rfc:notice-for-non-valid-array-container

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rfc:notice-for-non-valid-array-container [2016/08/15 15:04] – bp1222rfc:notice-for-non-valid-array-container [2019/07/10 12:20] (current) – Implemented nikic
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 ====== PHP RFC: E_WARNING for invalid container read array-access ====== ====== PHP RFC: E_WARNING for invalid container read array-access ======
-  * Version: 0.2 +  * Version: 1.0 
-  * Date: 2016-08-10+  * Date: 2016-08-16
   * Author: David Walker (dave@mudsite.com)   * Author: David Walker (dave@mudsite.com)
-  * Status: Under Discusson+  * Status: Implemented (in PHP 7.4)
   * First Published at: http://wiki.php.net/rfc/notice-for-non-valid-array-container   * First Published at: http://wiki.php.net/rfc/notice-for-non-valid-array-container
  
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                      // Output would be:                      // Output would be:
                      // Warning: Variable of type integer does not accept array offsets                      // Warning: Variable of type integer does not accept array offsets
 +                     
 +// Brought up during vote:
 +$a = [null];
 +$c = null;
 +var_dump($a[0][0] + $c[0]);  // This will through 2 E_WARNINGS, First would be $a[0][0]
 +                             // For the same reason as above, $a[0] is rightfully NULL
 +                             // and accessing [0] on null is invalid.  The second, 
 +                             // would be $c[0] for the same reason.
 +                             // Output:
 +                             // int(0)
 </file> </file>
  
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 This RFC aims to limit the quantity of warnings on a single line, however, large projects may have many locations that might need variable type checking around unknown container access.  Typically, one might assume access of a variable to be an array or object, and could do checks to make sure the variable about to be accessed is an array, or an object. This RFC aims to limit the quantity of warnings on a single line, however, large projects may have many locations that might need variable type checking around unknown container access.  Typically, one might assume access of a variable to be an array or object, and could do checks to make sure the variable about to be accessed is an array, or an object.
 +
 +===== Performance Impact =====
 +Test run was:
 +<file php>
 +<?php
 +$a = false;
 +for ($i = 0; $i < 1000000; $i++) {
 +    $a[0];
 +}
 +</file>
 +
 +Execution Time (DualCore 3ghz; 2g ram)
 +  * Current Master : ~0.09s (~489m operations)
 +  * Current Master w/RFC Displaying Warnings: ~33.25s (~7.799b operations)
 +  * Current Master w/RFC Hiding Warnings: ~0.82s (~4.091b operations)
 +
 +We can see there is a significant increase in operations on huge loads.  However, I wouldn't suspect 1m of these errors per request almost ever.  So, yes there is; but I'd call it useful information overhead.
  
 ===== Proposed PHP Version(s) ===== ===== Proposed PHP Version(s) =====
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   * ''foreach(list($a, $b) = each($foo))'' -- Would need to prevent warn on 'final' null each   * ''foreach(list($a, $b) = each($foo))'' -- Would need to prevent warn on 'final' null each
  
-Per discussion on the [[https://github.com/php/php-src/pull/2031#issuecomment-238366706|PR]] I have limited this RFC to not raise warings when setting any value by use of list().+Per discussion on the [[https://github.com/php/php-src/pull/2031#issuecomment-238366706|PR]] I have limited this RFC to not raise warnings when setting any value by use of list().
  
 ==== Reference Assignment Access ==== ==== Reference Assignment Access ====
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 ===== Proposed Voting Choices ===== ===== Proposed Voting Choices =====
-No syntax is changed, a vote of 50%+1 will be necessary+Requires 2/3 Vote
 <doodle title="E_WARNING for invalid container read array-access" auth="bp1222" voteType="single" closed="true"> <doodle title="E_WARNING for invalid container read array-access" auth="bp1222" voteType="single" closed="true">
    * Yes    * Yes
    * No    * No
 </doodle> </doodle>
 +Vote Start: 2016-08-16 15:36
 +
 +Vote End:   2016-08-31 23:59
  
 ===== Patches and Tests ===== ===== Patches and Tests =====
rfc/notice-for-non-valid-array-container.1471273442.txt.gz · Last modified: 2017/09/22 13:28 (external edit)

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