C/C++ front-end extension a la SWIG?

[thi]

   From: Mike Stump <mrs@windriver.com>
   Date: Wed, 5 Jul 2000 17:47:55 -0700 (PDT)

   How about this, we settle on something like swig, and have gcc/g++
   generate swig friendly data into a file, and then have swig read that
   file and generate what it needs to.  The xref stuff in the compiler
   might be worth dusting off, it might be kinda like what one wants
   (I've not thought about this much, I've not studied swig).  Should be
   fairly low maintenance, can be used/reused for other languages
   (GNU Fortran/GNU Ada...)

this sounds ideal.  i suppose the next step would be for me to grab gcc
source and have a look around...  could you recommend where to begin?

thanks,
thi