macro IsUsed(symbol){    var search_buf;    var search_count;    var link_recrod;    var link_buf;    var ref_sym;    var is_used;        var i;    is_used = False;    if (symbol == Nil) {        return is_used;    }    search_buf = NewBuf("Search");    if (search_buf == hNil) {        Msg("new buf failed.");        stop;    }    SearchForRefs(search_buf, symbol, False);    search_count = GetBufLineCount(search_buf);    i = 0;    while (i < search_count) {        link_recrod = GetSourceLink(search_buf, i);        i = i + 1;        if (link_recrod == Nil) {            continue;        }        link_buf = OpenBuf(link_recrod.File);        ref_sym = GetSymbolLocationFromLn(link_buf, link_recrod.ln);        // CloseBuf(link_buf);        if (ref_sym == Nil) {            continue;        }        // Msg(ref_sym.Symbol # " " # ref_sym.File # " " # ref_sym.lnFirst);        if (ref_sym.Symbol != symbol) {            is_used = True;            break;        }    }    CloseBuf(search_buf);    return is_used;}macro CheckIsUsed(){    var data_file_name;    var data_file_buf;    var data_file_count;    var data_file_line;    var used_record_buf;    var used_record_name;    var i;    var is_used;       data_file_name = "Data.txt";    used_record_name = "used_record.txt";    used_record_buf = NewBuf(used_record_name);    SetCurrentBuf(used_record_buf);    data_file_buf = OpenBuf(data_file_name);    data_file_count = GetBufLineCount(data_file_buf);    i = 0;    while (i < data_file_count) {        data_file_line = GetBufLine(data_file_buf, i);        i = i + 1;        is_used = IsUsed(data_file_line);        AppendBufLine(used_record_buf, data_file_line # "," # is_used);    }}