It's sort of a bug that "make-mode.el" provides 'makefile rather than
'make-mode, isn't it? The following code doesn't quite work the way
I'd expect because of this:
(add-to-list 'after-load-alist
'("sh-script" (progn
(require 'make-mode)
(define-key sh-mode-map
(kbd "C-c C-\\")
#'makefile-backslash-region))))
Let me guess -- historical reasons?