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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE626C433F5 for ; Sun, 21 Nov 2021 13:22:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238169AbhKUN0A (ORCPT ); Sun, 21 Nov 2021 08:26:00 -0500 Received: from mout.kundenserver.de ([217.72.192.75]:46559 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235784AbhKUNZ6 (ORCPT ); Sun, 21 Nov 2021 08:25:58 -0500 Received: from mail-oi1-f181.google.com ([209.85.167.181]) by mrelayeu.kundenserver.de (mreue109 [213.165.67.113]) with ESMTPSA (Nemesis) id 1MhDEq-1mAnQU2Ip0-00eNrR for ; Sun, 21 Nov 2021 14:22:52 +0100 Received: by mail-oi1-f181.google.com with SMTP id u74so32065547oie.8 for ; Sun, 21 Nov 2021 05:22:52 -0800 (PST) X-Gm-Message-State: AOAM532+41yuoYi07N+OrOidACkIQJfLtOKyDqsTHrzyRfKylyEsPCPK TsYsMevn29WT1Gl0UGd6BK/i0UVXDq+MdEQJUBc= X-Google-Smtp-Source: ABdhPJybfj2Q05kRsPidGHVDIIvlvg+f4Wl8ZN+iqjQ1GX5CzQraZCZa8cfvJntrul20Et+GsvTB3RSZ1sNVT+pxfqc= X-Received: by 2002:a54:4e93:: with SMTP id c19mr14354275oiy.11.1637500971244; Sun, 21 Nov 2021 05:22:51 -0800 (PST) MIME-Version: 1.0 References: <20211119113644.1600-1-alx.manpages@gmail.com> <20211120130104.185699-1-alx.manpages@gmail.com> <20211120130104.185699-19-alx.manpages@gmail.com> In-Reply-To: <20211120130104.185699-19-alx.manpages@gmail.com> From: Arnd Bergmann Date: Sun, 21 Nov 2021 14:22:35 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 17/20] linux/array_size.h: Add __is_array(a) to help readability To: Alejandro Colomar Cc: LKML , Andy Shevchenko , Arnd Bergmann , Alexey Dobriyan , Jani Nikula , Rasmus Villemoes , Kees Cook , Joe Perches Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:IA2El5SrIAoN9i+8tiMblwu/ohhKvZFeUz/0joHnOYE+5a0HEp4 kb8w32a7nVKFxGERVzPAPZwmJ6gci/An+4YECMXzWY24FfYr/OTY82kY2E7JMqpoAucHy7t JVF+2Utygq4Zyo7il9+HGuBtIpibj6KaJcd/UzEv1K8SeMFuU/4yP+f9Kk/Y78tA1fPWHlF fMvSIGlSzqq0A5D/nm1Qg== X-UI-Out-Filterresults: notjunk:1;V03:K0:tEPBtjaAT+Y=:FZSdNOLIaEfkT4yJGyQ7c/ 3nJ3Vl/ncoHi/ejZFKRSbA84jlMKw43uPdkn/pstBTaKMMz4Ci246sqMpbpT9uCsgaMuC+dZR a4f1ApoKUymcYuQtSU2EmljmxDJsmPht6bRBvdDkmE/mi4V3RSWUFkVOi6cci4EDAGFS+5rC7 m9mq2q/Lhxw7esKw9zA9+q/AX24Cu5ywJ95t1nJbFVX8pJhlKoKEJFuFcl594nuwi8oRwoeZN ajhhhoxuJ/hLmNrH42NSR8wMfvYNeCGUhX7GsFg+lAl/QdGs03D5HKbkgrgVVH4d8Fz9SfQyM JA5jVpPGyw3MB9G6Giao3YP5j4+zc3aQUin3tnb/rkyIkrbKl4uyl7FRcRedajHaAXQKCNL/e b0ljaB3h2g7pXfbZnvK/Edx1XaOrzgf6F6QP1jsErfnjNfpS7VnZBDZAnG5BXZtJbIOK0P5XO UVsLqY3mgHYMjzRnZKUam9sl4460cfS5tc1/9hvmLRFE5JsQRsBwDOuNr6PrGeFyjar1j0N/0 v7K21G84qlGcaqjLh+H5VMCr5ijsQyY924HXk31sbA+bqULxRfD2lPKYqz+j2nxfmgUgI4eOW wPc8Gb/zvCAnpnegNFdz3oofCLV7KvNU/aFYHf5ZB7b7JJr2sD4Ykm6b41UrkfnevbfW0SBTG cTwAHRTL+/BypbtZu63pmDL9NhhJSDqWGl1RXXQXl/6pkUFEI3Zc1Z+fRHGHP+Jje2prxSJGH YBPhW7pO+nxQwzlZ9No03ejyNHuaViAYrE1YOAqbr5ApwA5Bz6Xtj8tDnolCsQlH67G95aIiO ir0E4PolU79nGmzWXLzamENIQN5pHNWnSlawVIauFqloO/rqiQ= Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Nov 20, 2021 at 2:01 PM Alejandro Colomar wrote: > > /* &a[0] degrades to a pointer: a different type from an array */ > -#define __must_be_array(a) __must_be(!__same_type((a), &(a)[0])) > +#define __is_array(a) (!__same_type((a), &(a)[0])) > + > +#define __must_be_array(a) __must_be(__is_array(a)) I'd go the other way here if you want to improve this, and open-code it to avoid nested macros. That produces more readable error messages with recent compilers that try to unwind each macro one at a time. Arnd