From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#39233: .elc file - possibly outdated backward compatibility comments Date: Fri, 24 Jan 2020 17:23:27 +0200 Message-ID: <83v9p0ri8g.fsf@gnu.org> References: <87zhefkhi9.fsf@marxist.se> <835zh1rz1o.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="6285"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 39233@debbugs.gnu.org, stefan@marxist.se To: Stefan Monnier Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Fri Jan 24 16:24:12 2020 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1iv0od-0001bR-Oj for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 24 Jan 2020 16:24:11 +0100 Original-Received: from localhost ([::1]:43592 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iv0oc-0002to-T3 for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 24 Jan 2020 10:24:10 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:52569) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iv0oV-0002tU-W4 for bug-gnu-emacs@gnu.org; Fri, 24 Jan 2020 10:24:04 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iv0oU-0001zJ-KP for bug-gnu-emacs@gnu.org; Fri, 24 Jan 2020 10:24:03 -0500 Original-Received: from debbugs.gnu.org ([209.51.188.43]:48639) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iv0oU-0001zC-H8 for bug-gnu-emacs@gnu.org; Fri, 24 Jan 2020 10:24:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1iv0oU-00041W-D5 for bug-gnu-emacs@gnu.org; Fri, 24 Jan 2020 10:24:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Fri, 24 Jan 2020 15:24:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 39233 X-GNU-PR-Package: emacs Original-Received: via spool by 39233-submit@debbugs.gnu.org id=B39233.157987943215451 (code B ref 39233); Fri, 24 Jan 2020 15:24:02 +0000 Original-Received: (at 39233) by debbugs.gnu.org; 24 Jan 2020 15:23:52 +0000 Original-Received: from localhost ([127.0.0.1]:54612 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iv0oJ-000417-O1 for submit@debbugs.gnu.org; Fri, 24 Jan 2020 10:23:51 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:43454) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iv0oI-00040w-Gp for 39233@debbugs.gnu.org; Fri, 24 Jan 2020 10:23:50 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:34261) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1iv0oC-0001uF-SE; Fri, 24 Jan 2020 10:23:44 -0500 Original-Received: from [176.228.60.248] (port=1554 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1iv0oB-00041A-OB; Fri, 24 Jan 2020 10:23:44 -0500 In-reply-to: (message from Stefan Monnier on Fri, 24 Jan 2020 09:22:49 -0500) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.51.188.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:175225 Archived-At: > From: Stefan Monnier > Cc: stefan@marxist.se, 39233@debbugs.gnu.org > Date: Fri, 24 Jan 2020 09:22:49 -0500 > > > Will these changes still allow old Emacs binaries to load *.elc files > > compiled by Emacs after these changes? > > New Emacsen loading old .elc won't be affected. > > Old Emacsen loading .elc files compiled by new Emacsen is something that > has always been risky, tho it has sometimes worked. My proposal is to > make it emit a warning (so it will work as much as it does now, but > will bring to the attention of the user that it's in murky territory). A warning is a (minor) annoyance. Maybe someone will be annoyed enough to complain (we shall see), but 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. 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. Thanks.