xdebug_start_trace

gistfile1.txt

php.ini (php 5.6)
; add by zs
zend_extension=xdebug.so
xdebug.trace_output_dir = /tmp/traces
;代码跟踪日志文件格式 
xdebug.trace_output_name = trace.%c.%p
;;trace中显示函数的参数值，这个很有用，待会细说
xdebug.collect_params = 4
xdebug.collect_includes = On
xdebug.collect_return = On
xdebug.show_mem_delta = On

// code here
<?php
xdebug_start_trace();
function say($a)
{
    $a++;
    echo $a;
    return;
}

$a = 1;
say($a);
xdebug_stop_trace();

// trace log here
TRACE START [2016-05-22 09:34:50]
    0.0002     239680      +88     -> say($a = 1) /home/wwwroot/default/x.php:11
    0.0002     239728              >=> NULL
    0.0002     239728      +48     -> xdebug_stop_trace() /home/wwwroot/default/x.php:12
    0.0002     239784
TRACE END   [2016-05-22 09:34:50]
(Time here is UTC)