From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mta04.svc.cra.dublin.eircom.net (mta04.svc.cra.dublin.eircom.net [159.134.118.171]) by sourceware.org (Postfix) with SMTP id 0369D3858C39 for ; Thu, 7 Oct 2021 12:43:48 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 0369D3858C39 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=debian.org Authentication-Results: sourceware.org; spf=none smtp.mailfrom=debian.org Received: (qmail 35609 messnum 19139861 invoked from network[213.94.190.14/avas02.vendorsvc.cra.dublin.eircom.net]); 7 Oct 2021 12:43:48 -0000 Received: from avas02.vendorsvc.cra.dublin.eircom.net (HELO avas02) (213.94.190.14) by mta04.svc.cra.dublin.eircom.net (qp 35609) with SMTP; 7 Oct 2021 12:43:48 -0000 Received: from mail.sceal.ie ([83.70.207.66]) by Cloudmark Gateway with SMTP id YSkWmTyB0n0FJYSkWmbKrf; Thu, 07 Oct 2021 13:43:48 +0100 X-CNFS-Analysis: v=2.2 cv=M+U9E24s c=1 sm=1 tr=0 a=0Iw1gYdl+gX5BU/pizvEUA==:117 a=0Iw1gYdl+gX5BU/pizvEUA==:17 a=IkcTkHD0fZMA:10 a=8gfv0ekSlNoA:10 a=xNf9USuDAAAA:8 a=Ug2Xn3OAAAAA:8 a=-uGBhWOqduNlRZfohfQA:9 a=QEXdDO2ut3YA:10 a=SEwjQc04WA-l_NiBhQ7s:22 a=jup2QEcnA-U7-sUVP0FS:22 Received: from localhost (localhost [127.0.0.1]) by mail.sceal.ie (Postfix) with ESMTP id F11C5F0588B; Thu, 7 Oct 2021 13:43:47 +0100 (IST) Received: from mail.sceal.ie ([127.0.0.1]) by localhost (mail.sceal.ie [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id eHUbh3zV_v-0; Thu, 7 Oct 2021 13:43:47 +0100 (IST) Received: from [192.168.11.76] (arcturus.ichec.ie [193.1.243.3]) by mail.sceal.ie (Postfix) with ESMTPSA id C1A20F00457; Thu, 7 Oct 2021 13:43:47 +0100 (IST) Message-ID: <2b7ce26b-0340-c1d8-8079-64f0a1d46bcd@debian.org> Date: Thu, 7 Oct 2021 13:43:47 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:93.0) Gecko/20100101 Thunderbird/93.0 Subject: Re: libgfortran.so SONAME and powerpc64le-linux ABI changes Content-Language: en-US To: Jakub Jelinek , Andreas Schwab Cc: Thomas Koenig , Segher Boessenkool , gcc@gcc.gnu.org, Jonathan Wakely , fortran@gcc.gnu.org, Tobias Burnus References: <20211004100754.GL304296@tucnak> <20211004141410.GP304296@tucnak> <6d845542-536e-1a0f-70e9-d05eea98aae7@netcologne.de> <20211005215450.GC10333@gate.crashing.org> <90df1250-9b3f-4a55-bc67-e3e05e54f7ef@netcologne.de> <2ed0ad86-f19f-dd72-31cf-52acae3aab6a@debian.org> <87bl4188f6.fsf@igel.home> <20211007100112.GS304296@tucnak> From: Alastair McKinstry Organization: Debian In-Reply-To: <20211007100112.GS304296@tucnak> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CMAE-Envelope: MS4wfF+gpZpPDILQMe+SyMU/CY6rxSwW9GhbhzFFMVp82objT6vLv7O9uZougYgAH4QDHdxjBjOwsXgN0dcynKiQEudVoU6a0iOmcpOf6EkgfFhO/6EC8Zqs b5AxiWOWa/VVE65RTiF1hFGmVSSDd+Y2lStWrroE0JqcP3VXI5tNKBOhR9+MZoTi0Tg2JqDcAXHd6JhLajHZ7HVzSI9+clfgk/L3EMzB2tVbKjPQJsUPkuUL jDL/Wkiz2Vz+dciHUNAi7V104IPt7yblhmymUhBx/a5oFGLOPMAC3oj5CjpEUJzLKu1e7fpvnVRu3rWsXWzpR7j5hhnvvTdJ3C+6cqoX6mSg1D+vX04AKxxR Fj+9ZI4Wu+br7Ccrsp3UD7v3G2gA2HU6Eueq1ERd4+abwxWKryM= X-Spam-Status: No, score=0.6 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, KAM_LAZY_DOMAIN_SECURITY, NICE_REPLY_A, RCVD_IN_BARRACUDACENTRAL, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=no 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@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Oct 2021 12:43:51 -0000 On 07/10/2021 11:01, Jakub Jelinek wrote: > On Thu, Oct 07, 2021 at 11:56:45AM +0200, Andreas Schwab wrote: >> On Okt 07 2021, Alastair McKinstry wrote: >> >>> I strongly advise against this -- identical SONAMEs for the libraries on >>> all architectures is a key assumption on all Debian-based distributions >>> and designs >> Even glibc has differing sonames on some architectures. And libgcc_s, >> too. > Yeah, lib[cm].so.6 on most arches and lib[cm].so.6.1 on ia64 or alpha. > At least on Fedora I don't see a problem having libgfortran.so.5 on > most arches and libgfortran.so.6 on ppc64le. And then next year or two/3 > switch to libgfortran.so.7 everywhere. SOVERSION (Major release) (and hence SONAME) change tracking are key to tracking the task of rebuilds/porting when incompatible changes happen in libraries (see https://release.debian.org/transitions/ and https://wiki.debian.org/Teams/ReleaseTeam/Transitions for examples of the process). lib[cm] on ia64 and alpha work in that libc has not changed major version in many years, and neither ia64 or alpha are currently "release candidates" in Debian, which we need to keep rebuilds in sync. Even so, the exception handling needed for them is a wart seen across the distro dependency trees. To make upgrades work, we have policy that it's possible that two versions of a library with different SONAME can co-exist  on a users' system (package libgfortran5  "just" ships the libgfortran.so.5  file, libgfortran6 can co-exist with it), but a given source package only provides one of these library packages, and there is only one -dev package (eg libgfortran-dev pointing libgfortran.so -> libgfortan.so.6). A transition (eg gcc-11 to gcc-12 moving into the 'testing' staging distro) updates libgfortran-dev to point to 6, drops libgfortran5 from the Debian archive (but doesn't delete the package libgfortran5 from the users' computer) and we rebuild and transition simultaneously all packages that depend on libgfortran5. So if we introduce libgfortran6 for ppc64le (with potential ABI changes such as KIND) we rely on libgfortran5 disappearing for our transition scripts to work, and testing the transition process. We can special-case it just for one arch/package but its significant work and really painful. A simple soname/soversion transition across all archs is much preferred. > Jakub Alastair -- Alastair McKinstry, , , https://diaspora.sceal.ie/u/amckinstry Misentropy: doubting that the Universe is becoming more disordered.