linux-acpi.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Dan Williams <dan.j.williams@intel.com>
To: trix@redhat.com
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-edac@vger.kernel.org,
	Linux ACPI <linux-acpi@vger.kernel.org>,
	Linux-pm mailing list <linux-pm@vger.kernel.org>,
	xen-devel <xen-devel@lists.xenproject.org>,
	linux-block@vger.kernel.org,
	openipmi-developer@lists.sourceforge.net,
	linux-crypto <linux-crypto@vger.kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	linux-power@fi.rohmeurope.com, linux-gpio@vger.kernel.org,
	amd-gfx list <amd-gfx@lists.freedesktop.org>,
	Maling list - DRI developers  <dri-devel@lists.freedesktop.org>,
	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" <linux-media@vger.kernel.org>,
	MPT-FusionLinux.pdl@broadcom.com,
	linux-scsi <linux-scsi@vger.kernel.org>,
	linux-mtd@lists.infradead.org, linux-can@vger.kernel.org,
	Netdev <netdev@vger.kernel.org>,
	intel-wired-lan@lists.osuosl.org, ath10k@lists.infradead.org,
	Linux Wireless List <linux-wireless@vger.kernel.org>,
	linux-stm32@st-md-mailman.stormreply.com, linux-nfc@lists.01.org,
	linux-nvdimm <linux-nvdimm@lists.01.org>,
	Linux PCI <linux-pci@vger.kernel.org>,
	linux-samsung-soc <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,
	USB list <linux-usb@vger.kernel.org>,
	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" <keyrings@vger.kernel.org>,
	alsa-devel@alsa-project.org,
	clang-built-linux <clang-built-linux@googlegroups.com>
Subject: Re: [RFC] treewide: cleanup unreachable breaks
Date: Sat, 17 Oct 2020 14:01:22 -0700	[thread overview]
Message-ID: <CAPcyv4jkSFxMXgMABX7sDbwmq8zJO=rLX2ww3Y9Tc0VAANY8xQ@mail.gmail.com> (raw)
In-Reply-To: <20201017160928.12698-1-trix@redhat.com>

On Sat, Oct 17, 2020 at 9:10 AM <trix@redhat.com> wrote:
>
> From: Tom Rix <trix@redhat.com>
>
> 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 <dan.j.williams@intel.com>

  parent reply	other threads:[~2020-10-17 21:01 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-17 16:09 [RFC] treewide: cleanup unreachable breaks trix
2020-10-17 16:24 ` Joe Perches
2020-10-17 18:21   ` [Cocci] " Julia Lawall
2020-10-17 19:00     ` Joe Perches
2020-10-17 21:01 ` Dan Williams [this message]
2020-10-18  5:43 ` Greg KH
2020-10-18 14:04   ` Tom Rix
2020-10-19 19:42   ` Nick Desaulniers
2020-10-19 23:05     ` Jason Gunthorpe
2020-10-20 14:09       ` Tom Rix
2020-10-20  8:47     ` [Ocfs2-devel] " John Haxby
2020-10-20 13:55     ` Tom Rix
2020-10-20 18:42     ` Joe Perches
2020-10-18  9:29 ` Hans de Goede
2020-10-18 18:59 ` [Ocfs2-devel] " Matthew Wilcox
2020-10-18 19:06   ` Joe Perches
2020-10-18 19:13   ` James Bottomley
2020-10-18 19:16     ` Matthew Wilcox
2020-10-18 19:17       ` James Bottomley

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAPcyv4jkSFxMXgMABX7sDbwmq8zJO=rLX2ww3Y9Tc0VAANY8xQ@mail.gmail.com' \
    --to=dan.j.williams@intel.com \
    --cc=MPT-FusionLinux.pdl@broadcom.com \
    --cc=alsa-devel@alsa-project.org \
    --cc=amd-gfx@lists.freedesktop.org \
    --cc=ath10k@lists.infradead.org \
    --cc=bpf@vger.kernel.org \
    --cc=clang-built-linux@googlegroups.com \
    --cc=devel@driverdev.osuosl.org \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=industrypack-devel@lists.sourceforge.net \
    --cc=intel-wired-lan@lists.osuosl.org \
    --cc=keyrings@vger.kernel.org \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-amlogic@lists.infradead.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-can@vger.kernel.org \
    --cc=linux-crypto@vger.kernel.org \
    --cc=linux-edac@vger.kernel.org \
    --cc=linux-gpio@vger.kernel.org \
    --cc=linux-iio@vger.kernel.org \
    --cc=linux-integrity@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=linux-mtd@lists.infradead.org \
    --cc=linux-nfc@lists.01.org \
    --cc=linux-nvdimm@lists.01.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=linux-power@fi.rohmeurope.com \
    --cc=linux-samsung-soc@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    --cc=linux-stm32@st-md-mailman.stormreply.com \
    --cc=linux-usb@vger.kernel.org \
    --cc=linux-watchdog@vger.kernel.org \
    --cc=linux-wireless@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=nouveau@lists.freedesktop.org \
    --cc=ocfs2-devel@oss.oracle.com \
    --cc=openipmi-developer@lists.sourceforge.net \
    --cc=patches@opensource.cirrus.com \
    --cc=platform-driver-x86@vger.kernel.org \
    --cc=spice-devel@lists.freedesktop.org \
    --cc=storagedev@microchip.com \
    --cc=trix@redhat.com \
    --cc=usb-storage@lists.one-eyed-alien.net \
    --cc=virtualization@lists.linux-foundation.org \
    --cc=xen-devel@lists.xenproject.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).