From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20290 invoked by alias); 2 Dec 2007 10:43:56 -0000 Received: (qmail 20278 invoked by uid 22791); 2 Dec 2007 10:43:55 -0000 X-Spam-Check-By: sourceware.org Received: from anyanka.rfc1149.net (HELO mail2.rfc1149.net) (81.56.47.149) by sourceware.org (qpsmtpd/0.31) with ESMTP; Sun, 02 Dec 2007 10:43:49 +0000 Received: from localhost (localhost [127.0.0.1]) by mail2.rfc1149.net (Postfix) with ESMTP id C0ED0C405C; Sun, 2 Dec 2007 11:43:44 +0100 (CET) Received: from mail2.rfc1149.net ([127.0.0.1]) by localhost (localhost [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id b2GLL17JiYBU; Sun, 2 Dec 2007 11:43:44 +0100 (CET) Received: by mail2.rfc1149.net (Postfix, from userid 1000) id 8E217C405E; Sun, 2 Dec 2007 11:43:44 +0100 (CET) Date: Sun, 02 Dec 2007 10:43:00 -0000 To: Eric Botcazou Cc: gcc@gcc.gnu.org Subject: Re: Rant about ChangeLog entries and commit messages References: <2007-12-02-11-05-39+trackit+sam@rfc1149.net> <200712021127.46198.ebotcazou@libertysurf.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <200712021127.46198.ebotcazou@libertysurf.fr> User-Agent: Mutt/1.5.17 (2007-11-01) From: Samuel Tardieu X-WWW: http://www.rfc1149.net/sam X-Jabber: (see http://www.jabber.org/) X-OpenPGP-Fingerprint: 79C0 AE3C CEA8 F17B 0EF1 45A5 F133 2241 1B80 ADE6 (see http://www.gnupg.org/) Message-Id: <2007-12-02-11-43-44+trackit+sam@rfc1149.net> 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: 2007-12/txt/msg00019.txt.bz2 On 2/12, Eric Botcazou wrote: | He indeed cannot, but the ChangeLog is not meant to make it possible either. | See http://gcc.gnu.org/contribute.html, especially the GNU Coding Standards. I know this document and I think the part on ChangeLog doesn't achieve its purpose: http://www.gnu.org/prep/standards/standards.html#Change-Logs Keep a change log to describe all the changes made to program source files. The purpose of this is so that people investigating bugs in the future will know about the changes that might have introduced the bug. Often a new bug can be found by looking at what was recently changed. More importantly, change logs can help you eliminate conceptual inconsistencies between different parts of a program, by giving you a history of how the conflicting concepts arose and who they came from. This is precisely why I am proposing an evolution in the current process. Also, this document states: There's no need to describe the full purpose of the changes or how they work together. If you think that a change calls for explanation, you're probably right. Please do explain it—but please put the explanation in comments in the code, where people will see it whenever they see the code. When you fix a bug by changing a constant (for example if there has been an offset by one error or, as I did a few minutes ago in config/sh/sh.md, there was an error in the argument to consider), this doesn't always mandate a comment in the code. For example, I think a description such as the one I wrote when describing the problem cmpgeusi_t splitting code compares operand 0 to 0, while this constant value can only be in operand 1. When compiling the Ada runtime, this leads to a "cmp/hs #0,r7" instruction which is not valid as "cmp/hs" operands must be two registers. along with the above change would have been a better commit message than just gcc/ * config/sh/sh.md (cmpgeusi_t): Fix condition. which I used as suggested. | That's how it has always worked so it should be more or less practical. Sure, it works. But this is not a reason not to improve the process. | For PRs, there is a link (URL: field), maybe we should use PRs more often. This field is useful to look at the discussion that led to the change, but PRs often contain no synthetic information on the analysis of the problem unless when the PR submitter sends a patch himself (in which case he often includes his analysis to get a better chance to get his patch checked in).