From: Harshitha Ramamurthy Date: Tue, 23 Jan 2018 16:51:03 +0000 (-0800) Subject: virtchnl: Add a macro to check the size of a union X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=0718e560a330599d15fddc37651d693c7a09e49e;p=openwrt%2Fstaging%2Fblogic.git virtchnl: Add a macro to check the size of a union This patch adds a macro to check if the size of a union is correct. It throws a divide by zero error if the union is not of the correct size. Signed-off-by: Harshitha Ramamurthy Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- diff --git a/include/linux/avf/virtchnl.h b/include/linux/avf/virtchnl.h index 1f652ceecf35..6fe630ebbf23 100644 --- a/include/linux/avf/virtchnl.h +++ b/include/linux/avf/virtchnl.h @@ -140,13 +140,15 @@ enum virtchnl_ops { VIRTCHNL_OP_DISABLE_CHANNELS = 31, }; -/* This macro is used to generate a compilation error if a structure +/* 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 is not of the correct size, otherwise it creates an enum that is - * never used. + * structure/union is not of the correct size, otherwise it creates an enum + * that is never used. */ #define VIRTCHNL_CHECK_STRUCT_LEN(n, X) enum virtchnl_static_assert_enum_##X \ { virtchnl_static_assert_##X = (n)/((sizeof(struct X) == (n)) ? 1 : 0) } +#define VIRTCHNL_CHECK_UNION_LEN(n, X) enum virtchnl_static_asset_enum_##X \ + { virtchnl_static_assert_##X = (n)/((sizeof(union X) == (n)) ? 1 : 0) } /* Virtual channel message descriptor. This overlays the admin queue * descriptor. All other data is passed in external buffers.