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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 13487C2BA1A for ; Tue, 7 Apr 2020 03:09:40 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CBA7C20716 for ; Tue, 7 Apr 2020 03:09:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="PuBLV3jt" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CBA7C20716 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 792F18E006F; Mon, 6 Apr 2020 23:09:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 744348E0062; Mon, 6 Apr 2020 23:09:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6831D8E006F; Mon, 6 Apr 2020 23:09:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0253.hostedemail.com [216.40.44.253]) by kanga.kvack.org (Postfix) with ESMTP id 4D5118E0062 for ; Mon, 6 Apr 2020 23:09:39 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 0CE7C801B354 for ; Tue, 7 Apr 2020 03:09:39 +0000 (UTC) X-FDA: 76679578878.01.gate05_8e6e52f1f6725 X-HE-Tag: gate05_8e6e52f1f6725 X-Filterd-Recvd-Size: 3715 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf15.hostedemail.com (Postfix) with ESMTP for ; Tue, 7 Apr 2020 03:09:38 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5DE6D20769; Tue, 7 Apr 2020 03:09:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586228977; bh=HJSERXQC84Rx9jAaNvTFQy/ltekrPQxpcsK3hTrmo+I=; h=Date:From:To:Subject:In-Reply-To:From; b=PuBLV3jtdacdWslszEoEoAsetZqG549dMqivs1ZzxLA3OJxaiTLJmXyj5JsQ7XxmC Sq+8HVe5v6T0LG/clSEvcBTsQkx50NvKv/U+zi/81imKSei3v7p0pku4pw/oxUGCm+ SS9gKs09H5fggS4G8NmXnx7xZrvYY3p03uN1UNhw= Date: Mon, 06 Apr 2020 20:09:37 -0700 From: Andrew Morton To: abbotti@mev.co.uk, akpm@linux-foundation.org, daniel.santos@pobox.com, joe@perches.com, linux-mm@kvack.org, linux@rasmusvillemoes.dk, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, vegard.nossum@oracle.com, yamada.masahiro@socionext.com Subject: [patch 105/166] compiler.h: fix error in BUILD_BUG_ON() reporting Message-ID: <20200407030937.QP0WCVcPW%akpm@linux-foundation.org> In-Reply-To: <20200406200254.a69ebd9e08c4074e41ddebaf@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Vegard Nossum Subject: compiler.h: fix error in BUILD_BUG_ON() reporting compiletime_assert() uses __LINE__ to create a unique function name. This means that if you have more than one BUILD_BUG_ON() in the same source line (which can happen if they appear e.g. in a macro), then the error message from the compiler might output the wrong condition. For this source file: #include #define macro() \ BUILD_BUG_ON(1); \ BUILD_BUG_ON(0); void foo() { macro(); } gcc would output: ./include/linux/compiler.h:350:38: error: call to `__compiletime_assert_9' declared with attribute error: BUILD_BUG_ON failed: 0 _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) However, it was not the BUILD_BUG_ON(0) that failed, so it should say 1 instead of 0. With this patch, we use __COUNTER__ instead of __LINE__, so each BUILD_BUG_ON() gets a different function name and the correct condition is printed: ./include/linux/compiler.h:350:38: error: call to `__compiletime_assert_0' declared with attribute error: BUILD_BUG_ON failed: 1 _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) Link: http://lkml.kernel.org/r/20200331112637.25047-1-vegard.nossum@oracle.com Signed-off-by: Vegard Nossum Reviewed-by: Masahiro Yamada Reviewed-by: Daniel Santos Cc: Rasmus Villemoes Cc: Ian Abbott Cc: Joe Perches Signed-off-by: Andrew Morton --- include/linux/compiler.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/linux/compiler.h~compilerh-fix-error-in-build_bug_on-reporting +++ a/include/linux/compiler.h @@ -347,7 +347,7 @@ static inline void *offset_to_ptr(const * compiler has support to do so. */ #define compiletime_assert(condition, msg) \ - _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) + _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) #define compiletime_assert_atomic_type(t) \ compiletime_assert(__native_word(t), \ _