From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1943 invoked by alias); 8 Nov 2004 23:57:42 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 1784 invoked from network); 8 Nov 2004 23:57:35 -0000 Received: from unknown (HELO bluesmobile.specifixinc.com) (64.220.152.98) by sourceware.org with SMTP; 8 Nov 2004 23:57:35 -0000 Received: from [127.0.0.1] (bluesmobile.corp.specifixinc.com [192.168.1.2]) by bluesmobile.specifixinc.com (Postfix) with ESMTP id CB198167EE; Mon, 8 Nov 2004 15:57:34 -0800 (PST) Subject: Re: Mixing 32-bit and 64-bit DWARF2/3 sections From: James E Wilson To: Thiemo Seufer Cc: Mark Kettenis , echristo@redhat.com, gdb@sources.redhat.com, gcc@gcc.gnu.org, binutils@sources.redhat.com In-Reply-To: <20041108233732.GH22577@rembrandt.csv.ica.uni-stuttgart.de> References: <200411071428.iA7ES7Fx003013@elgar.sibelius.xs4all.nl> <418FDD06.9030404@specifixinc.com> <200411082204.iA8M4jws088177@elgar.sibelius.xs4all.nl> <1099955006.7589.43.camel@aretha.corp.specifixinc.com> <20041108233732.GH22577@rembrandt.csv.ica.uni-stuttgart.de> Content-Type: text/plain Message-Id: <1099958254.7589.64.camel@aretha.corp.specifixinc.com> Mime-Version: 1.0 Date: Tue, 09 Nov 2004 00:15:00 -0000 Content-Transfer-Encoding: 7bit X-SW-Source: 2004-11/txt/msg00071.txt.bz2 On Mon, 2004-11-08 at 15:37, Thiemo Seufer wrote: > FWIW, I doubt going back unconditionally to a 32bit format is the right > thing to do for a fully 64bit ABI. Applications tend to grow further, > as does the accompanying debug info, so the 32bit limit comes closer. DWARF2 debug info has a field to indicate pointer size, and uses this for addresses. The only limit to DWARF2 debug info is that cross references within the DWARF2 debug info are specified by 32-bit fields. Thus, in order to exceed the 32-bit limit, one of the DWARF2 sections must be larger than 4GB. Since the DWARF2 info is spread across multiple sections, it would be possible to have 36GB of DWARF2 debug info, and still not exceed the 32-bit limit, if none of the individual sections are larger than 4GB. You can have a 1TB application, and still not exceed the 32-bit limit, if none of the individual DWARF2 debug section are larger than 4GB. I don't think we should be worried about use of 32-bit DWARF2 debug info. We are unlikely to hit the limits anytime soon. And if we do hit the limits, then we will likely have other more serious problems. -- Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com