Re: [PATCH] kbuild: Add '-fms-extensions' to areas with dedicated CFLAGS

Christian Brauner
2025-11-05T12:56:11Z

On Sat, Nov 01, 2025 at 12:35:47PM -0400, Nathan Chancellor wrote:
> This is a follow up to commit c4781dc3d1cf ("Kbuild: enable
> -fms-extensions") but in a separate change due to being substantially
> different from the initial submission.
>
> There are many places within the kernel that use their own CFLAGS
> instead of the main KBUILD_CFLAGS, meaning code written with the main
> kernel's use of '-fms-extensions' in mind that may be tangentially
> included in these areas will result in "error: declaration does not
> declare anything" messages from the compiler.
>
> Add '-fms-extensions' to all these areas to ensure consistency, along
> with -Wno-microsoft-anon-tag to silence clang's warning about use of the
> extension that the kernel cares about using. parisc does not build with
> clang so it does not need this warning flag. LoongArch does not need it
> either because -W flags from KBUILD_FLAGS are pulled into cflags-vdso.
>
> Reported-by: Christian Brauner <brauner@kernel.org>
> Closes: https://lore.kernel.org/20251030-meerjungfrau-getrocknet-7b46eacc215d@brauner/
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> ---
> I am taking the original '-fms-extensions' change [1] via a shared
> branch in kbuild [2] so I would appreciate acks. I plan to finalize that
> branch so that other maintainers can safely pull it on Thursday.
>
> [1]: https://git.kernel.org/kbuild/c/c4781dc3d1cf0e017e1f290607ddc56cfe187afc
> [2]: https://git.kernel.org/kbuild/l/kbuild-ms-extensions
> ---

I'll give my ack:

Reviewed-by: Christian Brauner <brauner@kernel.org>

but don't invalidate the branch just to add my RvB if you've already had
it stable.