Are there any tools that can list the names of classes used by a PHP file?

For example, if I ran it on this file:

<?
class Test {
  public function __construct(Obj1 $x) {
    $y = new Obj2();
    $str = "Obj3";
    $z = new $str();
  }
}
?>

it would report "Obj1" and "Obj2". If it were really smart it might report "Obj3" as well, but that's not essential.

I'm trying to package up some code, and I want some help making sure that I didn't miss any dependencies.

There's something called PHP_Depend, which can graph the number of dependencies, but can't report what they are.