eval.c:141
void
rb_secure(level)
    int level;
{
    if (level <= ruby_safe_level) {
	if (ruby_frame->last_func) {
	    rb_raise(rb_eSecurityError, "Insecure operation `%s' at level %d",
		     rb_id2name(ruby_frame->last_func), ruby_safe_level);
	}
	else {
	    rb_raise(rb_eSecurityError, "Insecure operation at level %d", ruby_safe_level);
	}
    }
}
