Re: [PATCH] [v2] Kbuild: move to -std=gnu11

[Masahiro Yamada <masahiroy@kernel.org>]

On Mon, Feb 28, 2022 at 7:32 PM Arnd Bergmann <arnd@kernel.org> wrote:
>
> From: Arnd Bergmann <arnd@arndb.de>
>
> During a patch discussion, Linus brought up the option of changing
> the C standard version from gnu89 to gnu99, which allows using variable
> declaration inside of a for() loop. While the C99, C11 and later standards
> introduce many other features, most of these are already available in
> gnu89 as GNU extensions as well.
>
> An earlier attempt to do this when gcc-5 started defaulting to
> -std=gnu11 failed because at the time that caused warnings about
> designated initializers with older compilers. Now that gcc-5.1 is the
> minimum compiler version used for building kernels, that is no longer a
> concern. Similarly, the behavior of 'inline' functions changes between
> gnu89 and gnu11, but this was taken care of by defining 'inline' to
> include __attribute__((gnu_inline)) in order to allow building with
> clang a while ago.
>
> One minor issue that remains is an added gcc warning for shifts of
> negative integers when building with -Werror, which happens with the

Is this a typo?

   building with -Werror, ...
->
   building with -Wextra, ...




> 'make W=1' option, as well as for three drivers in the kernel that always
> enable -Werror, but it was only observed with the i915 driver so far.

Same here.

   enable -Werror, but ...
->
  enable -Wextra, but ...




Otherwise,

Acked-by: Masahiro Yamada <masahiroy@kernel.org>


Please let me know if you want me to pick up this.









--
Best Regards

Masahiro Yamada