Hi Catalin,

On 17/01/2020 11:33, Catalin Marinas wrote:

On Mon, Dec 16, 2019 at 02:17:16PM +0530, Amit Daniel Kachhap wrote:

quoted

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.

Not sure of your experiments for MTE, the kernel is built with clang but uses
the GNU assembler. The -Wa, option is passed down to the assembler (GNU) which
honors it.

Said that, I agree with Masahiro Yamada about the "-c" option to be used in
place of "-E" and on that sense I provided a patch to Amit last December which
should be integrated in the next series (Amit can confirm, I hope ;) ).

-- 
Regards,
Vincenzo