Have you ever wanted to just expand macros of GNU as (gas)? It was possible in the days of old. All you need is gasp.

This repo contains the last version of GNU binutils, that contained the gasp binary. In order to get that beloved bin, run in the main dir:

./configure
cd bfd
make
cd ../libiberty/
make
cd ../gas
make gasp-new

The result will be placed in gas/gasp-new. Finally, take a look at the man page or the reference manual and party like it's 1999.

Footnote: gasp wasn't compiling on the source commit by default, so I hacked the makefiles a bit, therefore don't expect as to work. Also, don't expect it to parse anything remotely recent.