From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by sourceware.org (Postfix) with ESMTPS id 00A7C3858D3C for ; Thu, 16 Sep 2021 07:41:41 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 00A7C3858D3C Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id A1AA21FEAA; Thu, 16 Sep 2021 07:41:40 +0000 (UTC) Received: from murzim.suse.de (murzim.suse.de [10.160.4.192]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 9676AA3B8F; Thu, 16 Sep 2021 07:41:40 +0000 (UTC) Date: Thu, 16 Sep 2021 09:41:40 +0200 (CEST) From: Richard Biener To: "Koning, Paul" cc: GCC Patches , Andreas Schwab , "jeffreyalaw@gmail.com" , "dave.anglin@bell.net" , "ni1d@arrl.net" Subject: Re: [PATCH][v2] Always default to DWARF2_DEBUG if not specified, warn about deprecated STABS In-Reply-To: <972408A3-FB40-4312-8708-1C818497CE99@dell.com> Message-ID: <1917qo39-689-257q-738p-59r817o42ps1@fhfr.qr> References: <66161527-98n2-3060-49ss-67oro67381nq@fhfr.qr> <972408A3-FB40-4312-8708-1C818497CE99@dell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Spam-Status: No, score=-4.9 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 16 Sep 2021 07:41:43 -0000 On Wed, 15 Sep 2021, Koning, Paul wrote: > > > > On Sep 13, 2021, at 3:31 AM, Richard Biener wrote: > > > > This makes defaults.h choose DWARF2_DEBUG if PREFERRED_DEBUGGING_TYPE > > is not specified by the target and NO_DEBUG if DWARF is not supported. > > As I'm looking at questions about old debug formats, it brings up the > question of old object formats. I don't remember what the status of > a.out is. Is that considered deprecated? Still current? Of course > most targets use elf, but is there an expectation to move away from > a.out the way there is an expectation to move away from STABS? > > Is this actually a binutils rather than a gcc question? I guess it's a question for both - I do still see a.out targets in the configs supported by gas for example. Note that languages like C++ might have difficulties with object formats that do not support separate sections for instantiated templates for example, or for global initializers. We might have kludges for that in collect2 where removing those might be a motivation to deprecate object formats not supporting some set of features (named sections for example). As for "old", the problem with the legacy systems, being it pdp11 or hppa-hpux, is of course that they tend to be kept alive with minimal resources and doing major modernization doesn't really make sense if all that is wanted is to preserve them rather than turning them into something modern. That said - yes, I'd consider a.out purely legacy and not fit for the future. But it never came up on the radar of standing in the way of modernizing GCC in any area. Richard.