If you use an annotation resource pointing to a controller directory

in your routing configuration, only existing files in this directory
get tracked for changes in this directory. So if you add a new
controller file in this directory you'd have to manually clear the
cache since the new file gets ignored.
This patch adds a DirectoryResource for this case which tracks all
changes in the given directory (and files and directories contained
within).

src/Symfony/Component/Config/Resource/DirectoryResource.php

@@ -0,0 +1,72 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien.potencier@symfony-project.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Config\Resource;
+
+/**
+ * DirectoryResource represents a resources stored in a subdirectory tree.
+ *
+ * @author Fabien Potencier <fabien.potencier@symfony-project.com>
+ */
+class DirectoryResource implements ResourceInterface
+{
+    protected $resource;
+
+    /**
+     * Constructor.
+     *
+     * @param string $resource The file path to the resource
+     */
+    public function __construct($resource)
+    {
+        $this->resource = realpath($resource);
+    }
+
+    /**
+     * Returns a string representation of the Resource.
+     *
+     * @return string A string representation of the Resource
+     */
+    public function __toString()
+    {
+        return (string) $this->resource;
+    }
+
+    /**
+     * Returns the resource tied to this Resource.
+     *
+     * @return mixed The resource
+     */
+    public function getResource()
+    {
+        return $this->resource;
+    }
+
+    /**
+     * Returns true if the resource has not been updated since the given timestamp.
+     *
+     * @param integer $timestamp The last time the resource was loaded
+     *
+     * @return Boolean true if the resource has not been updated, false otherwise
+     */
+    public function isFresh($timestamp)
+    {
+        if (!file_exists($this->resource)) {
+            return false;
+        }
+
+        $newestMTime = 0;
+        foreach (new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($this->resource), \RecursiveIteratorIterator::LEAVES_ONLY) as $file) {
+          $newestMTime = max(filemtime($file), $newestMTime);
+        }
+        return $newestMTime < $timestamp;
+    }
+}

src/Symfony/Component/Routing/Loader/AnnotationDirectoryLoader.php

@@ -12,7 +12,7 @@
 namespace Symfony\Component\Routing\Loader;
 
 use Symfony\Component\Routing\RouteCollection;
-use Symfony\Component\Config\Resource\FileResource;
+use Symfony\Component\Config\Resource\DirectoryResource;
 
 /**
  * AnnotationDirectoryLoader loads routing information from annotations set
@@ -37,13 +37,13 @@ class AnnotationDirectoryLoader extends AnnotationFileLoader
         $dir = $this->locator->locate($path);
 
         $collection = new RouteCollection();
+	$collection->addResource(new DirectoryResource($dir));
         foreach (new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($dir), \RecursiveIteratorIterator::LEAVES_ONLY) as $file) {
             if (!$file->isFile() || '.php' !== substr($file->getFilename(), -4)) {
                 continue;
             }
 
             if ($class = $this->findClass($file)) {
-                $collection->addResource(new FileResource($file));
                 $collection->addCollection($this->loader->load($class, $type));
             }
         }