From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1703AC31E51 for ; Tue, 18 Jun 2019 12:16:02 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E02CA20873 for ; Tue, 18 Jun 2019 12:16:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E02CA20873 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56484 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hdD1s-0002it-V0 for qemu-devel@archiver.kernel.org; Tue, 18 Jun 2019 08:16:00 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56882) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hdD0a-0002H2-OL for qemu-devel@nongnu.org; Tue, 18 Jun 2019 08:14:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hdD0Z-0006wT-J5 for qemu-devel@nongnu.org; Tue, 18 Jun 2019 08:14:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54104) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hdD0Z-0006db-DC for qemu-devel@nongnu.org; Tue, 18 Jun 2019 08:14:39 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AF2C620264; Tue, 18 Jun 2019 12:14:13 +0000 (UTC) Received: from redhat.com (ovpn-112-51.ams2.redhat.com [10.36.112.51]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EDFD81001DCB; Tue, 18 Jun 2019 12:14:11 +0000 (UTC) Date: Tue, 18 Jun 2019 13:14:08 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Anthony PERARD Message-ID: <20190618121408.GM28525@redhat.com> References: <20190618112341.513-1-anthony.perard@citrix.com> <20190618112341.513-2-anthony.perard@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190618112341.513-2-anthony.perard@citrix.com> User-Agent: Mutt/1.11.4 (2019-03-13) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Tue, 18 Jun 2019 12:14:13 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH v2 1/4] xen: Fix build with public headers X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: xen-devel@lists.xenproject.org, Paul Durrant , Stefano Stabellini , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Jun 18, 2019 at 12:23:38PM +0100, Anthony PERARD wrote: > Following 37677d7db3 "Clean up a few header guard symbols", QEMU start > to fail to build: > > In file included from ~/xen/tools/../tools/include/xen/io/blkif.h:31:0, > from ~/xen/tools/qemu-xen-dir/hw/block/xen_blkif.h:5, > from ~/xen/tools/qemu-xen-dir/hw/block/xen-block.c:22: > ~/xen/tools/../tools/include/xen/io/ring.h:68:0: error: "__CONST_RING_SIZE" redefined [-Werror] > #define __CONST_RING_SIZE(_s, _sz) \ > > In file included from ~/xen/tools/qemu-xen-dir/hw/block/xen_blkif.h:4:0, > from ~/xen/tools/qemu-xen-dir/hw/block/xen-block.c:22: > ~/xen/tools/qemu-xen-dir/include/hw/xen/io/ring.h:66:0: note: this is the location of the previous definition > #define __CONST_RING_SIZE(_s, _sz) \ > > The issue is that some public xen headers have been imported (by > f65eadb639 "xen: import ring.h from xen") but not all. With the change > in the guards symbole, the ring.h header start to be imported twice. Ah, so the include/hw/xen/io/ring.h file in tree is a copy of /usr/include/xen/io/ring.h from xen-devel. Previously both these used "#ifndef __XEN_PUBLIC_IO_RING_H__". After the header guard cleanup in 37677d7db3, our local copy used a different header guard from the installed copy & thus we're not protected from dual inclusion. IMHO the right solutions here are either - Don't copy public Xen headers into our tree - Keep our Xen header copies identical to the originals Importing public headers and then changing them locally is the worst thing to do. With that in mind I think we should revert the part of commit 37677d7db3 that touched the imported Xen headers. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|