It would be good to allow javac plugins to be able to be invoked by default.
To facilitate this, the following method could be added to com.sun.source.util.Plugin
with a default implementation of "return false;"
All plugins found by the service loader that return isDefault:true and which have not been explicitly invoked already from the command line would be invoked with an empty set of args.
As part of this, it would be worth verifying that plugins can be loaded from modules and/or jlinked into an image.