ID: 49037
Updated by: [email protected]
Reported By: alex dot emsenhuber at bluewin dot ch
-Status: Open
+Status: Assigned
Bug Type: Scripting Engine problem
Operating System: Mac OS X 10.5.7
PHP Version: 6SVN-2009-07-23 (SVN)
-Assigned To:
+Assigned To: dmitry
Previous Comments:
------------------------------------------------------------------------
[2009-07-23 18:27:02] alex dot emsenhuber at bluewin dot ch
Description:
------------
When using @list( $b ) = $a; on PHP 6, it seems that a new opcode is
inserted that frees a temp variable set from $a (see the "Actual result"
section below) and thus segfaults when using $a later. When I set
breakpoints on all lines that contains "SWITCH_FREE" in Zend_execute.c,
it's the one at line 1170 in function zend_do_free() that is called.
Reproduce code:
---------------
<?php
$a = array( "c" );
@list( $b ) = $a;
var_dump( $a );
I also used vld to get the opcodes produced by the laguage parser.
Expected result:
----------------
array(1) {
[0]=>
string(1) "c"
}
Analyse with vld:
$ PHP_5_3/sapi/cli/php -dvld.active=1 ~/test.php
Branch analysis from position: 0
Return found
filename: /Users/alexandre/test.php
function name: (null)
number of ops: 11
compiled vars: !0 = $a
line # op fetch ext return
operands
-------------------------------------------------------------------------------
2 0 INIT_ARRAY ~0
'c'
1 ASSIGN
!0, ~0
3 2 BEGIN_SILENCE ~2
3 FETCH_R local $4
'a'
4 FETCH_DIM_R $5
$4, 0
5 FETCH_W local $3
'b'
6 ASSIGN
$3, $5
7 END_SILENCE
~2
4 8 SEND_VAR
!0
9 DO_FCALL 1
'var_dump'
5 10 RETURN 1
Actual result:
--------------
Segmentation fault.
Analyse with vld:
$ PHP_6/sapi/cli/php -dvld.active=1 ~/test.php
Branch analysis from position: 0
Return found
filename: /Users/alexandre/test.php
function name: (null)
number of ops: 12
compiled vars: !0 = $a
line # op fetch ext return
operands
-------------------------------------------------------------------------------
2 0 INIT_ARRAY ~0 c
1 ASSIGN
!0, ~0
3 2 BEGIN_SILENCE ~2
3 FETCH_R local $4 a
4 FETCH_DIM_TMP_VAR $5
$4, 0
5 FETCH_W local $3 b
6 ASSIGN
$3, $5
7 END_SILENCE
~2
8 SWITCH_FREE
$4
4 9 SEND_VAR
!0
10 DO_FCALL 1
var_dump
5 11 RETURN 1
You can see the new opcode "SWITCH_FREE" at position 8.
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=49037&edit=1
