From patchwork Wed Aug 24 08:45:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Gwan-gyeong Mun X-Patchwork-Id: 12953051 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 364B2C00140 for ; Wed, 24 Aug 2022 08:46:02 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1D97110F09C; Wed, 24 Aug 2022 08:46:00 +0000 (UTC) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3018F10F09C; Wed, 24 Aug 2022 08:45:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1661330735; x=1692866735; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=uWNiR7M8bUT4JAhynBPIOlI6cvuOcXNpkpD1siwzhag=; b=bR9Qn8//HPNLY+nH+ZEYu4iwTetoAuUWvrPWDthMaINP6lonhgob7eLv r5eiTq5ZWfkl88Zr6STUdkmemLf5zV+23FiF8bSW3qX2GAE9aYjzhd3Li enA8ETkYgFSdSO/iDFIaMRn1JqNjx72XNxZSj4/WeXAxPK2UDkwTJfULX wtjpjDGOSsFScMWsEsB/VcjnnqJdv1zbVnc0Nk3X6QqlAXP0DKF8coym1 0RzSTsE6xPzA64tx7pEWREEDNeYru5c76HfP+kmM15D+ud445qafBTjlG z4pU0q8tPKASb6zZVmnwBqDyALaGGd24VivAnru0L14uoq637LToTv7Yt A==; X-IronPort-AV: E=McAfee;i="6500,9779,10448"; a="291473663" X-IronPort-AV: E=Sophos;i="5.93,260,1654585200"; d="scan'208";a="291473663" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Aug 2022 01:45:34 -0700 X-IronPort-AV: E=Sophos;i="5.93,260,1654585200"; d="scan'208";a="785553971" Received: from yuhsuanc-mobl.gar.corp.intel.com (HELO paris.amr.corp.intel.com) ([10.254.38.238]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Aug 2022 01:45:31 -0700 From: Gwan-gyeong Mun To: intel-gfx@lists.freedesktop.org Date: Wed, 24 Aug 2022 17:45:08 +0900 Message-Id: <20220824084514.2261614-3-gwan-gyeong.mun@intel.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220824084514.2261614-1-gwan-gyeong.mun@intel.com> References: <20220824084514.2261614-1-gwan-gyeong.mun@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v9 2/8] util_macros: Add exact_type macro to catch type mis-match while compiling X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thomas.hellstrom@linux.intel.com, keescook@chromium.org, jani.nikula@intel.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, airlied@linux.ie, andrzej.hajda@intel.com, matthew.auld@intel.com, daniel@ffwll.ch, intel-gfx-trybot@lists.freedesktop.org, mchehab@kernel.org, nirmoy.das@intel.com Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" 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 Hellström 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_ +#include +#include + #define __find_closest(x, a, as, op) \ ({ \ typeof(as) __fc_i, __fc_as = (as) - 1; \ @@ -38,4 +41,26 @@ */ #define find_closest_descending(x, a, as) __find_closest(x, a, as, >=) +/** + * 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 variables of + * an exact type. It determines whether the source type and destination value's + * type are the same while compiling, and it breaks compile if two types are + * 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