diff -r 407a8495d4b3 -r a12c9536d8a6 src/hotspot/share/logging/logTag.hpp
--- a/src/hotspot/share/logging/logTag.hpp	Fri Dec 08 13:47:08 2017 +0100
+++ b/src/hotspot/share/logging/logTag.hpp	Mon Feb 19 09:16:04 2018 +0100
@@ -192,6 +192,7 @@
   }
 
   static LogTag::type from_string(const char *str);
+  static void list_tags(outputStream* out);
 
  private:
   static const char* _name[];