DeclBase.cpp revision b53e417ba487f4193ef3b0485b420e0fdae643a2 
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 "clang/AST/ASTMutationListener.h"
28#include "clang/Basic/TargetInfo.h"
29#include "llvm/ADT/DenseMap.h"
30#include "llvm/Support/raw_ostream.h"
31#include <algorithm>
32#include <cstdio>
33#include <vector>
34using namespace clang;
35
36//===----------------------------------------------------------------------===//
37//  Statistics
38//===----------------------------------------------------------------------===//
39
40#define DECL(DERIVED, BASE) static int n##DERIVED##s = 0;
41#define ABSTRACT_DECL(DECL)
42#include "clang/AST/DeclNodes.inc"
43
44static bool StatSwitch = false;
45
46const char *Decl::getDeclKindName() const {
47  switch (DeclKind) {
48  default: assert(0 && "Declaration not in DeclNodes.inc!");
49#define DECL(DERIVED, BASE) case DERIVED: return #DERIVED;
50#define ABSTRACT_DECL(DECL)
51#include "clang/AST/DeclNodes.inc"
52  }
53}
54
55void Decl::setInvalidDecl(bool Invalid) {
56  InvalidDecl = Invalid;
57  if (Invalid) {
58    // Defensive maneuver for ill-formed code: we're likely not to make it to
59    // a point where we set the access specifier, so default it to "public"
60    // to avoid triggering asserts elsewhere in the front end.
61    setAccess(AS_public);
62  }
63}
64
65const char *DeclContext::getDeclKindName() const {
66  switch (DeclKind) {
67  default: assert(0 && "Declaration context not in DeclNodes.inc!");
68#define DECL(DERIVED, BASE) case Decl::DERIVED: return #DERIVED;
69#define ABSTRACT_DECL(DECL)
70#include "clang/AST/DeclNodes.inc"
71  }
72}
73
74bool Decl::CollectingStats(bool Enable) {
75  if (Enable) StatSwitch = true;
76  return StatSwitch;
77}
78
79void Decl::PrintStats() {
80  fprintf(stderr, "*** Decl Stats:\n");
81
82  int totalDecls = 0;
83#define DECL(DERIVED, BASE) totalDecls += n##DERIVED##s;
84#define ABSTRACT_DECL(DECL)
85#include "clang/AST/DeclNodes.inc"
86  fprintf(stderr, "  %d decls total.\n", totalDecls);
87
88  int totalBytes = 0;
89#define DECL(DERIVED, BASE)                                             \
90  if (n##DERIVED##s > 0) {                                              \
91    totalBytes += (int)(n##DERIVED##s * sizeof(DERIVED##Decl));         \
92    fprintf(stderr, "    %d " #DERIVED " decls, %d each (%d bytes)\n",  \
93            n##DERIVED##s, (int)sizeof(DERIVED##Decl),                  \
94            (int)(n##DERIVED##s * sizeof(DERIVED##Decl)));              \
95  }
96#define ABSTRACT_DECL(DECL)
97#include "clang/AST/DeclNodes.inc"
98
99  fprintf(stderr, "Total bytes = %d\n", totalBytes);
100}
101
102void Decl::add(Kind k) {
103  switch (k) {
104  default: assert(0 && "Declaration not in DeclNodes.inc!");
105#define DECL(DERIVED, BASE) case DERIVED: ++n##DERIVED##s; break;
106#define ABSTRACT_DECL(DECL)
107#include "clang/AST/DeclNodes.inc"
108  }
109}
110
111bool Decl::isTemplateParameterPack() const {
112  if (const TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(this))
113    return TTP->isParameterPack();
114  if (const NonTypeTemplateParmDecl *NTTP
115                                = dyn_cast<NonTypeTemplateParmDecl>(this))
116    return NTTP->isParameterPack();
117  if (const TemplateTemplateParmDecl *TTP
118                                    = dyn_cast<TemplateTemplateParmDecl>(this))
119    return TTP->isParameterPack();
120  return false;
121}
122
123bool Decl::isParameterPack() const {
124  if (const ParmVarDecl *Parm = dyn_cast<ParmVarDecl>(this))
125    return Parm->isParameterPack();
126
127  return isTemplateParameterPack();
128}
129
130bool Decl::isFunctionOrFunctionTemplate() const {
131  if (const UsingShadowDecl *UD = dyn_cast<UsingShadowDecl>(this))
132    return UD->getTargetDecl()->isFunctionOrFunctionTemplate();
133
134  return isa<FunctionDecl>(this) || isa<FunctionTemplateDecl>(this);
135}
136
137bool Decl::isDefinedOutsideFunctionOrMethod() const {
138  for (const DeclContext *DC = getDeclContext();
139       DC && !DC->isTranslationUnit();
140       DC = DC->getParent())
141    if (DC->isFunctionOrMethod())
142      return false;
143
144  return true;
145}
146
147
148//===----------------------------------------------------------------------===//
149// PrettyStackTraceDecl Implementation
150//===----------------------------------------------------------------------===//
151
152void PrettyStackTraceDecl::print(llvm::raw_ostream &OS) const {
153  SourceLocation TheLoc = Loc;
154  if (TheLoc.isInvalid() && TheDecl)
155    TheLoc = TheDecl->getLocation();
156
157  if (TheLoc.isValid()) {
158    TheLoc.print(OS, SM);
159    OS << ": ";
160  }
161
162  OS << Message;
163
164  if (const NamedDecl *DN = dyn_cast_or_null<NamedDecl>(TheDecl))
165    OS << " '" << DN->getQualifiedNameAsString() << '\'';
166  OS << '\n';
167}
168
169//===----------------------------------------------------------------------===//
170// Decl Implementation
171//===----------------------------------------------------------------------===//
172
173// Out-of-line virtual method providing a home for Decl.
174Decl::~Decl() { }
175
176void Decl::setDeclContext(DeclContext *DC) {
177  DeclCtx = DC;
178}
179
180void Decl::setLexicalDeclContext(DeclContext *DC) {
181  if (DC == getLexicalDeclContext())
182    return;
183
184  if (isInSemaDC()) {
185    MultipleDC *MDC = new (getASTContext()) MultipleDC();
186    MDC->SemanticDC = getDeclContext();
187    MDC->LexicalDC = DC;
188    DeclCtx = MDC;
189  } else {
190    getMultipleDC()->LexicalDC = DC;
191  }
192}
193
194bool Decl::isInAnonymousNamespace() const {
195  const DeclContext *DC = getDeclContext();
196  do {
197    if (const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(DC))
198      if (ND->isAnonymousNamespace())
199        return true;
200  } while ((DC = DC->getParent()));
201
202  return false;
203}
204
205TranslationUnitDecl *Decl::getTranslationUnitDecl() {
206  if (TranslationUnitDecl *TUD = dyn_cast<TranslationUnitDecl>(this))
207    return TUD;
208
209  DeclContext *DC = getDeclContext();
210  assert(DC && "This decl is not contained in a translation unit!");
211
212  while (!DC->isTranslationUnit()) {
213    DC = DC->getParent();
214    assert(DC && "This decl is not contained in a translation unit!");
215  }
216
217  return cast<TranslationUnitDecl>(DC);
218}
219
220ASTContext &Decl::getASTContext() const {
221  return getTranslationUnitDecl()->getASTContext();
222}
223
224ASTMutationListener *Decl::getASTMutationListener() const {
225  return getASTContext().getASTMutationListener();
226}
227
228bool Decl::isUsed(bool CheckUsedAttr) const {
229  if (Used)
230    return true;
231
232  // Check for used attribute.
233  if (CheckUsedAttr && hasAttr<UsedAttr>())
234    return true;
235
236  // Check redeclarations for used attribute.
237  for (redecl_iterator I = redecls_begin(), E = redecls_end(); I != E; ++I) {
238    if ((CheckUsedAttr && I->hasAttr<UsedAttr>()) || I->Used)
239      return true;
240  }
241
242  return false;
243}
244
245/// \brief Determine the availability of the given declaration based on
246/// the target platform.
247///
248/// When it returns an availability result other than \c AR_Available,
249/// if the \p Message parameter is non-NULL, it will be set to a
250/// string describing why the entity is unavailable.
251///
252/// FIXME: Make these strings localizable, since they end up in
253/// diagnostics.
254static AvailabilityResult CheckAvailability(ASTContext &Context,
255                                            const AvailabilityAttr *A,
256                                            std::string *Message) {
257  llvm::StringRef TargetPlatform = Context.Target.getPlatformName();
258  llvm::StringRef PrettyPlatformName
259    = AvailabilityAttr::getPrettyPlatformName(TargetPlatform);
260  if (PrettyPlatformName.empty())
261    PrettyPlatformName = TargetPlatform;
262
263  VersionTuple TargetMinVersion = Context.Target.getPlatformMinVersion();
264  if (TargetMinVersion.empty())
265    return AR_Available;
266
267  // Match the platform name.
268  if (A->getPlatform()->getName() != TargetPlatform)
269    return AR_Available;
270
271  // Make sure that this declaration has not been marked 'unavailable'.
272  if (A->getUnavailable()) {
273    if (Message) {
274      Message->clear();
275      llvm::raw_string_ostream Out(*Message);
276      Out << "not available on " << PrettyPlatformName;
277    }
278
279    return AR_Unavailable;
280  }
281
282  // Make sure that this declaration has already been introduced.
283  if (!A->getIntroduced().empty() &&
284      TargetMinVersion < A->getIntroduced()) {
285    if (Message) {
286      Message->clear();
287      llvm::raw_string_ostream Out(*Message);
288      Out << "introduced in " << PrettyPlatformName << ' '
289          << A->getIntroduced();
290    }
291
292    return AR_NotYetIntroduced;
293  }
294
295  // Make sure that this declaration hasn't been obsoleted.
296  if (!A->getObsoleted().empty() && TargetMinVersion >= A->getObsoleted()) {
297    if (Message) {
298      Message->clear();
299      llvm::raw_string_ostream Out(*Message);
300      Out << "obsoleted in " << PrettyPlatformName << ' '
301          << A->getObsoleted();
302    }
303
304    return AR_Unavailable;
305  }
306
307  // Make sure that this declaration hasn't been deprecated.
308  if (!A->getDeprecated().empty() && TargetMinVersion >= A->getDeprecated()) {
309    if (Message) {
310      Message->clear();
311      llvm::raw_string_ostream Out(*Message);
312      Out << "first deprecated in " << PrettyPlatformName << ' '
313          << A->getDeprecated();
314    }
315
316    return AR_Deprecated;
317  }
318
319  return AR_Available;
320}
321
322AvailabilityResult Decl::getAvailability(std::string *Message) const {
323  AvailabilityResult Result = AR_Available;
324  std::string ResultMessage;
325
326  for (attr_iterator A = attr_begin(), AEnd = attr_end(); A != AEnd; ++A) {
327    if (DeprecatedAttr *Deprecated = dyn_cast<DeprecatedAttr>(*A)) {
328      if (Result >= AR_Deprecated)
329        continue;
330
331      if (Message)
332        ResultMessage = Deprecated->getMessage();
333
334      Result = AR_Deprecated;
335      continue;
336    }
337
338    if (UnavailableAttr *Unavailable = dyn_cast<UnavailableAttr>(*A)) {
339      if (Message)
340        *Message = Unavailable->getMessage();
341      return AR_Unavailable;
342    }
343
344    if (AvailabilityAttr *Availability = dyn_cast<AvailabilityAttr>(*A)) {
345      AvailabilityResult AR = CheckAvailability(getASTContext(), Availability,
346                                                Message);
347
348      if (AR == AR_Unavailable)
349        return AR_Unavailable;
350
351      if (AR > Result) {
352        Result = AR;
353        if (Message)
354          ResultMessage.swap(*Message);
355      }
356      continue;
357    }
358  }
359
360  if (Message)
361    Message->swap(ResultMessage);
362  return Result;
363}
364
365bool Decl::canBeWeakImported(bool &IsDefinition) const {
366  IsDefinition = false;
367  if (const VarDecl *Var = dyn_cast<VarDecl>(this)) {
368    if (!Var->hasExternalStorage() || Var->getInit()) {
369      IsDefinition = true;
370      return false;
371    }
372  } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(this)) {
373    if (FD->hasBody()) {
374      IsDefinition = true;
375      return false;
376    }
377  } else if (isa<ObjCPropertyDecl>(this) || isa<ObjCMethodDecl>(this))
378    return false;
379  else if (!(getASTContext().getLangOptions().ObjCNonFragileABI &&
380             isa<ObjCInterfaceDecl>(this)))
381    return false;
382
383  return true;
384}
385
386bool Decl::isWeakImported() const {
387  bool IsDefinition;
388  if (!canBeWeakImported(IsDefinition))
389    return false;
390
391  for (attr_iterator A = attr_begin(), AEnd = attr_end(); A != AEnd; ++A) {
392    if (isa<WeakImportAttr>(*A))
393      return true;
394
395    if (AvailabilityAttr *Availability = dyn_cast<AvailabilityAttr>(*A)) {
396      if (CheckAvailability(getASTContext(), Availability, 0)
397                                                         == AR_NotYetIntroduced)
398        return true;
399    }
400  }
401
402  return false;
403}
404
405unsigned Decl::getIdentifierNamespaceForKind(Kind DeclKind) {
406  switch (DeclKind) {
407    case Function:
408    case CXXMethod:
409    case CXXConstructor:
410    case CXXDestructor:
411    case CXXConversion:
412    case EnumConstant:
413    case Var:
414    case ImplicitParam:
415    case ParmVar:
416    case NonTypeTemplateParm:
417    case ObjCMethod:
418    case ObjCProperty:
419      return IDNS_Ordinary;
420    case Label:
421      return IDNS_Label;
422    case IndirectField:
423      return IDNS_Ordinary | IDNS_Member;
424
425    case ObjCCompatibleAlias:
426    case ObjCInterface:
427      return IDNS_Ordinary | IDNS_Type;
428
429    case Typedef:
430    case UnresolvedUsingTypename:
431    case TemplateTypeParm:
432      return IDNS_Ordinary | IDNS_Type;
433
434    case UsingShadow:
435      return 0; // we'll actually overwrite this later
436
437    case UnresolvedUsingValue:
438      return IDNS_Ordinary | IDNS_Using;
439
440    case Using:
441      return IDNS_Using;
442
443    case ObjCProtocol:
444      return IDNS_ObjCProtocol;
445
446    case Field:
447    case ObjCAtDefsField:
448    case ObjCIvar:
449      return IDNS_Member;
450
451    case Record:
452    case CXXRecord:
453    case Enum:
454      return IDNS_Tag | IDNS_Type;
455
456    case Namespace:
457    case NamespaceAlias:
458      return IDNS_Namespace;
459
460    case FunctionTemplate:
461      return IDNS_Ordinary;
462
463    case ClassTemplate:
464    case TemplateTemplateParm:
465      return IDNS_Ordinary | IDNS_Tag | IDNS_Type;
466
467    // Never have names.
468    case Friend:
469    case FriendTemplate:
470    case AccessSpec:
471    case LinkageSpec:
472    case FileScopeAsm:
473    case StaticAssert:
474    case ObjCClass:
475    case ObjCPropertyImpl:
476    case ObjCForwardProtocol:
477    case Block:
478    case TranslationUnit:
479
480    case UsingDirective:
481    case ClassTemplateSpecialization:
482    case ClassTemplatePartialSpecialization:
483    case ObjCImplementation:
484    case ObjCCategory:
485    case ObjCCategoryImpl:
486      // Never looked up by name.
487      return 0;
488  }
489
490  return 0;
491}
492
493void Decl::setAttrs(const AttrVec &attrs) {
494  assert(!HasAttrs && "Decl already contains attrs.");
495
496  AttrVec &AttrBlank = getASTContext().getDeclAttrs(this);
497  assert(AttrBlank.empty() && "HasAttrs was wrong?");
498
499  AttrBlank = attrs;
500  HasAttrs = true;
501}
502
503void Decl::dropAttrs() {
504  if (!HasAttrs) return;
505
506  HasAttrs = false;
507  getASTContext().eraseDeclAttrs(this);
508}
509
510const AttrVec &Decl::getAttrs() const {
511  assert(HasAttrs && "No attrs to get!");
512  return getASTContext().getDeclAttrs(this);
513}
514
515void Decl::swapAttrs(Decl *RHS) {
516  bool HasLHSAttr = this->HasAttrs;
517  bool HasRHSAttr = RHS->HasAttrs;
518
519  // Usually, neither decl has attrs, nothing to do.
520  if (!HasLHSAttr && !HasRHSAttr) return;
521
522  // If 'this' has no attrs, swap the other way.
523  if (!HasLHSAttr)
524    return RHS->swapAttrs(this);
525
526  ASTContext &Context = getASTContext();
527
528  // Handle the case when both decls have attrs.
529  if (HasRHSAttr) {
530    std::swap(Context.getDeclAttrs(this), Context.getDeclAttrs(RHS));
531    return;
532  }
533
534  // Otherwise, LHS has an attr and RHS doesn't.
535  Context.getDeclAttrs(RHS) = Context.getDeclAttrs(this);
536  Context.eraseDeclAttrs(this);
537  this->HasAttrs = false;
538  RHS->HasAttrs = true;
539}
540
541Decl *Decl::castFromDeclContext (const DeclContext *D) {
542  Decl::Kind DK = D->getDeclKind();
543  switch(DK) {
544#define DECL(NAME, BASE)
545#define DECL_CONTEXT(NAME) \
546    case Decl::NAME:       \
547      return static_cast<NAME##Decl*>(const_cast<DeclContext*>(D));
548#define DECL_CONTEXT_BASE(NAME)
549#include "clang/AST/DeclNodes.inc"
550    default:
551#define DECL(NAME, BASE)
552#define DECL_CONTEXT_BASE(NAME)                  \
553      if (DK >= first##NAME && DK <= last##NAME) \
554        return static_cast<NAME##Decl*>(const_cast<DeclContext*>(D));
555#include "clang/AST/DeclNodes.inc"
556      assert(false && "a decl that inherits DeclContext isn't handled");
557      return 0;
558  }
559}
560
561DeclContext *Decl::castToDeclContext(const Decl *D) {
562  Decl::Kind DK = D->getKind();
563  switch(DK) {
564#define DECL(NAME, BASE)
565#define DECL_CONTEXT(NAME) \
566    case Decl::NAME:       \
567      return static_cast<NAME##Decl*>(const_cast<Decl*>(D));
568#define DECL_CONTEXT_BASE(NAME)
569#include "clang/AST/DeclNodes.inc"
570    default:
571#define DECL(NAME, BASE)
572#define DECL_CONTEXT_BASE(NAME)                                   \
573      if (DK >= first##NAME && DK <= last##NAME)                  \
574        return static_cast<NAME##Decl*>(const_cast<Decl*>(D));
575#include "clang/AST/DeclNodes.inc"
576      assert(false && "a decl that inherits DeclContext isn't handled");
577      return 0;
578  }
579}
580
581SourceLocation Decl::getBodyRBrace() const {
582  // Special handling of FunctionDecl to avoid de-serializing the body from PCH.
583  // FunctionDecl stores EndRangeLoc for this purpose.
584  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(this)) {
585    const FunctionDecl *Definition;
586    if (FD->hasBody(Definition))
587      return Definition->getSourceRange().getEnd();
588    return SourceLocation();
589  }
590
591  if (Stmt *Body = getBody())
592    return Body->getSourceRange().getEnd();
593
594  return SourceLocation();
595}
596
597void Decl::CheckAccessDeclContext() const {
598#ifndef NDEBUG
599  // Suppress this check if any of the following hold:
600  // 1. this is the translation unit (and thus has no parent)
601  // 2. this is a template parameter (and thus doesn't belong to its context)
602  // 3. this is a non-type template parameter
603  // 4. the context is not a record
604  // 5. it's invalid
605  // 6. it's a C++0x static_assert.
606  if (isa<TranslationUnitDecl>(this) ||
607      isa<TemplateTypeParmDecl>(this) ||
608      isa<NonTypeTemplateParmDecl>(this) ||
609      !isa<CXXRecordDecl>(getDeclContext()) ||
610      isInvalidDecl() ||
611      isa<StaticAssertDecl>(this) ||
612      // FIXME: a ParmVarDecl can have ClassTemplateSpecialization
613      // as DeclContext (?).
614      isa<ParmVarDecl>(this) ||
615      // FIXME: a ClassTemplateSpecialization or CXXRecordDecl can have
616      // AS_none as access specifier.
617      isa<CXXRecordDecl>(this))
618    return;
619
620  assert(Access != AS_none &&
621         "Access specifier is AS_none inside a record decl");
622#endif
623}
624
625DeclContext *Decl::getNonClosureContext() {
626  DeclContext *DC = getDeclContext();
627
628  // This is basically "while (DC->isClosure()) DC = DC->getParent();"
629  // except that it's significantly more efficient to cast to a known
630  // decl type and call getDeclContext() than to call getParent().
631  do {
632    if (isa<BlockDecl>(DC)) {
633      DC = cast<BlockDecl>(DC)->getDeclContext();
634      continue;
635    }
636  } while (false);
637
638  assert(!DC->isClosure());
639  return DC;
640}
641
642//===----------------------------------------------------------------------===//
643// DeclContext Implementation
644//===----------------------------------------------------------------------===//
645
646bool DeclContext::classof(const Decl *D) {
647  switch (D->getKind()) {
648#define DECL(NAME, BASE)
649#define DECL_CONTEXT(NAME) case Decl::NAME:
650#define DECL_CONTEXT_BASE(NAME)
651#include "clang/AST/DeclNodes.inc"
652      return true;
653    default:
654#define DECL(NAME, BASE)
655#define DECL_CONTEXT_BASE(NAME)                 \
656      if (D->getKind() >= Decl::first##NAME &&  \
657          D->getKind() <= Decl::last##NAME)     \
658        return true;
659#include "clang/AST/DeclNodes.inc"
660      return false;
661  }
662}
663
664DeclContext::~DeclContext() { }
665
666/// \brief Find the parent context of this context that will be
667/// used for unqualified name lookup.
668///
669/// Generally, the parent lookup context is the semantic context. However, for
670/// a friend function the parent lookup context is the lexical context, which
671/// is the class in which the friend is declared.
672DeclContext *DeclContext::getLookupParent() {
673  // FIXME: Find a better way to identify friends
674  if (isa<FunctionDecl>(this))
675    if (getParent()->getRedeclContext()->isFileContext() &&
676        getLexicalParent()->getRedeclContext()->isRecord())
677      return getLexicalParent();
678
679  return getParent();
680}
681
682bool DeclContext::isInlineNamespace() const {
683  return isNamespace() &&
684         cast<NamespaceDecl>(this)->isInline();
685}
686
687bool DeclContext::isDependentContext() const {
688  if (isFileContext())
689    return false;
690
691  if (isa<ClassTemplatePartialSpecializationDecl>(this))
692    return true;
693
694  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(this))
695    if (Record->getDescribedClassTemplate())
696      return true;
697
698  if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(this)) {
699    if (Function->getDescribedFunctionTemplate())
700      return true;
701
702    // Friend function declarations are dependent if their *lexical*
703    // context is dependent.
704    if (cast<Decl>(this)->getFriendObjectKind())
705      return getLexicalParent()->isDependentContext();
706  }
707
708  return getParent() && getParent()->isDependentContext();
709}
710
711bool DeclContext::isTransparentContext() const {
712  if (DeclKind == Decl::Enum)
713    return !cast<EnumDecl>(this)->isScoped();
714  else if (DeclKind == Decl::LinkageSpec)
715    return true;
716
717  return false;
718}
719
720bool DeclContext::isExternCContext() const {
721  const DeclContext *DC = this;
722  while (DC->DeclKind != Decl::TranslationUnit) {
723    if (DC->DeclKind == Decl::LinkageSpec)
724      return cast<LinkageSpecDecl>(DC)->getLanguage()
725        == LinkageSpecDecl::lang_c;
726    DC = DC->getParent();
727  }
728  return false;
729}
730
731bool DeclContext::Encloses(const DeclContext *DC) const {
732  if (getPrimaryContext() != this)
733    return getPrimaryContext()->Encloses(DC);
734
735  for (; DC; DC = DC->getParent())
736    if (DC->getPrimaryContext() == this)
737      return true;
738  return false;
739}
740
741DeclContext *DeclContext::getPrimaryContext() {
742  switch (DeclKind) {
743  case Decl::TranslationUnit:
744  case Decl::LinkageSpec:
745  case Decl::Block:
746    // There is only one DeclContext for these entities.
747    return this;
748
749  case Decl::Namespace:
750    // The original namespace is our primary context.
751    return static_cast<NamespaceDecl*>(this)->getOriginalNamespace();
752
753  case Decl::ObjCMethod:
754    return this;
755
756  case Decl::ObjCInterface:
757  case Decl::ObjCProtocol:
758  case Decl::ObjCCategory:
759    // FIXME: Can Objective-C interfaces be forward-declared?
760    return this;
761
762  case Decl::ObjCImplementation:
763  case Decl::ObjCCategoryImpl:
764    return this;
765
766  default:
767    if (DeclKind >= Decl::firstTag && DeclKind <= Decl::lastTag) {
768      // If this is a tag type that has a definition or is currently
769      // being defined, that definition is our primary context.
770      TagDecl *Tag = cast<TagDecl>(this);
771      assert(isa<TagType>(Tag->TypeForDecl) ||
772             isa<InjectedClassNameType>(Tag->TypeForDecl));
773
774      if (TagDecl *Def = Tag->getDefinition())
775        return Def;
776
777      if (!isa<InjectedClassNameType>(Tag->TypeForDecl)) {
778        const TagType *TagTy = cast<TagType>(Tag->TypeForDecl);
779        if (TagTy->isBeingDefined())
780          // FIXME: is it necessarily being defined in the decl
781          // that owns the type?
782          return TagTy->getDecl();
783      }
784
785      return Tag;
786    }
787
788    assert(DeclKind >= Decl::firstFunction && DeclKind <= Decl::lastFunction &&
789          "Unknown DeclContext kind");
790    return this;
791  }
792}
793
794DeclContext *DeclContext::getNextContext() {
795  switch (DeclKind) {
796  case Decl::Namespace:
797    // Return the next namespace
798    return static_cast<NamespaceDecl*>(this)->getNextNamespace();
799
800  default:
801    return 0;
802  }
803}
804
805std::pair<Decl *, Decl *>
806DeclContext::BuildDeclChain(const llvm::SmallVectorImpl<Decl*> &Decls) {
807  // Build up a chain of declarations via the Decl::NextDeclInContext field.
808  Decl *FirstNewDecl = 0;
809  Decl *PrevDecl = 0;
810  for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
811    Decl *D = Decls[I];
812    if (PrevDecl)
813      PrevDecl->NextDeclInContext = D;
814    else
815      FirstNewDecl = D;
816
817    PrevDecl = D;
818  }
819
820  return std::make_pair(FirstNewDecl, PrevDecl);
821}
822
823/// \brief Load the declarations within this lexical storage from an
824/// external source.
825void
826DeclContext::LoadLexicalDeclsFromExternalStorage() const {
827  ExternalASTSource *Source = getParentASTContext().getExternalSource();
828  assert(hasExternalLexicalStorage() && Source && "No external storage?");
829
830  // Notify that we have a DeclContext that is initializing.
831  ExternalASTSource::Deserializing ADeclContext(Source);
832
833  llvm::SmallVector<Decl*, 64> Decls;
834  if (Source->FindExternalLexicalDecls(this, Decls))
835    return;
836
837  // There is no longer any lexical storage in this context
838  ExternalLexicalStorage = false;
839
840  if (Decls.empty())
841    return;
842
843  // We may have already loaded just the fields of this record, in which case
844  // don't add the decls, just replace the FirstDecl/LastDecl chain.
845  if (const RecordDecl *RD = dyn_cast<RecordDecl>(this))
846    if (RD->LoadedFieldsFromExternalStorage) {
847      llvm::tie(FirstDecl, LastDecl) = BuildDeclChain(Decls);
848      return;
849    }
850
851  // Splice the newly-read declarations into the beginning of the list
852  // of declarations.
853  Decl *ExternalFirst, *ExternalLast;
854  llvm::tie(ExternalFirst, ExternalLast) = BuildDeclChain(Decls);
855  ExternalLast->NextDeclInContext = FirstDecl;
856  FirstDecl = ExternalFirst;
857  if (!LastDecl)
858    LastDecl = ExternalLast;
859}
860
861DeclContext::lookup_result
862ExternalASTSource::SetNoExternalVisibleDeclsForName(const DeclContext *DC,
863                                                    DeclarationName Name) {
864  ASTContext &Context = DC->getParentASTContext();
865  StoredDeclsMap *Map;
866  if (!(Map = DC->LookupPtr))
867    Map = DC->CreateStoredDeclsMap(Context);
868
869  StoredDeclsList &List = (*Map)[Name];
870  assert(List.isNull());
871  (void) List;
872
873  return DeclContext::lookup_result();
874}
875
876DeclContext::lookup_result
877ExternalASTSource::SetExternalVisibleDeclsForName(const DeclContext *DC,
878                                                  DeclarationName Name,
879                                    llvm::SmallVectorImpl<NamedDecl*> &Decls) {
880  ASTContext &Context = DC->getParentASTContext();;
881
882  StoredDeclsMap *Map;
883  if (!(Map = DC->LookupPtr))
884    Map = DC->CreateStoredDeclsMap(Context);
885
886  StoredDeclsList &List = (*Map)[Name];
887  for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
888    if (List.isNull())
889      List.setOnlyValue(Decls[I]);
890    else
891      List.AddSubsequentDecl(Decls[I]);
892  }
893
894  return List.getLookupResult();
895}
896
897void ExternalASTSource::MaterializeVisibleDeclsForName(const DeclContext *DC,
898                                                       DeclarationName Name,
899                                     llvm::SmallVectorImpl<NamedDecl*> &Decls) {
900  assert(DC->LookupPtr);
901  StoredDeclsMap &Map = *DC->LookupPtr;
902
903  // If there's an entry in the table the visible decls for this name have
904  // already been deserialized.
905  if (Map.find(Name) == Map.end()) {
906    StoredDeclsList &List = Map[Name];
907    for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
908      if (List.isNull())
909        List.setOnlyValue(Decls[I]);
910      else
911        List.AddSubsequentDecl(Decls[I]);
912    }
913  }
914}
915
916DeclContext::decl_iterator DeclContext::noload_decls_begin() const {
917  return decl_iterator(FirstDecl);
918}
919
920DeclContext::decl_iterator DeclContext::noload_decls_end() const {
921  return decl_iterator();
922}
923
924DeclContext::decl_iterator DeclContext::decls_begin() const {
925  if (hasExternalLexicalStorage())
926    LoadLexicalDeclsFromExternalStorage();
927
928  // FIXME: Check whether we need to load some declarations from
929  // external storage.
930  return decl_iterator(FirstDecl);
931}
932
933DeclContext::decl_iterator DeclContext::decls_end() const {
934  if (hasExternalLexicalStorage())
935    LoadLexicalDeclsFromExternalStorage();
936
937  return decl_iterator();
938}
939
940bool DeclContext::decls_empty() const {
941  if (hasExternalLexicalStorage())
942    LoadLexicalDeclsFromExternalStorage();
943
944  return !FirstDecl;
945}
946
947void DeclContext::removeDecl(Decl *D) {
948  assert(D->getLexicalDeclContext() == this &&
949         "decl being removed from non-lexical context");
950  assert((D->NextDeclInContext || D == LastDecl) &&
951         "decl is not in decls list");
952
953  // Remove D from the decl chain.  This is O(n) but hopefully rare.
954  if (D == FirstDecl) {
955    if (D == LastDecl)
956      FirstDecl = LastDecl = 0;
957    else
958      FirstDecl = D->NextDeclInContext;
959  } else {
960    for (Decl *I = FirstDecl; true; I = I->NextDeclInContext) {
961      assert(I && "decl not found in linked list");
962      if (I->NextDeclInContext == D) {
963        I->NextDeclInContext = D->NextDeclInContext;
964        if (D == LastDecl) LastDecl = I;
965        break;
966      }
967    }
968  }
969
970  // Mark that D is no longer in the decl chain.
971  D->NextDeclInContext = 0;
972
973  // Remove D from the lookup table if necessary.
974  if (isa<NamedDecl>(D)) {
975    NamedDecl *ND = cast<NamedDecl>(D);
976
977    StoredDeclsMap *Map = getPrimaryContext()->LookupPtr;
978    if (!Map) return;
979
980    StoredDeclsMap::iterator Pos = Map->find(ND->getDeclName());
981    assert(Pos != Map->end() && "no lookup entry for decl");
982    Pos->second.remove(ND);
983  }
984}
985
986void DeclContext::addHiddenDecl(Decl *D) {
987  assert(D->getLexicalDeclContext() == this &&
988         "Decl inserted into wrong lexical context");
989  assert(!D->getNextDeclInContext() && D != LastDecl &&
990         "Decl already inserted into a DeclContext");
991
992  if (FirstDecl) {
993    LastDecl->NextDeclInContext = D;
994    LastDecl = D;
995  } else {
996    FirstDecl = LastDecl = D;
997  }
998
999  // Notify a C++ record declaration that we've added a member, so it can
1000  // update it's class-specific state.
1001  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(this))
1002    Record->addedMember(D);
1003}
1004
1005void DeclContext::addDecl(Decl *D) {
1006  addHiddenDecl(D);
1007
1008  if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
1009    ND->getDeclContext()->makeDeclVisibleInContext(ND);
1010}
1011
1012/// buildLookup - Build the lookup data structure with all of the
1013/// declarations in DCtx (and any other contexts linked to it or
1014/// transparent contexts nested within it).
1015void DeclContext::buildLookup(DeclContext *DCtx) {
1016  for (; DCtx; DCtx = DCtx->getNextContext()) {
1017    for (decl_iterator D = DCtx->decls_begin(),
1018                    DEnd = DCtx->decls_end();
1019         D != DEnd; ++D) {
1020      // Insert this declaration into the lookup structure, but only
1021      // if it's semantically in its decl context.  During non-lazy
1022      // lookup building, this is implicitly enforced by addDecl.
1023      if (NamedDecl *ND = dyn_cast<NamedDecl>(*D))
1024        if (D->getDeclContext() == DCtx)
1025          makeDeclVisibleInContextImpl(ND);
1026
1027      // Insert any forward-declared Objective-C interfaces into the lookup
1028      // data structure.
1029      if (ObjCClassDecl *Class = dyn_cast<ObjCClassDecl>(*D))
1030        for (ObjCClassDecl::iterator I = Class->begin(), IEnd = Class->end();
1031             I != IEnd; ++I)
1032          makeDeclVisibleInContextImpl(I->getInterface());
1033
1034      // If this declaration is itself a transparent declaration context or
1035      // inline namespace, add its members (recursively).
1036      if (DeclContext *InnerCtx = dyn_cast<DeclContext>(*D))
1037        if (InnerCtx->isTransparentContext() || InnerCtx->isInlineNamespace())
1038          buildLookup(InnerCtx->getPrimaryContext());
1039    }
1040  }
1041}
1042
1043DeclContext::lookup_result
1044DeclContext::lookup(DeclarationName Name) {
1045  DeclContext *PrimaryContext = getPrimaryContext();
1046  if (PrimaryContext != this)
1047    return PrimaryContext->lookup(Name);
1048
1049  if (hasExternalVisibleStorage()) {
1050    // Check to see if we've already cached the lookup results.
1051    if (LookupPtr) {
1052      StoredDeclsMap::iterator I = LookupPtr->find(Name);
1053      if (I != LookupPtr->end())
1054        return I->second.getLookupResult();
1055    }
1056
1057    ExternalASTSource *Source = getParentASTContext().getExternalSource();
1058    return Source->FindExternalVisibleDeclsByName(this, Name);
1059  }
1060
1061  /// If there is no lookup data structure, build one now by walking
1062  /// all of the linked DeclContexts (in declaration order!) and
1063  /// inserting their values.
1064  if (!LookupPtr) {
1065    buildLookup(this);
1066
1067    if (!LookupPtr)
1068      return lookup_result(lookup_iterator(0), lookup_iterator(0));
1069  }
1070
1071  StoredDeclsMap::iterator Pos = LookupPtr->find(Name);
1072  if (Pos == LookupPtr->end())
1073    return lookup_result(lookup_iterator(0), lookup_iterator(0));
1074  return Pos->second.getLookupResult();
1075}
1076
1077DeclContext::lookup_const_result
1078DeclContext::lookup(DeclarationName Name) const {
1079  return const_cast<DeclContext*>(this)->lookup(Name);
1080}
1081
1082DeclContext *DeclContext::getRedeclContext() {
1083  DeclContext *Ctx = this;
1084  // Skip through transparent contexts.
1085  while (Ctx->isTransparentContext())
1086    Ctx = Ctx->getParent();
1087  return Ctx;
1088}
1089
1090DeclContext *DeclContext::getEnclosingNamespaceContext() {
1091  DeclContext *Ctx = this;
1092  // Skip through non-namespace, non-translation-unit contexts.
1093  while (!Ctx->isFileContext())
1094    Ctx = Ctx->getParent();
1095  return Ctx->getPrimaryContext();
1096}
1097
1098bool DeclContext::InEnclosingNamespaceSetOf(const DeclContext *O) const {
1099  // For non-file contexts, this is equivalent to Equals.
1100  if (!isFileContext())
1101    return O->Equals(this);
1102
1103  do {
1104    if (O->Equals(this))
1105      return true;
1106
1107    const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(O);
1108    if (!NS || !NS->isInline())
1109      break;
1110    O = NS->getParent();
1111  } while (O);
1112
1113  return false;
1114}
1115
1116void DeclContext::makeDeclVisibleInContext(NamedDecl *D, bool Recoverable) {
1117  // FIXME: This feels like a hack. Should DeclarationName support
1118  // template-ids, or is there a better way to keep specializations
1119  // from being visible?
1120  if (isa<ClassTemplateSpecializationDecl>(D) || D->isTemplateParameter())
1121    return;
1122  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
1123    if (FD->isFunctionTemplateSpecialization())
1124      return;
1125
1126  DeclContext *PrimaryContext = getPrimaryContext();
1127  if (PrimaryContext != this) {
1128    PrimaryContext->makeDeclVisibleInContext(D, Recoverable);
1129    return;
1130  }
1131
1132  // If we already have a lookup data structure, perform the insertion
1133  // into it. If we haven't deserialized externally stored decls, deserialize
1134  // them so we can add the decl. Otherwise, be lazy and don't build that
1135  // structure until someone asks for it.
1136  if (LookupPtr || !Recoverable || hasExternalVisibleStorage())
1137    makeDeclVisibleInContextImpl(D);
1138
1139  // If we are a transparent context or inline namespace, insert into our
1140  // parent context, too. This operation is recursive.
1141  if (isTransparentContext() || isInlineNamespace())
1142    getParent()->makeDeclVisibleInContext(D, Recoverable);
1143
1144  Decl *DCAsDecl = cast<Decl>(this);
1145  // Notify that a decl was made visible unless it's a Tag being defined.
1146  if (!(isa<TagDecl>(DCAsDecl) && cast<TagDecl>(DCAsDecl)->isBeingDefined()))
1147    if (ASTMutationListener *L = DCAsDecl->getASTMutationListener())
1148      L->AddedVisibleDecl(this, D);
1149}
1150
1151void DeclContext::makeDeclVisibleInContextImpl(NamedDecl *D) {
1152  // Skip unnamed declarations.
1153  if (!D->getDeclName())
1154    return;
1155
1156  // FIXME: This feels like a hack. Should DeclarationName support
1157  // template-ids, or is there a better way to keep specializations
1158  // from being visible?
1159  if (isa<ClassTemplateSpecializationDecl>(D) || D->isTemplateParameter())
1160    return;
1161
1162  ASTContext *C = 0;
1163  if (!LookupPtr) {
1164    C = &getParentASTContext();
1165    CreateStoredDeclsMap(*C);
1166  }
1167
1168  // If there is an external AST source, load any declarations it knows about
1169  // with this declaration's name.
1170  // If the lookup table contains an entry about this name it means that we
1171  // have already checked the external source.
1172  if (ExternalASTSource *Source = getParentASTContext().getExternalSource())
1173    if (hasExternalVisibleStorage() &&
1174        LookupPtr->find(D->getDeclName()) == LookupPtr->end())
1175      Source->FindExternalVisibleDeclsByName(this, D->getDeclName());
1176
1177  // Insert this declaration into the map.
1178  StoredDeclsList &DeclNameEntries = (*LookupPtr)[D->getDeclName()];
1179  if (DeclNameEntries.isNull()) {
1180    DeclNameEntries.setOnlyValue(D);
1181    return;
1182  }
1183
1184  // If it is possible that this is a redeclaration, check to see if there is
1185  // already a decl for which declarationReplaces returns true.  If there is
1186  // one, just replace it and return.
1187  if (DeclNameEntries.HandleRedeclaration(D))
1188    return;
1189
1190  // Put this declaration into the appropriate slot.
1191  DeclNameEntries.AddSubsequentDecl(D);
1192}
1193
1194void DeclContext::MaterializeVisibleDeclsFromExternalStorage() {
1195  ExternalASTSource *Source = getParentASTContext().getExternalSource();
1196  assert(hasExternalVisibleStorage() && Source && "No external storage?");
1197
1198  if (!LookupPtr)
1199    CreateStoredDeclsMap(getParentASTContext());
1200  Source->MaterializeVisibleDecls(this);
1201}
1202
1203/// Returns iterator range [First, Last) of UsingDirectiveDecls stored within
1204/// this context.
1205DeclContext::udir_iterator_range
1206DeclContext::getUsingDirectives() const {
1207  lookup_const_result Result = lookup(UsingDirectiveDecl::getName());
1208  return udir_iterator_range(reinterpret_cast<udir_iterator>(Result.first),
1209                             reinterpret_cast<udir_iterator>(Result.second));
1210}
1211
1212//===----------------------------------------------------------------------===//
1213// Creation and Destruction of StoredDeclsMaps.                               //
1214//===----------------------------------------------------------------------===//
1215
1216StoredDeclsMap *DeclContext::CreateStoredDeclsMap(ASTContext &C) const {
1217  assert(!LookupPtr && "context already has a decls map");
1218  assert(getPrimaryContext() == this &&
1219         "creating decls map on non-primary context");
1220
1221  StoredDeclsMap *M;
1222  bool Dependent = isDependentContext();
1223  if (Dependent)
1224    M = new DependentStoredDeclsMap();
1225  else
1226    M = new StoredDeclsMap();
1227  M->Previous = C.LastSDM;
1228  C.LastSDM = llvm::PointerIntPair<StoredDeclsMap*,1>(M, Dependent);
1229  LookupPtr = M;
1230  return M;
1231}
1232
1233void ASTContext::ReleaseDeclContextMaps() {
1234  // It's okay to delete DependentStoredDeclsMaps via a StoredDeclsMap
1235  // pointer because the subclass doesn't add anything that needs to
1236  // be deleted.
1237  StoredDeclsMap::DestroyAll(LastSDM.getPointer(), LastSDM.getInt());
1238}
1239
1240void StoredDeclsMap::DestroyAll(StoredDeclsMap *Map, bool Dependent) {
1241  while (Map) {
1242    // Advance the iteration before we invalidate memory.
1243    llvm::PointerIntPair<StoredDeclsMap*,1> Next = Map->Previous;
1244
1245    if (Dependent)
1246      delete static_cast<DependentStoredDeclsMap*>(Map);
1247    else
1248      delete Map;
1249
1250    Map = Next.getPointer();
1251    Dependent = Next.getInt();
1252  }
1253}
1254
1255DependentDiagnostic *DependentDiagnostic::Create(ASTContext &C,
1256                                                 DeclContext *Parent,
1257                                           const PartialDiagnostic &PDiag) {
1258  assert(Parent->isDependentContext()
1259         && "cannot iterate dependent diagnostics of non-dependent context");
1260  Parent = Parent->getPrimaryContext();
1261  if (!Parent->LookupPtr)
1262    Parent->CreateStoredDeclsMap(C);
1263
1264  DependentStoredDeclsMap *Map
1265    = static_cast<DependentStoredDeclsMap*>(Parent->LookupPtr);
1266
1267  // Allocate the copy of the PartialDiagnostic via the ASTContext's
1268  // BumpPtrAllocator, rather than the ASTContext itself.
1269  PartialDiagnostic::Storage *DiagStorage = 0;
1270  if (PDiag.hasStorage())
1271    DiagStorage = new (C) PartialDiagnostic::Storage;
1272
1273  DependentDiagnostic *DD = new (C) DependentDiagnostic(PDiag, DiagStorage);
1274
1275  // TODO: Maybe we shouldn't reverse the order during insertion.
1276  DD->NextDiagnostic = Map->FirstDiagnostic;
1277  Map->FirstDiagnostic = DD;
1278
1279  return DD;
1280}
1281