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=-10.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 AF154C55185 for ; Tue, 20 Oct 2020 13:56:10 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (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 2F21522265 for ; Tue, 20 Oct 2020 13:56:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="dqj1hqYp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F21522265 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 87FAD15D8EF46; Tue, 20 Oct 2020 06:56:09 -0700 (PDT) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=216.205.24.124; helo=us-smtp-delivery-124.mimecast.com; envelope-from=trix@redhat.com; receiver= Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 6867215D8EF42 for ; Tue, 20 Oct 2020 06:56:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603202165; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HyQ28xr5/lapv6azTtFCvHFT5XQ1+OzeHk+84iEm66Y=; b=dqj1hqYpU6/y2h8V+kIQptv0xhdOCg30nYjG0UuQPR4HzPGpwcXs8bTMbLhH/MZ4iyaOGe bIsQLktd/HxsejJ6iD6T7AP53V0El8WD9AX/eQ5RKofX+tIH76o2/BtELPXTXNDVWD5wEg LuY4RW3ZSsnbV2leAXQmqfUp5Xe8+Ec= Received: from mail-qv1-f70.google.com (mail-qv1-f70.google.com [209.85.219.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-591-xiDZWBruOB2DtID8CGvkwg-1; Tue, 20 Oct 2020 09:56:01 -0400 X-MC-Unique: xiDZWBruOB2DtID8CGvkwg-1 Received: by mail-qv1-f70.google.com with SMTP id s1so1433120qvq.13 for ; Tue, 20 Oct 2020 06:56:01 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=HyQ28xr5/lapv6azTtFCvHFT5XQ1+OzeHk+84iEm66Y=; b=WIr6b9Lz6gm2a+WRidDdeZ3ojXuVBitryIY8k/5TN48AEJJg2flMP36BB0HLwoipJa jX5ykFXKQycnZ088b8F5epxKCb3YrIqlYnrTUEF4V5DowA/DPG1nB8MvDKe4fPR1Ar3m 6y9qrDxZsSotsjnkf22h+AK4Ovo/QkWBmZFK629UiZe4bmwlxIxLRVyp7YzUedR8fEe0 oj3ZuXWGOfNMdGjddw1vl+fqx99+SeCuvYzwLUeROFJnvMwWS0vbsqw5CU6kIyGV7viX VPRQKIyUAz94Ijz3hjXgR5WDwPQzrLPDxHIK1a6/LgkBuAxQ2xVJBwSDXrQrzXzkdfGx xfaQ== X-Gm-Message-State: AOAM531UTDUIXBhdB4vr3Dgtkpk5JpBGKeVleVXdAIBNIPG98L61YbzJ ygP9JQlfpRGZJdVU83QB+uwPiQ4/8grINQtnUrZLC44qom0fI06eouIul4bzPW9EVgVE/8p+BEs Wbg/s1oMy5OGIXY27fnUY X-Received: by 2002:a05:6214:174f:: with SMTP id dc15mr3370450qvb.25.1603202160689; Tue, 20 Oct 2020 06:56:00 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyLUAfqrAOJzxwKF3+voCBF5yQYNbMOvfOkDZhumkJj3bEnT15V4x8vUJ5iQ5pWt9KusIZtsQ== X-Received: by 2002:a05:6214:174f:: with SMTP id dc15mr3370377qvb.25.1603202160139; Tue, 20 Oct 2020 06:56:00 -0700 (PDT) Received: from trix.remote.csb (075-142-250-213.res.spectrum.com. [75.142.250.213]) by smtp.gmail.com with ESMTPSA id b8sm775938qkn.133.2020.10.20.06.55.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 20 Oct 2020 06:55:59 -0700 (PDT) Subject: Re: [RFC] treewide: cleanup unreachable breaks To: Nick Desaulniers References: <20201017160928.12698-1-trix@redhat.com> <20201018054332.GB593954@kroah.com> From: Tom Rix Message-ID: Date: Tue, 20 Oct 2020 06:55:52 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=trix@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Message-ID-Hash: O3KP5MOWEQ74YYXNUN7PMIOMFDU2HIQH X-Message-ID-Hash: O3KP5MOWEQ74YYXNUN7PMIOMFDU2HIQH X-MailFrom: trix@redhat.com X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: LKML , linux-edac@vger.kernel.org, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, xen-devel@lists.xenproject.org, linux-block@vger.kernel.org, openipmi-developer@lists.sourceforge.net, "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" , Linux ARM , linux-power@fi.rohmeurope.com, linux-gpio@vger.kernel.org, amd-gfx list , dri-devel , nouveau@lists.freedesktop.org, virtualization@lists.linux-foundation.org, spice-devel@lists.freedesktop.org, linux-iio@vger.kernel.org, linux-amlogic@lists.infradead.org, industrypack-devel@lists.sourceforge.net, linux-media@vger.kernel.org, MPT-FusionLinux.pdl@broadcom.com, linux-scsi@vger.kernel.org, linux-mtd@lists.infradead.org, linux-can@vger.kernel.org, Network Development , intel-wired-lan@lists.osuosl.org, ath10k@lists.infradead.org, linux-wireless , linux-stm32@st-md-mailman.stormreply.com, linux-nfc@lists.01.org, linux-nvdimm , linux-pci@vger.kernel.org, linux-samsung-soc@vger.kernel.org, platform-driver-x86@vger.kernel.org, patches@opensource.cirrus.com, storagedev@microchip.com, devel@driverdev.osuosl.org, linux-serial@vger.kernel.org, linux-usb@vger.kernel.org, usb-storage@lists.one-eyed-alien.net, linux-watchdog@vger.kernel.org, ocfs2-devel@oss.oracle.com, bpf , linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, alsa-devel@alsa-project.org, clang-built-linux , Greg KH , George Burgess , Joe Perches X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On 10/19/20 12:42 PM, Nick Desaulniers wrote: > On Sat, Oct 17, 2020 at 10:43 PM Greg KH wrote: >> On Sat, Oct 17, 2020 at 09:09:28AM -0700, trix@redhat.com wrote: >>> From: Tom Rix >>> >>> This is a upcoming change to clean up a new warning treewide. >>> I am wondering if the change could be one mega patch (see below) or >>> normal patch per file about 100 patches or somewhere half way by collecting >>> early acks. >> Please break it up into one-patch-per-subsystem, like normal, and get it >> merged that way. >> >> Sending us a patch, without even a diffstat to review, isn't going to >> get you very far... > Tom, > If you're able to automate this cleanup, I suggest checking in a > script that can be run on a directory. Then for each subsystem you > can say in your commit "I ran scripts/fix_whatever.py on this subdir." > Then others can help you drive the tree wide cleanup. Then we can > enable -Wunreachable-code-break either by default, or W=2 right now > might be a good idea. I should have waited for Joe Perches's fixer addition to checkpatch :) The easy fixes I did only cover about 1/2 of the problems. Remaining are mostly nested switches, which from a complexity standpoint is bad. > > Ah, George (gbiv@, cc'ed), did an analysis recently of > `-Wunreachable-code-loop-increment`, `-Wunreachable-code-break`, and > `-Wunreachable-code-return` for Android userspace. From the review: > ``` > Spoilers: of these, it seems useful to turn on > -Wunreachable-code-loop-increment and -Wunreachable-code-return by > default for Android In my simple add-a-cflag bot, i see there are about 250 issues for -Wunreachable-code-return. I'll see about doing this one next. > ... > While these conventions about always having break arguably became > obsolete when we enabled -Wfallthrough, my sample turned up zero > potential bugs caught by this warning, and we'd need to put a lot of > effort into getting a clean tree. So this warning doesn't seem to be > worth it. > ``` > Looks like there's an order of magnitude of `-Wunreachable-code-break` > than the other two. > > We probably should add all 3 to W=2 builds (wrapped in cc-option). > I've filed https://github.com/ClangBuiltLinux/linux/issues/1180 to > follow up on. Yes, i think think these should be added. Tom _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org