I'm switching over to ASDF from MAKE. I miss the files-in-system function... Consider adding it & make it external?
Here is a quick hack:
(defun files-in-system (system)
(loop for (op . component) in (traverse (make-instance 'load-op)
when (and (typep component 'component)
(stringp (pathname-name (component-pathname component))))
collect (component-pathname component)) :test #'equalp))