[PATCH v3 09/22] common/idpf: refactor size check macro

[Burakov, Anatoly]

On 6/12/2024 5:52 AM, Soumyadeep Hore wrote:
> Instead of using 'divide by 0' to check the struct length,
> use the static_assert macro
> 
> Signed-off-by: Soumyadeep Hore <soumyadeep.hore at intel.com>
> ---
>   drivers/common/idpf/base/virtchnl2.h | 13 +++++--------
>   1 file changed, 5 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/common/idpf/base/virtchnl2.h b/drivers/common/idpf/base/virtchnl2.h
> index 1f59730297..f8b97f2e06 100644
> --- a/drivers/common/idpf/base/virtchnl2.h
> +++ b/drivers/common/idpf/base/virtchnl2.h
> @@ -41,15 +41,12 @@
>   /* State Machine error - Command sequence problem */
>   #define	VIRTCHNL2_STATUS_ERR_ESM	201
>   
> -/* These macros are used to generate compilation errors if a structure/union
> - * is not exactly the correct length. It gives a divide by zero error if the
> - * structure/union is not of the correct size, otherwise it creates an enum
> - * that is never used.
> +/* This macro is used to generate compilation errors if a structure
> + * is not exactly the correct length.
>    */
> -#define VIRTCHNL2_CHECK_STRUCT_LEN(n, X) enum virtchnl2_static_assert_enum_##X \
> -	{ virtchnl2_static_assert_##X = (n)/((sizeof(struct X) == (n)) ? 1 : 0) }
> -#define VIRTCHNL2_CHECK_UNION_LEN(n, X) enum virtchnl2_static_asset_enum_##X \
> -	{ virtchnl2_static_assert_##X = (n)/((sizeof(union X) == (n)) ? 1 : 0) }
> +#define VIRTCHNL2_CHECK_STRUCT_LEN(n, X)	\
> +	static_assert((n) == sizeof(struct X),	\
> +		      "Structure length does not match with the expected value")
>   

It appears that the patch also removed CHECK_UNION_LEN macro (presumably 
because it is unused and no longer needed). Would be good to add this to 
commit message.

>   /* New major set of opcodes introduced and so leaving room for
>    * old misc opcodes to be added in future. Also these opcodes may only

-- 
Thanks,
Anatoly