Checking PHP code for compatibility issues

One project I occassionally hack on is Xerte Toolkits.

Yesterday on the mailing list it came up that someone was trying to use XOT with PHP4.

After getting over some initial shock that people still use PHP4 (it was end-of-lifed in August 2008) I wondered how easy it would be to check the status of a code base to find how incompatible with PHP4 it now is.

My initial thought was to find a list of functions which had been added with PHP5 and then just grep the code for them, but it turns out there is a much nicer approach – PHP_CompatInfo

Installation was fairly straight forward – like :

pear channel-discover bartlett.laurent-laville.org
pear install bartlett/PHP_CompatInfo

Annoyingly the documentation seemed well hidden – but once I found it (http://php5.laurent-laville.org/compatinfo/manual/2.3/en/index.html#_documentation) it was pretty easy to use, and the ‘phpci’ command did all I needed –

Examples :

1. List global variables in use :

$ phpci print --reference PHP5 --report global -R . 
436 / 436 [+++++++++++++++++++++++++++++++++++++++++++++++++++++++++>] 100.00%
BASE: /home/david/src/XOT/trunk

-------------------------------------------------------------------------------
PHP COMPAT INFO GLOBAL SUMMARY
-------------------------------------------------------------------------------
  GLOBAL                                                  VERSION         COUNT
-------------------------------------------------------------------------------
                                        $_GET             4.1.0               1
  data                                  $_GET             4.1.0               2
  debug                                 $_GET             4.1.0               2
  export                                $_GET             4.1.0               2
  file                                  $_GET             4.1.0               1
  firstname                             $_GET             4.1.0               1
....

2. Find all PHP5 functions in use :

$ phpci print  --report function -R . | grep 5.
436 / 436 [+++++++++++++++++++++++++++++++++++++++++++++++++++++++++>] 100.00%
  spl_autoload_register                 SPL               5.1.2               1
  simplexml_load_file                   SimpleXML         5.0.0               1
  iconv_set_encoding                    iconv             4.0.5               1
  iconv_strlen                          iconv             5.0.0              10
  iconv_strpos                          iconv             5.0.0              38
  iconv_strrpos                         iconv             5.0.0               3
  iconv_substr                          iconv             5.0.0              33
  dirname                               standard          4.0.0              53
  fclose                                standard          4.0.0              51
  file_put_contents                     standard          5.0.0               6
  fopen                                 standard          4.0.0              55
  fread                                 standard          4.0.0              57
  fwrite                                standard          4.0.0              50
  htmlentities                          standard          5.2.3               1
  md5                                   standard          4.0.0               1
  scandir                               standard          5.0.0               1
  str_split                             standard          5.0.0               3
REQUIRED PHP 5.2.3 (MIN) 
Time: 0 seconds, Memory: 28.25Mb

and finally,

3. Class usage :

$ phpci print  --report class -R . | grep 5.
436 / 436 [+++++++++++++++++++++++++++++++++++++++++++++++++++++++++>] 100.00%
  Exception                             SPL               5.1.0               1
  InvalidArgumentException              SPL               5.1.0               2
REQUIRED PHP 5.1.0 (MIN)

4. All class usage :

i.e. without me grep’ping the results.

$ phpci print  --report class -R . 
436 / 436 [+++++++++++++++++++++++++++++++++++++++++++++++++++++++++>] 100.00%
BASE: /home/david/src/XOT/trunk

-------------------------------------------------------------------------------
PHP COMPAT INFO CLASS SUMMARY
-------------------------------------------------------------------------------
  CLASS                                 EXTENSION         VERSION         COUNT
-------------------------------------------------------------------------------
  Exception                             SPL               5.1.0               1
  InvalidArgumentException              SPL               5.1.0               2
  PHP_CompatInfo                                          4.0.0               1
  Snoopy                                                  4.0.0               2
  StdClass                                                4.0.0               2
  Xerte_Authentication_Abstract                           4.0.0               6
  Xerte_Authentication_Factory                            4.0.0               4
  Xerte_Authentication_Guest                              4.0.0               1
  Xerte_Authentication_Ldap                               4.0.0               1
  Xerte_Authentication_Moodle                             4.0.0               1
  Xerte_Authentication_Static                             4.0.0               1
  Xerte_Authetication_Db                                  4.0.0               1
  Zend_Exception                                          4.0.0               2
  Zend_Locale                                             4.0.0               7
  Zend_Locale_Data                                        4.0.0              19
  Zend_Locale_Data_Translation                            4.0.0               6
  Zend_Locale_Exception                                   4.0.0              28
  Zend_Locale_Format                                      4.0.0               3
  Zend_Locale_Math                                        4.0.0              14
  Zend_Locale_Math_Exception                              4.0.0               9
  Zend_Locale_Math_PhpMath                                4.0.0              11
  archive                                                 4.0.0               3
  bzip_file                                               4.0.0               1
  dUnzip2                                                 4.0.0               3
  gzip_file                                               4.0.0               1
  tar_file                                                4.0.0               3
  toolkits_session_handler                                4.0.0               1
  zip_file                                                4.0.0               2
-------------------------------------------------------------------------------
A TOTAL OF 28 CLASS(S) WERE FOUND
REQUIRED PHP 5.1.0 (MIN) 
-------------------------------------------------------------------------------
Time: 0 seconds, Memory: 27.50Mb
-------------------------------------------------------------------------------

Which answers my question(s) and so on.

Silly SoapClient

Sam made some changes to a SOAP service one customer has – and suddenly our automated tests kept failing. “WTF?” we thought.

We persistently got the same error (e.g. Fatal error: SOAP-ERROR: Encoding: object hasn’t ‘SortResults’ property in ….) yet the generated WSDL file (when viewed through a web browser etc) no longer has SortResults in it.

We checked :

  • Proxy settings,
  • Apache configuration (and restarted Apache)
  • svn reverted files
  • DNS and more.

Then it turned out the SoapClient PHP object caches the WSDL file by default in e.g. /tmp/wsdl-blahblahblah. (Where blahblahblah looks very much like an md5). And it doesn’t make much of an effort to check it’s validity. Obviously the documentation does state this, but it does seem like the wrong default behaviour to me.

Solution: Add something to the automated tests to delete /tmp/wsdl-*. OR pass into the SoapClient constructor an array of options like :

$client = new SoapClient('http://somewhere/blah.php?wsdl", array(cache_wsdl => WSDL_CACHE_NONE)

Time wasted: Too much.