From patchwork Tue Aug 23 10:17:23 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: 12951953 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 9E752C32772 for ; Tue, 23 Aug 2022 10:20:16 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D272FB306C; Tue, 23 Aug 2022 10:18:54 +0000 (UTC) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id 51D99B2FDE; Tue, 23 Aug 2022 10:17:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1661249878; x=1692785878; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=uWNiR7M8bUT4JAhynBPIOlI6cvuOcXNpkpD1siwzhag=; b=mL+SgThu6xW7P9gWPcJLHIg6r5/5L4lKn4SxuJFVadGpMRiQ0CDZ7saC JUdXeX6/UkZ1XyoK89b3EGi1W8rvHMDJJzdDErE230PLf4T7q8fjSSAwN L4e4W3zMO4kNSrnFiJHsmq0J6ql09f4K081+A+wKOU/WivaC2S3dV3zEP Mk6KADA/lp5UiVhcyZC2vCAXjdmnO+utehQmeATCPVs26FJE4rnXmpJw1 r/WE7dYc9pIEEBUWBMDoQnn54uMJmV11gFSm6Oirwb6f/eX9rLv7UWvgt 5gUCRzwZMbh55VpGRvKJhWTo4UNO7KRgxoQY2Uq8vShPWXc8UST+xwtK2 g==; X-IronPort-AV: E=McAfee;i="6500,9779,10447"; a="273400739" X-IronPort-AV: E=Sophos;i="5.93,257,1654585200"; d="scan'208";a="273400739" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Aug 2022 03:17:57 -0700 X-IronPort-AV: E=Sophos;i="5.93,257,1654585200"; d="scan'208";a="751639913" Received: from jabish-mobl2.amr.corp.intel.com (HELO paris.amr.corp.intel.com) ([10.254.9.209]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Aug 2022 03:17:52 -0700 From: Gwan-gyeong Mun To: intel-gfx@lists.freedesktop.org Subject: [PATCH v8 2/8] util_macros: Add exact_type macro to catch type mis-match while compiling Date: Tue, 23 Aug 2022 19:17:23 +0900 Message-Id: <20220823101729.2098841-3-gwan-gyeong.mun@intel.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220823101729.2098841-1-gwan-gyeong.mun@intel.com> References: <20220823101729.2098841-1-gwan-gyeong.mun@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thomas.hellstrom@linux.intel.com, mauro.chehab@linux.intel.com, andi.shyti@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, intel-gfx-trybot@lists.freedesktop.org, mchehab@kernel.org, nirmoy.das@intel.com Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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