Function hal_pin_alias 

pub unsafe extern "C" fn hal_pin_alias(
    pin_name: *const c_char,
    alias: *const c_char,
) -> c_int

‘hal_pin_alias()’ assigns an alternate name, aka an alias, to a pin. Once assigned, the pin can be referred to by either its original name or the alias. Calling this function with ‘alias’ set to NULL will remove any existing alias.