bug#58025: [PATCH] Ensure `byte-compile-dest-file-function' is used

[Zack Weinberg]

On Sat, Sep 24, 2022, at 5:45 AM, Richard Hopkins wrote:
> On 2022-09-23 16:15, Zack Weinberg wrote:
>> Thank you for the patch.  Are you able to test it with a version of
>> GNU Emacs older than 23.2?  I see that you tested it with XEmacs 21,
>> but as I recall there were quite substantial differences between
>> XEmacs 21 and GNU Emacs of similar vintage.
>
> I've now managed to test this on Emacs 21.4.1 (Slackware 12.0) and
> the byte compilation works - loading bytecomp is fine, and
> `byte-compile-dest-file' is defined as expected.  The other patch
> to respect silent rules also works on 21.4.1.
>
> If we do need to support that far back I will investigate the "-Q"
> / "--no-site-file" handling to improve compatibility across the
> board.

I'm not an official maintainer for Automake, but I think we probably
don't have to worry about Emacs any older than v21.  Would anyone
else like to express an opinion?

> "-Q" will error before GNU Emacs 22, and is ignored on XEmacs.
>
> "-no-site-file" (single hypen) should be used instead of
> "--no-site-file" as it works on all of them.
>
> "-Q" also shouldn't be specified on later GNU Emacs as it affects
> the result of `am_cv_lispdir' calculation due to excluding
> site lisp directories from `load-path' which it's trying to find.
> This is because "-Q" also adds "--no-site-lisp" in later GNU Emacs.
>
> So, the plan will be to not use "-Q" and to use "-q -no-site-file"
> instead.

This sounds like it would be a worthwhile change regardless of where
we decide to draw the line on supporting old versions of Emacs.

zw