+static const char diff_status_letters[] = {
+ DIFF_STATUS_ADDED,
+ DIFF_STATUS_COPIED,
+ DIFF_STATUS_DELETED,
+ DIFF_STATUS_MODIFIED,
+ DIFF_STATUS_RENAMED,
+ DIFF_STATUS_TYPE_CHANGED,
+ DIFF_STATUS_UNKNOWN,
+ DIFF_STATUS_UNMERGED,
+ DIFF_STATUS_FILTER_AON,
+ DIFF_STATUS_FILTER_BROKEN,
+ '\0',
+};
+
+static unsigned int filter_bit['Z' + 1];
+
+static void prepare_filter_bits(void)
+{
+ int i;
+
+ if (!filter_bit[DIFF_STATUS_ADDED]) {
+ for (i = 0; diff_status_letters[i]; i++)
+ filter_bit[(int) diff_status_letters[i]] = (1 << i);
+ }
+}
+
+static unsigned filter_bit_tst(char status, const struct diff_options *opt)
+{
+ return opt->filter & filter_bit[(int) status];
+}
+
+static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
+{
+ int i, optch;
+
+ prepare_filter_bits();
+ for (i = 0; (optch = optarg[i]) != '\0'; i++) {
+ unsigned int bit;
+
+ bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
+ if (!bit)
+ continue; /* ignore unknown ones, like we always have */
+ opt->filter |= bit;
+ }
+ return 0;
+}
+