From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22575 invoked by alias); 15 Sep 2003 20:33:28 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 22568 invoked from network); 15 Sep 2003 20:33:28 -0000 Received: from unknown (HELO nevyn.them.org) (66.93.172.17) by sources.redhat.com with SMTP; 15 Sep 2003 20:33:28 -0000 Received: from drow by nevyn.them.org with local (Exim 4.22 #1 (Debian)) id 19z02J-0007Jm-JC for ; Mon, 15 Sep 2003 16:33:27 -0400 Date: Mon, 15 Sep 2003 20:33:00 -0000 From: Daniel Jacobowitz To: gdb-patches@sources.redhat.com Subject: Re: [libiberty and gdb] floatformat_is_valid Message-ID: <20030915203327.GA17285@nevyn.them.org> Mail-Followup-To: gdb-patches@sources.redhat.com References: <20030915143933.GA22129@nevyn.them.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030915143933.GA22129@nevyn.them.org> User-Agent: Mutt/1.5.1i X-SW-Source: 2003-09/txt/msg00337.txt.bz2 On Mon, Sep 15, 2003 at 10:39:33AM -0400, Daniel Jacobowitz wrote: > GDB's "struct value" has a union in it. This union, named "aligner", has a > long double member as well as several others; its goal is to be a cheap way > to ensure that we can load all sorts of values straight from the value > structure, without alignment problems. Unfortunately, this means that when > debugging GDB we tend to feed random bytes to printf ("%.35Lg"). That's not > kosher, and on i386 I've found a whole bunch of numbers which can crash it - > the gist is that GMP shifts normalized numbers over until it hits a one bit, > and if the explicit integer bit isn't set it walks right out of the number. > > This could show up in other places too. Anywhere you print floating-point > data from the inferior, really. > > So here's a patch which checks for the problem. I added > floatformat_is_valid to libiberty/floatformat.c. Is this OK? > [Do I need approval? Floatformat.c is in libiberty, but marked as part of > GDB.] > > Oh, this patch misses some copyright year updates. I'll get them before > checking in. Checked in. -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer