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=-0.7 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 3D035C2D0E4 for ; Tue, 24 Nov 2020 17:13:37 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5DE8D206E5 for ; Tue, 24 Nov 2020 17:13:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="hxmhMgJD"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="uc3VE1PZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5DE8D206E5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id DD6EB17CF; Tue, 24 Nov 2020 18:12:44 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz DD6EB17CF DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1606238015; bh=Bp6pkc2/lFSi9rlRAbELhmN+t8o/9hJa3MjIIS8lCR4=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=hxmhMgJDwUsiulQFM1Nn5Xf+ERHgVXAEnro3a/HHXithZtwFcRzRCFW7uUhHEAJVZ frQTep0Oc9Sg3H19G5b88YdqvaR1zkqRiVhWSVn3ftX8R+BlMfuDq4UBAlv8ZiIu9K sMmy/Hl/8P6u1ZWHnvliPr3b7PWiB5Vy+kHZaZII= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id EFF66F805EB; Tue, 24 Nov 2020 17:58:44 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 5D4B7F80255; Mon, 23 Nov 2020 15:05:53 +0100 (CET) Received: from mail-yb1-xb41.google.com (mail-yb1-xb41.google.com [IPv6:2607:f8b0:4864:20::b41]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id F095AF80128 for ; Mon, 23 Nov 2020 15:05:46 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz F095AF80128 Authentication-Results: alsa1.perex.cz; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="uc3VE1PZ" Received: by mail-yb1-xb41.google.com with SMTP id 2so15993105ybc.12 for ; Mon, 23 Nov 2020 06:05:46 -0800 (PST) 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=RhHqKgQbKUW77nc47JuvCnp+w8QNxENxQLSt6AHkTqQ=; b=uc3VE1PZNnY/Z1NgZXLeWe/Nj5hsoBfQkeeHXaE+d0SDr9xNRMPYxU1o6fpuaiqkgi yuFjhawxyOxFbziEfkWs4inb92LCIVTnNTVXAL7657JtY5jUPnHae9XC4JONvfltcDzK 9TpDS0ylXwfesoyru6or5tLuj2Wgq4fxc0XGG5evkxw7F5K63x1NbbMukm854FcfQLy0 gnTDe+NWIPcxyPxl6ZwlkcZY1OnasK1C98JFaIzSzrlrdcg6icgY2nCNokwGspTvBpMG u0c2fJxhgJsKPBZAzgP85ZG8VhKJUulmNcJ8sZ+phgCZ9U4trQ3IF/NnqsJiuQ1qY+5Q UH8Q== 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=RhHqKgQbKUW77nc47JuvCnp+w8QNxENxQLSt6AHkTqQ=; b=WwfXPcZNSpxvI/DPqmGeQEGIBeMBRnZ4oomw4fv5s2mAu8MhVnU8SifHloEnwk54tp M1l2NlyzIB+SG0rRsueoYtUJ6RtNgO/PYCoPoMamikl5aHcT5eCnlHv0kAiXIdiQdugG aXywBDEmUrZAdrfCUAADjO3IZ55hHFFeymRzOi5hW7fYVCrmfk1ZIpy059ZXk2f3xcux nYu3UNkJ9axmVk1nSQor7V7ENwiprFqhCQZOegR5bsPEP6zb9SVHVtrJzLNymdkVXFlr PLwSkPGv0P5OKy/98+fxFs7AaLwJ7zj0NCYMg4IwJSj8OM8Jz56NmOTOuavzkQtC1qIp 3qyQ== X-Gm-Message-State: AOAM532EbodbgQHt7h0CHptz3GGV5Xda+S1ZzMRc7AEmD309v9QS0cVO P857u8zMEiDcxYDCiS/xtdLvFMaXXPtBY5k93jI= X-Google-Smtp-Source: ABdhPJz9DsZ58e7OIIOr/VE9Xtax3PWaLuFuRyVLpjTsCzIYcuPGWJiVUhGusztX9v02ET+47HU3GtURC6oS5LfC9Lw= X-Received: by 2002:a5b:40e:: with SMTP id m14mr35121900ybp.33.1606140343388; Mon, 23 Nov 2020 06:05:43 -0800 (PST) MIME-Version: 1.0 References: <20201120105344.4345c14e@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <202011201129.B13FDB3C@keescook> <20201120115142.292999b2@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <202011220816.8B6591A@keescook> <9b57fd4914b46f38d54087d75e072d6e947cb56d.camel@HansenPartnership.com> In-Reply-To: From: Miguel Ojeda Date: Mon, 23 Nov 2020 15:05:31 +0100 Message-ID: Subject: Re: [PATCH 000/141] Fix fall-through warnings for Clang To: Finn Thain Content-Type: text/plain; charset="UTF-8" X-Mailman-Approved-At: Tue, 24 Nov 2020 17:58:08 +0100 Cc: alsa-devel@alsa-project.org, linux-atm-general@lists.sourceforge.net, reiserfs-devel@vger.kernel.org, linux-iio@vger.kernel.org, linux-wireless , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, "Gustavo A. R. Silva" , James Bottomley , linux-ide@vger.kernel.org, dm-devel@redhat.com, keyrings@vger.kernel.org, linux-mtd@lists.infradead.org, GR-everest-linux-l2@marvell.com, wcn36xx@lists.infradead.org, samba-technical@lists.samba.org, linux-i3c@lists.infradead.org, linux1394-devel@lists.sourceforge.net, linux-afs@lists.infradead.org, usb-storage@lists.one-eyed-alien.net, drbd-dev@lists.linbit.com, devel@driverdev.osuosl.org, linux-cifs@vger.kernel.org, rds-devel@oss.oracle.com, Nick Desaulniers , linux-scsi@vger.kernel.org, Nathan Chancellor , linux-rdma@vger.kernel.org, oss-drivers@netronome.com, bridge@lists.linux-foundation.org, linux-security-module@vger.kernel.org, amd-gfx@lists.freedesktop.org, linux-stm32@st-md-mailman.stormreply.com, cluster-devel@redhat.com, linux-acpi@vger.kernel.org, coreteam@netfilter.org, intel-wired-lan@lists.osuosl.org, linux-input , Miguel Ojeda , Jakub Kicinski , Ext4 Developers List , Linux Media Mailing List , Kees Cook , selinux@vger.kernel.org, linux-arm-msm@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-geode@lists.infradead.org, linux-can@vger.kernel.org, linux-block@vger.kernel.org, linux-gpio@vger.kernel.org, op-tee@lists.trustedfirmware.org, linux-mediatek@lists.infradead.org, xen-devel@lists.xenproject.org, nouveau@lists.freedesktop.org, linux-hams@vger.kernel.org, ceph-devel@vger.kernel.org, virtualization@lists.linux-foundation.org, Linux ARM , linux-hwmon@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-nfs@vger.kernel.org, GR-Linux-NIC-Dev@marvell.com, tipc-discussion@lists.sourceforge.net, Linux-MM , Network Development , linux-decnet-user@lists.sourceforge.net, linux-mmc@vger.kernel.org, linux-kernel , "maintainer:X86 ARCHITECTURE \(32-BIT AND 64-BIT\)" , linux-renesas-soc@vger.kernel.org, linux-sctp@vger.kernel.org, linux-usb@vger.kernel.org, netfilter-devel@vger.kernel.org, Linux Crypto Mailing List , patches@opensource.cirrus.com, Joe Perches , linux-integrity@vger.kernel.org, target-devel@vger.kernel.org, linux-hardening@vger.kernel.org X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" On Sun, Nov 22, 2020 at 11:54 PM Finn Thain wrote: > > We should also take into account optimisim about future improvements in > tooling. Not sure what you mean here. There is no reliable way to guess what the intention was with a missing fallthrough, even if you parsed whitespace and indentation. > It is if you want to spin it that way. How is that a "spin"? It is a fact that we won't get *implicit* fallthrough mistakes anymore (in particular if we make it a hard error). > But what we inevitably get is changes like this: > > case 3: > this(); > + break; > case 4: > hmmm(); > > Why? Mainly to silence the compiler. Also because the patch author argued > successfully that they had found a theoretical bug, often in mature code. If someone changes control flow, that is on them. Every kernel developer knows what `break` does. > But is anyone keeping score of the regressions? If unreported bugs count, > what about unreported regressions? Introducing `fallthrough` does not change semantics. If you are really keen, you can always compare the objects because the generated code shouldn't change. Cheers, Miguel