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From: Stefan Monnier <monnier@iro.umontreal.ca>
To: Eli Zaretskii <eliz@gnu.org>
Cc: 39233@debbugs.gnu.org, stefan@marxist.se
Subject: bug#39233: .elc file - possibly outdated backward compatibility comments
Date: Fri, 24 Jan 2020 12:29:03 -0500	[thread overview]
Message-ID: <jwvh80k4vsf.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: <83v9p0ri8g.fsf@gnu.org> (Eli Zaretskii's message of "Fri, 24 Jan 2020 17:23:27 +0200")

> for the use cases I need this -- which is running old Emacs binaries
> to quickly bisect bugs in C code or in preloaded Lisp -- this doesn't
> sound like a terrible problem.  As long as this use case works as well
> (or as badly) as it did before, modulo the warning.

Yes, it will work just as well/poorly, modulo the warning.

> I feared that this won't work at all, because the *.elc files lack
> something which old Emacs binaries will look for at load time.

No, there should be no change in this respect: when loading a .elc file,
the only thing we look for (other than actually reading&evalling the
sexps) is to look for some kind of "version number" which is encoded in
the 4th byte of the file, a part that we have no intention to
change, AFAIK.


        Stefan






  reply	other threads:[~2020-01-24 17:29 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-22  8:44 bug#39233: .elc file - possibly outdated backward compatibility comments Stefan Kangas
2020-01-22 17:13 ` Eli Zaretskii
2020-01-23 16:26 ` Stefan Monnier
2020-01-24  9:20   ` Eli Zaretskii
2020-01-24 14:22     ` Stefan Monnier
2020-01-24 14:36       ` Lars Ingebrigtsen
2020-01-24 16:08         ` Stefan Kangas
2020-01-24 15:23       ` Eli Zaretskii
2020-01-24 17:29         ` Stefan Monnier [this message]
2020-01-24 18:45           ` Stefan Monnier
2020-01-24 19:06             ` Stefan Kangas
2020-01-24 19:14               ` Stefan Monnier
2020-01-24 19:19             ` Glenn Morris
2020-01-24 20:08             ` Eli Zaretskii
2020-09-21 12:56             ` Lars Ingebrigtsen

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