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=-5.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 148F3C19759 for ; Thu, 1 Aug 2019 20:26:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8AB4206A2 for ; Thu, 1 Aug 2019 20:26:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Eo9yKMEb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728682AbfHAU0n (ORCPT ); Thu, 1 Aug 2019 16:26:43 -0400 Received: from mail-lj1-f193.google.com ([209.85.208.193]:33680 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727856AbfHAU0n (ORCPT ); Thu, 1 Aug 2019 16:26:43 -0400 Received: by mail-lj1-f193.google.com with SMTP id h10so70682616ljg.0 for ; Thu, 01 Aug 2019 13:26:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=MEhdMDOICpqniTno2IyVeOoEnON+nzC0j1lyfNgpjMU=; b=Eo9yKMEb9UjAi++MYVMK5w2JPzXXd2oaugL1PU1Z5AnH6kz3xnmZOs1K9xWNqfqtk3 VmwJmljVmwT/qXcmKhfh45Uh6ecLdK8ZrVn4nNFyX8yU9hL5eXTDrpSrOBf5oFGZO5nO d44al570wf7BvRkIywn6UPcXl1x8ppXpPFhrG+cl+drU2V6jH9eqo4KVsx4kBxqAi4pC OQEJLGLLscm10lm5rE5CkfdNXWaH+/dy7OoHKssJERrOJbJC2zFLbkrdsR7iBVQVdyiU y12H66yN83drtr16Wi1D9dr9udO/dkJkJ5DU/xAqOcJZEQRUEG+o0EcVwYFipLJcXpg4 NJ3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MEhdMDOICpqniTno2IyVeOoEnON+nzC0j1lyfNgpjMU=; b=Ki98qIWXiZEYUt7jPMM7DTH1bCG8U+9qgtscqEF7KK3AHfYHJKR4FLPx3OUwrADdtp dEUhPIYlgCIWSKoXc9nF02blJJFxcmJ/dVa0f3Nd8UAlJ5fZZKXFzlmQckEtuc03eozp wOcJkGj1kSsSQooSn/opvv8CEUSPQTxOvUHAyCGfrlQybBQQ2rsn1k0gFK7UdznrUFfG GFr7CdgoO4/etNOamycg5e5Rl6UjfUQEsvPDykTsggJCD7tujFtoYcg+NEfOnwCYq/jx 6XKdSU3dzfvollUL/oHUXEfGigIoeM2fwn7Zrxmbq+7Whf71OHA6TOhhC0+RfeUs0xCr nf5Q== X-Gm-Message-State: APjAAAXpFBndTdrr+gw7WCIx3HTQfXdQ+s8OHlRJI4GdGZq4HQh0Xsf6 t5WVQA8widLkunhB5W/uE73GQ6qE4FY07cd5uSA= X-Google-Smtp-Source: APXvYqybvON8/4Kkvp+5xsl2NJ655igJzUEumv3jvN/U3C/xV9NXsj0vjpoF7F6ksvGlWWbQL/gJvl1ZDgTXm+1shRs= X-Received: by 2002:a2e:3a13:: with SMTP id h19mr52288255lja.220.1564691200817; Thu, 01 Aug 2019 13:26:40 -0700 (PDT) MIME-Version: 1.0 References: <1d2830aadbe9d8151728a7df5b88528fc72a0095.1564549413.git.joe@perches.com> <20190731171429.GA24222@amd> <765E740C-4259-4835-A58D-432006628BAC@zytor.com> <20190731184832.GZ31381@hirez.programming.kicks-ass.net> <20190801122429.GY31398@hirez.programming.kicks-ass.net> <0BCDEED9-0B72-4412-909F-76C20D54983E@zytor.com> In-Reply-To: <0BCDEED9-0B72-4412-909F-76C20D54983E@zytor.com> From: Miguel Ojeda Date: Thu, 1 Aug 2019 22:26:29 +0200 Message-ID: Subject: Re: [RFC PATCH] compiler_attributes.h: Add 'fallthrough' pseudo keyword for switch/case use To: "H. Peter Anvin" Cc: Peter Zijlstra , Joe Perches , Pavel Machek , Linus Torvalds , Kees Cook , Borislav Petkov , Thomas Gleixner , Ingo Molnar , "Gustavo A . R . Silva" , Arnaldo Carvalho de Melo , Kan Liang , Namhyung Kim , Jiri Olsa , Alexander Shishkin , Shawn Landden , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , linux-kernel Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 1, 2019 at 10:10 PM wrote: > > I'm not disagreeing... I think using a macro makes sense. It is either a macro or waiting for 5+ years (while we keep using the comment style) :-) In case it helps to make one's mind about whether to go for it or not, I summarized the advantages and a few other details in the patch I sent in October: https://github.com/ojeda/linux/commit/668f011a2706ea555987e263f609a5deba9c7fc4 It would be nice, however, to discuss whether we want __fallthrough or fallthrough. The former is consistent with the rest of compiler attributes and makes it clear it is not a keyword, the latter is consistent with "break", "goto" and "return", as Joe's patch explains. Cheers, Miguel