router.inc

<?php

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing;
use Symfony\Component\DependencyInjection\ParameterBag\ParameterBag;
use Drupal\Core\DrupalContainer;

/**
 * Execute the page callback associated with given request.
 *
 * @param Request $request
 *   The Symfony Request object used to determine what will be executed.
 * @return Response
 *   A Symfony Response object describing the response to deliver to the client.
 */
function router_execute_request(Request $request) {

  try {
    $parameters = new ParameterBag();
    $parameters->set('request', $request);

    $container = new DrupalContainer($parameters);
    $request->attributes->add($container->get('matcher')->match($request->getPathInfo()));
    return $container->get('kernel')->handle($request);
  }
  catch (Routing\Exception\ResourceNotFoundException $e) {
    $response = new Response('Not Found', 404);
  }
  //catch (Exception $e) {
  //  $response = new Response('An error occurred', 500);
  //}

  return $response;
}