🚀 go-pugleaf

    >If you rely on incomplete data for doing maintenance, bugs will
    >result.  When you change the way to call foo, you need to find *all*
    >the calls, not just those that happen to be enabled on the target you
    >are using today.

	    I belive the only downside of this is that you have to build
	    the call tree once for each target you are supporting. Its a
	    productivity hit but, in my mind this is a hit worth taking.

Consider a program like GCC that supports many dozens of targets.
This is not practical.

I can't tell you what program to write.  (I almost said, "You can
write whatever you like," but that's not true any more--ask
lpf@uunet.uu.net about why it's not true.)  All I can say is what sort
of cross-referencer I'd consider an enhancement to the GNU project.