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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 D3C69C43334 for ; Thu, 6 Sep 2018 15:02:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 976C62075E for ; Thu, 6 Sep 2018 15:02:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 976C62075E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730165AbeIFTiC (ORCPT ); Thu, 6 Sep 2018 15:38:02 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:45692 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725819AbeIFTiC (ORCPT ); Thu, 6 Sep 2018 15:38:02 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 98649412CA60; Thu, 6 Sep 2018 15:02:05 +0000 (UTC) Received: from redhat.com (ovpn-120-232.rdu2.redhat.com [10.10.120.232]) by smtp.corp.redhat.com (Postfix) with SMTP id 3813C2166B41; Thu, 6 Sep 2018 15:02:05 +0000 (UTC) Date: Thu, 6 Sep 2018 11:02:04 -0400 From: "Michael S. Tsirkin" To: David Howells Cc: linux-api@vger.kernel.org, linux-kbuild@vger.kernel.org, Jason Wang , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 03/11] UAPI: virtio_net: Fix use of C++ keywords as structural members [ver #2] Message-ID: <20180906104208-mutt-send-email-mst@kernel.org> References: <153622549721.14298.8116794954073122489.stgit@warthog.procyon.org.uk> <153622552270.14298.14568295161017777604.stgit@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <153622552270.14298.14568295161017777604.stgit@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Thu, 06 Sep 2018 15:02:05 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Thu, 06 Sep 2018 15:02:05 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'mst@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 06, 2018 at 10:18:42AM +0100, David Howells wrote: > The virtio_net_ctrl_hdr struct uses a C++ keyword as structural members. Fix > this by inserting an anonymous union that provides an alternative name and > then hide the reserved name in C++. > > Signed-off-by: David Howells > cc: "Michael S. Tsirkin" > cc: Jason Wang > cc: virtualization@lists.linux-foundation.org > --- > > include/uapi/linux/virtio_net.h | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h > index a3715a3224c1..967142bc0e05 100644 > --- a/include/uapi/linux/virtio_net.h > +++ b/include/uapi/linux/virtio_net.h > @@ -150,7 +150,12 @@ struct virtio_net_hdr_mrg_rxbuf { > * command goes in between. > */ > struct virtio_net_ctrl_hdr { > - __u8 class; > + union { > +#ifndef __cplusplus > + __u8 class; > +#endif > + __u8 _class; > + }; > __u8 cmd; > } __attribute__((packed)); > So if we are going to do this, I think I'd prefer something like: struct virtio_net_ctrl_hdr_v2 { __u8 cmd_class; __u8 cmd; }; And then hide the whole old structure. This also gets rid of the packed keyword which we don't really need here. Only issue is virtio_net_ctrl_hdr_v2 is ugly. But oh well. And then rework at least QEMU to use the v2 of the header. Quite a bit of churn, so I don't think it makes sense to apply just this one in isolation - only if rest of the changes go in. -- MST