From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1812 invoked by alias); 26 Nov 2009 19:38:13 -0000 Received: (qmail 1801 invoked by uid 22791); 26 Nov 2009 19:38:13 -0000 X-SWARE-Spam-Status: No, hits=-2.6 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from smtp-noauth7.primus.ca (HELO mail-01.primus.ca) (216.254.180.38) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 26 Nov 2009 19:38:04 +0000 Received: from [206.191.44.11] (helo=bambi.pccyber.com) by mail-01.primus.ca with esmtp (Exim 4.69) (envelope-from ) id 1NDkAD-0001zJ-37; Thu, 26 Nov 2009 14:38:02 -0500 Received: from localhost (localhost.localdomain [127.0.0.1]) by bambi.pccyber.com (Postfix) with ESMTP id B9D1B1B49C1; Thu, 26 Nov 2009 14:38:00 -0500 (EST) Received: from bambi.pccyber.com ([127.0.0.1]) by localhost (bambi.pccyber.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rDfBbr6LVYEv; Thu, 26 Nov 2009 14:38:00 -0500 (EST) Received: from [173.35.103.0] (CPE0050fca9b0e1-CM0018c0d3a5ba.cpe.net.cable.rogers.com [173.35.103.0]) (Authenticated sender: mark@pccyber.com) by bambi.pccyber.com (Postfix) with ESMTPA id BE7CD1B4985; Thu, 26 Nov 2009 14:37:59 -0500 (EST) Message-ID: <4B0ED8F8.7090607@mark.mielke.cc> Date: Thu, 26 Nov 2009 19:38:00 -0000 From: Mark Mielke User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.4pre) Gecko/20090922 Fedora/3.0-3.9.b4.fc12 Thunderbird/3.0b4 MIME-Version: 1.0 To: Michael Matz CC: Basile STARYNKEVITCH , Jeff Law , Richard Guenther , Dave Korn , "Joseph S. Myers" , Richard Kenner , gcc@gcc.gnu.org, hongjiu.lu@intel.com Subject: Re: trivial trailing whitespace issue References: <10911251651.AA00241@vlsi1.ultra.nyu.edu> <4B0D6245.3010601@redhat.com> <4B0D6708.7060306@redhat.com> <4B0D6DE6.4010708@gmail.com> <4B0D8C4B.9020405@redhat.com> <4B0D8ED5.1060303@starynkevitch.net> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org X-SW-Source: 2009-11/txt/msg00756.txt.bz2 On 11/26/2009 08:18 AM, Michael Matz wrote: > How, for goodness sake, can pure trailing whitespace changes, which by > necessity you can't even _see_ in an editor (except if you activate modes > that explicitely show them e.g. in different color) clean up code? Have > you looked at the patch or fallout from it? If not, why do you speak in > favor of it? I'm an outside observer with professional ties to SCM. This issue is similar in scope to TAB vs SPACE for indenting. Whether you can see it or not is not indicative of whether it has downstream effects or not. Generally, whitespace on the end of lines is bad, and cleanup eventually becomes necessary. It is "bad" because people will accidentally change lines without realizing them, and these changed lines show up in patches and annotations. This goes both ways - a lot of people browse code in vi, and accidentally add space to the end of lines they don't even intend to change. Or, maybe their editor automatically strips whitespace at end of line when they re-indent. Who knows? Same happens with TAB changed to SPACE or back and forth. Once these start to accumulate - they create downstream consequences that multiply. You can't see it, but every program that the file passes through *does* see them. Is cleanup in bulk the right approach? You either clean up over time or you do it in bulk. In my own projects, some of the designers I worked with had horrible habits in this regard. Every second line would have whitespace on the end. The longer it is left, the worse the effect. As software architect for our project, I notified the team I was doing a cleanup, and did it in bulk. Due to the notification, everything went smooth. It sounds like the idea should have been proposed and accepted. Everybody would have been ready for it, and nobody would be upset. Oh well. It's been entertaining. gcc@gcc.gnu.org is normally pretty dull to read... :-) Cheers, mark -- Mark Mielke