gistfile1.txt

(require 'filecache)
(defun file-cache-add-from-file (file &optional prefix)
  "Read filenames from FILE, one line per file, and add them to
the file cache.  If prefix is given, stick that prefix at the
start of every line before adding to file cache."
  (interactive "fAdd files from file: ")
  (set-buffer (get-buffer-create file-cache-buffer))
  (erase-buffer)
  (insert-file file)
  (if (not (eq prefix nil))
      (progn (goto-char 0)
             (replace-regexp "^" prefix)))
  (file-cache-add-from-file-cache-buffer))

(defun file-cache-file-for-dir (file dir)
  (if (file-exists-p file)
      (file-cache-add-from-file file dir)))

(file-cache-file-for-dir "c:/proj/moz/mozilla-central/.git/emacs-file-list"
                         "c:/proj/moz/mozilla-central/")