From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.bugs Subject: bug#39233: .elc file - possibly outdated backward compatibility comments Date: Fri, 24 Jan 2020 12:29:03 -0500 Message-ID: References: <87zhefkhi9.fsf@marxist.se> <835zh1rz1o.fsf@gnu.org> <83v9p0ri8g.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="86173"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: 39233@debbugs.gnu.org, stefan@marxist.se To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Fri Jan 24 18:30:38 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 1iv2n0-000MNR-Bn for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 24 Jan 2020 18:30:38 +0100 Original-Received: from localhost ([::1]:45764 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iv2mz-0000UF-ES for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 24 Jan 2020 12:30:37 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:55100) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iv2mR-0000Ak-W5 for bug-gnu-emacs@gnu.org; Fri, 24 Jan 2020 12:30:04 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iv2mQ-0000yv-Oo for bug-gnu-emacs@gnu.org; Fri, 24 Jan 2020 12:30:03 -0500 Original-Received: from debbugs.gnu.org ([209.51.188.43]:48747) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iv2mQ-0000yc-M3 for bug-gnu-emacs@gnu.org; Fri, 24 Jan 2020 12:30:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1iv2mQ-0004bs-IK for bug-gnu-emacs@gnu.org; Fri, 24 Jan 2020 12:30:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Stefan Monnier Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Fri, 24 Jan 2020 17:30:02 +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=B39233.157988695317594 (code B ref 39233); Fri, 24 Jan 2020 17:30:02 +0000 Original-Received: (at 39233) by debbugs.gnu.org; 24 Jan 2020 17:29:13 +0000 Original-Received: from localhost ([127.0.0.1]:54720 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iv2ld-0004Zg-5s for submit@debbugs.gnu.org; Fri, 24 Jan 2020 12:29:13 -0500 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]:18466) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iv2lc-0004ZU-DF for 39233@debbugs.gnu.org; Fri, 24 Jan 2020 12:29:12 -0500 Original-Received: from pmg1.iro.umontreal.ca (localhost.localdomain [127.0.0.1]) by pmg1.iro.umontreal.ca (Proxmox) with ESMTP id CDDC0100A9C; Fri, 24 Jan 2020 12:29:06 -0500 (EST) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg1.iro.umontreal.ca (Proxmox) with ESMTP id 288921009B6; Fri, 24 Jan 2020 12:29:05 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1579886945; bh=/QGX3RK7VGmLg1zJKpIzdCliqWSka8mAMfaoeaVaprk=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=PEOW88Lou3mKdQcqN06YabgWNz8RQ/nhcld4CrXlBZtES5GwZh4SgRSFjcbGZ7NDP NhbnY7HrDiwWGyA+/HLAa6BFGJ71YDMwAf2LX6jQt/hG+HeEy76j54rMs4Ie9k6nQ1 4TdztFPaNakKyhuNI+SixlbEvXPRwo+loVZSun812W5brCVVdP6Tfkr1Vfd4pRagme EO3GnqsNWvVDEuLSdGC9IZJP6/vNlknyhSKwzwxMq8ggWae7h84lezkSjjQoEQ2HzE E/jf9T4IpLLN0uJnnaRh+OSOWfbLOxj2xY5LlPaODS1BU7/NS4cJ/3apLdNvWt1Zrl DwUtc7KuBUNOA== Original-Received: from alfajor (modemcable157.163-203-24.mc.videotron.ca [24.203.163.157]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id A2364121105; Fri, 24 Jan 2020 12:29:04 -0500 (EST) In-Reply-To: <83v9p0ri8g.fsf@gnu.org> (Eli Zaretskii's message of "Fri, 24 Jan 2020 17:23:27 +0200") 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:175236 Archived-At: > 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