Dont want to use MASM macro

[alpha1]

Hello,

Now I'm creating some DLL with masm32. The problem is that I can't create desirable function without mas32 macro. Everything is ok when I use:

DLLFunc proto :DWORD
public DLLFunc

....

DLLFunc proc EXPORT param:DWORD
...
DLLFunc endp

So how can I do it without param and proto? I need to create function with one dword parameter, but i need it to do without macros. If I create function without proto and param I get _DLLFunc@0 in library, but I need _DLLFunc@4. How to do this?
Thanks in advance

alpha

[Vortex]

Hi alpha1,

Welcome to the forum.

Did you create a module definition file for your DLL?

You can check Iczelion's Win32asm tutorial #17 about DLLs

[alpha1]

Hi alpha1,

Welcome to the forum.

Did you create a module definition file for your DLL?

You can check Iczelion's Win32asm tutorial #17 about DLLs

Yes, I have create module definition file and I have read Iczelion tutorial, but still I don't understand how to do the same without macros of masm32. By the way, in the example function takes no parameters. My function is with one parameter - DWORD.

alpha

[hutch--]

Alpha,

The format of a DLL is very straight forward, create  the LibMain or DLLmain entry point and then create any other procedure you like to export. There is a tutorial on the forum web site that will help you write what you are after.

[alpha1]

Hello,

Ok I think you don't understand my question becouse of my poor english. I'll try...
So lets look at entrypoint function:

LibMain proc parameter1:DWORD, parameter2:DWORD, parameter3:DWORD

    mov eax, TRUE
    ret

LibMain endp

The simple question: how to do the same without parameter1:DWORD, parameter2:DWORD.... how to tell masm that this function has 3 parameters without using parameter:DWORD macro? How to do it in old way?

alpha

[thomasantony]

Maybe you can do it like this. I am not sure if it will work. You also can't use invoke.

Code Select Expand


LibMain:
push ebp
mov ebp,esp

mov eax,1
leave
ret 12      ; pop off 3 dword args from stack b4 returning (4*3 = 12)

You can access the params at [ebp-08h],[ebp-0Ch],[ebp-10h] etc. But why do so, when you can do it using proc?

Thomas Antony

[hutch--]

Alpha,

the problem is the spec for a DLL entry point require 3 x 4 byte parameters on the stack and if it varies from that, it may not run correctly. I have yet to see the point unless its some trivial byte saving example but if you want a DLL to run reliable you must kep that in mind.

You can try something like,


LibMain:
  mov eax, 1
  ret 12

[alpha1]

You can access the params at [ebp-08h],[ebp-0Ch],[ebp-10h] etc. But why do so, when you can do it using proc?

:))) Still not good question. Try again:
If I use
Myfunc proc param1:DWORD
...
Myfunc endp

then masm will generate:

push ebp
mov ebp,esp
....
leave
ret 4

and export function will be _Myfunc@4

Now I want to write myself:

Myfunc proc
push ebp
mov ebp, esp
...
leave
ret 4

Now as you can see I do not use any macros, but my export function in dll is _Myfunc@0 but not @4 becouse masm do not know how many parameters there are in the function. How to tell masm about parameters not using param:DWORD???????
Thanks in advance and thanks for patience :)

alpha

[Vortex]

Try this one:

Code Select Expand


Myfunc@4 proc
push ebp
mov ebp, esp
...


[alpha1]

Try this one:

Code Select Expand


Myfunc@4 proc
push ebp
mov ebp, esp
...


Already tried. Then function in dll is _myfunc@4@0 :( thats why i'm asking :/

alpha

[hutch--]

Alpha,

Perhaps I dids not connect the problem you are creating with what you are after. A DLL entry point is defined by the OS so you get it right or it does not work. What I suggested to you was to,


    1. Return non zero in EAX so the DLL will run.
    2. Use the RET 12 to balance the stack


You have still not made sense of what you are trying to do and why you are trying it.

[alpha1]

You have still not made sense of what you are trying to do and why you are trying it.

Never mind... It's too hard for me to explain in english. I tried to explain it with asm code, but I didn't suceed. Thanks anyway

alpha

[Rain Dog]

It sounds to me like he wants to get the correct name mangling of his function.


If he uses a macro, MASM correctly interprets his function as taking said parameters and generates a manged name with @4, at the end.

If he does not use the masm macro, the linker does not correctly mangle his procedures name.

He does not have any questions as to how to create a procedure or a DLL, he simply wonders why the linker mangles his name differently for seemingly exact code.


Linkers use name mangling as we should all know to differentiate between overloaded functions. Thus, in your c program, the functions:

void myFunc(int)

is name mangled to be something different than

void myFunc(float)


Apparently, the linker is not recognizing his code as taking the correct number of parameters.



I would take a stab in the dark and guess that the proc macro also defines a function prototype, therefore allowing the linker to correctly identify the number of parameters that it takes.


So maybe that is a suggestion, declare the prototype of your function with PROTO

[Vortex]

alpha1,

If I understood correctly the situation, this might help you:

DLL source code:

Code Select Expand


    .386
    .model flat, stdcall
    option casemap :none

include \masm32\include\windows.inc
include \masm32\include\kernel32.inc
include \masm32\include\user32.inc

includelib \masm32\lib\kernel32.lib
includelib \masm32\lib\user32.lib

    public StdOut@4

    .code

DllEntry:
    mov  eax,TRUE
    ret 12

StdOut@4: ;StdOut function from masm32.lib
    push ebp
    mov ebp,esp
    add esp,-12    ;3 dwords
;   LOCAL hOutPut  :DWORD
;   LOCAL bWritten :DWORD
;   LOCAL sl       :DWORD

    invoke GetStdHandle,STD_OUTPUT_HANDLE
    mov [ebp-4], eax ; hOutPut

    invoke lstrlen,[ebp+8] ; lpszText
    mov [ebp-12], eax

    lea eax,[ebp-8] ; bWritten
    invoke WriteFile,[ebp-4],[ebp+8],[ebp-12],eax,NULL ; [ebp-12] = sl
    mov eax,[ebp-8]
    leave
    ret 4

END DllEntry


Sample code using this DLL:

Code Select Expand


.386
.model flat,stdcall
option casemap:none
include \masm32\include\windows.inc
include \masm32\include\kernel32.inc
includelib Console.lib
includelib \masm32\lib\kernel32.lib

StdOut PROTO :DWORD

.data
msg db 'Hello my friend!',0

.code

start:
invoke StdOut,ADDR msg
invoke ExitProcess,0

END start


You can check the attachment to see how to build the DLL and the sample code.

[attachment deleted by admin]

[alpha1]

You can check the attachment to see how to build the DLL and the sample code.

Finally two last posters seems to understood my question. I'm sorry for my english again :)
So the last example has worked just fine for me, but before that I have discovered, that I have problems when I use:
.model 386p, stdcall    but everything is ok when I use
.model 386p

Now I'm lost completely. You use .model 386p, stdcall in your example and program works just fine?? The only difference is thatr I'm using .model without stdcall key, I do not use casemap option and I use:

myfunc proc:

myfunc endp

you use only myfunc:
So I just don't see the difference. I'll try to look more deeply. Thanks for your answers !

alpha