//===--- ASTImporter.cpp - Importing ASTs from other Contexts ---*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file defines the ASTImporter class which imports AST nodes from one
//  context into another context.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/ASTImporter.h"
#include "clang/AST/Attr.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTDiagnostic.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclVisitor.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/AST/TypeVisitor.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Sema/Sema.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/FileSystem.h"
#include <deque>

namespace clang {
  class ASTNodeImporter : public TypeVisitor<ASTNodeImporter, QualType>,
                          public DeclVisitor<ASTNodeImporter, Decl *>,
                          public StmtVisitor<ASTNodeImporter, Stmt *> {
    ASTImporter &Importer;
    
  public:
    explicit ASTNodeImporter(ASTImporter &Importer) : Importer(Importer) { }
    
    using TypeVisitor<ASTNodeImporter, QualType>::Visit;
    using DeclVisitor<ASTNodeImporter, Decl *>::Visit;
    using StmtVisitor<ASTNodeImporter, Stmt *>::Visit;

    // Importing types
    QualType VisitType(const Type *T);
    QualType VisitAttributedType(const AttributedType *T);
    QualType VisitBuiltinType(const BuiltinType *T);
    QualType VisitDecayedType(const DecayedType *T);
    QualType VisitComplexType(const ComplexType *T);
    QualType VisitPointerType(const PointerType *T);
    QualType VisitBlockPointerType(const BlockPointerType *T);
    QualType VisitLValueReferenceType(const LValueReferenceType *T);
    QualType VisitRValueReferenceType(const RValueReferenceType *T);
    QualType VisitMemberPointerType(const MemberPointerType *T);
    QualType VisitConstantArrayType(const ConstantArrayType *T);
    QualType VisitIncompleteArrayType(const IncompleteArrayType *T);
    QualType VisitVariableArrayType(const VariableArrayType *T);
    QualType VisitDependentSizedArrayType(const DependentSizedArrayType *T);
    // FIXME: DependentSizedExtVectorType
    QualType VisitVectorType(const VectorType *T);
    QualType VisitExtVectorType(const ExtVectorType *T);
    QualType VisitFunctionNoProtoType(const FunctionNoProtoType *T);
    QualType VisitFunctionProtoType(const FunctionProtoType *T);
    QualType VisitUnresolvedUsingType(const UnresolvedUsingType *T);
    QualType VisitParenType(const ParenType *T);
    QualType VisitTypedefType(const TypedefType *T);
    QualType VisitTypeOfExprType(const TypeOfExprType *T);
    // FIXME: DependentTypeOfExprType
    QualType VisitTypeOfType(const TypeOfType *T);
    QualType VisitDecltypeType(const DecltypeType *T);
    QualType VisitUnaryTransformType(const UnaryTransformType *T);
    QualType VisitAutoType(const AutoType *T);
    QualType VisitInjectedClassNameType(const InjectedClassNameType *T);
    // FIXME: DependentDecltypeType
    QualType VisitRecordType(const RecordType *T);
    QualType VisitEnumType(const EnumType *T);
    QualType VisitTemplateTypeParmType(const TemplateTypeParmType *T);
    QualType VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T);
    QualType VisitTemplateSpecializationType(const TemplateSpecializationType *T);
    QualType VisitElaboratedType(const ElaboratedType *T);
    QualType VisitDependentNameType(const DependentNameType *T);
    QualType VisitPackExpansionType(const PackExpansionType *T);
    QualType VisitDependentTemplateSpecializationType(
        const DependentTemplateSpecializationType *T);
    QualType VisitObjCInterfaceType(const ObjCInterfaceType *T);
    QualType VisitObjCObjectType(const ObjCObjectType *T);
    QualType VisitObjCObjectPointerType(const ObjCObjectPointerType *T);
                            
    // Importing declarations                            
    bool ImportDeclParts(NamedDecl *D, DeclContext *&DC, 
                         DeclContext *&LexicalDC, DeclarationName &Name, 
                         SourceLocation &Loc);
    void ImportDefinitionIfNeeded(Decl *FromD, Decl *ToD = 0);
    void ImportDeclarationNameLoc(const DeclarationNameInfo &From,
                                  DeclarationNameInfo& To);
    void ImportDeclContext(DeclContext *FromDC, bool ForceImport = false);

    bool ImportCastPath(CastExpr *E, CXXCastPath &Path);

    bool ImportVarDeclInfo(VarDecl *From, VarDecl *To);

    typedef DesignatedInitExpr::Designator Designator;
    Designator ImportDesignator(const Designator &D);

    /// \brief What we should import from the definition.
    enum ImportDefinitionKind { 
      /// \brief Import the default subset of the definition, which might be
      /// nothing (if minimal import is set) or might be everything (if minimal
      /// import is not set).
      IDK_Default,
      /// \brief Import everything.
      IDK_Everything,
      /// \brief Import only the bare bones needed to establish a valid
      /// DeclContext.
      IDK_Basic
    };

    bool shouldForceImportDeclContext(ImportDefinitionKind IDK) {
      return IDK == IDK_Everything ||
             (IDK == IDK_Default && !Importer.isMinimalImport());
    }


    bool ImportDefinition(FunctionDecl *From, FunctionDecl *To);

    bool ImportDefinition(RecordDecl *From, RecordDecl *To, 
                          ImportDefinitionKind Kind = IDK_Default);
    bool ImportDefinition(VarDecl *From, VarDecl *To,
                          ImportDefinitionKind Kind = IDK_Default);
    bool ImportDefinition(EnumDecl *From, EnumDecl *To,
                          ImportDefinitionKind Kind = IDK_Default);
    bool ImportDefinition(ObjCInterfaceDecl *From, ObjCInterfaceDecl *To,
                          ImportDefinitionKind Kind = IDK_Default);
    bool ImportDefinition(ObjCProtocolDecl *From, ObjCProtocolDecl *To,
                          ImportDefinitionKind Kind = IDK_Default);

    void ImportAttributes(Decl *From, Decl *To);

    TemplateParameterList *ImportTemplateParameterList(
                                                 TemplateParameterList *Params);
    TemplateArgument ImportTemplateArgument(const TemplateArgument &From);
    TemplateArgumentLoc ImportTemplateArgumentLoc(
        const TemplateArgumentLoc &TALoc);
    bool ImportTemplateArguments(const TemplateArgument *FromArgs,
                                 unsigned NumFromArgs,
                               SmallVectorImpl<TemplateArgument> &ToArgs);
    bool IsStructuralMatch(RecordDecl *FromRecord, RecordDecl *ToRecord,
                           bool Complain = true);
    bool IsStructuralMatch(VarDecl *FromVar, VarDecl *ToVar,
                           bool Complain = true);
    bool IsStructuralMatch(EnumDecl *FromEnum, EnumDecl *ToRecord);
    bool IsStructuralMatch(EnumConstantDecl *FromEC, EnumConstantDecl *ToEC);
    bool IsStructuralMatch(ClassTemplateDecl *From, ClassTemplateDecl *To,
                           bool Complain = true);
    bool IsStructuralMatch(FunctionTemplateDecl *From,
                           FunctionTemplateDecl *To);
    bool IsStructuralMatch(VarTemplateDecl *From, VarTemplateDecl *To);
    Decl *VisitDecl(Decl *D);
    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
    Decl *VisitEmptyDecl(EmptyDecl *D);
    Decl *VisitNamespaceDecl(NamespaceDecl *D);
    Decl *VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
    Decl *VisitLinkageSpecDecl(LinkageSpecDecl *D);
    Decl *VisitUsingDecl(UsingDecl *D);
    Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
    Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
    Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
    Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
    Decl *VisitAccessSpecDecl(AccessSpecDecl *D);
    Decl *VisitTypedefNameDecl(TypedefNameDecl *D, bool IsAlias);
    Decl *VisitTypedefDecl(TypedefDecl *D);
    Decl *VisitTypeAliasDecl(TypeAliasDecl *D);
    Decl *VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
    Decl *VisitLabelDecl(LabelDecl *D);
    Decl *VisitEnumDecl(EnumDecl *D);
    Decl *VisitRecordDecl(RecordDecl *D);
    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
    Decl *VisitFunctionDecl(FunctionDecl *D);
    Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
    Decl *VisitCXXMethodDecl(CXXMethodDecl *D);
    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
    Decl *VisitFieldDecl(FieldDecl *D);
    Decl *VisitIndirectFieldDecl(IndirectFieldDecl *D);
    Decl *VisitFriendDecl(FriendDecl *D);
    Decl *VisitObjCIvarDecl(ObjCIvarDecl *D);
    Decl *VisitVarDecl(VarDecl *D);
    Decl *VisitImplicitParamDecl(ImplicitParamDecl *D);
    Decl *VisitParmVarDecl(ParmVarDecl *D);
    Decl *VisitObjCMethodDecl(ObjCMethodDecl *D);
    Decl *VisitObjCCategoryDecl(ObjCCategoryDecl *D);
    Decl *VisitObjCProtocolDecl(ObjCProtocolDecl *D);
    Decl *VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
    Decl *VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D);
    Decl *VisitObjCImplementationDecl(ObjCImplementationDecl *D);
    Decl *VisitObjCPropertyDecl(ObjCPropertyDecl *D);
    Decl *VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
    Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
    Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
    Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
    Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
    Decl *VisitClassTemplateSpecializationDecl(
                                            ClassTemplateSpecializationDecl *D);
    Decl *VisitVarTemplateDecl(VarTemplateDecl *D);
    Decl *VisitVarTemplateSpecializationDecl(VarTemplateSpecializationDecl *D);

    // Importing statements
    Stmt *VisitStmt(Stmt *S);
    Stmt *VisitGCCAsmStmt(GCCAsmStmt *S);
    Stmt *VisitGotoStmt(GotoStmt *S);
    Stmt *VisitIndirectGotoStmt(IndirectGotoStmt *S);
    Stmt *VisitLabelStmt(LabelStmt *S);
    Stmt *VisitAttributedStmt(AttributedStmt *S);
    Stmt *VisitCompoundStmt(CompoundStmt *S);
    Stmt *VisitDeclStmt(DeclStmt *S);
    Stmt *VisitIfStmt(IfStmt *S);
    Stmt *VisitForStmt(ForStmt *S);
    Stmt *VisitDoStmt(DoStmt *S);
    Stmt *VisitWhileStmt(WhileStmt *S);
    Stmt *VisitSwitchStmt(SwitchStmt *S);
    Stmt *VisitCaseStmt(CaseStmt *S);
    Stmt *VisitDefaultStmt(DefaultStmt *S);
    Stmt *VisitBreakStmt(BreakStmt *S);
    Stmt *VisitContinueStmt(ContinueStmt *S);
    Stmt *VisitNullStmt(NullStmt *S);
    Stmt *VisitReturnStmt(ReturnStmt *S);
    Stmt *VisitCXXTryStmt(CXXTryStmt *S);
    Stmt *VisitCXXCatchStmt(CXXCatchStmt *S);

    // Importing expressions
    Expr *VisitExpr(Expr *E);
    Expr *VisitVAArgExpr(VAArgExpr *E);
    Expr *VisitGNUNullExpr(GNUNullExpr *E);
    Expr *VisitPredefinedExpr(PredefinedExpr *E);
    Expr *VisitDeclRefExpr(DeclRefExpr *E);
    Expr *VisitDependentScopeDeclRefExpr(DependentScopeDeclRefExpr *E);
    Expr *VisitInitListExpr(InitListExpr *ILE);
    Expr *VisitDesignatedInitExpr(DesignatedInitExpr *E);
    Expr *VisitCXXNullPtrLiteralExpr(CXXNullPtrLiteralExpr *E);
    Expr *VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E);
    Expr *VisitIntegerLiteral(IntegerLiteral *E);
    Expr *VisitFloatingLiteral(FloatingLiteral *E);
    Expr *VisitCharacterLiteral(CharacterLiteral *E);
    Expr *VisitStringLiteral(StringLiteral *E);
    Expr *VisitCompoundLiteralExpr(CompoundLiteralExpr *E);
    Expr *VisitAtomicExpr(AtomicExpr *E);
    Expr *VisitAddrLabelExpr(AddrLabelExpr *E);
    Expr *VisitParenExpr(ParenExpr *E);
    Expr *VisitParenListExpr(ParenListExpr *E);
    Expr *VisitStmtExpr(StmtExpr *E);
    Expr *VisitUnaryOperator(UnaryOperator *E);
    Expr *VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E);
    Expr *VisitBinaryOperator(BinaryOperator *E);
    Expr *VisitConditionalOperator(ConditionalOperator *E);
    Expr *VisitBinaryConditionalOperator(BinaryConditionalOperator *E);
    Expr *VisitBinaryTypeTraitExpr(BinaryTypeTraitExpr *E);
    Expr *VisitExpressionTraitExpr(ExpressionTraitExpr *E);
    Expr *VisitOpaqueValueExpr(OpaqueValueExpr *E);
    Expr *VisitArraySubscriptExpr(ArraySubscriptExpr *E);
    Expr *VisitCompoundAssignOperator(CompoundAssignOperator *E);
    Expr *VisitImplicitCastExpr(ImplicitCastExpr *E);
    Expr *VisitExplicitCastExpr(ExplicitCastExpr *E);
    Expr *VisitImplicitValueInitExpr(ImplicitValueInitExpr *E);
    Expr *VisitOffsetOfExpr(OffsetOfExpr *E);
    Expr *VisitUnaryTypeTraitExpr(UnaryTypeTraitExpr *E);
    Expr *VisitMemberExpr(MemberExpr *E);
    Expr *VisitCXXThisExpr(CXXThisExpr *E);
    Expr *VisitCXXThrowExpr(CXXThrowExpr *E);
    Expr *VisitCXXNoexceptExpr(CXXNoexceptExpr *E);
    Expr *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *E);
    Expr *VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E);
    Expr *VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
    Expr *VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *CE);
    Expr *VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E);
    Expr *VisitOverloadExpr(OverloadExpr *E);
    Expr *VisitCXXDependentScopeMemberExpr(CXXDependentScopeMemberExpr *E);
    Expr *VisitCXXUnresolvedConstructExpr(CXXUnresolvedConstructExpr *CE);
    Expr *VisitCXXPseudoDestructorExpr(CXXPseudoDestructorExpr *E);
    Expr *VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E);
    Expr *VisitSizeOfPackExpr(SizeOfPackExpr *E);
    Expr *VisitPackExpansionExpr(PackExpansionExpr *E);
    Expr *VisitCXXNewExpr(CXXNewExpr *CE);
    Expr *VisitCXXDeleteExpr(CXXDeleteExpr *E);
    Expr *VisitCXXConstructExpr(CXXConstructExpr *CE);
    Expr *VisitExprWithCleanups(ExprWithCleanups *E);
    Expr *VisitCallExpr(CallExpr *CE);
  };
}
using namespace clang;

//----------------------------------------------------------------------------
// Structural Equivalence
//----------------------------------------------------------------------------

namespace {
  struct StructuralEquivalenceContext {
    /// \brief AST contexts for which we are checking structural equivalence.
    ASTContext &C1, &C2;
    
    /// \brief The set of "tentative" equivalences between two canonical 
    /// declarations, mapping from a declaration in the first context to the
    /// declaration in the second context that we believe to be equivalent.
    llvm::DenseMap<Decl *, Decl *> TentativeEquivalences;
    
    /// \brief Queue of declarations in the first context whose equivalence
    /// with a declaration in the second context still needs to be verified.
    std::deque<Decl *> DeclsToCheck;
    
    /// \brief Declaration (from, to) pairs that are known not to be equivalent
    /// (which we have already complained about).
    llvm::DenseSet<std::pair<Decl *, Decl *> > &NonEquivalentDecls;
    
    /// \brief Whether we're being strict about the spelling of types when 
    /// unifying two types.
    bool StrictTypeSpelling;

    /// \brief Whether to complain about failures.
    bool Complain;

    /// \brief \c true if the last diagnostic came from C2.
    bool LastDiagFromC2;

    StructuralEquivalenceContext(ASTContext &C1, ASTContext &C2,
               llvm::DenseSet<std::pair<Decl *, Decl *> > &NonEquivalentDecls,
                                 bool StrictTypeSpelling = false,
                                 bool Complain = true)
      : C1(C1), C2(C2), NonEquivalentDecls(NonEquivalentDecls),
        StrictTypeSpelling(StrictTypeSpelling), Complain(Complain),
        LastDiagFromC2(false) {}

    /// \brief Determine whether the two declarations are structurally
    /// equivalent.
    bool IsStructurallyEquivalent(Decl *D1, Decl *D2);
    
    /// \brief Determine whether the two types are structurally equivalent.
    bool IsStructurallyEquivalent(QualType T1, QualType T2,
                                  bool CheckQualifiers = true);

  private:
    /// \brief Finish checking all of the structural equivalences.
    ///
    /// \returns true if an error occurred, false otherwise.
    bool Finish();
    
  public:
    DiagnosticBuilder Diag1(SourceLocation Loc, unsigned DiagID) {
      assert(Complain && "Not allowed to complain");
      if (LastDiagFromC2)
        C1.getDiagnostics().notePriorDiagnosticFrom(C2.getDiagnostics());
      LastDiagFromC2 = false;
      return C1.getDiagnostics().Report(Loc, DiagID);
    }

    DiagnosticBuilder Diag2(SourceLocation Loc, unsigned DiagID) {
      assert(Complain && "Not allowed to complain");
      if (!LastDiagFromC2)
        C2.getDiagnostics().notePriorDiagnosticFrom(C1.getDiagnostics());
      LastDiagFromC2 = true;
      return C2.getDiagnostics().Report(Loc, DiagID);
    }
  };
}

static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     QualType T1, QualType T2,
                                     bool CheckQualifiers = true);
static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     Decl *D1, Decl *D2);
static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     const TemplateArgument &Arg1,
                                     const TemplateArgument &Arg2);

/// \brief Determine structural equivalence of two expressions.
static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     Expr *E1, Expr *E2) {
  if (!E1 || !E2)
    return E1 == E2;
  
  // FIXME: Actually perform a structural comparison!
  return true;
}

/// \brief Determine whether two identifiers are equivalent.
static bool IsStructurallyEquivalent(const IdentifierInfo *Name1,
                                     const IdentifierInfo *Name2) {
  if (!Name1 || !Name2)
    return Name1 == Name2;
  
  return Name1->getName() == Name2->getName();
}

/// \brief Determine whether two nested-name-specifiers are equivalent.
static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     NestedNameSpecifier *NNS1,
                                     NestedNameSpecifier *NNS2) {
  if (NNS1->getKind() != NNS2->getKind())
    return false;

  NestedNameSpecifier *Prefix1 = NNS1->getPrefix(),
      *Prefix2 = NNS2->getPrefix();
  if ((bool)Prefix1 ^ (bool)Prefix2)
    return false;
  if (Prefix1)
    if (!IsStructurallyEquivalent(Context, Prefix1, Prefix2))
      return false;

  switch (NNS1->getKind()) {
  case NestedNameSpecifier::Identifier:
    return IsStructurallyEquivalent(NNS1->getAsIdentifier(),
                                    NNS2->getAsIdentifier());
  case NestedNameSpecifier::Namespace:
    return IsStructurallyEquivalent(Context, NNS1->getAsNamespace(),
                                    NNS2->getAsNamespace());
  case NestedNameSpecifier::NamespaceAlias:
    return IsStructurallyEquivalent(Context, NNS1->getAsNamespaceAlias(),
                                    NNS2->getAsNamespaceAlias());
  case NestedNameSpecifier::TypeSpec:
  case NestedNameSpecifier::TypeSpecWithTemplate:
    return IsStructurallyEquivalent(Context, QualType(NNS1->getAsType(), 0),
                                    QualType(NNS2->getAsType(), 0));
  case NestedNameSpecifier::Global:
    return true;
  }
  return true;
}

static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     const TemplateName &N1,
                                     const TemplateName &N2) {
  if (N1.getKind() != N2.getKind())
    return false;
  switch (N1.getKind()) {
  case TemplateName::Template:
    return IsStructurallyEquivalent(Context, N1.getAsTemplateDecl(),
                                    N2.getAsTemplateDecl());

  case TemplateName::OverloadedTemplate: {
    OverloadedTemplateStorage *OS1 = N1.getAsOverloadedTemplate(),
        *OS2 = N2.getAsOverloadedTemplate();
    OverloadedTemplateStorage::iterator I1 = OS1->begin(), I2 = OS2->begin(),
        E1 = OS1->end(), E2 = OS2->end();
    for (; I1 != E1 && I2 != E2; ++I1, ++I2)
      if (!IsStructurallyEquivalent(Context, *I1, *I2))
        return false;
    return I1 == E1 && I2 == E2;
  }

  case TemplateName::QualifiedTemplate: {
    QualifiedTemplateName *QN1 = N1.getAsQualifiedTemplateName(),
        *QN2 = N2.getAsQualifiedTemplateName();
    return IsStructurallyEquivalent(Context, QN1->getDecl(), QN2->getDecl()) &&
        IsStructurallyEquivalent(Context, QN1->getQualifier(),
                                 QN2->getQualifier());
  }

  case TemplateName::DependentTemplate: {
      DependentTemplateName *DN1 = N1.getAsDependentTemplateName(),
          *DN2 = N2.getAsDependentTemplateName();
      if (!IsStructurallyEquivalent(Context, DN1->getQualifier(),
                                    DN2->getQualifier()))
        return false;
      if (DN1->isIdentifier())
        return IsStructurallyEquivalent(DN1->getIdentifier(),
                                        DN2->getIdentifier());
      return DN1->getOperator() == DN2->getOperator();
  }

  case TemplateName::SubstTemplateTemplateParm: {
    SubstTemplateTemplateParmStorage *TS1 = N1.getAsSubstTemplateTemplateParm(),
        *TS2 = N2.getAsSubstTemplateTemplateParm();
    return IsStructurallyEquivalent(Context, TS1->getParameter(),
                                    TS2->getParameter()) &&
        IsStructurallyEquivalent(Context, TS1->getReplacement(),
                                 TS2->getReplacement());
    }
  case TemplateName::SubstTemplateTemplateParmPack: {
    SubstTemplateTemplateParmPackStorage
        *P1 = N1.getAsSubstTemplateTemplateParmPack(),
        *P2 = N2.getAsSubstTemplateTemplateParmPack();
    return IsStructurallyEquivalent(Context, P1->getArgumentPack(),
                                    P2->getArgumentPack()) &&
        IsStructurallyEquivalent(Context, P1->getParameterPack(),
                                 P2->getParameterPack());
  }
  }
  return true;
}

/// \brief Determine whether two template arguments are equivalent.
static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     const TemplateArgument &Arg1,
                                     const TemplateArgument &Arg2) {
  if (Arg1.getKind() != Arg2.getKind())
    return false;

  switch (Arg1.getKind()) {
  case TemplateArgument::Null:
    return true;
      
  case TemplateArgument::Type:
    return Context.IsStructurallyEquivalent(Arg1.getAsType(), Arg2.getAsType());

  case TemplateArgument::Integral:
    if (!Context.IsStructurallyEquivalent(Arg1.getIntegralType(), 
                                          Arg2.getIntegralType()))
      return false;
    
    return llvm::APSInt::isSameValue(Arg1.getAsIntegral(), Arg2.getAsIntegral());
      
  case TemplateArgument::Declaration:
    return Context.IsStructurallyEquivalent(Arg1.getAsDecl(), Arg2.getAsDecl());

  case TemplateArgument::NullPtr:
    return true; // FIXME: Is this correct?

  case TemplateArgument::Template:
    return IsStructurallyEquivalent(Context, 
                                    Arg1.getAsTemplate(), 
                                    Arg2.getAsTemplate());

  case TemplateArgument::TemplateExpansion:
    return IsStructurallyEquivalent(Context, 
                                    Arg1.getAsTemplateOrTemplatePattern(), 
                                    Arg2.getAsTemplateOrTemplatePattern());

  case TemplateArgument::Expression:
    return IsStructurallyEquivalent(Context, 
                                    Arg1.getAsExpr(), Arg2.getAsExpr());
      
  case TemplateArgument::Pack:
    if (Arg1.pack_size() != Arg2.pack_size())
      return false;
      
    for (unsigned I = 0, N = Arg1.pack_size(); I != N; ++I)
      if (!IsStructurallyEquivalent(Context, 
                                    Arg1.pack_begin()[I],
                                    Arg2.pack_begin()[I]))
        return false;
      
    return true;
  }
  
  llvm_unreachable("Invalid template argument kind");
}

/// \brief Determine structural equivalence for the common part of array 
/// types.
static bool IsArrayStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                          const ArrayType *Array1, 
                                          const ArrayType *Array2) {
  if (!IsStructurallyEquivalent(Context, 
                                Array1->getElementType(), 
                                Array2->getElementType()))
    return false;
  if (Array1->getSizeModifier() != Array2->getSizeModifier())
    return false;
  if (Array1->getIndexTypeQualifiers() != Array2->getIndexTypeQualifiers())
    return false;
  
  return true;
}

/// \brief Determine structural equivalence of two types.
static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     QualType T1, QualType T2,
                                     bool CheckQualifiers) {
  if (T1.isNull() || T2.isNull())
    return T1.isNull() && T2.isNull();
  
  if (!Context.StrictTypeSpelling) {
    // We aren't being strict about token-to-token equivalence of types,
    // so map down to the canonical type.
    T1 = Context.C1.getCanonicalType(T1);
    T2 = Context.C2.getCanonicalType(T2);
  }
  
  if (CheckQualifiers && T1.getQualifiers() != T2.getQualifiers())
    return false;
  
  Type::TypeClass TC = T1->getTypeClass();
  
  if (T1->getTypeClass() != T2->getTypeClass()) {
    // Compare function types with prototypes vs. without prototypes as if
    // both did not have prototypes.
    if (T1->getTypeClass() == Type::FunctionProto &&
        T2->getTypeClass() == Type::FunctionNoProto)
      TC = Type::FunctionNoProto;
    else if (T1->getTypeClass() == Type::FunctionNoProto &&
             T2->getTypeClass() == Type::FunctionProto)
      TC = Type::FunctionNoProto;
    else
      return false;
  }
  
  switch (TC) {
  case Type::Builtin:
    // FIXME: Deal with Char_S/Char_U. 
    if (cast<BuiltinType>(T1)->getKind() != cast<BuiltinType>(T2)->getKind())
      return false;
    break;
  
  case Type::Complex:
    if (!IsStructurallyEquivalent(Context,
                                  cast<ComplexType>(T1)->getElementType(),
                                  cast<ComplexType>(T2)->getElementType()))
      return false;
    break;
  
  case Type::Decayed:
    if (!IsStructurallyEquivalent(Context,
                                  cast<DecayedType>(T1)->getPointeeType(),
                                  cast<DecayedType>(T2)->getPointeeType()))
      return false;
    break;

  case Type::Pointer:
    if (!IsStructurallyEquivalent(Context,
                                  cast<PointerType>(T1)->getPointeeType(),
                                  cast<PointerType>(T2)->getPointeeType()))
      return false;
    break;

  case Type::BlockPointer:
    if (!IsStructurallyEquivalent(Context,
                                  cast<BlockPointerType>(T1)->getPointeeType(),
                                  cast<BlockPointerType>(T2)->getPointeeType()))
      return false;
    break;

  case Type::LValueReference:
  case Type::RValueReference: {
    const ReferenceType *Ref1 = cast<ReferenceType>(T1);
    const ReferenceType *Ref2 = cast<ReferenceType>(T2);
    if (Ref1->isSpelledAsLValue() != Ref2->isSpelledAsLValue())
      return false;
    if (Ref1->isInnerRef() != Ref2->isInnerRef())
      return false;
    if (!IsStructurallyEquivalent(Context,
                                  Ref1->getPointeeTypeAsWritten(),
                                  Ref2->getPointeeTypeAsWritten()))
      return false;
    break;
  }
      
  case Type::MemberPointer: {
    const MemberPointerType *MemPtr1 = cast<MemberPointerType>(T1);
    const MemberPointerType *MemPtr2 = cast<MemberPointerType>(T2);
    if (!IsStructurallyEquivalent(Context,
                                  MemPtr1->getPointeeType(),
                                  MemPtr2->getPointeeType()))
      return false;
    if (!IsStructurallyEquivalent(Context,
                                  QualType(MemPtr1->getClass(), 0),
                                  QualType(MemPtr2->getClass(), 0)))
      return false;
    break;
  }
      
  case Type::ConstantArray: {
    const ConstantArrayType *Array1 = cast<ConstantArrayType>(T1);
    const ConstantArrayType *Array2 = cast<ConstantArrayType>(T2);
    if (!llvm::APInt::isSameValue(Array1->getSize(), Array2->getSize()))
      return false;
    
    if (!IsArrayStructurallyEquivalent(Context, Array1, Array2))
      return false;
    break;
  }

  case Type::IncompleteArray:
    if (!IsArrayStructurallyEquivalent(Context, 
                                       cast<ArrayType>(T1), 
                                       cast<ArrayType>(T2)))
      return false;
    break;
      
  case Type::VariableArray: {
    const VariableArrayType *Array1 = cast<VariableArrayType>(T1);
    const VariableArrayType *Array2 = cast<VariableArrayType>(T2);
    if (!IsStructurallyEquivalent(Context, 
                                  Array1->getSizeExpr(), Array2->getSizeExpr()))
      return false;
    
    if (!IsArrayStructurallyEquivalent(Context, Array1, Array2))
      return false;
    
    break;
  }
  
  case Type::DependentSizedArray: {
    const DependentSizedArrayType *Array1 = cast<DependentSizedArrayType>(T1);
    const DependentSizedArrayType *Array2 = cast<DependentSizedArrayType>(T2);
    if (!IsStructurallyEquivalent(Context, 
                                  Array1->getSizeExpr(), Array2->getSizeExpr()))
      return false;
    
    if (!IsArrayStructurallyEquivalent(Context, Array1, Array2))
      return false;
    
    break;
  }
      
  case Type::DependentSizedExtVector: {
    const DependentSizedExtVectorType *Vec1
      = cast<DependentSizedExtVectorType>(T1);
    const DependentSizedExtVectorType *Vec2
      = cast<DependentSizedExtVectorType>(T2);
    if (!IsStructurallyEquivalent(Context, 
                                  Vec1->getSizeExpr(), Vec2->getSizeExpr()))
      return false;
    if (!IsStructurallyEquivalent(Context, 
                                  Vec1->getElementType(), 
                                  Vec2->getElementType()))
      return false;
    break;
  }
   
  case Type::Vector: 
  case Type::ExtVector: {
    const VectorType *Vec1 = cast<VectorType>(T1);
    const VectorType *Vec2 = cast<VectorType>(T2);
    if (!IsStructurallyEquivalent(Context, 
                                  Vec1->getElementType(),
                                  Vec2->getElementType()))
      return false;
    if (Vec1->getNumElements() != Vec2->getNumElements())
      return false;
    if (Vec1->getVectorKind() != Vec2->getVectorKind())
      return false;
    break;
  }

  case Type::FunctionProto: {
    const FunctionProtoType *Proto1 = cast<FunctionProtoType>(T1);
    const FunctionProtoType *Proto2 = cast<FunctionProtoType>(T2);
    if (Proto1->getNumArgs() != Proto2->getNumArgs())
      return false;
    for (unsigned I = 0, N = Proto1->getNumArgs(); I != N; ++I) {
      if (!IsStructurallyEquivalent(Context, 
                                    Proto1->getArgType(I),
                                    Proto2->getArgType(I)))
        return false;
    }
    if (Proto1->isVariadic() != Proto2->isVariadic())
      return false;
    if (Proto1->getExceptionSpecType() != Proto2->getExceptionSpecType())
      return false;
    if (Proto1->getExceptionSpecType() == EST_Dynamic) {
      if (Proto1->getNumExceptions() != Proto2->getNumExceptions())
        return false;
      for (unsigned I = 0, N = Proto1->getNumExceptions(); I != N; ++I) {
        if (!IsStructurallyEquivalent(Context,
                                      Proto1->getExceptionType(I),
                                      Proto2->getExceptionType(I)))
          return false;
      }
    } else if (Proto1->getExceptionSpecType() == EST_ComputedNoexcept) {
      if (!IsStructurallyEquivalent(Context,
                                    Proto1->getNoexceptExpr(),
                                    Proto2->getNoexceptExpr()))
        return false;
    }
    if (Proto1->getTypeQuals() != Proto2->getTypeQuals())
      return false;
    
    // Fall through to check the bits common with FunctionNoProtoType.
  }
      
  case Type::FunctionNoProto: {
    const FunctionType *Function1 = cast<FunctionType>(T1);
    const FunctionType *Function2 = cast<FunctionType>(T2);
    if (!IsStructurallyEquivalent(Context, 
                                  Function1->getResultType(),
                                  Function2->getResultType()))
      return false;
      if (Function1->getExtInfo() != Function2->getExtInfo())
        return false;
    break;
  }
   
  case Type::UnresolvedUsing:
    if (!IsStructurallyEquivalent(Context,
                                  cast<UnresolvedUsingType>(T1)->getDecl(),
                                  cast<UnresolvedUsingType>(T2)->getDecl()))
      return false;
      
    break;

  case Type::Attributed:
    if (!IsStructurallyEquivalent(Context,
                                  cast<AttributedType>(T1)->getModifiedType(),
                                  cast<AttributedType>(T2)->getModifiedType()))
      return false;
    if (!IsStructurallyEquivalent(Context,
                                cast<AttributedType>(T1)->getEquivalentType(),
                                cast<AttributedType>(T2)->getEquivalentType()))
      return false;
    break;
      
  case Type::Paren:
    if (!IsStructurallyEquivalent(Context,
                                  cast<ParenType>(T1)->getInnerType(),
                                  cast<ParenType>(T2)->getInnerType()))
      return false;
    break;

  case Type::Typedef:
    if (!IsStructurallyEquivalent(Context,
                                  cast<TypedefType>(T1)->getDecl(),
                                  cast<TypedefType>(T2)->getDecl()))
      return false;
    break;
      
  case Type::TypeOfExpr:
    if (!IsStructurallyEquivalent(Context,
                                cast<TypeOfExprType>(T1)->getUnderlyingExpr(),
                                cast<TypeOfExprType>(T2)->getUnderlyingExpr()))
      return false;
    break;
      
  case Type::TypeOf:
    if (!IsStructurallyEquivalent(Context,
                                  cast<TypeOfType>(T1)->getUnderlyingType(),
                                  cast<TypeOfType>(T2)->getUnderlyingType()))
      return false;
    break;

  case Type::UnaryTransform:
    if (!IsStructurallyEquivalent(Context,
                             cast<UnaryTransformType>(T1)->getUnderlyingType(),
                             cast<UnaryTransformType>(T1)->getUnderlyingType()))
      return false;
    break;

  case Type::Decltype:
    if (!IsStructurallyEquivalent(Context,
                                  cast<DecltypeType>(T1)->getUnderlyingExpr(),
                                  cast<DecltypeType>(T2)->getUnderlyingExpr()))
      return false;
    break;

  case Type::Auto:
    if (!IsStructurallyEquivalent(Context,
                                  cast<AutoType>(T1)->getDeducedType(),
                                  cast<AutoType>(T2)->getDeducedType()))
      return false;
    break;

  case Type::Record:
  case Type::Enum:
    if (!IsStructurallyEquivalent(Context,
                                  cast<TagType>(T1)->getDecl(),
                                  cast<TagType>(T2)->getDecl()))
      return false;
    break;

  case Type::TemplateTypeParm: {
    const TemplateTypeParmType *Parm1 = cast<TemplateTypeParmType>(T1);
    const TemplateTypeParmType *Parm2 = cast<TemplateTypeParmType>(T2);
    if (Parm1->getDepth() != Parm2->getDepth())
      return false;
    if (Parm1->getIndex() != Parm2->getIndex())
      return false;
    if (Parm1->isParameterPack() != Parm2->isParameterPack())
      return false;
    
    // Names of template type parameters are never significant.
    break;
  }
      
  case Type::SubstTemplateTypeParm: {
    const SubstTemplateTypeParmType *Subst1
      = cast<SubstTemplateTypeParmType>(T1);
    const SubstTemplateTypeParmType *Subst2
      = cast<SubstTemplateTypeParmType>(T2);
    if (!IsStructurallyEquivalent(Context,
                                  QualType(Subst1->getReplacedParameter(), 0),
                                  QualType(Subst2->getReplacedParameter(), 0)))
      return false;
    if (!IsStructurallyEquivalent(Context, 
                                  Subst1->getReplacementType(),
                                  Subst2->getReplacementType()))
      return false;
    break;
  }

  case Type::SubstTemplateTypeParmPack: {
    const SubstTemplateTypeParmPackType *Subst1
      = cast<SubstTemplateTypeParmPackType>(T1);
    const SubstTemplateTypeParmPackType *Subst2
      = cast<SubstTemplateTypeParmPackType>(T2);
    if (!IsStructurallyEquivalent(Context,
                                  QualType(Subst1->getReplacedParameter(), 0),
                                  QualType(Subst2->getReplacedParameter(), 0)))
      return false;
    if (!IsStructurallyEquivalent(Context, 
                                  Subst1->getArgumentPack(),
                                  Subst2->getArgumentPack()))
      return false;
    break;
  }
  case Type::TemplateSpecialization: {
    const TemplateSpecializationType *Spec1
      = cast<TemplateSpecializationType>(T1);
    const TemplateSpecializationType *Spec2
      = cast<TemplateSpecializationType>(T2);
    if (!IsStructurallyEquivalent(Context,
                                  Spec1->getTemplateName(),
                                  Spec2->getTemplateName()))
      return false;
    if (Spec1->getNumArgs() != Spec2->getNumArgs())
      return false;
    for (unsigned I = 0, N = Spec1->getNumArgs(); I != N; ++I) {
      if (!IsStructurallyEquivalent(Context, 
                                    Spec1->getArg(I), Spec2->getArg(I)))
        return false;
    }
    break;
  }
      
  case Type::Elaborated: {
    const ElaboratedType *Elab1 = cast<ElaboratedType>(T1);
    const ElaboratedType *Elab2 = cast<ElaboratedType>(T2);
    // CHECKME: what if a keyword is ETK_None or ETK_typename ?
    if (Elab1->getKeyword() != Elab2->getKeyword())
      return false;
    if (!IsStructurallyEquivalent(Context, 
                                  Elab1->getQualifier(), 
                                  Elab2->getQualifier()))
      return false;
    if (!IsStructurallyEquivalent(Context,
                                  Elab1->getNamedType(),
                                  Elab2->getNamedType()))
      return false;
    break;
  }

  case Type::InjectedClassName: {
    const InjectedClassNameType *Inj1 = cast<InjectedClassNameType>(T1);
    const InjectedClassNameType *Inj2 = cast<InjectedClassNameType>(T2);
    if (!IsStructurallyEquivalent(Context,
                                  Inj1->getInjectedSpecializationType(),
                                  Inj2->getInjectedSpecializationType()))
      return false;
    break;
  }

  case Type::DependentName: {
    const DependentNameType *Typename1 = cast<DependentNameType>(T1);
    const DependentNameType *Typename2 = cast<DependentNameType>(T2);
    if (!IsStructurallyEquivalent(Context, 
                                  Typename1->getQualifier(),
                                  Typename2->getQualifier()))
      return false;
    if (!IsStructurallyEquivalent(Typename1->getIdentifier(),
                                  Typename2->getIdentifier()))
      return false;
    
    break;
  }
  
  case Type::DependentTemplateSpecialization: {
    const DependentTemplateSpecializationType *Spec1 =
      cast<DependentTemplateSpecializationType>(T1);
    const DependentTemplateSpecializationType *Spec2 =
      cast<DependentTemplateSpecializationType>(T2);
    if (!IsStructurallyEquivalent(Context, 
                                  Spec1->getQualifier(),
                                  Spec2->getQualifier()))
      return false;
    if (!IsStructurallyEquivalent(Spec1->getIdentifier(),
                                  Spec2->getIdentifier()))
      return false;
    if (Spec1->getNumArgs() != Spec2->getNumArgs())
      return false;
    for (unsigned I = 0, N = Spec1->getNumArgs(); I != N; ++I) {
      if (!IsStructurallyEquivalent(Context,
                                    Spec1->getArg(I), Spec2->getArg(I)))
        return false;
    }
    break;
  }

  case Type::PackExpansion:
    if (!IsStructurallyEquivalent(Context,
                                  cast<PackExpansionType>(T1)->getPattern(),
                                  cast<PackExpansionType>(T2)->getPattern()))
      return false;
    break;

  case Type::ObjCInterface: {
    const ObjCInterfaceType *Iface1 = cast<ObjCInterfaceType>(T1);
    const ObjCInterfaceType *Iface2 = cast<ObjCInterfaceType>(T2);
    if (!IsStructurallyEquivalent(Context, 
                                  Iface1->getDecl(), Iface2->getDecl()))
      return false;
    break;
  }

  case Type::ObjCObject: {
    const ObjCObjectType *Obj1 = cast<ObjCObjectType>(T1);
    const ObjCObjectType *Obj2 = cast<ObjCObjectType>(T2);
    if (!IsStructurallyEquivalent(Context,
                                  Obj1->getBaseType(),
                                  Obj2->getBaseType()))
      return false;
    if (Obj1->getNumProtocols() != Obj2->getNumProtocols())
      return false;
    for (unsigned I = 0, N = Obj1->getNumProtocols(); I != N; ++I) {
      if (!IsStructurallyEquivalent(Context,
                                    Obj1->getProtocol(I),
                                    Obj2->getProtocol(I)))
        return false;
    }
    break;
  }

  case Type::ObjCObjectPointer: {
    const ObjCObjectPointerType *Ptr1 = cast<ObjCObjectPointerType>(T1);
    const ObjCObjectPointerType *Ptr2 = cast<ObjCObjectPointerType>(T2);
    if (!IsStructurallyEquivalent(Context, 
                                  Ptr1->getPointeeType(),
                                  Ptr2->getPointeeType()))
      return false;
    break;
  }

  case Type::Atomic: {
    if (!IsStructurallyEquivalent(Context,
                                  cast<AtomicType>(T1)->getValueType(),
                                  cast<AtomicType>(T2)->getValueType()))
      return false;
    break;
  }

  } // end switch

  return true;
}

/// \brief Compare two source locations from different source managers.
static bool SourceLocationEqual(SourceLocation SL1, SourceManager &SM1,
                                SourceLocation SL2, SourceManager &SM2) {
  if (!SL1.isFileID() || !SL2.isFileID())
    return false;
  PresumedLoc PLoc1 = SM1.getPresumedLoc(SL1), PLoc2 = SM2.getPresumedLoc(SL2);

  if (PLoc1.isInvalid() || PLoc2.isInvalid())
    return false;

  if (PLoc1.getLine() != PLoc2.getLine() ||
      PLoc1.getColumn() != PLoc2.getColumn())
    return false;

  return llvm::sys::fs::equivalent(PLoc1.getFilename(), PLoc2.getFilename());
}

static bool SourceRangeEqual(const SourceRange &SR1, SourceManager &SM1,
                             const SourceRange &SR2, SourceManager &SM2) {
  return SourceLocationEqual(SR1.getBegin(), SM1, SR2.getBegin(), SM2) &&
      SourceLocationEqual(SR1.getEnd(), SM1, SR2.getEnd(), SM2);
}

/// \brief Determine structural equivalence of two fields.
static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     FieldDecl *Field1, FieldDecl *Field2) {
  RecordDecl *Owner2 = cast<RecordDecl>(Field2->getDeclContext());

  // For anonymous structs/unions, match up the anonymous struct/union type
  // declarations directly, so that we don't go off searching for anonymous
  // types
  if (Field1->isAnonymousStructOrUnion() &&
      Field2->isAnonymousStructOrUnion()) {
    RecordDecl *D1 = Field1->getType()->castAs<RecordType>()->getDecl();
    RecordDecl *D2 = Field2->getType()->castAs<RecordType>()->getDecl();
    return IsStructurallyEquivalent(Context, D1, D2);
  }
    
  // Check for equivalent field names.
  IdentifierInfo *Name1 = Field1->getIdentifier();
  IdentifierInfo *Name2 = Field2->getIdentifier();
  if (!::IsStructurallyEquivalent(Name1, Name2))
    return false;

  if (!Field1->getLocStart().isInvalid())
    if (SourceLocationEqual(Field1->getLocStart(),
                            Field1->getASTContext().getSourceManager(),
                            Field2->getLocStart(),
                            Field2->getASTContext().getSourceManager()))
      return true;

  if (!IsStructurallyEquivalent(Context,
                                Field1->getType(), Field2->getType())) {
    if (Context.Complain) {
      Context.Diag2(Owner2->getLocation(), diag::warn_odr_tag_type_inconsistent)
        << Context.C2.getTypeDeclType(Owner2);
      Context.Diag2(Field2->getLocation(), diag::note_odr_field)
        << Field2->getDeclName() << Field2->getType();
      Context.Diag1(Field1->getLocation(), diag::note_odr_field)
        << Field1->getDeclName() << Field1->getType();
    }
    return false;
  }
  
  if (Field1->isBitField() != Field2->isBitField()) {
    if (Context.Complain) {
      Context.Diag2(Owner2->getLocation(), diag::warn_odr_tag_type_inconsistent)
        << Context.C2.getTypeDeclType(Owner2);
      if (Field1->isBitField()) {
        Context.Diag1(Field1->getLocation(), diag::note_odr_bit_field)
        << Field1->getDeclName() << Field1->getType()
        << Field1->getBitWidthValue(Context.C1);
        Context.Diag2(Field2->getLocation(), diag::note_odr_not_bit_field)
        << Field2->getDeclName();
      } else {
        Context.Diag2(Field2->getLocation(), diag::note_odr_bit_field)
        << Field2->getDeclName() << Field2->getType()
        << Field2->getBitWidthValue(Context.C2);
        Context.Diag1(Field1->getLocation(), diag::note_odr_not_bit_field)
        << Field1->getDeclName();
      }
    }
    return false;
  }
  
  if (Field1->isBitField()) {
    // Make sure that the bit-fields are the same length.
    unsigned Bits1 = Field1->getBitWidthValue(Context.C1);
    unsigned Bits2 = Field2->getBitWidthValue(Context.C2);
    
    if (Bits1 != Bits2) {
      if (Context.Complain) {
        Context.Diag2(Owner2->getLocation(), diag::warn_odr_tag_type_inconsistent)
          << Context.C2.getTypeDeclType(Owner2);
        Context.Diag2(Field2->getLocation(), diag::note_odr_bit_field)
          << Field2->getDeclName() << Field2->getType() << Bits2;
        Context.Diag1(Field1->getLocation(), diag::note_odr_bit_field)
          << Field1->getDeclName() << Field1->getType() << Bits1;
      }
      return false;
    }
  }

  return true;
}

/// \brief Find the index of the given anonymous struct/union within its
/// context.
///
/// \returns Returns the index of this anonymous struct/union in its context,
/// including the next assigned index (if none of them match). Returns an
/// empty option if the context is not a record, i.e.. if the anonymous
/// struct/union is at namespace or block scope.
static Optional<unsigned> findAnonymousStructOrUnionIndex(RecordDecl *Anon) {
  ASTContext &Context = Anon->getASTContext();
  QualType AnonTy = Context.getRecordType(Anon);

  RecordDecl *Owner = dyn_cast<RecordDecl>(Anon->getDeclContext());
  if (!Owner)
    return None;

  unsigned Index = 0;
  for (DeclContext::decl_iterator D = Owner->decls_begin(),
                               DEnd = Owner->decls_end();
       D != DEnd; ++D) {
    FieldDecl *F = dyn_cast<FieldDecl>(*D);
    if (!F || !F->isAnonymousStructOrUnion())
      continue;

    if (Context.hasSameType(F->getType(), AnonTy))
      break;

    ++Index;
  }

  return Index;
}

/// \brief Determine structural equivalence of two records.
static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     RecordDecl *D1, RecordDecl *D2) {
  if (D1->isUnion() != D2->isUnion()) {
    if (Context.Complain) {
      Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
        << Context.C2.getTypeDeclType(D2);
      Context.Diag1(D1->getLocation(), diag::note_odr_tag_kind_here)
        << D1->getDeclName() << (unsigned)D1->getTagKind();
    }
    return false;
  }

  if (D1->isAnonymousStructOrUnion() && D2->isAnonymousStructOrUnion()) {
    // If both anonymous structs/unions are in a record context, make sure
    // they occur in the same location in the context records.
    if (Optional<unsigned> Index1 = findAnonymousStructOrUnionIndex(D1)) {
      if (Optional<unsigned> Index2 = findAnonymousStructOrUnionIndex(D2)) {
        if (*Index1 != *Index2)
          return false;
      }
    }
  }

  // If both declarations are class template specializations, we know
  // the ODR applies, so check the template and template arguments.
  ClassTemplateSpecializationDecl *Spec1
    = dyn_cast<ClassTemplateSpecializationDecl>(D1);
  ClassTemplateSpecializationDecl *Spec2
    = dyn_cast<ClassTemplateSpecializationDecl>(D2);
  if (Spec1 && Spec2) {
    // Check that the specialized templates are the same.
    if (!IsStructurallyEquivalent(Context, Spec1->getSpecializedTemplate(),
                                  Spec2->getSpecializedTemplate()))
      return false;
    
    // Check that the template arguments are the same.
    if (Spec1->getTemplateArgs().size() != Spec2->getTemplateArgs().size())
      return false;
    
    for (unsigned I = 0, N = Spec1->getTemplateArgs().size(); I != N; ++I)
      if (!IsStructurallyEquivalent(Context, 
                                    Spec1->getTemplateArgs().get(I),
                                    Spec2->getTemplateArgs().get(I)))
        return false;
  }  
  // If one is a class template specialization and the other is not, these
  // structures are different.
  else if (Spec1 || Spec2)
    return false;

  // Compare the definitions of these two records. If either or both are
  // incomplete, we assume that they are equivalent.
  D1 = D1->getDefinition();
  D2 = D2->getDefinition();
  if (!D1 || !D2)
    return true;
  
  if (CXXRecordDecl *D1CXX = dyn_cast<CXXRecordDecl>(D1)) {
    if (CXXRecordDecl *D2CXX = dyn_cast<CXXRecordDecl>(D2)) {
      if (D1CXX->getNumBases() != D2CXX->getNumBases()) {
        if (Context.Complain) {
          Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
            << Context.C2.getTypeDeclType(D2);
          Context.Diag2(D2->getLocation(), diag::note_odr_number_of_bases)
            << D2CXX->getNumBases();
          Context.Diag1(D1->getLocation(), diag::note_odr_number_of_bases)
            << D1CXX->getNumBases();
        }
        return false;
      }
      
      // Check the base classes. 
      for (CXXRecordDecl::base_class_iterator Base1 = D1CXX->bases_begin(), 
                                           BaseEnd1 = D1CXX->bases_end(),
                                                Base2 = D2CXX->bases_begin();
           Base1 != BaseEnd1;
           ++Base1, ++Base2) {        
        if (!IsStructurallyEquivalent(Context, 
                                      Base1->getType(), Base2->getType())) {
          if (Context.Complain) {
            Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
              << Context.C2.getTypeDeclType(D2);
            Context.Diag2(Base2->getLocStart(), diag::note_odr_base)
              << Base2->getType()
              << Base2->getSourceRange();
            Context.Diag1(Base1->getLocStart(), diag::note_odr_base)
              << Base1->getType()
              << Base1->getSourceRange();
          }
          return false;
        }
        
        // Check virtual vs. non-virtual inheritance mismatch.
        if (Base1->isVirtual() != Base2->isVirtual()) {
          if (Context.Complain) {
            Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
              << Context.C2.getTypeDeclType(D2);
            Context.Diag2(Base2->getLocStart(),
                          diag::note_odr_virtual_base)
              << Base2->isVirtual() << Base2->getSourceRange();
            Context.Diag1(Base1->getLocStart(), diag::note_odr_base)
              << Base1->isVirtual()
              << Base1->getSourceRange();
          }
          return false;
        }
      }
    } else if (D1CXX->getNumBases() > 0) {
      if (Context.Complain) {
        Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
          << Context.C2.getTypeDeclType(D2);
        const CXXBaseSpecifier *Base1 = D1CXX->bases_begin();
        Context.Diag1(Base1->getLocStart(), diag::note_odr_base)
          << Base1->getType()
          << Base1->getSourceRange();
        Context.Diag2(D2->getLocation(), diag::note_odr_missing_base);
      }
      return false;
    }
  }
  
  // Check the fields for consistency.
  RecordDecl::field_iterator Field2 = D2->field_begin(),
                             Field2End = D2->field_end();
  for (RecordDecl::field_iterator Field1 = D1->field_begin(),
                                  Field1End = D1->field_end();
       Field1 != Field1End;
       ++Field1, ++Field2) {
    if (Field2 == Field2End) {
      if (Context.Complain) {
        Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
          << Context.C2.getTypeDeclType(D2);
        Context.Diag1(Field1->getLocation(), diag::note_odr_field)
          << Field1->getDeclName() << Field1->getType();
        Context.Diag2(D2->getLocation(), diag::note_odr_missing_field);
      }
      return false;
    }
    
    if (!IsStructurallyEquivalent(Context, *Field1, *Field2))
      return false;    
  }
  
  if (Field2 != Field2End) {
    if (Context.Complain) {
      Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
        << Context.C2.getTypeDeclType(D2);
      Context.Diag2(Field2->getLocation(), diag::note_odr_field)
        << Field2->getDeclName() << Field2->getType();
      Context.Diag1(D1->getLocation(), diag::note_odr_missing_field);
    }
    return false;
  }
  
  return true;
}
     
/// \brief Determine structural equivalence of two enums.
static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     EnumDecl *D1, EnumDecl *D2) {
  EnumDecl::enumerator_iterator EC2 = D2->enumerator_begin(),
                             EC2End = D2->enumerator_end();
  for (EnumDecl::enumerator_iterator EC1 = D1->enumerator_begin(),
                                  EC1End = D1->enumerator_end();
       EC1 != EC1End; ++EC1, ++EC2) {
    if (EC2 == EC2End) {
      if (Context.Complain) {
        Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
          << Context.C2.getTypeDeclType(D2);
        Context.Diag1(EC1->getLocation(), diag::note_odr_enumerator)
          << EC1->getDeclName() 
          << EC1->getInitVal().toString(10);
        Context.Diag2(D2->getLocation(), diag::note_odr_missing_enumerator);
      }
      return false;
    }
    
    llvm::APSInt Val1 = EC1->getInitVal();
    llvm::APSInt Val2 = EC2->getInitVal();
    if (!llvm::APSInt::isSameValue(Val1, Val2) || 
        !IsStructurallyEquivalent(EC1->getIdentifier(), EC2->getIdentifier())) {
      if (Context.Complain) {
        Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
          << Context.C2.getTypeDeclType(D2);
        Context.Diag2(EC2->getLocation(), diag::note_odr_enumerator)
          << EC2->getDeclName() 
          << EC2->getInitVal().toString(10);
        Context.Diag1(EC1->getLocation(), diag::note_odr_enumerator)
          << EC1->getDeclName() 
          << EC1->getInitVal().toString(10);
      }
      return false;
    }
  }
  
  if (EC2 != EC2End) {
    if (Context.Complain) {
      Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
        << Context.C2.getTypeDeclType(D2);
      Context.Diag2(EC2->getLocation(), diag::note_odr_enumerator)
        << EC2->getDeclName() 
        << EC2->getInitVal().toString(10);
      Context.Diag1(D1->getLocation(), diag::note_odr_missing_enumerator);
    }
    return false;
  }
  
  return true;
}

static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     TemplateParameterList *Params1,
                                     TemplateParameterList *Params2) {
  if (Params1->size() != Params2->size()) {
    if (Context.Complain) {
      Context.Diag2(Params2->getTemplateLoc(), 
                    diag::err_odr_different_num_template_parameters)
        << Params1->size() << Params2->size();
      Context.Diag1(Params1->getTemplateLoc(), 
                    diag::note_odr_template_parameter_list);
    }
    return false;
  }
  
  for (unsigned I = 0, N = Params1->size(); I != N; ++I) {
    if (Params1->getParam(I)->getKind() != Params2->getParam(I)->getKind()) {
      if (Context.Complain) {
        Context.Diag2(Params2->getParam(I)->getLocation(), 
                      diag::err_odr_different_template_parameter_kind);
        Context.Diag1(Params1->getParam(I)->getLocation(),
                      diag::note_odr_template_parameter_here);
      }
      return false;
    }
    
    if (!Context.IsStructurallyEquivalent(Params1->getParam(I),
                                          Params2->getParam(I))) {
      
      return false;
    }
  }
  
  return true;
}

static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     TemplateTypeParmDecl *D1,
                                     TemplateTypeParmDecl *D2) {
  if (D1->isParameterPack() != D2->isParameterPack()) {
    if (Context.Complain) {
      Context.Diag2(D2->getLocation(), diag::err_odr_parameter_pack_non_pack)
        << D2->isParameterPack();
      Context.Diag1(D1->getLocation(), diag::note_odr_parameter_pack_non_pack)
        << D1->isParameterPack();
    }
    return false;
  }
  
  return true;
}

static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     NonTypeTemplateParmDecl *D1,
                                     NonTypeTemplateParmDecl *D2) {
  if (D1->isParameterPack() != D2->isParameterPack()) {
    if (Context.Complain) {
      Context.Diag2(D2->getLocation(), diag::err_odr_parameter_pack_non_pack)
        << D2->isParameterPack();
      Context.Diag1(D1->getLocation(), diag::note_odr_parameter_pack_non_pack)
        << D1->isParameterPack();
    }
    return false;
  }
  
  // Check types.
  if (!Context.IsStructurallyEquivalent(D1->getType(), D2->getType())) {
    if (Context.Complain) {
      Context.Diag2(D2->getLocation(),
                    diag::err_odr_non_type_parameter_type_inconsistent)
        << D2->getType() << D1->getType();
      Context.Diag1(D1->getLocation(), diag::note_odr_value_here)
        << D1->getType();
    }
    return false;
  }
  
  return true;
}

static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     TemplateTemplateParmDecl *D1,
                                     TemplateTemplateParmDecl *D2) {
  if (D1->isParameterPack() != D2->isParameterPack()) {
    if (Context.Complain) {
      Context.Diag2(D2->getLocation(), diag::err_odr_parameter_pack_non_pack)
        << D2->isParameterPack();
      Context.Diag1(D1->getLocation(), diag::note_odr_parameter_pack_non_pack)
        << D1->isParameterPack();
    }
    return false;
  }

  // Check template parameter lists.
  return IsStructurallyEquivalent(Context, D1->getTemplateParameters(),
                                  D2->getTemplateParameters());
}

static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     ClassTemplateDecl *D1, 
                                     ClassTemplateDecl *D2) {
  // Check template parameters.
  if (!IsStructurallyEquivalent(Context,
                                D1->getTemplateParameters(),
                                D2->getTemplateParameters()))
    return false;
  
  // Check the templated declaration.
  return Context.IsStructurallyEquivalent(D1->getTemplatedDecl(), 
                                          D2->getTemplatedDecl());
}

/// \brief Determine structural equivalence of two declarations.
static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                     Decl *D1, Decl *D2) {
  if (!D1 && !D2)
    return true;
  if (!D1 || !D2)
    return false;
  if (D1->getKind() != D1->getKind())
    return false;
  if (!D1->getLocStart().isInvalid())
    if (SourceLocationEqual(D1->getLocStart(),
                         D1->getASTContext().getSourceManager(),
                         D2->getLocStart(),
                         D2->getASTContext().getSourceManager()))
      if (!isa<ClassTemplateSpecializationDecl>(D1) &&
          !isa<VarTemplateSpecializationDecl>(D1))
        return true;
  if (NamedDecl *ND1 = dyn_cast<NamedDecl>(D1)) {
    NamedDecl *ND2 = dyn_cast<NamedDecl>(D2);
    if (ND1->getNameAsString() != ND2->getNameAsString())

        return false;
  }
  // FIXME: Check for known structural equivalences via a callback of some sort.
  
  // Check whether we already know that these two declarations are not
  // structurally equivalent.
  if (Context.NonEquivalentDecls.count(std::make_pair(D1->getCanonicalDecl(),
                                                      D2->getCanonicalDecl())))
    return false;
  
  // Determine whether we've already produced a tentative equivalence for D1.
  Decl *&EquivToD1 = Context.TentativeEquivalences[D1->getCanonicalDecl()];
  if (EquivToD1)
    return EquivToD1 == D2->getCanonicalDecl();
  
  // Produce a tentative equivalence D1 <-> D2, which will be checked later.
  EquivToD1 = D2->getCanonicalDecl();
  Context.DeclsToCheck.push_back(D1->getCanonicalDecl());
  return true;
}

bool StructuralEquivalenceContext::IsStructurallyEquivalent(Decl *D1, 
                                                            Decl *D2) {
  if (!::IsStructurallyEquivalent(*this, D1, D2))
    return false;
  
  return !Finish();
}

bool StructuralEquivalenceContext::IsStructurallyEquivalent(QualType T1,
                                                            QualType T2,
                                                            bool CheckQualifiers) {
  if (!::IsStructurallyEquivalent(*this, T1, T2, CheckQualifiers))
    return false;
  
  return !Finish();
}

static bool IsTemplateDeclStructurallyEquivalent(
    StructuralEquivalenceContext &Ctx, TemplateDecl *D1, TemplateDecl *D2) {
  if (!IsStructurallyEquivalent(D1->getIdentifier(), D2->getIdentifier()))
    return false;
  if (!D1->getIdentifier()) // Special name
    if (D1->getNameAsString() != D2->getNameAsString())
      return false;
  return IsStructurallyEquivalent(Ctx, D1->getTemplateParameters(),
                                  D2->getTemplateParameters());
}

bool StructuralEquivalenceContext::Finish() {
  while (!DeclsToCheck.empty()) {
    // Check the next declaration.
    Decl *D1 = DeclsToCheck.front();
    DeclsToCheck.pop_front();
    
    Decl *D2 = TentativeEquivalences[D1];
    assert(D2 && "Unrecorded tentative equivalence?");
    
    bool Equivalent = true;
    
    // FIXME: Switch on all declaration kinds. For now, we're just going to
    // check the obvious ones.
    if (RecordDecl *Record1 = dyn_cast<RecordDecl>(D1)) {
      if (RecordDecl *Record2 = dyn_cast<RecordDecl>(D2)) {
        // Check for equivalent structure names.
        IdentifierInfo *Name1 = Record1->getIdentifier();
        if (!Name1 && Record1->getTypedefNameForAnonDecl())
          Name1 = Record1->getTypedefNameForAnonDecl()->getIdentifier();
        IdentifierInfo *Name2 = Record2->getIdentifier();
        if (!Name2 && Record2->getTypedefNameForAnonDecl())
          Name2 = Record2->getTypedefNameForAnonDecl()->getIdentifier();
        if (!::IsStructurallyEquivalent(Name1, Name2) ||
            !::IsStructurallyEquivalent(*this, Record1, Record2))
          Equivalent = false;
      } else {
        // Record/non-record mismatch.
        Equivalent = false;
      }
    } else if (EnumDecl *Enum1 = dyn_cast<EnumDecl>(D1)) {
      if (EnumDecl *Enum2 = dyn_cast<EnumDecl>(D2)) {
        // Check for equivalent enum names.
        IdentifierInfo *Name1 = Enum1->getIdentifier();
        if (!Name1 && Enum1->getTypedefNameForAnonDecl())
          Name1 = Enum1->getTypedefNameForAnonDecl()->getIdentifier();
        IdentifierInfo *Name2 = Enum2->getIdentifier();
        if (!Name2 && Enum2->getTypedefNameForAnonDecl())
          Name2 = Enum2->getTypedefNameForAnonDecl()->getIdentifier();
        if (!::IsStructurallyEquivalent(Name1, Name2) ||
            !::IsStructurallyEquivalent(*this, Enum1, Enum2))
          Equivalent = false;
      } else {
        // Enum/non-enum mismatch
        Equivalent = false;
      }
    } else if (TypedefNameDecl *Typedef1 = dyn_cast<TypedefNameDecl>(D1)) {
      if (TypedefNameDecl *Typedef2 = dyn_cast<TypedefNameDecl>(D2)) {
        if (!::IsStructurallyEquivalent(Typedef1->getIdentifier(),
                                        Typedef2->getIdentifier()) ||
            !::IsStructurallyEquivalent(*this,
                                        Typedef1->getUnderlyingType(),
                                        Typedef2->getUnderlyingType()))
          Equivalent = false;
      } else {
        // Typedef/non-typedef mismatch.
        Equivalent = false;
      }
    } else if (ClassTemplateDecl *ClassTemplate1 
                                           = dyn_cast<ClassTemplateDecl>(D1)) {
      if (ClassTemplateDecl *ClassTemplate2 = dyn_cast<ClassTemplateDecl>(D2)) {
        if (!::IsTemplateDeclStructurallyEquivalent(*this, ClassTemplate1,
                                                    ClassTemplate2) ||
            !::IsStructurallyEquivalent(*this, ClassTemplate1,
                                        ClassTemplate2) ||
            !::IsStructurallyEquivalent(
              *this, ClassTemplate1->getTemplatedDecl(),
              ClassTemplate2->getTemplatedDecl()))
          Equivalent = false;
      } else {
        // Class template/non-class-template mismatch.
        Equivalent = false;
      }
    } else if (FunctionTemplateDecl *FunctionTemplate1 =
               dyn_cast<FunctionTemplateDecl>(D1)) {
      if (FunctionTemplateDecl *FunctionTemplate2 =
          dyn_cast<FunctionTemplateDecl>(D2)) {
        if (!::IsTemplateDeclStructurallyEquivalent(*this, FunctionTemplate1,
                                                    FunctionTemplate2) ||
            !::IsStructurallyEquivalent(*this, FunctionTemplate1,
                                        FunctionTemplate2) ||
            !::IsStructurallyEquivalent(
              *this, FunctionTemplate1->getTemplatedDecl()->getType(),
              FunctionTemplate2->getTemplatedDecl()->getType()))
          Equivalent = false;
      } else {
        // Class template/non-class-template mismatch.
        Equivalent = false;
      }
    } else if (TemplateTypeParmDecl *TTP1= dyn_cast<TemplateTypeParmDecl>(D1)) {
      if (TemplateTypeParmDecl *TTP2 = dyn_cast<TemplateTypeParmDecl>(D2)) {
        if (!::IsStructurallyEquivalent(*this, TTP1, TTP2))
          Equivalent = false;
      } else {
        // Kind mismatch.
        Equivalent = false;
      }
    } else if (NonTypeTemplateParmDecl *NTTP1
                                     = dyn_cast<NonTypeTemplateParmDecl>(D1)) {
      if (NonTypeTemplateParmDecl *NTTP2
                                      = dyn_cast<NonTypeTemplateParmDecl>(D2)) {
        if (!::IsStructurallyEquivalent(*this, NTTP1, NTTP2))
          Equivalent = false;
      } else {
        // Kind mismatch.
        Equivalent = false;
      }
    } else if (TemplateTemplateParmDecl *TTP1
                                  = dyn_cast<TemplateTemplateParmDecl>(D1)) {
      if (TemplateTemplateParmDecl *TTP2
                                    = dyn_cast<TemplateTemplateParmDecl>(D2)) {
        if (!::IsStructurallyEquivalent(*this, TTP1, TTP2))
          Equivalent = false;
      } else {
        // Kind mismatch.
        Equivalent = false;
      }
    } else if (FunctionDecl *FD1 = dyn_cast<FunctionDecl>(D1)) {
      if (FunctionDecl *FD2 = dyn_cast<FunctionDecl>(D2)) {
        if (!IsStructurallyEquivalent(FD1->getType(), FD2->getType())) {
          Equivalent = false;
        }
      } else {        // Kind mismatch.
        Equivalent = false;
      }
    }
    
    if (!Equivalent) {
      // Note that these two declarations are not equivalent (and we already
      // know about it).
      NonEquivalentDecls.insert(std::make_pair(D1->getCanonicalDecl(),
                                               D2->getCanonicalDecl()));
      return true;
    }
    // FIXME: Check other declaration kinds!
  }
  
  return false;
}

//----------------------------------------------------------------------------
// Import Types
//----------------------------------------------------------------------------

QualType ASTNodeImporter::VisitType(const Type *T) {
  Importer.FromDiag(SourceLocation(), diag::err_unsupported_ast_node)
    << T->getTypeClassName();
  return QualType();
}

QualType ASTNodeImporter::VisitAttributedType(const AttributedType *T) {
  QualType ToModType = Importer.Import(T->getModifiedType());
  if (ToModType.isNull()) {
    assert(!ToModType.isNull());
    return QualType();
  }

  QualType ToEqType = Importer.Import(T->getEquivalentType());
  if (ToEqType.isNull()) {
    assert(!ToEqType.isNull());
    return QualType();
  }

  return Importer.getToContext().getAttributedType(T->getAttrKind(), ToModType,
                                                   ToEqType);
}

QualType ASTNodeImporter::VisitBuiltinType(const BuiltinType *T) {
  switch (T->getKind()) {
#define SHARED_SINGLETON_TYPE(Expansion)
#define BUILTIN_TYPE(Id, SingletonId) \
  case BuiltinType::Id: return Importer.getToContext().SingletonId;
#include "clang/AST/BuiltinTypes.def"

  // FIXME: for Char16, Char32, and NullPtr, make sure that the "to"
  // context supports C++.

  // FIXME: for ObjCId, ObjCClass, and ObjCSel, make sure that the "to"
  // context supports ObjC.

  case BuiltinType::Char_U:
    // The context we're importing from has an unsigned 'char'. If we're 
    // importing into a context with a signed 'char', translate to 
    // 'unsigned char' instead.
    if (Importer.getToContext().getLangOpts().CharIsSigned)
      return Importer.getToContext().UnsignedCharTy;
    
    return Importer.getToContext().CharTy;

  case BuiltinType::Char_S:
    // The context we're importing from has an unsigned 'char'. If we're 
    // importing into a context with a signed 'char', translate to 
    // 'unsigned char' instead.
    if (!Importer.getToContext().getLangOpts().CharIsSigned)
      return Importer.getToContext().SignedCharTy;
    
    return Importer.getToContext().CharTy;

  case BuiltinType::WChar_S:
  case BuiltinType::WChar_U:
    // FIXME: If not in C++, shall we translate to the C equivalent of
    // wchar_t?
    return Importer.getToContext().WCharTy;
  }

  llvm_unreachable("Invalid BuiltinType Kind!");
}

QualType ASTNodeImporter::VisitDecayedType(const DecayedType *T) {
  QualType OrigT = Importer.Import(T->getOriginalType());
  if (OrigT.isNull())
    return QualType();

  return Importer.getToContext().getDecayedType(OrigT);
}

QualType ASTNodeImporter::VisitComplexType(const ComplexType *T) {
  QualType ToElementType = Importer.Import(T->getElementType());
  if (ToElementType.isNull())
    return QualType();
  
  return Importer.getToContext().getComplexType(ToElementType);
}

QualType ASTNodeImporter::VisitPointerType(const PointerType *T) {
  QualType ToPointeeType = Importer.Import(T->getPointeeType());
  if (ToPointeeType.isNull())
    return QualType();
  
  return Importer.getToContext().getPointerType(ToPointeeType);
}

QualType ASTNodeImporter::VisitBlockPointerType(const BlockPointerType *T) {
  // FIXME: Check for blocks support in "to" context.
  QualType ToPointeeType = Importer.Import(T->getPointeeType());
  if (ToPointeeType.isNull())
    return QualType();
  
  return Importer.getToContext().getBlockPointerType(ToPointeeType);
}

QualType
ASTNodeImporter::VisitLValueReferenceType(const LValueReferenceType *T) {
  // FIXME: Check for C++ support in "to" context.
  QualType ToPointeeType = Importer.Import(T->getPointeeTypeAsWritten());
  if (ToPointeeType.isNull())
    return QualType();
  
  return Importer.getToContext().getLValueReferenceType(ToPointeeType);
}

QualType
ASTNodeImporter::VisitRValueReferenceType(const RValueReferenceType *T) {
  // FIXME: Check for C++0x support in "to" context.
  QualType ToPointeeType = Importer.Import(T->getPointeeTypeAsWritten());
  if (ToPointeeType.isNull())
    return QualType();
  
  return Importer.getToContext().getRValueReferenceType(ToPointeeType);  
}

QualType ASTNodeImporter::VisitMemberPointerType(const MemberPointerType *T) {
  // FIXME: Check for C++ support in "to" context.
  QualType ToPointeeType = Importer.Import(T->getPointeeType());
  if (ToPointeeType.isNull())
    return QualType();
  
  QualType ClassType = Importer.Import(QualType(T->getClass(), 0));
  return Importer.getToContext().getMemberPointerType(ToPointeeType, 
                                                      ClassType.getTypePtr());
}

QualType ASTNodeImporter::VisitConstantArrayType(const ConstantArrayType *T) {
  QualType ToElementType = Importer.Import(T->getElementType());
  if (ToElementType.isNull())
    return QualType();
  
  return Importer.getToContext().getConstantArrayType(ToElementType, 
                                                      T->getSize(),
                                                      T->getSizeModifier(),
                                               T->getIndexTypeCVRQualifiers());
}

QualType
ASTNodeImporter::VisitIncompleteArrayType(const IncompleteArrayType *T) {
  QualType ToElementType = Importer.Import(T->getElementType());
  if (ToElementType.isNull())
    return QualType();
  
  return Importer.getToContext().getIncompleteArrayType(ToElementType, 
                                                        T->getSizeModifier(),
                                                T->getIndexTypeCVRQualifiers());
}

QualType ASTNodeImporter::VisitVariableArrayType(const VariableArrayType *T) {
  QualType ToElementType = Importer.Import(T->getElementType());
  if (ToElementType.isNull())
    return QualType();

  Expr *Size = Importer.Import(T->getSizeExpr());
  if (!Size)
    return QualType();
  
  SourceRange Brackets = Importer.Import(T->getBracketsRange());
  return Importer.getToContext().getVariableArrayType(ToElementType, Size,
                                                      T->getSizeModifier(),
                                                T->getIndexTypeCVRQualifiers(),
                                                      Brackets);
}

QualType ASTNodeImporter::VisitDependentSizedArrayType(
    const DependentSizedArrayType *T) {
  QualType ToElementType = Importer.Import(T->getElementType());
  assert(!ToElementType.isNull());
  if (ToElementType.isNull())
    return QualType();

  // SizeExpr may be null if size is not specified directly
  // For example, 'int a[]'
  Expr *Size = Importer.Import(T->getSizeExpr());
  assert(Size || !T->getSizeExpr());
  if (!Size && T->getSizeExpr())
    return QualType();

  SourceRange Brackets = Importer.Import(T->getBracketsRange());
  return Importer.getToContext().getDependentSizedArrayType(
        ToElementType, Size, T->getSizeModifier(),
        T->getIndexTypeCVRQualifiers(), Brackets);
}

QualType ASTNodeImporter::VisitVectorType(const VectorType *T) {
  QualType ToElementType = Importer.Import(T->getElementType());
  if (ToElementType.isNull())
    return QualType();
  
  return Importer.getToContext().getVectorType(ToElementType, 
                                               T->getNumElements(),
                                               T->getVectorKind());
}

QualType ASTNodeImporter::VisitExtVectorType(const ExtVectorType *T) {
  QualType ToElementType = Importer.Import(T->getElementType());
  if (ToElementType.isNull())
    return QualType();
  
  return Importer.getToContext().getExtVectorType(ToElementType, 
                                                  T->getNumElements());
}

QualType
ASTNodeImporter::VisitFunctionNoProtoType(const FunctionNoProtoType *T) {
  // FIXME: What happens if we're importing a function without a prototype 
  // into C++? Should we make it variadic?
  QualType ToResultType = Importer.Import(T->getResultType());
  if (ToResultType.isNull())
    return QualType();

  return Importer.getToContext().getFunctionNoProtoType(ToResultType,
                                                        T->getExtInfo());
}

QualType ASTNodeImporter::VisitFunctionProtoType(const FunctionProtoType *T) {
  QualType ToResultType = Importer.Import(T->getResultType());
  if (ToResultType.isNull())
    return QualType();
  
  // Import argument types
  SmallVector<QualType, 4> ArgTypes;
  for (FunctionProtoType::arg_type_iterator A = T->arg_type_begin(),
                                         AEnd = T->arg_type_end();
       A != AEnd; ++A) {
    QualType ArgType = Importer.Import(*A);
    if (ArgType.isNull())
      return QualType();
    ArgTypes.push_back(ArgType);
  }
  
  // Import exception types
  SmallVector<QualType, 4> ExceptionTypes;
  for (FunctionProtoType::exception_iterator E = T->exception_begin(),
                                          EEnd = T->exception_end();
       E != EEnd; ++E) {
    QualType ExceptionType = Importer.Import(*E);
    if (ExceptionType.isNull())
      return QualType();
    ExceptionTypes.push_back(ExceptionType);
  }

  FunctionProtoType::ExtProtoInfo FromEPI = T->getExtProtoInfo();
  FunctionProtoType::ExtProtoInfo ToEPI;

  ToEPI.ExtInfo = FromEPI.ExtInfo;
  ToEPI.Variadic = FromEPI.Variadic;
  ToEPI.HasTrailingReturn = FromEPI.HasTrailingReturn;
  ToEPI.TypeQuals = FromEPI.TypeQuals;
  ToEPI.RefQualifier = FromEPI.RefQualifier;
  ToEPI.NumExceptions = ExceptionTypes.size();
  ToEPI.Exceptions = ExceptionTypes.data();
  ToEPI.ConsumedArguments = FromEPI.ConsumedArguments;
  ToEPI.ExceptionSpecType = FromEPI.ExceptionSpecType;
  ToEPI.NoexceptExpr = Importer.Import(FromEPI.NoexceptExpr);
  ToEPI.ExceptionSpecDecl = cast_or_null<FunctionDecl>(
                                Importer.Import(FromEPI.ExceptionSpecDecl));
  ToEPI.ExceptionSpecTemplate = cast_or_null<FunctionDecl>(
                                Importer.Import(FromEPI.ExceptionSpecTemplate));

  return Importer.getToContext().getFunctionType(ToResultType, ArgTypes, ToEPI);
}

QualType ASTNodeImporter::VisitUnresolvedUsingType(
    const UnresolvedUsingType *T) {
  UnresolvedUsingTypenameDecl *ToD = cast_or_null<UnresolvedUsingTypenameDecl>(
        Importer.Import(T->getDecl()));
  if (!ToD) {
    assert(ToD);
    return QualType();
  }

  UnresolvedUsingTypenameDecl *ToPrevD =
      cast_or_null<UnresolvedUsingTypenameDecl>(
        Importer.Import(T->getDecl()->getPreviousDecl()));
  if (!ToPrevD && T->getDecl()->getPreviousDecl()) {
    assert(ToPrevD || !T->getDecl()->getPreviousDecl());
    return QualType();
  }

  return Importer.getToContext().getTypeDeclType(ToD, ToPrevD);
}


QualType ASTNodeImporter::VisitParenType(const ParenType *T) {
  QualType ToInnerType = Importer.Import(T->getInnerType());
  if (ToInnerType.isNull())
    return QualType();
    
  return Importer.getToContext().getParenType(ToInnerType);
}

QualType ASTNodeImporter::VisitTypedefType(const TypedefType *T) {
  TypedefNameDecl *ToDecl
             = dyn_cast_or_null<TypedefNameDecl>(Importer.Import(T->getDecl()));
  if (!ToDecl)
    return QualType();
  
  return Importer.getToContext().getTypeDeclType(ToDecl);
}

QualType ASTNodeImporter::VisitTypeOfExprType(const TypeOfExprType *T) {
  Expr *ToExpr = Importer.Import(T->getUnderlyingExpr());
  if (!ToExpr)
    return QualType();
  
  return Importer.getToContext().getTypeOfExprType(ToExpr);
}

QualType ASTNodeImporter::VisitTypeOfType(const TypeOfType *T) {
  QualType ToUnderlyingType = Importer.Import(T->getUnderlyingType());
  if (ToUnderlyingType.isNull())
    return QualType();
  
  return Importer.getToContext().getTypeOfType(ToUnderlyingType);
}

QualType ASTNodeImporter::VisitDecltypeType(const DecltypeType *T) {
  // FIXME: Make sure that the "to" context supports C++0x!
  Expr *ToExpr = Importer.Import(T->getUnderlyingExpr());
  if (!ToExpr)
    return QualType();
  
  QualType UnderlyingType = Importer.Import(T->getUnderlyingType());
  if (UnderlyingType.isNull())
    return QualType();

  return Importer.getToContext().getDecltypeType(ToExpr, UnderlyingType);
}

QualType ASTNodeImporter::VisitUnaryTransformType(const UnaryTransformType *T) {
  QualType ToBaseType = Importer.Import(T->getBaseType());
  QualType ToUnderlyingType = Importer.Import(T->getUnderlyingType());
  if (ToBaseType.isNull() || ToUnderlyingType.isNull())
    return QualType();

  return Importer.getToContext().getUnaryTransformType(ToBaseType,
                                                       ToUnderlyingType,
                                                       T->getUTTKind());
}

QualType ASTNodeImporter::VisitAutoType(const AutoType *T) {
  // FIXME: Make sure that the "to" context supports C++11!
  QualType FromDeduced = T->getDeducedType();
  QualType ToDeduced;
  if (!FromDeduced.isNull()) {
    ToDeduced = Importer.Import(FromDeduced);
    if (ToDeduced.isNull())
      return QualType();
  }
  
  return Importer.getToContext().getAutoType(ToDeduced, T->isDecltypeAuto(), 
                                             /*IsDependent*/false);
}

QualType ASTNodeImporter::VisitInjectedClassNameType(
    const InjectedClassNameType *T) {
  CXXRecordDecl *D = cast_or_null<CXXRecordDecl>(Importer.Import(T->getDecl()));
  assert(D);
  if (!D)
    return QualType();

  QualType InjType = Importer.Import(T->getInjectedSpecializationType());
  if (InjType.isNull())
    return QualType();

  // FIXME: ASTContext::getInjectedClassNameType is not suitable for AST reading
  // See Type.h:3855 for details
  // return Importer.getToContext().getInjectedClassNameType(D, InjType);
  enum {
    TypeAlignmentInBits = 4,
    TypeAlignment = 1 << TypeAlignmentInBits
  };

  return QualType(new (Importer.getToContext(), TypeAlignment)
                  InjectedClassNameType(D, InjType), 0);
}

QualType ASTNodeImporter::VisitRecordType(const RecordType *T) {
  RecordDecl *ToDecl
    = dyn_cast_or_null<RecordDecl>(Importer.Import(T->getDecl()));
  if (!ToDecl)
    return QualType();

  return Importer.getToContext().getTagDeclType(ToDecl);
}

QualType ASTNodeImporter::VisitEnumType(const EnumType *T) {
  EnumDecl *ToDecl
    = dyn_cast_or_null<EnumDecl>(Importer.Import(T->getDecl()));
  if (!ToDecl)
    return QualType();

  return Importer.getToContext().getTagDeclType(ToDecl);
}

QualType ASTNodeImporter::VisitTemplateTypeParmType(
    const TemplateTypeParmType *T) {
  return Importer.getToContext().getTemplateTypeParmType(
        T->getDepth(), T->getIndex(), T->isParameterPack(),
        cast_or_null<TemplateTypeParmDecl>(Importer.Import(T->getDecl())));
}

QualType ASTNodeImporter::VisitSubstTemplateTypeParmType(
    const SubstTemplateTypeParmType *T) {
  const TemplateTypeParmType *Replaced =
      cast_or_null<TemplateTypeParmType>(Importer.Import(
        QualType(T->getReplacedParameter(), 0)).getTypePtr());
  assert(Replaced);
  if (!Replaced)
    return QualType();

  QualType Replacement = Importer.Import(T->getReplacementType());
  assert(!Replacement.isNull());
  if (Replacement.isNull())
    return QualType();
  Replacement = Replacement.getCanonicalType();

  return Importer.getToContext().getSubstTemplateTypeParmType(
        Replaced, Replacement);
}

QualType ASTNodeImporter::VisitTemplateSpecializationType(
                                       const TemplateSpecializationType *T) {
  TemplateName ToTemplate = Importer.Import(T->getTemplateName());
  if (ToTemplate.isNull())
    return QualType();
  
  SmallVector<TemplateArgument, 2> ToTemplateArgs;
  if (ImportTemplateArguments(T->getArgs(), T->getNumArgs(), ToTemplateArgs))
    return QualType();
  
  QualType ToCanonType;
  if (!QualType(T, 0).isCanonical()) {
    QualType FromCanonType 
      = Importer.getFromContext().getCanonicalType(QualType(T, 0));
    ToCanonType =Importer.Import(FromCanonType);
    if (ToCanonType.isNull())
      return QualType();
  }
  return Importer.getToContext().getTemplateSpecializationType(ToTemplate, 
                                                         ToTemplateArgs.data(), 
                                                         ToTemplateArgs.size(),
                                                               ToCanonType);
}

QualType ASTNodeImporter::VisitElaboratedType(const ElaboratedType *T) {
  NestedNameSpecifier *ToQualifier = 0;
  // Note: the qualifier in an ElaboratedType is optional.
  if (T->getQualifier()) {
    ToQualifier = Importer.Import(T->getQualifier());
    if (!ToQualifier)
      return QualType();
  }

  QualType ToNamedType = Importer.Import(T->getNamedType());
  if (ToNamedType.isNull())
    return QualType();

  return Importer.getToContext().getElaboratedType(T->getKeyword(),
                                                   ToQualifier, ToNamedType);
}

QualType ASTNodeImporter::VisitDependentNameType(const DependentNameType *T) {
  NestedNameSpecifier *NNS = Importer.Import(T->getQualifier());
  assert(NNS || !T->getQualifier());
  if (!NNS && T->getQualifier())
    return QualType();

  IdentifierInfo *Name = Importer.Import(T->getIdentifier());
  assert(Name);
  if (!Name)
    return QualType();

  // Can be null type
  QualType Canon = (T == T->getCanonicalTypeInternal().getTypePtr())
      ? QualType()
      : Importer.Import(T->getCanonicalTypeInternal());
  if (!Canon.isNull())
    Canon = Canon.getCanonicalType();

  return Importer.getToContext().getDependentNameType(
        T->getKeyword(), NNS, Name, Canon);
}

QualType ASTNodeImporter::VisitPackExpansionType(const PackExpansionType *T) {
  QualType Pattern = Importer.Import(T->getPattern());
  assert(!Pattern.isNull());
  if (Pattern.isNull())
    return QualType();

  return Importer.getToContext().getPackExpansionType(Pattern,
                                                      T->getNumExpansions());
}

QualType ASTNodeImporter::VisitDependentTemplateSpecializationType(
    const DependentTemplateSpecializationType *T) {
  NestedNameSpecifier *Qualifier = Importer.Import(T->getQualifier());
  assert(Qualifier || !T->getQualifier());
  if (!Qualifier && T->getQualifier())
    return QualType();

  IdentifierInfo *Name = Importer.Import(T->getIdentifier());
  assert(Name || !T->getIdentifier());
  if (!Name && T->getIdentifier())
    return QualType();

  SmallVector<TemplateArgument, 2> ToPack;
  ToPack.reserve(T->getNumArgs());
  if (ImportTemplateArguments(T->getArgs(), T->getNumArgs(), ToPack)) {
    assert(false);
    return QualType();
  }

  return Importer.getToContext().getDependentTemplateSpecializationType(
        T->getKeyword(), Qualifier, Name, T->getNumArgs(), ToPack.data());
}

QualType ASTNodeImporter::VisitObjCInterfaceType(const ObjCInterfaceType *T) {
  ObjCInterfaceDecl *Class
    = dyn_cast_or_null<ObjCInterfaceDecl>(Importer.Import(T->getDecl()));
  if (!Class)
    return QualType();

  return Importer.getToContext().getObjCInterfaceType(Class);
}

QualType ASTNodeImporter::VisitObjCObjectType(const ObjCObjectType *T) {
  QualType ToBaseType = Importer.Import(T->getBaseType());
  if (ToBaseType.isNull())
    return QualType();

  SmallVector<ObjCProtocolDecl *, 4> Protocols;
  for (ObjCObjectType::qual_iterator P = T->qual_begin(), 
                                     PEnd = T->qual_end();
       P != PEnd; ++P) {
    ObjCProtocolDecl *Protocol
      = dyn_cast_or_null<ObjCProtocolDecl>(Importer.Import(*P));
    if (!Protocol)
      return QualType();
    Protocols.push_back(Protocol);
  }

  return Importer.getToContext().getObjCObjectType(ToBaseType,
                                                   Protocols.data(),
                                                   Protocols.size());
}

QualType
ASTNodeImporter::VisitObjCObjectPointerType(const ObjCObjectPointerType *T) {
  QualType ToPointeeType = Importer.Import(T->getPointeeType());
  if (ToPointeeType.isNull())
    return QualType();

  return Importer.getToContext().getObjCObjectPointerType(ToPointeeType);
}

//----------------------------------------------------------------------------
// Import Declarations
//----------------------------------------------------------------------------
bool ASTNodeImporter::ImportDeclParts(NamedDecl *D, DeclContext *&DC, 
                                      DeclContext *&LexicalDC, 
                                      DeclarationName &Name, 
                                      SourceLocation &Loc) {
  // Import the context of this declaration.
  DC = Importer.ImportContext(D->getDeclContext());
  if (!DC)
    return true;
  
  LexicalDC = DC;
  if (D->getDeclContext() != D->getLexicalDeclContext()) {
    LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
    if (!LexicalDC)
      return true;
  }
  
  // Import the name of this declaration.
  Name = Importer.Import(D->getDeclName());
  if (D->getDeclName() && !Name)
    return true;
  
  // Import the location of this declaration.
  Loc = Importer.Import(D->getLocation());
  return false;
}

void ASTNodeImporter::ImportDefinitionIfNeeded(Decl *FromD, Decl *ToD) {
  if (!FromD)
    return;
  
  if (!ToD) {
    ToD = Importer.Import(FromD);
    if (!ToD)
      return;
  }
  
  if (RecordDecl *FromRecord = dyn_cast<RecordDecl>(FromD)) {
    if (RecordDecl *ToRecord = cast_or_null<RecordDecl>(ToD)) {
      if (FromRecord->getDefinition() && FromRecord->isCompleteDefinition() && !ToRecord->getDefinition()) {
        ImportDefinition(FromRecord, ToRecord);
      }
    }
    return;
  }

  if (EnumDecl *FromEnum = dyn_cast<EnumDecl>(FromD)) {
    if (EnumDecl *ToEnum = cast_or_null<EnumDecl>(ToD)) {
      if (FromEnum->getDefinition() && !ToEnum->getDefinition()) {
        ImportDefinition(FromEnum, ToEnum);
      }
    }
    return;
  }
}

void
ASTNodeImporter::ImportDeclarationNameLoc(const DeclarationNameInfo &From,
                                          DeclarationNameInfo& To) {
  // NOTE: To.Name and To.Loc are already imported.
  // We only have to import To.LocInfo.
  switch (To.getName().getNameKind()) {
  case DeclarationName::Identifier:
  case DeclarationName::ObjCZeroArgSelector:
  case DeclarationName::ObjCOneArgSelector:
  case DeclarationName::ObjCMultiArgSelector:
  case DeclarationName::CXXUsingDirective:
    return;

  case DeclarationName::CXXOperatorName: {
    SourceRange Range = From.getCXXOperatorNameRange();
    To.setCXXOperatorNameRange(Importer.Import(Range));
    return;
  }
  case DeclarationName::CXXLiteralOperatorName: {
    SourceLocation Loc = From.getCXXLiteralOperatorNameLoc();
    To.setCXXLiteralOperatorNameLoc(Importer.Import(Loc));
    return;
  }
  case DeclarationName::CXXConstructorName:
  case DeclarationName::CXXDestructorName:
  case DeclarationName::CXXConversionFunctionName: {
    TypeSourceInfo *FromTInfo = From.getNamedTypeInfo();
    To.setNamedTypeInfo(Importer.Import(FromTInfo));
    return;
  }
  }
  llvm_unreachable("Unknown name kind.");
}

bool ASTNodeImporter::ImportDefinition(FunctionDecl *From, FunctionDecl *To) {
  To->setBody(Importer.Import(From->getBody()));

  CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(From);
  if (!CD)
    return false;

  unsigned NumInitializers = CD->getNumCtorInitializers();
  if (!NumInitializers)
    return false;

  ASTContext &Context = Importer.getToContext();
  CXXCtorInitializer **CtorInitializers = new (Context)
      CXXCtorInitializer*[NumInitializers];

  int cnt = 0;
  for (CXXConstructorDecl::init_iterator I = CD->init_begin(),
       E = CD->init_end(); I != E; ++I) {
    CXXCtorInitializer *Init = *I;
    TypeSourceInfo *TInfo = 0;
    bool IsBaseVirtual = false;
    FieldDecl *Member = 0;
    IndirectFieldDecl *IndirectMember = 0;

    if (Init->isBaseInitializer()) {
      TInfo = Importer.Import(Init->getTypeSourceInfo());
      IsBaseVirtual = Init->isBaseVirtual();
    } else if (Init->isDelegatingInitializer()) {
      TInfo = Importer.Import(Init->getTypeSourceInfo());
    } else if (Init->isMemberInitializer()) {
      Member = cast_or_null<FieldDecl>(Importer.Import(Init->getMember()));
      assert(Member);
      if (!Member)
        return true;
    } else if (Init->isIndirectMemberInitializer()) {
      IndirectMember = cast_or_null<IndirectFieldDecl>(
            Importer.Import(Init->getIndirectMember()));
      assert(IndirectMember);
      if (!IndirectMember)
        return true;
    }

    SourceLocation MemberOrEllipsisLoc =
        Importer.Import(Init->getMemberLocation());
    Expr *InitE = Importer.Import(Init->getInit());
    assert(InitE || !Init->getInit());
    if (!InitE && Init->getInit())
      return true;
    SourceLocation LParenLoc = Importer.Import(Init->getLParenLoc());
    SourceLocation RParenLoc = Importer.Import(Init->getRParenLoc());

    bool IsWritten = Init->isWritten();
    unsigned SourceOrderOrNumArrayIndices;
    SmallVector<VarDecl *, 8> Indices;
    SourceOrderOrNumArrayIndices = Init->getNumArrayIndices();
    if (!IsWritten) {
      Indices.reserve(SourceOrderOrNumArrayIndices);
      for (unsigned i = 0; i != SourceOrderOrNumArrayIndices; ++i) {
        VarDecl *VD = cast_or_null<VarDecl>(Init->getArrayIndex(i));
        assert(VD);
        if (!VD)
          return true;
        else
          Indices.push_back(VD);
      }
    }

    CXXCtorInitializer *ToInit;
    if (Init->isBaseInitializer()) {
      ToInit = new (Context) CXXCtorInitializer(
            Context, TInfo, IsBaseVirtual, LParenLoc, InitE, RParenLoc,
            MemberOrEllipsisLoc);
    } else if (Init->isDelegatingInitializer()) {
      ToInit = new (Context) CXXCtorInitializer(
            Context, TInfo, LParenLoc, InitE, RParenLoc);
    } else if (IsWritten) {
      if (Member)
        ToInit = new (Context) CXXCtorInitializer(
              Context, Member, MemberOrEllipsisLoc, LParenLoc, InitE,
              RParenLoc);
      else
        ToInit = new (Context) CXXCtorInitializer(
              Context, IndirectMember, MemberOrEllipsisLoc, LParenLoc,
              InitE, RParenLoc);
    } else {
      if (IndirectMember) {
        assert(Indices.empty() && "Indirect field improperly initialized");
        ToInit = new (Context) CXXCtorInitializer(
              Context, IndirectMember, MemberOrEllipsisLoc, LParenLoc,
              InitE, RParenLoc);
      } else {
        ToInit = CXXCtorInitializer::Create(
              Context, Member, MemberOrEllipsisLoc, LParenLoc,
              InitE, RParenLoc, Indices.data(), Indices.size());
      }
    }

    if (IsWritten)
      ToInit->setSourceOrder(SourceOrderOrNumArrayIndices);
    CtorInitializers[cnt] = ToInit;
    cnt++;
  }

  CXXConstructorDecl *ToCD = cast<CXXConstructorDecl>(To);
  ToCD->setCtorInitializers(CtorInitializers);
  ToCD->setNumCtorInitializers(NumInitializers);
  return false;
}

void ASTNodeImporter::ImportDeclContext(DeclContext *FromDC, bool ForceImport) {  
  if (Importer.isMinimalImport() && !ForceImport) {
    Importer.ImportContext(FromDC);
    return;
  }
  
  for (DeclContext::decl_iterator From = FromDC->decls_begin(),
                               FromEnd = FromDC->decls_end();
       From != FromEnd;
       ++From)
    Importer.Import(*From);

  // Reorder declarations in RecordDecls because they may have another
  // valuable order
  if (!isa<RecordDecl>(FromDC))
    return;

  DeclContext *ToDC = cast_or_null<DeclContext>(
        Importer.Import(cast<Decl>(FromDC)));
  for (DeclContext::decl_iterator From = FromDC->decls_begin(),
       FromEnd = FromDC->decls_end(); From != FromEnd; ++From) {
    Decl *To = Importer.GetImported(*From);
    assert(To);
    if (ToDC == To->getDeclContext() && ToDC->containsDecl(To))
      ToDC->removeDecl(To);
  }

  assert(cast<RecordDecl>(ToDC)->field_empty());

  for (DeclContext::decl_iterator From = FromDC->decls_begin(),
       FromEnd = FromDC->decls_end(); From != FromEnd; ++From) {
    Decl *To = Importer.GetImported(*From);
    assert(To);
    if (ToDC == To->getDeclContext() && ToDC == To->getLexicalDeclContext() &&
        !ToDC->containsDecl(To))
      ToDC->addDeclInternal(To);
  }
}

bool ASTNodeImporter::ImportDefinition(RecordDecl *From, RecordDecl *To, 
                                       ImportDefinitionKind Kind) {
  if (To->getDefinition() || To->isBeingDefined()) {
    if (Kind == IDK_Everything)
      ImportDeclContext(From, /*ForceImport=*/true);
    
    return false;
  }
  
  To->startDefinition();
  
  // Add base classes.
  if (CXXRecordDecl *ToCXX = dyn_cast<CXXRecordDecl>(To)) {
    if (CXXRecordDecl *FromCXX = dyn_cast<CXXRecordDecl>(From)) {

      struct CXXRecordDecl::DefinitionData &ToData = ToCXX->data();
      struct CXXRecordDecl::DefinitionData &FromData = FromCXX->data();
      ToData.UserDeclaredConstructor = FromData.UserDeclaredConstructor;
      ToData.UserDeclaredSpecialMembers = FromData.UserDeclaredSpecialMembers;
      ToData.Aggregate = true;
      ToData.PlainOldData = FromData.PlainOldData;
      ToData.Empty = FromData.Empty;
      ToData.Polymorphic = FromData.Polymorphic;
      ToData.Abstract = FromData.Abstract;
      ToData.IsStandardLayout = FromData.IsStandardLayout;
      ToData.HasNoNonEmptyBases = FromData.HasNoNonEmptyBases;
      ToData.HasPrivateFields = FromData.HasPrivateFields;
      ToData.HasProtectedFields = FromData.HasProtectedFields;
      ToData.HasPublicFields = FromData.HasPublicFields;
      ToData.HasMutableFields = FromData.HasMutableFields;
      ToData.HasOnlyCMembers = FromData.HasOnlyCMembers;
      ToData.HasInClassInitializer = FromData.HasInClassInitializer;
      ToData.HasUninitializedReferenceMember
        = FromData.HasUninitializedReferenceMember;
      ToData.NeedOverloadResolutionForMoveConstructor
        = FromData.NeedOverloadResolutionForMoveConstructor;
      ToData.NeedOverloadResolutionForMoveAssignment
        = FromData.NeedOverloadResolutionForMoveAssignment;
      ToData.NeedOverloadResolutionForDestructor
        = FromData.NeedOverloadResolutionForDestructor;
      ToData.DefaultedMoveConstructorIsDeleted
        = FromData.DefaultedMoveConstructorIsDeleted;
      ToData.DefaultedMoveAssignmentIsDeleted
        = FromData.DefaultedMoveAssignmentIsDeleted;
      ToData.DefaultedDestructorIsDeleted = FromData.DefaultedDestructorIsDeleted;
      ToData.HasTrivialSpecialMembers = FromData.HasTrivialSpecialMembers;
      ToData.HasIrrelevantDestructor = FromData.HasIrrelevantDestructor;
      ToData.HasConstexprNonCopyMoveConstructor
        = FromData.HasConstexprNonCopyMoveConstructor;
      ToData.DefaultedDefaultConstructorIsConstexpr
        = FromData.DefaultedDefaultConstructorIsConstexpr;
      ToData.HasConstexprDefaultConstructor
        = FromData.HasConstexprDefaultConstructor;
      ToData.HasNonLiteralTypeFieldsOrBases
        = FromData.HasNonLiteralTypeFieldsOrBases;
      // ComputedVisibleConversions not imported.
      ToData.UserProvidedDefaultConstructor
        = FromData.UserProvidedDefaultConstructor;
      ToData.DeclaredSpecialMembers = FromData.DeclaredSpecialMembers;
      ToData.ImplicitCopyConstructorHasConstParam
        = FromData.ImplicitCopyConstructorHasConstParam;
      ToData.ImplicitCopyAssignmentHasConstParam
        = FromData.ImplicitCopyAssignmentHasConstParam;
      ToData.HasDeclaredCopyConstructorWithConstParam
        = FromData.HasDeclaredCopyConstructorWithConstParam;
      ToData.HasDeclaredCopyAssignmentWithConstParam
        = FromData.HasDeclaredCopyAssignmentWithConstParam;
      ToData.IsLambda = FromData.IsLambda;
      ToData.Definition = cast<CXXRecordDecl>(
            Importer.Import(FromData.Definition));

      SmallVector<CXXBaseSpecifier *, 4> Bases;
      for (CXXRecordDecl::base_class_iterator
                    Base1 = FromCXX->bases_begin(),
              FromBaseEnd = FromCXX->bases_end();
           Base1 != FromBaseEnd;
           ++Base1) {
        QualType T = Importer.Import(Base1->getType());
        if (T.isNull())
          return true;

        SourceLocation EllipsisLoc;
        if (Base1->isPackExpansion())
          EllipsisLoc = Importer.Import(Base1->getEllipsisLoc());

        // Ensure that we have a definition for the base.
        ImportDefinitionIfNeeded(Base1->getType()->getAsCXXRecordDecl());

        Bases.push_back(Importer.Import(Base1));
      }
      if (!Bases.empty())
        ToCXX->setBases(Bases.data(), Bases.size());

      if (!FromCXX->getDestructor() &&
          FromCXX->needsImplicitDefaultConstructor() &&
          !FromCXX->isDependentType()) {
        Importer.getFromSema()->DeclareImplicitDestructor(FromCXX);
      }
    } else {
      // We're importing RecordDecl as CXXRecordDecl. That is normal sometimes.
      // Don't change anything in default ToData.
    }
  }
  
  if (shouldForceImportDeclContext(Kind))
    ImportDeclContext(From, /*ForceImport=*/true);
  
  To->completeDefinition();
  return false;
}

bool ASTNodeImporter::ImportDefinition(VarDecl *From, VarDecl *To,
                                       ImportDefinitionKind Kind) {
  // FIXME: Can we really import any initializer? Alternatively, we could force
  // ourselves to import every declaration of a variable and then only use
  // getInit() here.
  To->setInit(Importer.Import(const_cast<Expr *>(From->getAnyInitializer())));

  // FIXME: Other bits to merge?

  return false;
}

bool ASTNodeImporter::ImportDefinition(EnumDecl *From, EnumDecl *To, 
                                       ImportDefinitionKind Kind) {
  if (To->getDefinition() || To->isBeingDefined()) {
    if (Kind == IDK_Everything)
      ImportDeclContext(From, /*ForceImport=*/true);
    return false;
  }
  
  To->startDefinition();

  QualType T = Importer.Import(Importer.getFromContext().getTypeDeclType(From));
  if (T.isNull())
    return true;
  
  QualType ToPromotionType = Importer.Import(From->getPromotionType());
  if (ToPromotionType.isNull())
    return true;

  if (shouldForceImportDeclContext(Kind))
    ImportDeclContext(From, /*ForceImport=*/true);
  
  // FIXME: we might need to merge the number of positive or negative bits
  // if the enumerator lists don't match.
  To->completeDefinition(T, ToPromotionType,
                         From->getNumPositiveBits(),
                         From->getNumNegativeBits());
  return false;
}

TemplateParameterList *ASTNodeImporter::ImportTemplateParameterList(
                                                TemplateParameterList *Params) {
  SmallVector<NamedDecl *, 4> ToParams;
  ToParams.reserve(Params->size());
  for (TemplateParameterList::iterator P = Params->begin(), 
                                    PEnd = Params->end();
       P != PEnd; ++P) {
    Decl *To = Importer.Import(*P);
    if (!To)
      return 0;
    
    ToParams.push_back(cast<NamedDecl>(To));
  }
  
  return TemplateParameterList::Create(Importer.getToContext(),
                                       Importer.Import(Params->getTemplateLoc()),
                                       Importer.Import(Params->getLAngleLoc()),
                                       ToParams.data(), ToParams.size(),
                                       Importer.Import(Params->getRAngleLoc()));
}

TemplateArgument 
ASTNodeImporter::ImportTemplateArgument(const TemplateArgument &From) {
  switch (From.getKind()) {
  case TemplateArgument::Null:
    return TemplateArgument();
     
  case TemplateArgument::Type: {
    QualType ToType = Importer.Import(From.getAsType());
    if (ToType.isNull())
      return TemplateArgument();
    return TemplateArgument(ToType);
  }
      
  case TemplateArgument::Integral: {
    QualType ToType = Importer.Import(From.getIntegralType());
    if (ToType.isNull())
      return TemplateArgument();
    return TemplateArgument(From, ToType);
  }

  case TemplateArgument::Declaration: {
    ValueDecl *FromD = From.getAsDecl();
    if (ValueDecl *To = cast_or_null<ValueDecl>(Importer.Import(FromD)))
      return TemplateArgument(To, From.isDeclForReferenceParam());
    return TemplateArgument();
  }

  case TemplateArgument::NullPtr: {
    QualType ToType = Importer.Import(From.getNullPtrType());
    if (ToType.isNull())
      return TemplateArgument();
    return TemplateArgument(ToType, /*isNullPtr*/true);
  }

  case TemplateArgument::Template: {
    TemplateName ToTemplate = Importer.Import(From.getAsTemplate());
    if (ToTemplate.isNull())
      return TemplateArgument();
    
    return TemplateArgument(ToTemplate);
  }

  case TemplateArgument::TemplateExpansion: {
    TemplateName ToTemplate 
      = Importer.Import(From.getAsTemplateOrTemplatePattern());
    if (ToTemplate.isNull())
      return TemplateArgument();
    
    return TemplateArgument(ToTemplate, From.getNumTemplateExpansions());
  }

  case TemplateArgument::Expression:
    if (Expr *ToExpr = Importer.Import(From.getAsExpr()))
      return TemplateArgument(ToExpr);
    return TemplateArgument();
      
  case TemplateArgument::Pack: {
    SmallVector<TemplateArgument, 2> ToPack;
    ToPack.reserve(From.pack_size());
    if (ImportTemplateArguments(From.pack_begin(), From.pack_size(), ToPack))
      return TemplateArgument();
    
    TemplateArgument *ToArgs 
      = new (Importer.getToContext()) TemplateArgument[ToPack.size()];
    std::copy(ToPack.begin(), ToPack.end(), ToArgs);
    return TemplateArgument(ToArgs, ToPack.size());
  }
  }
  
  llvm_unreachable("Invalid template argument kind");
}

TemplateArgumentLoc ASTNodeImporter::ImportTemplateArgumentLoc(
    const TemplateArgumentLoc &TALoc) {
  TemplateArgument Arg = ImportTemplateArgument(TALoc.getArgument());
  TemplateArgumentLocInfo FromInfo = TALoc.getLocInfo();
  TemplateArgumentLocInfo ToInfo;
  if (Arg.getKind() == TemplateArgument::Expression) {
    Expr *E = Importer.Import(FromInfo.getAsExpr());
    assert(E);
    ToInfo = TemplateArgumentLocInfo(E);
  } else if (Arg.getKind() == TemplateArgument::Type) {
    TypeSourceInfo *TSI = Importer.Import(FromInfo.getAsTypeSourceInfo());
    assert(TSI);
    ToInfo = TemplateArgumentLocInfo(TSI);
  } else {
    ToInfo = TemplateArgumentLocInfo(
          Importer.Import(FromInfo.getTemplateQualifierLoc()),
          Importer.Import(FromInfo.getTemplateNameLoc()),
          Importer.Import(FromInfo.getTemplateEllipsisLoc()));
  }
  return TemplateArgumentLoc(Arg, ToInfo);
}

bool ASTNodeImporter::ImportTemplateArguments(const TemplateArgument *FromArgs,
                                              unsigned NumFromArgs,
                              SmallVectorImpl<TemplateArgument> &ToArgs) {
  for (unsigned I = 0; I != NumFromArgs; ++I) {
    TemplateArgument To = ImportTemplateArgument(FromArgs[I]);
    if (To.isNull() && !FromArgs[I].isNull())
      return true;
    
    ToArgs.push_back(To);
  }
  
  return false;
}

bool ASTNodeImporter::IsStructuralMatch(RecordDecl *FromRecord, 
                                        RecordDecl *ToRecord, bool Complain) {
  // Eliminate a potential failure point where we attempt to re-import
  // something we're trying to import while completing ToRecord.
  Decl *ToOrigin = Importer.GetOriginalDecl(ToRecord);
  if (ToOrigin) {
    RecordDecl *ToOriginRecord = dyn_cast<RecordDecl>(ToOrigin);
    if (ToOriginRecord)
      ToRecord = ToOriginRecord;
  }

  StructuralEquivalenceContext Ctx(Importer.getFromContext(),
                                   ToRecord->getASTContext(),
                                   Importer.getNonEquivalentDecls(),
                                   false, Complain);
  return Ctx.IsStructurallyEquivalent(FromRecord, ToRecord);
}

bool ASTNodeImporter::IsStructuralMatch(VarDecl *FromVar, VarDecl *ToVar,
                                        bool Complain) {
  StructuralEquivalenceContext Ctx(
      Importer.getFromContext(), Importer.getToContext(),
      Importer.getNonEquivalentDecls(), false, Complain);
  return Ctx.IsStructurallyEquivalent(FromVar, ToVar);
}

bool ASTNodeImporter::IsStructuralMatch(EnumDecl *FromEnum, EnumDecl *ToEnum) {
  StructuralEquivalenceContext Ctx(Importer.getFromContext(),
                                   Importer.getToContext(),
                                   Importer.getNonEquivalentDecls());
  return Ctx.IsStructurallyEquivalent(FromEnum, ToEnum);
}

bool ASTNodeImporter::IsStructuralMatch(EnumConstantDecl *FromEC,
                                        EnumConstantDecl *ToEC)
{
  const llvm::APSInt &FromVal = FromEC->getInitVal();
  const llvm::APSInt &ToVal = ToEC->getInitVal();

  return FromVal.isSigned() == ToVal.isSigned() &&
         FromVal.getBitWidth() == ToVal.getBitWidth() &&
         FromVal == ToVal;
}

bool ASTNodeImporter::IsStructuralMatch(ClassTemplateDecl *From,
                                        ClassTemplateDecl *To,
                                        bool Complain) {
  StructuralEquivalenceContext Ctx(Importer.getFromContext(),
                                   Importer.getToContext(),
                                   Importer.getNonEquivalentDecls(),
                                   false, Complain);
  return Ctx.IsStructurallyEquivalent(From, To);  
}

bool ASTNodeImporter::IsStructuralMatch(FunctionTemplateDecl *From,
                                        FunctionTemplateDecl *To) {
  StructuralEquivalenceContext Ctx(Importer.getFromContext(),
                                   Importer.getToContext(),
                                   Importer.getNonEquivalentDecls(),
                                   false, false);
  return Ctx.IsStructurallyEquivalent(From, To);
}

bool ASTNodeImporter::IsStructuralMatch(VarTemplateDecl *From,
                                        VarTemplateDecl *To) {
  StructuralEquivalenceContext Ctx(Importer.getFromContext(),
                                   Importer.getToContext(),
                                   Importer.getNonEquivalentDecls());
  return Ctx.IsStructurallyEquivalent(From, To);
}

Decl *ASTNodeImporter::VisitDecl(Decl *D) {
  Importer.FromDiag(D->getLocation(), diag::err_unsupported_ast_node)
    << D->getDeclKindName();
  return 0;
}

Decl *ASTNodeImporter::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
  TranslationUnitDecl *ToD = 
    Importer.getToContext().getTranslationUnitDecl();
    
  Importer.Imported(D, ToD);
    
  return ToD;
}

Decl *ASTNodeImporter::VisitEmptyDecl(EmptyDecl *D) {
  // Does anybody know how to import it correctly?
  // Import the context of this declaration.
  DeclContext *DC = Importer.ImportContext(D->getDeclContext());
  assert(DC);
  if (!DC)
    return NULL;

  DeclContext *LexicalDC = DC;
  if (D->getDeclContext() != D->getLexicalDeclContext()) {
    LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
    assert(LexicalDC);
    if (!LexicalDC)
      return NULL;
  }

  // Import the location of this declaration.
  SourceLocation Loc = Importer.Import(D->getLocation());

  EmptyDecl *ToD = EmptyDecl::Create(Importer.getToContext(), DC, Loc);
  ToD->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(ToD);
  return ToD;
}

Decl *ASTNodeImporter::VisitNamespaceDecl(NamespaceDecl *D) {
  // Import the major distinguishing characteristics of this namespace.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;
  
  NamespaceDecl *MergeWithNamespace = 0;
  if (!Name) {
    // This is an anonymous namespace. Adopt an existing anonymous
    // namespace if we can.
    // FIXME: Not testable.
    if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(DC))
      MergeWithNamespace = TU->getAnonymousNamespace();
    else
      MergeWithNamespace = cast<NamespaceDecl>(DC)->getAnonymousNamespace();
  } else {
    SmallVector<NamedDecl *, 4> ConflictingDecls;
    SmallVector<NamedDecl *, 2> FoundDecls;
    DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
    for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
      if (!FoundDecls[I]->isInIdentifierNamespace(Decl::IDNS_Namespace))
        continue;
      
      if (NamespaceDecl *FoundNS = dyn_cast<NamespaceDecl>(FoundDecls[I])) {
        MergeWithNamespace = FoundNS;
        ConflictingDecls.clear();
        break;
      }
      
      ConflictingDecls.push_back(FoundDecls[I]);
    }
    
    if (!ConflictingDecls.empty()) {
      Name = Importer.HandleNameConflict(Name, DC, Decl::IDNS_Namespace,
                                         ConflictingDecls.data(), 
                                         ConflictingDecls.size());
    }
  }
  
  // Create the "to" namespace, if needed.
  NamespaceDecl *ToNamespace = MergeWithNamespace;
  if (!ToNamespace) {
    ToNamespace = NamespaceDecl::Create(Importer.getToContext(), DC,
                                        D->isInline(),
                                        Importer.Import(D->getLocStart()),
                                        Loc, Name.getAsIdentifierInfo(),
                                        /*PrevDecl=*/0);
    
    // If this is an anonymous namespace, register it as the anonymous
    // namespace within its context.
    if (!Name) {
      if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(DC))
        TU->setAnonymousNamespace(ToNamespace);
      else
        cast<NamespaceDecl>(DC)->setAnonymousNamespace(ToNamespace);
    }

    Importer.Imported(D, ToNamespace);

    Decl *ToPrevD = Importer.Import(D->getPreviousDecl());
    assert(ToPrevD || !D->getPreviousDecl());
    // Setting a previous declaration to NULL explicitly resets all redeclaration
    // chains already built
    if (ToPrevD && ToPrevD != ToNamespace) {
      ToNamespace->setPreviousDecl(cast_or_null<NamespaceDecl>(ToPrevD));
    }
    ToNamespace->AnonOrFirstNamespaceAndInline.setPointer(
          ToNamespace->getFirstDecl());

    ToNamespace->setLexicalDeclContext(LexicalDC);
    LexicalDC->addDeclInternal(ToNamespace);
  }
  Importer.Imported(D, ToNamespace);

  ImportDeclContext(D);

  ImportAttributes(D, ToNamespace);
  
  return ToNamespace;
}

Decl *ASTNodeImporter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
  // Import the major distinguishing characteristics of this namespace.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;


  // If this typedef is not in block scope, determine whether we've
  // seen a typedef with the same name (that we can merge with) or any
  // other entity by that name (which name lookup could conflict with).
  if (!DC->isFunctionOrMethod()) {
    SmallVector<NamedDecl *, 4> ConflictingDecls;
    unsigned IDNS = Decl::IDNS_Ordinary;
    SmallVector<NamedDecl *, 2> FoundDecls;
    DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
    for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
      if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
        continue;
      if (NamespaceAliasDecl *FoundAlias=
            dyn_cast<NamespaceAliasDecl>(FoundDecls[I])) {
        // FIXME: Is check for POINTEE identifier is a solution?
        if (IsStructurallyEquivalent(D->getIdentifier(),
                                     FoundAlias->getIdentifier()))
          return Importer.Imported(D, FoundAlias);
      }

      ConflictingDecls.push_back(FoundDecls[I]);
    }

    if (!ConflictingDecls.empty()) {
      Name = Importer.HandleNameConflict(Name, DC, IDNS,
                                         ConflictingDecls.data(),
                                         ConflictingDecls.size());
      if (!Name) {
        assert(false);
        return NULL;
      }
    }
  }

  NamespaceDecl *TargetDecl = cast<NamespaceDecl>(
        Importer.Import(D->getNamespace()));
  assert(TargetDecl);
  if (!TargetDecl)
    return NULL;

  IdentifierInfo *ToII = Importer.Import(D->getIdentifier());
  if (!ToII) {
    assert(false);
    return NULL;
  }

  NestedNameSpecifierLoc ToQLoc = Importer.Import(D->getQualifierLoc());

  NamespaceAliasDecl *ToD = NamespaceAliasDecl::Create(
        Importer.getToContext(), DC, Importer.Import(D->getNamespaceLoc()),
        Importer.Import(D->getAliasLoc()), ToII, ToQLoc,
        Importer.Import(D->getTargetNameLoc()), TargetDecl);
  Importer.Imported(D, ToD);

  ImportAttributes(D, ToD);

  return ToD;
}

Decl *ASTNodeImporter::VisitStaticAssertDecl(StaticAssertDecl *D) {
  DeclContext *DC = Importer.ImportContext(D->getDeclContext());
  if (!DC)
    return NULL;

  DeclContext *LexicalDC = DC;
  if (D->getDeclContext() != D->getLexicalDeclContext()) {
    LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
    if (!LexicalDC)
      return NULL;
  }

  // Import the location of this declaration.
  SourceLocation Loc = Importer.Import(D->getLocation());

  Expr *AssertExpr = Importer.Import(D->getAssertExpr());
  assert(AssertExpr);
  if (!AssertExpr)
    return NULL;

  StringLiteral *Message = cast_or_null<StringLiteral>(
        Importer.Import(D->getMessage()));
  assert(Message);
  if (!Message)
    return NULL;

  StaticAssertDecl *ToD = StaticAssertDecl::Create(
        Importer.getToContext(), DC, Loc, AssertExpr, Message,
        Importer.Import(D->getRParenLoc()), D->isFailed());

  ToD->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(ToD);
  Importer.Imported(D, ToD);
  return ToD;
}

Decl *ASTNodeImporter::VisitAccessSpecDecl(AccessSpecDecl *D) {
  DeclContext *DC = Importer.ImportContext(D->getDeclContext());
  if (!DC)
    return NULL;

  DeclContext *LexicalDC = DC;
  if (D->getDeclContext() != D->getLexicalDeclContext()) {
    LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
    if (!LexicalDC)
      return NULL;
  }

  AccessSpecDecl *ToD = AccessSpecDecl::Create(
        Importer.getToContext(), D->getAccess(), DC,
        Importer.Import(D->getAccessSpecifierLoc()),
        Importer.Import(D->getColonLoc()));
  ToD->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(ToD);
  Importer.Imported(D, ToD);
  ImportAttributes(D, ToD);
  return ToD;
}

Decl *ASTNodeImporter::VisitTypedefNameDecl(TypedefNameDecl *D, bool IsAlias) {
  // Import the major distinguishing characteristics of this typedef.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;
  
  // If this typedef is not in block scope, determine whether we've
  // seen a typedef with the same name (that we can merge with) or any
  // other entity by that name (which name lookup could conflict with).
  if (!DC->isFunctionOrMethod()) {
    SmallVector<NamedDecl *, 4> ConflictingDecls;
    unsigned IDNS = Decl::IDNS_Ordinary;
    SmallVector<NamedDecl *, 2> FoundDecls;
    DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
    for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
      if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
        continue;
      if (TypedefNameDecl *FoundTypedef =
            dyn_cast<TypedefNameDecl>(FoundDecls[I])) {
        if (!FoundTypedef->getUnderlyingType()->isIncompleteType() &&
            Importer.IsStructurallyEquivalent(
              D->getUnderlyingType(), FoundTypedef->getUnderlyingType(),
              false, false))
          return Importer.Imported(D, FoundTypedef);
      }
      
      ConflictingDecls.push_back(FoundDecls[I]);
    }
    
    if (!ConflictingDecls.empty()) {
      Name = Importer.HandleNameConflict(Name, DC, IDNS,
                                         ConflictingDecls.data(), 
                                         ConflictingDecls.size());
      if (!Name)
        return 0;
    }
  }
  
  // Import the underlying type of this typedef;
  QualType T = Importer.Import(D->getUnderlyingType());
  if (T.isNull())
    return 0;
  
  // Create the new typedef node.
  TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
  SourceLocation StartL = Importer.Import(D->getLocStart());
  TypedefNameDecl *ToTypedef;
  if (IsAlias)
    ToTypedef = TypeAliasDecl::Create(Importer.getToContext(), DC,
                                      StartL, Loc,
                                      Name.getAsIdentifierInfo(),
                                      TInfo);
  else
    ToTypedef = TypedefDecl::Create(Importer.getToContext(), DC,
                                    StartL, Loc,
                                    Name.getAsIdentifierInfo(),
                                    TInfo);
  
  ImportAttributes(D, ToTypedef);
  ToTypedef->setAccess(D->getAccess());

  Importer.Imported(D, ToTypedef);

  ToTypedef->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(ToTypedef);

  return ToTypedef;
}

Decl *ASTNodeImporter::VisitTypedefDecl(TypedefDecl *D) {
  return VisitTypedefNameDecl(D, /*IsAlias=*/false);
}

Decl *ASTNodeImporter::VisitTypeAliasDecl(TypeAliasDecl *D) {
  return VisitTypedefNameDecl(D, /*IsAlias=*/true);
}

Decl *ASTNodeImporter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
  // Import the major distinguishing characteristics of this typedef.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;

  // If this typedef is not in block scope, determine whether we've
  // seen a typedef with the same name (that we can merge with) or any
  // other entity by that name (which name lookup could conflict with).
  if (!DC->isFunctionOrMethod()) {
    SmallVector<NamedDecl *, 4> ConflictingDecls;
    unsigned IDNS = Decl::IDNS_Ordinary;
    SmallVector<NamedDecl *, 2> FoundDecls;
    DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
    for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
      if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
        continue;
      if (TypeAliasTemplateDecl *FoundAlias =
            dyn_cast<TypeAliasTemplateDecl>(FoundDecls[I]))
          return Importer.Imported(D, FoundAlias);
      ConflictingDecls.push_back(FoundDecls[I]);
    }

    if (!ConflictingDecls.empty()) {
      Name = Importer.HandleNameConflict(Name, DC, IDNS,
                                         ConflictingDecls.data(),
                                         ConflictingDecls.size());
      if (!Name)
        return 0;
    }
  }

  TemplateParameterList *Params = ImportTemplateParameterList(
        D->getTemplateParameters());
  assert(Params);
  if (!Params)
    return NULL;

  NamedDecl *TemplDecl = cast<NamedDecl>(Importer.Import(D->getTemplatedDecl()));
  assert(TemplDecl);
  if (!TemplDecl)
    return NULL;

  TypeAliasTemplateDecl *ToD = TypeAliasTemplateDecl::Create(
        Importer.getToContext(), DC, Loc, Name, Params, TemplDecl);
  ImportAttributes(D, ToD);
  ToD->setAccess(D->getAccess());

  Importer.Imported(D, ToD);

  ToD->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(ToD);
  return ToD;
}

Decl *ASTNodeImporter::VisitLabelDecl(LabelDecl *D) {
  // Import the major distinguishing characteristics of this label.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;
  assert(LexicalDC->isFunctionOrMethod());

  LabelDecl *Res = NULL;
  if (D->isGnuLocal())
    Res = LabelDecl::Create(Importer.getToContext(),
                            DC, Importer.Import(D->getLocation()),
                            Name.getAsIdentifierInfo(),
                            Importer.Import(D->getLocStart()));
  else
    Res = LabelDecl::Create(Importer.getToContext(),
                            DC, Importer.Import(D->getLocation()),
                            Name.getAsIdentifierInfo());

  Importer.Imported(D, Res);
  Res->setStmt(cast<LabelStmt>(Importer.Import(D->getStmt())));
  Res->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(Res);
  ImportAttributes(D, Res);
  return Res;
}

Decl *ASTNodeImporter::VisitEnumDecl(EnumDecl *D) {
  // Import the major distinguishing characteristics of this enum.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;
  
  // Figure out what enum name we're looking for.
  unsigned IDNS = Decl::IDNS_Tag;
  DeclarationName SearchName = Name;
  if (!SearchName && D->getTypedefNameForAnonDecl()) {
    SearchName = Importer.Import(D->getTypedefNameForAnonDecl()->getDeclName());
    IDNS = Decl::IDNS_Ordinary;
  } else if (Importer.getToContext().getLangOpts().CPlusPlus)
    IDNS |= Decl::IDNS_Ordinary;
  
  // We may already have an enum of the same name; try to find and match it.
  if (!DC->isFunctionOrMethod() && SearchName) {
    SmallVector<NamedDecl *, 4> ConflictingDecls;
    SmallVector<NamedDecl *, 2> FoundDecls;
    DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
    for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
      if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
        continue;
      
      Decl *Found = FoundDecls[I];
      if (TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Found)) {
        if (const TagType *Tag = Typedef->getUnderlyingType()->getAs<TagType>())
          Found = Tag->getDecl();
      }
      
      if (EnumDecl *FoundEnum = dyn_cast<EnumDecl>(Found)) {
        if (IsStructuralMatch(D, FoundEnum))
          return Importer.Imported(D, FoundEnum);
      }
      
      ConflictingDecls.push_back(FoundDecls[I]);
    }
    
    if (!ConflictingDecls.empty()) {
      Name = Importer.HandleNameConflict(Name, DC, IDNS,
                                         ConflictingDecls.data(), 
                                         ConflictingDecls.size());
    }
  }
  
  // Create the enum declaration.
  EnumDecl *D2 = EnumDecl::Create(Importer.getToContext(), DC,
                                  Importer.Import(D->getLocStart()),
                                  Loc, Name.getAsIdentifierInfo(), 0,
                                  D->isScoped(), D->isScopedUsingClassTag(),
                                  D->isFixed());
  // Import the qualifier, if any.
  D2->setQualifierInfo(Importer.Import(D->getQualifierLoc()));
  ImportAttributes(D, D2);
  D2->setAccess(D->getAccess());

  Importer.Imported(D, D2);

  D2->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(D2);

  // Import the integer type.
  QualType ToIntegerType = Importer.Import(D->getIntegerType());
  // getIntegerType().isNull == true for forward enum declarations
  assert(!ToIntegerType.isNull() || D->getIntegerType().isNull());
  if (ToIntegerType.isNull() && !D->getIntegerType().isNull())
    return 0;
  D2->setIntegerType(ToIntegerType);
  
  // Import the definition
  if (D->isCompleteDefinition() && ImportDefinition(D, D2))
    return 0;

  if (MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo()) {
    TemplateSpecializationKind SK = MemberInfo->getTemplateSpecializationKind();
    EnumDecl *ND = cast_or_null<EnumDecl>(
          Importer.Import(D->getInstantiatedFromMemberEnum()));
    assert(ND);
    D2->setInstantiationOfMemberEnum(ND, SK);
    D2->getMemberSpecializationInfo()->setPointOfInstantiation(
          Importer.Import(MemberInfo->getPointOfInstantiation()));
  }

  return D2;
}

Decl *ASTNodeImporter::VisitRecordDecl(RecordDecl *D) {
  // If this record has a definition in the translation unit we're coming from,
  // but this particular declaration is not that definition, import the
  // definition and map to that.
  TagDecl *Definition = D->getDefinition();
  if (Definition && Definition != D) {
    Decl *ImportedDef = Importer.Import(Definition);
    if (!ImportedDef)
      return 0;

    return Importer.Imported(D, ImportedDef);
  }
  // Import the major distinguishing characteristics of this record.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;

  if (Decl *Imp = Importer.GetImported(D))
    return Imp;
      
  // Figure out what structure name we're looking for.
  unsigned IDNS = Decl::IDNS_Tag;
  DeclarationName SearchName = Name;
  if (!SearchName && D->getTypedefNameForAnonDecl()) {
    SearchName = Importer.Import(D->getTypedefNameForAnonDecl()->getDeclName());
    IDNS |= Decl::IDNS_Ordinary;
  } else if (Importer.getToContext().getLangOpts().CPlusPlus)
    IDNS |= Decl::IDNS_Ordinary;

  // We may already have a record of the same name; try to find and match it.
  RecordDecl *AdoptDecl = 0;
  if (!DC->isFunctionOrMethod()) {
    SmallVector<NamedDecl *, 4> ConflictingDecls;
    SmallVector<NamedDecl *, 2> FoundDecls;
    DC->getRedeclContext()->localUncachedLookup(SearchName, FoundDecls);
    for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
      if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
        continue;
      
      Decl *Found = FoundDecls[I];
      if (TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Found)) {
        if (const TagType *Tag = Typedef->getUnderlyingType()->getAs<TagType>())
          Found = Tag->getDecl();
      }
      
      if (RecordDecl *FoundRecord = dyn_cast<RecordDecl>(Found)) {
        if (D->isAnonymousStructOrUnion() && 
            FoundRecord->isAnonymousStructOrUnion()) {
          // If both anonymous structs/unions are in a record context, make sure
          // they occur in the same location in the context records.
          if (Optional<unsigned> Index1
              = findAnonymousStructOrUnionIndex(D)) {
            if (Optional<unsigned> Index2 =
                    findAnonymousStructOrUnionIndex(FoundRecord)) {
              if (*Index1 != *Index2)
                continue;
            }
          }
        }

        if (RecordDecl *FoundDef = FoundRecord->getDefinition()) {
          if ((SearchName && !D->isCompleteDefinition())
              || (D->isCompleteDefinition() &&
                  D->isAnonymousStructOrUnion()
                    == FoundDef->isAnonymousStructOrUnion() &&
                  IsStructuralMatch(D, FoundDef, false))) {
            // The record types structurally match, or the "from" translation
            // unit only had a forward declaration anyway; call it the same
            // function.
            // FIXME: For C++, we should also merge methods here.
            if (CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(FoundDef))
              if (!CRD->isDependentType() && CRD->needsImplicitDestructor() &&
                  !CRD->getDestructor())
                Importer.getToSema()->DeclareImplicitDestructor(CRD);
            return Importer.Imported(D, FoundDef);
          }
        } else if (!D->isCompleteDefinition()) {
          // We have a forward declaration of this type, so adopt that forward
          // declaration rather than building a new one.
          AdoptDecl = FoundRecord;
          continue;
        } else if (SearchName && D->isCompleteDefinition()) {
          // We have a complete declaration of this type, so adopt found forward
          // declaration rather than building a new one.
          AdoptDecl = FoundRecord;
          continue;
        } else if (!SearchName) {
          continue;
        }
      }
      
      ConflictingDecls.push_back(FoundDecls[I]);
    }
    
    if (!ConflictingDecls.empty() && SearchName) {
      Name = Importer.HandleNameConflict(Name, DC, IDNS,
                                         ConflictingDecls.data(), 
                                         ConflictingDecls.size());
    }
  }
  
  // Create the record declaration.
  RecordDecl *D2 = AdoptDecl;
  SourceLocation StartLoc = Importer.Import(D->getLocStart());
  if (!D2) {
    if (isa<CXXRecordDecl>(D) ||
        Importer.getToContext().getLangOpts().CPlusPlus) {
      CXXRecordDecl *D2CXX = CXXRecordDecl::Create(Importer.getToContext(), 
                                                   D->getTagKind(),
                                                   DC, StartLoc, Loc,
                                                   Name.getAsIdentifierInfo());
      D2 = D2CXX;
      D2->setAccess(D->getAccess());

      Importer.Imported(D, D2);

      if (CXXRecordDecl *FromCXX = dyn_cast<CXXRecordDecl>(D)) {
        if (ClassTemplateDecl *FromDescribed =
            FromCXX->getDescribedClassTemplate()) {
          ClassTemplateDecl *ToDescribed = cast_or_null<ClassTemplateDecl>(
                Importer.Import(FromDescribed));
          assert(ToDescribed);
          if (!ToDescribed)
            return NULL;
          D2CXX->setDescribedClassTemplate(ToDescribed);
        } else if (MemberSpecializationInfo *MemberInfo
                   = FromCXX->getMemberSpecializationInfo()) {
          TemplateSpecializationKind SK = MemberInfo->getTemplateSpecializationKind();
          CXXRecordDecl *RD = cast_or_null<CXXRecordDecl>(
                Importer.Import(FromCXX->getInstantiatedFromMemberClass()));
          assert(RD);
          D2CXX->setInstantiationOfMemberClass(RD, SK);
          D2CXX->getMemberSpecializationInfo()->setPointOfInstantiation(
                Importer.Import(MemberInfo->getPointOfInstantiation()));
        }
      }

    } else {
      D2 = RecordDecl::Create(Importer.getToContext(), D->getTagKind(),
                              DC, StartLoc, Loc, Name.getAsIdentifierInfo());
    }
    
    D2->setQualifierInfo(Importer.Import(D->getQualifierLoc()));
    if (D->isAnonymousStructOrUnion())
      D2->setAnonymousStructOrUnion(true);

    Importer.Imported(D, D2);

    D2->setLexicalDeclContext(LexicalDC);
    LexicalDC->addDeclInternal(D2);
  }
  
  ImportAttributes(D, D2);
  Importer.Imported(D, D2);
  D2->setImplicit(D->isImplicit());

  if (D->isCompleteDefinition() && ImportDefinition(D, D2, IDK_Default))
    return 0;
/*
  RecordDecl *Def = D->getDefinition();
  RecordDecl *ToDef = cast_or_null<RecordDecl>(Importer.Import(Def));
  assert(ToDef || !Def);
  if (Def && !ToDef)
    return 0;
*/
  return D2;
}

Decl *ASTNodeImporter::VisitEnumConstantDecl(EnumConstantDecl *D) {
  // Import the major distinguishing characteristics of this enumerator.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;

  QualType T = Importer.Import(D->getType());
  if (T.isNull())
    return 0;

  // Determine whether there are any other declarations with the same name and 
  // in the same context.
  if (!LexicalDC->isFunctionOrMethod()) {
    SmallVector<NamedDecl *, 4> ConflictingDecls;
    unsigned IDNS = Decl::IDNS_Ordinary;
    SmallVector<NamedDecl *, 2> FoundDecls;
    DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
    for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
      if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
        continue;

      if (EnumConstantDecl *FoundEnumConstant
            = dyn_cast<EnumConstantDecl>(FoundDecls[I])) {
        if (IsStructuralMatch(D, FoundEnumConstant))
          return Importer.Imported(D, FoundEnumConstant);
      }

      ConflictingDecls.push_back(FoundDecls[I]);
    }
    
    if (!ConflictingDecls.empty()) {
      Name = Importer.HandleNameConflict(Name, DC, IDNS,
                                         ConflictingDecls.data(), 
                                         ConflictingDecls.size());
      if (!Name)
        return 0;
    }
  }
  
  Expr *Init = Importer.Import(D->getInitExpr());
  if (D->getInitExpr() && !Init)
    return 0;
  
  EnumConstantDecl *ToEnumerator
    = EnumConstantDecl::Create(Importer.getToContext(), cast<EnumDecl>(DC), Loc, 
                               Name.getAsIdentifierInfo(), T, 
                               Init, D->getInitVal());
  ImportAttributes(D, ToEnumerator);
  ToEnumerator->setAccess(D->getAccess());
  ToEnumerator->setLexicalDeclContext(LexicalDC);
  Importer.Imported(D, ToEnumerator);
  LexicalDC->addDeclInternal(ToEnumerator);
  return ToEnumerator;
}

Decl *ASTNodeImporter::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
  // Import the major distinguishing characteristics of this function.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;

  // Try to find a function in our own ("to") context with the same name, same
  // type, and in the same context as the function we're importing.
  if (!LexicalDC->isFunctionOrMethod()) {
    unsigned IDNS = Decl::IDNS_Ordinary;
    SmallVector<NamedDecl *, 2> FoundDecls;
    DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
    for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
      if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
        continue;

      if (FunctionTemplateDecl *FoundFunction =
          dyn_cast<FunctionTemplateDecl>(FoundDecls[I])) {
        if (FoundFunction->hasExternalFormalLinkage() &&
            D->hasExternalFormalLinkage()) {
          if (IsStructuralMatch(D, FoundFunction)) {
            Importer.Imported(D, FoundFunction);
            // FIXME: Actually try to merge the body and other attributes.
            return FoundFunction;
          }
        }
      }
    }
  }

  std::vector<NamedDecl *> Decls;
  TemplateParameterList *SourceParamList = D->getTemplateParameters();
  for (TemplateParameterList::iterator I = SourceParamList->begin(),
       E = SourceParamList->end(); I != E; ++I) {
    if (NamedDecl *ND = cast_or_null<NamedDecl>(Importer.Import(*I)))
      Decls.push_back(ND);
    else {
      assert(false);
      return NULL;
    }
  }

  FunctionDecl *TemplatedFD = cast_or_null<FunctionDecl>(
        Importer.Import(D->getTemplatedDecl()));
  assert(TemplatedFD);
  if (!TemplatedFD)
    return NULL;

  FunctionTemplateDecl *ToFunction = FunctionTemplateDecl::Create(
        Importer.getToContext(), DC, Importer.Import(D->getLocation()), Name,
        TemplateParameterList::Create(
          Importer.getToContext(),
          Importer.Import(SourceParamList->getTemplateLoc()),
          Importer.Import(SourceParamList->getLAngleLoc()),
          Decls.data(), Decls.size(),
          Importer.Import(SourceParamList->getRAngleLoc())),
        TemplatedFD);

  TemplatedFD->setDescribedFunctionTemplate(ToFunction);
  ImportAttributes(D, ToFunction);
  ToFunction->setAccess(D->getAccess());
  ToFunction->setLexicalDeclContext(LexicalDC);
  Importer.Imported(D, ToFunction);

  // Add this function to the lexical context.
  LexicalDC->addDeclInternal(ToFunction);

  return ToFunction;
}

Decl *ASTNodeImporter::VisitFunctionDecl(FunctionDecl *D) {
  // Import the major distinguishing characteristics of this function.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;

  const FunctionDecl *FoundWithoutBody = NULL;

  // Try to find a function in our own ("to") context with the same name, same
  // type, and in the same context as the function we're importing.
  if (!LexicalDC->isFunctionOrMethod()) {
    SmallVector<NamedDecl *, 4> ConflictingDecls;
    unsigned IDNS = Decl::IDNS_Ordinary;
    SmallVector<NamedDecl *, 2> FoundDecls;
    DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
    for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
      if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
        continue;
    
      if (FunctionDecl *FoundFunction = dyn_cast<FunctionDecl>(FoundDecls[I])) {
        if (FoundFunction->hasExternalFormalLinkage() &&
            D->hasExternalFormalLinkage()) {
          if (Importer.IsStructurallyEquivalent(D->getType(), 
                                                FoundFunction->getType(),
                                                false)) {
            // FIXME: Actually try to merge the body and other attributes.
            const FunctionDecl *FromBodyDecl = NULL;
            D->hasBody(FromBodyDecl);
            if (D == FromBodyDecl && !FoundFunction->hasBody()) {
              // This function is needed to merge completely.
              FoundWithoutBody = FoundFunction;
              break;
            }
            Importer.Imported(D, FoundFunction);
            return FoundFunction;
          }
        
          // FIXME: Check for overloading more carefully, e.g., by boosting
          // Sema::IsOverload out to the AST library.
          
          // Function overloading is okay in C++.
          if (Importer.getToContext().getLangOpts().CPlusPlus ||
              Importer.getFromContext().getLangOpts().CPlusPlus)
            continue;
          
          // Complain about inconsistent function types.
          Importer.ToDiag(Loc, diag::err_odr_function_type_inconsistent)
            << Name << D->getType() << FoundFunction->getType();
          Importer.ToDiag(FoundFunction->getLocation(), 
                          diag::note_odr_value_here)
            << FoundFunction->getType();
        }
      }
      
      ConflictingDecls.push_back(FoundDecls[I]);
    }
    
    if (!ConflictingDecls.empty()) {
      Name = Importer.HandleNameConflict(Name, DC, IDNS,
                                         ConflictingDecls.data(), 
                                         ConflictingDecls.size());
      if (!Name)
        return 0;
    }    
  }

  DeclarationNameInfo NameInfo(Name, Loc);
  // Import additional name location/type info.
  ImportDeclarationNameLoc(D->getNameInfo(), NameInfo);

  QualType FromTy = D->getType();
  bool usedDifferentExceptionSpec = false;

  if (const FunctionProtoType *
        FromFPT = D->getType()->getAs<FunctionProtoType>()) {
    FunctionProtoType::ExtProtoInfo FromEPI = FromFPT->getExtProtoInfo();
    // FunctionProtoType::ExtProtoInfo's ExceptionSpecDecl can point to the
    // FunctionDecl that we are importing the FunctionProtoType for.
    // To avoid an infinite recursion when importing, create the FunctionDecl
    // with a simplified function type and update it afterwards.
    if (FromEPI.ExceptionSpecDecl || FromEPI.ExceptionSpecTemplate ||
        FromEPI.NoexceptExpr) {
      FunctionProtoType::ExtProtoInfo DefaultEPI;
      FromTy = Importer.getFromContext().getFunctionType(
          FromFPT->getResultType(), FromFPT->getArgTypes(), DefaultEPI);
      usedDifferentExceptionSpec = true;
    }
  }

  // Import the type.
  QualType T = Importer.Import(FromTy);
  if (T.isNull())
    return 0;
  
  // Import the function parameters.
  SmallVector<ParmVarDecl *, 8> Parameters;
  for (FunctionDecl::param_iterator P = D->param_begin(), PEnd = D->param_end();
       P != PEnd; ++P) {
    ParmVarDecl *ToP = cast_or_null<ParmVarDecl>(Importer.Import(*P));
    if (!ToP)
      return 0;
    
    Parameters.push_back(ToP);
  }
  
  // Create the imported function.
  TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
  FunctionDecl *ToFunction = 0;
  if (CXXConstructorDecl *FromConstructor = dyn_cast<CXXConstructorDecl>(D)) {
    ToFunction = CXXConstructorDecl::Create(Importer.getToContext(),
                                            cast<CXXRecordDecl>(DC),
                                            Importer.Import(D->getInnerLocStart()),
                                            NameInfo, T, TInfo,
                                            FromConstructor->isExplicit(),
                                            D->isInlineSpecified(), 
                                            D->isImplicit(),
                                            D->isConstexpr());
  } else if (isa<CXXDestructorDecl>(D)) {
    ToFunction = CXXDestructorDecl::Create(Importer.getToContext(),
                                           cast<CXXRecordDecl>(DC),
                                           Importer.Import(D->getInnerLocStart()),
                                           NameInfo, T, TInfo,
                                           D->isInlineSpecified(),
                                           D->isImplicit());
  } else if (CXXConversionDecl *FromConversion
                                           = dyn_cast<CXXConversionDecl>(D)) {
    ToFunction = CXXConversionDecl::Create(Importer.getToContext(), 
                                           cast<CXXRecordDecl>(DC),
                                           Importer.Import(D->getInnerLocStart()),
                                           NameInfo, T, TInfo,
                                           D->isInlineSpecified(),
                                           FromConversion->isExplicit(),
                                           D->isConstexpr(),
                                           Importer.Import(D->getLocEnd()));
  } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
    ToFunction = CXXMethodDecl::Create(Importer.getToContext(), 
                                       cast<CXXRecordDecl>(DC),
                                       Importer.Import(D->getInnerLocStart()),
                                       NameInfo, T, TInfo,
                                       Method->getCanonicalDecl()->getStorageClass(),
                                       Method->isInlineSpecified(),
                                       D->isConstexpr(),
                                       Importer.Import(D->getLocEnd()));
  } else {
    ToFunction = FunctionDecl::Create(Importer.getToContext(), DC,
                                      Importer.Import(D->getInnerLocStart()),
                                      NameInfo, T, TInfo,
                                      D->getCanonicalDecl()->getStorageClass(),
                                      D->isInlineSpecified(),
                                      D->hasWrittenPrototype(),
                                      D->isConstexpr());
  }

  // Import the qualifier, if any.
  ToFunction->setQualifierInfo(Importer.Import(D->getQualifierLoc()));
  ImportAttributes(D, ToFunction);
  ToFunction->setAccess(D->getAccess());
  ToFunction->setLexicalDeclContext(LexicalDC);
  ToFunction->setVirtualAsWritten(D->isVirtualAsWritten());
  ToFunction->setTrivial(D->isTrivial());
  ToFunction->setPure(D->isPure());
  Importer.Imported(D, ToFunction);

  // Set the parameters.
  for (unsigned I = 0, N = Parameters.size(); I != N; ++I)
    Parameters[I]->setOwningFunction(ToFunction);

  ToFunction->setParams(Parameters);

  if (usedDifferentExceptionSpec) {
    // Update FunctionProtoType::ExtProtoInfo.
    QualType T = Importer.Import(D->getType());
    if (T.isNull())
      return 0;
    ToFunction->setType(T);
  }

  // If it is a template, import all related things.
  switch (D->getTemplatedKind()) {
  case FunctionDecl::TK_NonTemplate:
    break;
  case FunctionDecl::TK_FunctionTemplate: {
    break;
  }
  case FunctionDecl::TK_MemberSpecialization: {
    FunctionDecl *InstFD = cast_or_null<FunctionDecl>(
          Importer.Import(D->getInstantiatedFromMemberFunction()));
    assert(InstFD);
    if (!InstFD)
      return NULL;
    TemplateSpecializationKind TSK = D->getTemplateSpecializationKind();
    SourceLocation POI = Importer.Import(D->getMemberSpecializationInfo()
                                         ->getPointOfInstantiation());
    ToFunction->setInstantiationOfMemberFunction(InstFD, TSK);
    ToFunction->getMemberSpecializationInfo()->setPointOfInstantiation(POI);
    break;
  }
  case FunctionDecl::TK_FunctionTemplateSpecialization: {
    FunctionTemplateSpecializationInfo *
      FTSInfo = D->getTemplateSpecializationInfo();
    FunctionTemplateDecl *Template = cast_or_null<FunctionTemplateDecl>(
          Importer.Import(FTSInfo->getTemplate()));
    TemplateSpecializationKind TSK = FTSInfo->getTemplateSpecializationKind();

    // Template arguments.
    llvm::ArrayRef<TemplateArgument> TemplArgs =
        FTSInfo->TemplateArguments->asArray();
    SmallVector<TemplateArgument, 8> ToTemplArgs;
    ImportTemplateArguments(TemplArgs.data(), TemplArgs.size(), ToTemplArgs);
    TemplateArgumentList *ToTAList = TemplateArgumentList::CreateCopy(
          Importer.getToContext(), ToTemplArgs.data(), ToTemplArgs.size());

    SourceLocation LAngleLoc, RAngleLoc;
    TemplateArgumentListInfo FromTAInfo, ToTAInfo;
    if (FTSInfo->TemplateArgumentsAsWritten) {
      // Import TemplateArgumentListInfo
      LAngleLoc = Importer.Import(FTSInfo->TemplateArgumentsAsWritten
                                  ->LAngleLoc);
      RAngleLoc = Importer.Import(FTSInfo->TemplateArgumentsAsWritten
                                  ->RAngleLoc);
      ToTAInfo = TemplateArgumentListInfo(LAngleLoc, RAngleLoc);
      FTSInfo->TemplateArgumentsAsWritten->copyInto(FromTAInfo);
      for (unsigned i = 0, e = FromTAInfo.size(); i < e; i++) {
        const TemplateArgumentLoc &FromLoc = FromTAInfo[i];
        ToTAInfo.addArgument(ImportTemplateArgumentLoc(FromLoc));
      }
    }

    SourceLocation POI = Importer.Import(FTSInfo->getPointOfInstantiation());

    FunctionTemplateSpecializationInfo *ToFTInfo =
        FunctionTemplateSpecializationInfo::Create(
          Importer.getToContext(), ToFunction, Template, TSK, ToTAList,
          FTSInfo->TemplateArgumentsAsWritten ? &ToTAInfo : 0, POI);
    ToFunction->TemplateOrSpecialization = ToFTInfo;
    break;
  }
  case FunctionDecl::TK_DependentFunctionTemplateSpecialization: {
    // Templates.
    DependentFunctionTemplateSpecializationInfo *FromInfo =
        D->getDependentSpecializationInfo();
    UnresolvedSet<8> TemplDecls;
    unsigned NumTemplates = FromInfo->getNumTemplates();
    for (unsigned i = 0; i < NumTemplates; i++)
      TemplDecls.addDecl(FromInfo->getTemplate(i));

    // Templates args.
    // Import TemplateArgumentListInfo
    SourceLocation LAngleLoc = Importer.Import(FromInfo->getLAngleLoc());
    SourceLocation RAngleLoc = Importer.Import(FromInfo->getRAngleLoc());
    TemplateArgumentListInfo ToTAInfo(LAngleLoc, RAngleLoc), FromTAInfo;
    for (unsigned i = 0, e = FromTAInfo.size(); i < e; i++) {
      const TemplateArgumentLoc &FromLoc = FromInfo->getTemplateArg(i);
      ToTAInfo.addArgument(ImportTemplateArgumentLoc(FromLoc));
    }

    ToFunction->setDependentTemplateSpecialization(
          Importer.getToContext(), TemplDecls, ToTAInfo);
    break;
  }
  }

  // Add this function to the lexical context.
  LexicalDC->addDeclInternal(ToFunction);

  const FunctionDecl *BodyDecl = NULL;
  D->hasBody(BodyDecl);
  if (D == BodyDecl)
    ImportDefinition(D, ToFunction);
  else if (BodyDecl) {
    Decl *ToDef = Importer.Import(const_cast<FunctionDecl *>(BodyDecl));
    assert(ToDef);
  }

  if (FoundWithoutBody) {
    FunctionDecl *Recent = const_cast<FunctionDecl *>(
          FoundWithoutBody->getMostRecentDecl());
    ToFunction->setPreviousDecl(Recent);
  }

  // FIXME: Other bits to merge?

  // Add overrided methods for MethodDecl
  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
    CXXMethodDecl *ToMD = cast<CXXMethodDecl>(ToFunction);
    if (ToMD->isCanonicalDecl()) {
      for (CXXMethodDecl::method_iterator I = MD->begin_overridden_methods(),
           E = MD->end_overridden_methods(); I != E; ++I) {
        // FIXME: refactor const_cast
        CXXMethodDecl *Overridden = cast_or_null<CXXMethodDecl>(
              Importer.Import(const_cast<CXXMethodDecl *>(*I)));
        assert(Overridden);
        if (!Overridden)
          return NULL;
        Importer.getToContext().addOverriddenMethod(
              ToMD, Overridden->getCanonicalDecl());
      }
    }
  }

  return ToFunction;
}

Decl *ASTNodeImporter::VisitCXXMethodDecl(CXXMethodDecl *D) {
  return VisitFunctionDecl(D);
}

Decl *ASTNodeImporter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
  return VisitCXXMethodDecl(D);
}

Decl *ASTNodeImporter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
  return VisitCXXMethodDecl(D);
}

Decl *ASTNodeImporter::VisitCXXConversionDecl(CXXConversionDecl *D) {
  return VisitCXXMethodDecl(D);
}

static unsigned getFieldIndex(Decl *F) {
  RecordDecl *Owner = dyn_cast<RecordDecl>(F->getDeclContext());
  if (!Owner)
    return 0;

  unsigned Index = 1;
  for (DeclContext::decl_iterator D = Owner->decls_begin(),
                               DEnd = Owner->decls_end();
       D != DEnd; ++D) {
    if (*D == F)
      return Index;

    if (isa<FieldDecl>(*D) || isa<IndirectFieldDecl>(*D))
      ++Index;
  }

  return Index;
}

Decl *ASTNodeImporter::VisitFieldDecl(FieldDecl *D) {
  // Import the major distinguishing characteristics of a variable.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;
  
  // Determine whether we've already imported this field. 
  SmallVector<NamedDecl *, 2> FoundDecls;
  DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
  for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
    if (FieldDecl *FoundField = dyn_cast<FieldDecl>(FoundDecls[I])) {
      // For anonymous fields, match up by index.
      if (!Name && getFieldIndex(D) != getFieldIndex(FoundField))
        continue;

      StructuralEquivalenceContext Ctx(Importer.getFromContext(),
                                       Importer.getToContext(),
                                       Importer.getNonEquivalentDecls());
      if (IsStructurallyEquivalent(Ctx, D, FoundField)) {
        Importer.Imported(D, FoundField);
        return FoundField;
      }
      Importer.ToDiag(Loc, diag::err_odr_field_type_inconsistent)
        << Name << D->getType() << FoundField->getType();
      Importer.ToDiag(FoundField->getLocation(), diag::note_odr_value_here)
        << FoundField->getType();
      return 0;
    }
  }

  // Lookup failed. Check if a name was redefined (see adb/sysdeps.h mess)
  // This is a workaround for cases where field names are redefined by a macro
  // so we need to import a field with another name.
  // We need to do this because we our RecordDecl maybe already in main TU
  // and have a complete layout. Adding a field to this RD is unacceptable.
  // We do it for fields only because it does not affect other cases
  // (just a new declaration is constructed).
  if (RecordDecl *RD = dyn_cast<RecordDecl>(DC)) {
    for (RecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end();
         I != E; ++I) {
      SourceManager &ToMgr = Importer.getToContext().getSourceManager();
      if (ToMgr.getSpellingLoc(I->getLocation()) != I->getLocation())
        // suddenly macro
        if (SourceLocationEqual(D->getLocation(),
                                Importer.getFromContext().getSourceManager(),
                                ToMgr.getExpansionLoc(I->getLocation()),
                                ToMgr)) {
          StructuralEquivalenceContext Ctx(Importer.getFromContext(),
                                           Importer.getToContext(),
                                           Importer.getNonEquivalentDecls());
          if (IsStructurallyEquivalent(Ctx, D->getType(), I->getType())) {
            Importer.Imported(D, *I);
            return *I;
          }
        }
    }
  }

  // Import the type.
  QualType T = Importer.Import(D->getType());
  if (T.isNull())
    return 0;
  
  TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
  Expr *BitWidth = Importer.Import(D->getBitWidth());
  if (!BitWidth && D->getBitWidth())
    return 0;

  if (Decl *Imp = Importer.GetImported(D))
    return Imp;
  
  FieldDecl *ToField = FieldDecl::Create(Importer.getToContext(), DC,
                                         Importer.Import(D->getInnerLocStart()),
                                         Loc, Name.getAsIdentifierInfo(),
                                         T, TInfo, BitWidth, D->isMutable(),
                                         D->getInClassInitStyle());
  ImportAttributes(D, ToField);

  AccessSpecifier AccessSpec = D->getAccess();
  if (isa<CXXRecordDecl>(DC) && !isa<CXXRecordDecl>(D->getDeclContext()))
    AccessSpec = AS_public;
  ToField->setAccess(AccessSpec);

  ToField->setLexicalDeclContext(LexicalDC);
  if (ToField->hasInClassInitializer())
    ToField->setInClassInitializer(Importer.Import(D->getInClassInitializer()));
  ToField->setImplicit(D->isImplicit());
  Importer.Imported(D, ToField);
  LexicalDC->addDeclInternal(ToField);
  return ToField;
}

Decl *ASTNodeImporter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
  // Import the major distinguishing characteristics of a variable.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;

  // Determine whether we've already imported this field. 
  SmallVector<NamedDecl *, 2> FoundDecls;
  DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
  for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
    if (IndirectFieldDecl *FoundField 
                                = dyn_cast<IndirectFieldDecl>(FoundDecls[I])) {
      // For anonymous indirect fields, match up by index.
      if (!Name && getFieldIndex(D) != getFieldIndex(FoundField))
        continue;

      if (Importer.IsStructurallyEquivalent(D->getType(), 
                                            FoundField->getType(),
                                            !Name.isEmpty())) {
        Importer.Imported(D, FoundField);
        return FoundField;
      }

      // If there are more anonymous fields to check, continue.
      if (!Name && I < N-1)
        continue;

      Importer.ToDiag(Loc, diag::err_odr_field_type_inconsistent)
        << Name << D->getType() << FoundField->getType();
      Importer.ToDiag(FoundField->getLocation(), diag::note_odr_value_here)
        << FoundField->getType();
      return 0;
    }
  }

  // Import the type.
  QualType T = Importer.Import(D->getType());
  if (T.isNull())
    return 0;

  NamedDecl **NamedChain =
    new (Importer.getToContext())NamedDecl*[D->getChainingSize()];

  unsigned i = 0;
  for (IndirectFieldDecl::chain_iterator PI = D->chain_begin(),
       PE = D->chain_end(); PI != PE; ++PI) {
    Decl* D = Importer.Import(*PI);
    if (!D)
      return 0;
    NamedChain[i++] = cast<NamedDecl>(D);
  }

  IndirectFieldDecl *ToIndirectField = IndirectFieldDecl::Create(
                                         Importer.getToContext(), DC,
                                         Loc, Name.getAsIdentifierInfo(), T,
                                         NamedChain, D->getChainingSize());

  ImportAttributes(D, ToIndirectField);

  AccessSpecifier AccessSpec = D->getAccess();
  if (isa<CXXRecordDecl>(DC) && !isa<CXXRecordDecl>(D->getDeclContext()))
    AccessSpec = AS_public;
  ToIndirectField->setAccess(AccessSpec);

  ToIndirectField->setLexicalDeclContext(LexicalDC);
  Importer.Imported(D, ToIndirectField);
  LexicalDC->addDeclInternal(ToIndirectField);
  return ToIndirectField;
}

Decl *ASTNodeImporter::VisitFriendDecl(FriendDecl *D) {
  // Import the major distinguishing characteristics of a variable.
  DeclContext *DC = Importer.ImportContext(D->getDeclContext());
  DeclContext *LexicalDC = D->getDeclContext() == D->getLexicalDeclContext()
      ? DC : Importer.ImportContext(D->getDeclContext());
  assert(DC && LexicalDC);
  if (!DC || !LexicalDC)
    return NULL;

  // Determine whether we've already imported this field.
  CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC);
  FriendDecl *ImportedFriend = RD->getFirstFriend();
  StructuralEquivalenceContext Context(
      Importer.getFromContext(), Importer.getToContext(),
      Importer.getNonEquivalentDecls(), false, false);
  while (ImportedFriend) {
    if (D->getFriendDecl() && ImportedFriend->getFriendDecl()) {
      if (Context.IsStructurallyEquivalent(D->getFriendDecl(),
                                           ImportedFriend->getFriendDecl()))
        return Importer.Imported(D, ImportedFriend);
    } else if (D->getFriendType() && ImportedFriend->getFriendType()) {
      if (Importer.IsStructurallyEquivalent(
            D->getFriendType()->getType(),
            ImportedFriend->getFriendType()->getType(), true, true))
        return Importer.Imported(D, ImportedFriend);
    }
    ImportedFriend = ImportedFriend->getNextFriend();
  }

  // Not found. Create it.
  FriendDecl::FriendUnion ToFU;
  if (NamedDecl *FriendD = D->getFriendDecl())
    ToFU = cast<NamedDecl>(Importer.Import(FriendD));
  else
    ToFU = Importer.Import(D->getFriendType());
  assert(ToFU);
  if (!ToFU)
    return NULL;

  SmallVector<TemplateParameterList *, 1> ToTPLists;
  ToTPLists.reserve(D->NumTPLists);
  TemplateParameterList **FromTPLists = D->getTPLists();
  for (int i = 0; i < D->NumTPLists; i++) {
    TemplateParameterList *List = ImportTemplateParameterList(FromTPLists[i]);
    assert(List);
    if (!List)
      return NULL;
    ToTPLists.push_back(List);
  }

  size_t Size = sizeof(FriendDecl)
    + ToTPLists.size() * sizeof(TemplateParameterList*);
  void *Mem = Importer.getToContext().Allocate(Size);
  FriendDecl *FrD = new (Mem) FriendDecl(DC, Importer.Import(D->getLocation()),
                                         ToFU,
                                         Importer.Import(D->getFriendLoc()),
                                         ToTPLists);

  Importer.Imported(D, FrD);
  RD->pushFriendDecl(FrD);

  ImportAttributes(D, FrD);
  FrD->setAccess(D->getAccess());
  FrD->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(FrD);
  // Seems like we don't need to set NextFriend
  return FrD;
}

Decl *ASTNodeImporter::VisitObjCIvarDecl(ObjCIvarDecl *D) {
  // Import the major distinguishing characteristics of an ivar.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;
  
  // Determine whether we've already imported this ivar 
  SmallVector<NamedDecl *, 2> FoundDecls;
  DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
  for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
    if (ObjCIvarDecl *FoundIvar = dyn_cast<ObjCIvarDecl>(FoundDecls[I])) {
      if (Importer.IsStructurallyEquivalent(D->getType(), 
                                            FoundIvar->getType())) {
        Importer.Imported(D, FoundIvar);
        return FoundIvar;
      }

      Importer.ToDiag(Loc, diag::err_odr_ivar_type_inconsistent)
        << Name << D->getType() << FoundIvar->getType();
      Importer.ToDiag(FoundIvar->getLocation(), diag::note_odr_value_here)
        << FoundIvar->getType();
      return 0;
    }
  }

  // Import the type.
  QualType T = Importer.Import(D->getType());
  if (T.isNull())
    return 0;
  
  TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
  Expr *BitWidth = Importer.Import(D->getBitWidth());
  if (!BitWidth && D->getBitWidth())
    return 0;
  
  ObjCIvarDecl *ToIvar = ObjCIvarDecl::Create(Importer.getToContext(),
                                              cast<ObjCContainerDecl>(DC),
                                       Importer.Import(D->getInnerLocStart()),
                                              Loc, Name.getAsIdentifierInfo(),
                                              T, TInfo, D->getAccessControl(),
                                              BitWidth, D->getSynthesize(),
                                              D->getBackingIvarReferencedInAccessor());
  ImportAttributes(D, ToIvar);
  ToIvar->setLexicalDeclContext(LexicalDC);
  Importer.Imported(D, ToIvar);
  LexicalDC->addDeclInternal(ToIvar);
  return ToIvar;
  
}

bool ASTNodeImporter::ImportVarDeclInfo(VarDecl *From, VarDecl *To) {
  ImportAttributes(From, To);
  To->setConstexpr(From->isConstexpr());
  To->setCXXForRangeDecl(From->isCXXForRangeDecl());
  To->setExceptionVariable(From->isExceptionVariable());
  To->setARCPseudoStrong(From->isARCPseudoStrong());
  To->setImplicit(From->isImplicit());
  To->setInitCapture(From->isInitCapture());
  To->setInitStyle(From->getInitStyle());
  To->setNRVOVariable(From->isNRVOVariable());
  To->setTSCSpec(From->getTSCSpec());

  if (VarTemplateDecl *TemplD = From->getDescribedVarTemplate()) {
    VarTemplateDecl *ToTempl = cast_or_null<VarTemplateDecl>(
          Importer.Import(TemplD));
    assert(ToTempl);
    if (!ToTempl)
      return true;
    To->setDescribedVarTemplate(TemplD);
  } else if (MemberSpecializationInfo *MemberInfo =
             From->getMemberSpecializationInfo()) {
    TemplateSpecializationKind SK = MemberInfo->getTemplateSpecializationKind();
    VarDecl *VD = cast_or_null<VarDecl>(
          Importer.Import(From->getInstantiatedFromStaticDataMember()));
    assert(VD);
    if (!VD)
      return true;
    To->setInstantiationOfStaticDataMember(VD, SK);
    To->getMemberSpecializationInfo()->setPointOfInstantiation(
          Importer.Import(MemberInfo->getPointOfInstantiation()));
  }
  return false;
}

Decl *ASTNodeImporter::VisitVarDecl(VarDecl *D) {
  // Import the major distinguishing characteristics of a variable.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;
  
  // Try to find a variable in our own ("to") context with the same name and
  // in the same context as the variable we're importing.
  if (D->isFileVarDecl()) {
    VarDecl *MergeWithVar = 0;
    SmallVector<NamedDecl *, 4> ConflictingDecls;
    unsigned IDNS = Decl::IDNS_Ordinary;
    SmallVector<NamedDecl *, 2> FoundDecls;
    DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
    for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
      if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
        continue;
      
      if (VarDecl *FoundVar = dyn_cast<VarDecl>(FoundDecls[I])) {
        // We have found a variable that we may need to merge with. Check it.
        if (FoundVar->hasExternalFormalLinkage() &&
            D->hasExternalFormalLinkage()) {
          if (Importer.IsStructurallyEquivalent(D->getType(), 
                                                FoundVar->getType())) {
            MergeWithVar = FoundVar;
            break;
          }

          const ArrayType *FoundArray
            = Importer.getToContext().getAsArrayType(FoundVar->getType());
          const ArrayType *TArray
            = Importer.getToContext().getAsArrayType(D->getType());
          if (FoundArray && TArray) {
            if (isa<IncompleteArrayType>(FoundArray) &&
                (isa<ConstantArrayType>(TArray) ||
                 isa<DependentSizedArrayType>(TArray))) {
              // Import the type.
              QualType T = Importer.Import(D->getType());
              if (T.isNull())
                return 0;
              
              FoundVar->setType(T);
              MergeWithVar = FoundVar;
              break;
            } else if (isa<IncompleteArrayType>(TArray) &&
                       isa<ConstantArrayType>(FoundArray)) {
              MergeWithVar = FoundVar;
              break;
            }
          }

          Importer.ToDiag(Loc, diag::err_odr_variable_type_inconsistent)
            << Name << D->getType() << FoundVar->getType();
          Importer.ToDiag(FoundVar->getLocation(), diag::note_odr_value_here)
            << FoundVar->getType();

          // Try to merge a found variable without any guarantee it is good.
          // There were some cases where an external variable was declared
          // without a qualifier and declared with a qualifier.
          // Also throw a diagnostic as a warning for a programmer.
          if (Importer.IsStructurallyEquivalent(D->getType(),
                                                FoundVar->getType(),
                                                true, false)) {
            MergeWithVar = FoundVar;
            break;
          }

        }
      }
      
      ConflictingDecls.push_back(FoundDecls[I]);
    }

    if (MergeWithVar) {
      // An equivalent variable with external linkage has been found. Link 
      // the two declarations, then merge them.
      Importer.Imported(D, MergeWithVar);
      
      if (VarDecl *DDef = D->getDefinition()) {
        if (!MergeWithVar->getDefinition()) {

          Expr *Init = Importer.Import(DDef->getInit());
          MergeWithVar->setInit(Init);
          if (DDef->isInitKnownICE()) {
            EvaluatedStmt *Eval = MergeWithVar->ensureEvaluatedStmt();
            Eval->CheckedICE = true;
            Eval->IsICE = DDef->isInitICE();
          }
        }
      }
      
      return MergeWithVar;
    }
    
    if (!ConflictingDecls.empty()) {
      Name = Importer.HandleNameConflict(Name, DC, IDNS,
                                         ConflictingDecls.data(), 
                                         ConflictingDecls.size());
      if (!Name)
        return 0;
    }
  }
    
  // Import the type.
  QualType T = Importer.Import(D->getType());
  if (T.isNull())
    return 0;
  
  // Create the imported variable.
  TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
  VarDecl *ToVar = VarDecl::Create(Importer.getToContext(), DC,
                                   Importer.Import(D->getInnerLocStart()),
                                   Loc, Name.getAsIdentifierInfo(),
                                   T, TInfo,
                                   D->getStorageClass());
  ImportVarDeclInfo(D, ToVar);
  ToVar->setQualifierInfo(Importer.Import(D->getQualifierLoc()));
  ToVar->setAccess(D->getAccess());
  Importer.Imported(D, ToVar);

  ToVar->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(ToVar);

  // Merge the initializer.
  if (D->hasInit())
    if (ImportDefinition(D, ToVar))
      return 0;

  return ToVar;
}

Decl *ASTNodeImporter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
  // Parameters are created in the translation unit's context, then moved
  // into the function declaration's context afterward.
  DeclContext *DC = Importer.getToContext().getTranslationUnitDecl();
  
  // Import the name of this declaration.
  DeclarationName Name = Importer.Import(D->getDeclName());
  if (D->getDeclName() && !Name)
    return 0;
  
  // Import the location of this declaration.
  SourceLocation Loc = Importer.Import(D->getLocation());
  
  // Import the parameter's type.
  QualType T = Importer.Import(D->getType());
  if (T.isNull())
    return 0;
  
  // Create the imported parameter.
  ImplicitParamDecl *ToParm
    = ImplicitParamDecl::Create(Importer.getToContext(), DC,
                                Loc, Name.getAsIdentifierInfo(),
                                T);
  Importer.Imported(D, ToParm);

  ImportVarDeclInfo(D, ToParm);

  return ToParm;
}

Decl *ASTNodeImporter::VisitParmVarDecl(ParmVarDecl *D) {
  // Parameters are created in the translation unit's context, then moved
  // into the function declaration's context afterward.
  DeclContext *DC = Importer.getToContext().getTranslationUnitDecl();
  
  // Import the name of this declaration.
  DeclarationName Name = Importer.Import(D->getDeclName());
  if (D->getDeclName() && !Name)
    return 0;
  
  // Import the location of this declaration.
  SourceLocation Loc = Importer.Import(D->getLocation());
  
  // Import the parameter's type.
  QualType T = Importer.Import(D->getType());
  if (T.isNull())
    return 0;
  
  // Create the imported parameter.
  TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
  ParmVarDecl *ToParm = ParmVarDecl::Create(Importer.getToContext(), DC,
                                     Importer.Import(D->getInnerLocStart()),
                                            Loc, Name.getAsIdentifierInfo(),
                                            T, TInfo, D->getStorageClass(),
                                            /*FIXME: Default argument*/ 0);

  Importer.Imported(D, ToParm);

  ToParm->setHasInheritedDefaultArg(D->hasInheritedDefaultArg());
  ToParm->setKNRPromoted(D->isKNRPromoted());
  ImportVarDeclInfo(D, ToParm);


  if (D->hasUninstantiatedDefaultArg()) {
    Expr *UDArg = D->getUninstantiatedDefaultArg();
    Expr *ToUD = Importer.Import(UDArg);
    assert(ToUD);
    if (!ToUD)
      return NULL;
    ToParm->setUninstantiatedDefaultArg(D->getUninstantiatedDefaultArg());
  } else if (Expr *DefaultArg = D->getDefaultArg()) {
    Expr *ToDefaultArg = Importer.Import(DefaultArg);
    assert(ToDefaultArg);
    if (!ToDefaultArg)
      return NULL;
    ToParm->setDefaultArg(ToDefaultArg);
  }

  if (D->hasUnparsedDefaultArg())
    ToParm->setUnparsedDefaultArg();

  return ToParm;
}

Decl *ASTNodeImporter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
  // Import the major distinguishing characteristics of a method.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;
  
  SmallVector<NamedDecl *, 2> FoundDecls;
  DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
  for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
    if (ObjCMethodDecl *FoundMethod = dyn_cast<ObjCMethodDecl>(FoundDecls[I])) {
      if (FoundMethod->isInstanceMethod() != D->isInstanceMethod())
        continue;

      // Check return types.
      if (!Importer.IsStructurallyEquivalent(D->getResultType(),
                                             FoundMethod->getResultType())) {
        Importer.ToDiag(Loc, diag::err_odr_objc_method_result_type_inconsistent)
          << D->isInstanceMethod() << Name
          << D->getResultType() << FoundMethod->getResultType();
        Importer.ToDiag(FoundMethod->getLocation(), 
                        diag::note_odr_objc_method_here)
          << D->isInstanceMethod() << Name;
        return 0;
      }

      // Check the number of parameters.
      if (D->param_size() != FoundMethod->param_size()) {
        Importer.ToDiag(Loc, diag::err_odr_objc_method_num_params_inconsistent)
          << D->isInstanceMethod() << Name
          << D->param_size() << FoundMethod->param_size();
        Importer.ToDiag(FoundMethod->getLocation(), 
                        diag::note_odr_objc_method_here)
          << D->isInstanceMethod() << Name;
        return 0;
      }

      // Check parameter types.
      for (ObjCMethodDecl::param_iterator P = D->param_begin(), 
             PEnd = D->param_end(), FoundP = FoundMethod->param_begin();
           P != PEnd; ++P, ++FoundP) {
        if (!Importer.IsStructurallyEquivalent((*P)->getType(), 
                                               (*FoundP)->getType())) {
          Importer.FromDiag((*P)->getLocation(), 
                            diag::err_odr_objc_method_param_type_inconsistent)
            << D->isInstanceMethod() << Name
            << (*P)->getType() << (*FoundP)->getType();
          Importer.ToDiag((*FoundP)->getLocation(), diag::note_odr_value_here)
            << (*FoundP)->getType();
          return 0;
        }
      }

      // Check variadic/non-variadic.
      // Check the number of parameters.
      if (D->isVariadic() != FoundMethod->isVariadic()) {
        Importer.ToDiag(Loc, diag::err_odr_objc_method_variadic_inconsistent)
          << D->isInstanceMethod() << Name;
        Importer.ToDiag(FoundMethod->getLocation(), 
                        diag::note_odr_objc_method_here)
          << D->isInstanceMethod() << Name;
        return 0;
      }

      // FIXME: Any other bits we need to merge?
      return Importer.Imported(D, FoundMethod);
    }
  }

  // Import the result type.
  QualType ResultTy = Importer.Import(D->getResultType());
  if (ResultTy.isNull())
    return 0;

  TypeSourceInfo *ResultTInfo = Importer.Import(D->getResultTypeSourceInfo());

  ObjCMethodDecl *ToMethod
    = ObjCMethodDecl::Create(Importer.getToContext(),
                             Loc,
                             Importer.Import(D->getLocEnd()),
                             Name.getObjCSelector(),
                             ResultTy, ResultTInfo, DC,
                             D->isInstanceMethod(),
                             D->isVariadic(),
                             D->isPropertyAccessor(),
                             D->isImplicit(),
                             D->isDefined(),
                             D->getImplementationControl(),
                             D->hasRelatedResultType());

  // FIXME: When we decide to merge method definitions, we'll need to
  // deal with implicit parameters.

  // Import the parameters
  SmallVector<ParmVarDecl *, 5> ToParams;
  for (ObjCMethodDecl::param_iterator FromP = D->param_begin(),
                                   FromPEnd = D->param_end();
       FromP != FromPEnd; 
       ++FromP) {
    ParmVarDecl *ToP = cast_or_null<ParmVarDecl>(Importer.Import(*FromP));
    if (!ToP)
      return 0;
    
    ToParams.push_back(ToP);
  }
  
  // Set the parameters.
  for (unsigned I = 0, N = ToParams.size(); I != N; ++I)
    ToParams[I]->setOwningFunction(ToMethod);

  SmallVector<SourceLocation, 12> SelLocs;
  D->getSelectorLocs(SelLocs);
  for (int i = 0, e = SelLocs.size(); i < e; i++)
    SelLocs[i] = Importer.Import(SelLocs[i]);
  ToMethod->setMethodParams(Importer.getToContext(), ToParams, SelLocs);

  ImportAttributes(D, ToMethod);
  ToMethod->setLexicalDeclContext(LexicalDC);
  Importer.Imported(D, ToMethod);
  LexicalDC->addDeclInternal(ToMethod);
  return ToMethod;
}

Decl *ASTNodeImporter::VisitObjCCategoryDecl(ObjCCategoryDecl *D) {
  // Import the major distinguishing characteristics of a category.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;
  
  ObjCInterfaceDecl *ToInterface
    = cast_or_null<ObjCInterfaceDecl>(Importer.Import(D->getClassInterface()));
  if (!ToInterface)
    return 0;
  
  // Determine if we've already encountered this category.
  ObjCCategoryDecl *MergeWithCategory
    = ToInterface->FindCategoryDeclaration(Name.getAsIdentifierInfo());
  ObjCCategoryDecl *ToCategory = MergeWithCategory;
  if (!ToCategory) {
    ToCategory = ObjCCategoryDecl::Create(Importer.getToContext(), DC,
                                          Importer.Import(D->getAtStartLoc()),
                                          Loc, 
                                       Importer.Import(D->getCategoryNameLoc()), 
                                          Name.getAsIdentifierInfo(),
                                          ToInterface,
                                       Importer.Import(D->getIvarLBraceLoc()),
                                       Importer.Import(D->getIvarRBraceLoc()));
    ToCategory->setLexicalDeclContext(LexicalDC);
    LexicalDC->addDeclInternal(ToCategory);
    Importer.Imported(D, ToCategory);
    
    // Import protocols
    SmallVector<ObjCProtocolDecl *, 4> Protocols;
    SmallVector<SourceLocation, 4> ProtocolLocs;
    ObjCCategoryDecl::protocol_loc_iterator FromProtoLoc
      = D->protocol_loc_begin();
    for (ObjCCategoryDecl::protocol_iterator FromProto = D->protocol_begin(),
                                          FromProtoEnd = D->protocol_end();
         FromProto != FromProtoEnd;
         ++FromProto, ++FromProtoLoc) {
      ObjCProtocolDecl *ToProto
        = cast_or_null<ObjCProtocolDecl>(Importer.Import(*FromProto));
      if (!ToProto)
        return 0;
      Protocols.push_back(ToProto);
      ProtocolLocs.push_back(Importer.Import(*FromProtoLoc));
    }
    
    // FIXME: If we're merging, make sure that the protocol list is the same.
    ToCategory->setProtocolList(Protocols.data(), Protocols.size(),
                                ProtocolLocs.data(), Importer.getToContext());
    
  } else {
    Importer.Imported(D, ToCategory);
  }
  
  // Import all of the members of this category.
  ImportDeclContext(D);
 
  // If we have an implementation, import it as well.
  if (D->getImplementation()) {
    ObjCCategoryImplDecl *Impl
      = cast_or_null<ObjCCategoryImplDecl>(
                                       Importer.Import(D->getImplementation()));
    if (!Impl)
      return 0;
    
    ToCategory->setImplementation(Impl);
  }
  
  ImportAttributes(D, ToCategory);
  return ToCategory;
}

bool ASTNodeImporter::ImportDefinition(ObjCProtocolDecl *From, 
                                       ObjCProtocolDecl *To,
                                       ImportDefinitionKind Kind) {
  if (To->getDefinition()) {
    if (shouldForceImportDeclContext(Kind))
      ImportDeclContext(From);
    return false;
  }

  // Start the protocol definition
  To->startDefinition();
  
  // Import protocols
  SmallVector<ObjCProtocolDecl *, 4> Protocols;
  SmallVector<SourceLocation, 4> ProtocolLocs;
  ObjCProtocolDecl::protocol_loc_iterator 
  FromProtoLoc = From->protocol_loc_begin();
  for (ObjCProtocolDecl::protocol_iterator FromProto = From->protocol_begin(),
                                        FromProtoEnd = From->protocol_end();
       FromProto != FromProtoEnd;
       ++FromProto, ++FromProtoLoc) {
    ObjCProtocolDecl *ToProto
      = cast_or_null<ObjCProtocolDecl>(Importer.Import(*FromProto));
    if (!ToProto)
      return true;
    Protocols.push_back(ToProto);
    ProtocolLocs.push_back(Importer.Import(*FromProtoLoc));
  }
  
  // FIXME: If we're merging, make sure that the protocol list is the same.
  To->setProtocolList(Protocols.data(), Protocols.size(),
                      ProtocolLocs.data(), Importer.getToContext());

  if (shouldForceImportDeclContext(Kind)) {
    // Import all of the members of this protocol.
    ImportDeclContext(From, /*ForceImport=*/true);
  }
  return false;
}

Decl *ASTNodeImporter::VisitObjCProtocolDecl(ObjCProtocolDecl *D) {
  // If this protocol has a definition in the translation unit we're coming 
  // from, but this particular declaration is not that definition, import the
  // definition and map to that.
  ObjCProtocolDecl *Definition = D->getDefinition();
  if (Definition && Definition != D) {
    Decl *ImportedDef = Importer.Import(Definition);
    if (!ImportedDef)
      return 0;
    
    return Importer.Imported(D, ImportedDef);
  }

  // Import the major distinguishing characteristics of a protocol.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;

  ObjCProtocolDecl *MergeWithProtocol = 0;
  SmallVector<NamedDecl *, 2> FoundDecls;
  DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
  for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
    if (!FoundDecls[I]->isInIdentifierNamespace(Decl::IDNS_ObjCProtocol))
      continue;
    
    if ((MergeWithProtocol = dyn_cast<ObjCProtocolDecl>(FoundDecls[I])))
      break;
  }
  
  ObjCProtocolDecl *ToProto = MergeWithProtocol;
  if (!ToProto) {
    ToProto = ObjCProtocolDecl::Create(Importer.getToContext(), DC,
                                       Name.getAsIdentifierInfo(), Loc,
                                       Importer.Import(D->getAtStartLoc()),
                                       /*PrevDecl=*/0);

    Importer.Imported(D, ToProto);

    ToProto->setLexicalDeclContext(LexicalDC);
    LexicalDC->addDeclInternal(ToProto);
  }
    
  Importer.Imported(D, ToProto);

  if (D->isThisDeclarationADefinition() && ImportDefinition(D, ToProto))
    return 0;
  
  ImportAttributes(D, ToProto);

  return ToProto;
}

void ASTNodeImporter::ImportAttributes(Decl *From, Decl *To) {
  for (Decl::attr_iterator I = From->attr_begin(), E = From->attr_end(); I != E;
       ++I) {
    Attr *ToAttr = (*I)->clone(Importer.getToContext());
    ToAttr->setRange(Importer.Import((*I)->getRange()));
    To->addAttr(ToAttr);
  }
}

Decl *ASTNodeImporter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
  DeclContext *DC = Importer.ImportContext(D->getDeclContext());
  DeclContext *LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());

  SourceLocation ExternLoc = Importer.Import(D->getExternLoc());
  SourceLocation LangLoc = Importer.Import(D->getLocation());

  bool HasBraces = D->hasBraces();
 
  LinkageSpecDecl *ToLinkageSpec = LinkageSpecDecl::Create(Importer.getToContext(),
                                                           DC,
                                                           ExternLoc,
                                                           LangLoc,
                                                           D->getLanguage(),
                                                           HasBraces);

  if (HasBraces) {
    SourceLocation RBraceLoc = Importer.Import(D->getRBraceLoc());
    ToLinkageSpec->setRBraceLoc(RBraceLoc);
  }

  ToLinkageSpec->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(ToLinkageSpec);

  Importer.Imported(D, ToLinkageSpec);

  ImportAttributes(D, ToLinkageSpec);

  return ToLinkageSpec;
}

Decl *ASTNodeImporter::VisitUsingDecl(UsingDecl *D) {
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return NULL;

  DeclarationNameInfo NameInfo(Name, Importer.Import(D->getNameInfo().getLoc()));
  ImportDeclarationNameLoc(D->getNameInfo(), NameInfo);

  // Check if it is already imported after ImportDeclParts.
  // This may happen because UsingShadowDecl has a pointer to its UsingDecl
  if (Decl *Found = Importer.GetImported(D))
    return cast<UsingDecl>(Found);

  UsingDecl *ToD = UsingDecl::Create(Importer.getToContext(), DC,
                                     Importer.Import(D->getUsingLoc()),
                                     Importer.Import(D->getQualifierLoc()),
                                     NameInfo, D->hasTypename());
  ImportAttributes(D, ToD);
  ToD->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(ToD);
  Importer.Imported(D, ToD);

  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end();
       I != E; ++I) {
    UsingShadowDecl *SD = cast<UsingShadowDecl>(Importer.Import(*I));
    ToD->addShadowDecl(SD);
  }
  return ToD;
}

Decl *ASTNodeImporter::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc)) {
    assert(false);
    return NULL;
  }

  DeclContext *ToCA = Importer.ImportContext(D->getCommonAncestor());
  if (!ToCA) {
    assert(false);
    return NULL;
  }

  NamespaceDecl *ToNom = cast_or_null<NamespaceDecl>(
        Importer.Import(D->getNominatedNamespace()));
  if (!ToNom) {
    assert(ToNom);
    return NULL;
  }

  UsingDirectiveDecl *ToD = UsingDirectiveDecl::Create(
        Importer.getToContext(), DC, Importer.Import(D->getUsingLoc()),
        Importer.Import(D->getNamespaceKeyLocation()),
        Importer.Import(D->getQualifierLoc()),
        Importer.Import(D->getIdentLocation()), ToNom, ToCA);
  ToD->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(ToD);
  Importer.Imported(D, ToD);
  ImportAttributes(D, ToD);

  return ToD;
}

Decl *ASTNodeImporter::VisitUnresolvedUsingValueDecl(
    UnresolvedUsingValueDecl *D) {
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return NULL;

  DeclarationNameInfo NameInfo(Name, Importer.Import(D->getNameInfo().getLoc()));
  ImportDeclarationNameLoc(D->getNameInfo(), NameInfo);

  UnresolvedUsingValueDecl *ToD = UnresolvedUsingValueDecl::Create(
        Importer.getToContext(), DC, Importer.Import(D->getUsingLoc()),
        Importer.Import(D->getQualifierLoc()), NameInfo);

  Importer.Imported(D, ToD);
  ToD->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(ToD);
  ImportAttributes(D, ToD);

  return ToD;
}

Decl *ASTNodeImporter::VisitUnresolvedUsingTypenameDecl(
    UnresolvedUsingTypenameDecl *D) {
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return NULL;

  UnresolvedUsingTypenameDecl *ToD = UnresolvedUsingTypenameDecl::Create(
        Importer.getToContext(), DC, Importer.Import(D->getUsingLoc()),
        Importer.Import(D->getTypenameLoc()),
        Importer.Import(D->getQualifierLoc()), Loc, Name);

  Importer.Imported(D, ToD);
  ToD->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(ToD);
  ImportAttributes(D, ToD);

  return ToD;
}

Decl *ASTNodeImporter::VisitUsingShadowDecl(UsingShadowDecl *D) {
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return NULL;

  UsingShadowDecl *ToD = UsingShadowDecl::Create(
        Importer.getToContext(), DC, Loc,
        cast<UsingDecl>(Importer.Import(D->getUsingDecl())),
        cast_or_null<NamedDecl>(Importer.Import(D->getTargetDecl())));

  ImportAttributes(D, ToD);
  ToD->setAccess(D->getAccess());
  ToD->setLexicalDeclContext(LexicalDC);
  Importer.Imported(D, ToD);

  LexicalDC->addDeclInternal(ToD);

  return ToD;
}


bool ASTNodeImporter::ImportDefinition(ObjCInterfaceDecl *From, 
                                       ObjCInterfaceDecl *To,
                                       ImportDefinitionKind Kind) {
  if (To->getDefinition()) {
    // Check consistency of superclass.
    ObjCInterfaceDecl *FromSuper = From->getSuperClass();
    if (FromSuper) {
      FromSuper = cast_or_null<ObjCInterfaceDecl>(Importer.Import(FromSuper));
      if (!FromSuper)
        return true;
    }
    
    ObjCInterfaceDecl *ToSuper = To->getSuperClass();    
    if ((bool)FromSuper != (bool)ToSuper ||
        (FromSuper && !declaresSameEntity(FromSuper, ToSuper))) {
      Importer.ToDiag(To->getLocation(), 
                      diag::err_odr_objc_superclass_inconsistent)
        << To->getDeclName();
      if (ToSuper)
        Importer.ToDiag(To->getSuperClassLoc(), diag::note_odr_objc_superclass)
          << To->getSuperClass()->getDeclName();
      else
        Importer.ToDiag(To->getLocation(), 
                        diag::note_odr_objc_missing_superclass);
      if (From->getSuperClass())
        Importer.FromDiag(From->getSuperClassLoc(), 
                          diag::note_odr_objc_superclass)
        << From->getSuperClass()->getDeclName();
      else
        Importer.FromDiag(From->getLocation(), 
                          diag::note_odr_objc_missing_superclass);        
    }
    
    if (shouldForceImportDeclContext(Kind))
      ImportDeclContext(From);
    return false;
  }
  
  // Start the definition.
  To->startDefinition();
  
  // If this class has a superclass, import it.
  if (From->getSuperClass()) {
    ObjCInterfaceDecl *Super = cast_or_null<ObjCInterfaceDecl>(
                                 Importer.Import(From->getSuperClass()));
    if (!Super)
      return true;
    
    To->setSuperClass(Super);
    To->setSuperClassLoc(Importer.Import(From->getSuperClassLoc()));
  }
  
  // Import protocols
  SmallVector<ObjCProtocolDecl *, 4> Protocols;
  SmallVector<SourceLocation, 4> ProtocolLocs;
  ObjCInterfaceDecl::protocol_loc_iterator 
  FromProtoLoc = From->protocol_loc_begin();
  
  for (ObjCInterfaceDecl::protocol_iterator FromProto = From->protocol_begin(),
                                         FromProtoEnd = From->protocol_end();
       FromProto != FromProtoEnd;
       ++FromProto, ++FromProtoLoc) {
    ObjCProtocolDecl *ToProto
      = cast_or_null<ObjCProtocolDecl>(Importer.Import(*FromProto));
    if (!ToProto)
      return true;
    Protocols.push_back(ToProto);
    ProtocolLocs.push_back(Importer.Import(*FromProtoLoc));
  }
  
  // FIXME: If we're merging, make sure that the protocol list is the same.
  To->setProtocolList(Protocols.data(), Protocols.size(),
                      ProtocolLocs.data(), Importer.getToContext());
  
  // Import categories. When the categories themselves are imported, they'll
  // hook themselves into this interface.
  for (ObjCInterfaceDecl::known_categories_iterator
         Cat = From->known_categories_begin(),
         CatEnd = From->known_categories_end();
       Cat != CatEnd; ++Cat) {
    Importer.Import(*Cat);
  }
  
  // If we have an @implementation, import it as well.
  if (From->getImplementation()) {
    ObjCImplementationDecl *Impl = cast_or_null<ObjCImplementationDecl>(
                                     Importer.Import(From->getImplementation()));
    if (!Impl)
      return true;
    
    To->setImplementation(Impl);
  }

  if (shouldForceImportDeclContext(Kind)) {
    // Import all of the members of this class.
    ImportDeclContext(From, /*ForceImport=*/true);
  }
  return false;
}

Decl *ASTNodeImporter::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
  // If this class has a definition in the translation unit we're coming from,
  // but this particular declaration is not that definition, import the
  // definition and map to that.
  ObjCInterfaceDecl *Definition = D->getDefinition();
  if (Definition && Definition != D) {
    Decl *ImportedDef = Importer.Import(Definition);
    if (!ImportedDef)
      return 0;
    
    return Importer.Imported(D, ImportedDef);
  }

  // Import the major distinguishing characteristics of an @interface.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;

  // Look for an existing interface with the same name.
  ObjCInterfaceDecl *MergeWithIface = 0;
  SmallVector<NamedDecl *, 2> FoundDecls;
  DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
  for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
    if (!FoundDecls[I]->isInIdentifierNamespace(Decl::IDNS_Ordinary))
      continue;
    
    if ((MergeWithIface = dyn_cast<ObjCInterfaceDecl>(FoundDecls[I])))
      break;
  }
  
  // Create an interface declaration, if one does not already exist.
  ObjCInterfaceDecl *ToIface = MergeWithIface;
  if (!ToIface) {
    ToIface = ObjCInterfaceDecl::Create(Importer.getToContext(), DC,
                                        Importer.Import(D->getAtStartLoc()),
                                        Name.getAsIdentifierInfo(), 
                                        /*PrevDecl=*/0,Loc,
                                        D->isImplicitInterfaceDecl());
    Importer.Imported(D, ToIface);

    ToIface->setLexicalDeclContext(LexicalDC);
    LexicalDC->addDeclInternal(ToIface);
  }
  Importer.Imported(D, ToIface);
  
  if (D->isThisDeclarationADefinition() && ImportDefinition(D, ToIface))
    return 0;
    
  ImportAttributes(D, ToIface);
  return ToIface;
}

Decl *ASTNodeImporter::VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D) {
  ObjCCategoryDecl *Category = cast_or_null<ObjCCategoryDecl>(
                                        Importer.Import(D->getCategoryDecl()));
  if (!Category)
    return 0;
  
  ObjCCategoryImplDecl *ToImpl = Category->getImplementation();
  if (!ToImpl) {
    DeclContext *DC = Importer.ImportContext(D->getDeclContext());
    if (!DC)
      return 0;
    
    SourceLocation CategoryNameLoc = Importer.Import(D->getCategoryNameLoc());
    ToImpl = ObjCCategoryImplDecl::Create(Importer.getToContext(), DC,
                                          Importer.Import(D->getIdentifier()),
                                          Category->getClassInterface(),
                                          Importer.Import(D->getLocation()),
                                          Importer.Import(D->getAtStartLoc()),
                                          CategoryNameLoc);
    
    DeclContext *LexicalDC = DC;
    if (D->getDeclContext() != D->getLexicalDeclContext()) {
      LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
      if (!LexicalDC)
        return 0;
      
      ToImpl->setLexicalDeclContext(LexicalDC);
    }
    
    LexicalDC->addDeclInternal(ToImpl);
    Category->setImplementation(ToImpl);
  }
  
  Importer.Imported(D, ToImpl);
  ImportDeclContext(D);
  ImportAttributes(D, ToImpl);
  return ToImpl;
}

Decl *ASTNodeImporter::VisitObjCImplementationDecl(ObjCImplementationDecl *D) {
  // Find the corresponding interface.
  ObjCInterfaceDecl *Iface = cast_or_null<ObjCInterfaceDecl>(
                                       Importer.Import(D->getClassInterface()));
  if (!Iface)
    return 0;

  // Import the superclass, if any.
  ObjCInterfaceDecl *Super = 0;
  if (D->getSuperClass()) {
    Super = cast_or_null<ObjCInterfaceDecl>(
                                          Importer.Import(D->getSuperClass()));
    if (!Super)
      return 0;
  }

  ObjCImplementationDecl *Impl = Iface->getImplementation();
  if (!Impl) {
    // We haven't imported an implementation yet. Create a new @implementation
    // now.
    Impl = ObjCImplementationDecl::Create(Importer.getToContext(),
                                  Importer.ImportContext(D->getDeclContext()),
                                          Iface, Super,
                                          Importer.Import(D->getLocation()),
                                          Importer.Import(D->getAtStartLoc()),
                                          Importer.Import(D->getSuperClassLoc()),
                                          Importer.Import(D->getIvarLBraceLoc()),
                                          Importer.Import(D->getIvarRBraceLoc()));
    
    if (D->getDeclContext() != D->getLexicalDeclContext()) {
      DeclContext *LexicalDC
        = Importer.ImportContext(D->getLexicalDeclContext());
      if (!LexicalDC)
        return 0;
      Impl->setLexicalDeclContext(LexicalDC);
    }
    
    // Associate the implementation with the class it implements.
    Iface->setImplementation(Impl);
    Importer.Imported(D, Iface->getImplementation());
  } else {
    Importer.Imported(D, Iface->getImplementation());

    // Verify that the existing @implementation has the same superclass.
    if ((Super && !Impl->getSuperClass()) ||
        (!Super && Impl->getSuperClass()) ||
        (Super && Impl->getSuperClass() && 
         !declaresSameEntity(Super->getCanonicalDecl(), Impl->getSuperClass()))) {
        Importer.ToDiag(Impl->getLocation(), 
                        diag::err_odr_objc_superclass_inconsistent)
          << Iface->getDeclName();
        // FIXME: It would be nice to have the location of the superclass
        // below.
        if (Impl->getSuperClass())
          Importer.ToDiag(Impl->getLocation(), 
                          diag::note_odr_objc_superclass)
          << Impl->getSuperClass()->getDeclName();
        else
          Importer.ToDiag(Impl->getLocation(), 
                          diag::note_odr_objc_missing_superclass);
        if (D->getSuperClass())
          Importer.FromDiag(D->getLocation(), 
                            diag::note_odr_objc_superclass)
          << D->getSuperClass()->getDeclName();
        else
          Importer.FromDiag(D->getLocation(), 
                            diag::note_odr_objc_missing_superclass);
      return 0;
    }
  }
    
  // Import all of the members of this @implementation.
  ImportDeclContext(D);
  ImportAttributes(D, Impl);

  return Impl;
}

Decl *ASTNodeImporter::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
  // Import the major distinguishing characteristics of an @property.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;

  // Check whether we have already imported this property.
  SmallVector<NamedDecl *, 2> FoundDecls;
  DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
  for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
    if (ObjCPropertyDecl *FoundProp
                                = dyn_cast<ObjCPropertyDecl>(FoundDecls[I])) {
      // Check property types.
      if (!Importer.IsStructurallyEquivalent(D->getType(), 
                                             FoundProp->getType())) {
        Importer.ToDiag(Loc, diag::err_odr_objc_property_type_inconsistent)
          << Name << D->getType() << FoundProp->getType();
        Importer.ToDiag(FoundProp->getLocation(), diag::note_odr_value_here)
          << FoundProp->getType();
        return 0;
      }

      // FIXME: Check property attributes, getters, setters, etc.?

      // Consider these properties to be equivalent.
      Importer.Imported(D, FoundProp);
      return FoundProp;
    }
  }

  // Import the type.
  TypeSourceInfo *T = Importer.Import(D->getTypeSourceInfo());
  if (!T)
    return 0;

  // Create the new property.
  ObjCPropertyDecl *ToProperty
    = ObjCPropertyDecl::Create(Importer.getToContext(), DC, Loc,
                               Name.getAsIdentifierInfo(), 
                               Importer.Import(D->getAtLoc()),
                               Importer.Import(D->getLParenLoc()),
                               T,
                               D->getPropertyImplementation());
  Importer.Imported(D, ToProperty);
  ImportAttributes(D, ToProperty);
  ToProperty->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(ToProperty);

  ToProperty->setPropertyAttributes(D->getPropertyAttributes());
  ToProperty->setPropertyAttributesAsWritten(
                                      D->getPropertyAttributesAsWritten());
  ToProperty->setGetterName(Importer.Import(D->getGetterName()));
  ToProperty->setSetterName(Importer.Import(D->getSetterName()));
  ToProperty->setGetterMethodDecl(
     cast_or_null<ObjCMethodDecl>(Importer.Import(D->getGetterMethodDecl())));
  ToProperty->setSetterMethodDecl(
     cast_or_null<ObjCMethodDecl>(Importer.Import(D->getSetterMethodDecl())));
  ToProperty->setPropertyIvarDecl(
       cast_or_null<ObjCIvarDecl>(Importer.Import(D->getPropertyIvarDecl())));
  return ToProperty;
}

Decl *ASTNodeImporter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
  ObjCPropertyDecl *Property = cast_or_null<ObjCPropertyDecl>(
                                        Importer.Import(D->getPropertyDecl()));
  if (!Property)
    return 0;

  DeclContext *DC = Importer.ImportContext(D->getDeclContext());
  if (!DC)
    return 0;
  
  // Import the lexical declaration context.
  DeclContext *LexicalDC = DC;
  if (D->getDeclContext() != D->getLexicalDeclContext()) {
    LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
    if (!LexicalDC)
      return 0;
  }

  ObjCImplDecl *InImpl = dyn_cast<ObjCImplDecl>(LexicalDC);
  if (!InImpl)
    return 0;

  // Import the ivar (for an @synthesize).
  ObjCIvarDecl *Ivar = 0;
  if (D->getPropertyIvarDecl()) {
    Ivar = cast_or_null<ObjCIvarDecl>(
                                    Importer.Import(D->getPropertyIvarDecl()));
    if (!Ivar)
      return 0;
  }

  ObjCPropertyImplDecl *ToImpl
    = InImpl->FindPropertyImplDecl(Property->getIdentifier());
  if (!ToImpl) {    
    ToImpl = ObjCPropertyImplDecl::Create(Importer.getToContext(), DC,
                                          Importer.Import(D->getLocStart()),
                                          Importer.Import(D->getLocation()),
                                          Property,
                                          D->getPropertyImplementation(),
                                          Ivar, 
                                  Importer.Import(D->getPropertyIvarDeclLoc()));
    ToImpl->setLexicalDeclContext(LexicalDC);
    Importer.Imported(D, ToImpl);
    LexicalDC->addDeclInternal(ToImpl);
  } else {
    // Check that we have the same kind of property implementation (@synthesize
    // vs. @dynamic).
    if (D->getPropertyImplementation() != ToImpl->getPropertyImplementation()) {
      Importer.ToDiag(ToImpl->getLocation(), 
                      diag::err_odr_objc_property_impl_kind_inconsistent)
        << Property->getDeclName() 
        << (ToImpl->getPropertyImplementation() 
                                              == ObjCPropertyImplDecl::Dynamic);
      Importer.FromDiag(D->getLocation(),
                        diag::note_odr_objc_property_impl_kind)
        << D->getPropertyDecl()->getDeclName()
        << (D->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic);
      return 0;
    }
    
    // For @synthesize, check that we have the same 
    if (D->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize &&
        Ivar != ToImpl->getPropertyIvarDecl()) {
      Importer.ToDiag(ToImpl->getPropertyIvarDeclLoc(), 
                      diag::err_odr_objc_synthesize_ivar_inconsistent)
        << Property->getDeclName()
        << ToImpl->getPropertyIvarDecl()->getDeclName()
        << Ivar->getDeclName();
      Importer.FromDiag(D->getPropertyIvarDeclLoc(), 
                        diag::note_odr_objc_synthesize_ivar_here)
        << D->getPropertyIvarDecl()->getDeclName();
      return 0;
    }
    
    // Merge the existing implementation with the new implementation.
    Importer.Imported(D, ToImpl);
  }
  ImportAttributes(D, ToImpl);

  return ToImpl;
}

Decl *ASTNodeImporter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
  // For template arguments, we adopt the translation unit as our declaration
  // context. This context will be fixed when the actual template declaration
  // is created.
  
  // FIXME: Import default argument.
  TemplateTypeParmDecl *ToD = TemplateTypeParmDecl::Create(
        Importer.getToContext(),
        Importer.getToContext().getTranslationUnitDecl(),
        Importer.Import(D->getLocStart()),
        Importer.Import(D->getLocation()),
        D->getDepth(),
        D->getIndex(),
        Importer.Import(D->getIdentifier()),
        D->wasDeclaredWithTypename(),
        D->isParameterPack());

  ImportAttributes(D, ToD);
  return ToD;
}

Decl *
ASTNodeImporter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
  // Import the name of this declaration.
  DeclarationName Name = Importer.Import(D->getDeclName());
  if (D->getDeclName() && !Name)
    return 0;
  
  // Import the location of this declaration.
  SourceLocation Loc = Importer.Import(D->getLocation());

  // Import the type of this declaration.
  QualType T = Importer.Import(D->getType());
  if (T.isNull())
    return 0;
  
  // Import type-source information.
  TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
  if (D->getTypeSourceInfo() && !TInfo)
    return 0;
  
  // FIXME: Import default argument.
  
  NonTypeTemplateParmDecl *ToD = NonTypeTemplateParmDecl::Create(
        Importer.getToContext(),
        Importer.getToContext().getTranslationUnitDecl(),
        Importer.Import(D->getInnerLocStart()),
        Loc, D->getDepth(), D->getPosition(),
        Name.getAsIdentifierInfo(),
        T, D->isParameterPack(), TInfo);

  ImportAttributes(D, ToD);
  return ToD;
}

Decl *
ASTNodeImporter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
  // Import the name of this declaration.
  DeclarationName Name = Importer.Import(D->getDeclName());
  if (D->getDeclName() && !Name)
    return 0;
  
  // Import the location of this declaration.
  SourceLocation Loc = Importer.Import(D->getLocation());
  
  // Import template parameters.
  TemplateParameterList *TemplateParams
    = ImportTemplateParameterList(D->getTemplateParameters());
  if (!TemplateParams)
    return 0;
  
  // FIXME: Import default argument.
  
  TemplateTemplateParmDecl *ToD = TemplateTemplateParmDecl::Create(
        Importer.getToContext(),
        Importer.getToContext().getTranslationUnitDecl(),
        Loc, D->getDepth(), D->getPosition(),
        D->isParameterPack(),
        Name.getAsIdentifierInfo(),
        TemplateParams);

  ImportAttributes(D, ToD);
  return ToD;
}

Decl *ASTNodeImporter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
  // If this record has a definition in the translation unit we're coming from,
  // but this particular declaration is not that definition, import the
  // definition and map to that.
  CXXRecordDecl *Definition
    = cast_or_null<CXXRecordDecl>(D->getTemplatedDecl()->getDefinition());
  if (Definition && Definition != D->getTemplatedDecl()) {
    Decl *ImportedDef
      = Importer.Import(Definition->getDescribedClassTemplate());
    if (!ImportedDef)
      return 0;

    return Importer.Imported(D, ImportedDef);
  }

  // Import the major distinguishing characteristics of this class template.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;

  if (Decl *Imp = Importer.GetImported(D))
    return Imp;
  
  // We may already have a template of the same name; try to find and match it.
  if (!DC->isFunctionOrMethod()) {
    SmallVector<NamedDecl *, 4> ConflictingDecls;
    SmallVector<NamedDecl *, 2> FoundDecls;
    DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
    for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
      if (!FoundDecls[I]->isInIdentifierNamespace(Decl::IDNS_Ordinary))
        continue;
      
      Decl *Found = FoundDecls[I];
      if (ClassTemplateDecl *FoundTemplate 
                                        = dyn_cast<ClassTemplateDecl>(Found)) {
        if (IsStructuralMatch(D, FoundTemplate, false)) {
          // The class templates structurally match; call it the same template.
          // FIXME: We may be filling in a forward declaration here. Handle
          // this case!
          Importer.Imported(D->getTemplatedDecl(), 
                            FoundTemplate->getTemplatedDecl());
          return Importer.Imported(D, FoundTemplate);
        }         
      }
      
      ConflictingDecls.push_back(FoundDecls[I]);
    }
    
    if (!ConflictingDecls.empty()) {
      Name = Importer.HandleNameConflict(Name, DC, Decl::IDNS_Ordinary,
                                         ConflictingDecls.data(), 
                                         ConflictingDecls.size());
      if (!Name)
        return 0;
    }
  }

  CXXRecordDecl *DTemplated = D->getTemplatedDecl();
  
  // Create the declaration that is being templated.
  CXXRecordDecl *D2Templated = cast_or_null<CXXRecordDecl>(
        Importer.Import(DTemplated));
  assert(D2Templated);
  if (!D2Templated)
    return NULL;

  if (Decl *Imp = Importer.GetImported(D))
    return Imp;
  
  // Create the class template declaration itself.
  TemplateParameterList *TemplateParams
    = ImportTemplateParameterList(D->getTemplateParameters());
  if (!TemplateParams)
    return 0;
  
  ClassTemplateDecl *D2 = ClassTemplateDecl::Create(Importer.getToContext(), DC, 
                                                    Loc, Name, TemplateParams, 
                                                    D2Templated, 
  /*PrevDecl=*/0);
  D2Templated->setDescribedClassTemplate(D2);    
  
  D2->setAccess(D->getAccess());
  D2->setLexicalDeclContext(LexicalDC);

  // Note the relationship between the class templates.
  Importer.Imported(D, D2);

  LexicalDC->addDeclInternal(D2);

  if (DTemplated->isCompleteDefinition() &&
      !D2Templated->isCompleteDefinition()) {
    // FIXME: Import definition!
  }
  
  ImportAttributes(D, D2);

  return D2;
}

Decl *ASTNodeImporter::VisitClassTemplateSpecializationDecl(
                                          ClassTemplateSpecializationDecl *D) {
  // If this record has a definition in the translation unit we're coming from,
  // but this particular declaration is not that definition, import the
  // definition and map to that.
  TagDecl *Definition = D->getDefinition();
  if (Definition && Definition != D) {
    Decl *ImportedDef = Importer.Import(Definition);
    if (!ImportedDef)
      return 0;
    
    return Importer.Imported(D, ImportedDef);
  }

  ClassTemplateDecl *ClassTemplate
    = cast_or_null<ClassTemplateDecl>(Importer.Import(
                                                 D->getSpecializedTemplate()));
  if (!ClassTemplate) {
    assert(false);
    return 0;
  }
  
  // Import the context of this declaration.
  DeclContext *DC = ClassTemplate->getDeclContext();
  assert(DC);
  if (!DC)
    return 0;
  
  DeclContext *LexicalDC = DC;
  if (D->getDeclContext() != D->getLexicalDeclContext()) {
    LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
    assert(LexicalDC);
    if (!LexicalDC)
      return 0;
  }
  
  // Import the location of this declaration.
  SourceLocation StartLoc = Importer.Import(D->getLocStart());
  SourceLocation IdLoc = Importer.Import(D->getLocation());

  // Import template arguments.
  SmallVector<TemplateArgument, 2> TemplateArgs;
  if (ImportTemplateArguments(D->getTemplateArgs().data(), 
                              D->getTemplateArgs().size(),
                              TemplateArgs))
    return 0;
  
  // Try to find an existing specialization with these template arguments.
  void *InsertPos = 0;
  ClassTemplateSpecializationDecl *D2
    = ClassTemplate->findSpecialization(TemplateArgs.data(), 
                                        TemplateArgs.size(), InsertPos);
  if (D2) {
    // We already have a class template specialization with these template
    // arguments.
    
    // FIXME: Check for specialization vs. instantiation errors.
    
    if (RecordDecl *FoundDef = D2->getDefinition()) {
      if (!D->isCompleteDefinition() || IsStructuralMatch(D, FoundDef, false)) {
        // The record types structurally match, or the "from" translation
        // unit only had a forward declaration anyway; call it the same
        // function.
        if (CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(FoundDef))
          if (!CRD->isDependentType() && CRD->needsImplicitDestructor() &&
              !CRD->getDestructor())
            Importer.getToSema()->DeclareImplicitDestructor(CRD);
        return Importer.Imported(D, FoundDef);
      }
    }
  } else {
    // Create a new specialization.
    if (ClassTemplatePartialSpecializationDecl *PartialSpec =
        dyn_cast<ClassTemplatePartialSpecializationDecl>(D)) {
      // Import TemplateArgumentListInfo
      TemplateArgumentListInfo FromTAInfo, ToTAInfo;
      PartialSpec->getTemplateArgsAsWritten()->copyInto(FromTAInfo);
      for (unsigned i = 0, e = FromTAInfo.size(); i < e; i++) {
        const TemplateArgumentLoc &FromLoc = FromTAInfo[i];
        ToTAInfo.addArgument(ImportTemplateArgumentLoc(FromLoc));
      }

      QualType CanonInjType = Importer.Import(
            PartialSpec->getInjectedSpecializationType());
      if (CanonInjType.isNull()) {
        assert(CanonInjType.isNull());
        return NULL;
      }
      CanonInjType = CanonInjType.getCanonicalType();

      TemplateParameterList *ToTPList = ImportTemplateParameterList(
            PartialSpec->getTemplateParameters());
      assert(ToTPList || !PartialSpec->getTemplateParameters());
      if (!ToTPList && PartialSpec->getTemplateParameters())
        return NULL;

      D2 = ClassTemplatePartialSpecializationDecl::Create(
            Importer.getToContext(), D->getTagKind(), DC, StartLoc, IdLoc,
            ToTPList, ClassTemplate, TemplateArgs.data(), TemplateArgs.size(),
            ToTAInfo, CanonInjType, NULL);
    } else {
      D2 = ClassTemplateSpecializationDecl::Create(Importer.getToContext(),
                                                   D->getTagKind(), DC,
                                                   StartLoc, IdLoc,
                                                   ClassTemplate,
                                                   TemplateArgs.data(),
                                                   TemplateArgs.size(),
                                                   /*PrevDecl=*/0);
    }
    D2->setSpecializationKind(D->getSpecializationKind());

    // Add this specialization to the class template.
    ClassTemplate->AddSpecialization(D2, InsertPos);
    
    // Import the qualifier, if any.
    D2->setQualifierInfo(Importer.Import(D->getQualifierLoc()));
    
    ImportAttributes(D, D2);
    Importer.Imported(D, D2);

    if (D->getTypeAsWritten()) {
      TypeSourceInfo *TInfo = Importer.Import(D->getTypeAsWritten());
      assert(TInfo);
      if (!TInfo)
        return NULL;
      D2->setTypeAsWritten(TInfo);
      D2->setTemplateKeywordLoc(Importer.Import(D->getTemplateKeywordLoc()));
      D2->setExternLoc(Importer.Import(D->getExternLoc()));
    }

    SourceLocation POI = Importer.Import(D->getPointOfInstantiation());
    assert(POI.isValid() || D->getPointOfInstantiation().isInvalid());
    if (POI.isValid())
      D2->setPointOfInstantiation(POI);
    D2->setTemplateSpecializationKind(D->getTemplateSpecializationKind());

    // Add the specialization to this context.
    D2->setLexicalDeclContext(LexicalDC);
    LexicalDC->addDeclInternal(D2);
  }
  Importer.Imported(D, D2);
  
  if (D->isCompleteDefinition() && ImportDefinition(D, D2))
    return 0;
  
  return D2;
}

Decl *ASTNodeImporter::VisitVarTemplateDecl(VarTemplateDecl *D) {
  // If this variable has a definition in the translation unit we're coming
  // from,
  // but this particular declaration is not that definition, import the
  // definition and map to that.
  VarDecl *Definition =
      cast_or_null<VarDecl>(D->getTemplatedDecl()->getDefinition());
  if (Definition && Definition != D->getTemplatedDecl()) {
    Decl *ImportedDef = Importer.Import(Definition->getDescribedVarTemplate());
    if (!ImportedDef)
      return 0;

    return Importer.Imported(D, ImportedDef);
  }

  // Import the major distinguishing characteristics of this variable template.
  DeclContext *DC, *LexicalDC;
  DeclarationName Name;
  SourceLocation Loc;
  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
    return 0;

  // We may already have a template of the same name; try to find and match it.
  assert(!DC->isFunctionOrMethod() &&
         "Variable templates cannot be declared at function scope");
  SmallVector<NamedDecl *, 4> ConflictingDecls;
  SmallVector<NamedDecl *, 2> FoundDecls;
  DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
  for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
    if (!FoundDecls[I]->isInIdentifierNamespace(Decl::IDNS_Ordinary))
      continue;

    Decl *Found = FoundDecls[I];
    if (VarTemplateDecl *FoundTemplate = dyn_cast<VarTemplateDecl>(Found)) {
      if (IsStructuralMatch(D, FoundTemplate)) {
        // The variable templates structurally match; call it the same template.
        Importer.Imported(D->getTemplatedDecl(),
                          FoundTemplate->getTemplatedDecl());
        return Importer.Imported(D, FoundTemplate);
      }
    }

    ConflictingDecls.push_back(FoundDecls[I]);
  }

  if (!ConflictingDecls.empty()) {
    Name = Importer.HandleNameConflict(Name, DC, Decl::IDNS_Ordinary,
                                       ConflictingDecls.data(),
                                       ConflictingDecls.size());
    if (!Name)
      return 0;
  }


  VarDecl *DTemplated = D->getTemplatedDecl();

  // Import the type.
  QualType T = Importer.Import(DTemplated->getType());
  if (T.isNull())
    return 0;

  // Create the declaration that is being templated.
  VarDecl *D2Templated = cast_or_null<VarDecl>(
        Importer.Import(D->getTemplatedDecl()));
  assert(D2Templated);
  if (!D2Templated)
    return NULL;

  // Merge the initializer.
  if (ImportDefinition(DTemplated, D2Templated))
    return 0;

  // Create the variable template declaration itself.
  TemplateParameterList *TemplateParams =
      ImportTemplateParameterList(D->getTemplateParameters());
  if (!TemplateParams)
    return 0;

  VarTemplateDecl *D2 = VarTemplateDecl::Create(
      Importer.getToContext(), DC, Loc, Name, TemplateParams, D2Templated,
      /*PrevDecl=*/0);
  D2Templated->setDescribedVarTemplate(D2);

  D2->setAccess(D->getAccess());

  // Note the relationship between the variable templates.
  Importer.Imported(D, D2);

  D2->setLexicalDeclContext(LexicalDC);
  LexicalDC->addDeclInternal(D2);

  if (DTemplated->isThisDeclarationADefinition() &&
      !D2Templated->isThisDeclarationADefinition()) {
    // FIXME: Import definition!
  }

  ImportAttributes(D, D2);

  return D2;
}

Decl *ASTNodeImporter::VisitVarTemplateSpecializationDecl(
    VarTemplateSpecializationDecl *D) {
  // If this record has a definition in the translation unit we're coming from,
  // but this particular declaration is not that definition, import the
  // definition and map to that.
  VarDecl *Definition = D->getDefinition();
  if (Definition && Definition != D) {
    Decl *ImportedDef = Importer.Import(Definition);
    if (!ImportedDef)
      return 0;

    return Importer.Imported(D, ImportedDef);
  }

  VarTemplateDecl *VarTemplate = cast_or_null<VarTemplateDecl>(
      Importer.Import(D->getSpecializedTemplate()));
  if (!VarTemplate)
    return 0;

  // Import the context of this declaration.
  DeclContext *DC = VarTemplate->getDeclContext();
  if (!DC)
    return 0;

  DeclContext *LexicalDC = DC;
  if (D->getDeclContext() != D->getLexicalDeclContext()) {
    LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
    if (!LexicalDC)
      return 0;
  }

  // Import the location of this declaration.
  SourceLocation StartLoc = Importer.Import(D->getLocStart());
  SourceLocation IdLoc = Importer.Import(D->getLocation());

  // Import template arguments.
  SmallVector<TemplateArgument, 2> TemplateArgs;
  if (ImportTemplateArguments(D->getTemplateArgs().data(),
                              D->getTemplateArgs().size(), TemplateArgs))
    return 0;

  // Try to find an existing specialization with these template arguments.
  void *InsertPos = 0;
  VarTemplateSpecializationDecl *D2 = VarTemplate->findSpecialization(
      TemplateArgs.data(), TemplateArgs.size(), InsertPos);
  if (D2) {
    // We already have a variable template specialization with these template
    // arguments.

    // FIXME: Check for specialization vs. instantiation errors.

    if (VarDecl *FoundDef = D2->getDefinition()) {
      if (!D->isThisDeclarationADefinition() ||
          IsStructuralMatch(D, FoundDef)) {
        // The record types structurally match, or the "from" translation
        // unit only had a forward declaration anyway; call it the same
        // variable.
        return Importer.Imported(D, FoundDef);
      }
    }
  } else {

    // Import the type.
    QualType T = Importer.Import(D->getType());
    if (T.isNull())
      return 0;
    TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());

    // Create a new specialization.
    if (VarTemplatePartialSpecializationDecl *PartialSpec =
        dyn_cast<VarTemplatePartialSpecializationDecl>(D)) {
      // Import TemplateArgumentListInfo
      TemplateArgumentListInfo FromTAInfo, ToTAInfo;
      PartialSpec->getTemplateArgsAsWritten()->copyInto(FromTAInfo);
      for (unsigned i = 0, e = FromTAInfo.size(); i < e; i++) {
        const TemplateArgumentLoc &FromLoc = FromTAInfo[i];
        ToTAInfo.addArgument(ImportTemplateArgumentLoc(FromLoc));
      }

      TemplateParameterList *ToTPList = ImportTemplateParameterList(
            PartialSpec->getTemplateParameters());
      assert(ToTPList || !PartialSpec->getTemplateParameters());
      if (!ToTPList && PartialSpec->getTemplateParameters())
        return NULL;

      D2 = VarTemplatePartialSpecializationDecl::Create(
            Importer.getToContext(), DC, StartLoc, IdLoc,
            ToTPList, VarTemplate, T, TInfo, D->getStorageClass(),
            TemplateArgs.data(), TemplateArgs.size(), ToTAInfo);
    } else {
      D2 = VarTemplateSpecializationDecl::Create(
          Importer.getToContext(), DC, StartLoc, IdLoc, VarTemplate, T, TInfo,
          D->getStorageClass(), TemplateArgs.data(), TemplateArgs.size());
    }

    D2->setPointOfInstantiation(Importer.Import(D->getPointOfInstantiation()));
    D2->setSpecializationKind(D->getSpecializationKind());

    const TemplateArgumentListInfo &FromTAInfo = D->getTemplateArgsInfo();
    TemplateArgumentListInfo ToTAInfo(
          Importer.Import(FromTAInfo.getLAngleLoc()),
          Importer.Import(FromTAInfo.getRAngleLoc()));
    for (unsigned i = 0, e = FromTAInfo.size(); i < e; i++) {
      const TemplateArgumentLoc &FromLoc = FromTAInfo[i];
      ToTAInfo.addArgument(ImportTemplateArgumentLoc(FromLoc));
    }
    D2->setTemplateArgsInfo(ToTAInfo);

    // Add this specialization to the class template.
    VarTemplate->AddSpecialization(D2, InsertPos);

    // Import the qualifier, if any.
    D2->setQualifierInfo(Importer.Import(D->getQualifierLoc()));

    Importer.Imported(D, D2);

    // Add the specialization to this context.
    D2->setLexicalDeclContext(LexicalDC);
    LexicalDC->addDeclInternal(D2);
  }
  Importer.Imported(D, D2);

  if (D->isThisDeclarationADefinition() && ImportDefinition(D, D2))
    return 0;

  ImportAttributes(D, D2);

  return D2;
}

//----------------------------------------------------------------------------
// Import Statements
//----------------------------------------------------------------------------

Stmt *ASTNodeImporter::VisitStmt(Stmt *S) {
  Importer.FromDiag(S->getLocStart(), diag::err_unsupported_ast_node)
    << S->getStmtClassName();
  return 0;
}

//----------------------------------------------------------------------------
// Import Expressions
//----------------------------------------------------------------------------
Expr *ASTNodeImporter::VisitExpr(Expr *E) {
  Importer.FromDiag(E->getLocStart(), diag::err_unsupported_ast_node)
    << E->getStmtClassName();
  return 0;
}

Expr *ASTNodeImporter::VisitVAArgExpr(VAArgExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  Expr *SubExpr = Importer.Import(E->getSubExpr());
  if (!SubExpr && E->getSubExpr()) {
    assert(false);
    return NULL;
  }

  TypeSourceInfo *TInfo = Importer.Import(E->getWrittenTypeInfo());
  if (!TInfo) {
    assert(false);
    return 0;
  }

  return new (Importer.getToContext()) VAArgExpr(
        Importer.Import(E->getBuiltinLoc()), SubExpr, TInfo,
        Importer.Import(E->getRParenLoc()), T);
}

Expr *ASTNodeImporter::VisitGNUNullExpr(GNUNullExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  return new (Importer.getToContext()) GNUNullExpr(
        T, Importer.Import(E->getExprLoc()));
}

Expr *ASTNodeImporter::VisitPredefinedExpr(PredefinedExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  return new (Importer.getToContext()) PredefinedExpr(
        Importer.Import(E->getExprLoc()), T, E->getIdentType());
}

Expr *ASTNodeImporter::VisitInitListExpr(InitListExpr *ILE) {
  QualType T = Importer.Import(ILE->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  std::vector<Expr *> Exprs;
  for (InitListExpr::iterator I = ILE->begin(), E = ILE->end(); I != E; ++I) {
    if (Expr *Arg = cast_or_null<Expr>(Importer.Import(*I)))
      Exprs.push_back(Arg);
    else {
      assert(false);
      return NULL;
    }
  }

  InitListExpr *To = new (Importer.getToContext()) InitListExpr(
        Importer.getToContext(), Importer.Import(ILE->getLBraceLoc()), Exprs,
        Importer.Import(ILE->getLBraceLoc()));
  To->setType(T);

  if (ILE->hasArrayFiller()) {
    Expr *Filter = Importer.Import(ILE->getArrayFiller());
    if (!Filter && ILE->getArrayFiller()) {
      assert(false);
      return NULL;
    }
    To->setArrayFiller(Filter);
  }

  FieldDecl *ToFD = cast_or_null<FieldDecl>(
        Importer.Import(ILE->getInitializedFieldInUnion()));
  if (!ToFD && ILE->getInitializedFieldInUnion()) {
    assert(false);
    return NULL;
  }
  To->setInitializedFieldInUnion(ToFD);

  if (InitListExpr *SyntForm = ILE->getSyntacticForm()) {
    InitListExpr *ToSyntForm = cast_or_null<InitListExpr>(
          Importer.Import(SyntForm));
    if (!ToSyntForm) {
      assert(false);
      return NULL;
    }
    To->setSyntacticForm(ToSyntForm);
  }

  To->setValueDependent(ILE->isValueDependent());
  To->setInstantiationDependent(ILE->isInstantiationDependent());

  return To;
}

ASTNodeImporter::Designator
ASTNodeImporter::ImportDesignator(const Designator &D) {
  if (D.isFieldDesignator()) {
    IdentifierInfo *ToFieldName = Importer.Import(D.getFieldName());
    if (!ToFieldName) {
      assert(ToFieldName);
      return Designator();
    }
    return Designator(ToFieldName, Importer.Import(D.getDotLoc()),
                      Importer.Import(D.getFieldLoc()));
  }
  if (D.isArrayDesignator())
    return Designator(D.getFirstExprIndex(),
                      Importer.Import(D.getLBracketLoc()),
                      Importer.Import(D.getRBracketLoc()));

  // ArrayRangeDesignator
  return Designator(D.getFirstExprIndex(),
                    Importer.Import(D.getLBracketLoc()),
                    Importer.Import(D.getEllipsisLoc()),
                    Importer.Import(D.getRBracketLoc()));
}

Expr *ASTNodeImporter::VisitDesignatedInitExpr(DesignatedInitExpr *DIE) {
  Expr *Init = cast_or_null<Expr>(Importer.Import(DIE->getInit()));
  if (!Init) {
    assert(Init);
    return NULL;
  }

  std::vector<Expr *> IndexExprs;
  // List elements from the second, the first is Init itself
  for (unsigned i = 1, e = DIE->getNumSubExprs(); i < e; i++) {
    if (Expr *Arg = cast_or_null<Expr>(Importer.Import(DIE->getSubExpr(i))))
      IndexExprs.push_back(Arg);
    else {
      assert(Arg);
      return NULL;
    }
  }

  std::vector<Designator> Designators;
  for (DesignatedInitExpr::designators_iterator I = DIE->designators_begin(),
       E = DIE->designators_end(); I != E; ++I)
    Designators.push_back(ImportDesignator(*I));

  return DesignatedInitExpr::Create(
        Importer.getToContext(), Designators.data(), Designators.size(),
        IndexExprs, Importer.Import(DIE->getEqualOrColonLoc()),
        DIE->usesGNUSyntax(), Init);
}

Expr *ASTNodeImporter::VisitDeclRefExpr(DeclRefExpr *E) {
  ValueDecl *ToD = cast_or_null<ValueDecl>(Importer.Import(E->getDecl()));
  if (!ToD)
    return 0;

  NamedDecl *FoundD = 0;
  if (E->getDecl() != E->getFoundDecl()) {
    FoundD = cast_or_null<NamedDecl>(Importer.Import(E->getFoundDecl()));
    if (!FoundD)
      return 0;
  }
  
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  TemplateArgumentListInfo ToTAInfo;
  TemplateArgumentListInfo *ResInfo = NULL;
  if (E->hasExplicitTemplateArgs()) {
    const TemplateArgumentLoc *FromArgArray = E->getTemplateArgs();
    for (unsigned i = 0, e = E->getNumTemplateArgs(); i < e; i++) {
      const TemplateArgumentLoc &FromLoc = FromArgArray[i];
      ToTAInfo.addArgument(ImportTemplateArgumentLoc(FromLoc));
    }
    ResInfo = &ToTAInfo;
  }

  DeclRefExpr *DRE = DeclRefExpr::Create(Importer.getToContext(), 
                                         Importer.Import(E->getQualifierLoc()),
                                   Importer.Import(E->getTemplateKeywordLoc()),
                                         ToD,
                                         E->refersToEnclosingLocal(),
                                         Importer.Import(E->getLocation()),
                                         T, E->getValueKind(),
                                         FoundD,
                                         ResInfo);
  if (E->hadMultipleCandidates())
    DRE->setHadMultipleCandidates(true);
  DRE->setValueDependent(E->isValueDependent());
  DRE->setInstantiationDependent(E->isInstantiationDependent());
  return DRE;
}

Expr *ASTNodeImporter::VisitDependentScopeDeclRefExpr(
    DependentScopeDeclRefExpr *E) {
  DeclarationNameInfo NameInfo(Importer.Import(E->getDeclName()),
                               Importer.Import(E->getExprLoc()));
  ImportDeclarationNameLoc(E->getNameInfo(), NameInfo);

  TemplateArgumentListInfo ToTAInfo;
  TemplateArgumentListInfo *ResInfo = NULL;
  if (E->hasExplicitTemplateArgs()) {
    const TemplateArgumentLoc *FromArgArray = E->getTemplateArgs();
    for (unsigned i = 0, e = E->getNumTemplateArgs(); i < e; i++) {
      const TemplateArgumentLoc &FromLoc = FromArgArray[i];
      ToTAInfo.addArgument(ImportTemplateArgumentLoc(FromLoc));
    }
    ResInfo = &ToTAInfo;
  }

  return DependentScopeDeclRefExpr::Create(
        Importer.getToContext(), Importer.Import(E->getQualifierLoc()),
        Importer.Import(E->getTemplateKeywordLoc()), NameInfo, ResInfo);
}

Expr *ASTNodeImporter::VisitCXXNullPtrLiteralExpr(CXXNullPtrLiteralExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull())
    return 0;

  return new (Importer.getToContext()) CXXNullPtrLiteralExpr(
        T, Importer.Import(E->getExprLoc()));
}

Expr *ASTNodeImporter::VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull())
    return 0;

  return new (Importer.getToContext()) CXXBoolLiteralExpr(
        E->getValue(), T, Importer.Import(E->getExprLoc()));
}

Expr *ASTNodeImporter::VisitIntegerLiteral(IntegerLiteral *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull())
    return 0;

  return IntegerLiteral::Create(Importer.getToContext(), 
                                E->getValue(), T,
                                Importer.Import(E->getLocation()));
}

Expr *ASTNodeImporter::VisitFloatingLiteral(FloatingLiteral *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull())
    return 0;

  return FloatingLiteral::Create(Importer.getToContext(),
                                E->getValue(), E->isExact(), T,
                                Importer.Import(E->getLocation()));
}

Expr *ASTNodeImporter::VisitCharacterLiteral(CharacterLiteral *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull())
    return 0;
  
  return new (Importer.getToContext()) CharacterLiteral(E->getValue(),
                                                        E->getKind(), T,
                                          Importer.Import(E->getLocation()));
}

Expr *ASTNodeImporter::VisitStringLiteral(StringLiteral *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull())
    return 0;

  return StringLiteral::Create(Importer.getToContext(), E->getBytes(),
                               E->getKind(), E->isPascal(), T,
                               Importer.Import(E->getExprLoc()));
}

Expr *ASTNodeImporter::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull())
    return 0;

  TypeSourceInfo *TInfo = Importer.Import(E->getTypeSourceInfo());
  assert(TInfo);
  if (!TInfo)
    return NULL;

  Expr *Init = Importer.Import(E->getInitializer());
  assert(Init);
  if (!Init)
    return NULL;

  return new (Importer.getToContext()) CompoundLiteralExpr(
        Importer.Import(E->getLParenLoc()), TInfo, T, E->getValueKind(),
        Init, E->isFileScope());
}

Stmt *ASTNodeImporter::VisitGCCAsmStmt(GCCAsmStmt *S) {
  std::vector<IdentifierInfo *> Names;
  for (int i = 0, e = S->getNumOutputs(); i != e; i++) {
    IdentifierInfo *ToII = Importer.Import(S->getOutputIdentifier(i));
    Names.push_back(ToII);
    if (!ToII && S->getOutputIdentifier(i)) {
      assert(false);
      return NULL;
    }
  }
  for (int i = 0, e = S->getNumInputs(); i != e; i++) {
    IdentifierInfo *ToII = Importer.Import(S->getInputIdentifier(i));
    Names.push_back(ToII);
    if (!ToII && S->getInputIdentifier(i)) {
      assert(false);
      return NULL;
    }
  }

  std::vector<StringLiteral *> Clobbers;
  for (int i = 0, e = S->getNumClobbers(); i != e; i++)
    Clobbers.push_back(cast<StringLiteral>(
                         Importer.Import(S->getClobberStringLiteral(i))));

  std::vector<StringLiteral *> Constraints;
  for (int i = 0, e = S->getNumOutputs(); i != e; i++)
    Constraints.push_back(cast<StringLiteral>(
                            Importer.Import(S->getOutputConstraintLiteral(i))));
  for (int i = 0, e = S->getNumInputs(); i != e; i++)
    Constraints.push_back(cast<StringLiteral>(
                            Importer.Import(S->getInputConstraintLiteral(i))));

  std::vector<Expr *> Exprs;
  for (int i = 0, e = S->getNumOutputs(); i != e; i++) {
    if (Expr *Out = Importer.Import(S->getOutputExpr(i)))
      Exprs.push_back(Out);
    else {
      assert(false);
      return NULL;
    }
  }
  for (int i = 0, e = S->getNumInputs(); i != e; i++) {
    if (Expr *Out = Importer.Import(S->getInputExpr(i)))
      Exprs.push_back(Out);
    else {
      assert(false);
      return NULL;
    }
  }

  return new (Importer.getToContext()) GCCAsmStmt(
        Importer.getToContext(), Importer.Import(S->getAsmLoc()),
        S->isSimple(), S->isVolatile(), S->getNumOutputs(), S->getNumInputs(),
        Names.data(), Constraints.data(), Exprs.data(),
        cast<StringLiteral>(Importer.Import(S->getAsmString())),
        S->getNumClobbers(), Clobbers.data(),
        Importer.Import(S->getRParenLoc()));
}

Stmt *ASTNodeImporter::VisitGotoStmt(GotoStmt *S) {
  return new (Importer.getToContext()) GotoStmt(
        cast<LabelDecl>(Importer.Import(S->getLabel())),
        Importer.Import(S->getGotoLoc()), Importer.Import(S->getLabelLoc()));
}

Stmt *ASTNodeImporter::VisitIndirectGotoStmt(IndirectGotoStmt *S) {
  Expr *Target = Importer.Import(S->getTarget());
  assert(Target);
  if (!Target)
    return NULL;

  return new (Importer.getToContext()) IndirectGotoStmt(
        Importer.Import(S->getGotoLoc()), Importer.Import(S->getStarLoc()),
        Target);
}

Stmt *ASTNodeImporter::VisitLabelStmt(LabelStmt *S) {
  Stmt *ToSubStmt = Importer.Import(S->getSubStmt());
  assert(ToSubStmt);
  if (!ToSubStmt)
    return NULL;

  return new (Importer.getToContext()) LabelStmt(
        Importer.Import(S->getIdentLoc()),
        cast<LabelDecl>(Importer.Import(S->getDecl())), ToSubStmt);
}

Stmt *ASTNodeImporter::VisitAttributedStmt(AttributedStmt *S) {
  Stmt *ToSubStmt = Importer.Import(S->getSubStmt());
  if (!ToSubStmt) {
    assert(ToSubStmt);
    return NULL;
  }

  std::vector<const Attr *> ToAttrs;
  ArrayRef<const Attr *> FromAttrs = S->getAttrs();
  for (size_t i = 0, e = FromAttrs.size(); i < e; i++) {
    Attr *ToAttr = FromAttrs[i]->clone(Importer.getToContext());
    ToAttr->setRange(Importer.Import(FromAttrs[i]->getRange()));
    ToAttrs.push_back(ToAttr);
  }

  return AttributedStmt::Create(Importer.getToContext(),
                                Importer.Import(S->getLocStart()),
                                ToAttrs, ToSubStmt);
}

Stmt *ASTNodeImporter::VisitCompoundStmt(CompoundStmt *S) {
  std::vector<Stmt *> Stmts;
  for (CompoundStmt::body_iterator I = S->body_begin(), E = S->body_end();
       I != E; ++I) {
    if (Stmt *Out = Importer.Import(*I))
      Stmts.push_back(Out);
    else {
      assert(false);
      return NULL;
    }
  }

  return new (Importer.getToContext()) CompoundStmt(
        Importer.getToContext(), Stmts,
        Importer.Import(S->getLBracLoc()),
        Importer.Import(S->getRBracLoc()));
}

Stmt *ASTNodeImporter::VisitDeclStmt(DeclStmt *S) {
  std::vector<Decl *> Decls;
  for (DeclStmt::decl_iterator I = S->decl_begin(), E = S->decl_end();
       I != E; ++I) {
    Decl *D = Importer.Import(*I);
    assert(D);
    if (D)
      Decls.push_back(D);
    else
      return NULL;
  }
  assert(!Decls.empty());

  return new (Importer.getToContext()) DeclStmt(
        DeclGroupRef(DeclGroupRef::Create(Importer.getToContext(), Decls.data(),
                                          Decls.size())),
        Importer.Import(S->getStartLoc()),
        Importer.Import(S->getEndLoc()));
}

Stmt *ASTNodeImporter::VisitIfStmt(IfStmt *S) {
  VarDecl *ToCondVar = cast_or_null<VarDecl>(
        Importer.Import(S->getConditionVariable()));
  if (!ToCondVar && S->getConditionVariable()) {
    assert(false);
    return NULL;
  }

  Expr *ToCond = Importer.Import(S->getCond());
  assert(ToCond);
  if (!ToCond)
    return NULL;

  Stmt *ToThen = Importer.Import(S->getThen());
  assert(ToThen);
  if (!ToThen)
    return NULL;

  Stmt *ToElse = Importer.Import(S->getElse());
  if (!ToElse && S->getElse()) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) IfStmt(
        Importer.getToContext(), Importer.Import(S->getIfLoc()), ToCondVar,
        ToCond, ToThen, Importer.Import(S->getElseLoc()), ToElse);
}

Stmt *ASTNodeImporter::VisitForStmt(ForStmt *S) {
  VarDecl *ToCondVar = cast_or_null<VarDecl>(
        Importer.Import(S->getConditionVariable()));
  if (!ToCondVar && S->getConditionVariable()) {
    assert(false);
    return NULL;
  }

  Expr *ToCond = Importer.Import(S->getCond());
  if (!ToCond && S->getCond()) {
    assert(false);
    return NULL;
  }

  Expr *ToInc = Importer.Import(S->getInc());
  if (!ToInc && S->getInc()) {
    assert(false);
    return NULL;
  }

  Stmt *ToInit = Importer.Import(S->getInit());
  if (!ToInit && S->getInit()) {
    assert(false);
    return NULL;
  }

  Stmt *ToBody = Importer.Import(S->getBody());
  if (!ToBody && S->getBody()) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) ForStmt(
        Importer.getToContext(), ToInit, ToCond, ToCondVar, ToInc, ToBody,
        Importer.Import(S->getForLoc()),
        Importer.Import(S->getLParenLoc()), Importer.Import(S->getRParenLoc()));
}

Stmt *ASTNodeImporter::VisitDoStmt(DoStmt *S) {
  Expr *ToCond = Importer.Import(S->getCond());
  if (!ToCond && S->getCond()) {
    assert(false);
    return NULL;
  }

  Stmt *ToBody = Importer.Import(S->getBody());
  if (!ToBody && S->getBody()) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) DoStmt(
        ToBody, ToCond, Importer.Import(S->getDoLoc()),
        Importer.Import(S->getWhileLoc()), Importer.Import(S->getRParenLoc()));
}

Stmt *ASTNodeImporter::VisitWhileStmt(WhileStmt *S) {
  VarDecl *ToCondVar = cast_or_null<VarDecl>(
        Importer.Import(S->getConditionVariable()));
  if (!ToCondVar && S->getConditionVariable()) {
    assert(false);
    return NULL;
  }

  Expr *ToCond = Importer.Import(S->getCond());
  if (!ToCond && S->getCond()) {
    assert(false);
    return NULL;
  }

  Stmt *ToBody = Importer.Import(S->getBody());
  if (!ToBody && S->getBody()) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) WhileStmt(
        Importer.getToContext(), ToCondVar, ToCond, ToBody,
        Importer.Import(S->getWhileLoc()));
}

Stmt *ASTNodeImporter::VisitSwitchStmt(SwitchStmt *S) {
  VarDecl *ToCondVar = cast_or_null<VarDecl>(
        Importer.Import(S->getConditionVariable()));
  if (!ToCondVar && S->getConditionVariable()) {
    assert(false);
    return NULL;
  }

  Expr *ToCond = Importer.Import(S->getCond());
  if (!ToCond && S->getCond()) {
    assert(false);
    return NULL;
  }

  Stmt *ToBody = Importer.Import(S->getBody());
  if (!ToBody && S->getBody()) {
    assert(false);
    return NULL;
  }

  SwitchStmt *Res = new (Importer.getToContext()) SwitchStmt(
        Importer.getToContext(), ToCondVar, ToCond);
  Res->setBody(ToBody);

  // Import SwitchCase list
  SwitchCase *SCurrent = S->getSwitchCaseList();
  SwitchCase *Head = cast_or_null<SwitchCase>(
        Importer.Import(S->getSwitchCaseList()));
  if (!Head && SCurrent) {
    assert(false);
    return NULL;
  }

  SwitchCase *Current = Head;
  while (SCurrent) {
    SwitchCase *SNext = SCurrent->getNextSwitchCase();
    SwitchCase *Next = cast_or_null<SwitchCase>(Importer.Import(SNext));
    if (!Next && SNext) {
      assert(false);
      return NULL;
    }
    Current->setNextSwitchCase(Next);
    Current = Next;
    SCurrent = SNext;
  }
  Res->setSwitchCaseList(Head);
  if (S->isAllEnumCasesCovered())
    Res->setAllEnumCasesCovered();
  Res->setSwitchLoc(Importer.Import(S->getSwitchLoc()));
  return Res;
}

Stmt *ASTNodeImporter::VisitCaseStmt(CaseStmt *S) {
  Expr *ToLHS = Importer.Import(S->getLHS());
  if (!ToLHS && S->getLHS()) {
    assert(false);
    return NULL;
  }

  Expr *ToRHS = Importer.Import(S->getRHS());
  if (!ToRHS && S->getRHS()) {
    assert(false);
    return NULL;
  }

  Stmt *ToSubStmt = Importer.Import(S->getSubStmt());
  if (!ToSubStmt && S->getSubStmt()) {
    assert(false);
    return NULL;
  }

  CaseStmt *Res = new (Importer.getToContext()) CaseStmt(
        ToLHS, ToRHS,
        Importer.Import(S->getCaseLoc()), Importer.Import(S->getEllipsisLoc()),
        Importer.Import(S->getColonLoc()));
  Res->setSubStmt(ToSubStmt);
  return Res;
}

Stmt *ASTNodeImporter::VisitDefaultStmt(DefaultStmt *S) {
  Stmt *ToSubStmt = Importer.Import(S->getSubStmt());
  if (!ToSubStmt && S->getSubStmt()) {
    assert(false);
    return NULL;
  }
  return new (Importer.getToContext()) DefaultStmt(
        Importer.Import(S->getDefaultLoc()), Importer.Import(S->getColonLoc()),
        ToSubStmt);
}

Stmt *ASTNodeImporter::VisitContinueStmt(ContinueStmt *S) {
  return new (Importer.getToContext()) ContinueStmt(
        Importer.Import(S->getContinueLoc()));
}

Stmt *ASTNodeImporter::VisitBreakStmt(BreakStmt *S) {
  return new (Importer.getToContext()) BreakStmt(
        Importer.Import(S->getBreakLoc()));
}

Stmt *ASTNodeImporter::VisitNullStmt(NullStmt *S) {
  return new (Importer.getToContext()) NullStmt(
        Importer.Import(S->getSemiLoc()), S->hasLeadingEmptyMacro());
}

Stmt *ASTNodeImporter::VisitReturnStmt(ReturnStmt *S) {
  // FIXME: Refactor const_cast
  VarDecl *ToNRVO = cast_or_null<VarDecl>(
        Importer.Import(const_cast<VarDecl *>(S->getNRVOCandidate())));
  if (!ToNRVO && S->getNRVOCandidate()) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) ReturnStmt(
        Importer.Import(S->getReturnLoc()), Importer.Import(S->getRetValue()),
        ToNRVO);
}

Stmt *ASTNodeImporter::VisitCXXTryStmt(CXXTryStmt *S) {
  // FIXME: Refactor const_cast
  std::vector<Stmt *> Handlers;
  for (unsigned i = 0, e = S->getNumHandlers(); i < e; ++i) {
    if (Stmt *Handler = Importer.Import(const_cast<CXXCatchStmt *>(
                                          S->getHandler(i))))
      Handlers.push_back(Handler);
    else {
      assert(false);
      return NULL;
    }
  }
  return CXXTryStmt::Create(Importer.getToContext(),
                            Importer.Import(S->getTryLoc()),
                            Importer.Import(S->getTryBlock()),
                            Handlers);
}

Stmt *ASTNodeImporter::VisitCXXCatchStmt(CXXCatchStmt *S) {
  VarDecl *ToExcDecl = cast_or_null<VarDecl>(
        Importer.Import(S->getExceptionDecl()));
  if (!ToExcDecl && S->getExceptionDecl()) {
    assert(false);
    return NULL;
  }

  Stmt *Handler = Importer.Import(S->getHandlerBlock());
  assert(Handler);
  if (!Handler)
    return NULL;

  return new (Importer.getToContext()) CXXCatchStmt(
        Importer.Import(S->getCatchLoc()), ToExcDecl, Handler);
}

Expr *ASTNodeImporter::VisitAtomicExpr(AtomicExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  std::vector<Expr *> Exprs;
  for (int i = 0, e = E->getNumSubExprs(); i < e; ++i) {
    if (Expr *Ex = Importer.Import(E->getSubExprs()[i])) {
      Exprs.push_back(Ex);
    } else {
      assert(false);
      return NULL;
    }
  }

  return new (Importer.getToContext()) AtomicExpr(
        Importer.Import(E->getBuiltinLoc()), Exprs, T, E->getOp(),
        Importer.Import(E->getRParenLoc()));
}

Expr *ASTNodeImporter::VisitAddrLabelExpr(AddrLabelExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  LabelDecl *ToLabel = cast_or_null<LabelDecl>(Importer.Import(E->getLabel()));
  if (!ToLabel) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) AddrLabelExpr(
        Importer.Import(E->getAmpAmpLoc()), Importer.Import(E->getLabelLoc()),
        ToLabel, T);
}

Expr *ASTNodeImporter::VisitParenExpr(ParenExpr *E) {
  Expr *SubExpr = Importer.Import(E->getSubExpr());
  if (!SubExpr && E->getSubExpr()) {
    assert(false);
    return 0;
  }
  
  return new (Importer.getToContext()) 
                                  ParenExpr(Importer.Import(E->getLParen()),
                                            Importer.Import(E->getRParen()),
                                            SubExpr);
}

Expr *ASTNodeImporter::VisitParenListExpr(ParenListExpr *E) {
  std::vector<Expr *> Exprs;
  for (int i = 0, e = E->getNumExprs(); i < e; ++i) {
    if (Expr *Ex = Importer.Import(E->getExpr(i))) {
      Exprs.push_back(Ex);
    } else {
      assert(false);
      return NULL;
    }
  }

  return new (Importer.getToContext()) ParenListExpr(
        Importer.getToContext(), Importer.Import(E->getLParenLoc()),
        Exprs, Importer.Import(E->getLParenLoc()));
}

Expr *ASTNodeImporter::VisitStmtExpr(StmtExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  CompoundStmt *ToSubStmt = cast_or_null<CompoundStmt>(
        Importer.Import(E->getSubStmt()));
  if (!ToSubStmt && E->getSubStmt()) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) StmtExpr(ToSubStmt, T,
        Importer.Import(E->getLParenLoc()), Importer.Import(E->getRParenLoc()));
}

Expr *ASTNodeImporter::VisitUnaryOperator(UnaryOperator *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  Expr *SubExpr = Importer.Import(E->getSubExpr());
  if (!SubExpr) {
    assert(false);
    return 0;
  }
  
  return new (Importer.getToContext()) UnaryOperator(SubExpr, E->getOpcode(),
                                                     T, E->getValueKind(),
                                                     E->getObjectKind(),
                                         Importer.Import(E->getOperatorLoc()));                                        
}

Expr *ASTNodeImporter::VisitUnaryExprOrTypeTraitExpr(
                                            UnaryExprOrTypeTraitExpr *E) {
  QualType ResultType = Importer.Import(E->getType());
  if (ResultType.isNull()) {
    assert(false);
    return NULL;
  }
  
  if (E->isArgumentType()) {
    TypeSourceInfo *TInfo = Importer.Import(E->getArgumentTypeInfo());
    if (!TInfo) {
      assert(false);
      return 0;
    }
    
    return new (Importer.getToContext()) UnaryExprOrTypeTraitExpr(E->getKind(),
                                           TInfo, ResultType,
                                           Importer.Import(E->getOperatorLoc()),
                                           Importer.Import(E->getRParenLoc()));
  }
  
  Expr *SubExpr = Importer.Import(E->getArgumentExpr());
  if (!SubExpr) {
    assert(false);
    return 0;
  }
  
  return new (Importer.getToContext()) UnaryExprOrTypeTraitExpr(E->getKind(),
                                          SubExpr, ResultType,
                                          Importer.Import(E->getOperatorLoc()),
                                          Importer.Import(E->getRParenLoc()));
}

Expr *ASTNodeImporter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }
  Expr *ToLHS = Importer.Import(E->getLHS());
  if (!ToLHS && E->getLHS()) {
    assert(false);
    return NULL;
  }

  Expr *ToRHS = Importer.Import(E->getRHS());
  assert(ToRHS);
  if (!ToRHS && E->getRHS()) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) ArraySubscriptExpr(
        ToLHS, ToRHS, T, E->getValueKind(), E->getObjectKind(),
        Importer.Import(E->getRBracketLoc()));
}

Expr *ASTNodeImporter::VisitBinaryOperator(BinaryOperator *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  if (E->isLogicalOp())
    // This assertion is violated in dumped ASTs sometimes
    // assert(E->getType() == Importer.getFromContext().getLogicalOperationType());
    // FIXME: This is a hack since logical operators can be overloaded
    if (E->getType() != Importer.getFromContext().getLogicalOperationType())
      T = Importer.getToContext().getLogicalOperationType();

  Expr *LHS = Importer.Import(E->getLHS());
  if (!LHS) {
    assert(false);
    return 0;
  }
  
  Expr *RHS = Importer.Import(E->getRHS());
  if (!RHS) {
    assert(false);
    return 0;
  }
  
  return new (Importer.getToContext()) BinaryOperator(LHS, RHS, E->getOpcode(),
                                                      T, E->getValueKind(),
                                                      E->getObjectKind(),
                                           Importer.Import(E->getOperatorLoc()),
                                                      E->isFPContractable());
}

Expr *ASTNodeImporter::VisitConditionalOperator(ConditionalOperator *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  Expr *ToLHS = Importer.Import(E->getLHS());
  if (!ToLHS && E->getLHS()) {
    assert(false);
    return NULL;
  }

  Expr *ToRHS = Importer.Import(E->getRHS());
  assert(ToRHS);
  if (!ToRHS && E->getRHS()) {
    assert(false);
    return NULL;
  }

  Expr *ToCond = Importer.Import(E->getCond());
  if (!ToCond && E->getCond()) {
    assert(false);
    return NULL;
  }


  return new (Importer.getToContext()) ConditionalOperator(
        ToCond, Importer.Import(E->getQuestionLoc()),
        ToLHS, Importer.Import(E->getColonLoc()),
        ToRHS, T, E->getValueKind(), E->getObjectKind());
}

Expr *ASTNodeImporter::VisitBinaryConditionalOperator(
    BinaryConditionalOperator *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  Expr *Common = Importer.Import(E->getCommon());
  assert(Common);
  if (!Common)
    return NULL;

  Expr *Cond = Importer.Import(E->getCond());
  assert(Cond);
  if (!Cond)
    return NULL;

  OpaqueValueExpr *OpaqueValue = cast_or_null<OpaqueValueExpr>(
        Importer.Import(E->getOpaqueValue()));
  assert(OpaqueValue);
  if (!OpaqueValue)
    return NULL;

  Expr *TrueExpr = Importer.Import(E->getTrueExpr());
  assert(TrueExpr);
  if (!TrueExpr)
    return NULL;

  Expr *FalseExpr = Importer.Import(E->getFalseExpr());
  assert(FalseExpr);
  if (!FalseExpr)
    return NULL;

  return new (Importer.getToContext()) BinaryConditionalOperator(
        Common, OpaqueValue, Cond, TrueExpr, FalseExpr,
        Importer.Import(E->getQuestionLoc()), Importer.Import(E->getColonLoc()),
        T, E->getValueKind(), E->getObjectKind());
}

Expr *ASTNodeImporter::VisitBinaryTypeTraitExpr(BinaryTypeTraitExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  TypeSourceInfo *LhsType = Importer.Import(E->getLhsTypeSourceInfo());
  assert(LhsType);
  if (!LhsType)
    return NULL;

  TypeSourceInfo *RhsType = Importer.Import(E->getRhsTypeSourceInfo());
  assert(RhsType);
  if (!RhsType)
    return NULL;

  return new (Importer.getToContext()) BinaryTypeTraitExpr(
        Importer.Import(E->getExprLoc()), E->getTrait(), LhsType, RhsType,
        E->getValue(), Importer.Import(E->getLocEnd()), T);
}

Expr *ASTNodeImporter::VisitExpressionTraitExpr(ExpressionTraitExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  Expr *ToQueried = Importer.Import(E->getQueriedExpression());
  assert(ToQueried);
  if (!ToQueried)
    return NULL;

  return new (Importer.getToContext()) ExpressionTraitExpr(
        Importer.Import(E->getExprLoc()), E->getTrait(), ToQueried,
        E->getValue(), Importer.Import(E->getLocEnd()), T);
}

Expr *ASTNodeImporter::VisitOpaqueValueExpr(OpaqueValueExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  Expr *SourceExpr = Importer.Import(E->getSourceExpr());
  if (!SourceExpr && E->getSourceExpr()) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) OpaqueValueExpr(
        Importer.Import(E->getExprLoc()), T, E->getValueKind(),
        E->getObjectKind(), SourceExpr);
}

Expr *ASTNodeImporter::VisitCompoundAssignOperator(CompoundAssignOperator *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }
  
  QualType CompLHSType = Importer.Import(E->getComputationLHSType());
  if (CompLHSType.isNull()) {
    assert(false);
    return NULL;
  }
  
  QualType CompResultType = Importer.Import(E->getComputationResultType());
  if (CompResultType.isNull()) {
    assert(false);
    return NULL;
  }

  Expr *ToLHS = Importer.Import(E->getLHS());
  if (!ToLHS && E->getLHS()) {
    assert(false);
    return NULL;
  }

  Expr *ToRHS = Importer.Import(E->getRHS());
  assert(ToRHS);
  if (!ToRHS && E->getRHS()) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) 
                        CompoundAssignOperator(ToLHS, ToRHS, E->getOpcode(),
                                               T, E->getValueKind(),
                                               E->getObjectKind(),
                                               CompLHSType, CompResultType,
                                           Importer.Import(E->getOperatorLoc()),
                                               E->isFPContractable());
}

bool ASTNodeImporter::ImportCastPath(CastExpr *CE, CXXCastPath &Path) {
  for (CastExpr::path_iterator I = CE->path_begin(), E = CE->path_end(); I != E;
       ++I) {
    if (CXXBaseSpecifier *Spec = Importer.Import(*I))
      Path.push_back(Spec);
    else
      return true;
  }
  return false;
}

Expr *ASTNodeImporter::VisitImplicitCastExpr(ImplicitCastExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  Expr *SubExpr = Importer.Import(E->getSubExpr());
  if (!SubExpr) {
    assert(false);
    return 0;
  }

  CXXCastPath BasePath;
  if (ImportCastPath(E, BasePath)) {
    assert(false);
    return 0;
  }

  return ImplicitCastExpr::Create(Importer.getToContext(), T, E->getCastKind(),
                                  SubExpr, &BasePath, E->getValueKind());
}

Expr *ASTNodeImporter::VisitExplicitCastExpr(ExplicitCastExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }
  
  Expr *SubExpr = Importer.Import(E->getSubExpr());
  if (!SubExpr) {
    assert(false);
    return 0;
  }

  TypeSourceInfo *TInfo = Importer.Import(E->getTypeInfoAsWritten());
  if (!TInfo && E->getTypeInfoAsWritten()) {
    assert(false);
    return 0;
  }
  
  CXXCastPath BasePath;
  if (ImportCastPath(E, BasePath)) {
    assert(false);
    return 0;
  }

  switch (E->getStmtClass()) {
  case Stmt::CStyleCastExprClass: {
    CStyleCastExpr *CCE = cast<CStyleCastExpr>(E);
    return CStyleCastExpr::Create(Importer.getToContext(), T,
                                  E->getValueKind(), E->getCastKind(),
                                  SubExpr, &BasePath, TInfo,
                                  Importer.Import(CCE->getLParenLoc()),
                                  Importer.Import(CCE->getRParenLoc()));
  }

  case Stmt::CXXFunctionalCastExprClass: {
    CXXFunctionalCastExpr *FCE = cast<CXXFunctionalCastExpr>(E);
    return CXXFunctionalCastExpr::Create(Importer.getToContext(), T,
                                         E->getValueKind(), TInfo,
                                         E->getCastKind(), SubExpr, &BasePath,
                                         Importer.Import(FCE->getLParenLoc()),
                                         Importer.Import(FCE->getRParenLoc()));
  }

  case Stmt::ObjCBridgedCastExprClass: {
      ObjCBridgedCastExpr *OCE = cast<ObjCBridgedCastExpr>(E);
      return new (Importer.getToContext()) ObjCBridgedCastExpr(
            Importer.Import(OCE->getLParenLoc()), OCE->getBridgeKind(),
            E->getCastKind(), Importer.Import(OCE->getBridgeKeywordLoc()),
            TInfo, SubExpr);
  }
  default:
    break; // just fall through
  }

  CXXNamedCastExpr *Named = cast<CXXNamedCastExpr>(E);
  SourceLocation ExprLoc = Importer.Import(Named->getExprLoc()),
      RParenLoc = Importer.Import(Named->getRParenLoc());
  SourceRange Brackets = Importer.Import(Named->getAngleBrackets());

  switch (E->getStmtClass()) {
  case Stmt::CXXStaticCastExprClass:
    return CXXStaticCastExpr::Create(Importer.getToContext(), T,
                                     E->getValueKind(), E->getCastKind(),
                                     SubExpr, &BasePath, TInfo,
                                     ExprLoc, RParenLoc, Brackets);

  case Stmt::CXXDynamicCastExprClass:
    return CXXDynamicCastExpr::Create(Importer.getToContext(), T,
                                      E->getValueKind(), E->getCastKind(),
                                      SubExpr, &BasePath, TInfo,
                                      ExprLoc, RParenLoc, Brackets);

  case Stmt::CXXReinterpretCastExprClass:
    return CXXReinterpretCastExpr::Create(Importer.getToContext(), T,
                                          E->getValueKind(), E->getCastKind(),
                                          SubExpr, &BasePath, TInfo,
                                          ExprLoc, RParenLoc, Brackets);

  case Stmt::CXXConstCastExprClass:
    return CXXConstCastExpr::Create(Importer.getToContext(), T,
                                    E->getValueKind(), SubExpr, TInfo, ExprLoc,
                                    RParenLoc, Brackets);
  default:
    return NULL; // unreachable
  }
}

Expr *ASTNodeImporter::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  return new (Importer.getToContext()) ImplicitValueInitExpr(T);
}

Expr *ASTNodeImporter::VisitOffsetOfExpr(OffsetOfExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  std::vector<OffsetOfExpr::OffsetOfNode> Nodes;
  for (int i = 0, e = E->getNumComponents(); i < e; ++i) {
    // TODO: Make a separate Import(OffsetOfExpr::OffsetOfNode &)?
    const OffsetOfExpr::OffsetOfNode &Node = E->getComponent(i);
    switch (Node.getKind()) {
    case OffsetOfExpr::OffsetOfNode::Array:
      Nodes.push_back(OffsetOfExpr::OffsetOfNode(
                        Importer.Import(Node.getLocStart()),
                        Node.getArrayExprIndex(),
                        Importer.Import(Node.getLocEnd())));
      break;
    case OffsetOfExpr::OffsetOfNode::Base: {
      CXXBaseSpecifier *BS = Importer.Import(Node.getBase());
      if (!BS && Node.getBase()) {
        assert(false);
        return NULL;
      }
      Nodes.push_back(OffsetOfExpr::OffsetOfNode(BS));
      break;
    }
    case OffsetOfExpr::OffsetOfNode::Field:
      Nodes.push_back(OffsetOfExpr::OffsetOfNode(
                        Importer.Import(Node.getLocStart()),
                        cast<FieldDecl>(Importer.Import(Node.getField())),
                        Importer.Import(Node.getLocEnd())));
      break;
    case OffsetOfExpr::OffsetOfNode::Identifier: {
      IdentifierInfo *ToII = Importer.Import(Node.getFieldName());
      if (ToII) {
        assert(false);
        return NULL;
      }
      Nodes.push_back(OffsetOfExpr::OffsetOfNode(
                        Importer.Import(Node.getLocStart()), ToII,
                        Importer.Import(Node.getLocEnd())));
      break;
    }
    }
  }

  std::vector<Expr *> Exprs;
  for (int i = 0, e = E->getNumExpressions(); i < e; ++i) {
    Expr *ToIndexExpr = Importer.Import(E->getIndexExpr(i));
    if (!ToIndexExpr) {
      assert(false);
      return NULL;
    }
    Exprs.push_back(ToIndexExpr);
  }

  TypeSourceInfo *TInfo = Importer.Import(E->getTypeSourceInfo());
  if (!TInfo && E->getTypeSourceInfo()) {
    assert(false);
    return NULL;
  }

  return OffsetOfExpr::Create(Importer.getToContext(), T,
                              Importer.Import(E->getOperatorLoc()),
                              TInfo, Nodes, Exprs,
                              Importer.Import(E->getRParenLoc()));
}

Expr *ASTNodeImporter::VisitUnaryTypeTraitExpr(UnaryTypeTraitExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  TypeSourceInfo *TInfo = Importer.Import(E->getQueriedTypeSourceInfo());
  if (!TInfo) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) UnaryTypeTraitExpr(
        Importer.Import(E->getExprLoc()), E->getTrait(), TInfo, E->getValue(),
        Importer.Import(E->getLocEnd()), T);
}

Expr *ASTNodeImporter::VisitCXXThisExpr(CXXThisExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  return new (Importer.getToContext()) CXXThisExpr(
        Importer.Import(E->getExprLoc()), T, E->isImplicit());
}

Expr *ASTNodeImporter::VisitCXXNoexceptExpr(CXXNoexceptExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  Expr *Operand = Importer.Import(E->getOperand());
  assert(Operand);
  if (!Operand)
    return NULL;

  // We cannot get source CanThrowVal so correction is required after init
  CXXNoexceptExpr *ToE = new (Importer.getToContext()) CXXNoexceptExpr(
        T, Operand, E->getValue() ? CT_Cannot : CT_Dependent,
        Importer.Import(E->getLocStart()), Importer.Import(E->getLocEnd()));
  ToE->setInstantiationDependent(E->isInstantiationDependent());
  ToE->setValueDependent(E->isValueDependent());
  return ToE;
}

Expr *ASTNodeImporter::VisitCXXThrowExpr(CXXThrowExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  Expr *SubExpr = Importer.Import(E->getSubExpr());
  if (!SubExpr && E->getSubExpr()) {
    assert(false);
    return 0;
  }

  return new (Importer.getToContext()) CXXThrowExpr(
        SubExpr, T, Importer.Import(E->getExprLoc()),
        E->isThrownVariableInScope());
}

Expr *ASTNodeImporter::VisitCXXDefaultArgExpr(CXXDefaultArgExpr *E) {
  ParmVarDecl *Param = cast_or_null<ParmVarDecl>(Importer.Import(E->getParam()));
  if (!Param && E->getParam()) {
    assert(false);
    return NULL;
  }

  Expr *SubExpr = Importer.Import(E->getExpr());
  if (!SubExpr && E->getExpr()) {
    assert(false);
    return 0;
  }

  return CXXDefaultArgExpr::Create(
        Importer.getToContext(), Importer.Import(E->getExprLoc()),
        Param, SubExpr);
}

Expr *ASTNodeImporter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  TypeSourceInfo *TypeInfo = Importer.Import(E->getTypeSourceInfo());
  assert(TypeInfo);
  if (!TypeInfo)
    return NULL;

  return new (Importer.getToContext()) CXXScalarValueInitExpr(
        T, TypeInfo, Importer.Import(E->getRParenLoc()));
}

Expr *ASTNodeImporter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
  Expr *SubExpr = Importer.Import(E->getSubExpr());
  if (!SubExpr && E->getSubExpr()) {
    assert(false);
    return 0;
  }

  return CXXBindTemporaryExpr::Create(
        Importer.getToContext(),
        CXXTemporary::Create(
          Importer.getToContext(),
          cast<CXXDestructorDecl>(Importer.Import(
                                    const_cast<CXXDestructorDecl *>(
                                    E->getTemporary()->getDestructor())))),
        SubExpr);
}

Expr *ASTNodeImporter::VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *CE) {
  QualType T = Importer.Import(CE->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  std::vector<Expr *> Args;
  for (CXXTemporaryObjectExpr::arg_iterator I = CE->arg_begin(),
       E = CE->arg_end(); I != E; ++I) {
    if (Expr *Arg = Importer.Import(*I))
      Args.push_back(Arg);
    else {
      assert(false);
      return NULL;
    }
  }

  return CXXTemporaryObjectExpr::Create(
        Importer.getToContext(), T, Importer.Import(CE->getExprLoc()),
        cast<CXXConstructorDecl>(Importer.Import(CE->getConstructor())),
        CE->isElidable(), Args,
        CE->hadMultipleCandidates(), CE->isListInitialization(),
        CE->requiresZeroInitialization(), CE->getConstructionKind(),
        Importer.Import(CE->getParenOrBraceRange()));
}

Expr *ASTNodeImporter::VisitMemberExpr(MemberExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return 0;
  }

  Expr *BaseE = Importer.Import(E->getBase());
  if (!BaseE && E->getBase()) {
    assert(false);
    return NULL;
  }

  DeclAccessPair FoundDecl = E->getFoundDecl();
  NamedDecl *ND = cast<NamedDecl>(Importer.Import(FoundDecl.getDecl()));
  DeclAccessPair ImportedFoundDecl =
      DeclAccessPair::make(ND, FoundDecl.getAccess());

  ValueDecl *MD = cast<ValueDecl>(Importer.Import(E->getMemberDecl()));

  DeclarationNameInfo NameInfo(MD->getDeclName(),
                               Importer.Import(E->getMemberLoc()));
  ImportDeclarationNameLoc(E->getMemberNameInfo(), NameInfo);

  TemplateArgumentListInfo ToTAInfo;
  TemplateArgumentListInfo *ResInfo = NULL;
  if (E->hasExplicitTemplateArgs()) {
    const TemplateArgumentLoc *FromArgArray = E->getTemplateArgs();
    for (unsigned i = 0, e = E->getNumTemplateArgs(); i < e; i++) {
      const TemplateArgumentLoc &FromLoc = FromArgArray[i];
      ToTAInfo.addArgument(ImportTemplateArgumentLoc(FromLoc));
    }
    ResInfo = &ToTAInfo;
  }

  return MemberExpr::Create(Importer.getToContext(),
                            BaseE, E->isArrow(),
                            Importer.Import(E->getQualifierLoc()),
                            Importer.Import(E->getTemplateKeywordLoc()), MD,
                            ImportedFoundDecl, NameInfo, ResInfo,
                            T, E->getValueKind(), E->getObjectKind());
}

Expr *
ASTNodeImporter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  Expr *TempE = Importer.Import(E->GetTemporaryExpr());
  assert(TempE);
  if (!TempE)
    return NULL;

  ValueDecl *VD = cast_or_null<ValueDecl>(
        Importer.Import(const_cast<ValueDecl *>(E->getExtendingDecl())));
  if (!VD && E->getExtendingDecl()) {
    assert(false);
    return NULL;
  }

  // FIXME: Refactor const_cast
  return new (Importer.getToContext()) MaterializeTemporaryExpr(
        T, TempE, E->isBoundToLvalueReference(), VD);
}

Expr *ASTNodeImporter::VisitOverloadExpr(OverloadExpr *E) {
  QualType BaseType = Importer.Import(E->getType());
  if (BaseType.isNull())
    return NULL;

  DeclarationName Name = Importer.Import(E->getName());
  assert(Name);
  if (!Name) {
    assert(false);
    return NULL;
  }

  DeclarationNameInfo NameInfo(Name, Importer.Import(E->getNameLoc()));
  ImportDeclarationNameLoc(E->getNameInfo(), NameInfo);

  TemplateArgumentListInfo ToTAInfo;
  TemplateArgumentListInfo *ResInfo = NULL;
  if (E->hasExplicitTemplateArgs()) {
    const TemplateArgumentLoc *FromArgArray = E->getTemplateArgs();
    for (unsigned i = 0, e = E->getNumTemplateArgs(); i < e; i++) {
      const TemplateArgumentLoc &FromLoc = FromArgArray[i];
      ToTAInfo.addArgument(ImportTemplateArgumentLoc(FromLoc));
    }
    ResInfo = &ToTAInfo;
  }

  UnresolvedSet<2> USet;
  for (UnresolvedMemberExpr::decls_iterator UI = E->decls_begin(),
       UE = E->decls_end(); UI != UE; ++UI)
    USet.addDecl(cast<NamedDecl>(Importer.Import(*UI)));

  if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) {
    CXXRecordDecl *NamingClass = cast_or_null<CXXRecordDecl>(
          Importer.Import(ULE->getNamingClass()));
    if (!NamingClass && ULE->getNamingClass()) {
      assert(false);
      return NULL;
    }
    if (ResInfo || ULE->getTemplateKeywordLoc().isValid())
      return UnresolvedLookupExpr::Create(
            Importer.getToContext(), NamingClass,
            Importer.Import(E->getQualifierLoc()),
            Importer.Import(E->getTemplateKeywordLoc()), NameInfo,
            ULE->requiresADL(), ResInfo, USet.begin(), USet.end());
    else
      return UnresolvedLookupExpr::Create(
            Importer.getToContext(), NamingClass,
            Importer.Import(E->getQualifierLoc()), NameInfo,
            ULE->requiresADL(), ULE->isOverloaded(), USet.begin(), USet.end());
  }
  UnresolvedMemberExpr *UME = cast<UnresolvedMemberExpr>(E);
  Expr *BaseE = UME->isImplicitAccess() ? NULL : Importer.Import(UME->getBase());
  if (!BaseE && !UME->isImplicitAccess() && UME->getBase()) {
    assert(false);
    return NULL;
  }

  return UnresolvedMemberExpr::Create(
        Importer.getToContext(), UME->hasUnresolvedUsing(), BaseE, BaseType,
        UME->isArrow(), Importer.Import(UME->getOperatorLoc()),
        Importer.Import(E->getQualifierLoc()),
        Importer.Import(E->getTemplateKeywordLoc()), NameInfo,
        ResInfo, USet.begin(), USet.end());
}

Expr *ASTNodeImporter::VisitCXXDependentScopeMemberExpr(
    CXXDependentScopeMemberExpr *E) {

  DeclarationName Name = Importer.Import(E->getMember());
  assert(Name);
  if (!Name)
    return NULL;

  DeclarationNameInfo NameInfo(Name, Importer.Import(E->getMemberLoc()));
  ImportDeclarationNameLoc(E->getMemberNameInfo(), NameInfo);

  TemplateArgumentListInfo ToTAInfo;
  TemplateArgumentListInfo *ResInfo = NULL;
  if (E->hasExplicitTemplateArgs()) {
    const TemplateArgumentLoc *FromArgArray = E->getTemplateArgs();
    for (unsigned i = 0, e = E->getNumTemplateArgs(); i < e; i++) {
      const TemplateArgumentLoc &FromLoc = FromArgArray[i];
      ToTAInfo.addArgument(ImportTemplateArgumentLoc(FromLoc));
    }
    ResInfo = &ToTAInfo;
  }

  Expr *BaseE = NULL;
  if (!E->isImplicitAccess()) {
    BaseE = Importer.Import(E->getBase());
    assert(BaseE);
    if (!BaseE)
      return NULL;
  }

  return CXXDependentScopeMemberExpr::Create(
        Importer.getToContext(), BaseE,
        Importer.Import(E->getBaseType()), E->isArrow(),
        Importer.Import(E->getOperatorLoc()),
        Importer.Import(E->getQualifierLoc()),
        Importer.Import(E->getTemplateKeywordLoc()),
        cast_or_null<NamedDecl>(Importer.Import(
                                  E->getFirstQualifierFoundInScope())),
        NameInfo, ResInfo);
}

Expr *ASTNodeImporter::VisitCXXUnresolvedConstructExpr(
    CXXUnresolvedConstructExpr *CE) {
  std::vector<Expr *> Args;
  for (CXXUnresolvedConstructExpr::arg_iterator I = CE->arg_begin(),
       E = CE->arg_end(); I != E; ++I) {
    if (Expr *Arg = Importer.Import(*I))
      Args.push_back(Arg);
    else {
      assert(false);
      return NULL;
    }
  }

  return CXXUnresolvedConstructExpr::Create(
        Importer.getToContext(), Importer.Import(CE->getTypeSourceInfo()),
        Importer.Import(CE->getLParenLoc()), Args,
        Importer.Import(CE->getRParenLoc()));
}

Expr *ASTNodeImporter::VisitCXXPseudoDestructorExpr(
    CXXPseudoDestructorExpr *E) {
  Expr *BaseE = Importer.Import(E->getBase());
  assert(BaseE);
  if (!BaseE)
    return NULL;

  // May be NULL?
  TypeSourceInfo *ScopeInfo = Importer.Import(E->getScopeTypeInfo());

  PseudoDestructorTypeStorage Storage;
  if (IdentifierInfo *FromII = E->getDestroyedTypeIdentifier()) {
    IdentifierInfo *ToII = Importer.Import(FromII);
    assert(ToII);
    if (!ToII)
      return NULL;
    Storage = PseudoDestructorTypeStorage(
          ToII, Importer.Import(E->getDestroyedTypeLoc()));
  } else {
    TypeSourceInfo *TI = Importer.Import(E->getDestroyedTypeInfo());
    assert(TI);
    if (!TI)
      return NULL;
    Storage = PseudoDestructorTypeStorage(TI);
  }

  return new (Importer.getToContext()) CXXPseudoDestructorExpr(
        Importer.getToContext(), BaseE, E->isArrow(),
        Importer.Import(E->getOperatorLoc()),
        Importer.Import(E->getQualifierLoc()),
        ScopeInfo, Importer.Import(E->getColonColonLoc()),
        Importer.Import(E->getTildeLoc()), Storage);
}

Expr *ASTNodeImporter::VisitSubstNonTypeTemplateParmExpr(
    SubstNonTypeTemplateParmExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  NonTypeTemplateParmDecl *Param = cast_or_null<NonTypeTemplateParmDecl>(
        Importer.Import(E->getParameter()));
  assert(Param);
  if (!Param)
    return NULL;

  Expr *Replacement = Importer.Import(E->getReplacement());
  if (!Replacement) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) SubstNonTypeTemplateParmExpr(
        T, E->getValueKind(), Importer.Import(E->getExprLoc()), Param,
        Replacement);
}

Expr *ASTNodeImporter::VisitPackExpansionExpr(PackExpansionExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  Expr *Pattern = Importer.Import(E->getPattern());
  if (!Pattern) {
    assert(false);
    return NULL;
  }
  return new (Importer.getToContext()) PackExpansionExpr(
        T, Pattern, Importer.Import(E->getEllipsisLoc()),
        E->getNumExpansions());
}

Expr *ASTNodeImporter::VisitSizeOfPackExpr(SizeOfPackExpr *E) {
  QualType T = Importer.Import(E->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  NamedDecl *Pack = cast_or_null<NamedDecl>(E->getPack());
  assert(Pack);
  if (!Pack)
    return NULL;

  if (E->isValueDependent())
    return new (Importer.getToContext()) SizeOfPackExpr(
          T, Importer.Import(E->getOperatorLoc()), Pack,
          Importer.Import(E->getPackLoc()), Importer.Import(E->getRParenLoc()));

  return new (Importer.getToContext()) SizeOfPackExpr(
        T, Importer.Import(E->getOperatorLoc()), Pack,
        Importer.Import(E->getPackLoc()), Importer.Import(E->getRParenLoc()),
        E->getPackLength());
}

Expr *ASTNodeImporter::VisitCXXNewExpr(CXXNewExpr *CE) {
  QualType T = Importer.Import(CE->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  std::vector<Expr *> PlacementArgs;
  for (CXXNewExpr::arg_iterator I = CE->placement_arg_begin(),
       E = CE->placement_arg_end(); I != E; ++I) {
    if (Expr *Arg = Importer.Import(*I))
      PlacementArgs.push_back(Arg);
    else {
      assert(false);
      return NULL;
    }
  }

  FunctionDecl *OperatorNewDecl = cast_or_null<FunctionDecl>(
        Importer.Import(CE->getOperatorNew()));
  assert(OperatorNewDecl || !CE->getOperatorNew());
  FunctionDecl *OperatorDeleteDecl = cast_or_null<FunctionDecl>(
        Importer.Import(CE->getOperatorDelete()));
  assert(OperatorDeleteDecl || !CE->getOperatorDelete());

  Expr *ToInit = Importer.Import(CE->getInitializer());
  if (!ToInit && CE->getInitializer()) {
    assert(false);
    return NULL;
  }

  TypeSourceInfo *TI = Importer.Import(CE->getAllocatedTypeSourceInfo());
  assert(TI);
  if (!TI)
    return NULL;

  Expr *ToArrSize = Importer.Import(CE->getArraySize());
  if (!ToArrSize && CE->getArraySize()) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) CXXNewExpr(
        Importer.getToContext(), CE->isGlobalNew(),
        OperatorNewDecl, OperatorDeleteDecl,
        CE->doesUsualArrayDeleteWantSize(), PlacementArgs,
        Importer.Import(CE->getTypeIdParens()),
        ToArrSize, CE->getInitializationStyle(), ToInit, T, TI,
        Importer.Import(CE->getSourceRange()),
        Importer.Import(CE->getDirectInitRange()));
}

Expr *ASTNodeImporter::VisitCXXDeleteExpr(CXXDeleteExpr *E) {
  QualType T = Importer.Import(E->getType());
  assert(!T.isNull());
  if (T.isNull())
    return NULL;

  FunctionDecl *OperatorDeleteDecl = cast_or_null<FunctionDecl>(
        Importer.Import(E->getOperatorDelete()));
  assert(OperatorDeleteDecl || !E->getOperatorDelete());
  if (!OperatorDeleteDecl && E->getOperatorDelete())
    return NULL;

  Expr *ToArg = Importer.Import(E->getArgument());
  if (!ToArg && E->getArgument()) {
    assert(false);
    return NULL;
  }

  return new (Importer.getToContext()) CXXDeleteExpr(
        T, E->isGlobalDelete(), E->isArrayForm(), E->isArrayFormAsWritten(),
        E->doesUsualArrayDeleteWantSize(),
        OperatorDeleteDecl, ToArg, Importer.Import(E->getExprLoc()));
}

Expr *ASTNodeImporter::VisitCXXConstructExpr(CXXConstructExpr *CE) {
  QualType T = Importer.Import(CE->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  std::vector<Expr *> Args;
  for (CXXConstructExpr::arg_iterator I = CE->arg_begin(), E = CE->arg_end();
       I != E; ++I) {
    if (Expr *Arg = Importer.Import(*I))
      Args.push_back(Arg);
    else {
      assert(false);
      return NULL;
    }
  }

  return CXXConstructExpr::Create(
        Importer.getToContext(), T, Importer.Import(CE->getExprLoc()),
        cast<CXXConstructorDecl>(Importer.Import(CE->getConstructor())),
        CE->isElidable(), Args, CE->hadMultipleCandidates(),
        CE->isListInitialization(), CE->requiresZeroInitialization(),
        CE->getConstructionKind(), Importer.Import(CE->getParenOrBraceRange()));
}

Expr *ASTNodeImporter::VisitExprWithCleanups(ExprWithCleanups *E) {
  Expr *SubExpr = Importer.Import(E->getSubExpr());
  if (!SubExpr && E->getSubExpr()) {
    assert(false);
    return NULL;
  }

  std::vector<ExprWithCleanups::CleanupObject> Objs;
  for (unsigned i = 0, e = E->getNumObjects(); i < e; i++)
    if (ExprWithCleanups::CleanupObject Obj =
        cast<BlockDecl>(Importer.Import(E->getObject(i))))
      Objs.push_back(Obj);
    else {
      assert(false);
      return NULL;
    }

  return ExprWithCleanups::Create(Importer.getToContext(), SubExpr, Objs);
}

Expr *ASTNodeImporter::VisitCallExpr(CallExpr *CE) {
  QualType T = Importer.Import(CE->getType());
  if (T.isNull()) {
    assert(false);
    return NULL;
  }

  Expr *Callee = Importer.Import(CE->getCallee());
  if (!Callee && CE->getCallee()) {
    assert(false);
    return NULL;
  }
  std::vector<Expr *> Args;
  for (CallExpr::arg_iterator I = CE->arg_begin(), E = CE->arg_end(); I != E;
       ++I) {
    if (Expr *Arg = Importer.Import(*I))
      Args.push_back(Arg);
    else {
      assert(false);
      return NULL;
    }
  }

  if (isa<CXXMemberCallExpr>(CE))
    return new (Importer.getToContext()) CXXMemberCallExpr(
          Importer.getToContext(), Callee, Args, T, CE->getValueKind(),
          Importer.Import(CE->getRParenLoc()));

  if (CXXOperatorCallExpr *OCE = dyn_cast<CXXOperatorCallExpr>(CE))
    return new (Importer.getToContext()) CXXOperatorCallExpr(
          Importer.getToContext(), OCE->getOperator(), Callee, Args, T,
          CE->getValueKind(), Importer.Import(OCE->getOperatorLoc()),
          OCE->isFPContractable());

  return new (Importer.getToContext()) CallExpr(
        Importer.getToContext(), Callee, Args, T, CE->getValueKind(),
        Importer.Import(CE->getRParenLoc()));
}


ASTImporter::ASTImporter(ASTContext &ToContext, FileManager &ToFileManager,
                         ASTContext &FromContext, FileManager &FromFileManager,
                         bool MinimalImport)
  : ToContext(ToContext), FromContext(FromContext),
    FromSema(NULL), ToSema(NULL),
    ToFileManager(ToFileManager), FromFileManager(FromFileManager),
    Minimal(MinimalImport), LastDiagFromFrom(false)
{
  ImportedDecls[FromContext.getTranslationUnitDecl()]
    = ToContext.getTranslationUnitDecl();
}

ASTImporter::~ASTImporter() { }

QualType ASTImporter::Import(QualType FromT) {
  if (FromT.isNull())
    return QualType();

  const Type *fromTy = FromT.getTypePtr();
  
  // Check whether we've already imported this type.  
  llvm::DenseMap<const Type *, const Type *>::iterator Pos
    = ImportedTypes.find(fromTy);
  if (Pos != ImportedTypes.end())
    return ToContext.getQualifiedType(Pos->second, FromT.getLocalQualifiers());
  
  // Import the type
  ASTNodeImporter Importer(*this);
  QualType ToT = Importer.Visit(fromTy);
  assert(!ToT.isNull());
  if (ToT.isNull())
    return ToT;
  
  // Record the imported type.
  ImportedTypes[fromTy] = ToT.getTypePtr();
  
  return ToContext.getQualifiedType(ToT, FromT.getLocalQualifiers());
}

TypeSourceInfo *ASTImporter::Import(TypeSourceInfo *FromTSI) {
  if (!FromTSI)
    return FromTSI;

  // FIXME: For now we just create a "trivial" type source info based
  // on the type and a single location. Implement a real version of this.
  QualType T = Import(FromTSI->getType());
  if (T.isNull())
    return 0;

  return ToContext.getTrivialTypeSourceInfo(T, 
                        Import(FromTSI->getTypeLoc().getLocStart()));
}

Decl *ASTImporter::GetImported(Decl *FromD) {
  llvm::DenseMap<Decl *, Decl *>::iterator Pos = ImportedDecls.find(FromD);
  return Pos != ImportedDecls.end() ? Pos->second : NULL;
}

Decl *ASTImporter::Import(Decl *FromD) {
  if (!FromD)
    return 0;

  ASTNodeImporter Importer(*this);

  // Check whether we've already imported this declaration.  
  if (Decl *ToD = GetImported(FromD)) {
    Importer.ImportDefinitionIfNeeded(FromD, ToD);
    return ToD;
  }
  
  // Import the type
  Decl *ToD = Importer.Visit(FromD);
  if (!ToD)
    return 0;
  
  // Record the imported declaration.
  ImportedDecls[FromD] = ToD;

  // Keep linkage information
  if (ToD->hasCachedLinkage())
    ToD->setCachedLinkage(FromD->getCachedLinkage());
  else if (NamedDecl *ND = dyn_cast<NamedDecl>(FromD))
    ToD->setCachedLinkage(ND->getLinkageInternal());
  
  if (TagDecl *FromTag = dyn_cast<TagDecl>(FromD)) {
    // Keep track of anonymous tags that have an associated typedef.
    if (FromTag->getTypedefNameForAnonDecl())
      AnonTagsWithPendingTypedefs.push_back(FromTag);
  } else if (TypedefNameDecl *FromTypedef = dyn_cast<TypedefNameDecl>(FromD)) {
    // When we've finished transforming a typedef, see whether it was the
    // typedef for an anonymous tag.
    for (SmallVectorImpl<TagDecl *>::iterator
               FromTag = AnonTagsWithPendingTypedefs.begin(), 
            FromTagEnd = AnonTagsWithPendingTypedefs.end();
         FromTag != FromTagEnd; ++FromTag) {
      if ((*FromTag)->getTypedefNameForAnonDecl() == FromTypedef) {
        if (TagDecl *ToTag = cast_or_null<TagDecl>(Import(*FromTag))) {
          // We found the typedef for an anonymous tag; link them.
          ToTag->setTypedefNameForAnonDecl(cast<TypedefNameDecl>(ToD));
          AnonTagsWithPendingTypedefs.erase(FromTag);
          break;
        }
      }
    }
  }

  return ToD;
}

DeclContext *ASTImporter::ImportContext(DeclContext *FromDC) {
  if (!FromDC)
    return FromDC;

  DeclContext *ToDC = cast_or_null<DeclContext>(Import(cast<Decl>(FromDC)));
  if (!ToDC)
    return 0;
  
  // When we're using a record/enum/Objective-C class/protocol as a context, we 
  // need it to have a definition.
  if (RecordDecl *ToRecord = dyn_cast<RecordDecl>(ToDC)) {
    RecordDecl *FromRecord = cast<RecordDecl>(FromDC);
    if (ToRecord->isCompleteDefinition()) {
      // Do nothing.
    } else if (FromRecord->isCompleteDefinition()) {
      ASTNodeImporter(*this).ImportDefinition(FromRecord, ToRecord,
                                              ASTNodeImporter::IDK_Basic);
    } else {
      CompleteDecl(ToRecord);
    }
  } else if (EnumDecl *ToEnum = dyn_cast<EnumDecl>(ToDC)) {
    EnumDecl *FromEnum = cast<EnumDecl>(FromDC);
    if (ToEnum->isCompleteDefinition()) {
      // Do nothing.
    } else if (FromEnum->isCompleteDefinition()) {
      ASTNodeImporter(*this).ImportDefinition(FromEnum, ToEnum,
                                              ASTNodeImporter::IDK_Basic);
    } else {
      CompleteDecl(ToEnum);
    }    
  } else if (ObjCInterfaceDecl *ToClass = dyn_cast<ObjCInterfaceDecl>(ToDC)) {
    ObjCInterfaceDecl *FromClass = cast<ObjCInterfaceDecl>(FromDC);
    if (ToClass->getDefinition()) {
      // Do nothing.
    } else if (ObjCInterfaceDecl *FromDef = FromClass->getDefinition()) {
      ASTNodeImporter(*this).ImportDefinition(FromDef, ToClass,
                                              ASTNodeImporter::IDK_Basic);
    } else {
      CompleteDecl(ToClass);
    }
  } else if (ObjCProtocolDecl *ToProto = dyn_cast<ObjCProtocolDecl>(ToDC)) {
    ObjCProtocolDecl *FromProto = cast<ObjCProtocolDecl>(FromDC);
    if (ToProto->getDefinition()) {
      // Do nothing.
    } else if (ObjCProtocolDecl *FromDef = FromProto->getDefinition()) {
      ASTNodeImporter(*this).ImportDefinition(FromDef, ToProto,
                                              ASTNodeImporter::IDK_Basic);
    } else {
      CompleteDecl(ToProto);
    }    
  }
  
  return ToDC;
}

Expr *ASTImporter::Import(Expr *FromE) {
  if (!FromE)
    return 0;

  return cast_or_null<Expr>(Import(cast<Stmt>(FromE)));
}

Stmt *ASTImporter::Import(Stmt *FromS) {
  if (!FromS)
    return 0;

  // Check whether we've already imported this declaration.  
  llvm::DenseMap<Stmt *, Stmt *>::iterator Pos = ImportedStmts.find(FromS);
  if (Pos != ImportedStmts.end())
    return Pos->second;
  
  // Import the type
  ASTNodeImporter Importer(*this);
  Stmt *ToS = Importer.Visit(FromS);
  if (!ToS)
    return 0;
  
  // Record the imported declaration.
  ImportedStmts[FromS] = ToS;
  return ToS;
}

NestedNameSpecifier *ASTImporter::Import(NestedNameSpecifier *FromNNS) {
  if (!FromNNS)
    return 0;

  NestedNameSpecifier *prefix = Import(FromNNS->getPrefix());

  switch (FromNNS->getKind()) {
  case NestedNameSpecifier::Identifier:
    if (IdentifierInfo *II = Import(FromNNS->getAsIdentifier())) {
      return NestedNameSpecifier::Create(ToContext, prefix, II);
    }
    assert(false);
    return 0;

  case NestedNameSpecifier::Namespace:
    if (NamespaceDecl *NS = 
          cast<NamespaceDecl>(Import(FromNNS->getAsNamespace()))) {
      return NestedNameSpecifier::Create(ToContext, prefix, NS);
    }
    assert(false);
    return 0;

  case NestedNameSpecifier::NamespaceAlias:
    if (NamespaceAliasDecl *NSAD = 
          cast<NamespaceAliasDecl>(Import(FromNNS->getAsNamespaceAlias()))) {
      return NestedNameSpecifier::Create(ToContext, prefix, NSAD);
    }
    assert(false);
    return 0;

  case NestedNameSpecifier::Global:
    return NestedNameSpecifier::GlobalSpecifier(ToContext);

  case NestedNameSpecifier::TypeSpec:
  case NestedNameSpecifier::TypeSpecWithTemplate: {
      QualType T = Import(QualType(FromNNS->getAsType(), 0u));
      if (!T.isNull()) {
        bool bTemplate = FromNNS->getKind() == 
                         NestedNameSpecifier::TypeSpecWithTemplate;
        return NestedNameSpecifier::Create(ToContext, prefix, 
                                           bTemplate, T.getTypePtr());
      }
    }
    assert(false);
    return 0;
  }

  llvm_unreachable("Invalid nested name specifier kind");
}

NestedNameSpecifierLoc ASTImporter::Import(NestedNameSpecifierLoc FromNNS) {
  // Copied from NestedNameSpecifier mostly.
  SmallVector<NestedNameSpecifierLoc , 8> NestedNames;
  NestedNameSpecifierLoc NNS = FromNNS;

  // Push each of the nested-name-specifiers's onto a stack for
  // serialization in reverse order.
  while (NNS) {
    NestedNames.push_back(NNS);
    NNS = NNS.getPrefix();
  }
  // FIXME: check if this list is inverted

  NestedNameSpecifierLocBuilder Builder;

  while(!NestedNames.empty()) {
    NNS = NestedNames.pop_back_val();
    NestedNameSpecifier *Spec = Import(NNS.getNestedNameSpecifier());
    NestedNameSpecifier::SpecifierKind Kind = Spec->getKind();
    switch (Kind) {
    case NestedNameSpecifier::Identifier:
      Builder.Extend(getToContext(),
                     Spec->getAsIdentifier(),
                     Import(NNS.getLocalBeginLoc()),
                     Import(NNS.getLocalEndLoc()));
      break;

    case NestedNameSpecifier::Namespace:
      Builder.Extend(getToContext(),
                     Spec->getAsNamespace(),
                     Import(NNS.getLocalBeginLoc()),
                     Import(NNS.getLocalEndLoc()));
      break;

    case NestedNameSpecifier::NamespaceAlias:
      Builder.Extend(getToContext(),
                     Spec->getAsNamespaceAlias(),
                     Import(NNS.getLocalBeginLoc()),
                     Import(NNS.getLocalEndLoc()));
      break;

    case NestedNameSpecifier::TypeSpec:
    case NestedNameSpecifier::TypeSpecWithTemplate: {
      TypeSourceInfo *TSI = getToContext().getTrivialTypeSourceInfo(
            QualType(Spec->getAsType() ,0));
      Builder.Extend(getToContext(),
                     // FIXME: Is 'Data' serialization good?
                     Import(NNS.getLocalBeginLoc()),
                     TSI->getTypeLoc(),
                     Import(NNS.getLocalEndLoc()));
      break;
    }

    case NestedNameSpecifier::Global:
      Builder.MakeGlobal(getToContext(), Import(NNS.getLocalBeginLoc()));
      break;
    }
  }

  return Builder.getWithLocInContext(getToContext());
}

TemplateName ASTImporter::Import(TemplateName From) {
  switch (From.getKind()) {
  case TemplateName::Template:
    if (TemplateDecl *ToTemplate
                = cast_or_null<TemplateDecl>(Import(From.getAsTemplateDecl())))
      return TemplateName(ToTemplate);
      
    return TemplateName();
      
  case TemplateName::OverloadedTemplate: {
    OverloadedTemplateStorage *FromStorage = From.getAsOverloadedTemplate();
    UnresolvedSet<2> ToTemplates;
    for (OverloadedTemplateStorage::iterator I = FromStorage->begin(),
                                             E = FromStorage->end();
         I != E; ++I) {
      if (NamedDecl *To = cast_or_null<NamedDecl>(Import(*I))) 
        ToTemplates.addDecl(To);
      else
        return TemplateName();
    }
    return ToContext.getOverloadedTemplateName(ToTemplates.begin(), 
                                               ToTemplates.end());
  }
      
  case TemplateName::QualifiedTemplate: {
    QualifiedTemplateName *QTN = From.getAsQualifiedTemplateName();
    NestedNameSpecifier *Qualifier = Import(QTN->getQualifier());
    if (!Qualifier)
      return TemplateName();
    
    if (TemplateDecl *ToTemplate
        = cast_or_null<TemplateDecl>(Import(From.getAsTemplateDecl())))
      return ToContext.getQualifiedTemplateName(Qualifier, 
                                                QTN->hasTemplateKeyword(), 
                                                ToTemplate);
    
    return TemplateName();
  }
  
  case TemplateName::DependentTemplate: {
    DependentTemplateName *DTN = From.getAsDependentTemplateName();
    NestedNameSpecifier *Qualifier = Import(DTN->getQualifier());
    if (!Qualifier)
      return TemplateName();
    
    if (DTN->isIdentifier()) {
      return ToContext.getDependentTemplateName(Qualifier, 
                                                Import(DTN->getIdentifier()));
    }
    
    return ToContext.getDependentTemplateName(Qualifier, DTN->getOperator());
  }

  case TemplateName::SubstTemplateTemplateParm: {
    SubstTemplateTemplateParmStorage *subst
      = From.getAsSubstTemplateTemplateParm();
    TemplateTemplateParmDecl *param
      = cast_or_null<TemplateTemplateParmDecl>(Import(subst->getParameter()));
    if (!param)
      return TemplateName();

    TemplateName replacement = Import(subst->getReplacement());
    if (replacement.isNull()) return TemplateName();
    
    return ToContext.getSubstTemplateTemplateParm(param, replacement);
  }
      
  case TemplateName::SubstTemplateTemplateParmPack: {
    SubstTemplateTemplateParmPackStorage *SubstPack
      = From.getAsSubstTemplateTemplateParmPack();
    TemplateTemplateParmDecl *Param
      = cast_or_null<TemplateTemplateParmDecl>(
                                        Import(SubstPack->getParameterPack()));
    if (!Param)
      return TemplateName();
    
    ASTNodeImporter Importer(*this);
    TemplateArgument ArgPack 
      = Importer.ImportTemplateArgument(SubstPack->getArgumentPack());
    if (ArgPack.isNull())
      return TemplateName();
    
    return ToContext.getSubstTemplateTemplateParmPack(Param, ArgPack);
  }
  }
  
  llvm_unreachable("Invalid template name kind");
}

SourceLocation ASTImporter::Import(SourceLocation FromLoc) {
  if (FromLoc.isInvalid())
    return SourceLocation();

  SourceManager &FromSM = FromContext.getSourceManager();
  
  // For now, map everything down to its spelling location, so that we
  // don't have to import macro expansions.
  // FIXME: Import macro expansions!
  std::pair<FileID, unsigned> Decomposed = FromSM.getDecomposedExpansionLoc(FromLoc);
  SourceManager &ToSM = ToContext.getSourceManager();
  FileID ToFileID = Import(Decomposed.first);
  if (ToFileID.isInvalid())
    return SourceLocation();
  return ToSM.getLocForStartOfFile(ToFileID)
             .getLocWithOffset(Decomposed.second);
}

SourceRange ASTImporter::Import(SourceRange FromRange) {
  return SourceRange(Import(FromRange.getBegin()), Import(FromRange.getEnd()));
}

FileID ASTImporter::Import(FileID FromID) {
  llvm::DenseMap<FileID, FileID>::iterator Pos
    = ImportedFileIDs.find(FromID);
  if (Pos != ImportedFileIDs.end())
    return Pos->second;
  
  SourceManager &FromSM = FromContext.getSourceManager();
  SourceManager &ToSM = ToContext.getSourceManager();
  const SrcMgr::SLocEntry &FromSLoc = FromSM.getSLocEntry(FromID);
  assert(FromSLoc.isFile() && "Cannot handle macro expansions yet");
  
  // Include location of this file.
  SourceLocation ToIncludeLoc = Import(FromSLoc.getFile().getIncludeLoc());
  
  // Map the FileID for to the "to" source manager.
  FileID ToID;
  const SrcMgr::ContentCache *Cache = FromSLoc.getFile().getContentCache();
  if (Cache->OrigEntry) {
    // FIXME: We probably want to use getVirtualFile(), so we don't hit the
    // disk again
    // FIXME: We definitely want to re-use the existing MemoryBuffer, rather
    // than mmap the files several times.
    const FileEntry *Entry = ToFileManager.getFile(Cache->OrigEntry->getName());
    if (!Entry)
      return FileID();
    ToID = ToSM.createFileID(Entry, ToIncludeLoc, 
                             FromSLoc.getFile().getFileCharacteristic());
  } else {
    // FIXME: We want to re-use the existing MemoryBuffer!
    const llvm::MemoryBuffer *
        FromBuf = Cache->getBuffer(FromContext.getDiagnostics(), FromSM);
    llvm::MemoryBuffer *ToBuf
      = llvm::MemoryBuffer::getMemBufferCopy(FromBuf->getBuffer(),
                                             FromBuf->getBufferIdentifier());
    ToID = ToSM.createFileIDForMemBuffer(ToBuf,
                                    FromSLoc.getFile().getFileCharacteristic());
  }
  
  
  ImportedFileIDs[FromID] = ToID;
  return ToID;
}

CXXBaseSpecifier *ASTImporter::Import(const CXXBaseSpecifier *BaseSpec) {
  ImportedCXXBaseSpecifierMap::const_iterator Pos =
      ImportedCXXBaseSpecifiers.find(BaseSpec);
  if (Pos != ImportedCXXBaseSpecifiers.end())
    return Pos->second;

  CXXBaseSpecifier *Imported = new (ToContext) CXXBaseSpecifier(
        Import(BaseSpec->getSourceRange()),
        BaseSpec->isVirtual(), BaseSpec->isBaseOfClass(),
        BaseSpec->getAccessSpecifierAsWritten(),
        Import(BaseSpec->getTypeSourceInfo()),
        Import(BaseSpec->getEllipsisLoc()));
  ImportedCXXBaseSpecifiers[BaseSpec] = Imported;
  return Imported;
}

void ASTImporter::ImportDefinition(Decl *From) {
  Decl *To = Import(From);
  if (!To)
    return;
  
  if (DeclContext *FromDC = cast<DeclContext>(From)) {
    ASTNodeImporter Importer(*this);
      
    if (RecordDecl *ToRecord = dyn_cast<RecordDecl>(To)) {
      if (!ToRecord->getDefinition()) {
        Importer.ImportDefinition(cast<RecordDecl>(FromDC), ToRecord, 
                                  ASTNodeImporter::IDK_Everything);
        return;
      }      
    }

    if (EnumDecl *ToEnum = dyn_cast<EnumDecl>(To)) {
      if (!ToEnum->getDefinition()) {
        Importer.ImportDefinition(cast<EnumDecl>(FromDC), ToEnum, 
                                  ASTNodeImporter::IDK_Everything);
        return;
      }      
    }
    
    if (ObjCInterfaceDecl *ToIFace = dyn_cast<ObjCInterfaceDecl>(To)) {
      if (!ToIFace->getDefinition()) {
        Importer.ImportDefinition(cast<ObjCInterfaceDecl>(FromDC), ToIFace,
                                  ASTNodeImporter::IDK_Everything);
        return;
      }
    }

    if (ObjCProtocolDecl *ToProto = dyn_cast<ObjCProtocolDecl>(To)) {
      if (!ToProto->getDefinition()) {
        Importer.ImportDefinition(cast<ObjCProtocolDecl>(FromDC), ToProto,
                                  ASTNodeImporter::IDK_Everything);
        return;
      }
    }
    
    Importer.ImportDeclContext(FromDC, true);
  }
}

DeclarationName ASTImporter::Import(DeclarationName FromName) {
  if (!FromName)
    return DeclarationName();

  switch (FromName.getNameKind()) {
  case DeclarationName::Identifier:
    return Import(FromName.getAsIdentifierInfo());

  case DeclarationName::ObjCZeroArgSelector:
  case DeclarationName::ObjCOneArgSelector:
  case DeclarationName::ObjCMultiArgSelector:
    return Import(FromName.getObjCSelector());

  case DeclarationName::CXXConstructorName: {
    QualType T = Import(FromName.getCXXNameType());
    if (T.isNull())
      return DeclarationName();

    return ToContext.DeclarationNames.getCXXConstructorName(
                                               ToContext.getCanonicalType(T));
  }

  case DeclarationName::CXXDestructorName: {
    QualType T = Import(FromName.getCXXNameType());
    if (T.isNull())
      return DeclarationName();

    return ToContext.DeclarationNames.getCXXDestructorName(
                                               ToContext.getCanonicalType(T));
  }

  case DeclarationName::CXXConversionFunctionName: {
    QualType T = Import(FromName.getCXXNameType());
    if (T.isNull())
      return DeclarationName();

    return ToContext.DeclarationNames.getCXXConversionFunctionName(
                                               ToContext.getCanonicalType(T));
  }

  case DeclarationName::CXXOperatorName:
    return ToContext.DeclarationNames.getCXXOperatorName(
                                          FromName.getCXXOverloadedOperator());

  case DeclarationName::CXXLiteralOperatorName:
    return ToContext.DeclarationNames.getCXXLiteralOperatorName(
                                   Import(FromName.getCXXLiteralIdentifier()));

  case DeclarationName::CXXUsingDirective:
    // FIXME: STATICS!
    return DeclarationName::getUsingDirectiveName();
  }

  llvm_unreachable("Invalid DeclarationName Kind!");
}

IdentifierInfo *ASTImporter::Import(const IdentifierInfo *FromId) {
  if (!FromId)
    return 0;

  return &ToContext.Idents.get(FromId->getName());
}

Selector ASTImporter::Import(Selector FromSel) {
  if (FromSel.isNull())
    return Selector();

  SmallVector<IdentifierInfo *, 4> Idents;
  Idents.push_back(Import(FromSel.getIdentifierInfoForSlot(0)));
  for (unsigned I = 1, N = FromSel.getNumArgs(); I < N; ++I)
    Idents.push_back(Import(FromSel.getIdentifierInfoForSlot(I)));
  return ToContext.Selectors.getSelector(FromSel.getNumArgs(), Idents.data());
}

DeclarationName ASTImporter::HandleNameConflict(DeclarationName Name,
                                                DeclContext *DC,
                                                unsigned IDNS,
                                                NamedDecl **Decls,
                                                unsigned NumDecls) {
  return Name;
}

DiagnosticBuilder ASTImporter::ToDiag(SourceLocation Loc, unsigned DiagID) {
  if (LastDiagFromFrom)
    ToContext.getDiagnostics().notePriorDiagnosticFrom(
      FromContext.getDiagnostics());
  LastDiagFromFrom = false;
  return ToContext.getDiagnostics().Report(Loc, DiagID);
}

DiagnosticBuilder ASTImporter::FromDiag(SourceLocation Loc, unsigned DiagID) {
  if (!LastDiagFromFrom)
    FromContext.getDiagnostics().notePriorDiagnosticFrom(
      ToContext.getDiagnostics());
  LastDiagFromFrom = true;
  return FromContext.getDiagnostics().Report(Loc, DiagID);
}

void ASTImporter::CompleteDecl (Decl *D) {
  if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D)) {
    if (!ID->getDefinition())
      ID->startDefinition();
  }
  else if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D)) {
    if (!PD->getDefinition())
      PD->startDefinition();
  }
  else if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
    if (!TD->getDefinition() && !TD->isBeingDefined()) {
      TD->startDefinition();
      TD->setCompleteDefinition(true);
    }
  }
  else {
    assert (0 && "CompleteDecl called on a Decl that can't be completed");
  }
}

Decl *ASTImporter::Imported(Decl *From, Decl *To) {
  ImportedDecls[From] = To;
  return To;
}

bool ASTImporter::IsStructurallyEquivalent(QualType From, QualType To,
                                           bool Complain, bool CheckQualifiers) {
  llvm::DenseMap<const Type *, const Type *>::iterator Pos
   = ImportedTypes.find(From.getTypePtr());
  if (Pos != ImportedTypes.end() && ToContext.hasSameType(Import(From), To))
    return true;
      
  StructuralEquivalenceContext Ctx(FromContext, ToContext, NonEquivalentDecls,
                                   false, Complain);
  return Ctx.IsStructurallyEquivalent(From, To, CheckQualifiers);
}