macro_rules! m {
    ($a:expr $(tok $es:expr)*) => {
        // { dg-error "token .identifier. is not allowed after .expr. fragment" "" { target *-*-* } .-1 }
        // { dg-error "required first macro rule in macro rules definition could not be parsed" "" { target *-*-* } .-2 }
        // { dg-error "failed to parse item in crate" "" { target *-*-* } .-3 }
        $a
    };
}