Re: [XEN PATCH v2 09/13] xen/public: fix violations of MISRA C:2012 Rule 7.2

[Juergen Gross <jgross@xxxxxxxx>]

On 05.07.23 17:26, Simone Ballarin wrote:
> From: Gianluca Luparini <gianluca.luparini@xxxxxxxxxxx>
>
> The xen sources contains violations of MISRA C:2012 Rule 7.2 whose
> headline states:
> "A 'u' or 'U' suffix shall be applied to all integer constants
> that are represented in an unsigned type".
>
> Add the 'U' suffix to integers literals with unsigned type and also to other
> literals used in the same contexts or near violations, when their positive
> nature is immediately clear. The latter changes are done for the sake of
> uniformity.
>
> Signed-off-by: Simone Ballarin <simone.ballarin@xxxxxxxxxxx>
> Signed-off-by: Gianluca Luparini <gianluca.luparini@xxxxxxxxxxx>
> ---
> Changes in v2:
> - minor change to commit title
> - change commit message
> - correct macros code style
> ---
>   xen/include/public/io/ring.h | 10 +++++-----
>   1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/xen/include/public/io/ring.h b/xen/include/public/io/ring.h
> index 025939278b..0cae4367be 100644
> --- a/xen/include/public/io/ring.h
> +++ b/xen/include/public/io/ring.h
> @@ -36,11 +36,11 @@
>   typedef unsigned int RING_IDX;
>   
>   /* Round a 32-bit unsigned constant down to the nearest power of two. */
> -#define __RD2(_x)  (((_x) & 0x00000002) ? 0x2                  : ((_x) & 0x1))
> -#define __RD4(_x)  (((_x) & 0x0000000c) ? __RD2((_x)>>2)<<2    : __RD2(_x))
> -#define __RD8(_x)  (((_x) & 0x000000f0) ? __RD4((_x)>>4)<<4    : __RD4(_x))
> -#define __RD16(_x) (((_x) & 0x0000ff00) ? __RD8((_x)>>8)<<8    : __RD8(_x))
> -#define __RD32(_x) (((_x) & 0xffff0000) ? __RD16((_x)>>16)<<16 : __RD16(_x))
> +#define __RD2(x)  (((x) & 0x00000002U) ? 0x2                     : ((x) & 0x1))
Shouldn't this be rather:

+#define __RD2(x)  (((x) & 0x00000002U) ? 0x2U                   : ((x) & 0x1U))

> +#define __RD4(x)  (((x) & 0x0000000cU) ? __RD2((x) >> 2) << 2    : __RD2(x))
> +#define __RD8(x)  (((x) & 0x000000f0U) ? __RD4((x) >> 4) << 4    : __RD4(x))
> +#define __RD16(x) (((x) & 0x0000ff00U) ? __RD8((x) >> 8) << 8    : __RD8(x))
> +#define __RD32(x) (((x) & 0xffff0000U) ? __RD16((x) >> 16) << 16 : __RD16(x))
>   
>   /*
>    * Calculate size of a shared ring, given the total available space for the
Other than that:

Reviewed-by: Juergen Gross <jgross@xxxxxxxx>


Juergen

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