SWIG: Wrapping C++ for Perl using only a header and a shared library, can't locate loadable object error

Question

I\'m trying to learn SWIG and I\'m having some issues getting SWIG to work with perl on a Linux machine. I have the files Dog.h, Crow.h, Animal.i, and libmylib.so. All these

Answer 1

The following seems to work on Ubuntu 16.04:

Files:

Animal.i:

%module Animal
%{
#include "Dog.h"
#include "Crow.h"
%}
%include "Dog.h"
%include "Crow.h"

Crow.h

class Crow {
public:
    Crow()  {
        ncrows++;
    }
    virtual ~Crow() {
        ncrows--;
    }
    static  int ncrows;
};

Dog.h:

class Dog {
public:
    Dog()  {
        ndogs++;
    }
    virtual ~Dog() {
        ndogs--;
    }
    static  int ndogs;
};

Crow.cpp:

#include "Crow.h"
int Crow::ncrows = 0;

Dog.cpp:

#include "Dog.h"
int Dog::ndogs = 0;

test.pl:

use strict;
use warnings;
use Animal;

print "Creating a Crow:\n";
my $c = Animal::Crow->new();
print "    Created crow $c\n";
$c->DESTROY();
print "Creating a Dog:\n";
my $d = Animal::Dog->new();
print "    Created dog $d\n";
$d->DESTROY();

Compilation:

swig -perl -c++ Animal.i
g++ -fPIC -c Crow.cpp
g++ -fPIC -c Dog.cpp
g++ -shared Crow.o Dog.o -o libmylib.so
g++ -fPIC -c Animal_wrap.cxx -I/usr/lib/x86_64-linux-gnu/perl/5.22/CORE
g++ -shared -L. Animal_wrap.o -lmylib -o Animal.so

Running test script:

$ LD_LIBRARY_PATH=. perl test.pl 
Creating a Crow:
    Created crow Animal::Crow=HASH(0x10c2eb0)
Creating a Dog:
    Created dog Animal::Dog=HASH(0x10c2f88)