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/ASTContext.h"
16#include "clang/AST/ASTMutationListener.h"
17#include "clang/AST/Attr.h"
18#include "clang/AST/Decl.h"
19#include "clang/AST/DeclCXX.h"
20#include "clang/AST/DeclContextInternals.h"
21#include "clang/AST/DeclFriend.h"
22#include "clang/AST/DeclObjC.h"
23#include "clang/AST/DeclOpenMP.h"
24#include "clang/AST/DeclTemplate.h"
25#include "clang/AST/DependentDiagnostic.h"
26#include "clang/AST/ExternalASTSource.h"
27#include "clang/AST/Stmt.h"
28#include "clang/AST/StmtCXX.h"
29#include "clang/AST/Type.h"
30#include "clang/Basic/TargetInfo.h"
31#include "llvm/ADT/DenseMap.h"
32#include "llvm/Support/raw_ostream.h"
33#include <algorithm>
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
44void Decl::updateOutOfDate(IdentifierInfo &II) const {
45  getASTContext().getExternalSource()->updateOutOfDateIdentifier(II);
46}
47
48#define DECL(DERIVED, BASE)                                                    \
49  static_assert(llvm::AlignOf<Decl>::Alignment >=                              \
50                    llvm::AlignOf<DERIVED##Decl>::Alignment,                   \
51                "Alignment sufficient after objects prepended to " #DERIVED);
52#define ABSTRACT_DECL(DECL)
53#include "clang/AST/DeclNodes.inc"
54
55void *Decl::operator new(std::size_t Size, const ASTContext &Context,
56                         unsigned ID, std::size_t Extra) {
57  // Allocate an extra 8 bytes worth of storage, which ensures that the
58  // resulting pointer will still be 8-byte aligned.
59  static_assert(sizeof(unsigned) * 2 >= llvm::AlignOf<Decl>::Alignment,
60                "Decl won't be misaligned");
61  void *Start = Context.Allocate(Size + Extra + 8);
62  void *Result = (char*)Start + 8;
63
64  unsigned *PrefixPtr = (unsigned *)Result - 2;
65
66  // Zero out the first 4 bytes; this is used to store the owning module ID.
67  PrefixPtr[0] = 0;
68
69  // Store the global declaration ID in the second 4 bytes.
70  PrefixPtr[1] = ID;
71
72  return Result;
73}
74
75void *Decl::operator new(std::size_t Size, const ASTContext &Ctx,
76                         DeclContext *Parent, std::size_t Extra) {
77  assert(!Parent || &Parent->getParentASTContext() == &Ctx);
78  // With local visibility enabled, we track the owning module even for local
79  // declarations.
80  if (Ctx.getLangOpts().ModulesLocalVisibility) {
81    // Ensure required alignment of the resulting object by adding extra
82    // padding at the start if required.
83    size_t ExtraAlign =
84        llvm::OffsetToAlignment(sizeof(Module *),
85                                llvm::AlignOf<Decl>::Alignment);
86    char *Buffer = reinterpret_cast<char *>(
87        ::operator new(ExtraAlign + sizeof(Module *) + Size + Extra, Ctx));
88    Buffer += ExtraAlign;
89    return new (Buffer) Module*(nullptr) + 1;
90  }
91  return ::operator new(Size + Extra, Ctx);
92}
93
94Module *Decl::getOwningModuleSlow() const {
95  assert(isFromASTFile() && "Not from AST file?");
96  return getASTContext().getExternalSource()->getModule(getOwningModuleID());
97}
98
99bool Decl::hasLocalOwningModuleStorage() const {
100  return getASTContext().getLangOpts().ModulesLocalVisibility;
101}
102
103const char *Decl::getDeclKindName() const {
104  switch (DeclKind) {
105  default: llvm_unreachable("Declaration not in DeclNodes.inc!");
106#define DECL(DERIVED, BASE) case DERIVED: return #DERIVED;
107#define ABSTRACT_DECL(DECL)
108#include "clang/AST/DeclNodes.inc"
109  }
110}
111
112void Decl::setInvalidDecl(bool Invalid) {
113  InvalidDecl = Invalid;
114  assert(!isa<TagDecl>(this) || !cast<TagDecl>(this)->isCompleteDefinition());
115  if (Invalid && !isa<ParmVarDecl>(this)) {
116    // Defensive maneuver for ill-formed code: we're likely not to make it to
117    // a point where we set the access specifier, so default it to "public"
118    // to avoid triggering asserts elsewhere in the front end.
119    setAccess(AS_public);
120  }
121}
122
123const char *DeclContext::getDeclKindName() const {
124  switch (DeclKind) {
125  default: llvm_unreachable("Declaration context not in DeclNodes.inc!");
126#define DECL(DERIVED, BASE) case Decl::DERIVED: return #DERIVED;
127#define ABSTRACT_DECL(DECL)
128#include "clang/AST/DeclNodes.inc"
129  }
130}
131
132bool Decl::StatisticsEnabled = false;
133void Decl::EnableStatistics() {
134  StatisticsEnabled = true;
135}
136
137void Decl::PrintStats() {
138  llvm::errs() << "\n*** Decl Stats:\n";
139
140  int totalDecls = 0;
141#define DECL(DERIVED, BASE) totalDecls += n##DERIVED##s;
142#define ABSTRACT_DECL(DECL)
143#include "clang/AST/DeclNodes.inc"
144  llvm::errs() << "  " << totalDecls << " decls total.\n";
145
146  int totalBytes = 0;
147#define DECL(DERIVED, BASE)                                             \
148  if (n##DERIVED##s > 0) {                                              \
149    totalBytes += (int)(n##DERIVED##s * sizeof(DERIVED##Decl));         \
150    llvm::errs() << "    " << n##DERIVED##s << " " #DERIVED " decls, "  \
151                 << sizeof(DERIVED##Decl) << " each ("                  \
152                 << n##DERIVED##s * sizeof(DERIVED##Decl)               \
153                 << " bytes)\n";                                        \
154  }
155#define ABSTRACT_DECL(DECL)
156#include "clang/AST/DeclNodes.inc"
157
158  llvm::errs() << "Total bytes = " << totalBytes << "\n";
159}
160
161void Decl::add(Kind k) {
162  switch (k) {
163#define DECL(DERIVED, BASE) case DERIVED: ++n##DERIVED##s; break;
164#define ABSTRACT_DECL(DECL)
165#include "clang/AST/DeclNodes.inc"
166  }
167}
168
169bool Decl::isTemplateParameterPack() const {
170  if (const TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(this))
171    return TTP->isParameterPack();
172  if (const NonTypeTemplateParmDecl *NTTP
173                                = dyn_cast<NonTypeTemplateParmDecl>(this))
174    return NTTP->isParameterPack();
175  if (const TemplateTemplateParmDecl *TTP
176                                    = dyn_cast<TemplateTemplateParmDecl>(this))
177    return TTP->isParameterPack();
178  return false;
179}
180
181bool Decl::isParameterPack() const {
182  if (const ParmVarDecl *Parm = dyn_cast<ParmVarDecl>(this))
183    return Parm->isParameterPack();
184
185  return isTemplateParameterPack();
186}
187
188FunctionDecl *Decl::getAsFunction() {
189  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(this))
190    return FD;
191  if (const FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(this))
192    return FTD->getTemplatedDecl();
193  return nullptr;
194}
195
196bool Decl::isTemplateDecl() const {
197  return isa<TemplateDecl>(this);
198}
199
200TemplateDecl *Decl::getDescribedTemplate() const {
201  if (auto *FD = dyn_cast<FunctionDecl>(this))
202    return FD->getDescribedFunctionTemplate();
203  else if (auto *RD = dyn_cast<CXXRecordDecl>(this))
204    return RD->getDescribedClassTemplate();
205  else if (auto *VD = dyn_cast<VarDecl>(this))
206    return VD->getDescribedVarTemplate();
207
208  return nullptr;
209}
210
211const DeclContext *Decl::getParentFunctionOrMethod() const {
212  for (const DeclContext *DC = getDeclContext();
213       DC && !DC->isTranslationUnit() && !DC->isNamespace();
214       DC = DC->getParent())
215    if (DC->isFunctionOrMethod())
216      return DC;
217
218  return nullptr;
219}
220
221
222//===----------------------------------------------------------------------===//
223// PrettyStackTraceDecl Implementation
224//===----------------------------------------------------------------------===//
225
226void PrettyStackTraceDecl::print(raw_ostream &OS) const {
227  SourceLocation TheLoc = Loc;
228  if (TheLoc.isInvalid() && TheDecl)
229    TheLoc = TheDecl->getLocation();
230
231  if (TheLoc.isValid()) {
232    TheLoc.print(OS, SM);
233    OS << ": ";
234  }
235
236  OS << Message;
237
238  if (const NamedDecl *DN = dyn_cast_or_null<NamedDecl>(TheDecl)) {
239    OS << " '";
240    DN->printQualifiedName(OS);
241    OS << '\'';
242  }
243  OS << '\n';
244}
245
246//===----------------------------------------------------------------------===//
247// Decl Implementation
248//===----------------------------------------------------------------------===//
249
250// Out-of-line virtual method providing a home for Decl.
251Decl::~Decl() { }
252
253void Decl::setDeclContext(DeclContext *DC) {
254  DeclCtx = DC;
255}
256
257void Decl::setLexicalDeclContext(DeclContext *DC) {
258  if (DC == getLexicalDeclContext())
259    return;
260
261  if (isInSemaDC()) {
262    setDeclContextsImpl(getDeclContext(), DC, getASTContext());
263  } else {
264    getMultipleDC()->LexicalDC = DC;
265  }
266  Hidden = cast<Decl>(DC)->Hidden;
267}
268
269void Decl::setDeclContextsImpl(DeclContext *SemaDC, DeclContext *LexicalDC,
270                               ASTContext &Ctx) {
271  if (SemaDC == LexicalDC) {
272    DeclCtx = SemaDC;
273  } else {
274    Decl::MultipleDC *MDC = new (Ctx) Decl::MultipleDC();
275    MDC->SemanticDC = SemaDC;
276    MDC->LexicalDC = LexicalDC;
277    DeclCtx = MDC;
278  }
279}
280
281bool Decl::isLexicallyWithinFunctionOrMethod() const {
282  const DeclContext *LDC = getLexicalDeclContext();
283  while (true) {
284    if (LDC->isFunctionOrMethod())
285      return true;
286    if (!isa<TagDecl>(LDC))
287      return false;
288    LDC = LDC->getLexicalParent();
289  }
290  return false;
291}
292
293bool Decl::isInAnonymousNamespace() const {
294  const DeclContext *DC = getDeclContext();
295  do {
296    if (const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(DC))
297      if (ND->isAnonymousNamespace())
298        return true;
299  } while ((DC = DC->getParent()));
300
301  return false;
302}
303
304bool Decl::isInStdNamespace() const {
305  return getDeclContext()->isStdNamespace();
306}
307
308TranslationUnitDecl *Decl::getTranslationUnitDecl() {
309  if (TranslationUnitDecl *TUD = dyn_cast<TranslationUnitDecl>(this))
310    return TUD;
311
312  DeclContext *DC = getDeclContext();
313  assert(DC && "This decl is not contained in a translation unit!");
314
315  while (!DC->isTranslationUnit()) {
316    DC = DC->getParent();
317    assert(DC && "This decl is not contained in a translation unit!");
318  }
319
320  return cast<TranslationUnitDecl>(DC);
321}
322
323ASTContext &Decl::getASTContext() const {
324  return getTranslationUnitDecl()->getASTContext();
325}
326
327ASTMutationListener *Decl::getASTMutationListener() const {
328  return getASTContext().getASTMutationListener();
329}
330
331unsigned Decl::getMaxAlignment() const {
332  if (!hasAttrs())
333    return 0;
334
335  unsigned Align = 0;
336  const AttrVec &V = getAttrs();
337  ASTContext &Ctx = getASTContext();
338  specific_attr_iterator<AlignedAttr> I(V.begin()), E(V.end());
339  for (; I != E; ++I)
340    Align = std::max(Align, I->getAlignment(Ctx));
341  return Align;
342}
343
344bool Decl::isUsed(bool CheckUsedAttr) const {
345  const Decl *CanonD = getCanonicalDecl();
346  if (CanonD->Used)
347    return true;
348
349  // Check for used attribute.
350  // Ask the most recent decl, since attributes accumulate in the redecl chain.
351  if (CheckUsedAttr && getMostRecentDecl()->hasAttr<UsedAttr>())
352    return true;
353
354  // The information may have not been deserialized yet. Force deserialization
355  // to complete the needed information.
356  return getMostRecentDecl()->getCanonicalDecl()->Used;
357}
358
359void Decl::markUsed(ASTContext &C) {
360  if (isUsed(false))
361    return;
362
363  if (C.getASTMutationListener())
364    C.getASTMutationListener()->DeclarationMarkedUsed(this);
365
366  setIsUsed();
367}
368
369bool Decl::isReferenced() const {
370  if (Referenced)
371    return true;
372
373  // Check redeclarations.
374  for (auto I : redecls())
375    if (I->Referenced)
376      return true;
377
378  return false;
379}
380
381bool Decl::hasDefiningAttr() const {
382  return hasAttr<AliasAttr>() || hasAttr<IFuncAttr>();
383}
384
385const Attr *Decl::getDefiningAttr() const {
386  if (AliasAttr *AA = getAttr<AliasAttr>())
387    return AA;
388  if (IFuncAttr *IFA = getAttr<IFuncAttr>())
389    return IFA;
390  return nullptr;
391}
392
393/// \brief Determine the availability of the given declaration based on
394/// the target platform.
395///
396/// When it returns an availability result other than \c AR_Available,
397/// if the \p Message parameter is non-NULL, it will be set to a
398/// string describing why the entity is unavailable.
399///
400/// FIXME: Make these strings localizable, since they end up in
401/// diagnostics.
402static AvailabilityResult CheckAvailability(ASTContext &Context,
403                                            const AvailabilityAttr *A,
404                                            std::string *Message) {
405  VersionTuple TargetMinVersion =
406    Context.getTargetInfo().getPlatformMinVersion();
407
408  if (TargetMinVersion.empty())
409    return AR_Available;
410
411  // Check if this is an App Extension "platform", and if so chop off
412  // the suffix for matching with the actual platform.
413  StringRef ActualPlatform = A->getPlatform()->getName();
414  StringRef RealizedPlatform = ActualPlatform;
415  if (Context.getLangOpts().AppExt) {
416    size_t suffix = RealizedPlatform.rfind("_app_extension");
417    if (suffix != StringRef::npos)
418      RealizedPlatform = RealizedPlatform.slice(0, suffix);
419  }
420
421  StringRef TargetPlatform = Context.getTargetInfo().getPlatformName();
422
423  // Match the platform name.
424  if (RealizedPlatform != TargetPlatform)
425    return AR_Available;
426
427  StringRef PrettyPlatformName
428    = AvailabilityAttr::getPrettyPlatformName(ActualPlatform);
429
430  if (PrettyPlatformName.empty())
431    PrettyPlatformName = ActualPlatform;
432
433  std::string HintMessage;
434  if (!A->getMessage().empty()) {
435    HintMessage = " - ";
436    HintMessage += A->getMessage();
437  }
438
439  // Make sure that this declaration has not been marked 'unavailable'.
440  if (A->getUnavailable()) {
441    if (Message) {
442      Message->clear();
443      llvm::raw_string_ostream Out(*Message);
444      Out << "not available on " << PrettyPlatformName
445          << HintMessage;
446    }
447
448    return AR_Unavailable;
449  }
450
451  // Make sure that this declaration has already been introduced.
452  if (!A->getIntroduced().empty() &&
453      TargetMinVersion < A->getIntroduced()) {
454    if (Message) {
455      Message->clear();
456      llvm::raw_string_ostream Out(*Message);
457      VersionTuple VTI(A->getIntroduced());
458      VTI.UseDotAsSeparator();
459      Out << "introduced in " << PrettyPlatformName << ' '
460          << VTI << HintMessage;
461    }
462
463    return A->getStrict() ? AR_Unavailable : AR_NotYetIntroduced;
464  }
465
466  // Make sure that this declaration hasn't been obsoleted.
467  if (!A->getObsoleted().empty() && TargetMinVersion >= A->getObsoleted()) {
468    if (Message) {
469      Message->clear();
470      llvm::raw_string_ostream Out(*Message);
471      VersionTuple VTO(A->getObsoleted());
472      VTO.UseDotAsSeparator();
473      Out << "obsoleted in " << PrettyPlatformName << ' '
474          << VTO << HintMessage;
475    }
476
477    return AR_Unavailable;
478  }
479
480  // Make sure that this declaration hasn't been deprecated.
481  if (!A->getDeprecated().empty() && TargetMinVersion >= A->getDeprecated()) {
482    if (Message) {
483      Message->clear();
484      llvm::raw_string_ostream Out(*Message);
485      VersionTuple VTD(A->getDeprecated());
486      VTD.UseDotAsSeparator();
487      Out << "first deprecated in " << PrettyPlatformName << ' '
488          << VTD << HintMessage;
489    }
490
491    return AR_Deprecated;
492  }
493
494  return AR_Available;
495}
496
497AvailabilityResult Decl::getAvailability(std::string *Message) const {
498  if (auto *FTD = dyn_cast<FunctionTemplateDecl>(this))
499    return FTD->getTemplatedDecl()->getAvailability(Message);
500
501  AvailabilityResult Result = AR_Available;
502  std::string ResultMessage;
503
504  for (const auto *A : attrs()) {
505    if (const auto *Deprecated = dyn_cast<DeprecatedAttr>(A)) {
506      if (Result >= AR_Deprecated)
507        continue;
508
509      if (Message)
510        ResultMessage = Deprecated->getMessage();
511
512      Result = AR_Deprecated;
513      continue;
514    }
515
516    if (const auto *Unavailable = dyn_cast<UnavailableAttr>(A)) {
517      if (Message)
518        *Message = Unavailable->getMessage();
519      return AR_Unavailable;
520    }
521
522    if (const auto *Availability = dyn_cast<AvailabilityAttr>(A)) {
523      AvailabilityResult AR = CheckAvailability(getASTContext(), Availability,
524                                                Message);
525
526      if (AR == AR_Unavailable)
527        return AR_Unavailable;
528
529      if (AR > Result) {
530        Result = AR;
531        if (Message)
532          ResultMessage.swap(*Message);
533      }
534      continue;
535    }
536  }
537
538  if (Message)
539    Message->swap(ResultMessage);
540  return Result;
541}
542
543bool Decl::canBeWeakImported(bool &IsDefinition) const {
544  IsDefinition = false;
545
546  // Variables, if they aren't definitions.
547  if (const VarDecl *Var = dyn_cast<VarDecl>(this)) {
548    if (Var->isThisDeclarationADefinition()) {
549      IsDefinition = true;
550      return false;
551    }
552    return true;
553
554  // Functions, if they aren't definitions.
555  } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(this)) {
556    if (FD->hasBody()) {
557      IsDefinition = true;
558      return false;
559    }
560    return true;
561
562  // Objective-C classes, if this is the non-fragile runtime.
563  } else if (isa<ObjCInterfaceDecl>(this) &&
564             getASTContext().getLangOpts().ObjCRuntime.hasWeakClassImport()) {
565    return true;
566
567  // Nothing else.
568  } else {
569    return false;
570  }
571}
572
573bool Decl::isWeakImported() const {
574  bool IsDefinition;
575  if (!canBeWeakImported(IsDefinition))
576    return false;
577
578  for (const auto *A : attrs()) {
579    if (isa<WeakImportAttr>(A))
580      return true;
581
582    if (const auto *Availability = dyn_cast<AvailabilityAttr>(A)) {
583      if (CheckAvailability(getASTContext(), Availability,
584                            nullptr) == AR_NotYetIntroduced)
585        return true;
586    }
587  }
588
589  return false;
590}
591
592unsigned Decl::getIdentifierNamespaceForKind(Kind DeclKind) {
593  switch (DeclKind) {
594    case Function:
595    case CXXMethod:
596    case CXXConstructor:
597    case ConstructorUsingShadow:
598    case CXXDestructor:
599    case CXXConversion:
600    case EnumConstant:
601    case Var:
602    case ImplicitParam:
603    case ParmVar:
604    case ObjCMethod:
605    case ObjCProperty:
606    case MSProperty:
607      return IDNS_Ordinary;
608    case Label:
609      return IDNS_Label;
610    case IndirectField:
611      return IDNS_Ordinary | IDNS_Member;
612
613    case NonTypeTemplateParm:
614      // Non-type template parameters are not found by lookups that ignore
615      // non-types, but they are found by redeclaration lookups for tag types,
616      // so we include them in the tag namespace.
617      return IDNS_Ordinary | IDNS_Tag;
618
619    case ObjCCompatibleAlias:
620    case ObjCInterface:
621      return IDNS_Ordinary | IDNS_Type;
622
623    case Typedef:
624    case TypeAlias:
625    case TypeAliasTemplate:
626    case UnresolvedUsingTypename:
627    case TemplateTypeParm:
628    case ObjCTypeParam:
629      return IDNS_Ordinary | IDNS_Type;
630
631    case UsingShadow:
632      return 0; // we'll actually overwrite this later
633
634    case UnresolvedUsingValue:
635      return IDNS_Ordinary | IDNS_Using;
636
637    case Using:
638      return IDNS_Using;
639
640    case ObjCProtocol:
641      return IDNS_ObjCProtocol;
642
643    case Field:
644    case ObjCAtDefsField:
645    case ObjCIvar:
646      return IDNS_Member;
647
648    case Record:
649    case CXXRecord:
650    case Enum:
651      return IDNS_Tag | IDNS_Type;
652
653    case Namespace:
654    case NamespaceAlias:
655      return IDNS_Namespace;
656
657    case FunctionTemplate:
658    case VarTemplate:
659      return IDNS_Ordinary;
660
661    case ClassTemplate:
662    case TemplateTemplateParm:
663      return IDNS_Ordinary | IDNS_Tag | IDNS_Type;
664
665    case OMPDeclareReduction:
666      return IDNS_OMPReduction;
667
668    // Never have names.
669    case Friend:
670    case FriendTemplate:
671    case AccessSpec:
672    case LinkageSpec:
673    case FileScopeAsm:
674    case StaticAssert:
675    case ObjCPropertyImpl:
676    case PragmaComment:
677    case PragmaDetectMismatch:
678    case Block:
679    case Captured:
680    case TranslationUnit:
681    case ExternCContext:
682
683    case UsingDirective:
684    case BuiltinTemplate:
685    case ClassTemplateSpecialization:
686    case ClassTemplatePartialSpecialization:
687    case ClassScopeFunctionSpecialization:
688    case VarTemplateSpecialization:
689    case VarTemplatePartialSpecialization:
690    case ObjCImplementation:
691    case ObjCCategory:
692    case ObjCCategoryImpl:
693    case Import:
694    case OMPThreadPrivate:
695    case OMPCapturedExpr:
696    case Empty:
697      // Never looked up by name.
698      return 0;
699  }
700
701  llvm_unreachable("Invalid DeclKind!");
702}
703
704void Decl::setAttrsImpl(const AttrVec &attrs, ASTContext &Ctx) {
705  assert(!HasAttrs && "Decl already contains attrs.");
706
707  AttrVec &AttrBlank = Ctx.getDeclAttrs(this);
708  assert(AttrBlank.empty() && "HasAttrs was wrong?");
709
710  AttrBlank = attrs;
711  HasAttrs = true;
712}
713
714void Decl::dropAttrs() {
715  if (!HasAttrs) return;
716
717  HasAttrs = false;
718  getASTContext().eraseDeclAttrs(this);
719}
720
721const AttrVec &Decl::getAttrs() const {
722  assert(HasAttrs && "No attrs to get!");
723  return getASTContext().getDeclAttrs(this);
724}
725
726Decl *Decl::castFromDeclContext (const DeclContext *D) {
727  Decl::Kind DK = D->getDeclKind();
728  switch(DK) {
729#define DECL(NAME, BASE)
730#define DECL_CONTEXT(NAME) \
731    case Decl::NAME:       \
732      return static_cast<NAME##Decl*>(const_cast<DeclContext*>(D));
733#define DECL_CONTEXT_BASE(NAME)
734#include "clang/AST/DeclNodes.inc"
735    default:
736#define DECL(NAME, BASE)
737#define DECL_CONTEXT_BASE(NAME)                  \
738      if (DK >= first##NAME && DK <= last##NAME) \
739        return static_cast<NAME##Decl*>(const_cast<DeclContext*>(D));
740#include "clang/AST/DeclNodes.inc"
741      llvm_unreachable("a decl that inherits DeclContext isn't handled");
742  }
743}
744
745DeclContext *Decl::castToDeclContext(const Decl *D) {
746  Decl::Kind DK = D->getKind();
747  switch(DK) {
748#define DECL(NAME, BASE)
749#define DECL_CONTEXT(NAME) \
750    case Decl::NAME:       \
751      return static_cast<NAME##Decl*>(const_cast<Decl*>(D));
752#define DECL_CONTEXT_BASE(NAME)
753#include "clang/AST/DeclNodes.inc"
754    default:
755#define DECL(NAME, BASE)
756#define DECL_CONTEXT_BASE(NAME)                                   \
757      if (DK >= first##NAME && DK <= last##NAME)                  \
758        return static_cast<NAME##Decl*>(const_cast<Decl*>(D));
759#include "clang/AST/DeclNodes.inc"
760      llvm_unreachable("a decl that inherits DeclContext isn't handled");
761  }
762}
763
764SourceLocation Decl::getBodyRBrace() const {
765  // Special handling of FunctionDecl to avoid de-serializing the body from PCH.
766  // FunctionDecl stores EndRangeLoc for this purpose.
767  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(this)) {
768    const FunctionDecl *Definition;
769    if (FD->hasBody(Definition))
770      return Definition->getSourceRange().getEnd();
771    return SourceLocation();
772  }
773
774  if (Stmt *Body = getBody())
775    return Body->getSourceRange().getEnd();
776
777  return SourceLocation();
778}
779
780bool Decl::AccessDeclContextSanity() const {
781#ifndef NDEBUG
782  // Suppress this check if any of the following hold:
783  // 1. this is the translation unit (and thus has no parent)
784  // 2. this is a template parameter (and thus doesn't belong to its context)
785  // 3. this is a non-type template parameter
786  // 4. the context is not a record
787  // 5. it's invalid
788  // 6. it's a C++0x static_assert.
789  if (isa<TranslationUnitDecl>(this) ||
790      isa<TemplateTypeParmDecl>(this) ||
791      isa<NonTypeTemplateParmDecl>(this) ||
792      !isa<CXXRecordDecl>(getDeclContext()) ||
793      isInvalidDecl() ||
794      isa<StaticAssertDecl>(this) ||
795      // FIXME: a ParmVarDecl can have ClassTemplateSpecialization
796      // as DeclContext (?).
797      isa<ParmVarDecl>(this) ||
798      // FIXME: a ClassTemplateSpecialization or CXXRecordDecl can have
799      // AS_none as access specifier.
800      isa<CXXRecordDecl>(this) ||
801      isa<ClassScopeFunctionSpecializationDecl>(this))
802    return true;
803
804  assert(Access != AS_none &&
805         "Access specifier is AS_none inside a record decl");
806#endif
807  return true;
808}
809
810static Decl::Kind getKind(const Decl *D) { return D->getKind(); }
811static Decl::Kind getKind(const DeclContext *DC) { return DC->getDeclKind(); }
812
813const FunctionType *Decl::getFunctionType(bool BlocksToo) const {
814  QualType Ty;
815  if (const ValueDecl *D = dyn_cast<ValueDecl>(this))
816    Ty = D->getType();
817  else if (const TypedefNameDecl *D = dyn_cast<TypedefNameDecl>(this))
818    Ty = D->getUnderlyingType();
819  else
820    return nullptr;
821
822  if (Ty->isFunctionPointerType())
823    Ty = Ty->getAs<PointerType>()->getPointeeType();
824  else if (BlocksToo && Ty->isBlockPointerType())
825    Ty = Ty->getAs<BlockPointerType>()->getPointeeType();
826
827  return Ty->getAs<FunctionType>();
828}
829
830
831/// Starting at a given context (a Decl or DeclContext), look for a
832/// code context that is not a closure (a lambda, block, etc.).
833template <class T> static Decl *getNonClosureContext(T *D) {
834  if (getKind(D) == Decl::CXXMethod) {
835    CXXMethodDecl *MD = cast<CXXMethodDecl>(D);
836    if (MD->getOverloadedOperator() == OO_Call &&
837        MD->getParent()->isLambda())
838      return getNonClosureContext(MD->getParent()->getParent());
839    return MD;
840  } else if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
841    return FD;
842  } else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
843    return MD;
844  } else if (BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
845    return getNonClosureContext(BD->getParent());
846  } else if (CapturedDecl *CD = dyn_cast<CapturedDecl>(D)) {
847    return getNonClosureContext(CD->getParent());
848  } else {
849    return nullptr;
850  }
851}
852
853Decl *Decl::getNonClosureContext() {
854  return ::getNonClosureContext(this);
855}
856
857Decl *DeclContext::getNonClosureAncestor() {
858  return ::getNonClosureContext(this);
859}
860
861//===----------------------------------------------------------------------===//
862// DeclContext Implementation
863//===----------------------------------------------------------------------===//
864
865bool DeclContext::classof(const Decl *D) {
866  switch (D->getKind()) {
867#define DECL(NAME, BASE)
868#define DECL_CONTEXT(NAME) case Decl::NAME:
869#define DECL_CONTEXT_BASE(NAME)
870#include "clang/AST/DeclNodes.inc"
871      return true;
872    default:
873#define DECL(NAME, BASE)
874#define DECL_CONTEXT_BASE(NAME)                 \
875      if (D->getKind() >= Decl::first##NAME &&  \
876          D->getKind() <= Decl::last##NAME)     \
877        return true;
878#include "clang/AST/DeclNodes.inc"
879      return false;
880  }
881}
882
883DeclContext::~DeclContext() { }
884
885/// \brief Find the parent context of this context that will be
886/// used for unqualified name lookup.
887///
888/// Generally, the parent lookup context is the semantic context. However, for
889/// a friend function the parent lookup context is the lexical context, which
890/// is the class in which the friend is declared.
891DeclContext *DeclContext::getLookupParent() {
892  // FIXME: Find a better way to identify friends
893  if (isa<FunctionDecl>(this))
894    if (getParent()->getRedeclContext()->isFileContext() &&
895        getLexicalParent()->getRedeclContext()->isRecord())
896      return getLexicalParent();
897
898  return getParent();
899}
900
901bool DeclContext::isInlineNamespace() const {
902  return isNamespace() &&
903         cast<NamespaceDecl>(this)->isInline();
904}
905
906bool DeclContext::isStdNamespace() const {
907  if (!isNamespace())
908    return false;
909
910  const NamespaceDecl *ND = cast<NamespaceDecl>(this);
911  if (ND->isInline()) {
912    return ND->getParent()->isStdNamespace();
913  }
914
915  if (!getParent()->getRedeclContext()->isTranslationUnit())
916    return false;
917
918  const IdentifierInfo *II = ND->getIdentifier();
919  return II && II->isStr("std");
920}
921
922bool DeclContext::isDependentContext() const {
923  if (isFileContext())
924    return false;
925
926  if (isa<ClassTemplatePartialSpecializationDecl>(this))
927    return true;
928
929  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(this)) {
930    if (Record->getDescribedClassTemplate())
931      return true;
932
933    if (Record->isDependentLambda())
934      return true;
935  }
936
937  if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(this)) {
938    if (Function->getDescribedFunctionTemplate())
939      return true;
940
941    // Friend function declarations are dependent if their *lexical*
942    // context is dependent.
943    if (cast<Decl>(this)->getFriendObjectKind())
944      return getLexicalParent()->isDependentContext();
945  }
946
947  // FIXME: A variable template is a dependent context, but is not a
948  // DeclContext. A context within it (such as a lambda-expression)
949  // should be considered dependent.
950
951  return getParent() && getParent()->isDependentContext();
952}
953
954bool DeclContext::isTransparentContext() const {
955  if (DeclKind == Decl::Enum)
956    return !cast<EnumDecl>(this)->isScoped();
957  else if (DeclKind == Decl::LinkageSpec)
958    return true;
959
960  return false;
961}
962
963static bool isLinkageSpecContext(const DeclContext *DC,
964                                 LinkageSpecDecl::LanguageIDs ID) {
965  while (DC->getDeclKind() != Decl::TranslationUnit) {
966    if (DC->getDeclKind() == Decl::LinkageSpec)
967      return cast<LinkageSpecDecl>(DC)->getLanguage() == ID;
968    DC = DC->getLexicalParent();
969  }
970  return false;
971}
972
973bool DeclContext::isExternCContext() const {
974  return isLinkageSpecContext(this, clang::LinkageSpecDecl::lang_c);
975}
976
977bool DeclContext::isExternCXXContext() const {
978  return isLinkageSpecContext(this, clang::LinkageSpecDecl::lang_cxx);
979}
980
981bool DeclContext::Encloses(const DeclContext *DC) const {
982  if (getPrimaryContext() != this)
983    return getPrimaryContext()->Encloses(DC);
984
985  for (; DC; DC = DC->getParent())
986    if (DC->getPrimaryContext() == this)
987      return true;
988  return false;
989}
990
991DeclContext *DeclContext::getPrimaryContext() {
992  switch (DeclKind) {
993  case Decl::TranslationUnit:
994  case Decl::ExternCContext:
995  case Decl::LinkageSpec:
996  case Decl::Block:
997  case Decl::Captured:
998  case Decl::OMPDeclareReduction:
999    // There is only one DeclContext for these entities.
1000    return this;
1001
1002  case Decl::Namespace:
1003    // The original namespace is our primary context.
1004    return static_cast<NamespaceDecl*>(this)->getOriginalNamespace();
1005
1006  case Decl::ObjCMethod:
1007    return this;
1008
1009  case Decl::ObjCInterface:
1010    if (ObjCInterfaceDecl *Def = cast<ObjCInterfaceDecl>(this)->getDefinition())
1011      return Def;
1012
1013    return this;
1014
1015  case Decl::ObjCProtocol:
1016    if (ObjCProtocolDecl *Def = cast<ObjCProtocolDecl>(this)->getDefinition())
1017      return Def;
1018
1019    return this;
1020
1021  case Decl::ObjCCategory:
1022    return this;
1023
1024  case Decl::ObjCImplementation:
1025  case Decl::ObjCCategoryImpl:
1026    return this;
1027
1028  default:
1029    if (DeclKind >= Decl::firstTag && DeclKind <= Decl::lastTag) {
1030      // If this is a tag type that has a definition or is currently
1031      // being defined, that definition is our primary context.
1032      TagDecl *Tag = cast<TagDecl>(this);
1033
1034      if (TagDecl *Def = Tag->getDefinition())
1035        return Def;
1036
1037      if (const TagType *TagTy = dyn_cast<TagType>(Tag->getTypeForDecl())) {
1038        // Note, TagType::getDecl returns the (partial) definition one exists.
1039        TagDecl *PossiblePartialDef = TagTy->getDecl();
1040        if (PossiblePartialDef->isBeingDefined())
1041          return PossiblePartialDef;
1042      } else {
1043        assert(isa<InjectedClassNameType>(Tag->getTypeForDecl()));
1044      }
1045
1046      return Tag;
1047    }
1048
1049    assert(DeclKind >= Decl::firstFunction && DeclKind <= Decl::lastFunction &&
1050          "Unknown DeclContext kind");
1051    return this;
1052  }
1053}
1054
1055void
1056DeclContext::collectAllContexts(SmallVectorImpl<DeclContext *> &Contexts){
1057  Contexts.clear();
1058
1059  if (DeclKind != Decl::Namespace) {
1060    Contexts.push_back(this);
1061    return;
1062  }
1063
1064  NamespaceDecl *Self = static_cast<NamespaceDecl *>(this);
1065  for (NamespaceDecl *N = Self->getMostRecentDecl(); N;
1066       N = N->getPreviousDecl())
1067    Contexts.push_back(N);
1068
1069  std::reverse(Contexts.begin(), Contexts.end());
1070}
1071
1072std::pair<Decl *, Decl *>
1073DeclContext::BuildDeclChain(ArrayRef<Decl*> Decls,
1074                            bool FieldsAlreadyLoaded) {
1075  // Build up a chain of declarations via the Decl::NextInContextAndBits field.
1076  Decl *FirstNewDecl = nullptr;
1077  Decl *PrevDecl = nullptr;
1078  for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
1079    if (FieldsAlreadyLoaded && isa<FieldDecl>(Decls[I]))
1080      continue;
1081
1082    Decl *D = Decls[I];
1083    if (PrevDecl)
1084      PrevDecl->NextInContextAndBits.setPointer(D);
1085    else
1086      FirstNewDecl = D;
1087
1088    PrevDecl = D;
1089  }
1090
1091  return std::make_pair(FirstNewDecl, PrevDecl);
1092}
1093
1094/// \brief We have just acquired external visible storage, and we already have
1095/// built a lookup map. For every name in the map, pull in the new names from
1096/// the external storage.
1097void DeclContext::reconcileExternalVisibleStorage() const {
1098  assert(NeedToReconcileExternalVisibleStorage && LookupPtr);
1099  NeedToReconcileExternalVisibleStorage = false;
1100
1101  for (auto &Lookup : *LookupPtr)
1102    Lookup.second.setHasExternalDecls();
1103}
1104
1105/// \brief Load the declarations within this lexical storage from an
1106/// external source.
1107/// \return \c true if any declarations were added.
1108bool
1109DeclContext::LoadLexicalDeclsFromExternalStorage() const {
1110  ExternalASTSource *Source = getParentASTContext().getExternalSource();
1111  assert(hasExternalLexicalStorage() && Source && "No external storage?");
1112
1113  // Notify that we have a DeclContext that is initializing.
1114  ExternalASTSource::Deserializing ADeclContext(Source);
1115
1116  // Load the external declarations, if any.
1117  SmallVector<Decl*, 64> Decls;
1118  ExternalLexicalStorage = false;
1119  Source->FindExternalLexicalDecls(this, Decls);
1120
1121  if (Decls.empty())
1122    return false;
1123
1124  // We may have already loaded just the fields of this record, in which case
1125  // we need to ignore them.
1126  bool FieldsAlreadyLoaded = false;
1127  if (const RecordDecl *RD = dyn_cast<RecordDecl>(this))
1128    FieldsAlreadyLoaded = RD->LoadedFieldsFromExternalStorage;
1129
1130  // Splice the newly-read declarations into the beginning of the list
1131  // of declarations.
1132  Decl *ExternalFirst, *ExternalLast;
1133  std::tie(ExternalFirst, ExternalLast) =
1134      BuildDeclChain(Decls, FieldsAlreadyLoaded);
1135  ExternalLast->NextInContextAndBits.setPointer(FirstDecl);
1136  FirstDecl = ExternalFirst;
1137  if (!LastDecl)
1138    LastDecl = ExternalLast;
1139  return true;
1140}
1141
1142DeclContext::lookup_result
1143ExternalASTSource::SetNoExternalVisibleDeclsForName(const DeclContext *DC,
1144                                                    DeclarationName Name) {
1145  ASTContext &Context = DC->getParentASTContext();
1146  StoredDeclsMap *Map;
1147  if (!(Map = DC->LookupPtr))
1148    Map = DC->CreateStoredDeclsMap(Context);
1149  if (DC->NeedToReconcileExternalVisibleStorage)
1150    DC->reconcileExternalVisibleStorage();
1151
1152  (*Map)[Name].removeExternalDecls();
1153
1154  return DeclContext::lookup_result();
1155}
1156
1157DeclContext::lookup_result
1158ExternalASTSource::SetExternalVisibleDeclsForName(const DeclContext *DC,
1159                                                  DeclarationName Name,
1160                                                  ArrayRef<NamedDecl*> Decls) {
1161  ASTContext &Context = DC->getParentASTContext();
1162  StoredDeclsMap *Map;
1163  if (!(Map = DC->LookupPtr))
1164    Map = DC->CreateStoredDeclsMap(Context);
1165  if (DC->NeedToReconcileExternalVisibleStorage)
1166    DC->reconcileExternalVisibleStorage();
1167
1168  StoredDeclsList &List = (*Map)[Name];
1169
1170  // Clear out any old external visible declarations, to avoid quadratic
1171  // performance in the redeclaration checks below.
1172  List.removeExternalDecls();
1173
1174  if (!List.isNull()) {
1175    // We have both existing declarations and new declarations for this name.
1176    // Some of the declarations may simply replace existing ones. Handle those
1177    // first.
1178    llvm::SmallVector<unsigned, 8> Skip;
1179    for (unsigned I = 0, N = Decls.size(); I != N; ++I)
1180      if (List.HandleRedeclaration(Decls[I], /*IsKnownNewer*/false))
1181        Skip.push_back(I);
1182    Skip.push_back(Decls.size());
1183
1184    // Add in any new declarations.
1185    unsigned SkipPos = 0;
1186    for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
1187      if (I == Skip[SkipPos])
1188        ++SkipPos;
1189      else
1190        List.AddSubsequentDecl(Decls[I]);
1191    }
1192  } else {
1193    // Convert the array to a StoredDeclsList.
1194    for (ArrayRef<NamedDecl*>::iterator
1195           I = Decls.begin(), E = Decls.end(); I != E; ++I) {
1196      if (List.isNull())
1197        List.setOnlyValue(*I);
1198      else
1199        List.AddSubsequentDecl(*I);
1200    }
1201  }
1202
1203  return List.getLookupResult();
1204}
1205
1206DeclContext::decl_iterator DeclContext::decls_begin() const {
1207  if (hasExternalLexicalStorage())
1208    LoadLexicalDeclsFromExternalStorage();
1209  return decl_iterator(FirstDecl);
1210}
1211
1212bool DeclContext::decls_empty() const {
1213  if (hasExternalLexicalStorage())
1214    LoadLexicalDeclsFromExternalStorage();
1215
1216  return !FirstDecl;
1217}
1218
1219bool DeclContext::containsDecl(Decl *D) const {
1220  return (D->getLexicalDeclContext() == this &&
1221          (D->NextInContextAndBits.getPointer() || D == LastDecl));
1222}
1223
1224void DeclContext::removeDecl(Decl *D) {
1225  assert(D->getLexicalDeclContext() == this &&
1226         "decl being removed from non-lexical context");
1227  assert((D->NextInContextAndBits.getPointer() || D == LastDecl) &&
1228         "decl is not in decls list");
1229
1230  // Remove D from the decl chain.  This is O(n) but hopefully rare.
1231  if (D == FirstDecl) {
1232    if (D == LastDecl)
1233      FirstDecl = LastDecl = nullptr;
1234    else
1235      FirstDecl = D->NextInContextAndBits.getPointer();
1236  } else {
1237    for (Decl *I = FirstDecl; true; I = I->NextInContextAndBits.getPointer()) {
1238      assert(I && "decl not found in linked list");
1239      if (I->NextInContextAndBits.getPointer() == D) {
1240        I->NextInContextAndBits.setPointer(D->NextInContextAndBits.getPointer());
1241        if (D == LastDecl) LastDecl = I;
1242        break;
1243      }
1244    }
1245  }
1246
1247  // Mark that D is no longer in the decl chain.
1248  D->NextInContextAndBits.setPointer(nullptr);
1249
1250  // Remove D from the lookup table if necessary.
1251  if (isa<NamedDecl>(D)) {
1252    NamedDecl *ND = cast<NamedDecl>(D);
1253
1254    // Remove only decls that have a name
1255    if (!ND->getDeclName()) return;
1256
1257    auto *DC = this;
1258    do {
1259      StoredDeclsMap *Map = DC->getPrimaryContext()->LookupPtr;
1260      if (Map) {
1261        StoredDeclsMap::iterator Pos = Map->find(ND->getDeclName());
1262        assert(Pos != Map->end() && "no lookup entry for decl");
1263        if (Pos->second.getAsVector() || Pos->second.getAsDecl() == ND)
1264          Pos->second.remove(ND);
1265      }
1266    } while (DC->isTransparentContext() && (DC = DC->getParent()));
1267  }
1268}
1269
1270void DeclContext::addHiddenDecl(Decl *D) {
1271  assert(D->getLexicalDeclContext() == this &&
1272         "Decl inserted into wrong lexical context");
1273  assert(!D->getNextDeclInContext() && D != LastDecl &&
1274         "Decl already inserted into a DeclContext");
1275
1276  if (FirstDecl) {
1277    LastDecl->NextInContextAndBits.setPointer(D);
1278    LastDecl = D;
1279  } else {
1280    FirstDecl = LastDecl = D;
1281  }
1282
1283  // Notify a C++ record declaration that we've added a member, so it can
1284  // update its class-specific state.
1285  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(this))
1286    Record->addedMember(D);
1287
1288  // If this is a newly-created (not de-serialized) import declaration, wire
1289  // it in to the list of local import declarations.
1290  if (!D->isFromASTFile()) {
1291    if (ImportDecl *Import = dyn_cast<ImportDecl>(D))
1292      D->getASTContext().addedLocalImportDecl(Import);
1293  }
1294}
1295
1296void DeclContext::addDecl(Decl *D) {
1297  addHiddenDecl(D);
1298
1299  if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
1300    ND->getDeclContext()->getPrimaryContext()->
1301        makeDeclVisibleInContextWithFlags(ND, false, true);
1302}
1303
1304void DeclContext::addDeclInternal(Decl *D) {
1305  addHiddenDecl(D);
1306
1307  if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
1308    ND->getDeclContext()->getPrimaryContext()->
1309        makeDeclVisibleInContextWithFlags(ND, true, true);
1310}
1311
1312/// shouldBeHidden - Determine whether a declaration which was declared
1313/// within its semantic context should be invisible to qualified name lookup.
1314static bool shouldBeHidden(NamedDecl *D) {
1315  // Skip unnamed declarations.
1316  if (!D->getDeclName())
1317    return true;
1318
1319  // Skip entities that can't be found by name lookup into a particular
1320  // context.
1321  if ((D->getIdentifierNamespace() == 0 && !isa<UsingDirectiveDecl>(D)) ||
1322      D->isTemplateParameter())
1323    return true;
1324
1325  // Skip template specializations.
1326  // FIXME: This feels like a hack. Should DeclarationName support
1327  // template-ids, or is there a better way to keep specializations
1328  // from being visible?
1329  if (isa<ClassTemplateSpecializationDecl>(D))
1330    return true;
1331  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
1332    if (FD->isFunctionTemplateSpecialization())
1333      return true;
1334
1335  return false;
1336}
1337
1338/// buildLookup - Build the lookup data structure with all of the
1339/// declarations in this DeclContext (and any other contexts linked
1340/// to it or transparent contexts nested within it) and return it.
1341///
1342/// Note that the produced map may miss out declarations from an
1343/// external source. If it does, those entries will be marked with
1344/// the 'hasExternalDecls' flag.
1345StoredDeclsMap *DeclContext::buildLookup() {
1346  assert(this == getPrimaryContext() && "buildLookup called on non-primary DC");
1347
1348  if (!HasLazyLocalLexicalLookups && !HasLazyExternalLexicalLookups)
1349    return LookupPtr;
1350
1351  SmallVector<DeclContext *, 2> Contexts;
1352  collectAllContexts(Contexts);
1353
1354  if (HasLazyExternalLexicalLookups) {
1355    HasLazyExternalLexicalLookups = false;
1356    for (auto *DC : Contexts) {
1357      if (DC->hasExternalLexicalStorage())
1358        HasLazyLocalLexicalLookups |=
1359            DC->LoadLexicalDeclsFromExternalStorage();
1360    }
1361
1362    if (!HasLazyLocalLexicalLookups)
1363      return LookupPtr;
1364  }
1365
1366  for (auto *DC : Contexts)
1367    buildLookupImpl(DC, hasExternalVisibleStorage());
1368
1369  // We no longer have any lazy decls.
1370  HasLazyLocalLexicalLookups = false;
1371  return LookupPtr;
1372}
1373
1374/// buildLookupImpl - Build part of the lookup data structure for the
1375/// declarations contained within DCtx, which will either be this
1376/// DeclContext, a DeclContext linked to it, or a transparent context
1377/// nested within it.
1378void DeclContext::buildLookupImpl(DeclContext *DCtx, bool Internal) {
1379  for (Decl *D : DCtx->noload_decls()) {
1380    // Insert this declaration into the lookup structure, but only if
1381    // it's semantically within its decl context. Any other decls which
1382    // should be found in this context are added eagerly.
1383    //
1384    // If it's from an AST file, don't add it now. It'll get handled by
1385    // FindExternalVisibleDeclsByName if needed. Exception: if we're not
1386    // in C++, we do not track external visible decls for the TU, so in
1387    // that case we need to collect them all here.
1388    if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
1389      if (ND->getDeclContext() == DCtx && !shouldBeHidden(ND) &&
1390          (!ND->isFromASTFile() ||
1391           (isTranslationUnit() &&
1392            !getParentASTContext().getLangOpts().CPlusPlus)))
1393        makeDeclVisibleInContextImpl(ND, Internal);
1394
1395    // If this declaration is itself a transparent declaration context
1396    // or inline namespace, add the members of this declaration of that
1397    // context (recursively).
1398    if (DeclContext *InnerCtx = dyn_cast<DeclContext>(D))
1399      if (InnerCtx->isTransparentContext() || InnerCtx->isInlineNamespace())
1400        buildLookupImpl(InnerCtx, Internal);
1401  }
1402}
1403
1404NamedDecl *const DeclContextLookupResult::SingleElementDummyList = nullptr;
1405
1406DeclContext::lookup_result
1407DeclContext::lookup(DeclarationName Name) const {
1408  assert(DeclKind != Decl::LinkageSpec &&
1409         "Should not perform lookups into linkage specs!");
1410
1411  const DeclContext *PrimaryContext = getPrimaryContext();
1412  if (PrimaryContext != this)
1413    return PrimaryContext->lookup(Name);
1414
1415  // If we have an external source, ensure that any later redeclarations of this
1416  // context have been loaded, since they may add names to the result of this
1417  // lookup (or add external visible storage).
1418  ExternalASTSource *Source = getParentASTContext().getExternalSource();
1419  if (Source)
1420    (void)cast<Decl>(this)->getMostRecentDecl();
1421
1422  if (hasExternalVisibleStorage()) {
1423    assert(Source && "external visible storage but no external source?");
1424
1425    if (NeedToReconcileExternalVisibleStorage)
1426      reconcileExternalVisibleStorage();
1427
1428    StoredDeclsMap *Map = LookupPtr;
1429
1430    if (HasLazyLocalLexicalLookups || HasLazyExternalLexicalLookups)
1431      // FIXME: Make buildLookup const?
1432      Map = const_cast<DeclContext*>(this)->buildLookup();
1433
1434    if (!Map)
1435      Map = CreateStoredDeclsMap(getParentASTContext());
1436
1437    // If we have a lookup result with no external decls, we are done.
1438    std::pair<StoredDeclsMap::iterator, bool> R =
1439        Map->insert(std::make_pair(Name, StoredDeclsList()));
1440    if (!R.second && !R.first->second.hasExternalDecls())
1441      return R.first->second.getLookupResult();
1442
1443    if (Source->FindExternalVisibleDeclsByName(this, Name) || !R.second) {
1444      if (StoredDeclsMap *Map = LookupPtr) {
1445        StoredDeclsMap::iterator I = Map->find(Name);
1446        if (I != Map->end())
1447          return I->second.getLookupResult();
1448      }
1449    }
1450
1451    return lookup_result();
1452  }
1453
1454  StoredDeclsMap *Map = LookupPtr;
1455  if (HasLazyLocalLexicalLookups || HasLazyExternalLexicalLookups)
1456    Map = const_cast<DeclContext*>(this)->buildLookup();
1457
1458  if (!Map)
1459    return lookup_result();
1460
1461  StoredDeclsMap::iterator I = Map->find(Name);
1462  if (I == Map->end())
1463    return lookup_result();
1464
1465  return I->second.getLookupResult();
1466}
1467
1468DeclContext::lookup_result
1469DeclContext::noload_lookup(DeclarationName Name) {
1470  assert(DeclKind != Decl::LinkageSpec &&
1471         "Should not perform lookups into linkage specs!");
1472
1473  DeclContext *PrimaryContext = getPrimaryContext();
1474  if (PrimaryContext != this)
1475    return PrimaryContext->noload_lookup(Name);
1476
1477  // If we have any lazy lexical declarations not in our lookup map, add them
1478  // now. Don't import any external declarations, not even if we know we have
1479  // some missing from the external visible lookups.
1480  if (HasLazyLocalLexicalLookups) {
1481    SmallVector<DeclContext *, 2> Contexts;
1482    collectAllContexts(Contexts);
1483    for (unsigned I = 0, N = Contexts.size(); I != N; ++I)
1484      buildLookupImpl(Contexts[I], hasExternalVisibleStorage());
1485    HasLazyLocalLexicalLookups = false;
1486  }
1487
1488  StoredDeclsMap *Map = LookupPtr;
1489  if (!Map)
1490    return lookup_result();
1491
1492  StoredDeclsMap::iterator I = Map->find(Name);
1493  return I != Map->end() ? I->second.getLookupResult()
1494                         : lookup_result();
1495}
1496
1497void DeclContext::localUncachedLookup(DeclarationName Name,
1498                                      SmallVectorImpl<NamedDecl *> &Results) {
1499  Results.clear();
1500
1501  // If there's no external storage, just perform a normal lookup and copy
1502  // the results.
1503  if (!hasExternalVisibleStorage() && !hasExternalLexicalStorage() && Name) {
1504    lookup_result LookupResults = lookup(Name);
1505    Results.insert(Results.end(), LookupResults.begin(), LookupResults.end());
1506    return;
1507  }
1508
1509  // If we have a lookup table, check there first. Maybe we'll get lucky.
1510  // FIXME: Should we be checking these flags on the primary context?
1511  if (Name && !HasLazyLocalLexicalLookups && !HasLazyExternalLexicalLookups) {
1512    if (StoredDeclsMap *Map = LookupPtr) {
1513      StoredDeclsMap::iterator Pos = Map->find(Name);
1514      if (Pos != Map->end()) {
1515        Results.insert(Results.end(),
1516                       Pos->second.getLookupResult().begin(),
1517                       Pos->second.getLookupResult().end());
1518        return;
1519      }
1520    }
1521  }
1522
1523  // Slow case: grovel through the declarations in our chain looking for
1524  // matches.
1525  // FIXME: If we have lazy external declarations, this will not find them!
1526  // FIXME: Should we CollectAllContexts and walk them all here?
1527  for (Decl *D = FirstDecl; D; D = D->getNextDeclInContext()) {
1528    if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
1529      if (ND->getDeclName() == Name)
1530        Results.push_back(ND);
1531  }
1532}
1533
1534DeclContext *DeclContext::getRedeclContext() {
1535  DeclContext *Ctx = this;
1536  // Skip through transparent contexts.
1537  while (Ctx->isTransparentContext())
1538    Ctx = Ctx->getParent();
1539  return Ctx;
1540}
1541
1542DeclContext *DeclContext::getEnclosingNamespaceContext() {
1543  DeclContext *Ctx = this;
1544  // Skip through non-namespace, non-translation-unit contexts.
1545  while (!Ctx->isFileContext())
1546    Ctx = Ctx->getParent();
1547  return Ctx->getPrimaryContext();
1548}
1549
1550RecordDecl *DeclContext::getOuterLexicalRecordContext() {
1551  // Loop until we find a non-record context.
1552  RecordDecl *OutermostRD = nullptr;
1553  DeclContext *DC = this;
1554  while (DC->isRecord()) {
1555    OutermostRD = cast<RecordDecl>(DC);
1556    DC = DC->getLexicalParent();
1557  }
1558  return OutermostRD;
1559}
1560
1561bool DeclContext::InEnclosingNamespaceSetOf(const DeclContext *O) const {
1562  // For non-file contexts, this is equivalent to Equals.
1563  if (!isFileContext())
1564    return O->Equals(this);
1565
1566  do {
1567    if (O->Equals(this))
1568      return true;
1569
1570    const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(O);
1571    if (!NS || !NS->isInline())
1572      break;
1573    O = NS->getParent();
1574  } while (O);
1575
1576  return false;
1577}
1578
1579void DeclContext::makeDeclVisibleInContext(NamedDecl *D) {
1580  DeclContext *PrimaryDC = this->getPrimaryContext();
1581  DeclContext *DeclDC = D->getDeclContext()->getPrimaryContext();
1582  // If the decl is being added outside of its semantic decl context, we
1583  // need to ensure that we eagerly build the lookup information for it.
1584  PrimaryDC->makeDeclVisibleInContextWithFlags(D, false, PrimaryDC == DeclDC);
1585}
1586
1587void DeclContext::makeDeclVisibleInContextWithFlags(NamedDecl *D, bool Internal,
1588                                                    bool Recoverable) {
1589  assert(this == getPrimaryContext() && "expected a primary DC");
1590
1591  if (!isLookupContext()) {
1592    if (isTransparentContext())
1593      getParent()->getPrimaryContext()
1594        ->makeDeclVisibleInContextWithFlags(D, Internal, Recoverable);
1595    return;
1596  }
1597
1598  // Skip declarations which should be invisible to name lookup.
1599  if (shouldBeHidden(D))
1600    return;
1601
1602  // If we already have a lookup data structure, perform the insertion into
1603  // it. If we might have externally-stored decls with this name, look them
1604  // up and perform the insertion. If this decl was declared outside its
1605  // semantic context, buildLookup won't add it, so add it now.
1606  //
1607  // FIXME: As a performance hack, don't add such decls into the translation
1608  // unit unless we're in C++, since qualified lookup into the TU is never
1609  // performed.
1610  if (LookupPtr || hasExternalVisibleStorage() ||
1611      ((!Recoverable || D->getDeclContext() != D->getLexicalDeclContext()) &&
1612       (getParentASTContext().getLangOpts().CPlusPlus ||
1613        !isTranslationUnit()))) {
1614    // If we have lazily omitted any decls, they might have the same name as
1615    // the decl which we are adding, so build a full lookup table before adding
1616    // this decl.
1617    buildLookup();
1618    makeDeclVisibleInContextImpl(D, Internal);
1619  } else {
1620    HasLazyLocalLexicalLookups = true;
1621  }
1622
1623  // If we are a transparent context or inline namespace, insert into our
1624  // parent context, too. This operation is recursive.
1625  if (isTransparentContext() || isInlineNamespace())
1626    getParent()->getPrimaryContext()->
1627        makeDeclVisibleInContextWithFlags(D, Internal, Recoverable);
1628
1629  Decl *DCAsDecl = cast<Decl>(this);
1630  // Notify that a decl was made visible unless we are a Tag being defined.
1631  if (!(isa<TagDecl>(DCAsDecl) && cast<TagDecl>(DCAsDecl)->isBeingDefined()))
1632    if (ASTMutationListener *L = DCAsDecl->getASTMutationListener())
1633      L->AddedVisibleDecl(this, D);
1634}
1635
1636void DeclContext::makeDeclVisibleInContextImpl(NamedDecl *D, bool Internal) {
1637  // Find or create the stored declaration map.
1638  StoredDeclsMap *Map = LookupPtr;
1639  if (!Map) {
1640    ASTContext *C = &getParentASTContext();
1641    Map = CreateStoredDeclsMap(*C);
1642  }
1643
1644  // If there is an external AST source, load any declarations it knows about
1645  // with this declaration's name.
1646  // If the lookup table contains an entry about this name it means that we
1647  // have already checked the external source.
1648  if (!Internal)
1649    if (ExternalASTSource *Source = getParentASTContext().getExternalSource())
1650      if (hasExternalVisibleStorage() &&
1651          Map->find(D->getDeclName()) == Map->end())
1652        Source->FindExternalVisibleDeclsByName(this, D->getDeclName());
1653
1654  // Insert this declaration into the map.
1655  StoredDeclsList &DeclNameEntries = (*Map)[D->getDeclName()];
1656
1657  if (Internal) {
1658    // If this is being added as part of loading an external declaration,
1659    // this may not be the only external declaration with this name.
1660    // In this case, we never try to replace an existing declaration; we'll
1661    // handle that when we finalize the list of declarations for this name.
1662    DeclNameEntries.setHasExternalDecls();
1663    DeclNameEntries.AddSubsequentDecl(D);
1664    return;
1665  }
1666
1667  if (DeclNameEntries.isNull()) {
1668    DeclNameEntries.setOnlyValue(D);
1669    return;
1670  }
1671
1672  if (DeclNameEntries.HandleRedeclaration(D, /*IsKnownNewer*/!Internal)) {
1673    // This declaration has replaced an existing one for which
1674    // declarationReplaces returns true.
1675    return;
1676  }
1677
1678  // Put this declaration into the appropriate slot.
1679  DeclNameEntries.AddSubsequentDecl(D);
1680}
1681
1682UsingDirectiveDecl *DeclContext::udir_iterator::operator*() const {
1683  return cast<UsingDirectiveDecl>(*I);
1684}
1685
1686/// Returns iterator range [First, Last) of UsingDirectiveDecls stored within
1687/// this context.
1688DeclContext::udir_range DeclContext::using_directives() const {
1689  // FIXME: Use something more efficient than normal lookup for using
1690  // directives. In C++, using directives are looked up more than anything else.
1691  lookup_result Result = lookup(UsingDirectiveDecl::getName());
1692  return udir_range(Result.begin(), Result.end());
1693}
1694
1695//===----------------------------------------------------------------------===//
1696// Creation and Destruction of StoredDeclsMaps.                               //
1697//===----------------------------------------------------------------------===//
1698
1699StoredDeclsMap *DeclContext::CreateStoredDeclsMap(ASTContext &C) const {
1700  assert(!LookupPtr && "context already has a decls map");
1701  assert(getPrimaryContext() == this &&
1702         "creating decls map on non-primary context");
1703
1704  StoredDeclsMap *M;
1705  bool Dependent = isDependentContext();
1706  if (Dependent)
1707    M = new DependentStoredDeclsMap();
1708  else
1709    M = new StoredDeclsMap();
1710  M->Previous = C.LastSDM;
1711  C.LastSDM = llvm::PointerIntPair<StoredDeclsMap*,1>(M, Dependent);
1712  LookupPtr = M;
1713  return M;
1714}
1715
1716void ASTContext::ReleaseDeclContextMaps() {
1717  // It's okay to delete DependentStoredDeclsMaps via a StoredDeclsMap
1718  // pointer because the subclass doesn't add anything that needs to
1719  // be deleted.
1720  StoredDeclsMap::DestroyAll(LastSDM.getPointer(), LastSDM.getInt());
1721}
1722
1723void StoredDeclsMap::DestroyAll(StoredDeclsMap *Map, bool Dependent) {
1724  while (Map) {
1725    // Advance the iteration before we invalidate memory.
1726    llvm::PointerIntPair<StoredDeclsMap*,1> Next = Map->Previous;
1727
1728    if (Dependent)
1729      delete static_cast<DependentStoredDeclsMap*>(Map);
1730    else
1731      delete Map;
1732
1733    Map = Next.getPointer();
1734    Dependent = Next.getInt();
1735  }
1736}
1737
1738DependentDiagnostic *DependentDiagnostic::Create(ASTContext &C,
1739                                                 DeclContext *Parent,
1740                                           const PartialDiagnostic &PDiag) {
1741  assert(Parent->isDependentContext()
1742         && "cannot iterate dependent diagnostics of non-dependent context");
1743  Parent = Parent->getPrimaryContext();
1744  if (!Parent->LookupPtr)
1745    Parent->CreateStoredDeclsMap(C);
1746
1747  DependentStoredDeclsMap *Map =
1748      static_cast<DependentStoredDeclsMap *>(Parent->LookupPtr);
1749
1750  // Allocate the copy of the PartialDiagnostic via the ASTContext's
1751  // BumpPtrAllocator, rather than the ASTContext itself.
1752  PartialDiagnostic::Storage *DiagStorage = nullptr;
1753  if (PDiag.hasStorage())
1754    DiagStorage = new (C) PartialDiagnostic::Storage;
1755
1756  DependentDiagnostic *DD = new (C) DependentDiagnostic(PDiag, DiagStorage);
1757
1758  // TODO: Maybe we shouldn't reverse the order during insertion.
1759  DD->NextDiagnostic = Map->FirstDiagnostic;
1760  Map->FirstDiagnostic = DD;
1761
1762  return DD;
1763}
1764