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Date: Fri, 17 Jan 2020 11:33:51 +0000
From: Catalin Marinas <catalin.marinas@arm.com>
Subject: Re: [PATCH v3 14/16] kconfig: Add support for 'as-option'
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References: <1576486038-9899-1-git-send-email-amit.kachhap@arm.com>
 <1576486038-9899-15-git-send-email-amit.kachhap@arm.com>
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To: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: linux-arm-kernel@lists.infradead.org, Mark Rutland <mark.rutland@arm.com>, Kees Cook <keescook@chromium.org>, Ard Biesheuvel <ard.biesheuvel@linaro.org>, Suzuki K Poulose <suzuki.poulose@arm.com>, Will Deacon <will@kernel.org>, Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>, Kristina Martsenko <kristina.martsenko@arm.com>, Dave Martin <Dave.Martin@arm.com>, James Morse <james.morse@arm.com>, Vincenzo Frascino <Vincenzo.Frascino@arm.com>, Mark Brown <Mark.Brown@arm.com>, Richard Henderson <richard.henderson@linaro.org>, Masahiro Yamada <yamada.masahiro@socionext.com>, linux-kbuild@vger.kernel.org

On Mon, Dec 16, 2019 at 02:17:16PM +0530, Amit Daniel Kachhap wrote:
> diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include
> index d4adfbe..cc465dd 100644
> --- a/scripts/Kconfig.include
> +++ b/scripts/Kconfig.include
> @@ -31,6 +31,10 @@ cc-option = $(success,$(CC) -Werror $(CLANG_FLAGS) $(1) -E -x c /dev/null -o /de
>  # Return y if the linker supports <flag>, n otherwise
>  ld-option = $(success,$(LD) -v $(1))
>  
> +# $(as-option,<flag>)
> +# Return y if the assembler supports <flag>, n otherwise
> +as-option = $(success, $(CC) $(CLANG_FLAGS) $(1) -E -x assembler /dev/null -o /dev/null)

I had different experiments with this for MTE and noticed that clang
does not honour the -Wa, option (which you use in a subsequent patch).
So not sure how useful as-option is.

-- 
Catalin