skipping past nil

[Ginger Booth]

Dear y'all,

    Once upon a time, somewhere, someone recommended turning on a feature
of something, to make Swarm/GNU ObjC programs crash when a message is sent
to a nil pointer.  Unfortunately, I'd already made lots of use of the skip-
on-past-nil-without-notice feature, and decided not to backtrack at the
time.  So my app expects [nil messagecall] to simply, quietly, do nothing.
But someone else is trying to build it on a Linux box, and it crashes on
this construct.

    Could anyone tell me what the magic word was that makes this construct
ignored successfully?  I can't find it in the GNU gcc man page.

Thanks!
    Ginger