Shared libraries/DLLs

[Unknown W. Brackets]

Okay.

Example "plugin" example.d:

---
module example;

extern (C)
export int foo();

version (Windows)
	import utils.windows;

extern (C)
export int example()
{
	return 42 + foo();
}
---

Compiled with:

$(DMD) $(DFLAGS_DEBUG) -op -of$(OUTPUT) $(LIBS) $(wildcard utils/*.d) 
example.d example.def

Or:

$(GDMD) $(DFLAGS_DEBUG) -op -of$(OUTPUT) $(LIBS) $(wildcard utils/*.d) 
example.d -fPIC -q,-rdynamic,-shared


Plugin linker definition file:

---
LIBRARY         example.dll
DESCRIPTION     'Example'

EXETYPE         NT
SUBSYSTEM       WINDOWS 4.0
CODE            PRELOAD SHARED DISCARDABLE
DATA            PRELOAD SINGLE

EXPORTS
				example
---


Example host program for Windows, load_test.d:

---
module load_test;

import std.c.windows.windows;
import std.string, std.stdio;

extern (C)
	alias int function() example_f;

int main()
{
	HMODULE m = cast(HMODULE) LoadLibraryA(toStringz("example.dll"));

	example_f f = cast(example_f) GetProcAddress(m, toStringz("example"));

	if (f)
		writefln("%d", f());

	FreeLibrary(m);

	return 0;
}

extern (C)
export int foo()
{
	return 43;
}
---


Quick DllMain file from samples, utils/windows.d:

---
module utils.windows;

version (Windows):

import std.c.windows.windows;

extern (C)
{
	void gc_init();
	void gc_term();
	void _minit();
	void _moduleCtor();
	void _moduleUnitTests();

	HINSTANCE g_hInst;
}

extern (Windows)
BOOL DllMain(HINSTANCE hInstance, ULONG ulReason, LPVOID pvReserved)
{
     switch (ulReason)
     {
	case DLL_PROCESS_ATTACH:
	    gc_init();			// initialize GC
	    _minit();			// initialize module list
	    _moduleCtor();		// run module constructors
	    _moduleUnitTests();		// run module unit tests
	    break;

	case DLL_PROCESS_DETACH:
	    gc_term();			// shut down GC
	    break;

	case DLL_THREAD_ATTACH:
	case DLL_THREAD_DETACH:
	default:
	    // Multiple threads not supported yet
	    return false;
     }

     g_hInst = hInstance;
     return true;
}
---

I don't have the Linux loader in front of me but it's almost exactly the 
same and works just fine (LoadLibraryA => dlopen, GetProcAddress => 
dlsym, FreeLibrary => dlclose, with some dlerror logic in there.)  But 
as stated, it appears that there's really no "reverse linking" of DLLs.

-[Unknown]


Jarrett Billingsley wrote:
> "Unknown W. Brackets" <unknown at simplemachines.org> wrote in message 
> news:fnvd2q$229m$1 at digitalmars.com...
>> Well, the def being for the library, not for the program loading the 
>> library.  Otherwise I don't get exports named properly, etc.
> 
> In that case, I'd be more interested to see how you're compiling all this 
> code.  The code itself looks very simplistic, and I don't see any apparent 
> failure points. 
> 
>