[PHP-BUG] Bug #69091 [NEW]: assign by reference and math

[email protected] ("rstoll at tutteli dot ch")
Newsgroups php.standards
Message-ID <[email protected]>
From:             rstoll at tutteli dot ch
Operating system: 
PHP version:      5.6.6
Package:          PHP Language Specification
Bug Type:         Bug
Bug description:assign by reference and math

Description:
------------
assign by reference in conjunction with arithmetic does not result in a
syntax error as expected. The test script shows two examples. The first
one is correct according to the current implementation, but should
result in a parser error IMO. The second results in a parser error (how
it should be). 

It seems like the parser has a wrong precedence. I think the problem is
this line in the grammar:
http://lxr.php.net/xref/PHP_TRUNK/Zend/zend_language_parser.y#777

The langspec does not mention operator precedence explicitly (which
should be added IMO) but implicitly the =& operator can be found in the
section "Assignment Operator"
(https://github.com/php/php-langspec/blob/b1e7a65fb9c985a8114322330468b77fb955cfae/spec/19-grammar.md#assignment-operators)
which is further below than +

Test script:
---------------
$a = &$a + 1;
$a = 1 + &$a;

Expected result:
----------------
parser error in both cases or the precedence explanation needs to be
changed. 
Reading the spec I would assume the first line in the code above is
equivalent to:
$a = (&$a + 1);
and not
($a = &$a) + 1;




-- 
Edit bug report at https://bugs.php.net/bug.php?id=69091&edit=1
-- 
Try a snapshot (PHP 5.4):   https://bugs.php.net/fix.php?id=69091&r=trysnapshot54
Try a snapshot (PHP 5.5):   https://bugs.php.net/fix.php?id=69091&r=trysnapshot55
Try a snapshot (trunk):     https://bugs.php.net/fix.php?id=69091&r=trysnapshottrunk
Fixed in SVN:               https://bugs.php.net/fix.php?id=69091&r=fixed
Fixed in release:           https://bugs.php.net/fix.php?id=69091&r=alreadyfixed
Need backtrace:             https://bugs.php.net/fix.php?id=69091&r=needtrace
Need Reproduce Script:      https://bugs.php.net/fix.php?id=69091&r=needscript
Try newer version:          https://bugs.php.net/fix.php?id=69091&r=oldversion
Not developer issue:        https://bugs.php.net/fix.php?id=69091&r=support
Expected behavior:          https://bugs.php.net/fix.php?id=69091&r=notwrong
Not enough info:            https://bugs.php.net/fix.php?id=69091&r=notenoughinfo
Submitted twice:            https://bugs.php.net/fix.php?id=69091&r=submittedtwice
register_globals:           https://bugs.php.net/fix.php?id=69091&r=globals
PHP 4 support discontinued: https://bugs.php.net/fix.php?id=69091&r=php4
Daylight Savings:           https://bugs.php.net/fix.php?id=69091&r=dst
IIS Stability:              https://bugs.php.net/fix.php?id=69091&r=isapi
Install GNU Sed:            https://bugs.php.net/fix.php?id=69091&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=69091&r=float
No Zend Extensions:         https://bugs.php.net/fix.php?id=69091&r=nozend
MySQL Configuration Error:  https://bugs.php.net/fix.php?id=69091&r=mysqlcfg
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