<?php
class a {
 public function a1 () {
 try {
  throw new Exception('123');
 } catch (Exception $e) {
  throw $e;
 }
 }
}

class b {
 public function b1 () {
 try {
  $a = new a();
  $a->a1();
 } catch (Exception $e) {
  throw $e;
  //throw new Exception($e->getMessage());
 }
 }
}

class c {
 public function c1 () {
 try {
  $a = new b();
  $a->b1();
 } catch (Exception $e) {
  throw $e;
 }
 }
}

try {
 $c = new c();
 $c->c1();
} catch (Exception $e) {
 echo $e->getTraceAsString();
}
echo 789;

?>