int diff_setup_done(struct diff_options *options)
 {
+       int count = 0;
+
+       if (options->output_format & DIFF_FORMAT_NAME)
+               count++;
+       if (options->output_format & DIFF_FORMAT_NAME_STATUS)
+               count++;
+       if (options->output_format & DIFF_FORMAT_CHECKDIFF)
+               count++;
+       if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
+               count++;
+       if (count > 1)
+               die("--name-only, --name-status, --check and -s are mutually exclusive");
+
        if ((options->find_copies_harder &&
             options->detect_rename != DIFF_DETECT_COPY) ||
            (0 <= options->rename_limit && !options->detect_rename))