From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11966 invoked by alias); 7 Nov 2007 23:05:56 -0000 Received: (qmail 11946 invoked by uid 22791); 7 Nov 2007 23:05:53 -0000 X-Spam-Check-By: sourceware.org Received: from NaN.false.org (HELO nan.false.org) (208.75.86.248) by sourceware.org (qpsmtpd/0.31) with ESMTP; Wed, 07 Nov 2007 23:05:50 +0000 Received: from nan.false.org (localhost [127.0.0.1]) by nan.false.org (Postfix) with ESMTP id 33B0298354; Wed, 7 Nov 2007 23:05:49 +0000 (GMT) Received: from caradoc.them.org (22.svnf5.xdsl.nauticom.net [209.195.183.55]) by nan.false.org (Postfix) with ESMTP id EA1D49833F; Wed, 7 Nov 2007 23:05:48 +0000 (GMT) Received: from drow by caradoc.them.org with local (Exim 4.68) (envelope-from ) id 1Ipty0-0000tE-6i; Wed, 07 Nov 2007 18:05:48 -0500 Date: Wed, 07 Nov 2007 23:28:00 -0000 From: Daniel Jacobowitz To: Ian Lance Taylor Cc: Alexandre Oliva , Richard Guenther , gcc-patches@gcc.gnu.org, gcc@gcc.gnu.org Subject: Re: Designs for better debug info in GCC Message-ID: <20071107230548.GA2998@caradoc.them.org> Mail-Followup-To: Ian Lance Taylor , Alexandre Oliva , Richard Guenther , gcc-patches@gcc.gnu.org, gcc@gcc.gnu.org References: <84fc9c000711050327x74845c78ya18a3329fcf9e4d2@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.15 (2007-04-09) 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: 2007-11/txt/msg00217.txt.bz2 On Wed, Nov 07, 2007 at 02:56:24PM -0800, Ian Lance Taylor wrote: > At one time, gcc actually provided better debugging of optimized code > than any other compiler, though I don't know if that is still true. > Optimized gcc code is still debuggable today. I do it all the time. > (For me poor support for debugging C++ is a much bigger issue, though > I think that is an issue more with gdb than with gcc.) We're working on both of these on the GDB side. > gcc's users are definitely calling for a faster compiler. Are they > calling for better debuggability of optimized code? In my experience, yes. CodeSourcery has work currently being contributed to GDB that makes this quite a lot better; we also occasionally have customers ask us about further improvements. And I file bugs about this from time to time, most of which are still open. > As I understand your proposal, it materializes variables which were > otherwise omitted from the generated program. It doesn't address the > other issues with debugging optimized code, like bouncing around > between program lines. Is that correct? What else does your proposal > do? I've been thinking about the bouncing problem quite a bit lately. I have some rough ideas, but I won't draw out this thread by sharing :-) -- Daniel Jacobowitz CodeSourcery