How can I determine which files are used?

[Gerald Champagne <gerald.champagne@esstech.com>]

Is there a recommended method of determining which files in the
Linux source tree are used with a given .config file?  I've already
removed the obvious things like unused entries in the arch directory
and a couple of driver directories, but is there a way to generate a
list of only the files that are used?

I know I've read discussions about someday splitting up the source code
into smaller blocks, but can someone point me towards information on how
to prune the existing source tree?

Thanks.

Gerald