How find source code for eval'd function in PHP?

<?php

function myfunction() {
	echo "Test";
}

eval('
function myevalfunction() {
	echo "Test";
}
');

$a = new ReflectionFunction('myfunction');
echo $a;

$b = new ReflectionFunction('myevalfunction');
echo $b;

?>

Function [ <user> <visibility error> function myfunction ] {
  @@ test.php 3 - 5
}
Function [ <user> <visibility error> function myevalfunction ] {
  @@ test.php(11) : eval()'d code 2 - 4
}

function myeval($code) {
     my_eval_tracking($code, ...);  # use traceback to get more info if necessary
     # (...)
     return eval($code);
}

if ( $cond ){
   function foo(){

   }
}