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From:   Ricardo Ribalda <ribalda@chromium.org>
Date:   Wed, 9 Jun 2021 16:15:55 +0200
Message-ID: <CANiDSCtYr3R79XPnFvMfLZYj=sTWGq+neHqrdNwXDN6JB25aMA@mail.gmail.com>
Subject: Re: [PATCH] tools/perf: Do not set a variable unless it will be used
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-perf-users@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>
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Hi Peter

On Tue, 8 Jun 2021 at 13:29, Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Fri, Jun 04, 2021 at 09:24:23PM +0200, Ricardo Ribalda wrote:
> > Hi Peter
> >
> > On Fri, 4 Jun 2021 at 11:36, Peter Zijlstra <peterz@infradead.org> wrote:
> > >
> > > On Fri, Jun 04, 2021 at 11:26:38AM +0200, Ricardo Ribalda wrote:
> > > > clang-13 triggers the following warning:
> > > >
> > > > bench/inject-buildid.c:351:6: error: variable 'len' set but not used [-Werror,-Wunused-but-set-variable]
>                                                                          clue here: ^^^^^^^^^^^^^
>
> > > >         u64 len = 0;
> > > >
> > > > This patch sets the value to len only if it will be used afterwards.
> > >
> > > My vote would be to kill that warning, what absolute shite.
> >
> > My knowledge of llvm codebase is close to NULL, so it is much easier
> > for me to "fix" the code.
>
> That's what -Wno-unused-but-set-variable is for, which is trivial to add
> to the Makefile.

Yes, that is quite easy to add, the problem is that we might hide real
bugs.  I completely agree that this one is borderline :)


-- 
Ricardo Ribalda