<?php
Class Foo
{
    const A = 1;
    const B = self::A;
}

$rc = new ReflectionClass('Foo');
print_r($rc->getConstants());

Class Foo2
{
        const A = 1;
        const B = self::A;
}

$rc = new ReflectionClass('Foo2');
print_r($rc->getConstant('B'));
?>