Macro kfuncs 

macro_rules! kfuncs {
    ($( $(#[$attr:ident])* fn $name:ident ( $($param:ident : $type:ident),* ) $(-> $ret:ident)? ; )*) => { ... };
}

Expand a kfunc catalog, see scx_rustsched’s kfuncs.rs, into a kfuncs() function listing it for Spec.