ASM Community

Since I often see a thread where someone asks about using esp, removing the leave instruction, no stack-frames, no-locals etc. I present the no stack-frame, no locals, no proc MsgProc!!

MsgProc:

	

	mov eax, [esp+8]   ;uMsg



	.IF eax==WM_DESTROY

		invoke PostQuitMessage,NULL

	.ELSE



	mov edi, [esp]				;save esp top contents from being trashed.They will be trashed

	add esp,4 ;	mov esp, esi                ;advance esp to address of hWnd

	call DefWindowProc	

		sub esp,20			;fix esp, 16 for parms, 4 for advance

		mov [esp],edi		;restore trashed esp top contents

		ret			;jumps somewhere, probably kernerl32, but hey, it works...

 	.ENDIF



	xor eax,eax					;dont think we ever get here

	ret 

Since the parameters where already on the stack, I just set esp to the right place before the call. Reused stack space.

I don't advocate programming this way. I did it just to see if I could.

Discuss amongst yourselves...

If you want a shorter one:

For Frame-Based Procedure:

pop ebp
jmp DefWindowProc

For Non-Frame-Based Procedure:

jmp DefWindowProc

:grin:

bAZiK,

The only lib I had included was kernel32. The ret whent to an address like 77de****, so I'd say kernel32.

I have been spending alot of time lately trying to figure out a coding style that fits how I think. I think it is PROCless.

No more prototypes, no more inc file of prototypes. Easy use of public and extern. Now I set up my proc like this:

...all the lib includes, .686 etc.



public (procname)

public (procdata)



.data

(procdata) label dword



data1 dword 0

data2 dword 0



.code

(procname) dd offset @(procname);pointer for indirect call to proc

@(procname):

	pop esi

	

....do stuff here  



	jmp esi

end



Prototype to make calls work:

LCALL			TYPEDEF proto;label call

PLCALL			TYPEDEF PTR LCALL



extern (procname):proc

extern (procdata):dword   ;public and extern are now easy!!



call PLCALL (procname)

I spent alot of effort to find a way that would give me informative diassembly when debugging.

My PLCALL will dissassemble to:

call [_procname(0000000)]

not call ($$$0001)

Declaring (procdata) pubilc, makes all data below public with just one extern. In an alternate file, I will still get real names.

mov eax, data1

will stay the same not

mov eax, procname+4

THe above was just a quick(first draft) test with something I didn't write.

Sorry, dont have time to type nicely right now:

------------------------------------------------------------------------

...all the lib includes, .686 etc.



public fooproc

public foodata



.data

foodata label dword

data1 dword 0

data2 dword 0



.code

fooproc dd offset @fooproc    ;pointer for indirect call to proc

@fooproc:

	pop esi

	

....do stuff here  



	jmp esi

end

-----------------------------------------------------------------------------

In another file:



extern fooproc:proc

extern foodata:dword   ;public and extern are now easy!!



.code

call PLCALL fooproc

-----------------------------------------------------------------------------

Prototype to make calls work:

LCALL			TYPEDEF proto           ;label call

PLCALL			TYPEDEF PTR LCALL

Hope this is a little easier to read.