Question about Readonly::XS.pm..$MAGIC_COOKIE 1

[whn]

Hi, Experts,

I have been using Readonly.pm for quite some time on various platforms, such Solaris, AIX, Redhat, SUSE 9 & 10 with perl 5.8.8 or lower and never had any problems until I started running my codes (CLI) on SUSE 11 with perl 5.10.0.

The error I got:

String found where operator expected at XS.pm line 36, near "Carp::croak "Readonly::XS is not a standalone module. You should not use it directly.""
(Do you need to predeclare Carp::croak?)


For your convenience, below is the part of XS.pm:

package Readonly::XS;

use strict;
use warnings;
use vars qw($VERSION $MAGIC_COOKIE %PL_COMPAT);

$VERSION = '1.04';

require XSLoader;
XSLoader::load('Readonly::XS', $VERSION);

# It is an error to use this from any module but Readonly.
# But sooner or later, someone will.
BEGIN
{
    no warnings 'uninitialized';
    if ($MAGIC_COOKIE ne "Do NOT use or require Readonly::XS unless you're me.")
    {
        require Carp;
        Carp::croak "Readonly::XS is not a standalone module. You should not use it directly."; [b]# Line 36!![/b]
    }
}

BTW, I got this error only on SUSE 11 (perl 5.10.0). Could someone kindly explain to me how the variable $MAGIC_COOKIE is set and why this error is only seen on SUSE 11? How to fix this problem?

Many thanks.

 

[Annihilannic]

MAGIC_COOKIE is set early in Readonly.pm, which calls Readonly::XS if it is available on your system.

I think you need to update Readonly::XS, sounds like this bug describes your problem.

I can reproduce the problem in Cygwin with perl 5.10, and making the same change fixes it for me too:

$ perl -e 'if (0) { require Carp; Carp::croak "a test string"; }'
String found where operator expected at -e line 1, near "Carp::croak "a test string""
        (Do you need to predeclare Carp::croak?)
syntax error at -e line 1, near "Carp::croak "a test string""
Execution of -e aborted due to compilation errors.

$ perl -e 'if (0) { require Carp; Carp::croak("a test string"); }'

$

Annihilannic.

 

[whn]

Thank you, Annihilannic.

That helps a lot!!

A follow-up question: why didn't I have this problem with perl 5.8.8?

Thanks again for your help.

 

[Kirsle]

5.10.0 is more strict with certain syntaxes than 5.8.8 was.

Kirsle.net | My personal homepage

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