}
}

func TestUnreadRune(t *testing.T) {
	segments := []string{"Hello, world:", "日本語"}
	r := NewReader(&StringReader{data: segments})
	got := ""
	want := strings.Join(segments, "")
	// Normal execution.
	for {
		r1, _, err := r.ReadRune()
		if err != nil {
			if err != io.EOF {
				t.Error("unexpected error on ReadRune:", err)
			}
			break
		}
		got += string(r1)

		notIntConst
		notNumConst
		notStrLiteral
		notDeclared
	)
	sawUnmatchedErrors := false
	for _, line := range strings.Split(stderr, "\n") {
		// Ignore warnings and random comments, with one
		// exception: newer GCC versions will sometimes emit
		// an error on a macro #define with a note referring
		// to where the expansion occurs. We care about where
		// the expansion occurs, so in that case treat the note