DeclBase.cpp revision 8785d115ebaf1a850f5e581e4acd2dbfb2b843cb 
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>
33using namespace clang;
34
35//===----------------------------------------------------------------------===//
36//  Statistics
37//===----------------------------------------------------------------------===//
38
39#define DECL(DERIVED, BASE) static int n##DERIVED##s = 0;
40#define ABSTRACT_DECL(DECL)
41#include "clang/AST/DeclNodes.inc"
42
43static bool StatSwitch = false;
44
45const char *Decl::getDeclKindName() const {
46  switch (DeclKind) {
47  default: assert(0 && "Declaration not in DeclNodes.inc!");
48#define DECL(DERIVED, BASE) case DERIVED: return #DERIVED;
49#define ABSTRACT_DECL(DECL)
50#include "clang/AST/DeclNodes.inc"
51  }
52}
53
54void Decl::setInvalidDecl(bool Invalid) {
55  InvalidDecl = Invalid;
56  if (Invalid) {
57    // Defensive maneuver for ill-formed code: we're likely not to make it to
58    // a point where we set the access specifier, so default it to "public"
59    // to avoid triggering asserts elsewhere in the front end.
60    setAccess(AS_public);
61  }
62}
63
64const char *DeclContext::getDeclKindName() const {
65  switch (DeclKind) {
66  default: assert(0 && "Declaration context not in DeclNodes.inc!");
67#define DECL(DERIVED, BASE) case Decl::DERIVED: return #DERIVED;
68#define ABSTRACT_DECL(DECL)
69#include "clang/AST/DeclNodes.inc"
70  }
71}
72
73bool Decl::CollectingStats(bool Enable) {
74  if (Enable) StatSwitch = true;
75  return StatSwitch;
76}
77
78void Decl::PrintStats() {
79  fprintf(stderr, "*** Decl Stats:\n");
80
81  int totalDecls = 0;
82#define DECL(DERIVED, BASE) totalDecls += n##DERIVED##s;
83#define ABSTRACT_DECL(DECL)
84#include "clang/AST/DeclNodes.inc"
85  fprintf(stderr, "  %d decls total.\n", totalDecls);
86
87  int totalBytes = 0;
88#define DECL(DERIVED, BASE)                                             \
89  if (n##DERIVED##s > 0) {                                              \
90    totalBytes += (int)(n##DERIVED##s * sizeof(DERIVED##Decl));         \
91    fprintf(stderr, "    %d " #DERIVED " decls, %d each (%d bytes)\n",  \
92            n##DERIVED##s, (int)sizeof(DERIVED##Decl),                  \
93            (int)(n##DERIVED##s * sizeof(DERIVED##Decl)));              \
94  }
95#define ABSTRACT_DECL(DECL)
96#include "clang/AST/DeclNodes.inc"
97
98  fprintf(stderr, "Total bytes = %d\n", totalBytes);
99}
100
101void Decl::add(Kind k) {
102  switch (k) {
103  default: assert(0 && "Declaration not in DeclNodes.inc!");
104#define DECL(DERIVED, BASE) case DERIVED: ++n##DERIVED##s; break;
105#define ABSTRACT_DECL(DECL)
106#include "clang/AST/DeclNodes.inc"
107  }
108}
109
110bool Decl::isTemplateParameterPack() const {
111  if (const TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(this))
112    return TTP->isParameterPack();
113  if (const NonTypeTemplateParmDecl *NTTP
114                                = dyn_cast<NonTypeTemplateParmDecl>(this))
115    return NTTP->isParameterPack();
116  if (const TemplateTemplateParmDecl *TTP
117                                    = dyn_cast<TemplateTemplateParmDecl>(this))
118    return TTP->isParameterPack();
119  return false;
120}
121
122bool Decl::isParameterPack() const {
123  if (const ParmVarDecl *Parm = dyn_cast<ParmVarDecl>(this))
124    return Parm->isParameterPack();
125
126  return isTemplateParameterPack();
127}
128
129bool Decl::isFunctionOrFunctionTemplate() const {
130  if (const UsingShadowDecl *UD = dyn_cast<UsingShadowDecl>(this))
131    return UD->getTargetDecl()->isFunctionOrFunctionTemplate();
132
133  return isa<FunctionDecl>(this) || isa<FunctionTemplateDecl>(this);
134}
135
136bool Decl::isDefinedOutsideFunctionOrMethod() const {
137  for (const DeclContext *DC = getDeclContext();
138       DC && !DC->isTranslationUnit();
139       DC = DC->getParent())
140    if (DC->isFunctionOrMethod())
141      return false;
142
143  return true;
144}
145
146
147//===----------------------------------------------------------------------===//
148// PrettyStackTraceDecl Implementation
149//===----------------------------------------------------------------------===//
150
151void PrettyStackTraceDecl::print(llvm::raw_ostream &OS) const {
152  SourceLocation TheLoc = Loc;
153  if (TheLoc.isInvalid() && TheDecl)
154    TheLoc = TheDecl->getLocation();
155
156  if (TheLoc.isValid()) {
157    TheLoc.print(OS, SM);
158    OS << ": ";
159  }
160
161  OS << Message;
162
163  if (const NamedDecl *DN = dyn_cast_or_null<NamedDecl>(TheDecl))
164    OS << " '" << DN->getQualifiedNameAsString() << '\'';
165  OS << '\n';
166}
167
168//===----------------------------------------------------------------------===//
169// Decl Implementation
170//===----------------------------------------------------------------------===//
171
172// Out-of-line virtual method providing a home for Decl.
173Decl::~Decl() { }
174
175void Decl::setDeclContext(DeclContext *DC) {
176  DeclCtx = DC;
177}
178
179void Decl::setLexicalDeclContext(DeclContext *DC) {
180  if (DC == getLexicalDeclContext())
181    return;
182
183  if (isInSemaDC()) {
184    MultipleDC *MDC = new (getASTContext()) MultipleDC();
185    MDC->SemanticDC = getDeclContext();
186    MDC->LexicalDC = DC;
187    DeclCtx = MDC;
188  } else {
189    getMultipleDC()->LexicalDC = DC;
190  }
191}
192
193bool Decl::isInAnonymousNamespace() const {
194  const DeclContext *DC = getDeclContext();
195  do {
196    if (const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(DC))
197      if (ND->isAnonymousNamespace())
198        return true;
199  } while ((DC = DC->getParent()));
200
201  return false;
202}
203
204TranslationUnitDecl *Decl::getTranslationUnitDecl() {
205  if (TranslationUnitDecl *TUD = dyn_cast<TranslationUnitDecl>(this))
206    return TUD;
207
208  DeclContext *DC = getDeclContext();
209  assert(DC && "This decl is not contained in a translation unit!");
210
211  while (!DC->isTranslationUnit()) {
212    DC = DC->getParent();
213    assert(DC && "This decl is not contained in a translation unit!");
214  }
215
216  return cast<TranslationUnitDecl>(DC);
217}
218
219ASTContext &Decl::getASTContext() const {
220  return getTranslationUnitDecl()->getASTContext();
221}
222
223ASTMutationListener *Decl::getASTMutationListener() const {
224  return getASTContext().getASTMutationListener();
225}
226
227bool Decl::isUsed(bool CheckUsedAttr) const {
228  if (Used)
229    return true;
230
231  // Check for used attribute.
232  if (CheckUsedAttr && hasAttr<UsedAttr>())
233    return true;
234
235  // Check redeclarations for used attribute.
236  for (redecl_iterator I = redecls_begin(), E = redecls_end(); I != E; ++I) {
237    if ((CheckUsedAttr && I->hasAttr<UsedAttr>()) || I->Used)
238      return true;
239  }
240
241  return false;
242}
243
244bool Decl::isReferenced() const {
245  if (Referenced)
246    return true;
247
248  // Check redeclarations.
249  for (redecl_iterator I = redecls_begin(), E = redecls_end(); I != E; ++I)
250    if (I->Referenced)
251      return true;
252
253  return false;
254}
255
256/// \brief Determine the availability of the given declaration based on
257/// the target platform.
258///
259/// When it returns an availability result other than \c AR_Available,
260/// if the \p Message parameter is non-NULL, it will be set to a
261/// string describing why the entity is unavailable.
262///
263/// FIXME: Make these strings localizable, since they end up in
264/// diagnostics.
265static AvailabilityResult CheckAvailability(ASTContext &Context,
266                                            const AvailabilityAttr *A,
267                                            std::string *Message) {
268  llvm::StringRef TargetPlatform = Context.Target.getPlatformName();
269  llvm::StringRef PrettyPlatformName
270    = AvailabilityAttr::getPrettyPlatformName(TargetPlatform);
271  if (PrettyPlatformName.empty())
272    PrettyPlatformName = TargetPlatform;
273
274  VersionTuple TargetMinVersion = Context.Target.getPlatformMinVersion();
275  if (TargetMinVersion.empty())
276    return AR_Available;
277
278  // Match the platform name.
279  if (A->getPlatform()->getName() != TargetPlatform)
280    return AR_Available;
281
282  // Make sure that this declaration has not been marked 'unavailable'.
283  if (A->getUnavailable()) {
284    if (Message) {
285      Message->clear();
286      llvm::raw_string_ostream Out(*Message);
287      Out << "not available on " << PrettyPlatformName;
288    }
289
290    return AR_Unavailable;
291  }
292
293  // Make sure that this declaration has already been introduced.
294  if (!A->getIntroduced().empty() &&
295      TargetMinVersion < A->getIntroduced()) {
296    if (Message) {
297      Message->clear();
298      llvm::raw_string_ostream Out(*Message);
299      Out << "introduced in " << PrettyPlatformName << ' '
300          << A->getIntroduced();
301    }
302
303    return AR_NotYetIntroduced;
304  }
305
306  // Make sure that this declaration hasn't been obsoleted.
307  if (!A->getObsoleted().empty() && TargetMinVersion >= A->getObsoleted()) {
308    if (Message) {
309      Message->clear();
310      llvm::raw_string_ostream Out(*Message);
311      Out << "obsoleted in " << PrettyPlatformName << ' '
312          << A->getObsoleted();
313    }
314
315    return AR_Unavailable;
316  }
317
318  // Make sure that this declaration hasn't been deprecated.
319  if (!A->getDeprecated().empty() && TargetMinVersion >= A->getDeprecated()) {
320    if (Message) {
321      Message->clear();
322      llvm::raw_string_ostream Out(*Message);
323      Out << "first deprecated in " << PrettyPlatformName << ' '
324          << A->getDeprecated();
325    }
326
327    return AR_Deprecated;
328  }
329
330  return AR_Available;
331}
332
333AvailabilityResult Decl::getAvailability(std::string *Message) const {
334  AvailabilityResult Result = AR_Available;
335  std::string ResultMessage;
336
337  for (attr_iterator A = attr_begin(), AEnd = attr_end(); A != AEnd; ++A) {
338    if (DeprecatedAttr *Deprecated = dyn_cast<DeprecatedAttr>(*A)) {
339      if (Result >= AR_Deprecated)
340        continue;
341
342      if (Message)
343        ResultMessage = Deprecated->getMessage();
344
345      Result = AR_Deprecated;
346      continue;
347    }
348
349    if (UnavailableAttr *Unavailable = dyn_cast<UnavailableAttr>(*A)) {
350      if (Message)
351        *Message = Unavailable->getMessage();
352      return AR_Unavailable;
353    }
354
355    if (AvailabilityAttr *Availability = dyn_cast<AvailabilityAttr>(*A)) {
356      AvailabilityResult AR = CheckAvailability(getASTContext(), Availability,
357                                                Message);
358
359      if (AR == AR_Unavailable)
360        return AR_Unavailable;
361
362      if (AR > Result) {
363        Result = AR;
364        if (Message)
365          ResultMessage.swap(*Message);
366      }
367      continue;
368    }
369  }
370
371  if (Message)
372    Message->swap(ResultMessage);
373  return Result;
374}
375
376bool Decl::canBeWeakImported(bool &IsDefinition) const {
377  IsDefinition = false;
378  if (const VarDecl *Var = dyn_cast<VarDecl>(this)) {
379    if (!Var->hasExternalStorage() || Var->getInit()) {
380      IsDefinition = true;
381      return false;
382    }
383  } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(this)) {
384    if (FD->hasBody()) {
385      IsDefinition = true;
386      return false;
387    }
388  } else if (isa<ObjCPropertyDecl>(this) || isa<ObjCMethodDecl>(this))
389    return false;
390  else if (!(getASTContext().getLangOptions().ObjCNonFragileABI &&
391             isa<ObjCInterfaceDecl>(this)))
392    return false;
393
394  return true;
395}
396
397bool Decl::isWeakImported() const {
398  bool IsDefinition;
399  if (!canBeWeakImported(IsDefinition))
400    return false;
401
402  for (attr_iterator A = attr_begin(), AEnd = attr_end(); A != AEnd; ++A) {
403    if (isa<WeakImportAttr>(*A))
404      return true;
405
406    if (AvailabilityAttr *Availability = dyn_cast<AvailabilityAttr>(*A)) {
407      if (CheckAvailability(getASTContext(), Availability, 0)
408                                                         == AR_NotYetIntroduced)
409        return true;
410    }
411  }
412
413  return false;
414}
415
416unsigned Decl::getIdentifierNamespaceForKind(Kind DeclKind) {
417  switch (DeclKind) {
418    case Function:
419    case CXXMethod:
420    case CXXConstructor:
421    case CXXDestructor:
422    case CXXConversion:
423    case EnumConstant:
424    case Var:
425    case ImplicitParam:
426    case ParmVar:
427    case NonTypeTemplateParm:
428    case ObjCMethod:
429    case ObjCProperty:
430      return IDNS_Ordinary;
431    case Label:
432      return IDNS_Label;
433    case IndirectField:
434      return IDNS_Ordinary | IDNS_Member;
435
436    case ObjCCompatibleAlias:
437    case ObjCInterface:
438      return IDNS_Ordinary | IDNS_Type;
439
440    case Typedef:
441    case TypeAlias:
442    case TypeAliasTemplate:
443    case UnresolvedUsingTypename:
444    case TemplateTypeParm:
445      return IDNS_Ordinary | IDNS_Type;
446
447    case UsingShadow:
448      return 0; // we'll actually overwrite this later
449
450    case UnresolvedUsingValue:
451      return IDNS_Ordinary | IDNS_Using;
452
453    case Using:
454      return IDNS_Using;
455
456    case ObjCProtocol:
457      return IDNS_ObjCProtocol;
458
459    case Field:
460    case ObjCAtDefsField:
461    case ObjCIvar:
462      return IDNS_Member;
463
464    case Record:
465    case CXXRecord:
466    case Enum:
467      return IDNS_Tag | IDNS_Type;
468
469    case Namespace:
470    case NamespaceAlias:
471      return IDNS_Namespace;
472
473    case FunctionTemplate:
474      return IDNS_Ordinary;
475
476    case ClassTemplate:
477    case TemplateTemplateParm:
478      return IDNS_Ordinary | IDNS_Tag | IDNS_Type;
479
480    // Never have names.
481    case Friend:
482    case FriendTemplate:
483    case AccessSpec:
484    case LinkageSpec:
485    case FileScopeAsm:
486    case StaticAssert:
487    case ObjCClass:
488    case ObjCPropertyImpl:
489    case ObjCForwardProtocol:
490    case Block:
491    case TranslationUnit:
492
493    case UsingDirective:
494    case ClassTemplateSpecialization:
495    case ClassTemplatePartialSpecialization:
496    case ObjCImplementation:
497    case ObjCCategory:
498    case ObjCCategoryImpl:
499      // Never looked up by name.
500      return 0;
501  }
502
503  return 0;
504}
505
506void Decl::setAttrs(const AttrVec &attrs) {
507  assert(!HasAttrs && "Decl already contains attrs.");
508
509  AttrVec &AttrBlank = getASTContext().getDeclAttrs(this);
510  assert(AttrBlank.empty() && "HasAttrs was wrong?");
511
512  AttrBlank = attrs;
513  HasAttrs = true;
514}
515
516void Decl::dropAttrs() {
517  if (!HasAttrs) return;
518
519  HasAttrs = false;
520  getASTContext().eraseDeclAttrs(this);
521}
522
523void Decl::dropWeakImportAttr() {
524  if (!HasAttrs) return;
525  AttrVec &Attrs = getASTContext().getDeclAttrs(this);
526  for (llvm::SmallVectorImpl<Attr*>::iterator A = Attrs.begin();
527       A != Attrs.end(); ++A) {
528    if (isa<WeakImportAttr>(*A)) {
529      Attrs.erase(A);
530      break;
531    }
532  }
533  if (Attrs.empty())
534    HasAttrs = false;
535}
536
537const AttrVec &Decl::getAttrs() const {
538  assert(HasAttrs && "No attrs to get!");
539  return getASTContext().getDeclAttrs(this);
540}
541
542void Decl::swapAttrs(Decl *RHS) {
543  bool HasLHSAttr = this->HasAttrs;
544  bool HasRHSAttr = RHS->HasAttrs;
545
546  // Usually, neither decl has attrs, nothing to do.
547  if (!HasLHSAttr && !HasRHSAttr) return;
548
549  // If 'this' has no attrs, swap the other way.
550  if (!HasLHSAttr)
551    return RHS->swapAttrs(this);
552
553  ASTContext &Context = getASTContext();
554
555  // Handle the case when both decls have attrs.
556  if (HasRHSAttr) {
557    std::swap(Context.getDeclAttrs(this), Context.getDeclAttrs(RHS));
558    return;
559  }
560
561  // Otherwise, LHS has an attr and RHS doesn't.
562  Context.getDeclAttrs(RHS) = Context.getDeclAttrs(this);
563  Context.eraseDeclAttrs(this);
564  this->HasAttrs = false;
565  RHS->HasAttrs = true;
566}
567
568Decl *Decl::castFromDeclContext (const DeclContext *D) {
569  Decl::Kind DK = D->getDeclKind();
570  switch(DK) {
571#define DECL(NAME, BASE)
572#define DECL_CONTEXT(NAME) \
573    case Decl::NAME:       \
574      return static_cast<NAME##Decl*>(const_cast<DeclContext*>(D));
575#define DECL_CONTEXT_BASE(NAME)
576#include "clang/AST/DeclNodes.inc"
577    default:
578#define DECL(NAME, BASE)
579#define DECL_CONTEXT_BASE(NAME)                  \
580      if (DK >= first##NAME && DK <= last##NAME) \
581        return static_cast<NAME##Decl*>(const_cast<DeclContext*>(D));
582#include "clang/AST/DeclNodes.inc"
583      assert(false && "a decl that inherits DeclContext isn't handled");
584      return 0;
585  }
586}
587
588DeclContext *Decl::castToDeclContext(const Decl *D) {
589  Decl::Kind DK = D->getKind();
590  switch(DK) {
591#define DECL(NAME, BASE)
592#define DECL_CONTEXT(NAME) \
593    case Decl::NAME:       \
594      return static_cast<NAME##Decl*>(const_cast<Decl*>(D));
595#define DECL_CONTEXT_BASE(NAME)
596#include "clang/AST/DeclNodes.inc"
597    default:
598#define DECL(NAME, BASE)
599#define DECL_CONTEXT_BASE(NAME)                                   \
600      if (DK >= first##NAME && DK <= last##NAME)                  \
601        return static_cast<NAME##Decl*>(const_cast<Decl*>(D));
602#include "clang/AST/DeclNodes.inc"
603      assert(false && "a decl that inherits DeclContext isn't handled");
604      return 0;
605  }
606}
607
608SourceLocation Decl::getBodyRBrace() const {
609  // Special handling of FunctionDecl to avoid de-serializing the body from PCH.
610  // FunctionDecl stores EndRangeLoc for this purpose.
611  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(this)) {
612    const FunctionDecl *Definition;
613    if (FD->hasBody(Definition))
614      return Definition->getSourceRange().getEnd();
615    return SourceLocation();
616  }
617
618  if (Stmt *Body = getBody())
619    return Body->getSourceRange().getEnd();
620
621  return SourceLocation();
622}
623
624void Decl::CheckAccessDeclContext() const {
625#ifndef NDEBUG
626  // Suppress this check if any of the following hold:
627  // 1. this is the translation unit (and thus has no parent)
628  // 2. this is a template parameter (and thus doesn't belong to its context)
629  // 3. this is a non-type template parameter
630  // 4. the context is not a record
631  // 5. it's invalid
632  // 6. it's a C++0x static_assert.
633  if (isa<TranslationUnitDecl>(this) ||
634      isa<TemplateTypeParmDecl>(this) ||
635      isa<NonTypeTemplateParmDecl>(this) ||
636      !isa<CXXRecordDecl>(getDeclContext()) ||
637      isInvalidDecl() ||
638      isa<StaticAssertDecl>(this) ||
639      // FIXME: a ParmVarDecl can have ClassTemplateSpecialization
640      // as DeclContext (?).
641      isa<ParmVarDecl>(this) ||
642      // FIXME: a ClassTemplateSpecialization or CXXRecordDecl can have
643      // AS_none as access specifier.
644      isa<CXXRecordDecl>(this))
645    return;
646
647  assert(Access != AS_none &&
648         "Access specifier is AS_none inside a record decl");
649#endif
650}
651
652DeclContext *Decl::getNonClosureContext() {
653  DeclContext *DC = getDeclContext();
654
655  // This is basically "while (DC->isClosure()) DC = DC->getParent();"
656  // except that it's significantly more efficient to cast to a known
657  // decl type and call getDeclContext() than to call getParent().
658  do {
659    if (isa<BlockDecl>(DC)) {
660      DC = cast<BlockDecl>(DC)->getDeclContext();
661      continue;
662    }
663  } while (false);
664
665  assert(!DC->isClosure());
666  return DC;
667}
668
669//===----------------------------------------------------------------------===//
670// DeclContext Implementation
671//===----------------------------------------------------------------------===//
672
673bool DeclContext::classof(const Decl *D) {
674  switch (D->getKind()) {
675#define DECL(NAME, BASE)
676#define DECL_CONTEXT(NAME) case Decl::NAME:
677#define DECL_CONTEXT_BASE(NAME)
678#include "clang/AST/DeclNodes.inc"
679      return true;
680    default:
681#define DECL(NAME, BASE)
682#define DECL_CONTEXT_BASE(NAME)                 \
683      if (D->getKind() >= Decl::first##NAME &&  \
684          D->getKind() <= Decl::last##NAME)     \
685        return true;
686#include "clang/AST/DeclNodes.inc"
687      return false;
688  }
689}
690
691DeclContext::~DeclContext() { }
692
693/// \brief Find the parent context of this context that will be
694/// used for unqualified name lookup.
695///
696/// Generally, the parent lookup context is the semantic context. However, for
697/// a friend function the parent lookup context is the lexical context, which
698/// is the class in which the friend is declared.
699DeclContext *DeclContext::getLookupParent() {
700  // FIXME: Find a better way to identify friends
701  if (isa<FunctionDecl>(this))
702    if (getParent()->getRedeclContext()->isFileContext() &&
703        getLexicalParent()->getRedeclContext()->isRecord())
704      return getLexicalParent();
705
706  return getParent();
707}
708
709bool DeclContext::isInlineNamespace() const {
710  return isNamespace() &&
711         cast<NamespaceDecl>(this)->isInline();
712}
713
714bool DeclContext::isDependentContext() const {
715  if (isFileContext())
716    return false;
717
718  if (isa<ClassTemplatePartialSpecializationDecl>(this))
719    return true;
720
721  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(this))
722    if (Record->getDescribedClassTemplate())
723      return true;
724
725  if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(this)) {
726    if (Function->getDescribedFunctionTemplate())
727      return true;
728
729    // Friend function declarations are dependent if their *lexical*
730    // context is dependent.
731    if (cast<Decl>(this)->getFriendObjectKind())
732      return getLexicalParent()->isDependentContext();
733  }
734
735  return getParent() && getParent()->isDependentContext();
736}
737
738bool DeclContext::isTransparentContext() const {
739  if (DeclKind == Decl::Enum)
740    return !cast<EnumDecl>(this)->isScoped();
741  else if (DeclKind == Decl::LinkageSpec)
742    return true;
743
744  return false;
745}
746
747bool DeclContext::isExternCContext() const {
748  const DeclContext *DC = this;
749  while (DC->DeclKind != Decl::TranslationUnit) {
750    if (DC->DeclKind == Decl::LinkageSpec)
751      return cast<LinkageSpecDecl>(DC)->getLanguage()
752        == LinkageSpecDecl::lang_c;
753    DC = DC->getParent();
754  }
755  return false;
756}
757
758bool DeclContext::Encloses(const DeclContext *DC) const {
759  if (getPrimaryContext() != this)
760    return getPrimaryContext()->Encloses(DC);
761
762  for (; DC; DC = DC->getParent())
763    if (DC->getPrimaryContext() == this)
764      return true;
765  return false;
766}
767
768DeclContext *DeclContext::getPrimaryContext() {
769  switch (DeclKind) {
770  case Decl::TranslationUnit:
771  case Decl::LinkageSpec:
772  case Decl::Block:
773    // There is only one DeclContext for these entities.
774    return this;
775
776  case Decl::Namespace:
777    // The original namespace is our primary context.
778    return static_cast<NamespaceDecl*>(this)->getOriginalNamespace();
779
780  case Decl::ObjCMethod:
781    return this;
782
783  case Decl::ObjCInterface:
784  case Decl::ObjCProtocol:
785  case Decl::ObjCCategory:
786    // FIXME: Can Objective-C interfaces be forward-declared?
787    return this;
788
789  case Decl::ObjCImplementation:
790  case Decl::ObjCCategoryImpl:
791    return this;
792
793  default:
794    if (DeclKind >= Decl::firstTag && DeclKind <= Decl::lastTag) {
795      // If this is a tag type that has a definition or is currently
796      // being defined, that definition is our primary context.
797      TagDecl *Tag = cast<TagDecl>(this);
798      assert(isa<TagType>(Tag->TypeForDecl) ||
799             isa<InjectedClassNameType>(Tag->TypeForDecl));
800
801      if (TagDecl *Def = Tag->getDefinition())
802        return Def;
803
804      if (!isa<InjectedClassNameType>(Tag->TypeForDecl)) {
805        const TagType *TagTy = cast<TagType>(Tag->TypeForDecl);
806        if (TagTy->isBeingDefined())
807          // FIXME: is it necessarily being defined in the decl
808          // that owns the type?
809          return TagTy->getDecl();
810      }
811
812      return Tag;
813    }
814
815    assert(DeclKind >= Decl::firstFunction && DeclKind <= Decl::lastFunction &&
816          "Unknown DeclContext kind");
817    return this;
818  }
819}
820
821DeclContext *DeclContext::getNextContext() {
822  switch (DeclKind) {
823  case Decl::Namespace:
824    // Return the next namespace
825    return static_cast<NamespaceDecl*>(this)->getNextNamespace();
826
827  default:
828    return 0;
829  }
830}
831
832std::pair<Decl *, Decl *>
833DeclContext::BuildDeclChain(const llvm::SmallVectorImpl<Decl*> &Decls) {
834  // Build up a chain of declarations via the Decl::NextDeclInContext field.
835  Decl *FirstNewDecl = 0;
836  Decl *PrevDecl = 0;
837  for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
838    Decl *D = Decls[I];
839    if (PrevDecl)
840      PrevDecl->NextDeclInContext = D;
841    else
842      FirstNewDecl = D;
843
844    PrevDecl = D;
845  }
846
847  return std::make_pair(FirstNewDecl, PrevDecl);
848}
849
850/// \brief Load the declarations within this lexical storage from an
851/// external source.
852void
853DeclContext::LoadLexicalDeclsFromExternalStorage() const {
854  ExternalASTSource *Source = getParentASTContext().getExternalSource();
855  assert(hasExternalLexicalStorage() && Source && "No external storage?");
856
857  // Notify that we have a DeclContext that is initializing.
858  ExternalASTSource::Deserializing ADeclContext(Source);
859
860  llvm::SmallVector<Decl*, 64> Decls;
861  if (Source->FindExternalLexicalDecls(this, Decls))
862    return;
863
864  // There is no longer any lexical storage in this context
865  ExternalLexicalStorage = false;
866
867  if (Decls.empty())
868    return;
869
870  // We may have already loaded just the fields of this record, in which case
871  // don't add the decls, just replace the FirstDecl/LastDecl chain.
872  if (const RecordDecl *RD = dyn_cast<RecordDecl>(this))
873    if (RD->LoadedFieldsFromExternalStorage) {
874      llvm::tie(FirstDecl, LastDecl) = BuildDeclChain(Decls);
875      return;
876    }
877
878  // Splice the newly-read declarations into the beginning of the list
879  // of declarations.
880  Decl *ExternalFirst, *ExternalLast;
881  llvm::tie(ExternalFirst, ExternalLast) = BuildDeclChain(Decls);
882  ExternalLast->NextDeclInContext = FirstDecl;
883  FirstDecl = ExternalFirst;
884  if (!LastDecl)
885    LastDecl = ExternalLast;
886}
887
888DeclContext::lookup_result
889ExternalASTSource::SetNoExternalVisibleDeclsForName(const DeclContext *DC,
890                                                    DeclarationName Name) {
891  ASTContext &Context = DC->getParentASTContext();
892  StoredDeclsMap *Map;
893  if (!(Map = DC->LookupPtr))
894    Map = DC->CreateStoredDeclsMap(Context);
895
896  StoredDeclsList &List = (*Map)[Name];
897  assert(List.isNull());
898  (void) List;
899
900  return DeclContext::lookup_result();
901}
902
903DeclContext::lookup_result
904ExternalASTSource::SetExternalVisibleDeclsForName(const DeclContext *DC,
905                                                  DeclarationName Name,
906                                    llvm::SmallVectorImpl<NamedDecl*> &Decls) {
907  ASTContext &Context = DC->getParentASTContext();;
908
909  StoredDeclsMap *Map;
910  if (!(Map = DC->LookupPtr))
911    Map = DC->CreateStoredDeclsMap(Context);
912
913  StoredDeclsList &List = (*Map)[Name];
914  for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
915    if (List.isNull())
916      List.setOnlyValue(Decls[I]);
917    else
918      List.AddSubsequentDecl(Decls[I]);
919  }
920
921  return List.getLookupResult();
922}
923
924void ExternalASTSource::MaterializeVisibleDeclsForName(const DeclContext *DC,
925                                                       DeclarationName Name,
926                                     llvm::SmallVectorImpl<NamedDecl*> &Decls) {
927  assert(DC->LookupPtr);
928  StoredDeclsMap &Map = *DC->LookupPtr;
929
930  // If there's an entry in the table the visible decls for this name have
931  // already been deserialized.
932  if (Map.find(Name) == Map.end()) {
933    StoredDeclsList &List = Map[Name];
934    for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
935      if (List.isNull())
936        List.setOnlyValue(Decls[I]);
937      else
938        List.AddSubsequentDecl(Decls[I]);
939    }
940  }
941}
942
943DeclContext::decl_iterator DeclContext::noload_decls_begin() const {
944  return decl_iterator(FirstDecl);
945}
946
947DeclContext::decl_iterator DeclContext::noload_decls_end() const {
948  return decl_iterator();
949}
950
951DeclContext::decl_iterator DeclContext::decls_begin() const {
952  if (hasExternalLexicalStorage())
953    LoadLexicalDeclsFromExternalStorage();
954
955  // FIXME: Check whether we need to load some declarations from
956  // external storage.
957  return decl_iterator(FirstDecl);
958}
959
960DeclContext::decl_iterator DeclContext::decls_end() const {
961  if (hasExternalLexicalStorage())
962    LoadLexicalDeclsFromExternalStorage();
963
964  return decl_iterator();
965}
966
967bool DeclContext::decls_empty() const {
968  if (hasExternalLexicalStorage())
969    LoadLexicalDeclsFromExternalStorage();
970
971  return !FirstDecl;
972}
973
974void DeclContext::removeDecl(Decl *D) {
975  assert(D->getLexicalDeclContext() == this &&
976         "decl being removed from non-lexical context");
977  assert((D->NextDeclInContext || D == LastDecl) &&
978         "decl is not in decls list");
979
980  // Remove D from the decl chain.  This is O(n) but hopefully rare.
981  if (D == FirstDecl) {
982    if (D == LastDecl)
983      FirstDecl = LastDecl = 0;
984    else
985      FirstDecl = D->NextDeclInContext;
986  } else {
987    for (Decl *I = FirstDecl; true; I = I->NextDeclInContext) {
988      assert(I && "decl not found in linked list");
989      if (I->NextDeclInContext == D) {
990        I->NextDeclInContext = D->NextDeclInContext;
991        if (D == LastDecl) LastDecl = I;
992        break;
993      }
994    }
995  }
996
997  // Mark that D is no longer in the decl chain.
998  D->NextDeclInContext = 0;
999
1000  // Remove D from the lookup table if necessary.
1001  if (isa<NamedDecl>(D)) {
1002    NamedDecl *ND = cast<NamedDecl>(D);
1003
1004    StoredDeclsMap *Map = getPrimaryContext()->LookupPtr;
1005    if (!Map) return;
1006
1007    StoredDeclsMap::iterator Pos = Map->find(ND->getDeclName());
1008    assert(Pos != Map->end() && "no lookup entry for decl");
1009    Pos->second.remove(ND);
1010  }
1011}
1012
1013void DeclContext::addHiddenDecl(Decl *D) {
1014  assert(D->getLexicalDeclContext() == this &&
1015         "Decl inserted into wrong lexical context");
1016  assert(!D->getNextDeclInContext() && D != LastDecl &&
1017         "Decl already inserted into a DeclContext");
1018
1019  if (FirstDecl) {
1020    LastDecl->NextDeclInContext = D;
1021    LastDecl = D;
1022  } else {
1023    FirstDecl = LastDecl = D;
1024  }
1025
1026  // Notify a C++ record declaration that we've added a member, so it can
1027  // update it's class-specific state.
1028  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(this))
1029    Record->addedMember(D);
1030}
1031
1032void DeclContext::addDecl(Decl *D) {
1033  addHiddenDecl(D);
1034
1035  if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
1036    ND->getDeclContext()->makeDeclVisibleInContext(ND);
1037}
1038
1039/// buildLookup - Build the lookup data structure with all of the
1040/// declarations in DCtx (and any other contexts linked to it or
1041/// transparent contexts nested within it).
1042void DeclContext::buildLookup(DeclContext *DCtx) {
1043  for (; DCtx; DCtx = DCtx->getNextContext()) {
1044    for (decl_iterator D = DCtx->decls_begin(),
1045                    DEnd = DCtx->decls_end();
1046         D != DEnd; ++D) {
1047      // Insert this declaration into the lookup structure, but only
1048      // if it's semantically in its decl context.  During non-lazy
1049      // lookup building, this is implicitly enforced by addDecl.
1050      if (NamedDecl *ND = dyn_cast<NamedDecl>(*D))
1051        if (D->getDeclContext() == DCtx)
1052          makeDeclVisibleInContextImpl(ND);
1053
1054      // Insert any forward-declared Objective-C interfaces into the lookup
1055      // data structure.
1056      if (ObjCClassDecl *Class = dyn_cast<ObjCClassDecl>(*D))
1057        for (ObjCClassDecl::iterator I = Class->begin(), IEnd = Class->end();
1058             I != IEnd; ++I)
1059          makeDeclVisibleInContextImpl(I->getInterface());
1060
1061      // If this declaration is itself a transparent declaration context or
1062      // inline namespace, add its members (recursively).
1063      if (DeclContext *InnerCtx = dyn_cast<DeclContext>(*D))
1064        if (InnerCtx->isTransparentContext() || InnerCtx->isInlineNamespace())
1065          buildLookup(InnerCtx->getPrimaryContext());
1066    }
1067  }
1068}
1069
1070DeclContext::lookup_result
1071DeclContext::lookup(DeclarationName Name) {
1072  DeclContext *PrimaryContext = getPrimaryContext();
1073  if (PrimaryContext != this)
1074    return PrimaryContext->lookup(Name);
1075
1076  if (hasExternalVisibleStorage()) {
1077    // Check to see if we've already cached the lookup results.
1078    if (LookupPtr) {
1079      StoredDeclsMap::iterator I = LookupPtr->find(Name);
1080      if (I != LookupPtr->end())
1081        return I->second.getLookupResult();
1082    }
1083
1084    ExternalASTSource *Source = getParentASTContext().getExternalSource();
1085    return Source->FindExternalVisibleDeclsByName(this, Name);
1086  }
1087
1088  /// If there is no lookup data structure, build one now by walking
1089  /// all of the linked DeclContexts (in declaration order!) and
1090  /// inserting their values.
1091  if (!LookupPtr) {
1092    buildLookup(this);
1093
1094    if (!LookupPtr)
1095      return lookup_result(lookup_iterator(0), lookup_iterator(0));
1096  }
1097
1098  StoredDeclsMap::iterator Pos = LookupPtr->find(Name);
1099  if (Pos == LookupPtr->end())
1100    return lookup_result(lookup_iterator(0), lookup_iterator(0));
1101  return Pos->second.getLookupResult();
1102}
1103
1104DeclContext::lookup_const_result
1105DeclContext::lookup(DeclarationName Name) const {
1106  return const_cast<DeclContext*>(this)->lookup(Name);
1107}
1108
1109DeclContext *DeclContext::getRedeclContext() {
1110  DeclContext *Ctx = this;
1111  // Skip through transparent contexts.
1112  while (Ctx->isTransparentContext())
1113    Ctx = Ctx->getParent();
1114  return Ctx;
1115}
1116
1117DeclContext *DeclContext::getEnclosingNamespaceContext() {
1118  DeclContext *Ctx = this;
1119  // Skip through non-namespace, non-translation-unit contexts.
1120  while (!Ctx->isFileContext())
1121    Ctx = Ctx->getParent();
1122  return Ctx->getPrimaryContext();
1123}
1124
1125bool DeclContext::InEnclosingNamespaceSetOf(const DeclContext *O) const {
1126  // For non-file contexts, this is equivalent to Equals.
1127  if (!isFileContext())
1128    return O->Equals(this);
1129
1130  do {
1131    if (O->Equals(this))
1132      return true;
1133
1134    const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(O);
1135    if (!NS || !NS->isInline())
1136      break;
1137    O = NS->getParent();
1138  } while (O);
1139
1140  return false;
1141}
1142
1143void DeclContext::makeDeclVisibleInContext(NamedDecl *D, bool Recoverable) {
1144  // FIXME: This feels like a hack. Should DeclarationName support
1145  // template-ids, or is there a better way to keep specializations
1146  // from being visible?
1147  if (isa<ClassTemplateSpecializationDecl>(D) || D->isTemplateParameter())
1148    return;
1149  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
1150    if (FD->isFunctionTemplateSpecialization())
1151      return;
1152
1153  DeclContext *PrimaryContext = getPrimaryContext();
1154  if (PrimaryContext != this) {
1155    PrimaryContext->makeDeclVisibleInContext(D, Recoverable);
1156    return;
1157  }
1158
1159  // If we already have a lookup data structure, perform the insertion
1160  // into it. If we haven't deserialized externally stored decls, deserialize
1161  // them so we can add the decl. Otherwise, be lazy and don't build that
1162  // structure until someone asks for it.
1163  if (LookupPtr || !Recoverable || hasExternalVisibleStorage())
1164    makeDeclVisibleInContextImpl(D);
1165
1166  // If we are a transparent context or inline namespace, insert into our
1167  // parent context, too. This operation is recursive.
1168  if (isTransparentContext() || isInlineNamespace())
1169    getParent()->makeDeclVisibleInContext(D, Recoverable);
1170
1171  Decl *DCAsDecl = cast<Decl>(this);
1172  // Notify that a decl was made visible unless it's a Tag being defined.
1173  if (!(isa<TagDecl>(DCAsDecl) && cast<TagDecl>(DCAsDecl)->isBeingDefined()))
1174    if (ASTMutationListener *L = DCAsDecl->getASTMutationListener())
1175      L->AddedVisibleDecl(this, D);
1176}
1177
1178void DeclContext::makeDeclVisibleInContextImpl(NamedDecl *D) {
1179  // Skip unnamed declarations.
1180  if (!D->getDeclName())
1181    return;
1182
1183  // Skip entities that can't be found by name lookup into a particular
1184  // context.
1185  if ((D->getIdentifierNamespace() == 0 && !isa<UsingDirectiveDecl>(D)) ||
1186      D->isTemplateParameter())
1187    return;
1188
1189  ASTContext *C = 0;
1190  if (!LookupPtr) {
1191    C = &getParentASTContext();
1192    CreateStoredDeclsMap(*C);
1193  }
1194
1195  // If there is an external AST source, load any declarations it knows about
1196  // with this declaration's name.
1197  // If the lookup table contains an entry about this name it means that we
1198  // have already checked the external source.
1199  if (ExternalASTSource *Source = getParentASTContext().getExternalSource())
1200    if (hasExternalVisibleStorage() &&
1201        LookupPtr->find(D->getDeclName()) == LookupPtr->end())
1202      Source->FindExternalVisibleDeclsByName(this, D->getDeclName());
1203
1204  // Insert this declaration into the map.
1205  StoredDeclsList &DeclNameEntries = (*LookupPtr)[D->getDeclName()];
1206  if (DeclNameEntries.isNull()) {
1207    DeclNameEntries.setOnlyValue(D);
1208    return;
1209  }
1210
1211  // If it is possible that this is a redeclaration, check to see if there is
1212  // already a decl for which declarationReplaces returns true.  If there is
1213  // one, just replace it and return.
1214  if (DeclNameEntries.HandleRedeclaration(D))
1215    return;
1216
1217  // Put this declaration into the appropriate slot.
1218  DeclNameEntries.AddSubsequentDecl(D);
1219}
1220
1221void DeclContext::MaterializeVisibleDeclsFromExternalStorage() {
1222  ExternalASTSource *Source = getParentASTContext().getExternalSource();
1223  assert(hasExternalVisibleStorage() && Source && "No external storage?");
1224
1225  if (!LookupPtr)
1226    CreateStoredDeclsMap(getParentASTContext());
1227  Source->MaterializeVisibleDecls(this);
1228}
1229
1230/// Returns iterator range [First, Last) of UsingDirectiveDecls stored within
1231/// this context.
1232DeclContext::udir_iterator_range
1233DeclContext::getUsingDirectives() const {
1234  lookup_const_result Result = lookup(UsingDirectiveDecl::getName());
1235  return udir_iterator_range(reinterpret_cast<udir_iterator>(Result.first),
1236                             reinterpret_cast<udir_iterator>(Result.second));
1237}
1238
1239//===----------------------------------------------------------------------===//
1240// Creation and Destruction of StoredDeclsMaps.                               //
1241//===----------------------------------------------------------------------===//
1242
1243StoredDeclsMap *DeclContext::CreateStoredDeclsMap(ASTContext &C) const {
1244  assert(!LookupPtr && "context already has a decls map");
1245  assert(getPrimaryContext() == this &&
1246         "creating decls map on non-primary context");
1247
1248  StoredDeclsMap *M;
1249  bool Dependent = isDependentContext();
1250  if (Dependent)
1251    M = new DependentStoredDeclsMap();
1252  else
1253    M = new StoredDeclsMap();
1254  M->Previous = C.LastSDM;
1255  C.LastSDM = llvm::PointerIntPair<StoredDeclsMap*,1>(M, Dependent);
1256  LookupPtr = M;
1257  return M;
1258}
1259
1260void ASTContext::ReleaseDeclContextMaps() {
1261  // It's okay to delete DependentStoredDeclsMaps via a StoredDeclsMap
1262  // pointer because the subclass doesn't add anything that needs to
1263  // be deleted.
1264  StoredDeclsMap::DestroyAll(LastSDM.getPointer(), LastSDM.getInt());
1265}
1266
1267void StoredDeclsMap::DestroyAll(StoredDeclsMap *Map, bool Dependent) {
1268  while (Map) {
1269    // Advance the iteration before we invalidate memory.
1270    llvm::PointerIntPair<StoredDeclsMap*,1> Next = Map->Previous;
1271
1272    if (Dependent)
1273      delete static_cast<DependentStoredDeclsMap*>(Map);
1274    else
1275      delete Map;
1276
1277    Map = Next.getPointer();
1278    Dependent = Next.getInt();
1279  }
1280}
1281
1282DependentDiagnostic *DependentDiagnostic::Create(ASTContext &C,
1283                                                 DeclContext *Parent,
1284                                           const PartialDiagnostic &PDiag) {
1285  assert(Parent->isDependentContext()
1286         && "cannot iterate dependent diagnostics of non-dependent context");
1287  Parent = Parent->getPrimaryContext();
1288  if (!Parent->LookupPtr)
1289    Parent->CreateStoredDeclsMap(C);
1290
1291  DependentStoredDeclsMap *Map
1292    = static_cast<DependentStoredDeclsMap*>(Parent->LookupPtr);
1293
1294  // Allocate the copy of the PartialDiagnostic via the ASTContext's
1295  // BumpPtrAllocator, rather than the ASTContext itself.
1296  PartialDiagnostic::Storage *DiagStorage = 0;
1297  if (PDiag.hasStorage())
1298    DiagStorage = new (C) PartialDiagnostic::Storage;
1299
1300  DependentDiagnostic *DD = new (C) DependentDiagnostic(PDiag, DiagStorage);
1301
1302  // TODO: Maybe we shouldn't reverse the order during insertion.
1303  DD->NextDiagnostic = Map->FirstDiagnostic;
1304  Map->FirstDiagnostic = DD;
1305
1306  return DD;
1307}
1308