(C++) Prototype class from foreign DLL

[VXP]

My specific help request is this:

I have a certain DLL file which I've loaded with LoadLibrary, and it works fine.

I can call a function CalcLpqCheckSum just fine, parameters are CalcLpqCheckSum(void*, int)

However, other functions all appear to be classes:

[IMG]kingofkings4.000webhostapp.com/ida_mpgh_q.png[/IMG]

I can reference them just fine in my code but when I call the function my application freezes and crashes.
Depending on what I do, I get various 32bit return values.

[IMG]kingofkings4.000webhostapp.com/ida_mpgh_q2.png[/IMG]

How do I properly create a prototype of a class from a foreign DLL in my program?

Also, can anyone tell me what is going on in the first picture? I lack the understanding of how these functions are designed and how to prototype them.

Even if I prototype directly from a function address I still can't call the LpqSystem function with or without parameters. It crashes regardless.

[ElonTusk]

My specific help request is this:

I have a certain DLL file which I've loaded with LoadLibrary, and it works fine.

I can call a function CalcLpqCheckSum just fine, parameters are CalcLpqCheckSum(void*, int)

However, other functions all appear to be classes:

[IMG]kingofkings4.000webhostapp.com/ida_mpgh_q.png[/IMG]

I can reference them just fine in my code but when I call the function my application freezes and crashes.
Depending on what I do, I get various 32bit return values.

[IMG]kingofkings4.000webhostapp.com/ida_mpgh_q2.png[/IMG]

How do I properly create a prototype of a class from a foreign DLL in my program?

Also, can anyone tell me what is going on in the first picture? I lack the understanding of how these functions are designed and how to prototype them.

Even if I prototype directly from a function address I still can't call the LpqSystem function with or without parameters. It crashes regardless.

I am a bit confused as to what you're doing. If I understand your post correctly, you have some DLL file, and you are unpacking that file using some library called "LoadLibrary", and then you would like to construct the protoype for a specific class? What exactly are you trying to do? Maybe explain the bigger picture, so that way it will easier for others to chime in and help.

[Azuki]

-snip-

If you say the parameters are a void pointer and an int, why do you call it like LpqSystem(void*)?
The void* is also certain the this pointer, so the current object.

Attach the debugger to CalcLpqCheckSum and check out what variables are passed to LpqSystem, if the void* parameter is the pointer to the current object then that's great and you don't have to call the function with that parameter.

[VXP]

Attach the debugger to CalcLpqCheckSum and check out what variables are passed to LpqSystem, if the void* parameter is the pointer to the current object then that's great and you don't have to call the function with that parameter.

So if I called LpqSystem(this*); it should work?
Sorry for asking I just don't have the time at the moment to mess around, I'll come back to this.