diff -u b/admin_menu.inc b/admin_menu.inc
--- b/admin_menu.inc
+++ b/admin_menu.inc
@@ -1,5 +1,6 @@
 <?php
 
+use Drupal\Core\Render\Element;
 /**
  * @file
  * Menu builder functions for Administration menu.
@@ -407,7 +408,7 @@
       // Automatically hide empty categories.
       // Check for empty children first for performance. Only when non-empty
       // (typically 'admin/config'), check whether children are accessible.
-      if (empty($children) || !element_get_visible_children($children)) {
+      if (empty($children) || !Element::getVisibleChildren($children)) {
         $links[$data['link']['href']]['#access'] = FALSE;
       }
     }
@@ -440,7 +441,7 @@
   $links['icon']['cron'] = array(
     '#title' => t('Run cron'),
     '#weight' => 50,
-    '#access' => user_access('administer site configuration'),
+    '#access' => \Drupal::currentUser()->hasPermission('administer site configuration'),
     '#href' => 'admin/reports/status/run-cron',
     '#options' => array(
       'query' => $destination,
@@ -451,7 +452,7 @@
     '#title' => t('Run updates'),
     '#weight' => 50,
     // @see update_access_allowed()
-    '#access' => $GLOBALS['user']->uid == 1 || !empty($GLOBALS['update_free_access']) || user_access('administer software updates'),
+    '#access' => $GLOBALS['user']->uid == 1 || !empty($GLOBALS['update_free_access']) || \Drupal::currentUser()->hasPermission('administer software updates'),
     '#href' => base_path() . 'update.php',
     '#options' => array(
       'external' => TRUE,
@@ -461,12 +462,12 @@
   $links['icon']['drupal.org'] = array(
     '#title' => 'Drupal.org',
     '#weight' => 100,
-    '#access' => user_access('display drupal links'),
+    '#access' => \Drupal::currentUser()->hasPermission('display drupal links'),
     '#href' => 'http://drupal.org',
   );
   // Add links to project issue queues.
-  foreach (module_list() as $module) {
-    $info = drupal_parse_info_file(drupal_get_path('module', $module) . '/' . $module . '.info.yml');
+  foreach (\Drupal::moduleHandler()->getModuleList() as $module_name => $module) {
+    $info =  drupal_parse_info_file($module->getPath() . '/' . $module_name . '.info.yml');
     if (!isset($info['project']) || isset($links['icon']['drupal.org'][$info['project']])) {
       continue;
     }
@@ -483,7 +484,7 @@
   $links['icon']['flush-cache'] = array(
     '#title' => t('Flush all caches'),
     '#weight' => 20,
-    '#access' => user_access('flush caches'),
+    '#access' => \Drupal::currentUser()->hasPermission('flush caches'),
     '#href' => 'admin_menu/flush-cache',
     '#options' => array(
       'query' => $destination + array('token' => drupal_get_token('admin_menu/flush-cache')),
@@ -501,10 +502,10 @@
   }
 
   // Add Devel module menu links.
-  if (module_exists('devel')) {
+  if (\Drupal::moduleHandler()->moduleExists('devel')) {
     $devel_tree = menu_build_tree('devel');
     $devel_links = admin_menu_links_menu($devel_tree);
-    if (element_get_visible_children($devel_links)) {
+    if (Element::getVisibleChildren($devel_links)) {
       $links['icon']['devel'] = array(
         '#title' => t('Development'),
         '#weight' => 30,
@@ -527,7 +528,7 @@
     '#weight' => 100,
   );
   $links['account'] = array(
-    '#title' => user_format_name($GLOBALS['user']),
+    '#title' => \Drupal::currentUser()->getUsername(),
     '#weight' => -99,
     '#attributes' => array('class' => array('admin-menu-action', 'admin-menu-account')),
     '#href' => 'user/' . $GLOBALS['user']->uid,
@@ -539,8 +540,8 @@
     '#href' => 'user/logout',
   );
   // Add Devel module switch user links.
-  if (!module_exists('masquerade')) {
-    $switch_links = module_invoke('devel', 'switch_user_list');
+  if (!\Drupal::moduleHandler()->moduleExists('masquerade')) {
+    $switch_links = \Drupal::moduleHandler()->invoke('devel', 'switch_user_list');
     if (!empty($switch_links) && count($switch_links) > 1) {
       foreach ($switch_links as $uid => $link) {
         $links['account'][$uid] = array(
@@ -575,7 +576,7 @@
     '#description' => t('Current anonymous / authenticated users'),
     '#weight' => -90,
     '#attributes' => array('class' => array('admin-menu-action', 'admin-menu-users')),
-    '#href' => (user_access('administer users') ? 'admin/people/people' : 'user'),
+    '#href' => (\Drupal::currentUser()->hasPermission('administer users') ? 'admin/people/people' : 'user'),
   );
   return $links;
 }
@@ -853,14 +854,14 @@
       break;
 
     case 'bootstrap':
-      cache('bootstrap')->deleteAll();
-      cache('config')->deleteAll();
+      \Drupal::cache('bootstrap')->deleteAll();
+      \Drupal::cache('config')->deleteAll();
       break;
 
     case 'cache':
       // @see drupal_flush_all_caches()
       foreach (\Drupal::moduleHandler()->invokeAll('cache_flush') as $bin) {
-        cache($bin)->deleteAll();
+        \Drupal::cache($bin)->deleteAll();
       }
       break;
 
@@ -868,16 +869,16 @@
       // Change query-strings on css/js files to enforce reload for all users.
       _drupal_flush_css_js();
 
-      drupal_clear_css_cache();
-      drupal_clear_js_cache();
+      \Drupal::service('asset.css.collection_optimizer')->deleteAll();
+      \Drupal::service('asset.js.collection_optimizer')->deleteAll();
 
       // Clear the page cache, since cached HTML pages might link to old CSS and
       // JS aggregates.
-      cache('page')->deleteAll();
+      \Drupal::cache('page')->deleteAll();
       break;
 
     case 'theme':
-      system_rebuild_theme_data();
+      \Drupal::service('theme_handler')->rebuildThemeData();
       drupal_theme_rebuild();
       break;
   }
diff -u b/admin_menu.module b/admin_menu.module
--- b/admin_menu.module
+++ b/admin_menu.module
@@ -173,27 +173,14 @@
  * Implements hook_page_bottom().
  */
 function admin_menu_page_bottom(array &$page_bottom) {
-  if (!\Drupal::currentUser()->hasPermission('access administration menu')) {
-    return;
-  }
-
-  if (admin_menu_suppress(FALSE)) {
-    $page_bottom['admin_menu_suppress'] = [
-      '#attached' => [
-        'drupalSettings' => [
-          'admin_menu' => ['suppress' => 1],
-        ],
-      ],
-    ];
+  if (!user_access('access administration menu') || admin_menu_suppress(FALSE)) {
     return;
   }
-
-  // Performance: Skip this entirely for non-HTML requests.
-  $request_format = \Drupal::service('request_stack')->getCurrentRequest()->getRequestFormat();
-  if ($request_format != 'html') {
+  // Performance: Skip this entirely for AJAX requests.
+  $current_path = current_path();
+  if (strpos($current_path, 'js/') === 0) {
     return;
   }
-
   global $user;
   $path = drupal_get_path('module', 'admin_menu');
 
@@ -219,14 +206,27 @@
  * Implements hook_page_bottom().
  */
 function admin_menu_page_bottom(array &$page_bottom) {
-  if (!user_access('access administration menu') || admin_menu_suppress(FALSE)) {
+  if (!\Drupal::currentUser()->hasPermission('access administration menu')) {
     return;
   }
-  // Performance: Skip this entirely for AJAX requests.
-  $current_path = current_path();
-  if (strpos($current_path, 'js/') === 0) {
+
+  if (admin_menu_suppress(FALSE)) {
+    $page_bottom['admin_menu_suppress'] = [
+      '#attached' => [
+        'drupalSettings' => [
+          'admin_menu' => ['suppress' => 1],
+        ],
+      ],
+    ];
+    return;
+  }
+
+  // Performance: Skip this entirely for non-HTML requests.
+  $request_format = \Drupal::service('request_stack')->getCurrentRequest()->getRequestFormat();
+  if ($request_format != 'html') {
     return;
   }
+
   global $user;
   $path = drupal_get_path('module', 'admin_menu');
 
only in patch2:
unchanged:
--- a/admin_menu.api.php
+++ b/admin_menu.api.php
@@ -92,7 +92,7 @@ function hook_admin_menu_output_build(&$content) {
   if (isset($content['icon'])) {
     $content['icon']['myitem']['cron'] = array(
       '#title' => t('Run cron'),
-      '#access' => user_access('administer site configuration'),
+      '#access' => \Drupal::currentUser()->hasPermission('administer site configuration'),
       '#href' => 'admin/reports/status/run-cron',
     );
   }