From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by sourceware.org (Postfix) with ESMTP id C5418384C005 for ; Wed, 17 Mar 2021 20:59:28 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org C5418384C005 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-334-B6vt1E5aO0GaKfdcSKNHTw-1; Wed, 17 Mar 2021 16:59:25 -0400 X-MC-Unique: B6vt1E5aO0GaKfdcSKNHTw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8E76A801982; Wed, 17 Mar 2021 20:59:23 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-115-121.ams2.redhat.com [10.36.115.121]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AC375610F0; Wed, 17 Mar 2021 20:59:22 +0000 (UTC) From: Florian Weimer To: libc-alpha@sourceware.org Cc: Joseph Myers Subject: Compat symbols in abilist files Date: Wed, 17 Mar 2021 21:59:28 +0100 Message-ID: <87eegdwl73.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-6.6 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Mar 2021 20:59:29 -0000 I'd like to re-raise the matter of comapt symbol markers in abilist files. --enable-obsolete-rpc (which changed compat symbol status) is gone, which should simplify matters. Joseph, you objected to this in the past. While reviewing libpthread symbol moves, I noticed that when going from libc: pread@@GLIBC_2.1 libpthread: pread@@GLIBC_2.2 to libc: pread@GLIBC_2.1 pread@@GLIBC_2.2 we would actually have to switch to libc: pread@GLIBC_2.1 pread@GLIBC_2.2 pread@@GLIBC_2.34 because a newly linked binary would produce a pread@@GLIBC_2.2 reference without linking to libpthread, which could result in a lazy binding failure at run time. If we swap around the roles of compat symbols, like this libc: pread@@GLIBC_2.1 pread@GLIBC_2.2 the new symbol version is not necessary. Unfortunately this is currently not visible at all in the abilist files. The versioned_symbol/compat_symbol constructs are also quite hard to review. So I'm worried that we don't get the link-time ABI we want on all targets. Thanks, Florian