Xdebug 2.3: Munging errors
This is the third article in a series about new features in Xdebug 2.3, which was first released on February 22nd.
One of the first features I added to Xdebug was the interception of error messages, so that it was possible to shows stack traces when an error occurred. Xdebug 2.3 has a few additional settings to control the behaviour of interception.
First, we have the new xdebug.halt_level. This setting allows you to tell Xdebug to convert certain warnings into fatal errors. Due to the way how PHP works, you can currently only do this for E_WARNING
, E_NOTICE
, E_USER_WARNING
, and E_USER_NOTICE
.
Setting xdebug.halt_level
to E_NOTICE | E_USER_NOTICE
will make the following script not show Hi!
:
<?php ini_set('xdebug.halt_level', E_USER_NOTICE | E_NOTICE); trigger_error("Testing"); echo "Hi!\n"; ?>
Instead, it will show the call stack, and then abort the script:
Notice: Testing in - on line 3 Call Stack: 0.0082 258480 1. {main}() -:0 0.0085 259400 2. trigger_error() -:3
This feature was requested by Rob Allen, who also wrote about it.
The second related improvement is the addition of the xdebug.force_display_errors and xdebug.force_error_reporting settings. These php.ini only settings can be used to override PHP's display_errors and error_reporting settings. This is typically useful in a legacy code base where developers tried to be clever about not showing warnings, or for example turning of notices that now hamper developer - or upgrade efforts.
Take the following script:
<?php ini_set("display_errors", 0); trigger_error("two"); ?>
When you run this with just php thescript.php
, the output will be nothing (because you are hiding errors). Running the example script with php -d
xdebug.force_display_errors=1 thescript.php
, the output becomes:
Notice: two in /tmp/thescript.php on line 3 Call Stack: 0.0002 261072 1. {main}() /tmp/thescript.php:0 0.0002 261944 2. trigger_error() /tmp/thescript.php:3
The related setting xdebug.force_error_reporting acts at a bit mask to force certain errors to be shown. Even with error_reporting
set to 0
, the following script run with php -d xdebug.force_error_reporting
/tmp/otherscript.php
will still show the errors:
<?php ini_set("error_reporting", E_ERROR | E_WARNING | E_USER_WARNING); trigger_error("two", E_USER_NOTICE); ?>
With as output:
Notice: two in /tmp/otherscript.php on line 3 Call Stack: 0.0002 261432 1. {main}() /tmp/otherscript.php:0 0.0003 262352 2. trigger_error() /tmp/otherscript.php:3
Other parts in this series:
Shortlink
This article has a short URL available: https://drck.me/errors23-bns