You probably already know that the default Java compiler (javac) can output a bunch of options if you run it as javac -h. You can also get the extended list of Oracle specific command switches using “javac -X”. Until today, I’d not realised that javac has even more command line switches, called “hidden options”. It’s possible to call them using a syntax like so -XD-hidden-option-name.

Now, I wonder if ecj has the same sort of thing. It’d be handy….

Update: it doesn’t look like it. *unhappy face*