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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id D67A03858402 for ; Thu, 28 Oct 2021 06:52:10 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org D67A03858402 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-185-XlOKWnVZPECb_qi7rLwxug-1; Thu, 28 Oct 2021 02:52:07 -0400 X-MC-Unique: XlOKWnVZPECb_qi7rLwxug-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 218959F92A; Thu, 28 Oct 2021 06:52:05 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.194.250]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D45205C1C5; Thu, 28 Oct 2021 06:52:02 +0000 (UTC) From: Florian Weimer To: "H.J. Lu via llvm-dev" Cc: GNU C Library , binutils@sourceware.org, "H.J. Lu" , gcc@gcc.gnu.org, gnu-gabi@sourceware.org Subject: Re: [llvm-dev] [PATCH] Add GNU_PROPERTY_1_GLIBC_2_NEEDED References: Date: Thu, 28 Oct 2021 08:52:00 +0200 In-Reply-To: (H. J. Lu via llvm-dev's message of "Wed, 27 Oct 2021 17:03:45 -0700") Message-ID: <87zgqtljzj.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-4.0 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_NONE, TXREP autolearn=unavailable autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gnu-gabi@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gnu-gabi mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Oct 2021 06:52:12 -0000 * H. J. Lu via llvm-dev: > 1. Some binaries which require new ELF features, like DT_RELR, only > work with the new glibc binary. They crash at run-time with the older > glibc binaries. > 2. Somes binaries compiled with the new language features, like C2X > printf specifiers, only generate correct results with the new glibc > binary. Since we don't add new glibc versions to the printf function > family, they generate incorrect results at run-time with the older > glibc binaries. Solaris uses SHT_SUNW_verneed sections for this, not a property note. Property notes seem the wrong approach for this. And there is no reason to make this specific to glibc. However, I still very much dislike this proposal. Thanks, Florian