Add the clang library to the repo (with some of my changes, too).

1 files changed, 1441 insertions, 0 deletions

diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
new file mode 100644
index 0000000..47a0d25
--- /dev/null
+++ b/clang/lib/AST/DeclBase.cpp
@@ -0,0 +1,1441 @@
+//===--- DeclBase.cpp - Declaration AST Node Implementation ---------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the Decl and DeclContext classes.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/DeclBase.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclContextInternals.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/DeclFriend.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/DeclTemplate.h"
+#include "clang/AST/DependentDiagnostic.h"
+#include "clang/AST/ExternalASTSource.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Type.h"
+#include "clang/AST/Stmt.h"
+#include "clang/AST/StmtCXX.h"
+#include "clang/AST/ASTMutationListener.h"
+#include "clang/Basic/TargetInfo.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+using namespace clang;
+
+//===----------------------------------------------------------------------===//
+//  Statistics
+//===----------------------------------------------------------------------===//
+
+#define DECL(DERIVED, BASE) static int n##DERIVED##s = 0;
+#define ABSTRACT_DECL(DECL)
+#include "clang/AST/DeclNodes.inc"
+
+void *Decl::AllocateDeserializedDecl(const ASTContext &Context, 
+                                     unsigned ID,
+                                     unsigned Size) {
+  // Allocate an extra 8 bytes worth of storage, which ensures that the
+  // resulting pointer will still be 8-byte aligned. 
+  void *Start = Context.Allocate(Size + 8);
+  void *Result = (char*)Start + 8;
+  
+  unsigned *PrefixPtr = (unsigned *)Result - 2;
+  
+  // Zero out the first 4 bytes; this is used to store the owning module ID.
+  PrefixPtr[0] = 0;
+  
+  // Store the global declaration ID in the second 4 bytes.
+  PrefixPtr[1] = ID;
+  
+  return Result;
+}
+
+const char *Decl::getDeclKindName() const {
+  switch (DeclKind) {
+  default: llvm_unreachable("Declaration not in DeclNodes.inc!");
+#define DECL(DERIVED, BASE) case DERIVED: return #DERIVED;
+#define ABSTRACT_DECL(DECL)
+#include "clang/AST/DeclNodes.inc"
+  }
+}
+
+void Decl::setInvalidDecl(bool Invalid) {
+  InvalidDecl = Invalid;
+  if (Invalid && !isa<ParmVarDecl>(this)) {
+    // Defensive maneuver for ill-formed code: we're likely not to make it to
+    // a point where we set the access specifier, so default it to "public"
+    // to avoid triggering asserts elsewhere in the front end. 
+    setAccess(AS_public);
+  }
+}
+
+const char *DeclContext::getDeclKindName() const {
+  switch (DeclKind) {
+  default: llvm_unreachable("Declaration context not in DeclNodes.inc!");
+#define DECL(DERIVED, BASE) case Decl::DERIVED: return #DERIVED;
+#define ABSTRACT_DECL(DECL)
+#include "clang/AST/DeclNodes.inc"
+  }
+}
+
+bool Decl::StatisticsEnabled = false;
+void Decl::EnableStatistics() {
+  StatisticsEnabled = true;
+}
+
+void Decl::PrintStats() {
+  llvm::errs() << "\n*** Decl Stats:\n";
+
+  int totalDecls = 0;
+#define DECL(DERIVED, BASE) totalDecls += n##DERIVED##s;
+#define ABSTRACT_DECL(DECL)
+#include "clang/AST/DeclNodes.inc"
+  llvm::errs() << "  " << totalDecls << " decls total.\n";
+
+  int totalBytes = 0;
+#define DECL(DERIVED, BASE)                                             \
+  if (n##DERIVED##s > 0) {                                              \
+    totalBytes += (int)(n##DERIVED##s * sizeof(DERIVED##Decl));         \
+    llvm::errs() << "    " << n##DERIVED##s << " " #DERIVED " decls, "  \
+                 << sizeof(DERIVED##Decl) << " each ("                  \
+                 << n##DERIVED##s * sizeof(DERIVED##Decl)               \
+                 << " bytes)\n";                                        \
+  }
+#define ABSTRACT_DECL(DECL)
+#include "clang/AST/DeclNodes.inc"
+
+  llvm::errs() << "Total bytes = " << totalBytes << "\n";
+}
+
+void Decl::add(Kind k) {
+  switch (k) {
+#define DECL(DERIVED, BASE) case DERIVED: ++n##DERIVED##s; break;
+#define ABSTRACT_DECL(DECL)
+#include "clang/AST/DeclNodes.inc"
+  }
+}
+
+bool Decl::isTemplateParameterPack() const {
+  if (const TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(this))
+    return TTP->isParameterPack();
+  if (const NonTypeTemplateParmDecl *NTTP
+                                = dyn_cast<NonTypeTemplateParmDecl>(this))
+    return NTTP->isParameterPack();
+  if (const TemplateTemplateParmDecl *TTP
+                                    = dyn_cast<TemplateTemplateParmDecl>(this))
+    return TTP->isParameterPack();
+  return false;
+}
+
+bool Decl::isParameterPack() const {
+  if (const ParmVarDecl *Parm = dyn_cast<ParmVarDecl>(this))
+    return Parm->isParameterPack();
+  
+  return isTemplateParameterPack();
+}
+
+bool Decl::isFunctionOrFunctionTemplate() const {
+  if (const UsingShadowDecl *UD = dyn_cast<UsingShadowDecl>(this))
+    return UD->getTargetDecl()->isFunctionOrFunctionTemplate();
+
+  return isa<FunctionDecl>(this) || isa<FunctionTemplateDecl>(this);
+}
+
+bool Decl::isTemplateDecl() const {
+  return isa<TemplateDecl>(this);
+}
+
+const DeclContext *Decl::getParentFunctionOrMethod() const {
+  for (const DeclContext *DC = getDeclContext();
+       DC && !DC->isTranslationUnit() && !DC->isNamespace(); 
+       DC = DC->getParent())
+    if (DC->isFunctionOrMethod())
+      return DC;
+
+  return 0;
+}
+
+
+//===----------------------------------------------------------------------===//
+// PrettyStackTraceDecl Implementation
+//===----------------------------------------------------------------------===//
+
+void PrettyStackTraceDecl::print(raw_ostream &OS) const {
+  SourceLocation TheLoc = Loc;
+  if (TheLoc.isInvalid() && TheDecl)
+    TheLoc = TheDecl->getLocation();
+
+  if (TheLoc.isValid()) {
+    TheLoc.print(OS, SM);
+    OS << ": ";
+  }
+
+  OS << Message;
+
+  if (const NamedDecl *DN = dyn_cast_or_null<NamedDecl>(TheDecl))
+    OS << " '" << DN->getQualifiedNameAsString() << '\'';
+  OS << '\n';
+}
+
+//===----------------------------------------------------------------------===//
+// Decl Implementation
+//===----------------------------------------------------------------------===//
+
+// Out-of-line virtual method providing a home for Decl.
+Decl::~Decl() { }
+
+void Decl::setDeclContext(DeclContext *DC) {
+  DeclCtx = DC;
+}
+
+void Decl::setLexicalDeclContext(DeclContext *DC) {
+  if (DC == getLexicalDeclContext())
+    return;
+
+  if (isInSemaDC()) {
+    setDeclContextsImpl(getDeclContext(), DC, getASTContext());
+  } else {
+    getMultipleDC()->LexicalDC = DC;
+  }
+}
+
+void Decl::setDeclContextsImpl(DeclContext *SemaDC, DeclContext *LexicalDC,
+                               ASTContext &Ctx) {
+  if (SemaDC == LexicalDC) {
+    DeclCtx = SemaDC;
+  } else {
+    Decl::MultipleDC *MDC = new (Ctx) Decl::MultipleDC();
+    MDC->SemanticDC = SemaDC;
+    MDC->LexicalDC = LexicalDC;
+    DeclCtx = MDC;
+  }
+}
+
+bool Decl::isInAnonymousNamespace() const {
+  const DeclContext *DC = getDeclContext();
+  do {
+    if (const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(DC))
+      if (ND->isAnonymousNamespace())
+        return true;
+  } while ((DC = DC->getParent()));
+
+  return false;
+}
+
+TranslationUnitDecl *Decl::getTranslationUnitDecl() {
+  if (TranslationUnitDecl *TUD = dyn_cast<TranslationUnitDecl>(this))
+    return TUD;
+
+  DeclContext *DC = getDeclContext();
+  assert(DC && "This decl is not contained in a translation unit!");
+
+  while (!DC->isTranslationUnit()) {
+    DC = DC->getParent();
+    assert(DC && "This decl is not contained in a translation unit!");
+  }
+
+  return cast<TranslationUnitDecl>(DC);
+}
+
+ASTContext &Decl::getASTContext() const {
+  return getTranslationUnitDecl()->getASTContext();
+}
+
+ASTMutationListener *Decl::getASTMutationListener() const {
+  return getASTContext().getASTMutationListener();
+}
+
+bool Decl::isUsed(bool CheckUsedAttr) const { 
+  if (Used)
+    return true;
+  
+  // Check for used attribute.
+  if (CheckUsedAttr && hasAttr<UsedAttr>())
+    return true;
+  
+  // Check redeclarations for used attribute.
+  for (redecl_iterator I = redecls_begin(), E = redecls_end(); I != E; ++I) {
+    if ((CheckUsedAttr && I->hasAttr<UsedAttr>()) || I->Used)
+      return true;
+  }
+  
+  return false; 
+}
+
+bool Decl::isReferenced() const { 
+  if (Referenced)
+    return true;
+
+  // Check redeclarations.
+  for (redecl_iterator I = redecls_begin(), E = redecls_end(); I != E; ++I)
+    if (I->Referenced)
+      return true;
+
+  return false; 
+}
+
+/// \brief Determine the availability of the given declaration based on
+/// the target platform.
+///
+/// When it returns an availability result other than \c AR_Available,
+/// if the \p Message parameter is non-NULL, it will be set to a
+/// string describing why the entity is unavailable.
+///
+/// FIXME: Make these strings localizable, since they end up in
+/// diagnostics.
+static AvailabilityResult CheckAvailability(ASTContext &Context,
+                                            const AvailabilityAttr *A,
+                                            std::string *Message) {
+  StringRef TargetPlatform = Context.getTargetInfo().getPlatformName();
+  StringRef PrettyPlatformName
+    = AvailabilityAttr::getPrettyPlatformName(TargetPlatform);
+  if (PrettyPlatformName.empty())
+    PrettyPlatformName = TargetPlatform;
+
+  VersionTuple TargetMinVersion = Context.getTargetInfo().getPlatformMinVersion();
+  if (TargetMinVersion.empty())
+    return AR_Available;
+
+  // Match the platform name.
+  if (A->getPlatform()->getName() != TargetPlatform)
+    return AR_Available;
+  
+  std::string HintMessage;
+  if (!A->getMessage().empty()) {
+    HintMessage = " - ";
+    HintMessage += A->getMessage();
+  }
+  
+  // Make sure that this declaration has not been marked 'unavailable'.
+  if (A->getUnavailable()) {
+    if (Message) {
+      Message->clear();
+      llvm::raw_string_ostream Out(*Message);
+      Out << "not available on " << PrettyPlatformName 
+          << HintMessage;
+    }
+
+    return AR_Unavailable;
+  }
+
+  // Make sure that this declaration has already been introduced.
+  if (!A->getIntroduced().empty() && 
+      TargetMinVersion < A->getIntroduced()) {
+    if (Message) {
+      Message->clear();
+      llvm::raw_string_ostream Out(*Message);
+      Out << "introduced in " << PrettyPlatformName << ' ' 
+          << A->getIntroduced() << HintMessage;
+    }
+
+    return AR_NotYetIntroduced;
+  }
+
+  // Make sure that this declaration hasn't been obsoleted.
+  if (!A->getObsoleted().empty() && TargetMinVersion >= A->getObsoleted()) {
+    if (Message) {
+      Message->clear();
+      llvm::raw_string_ostream Out(*Message);
+      Out << "obsoleted in " << PrettyPlatformName << ' ' 
+          << A->getObsoleted() << HintMessage;
+    }
+    
+    return AR_Unavailable;
+  }
+
+  // Make sure that this declaration hasn't been deprecated.
+  if (!A->getDeprecated().empty() && TargetMinVersion >= A->getDeprecated()) {
+    if (Message) {
+      Message->clear();
+      llvm::raw_string_ostream Out(*Message);
+      Out << "first deprecated in " << PrettyPlatformName << ' '
+          << A->getDeprecated() << HintMessage;
+    }
+    
+    return AR_Deprecated;
+  }
+
+  return AR_Available;
+}
+
+AvailabilityResult Decl::getAvailability(std::string *Message) const {
+  AvailabilityResult Result = AR_Available;
+  std::string ResultMessage;
+
+  for (attr_iterator A = attr_begin(), AEnd = attr_end(); A != AEnd; ++A) {
+    if (DeprecatedAttr *Deprecated = dyn_cast<DeprecatedAttr>(*A)) {
+      if (Result >= AR_Deprecated)
+        continue;
+
+      if (Message)
+        ResultMessage = Deprecated->getMessage();
+
+      Result = AR_Deprecated;
+      continue;
+    }
+
+    if (UnavailableAttr *Unavailable = dyn_cast<UnavailableAttr>(*A)) {
+      if (Message)
+        *Message = Unavailable->getMessage();
+      return AR_Unavailable;
+    }
+
+    if (AvailabilityAttr *Availability = dyn_cast<AvailabilityAttr>(*A)) {
+      AvailabilityResult AR = CheckAvailability(getASTContext(), Availability,
+                                                Message);
+
+      if (AR == AR_Unavailable)
+        return AR_Unavailable;
+
+      if (AR > Result) {
+        Result = AR;
+        if (Message)
+          ResultMessage.swap(*Message);
+      }
+      continue;
+    }
+  }
+
+  if (Message)
+    Message->swap(ResultMessage);
+  return Result;
+}
+
+bool Decl::canBeWeakImported(bool &IsDefinition) const {
+  IsDefinition = false;
+  if (const VarDecl *Var = dyn_cast<VarDecl>(this)) {
+    if (!Var->hasExternalStorage() || Var->getInit()) {
+      IsDefinition = true;
+      return false;
+    }
+  } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(this)) {
+    if (FD->hasBody()) {
+      IsDefinition = true;
+      return false;
+    }
+  } else if (isa<ObjCPropertyDecl>(this) || isa<ObjCMethodDecl>(this))
+    return false;
+  else if (!(getASTContext().getLangOpts().ObjCNonFragileABI &&
+             isa<ObjCInterfaceDecl>(this)))
+    return false;
+
+  return true;
+}
+
+bool Decl::isWeakImported() const {
+  bool IsDefinition;
+  if (!canBeWeakImported(IsDefinition))
+    return false;
+
+  for (attr_iterator A = attr_begin(), AEnd = attr_end(); A != AEnd; ++A) {
+    if (isa<WeakImportAttr>(*A))
+      return true;
+
+    if (AvailabilityAttr *Availability = dyn_cast<AvailabilityAttr>(*A)) {
+      if (CheckAvailability(getASTContext(), Availability, 0) 
+                                                         == AR_NotYetIntroduced)
+        return true;
+    }
+  }
+
+  return false;
+}
+
+unsigned Decl::getIdentifierNamespaceForKind(Kind DeclKind) {
+  switch (DeclKind) {
+    case Function:
+    case CXXMethod:
+    case CXXConstructor:
+    case CXXDestructor:
+    case CXXConversion:
+    case EnumConstant:
+    case Var:
+    case ImplicitParam:
+    case ParmVar:
+    case NonTypeTemplateParm:
+    case ObjCMethod:
+    case ObjCProperty:
+      return IDNS_Ordinary;
+    case Label:
+      return IDNS_Label;
+    case IndirectField:
+      return IDNS_Ordinary | IDNS_Member;
+
+    case ObjCCompatibleAlias:
+    case ObjCInterface:
+      return IDNS_Ordinary | IDNS_Type;
+
+    case Typedef:
+    case TypeAlias:
+    case TypeAliasTemplate:
+    case UnresolvedUsingTypename:
+    case TemplateTypeParm:
+      return IDNS_Ordinary | IDNS_Type;
+
+    case UsingShadow:
+      return 0; // we'll actually overwrite this later
+
+    case UnresolvedUsingValue:
+      return IDNS_Ordinary | IDNS_Using;
+
+    case Using:
+      return IDNS_Using;
+
+    case ObjCProtocol:
+      return IDNS_ObjCProtocol;
+
+    case Field:
+    case ObjCAtDefsField:
+    case ObjCIvar:
+      return IDNS_Member;
+
+    case Record:
+    case CXXRecord:
+    case Enum:
+      return IDNS_Tag | IDNS_Type;
+
+    case Namespace:
+    case NamespaceAlias:
+      return IDNS_Namespace;
+
+    case FunctionTemplate:
+      return IDNS_Ordinary;
+
+    case ClassTemplate:
+    case TemplateTemplateParm:
+      return IDNS_Ordinary | IDNS_Tag | IDNS_Type;
+
+    // Never have names.
+    case Friend:
+    case FriendTemplate:
+    case AccessSpec:
+    case LinkageSpec:
+    case FileScopeAsm:
+    case StaticAssert:
+    case ObjCPropertyImpl:
+    case Block:
+    case TranslationUnit:
+
+    case UsingDirective:
+    case ClassTemplateSpecialization:
+    case ClassTemplatePartialSpecialization:
+    case ClassScopeFunctionSpecialization:
+    case ObjCImplementation:
+    case ObjCCategory:
+    case ObjCCategoryImpl:
+    case Import:
+      // Never looked up by name.
+      return 0;
+  }
+
+  llvm_unreachable("Invalid DeclKind!");
+}
+
+void Decl::setAttrsImpl(const AttrVec &attrs, ASTContext &Ctx) {
+  assert(!HasAttrs && "Decl already contains attrs.");
+
+  AttrVec &AttrBlank = Ctx.getDeclAttrs(this);
+  assert(AttrBlank.empty() && "HasAttrs was wrong?");
+
+  AttrBlank = attrs;
+  HasAttrs = true;
+}
+
+void Decl::dropAttrs() {
+  if (!HasAttrs) return;
+
+  HasAttrs = false;
+  getASTContext().eraseDeclAttrs(this);
+}
+
+const AttrVec &Decl::getAttrs() const {
+  assert(HasAttrs && "No attrs to get!");
+  return getASTContext().getDeclAttrs(this);
+}
+
+void Decl::swapAttrs(Decl *RHS) {
+  bool HasLHSAttr = this->HasAttrs;
+  bool HasRHSAttr = RHS->HasAttrs;
+
+  // Usually, neither decl has attrs, nothing to do.
+  if (!HasLHSAttr && !HasRHSAttr) return;
+
+  // If 'this' has no attrs, swap the other way.
+  if (!HasLHSAttr)
+    return RHS->swapAttrs(this);
+
+  ASTContext &Context = getASTContext();
+
+  // Handle the case when both decls have attrs.
+  if (HasRHSAttr) {
+    std::swap(Context.getDeclAttrs(this), Context.getDeclAttrs(RHS));
+    return;
+  }
+
+  // Otherwise, LHS has an attr and RHS doesn't.
+  Context.getDeclAttrs(RHS) = Context.getDeclAttrs(this);
+  Context.eraseDeclAttrs(this);
+  this->HasAttrs = false;
+  RHS->HasAttrs = true;
+}
+
+Decl *Decl::castFromDeclContext (const DeclContext *D) {
+  Decl::Kind DK = D->getDeclKind();
+  switch(DK) {
+#define DECL(NAME, BASE)
+#define DECL_CONTEXT(NAME) \
+    case Decl::NAME:       \
+      return static_cast<NAME##Decl*>(const_cast<DeclContext*>(D));
+#define DECL_CONTEXT_BASE(NAME)
+#include "clang/AST/DeclNodes.inc"
+    default:
+#define DECL(NAME, BASE)
+#define DECL_CONTEXT_BASE(NAME)                  \
+      if (DK >= first##NAME && DK <= last##NAME) \
+        return static_cast<NAME##Decl*>(const_cast<DeclContext*>(D));
+#include "clang/AST/DeclNodes.inc"
+      llvm_unreachable("a decl that inherits DeclContext isn't handled");
+  }
+}
+
+DeclContext *Decl::castToDeclContext(const Decl *D) {
+  Decl::Kind DK = D->getKind();
+  switch(DK) {
+#define DECL(NAME, BASE)
+#define DECL_CONTEXT(NAME) \
+    case Decl::NAME:       \
+      return static_cast<NAME##Decl*>(const_cast<Decl*>(D));
+#define DECL_CONTEXT_BASE(NAME)
+#include "clang/AST/DeclNodes.inc"
+    default:
+#define DECL(NAME, BASE)
+#define DECL_CONTEXT_BASE(NAME)                                   \
+      if (DK >= first##NAME && DK <= last##NAME)                  \
+        return static_cast<NAME##Decl*>(const_cast<Decl*>(D));
+#include "clang/AST/DeclNodes.inc"
+      llvm_unreachable("a decl that inherits DeclContext isn't handled");
+  }
+}
+
+SourceLocation Decl::getBodyRBrace() const {
+  // Special handling of FunctionDecl to avoid de-serializing the body from PCH.
+  // FunctionDecl stores EndRangeLoc for this purpose.
+  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(this)) {
+    const FunctionDecl *Definition;
+    if (FD->hasBody(Definition))
+      return Definition->getSourceRange().getEnd();
+    return SourceLocation();
+  }
+
+  if (Stmt *Body = getBody())
+    return Body->getSourceRange().getEnd();
+
+  return SourceLocation();
+}
+
+void Decl::CheckAccessDeclContext() const {
+#ifndef NDEBUG
+  // Suppress this check if any of the following hold:
+  // 1. this is the translation unit (and thus has no parent)
+  // 2. this is a template parameter (and thus doesn't belong to its context)
+  // 3. this is a non-type template parameter
+  // 4. the context is not a record
+  // 5. it's invalid
+  // 6. it's a C++0x static_assert.
+  if (isa<TranslationUnitDecl>(this) ||
+      isa<TemplateTypeParmDecl>(this) ||
+      isa<NonTypeTemplateParmDecl>(this) ||
+      !isa<CXXRecordDecl>(getDeclContext()) ||
+      isInvalidDecl() ||
+      isa<StaticAssertDecl>(this) ||
+      // FIXME: a ParmVarDecl can have ClassTemplateSpecialization
+      // as DeclContext (?).
+      isa<ParmVarDecl>(this) ||
+      // FIXME: a ClassTemplateSpecialization or CXXRecordDecl can have
+      // AS_none as access specifier.
+      isa<CXXRecordDecl>(this) ||
+      isa<ClassScopeFunctionSpecializationDecl>(this))
+    return;
+
+  assert(Access != AS_none &&
+         "Access specifier is AS_none inside a record decl");
+#endif
+}
+
+DeclContext *Decl::getNonClosureContext() {
+  return getDeclContext()->getNonClosureAncestor();
+}
+
+DeclContext *DeclContext::getNonClosureAncestor() {
+  DeclContext *DC = this;
+
+  // This is basically "while (DC->isClosure()) DC = DC->getParent();"
+  // except that it's significantly more efficient to cast to a known
+  // decl type and call getDeclContext() than to call getParent().
+  while (isa<BlockDecl>(DC))
+    DC = cast<BlockDecl>(DC)->getDeclContext();
+
+  assert(!DC->isClosure());
+  return DC;
+}
+
+//===----------------------------------------------------------------------===//
+// DeclContext Implementation
+//===----------------------------------------------------------------------===//
+
+bool DeclContext::classof(const Decl *D) {
+  switch (D->getKind()) {
+#define DECL(NAME, BASE)
+#define DECL_CONTEXT(NAME) case Decl::NAME:
+#define DECL_CONTEXT_BASE(NAME)
+#include "clang/AST/DeclNodes.inc"
+      return true;
+    default:
+#define DECL(NAME, BASE)
+#define DECL_CONTEXT_BASE(NAME)                 \
+      if (D->getKind() >= Decl::first##NAME &&  \
+          D->getKind() <= Decl::last##NAME)     \
+        return true;
+#include "clang/AST/DeclNodes.inc"
+      return false;
+  }
+}
+
+DeclContext::~DeclContext() { }
+
+/// \brief Find the parent context of this context that will be
+/// used for unqualified name lookup.
+///
+/// Generally, the parent lookup context is the semantic context. However, for
+/// a friend function the parent lookup context is the lexical context, which
+/// is the class in which the friend is declared.
+DeclContext *DeclContext::getLookupParent() {
+  // FIXME: Find a better way to identify friends
+  if (isa<FunctionDecl>(this))
+    if (getParent()->getRedeclContext()->isFileContext() &&
+        getLexicalParent()->getRedeclContext()->isRecord())
+      return getLexicalParent();
+  
+  return getParent();
+}
+
+bool DeclContext::isInlineNamespace() const {
+  return isNamespace() &&
+         cast<NamespaceDecl>(this)->isInline();
+}
+
+bool DeclContext::isDependentContext() const {
+  if (isFileContext())
+    return false;
+
+  if (isa<ClassTemplatePartialSpecializationDecl>(this))
+    return true;
+
+  if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(this)) {
+    if (Record->getDescribedClassTemplate())
+      return true;
+    
+    if (Record->isDependentLambda())
+      return true;
+  }
+  
+  if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(this)) {
+    if (Function->getDescribedFunctionTemplate())
+      return true;
+
+    // Friend function declarations are dependent if their *lexical*
+    // context is dependent.
+    if (cast<Decl>(this)->getFriendObjectKind())
+      return getLexicalParent()->isDependentContext();
+  }
+
+  return getParent() && getParent()->isDependentContext();
+}
+
+bool DeclContext::isTransparentContext() const {
+  if (DeclKind == Decl::Enum)
+    return !cast<EnumDecl>(this)->isScoped();
+  else if (DeclKind == Decl::LinkageSpec)
+    return true;
+
+  return false;
+}
+
+bool DeclContext::isExternCContext() const {
+  const DeclContext *DC = this;
+  while (DC->DeclKind != Decl::TranslationUnit) {
+    if (DC->DeclKind == Decl::LinkageSpec)
+      return cast<LinkageSpecDecl>(DC)->getLanguage()
+        == LinkageSpecDecl::lang_c;
+    DC = DC->getParent();
+  }
+  return false;
+}
+
+bool DeclContext::Encloses(const DeclContext *DC) const {
+  if (getPrimaryContext() != this)
+    return getPrimaryContext()->Encloses(DC);
+
+  for (; DC; DC = DC->getParent())
+    if (DC->getPrimaryContext() == this)
+      return true;
+  return false;
+}
+
+DeclContext *DeclContext::getPrimaryContext() {
+  switch (DeclKind) {
+  case Decl::TranslationUnit:
+  case Decl::LinkageSpec:
+  case Decl::Block:
+    // There is only one DeclContext for these entities.
+    return this;
+
+  case Decl::Namespace:
+    // The original namespace is our primary context.
+    return static_cast<NamespaceDecl*>(this)->getOriginalNamespace();
+
+  case Decl::ObjCMethod:
+    return this;
+
+  case Decl::ObjCInterface:
+    if (ObjCInterfaceDecl *Def = cast<ObjCInterfaceDecl>(this)->getDefinition())
+      return Def;
+      
+    return this;
+      
+  case Decl::ObjCProtocol:
+    if (ObjCProtocolDecl *Def = cast<ObjCProtocolDecl>(this)->getDefinition())
+      return Def;
+    
+    return this;
+      
+  case Decl::ObjCCategory:
+    return this;
+
+  case Decl::ObjCImplementation:
+  case Decl::ObjCCategoryImpl:
+    return this;
+
+  default:
+    if (DeclKind >= Decl::firstTag && DeclKind <= Decl::lastTag) {
+      // If this is a tag type that has a definition or is currently
+      // being defined, that definition is our primary context.
+      TagDecl *Tag = cast<TagDecl>(this);
+      assert(isa<TagType>(Tag->TypeForDecl) ||
+             isa<InjectedClassNameType>(Tag->TypeForDecl));
+
+      if (TagDecl *Def = Tag->getDefinition())
+        return Def;
+
+      if (!isa<InjectedClassNameType>(Tag->TypeForDecl)) {
+        const TagType *TagTy = cast<TagType>(Tag->TypeForDecl);
+        if (TagTy->isBeingDefined())
+          // FIXME: is it necessarily being defined in the decl
+          // that owns the type?
+          return TagTy->getDecl();
+      }
+
+      return Tag;
+    }
+
+    assert(DeclKind >= Decl::firstFunction && DeclKind <= Decl::lastFunction &&
+          "Unknown DeclContext kind");
+    return this;
+  }
+}
+
+void 
+DeclContext::collectAllContexts(llvm::SmallVectorImpl<DeclContext *> &Contexts){
+  Contexts.clear();
+  
+  if (DeclKind != Decl::Namespace) {
+    Contexts.push_back(this);
+    return;
+  }
+  
+  NamespaceDecl *Self = static_cast<NamespaceDecl *>(this);
+  for (NamespaceDecl *N = Self->getMostRecentDecl(); N;
+       N = N->getPreviousDecl())
+    Contexts.push_back(N);
+  
+  std::reverse(Contexts.begin(), Contexts.end());
+}
+
+std::pair<Decl *, Decl *>
+DeclContext::BuildDeclChain(ArrayRef<Decl*> Decls,
+                            bool FieldsAlreadyLoaded) {
+  // Build up a chain of declarations via the Decl::NextInContextAndBits field.
+  Decl *FirstNewDecl = 0;
+  Decl *PrevDecl = 0;
+  for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
+    if (FieldsAlreadyLoaded && isa<FieldDecl>(Decls[I]))
+      continue;
+
+    Decl *D = Decls[I];
+    if (PrevDecl)
+      PrevDecl->NextInContextAndBits.setPointer(D);
+    else
+      FirstNewDecl = D;
+
+    PrevDecl = D;
+  }
+
+  return std::make_pair(FirstNewDecl, PrevDecl);
+}
+
+/// \brief Load the declarations within this lexical storage from an
+/// external source.
+void
+DeclContext::LoadLexicalDeclsFromExternalStorage() const {
+  ExternalASTSource *Source = getParentASTContext().getExternalSource();
+  assert(hasExternalLexicalStorage() && Source && "No external storage?");
+
+  // Notify that we have a DeclContext that is initializing.
+  ExternalASTSource::Deserializing ADeclContext(Source);
+  
+  // Load the external declarations, if any.
+  SmallVector<Decl*, 64> Decls;
+  ExternalLexicalStorage = false;
+  switch (Source->FindExternalLexicalDecls(this, Decls)) {
+  case ELR_Success:
+    break;
+    
+  case ELR_Failure:
+  case ELR_AlreadyLoaded:
+    return;
+  }
+
+  if (Decls.empty())
+    return;
+
+  // We may have already loaded just the fields of this record, in which case
+  // we need to ignore them.
+  bool FieldsAlreadyLoaded = false;
+  if (const RecordDecl *RD = dyn_cast<RecordDecl>(this))
+    FieldsAlreadyLoaded = RD->LoadedFieldsFromExternalStorage;
+  
+  // Splice the newly-read declarations into the beginning of the list
+  // of declarations.
+  Decl *ExternalFirst, *ExternalLast;
+  llvm::tie(ExternalFirst, ExternalLast) = BuildDeclChain(Decls,
+                                                          FieldsAlreadyLoaded);
+  ExternalLast->NextInContextAndBits.setPointer(FirstDecl);
+  FirstDecl = ExternalFirst;
+  if (!LastDecl)
+    LastDecl = ExternalLast;
+}
+
+DeclContext::lookup_result
+ExternalASTSource::SetNoExternalVisibleDeclsForName(const DeclContext *DC,
+                                                    DeclarationName Name) {
+  ASTContext &Context = DC->getParentASTContext();
+  StoredDeclsMap *Map;
+  if (!(Map = DC->LookupPtr.getPointer()))
+    Map = DC->CreateStoredDeclsMap(Context);
+
+  StoredDeclsList &List = (*Map)[Name];
+  assert(List.isNull());
+  (void) List;
+
+  return DeclContext::lookup_result();
+}
+
+DeclContext::lookup_result
+ExternalASTSource::SetExternalVisibleDeclsForName(const DeclContext *DC,
+                                                  DeclarationName Name,
+                                                  ArrayRef<NamedDecl*> Decls) {
+  ASTContext &Context = DC->getParentASTContext();;
+
+  StoredDeclsMap *Map;
+  if (!(Map = DC->LookupPtr.getPointer()))
+    Map = DC->CreateStoredDeclsMap(Context);
+
+  StoredDeclsList &List = (*Map)[Name];
+  for (ArrayRef<NamedDecl*>::iterator
+         I = Decls.begin(), E = Decls.end(); I != E; ++I) {
+    if (List.isNull())
+      List.setOnlyValue(*I);
+    else
+      List.AddSubsequentDecl(*I);
+  }
+
+  return List.getLookupResult();
+}
+
+DeclContext::decl_iterator DeclContext::noload_decls_begin() const {
+  return decl_iterator(FirstDecl);
+}
+
+DeclContext::decl_iterator DeclContext::noload_decls_end() const {
+  return decl_iterator();
+}
+
+DeclContext::decl_iterator DeclContext::decls_begin() const {
+  if (hasExternalLexicalStorage())
+    LoadLexicalDeclsFromExternalStorage();
+
+  return decl_iterator(FirstDecl);
+}
+
+DeclContext::decl_iterator DeclContext::decls_end() const {
+  if (hasExternalLexicalStorage())
+    LoadLexicalDeclsFromExternalStorage();
+
+  return decl_iterator();
+}
+
+bool DeclContext::decls_empty() const {
+  if (hasExternalLexicalStorage())
+    LoadLexicalDeclsFromExternalStorage();
+
+  return !FirstDecl;
+}
+
+void DeclContext::removeDecl(Decl *D) {
+  assert(D->getLexicalDeclContext() == this &&
+         "decl being removed from non-lexical context");
+  assert((D->NextInContextAndBits.getPointer() || D == LastDecl) &&
+         "decl is not in decls list");
+
+  // Remove D from the decl chain.  This is O(n) but hopefully rare.
+  if (D == FirstDecl) {
+    if (D == LastDecl)
+      FirstDecl = LastDecl = 0;
+    else
+      FirstDecl = D->NextInContextAndBits.getPointer();
+  } else {
+    for (Decl *I = FirstDecl; true; I = I->NextInContextAndBits.getPointer()) {
+      assert(I && "decl not found in linked list");
+      if (I->NextInContextAndBits.getPointer() == D) {
+        I->NextInContextAndBits.setPointer(D->NextInContextAndBits.getPointer());
+        if (D == LastDecl) LastDecl = I;
+        break;
+      }
+    }
+  }
+  
+  // Mark that D is no longer in the decl chain.
+  D->NextInContextAndBits.setPointer(0);
+
+  // Remove D from the lookup table if necessary.
+  if (isa<NamedDecl>(D)) {
+    NamedDecl *ND = cast<NamedDecl>(D);
+
+    // Remove only decls that have a name
+    if (!ND->getDeclName()) return;
+
+    StoredDeclsMap *Map = getPrimaryContext()->LookupPtr.getPointer();
+    if (!Map) return;
+
+    StoredDeclsMap::iterator Pos = Map->find(ND->getDeclName());
+    assert(Pos != Map->end() && "no lookup entry for decl");
+    if (Pos->second.getAsVector() || Pos->second.getAsDecl() == ND)
+      Pos->second.remove(ND);
+  }
+}
+
+void DeclContext::addHiddenDecl(Decl *D) {
+  assert(D->getLexicalDeclContext() == this &&
+         "Decl inserted into wrong lexical context");
+  assert(!D->getNextDeclInContext() && D != LastDecl &&
+         "Decl already inserted into a DeclContext");
+
+  if (FirstDecl) {
+    LastDecl->NextInContextAndBits.setPointer(D);
+    LastDecl = D;
+  } else {
+    FirstDecl = LastDecl = D;
+  }
+
+  // Notify a C++ record declaration that we've added a member, so it can
+  // update it's class-specific state.
+  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(this))
+    Record->addedMember(D);
+
+  // If this is a newly-created (not de-serialized) import declaration, wire
+  // it in to the list of local import declarations.
+  if (!D->isFromASTFile()) {
+    if (ImportDecl *Import = dyn_cast<ImportDecl>(D))
+      D->getASTContext().addedLocalImportDecl(Import);
+  }
+}
+
+void DeclContext::addDecl(Decl *D) {
+  addHiddenDecl(D);
+
+  if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
+    ND->getDeclContext()->getPrimaryContext()->
+        makeDeclVisibleInContextWithFlags(ND, false, true);
+}
+
+void DeclContext::addDeclInternal(Decl *D) {
+  addHiddenDecl(D);
+
+  if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
+    ND->getDeclContext()->getPrimaryContext()->
+        makeDeclVisibleInContextWithFlags(ND, true, true);
+}
+
+/// shouldBeHidden - Determine whether a declaration which was declared
+/// within its semantic context should be invisible to qualified name lookup.
+static bool shouldBeHidden(NamedDecl *D) {
+  // Skip unnamed declarations.
+  if (!D->getDeclName())
+    return true;
+
+  // Skip entities that can't be found by name lookup into a particular
+  // context.
+  if ((D->getIdentifierNamespace() == 0 && !isa<UsingDirectiveDecl>(D)) ||
+      D->isTemplateParameter())
+    return true;
+
+  // Skip template specializations.
+  // FIXME: This feels like a hack. Should DeclarationName support
+  // template-ids, or is there a better way to keep specializations
+  // from being visible?
+  if (isa<ClassTemplateSpecializationDecl>(D))
+    return true;
+  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
+    if (FD->isFunctionTemplateSpecialization())
+      return true;
+
+  return false;
+}
+
+/// buildLookup - Build the lookup data structure with all of the
+/// declarations in this DeclContext (and any other contexts linked
+/// to it or transparent contexts nested within it) and return it.
+StoredDeclsMap *DeclContext::buildLookup() {
+  assert(this == getPrimaryContext() && "buildLookup called on non-primary DC");
+
+  if (!LookupPtr.getInt())
+    return LookupPtr.getPointer();
+
+  llvm::SmallVector<DeclContext *, 2> Contexts;
+  collectAllContexts(Contexts);
+  for (unsigned I = 0, N = Contexts.size(); I != N; ++I)
+    buildLookupImpl(Contexts[I]);
+
+  // We no longer have any lazy decls.
+  LookupPtr.setInt(false);
+  return LookupPtr.getPointer();
+}
+
+/// buildLookupImpl - Build part of the lookup data structure for the
+/// declarations contained within DCtx, which will either be this
+/// DeclContext, a DeclContext linked to it, or a transparent context
+/// nested within it.
+void DeclContext::buildLookupImpl(DeclContext *DCtx) {
+  for (decl_iterator I = DCtx->decls_begin(), E = DCtx->decls_end();
+       I != E; ++I) {
+    Decl *D = *I;
+
+    // Insert this declaration into the lookup structure, but only if
+    // it's semantically within its decl context. Any other decls which
+    // should be found in this context are added eagerly.
+    if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
+      if (ND->getDeclContext() == DCtx && !shouldBeHidden(ND))
+        makeDeclVisibleInContextImpl(ND, false);
+
+    // If this declaration is itself a transparent declaration context
+    // or inline namespace, add the members of this declaration of that
+    // context (recursively).
+    if (DeclContext *InnerCtx = dyn_cast<DeclContext>(D))
+      if (InnerCtx->isTransparentContext() || InnerCtx->isInlineNamespace())
+        buildLookupImpl(InnerCtx);
+  }
+}
+
+DeclContext::lookup_result
+DeclContext::lookup(DeclarationName Name) {
+  assert(DeclKind != Decl::LinkageSpec &&
+         "Should not perform lookups into linkage specs!");
+
+  DeclContext *PrimaryContext = getPrimaryContext();
+  if (PrimaryContext != this)
+    return PrimaryContext->lookup(Name);
+
+  if (hasExternalVisibleStorage()) {
+    // If a PCH has a result for this name, and we have a local declaration, we
+    // will have imported the PCH result when adding the local declaration.
+    // FIXME: For modules, we could have had more declarations added by module
+    // imoprts since we saw the declaration of the local name.
+    if (StoredDeclsMap *Map = LookupPtr.getPointer()) {
+      StoredDeclsMap::iterator I = Map->find(Name);
+      if (I != Map->end())
+        return I->second.getLookupResult();
+    }
+
+    ExternalASTSource *Source = getParentASTContext().getExternalSource();
+    return Source->FindExternalVisibleDeclsByName(this, Name);
+  }
+
+  StoredDeclsMap *Map = LookupPtr.getPointer();
+  if (LookupPtr.getInt())
+    Map = buildLookup();
+
+  if (!Map)
+    return lookup_result(lookup_iterator(0), lookup_iterator(0));
+
+  StoredDeclsMap::iterator I = Map->find(Name);
+  if (I == Map->end())
+    return lookup_result(lookup_iterator(0), lookup_iterator(0));
+
+  return I->second.getLookupResult();
+}
+
+DeclContext::lookup_const_result
+DeclContext::lookup(DeclarationName Name) const {
+  return const_cast<DeclContext*>(this)->lookup(Name);
+}
+
+void DeclContext::localUncachedLookup(DeclarationName Name, 
+                                  llvm::SmallVectorImpl<NamedDecl *> &Results) {
+  Results.clear();
+  
+  // If there's no external storage, just perform a normal lookup and copy
+  // the results.
+  if (!hasExternalVisibleStorage() && !hasExternalLexicalStorage()) {
+    lookup_result LookupResults = lookup(Name);
+    Results.insert(Results.end(), LookupResults.first, LookupResults.second);
+    return;
+  }
+
+  // If we have a lookup table, check there first. Maybe we'll get lucky.
+  if (StoredDeclsMap *Map = LookupPtr.getPointer()) {
+    StoredDeclsMap::iterator Pos = Map->find(Name);
+    if (Pos != Map->end()) {
+      Results.insert(Results.end(),
+                     Pos->second.getLookupResult().first,
+                     Pos->second.getLookupResult().second);
+      return;
+    }
+  }
+  
+  // Slow case: grovel through the declarations in our chain looking for 
+  // matches.
+  for (Decl *D = FirstDecl; D; D = D->getNextDeclInContext()) {
+    if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
+      if (ND->getDeclName() == Name)
+        Results.push_back(ND);
+  }
+}
+
+DeclContext *DeclContext::getRedeclContext() {
+  DeclContext *Ctx = this;
+  // Skip through transparent contexts.
+  while (Ctx->isTransparentContext())
+    Ctx = Ctx->getParent();
+  return Ctx;
+}
+
+DeclContext *DeclContext::getEnclosingNamespaceContext() {
+  DeclContext *Ctx = this;
+  // Skip through non-namespace, non-translation-unit contexts.
+  while (!Ctx->isFileContext())
+    Ctx = Ctx->getParent();
+  return Ctx->getPrimaryContext();
+}
+
+bool DeclContext::InEnclosingNamespaceSetOf(const DeclContext *O) const {
+  // For non-file contexts, this is equivalent to Equals.
+  if (!isFileContext())
+    return O->Equals(this);
+
+  do {
+    if (O->Equals(this))
+      return true;
+
+    const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(O);
+    if (!NS || !NS->isInline())
+      break;
+    O = NS->getParent();
+  } while (O);
+
+  return false;
+}
+
+void DeclContext::makeDeclVisibleInContext(NamedDecl *D) {
+  DeclContext *PrimaryDC = this->getPrimaryContext();
+  DeclContext *DeclDC = D->getDeclContext()->getPrimaryContext();
+  // If the decl is being added outside of its semantic decl context, we
+  // need to ensure that we eagerly build the lookup information for it.
+  PrimaryDC->makeDeclVisibleInContextWithFlags(D, false, PrimaryDC == DeclDC);
+}
+
+void DeclContext::makeDeclVisibleInContextWithFlags(NamedDecl *D, bool Internal,
+                                                    bool Recoverable) {
+  assert(this == getPrimaryContext() && "expected a primary DC");
+
+  // Skip declarations within functions.
+  // FIXME: We shouldn't need to build lookup tables for function declarations
+  // ever, and we can't do so correctly because we can't model the nesting of
+  // scopes which occurs within functions. We use "qualified" lookup into
+  // function declarations when handling friend declarations inside nested
+  // classes, and consequently accept the following invalid code:
+  //
+  //   void f() { void g(); { int g; struct S { friend void g(); }; } }
+  if (isFunctionOrMethod() && !isa<FunctionDecl>(D))
+    return;
+
+  // Skip declarations which should be invisible to name lookup.
+  if (shouldBeHidden(D))
+    return;
+
+  // If we already have a lookup data structure, perform the insertion into
+  // it. If we might have externally-stored decls with this name, look them
+  // up and perform the insertion. If this decl was declared outside its
+  // semantic context, buildLookup won't add it, so add it now.
+  //
+  // FIXME: As a performance hack, don't add such decls into the translation
+  // unit unless we're in C++, since qualified lookup into the TU is never
+  // performed.
+  if (LookupPtr.getPointer() || hasExternalVisibleStorage() ||
+      ((!Recoverable || D->getDeclContext() != D->getLexicalDeclContext()) &&
+       (getParentASTContext().getLangOpts().CPlusPlus ||
+        !isTranslationUnit()))) {
+    // If we have lazily omitted any decls, they might have the same name as
+    // the decl which we are adding, so build a full lookup table before adding
+    // this decl.
+    buildLookup();
+    makeDeclVisibleInContextImpl(D, Internal);
+  } else {
+    LookupPtr.setInt(true);
+  }
+
+  // If we are a transparent context or inline namespace, insert into our
+  // parent context, too. This operation is recursive.
+  if (isTransparentContext() || isInlineNamespace())
+    getParent()->getPrimaryContext()->
+        makeDeclVisibleInContextWithFlags(D, Internal, Recoverable);
+
+  Decl *DCAsDecl = cast<Decl>(this);
+  // Notify that a decl was made visible unless we are a Tag being defined.
+  if (!(isa<TagDecl>(DCAsDecl) && cast<TagDecl>(DCAsDecl)->isBeingDefined()))
+    if (ASTMutationListener *L = DCAsDecl->getASTMutationListener())
+      L->AddedVisibleDecl(this, D);
+}
+
+void DeclContext::makeDeclVisibleInContextImpl(NamedDecl *D, bool Internal) {
+  // Find or create the stored declaration map.
+  StoredDeclsMap *Map = LookupPtr.getPointer();
+  if (!Map) {
+    ASTContext *C = &getParentASTContext();
+    Map = CreateStoredDeclsMap(*C);
+  }
+
+  // If there is an external AST source, load any declarations it knows about
+  // with this declaration's name.
+  // If the lookup table contains an entry about this name it means that we
+  // have already checked the external source.
+  if (!Internal)
+    if (ExternalASTSource *Source = getParentASTContext().getExternalSource())
+      if (hasExternalVisibleStorage() &&
+          Map->find(D->getDeclName()) == Map->end())
+        Source->FindExternalVisibleDeclsByName(this, D->getDeclName());
+
+  // Insert this declaration into the map.
+  StoredDeclsList &DeclNameEntries = (*Map)[D->getDeclName()];
+  if (DeclNameEntries.isNull()) {
+    DeclNameEntries.setOnlyValue(D);
+    return;
+  }
+
+  if (DeclNameEntries.HandleRedeclaration(D)) {
+    // This declaration has replaced an existing one for which
+    // declarationReplaces returns true.
+    return;
+  }
+
+  // Put this declaration into the appropriate slot.
+  DeclNameEntries.AddSubsequentDecl(D);
+}
+
+/// Returns iterator range [First, Last) of UsingDirectiveDecls stored within
+/// this context.
+DeclContext::udir_iterator_range
+DeclContext::getUsingDirectives() const {
+  // FIXME: Use something more efficient than normal lookup for using
+  // directives. In C++, using directives are looked up more than anything else.
+  lookup_const_result Result = lookup(UsingDirectiveDecl::getName());
+  return udir_iterator_range(reinterpret_cast<udir_iterator>(Result.first),
+                             reinterpret_cast<udir_iterator>(Result.second));
+}
+
+//===----------------------------------------------------------------------===//
+// Creation and Destruction of StoredDeclsMaps.                               //
+//===----------------------------------------------------------------------===//
+
+StoredDeclsMap *DeclContext::CreateStoredDeclsMap(ASTContext &C) const {
+  assert(!LookupPtr.getPointer() && "context already has a decls map");
+  assert(getPrimaryContext() == this &&
+         "creating decls map on non-primary context");
+
+  StoredDeclsMap *M;
+  bool Dependent = isDependentContext();
+  if (Dependent)
+    M = new DependentStoredDeclsMap();
+  else
+    M = new StoredDeclsMap();
+  M->Previous = C.LastSDM;
+  C.LastSDM = llvm::PointerIntPair<StoredDeclsMap*,1>(M, Dependent);
+  LookupPtr.setPointer(M);
+  return M;
+}
+
+void ASTContext::ReleaseDeclContextMaps() {
+  // It's okay to delete DependentStoredDeclsMaps via a StoredDeclsMap
+  // pointer because the subclass doesn't add anything that needs to
+  // be deleted.
+  StoredDeclsMap::DestroyAll(LastSDM.getPointer(), LastSDM.getInt());
+}
+
+void StoredDeclsMap::DestroyAll(StoredDeclsMap *Map, bool Dependent) {
+  while (Map) {
+    // Advance the iteration before we invalidate memory.
+    llvm::PointerIntPair<StoredDeclsMap*,1> Next = Map->Previous;
+
+    if (Dependent)
+      delete static_cast<DependentStoredDeclsMap*>(Map);
+    else
+      delete Map;
+
+    Map = Next.getPointer();
+    Dependent = Next.getInt();
+  }
+}
+
+DependentDiagnostic *DependentDiagnostic::Create(ASTContext &C,
+                                                 DeclContext *Parent,
+                                           const PartialDiagnostic &PDiag) {
+  assert(Parent->isDependentContext()
+         && "cannot iterate dependent diagnostics of non-dependent context");
+  Parent = Parent->getPrimaryContext();
+  if (!Parent->LookupPtr.getPointer())
+    Parent->CreateStoredDeclsMap(C);
+
+  DependentStoredDeclsMap *Map
+    = static_cast<DependentStoredDeclsMap*>(Parent->LookupPtr.getPointer());
+
+  // Allocate the copy of the PartialDiagnostic via the ASTContext's
+  // BumpPtrAllocator, rather than the ASTContext itself.
+  PartialDiagnostic::Storage *DiagStorage = 0;
+  if (PDiag.hasStorage())
+    DiagStorage = new (C) PartialDiagnostic::Storage;
+  
+  DependentDiagnostic *DD = new (C) DependentDiagnostic(PDiag, DiagStorage);
+
+  // TODO: Maybe we shouldn't reverse the order during insertion.
+  DD->NextDiagnostic = Map->FirstDiagnostic;
+  Map->FirstDiagnostic = DD;
+
+  return DD;
+}