Merge pull request #16935 from owncloud/allow-app-check-code-for-deprecated-classes

Allow app check code for deprecated classes

9 files changed, 889 insertions, 166 deletions

diff --git a/lib/private/app/codechecker/abstractcheck.php b/lib/private/app/codechecker/abstractcheck.php
new file mode 100644
index 00000000000..c1c6524e42f
--- /dev/null
+++ b/lib/private/app/codechecker/abstractcheck.php
@@ -0,0 +1,139 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\App\CodeChecker;
+
+abstract class AbstractCheck implements ICheck {
+	/** @var ICheck */
+	protected $check;
+
+	/**
+	 * @param ICheck $check
+	 */
+	public function __construct(ICheck $check) {
+		$this->check = $check;
+	}
+
+	/**
+	 * @param int $errorCode
+	 * @param string $errorObject
+	 * @return string
+	 */
+	public function getDescription($errorCode, $errorObject) {
+		switch ($errorCode) {
+			case CodeChecker::STATIC_CALL_NOT_ALLOWED:
+				$functions = $this->getLocalFunctions();
+				$functions = array_change_key_case($functions, CASE_LOWER);
+				if (isset($functions[$errorObject])) {
+					return $this->getLocalDescription();
+				}
+			// no break;
+			case CodeChecker::CLASS_EXTENDS_NOT_ALLOWED:
+			case CodeChecker::CLASS_IMPLEMENTS_NOT_ALLOWED:
+			case CodeChecker::CLASS_NEW_NOT_ALLOWED:
+			case CodeChecker::CLASS_USE_NOT_ALLOWED:
+				$classes = $this->getLocalClasses();
+				$classes = array_change_key_case($classes, CASE_LOWER);
+				if (isset($classes[$errorObject])) {
+					return $this->getLocalDescription();
+				}
+			break;
+
+			case CodeChecker::CLASS_CONST_FETCH_NOT_ALLOWED:
+				$constants = $this->getLocalConstants();
+				$constants = array_change_key_case($constants, CASE_LOWER);
+				if (isset($constants[$errorObject])) {
+					return $this->getLocalDescription();
+				}
+			break;
+
+			case CodeChecker::CLASS_METHOD_CALL_NOT_ALLOWED:
+				$methods = $this->getLocalMethods();
+				$methods = array_change_key_case($methods, CASE_LOWER);
+				if (isset($methods[$errorObject])) {
+					return $this->getLocalDescription();
+				}
+			break;
+		}
+
+		return $this->check->getDescription($errorCode, $errorObject);
+	}
+
+	/**
+	 * @return string
+	 */
+	abstract protected function getLocalDescription();
+
+	/**
+	 * @return array
+	 */
+	abstract protected function getLocalClasses();
+
+	/**
+	 * @return array
+	 */
+	abstract protected function getLocalConstants();
+
+	/**
+	 * @return array
+	 */
+	abstract protected function getLocalFunctions();
+
+	/**
+	 * @return array
+	 */
+	abstract protected function getLocalMethods();
+
+	/**
+	 * @return array E.g.: `'ClassName' => 'oc version',`
+	 */
+	public function getClasses() {
+		return array_merge($this->getLocalClasses(), $this->check->getClasses());
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName::CONSTANT_NAME' => 'oc version',`
+	 */
+	public function getConstants() {
+		return array_merge($this->getLocalConstants(), $this->check->getConstants());
+	}
+
+	/**
+	 * @return array E.g.: `'functionName' => 'oc version',`
+	 */
+	public function getFunctions() {
+		return array_merge($this->getLocalFunctions(), $this->check->getFunctions());
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName::methodName' => 'oc version',`
+	 */
+	public function getMethods() {
+		return array_merge($this->getLocalMethods(), $this->check->getMethods());
+	}
+
+	/**
+	 * @return bool
+	 */
+	public function checkStrongComparisons() {
+		return $this->check->checkStrongComparisons();
+	}
+}
diff --git a/lib/private/app/codechecker.php b/lib/private/app/codechecker/codechecker.php
index 3f6cd19d6b4..ef7dc7f3e4d 100644
--- a/lib/private/app/codechecker.php
+++ b/lib/private/app/codechecker/codechecker.php
@@ -21,14 +21,13 @@
  *
  */
 
-namespace OC\App;
+namespace OC\App\CodeChecker;
 
 use OC\Hooks\BasicEmitter;
 use PhpParser\Lexer;
 use PhpParser\Node;
 use PhpParser\Node\Name;
 use PhpParser\NodeTraverser;
-use PhpParser\NodeVisitorAbstract;
 use PhpParser\Parser;
 use RecursiveCallbackFilterIterator;
 use RecursiveDirectoryIterator;
@@ -42,43 +41,20 @@ class CodeChecker extends BasicEmitter {
 	const CLASS_IMPLEMENTS_NOT_ALLOWED = 1001;
 	const STATIC_CALL_NOT_ALLOWED = 1002;
 	const CLASS_CONST_FETCH_NOT_ALLOWED = 1003;
-	const CLASS_NEW_FETCH_NOT_ALLOWED =  1004;
+	const CLASS_NEW_NOT_ALLOWED =  1004;
 	const OP_OPERATOR_USAGE_DISCOURAGED =  1005;
+	const CLASS_USE_NOT_ALLOWED =  1006;
+	const CLASS_METHOD_CALL_NOT_ALLOWED =  1007;
 
 	/** @var Parser */
 	private $parser;
 
-	/** @var string[] */
-	private $blackListedClassNames;
+	/** @var ICheck */
+	protected $checkList;
 
-	public function __construct() {
+	public function __construct(ICheck $checkList) {
+		$this->checkList = $checkList;
 		$this->parser = new Parser(new Lexer);
-		$this->blackListedClassNames = [
-			// classes replaced by the public api
-			'OC_API',
-			'OC_App',
-			'OC_AppConfig',
-			'OC_Avatar',
-			'OC_BackgroundJob',
-			'OC_Config',
-			'OC_DB',
-			'OC_Files',
-			'OC_Helper',
-			'OC_Hook',
-			'OC_Image',
-			'OC_JSON',
-			'OC_L10N',
-			'OC_Log',
-			'OC_Mail',
-			'OC_Preferences',
-			'OC_Search_Provider',
-			'OC_Search_Result',
-			'OC_Request',
-			'OC_Response',
-			'OC_Template',
-			'OC_User',
-			'OC_Util',
-		];
 	}
 
 	/**
@@ -138,7 +114,7 @@ class CodeChecker extends BasicEmitter {
 		$code = file_get_contents($file);
 		$statements = $this->parser->parse($code);
 
-		$visitor = new CodeCheckVisitor($this->blackListedClassNames);
+		$visitor = new NodeVisitor($this->checkList);
 		$traverser = new NodeTraverser;
 		$traverser->addVisitor($visitor);
 
diff --git a/lib/private/app/codechecker/deprecationcheck.php b/lib/private/app/codechecker/deprecationcheck.php
new file mode 100644
index 00000000000..3b6dc968bb5
--- /dev/null
+++ b/lib/private/app/codechecker/deprecationcheck.php
@@ -0,0 +1,147 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\App\CodeChecker;
+
+class DeprecationCheck extends AbstractCheck implements ICheck {
+	/**
+	 * @return string
+	 */
+	protected function getLocalDescription() {
+		return 'deprecated';
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName' => 'oc version',`
+	 */
+	protected function getLocalClasses() {
+		return [
+			'OCP\Config' => '8.0.0',
+			'OCP\Contacts' => '8.1.0',
+			'OCP\DB' => '8.1.0',
+			'OCP\IHelper' => '8.1.0',
+			'OCP\JSON' => '8.1.0',
+			'OCP\Response' => '8.1.0',
+			'OCP\AppFramework\IApi' => '8.0.0',
+		];
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName::CONSTANT_NAME' => 'oc version',`
+	 */
+	protected function getLocalConstants() {
+		return [
+			'OCP::PERMISSION_CREATE' => '8.0.0',
+			'OCP::PERMISSION_READ' => '8.0.0',
+			'OCP::PERMISSION_UPDATE' => '8.0.0',
+			'OCP::PERMISSION_DELETE' => '8.0.0',
+			'OCP::PERMISSION_SHARE' => '8.0.0',
+			'OCP::PERMISSION_ALL' => '8.0.0',
+			'OCP::FILENAME_INVALID_CHARS' => '8.0.0',
+		];
+	}
+
+	/**
+	 * @return array E.g.: `'functionName' => 'oc version',`
+	 */
+	protected function getLocalFunctions() {
+		return [
+			'OCP::image_path' => '8.0.0',
+			'OCP::mimetype_icon' => '8.0.0',
+			'OCP::preview_icon' => '8.0.0',
+			'OCP::publicPreview_icon' => '8.0.0',
+			'OCP::human_file_size' => '8.0.0',
+			'OCP::relative_modified_date' => '8.0.0',
+			'OCP::simple_file_size' => '8.0.0',
+			'OCP::html_select_options' => '8.0.0',
+		];
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName::methodName' => 'oc version',`
+	 */
+	protected function getLocalMethods() {
+		return [
+			'OCP\App::register' => '8.1.0',
+			'OCP\App::addNavigationEntry' => '8.1.0',
+			'OCP\App::setActiveNavigationEntry' => '8.1.0',
+
+			'OCP\AppFramework\Controller::params' => '7.0.0',
+			'OCP\AppFramework\Controller::getParams' => '7.0.0',
+			'OCP\AppFramework\Controller::method' => '7.0.0',
+			'OCP\AppFramework\Controller::getUploadedFile' => '7.0.0',
+			'OCP\AppFramework\Controller::env' => '7.0.0',
+			'OCP\AppFramework\Controller::cookie' => '7.0.0',
+			'OCP\AppFramework\Controller::render' => '7.0.0',
+
+			'OCP\AppFramework\IAppContainer::getCoreApi' => '8.0.0',
+			'OCP\AppFramework\IAppContainer::isLoggedIn' => '8.0.0',
+			'OCP\AppFramework\IAppContainer::isAdminUser' => '8.0.0',
+			'OCP\AppFramework\IAppContainer::log' => '8.0.0',
+
+			'OCP\BackgroundJob::addQueuedTask' => '6.0.0',
+			'OCP\BackgroundJob::addRegularTask' => '6.0.0',
+			'OCP\BackgroundJob::allQueuedTasks' => '6.0.0',
+			'OCP\BackgroundJob::allRegularTasks' => '6.0.0',
+			'OCP\BackgroundJob::deleteQueuedTask' => '6.0.0',
+			'OCP\BackgroundJob::findQueuedTask' => '6.0.0',
+			'OCP\BackgroundJob::queuedTaskWhereAppIs' => '6.0.0',
+			'OCP\BackgroundJob::registerJob' => '8.1.0',
+
+			'OCP\Files::tmpFile' => '8.1.0',
+			'OCP\Files::tmpFolder' => '8.1.0',
+
+			'OCP\IAppConfig::getValue' => '8.0.0',
+			'OCP\IAppConfig::deleteKey' => '8.0.0',
+			'OCP\IAppConfig::getKeys' => '8.0.0',
+			'OCP\IAppConfig::setValue' => '8.0.0',
+			'OCP\IAppConfig::deleteApp' => '8.0.0',
+
+			'OCP\ISearch::search' => '8.0.0',
+
+			'OCP\IServerContainer::getDb' => '8.1.0',
+			'OCP\IServerContainer::getHTTPHelper' => '8.1.0',
+
+			'OCP\User::getUser' => '8.0.0',
+			'OCP\User::getUsers' => '8.1.0',
+			'OCP\User::getDisplayName' => '8.1.0',
+			'OCP\User::getDisplayNames' => '8.1.0',
+			'OCP\User::userExists' => '8.1.0',
+			'OCP\User::logout' => '8.1.0',
+			'OCP\User::checkPassword' => '8.1.0',
+
+			'OCP\Util::sendMail' => '8.1.0',
+			'OCP\Util::formatDate' => '8.0.0',
+			'OCP\Util::encryptedFiles' => '8.1.0',
+			'OCP\Util::linkToRoute' => '8.1.0',
+			'OCP\Util::linkTo' => '8.1.0',
+			'OCP\Util::getServerHost' => '8.1.0',
+			'OCP\Util::getServerProtocol' => '8.1.0',
+			'OCP\Util::getRequestUri' => '8.1.0',
+			'OCP\Util::getScriptName' => '8.1.0',
+			'OCP\Util::imagePath' => '8.1.0',
+			'OCP\Util::isValidFileName' => '8.1.0',
+			'OCP\Util::generateRandomBytes' => '8.1.0',
+			'OCP\Util::mb_str_replace' => '8.2.0',
+			'OCP\Util::mb_substr_replace' => '8.2.0',
+		];
+	}
+}
diff --git a/lib/private/app/codechecker/emptycheck.php b/lib/private/app/codechecker/emptycheck.php
new file mode 100644
index 00000000000..0e5df55d090
--- /dev/null
+++ b/lib/private/app/codechecker/emptycheck.php
@@ -0,0 +1,67 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OC\App\CodeChecker;
+
+class EmptyCheck implements ICheck {
+	/**
+	 * @param int $errorCode
+	 * @param string $errorObject
+	 * @return string
+	 */
+	public function getDescription($errorCode, $errorObject) {
+		return '';
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName' => 'oc version',`
+	 */
+	public function getClasses() {
+		return [];
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName::CONSTANT_NAME' => 'oc version',`
+	 */
+	public function getConstants() {
+		return [];
+	}
+
+	/**
+	 * @return array E.g.: `'functionName' => 'oc version',`
+	 */
+	public function getFunctions() {
+		return [];
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName::methodName' => 'oc version',`
+	 */
+	public function getMethods() {
+		return [];
+	}
+
+	/**
+	 * @return bool
+	 */
+	public function checkStrongComparisons() {
+		return false;
+	}
+}
diff --git a/lib/private/app/codechecker/icheck.php b/lib/private/app/codechecker/icheck.php
new file mode 100644
index 00000000000..a00e0d8fa13
--- /dev/null
+++ b/lib/private/app/codechecker/icheck.php
@@ -0,0 +1,55 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OC\App\CodeChecker;
+
+interface ICheck {
+	/**
+	 * @param int $errorCode
+	 * @param string $errorObject
+	 * @return string
+	 */
+	public function getDescription($errorCode, $errorObject);
+
+	/**
+	 * @return array E.g.: `'ClassName' => 'oc version',`
+	 */
+	public function getClasses();
+
+	/**
+	 * @return array E.g.: `'ClassName::CONSTANT_NAME' => 'oc version',`
+	 */
+	public function getConstants();
+
+	/**
+	 * @return array E.g.: `'functionName' => 'oc version',`
+	 */
+	public function getFunctions();
+
+	/**
+	 * @return array E.g.: `'ClassName::methodName' => 'oc version',`
+	 */
+	public function getMethods();
+
+	/**
+	 * @return bool
+	 */
+	public function checkStrongComparisons();
+}
diff --git a/lib/private/app/codechecker/nodevisitor.php b/lib/private/app/codechecker/nodevisitor.php
new file mode 100644
index 00000000000..a22f852f36a
--- /dev/null
+++ b/lib/private/app/codechecker/nodevisitor.php
@@ -0,0 +1,306 @@
+<?php
+/**
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\App\CodeChecker;
+
+use PhpParser\Node;
+use PhpParser\Node\Name;
+use PhpParser\NodeVisitorAbstract;
+
+class NodeVisitor extends NodeVisitorAbstract {
+	/** @var ICheck */
+	protected $list;
+
+	/** @var string */
+	protected $blackListDescription;
+	/** @var string[] */
+	protected $blackListedClassNames;
+	/** @var string[] */
+	protected $blackListedConstants;
+	/** @var string[] */
+	protected $blackListedFunctions;
+	/** @var string[] */
+	protected $blackListedMethods;
+	/** @var bool */
+	protected $checkEqualOperatorUsage;
+	/** @var string[] */
+	protected $errorMessages;
+
+	/**
+	 * @param ICheck $list
+	 */
+	public function __construct(ICheck $list) {
+		$this->list = $list;
+
+		$this->blackListedClassNames = [];
+		foreach ($list->getClasses() as $class => $blackListInfo) {
+			if (is_numeric($class) && is_string($blackListInfo)) {
+				$class = $blackListInfo;
+				$blackListInfo = null;
+			}
+
+			$class = strtolower($class);
+			$this->blackListedClassNames[$class] = $class;
+		}
+
+		$this->blackListedConstants = [];
+		foreach ($list->getConstants() as $constantName => $blackListInfo) {
+			$constantName = strtolower($constantName);
+			$this->blackListedConstants[$constantName] = $constantName;
+		}
+
+		$this->blackListedFunctions = [];
+		foreach ($list->getFunctions() as $functionName => $blackListInfo) {
+			$functionName = strtolower($functionName);
+			$this->blackListedFunctions[$functionName] = $functionName;
+		}
+
+		$this->blackListedMethods = [];
+		foreach ($list->getMethods() as $functionName => $blackListInfo) {
+			$functionName = strtolower($functionName);
+			$this->blackListedMethods[$functionName] = $functionName;
+		}
+
+		$this->checkEqualOperatorUsage = $list->checkStrongComparisons();
+
+		$this->errorMessages = [
+			CodeChecker::CLASS_EXTENDS_NOT_ALLOWED => "%s class must not be extended",
+			CodeChecker::CLASS_IMPLEMENTS_NOT_ALLOWED => "%s interface must not be implemented",
+			CodeChecker::STATIC_CALL_NOT_ALLOWED => "Static method of %s class must not be called",
+			CodeChecker::CLASS_CONST_FETCH_NOT_ALLOWED => "Constant of %s class must not not be fetched",
+			CodeChecker::CLASS_NEW_NOT_ALLOWED => "%s class must not be instantiated",
+			CodeChecker::CLASS_USE_NOT_ALLOWED => "%s class must not be imported with a use statement",
+			CodeChecker::CLASS_METHOD_CALL_NOT_ALLOWED => "Method of %s class must not be called",
+
+			CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED => "is discouraged",
+		];
+	}
+
+	/** @var array */
+	public $errors = [];
+
+	public function enterNode(Node $node) {
+		if ($this->checkEqualOperatorUsage && $node instanceof Node\Expr\BinaryOp\Equal) {
+			$this->errors[]= [
+				'disallowedToken' => '==',
+				'errorCode' => CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED,
+				'line' => $node->getLine(),
+				'reason' => $this->buildReason('==', CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED)
+			];
+		}
+		if ($this->checkEqualOperatorUsage && $node instanceof Node\Expr\BinaryOp\NotEqual) {
+			$this->errors[]= [
+				'disallowedToken' => '!=',
+				'errorCode' => CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED,
+				'line' => $node->getLine(),
+				'reason' => $this->buildReason('!=', CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED)
+			];
+		}
+		if ($node instanceof Node\Stmt\Class_) {
+			if (!is_null($node->extends)) {
+				$this->checkBlackList($node->extends->toString(), CodeChecker::CLASS_EXTENDS_NOT_ALLOWED, $node);
+			}
+			foreach ($node->implements as $implements) {
+				$this->checkBlackList($implements->toString(), CodeChecker::CLASS_IMPLEMENTS_NOT_ALLOWED, $node);
+			}
+		}
+		if ($node instanceof Node\Expr\StaticCall) {
+			if (!is_null($node->class)) {
+				if ($node->class instanceof Name) {
+					$this->checkBlackList($node->class->toString(), CodeChecker::STATIC_CALL_NOT_ALLOWED, $node);
+
+					$this->checkBlackListFunction($node->class->toString(), $node->name, $node);
+					$this->checkBlackListMethod($node->class->toString(), $node->name, $node);
+				}
+
+				if ($node->class instanceof Node\Expr\Variable) {
+					/**
+					 * TODO: find a way to detect something like this:
+					 *       $c = "OC_API";
+					 *       $n = $c::call();
+					 */
+					// $this->checkBlackListMethod($node->class->..., $node->name, $node);
+				}
+			}
+		}
+		if ($node instanceof Node\Expr\MethodCall) {
+			if (!is_null($node->var)) {
+				if ($node->var instanceof Node\Expr\Variable) {
+					/**
+					 * TODO: find a way to detect something like this:
+					 *       $c = new OC_API();
+					 *       $n = $c::call();
+					 *       $n = $c->call();
+					 */
+					// $this->checkBlackListMethod($node->var->..., $node->name, $node);
+				}
+			}
+		}
+		if ($node instanceof Node\Expr\ClassConstFetch) {
+			if (!is_null($node->class)) {
+				if ($node->class instanceof Name) {
+					$this->checkBlackList($node->class->toString(), CodeChecker::CLASS_CONST_FETCH_NOT_ALLOWED, $node);
+				}
+				if ($node->class instanceof Node\Expr\Variable) {
+					/**
+					 * TODO: find a way to detect something like this:
+					 *       $c = "OC_API";
+					 *       $n = $i::ADMIN_AUTH;
+					 */
+				}
+
+				$this->checkBlackListConstant($node->class->toString(), $node->name, $node);
+			}
+		}
+		if ($node instanceof Node\Expr\New_) {
+			if (!is_null($node->class)) {
+				if ($node->class instanceof Name) {
+					$this->checkBlackList($node->class->toString(), CodeChecker::CLASS_NEW_NOT_ALLOWED, $node);
+				}
+				if ($node->class instanceof Node\Expr\Variable) {
+					/**
+					 * TODO: find a way to detect something like this:
+					 *       $c = "OC_API";
+					 *       $n = new $i;
+					 */
+				}
+			}
+		}
+		if ($node instanceof Node\Stmt\UseUse) {
+			$this->checkBlackList($node->name->toString(), CodeChecker::CLASS_USE_NOT_ALLOWED, $node);
+			if ($node->alias) {
+				$this->addUseNameToBlackList($node->name->toString(), $node->alias);
+			} else {
+				$this->addUseNameToBlackList($node->name->toString(), $node->name->getLast());
+			}
+		}
+	}
+
+	/**
+	 * Check whether an alias was introduced for a namespace of a blacklisted class
+	 *
+	 * Example:
+	 * - Blacklist entry:      OCP\AppFramework\IApi
+	 * - Name:                 OCP\AppFramework
+	 * - Alias:                OAF
+	 * =>  new blacklist entry:  OAF\IApi
+	 *
+	 * @param string $name
+	 * @param string $alias
+	 */
+	private function addUseNameToBlackList($name, $alias) {
+		$name = strtolower($name);
+		$alias = strtolower($alias);
+
+		foreach ($this->blackListedClassNames as $blackListedAlias => $blackListedClassName) {
+			if (strpos($blackListedClassName, $name . '\\') === 0) {
+				$aliasedClassName = str_replace($name, $alias, $blackListedClassName);
+				$this->blackListedClassNames[$aliasedClassName] = $blackListedClassName;
+			}
+		}
+
+		foreach ($this->blackListedConstants as $blackListedAlias => $blackListedConstant) {
+			if (strpos($blackListedConstant, $name . '\\') === 0 || strpos($blackListedConstant, $name . '::') === 0) {
+				$aliasedConstantName = str_replace($name, $alias, $blackListedConstant);
+				$this->blackListedConstants[$aliasedConstantName] = $blackListedConstant;
+			}
+		}
+
+		foreach ($this->blackListedFunctions as $blackListedAlias => $blackListedFunction) {
+			if (strpos($blackListedFunction, $name . '\\') === 0 || strpos($blackListedFunction, $name . '::') === 0) {
+				$aliasedFunctionName = str_replace($name, $alias, $blackListedFunction);
+				$this->blackListedFunctions[$aliasedFunctionName] = $blackListedFunction;
+			}
+		}
+
+		foreach ($this->blackListedMethods as $blackListedAlias => $blackListedMethod) {
+			if (strpos($blackListedMethod, $name . '\\') === 0 || strpos($blackListedMethod, $name . '::') === 0) {
+				$aliasedMethodName = str_replace($name, $alias, $blackListedMethod);
+				$this->blackListedMethods[$aliasedMethodName] = $blackListedMethod;
+			}
+		}
+	}
+
+	private function checkBlackList($name, $errorCode, Node $node) {
+		$lowerName = strtolower($name);
+
+		if (isset($this->blackListedClassNames[$lowerName])) {
+			$this->errors[]= [
+				'disallowedToken' => $name,
+				'errorCode' => $errorCode,
+				'line' => $node->getLine(),
+				'reason' => $this->buildReason($this->blackListedClassNames[$lowerName], $errorCode)
+			];
+		}
+	}
+
+	private function checkBlackListConstant($class, $constantName, Node $node) {
+		$name = $class . '::' . $constantName;
+		$lowerName = strtolower($name);
+
+		if (isset($this->blackListedConstants[$lowerName])) {
+			$this->errors[]= [
+				'disallowedToken' => $name,
+				'errorCode' => CodeChecker::CLASS_CONST_FETCH_NOT_ALLOWED,
+				'line' => $node->getLine(),
+				'reason' => $this->buildReason($this->blackListedConstants[$lowerName], CodeChecker::CLASS_CONST_FETCH_NOT_ALLOWED)
+			];
+		}
+	}
+
+	private function checkBlackListFunction($class, $functionName, Node $node) {
+		$name = $class . '::' . $functionName;
+		$lowerName = strtolower($name);
+
+		if (isset($this->blackListedFunctions[$lowerName])) {
+			$this->errors[]= [
+				'disallowedToken' => $name,
+				'errorCode' => CodeChecker::STATIC_CALL_NOT_ALLOWED,
+				'line' => $node->getLine(),
+				'reason' => $this->buildReason($this->blackListedFunctions[$lowerName], CodeChecker::STATIC_CALL_NOT_ALLOWED)
+			];
+		}
+	}
+
+	private function checkBlackListMethod($class, $functionName, Node $node) {
+		$name = $class . '::' . $functionName;
+		$lowerName = strtolower($name);
+
+		if (isset($this->blackListedMethods[$lowerName])) {
+			$this->errors[]= [
+				'disallowedToken' => $name,
+				'errorCode' => CodeChecker::CLASS_METHOD_CALL_NOT_ALLOWED,
+				'line' => $node->getLine(),
+				'reason' => $this->buildReason($this->blackListedMethods[$lowerName], CodeChecker::CLASS_METHOD_CALL_NOT_ALLOWED)
+			];
+		}
+	}
+
+	private function buildReason($name, $errorCode) {
+		if (isset($this->errorMessages[$errorCode])) {
+			$desc = $this->list->getDescription($errorCode, $name);
+			return sprintf($this->errorMessages[$errorCode], $desc);
+		}
+
+		return "$name usage not allowed - error: $errorCode";
+	}
+}
diff --git a/lib/private/app/codechecker/privatecheck.php b/lib/private/app/codechecker/privatecheck.php
new file mode 100644
index 00000000000..d6f4eb06981
--- /dev/null
+++ b/lib/private/app/codechecker/privatecheck.php
@@ -0,0 +1,86 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\App\CodeChecker;
+
+class PrivateCheck extends AbstractCheck implements ICheck {
+	/**
+	 * @return string
+	 */
+	protected function getLocalDescription() {
+		return 'private';
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getLocalClasses() {
+		return [
+			// classes replaced by the public api
+			'OC_API' => '6.0.0',
+			'OC_App' => '6.0.0',
+			'OC_AppConfig' => '6.0.0',
+			'OC_Avatar' => '6.0.0',
+			'OC_BackgroundJob' => '6.0.0',
+			'OC_Config' => '6.0.0',
+			'OC_DB' => '6.0.0',
+			'OC_Files' => '6.0.0',
+			'OC_Helper' => '6.0.0',
+			'OC_Hook' => '6.0.0',
+			'OC_Image' => '6.0.0',
+			'OC_JSON' => '6.0.0',
+			'OC_L10N' => '6.0.0',
+			'OC_Log' => '6.0.0',
+			'OC_Mail' => '6.0.0',
+			'OC_Preferences' => '6.0.0',
+			'OC_Search_Provider' => '6.0.0',
+			'OC_Search_Result' => '6.0.0',
+			'OC_Request' => '6.0.0',
+			'OC_Response' => '6.0.0',
+			'OC_Template' => '6.0.0',
+			'OC_User' => '6.0.0',
+			'OC_Util' => '6.0.0',
+		];
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getLocalConstants() {
+		return [];
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getLocalFunctions() {
+		return [];
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getLocalMethods() {
+		return [];
+	}
+}
diff --git a/lib/private/app/codechecker/strongcomparisoncheck.php b/lib/private/app/codechecker/strongcomparisoncheck.php
new file mode 100644
index 00000000000..7de0fe3e5c3
--- /dev/null
+++ b/lib/private/app/codechecker/strongcomparisoncheck.php
@@ -0,0 +1,80 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\App\CodeChecker;
+
+class StrongComparisonCheck implements ICheck {
+	/** @var ICheck */
+	protected $check;
+
+	/**
+	 * @param ICheck $check
+	 */
+	public function __construct(ICheck $check) {
+		$this->check = $check;
+	}
+
+	/**
+	 * @param int $errorCode
+	 * @param string $errorObject
+	 * @return string
+	 */
+	public function getDescription($errorCode, $errorObject) {
+		return $this->check->getDescription($errorCode, $errorObject);
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getClasses() {
+		return $this->check->getClasses();
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getConstants() {
+		return $this->check->getConstants();
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getFunctions() {
+		return $this->check->getFunctions();
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getMethods() {
+		return $this->check->getMethods();
+	}
+
+	/**
+	 * @return bool
+	 */
+	public function checkStrongComparisons() {
+		return true;
+	}
+}
diff --git a/lib/private/app/codecheckvisitor.php b/lib/private/app/codecheckvisitor.php
deleted file mode 100644
index e983bd8630b..00000000000
--- a/lib/private/app/codecheckvisitor.php
+++ /dev/null
@@ -1,133 +0,0 @@
-<?php
-/**
- * @author Morris Jobke <hey@morrisjobke.de>
- * @author Thomas Müller <thomas.mueller@tmit.eu>
- *
- * @copyright Copyright (c) 2015, ownCloud, Inc.
- * @license AGPL-3.0
- *
- * This code is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License, version 3,
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License, version 3,
- * along with this program.  If not, see <http://www.gnu.org/licenses/>
- *
- */
-
-namespace OC\App;
-
-use PhpParser\Node;
-use PhpParser\Node\Name;
-use PhpParser\NodeVisitorAbstract;
-
-class CodeCheckVisitor extends NodeVisitorAbstract {
-
-	public function __construct($blackListedClassNames) {
-		$this->blackListedClassNames = array_map('strtolower', $blackListedClassNames);
-	}
-
-	public $errors = [];
-
-	public function enterNode(Node $node) {
-		if ($node instanceof Node\Expr\BinaryOp\Equal) {
-			$this->errors[]= [
-				'disallowedToken' => '==',
-				'errorCode' => CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED,
-				'line' => $node->getLine(),
-				'reason' => $this->buildReason('==', CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED)
-			];
-		}
-		if ($node instanceof Node\Expr\BinaryOp\NotEqual) {
-			$this->errors[]= [
-				'disallowedToken' => '!=',
-				'errorCode' => CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED,
-				'line' => $node->getLine(),
-				'reason' => $this->buildReason('!=', CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED)
-			];
-		}
-		if ($node instanceof Node\Stmt\Class_) {
-			if (!is_null($node->extends)) {
-				$this->checkBlackList($node->extends->toString(), CodeChecker::CLASS_EXTENDS_NOT_ALLOWED, $node);
-			}
-			foreach ($node->implements as $implements) {
-				$this->checkBlackList($implements->toString(), CodeChecker::CLASS_IMPLEMENTS_NOT_ALLOWED, $node);
-			}
-		}
-		if ($node instanceof Node\Expr\StaticCall) {
-			if (!is_null($node->class)) {
-				if ($node->class instanceof Name) {
-					$this->checkBlackList($node->class->toString(), CodeChecker::STATIC_CALL_NOT_ALLOWED, $node);
-				}
-				if ($node->class instanceof Node\Expr\Variable) {
-					/**
-					 * TODO: find a way to detect something like this:
-					 *       $c = "OC_API";
-					 *       $n = $i::call();
-					 */
-				}
-			}
-		}
-		if ($node instanceof Node\Expr\ClassConstFetch) {
-			if (!is_null($node->class)) {
-				if ($node->class instanceof Name) {
-					$this->checkBlackList($node->class->toString(), CodeChecker::CLASS_CONST_FETCH_NOT_ALLOWED, $node);
-				}
-				if ($node->class instanceof Node\Expr\Variable) {
-					/**
-					 * TODO: find a way to detect something like this:
-					 *       $c = "OC_API";
-					 *       $n = $i::ADMIN_AUTH;
-					 */
-				}
-			}
-		}
-		if ($node instanceof Node\Expr\New_) {
-			if (!is_null($node->class)) {
-				if ($node->class instanceof Name) {
-					$this->checkBlackList($node->class->toString(), CodeChecker::CLASS_NEW_FETCH_NOT_ALLOWED, $node);
-				}
-				if ($node->class instanceof Node\Expr\Variable) {
-					/**
-					 * TODO: find a way to detect something like this:
-					 *       $c = "OC_API";
-					 *       $n = new $i;
-					 */
-				}
-			}
-		}
-	}
-
-	private function checkBlackList($name, $errorCode, Node $node) {
-		if (in_array(strtolower($name), $this->blackListedClassNames)) {
-			$this->errors[]= [
-				'disallowedToken' => $name,
-				'errorCode' => $errorCode,
-				'line' => $node->getLine(),
-				'reason' => $this->buildReason($name, $errorCode)
-			];
-		}
-	}
-
-	private function buildReason($name, $errorCode) {
-		static $errorMessages= [
-			CodeChecker::CLASS_EXTENDS_NOT_ALLOWED => "used as base class",
-			CodeChecker::CLASS_IMPLEMENTS_NOT_ALLOWED => "used as interface",
-			CodeChecker::STATIC_CALL_NOT_ALLOWED => "static method call on private class",
-			CodeChecker::CLASS_CONST_FETCH_NOT_ALLOWED => "used to fetch a const from",
-			CodeChecker::CLASS_NEW_FETCH_NOT_ALLOWED => "is instanciated",
-			CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED => "is discouraged"
-		];
-
-		if (isset($errorMessages[$errorCode])) {
-			return $errorMessages[$errorCode];
-		}
-
-		return "$name usage not allowed - error: $errorCode";
-	}
-}