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=-3.7 required=3.0 tests=BAYES_00, 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 86A1AC64E7B for ; Thu, 26 Nov 2020 08:36:55 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id CD3DB20DD4 for ; Thu, 26 Nov 2020 08:36:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CD3DB20DD4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=telegraphics.com.au Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=dm-devel-bounces@redhat.com Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-415-CnHz_XMSPbmdYFRY782g_g-1; Thu, 26 Nov 2020 03:36:49 -0500 X-MC-Unique: CnHz_XMSPbmdYFRY782g_g-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E7335107464A; Thu, 26 Nov 2020 08:36:39 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CACF15C1BD; Thu, 26 Nov 2020 08:36:39 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id A2D9150033; Thu, 26 Nov 2020 08:36:39 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 0AQ0Uos2024237 for ; Wed, 25 Nov 2020 19:30:50 -0500 Received: by smtp.corp.redhat.com (Postfix) id 0427A9D47A; Thu, 26 Nov 2020 00:30:50 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast02.extmail.prod.ext.rdu2.redhat.com [10.11.55.18]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F1EC2AE7A7 for ; Thu, 26 Nov 2020 00:30:45 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DEA4C8007DF for ; Thu, 26 Nov 2020 00:30:45 +0000 (UTC) Received: from kvm5.telegraphics.com.au (kvm5.telegraphics.com.au [98.124.60.144]) by relay.mimecast.com with ESMTP id us-mta-193-BzJ6lSsDO7KhfbRJdUxxCg-1; Wed, 25 Nov 2020 19:30:41 -0500 X-MC-Unique: BzJ6lSsDO7KhfbRJdUxxCg-1 Received: from localhost (localhost.localdomain [127.0.0.1]) by kvm5.telegraphics.com.au (Postfix) with ESMTP id 742A42A495; Wed, 25 Nov 2020 19:30:37 -0500 (EST) Date: Thu, 26 Nov 2020 11:30:36 +1100 (AEDT) From: Finn Thain To: Nick Desaulniers In-Reply-To: Message-ID: References: <202011201129.B13FDB3C@keescook> <20201120115142.292999b2@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <202011220816.8B6591A@keescook> <9b57fd4914b46f38d54087d75e072d6e947cb56d.camel@HansenPartnership.com> <0147972a72bc13f3629de8a32dee6f1f308994b5.camel@HansenPartnership.com> <20201123130348.GA3119@embeddedor> <8f5611bb015e044fa1c0a48147293923c2d904e4.camel@HansenPartnership.com> <202011241327.BB28F12F6@keescook> MIME-Version: 1.0 X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-loop: dm-devel@redhat.com X-Mailman-Approved-At: Thu, 26 Nov 2020 03:35:50 -0500 Cc: alsa-devel@alsa-project.org, bridge@lists.linux-foundation.org, target-devel@vger.kernel.org, Greg KH , linux-iio@vger.kernel.org, linux-wireless , linux-mmc@vger.kernel.org, linux-fbdev@vger.kernel.org, dri-devel , "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, linux-i3c@lists.infradead.org, linux1394-devel@lists.sourceforge.net, linux-afs@lists.infradead.org, linux-watchdog@vger.kernel.org, devel@driverdev.osuosl.org, linux-cifs@vger.kernel.org, rds-devel@oss.oracle.com, linux-scsi@vger.kernel.org, linux-acpi@vger.kernel.org, linux-rdma@vger.kernel.org, oss-drivers@netronome.com, linux-atm-general@lists.sourceforge.net, ceph-devel@vger.kernel.org, amd-gfx list , linux-stm32@st-md-mailman.stormreply.com, cluster-devel@redhat.com, usb-storage@lists.one-eyed-alien.net, coreteam@netfilter.org, intel-wired-lan@lists.osuosl.org, linux-input@vger.kernel.org, Miguel Ojeda , Jakub Kicinski , linux-ext4@vger.kernel.org, virtualization@lists.linux-foundation.org, Linux Memory Management List , linux-media@vger.kernel.org, Kees Cook , selinux@vger.kernel.org, linux-arm-msm , intel-gfx@lists.freedesktop.org, linux-sctp@vger.kernel.org, reiserfs-devel@vger.kernel.org, linux-geode@lists.infradead.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, drbd-dev@tron.linbit.com, linux-hams@vger.kernel.org, Nathan Chancellor , linux-can@vger.kernel.org, Linux ARM , linux-hwmon@vger.kernel.org, "maintainer:X86 ARCHITECTURE \(32-BIT AND 64-BIT\)" , linux-nfs@vger.kernel.org, GR-Linux-NIC-Dev@marvell.com, nouveau@lists.freedesktop.org, Network Development , linux-decnet-user@lists.sourceforge.net, samba-technical@lists.samba.org, LKML , Linux-Renesas , linux-security-module@vger.kernel.org, linux-usb@vger.kernel.org, tipc-discussion@lists.sourceforge.net, "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" , Jonathan Cameron , patches@opensource.cirrus.com, Joe Perches , netfilter-devel@vger.kernel.org, linux-integrity@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [dm-devel] [Intel-wired-lan] [PATCH 000/141] Fix fall-through warnings for Clang X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Wed, 25 Nov 2020, Nick Desaulniers wrote: > On Wed, Nov 25, 2020 at 1:33 PM Finn Thain wrote: > > > > Or do you think that a codebase can somehow satisfy multiple checkers > > and their divergent interpretations of the language spec? > > Have we found any cases yet that are divergent? I don't think so. You mean, aside from -Wimplicit-fallthrough? I'm glad you asked. How about -Wincompatible-pointer-types and -Wframe-larger-than? All of the following files have been affected by divergent diagnostics produced by clang and gcc. arch/arm64/include/asm/neon-intrinsics.h arch/powerpc/xmon/Makefile drivers/gpu/drm/i915/Makefile drivers/gpu/drm/i915/i915_utils.h drivers/staging/media/atomisp/pci/atomisp_subdev.c fs/ext4/super.c include/trace/events/qla.h net/mac80211/rate.c tools/lib/string.c tools/perf/util/setup.py tools/scripts/Makefile.include And if I searched for 'smatch' or 'coverity' instead of 'clang' I'd probably find more divergence. Here are some of the relevant commits. 0738c8b5915c7eaf1e6007b441008e8f3b460443 9c87156cce5a63735d1218f0096a65c50a7a32aa babaab2f473817f173a2d08e410c25abf5ed0f6b 065e5e559555e2f100bc95792a8ef1b609bbe130 93f56de259376d7e4fff2b2d104082e1fa66e237 6c4798d3f08b81c2c52936b10e0fa872590c96ae b7a313d84e853049062011d78cb04b6decd12f5c 093b75ef5995ea35d7f6bdb6c7b32a42a1999813 And before you object, "but -Wconstant-logical-operand is a clang-only warning! it can't be divergent with gcc!", consider that the special cases added to deal with clang-only warnings have to be removed when gcc catches up, which is more churn. Now multiply that by the number of checkers you care about. -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel