From what I read on newsgroups, this should be possible with gdc on linux?  Goal is a plugin type solution.  With the following code, I compile intf.d and lib.d together into a shared library, and intf.d and main.d into an executable.  Compiles/links fine.  When I run it, I get a message like:

Null library handle: libxyz.so.1.0.1: undefined symbol: __data_start

I compiled the .d files with -fPIC and the .so with:
gcc -shared -Wl,-soname,libxyz.so.1 -fPIC.

Is this definitely possible, and if so, what am I doing wrong?  I tried gdc 0.24 and the latest off svn with the same results.

TIA.

-------------------------------------------------------------

intf.d:
=========
module intf;
public interface I { public int getId(); }

lib.d:
=========
module lib;
import intf;
class A : I { public int getId() { return 42; } }
extern (C) { I getObj() { return new A(); } }

main.d:
==========
...
void main(char[][] args)
{
    void* hnd = dlopen(toStringz("libxyz.so.1.0.1"), RTLD_NOW);
    if (hnd == null) {
        printf("Null library handle: %s\n", dlerror());
        return 0;
    }
    ...
}

BB wrote:
>  From what I read on newsgroups, this should be possible with gdc on linux?  Goal is a plugin type solution.  With the following code, I compile intf.d and lib.d together into a shared library, and intf.d and main.d into an executable.  Compiles/links fine.  When I run it, I get a message like:
> 
> Null library handle: libxyz.so.1.0.1: undefined symbol: __data_start
> 
> I compiled the .d files with -fPIC and the .so with:
> gcc -shared -Wl,-soname,libxyz.so.1 -fPIC.
> 
> Is this definitely possible, and if so, what am I doing wrong?  I tried gdc 0.24 and the latest off svn with the same results.
> 
> TIA.
> 
> -------------------------------------------------------------
> 
> intf.d:
> =========
> module intf;
> public interface I { public int getId(); }
> 
> lib.d:
> =========
> module lib;
> import intf;
> class A : I { public int getId() { return 42; } }
> extern (C) { I getObj() { return new A(); } }
> 
> main.d:
> ==========
> ...
> void main(char[][] args)
> {
>     void* hnd = dlopen(toStringz("libxyz.so.1.0.1"), RTLD_NOW);
>     if (hnd == null) {
>         printf("Null library handle: %s\n", dlerror());
>         return 0;
>     }
>     ...
> }
> 
> 
> 

Check the rebuild configuration for GDC, it has all the flags and such necessary to both create and host .so's. Note that creating .so's is not all that well supported though.

http://svn.dsource.org/projects/dsss/trunk/rebuild/rebuild.conf/gdc-posix

 - Gregor Richards