From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 128400 invoked by alias); 9 Jan 2019 04:12:08 -0000 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 Received: (qmail 128266 invoked by uid 89); 9 Jan 2019 04:11:55 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 spammy=equally, nightmare, Hx-languages-length:1429, our X-HELO: smtp.polymtl.ca Received: from smtp.polymtl.ca (HELO smtp.polymtl.ca) (132.207.4.11) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 09 Jan 2019 04:11:54 +0000 Received: from simark.ca (simark.ca [158.69.221.121]) (authenticated bits=0) by smtp.polymtl.ca (8.14.7/8.14.7) with ESMTP id x094BlC2029781 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 8 Jan 2019 23:11:52 -0500 Received: by simark.ca (Postfix, from userid 112) id B4CC11E7B7; Tue, 8 Jan 2019 23:11:47 -0500 (EST) Received: from simark.ca (localhost [127.0.0.1]) by simark.ca (Postfix) with ESMTP id 103091E52D; Tue, 8 Jan 2019 23:11:46 -0500 (EST) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 09 Jan 2019 04:12:00 -0000 From: Simon Marchi To: Eli Zaretskii Cc: Simon Marchi , gdb-patches@sourceware.org Subject: Re: [PATCH] gdb: Remove support for old mangling schemes In-Reply-To: <83lg3uijqd.fsf@gnu.org> References: <20190108232208.17487-1-simon.marchi@ericsson.com> <83lg3uijqd.fsf@gnu.org> Message-ID: <07d8a0b070a8add802ae30ab37a780db@polymtl.ca> X-Sender: simon.marchi@polymtl.ca User-Agent: Roundcube Webmail/1.3.6 X-IsSubscribed: yes X-SW-Source: 2019-01/txt/msg00174.txt.bz2 On 2019-01-08 22:38, Eli Zaretskii wrote: >> From: Simon Marchi >> CC: Simon Marchi >> Date: Tue, 8 Jan 2019 23:22:22 +0000 >> >> An upcoming sync with gcc's libiberty [1] will remove support for old >> mangling schemes (GNU v2, Lucid, ARM, HP and EDG). It will remove the >> cplus_demangle_opname function, so we need to get rid of its usages in >> GDB (it's a GNU v2 specific function). > > This would mean new GDB releases will not be able to debug old > programs, is that right? If so, perhaps we should instead keep our > local version of the relative functions, so that GDB will not regress > in that way. Our considerations in this matter are different from > those of GCC. We're talking about really old programs here. IIUC, the GNU v2 mangling was used in the GCC 2.95 era, which is around 2002. I think it's fine to drop support for this. If you had a system from that era, you would have a hard time compiling today's GDB on it. And even if you just had an old binary on a recent systems, well the older GDB releases are always available. I don't think it's worth our time to keep compatibility with that. Just testing it would probably be a nightmare. I don't know much about the other mangling schemes, but I assume they are equally ancient. Maybe somebody else can give more info about them. Simon