Re: [PATCH 2/2] Makefile.extrawarn: limit -Wnested-externs to clang

From: Masahiro Yamada
Date: Mon Nov 23 2020 - 07:01:41 EST


On Tue, Oct 27, 2020 at 1:32 PM Nathan Chancellor
<natechancellor@xxxxxxxxx> wrote:
>
> On Mon, Oct 26, 2020 at 06:48:46PM -0700, Nathan Chancellor wrote:
> > On Mon, Oct 26, 2020 at 11:03:14PM +0100, Arnd Bergmann wrote:
> > > From: Arnd Bergmann <arnd@xxxxxxxx>
> > >
> > > The -Wnested-externs warning has become useless with gcc, since
> > > this warns every time that BUILD_BUG_ON() or similar macros
> > > are used.
> > >
> > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> >
> > Also see:
> >
> > 2486baae2cf6 ("objtool: Allow nested externs to enable BUILD_BUG()")
> > 6cf4ecf5c51d ("perf build: Allow nested externs to enable BUILD_BUG() usage")
> >
> > Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
>
> Actually, just delete this line altogether. -Wnested-externs is a GCC
> only warning, the flag is only present in clang for compatibility with
> GCC:
>
> https://clang.llvm.org/docs/DiagnosticsReference.html#wnested-externs
>
> With that, my reviewed by still stands.
>

I agree.



Arnd, will you send v2?

Please include
https://clang.llvm.org/docs/DiagnosticsReference.html#wnested-externs
as a reference.

Thanks.

--
Best Regards
Masahiro Yamada