From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15498 invoked by alias); 21 Jul 2011 15:52:28 -0000 Received: (qmail 15480 invoked by uid 22791); 21 Jul 2011 15:52:27 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,RP_MATCHES_RCVD,SPF_HELO_PASS X-Spam-Check-By: sourceware.org Received: from smtp-out.google.com (HELO smtp-out.google.com) (74.125.121.67) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 21 Jul 2011 15:51:54 +0000 Received: from hpaq11.eem.corp.google.com (hpaq11.eem.corp.google.com [172.25.149.11]) by smtp-out.google.com with ESMTP id p6LFprMZ031183 for ; Thu, 21 Jul 2011 08:51:53 -0700 Received: from iwg8 (iwg8.prod.google.com [10.241.66.136]) by hpaq11.eem.corp.google.com with ESMTP id p6LFpalM032155 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for ; Thu, 21 Jul 2011 08:51:51 -0700 Received: by iwg8 with SMTP id 8so1237685iwg.24 for ; Thu, 21 Jul 2011 08:51:51 -0700 (PDT) Received: by 10.231.159.133 with SMTP id j5mr320400ibx.98.1311263509817; Thu, 21 Jul 2011 08:51:49 -0700 (PDT) Received: from coign.google.com ([216.239.45.130]) by mx.google.com with ESMTPS id k16sm2001759icc.22.2011.07.21.08.51.47 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 21 Jul 2011 08:51:48 -0700 (PDT) From: Ian Lance Taylor To: Basile Starynkevitch 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++ References: <4E26E775.7070802@moene.org> <20110721092510.86ade74ddfe5b88d32e68876@starynkevitch.net> Date: Thu, 21 Jul 2011 16:06:00 -0000 In-Reply-To: <20110721092510.86ade74ddfe5b88d32e68876@starynkevitch.net> (Basile Starynkevitch's message of "Thu, 21 Jul 2011 09:25:10 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-System-Of-Record: true 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/msg00406.txt.bz2 Basile Starynkevitch writes: > 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. In practice I think it is fine to just pass the source file name to -frandom-seed. That's what the patch I sent out does. The source file name should be unique within a given program. Ian