Symfony Debug Extension for PHP 5
=================================

This extension publishes several functions to help building powerful debugging tools.
It is compatible with PHP 5.3, 5.4, 5.5 and 5.6; with ZTS and non-ZTS modes.
It is not required thus not provided for PHP 7.

symfony_zval_info()
-------------------

- exposes zval_hash/refcounts, allowing e.g. efficient exploration of arbitrary structures in PHP,
- does work with references, preventing memory copying.

Its behavior is about the same as:

```php
<?php

function symfony_zval_info($key, $array, $options = 0)
{

// $options is currently not used, but could be in future version.

if (!array_key_exists($key, $array)) {
return null;
}

$info = array(
'type' => gettype($array[$key]),
'zval_hash' => /* hashed memory address of $array[$key] */,
'zval_refcount' => /* internal zval refcount of $array[$key] */,
'zval_isref' => /* is_ref status of $array[$key] */,
);

switch ($info['type']) {
case 'object':
$info += array(
'object_class' => get_class($array[$key]),
'object_refcount' => /* internal object refcount of $array[$key] */,
'object_hash' => spl_object_hash($array[$key]),
'object_handle' => /* internal object handle $array[$key] */,
);
break;

case 'resource':
$info += array(
'resource_handle' => (int) $array[$key],
'resource_type' => get_resource_type($array[$key]),
'resource_refcount' => /* internal resource refcount of $array[$key] */,
);
break;

case 'array':
$info += array(
'array_count' => count($array[$key]),
);
break;

case 'string':
$info += array(
'strlen' => strlen($array[$key]),
);
break;
}

return $info;
}
```

symfony_debug_backtrace()
-------------------------

This function works like debug_backtrace(), except that it can fetch the full backtrace in case of fatal errors:

```php
function foo() { fatal(); }
function bar() { foo(); }

function sd() { var_dump(symfony_debug_backtrace()); }

register_shutdown_function('sd');

bar();

/* Will output
Fatal error: Call to undefined function fatal() in foo.php on line 42
array(3) {
[0]=>
array(2) {
["function"]=>
string(2) "sd"
["args"]=>
array(0) {
}
}
[1]=>
array(4) {
["file"]=>
string(7) "foo.php"
["line"]=>
int(1)
["function"]=>
string(3) "foo"
["args"]=>
array(0) {
}
}
[2]=>
array(4) {
["file"]=>
string(102) "foo.php"
["line"]=>
int(2)
["function"]=>
string(3) "bar"
["args"]=>
array(0) {
}
}
}
*/
```

Usage
-----

To enable the extension from source, run:

```
phpize
./configure
make
sudo make install
```