diff --git a/core/lib/Drupal.php b/core/lib/Drupal.php
index 363cf12..f2b26d6 100644
--- a/core/lib/Drupal.php
+++ b/core/lib/Drupal.php
@@ -5,10 +5,17 @@
  * Contains Drupal.
  */
 
+use Drupal\Core\DependencyInjection\PlaceholderContainer;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Drupal\Core\Url;
 
 /**
+ * Initialize \Drupal::$container with a placeholder object.
+ * See https://www.drupal.org/node/2363341
+ */
+\Drupal::initStaticProperties(NULL);
+
+/**
  * Static Service Container wrapper.
  *
  * Generally, code in Drupal should accept its dependencies via either
@@ -93,7 +100,7 @@ class Drupal {
   const CORE_MINIMUM_SCHEMA_VERSION = 8000;
 
   /**
-   * The currently active container object.
+   * The currently active container object, or a placeholder container.
    *
    * @var \Symfony\Component\DependencyInjection\ContainerInterface
    */
@@ -108,18 +115,46 @@ class Drupal {
    *   environment does not leak into a test.
    */
   public static function setContainer(ContainerInterface $container = NULL) {
+    if (!isset($container)) {
+      // @todo Remove the NULL case, and use unsetContainer() instead.
+      $container = new PlaceholderContainer('\Drupal::$container was unset with setContainer(NULL).');
+    }
     static::$container = $container;
   }
 
   /**
+   * @param string|null $message
+   */
+  public static function unsetContainer($message = NULL) {
+    if (!isset($message)) {
+      $message = '\Drupal::$container was unset with \Drupal::unsetContainer().';
+    }
+    static::setContainer(new PlaceholderContainer($message));
+  }
+
+  /**
+   * Initializes the static properties. Called from within the class file.
+   */
+  public static function initStaticProperties() {
+    $message = '\Drupal::$container is not initialized yet. \Drupal::setContainer() must be called with a real container.';
+    static::setContainer(new PlaceholderContainer($message));
+  }
+
+  /**
    * Returns the currently active global container.
    *
    * @deprecated This method is only useful for the testing environment. It
    * should not be used otherwise.
    *
-   * @return \Symfony\Component\DependencyInjection\ContainerInterface
+   * @return \Symfony\Component\DependencyInjection\ContainerInterface|null
    */
   public static function getContainer() {
+    if (static::$container instanceof PlaceholderContainer) {
+      // Currently, some components depend on this method returning NULL if not
+      // initialized.
+      // @todo Throw an exception instead, and change all code that expects NULL.
+      return NULL;
+    }
     return static::$container;
   }
 
@@ -149,7 +184,7 @@ public static function service($id) {
    *   TRUE if the specified service exists, FALSE otherwise.
    */
   public static function hasService($id) {
-    return static::$container && static::$container->has($id);
+    return static::$container->has($id);
   }
 
   /**
@@ -159,7 +194,8 @@ public static function hasService($id) {
    *   TRUE if there is a currently active request object, FALSE otherwise.
    */
   public static function hasRequest() {
-    return static::$container && static::$container->has('request_stack') && static::$container->get('request_stack')->getCurrentRequest() !== NULL;
+    return static::$container->has('request_stack')
+      && static::$container->get('request_stack')->getCurrentRequest() !== NULL;
   }
 
   /**
@@ -469,6 +505,17 @@ public static function urlGenerator() {
    * the base path (like robots.txt) use Url::fromUri()->toString() with the
    * base:// scheme.
    *
+   * @param string $route_name
+   *   The name of the route
+   * @param array $route_parameters
+   *   An associative array of parameter names and values.
+   * @param array $options
+   *   (optional) An associative array of additional options,
+   *
+   * @return string
+   *   The generated URL for the given route.
+   *
+   * @see \Drupal\Core\Routing\UrlGeneratorInterface::generateFromRoute()
    * @see \Drupal\Core\Url
    * @see \Drupal\Core\Url::fromRoute()
    * @see \Drupal\Core\Url::fromUri()
@@ -493,8 +540,15 @@ public static function linkGenerator() {
    * generate() method. For detailed documentation, see
    * \Drupal\Core\Routing\LinkGeneratorInterface::generate().
    *
+   * @param string $text
+   *   The link text for the anchor tag as a translated string or render array.
+   * @param \Drupal\Core\Url $url
+   *   The URL object used for the link,
+   *
+   * @return string
+   *   An HTML string containing a link to the given route and parameters.
+   *
    * @see \Drupal\Core\Utility\LinkGeneratorInterface::generate()
-   * @see \Drupal\Core\Url
    */
   public static function l($text, Url $url) {
     return static::$container->get('link_generator')->generate($text, $url);
diff --git a/core/lib/Drupal/Core/DependencyInjection/ContainerNotInitializedException.php b/core/lib/Drupal/Core/DependencyInjection/ContainerNotInitializedException.php
new file mode 100644
index 0000000..6de8116
--- /dev/null
+++ b/core/lib/Drupal/Core/DependencyInjection/ContainerNotInitializedException.php
@@ -0,0 +1,15 @@
+<?php
+
+
+namespace Drupal\Core\DependencyInjection;
+
+/**
+ * Exception thrown when a method is called that requires a container, but the
+ * container is not initialized yet.
+ *
+ * @see \Drupal
+ * @see \Drupal\Core\DependencyInjection\PlaceholderContainer
+ */
+class ContainerNotInitializedException extends \Exception {
+
+}
diff --git a/core/lib/Drupal/Core/DependencyInjection/PlaceholderContainer.php b/core/lib/Drupal/Core/DependencyInjection/PlaceholderContainer.php
new file mode 100644
index 0000000..3d285cc
--- /dev/null
+++ b/core/lib/Drupal/Core/DependencyInjection/PlaceholderContainer.php
@@ -0,0 +1,135 @@
+<?php
+
+
+namespace Drupal\Core\DependencyInjection;
+
+
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\DependencyInjection\ScopeInterface;
+
+/**
+ * A placeholder container that throws an exception whenever it does anything.
+ *
+ * Used in
+ * @see \Drupal::$container
+ * @see \Drupal\Core\DrupalKernel::$container
+ */
+class PlaceholderContainer implements ContainerInterface {
+
+  /**
+   * Message for ContainerNotInitializedException.
+   * 
+   * @var string
+   */
+  protected $message;
+
+  /**
+   * Constructs a PlaceholderContainer object.
+   * 
+   * @param string $exception_message
+   *   Message for ContainerNotInitializedException.
+   */
+  public function __construct($exception_message = NULL) {
+    $this->message = isset($exception_message)
+      ? $exception_message
+      : 'Container not initialized.';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function set($id, $service, $scope = self::SCOPE_CONTAINER) {
+    throw new ContainerNotInitializedException($this->message);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function get($id, $invalidBehavior = self::EXCEPTION_ON_INVALID_REFERENCE) {
+    throw new ContainerNotInitializedException($this->message);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function has($id) {
+    return FALSE;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getParameter($name) {
+    throw new ContainerNotInitializedException($this->message);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function hasParameter($name) {
+    throw new ContainerNotInitializedException($this->message);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setParameter($name, $value) {
+    throw new ContainerNotInitializedException($this->message);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function enterScope($name) {
+    throw new ContainerNotInitializedException($this->message);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function leaveScope($name) {
+    throw new ContainerNotInitializedException($this->message);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function addScope(ScopeInterface $scope) {
+    throw new ContainerNotInitializedException($this->message);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function hasScope($name) {
+    throw new ContainerNotInitializedException($this->message);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isScopeActive($name) {
+    throw new ContainerNotInitializedException($this->message);
+  }
+
+  /**
+   * Checks whether the given service has been initialized yet.
+   *
+   * This method is not part of Symfony's ContainerInterface, but it is needed
+   * for DrupalKernel::$container.
+   *
+   * @param string $id
+   *   The service identifier
+   *
+   * @return bool
+   *   TRUE, if the service has already been initialized. FALSE, otherwise
+   * @throws \Drupal\Core\DependencyInjection\ContainerNotInitializedException
+   *
+   * @see \Drupal\Core\DependencyInjection\Container::initialized()
+   * @see \Drupal\Core\DrupalKernel::$container
+   */
+  public function initialized($id) {
+    throw new ContainerNotInitializedException($this->message);
+  }
+
+}
diff --git a/core/lib/Drupal/Core/DrupalKernel.php b/core/lib/Drupal/Core/DrupalKernel.php
index c014e4a..afab8c8 100644
--- a/core/lib/Drupal/Core/DrupalKernel.php
+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -15,6 +15,7 @@
 use Drupal\Core\Config\NullStorage;
 use Drupal\Core\Database\Database;
 use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\Core\DependencyInjection\PlaceholderContainer;
 use Drupal\Core\DependencyInjection\ServiceProviderInterface;
 use Drupal\Core\DependencyInjection\YamlFileLoader;
 use Drupal\Core\Extension\ExtensionDiscovery;
@@ -27,10 +28,8 @@
 use Symfony\Component\DependencyInjection\Dumper\PhpDumper;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\HttpFoundation\RequestStack;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\TerminableInterface;
-use Composer\Autoload\ClassLoader;
 
 /**
  * The DrupalKernel class is the core of Drupal itself.
@@ -50,9 +49,20 @@ class DrupalKernel implements DrupalKernelInterface, TerminableInterface {
   const CONTAINER_BASE_CLASS = '\Drupal\Core\DependencyInjection\Container';
 
   /**
-   * Holds the container instance.
+   * The service container.
    *
-   * @var \Symfony\Component\DependencyInjection\ContainerInterface
+   * It is assumed that the container implements $container->initialized($id),
+   * There is currently no interface to define this method, hence the
+   * alternative "|\Drupal\..\Container" in the type hint.
+   *
+   * @todo Create an interface with $container->initialized($id).
+   *
+   * Before its initialization in $this->initializeContainer(), $this->container
+   * will be filled with a PlaceholderContainer object.
+   *
+   * @see \Drupal\Core\DependencyInjection\PlaceholderContainer
+   *
+   * @var \Symfony\Component\DependencyInjection\ContainerInterface|\Drupal\Core\DependencyInjection\Container
    */
   protected $container;
 
@@ -248,6 +258,7 @@ public function __construct($environment, $class_loader, $allow_dumping = TRUE)
     $this->environment = $environment;
     $this->classLoader = $class_loader;
     $this->allowDumping = $allow_dumping;
+    $this->container = new PlaceholderContainer('DrupalKernel::$container is not initialized yet.');
   }
 
   /**
@@ -404,7 +415,7 @@ public function shutdown() {
     }
     $this->container->get('stream_wrapper_manager')->unregister();
     $this->booted = FALSE;
-    $this->container = NULL;
+    $this->container = new PlaceholderContainer('DrupalKernel::$container is not available after shutdown.');
     $this->moduleList = NULL;
     $this->moduleData = array();
   }
@@ -413,6 +424,10 @@ public function shutdown() {
    * {@inheritdoc}
    */
   public function getContainer() {
+    if ($this->container instanceof PlaceholderContainer) {
+      // @todo Throw an exception?
+      return NULL;
+    }
     return $this->container;
   }
 
@@ -458,6 +473,7 @@ public function handlePageCache(Request $request) {
       $cache_enabled = TRUE;
     }
     else {
+      /** @var \Drupal\Core\Config\Config $config */
       $config = $this->getContainer()->get('config.factory')->get('system.performance');
       $cache_enabled = $config->get('cache.page.use_internal');
     }
@@ -550,8 +566,9 @@ public function terminate(Request $request, Response $response) {
       return;
     }
 
-    if ($this->getHttpKernel() instanceof TerminableInterface) {
-      $this->getHttpKernel()->terminate($request, $response);
+    $http_kernel = $this->getHttpKernel();
+    if ($http_kernel instanceof TerminableInterface) {
+      $http_kernel->terminate($request, $response);
     }
   }
 
@@ -596,16 +613,23 @@ protected function moduleData($module) {
       // If a module is within a profile directory but specifies another
       // profile for testing, it needs to be found in the parent profile.
       $settings = $this->getConfigStorage()->read('simpletest.settings');
-      $parent_profile = !empty($settings['parent_profile']) ? $settings['parent_profile'] : NULL;
+      $parent_profile = !empty($settings['parent_profile'])
+        ? $settings['parent_profile']
+        : NULL;
+
       if ($parent_profile && !isset($profiles[$parent_profile])) {
         // In case both profile directories contain the same extension, the
         // actual profile always has precedence.
         $profiles = array($parent_profile => $all_profiles[$parent_profile]) + $profiles;
       }
 
-      $profile_directories = array_map(function ($profile) {
-        return $profile->getPath();
-      }, $profiles);
+      $profile_directories = array_map(
+        function ($profile) {
+          /** @var \Drupal\Core\Extension\Extension $profile */
+          return $profile->getPath();
+        },
+        $profiles);
+
       $listing->setProfileDirectories($profile_directories);
 
       // Now find modules.
@@ -619,6 +643,11 @@ protected function moduleData($module) {
    *
    * @todo Remove obsolete $module_list parameter. Only $module_filenames is
    *   needed.
+   *
+   * @param array $module_list
+   *   The new list of modules.
+   * @param array $module_filenames
+   *   List of module filenames, keyed by module name.
    */
   public function updateModules(array $module_list, array $module_filenames = array()) {
     $this->moduleList = $module_list;
@@ -668,7 +697,7 @@ protected function getKernelParameters() {
   protected function initializeContainer($rebuild = FALSE) {
     $this->containerNeedsDumping = FALSE;
     $session_manager_started = FALSE;
-    if (isset($this->container)) {
+    if (!$this->container instanceof PlaceholderContainer) {
       // If there is a session manager, close and save the session.
       if ($this->container->initialized('session_manager')) {
         $session_manager = $this->container->get('session_manager');
@@ -703,6 +732,8 @@ protected function initializeContainer($rebuild = FALSE) {
 
     $this->attachSynthetic($container);
 
+    // From here forward, $this->container is definitely not a
+    // PlaceholderContainer anymore, but a "real" container.
     $this->container = $container;
     if ($session_manager_started) {
       $this->container->get('session_manager')->start();
@@ -928,6 +959,12 @@ protected function initializeCookieGlobals(Request $request) {
 
   /**
    * Returns service instances to persist from an old container to a new one.
+   *
+   * @param \Symfony\Component\DependencyInjection\ContainerInterface|\Drupal\Core\DependencyInjection\Container $container
+   *   A service container that implements $container->initialized($id)
+   *
+   * @return object[]
+   *   Array of services to persist, keyed by service id.
    */
   protected function getServicesToPersist(ContainerInterface $container) {
     $persist = array();
@@ -942,6 +979,11 @@ protected function getServicesToPersist(ContainerInterface $container) {
 
   /**
    * Moves persistent service instances into a new container.
+   *
+   * @param \Symfony\Component\DependencyInjection\ContainerInterface|\Drupal\Core\DependencyInjection\Container $container
+   *   A service container that implements $container->initialized($id)
+   * @param object[] $persist
+   *   Array of services to persist, keyed by service id.
    */
   protected function persistServices(ContainerInterface $container, array $persist) {
     foreach ($persist as $id => $object) {
@@ -975,7 +1017,7 @@ public function rebuildContainer() {
    */
   protected function attachSynthetic(ContainerInterface $container) {
     $persist = array();
-    if (isset($this->container)) {
+    if (!$this->container instanceof PlaceholderContainer) {
       $persist = $this->getServicesToPersist($this->container);
     }
     $this->persistServices($container, $persist);
diff --git a/core/lib/Drupal/Core/DrupalKernelInterface.php b/core/lib/Drupal/Core/DrupalKernelInterface.php
index a5eb3b9..91ea20c 100644
--- a/core/lib/Drupal/Core/DrupalKernelInterface.php
+++ b/core/lib/Drupal/Core/DrupalKernelInterface.php
@@ -52,8 +52,8 @@ public function getServiceProviders($origin);
   /**
    * Gets the current container.
    *
-   * @return \Symfony\Component\DependencyInjection\ContainerInterface
-   *   A ContainerInterface instance.
+   * @return \Symfony\Component\DependencyInjection\ContainerInterface|null
+   *   A ContainerInterface instance, or NULL if not initialized yet.
    */
   public function getContainer();