From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30799 invoked by alias); 10 Jan 2008 17:25:10 -0000 Received: (qmail 30788 invoked by uid 22791); 10 Jan 2008 17:25:09 -0000 X-Spam-Check-By: sourceware.org Received: from mail.codesourcery.com (HELO mail.codesourcery.com) (65.74.133.4) by sourceware.org (qpsmtpd/0.31) with ESMTP; Thu, 10 Jan 2008 17:24:36 +0000 Received: (qmail 3328 invoked from network); 10 Jan 2008 17:24:34 -0000 Received: from unknown (HELO localhost) (jimb@127.0.0.2) by mail.codesourcery.com with ESMTPA; 10 Jan 2008 17:24:34 -0000 To: Joel Brobecker Cc: gdb-patches@sourceware.org Subject: Re: [RFA] Add option to skip prologue in "break FILE:LINENO" (take 2) References: <20080110151312.GC13181@adacore.com> From: Jim Blandy Date: Thu, 10 Jan 2008 17:25:00 -0000 In-Reply-To: <20080110151312.GC13181@adacore.com> (Joel Brobecker's message of "Thu, 10 Jan 2008 07:13:12 -0800") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-IsSubscribed: yes 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 X-SW-Source: 2008-01/txt/msg00243.txt.bz2 Joel Brobecker writes: > Following a request for comments regarding a proposed change of behavior > when inserting a breakpoint on a specific line number, we received a > variety of comments, and it appears very clearly that the proposal > was at the very least controversial. > > So, here is a new proposal where the existing behavior is preserved. > A new set/show command is introduced to allow the user to configure > GDB to activate the new proposed behavior: > > (gdb) set/show breakpoint skip-prologue > > The help text for this command explains the purpose of this option: > > Set the debugger behavior when inserting a breakpoint on a specific line. > When inserting a breakpoint on a specific line number that corresponds > to the prologue of a function, the debugger will automatically adjust > its location to the first line past the prologue if this option is set. > > By default, this option is OFF, preserving the current behavior. > I think this should take care of all the objections I read so far. Some of Michael's objections I didn't understand at all --- he seemed to believe that the change would affect GDB's behavior in ways I think it won't. I don't think your change would affect the usage that was most important to him. I'd like to get that (or perhaps just me) straightened out before we add an option. Options of this sort are effective at resolving contentious mailing list threads, but not very effective for the vast majority of users. Most users have little or no interest in GDB for its own sake, and won't look for options like 'set breakpoint skip-prologue', so subtle improvements that are disabled by default have almost no impact.