From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: /srv/bzr/emacs/emacs-24 r111251: * pre-crt0.c (data_start): Initialize to 1. Date: Tue, 12 Feb 2013 14:06:59 -0800 Message-ID: <511ABD03.1080109@cs.ucla.edu> References: NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1360706851 2184 80.91.229.3 (12 Feb 2013 22:07:31 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 12 Feb 2013 22:07:31 +0000 (UTC) Cc: Emacs developers To: Glenn Morris Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Feb 12 23:07:52 2013 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1U5O0w-0001dA-PV for ged-emacs-devel@m.gmane.org; Tue, 12 Feb 2013 23:07:46 +0100 Original-Received: from localhost ([::1]:37791 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1U5O0c-0001CK-Eo for ged-emacs-devel@m.gmane.org; Tue, 12 Feb 2013 17:07:26 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:37694) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1U5O0X-0001BL-Ak for emacs-devel@gnu.org; Tue, 12 Feb 2013 17:07:25 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1U5O0G-0002WU-Oj for emacs-devel@gnu.org; Tue, 12 Feb 2013 17:07:07 -0500 Original-Received: from smtp.cs.ucla.edu ([131.179.128.62]:44972) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1U5O0G-0002WE-GC; Tue, 12 Feb 2013 17:07:04 -0500 Original-Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp.cs.ucla.edu (Postfix) with ESMTP id 0A65439E8105; Tue, 12 Feb 2013 14:07:03 -0800 (PST) X-Virus-Scanned: amavisd-new at smtp.cs.ucla.edu Original-Received: from smtp.cs.ucla.edu ([127.0.0.1]) by localhost (smtp.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vKW8qZypJtsJ; Tue, 12 Feb 2013 14:07:00 -0800 (PST) Original-Received: from penguin.cs.ucla.edu (Penguin.CS.UCLA.EDU [131.179.64.200]) by smtp.cs.ucla.edu (Postfix) with ESMTPSA id 7CE8A39E8100; Tue, 12 Feb 2013 14:07:00 -0800 (PST) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 In-Reply-To: X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 131.179.128.62 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 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-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:156988 Archived-At: On 02/12/13 13:07, Glenn Morris wrote: > the code is used by other, working platforms. Can you please give an example of such a platform? I tried to find an example but came up dry (please see below). > Why is this change safe/necessary for emacs-24 at this late stage? The change is clearly safe as the variable's contents are never used. That being said, the change is not needed on a platform that defines BSD_SYSTEM or DATA_START or ORDINARY_LINK or CANNOT_DUMP or SYSTEM_MALLOC, as these systems never use the address of the variable. I just now checked configure.ac etc. and it appears that the change is therefore not needed on aix, *bsd, cygwin, darwin, gnu, hpux*, irix6-5, ms-dos, ms-w32, sol2*, unixware. Is this the complete set of systems that Emacs ports to? If so, the change isn't needed and I'd like to revert it (though the variable should be removed in the trunk, as it's no longer used anywhere). If not, the change is needed if the variable is compiled with a newer GCC (or similar compiler) with enough optimizing options that Emacs puts the variable into bss. I originally made the change because aix4-2 defined ORDINARY_LINK but later AIX releases did not, which meant it appeared that the variable was used on post-4.2 AIX releases. However, with my change to unexaix.c today, the AIX port never uses the address of the variable, so the change currently is not needed on post-4.2 AIX releases after all. I didn't put 2 and 2 together to see this; sorry.