From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Lars Brinkhoff Newsgroups: gmane.emacs.devel Subject: Re: Compiled code in Emacs-26 will fail in Emacs-25 if use pcase Date: Tue, 11 Apr 2017 19:40:20 +0200 Organization: nocrew Message-ID: <864lxuyha3.fsf_-_@molnjunk.nocrew.org> References: <1b07c68a-873e-83c8-246d-423bc83a3881@gmail.com> <83y3xg4ldw.fsf@gnu.org> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1491932486 11873 195.159.176.226 (11 Apr 2017 17:41:26 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 11 Apr 2017 17:41:26 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Apr 11 19:41:21 2017 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 1cxzn6-0002ts-14 for ged-emacs-devel@m.gmane.org; Tue, 11 Apr 2017 19:41:20 +0200 Original-Received: from localhost ([::1]:40467 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxzn8-000058-2H for ged-emacs-devel@m.gmane.org; Tue, 11 Apr 2017 13:41:22 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:56538) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxzmO-0008WE-C6 for emacs-devel@gnu.org; Tue, 11 Apr 2017 13:40:37 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cxzmJ-0003nn-Dh for emacs-devel@gnu.org; Tue, 11 Apr 2017 13:40:36 -0400 Original-Received: from [195.159.176.226] (port=54488 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cxzmJ-0003ne-7H for emacs-devel@gnu.org; Tue, 11 Apr 2017 13:40:31 -0400 Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1cxzm9-0001uI-Cd for emacs-devel@gnu.org; Tue, 11 Apr 2017 19:40:21 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 18 Original-X-Complaints-To: usenet@blaine.gmane.org Cancel-Lock: sha1:PEj20CCE82rOz5k5FMF9vYWvUS0= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 195.159.176.226 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:213878 Archived-At: Stefan Monnier wrote: >> I) Compile under master branch. >> II) Load the resultant .elc with Emacs-25 > > As explained by Richard, this is usually considered acceptable. > We don't really try to provide forward compatibility of byte-code files > between major versions. > > This said, occasionally we try to reduce the pain a little: e.g. in > Emacs-25 a similar incompatibility was introduced for the compilation of > catch&condition-case, but the bytecodes were introduced a bit earlier. > IOW the incompatibility was fundamentally introduced in 24.4 (IIRC), but > the use of the this new feature was only enabled in Emacs-25.1, so files > compiled with 25.1 will usually work in 24.5 as well. It this something that should be done with records too? E.g. add the new record functions to the emacs-25 branch, but not the changes to cl-defstruct and defclass.