From nobody Sat Apr 11 11:11:36 2026 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 9C217C00140 for ; Sat, 13 Aug 2022 01:09:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235950AbiHMBJK (ORCPT ); Fri, 12 Aug 2022 21:09:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55376 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237585AbiHMBJB (ORCPT ); Fri, 12 Aug 2022 21:09:01 -0400 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDE5E7333B for ; Fri, 12 Aug 2022 18:09:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1660352940; x=1691888940; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=htBXzFuj58kSVBgpeaRLCDJaLlWQVrwWv47Dz051D/g=; b=iUfuIuIKeGi7G4MXOuqOnCWRKZEZJ1a1MS/JvW3tE/czdnZrBmzcFT4y /RaIkmFCue2JKlaJ6iotByD+AKGfT9rAOgPttB6Hg7vgG/z35gAdXNhEu RuBzi8OMDnnyZuYEx8x5nnyOHJJh9A/H4prOQEds8Px/3DAE2bX7bC74O Ib7m4DLLe6BGDegrA+O3s6C9rheAIwmOWyXtHx1LdXC96cG5ecEFdRokd 7cen3Ik6KiorOOgiA0COWjEml8Tkjd5l5GIbHyUdj4S76hPL2PlZzbEVi JbkUGHZttFwOE5f/zYnnNlWcTbxy2b2pVPiKNDyF1t1sAE84Jeu6E7BXY Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10437"; a="271488712" X-IronPort-AV: E=Sophos;i="5.93,233,1654585200"; d="scan'208";a="271488712" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Aug 2022 18:09:00 -0700 X-IronPort-AV: E=Sophos;i="5.93,233,1654585200"; d="scan'208";a="666038345" Received: from akoska-mobl1.ger.corp.intel.com (HELO hades.ger.corp.intel.com) ([10.252.36.156]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Aug 2022 18:08:57 -0700 From: Gwan-gyeong Mun To: intel-gfx@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, mchehab@kernel.org, chris@chris-wilson.co.uk, matthew.auld@intel.com, thomas.hellstrom@linux.intel.com, jani.nikula@intel.com, nirmoy.das@intel.com, airlied@linux.ie, daniel@ffwll.ch, andi.shyti@linux.intel.com, andrzej.hajda@intel.com Subject: [PATCH v6 2/8] util_macros: Add exact_type macro to catch type mis-match while compiling Date: Sat, 13 Aug 2022 04:08:51 +0300 Message-Id: <20220813010857.4043956-3-gwan-gyeong.mun@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220813010857.4043956-1-gwan-gyeong.mun@intel.com> References: <20220813010857.4043956-1-gwan-gyeong.mun@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It adds exact_type and exactly_pgoff_t macro to catch type mis-match while compiling. The existing typecheck() macro outputs build warnings, but the newly added exact_type() macro uses the BUILD_BUG_ON() macro to generate a build break when the types are different and can be used to detect explicit build errors. v6: Move macro addition location so that it can be used by other than drm subsystem (Jani, Mauro, Andi) Signed-off-by: Gwan-gyeong Mun Cc: Thomas Hellstr=C3=B6m Cc: Matthew Auld Cc: Nirmoy Das Cc: Jani Nikula Cc: Andi Shyti Cc: Mauro Carvalho Chehab --- include/linux/util_macros.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/include/linux/util_macros.h b/include/linux/util_macros.h index 72299f261b25..b6624b275257 100644 --- a/include/linux/util_macros.h +++ b/include/linux/util_macros.h @@ -2,6 +2,9 @@ #ifndef _LINUX_HELPER_MACROS_H_ #define _LINUX_HELPER_MACROS_H_ =20 +#include +#include + #define __find_closest(x, a, as, op) \ ({ \ typeof(as) __fc_i, __fc_as =3D (as) - 1; \ @@ -38,4 +41,26 @@ */ #define find_closest_descending(x, a, as) __find_closest(x, a, as, >=3D) =20 +/** + * exact_type - break compile if source type and destination value's type = are + * not the same + * @T: Source type + * @n: Destination value + * + * It is a helper macro for a poor man's -Wconversion: only allow variable= s of + * an exact type. It determines whether the source type and destination va= lue's + * type are the same while compiling, and it breaks compile if two types a= re + * not the same + */ +#define exact_type(T, n) \ + BUILD_BUG_ON(!__builtin_constant_p(n) && !__builtin_types_compatible_p(T,= typeof(n))) + +/** + * exactly_pgoff_t - helper to check if the type of a value is pgoff_t + * @n: value to compare pgoff_t type + * + * It breaks compile if the argument value's type is not pgoff_t type. + */ +#define exactly_pgoff_t(n) exact_type(pgoff_t, n) + #endif --=20 2.34.1