From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4559 invoked by alias); 21 May 2014 19:30:38 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 4548 invoked by uid 89); 21 May 2014 19:30:37 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.2 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 21 May 2014 19:30:35 +0000 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s4LJUVMr001768 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 21 May 2014 15:30:32 -0400 Received: from barimba (ovpn-113-182.phx2.redhat.com [10.3.113.182]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s4LJUUKt006785 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=NO); Wed, 21 May 2014 15:30:30 -0400 From: Tom Tromey To: Bruce Dawson Cc: "'Gerhard Gappmeier'" , "gdb-patches\@sourceware.org" Subject: Re: New feature "source-id" References: <7365721.BnaR1nHazz@lt-gergap> <1905500.YOUlx3S3mT@ws-gergap> <1395154991.27876.65.camel@bordewijk.wildebeest.org> <1825450.WDlHRVxHcI@ws-gergap> <2AC155A009400B4C8B05D518E4819AEF1A347F70@exchange10.valvesoftware.com> Date: Wed, 21 May 2014 19:30:00 -0000 In-Reply-To: <2AC155A009400B4C8B05D518E4819AEF1A347F70@exchange10.valvesoftware.com> (Bruce Dawson's message of "Tue, 18 Mar 2014 17:56:14 +0000") Message-ID: <874n0jhqui.fsf@fleche.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-SW-Source: 2014-05/txt/msg00510.txt.bz2 >>>>> "Bruce" == Bruce Dawson writes: Bruce> I understand that some Linux distributions already make source Bruce> packages for each package that they distribute, and this technique Bruce> offers some unique advantages. Bruce> However, this is orthogonal to the source-id proposal. Source-id's Bruce> offer different value that is complementary. Bruce> Our build system spits out dozens of builds a day. Some of these are Bruce> run by developers, others by testers, and others by customers. Any one Bruce> of them might crash. I might end up debugging (live debugging or a Bruce> core file) any one of these builds, perhaps weeks after it was Bruce> created. Because we have the source-id system set up I know that I can Bruce> walk up and down the stack and have the source files automatically Bruce> show up, with *zero* effort on my part. I don't' have to install Bruce> source packages, I can have multiple core files from multiple versions Bruce> loaded simultaneously. Only the source files that I need are Bruce> downloaded so it is *extremely* efficient. Retrieving the needed Bruce> source files is essentially instantaneous and requires zero developer Bruce> effort. I wonder if you considered an approach based on build-ids. You'd start with the existing build-id feature. Then when your build completes, you would record a build-id -> source-id mapping. Finally you would have a small fuse filesystem that looks up the build-id in the database and fetches the appropriate source tree from git. One benefit of this approach is that it requires nearly no changes in gdb. This avoids a lot of bikeshedding ;) I found a few git/fuse projects on github. If you considered this & rejected it, I'd be curious to know why. If it doesn't meet your needs then I probably misunderstood what you are going for. FWIW the SRPM-based approach we use at Red Hat is pretty good, but not truly great. It has a hack in the rewriting step and sometimes the source tree layout isn't preserved properly somehow. So something like the above may be more desirable overall. Tom