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