SemaTemplateInstantiateDecl.cpp revision 80f0075a200e7c7cec5a986723955a4285dcd82b 
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 "clang/Basic/PrettyStackTrace.h"
19#include "clang/Lex/Preprocessor.h"
20#include "llvm/Support/Compiler.h"
21
22using namespace clang;
23
24namespace {
25  class VISIBILITY_HIDDEN TemplateDeclInstantiator
26    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
27    Sema &SemaRef;
28    DeclContext *Owner;
29    const MultiLevelTemplateArgumentList &TemplateArgs;
30
31  public:
32    typedef Sema::OwningExprResult OwningExprResult;
33
34    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
35                             const MultiLevelTemplateArgumentList &TemplateArgs)
36      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
37
38    // FIXME: Once we get closer to completion, replace these manually-written
39    // declarations with automatically-generated ones from
40    // clang/AST/DeclNodes.def.
41    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
42    Decl *VisitNamespaceDecl(NamespaceDecl *D);
43    Decl *VisitTypedefDecl(TypedefDecl *D);
44    Decl *VisitVarDecl(VarDecl *D);
45    Decl *VisitFieldDecl(FieldDecl *D);
46    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
47    Decl *VisitEnumDecl(EnumDecl *D);
48    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
49    Decl *VisitFriendDecl(FriendDecl *D);
50    Decl *VisitFunctionDecl(FunctionDecl *D);
51    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
52    Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
53                             TemplateParameterList *TemplateParams = 0);
54    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
55    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
56    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
57    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
58    Decl *VisitOriginalParmVarDecl(OriginalParmVarDecl *D);
59    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
60    Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
61    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
62    Decl *VisitUnresolvedUsingDecl(UnresolvedUsingDecl *D);
63
64    // Base case. FIXME: Remove once we can instantiate everything.
65    Decl *VisitDecl(Decl *) {
66      assert(false && "Template instantiation of unknown declaration kind!");
67      return 0;
68    }
69
70    const LangOptions &getLangOptions() {
71      return SemaRef.getLangOptions();
72    }
73
74    // Helper functions for instantiating methods.
75    QualType SubstFunctionType(FunctionDecl *D,
76                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
77    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
78    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
79
80    TemplateParameterList *
81      SubstTemplateParams(TemplateParameterList *List);
82  };
83}
84
85Decl *
86TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
87  assert(false && "Translation units cannot be instantiated");
88  return D;
89}
90
91Decl *
92TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
93  assert(false && "Namespaces cannot be instantiated");
94  return D;
95}
96
97Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
98  bool Invalid = false;
99  QualType T = D->getUnderlyingType();
100  if (T->isDependentType()) {
101    T = SemaRef.SubstType(T, TemplateArgs,
102                          D->getLocation(), D->getDeclName());
103    if (T.isNull()) {
104      Invalid = true;
105      T = SemaRef.Context.IntTy;
106    }
107  }
108
109  // Create the new typedef
110  TypedefDecl *Typedef
111    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
112                          D->getIdentifier(), T);
113  if (Invalid)
114    Typedef->setInvalidDecl();
115
116  Owner->addDecl(Typedef);
117
118  return Typedef;
119}
120
121Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
122  // Do substitution on the type of the declaration
123  QualType T = SemaRef.SubstType(D->getType(), TemplateArgs,
124                                 D->getTypeSpecStartLoc(),
125                                 D->getDeclName());
126  if (T.isNull())
127    return 0;
128
129  // Build the instantiated declaration
130  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
131                                 D->getLocation(), D->getIdentifier(),
132                                 T, D->getDeclaratorInfo(),
133                                 D->getStorageClass());
134  Var->setThreadSpecified(D->isThreadSpecified());
135  Var->setCXXDirectInitializer(D->hasCXXDirectInitializer());
136  Var->setDeclaredInCondition(D->isDeclaredInCondition());
137
138  // If we are instantiating a static data member defined
139  // out-of-line, the instantiation will have the same lexical
140  // context (which will be a namespace scope) as the template.
141  if (D->isOutOfLine())
142    Var->setLexicalDeclContext(D->getLexicalDeclContext());
143
144  // FIXME: In theory, we could have a previous declaration for variables that
145  // are not static data members.
146  bool Redeclaration = false;
147  SemaRef.CheckVariableDeclaration(Var, 0, Redeclaration);
148
149  if (D->isOutOfLine()) {
150    D->getLexicalDeclContext()->addDecl(Var);
151    Owner->makeDeclVisibleInContext(Var);
152  } else {
153    Owner->addDecl(Var);
154  }
155
156  if (D->getInit()) {
157    OwningExprResult Init
158      = SemaRef.SubstExpr(D->getInit(), TemplateArgs);
159    if (Init.isInvalid())
160      Var->setInvalidDecl();
161    else if (ParenListExpr *PLE = dyn_cast<ParenListExpr>((Expr *)Init.get())) {
162      // FIXME: We're faking all of the comma locations, which is suboptimal.
163      // Do we even need these comma locations?
164      llvm::SmallVector<SourceLocation, 4> FakeCommaLocs;
165      if (PLE->getNumExprs() > 0) {
166        FakeCommaLocs.reserve(PLE->getNumExprs() - 1);
167        for (unsigned I = 0, N = PLE->getNumExprs() - 1; I != N; ++I) {
168          Expr *E = PLE->getExpr(I)->Retain();
169          FakeCommaLocs.push_back(
170                                SemaRef.PP.getLocForEndOfToken(E->getLocEnd()));
171        }
172        PLE->getExpr(PLE->getNumExprs() - 1)->Retain();
173      }
174
175      // Add the direct initializer to the declaration.
176      SemaRef.AddCXXDirectInitializerToDecl(Sema::DeclPtrTy::make(Var),
177                                            PLE->getLParenLoc(),
178                                            Sema::MultiExprArg(SemaRef,
179                                                       (void**)PLE->getExprs(),
180                                                           PLE->getNumExprs()),
181                                            FakeCommaLocs.data(),
182                                            PLE->getRParenLoc());
183
184      // When Init is destroyed, it will destroy the instantiated ParenListExpr;
185      // we've explicitly retained all of its subexpressions already.
186    } else
187      SemaRef.AddInitializerToDecl(Sema::DeclPtrTy::make(Var), move(Init),
188                                   D->hasCXXDirectInitializer());
189  } else if (!Var->isStaticDataMember() || Var->isOutOfLine())
190    SemaRef.ActOnUninitializedDecl(Sema::DeclPtrTy::make(Var), false);
191
192  // Link instantiations of static data members back to the template from
193  // which they were instantiated.
194  if (Var->isStaticDataMember())
195    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D);
196
197  return Var;
198}
199
200Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
201  bool Invalid = false;
202  QualType T = D->getType();
203  if (T->isDependentType())  {
204    T = SemaRef.SubstType(T, TemplateArgs,
205                          D->getLocation(), D->getDeclName());
206    if (!T.isNull() && T->isFunctionType()) {
207      // C++ [temp.arg.type]p3:
208      //   If a declaration acquires a function type through a type
209      //   dependent on a template-parameter and this causes a
210      //   declaration that does not use the syntactic form of a
211      //   function declarator to have function type, the program is
212      //   ill-formed.
213      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
214        << T;
215      T = QualType();
216      Invalid = true;
217    }
218  }
219
220  Expr *BitWidth = D->getBitWidth();
221  if (Invalid)
222    BitWidth = 0;
223  else if (BitWidth) {
224    // The bit-width expression is not potentially evaluated.
225    EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
226
227    OwningExprResult InstantiatedBitWidth
228      = SemaRef.SubstExpr(BitWidth, TemplateArgs);
229    if (InstantiatedBitWidth.isInvalid()) {
230      Invalid = true;
231      BitWidth = 0;
232    } else
233      BitWidth = InstantiatedBitWidth.takeAs<Expr>();
234  }
235
236  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(), T,
237                                            D->getDeclaratorInfo(),
238                                            cast<RecordDecl>(Owner),
239                                            D->getLocation(),
240                                            D->isMutable(),
241                                            BitWidth,
242                                            D->getTypeSpecStartLoc(),
243                                            D->getAccess(),
244                                            0);
245  if (Field) {
246    if (Invalid)
247      Field->setInvalidDecl();
248
249    if (!Field->getDeclName()) {
250      // Keep track of where this decl came from.
251      SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
252    }
253
254    Owner->addDecl(Field);
255  }
256
257  return Field;
258}
259
260Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
261  FriendDecl::FriendUnion FU;
262
263  // Handle friend type expressions by simply substituting template
264  // parameters into the pattern type.
265  if (Type *Ty = D->getFriendType()) {
266    QualType T = SemaRef.SubstType(QualType(Ty,0), TemplateArgs,
267                                   D->getLocation(), DeclarationName());
268    if (T.isNull()) return 0;
269
270    assert(getLangOptions().CPlusPlus0x || T->isRecordType());
271    FU = T.getTypePtr();
272
273  // Handle everything else by appropriate substitution.
274  } else {
275    NamedDecl *ND = D->getFriendDecl();
276    assert(ND && "friend decl must be a decl or a type!");
277
278    Decl *NewND = Visit(ND);
279    if (!NewND) return 0;
280
281    FU = cast<NamedDecl>(NewND);
282  }
283
284  FriendDecl *FD =
285    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(), FU,
286                       D->getFriendLoc());
287  FD->setAccess(AS_public);
288  Owner->addDecl(FD);
289  return FD;
290}
291
292Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
293  Expr *AssertExpr = D->getAssertExpr();
294
295  // The expression in a static assertion is not potentially evaluated.
296  EnterExpressionEvaluationContext Unevaluated(SemaRef, Action::Unevaluated);
297
298  OwningExprResult InstantiatedAssertExpr
299    = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
300  if (InstantiatedAssertExpr.isInvalid())
301    return 0;
302
303  OwningExprResult Message(SemaRef, D->getMessage());
304  D->getMessage()->Retain();
305  Decl *StaticAssert
306    = SemaRef.ActOnStaticAssertDeclaration(D->getLocation(),
307                                           move(InstantiatedAssertExpr),
308                                           move(Message)).getAs<Decl>();
309  return StaticAssert;
310}
311
312Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
313  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner,
314                                    D->getLocation(), D->getIdentifier(),
315                                    D->getTagKeywordLoc(),
316                                    /*PrevDecl=*/0);
317  Enum->setInstantiationOfMemberEnum(D);
318  Enum->setAccess(D->getAccess());
319  Owner->addDecl(Enum);
320  Enum->startDefinition();
321
322  llvm::SmallVector<Sema::DeclPtrTy, 4> Enumerators;
323
324  EnumConstantDecl *LastEnumConst = 0;
325  for (EnumDecl::enumerator_iterator EC = D->enumerator_begin(),
326         ECEnd = D->enumerator_end();
327       EC != ECEnd; ++EC) {
328    // The specified value for the enumerator.
329    OwningExprResult Value = SemaRef.Owned((Expr *)0);
330    if (Expr *UninstValue = EC->getInitExpr()) {
331      // The enumerator's value expression is not potentially evaluated.
332      EnterExpressionEvaluationContext Unevaluated(SemaRef,
333                                                   Action::Unevaluated);
334
335      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
336    }
337
338    // Drop the initial value and continue.
339    bool isInvalid = false;
340    if (Value.isInvalid()) {
341      Value = SemaRef.Owned((Expr *)0);
342      isInvalid = true;
343    }
344
345    EnumConstantDecl *EnumConst
346      = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
347                                  EC->getLocation(), EC->getIdentifier(),
348                                  move(Value));
349
350    if (isInvalid) {
351      if (EnumConst)
352        EnumConst->setInvalidDecl();
353      Enum->setInvalidDecl();
354    }
355
356    if (EnumConst) {
357      Enum->addDecl(EnumConst);
358      Enumerators.push_back(Sema::DeclPtrTy::make(EnumConst));
359      LastEnumConst = EnumConst;
360    }
361  }
362
363  // FIXME: Fixup LBraceLoc and RBraceLoc
364  // FIXME: Empty Scope and AttributeList (required to handle attribute packed).
365  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), SourceLocation(),
366                        Sema::DeclPtrTy::make(Enum),
367                        &Enumerators[0], Enumerators.size(),
368                        0, 0);
369
370  return Enum;
371}
372
373Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
374  assert(false && "EnumConstantDecls can only occur within EnumDecls.");
375  return 0;
376}
377
378Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
379  TemplateParameterList *TempParams = D->getTemplateParameters();
380  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
381  if (!InstParams)
382    return NULL;
383
384  CXXRecordDecl *Pattern = D->getTemplatedDecl();
385  CXXRecordDecl *RecordInst
386    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), Owner,
387                            Pattern->getLocation(), Pattern->getIdentifier(),
388                            Pattern->getTagKeywordLoc(), /*PrevDecl=*/ NULL);
389
390  ClassTemplateDecl *Inst
391    = ClassTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
392                                D->getIdentifier(), InstParams, RecordInst, 0);
393  RecordInst->setDescribedClassTemplate(Inst);
394  Inst->setAccess(D->getAccess());
395  Inst->setInstantiatedFromMemberTemplate(D);
396
397  Owner->addDecl(Inst);
398  return Inst;
399}
400
401Decl *
402TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
403  TemplateParameterList *TempParams = D->getTemplateParameters();
404  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
405  if (!InstParams)
406    return NULL;
407
408  // FIXME: Handle instantiation of nested function templates that aren't
409  // member function templates. This could happen inside a FriendDecl.
410  assert(isa<CXXMethodDecl>(D->getTemplatedDecl()));
411  CXXMethodDecl *InstMethod
412    = cast_or_null<CXXMethodDecl>(
413                 VisitCXXMethodDecl(cast<CXXMethodDecl>(D->getTemplatedDecl()),
414                                    InstParams));
415  if (!InstMethod)
416    return 0;
417
418  // Link the instantiated function template declaration to the function
419  // template from which it was instantiated.
420  FunctionTemplateDecl *InstTemplate = InstMethod->getDescribedFunctionTemplate();
421  assert(InstTemplate && "VisitCXXMethodDecl didn't create a template!");
422  InstTemplate->setInstantiatedFromMemberTemplate(D);
423  Owner->addDecl(InstTemplate);
424  return InstTemplate;
425}
426
427Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
428  CXXRecordDecl *PrevDecl = 0;
429  if (D->isInjectedClassName())
430    PrevDecl = cast<CXXRecordDecl>(Owner);
431
432  CXXRecordDecl *Record
433    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
434                            D->getLocation(), D->getIdentifier(),
435                            D->getTagKeywordLoc(), PrevDecl);
436  Record->setImplicit(D->isImplicit());
437  // FIXME: Check against AS_none is an ugly hack to work around the issue that
438  // the tag decls introduced by friend class declarations don't have an access
439  // specifier. Remove once this area of the code gets sorted out.
440  if (D->getAccess() != AS_none)
441    Record->setAccess(D->getAccess());
442  if (!D->isInjectedClassName())
443    Record->setInstantiationOfMemberClass(D);
444
445  // If the original function was part of a friend declaration,
446  // inherit its namespace state.
447  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind())
448    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared);
449
450  Record->setAnonymousStructOrUnion(D->isAnonymousStructOrUnion());
451
452  Owner->addDecl(Record);
453  return Record;
454}
455
456/// Normal class members are of more specific types and therefore
457/// don't make it here.  This function serves two purposes:
458///   1) instantiating function templates
459///   2) substituting friend declarations
460/// FIXME: preserve function definitions in case #2
461Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D) {
462  // Check whether there is already a function template specialization for
463  // this declaration.
464  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
465  void *InsertPos = 0;
466  if (FunctionTemplate) {
467    llvm::FoldingSetNodeID ID;
468    FunctionTemplateSpecializationInfo::Profile(ID,
469                             TemplateArgs.getInnermost().getFlatArgumentList(),
470                                       TemplateArgs.getInnermost().flat_size(),
471                                                SemaRef.Context);
472
473    FunctionTemplateSpecializationInfo *Info
474      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
475                                                                   InsertPos);
476
477    // If we already have a function template specialization, return it.
478    if (Info)
479      return Info->Function;
480  }
481
482  Sema::LocalInstantiationScope Scope(SemaRef);
483
484  llvm::SmallVector<ParmVarDecl *, 4> Params;
485  QualType T = SubstFunctionType(D, Params);
486  if (T.isNull())
487    return 0;
488
489  // Build the instantiated method declaration.
490  DeclContext *DC = SemaRef.FindInstantiatedContext(D->getDeclContext());
491  FunctionDecl *Function =
492      FunctionDecl::Create(SemaRef.Context, DC, D->getLocation(),
493                           D->getDeclName(), T, D->getDeclaratorInfo(),
494                           D->getStorageClass(),
495                           D->isInline(), D->hasWrittenPrototype());
496  Function->setLexicalDeclContext(Owner);
497
498  // Attach the parameters
499  for (unsigned P = 0; P < Params.size(); ++P)
500    Params[P]->setOwningFunction(Function);
501  Function->setParams(SemaRef.Context, Params.data(), Params.size());
502
503  // If the original function was part of a friend declaration,
504  // inherit its namespace state and add it to the owner.
505  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind()) {
506    bool WasDeclared = (FOK == Decl::FOK_Declared);
507    Function->setObjectOfFriendDecl(WasDeclared);
508    if (!Owner->isDependentContext())
509      DC->makeDeclVisibleInContext(Function, /* Recoverable = */ false);
510
511    Function->setInstantiationOfMemberFunction(D);
512  }
513
514  if (InitFunctionInstantiation(Function, D))
515    Function->setInvalidDecl();
516
517  bool Redeclaration = false;
518  bool OverloadableAttrRequired = false;
519  NamedDecl *PrevDecl = 0;
520  SemaRef.CheckFunctionDeclaration(Function, PrevDecl, Redeclaration,
521                                   /*FIXME:*/OverloadableAttrRequired);
522
523  if (FunctionTemplate) {
524    // Record this function template specialization.
525    Function->setFunctionTemplateSpecialization(SemaRef.Context,
526                                                FunctionTemplate,
527                                                &TemplateArgs.getInnermost(),
528                                                InsertPos);
529  }
530
531  return Function;
532}
533
534Decl *
535TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
536                                      TemplateParameterList *TemplateParams) {
537  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
538  void *InsertPos = 0;
539  if (FunctionTemplate && !TemplateParams) {
540    // We are creating a function template specialization from a function
541    // template. Check whether there is already a function template
542    // specialization for this particular set of template arguments.
543    llvm::FoldingSetNodeID ID;
544    FunctionTemplateSpecializationInfo::Profile(ID,
545                            TemplateArgs.getInnermost().getFlatArgumentList(),
546                                      TemplateArgs.getInnermost().flat_size(),
547                                                SemaRef.Context);
548
549    FunctionTemplateSpecializationInfo *Info
550      = FunctionTemplate->getSpecializations().FindNodeOrInsertPos(ID,
551                                                                   InsertPos);
552
553    // If we already have a function template specialization, return it.
554    if (Info)
555      return Info->Function;
556  }
557
558  Sema::LocalInstantiationScope Scope(SemaRef);
559
560  llvm::SmallVector<ParmVarDecl *, 4> Params;
561  QualType T = SubstFunctionType(D, Params);
562  if (T.isNull())
563    return 0;
564
565  // Build the instantiated method declaration.
566  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
567  CXXMethodDecl *Method = 0;
568
569  DeclarationName Name = D->getDeclName();
570  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
571    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
572    Name = SemaRef.Context.DeclarationNames.getCXXConstructorName(
573                                    SemaRef.Context.getCanonicalType(ClassTy));
574    Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
575                                        Constructor->getLocation(),
576                                        Name, T,
577                                        Constructor->getDeclaratorInfo(),
578                                        Constructor->isExplicit(),
579                                        Constructor->isInline(), false);
580  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
581    QualType ClassTy = SemaRef.Context.getTypeDeclType(Record);
582    Name = SemaRef.Context.DeclarationNames.getCXXDestructorName(
583                                   SemaRef.Context.getCanonicalType(ClassTy));
584    Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
585                                       Destructor->getLocation(), Name,
586                                       T, Destructor->isInline(), false);
587  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
588    CanQualType ConvTy
589      = SemaRef.Context.getCanonicalType(
590                                      T->getAsFunctionType()->getResultType());
591    Name = SemaRef.Context.DeclarationNames.getCXXConversionFunctionName(
592                                                                      ConvTy);
593    Method = CXXConversionDecl::Create(SemaRef.Context, Record,
594                                       Conversion->getLocation(), Name,
595                                       T, Conversion->getDeclaratorInfo(),
596                                       Conversion->isInline(),
597                                       Conversion->isExplicit());
598  } else {
599    Method = CXXMethodDecl::Create(SemaRef.Context, Record, D->getLocation(),
600                                   D->getDeclName(), T, D->getDeclaratorInfo(),
601                                   D->isStatic(), D->isInline());
602  }
603
604  if (TemplateParams) {
605    // Our resulting instantiation is actually a function template, since we
606    // are substituting only the outer template parameters. For example, given
607    //
608    //   template<typename T>
609    //   struct X {
610    //     template<typename U> void f(T, U);
611    //   };
612    //
613    //   X<int> x;
614    //
615    // We are instantiating the member template "f" within X<int>, which means
616    // substituting int for T, but leaving "f" as a member function template.
617    // Build the function template itself.
618    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
619                                                    Method->getLocation(),
620                                                    Method->getDeclName(),
621                                                    TemplateParams, Method);
622    if (D->isOutOfLine())
623      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
624    Method->setDescribedFunctionTemplate(FunctionTemplate);
625  } else if (!FunctionTemplate)
626    Method->setInstantiationOfMemberFunction(D);
627
628  // If we are instantiating a member function defined
629  // out-of-line, the instantiation will have the same lexical
630  // context (which will be a namespace scope) as the template.
631  if (D->isOutOfLine())
632    Method->setLexicalDeclContext(D->getLexicalDeclContext());
633
634  // Attach the parameters
635  for (unsigned P = 0; P < Params.size(); ++P)
636    Params[P]->setOwningFunction(Method);
637  Method->setParams(SemaRef.Context, Params.data(), Params.size());
638
639  if (InitMethodInstantiation(Method, D))
640    Method->setInvalidDecl();
641
642  NamedDecl *PrevDecl = 0;
643
644  if (!FunctionTemplate || TemplateParams) {
645    PrevDecl = SemaRef.LookupQualifiedName(Owner, Name,
646                                           Sema::LookupOrdinaryName, true);
647
648    // In C++, the previous declaration we find might be a tag type
649    // (class or enum). In this case, the new declaration will hide the
650    // tag type. Note that this does does not apply if we're declaring a
651    // typedef (C++ [dcl.typedef]p4).
652    if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag)
653      PrevDecl = 0;
654  }
655
656  if (FunctionTemplate && !TemplateParams)
657    // Record this function template specialization.
658    Method->setFunctionTemplateSpecialization(SemaRef.Context,
659                                              FunctionTemplate,
660                                              &TemplateArgs.getInnermost(),
661                                              InsertPos);
662
663  bool Redeclaration = false;
664  bool OverloadableAttrRequired = false;
665  SemaRef.CheckFunctionDeclaration(Method, PrevDecl, Redeclaration,
666                                   /*FIXME:*/OverloadableAttrRequired);
667
668  if (!FunctionTemplate && (!Method->isInvalidDecl() || !PrevDecl))
669    Owner->addDecl(Method);
670
671  return Method;
672}
673
674Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
675  return VisitCXXMethodDecl(D);
676}
677
678Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
679  return VisitCXXMethodDecl(D);
680}
681
682Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
683  return VisitCXXMethodDecl(D);
684}
685
686ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
687  QualType OrigT = SemaRef.SubstType(D->getOriginalType(), TemplateArgs,
688                                           D->getLocation(), D->getDeclName());
689  if (OrigT.isNull())
690    return 0;
691
692  QualType T = SemaRef.adjustParameterType(OrigT);
693
694  // Allocate the parameter
695  ParmVarDecl *Param = 0;
696  if (T == OrigT)
697    Param = ParmVarDecl::Create(SemaRef.Context, Owner, D->getLocation(),
698                                D->getIdentifier(), T, D->getDeclaratorInfo(),
699                                D->getStorageClass(), 0);
700  else
701    Param = OriginalParmVarDecl::Create(SemaRef.Context, Owner,
702                                        D->getLocation(), D->getIdentifier(),
703                                        T, D->getDeclaratorInfo(), OrigT,
704                                        D->getStorageClass(), 0);
705
706  // Mark the default argument as being uninstantiated.
707  if (Expr *Arg = D->getDefaultArg())
708    Param->setUninstantiatedDefaultArg(Arg);
709
710  // Note: we don't try to instantiate function parameters until after
711  // we've instantiated the function's type. Therefore, we don't have
712  // to check for 'void' parameter types here.
713  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
714  return Param;
715}
716
717Decl *
718TemplateDeclInstantiator::VisitOriginalParmVarDecl(OriginalParmVarDecl *D) {
719  // Since parameter types can decay either before or after
720  // instantiation, we simply treat OriginalParmVarDecls as
721  // ParmVarDecls the same way, and create one or the other depending
722  // on what happens after template instantiation.
723  return VisitParmVarDecl(D);
724}
725
726Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
727                                                    TemplateTypeParmDecl *D) {
728  // TODO: don't always clone when decls are refcounted.
729  const Type* T = D->getTypeForDecl();
730  assert(T->isTemplateTypeParmType());
731  const TemplateTypeParmType *TTPT = T->getAs<TemplateTypeParmType>();
732
733  TemplateTypeParmDecl *Inst =
734    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
735                                 TTPT->getDepth(), TTPT->getIndex(),
736                                 TTPT->getName(),
737                                 D->wasDeclaredWithTypename(),
738                                 D->isParameterPack());
739
740  if (D->hasDefaultArgument()) {
741    QualType DefaultPattern = D->getDefaultArgument();
742    QualType DefaultInst
743      = SemaRef.SubstType(DefaultPattern, TemplateArgs,
744                          D->getDefaultArgumentLoc(),
745                          D->getDeclName());
746
747    Inst->setDefaultArgument(DefaultInst,
748                             D->getDefaultArgumentLoc(),
749                             D->defaultArgumentWasInherited() /* preserve? */);
750  }
751
752  return Inst;
753}
754
755Decl *
756TemplateDeclInstantiator::VisitUnresolvedUsingDecl(UnresolvedUsingDecl *D) {
757  NestedNameSpecifier *NNS =
758    SemaRef.SubstNestedNameSpecifier(D->getTargetNestedNameSpecifier(),
759                                     D->getTargetNestedNameRange(),
760                                     TemplateArgs);
761  if (!NNS)
762    return 0;
763
764  CXXScopeSpec SS;
765  SS.setRange(D->getTargetNestedNameRange());
766  SS.setScopeRep(NNS);
767
768  NamedDecl *UD =
769    SemaRef.BuildUsingDeclaration(D->getLocation(), SS,
770                                  D->getTargetNameLocation(),
771                                  D->getTargetName(), 0, D->isTypeName());
772  if (UD)
773    SemaRef.Context.setInstantiatedFromUnresolvedUsingDecl(cast<UsingDecl>(UD),
774                                                           D);
775  return UD;
776}
777
778Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
779                      const MultiLevelTemplateArgumentList &TemplateArgs) {
780  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
781  return Instantiator.Visit(D);
782}
783
784/// \brief Instantiates a nested template parameter list in the current
785/// instantiation context.
786///
787/// \param L The parameter list to instantiate
788///
789/// \returns NULL if there was an error
790TemplateParameterList *
791TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
792  // Get errors for all the parameters before bailing out.
793  bool Invalid = false;
794
795  unsigned N = L->size();
796  typedef llvm::SmallVector<Decl*,8> ParamVector;
797  ParamVector Params;
798  Params.reserve(N);
799  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end();
800       PI != PE; ++PI) {
801    Decl *D = Visit(*PI);
802    Params.push_back(D);
803    Invalid = Invalid || !D;
804  }
805
806  // Clean up if we had an error.
807  if (Invalid) {
808    for (ParamVector::iterator PI = Params.begin(), PE = Params.end();
809         PI != PE; ++PI)
810      if (*PI)
811        (*PI)->Destroy(SemaRef.Context);
812    return NULL;
813  }
814
815  TemplateParameterList *InstL
816    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
817                                    L->getLAngleLoc(), &Params.front(), N,
818                                    L->getRAngleLoc());
819  return InstL;
820}
821
822/// \brief Does substitution on the type of the given function, including
823/// all of the function parameters.
824///
825/// \param D The function whose type will be the basis of the substitution
826///
827/// \param Params the instantiated parameter declarations
828
829/// \returns the instantiated function's type if successful, a NULL
830/// type if there was an error.
831QualType
832TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
833                              llvm::SmallVectorImpl<ParmVarDecl *> &Params) {
834  bool InvalidDecl = false;
835
836  // Substitute all of the function's formal parameter types.
837  TemplateDeclInstantiator ParamInstantiator(SemaRef, 0, TemplateArgs);
838  llvm::SmallVector<QualType, 4> ParamTys;
839  for (FunctionDecl::param_iterator P = D->param_begin(),
840                                 PEnd = D->param_end();
841       P != PEnd; ++P) {
842    if (ParmVarDecl *PInst = ParamInstantiator.VisitParmVarDecl(*P)) {
843      if (PInst->getType()->isVoidType()) {
844        SemaRef.Diag(PInst->getLocation(), diag::err_param_with_void_type);
845        PInst->setInvalidDecl();
846      } else if (SemaRef.RequireNonAbstractType(PInst->getLocation(),
847                                                PInst->getType(),
848                                                diag::err_abstract_type_in_decl,
849                                                Sema::AbstractParamType))
850        PInst->setInvalidDecl();
851
852      Params.push_back(PInst);
853      ParamTys.push_back(PInst->getType());
854
855      if (PInst->isInvalidDecl())
856        InvalidDecl = true;
857    } else
858      InvalidDecl = true;
859  }
860
861  // FIXME: Deallocate dead declarations.
862  if (InvalidDecl)
863    return QualType();
864
865  const FunctionProtoType *Proto = D->getType()->getAsFunctionProtoType();
866  assert(Proto && "Missing prototype?");
867  QualType ResultType
868    = SemaRef.SubstType(Proto->getResultType(), TemplateArgs,
869                        D->getLocation(), D->getDeclName());
870  if (ResultType.isNull())
871    return QualType();
872
873  return SemaRef.BuildFunctionType(ResultType, ParamTys.data(), ParamTys.size(),
874                                   Proto->isVariadic(), Proto->getTypeQuals(),
875                                   D->getLocation(), D->getDeclName());
876}
877
878/// \brief Initializes the common fields of an instantiation function
879/// declaration (New) from the corresponding fields of its template (Tmpl).
880///
881/// \returns true if there was an error
882bool
883TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
884                                                    FunctionDecl *Tmpl) {
885  if (Tmpl->isDeleted())
886    New->setDeleted();
887
888  // If we are performing substituting explicitly-specified template arguments
889  // or deduced template arguments into a function template and we reach this
890  // point, we are now past the point where SFINAE applies and have committed
891  // to keeping the new function template specialization. We therefore
892  // convert the active template instantiation for the function template
893  // into a template instantiation for this specific function template
894  // specialization, which is not a SFINAE context, so that we diagnose any
895  // further errors in the declaration itself.
896  typedef Sema::ActiveTemplateInstantiation ActiveInstType;
897  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back();
898  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
899      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
900    if (FunctionTemplateDecl *FunTmpl
901          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) {
902      assert(FunTmpl->getTemplatedDecl() == Tmpl &&
903             "Deduction from the wrong function template?");
904      (void) FunTmpl;
905      ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
906      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New);
907    }
908  }
909
910  return false;
911}
912
913/// \brief Initializes common fields of an instantiated method
914/// declaration (New) from the corresponding fields of its template
915/// (Tmpl).
916///
917/// \returns true if there was an error
918bool
919TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
920                                                  CXXMethodDecl *Tmpl) {
921  if (InitFunctionInstantiation(New, Tmpl))
922    return true;
923
924  CXXRecordDecl *Record = cast<CXXRecordDecl>(Owner);
925  New->setAccess(Tmpl->getAccess());
926  if (Tmpl->isVirtualAsWritten()) {
927    New->setVirtualAsWritten(true);
928    Record->setAggregate(false);
929    Record->setPOD(false);
930    Record->setEmpty(false);
931    Record->setPolymorphic(true);
932  }
933  if (Tmpl->isPure()) {
934    New->setPure();
935    Record->setAbstract(true);
936  }
937
938  // FIXME: attributes
939  // FIXME: New needs a pointer to Tmpl
940  return false;
941}
942
943/// \brief Instantiate the definition of the given function from its
944/// template.
945///
946/// \param PointOfInstantiation the point at which the instantiation was
947/// required. Note that this is not precisely a "point of instantiation"
948/// for the function, but it's close.
949///
950/// \param Function the already-instantiated declaration of a
951/// function template specialization or member function of a class template
952/// specialization.
953///
954/// \param Recursive if true, recursively instantiates any functions that
955/// are required by this instantiation.
956void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
957                                         FunctionDecl *Function,
958                                         bool Recursive) {
959  if (Function->isInvalidDecl())
960    return;
961
962  assert(!Function->getBody() && "Already instantiated!");
963
964  // Find the function body that we'll be substituting.
965  const FunctionDecl *PatternDecl = 0;
966  if (FunctionTemplateDecl *Primary = Function->getPrimaryTemplate()) {
967    while (Primary->getInstantiatedFromMemberTemplate())
968      Primary = Primary->getInstantiatedFromMemberTemplate();
969
970    PatternDecl = Primary->getTemplatedDecl();
971  } else
972    PatternDecl = Function->getInstantiatedFromMemberFunction();
973  Stmt *Pattern = 0;
974  if (PatternDecl)
975    Pattern = PatternDecl->getBody(PatternDecl);
976
977  if (!Pattern)
978    return;
979
980  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
981  if (Inst)
982    return;
983
984  // If we're performing recursive template instantiation, create our own
985  // queue of pending implicit instantiations that we will instantiate later,
986  // while we're still within our own instantiation context.
987  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
988  if (Recursive)
989    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
990
991  ActOnStartOfFunctionDef(0, DeclPtrTy::make(Function));
992
993  // Introduce a new scope where local variable instantiations will be
994  // recorded.
995  LocalInstantiationScope Scope(*this);
996
997  // Introduce the instantiated function parameters into the local
998  // instantiation scope.
999  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I)
1000    Scope.InstantiatedLocal(PatternDecl->getParamDecl(I),
1001                            Function->getParamDecl(I));
1002
1003  // Enter the scope of this instantiation. We don't use
1004  // PushDeclContext because we don't have a scope.
1005  DeclContext *PreviousContext = CurContext;
1006  CurContext = Function;
1007
1008  MultiLevelTemplateArgumentList TemplateArgs =
1009    getTemplateInstantiationArgs(Function);
1010
1011  // If this is a constructor, instantiate the member initializers.
1012  if (const CXXConstructorDecl *Ctor =
1013        dyn_cast<CXXConstructorDecl>(PatternDecl)) {
1014    InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor,
1015                               TemplateArgs);
1016  }
1017
1018  // Instantiate the function body.
1019  OwningStmtResult Body = SubstStmt(Pattern, TemplateArgs);
1020
1021  ActOnFinishFunctionBody(DeclPtrTy::make(Function), move(Body),
1022                          /*IsInstantiation=*/true);
1023
1024  CurContext = PreviousContext;
1025
1026  DeclGroupRef DG(Function);
1027  Consumer.HandleTopLevelDecl(DG);
1028
1029  if (Recursive) {
1030    // Instantiate any pending implicit instantiations found during the
1031    // instantiation of this template.
1032    PerformPendingImplicitInstantiations();
1033
1034    // Restore the set of pending implicit instantiations.
1035    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1036  }
1037}
1038
1039/// \brief Instantiate the definition of the given variable from its
1040/// template.
1041///
1042/// \param PointOfInstantiation the point at which the instantiation was
1043/// required. Note that this is not precisely a "point of instantiation"
1044/// for the function, but it's close.
1045///
1046/// \param Var the already-instantiated declaration of a static member
1047/// variable of a class template specialization.
1048///
1049/// \param Recursive if true, recursively instantiates any functions that
1050/// are required by this instantiation.
1051void Sema::InstantiateStaticDataMemberDefinition(
1052                                          SourceLocation PointOfInstantiation,
1053                                                 VarDecl *Var,
1054                                                 bool Recursive) {
1055  if (Var->isInvalidDecl())
1056    return;
1057
1058  // Find the out-of-line definition of this static data member.
1059  // FIXME: Do we have to look for specializations separately?
1060  VarDecl *Def = Var->getInstantiatedFromStaticDataMember();
1061  bool FoundOutOfLineDef = false;
1062  assert(Def && "This data member was not instantiated from a template?");
1063  assert(Def->isStaticDataMember() && "Not a static data member?");
1064  for (VarDecl::redecl_iterator RD = Def->redecls_begin(),
1065                             RDEnd = Def->redecls_end();
1066       RD != RDEnd; ++RD) {
1067    if (RD->getLexicalDeclContext()->isFileContext()) {
1068      Def = *RD;
1069      FoundOutOfLineDef = true;
1070    }
1071  }
1072
1073  if (!FoundOutOfLineDef) {
1074    // We did not find an out-of-line definition of this static data member,
1075    // so we won't perform any instantiation. Rather, we rely on the user to
1076    // instantiate this definition (or provide a specialization for it) in
1077    // another translation unit.
1078    return;
1079  }
1080
1081  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
1082  if (Inst)
1083    return;
1084
1085  // If we're performing recursive template instantiation, create our own
1086  // queue of pending implicit instantiations that we will instantiate later,
1087  // while we're still within our own instantiation context.
1088  std::deque<PendingImplicitInstantiation> SavedPendingImplicitInstantiations;
1089  if (Recursive)
1090    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1091
1092  // Enter the scope of this instantiation. We don't use
1093  // PushDeclContext because we don't have a scope.
1094  DeclContext *PreviousContext = CurContext;
1095  CurContext = Var->getDeclContext();
1096
1097  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
1098                                          getTemplateInstantiationArgs(Var)));
1099
1100  CurContext = PreviousContext;
1101
1102  if (Var) {
1103    DeclGroupRef DG(Var);
1104    Consumer.HandleTopLevelDecl(DG);
1105  }
1106
1107  if (Recursive) {
1108    // Instantiate any pending implicit instantiations found during the
1109    // instantiation of this template.
1110    PerformPendingImplicitInstantiations();
1111
1112    // Restore the set of pending implicit instantiations.
1113    PendingImplicitInstantiations.swap(SavedPendingImplicitInstantiations);
1114  }
1115}
1116
1117void
1118Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
1119                                 const CXXConstructorDecl *Tmpl,
1120                           const MultiLevelTemplateArgumentList &TemplateArgs) {
1121
1122  llvm::SmallVector<MemInitTy*, 4> NewInits;
1123
1124  // Instantiate all the initializers.
1125  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(),
1126                                            InitsEnd = Tmpl->init_end();
1127       Inits != InitsEnd; ++Inits) {
1128    CXXBaseOrMemberInitializer *Init = *Inits;
1129
1130    ASTOwningVector<&ActionBase::DeleteExpr> NewArgs(*this);
1131
1132    // Instantiate all the arguments.
1133    for (ExprIterator Args = Init->arg_begin(), ArgsEnd = Init->arg_end();
1134         Args != ArgsEnd; ++Args) {
1135      OwningExprResult NewArg = SubstExpr(*Args, TemplateArgs);
1136
1137      if (NewArg.isInvalid())
1138        New->setInvalidDecl();
1139      else
1140        NewArgs.push_back(NewArg.takeAs<Expr>());
1141    }
1142
1143    MemInitResult NewInit;
1144
1145    if (Init->isBaseInitializer()) {
1146      QualType BaseType(Init->getBaseClass(), 0);
1147      BaseType = SubstType(BaseType, TemplateArgs, Init->getSourceLocation(),
1148                           New->getDeclName());
1149
1150      NewInit = BuildBaseInitializer(BaseType,
1151                                     (Expr **)NewArgs.data(),
1152                                     NewArgs.size(),
1153                                     Init->getSourceLocation(),
1154                                     Init->getRParenLoc(),
1155                                     New->getParent());
1156    } else if (Init->isMemberInitializer()) {
1157      FieldDecl *Member;
1158
1159      // Is this an anonymous union?
1160      if (FieldDecl *UnionInit = Init->getAnonUnionMember())
1161        Member = cast<FieldDecl>(FindInstantiatedDecl(UnionInit));
1162      else
1163        Member = cast<FieldDecl>(FindInstantiatedDecl(Init->getMember()));
1164
1165      NewInit = BuildMemberInitializer(Member, (Expr **)NewArgs.data(),
1166                                       NewArgs.size(),
1167                                       Init->getSourceLocation(),
1168                                       Init->getRParenLoc());
1169    }
1170
1171    if (NewInit.isInvalid())
1172      New->setInvalidDecl();
1173    else {
1174      // FIXME: It would be nice if ASTOwningVector had a release function.
1175      NewArgs.take();
1176
1177      NewInits.push_back((MemInitTy *)NewInit.get());
1178    }
1179  }
1180
1181  // Assign all the initializers to the new constructor.
1182  ActOnMemInitializers(DeclPtrTy::make(New),
1183                       /*FIXME: ColonLoc */
1184                       SourceLocation(),
1185                       NewInits.data(), NewInits.size());
1186}
1187
1188// TODO: this could be templated if the various decl types used the
1189// same method name.
1190static bool isInstantiationOf(ClassTemplateDecl *Pattern,
1191                              ClassTemplateDecl *Instance) {
1192  Pattern = Pattern->getCanonicalDecl();
1193
1194  do {
1195    Instance = Instance->getCanonicalDecl();
1196    if (Pattern == Instance) return true;
1197    Instance = Instance->getInstantiatedFromMemberTemplate();
1198  } while (Instance);
1199
1200  return false;
1201}
1202
1203static bool isInstantiationOf(CXXRecordDecl *Pattern,
1204                              CXXRecordDecl *Instance) {
1205  Pattern = Pattern->getCanonicalDecl();
1206
1207  do {
1208    Instance = Instance->getCanonicalDecl();
1209    if (Pattern == Instance) return true;
1210    Instance = Instance->getInstantiatedFromMemberClass();
1211  } while (Instance);
1212
1213  return false;
1214}
1215
1216static bool isInstantiationOf(FunctionDecl *Pattern,
1217                              FunctionDecl *Instance) {
1218  Pattern = Pattern->getCanonicalDecl();
1219
1220  do {
1221    Instance = Instance->getCanonicalDecl();
1222    if (Pattern == Instance) return true;
1223    Instance = Instance->getInstantiatedFromMemberFunction();
1224  } while (Instance);
1225
1226  return false;
1227}
1228
1229static bool isInstantiationOf(EnumDecl *Pattern,
1230                              EnumDecl *Instance) {
1231  Pattern = Pattern->getCanonicalDecl();
1232
1233  do {
1234    Instance = Instance->getCanonicalDecl();
1235    if (Pattern == Instance) return true;
1236    Instance = Instance->getInstantiatedFromMemberEnum();
1237  } while (Instance);
1238
1239  return false;
1240}
1241
1242static bool isInstantiationOf(UnresolvedUsingDecl *Pattern,
1243                              UsingDecl *Instance,
1244                              ASTContext &C) {
1245  return C.getInstantiatedFromUnresolvedUsingDecl(Instance) == Pattern;
1246}
1247
1248static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
1249                                              VarDecl *Instance) {
1250  assert(Instance->isStaticDataMember());
1251
1252  Pattern = Pattern->getCanonicalDecl();
1253
1254  do {
1255    Instance = Instance->getCanonicalDecl();
1256    if (Pattern == Instance) return true;
1257    Instance = Instance->getInstantiatedFromStaticDataMember();
1258  } while (Instance);
1259
1260  return false;
1261}
1262
1263static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
1264  if (D->getKind() != Other->getKind()) {
1265    if (UnresolvedUsingDecl *UUD = dyn_cast<UnresolvedUsingDecl>(D)) {
1266      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
1267        return isInstantiationOf(UUD, UD, Ctx);
1268      }
1269    }
1270
1271    return false;
1272  }
1273
1274  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
1275    return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
1276
1277  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other))
1278    return isInstantiationOf(cast<FunctionDecl>(D), Function);
1279
1280  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other))
1281    return isInstantiationOf(cast<EnumDecl>(D), Enum);
1282
1283  if (VarDecl *Var = dyn_cast<VarDecl>(Other))
1284    if (Var->isStaticDataMember())
1285      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
1286
1287  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other))
1288    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
1289
1290  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) {
1291    if (!Field->getDeclName()) {
1292      // This is an unnamed field.
1293      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) ==
1294        cast<FieldDecl>(D);
1295    }
1296  }
1297
1298  return D->getDeclName() && isa<NamedDecl>(Other) &&
1299    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
1300}
1301
1302template<typename ForwardIterator>
1303static NamedDecl *findInstantiationOf(ASTContext &Ctx,
1304                                      NamedDecl *D,
1305                                      ForwardIterator first,
1306                                      ForwardIterator last) {
1307  for (; first != last; ++first)
1308    if (isInstantiationOf(Ctx, D, *first))
1309      return cast<NamedDecl>(*first);
1310
1311  return 0;
1312}
1313
1314/// \brief Finds the instantiation of the given declaration context
1315/// within the current instantiation.
1316///
1317/// \returns NULL if there was an error
1318DeclContext *Sema::FindInstantiatedContext(DeclContext* DC) {
1319  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
1320    Decl* ID = FindInstantiatedDecl(D);
1321    return cast_or_null<DeclContext>(ID);
1322  } else return DC;
1323}
1324
1325/// \brief Find the instantiation of the given declaration within the
1326/// current instantiation.
1327///
1328/// This routine is intended to be used when \p D is a declaration
1329/// referenced from within a template, that needs to mapped into the
1330/// corresponding declaration within an instantiation. For example,
1331/// given:
1332///
1333/// \code
1334/// template<typename T>
1335/// struct X {
1336///   enum Kind {
1337///     KnownValue = sizeof(T)
1338///   };
1339///
1340///   bool getKind() const { return KnownValue; }
1341/// };
1342///
1343/// template struct X<int>;
1344/// \endcode
1345///
1346/// In the instantiation of X<int>::getKind(), we need to map the
1347/// EnumConstantDecl for KnownValue (which refers to
1348/// X<T>::<Kind>::KnownValue) to its instantiation
1349/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs
1350/// this mapping from within the instantiation of X<int>.
1351NamedDecl *Sema::FindInstantiatedDecl(NamedDecl *D) {
1352  if (OverloadedFunctionDecl *Ovl = dyn_cast<OverloadedFunctionDecl>(D)) {
1353    // Transform all of the elements of the overloaded function set.
1354    OverloadedFunctionDecl *Result
1355      = OverloadedFunctionDecl::Create(Context, CurContext, Ovl->getDeclName());
1356
1357    for (OverloadedFunctionDecl::function_iterator F = Ovl->function_begin(),
1358                                                FEnd = Ovl->function_end();
1359         F != FEnd; ++F) {
1360      Result->addOverload(
1361                  AnyFunctionDecl::getFromNamedDecl(FindInstantiatedDecl(*F)));
1362    }
1363
1364    return Result;
1365  }
1366
1367  DeclContext *ParentDC = D->getDeclContext();
1368  if (isa<ParmVarDecl>(D) || ParentDC->isFunctionOrMethod()) {
1369    // D is a local of some kind. Look into the map of local
1370    // declarations to their instantiations.
1371    return cast<NamedDecl>(CurrentInstantiationScope->getInstantiationOf(D));
1372  }
1373
1374  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D))
1375    if (ClassTemplateDecl *ClassTemplate
1376          = Record->getDescribedClassTemplate()) {
1377      // When the declaration D was parsed, it referred to the current
1378      // instantiation. Therefore, look through the current context,
1379      // which contains actual instantiations, to find the
1380      // instantiation of the "current instantiation" that D refers
1381      // to. Alternatively, we could just instantiate the
1382      // injected-class-name with the current template arguments, but
1383      // such an instantiation is far more expensive.
1384      for (DeclContext *DC = CurContext; !DC->isFileContext();
1385           DC = DC->getParent()) {
1386        if (ClassTemplateSpecializationDecl *Spec
1387              = dyn_cast<ClassTemplateSpecializationDecl>(DC))
1388          if (isInstantiationOf(ClassTemplate, Spec->getSpecializedTemplate()))
1389            return Spec;
1390      }
1391
1392      assert(false &&
1393             "Unable to find declaration for the current instantiation");
1394    }
1395
1396  ParentDC = FindInstantiatedContext(ParentDC);
1397  if (!ParentDC)
1398    return 0;
1399
1400  if (ParentDC != D->getDeclContext()) {
1401    // We performed some kind of instantiation in the parent context,
1402    // so now we need to look into the instantiated parent context to
1403    // find the instantiation of the declaration D.
1404    NamedDecl *Result = 0;
1405    if (D->getDeclName()) {
1406      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName());
1407      Result = findInstantiationOf(Context, D, Found.first, Found.second);
1408    } else {
1409      // Since we don't have a name for the entity we're looking for,
1410      // our only option is to walk through all of the declarations to
1411      // find that name. This will occur in a few cases:
1412      //
1413      //   - anonymous struct/union within a template
1414      //   - unnamed class/struct/union/enum within a template
1415      //
1416      // FIXME: Find a better way to find these instantiations!
1417      Result = findInstantiationOf(Context, D,
1418                                   ParentDC->decls_begin(),
1419                                   ParentDC->decls_end());
1420    }
1421
1422    assert(Result && "Unable to find instantiation of declaration!");
1423    D = Result;
1424  }
1425
1426  return D;
1427}
1428
1429/// \brief Performs template instantiation for all implicit template
1430/// instantiations we have seen until this point.
1431void Sema::PerformPendingImplicitInstantiations() {
1432  while (!PendingImplicitInstantiations.empty()) {
1433    PendingImplicitInstantiation Inst = PendingImplicitInstantiations.front();
1434    PendingImplicitInstantiations.pop_front();
1435
1436    // Instantiate function definitions
1437    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
1438      PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Function),
1439                                            Function->getLocation(), *this,
1440                                            Context.getSourceManager(),
1441                                           "instantiating function definition");
1442
1443      if (!Function->getBody())
1444        InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true);
1445      continue;
1446    }
1447
1448    // Instantiate static data member definitions.
1449    VarDecl *Var = cast<VarDecl>(Inst.first);
1450    assert(Var->isStaticDataMember() && "Not a static data member?");
1451
1452    PrettyStackTraceActionsDecl CrashInfo(DeclPtrTy::make(Var),
1453                                          Var->getLocation(), *this,
1454                                          Context.getSourceManager(),
1455                                          "instantiating static data member "
1456                                          "definition");
1457
1458    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true);
1459  }
1460}
1461