Can somebody help me with exporting functions from a DLL? I am defining functions in C++ like
extern "C" __declspec(dllexport) void* __qtd_QObject_QObject_QObject(args)
After compiling a DLL with MINGW and producing a lib file for it with implib I am trying to use them from D.
In D I declare them as
extern (C) void* __qtd_QObject_QObject_QObject(args);
And then compile it and link it to the .lib file made by implib for that DLL, but optlink complains that symbol is undefined. I tried to use that Cfunction from C++ and it worked. What I can do?

On Fri, Feb 13, 2009 at 4:22 AM, Eldar Insafutdinov <e.insafutdinov@gmail.com> wrote:
> Can somebody help me with exporting functions from a DLL? I am defining functions in C++ like
> extern "C" __declspec(dllexport) void* __qtd_QObject_QObject_QObject(args)
> After compiling a DLL with MINGW and producing a lib file for it with implib I am trying to use them from D.
> In D I declare them as
> extern (C) void* __qtd_QObject_QObject_QObject(args);
> And then compile it and link it to the .lib file made by implib for that DLL, but optlink complains that symbol is undefined. I tried to use that Cfunction from C++ and it worked. What I can do?
>

What's the implib command you're using?  Often you need to use the /system flag.

--bb

Bill Baxter Wrote:

> On Fri, Feb 13, 2009 at 4:22 AM, Eldar Insafutdinov <e.insafutdinov@gmail.com> wrote:
> > Can somebody help me with exporting functions from a DLL? I am defining functions in C++ like
> > extern "C" __declspec(dllexport) void* __qtd_QObject_QObject_QObject(args)
> > After compiling a DLL with MINGW and producing a lib file for it with implib I am trying to use them from D.
> > In D I declare them as
> > extern (C) void* __qtd_QObject_QObject_QObject(args);
> > And then compile it and link it to the .lib file made by implib for that DLL, but optlink complains that symbol is undefined. I tried to use that Cfunction from C++ and it worked. What I can do?
> >
> 
> What's the implib command you're using?  Often you need to use the /system flag.
> 
> --bb

Thanks, that helped! I used it without any flags.

Bill Baxter Wrote:

> On Fri, Feb 13, 2009 at 4:22 AM, Eldar Insafutdinov <e.insafutdinov@gmail.com> wrote:
> > Can somebody help me with exporting functions from a DLL? I am defining functions in C++ like
> > extern "C" __declspec(dllexport) void* __qtd_QObject_QObject_QObject(args)
> > After compiling a DLL with MINGW and producing a lib file for it with implib I am trying to use them from D.
> > In D I declare them as
> > extern (C) void* __qtd_QObject_QObject_QObject(args);
> > And then compile it and link it to the .lib file made by implib for that DLL, but optlink complains that symbol is undefined. I tried to use that Cfunction from C++ and it worked. What I can do?
> >
> 
> What's the implib command you're using?  Often you need to use the /system flag.
> 
> --bb

okay, second problem then - I need to be able to call extern (C) functions defined in D code from DLL. I tried to do getProcAddress(NULL, "__some_D_func");
but this doesn't work.

On Fri, Feb 13, 2009 at 5:00 AM, Eldar Insafutdinov <e.insafutdinov@gmail.com> wrote:
> Bill Baxter Wrote:
>
>> On Fri, Feb 13, 2009 at 4:22 AM, Eldar Insafutdinov <e.insafutdinov@gmail.com> wrote:
>> > Can somebody help me with exporting functions from a DLL? I am defining functions in C++ like
>> > extern "C" __declspec(dllexport) void* __qtd_QObject_QObject_QObject(args)
>> > After compiling a DLL with MINGW and producing a lib file for it with implib I am trying to use them from D.
>> > In D I declare them as
>> > extern (C) void* __qtd_QObject_QObject_QObject(args);
>> > And then compile it and link it to the .lib file made by implib for that DLL, but optlink complains that symbol is undefined. I tried to use that Cfunction from C++ and it worked. What I can do?
>> >
>>
>> What's the implib command you're using?  Often you need to use the /system flag.
>>
>> --bb
>
> okay, second problem then - I need to be able to call extern (C) functions defined in D code from DLL. I tried to do getProcAddress(NULL, "__some_D_func");
> but this doesn't work.

I think you may have to write some code to explicitly register your D
functions with the DLL.
You could write a mini getDCodeProcAddress kind of thing in your D
code.  Then give a pointer to that function to the C code in the DLL
at startup.  Then C code uses getDCodeProcAddress from there.

Maybe there's an easier way, but that's what I'd try.

--bb

On Thu, 12 Feb 2009 22:22:41 +0300, Eldar Insafutdinov <e.insafutdinov@gmail.com> wrote:

> Can somebody help me with exporting functions from a DLL? I am defining functions in C++ like
> extern "C" __declspec(dllexport) void* __qtd_QObject_QObject_QObject(args)
> After compiling a DLL with MINGW and producing a lib file for it with implib I am trying to use them from D.
> In D I declare them as
> extern (C) void* __qtd_QObject_QObject_QObject(args);
> And then compile it and link it to the .lib file made by implib for that DLL, but optlink complains that symbol is undefined. I tried to use that Cfunction from C++ and it worked. What I can do?


I believe it should be extern extern(C) ...
Otherwise you /declare/ a function with C linkage but provide no implementation so that's why it fails at link time.