[ClassLoader] Added a DebugClassLoader using composition

CHANGELOG-2.1.md

@@ -178,6 +178,7 @@ To get the diff between two versions, go to https://github.com/symfony/symfony/c
 
 ### ClassLoader
 
+ * added a DebugClassLoader able to wrap any autoloader providing a findFile method
  * added a new ApcClassLoader using composition to wrap other loaders
  * added a new ClassLoader which does not distinguish between namespaced and pear-like classes (as the PEAR
    convention is a subset of PSR-0) and supports using Composer's namespace maps

src/Symfony/Component/ClassLoader/DebugClassLoader.php

@@ -0,0 +1,90 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\ClassLoader;
+
+/**
+ * Autoloader checking if the class is really defined in the file found.
+ *
+ * The DebugClassLoader will wrap all registered autoloaders providing a
+ * findFile method and will throw an exception if a file is found but does
+ * not declare the class.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ * @author Christophe Coevoet <stof@notk.org>
+ *
+ * @api
+ */
+class DebugClassLoader
+{
+    private $classFinder;
+
+    /**
+     * Constructor.
+     *
+     * @param object $classFinder
+     *
+     * @api
+     */
+    public function __construct($classFinder)
+    {
+        $this->classFinder = $classFinder;
+    }
+
+    /**
+     * Replaces all autoloaders implementing a findFile method by a DebugClassLoader wrapper.
+     */
+    static public function enable()
+    {
+        if (!is_array($functions = spl_autoload_functions())) {
+            return;
+        }
+
+        foreach ($functions as $function) {
+            spl_autoload_unregister($function);
+        }
+
+        foreach ($functions as $function) {
+            if (is_array($function) && method_exists($function[0], 'findFile')) {
+                $function = array(new static($function[0]), 'loadClass');
+            }
+
+            spl_autoload_register($function);
+        }
+    }
+
+    /**
+     * Unregisters this instance as an autoloader.
+     */
+    public function unregister()
+    {
+        spl_autoload_unregister(array($this, 'loadClass'));
+    }
+
+    /**
+     * Loads the given class or interface.
+     *
+     * @param string $class The name of the class
+     * @return Boolean|null True, if loaded
+     */
+    public function loadClass($class)
+    {
+        if ($file = $this->classFinder->findFile($class)) {
+            require $file;
+
+            if (!class_exists($class, false) && !interface_exists($class, false) && (!function_exists('trait_exists') || !trait_exists($class, false))) {
+                throw new \RuntimeException(sprintf('The autoloader expected class "%s" to be defined in file "%s". The file was found but the class was not in it, the class name or namespace probably has a typo.', $class, $file));
+            }
+
+            return true;
+        }
+    }
+}

src/Symfony/Component/HttpKernel/Kernel.php

@@ -34,7 +34,7 @@ use Symfony\Component\Config\Loader\LoaderResolver;
 use Symfony\Component\Config\Loader\DelegatingLoader;
 use Symfony\Component\Config\ConfigCache;
 use Symfony\Component\ClassLoader\ClassCollectionLoader;
-use Symfony\Component\ClassLoader\DebugUniversalClassLoader;
+use Symfony\Component\ClassLoader\DebugClassLoader;
 
 /**
  * The Kernel is the heart of the Symfony system.
@@ -91,7 +91,7 @@ abstract class Kernel implements KernelInterface, TerminableInterface
             ini_set('display_errors', 1);
             error_reporting(-1);
 
-            DebugUniversalClassLoader::enable();
+            DebugClassLoader::enable();
             ErrorHandler::register($this->errorReportingLevel);
             if ('cli' !== php_sapi_name()) {
                 ExceptionHandler::register();