How do you automate the upgrading process from PHP 5.x to PHP 7 ? How do you know if your code is compatible with the next version of PHP ?

1. Is my code ready for PHP 7 ?
I told engineering
to upgrade all servers
to PHP 7. That's OK,
right ? I uh...
I guess...

2. Before we begin
Send a text to +32460200098
Powered by PHP 7
Copyright Michelangelo ;-)

3. Who am I ?
Wim Godden (@wimgtr)
Founder of Cu.be Solutions (http://cu.be)
Open Source developer since 1997
Developer of PHPCompatibility, OpenX, PHPConsistent, ...
Speaker at Open Source conferences

4. Why vs How
Why upgrade ?
Bad reasons :
It's cool to have the latest version
Annoy sysadmins
Oh cool, a new toy !
How to upgrade ?
The nightmare of compatibility
The joy of automation
No miracles here !

5. Show of hands
3 / 4
5.0
5.1
5.2
5.3
5.4
5.5
5.6
6.0
7.0

6. The numbers
W3Techs (http://w3techs.com/technologies/details/pl-php/all/all)
Dec 2015 Jan 2015 Nov 2013
PHP 4 : 1.3% 1.8% 2.7%
PHP 5 : 98.7% 98.2% 97.3%
5.0 : <0.1% < 0.1% 0.1%
5.1 : 0.9% 1.2% 2.0%
5.2 : 13.2% 19.2% 37.6%
5.3 : 35.9% 45.5% 52.0%
5.4 : 31.0% 26.9% 7.9%
5.5 : 14.5% 6.3% 0.5%
5.6 : 4.4% 0.5% < 0.1%
PHP 7 : < 0.1%

7. So...
Should you upgrade today ?

8. Upgrade : yes / no
Yes No
Using removed extensions x
Using removed functions x
Need extra performance / reduced memory x
Really need new feature x
Want to use recent framework x
No unit tests x
No package available (.rpm, .deb, ...) x

9. Postponing upgrades
End-Of-Life
In the past : we'll see
Now : minor release + 2 = out → EOL
5.6 = OUT → 5.4 = EOL
7.0 = OUT → 5.5 = EOL
Critical security patches : 1 year
No bugfixes
Framework support
Developer motivation

10. So you want to upgrade...

11. So you want to upgrade...
Option 1 : run your unit tests
Option 2 : visit each page (good luck !) + check error_log
Or : record visits, then replay log on test environment
Option 3 : automated static analysis

12. Unit tests on different PHP versions
Vagrant boxes
Integrate into your CI
Use Travis CI (http://travis-ci.org)

13. Why make it so hard ? A best-case scenario...
Development environment : 5.6
Production environment : 5.6
All is well, right ?
Today : PHP 7 arrives
How can you test compatibility ?
→ Set up your test environment today
→ Even for new projects

14. Migrating an entire infrastructure ?

15. Back in 2010...
PHP Architect @ Belgian Railways
8 years of legacy code
40+ different developers
40+ projects
Challenge :
migrate all projects from
PHP 5.1.x (on Solaris)
to
PHP 5.3.x (on Linux)

16. The idea
Automate it
How ? → Use the CI environment
Which tool ? → PHP_CodeSniffer

17. PHP_CodeSniffer
PEAR package (pear install PHP_CodeSniffer)
Composer (squizlabs/php_codesniffer)
Detect coding standard violations
Supports multiple standards
Static analysis tool
→ Runs without executing code
→ Splits code in tokens
Ex. : T_OPEN_CURLY_BRACKET
T_FALSE
T_SEMICOLON

18. PHP_CodeSniffer
Let's see what it looks like

19. PHPCompatibility
PHP_CodeSniffer standard
Only purpose : find compatibility issues
Detects :
Deprecated functions
Deprecated extensions
Deprecated php.ini settings and ini_set() calls
Prohibited function names, class names, …
…
Works for PHP 5.0 and above

20. PHPCompatibility – making it work
Via Composer : wimg/php-compatibility
From Github :
Download :
http://github.com/wimg/PHPCompatibility
Install in <pear_dir>/PHP/CodeSniffer/Standards
Run :
phpcs --standard=PHPCompatibility <path>

21. PHPCompatibility
Let's see what it looks like

22. Important notes
Large directories → can be slow !
Use --extensions=php,phtml
No point scanning .js files
Static analysis
Doesn't run code
Can not detect every single incompatibility
Provides filename and line number
You can check for specific versions :
--runtime-set testVersion 5.3
or
--runtime-set testVersion 5.3-5.5

23. The result
Zend Framework 1.7 app
PHP 5.2 : working fine
PHP 5.3 : fail !
function goto()

24. Some common apps – phpBB (latest)
FILE: /usr/src/phpBB3/adm/index.php
--------------------------------------------------------------------------------
FOUND 0 ERROR(S) AND 2 WARNING(S) AFFECTING 1 LINE(S)
--------------------------------------------------------------------------------
48 | WARNING | INI directive 'safe_mode' is deprecated in PHP 5.3 and forbidden in PHP 5.4.
48 | WARNING | INI directive 'safe_mode' is deprecated in PHP 5.3 and forbidden in PHP 5.4.
--------------------------------------------------------------------------------

25. Common apps - MediaWiki
FILE: /usr/src/mediawiki-1.19.8/includes/GlobalFunctions.php
--------------------------------------------------------------------------------
FOUND 0 ERROR(S) AND 1 WARNING(S) AFFECTING 1 LINE(S)
--------------------------------------------------------------------------------
2705 | WARNING | The use of function dl is discouraged in PHP version 5.3 and
| | discouraged in PHP version 5.4 and discouraged in PHP version
| | 5.5
--------------------------------------------------------------------------------

26. Common apps – Wordpress (latest)
FILE: /usr/src/wordpress/wp-admin/includes/class-pclzip.php
--------------------------------------------------------------------------------
FOUND 2 ERROR(S) AFFECTING 2 LINE(S)
--------------------------------------------------------------------------------
5340 | ERROR | The use of function set_magic_quotes_runtime is discouraged in
| | PHP version 5.3 and forbidden in PHP version 5.4 and forbidden
| | in PHP version 5.5
5371 | ERROR | The use of function set_magic_quotes_runtime is discouraged in
| | PHP version 5.3 and forbidden in PHP version 5.4 and forbidden
| | in PHP version 5.5
--------------------------------------------------------------------------------
FILE: /usr/src/wordpress/wp-includes/SimplePie/Item.php
--------------------------------------------------------------------------------
FOUND 0 ERROR(S) AND 1 WARNING(S) AFFECTING 1 LINE(S)
--------------------------------------------------------------------------------
125 | WARNING | INI directive 'zend.ze1_compatibility_mode' is deprecated in
| | PHP 5.3 and forbidden in PHP 5.4.
--------------------------------------------------------------------------------
FILE: /usr/src/wordpress/wp-includes/wp-db.php
--------------------------------------------------------------------------------
FOUND 16 ERROR(S) AFFECTING 16 LINE(S)
--------------------------------------------------------------------------------
641 | ERROR | Extension 'mysql_' is deprecated since PHP 5.5 - use mysqli
| | instead.
646 | ERROR | Extension 'mysql_' is deprecated since PHP 5.5 - use mysqli
| | instead.

27. PHP 7 rules status
Under development
Lots of work !

28. Changes for PHP 7 – deprecated functionality
PHP4 style constructors
Static calls to non-static methods
password_hash salt option

29. Changes for PHP 7 – new functionality
scalar type declaration
return type declaration
null coalescing operator
spaceship operator
constant arrays in define
anonymous classes
unserialize filter variable
IntlChar class
Group use declaration
Generator return expression
Generator delegation
intdiv function
session_start options
preg_replace_callback_array function
random_bytes and random_int functions

30. Changes for PHP 7 – backwards incompatibility
Variable handling interpretation
Empty list assignments
Array ordering when using by reference assignment
global keyword with variable variables no longer allowed
Function parenthesis warning
foreach internal array pointer changes
foreach by-value and by-reference changes
Negative bitshifts
Removed functions call_user_method, call_user_method_array, mcrypt_generic_end,
mcrypt_ecb(), mcrypt_cbc, mcrypt_cfb, mcrypt_ofb, datefmt_set_timezone_id,
IntlDateFormatter::setTimeZoneID, set_magic_quotes_runtime,
magic_quotes_runtime, set_socket_blocking, imagepsbbox, imagepsencodefont,
imagepsextendfont, imagepsfreefont, imagepsloadfont, imagepsslantfont,
imagepstext
Onwards to page 2...

31. Changes for PHP 7 – backwards incompatibility
Removed INI directives always_populate_raw_post_data, asp_tags and
xsl.security_prefs
New objects assigned by reference removed
New reserved keywords bool, int, float, string, NULL, TRUE, FALSE, resource,
object, mixed and numeric
Functions with multiple parameters with same name not allowed
Switch statements with multiple defaults not allowed
$HTTP_RAW_POST_DATA removed
# comments in INI files removed (only tested for php.ini)
mktime and gmmktime no longer support is_dst parameter
preg_replace no longer supports e
setlocale no longer supports category as string

32. Changes for PHP 7 – backwards incompatibility
Several new built-in functions, classes, interfaces and
exceptions
Many new global constants
Many removed extensions
Loosening reserved word restrictions (in some places)

33. PHP 7 rules status
Should be completed by end of December
Might be sponsored :-)

34. Conclusion
No 100% detection
But : 95% automation = lots of time saved !
First : PHPCompatibility on local machine
Then : use your CI/test environment and run unit tests
Start upgrading !

35. Questions ?

36. Questions ?

37. We're hiring !
Looking for a challenge ?
Want to do more than just code all day ?
→ http://cu.be/jobs

38. Thanks !