From patchwork Fri Sep 9 10:59:07 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: 12971542 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 8A284C6FA82 for ; Fri, 9 Sep 2022 11:00:14 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 072C910EC68; Fri, 9 Sep 2022 10:59:56 +0000 (UTC) Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2738E10EC6A; Fri, 9 Sep 2022 10:59:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1662721191; x=1694257191; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=sw25/VEVNzYbUpj2DtWImbIBzsU8rdEcHgaL9vecVhE=; b=imY5ckQ6J1W1c5oH3/RBA6JWA7LW6AiYVNsvEL9xWPtLNp/ktJo2M6BE oOhfvAp4wx9Y7O6kT4z1XXjO5OyUGVsyX5OwQZDMZwG48doUO6R2WFkHk UpBUuI9Nt8RN/CnfqS0FiFK1CP8QYDH9XwQwjiTy1gN+rMYlDBfXwC6pk TMG/aYpeOLUhlt8TBZKcteGGWoYDs/7S6+ayu2TSHbf053csJvBsBZjQY 5M3jmi6ojiiBMxAGF+5wo9prq6izcyGsD00/JJE1pAKbW6SzGF9HqUuvG 0QKcsIOBm3WiquEWjCIE4z9M9GeYnrlvS9EsYNgDr0D4oBC4SR4B5kk4L w==; X-IronPort-AV: E=McAfee;i="6500,9779,10464"; a="359174665" X-IronPort-AV: E=Sophos;i="5.93,303,1654585200"; d="scan'208";a="359174665" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Sep 2022 03:59:48 -0700 X-IronPort-AV: E=Sophos;i="5.93,303,1654585200"; d="scan'208";a="704370341" Received: from clbarnes-mobl.amr.corp.intel.com (HELO paris.amr.corp.intel.com) ([10.254.42.92]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Sep 2022 03:59:44 -0700 From: Gwan-gyeong Mun To: intel-gfx@lists.freedesktop.org Subject: [PATCH v10 3/9] compiler_types.h: Add assert_type to catch type mis-match while compiling Date: Fri, 9 Sep 2022 19:59:07 +0900 Message-Id: <20220909105913.752049-4-gwan-gyeong.mun@intel.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220909105913.752049-1-gwan-gyeong.mun@intel.com> References: <20220909105913.752049-1-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, ndesaulniers@google.com, dlatypov@google.com, linux@rasmusvillemoes.dk, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, andrzej.hajda@intel.com, matthew.auld@intel.com, airlied@redhat.com, mchehab@kernel.org, vitor@massaru.org, nirmoy.das@intel.com Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" It adds assert_type and assert_typable macros to catch type mis-match while compiling. The existing typecheck() macro outputs build warnings, but the newly added assert_type() macro uses the _Static_assert() keyword (which is introduced in C11) to generate a build break when the types are different and can be used to detect explicit build errors. Unlike the assert_type() macro, assert_typable() macro allows a constant value as the second argument. Suggested-by: Kees Cook 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 Cc: Andrzej Hajda Cc: Kees Cook --- include/linux/compiler_types.h | 39 ++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index 4f2a819fd60a..19cc125918bb 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -294,6 +294,45 @@ struct ftrace_likely_data { /* Are two types/vars the same type (ignoring qualifiers)? */ #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) +/** + * assert_type - break compile if the first argument's data type and the second + * argument's data type are not the same + * + * @t1: data type or variable + * @t2: data type or variable + * + * The first and second arguments can be data types or variables or mixed (the + * first argument is the data type and the second argument is variable or vice + * versa). It determines whether the first argument's data type and the second + * argument's data type are the same while compiling, and it breaks compile if + * the two types are not the same. + * See also assert_typable(). + */ +#define assert_type(t1, t2) _Static_assert(__same_type(t1, t2)) + +/** + * assert_typable - break compile if the first argument's data type and the + * second argument's data type are not the same + * + * @t: data type or variable + * @n: data type or variable or constant value + * + * The first and second arguments can be data types or variables or mixed (the + * first argument is the data type and the second argument is variable or vice + * versa). Unlike the assert_type() macro, this macro allows a constant value + * as the second argument. And if the second argument is a constant value, it + * always passes. And it doesn't mean that the types are explicitly the same. + * When a constant value is used as the second argument, if you need an + * overflow check when assigning a constant value to a variable of the type of + * the first argument, you can use the overflows_type() macro. When a constant + * value is not used as a second argument, it determines whether the first + * argument's data type and the second argument's data type are the same while + * compiling, and it breaks compile if the two types are not the same. + * See also assert_type() and overflows_type(). + */ +#define assert_typable(t, n) _Static_assert(__builtin_constant_p(n) || \ + __same_type(t, typeof(n))) + /* * __unqual_scalar_typeof(x) - Declare an unqualified scalar type, leaving * non-scalar types unchanged.