How to get all touched files/classes during the response generation

I’ve used autoload but it’s not giving all the files/classes that’s been used during request

spl_autoload_register(function ($class) {
    $logFile = __DIR__ . '/autoload_log.txt';
    $message = $class . "n";
    file_put_contents($logFile, $message, FILE_APPEND);
}, true, true);

Is there any other way to trace all classes that’s been involved during the page generation?