which source package has the source for javac in openjdk?

[David Goodenough <david.goodenough@linkchoose.co.uk>]

I am trying to debug a problem with an annotation processor, and I need
to look at the source for javac to debug it.  Openjdk-6-source only contains
the source for the runtime, and there seem to be no other source packages
referenced so I am a bit lost as to where to look.

David