From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11427 invoked by alias); 15 Jun 2010 19:46:04 -0000 Mailing-List: contact archer-help@sourceware.org; run by ezmlm Sender: Precedence: bulk List-Post: List-Help: List-Subscribe: List-Id: Received: (qmail 11418 invoked by uid 22791); 15 Jun 2010 19:46:03 -0000 X-SWARE-Spam-Status: No, hits=-5.8 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,TW_BJ,TW_JC,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org From: Tom Tromey To: Roland McGrath Cc: Project Archer , Jakub Jelinek Subject: Re: Fedora 14 debug proposal References: <20100613104010.6D1174077C@magilla.sf.frob.com> Reply-To: Tom Tromey Date: Tue, 15 Jun 2010 19:46:00 -0000 In-Reply-To: <20100613104010.6D1174077C@magilla.sf.frob.com> (Roland McGrath's message of "Sun, 13 Jun 2010 03:40:10 -0700 (PDT)") 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-SW-Source: 2010-q2/txt/msg00052.txt.bz2 >>>>> "Roland" == Roland McGrath writes: Roland> For Fedora purposes, dropping .debug_pub* sections could just as Roland> well be done in the stripping stage. And, I don't think they Roland> really cost much space in the grand scheme of things. So there Roland> is little real motivation to fiddle gcc at all until after we Roland> have completed basically everything else in the related realms. Doing it in gcc can save some space, by not putting useless stuff into the string table. I didn't try to measure this. Just stripping the sections does not save much space, as you hypothesized; I did a test with objcopy on all the debuginfo I have currently installed (OO.o plus other random bits): opsy. du -s debug stripped 1883432 debug 1812156 stripped 71276 savings The indices are about 3x the size of the savings: opsy. du -s Out 208876 Out Tom> 3. If we are shipping GCC 4.5 in F14, I think we should enable the Tom> .debug_types stuff by default. This will shrink debuginfo and it Tom> makes gdb use less memory. Roland> libdw does not yet handle .debug_types. It of course will, but Roland> I wouldn't like to have a gcc defaults change on any queue until Roland> we are quite concrete with getting all the support in line. Yeah, that would be good for us too; some of the recent gcc changes caught us by surprise. OTOH I don't want to stop Jakub's gusto, maybe just get a little more warning of coming gdb-impacting changes. Tom> This one is optional, in particular I assume it will be subsumed by Tom> the other DWARF compression work. Roland> It should be, yes. I don't see any reason that .debug_types and Roland> DW_FORM_ref_sig8 need to survive final linking. The normal reference Roland> forms are more efficient for consumers to use. Why is that? I looked at the gdb code here and nothing really stood out. Tom