Hello,
While fixing lp bug #1414277 https://bugs.launchpad.net/cffi/+bug/1414277 I needed to use a couple of utilities provided by UIOP that would have been a pain to implement in CFFI-SYS.
UIOP is ASDF's utility library -- it is also available standalone via Quicklisp -- and next version of CFFI will depend on it.
I hope that's not inconvenient to anyone. :-)
Cheers,