#14134 [Sus->WFx]: Literal -2147483648 should be an int, not a double.
| From: | sniper@php.net | Date: | Fri, 25 Apr 2003 16:25:04 +0000 |
| Subject: | #14134 [Sus->WFx]: Literal -2147483648 should be an int, not a double. | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-38382@lists.php.net to get a copy of this message | ||
ID: 14134
Updated by: sniper@php.net
Reported By: at217 at chebucto dot ns dot ca
-Status: Suspended
+Status: Wont fix
Bug Type: Scripting Engine problem
Operating System: Linux
PHP Version: 4.0.6
New Comment:
Just one oddity we have to live with:
http://www.php.net/manual/en/language.types.integer.php
Previous Comments:
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[2001-12-12 15:47:39] derick@php.net
Changing this into a suspended scripting engine problem, as the bug
lies in Zend. It is possible to change te parsing, but this will need a
lot of adjustments in it. That's why I'm suspending it too.
Derick
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[2001-11-26 14:42:58] derick@php.net
s/unsigned/signed in my text... I was sleeping I think :)
Derick
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[2001-11-26 14:35:08] at217 at chebucto dot ns dot ca
Derick,
Can you tell me where this code is so I can have a look? I'm a little
confused about your comment about conversion to unsigned integers.
First, I believe strtol converts to a signed integer (and, as used in
intval, it does work correctly). But 2147483648 actually is a valid
unsigned long. If the conversion is failing, it must be trying to
convert to a signed integer.
As for the workaround, creating constants INT_MIN and INT_MAX is
exactly what I did, although you still have to be careful when creating
INT_MIN. It must be something like:
define( "INT_MIN", -2147483647 - 1 );
define( "INT_MAX", 2147483647 );
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[2001-11-26 02:37:19] derick@php.net
Ok, as I have no time to look into a fix (if it's even do-able), I'll
explain here why it happens:
The parser embedded in PHP, does not take "-2147483648" as a string to
convert (with strtol) to a unsigned integer, but it instead does this:
1. it tries to convert "2147483648" to a unsigned integer (which
fails)
2. it tries to substract this from 0, ie. 0 - 2147483648.
Because the conversion to a unsigned long fails in the first step, it
gets converted to a floating point number, which is substracted from
0.
A way to solve this can be to add constants for these outher limits,
ie. INT_MIN (for -2147483648) and INT_MAX (for 2147483647).
Derick
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[2001-11-20 02:34:05] at217 at chebucto dot ns dot ca
When assigning the value -2147483648 to a variable, the variable
becomes a double, even though the value is within the range of
integers. In fact, assigning -2147483647 - 1 works, as does using
intval("-2147483648").
The following script demonstrates, and can be accessed at
<http://www.randomsample.org/tests/test-int-min.php>.
<?php
$int_max = 2147483647;
$int_min = -2147483648;
$int_min_alt = -2147483647 - 1;
?>
<html><head><title>Test INT_MIN</title></head>
<body>
<p>Type of "2147483647": <?php echo gettype( $int_max ); ?>
(value = <?php echo $int_max; ?>)</p>
<p>Type of "-2147483648": <?php echo gettype( $int_min ); ?>
(value = <?php echo $int_min; ?>)</p>
<p>Type of "-2147483647 - 1": <?php echo gettype( $int_min_alt ); ?>
(value = <?php echo $int_min_alt; ?>)</p>
</body>
</html>
This is an ISP-provided build, but the configure line from phpinfo()
is:
'./configure' '--with-config-file-path=/etc' '--enable-safe-mode=yes'
'--enable-force-cgi-redirect=yes' '--with-gdbm' '--with-mysql'
'--with-exec-dir=/www/cgi-bin' '--bindir=/www/cgi-bin' '--enable-ftp'
'--enable-trans-sid' '--with-gd=/usr' '--with-zlib=/usr'
'--with-jpeg-dir=/usr' '--enable-gd-native-ttf' '--with-png-dir=/usr'
'--with-ttf=/usr/lib'
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Edit this bug report at http://bugs.php.net/?id=14134&edit=1