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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 4571CFCB624 for ; Fri, 6 Mar 2026 23:17:21 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4fSMkR2xBPz3c9y; Sat, 07 Mar 2026 10:17:19 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip="2600:3c04:e001:324:0:1991:8:25" ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1772839039; cv=none; b=QzlL+lhV7AJ1aEyc26ZWL1NNRWJ4szowBv4rngwF4blu+60EDdGRuPVSInqDiUbdkPjxlXKo/AA31YNhWNST/02UUVyC8VkIlMPMWtkGRKSjlUqmik3lLIFL64ab9yakq0NggsdSkXJ6b/OMJ96xfBOPTFEK7u9h2K8AGh1P4WD1y4auQoj5RyQO/Hg1x0jc45A2bfzZq+9UbC6tloisv7/JpZAnef2epUsruz/uVwbqUF4mBqIbwgN40yNUhTLdG3wh2N+Z8cGDbkJudNYesPlmixwZucDwarmrsdZD9UEOKLRmeIcox98izL8v9CfOo4n1TqOlYepPOYlnKGpP9A== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1772839039; c=relaxed/relaxed; bh=8ZR7Dp2IPiEMUD6BfjnRAuZaSEUl5mI6F5vABdqGEZ0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ViK4sj5qQcZQf6eMvUt98xeNwFW6OsIw1XZNF/2ammAXFaq2z0Sht10mgt5vEvkGYcoMidMYP3XxjpXGRWPyr5QgGjVdV2T3XlKx/mUE382sAdo//hMsS61rlVoXOXddJJOJxSjr+cfPMz6yXS4o4yielq10c8todi0b4VKyeiVmGWVOP7jaySmILb3UBW/FixTxBMeRZbddaQRBCcEEs5M2XURgkFXmy66ioLO9PYs0TnGrlOmRgn1LpO9PaVrZU6VWxMDUPVCCuxz8JV8hiaV/x33UGSe18Zxkr1xO1jtEYF05n36OJ2MmZoAw1XCQzlAZfeEPzv5DftAWawmCvA== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=CiNTmhly; dkim-atps=neutral; spf=pass (client-ip=2600:3c04:e001:324:0:1991:8:25; helo=tor.source.kernel.org; envelope-from=nathan@kernel.org; receiver=lists.ozlabs.org) smtp.mailfrom=kernel.org Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=CiNTmhly; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2600:3c04:e001:324:0:1991:8:25; helo=tor.source.kernel.org; envelope-from=nathan@kernel.org; receiver=lists.ozlabs.org) Received: from tor.source.kernel.org (tor.source.kernel.org [IPv6:2600:3c04:e001:324:0:1991:8:25]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4fSMkQ11Gmz3c9l for ; Sat, 07 Mar 2026 10:17:18 +1100 (AEDT) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 79D9260018; Fri, 6 Mar 2026 23:17:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 86B13C4CEF7; Fri, 6 Mar 2026 23:17:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772839035; bh=A/uuCYUUHbNrrdKdzYdGzSe5pMInGIZfaSIgsjBFQtg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CiNTmhly2/1kTdtRkuNAgOXwAQT7A+wQx51m3gawq6ph2TOb1AmR20TS/sy1txYNU iElaZlD0mEOexw6DRDS/H4TTDu/pyj/oV6d7iSt93lYyho/X6/HC8T986ocCrdSX8f W0fMhB4DiENlMrX0hKOJVXylpR8JdeJwPK1us4hrvgF/gpr5p0tTJy8J9/hBJuGZ7x J6oOaB9DvzC1IcXPWbDiXcwZ6M+56B4nTerYJlMNfl+KbCI8z/0xfmHkRzg6Ie7YMn mh/kZD1RDkMqTowspybgiAXSVWjmzHV1BRX2XnLenj50feqtNdUtqkWd/KSVt0jhRK 6S7laj3n5tF8A== Date: Fri, 6 Mar 2026 16:17:05 -0700 From: Nathan Chancellor To: "H. Peter Anvin" Cc: Nicolas Schier , Linus Torvalds , Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , "James E.J. Bottomley" , Helge Deller , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Ard Biesheuvel , Ilias Apalodimas , Nick Desaulniers , Bill Wendling , Justin Stitt , Kees Cook , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-efi@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH 0/2] kbuild: Switch from '-fms-extensions' to '-fms-anonymous-structs' when available Message-ID: <20260306231705.GD2746259@ax162> References: <20260223-fms-anonymous-structs-v1-0-8ee406d3c36c@kernel.org> <01433066-eb9b-4a96-8d7f-794af941d365@zytor.com> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <01433066-eb9b-4a96-8d7f-794af941d365@zytor.com> On Thu, Mar 05, 2026 at 03:43:29PM -0800, H. Peter Anvin wrote: > Question: does clang allow this with __extension__, or only if the option is > on the command line? It would be desirable in the long run if both clang and It looks like only on the command line: https://godbolt.org/z/zrE766obe > gcc would allow this with __extension__, as that would be required to use it > in uapi headers (at least without some doable-but-nontrivial preprocessing, > which might be worthwhile to do anyway...) I agree that would be desirable but wouldn't that change how __extension__ works? As far as I can tell from reading GCC's documentation [1], __extension__ just supresses warnings from -pedantic and such, it does not actually enable a used extension if it conflicts with whatever -std= value is passed? [1]: https://gcc.gnu.org/onlinedocs/gcc/Alternate-Keywords.html Cheers, Nathan