From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22632 invoked by alias); 21 Jul 2011 07:25:59 -0000 Received: (qmail 22612 invoked by uid 22791); 21 Jul 2011 07:25:58 -0000 X-SWARE-Spam-Status: No, hits=-1.1 required=5.0 tests=AWL,BAYES_00,RDNS_DYNAMIC,TVD_RCVD_IP X-Spam-Check-By: sourceware.org Received: from 195-14-0-142.nuxit.net (HELO de558.ispfr.net) (195.14.0.142) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 21 Jul 2011 07:25:25 +0000 Received: from ours.starynkevitch.net ([213.41.244.95] helo=glinka.lesours) by de558.ispfr.net with smtp (Exim 4.72) (envelope-from ) id 1QjndI-0007vU-TL; Thu, 21 Jul 2011 09:25:21 +0200 Date: Thu, 21 Jul 2011 09:40:00 -0000 From: Basile Starynkevitch To: Ian Lance Taylor Cc: Mike Stump , David Edelsohn , gcc-patches@gcc.gnu.org, gcc@gcc.gnu.org Subject: Re: PATCH RFA: Build stages 2 and 3 with C++ Message-Id: <20110721092510.86ade74ddfe5b88d32e68876@starynkevitch.net> In-Reply-To: References: <4E26E775.7070802@moene.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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: 2011-07/txt/msg00401.txt.bz2 On Wed, 20 Jul 2011 14:41:16 -0700 Ian Lance Taylor wrote: > Mike Stump writes: > > >> Presumably the fix will be to use -frandom-seed. > > > > But, the random seem was to ensure that things that should not collide, don't. If you use 0, then things that should not collide, eventually will and your world with then end. In the present code base, it is perfectly safe to do this. If the codebase is ever extended to use C++ features, then, that code can break. > > I wasn't suggesting using -frandom-seed=0. I have a similar issue in the MELT branch, and I am passing to -frandom-seed the md5sum of relevant source files. With such a trick, the seed is reproducible from one build to the next one (of the exact same source tree), and does provide much more randomness than just using 0 all the time. Cheers. -- Basile STARYNKEVITCH http://starynkevitch.net/Basile/ email: basilestarynkevitchnet mobile: +33 6 8501 2359 8, rue de la Faiencerie, 92340 Bourg La Reine, France *** opinions {are only mine, sont seulement les miennes} ***