--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/SemaObjC/builtin_objc_nslog.m	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -x objective-c %s -fsyntax-only -verify
+
+#include <stdarg.h>
+
+void f1(id arg) {
+  NSLog(@"%@", arg); // expected-warning {{implicitly declaring library function 'NSLog' with type 'void (id, ...)'}} \
+  // expected-note {{include the header <Foundation/NSObjCRuntime.h> or explicitly provide a declaration for 'NSLog'}}
+}
+
+void f2(id str, va_list args) {
+  NSLogv(@"%@", args); // expected-warning {{implicitly declaring library function 'NSLogv' with type }} \
+  // expected-note {{include the header <Foundation/NSObjCRuntime.h> or explicitly provide a declaration for 'NSLogv'}}
+}