->isStaticDataMember() && "Not a static data member?");
953  for (VarDecl::redecl_iterator RD = Def->redecls_begin(),
954                             RDEnd = Def->redecls_end();
955       RD != RDEnd; ++RD) {
956    if (RD->getLexicalDeclContext()->isFileContext()) {
957      Def = *RD;
958      FoundOutOfLineDef = true;
959    }
960  }
961
962  if (!FoundOutOfLineDef) {
963    // We did not find an out-of-line definition of this static data member,
964    // so we won't perform any instantiation. Rather, we rely on the user to
965    // instantiate this definition (or provide a specialization for it) in
966    // another translation unit.
967    return;
968  }
969
970  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
971  if (Inst)
972    return;
973
974  // If we're performing recursive template instantiation, create our own
975  // queue of pending implicit instantiations that we will instantiate later,
976  // while we're still within our own instantiation context.
977  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
978  if (Recursive)
979    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
980
981  // Enter the scope of this instantiation. We don't use
982  // PushDeclContext because we don't have a scope.
983  DeclContext *PreviousContext = CurContext;
984  CurContext = Var->getDeclContext();
985
986#if 0
987  // Instantiate the initializer of this static data member.
988  OwningExprResult Init
989    = InstantiateExpr(Def->getInit(), getTemplateInstantiationArgs(Var));
990  if (Init.isInvalid()) {
991    // If instantiation of the initializer failed, mark the declaration invalid
992    // and don't instantiate anything else that was triggered by this
993    // instantiation.
994    Var->setInvalidDecl();
995
996    // Restore the set of pending implicit instantiations.
997    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
998
999    return;
1000  }
1001
1002  // Type-check the initializer.
1003  if (Init.get())
1004    AddInitializerToDecl(DeclPtrTy::make(Var), move(Init),
1005                         Def->hasCXXDirectInitializer());
1006  else
1007    ActOnUninitializedDecl(DeclPtrTy::make(Var), false);
1008#else
1009  Var = cast_or_null<VarDecl>(InstantiateDecl(Def, Var->getDeclContext(),
1010                                          getTemplateInstantiationArgs(Var)));
1011#endif
1012
1013  CurContext = PreviousContext;
1014
1015  if (Var) {
1016    DeclGroupRef DG(Var);
1017    Consumer.HandleTopLevelDecl(DG);
1018  }
1019
1020  if (Recursive) {
1021    // Instantiate any pending implicit instantiations found during the
1022    // instantiation of this template.
1023    PerformPendingImplicitInstantiations();
1024
1025    // Restore the set of pending implicit instantiations.
1026    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1027  }
1028}
1029
1030static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
1031  if (D->getKind() != Other->getKind())
1032    return false;
1033
1034  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
1035    return Record->getInstantiatedFromMemberClass()->getCanonicalDecl()
1036             == D->getCanonicalDecl();
1037
1038  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
1039    return Function->getInstantiatedFromMemberFunction()->getCanonicalDecl()
1040             == D->getCanonicalDecl();
1041
1042  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
1043    return Enum->getInstantiatedFromMemberEnum()->getCanonicalDecl()
1044             == D->getCanonicalDecl();
1045
1046  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
1047    if (Var->isStaticDataMember())
1048      return Var->getInstantiatedFromStaticDataMember()->getCanonicalDecl()
1049               == D->getCanonicalDecl();
1050
1051  // FIXME: How can we find instantiations of anonymous unions?
1052
1053  return D->getDeclName() && isa<NamedDecl>(Other) &&
1054    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
1055}
1056
1057template<typename ForwardIterator>
1058static NamedDecl *findInstantiationOf(ASTContext &Ctx,
1059                                      NamedDecl *D,
1060                                      ForwardIterator first,
1061                                      ForwardIterator last) {
1062  for (; first != last; ++first)
1063    if (isInstantiationOf(Ctx, D, *first))
1064      return cast<NamedDecl>(*first);
1065
1066  return 0;
1067}
1068
1069/// \brief Find the instantiation of the given declaration within the
1070/// current instantiation.
1071///
1072/// This routine is intended to be used when \p D is a declaration
1073/// referenced from within a template, that needs to mapped into the
1074/// corresponding declaration within an instantiation. For example,
1075/// given:
1076///
1077/// \code
1078/// template<typename T>
1079/// struct X {
1080///   enum Kind {
1081///     KnownValue = sizeof(T)
1082///   };
1083///
1084///   bool getKind() const { return KnownValue; }
1085/// };
1086///
1087/// template struct X<int>;
1088/// \endcode
1089///
1090/// In the instantiation of X<int>::getKind(), we need to map the
1091/// EnumConstantDecl for KnownValue (which refers to
1092/// X<T>::<Kind>::KnownValue) to its instantiation
1093/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
1094/// this mapping from within the instantiation of X<int>.
1095NamedDecl * Sema::InstantiateCurrentDeclRef(NamedDecl *D) {
1096  DeclContext *ParentDC = D->getDeclContext();
1097  if (isa<ParmVarDecl>(D) || ParentDC->isFunctionOrMethod()) {
1098    // D is a local of some kind. Look into the map of local
1099    // declarations to their instantiations.
1100    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
1101  }
1102
1103  if (NamedDecl *ParentDecl = dyn_cast<NamedDecl>(ParentDC)) {
1104    ParentDecl = InstantiateCurrentDeclRef(ParentDecl);
1105    if (!ParentDecl)
1106      return 0;
1107
1108    ParentDC = cast<DeclContext>(ParentDecl);
1109  }
1110
1111  if (ParentDC != D->getDeclContext()) {
1112    // We performed some kind of instantiation in the parent context,
1113    // so now we need to look into the instantiated parent context to
1114    // find the instantiation of the declaration D.
1115    NamedDecl *Result = 0;
1116    if (D->getDeclName()) {
1117      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
1118      Result = findInstantiationOf(Context, D, Found.first, Found.second);
1119    } else {
1120      // Since we don't have a name for the entity we're looking for,
1121      // our only option is to walk through all of the declarations to
1122      // find that name. This will occur in a few cases:
1123      //
1124      //   - anonymous struct/union within a template
1125      //   - unnamed class/struct/union/enum within a template
1126      //
1127      // FIXME: Find a better way to find these instantiations!
1128      Result = findInstantiationOf(Context, D,
1129                                   ParentDC->decls_begin(),
1130                                   ParentDC->decls_end());
1131    }
1132    assert(Result && "Unable to find instantiation of declaration!");
1133    D = Result;
1134  }
1135
1136  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D))
1137    if (ClassTemplateDecl *ClassTemplate
1138          = Record->getDescribedClassTemplate()) {
1139      // When the declaration D was parsed, it referred to the current
1140      // instantiation. Therefore, look through the current context,
1141      // which contains actual instantiations, to find the
1142      // instantiation of the "current instantiation" that D refers
1143      // to. Alternatively, we could just instantiate the
1144      // injected-class-name with the current template arguments, but
1145      // such an instantiation is far more expensive.
1146      for (DeclContext *DC = CurContext; !DC->isFileContext();
1147           DC = DC->getParent()) {
1148        if (ClassTemplateSpecializationDecl *Spec
1149              = dyn_cast<ClassTemplateSpecializationDecl>(DC))
1150          if (Spec->getSpecializedTemplate()->getCanonicalDecl()
1151              == ClassTemplate->getCanonicalDecl())
1152            return Spec;
1153      }
1154
1155      assert(false &&
1156             "Unable to find declaration for the current instantiation");
1157    }
1158
1159  return D;
1160}
1161
1162/// \brief Performs template instantiation for all implicit template
1163/// instantiations we have seen until this point.
1164void Sema::PerformPendingImplicitInstantiations() {
1165  while (!PendingImplicitInstantiations.empty()) {
1166    PendingImplicitInstantiation Inst = PendingImplicitInstantiations.front();
1167    PendingImplicitInstantiations.pop_front();
1168
1169    // Instantiate function definitions
1170    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
1171      if (!Function->getBody())
1172        InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true);
1173      continue;
1174    }
1175
1176    // Instantiate static data member definitions.
1177    VarDecl *Var = cast<VarDecl>(Inst.first);
1178    assert(Var->isStaticDataMember() && "Not a static data member?");
1179    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true);
1180  }
1181}
1182