diff -r bcd927639039 -r 05ec778794d0 src/share/classes/com/sun/tools/javac/main/JavaCompiler.java
--- a/src/share/classes/com/sun/tools/javac/main/JavaCompiler.java	Wed May 15 00:00:39 2013 -0700
+++ b/src/share/classes/com/sun/tools/javac/main/JavaCompiler.java	Wed May 15 14:00:31 2013 +0100
@@ -1614,6 +1614,9 @@
                 log.warning("proc.use.proc.or.implicit");
         }
         chk.reportDeferredDiagnostics();
+        if (log.compressedOutput) {
+            log.mandatoryNote(null, "compressed.diags");
+        }
     }
 
     /** Close the compiler, flushing the logs