Re: [PATCH 1/3] kbuild: Add cc-option-no-kbuild macro

[Michal Marek <mmarek@suse.com>]

On 2017-06-13 02:55, Matthias Kaehlcke wrote:
> cc-option uses KBUILD_CFLAGS and KBUILD_CPPFLAGS when it determines
> whether an option is supported or not. This is fine for options used to
> build the kernel itself, however some components like the x86 boot code
> use a different set of flags.
> 
> Add the new macro cc-option-no-kbuild which does the same as cc-option
> except that it has an additional parameter with the compiler options
> which are used instead of KBUILD_CFLAGS and KBUILD_CPPFLAGS.
> 
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> ---
>  scripts/Kbuild.include | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
> index 61f87a99bf0a..d9fdc740105f 100644
> --- a/scripts/Kbuild.include
> +++ b/scripts/Kbuild.include
> @@ -128,6 +128,11 @@ cc-option-yn = $(call try-run,\
>  cc-option-align = $(subst -functions=0,,\
>  	$(call cc-option,-falign-functions=0,-malign-functions=0))
>  
> +# cc-option-no-kbuild
> +# Usage: cflags-no-kbuild-y += $(call cc-option-no-kbuild,<other flags>,-march=winchip-c6,-march=i586)
> +cc-option-no-kbuild = $(call try-run,\
> +	$(CC) -Werror $(filter-out $(GCC_PLUGINS_CFLAGS),$(1)) $(2) -c -x c /dev/null -o "$$TMP",$(2),$(3))

As this is a version of cc-option with an extrra argument, how about
implementing cc-option as a shorthand for cc-option-no-kbuild? It would
make it more obvious what cc-option-no-kbuild does differently (it's
probably just me, but I was unable to infer the semantics from its name).

Michal