implement php code checker to detect usage of not allowed private APIs - including console command to check local code to be used by developers

2 files changed, 226 insertions, 0 deletions

diff --git a/lib/private/app/codechecker.php b/lib/private/app/codechecker.php
new file mode 100644
index 00000000000..28816a8fdc5
--- /dev/null
+++ b/lib/private/app/codechecker.php
@@ -0,0 +1,115 @@
+<?php
+/**
+ * Copyright (c) 2015 Thomas Müller <deepdiver@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OC\App;
+
+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;
+use RecursiveIteratorIterator;
+use RegexIterator;
+use SplFileInfo;
+
+class CodeChecker extends BasicEmitter {
+
+	const CLASS_EXTENDS_NOT_ALLOWED = 1000;
+	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;
+
+	public function __construct() {
+		$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_Request',
+			'OC_Response',
+			'OC_Template',
+			'OC_User',
+			'OC_Util',
+		];
+	}
+
+	/**
+	 * @param string $appId
+	 * @return array
+	 */
+	public function analyse($appId) {
+		$appPath = \OC_App::getAppPath($appId);
+		if ($appPath === false) {
+			throw new \RuntimeException("No app with given id <$appId> known.");
+		}
+
+		$errors = [];
+
+		$excludes = array_map(function($item) use ($appPath) {
+			return $appPath . '/' . $item;
+		}, ['vendor', '3rdparty', '.git', 'l10n']);
+
+		$iterator = new RecursiveDirectoryIterator($appPath, RecursiveDirectoryIterator::SKIP_DOTS);
+		$iterator = new RecursiveCallbackFilterIterator($iterator, function($item) use ($appPath, $excludes){
+			/** @var SplFileInfo $item */
+			foreach($excludes as $exclude) {
+				if (substr($item->getPath(), 0, strlen($exclude)) === $exclude) {
+					return false;
+				}
+			}
+			return true;
+		});
+		$iterator = new RecursiveIteratorIterator($iterator);
+		$iterator = new RegexIterator($iterator, '/^.+\.php$/i');
+
+		foreach ($iterator as $file) {
+			/** @var SplFileInfo $file */
+			$this->emit('CodeChecker', 'analyseFileBegin', [$file->getPathname()]);
+			$errors = array_merge($this->analyseFile($file), $errors);
+			$this->emit('CodeChecker', 'analyseFileFinished', [$errors]);
+		}
+
+		return $errors;
+	}
+
+	/**
+	 * @param string $file
+	 * @return array
+	 */
+	public function analyseFile($file) {
+		$code = file_get_contents($file);
+		$statements = $this->parser->parse($code);
+
+		$visitor = new CodeCheckVisitor($this->blackListedClassNames);
+		$traverser = new NodeTraverser;
+		$traverser->addVisitor($visitor);
+
+		$traverser->traverse($statements);
+
+		return $visitor->errors;
+	}
+}
diff --git a/lib/private/app/codecheckervisitor.php b/lib/private/app/codecheckervisitor.php
new file mode 100644
index 00000000000..939c905bcf6
--- /dev/null
+++ b/lib/private/app/codecheckervisitor.php
@@ -0,0 +1,111 @@
+<?php
+/**
+ * Copyright (c) 2015 Thomas Müller <deepdiver@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OC\App;
+
+use OC\Hooks\BasicEmitter;
+use PhpParser\Lexer;
+use PhpParser\Node;
+use PhpParser\Node\Name;
+use PhpParser\NodeTraverser;
+use PhpParser\NodeVisitorAbstract;
+use PhpParser\Parser;
+use RecursiveCallbackFilterIterator;
+use RecursiveDirectoryIterator;
+use RecursiveIteratorIterator;
+use RegexIterator;
+use SplFileInfo;
+
+class CodeCheckVisitor extends NodeVisitorAbstract {
+
+	public function __construct($blackListedClassNames) {
+		$this->blackListedClassNames = array_map('strtolower', $blackListedClassNames);
+	}
+
+	public $errors = [];
+
+	public function enterNode(Node $node) {
+		if ($node instanceof Node\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 $errorMessages= [
+			CodeChecker::CLASS_EXTENDS_NOT_ALLOWED => "used as base class",
+			CodeChecker::CLASS_IMPLEMENTS_NOT_ALLOWED => "used as interface",
+			CodeChecker::STATIC_CALL_NOT_ALLOWED => "static method call on private class",
+			CodeChecker::CLASS_CONST_FETCH_NOT_ALLOWED => "used to fetch a const from",
+			CodeChecker::CLASS_NEW_FETCH_NOT_ALLOWED => "is instanciated",
+		];
+
+		if (isset($errorMessages[$errorCode])) {
+			return $errorMessages[$errorCode];
+		}
+
+		return "$name usage not allowed - error: $errorCode";
+	}
+}