YQ Connector: support managed ClickHouse

Со стороны dqrun можно обратиться к инстансу коннектора, который работает на streaming стенде, и извлечь данные из облачного CH.

1 files changed, 2952 insertions, 0 deletions

diff --git a/contrib/libs/clang16/include/clang/AST/DeclObjC.h b/contrib/libs/clang16/include/clang/AST/DeclObjC.h
new file mode 100644
index 0000000000..e079d5359d
--- /dev/null
+++ b/contrib/libs/clang16/include/clang/AST/DeclObjC.h
@@ -0,0 +1,2952 @@
+#pragma once
+
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-parameter"
+#endif
+
+//===- DeclObjC.h - Classes for representing declarations -------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the DeclObjC interface and subclasses.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_AST_DECLOBJC_H
+#define LLVM_CLANG_AST_DECLOBJC_H
+
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclBase.h"
+#include "clang/AST/DeclObjCCommon.h"
+#include "clang/AST/ExternalASTSource.h"
+#include "clang/AST/Redeclarable.h"
+#include "clang/AST/SelectorLocationsKind.h"
+#include "clang/AST/Type.h"
+#include "clang/Basic/IdentifierTable.h"
+#include "clang/Basic/LLVM.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Basic/Specifiers.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/MapVector.h"
+#include "llvm/ADT/PointerIntPair.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/iterator_range.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/TrailingObjects.h"
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <iterator>
+#include <string>
+#include <utility>
+
+namespace clang {
+
+class ASTContext;
+class CompoundStmt;
+class CXXCtorInitializer;
+class Expr;
+class ObjCCategoryDecl;
+class ObjCCategoryImplDecl;
+class ObjCImplementationDecl;
+class ObjCInterfaceDecl;
+class ObjCIvarDecl;
+class ObjCPropertyDecl;
+class ObjCPropertyImplDecl;
+class ObjCProtocolDecl;
+class Stmt;
+
+class ObjCListBase {
+protected:
+  /// List is an array of pointers to objects that are not owned by this object.
+  void **List = nullptr;
+  unsigned NumElts = 0;
+
+public:
+  ObjCListBase() = default;
+  ObjCListBase(const ObjCListBase &) = delete;
+  ObjCListBase &operator=(const ObjCListBase &) = delete;
+
+  unsigned size() const { return NumElts; }
+  bool empty() const { return NumElts == 0; }
+
+protected:
+  void set(void *const* InList, unsigned Elts, ASTContext &Ctx);
+};
+
+/// ObjCList - This is a simple template class used to hold various lists of
+/// decls etc, which is heavily used by the ObjC front-end.  This only use case
+/// this supports is setting the list all at once and then reading elements out
+/// of it.
+template <typename T>
+class ObjCList : public ObjCListBase {
+public:
+  void set(T* const* InList, unsigned Elts, ASTContext &Ctx) {
+    ObjCListBase::set(reinterpret_cast<void*const*>(InList), Elts, Ctx);
+  }
+
+  using iterator = T* const *;
+
+  iterator begin() const { return (iterator)List; }
+  iterator end() const { return (iterator)List+NumElts; }
+
+  T* operator[](unsigned Idx) const {
+    assert(Idx < NumElts && "Invalid access");
+    return (T*)List[Idx];
+  }
+};
+
+/// A list of Objective-C protocols, along with the source
+/// locations at which they were referenced.
+class ObjCProtocolList : public ObjCList<ObjCProtocolDecl> {
+  SourceLocation *Locations = nullptr;
+
+  using ObjCList<ObjCProtocolDecl>::set;
+
+public:
+  ObjCProtocolList() = default;
+
+  using loc_iterator = const SourceLocation *;
+
+  loc_iterator loc_begin() const { return Locations; }
+  loc_iterator loc_end() const { return Locations + size(); }
+
+  void set(ObjCProtocolDecl* const* InList, unsigned Elts,
+           const SourceLocation *Locs, ASTContext &Ctx);
+};
+
+/// ObjCMethodDecl - Represents an instance or class method declaration.
+/// ObjC methods can be declared within 4 contexts: class interfaces,
+/// categories, protocols, and class implementations. While C++ member
+/// functions leverage C syntax, Objective-C method syntax is modeled after
+/// Smalltalk (using colons to specify argument types/expressions).
+/// Here are some brief examples:
+///
+/// Setter/getter instance methods:
+/// - (void)setMenu:(NSMenu *)menu;
+/// - (NSMenu *)menu;
+///
+/// Instance method that takes 2 NSView arguments:
+/// - (void)replaceSubview:(NSView *)oldView with:(NSView *)newView;
+///
+/// Getter class method:
+/// + (NSMenu *)defaultMenu;
+///
+/// A selector represents a unique name for a method. The selector names for
+/// the above methods are setMenu:, menu, replaceSubview:with:, and defaultMenu.
+///
+class ObjCMethodDecl : public NamedDecl, public DeclContext {
+  // This class stores some data in DeclContext::ObjCMethodDeclBits
+  // to save some space. Use the provided accessors to access it.
+
+public:
+  enum ImplementationControl { None, Required, Optional };
+
+private:
+  /// Return type of this method.
+  QualType MethodDeclType;
+
+  /// Type source information for the return type.
+  TypeSourceInfo *ReturnTInfo;
+
+  /// Array of ParmVarDecls for the formal parameters of this method
+  /// and optionally followed by selector locations.
+  void *ParamsAndSelLocs = nullptr;
+  unsigned NumParams = 0;
+
+  /// List of attributes for this method declaration.
+  SourceLocation DeclEndLoc; // the location of the ';' or '{'.
+
+  /// The following are only used for method definitions, null otherwise.
+  LazyDeclStmtPtr Body;
+
+  /// SelfDecl - Decl for the implicit self parameter. This is lazily
+  /// constructed by createImplicitParams.
+  ImplicitParamDecl *SelfDecl = nullptr;
+
+  /// CmdDecl - Decl for the implicit _cmd parameter. This is lazily
+  /// constructed by createImplicitParams.
+  ImplicitParamDecl *CmdDecl = nullptr;
+
+  ObjCMethodDecl(SourceLocation beginLoc, SourceLocation endLoc,
+                 Selector SelInfo, QualType T, TypeSourceInfo *ReturnTInfo,
+                 DeclContext *contextDecl, bool isInstance = true,
+                 bool isVariadic = false, bool isPropertyAccessor = false,
+                 bool isSynthesizedAccessorStub = false, 
+                 bool isImplicitlyDeclared = false, bool isDefined = false,
+                 ImplementationControl impControl = None,
+                 bool HasRelatedResultType = false);
+
+  SelectorLocationsKind getSelLocsKind() const {
+    return static_cast<SelectorLocationsKind>(ObjCMethodDeclBits.SelLocsKind);
+  }
+
+  void setSelLocsKind(SelectorLocationsKind Kind) {
+    ObjCMethodDeclBits.SelLocsKind = Kind;
+  }
+
+  bool hasStandardSelLocs() const {
+    return getSelLocsKind() != SelLoc_NonStandard;
+  }
+
+  /// Get a pointer to the stored selector identifiers locations array.
+  /// No locations will be stored if HasStandardSelLocs is true.
+  SourceLocation *getStoredSelLocs() {
+    return reinterpret_cast<SourceLocation *>(getParams() + NumParams);
+  }
+  const SourceLocation *getStoredSelLocs() const {
+    return reinterpret_cast<const SourceLocation *>(getParams() + NumParams);
+  }
+
+  /// Get a pointer to the stored selector identifiers locations array.
+  /// No locations will be stored if HasStandardSelLocs is true.
+  ParmVarDecl **getParams() {
+    return reinterpret_cast<ParmVarDecl **>(ParamsAndSelLocs);
+  }
+  const ParmVarDecl *const *getParams() const {
+    return reinterpret_cast<const ParmVarDecl *const *>(ParamsAndSelLocs);
+  }
+
+  /// Get the number of stored selector identifiers locations.
+  /// No locations will be stored if HasStandardSelLocs is true.
+  unsigned getNumStoredSelLocs() const {
+    if (hasStandardSelLocs())
+      return 0;
+    return getNumSelectorLocs();
+  }
+
+  void setParamsAndSelLocs(ASTContext &C,
+                           ArrayRef<ParmVarDecl*> Params,
+                           ArrayRef<SourceLocation> SelLocs);
+
+  /// A definition will return its interface declaration.
+  /// An interface declaration will return its definition.
+  /// Otherwise it will return itself.
+  ObjCMethodDecl *getNextRedeclarationImpl() override;
+
+public:
+  friend class ASTDeclReader;
+  friend class ASTDeclWriter;
+
+  static ObjCMethodDecl *
+  Create(ASTContext &C, SourceLocation beginLoc, SourceLocation endLoc,
+         Selector SelInfo, QualType T, TypeSourceInfo *ReturnTInfo,
+         DeclContext *contextDecl, bool isInstance = true,
+         bool isVariadic = false, bool isPropertyAccessor = false,
+         bool isSynthesizedAccessorStub = false,
+         bool isImplicitlyDeclared = false, bool isDefined = false,
+         ImplementationControl impControl = None,
+         bool HasRelatedResultType = false);
+
+  static ObjCMethodDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+
+  ObjCMethodDecl *getCanonicalDecl() override;
+  const ObjCMethodDecl *getCanonicalDecl() const {
+    return const_cast<ObjCMethodDecl*>(this)->getCanonicalDecl();
+  }
+
+  ObjCDeclQualifier getObjCDeclQualifier() const {
+    return static_cast<ObjCDeclQualifier>(ObjCMethodDeclBits.objcDeclQualifier);
+  }
+
+  void setObjCDeclQualifier(ObjCDeclQualifier QV) {
+    ObjCMethodDeclBits.objcDeclQualifier = QV;
+  }
+
+  /// Determine whether this method has a result type that is related
+  /// to the message receiver's type.
+  bool hasRelatedResultType() const {
+    return ObjCMethodDeclBits.RelatedResultType;
+  }
+
+  /// Note whether this method has a related result type.
+  void setRelatedResultType(bool RRT = true) {
+    ObjCMethodDeclBits.RelatedResultType = RRT;
+  }
+
+  /// True if this is a method redeclaration in the same interface.
+  bool isRedeclaration() const { return ObjCMethodDeclBits.IsRedeclaration; }
+  void setIsRedeclaration(bool RD) { ObjCMethodDeclBits.IsRedeclaration = RD; }
+  void setAsRedeclaration(const ObjCMethodDecl *PrevMethod);
+
+  /// True if redeclared in the same interface.
+  bool hasRedeclaration() const { return ObjCMethodDeclBits.HasRedeclaration; }
+  void setHasRedeclaration(bool HRD) const {
+    ObjCMethodDeclBits.HasRedeclaration = HRD;
+  }
+
+  /// Returns the location where the declarator ends. It will be
+  /// the location of ';' for a method declaration and the location of '{'
+  /// for a method definition.
+  SourceLocation getDeclaratorEndLoc() const { return DeclEndLoc; }
+
+  // Location information, modeled after the Stmt API.
+  SourceLocation getBeginLoc() const LLVM_READONLY { return getLocation(); }
+  SourceLocation getEndLoc() const LLVM_READONLY;
+  SourceRange getSourceRange() const override LLVM_READONLY {
+    return SourceRange(getLocation(), getEndLoc());
+  }
+
+  SourceLocation getSelectorStartLoc() const {
+    if (isImplicit())
+      return getBeginLoc();
+    return getSelectorLoc(0);
+  }
+
+  SourceLocation getSelectorLoc(unsigned Index) const {
+    assert(Index < getNumSelectorLocs() && "Index out of range!");
+    if (hasStandardSelLocs())
+      return getStandardSelectorLoc(Index, getSelector(),
+                                   getSelLocsKind() == SelLoc_StandardWithSpace,
+                                    parameters(),
+                                   DeclEndLoc);
+    return getStoredSelLocs()[Index];
+  }
+
+  void getSelectorLocs(SmallVectorImpl<SourceLocation> &SelLocs) const;
+
+  unsigned getNumSelectorLocs() const {
+    if (isImplicit())
+      return 0;
+    Selector Sel = getSelector();
+    if (Sel.isUnarySelector())
+      return 1;
+    return Sel.getNumArgs();
+  }
+
+  ObjCInterfaceDecl *getClassInterface();
+  const ObjCInterfaceDecl *getClassInterface() const {
+    return const_cast<ObjCMethodDecl*>(this)->getClassInterface();
+  }
+
+  /// If this method is declared or implemented in a category, return
+  /// that category.
+  ObjCCategoryDecl *getCategory();
+  const ObjCCategoryDecl *getCategory() const {
+    return const_cast<ObjCMethodDecl*>(this)->getCategory();
+  }
+
+  Selector getSelector() const { return getDeclName().getObjCSelector(); }
+
+  QualType getReturnType() const { return MethodDeclType; }
+  void setReturnType(QualType T) { MethodDeclType = T; }
+  SourceRange getReturnTypeSourceRange() const;
+
+  /// Determine the type of an expression that sends a message to this
+  /// function. This replaces the type parameters with the types they would
+  /// get if the receiver was parameterless (e.g. it may replace the type
+  /// parameter with 'id').
+  QualType getSendResultType() const;
+
+  /// Determine the type of an expression that sends a message to this
+  /// function with the given receiver type.
+  QualType getSendResultType(QualType receiverType) const;
+
+  TypeSourceInfo *getReturnTypeSourceInfo() const { return ReturnTInfo; }
+  void setReturnTypeSourceInfo(TypeSourceInfo *TInfo) { ReturnTInfo = TInfo; }
+
+  // Iterator access to formal parameters.
+  unsigned param_size() const { return NumParams; }
+
+  using param_const_iterator = const ParmVarDecl *const *;
+  using param_iterator = ParmVarDecl *const *;
+  using param_range = llvm::iterator_range<param_iterator>;
+  using param_const_range = llvm::iterator_range<param_const_iterator>;
+
+  param_const_iterator param_begin() const {
+    return param_const_iterator(getParams());
+  }
+
+  param_const_iterator param_end() const {
+    return param_const_iterator(getParams() + NumParams);
+  }
+
+  param_iterator param_begin() { return param_iterator(getParams()); }
+  param_iterator param_end() { return param_iterator(getParams() + NumParams); }
+
+  // This method returns and of the parameters which are part of the selector
+  // name mangling requirements.
+  param_const_iterator sel_param_end() const {
+    return param_begin() + getSelector().getNumArgs();
+  }
+
+  // ArrayRef access to formal parameters.  This should eventually
+  // replace the iterator interface above.
+  ArrayRef<ParmVarDecl*> parameters() const {
+    return llvm::ArrayRef(const_cast<ParmVarDecl **>(getParams()), NumParams);
+  }
+
+  ParmVarDecl *getParamDecl(unsigned Idx) {
+    assert(Idx < NumParams && "Index out of bounds!");
+    return getParams()[Idx];
+  }
+  const ParmVarDecl *getParamDecl(unsigned Idx) const {
+    return const_cast<ObjCMethodDecl *>(this)->getParamDecl(Idx);
+  }
+
+  /// Sets the method's parameters and selector source locations.
+  /// If the method is implicit (not coming from source) \p SelLocs is
+  /// ignored.
+  void setMethodParams(ASTContext &C, ArrayRef<ParmVarDecl *> Params,
+                       ArrayRef<SourceLocation> SelLocs = std::nullopt);
+
+  // Iterator access to parameter types.
+  struct GetTypeFn {
+    QualType operator()(const ParmVarDecl *PD) const { return PD->getType(); }
+  };
+
+  using param_type_iterator =
+      llvm::mapped_iterator<param_const_iterator, GetTypeFn>;
+
+  param_type_iterator param_type_begin() const {
+    return llvm::map_iterator(param_begin(), GetTypeFn());
+  }
+
+  param_type_iterator param_type_end() const {
+    return llvm::map_iterator(param_end(), GetTypeFn());
+  }
+
+  /// createImplicitParams - Used to lazily create the self and cmd
+  /// implicit parameters. This must be called prior to using getSelfDecl()
+  /// or getCmdDecl(). The call is ignored if the implicit parameters
+  /// have already been created.
+  void createImplicitParams(ASTContext &Context, const ObjCInterfaceDecl *ID);
+
+  /// \return the type for \c self and set \arg selfIsPseudoStrong and
+  /// \arg selfIsConsumed accordingly.
+  QualType getSelfType(ASTContext &Context, const ObjCInterfaceDecl *OID,
+                       bool &selfIsPseudoStrong, bool &selfIsConsumed) const;
+
+  ImplicitParamDecl * getSelfDecl() const { return SelfDecl; }
+  void setSelfDecl(ImplicitParamDecl *SD) { SelfDecl = SD; }
+  ImplicitParamDecl * getCmdDecl() const { return CmdDecl; }
+  void setCmdDecl(ImplicitParamDecl *CD) { CmdDecl = CD; }
+
+  /// Determines the family of this method.
+  ObjCMethodFamily getMethodFamily() const;
+
+  bool isInstanceMethod() const { return ObjCMethodDeclBits.IsInstance; }
+  void setInstanceMethod(bool isInst) {
+    ObjCMethodDeclBits.IsInstance = isInst;
+  }
+
+  bool isVariadic() const { return ObjCMethodDeclBits.IsVariadic; }
+  void setVariadic(bool isVar) { ObjCMethodDeclBits.IsVariadic = isVar; }
+
+  bool isClassMethod() const { return !isInstanceMethod(); }
+
+  bool isPropertyAccessor() const {
+    return ObjCMethodDeclBits.IsPropertyAccessor;
+  }
+
+  void setPropertyAccessor(bool isAccessor) {
+    ObjCMethodDeclBits.IsPropertyAccessor = isAccessor;
+  }
+
+  bool isSynthesizedAccessorStub() const {
+    return ObjCMethodDeclBits.IsSynthesizedAccessorStub;
+  }
+
+  void setSynthesizedAccessorStub(bool isSynthesizedAccessorStub) {
+    ObjCMethodDeclBits.IsSynthesizedAccessorStub = isSynthesizedAccessorStub;
+  }
+
+  bool isDefined() const { return ObjCMethodDeclBits.IsDefined; }
+  void setDefined(bool isDefined) { ObjCMethodDeclBits.IsDefined = isDefined; }
+
+  /// Whether this method overrides any other in the class hierarchy.
+  ///
+  /// A method is said to override any method in the class's
+  /// base classes, its protocols, or its categories' protocols, that has
+  /// the same selector and is of the same kind (class or instance).
+  /// A method in an implementation is not considered as overriding the same
+  /// method in the interface or its categories.
+  bool isOverriding() const { return ObjCMethodDeclBits.IsOverriding; }
+  void setOverriding(bool IsOver) { ObjCMethodDeclBits.IsOverriding = IsOver; }
+
+  /// Return overridden methods for the given \p Method.
+  ///
+  /// An ObjC method is considered to override any method in the class's
+  /// base classes (and base's categories), its protocols, or its categories'
+  /// protocols, that has
+  /// the same selector and is of the same kind (class or instance).
+  /// A method in an implementation is not considered as overriding the same
+  /// method in the interface or its categories.
+  void getOverriddenMethods(
+                     SmallVectorImpl<const ObjCMethodDecl *> &Overridden) const;
+
+  /// True if the method was a definition but its body was skipped.
+  bool hasSkippedBody() const { return ObjCMethodDeclBits.HasSkippedBody; }
+  void setHasSkippedBody(bool Skipped = true) {
+    ObjCMethodDeclBits.HasSkippedBody = Skipped;
+  }
+
+  /// True if the method is tagged as objc_direct
+  bool isDirectMethod() const;
+
+  /// True if the method has a parameter that's destroyed in the callee.
+  bool hasParamDestroyedInCallee() const;
+
+  /// Returns the property associated with this method's selector.
+  ///
+  /// Note that even if this particular method is not marked as a property
+  /// accessor, it is still possible for it to match a property declared in a
+  /// superclass. Pass \c false if you only want to check the current class.
+  const ObjCPropertyDecl *findPropertyDecl(bool CheckOverrides = true) const;
+
+  // Related to protocols declared in  \@protocol
+  void setDeclImplementation(ImplementationControl ic) {
+    ObjCMethodDeclBits.DeclImplementation = ic;
+  }
+
+  ImplementationControl getImplementationControl() const {
+    return ImplementationControl(ObjCMethodDeclBits.DeclImplementation);
+  }
+
+  bool isOptional() const {
+    return getImplementationControl() == Optional;
+  }
+
+  /// Returns true if this specific method declaration is marked with the
+  /// designated initializer attribute.
+  bool isThisDeclarationADesignatedInitializer() const;
+
+  /// Returns true if the method selector resolves to a designated initializer
+  /// in the class's interface.
+  ///
+  /// \param InitMethod if non-null and the function returns true, it receives
+  /// the method declaration that was marked with the designated initializer
+  /// attribute.
+  bool isDesignatedInitializerForTheInterface(
+      const ObjCMethodDecl **InitMethod = nullptr) const;
+
+  /// Determine whether this method has a body.
+  bool hasBody() const override { return Body.isValid(); }
+
+  /// Retrieve the body of this method, if it has one.
+  Stmt *getBody() const override;
+
+  void setLazyBody(uint64_t Offset) { Body = Offset; }
+
+  CompoundStmt *getCompoundBody() { return (CompoundStmt*)getBody(); }
+  void setBody(Stmt *B) { Body = B; }
+
+  /// Returns whether this specific method is a definition.
+  bool isThisDeclarationADefinition() const { return hasBody(); }
+
+  /// Is this method defined in the NSObject base class?
+  bool definedInNSObject(const ASTContext &) const;
+
+  // Implement isa/cast/dyncast/etc.
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+  static bool classofKind(Kind K) { return K == ObjCMethod; }
+
+  static DeclContext *castToDeclContext(const ObjCMethodDecl *D) {
+    return static_cast<DeclContext *>(const_cast<ObjCMethodDecl*>(D));
+  }
+
+  static ObjCMethodDecl *castFromDeclContext(const DeclContext *DC) {
+    return static_cast<ObjCMethodDecl *>(const_cast<DeclContext*>(DC));
+  }
+};
+
+/// Describes the variance of a given generic parameter.
+enum class ObjCTypeParamVariance : uint8_t {
+  /// The parameter is invariant: must match exactly.
+  Invariant,
+
+  /// The parameter is covariant, e.g., X<T> is a subtype of X<U> when
+  /// the type parameter is covariant and T is a subtype of U.
+  Covariant,
+
+  /// The parameter is contravariant, e.g., X<T> is a subtype of X<U>
+  /// when the type parameter is covariant and U is a subtype of T.
+  Contravariant,
+};
+
+/// Represents the declaration of an Objective-C type parameter.
+///
+/// \code
+/// @interface NSDictionary<Key : id<NSCopying>, Value>
+/// @end
+/// \endcode
+///
+/// In the example above, both \c Key and \c Value are represented by
+/// \c ObjCTypeParamDecl. \c Key has an explicit bound of \c id<NSCopying>,
+/// while \c Value gets an implicit bound of \c id.
+///
+/// Objective-C type parameters are typedef-names in the grammar,
+class ObjCTypeParamDecl : public TypedefNameDecl {
+  /// Index of this type parameter in the type parameter list.
+  unsigned Index : 14;
+
+  /// The variance of the type parameter.
+  unsigned Variance : 2;
+
+  /// The location of the variance, if any.
+  SourceLocation VarianceLoc;
+
+  /// The location of the ':', which will be valid when the bound was
+  /// explicitly specified.
+  SourceLocation ColonLoc;
+
+  ObjCTypeParamDecl(ASTContext &ctx, DeclContext *dc,
+                    ObjCTypeParamVariance variance, SourceLocation varianceLoc,
+                    unsigned index,
+                    SourceLocation nameLoc, IdentifierInfo *name,
+                    SourceLocation colonLoc, TypeSourceInfo *boundInfo)
+      : TypedefNameDecl(ObjCTypeParam, ctx, dc, nameLoc, nameLoc, name,
+                        boundInfo),
+        Index(index), Variance(static_cast<unsigned>(variance)),
+        VarianceLoc(varianceLoc), ColonLoc(colonLoc) {}
+
+  void anchor() override;
+
+public:
+  friend class ASTDeclReader;
+  friend class ASTDeclWriter;
+
+  static ObjCTypeParamDecl *Create(ASTContext &ctx, DeclContext *dc,
+                                   ObjCTypeParamVariance variance,
+                                   SourceLocation varianceLoc,
+                                   unsigned index,
+                                   SourceLocation nameLoc,
+                                   IdentifierInfo *name,
+                                   SourceLocation colonLoc,
+                                   TypeSourceInfo *boundInfo);
+  static ObjCTypeParamDecl *CreateDeserialized(ASTContext &ctx, unsigned ID);
+
+  SourceRange getSourceRange() const override LLVM_READONLY;
+
+  /// Determine the variance of this type parameter.
+  ObjCTypeParamVariance getVariance() const {
+    return static_cast<ObjCTypeParamVariance>(Variance);
+  }
+
+  /// Set the variance of this type parameter.
+  void setVariance(ObjCTypeParamVariance variance) {
+    Variance = static_cast<unsigned>(variance);
+  }
+
+  /// Retrieve the location of the variance keyword.
+  SourceLocation getVarianceLoc() const { return VarianceLoc; }
+
+  /// Retrieve the index into its type parameter list.
+  unsigned getIndex() const { return Index; }
+
+  /// Whether this type parameter has an explicitly-written type bound, e.g.,
+  /// "T : NSView".
+  bool hasExplicitBound() const { return ColonLoc.isValid(); }
+
+  /// Retrieve the location of the ':' separating the type parameter name
+  /// from the explicitly-specified bound.
+  SourceLocation getColonLoc() const { return ColonLoc; }
+
+  // Implement isa/cast/dyncast/etc.
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+  static bool classofKind(Kind K) { return K == ObjCTypeParam; }
+};
+
+/// Stores a list of Objective-C type parameters for a parameterized class
+/// or a category/extension thereof.
+///
+/// \code
+/// @interface NSArray<T> // stores the <T>
+/// @end
+/// \endcode
+class ObjCTypeParamList final
+    : private llvm::TrailingObjects<ObjCTypeParamList, ObjCTypeParamDecl *> {
+  /// Location of the left and right angle brackets.
+  SourceRange Brackets;
+  /// The number of parameters in the list, which are tail-allocated.
+  unsigned NumParams;
+
+  ObjCTypeParamList(SourceLocation lAngleLoc,
+                    ArrayRef<ObjCTypeParamDecl *> typeParams,
+                    SourceLocation rAngleLoc);
+
+public:
+  friend TrailingObjects;
+
+  /// Create a new Objective-C type parameter list.
+  static ObjCTypeParamList *create(ASTContext &ctx,
+                                   SourceLocation lAngleLoc,
+                                   ArrayRef<ObjCTypeParamDecl *> typeParams,
+                                   SourceLocation rAngleLoc);
+
+  /// Iterate through the type parameters in the list.
+  using iterator = ObjCTypeParamDecl **;
+
+  iterator begin() { return getTrailingObjects<ObjCTypeParamDecl *>(); }
+
+  iterator end() { return begin() + size(); }
+
+  /// Determine the number of type parameters in this list.
+  unsigned size() const { return NumParams; }
+
+  // Iterate through the type parameters in the list.
+  using const_iterator = ObjCTypeParamDecl * const *;
+
+  const_iterator begin() const {
+    return getTrailingObjects<ObjCTypeParamDecl *>();
+  }
+
+  const_iterator end() const {
+    return begin() + size();
+  }
+
+  ObjCTypeParamDecl *front() const {
+    assert(size() > 0 && "empty Objective-C type parameter list");
+    return *begin();
+  }
+
+  ObjCTypeParamDecl *back() const {
+    assert(size() > 0 && "empty Objective-C type parameter list");
+    return *(end() - 1);
+  }
+
+  SourceLocation getLAngleLoc() const { return Brackets.getBegin(); }
+  SourceLocation getRAngleLoc() const { return Brackets.getEnd(); }
+  SourceRange getSourceRange() const { return Brackets; }
+
+  /// Gather the default set of type arguments to be substituted for
+  /// these type parameters when dealing with an unspecialized type.
+  void gatherDefaultTypeArgs(SmallVectorImpl<QualType> &typeArgs) const;
+};
+
+enum class ObjCPropertyQueryKind : uint8_t {
+  OBJC_PR_query_unknown = 0x00,
+  OBJC_PR_query_instance,
+  OBJC_PR_query_class
+};
+
+/// Represents one property declaration in an Objective-C interface.
+///
+/// For example:
+/// \code{.mm}
+/// \@property (assign, readwrite) int MyProperty;
+/// \endcode
+class ObjCPropertyDecl : public NamedDecl {
+  void anchor() override;
+
+public:
+  enum SetterKind { Assign, Retain, Copy, Weak };
+  enum PropertyControl { None, Required, Optional };
+
+private:
+  // location of \@property
+  SourceLocation AtLoc;
+
+  // location of '(' starting attribute list or null.
+  SourceLocation LParenLoc;
+
+  QualType DeclType;
+  TypeSourceInfo *DeclTypeSourceInfo;
+  unsigned PropertyAttributes : NumObjCPropertyAttrsBits;
+  unsigned PropertyAttributesAsWritten : NumObjCPropertyAttrsBits;
+
+  // \@required/\@optional
+  unsigned PropertyImplementation : 2;
+
+  // getter name of NULL if no getter
+  Selector GetterName;
+
+  // setter name of NULL if no setter
+  Selector SetterName;
+
+  // location of the getter attribute's value
+  SourceLocation GetterNameLoc;
+
+  // location of the setter attribute's value
+  SourceLocation SetterNameLoc;
+
+  // Declaration of getter instance method
+  ObjCMethodDecl *GetterMethodDecl = nullptr;
+
+  // Declaration of setter instance method
+  ObjCMethodDecl *SetterMethodDecl = nullptr;
+
+  // Synthesize ivar for this property
+  ObjCIvarDecl *PropertyIvarDecl = nullptr;
+
+  ObjCPropertyDecl(DeclContext *DC, SourceLocation L, IdentifierInfo *Id,
+                   SourceLocation AtLocation, SourceLocation LParenLocation,
+                   QualType T, TypeSourceInfo *TSI, PropertyControl propControl)
+      : NamedDecl(ObjCProperty, DC, L, Id), AtLoc(AtLocation),
+        LParenLoc(LParenLocation), DeclType(T), DeclTypeSourceInfo(TSI),
+        PropertyAttributes(ObjCPropertyAttribute::kind_noattr),
+        PropertyAttributesAsWritten(ObjCPropertyAttribute::kind_noattr),
+        PropertyImplementation(propControl) {}
+
+public:
+  static ObjCPropertyDecl *
+  Create(ASTContext &C, DeclContext *DC, SourceLocation L, IdentifierInfo *Id,
+         SourceLocation AtLocation, SourceLocation LParenLocation, QualType T,
+         TypeSourceInfo *TSI, PropertyControl propControl = None);
+
+  static ObjCPropertyDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+
+  SourceLocation getAtLoc() const { return AtLoc; }
+  void setAtLoc(SourceLocation L) { AtLoc = L; }
+
+  SourceLocation getLParenLoc() const { return LParenLoc; }
+  void setLParenLoc(SourceLocation L) { LParenLoc = L; }
+
+  TypeSourceInfo *getTypeSourceInfo() const { return DeclTypeSourceInfo; }
+
+  QualType getType() const { return DeclType; }
+
+  void setType(QualType T, TypeSourceInfo *TSI) {
+    DeclType = T;
+    DeclTypeSourceInfo = TSI;
+  }
+
+  /// Retrieve the type when this property is used with a specific base object
+  /// type.
+  QualType getUsageType(QualType objectType) const;
+
+  ObjCPropertyAttribute::Kind getPropertyAttributes() const {
+    return ObjCPropertyAttribute::Kind(PropertyAttributes);
+  }
+
+  void setPropertyAttributes(ObjCPropertyAttribute::Kind PRVal) {
+    PropertyAttributes |= PRVal;
+  }
+
+  void overwritePropertyAttributes(unsigned PRVal) {
+    PropertyAttributes = PRVal;
+  }
+
+  ObjCPropertyAttribute::Kind getPropertyAttributesAsWritten() const {
+    return ObjCPropertyAttribute::Kind(PropertyAttributesAsWritten);
+  }
+
+  void setPropertyAttributesAsWritten(ObjCPropertyAttribute::Kind PRVal) {
+    PropertyAttributesAsWritten = PRVal;
+  }
+
+  // Helper methods for accessing attributes.
+
+  /// isReadOnly - Return true iff the property has a setter.
+  bool isReadOnly() const {
+    return (PropertyAttributes & ObjCPropertyAttribute::kind_readonly);
+  }
+
+  /// isAtomic - Return true if the property is atomic.
+  bool isAtomic() const {
+    return (PropertyAttributes & ObjCPropertyAttribute::kind_atomic);
+  }
+
+  /// isRetaining - Return true if the property retains its value.
+  bool isRetaining() const {
+    return (PropertyAttributes & (ObjCPropertyAttribute::kind_retain |
+                                  ObjCPropertyAttribute::kind_strong |
+                                  ObjCPropertyAttribute::kind_copy));
+  }
+
+  bool isInstanceProperty() const { return !isClassProperty(); }
+  bool isClassProperty() const {
+    return PropertyAttributes & ObjCPropertyAttribute::kind_class;
+  }
+  bool isDirectProperty() const;
+
+  ObjCPropertyQueryKind getQueryKind() const {
+    return isClassProperty() ? ObjCPropertyQueryKind::OBJC_PR_query_class :
+                               ObjCPropertyQueryKind::OBJC_PR_query_instance;
+  }
+
+  static ObjCPropertyQueryKind getQueryKind(bool isClassProperty) {
+    return isClassProperty ? ObjCPropertyQueryKind::OBJC_PR_query_class :
+                             ObjCPropertyQueryKind::OBJC_PR_query_instance;
+  }
+
+  /// getSetterKind - Return the method used for doing assignment in
+  /// the property setter. This is only valid if the property has been
+  /// defined to have a setter.
+  SetterKind getSetterKind() const {
+    if (PropertyAttributes & ObjCPropertyAttribute::kind_strong)
+      return getType()->isBlockPointerType() ? Copy : Retain;
+    if (PropertyAttributes & ObjCPropertyAttribute::kind_retain)
+      return Retain;
+    if (PropertyAttributes & ObjCPropertyAttribute::kind_copy)
+      return Copy;
+    if (PropertyAttributes & ObjCPropertyAttribute::kind_weak)
+      return Weak;
+    return Assign;
+  }
+
+  Selector getGetterName() const { return GetterName; }
+  SourceLocation getGetterNameLoc() const { return GetterNameLoc; }
+
+  void setGetterName(Selector Sel, SourceLocation Loc = SourceLocation()) {
+    GetterName = Sel;
+    GetterNameLoc = Loc;
+  }
+
+  Selector getSetterName() const { return SetterName; }
+  SourceLocation getSetterNameLoc() const { return SetterNameLoc; }
+
+  void setSetterName(Selector Sel, SourceLocation Loc = SourceLocation()) {
+    SetterName = Sel;
+    SetterNameLoc = Loc;
+  }
+
+  ObjCMethodDecl *getGetterMethodDecl() const { return GetterMethodDecl; }
+  void setGetterMethodDecl(ObjCMethodDecl *gDecl) { GetterMethodDecl = gDecl; }
+
+  ObjCMethodDecl *getSetterMethodDecl() const { return SetterMethodDecl; }
+  void setSetterMethodDecl(ObjCMethodDecl *gDecl) { SetterMethodDecl = gDecl; }
+
+  // Related to \@optional/\@required declared in \@protocol
+  void setPropertyImplementation(PropertyControl pc) {
+    PropertyImplementation = pc;
+  }
+
+  PropertyControl getPropertyImplementation() const {
+    return PropertyControl(PropertyImplementation);
+  }
+
+  bool isOptional() const {
+    return getPropertyImplementation() == PropertyControl::Optional;
+  }
+
+  void setPropertyIvarDecl(ObjCIvarDecl *Ivar) {
+    PropertyIvarDecl = Ivar;
+  }
+
+  ObjCIvarDecl *getPropertyIvarDecl() const {
+    return PropertyIvarDecl;
+  }
+
+  SourceRange getSourceRange() const override LLVM_READONLY {
+    return SourceRange(AtLoc, getLocation());
+  }
+
+  /// Get the default name of the synthesized ivar.
+  IdentifierInfo *getDefaultSynthIvarName(ASTContext &Ctx) const;
+
+  /// Lookup a property by name in the specified DeclContext.
+  static ObjCPropertyDecl *findPropertyDecl(const DeclContext *DC,
+                                            const IdentifierInfo *propertyID,
+                                            ObjCPropertyQueryKind queryKind);
+
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+  static bool classofKind(Kind K) { return K == ObjCProperty; }
+};
+
+/// ObjCContainerDecl - Represents a container for method declarations.
+/// Current sub-classes are ObjCInterfaceDecl, ObjCCategoryDecl,
+/// ObjCProtocolDecl, and ObjCImplDecl.
+///
+class ObjCContainerDecl : public NamedDecl, public DeclContext {
+  // This class stores some data in DeclContext::ObjCContainerDeclBits
+  // to save some space. Use the provided accessors to access it.
+
+  // These two locations in the range mark the end of the method container.
+  // The first points to the '@' token, and the second to the 'end' token.
+  SourceRange AtEnd;
+
+  void anchor() override;
+
+public:
+  ObjCContainerDecl(Kind DK, DeclContext *DC, IdentifierInfo *Id,
+                    SourceLocation nameLoc, SourceLocation atStartLoc);
+
+  // Iterator access to instance/class properties.
+  using prop_iterator = specific_decl_iterator<ObjCPropertyDecl>;
+  using prop_range =
+      llvm::iterator_range<specific_decl_iterator<ObjCPropertyDecl>>;
+
+  prop_range properties() const { return prop_range(prop_begin(), prop_end()); }
+
+  prop_iterator prop_begin() const {
+    return prop_iterator(decls_begin());
+  }
+
+  prop_iterator prop_end() const {
+    return prop_iterator(decls_end());
+  }
+
+  using instprop_iterator =
+      filtered_decl_iterator<ObjCPropertyDecl,
+                             &ObjCPropertyDecl::isInstanceProperty>;
+  using instprop_range = llvm::iterator_range<instprop_iterator>;
+
+  instprop_range instance_properties() const {
+    return instprop_range(instprop_begin(), instprop_end());
+  }
+
+  instprop_iterator instprop_begin() const {
+    return instprop_iterator(decls_begin());
+  }
+
+  instprop_iterator instprop_end() const {
+    return instprop_iterator(decls_end());
+  }
+
+  using classprop_iterator =
+      filtered_decl_iterator<ObjCPropertyDecl,
+                             &ObjCPropertyDecl::isClassProperty>;
+  using classprop_range = llvm::iterator_range<classprop_iterator>;
+
+  classprop_range class_properties() const {
+    return classprop_range(classprop_begin(), classprop_end());
+  }
+
+  classprop_iterator classprop_begin() const {
+    return classprop_iterator(decls_begin());
+  }
+
+  classprop_iterator classprop_end() const {
+    return classprop_iterator(decls_end());
+  }
+
+  // Iterator access to instance/class methods.
+  using method_iterator = specific_decl_iterator<ObjCMethodDecl>;
+  using method_range =
+      llvm::iterator_range<specific_decl_iterator<ObjCMethodDecl>>;
+
+  method_range methods() const {
+    return method_range(meth_begin(), meth_end());
+  }
+
+  method_iterator meth_begin() const {
+    return method_iterator(decls_begin());
+  }
+
+  method_iterator meth_end() const {
+    return method_iterator(decls_end());
+  }
+
+  using instmeth_iterator =
+      filtered_decl_iterator<ObjCMethodDecl,
+                             &ObjCMethodDecl::isInstanceMethod>;
+  using instmeth_range = llvm::iterator_range<instmeth_iterator>;
+
+  instmeth_range instance_methods() const {
+    return instmeth_range(instmeth_begin(), instmeth_end());
+  }
+
+  instmeth_iterator instmeth_begin() const {
+    return instmeth_iterator(decls_begin());
+  }
+
+  instmeth_iterator instmeth_end() const {
+    return instmeth_iterator(decls_end());
+  }
+
+  using classmeth_iterator =
+      filtered_decl_iterator<ObjCMethodDecl,
+                             &ObjCMethodDecl::isClassMethod>;
+  using classmeth_range = llvm::iterator_range<classmeth_iterator>;
+
+  classmeth_range class_methods() const {
+    return classmeth_range(classmeth_begin(), classmeth_end());
+  }
+
+  classmeth_iterator classmeth_begin() const {
+    return classmeth_iterator(decls_begin());
+  }
+
+  classmeth_iterator classmeth_end() const {
+    return classmeth_iterator(decls_end());
+  }
+
+  // Get the local instance/class method declared in this interface.
+  ObjCMethodDecl *getMethod(Selector Sel, bool isInstance,
+                            bool AllowHidden = false) const;
+
+  ObjCMethodDecl *getInstanceMethod(Selector Sel,
+                                    bool AllowHidden = false) const {
+    return getMethod(Sel, true/*isInstance*/, AllowHidden);
+  }
+
+  ObjCMethodDecl *getClassMethod(Selector Sel, bool AllowHidden = false) const {
+    return getMethod(Sel, false/*isInstance*/, AllowHidden);
+  }
+
+  bool HasUserDeclaredSetterMethod(const ObjCPropertyDecl *P) const;
+  ObjCIvarDecl *getIvarDecl(IdentifierInfo *Id) const;
+
+  ObjCPropertyDecl *getProperty(const IdentifierInfo *Id,
+                                bool IsInstance) const;
+
+  ObjCPropertyDecl *
+  FindPropertyDeclaration(const IdentifierInfo *PropertyId,
+                          ObjCPropertyQueryKind QueryKind) const;
+
+  using PropertyMap =
+      llvm::MapVector<std::pair<IdentifierInfo *, unsigned /*isClassProperty*/>,
+                      ObjCPropertyDecl *>;
+  using ProtocolPropertySet = llvm::SmallDenseSet<const ObjCProtocolDecl *, 8>;
+  using PropertyDeclOrder = llvm::SmallVector<ObjCPropertyDecl *, 8>;
+
+  /// This routine collects list of properties to be implemented in the class.
+  /// This includes, class's and its conforming protocols' properties.
+  /// Note, the superclass's properties are not included in the list.
+  virtual void collectPropertiesToImplement(PropertyMap &PM) const {}
+
+  SourceLocation getAtStartLoc() const { return ObjCContainerDeclBits.AtStart; }
+
+  void setAtStartLoc(SourceLocation Loc) {
+    ObjCContainerDeclBits.AtStart = Loc;
+  }
+
+  // Marks the end of the container.
+  SourceRange getAtEndRange() const { return AtEnd; }
+
+  void setAtEndRange(SourceRange atEnd) { AtEnd = atEnd; }
+
+  SourceRange getSourceRange() const override LLVM_READONLY {
+    return SourceRange(getAtStartLoc(), getAtEndRange().getEnd());
+  }
+
+  // Implement isa/cast/dyncast/etc.
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+
+  static bool classofKind(Kind K) {
+    return K >= firstObjCContainer &&
+           K <= lastObjCContainer;
+  }
+
+  static DeclContext *castToDeclContext(const ObjCContainerDecl *D) {
+    return static_cast<DeclContext *>(const_cast<ObjCContainerDecl*>(D));
+  }
+
+  static ObjCContainerDecl *castFromDeclContext(const DeclContext *DC) {
+    return static_cast<ObjCContainerDecl *>(const_cast<DeclContext*>(DC));
+  }
+};
+
+/// Represents an ObjC class declaration.
+///
+/// For example:
+///
+/// \code
+///   // MostPrimitive declares no super class (not particularly useful).
+///   \@interface MostPrimitive
+///     // no instance variables or methods.
+///   \@end
+///
+///   // NSResponder inherits from NSObject & implements NSCoding (a protocol).
+///   \@interface NSResponder : NSObject \<NSCoding>
+///   { // instance variables are represented by ObjCIvarDecl.
+///     id nextResponder; // nextResponder instance variable.
+///   }
+///   - (NSResponder *)nextResponder; // return a pointer to NSResponder.
+///   - (void)mouseMoved:(NSEvent *)theEvent; // return void, takes a pointer
+///   \@end                                    // to an NSEvent.
+/// \endcode
+///
+///   Unlike C/C++, forward class declarations are accomplished with \@class.
+///   Unlike C/C++, \@class allows for a list of classes to be forward declared.
+///   Unlike C++, ObjC is a single-rooted class model. In Cocoa, classes
+///   typically inherit from NSObject (an exception is NSProxy).
+///
+class ObjCInterfaceDecl : public ObjCContainerDecl
+                        , public Redeclarable<ObjCInterfaceDecl> {
+  friend class ASTContext;
+  friend class ODRDiagsEmitter;
+
+  /// TypeForDecl - This indicates the Type object that represents this
+  /// TypeDecl.  It is a cache maintained by ASTContext::getObjCInterfaceType
+  mutable const Type *TypeForDecl = nullptr;
+
+  struct DefinitionData {
+    /// The definition of this class, for quick access from any
+    /// declaration.
+    ObjCInterfaceDecl *Definition = nullptr;
+
+    /// When non-null, this is always an ObjCObjectType.
+    TypeSourceInfo *SuperClassTInfo = nullptr;
+
+    /// Protocols referenced in the \@interface  declaration
+    ObjCProtocolList ReferencedProtocols;
+
+    /// Protocols reference in both the \@interface and class extensions.
+    ObjCList<ObjCProtocolDecl> AllReferencedProtocols;
+
+    /// List of categories and class extensions defined for this class.
+    ///
+    /// Categories are stored as a linked list in the AST, since the categories
+    /// and class extensions come long after the initial interface declaration,
+    /// and we avoid dynamically-resized arrays in the AST wherever possible.
+    ObjCCategoryDecl *CategoryList = nullptr;
+
+    /// IvarList - List of all ivars defined by this class; including class
+    /// extensions and implementation. This list is built lazily.
+    ObjCIvarDecl *IvarList = nullptr;
+
+    /// Indicates that the contents of this Objective-C class will be
+    /// completed by the external AST source when required.
+    mutable unsigned ExternallyCompleted : 1;
+
+    /// Indicates that the ivar cache does not yet include ivars
+    /// declared in the implementation.
+    mutable unsigned IvarListMissingImplementation : 1;
+
+    /// Indicates that this interface decl contains at least one initializer
+    /// marked with the 'objc_designated_initializer' attribute.
+    unsigned HasDesignatedInitializers : 1;
+
+    enum InheritedDesignatedInitializersState {
+      /// We didn't calculate whether the designated initializers should be
+      /// inherited or not.
+      IDI_Unknown = 0,
+
+      /// Designated initializers are inherited for the super class.
+      IDI_Inherited = 1,
+
+      /// The class does not inherit designated initializers.
+      IDI_NotInherited = 2
+    };
+
+    /// One of the \c InheritedDesignatedInitializersState enumeratos.
+    mutable unsigned InheritedDesignatedInitializers : 2;
+
+    /// Tracks whether a ODR hash has been computed for this interface.
+    unsigned HasODRHash : 1;
+
+    /// A hash of parts of the class to help in ODR checking.
+    unsigned ODRHash = 0;
+
+    /// The location of the last location in this declaration, before
+    /// the properties/methods. For example, this will be the '>', '}', or
+    /// identifier,
+    SourceLocation EndLoc;
+
+    DefinitionData()
+        : ExternallyCompleted(false), IvarListMissingImplementation(true),
+          HasDesignatedInitializers(false),
+          InheritedDesignatedInitializers(IDI_Unknown), HasODRHash(false) {}
+  };
+
+  /// The type parameters associated with this class, if any.
+  ObjCTypeParamList *TypeParamList = nullptr;
+
+  /// Contains a pointer to the data associated with this class,
+  /// which will be NULL if this class has not yet been defined.
+  ///
+  /// The bit indicates when we don't need to check for out-of-date
+  /// declarations. It will be set unless modules are enabled.
+  llvm::PointerIntPair<DefinitionData *, 1, bool> Data;
+
+  ObjCInterfaceDecl(const ASTContext &C, DeclContext *DC, SourceLocation AtLoc,
+                    IdentifierInfo *Id, ObjCTypeParamList *typeParamList,
+                    SourceLocation CLoc, ObjCInterfaceDecl *PrevDecl,
+                    bool IsInternal);
+
+  void anchor() override;
+
+  void LoadExternalDefinition() const;
+
+  DefinitionData &data() const {
+    assert(Data.getPointer() && "Declaration has no definition!");
+    return *Data.getPointer();
+  }
+
+  /// Allocate the definition data for this class.
+  void allocateDefinitionData();
+
+  using redeclarable_base = Redeclarable<ObjCInterfaceDecl>;
+
+  ObjCInterfaceDecl *getNextRedeclarationImpl() override {
+    return getNextRedeclaration();
+  }
+
+  ObjCInterfaceDecl *getPreviousDeclImpl() override {
+    return getPreviousDecl();
+  }
+
+  ObjCInterfaceDecl *getMostRecentDeclImpl() override {
+    return getMostRecentDecl();
+  }
+
+public:
+  static ObjCInterfaceDecl *Create(const ASTContext &C, DeclContext *DC,
+                                   SourceLocation atLoc,
+                                   IdentifierInfo *Id,
+                                   ObjCTypeParamList *typeParamList,
+                                   ObjCInterfaceDecl *PrevDecl,
+                                   SourceLocation ClassLoc = SourceLocation(),
+                                   bool isInternal = false);
+
+  static ObjCInterfaceDecl *CreateDeserialized(const ASTContext &C, unsigned ID);
+
+  /// Retrieve the type parameters of this class.
+  ///
+  /// This function looks for a type parameter list for the given
+  /// class; if the class has been declared (with \c \@class) but not
+  /// defined (with \c \@interface), it will search for a declaration that
+  /// has type parameters, skipping any declarations that do not.
+  ObjCTypeParamList *getTypeParamList() const;
+
+  /// Set the type parameters of this class.
+  ///
+  /// This function is used by the AST importer, which must import the type
+  /// parameters after creating their DeclContext to avoid loops.
+  void setTypeParamList(ObjCTypeParamList *TPL);
+
+  /// Retrieve the type parameters written on this particular declaration of
+  /// the class.
+  ObjCTypeParamList *getTypeParamListAsWritten() const {
+    return TypeParamList;
+  }
+
+  SourceRange getSourceRange() const override LLVM_READONLY {
+    if (isThisDeclarationADefinition())
+      return ObjCContainerDecl::getSourceRange();
+
+    return SourceRange(getAtStartLoc(), getLocation());
+  }
+
+  /// Indicate that this Objective-C class is complete, but that
+  /// the external AST source will be responsible for filling in its contents
+  /// when a complete class is required.
+  void setExternallyCompleted();
+
+  /// Indicate that this interface decl contains at least one initializer
+  /// marked with the 'objc_designated_initializer' attribute.
+  void setHasDesignatedInitializers();
+
+  /// Returns true if this interface decl contains at least one initializer
+  /// marked with the 'objc_designated_initializer' attribute.
+  bool hasDesignatedInitializers() const;
+
+  /// Returns true if this interface decl declares a designated initializer
+  /// or it inherites one from its super class.
+  bool declaresOrInheritsDesignatedInitializers() const {
+    return hasDesignatedInitializers() || inheritsDesignatedInitializers();
+  }
+
+  const ObjCProtocolList &getReferencedProtocols() const {
+    assert(hasDefinition() && "Caller did not check for forward reference!");
+    if (data().ExternallyCompleted)
+      LoadExternalDefinition();
+
+    return data().ReferencedProtocols;
+  }
+
+  ObjCImplementationDecl *getImplementation() const;
+  void setImplementation(ObjCImplementationDecl *ImplD);
+
+  ObjCCategoryDecl *FindCategoryDeclaration(IdentifierInfo *CategoryId) const;
+
+  // Get the local instance/class method declared in a category.
+  ObjCMethodDecl *getCategoryInstanceMethod(Selector Sel) const;
+  ObjCMethodDecl *getCategoryClassMethod(Selector Sel) const;
+
+  ObjCMethodDecl *getCategoryMethod(Selector Sel, bool isInstance) const {
+    return isInstance ? getCategoryInstanceMethod(Sel)
+                      : getCategoryClassMethod(Sel);
+  }
+
+  using protocol_iterator = ObjCProtocolList::iterator;
+  using protocol_range = llvm::iterator_range<protocol_iterator>;
+
+  protocol_range protocols() const {
+    return protocol_range(protocol_begin(), protocol_end());
+  }
+
+  protocol_iterator protocol_begin() const {
+    // FIXME: Should make sure no callers ever do this.
+    if (!hasDefinition())
+      return protocol_iterator();
+
+    if (data().ExternallyCompleted)
+      LoadExternalDefinition();
+
+    return data().ReferencedProtocols.begin();
+  }
+
+  protocol_iterator protocol_end() const {
+    // FIXME: Should make sure no callers ever do this.
+    if (!hasDefinition())
+      return protocol_iterator();
+
+    if (data().ExternallyCompleted)
+      LoadExternalDefinition();
+
+    return data().ReferencedProtocols.end();
+  }
+
+  using protocol_loc_iterator = ObjCProtocolList::loc_iterator;
+  using protocol_loc_range = llvm::iterator_range<protocol_loc_iterator>;
+
+  protocol_loc_range protocol_locs() const {
+    return protocol_loc_range(protocol_loc_begin(), protocol_loc_end());
+  }
+
+  protocol_loc_iterator protocol_loc_begin() const {
+    // FIXME: Should make sure no callers ever do this.
+    if (!hasDefinition())
+      return protocol_loc_iterator();
+
+    if (data().ExternallyCompleted)
+      LoadExternalDefinition();
+
+    return data().ReferencedProtocols.loc_begin();
+  }
+
+  protocol_loc_iterator protocol_loc_end() const {
+    // FIXME: Should make sure no callers ever do this.
+    if (!hasDefinition())
+      return protocol_loc_iterator();
+
+    if (data().ExternallyCompleted)
+      LoadExternalDefinition();
+
+    return data().ReferencedProtocols.loc_end();
+  }
+
+  using all_protocol_iterator = ObjCList<ObjCProtocolDecl>::iterator;
+  using all_protocol_range = llvm::iterator_range<all_protocol_iterator>;
+
+  all_protocol_range all_referenced_protocols() const {
+    return all_protocol_range(all_referenced_protocol_begin(),
+                              all_referenced_protocol_end());
+  }
+
+  all_protocol_iterator all_referenced_protocol_begin() const {
+    // FIXME: Should make sure no callers ever do this.
+    if (!hasDefinition())
+      return all_protocol_iterator();
+
+    if (data().ExternallyCompleted)
+      LoadExternalDefinition();
+
+    return data().AllReferencedProtocols.empty()
+             ? protocol_begin()
+             : data().AllReferencedProtocols.begin();
+  }
+
+  all_protocol_iterator all_referenced_protocol_end() const {
+    // FIXME: Should make sure no callers ever do this.
+    if (!hasDefinition())
+      return all_protocol_iterator();
+
+    if (data().ExternallyCompleted)
+      LoadExternalDefinition();
+
+    return data().AllReferencedProtocols.empty()
+             ? protocol_end()
+             : data().AllReferencedProtocols.end();
+  }
+
+  using ivar_iterator = specific_decl_iterator<ObjCIvarDecl>;
+  using ivar_range = llvm::iterator_range<specific_decl_iterator<ObjCIvarDecl>>;
+
+  ivar_range ivars() const { return ivar_range(ivar_begin(), ivar_end()); }
+
+  ivar_iterator ivar_begin() const {
+    if (const ObjCInterfaceDecl *Def = getDefinition())
+      return ivar_iterator(Def->decls_begin());
+
+    // FIXME: Should make sure no callers ever do this.
+    return ivar_iterator();
+  }
+
+  ivar_iterator ivar_end() const {
+    if (const ObjCInterfaceDecl *Def = getDefinition())
+      return ivar_iterator(Def->decls_end());
+
+    // FIXME: Should make sure no callers ever do this.
+    return ivar_iterator();
+  }
+
+  unsigned ivar_size() const {
+    return std::distance(ivar_begin(), ivar_end());
+  }
+
+  bool ivar_empty() const { return ivar_begin() == ivar_end(); }
+
+  ObjCIvarDecl *all_declared_ivar_begin();
+  const ObjCIvarDecl *all_declared_ivar_begin() const {
+    // Even though this modifies IvarList, it's conceptually const:
+    // the ivar chain is essentially a cached property of ObjCInterfaceDecl.
+    return const_cast<ObjCInterfaceDecl *>(this)->all_declared_ivar_begin();
+  }
+  void setIvarList(ObjCIvarDecl *ivar) { data().IvarList = ivar; }
+
+  /// setProtocolList - Set the list of protocols that this interface
+  /// implements.
+  void setProtocolList(ObjCProtocolDecl *const* List, unsigned Num,
+                       const SourceLocation *Locs, ASTContext &C) {
+    data().ReferencedProtocols.set(List, Num, Locs, C);
+  }
+
+  /// mergeClassExtensionProtocolList - Merge class extension's protocol list
+  /// into the protocol list for this class.
+  void mergeClassExtensionProtocolList(ObjCProtocolDecl *const* List,
+                                       unsigned Num,
+                                       ASTContext &C);
+
+  /// Produce a name to be used for class's metadata. It comes either via
+  /// objc_runtime_name attribute or class name.
+  StringRef getObjCRuntimeNameAsString() const;
+
+  /// Returns the designated initializers for the interface.
+  ///
+  /// If this declaration does not have methods marked as designated
+  /// initializers then the interface inherits the designated initializers of
+  /// its super class.
+  void getDesignatedInitializers(
+                  llvm::SmallVectorImpl<const ObjCMethodDecl *> &Methods) const;
+
+  /// Returns true if the given selector is a designated initializer for the
+  /// interface.
+  ///
+  /// If this declaration does not have methods marked as designated
+  /// initializers then the interface inherits the designated initializers of
+  /// its super class.
+  ///
+  /// \param InitMethod if non-null and the function returns true, it receives
+  /// the method that was marked as a designated initializer.
+  bool
+  isDesignatedInitializer(Selector Sel,
+                          const ObjCMethodDecl **InitMethod = nullptr) const;
+
+  /// Determine whether this particular declaration of this class is
+  /// actually also a definition.
+  bool isThisDeclarationADefinition() const {
+    return getDefinition() == this;
+  }
+
+  /// Determine whether this class has been defined.
+  bool hasDefinition() const {
+    // If the name of this class is out-of-date, bring it up-to-date, which
+    // might bring in a definition.
+    // Note: a null value indicates that we don't have a definition and that
+    // modules are enabled.
+    if (!Data.getOpaqueValue())
+      getMostRecentDecl();
+
+    return Data.getPointer();
+  }
+
+  /// Retrieve the definition of this class, or NULL if this class
+  /// has been forward-declared (with \@class) but not yet defined (with
+  /// \@interface).
+  ObjCInterfaceDecl *getDefinition() {
+    return hasDefinition()? Data.getPointer()->Definition : nullptr;
+  }
+
+  /// Retrieve the definition of this class, or NULL if this class
+  /// has been forward-declared (with \@class) but not yet defined (with
+  /// \@interface).
+  const ObjCInterfaceDecl *getDefinition() const {
+    return hasDefinition()? Data.getPointer()->Definition : nullptr;
+  }
+
+  /// Starts the definition of this Objective-C class, taking it from
+  /// a forward declaration (\@class) to a definition (\@interface).
+  void startDefinition();
+
+  /// Starts the definition without sharing it with other redeclarations.
+  /// Such definition shouldn't be used for anything but only to compare if
+  /// a duplicate is compatible with previous definition or if it is
+  /// a distinct duplicate.
+  void startDuplicateDefinitionForComparison();
+  void mergeDuplicateDefinitionWithCommon(const ObjCInterfaceDecl *Definition);
+
+  /// Retrieve the superclass type.
+  const ObjCObjectType *getSuperClassType() const {
+    if (TypeSourceInfo *TInfo = getSuperClassTInfo())
+      return TInfo->getType()->castAs<ObjCObjectType>();
+
+    return nullptr;
+  }
+
+  // Retrieve the type source information for the superclass.
+  TypeSourceInfo *getSuperClassTInfo() const {
+    // FIXME: Should make sure no callers ever do this.
+    if (!hasDefinition())
+      return nullptr;
+
+    if (data().ExternallyCompleted)
+      LoadExternalDefinition();
+
+    return data().SuperClassTInfo;
+  }
+
+  // Retrieve the declaration for the superclass of this class, which
+  // does not include any type arguments that apply to the superclass.
+  ObjCInterfaceDecl *getSuperClass() const;
+
+  void setSuperClass(TypeSourceInfo *superClass) {
+    data().SuperClassTInfo = superClass;
+  }
+
+  /// Iterator that walks over the list of categories, filtering out
+  /// those that do not meet specific criteria.
+  ///
+  /// This class template is used for the various permutations of category
+  /// and extension iterators.
+  template<bool (*Filter)(ObjCCategoryDecl *)>
+  class filtered_category_iterator {
+    ObjCCategoryDecl *Current = nullptr;
+
+    void findAcceptableCategory();
+
+  public:
+    using value_type = ObjCCategoryDecl *;
+    using reference = value_type;
+    using pointer = value_type;
+    using difference_type = std::ptrdiff_t;
+    using iterator_category = std::input_iterator_tag;
+
+    filtered_category_iterator() = default;
+    explicit filtered_category_iterator(ObjCCategoryDecl *Current)
+        : Current(Current) {
+      findAcceptableCategory();
+    }
+
+    reference operator*() const { return Current; }
+    pointer operator->() const { return Current; }
+
+    filtered_category_iterator &operator++();
+
+    filtered_category_iterator operator++(int) {
+      filtered_category_iterator Tmp = *this;
+      ++(*this);
+      return Tmp;
+    }
+
+    friend bool operator==(filtered_category_iterator X,
+                           filtered_category_iterator Y) {
+      return X.Current == Y.Current;
+    }
+
+    friend bool operator!=(filtered_category_iterator X,
+                           filtered_category_iterator Y) {
+      return X.Current != Y.Current;
+    }
+  };
+
+private:
+  /// Test whether the given category is visible.
+  ///
+  /// Used in the \c visible_categories_iterator.
+  static bool isVisibleCategory(ObjCCategoryDecl *Cat);
+
+public:
+  /// Iterator that walks over the list of categories and extensions
+  /// that are visible, i.e., not hidden in a non-imported submodule.
+  using visible_categories_iterator =
+      filtered_category_iterator<isVisibleCategory>;
+
+  using visible_categories_range =
+      llvm::iterator_range<visible_categories_iterator>;
+
+  visible_categories_range visible_categories() const {
+    return visible_categories_range(visible_categories_begin(),
+                                    visible_categories_end());
+  }
+
+  /// Retrieve an iterator to the beginning of the visible-categories
+  /// list.
+  visible_categories_iterator visible_categories_begin() const {
+    return visible_categories_iterator(getCategoryListRaw());
+  }
+
+  /// Retrieve an iterator to the end of the visible-categories list.
+  visible_categories_iterator visible_categories_end() const {
+    return visible_categories_iterator();
+  }
+
+  /// Determine whether the visible-categories list is empty.
+  bool visible_categories_empty() const {
+    return visible_categories_begin() == visible_categories_end();
+  }
+
+private:
+  /// Test whether the given category... is a category.
+  ///
+  /// Used in the \c known_categories_iterator.
+  static bool isKnownCategory(ObjCCategoryDecl *) { return true; }
+
+public:
+  /// Iterator that walks over all of the known categories and
+  /// extensions, including those that are hidden.
+  using known_categories_iterator = filtered_category_iterator<isKnownCategory>;
+  using known_categories_range =
+     llvm::iterator_range<known_categories_iterator>;
+
+  known_categories_range known_categories() const {
+    return known_categories_range(known_categories_begin(),
+                                  known_categories_end());
+  }
+
+  /// Retrieve an iterator to the beginning of the known-categories
+  /// list.
+  known_categories_iterator known_categories_begin() const {
+    return known_categories_iterator(getCategoryListRaw());
+  }
+
+  /// Retrieve an iterator to the end of the known-categories list.
+  known_categories_iterator known_categories_end() const {
+    return known_categories_iterator();
+  }
+
+  /// Determine whether the known-categories list is empty.
+  bool known_categories_empty() const {
+    return known_categories_begin() == known_categories_end();
+  }
+
+private:
+  /// Test whether the given category is a visible extension.
+  ///
+  /// Used in the \c visible_extensions_iterator.
+  static bool isVisibleExtension(ObjCCategoryDecl *Cat);
+
+public:
+  /// Iterator that walks over all of the visible extensions, skipping
+  /// any that are known but hidden.
+  using visible_extensions_iterator =
+      filtered_category_iterator<isVisibleExtension>;
+
+  using visible_extensions_range =
+      llvm::iterator_range<visible_extensions_iterator>;
+
+  visible_extensions_range visible_extensions() const {
+    return visible_extensions_range(visible_extensions_begin(),
+                                    visible_extensions_end());
+  }
+
+  /// Retrieve an iterator to the beginning of the visible-extensions
+  /// list.
+  visible_extensions_iterator visible_extensions_begin() const {
+    return visible_extensions_iterator(getCategoryListRaw());
+  }
+
+  /// Retrieve an iterator to the end of the visible-extensions list.
+  visible_extensions_iterator visible_extensions_end() const {
+    return visible_extensions_iterator();
+  }
+
+  /// Determine whether the visible-extensions list is empty.
+  bool visible_extensions_empty() const {
+    return visible_extensions_begin() == visible_extensions_end();
+  }
+
+private:
+  /// Test whether the given category is an extension.
+  ///
+  /// Used in the \c known_extensions_iterator.
+  static bool isKnownExtension(ObjCCategoryDecl *Cat);
+
+public:
+  friend class ASTDeclReader;
+  friend class ASTDeclWriter;
+  friend class ASTReader;
+
+  /// Iterator that walks over all of the known extensions.
+  using known_extensions_iterator =
+      filtered_category_iterator<isKnownExtension>;
+  using known_extensions_range =
+      llvm::iterator_range<known_extensions_iterator>;
+
+  known_extensions_range known_extensions() const {
+    return known_extensions_range(known_extensions_begin(),
+                                  known_extensions_end());
+  }
+
+  /// Retrieve an iterator to the beginning of the known-extensions
+  /// list.
+  known_extensions_iterator known_extensions_begin() const {
+    return known_extensions_iterator(getCategoryListRaw());
+  }
+
+  /// Retrieve an iterator to the end of the known-extensions list.
+  known_extensions_iterator known_extensions_end() const {
+    return known_extensions_iterator();
+  }
+
+  /// Determine whether the known-extensions list is empty.
+  bool known_extensions_empty() const {
+    return known_extensions_begin() == known_extensions_end();
+  }
+
+  /// Retrieve the raw pointer to the start of the category/extension
+  /// list.
+  ObjCCategoryDecl* getCategoryListRaw() const {
+    // FIXME: Should make sure no callers ever do this.
+    if (!hasDefinition())
+      return nullptr;
+
+    if (data().ExternallyCompleted)
+      LoadExternalDefinition();
+
+    return data().CategoryList;
+  }
+
+  /// Set the raw pointer to the start of the category/extension
+  /// list.
+  void setCategoryListRaw(ObjCCategoryDecl *category) {
+    data().CategoryList = category;
+  }
+
+  ObjCPropertyDecl
+    *FindPropertyVisibleInPrimaryClass(IdentifierInfo *PropertyId,
+                                       ObjCPropertyQueryKind QueryKind) const;
+
+  void collectPropertiesToImplement(PropertyMap &PM) const override;
+
+  /// isSuperClassOf - Return true if this class is the specified class or is a
+  /// super class of the specified interface class.
+  bool isSuperClassOf(const ObjCInterfaceDecl *I) const {
+    // If RHS is derived from LHS it is OK; else it is not OK.
+    while (I != nullptr) {
+      if (declaresSameEntity(this, I))
+        return true;
+
+      I = I->getSuperClass();
+    }
+    return false;
+  }
+
+  /// isArcWeakrefUnavailable - Checks for a class or one of its super classes
+  /// to be incompatible with __weak references. Returns true if it is.
+  bool isArcWeakrefUnavailable() const;
+
+  /// isObjCRequiresPropertyDefs - Checks that a class or one of its super
+  /// classes must not be auto-synthesized. Returns class decl. if it must not
+  /// be; 0, otherwise.
+  const ObjCInterfaceDecl *isObjCRequiresPropertyDefs() const;
+
+  ObjCIvarDecl *lookupInstanceVariable(IdentifierInfo *IVarName,
+                                       ObjCInterfaceDecl *&ClassDeclared);
+  ObjCIvarDecl *lookupInstanceVariable(IdentifierInfo *IVarName) {
+    ObjCInterfaceDecl *ClassDeclared;
+    return lookupInstanceVariable(IVarName, ClassDeclared);
+  }
+
+  ObjCProtocolDecl *lookupNestedProtocol(IdentifierInfo *Name);
+
+  // Lookup a method. First, we search locally. If a method isn't
+  // found, we search referenced protocols and class categories.
+  ObjCMethodDecl *lookupMethod(Selector Sel, bool isInstance,
+                               bool shallowCategoryLookup = false,
+                               bool followSuper = true,
+                               const ObjCCategoryDecl *C = nullptr) const;
+
+  /// Lookup an instance method for a given selector.
+  ObjCMethodDecl *lookupInstanceMethod(Selector Sel) const {
+    return lookupMethod(Sel, true/*isInstance*/);
+  }
+
+  /// Lookup a class method for a given selector.
+  ObjCMethodDecl *lookupClassMethod(Selector Sel) const {
+    return lookupMethod(Sel, false/*isInstance*/);
+  }
+
+  ObjCInterfaceDecl *lookupInheritedClass(const IdentifierInfo *ICName);
+
+  /// Lookup a method in the classes implementation hierarchy.
+  ObjCMethodDecl *lookupPrivateMethod(const Selector &Sel,
+                                      bool Instance=true) const;
+
+  ObjCMethodDecl *lookupPrivateClassMethod(const Selector &Sel) {
+    return lookupPrivateMethod(Sel, false);
+  }
+
+  /// Lookup a setter or getter in the class hierarchy,
+  /// including in all categories except for category passed
+  /// as argument.
+  ObjCMethodDecl *lookupPropertyAccessor(const Selector Sel,
+                                         const ObjCCategoryDecl *Cat,
+                                         bool IsClassProperty) const {
+    return lookupMethod(Sel, !IsClassProperty/*isInstance*/,
+                        false/*shallowCategoryLookup*/,
+                        true /* followsSuper */,
+                        Cat);
+  }
+
+  SourceLocation getEndOfDefinitionLoc() const {
+    if (!hasDefinition())
+      return getLocation();
+
+    return data().EndLoc;
+  }
+
+  void setEndOfDefinitionLoc(SourceLocation LE) { data().EndLoc = LE; }
+
+  /// Retrieve the starting location of the superclass.
+  SourceLocation getSuperClassLoc() const;
+
+  /// isImplicitInterfaceDecl - check that this is an implicitly declared
+  /// ObjCInterfaceDecl node. This is for legacy objective-c \@implementation
+  /// declaration without an \@interface declaration.
+  bool isImplicitInterfaceDecl() const {
+    return hasDefinition() ? data().Definition->isImplicit() : isImplicit();
+  }
+
+  /// ClassImplementsProtocol - Checks that 'lProto' protocol
+  /// has been implemented in IDecl class, its super class or categories (if
+  /// lookupCategory is true).
+  bool ClassImplementsProtocol(ObjCProtocolDecl *lProto,
+                               bool lookupCategory,
+                               bool RHSIsQualifiedID = false);
+
+  using redecl_range = redeclarable_base::redecl_range;
+  using redecl_iterator = redeclarable_base::redecl_iterator;
+
+  using redeclarable_base::redecls_begin;
+  using redeclarable_base::redecls_end;
+  using redeclarable_base::redecls;
+  using redeclarable_base::getPreviousDecl;
+  using redeclarable_base::getMostRecentDecl;
+  using redeclarable_base::isFirstDecl;
+
+  /// Retrieves the canonical declaration of this Objective-C class.
+  ObjCInterfaceDecl *getCanonicalDecl() override { return getFirstDecl(); }
+  const ObjCInterfaceDecl *getCanonicalDecl() const { return getFirstDecl(); }
+
+  // Low-level accessor
+  const Type *getTypeForDecl() const { return TypeForDecl; }
+  void setTypeForDecl(const Type *TD) const { TypeForDecl = TD; }
+
+  /// Get precomputed ODRHash or add a new one.
+  unsigned getODRHash();
+
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+  static bool classofKind(Kind K) { return K == ObjCInterface; }
+
+private:
+  /// True if a valid hash is stored in ODRHash.
+  bool hasODRHash() const;
+  void setHasODRHash(bool HasHash);
+
+  const ObjCInterfaceDecl *findInterfaceWithDesignatedInitializers() const;
+  bool inheritsDesignatedInitializers() const;
+};
+
+/// ObjCIvarDecl - Represents an ObjC instance variable. In general, ObjC
+/// instance variables are identical to C. The only exception is Objective-C
+/// supports C++ style access control. For example:
+///
+///   \@interface IvarExample : NSObject
+///   {
+///     id defaultToProtected;
+///   \@public:
+///     id canBePublic; // same as C++.
+///   \@protected:
+///     id canBeProtected; // same as C++.
+///   \@package:
+///     id canBePackage; // framework visibility (not available in C++).
+///   }
+///
+class ObjCIvarDecl : public FieldDecl {
+  void anchor() override;
+
+public:
+  enum AccessControl {
+    None, Private, Protected, Public, Package
+  };
+
+private:
+  ObjCIvarDecl(ObjCContainerDecl *DC, SourceLocation StartLoc,
+               SourceLocation IdLoc, IdentifierInfo *Id,
+               QualType T, TypeSourceInfo *TInfo, AccessControl ac, Expr *BW,
+               bool synthesized)
+      : FieldDecl(ObjCIvar, DC, StartLoc, IdLoc, Id, T, TInfo, BW,
+                  /*Mutable=*/false, /*HasInit=*/ICIS_NoInit),
+        DeclAccess(ac), Synthesized(synthesized) {}
+
+public:
+  static ObjCIvarDecl *Create(ASTContext &C, ObjCContainerDecl *DC,
+                              SourceLocation StartLoc, SourceLocation IdLoc,
+                              IdentifierInfo *Id, QualType T,
+                              TypeSourceInfo *TInfo,
+                              AccessControl ac, Expr *BW = nullptr,
+                              bool synthesized=false);
+
+  static ObjCIvarDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+
+  /// Return the class interface that this ivar is logically contained
+  /// in; this is either the interface where the ivar was declared, or the
+  /// interface the ivar is conceptually a part of in the case of synthesized
+  /// ivars.
+  ObjCInterfaceDecl *getContainingInterface();
+  const ObjCInterfaceDecl *getContainingInterface() const {
+    return const_cast<ObjCIvarDecl *>(this)->getContainingInterface();
+  }
+
+  ObjCIvarDecl *getNextIvar() { return NextIvar; }
+  const ObjCIvarDecl *getNextIvar() const { return NextIvar; }
+  void setNextIvar(ObjCIvarDecl *ivar) { NextIvar = ivar; }
+
+  ObjCIvarDecl *getCanonicalDecl() override {
+    return cast<ObjCIvarDecl>(FieldDecl::getCanonicalDecl());
+  }
+  const ObjCIvarDecl *getCanonicalDecl() const {
+    return const_cast<ObjCIvarDecl *>(this)->getCanonicalDecl();
+  }
+
+  void setAccessControl(AccessControl ac) { DeclAccess = ac; }
+
+  AccessControl getAccessControl() const { return AccessControl(DeclAccess); }
+
+  AccessControl getCanonicalAccessControl() const {
+    return DeclAccess == None ? Protected : AccessControl(DeclAccess);
+  }
+
+  void setSynthesize(bool synth) { Synthesized = synth; }
+  bool getSynthesize() const { return Synthesized; }
+
+  /// Retrieve the type of this instance variable when viewed as a member of a
+  /// specific object type.
+  QualType getUsageType(QualType objectType) const;
+
+  // Implement isa/cast/dyncast/etc.
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+  static bool classofKind(Kind K) { return K == ObjCIvar; }
+
+private:
+  /// NextIvar - Next Ivar in the list of ivars declared in class; class's
+  /// extensions and class's implementation
+  ObjCIvarDecl *NextIvar = nullptr;
+
+  // NOTE: VC++ treats enums as signed, avoid using the AccessControl enum
+  unsigned DeclAccess : 3;
+  unsigned Synthesized : 1;
+};
+
+/// Represents a field declaration created by an \@defs(...).
+class ObjCAtDefsFieldDecl : public FieldDecl {
+  ObjCAtDefsFieldDecl(DeclContext *DC, SourceLocation StartLoc,
+                      SourceLocation IdLoc, IdentifierInfo *Id,
+                      QualType T, Expr *BW)
+      : FieldDecl(ObjCAtDefsField, DC, StartLoc, IdLoc, Id, T,
+                  /*TInfo=*/nullptr, // FIXME: Do ObjCAtDefs have declarators ?
+                  BW, /*Mutable=*/false, /*HasInit=*/ICIS_NoInit) {}
+
+  void anchor() override;
+
+public:
+  static ObjCAtDefsFieldDecl *Create(ASTContext &C, DeclContext *DC,
+                                     SourceLocation StartLoc,
+                                     SourceLocation IdLoc, IdentifierInfo *Id,
+                                     QualType T, Expr *BW);
+
+  static ObjCAtDefsFieldDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+
+  // Implement isa/cast/dyncast/etc.
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+  static bool classofKind(Kind K) { return K == ObjCAtDefsField; }
+};
+
+/// Represents an Objective-C protocol declaration.
+///
+/// Objective-C protocols declare a pure abstract type (i.e., no instance
+/// variables are permitted).  Protocols originally drew inspiration from
+/// C++ pure virtual functions (a C++ feature with nice semantics and lousy
+/// syntax:-). Here is an example:
+///
+/// \code
+/// \@protocol NSDraggingInfo <refproto1, refproto2>
+/// - (NSWindow *)draggingDestinationWindow;
+/// - (NSImage *)draggedImage;
+/// \@end
+/// \endcode
+///
+/// This says that NSDraggingInfo requires two methods and requires everything
+/// that the two "referenced protocols" 'refproto1' and 'refproto2' require as
+/// well.
+///
+/// \code
+/// \@interface ImplementsNSDraggingInfo : NSObject \<NSDraggingInfo>
+/// \@end
+/// \endcode
+///
+/// ObjC protocols inspired Java interfaces. Unlike Java, ObjC classes and
+/// protocols are in distinct namespaces. For example, Cocoa defines both
+/// an NSObject protocol and class (which isn't allowed in Java). As a result,
+/// protocols are referenced using angle brackets as follows:
+///
+/// id \<NSDraggingInfo> anyObjectThatImplementsNSDraggingInfo;
+class ObjCProtocolDecl : public ObjCContainerDecl,
+                         public Redeclarable<ObjCProtocolDecl> {
+  struct DefinitionData {
+    // The declaration that defines this protocol.
+    ObjCProtocolDecl *Definition;
+
+    /// Referenced protocols
+    ObjCProtocolList ReferencedProtocols;
+
+    /// Tracks whether a ODR hash has been computed for this protocol.
+    unsigned HasODRHash : 1;
+
+    /// A hash of parts of the class to help in ODR checking.
+    unsigned ODRHash = 0;
+  };
+
+  /// Contains a pointer to the data associated with this class,
+  /// which will be NULL if this class has not yet been defined.
+  ///
+  /// The bit indicates when we don't need to check for out-of-date
+  /// declarations. It will be set unless modules are enabled.
+  llvm::PointerIntPair<DefinitionData *, 1, bool> Data;
+
+  ObjCProtocolDecl(ASTContext &C, DeclContext *DC, IdentifierInfo *Id,
+                   SourceLocation nameLoc, SourceLocation atStartLoc,
+                   ObjCProtocolDecl *PrevDecl);
+
+  void anchor() override;
+
+  DefinitionData &data() const {
+    assert(Data.getPointer() && "Objective-C protocol has no definition!");
+    return *Data.getPointer();
+  }
+
+  void allocateDefinitionData();
+
+  using redeclarable_base = Redeclarable<ObjCProtocolDecl>;
+
+  ObjCProtocolDecl *getNextRedeclarationImpl() override {
+    return getNextRedeclaration();
+  }
+
+  ObjCProtocolDecl *getPreviousDeclImpl() override {
+    return getPreviousDecl();
+  }
+
+  ObjCProtocolDecl *getMostRecentDeclImpl() override {
+    return getMostRecentDecl();
+  }
+
+  /// True if a valid hash is stored in ODRHash.
+  bool hasODRHash() const;
+  void setHasODRHash(bool HasHash);
+
+public:
+  friend class ASTDeclReader;
+  friend class ASTDeclWriter;
+  friend class ASTReader;
+  friend class ODRDiagsEmitter;
+
+  static ObjCProtocolDecl *Create(ASTContext &C, DeclContext *DC,
+                                  IdentifierInfo *Id,
+                                  SourceLocation nameLoc,
+                                  SourceLocation atStartLoc,
+                                  ObjCProtocolDecl *PrevDecl);
+
+  static ObjCProtocolDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+
+  const ObjCProtocolList &getReferencedProtocols() const {
+    assert(hasDefinition() && "No definition available!");
+    return data().ReferencedProtocols;
+  }
+
+  using protocol_iterator = ObjCProtocolList::iterator;
+  using protocol_range = llvm::iterator_range<protocol_iterator>;
+
+  protocol_range protocols() const {
+    return protocol_range(protocol_begin(), protocol_end());
+  }
+
+  protocol_iterator protocol_begin() const {
+    if (!hasDefinition())
+      return protocol_iterator();
+
+    return data().ReferencedProtocols.begin();
+  }
+
+  protocol_iterator protocol_end() const {
+    if (!hasDefinition())
+      return protocol_iterator();
+
+    return data().ReferencedProtocols.end();
+  }
+
+  using protocol_loc_iterator = ObjCProtocolList::loc_iterator;
+  using protocol_loc_range = llvm::iterator_range<protocol_loc_iterator>;
+
+  protocol_loc_range protocol_locs() const {
+    return protocol_loc_range(protocol_loc_begin(), protocol_loc_end());
+  }
+
+  protocol_loc_iterator protocol_loc_begin() const {
+    if (!hasDefinition())
+      return protocol_loc_iterator();
+
+    return data().ReferencedProtocols.loc_begin();
+  }
+
+  protocol_loc_iterator protocol_loc_end() const {
+    if (!hasDefinition())
+      return protocol_loc_iterator();
+
+    return data().ReferencedProtocols.loc_end();
+  }
+
+  unsigned protocol_size() const {
+    if (!hasDefinition())
+      return 0;
+
+    return data().ReferencedProtocols.size();
+  }
+
+  /// setProtocolList - Set the list of protocols that this interface
+  /// implements.
+  void setProtocolList(ObjCProtocolDecl *const*List, unsigned Num,
+                       const SourceLocation *Locs, ASTContext &C) {
+    assert(hasDefinition() && "Protocol is not defined");
+    data().ReferencedProtocols.set(List, Num, Locs, C);
+  }
+
+  /// This is true iff the protocol is tagged with the
+  /// `objc_non_runtime_protocol` attribute.
+  bool isNonRuntimeProtocol() const;
+
+  /// Get the set of all protocols implied by this protocols inheritance
+  /// hierarchy.
+  void getImpliedProtocols(llvm::DenseSet<const ObjCProtocolDecl *> &IPs) const;
+
+  ObjCProtocolDecl *lookupProtocolNamed(IdentifierInfo *PName);
+
+  // Lookup a method. First, we search locally. If a method isn't
+  // found, we search referenced protocols and class categories.
+  ObjCMethodDecl *lookupMethod(Selector Sel, bool isInstance) const;
+
+  ObjCMethodDecl *lookupInstanceMethod(Selector Sel) const {
+    return lookupMethod(Sel, true/*isInstance*/);
+  }
+
+  ObjCMethodDecl *lookupClassMethod(Selector Sel) const {
+    return lookupMethod(Sel, false/*isInstance*/);
+  }
+
+  /// Determine whether this protocol has a definition.
+  bool hasDefinition() const {
+    // If the name of this protocol is out-of-date, bring it up-to-date, which
+    // might bring in a definition.
+    // Note: a null value indicates that we don't have a definition and that
+    // modules are enabled.
+    if (!Data.getOpaqueValue())
+      getMostRecentDecl();
+
+    return Data.getPointer();
+  }
+
+  /// Retrieve the definition of this protocol, if any.
+  ObjCProtocolDecl *getDefinition() {
+    return hasDefinition()? Data.getPointer()->Definition : nullptr;
+  }
+
+  /// Retrieve the definition of this protocol, if any.
+  const ObjCProtocolDecl *getDefinition() const {
+    return hasDefinition()? Data.getPointer()->Definition : nullptr;
+  }
+
+  /// Determine whether this particular declaration is also the
+  /// definition.
+  bool isThisDeclarationADefinition() const {
+    return getDefinition() == this;
+  }
+
+  /// Starts the definition of this Objective-C protocol.
+  void startDefinition();
+
+  /// Starts the definition without sharing it with other redeclarations.
+  /// Such definition shouldn't be used for anything but only to compare if
+  /// a duplicate is compatible with previous definition or if it is
+  /// a distinct duplicate.
+  void startDuplicateDefinitionForComparison();
+  void mergeDuplicateDefinitionWithCommon(const ObjCProtocolDecl *Definition);
+
+  /// Produce a name to be used for protocol's metadata. It comes either via
+  /// objc_runtime_name attribute or protocol name.
+  StringRef getObjCRuntimeNameAsString() const;
+
+  SourceRange getSourceRange() const override LLVM_READONLY {
+    if (isThisDeclarationADefinition())
+      return ObjCContainerDecl::getSourceRange();
+
+    return SourceRange(getAtStartLoc(), getLocation());
+  }
+
+  using redecl_range = redeclarable_base::redecl_range;
+  using redecl_iterator = redeclarable_base::redecl_iterator;
+
+  using redeclarable_base::redecls_begin;
+  using redeclarable_base::redecls_end;
+  using redeclarable_base::redecls;
+  using redeclarable_base::getPreviousDecl;
+  using redeclarable_base::getMostRecentDecl;
+  using redeclarable_base::isFirstDecl;
+
+  /// Retrieves the canonical declaration of this Objective-C protocol.
+  ObjCProtocolDecl *getCanonicalDecl() override { return getFirstDecl(); }
+  const ObjCProtocolDecl *getCanonicalDecl() const { return getFirstDecl(); }
+
+  void collectPropertiesToImplement(PropertyMap &PM) const override;
+
+  void collectInheritedProtocolProperties(const ObjCPropertyDecl *Property,
+                                          ProtocolPropertySet &PS,
+                                          PropertyDeclOrder &PO) const;
+
+  /// Get precomputed ODRHash or add a new one.
+  unsigned getODRHash();
+
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+  static bool classofKind(Kind K) { return K == ObjCProtocol; }
+};
+
+/// ObjCCategoryDecl - Represents a category declaration. A category allows
+/// you to add methods to an existing class (without subclassing or modifying
+/// the original class interface or implementation:-). Categories don't allow
+/// you to add instance data. The following example adds "myMethod" to all
+/// NSView's within a process:
+///
+/// \@interface NSView (MyViewMethods)
+/// - myMethod;
+/// \@end
+///
+/// Categories also allow you to split the implementation of a class across
+/// several files (a feature more naturally supported in C++).
+///
+/// Categories were originally inspired by dynamic languages such as Common
+/// Lisp and Smalltalk.  More traditional class-based languages (C++, Java)
+/// don't support this level of dynamism, which is both powerful and dangerous.
+class ObjCCategoryDecl : public ObjCContainerDecl {
+  /// Interface belonging to this category
+  ObjCInterfaceDecl *ClassInterface;
+
+  /// The type parameters associated with this category, if any.
+  ObjCTypeParamList *TypeParamList = nullptr;
+
+  /// referenced protocols in this category.
+  ObjCProtocolList ReferencedProtocols;
+
+  /// Next category belonging to this class.
+  /// FIXME: this should not be a singly-linked list.  Move storage elsewhere.
+  ObjCCategoryDecl *NextClassCategory = nullptr;
+
+  /// The location of the category name in this declaration.
+  SourceLocation CategoryNameLoc;
+
+  /// class extension may have private ivars.
+  SourceLocation IvarLBraceLoc;
+  SourceLocation IvarRBraceLoc;
+
+  ObjCCategoryDecl(DeclContext *DC, SourceLocation AtLoc,
+                   SourceLocation ClassNameLoc, SourceLocation CategoryNameLoc,
+                   IdentifierInfo *Id, ObjCInterfaceDecl *IDecl,
+                   ObjCTypeParamList *typeParamList,
+                   SourceLocation IvarLBraceLoc = SourceLocation(),
+                   SourceLocation IvarRBraceLoc = SourceLocation());
+
+  void anchor() override;
+
+public:
+  friend class ASTDeclReader;
+  friend class ASTDeclWriter;
+
+  static ObjCCategoryDecl *Create(ASTContext &C, DeclContext *DC,
+                                  SourceLocation AtLoc,
+                                  SourceLocation ClassNameLoc,
+                                  SourceLocation CategoryNameLoc,
+                                  IdentifierInfo *Id,
+                                  ObjCInterfaceDecl *IDecl,
+                                  ObjCTypeParamList *typeParamList,
+                                  SourceLocation IvarLBraceLoc=SourceLocation(),
+                                  SourceLocation IvarRBraceLoc=SourceLocation());
+  static ObjCCategoryDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+
+  ObjCInterfaceDecl *getClassInterface() { return ClassInterface; }
+  const ObjCInterfaceDecl *getClassInterface() const { return ClassInterface; }
+
+  /// Retrieve the type parameter list associated with this category or
+  /// extension.
+  ObjCTypeParamList *getTypeParamList() const { return TypeParamList; }
+
+  /// Set the type parameters of this category.
+  ///
+  /// This function is used by the AST importer, which must import the type
+  /// parameters after creating their DeclContext to avoid loops.
+  void setTypeParamList(ObjCTypeParamList *TPL);
+
+
+  ObjCCategoryImplDecl *getImplementation() const;
+  void setImplementation(ObjCCategoryImplDecl *ImplD);
+
+  /// setProtocolList - Set the list of protocols that this interface
+  /// implements.
+  void setProtocolList(ObjCProtocolDecl *const*List, unsigned Num,
+                       const SourceLocation *Locs, ASTContext &C) {
+    ReferencedProtocols.set(List, Num, Locs, C);
+  }
+
+  const ObjCProtocolList &getReferencedProtocols() const {
+    return ReferencedProtocols;
+  }
+
+  using protocol_iterator = ObjCProtocolList::iterator;
+  using protocol_range = llvm::iterator_range<protocol_iterator>;
+
+  protocol_range protocols() const {
+    return protocol_range(protocol_begin(), protocol_end());
+  }
+
+  protocol_iterator protocol_begin() const {
+    return ReferencedProtocols.begin();
+  }
+
+  protocol_iterator protocol_end() const { return ReferencedProtocols.end(); }
+  unsigned protocol_size() const { return ReferencedProtocols.size(); }
+
+  using protocol_loc_iterator = ObjCProtocolList::loc_iterator;
+  using protocol_loc_range = llvm::iterator_range<protocol_loc_iterator>;
+
+  protocol_loc_range protocol_locs() const {
+    return protocol_loc_range(protocol_loc_begin(), protocol_loc_end());
+  }
+
+  protocol_loc_iterator protocol_loc_begin() const {
+    return ReferencedProtocols.loc_begin();
+  }
+
+  protocol_loc_iterator protocol_loc_end() const {
+    return ReferencedProtocols.loc_end();
+  }
+
+  ObjCCategoryDecl *getNextClassCategory() const { return NextClassCategory; }
+
+  /// Retrieve the pointer to the next stored category (or extension),
+  /// which may be hidden.
+  ObjCCategoryDecl *getNextClassCategoryRaw() const {
+    return NextClassCategory;
+  }
+
+  bool IsClassExtension() const { return getIdentifier() == nullptr; }
+
+  using ivar_iterator = specific_decl_iterator<ObjCIvarDecl>;
+  using ivar_range = llvm::iterator_range<specific_decl_iterator<ObjCIvarDecl>>;
+
+  ivar_range ivars() const { return ivar_range(ivar_begin(), ivar_end()); }
+
+  ivar_iterator ivar_begin() const {
+    return ivar_iterator(decls_begin());
+  }
+
+  ivar_iterator ivar_end() const {
+    return ivar_iterator(decls_end());
+  }
+
+  unsigned ivar_size() const {
+    return std::distance(ivar_begin(), ivar_end());
+  }
+
+  bool ivar_empty() const {
+    return ivar_begin() == ivar_end();
+  }
+
+  SourceLocation getCategoryNameLoc() const { return CategoryNameLoc; }
+  void setCategoryNameLoc(SourceLocation Loc) { CategoryNameLoc = Loc; }
+
+  void setIvarLBraceLoc(SourceLocation Loc) { IvarLBraceLoc = Loc; }
+  SourceLocation getIvarLBraceLoc() const { return IvarLBraceLoc; }
+  void setIvarRBraceLoc(SourceLocation Loc) { IvarRBraceLoc = Loc; }
+  SourceLocation getIvarRBraceLoc() const { return IvarRBraceLoc; }
+
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+  static bool classofKind(Kind K) { return K == ObjCCategory; }
+};
+
+class ObjCImplDecl : public ObjCContainerDecl {
+  /// Class interface for this class/category implementation
+  ObjCInterfaceDecl *ClassInterface;
+
+  void anchor() override;
+
+protected:
+  ObjCImplDecl(Kind DK, DeclContext *DC,
+               ObjCInterfaceDecl *classInterface,
+               IdentifierInfo *Id,
+               SourceLocation nameLoc, SourceLocation atStartLoc)
+      : ObjCContainerDecl(DK, DC, Id, nameLoc, atStartLoc),
+        ClassInterface(classInterface) {}
+
+public:
+  const ObjCInterfaceDecl *getClassInterface() const { return ClassInterface; }
+  ObjCInterfaceDecl *getClassInterface() { return ClassInterface; }
+  void setClassInterface(ObjCInterfaceDecl *IFace);
+
+  void addInstanceMethod(ObjCMethodDecl *method) {
+    // FIXME: Context should be set correctly before we get here.
+    method->setLexicalDeclContext(this);
+    addDecl(method);
+  }
+
+  void addClassMethod(ObjCMethodDecl *method) {
+    // FIXME: Context should be set correctly before we get here.
+    method->setLexicalDeclContext(this);
+    addDecl(method);
+  }
+
+  void addPropertyImplementation(ObjCPropertyImplDecl *property);
+
+  ObjCPropertyImplDecl *FindPropertyImplDecl(IdentifierInfo *propertyId,
+                            ObjCPropertyQueryKind queryKind) const;
+  ObjCPropertyImplDecl *FindPropertyImplIvarDecl(IdentifierInfo *ivarId) const;
+
+  // Iterator access to properties.
+  using propimpl_iterator = specific_decl_iterator<ObjCPropertyImplDecl>;
+  using propimpl_range =
+      llvm::iterator_range<specific_decl_iterator<ObjCPropertyImplDecl>>;
+
+  propimpl_range property_impls() const {
+    return propimpl_range(propimpl_begin(), propimpl_end());
+  }
+
+  propimpl_iterator propimpl_begin() const {
+    return propimpl_iterator(decls_begin());
+  }
+
+  propimpl_iterator propimpl_end() const {
+    return propimpl_iterator(decls_end());
+  }
+
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+
+  static bool classofKind(Kind K) {
+    return K >= firstObjCImpl && K <= lastObjCImpl;
+  }
+};
+
+/// ObjCCategoryImplDecl - An object of this class encapsulates a category
+/// \@implementation declaration. If a category class has declaration of a
+/// property, its implementation must be specified in the category's
+/// \@implementation declaration. Example:
+/// \@interface I \@end
+/// \@interface I(CATEGORY)
+///    \@property int p1, d1;
+/// \@end
+/// \@implementation I(CATEGORY)
+///  \@dynamic p1,d1;
+/// \@end
+///
+/// ObjCCategoryImplDecl
+class ObjCCategoryImplDecl : public ObjCImplDecl {
+  // Category name location
+  SourceLocation CategoryNameLoc;
+
+  ObjCCategoryImplDecl(DeclContext *DC, IdentifierInfo *Id,
+                       ObjCInterfaceDecl *classInterface,
+                       SourceLocation nameLoc, SourceLocation atStartLoc,
+                       SourceLocation CategoryNameLoc)
+      : ObjCImplDecl(ObjCCategoryImpl, DC, classInterface, Id,
+                     nameLoc, atStartLoc),
+        CategoryNameLoc(CategoryNameLoc) {}
+
+  void anchor() override;
+
+public:
+  friend class ASTDeclReader;
+  friend class ASTDeclWriter;
+
+  static ObjCCategoryImplDecl *Create(ASTContext &C, DeclContext *DC,
+                                      IdentifierInfo *Id,
+                                      ObjCInterfaceDecl *classInterface,
+                                      SourceLocation nameLoc,
+                                      SourceLocation atStartLoc,
+                                      SourceLocation CategoryNameLoc);
+  static ObjCCategoryImplDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+
+  ObjCCategoryDecl *getCategoryDecl() const;
+
+  SourceLocation getCategoryNameLoc() const { return CategoryNameLoc; }
+
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+  static bool classofKind(Kind K) { return K == ObjCCategoryImpl;}
+};
+
+raw_ostream &operator<<(raw_ostream &OS, const ObjCCategoryImplDecl &CID);
+
+/// ObjCImplementationDecl - Represents a class definition - this is where
+/// method definitions are specified. For example:
+///
+/// @code
+/// \@implementation MyClass
+/// - (void)myMethod { /* do something */ }
+/// \@end
+/// @endcode
+///
+/// In a non-fragile runtime, instance variables can appear in the class
+/// interface, class extensions (nameless categories), and in the implementation
+/// itself, as well as being synthesized as backing storage for properties.
+///
+/// In a fragile runtime, instance variables are specified in the class
+/// interface, \em not in the implementation. Nevertheless (for legacy reasons),
+/// we allow instance variables to be specified in the implementation. When
+/// specified, they need to be \em identical to the interface.
+class ObjCImplementationDecl : public ObjCImplDecl {
+  /// Implementation Class's super class.
+  ObjCInterfaceDecl *SuperClass;
+  SourceLocation SuperLoc;
+
+  /// \@implementation may have private ivars.
+  SourceLocation IvarLBraceLoc;
+  SourceLocation IvarRBraceLoc;
+
+  /// Support for ivar initialization.
+  /// The arguments used to initialize the ivars
+  LazyCXXCtorInitializersPtr IvarInitializers;
+  unsigned NumIvarInitializers = 0;
+
+  /// Do the ivars of this class require initialization other than
+  /// zero-initialization?
+  bool HasNonZeroConstructors : 1;
+
+  /// Do the ivars of this class require non-trivial destruction?
+  bool HasDestructors : 1;
+
+  ObjCImplementationDecl(DeclContext *DC,
+                         ObjCInterfaceDecl *classInterface,
+                         ObjCInterfaceDecl *superDecl,
+                         SourceLocation nameLoc, SourceLocation atStartLoc,
+                         SourceLocation superLoc = SourceLocation(),
+                         SourceLocation IvarLBraceLoc=SourceLocation(),
+                         SourceLocation IvarRBraceLoc=SourceLocation())
+      : ObjCImplDecl(ObjCImplementation, DC, classInterface,
+                     classInterface ? classInterface->getIdentifier()
+                                    : nullptr,
+                     nameLoc, atStartLoc),
+         SuperClass(superDecl), SuperLoc(superLoc),
+         IvarLBraceLoc(IvarLBraceLoc), IvarRBraceLoc(IvarRBraceLoc),
+         HasNonZeroConstructors(false), HasDestructors(false) {}
+
+  void anchor() override;
+
+public:
+  friend class ASTDeclReader;
+  friend class ASTDeclWriter;
+
+  static ObjCImplementationDecl *Create(ASTContext &C, DeclContext *DC,
+                                        ObjCInterfaceDecl *classInterface,
+                                        ObjCInterfaceDecl *superDecl,
+                                        SourceLocation nameLoc,
+                                        SourceLocation atStartLoc,
+                                     SourceLocation superLoc = SourceLocation(),
+                                        SourceLocation IvarLBraceLoc=SourceLocation(),
+                                        SourceLocation IvarRBraceLoc=SourceLocation());
+
+  static ObjCImplementationDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+
+  /// init_iterator - Iterates through the ivar initializer list.
+  using init_iterator = CXXCtorInitializer **;
+
+  /// init_const_iterator - Iterates through the ivar initializer list.
+  using init_const_iterator = CXXCtorInitializer * const *;
+
+  using init_range = llvm::iterator_range<init_iterator>;
+  using init_const_range = llvm::iterator_range<init_const_iterator>;
+
+  init_range inits() { return init_range(init_begin(), init_end()); }
+
+  init_const_range inits() const {
+    return init_const_range(init_begin(), init_end());
+  }
+
+  /// init_begin() - Retrieve an iterator to the first initializer.
+  init_iterator init_begin() {
+    const auto *ConstThis = this;
+    return const_cast<init_iterator>(ConstThis->init_begin());
+  }
+
+  /// begin() - Retrieve an iterator to the first initializer.
+  init_const_iterator init_begin() const;
+
+  /// init_end() - Retrieve an iterator past the last initializer.
+  init_iterator       init_end()       {
+    return init_begin() + NumIvarInitializers;
+  }
+
+  /// end() - Retrieve an iterator past the last initializer.
+  init_const_iterator init_end() const {
+    return init_begin() + NumIvarInitializers;
+  }
+
+  /// getNumArgs - Number of ivars which must be initialized.
+  unsigned getNumIvarInitializers() const {
+    return NumIvarInitializers;
+  }
+
+  void setNumIvarInitializers(unsigned numNumIvarInitializers) {
+    NumIvarInitializers = numNumIvarInitializers;
+  }
+
+  void setIvarInitializers(ASTContext &C,
+                           CXXCtorInitializer ** initializers,
+                           unsigned numInitializers);
+
+  /// Do any of the ivars of this class (not counting its base classes)
+  /// require construction other than zero-initialization?
+  bool hasNonZeroConstructors() const { return HasNonZeroConstructors; }
+  void setHasNonZeroConstructors(bool val) { HasNonZeroConstructors = val; }
+
+  /// Do any of the ivars of this class (not counting its base classes)
+  /// require non-trivial destruction?
+  bool hasDestructors() const { return HasDestructors; }
+  void setHasDestructors(bool val) { HasDestructors = val; }
+
+  /// getIdentifier - Get the identifier that names the class
+  /// interface associated with this implementation.
+  IdentifierInfo *getIdentifier() const {
+    return getClassInterface()->getIdentifier();
+  }
+
+  /// getName - Get the name of identifier for the class interface associated
+  /// with this implementation as a StringRef.
+  //
+  // FIXME: This is a bad API, we are hiding NamedDecl::getName with a different
+  // meaning.
+  StringRef getName() const {
+    assert(getIdentifier() && "Name is not a simple identifier");
+    return getIdentifier()->getName();
+  }
+
+  /// Get the name of the class associated with this interface.
+  //
+  // FIXME: Move to StringRef API.
+  std::string getNameAsString() const { return std::string(getName()); }
+
+  /// Produce a name to be used for class's metadata. It comes either via
+  /// class's objc_runtime_name attribute or class name.
+  StringRef getObjCRuntimeNameAsString() const;
+
+  const ObjCInterfaceDecl *getSuperClass() const { return SuperClass; }
+  ObjCInterfaceDecl *getSuperClass() { return SuperClass; }
+  SourceLocation getSuperClassLoc() const { return SuperLoc; }
+
+  void setSuperClass(ObjCInterfaceDecl * superCls) { SuperClass = superCls; }
+
+  void setIvarLBraceLoc(SourceLocation Loc) { IvarLBraceLoc = Loc; }
+  SourceLocation getIvarLBraceLoc() const { return IvarLBraceLoc; }
+  void setIvarRBraceLoc(SourceLocation Loc) { IvarRBraceLoc = Loc; }
+  SourceLocation getIvarRBraceLoc() const { return IvarRBraceLoc; }
+
+  using ivar_iterator = specific_decl_iterator<ObjCIvarDecl>;
+  using ivar_range = llvm::iterator_range<specific_decl_iterator<ObjCIvarDecl>>;
+
+  ivar_range ivars() const { return ivar_range(ivar_begin(), ivar_end()); }
+
+  ivar_iterator ivar_begin() const {
+    return ivar_iterator(decls_begin());
+  }
+
+  ivar_iterator ivar_end() const {
+    return ivar_iterator(decls_end());
+  }
+
+  unsigned ivar_size() const {
+    return std::distance(ivar_begin(), ivar_end());
+  }
+
+  bool ivar_empty() const {
+    return ivar_begin() == ivar_end();
+  }
+
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+  static bool classofKind(Kind K) { return K == ObjCImplementation; }
+};
+
+raw_ostream &operator<<(raw_ostream &OS, const ObjCImplementationDecl &ID);
+
+/// ObjCCompatibleAliasDecl - Represents alias of a class. This alias is
+/// declared as \@compatibility_alias alias class.
+class ObjCCompatibleAliasDecl : public NamedDecl {
+  /// Class that this is an alias of.
+  ObjCInterfaceDecl *AliasedClass;
+
+  ObjCCompatibleAliasDecl(DeclContext *DC, SourceLocation L, IdentifierInfo *Id,
+                          ObjCInterfaceDecl* aliasedClass)
+      : NamedDecl(ObjCCompatibleAlias, DC, L, Id), AliasedClass(aliasedClass) {}
+
+  void anchor() override;
+
+public:
+  static ObjCCompatibleAliasDecl *Create(ASTContext &C, DeclContext *DC,
+                                         SourceLocation L, IdentifierInfo *Id,
+                                         ObjCInterfaceDecl* aliasedClass);
+
+  static ObjCCompatibleAliasDecl *CreateDeserialized(ASTContext &C,
+                                                     unsigned ID);
+
+  const ObjCInterfaceDecl *getClassInterface() const { return AliasedClass; }
+  ObjCInterfaceDecl *getClassInterface() { return AliasedClass; }
+  void setClassInterface(ObjCInterfaceDecl *D) { AliasedClass = D; }
+
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+  static bool classofKind(Kind K) { return K == ObjCCompatibleAlias; }
+};
+
+/// ObjCPropertyImplDecl - Represents implementation declaration of a property
+/// in a class or category implementation block. For example:
+/// \@synthesize prop1 = ivar1;
+///
+class ObjCPropertyImplDecl : public Decl {
+public:
+  enum Kind {
+    Synthesize,
+    Dynamic
+  };
+
+private:
+  SourceLocation AtLoc;   // location of \@synthesize or \@dynamic
+
+  /// For \@synthesize, the location of the ivar, if it was written in
+  /// the source code.
+  ///
+  /// \code
+  /// \@synthesize int a = b
+  /// \endcode
+  SourceLocation IvarLoc;
+
+  /// Property declaration being implemented
+  ObjCPropertyDecl *PropertyDecl;
+
+  /// Null for \@dynamic. Required for \@synthesize.
+  ObjCIvarDecl *PropertyIvarDecl;
+
+  /// The getter's definition, which has an empty body if synthesized.
+  ObjCMethodDecl *GetterMethodDecl = nullptr;
+  /// The getter's definition, which has an empty body if synthesized.
+  ObjCMethodDecl *SetterMethodDecl = nullptr;
+
+  /// Null for \@dynamic. Non-null if property must be copy-constructed in
+  /// getter.
+  Expr *GetterCXXConstructor = nullptr;
+
+  /// Null for \@dynamic. Non-null if property has assignment operator to call
+  /// in Setter synthesis.
+  Expr *SetterCXXAssignment = nullptr;
+
+  ObjCPropertyImplDecl(DeclContext *DC, SourceLocation atLoc, SourceLocation L,
+                       ObjCPropertyDecl *property,
+                       Kind PK,
+                       ObjCIvarDecl *ivarDecl,
+                       SourceLocation ivarLoc)
+      : Decl(ObjCPropertyImpl, DC, L), AtLoc(atLoc),
+        IvarLoc(ivarLoc), PropertyDecl(property), PropertyIvarDecl(ivarDecl) {
+    assert(PK == Dynamic || PropertyIvarDecl);
+  }
+
+public:
+  friend class ASTDeclReader;
+
+  static ObjCPropertyImplDecl *Create(ASTContext &C, DeclContext *DC,
+                                      SourceLocation atLoc, SourceLocation L,
+                                      ObjCPropertyDecl *property,
+                                      Kind PK,
+                                      ObjCIvarDecl *ivarDecl,
+                                      SourceLocation ivarLoc);
+
+  static ObjCPropertyImplDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+
+  SourceRange getSourceRange() const override LLVM_READONLY;
+
+  SourceLocation getBeginLoc() const LLVM_READONLY { return AtLoc; }
+  void setAtLoc(SourceLocation Loc) { AtLoc = Loc; }
+
+  ObjCPropertyDecl *getPropertyDecl() const {
+    return PropertyDecl;
+  }
+  void setPropertyDecl(ObjCPropertyDecl *Prop) { PropertyDecl = Prop; }
+
+  Kind getPropertyImplementation() const {
+    return PropertyIvarDecl ? Synthesize : Dynamic;
+  }
+
+  ObjCIvarDecl *getPropertyIvarDecl() const {
+    return PropertyIvarDecl;
+  }
+  SourceLocation getPropertyIvarDeclLoc() const { return IvarLoc; }
+
+  void setPropertyIvarDecl(ObjCIvarDecl *Ivar,
+                           SourceLocation IvarLoc) {
+    PropertyIvarDecl = Ivar;
+    this->IvarLoc = IvarLoc;
+  }
+
+  /// For \@synthesize, returns true if an ivar name was explicitly
+  /// specified.
+  ///
+  /// \code
+  /// \@synthesize int a = b; // true
+  /// \@synthesize int a; // false
+  /// \endcode
+  bool isIvarNameSpecified() const {
+    return IvarLoc.isValid() && IvarLoc != getLocation();
+  }
+
+  ObjCMethodDecl *getGetterMethodDecl() const { return GetterMethodDecl; }
+  void setGetterMethodDecl(ObjCMethodDecl *MD) { GetterMethodDecl = MD; }
+
+  ObjCMethodDecl *getSetterMethodDecl() const { return SetterMethodDecl; }
+  void setSetterMethodDecl(ObjCMethodDecl *MD) { SetterMethodDecl = MD; }
+
+  Expr *getGetterCXXConstructor() const {
+    return GetterCXXConstructor;
+  }
+
+  void setGetterCXXConstructor(Expr *getterCXXConstructor) {
+    GetterCXXConstructor = getterCXXConstructor;
+  }
+
+  Expr *getSetterCXXAssignment() const {
+    return SetterCXXAssignment;
+  }
+
+  void setSetterCXXAssignment(Expr *setterCXXAssignment) {
+    SetterCXXAssignment = setterCXXAssignment;
+  }
+
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+  static bool classofKind(Decl::Kind K) { return K == ObjCPropertyImpl; }
+};
+
+template<bool (*Filter)(ObjCCategoryDecl *)>
+void
+ObjCInterfaceDecl::filtered_category_iterator<Filter>::
+findAcceptableCategory() {
+  while (Current && !Filter(Current))
+    Current = Current->getNextClassCategoryRaw();
+}
+
+template<bool (*Filter)(ObjCCategoryDecl *)>
+inline ObjCInterfaceDecl::filtered_category_iterator<Filter> &
+ObjCInterfaceDecl::filtered_category_iterator<Filter>::operator++() {
+  Current = Current->getNextClassCategoryRaw();
+  findAcceptableCategory();
+  return *this;
+}
+
+inline bool ObjCInterfaceDecl::isVisibleCategory(ObjCCategoryDecl *Cat) {
+  return !Cat->isInvalidDecl() && Cat->isUnconditionallyVisible();
+}
+
+inline bool ObjCInterfaceDecl::isVisibleExtension(ObjCCategoryDecl *Cat) {
+  return !Cat->isInvalidDecl() && Cat->IsClassExtension() &&
+         Cat->isUnconditionallyVisible();
+}
+
+inline bool ObjCInterfaceDecl::isKnownExtension(ObjCCategoryDecl *Cat) {
+  return !Cat->isInvalidDecl() && Cat->IsClassExtension();
+}
+
+} // namespace clang
+
+#endif // LLVM_CLANG_AST_DECLOBJC_H
+
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif