Math.dll

[layer]

hey folks!!! i made my first Dll which can Divide, Multiply, Subtract, and Add! here ya go..

and heres the test thingy!:

$add= DllCall ("Math.dll", "int", "Add", "int", 1, "int", 2)
MsgBox (4096, "Testing", $add[0])
$multiply= DllCall ("Math.dll", "int", "Multiply", "int",  3, "int", 4)
MsgBox (4096, "Testing", $multiply[0])
$divide= DllCall ("Math.dll", "int", "Divide", "int", 10, "int", 2)
MsgBox (4096, "Testing", $divide[0])
$subtract= DllCall ("Math.dll", "int", "Subtract", "int", 14, "int", 7)
MsgBox (4096, "Testing", $subtract[0])

make sure the Math.dll is in the same dir as the script (i think, im not sure if there is a specific location..)

EDIT if ya want the source, just say so

Edited February 21, 2005 by layer

[Insolence]

I think we all want the source, shouldn't be too big to post.

How you got this to 25k is beyond me, though...

[layer]

idk, is that big or small? im not to familiar with whats big and whats not anyway, heres teh source,

DLL.H

#ifndef _DLL_H_
#define _DLL_H_

#if BUILDING_DLL
# define DLLIMPORT __declspec (dllexport)
#else /* Not BUILDING_DLL */
# define DLLIMPORT __declspec (dllimport)
#endif /* Not BUILDING_DLL */


class DLLIMPORT DllClass
{
  public:
    DllClass();
    virtual ~DllClass(void);

  private:

};


#endif /* _DLL_H_ */

DLLMAIN.CPP

expandcollapse popup

/* Replace "dll.h" with the name of your header */
#include "dll.h"
#include <windows.h>

DllClass::DllClass()
{

}


DllClass::~DllClass ()
{

}


BOOL APIENTRY DllMain (HINSTANCE hInst   /* Library instance handle. */ ,
                       DWORD reason     /* Reason this function is being called. */ ,
                       LPVOID reserved   /* Not used. */ )
{
    switch (reason)
    {
      case DLL_PROCESS_ATTACH:
        break;

      case DLL_PROCESS_DETACH:
        break;

      case DLL_THREAD_ATTACH:
        break;

      case DLL_THREAD_DETACH:
        break;
    }

    /* Returns TRUE on success, FALSE on failure */
    return TRUE;
}

extern "C"__declspec(dllexport) int Add (int a, int b)
{
       return(a + b);
}

extern "C"__declspec(dllexport) int Multiply (int a, int b)
{
       return(a * b);
}

extern "C"__declspec(dllexport) int Divide (int a, int b)
{
       return(a / b);
}

extern "C"__declspec(dllexport) int Subtract (int a, int b)
{
       return(a - b);
}

idk, i really dont know any functions in C++, but i know some operators, kind of sort of not really?

[Insolence]

Seems very big to me, look at Larry's tcp DLL. It's like 5 kB?

I made a simple MsgBox thing, 25 kB... we're including too much crap I think

EDIT:

I shaved of 12kB by excluding the header.

Simply this now:

#include <windows.h>
extern "C" __declspec(dllexport) int Hello();

int Hello(){
    MessageBox( NULL, "Hello world!", NULL, MB_OK ); 
    return 1;            
}

Edited February 22, 2005 by Insolence

[layer]

seems like excluding the header "dll.h" gives me a million errors hmmm... got too much on my mind to think right now...

EDIT: btw, neat dll you got there, i was trying to create a messagebox dll youve answered it, thanks

Edited February 22, 2005 by layer

[Insolence]

No problem

I don't see how you get errors. Make sure you stop trying to include it in the header, and you get rid of all the DLL events.

[Valik]

The blind leading the blind...

[Insolence]

Ouch Valik, ouch.

Maybe I could show you a thing or two about something? Do you know _everything_ about _everything_?

[DaveF]

The ~25K DLL size is probably coming from one of a couple of things, the first is that your DLLs are being built with debugging symbols inside. A debugger can use the symbols to show you what line the execution is at when you're debugging so you can check variable values, etc. Without the debug information your final binary will generally be manifold times smaller, but you'll only see assembly code when you go to debug it.

Another factor may be including the windows.h header file. If you try to use a function in C++ that's not in the same module (C++ file) that you're working in, the compiler will throw an error because it doesn't know WTF you're talking about. Header files are used as a place to put a declaration of a function that just has the name and how many and what kind of parameters it takes; by including a header you're telling the compiler "Chill, take for granted that there's a function with this name that's blueprinted elsewhere, I'll give you a file or library for it at link time."

Having said that, windows.h has got, you guessed it, declarations (actually it itself #includes other files) for every effing thing that someone thought that you might need for programming for MS Windows. So, even though you just want a function like MessageBox() you're also getting the declarations for printing, NT services, OLE, etc. functionality that you care not a whit about...

Depending on the pre-defined function that you're using, you can sometimes find the header file that contains its actual declaration and just include that rather than the entire mess, but headers include other headers for things that they require, so it can get tedious whittling down to just the things you need...

Generally a DLL will have a number of functions inside so that the final, optimized size is big enough that 20K or so in size isn't that much difference.

[Insolence]

Thanks Dave...

I didn't know once you included something like windows.h, it included a bunch of other crap.

[layer]

well, you know what, i dont care if the blind leads the blind cause im learning a lot more out of what Insolence told me and DaveF rather then someone just saying oh here, put this in your IDE and compile it.. and DaveF ill take that into consoderation thanks a bunch and LazyCat has sent me some info too, which im going to check out in a bit

[Valik]

DaveF, what you don't mention, though, is that in a Release build, any even remotely half-decent compiler will optimize out unused stuff so its a waste of time figuring out the exact header. The real size in that DLL is from all the useless CRT startup code around the entry point.

I don't see how you get errors. Make sure you stop trying to include it in the header, and you get rid of all the DLL events.

So you don't see that ignorning the header will cause an error when the compiler finds the definition for a class constructor/destructor but no declaration? The class doesn't even need to be there, it's leftover wizard generated code. And the events in DllMain() are trivial as they are just #define's so they can stay or go, doesn't really matter. The part that needs to go is the entire DllMain(), but just deleting it won't make it go away as the compiler will generate a DllMain() for you.

[layer]

well, i have to owe it all to lazycat! while you guys were chattering back and forth LazyCat was helping me with this size problem, now it's only 11.5KB all with the keystroke of "-s"... thanks LazyCat!

heres the new Dll

[Valik]

11.5? Thats nice but with a little tweaking, I can get 2,560 bytes before UPX...

Suggestions: Worry about how code works, not how to reduce size, or if you're going to worry about reduced size, learn all the compiler/linker tricks.

[layer]

yea, thanks for the advice i wasnt really interested in how big the Dll size was as you can see above (Is 25K big? ) as long as it gets the job done, i cant complain... besides, i still have 3 quarters left on my hard drive and i used to have 1 quarter, i just deleted a whole bucn of stuff i didnt need.. thanks!

[Insolence]

So you don't see that ignorning the header will cause an error when the compiler finds the definition for a class constructor/destructor but no declaration?  The class doesn't even need to be there, it's leftover wizard generated code.  And the events in DllMain() are trivial as they are just #define's so they can stay or go, doesn't really matter.  The part that needs to go is the entire DllMain(), but just deleting it won't make it go away as the compiler will generate a DllMain() for you.

<{POST_SNAPBACK}>

I don't get it?

This is my code, I got rid of the header and everything generated by Dev C++:

#include <windows.h>
extern "C" __declspec(dllexport) int Hello();

int Hello(){
    MessageBox( NULL, "Hello world!", NULL, MB_OK ); 
    return 1;            
}

Was that all addressed to me?