ClassFinder.php

<?php

namespace Drupal\Component\ClassFinder;

use Doctrine\Common\Reflection\ClassFinderInterface;

/**
 * A Utility class that uses active autoloaders to find a file for a class.
 */
class ClassFinder implements ClassFinderInterface {
    
    /**
     * {@inheritdoc}
     */
    public function findFile($class) {
        $loaders = spl_autoload_functions();
        foreach ($loaders as $loader) {
            if (is_array($loader) && isset($loader[0]) && is_object($loader[0]) && method_exists($loader[0], 'findFile')) {
                $file = call_user_func_array([
                    $loader[0],
                    'findFile',
                ], [
                    $class,
                ]);
                // Different implementations return different empty values. For example,
                // \Composer\Autoload\ClassLoader::findFile() returns FALSE whilst
                // \Doctrine\Common\Reflection\ClassFinderInterface::findFile()
                // documents that a NULL should be returned.
                if (!empty($file)) {
                    return $file;
                }
            }
        }
        return NULL;
    }

}