php安装vld扩展查看编译opcode

wget http://pecl.php.net/get/vld-0.14.0.tgz
tar -zxvf vld-0.14.0.tgz
/usr/local/php/bin/phpize
./configure --with-php-config=/usr/local/php/bin/php-config --enable-vld
make && make install
vim /usr/local/php/etc/php.ini ，在文件最后面加入 extension=vld.so
service php-fpm restart //重启php-fpm

例子
vim array.php
<?php
$tmp = array('a'=>'a','b'=>'b','c'=>'c');
$a = $tmp['a'];
$b = $tmp[b];
$c = $tmp["c"];
然后执行
php -dvld.active=1 ./array.php //如果加入 -dvld.execute=0(默认是1),则文件只输出opcode而不执行

返回结果如下
Finding entry points
Branch analysis from position: 0
Jump found. (Code = 62) Position 1 = -2
filename: /data/www/study/array.php
function name: (null)
number of ops: 9
compiled vars: !0 = $tmp, !1 = $a, !2 = $b, !3 = $c
line #* E I O op fetch ext return operands

2 0 E > ASSIGN !0,
3 1 FETCH_DIM_R $5 !0, 'a'
2 ASSIGN !1, $5
4 3 FETCH_CONSTANT ~7 'b'
4 FETCH_DIM_R $8 !0, ~7
5 ASSIGN !2, $8
5 6 FETCH_DIM_R $10 !0, 'c'
7 ASSIGN !3, $10
6 8 > RETURN 1

branch: # 0; line: 2- 6; sop: 0; eop: 8; out1: -2
path #1: 0,
PHP Notice: Use of undefined constant b - assumed 'b' in /data/www/study/array.php on line 4