DeclBase.cpp revision 5586b019c18024b2967d027a17d5a05584a8b181 
1//===--- DeclBase.cpp - Declaration AST Node Implementation ---------------===//
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//
10// This file implements the Decl and DeclContext classes.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/AST/DeclBase.h"
15#include "clang/AST/Decl.h"
16#include "clang/AST/DeclContextInternals.h"
17#include "clang/AST/DeclCXX.h"
18#include "clang/AST/DeclFriend.h"
19#include "clang/AST/DeclObjC.h"
20#include "clang/AST/DeclTemplate.h"
21#include "clang/AST/DependentDiagnostic.h"
22#include "clang/AST/ExternalASTSource.h"
23#include "clang/AST/ASTContext.h"
24#include "clang/AST/Type.h"
25#include "clang/AST/Stmt.h"
26#include "clang/AST/StmtCXX.h"
27#include "llvm/ADT/DenseMap.h"
28#include "llvm/Support/raw_ostream.h"
29#include <algorithm>
30#include <cstdio>
31#include <vector>
32using namespace clang;
33
34//===----------------------------------------------------------------------===//
35//  Statistics
36//===----------------------------------------------------------------------===//
37
38#define DECL(DERIVED, BASE) static int n##DERIVED##s = 0;
39#define ABSTRACT_DECL(DECL)
40#include "clang/AST/DeclNodes.inc"
41
42static bool StatSwitch = false;
43
44const char *Decl::getDeclKindName() const {
45  switch (DeclKind) {
46  default: assert(0 && "Declaration not in DeclNodes.inc!");
47#define DECL(DERIVED, BASE) case DERIVED: return #DERIVED;
48#define ABSTRACT_DECL(DECL)
49#include "clang/AST/DeclNodes.inc"
50  }
51}
52
53void Decl::setInvalidDecl(bool Invalid) {
54  InvalidDecl = Invalid;
55  if (Invalid) {
56    // Defensive maneuver for ill-formed code: we're likely not to make it to
57    // a point where we set the access specifier, so default it to "public"
58    // to avoid triggering asserts elsewhere in the front end.
59    setAccess(AS_public);
60  }
61}
62
63const char *DeclContext::getDeclKindName() const {
64  switch (DeclKind) {
65  default: assert(0 && "Declaration context not in DeclNodes.inc!");
66#define DECL(DERIVED, BASE) case Decl::DERIVED: return #DERIVED;
67#define ABSTRACT_DECL(DECL)
68#include "clang/AST/DeclNodes.inc"
69  }
70}
71
72bool Decl::CollectingStats(bool Enable) {
73  if (Enable) StatSwitch = true;
74  return StatSwitch;
75}
76
77void Decl::PrintStats() {
78  fprintf(stderr, "*** Decl Stats:\n");
79
80  int totalDecls = 0;
81#define DECL(DERIVED, BASE) totalDecls += n##DERIVED##s;
82#define ABSTRACT_DECL(DECL)
83#include "clang/AST/DeclNodes.inc"
84  fprintf(stderr, "  %d decls total.\n", totalDecls);
85
86  int totalBytes = 0;
87#define DECL(DERIVED, BASE)                                             \
88  if (n##DERIVED##s > 0) {                                              \
89    totalBytes += (int)(n##DERIVED##s * sizeof(DERIVED##Decl));         \
90    fprintf(stderr, "    %d " #DERIVED " decls, %d each (%d bytes)\n",  \
91            n##DERIVED##s, (int)sizeof(DERIVED##Decl),                  \
92            (int)(n##DERIVED##s * sizeof(DERIVED##Decl)));              \
93  }
94#define ABSTRACT_DECL(DECL)
95#include "clang/AST/DeclNodes.inc"
96
97  fprintf(stderr, "Total bytes = %d\n", totalBytes);
98}
99
100void Decl::add(Kind k) {
101  switch (k) {
102  default: assert(0 && "Declaration not in DeclNodes.inc!");
103#define DECL(DERIVED, BASE) case DERIVED: ++n##DERIVED##s; break;
104#define ABSTRACT_DECL(DECL)
105#include "clang/AST/DeclNodes.inc"
106  }
107}
108
109bool Decl::isTemplateParameterPack() const {
110  if (const TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(this))
111    return TTP->isParameterPack();
112
113  return false;
114}
115
116bool Decl::isFunctionOrFunctionTemplate() const {
117  if (const UsingShadowDecl *UD = dyn_cast<UsingShadowDecl>(this))
118    return UD->getTargetDecl()->isFunctionOrFunctionTemplate();
119
120  return isa<FunctionDecl>(this) || isa<FunctionTemplateDecl>(this);
121}
122
123bool Decl::isDefinedOutsideFunctionOrMethod() const {
124  for (const DeclContext *DC = getDeclContext();
125       DC && !DC->isTranslationUnit();
126       DC = DC->getParent())
127    if (DC->isFunctionOrMethod())
128      return false;
129
130  return true;
131}
132
133
134//===----------------------------------------------------------------------===//
135// PrettyStackTraceDecl Implementation
136//===----------------------------------------------------------------------===//
137
138void PrettyStackTraceDecl::print(llvm::raw_ostream &OS) const {
139  SourceLocation TheLoc = Loc;
140  if (TheLoc.isInvalid() && TheDecl)
141    TheLoc = TheDecl->getLocation();
142
143  if (TheLoc.isValid()) {
144    TheLoc.print(OS, SM);
145    OS << ": ";
146  }
147
148  OS << Message;
149
150  if (const NamedDecl *DN = dyn_cast_or_null<NamedDecl>(TheDecl))
151    OS << " '" << DN->getQualifiedNameAsString() << '\'';
152  OS << '\n';
153}
154
155//===----------------------------------------------------------------------===//
156// Decl Implementation
157//===----------------------------------------------------------------------===//
158
159// Out-of-line virtual method providing a home for Decl.
160Decl::~Decl() {
161  assert(!HasAttrs && "attributes should have been freed by Destroy");
162}
163
164void Decl::setDeclContext(DeclContext *DC) {
165  if (isOutOfSemaDC())
166    delete getMultipleDC();
167
168  DeclCtx = DC;
169}
170
171void Decl::setLexicalDeclContext(DeclContext *DC) {
172  if (DC == getLexicalDeclContext())
173    return;
174
175  if (isInSemaDC()) {
176    MultipleDC *MDC = new (getASTContext()) MultipleDC();
177    MDC->SemanticDC = getDeclContext();
178    MDC->LexicalDC = DC;
179    DeclCtx = MDC;
180  } else {
181    getMultipleDC()->LexicalDC = DC;
182  }
183}
184
185bool Decl::isInAnonymousNamespace() const {
186  const DeclContext *DC = getDeclContext();
187  do {
188    if (const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(DC))
189      if (ND->isAnonymousNamespace())
190        return true;
191  } while ((DC = DC->getParent()));
192
193  return false;
194}
195
196TranslationUnitDecl *Decl::getTranslationUnitDecl() {
197  if (TranslationUnitDecl *TUD = dyn_cast<TranslationUnitDecl>(this))
198    return TUD;
199
200  DeclContext *DC = getDeclContext();
201  assert(DC && "This decl is not contained in a translation unit!");
202
203  while (!DC->isTranslationUnit()) {
204    DC = DC->getParent();
205    assert(DC && "This decl is not contained in a translation unit!");
206  }
207
208  return cast<TranslationUnitDecl>(DC);
209}
210
211ASTContext &Decl::getASTContext() const {
212  return getTranslationUnitDecl()->getASTContext();
213}
214
215bool Decl::isUsed(bool CheckUsedAttr) const {
216  if (Used)
217    return true;
218
219  // Check for used attribute.
220  if (CheckUsedAttr && hasAttr<UsedAttr>())
221    return true;
222
223  // Check redeclarations for used attribute.
224  for (redecl_iterator I = redecls_begin(), E = redecls_end(); I != E; ++I) {
225    if ((CheckUsedAttr && I->hasAttr<UsedAttr>()) || I->Used)
226      return true;
227  }
228
229  return false;
230}
231
232
233unsigned Decl::getIdentifierNamespaceForKind(Kind DeclKind) {
234  switch (DeclKind) {
235    case Function:
236    case CXXMethod:
237    case CXXConstructor:
238    case CXXDestructor:
239    case CXXConversion:
240    case EnumConstant:
241    case Var:
242    case ImplicitParam:
243    case ParmVar:
244    case NonTypeTemplateParm:
245    case ObjCMethod:
246    case ObjCProperty:
247      return IDNS_Ordinary;
248
249    case ObjCCompatibleAlias:
250    case ObjCInterface:
251      return IDNS_Ordinary | IDNS_Type;
252
253    case Typedef:
254    case UnresolvedUsingTypename:
255    case TemplateTypeParm:
256      return IDNS_Ordinary | IDNS_Type;
257
258    case UsingShadow:
259      return 0; // we'll actually overwrite this later
260
261    case UnresolvedUsingValue:
262      return IDNS_Ordinary | IDNS_Using;
263
264    case Using:
265      return IDNS_Using;
266
267    case ObjCProtocol:
268      return IDNS_ObjCProtocol;
269
270    case Field:
271    case ObjCAtDefsField:
272    case ObjCIvar:
273      return IDNS_Member;
274
275    case Record:
276    case CXXRecord:
277    case Enum:
278      return IDNS_Tag | IDNS_Type;
279
280    case Namespace:
281    case NamespaceAlias:
282      return IDNS_Namespace;
283
284    case FunctionTemplate:
285      return IDNS_Ordinary;
286
287    case ClassTemplate:
288    case TemplateTemplateParm:
289      return IDNS_Ordinary | IDNS_Tag | IDNS_Type;
290
291    // Never have names.
292    case Friend:
293    case FriendTemplate:
294    case AccessSpec:
295    case LinkageSpec:
296    case FileScopeAsm:
297    case StaticAssert:
298    case ObjCClass:
299    case ObjCPropertyImpl:
300    case ObjCForwardProtocol:
301    case Block:
302    case TranslationUnit:
303
304    case UsingDirective:
305    case ClassTemplateSpecialization:
306    case ClassTemplatePartialSpecialization:
307    case ObjCImplementation:
308    case ObjCCategory:
309    case ObjCCategoryImpl:
310      // Never looked up by name.
311      return 0;
312  }
313
314  return 0;
315}
316
317void Decl::initAttrs(Attr *attrs) {
318  assert(!HasAttrs && "Decl already contains attrs.");
319
320  Attr *&AttrBlank = getASTContext().getDeclAttrs(this);
321  assert(AttrBlank == 0 && "HasAttrs was wrong?");
322
323  AttrBlank = attrs;
324  HasAttrs = true;
325}
326
327void Decl::addAttr(Attr *NewAttr) {
328  Attr *&ExistingAttr = getASTContext().getDeclAttrs(this);
329
330  assert(NewAttr->getNext() == 0 && "Chain of attributes will be truncated!");
331  NewAttr->setNext(ExistingAttr);
332  ExistingAttr = NewAttr;
333
334  HasAttrs = true;
335}
336
337void Decl::invalidateAttrs() {
338  if (!HasAttrs) return;
339
340  HasAttrs = false;
341  getASTContext().eraseDeclAttrs(this);
342}
343
344const Attr *Decl::getAttrsImpl() const {
345  assert(HasAttrs && "getAttrs() should verify this!");
346  return getASTContext().getDeclAttrs(this);
347}
348
349void Decl::swapAttrs(Decl *RHS) {
350  bool HasLHSAttr = this->HasAttrs;
351  bool HasRHSAttr = RHS->HasAttrs;
352
353  // Usually, neither decl has attrs, nothing to do.
354  if (!HasLHSAttr && !HasRHSAttr) return;
355
356  // If 'this' has no attrs, swap the other way.
357  if (!HasLHSAttr)
358    return RHS->swapAttrs(this);
359
360  ASTContext &Context = getASTContext();
361
362  // Handle the case when both decls have attrs.
363  if (HasRHSAttr) {
364    std::swap(Context.getDeclAttrs(this), Context.getDeclAttrs(RHS));
365    return;
366  }
367
368  // Otherwise, LHS has an attr and RHS doesn't.
369  Context.getDeclAttrs(RHS) = Context.getDeclAttrs(this);
370  Context.eraseDeclAttrs(this);
371  this->HasAttrs = false;
372  RHS->HasAttrs = true;
373}
374
375
376void Decl::Destroy(ASTContext &C) {
377  // Free attributes for this decl.
378  if (HasAttrs) {
379    C.getDeclAttrs(this)->Destroy(C);
380    invalidateAttrs();
381    HasAttrs = false;
382  }
383
384#if 0
385  // FIXME: Once ownership is fully understood, we can enable this code
386  if (DeclContext *DC = dyn_cast<DeclContext>(this))
387    DC->decls_begin()->Destroy(C);
388
389  // Observe the unrolled recursion.  By setting N->NextDeclInContext = 0x0
390  // within the loop, only the Destroy method for the first Decl
391  // will deallocate all of the Decls in a chain.
392
393  Decl* N = getNextDeclInContext();
394
395  while (N) {
396    Decl* Tmp = N->getNextDeclInContext();
397    N->NextDeclInContext = 0;
398    N->Destroy(C);
399    N = Tmp;
400  }
401
402  if (isOutOfSemaDC())
403    delete (C) getMultipleDC();
404
405  this->~Decl();
406  C.Deallocate((void *)this);
407#endif
408}
409
410Decl *Decl::castFromDeclContext (const DeclContext *D) {
411  Decl::Kind DK = D->getDeclKind();
412  switch(DK) {
413#define DECL(NAME, BASE)
414#define DECL_CONTEXT(NAME) \
415    case Decl::NAME:       \
416      return static_cast<NAME##Decl*>(const_cast<DeclContext*>(D));
417#define DECL_CONTEXT_BASE(NAME)
418#include "clang/AST/DeclNodes.inc"
419    default:
420#define DECL(NAME, BASE)
421#define DECL_CONTEXT_BASE(NAME)                  \
422      if (DK >= first##NAME && DK <= last##NAME) \
423        return static_cast<NAME##Decl*>(const_cast<DeclContext*>(D));
424#include "clang/AST/DeclNodes.inc"
425      assert(false && "a decl that inherits DeclContext isn't handled");
426      return 0;
427  }
428}
429
430DeclContext *Decl::castToDeclContext(const Decl *D) {
431  Decl::Kind DK = D->getKind();
432  switch(DK) {
433#define DECL(NAME, BASE)
434#define DECL_CONTEXT(NAME) \
435    case Decl::NAME:       \
436      return static_cast<NAME##Decl*>(const_cast<Decl*>(D));
437#define DECL_CONTEXT_BASE(NAME)
438#include "clang/AST/DeclNodes.inc"
439    default:
440#define DECL(NAME, BASE)
441#define DECL_CONTEXT_BASE(NAME)                                   \
442      if (DK >= first##NAME && DK <= last##NAME)                  \
443        return static_cast<NAME##Decl*>(const_cast<Decl*>(D));
444#include "clang/AST/DeclNodes.inc"
445      assert(false && "a decl that inherits DeclContext isn't handled");
446      return 0;
447  }
448}
449
450CompoundStmt* Decl::getCompoundBody() const {
451  return dyn_cast_or_null<CompoundStmt>(getBody());
452}
453
454SourceLocation Decl::getBodyRBrace() const {
455  Stmt *Body = getBody();
456  if (!Body)
457    return SourceLocation();
458  if (CompoundStmt *CS = dyn_cast<CompoundStmt>(Body))
459    return CS->getRBracLoc();
460  assert(isa<CXXTryStmt>(Body) &&
461         "Body can only be CompoundStmt or CXXTryStmt");
462  return cast<CXXTryStmt>(Body)->getSourceRange().getEnd();
463}
464
465#ifndef NDEBUG
466void Decl::CheckAccessDeclContext() const {
467  // FIXME: Disable this until rdar://8146294 "access specifier for inner class
468  // templates is not set or checked" is fixed.
469  return;
470  // Suppress this check if any of the following hold:
471  // 1. this is the translation unit (and thus has no parent)
472  // 2. this is a template parameter (and thus doesn't belong to its context)
473  // 3. the context is not a record
474  // 4. it's invalid
475  if (isa<TranslationUnitDecl>(this) ||
476      isa<TemplateTypeParmDecl>(this) ||
477      !isa<CXXRecordDecl>(getDeclContext()) ||
478      isInvalidDecl())
479    return;
480
481  assert(Access != AS_none &&
482         "Access specifier is AS_none inside a record decl");
483}
484
485#endif
486
487//===----------------------------------------------------------------------===//
488// DeclContext Implementation
489//===----------------------------------------------------------------------===//
490
491bool DeclContext::classof(const Decl *D) {
492  switch (D->getKind()) {
493#define DECL(NAME, BASE)
494#define DECL_CONTEXT(NAME) case Decl::NAME:
495#define DECL_CONTEXT_BASE(NAME)
496#include "clang/AST/DeclNodes.inc"
497      return true;
498    default:
499#define DECL(NAME, BASE)
500#define DECL_CONTEXT_BASE(NAME)                 \
501      if (D->getKind() >= Decl::first##NAME &&  \
502          D->getKind() <= Decl::last##NAME)     \
503        return true;
504#include "clang/AST/DeclNodes.inc"
505      return false;
506  }
507}
508
509DeclContext::~DeclContext() {
510  // FIXME: Currently ~ASTContext will delete the StoredDeclsMaps because
511  // ~DeclContext() is not guaranteed to be called when ASTContext uses
512  // a BumpPtrAllocator.
513  // delete LookupPtr;
514}
515
516void DeclContext::DestroyDecls(ASTContext &C) {
517  for (decl_iterator D = decls_begin(); D != decls_end(); )
518    (*D++)->Destroy(C);
519}
520
521/// \brief Find the parent context of this context that will be
522/// used for unqualified name lookup.
523///
524/// Generally, the parent lookup context is the semantic context. However, for
525/// a friend function the parent lookup context is the lexical context, which
526/// is the class in which the friend is declared.
527DeclContext *DeclContext::getLookupParent() {
528  // FIXME: Find a better way to identify friends
529  if (isa<FunctionDecl>(this))
530    if (getParent()->getLookupContext()->isFileContext() &&
531        getLexicalParent()->getLookupContext()->isRecord())
532      return getLexicalParent();
533
534  return getParent();
535}
536
537bool DeclContext::isDependentContext() const {
538  if (isFileContext())
539    return false;
540
541  if (isa<ClassTemplatePartialSpecializationDecl>(this))
542    return true;
543
544  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(this))
545    if (Record->getDescribedClassTemplate())
546      return true;
547
548  if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(this)) {
549    if (Function->getDescribedFunctionTemplate())
550      return true;
551
552    // Friend function declarations are dependent if their *lexical*
553    // context is dependent.
554    if (cast<Decl>(this)->getFriendObjectKind())
555      return getLexicalParent()->isDependentContext();
556  }
557
558  return getParent() && getParent()->isDependentContext();
559}
560
561bool DeclContext::isTransparentContext() const {
562  if (DeclKind == Decl::Enum)
563    return true; // FIXME: Check for C++0x scoped enums
564  else if (DeclKind == Decl::LinkageSpec)
565    return true;
566  else if (DeclKind >= Decl::firstRecord && DeclKind <= Decl::lastRecord)
567    return cast<RecordDecl>(this)->isAnonymousStructOrUnion();
568  else if (DeclKind == Decl::Namespace)
569    return false; // FIXME: Check for C++0x inline namespaces
570
571  return false;
572}
573
574bool DeclContext::Encloses(DeclContext *DC) {
575  if (getPrimaryContext() != this)
576    return getPrimaryContext()->Encloses(DC);
577
578  for (; DC; DC = DC->getParent())
579    if (DC->getPrimaryContext() == this)
580      return true;
581  return false;
582}
583
584DeclContext *DeclContext::getPrimaryContext() {
585  switch (DeclKind) {
586  case Decl::TranslationUnit:
587  case Decl::LinkageSpec:
588  case Decl::Block:
589    // There is only one DeclContext for these entities.
590    return this;
591
592  case Decl::Namespace:
593    // The original namespace is our primary context.
594    return static_cast<NamespaceDecl*>(this)->getOriginalNamespace();
595
596  case Decl::ObjCMethod:
597    return this;
598
599  case Decl::ObjCInterface:
600  case Decl::ObjCProtocol:
601  case Decl::ObjCCategory:
602    // FIXME: Can Objective-C interfaces be forward-declared?
603    return this;
604
605  case Decl::ObjCImplementation:
606  case Decl::ObjCCategoryImpl:
607    return this;
608
609  default:
610    if (DeclKind >= Decl::firstTag && DeclKind <= Decl::lastTag) {
611      // If this is a tag type that has a definition or is currently
612      // being defined, that definition is our primary context.
613      TagDecl *Tag = cast<TagDecl>(this);
614      assert(isa<TagType>(Tag->TypeForDecl) ||
615             isa<InjectedClassNameType>(Tag->TypeForDecl));
616
617      if (TagDecl *Def = Tag->getDefinition())
618        return Def;
619
620      if (!isa<InjectedClassNameType>(Tag->TypeForDecl)) {
621        const TagType *TagTy = cast<TagType>(Tag->TypeForDecl);
622        if (TagTy->isBeingDefined())
623          // FIXME: is it necessarily being defined in the decl
624          // that owns the type?
625          return TagTy->getDecl();
626      }
627
628      return Tag;
629    }
630
631    assert(DeclKind >= Decl::firstFunction && DeclKind <= Decl::lastFunction &&
632          "Unknown DeclContext kind");
633    return this;
634  }
635}
636
637DeclContext *DeclContext::getNextContext() {
638  switch (DeclKind) {
639  case Decl::Namespace:
640    // Return the next namespace
641    return static_cast<NamespaceDecl*>(this)->getNextNamespace();
642
643  default:
644    return 0;
645  }
646}
647
648/// \brief Load the declarations within this lexical storage from an
649/// external source.
650void
651DeclContext::LoadLexicalDeclsFromExternalStorage() const {
652  ExternalASTSource *Source = getParentASTContext().getExternalSource();
653  assert(hasExternalLexicalStorage() && Source && "No external storage?");
654
655  llvm::SmallVector<Decl*, 64> Decls;
656  if (Source->FindExternalLexicalDecls(this, Decls))
657    return;
658
659  // There is no longer any lexical storage in this context
660  ExternalLexicalStorage = false;
661
662  if (Decls.empty())
663    return;
664
665  // Resolve all of the declaration IDs into declarations, building up
666  // a chain of declarations via the Decl::NextDeclInContext field.
667  Decl *FirstNewDecl = 0;
668  Decl *PrevDecl = 0;
669  for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
670    Decl *D = Decls[I];
671    if (PrevDecl)
672      PrevDecl->NextDeclInContext = D;
673    else
674      FirstNewDecl = D;
675
676    PrevDecl = D;
677  }
678
679  // Splice the newly-read declarations into the beginning of the list
680  // of declarations.
681  PrevDecl->NextDeclInContext = FirstDecl;
682  FirstDecl = FirstNewDecl;
683  if (!LastDecl)
684    LastDecl = PrevDecl;
685}
686
687DeclContext::lookup_result
688ExternalASTSource::SetNoExternalVisibleDeclsForName(const DeclContext *DC,
689                                                    DeclarationName Name) {
690  ASTContext &Context = DC->getParentASTContext();
691  StoredDeclsMap *Map;
692  if (!(Map = DC->LookupPtr))
693    Map = DC->CreateStoredDeclsMap(Context);
694
695  StoredDeclsList &List = (*Map)[Name];
696  assert(List.isNull());
697  (void) List;
698
699  return DeclContext::lookup_result();
700}
701
702DeclContext::lookup_result
703ExternalASTSource::SetExternalVisibleDeclsForName(const DeclContext *DC,
704                                          const VisibleDeclaration &VD) {
705  ASTContext &Context = DC->getParentASTContext();
706  StoredDeclsMap *Map;
707  if (!(Map = DC->LookupPtr))
708    Map = DC->CreateStoredDeclsMap(Context);
709
710  StoredDeclsList &List = (*Map)[VD.Name];
711  List.setFromDeclIDs(VD.Declarations);
712  return List.getLookupResult(Context);
713}
714
715DeclContext::lookup_result
716ExternalASTSource::SetExternalVisibleDeclsForName(const DeclContext *DC,
717                                                  DeclarationName Name,
718                                    llvm::SmallVectorImpl<NamedDecl*> &Decls) {
719  ASTContext &Context = DC->getParentASTContext();;
720
721  StoredDeclsMap *Map;
722  if (!(Map = DC->LookupPtr))
723    Map = DC->CreateStoredDeclsMap(Context);
724
725  StoredDeclsList &List = (*Map)[Name];
726  for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
727    if (List.isNull())
728      List.setOnlyValue(Decls[I]);
729    else
730      List.AddSubsequentDecl(Decls[I]);
731  }
732
733  return List.getLookupResult(Context);
734}
735
736void ExternalASTSource::SetExternalVisibleDecls(const DeclContext *DC,
737                    const llvm::SmallVectorImpl<VisibleDeclaration> &Decls) {
738  // There is no longer any visible storage in this context.
739  DC->ExternalVisibleStorage = false;
740
741  assert(!DC->LookupPtr && "Have a lookup map before de-serialization?");
742  StoredDeclsMap *Map = DC->CreateStoredDeclsMap(DC->getParentASTContext());
743  for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
744    (*Map)[Decls[I].Name].setFromDeclIDs(Decls[I].Declarations);
745  }
746}
747
748void ExternalASTSource::SetExternalVisibleDecls(const DeclContext *DC,
749                            const llvm::SmallVectorImpl<NamedDecl*> &Decls) {
750  // There is no longer any visible storage in this context.
751  DC->ExternalVisibleStorage = false;
752
753  assert(!DC->LookupPtr && "Have a lookup map before de-serialization?");
754  StoredDeclsMap &Map = *DC->CreateStoredDeclsMap(DC->getParentASTContext());
755  for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
756    StoredDeclsList &List = Map[Decls[I]->getDeclName()];
757    if (List.isNull())
758      List.setOnlyValue(Decls[I]);
759    else
760      List.AddSubsequentDecl(Decls[I]);
761  }
762}
763
764DeclContext::decl_iterator DeclContext::decls_begin() const {
765  if (hasExternalLexicalStorage())
766    LoadLexicalDeclsFromExternalStorage();
767
768  // FIXME: Check whether we need to load some declarations from
769  // external storage.
770  return decl_iterator(FirstDecl);
771}
772
773DeclContext::decl_iterator DeclContext::decls_end() const {
774  if (hasExternalLexicalStorage())
775    LoadLexicalDeclsFromExternalStorage();
776
777  return decl_iterator();
778}
779
780bool DeclContext::decls_empty() const {
781  if (hasExternalLexicalStorage())
782    LoadLexicalDeclsFromExternalStorage();
783
784  return !FirstDecl;
785}
786
787void DeclContext::removeDecl(Decl *D) {
788  assert(D->getLexicalDeclContext() == this &&
789         "decl being removed from non-lexical context");
790  assert((D->NextDeclInContext || D == LastDecl) &&
791         "decl is not in decls list");
792
793  // Remove D from the decl chain.  This is O(n) but hopefully rare.
794  if (D == FirstDecl) {
795    if (D == LastDecl)
796      FirstDecl = LastDecl = 0;
797    else
798      FirstDecl = D->NextDeclInContext;
799  } else {
800    for (Decl *I = FirstDecl; true; I = I->NextDeclInContext) {
801      assert(I && "decl not found in linked list");
802      if (I->NextDeclInContext == D) {
803        I->NextDeclInContext = D->NextDeclInContext;
804        if (D == LastDecl) LastDecl = I;
805        break;
806      }
807    }
808  }
809
810  // Mark that D is no longer in the decl chain.
811  D->NextDeclInContext = 0;
812
813  // Remove D from the lookup table if necessary.
814  if (isa<NamedDecl>(D)) {
815    NamedDecl *ND = cast<NamedDecl>(D);
816
817    StoredDeclsMap *Map = getPrimaryContext()->LookupPtr;
818    if (!Map) return;
819
820    StoredDeclsMap::iterator Pos = Map->find(ND->getDeclName());
821    assert(Pos != Map->end() && "no lookup entry for decl");
822    Pos->second.remove(ND);
823  }
824}
825
826void DeclContext::addHiddenDecl(Decl *D) {
827  assert(D->getLexicalDeclContext() == this &&
828         "Decl inserted into wrong lexical context");
829  assert(!D->getNextDeclInContext() && D != LastDecl &&
830         "Decl already inserted into a DeclContext");
831
832  if (FirstDecl) {
833    LastDecl->NextDeclInContext = D;
834    LastDecl = D;
835  } else {
836    FirstDecl = LastDecl = D;
837  }
838}
839
840void DeclContext::addDecl(Decl *D) {
841  addHiddenDecl(D);
842
843  if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
844    ND->getDeclContext()->makeDeclVisibleInContext(ND);
845}
846
847/// buildLookup - Build the lookup data structure with all of the
848/// declarations in DCtx (and any other contexts linked to it or
849/// transparent contexts nested within it).
850void DeclContext::buildLookup(DeclContext *DCtx) {
851  for (; DCtx; DCtx = DCtx->getNextContext()) {
852    for (decl_iterator D = DCtx->decls_begin(),
853                    DEnd = DCtx->decls_end();
854         D != DEnd; ++D) {
855      // Insert this declaration into the lookup structure, but only
856      // if it's semantically in its decl context.  During non-lazy
857      // lookup building, this is implicitly enforced by addDecl.
858      if (NamedDecl *ND = dyn_cast<NamedDecl>(*D))
859        if (D->getDeclContext() == DCtx)
860          makeDeclVisibleInContextImpl(ND);
861
862      // Insert any forward-declared Objective-C interfaces into the lookup
863      // data structure.
864      if (ObjCClassDecl *Class = dyn_cast<ObjCClassDecl>(*D))
865        for (ObjCClassDecl::iterator I = Class->begin(), IEnd = Class->end();
866             I != IEnd; ++I)
867          makeDeclVisibleInContextImpl(I->getInterface());
868
869      // If this declaration is itself a transparent declaration context,
870      // add its members (recursively).
871      if (DeclContext *InnerCtx = dyn_cast<DeclContext>(*D))
872        if (InnerCtx->isTransparentContext())
873          buildLookup(InnerCtx->getPrimaryContext());
874    }
875  }
876}
877
878DeclContext::lookup_result
879DeclContext::lookup(DeclarationName Name) {
880  DeclContext *PrimaryContext = getPrimaryContext();
881  if (PrimaryContext != this)
882    return PrimaryContext->lookup(Name);
883
884  if (hasExternalVisibleStorage()) {
885    // Check to see if we've already cached the lookup results.
886    if (LookupPtr) {
887      StoredDeclsMap::iterator I = LookupPtr->find(Name);
888      if (I != LookupPtr->end())
889        return I->second.getLookupResult(getParentASTContext());
890    }
891
892    ExternalASTSource *Source = getParentASTContext().getExternalSource();
893    return Source->FindExternalVisibleDeclsByName(this, Name);
894  }
895
896  /// If there is no lookup data structure, build one now by walking
897  /// all of the linked DeclContexts (in declaration order!) and
898  /// inserting their values.
899  if (!LookupPtr) {
900    buildLookup(this);
901
902    if (!LookupPtr)
903      return lookup_result(lookup_iterator(0), lookup_iterator(0));
904  }
905
906  StoredDeclsMap::iterator Pos = LookupPtr->find(Name);
907  if (Pos == LookupPtr->end())
908    return lookup_result(lookup_iterator(0), lookup_iterator(0));
909  return Pos->second.getLookupResult(getParentASTContext());
910}
911
912DeclContext::lookup_const_result
913DeclContext::lookup(DeclarationName Name) const {
914  return const_cast<DeclContext*>(this)->lookup(Name);
915}
916
917DeclContext *DeclContext::getLookupContext() {
918  DeclContext *Ctx = this;
919  // Skip through transparent contexts.
920  while (Ctx->isTransparentContext())
921    Ctx = Ctx->getParent();
922  return Ctx;
923}
924
925DeclContext *DeclContext::getEnclosingNamespaceContext() {
926  DeclContext *Ctx = this;
927  // Skip through non-namespace, non-translation-unit contexts.
928  while (!Ctx->isFileContext() || Ctx->isTransparentContext())
929    Ctx = Ctx->getParent();
930  return Ctx->getPrimaryContext();
931}
932
933void DeclContext::makeDeclVisibleInContext(NamedDecl *D, bool Recoverable) {
934  // FIXME: This feels like a hack. Should DeclarationName support
935  // template-ids, or is there a better way to keep specializations
936  // from being visible?
937  if (isa<ClassTemplateSpecializationDecl>(D))
938    return;
939  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
940    if (FD->isFunctionTemplateSpecialization())
941      return;
942
943  DeclContext *PrimaryContext = getPrimaryContext();
944  if (PrimaryContext != this) {
945    PrimaryContext->makeDeclVisibleInContext(D, Recoverable);
946    return;
947  }
948
949  // If we already have a lookup data structure, perform the insertion
950  // into it. If we haven't deserialized externally stored decls, deserialize
951  // them so we can add the decl. Otherwise, be lazy and don't build that
952  // structure until someone asks for it.
953  if (LookupPtr || !Recoverable || hasExternalVisibleStorage())
954    makeDeclVisibleInContextImpl(D);
955
956  // If we are a transparent context, insert into our parent context,
957  // too. This operation is recursive.
958  if (isTransparentContext())
959    getParent()->makeDeclVisibleInContext(D, Recoverable);
960}
961
962void DeclContext::makeDeclVisibleInContextImpl(NamedDecl *D) {
963  // Skip unnamed declarations.
964  if (!D->getDeclName())
965    return;
966
967  // FIXME: This feels like a hack. Should DeclarationName support
968  // template-ids, or is there a better way to keep specializations
969  // from being visible?
970  if (isa<ClassTemplateSpecializationDecl>(D))
971    return;
972
973  // If there is an external AST source, load any declarations it knows about
974  // with this declaration's name.
975  if (ExternalASTSource *Source = getParentASTContext().getExternalSource())
976    if (hasExternalVisibleStorage())
977      Source->FindExternalVisibleDeclsByName(this, D->getDeclName());
978
979  ASTContext *C = 0;
980  if (!LookupPtr) {
981    C = &getParentASTContext();
982    CreateStoredDeclsMap(*C);
983  }
984
985  // Insert this declaration into the map.
986  StoredDeclsList &DeclNameEntries = (*LookupPtr)[D->getDeclName()];
987  if (DeclNameEntries.isNull()) {
988    DeclNameEntries.setOnlyValue(D);
989    return;
990  }
991
992  // If it is possible that this is a redeclaration, check to see if there is
993  // already a decl for which declarationReplaces returns true.  If there is
994  // one, just replace it and return.
995  if (!C)
996    C = &getParentASTContext();
997
998  if (DeclNameEntries.HandleRedeclaration(*C, D))
999    return;
1000
1001  // Put this declaration into the appropriate slot.
1002  DeclNameEntries.AddSubsequentDecl(D);
1003}
1004
1005/// Returns iterator range [First, Last) of UsingDirectiveDecls stored within
1006/// this context.
1007DeclContext::udir_iterator_range
1008DeclContext::getUsingDirectives() const {
1009  lookup_const_result Result = lookup(UsingDirectiveDecl::getName());
1010  return udir_iterator_range(reinterpret_cast<udir_iterator>(Result.first),
1011                             reinterpret_cast<udir_iterator>(Result.second));
1012}
1013
1014void StoredDeclsList::materializeDecls(ASTContext &Context) {
1015  if (isNull())
1016    return;
1017
1018  switch ((DataKind)(Data & 0x03)) {
1019  case DK_Decl:
1020  case DK_Decl_Vector:
1021    break;
1022
1023  case DK_DeclID: {
1024    // Resolve this declaration ID to an actual declaration by
1025    // querying the external AST source.
1026    unsigned DeclID = Data >> 2;
1027
1028    ExternalASTSource *Source = Context.getExternalSource();
1029    assert(Source && "No external AST source available!");
1030
1031    Data = reinterpret_cast<uintptr_t>(Source->GetExternalDecl(DeclID));
1032    break;
1033  }
1034
1035  case DK_ID_Vector: {
1036    // We have a vector of declaration IDs. Resolve all of them to
1037    // actual declarations.
1038    VectorTy &Vector = *getAsVector();
1039    ExternalASTSource *Source = Context.getExternalSource();
1040    assert(Source && "No external AST source available!");
1041
1042    for (unsigned I = 0, N = Vector.size(); I != N; ++I)
1043      Vector[I] = reinterpret_cast<uintptr_t>(Source->GetExternalDecl(Vector[I]));
1044
1045    Data = (Data & ~0x03) | DK_Decl_Vector;
1046    break;
1047  }
1048  }
1049}
1050
1051//===----------------------------------------------------------------------===//
1052// Creation and Destruction of StoredDeclsMaps.                               //
1053//===----------------------------------------------------------------------===//
1054
1055StoredDeclsMap *DeclContext::CreateStoredDeclsMap(ASTContext &C) const {
1056  assert(!LookupPtr && "context already has a decls map");
1057  assert(getPrimaryContext() == this &&
1058         "creating decls map on non-primary context");
1059
1060  StoredDeclsMap *M;
1061  bool Dependent = isDependentContext();
1062  if (Dependent)
1063    M = new DependentStoredDeclsMap();
1064  else
1065    M = new StoredDeclsMap();
1066  M->Previous = C.LastSDM;
1067  C.LastSDM = llvm::PointerIntPair<StoredDeclsMap*,1>(M, Dependent);
1068  LookupPtr = M;
1069  return M;
1070}
1071
1072void ASTContext::ReleaseDeclContextMaps() {
1073  // It's okay to delete DependentStoredDeclsMaps via a StoredDeclsMap
1074  // pointer because the subclass doesn't add anything that needs to
1075  // be deleted.
1076
1077  StoredDeclsMap::DestroyAll(LastSDM.getPointer(), LastSDM.getInt());
1078}
1079
1080void StoredDeclsMap::DestroyAll(StoredDeclsMap *Map, bool Dependent) {
1081  while (Map) {
1082    // Advance the iteration before we invalidate memory.
1083    llvm::PointerIntPair<StoredDeclsMap*,1> Next = Map->Previous;
1084
1085    if (Dependent)
1086      delete static_cast<DependentStoredDeclsMap*>(Map);
1087    else
1088      delete Map;
1089
1090    Map = Next.getPointer();
1091    Dependent = Next.getInt();
1092  }
1093}
1094
1095DependentDiagnostic *DependentDiagnostic::Create(ASTContext &C,
1096                                                 DeclContext *Parent,
1097                                           const PartialDiagnostic &PDiag) {
1098  assert(Parent->isDependentContext()
1099         && "cannot iterate dependent diagnostics of non-dependent context");
1100  Parent = Parent->getPrimaryContext();
1101  if (!Parent->LookupPtr)
1102    Parent->CreateStoredDeclsMap(C);
1103
1104  DependentStoredDeclsMap *Map
1105    = static_cast<DependentStoredDeclsMap*>(Parent->LookupPtr);
1106
1107  // Allocate the copy of the PartialDiagnostic via the ASTContext's
1108  // BumpPtrAllocator, rather than the ASTContext itself.
1109  PartialDiagnostic::Storage *DiagStorage = 0;
1110  if (PDiag.hasStorage())
1111    DiagStorage = new (C) PartialDiagnostic::Storage;
1112
1113  DependentDiagnostic *DD = new (C) DependentDiagnostic(PDiag, DiagStorage);
1114
1115  // TODO: Maybe we shouldn't reverse the order during insertion.
1116  DD->NextDiagnostic = Map->FirstDiagnostic;
1117  Map->FirstDiagnostic = DD;
1118
1119  return DD;
1120}
1121