@Override 
  public Integer visitExec_stmt(HplsqlParser.Exec_stmtContext ctx) { 
    exec.inCallStmt = true;
    Integer rc = exec.stmt.exec(ctx);
    exec.inCallStmt = false;
    return rc;
  }
EXEC, EXECUTE and EXECUTE IMMEDIATE statement to execute dynamic SQL
hplsql/src/main/java/org/apache/hive/hplsql/Exec.java