def enum_func_name_call_indirect(functions):
    """ return a list of function name if they used call_indirect
    """
    func_name = list()
    for func in functions:
        for inst in func.instructions:
            if inst.name == 'call_indirect':
                func_name.append(func.name)
    func_name = list(set(func_name))
    return func_name
