Re: [PATCH v1] kbuild: Fix CC_CAN_LINK detection

[Thomas Weißschuh]

On Thu, Feb 12, 2026 at 02:35:43PM +0100, Mickaël Salaün wrote:
> Most samples cannot be build on some environments because they depend
> on CC_CAN_LINK, which is set according to the result of
> scripts/cc-can-link.sh called by cc_can_link_user.
> 
> Because cc-can-link.sh must now build without warning, it may fail
> because it is calling printf() with an empty string:
> 
>   + cat
>   + gcc -m32 -Werror -Wl,--fatal-warnings -x c - -o /dev/null
>   <stdin>: In function ‘main’:
>   <stdin>:4:9: error: zero-length gnu_printf format string [-Werror=format-zero-length]
>   cc1: all warnings being treated as errors
> 
> Fix this warning and the samples build by actually printing something.
> 
> Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
> Cc: Nicolas Schier <nsc@xxxxxxxxxx>
> Cc: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: d81d9d389b9b ("kbuild: don't enable CC_CAN_LINK if the dummy program generates warnings")

Thanks!

Reviewed-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>

In my GCC 15.2 this warning is not enabled by default.

> Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx>
> ---
>  scripts/cc-can-link.sh | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/scripts/cc-can-link.sh b/scripts/cc-can-link.sh
> index e67fd8d7b684..58dc7dd6d556 100755
> --- a/scripts/cc-can-link.sh
> +++ b/scripts/cc-can-link.sh
> @@ -5,7 +5,7 @@ cat << "END" | $@ -Werror -Wl,--fatal-warnings -x c - -o /dev/null >/dev/null 2>
>  #include <stdio.h>
>  int main(void)
>  {
> -	printf("");
> +	printf("\n");
>  	return 0;
>  }
>  END
> -- 
> 2.53.0
>