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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Wed, 28 Aug 2019 16:10:15 -0700
Message-ID: <CAKwvOdkOo-6aS=Tu_QkArHK=rhK34Qe+SKJtY4sM-7YupAsCNA@mail.gmail.com>
Subject: Re: [PATCH v2] kbuild: enable unused-function warnings for W= build
 with Clang
To:     Masahiro Yamada <yamada.masahiro@socionext.com>
Cc:     Nathan Chancellor <natechancellor@gmail.com>,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Michal Marek <michal.lkml@markovi.net>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        LKML <linux-kernel@vger.kernel.org>
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On Tue, Aug 27, 2019 at 7:58 PM Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> On Wed, Aug 28, 2019 at 6:56 AM Nick Desaulniers
> <ndesaulniers@google.com> wrote:
> > Masahiro, does your patch correctly make -Wunused-function work for
> > clang at W=1?  It looks like -Wunused gets added to warning-1, but
> > then -Wno-unused-function gets added to KBUILD_CFLAGS after `warning`
> > does.  Will that work correctly?  I'd imagine that at W=1,
> > KBUILD_CFLAGS for clang will look like:
> > ... -Wunused -Wno-unused-function ...
> > which is probably not what we want?
>
> Hmm?
>
> -Wunused is added only when W=1.
>
> -Wno-unused-function is added only when W= was not passed.
>
> They do not happen at the same time.

Acked-by: Nick Desaulniers <ndesaulniers@google.com>

-- 
Thanks,
~Nick Desaulniers