diff --git a/clang/include/clang/AST/DeclBase.h b/clang/include/clang/AST/DeclBase.h
index 01c2f1809771b..adea10b33188b 100644
--- a/clang/include/clang/AST/DeclBase.h
+++ b/clang/include/clang/AST/DeclBase.h
@@ -1590,6 +1590,9 @@ class DeclContext {
     /// True if this method is the getter or setter for an explicit property.
     uint64_t IsPropertyAccessor : 1;
 
+    /// True if this method is a synthesized property accessor stub.
+    uint64_t IsSynthesizedAccessorStub : 1;
+
     /// Method has a definition.
     uint64_t IsDefined : 1;
 
diff --git a/clang/include/clang/AST/DeclObjC.h b/clang/include/clang/AST/DeclObjC.h
index 8d85ac36d8611..e5d3ebfadc06b 100644
--- a/clang/include/clang/AST/DeclObjC.h
+++ b/clang/include/clang/AST/DeclObjC.h
@@ -172,6 +172,7 @@ class ObjCMethodDecl : public NamedDecl, public DeclContext {
                  Selector SelInfo, QualType T, TypeSourceInfo *ReturnTInfo,
                  DeclContext *contextDecl, bool isInstance = true,
                  bool isVariadic = false, bool isPropertyAccessor = false,
+                 bool isSynthesizedAccessorStub = false, 
                  bool isImplicitlyDeclared = false, bool isDefined = false,
                  ImplementationControl impControl = None,
                  bool HasRelatedResultType = false);
@@ -232,6 +233,7 @@ class ObjCMethodDecl : public NamedDecl, public DeclContext {
          Selector SelInfo, QualType T, TypeSourceInfo *ReturnTInfo,
          DeclContext *contextDecl, bool isInstance = true,
          bool isVariadic = false, bool isPropertyAccessor = false,
+         bool isSynthesizedAccessorStub = false,
          bool isImplicitlyDeclared = false, bool isDefined = false,
          ImplementationControl impControl = None,
          bool HasRelatedResultType = false);
@@ -436,6 +438,14 @@ class ObjCMethodDecl : public NamedDecl, public DeclContext {
     ObjCMethodDeclBits.IsPropertyAccessor = isAccessor;
   }
 
+  bool isSynthesizedAccessorStub() const {
+    return ObjCMethodDeclBits.IsSynthesizedAccessorStub;
+  }
+
+  void setSynthesizedAccessorStub(bool isSynthesizedAccessorStub) {
+    ObjCMethodDeclBits.IsSynthesizedAccessorStub = isSynthesizedAccessorStub;
+  }
+
   bool isDefined() const { return ObjCMethodDeclBits.IsDefined; }
   void setDefined(bool isDefined) { ObjCMethodDeclBits.IsDefined = isDefined; }
 
@@ -2779,6 +2789,11 @@ class ObjCPropertyImplDecl : public Decl {
   /// Null for \@dynamic. Required for \@synthesize.
   ObjCIvarDecl *PropertyIvarDecl;
 
+  /// The getter's definition, which has an empty body if synthesized.
+  ObjCMethodDecl *GetterMethodDecl = nullptr;
+  /// The getter's definition, which has an empty body if synthesized.
+  ObjCMethodDecl *SetterMethodDecl = nullptr;
+
   /// Null for \@dynamic. Non-null if property must be copy-constructed in
   /// getter.
   Expr *GetterCXXConstructor = nullptr;
@@ -2845,6 +2860,12 @@ class ObjCPropertyImplDecl : public Decl {
     return IvarLoc.isValid() && IvarLoc != getLocation();
   }
 
+  ObjCMethodDecl *getGetterMethodDecl() const { return GetterMethodDecl; }
+  void setGetterMethodDecl(ObjCMethodDecl *MD) { GetterMethodDecl = MD; }
+
+  ObjCMethodDecl *getSetterMethodDecl() const { return SetterMethodDecl; }
+  void setSetterMethodDecl(ObjCMethodDecl *MD) { SetterMethodDecl = MD; }
+
   Expr *getGetterCXXConstructor() const {
     return GetterCXXConstructor;
   }
diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index 9477e414cf554..46b978074f3df 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -3963,10 +3963,10 @@ ExpectedDecl ASTNodeImporter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
 
   ObjCMethodDecl *ToMethod;
   if (GetImportedOrCreateDecl(
-          ToMethod, D, Importer.getToContext(), Loc,
-          ToEndLoc, Name.getObjCSelector(), ToReturnType,
-          ToReturnTypeSourceInfo, DC, D->isInstanceMethod(), D->isVariadic(),
-          D->isPropertyAccessor(), D->isImplicit(), D->isDefined(),
+          ToMethod, D, Importer.getToContext(), Loc, ToEndLoc,
+          Name.getObjCSelector(), ToReturnType, ToReturnTypeSourceInfo, DC,
+          D->isInstanceMethod(), D->isVariadic(), D->isPropertyAccessor(),
+          D->isSynthesizedAccessorStub(), D->isImplicit(), D->isDefined(),
           D->getImplementationControl(), D->hasRelatedResultType()))
     return ToMethod;
 
diff --git a/clang/lib/AST/DeclObjC.cpp b/clang/lib/AST/DeclObjC.cpp
index bf748fbab8e96..26017e4193dd0 100644
--- a/clang/lib/AST/DeclObjC.cpp
+++ b/clang/lib/AST/DeclObjC.cpp
@@ -775,14 +775,12 @@ ObjCMethodDecl *ObjCInterfaceDecl::lookupPrivateMethod(
 // ObjCMethodDecl
 //===----------------------------------------------------------------------===//
 
-ObjCMethodDecl::ObjCMethodDecl(SourceLocation beginLoc, SourceLocation endLoc,
-                               Selector SelInfo, QualType T,
-                               TypeSourceInfo *ReturnTInfo,
-                               DeclContext *contextDecl, bool isInstance,
-                               bool isVariadic, bool isPropertyAccessor,
-                               bool isImplicitlyDeclared, bool isDefined,
-                               ImplementationControl impControl,
-                               bool HasRelatedResultType)
+ObjCMethodDecl::ObjCMethodDecl(
+    SourceLocation beginLoc, SourceLocation endLoc, Selector SelInfo,
+    QualType T, TypeSourceInfo *ReturnTInfo, DeclContext *contextDecl,
+    bool isInstance, bool isVariadic, bool isPropertyAccessor,
+    bool isSynthesizedAccessorStub, bool isImplicitlyDeclared, bool isDefined,
+    ImplementationControl impControl, bool HasRelatedResultType)
     : NamedDecl(ObjCMethod, contextDecl, beginLoc, SelInfo),
       DeclContext(ObjCMethod), MethodDeclType(T), ReturnTInfo(ReturnTInfo),
       DeclEndLoc(endLoc) {
@@ -793,6 +791,7 @@ ObjCMethodDecl::ObjCMethodDecl(SourceLocation beginLoc, SourceLocation endLoc,
   setInstanceMethod(isInstance);
   setVariadic(isVariadic);
   setPropertyAccessor(isPropertyAccessor);
+  setSynthesizedAccessorStub(isSynthesizedAccessorStub);
   setDefined(isDefined);
   setIsRedeclaration(false);
   setHasRedeclaration(false);
@@ -810,12 +809,13 @@ ObjCMethodDecl *ObjCMethodDecl::Create(
     ASTContext &C, SourceLocation beginLoc, SourceLocation endLoc,
     Selector SelInfo, QualType T, TypeSourceInfo *ReturnTInfo,
     DeclContext *contextDecl, bool isInstance, bool isVariadic,
-    bool isPropertyAccessor, bool isImplicitlyDeclared, bool isDefined,
-    ImplementationControl impControl, bool HasRelatedResultType) {
+    bool isPropertyAccessor, bool isSynthesizedAccessorStub,
+    bool isImplicitlyDeclared, bool isDefined, ImplementationControl impControl,
+    bool HasRelatedResultType) {
   return new (C, contextDecl) ObjCMethodDecl(
       beginLoc, endLoc, SelInfo, T, ReturnTInfo, contextDecl, isInstance,
-      isVariadic, isPropertyAccessor, isImplicitlyDeclared, isDefined,
-      impControl, HasRelatedResultType);
+      isVariadic, isPropertyAccessor, isSynthesizedAccessorStub,
+      isImplicitlyDeclared, isDefined, impControl, HasRelatedResultType);
 }
 
 ObjCMethodDecl *ObjCMethodDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
@@ -1306,6 +1306,11 @@ ObjCMethodDecl::findPropertyDecl(bool CheckOverrides) const {
 
   if (isPropertyAccessor()) {
     const auto *Container = cast<ObjCContainerDecl>(getParent());
+    // For accessor stubs, go back to the interface.
+    if (auto *ImplDecl = dyn_cast<ObjCImplDecl>(Container))
+      if (isSynthesizedAccessorStub())
+        Container = ImplDecl->getClassInterface();
+
     bool IsGetter = (NumArgs == 0);
     bool IsInstance = isInstanceMethod();
 
@@ -1358,6 +1363,15 @@ ObjCMethodDecl::findPropertyDecl(bool CheckOverrides) const {
       }
     }
 
+    assert(isSynthesizedAccessorStub() && "expected an accessor stub");
+    for (const auto *Cat : ClassDecl->known_categories()) {
+      if (Cat == Container)
+        continue;
+
+      if (const auto *Found = findMatchingProperty(Cat))
+        return Found;
+    }
+
     llvm_unreachable("Marked as a property accessor but no property found!");
   }
 
diff --git a/clang/lib/Analysis/BodyFarm.cpp b/clang/lib/Analysis/BodyFarm.cpp
index 43f9e715b3de2..be065ed9330fa 100644
--- a/clang/lib/Analysis/BodyFarm.cpp
+++ b/clang/lib/Analysis/BodyFarm.cpp
@@ -830,6 +830,16 @@ Stmt *BodyFarm::getBody(const ObjCMethodDecl *D) {
   if (D->param_size() != 0)
     return nullptr;
 
+  // If the property was defined in an extension, search the extensions for
+  // overrides.
+  const ObjCInterfaceDecl *OID = D->getClassInterface();
+  if (dyn_cast<ObjCInterfaceDecl>(D->getParent()) != OID)
+    for (auto *Ext : OID->known_extensions()) {
+      auto *OMD = Ext->getInstanceMethod(D->getSelector());
+      if (OMD && !OMD->isImplicit())
+        return nullptr;
+    }
+
   Val = createObjCPropertyGetter(C, Prop);
 
   return Val.getValue();
diff --git a/clang/lib/CodeGen/CGObjC.cpp b/clang/lib/CodeGen/CGObjC.cpp
index 1fa72678081af..c509149af3f95 100644
--- a/clang/lib/CodeGen/CGObjC.cpp
+++ b/clang/lib/CodeGen/CGObjC.cpp
@@ -954,8 +954,7 @@ void CodeGenFunction::GenerateObjCGetter(ObjCImplementationDecl *IMP,
                                          const ObjCPropertyImplDecl *PID) {
   llvm::Constant *AtomicHelperFn =
       CodeGenFunction(CGM).GenerateObjCAtomicGetterCopyHelperFunction(PID);
-  const ObjCPropertyDecl *PD = PID->getPropertyDecl();
-  ObjCMethodDecl *OMD = PD->getGetterMethodDecl();
+  ObjCMethodDecl *OMD = PID->getGetterMethodDecl();
   assert(OMD && "Invalid call to generate getter (empty method)");
   StartObjCMethod(OMD, IMP->getClassInterface());
 
@@ -1041,7 +1040,7 @@ CodeGenFunction::generateObjCGetterBody(const ObjCImplementationDecl *classImpl,
 
   const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
   QualType propType = prop->getType();
-  ObjCMethodDecl *getterMethod = prop->getGetterMethodDecl();
+  ObjCMethodDecl *getterMethod = propImpl->getGetterMethodDecl();
 
   ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
 
@@ -1311,9 +1310,8 @@ void
 CodeGenFunction::generateObjCSetterBody(const ObjCImplementationDecl *classImpl,
                                         const ObjCPropertyImplDecl *propImpl,
                                         llvm::Constant *AtomicHelperFn) {
-  const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
   ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
-  ObjCMethodDecl *setterMethod = prop->getSetterMethodDecl();
+  ObjCMethodDecl *setterMethod = propImpl->getSetterMethodDecl();
 
   // Just use the setter expression if Sema gave us one and it's
   // non-trivial.
@@ -1490,8 +1488,7 @@ void CodeGenFunction::GenerateObjCSetter(ObjCImplementationDecl *IMP,
                                          const ObjCPropertyImplDecl *PID) {
   llvm::Constant *AtomicHelperFn =
       CodeGenFunction(CGM).GenerateObjCAtomicSetterCopyHelperFunction(PID);
-  const ObjCPropertyDecl *PD = PID->getPropertyDecl();
-  ObjCMethodDecl *OMD = PD->getSetterMethodDecl();
+  ObjCMethodDecl *OMD = PID->getSetterMethodDecl();
   assert(OMD && "Invalid call to generate setter (empty method)");
   StartObjCMethod(OMD, IMP->getClassInterface());
 
diff --git a/clang/lib/CodeGen/CGObjCGNU.cpp b/clang/lib/CodeGen/CGObjCGNU.cpp
index d2c089d0360e1..c27023748588d 100644
--- a/clang/lib/CodeGen/CGObjCGNU.cpp
+++ b/clang/lib/CodeGen/CGObjCGNU.cpp
@@ -1880,13 +1880,12 @@ class CGObjCGNUstep2 : public CGObjCGNUstep {
     for (auto *propImpl : OID->property_impls())
       if (propImpl->getPropertyImplementation() ==
           ObjCPropertyImplDecl::Synthesize) {
-        ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
-        auto addIfExists = [&](const ObjCMethodDecl* OMD) {
-          if (OMD)
+        auto addIfExists = [&](const ObjCMethodDecl *OMD) {
+          if (OMD && OMD->hasBody())
             InstanceMethods.push_back(OMD);
         };
-        addIfExists(prop->getGetterMethodDecl());
-        addIfExists(prop->getSetterMethodDecl());
+        addIfExists(propImpl->getGetterMethodDecl());
+        addIfExists(propImpl->getSetterMethodDecl());
       }
 
     if (InstanceMethods.size() == 0)
@@ -3494,13 +3493,12 @@ void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
   for (auto *propertyImpl : OID->property_impls())
     if (propertyImpl->getPropertyImplementation() ==
         ObjCPropertyImplDecl::Synthesize) {
-      ObjCPropertyDecl *property = propertyImpl->getPropertyDecl();
       auto addPropertyMethod = [&](const ObjCMethodDecl *accessor) {
         if (accessor)
           InstanceMethods.push_back(accessor);
       };
-      addPropertyMethod(property->getGetterMethodDecl());
-      addPropertyMethod(property->getSetterMethodDecl());
+      addPropertyMethod(propertyImpl->getGetterMethodDecl());
+      addPropertyMethod(propertyImpl->getSetterMethodDecl());
     }
 
   llvm::Constant *Properties = GeneratePropertyList(OID, ClassDecl);
diff --git a/clang/lib/CodeGen/CGObjCMac.cpp b/clang/lib/CodeGen/CGObjCMac.cpp
index 8e28b2f05c167..d08a26f538bb0 100644
--- a/clang/lib/CodeGen/CGObjCMac.cpp
+++ b/clang/lib/CodeGen/CGObjCMac.cpp
@@ -3559,12 +3559,10 @@ void CGObjCMac::GenerateClass(const ObjCImplementationDecl *ID) {
 
   for (const auto *PID : ID->property_impls()) {
     if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
-      ObjCPropertyDecl *PD = PID->getPropertyDecl();
-
-      if (ObjCMethodDecl *MD = PD->getGetterMethodDecl())
+      if (ObjCMethodDecl *MD = PID->getGetterMethodDecl())
         if (GetMethodDefinition(MD))
           Methods[InstanceMethods].push_back(MD);
-      if (ObjCMethodDecl *MD = PD->getSetterMethodDecl())
+      if (ObjCMethodDecl *MD = PID->getSetterMethodDecl())
         if (GetMethodDefinition(MD))
           Methods[InstanceMethods].push_back(MD);
     }
@@ -6232,19 +6230,6 @@ llvm::GlobalVariable * CGObjCNonFragileABIMac::BuildClassRoTInitializer(
   } else {
     for (const auto *MD : ID->instance_methods())
       methods.push_back(MD);
-
-    for (const auto *PID : ID->property_impls()) {
-      if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize){
-        ObjCPropertyDecl *PD = PID->getPropertyDecl();
-
-        if (auto MD = PD->getGetterMethodDecl())
-          if (GetMethodDefinition(MD))
-            methods.push_back(MD);
-        if (auto MD = PD->getSetterMethodDecl())
-          if (GetMethodDefinition(MD))
-            methods.push_back(MD);
-      }
-    }
   }
 
   values.add(emitMethodList(ID->getObjCRuntimeNameAsString(),
@@ -6707,9 +6692,8 @@ CGObjCNonFragileABIMac::emitMethodList(Twine name, MethodListType kind,
   // method_count
   values.addInt(ObjCTypes.IntTy, methods.size());
   auto methodArray = values.beginArray(ObjCTypes.MethodTy);
-  for (auto MD : methods) {
+  for (auto MD : methods)
     emitMethodConstant(methodArray, MD, forProtocol);
-  }
   methodArray.finishAndAddTo(values);
 
   llvm::GlobalVariable *GV = finishAndCreateGlobal(values, prefix + name, CGM);
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index b7f70b8aa5c00..3cb73f6d97ce7 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -690,8 +690,7 @@ static llvm::Constant *getPrologueSignature(CodeGenModule &CGM,
   return CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM);
 }
 
-void CodeGenFunction::StartFunction(GlobalDecl GD,
-                                    QualType RetTy,
+void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
                                     llvm::Function *Fn,
                                     const CGFunctionInfo &FnInfo,
                                     const FunctionArgList &Args,
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index be8f389e1809c..a8cec419059e2 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -5113,11 +5113,12 @@ void CodeGenModule::EmitObjCPropertyImplementations(const
       // we want, that just indicates if the decl came from a
       // property. What we want to know is if the method is defined in
       // this implementation.
-      if (!D->getInstanceMethod(PD->getGetterName()))
+      auto *Getter = PID->getGetterMethodDecl();
+      if (!Getter || Getter->isSynthesizedAccessorStub())
         CodeGenFunction(*this).GenerateObjCGetter(
-                                 const_cast<ObjCImplementationDecl *>(D), PID);
-      if (!PD->isReadOnly() &&
-          !D->getInstanceMethod(PD->getSetterName()))
+            const_cast<ObjCImplementationDecl *>(D), PID);
+      auto *Setter = PID->getSetterMethodDecl();
+      if (!PD->isReadOnly() && (!Setter || Setter->isSynthesizedAccessorStub()))
         CodeGenFunction(*this).GenerateObjCSetter(
                                  const_cast<ObjCImplementationDecl *>(D), PID);
     }
@@ -5154,12 +5155,13 @@ void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
   if (needsDestructMethod(D)) {
     IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
     Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
-    ObjCMethodDecl *DTORMethod =
-      ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(),
-                             cxxSelector, getContext().VoidTy, nullptr, D,
-                             /*isInstance=*/true, /*isVariadic=*/false,
-                          /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true,
-                             /*isDefined=*/false, ObjCMethodDecl::Required);
+    ObjCMethodDecl *DTORMethod = ObjCMethodDecl::Create(
+        getContext(), D->getLocation(), D->getLocation(), cxxSelector,
+        getContext().VoidTy, nullptr, D,
+        /*isInstance=*/true, /*isVariadic=*/false,
+        /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
+        /*isImplicitlyDeclared=*/true,
+        /*isDefined=*/false, ObjCMethodDecl::Required);
     D->addInstanceMethod(DTORMethod);
     CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
     D->setHasDestructors(true);
@@ -5174,17 +5176,13 @@ void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
   IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
   Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
   // The constructor returns 'self'.
-  ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(),
-                                                D->getLocation(),
-                                                D->getLocation(),
-                                                cxxSelector,
-                                                getContext().getObjCIdType(),
-                                                nullptr, D, /*isInstance=*/true,
-                                                /*isVariadic=*/false,
-                                                /*isPropertyAccessor=*/true,
-                                                /*isImplicitlyDeclared=*/true,
-                                                /*isDefined=*/false,
-                                                ObjCMethodDecl::Required);
+  ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(
+      getContext(), D->getLocation(), D->getLocation(), cxxSelector,
+      getContext().getObjCIdType(), nullptr, D, /*isInstance=*/true,
+      /*isVariadic=*/false,
+      /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
+      /*isImplicitlyDeclared=*/true,
+      /*isDefined=*/false, ObjCMethodDecl::Required);
   D->addInstanceMethod(CTORMethod);
   CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
   D->setHasNonZeroConstructors(true);
diff --git a/clang/lib/Frontend/Rewrite/RewriteModernObjC.cpp b/clang/lib/Frontend/Rewrite/RewriteModernObjC.cpp
index 45495065ada64..831f95e8c6be4 100644
--- a/clang/lib/Frontend/Rewrite/RewriteModernObjC.cpp
+++ b/clang/lib/Frontend/Rewrite/RewriteModernObjC.cpp
@@ -908,9 +908,9 @@ RewriteModernObjC::getIvarAccessString(ObjCIvarDecl *D) {
 static bool mustSynthesizeSetterGetterMethod(ObjCImplementationDecl *IMP,
                                              ObjCPropertyDecl *PD,
                                              bool getter) {
-  return getter ? !IMP->getInstanceMethod(PD->getGetterName())
-                : !IMP->getInstanceMethod(PD->getSetterName());
-
+  auto *OMD = IMP->getInstanceMethod(getter ? PD->getGetterName()
+                                            : PD->getSetterName());
+  return !OMD || OMD->isSynthesizedAccessorStub();
 }
 
 void RewriteModernObjC::RewritePropertyImplDecl(ObjCPropertyImplDecl *PID,
@@ -952,7 +952,7 @@ void RewriteModernObjC::RewritePropertyImplDecl(ObjCPropertyImplDecl *PID,
             "id objc_getProperty(id, SEL, long, bool);\n";
     }
     RewriteObjCMethodDecl(OID->getContainingInterface(),
-                          PD->getGetterMethodDecl(), Getr);
+                          PID->getGetterMethodDecl(), Getr);
     Getr += "{ ";
     // Synthesize an explicit cast to gain access to the ivar.
     // See objc-act.c:objc_synthesize_new_getter() for details.
@@ -960,7 +960,7 @@ void RewriteModernObjC::RewritePropertyImplDecl(ObjCPropertyImplDecl *PID,
       // return objc_getProperty(self, _cmd, offsetof(ClassDecl, OID), 1)
       Getr += "typedef ";
       const FunctionType *FPRetType = nullptr;
-      RewriteTypeIntoString(PD->getGetterMethodDecl()->getReturnType(), Getr,
+      RewriteTypeIntoString(PID->getGetterMethodDecl()->getReturnType(), Getr,
                             FPRetType);
       Getr += " _TYPE";
       if (FPRetType) {
@@ -1012,7 +1012,7 @@ void RewriteModernObjC::RewritePropertyImplDecl(ObjCPropertyImplDecl *PID,
   }
 
   RewriteObjCMethodDecl(OID->getContainingInterface(),
-                        PD->getSetterMethodDecl(), Setr);
+                        PID->getSetterMethodDecl(), Setr);
   Setr += "{ ";
   // Synthesize an explicit cast to initialize the ivar.
   // See objc-act.c:objc_synthesize_new_setter() for details.
@@ -1346,6 +1346,8 @@ void RewriteModernObjC::RewriteImplementationDecl(Decl *OID) {
     InsertText(CID->getBeginLoc(), "// ");
 
   for (auto *OMD : IMD ? IMD->instance_methods() : CID->instance_methods()) {
+    if (!OMD->getBody())
+      continue;
     std::string ResultStr;
     RewriteObjCMethodDecl(OMD->getClassInterface(), OMD, ResultStr);
     SourceLocation LocStart = OMD->getBeginLoc();
@@ -1357,6 +1359,8 @@ void RewriteModernObjC::RewriteImplementationDecl(Decl *OID) {
   }
 
   for (auto *OMD : IMD ? IMD->class_methods() : CID->class_methods()) {
+    if (!OMD->getBody())
+      continue;
     std::string ResultStr;
     RewriteObjCMethodDecl(OMD->getClassInterface(), OMD, ResultStr);
     SourceLocation LocStart = OMD->getBeginLoc();
@@ -7031,12 +7035,12 @@ void RewriteModernObjC::RewriteObjCClassMetaData(ObjCImplementationDecl *IDecl,
     ObjCPropertyDecl *PD = Prop->getPropertyDecl();
     if (!PD)
       continue;
-    if (ObjCMethodDecl *Getter = PD->getGetterMethodDecl())
+    if (ObjCMethodDecl *Getter = Prop->getGetterMethodDecl())
       if (mustSynthesizeSetterGetterMethod(IDecl, PD, true /*getter*/))
         InstanceMethods.push_back(Getter);
     if (PD->isReadOnly())
       continue;
-    if (ObjCMethodDecl *Setter = PD->getSetterMethodDecl())
+    if (ObjCMethodDecl *Setter = Prop->getSetterMethodDecl())
       if (mustSynthesizeSetterGetterMethod(IDecl, PD, false /*setter*/))
         InstanceMethods.push_back(Setter);
   }
@@ -7281,11 +7285,11 @@ void RewriteModernObjC::RewriteObjCCategoryImplDecl(ObjCCategoryImplDecl *IDecl,
     ObjCPropertyDecl *PD = Prop->getPropertyDecl();
     if (!PD)
       continue;
-    if (ObjCMethodDecl *Getter = PD->getGetterMethodDecl())
+    if (ObjCMethodDecl *Getter = Prop->getGetterMethodDecl())
       InstanceMethods.push_back(Getter);
     if (PD->isReadOnly())
       continue;
-    if (ObjCMethodDecl *Setter = PD->getSetterMethodDecl())
+    if (ObjCMethodDecl *Setter = Prop->getSetterMethodDecl())
       InstanceMethods.push_back(Setter);
   }
 
diff --git a/clang/lib/Frontend/Rewrite/RewriteObjC.cpp b/clang/lib/Frontend/Rewrite/RewriteObjC.cpp
index 6a22da178fbc9..0cb7592b99820 100644
--- a/clang/lib/Frontend/Rewrite/RewriteObjC.cpp
+++ b/clang/lib/Frontend/Rewrite/RewriteObjC.cpp
@@ -786,8 +786,9 @@ void RewriteObjC::RewritePropertyImplDecl(ObjCPropertyImplDecl *PID,
 
   if (!OID)
     return;
+
   unsigned Attributes = PD->getPropertyAttributes();
-  if (!PD->getGetterMethodDecl()->isDefined()) {
+  if (PID->getGetterMethodDecl() && !PID->getGetterMethodDecl()->isDefined()) {
     bool GenGetProperty = !(Attributes & ObjCPropertyDecl::OBJC_PR_nonatomic) &&
                           (Attributes & (ObjCPropertyDecl::OBJC_PR_retain |
                                          ObjCPropertyDecl::OBJC_PR_copy));
@@ -799,7 +800,7 @@ void RewriteObjC::RewritePropertyImplDecl(ObjCPropertyImplDecl *PID,
             "id objc_getProperty(id, SEL, long, bool);\n";
     }
     RewriteObjCMethodDecl(OID->getContainingInterface(),
-                          PD->getGetterMethodDecl(), Getr);
+                          PID->getGetterMethodDecl(), Getr);
     Getr += "{ ";
     // Synthesize an explicit cast to gain access to the ivar.
     // See objc-act.c:objc_synthesize_new_getter() for details.
@@ -807,7 +808,7 @@ void RewriteObjC::RewritePropertyImplDecl(ObjCPropertyImplDecl *PID,
       // return objc_getProperty(self, _cmd, offsetof(ClassDecl, OID), 1)
       Getr += "typedef ";
       const FunctionType *FPRetType = nullptr;
-      RewriteTypeIntoString(PD->getGetterMethodDecl()->getReturnType(), Getr,
+      RewriteTypeIntoString(PID->getGetterMethodDecl()->getReturnType(), Getr,
                             FPRetType);
       Getr += " _TYPE";
       if (FPRetType) {
@@ -843,7 +844,8 @@ void RewriteObjC::RewritePropertyImplDecl(ObjCPropertyImplDecl *PID,
     InsertText(onePastSemiLoc, Getr);
   }
 
-  if (PD->isReadOnly() || PD->getSetterMethodDecl()->isDefined())
+  if (PD->isReadOnly() || !PID->getSetterMethodDecl() ||
+      PID->getSetterMethodDecl()->isDefined())
     return;
 
   // Generate the 'setter' function.
@@ -858,7 +860,7 @@ void RewriteObjC::RewritePropertyImplDecl(ObjCPropertyImplDecl *PID,
   }
 
   RewriteObjCMethodDecl(OID->getContainingInterface(),
-                        PD->getSetterMethodDecl(), Setr);
+                        PID->getSetterMethodDecl(), Setr);
   Setr += "{ ";
   // Synthesize an explicit cast to initialize the ivar.
   // See objc-act.c:objc_synthesize_new_setter() for details.
@@ -1168,6 +1170,8 @@ void RewriteObjC::RewriteImplementationDecl(Decl *OID) {
   InsertText(IMD ? IMD->getBeginLoc() : CID->getBeginLoc(), "// ");
 
   for (auto *OMD : IMD ? IMD->instance_methods() : CID->instance_methods()) {
+    if (!OMD->getBody())
+      continue;
     std::string ResultStr;
     RewriteObjCMethodDecl(OMD->getClassInterface(), OMD, ResultStr);
     SourceLocation LocStart = OMD->getBeginLoc();
@@ -1179,6 +1183,8 @@ void RewriteObjC::RewriteImplementationDecl(Decl *OID) {
   }
 
   for (auto *OMD : IMD ? IMD->class_methods() : CID->class_methods()) {
+    if (!OMD->getBody())
+      continue;
     std::string ResultStr;
     RewriteObjCMethodDecl(OMD->getClassInterface(), OMD, ResultStr);
     SourceLocation LocStart = OMD->getBeginLoc();
@@ -5355,12 +5361,12 @@ void RewriteObjCFragileABI::RewriteObjCClassMetaData(ObjCImplementationDecl *IDe
     ObjCPropertyDecl *PD = Prop->getPropertyDecl();
     if (!PD)
       continue;
-    if (ObjCMethodDecl *Getter = PD->getGetterMethodDecl())
+    if (ObjCMethodDecl *Getter = Prop->getGetterMethodDecl())
       if (!Getter->isDefined())
         InstanceMethods.push_back(Getter);
     if (PD->isReadOnly())
       continue;
-    if (ObjCMethodDecl *Setter = PD->getSetterMethodDecl())
+    if (ObjCMethodDecl *Setter = Prop->getSetterMethodDecl())
       if (!Setter->isDefined())
         InstanceMethods.push_back(Setter);
   }
@@ -5633,11 +5639,11 @@ void RewriteObjCFragileABI::RewriteObjCCategoryImplDecl(ObjCCategoryImplDecl *ID
     ObjCPropertyDecl *PD = Prop->getPropertyDecl();
     if (!PD)
       continue;
-    if (ObjCMethodDecl *Getter = PD->getGetterMethodDecl())
+    if (ObjCMethodDecl *Getter = Prop->getGetterMethodDecl())
       InstanceMethods.push_back(Getter);
     if (PD->isReadOnly())
       continue;
-    if (ObjCMethodDecl *Setter = PD->getSetterMethodDecl())
+    if (ObjCMethodDecl *Setter = Prop->getSetterMethodDecl())
       InstanceMethods.push_back(Setter);
   }
   RewriteObjCMethodsMetaData(InstanceMethods.begin(), InstanceMethods.end(),
diff --git a/clang/lib/Index/IndexDecl.cpp b/clang/lib/Index/IndexDecl.cpp
index 5bbbb0d32bf45..985098fc61654 100644
--- a/clang/lib/Index/IndexDecl.cpp
+++ b/clang/lib/Index/IndexDecl.cpp
@@ -42,15 +42,6 @@ class IndexingDeclVisitor : public ConstDeclVisitor<IndexingDeclVisitor, bool> {
     return true;
   }
 
-  /// Returns true if the given method has been defined explicitly by the
-  /// user.
-  static bool hasUserDefined(const ObjCMethodDecl *D,
-                             const ObjCImplDecl *Container) {
-    const ObjCMethodDecl *MD = Container->getMethod(D->getSelector(),
-                                                    D->isInstanceMethod());
-    return MD && !MD->isImplicit() && MD->isThisDeclarationADefinition();
-  }
-
   void handleTemplateArgumentLoc(const TemplateArgumentLoc &TALoc,
                                  const NamedDecl *Parent,
                                  const DeclContext *DC) {
@@ -78,6 +69,17 @@ class IndexingDeclVisitor : public ConstDeclVisitor<IndexingDeclVisitor, bool> {
     }
   }
 
+  /// Returns true if the given method has been defined explicitly by the
+  /// user.
+  static bool hasUserDefined(const ObjCMethodDecl *D,
+                             const ObjCImplDecl *Container) {
+    const ObjCMethodDecl *MD = Container->getMethod(D->getSelector(),
+                                                    D->isInstanceMethod());
+    return MD && !MD->isImplicit() && MD->isThisDeclarationADefinition() &&
+           !MD->isSynthesizedAccessorStub();
+  }
+
+  
   void handleDeclarator(const DeclaratorDecl *D,
                         const NamedDecl *Parent = nullptr,
                         bool isIBType = false) {
@@ -534,13 +536,11 @@ class IndexingDeclVisitor : public ConstDeclVisitor<IndexingDeclVisitor, bool> {
     SymbolRoleSet AccessorMethodRoles =
       SymbolRoleSet(SymbolRole::Dynamic) | SymbolRoleSet(SymbolRole::Implicit);
     if (ObjCMethodDecl *MD = PD->getGetterMethodDecl()) {
-      if (MD->isPropertyAccessor() &&
-          !hasUserDefined(MD, Container))
+      if (MD->isPropertyAccessor() && !hasUserDefined(MD, Container))
         IndexCtx.handleDecl(MD, Loc, AccessorMethodRoles, {}, Container);
     }
     if (ObjCMethodDecl *MD = PD->getSetterMethodDecl()) {
-      if (MD->isPropertyAccessor() &&
-          !hasUserDefined(MD, Container))
+      if (MD->isPropertyAccessor() && !hasUserDefined(MD, Container))
         IndexCtx.handleDecl(MD, Loc, AccessorMethodRoles, {}, Container);
     }
     if (ObjCIvarDecl *IvarD = D->getPropertyIvarDecl()) {
diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
index db594bbd21ddc..30a1b95d42409 100644
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -2828,6 +2828,9 @@ void Sema::MatchAllMethodDeclarations(const SelectorSet &InsMap,
              "Expected to find the method through lookup as well");
       // ImpMethodDecl may be null as in a @dynamic property.
       if (ImpMethodDecl) {
+        // Skip property accessor function stubs.
+        if (ImpMethodDecl->isSynthesizedAccessorStub())
+          continue;
         if (!WarnCategoryMethodImpl)
           WarnConflictingTypedMethods(ImpMethodDecl, I,
                                       isa<ObjCProtocolDecl>(CDecl));
@@ -2854,6 +2857,9 @@ void Sema::MatchAllMethodDeclarations(const SelectorSet &InsMap,
              "Expected to find the method through lookup as well");
       // ImpMethodDecl may be null as in a @dynamic property.
       if (ImpMethodDecl) {
+        // Skip property accessor function stubs.
+        if (ImpMethodDecl->isSynthesizedAccessorStub())
+          continue;
         if (!WarnCategoryMethodImpl)
           WarnConflictingTypedMethods(ImpMethodDecl, I,
                                       isa<ObjCProtocolDecl>(CDecl));
@@ -3903,6 +3909,25 @@ Decl *Sema::ActOnAtEnd(Scope *S, SourceRange AtEnd, ArrayRef<Decl *> allMethods,
          || isa<ObjCProtocolDecl>(ClassDecl);
   bool checkIdenticalMethods = isa<ObjCImplementationDecl>(ClassDecl);
 
+  // Make synthesized accessor stub functions visible.
+  // ActOnPropertyImplDecl() creates them as not visible in case
+  // they are overridden by an explicit method that is encountered
+  // later.
+  if (auto *OID = dyn_cast<ObjCImplementationDecl>(CurContext)) {
+    for (auto PropImpl : OID->property_impls()) {
+      if (auto *Getter = PropImpl->getGetterMethodDecl())
+        if (Getter->isSynthesizedAccessorStub()) {
+          OID->makeDeclVisibleInContext(Getter);
+          OID->addDecl(Getter);
+        }
+      if (auto *Setter = PropImpl->getSetterMethodDecl())
+        if (Setter->isSynthesizedAccessorStub()) {
+          OID->makeDeclVisibleInContext(Setter);
+          OID->addDecl(Setter);
+        }
+    }
+  }
+
   // FIXME: Remove these and use the ObjCContainerDecl/DeclContext.
   llvm::DenseMap<Selector, const ObjCMethodDecl*> InsMap;
   llvm::DenseMap<Selector, const ObjCMethodDecl*> ClsMap;
@@ -4001,8 +4026,8 @@ Decl *Sema::ActOnAtEnd(Scope *S, SourceRange AtEnd, ArrayRef<Decl *> allMethods,
               continue;
 
           for (const auto *Ext : IDecl->visible_extensions()) {
-            if (ObjCMethodDecl *GetterMethod
-                  = Ext->getInstanceMethod(Property->getGetterName()))
+            if (ObjCMethodDecl *GetterMethod =
+                    Ext->getInstanceMethod(Property->getGetterName()))
               GetterMethod->setPropertyAccessor(true);
             if (!Property->isReadOnly())
               if (ObjCMethodDecl *SetterMethod
@@ -4551,6 +4576,7 @@ Decl *Sema::ActOnMethodDeclaration(
     Diag(MethodLoc, diag::err_missing_method_context);
     return nullptr;
   }
+
   Decl *ClassDecl = cast<ObjCContainerDecl>(CurContext);
   QualType resultDeclType;
 
@@ -4574,7 +4600,7 @@ Decl *Sema::ActOnMethodDeclaration(
   ObjCMethodDecl *ObjCMethod = ObjCMethodDecl::Create(
       Context, MethodLoc, EndLoc, Sel, resultDeclType, ReturnTInfo, CurContext,
       MethodType == tok::minus, isVariadic,
-      /*isPropertyAccessor=*/false,
+      /*isPropertyAccessor=*/false, /*isSynthesizedAccessorStub=*/false,
       /*isImplicitlyDeclared=*/false, /*isDefined=*/false,
       MethodDeclKind == tok::objc_optional ? ObjCMethodDecl::Optional
                                            : ObjCMethodDecl::Required,
@@ -4666,6 +4692,27 @@ Decl *Sema::ActOnMethodDeclaration(
       ImpDecl->addClassMethod(ObjCMethod);
     }
 
+    // If this method overrides a previous @synthesize declaration,
+    // register it with the property.  Linear search through all
+    // properties here, because the autosynthesized stub hasn't been
+    // made visible yet, so it can be overriden by a later
+    // user-specified implementation.
+    for (ObjCPropertyImplDecl *PropertyImpl : ImpDecl->property_impls()) {
+      if (auto *Setter = PropertyImpl->getSetterMethodDecl())
+        if (Setter->getSelector() == Sel &&
+            Setter->isInstanceMethod() == ObjCMethod->isInstanceMethod()) {
+          assert(Setter->isSynthesizedAccessorStub() && "autosynth stub expected");
+          PropertyImpl->setSetterMethodDecl(ObjCMethod);
+        }
+      if (auto *Getter = PropertyImpl->getGetterMethodDecl())
+        if (Getter->getSelector() == Sel &&
+            Getter->isInstanceMethod() == ObjCMethod->isInstanceMethod()) {
+          assert(Getter->isSynthesizedAccessorStub() && "autosynth stub expected");
+          PropertyImpl->setGetterMethodDecl(ObjCMethod);
+          break;
+        }
+    }
+
     // Merge information from the @interface declaration into the
     // @implementation.
     if (ObjCInterfaceDecl *IDecl = ImpDecl->getClassInterface()) {
@@ -5063,6 +5110,9 @@ void Sema::DiagnoseUnusedBackingIvarInAccessor(Scope *S,
     if (!IV)
       continue;
 
+    if (CurMethod->isSynthesizedAccessorStub())
+      continue;
+
     UnusedBackingIvarChecker Checker(*this, CurMethod, IV);
     Checker.TraverseStmt(CurMethod->getBody());
     if (Checker.AccessedIvar)
diff --git a/clang/lib/Sema/SemaExprObjC.cpp b/clang/lib/Sema/SemaExprObjC.cpp
index e18621e42a6b1..207812c8848b7 100644
--- a/clang/lib/Sema/SemaExprObjC.cpp
+++ b/clang/lib/Sema/SemaExprObjC.cpp
@@ -288,6 +288,7 @@ static ObjCMethodDecl *getNSNumberFactoryMethod(Sema &S, SourceLocation Loc,
                                S.NSNumberPointer, ReturnTInfo, S.NSNumberDecl,
                                /*isInstance=*/false, /*isVariadic=*/false,
                                /*isPropertyAccessor=*/false,
+                               /*isSynthesizedAccessorStub=*/false,
                                /*isImplicitlyDeclared=*/true,
                                /*isDefined=*/false, ObjCMethodDecl::Required,
                                /*HasRelatedResultType=*/false);
@@ -563,6 +564,7 @@ ExprResult Sema::BuildObjCBoxedExpr(SourceRange SR, Expr *ValueExpr) {
               NSStringPointer, ReturnTInfo, NSStringDecl,
               /*isInstance=*/false, /*isVariadic=*/false,
               /*isPropertyAccessor=*/false,
+              /*isSynthesizedAccessorStub=*/false,
               /*isImplicitlyDeclared=*/true,
               /*isDefined=*/false, ObjCMethodDecl::Required,
               /*HasRelatedResultType=*/false);
@@ -671,20 +673,15 @@ ExprResult Sema::BuildObjCBoxedExpr(SourceRange SR, Expr *ValueExpr) {
         // Debugger needs to work even if NSValue hasn't been defined.
         TypeSourceInfo *ReturnTInfo = nullptr;
         ObjCMethodDecl *M = ObjCMethodDecl::Create(
-                                               Context,
-                                               SourceLocation(),
-                                               SourceLocation(),
-                                               ValueWithBytesObjCType,
-                                               NSValuePointer,
-                                               ReturnTInfo,
-                                               NSValueDecl,
-                                               /*isInstance=*/false,
-                                               /*isVariadic=*/false,
-                                               /*isPropertyAccessor=*/false,
-                                               /*isImplicitlyDeclared=*/true,
-                                               /*isDefined=*/false,
-                                               ObjCMethodDecl::Required,
-                                               /*HasRelatedResultType=*/false);
+            Context, SourceLocation(), SourceLocation(), ValueWithBytesObjCType,
+            NSValuePointer, ReturnTInfo, NSValueDecl,
+            /*isInstance=*/false,
+            /*isVariadic=*/false,
+            /*isPropertyAccessor=*/false,
+            /*isSynthesizedAccessorStub=*/false,
+            /*isImplicitlyDeclared=*/true,
+            /*isDefined=*/false, ObjCMethodDecl::Required,
+            /*HasRelatedResultType=*/false);
 
         SmallVector<ParmVarDecl *, 2> Params;
 
@@ -815,7 +812,7 @@ ExprResult Sema::BuildObjCArrayLiteral(SourceRange SR, MultiExprArg Elements) {
           Context, SourceLocation(), SourceLocation(), Sel, IdT, ReturnTInfo,
           Context.getTranslationUnitDecl(), false /*Instance*/,
           false /*isVariadic*/,
-          /*isPropertyAccessor=*/false,
+          /*isPropertyAccessor=*/false, /*isSynthesizedAccessorStub=*/false,
           /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
           ObjCMethodDecl::Required, false);
       SmallVector<ParmVarDecl *, 2> Params;
@@ -916,16 +913,14 @@ ExprResult Sema::BuildObjCDictionaryLiteral(SourceRange SR,
                                NSAPI::NSDict_dictionaryWithObjectsForKeysCount);
     ObjCMethodDecl *Method = NSDictionaryDecl->lookupClassMethod(Sel);
     if (!Method && getLangOpts().DebuggerObjCLiteral) {
-      Method = ObjCMethodDecl::Create(Context,
-                           SourceLocation(), SourceLocation(), Sel,
-                           IdT,
-                           nullptr /*TypeSourceInfo */,
-                           Context.getTranslationUnitDecl(),
-                           false /*Instance*/, false/*isVariadic*/,
-                           /*isPropertyAccessor=*/false,
-                           /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
-                           ObjCMethodDecl::Required,
-                           false);
+      Method = ObjCMethodDecl::Create(
+          Context, SourceLocation(), SourceLocation(), Sel, IdT,
+          nullptr /*TypeSourceInfo */, Context.getTranslationUnitDecl(),
+          false /*Instance*/, false /*isVariadic*/,
+          /*isPropertyAccessor=*/false,
+          /*isSynthesizedAccessorStub=*/false,
+          /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
+          ObjCMethodDecl::Required, false);
       SmallVector<ParmVarDecl *, 3> Params;
       ParmVarDecl *objects = ParmVarDecl::Create(Context, Method,
                                                  SourceLocation(),
diff --git a/clang/lib/Sema/SemaObjCProperty.cpp b/clang/lib/Sema/SemaObjCProperty.cpp
index ac810745d2f5f..427def1b94ea1 100644
--- a/clang/lib/Sema/SemaObjCProperty.cpp
+++ b/clang/lib/Sema/SemaObjCProperty.cpp
@@ -1037,6 +1037,31 @@ static bool hasWrittenStorageAttribute(ObjCPropertyDecl *Prop,
   return false;
 }
 
+/// Create a synthesized property accessor stub inside the \@implementation.
+static ObjCMethodDecl *
+RedeclarePropertyAccessor(ASTContext &Context, ObjCImplementationDecl *Impl,
+                          ObjCMethodDecl *AccessorDecl, SourceLocation AtLoc,
+                          SourceLocation PropertyLoc) {
+  ObjCMethodDecl *Decl = AccessorDecl;
+  ObjCMethodDecl *ImplDecl = ObjCMethodDecl::Create(
+      Context, AtLoc, PropertyLoc, Decl->getSelector(), Decl->getReturnType(),
+      Decl->getReturnTypeSourceInfo(), Impl, Decl->isInstanceMethod(),
+      Decl->isVariadic(), Decl->isPropertyAccessor(), /* isSynthesized*/ true,
+      Decl->isImplicit(), Decl->isDefined(), Decl->getImplementationControl(),
+      Decl->hasRelatedResultType());
+  ImplDecl->getMethodFamily();
+  if (Decl->hasAttrs())
+    ImplDecl->setAttrs(Decl->getAttrs());
+  ImplDecl->setSelfDecl(Decl->getSelfDecl());
+  ImplDecl->setCmdDecl(Decl->getCmdDecl());
+  SmallVector<SourceLocation, 1> SelLocs;
+  Decl->getSelectorLocs(SelLocs);
+  ImplDecl->setMethodParams(Context, Decl->parameters(), SelLocs);
+  ImplDecl->setLexicalDeclContext(Impl);
+  ImplDecl->setDefined(false);
+  return ImplDecl;
+}
+
 /// ActOnPropertyImplDecl - This routine performs semantic checks and
 /// builds the AST node for a property implementation declaration; declared
 /// as \@synthesize or \@dynamic.
@@ -1404,6 +1429,18 @@ Decl *Sema::ActOnPropertyImplDecl(Scope *S,
 
   if (ObjCMethodDecl *getterMethod = property->getGetterMethodDecl()) {
     getterMethod->createImplicitParams(Context, IDecl);
+
+    // Redeclare the getter within the implementation as DeclContext.
+    if (Synthesize) {
+      // If the method hasn't been overridden, create a synthesized implementation.
+      ObjCMethodDecl *OMD = ClassImpDecl->getMethod(
+          getterMethod->getSelector(), getterMethod->isInstanceMethod());
+      if (!OMD)
+        OMD = RedeclarePropertyAccessor(Context, IC, getterMethod, AtLoc,
+                                        PropertyLoc);
+      PIDecl->setGetterMethodDecl(OMD);
+    }
+ 
     if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
         Ivar->getType()->isRecordType()) {
       // For Objective-C++, need to synthesize the AST for the IVAR object to be
@@ -1456,8 +1493,20 @@ Decl *Sema::ActOnPropertyImplDecl(Scope *S,
           break;
       }
   }
+
   if (ObjCMethodDecl *setterMethod = property->getSetterMethodDecl()) {
     setterMethod->createImplicitParams(Context, IDecl);
+
+    // Redeclare the setter within the implementation as DeclContext.
+    if (Synthesize) {
+      ObjCMethodDecl *OMD = ClassImpDecl->getMethod(
+          setterMethod->getSelector(), setterMethod->isInstanceMethod());
+      if (!OMD)
+        OMD = RedeclarePropertyAccessor(Context, IC, setterMethod,
+                                        AtLoc, PropertyLoc);
+      PIDecl->setSetterMethodDecl(OMD);
+    }
+
     if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
         Ivar->getType()->isRecordType()) {
       // FIXME. Eventually we want to do this for Objective-C as well.
@@ -1852,10 +1901,12 @@ void Sema::DefaultSynthesizeProperties(Scope *S, ObjCImplDecl *IMPDecl,
     if (IMPDecl->FindPropertyImplDecl(
             Prop->getIdentifier(), Prop->getQueryKind()))
       continue;
-    if (IMPDecl->getInstanceMethod(Prop->getGetterName())) {
+    ObjCMethodDecl *ImpMethod = IMPDecl->getInstanceMethod(Prop->getGetterName());
+    if (ImpMethod && !ImpMethod->getBody()) {
       if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
         continue;
-      if (IMPDecl->getInstanceMethod(Prop->getSetterName()))
+      ImpMethod = IMPDecl->getInstanceMethod(Prop->getSetterName());
+      if (ImpMethod && !ImpMethod->getBody())
         continue;
     }
     if (ObjCPropertyImplDecl *PID =
@@ -2083,7 +2134,6 @@ void Sema::DiagnoseUnimplementedProperties(Scope *S, ObjCImplDecl* IMPDecl,
 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()
@@ -2092,16 +2142,16 @@ void Sema::diagnoseNullResettableSynthesizedSetters(const ObjCImplDecl *impDecl)
          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())) {
+      auto *getterImpl = propertyImpl->getGetterMethodDecl();
+      auto *setterImpl = propertyImpl->getSetterMethodDecl();
+      if ((!getterImpl || getterImpl->isSynthesizedAccessorStub()) &&
+          (!setterImpl || setterImpl->isSynthesizedAccessorStub())) {
         SourceLocation loc = propertyImpl->getLocation();
         if (loc.isInvalid())
           loc = impDecl->getBeginLoc();
 
         Diag(loc, diag::warn_null_resettable_setter)
-          << setterMethod->getSelector() << property->getDeclName();
+          << setterImpl->getSelector() << property->getDeclName();
       }
     }
   }
@@ -2138,6 +2188,10 @@ Sema::AtomicPropertySetterGetterRules (ObjCImplDecl* IMPDecl,
       SetterMethod = Property->isClassProperty() ?
                      IMPDecl->getClassMethod(Property->getSetterName()) :
                      IMPDecl->getInstanceMethod(Property->getSetterName());
+      if (GetterMethod && GetterMethod->isSynthesizedAccessorStub())
+        GetterMethod = nullptr;
+      if (SetterMethod && SetterMethod->isSynthesizedAccessorStub())
+        SetterMethod = nullptr;
       LookedUpGetterSetter = true;
       if (GetterMethod) {
         Diag(GetterMethod->getLocation(),
@@ -2161,15 +2215,13 @@ Sema::AtomicPropertySetterGetterRules (ObjCImplDecl* IMPDecl,
             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)) {
+      GetterMethod = PIDecl->getGetterMethodDecl();
+      SetterMethod = PIDecl->getSetterMethodDecl();
+      if (GetterMethod && GetterMethod->isSynthesizedAccessorStub())
+        GetterMethod = nullptr;
+      if (SetterMethod && SetterMethod->isSynthesizedAccessorStub())
+        SetterMethod = nullptr;
+      if ((bool)GetterMethod ^ (bool)SetterMethod) {
         SourceLocation MethodLoc =
           (GetterMethod ? GetterMethod->getLocation()
                         : SetterMethod->getLocation());
@@ -2210,8 +2262,10 @@ void Sema::DiagnoseOwningPropertyGetterSynthesis(const ObjCImplementationDecl *D
   for (const auto *PID : D->property_impls()) {
     const ObjCPropertyDecl *PD = PID->getPropertyDecl();
     if (PD && !PD->hasAttr<NSReturnsNotRetainedAttr>() &&
-        !PD->isClassProperty() &&
-        !D->getInstanceMethod(PD->getGetterName())) {
+        !PD->isClassProperty()) {
+      ObjCMethodDecl *IM = PID->getGetterMethodDecl();
+      if (IM && !IM->isSynthesizedAccessorStub())
+        continue;
       ObjCMethodDecl *method = PD->getGetterMethodDecl();
       if (!method)
         continue;
@@ -2396,16 +2450,14 @@ void Sema::ProcessPropertyDecl(ObjCPropertyDecl *property) {
       }
     }
 
-    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);
+    GetterMethod = ObjCMethodDecl::Create(
+        Context, Loc, Loc, property->getGetterName(), resultTy, nullptr, CD,
+        !IsClassProperty, /*isVariadic=*/false,
+        /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
+        /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
+        (property->getPropertyImplementation() == ObjCPropertyDecl::Optional)
+            ? ObjCMethodDecl::Optional
+            : ObjCMethodDecl::Required);
     CD->addDecl(GetterMethod);
 
     AddPropertyAttrs(*this, GetterMethod, property);
@@ -2447,6 +2499,7 @@ void Sema::ProcessPropertyDecl(ObjCPropertyDecl *property) {
                                nullptr, CD, !IsClassProperty,
                                /*isVariadic=*/false,
                                /*isPropertyAccessor=*/true,
+                               /*isSynthesizedAccessorStub=*/false,
                                /*isImplicitlyDeclared=*/true,
                                /*isDefined=*/false,
                                (property->getPropertyImplementation() ==
diff --git a/clang/lib/Sema/SemaPseudoObject.cpp b/clang/lib/Sema/SemaPseudoObject.cpp
index 06bcd8d00ded7..602806968ced2 100644
--- a/clang/lib/Sema/SemaPseudoObject.cpp
+++ b/clang/lib/Sema/SemaPseudoObject.cpp
@@ -1190,16 +1190,15 @@ bool ObjCSubscriptOpBuilder::findAtIndexGetter() {
                                              true /*instance*/);
 
   if (!AtIndexGetter && S.getLangOpts().DebuggerObjCLiteral) {
-    AtIndexGetter = ObjCMethodDecl::Create(S.Context, SourceLocation(),
-                           SourceLocation(), AtIndexGetterSelector,
-                           S.Context.getObjCIdType() /*ReturnType*/,
-                           nullptr /*TypeSourceInfo */,
-                           S.Context.getTranslationUnitDecl(),
-                           true /*Instance*/, false/*isVariadic*/,
-                           /*isPropertyAccessor=*/false,
-                           /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
-                           ObjCMethodDecl::Required,
-                           false);
+    AtIndexGetter = ObjCMethodDecl::Create(
+        S.Context, SourceLocation(), SourceLocation(), AtIndexGetterSelector,
+        S.Context.getObjCIdType() /*ReturnType*/, nullptr /*TypeSourceInfo */,
+        S.Context.getTranslationUnitDecl(), true /*Instance*/,
+        false /*isVariadic*/,
+        /*isPropertyAccessor=*/false,
+        /*isSynthesizedAccessorStub=*/false,
+        /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
+        ObjCMethodDecl::Required, false);
     ParmVarDecl *Argument = ParmVarDecl::Create(S.Context, AtIndexGetter,
                                                 SourceLocation(), SourceLocation(),
                                                 arrayRef ? &S.Context.Idents.get("index")
@@ -1303,6 +1302,7 @@ bool ObjCSubscriptOpBuilder::findAtIndexSetter() {
         ReturnType, ReturnTInfo, S.Context.getTranslationUnitDecl(),
         true /*Instance*/, false /*isVariadic*/,
         /*isPropertyAccessor=*/false,
+        /*isSynthesizedAccessorStub=*/false,
         /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
         ObjCMethodDecl::Required, false);
     SmallVector<ParmVarDecl *, 2> Params;
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 9aa8c77c62319..21d3da90de11c 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -1019,6 +1019,7 @@ void ASTDeclReader::VisitObjCMethodDecl(ObjCMethodDecl *MD) {
   MD->setInstanceMethod(Record.readInt());
   MD->setVariadic(Record.readInt());
   MD->setPropertyAccessor(Record.readInt());
+  MD->setSynthesizedAccessorStub(Record.readInt());
   MD->setDefined(Record.readInt());
   MD->setOverriding(Record.readInt());
   MD->setHasSkippedBody(Record.readInt());
@@ -1313,6 +1314,8 @@ void ASTDeclReader::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
   D->setPropertyDecl(ReadDeclAs<ObjCPropertyDecl>());
   D->PropertyIvarDecl = ReadDeclAs<ObjCIvarDecl>();
   D->IvarLoc = ReadSourceLocation();
+  D->setGetterMethodDecl(ReadDeclAs<ObjCMethodDecl>());
+  D->setSetterMethodDecl(ReadDeclAs<ObjCMethodDecl>());
   D->setGetterCXXConstructor(Record.readExpr());
   D->setSetterCXXAssignment(Record.readExpr());
 }
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index 039b57f88e736..b9ee8e817190f 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -673,6 +673,7 @@ void ASTDeclWriter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
   Record.push_back(D->isInstanceMethod());
   Record.push_back(D->isVariadic());
   Record.push_back(D->isPropertyAccessor());
+  Record.push_back(D->isSynthesizedAccessorStub());
   Record.push_back(D->isDefined());
   Record.push_back(D->isOverriding());
   Record.push_back(D->hasSkippedBody());
@@ -884,6 +885,8 @@ void ASTDeclWriter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
   Record.AddDeclRef(D->getPropertyDecl());
   Record.AddDeclRef(D->getPropertyIvarDecl());
   Record.AddSourceLocation(D->getPropertyIvarDeclLoc());
+  Record.AddDeclRef(D->getGetterMethodDecl());
+  Record.AddDeclRef(D->getSetterMethodDecl());
   Record.AddStmt(D->getGetterCXXConstructor());
   Record.AddStmt(D->getSetterCXXAssignment());
   Code = serialization::DECL_OBJC_PROPERTY_IMPL;
diff --git a/clang/lib/StaticAnalyzer/Checkers/DirectIvarAssignment.cpp b/clang/lib/StaticAnalyzer/Checkers/DirectIvarAssignment.cpp
index 0058f3d3881fc..0c46447e19853 100644
--- a/clang/lib/StaticAnalyzer/Checkers/DirectIvarAssignment.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/DirectIvarAssignment.cpp
@@ -144,6 +144,8 @@ void DirectIvarAssignment::checkASTDecl(const ObjCImplementationDecl *D,
       continue;
 
     const Stmt *Body = M->getBody();
+    if (M->isSynthesizedAccessorStub())
+      continue;
     assert(Body);
 
     MethodCrawler MC(IvarToPropMap, M->getCanonicalDecl(), InterD, BR, this,
diff --git a/clang/lib/StaticAnalyzer/Core/CallEvent.cpp b/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
index d95f809bec1aa..e7408b805fa85 100644
--- a/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
@@ -1080,7 +1080,7 @@ ObjCMessageKind ObjCMethodCall::getMessageKind() const {
 
 const ObjCPropertyDecl *ObjCMethodCall::getAccessedProperty() const {
   // Look for properties accessed with property syntax (foo.bar = ...)
-  if ( getMessageKind() == OCM_PropertyAccess) {
+  if (getMessageKind() == OCM_PropertyAccess) {
     const PseudoObjectExpr *POE = getContainingPseudoObjectExpr();
     assert(POE && "Property access without PseudoObjectExpr?");
 
diff --git a/clang/test/AST/ast-dump-decl-json.m b/clang/test/AST/ast-dump-decl-json.m
index 235533d0bff9b..168b1f5ab29dc 100644
--- a/clang/test/AST/ast-dump-decl-json.m
+++ b/clang/test/AST/ast-dump-decl-json.m
@@ -1475,7 +1475,173 @@ void f() {
 // CHECK-NEXT:      "qualType": "int"
 // CHECK-NEXT:     }
 // CHECK-NEXT:    }
-// CHECK-NEXT:   }
+// CHECK-NEXT:   },
+// CHECK-NEXT:   {
+// CHECK-NEXT:     "id": "0x{{.*}}", 
+// CHECK-NEXT:     "kind": "ObjCMethodDecl",
+// CHECK-NEXT:     "loc": {
+// CHECK-NEXT:       "offset": 1109,
+// CHECK-NEXT:       "line": 70,
+// CHECK-NEXT:       "col": 1,
+// CHECK-NEXT:       "tokLen": 1
+// CHECK-NEXT:     },
+// CHECK-NEXT:     "range": {
+// CHECK-NEXT:       "begin": {
+// CHECK-NEXT:         "offset": 1109,
+// CHECK-NEXT:         "col": 1,
+// CHECK-NEXT:         "tokLen": 1
+// CHECK-NEXT:       },
+// CHECK-NEXT:       "end": {
+// CHECK-NEXT:         "offset": 1121,
+// CHECK-NEXT:         "col": 13,
+// CHECK-NEXT:         "tokLen": 3
+// CHECK-NEXT:       }
+// CHECK-NEXT:     },
+// CHECK-NEXT:     "isImplicit": true,
+// CHECK-NEXT:     "name": "getterFoo",
+// CHECK-NEXT:     "returnType": {
+// CHECK-NEXT:       "qualType": "int"
+// CHECK-NEXT:     },
+// CHECK-NEXT:     "instance": true
+// CHECK-NEXT:   },
+// CHECK-NEXT:   {
+// CHECK-NEXT:     "id": "0x{{.*}}",
+// CHECK-NEXT:     "kind": "ObjCMethodDecl",
+// CHECK-NEXT:     "loc": {
+// CHECK-NEXT:       "offset": 1109,
+// CHECK-NEXT:       "col": 1,
+// CHECK-NEXT:       "tokLen": 1
+// CHECK-NEXT:     },
+// CHECK-NEXT:     "range": {
+// CHECK-NEXT:       "begin": {
+// CHECK-NEXT:         "offset": 1109,
+// CHECK-NEXT:         "col": 1,
+// CHECK-NEXT:         "tokLen": 1
+// CHECK-NEXT:       },
+// CHECK-NEXT:       "end": {
+// CHECK-NEXT:         "offset": 1121,
+// CHECK-NEXT:         "col": 13,
+// CHECK-NEXT:         "tokLen": 3
+// CHECK-NEXT:       }
+// CHECK-NEXT:     },
+// CHECK-NEXT:     "isImplicit": true,
+// CHECK-NEXT:     "name": "setterFoo:",
+// CHECK-NEXT:     "returnType": {
+// CHECK-NEXT:       "qualType": "void"
+// CHECK-NEXT:     },
+// CHECK-NEXT:     "instance": true,
+// CHECK-NEXT:     "inner": [
+// CHECK-NEXT:       {
+// CHECK-NEXT:         "id": "0x{{.*}}",
+// CHECK-NEXT:         "kind": "ParmVarDecl",
+// CHECK-NEXT:         "loc": {
+// CHECK-NEXT:           "offset": 1033,
+// CHECK-NEXT:           "line": 63,
+// CHECK-NEXT:           "col": 52,
+// CHECK-NEXT:           "tokLen": 3
+// CHECK-NEXT:         },
+// CHECK-NEXT:         "range": {
+// CHECK-NEXT:           "begin": {
+// CHECK-NEXT:             "offset": 1033,
+// CHECK-NEXT:             "col": 52,
+// CHECK-NEXT:             "tokLen": 3
+// CHECK-NEXT:           },
+// CHECK-NEXT:           "end": {
+// CHECK-NEXT:             "offset": 1033,
+// CHECK-NEXT:             "col": 52,
+// CHECK-NEXT:             "tokLen": 3
+// CHECK-NEXT:           }
+// CHECK-NEXT:         },
+// CHECK-NEXT:         "name": "foo",
+// CHECK-NEXT:         "type": {
+// CHECK-NEXT:           "qualType": "int"
+// CHECK-NEXT:         }
+// CHECK-NEXT:       }
+// CHECK-NEXT:      ]
+// CHECK-NEXT:    },
+// CHECK-NEXT:    {
+// CHECK-NEXT:      "id": "0x{{.*}}",
+// CHECK-NEXT:      "kind": "ObjCMethodDecl",
+// CHECK-NEXT:      "loc": {
+// CHECK-NEXT:        "offset": 1128,
+// CHECK-NEXT:        "line": 71,
+// CHECK-NEXT:        "col": 1,
+// CHECK-NEXT:        "tokLen": 1
+// CHECK-NEXT:      },
+// CHECK-NEXT:      "range": {
+// CHECK-NEXT:        "begin": {
+// CHECK-NEXT:          "offset": 1128,
+// CHECK-NEXT:          "col": 1,
+// CHECK-NEXT:          "tokLen": 1
+// CHECK-NEXT:        },
+// CHECK-NEXT:        "end": {
+// CHECK-NEXT:          "offset": 1140,
+// CHECK-NEXT:          "col": 13,
+// CHECK-NEXT:          "tokLen": 3
+// CHECK-NEXT:        }
+// CHECK-NEXT:      },
+// CHECK-NEXT:      "isImplicit": true,
+// CHECK-NEXT:      "name": "bar",
+// CHECK-NEXT:      "returnType": {
+// CHECK-NEXT:        "qualType": "int"
+// CHECK-NEXT:      },
+// CHECK-NEXT:      "instance": true
+// CHECK-NEXT:    },
+// CHECK-NEXT:    {
+// CHECK-NEXT:      "id": "0x{{.*}}",
+// CHECK-NEXT:      "kind": "ObjCMethodDecl",
+// CHECK-NEXT:      "loc": {
+// CHECK-NEXT:        "offset": 1128,
+// CHECK-NEXT:        "col": 1,
+// CHECK-NEXT:        "tokLen": 1
+// CHECK-NEXT:      },
+// CHECK-NEXT:      "range": {
+// CHECK-NEXT:        "begin": {
+// CHECK-NEXT:          "offset": 1128,
+// CHECK-NEXT:          "col": 1,
+// CHECK-NEXT:          "tokLen": 1
+// CHECK-NEXT:        },
+// CHECK-NEXT:        "end": {
+// CHECK-NEXT:          "offset": 1140,
+// CHECK-NEXT:          "col": 13,
+// CHECK-NEXT:          "tokLen": 3
+// CHECK-NEXT:        }
+// CHECK-NEXT:      },
+// CHECK-NEXT:      "isImplicit": true,
+// CHECK-NEXT:      "name": "setBar:",
+// CHECK-NEXT:      "returnType": {
+// CHECK-NEXT:        "qualType": "void"
+// CHECK-NEXT:      },
+// CHECK-NEXT:      "instance": true,
+// CHECK-NEXT:      "inner": [
+// CHECK-NEXT:        {
+// CHECK-NEXT:          "id": "0x{{.*}}",
+// CHECK-NEXT:          "kind": "ParmVarDecl",
+// CHECK-NEXT:          "loc": {
+// CHECK-NEXT:            "offset": 1052,
+// CHECK-NEXT:            "line": 64,
+// CHECK-NEXT:            "col": 15,
+// CHECK-NEXT:            "tokLen": 3
+// CHECK-NEXT:          },
+// CHECK-NEXT:          "range": {
+// CHECK-NEXT:            "begin": {
+// CHECK-NEXT:              "offset": 1052,
+// CHECK-NEXT:              "col": 15,
+// CHECK-NEXT:              "tokLen": 3
+// CHECK-NEXT:            },
+// CHECK-NEXT:            "end": {
+// CHECK-NEXT:              "offset": 1052,
+// CHECK-NEXT:              "col": 15,
+// CHECK-NEXT:              "tokLen": 3
+// CHECK-NEXT:            }
+// CHECK-NEXT:          },
+// CHECK-NEXT:          "name": "bar",
+// CHECK-NEXT:          "type": {
+// CHECK-NEXT:            "qualType": "int"
+// CHECK-NEXT:          }
+// CHECK-NEXT:        }
+// CHECK-NEXT:      ]
+// CHECK-NEXT:    }
 // CHECK-NEXT:  ]
 // CHECK-NEXT: }
 
diff --git a/clang/test/Analysis/Inputs/expected-plists/nullability-notes.m.plist b/clang/test/Analysis/Inputs/expected-plists/nullability-notes.m.plist
index 314af1e4c952b..5e915d63ffde8 100644
--- a/clang/test/Analysis/Inputs/expected-plists/nullability-notes.m.plist
+++ b/clang/test/Analysis/Inputs/expected-plists/nullability-notes.m.plist
@@ -188,7 +188,6 @@
   <dict>
    <key>0</key>
    <array>
-    <integer>10</integer>
     <integer>14</integer>
     <integer>16</integer>
     <integer>17</integer>
diff --git a/clang/test/CodeGenObjC/debug-info-synthesis.m b/clang/test/CodeGenObjC/debug-info-synthesis.m
index f954256282814..7fbbc6dd3182e 100644
--- a/clang/test/CodeGenObjC/debug-info-synthesis.m
+++ b/clang/test/CodeGenObjC/debug-info-synthesis.m
@@ -30,8 +30,8 @@ int main(int argc, char *argv[]) {
   }
 }
 
-// CHECK: ![[FILE:.*]] = !DIFile(filename: "{{[^"]+}}foo.h"
+// CHECK: ![[FILE:.*]] = !DIFile(filename: "foo.m"
 // CHECK: !DISubprogram(name: "-[Foo setDict:]"
 // CHECK-SAME:          file: ![[FILE]],
-// CHECK-SAME:          line: 8,
+// CHECK-SAME:          line: 7,
 // CHECK-SAME:          DISPFlagLocalToUnit | DISPFlagDefinition
diff --git a/clang/test/CodeGenObjC/debug-property-synth.m b/clang/test/CodeGenObjC/debug-property-synth.m
index 124c61ea88cde..ddcf4d998c5cd 100644
--- a/clang/test/CodeGenObjC/debug-property-synth.m
+++ b/clang/test/CodeGenObjC/debug-property-synth.m
@@ -7,6 +7,10 @@
 @interface I {
   int _p1;
 }
+@property int p1;
+@end
+
+@implementation I
 // Test that the linetable entries for the synthesized getter and
 // setter are correct.
 //
@@ -22,10 +26,6 @@ @interface I {
 // CHECK: ![[DBG1]] = !DILocation(line: [[@LINE+3]],
 // CHECK: !DISubprogram(name: "-[I setP1:]",{{.*}} line: [[@LINE+2]],{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
 // CHECK: ![[DBG2]] = !DILocation(line: [[@LINE+1]],
-@property int p1;
-@end
-
-@implementation I
 @synthesize p1 = _p1;
 @end
 
diff --git a/clang/test/CodeGenObjC/debuginfo-properties.m b/clang/test/CodeGenObjC/debuginfo-properties.m
index c0de620abd966..53f5e2de890bd 100644
--- a/clang/test/CodeGenObjC/debuginfo-properties.m
+++ b/clang/test/CodeGenObjC/debuginfo-properties.m
@@ -11,19 +11,6 @@ @interface NSObject <NSObject> {}
 
 @protocol HasASelection <NSObject>
 @property (nonatomic, retain) Selection* selection;
-// CHECK: !DISubprogram(name: "-[MyClass selection]"
-// CHECK-SAME:          line: [[@LINE-2]]
-// CHECK-SAME:          DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK: !DISubprogram(name: "-[MyClass setSelection:]"
-// CHECK-SAME:          line: [[@LINE-5]]
-// CHECK-SAME:          DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK: !DISubprogram(name: "-[OtherClass selection]"
-// CHECK-SAME:          line: [[@LINE-8]]
-// CHECK-SAME:          DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK: !DISubprogram(name: "-[OtherClass setSelection:]"
-// CHECK-SAME:          line: [[@LINE-11]]
-// CHECK-SAME:          DISPFlagLocalToUnit | DISPFlagDefinition
-
 @end
 
 @interface MyClass : NSObject <HasASelection> {
@@ -33,6 +20,12 @@ @interface MyClass : NSObject <HasASelection> {
 
 @implementation MyClass
 @synthesize selection = _selection;
+// CHECK: !DISubprogram(name: "-[MyClass selection]"
+// CHECK-SAME:          line: [[@LINE-2]]
+// CHECK-SAME:          DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK: !DISubprogram(name: "-[MyClass setSelection:]"
+// CHECK-SAME:          line: [[@LINE-5]]
+// CHECK-SAME:          DISPFlagLocalToUnit | DISPFlagDefinition
 @end
 
 @interface OtherClass : NSObject <HasASelection> {
@@ -41,4 +34,10 @@ @interface OtherClass : NSObject <HasASelection> {
 @end
 @implementation OtherClass
 @synthesize selection = _selection;
+// CHECK: !DISubprogram(name: "-[OtherClass selection]"
+// CHECK-SAME:          line: [[@LINE-2]]
+// CHECK-SAME:          DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK: !DISubprogram(name: "-[OtherClass setSelection:]"
+// CHECK-SAME:          line: [[@LINE-5]]
+// CHECK-SAME:          DISPFlagLocalToUnit | DISPFlagDefinition
 @end
diff --git a/clang/test/CodeGenObjC/instance-method-metadata.m b/clang/test/CodeGenObjC/instance-method-metadata.m
index 96f499c9fa94a..e08de8fdacec2 100644
--- a/clang/test/CodeGenObjC/instance-method-metadata.m
+++ b/clang/test/CodeGenObjC/instance-method-metadata.m
@@ -1,6 +1,5 @@
 // REQUIRES: x86-registered-target
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -S -o %t %s 
-// RUN: FileCheck < %t %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -S %s -o - | FileCheck %s
 
 // rdar://9072317
 
diff --git a/clang/test/SemaObjC/iboutlet.m b/clang/test/SemaObjC/iboutlet.m
index 7bd86d4668b3a..1d8ec9965c2af 100644
--- a/clang/test/SemaObjC/iboutlet.m
+++ b/clang/test/SemaObjC/iboutlet.m
@@ -11,7 +11,7 @@
 
 IBInspectable @property (readonly) IBOutlet NSView *myView1; // expected-warning {{readonly IBOutlet property 'myView1' when auto-synthesized may not work correctly with 'nib' loader}} expected-note {{property should be changed to be readwrite}}
 
-@property (getter = MyGetter, READONLY) IBOutlet NSView *myView2; // expected-warning {{readonly IBOutlet property 'myView2' when auto-synthesized may not work correctly with 'nib' loader}}
+@property (getter = MyGetter2, READONLY) IBOutlet NSView *myView2; // expected-warning {{readonly IBOutlet property 'myView2' when auto-synthesized may not work correctly with 'nib' loader}}
 
 @end
 
diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
index 48e8b61515812..ada5d7551d731 100644
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -629,6 +629,11 @@ bool CursorVisitor::VisitDeclContext(DeclContext *DC) {
     Decl *D = *I;
     if (D->getLexicalDeclContext() != DC)
       continue;
+    // Filter out synthesized property accessor redeclarations.
+    if (isa<ObjCImplDecl>(DC))
+      if (auto *OMD = dyn_cast<ObjCMethodDecl>(D))
+        if (OMD->isSynthesizedAccessorStub())
+          continue;
     const Optional<bool> V = handleDeclForVisitation(D);
     if (!V.hasValue())
       continue;