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simple vararg? problem
I'm trying to get an example working of vararg...
and in the process of doing so, i just wanted to do something simple and see which value is being added inside the loop, and for some reason instead of outputting '2' the first time through it tries to read at address 00000002... and im not sure what to do

yeah! I know im a newb.. i'm reading through the programmers guides, and this little problem seems to have me stumped.. any input would be great :)


.586
.model flat, stdcall
option casemap:none

include kernel32.inc
include windows.inc
include masm32.inc

includelib kernel32.lib
includelib masm32.lib

.data
StringData2 BYTE 255 DUP(0)
Prompt BYTE "Press enter to quit", 0

addfunc PROTO C, :BYTE, :VARARG

.code
start:
invoke addfunc, 5, 2, 2, 2, 2, 2
invoke StdOut, addr Prompt
invoke StdIn, addr StringData2, LENGTHOF StringData2
invoke ExitProcess, 0

addfunc PROC C, argCount:BYTE, argVal:VARARG
local StringData:DWORD
xor eax, eax
xor esi, esi

.while(argCount > 0)
mov eax, argVal
mov StringData, eax
inc esi
inc esi
inc esi
inc esi
invoke StdOut, StringData ;I want this to print out 2
;but it tries to read at address 2
dec argCount
.endw
Ret
addfunc EndP
end start

Thanks guys.. sorry for such a stupid question.... but it was either ask or yank my hair out :)
Posted on 2004-02-08 00:02:26 by dijo
simple vararg? problem
Simple mistake is the source of the problem. Use 'addr' to pass the string buffer.
Posted on 2004-02-08 00:27:34 by Starless
simple vararg? problem
well, I tried that too.. believe it or not, and I just tried it again right now :)

It just makes little ascii smiley faces on the screen instead of showing the number.. kind of weird, i guess..

any thoughts?

btw.. I saw parts of the bible black anime... nice :P
Posted on 2004-02-08 00:29:11 by dijo
simple vararg? problem
The problem is that you are passing the dword value "2" to StdOut. This is not BASIC, nor C++ with "cout<<". The function expects an address to a string, which has a value similar to "0410F30" . 


.586

.model flat, stdcall

option casemap:none

include \masm32\include\kernel32.inc

include \masm32\include\windows.inc

include \masm32\include\masm32.inc

includelib \masm32\lib\kernel32.lib

includelib \masm32\lib\masm32.lib

.data

	StringData2 BYTE 255 DUP(0)

	Prompt BYTE "Press enter to quit", 0

	

.code

addfunc PROC C argCount:BYTE, argVal:VARARG 

	local StringData[260]:byte

	lea esi,argVal

	

	.while argCount

		push esi

		invoke dwtoa,dword ptr[esi],addr StringData

		invoke StdOut, addr StringData

		pop esi

		add esi,4

		dec argCount 

	.endw

	ret

addfunc EndP



start:

	invoke addfunc, 5, 2, 2, 2, 2, 2

	invoke StdOut, addr Prompt

	invoke StdIn, addr StringData2, LENGTHOF StringData2

	invoke ExitProcess, 0

end start
Posted on 2004-02-08 07:15:44 by Ultrano
simple vararg? problem
haha. you are the man :)
Yeah.. im still in the terms of thinking in c/c++ but hopefully that'll change soon. thanks man
Posted on 2004-02-08 12:13:56 by dijo