Mozilla uses C DLL with js-ctypes

I am linking to create a dll and then using it with a Firefox extension.

I managed to create a DLL using gcc under Windows:

#include<stdio.h>
int add(int a,int b)
{
    return(a+b);
}

      

        
        
        
      

    

I am trying to use it through my DLL. After reading some posts, especially this one, I was not able to get this working: Binary component link to js-ctypes

Every time I try ctypes.open, I get an error: Could not load library . However, the path to the DLL is correct. Here is the JS code:

Components.utils.import("resource://gre/modules/ctypes.jsm");

AddonManager.getAddonByID("greenfox@octo.com", function(addon)
{
    var libcPath = addon.getResourceURI("components/library.dll");

    if (libcPath instanceof Components.interfaces.nsIURI)
    {
        var libc = ctypes.open(libcPath.path);

        var libc = ctypes.open(libc);

        /* import a function */
        var puts = libc.declare("add", /* function name */
                   ctypes.default_abi, /* call ABI */
                   ctypes.int32_t, /* return type */
                   ctypes.int32_t, /* argument type */
                   ctypes.int32_t /* argument type */
          );

          var ret = puts(1,2);

          alert("1+2="+ret);

    }

      

        
        
        
      

    

Do you have any ideas?