From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Drew Adams Newsgroups: gmane.emacs.devel Subject: RE: Preview: portable dumper Date: Sat, 3 Dec 2016 08:14:35 -0800 (PST) Message-ID: <01a025df-3995-4657-9658-72656185873b@default> References: <<<047a67ec-9e29-7e4e-0fb0-24c3e59b5886@dancol.org> <83zikjxt1j.fsf@gnu.org>>> << <8360n6ruzu.fsf@gnu.org>>> << <834m2nplmb.fsf@gnu.org> <83inr2oje6.fsf@gnu.org>>> << <83shq6mlt3.fsf@gnu.org>>> <<>> <<>> <<2b63d48d-a678-49c2-a3a9-4f91d8d8bdb4@default>> <<8337i5mnb5.fsf@gnu.org>> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Trace: blaine.gmane.org 1480781697 25629 195.159.176.226 (3 Dec 2016 16:14:57 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 3 Dec 2016 16:14:57 +0000 (UTC) Cc: emacs-devel@gnu.org, rms@gnu.org, monnier@iro.umontreal.ca To: Eli Zaretskii , Drew Adams Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Dec 03 17:14:52 2016 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cDCxg-0005rR-EV for ged-emacs-devel@m.gmane.org; Sat, 03 Dec 2016 17:14:52 +0100 Original-Received: from localhost ([::1]:51629 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cDCxk-0000tR-8t for ged-emacs-devel@m.gmane.org; Sat, 03 Dec 2016 11:14:56 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:43642) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cDCxd-0000tA-J9 for emacs-devel@gnu.org; Sat, 03 Dec 2016 11:14:50 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cDCxc-0000X5-Mp for emacs-devel@gnu.org; Sat, 03 Dec 2016 11:14:49 -0500 Original-Received: from userp1040.oracle.com ([156.151.31.81]:47330) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cDCxX-0000WA-U7; Sat, 03 Dec 2016 11:14:44 -0500 Original-Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id uB3GEcmf020601 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 3 Dec 2016 16:14:39 GMT Original-Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id uB3GEbui003692 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 3 Dec 2016 16:14:38 GMT Original-Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id uB3GEbaT016607; Sat, 3 Dec 2016 16:14:37 GMT In-Reply-To: <<8337i5mnb5.fsf@gnu.org>> X-Priority: 3 X-Mailer: Oracle Beehive Extensions for Outlook 2.0.1.9.1 (1003210) [OL 12.0.6753.5000 (x86)] X-Source-IP: aserv0022.oracle.com [141.146.126.234] X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] [fuzzy] X-Received-From: 156.151.31.81 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:209984 Archived-At: > > > Only rarely have we made changes that would prevent this. > > > > That used to be the case. Now, nearly every major release is > > incompatible, AFAICT. As far as I can see, long gone are the > > days when you could byte-compile in an older version and use > > the byte-compiled code in a newer version. >=20 > I'm not aware of such problems. AFAIK, we only made an incompatible > change once, in Emacs 23. The byte-compiled files compiled by later ^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^ > versions should all be compatible. If you see a problem with that, > please report it as a bug. A change _in_ 23? Or a change _after_ 23? If the change occurred in 23 then files compiled in 23 should be compatible in later releases. It should not be the case only that files compiled in later releases are compatible with still later releases. I cannot (always) byte-compile in 23 and use the result in later releases, at least. (It depends on the file.) It may or may not represent a hard incompatibility. It might just be a change in a calling sequence or existence of some macros. I don't know, and I don't have the time to dig into it. I do know that I do not hesitate to have conditional code that (normally) is all that's needed, to deal with such changes, and that that no longer suffices. Are you suggesting that if someone can report a true incompatibility introduced after Emacs 23 you will actually change the byte compiler to remove it, and that you will backport that fix to where it was introduced and later releases? (Otherwise, the fix doesn't really help.) You can believe me or not. I am used to conditionalizing code to make it work with multiple releases. And I have always tried, for my own use, to byte-compile in the oldest release possible, so that the result works for all of the releases the particular library supports. I have had to stop compiling (except for testing, to pick up warnings) some libraries because of what I've found to be byte-compilation incompatibility. Yes, my claim remains vague. And yes, I'm anyway glad to hear that there is some profession of still wanting to keep compatibility for future releases. That is a large consolation, for which I am grateful.