diff --git a/core/core.services.yml b/core/core.services.yml
index bbc9e8e..8fb7a70 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -470,6 +470,12 @@ services:
       - { name: service_collector, tag: 'module_install.uninstall_validator', call: addUninstallValidator }
     arguments: ['@app.root', '@module_handler', '@kernel']
     lazy: true
+  module_listing:
+    class: Drupal\Core\Extension\ModuleExtensionList
+    arguments: ['@app.root', 'module', '@cache.default', '@info_parser', '@module_handler', '@state', '@config.factory', '@profile_listing']
+  profile_listing:
+    class: Drupal\Core\Extension\ProfileExtensionList
+    arguments: ['@app.root', 'profile', '@cache.default', '@info_parser', '@module_handler', '@state']
   content_uninstall_validator:
     class: Drupal\Core\Entity\ContentUninstallValidator
     tags:
diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index ce872d4..3f59276 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -198,11 +198,17 @@ function drupal_get_filename($type, $name, $filename = NULL) {
     return 'core/core.info.yml';
   }
 
-  // Profiles are converted into modules in system_rebuild_module_data().
-  // @todo Remove false-exposure of profiles as modules.
-  if ($type == 'profile') {
-    $type = 'module';
+  if ($type === 'module' || $type === 'profile') {
+    $service = $type . '_listing';
+    if (isset($filename)) {
+      // Manually add the info file path of an extension.
+      return \Drupal::service($service)->setFilename($name);
+    }
+    else {
+      return \Drupal::service($service)->getFilename($name);
+    }
   }
+
   if (!isset($files[$type])) {
     $files[$type] = array();
   }
@@ -211,15 +217,6 @@ function drupal_get_filename($type, $name, $filename = NULL) {
     $files[$type][$name] = $filename;
   }
   elseif (!isset($files[$type][$name])) {
-    // If the pathname of the requested extension is not known, try to retrieve
-    // the list of extension pathnames from various providers, checking faster
-    // providers first.
-    // Retrieve the current module list (derived from the service container).
-    if ($type == 'module' && \Drupal::hasService('module_handler')) {
-      foreach (\Drupal::moduleHandler()->getModuleList() as $module_name => $module) {
-        $files[$type][$module_name] = $module->getPathname();
-      }
-    }
     // If still unknown, retrieve the file list prepared in state by
     // system_rebuild_module_data() and
     // \Drupal\Core\Extension\ThemeHandlerInterface::rebuildThemeData().
diff --git a/core/includes/module.inc b/core/includes/module.inc
index bc50d2c..cd2575c 100644
--- a/core/includes/module.inc
+++ b/core/includes/module.inc
@@ -57,7 +57,7 @@ function system_list($type) {
  */
 function system_list_reset() {
   drupal_static_reset('system_list');
-  drupal_static_reset('system_rebuild_module_data');
+  \Drupal::service('module_listing')->reset();
   \Drupal::cache('bootstrap')->delete('system_list');
 }
 
diff --git a/core/lib/Drupal/Core/Config/ConfigInstaller.php b/core/lib/Drupal/Core/Config/ConfigInstaller.php
index a77bb1c..163df5c 100644
--- a/core/lib/Drupal/Core/Config/ConfigInstaller.php
+++ b/core/lib/Drupal/Core/Config/ConfigInstaller.php
@@ -604,7 +604,13 @@ protected function getProfileStorages($installing_name = '') {
    *   The extension's default configuration directory.
    */
   protected function getDefaultConfigDirectory($type, $name) {
-    return $this->drupalGetPath($type, $name) . '/' . InstallStorage::CONFIG_INSTALL_DIRECTORY;
+    if ($type === 'module' || $type === 'profile') {
+      return dirname(\Drupal::service('module_listing')->getFilenames()[$name])
+          . '/' . InstallStorage::CONFIG_INSTALL_DIRECTORY;
+    }
+    else {
+      return $this->drupalGetPath($type, $name) . '/' . InstallStorage::CONFIG_INSTALL_DIRECTORY;
+    }
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Extension/ExtensionList.php b/core/lib/Drupal/Core/Extension/ExtensionList.php
new file mode 100644
index 0000000..a0f9a7e
--- /dev/null
+++ b/core/lib/Drupal/Core/Extension/ExtensionList.php
@@ -0,0 +1,421 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Extension\ExtensionList.
+ */
+
+namespace Drupal\Core\Extension;
+
+use Drupal\Component\Render\FormattableMarkup;
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\State\StateInterface;
+
+/**
+ * Provides available extensions.
+ */
+abstract class ExtensionList {
+
+  /**
+   * The type of the extension, either 'module' or 'theme'.
+   *
+   * @var string
+   */
+  protected $type;
+
+  /**
+   * The app root.
+   *
+   * @var string
+   */
+  protected $root;
+
+  /**
+   * The cache.
+   *
+   * @var \Drupal\Core\Cache\CacheBackendInterface
+   */
+  protected $cache;
+
+  /**
+   * The state service.
+   */
+  protected $state;
+
+  /**
+   * Default information added to every extension.
+   *
+   * @var array
+   */
+  protected $defaults = [];
+
+  /**
+   * The info parser.
+   *
+   * @var \Drupal\Core\Extension\InfoParserInterface
+   */
+  protected $infoParser;
+
+  /**
+   * The module handler.
+   *
+   * @var \Drupal\Core\Extension\ModuleHandlerInterface
+   */
+  protected $moduleHandler;
+
+  /**
+   * The static cached extensions.
+   *
+   * @var \Drupal\Core\Extension\Extension[]
+   */
+  protected $extensions;
+
+  /**
+   * Static caching for extension info.
+   *
+   * @var array
+   */
+  protected $extensionInfo;
+
+  /**
+   * A list of extension folder names keyed by extension name.
+   *
+   * @var string[]
+   */
+  protected $fileNames;
+
+  /**
+   * A list of extension folder names directly added in code (not discovered).
+   *
+   * It is important to keep a separate list to ensure that it takes priority
+   * over the discovered extension folder.
+   *
+   * @var string[]
+   */
+  protected $addedFileNames;
+
+  /**
+   * The extension discovery service.
+   *
+   * @var \Drupal\Core\Extension\ExtensionDiscovery
+   */
+  protected $extensionDiscovery;
+
+  /**
+   * Constructs a new ExtensionList instance.
+   *
+   * @param string $root
+   *   The app root.
+   * @param string $type
+   *   The extension type.
+   * @param \Drupal\Core\Cache\CacheBackendInterface $cache
+   *   The cache.
+   * @param \Drupal\Core\Extension\InfoParserInterface $info_parser
+   *   The info parser.
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler.
+   * @param \Drupal\Core\State\StateInterface $state
+   *   The state service.
+   */
+  public function __construct($root, $type, CacheBackendInterface $cache, InfoParserInterface $info_parser, ModuleHandlerInterface $module_handler, StateInterface $state) {
+    $this->root = $root;
+    $this->type = $type;
+    $this->cache = $cache;
+    $this->state = $state;
+    $this->infoParser = $info_parser;
+    $this->moduleHandler = $module_handler;
+    $this->extensionDiscovery = new ExtensionDiscovery($root);
+  }
+
+  /**
+   * Resets the stored extension list.
+   */
+  public function reset() {
+    $this->addedFileNames = NULL;
+    $this->cache->delete($this->getCacheId());
+    $this->extensionInfo = NULL;
+    $this->cache->delete("system.{$this->type}.info");
+    $this->fileNames = NULL;
+    $this->state->delete("system.{$this->type}.files");
+    $this->extensions = NULL;
+    return $this;
+  }
+
+  /**
+   * Returns the used cache ID.
+   *
+   * @return string
+   */
+  protected function getCacheId() {
+    return 'core.extension_listing.' . $this->type;
+  }
+
+  /**
+   * Returns the human readable name of the extension.
+   *
+   * @param string $machine_name
+   *   The extension name.
+   *
+   * @return string
+   *   The human readable name of the extension.
+   *
+   * @throws \InvalidArgumentException
+   *   If there is no extension with the supplied machine name.
+   */
+  public function getName($machine_name) {
+    $extensions = $this->listExtensions();
+    if (isset($extensions[$machine_name])) {
+      return $extensions[$machine_name]->info['name'];
+    }
+    throw new \InvalidArgumentException(new FormattableMarkup('The @type %name does not exist.', ['@type' => $this->type, '%name' => $machine_name]));
+  }
+
+  /**
+   * Returns a single extension.
+   *
+   * @param string $name
+   *   The extension name.
+   *
+   * @return \Drupal\Core\Extension\Extension
+   *
+   * @throws \InvalidArgumentException
+   *   If there is no extension with the supplied name.
+   */
+  public function getExtension($name) {
+    $extensions = $this->listExtensions();
+    if (!isset($extensions[$name])) {
+      return $extensions[$name];
+    }
+
+    throw new \InvalidArgumentException(new FormattableMarkup('The @type %name does not exist.', ['@type' => $this->type, '%name' => $name]));
+  }
+
+  /**
+   * Returns all available extensions.
+   *
+   * @return \Drupal\Core\Extension\Extension[]
+   */
+  public function listExtensions() {
+    if (isset($this->extensions)) {
+      return $this->extensions;
+    }
+    if ($cache = $this->cache->get($this->getCacheId())) {
+      $this->extensions = $cache->data;
+      return $this->extensions;
+    }
+    $extensions = $this->doListExtensions();
+    $this->cache->set($this->getCacheId(), $extensions);
+    $this->extensions = $extensions;
+    return $this->extensions;
+  }
+
+  /**
+   * Scans the available extensions.
+   *
+   * Overriding this method gives other code the chance to add additional
+   * extensions to this raw listing.
+   *
+   * @return \Drupal\Core\Extension\Extension[]
+   */
+  protected function doScanExtensions() {
+    return $this->extensionDiscovery->scan($this->type);
+  }
+
+  /**
+   * Build the actual list of extensions before caching it.
+   *
+   * @return \Drupal\Core\Extension\Extension[]
+   */
+  protected function doListExtensions() {
+    // Find extensions.
+    $extensions = $this->doScanExtensions();
+
+    // Read info files for each extension.
+    foreach ($extensions as $name => $extension) {
+      // Look for the info file.
+      $extension->info = $this->infoParser->parse($extension->getPathname());
+
+      // Add the info file modification time, so it becomes available for
+      // contributed extensions to use for ordering extension lists.
+      $extension->info['mtime'] = $extension->getMTime();
+
+      // Merge in defaults and save.
+      $extensions[$name]->info = $extension->info + $this->defaults;
+
+      // Invoke hook_system_info_alter() to give installed modules a chance to
+      // modify the data in the .info.yml files if necessary.
+      $this->moduleHandler->alter('system_info', $extensions[$name]->info, $extensions[$name], $this->type);
+    }
+
+    return $extensions;
+  }
+
+  /**
+   * Returns information about a specified module or theme.
+   *
+   * This function returns the contents of the .info.yml file for the specified
+   * installed module or theme.
+   *
+   * @param string $name
+   *   The name of a module or theme whose information shall be returned. If
+   *   $name does not exist or is not enabled, an empty array will be returned.
+   *
+   * @return array|null
+   *   An associative array of module or theme information. NULL if the module
+   *   is disabled or does not exist.
+   */
+  public function getInfo($name) {
+    // Ensure that $this->extensionInfo is primed.
+    $this->getAllInfo();
+    return isset($this->extensionInfo[$name]) ? $this->extensionInfo[$name] : NULL;
+  }
+
+  /**
+   * Returns an array of information about enabled modules or themes.
+   *
+   * This function returns the contents of the .info.yml file for each installed
+   * module or theme.
+   *
+   * @return array
+   *   An associative array of module or theme information keyed by name. If no
+   *   records are available, an empty array is returned.
+   */
+  public function getAllInfo() {
+    if (!isset($this->extensionInfo)) {
+      if ($cache = $this->cache->get("system.{$this->type}.info")) {
+        $info = $cache->data;
+      }
+      else {
+        $info = $this->recalculateInfo();
+      }
+      $this->extensionInfo = $info;
+    }
+    return $this->extensionInfo;
+  }
+
+  /**
+   * Generates the information from .info.yml files for extensions of this type.
+   *
+   * The information is placed in cache with the "system.{extension_type}.info"
+   * key.
+   *
+   * @return array
+   *   An array of arrays of .info.yml entries keyed by the extension name.
+   */
+  protected function recalculateInfo() {
+    $info = [];
+    foreach ($this->listExtensions() as $name => $extension) {
+      $info[$name] = $extension->info;
+    }
+    // Store the module information in cache.
+    $this->cache->set("system.{$this->type}.info", $info);
+    return $info;
+  }
+
+  /**
+   * Returns a list of extension folder names keyed by extension name.
+   *
+   * @return string[]
+   */
+  public function getFilenames() {
+    if (!isset($this->fileNames)) {
+      $file_names = $this->state->get("system.{$this->type}.files");
+      if (!isset($file_names)) {
+        $file_names = $this->recalculateFilenames();
+      }
+      $this->fileNames = $file_names;
+    }
+    return $this->fileNames;
+  }
+
+  /**
+   * Generates a sorted list of .info.yml file locations for all extensions.
+   *
+   * The information is placed in state with the "system.{extension_type}.files"
+   * key.
+   *
+   * @return array
+   *   An array of .info.yml file locations keyed by the extension name.
+   */
+  protected function recalculateFilenames() {
+    $file_names = [];
+    $extensions = $this->listExtensions();
+    ksort($extensions);
+    foreach ($extensions as $name => $extension) {
+      $file_names[$name] = $extension->getPathname();
+    }
+    $this->state->set("system.{$this->type}.files", $file_names);
+    return $file_names;
+  }
+
+  /**
+   * Sets the filename for an extension.
+   *
+   * @param string $extension_name
+   *   The name of the extension for which the filename is requested.
+   * @param string $filename
+   *   The filename of the item which is to be set explicitly rather
+   *   than by consulting the dynamic modules listing.
+   */
+  public function setFilename($extension_name, $filename) {
+    $this->addedFileNames[$extension_name] = $filename;
+  }
+
+  /**
+   * Gets the filename for a system resource.
+   *
+   * The filename, whether provided, cached, or retrieved from the database, is
+   * only returned if the file exists.
+   *
+   * This function plays a key role in allowing Drupal's resources (modules
+   * and themes) to be located in different places depending on a site's
+   * configuration. For example, a module 'foo' may legally be located
+   * in any of these three places:
+   *
+   * core/modules/foo/foo.info.yml
+   * modules/foo/foo.info.yml
+   * sites/example.com/modules/foo/foo.info.yml
+   * core/themes/foo/foo.info.yml
+   * themes/foo/foo.info.yml
+   *
+   * Calling ExtensionList::getFilename('foo') will give you one of the above,
+   * depending on where the extension is located and what type it is.
+   *
+   * @param string $extension_name
+   *   The name of the item for which the filename is requested. Ignored for
+   *   $type 'core'.
+   *
+   * @return string
+   *   The filename of the requested item if it is found. An error is triggered
+   *   if it is not.
+   */
+  public function getFilename($extension_name) {
+    // Ensure that $this->fileNames is primed.
+    $this->getFilenames();
+    if (isset($this->addedFileNames[$extension_name])) {
+      return $this->addedFileNames[$extension_name];
+    }
+    else if (isset($this->fileNames[$extension_name])) {
+      return $this->fileNames[$extension_name];
+    }
+    else {
+      trigger_error(new FormattableMarkup('The following @type is missing from the file system: @name', array('@type' => $this->type, '@name' => $extension_name)), E_USER_WARNING);
+    }
+  }
+
+
+  /**
+   * Gets the path to an extension of a specific type (module, theme, etc.).
+   *
+   * @param string $extension_name
+   *   The name of the extension for which the path is requested.
+   *
+   * @return string
+   *   The drupal root-relative path to the specified extension. An error is
+   *   triggered if the extension is not found.
+   */
+  public function getPath($extension_name) {
+    return dirname($this->getFilename($extension_name));
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Extension/ModuleExtensionList.php b/core/lib/Drupal/Core/Extension/ModuleExtensionList.php
new file mode 100644
index 0000000..e925aac
--- /dev/null
+++ b/core/lib/Drupal/Core/Extension/ModuleExtensionList.php
@@ -0,0 +1,170 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Extension\ModuleExtensionList.
+ */
+
+namespace Drupal\Core\Extension;
+
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Core\State\StateInterface;
+use Drupal\Core\StringTranslation\StringTranslationTrait;
+
+/**
+ * Provides a list of available modules.
+ */
+class ModuleExtensionList extends ExtensionList {
+
+  use StringTranslationTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaults = [
+    'dependencies' => [],
+    'description' => '',
+    'package' => 'Other',
+    'version' => NULL,
+    'php' => DRUPAL_MINIMUM_PHP,
+  ];
+
+  /**
+   * The config factory.
+   *
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
+   */
+  protected $configFactory;
+
+  /**
+   * The profile list needed by this module list.
+   *
+   * @var \Drupal\Core\Extension\ExtensionList
+   */
+  protected $profileList;
+
+  /**
+   * Constructs a new ModuleExtensionList instance.
+   *
+   * @param string $root
+   *   The app root.
+   * @param string $type
+   *   The extension type.
+   * @param \Drupal\Core\Cache\CacheBackendInterface $cache
+   *   The cache.
+   * @param \Drupal\Core\Extension\InfoParserInterface $info_parser
+   *   The info parser.
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler.
+   * @param \Drupal\Core\State\StateInterface $state
+   *   The state service.
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+   *   The config factory.
+   * @param \Drupal\Core\Extension\ExtensionList $profile_list
+   *   The site profile listing.
+   */
+  public function __construct($root, $type, CacheBackendInterface $cache, InfoParserInterface $info_parser, ModuleHandlerInterface $module_handler, StateInterface $state, ConfigFactoryInterface $config_factory, ExtensionList $profile_list) {
+    parent::__construct($root, $type, $cache, $info_parser, $module_handler, $state);
+
+    $this->configFactory = $config_factory;
+    $this->profileList = $profile_list;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function doScanExtensions() {
+    $extensions = parent::doScanExtensions();
+
+    // Find installation profiles.
+    $profiles = $this->profileList->listExtensions();
+
+    // Include the installation profile in modules that are loaded.
+    if ($profile = drupal_get_profile()) {
+      $extensions[$profile] = $profiles[$profile];
+      // Installation profile hooks are always executed last.
+      $extensions[$profile]->weight = 1000;
+    }
+
+    return $extensions;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function doListExtensions() {
+    // Find installation profiles. This needs to happen before performing a
+    // module scan as the module scan needs to know what the active profile is.
+    $profiles = $this->profileList->listExtensions();
+    $profile = drupal_get_profile();
+    if ($profile && isset($profiles[$profile])) {
+      // Set the profile in the ExtensionDiscovery so we can scan from the right
+      // profile directory.
+      $this->extensionDiscovery->setProfileDirectories([
+        $profile => $profiles[$profile]->getPathname(),
+      ]);
+    }
+
+    // Find modules.
+    $extensions = parent::doListExtensions();
+    // It is possible that a module was marked as required by
+    // hook_system_info_alter() and modules that it depends on are not required.
+    foreach ($extensions as $extension) {
+      $this->ensureRequiredDependencies($extension, $extensions);
+    }
+
+    if ($profile) {
+      // Installation profiles are hidden by default, unless explicitly
+      // specified otherwise in the .info.yml file.
+      if (!isset($extensions[$profile]->info['hidden'])) {
+        $extensions[$profile]->info['hidden'] = TRUE;
+      }
+
+      if (isset($extensions[$profile])) {
+        // The installation profile is required, if it's a valid module.
+        $extensions[$profile]->info['required'] = TRUE;
+        // Add a default distribution name if the profile did not provide one.
+        // @see install_profile_info()
+        // @see drupal_install_profile_distribution_name()
+        if (!isset($extensions[$profile]->info['distribution']['name'])) {
+          $extensions[$profile]->info['distribution']['name'] = 'Drupal';
+        }
+      }
+    }
+
+    // Add status, weight, and schema version.
+    $installed_modules = $this->configFactory->get('core.extension')->get('module') ?: [];
+    foreach ($extensions as $name => $module) {
+      $module->weight = isset($installed_modules[$name]) ? $installed_modules[$name] : 0;
+      $module->status = (int) isset($installed_modules[$name]);
+      $module->schema_version = SCHEMA_UNINSTALLED;
+    }
+    $extensions = $this->moduleHandler->buildModuleDependencies($extensions);
+
+    return $extensions;
+  }
+
+  /**
+   * Ensures that dependencies of required modules are also required.
+   *
+   * @param \Drupal\Core\Extension\Extension $module
+   *   The module info.
+   * @param \Drupal\Core\Extension\Extension[] $modules
+   *   The array of all module info.
+   */
+  protected function ensureRequiredDependencies(Extension $module, array $modules = []) {
+    if (!empty($module->info['required'])) {
+      foreach ($module->info['dependencies'] as $dependency) {
+        $dependency_name = ModuleHandler::parseDependency($dependency)['name'];
+        if (!isset($modules[$dependency_name]->info['required'])) {
+          $modules[$dependency_name]->info['required'] = TRUE;
+          $modules[$dependency_name]->info['explanation'] = $this->t('Dependency of required module @module', array('@module' => $module->info['name']));
+          // Ensure any dependencies it has are required.
+         $this->ensureRequiredDependencies($modules[$dependency_name], $modules);
+        }
+      }
+    }
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Extension/ModuleHandler.php b/core/lib/Drupal/Core/Extension/ModuleHandler.php
index 05f1e4f..2b3ae21 100644
--- a/core/lib/Drupal/Core/Extension/ModuleHandler.php
+++ b/core/lib/Drupal/Core/Extension/ModuleHandler.php
@@ -722,8 +722,7 @@ public function getModuleDirectories() {
    * {@inheritdoc}
    */
   public function getName($module) {
-    $info = system_get_info('module', $module);
-    return isset($info['name']) ? $info['name'] : $module;
+    return \Drupal::service('module_listing')->getName($module);
   }
 
 }
diff --git a/core/lib/Drupal/Core/Extension/ModuleInstaller.php b/core/lib/Drupal/Core/Extension/ModuleInstaller.php
index f8300cb..36e8ed8 100644
--- a/core/lib/Drupal/Core/Extension/ModuleInstaller.php
+++ b/core/lib/Drupal/Core/Extension/ModuleInstaller.php
@@ -171,7 +171,7 @@ public function install(array $module_list, $enable_dependencies = TRUE) {
             $module_filenames[$name] = $current_module_filenames[$name];
           }
           else {
-            $module_path = drupal_get_path('module', $name);
+            $module_path = dirname(\Drupal::service('module_listing')->getFilenames()[$name]);
             $pathname = "$module_path/$name.info.yml";
             $filename = file_exists($module_path . "/$name.module") ? "$name.module" : NULL;
             $module_filenames[$name] = new Extension($this->root, 'module', $pathname, $filename);
@@ -190,7 +190,7 @@ public function install(array $module_list, $enable_dependencies = TRUE) {
         // Clear the static cache of system_rebuild_module_data() to pick up the
         // new module, since it merges the installation status of modules into
         // its statically cached list.
-        drupal_static_reset('system_rebuild_module_data');
+        \Drupal::service('module_listing')->reset();
 
         // Update the kernel to include it.
         $this->updateKernel($module_filenames);
@@ -426,10 +426,10 @@ public function uninstall(array $module_list, $uninstall_dependents = TRUE) {
       // Remove any potential cache bins provided by the module.
       $this->removeCacheBins($module);
 
-      // Clear the static cache of system_rebuild_module_data() to pick up the
+      // Clear the static cache of ModuleExtensionList to pick up the
       // new module, since it merges the installation status of modules into
       // its statically cached list.
-      drupal_static_reset('system_rebuild_module_data');
+      \Drupal::service('module_listing')->reset();
 
       // Clear plugin manager caches.
       \Drupal::getContainer()->get('plugin.cache_clearer')->clearCachedDefinitions();
diff --git a/core/lib/Drupal/Core/Extension/ProfileExtensionList.php b/core/lib/Drupal/Core/Extension/ProfileExtensionList.php
new file mode 100644
index 0000000..8bae168
--- /dev/null
+++ b/core/lib/Drupal/Core/Extension/ProfileExtensionList.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Drupal\Core\Extension;
+
+class ProfileExtensionList extends ExtensionList {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaults = [
+    'dependencies' => [],
+    'description' => '',
+    'package' => 'Other',
+    'version' => NULL,
+    'php' => DRUPAL_MINIMUM_PHP,
+  ];
+
+}
diff --git a/core/modules/book/src/Tests/BookUninstallTest.php b/core/modules/book/src/Tests/BookUninstallTest.php
index 0a18fb1..45dac11 100644
--- a/core/modules/book/src/Tests/BookUninstallTest.php
+++ b/core/modules/book/src/Tests/BookUninstallTest.php
@@ -81,7 +81,7 @@ public function testBookUninstall() {
 
     $book_node->delete();
     // No nodes exist therefore the book module is not required.
-    $module_data = _system_rebuild_module_data();
+    $module_data = \Drupal::service('module_listing')->reset()->listExtensions();
     $this->assertFalse(isset($module_data['book']->info['required']), 'The book module is not required.');
 
     $node = Node::create(array('title' => $this->randomString(), 'type' => $content_type->id()));
diff --git a/core/modules/filter/src/Tests/FilterAPITest.php b/core/modules/filter/src/Tests/FilterAPITest.php
index 5fd9999..f56c59e 100644
--- a/core/modules/filter/src/Tests/FilterAPITest.php
+++ b/core/modules/filter/src/Tests/FilterAPITest.php
@@ -489,7 +489,8 @@ public function testDependencyRemoval() {
 
     drupal_static_reset('filter_formats');
     \Drupal::entityManager()->getStorage('filter_format')->resetCache();
-    $module_data = _system_rebuild_module_data();
+    \Drupal::service('module_listing')->reset();
+    $module_data = \Drupal::service('module_listing')->listExtensions();
     $this->assertFalse(isset($module_data['filter_test']->info['required']), 'The filter_test module is required.');
 
     // Verify that a dependency exists on the module that provides the filter
diff --git a/core/modules/system/src/Tests/Bootstrap/GetFilenameUnitTest.php b/core/modules/system/src/Tests/Bootstrap/GetFilenameUnitTest.php
index 27ca162..dc6763a 100644
--- a/core/modules/system/src/Tests/Bootstrap/GetFilenameUnitTest.php
+++ b/core/modules/system/src/Tests/Bootstrap/GetFilenameUnitTest.php
@@ -26,8 +26,6 @@ function testDrupalGetFilename() {
     $install_state['parameters']['profile'] = 'testing';
 
     // Rebuild system.module.files state data.
-    // @todo Remove as part of https://www.drupal.org/node/2186491
-    drupal_static_reset('system_rebuild_module_data');
     system_rebuild_module_data();
 
     // Retrieving the location of a module.
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 7bfe57b..9e541c4 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -888,27 +888,10 @@ function system_check_directory($form_element, FormStateInterface $form_state) {
  */
 function system_get_info($type, $name = NULL) {
   if ($type == 'module') {
-    $info = &drupal_static(__FUNCTION__);
-    if (!isset($info)) {
-      if ($cache = \Drupal::cache()->get('system.module.info')) {
-        $info = $cache->data;
-      }
-      else {
-        $data = system_rebuild_module_data();
-        foreach (\Drupal::moduleHandler()->getModuleList() as $module => $filename) {
-          if (isset($data[$module])) {
-            $info[$module] = $data[$module]->info;
-          }
-        }
-        // Store the module information in cache. This cache is cleared by
-        // calling system_rebuild_module_data(), for example, when listing
-        // modules, (un)installing modules, importing configuration, updating
-        // the site and when flushing all the caches.
-        \Drupal::cache()->set('system.module.info', $info);
-      }
-    }
+    return \Drupal::service('module_listing')->getInfo($name);
   }
   else {
+    // @todo
     $info = array();
     $list = system_list($type);
     foreach ($list as $shortname => $item) {
@@ -916,11 +899,11 @@ function system_get_info($type, $name = NULL) {
         $info[$shortname] = $item->info;
       }
     }
+    if (isset($name)) {
+      return isset($info[$name]) ? $info[$name] : array();
+    }
+    return $info;
   }
-  if (isset($name)) {
-    return isset($info[$name]) ? $info[$name] : array();
-  }
-  return $info;
 }
 
 /**
@@ -930,105 +913,7 @@ function system_get_info($type, $name = NULL) {
  *   An associative array of module information.
  */
 function _system_rebuild_module_data() {
-  $listing = new ExtensionDiscovery(\Drupal::root());
-
-  // Find installation profiles. This needs to happen before performing a
-  // module scan as the module scan requires knowing what the active profile is.
-  // @todo Remove as part of https://www.drupal.org/node/2186491.
-  $profiles = $listing->scan('profile');
-  $profile = drupal_get_profile();
-  if ($profile && isset($profiles[$profile])) {
-    // Prime the drupal_get_filename() static cache with the profile info file
-    // location so we can use drupal_get_path() on the active profile during
-    // the module scan.
-    // @todo Remove as part of https://www.drupal.org/node/2186491.
-    drupal_get_filename('profile', $profile, $profiles[$profile]->getPathname());
-  }
-
-  // Find modules.
-  $modules = $listing->scan('module');
-  // Include the installation profile in modules that are loaded.
-  if ($profile) {
-    $modules[$profile] = $profiles[$profile];
-    // Installation profile hooks are always executed last.
-    $modules[$profile]->weight = 1000;
-  }
-
-  // Set defaults for module info.
-  $defaults = array(
-    'dependencies' => array(),
-    'description' => '',
-    'package' => 'Other',
-    'version' => NULL,
-    'php' => DRUPAL_MINIMUM_PHP,
-  );
-
-  // Read info files for each module.
-  foreach ($modules as $key => $module) {
-    // Look for the info file.
-    $module->info = \Drupal::service('info_parser')->parse($module->getPathname());
-
-    // Add the info file modification time, so it becomes available for
-    // contributed modules to use for ordering module lists.
-    $module->info['mtime'] = $module->getMTime();
-
-    // Merge in defaults and save.
-    $modules[$key]->info = $module->info + $defaults;
-
-    // Installation profiles are hidden by default, unless explicitly specified
-    // otherwise in the .info.yml file.
-    if ($key == $profile && !isset($modules[$key]->info['hidden'])) {
-      $modules[$key]->info['hidden'] = TRUE;
-    }
-
-    // Invoke hook_system_info_alter() to give installed modules a chance to
-    // modify the data in the .info.yml files if necessary.
-    // @todo Remove $type argument, obsolete with $module->getType().
-    $type = 'module';
-    \Drupal::moduleHandler()->alter('system_info', $modules[$key]->info, $modules[$key], $type);
-  }
-
-  // It is possible that a module was marked as required by
-  // hook_system_info_alter() and modules that it depends on are not required.
-  foreach ($modules as $module) {
-    _system_rebuild_module_data_ensure_required($module, $modules);
-  }
-
-
-  if ($profile && isset($modules[$profile])) {
-    // The installation profile is required, if it's a valid module.
-    $modules[$profile]->info['required'] = TRUE;
-    // Add a default distribution name if the profile did not provide one.
-    // @see install_profile_info()
-    // @see drupal_install_profile_distribution_name()
-    if (!isset($modules[$profile]->info['distribution']['name'])) {
-      $modules[$profile]->info['distribution']['name'] = 'Drupal';
-    }
-  }
-
-  return $modules;
-}
-
-/**
- * Ensures that dependencies of required modules are also required.
- *
- * @param \Drupal\Core\Extension\Extension $module
- *   The module info.
- * @param \Drupal\Core\Extension\Extension[] $modules
- *   The array of all module info.
- */
-function _system_rebuild_module_data_ensure_required($module, &$modules) {
-  if (!empty($module->info['required'])) {
-    foreach ($module->info['dependencies'] as $dependency) {
-      $dependency_name = ModuleHandler::parseDependency($dependency)['name'];
-      if (!isset($modules[$dependency_name]->info['required'])) {
-        $modules[$dependency_name]->info['required'] = TRUE;
-        $modules[$dependency_name]->info['explanation'] = t('Dependency of required module @module', array('@module' => $module->info['name']));
-        // Ensure any dependencies it has are required.
-        _system_rebuild_module_data_ensure_required($modules[$dependency_name], $modules);
-      }
-    }
-  }
+  return \Drupal::service('module_listing')->reset()->listExtensions();
 }
 
 /**
@@ -1038,33 +923,7 @@ function _system_rebuild_module_data_ensure_required($module, &$modules) {
  *   Array of all available modules and their data.
  */
 function system_rebuild_module_data() {
-  $modules_cache = &drupal_static(__FUNCTION__);
-  // Only rebuild once per request. $modules and $modules_cache cannot be
-  // combined into one variable, because the $modules_cache variable is reset by
-  // reference from system_list_reset() during the rebuild.
-  if (!isset($modules_cache)) {
-    $modules = _system_rebuild_module_data();
-    $files = array();
-    ksort($modules);
-    // Add status, weight, and schema version.
-    $installed_modules = \Drupal::config('core.extension')->get('module') ?: array();
-    foreach ($modules as $name => $module) {
-      $module->weight = isset($installed_modules[$name]) ? $installed_modules[$name] : 0;
-      $module->status = (int) isset($installed_modules[$name]);
-      $module->schema_version = SCHEMA_UNINSTALLED;
-      $files[$name] = $module->getPathname();
-    }
-    $modules = \Drupal::moduleHandler()->buildModuleDependencies($modules);
-    $modules_cache = $modules;
-
-    // Store filenames to allow drupal_get_filename() to retrieve them without
-    // having to rebuild or scan the filesystem.
-    \Drupal::state()->set('system.module.files', $files);
-    // Clear the module info cache.
-    \Drupal::cache()->delete('system.module.info');
-    drupal_static_reset('system_get_info');
-  }
-  return $modules_cache;
+  return \Drupal::service('module_listing')->reset()->listExtensions();
 }
 
 /**
diff --git a/core/modules/system/tests/src/Kernel/Extension/ModuleHandlerTest.php b/core/modules/system/tests/src/Kernel/Extension/ModuleHandlerTest.php
index 5265b8e..413f912 100644
--- a/core/modules/system/tests/src/Kernel/Extension/ModuleHandlerTest.php
+++ b/core/modules/system/tests/src/Kernel/Extension/ModuleHandlerTest.php
@@ -119,7 +119,7 @@ function testDependencyResolution() {
     // Color will depend on Config, which depends on a non-existing module Foo.
     // Nothing should be installed.
     \Drupal::state()->set('module_test.dependency', 'missing dependency');
-    drupal_static_reset('system_rebuild_module_data');
+    \Drupal::service('module_listing')->reset();
 
     try {
       $result = $this->moduleInstaller()->install(array('color'));
@@ -134,7 +134,7 @@ function testDependencyResolution() {
     // Fix the missing dependency.
     // Color module depends on Config. Config depends on Help module.
     \Drupal::state()->set('module_test.dependency', 'dependency');
-    drupal_static_reset('system_rebuild_module_data');
+    \Drupal::service('module_listing')->reset();
 
     $result = $this->moduleInstaller()->install(array('color'));
     $this->assertTrue($result, 'ModuleHandler::install() returns the correct value.');
@@ -166,7 +166,7 @@ function testDependencyResolution() {
     // dependency on a specific version of Help module in its info file. Make
     // sure that Drupal\Core\Extension\ModuleHandler::install() still works.
     \Drupal::state()->set('module_test.dependency', 'version dependency');
-    drupal_static_reset('system_rebuild_module_data');
+    \Drupal::service('module_listing')->reset();
 
     $result = $this->moduleInstaller()->install(array('color'));
     $this->assertTrue($result, 'ModuleHandler::install() returns the correct value.');
@@ -196,8 +196,7 @@ function testUninstallProfileDependency() {
     drupal_get_filename('profile', $profile, 'core/profiles/' . $profile . '/' . $profile . '.info.yml');
     $this->enableModules(array('module_test', $profile));
 
-    drupal_static_reset('system_rebuild_module_data');
-    $data = system_rebuild_module_data();
+    $data = \Drupal::service('module_listing')->reset()->listExtensions();
     $this->assertTrue(isset($data[$profile]->requires[$dependency]));
 
     $this->moduleInstaller()->install(array($dependency));
@@ -235,7 +234,7 @@ function testUninstallContentDependency() {
     // entity_test will depend on help. This way help can not be uninstalled
     // when there is test content preventing entity_test from being uninstalled.
     \Drupal::state()->set('module_test.dependency', 'dependency');
-    drupal_static_reset('system_rebuild_module_data');
+    \Drupal::service('module_listing')->reset();
 
     // Create an entity so that the modules can not be disabled.
     $entity = entity_create('entity_test', array('name' => $this->randomString()));