diff -r bbd1da3f538f -r f3108e56b502 src/share/vm/utilities/ostream.hpp
--- a/src/share/vm/utilities/ostream.hpp	Wed Aug 01 04:19:22 2018 -0400
+++ b/src/share/vm/utilities/ostream.hpp	Thu Aug 02 03:54:51 2018 -0700
@@ -258,6 +258,7 @@
 #ifndef PRODUCT
 // unit test for checking -Xloggc:<filename> parsing result
 void test_loggc_filename();
+void test_snprintf();
 #endif
 
 void ostream_init();