granicus.if.org Git - clang/blob - lib/AST/ASTImporter.cpp

   1 //===--- ASTImporter.cpp - Importing ASTs from other Contexts ---*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 //  This file defines the ASTImporter class which imports AST nodes from one
  11 //  context into another context.
  12 //
  13 //===----------------------------------------------------------------------===//
  14 #include "clang/AST/ASTImporter.h"
  15 #include "clang/AST/ASTContext.h"
  16 #include "clang/AST/ASTDiagnostic.h"
  17 #include "clang/AST/DeclCXX.h"
  18 #include "clang/AST/DeclObjC.h"
  19 #include "clang/AST/DeclVisitor.h"
  20 #include "clang/AST/StmtVisitor.h"
  21 #include "clang/AST/TypeVisitor.h"
  22 #include "clang/Basic/FileManager.h"
  23 #include "clang/Basic/SourceManager.h"
  24 #include "llvm/Support/MemoryBuffer.h"
  25 #include <deque>
  26
  27 namespace clang {
  28   class ASTNodeImporter : public TypeVisitor<ASTNodeImporter, QualType>,
  29                           public DeclVisitor<ASTNodeImporter, Decl *>,
  30                           public StmtVisitor<ASTNodeImporter, Stmt *> {
  31     ASTImporter &Importer;
  32
  33   public:
  34     explicit ASTNodeImporter(ASTImporter &Importer) : Importer(Importer) { }
  35
  36     using TypeVisitor<ASTNodeImporter, QualType>::Visit;
  37     using DeclVisitor<ASTNodeImporter, Decl *>::Visit;
  38     using StmtVisitor<ASTNodeImporter, Stmt *>::Visit;
  39
  40     // Importing types
  41     QualType VisitType(const Type *T);
  42     QualType VisitBuiltinType(const BuiltinType *T);
  43     QualType VisitComplexType(const ComplexType *T);
  44     QualType VisitPointerType(const PointerType *T);
  45     QualType VisitBlockPointerType(const BlockPointerType *T);
  46     QualType VisitLValueReferenceType(const LValueReferenceType *T);
  47     QualType VisitRValueReferenceType(const RValueReferenceType *T);
  48     QualType VisitMemberPointerType(const MemberPointerType *T);
  49     QualType VisitConstantArrayType(const ConstantArrayType *T);
  50     QualType VisitIncompleteArrayType(const IncompleteArrayType *T);
  51     QualType VisitVariableArrayType(const VariableArrayType *T);
  52     // FIXME: DependentSizedArrayType
  53     // FIXME: DependentSizedExtVectorType
  54     QualType VisitVectorType(const VectorType *T);
  55     QualType VisitExtVectorType(const ExtVectorType *T);
  56     QualType VisitFunctionNoProtoType(const FunctionNoProtoType *T);
  57     QualType VisitFunctionProtoType(const FunctionProtoType *T);
  58     // FIXME: UnresolvedUsingType
  59     QualType VisitParenType(const ParenType *T);
  60     QualType VisitTypedefType(const TypedefType *T);
  61     QualType VisitTypeOfExprType(const TypeOfExprType *T);
  62     // FIXME: DependentTypeOfExprType
  63     QualType VisitTypeOfType(const TypeOfType *T);
  64     QualType VisitDecltypeType(const DecltypeType *T);
  65     QualType VisitUnaryTransformType(const UnaryTransformType *T);
  66     QualType VisitAutoType(const AutoType *T);
  67     QualType VisitInjectedClassNameType(const InjectedClassNameType *T);
  68     // FIXME: DependentDecltypeType
  69     QualType VisitRecordType(const RecordType *T);
  70     QualType VisitEnumType(const EnumType *T);
  71     QualType VisitAttributedType(const AttributedType *T);
  72     QualType VisitTemplateTypeParmType(const TemplateTypeParmType *T);
  73     // FIXME: SubstTemplateTypeParmType
  74     QualType VisitTemplateSpecializationType(const TemplateSpecializationType *T);
  75     QualType VisitElaboratedType(const ElaboratedType *T);
  76     // FIXME: DependentNameType
  77     // FIXME: DependentTemplateSpecializationType
  78     QualType VisitObjCInterfaceType(const ObjCInterfaceType *T);
  79     QualType VisitObjCObjectType(const ObjCObjectType *T);
  80     QualType VisitObjCObjectPointerType(const ObjCObjectPointerType *T);
  81
  82     // Importing declarations
  83     bool ImportDeclParts(NamedDecl *D, DeclContext *&DC,
  84                          DeclContext *&LexicalDC, DeclarationName &Name,
  85                          NamedDecl *&ToD, SourceLocation &Loc);
  86     void ImportDefinitionIfNeeded(Decl *FromD, Decl *ToD = nullptr);
  87     void ImportDeclarationNameLoc(const DeclarationNameInfo &From,
  88                                   DeclarationNameInfo& To);
  89     void ImportDeclContext(DeclContext *FromDC, bool ForceImport = false);
  90
  91     typedef DesignatedInitExpr::Designator Designator;
  92     Designator ImportDesignator(const Designator &D);
  93
  94
  95     /// \brief What we should import from the definition.
  96     enum ImportDefinitionKind {
  97       /// \brief Import the default subset of the definition, which might be
  98       /// nothing (if minimal import is set) or might be everything (if minimal
  99       /// import is not set).
 100       IDK_Default,
 101       /// \brief Import everything.
 102       IDK_Everything,
 103       /// \brief Import only the bare bones needed to establish a valid
 104       /// DeclContext.
 105       IDK_Basic
 106     };
 107
 108     bool shouldForceImportDeclContext(ImportDefinitionKind IDK) {
 109       return IDK == IDK_Everything ||
 110              (IDK == IDK_Default && !Importer.isMinimalImport());
 111     }
 112
 113     bool ImportDefinition(RecordDecl *From, RecordDecl *To,
 114                           ImportDefinitionKind Kind = IDK_Default);
 115     bool ImportDefinition(VarDecl *From, VarDecl *To,
 116                           ImportDefinitionKind Kind = IDK_Default);
 117     bool ImportDefinition(EnumDecl *From, EnumDecl *To,
 118                           ImportDefinitionKind Kind = IDK_Default);
 119     bool ImportDefinition(ObjCInterfaceDecl *From, ObjCInterfaceDecl *To,
 120                           ImportDefinitionKind Kind = IDK_Default);
 121     bool ImportDefinition(ObjCProtocolDecl *From, ObjCProtocolDecl *To,
 122                           ImportDefinitionKind Kind = IDK_Default);
 123     TemplateParameterList *ImportTemplateParameterList(
 124                                                  TemplateParameterList *Params);
 125     TemplateArgument ImportTemplateArgument(const TemplateArgument &From);
 126     bool ImportTemplateArguments(const TemplateArgument *FromArgs,
 127                                  unsigned NumFromArgs,
 128                                SmallVectorImpl<TemplateArgument> &ToArgs);
 129     bool IsStructuralMatch(RecordDecl *FromRecord, RecordDecl *ToRecord,
 130                            bool Complain = true);
 131     bool IsStructuralMatch(VarDecl *FromVar, VarDecl *ToVar,
 132                            bool Complain = true);
 133     bool IsStructuralMatch(EnumDecl *FromEnum, EnumDecl *ToRecord);
 134     bool IsStructuralMatch(EnumConstantDecl *FromEC, EnumConstantDecl *ToEC);
 135     bool IsStructuralMatch(ClassTemplateDecl *From, ClassTemplateDecl *To);
 136     bool IsStructuralMatch(VarTemplateDecl *From, VarTemplateDecl *To);
 137     Decl *VisitDecl(Decl *D);
 138     Decl *VisitAccessSpecDecl(AccessSpecDecl *D);
 139     Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
 140     Decl *VisitNamespaceDecl(NamespaceDecl *D);
 141     Decl *VisitTypedefNameDecl(TypedefNameDecl *D, bool IsAlias);
 142     Decl *VisitTypedefDecl(TypedefDecl *D);
 143     Decl *VisitTypeAliasDecl(TypeAliasDecl *D);
 144     Decl *VisitLabelDecl(LabelDecl *D);
 145     Decl *VisitEnumDecl(EnumDecl *D);
 146     Decl *VisitRecordDecl(RecordDecl *D);
 147     Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
 148     Decl *VisitFunctionDecl(FunctionDecl *D);
 149     Decl *VisitCXXMethodDecl(CXXMethodDecl *D);
 150     Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
 151     Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
 152     Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
 153     Decl *VisitFieldDecl(FieldDecl *D);
 154     Decl *VisitIndirectFieldDecl(IndirectFieldDecl *D);
 155     Decl *VisitObjCIvarDecl(ObjCIvarDecl *D);
 156     Decl *VisitVarDecl(VarDecl *D);
 157     Decl *VisitImplicitParamDecl(ImplicitParamDecl *D);
 158     Decl *VisitParmVarDecl(ParmVarDecl *D);
 159     Decl *VisitObjCMethodDecl(ObjCMethodDecl *D);
 160     Decl *VisitObjCTypeParamDecl(ObjCTypeParamDecl *D);
 161     Decl *VisitObjCCategoryDecl(ObjCCategoryDecl *D);
 162     Decl *VisitObjCProtocolDecl(ObjCProtocolDecl *D);
 163     Decl *VisitLinkageSpecDecl(LinkageSpecDecl *D);
 164
 165     ObjCTypeParamList *ImportObjCTypeParamList(ObjCTypeParamList *list);
 166     Decl *VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
 167     Decl *VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D);
 168     Decl *VisitObjCImplementationDecl(ObjCImplementationDecl *D);
 169     Decl *VisitObjCPropertyDecl(ObjCPropertyDecl *D);
 170     Decl *VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
 171     Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
 172     Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
 173     Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
 174     Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
 175     Decl *VisitClassTemplateSpecializationDecl(
 176                                             ClassTemplateSpecializationDecl *D);
 177     Decl *VisitVarTemplateDecl(VarTemplateDecl *D);
 178     Decl *VisitVarTemplateSpecializationDecl(VarTemplateSpecializationDecl *D);
 179
 180     // Importing statements
 181     DeclGroupRef ImportDeclGroup(DeclGroupRef DG);
 182
 183     Stmt *VisitStmt(Stmt *S);
 184     Stmt *VisitGCCAsmStmt(GCCAsmStmt *S);
 185     Stmt *VisitDeclStmt(DeclStmt *S);
 186     Stmt *VisitNullStmt(NullStmt *S);
 187     Stmt *VisitCompoundStmt(CompoundStmt *S);
 188     Stmt *VisitCaseStmt(CaseStmt *S);
 189     Stmt *VisitDefaultStmt(DefaultStmt *S);
 190     Stmt *VisitLabelStmt(LabelStmt *S);
 191     Stmt *VisitAttributedStmt(AttributedStmt *S);
 192     Stmt *VisitIfStmt(IfStmt *S);
 193     Stmt *VisitSwitchStmt(SwitchStmt *S);
 194     Stmt *VisitWhileStmt(WhileStmt *S);
 195     Stmt *VisitDoStmt(DoStmt *S);
 196     Stmt *VisitForStmt(ForStmt *S);
 197     Stmt *VisitGotoStmt(GotoStmt *S);
 198     Stmt *VisitIndirectGotoStmt(IndirectGotoStmt *S);
 199     Stmt *VisitContinueStmt(ContinueStmt *S);
 200     Stmt *VisitBreakStmt(BreakStmt *S);
 201     Stmt *VisitReturnStmt(ReturnStmt *S);
 202     // FIXME: MSAsmStmt
 203     // FIXME: SEHExceptStmt
 204     // FIXME: SEHFinallyStmt
 205     // FIXME: SEHTryStmt
 206     // FIXME: SEHLeaveStmt
 207     // FIXME: CapturedStmt
 208     Stmt *VisitCXXCatchStmt(CXXCatchStmt *S);
 209     Stmt *VisitCXXTryStmt(CXXTryStmt *S);
 210     Stmt *VisitCXXForRangeStmt(CXXForRangeStmt *S);
 211     // FIXME: MSDependentExistsStmt
 212     Stmt *VisitObjCForCollectionStmt(ObjCForCollectionStmt *S);
 213     Stmt *VisitObjCAtCatchStmt(ObjCAtCatchStmt *S);
 214     Stmt *VisitObjCAtFinallyStmt(ObjCAtFinallyStmt *S);
 215     Stmt *VisitObjCAtTryStmt(ObjCAtTryStmt *S);
 216     Stmt *VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S);
 217     Stmt *VisitObjCAtThrowStmt(ObjCAtThrowStmt *S);
 218     Stmt *VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S);
 219
 220     // Importing expressions
 221     Expr *VisitExpr(Expr *E);
 222     Expr *VisitVAArgExpr(VAArgExpr *E);
 223     Expr *VisitGNUNullExpr(GNUNullExpr *E);
 224     Expr *VisitPredefinedExpr(PredefinedExpr *E);
 225     Expr *VisitDeclRefExpr(DeclRefExpr *E);
 226     Expr *VisitImplicitValueInitExpr(ImplicitValueInitExpr *ILE);
 227     Expr *VisitDesignatedInitExpr(DesignatedInitExpr *E);
 228     Expr *VisitCXXNullPtrLiteralExpr(CXXNullPtrLiteralExpr *E);
 229     Expr *VisitIntegerLiteral(IntegerLiteral *E);
 230     Expr *VisitFloatingLiteral(FloatingLiteral *E);
 231     Expr *VisitCharacterLiteral(CharacterLiteral *E);
 232     Expr *VisitStringLiteral(StringLiteral *E);
 233     Expr *VisitCompoundLiteralExpr(CompoundLiteralExpr *E);
 234     Expr *VisitAtomicExpr(AtomicExpr *E);
 235     Expr *VisitAddrLabelExpr(AddrLabelExpr *E);
 236     Expr *VisitParenExpr(ParenExpr *E);
 237     Expr *VisitParenListExpr(ParenListExpr *E);
 238     Expr *VisitStmtExpr(StmtExpr *E);
 239     Expr *VisitUnaryOperator(UnaryOperator *E);
 240     Expr *VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E);
 241     Expr *VisitBinaryOperator(BinaryOperator *E);
 242     Expr *VisitConditionalOperator(ConditionalOperator *E);
 243     Expr *VisitBinaryConditionalOperator(BinaryConditionalOperator *E);
 244     Expr *VisitOpaqueValueExpr(OpaqueValueExpr *E);
 245     Expr *VisitCompoundAssignOperator(CompoundAssignOperator *E);
 246     Expr *VisitImplicitCastExpr(ImplicitCastExpr *E);
 247     Expr *VisitCStyleCastExpr(CStyleCastExpr *E);
 248     Expr *VisitCXXConstructExpr(CXXConstructExpr *E);
 249     Expr *VisitCXXMemberCallExpr(CXXMemberCallExpr *E);
 250     Expr *VisitCXXThisExpr(CXXThisExpr *E);
 251     Expr *VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E);
 252     Expr *VisitMemberExpr(MemberExpr *E);
 253     Expr *VisitCallExpr(CallExpr *E);
 254     Expr *VisitInitListExpr(InitListExpr *E);
 255     Expr *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *E);
 256     Expr *VisitCXXNamedCastExpr(CXXNamedCastExpr *E);
 257
 258     template<typename IIter, typename OIter>
 259     void ImportArray(IIter Ibegin, IIter Iend, OIter Obegin) {
 260       typedef typename std::remove_reference<decltype(*Obegin)>::type ItemT;
 261       ASTImporter &ImporterRef = Importer;
 262       std::transform(Ibegin, Iend, Obegin,
 263                      [&ImporterRef](ItemT From) -> ItemT {
 264                        return ImporterRef.Import(From);
 265                      });
 266     }
 267
 268     template<typename IIter, typename OIter>
 269     bool ImportArrayChecked(IIter Ibegin, IIter Iend, OIter Obegin) {
 270       typedef typename std::remove_reference<decltype(**Obegin)>::type ItemT;
 271       ASTImporter &ImporterRef = Importer;
 272       bool Failed = false;
 273       std::transform(Ibegin, Iend, Obegin,
 274                      [&ImporterRef, &Failed](ItemT *From) -> ItemT * {
 275                        ItemT *To = ImporterRef.Import(From);
 276                        if (!To && From)
 277                          Failed = true;
 278                        return To;
 279                      });
 280       return Failed;
 281     }
 282   };
 283 }
 284
 285 using namespace clang;
 286
 287 //----------------------------------------------------------------------------
 288 // Structural Equivalence
 289 //----------------------------------------------------------------------------
 290
 291 namespace {
 292   struct StructuralEquivalenceContext {
 293     /// \brief AST contexts for which we are checking structural equivalence.
 294     ASTContext &C1, &C2;
 295
 296     /// \brief The set of "tentative" equivalences between two canonical
 297     /// declarations, mapping from a declaration in the first context to the
 298     /// declaration in the second context that we believe to be equivalent.
 299     llvm::DenseMap<Decl *, Decl *> TentativeEquivalences;
 300
 301     /// \brief Queue of declarations in the first context whose equivalence
 302     /// with a declaration in the second context still needs to be verified.
 303     std::deque<Decl *> DeclsToCheck;
 304
 305     /// \brief Declaration (from, to) pairs that are known not to be equivalent
 306     /// (which we have already complained about).
 307     llvm::DenseSet<std::pair<Decl *, Decl *> > &NonEquivalentDecls;
 308
 309     /// \brief Whether we're being strict about the spelling of types when
 310     /// unifying two types.
 311     bool StrictTypeSpelling;
 312
 313     /// \brief Whether to complain about failures.
 314     bool Complain;
 315
 316     /// \brief \c true if the last diagnostic came from C2.
 317     bool LastDiagFromC2;
 318
 319     StructuralEquivalenceContext(ASTContext &C1, ASTContext &C2,
 320                llvm::DenseSet<std::pair<Decl *, Decl *> > &NonEquivalentDecls,
 321                                  bool StrictTypeSpelling = false,
 322                                  bool Complain = true)
 323       : C1(C1), C2(C2), NonEquivalentDecls(NonEquivalentDecls),
 324         StrictTypeSpelling(StrictTypeSpelling), Complain(Complain),
 325         LastDiagFromC2(false) {}
 326
 327     /// \brief Determine whether the two declarations are structurally
 328     /// equivalent.
 329     bool IsStructurallyEquivalent(Decl *D1, Decl *D2);
 330
 331     /// \brief Determine whether the two types are structurally equivalent.
 332     bool IsStructurallyEquivalent(QualType T1, QualType T2);
 333
 334   private:
 335     /// \brief Finish checking all of the structural equivalences.
 336     ///
 337     /// \returns true if an error occurred, false otherwise.
 338     bool Finish();
 339
 340   public:
 341     DiagnosticBuilder Diag1(SourceLocation Loc, unsigned DiagID) {
 342       assert(Complain && "Not allowed to complain");
 343       if (LastDiagFromC2)
 344         C1.getDiagnostics().notePriorDiagnosticFrom(C2.getDiagnostics());
 345       LastDiagFromC2 = false;
 346       return C1.getDiagnostics().Report(Loc, DiagID);
 347     }
 348
 349     DiagnosticBuilder Diag2(SourceLocation Loc, unsigned DiagID) {
 350       assert(Complain && "Not allowed to complain");
 351       if (!LastDiagFromC2)
 352         C2.getDiagnostics().notePriorDiagnosticFrom(C1.getDiagnostics());
 353       LastDiagFromC2 = true;
 354       return C2.getDiagnostics().Report(Loc, DiagID);
 355     }
 356   };
 357 }
 358
 359 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
 360                                      QualType T1, QualType T2);
 361 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
 362                                      Decl *D1, Decl *D2);
 363
 364 /// \brief Determine structural equivalence of two expressions.
 365 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
 366                                      Expr *E1, Expr *E2) {
 367   if (!E1 || !E2)
 368     return E1 == E2;
 369
 370   // FIXME: Actually perform a structural comparison!
 371   return true;
 372 }
 373
 374 /// \brief Determine whether two identifiers are equivalent.
 375 static bool IsStructurallyEquivalent(const IdentifierInfo *Name1,
 376                                      const IdentifierInfo *Name2) {
 377   if (!Name1 || !Name2)
 378     return Name1 == Name2;
 379
 380   return Name1->getName() == Name2->getName();
 381 }
 382
 383 /// \brief Determine whether two nested-name-specifiers are equivalent.
 384 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
 385                                      NestedNameSpecifier *NNS1,
 386                                      NestedNameSpecifier *NNS2) {
 387   // FIXME: Implement!
 388   return true;
 389 }
 390
 391 /// \brief Determine whether two template arguments are equivalent.
 392 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
 393                                      const TemplateArgument &Arg1,
 394                                      const TemplateArgument &Arg2) {
 395   if (Arg1.getKind() != Arg2.getKind())
 396     return false;
 397
 398   switch (Arg1.getKind()) {
 399   case TemplateArgument::Null:
 400     return true;
 401
 402   case TemplateArgument::Type:
 403     return Context.IsStructurallyEquivalent(Arg1.getAsType(), Arg2.getAsType());
 404
 405   case TemplateArgument::Integral:
 406     if (!Context.IsStructurallyEquivalent(Arg1.getIntegralType(),
 407                                           Arg2.getIntegralType()))
 408       return false;
 409
 410     return llvm::APSInt::isSameValue(Arg1.getAsIntegral(), Arg2.getAsIntegral());
 411
 412   case TemplateArgument::Declaration:
 413     return Context.IsStructurallyEquivalent(Arg1.getAsDecl(), Arg2.getAsDecl());
 414
 415   case TemplateArgument::NullPtr:
 416     return true; // FIXME: Is this correct?
 417
 418   case TemplateArgument::Template:
 419     return IsStructurallyEquivalent(Context,
 420                                     Arg1.getAsTemplate(),
 421                                     Arg2.getAsTemplate());
 422
 423   case TemplateArgument::TemplateExpansion:
 424     return IsStructurallyEquivalent(Context,
 425                                     Arg1.getAsTemplateOrTemplatePattern(),
 426                                     Arg2.getAsTemplateOrTemplatePattern());
 427
 428   case TemplateArgument::Expression:
 429     return IsStructurallyEquivalent(Context,
 430                                     Arg1.getAsExpr(), Arg2.getAsExpr());
 431
 432   case TemplateArgument::Pack:
 433     if (Arg1.pack_size() != Arg2.pack_size())
 434       return false;
 435
 436     for (unsigned I = 0, N = Arg1.pack_size(); I != N; ++I)
 437       if (!IsStructurallyEquivalent(Context,
 438                                     Arg1.pack_begin()[I],
 439                                     Arg2.pack_begin()[I]))
 440         return false;
 441
 442     return true;
 443   }
 444
 445   llvm_unreachable("Invalid template argument kind");
 446 }
 447
 448 /// \brief Determine structural equivalence for the common part of array
 449 /// types.
 450 static bool IsArrayStructurallyEquivalent(StructuralEquivalenceContext &Context,
 451                                           const ArrayType *Array1,
 452                                           const ArrayType *Array2) {
 453   if (!IsStructurallyEquivalent(Context,
 454                                 Array1->getElementType(),
 455                                 Array2->getElementType()))
 456     return false;
 457   if (Array1->getSizeModifier() != Array2->getSizeModifier())
 458     return false;
 459   if (Array1->getIndexTypeQualifiers() != Array2->getIndexTypeQualifiers())
 460     return false;
 461
 462   return true;
 463 }
 464
 465 /// \brief Determine structural equivalence of two types.
 466 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
 467                                      QualType T1, QualType T2) {
 468   if (T1.isNull() || T2.isNull())
 469     return T1.isNull() && T2.isNull();
 470
 471   if (!Context.StrictTypeSpelling) {
 472     // We aren't being strict about token-to-token equivalence of types,
 473     // so map down to the canonical type.
 474     T1 = Context.C1.getCanonicalType(T1);
 475     T2 = Context.C2.getCanonicalType(T2);
 476   }
 477
 478   if (T1.getQualifiers() != T2.getQualifiers())
 479     return false;
 480
 481   Type::TypeClass TC = T1->getTypeClass();
 482
 483   if (T1->getTypeClass() != T2->getTypeClass()) {
 484     // Compare function types with prototypes vs. without prototypes as if
 485     // both did not have prototypes.
 486     if (T1->getTypeClass() == Type::FunctionProto &&
 487         T2->getTypeClass() == Type::FunctionNoProto)
 488       TC = Type::FunctionNoProto;
 489     else if (T1->getTypeClass() == Type::FunctionNoProto &&
 490              T2->getTypeClass() == Type::FunctionProto)
 491       TC = Type::FunctionNoProto;
 492     else
 493       return false;
 494   }
 495
 496   switch (TC) {
 497   case Type::Builtin:
 498     // FIXME: Deal with Char_S/Char_U.
 499     if (cast<BuiltinType>(T1)->getKind() != cast<BuiltinType>(T2)->getKind())
 500       return false;
 501     break;
 502
 503   case Type::Complex:
 504     if (!IsStructurallyEquivalent(Context,
 505                                   cast<ComplexType>(T1)->getElementType(),
 506                                   cast<ComplexType>(T2)->getElementType()))
 507       return false;
 508     break;
 509
 510   case Type::Adjusted:
 511   case Type::Decayed:
 512     if (!IsStructurallyEquivalent(Context,
 513                                   cast<AdjustedType>(T1)->getOriginalType(),
 514                                   cast<AdjustedType>(T2)->getOriginalType()))
 515       return false;
 516     break;
 517
 518   case Type::Pointer:
 519     if (!IsStructurallyEquivalent(Context,
 520                                   cast<PointerType>(T1)->getPointeeType(),
 521                                   cast<PointerType>(T2)->getPointeeType()))
 522       return false;
 523     break;
 524
 525   case Type::BlockPointer:
 526     if (!IsStructurallyEquivalent(Context,
 527                                   cast<BlockPointerType>(T1)->getPointeeType(),
 528                                   cast<BlockPointerType>(T2)->getPointeeType()))
 529       return false;
 530     break;
 531
 532   case Type::LValueReference:
 533   case Type::RValueReference: {
 534     const ReferenceType *Ref1 = cast<ReferenceType>(T1);
 535     const ReferenceType *Ref2 = cast<ReferenceType>(T2);
 536     if (Ref1->isSpelledAsLValue() != Ref2->isSpelledAsLValue())
 537       return false;
 538     if (Ref1->isInnerRef() != Ref2->isInnerRef())
 539       return false;
 540     if (!IsStructurallyEquivalent(Context,
 541                                   Ref1->getPointeeTypeAsWritten(),
 542                                   Ref2->getPointeeTypeAsWritten()))
 543       return false;
 544     break;
 545   }
 546
 547   case Type::MemberPointer: {
 548     const MemberPointerType *MemPtr1 = cast<MemberPointerType>(T1);
 549     const MemberPointerType *MemPtr2 = cast<MemberPointerType>(T2);
 550     if (!IsStructurallyEquivalent(Context,
 551                                   MemPtr1->getPointeeType(),
 552                                   MemPtr2->getPointeeType()))
 553       return false;
 554     if (!IsStructurallyEquivalent(Context,
 555                                   QualType(MemPtr1->getClass(), 0),
 556                                   QualType(MemPtr2->getClass(), 0)))
 557       return false;
 558     break;
 559   }
 560
 561   case Type::ConstantArray: {
 562     const ConstantArrayType *Array1 = cast<ConstantArrayType>(T1);
 563     const ConstantArrayType *Array2 = cast<ConstantArrayType>(T2);
 564     if (!llvm::APInt::isSameValue(Array1->getSize(), Array2->getSize()))
 565       return false;
 566
 567     if (!IsArrayStructurallyEquivalent(Context, Array1, Array2))
 568       return false;
 569     break;
 570   }
 571
 572   case Type::IncompleteArray:
 573     if (!IsArrayStructurallyEquivalent(Context,
 574                                        cast<ArrayType>(T1),
 575                                        cast<ArrayType>(T2)))
 576       return false;
 577     break;
 578
 579   case Type::VariableArray: {
 580     const VariableArrayType *Array1 = cast<VariableArrayType>(T1);
 581     const VariableArrayType *Array2 = cast<VariableArrayType>(T2);
 582     if (!IsStructurallyEquivalent(Context,
 583                                   Array1->getSizeExpr(), Array2->getSizeExpr()))
 584       return false;
 585
 586     if (!IsArrayStructurallyEquivalent(Context, Array1, Array2))
 587       return false;
 588
 589     break;
 590   }
 591
 592   case Type::DependentSizedArray: {
 593     const DependentSizedArrayType *Array1 = cast<DependentSizedArrayType>(T1);
 594     const DependentSizedArrayType *Array2 = cast<DependentSizedArrayType>(T2);
 595     if (!IsStructurallyEquivalent(Context,
 596                                   Array1->getSizeExpr(), Array2->getSizeExpr()))
 597       return false;
 598
 599     if (!IsArrayStructurallyEquivalent(Context, Array1, Array2))
 600       return false;
 601
 602     break;
 603   }
 604
 605   case Type::DependentSizedExtVector: {
 606     const DependentSizedExtVectorType *Vec1
 607       = cast<DependentSizedExtVectorType>(T1);
 608     const DependentSizedExtVectorType *Vec2
 609       = cast<DependentSizedExtVectorType>(T2);
 610     if (!IsStructurallyEquivalent(Context,
 611                                   Vec1->getSizeExpr(), Vec2->getSizeExpr()))
 612       return false;
 613     if (!IsStructurallyEquivalent(Context,
 614                                   Vec1->getElementType(),
 615                                   Vec2->getElementType()))
 616       return false;
 617     break;
 618   }
 619
 620   case Type::Vector:
 621   case Type::ExtVector: {
 622     const VectorType *Vec1 = cast<VectorType>(T1);
 623     const VectorType *Vec2 = cast<VectorType>(T2);
 624     if (!IsStructurallyEquivalent(Context,
 625                                   Vec1->getElementType(),
 626                                   Vec2->getElementType()))
 627       return false;
 628     if (Vec1->getNumElements() != Vec2->getNumElements())
 629       return false;
 630     if (Vec1->getVectorKind() != Vec2->getVectorKind())
 631       return false;
 632     break;
 633   }
 634
 635   case Type::FunctionProto: {
 636     const FunctionProtoType *Proto1 = cast<FunctionProtoType>(T1);
 637     const FunctionProtoType *Proto2 = cast<FunctionProtoType>(T2);
 638     if (Proto1->getNumParams() != Proto2->getNumParams())
 639       return false;
 640     for (unsigned I = 0, N = Proto1->getNumParams(); I != N; ++I) {
 641       if (!IsStructurallyEquivalent(Context, Proto1->getParamType(I),
 642                                     Proto2->getParamType(I)))
 643         return false;
 644     }
 645     if (Proto1->isVariadic() != Proto2->isVariadic())
 646       return false;
 647     if (Proto1->getExceptionSpecType() != Proto2->getExceptionSpecType())
 648       return false;
 649     if (Proto1->getExceptionSpecType() == EST_Dynamic) {
 650       if (Proto1->getNumExceptions() != Proto2->getNumExceptions())
 651         return false;
 652       for (unsigned I = 0, N = Proto1->getNumExceptions(); I != N; ++I) {
 653         if (!IsStructurallyEquivalent(Context,
 654                                       Proto1->getExceptionType(I),
 655                                       Proto2->getExceptionType(I)))
 656           return false;
 657       }
 658     } else if (Proto1->getExceptionSpecType() == EST_ComputedNoexcept) {
 659       if (!IsStructurallyEquivalent(Context,
 660                                     Proto1->getNoexceptExpr(),
 661                                     Proto2->getNoexceptExpr()))
 662         return false;
 663     }
 664     if (Proto1->getTypeQuals() != Proto2->getTypeQuals())
 665       return false;
 666
 667     // Fall through to check the bits common with FunctionNoProtoType.
 668   }
 669
 670   case Type::FunctionNoProto: {
 671     const FunctionType *Function1 = cast<FunctionType>(T1);
 672     const FunctionType *Function2 = cast<FunctionType>(T2);
 673     if (!IsStructurallyEquivalent(Context, Function1->getReturnType(),
 674                                   Function2->getReturnType()))
 675       return false;
 676     if (Function1->getExtInfo() != Function2->getExtInfo())
 677       return false;
 678     break;
 679   }
 680
 681   case Type::UnresolvedUsing:
 682     if (!IsStructurallyEquivalent(Context,
 683                                   cast<UnresolvedUsingType>(T1)->getDecl(),
 684                                   cast<UnresolvedUsingType>(T2)->getDecl()))
 685       return false;
 686
 687     break;
 688
 689   case Type::Attributed:
 690     if (!IsStructurallyEquivalent(Context,
 691                                   cast<AttributedType>(T1)->getModifiedType(),
 692                                   cast<AttributedType>(T2)->getModifiedType()))
 693       return false;
 694     if (!IsStructurallyEquivalent(Context,
 695                                 cast<AttributedType>(T1)->getEquivalentType(),
 696                                 cast<AttributedType>(T2)->getEquivalentType()))
 697       return false;
 698     break;
 699
 700   case Type::Paren:
 701     if (!IsStructurallyEquivalent(Context,
 702                                   cast<ParenType>(T1)->getInnerType(),
 703                                   cast<ParenType>(T2)->getInnerType()))
 704       return false;
 705     break;
 706
 707   case Type::Typedef:
 708     if (!IsStructurallyEquivalent(Context,
 709                                   cast<TypedefType>(T1)->getDecl(),
 710                                   cast<TypedefType>(T2)->getDecl()))
 711       return false;
 712     break;
 713
 714   case Type::TypeOfExpr:
 715     if (!IsStructurallyEquivalent(Context,
 716                                 cast<TypeOfExprType>(T1)->getUnderlyingExpr(),
 717                                 cast<TypeOfExprType>(T2)->getUnderlyingExpr()))
 718       return false;
 719     break;
 720
 721   case Type::TypeOf:
 722     if (!IsStructurallyEquivalent(Context,
 723                                   cast<TypeOfType>(T1)->getUnderlyingType(),
 724                                   cast<TypeOfType>(T2)->getUnderlyingType()))
 725       return false;
 726     break;
 727
 728   case Type::UnaryTransform:
 729     if (!IsStructurallyEquivalent(Context,
 730                              cast<UnaryTransformType>(T1)->getUnderlyingType(),
 731                              cast<UnaryTransformType>(T1)->getUnderlyingType()))
 732       return false;
 733     break;
 734
 735   case Type::Decltype:
 736     if (!IsStructurallyEquivalent(Context,
 737                                   cast<DecltypeType>(T1)->getUnderlyingExpr(),
 738                                   cast<DecltypeType>(T2)->getUnderlyingExpr()))
 739       return false;
 740     break;
 741
 742   case Type::Auto:
 743     if (!IsStructurallyEquivalent(Context,
 744                                   cast<AutoType>(T1)->getDeducedType(),
 745                                   cast<AutoType>(T2)->getDeducedType()))
 746       return false;
 747     break;
 748
 749   case Type::Record:
 750   case Type::Enum:
 751     if (!IsStructurallyEquivalent(Context,
 752                                   cast<TagType>(T1)->getDecl(),
 753                                   cast<TagType>(T2)->getDecl()))
 754       return false;
 755     break;
 756
 757   case Type::TemplateTypeParm: {
 758     const TemplateTypeParmType *Parm1 = cast<TemplateTypeParmType>(T1);
 759     const TemplateTypeParmType *Parm2 = cast<TemplateTypeParmType>(T2);
 760     if (Parm1->getDepth() != Parm2->getDepth())
 761       return false;
 762     if (Parm1->getIndex() != Parm2->getIndex())
 763       return false;
 764     if (Parm1->isParameterPack() != Parm2->isParameterPack())
 765       return false;
 766
 767     // Names of template type parameters are never significant.
 768     break;
 769   }
 770
 771   case Type::SubstTemplateTypeParm: {
 772     const SubstTemplateTypeParmType *Subst1
 773       = cast<SubstTemplateTypeParmType>(T1);
 774     const SubstTemplateTypeParmType *Subst2
 775       = cast<SubstTemplateTypeParmType>(T2);
 776     if (!IsStructurallyEquivalent(Context,
 777                                   QualType(Subst1->getReplacedParameter(), 0),
 778                                   QualType(Subst2->getReplacedParameter(), 0)))
 779       return false;
 780     if (!IsStructurallyEquivalent(Context,
 781                                   Subst1->getReplacementType(),
 782                                   Subst2->getReplacementType()))
 783       return false;
 784     break;
 785   }
 786
 787   case Type::SubstTemplateTypeParmPack: {
 788     const SubstTemplateTypeParmPackType *Subst1
 789       = cast<SubstTemplateTypeParmPackType>(T1);
 790     const SubstTemplateTypeParmPackType *Subst2
 791       = cast<SubstTemplateTypeParmPackType>(T2);
 792     if (!IsStructurallyEquivalent(Context,
 793                                   QualType(Subst1->getReplacedParameter(), 0),
 794                                   QualType(Subst2->getReplacedParameter(), 0)))
 795       return false;
 796     if (!IsStructurallyEquivalent(Context,
 797                                   Subst1->getArgumentPack(),
 798                                   Subst2->getArgumentPack()))
 799       return false;
 800     break;
 801   }
 802   case Type::TemplateSpecialization: {
 803     const TemplateSpecializationType *Spec1
 804       = cast<TemplateSpecializationType>(T1);
 805     const TemplateSpecializationType *Spec2
 806       = cast<TemplateSpecializationType>(T2);
 807     if (!IsStructurallyEquivalent(Context,
 808                                   Spec1->getTemplateName(),
 809                                   Spec2->getTemplateName()))
 810       return false;
 811     if (Spec1->getNumArgs() != Spec2->getNumArgs())
 812       return false;
 813     for (unsigned I = 0, N = Spec1->getNumArgs(); I != N; ++I) {
 814       if (!IsStructurallyEquivalent(Context,
 815                                     Spec1->getArg(I), Spec2->getArg(I)))
 816         return false;
 817     }
 818     break;
 819   }
 820
 821   case Type::Elaborated: {
 822     const ElaboratedType *Elab1 = cast<ElaboratedType>(T1);
 823     const ElaboratedType *Elab2 = cast<ElaboratedType>(T2);
 824     // CHECKME: what if a keyword is ETK_None or ETK_typename ?
 825     if (Elab1->getKeyword() != Elab2->getKeyword())
 826       return false;
 827     if (!IsStructurallyEquivalent(Context,
 828                                   Elab1->getQualifier(),
 829                                   Elab2->getQualifier()))
 830       return false;
 831     if (!IsStructurallyEquivalent(Context,
 832                                   Elab1->getNamedType(),
 833                                   Elab2->getNamedType()))
 834       return false;
 835     break;
 836   }
 837
 838   case Type::InjectedClassName: {
 839     const InjectedClassNameType *Inj1 = cast<InjectedClassNameType>(T1);
 840     const InjectedClassNameType *Inj2 = cast<InjectedClassNameType>(T2);
 841     if (!IsStructurallyEquivalent(Context,
 842                                   Inj1->getInjectedSpecializationType(),
 843                                   Inj2->getInjectedSpecializationType()))
 844       return false;
 845     break;
 846   }
 847
 848   case Type::DependentName: {
 849     const DependentNameType *Typename1 = cast<DependentNameType>(T1);
 850     const DependentNameType *Typename2 = cast<DependentNameType>(T2);
 851     if (!IsStructurallyEquivalent(Context,
 852                                   Typename1->getQualifier(),
 853                                   Typename2->getQualifier()))
 854       return false;
 855     if (!IsStructurallyEquivalent(Typename1->getIdentifier(),
 856                                   Typename2->getIdentifier()))
 857       return false;
 858
 859     break;
 860   }
 861
 862   case Type::DependentTemplateSpecialization: {
 863     const DependentTemplateSpecializationType *Spec1 =
 864       cast<DependentTemplateSpecializationType>(T1);
 865     const DependentTemplateSpecializationType *Spec2 =
 866       cast<DependentTemplateSpecializationType>(T2);
 867     if (!IsStructurallyEquivalent(Context,
 868                                   Spec1->getQualifier(),
 869                                   Spec2->getQualifier()))
 870       return false;
 871     if (!IsStructurallyEquivalent(Spec1->getIdentifier(),
 872                                   Spec2->getIdentifier()))
 873       return false;
 874     if (Spec1->getNumArgs() != Spec2->getNumArgs())
 875       return false;
 876     for (unsigned I = 0, N = Spec1->getNumArgs(); I != N; ++I) {
 877       if (!IsStructurallyEquivalent(Context,
 878                                     Spec1->getArg(I), Spec2->getArg(I)))
 879         return false;
 880     }
 881     break;
 882   }
 883
 884   case Type::PackExpansion:
 885     if (!IsStructurallyEquivalent(Context,
 886                                   cast<PackExpansionType>(T1)->getPattern(),
 887                                   cast<PackExpansionType>(T2)->getPattern()))
 888       return false;
 889     break;
 890
 891   case Type::ObjCInterface: {
 892     const ObjCInterfaceType *Iface1 = cast<ObjCInterfaceType>(T1);
 893     const ObjCInterfaceType *Iface2 = cast<ObjCInterfaceType>(T2);
 894     if (!IsStructurallyEquivalent(Context,
 895                                   Iface1->getDecl(), Iface2->getDecl()))
 896       return false;
 897     break;
 898   }
 899
 900   case Type::ObjCObject: {
 901     const ObjCObjectType *Obj1 = cast<ObjCObjectType>(T1);
 902     const ObjCObjectType *Obj2 = cast<ObjCObjectType>(T2);
 903     if (!IsStructurallyEquivalent(Context,
 904                                   Obj1->getBaseType(),
 905                                   Obj2->getBaseType()))
 906       return false;
 907     if (Obj1->getNumProtocols() != Obj2->getNumProtocols())
 908       return false;
 909     for (unsigned I = 0, N = Obj1->getNumProtocols(); I != N; ++I) {
 910       if (!IsStructurallyEquivalent(Context,
 911                                     Obj1->getProtocol(I),
 912                                     Obj2->getProtocol(I)))
 913         return false;
 914     }
 915     break;
 916   }
 917
 918   case Type::ObjCObjectPointer: {
 919     const ObjCObjectPointerType *Ptr1 = cast<ObjCObjectPointerType>(T1);
 920     const ObjCObjectPointerType *Ptr2 = cast<ObjCObjectPointerType>(T2);
 921     if (!IsStructurallyEquivalent(Context,
 922                                   Ptr1->getPointeeType(),
 923                                   Ptr2->getPointeeType()))
 924       return false;
 925     break;
 926   }
 927
 928   case Type::Atomic: {
 929     if (!IsStructurallyEquivalent(Context,
 930                                   cast<AtomicType>(T1)->getValueType(),
 931                                   cast<AtomicType>(T2)->getValueType()))
 932       return false;
 933     break;
 934   }
 935
 936   case Type::Pipe: {
 937     if (!IsStructurallyEquivalent(Context,
 938                                   cast<PipeType>(T1)->getElementType(),
 939                                   cast<PipeType>(T2)->getElementType()))
 940       return false;
 941     break;
 942   }
 943
 944   } // end switch
 945
 946   return true;
 947 }
 948
 949 /// \brief Determine structural equivalence of two fields.
 950 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
 951                                      FieldDecl *Field1, FieldDecl *Field2) {
 952   RecordDecl *Owner2 = cast<RecordDecl>(Field2->getDeclContext());
 953
 954   // For anonymous structs/unions, match up the anonymous struct/union type
 955   // declarations directly, so that we don't go off searching for anonymous
 956   // types
 957   if (Field1->isAnonymousStructOrUnion() &&
 958       Field2->isAnonymousStructOrUnion()) {
 959     RecordDecl *D1 = Field1->getType()->castAs<RecordType>()->getDecl();
 960     RecordDecl *D2 = Field2->getType()->castAs<RecordType>()->getDecl();
 961     return IsStructurallyEquivalent(Context, D1, D2);
 962   }
 963
 964   // Check for equivalent field names.
 965   IdentifierInfo *Name1 = Field1->getIdentifier();
 966   IdentifierInfo *Name2 = Field2->getIdentifier();
 967   if (!::IsStructurallyEquivalent(Name1, Name2))
 968     return false;
 969
 970   if (!IsStructurallyEquivalent(Context,
 971                                 Field1->getType(), Field2->getType())) {
 972     if (Context.Complain) {
 973       Context.Diag2(Owner2->getLocation(), diag::warn_odr_tag_type_inconsistent)
 974         << Context.C2.getTypeDeclType(Owner2);
 975       Context.Diag2(Field2->getLocation(), diag::note_odr_field)
 976         << Field2->getDeclName() << Field2->getType();
 977       Context.Diag1(Field1->getLocation(), diag::note_odr_field)
 978         << Field1->getDeclName() << Field1->getType();
 979     }
 980     return false;
 981   }
 982
 983   if (Field1->isBitField() != Field2->isBitField()) {
 984     if (Context.Complain) {
 985       Context.Diag2(Owner2->getLocation(), diag::warn_odr_tag_type_inconsistent)
 986         << Context.C2.getTypeDeclType(Owner2);
 987       if (Field1->isBitField()) {
 988         Context.Diag1(Field1->getLocation(), diag::note_odr_bit_field)
 989         << Field1->getDeclName() << Field1->getType()
 990         << Field1->getBitWidthValue(Context.C1);
 991         Context.Diag2(Field2->getLocation(), diag::note_odr_not_bit_field)
 992         << Field2->getDeclName();
 993       } else {
 994         Context.Diag2(Field2->getLocation(), diag::note_odr_bit_field)
 995         << Field2->getDeclName() << Field2->getType()
 996         << Field2->getBitWidthValue(Context.C2);
 997         Context.Diag1(Field1->getLocation(), diag::note_odr_not_bit_field)
 998         << Field1->getDeclName();
 999       }
1000     }
1001     return false;
1002   }
1003
1004   if (Field1->isBitField()) {
1005     // Make sure that the bit-fields are the same length.
1006     unsigned Bits1 = Field1->getBitWidthValue(Context.C1);
1007     unsigned Bits2 = Field2->getBitWidthValue(Context.C2);
1008
1009     if (Bits1 != Bits2) {
1010       if (Context.Complain) {
1011         Context.Diag2(Owner2->getLocation(), diag::warn_odr_tag_type_inconsistent)
1012           << Context.C2.getTypeDeclType(Owner2);
1013         Context.Diag2(Field2->getLocation(), diag::note_odr_bit_field)
1014           << Field2->getDeclName() << Field2->getType() << Bits2;
1015         Context.Diag1(Field1->getLocation(), diag::note_odr_bit_field)
1016           << Field1->getDeclName() << Field1->getType() << Bits1;
1017       }
1018       return false;
1019     }
1020   }
1021
1022   return true;
1023 }
1024
1025 /// \brief Find the index of the given anonymous struct/union within its
1026 /// context.
1027 ///
1028 /// \returns Returns the index of this anonymous struct/union in its context,
1029 /// including the next assigned index (if none of them match). Returns an
1030 /// empty option if the context is not a record, i.e.. if the anonymous
1031 /// struct/union is at namespace or block scope.
1032 static Optional<unsigned> findAnonymousStructOrUnionIndex(RecordDecl *Anon) {
1033   ASTContext &Context = Anon->getASTContext();
1034   QualType AnonTy = Context.getRecordType(Anon);
1035
1036   RecordDecl *Owner = dyn_cast<RecordDecl>(Anon->getDeclContext());
1037   if (!Owner)
1038     return None;
1039
1040   unsigned Index = 0;
1041   for (const auto *D : Owner->noload_decls()) {
1042     const auto *F = dyn_cast<FieldDecl>(D);
1043     if (!F || !F->isAnonymousStructOrUnion())
1044       continue;
1045
1046     if (Context.hasSameType(F->getType(), AnonTy))
1047       break;
1048
1049     ++Index;
1050   }
1051
1052   return Index;
1053 }
1054
1055 /// \brief Determine structural equivalence of two records.
1056 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
1057                                      RecordDecl *D1, RecordDecl *D2) {
1058   if (D1->isUnion() != D2->isUnion()) {
1059     if (Context.Complain) {
1060       Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
1061         << Context.C2.getTypeDeclType(D2);
1062       Context.Diag1(D1->getLocation(), diag::note_odr_tag_kind_here)
1063         << D1->getDeclName() << (unsigned)D1->getTagKind();
1064     }
1065     return false;
1066   }
1067
1068   if (D1->isAnonymousStructOrUnion() && D2->isAnonymousStructOrUnion()) {
1069     // If both anonymous structs/unions are in a record context, make sure
1070     // they occur in the same location in the context records.
1071     if (Optional<unsigned> Index1 = findAnonymousStructOrUnionIndex(D1)) {
1072       if (Optional<unsigned> Index2 = findAnonymousStructOrUnionIndex(D2)) {
1073         if (*Index1 != *Index2)
1074           return false;
1075       }
1076     }
1077   }
1078
1079   // If both declarations are class template specializations, we know
1080   // the ODR applies, so check the template and template arguments.
1081   ClassTemplateSpecializationDecl *Spec1
1082     = dyn_cast<ClassTemplateSpecializationDecl>(D1);
1083   ClassTemplateSpecializationDecl *Spec2
1084     = dyn_cast<ClassTemplateSpecializationDecl>(D2);
1085   if (Spec1 && Spec2) {
1086     // Check that the specialized templates are the same.
1087     if (!IsStructurallyEquivalent(Context, Spec1->getSpecializedTemplate(),
1088                                   Spec2->getSpecializedTemplate()))
1089       return false;
1090
1091     // Check that the template arguments are the same.
1092     if (Spec1->getTemplateArgs().size() != Spec2->getTemplateArgs().size())
1093       return false;
1094
1095     for (unsigned I = 0, N = Spec1->getTemplateArgs().size(); I != N; ++I)
1096       if (!IsStructurallyEquivalent(Context,
1097                                     Spec1->getTemplateArgs().get(I),
1098                                     Spec2->getTemplateArgs().get(I)))
1099         return false;
1100   }
1101   // If one is a class template specialization and the other is not, these
1102   // structures are different.
1103   else if (Spec1 || Spec2)
1104     return false;
1105
1106   // Compare the definitions of these two records. If either or both are
1107   // incomplete, we assume that they are equivalent.
1108   D1 = D1->getDefinition();
1109   D2 = D2->getDefinition();
1110   if (!D1 || !D2)
1111     return true;
1112
1113   if (CXXRecordDecl *D1CXX = dyn_cast<CXXRecordDecl>(D1)) {
1114     if (CXXRecordDecl *D2CXX = dyn_cast<CXXRecordDecl>(D2)) {
1115       if (D1CXX->getNumBases() != D2CXX->getNumBases()) {
1116         if (Context.Complain) {
1117           Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
1118             << Context.C2.getTypeDeclType(D2);
1119           Context.Diag2(D2->getLocation(), diag::note_odr_number_of_bases)
1120             << D2CXX->getNumBases();
1121           Context.Diag1(D1->getLocation(), diag::note_odr_number_of_bases)
1122             << D1CXX->getNumBases();
1123         }
1124         return false;
1125       }
1126
1127       // Check the base classes.
1128       for (CXXRecordDecl::base_class_iterator Base1 = D1CXX->bases_begin(),
1129                                            BaseEnd1 = D1CXX->bases_end(),
1130                                                 Base2 = D2CXX->bases_begin();
1131            Base1 != BaseEnd1;
1132            ++Base1, ++Base2) {
1133         if (!IsStructurallyEquivalent(Context,
1134                                       Base1->getType(), Base2->getType())) {
1135           if (Context.Complain) {
1136             Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
1137               << Context.C2.getTypeDeclType(D2);
1138             Context.Diag2(Base2->getLocStart(), diag::note_odr_base)
1139               << Base2->getType()
1140               << Base2->getSourceRange();
1141             Context.Diag1(Base1->getLocStart(), diag::note_odr_base)
1142               << Base1->getType()
1143               << Base1->getSourceRange();
1144           }
1145           return false;
1146         }
1147
1148         // Check virtual vs. non-virtual inheritance mismatch.
1149         if (Base1->isVirtual() != Base2->isVirtual()) {
1150           if (Context.Complain) {
1151             Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
1152               << Context.C2.getTypeDeclType(D2);
1153             Context.Diag2(Base2->getLocStart(),
1154                           diag::note_odr_virtual_base)
1155               << Base2->isVirtual() << Base2->getSourceRange();
1156             Context.Diag1(Base1->getLocStart(), diag::note_odr_base)
1157               << Base1->isVirtual()
1158               << Base1->getSourceRange();
1159           }
1160           return false;
1161         }
1162       }
1163     } else if (D1CXX->getNumBases() > 0) {
1164       if (Context.Complain) {
1165         Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
1166           << Context.C2.getTypeDeclType(D2);
1167         const CXXBaseSpecifier *Base1 = D1CXX->bases_begin();
1168         Context.Diag1(Base1->getLocStart(), diag::note_odr_base)
1169           << Base1->getType()
1170           << Base1->getSourceRange();
1171         Context.Diag2(D2->getLocation(), diag::note_odr_missing_base);
1172       }
1173       return false;
1174     }
1175   }
1176
1177   // Check the fields for consistency.
1178   RecordDecl::field_iterator Field2 = D2->field_begin(),
1179                              Field2End = D2->field_end();
1180   for (RecordDecl::field_iterator Field1 = D1->field_begin(),
1181                                   Field1End = D1->field_end();
1182        Field1 != Field1End;
1183        ++Field1, ++Field2) {
1184     if (Field2 == Field2End) {
1185       if (Context.Complain) {
1186         Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
1187           << Context.C2.getTypeDeclType(D2);
1188         Context.Diag1(Field1->getLocation(), diag::note_odr_field)
1189           << Field1->getDeclName() << Field1->getType();
1190         Context.Diag2(D2->getLocation(), diag::note_odr_missing_field);
1191       }
1192       return false;
1193     }
1194
1195     if (!IsStructurallyEquivalent(Context, *Field1, *Field2))
1196       return false;
1197   }
1198
1199   if (Field2 != Field2End) {
1200     if (Context.Complain) {
1201       Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
1202         << Context.C2.getTypeDeclType(D2);
1203       Context.Diag2(Field2->getLocation(), diag::note_odr_field)
1204         << Field2->getDeclName() << Field2->getType();
1205       Context.Diag1(D1->getLocation(), diag::note_odr_missing_field);
1206     }
1207     return false;
1208   }
1209
1210   return true;
1211 }
1212
1213 /// \brief Determine structural equivalence of two enums.
1214 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
1215                                      EnumDecl *D1, EnumDecl *D2) {
1216   EnumDecl::enumerator_iterator EC2 = D2->enumerator_begin(),
1217                              EC2End = D2->enumerator_end();
1218   for (EnumDecl::enumerator_iterator EC1 = D1->enumerator_begin(),
1219                                   EC1End = D1->enumerator_end();
1220        EC1 != EC1End; ++EC1, ++EC2) {
1221     if (EC2 == EC2End) {
1222       if (Context.Complain) {
1223         Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
1224           << Context.C2.getTypeDeclType(D2);
1225         Context.Diag1(EC1->getLocation(), diag::note_odr_enumerator)
1226           << EC1->getDeclName()
1227           << EC1->getInitVal().toString(10);
1228         Context.Diag2(D2->getLocation(), diag::note_odr_missing_enumerator);
1229       }
1230       return false;
1231     }
1232
1233     llvm::APSInt Val1 = EC1->getInitVal();
1234     llvm::APSInt Val2 = EC2->getInitVal();
1235     if (!llvm::APSInt::isSameValue(Val1, Val2) ||
1236         !IsStructurallyEquivalent(EC1->getIdentifier(), EC2->getIdentifier())) {
1237       if (Context.Complain) {
1238         Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
1239           << Context.C2.getTypeDeclType(D2);
1240         Context.Diag2(EC2->getLocation(), diag::note_odr_enumerator)
1241           << EC2->getDeclName()
1242           << EC2->getInitVal().toString(10);
1243         Context.Diag1(EC1->getLocation(), diag::note_odr_enumerator)
1244           << EC1->getDeclName()
1245           << EC1->getInitVal().toString(10);
1246       }
1247       return false;
1248     }
1249   }
1250
1251   if (EC2 != EC2End) {
1252     if (Context.Complain) {
1253       Context.Diag2(D2->getLocation(), diag::warn_odr_tag_type_inconsistent)
1254         << Context.C2.getTypeDeclType(D2);
1255       Context.Diag2(EC2->getLocation(), diag::note_odr_enumerator)
1256         << EC2->getDeclName()
1257         << EC2->getInitVal().toString(10);
1258       Context.Diag1(D1->getLocation(), diag::note_odr_missing_enumerator);
1259     }
1260     return false;
1261   }
1262
1263   return true;
1264 }
1265
1266 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
1267                                      TemplateParameterList *Params1,
1268                                      TemplateParameterList *Params2) {
1269   if (Params1->size() != Params2->size()) {
1270     if (Context.Complain) {
1271       Context.Diag2(Params2->getTemplateLoc(),
1272                     diag::err_odr_different_num_template_parameters)
1273         << Params1->size() << Params2->size();
1274       Context.Diag1(Params1->getTemplateLoc(),
1275                     diag::note_odr_template_parameter_list);
1276     }
1277     return false;
1278   }
1279
1280   for (unsigned I = 0, N = Params1->size(); I != N; ++I) {
1281     if (Params1->getParam(I)->getKind() != Params2->getParam(I)->getKind()) {
1282       if (Context.Complain) {
1283         Context.Diag2(Params2->getParam(I)->getLocation(),
1284                       diag::err_odr_different_template_parameter_kind);
1285         Context.Diag1(Params1->getParam(I)->getLocation(),
1286                       diag::note_odr_template_parameter_here);
1287       }
1288       return false;
1289     }
1290
1291     if (!Context.IsStructurallyEquivalent(Params1->getParam(I),
1292                                           Params2->getParam(I))) {
1293
1294       return false;
1295     }
1296   }
1297
1298   return true;
1299 }
1300
1301 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
1302                                      TemplateTypeParmDecl *D1,
1303                                      TemplateTypeParmDecl *D2) {
1304   if (D1->isParameterPack() != D2->isParameterPack()) {
1305     if (Context.Complain) {
1306       Context.Diag2(D2->getLocation(), diag::err_odr_parameter_pack_non_pack)
1307         << D2->isParameterPack();
1308       Context.Diag1(D1->getLocation(), diag::note_odr_parameter_pack_non_pack)
1309         << D1->isParameterPack();
1310     }
1311     return false;
1312   }
1313
1314   return true;
1315 }
1316
1317 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
1318                                      NonTypeTemplateParmDecl *D1,
1319                                      NonTypeTemplateParmDecl *D2) {
1320   if (D1->isParameterPack() != D2->isParameterPack()) {
1321     if (Context.Complain) {
1322       Context.Diag2(D2->getLocation(), diag::err_odr_parameter_pack_non_pack)
1323         << D2->isParameterPack();
1324       Context.Diag1(D1->getLocation(), diag::note_odr_parameter_pack_non_pack)
1325         << D1->isParameterPack();
1326     }
1327     return false;
1328   }
1329
1330   // Check types.
1331   if (!Context.IsStructurallyEquivalent(D1->getType(), D2->getType())) {
1332     if (Context.Complain) {
1333       Context.Diag2(D2->getLocation(),
1334                     diag::err_odr_non_type_parameter_type_inconsistent)
1335         << D2->getType() << D1->getType();
1336       Context.Diag1(D1->getLocation(), diag::note_odr_value_here)
1337         << D1->getType();
1338     }
1339     return false;
1340   }
1341
1342   return true;
1343 }
1344
1345 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
1346                                      TemplateTemplateParmDecl *D1,
1347                                      TemplateTemplateParmDecl *D2) {
1348   if (D1->isParameterPack() != D2->isParameterPack()) {
1349     if (Context.Complain) {
1350       Context.Diag2(D2->getLocation(), diag::err_odr_parameter_pack_non_pack)
1351         << D2->isParameterPack();
1352       Context.Diag1(D1->getLocation(), diag::note_odr_parameter_pack_non_pack)
1353         << D1->isParameterPack();
1354     }
1355     return false;
1356   }
1357
1358   // Check template parameter lists.
1359   return IsStructurallyEquivalent(Context, D1->getTemplateParameters(),
1360                                   D2->getTemplateParameters());
1361 }
1362
1363 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
1364                                      ClassTemplateDecl *D1,
1365                                      ClassTemplateDecl *D2) {
1366   // Check template parameters.
1367   if (!IsStructurallyEquivalent(Context,
1368                                 D1->getTemplateParameters(),
1369                                 D2->getTemplateParameters()))
1370     return false;
1371
1372   // Check the templated declaration.
1373   return Context.IsStructurallyEquivalent(D1->getTemplatedDecl(),
1374                                           D2->getTemplatedDecl());
1375 }
1376
1377 /// \brief Determine structural equivalence of two declarations.
1378 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
1379                                      Decl *D1, Decl *D2) {
1380   // FIXME: Check for known structural equivalences via a callback of some sort.
1381
1382   // Check whether we already know that these two declarations are not
1383   // structurally equivalent.
1384   if (Context.NonEquivalentDecls.count(std::make_pair(D1->getCanonicalDecl(),
1385                                                       D2->getCanonicalDecl())))
1386     return false;
1387
1388   // Determine whether we've already produced a tentative equivalence for D1.
1389   Decl *&EquivToD1 = Context.TentativeEquivalences[D1->getCanonicalDecl()];
1390   if (EquivToD1)
1391     return EquivToD1 == D2->getCanonicalDecl();
1392
1393   // Produce a tentative equivalence D1 <-> D2, which will be checked later.
1394   EquivToD1 = D2->getCanonicalDecl();
1395   Context.DeclsToCheck.push_back(D1->getCanonicalDecl());
1396   return true;
1397 }
1398
1399 bool StructuralEquivalenceContext::IsStructurallyEquivalent(Decl *D1,
1400                                                             Decl *D2) {
1401   if (!::IsStructurallyEquivalent(*this, D1, D2))
1402     return false;
1403
1404   return !Finish();
1405 }
1406
1407 bool StructuralEquivalenceContext::IsStructurallyEquivalent(QualType T1,
1408                                                             QualType T2) {
1409   if (!::IsStructurallyEquivalent(*this, T1, T2))
1410     return false;
1411
1412   return !Finish();
1413 }
1414
1415 bool StructuralEquivalenceContext::Finish() {
1416   while (!DeclsToCheck.empty()) {
1417     // Check the next declaration.
1418     Decl *D1 = DeclsToCheck.front();
1419     DeclsToCheck.pop_front();
1420
1421     Decl *D2 = TentativeEquivalences[D1];
1422     assert(D2 && "Unrecorded tentative equivalence?");
1423
1424     bool Equivalent = true;
1425
1426     // FIXME: Switch on all declaration kinds. For now, we're just going to
1427     // check the obvious ones.
1428     if (RecordDecl *Record1 = dyn_cast<RecordDecl>(D1)) {
1429       if (RecordDecl *Record2 = dyn_cast<RecordDecl>(D2)) {
1430         // Check for equivalent structure names.
1431         IdentifierInfo *Name1 = Record1->getIdentifier();
1432         if (!Name1 && Record1->getTypedefNameForAnonDecl())
1433           Name1 = Record1->getTypedefNameForAnonDecl()->getIdentifier();
1434         IdentifierInfo *Name2 = Record2->getIdentifier();
1435         if (!Name2 && Record2->getTypedefNameForAnonDecl())
1436           Name2 = Record2->getTypedefNameForAnonDecl()->getIdentifier();
1437         if (!::IsStructurallyEquivalent(Name1, Name2) ||
1438             !::IsStructurallyEquivalent(*this, Record1, Record2))
1439           Equivalent = false;
1440       } else {
1441         // Record/non-record mismatch.
1442         Equivalent = false;
1443       }
1444     } else if (EnumDecl *Enum1 = dyn_cast<EnumDecl>(D1)) {
1445       if (EnumDecl *Enum2 = dyn_cast<EnumDecl>(D2)) {
1446         // Check for equivalent enum names.
1447         IdentifierInfo *Name1 = Enum1->getIdentifier();
1448         if (!Name1 && Enum1->getTypedefNameForAnonDecl())
1449           Name1 = Enum1->getTypedefNameForAnonDecl()->getIdentifier();
1450         IdentifierInfo *Name2 = Enum2->getIdentifier();
1451         if (!Name2 && Enum2->getTypedefNameForAnonDecl())
1452           Name2 = Enum2->getTypedefNameForAnonDecl()->getIdentifier();
1453         if (!::IsStructurallyEquivalent(Name1, Name2) ||
1454             !::IsStructurallyEquivalent(*this, Enum1, Enum2))
1455           Equivalent = false;
1456       } else {
1457         // Enum/non-enum mismatch
1458         Equivalent = false;
1459       }
1460     } else if (TypedefNameDecl *Typedef1 = dyn_cast<TypedefNameDecl>(D1)) {
1461       if (TypedefNameDecl *Typedef2 = dyn_cast<TypedefNameDecl>(D2)) {
1462         if (!::IsStructurallyEquivalent(Typedef1->getIdentifier(),
1463                                         Typedef2->getIdentifier()) ||
1464             !::IsStructurallyEquivalent(*this,
1465                                         Typedef1->getUnderlyingType(),
1466                                         Typedef2->getUnderlyingType()))
1467           Equivalent = false;
1468       } else {
1469         // Typedef/non-typedef mismatch.
1470         Equivalent = false;
1471       }
1472     } else if (ClassTemplateDecl *ClassTemplate1
1473                                            = dyn_cast<ClassTemplateDecl>(D1)) {
1474       if (ClassTemplateDecl *ClassTemplate2 = dyn_cast<ClassTemplateDecl>(D2)) {
1475         if (!::IsStructurallyEquivalent(ClassTemplate1->getIdentifier(),
1476                                         ClassTemplate2->getIdentifier()) ||
1477             !::IsStructurallyEquivalent(*this, ClassTemplate1, ClassTemplate2))
1478           Equivalent = false;
1479       } else {
1480         // Class template/non-class-template mismatch.
1481         Equivalent = false;
1482       }
1483     } else if (TemplateTypeParmDecl *TTP1= dyn_cast<TemplateTypeParmDecl>(D1)) {
1484       if (TemplateTypeParmDecl *TTP2 = dyn_cast<TemplateTypeParmDecl>(D2)) {
1485         if (!::IsStructurallyEquivalent(*this, TTP1, TTP2))
1486           Equivalent = false;
1487       } else {
1488         // Kind mismatch.
1489         Equivalent = false;
1490       }
1491     } else if (NonTypeTemplateParmDecl *NTTP1
1492                                      = dyn_cast<NonTypeTemplateParmDecl>(D1)) {
1493       if (NonTypeTemplateParmDecl *NTTP2
1494                                       = dyn_cast<NonTypeTemplateParmDecl>(D2)) {
1495         if (!::IsStructurallyEquivalent(*this, NTTP1, NTTP2))
1496           Equivalent = false;
1497       } else {
1498         // Kind mismatch.
1499         Equivalent = false;
1500       }
1501     } else if (TemplateTemplateParmDecl *TTP1
1502                                   = dyn_cast<TemplateTemplateParmDecl>(D1)) {
1503       if (TemplateTemplateParmDecl *TTP2
1504                                     = dyn_cast<TemplateTemplateParmDecl>(D2)) {
1505         if (!::IsStructurallyEquivalent(*this, TTP1, TTP2))
1506           Equivalent = false;
1507       } else {
1508         // Kind mismatch.
1509         Equivalent = false;
1510       }
1511     }
1512
1513     if (!Equivalent) {
1514       // Note that these two declarations are not equivalent (and we already
1515       // know about it).
1516       NonEquivalentDecls.insert(std::make_pair(D1->getCanonicalDecl(),
1517                                                D2->getCanonicalDecl()));
1518       return true;
1519     }
1520     // FIXME: Check other declaration kinds!
1521   }
1522
1523   return false;
1524 }
1525
1526 //----------------------------------------------------------------------------
1527 // Import Types
1528 //----------------------------------------------------------------------------
1529
1530 QualType ASTNodeImporter::VisitType(const Type *T) {
1531   Importer.FromDiag(SourceLocation(), diag::err_unsupported_ast_node)
1532     << T->getTypeClassName();
1533   return QualType();
1534 }
1535
1536 QualType ASTNodeImporter::VisitBuiltinType(const BuiltinType *T) {
1537   switch (T->getKind()) {
1538 #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
1539   case BuiltinType::Id: \
1540     return Importer.getToContext().SingletonId;
1541 #include "clang/Basic/OpenCLImageTypes.def"
1542 #define SHARED_SINGLETON_TYPE(Expansion)
1543 #define BUILTIN_TYPE(Id, SingletonId) \
1544   case BuiltinType::Id: return Importer.getToContext().SingletonId;
1545 #include "clang/AST/BuiltinTypes.def"
1546
1547   // FIXME: for Char16, Char32, and NullPtr, make sure that the "to"
1548   // context supports C++.
1549
1550   // FIXME: for ObjCId, ObjCClass, and ObjCSel, make sure that the "to"
1551   // context supports ObjC.
1552
1553   case BuiltinType::Char_U:
1554     // The context we're importing from has an unsigned 'char'. If we're
1555     // importing into a context with a signed 'char', translate to
1556     // 'unsigned char' instead.
1557     if (Importer.getToContext().getLangOpts().CharIsSigned)
1558       return Importer.getToContext().UnsignedCharTy;
1559
1560     return Importer.getToContext().CharTy;
1561
1562   case BuiltinType::Char_S:
1563     // The context we're importing from has an unsigned 'char'. If we're
1564     // importing into a context with a signed 'char', translate to
1565     // 'unsigned char' instead.
1566     if (!Importer.getToContext().getLangOpts().CharIsSigned)
1567       return Importer.getToContext().SignedCharTy;
1568
1569     return Importer.getToContext().CharTy;
1570
1571   case BuiltinType::WChar_S:
1572   case BuiltinType::WChar_U:
1573     // FIXME: If not in C++, shall we translate to the C equivalent of
1574     // wchar_t?
1575     return Importer.getToContext().WCharTy;
1576   }
1577
1578   llvm_unreachable("Invalid BuiltinType Kind!");
1579 }
1580
1581 QualType ASTNodeImporter::VisitComplexType(const ComplexType *T) {
1582   QualType ToElementType = Importer.Import(T->getElementType());
1583   if (ToElementType.isNull())
1584     return QualType();
1585
1586   return Importer.getToContext().getComplexType(ToElementType);
1587 }
1588
1589 QualType ASTNodeImporter::VisitPointerType(const PointerType *T) {
1590   QualType ToPointeeType = Importer.Import(T->getPointeeType());
1591   if (ToPointeeType.isNull())
1592     return QualType();
1593
1594   return Importer.getToContext().getPointerType(ToPointeeType);
1595 }
1596
1597 QualType ASTNodeImporter::VisitBlockPointerType(const BlockPointerType *T) {
1598   // FIXME: Check for blocks support in "to" context.
1599   QualType ToPointeeType = Importer.Import(T->getPointeeType());
1600   if (ToPointeeType.isNull())
1601     return QualType();
1602
1603   return Importer.getToContext().getBlockPointerType(ToPointeeType);
1604 }
1605
1606 QualType
1607 ASTNodeImporter::VisitLValueReferenceType(const LValueReferenceType *T) {
1608   // FIXME: Check for C++ support in "to" context.
1609   QualType ToPointeeType = Importer.Import(T->getPointeeTypeAsWritten());
1610   if (ToPointeeType.isNull())
1611     return QualType();
1612
1613   return Importer.getToContext().getLValueReferenceType(ToPointeeType);
1614 }
1615
1616 QualType
1617 ASTNodeImporter::VisitRValueReferenceType(const RValueReferenceType *T) {
1618   // FIXME: Check for C++0x support in "to" context.
1619   QualType ToPointeeType = Importer.Import(T->getPointeeTypeAsWritten());
1620   if (ToPointeeType.isNull())
1621     return QualType();
1622
1623   return Importer.getToContext().getRValueReferenceType(ToPointeeType);
1624 }
1625
1626 QualType ASTNodeImporter::VisitMemberPointerType(const MemberPointerType *T) {
1627   // FIXME: Check for C++ support in "to" context.
1628   QualType ToPointeeType = Importer.Import(T->getPointeeType());
1629   if (ToPointeeType.isNull())
1630     return QualType();
1631
1632   QualType ClassType = Importer.Import(QualType(T->getClass(), 0));
1633   return Importer.getToContext().getMemberPointerType(ToPointeeType,
1634                                                       ClassType.getTypePtr());
1635 }
1636
1637 QualType ASTNodeImporter::VisitConstantArrayType(const ConstantArrayType *T) {
1638   QualType ToElementType = Importer.Import(T->getElementType());
1639   if (ToElementType.isNull())
1640     return QualType();
1641
1642   return Importer.getToContext().getConstantArrayType(ToElementType,
1643                                                       T->getSize(),
1644                                                       T->getSizeModifier(),
1645                                                T->getIndexTypeCVRQualifiers());
1646 }
1647
1648 QualType
1649 ASTNodeImporter::VisitIncompleteArrayType(const IncompleteArrayType *T) {
1650   QualType ToElementType = Importer.Import(T->getElementType());
1651   if (ToElementType.isNull())
1652     return QualType();
1653
1654   return Importer.getToContext().getIncompleteArrayType(ToElementType,
1655                                                         T->getSizeModifier(),
1656                                                 T->getIndexTypeCVRQualifiers());
1657 }
1658
1659 QualType ASTNodeImporter::VisitVariableArrayType(const VariableArrayType *T) {
1660   QualType ToElementType = Importer.Import(T->getElementType());
1661   if (ToElementType.isNull())
1662     return QualType();
1663
1664   Expr *Size = Importer.Import(T->getSizeExpr());
1665   if (!Size)
1666     return QualType();
1667
1668   SourceRange Brackets = Importer.Import(T->getBracketsRange());
1669   return Importer.getToContext().getVariableArrayType(ToElementType, Size,
1670                                                       T->getSizeModifier(),
1671                                                 T->getIndexTypeCVRQualifiers(),
1672                                                       Brackets);
1673 }
1674
1675 QualType ASTNodeImporter::VisitVectorType(const VectorType *T) {
1676   QualType ToElementType = Importer.Import(T->getElementType());
1677   if (ToElementType.isNull())
1678     return QualType();
1679
1680   return Importer.getToContext().getVectorType(ToElementType,
1681                                                T->getNumElements(),
1682                                                T->getVectorKind());
1683 }
1684
1685 QualType ASTNodeImporter::VisitExtVectorType(const ExtVectorType *T) {
1686   QualType ToElementType = Importer.Import(T->getElementType());
1687   if (ToElementType.isNull())
1688     return QualType();
1689
1690   return Importer.getToContext().getExtVectorType(ToElementType,
1691                                                   T->getNumElements());
1692 }
1693
1694 QualType
1695 ASTNodeImporter::VisitFunctionNoProtoType(const FunctionNoProtoType *T) {
1696   // FIXME: What happens if we're importing a function without a prototype
1697   // into C++? Should we make it variadic?
1698   QualType ToResultType = Importer.Import(T->getReturnType());
1699   if (ToResultType.isNull())
1700     return QualType();
1701
1702   return Importer.getToContext().getFunctionNoProtoType(ToResultType,
1703                                                         T->getExtInfo());
1704 }
1705
1706 QualType ASTNodeImporter::VisitFunctionProtoType(const FunctionProtoType *T) {
1707   QualType ToResultType = Importer.Import(T->getReturnType());
1708   if (ToResultType.isNull())
1709     return QualType();
1710
1711   // Import argument types
1712   SmallVector<QualType, 4> ArgTypes;
1713   for (const auto &A : T->param_types()) {
1714     QualType ArgType = Importer.Import(A);
1715     if (ArgType.isNull())
1716       return QualType();
1717     ArgTypes.push_back(ArgType);
1718   }
1719
1720   // Import exception types
1721   SmallVector<QualType, 4> ExceptionTypes;
1722   for (const auto &E : T->exceptions()) {
1723     QualType ExceptionType = Importer.Import(E);
1724     if (ExceptionType.isNull())
1725       return QualType();
1726     ExceptionTypes.push_back(ExceptionType);
1727   }
1728
1729   FunctionProtoType::ExtProtoInfo FromEPI = T->getExtProtoInfo();
1730   FunctionProtoType::ExtProtoInfo ToEPI;
1731
1732   ToEPI.ExtInfo = FromEPI.ExtInfo;
1733   ToEPI.Variadic = FromEPI.Variadic;
1734   ToEPI.HasTrailingReturn = FromEPI.HasTrailingReturn;
1735   ToEPI.TypeQuals = FromEPI.TypeQuals;
1736   ToEPI.RefQualifier = FromEPI.RefQualifier;
1737   ToEPI.ExceptionSpec.Type = FromEPI.ExceptionSpec.Type;
1738   ToEPI.ExceptionSpec.Exceptions = ExceptionTypes;
1739   ToEPI.ExceptionSpec.NoexceptExpr =
1740       Importer.Import(FromEPI.ExceptionSpec.NoexceptExpr);
1741   ToEPI.ExceptionSpec.SourceDecl = cast_or_null<FunctionDecl>(
1742       Importer.Import(FromEPI.ExceptionSpec.SourceDecl));
1743   ToEPI.ExceptionSpec.SourceTemplate = cast_or_null<FunctionDecl>(
1744       Importer.Import(FromEPI.ExceptionSpec.SourceTemplate));
1745
1746   return Importer.getToContext().getFunctionType(ToResultType, ArgTypes, ToEPI);
1747 }
1748
1749 QualType ASTNodeImporter::VisitParenType(const ParenType *T) {
1750   QualType ToInnerType = Importer.Import(T->getInnerType());
1751   if (ToInnerType.isNull())
1752     return QualType();
1753
1754   return Importer.getToContext().getParenType(ToInnerType);
1755 }
1756
1757 QualType ASTNodeImporter::VisitTypedefType(const TypedefType *T) {
1758   TypedefNameDecl *ToDecl
1759              = dyn_cast_or_null<TypedefNameDecl>(Importer.Import(T->getDecl()));
1760   if (!ToDecl)
1761     return QualType();
1762
1763   return Importer.getToContext().getTypeDeclType(ToDecl);
1764 }
1765
1766 QualType ASTNodeImporter::VisitTypeOfExprType(const TypeOfExprType *T) {
1767   Expr *ToExpr = Importer.Import(T->getUnderlyingExpr());
1768   if (!ToExpr)
1769     return QualType();
1770
1771   return Importer.getToContext().getTypeOfExprType(ToExpr);
1772 }
1773
1774 QualType ASTNodeImporter::VisitTypeOfType(const TypeOfType *T) {
1775   QualType ToUnderlyingType = Importer.Import(T->getUnderlyingType());
1776   if (ToUnderlyingType.isNull())
1777     return QualType();
1778
1779   return Importer.getToContext().getTypeOfType(ToUnderlyingType);
1780 }
1781
1782 QualType ASTNodeImporter::VisitDecltypeType(const DecltypeType *T) {
1783   // FIXME: Make sure that the "to" context supports C++0x!
1784   Expr *ToExpr = Importer.Import(T->getUnderlyingExpr());
1785   if (!ToExpr)
1786     return QualType();
1787
1788   QualType UnderlyingType = Importer.Import(T->getUnderlyingType());
1789   if (UnderlyingType.isNull())
1790     return QualType();
1791
1792   return Importer.getToContext().getDecltypeType(ToExpr, UnderlyingType);
1793 }
1794
1795 QualType ASTNodeImporter::VisitUnaryTransformType(const UnaryTransformType *T) {
1796   QualType ToBaseType = Importer.Import(T->getBaseType());
1797   QualType ToUnderlyingType = Importer.Import(T->getUnderlyingType());
1798   if (ToBaseType.isNull() || ToUnderlyingType.isNull())
1799     return QualType();
1800
1801   return Importer.getToContext().getUnaryTransformType(ToBaseType,
1802                                                        ToUnderlyingType,
1803                                                        T->getUTTKind());
1804 }
1805
1806 QualType ASTNodeImporter::VisitAutoType(const AutoType *T) {
1807   // FIXME: Make sure that the "to" context supports C++11!
1808   QualType FromDeduced = T->getDeducedType();
1809   QualType ToDeduced;
1810   if (!FromDeduced.isNull()) {
1811     ToDeduced = Importer.Import(FromDeduced);
1812     if (ToDeduced.isNull())
1813       return QualType();
1814   }
1815
1816   return Importer.getToContext().getAutoType(ToDeduced, T->getKeyword(),
1817                                              /*IsDependent*/false);
1818 }
1819
1820 QualType ASTNodeImporter::VisitInjectedClassNameType(
1821     const InjectedClassNameType *T) {
1822   CXXRecordDecl *D = cast_or_null<CXXRecordDecl>(Importer.Import(T->getDecl()));
1823   if (!D)
1824     return QualType();
1825
1826   QualType InjType = Importer.Import(T->getInjectedSpecializationType());
1827   if (InjType.isNull())
1828     return QualType();
1829
1830   // FIXME: ASTContext::getInjectedClassNameType is not suitable for AST reading
1831   // See comments in InjectedClassNameType definition for details
1832   // return Importer.getToContext().getInjectedClassNameType(D, InjType);
1833   enum {
1834     TypeAlignmentInBits = 4,
1835     TypeAlignment = 1 << TypeAlignmentInBits
1836   };
1837
1838   return QualType(new (Importer.getToContext(), TypeAlignment)
1839                   InjectedClassNameType(D, InjType), 0);
1840 }
1841
1842 QualType ASTNodeImporter::VisitRecordType(const RecordType *T) {
1843   RecordDecl *ToDecl
1844     = dyn_cast_or_null<RecordDecl>(Importer.Import(T->getDecl()));
1845   if (!ToDecl)
1846     return QualType();
1847
1848   return Importer.getToContext().getTagDeclType(ToDecl);
1849 }
1850
1851 QualType ASTNodeImporter::VisitEnumType(const EnumType *T) {
1852   EnumDecl *ToDecl
1853     = dyn_cast_or_null<EnumDecl>(Importer.Import(T->getDecl()));
1854   if (!ToDecl)
1855     return QualType();
1856
1857   return Importer.getToContext().getTagDeclType(ToDecl);
1858 }
1859
1860 QualType ASTNodeImporter::VisitAttributedType(const AttributedType *T) {
1861   QualType FromModifiedType = T->getModifiedType();
1862   QualType FromEquivalentType = T->getEquivalentType();
1863   QualType ToModifiedType;
1864   QualType ToEquivalentType;
1865
1866   if (!FromModifiedType.isNull()) {
1867     ToModifiedType = Importer.Import(FromModifiedType);
1868     if (ToModifiedType.isNull())
1869       return QualType();
1870   }
1871   if (!FromEquivalentType.isNull()) {
1872     ToEquivalentType = Importer.Import(FromEquivalentType);
1873     if (ToEquivalentType.isNull())
1874       return QualType();
1875   }
1876
1877   return Importer.getToContext().getAttributedType(T->getAttrKind(),
1878     ToModifiedType, ToEquivalentType);
1879 }
1880
1881
1882 QualType ASTNodeImporter::VisitTemplateTypeParmType(
1883     const TemplateTypeParmType *T) {
1884   TemplateTypeParmDecl *ParmDecl =
1885       cast_or_null<TemplateTypeParmDecl>(Importer.Import(T->getDecl()));
1886   if (!ParmDecl && T->getDecl())
1887     return QualType();
1888
1889   return Importer.getToContext().getTemplateTypeParmType(
1890         T->getDepth(), T->getIndex(), T->isParameterPack(), ParmDecl);
1891 }
1892
1893 QualType ASTNodeImporter::VisitTemplateSpecializationType(
1894                                        const TemplateSpecializationType *T) {
1895   TemplateName ToTemplate = Importer.Import(T->getTemplateName());
1896   if (ToTemplate.isNull())
1897     return QualType();
1898
1899   SmallVector<TemplateArgument, 2> ToTemplateArgs;
1900   if (ImportTemplateArguments(T->getArgs(), T->getNumArgs(), ToTemplateArgs))
1901     return QualType();
1902
1903   QualType ToCanonType;
1904   if (!QualType(T, 0).isCanonical()) {
1905     QualType FromCanonType
1906       = Importer.getFromContext().getCanonicalType(QualType(T, 0));
1907     ToCanonType =Importer.Import(FromCanonType);
1908     if (ToCanonType.isNull())
1909       return QualType();
1910   }
1911   return Importer.getToContext().getTemplateSpecializationType(ToTemplate,
1912                                                          ToTemplateArgs.data(),
1913                                                          ToTemplateArgs.size(),
1914                                                                ToCanonType);
1915 }
1916
1917 QualType ASTNodeImporter::VisitElaboratedType(const ElaboratedType *T) {
1918   NestedNameSpecifier *ToQualifier = nullptr;
1919   // Note: the qualifier in an ElaboratedType is optional.
1920   if (T->getQualifier()) {
1921     ToQualifier = Importer.Import(T->getQualifier());
1922     if (!ToQualifier)
1923       return QualType();
1924   }
1925
1926   QualType ToNamedType = Importer.Import(T->getNamedType());
1927   if (ToNamedType.isNull())
1928     return QualType();
1929
1930   return Importer.getToContext().getElaboratedType(T->getKeyword(),
1931                                                    ToQualifier, ToNamedType);
1932 }
1933
1934 QualType ASTNodeImporter::VisitObjCInterfaceType(const ObjCInterfaceType *T) {
1935   ObjCInterfaceDecl *Class
1936     = dyn_cast_or_null<ObjCInterfaceDecl>(Importer.Import(T->getDecl()));
1937   if (!Class)
1938     return QualType();
1939
1940   return Importer.getToContext().getObjCInterfaceType(Class);
1941 }
1942
1943 QualType ASTNodeImporter::VisitObjCObjectType(const ObjCObjectType *T) {
1944   QualType ToBaseType = Importer.Import(T->getBaseType());
1945   if (ToBaseType.isNull())
1946     return QualType();
1947
1948   SmallVector<QualType, 4> TypeArgs;
1949   for (auto TypeArg : T->getTypeArgsAsWritten()) {
1950     QualType ImportedTypeArg = Importer.Import(TypeArg);
1951     if (ImportedTypeArg.isNull())
1952       return QualType();
1953
1954     TypeArgs.push_back(ImportedTypeArg);
1955   }
1956
1957   SmallVector<ObjCProtocolDecl *, 4> Protocols;
1958   for (auto *P : T->quals()) {
1959     ObjCProtocolDecl *Protocol
1960       = dyn_cast_or_null<ObjCProtocolDecl>(Importer.Import(P));
1961     if (!Protocol)
1962       return QualType();
1963     Protocols.push_back(Protocol);
1964   }
1965
1966   return Importer.getToContext().getObjCObjectType(ToBaseType, TypeArgs,
1967                                                    Protocols,
1968                                                    T->isKindOfTypeAsWritten());
1969 }
1970
1971 QualType
1972 ASTNodeImporter::VisitObjCObjectPointerType(const ObjCObjectPointerType *T) {
1973   QualType ToPointeeType = Importer.Import(T->getPointeeType());
1974   if (ToPointeeType.isNull())
1975     return QualType();
1976
1977   return Importer.getToContext().getObjCObjectPointerType(ToPointeeType);
1978 }
1979
1980 //----------------------------------------------------------------------------
1981 // Import Declarations
1982 //----------------------------------------------------------------------------
1983 bool ASTNodeImporter::ImportDeclParts(NamedDecl *D, DeclContext *&DC,
1984                                       DeclContext *&LexicalDC,
1985                                       DeclarationName &Name,
1986                                       NamedDecl *&ToD,
1987                                       SourceLocation &Loc) {
1988   // Import the context of this declaration.
1989   DC = Importer.ImportContext(D->getDeclContext());
1990   if (!DC)
1991     return true;
1992
1993   LexicalDC = DC;
1994   if (D->getDeclContext() != D->getLexicalDeclContext()) {
1995     LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
1996     if (!LexicalDC)
1997       return true;
1998   }
1999
2000   // Import the name of this declaration.
2001   Name = Importer.Import(D->getDeclName());
2002   if (D->getDeclName() && !Name)
2003     return true;
2004
2005   // Import the location of this declaration.
2006   Loc = Importer.Import(D->getLocation());
2007   ToD = cast_or_null<NamedDecl>(Importer.GetAlreadyImportedOrNull(D));
2008   return false;
2009 }
2010
2011 void ASTNodeImporter::ImportDefinitionIfNeeded(Decl *FromD, Decl *ToD) {
2012   if (!FromD)
2013     return;
2014
2015   if (!ToD) {
2016     ToD = Importer.Import(FromD);
2017     if (!ToD)
2018       return;
2019   }
2020
2021   if (RecordDecl *FromRecord = dyn_cast<RecordDecl>(FromD)) {
2022     if (RecordDecl *ToRecord = cast_or_null<RecordDecl>(ToD)) {
2023       if (FromRecord->getDefinition() && FromRecord->isCompleteDefinition() && !ToRecord->getDefinition()) {
2024         ImportDefinition(FromRecord, ToRecord);
2025       }
2026     }
2027     return;
2028   }
2029
2030   if (EnumDecl *FromEnum = dyn_cast<EnumDecl>(FromD)) {
2031     if (EnumDecl *ToEnum = cast_or_null<EnumDecl>(ToD)) {
2032       if (FromEnum->getDefinition() && !ToEnum->getDefinition()) {
2033         ImportDefinition(FromEnum, ToEnum);
2034       }
2035     }
2036     return;
2037   }
2038 }
2039
2040 void
2041 ASTNodeImporter::ImportDeclarationNameLoc(const DeclarationNameInfo &From,
2042                                           DeclarationNameInfo& To) {
2043   // NOTE: To.Name and To.Loc are already imported.
2044   // We only have to import To.LocInfo.
2045   switch (To.getName().getNameKind()) {
2046   case DeclarationName::Identifier:
2047   case DeclarationName::ObjCZeroArgSelector:
2048   case DeclarationName::ObjCOneArgSelector:
2049   case DeclarationName::ObjCMultiArgSelector:
2050   case DeclarationName::CXXUsingDirective:
2051     return;
2052
2053   case DeclarationName::CXXOperatorName: {
2054     SourceRange Range = From.getCXXOperatorNameRange();
2055     To.setCXXOperatorNameRange(Importer.Import(Range));
2056     return;
2057   }
2058   case DeclarationName::CXXLiteralOperatorName: {
2059     SourceLocation Loc = From.getCXXLiteralOperatorNameLoc();
2060     To.setCXXLiteralOperatorNameLoc(Importer.Import(Loc));
2061     return;
2062   }
2063   case DeclarationName::CXXConstructorName:
2064   case DeclarationName::CXXDestructorName:
2065   case DeclarationName::CXXConversionFunctionName: {
2066     TypeSourceInfo *FromTInfo = From.getNamedTypeInfo();
2067     To.setNamedTypeInfo(Importer.Import(FromTInfo));
2068     return;
2069   }
2070   }
2071   llvm_unreachable("Unknown name kind.");
2072 }
2073
2074 void ASTNodeImporter::ImportDeclContext(DeclContext *FromDC, bool ForceImport) {
2075   if (Importer.isMinimalImport() && !ForceImport) {
2076     Importer.ImportContext(FromDC);
2077     return;
2078   }
2079
2080   for (auto *From : FromDC->decls())
2081     Importer.Import(From);
2082 }
2083
2084 bool ASTNodeImporter::ImportDefinition(RecordDecl *From, RecordDecl *To,
2085                                        ImportDefinitionKind Kind) {
2086   if (To->getDefinition() || To->isBeingDefined()) {
2087     if (Kind == IDK_Everything)
2088       ImportDeclContext(From, /*ForceImport=*/true);
2089
2090     return false;
2091   }
2092
2093   To->startDefinition();
2094
2095   // Add base classes.
2096   if (CXXRecordDecl *ToCXX = dyn_cast<CXXRecordDecl>(To)) {
2097     CXXRecordDecl *FromCXX = cast<CXXRecordDecl>(From);
2098
2099     struct CXXRecordDecl::DefinitionData &ToData = ToCXX->data();
2100     struct CXXRecordDecl::DefinitionData &FromData = FromCXX->data();
2101     ToData.UserDeclaredConstructor = FromData.UserDeclaredConstructor;
2102     ToData.UserDeclaredSpecialMembers = FromData.UserDeclaredSpecialMembers;
2103     ToData.Aggregate = FromData.Aggregate;
2104     ToData.PlainOldData = FromData.PlainOldData;
2105     ToData.Empty = FromData.Empty;
2106     ToData.Polymorphic = FromData.Polymorphic;
2107     ToData.Abstract = FromData.Abstract;
2108     ToData.IsStandardLayout = FromData.IsStandardLayout;
2109     ToData.HasNoNonEmptyBases = FromData.HasNoNonEmptyBases;
2110     ToData.HasPrivateFields = FromData.HasPrivateFields;
2111     ToData.HasProtectedFields = FromData.HasProtectedFields;
2112     ToData.HasPublicFields = FromData.HasPublicFields;
2113     ToData.HasMutableFields = FromData.HasMutableFields;
2114     ToData.HasVariantMembers = FromData.HasVariantMembers;
2115     ToData.HasOnlyCMembers = FromData.HasOnlyCMembers;
2116     ToData.HasInClassInitializer = FromData.HasInClassInitializer;
2117     ToData.HasUninitializedReferenceMember
2118       = FromData.HasUninitializedReferenceMember;
2119     ToData.HasUninitializedFields = FromData.HasUninitializedFields;
2120     ToData.HasInheritedConstructor = FromData.HasInheritedConstructor;
2121     ToData.HasInheritedAssignment = FromData.HasInheritedAssignment;
2122     ToData.NeedOverloadResolutionForMoveConstructor
2123       = FromData.NeedOverloadResolutionForMoveConstructor;
2124     ToData.NeedOverloadResolutionForMoveAssignment
2125       = FromData.NeedOverloadResolutionForMoveAssignment;
2126     ToData.NeedOverloadResolutionForDestructor
2127       = FromData.NeedOverloadResolutionForDestructor;
2128     ToData.DefaultedMoveConstructorIsDeleted
2129       = FromData.DefaultedMoveConstructorIsDeleted;
2130     ToData.DefaultedMoveAssignmentIsDeleted
2131       = FromData.DefaultedMoveAssignmentIsDeleted;
2132     ToData.DefaultedDestructorIsDeleted = FromData.DefaultedDestructorIsDeleted;
2133     ToData.HasTrivialSpecialMembers = FromData.HasTrivialSpecialMembers;
2134     ToData.HasIrrelevantDestructor = FromData.HasIrrelevantDestructor;
2135     ToData.HasConstexprNonCopyMoveConstructor
2136       = FromData.HasConstexprNonCopyMoveConstructor;
2137     ToData.HasDefaultedDefaultConstructor
2138       = FromData.HasDefaultedDefaultConstructor;
2139     ToData.DefaultedDefaultConstructorIsConstexpr
2140       = FromData.DefaultedDefaultConstructorIsConstexpr;
2141     ToData.HasConstexprDefaultConstructor
2142       = FromData.HasConstexprDefaultConstructor;
2143     ToData.HasNonLiteralTypeFieldsOrBases
2144       = FromData.HasNonLiteralTypeFieldsOrBases;
2145     // ComputedVisibleConversions not imported.
2146     ToData.UserProvidedDefaultConstructor
2147       = FromData.UserProvidedDefaultConstructor;
2148     ToData.DeclaredSpecialMembers = FromData.DeclaredSpecialMembers;
2149     ToData.ImplicitCopyConstructorHasConstParam
2150       = FromData.ImplicitCopyConstructorHasConstParam;
2151     ToData.ImplicitCopyAssignmentHasConstParam
2152       = FromData.ImplicitCopyAssignmentHasConstParam;
2153     ToData.HasDeclaredCopyConstructorWithConstParam
2154       = FromData.HasDeclaredCopyConstructorWithConstParam;
2155     ToData.HasDeclaredCopyAssignmentWithConstParam
2156       = FromData.HasDeclaredCopyAssignmentWithConstParam;
2157     ToData.IsLambda = FromData.IsLambda;
2158
2159     SmallVector<CXXBaseSpecifier *, 4> Bases;
2160     for (const auto &Base1 : FromCXX->bases()) {
2161       QualType T = Importer.Import(Base1.getType());
2162       if (T.isNull())
2163         return true;
2164
2165       SourceLocation EllipsisLoc;
2166       if (Base1.isPackExpansion())
2167         EllipsisLoc = Importer.Import(Base1.getEllipsisLoc());
2168
2169       // Ensure that we have a definition for the base.
2170       ImportDefinitionIfNeeded(Base1.getType()->getAsCXXRecordDecl());
2171
2172       Bases.push_back(
2173                     new (Importer.getToContext())
2174                       CXXBaseSpecifier(Importer.Import(Base1.getSourceRange()),
2175                                        Base1.isVirtual(),
2176                                        Base1.isBaseOfClass(),
2177                                        Base1.getAccessSpecifierAsWritten(),
2178                                    Importer.Import(Base1.getTypeSourceInfo()),
2179                                        EllipsisLoc));
2180     }
2181     if (!Bases.empty())
2182       ToCXX->setBases(Bases.data(), Bases.size());
2183   }
2184
2185   if (shouldForceImportDeclContext(Kind))
2186     ImportDeclContext(From, /*ForceImport=*/true);
2187
2188   To->completeDefinition();
2189   return false;
2190 }
2191
2192 bool ASTNodeImporter::ImportDefinition(VarDecl *From, VarDecl *To,
2193                                        ImportDefinitionKind Kind) {
2194   if (To->getAnyInitializer())
2195     return false;
2196
2197   // FIXME: Can we really import any initializer? Alternatively, we could force
2198   // ourselves to import every declaration of a variable and then only use
2199   // getInit() here.
2200   To->setInit(Importer.Import(const_cast<Expr *>(From->getAnyInitializer())));
2201
2202   // FIXME: Other bits to merge?
2203
2204   return false;
2205 }
2206
2207 bool ASTNodeImporter::ImportDefinition(EnumDecl *From, EnumDecl *To,
2208                                        ImportDefinitionKind Kind) {
2209   if (To->getDefinition() || To->isBeingDefined()) {
2210     if (Kind == IDK_Everything)
2211       ImportDeclContext(From, /*ForceImport=*/true);
2212     return false;
2213   }
2214
2215   To->startDefinition();
2216
2217   QualType T = Importer.Import(Importer.getFromContext().getTypeDeclType(From));
2218   if (T.isNull())
2219     return true;
2220
2221   QualType ToPromotionType = Importer.Import(From->getPromotionType());
2222   if (ToPromotionType.isNull())
2223     return true;
2224
2225   if (shouldForceImportDeclContext(Kind))
2226     ImportDeclContext(From, /*ForceImport=*/true);
2227
2228   // FIXME: we might need to merge the number of positive or negative bits
2229   // if the enumerator lists don't match.
2230   To->completeDefinition(T, ToPromotionType,
2231                          From->getNumPositiveBits(),
2232                          From->getNumNegativeBits());
2233   return false;
2234 }
2235
2236 TemplateParameterList *ASTNodeImporter::ImportTemplateParameterList(
2237                                                 TemplateParameterList *Params) {
2238   SmallVector<NamedDecl *, 4> ToParams;
2239   ToParams.reserve(Params->size());
2240   for (TemplateParameterList::iterator P = Params->begin(),
2241                                     PEnd = Params->end();
2242        P != PEnd; ++P) {
2243     Decl *To = Importer.Import(*P);
2244     if (!To)
2245       return nullptr;
2246
2247     ToParams.push_back(cast<NamedDecl>(To));
2248   }
2249
2250   return TemplateParameterList::Create(Importer.getToContext(),
2251                                        Importer.Import(Params->getTemplateLoc()),
2252                                        Importer.Import(Params->getLAngleLoc()),
2253                                        ToParams,
2254                                        Importer.Import(Params->getRAngleLoc()));
2255 }
2256
2257 TemplateArgument
2258 ASTNodeImporter::ImportTemplateArgument(const TemplateArgument &From) {
2259   switch (From.getKind()) {
2260   case TemplateArgument::Null:
2261     return TemplateArgument();
2262
2263   case TemplateArgument::Type: {
2264     QualType ToType = Importer.Import(From.getAsType());
2265     if (ToType.isNull())
2266       return TemplateArgument();
2267     return TemplateArgument(ToType);
2268   }
2269
2270   case TemplateArgument::Integral: {
2271     QualType ToType = Importer.Import(From.getIntegralType());
2272     if (ToType.isNull())
2273       return TemplateArgument();
2274     return TemplateArgument(From, ToType);
2275   }
2276
2277   case TemplateArgument::Declaration: {
2278     ValueDecl *To = cast_or_null<ValueDecl>(Importer.Import(From.getAsDecl()));
2279     QualType ToType = Importer.Import(From.getParamTypeForDecl());
2280     if (!To || ToType.isNull())
2281       return TemplateArgument();
2282     return TemplateArgument(To, ToType);
2283   }
2284
2285   case TemplateArgument::NullPtr: {
2286     QualType ToType = Importer.Import(From.getNullPtrType());
2287     if (ToType.isNull())
2288       return TemplateArgument();
2289     return TemplateArgument(ToType, /*isNullPtr*/true);
2290   }
2291
2292   case TemplateArgument::Template: {
2293     TemplateName ToTemplate = Importer.Import(From.getAsTemplate());
2294     if (ToTemplate.isNull())
2295       return TemplateArgument();
2296
2297     return TemplateArgument(ToTemplate);
2298   }
2299
2300   case TemplateArgument::TemplateExpansion: {
2301     TemplateName ToTemplate
2302       = Importer.Import(From.getAsTemplateOrTemplatePattern());
2303     if (ToTemplate.isNull())
2304       return TemplateArgument();
2305
2306     return TemplateArgument(ToTemplate, From.getNumTemplateExpansions());
2307   }
2308
2309   case TemplateArgument::Expression:
2310     if (Expr *ToExpr = Importer.Import(From.getAsExpr()))
2311       return TemplateArgument(ToExpr);
2312     return TemplateArgument();
2313
2314   case TemplateArgument::Pack: {
2315     SmallVector<TemplateArgument, 2> ToPack;
2316     ToPack.reserve(From.pack_size());
2317     if (ImportTemplateArguments(From.pack_begin(), From.pack_size(), ToPack))
2318       return TemplateArgument();
2319
2320     return TemplateArgument(
2321         llvm::makeArrayRef(ToPack).copy(Importer.getToContext()));
2322   }
2323   }
2324
2325   llvm_unreachable("Invalid template argument kind");
2326 }
2327
2328 bool ASTNodeImporter::ImportTemplateArguments(const TemplateArgument *FromArgs,
2329                                               unsigned NumFromArgs,
2330                               SmallVectorImpl<TemplateArgument> &ToArgs) {
2331   for (unsigned I = 0; I != NumFromArgs; ++I) {
2332     TemplateArgument To = ImportTemplateArgument(FromArgs[I]);
2333     if (To.isNull() && !FromArgs[I].isNull())
2334       return true;
2335
2336     ToArgs.push_back(To);
2337   }
2338
2339   return false;
2340 }
2341
2342 bool ASTNodeImporter::IsStructuralMatch(RecordDecl *FromRecord,
2343                                         RecordDecl *ToRecord, bool Complain) {
2344   // Eliminate a potential failure point where we attempt to re-import
2345   // something we're trying to import while completing ToRecord.
2346   Decl *ToOrigin = Importer.GetOriginalDecl(ToRecord);
2347   if (ToOrigin) {
2348     RecordDecl *ToOriginRecord = dyn_cast<RecordDecl>(ToOrigin);
2349     if (ToOriginRecord)
2350       ToRecord = ToOriginRecord;
2351   }
2352
2353   StructuralEquivalenceContext Ctx(Importer.getFromContext(),
2354                                    ToRecord->getASTContext(),
2355                                    Importer.getNonEquivalentDecls(),
2356                                    false, Complain);
2357   return Ctx.IsStructurallyEquivalent(FromRecord, ToRecord);
2358 }
2359
2360 bool ASTNodeImporter::IsStructuralMatch(VarDecl *FromVar, VarDecl *ToVar,
2361                                         bool Complain) {
2362   StructuralEquivalenceContext Ctx(
2363       Importer.getFromContext(), Importer.getToContext(),
2364       Importer.getNonEquivalentDecls(), false, Complain);
2365   return Ctx.IsStructurallyEquivalent(FromVar, ToVar);
2366 }
2367
2368 bool ASTNodeImporter::IsStructuralMatch(EnumDecl *FromEnum, EnumDecl *ToEnum) {
2369   StructuralEquivalenceContext Ctx(Importer.getFromContext(),
2370                                    Importer.getToContext(),
2371                                    Importer.getNonEquivalentDecls());
2372   return Ctx.IsStructurallyEquivalent(FromEnum, ToEnum);
2373 }
2374
2375 bool ASTNodeImporter::IsStructuralMatch(EnumConstantDecl *FromEC,
2376                                         EnumConstantDecl *ToEC)
2377 {
2378   const llvm::APSInt &FromVal = FromEC->getInitVal();
2379   const llvm::APSInt &ToVal = ToEC->getInitVal();
2380
2381   return FromVal.isSigned() == ToVal.isSigned() &&
2382          FromVal.getBitWidth() == ToVal.getBitWidth() &&
2383          FromVal == ToVal;
2384 }
2385
2386 bool ASTNodeImporter::IsStructuralMatch(ClassTemplateDecl *From,
2387                                         ClassTemplateDecl *To) {
2388   StructuralEquivalenceContext Ctx(Importer.getFromContext(),
2389                                    Importer.getToContext(),
2390                                    Importer.getNonEquivalentDecls());
2391   return Ctx.IsStructurallyEquivalent(From, To);
2392 }
2393
2394 bool ASTNodeImporter::IsStructuralMatch(VarTemplateDecl *From,
2395                                         VarTemplateDecl *To) {
2396   StructuralEquivalenceContext Ctx(Importer.getFromContext(),
2397                                    Importer.getToContext(),
2398                                    Importer.getNonEquivalentDecls());
2399   return Ctx.IsStructurallyEquivalent(From, To);
2400 }
2401
2402 Decl *ASTNodeImporter::VisitDecl(Decl *D) {
2403   Importer.FromDiag(D->getLocation(), diag::err_unsupported_ast_node)
2404     << D->getDeclKindName();
2405   return nullptr;
2406 }
2407
2408 Decl *ASTNodeImporter::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
2409   TranslationUnitDecl *ToD =
2410     Importer.getToContext().getTranslationUnitDecl();
2411
2412   Importer.Imported(D, ToD);
2413
2414   return ToD;
2415 }
2416
2417 Decl *ASTNodeImporter::VisitAccessSpecDecl(AccessSpecDecl *D) {
2418
2419   SourceLocation Loc = Importer.Import(D->getLocation());
2420   SourceLocation ColonLoc = Importer.Import(D->getColonLoc());
2421
2422   // Import the context of this declaration.
2423   DeclContext *DC = Importer.ImportContext(D->getDeclContext());
2424   if (!DC)
2425     return nullptr;
2426
2427   AccessSpecDecl *accessSpecDecl
2428     = AccessSpecDecl::Create(Importer.getToContext(), D->getAccess(),
2429                              DC, Loc, ColonLoc);
2430
2431   if (!accessSpecDecl)
2432     return nullptr;
2433
2434   // Lexical DeclContext and Semantic DeclContext
2435   // is always the same for the accessSpec.
2436   accessSpecDecl->setLexicalDeclContext(DC);
2437   DC->addDeclInternal(accessSpecDecl);
2438
2439   return accessSpecDecl;
2440 }
2441
2442 Decl *ASTNodeImporter::VisitNamespaceDecl(NamespaceDecl *D) {
2443   // Import the major distinguishing characteristics of this namespace.
2444   DeclContext *DC, *LexicalDC;
2445   DeclarationName Name;
2446   SourceLocation Loc;
2447   NamedDecl *ToD;
2448   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
2449     return nullptr;
2450   if (ToD)
2451     return ToD;
2452
2453   NamespaceDecl *MergeWithNamespace = nullptr;
2454   if (!Name) {
2455     // This is an anonymous namespace. Adopt an existing anonymous
2456     // namespace if we can.
2457     // FIXME: Not testable.
2458     if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(DC))
2459       MergeWithNamespace = TU->getAnonymousNamespace();
2460     else
2461       MergeWithNamespace = cast<NamespaceDecl>(DC)->getAnonymousNamespace();
2462   } else {
2463     SmallVector<NamedDecl *, 4> ConflictingDecls;
2464     SmallVector<NamedDecl *, 2> FoundDecls;
2465     DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
2466     for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
2467       if (!FoundDecls[I]->isInIdentifierNamespace(Decl::IDNS_Namespace))
2468         continue;
2469
2470       if (NamespaceDecl *FoundNS = dyn_cast<NamespaceDecl>(FoundDecls[I])) {
2471         MergeWithNamespace = FoundNS;
2472         ConflictingDecls.clear();
2473         break;
2474       }
2475
2476       ConflictingDecls.push_back(FoundDecls[I]);
2477     }
2478
2479     if (!ConflictingDecls.empty()) {
2480       Name = Importer.HandleNameConflict(Name, DC, Decl::IDNS_Namespace,
2481                                          ConflictingDecls.data(),
2482                                          ConflictingDecls.size());
2483     }
2484   }
2485
2486   // Create the "to" namespace, if needed.
2487   NamespaceDecl *ToNamespace = MergeWithNamespace;
2488   if (!ToNamespace) {
2489     ToNamespace = NamespaceDecl::Create(Importer.getToContext(), DC,
2490                                         D->isInline(),
2491                                         Importer.Import(D->getLocStart()),
2492                                         Loc, Name.getAsIdentifierInfo(),
2493                                         /*PrevDecl=*/nullptr);
2494     ToNamespace->setLexicalDeclContext(LexicalDC);
2495     LexicalDC->addDeclInternal(ToNamespace);
2496
2497     // If this is an anonymous namespace, register it as the anonymous
2498     // namespace within its context.
2499     if (!Name) {
2500       if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(DC))
2501         TU->setAnonymousNamespace(ToNamespace);
2502       else
2503         cast<NamespaceDecl>(DC)->setAnonymousNamespace(ToNamespace);
2504     }
2505   }
2506   Importer.Imported(D, ToNamespace);
2507
2508   ImportDeclContext(D);
2509
2510   return ToNamespace;
2511 }
2512
2513 Decl *ASTNodeImporter::VisitTypedefNameDecl(TypedefNameDecl *D, bool IsAlias) {
2514   // Import the major distinguishing characteristics of this typedef.
2515   DeclContext *DC, *LexicalDC;
2516   DeclarationName Name;
2517   SourceLocation Loc;
2518   NamedDecl *ToD;
2519   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
2520     return nullptr;
2521   if (ToD)
2522     return ToD;
2523
2524   // If this typedef is not in block scope, determine whether we've
2525   // seen a typedef with the same name (that we can merge with) or any
2526   // other entity by that name (which name lookup could conflict with).
2527   if (!DC->isFunctionOrMethod()) {
2528     SmallVector<NamedDecl *, 4> ConflictingDecls;
2529     unsigned IDNS = Decl::IDNS_Ordinary;
2530     SmallVector<NamedDecl *, 2> FoundDecls;
2531     DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
2532     for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
2533       if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
2534         continue;
2535       if (TypedefNameDecl *FoundTypedef =
2536             dyn_cast<TypedefNameDecl>(FoundDecls[I])) {
2537         if (Importer.IsStructurallyEquivalent(D->getUnderlyingType(),
2538                                             FoundTypedef->getUnderlyingType()))
2539           return Importer.Imported(D, FoundTypedef);
2540       }
2541
2542       ConflictingDecls.push_back(FoundDecls[I]);
2543     }
2544
2545     if (!ConflictingDecls.empty()) {
2546       Name = Importer.HandleNameConflict(Name, DC, IDNS,
2547                                          ConflictingDecls.data(),
2548                                          ConflictingDecls.size());
2549       if (!Name)
2550         return nullptr;
2551     }
2552   }
2553
2554   // Import the underlying type of this typedef;
2555   QualType T = Importer.Import(D->getUnderlyingType());
2556   if (T.isNull())
2557     return nullptr;
2558
2559   // Create the new typedef node.
2560   TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
2561   SourceLocation StartL = Importer.Import(D->getLocStart());
2562   TypedefNameDecl *ToTypedef;
2563   if (IsAlias)
2564     ToTypedef = TypeAliasDecl::Create(Importer.getToContext(), DC,
2565                                       StartL, Loc,
2566                                       Name.getAsIdentifierInfo(),
2567                                       TInfo);
2568   else
2569     ToTypedef = TypedefDecl::Create(Importer.getToContext(), DC,
2570                                     StartL, Loc,
2571                                     Name.getAsIdentifierInfo(),
2572                                     TInfo);
2573
2574   ToTypedef->setAccess(D->getAccess());
2575   ToTypedef->setLexicalDeclContext(LexicalDC);
2576   Importer.Imported(D, ToTypedef);
2577   LexicalDC->addDeclInternal(ToTypedef);
2578
2579   return ToTypedef;
2580 }
2581
2582 Decl *ASTNodeImporter::VisitTypedefDecl(TypedefDecl *D) {
2583   return VisitTypedefNameDecl(D, /*IsAlias=*/false);
2584 }
2585
2586 Decl *ASTNodeImporter::VisitTypeAliasDecl(TypeAliasDecl *D) {
2587   return VisitTypedefNameDecl(D, /*IsAlias=*/true);
2588 }
2589
2590 Decl *ASTNodeImporter::VisitLabelDecl(LabelDecl *D) {
2591   // Import the major distinguishing characteristics of this label.
2592   DeclContext *DC, *LexicalDC;
2593   DeclarationName Name;
2594   SourceLocation Loc;
2595   NamedDecl *ToD;
2596   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
2597     return nullptr;
2598   if (ToD)
2599     return ToD;
2600
2601   assert(LexicalDC->isFunctionOrMethod());
2602
2603   LabelDecl *ToLabel = D->isGnuLocal()
2604       ? LabelDecl::Create(Importer.getToContext(),
2605                           DC, Importer.Import(D->getLocation()),
2606                           Name.getAsIdentifierInfo(),
2607                           Importer.Import(D->getLocStart()))
2608       : LabelDecl::Create(Importer.getToContext(),
2609                           DC, Importer.Import(D->getLocation()),
2610                           Name.getAsIdentifierInfo());
2611   Importer.Imported(D, ToLabel);
2612
2613   LabelStmt *Label = cast_or_null<LabelStmt>(Importer.Import(D->getStmt()));
2614   if (!Label)
2615     return nullptr;
2616
2617   ToLabel->setStmt(Label);
2618   ToLabel->setLexicalDeclContext(LexicalDC);
2619   LexicalDC->addDeclInternal(ToLabel);
2620   return ToLabel;
2621 }
2622
2623 Decl *ASTNodeImporter::VisitEnumDecl(EnumDecl *D) {
2624   // Import the major distinguishing characteristics of this enum.
2625   DeclContext *DC, *LexicalDC;
2626   DeclarationName Name;
2627   SourceLocation Loc;
2628   NamedDecl *ToD;
2629   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
2630     return nullptr;
2631   if (ToD)
2632     return ToD;
2633
2634   // Figure out what enum name we're looking for.
2635   unsigned IDNS = Decl::IDNS_Tag;
2636   DeclarationName SearchName = Name;
2637   if (!SearchName && D->getTypedefNameForAnonDecl()) {
2638     SearchName = Importer.Import(D->getTypedefNameForAnonDecl()->getDeclName());
2639     IDNS = Decl::IDNS_Ordinary;
2640   } else if (Importer.getToContext().getLangOpts().CPlusPlus)
2641     IDNS |= Decl::IDNS_Ordinary;
2642
2643   // We may already have an enum of the same name; try to find and match it.
2644   if (!DC->isFunctionOrMethod() && SearchName) {
2645     SmallVector<NamedDecl *, 4> ConflictingDecls;
2646     SmallVector<NamedDecl *, 2> FoundDecls;
2647     DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
2648     for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
2649       if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
2650         continue;
2651
2652       Decl *Found = FoundDecls[I];
2653       if (TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Found)) {
2654         if (const TagType *Tag = Typedef->getUnderlyingType()->getAs<TagType>())
2655           Found = Tag->getDecl();
2656       }
2657
2658       if (EnumDecl *FoundEnum = dyn_cast<EnumDecl>(Found)) {
2659         if (IsStructuralMatch(D, FoundEnum))
2660           return Importer.Imported(D, FoundEnum);
2661       }
2662
2663       ConflictingDecls.push_back(FoundDecls[I]);
2664     }
2665
2666     if (!ConflictingDecls.empty()) {
2667       Name = Importer.HandleNameConflict(Name, DC, IDNS,
2668                                          ConflictingDecls.data(),
2669                                          ConflictingDecls.size());
2670     }
2671   }
2672
2673   // Create the enum declaration.
2674   EnumDecl *D2 = EnumDecl::Create(Importer.getToContext(), DC,
2675                                   Importer.Import(D->getLocStart()),
2676                                   Loc, Name.getAsIdentifierInfo(), nullptr,
2677                                   D->isScoped(), D->isScopedUsingClassTag(),
2678                                   D->isFixed());
2679   // Import the qualifier, if any.
2680   D2->setQualifierInfo(Importer.Import(D->getQualifierLoc()));
2681   D2->setAccess(D->getAccess());
2682   D2->setLexicalDeclContext(LexicalDC);
2683   Importer.Imported(D, D2);
2684   LexicalDC->addDeclInternal(D2);
2685
2686   // Import the integer type.
2687   QualType ToIntegerType = Importer.Import(D->getIntegerType());
2688   if (ToIntegerType.isNull())
2689     return nullptr;
2690   D2->setIntegerType(ToIntegerType);
2691
2692   // Import the definition
2693   if (D->isCompleteDefinition() && ImportDefinition(D, D2))
2694     return nullptr;
2695
2696   return D2;
2697 }
2698
2699 Decl *ASTNodeImporter::VisitRecordDecl(RecordDecl *D) {
2700   // If this record has a definition in the translation unit we're coming from,
2701   // but this particular declaration is not that definition, import the
2702   // definition and map to that.
2703   TagDecl *Definition = D->getDefinition();
2704   if (Definition && Definition != D) {
2705     Decl *ImportedDef = Importer.Import(Definition);
2706     if (!ImportedDef)
2707       return nullptr;
2708
2709     return Importer.Imported(D, ImportedDef);
2710   }
2711
2712   // Import the major distinguishing characteristics of this record.
2713   DeclContext *DC, *LexicalDC;
2714   DeclarationName Name;
2715   SourceLocation Loc;
2716   NamedDecl *ToD;
2717   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
2718     return nullptr;
2719   if (ToD)
2720     return ToD;
2721
2722   // Figure out what structure name we're looking for.
2723   unsigned IDNS = Decl::IDNS_Tag;
2724   DeclarationName SearchName = Name;
2725   if (!SearchName && D->getTypedefNameForAnonDecl()) {
2726     SearchName = Importer.Import(D->getTypedefNameForAnonDecl()->getDeclName());
2727     IDNS = Decl::IDNS_Ordinary;
2728   } else if (Importer.getToContext().getLangOpts().CPlusPlus)
2729     IDNS |= Decl::IDNS_Ordinary;
2730
2731   // We may already have a record of the same name; try to find and match it.
2732   RecordDecl *AdoptDecl = nullptr;
2733   if (!DC->isFunctionOrMethod()) {
2734     SmallVector<NamedDecl *, 4> ConflictingDecls;
2735     SmallVector<NamedDecl *, 2> FoundDecls;
2736     DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
2737     for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
2738       if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
2739         continue;
2740
2741       Decl *Found = FoundDecls[I];
2742       if (TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Found)) {
2743         if (const TagType *Tag = Typedef->getUnderlyingType()->getAs<TagType>())
2744           Found = Tag->getDecl();
2745       }
2746
2747       if (RecordDecl *FoundRecord = dyn_cast<RecordDecl>(Found)) {
2748         if (D->isAnonymousStructOrUnion() &&
2749             FoundRecord->isAnonymousStructOrUnion()) {
2750           // If both anonymous structs/unions are in a record context, make sure
2751           // they occur in the same location in the context records.
2752           if (Optional<unsigned> Index1
2753               = findAnonymousStructOrUnionIndex(D)) {
2754             if (Optional<unsigned> Index2 =
2755                     findAnonymousStructOrUnionIndex(FoundRecord)) {
2756               if (*Index1 != *Index2)
2757                 continue;
2758             }
2759           }
2760         }
2761
2762         if (RecordDecl *FoundDef = FoundRecord->getDefinition()) {
2763           if ((SearchName && !D->isCompleteDefinition())
2764               || (D->isCompleteDefinition() &&
2765                   D->isAnonymousStructOrUnion()
2766                     == FoundDef->isAnonymousStructOrUnion() &&
2767                   IsStructuralMatch(D, FoundDef))) {
2768             // The record types structurally match, or the "from" translation
2769             // unit only had a forward declaration anyway; call it the same
2770             // function.
2771             // FIXME: For C++, we should also merge methods here.
2772             return Importer.Imported(D, FoundDef);
2773           }
2774         } else if (!D->isCompleteDefinition()) {
2775           // We have a forward declaration of this type, so adopt that forward
2776           // declaration rather than building a new one.
2777
2778           // If one or both can be completed from external storage then try one
2779           // last time to complete and compare them before doing this.
2780
2781           if (FoundRecord->hasExternalLexicalStorage() &&
2782               !FoundRecord->isCompleteDefinition())
2783             FoundRecord->getASTContext().getExternalSource()->CompleteType(FoundRecord);
2784           if (D->hasExternalLexicalStorage())
2785             D->getASTContext().getExternalSource()->CompleteType(D);
2786
2787           if (FoundRecord->isCompleteDefinition() &&
2788               D->isCompleteDefinition() &&
2789               !IsStructuralMatch(D, FoundRecord))
2790             continue;
2791
2792           AdoptDecl = FoundRecord;
2793           continue;
2794         } else if (!SearchName) {
2795           continue;
2796         }
2797       }
2798
2799       ConflictingDecls.push_back(FoundDecls[I]);
2800     }
2801
2802     if (!ConflictingDecls.empty() && SearchName) {
2803       Name = Importer.HandleNameConflict(Name, DC, IDNS,
2804                                          ConflictingDecls.data(),
2805                                          ConflictingDecls.size());
2806     }
2807   }
2808
2809   // Create the record declaration.
2810   RecordDecl *D2 = AdoptDecl;
2811   SourceLocation StartLoc = Importer.Import(D->getLocStart());
2812   if (!D2) {
2813     CXXRecordDecl *D2CXX = nullptr;
2814     if (CXXRecordDecl *DCXX = llvm::dyn_cast<CXXRecordDecl>(D)) {
2815       if (DCXX->isLambda()) {
2816         TypeSourceInfo *TInfo = Importer.Import(DCXX->getLambdaTypeInfo());
2817         D2CXX = CXXRecordDecl::CreateLambda(Importer.getToContext(),
2818                                             DC, TInfo, Loc,
2819                                             DCXX->isDependentLambda(),
2820                                             DCXX->isGenericLambda(),
2821                                             DCXX->getLambdaCaptureDefault());
2822         Decl *CDecl = Importer.Import(DCXX->getLambdaContextDecl());
2823         if (DCXX->getLambdaContextDecl() && !CDecl)
2824           return nullptr;
2825         D2CXX->setLambdaMangling(DCXX->getLambdaManglingNumber(), CDecl);
2826       } else if (DCXX->isInjectedClassName()) {
2827         // We have to be careful to do a similar dance to the one in
2828         // Sema::ActOnStartCXXMemberDeclarations
2829         CXXRecordDecl *const PrevDecl = nullptr;
2830         const bool DelayTypeCreation = true;
2831         D2CXX = CXXRecordDecl::Create(
2832             Importer.getToContext(), D->getTagKind(), DC, StartLoc, Loc,
2833             Name.getAsIdentifierInfo(), PrevDecl, DelayTypeCreation);
2834         Importer.getToContext().getTypeDeclType(
2835             D2CXX, llvm::dyn_cast<CXXRecordDecl>(DC));
2836       } else {
2837         D2CXX = CXXRecordDecl::Create(Importer.getToContext(),
2838                                       D->getTagKind(),
2839                                       DC, StartLoc, Loc,
2840                                       Name.getAsIdentifierInfo());
2841       }
2842       D2 = D2CXX;
2843       D2->setAccess(D->getAccess());
2844     } else {
2845       D2 = RecordDecl::Create(Importer.getToContext(), D->getTagKind(),
2846                               DC, StartLoc, Loc, Name.getAsIdentifierInfo());
2847     }
2848
2849     D2->setQualifierInfo(Importer.Import(D->getQualifierLoc()));
2850     D2->setLexicalDeclContext(LexicalDC);
2851     LexicalDC->addDeclInternal(D2);
2852     if (D->isAnonymousStructOrUnion())
2853       D2->setAnonymousStructOrUnion(true);
2854   }
2855
2856   Importer.Imported(D, D2);
2857
2858   if (D->isCompleteDefinition() && ImportDefinition(D, D2, IDK_Default))
2859     return nullptr;
2860
2861   return D2;
2862 }
2863
2864 Decl *ASTNodeImporter::VisitEnumConstantDecl(EnumConstantDecl *D) {
2865   // Import the major distinguishing characteristics of this enumerator.
2866   DeclContext *DC, *LexicalDC;
2867   DeclarationName Name;
2868   SourceLocation Loc;
2869   NamedDecl *ToD;
2870   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
2871     return nullptr;
2872   if (ToD)
2873     return ToD;
2874
2875   QualType T = Importer.Import(D->getType());
2876   if (T.isNull())
2877     return nullptr;
2878
2879   // Determine whether there are any other declarations with the same name and
2880   // in the same context.
2881   if (!LexicalDC->isFunctionOrMethod()) {
2882     SmallVector<NamedDecl *, 4> ConflictingDecls;
2883     unsigned IDNS = Decl::IDNS_Ordinary;
2884     SmallVector<NamedDecl *, 2> FoundDecls;
2885     DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
2886     for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
2887       if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
2888         continue;
2889
2890       if (EnumConstantDecl *FoundEnumConstant
2891             = dyn_cast<EnumConstantDecl>(FoundDecls[I])) {
2892         if (IsStructuralMatch(D, FoundEnumConstant))
2893           return Importer.Imported(D, FoundEnumConstant);
2894       }
2895
2896       ConflictingDecls.push_back(FoundDecls[I]);
2897     }
2898
2899     if (!ConflictingDecls.empty()) {
2900       Name = Importer.HandleNameConflict(Name, DC, IDNS,
2901                                          ConflictingDecls.data(),
2902                                          ConflictingDecls.size());
2903       if (!Name)
2904         return nullptr;
2905     }
2906   }
2907
2908   Expr *Init = Importer.Import(D->getInitExpr());
2909   if (D->getInitExpr() && !Init)
2910     return nullptr;
2911
2912   EnumConstantDecl *ToEnumerator
2913     = EnumConstantDecl::Create(Importer.getToContext(), cast<EnumDecl>(DC), Loc,
2914                                Name.getAsIdentifierInfo(), T,
2915                                Init, D->getInitVal());
2916   ToEnumerator->setAccess(D->getAccess());
2917   ToEnumerator->setLexicalDeclContext(LexicalDC);
2918   Importer.Imported(D, ToEnumerator);
2919   LexicalDC->addDeclInternal(ToEnumerator);
2920   return ToEnumerator;
2921 }
2922
2923 Decl *ASTNodeImporter::VisitFunctionDecl(FunctionDecl *D) {
2924   // Import the major distinguishing characteristics of this function.
2925   DeclContext *DC, *LexicalDC;
2926   DeclarationName Name;
2927   SourceLocation Loc;
2928   NamedDecl *ToD;
2929   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
2930     return nullptr;
2931   if (ToD)
2932     return ToD;
2933
2934   // Try to find a function in our own ("to") context with the same name, same
2935   // type, and in the same context as the function we're importing.
2936   if (!LexicalDC->isFunctionOrMethod()) {
2937     SmallVector<NamedDecl *, 4> ConflictingDecls;
2938     unsigned IDNS = Decl::IDNS_Ordinary;
2939     SmallVector<NamedDecl *, 2> FoundDecls;
2940     DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
2941     for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
2942       if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
2943         continue;
2944
2945       if (FunctionDecl *FoundFunction = dyn_cast<FunctionDecl>(FoundDecls[I])) {
2946         if (FoundFunction->hasExternalFormalLinkage() &&
2947             D->hasExternalFormalLinkage()) {
2948           if (Importer.IsStructurallyEquivalent(D->getType(),
2949                                                 FoundFunction->getType())) {
2950             // FIXME: Actually try to merge the body and other attributes.
2951             return Importer.Imported(D, FoundFunction);
2952           }
2953
2954           // FIXME: Check for overloading more carefully, e.g., by boosting
2955           // Sema::IsOverload out to the AST library.
2956
2957           // Function overloading is okay in C++.
2958           if (Importer.getToContext().getLangOpts().CPlusPlus)
2959             continue;
2960
2961           // Complain about inconsistent function types.
2962           Importer.ToDiag(Loc, diag::err_odr_function_type_inconsistent)
2963             << Name << D->getType() << FoundFunction->getType();
2964           Importer.ToDiag(FoundFunction->getLocation(),
2965                           diag::note_odr_value_here)
2966             << FoundFunction->getType();
2967         }
2968       }
2969
2970       ConflictingDecls.push_back(FoundDecls[I]);
2971     }
2972
2973     if (!ConflictingDecls.empty()) {
2974       Name = Importer.HandleNameConflict(Name, DC, IDNS,
2975                                          ConflictingDecls.data(),
2976                                          ConflictingDecls.size());
2977       if (!Name)
2978         return nullptr;
2979     }
2980   }
2981
2982   DeclarationNameInfo NameInfo(Name, Loc);
2983   // Import additional name location/type info.
2984   ImportDeclarationNameLoc(D->getNameInfo(), NameInfo);
2985
2986   QualType FromTy = D->getType();
2987   bool usedDifferentExceptionSpec = false;
2988
2989   if (const FunctionProtoType *
2990         FromFPT = D->getType()->getAs<FunctionProtoType>()) {
2991     FunctionProtoType::ExtProtoInfo FromEPI = FromFPT->getExtProtoInfo();
2992     // FunctionProtoType::ExtProtoInfo's ExceptionSpecDecl can point to the
2993     // FunctionDecl that we are importing the FunctionProtoType for.
2994     // To avoid an infinite recursion when importing, create the FunctionDecl
2995     // with a simplified function type and update it afterwards.
2996     if (FromEPI.ExceptionSpec.SourceDecl ||
2997         FromEPI.ExceptionSpec.SourceTemplate ||
2998         FromEPI.ExceptionSpec.NoexceptExpr) {
2999       FunctionProtoType::ExtProtoInfo DefaultEPI;
3000       FromTy = Importer.getFromContext().getFunctionType(
3001           FromFPT->getReturnType(), FromFPT->getParamTypes(), DefaultEPI);
3002       usedDifferentExceptionSpec = true;
3003     }
3004   }
3005
3006   // Import the type.
3007   QualType T = Importer.Import(FromTy);
3008   if (T.isNull())
3009     return nullptr;
3010
3011   // Import the function parameters.
3012   SmallVector<ParmVarDecl *, 8> Parameters;
3013   for (auto P : D->parameters()) {
3014     ParmVarDecl *ToP = cast_or_null<ParmVarDecl>(Importer.Import(P));
3015     if (!ToP)
3016       return nullptr;
3017
3018     Parameters.push_back(ToP);
3019   }
3020
3021   // Create the imported function.
3022   TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
3023   FunctionDecl *ToFunction = nullptr;
3024   SourceLocation InnerLocStart = Importer.Import(D->getInnerLocStart());
3025   if (CXXConstructorDecl *FromConstructor = dyn_cast<CXXConstructorDecl>(D)) {
3026     ToFunction = CXXConstructorDecl::Create(Importer.getToContext(),
3027                                             cast<CXXRecordDecl>(DC),
3028                                             InnerLocStart,
3029                                             NameInfo, T, TInfo,
3030                                             FromConstructor->isExplicit(),
3031                                             D->isInlineSpecified(),
3032                                             D->isImplicit(),
3033                                             D->isConstexpr());
3034     if (unsigned NumInitializers = FromConstructor->getNumCtorInitializers()) {
3035       SmallVector<CXXCtorInitializer *, 4> CtorInitializers;
3036       for (CXXCtorInitializer *I : FromConstructor->inits()) {
3037         CXXCtorInitializer *ToI =
3038             cast_or_null<CXXCtorInitializer>(Importer.Import(I));
3039         if (!ToI && I)
3040           return nullptr;
3041         CtorInitializers.push_back(ToI);
3042       }
3043       CXXCtorInitializer **Memory =
3044           new (Importer.getToContext()) CXXCtorInitializer *[NumInitializers];
3045       std::copy(CtorInitializers.begin(), CtorInitializers.end(), Memory);
3046       CXXConstructorDecl *ToCtor = llvm::cast<CXXConstructorDecl>(ToFunction);
3047       ToCtor->setCtorInitializers(Memory);
3048       ToCtor->setNumCtorInitializers(NumInitializers);
3049     }
3050   } else if (isa<CXXDestructorDecl>(D)) {
3051     ToFunction = CXXDestructorDecl::Create(Importer.getToContext(),
3052                                            cast<CXXRecordDecl>(DC),
3053                                            InnerLocStart,
3054                                            NameInfo, T, TInfo,
3055                                            D->isInlineSpecified(),
3056                                            D->isImplicit());
3057   } else if (CXXConversionDecl *FromConversion
3058                                            = dyn_cast<CXXConversionDecl>(D)) {
3059     ToFunction = CXXConversionDecl::Create(Importer.getToContext(),
3060                                            cast<CXXRecordDecl>(DC),
3061                                            InnerLocStart,
3062                                            NameInfo, T, TInfo,
3063                                            D->isInlineSpecified(),
3064                                            FromConversion->isExplicit(),
3065                                            D->isConstexpr(),
3066                                            Importer.Import(D->getLocEnd()));
3067   } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
3068     ToFunction = CXXMethodDecl::Create(Importer.getToContext(),
3069                                        cast<CXXRecordDecl>(DC),
3070                                        InnerLocStart,
3071                                        NameInfo, T, TInfo,
3072                                        Method->getStorageClass(),
3073                                        Method->isInlineSpecified(),
3074                                        D->isConstexpr(),
3075                                        Importer.Import(D->getLocEnd()));
3076   } else {
3077     ToFunction = FunctionDecl::Create(Importer.getToContext(), DC,
3078                                       InnerLocStart,
3079                                       NameInfo, T, TInfo, D->getStorageClass(),
3080                                       D->isInlineSpecified(),
3081                                       D->hasWrittenPrototype(),
3082                                       D->isConstexpr());
3083   }
3084
3085   // Import the qualifier, if any.
3086   ToFunction->setQualifierInfo(Importer.Import(D->getQualifierLoc()));
3087   ToFunction->setAccess(D->getAccess());
3088   ToFunction->setLexicalDeclContext(LexicalDC);
3089   ToFunction->setVirtualAsWritten(D->isVirtualAsWritten());
3090   ToFunction->setTrivial(D->isTrivial());
3091   ToFunction->setPure(D->isPure());
3092   Importer.Imported(D, ToFunction);
3093
3094   // Set the parameters.
3095   for (unsigned I = 0, N = Parameters.size(); I != N; ++I) {
3096     Parameters[I]->setOwningFunction(ToFunction);
3097     ToFunction->addDeclInternal(Parameters[I]);
3098   }
3099   ToFunction->setParams(Parameters);
3100
3101   if (usedDifferentExceptionSpec) {
3102     // Update FunctionProtoType::ExtProtoInfo.
3103     QualType T = Importer.Import(D->getType());
3104     if (T.isNull())
3105       return nullptr;
3106     ToFunction->setType(T);
3107   }
3108
3109   // Import the body, if any.
3110   if (Stmt *FromBody = D->getBody()) {
3111     if (Stmt *ToBody = Importer.Import(FromBody)) {
3112       ToFunction->setBody(ToBody);
3113     }
3114   }
3115
3116   // FIXME: Other bits to merge?
3117
3118   // Add this function to the lexical context.
3119   LexicalDC->addDeclInternal(ToFunction);
3120
3121   return ToFunction;
3122 }
3123
3124 Decl *ASTNodeImporter::VisitCXXMethodDecl(CXXMethodDecl *D) {
3125   return VisitFunctionDecl(D);
3126 }
3127
3128 Decl *ASTNodeImporter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
3129   return VisitCXXMethodDecl(D);
3130 }
3131
3132 Decl *ASTNodeImporter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
3133   return VisitCXXMethodDecl(D);
3134 }
3135
3136 Decl *ASTNodeImporter::VisitCXXConversionDecl(CXXConversionDecl *D) {
3137   return VisitCXXMethodDecl(D);
3138 }
3139
3140 static unsigned getFieldIndex(Decl *F) {
3141   RecordDecl *Owner = dyn_cast<RecordDecl>(F->getDeclContext());
3142   if (!Owner)
3143     return 0;
3144
3145   unsigned Index = 1;
3146   for (const auto *D : Owner->noload_decls()) {
3147     if (D == F)
3148       return Index;
3149
3150     if (isa<FieldDecl>(*D) || isa<IndirectFieldDecl>(*D))
3151       ++Index;
3152   }
3153
3154   return Index;
3155 }
3156
3157 Decl *ASTNodeImporter::VisitFieldDecl(FieldDecl *D) {
3158   // Import the major distinguishing characteristics of a variable.
3159   DeclContext *DC, *LexicalDC;
3160   DeclarationName Name;
3161   SourceLocation Loc;
3162   NamedDecl *ToD;
3163   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
3164     return nullptr;
3165   if (ToD)
3166     return ToD;
3167
3168   // Determine whether we've already imported this field.
3169   SmallVector<NamedDecl *, 2> FoundDecls;
3170   DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
3171   for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
3172     if (FieldDecl *FoundField = dyn_cast<FieldDecl>(FoundDecls[I])) {
3173       // For anonymous fields, match up by index.
3174       if (!Name && getFieldIndex(D) != getFieldIndex(FoundField))
3175         continue;
3176
3177       if (Importer.IsStructurallyEquivalent(D->getType(),
3178                                             FoundField->getType())) {
3179         Importer.Imported(D, FoundField);
3180         return FoundField;
3181       }
3182
3183       Importer.ToDiag(Loc, diag::err_odr_field_type_inconsistent)
3184         << Name << D->getType() << FoundField->getType();
3185       Importer.ToDiag(FoundField->getLocation(), diag::note_odr_value_here)
3186         << FoundField->getType();
3187       return nullptr;
3188     }
3189   }
3190
3191   // Import the type.
3192   QualType T = Importer.Import(D->getType());
3193   if (T.isNull())
3194     return nullptr;
3195
3196   TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
3197   Expr *BitWidth = Importer.Import(D->getBitWidth());
3198   if (!BitWidth && D->getBitWidth())
3199     return nullptr;
3200
3201   FieldDecl *ToField = FieldDecl::Create(Importer.getToContext(), DC,
3202                                          Importer.Import(D->getInnerLocStart()),
3203                                          Loc, Name.getAsIdentifierInfo(),
3204                                          T, TInfo, BitWidth, D->isMutable(),
3205                                          D->getInClassInitStyle());
3206   ToField->setAccess(D->getAccess());
3207   ToField->setLexicalDeclContext(LexicalDC);
3208   if (Expr *FromInitializer = D->getInClassInitializer()) {
3209     Expr *ToInitializer = Importer.Import(FromInitializer);
3210     if (ToInitializer)
3211       ToField->setInClassInitializer(ToInitializer);
3212     else
3213       return nullptr;
3214   }
3215   ToField->setImplicit(D->isImplicit());
3216   Importer.Imported(D, ToField);
3217   LexicalDC->addDeclInternal(ToField);
3218   return ToField;
3219 }
3220
3221 Decl *ASTNodeImporter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
3222   // Import the major distinguishing characteristics of a variable.
3223   DeclContext *DC, *LexicalDC;
3224   DeclarationName Name;
3225   SourceLocation Loc;
3226   NamedDecl *ToD;
3227   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
3228     return nullptr;
3229   if (ToD)
3230     return ToD;
3231
3232   // Determine whether we've already imported this field.
3233   SmallVector<NamedDecl *, 2> FoundDecls;
3234   DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
3235   for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
3236     if (IndirectFieldDecl *FoundField
3237                                 = dyn_cast<IndirectFieldDecl>(FoundDecls[I])) {
3238       // For anonymous indirect fields, match up by index.
3239       if (!Name && getFieldIndex(D) != getFieldIndex(FoundField))
3240         continue;
3241
3242       if (Importer.IsStructurallyEquivalent(D->getType(),
3243                                             FoundField->getType(),
3244                                             !Name.isEmpty())) {
3245         Importer.Imported(D, FoundField);
3246         return FoundField;
3247       }
3248
3249       // If there are more anonymous fields to check, continue.
3250       if (!Name && I < N-1)
3251         continue;
3252
3253       Importer.ToDiag(Loc, diag::err_odr_field_type_inconsistent)
3254         << Name << D->getType() << FoundField->getType();
3255       Importer.ToDiag(FoundField->getLocation(), diag::note_odr_value_here)
3256         << FoundField->getType();
3257       return nullptr;
3258     }
3259   }
3260
3261   // Import the type.
3262   QualType T = Importer.Import(D->getType());
3263   if (T.isNull())
3264     return nullptr;
3265
3266   NamedDecl **NamedChain =
3267     new (Importer.getToContext())NamedDecl*[D->getChainingSize()];
3268
3269   unsigned i = 0;
3270   for (auto *PI : D->chain()) {
3271     Decl *D = Importer.Import(PI);
3272     if (!D)
3273       return nullptr;
3274     NamedChain[i++] = cast<NamedDecl>(D);
3275   }
3276
3277   IndirectFieldDecl *ToIndirectField = IndirectFieldDecl::Create(
3278       Importer.getToContext(), DC, Loc, Name.getAsIdentifierInfo(), T,
3279       {NamedChain, D->getChainingSize()});
3280
3281   for (const auto *Attr : D->attrs())
3282     ToIndirectField->addAttr(Attr->clone(Importer.getToContext()));
3283
3284   ToIndirectField->setAccess(D->getAccess());
3285   ToIndirectField->setLexicalDeclContext(LexicalDC);
3286   Importer.Imported(D, ToIndirectField);
3287   LexicalDC->addDeclInternal(ToIndirectField);
3288   return ToIndirectField;
3289 }
3290
3291 Decl *ASTNodeImporter::VisitObjCIvarDecl(ObjCIvarDecl *D) {
3292   // Import the major distinguishing characteristics of an ivar.
3293   DeclContext *DC, *LexicalDC;
3294   DeclarationName Name;
3295   SourceLocation Loc;
3296   NamedDecl *ToD;
3297   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
3298     return nullptr;
3299   if (ToD)
3300     return ToD;
3301
3302   // Determine whether we've already imported this ivar
3303   SmallVector<NamedDecl *, 2> FoundDecls;
3304   DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
3305   for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
3306     if (ObjCIvarDecl *FoundIvar = dyn_cast<ObjCIvarDecl>(FoundDecls[I])) {
3307       if (Importer.IsStructurallyEquivalent(D->getType(),
3308                                             FoundIvar->getType())) {
3309         Importer.Imported(D, FoundIvar);
3310         return FoundIvar;
3311       }
3312
3313       Importer.ToDiag(Loc, diag::err_odr_ivar_type_inconsistent)
3314         << Name << D->getType() << FoundIvar->getType();
3315       Importer.ToDiag(FoundIvar->getLocation(), diag::note_odr_value_here)
3316         << FoundIvar->getType();
3317       return nullptr;
3318     }
3319   }
3320
3321   // Import the type.
3322   QualType T = Importer.Import(D->getType());
3323   if (T.isNull())
3324     return nullptr;
3325
3326   TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
3327   Expr *BitWidth = Importer.Import(D->getBitWidth());
3328   if (!BitWidth && D->getBitWidth())
3329     return nullptr;
3330
3331   ObjCIvarDecl *ToIvar = ObjCIvarDecl::Create(Importer.getToContext(),
3332                                               cast<ObjCContainerDecl>(DC),
3333                                        Importer.Import(D->getInnerLocStart()),
3334                                               Loc, Name.getAsIdentifierInfo(),
3335                                               T, TInfo, D->getAccessControl(),
3336                                               BitWidth, D->getSynthesize());
3337   ToIvar->setLexicalDeclContext(LexicalDC);
3338   Importer.Imported(D, ToIvar);
3339   LexicalDC->addDeclInternal(ToIvar);
3340   return ToIvar;
3341
3342 }
3343
3344 Decl *ASTNodeImporter::VisitVarDecl(VarDecl *D) {
3345   // Import the major distinguishing characteristics of a variable.
3346   DeclContext *DC, *LexicalDC;
3347   DeclarationName Name;
3348   SourceLocation Loc;
3349   NamedDecl *ToD;
3350   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
3351     return nullptr;
3352   if (ToD)
3353     return ToD;
3354
3355   // Try to find a variable in our own ("to") context with the same name and
3356   // in the same context as the variable we're importing.
3357   if (D->isFileVarDecl()) {
3358     VarDecl *MergeWithVar = nullptr;
3359     SmallVector<NamedDecl *, 4> ConflictingDecls;
3360     unsigned IDNS = Decl::IDNS_Ordinary;
3361     SmallVector<NamedDecl *, 2> FoundDecls;
3362     DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
3363     for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
3364       if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
3365         continue;
3366
3367       if (VarDecl *FoundVar = dyn_cast<VarDecl>(FoundDecls[I])) {
3368         // We have found a variable that we may need to merge with. Check it.
3369         if (FoundVar->hasExternalFormalLinkage() &&
3370             D->hasExternalFormalLinkage()) {
3371           if (Importer.IsStructurallyEquivalent(D->getType(),
3372                                                 FoundVar->getType())) {
3373             MergeWithVar = FoundVar;
3374             break;
3375           }
3376
3377           const ArrayType *FoundArray
3378             = Importer.getToContext().getAsArrayType(FoundVar->getType());
3379           const ArrayType *TArray
3380             = Importer.getToContext().getAsArrayType(D->getType());
3381           if (FoundArray && TArray) {
3382             if (isa<IncompleteArrayType>(FoundArray) &&
3383                 isa<ConstantArrayType>(TArray)) {
3384               // Import the type.
3385               QualType T = Importer.Import(D->getType());
3386               if (T.isNull())
3387                 return nullptr;
3388
3389               FoundVar->setType(T);
3390               MergeWithVar = FoundVar;
3391               break;
3392             } else if (isa<IncompleteArrayType>(TArray) &&
3393                        isa<ConstantArrayType>(FoundArray)) {
3394               MergeWithVar = FoundVar;
3395               break;
3396             }
3397           }
3398
3399           Importer.ToDiag(Loc, diag::err_odr_variable_type_inconsistent)
3400             << Name << D->getType() << FoundVar->getType();
3401           Importer.ToDiag(FoundVar->getLocation(), diag::note_odr_value_here)
3402             << FoundVar->getType();
3403         }
3404       }
3405
3406       ConflictingDecls.push_back(FoundDecls[I]);
3407     }
3408
3409     if (MergeWithVar) {
3410       // An equivalent variable with external linkage has been found. Link
3411       // the two declarations, then merge them.
3412       Importer.Imported(D, MergeWithVar);
3413
3414       if (VarDecl *DDef = D->getDefinition()) {
3415         if (VarDecl *ExistingDef = MergeWithVar->getDefinition()) {
3416           Importer.ToDiag(ExistingDef->getLocation(),
3417                           diag::err_odr_variable_multiple_def)
3418             << Name;
3419           Importer.FromDiag(DDef->getLocation(), diag::note_odr_defined_here);
3420         } else {
3421           Expr *Init = Importer.Import(DDef->getInit());
3422           MergeWithVar->setInit(Init);
3423           if (DDef->isInitKnownICE()) {
3424             EvaluatedStmt *Eval = MergeWithVar->ensureEvaluatedStmt();
3425             Eval->CheckedICE = true;
3426             Eval->IsICE = DDef->isInitICE();
3427           }
3428         }
3429       }
3430
3431       return MergeWithVar;
3432     }
3433
3434     if (!ConflictingDecls.empty()) {
3435       Name = Importer.HandleNameConflict(Name, DC, IDNS,
3436                                          ConflictingDecls.data(),
3437                                          ConflictingDecls.size());
3438       if (!Name)
3439         return nullptr;
3440     }
3441   }
3442
3443   // Import the type.
3444   QualType T = Importer.Import(D->getType());
3445   if (T.isNull())
3446     return nullptr;
3447
3448   // Create the imported variable.
3449   TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
3450   VarDecl *ToVar = VarDecl::Create(Importer.getToContext(), DC,
3451                                    Importer.Import(D->getInnerLocStart()),
3452                                    Loc, Name.getAsIdentifierInfo(),
3453                                    T, TInfo,
3454                                    D->getStorageClass());
3455   ToVar->setQualifierInfo(Importer.Import(D->getQualifierLoc()));
3456   ToVar->setAccess(D->getAccess());
3457   ToVar->setLexicalDeclContext(LexicalDC);
3458   Importer.Imported(D, ToVar);
3459   LexicalDC->addDeclInternal(ToVar);
3460
3461   if (!D->isFileVarDecl() &&
3462       D->isUsed())
3463     ToVar->setIsUsed();
3464
3465   // Merge the initializer.
3466   if (ImportDefinition(D, ToVar))
3467     return nullptr;
3468
3469   return ToVar;
3470 }
3471
3472 Decl *ASTNodeImporter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
3473   // Parameters are created in the translation unit's context, then moved
3474   // into the function declaration's context afterward.
3475   DeclContext *DC = Importer.getToContext().getTranslationUnitDecl();
3476
3477   // Import the name of this declaration.
3478   DeclarationName Name = Importer.Import(D->getDeclName());
3479   if (D->getDeclName() && !Name)
3480     return nullptr;
3481
3482   // Import the location of this declaration.
3483   SourceLocation Loc = Importer.Import(D->getLocation());
3484
3485   // Import the parameter's type.
3486   QualType T = Importer.Import(D->getType());
3487   if (T.isNull())
3488     return nullptr;
3489
3490   // Create the imported parameter.
3491   ImplicitParamDecl *ToParm
3492     = ImplicitParamDecl::Create(Importer.getToContext(), DC,
3493                                 Loc, Name.getAsIdentifierInfo(),
3494                                 T);
3495   return Importer.Imported(D, ToParm);
3496 }
3497
3498 Decl *ASTNodeImporter::VisitParmVarDecl(ParmVarDecl *D) {
3499   // Parameters are created in the translation unit's context, then moved
3500   // into the function declaration's context afterward.
3501   DeclContext *DC = Importer.getToContext().getTranslationUnitDecl();
3502
3503   // Import the name of this declaration.
3504   DeclarationName Name = Importer.Import(D->getDeclName());
3505   if (D->getDeclName() && !Name)
3506     return nullptr;
3507
3508   // Import the location of this declaration.
3509   SourceLocation Loc = Importer.Import(D->getLocation());
3510
3511   // Import the parameter's type.
3512   QualType T = Importer.Import(D->getType());
3513   if (T.isNull())
3514     return nullptr;
3515
3516   // Create the imported parameter.
3517   TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
3518   ParmVarDecl *ToParm = ParmVarDecl::Create(Importer.getToContext(), DC,
3519                                      Importer.Import(D->getInnerLocStart()),
3520                                             Loc, Name.getAsIdentifierInfo(),
3521                                             T, TInfo, D->getStorageClass(),
3522                                             /*FIXME: Default argument*/nullptr);
3523   ToParm->setHasInheritedDefaultArg(D->hasInheritedDefaultArg());
3524
3525   if (D->isUsed())
3526     ToParm->setIsUsed();
3527
3528   return Importer.Imported(D, ToParm);
3529 }
3530
3531 Decl *ASTNodeImporter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
3532   // Import the major distinguishing characteristics of a method.
3533   DeclContext *DC, *LexicalDC;
3534   DeclarationName Name;
3535   SourceLocation Loc;
3536   NamedDecl *ToD;
3537   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
3538     return nullptr;
3539   if (ToD)
3540     return ToD;
3541
3542   SmallVector<NamedDecl *, 2> FoundDecls;
3543   DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
3544   for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
3545     if (ObjCMethodDecl *FoundMethod = dyn_cast<ObjCMethodDecl>(FoundDecls[I])) {
3546       if (FoundMethod->isInstanceMethod() != D->isInstanceMethod())
3547         continue;
3548
3549       // Check return types.
3550       if (!Importer.IsStructurallyEquivalent(D->getReturnType(),
3551                                              FoundMethod->getReturnType())) {
3552         Importer.ToDiag(Loc, diag::err_odr_objc_method_result_type_inconsistent)
3553             << D->isInstanceMethod() << Name << D->getReturnType()
3554             << FoundMethod->getReturnType();
3555         Importer.ToDiag(FoundMethod->getLocation(),
3556                         diag::note_odr_objc_method_here)
3557           << D->isInstanceMethod() << Name;
3558         return nullptr;
3559       }
3560
3561       // Check the number of parameters.
3562       if (D->param_size() != FoundMethod->param_size()) {
3563         Importer.ToDiag(Loc, diag::err_odr_objc_method_num_params_inconsistent)
3564           << D->isInstanceMethod() << Name
3565           << D->param_size() << FoundMethod->param_size();
3566         Importer.ToDiag(FoundMethod->getLocation(),
3567                         diag::note_odr_objc_method_here)
3568           << D->isInstanceMethod() << Name;
3569         return nullptr;
3570       }
3571
3572       // Check parameter types.
3573       for (ObjCMethodDecl::param_iterator P = D->param_begin(),
3574              PEnd = D->param_end(), FoundP = FoundMethod->param_begin();
3575            P != PEnd; ++P, ++FoundP) {
3576         if (!Importer.IsStructurallyEquivalent((*P)->getType(),
3577                                                (*FoundP)->getType())) {
3578           Importer.FromDiag((*P)->getLocation(),
3579                             diag::err_odr_objc_method_param_type_inconsistent)
3580             << D->isInstanceMethod() << Name
3581             << (*P)->getType() << (*FoundP)->getType();
3582           Importer.ToDiag((*FoundP)->getLocation(), diag::note_odr_value_here)
3583             << (*FoundP)->getType();
3584           return nullptr;
3585         }
3586       }
3587
3588       // Check variadic/non-variadic.
3589       // Check the number of parameters.
3590       if (D->isVariadic() != FoundMethod->isVariadic()) {
3591         Importer.ToDiag(Loc, diag::err_odr_objc_method_variadic_inconsistent)
3592           << D->isInstanceMethod() << Name;
3593         Importer.ToDiag(FoundMethod->getLocation(),
3594                         diag::note_odr_objc_method_here)
3595           << D->isInstanceMethod() << Name;
3596         return nullptr;
3597       }
3598
3599       // FIXME: Any other bits we need to merge?
3600       return Importer.Imported(D, FoundMethod);
3601     }
3602   }
3603
3604   // Import the result type.
3605   QualType ResultTy = Importer.Import(D->getReturnType());
3606   if (ResultTy.isNull())
3607     return nullptr;
3608
3609   TypeSourceInfo *ReturnTInfo = Importer.Import(D->getReturnTypeSourceInfo());
3610
3611   ObjCMethodDecl *ToMethod = ObjCMethodDecl::Create(
3612       Importer.getToContext(), Loc, Importer.Import(D->getLocEnd()),
3613       Name.getObjCSelector(), ResultTy, ReturnTInfo, DC, D->isInstanceMethod(),
3614       D->isVariadic(), D->isPropertyAccessor(), D->isImplicit(), D->isDefined(),
3615       D->getImplementationControl(), D->hasRelatedResultType());
3616
3617   // FIXME: When we decide to merge method definitions, we'll need to
3618   // deal with implicit parameters.
3619
3620   // Import the parameters
3621   SmallVector<ParmVarDecl *, 5> ToParams;
3622   for (auto *FromP : D->parameters()) {
3623     ParmVarDecl *ToP = cast_or_null<ParmVarDecl>(Importer.Import(FromP));
3624     if (!ToP)
3625       return nullptr;
3626
3627     ToParams.push_back(ToP);
3628   }
3629
3630   // Set the parameters.
3631   for (unsigned I = 0, N = ToParams.size(); I != N; ++I) {
3632     ToParams[I]->setOwningFunction(ToMethod);
3633     ToMethod->addDeclInternal(ToParams[I]);
3634   }
3635   SmallVector<SourceLocation, 12> SelLocs;
3636   D->getSelectorLocs(SelLocs);
3637   ToMethod->setMethodParams(Importer.getToContext(), ToParams, SelLocs);
3638
3639   ToMethod->setLexicalDeclContext(LexicalDC);
3640   Importer.Imported(D, ToMethod);
3641   LexicalDC->addDeclInternal(ToMethod);
3642   return ToMethod;
3643 }
3644
3645 Decl *ASTNodeImporter::VisitObjCTypeParamDecl(ObjCTypeParamDecl *D) {
3646   // Import the major distinguishing characteristics of a category.
3647   DeclContext *DC, *LexicalDC;
3648   DeclarationName Name;
3649   SourceLocation Loc;
3650   NamedDecl *ToD;
3651   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
3652     return nullptr;
3653   if (ToD)
3654     return ToD;
3655
3656   TypeSourceInfo *BoundInfo = Importer.Import(D->getTypeSourceInfo());
3657   if (!BoundInfo)
3658     return nullptr;
3659
3660   ObjCTypeParamDecl *Result = ObjCTypeParamDecl::Create(
3661                                 Importer.getToContext(), DC,
3662                                 D->getVariance(),
3663                                 Importer.Import(D->getVarianceLoc()),
3664                                 D->getIndex(),
3665                                 Importer.Import(D->getLocation()),
3666                                 Name.getAsIdentifierInfo(),
3667                                 Importer.Import(D->getColonLoc()),
3668                                 BoundInfo);
3669   Importer.Imported(D, Result);
3670   Result->setLexicalDeclContext(LexicalDC);
3671   return Result;
3672 }
3673
3674 Decl *ASTNodeImporter::VisitObjCCategoryDecl(ObjCCategoryDecl *D) {
3675   // Import the major distinguishing characteristics of a category.
3676   DeclContext *DC, *LexicalDC;
3677   DeclarationName Name;
3678   SourceLocation Loc;
3679   NamedDecl *ToD;
3680   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
3681     return nullptr;
3682   if (ToD)
3683     return ToD;
3684
3685   ObjCInterfaceDecl *ToInterface
3686     = cast_or_null<ObjCInterfaceDecl>(Importer.Import(D->getClassInterface()));
3687   if (!ToInterface)
3688     return nullptr;
3689
3690   // Determine if we've already encountered this category.
3691   ObjCCategoryDecl *MergeWithCategory
3692     = ToInterface->FindCategoryDeclaration(Name.getAsIdentifierInfo());
3693   ObjCCategoryDecl *ToCategory = MergeWithCategory;
3694   if (!ToCategory) {
3695     ToCategory = ObjCCategoryDecl::Create(Importer.getToContext(), DC,
3696                                           Importer.Import(D->getAtStartLoc()),
3697                                           Loc,
3698                                        Importer.Import(D->getCategoryNameLoc()),
3699                                           Name.getAsIdentifierInfo(),
3700                                           ToInterface,
3701                                           /*TypeParamList=*/nullptr,
3702                                        Importer.Import(D->getIvarLBraceLoc()),
3703                                        Importer.Import(D->getIvarRBraceLoc()));
3704     ToCategory->setLexicalDeclContext(LexicalDC);
3705     LexicalDC->addDeclInternal(ToCategory);
3706     Importer.Imported(D, ToCategory);
3707     // Import the type parameter list after calling Imported, to avoid
3708     // loops when bringing in their DeclContext.
3709     ToCategory->setTypeParamList(ImportObjCTypeParamList(
3710                                    D->getTypeParamList()));
3711
3712     // Import protocols
3713     SmallVector<ObjCProtocolDecl *, 4> Protocols;
3714     SmallVector<SourceLocation, 4> ProtocolLocs;
3715     ObjCCategoryDecl::protocol_loc_iterator FromProtoLoc
3716       = D->protocol_loc_begin();
3717     for (ObjCCategoryDecl::protocol_iterator FromProto = D->protocol_begin(),
3718                                           FromProtoEnd = D->protocol_end();
3719          FromProto != FromProtoEnd;
3720          ++FromProto, ++FromProtoLoc) {
3721       ObjCProtocolDecl *ToProto
3722         = cast_or_null<ObjCProtocolDecl>(Importer.Import(*FromProto));
3723       if (!ToProto)
3724         return nullptr;
3725       Protocols.push_back(ToProto);
3726       ProtocolLocs.push_back(Importer.Import(*FromProtoLoc));
3727     }
3728
3729     // FIXME: If we're merging, make sure that the protocol list is the same.
3730     ToCategory->setProtocolList(Protocols.data(), Protocols.size(),
3731                                 ProtocolLocs.data(), Importer.getToContext());
3732
3733   } else {
3734     Importer.Imported(D, ToCategory);
3735   }
3736
3737   // Import all of the members of this category.
3738   ImportDeclContext(D);
3739
3740   // If we have an implementation, import it as well.
3741   if (D->getImplementation()) {
3742     ObjCCategoryImplDecl *Impl
3743       = cast_or_null<ObjCCategoryImplDecl>(
3744                                        Importer.Import(D->getImplementation()));
3745     if (!Impl)
3746       return nullptr;
3747
3748     ToCategory->setImplementation(Impl);
3749   }
3750
3751   return ToCategory;
3752 }
3753
3754 bool ASTNodeImporter::ImportDefinition(ObjCProtocolDecl *From,
3755                                        ObjCProtocolDecl *To,
3756                                        ImportDefinitionKind Kind) {
3757   if (To->getDefinition()) {
3758     if (shouldForceImportDeclContext(Kind))
3759       ImportDeclContext(From);
3760     return false;
3761   }
3762
3763   // Start the protocol definition
3764   To->startDefinition();
3765
3766   // Import protocols
3767   SmallVector<ObjCProtocolDecl *, 4> Protocols;
3768   SmallVector<SourceLocation, 4> ProtocolLocs;
3769   ObjCProtocolDecl::protocol_loc_iterator
3770   FromProtoLoc = From->protocol_loc_begin();
3771   for (ObjCProtocolDecl::protocol_iterator FromProto = From->protocol_begin(),
3772                                         FromProtoEnd = From->protocol_end();
3773        FromProto != FromProtoEnd;
3774        ++FromProto, ++FromProtoLoc) {
3775     ObjCProtocolDecl *ToProto
3776       = cast_or_null<ObjCProtocolDecl>(Importer.Import(*FromProto));
3777     if (!ToProto)
3778       return true;
3779     Protocols.push_back(ToProto);
3780     ProtocolLocs.push_back(Importer.Import(*FromProtoLoc));
3781   }
3782
3783   // FIXME: If we're merging, make sure that the protocol list is the same.
3784   To->setProtocolList(Protocols.data(), Protocols.size(),
3785                       ProtocolLocs.data(), Importer.getToContext());
3786
3787   if (shouldForceImportDeclContext(Kind)) {
3788     // Import all of the members of this protocol.
3789     ImportDeclContext(From, /*ForceImport=*/true);
3790   }
3791   return false;
3792 }
3793
3794 Decl *ASTNodeImporter::VisitObjCProtocolDecl(ObjCProtocolDecl *D) {
3795   // If this protocol has a definition in the translation unit we're coming
3796   // from, but this particular declaration is not that definition, import the
3797   // definition and map to that.
3798   ObjCProtocolDecl *Definition = D->getDefinition();
3799   if (Definition && Definition != D) {
3800     Decl *ImportedDef = Importer.Import(Definition);
3801     if (!ImportedDef)
3802       return nullptr;
3803
3804     return Importer.Imported(D, ImportedDef);
3805   }
3806
3807   // Import the major distinguishing characteristics of a protocol.
3808   DeclContext *DC, *LexicalDC;
3809   DeclarationName Name;
3810   SourceLocation Loc;
3811   NamedDecl *ToD;
3812   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
3813     return nullptr;
3814   if (ToD)
3815     return ToD;
3816
3817   ObjCProtocolDecl *MergeWithProtocol = nullptr;
3818   SmallVector<NamedDecl *, 2> FoundDecls;
3819   DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
3820   for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
3821     if (!FoundDecls[I]->isInIdentifierNamespace(Decl::IDNS_ObjCProtocol))
3822       continue;
3823
3824     if ((MergeWithProtocol = dyn_cast<ObjCProtocolDecl>(FoundDecls[I])))
3825       break;
3826   }
3827
3828   ObjCProtocolDecl *ToProto = MergeWithProtocol;
3829   if (!ToProto) {
3830     ToProto = ObjCProtocolDecl::Create(Importer.getToContext(), DC,
3831                                        Name.getAsIdentifierInfo(), Loc,
3832                                        Importer.Import(D->getAtStartLoc()),
3833                                        /*PrevDecl=*/nullptr);
3834     ToProto->setLexicalDeclContext(LexicalDC);
3835     LexicalDC->addDeclInternal(ToProto);
3836   }
3837
3838   Importer.Imported(D, ToProto);
3839
3840   if (D->isThisDeclarationADefinition() && ImportDefinition(D, ToProto))
3841     return nullptr;
3842
3843   return ToProto;
3844 }
3845
3846 Decl *ASTNodeImporter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
3847   DeclContext *DC = Importer.ImportContext(D->getDeclContext());
3848   DeclContext *LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
3849
3850   SourceLocation ExternLoc = Importer.Import(D->getExternLoc());
3851   SourceLocation LangLoc = Importer.Import(D->getLocation());
3852
3853   bool HasBraces = D->hasBraces();
3854
3855   LinkageSpecDecl *ToLinkageSpec =
3856     LinkageSpecDecl::Create(Importer.getToContext(),
3857                             DC,
3858                             ExternLoc,
3859                             LangLoc,
3860                             D->getLanguage(),
3861                             HasBraces);
3862
3863   if (HasBraces) {
3864     SourceLocation RBraceLoc = Importer.Import(D->getRBraceLoc());
3865     ToLinkageSpec->setRBraceLoc(RBraceLoc);
3866   }
3867
3868   ToLinkageSpec->setLexicalDeclContext(LexicalDC);
3869   LexicalDC->addDeclInternal(ToLinkageSpec);
3870
3871   Importer.Imported(D, ToLinkageSpec);
3872
3873   return ToLinkageSpec;
3874 }
3875
3876 bool ASTNodeImporter::ImportDefinition(ObjCInterfaceDecl *From,
3877                                        ObjCInterfaceDecl *To,
3878                                        ImportDefinitionKind Kind) {
3879   if (To->getDefinition()) {
3880     // Check consistency of superclass.
3881     ObjCInterfaceDecl *FromSuper = From->getSuperClass();
3882     if (FromSuper) {
3883       FromSuper = cast_or_null<ObjCInterfaceDecl>(Importer.Import(FromSuper));
3884       if (!FromSuper)
3885         return true;
3886     }
3887
3888     ObjCInterfaceDecl *ToSuper = To->getSuperClass();
3889     if ((bool)FromSuper != (bool)ToSuper ||
3890         (FromSuper && !declaresSameEntity(FromSuper, ToSuper))) {
3891       Importer.ToDiag(To->getLocation(),
3892                       diag::err_odr_objc_superclass_inconsistent)
3893         << To->getDeclName();
3894       if (ToSuper)
3895         Importer.ToDiag(To->getSuperClassLoc(), diag::note_odr_objc_superclass)
3896           << To->getSuperClass()->getDeclName();
3897       else
3898         Importer.ToDiag(To->getLocation(),
3899                         diag::note_odr_objc_missing_superclass);
3900       if (From->getSuperClass())
3901         Importer.FromDiag(From->getSuperClassLoc(),
3902                           diag::note_odr_objc_superclass)
3903         << From->getSuperClass()->getDeclName();
3904       else
3905         Importer.FromDiag(From->getLocation(),
3906                           diag::note_odr_objc_missing_superclass);
3907     }
3908
3909     if (shouldForceImportDeclContext(Kind))
3910       ImportDeclContext(From);
3911     return false;
3912   }
3913
3914   // Start the definition.
3915   To->startDefinition();
3916
3917   // If this class has a superclass, import it.
3918   if (From->getSuperClass()) {
3919     TypeSourceInfo *SuperTInfo = Importer.Import(From->getSuperClassTInfo());
3920     if (!SuperTInfo)
3921       return true;
3922
3923     To->setSuperClass(SuperTInfo);
3924   }
3925
3926   // Import protocols
3927   SmallVector<ObjCProtocolDecl *, 4> Protocols;
3928   SmallVector<SourceLocation, 4> ProtocolLocs;
3929   ObjCInterfaceDecl::protocol_loc_iterator
3930   FromProtoLoc = From->protocol_loc_begin();
3931
3932   for (ObjCInterfaceDecl::protocol_iterator FromProto = From->protocol_begin(),
3933                                          FromProtoEnd = From->protocol_end();
3934        FromProto != FromProtoEnd;
3935        ++FromProto, ++FromProtoLoc) {
3936     ObjCProtocolDecl *ToProto
3937       = cast_or_null<ObjCProtocolDecl>(Importer.Import(*FromProto));
3938     if (!ToProto)
3939       return true;
3940     Protocols.push_back(ToProto);
3941     ProtocolLocs.push_back(Importer.Import(*FromProtoLoc));
3942   }
3943
3944   // FIXME: If we're merging, make sure that the protocol list is the same.
3945   To->setProtocolList(Protocols.data(), Protocols.size(),
3946                       ProtocolLocs.data(), Importer.getToContext());
3947
3948   // Import categories. When the categories themselves are imported, they'll
3949   // hook themselves into this interface.
3950   for (auto *Cat : From->known_categories())
3951     Importer.Import(Cat);
3952
3953   // If we have an @implementation, import it as well.
3954   if (From->getImplementation()) {
3955     ObjCImplementationDecl *Impl = cast_or_null<ObjCImplementationDecl>(
3956                                      Importer.Import(From->getImplementation()));
3957     if (!Impl)
3958       return true;
3959
3960     To->setImplementation(Impl);
3961   }
3962
3963   if (shouldForceImportDeclContext(Kind)) {
3964     // Import all of the members of this class.
3965     ImportDeclContext(From, /*ForceImport=*/true);
3966   }
3967   return false;
3968 }
3969
3970 ObjCTypeParamList *
3971 ASTNodeImporter::ImportObjCTypeParamList(ObjCTypeParamList *list) {
3972   if (!list)
3973     return nullptr;
3974
3975   SmallVector<ObjCTypeParamDecl *, 4> toTypeParams;
3976   for (auto fromTypeParam : *list) {
3977     auto toTypeParam = cast_or_null<ObjCTypeParamDecl>(
3978                          Importer.Import(fromTypeParam));
3979     if (!toTypeParam)
3980       return nullptr;
3981
3982     toTypeParams.push_back(toTypeParam);
3983   }
3984
3985   return ObjCTypeParamList::create(Importer.getToContext(),
3986                                    Importer.Import(list->getLAngleLoc()),
3987                                    toTypeParams,
3988                                    Importer.Import(list->getRAngleLoc()));
3989 }
3990
3991 Decl *ASTNodeImporter::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
3992   // If this class has a definition in the translation unit we're coming from,
3993   // but this particular declaration is not that definition, import the
3994   // definition and map to that.
3995   ObjCInterfaceDecl *Definition = D->getDefinition();
3996   if (Definition && Definition != D) {
3997     Decl *ImportedDef = Importer.Import(Definition);
3998     if (!ImportedDef)
3999       return nullptr;
4000
4001     return Importer.Imported(D, ImportedDef);
4002   }
4003
4004   // Import the major distinguishing characteristics of an @interface.
4005   DeclContext *DC, *LexicalDC;
4006   DeclarationName Name;
4007   SourceLocation Loc;
4008   NamedDecl *ToD;
4009   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
4010     return nullptr;
4011   if (ToD)
4012     return ToD;
4013
4014   // Look for an existing interface with the same name.
4015   ObjCInterfaceDecl *MergeWithIface = nullptr;
4016   SmallVector<NamedDecl *, 2> FoundDecls;
4017   DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
4018   for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
4019     if (!FoundDecls[I]->isInIdentifierNamespace(Decl::IDNS_Ordinary))
4020       continue;
4021
4022     if ((MergeWithIface = dyn_cast<ObjCInterfaceDecl>(FoundDecls[I])))
4023       break;
4024   }
4025
4026   // Create an interface declaration, if one does not already exist.
4027   ObjCInterfaceDecl *ToIface = MergeWithIface;
4028   if (!ToIface) {
4029     ToIface = ObjCInterfaceDecl::Create(Importer.getToContext(), DC,
4030                                         Importer.Import(D->getAtStartLoc()),
4031                                         Name.getAsIdentifierInfo(),
4032                                         /*TypeParamList=*/nullptr,
4033                                         /*PrevDecl=*/nullptr, Loc,
4034                                         D->isImplicitInterfaceDecl());
4035     ToIface->setLexicalDeclContext(LexicalDC);
4036     LexicalDC->addDeclInternal(ToIface);
4037   }
4038   Importer.Imported(D, ToIface);
4039   // Import the type parameter list after calling Imported, to avoid
4040   // loops when bringing in their DeclContext.
4041   ToIface->setTypeParamList(ImportObjCTypeParamList(
4042                               D->getTypeParamListAsWritten()));
4043
4044   if (D->isThisDeclarationADefinition() && ImportDefinition(D, ToIface))
4045     return nullptr;
4046
4047   return ToIface;
4048 }
4049
4050 Decl *ASTNodeImporter::VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D) {
4051   ObjCCategoryDecl *Category = cast_or_null<ObjCCategoryDecl>(
4052                                         Importer.Import(D->getCategoryDecl()));
4053   if (!Category)
4054     return nullptr;
4055
4056   ObjCCategoryImplDecl *ToImpl = Category->getImplementation();
4057   if (!ToImpl) {
4058     DeclContext *DC = Importer.ImportContext(D->getDeclContext());
4059     if (!DC)
4060       return nullptr;
4061
4062     SourceLocation CategoryNameLoc = Importer.Import(D->getCategoryNameLoc());
4063     ToImpl = ObjCCategoryImplDecl::Create(Importer.getToContext(), DC,
4064                                           Importer.Import(D->getIdentifier()),
4065                                           Category->getClassInterface(),
4066                                           Importer.Import(D->getLocation()),
4067                                           Importer.Import(D->getAtStartLoc()),
4068                                           CategoryNameLoc);
4069
4070     DeclContext *LexicalDC = DC;
4071     if (D->getDeclContext() != D->getLexicalDeclContext()) {
4072       LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
4073       if (!LexicalDC)
4074         return nullptr;
4075
4076       ToImpl->setLexicalDeclContext(LexicalDC);
4077     }
4078
4079     LexicalDC->addDeclInternal(ToImpl);
4080     Category->setImplementation(ToImpl);
4081   }
4082
4083   Importer.Imported(D, ToImpl);
4084   ImportDeclContext(D);
4085   return ToImpl;
4086 }
4087
4088 Decl *ASTNodeImporter::VisitObjCImplementationDecl(ObjCImplementationDecl *D) {
4089   // Find the corresponding interface.
4090   ObjCInterfaceDecl *Iface = cast_or_null<ObjCInterfaceDecl>(
4091                                        Importer.Import(D->getClassInterface()));
4092   if (!Iface)
4093     return nullptr;
4094
4095   // Import the superclass, if any.
4096   ObjCInterfaceDecl *Super = nullptr;
4097   if (D->getSuperClass()) {
4098     Super = cast_or_null<ObjCInterfaceDecl>(
4099                                           Importer.Import(D->getSuperClass()));
4100     if (!Super)
4101       return nullptr;
4102   }
4103
4104   ObjCImplementationDecl *Impl = Iface->getImplementation();
4105   if (!Impl) {
4106     // We haven't imported an implementation yet. Create a new @implementation
4107     // now.
4108     Impl = ObjCImplementationDecl::Create(Importer.getToContext(),
4109                                   Importer.ImportContext(D->getDeclContext()),
4110                                           Iface, Super,
4111                                           Importer.Import(D->getLocation()),
4112                                           Importer.Import(D->getAtStartLoc()),
4113                                           Importer.Import(D->getSuperClassLoc()),
4114                                           Importer.Import(D->getIvarLBraceLoc()),
4115                                           Importer.Import(D->getIvarRBraceLoc()));
4116
4117     if (D->getDeclContext() != D->getLexicalDeclContext()) {
4118       DeclContext *LexicalDC
4119         = Importer.ImportContext(D->getLexicalDeclContext());
4120       if (!LexicalDC)
4121         return nullptr;
4122       Impl->setLexicalDeclContext(LexicalDC);
4123     }
4124
4125     // Associate the implementation with the class it implements.
4126     Iface->setImplementation(Impl);
4127     Importer.Imported(D, Iface->getImplementation());
4128   } else {
4129     Importer.Imported(D, Iface->getImplementation());
4130
4131     // Verify that the existing @implementation has the same superclass.
4132     if ((Super && !Impl->getSuperClass()) ||
4133         (!Super && Impl->getSuperClass()) ||
4134         (Super && Impl->getSuperClass() &&
4135          !declaresSameEntity(Super->getCanonicalDecl(),
4136                              Impl->getSuperClass()))) {
4137       Importer.ToDiag(Impl->getLocation(),
4138                       diag::err_odr_objc_superclass_inconsistent)
4139         << Iface->getDeclName();
4140       // FIXME: It would be nice to have the location of the superclass
4141       // below.
4142       if (Impl->getSuperClass())
4143         Importer.ToDiag(Impl->getLocation(),
4144                         diag::note_odr_objc_superclass)
4145         << Impl->getSuperClass()->getDeclName();
4146       else
4147         Importer.ToDiag(Impl->getLocation(),
4148                         diag::note_odr_objc_missing_superclass);
4149       if (D->getSuperClass())
4150         Importer.FromDiag(D->getLocation(),
4151                           diag::note_odr_objc_superclass)
4152         << D->getSuperClass()->getDeclName();
4153       else
4154         Importer.FromDiag(D->getLocation(),
4155                           diag::note_odr_objc_missing_superclass);
4156       return nullptr;
4157     }
4158   }
4159
4160   // Import all of the members of this @implementation.
4161   ImportDeclContext(D);
4162
4163   return Impl;
4164 }
4165
4166 Decl *ASTNodeImporter::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
4167   // Import the major distinguishing characteristics of an @property.
4168   DeclContext *DC, *LexicalDC;
4169   DeclarationName Name;
4170   SourceLocation Loc;
4171   NamedDecl *ToD;
4172   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
4173     return nullptr;
4174   if (ToD)
4175     return ToD;
4176
4177   // Check whether we have already imported this property.
4178   SmallVector<NamedDecl *, 2> FoundDecls;
4179   DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
4180   for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
4181     if (ObjCPropertyDecl *FoundProp
4182                                 = dyn_cast<ObjCPropertyDecl>(FoundDecls[I])) {
4183       // Check property types.
4184       if (!Importer.IsStructurallyEquivalent(D->getType(),
4185                                              FoundProp->getType())) {
4186         Importer.ToDiag(Loc, diag::err_odr_objc_property_type_inconsistent)
4187           << Name << D->getType() << FoundProp->getType();
4188         Importer.ToDiag(FoundProp->getLocation(), diag::note_odr_value_here)
4189           << FoundProp->getType();
4190         return nullptr;
4191       }
4192
4193       // FIXME: Check property attributes, getters, setters, etc.?
4194
4195       // Consider these properties to be equivalent.
4196       Importer.Imported(D, FoundProp);
4197       return FoundProp;
4198     }
4199   }
4200
4201   // Import the type.
4202   TypeSourceInfo *TSI = Importer.Import(D->getTypeSourceInfo());
4203   if (!TSI)
4204     return nullptr;
4205
4206   // Create the new property.
4207   ObjCPropertyDecl *ToProperty
4208     = ObjCPropertyDecl::Create(Importer.getToContext(), DC, Loc,
4209                                Name.getAsIdentifierInfo(),
4210                                Importer.Import(D->getAtLoc()),
4211                                Importer.Import(D->getLParenLoc()),
4212                                Importer.Import(D->getType()),
4213                                TSI,
4214                                D->getPropertyImplementation());
4215   Importer.Imported(D, ToProperty);
4216   ToProperty->setLexicalDeclContext(LexicalDC);
4217   LexicalDC->addDeclInternal(ToProperty);
4218
4219   ToProperty->setPropertyAttributes(D->getPropertyAttributes());
4220   ToProperty->setPropertyAttributesAsWritten(
4221                                       D->getPropertyAttributesAsWritten());
4222   ToProperty->setGetterName(Importer.Import(D->getGetterName()));
4223   ToProperty->setSetterName(Importer.Import(D->getSetterName()));
4224   ToProperty->setGetterMethodDecl(
4225      cast_or_null<ObjCMethodDecl>(Importer.Import(D->getGetterMethodDecl())));
4226   ToProperty->setSetterMethodDecl(
4227      cast_or_null<ObjCMethodDecl>(Importer.Import(D->getSetterMethodDecl())));
4228   ToProperty->setPropertyIvarDecl(
4229        cast_or_null<ObjCIvarDecl>(Importer.Import(D->getPropertyIvarDecl())));
4230   return ToProperty;
4231 }
4232
4233 Decl *ASTNodeImporter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
4234   ObjCPropertyDecl *Property = cast_or_null<ObjCPropertyDecl>(
4235                                         Importer.Import(D->getPropertyDecl()));
4236   if (!Property)
4237     return nullptr;
4238
4239   DeclContext *DC = Importer.ImportContext(D->getDeclContext());
4240   if (!DC)
4241     return nullptr;
4242
4243   // Import the lexical declaration context.
4244   DeclContext *LexicalDC = DC;
4245   if (D->getDeclContext() != D->getLexicalDeclContext()) {
4246     LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
4247     if (!LexicalDC)
4248       return nullptr;
4249   }
4250
4251   ObjCImplDecl *InImpl = dyn_cast<ObjCImplDecl>(LexicalDC);
4252   if (!InImpl)
4253     return nullptr;
4254
4255   // Import the ivar (for an @synthesize).
4256   ObjCIvarDecl *Ivar = nullptr;
4257   if (D->getPropertyIvarDecl()) {
4258     Ivar = cast_or_null<ObjCIvarDecl>(
4259                                     Importer.Import(D->getPropertyIvarDecl()));
4260     if (!Ivar)
4261       return nullptr;
4262   }
4263
4264   ObjCPropertyImplDecl *ToImpl
4265     = InImpl->FindPropertyImplDecl(Property->getIdentifier(),
4266                                    Property->getQueryKind());
4267   if (!ToImpl) {
4268     ToImpl = ObjCPropertyImplDecl::Create(Importer.getToContext(), DC,
4269                                           Importer.Import(D->getLocStart()),
4270                                           Importer.Import(D->getLocation()),
4271                                           Property,
4272                                           D->getPropertyImplementation(),
4273                                           Ivar,
4274                                   Importer.Import(D->getPropertyIvarDeclLoc()));
4275     ToImpl->setLexicalDeclContext(LexicalDC);
4276     Importer.Imported(D, ToImpl);
4277     LexicalDC->addDeclInternal(ToImpl);
4278   } else {
4279     // Check that we have the same kind of property implementation (@synthesize
4280     // vs. @dynamic).
4281     if (D->getPropertyImplementation() != ToImpl->getPropertyImplementation()) {
4282       Importer.ToDiag(ToImpl->getLocation(),
4283                       diag::err_odr_objc_property_impl_kind_inconsistent)
4284         << Property->getDeclName()
4285         << (ToImpl->getPropertyImplementation()
4286                                               == ObjCPropertyImplDecl::Dynamic);
4287       Importer.FromDiag(D->getLocation(),
4288                         diag::note_odr_objc_property_impl_kind)
4289         << D->getPropertyDecl()->getDeclName()
4290         << (D->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic);
4291       return nullptr;
4292     }
4293
4294     // For @synthesize, check that we have the same
4295     if (D->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize &&
4296         Ivar != ToImpl->getPropertyIvarDecl()) {
4297       Importer.ToDiag(ToImpl->getPropertyIvarDeclLoc(),
4298                       diag::err_odr_objc_synthesize_ivar_inconsistent)
4299         << Property->getDeclName()
4300         << ToImpl->getPropertyIvarDecl()->getDeclName()
4301         << Ivar->getDeclName();
4302       Importer.FromDiag(D->getPropertyIvarDeclLoc(),
4303                         diag::note_odr_objc_synthesize_ivar_here)
4304         << D->getPropertyIvarDecl()->getDeclName();
4305       return nullptr;
4306     }
4307
4308     // Merge the existing implementation with the new implementation.
4309     Importer.Imported(D, ToImpl);
4310   }
4311
4312   return ToImpl;
4313 }
4314
4315 Decl *ASTNodeImporter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
4316   // For template arguments, we adopt the translation unit as our declaration
4317   // context. This context will be fixed when the actual template declaration
4318   // is created.
4319
4320   // FIXME: Import default argument.
4321   return TemplateTypeParmDecl::Create(Importer.getToContext(),
4322                               Importer.getToContext().getTranslationUnitDecl(),
4323                                       Importer.Import(D->getLocStart()),
4324                                       Importer.Import(D->getLocation()),
4325                                       D->getDepth(),
4326                                       D->getIndex(),
4327                                       Importer.Import(D->getIdentifier()),
4328                                       D->wasDeclaredWithTypename(),
4329                                       D->isParameterPack());
4330 }
4331
4332 Decl *
4333 ASTNodeImporter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
4334   // Import the name of this declaration.
4335   DeclarationName Name = Importer.Import(D->getDeclName());
4336   if (D->getDeclName() && !Name)
4337     return nullptr;
4338
4339   // Import the location of this declaration.
4340   SourceLocation Loc = Importer.Import(D->getLocation());
4341
4342   // Import the type of this declaration.
4343   QualType T = Importer.Import(D->getType());
4344   if (T.isNull())
4345     return nullptr;
4346
4347   // Import type-source information.
4348   TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
4349   if (D->getTypeSourceInfo() && !TInfo)
4350     return nullptr;
4351
4352   // FIXME: Import default argument.
4353
4354   return NonTypeTemplateParmDecl::Create(Importer.getToContext(),
4355                                Importer.getToContext().getTranslationUnitDecl(),
4356                                          Importer.Import(D->getInnerLocStart()),
4357                                          Loc, D->getDepth(), D->getPosition(),
4358                                          Name.getAsIdentifierInfo(),
4359                                          T, D->isParameterPack(), TInfo);
4360 }
4361
4362 Decl *
4363 ASTNodeImporter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
4364   // Import the name of this declaration.
4365   DeclarationName Name = Importer.Import(D->getDeclName());
4366   if (D->getDeclName() && !Name)
4367     return nullptr;
4368
4369   // Import the location of this declaration.
4370   SourceLocation Loc = Importer.Import(D->getLocation());
4371
4372   // Import template parameters.
4373   TemplateParameterList *TemplateParams
4374     = ImportTemplateParameterList(D->getTemplateParameters());
4375   if (!TemplateParams)
4376     return nullptr;
4377
4378   // FIXME: Import default argument.
4379
4380   return TemplateTemplateParmDecl::Create(Importer.getToContext(),
4381                               Importer.getToContext().getTranslationUnitDecl(),
4382                                           Loc, D->getDepth(), D->getPosition(),
4383                                           D->isParameterPack(),
4384                                           Name.getAsIdentifierInfo(),
4385                                           TemplateParams);
4386 }
4387
4388 Decl *ASTNodeImporter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
4389   // If this record has a definition in the translation unit we're coming from,
4390   // but this particular declaration is not that definition, import the
4391   // definition and map to that.
4392   CXXRecordDecl *Definition
4393     = cast_or_null<CXXRecordDecl>(D->getTemplatedDecl()->getDefinition());
4394   if (Definition && Definition != D->getTemplatedDecl()) {
4395     Decl *ImportedDef
4396       = Importer.Import(Definition->getDescribedClassTemplate());
4397     if (!ImportedDef)
4398       return nullptr;
4399
4400     return Importer.Imported(D, ImportedDef);
4401   }
4402
4403   // Import the major distinguishing characteristics of this class template.
4404   DeclContext *DC, *LexicalDC;
4405   DeclarationName Name;
4406   SourceLocation Loc;
4407   NamedDecl *ToD;
4408   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
4409     return nullptr;
4410   if (ToD)
4411     return ToD;
4412
4413   // We may already have a template of the same name; try to find and match it.
4414   if (!DC->isFunctionOrMethod()) {
4415     SmallVector<NamedDecl *, 4> ConflictingDecls;
4416     SmallVector<NamedDecl *, 2> FoundDecls;
4417     DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
4418     for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
4419       if (!FoundDecls[I]->isInIdentifierNamespace(Decl::IDNS_Ordinary))
4420         continue;
4421
4422       Decl *Found = FoundDecls[I];
4423       if (ClassTemplateDecl *FoundTemplate
4424                                         = dyn_cast<ClassTemplateDecl>(Found)) {
4425         if (IsStructuralMatch(D, FoundTemplate)) {
4426           // The class templates structurally match; call it the same template.
4427           // FIXME: We may be filling in a forward declaration here. Handle
4428           // this case!
4429           Importer.Imported(D->getTemplatedDecl(),
4430                             FoundTemplate->getTemplatedDecl());
4431           return Importer.Imported(D, FoundTemplate);
4432         }
4433       }
4434
4435       ConflictingDecls.push_back(FoundDecls[I]);
4436     }
4437
4438     if (!ConflictingDecls.empty()) {
4439       Name = Importer.HandleNameConflict(Name, DC, Decl::IDNS_Ordinary,
4440                                          ConflictingDecls.data(),
4441                                          ConflictingDecls.size());
4442     }
4443
4444     if (!Name)
4445       return nullptr;
4446   }
4447
4448   CXXRecordDecl *DTemplated = D->getTemplatedDecl();
4449
4450   // Create the declaration that is being templated.
4451   // Create the declaration that is being templated.
4452   CXXRecordDecl *D2Templated = cast_or_null<CXXRecordDecl>(
4453         Importer.Import(DTemplated));
4454   if (!D2Templated)
4455     return nullptr;
4456
4457   // Resolve possible cyclic import.
4458   if (Decl *AlreadyImported = Importer.GetAlreadyImportedOrNull(D))
4459     return AlreadyImported;
4460
4461   // Create the class template declaration itself.
4462   TemplateParameterList *TemplateParams
4463     = ImportTemplateParameterList(D->getTemplateParameters());
4464   if (!TemplateParams)
4465     return nullptr;
4466
4467   ClassTemplateDecl *D2 = ClassTemplateDecl::Create(Importer.getToContext(), DC,
4468                                                     Loc, Name, TemplateParams,
4469                                                     D2Templated,
4470                                                     /*PrevDecl=*/nullptr);
4471   D2Templated->setDescribedClassTemplate(D2);
4472
4473   D2->setAccess(D->getAccess());
4474   D2->setLexicalDeclContext(LexicalDC);
4475   LexicalDC->addDeclInternal(D2);
4476
4477   // Note the relationship between the class templates.
4478   Importer.Imported(D, D2);
4479   Importer.Imported(DTemplated, D2Templated);
4480
4481   if (DTemplated->isCompleteDefinition() &&
4482       !D2Templated->isCompleteDefinition()) {
4483     // FIXME: Import definition!
4484   }
4485
4486   return D2;
4487 }
4488
4489 Decl *ASTNodeImporter::VisitClassTemplateSpecializationDecl(
4490                                           ClassTemplateSpecializationDecl *D) {
4491   // If this record has a definition in the translation unit we're coming from,
4492   // but this particular declaration is not that definition, import the
4493   // definition and map to that.
4494   TagDecl *Definition = D->getDefinition();
4495   if (Definition && Definition != D) {
4496     Decl *ImportedDef = Importer.Import(Definition);
4497     if (!ImportedDef)
4498       return nullptr;
4499
4500     return Importer.Imported(D, ImportedDef);
4501   }
4502
4503   ClassTemplateDecl *ClassTemplate
4504     = cast_or_null<ClassTemplateDecl>(Importer.Import(
4505                                                  D->getSpecializedTemplate()));
4506   if (!ClassTemplate)
4507     return nullptr;
4508
4509   // Import the context of this declaration.
4510   DeclContext *DC = ClassTemplate->getDeclContext();
4511   if (!DC)
4512     return nullptr;
4513
4514   DeclContext *LexicalDC = DC;
4515   if (D->getDeclContext() != D->getLexicalDeclContext()) {
4516     LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
4517     if (!LexicalDC)
4518       return nullptr;
4519   }
4520
4521   // Import the location of this declaration.
4522   SourceLocation StartLoc = Importer.Import(D->getLocStart());
4523   SourceLocation IdLoc = Importer.Import(D->getLocation());
4524
4525   // Import template arguments.
4526   SmallVector<TemplateArgument, 2> TemplateArgs;
4527   if (ImportTemplateArguments(D->getTemplateArgs().data(),
4528                               D->getTemplateArgs().size(),
4529                               TemplateArgs))
4530     return nullptr;
4531
4532   // Try to find an existing specialization with these template arguments.
4533   void *InsertPos = nullptr;
4534   ClassTemplateSpecializationDecl *D2
4535     = ClassTemplate->findSpecialization(TemplateArgs, InsertPos);
4536   if (D2) {
4537     // We already have a class template specialization with these template
4538     // arguments.
4539
4540     // FIXME: Check for specialization vs. instantiation errors.
4541
4542     if (RecordDecl *FoundDef = D2->getDefinition()) {
4543       if (!D->isCompleteDefinition() || IsStructuralMatch(D, FoundDef)) {
4544         // The record types structurally match, or the "from" translation
4545         // unit only had a forward declaration anyway; call it the same
4546         // function.
4547         return Importer.Imported(D, FoundDef);
4548       }
4549     }
4550   } else {
4551     // Create a new specialization.
4552     D2 = ClassTemplateSpecializationDecl::Create(Importer.getToContext(),
4553                                                  D->getTagKind(), DC,
4554                                                  StartLoc, IdLoc,
4555                                                  ClassTemplate,
4556                                                  TemplateArgs.data(),
4557                                                  TemplateArgs.size(),
4558                                                  /*PrevDecl=*/nullptr);
4559     D2->setSpecializationKind(D->getSpecializationKind());
4560
4561     // Add this specialization to the class template.
4562     ClassTemplate->AddSpecialization(D2, InsertPos);
4563
4564     // Import the qualifier, if any.
4565     D2->setQualifierInfo(Importer.Import(D->getQualifierLoc()));
4566
4567     // Add the specialization to this context.
4568     D2->setLexicalDeclContext(LexicalDC);
4569     LexicalDC->addDeclInternal(D2);
4570   }
4571   Importer.Imported(D, D2);
4572
4573   if (D->isCompleteDefinition() && ImportDefinition(D, D2))
4574     return nullptr;
4575
4576   return D2;
4577 }
4578
4579 Decl *ASTNodeImporter::VisitVarTemplateDecl(VarTemplateDecl *D) {
4580   // If this variable has a definition in the translation unit we're coming
4581   // from,
4582   // but this particular declaration is not that definition, import the
4583   // definition and map to that.
4584   VarDecl *Definition =
4585       cast_or_null<VarDecl>(D->getTemplatedDecl()->getDefinition());
4586   if (Definition && Definition != D->getTemplatedDecl()) {
4587     Decl *ImportedDef = Importer.Import(Definition->getDescribedVarTemplate());
4588     if (!ImportedDef)
4589       return nullptr;
4590
4591     return Importer.Imported(D, ImportedDef);
4592   }
4593
4594   // Import the major distinguishing characteristics of this variable template.
4595   DeclContext *DC, *LexicalDC;
4596   DeclarationName Name;
4597   SourceLocation Loc;
4598   NamedDecl *ToD;
4599   if (ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
4600     return nullptr;
4601   if (ToD)
4602     return ToD;
4603
4604   // We may already have a template of the same name; try to find and match it.
4605   assert(!DC->isFunctionOrMethod() &&
4606          "Variable templates cannot be declared at function scope");
4607   SmallVector<NamedDecl *, 4> ConflictingDecls;
4608   SmallVector<NamedDecl *, 2> FoundDecls;
4609   DC->getRedeclContext()->localUncachedLookup(Name, FoundDecls);
4610   for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
4611     if (!FoundDecls[I]->isInIdentifierNamespace(Decl::IDNS_Ordinary))
4612       continue;
4613
4614     Decl *Found = FoundDecls[I];
4615     if (VarTemplateDecl *FoundTemplate = dyn_cast<VarTemplateDecl>(Found)) {
4616       if (IsStructuralMatch(D, FoundTemplate)) {
4617         // The variable templates structurally match; call it the same template.
4618         Importer.Imported(D->getTemplatedDecl(),
4619                           FoundTemplate->getTemplatedDecl());
4620         return Importer.Imported(D, FoundTemplate);
4621       }
4622     }
4623
4624     ConflictingDecls.push_back(FoundDecls[I]);
4625   }
4626
4627   if (!ConflictingDecls.empty()) {
4628     Name = Importer.HandleNameConflict(Name, DC, Decl::IDNS_Ordinary,
4629                                        ConflictingDecls.data(),
4630                                        ConflictingDecls.size());
4631   }
4632
4633   if (!Name)
4634     return nullptr;
4635
4636   VarDecl *DTemplated = D->getTemplatedDecl();
4637
4638   // Import the type.
4639   QualType T = Importer.Import(DTemplated->getType());
4640   if (T.isNull())
4641     return nullptr;
4642
4643   // Create the declaration that is being templated.
4644   SourceLocation StartLoc = Importer.Import(DTemplated->getLocStart());
4645   SourceLocation IdLoc = Importer.Import(DTemplated->getLocation());
4646   TypeSourceInfo *TInfo = Importer.Import(DTemplated->getTypeSourceInfo());
4647   VarDecl *D2Templated = VarDecl::Create(Importer.getToContext(), DC, StartLoc,
4648                                          IdLoc, Name.getAsIdentifierInfo(), T,
4649                                          TInfo, DTemplated->getStorageClass());
4650   D2Templated->setAccess(DTemplated->getAccess());
4651   D2Templated->setQualifierInfo(Importer.Import(DTemplated->getQualifierLoc()));
4652   D2Templated->setLexicalDeclContext(LexicalDC);
4653
4654   // Importer.Imported(DTemplated, D2Templated);
4655   // LexicalDC->addDeclInternal(D2Templated);
4656
4657   // Merge the initializer.
4658   if (ImportDefinition(DTemplated, D2Templated))
4659     return nullptr;
4660
4661   // Create the variable template declaration itself.
4662   TemplateParameterList *TemplateParams =
4663       ImportTemplateParameterList(D->getTemplateParameters());
4664   if (!TemplateParams)
4665     return nullptr;
4666
4667   VarTemplateDecl *D2 = VarTemplateDecl::Create(
4668       Importer.getToContext(), DC, Loc, Name, TemplateParams, D2Templated);
4669   D2Templated->setDescribedVarTemplate(D2);
4670
4671   D2->setAccess(D->getAccess());
4672   D2->setLexicalDeclContext(LexicalDC);
4673   LexicalDC->addDeclInternal(D2);
4674
4675   // Note the relationship between the variable templates.
4676   Importer.Imported(D, D2);
4677   Importer.Imported(DTemplated, D2Templated);
4678
4679   if (DTemplated->isThisDeclarationADefinition() &&
4680       !D2Templated->isThisDeclarationADefinition()) {
4681     // FIXME: Import definition!
4682   }
4683
4684   return D2;
4685 }
4686
4687 Decl *ASTNodeImporter::VisitVarTemplateSpecializationDecl(
4688     VarTemplateSpecializationDecl *D) {
4689   // If this record has a definition in the translation unit we're coming from,
4690   // but this particular declaration is not that definition, import the
4691   // definition and map to that.
4692   VarDecl *Definition = D->getDefinition();
4693   if (Definition && Definition != D) {
4694     Decl *ImportedDef = Importer.Import(Definition);
4695     if (!ImportedDef)
4696       return nullptr;
4697
4698     return Importer.Imported(D, ImportedDef);
4699   }
4700
4701   VarTemplateDecl *VarTemplate = cast_or_null<VarTemplateDecl>(
4702       Importer.Import(D->getSpecializedTemplate()));
4703   if (!VarTemplate)
4704     return nullptr;
4705
4706   // Import the context of this declaration.
4707   DeclContext *DC = VarTemplate->getDeclContext();
4708   if (!DC)
4709     return nullptr;
4710
4711   DeclContext *LexicalDC = DC;
4712   if (D->getDeclContext() != D->getLexicalDeclContext()) {
4713     LexicalDC = Importer.ImportContext(D->getLexicalDeclContext());
4714     if (!LexicalDC)
4715       return nullptr;
4716   }
4717
4718   // Import the location of this declaration.
4719   SourceLocation StartLoc = Importer.Import(D->getLocStart());
4720   SourceLocation IdLoc = Importer.Import(D->getLocation());
4721
4722   // Import template arguments.
4723   SmallVector<TemplateArgument, 2> TemplateArgs;
4724   if (ImportTemplateArguments(D->getTemplateArgs().data(),
4725                               D->getTemplateArgs().size(), TemplateArgs))
4726     return nullptr;
4727
4728   // Try to find an existing specialization with these template arguments.
4729   void *InsertPos = nullptr;
4730   VarTemplateSpecializationDecl *D2 = VarTemplate->findSpecialization(
4731       TemplateArgs, InsertPos);
4732   if (D2) {
4733     // We already have a variable template specialization with these template
4734     // arguments.
4735
4736     // FIXME: Check for specialization vs. instantiation errors.
4737
4738     if (VarDecl *FoundDef = D2->getDefinition()) {
4739       if (!D->isThisDeclarationADefinition() ||
4740           IsStructuralMatch(D, FoundDef)) {
4741         // The record types structurally match, or the "from" translation
4742         // unit only had a forward declaration anyway; call it the same
4743         // variable.
4744         return Importer.Imported(D, FoundDef);
4745       }
4746     }
4747   } else {
4748
4749     // Import the type.
4750     QualType T = Importer.Import(D->getType());
4751     if (T.isNull())
4752       return nullptr;
4753     TypeSourceInfo *TInfo = Importer.Import(D->getTypeSourceInfo());
4754
4755     // Create a new specialization.
4756     D2 = VarTemplateSpecializationDecl::Create(
4757         Importer.getToContext(), DC, StartLoc, IdLoc, VarTemplate, T, TInfo,
4758         D->getStorageClass(), TemplateArgs.data(), TemplateArgs.size());
4759     D2->setSpecializationKind(D->getSpecializationKind());
4760     D2->setTemplateArgsInfo(D->getTemplateArgsInfo());
4761
4762     // Add this specialization to the class template.
4763     VarTemplate->AddSpecialization(D2, InsertPos);
4764
4765     // Import the qualifier, if any.
4766     D2->setQualifierInfo(Importer.Import(D->getQualifierLoc()));
4767
4768     // Add the specialization to this context.
4769     D2->setLexicalDeclContext(LexicalDC);
4770     LexicalDC->addDeclInternal(D2);
4771   }
4772   Importer.Imported(D, D2);
4773
4774   if (D->isThisDeclarationADefinition() && ImportDefinition(D, D2))
4775     return nullptr;
4776
4777   return D2;
4778 }
4779
4780 //----------------------------------------------------------------------------
4781 // Import Statements
4782 //----------------------------------------------------------------------------
4783
4784 DeclGroupRef ASTNodeImporter::ImportDeclGroup(DeclGroupRef DG) {
4785   if (DG.isNull())
4786     return DeclGroupRef::Create(Importer.getToContext(), nullptr, 0);
4787   size_t NumDecls = DG.end() - DG.begin();
4788   SmallVector<Decl *, 1> ToDecls(NumDecls);
4789   auto &_Importer = this->Importer;
4790   std::transform(DG.begin(), DG.end(), ToDecls.begin(),
4791     [&_Importer](Decl *D) -> Decl * {
4792       return _Importer.Import(D);
4793     });
4794   return DeclGroupRef::Create(Importer.getToContext(),
4795                               ToDecls.begin(),
4796                               NumDecls);
4797 }
4798
4799  Stmt *ASTNodeImporter::VisitStmt(Stmt *S) {
4800    Importer.FromDiag(S->getLocStart(), diag::err_unsupported_ast_node)
4801      << S->getStmtClassName();
4802    return nullptr;
4803  }
4804
4805
4806 Stmt *ASTNodeImporter::VisitGCCAsmStmt(GCCAsmStmt *S) {
4807   SmallVector<IdentifierInfo *, 4> Names;
4808   for (unsigned I = 0, E = S->getNumOutputs(); I != E; I++) {
4809     IdentifierInfo *ToII = Importer.Import(S->getOutputIdentifier(I));
4810     if (!ToII)
4811       return nullptr;
4812     Names.push_back(ToII);
4813   }
4814   for (unsigned I = 0, E = S->getNumInputs(); I != E; I++) {
4815     IdentifierInfo *ToII = Importer.Import(S->getInputIdentifier(I));
4816     if (!ToII)
4817       return nullptr;
4818     Names.push_back(ToII);
4819   }
4820
4821   SmallVector<StringLiteral *, 4> Clobbers;
4822   for (unsigned I = 0, E = S->getNumClobbers(); I != E; I++) {
4823     StringLiteral *Clobber = cast_or_null<StringLiteral>(
4824           Importer.Import(S->getClobberStringLiteral(I)));
4825     if (!Clobber)
4826       return nullptr;
4827     Clobbers.push_back(Clobber);
4828   }
4829
4830   SmallVector<StringLiteral *, 4> Constraints;
4831   for (unsigned I = 0, E = S->getNumOutputs(); I != E; I++) {
4832     StringLiteral *Output = cast_or_null<StringLiteral>(
4833           Importer.Import(S->getOutputConstraintLiteral(I)));
4834     if (!Output)
4835       return nullptr;
4836     Constraints.push_back(Output);
4837   }
4838
4839   for (unsigned I = 0, E = S->getNumInputs(); I != E; I++) {
4840     StringLiteral *Input = cast_or_null<StringLiteral>(
4841           Importer.Import(S->getInputConstraintLiteral(I)));
4842     if (!Input)
4843       return nullptr;
4844     Constraints.push_back(Input);
4845   }
4846
4847   SmallVector<Expr *, 4> Exprs(S->getNumOutputs() + S->getNumInputs());
4848   if (ImportArrayChecked(S->begin_outputs(), S->end_outputs(), Exprs.begin()))
4849     return nullptr;
4850
4851   if (ImportArrayChecked(S->begin_inputs(), S->end_inputs(),
4852                          Exprs.begin() + S->getNumOutputs()))
4853     return nullptr;
4854
4855   StringLiteral *AsmStr = cast_or_null<StringLiteral>(
4856         Importer.Import(S->getAsmString()));
4857   if (!AsmStr)
4858     return nullptr;
4859
4860   return new (Importer.getToContext()) GCCAsmStmt(
4861         Importer.getToContext(),
4862         Importer.Import(S->getAsmLoc()),
4863         S->isSimple(),
4864         S->isVolatile(),
4865         S->getNumOutputs(),
4866         S->getNumInputs(),
4867         Names.data(),
4868         Constraints.data(),
4869         Exprs.data(),
4870         AsmStr,
4871         S->getNumClobbers(),
4872         Clobbers.data(),
4873         Importer.Import(S->getRParenLoc()));
4874 }
4875
4876 Stmt *ASTNodeImporter::VisitDeclStmt(DeclStmt *S) {
4877   DeclGroupRef ToDG = ImportDeclGroup(S->getDeclGroup());
4878   for (Decl *ToD : ToDG) {
4879     if (!ToD)
4880       return nullptr;
4881   }
4882   SourceLocation ToStartLoc = Importer.Import(S->getStartLoc());
4883   SourceLocation ToEndLoc = Importer.Import(S->getEndLoc());
4884   return new (Importer.getToContext()) DeclStmt(ToDG, ToStartLoc, ToEndLoc);
4885 }
4886
4887 Stmt *ASTNodeImporter::VisitNullStmt(NullStmt *S) {
4888   SourceLocation ToSemiLoc = Importer.Import(S->getSemiLoc());
4889   return new (Importer.getToContext()) NullStmt(ToSemiLoc,
4890                                                 S->hasLeadingEmptyMacro());
4891 }
4892
4893 Stmt *ASTNodeImporter::VisitCompoundStmt(CompoundStmt *S) {
4894   llvm::SmallVector<Stmt *, 8> ToStmts(S->size());
4895
4896   if (ImportArrayChecked(S->body_begin(), S->body_end(), ToStmts.begin()))
4897     return nullptr;
4898
4899   SourceLocation ToLBraceLoc = Importer.Import(S->getLBracLoc());
4900   SourceLocation ToRBraceLoc = Importer.Import(S->getRBracLoc());
4901   return new (Importer.getToContext()) CompoundStmt(Importer.getToContext(),
4902                                                     ToStmts,
4903                                                     ToLBraceLoc, ToRBraceLoc);
4904 }
4905
4906 Stmt *ASTNodeImporter::VisitCaseStmt(CaseStmt *S) {
4907   Expr *ToLHS = Importer.Import(S->getLHS());
4908   if (!ToLHS)
4909     return nullptr;
4910   Expr *ToRHS = Importer.Import(S->getRHS());
4911   if (!ToRHS && S->getRHS())
4912     return nullptr;
4913   SourceLocation ToCaseLoc = Importer.Import(S->getCaseLoc());
4914   SourceLocation ToEllipsisLoc = Importer.Import(S->getEllipsisLoc());
4915   SourceLocation ToColonLoc = Importer.Import(S->getColonLoc());
4916   return new (Importer.getToContext()) CaseStmt(ToLHS, ToRHS,
4917                                                 ToCaseLoc, ToEllipsisLoc,
4918                                                 ToColonLoc);
4919 }
4920
4921 Stmt *ASTNodeImporter::VisitDefaultStmt(DefaultStmt *S) {
4922   SourceLocation ToDefaultLoc = Importer.Import(S->getDefaultLoc());
4923   SourceLocation ToColonLoc = Importer.Import(S->getColonLoc());
4924   Stmt *ToSubStmt = Importer.Import(S->getSubStmt());
4925   if (!ToSubStmt && S->getSubStmt())
4926     return nullptr;
4927   return new (Importer.getToContext()) DefaultStmt(ToDefaultLoc, ToColonLoc,
4928                                                    ToSubStmt);
4929 }
4930
4931 Stmt *ASTNodeImporter::VisitLabelStmt(LabelStmt *S) {
4932   SourceLocation ToIdentLoc = Importer.Import(S->getIdentLoc());
4933   LabelDecl *ToLabelDecl =
4934     cast_or_null<LabelDecl>(Importer.Import(S->getDecl()));
4935   if (!ToLabelDecl && S->getDecl())
4936     return nullptr;
4937   Stmt *ToSubStmt = Importer.Import(S->getSubStmt());
4938   if (!ToSubStmt && S->getSubStmt())
4939     return nullptr;
4940   return new (Importer.getToContext()) LabelStmt(ToIdentLoc, ToLabelDecl,
4941                                                  ToSubStmt);
4942 }
4943
4944 Stmt *ASTNodeImporter::VisitAttributedStmt(AttributedStmt *S) {
4945   SourceLocation ToAttrLoc = Importer.Import(S->getAttrLoc());
4946   ArrayRef<const Attr*> FromAttrs(S->getAttrs());
4947   SmallVector<const Attr *, 1> ToAttrs(FromAttrs.size());
4948   ASTContext &_ToContext = Importer.getToContext();
4949   std::transform(FromAttrs.begin(), FromAttrs.end(), ToAttrs.begin(),
4950     [&_ToContext](const Attr *A) -> const Attr * {
4951       return A->clone(_ToContext);
4952     });
4953   for (const Attr *ToA : ToAttrs) {
4954     if (!ToA)
4955       return nullptr;
4956   }
4957   Stmt *ToSubStmt = Importer.Import(S->getSubStmt());
4958   if (!ToSubStmt && S->getSubStmt())
4959     return nullptr;
4960   return AttributedStmt::Create(Importer.getToContext(), ToAttrLoc,
4961                                 ToAttrs, ToSubStmt);
4962 }
4963
4964 Stmt *ASTNodeImporter::VisitIfStmt(IfStmt *S) {
4965   SourceLocation ToIfLoc = Importer.Import(S->getIfLoc());
4966   VarDecl *ToConditionVariable = nullptr;
4967   if (VarDecl *FromConditionVariable = S->getConditionVariable()) {
4968     ToConditionVariable =
4969       dyn_cast_or_null<VarDecl>(Importer.Import(FromConditionVariable));
4970     if (!ToConditionVariable)
4971       return nullptr;
4972   }
4973   Expr *ToCondition = Importer.Import(S->getCond());
4974   if (!ToCondition && S->getCond())
4975     return nullptr;
4976   Stmt *ToThenStmt = Importer.Import(S->getThen());
4977   if (!ToThenStmt && S->getThen())
4978     return nullptr;
4979   SourceLocation ToElseLoc = Importer.Import(S->getElseLoc());
4980   Stmt *ToElseStmt = Importer.Import(S->getElse());
4981   if (!ToElseStmt && S->getElse())
4982     return nullptr;
4983   return new (Importer.getToContext()) IfStmt(Importer.getToContext(),
4984                                               ToIfLoc, S->isConstexpr(),
4985                                               ToConditionVariable,
4986                                               ToCondition, ToThenStmt,
4987                                               ToElseLoc, ToElseStmt);
4988 }
4989
4990 Stmt *ASTNodeImporter::VisitSwitchStmt(SwitchStmt *S) {
4991   VarDecl *ToConditionVariable = nullptr;
4992   if (VarDecl *FromConditionVariable = S->getConditionVariable()) {
4993     ToConditionVariable =
4994       dyn_cast_or_null<VarDecl>(Importer.Import(FromConditionVariable));
4995     if (!ToConditionVariable)
4996       return nullptr;
4997   }
4998   Expr *ToCondition = Importer.Import(S->getCond());
4999   if (!ToCondition && S->getCond())
5000     return nullptr;
5001   SwitchStmt *ToStmt = new (Importer.getToContext()) SwitchStmt(
5002                          Importer.getToContext(), ToConditionVariable,
5003                          ToCondition);
5004   Stmt *ToBody = Importer.Import(S->getBody());
5005   if (!ToBody && S->getBody())
5006     return nullptr;
5007   ToStmt->setBody(ToBody);
5008   ToStmt->setSwitchLoc(Importer.Import(S->getSwitchLoc()));
5009   // Now we have to re-chain the cases.
5010   SwitchCase *LastChainedSwitchCase = nullptr;
5011   for (SwitchCase *SC = S->getSwitchCaseList(); SC != nullptr;
5012        SC = SC->getNextSwitchCase()) {
5013     SwitchCase *ToSC = dyn_cast_or_null<SwitchCase>(Importer.Import(SC));
5014     if (!ToSC)
5015       return nullptr;
5016     if (LastChainedSwitchCase)
5017       LastChainedSwitchCase->setNextSwitchCase(ToSC);
5018     else
5019       ToStmt->setSwitchCaseList(ToSC);
5020     LastChainedSwitchCase = ToSC;
5021   }
5022   return ToStmt;
5023 }
5024
5025 Stmt *ASTNodeImporter::VisitWhileStmt(WhileStmt *S) {
5026   VarDecl *ToConditionVariable = nullptr;
5027   if (VarDecl *FromConditionVariable = S->getConditionVariable()) {
5028     ToConditionVariable =
5029       dyn_cast_or_null<VarDecl>(Importer.Import(FromConditionVariable));
5030     if (!ToConditionVariable)
5031       return nullptr;
5032   }
5033   Expr *ToCondition = Importer.Import(S->getCond());
5034   if (!ToCondition && S->getCond())
5035     return nullptr;
5036   Stmt *ToBody = Importer.Import(S->getBody());
5037   if (!ToBody && S->getBody())
5038     return nullptr;
5039   SourceLocation ToWhileLoc = Importer.Import(S->getWhileLoc());
5040   return new (Importer.getToContext()) WhileStmt(Importer.getToContext(),
5041                                                  ToConditionVariable,
5042                                                  ToCondition, ToBody,
5043                                                  ToWhileLoc);
5044 }
5045
5046 Stmt *ASTNodeImporter::VisitDoStmt(DoStmt *S) {
5047   Stmt *ToBody = Importer.Import(S->getBody());
5048   if (!ToBody && S->getBody())
5049     return nullptr;
5050   Expr *ToCondition = Importer.Import(S->getCond());
5051   if (!ToCondition && S->getCond())
5052     return nullptr;
5053   SourceLocation ToDoLoc = Importer.Import(S->getDoLoc());
5054   SourceLocation ToWhileLoc = Importer.Import(S->getWhileLoc());
5055   SourceLocation ToRParenLoc = Importer.Import(S->getRParenLoc());
5056   return new (Importer.getToContext()) DoStmt(ToBody, ToCondition,
5057                                               ToDoLoc, ToWhileLoc,
5058                                               ToRParenLoc);
5059 }
5060
5061 Stmt *ASTNodeImporter::VisitForStmt(ForStmt *S) {
5062   Stmt *ToInit = Importer.Import(S->getInit());
5063   if (!ToInit && S->getInit())
5064     return nullptr;
5065   Expr *ToCondition = Importer.Import(S->getCond());
5066   if (!ToCondition && S->getCond())
5067     return nullptr;
5068   VarDecl *ToConditionVariable = nullptr;
5069   if (VarDecl *FromConditionVariable = S->getConditionVariable()) {
5070     ToConditionVariable =
5071       dyn_cast_or_null<VarDecl>(Importer.Import(FromConditionVariable));
5072     if (!ToConditionVariable)
5073       return nullptr;
5074   }
5075   Expr *ToInc = Importer.Import(S->getInc());
5076   if (!ToInc && S->getInc())
5077     return nullptr;
5078   Stmt *ToBody = Importer.Import(S->getBody());
5079   if (!ToBody && S->getBody())
5080     return nullptr;
5081   SourceLocation ToForLoc = Importer.Import(S->getForLoc());
5082   SourceLocation ToLParenLoc = Importer.Import(S->getLParenLoc());
5083   SourceLocation ToRParenLoc = Importer.Import(S->getRParenLoc());
5084   return new (Importer.getToContext()) ForStmt(Importer.getToContext(),
5085                                                ToInit, ToCondition,
5086                                                ToConditionVariable,
5087                                                ToInc, ToBody,
5088                                                ToForLoc, ToLParenLoc,
5089                                                ToRParenLoc);
5090 }
5091
5092 Stmt *ASTNodeImporter::VisitGotoStmt(GotoStmt *S) {
5093   LabelDecl *ToLabel = nullptr;
5094   if (LabelDecl *FromLabel = S->getLabel()) {
5095     ToLabel = dyn_cast_or_null<LabelDecl>(Importer.Import(FromLabel));
5096     if (!ToLabel)
5097       return nullptr;
5098   }
5099   SourceLocation ToGotoLoc = Importer.Import(S->getGotoLoc());
5100   SourceLocation ToLabelLoc = Importer.Import(S->getLabelLoc());
5101   return new (Importer.getToContext()) GotoStmt(ToLabel,
5102                                                 ToGotoLoc, ToLabelLoc);
5103 }
5104
5105 Stmt *ASTNodeImporter::VisitIndirectGotoStmt(IndirectGotoStmt *S) {
5106   SourceLocation ToGotoLoc = Importer.Import(S->getGotoLoc());
5107   SourceLocation ToStarLoc = Importer.Import(S->getStarLoc());
5108   Expr *ToTarget = Importer.Import(S->getTarget());
5109   if (!ToTarget && S->getTarget())
5110     return nullptr;
5111   return new (Importer.getToContext()) IndirectGotoStmt(ToGotoLoc, ToStarLoc,
5112                                                         ToTarget);
5113 }
5114
5115 Stmt *ASTNodeImporter::VisitContinueStmt(ContinueStmt *S) {
5116   SourceLocation ToContinueLoc = Importer.Import(S->getContinueLoc());
5117   return new (Importer.getToContext()) ContinueStmt(ToContinueLoc);
5118 }
5119
5120 Stmt *ASTNodeImporter::VisitBreakStmt(BreakStmt *S) {
5121   SourceLocation ToBreakLoc = Importer.Import(S->getBreakLoc());
5122   return new (Importer.getToContext()) BreakStmt(ToBreakLoc);
5123 }
5124
5125 Stmt *ASTNodeImporter::VisitReturnStmt(ReturnStmt *S) {
5126   SourceLocation ToRetLoc = Importer.Import(S->getReturnLoc());
5127   Expr *ToRetExpr = Importer.Import(S->getRetValue());
5128   if (!ToRetExpr && S->getRetValue())
5129     return nullptr;
5130   VarDecl *NRVOCandidate = const_cast<VarDecl*>(S->getNRVOCandidate());
5131   VarDecl *ToNRVOCandidate = cast_or_null<VarDecl>(Importer.Import(NRVOCandidate));
5132   if (!ToNRVOCandidate && NRVOCandidate)
5133     return nullptr;
5134   return new (Importer.getToContext()) ReturnStmt(ToRetLoc, ToRetExpr,
5135                                                   ToNRVOCandidate);
5136 }
5137
5138 Stmt *ASTNodeImporter::VisitCXXCatchStmt(CXXCatchStmt *S) {
5139   SourceLocation ToCatchLoc = Importer.Import(S->getCatchLoc());
5140   VarDecl *ToExceptionDecl = nullptr;
5141   if (VarDecl *FromExceptionDecl = S->getExceptionDecl()) {
5142     ToExceptionDecl =
5143       dyn_cast_or_null<VarDecl>(Importer.Import(FromExceptionDecl));
5144     if (!ToExceptionDecl)
5145       return nullptr;
5146   }
5147   Stmt *ToHandlerBlock = Importer.Import(S->getHandlerBlock());
5148   if (!ToHandlerBlock && S->getHandlerBlock())
5149     return nullptr;
5150   return new (Importer.getToContext()) CXXCatchStmt(ToCatchLoc,
5151                                                     ToExceptionDecl,
5152                                                     ToHandlerBlock);
5153 }
5154
5155 Stmt *ASTNodeImporter::VisitCXXTryStmt(CXXTryStmt *S) {
5156   SourceLocation ToTryLoc = Importer.Import(S->getTryLoc());
5157   Stmt *ToTryBlock = Importer.Import(S->getTryBlock());
5158   if (!ToTryBlock && S->getTryBlock())
5159     return nullptr;
5160   SmallVector<Stmt *, 1> ToHandlers(S->getNumHandlers());
5161   for (unsigned HI = 0, HE = S->getNumHandlers(); HI != HE; ++HI) {
5162     CXXCatchStmt *FromHandler = S->getHandler(HI);
5163     if (Stmt *ToHandler = Importer.Import(FromHandler))
5164       ToHandlers[HI] = ToHandler;
5165     else
5166       return nullptr;
5167   }
5168   return CXXTryStmt::Create(Importer.getToContext(), ToTryLoc, ToTryBlock,
5169                             ToHandlers);
5170 }
5171
5172 Stmt *ASTNodeImporter::VisitCXXForRangeStmt(CXXForRangeStmt *S) {
5173   DeclStmt *ToRange =
5174     dyn_cast_or_null<DeclStmt>(Importer.Import(S->getRangeStmt()));
5175   if (!ToRange && S->getRangeStmt())
5176     return nullptr;
5177   DeclStmt *ToBegin =
5178     dyn_cast_or_null<DeclStmt>(Importer.Import(S->getBeginStmt()));
5179   if (!ToBegin && S->getBeginStmt())
5180     return nullptr;
5181   DeclStmt *ToEnd =
5182     dyn_cast_or_null<DeclStmt>(Importer.Import(S->getEndStmt()));
5183   if (!ToEnd && S->getEndStmt())
5184     return nullptr;
5185   Expr *ToCond = Importer.Import(S->getCond());
5186   if (!ToCond && S->getCond())
5187     return nullptr;
5188   Expr *ToInc = Importer.Import(S->getInc());
5189   if (!ToInc && S->getInc())
5190     return nullptr;
5191   DeclStmt *ToLoopVar =
5192     dyn_cast_or_null<DeclStmt>(Importer.Import(S->getLoopVarStmt()));
5193   if (!ToLoopVar && S->getLoopVarStmt())
5194     return nullptr;
5195   Stmt *ToBody = Importer.Import(S->getBody());
5196   if (!ToBody && S->getBody())
5197     return nullptr;
5198   SourceLocation ToForLoc = Importer.Import(S->getForLoc());
5199   SourceLocation ToCoawaitLoc = Importer.Import(S->getCoawaitLoc());
5200   SourceLocation ToColonLoc = Importer.Import(S->getColonLoc());
5201   SourceLocation ToRParenLoc = Importer.Import(S->getRParenLoc());
5202   return new (Importer.getToContext()) CXXForRangeStmt(ToRange, ToBegin, ToEnd,
5203                                                        ToCond, ToInc,
5204                                                        ToLoopVar, ToBody,
5205                                                        ToForLoc, ToCoawaitLoc,
5206                                                        ToColonLoc, ToRParenLoc);
5207 }
5208
5209 Stmt *ASTNodeImporter::VisitObjCForCollectionStmt(ObjCForCollectionStmt *S) {
5210   Stmt *ToElem = Importer.Import(S->getElement());
5211   if (!ToElem && S->getElement())
5212     return nullptr;
5213   Expr *ToCollect = Importer.Import(S->getCollection());
5214   if (!ToCollect && S->getCollection())
5215     return nullptr;
5216   Stmt *ToBody = Importer.Import(S->getBody());
5217   if (!ToBody && S->getBody())
5218     return nullptr;
5219   SourceLocation ToForLoc = Importer.Import(S->getForLoc());
5220   SourceLocation ToRParenLoc = Importer.Import(S->getRParenLoc());
5221   return new (Importer.getToContext()) ObjCForCollectionStmt(ToElem,
5222                                                              ToCollect,
5223                                                              ToBody, ToForLoc,
5224                                                              ToRParenLoc);
5225 }
5226
5227 Stmt *ASTNodeImporter::VisitObjCAtCatchStmt(ObjCAtCatchStmt *S) {
5228   SourceLocation ToAtCatchLoc = Importer.Import(S->getAtCatchLoc());
5229   SourceLocation ToRParenLoc = Importer.Import(S->getRParenLoc());
5230   VarDecl *ToExceptionDecl = nullptr;
5231   if (VarDecl *FromExceptionDecl = S->getCatchParamDecl()) {
5232     ToExceptionDecl =
5233       dyn_cast_or_null<VarDecl>(Importer.Import(FromExceptionDecl));
5234     if (!ToExceptionDecl)
5235       return nullptr;
5236   }
5237   Stmt *ToBody = Importer.Import(S->getCatchBody());
5238   if (!ToBody && S->getCatchBody())
5239     return nullptr;
5240   return new (Importer.getToContext()) ObjCAtCatchStmt(ToAtCatchLoc,
5241                                                        ToRParenLoc,
5242                                                        ToExceptionDecl,
5243                                                        ToBody);
5244 }
5245
5246 Stmt *ASTNodeImporter::VisitObjCAtFinallyStmt(ObjCAtFinallyStmt *S) {
5247   SourceLocation ToAtFinallyLoc = Importer.Import(S->getAtFinallyLoc());
5248   Stmt *ToAtFinallyStmt = Importer.Import(S->getFinallyBody());
5249   if (!ToAtFinallyStmt && S->getFinallyBody())
5250     return nullptr;
5251   return new (Importer.getToContext()) ObjCAtFinallyStmt(ToAtFinallyLoc,
5252                                                          ToAtFinallyStmt);
5253 }
5254
5255 Stmt *ASTNodeImporter::VisitObjCAtTryStmt(ObjCAtTryStmt *S) {
5256   SourceLocation ToAtTryLoc = Importer.Import(S->getAtTryLoc());
5257   Stmt *ToAtTryStmt = Importer.Import(S->getTryBody());
5258   if (!ToAtTryStmt && S->getTryBody())
5259     return nullptr;
5260   SmallVector<Stmt *, 1> ToCatchStmts(S->getNumCatchStmts());
5261   for (unsigned CI = 0, CE = S->getNumCatchStmts(); CI != CE; ++CI) {
5262     ObjCAtCatchStmt *FromCatchStmt = S->getCatchStmt(CI);
5263     if (Stmt *ToCatchStmt = Importer.Import(FromCatchStmt))
5264       ToCatchStmts[CI] = ToCatchStmt;
5265     else
5266       return nullptr;
5267   }
5268   Stmt *ToAtFinallyStmt = Importer.Import(S->getFinallyStmt());
5269   if (!ToAtFinallyStmt && S->getFinallyStmt())
5270     return nullptr;
5271   return ObjCAtTryStmt::Create(Importer.getToContext(),
5272                                ToAtTryLoc, ToAtTryStmt,
5273                                ToCatchStmts.begin(), ToCatchStmts.size(),
5274                                ToAtFinallyStmt);
5275 }
5276
5277 Stmt *ASTNodeImporter::VisitObjCAtSynchronizedStmt
5278   (ObjCAtSynchronizedStmt *S) {
5279   SourceLocation ToAtSynchronizedLoc =
5280     Importer.Import(S->getAtSynchronizedLoc());
5281   Expr *ToSynchExpr = Importer.Import(S->getSynchExpr());
5282   if (!ToSynchExpr && S->getSynchExpr())
5283     return nullptr;
5284   Stmt *ToSynchBody = Importer.Import(S->getSynchBody());
5285   if (!ToSynchBody && S->getSynchBody())
5286     return nullptr;
5287   return new (Importer.getToContext()) ObjCAtSynchronizedStmt(
5288     ToAtSynchronizedLoc, ToSynchExpr, ToSynchBody);
5289 }
5290
5291 Stmt *ASTNodeImporter::VisitObjCAtThrowStmt(ObjCAtThrowStmt *S) {
5292   SourceLocation ToAtThrowLoc = Importer.Import(S->getThrowLoc());
5293   Expr *ToThrow = Importer.Import(S->getThrowExpr());
5294   if (!ToThrow && S->getThrowExpr())
5295     return nullptr;
5296   return new (Importer.getToContext()) ObjCAtThrowStmt(ToAtThrowLoc, ToThrow);
5297 }
5298
5299 Stmt *ASTNodeImporter::VisitObjCAutoreleasePoolStmt
5300   (ObjCAutoreleasePoolStmt *S) {
5301   SourceLocation ToAtLoc = Importer.Import(S->getAtLoc());
5302   Stmt *ToSubStmt = Importer.Import(S->getSubStmt());
5303   if (!ToSubStmt && S->getSubStmt())
5304     return nullptr;
5305   return new (Importer.getToContext()) ObjCAutoreleasePoolStmt(ToAtLoc,
5306                                                                ToSubStmt);
5307 }
5308
5309 //----------------------------------------------------------------------------
5310 // Import Expressions
5311 //----------------------------------------------------------------------------
5312 Expr *ASTNodeImporter::VisitExpr(Expr *E) {
5313   Importer.FromDiag(E->getLocStart(), diag::err_unsupported_ast_node)
5314     << E->getStmtClassName();
5315   return nullptr;
5316 }
5317
5318 Expr *ASTNodeImporter::VisitVAArgExpr(VAArgExpr *E) {
5319   QualType T = Importer.Import(E->getType());
5320   if (T.isNull())
5321     return nullptr;
5322
5323   Expr *SubExpr = Importer.Import(E->getSubExpr());
5324   if (!SubExpr && E->getSubExpr())
5325     return nullptr;
5326
5327   TypeSourceInfo *TInfo = Importer.Import(E->getWrittenTypeInfo());
5328   if (!TInfo)
5329     return nullptr;
5330
5331   return new (Importer.getToContext()) VAArgExpr(
5332         Importer.Import(E->getBuiltinLoc()), SubExpr, TInfo,
5333         Importer.Import(E->getRParenLoc()), T, E->isMicrosoftABI());
5334 }
5335
5336
5337 Expr *ASTNodeImporter::VisitGNUNullExpr(GNUNullExpr *E) {
5338   QualType T = Importer.Import(E->getType());
5339   if (T.isNull())
5340     return nullptr;
5341
5342   return new (Importer.getToContext()) GNUNullExpr(
5343         T, Importer.Import(E->getExprLoc()));
5344 }
5345
5346 Expr *ASTNodeImporter::VisitPredefinedExpr(PredefinedExpr *E) {
5347   QualType T = Importer.Import(E->getType());
5348   if (T.isNull())
5349     return nullptr;
5350
5351   StringLiteral *SL = cast_or_null<StringLiteral>(
5352         Importer.Import(E->getFunctionName()));
5353   if (!SL && E->getFunctionName())
5354     return nullptr;
5355
5356   return new (Importer.getToContext()) PredefinedExpr(
5357         Importer.Import(E->getExprLoc()), T, E->getIdentType(), SL);
5358 }
5359
5360 Expr *ASTNodeImporter::VisitDeclRefExpr(DeclRefExpr *E) {
5361   ValueDecl *ToD = cast_or_null<ValueDecl>(Importer.Import(E->getDecl()));
5362   if (!ToD)
5363     return nullptr;
5364
5365   NamedDecl *FoundD = nullptr;
5366   if (E->getDecl() != E->getFoundDecl()) {
5367     FoundD = cast_or_null<NamedDecl>(Importer.Import(E->getFoundDecl()));
5368     if (!FoundD)
5369       return nullptr;
5370   }
5371
5372   QualType T = Importer.Import(E->getType());
5373   if (T.isNull())
5374     return nullptr;
5375
5376   DeclRefExpr *DRE = DeclRefExpr::Create(Importer.getToContext(),
5377                                          Importer.Import(E->getQualifierLoc()),
5378                                    Importer.Import(E->getTemplateKeywordLoc()),
5379                                          ToD,
5380                                         E->refersToEnclosingVariableOrCapture(),
5381                                          Importer.Import(E->getLocation()),
5382                                          T, E->getValueKind(),
5383                                          FoundD,
5384                                          /*FIXME:TemplateArgs=*/nullptr);
5385   if (E->hadMultipleCandidates())
5386     DRE->setHadMultipleCandidates(true);
5387   return DRE;
5388 }
5389
5390 Expr *ASTNodeImporter::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
5391   QualType T = Importer.Import(E->getType());
5392   if (T.isNull())
5393     return NULL;
5394
5395   return new (Importer.getToContext()) ImplicitValueInitExpr(T);
5396 }
5397
5398 ASTNodeImporter::Designator
5399 ASTNodeImporter::ImportDesignator(const Designator &D) {
5400   if (D.isFieldDesignator()) {
5401     IdentifierInfo *ToFieldName = Importer.Import(D.getFieldName());
5402     // Caller checks for import error
5403     return Designator(ToFieldName, Importer.Import(D.getDotLoc()),
5404                       Importer.Import(D.getFieldLoc()));
5405   }
5406   if (D.isArrayDesignator())
5407     return Designator(D.getFirstExprIndex(),
5408                       Importer.Import(D.getLBracketLoc()),
5409                       Importer.Import(D.getRBracketLoc()));
5410
5411   assert(D.isArrayRangeDesignator());
5412   return Designator(D.getFirstExprIndex(),
5413                     Importer.Import(D.getLBracketLoc()),
5414                     Importer.Import(D.getEllipsisLoc()),
5415                     Importer.Import(D.getRBracketLoc()));
5416 }
5417
5418
5419 Expr *ASTNodeImporter::VisitDesignatedInitExpr(DesignatedInitExpr *DIE) {
5420   Expr *Init = cast_or_null<Expr>(Importer.Import(DIE->getInit()));
5421   if (!Init)
5422     return nullptr;
5423
5424   SmallVector<Expr *, 4> IndexExprs(DIE->getNumSubExprs() - 1);
5425   // List elements from the second, the first is Init itself
5426   for (unsigned I = 1, E = DIE->getNumSubExprs(); I < E; I++) {
5427     if (Expr *Arg = cast_or_null<Expr>(Importer.Import(DIE->getSubExpr(I))))
5428       IndexExprs[I - 1] = Arg;
5429     else
5430       return nullptr;
5431   }
5432
5433   SmallVector<Designator, 4> Designators(DIE->size());
5434   llvm::transform(DIE->designators(), Designators.begin(),
5435                   [this](const Designator &D) -> Designator {
5436                     return ImportDesignator(D);
5437                   });
5438
5439   for (const Designator &D : DIE->designators())
5440     if (D.isFieldDesignator() && !D.getFieldName())
5441       return nullptr;
5442
5443   return DesignatedInitExpr::Create(
5444         Importer.getToContext(), Designators,
5445         IndexExprs, Importer.Import(DIE->getEqualOrColonLoc()),
5446         DIE->usesGNUSyntax(), Init);
5447 }
5448
5449 Expr *ASTNodeImporter::VisitCXXNullPtrLiteralExpr(CXXNullPtrLiteralExpr *E) {
5450   QualType T = Importer.Import(E->getType());
5451   if (T.isNull())
5452     return nullptr;
5453
5454   return new (Importer.getToContext())
5455       CXXNullPtrLiteralExpr(T, Importer.Import(E->getLocation()));
5456 }
5457
5458 Expr *ASTNodeImporter::VisitIntegerLiteral(IntegerLiteral *E) {
5459   QualType T = Importer.Import(E->getType());
5460   if (T.isNull())
5461     return nullptr;
5462
5463   return IntegerLiteral::Create(Importer.getToContext(),
5464                                 E->getValue(), T,
5465                                 Importer.Import(E->getLocation()));
5466 }
5467
5468 Expr *ASTNodeImporter::VisitFloatingLiteral(FloatingLiteral *E) {
5469   QualType T = Importer.Import(E->getType());
5470   if (T.isNull())
5471     return nullptr;
5472
5473   return FloatingLiteral::Create(Importer.getToContext(),
5474                                 E->getValue(), E->isExact(), T,
5475                                 Importer.Import(E->getLocation()));
5476 }
5477
5478 Expr *ASTNodeImporter::VisitCharacterLiteral(CharacterLiteral *E) {
5479   QualType T = Importer.Import(E->getType());
5480   if (T.isNull())
5481     return nullptr;
5482
5483   return new (Importer.getToContext()) CharacterLiteral(E->getValue(),
5484                                                         E->getKind(), T,
5485                                           Importer.Import(E->getLocation()));
5486 }
5487
5488 Expr *ASTNodeImporter::VisitStringLiteral(StringLiteral *E) {
5489   QualType T = Importer.Import(E->getType());
5490   if (T.isNull())
5491     return nullptr;
5492
5493   SmallVector<SourceLocation, 4> Locations(E->getNumConcatenated());
5494   ImportArray(E->tokloc_begin(), E->tokloc_end(), Locations.begin());
5495
5496   return StringLiteral::Create(Importer.getToContext(), E->getBytes(),
5497                                E->getKind(), E->isPascal(), T,
5498                                Locations.data(), Locations.size());
5499 }
5500
5501 Expr *ASTNodeImporter::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
5502   QualType T = Importer.Import(E->getType());
5503   if (T.isNull())
5504     return nullptr;
5505
5506   TypeSourceInfo *TInfo = Importer.Import(E->getTypeSourceInfo());
5507   if (!TInfo)
5508     return nullptr;
5509
5510   Expr *Init = Importer.Import(E->getInitializer());
5511   if (!Init)
5512     return nullptr;
5513
5514   return new (Importer.getToContext()) CompoundLiteralExpr(
5515         Importer.Import(E->getLParenLoc()), TInfo, T, E->getValueKind(),
5516         Init, E->isFileScope());
5517 }
5518
5519 Expr *ASTNodeImporter::VisitAtomicExpr(AtomicExpr *E) {
5520   QualType T = Importer.Import(E->getType());
5521   if (T.isNull())
5522     return nullptr;
5523
5524   SmallVector<Expr *, 6> Exprs(E->getNumSubExprs());
5525   if (ImportArrayChecked(
5526         E->getSubExprs(), E->getSubExprs() + E->getNumSubExprs(),
5527         Exprs.begin()))
5528     return nullptr;
5529
5530   return new (Importer.getToContext()) AtomicExpr(
5531         Importer.Import(E->getBuiltinLoc()), Exprs, T, E->getOp(),
5532         Importer.Import(E->getRParenLoc()));
5533 }
5534
5535 Expr *ASTNodeImporter::VisitAddrLabelExpr(AddrLabelExpr *E) {
5536   QualType T = Importer.Import(E->getType());
5537   if (T.isNull())
5538     return nullptr;
5539
5540   LabelDecl *ToLabel = cast_or_null<LabelDecl>(Importer.Import(E->getLabel()));
5541   if (!ToLabel)
5542     return nullptr;
5543
5544   return new (Importer.getToContext()) AddrLabelExpr(
5545         Importer.Import(E->getAmpAmpLoc()), Importer.Import(E->getLabelLoc()),
5546         ToLabel, T);
5547 }
5548
5549 Expr *ASTNodeImporter::VisitParenExpr(ParenExpr *E) {
5550   Expr *SubExpr = Importer.Import(E->getSubExpr());
5551   if (!SubExpr)
5552     return nullptr;
5553
5554   return new (Importer.getToContext())
5555                                   ParenExpr(Importer.Import(E->getLParen()),
5556                                             Importer.Import(E->getRParen()),
5557                                             SubExpr);
5558 }
5559
5560 Expr *ASTNodeImporter::VisitParenListExpr(ParenListExpr *E) {
5561   SmallVector<Expr *, 4> Exprs(E->getNumExprs());
5562   if (ImportArrayChecked(
5563         E->getExprs(), E->getExprs() + E->getNumExprs(), Exprs.begin()))
5564     return nullptr;
5565
5566   return new (Importer.getToContext()) ParenListExpr(
5567         Importer.getToContext(), Importer.Import(E->getLParenLoc()),
5568         Exprs, Importer.Import(E->getLParenLoc()));
5569 }
5570
5571 Expr *ASTNodeImporter::VisitStmtExpr(StmtExpr *E) {
5572   QualType T = Importer.Import(E->getType());
5573   if (T.isNull())
5574     return nullptr;
5575
5576   CompoundStmt *ToSubStmt = cast_or_null<CompoundStmt>(
5577         Importer.Import(E->getSubStmt()));
5578   if (!ToSubStmt && E->getSubStmt())
5579     return nullptr;
5580
5581   return new (Importer.getToContext()) StmtExpr(ToSubStmt, T,
5582         Importer.Import(E->getLParenLoc()), Importer.Import(E->getRParenLoc()));
5583 }
5584
5585 Expr *ASTNodeImporter::VisitUnaryOperator(UnaryOperator *E) {
5586   QualType T = Importer.Import(E->getType());
5587   if (T.isNull())
5588     return nullptr;
5589
5590   Expr *SubExpr = Importer.Import(E->getSubExpr());
5591   if (!SubExpr)
5592     return nullptr;
5593
5594   return new (Importer.getToContext()) UnaryOperator(SubExpr, E->getOpcode(),
5595                                                      T, E->getValueKind(),
5596                                                      E->getObjectKind(),
5597                                          Importer.Import(E->getOperatorLoc()));
5598 }
5599
5600 Expr *ASTNodeImporter::VisitUnaryExprOrTypeTraitExpr(
5601                                             UnaryExprOrTypeTraitExpr *E) {
5602   QualType ResultType = Importer.Import(E->getType());
5603
5604   if (E->isArgumentType()) {
5605     TypeSourceInfo *TInfo = Importer.Import(E->getArgumentTypeInfo());
5606     if (!TInfo)
5607       return nullptr;
5608
5609     return new (Importer.getToContext()) UnaryExprOrTypeTraitExpr(E->getKind(),
5610                                            TInfo, ResultType,
5611                                            Importer.Import(E->getOperatorLoc()),
5612                                            Importer.Import(E->getRParenLoc()));
5613   }
5614
5615   Expr *SubExpr = Importer.Import(E->getArgumentExpr());
5616   if (!SubExpr)
5617     return nullptr;
5618
5619   return new (Importer.getToContext()) UnaryExprOrTypeTraitExpr(E->getKind(),
5620                                           SubExpr, ResultType,
5621                                           Importer.Import(E->getOperatorLoc()),
5622                                           Importer.Import(E->getRParenLoc()));
5623 }
5624
5625 Expr *ASTNodeImporter::VisitBinaryOperator(BinaryOperator *E) {
5626   QualType T = Importer.Import(E->getType());
5627   if (T.isNull())
5628     return nullptr;
5629
5630   Expr *LHS = Importer.Import(E->getLHS());
5631   if (!LHS)
5632     return nullptr;
5633
5634   Expr *RHS = Importer.Import(E->getRHS());
5635   if (!RHS)
5636     return nullptr;
5637
5638   return new (Importer.getToContext()) BinaryOperator(LHS, RHS, E->getOpcode(),
5639                                                       T, E->getValueKind(),
5640                                                       E->getObjectKind(),
5641                                            Importer.Import(E->getOperatorLoc()),
5642                                                       E->isFPContractable());
5643 }
5644
5645 Expr *ASTNodeImporter::VisitConditionalOperator(ConditionalOperator *E) {
5646   QualType T = Importer.Import(E->getType());
5647   if (T.isNull())
5648     return nullptr;
5649
5650   Expr *ToLHS = Importer.Import(E->getLHS());
5651   if (!ToLHS)
5652     return nullptr;
5653
5654   Expr *ToRHS = Importer.Import(E->getRHS());
5655   if (!ToRHS)
5656     return nullptr;
5657
5658   Expr *ToCond = Importer.Import(E->getCond());
5659   if (!ToCond)
5660     return nullptr;
5661
5662   return new (Importer.getToContext()) ConditionalOperator(
5663         ToCond, Importer.Import(E->getQuestionLoc()),
5664         ToLHS, Importer.Import(E->getColonLoc()),
5665         ToRHS, T, E->getValueKind(), E->getObjectKind());
5666 }
5667
5668 Expr *ASTNodeImporter::VisitBinaryConditionalOperator(
5669     BinaryConditionalOperator *E) {
5670   QualType T = Importer.Import(E->getType());
5671   if (T.isNull())
5672     return nullptr;
5673
5674   Expr *Common = Importer.Import(E->getCommon());
5675   if (!Common)
5676     return nullptr;
5677
5678   Expr *Cond = Importer.Import(E->getCond());
5679   if (!Cond)
5680     return nullptr;
5681
5682   OpaqueValueExpr *OpaqueValue = cast_or_null<OpaqueValueExpr>(
5683         Importer.Import(E->getOpaqueValue()));
5684   if (!OpaqueValue)
5685     return nullptr;
5686
5687   Expr *TrueExpr = Importer.Import(E->getTrueExpr());
5688   if (!TrueExpr)
5689     return nullptr;
5690
5691   Expr *FalseExpr = Importer.Import(E->getFalseExpr());
5692   if (!FalseExpr)
5693     return nullptr;
5694
5695   return new (Importer.getToContext()) BinaryConditionalOperator(
5696         Common, OpaqueValue, Cond, TrueExpr, FalseExpr,
5697         Importer.Import(E->getQuestionLoc()), Importer.Import(E->getColonLoc()),
5698         T, E->getValueKind(), E->getObjectKind());
5699 }
5700
5701 Expr *ASTNodeImporter::VisitOpaqueValueExpr(OpaqueValueExpr *E) {
5702   QualType T = Importer.Import(E->getType());
5703   if (T.isNull())
5704     return nullptr;
5705
5706   Expr *SourceExpr = Importer.Import(E->getSourceExpr());
5707   if (!SourceExpr && E->getSourceExpr())
5708     return nullptr;
5709
5710   return new (Importer.getToContext()) OpaqueValueExpr(
5711         Importer.Import(E->getExprLoc()), T, E->getValueKind(),
5712         E->getObjectKind(), SourceExpr);
5713 }
5714
5715 Expr *ASTNodeImporter::VisitCompoundAssignOperator(CompoundAssignOperator *E) {
5716   QualType T = Importer.Import(E->getType());
5717   if (T.isNull())
5718     return nullptr;
5719
5720   QualType CompLHSType = Importer.Import(E->getComputationLHSType());
5721   if (CompLHSType.isNull())
5722     return nullptr;
5723
5724   QualType CompResultType = Importer.Import(E->getComputationResultType());
5725   if (CompResultType.isNull())
5726     return nullptr;
5727
5728   Expr *LHS = Importer.Import(E->getLHS());
5729   if (!LHS)
5730     return nullptr;
5731
5732   Expr *RHS = Importer.Import(E->getRHS());
5733   if (!RHS)
5734     return nullptr;
5735
5736   return new (Importer.getToContext())
5737                         CompoundAssignOperator(LHS, RHS, E->getOpcode(),
5738                                                T, E->getValueKind(),
5739                                                E->getObjectKind(),
5740                                                CompLHSType, CompResultType,
5741                                            Importer.Import(E->getOperatorLoc()),
5742                                                E->isFPContractable());
5743 }
5744
5745 static bool ImportCastPath(CastExpr *E, CXXCastPath &Path) {
5746   if (E->path_empty()) return false;
5747
5748   // TODO: import cast paths
5749   return true;
5750 }
5751
5752 Expr *ASTNodeImporter::VisitImplicitCastExpr(ImplicitCastExpr *E) {
5753   QualType T = Importer.Import(E->getType());
5754   if (T.isNull())
5755     return nullptr;
5756
5757   Expr *SubExpr = Importer.Import(E->getSubExpr());
5758   if (!SubExpr)
5759     return nullptr;
5760
5761   CXXCastPath BasePath;
5762   if (ImportCastPath(E, BasePath))
5763     return nullptr;
5764
5765   return ImplicitCastExpr::Create(Importer.getToContext(), T, E->getCastKind(),
5766                                   SubExpr, &BasePath, E->getValueKind());
5767 }
5768
5769 Expr *ASTNodeImporter::VisitCStyleCastExpr(CStyleCastExpr *E) {
5770   QualType T = Importer.Import(E->getType());
5771   if (T.isNull())
5772     return nullptr;
5773
5774   Expr *SubExpr = Importer.Import(E->getSubExpr());
5775   if (!SubExpr)
5776     return nullptr;
5777
5778   TypeSourceInfo *TInfo = Importer.Import(E->getTypeInfoAsWritten());
5779   if (!TInfo && E->getTypeInfoAsWritten())
5780     return nullptr;
5781
5782   CXXCastPath BasePath;
5783   if (ImportCastPath(E, BasePath))
5784     return nullptr;
5785
5786   return CStyleCastExpr::Create(Importer.getToContext(), T,
5787                                 E->getValueKind(), E->getCastKind(),
5788                                 SubExpr, &BasePath, TInfo,
5789                                 Importer.Import(E->getLParenLoc()),
5790                                 Importer.Import(E->getRParenLoc()));
5791 }
5792
5793 Expr *ASTNodeImporter::VisitCXXConstructExpr(CXXConstructExpr *E) {
5794   QualType T = Importer.Import(E->getType());
5795   if (T.isNull())
5796     return nullptr;
5797
5798   CXXConstructorDecl *ToCCD =
5799     dyn_cast_or_null<CXXConstructorDecl>(Importer.Import(E->getConstructor()));
5800   if (!ToCCD)
5801     return nullptr;
5802
5803   SmallVector<Expr *, 6> ToArgs(E->getNumArgs());
5804   if (ImportArrayChecked(E->getArgs(), E->getArgs() + E->getNumArgs(),
5805                          ToArgs.begin()))
5806     return nullptr;
5807
5808   return CXXConstructExpr::Create(Importer.getToContext(), T,
5809                                   Importer.Import(E->getLocation()),
5810                                   ToCCD, E->isElidable(),
5811                                   ToArgs, E->hadMultipleCandidates(),
5812                                   E->isListInitialization(),
5813                                   E->isStdInitListInitialization(),
5814                                   E->requiresZeroInitialization(),
5815                                   E->getConstructionKind(),
5816                                   Importer.Import(E->getParenOrBraceRange()));
5817 }
5818
5819 Expr *ASTNodeImporter::VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
5820   QualType T = Importer.Import(E->getType());
5821   if (T.isNull())
5822     return nullptr;
5823
5824   Expr *ToFn = Importer.Import(E->getCallee());
5825   if (!ToFn)
5826     return nullptr;
5827
5828   SmallVector<Expr *, 4> ToArgs(E->getNumArgs());
5829
5830   if (ImportArrayChecked(E->arg_begin(), E->arg_end(), ToArgs.begin()))
5831     return nullptr;
5832
5833   return new (Importer.getToContext()) CXXMemberCallExpr(
5834         Importer.getToContext(), ToFn, ToArgs, T, E->getValueKind(),
5835         Importer.Import(E->getRParenLoc()));
5836 }
5837
5838 Expr *ASTNodeImporter::VisitCXXThisExpr(CXXThisExpr *E) {
5839   QualType T = Importer.Import(E->getType());
5840   if (T.isNull())
5841     return nullptr;
5842
5843   return new (Importer.getToContext())
5844   CXXThisExpr(Importer.Import(E->getLocation()), T, E->isImplicit());
5845 }
5846
5847 Expr *ASTNodeImporter::VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E) {
5848   QualType T = Importer.Import(E->getType());
5849   if (T.isNull())
5850     return nullptr;
5851
5852   return new (Importer.getToContext())
5853   CXXBoolLiteralExpr(E->getValue(), T, Importer.Import(E->getLocation()));
5854 }
5855
5856
5857 Expr *ASTNodeImporter::VisitMemberExpr(MemberExpr *E) {
5858   QualType T = Importer.Import(E->getType());
5859   if (T.isNull())
5860     return nullptr;
5861
5862   Expr *ToBase = Importer.Import(E->getBase());
5863   if (!ToBase && E->getBase())
5864     return nullptr;
5865
5866   ValueDecl *ToMember = dyn_cast<ValueDecl>(Importer.Import(E->getMemberDecl()));
5867   if (!ToMember && E->getMemberDecl())
5868     return nullptr;
5869
5870   DeclAccessPair ToFoundDecl = DeclAccessPair::make(
5871     dyn_cast<NamedDecl>(Importer.Import(E->getFoundDecl().getDecl())),
5872     E->getFoundDecl().getAccess());
5873
5874   DeclarationNameInfo ToMemberNameInfo(
5875     Importer.Import(E->getMemberNameInfo().getName()),
5876     Importer.Import(E->getMemberNameInfo().getLoc()));
5877
5878   if (E->hasExplicitTemplateArgs()) {
5879     return nullptr; // FIXME: handle template arguments
5880   }
5881
5882   return MemberExpr::Create(Importer.getToContext(), ToBase,
5883                             E->isArrow(),
5884                             Importer.Import(E->getOperatorLoc()),
5885                             Importer.Import(E->getQualifierLoc()),
5886                             Importer.Import(E->getTemplateKeywordLoc()),
5887                             ToMember, ToFoundDecl, ToMemberNameInfo,
5888                             nullptr, T, E->getValueKind(),
5889                             E->getObjectKind());
5890 }
5891
5892 Expr *ASTNodeImporter::VisitCallExpr(CallExpr *E) {
5893   QualType T = Importer.Import(E->getType());
5894   if (T.isNull())
5895     return nullptr;
5896
5897   Expr *ToCallee = Importer.Import(E->getCallee());
5898   if (!ToCallee && E->getCallee())
5899     return nullptr;
5900
5901   unsigned NumArgs = E->getNumArgs();
5902
5903   llvm::SmallVector<Expr *, 2> ToArgs(NumArgs);
5904
5905   for (unsigned ai = 0, ae = NumArgs; ai != ae; ++ai) {
5906     Expr *FromArg = E->getArg(ai);
5907     Expr *ToArg = Importer.Import(FromArg);
5908     if (!ToArg)
5909       return nullptr;
5910     ToArgs[ai] = ToArg;
5911   }
5912
5913   Expr **ToArgs_Copied = new (Importer.getToContext())
5914     Expr*[NumArgs];
5915
5916   for (unsigned ai = 0, ae = NumArgs; ai != ae; ++ai)
5917     ToArgs_Copied[ai] = ToArgs[ai];
5918
5919   return new (Importer.getToContext())
5920     CallExpr(Importer.getToContext(), ToCallee,
5921              llvm::makeArrayRef(ToArgs_Copied, NumArgs), T, E->getValueKind(),
5922              Importer.Import(E->getRParenLoc()));
5923 }
5924
5925 Expr *ASTNodeImporter::VisitInitListExpr(InitListExpr *ILE) {
5926   QualType T = Importer.Import(ILE->getType());
5927   if (T.isNull())
5928     return nullptr;
5929
5930   llvm::SmallVector<Expr *, 4> Exprs(ILE->getNumInits());
5931   if (ImportArrayChecked(
5932         ILE->getInits(), ILE->getInits() + ILE->getNumInits(), Exprs.begin()))
5933     return nullptr;
5934
5935   ASTContext &ToCtx = Importer.getToContext();
5936   InitListExpr *To = new (ToCtx) InitListExpr(
5937         ToCtx, Importer.Import(ILE->getLBraceLoc()),
5938         Exprs, Importer.Import(ILE->getLBraceLoc()));
5939   To->setType(T);
5940
5941   if (ILE->hasArrayFiller()) {
5942     Expr *Filler = Importer.Import(ILE->getArrayFiller());
5943     if (!Filler)
5944       return nullptr;
5945     To->setArrayFiller(Filler);
5946   }
5947
5948   if (FieldDecl *FromFD = ILE->getInitializedFieldInUnion()) {
5949     FieldDecl *ToFD = cast_or_null<FieldDecl>(Importer.Import(FromFD));
5950     if (!ToFD)
5951       return nullptr;
5952     To->setInitializedFieldInUnion(ToFD);
5953   }
5954
5955   if (InitListExpr *SyntForm = ILE->getSyntacticForm()) {
5956     InitListExpr *ToSyntForm = cast_or_null<InitListExpr>(
5957           Importer.Import(SyntForm));
5958     if (!ToSyntForm)
5959       return nullptr;
5960     To->setSyntacticForm(ToSyntForm);
5961   }
5962
5963   To->sawArrayRangeDesignator(ILE->hadArrayRangeDesignator());
5964   To->setValueDependent(ILE->isValueDependent());
5965   To->setInstantiationDependent(ILE->isInstantiationDependent());
5966
5967   return To;
5968 }
5969
5970 Expr *ASTNodeImporter::VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
5971   FieldDecl *ToField = llvm::dyn_cast_or_null<FieldDecl>(
5972       Importer.Import(DIE->getField()));
5973   if (!ToField && DIE->getField())
5974     return nullptr;
5975
5976   return CXXDefaultInitExpr::Create(
5977       Importer.getToContext(), Importer.Import(DIE->getLocStart()), ToField);
5978 }
5979
5980 Expr *ASTNodeImporter::VisitCXXNamedCastExpr(CXXNamedCastExpr *E) {
5981   QualType ToType = Importer.Import(E->getType());
5982   if (ToType.isNull() && !E->getType().isNull())
5983     return nullptr;
5984   ExprValueKind VK = E->getValueKind();
5985   CastKind CK = E->getCastKind();
5986   Expr *ToOp = Importer.Import(E->getSubExpr());
5987   if (!ToOp && E->getSubExpr())
5988     return nullptr;
5989   CXXCastPath BasePath;
5990   if (ImportCastPath(E, BasePath))
5991     return nullptr;
5992   TypeSourceInfo *ToWritten = Importer.Import(E->getTypeInfoAsWritten());
5993   SourceLocation ToOperatorLoc = Importer.Import(E->getOperatorLoc());
5994   SourceLocation ToRParenLoc = Importer.Import(E->getRParenLoc());
5995   SourceRange ToAngleBrackets = Importer.Import(E->getAngleBrackets());
5996
5997   if (isa<CXXStaticCastExpr>(E)) {
5998     return CXXStaticCastExpr::Create(
5999         Importer.getToContext(), ToType, VK, CK, ToOp, &BasePath,
6000         ToWritten, ToOperatorLoc, ToRParenLoc, ToAngleBrackets);
6001   } else if (isa<CXXDynamicCastExpr>(E)) {
6002     return CXXDynamicCastExpr::Create(
6003         Importer.getToContext(), ToType, VK, CK, ToOp, &BasePath,
6004         ToWritten, ToOperatorLoc, ToRParenLoc, ToAngleBrackets);
6005   } else if (isa<CXXReinterpretCastExpr>(E)) {
6006     return CXXReinterpretCastExpr::Create(
6007         Importer.getToContext(), ToType, VK, CK, ToOp, &BasePath,
6008         ToWritten, ToOperatorLoc, ToRParenLoc, ToAngleBrackets);
6009   } else {
6010     return nullptr;
6011   }
6012 }
6013
6014 ASTImporter::ASTImporter(ASTContext &ToContext, FileManager &ToFileManager,
6015                          ASTContext &FromContext, FileManager &FromFileManager,
6016                          bool MinimalImport)
6017   : ToContext(ToContext), FromContext(FromContext),
6018     ToFileManager(ToFileManager), FromFileManager(FromFileManager),
6019     Minimal(MinimalImport), LastDiagFromFrom(false)
6020 {
6021   ImportedDecls[FromContext.getTranslationUnitDecl()]
6022     = ToContext.getTranslationUnitDecl();
6023 }
6024
6025 ASTImporter::~ASTImporter() { }
6026
6027 QualType ASTImporter::Import(QualType FromT) {
6028   if (FromT.isNull())
6029     return QualType();
6030
6031   const Type *fromTy = FromT.getTypePtr();
6032
6033   // Check whether we've already imported this type.
6034   llvm::DenseMap<const Type *, const Type *>::iterator Pos
6035     = ImportedTypes.find(fromTy);
6036   if (Pos != ImportedTypes.end())
6037     return ToContext.getQualifiedType(Pos->second, FromT.getLocalQualifiers());
6038
6039   // Import the type
6040   ASTNodeImporter Importer(*this);
6041   QualType ToT = Importer.Visit(fromTy);
6042   if (ToT.isNull())
6043     return ToT;
6044
6045   // Record the imported type.
6046   ImportedTypes[fromTy] = ToT.getTypePtr();
6047
6048   return ToContext.getQualifiedType(ToT, FromT.getLocalQualifiers());
6049 }
6050
6051 TypeSourceInfo *ASTImporter::Import(TypeSourceInfo *FromTSI) {
6052   if (!FromTSI)
6053     return FromTSI;
6054
6055   // FIXME: For now we just create a "trivial" type source info based
6056   // on the type and a single location. Implement a real version of this.
6057   QualType T = Import(FromTSI->getType());
6058   if (T.isNull())
6059     return nullptr;
6060
6061   return ToContext.getTrivialTypeSourceInfo(T,
6062            Import(FromTSI->getTypeLoc().getLocStart()));
6063 }
6064
6065 Decl *ASTImporter::GetAlreadyImportedOrNull(Decl *FromD) {
6066   llvm::DenseMap<Decl *, Decl *>::iterator Pos = ImportedDecls.find(FromD);
6067   if (Pos != ImportedDecls.end()) {
6068     Decl *ToD = Pos->second;
6069     ASTNodeImporter(*this).ImportDefinitionIfNeeded(FromD, ToD);
6070     return ToD;
6071   } else {
6072     return nullptr;
6073   }
6074 }
6075
6076 Decl *ASTImporter::Import(Decl *FromD) {
6077   if (!FromD)
6078     return nullptr;
6079
6080   ASTNodeImporter Importer(*this);
6081
6082   // Check whether we've already imported this declaration.
6083   llvm::DenseMap<Decl *, Decl *>::iterator Pos = ImportedDecls.find(FromD);
6084   if (Pos != ImportedDecls.end()) {
6085     Decl *ToD = Pos->second;
6086     Importer.ImportDefinitionIfNeeded(FromD, ToD);
6087     return ToD;
6088   }
6089
6090   // Import the type
6091   Decl *ToD = Importer.Visit(FromD);
6092   if (!ToD)
6093     return nullptr;
6094
6095   // Record the imported declaration.
6096   ImportedDecls[FromD] = ToD;
6097
6098   if (TagDecl *FromTag = dyn_cast<TagDecl>(FromD)) {
6099     // Keep track of anonymous tags that have an associated typedef.
6100     if (FromTag->getTypedefNameForAnonDecl())
6101       AnonTagsWithPendingTypedefs.push_back(FromTag);
6102   } else if (TypedefNameDecl *FromTypedef = dyn_cast<TypedefNameDecl>(FromD)) {
6103     // When we've finished transforming a typedef, see whether it was the
6104     // typedef for an anonymous tag.
6105     for (SmallVectorImpl<TagDecl *>::iterator
6106                FromTag = AnonTagsWithPendingTypedefs.begin(),
6107             FromTagEnd = AnonTagsWithPendingTypedefs.end();
6108          FromTag != FromTagEnd; ++FromTag) {
6109       if ((*FromTag)->getTypedefNameForAnonDecl() == FromTypedef) {
6110         if (TagDecl *ToTag = cast_or_null<TagDecl>(Import(*FromTag))) {
6111           // We found the typedef for an anonymous tag; link them.
6112           ToTag->setTypedefNameForAnonDecl(cast<TypedefNameDecl>(ToD));
6113           AnonTagsWithPendingTypedefs.erase(FromTag);
6114           break;
6115         }
6116       }
6117     }
6118   }
6119
6120   return ToD;
6121 }
6122
6123 DeclContext *ASTImporter::ImportContext(DeclContext *FromDC) {
6124   if (!FromDC)
6125     return FromDC;
6126
6127   DeclContext *ToDC = cast_or_null<DeclContext>(Import(cast<Decl>(FromDC)));
6128   if (!ToDC)
6129     return nullptr;
6130
6131   // When we're using a record/enum/Objective-C class/protocol as a context, we
6132   // need it to have a definition.
6133   if (RecordDecl *ToRecord = dyn_cast<RecordDecl>(ToDC)) {
6134     RecordDecl *FromRecord = cast<RecordDecl>(FromDC);
6135     if (ToRecord->isCompleteDefinition()) {
6136       // Do nothing.
6137     } else if (FromRecord->isCompleteDefinition()) {
6138       ASTNodeImporter(*this).ImportDefinition(FromRecord, ToRecord,
6139                                               ASTNodeImporter::IDK_Basic);
6140     } else {
6141       CompleteDecl(ToRecord);
6142     }
6143   } else if (EnumDecl *ToEnum = dyn_cast<EnumDecl>(ToDC)) {
6144     EnumDecl *FromEnum = cast<EnumDecl>(FromDC);
6145     if (ToEnum->isCompleteDefinition()) {
6146       // Do nothing.
6147     } else if (FromEnum->isCompleteDefinition()) {
6148       ASTNodeImporter(*this).ImportDefinition(FromEnum, ToEnum,
6149                                               ASTNodeImporter::IDK_Basic);
6150     } else {
6151       CompleteDecl(ToEnum);
6152     }
6153   } else if (ObjCInterfaceDecl *ToClass = dyn_cast<ObjCInterfaceDecl>(ToDC)) {
6154     ObjCInterfaceDecl *FromClass = cast<ObjCInterfaceDecl>(FromDC);
6155     if (ToClass->getDefinition()) {
6156       // Do nothing.
6157     } else if (ObjCInterfaceDecl *FromDef = FromClass->getDefinition()) {
6158       ASTNodeImporter(*this).ImportDefinition(FromDef, ToClass,
6159                                               ASTNodeImporter::IDK_Basic);
6160     } else {
6161       CompleteDecl(ToClass);
6162     }
6163   } else if (ObjCProtocolDecl *ToProto = dyn_cast<ObjCProtocolDecl>(ToDC)) {
6164     ObjCProtocolDecl *FromProto = cast<ObjCProtocolDecl>(FromDC);
6165     if (ToProto->getDefinition()) {
6166       // Do nothing.
6167     } else if (ObjCProtocolDecl *FromDef = FromProto->getDefinition()) {
6168       ASTNodeImporter(*this).ImportDefinition(FromDef, ToProto,
6169                                               ASTNodeImporter::IDK_Basic);
6170     } else {
6171       CompleteDecl(ToProto);
6172     }
6173   }
6174
6175   return ToDC;
6176 }
6177
6178 Expr *ASTImporter::Import(Expr *FromE) {
6179   if (!FromE)
6180     return nullptr;
6181
6182   return cast_or_null<Expr>(Import(cast<Stmt>(FromE)));
6183 }
6184
6185 Stmt *ASTImporter::Import(Stmt *FromS) {
6186   if (!FromS)
6187     return nullptr;
6188
6189   // Check whether we've already imported this declaration.
6190   llvm::DenseMap<Stmt *, Stmt *>::iterator Pos = ImportedStmts.find(FromS);
6191   if (Pos != ImportedStmts.end())
6192     return Pos->second;
6193
6194   // Import the type
6195   ASTNodeImporter Importer(*this);
6196   Stmt *ToS = Importer.Visit(FromS);
6197   if (!ToS)
6198     return nullptr;
6199
6200   // Record the imported declaration.
6201   ImportedStmts[FromS] = ToS;
6202   return ToS;
6203 }
6204
6205 NestedNameSpecifier *ASTImporter::Import(NestedNameSpecifier *FromNNS) {
6206   if (!FromNNS)
6207     return nullptr;
6208
6209   NestedNameSpecifier *prefix = Import(FromNNS->getPrefix());
6210
6211   switch (FromNNS->getKind()) {
6212   case NestedNameSpecifier::Identifier:
6213     if (IdentifierInfo *II = Import(FromNNS->getAsIdentifier())) {
6214       return NestedNameSpecifier::Create(ToContext, prefix, II);
6215     }
6216     return nullptr;
6217
6218   case NestedNameSpecifier::Namespace:
6219     if (NamespaceDecl *NS =
6220           cast<NamespaceDecl>(Import(FromNNS->getAsNamespace()))) {
6221       return NestedNameSpecifier::Create(ToContext, prefix, NS);
6222     }
6223     return nullptr;
6224
6225   case NestedNameSpecifier::NamespaceAlias:
6226     if (NamespaceAliasDecl *NSAD =
6227           cast<NamespaceAliasDecl>(Import(FromNNS->getAsNamespaceAlias()))) {
6228       return NestedNameSpecifier::Create(ToContext, prefix, NSAD);
6229     }
6230     return nullptr;
6231
6232   case NestedNameSpecifier::Global:
6233     return NestedNameSpecifier::GlobalSpecifier(ToContext);
6234
6235   case NestedNameSpecifier::Super:
6236     if (CXXRecordDecl *RD =
6237             cast<CXXRecordDecl>(Import(FromNNS->getAsRecordDecl()))) {
6238       return NestedNameSpecifier::SuperSpecifier(ToContext, RD);
6239     }
6240     return nullptr;
6241
6242   case NestedNameSpecifier::TypeSpec:
6243   case NestedNameSpecifier::TypeSpecWithTemplate: {
6244       QualType T = Import(QualType(FromNNS->getAsType(), 0u));
6245       if (!T.isNull()) {
6246         bool bTemplate = FromNNS->getKind() ==
6247                          NestedNameSpecifier::TypeSpecWithTemplate;
6248         return NestedNameSpecifier::Create(ToContext, prefix,
6249                                            bTemplate, T.getTypePtr());
6250       }
6251     }
6252       return nullptr;
6253   }
6254
6255   llvm_unreachable("Invalid nested name specifier kind");
6256 }
6257
6258 NestedNameSpecifierLoc ASTImporter::Import(NestedNameSpecifierLoc FromNNS) {
6259   // FIXME: Implement!
6260   return NestedNameSpecifierLoc();
6261 }
6262
6263 TemplateName ASTImporter::Import(TemplateName From) {
6264   switch (From.getKind()) {
6265   case TemplateName::Template:
6266     if (TemplateDecl *ToTemplate
6267                 = cast_or_null<TemplateDecl>(Import(From.getAsTemplateDecl())))
6268       return TemplateName(ToTemplate);
6269
6270     return TemplateName();
6271
6272   case TemplateName::OverloadedTemplate: {
6273     OverloadedTemplateStorage *FromStorage = From.getAsOverloadedTemplate();
6274     UnresolvedSet<2> ToTemplates;
6275     for (OverloadedTemplateStorage::iterator I = FromStorage->begin(),
6276                                              E = FromStorage->end();
6277          I != E; ++I) {
6278       if (NamedDecl *To = cast_or_null<NamedDecl>(Import(*I)))
6279         ToTemplates.addDecl(To);
6280       else
6281         return TemplateName();
6282     }
6283     return ToContext.getOverloadedTemplateName(ToTemplates.begin(),
6284                                                ToTemplates.end());
6285   }
6286
6287   case TemplateName::QualifiedTemplate: {
6288     QualifiedTemplateName *QTN = From.getAsQualifiedTemplateName();
6289     NestedNameSpecifier *Qualifier = Import(QTN->getQualifier());
6290     if (!Qualifier)
6291       return TemplateName();
6292
6293     if (TemplateDecl *ToTemplate
6294         = cast_or_null<TemplateDecl>(Import(From.getAsTemplateDecl())))
6295       return ToContext.getQualifiedTemplateName(Qualifier,
6296                                                 QTN->hasTemplateKeyword(),
6297                                                 ToTemplate);
6298
6299     return TemplateName();
6300   }
6301
6302   case TemplateName::DependentTemplate: {
6303     DependentTemplateName *DTN = From.getAsDependentTemplateName();
6304     NestedNameSpecifier *Qualifier = Import(DTN->getQualifier());
6305     if (!Qualifier)
6306       return TemplateName();
6307
6308     if (DTN->isIdentifier()) {
6309       return ToContext.getDependentTemplateName(Qualifier,
6310                                                 Import(DTN->getIdentifier()));
6311     }
6312
6313     return ToContext.getDependentTemplateName(Qualifier, DTN->getOperator());
6314   }
6315
6316   case TemplateName::SubstTemplateTemplateParm: {
6317     SubstTemplateTemplateParmStorage *subst
6318       = From.getAsSubstTemplateTemplateParm();
6319     TemplateTemplateParmDecl *param
6320       = cast_or_null<TemplateTemplateParmDecl>(Import(subst->getParameter()));
6321     if (!param)
6322       return TemplateName();
6323
6324     TemplateName replacement = Import(subst->getReplacement());
6325     if (replacement.isNull()) return TemplateName();
6326
6327     return ToContext.getSubstTemplateTemplateParm(param, replacement);
6328   }
6329
6330   case TemplateName::SubstTemplateTemplateParmPack: {
6331     SubstTemplateTemplateParmPackStorage *SubstPack
6332       = From.getAsSubstTemplateTemplateParmPack();
6333     TemplateTemplateParmDecl *Param
6334       = cast_or_null<TemplateTemplateParmDecl>(
6335                                         Import(SubstPack->getParameterPack()));
6336     if (!Param)
6337       return TemplateName();
6338
6339     ASTNodeImporter Importer(*this);
6340     TemplateArgument ArgPack
6341       = Importer.ImportTemplateArgument(SubstPack->getArgumentPack());
6342     if (ArgPack.isNull())
6343       return TemplateName();
6344
6345     return ToContext.getSubstTemplateTemplateParmPack(Param, ArgPack);
6346   }
6347   }
6348
6349   llvm_unreachable("Invalid template name kind");
6350 }
6351
6352 SourceLocation ASTImporter::Import(SourceLocation FromLoc) {
6353   if (FromLoc.isInvalid())
6354     return SourceLocation();
6355
6356   SourceManager &FromSM = FromContext.getSourceManager();
6357
6358   // For now, map everything down to its spelling location, so that we
6359   // don't have to import macro expansions.
6360   // FIXME: Import macro expansions!
6361   FromLoc = FromSM.getSpellingLoc(FromLoc);
6362   std::pair<FileID, unsigned> Decomposed = FromSM.getDecomposedLoc(FromLoc);
6363   SourceManager &ToSM = ToContext.getSourceManager();
6364   FileID ToFileID = Import(Decomposed.first);
6365   if (ToFileID.isInvalid())
6366     return SourceLocation();
6367   SourceLocation ret = ToSM.getLocForStartOfFile(ToFileID)
6368                            .getLocWithOffset(Decomposed.second);
6369   return ret;
6370 }
6371
6372 SourceRange ASTImporter::Import(SourceRange FromRange) {
6373   return SourceRange(Import(FromRange.getBegin()), Import(FromRange.getEnd()));
6374 }
6375
6376 FileID ASTImporter::Import(FileID FromID) {
6377   llvm::DenseMap<FileID, FileID>::iterator Pos
6378     = ImportedFileIDs.find(FromID);
6379   if (Pos != ImportedFileIDs.end())
6380     return Pos->second;
6381
6382   SourceManager &FromSM = FromContext.getSourceManager();
6383   SourceManager &ToSM = ToContext.getSourceManager();
6384   const SrcMgr::SLocEntry &FromSLoc = FromSM.getSLocEntry(FromID);
6385   assert(FromSLoc.isFile() && "Cannot handle macro expansions yet");
6386
6387   // Include location of this file.
6388   SourceLocation ToIncludeLoc = Import(FromSLoc.getFile().getIncludeLoc());
6389
6390   // Map the FileID for to the "to" source manager.
6391   FileID ToID;
6392   const SrcMgr::ContentCache *Cache = FromSLoc.getFile().getContentCache();
6393   if (Cache->OrigEntry && Cache->OrigEntry->getDir()) {
6394     // FIXME: We probably want to use getVirtualFile(), so we don't hit the
6395     // disk again
6396     // FIXME: We definitely want to re-use the existing MemoryBuffer, rather
6397     // than mmap the files several times.
6398     const FileEntry *Entry = ToFileManager.getFile(Cache->OrigEntry->getName());
6399     if (!Entry)
6400       return FileID();
6401     ToID = ToSM.createFileID(Entry, ToIncludeLoc,
6402                              FromSLoc.getFile().getFileCharacteristic());
6403   } else {
6404     // FIXME: We want to re-use the existing MemoryBuffer!
6405     const llvm::MemoryBuffer *
6406         FromBuf = Cache->getBuffer(FromContext.getDiagnostics(), FromSM);
6407     std::unique_ptr<llvm::MemoryBuffer> ToBuf
6408       = llvm::MemoryBuffer::getMemBufferCopy(FromBuf->getBuffer(),
6409                                              FromBuf->getBufferIdentifier());
6410     ToID = ToSM.createFileID(std::move(ToBuf),
6411                              FromSLoc.getFile().getFileCharacteristic());
6412   }
6413
6414
6415   ImportedFileIDs[FromID] = ToID;
6416   return ToID;
6417 }
6418
6419 CXXCtorInitializer *ASTImporter::Import(CXXCtorInitializer *From) {
6420   Expr *ToExpr = Import(From->getInit());
6421   if (!ToExpr && From->getInit())
6422     return nullptr;
6423
6424   if (From->isBaseInitializer()) {
6425     TypeSourceInfo *ToTInfo = Import(From->getTypeSourceInfo());
6426     if (!ToTInfo && From->getTypeSourceInfo())
6427       return nullptr;
6428
6429     return new (ToContext) CXXCtorInitializer(
6430         ToContext, ToTInfo, From->isBaseVirtual(), Import(From->getLParenLoc()),
6431         ToExpr, Import(From->getRParenLoc()),
6432         From->isPackExpansion() ? Import(From->getEllipsisLoc())
6433                                 : SourceLocation());
6434   } else if (From->isMemberInitializer()) {
6435     FieldDecl *ToField =
6436         llvm::cast_or_null<FieldDecl>(Import(From->getMember()));
6437     if (!ToField && From->getMember())
6438       return nullptr;
6439
6440     return new (ToContext) CXXCtorInitializer(
6441         ToContext, ToField, Import(From->getMemberLocation()),
6442         Import(From->getLParenLoc()), ToExpr, Import(From->getRParenLoc()));
6443   } else if (From->isIndirectMemberInitializer()) {
6444     IndirectFieldDecl *ToIField = llvm::cast_or_null<IndirectFieldDecl>(
6445         Import(From->getIndirectMember()));
6446     if (!ToIField && From->getIndirectMember())
6447       return nullptr;
6448
6449     return new (ToContext) CXXCtorInitializer(
6450         ToContext, ToIField, Import(From->getMemberLocation()),
6451         Import(From->getLParenLoc()), ToExpr, Import(From->getRParenLoc()));
6452   } else if (From->isDelegatingInitializer()) {
6453     TypeSourceInfo *ToTInfo = Import(From->getTypeSourceInfo());
6454     if (!ToTInfo && From->getTypeSourceInfo())
6455       return nullptr;
6456
6457     return new (ToContext)
6458         CXXCtorInitializer(ToContext, ToTInfo, Import(From->getLParenLoc()),
6459                            ToExpr, Import(From->getRParenLoc()));
6460   } else if (unsigned NumArrayIndices = From->getNumArrayIndices()) {
6461     FieldDecl *ToField =
6462         llvm::cast_or_null<FieldDecl>(Import(From->getMember()));
6463     if (!ToField && From->getMember())
6464       return nullptr;
6465
6466     SmallVector<VarDecl *, 4> ToAIs(NumArrayIndices);
6467
6468     for (unsigned AII = 0; AII < NumArrayIndices; ++AII) {
6469       VarDecl *ToArrayIndex =
6470           dyn_cast_or_null<VarDecl>(Import(From->getArrayIndex(AII)));
6471       if (!ToArrayIndex && From->getArrayIndex(AII))
6472         return nullptr;
6473     }
6474
6475     return CXXCtorInitializer::Create(
6476         ToContext, ToField, Import(From->getMemberLocation()),
6477         Import(From->getLParenLoc()), ToExpr, Import(From->getRParenLoc()),
6478         ToAIs.data(), NumArrayIndices);
6479   } else {
6480     return nullptr;
6481   }
6482 }
6483
6484
6485 void ASTImporter::ImportDefinition(Decl *From) {
6486   Decl *To = Import(From);
6487   if (!To)
6488     return;
6489
6490   if (DeclContext *FromDC = cast<DeclContext>(From)) {
6491     ASTNodeImporter Importer(*this);
6492
6493     if (RecordDecl *ToRecord = dyn_cast<RecordDecl>(To)) {
6494       if (!ToRecord->getDefinition()) {
6495         Importer.ImportDefinition(cast<RecordDecl>(FromDC), ToRecord,
6496                                   ASTNodeImporter::IDK_Everything);
6497         return;
6498       }
6499     }
6500
6501     if (EnumDecl *ToEnum = dyn_cast<EnumDecl>(To)) {
6502       if (!ToEnum->getDefinition()) {
6503         Importer.ImportDefinition(cast<EnumDecl>(FromDC), ToEnum,
6504                                   ASTNodeImporter::IDK_Everything);
6505         return;
6506       }
6507     }
6508
6509     if (ObjCInterfaceDecl *ToIFace = dyn_cast<ObjCInterfaceDecl>(To)) {
6510       if (!ToIFace->getDefinition()) {
6511         Importer.ImportDefinition(cast<ObjCInterfaceDecl>(FromDC), ToIFace,
6512                                   ASTNodeImporter::IDK_Everything);
6513         return;
6514       }
6515     }
6516
6517     if (ObjCProtocolDecl *ToProto = dyn_cast<ObjCProtocolDecl>(To)) {
6518       if (!ToProto->getDefinition()) {
6519         Importer.ImportDefinition(cast<ObjCProtocolDecl>(FromDC), ToProto,
6520                                   ASTNodeImporter::IDK_Everything);
6521         return;
6522       }
6523     }
6524
6525     Importer.ImportDeclContext(FromDC, true);
6526   }
6527 }
6528
6529 DeclarationName ASTImporter::Import(DeclarationName FromName) {
6530   if (!FromName)
6531     return DeclarationName();
6532
6533   switch (FromName.getNameKind()) {
6534   case DeclarationName::Identifier:
6535     return Import(FromName.getAsIdentifierInfo());
6536
6537   case DeclarationName::ObjCZeroArgSelector:
6538   case DeclarationName::ObjCOneArgSelector:
6539   case DeclarationName::ObjCMultiArgSelector:
6540     return Import(FromName.getObjCSelector());
6541
6542   case DeclarationName::CXXConstructorName: {
6543     QualType T = Import(FromName.getCXXNameType());
6544     if (T.isNull())
6545       return DeclarationName();
6546
6547     return ToContext.DeclarationNames.getCXXConstructorName(
6548                                                ToContext.getCanonicalType(T));
6549   }
6550
6551   case DeclarationName::CXXDestructorName: {
6552     QualType T = Import(FromName.getCXXNameType());
6553     if (T.isNull())
6554       return DeclarationName();
6555
6556     return ToContext.DeclarationNames.getCXXDestructorName(
6557                                                ToContext.getCanonicalType(T));
6558   }
6559
6560   case DeclarationName::CXXConversionFunctionName: {
6561     QualType T = Import(FromName.getCXXNameType());
6562     if (T.isNull())
6563       return DeclarationName();
6564
6565     return ToContext.DeclarationNames.getCXXConversionFunctionName(
6566                                                ToContext.getCanonicalType(T));
6567   }
6568
6569   case DeclarationName::CXXOperatorName:
6570     return ToContext.DeclarationNames.getCXXOperatorName(
6571                                           FromName.getCXXOverloadedOperator());
6572
6573   case DeclarationName::CXXLiteralOperatorName:
6574     return ToContext.DeclarationNames.getCXXLiteralOperatorName(
6575                                    Import(FromName.getCXXLiteralIdentifier()));
6576
6577   case DeclarationName::CXXUsingDirective:
6578     // FIXME: STATICS!
6579     return DeclarationName::getUsingDirectiveName();
6580   }
6581
6582   llvm_unreachable("Invalid DeclarationName Kind!");
6583 }
6584
6585 IdentifierInfo *ASTImporter::Import(const IdentifierInfo *FromId) {
6586   if (!FromId)
6587     return nullptr;
6588
6589   IdentifierInfo *ToId = &ToContext.Idents.get(FromId->getName());
6590
6591   if (!ToId->getBuiltinID() && FromId->getBuiltinID())
6592     ToId->setBuiltinID(FromId->getBuiltinID());
6593
6594   return ToId;
6595 }
6596
6597 Selector ASTImporter::Import(Selector FromSel) {
6598   if (FromSel.isNull())
6599     return Selector();
6600
6601   SmallVector<IdentifierInfo *, 4> Idents;
6602   Idents.push_back(Import(FromSel.getIdentifierInfoForSlot(0)));
6603   for (unsigned I = 1, N = FromSel.getNumArgs(); I < N; ++I)
6604     Idents.push_back(Import(FromSel.getIdentifierInfoForSlot(I)));
6605   return ToContext.Selectors.getSelector(FromSel.getNumArgs(), Idents.data());
6606 }
6607
6608 DeclarationName ASTImporter::HandleNameConflict(DeclarationName Name,
6609                                                 DeclContext *DC,
6610                                                 unsigned IDNS,
6611                                                 NamedDecl **Decls,
6612                                                 unsigned NumDecls) {
6613   return Name;
6614 }
6615
6616 DiagnosticBuilder ASTImporter::ToDiag(SourceLocation Loc, unsigned DiagID) {
6617   if (LastDiagFromFrom)
6618     ToContext.getDiagnostics().notePriorDiagnosticFrom(
6619       FromContext.getDiagnostics());
6620   LastDiagFromFrom = false;
6621   return ToContext.getDiagnostics().Report(Loc, DiagID);
6622 }
6623
6624 DiagnosticBuilder ASTImporter::FromDiag(SourceLocation Loc, unsigned DiagID) {
6625   if (!LastDiagFromFrom)
6626     FromContext.getDiagnostics().notePriorDiagnosticFrom(
6627       ToContext.getDiagnostics());
6628   LastDiagFromFrom = true;
6629   return FromContext.getDiagnostics().Report(Loc, DiagID);
6630 }
6631
6632 void ASTImporter::CompleteDecl (Decl *D) {
6633   if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D)) {
6634     if (!ID->getDefinition())
6635       ID->startDefinition();
6636   }
6637   else if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D)) {
6638     if (!PD->getDefinition())
6639       PD->startDefinition();
6640   }
6641   else if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
6642     if (!TD->getDefinition() && !TD->isBeingDefined()) {
6643       TD->startDefinition();
6644       TD->setCompleteDefinition(true);
6645     }
6646   }
6647   else {
6648     assert (0 && "CompleteDecl called on a Decl that can't be completed");
6649   }
6650 }
6651
6652 Decl *ASTImporter::Imported(Decl *From, Decl *To) {
6653   if (From->hasAttrs()) {
6654     for (Attr *FromAttr : From->getAttrs())
6655       To->addAttr(FromAttr->clone(To->getASTContext()));
6656   }
6657   if (From->isUsed()) {
6658     To->setIsUsed();
6659   }
6660   if (From->isImplicit()) {
6661     To->setImplicit();
6662   }
6663   ImportedDecls[From] = To;
6664   return To;
6665 }
6666
6667 bool ASTImporter::IsStructurallyEquivalent(QualType From, QualType To,
6668                                            bool Complain) {
6669   llvm::DenseMap<const Type *, const Type *>::iterator Pos
6670    = ImportedTypes.find(From.getTypePtr());
6671   if (Pos != ImportedTypes.end() && ToContext.hasSameType(Import(From), To))
6672     return true;
6673
6674   StructuralEquivalenceContext Ctx(FromContext, ToContext, NonEquivalentDecls,
6675                                    false, Complain);
6676   return Ctx.IsStructurallyEquivalent(From, To);
6677 }