--- old/src/hotspot/share/gc/parallel/psMarkSweep.hpp	2018-05-08 09:41:05.682355371 +0200
+++ new/src/hotspot/share/gc/parallel/psMarkSweep.hpp	2018-05-08 09:41:05.394346472 +0200
@@ -27,6 +27,7 @@
 
 #include "gc/serial/markSweep.hpp"
 #include "gc/shared/collectorCounters.hpp"
+#include "gc/shared/referenceProcessor.hpp"
 #include "utilities/stack.hpp"
 
 class PSAdaptiveSizePolicy;
@@ -39,6 +40,8 @@
   static jlong               _time_of_last_gc;   // ms
   static CollectorCounters*  _counters;
 
+  static SpanSubjectToDiscoveryClosure _span_discoverer;
+
   // Closure accessors
   static OopClosure* mark_and_push_closure()   { return &MarkSweep::mark_and_push_closure; }
   static VoidClosure* follow_stack_closure()   { return &MarkSweep::follow_stack_closure; }