@Override
  public void dropRole(String roleName) throws HiveAuthzPluginException, HiveAccessControlException {
    // only user belonging to admin role can drop existing role
    if (!isUserAdmin()) {
      throw new HiveAccessControlException("Current user : " + currentUserName+ " is not"
      + " allowed to drop role. " + ADMIN_ONLY_MSG);
    }
    try {
      metastoreClientFactory.getHiveMetastoreClient().drop_role(roleName);
    } catch (Exception e) {
      throw SQLAuthorizationUtils.getPluginException("Error dropping role", e);
    }
  }
Add role names of parentRoles and its parents to processedRolesMap

@param processedRolesMap
@param roleGrants
@throws TException
@throws HiveAuthzPluginException
@throws MetaException
ql/src/java/org/apache/hadoop/hive/ql/security/authorization/plugin/sqlstd/SQLStdHiveAccessController.java