if (executionTag == null)
executionTag = new CompoundAopTag();
if (executionTag.entryTag != null)
throw new WatchAlreadySetException("JVMAspectInterface.setMethodEntryWatch:" + m);
else
executionTag.entryTag=aopTag;
// if the exit tag is set and 'bci=0' is an end location, we use the
// execution tag; otherwise we use our own tag