Hi.
On Mon, Feb 17, 2020 at 6:29 PM Amit Daniel Kachhap
<amit.kachhap@xxxxxxx> wrote:
>
> From: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
>
> Currently kconfig does not have a feature that allows to detect if the
> used assembler supports a specific compilation option.
>
> Introduce 'as-option' to serve this purpose in the context of Kconfig:
>
> config X
> def_bool $(as-option,...)
>
> Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> Cc: linux-kbuild@xxxxxxxxxxxxxxx
> Acked-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxx>
> ---
> scripts/Kconfig.include | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include
> index 85334dc..374e251 100644
> --- a/scripts/Kconfig.include
> +++ b/scripts/Kconfig.include
> @@ -35,6 +35,10 @@ ld-option = $(success,$(LD) -v $(1))
> # Return y if the assembler supports <instr>, n otherwise
> as-instr = $(success,printf "%b\n" "$(1)" | $(CC) $(CLANG_FLAGS) -c -x assembler -o /dev/null -)
>
> +# $(as-option,<flag>)
> +# Return y if the assembler supports <flag>, n otherwise
> +as-option =$(success, $(CC) $(CLANG_FLAGS) $(1) -c -x assembler /dev/null -o /dev/zero)
> +
I am still not convinced with using /dev/zero here.
Does this work?
as-option = $(success, cat /dev/null | $(CC) $(CLANG_FLAGS) $(1) -c -x
assembler -o /dev/null -)
[1] Could you insert as-option between ld-option and as-instr ?
[2] Could you add some comments to explain why
/dev/null -o /dev/null does not work?
> # check if $(CC) and $(LD) exist
> $(error-if,$(failure,command -v $(CC)),compiler '$(CC)' not found)
> $(error-if,$(failure,command -v $(LD)),linker '$(LD)' not found)
> --
> 2.7.4
>
--
Best Regards
Masahiro Yamada
