void currentSql(HplsqlParser.Expr_spec_funcContext ctx) {
    if (ctx.T_DATE() != null) {
      if (exec.getConnectionType() == Conn.Type.HIVE) {
        evalSqlString("TO_DATE(FROM_UNIXTIME(UNIX_TIMESTAMP()))");
      } 
      else {
        evalSqlString("CURRENT_DATE");
      }
    }
    else if (ctx.T_TIMESTAMP() != null) {
      if (exec.getConnectionType() == Conn.Type.HIVE) {
        evalSqlString("FROM_UNIXTIME(UNIX_TIMESTAMP())");
      } 
      else {
        evalSqlString("CURRENT_TIMESTAMP");
      }
    } else if (ctx.T_USER() != null) {
      evalSqlString("CURRENT_USER()");
    } else {
      evalSqlString(exec.getFormattedText(ctx));
    }
  }
CURRENT <VALUE> function in executable SQL statement
hplsql/src/main/java/org/apache/hive/hplsql/functions/FunctionMisc.java