From: Johannes Berg <johannes@sipsolutions.net>
To: Matthias Kaehlcke <mka@chromium.org>,
"David S . Miller" <davem@davemloft.net>
Cc: linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org,
netdev@vger.kernel.org, Grant Grundler <grundler@chromium.org>,
Michael Davidson <md@google.com>,
Greg Hackmann <ghackmann@google.com>
Subject: Re: [PATCH] mac80211: Fix clang warning about constant operand in logical operation
Date: Thu, 06 Apr 2017 21:11:18 +0200 [thread overview]
Message-ID: <1491505878.11399.4.camel@sipsolutions.net> (raw)
In-Reply-To: <20170406185633.91065-1-mka@chromium.org> (sfid-20170406_205658_084798_12B3FAFB)
On Thu, 2017-04-06 at 11:56 -0700, Matthias Kaehlcke wrote:
> Clang raises a warning about the expression 'strlen(CONFIG_XXX)'
> being
> used in a logical operation. Clangs' builtin strlen function resolves
> the
> expression to a constant at compile time, which causes clang to
> generate
> a 'constant-logical-operand' warning.
>
> Split the if statement in two to avoid using the const expression in
> a logical operation.
>
I don't really see all much point in doing this for the warning's
sake... hopefully it doesn't actually generate worse code, but I think
the code ends up looking worse and people will forever wonder what the
goto is really doing there.
johannes
WARNING: multiple messages have this Message-ID (diff)
From: Johannes Berg <johannes-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
To: Matthias Kaehlcke <mka-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
"David S . Miller"
<davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Grant Grundler <grundler-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
Michael Davidson <md-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
Greg Hackmann <ghackmann-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH] mac80211: Fix clang warning about constant operand in logical operation
Date: Thu, 06 Apr 2017 21:11:18 +0200 [thread overview]
Message-ID: <1491505878.11399.4.camel@sipsolutions.net> (raw)
In-Reply-To: <20170406185633.91065-1-mka-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org> (sfid-20170406_205658_084798_12B3FAFB)
On Thu, 2017-04-06 at 11:56 -0700, Matthias Kaehlcke wrote:
> Clang raises a warning about the expression 'strlen(CONFIG_XXX)'
> being
> used in a logical operation. Clangs' builtin strlen function resolves
> the
> expression to a constant at compile time, which causes clang to
> generate
> a 'constant-logical-operand' warning.
>
> Split the if statement in two to avoid using the const expression in
> a logical operation.
>
I don't really see all much point in doing this for the warning's
sake... hopefully it doesn't actually generate worse code, but I think
the code ends up looking worse and people will forever wonder what the
goto is really doing there.
johannes
next prev parent reply other threads:[~2017-04-06 19:11 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-06 18:56 [PATCH] mac80211: Fix clang warning about constant operand in logical operation Matthias Kaehlcke
2017-04-06 18:56 ` Matthias Kaehlcke
2017-04-06 19:11 ` Johannes Berg [this message]
2017-04-06 19:11 ` Johannes Berg
2017-04-06 19:24 ` Matthias Kaehlcke
2017-04-06 21:12 ` Johannes Berg
2017-04-06 21:12 ` Johannes Berg
2017-04-06 22:42 ` Matthias Kaehlcke
2017-04-06 22:51 ` Johannes Berg
2017-04-06 23:07 ` Matthias Kaehlcke
2017-04-10 14:12 ` David Laight
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=1491505878.11399.4.camel@sipsolutions.net \
--to=johannes@sipsolutions.net \
--cc=davem@davemloft.net \
--cc=ghackmann@google.com \
--cc=grundler@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-wireless@vger.kernel.org \
--cc=md@google.com \
--cc=mka@chromium.org \
--cc=netdev@vger.kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.