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 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4A1E7CDB482 for ; Mon, 16 Oct 2023 16:50:06 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.617892.960985 (Exim 4.92) (envelope-from ) id 1qsQmv-0004KA-6M; Mon, 16 Oct 2023 16:49:53 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 617892.960985; Mon, 16 Oct 2023 16:49:53 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qsQmv-0004K3-3X; Mon, 16 Oct 2023 16:49:53 +0000 Received: by outflank-mailman (input) for mailman id 617892; Mon, 16 Oct 2023 16:49:51 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qsQmt-0004Ij-NO for xen-devel@lists.xenproject.org; Mon, 16 Oct 2023 16:49:51 +0000 Received: from support.bugseng.com (mail.bugseng.com [162.55.131.47]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 04dfed71-6c44-11ee-9b0e-b553b5be7939; Mon, 16 Oct 2023 18:49:49 +0200 (CEST) Received: from support.bugseng.com (support.bugseng.com [162.55.131.47]) by support.bugseng.com (Postfix) with ESMTPA id 917694EE0737; Mon, 16 Oct 2023 18:49:48 +0200 (CEST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 04dfed71-6c44-11ee-9b0e-b553b5be7939 MIME-Version: 1.0 Date: Mon, 16 Oct 2023 18:49:48 +0200 From: Nicola Vetrini To: Jan Beulich Cc: sstabellini@kernel.org, michal.orzel@amd.com, xenia.ragiadakou@amd.com, ayan.kumar.halder@amd.com, consulting@bugseng.com, andrew.cooper3@citrix.com, roger.pau@citrix.com, Simone Ballarin , Doug Goldstein , George Dunlap , Julien Grall , Wei Liu , xen-devel@lists.xenproject.org Subject: Re: [XEN PATCH][for-4.19 v2 1/1] xen: introduce a deviation for Rule 11.9 In-Reply-To: <7be93272-dc82-06e0-726d-030d33aee5e1@suse.com> References: <7be93272-dc82-06e0-726d-030d33aee5e1@suse.com> User-Agent: Roundcube Webmail/1.4.3 Message-ID: <66e27d108e856fcf69f78652daae6447@bugseng.com> X-Sender: nicola.vetrini@bugseng.com Organization: BUGSENG s.r.l. Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit On 16/10/2023 15:43, Jan Beulich wrote: > On 11.10.2023 14:46, Nicola Vetrini wrote: >> --- a/xen/include/xen/compiler.h >> +++ b/xen/include/xen/compiler.h >> @@ -109,13 +109,16 @@ >> >> #define offsetof(a,b) __builtin_offsetof(a,b) >> >> +/* Access the field of structure type, without defining a local >> variable */ >> +#define access_field(type, member) (((type *)NULL)->member) > > This is not a field access, so I consider the macro misnamed. Question > is > whether such a helper macro is needed in the first place. > >> +#define typeof_field(type, member) typeof(access_field(type, member)) > > If this needs adding, it wants to come ... > >> /** >> * sizeof_field(TYPE, MEMBER) >> * >> * @TYPE: The structure containing the field of interest >> * @MEMBER: The field to return the size of >> */ >> -#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER)) >> +#define sizeof_field(TYPE, MEMBER) sizeof(access_field(TYPE, MEMBER)) > > ... with a commend similar as this one has. (Or the commend could be > slightly altered to cover both). > I added access_field since it's possibly useful on its own in the future, but that may not be the case. Not a real field access, perhaps a fake_access_field? Ok about the missing comment for typeof_field. > Further, if fiddling with these: Wouldn't they better move to macros.h? > > Jan That seems a good suggestion, as they are not compiler-specific. -- Nicola Vetrini, BSc Software Engineer, BUGSENG srl (https://bugseng.com)