A (quite) simple ASM compiling question!

[Jop]

Hiya peeps...
Still working on a prog with kedaman (see our Icon question in the General Forums)...

We're currently working on the plugin-mechanism. We'll call Unmanaged (yes that's a .NET term, the core is written in C#) Dll.

The thing is, we're loading the DLL at runtime, and we ran into some problems calling the function... I looked up some stuff on the internet, and came accros this article that describes exactely our problem ( http://www.codeproject.com/csharp/dyninvok.asp )

As you can see, it uses some assembly code to fix the problem of the dynamicly calling of the function... yes, the guy included the source code, but didn't shipped a compiled version of the DLL, only the ASM code and a makefile (+ some test C# code which is inrelevant to the question)...

When I try to compile the code using Visual Studio.NET, I get some compiling errors (something about a namespace and stuff)...

Now could someone please tell me what the problem is with the code, or compile it for me and send the compiled version?

Here's the ASM code I try to compile:

; -------------------------------------------------------------
;
; InvokeFuncAsm - Invokes a function through a function pointer passed as
; the first argument. All other parameters are forwarded on, plus the return
; value of the function invoked is returned.
;
; Copyright (c) Richard Birkby, ThunderMain ltd, November 2001
;
; -------------------------------------------------------------
 
.386
.model flat
 
option prologue:none
option epilogue:none
option dotname
 
 
.code
align DWORD
DllMain     proc    stdcall public, instance:DWORD, reason:DWORD, reserved:DWORD
        mov     eax, 1  ; success
        ret 12
DllMain     endp
 
 
align DWORD
InvokeFunc  proc    stdcall public, funcptr:DWORD
 
    pop ecx ; save return address
    pop edx ; Get function pointer
    push    ecx ; Restore return address
    jmp edx ; Transfer control to the function pointer
InvokeFunc  endp
 
end

Thanks for your Help!

[Zaei]

YOu can do this in MSVC^, so it should work in MSVC.NET:

__declspec(naked) InvokeProc(void* func) {
    __asm {
        pop	ecx	
        pop	edx	
        push	 ecx	
        jmp	edx
    }
}

That should do it. The __declspec(naked) attribute removes the prolog and epilog code from the function, leaving only the asm block, which is what your pure asm function does anyway.

Z.

[Jop]

Wow thanks alot for the quick reply, I'll try it soon..
thanks alot man!

[Jop]

I managed to compile the DLL from pure ASM, someone at another forum pointed out how to use the NMAKE command from the Visual Studio Command Prompt... so there's a sweet 2,5 KB dll now

But thanks alot for your reply!

[Zaei]

Try mine anyway... I want to know if it would work =).

Z.

[Jop]

Well I did, but when I tried to use it in C# it said something about that it couldn't find the entry point for that function (eventhough I made a .def file with the appropriate stuff in it)

Thanks for the suggestion though!

[Zaei]

Oh well =).

Z.