Migration is one of the most scary migration: it requires sharp tools to find incompatibilities in the code, and even more know-how to adapt it to the future environnement. During this workshop, we'll work on your code, systematically targeting incompatibilities and scouting for opportunities to use the new features. Along the way, we'll get right of dead code, slow routines and instable functions. After querying the code, we'll discuss the various solutions and learn even more about using PHP for the best.

1. Preparing for PHP 7.1 workshop
Damien Seguy @exakat
Warsaw, Poland, October 2016

2. Full ahead to PHP 7. 1
• Changing version is always a big challenge
• Backward incompatibilities
• New features
• Learn, spot, fix, repeat
0

3. Speaker
• Damien Seguy
• CTO at exakat
• Static code analysis for PHP

4. Synopsis
• What is in the next version ?
• Where in my code ?
• How to replace this ?
• Get documentation
• Find issue
• Fix code

5. Migration to PHP 7.1
• Migration to PHP 7.0, 7.1 and 7.2 / 8.0
• From PHP 5.6
• No framework, no libraries
• Tools, experience, discipline

6. Destination

7. Living on the edge
• http://php.net/manual/en/migration70.php
• Online
• UPGRADING TO PHP 7
• Free Book, PDF
• Davey Shafik is RM for PHP 7.1
• Lots of blogs and articles

8. Living on the bleeding edge
https://github.com/php/php-src/blob/master/
UPGRADING
https://github.com/php/php-src/blob/master/NEWS
https://wiki.php.net/rfc
http://bugs.php.net/

14. • PHP has 3 phases
• syntax
• definitions
• execution
Where does code break?
Checked with phplint
Checked with tests
Checked code review

15. <?php
function splitNames($fullname, $fullname) {
list($first, $last) = split($fullname, ' ');
}
?>
Where will code break?
SyntaxDefinitionsExecution

16. Tools for migration
• Your own experience with your code
• Lint
• Search
• Static analysis
• Logs

17. Linting PHP 7

18. PHP linting
• command line : php -l filename.php
• Spot parse errors
• Works on files only :
• For directories, see composer phplint/phplint

19. PHP linting
Error messages
in PHP
0
550
1100
1650
2200
5.0 5.1 5.2 5.3 5.4 5.5 5.6 7.0 7.1 7.2
Total Distinct

20. Backward unlintable code

21. Code focused on current versions

22. Backward unlintable code

23. Redefinition of parameter
<?php
function foo($a, $a, $a) {
print $a."n";
}
foo('x', 'y', 'z');
?>

24. Switch statements only contain one default clause
<?php
switch($x) {
case '1' :
break;
default :
break;
default :
break;
case '2' :
break;
}

25. Switch statements may only contain one default
clause
switch($x) {
case 1 :
break;
case 0+1 :
break;
case '1' :
break;
case true :
break;
case 1.0 :
break;
case $y :
break;
}

26. Deprecated features
• Not happening if a parent case has a __constructor()
• Not happening if the class is in a namespace
• Use the E_DEPRECATED error level while in DEV
Methods with the same name as their class will not
be constructors in a future version of PHP; foo has
a deprecated constructor

27. php -l with other versions
• syntax error, unexpected 'new' (T_NEW)
• Assigning the return value of new by reference is
deprecated (PHP 5.6)
• PHP 7 -> PHP 5.6
$o =& new Stdclass();

28. Migration to PHP 7.1
• Lint with
• PHP 7.1
• PHP 7.2 (or src)
• PHP 5.6 (current), PHP 7.0
• PHP 5.5, 5.4,… (manual)

29. PHP 7 linting
• Pre-commit
• Use different versions
• Be ruthless with unlintable files

30. • PHP has 3 phases
• syntax
• definitions
• execution
Where does code break?
Checked with phplint
Checked with tests
Checked code review

31. Static analysis

32. Presentation
• Review code without executing it
• Common in C/C++, Java, Javascript
• Hot subject coming to PHP

33. GREP/SEARCH
• Any searching facility
• Pro : High speed, great for keyword search, universal
• Cons : Little repeat value, no PHP semantics

34. Grep on PHP code
1318 reports
doc/_ext/configext.py: parts = text.split("']['")
js/codemirror/lib/codemirror.js: var change = {from: pos, to: pos, text: splitLines(t
po/zh_CN.po:"example: address can be split into street, city, country and
libraries/Advisor.php: public static function splitJustification($rule)
libraries/plugins/ImportCsv.php: $tmp = preg_split('/,( ?)/', $csv_columns);
libraries/Config.php: // split file to lines

35. Static analysis
PHP 5 / 7
Calisthenics
ClearPHP
Performance
 
 


36. Static analysis tools
PHP7mar
PHP7cc
Phan
Exakat
PHP inspections

37. PHP7mar
• PHP 7 Migration Assistant Report (MAR)
• Alexia : https://github.com/Alexia/php7mar
• Works with regex
• Produces a .md file

38. 12 results

39. PHP7cc
• PHP 7 Compatibility Checker
• Authored by sstalle
• https://github.com/sstalle/php7cc
• PHP 5, works with "nikic/php-parser": "~1.4"
• Display to stdout

40. 8.506s 3 results 27 analysis
php ~/.composer/vendor/bin/php7cc library/
File: /Users/famille/Desktop/analyze/library/Analyzer/Analyzer.php
> Line 231: Function argument(s) returned by "func_get_args" might have been modified
func_get_args();
File: /Users/famille/Desktop/analyze/library/Analyzer/Functions/MarkCallable.php
> Line 32: Nested by-reference foreach loop, make sure there is no iteration over the same array
foreach ($lists as $id => &$function) {
}
File: /Users/famille/Desktop/analyze/library/Tasks/Analyze.php
> Line 118: Possible adding to array on the last iteration of a by-reference foreach loop
$dependencies[$v] = $dep;
Checked 873 files in 8.506 seconds

41. PHAN
• Static analysis for PHP
• Inited by Rasmus, under work at Etsy
• https://github.com/etsy/phan
• PHP 7 only, with ext/ast
• php ~/.composer/vendor/bin/phan -f phan.in -3 vendor -
o phan.out

43. 11.244s 333 results
PhanUndeclaredProperty Reference to undeclared property processed
PhanUndeclaredProperty Reference to undeclared property stdclass->results
PhanNonClassMethodCall Call to method relateTo on non-class type null
PhanStaticCallToNonStatic Static call to non-static method loadercypher::saveTokenCounts() defined at library//L
PhanAccessPropertyProtected Cannot access protected property tokenizertoken::$alternativeEnding
PhanTypeMismatchArgument Argument 1 (atom) is string but analyzerstructuresuseconstant::atomfunctionis() t
PhanUndeclaredClassMethod Call to method __construct from undeclared class reportsxmlwriter
PhanUndeclaredVariable Variable $r is undeclared
84 analysis

44. Exakat
• Static analysis engine for PHP
• https://github.com/exakat/exakat
• PHP 5.2 to 7.2; Uses Neo4j 2.3 and Gremlin 3
• php exakat.phar project -p name

45. 20 mins6798 results260 analysis

46. PHP inspections
Static analysis engine for within the IDE
Vladimir Reznichenko
https://bitbucket.org/kalessil/phpinspectionsea
Written in Java
Runs from within PHPstorm

48. Write your own?
• https://github.com/exakat/php-static-analysis-tools.git
• PHP 7 : use ext/ast
• PHP 5 :"nikic/php-parser"
• Avoid regex (but it does work)

49. PHP 7 : what changes?
• Incompatible changes
• New features
• Features/Incompatibilities from PHP 5.6 => 7.2

50. How to spot issues?
• Code knowledge
• lint
• Grep / Search
• Static analysis
• Logs / error_reporting
• Unit Tests
What to replace
them with ?

51. Incompatibilities

52. Incompatibilities
• Removed features
• Added features
• Collateral damages

53. Removed features

54. Removed extensions
• Extensions
• ereg
• mssql
• mysql
• sybase_ct
• mcrypt (7.1)

55. Removed extensions
• ext/ereg
• ereg
• ereg_replace
• split
• sql_regcase

56. Removed functions
• call_user_method()
• call_user_method_array()
• Repleacable by $funcname
• Replaced by call_user_func() and call_user_func_array()
• Partially replaced by variadic

57. Removed variables
• $HTTP_RAW_POST_DATA
• Replace it by php://input
• php://input is now reusable
• Since PHP 5.5

58. Removed INI
• sql.safe_mode (PHP 7.2)
• mbstring.internal_encoding
• mbstring.http_output
• mbstring.http_input
• iconv.internal_encoding
• iconv.input_encoding
• iconv.output_encoding
default_charset
}

59. default_charset
• htmlentities()
• PHP 5.3 : ISO-8859-1
• PHP 5.4 : UTF-8
• PHP 5.6 : default_charset (also UTF 8)

60. Where to look for ?
• default_charset
• Search for ini_set, ini_get, ini_get_all, ini_restore, get_cfg_var
• Search in php.ini, .htaccess
• Search for htmlentities(), html_entity_decode() and htmlspecialchars()

61. Preg_replace and /e
• preg_replace(‘/ /e’, ‘evaled code’, $haystack)
• replaced by
• preg_replace_callback_array()
preg_replace(‘/ /e’, ‘evaled code’, $haystack)
preg_replace_callback_array([‘/ /’ => $closure],
$haystack)
preg_replace_callback(‘/ /’,
$closure],
$haystack)

62. preg_replace_callback_array
<?php
$code = "abbbb";
$spec = 'c';
echo preg_replace_callback_array(
array(
"/a/" => function($matches) {
return strtoupper($matches[0]);
},
"/b/" => function($matches) use ($spec) {
static $i = 0;
$i++;
return "B$i$spec";
}
), $code);
AB1cB2cB3cB4c

63. preg_replace()
<?php
$code = "abcde";
echo preg_replace(
array( '/a/', '/b/'),
array( 'f' , 'g'),
$code);
fgcde

64. mb_eregi?_replace also drops /e in 7.2
<?php
$code = "abcde";
echo preg_replace(
array( '/a/', '/b/'),
array( 'f' , 'g'),
$code);
fgcde

65. Can't call dynamically!
• $func()
• call_user_func()
• array_map()
• or similar
• extract()
• compact()
• get_defined_vars()
• func_get_args()
• func_get_arg()
• func_num_args()
• parse_str() with one argument
• mb_parse_str() with one argument
• assert() with a string argument

66. Added features

67. Added definitions
Functions Classes Constants
5.3 40 2 80
5.4 0 9 78
5.5 12 11 57
5.6 1 10 10
7.0 10 10 41
7.1 7 2 15
7.2 0 0 0
Total 766 92 1163

68. Name impact
• get_resources(), intdiv(), is_iterable(), mb_scrub()
• PREG_JIT_STACKLIMIT_ERROR
• class Date (from PHP 5.1)
• Error (new class in PHP 7)

69. New functions
• intdiv()
• get_resources()
• random_bytes(), random_int()
• error_clear_last()
• gc_mem_caches()
• preg_replace_callback_array()

70. Collaterals

71. Invalid octals are invalid
• Upgraded from silent to Fatal error
PHP Parse error: Invalid numeric literal in test.php
<?php
$x = 0890;

72. More invalid octals in strings
<?php
var_dump("000" === "400");
• PHP 7.1
https://wiki.php.net/rfc/octal.overload-checking

73. Invalid numeric are signaled
PHP 7.1
Notice: A non well formed numeric value encountered in
<?php
echo "1 monkey" + "2 bananas";

74. More reserved keywords
• bool, int, float, string, null, true, false are no
more available for class / interface / traits names
mixed, numeric, object, resource
are reserved for future use
void
is reserved in 7.1

75. More relaxed keywords
• Almost all PHP keywords are now authorized inside
classes
• Methods and constants
• Except for class, which can't be a class constant name.
<?php
class foo {
const instanceof = 1;
function use() {
$this->while(4) + foo::instanceof;
}
}

76. More strict keywords
• $this is not available anymore
• Not as argument
• Not as variable
• Not as global
• Not as static
• Not as property
• Not as reference
• Not via extract()
<?php
function foo($this) {
echo $this;
}

77. Strings may be invalid
• Upgraded to Fatal error
<?php
echo "u{1F418}n";
> php56 test.php
u{1F418}
> php70 test.php
🐘
<?php
echo "niu{119} mu{f3}wiu{119} pu{f3} po
u{142}u{15b}";
//nię mówię pó połśku

78. Strings may be invalid
• Upgraded to Fatal error
<?php
echo "u{Yes}n";
PHP Parse error:
Invalid UTF-8 codepoint escape sequence
in test.php on line 3
u{

79. Hexadecimal numeric strings
• Also, -0 !!
<?php
var_dump(1 + 0xf);
var_dump(1 + "0xf");
$ php56 test.php
int(16)
int(16)
$ php70 test.php
int(16)
int(1)

80. Warning for strings (7.1)
Upgraded to Fatal error
<?php
print "2" + "4";
print "3 elephpants" + "4 dolphins";
print "2" + "d4 d";
6
7
2
Warning: A non-numeric value encountered

81. Exceptions
• Upgraded to Fatal error
Throwable
Exception
LogicException RuntimeException
BadFunctionCall
Exception
BadMethodCall
Exception
DomainException
InvalidArgument
Exception
OutOfRange
Exception
OutOfBou
ndsExcep
tion
Overflow
Exception
RangeExcep
tion
Error
ParseError
DivisionBy
ZeroError
Assertion
Error

82. Exceptions
• Exception is not the top exception type anymore
• It is now the 'throwable' interface
• Impact on Exception handler
• Avoid type hinting until moved to PHP 7
• Impact on Error handler
• Impact on catch() clauses

83. More catching exceptions
• Parser errors now throw a ParseError object. Error
handling for eval()
<?php
try {
eval($somePHPcode);
} catch( ParseError $e) {
log($e->getMessage());
// attempt to fix this or error handling
}

84. More catching exceptions
Parser errors now throw a ParseError object. Error
handling for eval()
<?php
try {
$file = new finfo(FILEINFO_NONE,$magic_file);
} catch( ParseError $e) {
log($e->getMessage());
// attempt to fix this or error handling
}

85. And more catching exceptions
Parser errors now throw a ParseError object. Error
handling for eval()
<?php
try {
$random = random_bytes(10);
} catch( TypeError $e) {
// invalid parameter
} catch( Error $e) {
// invalid length
} catch( Exception $e) {
// no source of randomness
}

86. Even more catching exceptions
<?php
try {
attemptSomething();
} catch (RuntimeException $e) {
fixSomething();
} catch (InvalidArgumentException $e) {
fixSomething();
} catch (BadFunctioncallException $e) {
fixSomethingElse();
}

87. Even more catching exceptions
Federate error catching in catch clause
<?php
try {
attemptSomething();
} catch (RuntimeException|
InvalidArgumentException|
BadFunctioncallException $e) {
fixSomething();
}

88. Even more catching exceptions
<?php
//try really harder
try {
attemptSomething();
} catch (Exception $e) {
attemptSomething();
}

89. Negative string offset (7.1)
• Upgraded to Fatal error
<?php
$string = "abcde";
print $string[-3];
print "$string[3]";
print "$string[-2]";
c
d
Parse error: syntax error, unexpect
(T_STRING) or variable (T_VARIABLE)

90. PHP 7.1 : list() with keys =>
<?php
$array = ['a' => 1, 'b' => 5, 'c' => 3];
// Assigns to $a, $b and $c in the same order
list($a, $b, $c) = $array;
// Assigns to $a, $b and $c from the keys
//"a", "b" and "c", respectively
list("a" => $a, "c" => $c, "b" => $b) = $array;
list("a" => $a, "b" => $b, "c" => $c) = $array;
list("c" => $c, "a" => $a, "b" => $b) = $array;

91. Short syntax for list()
<?php
$array = ['a' => 1, 'b' => 5, 'c' => 3];
["a" => $a, "b" => $b, "c" => $c] = $array;
// Works even when nested
$array = [['a' => 1, 'b' => 5], ['c' => 3]];
[["a" => $a, "b" => $b], ["c" => $c]] = $array;

92. Call-time pass-by-reference
• References are in the function signature
• Deprecated warnings until PHP 7
• Upgraded to Parse error in PHP 7
<?php
$a = 3;
function f($b) {
$b++;
}
f(&$a);
print $a;
?>
PHP Parse error: syntax error, unexpected '&' in …

93. Incompatible context
<?php
class A {
function f() { echo get_class($this); }
}
A::f();
?>
Notice: Undefined variable: $this inA
Deprecated: Non-static methodA::f() should not be called statically
Notice: Undefined variable: $this inA

94. Easy to spot
• Use the E_DEPRECATED or strict while in DEV
Strict Standards: Non-static method A::f()
should not be called statically in test.php on
line 6
Deprecated: Non-static method A::f() should
not be called statically in test.php on line 6

95. Changed behavior

96. Changed behavior
• Indirect expressions

97. func_get_arg()
• func_get_arg() and func_get_args() now return current argument values
<?php
function foo($a, $b, $c) {
print_r(func_get_args());
++$a;
print_r(func_get_args());
}
foo(1,2,3);
Array
(
[0] => 1
[1] => 2
[2] => 3
)
Array
(
[0] => 2
[1] => 2
[2] => 3
)

98. Usort()
<?php
$array = array(
'foo',
'bar',
'php'
);
usort($array, function($a, $b) {
return 0;
}
);
print_r($array);
Array
(
[0] => php
[1] => bar
[2] => foo
)
Array
(
[0] => foo
[1] => bar
[2] => php
)
PHP 5
PHP 7

99. Automatically fixed
It is not safe to rely on the system's timezone
settings. You are required to use the
date.timezone setting or the
date_default_timezone_set() function. In case
you used any of those methods and you are
still getting this warning, you most likely
misspelled the timezone identifier.

100. New features

101. New features
• Breaks backward compatibility sometimes
• FUD
• Search for places to apply them like for incompatibilities

102. New features
• Fixing
• Modernization
• New features

103. Fixing

104. Don't hide in parentheses
<?php
function getArray() {
return [1, 2, 3];
}
function squareArray(array &$a) {
foreach ($a as &$v) {
$v **= 2;
}
}
// Generates a warning in PHP 7.
squareArray((getArray()));
?>
• Parenthesis in
arguments won't
mask error anymore

105. Constant arrays
• Lots of properties should be constants
<?php
class Version {
const SUPPORTED = ['1.0', '1.1', '2.0', '2.1'];
private $an_array = [1,2,3,4];
public function isSupported($x) {
return isset(Version::SUPPORTED[$x]);
}
}

106. Modernization

107. Foreach update the actual array
<?php
$array = [0];
foreach ($array as $k => &$val) {
print "$kn";
$array[] = 1;
}
?>
0
1
2
3
4
5
6
7
8
9
10
11
0
PHP 5 PHP 7

108. Closure binding
• Code automation
• Keep it simple
• Won’t accept functioncalls
• Won't accept variables
<?php
class Hello {
private $hello = "Hello";
function makeClosure() {
return function() {
echo $this->hello;
};
}
$obj = new Hello();
$closure = $obj->makeClosure();
$closure();

109. Closure binding
• Code automation
• Keep it simple
• Won’t accept functioncalls
• Won't accept variables
<?php
class {
private $hello = " ";
}
$obj = new Hello();
$closure = $obj->makeClosure();
$nihao = new ();
$closure2 = $closure->bindTo($nihao);
$closure2();

110. Closure binding
• Code automation
• Keep it simple
• Won’t accept functioncalls
• Won't accept variables
<?php
$closure = function() {
echo $this->hello;
};
class {
private $hello = " ";
}
$nihao = new ();
$closure->call($nihao);

111. session_start($options)
<?php
// PHP 5.6
ini_set('session.name','session');
ini_set('session.gc_probability',1);
ini_set('session.gc_divisor',1);
session_start();
// PHP 7.0
session_start(['name' => 'session',
'gc_probability' => 1,
'gc_divisor' => 1 ]
);

112. dirname() second argument
<?php
$path = '/a/b/c/d/e/f';
// PHP 5.6
$root = dirname(dirname(dirname($x)));
// PHP 7
$root = dirname($path, 3);
?>

113. Parameters evolution (7.1)
• get_headers() has an extra parameter
• Passing a custom stream context
• getenv() doesn't need parameter
• all the current environment variables will be returned

114. Really new

115. Null-coalesce
• Shorter way to give a test for NULL and failover
<?php
// PHP 5.6
$x = $_GET['x'] === null ? 'default' : $_GET['x'];
// PHP 7.0
$x = $_GET['x'] ?? 'default';
?>

116. Spaceship operator
• Very Cute <=>
• Replaces a lot of code
• Mainly useful for usort()
<?php
// PHP 5.6
if ($a > $b) {
echo 1;
} elseif ($a < $b) {
echo -1;
} else {
echo 0;
}
// PHP 7.0
echo $a <=> $b; // 0

117. Generators delegation
<?php
function factors($limit) {
yield 2;
yield 3;
yield from primeTill1000();
for ($i = 1001; $i <= $limit; $i += 2) {
yield $i;
}
}
$prime = 1357;
foreach (factors(sqrt($prime)) as $n) {
echo "$n ". ($prime % $n ? ' not ' : '') . " factorn";
}

118. Generators returns <?php
function factors($limit) {
return 'first';
yield 2;
return 'second';
yield 3;
return 'third';
yield 5;
}
$gen = factors(sqrt($prime));
foreach ($gen as $n) {
echo "$nn";
if ($n == 3) {break 1;}
}
print $gen->getReturn();
// second
• Generators returns
• The last return is accessible
• The generator returns the final state

119. Scalar typehint
• Whenever type is tested =>
<?php
function foo($x) {
if (!is_string($x)) {
throw new Exception('Type error while calling ' .
__FUNCTION__);
} ...
}
<?php
function foo(string $x) {
...
}

120. Scalar typehint back in 5.6
• Whenever type is tested =>
<?php
function foo(string $x) { }
foo('that');
Catchable fatal error: Argument 1 passed to
foo() must be an instance of string,
string given, called in file..

121. Various scalar typehint
• int, float
• string, bool
• true, false, null
• void (PHP 7.1)
• mixed, object,
resource, numeric
(RFU)
<?php
function foo(?int $a,
float $b,
float $c) : ?int {
return $a + $b + $c;
}
echo foo(null, 2,1); // 4
echo foo(1.2, 2, 1); // 4
echo foo(1, 2.2, 1); // 4
echo foo(1, 2.7, 1.4); // 5

122. Return type hint
<?php
function getData($login) : user {
if (userExists($login)) {
return userDetails($login);
} else {
return null;
}
}
• scalar, array, callable, class or interfaces
void (PHP 7.1)

123. Option for strict typing
<?php
// Enable strict types
declare(strict_types=1);
declare(encoding='ISO-8859-1');
declare(ticks=1);
namespace FooBar;
foo('that');

124. Minimum args in custom functions is Fatal error
scalar, array, callable, class or interfaces
void (PHP 7.1)
<?php
function foo(?int $a, float $b, float $c) {
return $a + $b + $c;
}
echo foo(2, 1);
Minimum args number Fatal error: Uncaught Error:
Too few arguments to function foo(), 2 passed in

125. Omitted
• Assertions
• Grouped assertions
• opening tags that were dropped

126. Summary
• Check the manuals
• PHP lint is your friend
• Search in the code
• Use static analysis tools

127. Thank you! Damien Seguy @exakat dseguy@exakat.io
https://www.exakat.io/

128. The end