[PATCH RFC next 15/18] kbuild: enable -Werror for hostprogs

[Simon Glass]

Hi Quentin,

On 2026-05-04T13:20:27, Quentin Schulz <foss+uboot at 0leil.net> wrote:
> kbuild: enable -Werror for hostprogs
>
> [ Upstream commit 27758d8c2583d10472b745a43ff86fef96c11ef7 ]
>
> Original commit log:
>
>   The hostprog compilers and linkers do not share the regular compiler flags,
>   so they are not affected by CONFIG_WERROR or W=e. As hostprogs are used
>   during the bootstrap of the build, they can't depend on kconfig options.
>
>   Enable -Werror unconditionally.
>
> Signed-off-by: Quentin Schulz <quentin.schulz at cherry.de>
>
> scripts/Makefile.extrawarn | 5 +++++
>  1 file changed, 5 insertions(+)

> diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
> @@ -109,3 +109,8 @@ KBUILD_LDFLAGS            += --fatal-warnings
>  KBUILD_RUSTFLAGS     += -Dwarnings
>
>  endif
> +
> +# Hostprog flags are used during build bootstrapping and can not rely on CONFIG_ symbols.
> +KBUILD_HOSTCFLAGS    += -Werror
> +KBUILD_HOSTLDFLAGS   += -Wl,--fatal-warnings
> +KBUILD_HOSTRUSTFLAGS += -Dwarnings

Just to check, is there a reason to keep this and patch 16 separate?
The next patch immediately undoes the 'unconditionally' claim made
here. Anyone bisecting through this point gets host tools failing on
any new compiler warning, with no way to opt out short of
HOSTCFLAGS=-Wno-error - squashing would also let you drop the comment
that patch 16 then has to rewrite.

If you'd rather keep them split to preserve upstream history, you
could mention in the commit message that the next patch makes it
conditional.

Reviewed-by: Simon Glass <sjg at chromium.org>

Regards,
Simon