RDS_INFO_LAST
case RDS_INFO_FIRST ... RDS_INFO_LAST:
static rds_info_func rds_info_funcs[RDS_INFO_LAST - RDS_INFO_FIRST + 1];
BUG_ON(optname < RDS_INFO_FIRST || optname > RDS_INFO_LAST);
BUG_ON(optname < RDS_INFO_FIRST || optname > RDS_INFO_LAST);