--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/SemaObjC/continuation-class-err.m	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,51 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wno-objc-root-class %s
+
+@interface ReadOnly 
+{
+  id _object;
+  id _object1;
+}
+@property(readonly) id object;
+@property(readwrite, assign) id object1; // expected-note {{property declared here}}
+@property (readonly) int indentLevel;
+@end
+
+@interface ReadOnly ()
+@property(readwrite, copy) id object; // Ok. declaring memory model in class extension - primary has none.
+@property(readonly) id object1; // expected-error {{illegal redeclaration of property in class extension 'ReadOnly' (attribute must be 'readwrite', while its primary must be 'readonly')}}
+@property (readwrite, assign) int indentLevel; // OK. assign the default in any case.
+@end
+
+@protocol Proto
+  @property (copy) id fee; // expected-note {{property declared here}}
+@end
+
+@protocol Foo<Proto>
+  @property (copy) id foo; // expected-note {{property declared here}}
+@end
+
+@interface Bar  <Foo> {
+        id _foo;
+        id _fee;
+}
+@end
+
+@interface Bar ()
+@property (copy) id foo; // expected-error {{illegal redeclaration of property in class extension 'Bar' (attribute must be 'readwrite', while its primary must be 'readonly')}}
+@property (copy) id fee; // expected-error {{illegal redeclaration of property in class extension 'Bar' (attribute must be 'readwrite', while its primary must be 'readonly')}}
+@end
+
+@implementation Bar
+@synthesize foo = _foo;
+@synthesize fee = _fee;
+@end
+
+// rdar://10752081
+@interface MyOtherClass() // expected-error {{cannot find interface declaration for 'MyOtherClass'}}
+{
+ id array;
+}
+@end
+
+@implementation MyOtherClass // expected-warning {{cannot find interface declaration for 'MyOtherClass'}}
+@end