text: //===--- SemaObjCProperty.cpp - Semantic Analysis for ObjC @property ------===//
  //
  // 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 implements semantic analysis for Objective C @property and
  //  @synthesize declarations.
  //
  //===----------------------------------------------------------------------===//
  
  #include "clang/Sema/SemaInternal.h"
  #include "clang/AST/ASTMutationListener.h"
  #include "clang/AST/DeclObjC.h"
  #include "clang/AST/ExprCXX.h"
  #include "clang/AST/ExprObjC.h"
  #include "clang/Basic/SourceManager.h"
  #include "clang/Lex/Lexer.h"
  #include "clang/Lex/Preprocessor.h"
  #include "clang/Sema/Initialization.h"
  #include "llvm/ADT/DenseSet.h"
  #include "llvm/ADT/SmallString.h"
  
  using namespace clang;
  
  //===----------------------------------------------------------------------===//
  // Grammar actions.
  //===----------------------------------------------------------------------===//
  
  /// getImpliedARCOwnership - Given a set of property attributes and a
  /// type, infer an expected lifetime.  The type's ownership qualification
  /// is not considered.
  ///
  /// Returns OCL_None if the attributes as stated do not imply an ownership.
  /// Never returns OCL_Autoreleasing.
  static Qualifiers::ObjCLifetime getImpliedARCOwnership(
                                 ObjCPropertyDecl::PropertyAttributeKind attrs,
                                                  QualType type) {
    // retain, strong, copy, weak, and unsafe_unretained are only legal
    // on properties of retainable pointer type.
    if (attrs & (ObjCPropertyDecl::OBJC_PR_retain |
                 ObjCPropertyDecl::OBJC_PR_strong |
                 ObjCPropertyDecl::OBJC_PR_copy)) {
      return Qualifiers::OCL_Strong;
    } else if (attrs & ObjCPropertyDecl::OBJC_PR_weak) {
      return Qualifiers::OCL_Weak;
    } else if (attrs & ObjCPropertyDecl::OBJC_PR_unsafe_unretained) {
      return Qualifiers::OCL_ExplicitNone;
    }
  
    // assign can appear on other types, so we have to check the
    // property type.
    if (attrs & ObjCPropertyDecl::OBJC_PR_assign &&
        type->isObjCRetainableType()) {
      return Qualifiers::OCL_ExplicitNone;
    }
  
    return Qualifiers::OCL_None;
  }
  
  /// Check the internal consistency of a property declaration with
  /// an explicit ownership qualifier.
  static void checkPropertyDeclWithOwnership(Sema &S,
                                             ObjCPropertyDecl *property) {
    if (property->isInvalidDecl()) return;
  
    ObjCPropertyDecl::PropertyAttributeKind propertyKind
      = property->getPropertyAttributes();
    Qualifiers::ObjCLifetime propertyLifetime
      = property->getType().getObjCLifetime();
  
    assert(propertyLifetime != Qualifiers::OCL_None);
  
    Qualifiers::ObjCLifetime expectedLifetime
      = getImpliedARCOwnership(propertyKind, property->getType());
    if (!expectedLifetime) {
      // We have a lifetime qualifier but no dominating property
      // attribute.  That's okay, but restore reasonable invariants by
      // setting the property attribute according to the lifetime
      // qualifier.
      ObjCPropertyDecl::PropertyAttributeKind attr;
      if (propertyLifetime == Qualifiers::OCL_Strong) {
        attr = ObjCPropertyDecl::OBJC_PR_strong;
      } else if (propertyLifetime == Qualifiers::OCL_Weak) {
        attr = ObjCPropertyDecl::OBJC_PR_weak;
      } else {
        assert(propertyLifetime == Qualifiers::OCL_ExplicitNone);
        attr = ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
      }
      property->setPropertyAttributes(attr);
      return;
    }
  
    if (propertyLifetime == expectedLifetime) return;
  
    property->setInvalidDecl();
    S.Diag(property->getLocation(),
           diag::err_arc_inconsistent_property_ownership)
      << property->getDeclName()
      << expectedLifetime
      << propertyLifetime;
  }
  
  /// Check this Objective-C property against a property declared in the
  /// given protocol.
  static void
  CheckPropertyAgainstProtocol(Sema &S, ObjCPropertyDecl *Prop,
                               ObjCProtocolDecl *Proto,
                               llvm::SmallPtrSetImpl<ObjCProtocolDecl *> &Known) {
    // Have we seen this protocol before?
    if (!Known.insert(Proto).second)
      return;
  
    // Look for a property with the same name.
    DeclContext::lookup_result R = Proto->lookup(Prop->getDeclName());
    for (unsigned I = 0, N = R.size(); I != N; ++I) {
      if (ObjCPropertyDecl *ProtoProp = dyn_cast<ObjCPropertyDecl>(R[I])) {
        S.DiagnosePropertyMismatch(Prop, ProtoProp, Proto->getIdentifier(), true);
        return;
      }
    }
  
    // Check this property against any protocols we inherit.
    for (auto *P : Proto->protocols())
      CheckPropertyAgainstProtocol(S, Prop, P, Known);
  }
  
  static unsigned deducePropertyOwnershipFromType(Sema &S, QualType T) {
    // In GC mode, just look for the __weak qualifier.
    if (S.getLangOpts().getGC() != LangOptions::NonGC) {
      if (T.isObjCGCWeak()) return ObjCDeclSpec::DQ_PR_weak;
  
    // In ARC/MRC, look for an explicit ownership qualifier.
    // For some reason, this only applies to __weak.
    } else if (auto ownership = T.getObjCLifetime()) {
      switch (ownership) {
      case Qualifiers::OCL_Weak:
        return ObjCDeclSpec::DQ_PR_weak;
      case Qualifiers::OCL_Strong:
        return ObjCDeclSpec::DQ_PR_strong;
      case Qualifiers::OCL_ExplicitNone:
        return ObjCDeclSpec::DQ_PR_unsafe_unretained;
      case Qualifiers::OCL_Autoreleasing:
      case Qualifiers::OCL_None:
        return 0;
      }
      llvm_unreachable("bad qualifier");
    }
  
    return 0;
  }
  
  static const unsigned OwnershipMask =
    (ObjCPropertyDecl::OBJC_PR_assign |
     ObjCPropertyDecl::OBJC_PR_retain |
     ObjCPropertyDecl::OBJC_PR_copy   |
     ObjCPropertyDecl::OBJC_PR_weak   |
     ObjCPropertyDecl::OBJC_PR_strong |
     ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
  
  static unsigned getOwnershipRule(unsigned attr) {
    unsigned result = attr & OwnershipMask;
  
    // From an ownership perspective, assign and unsafe_unretained are
    // identical; make sure one also implies the other.
    if (result & (ObjCPropertyDecl::OBJC_PR_assign |
                  ObjCPropertyDecl::OBJC_PR_unsafe_unretained)) {
      result |= ObjCPropertyDecl::OBJC_PR_assign |
                ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
    }
  
    return result;
  }
  
  Decl *Sema::ActOnProperty(Scope *S, SourceLocation AtLoc,
                            SourceLocation LParenLoc,
                            FieldDeclarator &FD,
                            ObjCDeclSpec &ODS,
                            Selector GetterSel,
                            Selector SetterSel,
                            tok::ObjCKeywordKind MethodImplKind,
                            DeclContext *lexicalDC) {
    unsigned Attributes = ODS.getPropertyAttributes();
    FD.D.setObjCWeakProperty((Attributes & ObjCDeclSpec::DQ_PR_weak) != 0);
    TypeSourceInfo *TSI = GetTypeForDeclarator(FD.D, S);
    QualType T = TSI->getType();
    if (!getOwnershipRule(Attributes)) {
      Attributes |= deducePropertyOwnershipFromType(*this, T);
    }
    bool isReadWrite = ((Attributes & ObjCDeclSpec::DQ_PR_readwrite) ||
                        // default is readwrite!
                        !(Attributes & ObjCDeclSpec::DQ_PR_readonly));
  
    // Proceed with constructing the ObjCPropertyDecls.
    ObjCContainerDecl *ClassDecl = cast<ObjCContainerDecl>(CurContext);
    ObjCPropertyDecl *Res = nullptr;
    if (ObjCCategoryDecl *CDecl = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
      if (CDecl->IsClassExtension()) {
        Res = HandlePropertyInClassExtension(S, AtLoc, LParenLoc,
                                             FD,
                                             GetterSel, ODS.getGetterNameLoc(),
                                             SetterSel, ODS.getSetterNameLoc(),
                                             isReadWrite, Attributes,
                                             ODS.getPropertyAttributes(),
                                             T, TSI, MethodImplKind);
        if (!Res)
          return nullptr;
      }
    }
  
    if (!Res) {
      Res = CreatePropertyDecl(S, ClassDecl, AtLoc, LParenLoc, FD,
                               GetterSel, ODS.getGetterNameLoc(), SetterSel,
                               ODS.getSetterNameLoc(), isReadWrite, Attributes,
                               ODS.getPropertyAttributes(), T, TSI,
                               MethodImplKind);
      if (lexicalDC)
        Res->setLexicalDeclContext(lexicalDC);
    }
  
    // Validate the attributes on the @property.
    CheckObjCPropertyAttributes(Res, AtLoc, Attributes,
                                (isa<ObjCInterfaceDecl>(ClassDecl) ||
                                 isa<ObjCProtocolDecl>(ClassDecl)));
  
    // Check consistency if the type has explicit ownership qualification.
    if (Res->getType().getObjCLifetime())
      checkPropertyDeclWithOwnership(*this, Res);
  
    llvm::SmallPtrSet<ObjCProtocolDecl *, 16> KnownProtos;
    if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(ClassDecl)) {
      // For a class, compare the property against a property in our superclass.
      bool FoundInSuper = false;
      ObjCInterfaceDecl *CurrentInterfaceDecl = IFace;
      while (ObjCInterfaceDecl *Super = CurrentInterfaceDecl->getSuperClass()) {
        DeclContext::lookup_result R = Super->lookup(Res->getDeclName());
        for (unsigned I = 0, N = R.size(); I != N; ++I) {
          if (ObjCPropertyDecl *SuperProp = dyn_cast<ObjCPropertyDecl>(R[I])) {
            DiagnosePropertyMismatch(Res, SuperProp, Super->getIdentifier(), false);
            FoundInSuper = true;
            break;
          }
        }
        if (FoundInSuper)
          break;
        else
          CurrentInterfaceDecl = Super;
      }
  
      if (FoundInSuper) {
        // Also compare the property against a property in our protocols.
        for (auto *P : CurrentInterfaceDecl->protocols()) {
          CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
        }
      } else {
        // Slower path: look in all protocols we referenced.
        for (auto *P : IFace->all_referenced_protocols()) {
          CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
        }
      }
    } else if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
      // We don't check if class extension. Because properties in class extension
      // are meant to override some of the attributes and checking has already done
      // when property in class extension is constructed.
      if (!Cat->IsClassExtension())
        for (auto *P : Cat->protocols())
          CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
    } else {
      ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(ClassDecl);
      for (auto *P : Proto->protocols())
        CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
    }
  
    ActOnDocumentableDecl(Res);
    return Res;
  }
  
  static ObjCPropertyDecl::PropertyAttributeKind
  makePropertyAttributesAsWritten(unsigned Attributes) {
    unsigned attributesAsWritten = 0;
    if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
      attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_readonly;
    if (Attributes & ObjCDeclSpec::DQ_PR_readwrite)
      attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_readwrite;
    if (Attributes & ObjCDeclSpec::DQ_PR_getter)
      attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_getter;
    if (Attributes & ObjCDeclSpec::DQ_PR_setter)
      attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_setter;
    if (Attributes & ObjCDeclSpec::DQ_PR_assign)
      attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_assign;
    if (Attributes & ObjCDeclSpec::DQ_PR_retain)
      attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_retain;
    if (Attributes & ObjCDeclSpec::DQ_PR_strong)
      attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_strong;
    if (Attributes & ObjCDeclSpec::DQ_PR_weak)
      attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_weak;
    if (Attributes & ObjCDeclSpec::DQ_PR_copy)
      attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_copy;
    if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
      attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
    if (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)
      attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_nonatomic;
    if (Attributes & ObjCDeclSpec::DQ_PR_atomic)
      attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_atomic;
    if (Attributes & ObjCDeclSpec::DQ_PR_class)
      attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_class;
  
    return (ObjCPropertyDecl::PropertyAttributeKind)attributesAsWritten;
  }
  
  static bool LocPropertyAttribute( ASTContext &Context, const char *attrName,
                                   SourceLocation LParenLoc, SourceLocation &Loc) {
    if (LParenLoc.isMacroID())
      return false;
  
    SourceManager &SM = Context.getSourceManager();
    std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(LParenLoc);
    // Try to load the file buffer.
    bool invalidTemp = false;
    StringRef file = SM.getBufferData(locInfo.first, &invalidTemp);
    if (invalidTemp)
      return false;
    const char *tokenBegin = file.data() + locInfo.second;
  
    // Lex from the start of the given location.
    Lexer lexer(SM.getLocForStartOfFile(locInfo.first),
                Context.getLangOpts(),
                file.begin(), tokenBegin, file.end());
    Token Tok;
    do {
      lexer.LexFromRawLexer(Tok);
      if (Tok.is(tok::raw_identifier) && Tok.getRawIdentifier() == attrName) {
        Loc = Tok.getLocation();
        return true;
      }
    } while (Tok.isNot(tok::r_paren));
    return false;
  }
  
  /// Check for a mismatch in the atomicity of the given properties.
  static void checkAtomicPropertyMismatch(Sema &S,
                                          ObjCPropertyDecl *OldProperty,
                                          ObjCPropertyDecl *NewProperty,
                                          bool PropagateAtomicity) {
    // If the atomicity of both matches, we're done.
    bool OldIsAtomic =
      (OldProperty->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic)
        == 0;
    bool NewIsAtomic =
      (NewProperty->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic)
        == 0;
    if (OldIsAtomic == NewIsAtomic) return;
  
    // Determine whether the given property is readonly and implicitly
    // atomic.
    auto isImplicitlyReadonlyAtomic = [](ObjCPropertyDecl *Property) -> bool {
      // Is it readonly?
      auto Attrs = Property->getPropertyAttributes();
      if ((Attrs & ObjCPropertyDecl::OBJC_PR_readonly) == 0) return false;
  
      // Is it nonatomic?
      if (Attrs & ObjCPropertyDecl::OBJC_PR_nonatomic) return false;
  
      // Was 'atomic' specified directly?
      if (Property->getPropertyAttributesAsWritten() &
            ObjCPropertyDecl::OBJC_PR_atomic)
        return false;
  
      return true;
    };
  
    // If we're allowed to propagate atomicity, and the new property did
    // not specify atomicity at all, propagate.
    const unsigned AtomicityMask =
      (ObjCPropertyDecl::OBJC_PR_atomic | ObjCPropertyDecl::OBJC_PR_nonatomic);
    if (PropagateAtomicity &&
        ((NewProperty->getPropertyAttributesAsWritten() & AtomicityMask) == 0)) {
      unsigned Attrs = NewProperty->getPropertyAttributes();
      Attrs = Attrs & ~AtomicityMask;
      if (OldIsAtomic)
        Attrs |= ObjCPropertyDecl::OBJC_PR_atomic;
      else
        Attrs |= ObjCPropertyDecl::OBJC_PR_nonatomic;
  
      NewProperty->overwritePropertyAttributes(Attrs);
      return;
    }
  
    // One of the properties is atomic; if it's a readonly property, and
    // 'atomic' wasn't explicitly specified, we're okay.
    if ((OldIsAtomic && isImplicitlyReadonlyAtomic(OldProperty)) ||
        (NewIsAtomic && isImplicitlyReadonlyAtomic(NewProperty)))
      return;
  
    // Diagnose the conflict.
    const IdentifierInfo *OldContextName;
    auto *OldDC = OldProperty->getDeclContext();
    if (auto Category = dyn_cast<ObjCCategoryDecl>(OldDC))
      OldContextName = Category->getClassInterface()->getIdentifier();
    else
      OldContextName = cast<ObjCContainerDecl>(OldDC)->getIdentifier();
  
    S.Diag(NewProperty->getLocation(), diag::warn_property_attribute)
      << NewProperty->getDeclName() << "atomic"
      << OldContextName;
    S.Diag(OldProperty->getLocation(), diag::note_property_declare);
  }
  
  ObjCPropertyDecl *
  Sema::HandlePropertyInClassExtension(Scope *S,
                                       SourceLocation AtLoc,
                                       SourceLocation LParenLoc,
                                       FieldDeclarator &FD,
                                       Selector GetterSel,
                                       SourceLocation GetterNameLoc,
                                       Selector SetterSel,
                                       SourceLocation SetterNameLoc,
                                       const bool isReadWrite,
                                       unsigned &Attributes,
                                       const unsigned AttributesAsWritten,
                                       QualType T,
                                       TypeSourceInfo *TSI,
                                       tok::ObjCKeywordKind MethodImplKind) {
    ObjCCategoryDecl *CDecl = cast<ObjCCategoryDecl>(CurContext);
    // Diagnose if this property is already in continuation class.
    DeclContext *DC = CurContext;
    IdentifierInfo *PropertyId = FD.D.getIdentifier();
    ObjCInterfaceDecl *CCPrimary = CDecl->getClassInterface();
  
    // We need to look in the @interface to see if the @property was
    // already declared.
    if (!CCPrimary) {
      Diag(CDecl->getLocation(), diag::err_continuation_class);
      return nullptr;
    }
  
    bool isClassProperty = (AttributesAsWritten & ObjCDeclSpec::DQ_PR_class) ||
                           (Attributes & ObjCDeclSpec::DQ_PR_class);
  
    // Find the property in the extended class's primary class or
    // extensions.
    ObjCPropertyDecl *PIDecl = CCPrimary->FindPropertyVisibleInPrimaryClass(
        PropertyId, ObjCPropertyDecl::getQueryKind(isClassProperty));
  
    // If we found a property in an extension, complain.
    if (PIDecl && isa<ObjCCategoryDecl>(PIDecl->getDeclContext())) {
      Diag(AtLoc, diag::err_duplicate_property);
      Diag(PIDecl->getLocation(), diag::note_property_declare);
      return nullptr;
    }
  
    // Check for consistency with the previous declaration, if there is one.
    if (PIDecl) {
      // A readonly property declared in the primary class can be refined
      // by adding a readwrite property within an extension.
      // Anything else is an error.
      if (!(PIDecl->isReadOnly() && isReadWrite)) {
        // Tailor the diagnostics for the common case where a readwrite
        // property is declared both in the @interface and the continuation.
        // This is a common error where the user often intended the original
        // declaration to be readonly.
        unsigned diag =
          (Attributes & ObjCDeclSpec::DQ_PR_readwrite) &&
          (PIDecl->getPropertyAttributesAsWritten() &
             ObjCPropertyDecl::OBJC_PR_readwrite)
          ? diag::err_use_continuation_class_redeclaration_readwrite
          : diag::err_use_continuation_class;
        Diag(AtLoc, diag)
          << CCPrimary->getDeclName();
        Diag(PIDecl->getLocation(), diag::note_property_declare);
        return nullptr;
      }
  
      // Check for consistency of getters.
      if (PIDecl->getGetterName() != GetterSel) {
       // If the getter was written explicitly, complain.
        if (AttributesAsWritten & ObjCDeclSpec::DQ_PR_getter) {
          Diag(AtLoc, diag::warn_property_redecl_getter_mismatch)
            << PIDecl->getGetterName() << GetterSel;
          Diag(PIDecl->getLocation(), diag::note_property_declare);
        }
  
        // Always adopt the getter from the original declaration.
        GetterSel = PIDecl->getGetterName();
        Attributes |= ObjCDeclSpec::DQ_PR_getter;
      }
  
      // Check consistency of ownership.
      unsigned ExistingOwnership
        = getOwnershipRule(PIDecl->getPropertyAttributes());
      unsigned NewOwnership = getOwnershipRule(Attributes);
      if (ExistingOwnership && NewOwnership != ExistingOwnership) {
        // If the ownership was written explicitly, complain.
        if (getOwnershipRule(AttributesAsWritten)) {
          Diag(AtLoc, diag::warn_property_attr_mismatch);
          Diag(PIDecl->getLocation(), diag::note_property_declare);
        }
  
        // Take the ownership from the original property.
        Attributes = (Attributes & ~OwnershipMask) | ExistingOwnership;
      }
  
      // If the redeclaration is 'weak' but the original property is not,
      if ((Attributes & ObjCPropertyDecl::OBJC_PR_weak) &&
          !(PIDecl->getPropertyAttributesAsWritten()
              & ObjCPropertyDecl::OBJC_PR_weak) &&
          PIDecl->getType()->getAs<ObjCObjectPointerType>() &&
          PIDecl->getType().getObjCLifetime() == Qualifiers::OCL_None) {
        Diag(AtLoc, diag::warn_property_implicitly_mismatched);
        Diag(PIDecl->getLocation(), diag::note_property_declare);
      }
    }
  
    // Create a new ObjCPropertyDecl with the DeclContext being
    // the class extension.
    ObjCPropertyDecl *PDecl = CreatePropertyDecl(S, CDecl, AtLoc, LParenLoc,
                                                 FD, GetterSel, GetterNameLoc,
                                                 SetterSel, SetterNameLoc,
                                                 isReadWrite,
                                                 Attributes, AttributesAsWritten,
                                                 T, TSI, MethodImplKind, DC);
  
    // If there was no declaration of a property with the same name in
    // the primary class, we're done.
    if (!PIDecl) {
      ProcessPropertyDecl(PDecl);
      return PDecl;
    }
  
    if (!Context.hasSameType(PIDecl->getType(), PDecl->getType())) {
      bool IncompatibleObjC = false;
      QualType ConvertedType;
      // Relax the strict type matching for property type in continuation class.
      // Allow property object type of continuation class to be different as long
      // as it narrows the object type in its primary class property. Note that
      // this conversion is safe only because the wider type is for a 'readonly'
      // property in primary class and 'narrowed' type for a 'readwrite' property
      // in continuation class.
      QualType PrimaryClassPropertyT = Context.getCanonicalType(PIDecl->getType());
      QualType ClassExtPropertyT = Context.getCanonicalType(PDecl->getType());
      if (!isa<ObjCObjectPointerType>(PrimaryClassPropertyT) ||
          !isa<ObjCObjectPointerType>(ClassExtPropertyT) ||
          (!isObjCPointerConversion(ClassExtPropertyT, PrimaryClassPropertyT,
                                    ConvertedType, IncompatibleObjC))
          || IncompatibleObjC) {
        Diag(AtLoc,
            diag::err_type_mismatch_continuation_class) << PDecl->getType();
        Diag(PIDecl->getLocation(), diag::note_property_declare);
        return nullptr;
      }
    }
  
    // Check that atomicity of property in class extension matches the previous
    // declaration.
    checkAtomicPropertyMismatch(*this, PIDecl, PDecl, true);
  
    // Make sure getter/setter are appropriately synthesized.
    ProcessPropertyDecl(PDecl);
    return PDecl;
  }
  
  ObjCPropertyDecl *Sema::CreatePropertyDecl(Scope *S,
                                             ObjCContainerDecl *CDecl,
                                             SourceLocation AtLoc,
                                             SourceLocation LParenLoc,
                                             FieldDeclarator &FD,
                                             Selector GetterSel,
                                             SourceLocation GetterNameLoc,
                                             Selector SetterSel,
                                             SourceLocation SetterNameLoc,
                                             const bool isReadWrite,
                                             const unsigned Attributes,
                                             const unsigned AttributesAsWritten,
                                             QualType T,
                                             TypeSourceInfo *TInfo,
                                             tok::ObjCKeywordKind MethodImplKind,
                                             DeclContext *lexicalDC){
    IdentifierInfo *PropertyId = FD.D.getIdentifier();
  
    // Property defaults to 'assign' if it is readwrite, unless this is ARC
    // and the type is retainable.
    bool isAssign;
    if (Attributes & (ObjCDeclSpec::DQ_PR_assign |
                      ObjCDeclSpec::DQ_PR_unsafe_unretained)) {
      isAssign = true;
    } else if (getOwnershipRule(Attributes) || !isReadWrite) {
      isAssign = false;
    } else {
      isAssign = (!getLangOpts().ObjCAutoRefCount ||
                  !T->isObjCRetainableType());
    }
  
    // Issue a warning if property is 'assign' as default and its
    // object, which is gc'able conforms to NSCopying protocol
    if (getLangOpts().getGC() != LangOptions::NonGC &&
        isAssign && !(Attributes & ObjCDeclSpec::DQ_PR_assign)) {
      if (const ObjCObjectPointerType *ObjPtrTy =
            T->getAs<ObjCObjectPointerType>()) {
        ObjCInterfaceDecl *IDecl = ObjPtrTy->getObjectType()->getInterface();
        if (IDecl)
          if (ObjCProtocolDecl* PNSCopying =
              LookupProtocol(&Context.Idents.get("NSCopying"), AtLoc))
            if (IDecl->ClassImplementsProtocol(PNSCopying, true))
              Diag(AtLoc, diag::warn_implements_nscopying) << PropertyId;
      }
    }
  
    if (T->isObjCObjectType()) {
      SourceLocation StarLoc = TInfo->getTypeLoc().getEndLoc();
      StarLoc = getLocForEndOfToken(StarLoc);
      Diag(FD.D.getIdentifierLoc(), diag::err_statically_allocated_object)
        << FixItHint::CreateInsertion(StarLoc, "*");
      T = Context.getObjCObjectPointerType(T);
      SourceLocation TLoc = TInfo->getTypeLoc().getBeginLoc();
      TInfo = Context.getTrivialTypeSourceInfo(T, TLoc);
    }
  
    DeclContext *DC = CDecl;
    ObjCPropertyDecl *PDecl = ObjCPropertyDecl::Create(Context, DC,
                                                       FD.D.getIdentifierLoc(),
                                                       PropertyId, AtLoc,
                                                       LParenLoc, T, TInfo);
  
    bool isClassProperty = (AttributesAsWritten & ObjCDeclSpec::DQ_PR_class) ||
                           (Attributes & ObjCDeclSpec::DQ_PR_class);
    // Class property and instance property can have the same name.
    if (ObjCPropertyDecl *prevDecl = ObjCPropertyDecl::findPropertyDecl(
            DC, PropertyId, ObjCPropertyDecl::getQueryKind(isClassProperty))) {
      Diag(PDecl->getLocation(), diag::err_duplicate_property);
      Diag(prevDecl->getLocation(), diag::note_property_declare);
      PDecl->setInvalidDecl();
    }
    else {
      DC->addDecl(PDecl);
      if (lexicalDC)
        PDecl->setLexicalDeclContext(lexicalDC);
    }
  
    if (T->isArrayType() || T->isFunctionType()) {
      Diag(AtLoc, diag::err_property_type) << T;
      PDecl->setInvalidDecl();
    }
  
    ProcessDeclAttributes(S, PDecl, FD.D);
  
    // Regardless of setter/getter attribute, we save the default getter/setter
    // selector names in anticipation of declaration of setter/getter methods.
    PDecl->setGetterName(GetterSel, GetterNameLoc);
    PDecl->setSetterName(SetterSel, SetterNameLoc);
    PDecl->setPropertyAttributesAsWritten(
                            makePropertyAttributesAsWritten(AttributesAsWritten));
  
    if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readonly);
  
    if (Attributes & ObjCDeclSpec::DQ_PR_getter)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_getter);
  
    if (Attributes & ObjCDeclSpec::DQ_PR_setter)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_setter);
  
    if (isReadWrite)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readwrite);
  
    if (Attributes & ObjCDeclSpec::DQ_PR_retain)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_retain);
  
    if (Attributes & ObjCDeclSpec::DQ_PR_strong)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
  
    if (Attributes & ObjCDeclSpec::DQ_PR_weak)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_weak);
  
    if (Attributes & ObjCDeclSpec::DQ_PR_copy)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_copy);
  
    if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
  
    if (isAssign)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_assign);
  
    // In the semantic attributes, one of nonatomic or atomic is always set.
    if (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_nonatomic);
    else
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_atomic);
  
    // 'unsafe_unretained' is alias for 'assign'.
    if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_assign);
    if (isAssign)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
  
    if (MethodImplKind == tok::objc_required)
      PDecl->setPropertyImplementation(ObjCPropertyDecl::Required);
    else if (MethodImplKind == tok::objc_optional)
      PDecl->setPropertyImplementation(ObjCPropertyDecl::Optional);
  
    if (Attributes & ObjCDeclSpec::DQ_PR_nullability)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_nullability);
  
    if (Attributes & ObjCDeclSpec::DQ_PR_null_resettable)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_null_resettable);
  
   if (Attributes & ObjCDeclSpec::DQ_PR_class)
      PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_class);
  
    return PDecl;
  }
  
  static void checkARCPropertyImpl(Sema &S, SourceLocation propertyImplLoc,
                                   ObjCPropertyDecl *property,
                                   ObjCIvarDecl *ivar) {
    if (property->isInvalidDecl() || ivar->isInvalidDecl()) return;
  
    QualType ivarType = ivar->getType();
    Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
  
    // The lifetime implied by the property's attributes.
    Qualifiers::ObjCLifetime propertyLifetime =
      getImpliedARCOwnership(property->getPropertyAttributes(),
                             property->getType());
  
    // We're fine if they match.
    if (propertyLifetime == ivarLifetime) return;
  
    // None isn't a valid lifetime for an object ivar in ARC, and
    // __autoreleasing is never valid; don't diagnose twice.
    if ((ivarLifetime == Qualifiers::OCL_None &&
         S.getLangOpts().ObjCAutoRefCount) ||
        ivarLifetime == Qualifiers::OCL_Autoreleasing)
      return;
  
    // If the ivar is private, and it's implicitly __unsafe_unretained
    // becaues of its type, then pretend it was actually implicitly
    // __strong.  This is only sound because we're processing the
    // property implementation before parsing any method bodies.
    if (ivarLifetime == Qualifiers::OCL_ExplicitNone &&
        propertyLifetime == Qualifiers::OCL_Strong &&
        ivar->getAccessControl() == ObjCIvarDecl::Private) {
      SplitQualType split = ivarType.split();
      if (split.Quals.hasObjCLifetime()) {
        assert(ivarType->isObjCARCImplicitlyUnretainedType());
        split.Quals.setObjCLifetime(Qualifiers::OCL_Strong);
        ivarType = S.Context.getQualifiedType(split);
        ivar->setType(ivarType);
        return;
      }
    }
  
    switch (propertyLifetime) {
    case Qualifiers::OCL_Strong:
      S.Diag(ivar->getLocation(), diag::err_arc_strong_property_ownership)
        << property->getDeclName()
        << ivar->getDeclName()
        << ivarLifetime;
      break;
  
    case Qualifiers::OCL_Weak:
      S.Diag(ivar->getLocation(), diag::err_weak_property)
        << property->getDeclName()
        << ivar->getDeclName();
      break;
  
    case Qualifiers::OCL_ExplicitNone:
      S.Diag(ivar->getLocation(), diag::err_arc_assign_property_ownership)
        << property->getDeclName()
        << ivar->getDeclName()
        << ((property->getPropertyAttributesAsWritten()
             & ObjCPropertyDecl::OBJC_PR_assign) != 0);
      break;
  
    case Qualifiers::OCL_Autoreleasing:
      llvm_unreachable("properties cannot be autoreleasing");
  
    case Qualifiers::OCL_None:
      // Any other property should be ignored.
      return;
    }
  
    S.Diag(property->getLocation(), diag::note_property_declare);
    if (propertyImplLoc.isValid())
      S.Diag(propertyImplLoc, diag::note_property_synthesize);
  }
  
  /// setImpliedPropertyAttributeForReadOnlyProperty -
  /// This routine evaludates life-time attributes for a 'readonly'
  /// property with no known lifetime of its own, using backing
  /// 'ivar's attribute, if any. If no backing 'ivar', property's
  /// life-time is assumed 'strong'.
  static void setImpliedPropertyAttributeForReadOnlyProperty(
                ObjCPropertyDecl *property, ObjCIvarDecl *ivar) {
    Qualifiers::ObjCLifetime propertyLifetime =
      getImpliedARCOwnership(property->getPropertyAttributes(),
                             property->getType());
    if (propertyLifetime != Qualifiers::OCL_None)
      return;
  
    if (!ivar) {
      // if no backing ivar, make property 'strong'.
      property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
      return;
    }
    // property assumes owenership of backing ivar.
    QualType ivarType = ivar->getType();
    Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
    if (ivarLifetime == Qualifiers::OCL_Strong)
      property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
    else if (ivarLifetime == Qualifiers::OCL_Weak)
      property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_weak);
  }
  
  static bool
  isIncompatiblePropertyAttribute(unsigned Attr1, unsigned Attr2,
                                  ObjCPropertyDecl::PropertyAttributeKind Kind) {
    return (Attr1 & Kind) != (Attr2 & Kind);
  }
  
  static bool areIncompatiblePropertyAttributes(unsigned Attr1, unsigned Attr2,
                                                unsigned Kinds) {
    return ((Attr1 & Kinds) != 0) != ((Attr2 & Kinds) != 0);
  }
  
  /// SelectPropertyForSynthesisFromProtocols - Finds the most appropriate
  /// property declaration that should be synthesised in all of the inherited
  /// protocols. It also diagnoses properties declared in inherited protocols with
  /// mismatched types or attributes, since any of them can be candidate for
  /// synthesis.
  static ObjCPropertyDecl *
  SelectPropertyForSynthesisFromProtocols(Sema &S, SourceLocation AtLoc,
                                          ObjCInterfaceDecl *ClassDecl,
                                          ObjCPropertyDecl *Property) {
    assert(isa<ObjCProtocolDecl>(Property->getDeclContext()) &&
           "Expected a property from a protocol");
    ObjCInterfaceDecl::ProtocolPropertySet ProtocolSet;
    ObjCInterfaceDecl::PropertyDeclOrder Properties;
    for (const auto *PI : ClassDecl->all_referenced_protocols()) {
      if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
        PDecl->collectInheritedProtocolProperties(Property, ProtocolSet,
                                                  Properties);
    }
    if (ObjCInterfaceDecl *SDecl = ClassDecl->getSuperClass()) {
      while (SDecl) {
        for (const auto *PI : SDecl->all_referenced_protocols()) {
          if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
            PDecl->collectInheritedProtocolProperties(Property, ProtocolSet,
                                                      Properties);
        }
        SDecl = SDecl->getSuperClass();
      }
    }
  
    if (Properties.empty())
      return Property;
  
    ObjCPropertyDecl *OriginalProperty = Property;
    size_t SelectedIndex = 0;
    for (const auto &Prop : llvm::enumerate(Properties)) {
      // Select the 'readwrite' property if such property exists.
      if (Property->isReadOnly() && !Prop.value()->isReadOnly()) {
        Property = Prop.value();
        SelectedIndex = Prop.index();
      }
    }
    if (Property != OriginalProperty) {
      // Check that the old property is compatible with the new one.
      Properties[SelectedIndex] = OriginalProperty;
    }
  
    QualType RHSType = S.Context.getCanonicalType(Property->getType());
    unsigned OriginalAttributes = Property->getPropertyAttributesAsWritten();
    enum MismatchKind {
      IncompatibleType = 0,
      HasNoExpectedAttribute,
      HasUnexpectedAttribute,
      DifferentGetter,
      DifferentSetter
    };
    // Represents a property from another protocol that conflicts with the
    // selected declaration.
    struct MismatchingProperty {
      const ObjCPropertyDecl *Prop;
      MismatchKind Kind;
      StringRef AttributeName;
    };
    SmallVector<MismatchingProperty, 4> Mismatches;
    for (ObjCPropertyDecl *Prop : Properties) {
      // Verify the property attributes.
      unsigned Attr = Prop->getPropertyAttributesAsWritten();
      if (Attr != OriginalAttributes) {
        auto Diag = [&](bool OriginalHasAttribute, StringRef AttributeName) {
          MismatchKind Kind = OriginalHasAttribute ? HasNoExpectedAttribute
                                                   : HasUnexpectedAttribute;
          Mismatches.push_back({Prop, Kind, AttributeName});
        };
        // The ownership might be incompatible unless the property has no explicit
        // ownership.
        bool HasOwnership = (Attr & (ObjCPropertyDecl::OBJC_PR_retain |
                                     ObjCPropertyDecl::OBJC_PR_strong |
                                     ObjCPropertyDecl::OBJC_PR_copy |
                                     ObjCPropertyDecl::OBJC_PR_assign |
                                     ObjCPropertyDecl::OBJC_PR_unsafe_unretained |
                                     ObjCPropertyDecl::OBJC_PR_weak)) != 0;
        if (HasOwnership &&
            isIncompatiblePropertyAttribute(OriginalAttributes, Attr,
                                            ObjCPropertyDecl::OBJC_PR_copy)) {
          Diag(OriginalAttributes & ObjCPropertyDecl::OBJC_PR_copy, "copy");
          continue;
        }
        if (HasOwnership && areIncompatiblePropertyAttributes(
                                OriginalAttributes, Attr,
                                ObjCPropertyDecl::OBJC_PR_retain |
                                    ObjCPropertyDecl::OBJC_PR_strong)) {
          Diag(OriginalAttributes & (ObjCPropertyDecl::OBJC_PR_retain |
                                     ObjCPropertyDecl::OBJC_PR_strong),
               "retain (or strong)");
          continue;
        }
        if (isIncompatiblePropertyAttribute(OriginalAttributes, Attr,
                                            ObjCPropertyDecl::OBJC_PR_atomic)) {
          Diag(OriginalAttributes & ObjCPropertyDecl::OBJC_PR_atomic, "atomic");
          continue;
        }
      }
      if (Property->getGetterName() != Prop->getGetterName()) {
        Mismatches.push_back({Prop, DifferentGetter, ""});
        continue;
      }
      if (!Property->isReadOnly() && !Prop->isReadOnly() &&
          Property->getSetterName() != Prop->getSetterName()) {
        Mismatches.push_back({Prop, DifferentSetter, ""});
        continue;
      }
      QualType LHSType = S.Context.getCanonicalType(Prop->getType());
      if (!S.Context.propertyTypesAreCompatible(LHSType, RHSType)) {
        bool IncompatibleObjC = false;
        QualType ConvertedType;
        if (!S.isObjCPointerConversion(RHSType, LHSType, ConvertedType, IncompatibleObjC)
            || IncompatibleObjC) {
          Mismatches.push_back({Prop, IncompatibleType, ""});
          continue;
        }
      }
    }
  
    if (Mismatches.empty())
      return Property;
  
    // Diagnose incompability.
    {
      bool HasIncompatibleAttributes = false;
      for (const auto &Note : Mismatches)
        HasIncompatibleAttributes =
            Note.Kind != IncompatibleType ? true : HasIncompatibleAttributes;
      // Promote the warning to an error if there are incompatible attributes or
      // incompatible types together with readwrite/readonly incompatibility.
      auto Diag = S.Diag(Property->getLocation(),
                         Property != OriginalProperty || HasIncompatibleAttributes
                             ? diag::err_protocol_property_mismatch
                             : diag::warn_protocol_property_mismatch);
      Diag << Mismatches[0].Kind;
      switch (Mismatches[0].Kind) {
      case IncompatibleType:
        Diag << Property->getType();
        break;
      case HasNoExpectedAttribute:
      case HasUnexpectedAttribute:
        Diag << Mismatches[0].AttributeName;
        break;
      case DifferentGetter:
        Diag << Property->getGetterName();
        break;
      case DifferentSetter:
        Diag << Property->getSetterName();
        break;
      }
    }
    for (const auto &Note : Mismatches) {
      auto Diag =
          S.Diag(Note.Prop->getLocation(), diag::note_protocol_property_declare)
          << Note.Kind;
      switch (Note.Kind) {
      case IncompatibleType:
        Diag << Note.Prop->getType();
        break;
      case HasNoExpectedAttribute:
      case HasUnexpectedAttribute:
        Diag << Note.AttributeName;
        break;
      case DifferentGetter:
        Diag << Note.Prop->getGetterName();
        break;
      case DifferentSetter:
        Diag << Note.Prop->getSetterName();
        break;
      }
    }
    if (AtLoc.isValid())
      S.Diag(AtLoc, diag::note_property_synthesize);
  
    return Property;
  }
  
  /// Determine whether any storage attributes were written on the property.
  static bool hasWrittenStorageAttribute(ObjCPropertyDecl *Prop,
                                         ObjCPropertyQueryKind QueryKind) {
    if (Prop->getPropertyAttributesAsWritten() & OwnershipMask) return true;
  
    // If this is a readwrite property in a class extension that refines
    // a readonly property in the original class definition, check it as
    // well.
  
    // If it's a readonly property, we're not interested.
    if (Prop->isReadOnly()) return false;
  
    // Is it declared in an extension?
    auto Category = dyn_cast<ObjCCategoryDecl>(Prop->getDeclContext());
    if (!Category || !Category->IsClassExtension()) return false;
  
    // Find the corresponding property in the primary class definition.
    auto OrigClass = Category->getClassInterface();
    for (auto Found : OrigClass->lookup(Prop->getDeclName())) {
      if (ObjCPropertyDecl *OrigProp = dyn_cast<ObjCPropertyDecl>(Found))
        return OrigProp->getPropertyAttributesAsWritten() & OwnershipMask;
    }
  
    // Look through all of the protocols.
    for (const auto *Proto : OrigClass->all_referenced_protocols()) {
      if (ObjCPropertyDecl *OrigProp = Proto->FindPropertyDeclaration(
              Prop->getIdentifier(), QueryKind))
        return OrigProp->getPropertyAttributesAsWritten() & OwnershipMask;
    }
  
    return false;
  }
  
  /// ActOnPropertyImplDecl - This routine performs semantic checks and
  /// builds the AST node for a property implementation declaration; declared
  /// as \@synthesize or \@dynamic.
  ///
  Decl *Sema::ActOnPropertyImplDecl(Scope *S,
                                    SourceLocation AtLoc,
                                    SourceLocation PropertyLoc,
                                    bool Synthesize,
                                    IdentifierInfo *PropertyId,
                                    IdentifierInfo *PropertyIvar,
                                    SourceLocation PropertyIvarLoc,
                                    ObjCPropertyQueryKind QueryKind) {
    ObjCContainerDecl *ClassImpDecl =
      dyn_cast<ObjCContainerDecl>(CurContext);
    // Make sure we have a context for the property implementation declaration.
    if (!ClassImpDecl) {
      Diag(AtLoc, diag::err_missing_property_context);
      return nullptr;
    }
    if (PropertyIvarLoc.isInvalid())
      PropertyIvarLoc = PropertyLoc;
    SourceLocation PropertyDiagLoc = PropertyLoc;
    if (PropertyDiagLoc.isInvalid())
      PropertyDiagLoc = ClassImpDecl->getBeginLoc();
    ObjCPropertyDecl *property = nullptr;
    ObjCInterfaceDecl *IDecl = nullptr;
    // Find the class or category class where this property must have
    // a declaration.
    ObjCImplementationDecl *IC = nullptr;
    ObjCCategoryImplDecl *CatImplClass = nullptr;
    if ((IC = dyn_cast<ObjCImplementationDecl>(ClassImpDecl))) {
      IDecl = IC->getClassInterface();
      // We always synthesize an interface for an implementation
      // without an interface decl. So, IDecl is always non-zero.
      assert(IDecl &&
             "ActOnPropertyImplDecl - @implementation without @interface");
  
      // Look for this property declaration in the @implementation's @interface
      property = IDecl->FindPropertyDeclaration(PropertyId, QueryKind);
      if (!property) {
        Diag(PropertyLoc, diag::err_bad_property_decl) << IDecl->getDeclName();
        return nullptr;
      }
      if (property->isClassProperty() && Synthesize) {
        Diag(PropertyLoc, diag::err_synthesize_on_class_property) << PropertyId;
        return nullptr;
      }
      unsigned PIkind = property->getPropertyAttributesAsWritten();
      if ((PIkind & (ObjCPropertyDecl::OBJC_PR_atomic |
                     ObjCPropertyDecl::OBJC_PR_nonatomic) ) == 0) {
        if (AtLoc.isValid())
          Diag(AtLoc, diag::warn_implicit_atomic_property);
        else
          Diag(IC->getLocation(), diag::warn_auto_implicit_atomic_property);
        Diag(property->getLocation(), diag::note_property_declare);
      }
  
      if (const ObjCCategoryDecl *CD =
          dyn_cast<ObjCCategoryDecl>(property->getDeclContext())) {
        if (!CD->IsClassExtension()) {
          Diag(PropertyLoc, diag::err_category_property) << CD->getDeclName();
          Diag(property->getLocation(), diag::note_property_declare);
          return nullptr;
        }
      }
      if (Synthesize&&
          (PIkind & ObjCPropertyDecl::OBJC_PR_readonly) &&
          property->hasAttr<IBOutletAttr>() &&
          !AtLoc.isValid()) {
        bool ReadWriteProperty = false;
        // Search into the class extensions and see if 'readonly property is
        // redeclared 'readwrite', then no warning is to be issued.
        for (auto *Ext : IDecl->known_extensions()) {
          DeclContext::lookup_result R = Ext->lookup(property->getDeclName());
          if (!R.empty())
            if (ObjCPropertyDecl *ExtProp = dyn_cast<ObjCPropertyDecl>(R[0])) {
              PIkind = ExtProp->getPropertyAttributesAsWritten();
              if (PIkind & ObjCPropertyDecl::OBJC_PR_readwrite) {
                ReadWriteProperty = true;
                break;
              }
            }
        }
  
        if (!ReadWriteProperty) {
          Diag(property->getLocation(), diag::warn_auto_readonly_iboutlet_property)
              << property;
          SourceLocation readonlyLoc;
          if (LocPropertyAttribute(Context, "readonly",
                                   property->getLParenLoc(), readonlyLoc)) {
            SourceLocation endLoc =
              readonlyLoc.getLocWithOffset(strlen("readonly")-1);
            SourceRange ReadonlySourceRange(readonlyLoc, endLoc);
            Diag(property->getLocation(),
                 diag::note_auto_readonly_iboutlet_fixup_suggest) <<
            FixItHint::CreateReplacement(ReadonlySourceRange, "readwrite");
          }
        }
      }
      if (Synthesize && isa<ObjCProtocolDecl>(property->getDeclContext()))
        property = SelectPropertyForSynthesisFromProtocols(*this, AtLoc, IDecl,
                                                           property);
  
    } else if ((CatImplClass = dyn_cast<ObjCCategoryImplDecl>(ClassImpDecl))) {
      if (Synthesize) {
        Diag(AtLoc, diag::err_synthesize_category_decl);
        return nullptr;
      }
      IDecl = CatImplClass->getClassInterface();
      if (!IDecl) {
        Diag(AtLoc, diag::err_missing_property_interface);
        return nullptr;
      }
      ObjCCategoryDecl *Category =
      IDecl->FindCategoryDeclaration(CatImplClass->getIdentifier());
  
      // If category for this implementation not found, it is an error which
      // has already been reported eralier.
      if (!Category)
        return nullptr;
      // Look for this property declaration in @implementation's category
      property = Category->FindPropertyDeclaration(PropertyId, QueryKind);
      if (!property) {
        Diag(PropertyLoc, diag::err_bad_category_property_decl)
        << Category->getDeclName();
        return nullptr;
      }
    } else {
      Diag(AtLoc, diag::err_bad_property_context);
      return nullptr;
    }
    ObjCIvarDecl *Ivar = nullptr;
    bool CompleteTypeErr = false;
    bool compat = true;
    // Check that we have a valid, previously declared ivar for @synthesize
    if (Synthesize) {
      // @synthesize
      if (!PropertyIvar)
        PropertyIvar = PropertyId;
      // Check that this is a previously declared 'ivar' in 'IDecl' interface
      ObjCInterfaceDecl *ClassDeclared;
      Ivar = IDecl->lookupInstanceVariable(PropertyIvar, ClassDeclared);
      QualType PropType = property->getType();
      QualType PropertyIvarType = PropType.getNonReferenceType();
  
      if (RequireCompleteType(PropertyDiagLoc, PropertyIvarType,
                              diag::err_incomplete_synthesized_property,
                              property->getDeclName())) {
        Diag(property->getLocation(), diag::note_property_declare);
        CompleteTypeErr = true;
      }
  
      if (getLangOpts().ObjCAutoRefCount &&
          (property->getPropertyAttributesAsWritten() &
           ObjCPropertyDecl::OBJC_PR_readonly) &&
          PropertyIvarType->isObjCRetainableType()) {
        setImpliedPropertyAttributeForReadOnlyProperty(property, Ivar);
      }
  
      ObjCPropertyDecl::PropertyAttributeKind kind
        = property->getPropertyAttributes();
  
      bool isARCWeak = false;
      if (kind & ObjCPropertyDecl::OBJC_PR_weak) {
        // Add GC __weak to the ivar type if the property is weak.
        if (getLangOpts().getGC() != LangOptions::NonGC) {
          assert(!getLangOpts().ObjCAutoRefCount);
          if (PropertyIvarType.isObjCGCStrong()) {
            Diag(PropertyDiagLoc, diag::err_gc_weak_property_strong_type);
            Diag(property->getLocation(), diag::note_property_declare);
          } else {
            PropertyIvarType =
              Context.getObjCGCQualType(PropertyIvarType, Qualifiers::Weak);
          }
  
        // Otherwise, check whether ARC __weak is enabled and works with
        // the property type.
        } else {
          if (!getLangOpts().ObjCWeak) {
            // Only complain here when synthesizing an ivar.
            if (!Ivar) {
              Diag(PropertyDiagLoc,
                   getLangOpts().ObjCWeakRuntime
                     ? diag::err_synthesizing_arc_weak_property_disabled
                     : diag::err_synthesizing_arc_weak_property_no_runtime);
              Diag(property->getLocation(), diag::note_property_declare);
            }
            CompleteTypeErr = true; // suppress later diagnostics about the ivar
          } else {
            isARCWeak = true;
            if (const ObjCObjectPointerType *ObjT =
                  PropertyIvarType->getAs<ObjCObjectPointerType>()) {
              const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl();
              if (ObjI && ObjI->isArcWeakrefUnavailable()) {
                Diag(property->getLocation(),
                     diag::err_arc_weak_unavailable_property)
                  << PropertyIvarType;
                Diag(ClassImpDecl->getLocation(), diag::note_implemented_by_class)
                  << ClassImpDecl->getName();
              }
            }
          }
        }
      }
  
      if (AtLoc.isInvalid()) {
        // Check when default synthesizing a property that there is
        // an ivar matching property name and issue warning; since this
        // is the most common case of not using an ivar used for backing
        // property in non-default synthesis case.
        ObjCInterfaceDecl *ClassDeclared=nullptr;
        ObjCIvarDecl *originalIvar =
        IDecl->lookupInstanceVariable(property->getIdentifier(),
                                      ClassDeclared);
        if (originalIvar) {
          Diag(PropertyDiagLoc,
               diag::warn_autosynthesis_property_ivar_match)
          << PropertyId << (Ivar == nullptr) << PropertyIvar
          << originalIvar->getIdentifier();
          Diag(property->getLocation(), diag::note_property_declare);
          Diag(originalIvar->getLocation(), diag::note_ivar_decl);
        }
      }
  
      if (!Ivar) {
        // In ARC, give the ivar a lifetime qualifier based on the
        // property attributes.
        if ((getLangOpts().ObjCAutoRefCount || isARCWeak) &&
            !PropertyIvarType.getObjCLifetime() &&
            PropertyIvarType->isObjCRetainableType()) {
  
          // It's an error if we have to do this and the user didn't
          // explicitly write an ownership attribute on the property.
          if (!hasWrittenStorageAttribute(property, QueryKind) &&
              !(kind & ObjCPropertyDecl::OBJC_PR_strong)) {
            Diag(PropertyDiagLoc,
                 diag::err_arc_objc_property_default_assign_on_object);
            Diag(property->getLocation(), diag::note_property_declare);
          } else {
            Qualifiers::ObjCLifetime lifetime =
              getImpliedARCOwnership(kind, PropertyIvarType);
            assert(lifetime && "no lifetime for property?");
  
            Qualifiers qs;
            qs.addObjCLifetime(lifetime);
            PropertyIvarType = Context.getQualifiedType(PropertyIvarType, qs);
          }
        }
  
        Ivar = ObjCIvarDecl::Create(Context, ClassImpDecl,
                                    PropertyIvarLoc,PropertyIvarLoc, PropertyIvar,
                                    PropertyIvarType, /*Dinfo=*/nullptr,
                                    ObjCIvarDecl::Private,
                                    (Expr *)nullptr, true);
        if (RequireNonAbstractType(PropertyIvarLoc,
                                   PropertyIvarType,
                                   diag::err_abstract_type_in_decl,
                                   AbstractSynthesizedIvarType)) {
          Diag(property->getLocation(), diag::note_property_declare);
          // An abstract type is as bad as an incomplete type.
          CompleteTypeErr = true;
        }
        if (!CompleteTypeErr) {
          const RecordType *RecordTy = PropertyIvarType->getAs<RecordType>();
          if (RecordTy && RecordTy->getDecl()->hasFlexibleArrayMember()) {
            Diag(PropertyIvarLoc, diag::err_synthesize_variable_sized_ivar)
              << PropertyIvarType;
            CompleteTypeErr = true; // suppress later diagnostics about the ivar
          }
        }
        if (CompleteTypeErr)
          Ivar->setInvalidDecl();
        ClassImpDecl->addDecl(Ivar);
        IDecl->makeDeclVisibleInContext(Ivar);
  
        if (getLangOpts().ObjCRuntime.isFragile())
          Diag(PropertyDiagLoc, diag::err_missing_property_ivar_decl)
              << PropertyId;
        // Note! I deliberately want it to fall thru so, we have a
        // a property implementation and to avoid future warnings.
      } else if (getLangOpts().ObjCRuntime.isNonFragile() &&
                 !declaresSameEntity(ClassDeclared, IDecl)) {
        Diag(PropertyDiagLoc, diag::err_ivar_in_superclass_use)
        << property->getDeclName() << Ivar->getDeclName()
        << ClassDeclared->getDeclName();
        Diag(Ivar->getLocation(), diag::note_previous_access_declaration)
        << Ivar << Ivar->getName();
        // Note! I deliberately want it to fall thru so more errors are caught.
      }
      property->setPropertyIvarDecl(Ivar);
  
      QualType IvarType = Context.getCanonicalType(Ivar->getType());
  
      // Check that type of property and its ivar are type compatible.
      if (!Context.hasSameType(PropertyIvarType, IvarType)) {
        if (isa<ObjCObjectPointerType>(PropertyIvarType)
            && isa<ObjCObjectPointerType>(IvarType))
          compat =
            Context.canAssignObjCInterfaces(
                                    PropertyIvarType->getAs<ObjCObjectPointerType>(),
                                    IvarType->getAs<ObjCObjectPointerType>());
        else {
          compat = (CheckAssignmentConstraints(PropertyIvarLoc, PropertyIvarType,
                                               IvarType)
                      == Compatible);
        }
        if (!compat) {
          Diag(PropertyDiagLoc, diag::err_property_ivar_type)
            << property->getDeclName() << PropType
            << Ivar->getDeclName() << IvarType;
          Diag(Ivar->getLocation(), diag::note_ivar_decl);
          // Note! I deliberately want it to fall thru so, we have a
          // a property implementation and to avoid future warnings.
        }
        else {
          // FIXME! Rules for properties are somewhat different that those
          // for assignments. Use a new routine to consolidate all cases;
          // specifically for property redeclarations as well as for ivars.
          QualType lhsType =Context.getCanonicalType(PropertyIvarType).getUnqualifiedType();
          QualType rhsType =Context.getCanonicalType(IvarType).getUnqualifiedType();
          if (lhsType != rhsType &&
              lhsType->isArithmeticType()) {
            Diag(PropertyDiagLoc, diag::err_property_ivar_type)
              << property->getDeclName() << PropType
              << Ivar->getDeclName() << IvarType;
            Diag(Ivar->getLocation(), diag::note_ivar_decl);
            // Fall thru - see previous comment
          }
        }
        // __weak is explicit. So it works on Canonical type.
        if ((PropType.isObjCGCWeak() && !IvarType.isObjCGCWeak() &&
             getLangOpts().getGC() != LangOptions::NonGC)) {
          Diag(PropertyDiagLoc, diag::err_weak_property)
          << property->getDeclName() << Ivar->getDeclName();
          Diag(Ivar->getLocation(), diag::note_ivar_decl);
          // Fall thru - see previous comment
        }
        // Fall thru - see previous comment
        if ((property->getType()->isObjCObjectPointerType() ||
             PropType.isObjCGCStrong()) && IvarType.isObjCGCWeak() &&
            getLangOpts().getGC() != LangOptions::NonGC) {
          Diag(PropertyDiagLoc, diag::err_strong_property)
          << property->getDeclName() << Ivar->getDeclName();
          // Fall thru - see previous comment
        }
      }
      if (getLangOpts().ObjCAutoRefCount || isARCWeak ||
          Ivar->getType().getObjCLifetime())
        checkARCPropertyImpl(*this, PropertyLoc, property, Ivar);
    } else if (PropertyIvar)
      // @dynamic
      Diag(PropertyDiagLoc, diag::err_dynamic_property_ivar_decl);
  
    assert (property && "ActOnPropertyImplDecl - property declaration missing");
    ObjCPropertyImplDecl *PIDecl =
    ObjCPropertyImplDecl::Create(Context, CurContext, AtLoc, PropertyLoc,
                                 property,
                                 (Synthesize ?
                                  ObjCPropertyImplDecl::Synthesize
                                  : ObjCPropertyImplDecl::Dynamic),
                                 Ivar, PropertyIvarLoc);
  
    if (CompleteTypeErr || !compat)
      PIDecl->setInvalidDecl();
  
    if (ObjCMethodDecl *getterMethod = property->getGetterMethodDecl()) {
      getterMethod->createImplicitParams(Context, IDecl);
      if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
          Ivar->getType()->isRecordType()) {
        // For Objective-C++, need to synthesize the AST for the IVAR object to be
        // returned by the getter as it must conform to C++'s copy-return rules.
        // FIXME. Eventually we want to do this for Objective-C as well.
        SynthesizedFunctionScope Scope(*this, getterMethod);
        ImplicitParamDecl *SelfDecl = getterMethod->getSelfDecl();
        DeclRefExpr *SelfExpr = new (Context)
            DeclRefExpr(Context, SelfDecl, false, SelfDecl->getType(), VK_LValue,
                        PropertyDiagLoc);
        MarkDeclRefReferenced(SelfExpr);
        Expr *LoadSelfExpr =
          ImplicitCastExpr::Create(Context, SelfDecl->getType(),
                                   CK_LValueToRValue, SelfExpr, nullptr,
                                   VK_RValue);
        Expr *IvarRefExpr =
          new (Context) ObjCIvarRefExpr(Ivar,
                                        Ivar->getUsageType(SelfDecl->getType()),
                                        PropertyDiagLoc,
                                        Ivar->getLocation(),
                                        LoadSelfExpr, true, true);
        ExprResult Res = PerformCopyInitialization(
            InitializedEntity::InitializeResult(PropertyDiagLoc,
                                                getterMethod->getReturnType(),
                                                /*NRVO=*/false),
            PropertyDiagLoc, IvarRefExpr);
        if (!Res.isInvalid()) {
          Expr *ResExpr = Res.getAs<Expr>();
          if (ResExpr)
            ResExpr = MaybeCreateExprWithCleanups(ResExpr);
          PIDecl->setGetterCXXConstructor(ResExpr);
        }
      }
      if (property->hasAttr<NSReturnsNotRetainedAttr>() &&
          !getterMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
        Diag(getterMethod->getLocation(),
             diag::warn_property_getter_owning_mismatch);
        Diag(property->getLocation(), diag::note_property_declare);
      }
      if (getLangOpts().ObjCAutoRefCount && Synthesize)
        switch (getterMethod->getMethodFamily()) {
          case OMF_retain:
          case OMF_retainCount:
          case OMF_release:
          case OMF_autorelease:
            Diag(getterMethod->getLocation(), diag::err_arc_illegal_method_def)
              << 1 << getterMethod->getSelector();
            break;
          default:
            break;
        }
    }
    if (ObjCMethodDecl *setterMethod = property->getSetterMethodDecl()) {
      setterMethod->createImplicitParams(Context, IDecl);
      if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
          Ivar->getType()->isRecordType()) {
        // FIXME. Eventually we want to do this for Objective-C as well.
        SynthesizedFunctionScope Scope(*this, setterMethod);
        ImplicitParamDecl *SelfDecl = setterMethod->getSelfDecl();
        DeclRefExpr *SelfExpr = new (Context)
            DeclRefExpr(Context, SelfDecl, false, SelfDecl->getType(), VK_LValue,
                        PropertyDiagLoc);
        MarkDeclRefReferenced(SelfExpr);
        Expr *LoadSelfExpr =
          ImplicitCastExpr::Create(Context, SelfDecl->getType(),
                                   CK_LValueToRValue, SelfExpr, nullptr,
                                   VK_RValue);
        Expr *lhs =
          new (Context) ObjCIvarRefExpr(Ivar,
                                        Ivar->getUsageType(SelfDecl->getType()),
                                        PropertyDiagLoc,
                                        Ivar->getLocation(),
                                        LoadSelfExpr, true, true);
        ObjCMethodDecl::param_iterator P = setterMethod->param_begin();
        ParmVarDecl *Param = (*P);
        QualType T = Param->getType().getNonReferenceType();
        DeclRefExpr *rhs = new (Context)
            DeclRefExpr(Context, Param, false, T, VK_LValue, PropertyDiagLoc);
        MarkDeclRefReferenced(rhs);
        ExprResult Res = BuildBinOp(S, PropertyDiagLoc,
                                    BO_Assign, lhs, rhs);
        if (property->getPropertyAttributes() &
            ObjCPropertyDecl::OBJC_PR_atomic) {
          Expr *callExpr = Res.getAs<Expr>();
          if (const CXXOperatorCallExpr *CXXCE =
                dyn_cast_or_null<CXXOperatorCallExpr>(callExpr))
            if (const FunctionDecl *FuncDecl = CXXCE->getDirectCallee())
              if (!FuncDecl->isTrivial())
                if (property->getType()->isReferenceType()) {
                  Diag(PropertyDiagLoc,
                       diag::err_atomic_property_nontrivial_assign_op)
                      << property->getType();
                  Diag(FuncDecl->getBeginLoc(), diag::note_callee_decl)
                      << FuncDecl;
                }
        }
        PIDecl->setSetterCXXAssignment(Res.getAs<Expr>());
      }
    }
  
    if (IC) {
      if (Synthesize)
        if (ObjCPropertyImplDecl *PPIDecl =
            IC->FindPropertyImplIvarDecl(PropertyIvar)) {
          Diag(PropertyLoc, diag::err_duplicate_ivar_use)
          << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
          << PropertyIvar;
          Diag(PPIDecl->getLocation(), diag::note_previous_use);
        }
  
      if (ObjCPropertyImplDecl *PPIDecl
          = IC->FindPropertyImplDecl(PropertyId, QueryKind)) {
        Diag(PropertyLoc, diag::err_property_implemented) << PropertyId;
        Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
        return nullptr;
      }
      IC->addPropertyImplementation(PIDecl);
      if (getLangOpts().ObjCDefaultSynthProperties &&
          getLangOpts().ObjCRuntime.isNonFragile() &&
          !IDecl->isObjCRequiresPropertyDefs()) {
        // Diagnose if an ivar was lazily synthesdized due to a previous
        // use and if 1) property is @dynamic or 2) property is synthesized
        // but it requires an ivar of different name.
        ObjCInterfaceDecl *ClassDeclared=nullptr;
        ObjCIvarDecl *Ivar = nullptr;
        if (!Synthesize)
          Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
        else {
          if (PropertyIvar && PropertyIvar != PropertyId)
            Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
        }
        // Issue diagnostics only if Ivar belongs to current class.
        if (Ivar && Ivar->getSynthesize() &&
            declaresSameEntity(IC->getClassInterface(), ClassDeclared)) {
          Diag(Ivar->getLocation(), diag::err_undeclared_var_use)
          << PropertyId;
          Ivar->setInvalidDecl();
        }
      }
    } else {
      if (Synthesize)
        if (ObjCPropertyImplDecl *PPIDecl =
            CatImplClass->FindPropertyImplIvarDecl(PropertyIvar)) {
          Diag(PropertyDiagLoc, diag::err_duplicate_ivar_use)
          << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
          << PropertyIvar;
          Diag(PPIDecl->getLocation(), diag::note_previous_use);
        }
  
      if (ObjCPropertyImplDecl *PPIDecl =
          CatImplClass->FindPropertyImplDecl(PropertyId, QueryKind)) {
        Diag(PropertyDiagLoc, diag::err_property_implemented) << PropertyId;
        Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
        return nullptr;
      }
      CatImplClass->addPropertyImplementation(PIDecl);
    }
  
    return PIDecl;
  }
  
  //===----------------------------------------------------------------------===//
  // Helper methods.
  //===----------------------------------------------------------------------===//
  
  /// DiagnosePropertyMismatch - Compares two properties for their
  /// attributes and types and warns on a variety of inconsistencies.
  ///
  void
  Sema::DiagnosePropertyMismatch(ObjCPropertyDecl *Property,
                                 ObjCPropertyDecl *SuperProperty,
                                 const IdentifierInfo *inheritedName,
                                 bool OverridingProtocolProperty) {
    ObjCPropertyDecl::PropertyAttributeKind CAttr =
      Property->getPropertyAttributes();
    ObjCPropertyDecl::PropertyAttributeKind SAttr =
      SuperProperty->getPropertyAttributes();
  
    // We allow readonly properties without an explicit ownership
    // (assign/unsafe_unretained/weak/retain/strong/copy) in super class
    // to be overridden by a property with any explicit ownership in the subclass.
    if (!OverridingProtocolProperty &&
        !getOwnershipRule(SAttr) && getOwnershipRule(CAttr))
      ;
    else {
      if ((CAttr & ObjCPropertyDecl::OBJC_PR_readonly)
          && (SAttr & ObjCPropertyDecl::OBJC_PR_readwrite))
        Diag(Property->getLocation(), diag::warn_readonly_property)
          << Property->getDeclName() << inheritedName;
      if ((CAttr & ObjCPropertyDecl::OBJC_PR_copy)
          != (SAttr & ObjCPropertyDecl::OBJC_PR_copy))
        Diag(Property->getLocation(), diag::warn_property_attribute)
          << Property->getDeclName() << "copy" << inheritedName;
      else if (!(SAttr & ObjCPropertyDecl::OBJC_PR_readonly)){
        unsigned CAttrRetain =
          (CAttr &
           (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
        unsigned SAttrRetain =
          (SAttr &
           (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
        bool CStrong = (CAttrRetain != 0);
        bool SStrong = (SAttrRetain != 0);
        if (CStrong != SStrong)
          Diag(Property->getLocation(), diag::warn_property_attribute)
            << Property->getDeclName() << "retain (or strong)" << inheritedName;
      }
    }
  
    // Check for nonatomic; note that nonatomic is effectively
    // meaningless for readonly properties, so don't diagnose if the
    // atomic property is 'readonly'.
    checkAtomicPropertyMismatch(*this, SuperProperty, Property, false);
    // Readonly properties from protocols can be implemented as "readwrite"
    // with a custom setter name.
    if (Property->getSetterName() != SuperProperty->getSetterName() &&
        !(SuperProperty->isReadOnly() &&
          isa<ObjCProtocolDecl>(SuperProperty->getDeclContext()))) {
      Diag(Property->getLocation(), diag::warn_property_attribute)
        << Property->getDeclName() << "setter" << inheritedName;
      Diag(SuperProperty->getLocation(), diag::note_property_declare);
    }
    if (Property->getGetterName() != SuperProperty->getGetterName()) {
      Diag(Property->getLocation(), diag::warn_property_attribute)
        << Property->getDeclName() << "getter" << inheritedName;
      Diag(SuperProperty->getLocation(), diag::note_property_declare);
    }
  
    QualType LHSType =
      Context.getCanonicalType(SuperProperty->getType());
    QualType RHSType =
      Context.getCanonicalType(Property->getType());
  
    if (!Context.propertyTypesAreCompatible(LHSType, RHSType)) {
      // Do cases not handled in above.
      // FIXME. For future support of covariant property types, revisit this.
      bool IncompatibleObjC = false;
      QualType ConvertedType;
      if (!isObjCPointerConversion(RHSType, LHSType,
                                   ConvertedType, IncompatibleObjC) ||
          IncompatibleObjC) {
          Diag(Property->getLocation(), diag::warn_property_types_are_incompatible)
          << Property->getType() << SuperProperty->getType() << inheritedName;
        Diag(SuperProperty->getLocation(), diag::note_property_declare);
      }
    }
  }
  
  bool Sema::DiagnosePropertyAccessorMismatch(ObjCPropertyDecl *property,
                                              ObjCMethodDecl *GetterMethod,
                                              SourceLocation Loc) {
    if (!GetterMethod)
      return false;
    QualType GetterType = GetterMethod->getReturnType().getNonReferenceType();
    QualType PropertyRValueType =
        property->getType().getNonReferenceType().getAtomicUnqualifiedType();
    bool compat = Context.hasSameType(PropertyRValueType, GetterType);
    if (!compat) {
      const ObjCObjectPointerType *propertyObjCPtr = nullptr;
      const ObjCObjectPointerType *getterObjCPtr = nullptr;
      if ((propertyObjCPtr =
               PropertyRValueType->getAs<ObjCObjectPointerType>()) &&
          (getterObjCPtr = GetterType->getAs<ObjCObjectPointerType>()))
        compat = Context.canAssignObjCInterfaces(getterObjCPtr, propertyObjCPtr);
      else if (CheckAssignmentConstraints(Loc, GetterType, PropertyRValueType)
                != Compatible) {
            Diag(Loc, diag::err_property_accessor_type)
              << property->getDeclName() << PropertyRValueType
              << GetterMethod->getSelector() << GetterType;
            Diag(GetterMethod->getLocation(), diag::note_declared_at);
            return true;
      } else {
        compat = true;
        QualType lhsType = Context.getCanonicalType(PropertyRValueType);
        QualType rhsType =Context.getCanonicalType(GetterType).getUnqualifiedType();
        if (lhsType != rhsType && lhsType->isArithmeticType())
          compat = false;
      }
    }
  
    if (!compat) {
      Diag(Loc, diag::warn_accessor_property_type_mismatch)
      << property->getDeclName()
      << GetterMethod->getSelector();
      Diag(GetterMethod->getLocation(), diag::note_declared_at);
      return true;
    }
  
    return false;
  }
  
  /// CollectImmediateProperties - This routine collects all properties in
  /// the class and its conforming protocols; but not those in its super class.
  static void
  CollectImmediateProperties(ObjCContainerDecl *CDecl,
                             ObjCContainerDecl::PropertyMap &PropMap,
                             ObjCContainerDecl::PropertyMap &SuperPropMap,
                             bool CollectClassPropsOnly = false,
                             bool IncludeProtocols = true) {
    if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
      for (auto *Prop : IDecl->properties()) {
        if (CollectClassPropsOnly && !Prop->isClassProperty())
          continue;
        PropMap[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] =
            Prop;
      }
  
      // Collect the properties from visible extensions.
      for (auto *Ext : IDecl->visible_extensions())
        CollectImmediateProperties(Ext, PropMap, SuperPropMap,
                                   CollectClassPropsOnly, IncludeProtocols);
  
      if (IncludeProtocols) {
        // Scan through class's protocols.
        for (auto *PI : IDecl->all_referenced_protocols())
          CollectImmediateProperties(PI, PropMap, SuperPropMap,
                                     CollectClassPropsOnly);
      }
    }
    if (ObjCCategoryDecl *CATDecl = dyn_cast<ObjCCategoryDecl>(CDecl)) {
      for (auto *Prop : CATDecl->properties()) {
        if (CollectClassPropsOnly && !Prop->isClassProperty())
          continue;
        PropMap[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] =
            Prop;
      }
      if (IncludeProtocols) {
        // Scan through class's protocols.
        for (auto *PI : CATDecl->protocols())
          CollectImmediateProperties(PI, PropMap, SuperPropMap,
                                     CollectClassPropsOnly);
      }
    }
    else if (ObjCProtocolDecl *PDecl = dyn_cast<ObjCProtocolDecl>(CDecl)) {
      for (auto *Prop : PDecl->properties()) {
        if (CollectClassPropsOnly && !Prop->isClassProperty())
          continue;
        ObjCPropertyDecl *PropertyFromSuper =
            SuperPropMap[std::make_pair(Prop->getIdentifier(),
                                        Prop->isClassProperty())];
        // Exclude property for protocols which conform to class's super-class,
        // as super-class has to implement the property.
        if (!PropertyFromSuper ||
            PropertyFromSuper->getIdentifier() != Prop->getIdentifier()) {
          ObjCPropertyDecl *&PropEntry =
              PropMap[std::make_pair(Prop->getIdentifier(),
                                     Prop->isClassProperty())];
          if (!PropEntry)
            PropEntry = Prop;
        }
      }
      // Scan through protocol's protocols.
      for (auto *PI : PDecl->protocols())
        CollectImmediateProperties(PI, PropMap, SuperPropMap,
                                   CollectClassPropsOnly);
    }
  }
  
  /// CollectSuperClassPropertyImplementations - This routine collects list of
  /// properties to be implemented in super class(s) and also coming from their
  /// conforming protocols.
  static void CollectSuperClassPropertyImplementations(ObjCInterfaceDecl *CDecl,
                                      ObjCInterfaceDecl::PropertyMap &PropMap) {
    if (ObjCInterfaceDecl *SDecl = CDecl->getSuperClass()) {
      ObjCInterfaceDecl::PropertyDeclOrder PO;
      while (SDecl) {
        SDecl->collectPropertiesToImplement(PropMap, PO);
        SDecl = SDecl->getSuperClass();
      }
    }
  }
  
  /// IvarBacksCurrentMethodAccessor - This routine returns 'true' if 'IV' is
  /// an ivar synthesized for 'Method' and 'Method' is a property accessor
  /// declared in class 'IFace'.
  bool
  Sema::IvarBacksCurrentMethodAccessor(ObjCInterfaceDecl *IFace,
                                       ObjCMethodDecl *Method, ObjCIvarDecl *IV) {
    if (!IV->getSynthesize())
      return false;
    ObjCMethodDecl *IMD = IFace->lookupMethod(Method->getSelector(),
                                              Method->isInstanceMethod());
    if (!IMD || !IMD->isPropertyAccessor())
      return false;
  
    // look up a property declaration whose one of its accessors is implemented
    // by this method.
    for (const auto *Property : IFace->instance_properties()) {
      if ((Property->getGetterName() == IMD->getSelector() ||
           Property->getSetterName() == IMD->getSelector()) &&
          (Property->getPropertyIvarDecl() == IV))
        return true;
    }
    // Also look up property declaration in class extension whose one of its
    // accessors is implemented by this method.
    for (const auto *Ext : IFace->known_extensions())
      for (const auto *Property : Ext->instance_properties())
        if ((Property->getGetterName() == IMD->getSelector() ||
             Property->getSetterName() == IMD->getSelector()) &&
            (Property->getPropertyIvarDecl() == IV))
          return true;
    return false;
  }
  
  static bool SuperClassImplementsProperty(ObjCInterfaceDecl *IDecl,
                                           ObjCPropertyDecl *Prop) {
    bool SuperClassImplementsGetter = false;
    bool SuperClassImplementsSetter = false;
    if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
      SuperClassImplementsSetter = true;
  
    while (IDecl->getSuperClass()) {
      ObjCInterfaceDecl *SDecl = IDecl->getSuperClass();
      if (!SuperClassImplementsGetter && SDecl->getInstanceMethod(Prop->getGetterName()))
        SuperClassImplementsGetter = true;
  
      if (!SuperClassImplementsSetter && SDecl->getInstanceMethod(Prop->getSetterName()))
        SuperClassImplementsSetter = true;
      if (SuperClassImplementsGetter && SuperClassImplementsSetter)
        return true;
      IDecl = IDecl->getSuperClass();
    }
    return false;
  }
  
  /// Default synthesizes all properties which must be synthesized
  /// in class's \@implementation.
  void Sema::DefaultSynthesizeProperties(Scope *S, ObjCImplDecl *IMPDecl,
                                         ObjCInterfaceDecl *IDecl,
                                         SourceLocation AtEnd) {
    ObjCInterfaceDecl::PropertyMap PropMap;
    ObjCInterfaceDecl::PropertyDeclOrder PropertyOrder;
    IDecl->collectPropertiesToImplement(PropMap, PropertyOrder);
    if (PropMap.empty())
      return;
    ObjCInterfaceDecl::PropertyMap SuperPropMap;
    CollectSuperClassPropertyImplementations(IDecl, SuperPropMap);
  
    for (unsigned i = 0, e = PropertyOrder.size(); i != e; i++) {
      ObjCPropertyDecl *Prop = PropertyOrder[i];
      // Is there a matching property synthesize/dynamic?
      if (Prop->isInvalidDecl() ||
          Prop->isClassProperty() ||
          Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional)
        continue;
      // Property may have been synthesized by user.
      if (IMPDecl->FindPropertyImplDecl(
              Prop->getIdentifier(), Prop->getQueryKind()))
        continue;
      if (IMPDecl->getInstanceMethod(Prop->getGetterName())) {
        if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
          continue;
        if (IMPDecl->getInstanceMethod(Prop->getSetterName()))
          continue;
      }
      if (ObjCPropertyImplDecl *PID =
          IMPDecl->FindPropertyImplIvarDecl(Prop->getIdentifier())) {
        Diag(Prop->getLocation(), diag::warn_no_autosynthesis_shared_ivar_property)
          << Prop->getIdentifier();
        if (PID->getLocation().isValid())
          Diag(PID->getLocation(), diag::note_property_synthesize);
        continue;
      }
      ObjCPropertyDecl *PropInSuperClass =
          SuperPropMap[std::make_pair(Prop->getIdentifier(),
                                      Prop->isClassProperty())];
      if (ObjCProtocolDecl *Proto =
            dyn_cast<ObjCProtocolDecl>(Prop->getDeclContext())) {
        // We won't auto-synthesize properties declared in protocols.
        // Suppress the warning if class's superclass implements property's
        // getter and implements property's setter (if readwrite property).
        // Or, if property is going to be implemented in its super class.
        if (!SuperClassImplementsProperty(IDecl, Prop) && !PropInSuperClass) {
          Diag(IMPDecl->getLocation(),
               diag::warn_auto_synthesizing_protocol_property)
            << Prop << Proto;
          Diag(Prop->getLocation(), diag::note_property_declare);
          std::string FixIt =
              (Twine("@synthesize ") + Prop->getName() + ";\n\n").str();
          Diag(AtEnd, diag::note_add_synthesize_directive)
              << FixItHint::CreateInsertion(AtEnd, FixIt);
        }
        continue;
      }
      // If property to be implemented in the super class, ignore.
      if (PropInSuperClass) {
        if ((Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readwrite) &&
            (PropInSuperClass->getPropertyAttributes() &
             ObjCPropertyDecl::OBJC_PR_readonly) &&
            !IMPDecl->getInstanceMethod(Prop->getSetterName()) &&
            !IDecl->HasUserDeclaredSetterMethod(Prop)) {
          Diag(Prop->getLocation(), diag::warn_no_autosynthesis_property)
          << Prop->getIdentifier();
          Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
        }
        else {
          Diag(Prop->getLocation(), diag::warn_autosynthesis_property_in_superclass)
          << Prop->getIdentifier();
          Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
          Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
        }
        continue;
      }
      // We use invalid SourceLocations for the synthesized ivars since they
      // aren't really synthesized at a particular location; they just exist.
      // Saying that they are located at the @implementation isn't really going
      // to help users.
      ObjCPropertyImplDecl *PIDecl = dyn_cast_or_null<ObjCPropertyImplDecl>(
        ActOnPropertyImplDecl(S, SourceLocation(), SourceLocation(),
                              true,
                              /* property = */ Prop->getIdentifier(),
                              /* ivar = */ Prop->getDefaultSynthIvarName(Context),
                              Prop->getLocation(), Prop->getQueryKind()));
      if (PIDecl && !Prop->isUnavailable()) {
        Diag(Prop->getLocation(), diag::warn_missing_explicit_synthesis);
        Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
      }
    }
  }
  
  void Sema::DefaultSynthesizeProperties(Scope *S, Decl *D,
                                         SourceLocation AtEnd) {
    if (!LangOpts.ObjCDefaultSynthProperties || LangOpts.ObjCRuntime.isFragile())
      return;
    ObjCImplementationDecl *IC=dyn_cast_or_null<ObjCImplementationDecl>(D);
    if (!IC)
      return;
    if (ObjCInterfaceDecl* IDecl = IC->getClassInterface())
      if (!IDecl->isObjCRequiresPropertyDefs())
        DefaultSynthesizeProperties(S, IC, IDecl, AtEnd);
  }
  
  static void DiagnoseUnimplementedAccessor(
      Sema &S, ObjCInterfaceDecl *PrimaryClass, Selector Method,
      ObjCImplDecl *IMPDecl, ObjCContainerDecl *CDecl, ObjCCategoryDecl *C,
      ObjCPropertyDecl *Prop,
      llvm::SmallPtrSet<const ObjCMethodDecl *, 8> &SMap) {
    // Check to see if we have a corresponding selector in SMap and with the
    // right method type.
    auto I = std::find_if(SMap.begin(), SMap.end(),
      [&](const ObjCMethodDecl *x) {
        return x->getSelector() == Method &&
               x->isClassMethod() == Prop->isClassProperty();
      });
    // When reporting on missing property setter/getter implementation in
    // categories, do not report when they are declared in primary class,
    // class's protocol, or one of it super classes. This is because,
    // the class is going to implement them.
    if (I == SMap.end() &&
        (PrimaryClass == nullptr ||
         !PrimaryClass->lookupPropertyAccessor(Method, C,
                                               Prop->isClassProperty()))) {
      unsigned diag =
          isa<ObjCCategoryDecl>(CDecl)
              ? (Prop->isClassProperty()
                     ? diag::warn_impl_required_in_category_for_class_property
                     : diag::warn_setter_getter_impl_required_in_category)
              : (Prop->isClassProperty()
                     ? diag::warn_impl_required_for_class_property
                     : diag::warn_setter_getter_impl_required);
      S.Diag(IMPDecl->getLocation(), diag) << Prop->getDeclName() << Method;
      S.Diag(Prop->getLocation(), diag::note_property_declare);
      if (S.LangOpts.ObjCDefaultSynthProperties &&
          S.LangOpts.ObjCRuntime.isNonFragile())
        if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CDecl))
          if (const ObjCInterfaceDecl *RID = ID->isObjCRequiresPropertyDefs())
            S.Diag(RID->getLocation(), diag::note_suppressed_class_declare);
    }
  }
  
  void Sema::DiagnoseUnimplementedProperties(Scope *S, ObjCImplDecl* IMPDecl,
                                             ObjCContainerDecl *CDecl,
                                             bool SynthesizeProperties) {
    ObjCContainerDecl::PropertyMap PropMap;
    ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl);
  
    // Since we don't synthesize class properties, we should emit diagnose even
    // if SynthesizeProperties is true.
    ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
    // Gather properties which need not be implemented in this class
    // or category.
    if (!IDecl)
      if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl)) {
        // For categories, no need to implement properties declared in
        // its primary class (and its super classes) if property is
        // declared in one of those containers.
        if ((IDecl = C->getClassInterface())) {
          ObjCInterfaceDecl::PropertyDeclOrder PO;
          IDecl->collectPropertiesToImplement(NoNeedToImplPropMap, PO);
        }
      }
    if (IDecl)
      CollectSuperClassPropertyImplementations(IDecl, NoNeedToImplPropMap);
  
    // When SynthesizeProperties is true, we only check class properties.
    CollectImmediateProperties(CDecl, PropMap, NoNeedToImplPropMap,
                               SynthesizeProperties/*CollectClassPropsOnly*/);
  
    // Scan the @interface to see if any of the protocols it adopts
    // require an explicit implementation, via attribute
    // 'objc_protocol_requires_explicit_implementation'.
    if (IDecl) {
      std::unique_ptr<ObjCContainerDecl::PropertyMap> LazyMap;
  
      for (auto *PDecl : IDecl->all_referenced_protocols()) {
        if (!PDecl->hasAttr<ObjCExplicitProtocolImplAttr>())
          continue;
        // Lazily construct a set of all the properties in the @interface
        // of the class, without looking at the superclass.  We cannot
        // use the call to CollectImmediateProperties() above as that
        // utilizes information from the super class's properties as well
        // as scans the adopted protocols.  This work only triggers for protocols
        // with the attribute, which is very rare, and only occurs when
        // analyzing the @implementation.
        if (!LazyMap) {
          ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
          LazyMap.reset(new ObjCContainerDecl::PropertyMap());
          CollectImmediateProperties(CDecl, *LazyMap, NoNeedToImplPropMap,
                                     /* CollectClassPropsOnly */ false,
                                     /* IncludeProtocols */ false);
        }
        // Add the properties of 'PDecl' to the list of properties that
        // need to be implemented.
        for (auto *PropDecl : PDecl->properties()) {
          if ((*LazyMap)[std::make_pair(PropDecl->getIdentifier(),
                                        PropDecl->isClassProperty())])
            continue;
          PropMap[std::make_pair(PropDecl->getIdentifier(),
                                 PropDecl->isClassProperty())] = PropDecl;
        }
      }
    }
  
    if (PropMap.empty())
      return;
  
    llvm::DenseSet<ObjCPropertyDecl *> PropImplMap;
    for (const auto *I : IMPDecl->property_impls())
      PropImplMap.insert(I->getPropertyDecl());
  
    llvm::SmallPtrSet<const ObjCMethodDecl *, 8> InsMap;
    // Collect property accessors implemented in current implementation.
    for (const auto *I : IMPDecl->methods())
      InsMap.insert(I);
  
    ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl);
    ObjCInterfaceDecl *PrimaryClass = nullptr;
    if (C && !C->IsClassExtension())
      if ((PrimaryClass = C->getClassInterface()))
        // Report unimplemented properties in the category as well.
        if (ObjCImplDecl *IMP = PrimaryClass->getImplementation()) {
          // When reporting on missing setter/getters, do not report when
          // setter/getter is implemented in category's primary class
          // implementation.
          for (const auto *I : IMP->methods())
            InsMap.insert(I);
        }
  
    for (ObjCContainerDecl::PropertyMap::iterator
         P = PropMap.begin(), E = PropMap.end(); P != E; ++P) {
      ObjCPropertyDecl *Prop = P->second;
      // Is there a matching property synthesize/dynamic?
      if (Prop->isInvalidDecl() ||
          Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional ||
          PropImplMap.count(Prop) ||
          Prop->getAvailability() == AR_Unavailable)
        continue;
  
      // Diagnose unimplemented getters and setters.
      DiagnoseUnimplementedAccessor(*this,
            PrimaryClass, Prop->getGetterName(), IMPDecl, CDecl, C, Prop, InsMap);
      if (!Prop->isReadOnly())
        DiagnoseUnimplementedAccessor(*this,
                                      PrimaryClass, Prop->getSetterName(),
                                      IMPDecl, CDecl, C, Prop, InsMap);
    }
  }
  
  void Sema::diagnoseNullResettableSynthesizedSetters(const ObjCImplDecl *impDecl) {
    for (const auto *propertyImpl : impDecl->property_impls()) {
      const auto *property = propertyImpl->getPropertyDecl();
  
      // Warn about null_resettable properties with synthesized setters,
      // because the setter won't properly handle nil.
      if (propertyImpl->getPropertyImplementation()
            == ObjCPropertyImplDecl::Synthesize &&
          (property->getPropertyAttributes() &
           ObjCPropertyDecl::OBJC_PR_null_resettable) &&
          property->getGetterMethodDecl() &&
          property->getSetterMethodDecl()) {
        auto *getterMethod = property->getGetterMethodDecl();
        auto *setterMethod = property->getSetterMethodDecl();
        if (!impDecl->getInstanceMethod(setterMethod->getSelector()) &&
            !impDecl->getInstanceMethod(getterMethod->getSelector())) {
          SourceLocation loc = propertyImpl->getLocation();
          if (loc.isInvalid())
            loc = impDecl->getBeginLoc();
  
          Diag(loc, diag::warn_null_resettable_setter)
            << setterMethod->getSelector() << property->getDeclName();
        }
      }
    }
  }
  
  void
  Sema::AtomicPropertySetterGetterRules (ObjCImplDecl* IMPDecl,
                                         ObjCInterfaceDecl* IDecl) {
    // Rules apply in non-GC mode only
    if (getLangOpts().getGC() != LangOptions::NonGC)
      return;
    ObjCContainerDecl::PropertyMap PM;
    for (auto *Prop : IDecl->properties())
      PM[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] = Prop;
    for (const auto *Ext : IDecl->known_extensions())
      for (auto *Prop : Ext->properties())
        PM[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] = Prop;
  
    for (ObjCContainerDecl::PropertyMap::iterator I = PM.begin(), E = PM.end();
         I != E; ++I) {
      const ObjCPropertyDecl *Property = I->second;
      ObjCMethodDecl *GetterMethod = nullptr;
      ObjCMethodDecl *SetterMethod = nullptr;
      bool LookedUpGetterSetter = false;
  
      unsigned Attributes = Property->getPropertyAttributes();
      unsigned AttributesAsWritten = Property->getPropertyAttributesAsWritten();
  
      if (!(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_atomic) &&
          !(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_nonatomic)) {
        GetterMethod = Property->isClassProperty() ?
                       IMPDecl->getClassMethod(Property->getGetterName()) :
                       IMPDecl->getInstanceMethod(Property->getGetterName());
        SetterMethod = Property->isClassProperty() ?
                       IMPDecl->getClassMethod(Property->getSetterName()) :
                       IMPDecl->getInstanceMethod(Property->getSetterName());
        LookedUpGetterSetter = true;
        if (GetterMethod) {
          Diag(GetterMethod->getLocation(),
               diag::warn_default_atomic_custom_getter_setter)
            << Property->getIdentifier() << 0;
          Diag(Property->getLocation(), diag::note_property_declare);
        }
        if (SetterMethod) {
          Diag(SetterMethod->getLocation(),
               diag::warn_default_atomic_custom_getter_setter)
            << Property->getIdentifier() << 1;
          Diag(Property->getLocation(), diag::note_property_declare);
        }
      }
  
      // We only care about readwrite atomic property.
      if ((Attributes & ObjCPropertyDecl::OBJC_PR_nonatomic) ||
          !(Attributes & ObjCPropertyDecl::OBJC_PR_readwrite))
        continue;
      if (const ObjCPropertyImplDecl *PIDecl = IMPDecl->FindPropertyImplDecl(
              Property->getIdentifier(), Property->getQueryKind())) {
        if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic)
          continue;
        if (!LookedUpGetterSetter) {
          GetterMethod = Property->isClassProperty() ?
                         IMPDecl->getClassMethod(Property->getGetterName()) :
                         IMPDecl->getInstanceMethod(Property->getGetterName());
          SetterMethod = Property->isClassProperty() ?
                         IMPDecl->getClassMethod(Property->getSetterName()) :
                         IMPDecl->getInstanceMethod(Property->getSetterName());
        }
        if ((GetterMethod && !SetterMethod) || (!GetterMethod && SetterMethod)) {
          SourceLocation MethodLoc =
            (GetterMethod ? GetterMethod->getLocation()
                          : SetterMethod->getLocation());
          Diag(MethodLoc, diag::warn_atomic_property_rule)
            << Property->getIdentifier() << (GetterMethod != nullptr)
            << (SetterMethod != nullptr);
          // fixit stuff.
          if (Property->getLParenLoc().isValid() &&
              !(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_atomic)) {
            // @property () ... case.
            SourceLocation AfterLParen =
              getLocForEndOfToken(Property->getLParenLoc());
            StringRef NonatomicStr = AttributesAsWritten? "nonatomic, "
                                                        : "nonatomic";
            Diag(Property->getLocation(),
                 diag::note_atomic_property_fixup_suggest)
              << FixItHint::CreateInsertion(AfterLParen, NonatomicStr);
          } else if (Property->getLParenLoc().isInvalid()) {
            //@property id etc.
            SourceLocation startLoc =
              Property->getTypeSourceInfo()->getTypeLoc().getBeginLoc();
            Diag(Property->getLocation(),
                 diag::note_atomic_property_fixup_suggest)
              << FixItHint::CreateInsertion(startLoc, "(nonatomic) ");
          }
          else
            Diag(MethodLoc, diag::note_atomic_property_fixup_suggest);
          Diag(Property->getLocation(), diag::note_property_declare);
        }
      }
    }
  }
  
  void Sema::DiagnoseOwningPropertyGetterSynthesis(const ObjCImplementationDecl *D) {
    if (getLangOpts().getGC() == LangOptions::GCOnly)
      return;
  
    for (const auto *PID : D->property_impls()) {
      const ObjCPropertyDecl *PD = PID->getPropertyDecl();
      if (PD && !PD->hasAttr<NSReturnsNotRetainedAttr>() &&
          !PD->isClassProperty() &&
          !D->getInstanceMethod(PD->getGetterName())) {
        ObjCMethodDecl *method = PD->getGetterMethodDecl();
        if (!method)
          continue;
        ObjCMethodFamily family = method->getMethodFamily();
        if (family == OMF_alloc || family == OMF_copy ||
            family == OMF_mutableCopy || family == OMF_new) {
          if (getLangOpts().ObjCAutoRefCount)
            Diag(PD->getLocation(), diag::err_cocoa_naming_owned_rule);
          else
            Diag(PD->getLocation(), diag::warn_cocoa_naming_owned_rule);
  
          // Look for a getter explicitly declared alongside the property.
          // If we find one, use its location for the note.
          SourceLocation noteLoc = PD->getLocation();
          SourceLocation fixItLoc;
          for (auto *getterRedecl : method->redecls()) {
            if (getterRedecl->isImplicit())
              continue;
            if (getterRedecl->getDeclContext() != PD->getDeclContext())
              continue;
            noteLoc = getterRedecl->getLocation();
            fixItLoc = getterRedecl->getEndLoc();
          }
  
          Preprocessor &PP = getPreprocessor();
          TokenValue tokens[] = {
            tok::kw___attribute, tok::l_paren, tok::l_paren,
            PP.getIdentifierInfo("objc_method_family"), tok::l_paren,
            PP.getIdentifierInfo("none"), tok::r_paren,
            tok::r_paren, tok::r_paren
          };
          StringRef spelling = "__attribute__((objc_method_family(none)))";
          StringRef macroName = PP.getLastMacroWithSpelling(noteLoc, tokens);
          if (!macroName.empty())
            spelling = macroName;
  
          auto noteDiag = Diag(noteLoc, diag::note_cocoa_naming_declare_family)
              << method->getDeclName() << spelling;
          if (fixItLoc.isValid()) {
            SmallString<64> fixItText(" ");
            fixItText += spelling;
            noteDiag << FixItHint::CreateInsertion(fixItLoc, fixItText);
          }
        }
      }
    }
  }
  
  void Sema::DiagnoseMissingDesignatedInitOverrides(
                                              const ObjCImplementationDecl *ImplD,
                                              const ObjCInterfaceDecl *IFD) {
    assert(IFD->hasDesignatedInitializers());
    const ObjCInterfaceDecl *SuperD = IFD->getSuperClass();
    if (!SuperD)
      return;
  
    SelectorSet InitSelSet;
    for (const auto *I : ImplD->instance_methods())
      if (I->getMethodFamily() == OMF_init)
        InitSelSet.insert(I->getSelector());
  
    SmallVector<const ObjCMethodDecl *, 8> DesignatedInits;
    SuperD->getDesignatedInitializers(DesignatedInits);
    for (SmallVector<const ObjCMethodDecl *, 8>::iterator
           I = DesignatedInits.begin(), E = DesignatedInits.end(); I != E; ++I) {
      const ObjCMethodDecl *MD = *I;
      if (!InitSelSet.count(MD->getSelector())) {
        bool Ignore = false;
        if (auto *IMD = IFD->getInstanceMethod(MD->getSelector())) {
          Ignore = IMD->isUnavailable();
        }
        if (!Ignore) {
          Diag(ImplD->getLocation(),
               diag::warn_objc_implementation_missing_designated_init_override)
            << MD->getSelector();
          Diag(MD->getLocation(), diag::note_objc_designated_init_marked_here);
        }
      }
    }
  }
  
  /// AddPropertyAttrs - Propagates attributes from a property to the
  /// implicitly-declared getter or setter for that property.
  static void AddPropertyAttrs(Sema &S, ObjCMethodDecl *PropertyMethod,
                               ObjCPropertyDecl *Property) {
    // Should we just clone all attributes over?
    for (const auto *A : Property->attrs()) {
      if (isa<DeprecatedAttr>(A) ||
          isa<UnavailableAttr>(A) ||
          isa<AvailabilityAttr>(A))
        PropertyMethod->addAttr(A->clone(S.Context));
    }
  }
  
  /// ProcessPropertyDecl - Make sure that any user-defined setter/getter methods
  /// have the property type and issue diagnostics if they don't.
  /// Also synthesize a getter/setter method if none exist (and update the
  /// appropriate lookup tables.
  void Sema::ProcessPropertyDecl(ObjCPropertyDecl *property) {
    ObjCMethodDecl *GetterMethod, *SetterMethod;
    ObjCContainerDecl *CD = cast<ObjCContainerDecl>(property->getDeclContext());
    if (CD->isInvalidDecl())
      return;
  
    bool IsClassProperty = property->isClassProperty();
    GetterMethod = IsClassProperty ?
      CD->getClassMethod(property->getGetterName()) :
      CD->getInstanceMethod(property->getGetterName());
  
    // if setter or getter is not found in class extension, it might be
    // in the primary class.
    if (!GetterMethod)
      if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD))
        if (CatDecl->IsClassExtension())
          GetterMethod = IsClassProperty ? CatDecl->getClassInterface()->
                           getClassMethod(property->getGetterName()) :
                         CatDecl->getClassInterface()->
                           getInstanceMethod(property->getGetterName());
  
    SetterMethod = IsClassProperty ?
                   CD->getClassMethod(property->getSetterName()) :
                   CD->getInstanceMethod(property->getSetterName());
    if (!SetterMethod)
      if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD))
        if (CatDecl->IsClassExtension())
          SetterMethod = IsClassProperty ? CatDecl->getClassInterface()->
                            getClassMethod(property->getSetterName()) :
                         CatDecl->getClassInterface()->
                            getInstanceMethod(property->getSetterName());
    DiagnosePropertyAccessorMismatch(property, GetterMethod,
                                     property->getLocation());
  
    if (!property->isReadOnly() && SetterMethod) {
      if (Context.getCanonicalType(SetterMethod->getReturnType()) !=
          Context.VoidTy)
        Diag(SetterMethod->getLocation(), diag::err_setter_type_void);
      if (SetterMethod->param_size() != 1 ||
          !Context.hasSameUnqualifiedType(
            (*SetterMethod->param_begin())->getType().getNonReferenceType(),
            property->getType().getNonReferenceType())) {
        Diag(property->getLocation(),
             diag::warn_accessor_property_type_mismatch)
          << property->getDeclName()
          << SetterMethod->getSelector();
        Diag(SetterMethod->getLocation(), diag::note_declared_at);
      }
    }
  
    // Synthesize getter/setter methods if none exist.
    // Find the default getter and if one not found, add one.
    // FIXME: The synthesized property we set here is misleading. We almost always
    // synthesize these methods unless the user explicitly provided prototypes
    // (which is odd, but allowed). Sema should be typechecking that the
    // declarations jive in that situation (which it is not currently).
    if (!GetterMethod) {
      // No instance/class method of same name as property getter name was found.
      // Declare a getter method and add it to the list of methods
      // for this class.
      SourceLocation Loc = property->getLocation();
  
      // The getter returns the declared property type with all qualifiers
      // removed.
      QualType resultTy = property->getType().getAtomicUnqualifiedType();
  
      // If the property is null_resettable, the getter returns nonnull.
      if (property->getPropertyAttributes() &
          ObjCPropertyDecl::OBJC_PR_null_resettable) {
        QualType modifiedTy = resultTy;
        if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)) {
          if (*nullability == NullabilityKind::Unspecified)
            resultTy = Context.getAttributedType(attr::TypeNonNull,
                                                 modifiedTy, modifiedTy);
        }
      }
  
      GetterMethod = ObjCMethodDecl::Create(Context, Loc, Loc,
                               property->getGetterName(),
                               resultTy, nullptr, CD,
                               !IsClassProperty, /*isVariadic=*/false,
                               /*isPropertyAccessor=*/true,
                               /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
                               (property->getPropertyImplementation() ==
                                ObjCPropertyDecl::Optional) ?
                               ObjCMethodDecl::Optional :
                               ObjCMethodDecl::Required);
      CD->addDecl(GetterMethod);
  
      AddPropertyAttrs(*this, GetterMethod, property);
  
      if (property->hasAttr<NSReturnsNotRetainedAttr>())
        GetterMethod->addAttr(NSReturnsNotRetainedAttr::CreateImplicit(Context,
                                                                       Loc));
  
      if (property->hasAttr<ObjCReturnsInnerPointerAttr>())
        GetterMethod->addAttr(
          ObjCReturnsInnerPointerAttr::CreateImplicit(Context, Loc));
  
      if (const SectionAttr *SA = property->getAttr<SectionAttr>())
        GetterMethod->addAttr(
            SectionAttr::CreateImplicit(Context, SectionAttr::GNU_section,
                                        SA->getName(), Loc));
  
      if (getLangOpts().ObjCAutoRefCount)
        CheckARCMethodDecl(GetterMethod);
    } else
      // A user declared getter will be synthesize when @synthesize of
      // the property with the same name is seen in the @implementation
      GetterMethod->setPropertyAccessor(true);
    property->setGetterMethodDecl(GetterMethod);
  
    // Skip setter if property is read-only.
    if (!property->isReadOnly()) {
      // Find the default setter and if one not found, add one.
      if (!SetterMethod) {
        // No instance/class method of same name as property setter name was
        // found.
        // Declare a setter method and add it to the list of methods
        // for this class.
        SourceLocation Loc = property->getLocation();
  
        SetterMethod =
          ObjCMethodDecl::Create(Context, Loc, Loc,
                                 property->getSetterName(), Context.VoidTy,
                                 nullptr, CD, !IsClassProperty,
                                 /*isVariadic=*/false,
                                 /*isPropertyAccessor=*/true,
                                 /*isImplicitlyDeclared=*/true,
                                 /*isDefined=*/false,
                                 (property->getPropertyImplementation() ==
                                  ObjCPropertyDecl::Optional) ?
                                  ObjCMethodDecl::Optional :
                                  ObjCMethodDecl::Required);
  
        // Remove all qualifiers from the setter's parameter type.
        QualType paramTy =
            property->getType().getUnqualifiedType().getAtomicUnqualifiedType();
  
        // If the property is null_resettable, the setter accepts a
        // nullable value.
        if (property->getPropertyAttributes() &
            ObjCPropertyDecl::OBJC_PR_null_resettable) {
          QualType modifiedTy = paramTy;
          if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)){
            if (*nullability == NullabilityKind::Unspecified)
              paramTy = Context.getAttributedType(attr::TypeNullable,
                                                  modifiedTy, modifiedTy);
          }
        }
  
        // Invent the arguments for the setter. We don't bother making a
        // nice name for the argument.
        ParmVarDecl *Argument = ParmVarDecl::Create(Context, SetterMethod,
                                                    Loc, Loc,
                                                    property->getIdentifier(),
                                                    paramTy,
                                                    /*TInfo=*/nullptr,
                                                    SC_None,
                                                    nullptr);
        SetterMethod->setMethodParams(Context, Argument, None);
  
        AddPropertyAttrs(*this, SetterMethod, property);
  
        CD->addDecl(SetterMethod);
        if (const SectionAttr *SA = property->getAttr<SectionAttr>())
          SetterMethod->addAttr(
              SectionAttr::CreateImplicit(Context, SectionAttr::GNU_section,
                                          SA->getName(), Loc));
        // It's possible for the user to have set a very odd custom
        // setter selector that causes it to have a method family.
        if (getLangOpts().ObjCAutoRefCount)
          CheckARCMethodDecl(SetterMethod);
      } else
        // A user declared setter will be synthesize when @synthesize of
        // the property with the same name is seen in the @implementation
        SetterMethod->setPropertyAccessor(true);
      property->setSetterMethodDecl(SetterMethod);
    }
    // Add any synthesized methods to the global pool. This allows us to
    // handle the following, which is supported by GCC (and part of the design).
    //
    // @interface Foo
    // @property double bar;
    // @end
    //
    // void thisIsUnfortunate() {
    //   id foo;
    //   double bar = [foo bar];
    // }
    //
    if (!IsClassProperty) {
      if (GetterMethod)
        AddInstanceMethodToGlobalPool(GetterMethod);
      if (SetterMethod)
        AddInstanceMethodToGlobalPool(SetterMethod);
    } else {
      if (GetterMethod)
        AddFactoryMethodToGlobalPool(GetterMethod);
      if (SetterMethod)
        AddFactoryMethodToGlobalPool(SetterMethod);
    }
  
    ObjCInterfaceDecl *CurrentClass = dyn_cast<ObjCInterfaceDecl>(CD);
    if (!CurrentClass) {
      if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(CD))
        CurrentClass = Cat->getClassInterface();
      else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(CD))
        CurrentClass = Impl->getClassInterface();
    }
    if (GetterMethod)
      CheckObjCMethodOverrides(GetterMethod, CurrentClass, Sema::RTC_Unknown);
    if (SetterMethod)
      CheckObjCMethodOverrides(SetterMethod, CurrentClass, Sema::RTC_Unknown);
  }
  
  void Sema::CheckObjCPropertyAttributes(Decl *PDecl,
                                         SourceLocation Loc,
                                         unsigned &Attributes,
                                         bool propertyInPrimaryClass) {
    // FIXME: Improve the reported location.
    if (!PDecl || PDecl->isInvalidDecl())
      return;
  
    if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
        (Attributes & ObjCDeclSpec::DQ_PR_readwrite))
      Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
      << "readonly" << "readwrite";
  
    ObjCPropertyDecl *PropertyDecl = cast<ObjCPropertyDecl>(PDecl);
    QualType PropertyTy = PropertyDecl->getType();
  
    // Check for copy or retain on non-object types.
    if ((Attributes & (ObjCDeclSpec::DQ_PR_weak | ObjCDeclSpec::DQ_PR_copy |
                      ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong)) &&
        !PropertyTy->isObjCRetainableType() &&
        !PropertyDecl->hasAttr<ObjCNSObjectAttr>()) {
      Diag(Loc, diag::err_objc_property_requires_object)
        << (Attributes & ObjCDeclSpec::DQ_PR_weak ? "weak" :
            Attributes & ObjCDeclSpec::DQ_PR_copy ? "copy" : "retain (or strong)");
      Attributes &= ~(ObjCDeclSpec::DQ_PR_weak   | ObjCDeclSpec::DQ_PR_copy |
                      ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong);
      PropertyDecl->setInvalidDecl();
    }
  
    // Check for assign on object types.
    if ((Attributes & ObjCDeclSpec::DQ_PR_assign) &&
        !(Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) &&
        PropertyTy->isObjCRetainableType() &&
        !PropertyTy->isObjCARCImplicitlyUnretainedType()) {
      Diag(Loc, diag::warn_objc_property_assign_on_object);
    }
  
    // Check for more than one of { assign, copy, retain }.
    if (Attributes & ObjCDeclSpec::DQ_PR_assign) {
      if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "assign" << "copy";
        Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
      }
      if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "assign" << "retain";
        Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
      }
      if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "assign" << "strong";
        Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
      }
      if (getLangOpts().ObjCAutoRefCount  &&
          (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "assign" << "weak";
        Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
      }
      if (PropertyDecl->hasAttr<IBOutletCollectionAttr>())
        Diag(Loc, diag::warn_iboutletcollection_property_assign);
    } else if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) {
      if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "unsafe_unretained" << "copy";
        Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
      }
      if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "unsafe_unretained" << "retain";
        Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
      }
      if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "unsafe_unretained" << "strong";
        Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
      }
      if (getLangOpts().ObjCAutoRefCount  &&
          (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "unsafe_unretained" << "weak";
        Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
      }
    } else if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
      if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "copy" << "retain";
        Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
      }
      if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "copy" << "strong";
        Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
      }
      if (Attributes & ObjCDeclSpec::DQ_PR_weak) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "copy" << "weak";
        Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
      }
    }
    else if ((Attributes & ObjCDeclSpec::DQ_PR_retain) &&
             (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "retain" << "weak";
        Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
    }
    else if ((Attributes & ObjCDeclSpec::DQ_PR_strong) &&
             (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "strong" << "weak";
        Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
    }
  
    if (Attributes & ObjCDeclSpec::DQ_PR_weak) {
      // 'weak' and 'nonnull' are mutually exclusive.
      if (auto nullability = PropertyTy->getNullability(Context)) {
        if (*nullability == NullabilityKind::NonNull)
          Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
            << "nonnull" << "weak";
      }
    }
  
    if ((Attributes & ObjCDeclSpec::DQ_PR_atomic) &&
        (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)) {
        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
          << "atomic" << "nonatomic";
        Attributes &= ~ObjCDeclSpec::DQ_PR_atomic;
    }
  
    // Warn if user supplied no assignment attribute, property is
    // readwrite, and this is an object type.
    if (!getOwnershipRule(Attributes) && PropertyTy->isObjCRetainableType()) {
      if (Attributes & ObjCDeclSpec::DQ_PR_readonly) {
        // do nothing
      } else if (getLangOpts().ObjCAutoRefCount) {
        // With arc, @property definitions should default to strong when
        // not specified.
        PropertyDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
      } else if (PropertyTy->isObjCObjectPointerType()) {
          bool isAnyClassTy =
            (PropertyTy->isObjCClassType() ||
             PropertyTy->isObjCQualifiedClassType());
          // In non-gc, non-arc mode, 'Class' is treated as a 'void *' no need to
          // issue any warning.
          if (isAnyClassTy && getLangOpts().getGC() == LangOptions::NonGC)
            ;
          else if (propertyInPrimaryClass) {
            // Don't issue warning on property with no life time in class
            // extension as it is inherited from property in primary class.
            // Skip this warning in gc-only mode.
            if (getLangOpts().getGC() != LangOptions::GCOnly)
              Diag(Loc, diag::warn_objc_property_no_assignment_attribute);
  
            // If non-gc code warn that this is likely inappropriate.
            if (getLangOpts().getGC() == LangOptions::NonGC)
              Diag(Loc, diag::warn_objc_property_default_assign_on_object);
          }
      }
  
      // FIXME: Implement warning dependent on NSCopying being
      // implemented. See also:
      // <rdar://5168496&4855821&5607453&5096644&4947311&5698469&4947014&5168496>
      // (please trim this list while you are at it).
    }
  
    if (!(Attributes & ObjCDeclSpec::DQ_PR_copy)
        &&!(Attributes & ObjCDeclSpec::DQ_PR_readonly)
        && getLangOpts().getGC() == LangOptions::GCOnly
        && PropertyTy->isBlockPointerType())
      Diag(Loc, diag::warn_objc_property_copy_missing_on_block);
    else if ((Attributes & ObjCDeclSpec::DQ_PR_retain) &&
             !(Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
             !(Attributes & ObjCDeclSpec::DQ_PR_strong) &&
             PropertyTy->isBlockPointerType())
        Diag(Loc, diag::warn_objc_property_retain_of_block);
  
    if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
        (Attributes & ObjCDeclSpec::DQ_PR_setter))
      Diag(Loc, diag::warn_objc_readonly_property_has_setter);
  }
  