Allocating memory in D shared library when accessed from C++

[Martin Drasar]

Hello everyone,

I would like to ask you about linking D shared objects (.dll and .so) 
from a C++ program.

Say I have this C++ loader:

typedef int (*MagicFunction) ();

HMODULE handle = LoadLibraryA("DLibrary.dll");
if (handle)
{
  MagicFunction fn = (MagicFunction) GetProcAddress(handle, "_magicFunction");
  std::cout<<fn()<<std::endl;
}

and this D library:

class Something {}

export extern (C) int magicNumber()
{
  Something desc = new Something();
  return 9;
}

extern (Windows)
BOOL DllMain(HINSTANCE hInstance, ULONG ulReason, LPVOID pvReserved)
{
    final switch (ulReason)
    {
        case DLL_PROCESS_ATTACH:
            g_hInst = hInstance;
            dll_process_attach( hInstance, true );
            break;

        case DLL_PROCESS_DETACH:
            dll_process_detach( hInstance, true );
            break;

        case DLL_THREAD_ATTACH:
            dll_thread_attach( true, true );
            break;

        case DLL_THREAD_DETACH:
            dll_thread_detach( true, true );
            break;
    }
    return true;
}

then whenever the code reaches the call:
Something desc = new Something();
I get 'Access violation reading location 0x...'

I thought that the GC is angry with me, so I have tried to use malloc, 
but to no avail. Error is the same...

Can you please give me a hint what I am doing wrong? Also I am curious 
why is the first name of exported function underscored and all the 
others are not.

Thanks for your time.

Martin