From owner-freebsd-hackers Sun Aug 4 2:42: 3 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D057637B400 for ; Sun, 4 Aug 2002 02:41:59 -0700 (PDT) Received: from mailf.telia.com (mailf.telia.com [194.22.194.25]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8263143E4A for ; Sun, 4 Aug 2002 02:41:57 -0700 (PDT) (envelope-from erikt@midgard.homeip.net) Received: from d1o913.telia.com (d1o913.telia.com [195.252.44.241]) by mailf.telia.com (8.12.5/8.12.5) with ESMTP id g749ftMu021080 for ; Sun, 4 Aug 2002 11:41:56 +0200 (CEST) X-Original-Recipient: Received: from falcon.midgard.homeip.net (h62n2fls20o913.telia.com [212.181.163.62]) by d1o913.telia.com (8.8.8/8.8.8) with SMTP id LAA04313 for ; Sun, 4 Aug 2002 11:41:53 +0200 (CEST) Received: (qmail 99038 invoked by uid 1001); 4 Aug 2002 09:41:51 -0000 Date: Sun, 4 Aug 2002 11:41:50 +0200 From: Erik Trulsson To: Darren Pilgrim Cc: Terry Lambert , Dmitry Morozovsky , hackers@freebsd.org Subject: Re: -fomit-frame-pointer for the world build Message-ID: <20020804094150.GA96739@falcon.midgard.homeip.net> Mail-Followup-To: Darren Pilgrim , Terry Lambert , Dmitry Morozovsky , hackers@freebsd.org References: <20020802212841.R58905-100000@woozle.rinet.ru> <3D4AC526.4CD399B3@mindspring.com> <3D4C8464.A2F4775A@pantherdragon.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3D4C8464.A2F4775A@pantherdragon.org> User-Agent: Mutt/1.5.1i Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Sat, Aug 03, 2002 at 06:33:24PM -0700, Darren Pilgrim wrote: > Terry Lambert wrote: > > Dmitry Morozovsky wrote: > > > What are the drawbacks of building FreeBSD with -fomit-frame-pointer? > > > > The frame pointer is used for debugging, specifically for the > > stack traceback function to know arguments. Removing it means > > losing some debugging functionality. Next time try "info gcc": > > If you don't have any need for debugging your software, is there any > use for frame pointers? Is this something that can safely be used for > both CFLAGS and COPTFLAGS? I would say be careful. I used to use -fomit-frame-pointer but I decided to stop. For one thing I didn't really notice any speedup. More importantly I ran one port that did not compile correctly with -fomit-frame-pointer. I don't quite remember which port but I think it was Mozilla, or possibly some other program using moderately complex C++. Anyway, with -fomit-frame-pointer the build consistently failed at exactly the same place. Without -fomit-frame-pointer it built just fine. Now this might well be a bug in that port, or it might be that some feature of C++ (exception handling would be my first guess) uses the frame pointer. This was some time ago so the problem, whatever it was, might well be fixed by now, but just bear this in mind if you decide to use -fomit-frame-pointer -- Erik Trulsson ertr1013@student.uu.se To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message