Re: [PATCH v2 3/3] clang: don't define nocall

[Julien Grall <julien@xxxxxxx>]

Hi Roger,

On 28/05/2020 15:40, Roger Pau Monne wrote:
> Clang doesn't support attribute error, and the possible equivalents
> like diagnose_if don't seem to work well in this case as they trigger
> when when the function is not called (just by being used by the
> APPEND_CALL macro).
OOI, could you share the diagnose_if change you tried?

> Define nocall to a noop on clang until a proper solution can be found.
>
> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
Acked-by: Julien Grall <jgrall@xxxxxxxxxx>

> ---
>   xen/include/xen/compiler.h | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/xen/include/xen/compiler.h b/xen/include/xen/compiler.h
> index c22439b7a4..225e09e5f7 100644
> --- a/xen/include/xen/compiler.h
> +++ b/xen/include/xen/compiler.h
> @@ -20,7 +20,11 @@
>   
>   #define __weak        __attribute__((__weak__))
>   
> -#define nocall        __attribute__((error("Nonstandard ABI")))
> +#if !defined(__clang__)
> +# define nocall        __attribute__((error("Nonstandard ABI")))
> +#else
> +# define nocall
> +#endif
>   
>   #if (!defined(__clang__) && (__GNUC__ == 4) && (__GNUC_MINOR__ < 5))
>   #define unreachable() do {} while (1)
Cheers,

--
Julien Grall