From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1570 invoked by alias); 10 Jan 2008 21:52:15 -0000 Received: (qmail 1559 invoked by uid 22791); 10 Jan 2008 21:52:14 -0000 X-Spam-Check-By: sourceware.org Received: from bluesmobile.specifix.com (HELO bluesmobile.specifix.com) (216.129.118.140) by sourceware.org (qpsmtpd/0.31) with ESMTP; Thu, 10 Jan 2008 21:51:38 +0000 Received: from [127.0.0.1] (bluesmobile.specifix.com [216.129.118.140]) by bluesmobile.specifix.com (Postfix) with ESMTP id 251833C0AE; Thu, 10 Jan 2008 13:51:36 -0800 (PST) Subject: Re: [RFA] Add option to skip prologue in "break FILE:LINENO" (take 2) From: Michael Snyder To: Jim Blandy Cc: Joel Brobecker , gdb-patches@sourceware.org In-Reply-To: References: <20080110151312.GC13181@adacore.com> Content-Type: text/plain Date: Thu, 10 Jan 2008 21:52:00 -0000 Message-Id: <1200001895.14654.33.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.10.3 (2.10.3-4.fc7) Content-Transfer-Encoding: 7bit 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/msg00249.txt.bz2 On Thu, 2008-01-10 at 09:24 -0800, Jim Blandy wrote: > 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. You're right -- initializations are treated as part of the function body, not the prologue. My concerns were largely unfounded. ;-)