Re: AutoLoader issues with Inline::CPP

[Sisyphus]

----- Original Message ----- 
From: "Erik Hollensbe" <[EMAIL PROTECTED]>
To: <inline@perl.org>
Sent: Wednesday, June 18, 2008 2:15 AM
Subject: AutoLoader issues with Inline::CPP


Greetings folks...

I'm having a problem with an Inline::CPP module I'm writing. It seems that
it's trying to local an autosplit routine in the _Inline dir that doesn't
exist after Inline does its initial magic.

Here's the actual error:

Can't locate auto/MIME/KDE/version.al in @INC (@INC
contains: /home/erikh/git/mime-kde/_Inline/lib


I can reproduce the behaviour with:

---------------------------------------------
package MIME::KDE;
use warnings;

use Inline CPP => <<'EOC';

#include <iostream>

namespace MIME {
   namespace KDE {
       const char* version(void) {
           return "my version is 0.01";
       }
   }
}
EOC

$z = MIME::KDE::version();
print $z, "\n";
----------------------------------------

Normally, for a package named MIME::KDE, the shared object would be 
/auto/MIME/KDE/KDE.so, and the version() function would be found. But in 
this instance, the shared object that Inline::CPP builds is 
auto/MIME/KDE_xxxx/KDE_xxxx.so (where xxxx are hex digits).

If I'm on the right track you should have:
/home/erikh/git/mime-kde/_Inline/lib/auto/MIME/KDE_xxxx/KDE_xxxx.so.

I think this is the root of the problem.
The "AUTOLOAD" and "version.al" references are a red herring. The last thing 
perl does in its attempt to find the missing version function is to look for 
version.al - which it then reports as missing (as it doesn't exist). But the 
fact that version.al doesn't exist has nothing to do with the problem. (It 
*shouldn't* exist ... the real problem is that the version function can't be 
found.)

Did you actually install the module in the usual way ? (ie 'perl 
Makefile.PL', 'make install'.)
There's a demo module called Math::Simple shipped with the Inline-0.44 
source. It works fine when installed by running 'perl Makefile.PL', 'make 
test' and 'make install' - you'll find the Math::Simple source in 
Inline-0.44modules/Math/Simple folder. Perhaps you just need to emulate what 
is being done there in order to get things to work. (Or perhaps there are 
some Inline::CPP specific things in relation to the use of 'namespace' that 
compilcate the matter .... I don't know, but the more I think about it, the 
more likely this seems.)

Another option that should work is to use InlineX::CPP2XS to convert your 
Inline::CPP code to a normal XS-type distro (and remove the Inline 
dependency altogether).

Just rename mimelib.cpp to KDE.cpp, cd to the directory that is one level up 
from src/KDE.cpp, create an empty directory (eg ./build) and run:

perl -MInlineX::CPP2XS -e 
'InlineX::CPP2XS::cpp2xs("MIME::KDE","MIME::KDE","./build")'

That should give you a valid XS file (and a typemap, I think). It's then 
just a matter of creating a valid ./build/Makefile.PL and ./build/KDE.pm 
(and whatever other files you want in ./build- a test script for 'make test' 
to work with would be a good idea). Then cd to ./build and build as a normal 
perl extension with no Inline dependency.

InlineX::CPP2XS can also write a Makefile.PL and skeleton KDE.pm for you if 
you want (and this is what I would be doing if it were my choice):

perl -MInlineX::CPP2XS -e 
'InlineX::CPP2XS::cpp2xs("MIME::KDE","MIME::KDE","./build", 
{WRITE_MAKEFILE_PL => 1, WRITE_PM => 1, VERSION => "0.01"})'

(I wrote both InlineX::C2XS and InlineX::CPP2XS, but I don't use the CPP 
one. I *think* it will give good milage, but it hasn't had a lot of use 
....)

See how you get on.
Feel free to enquire further re any problems with any of that.

Oh ... I should add that I'm not an expert on any of this stuff (especially 
C++) .... my diagnosis of the problem might be lacking some insight .... and 
there may well be other simpler solutions, faik. I hope there's something 
here that helps.

Cheers,
Rob