Re: [XEN PATCH 01/11] x86/efi: move variable declaration to address MISRA C:2012 Rule 2.1

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Wed, 2 Aug 2023, Nicola Vetrini wrote:
> The variable declaration is moved where it's actually used, rather
> than being declared in the switch before any clause, thus being
> classified as unreachable code.
> 
> No functional changes.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
> ---
>  xen/arch/x86/efi/efi-boot.h | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h
> index 92f4cfe8bd..b00441b1a2 100644
> --- a/xen/arch/x86/efi/efi-boot.h
> +++ b/xen/arch/x86/efi/efi-boot.h
> @@ -390,8 +390,6 @@ static void __init efi_arch_edd(void)
>          {
>              switch ( DevicePathType(devp.DevPath) )
>              {
> -                const u8 *p;
> -
>              case ACPI_DEVICE_PATH:
>                  if ( state != root || boot_edd_info_nr > EDD_INFO_MAX )
>                      break;
> @@ -463,7 +461,8 @@ static void __init efi_arch_edd(void)
>                  params->device_path_info_length =
>                      sizeof(struct edd_device_params) -
>                      offsetof(struct edd_device_params, key);
> -                for ( p = (const u8 *)&params->key; p < &params->checksum; 
> ++p )
> +                for ( const u8 *p = (const u8 *)&params->key;
> +                      p < &params->checksum; ++p )

In Xen we don't mix declaration and code. So the following is not
something we use:

  for (int i = 0; i < 10; i++)

I think you'd have to introduce another block under case
MESSAGING_DEVICE_PATH so that you can moved const u8 *p there


>                      params->checksum -= *p;
>                  break;
>              case MEDIA_DEVICE_PATH:
> -- 
> 2.34.1
>