Why not gnat Ada in gcc?

[Richard Kenner]

    But _I_ am not imposing any further restrictions.  You did not sign an
    NDA with me.  As far as I am concerned you can do anything with it
    that you want.

In that case you are violating the NDA!  You can't do this without
violating one or the other.  If you give it to a third party without
saying it's under the NDA ("a further restriction" and thus not permitted
by the GPL), you are violating the NDA.