CodeCoverage: added support for phpdbg strategy as alternative to Xdebug

src/CodeCoverage/Collector.php

@@ -13,27 +13,78 @@
  */
 class Collector
 {
+	const
+		STRATEGY_AUTO = 'Auto',
+		STRATEGY_XDEBUG = 'Xdebug',
+		STRATEGY_PHPDBG = 'PhpDbg';
+
 	/** @var resource */
 	private static $file;
 
 
 	/**
 	 * Starts gathering the information for code coverage.
 	 * @param  string
+	 * @param  string self::STRATEGY_*
 	 * @return void
 	 */
-	public static function start($file)
+	public static function start($file, $strategy = self::STRATEGY_AUTO)
 	{
-		if (!extension_loaded('xdebug')) {
-			throw new \Exception('Code coverage functionality requires Xdebug extension.');
-		} elseif (self::$file) {
+		if (self::$file) {
 			throw new \LogicException('Code coverage collector has been already started.');
 		}
 
+		$method = "start$strategy";
+		if (!method_exists(__CLASS__, $method)) {
+			throw new \LogicException("Unknown strategy '$strategy'");
+		}
+
 		self::$file = fopen($file, 'a+');
+		self::$method();
+	}
+
+
+	/**
+	 * @return void
+	 */
+	private static function startAuto()
+	{
+		if (defined('PHPDBG_VERSION')) {
+			self::startPhpDbg();
+		} else {
+			self::startXdebug();
+		}
+	}
+
+
+	/**
+	 * @return void
+	 */
+	private static function startXdebug()
+	{
+		if (!extension_loaded('xdebug')) {
+			throw new \Exception('Code coverage functionality requires Xdebug extension.');
+		}
+
 		xdebug_start_code_coverage(XDEBUG_CC_UNUSED | XDEBUG_CC_DEAD_CODE);
 		register_shutdown_function(function () {
-			register_shutdown_function(array(__CLASS__, 'save'));
+			register_shutdown_function(array(__CLASS__, 'saveXdebug'));
+		});
+	}
+
+
+	/**
+	 * @return void
+	 */
+	private static function startPhpDbg()
+	{
+		if (!defined('PHPDBG_VERSION')) {
+			throw new \Exception('Code coverage functionality requires phpdbg SAPI.');
+		}
+
+		phpdbg_start_oplog();
+		register_shutdown_function(function () {
+			register_shutdown_function(array(__CLASS__, 'savePhpDbg'));
 		});
 	}
 
@@ -43,23 +94,63 @@ public static function start($file)
 	 * @return void
 	 * @internal
 	 */
-	public static function save()
+	public static function saveXdebug()
 	{
-		flock(self::$file, LOCK_EX);
-		fseek(self::$file, 0);
-		$coverage = @unserialize(stream_get_contents(self::$file)); // @ file may be empty
+		$positive = array();
+		$negative = array();
 
-		foreach (xdebug_get_code_coverage() as $filename => $lines) {
-			if (!file_exists($filename)) {
+		foreach (xdebug_get_code_coverage() as $file => $lines) {
+			if (!file_exists($file)) {
 				continue;
 			}
+
 			foreach ($lines as $num => $val) {
-				if (empty($coverage[$filename][$num]) || $val > 0) {
-					$coverage[$filename][$num] = $val; // -1 => untested; -2 => dead code
+				if ($val > 0) {
+					$positive[$file][$num] = $val;
+				} else {
+					$negative[$file][$num] = $val;
 				}
 			}
 		}
 
+		self::save($positive, $negative);
+	}
+
+
+	/**
+	 * Saves information about code coverage. Do not call directly.
+	 * @return void
+	 * @internal
+	 */
+	public static function savePhpDbg()
+	{
+		$positive = phpdbg_end_oplog();
+		$negative = phpdbg_get_executable();
+
+		foreach ($positive as $file => &$lines) {
+			$lines = array_fill_keys(array_keys($lines), 1);
+		}
+
+		foreach ($negative as $file => &$lines) {
+			$lines = array_fill_keys(array_keys($lines), -1);
+		}
+
+		self::save($positive, $negative);
+	}
+
+
+	/**
+	 * @param  array
+	 * @param  array
+	 * @return void
+	 */
+	private static function save(array $positive, array $negative)
+	{
+		flock(self::$file, LOCK_EX);
+		fseek(self::$file, 0);
+		$original = @unserialize(stream_get_contents(self::$file)) ?: array(); // @ file may be empty
+		$coverage = array_replace_recursive($negative, $original, $positive);
+
 		ftruncate(self::$file, 0);
 		fwrite(self::$file, serialize($coverage));
 		fclose(self::$file);

src/Runner/CliTester.php

@@ -230,9 +230,6 @@ private function createRunner()
 	/** @return string */
 	private function prepareCodeCoverage()
 	{
-		if (!$this->interpreter->hasXdebug()) {
-			throw new \Exception("Code coverage functionality requires Xdebug extension (used {$this->interpreter->getCommandLine()})");
-		}
 		file_put_contents($this->options['--coverage'], '');
 		$file = realpath($this->options['--coverage']);
 		putenv(Environment::COVERAGE . '=' . $file);