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=-6.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 A56CEC433DF for ; Sat, 17 Oct 2020 21:01:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 60B25207BC for ; Sat, 17 Oct 2020 21:01:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=intel-com.20150623.gappssmtp.com header.i=@intel-com.20150623.gappssmtp.com header.b="ntIAxdfj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439163AbgJQVBg (ORCPT ); Sat, 17 Oct 2020 17:01:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2439244AbgJQVBf (ORCPT ); Sat, 17 Oct 2020 17:01:35 -0400 Received: from mail-ej1-x643.google.com (mail-ej1-x643.google.com [IPv6:2a00:1450:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B746C061755 for ; Sat, 17 Oct 2020 14:01:34 -0700 (PDT) Received: by mail-ej1-x643.google.com with SMTP id c22so8494402ejx.0 for ; Sat, 17 Oct 2020 14:01:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=QU5tUnKrk3cCgEOM6DUuSpHohPcIoidzngrqxPrVqlg=; b=ntIAxdfj5B3UZZJPAO3W3zqpuYJdxZe6wmMN+Cg5+tfh5QjsxLbXR5o2amfdJQ2J48 +r9G2vZiMs4S/e6t6kNU+/1RisTXP2Yspklt8lksB4PhSQjsUISEYusYJeN2p0XCHoqr 5tX/QI+fZe3GQZJaviemAIYQlGxoIFC7s6aX8R5MJQLi2SOYJ/keQbrc62HNUeJ8pCOI 7WYztP0OE4axPIRoGDfVK4aq4k9dPY6fZ69Y4fL3/a70qb0GrKtNhloBSbp9yIhwtpgg UECkhdkcAFyI2jUc3qFZfU7NKoc+E1dZJHZxhONiRQFFV//aVnbaYjp+hfJUaNjfh3TU ik3w== 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=QU5tUnKrk3cCgEOM6DUuSpHohPcIoidzngrqxPrVqlg=; b=PFsZ8VpxjWeU5irbFekmHFIJyOmTwalAegU7p6HLt+T1lmVYGCozAxc35W/U10UIGo Q0u6VypBYLGUjWZswIYl91O1iaN6kz9HZsB7P6QJKQUKSzO6cPq/pbdA3+jTjt0YixlW avvtk+DA0uRdPwFWnRNG+vT3q/lGdZI7r/1E+kTlNhdtlK2k6L6WxhLwr5bT5fx9zG6s LDZt3jQ9d++JOqcDviYGvJ4yyWBB9LS2v/0vQmvyp9+QB6FNWM3Qy9OGeyiKM8Evx2b5 7A9YxXfHGwa0mei7qMUxD6Be7eCIfsk9HniKunPKdTPa6d7ABChXB6RN+9St3uFC4J3j Nodw== X-Gm-Message-State: AOAM531i4uo0qoTutECy9jY8S/KF/U7MDsJr6tXEVtBd6M3+BYGaZTjx pvVTJhrpKYl9QdTJVt8v49puAVAe1d6XRPWApM2g7Q== X-Google-Smtp-Source: ABdhPJzde2s6j/g/ekBLPPrgSH2EJqfd3KSDRuhe3Mnzr9w98lVRa6HniOngGCyhNuV4q/eDk1HFvyy/v8IqyEanGTA= X-Received: by 2002:a17:906:1a19:: with SMTP id i25mr9957370ejf.323.1602968492144; Sat, 17 Oct 2020 14:01:32 -0700 (PDT) MIME-Version: 1.0 References: <20201017160928.12698-1-trix@redhat.com> In-Reply-To: <20201017160928.12698-1-trix@redhat.com> From: Dan Williams Date: Sat, 17 Oct 2020 14:01:22 -0700 Message-ID: Subject: Re: [RFC] treewide: cleanup unreachable breaks To: trix@redhat.com Cc: Linux Kernel Mailing List , linux-edac@vger.kernel.org, Linux ACPI , Linux-pm mailing list , xen-devel , linux-block@vger.kernel.org, openipmi-developer@lists.sourceforge.net, linux-crypto , Linux ARM , linux-power@fi.rohmeurope.com, linux-gpio@vger.kernel.org, amd-gfx list , Maling list - DRI developers , 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 , linux-mtd@lists.infradead.org, linux-can@vger.kernel.org, Netdev , intel-wired-lan@lists.osuosl.org, ath10k@lists.infradead.org, Linux Wireless List , linux-stm32@st-md-mailman.stormreply.com, linux-nfc@lists.01.org, linux-nvdimm , Linux PCI , linux-samsung-soc , platform-driver-x86@vger.kernel.org, patches@opensource.cirrus.com, storagedev@microchip.com, devel@driverdev.osuosl.org, linux-serial@vger.kernel.org, USB list , usb-storage@lists.one-eyed-alien.net, linux-watchdog@vger.kernel.org, ocfs2-devel@oss.oracle.com, bpf@vger.kernel.org, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, "open list:KEYS-TRUSTED" , alsa-devel@alsa-project.org, clang-built-linux Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Sat, Oct 17, 2020 at 9:10 AM 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. > > clang has a number of useful, new warnings see > https://clang.llvm.org/docs/DiagnosticsReference.html > > This change cleans up -Wunreachable-code-break > https://clang.llvm.org/docs/DiagnosticsReference.html#wunreachable-code-break > for 266 of 485 warnings in this week's linux-next, allyesconfig on x86_64. > > The method of fixing was to look for warnings where the preceding statement > was a simple statement and by inspection made the subsequent break unneeded. > In order of frequency these look like > > return and break > > switch (c->x86_vendor) { > case X86_VENDOR_INTEL: > intel_p5_mcheck_init(c); > return 1; > - break; > > goto and break > > default: > operation = 0; /* make gcc happy */ > goto fail_response; > - break; > > break and break > case COLOR_SPACE_SRGB: > /* by pass */ > REG_SET(OUTPUT_CSC_CONTROL, 0, > OUTPUT_CSC_GRPH_MODE, 0); > break; > - break; > > The exception to the simple statement, is a switch case with a block > and the end of block is a return > > struct obj_buffer *buff = r->ptr; > return scnprintf(str, PRIV_STR_SIZE, > "size=%u\naddr=0x%X\n", buff->size, > buff->addr); > } > - break; > > Not considered obvious and excluded, breaks after > multi level switches > complicated if-else if-else blocks > panic() or similar calls > > And there is an odd addition of a 'fallthrough' in drivers/tty/nozomi.c [..] > diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c > index 5a7c80053c62..2f250874b1a4 100644 > --- a/drivers/nvdimm/claim.c > +++ b/drivers/nvdimm/claim.c > @@ -200,11 +200,10 @@ ssize_t nd_namespace_store(struct device *dev, > } > break; > default: > len = -EBUSY; > goto out_attach; > - break; > } Acked-by: Dan Williams