Re: emacs rendering comparisson between emacs23 and emacs26.3

[Alan Mackenzie <acm@muc.de>]

Hello, Eli.

On Sat, Mar 28, 2020 at 15:05:21 +0300, Eli Zaretskii wrote:
> > Date: Sat, 28 Mar 2020 11:43:01 +0000
> > Cc: rms@gnu.org, rrandresf@gmail.com, emacs-devel@gnu.org
> > From: Alan Mackenzie <acm@muc.de>

> > (defvar loaded-cc-version nil)
> > (defun load-cc-version (dir)
> >   "Load the version of CC Mode contained in directory DIR."
> >   (interactive "D")
> >   (or (string-match "/$" dir)
> >       (setq dir (concat dir "/")))
> >   (let (fname)
> >     ;; `c-fallback-style' gets stuff pushed onto it by loading cc-vars.  So
> >     ;; clear it out first, after a quick and dirty sanity check.
> >     (if (file-exists-p (concat dir "cc-vars.elc"))
> >         (setq c-fallback-style nil))
> >     (mapc (lambda (f)
> >             (condition-case err
> >                 (load-file (setq fname (concat dir "cc-" f ".elc")))
> >               (error (message "Couldn't load %s" fname))))
> >           '("defs" "vars" "fix" "engine" "cmds" "menus"
> >             "align" "styles" "awk" "fonts" "mode"
> >             "subword" "bytecomp" "compat" "guess"))
> >     (setq loaded-cc-version dir)))

> Thanks, but when I use this command to load CC Mode from Emacs 23.4,
> and then visit xdisp.c, I get an error message:

>   File mode specification error: (void-function make-local-hook)

> and CC mode is not turned on.  What am I missing?

make-local-hook was removed from Emacs in around 2010.  I think it still
exists in XEmacs (as much as anything can still be said to exist there).

If you can give me some time to eat my lunch, I'll seek out the
workaround I must have introduced some time after Emacs 23.4.  There may
be one or two other obsolete variables/functions which may now need
workarounds to allow timing of the old CC Mode versions.

-- 
Alan Mackenzie (Nuremberg, Germany).