How to use a windows dll in linux

[Mark Smith]

I know this question has been asked many times, but I cannot find enough 
information to solve the problem.

I have a windows dll and header files. I want to make a library that I 
can link to and use on linux. What are the steps required to do this?

I have used winedump to generate a .spec file and winebuild to generate 
an assembly file. What comes next?

Thanks

[Dan Kegel]

On 8/30/06, Mark Smith  wrote:
> I know this question has been asked many times, but I cannot find enough
> information to solve the problem.
>
> I have a windows dll and header files. I want to make a library that I
> can link to and use on linux. What are the steps required to do this?

Sorry, you can't.   Not at the moment, anyway.  That's on the to-do list.
- Dan

[Jeremy White]

Dan Kegel wrote:
> On 8/30/06, Mark Smith  wrote:
> > I know this question has been asked many times, but I cannot find enough
> > information to solve the problem.
> >
> > I have a windows dll and header files. I want to make a library that I
> > can link to and use on linux. What are the steps required to do this?
>
> Sorry, you can't.   Not at the moment, anyway.  That's on the to-do list.

It's not that black and white, is it?

I believe you can, and it actually works reasonably well.  BUT there's
a big catch - you have to make your program into a Winelib application.

That is, what you (reasonably) want is just a simple foo.so you can
dlopen and then do invoke_my_windows_function().

You can get that, but what you have to do is rename your main
to be linux_main, and then write a whole new WinMain which invokes
your linux_main.

Then, from within your linux app, you can write some glue to
make the connectiong.

You can get into trouble if you depend heavily on particular
IPC mechanisms, threading in particular, but I believe that
basic usages should still work.

So, basically, if you're willing to stand your application on
its head, you can get the functionality you want.

Most people don't get over that; to be frank, I think those
that don't are largely just stuck on the 'smell' of it;
from a practical standpoint, I think it works fine.

Cheers,

Jeremy

[Troy Rollo]

On Friday 01 September 2006 03:52, Jeremy White wrote:
> Dan Kegel wrote:
> > On 8/30/06, Mark Smith  wrote:
> > > I have a windows dll and header files. I want to make a library that I
> > > can link to and use on linux. What are the steps required to do this?
> >
> > Sorry, you can't.   Not at the moment, anyway.  That's on the to-do list.
>
> It's not that black and white, is it?
>
> I believe you can, and it actually works reasonably well.  BUT there's
> a big catch - you have to make your program into a Winelib application.

Actually there's probably an easier way - a scheme I've been considering is 
one involving a crt0.o designed to load Wine (essentially making the native 
executable an equivalent of wine-pthread with other stuff), then start a 
Winelib program whose entry point calls back into a second entry point in the 
original executable. This scheme ought to work without any modifications to 
the core of Wine. We also wouldn't need to be reserving any memory areas, so 
the trimmed down operating system entry point of the Wine executable might be 
something like this:

int __wine_startup( int argc, char **argv, char **envp)
{
    char error[1024];
    char winelib_argv[3];
    char wine_entry_addr[sizeof(void *) * 2 + 1];

__wine_argc = argc;
    __wine_argv = argv;
    __wine_envp = envp;

wine_pthread_set_functions( &pthread_functions, 
sizeof(pthread_functions) );

sprintf(wine_entry_addr, "%p", __wine_entry);
    winelib_argv[0] = "execallback.exe.so";
    winelib_argv[1] 0;

wine_init( 2, winelib_argv, error, sizeof(error) );
    fprintf( stderr, "wine: failed to initialize: %s\n", error );
    exit(1);
}

A routine "__wine_exe_entry_point" would be exported by the executable. The 
startup code for "excallback.exe.so" would call that routine as substantially 
all of its initialisation code, so that the executable calls 
wine_dll_register providing its own details.

I suspect the "difficulty" associated with having a Linux executable that 
calls Windows DLLs using Wine has been due the assumption that "main()" in 
the executable would be executed before Wine - by throwing out this 
assumption the problem may be a whole lot easier to solve.