--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/SemaObjC/protocols.m	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,67 @@
+// RUN: %clang_cc1 -fsyntax-only -Wno-deprecated-declarations -verify %s
+
+@interface INTF1
+@required  // expected-error {{directive may only be specified in protocols only}}
+- (int) FooBar;
+- (int) FooBar1;
+- (int) FooBar2;
+@optional  // expected-error {{directive may only be specified in protocols only}}
++ (int) C;
+
+- (int)I;
+@end
+
+@protocol p1,p2,p3;
+
+@protocol p1;
+
+@protocol PROTO1
+@required 
+- (int) FooBar;
+@optional
+- (void) MyMethod1;
++ (int) S;
+@end
+
+
+@protocol PROTO2<p1>
+@end
+
+@protocol p1 @end
+
+@protocol PROTO<p1>     // expected-note {{previous definition is here}}
+@end
+
+@protocol PROTO<p1>	// expected-warning {{duplicate protocol definition of 'PROTO'}}
+@end
+
+@protocol PROTO3<p1, p1>
+@end
+
+@protocol p2 <p1>
+@end
+
+@protocol PROTO4 <p1, p2, PROTO, PROTO3, p3> 
+@end
+
+
+// rdar://6771034
+@protocol XX;
+@protocol YY <XX>  // Use of declaration of XX here should not cause a warning.
+- zz;
+@end
+
+
+// Detect circular dependencies.
+@protocol B;
+@protocol C < B > // expected-note{{previous definition is here}}
+@end
+@protocol A < C > 
+@end
+@protocol B < A > // expected-error{{protocol has circular dependency}}
+@end
+
+@protocol P
+- (int)test:(int)param, ..; // expected-warning{{type specifier missing}} \
+                      // expected-error{{expected ';' after method prototype}}
+@end