From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30225 invoked by alias); 2 Dec 2009 19:39:05 -0000 Mailing-List: contact archer-help@sourceware.org; run by ezmlm Sender: Precedence: bulk List-Post: List-Help: List-Subscribe: List-Id: Received: (qmail 30191 invoked by uid 22791); 2 Dec 2009 19:39:04 -0000 X-SWARE-Spam-Status: No, hits=-2.5 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Date: Wed, 02 Dec 2009 19:39:00 -0000 From: Daniel Jacobowitz To: Tom Tromey Cc: Cary Coutant , Dodji Seketeli , GDB/Archer list Subject: Re: [RFC] Proposal for a new DWARF name index section Message-ID: <20091202193852.GA23631@caradoc.them.org> References: <4A7FE28D.4050901@redhat.com> <4A8D8868.3010302@redhat.com> <20091202051717.GA24978@caradoc.them.org> <20091202173518.GA13838@caradoc.them.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) X-SW-Source: 2009-q4/txt/msg00075.txt.bz2 On Wed, Dec 02, 2009 at 12:23:25PM -0700, Tom Tromey wrote: > I do think that slowing down the compiler to speed up the debugger would > be the wrong tradeoff. I was hoping we could get this for free in the > compiler, or nearly so, but now I unfortunately see that I was confused > on that point :-(. We could pick a representation close to what gcc > already emits -- but then that overly constrains gcc in the future. That's not an option, anyway; the stuff GCC emits is too vague in some cases (he says unsubstantiatedly). > Caching is interesting but it comes with other problems. We have to > manage the cache somehow. And, the cache would not be useful when an > object changes. So, I'd prefer a direct approach, if one can be made to > work. Well, inherent in the cache approach (IMO) is a system-provided cache; for installed libraries, the cache data could be added to a debuginfo file. Of course, that assumes GDB's format stays "relatively stable" across GDB updates. > warm cache cold cache > without canonicalization: ~0.5 sec 5 sec > gdb does canonicalization: ~1.7 sec 6 sec > gdb cvs head: ~2.4 sec 10 sec Not bad! -- Daniel Jacobowitz CodeSourcery