a problem with "common" directive

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vbVeryBeginner

Joined: 15 Aug 2004
Posts: 884
Location: \\world\asia\malaysia

vbVeryBeginner 26 Dec 2004, 04:48

hi, i am starting to learn some basic fasm macroinstruction and met with one problem

Code:

macro m_message [param1] {
        common
      mov eax,param1
      forward
     mov eax,param1
}
m_message 0x11111,0x22222,0x33333

and resulted the following output

Code:

flat assembler  version 1.56
macro.txt [52]:
m_message 0x11111,0x22222,0x33333
macro.txt [48] m_message [2]:
        mov eax,param1
error: extra characters on line.

and i really wonder WHY?
coz i guess it should be assembled and the result should be four mov eax,param1?
with the common eax value "0x11111"

Code:

macro m_message [param1] {
 common
      mov eax,param1
      forward
     mov eax,param1
}
m_message 0x11111

this could be assembled without problem, so does this mean, parameter is limitted to one
when we want to use it inside common directive?

thanks.

26 Dec 2004, 04:48

zjlcc

Joined: 23 Jul 2003
Posts: 32
Location: china

zjlcc 26 Dec 2004, 07:27

Code:

include '%fasminc%\win32ax.inc' 
.code
start:
macro m_message [param1] { 
;        common 
;        mov eax,param1 
        forward 
        mov eax,param1 
} 
m_message 11111h,22222h,33333h 

invoke ExitProcess,0
.end start

Code:

00401000 >/$  B8 11110100   MOV     EAX,11111
00401005  |.  B8 22220200   MOV     EAX,22222
0040100A  |.  B8 33330300   MOV     EAX,33333
0040100F  |.  6A 00         PUSH    0                                ; /ExitCode = 0
00401011  \.  FF15 35204000 CALL    [402035]                         ; \ExitProcess

26 Dec 2004, 07:27

vbVeryBeginner

Joined: 15 Aug 2004
Posts: 884
Location: \\world\asia\malaysia

vbVeryBeginner 26 Dec 2004, 13:13

well zjlcc, did u try to understand the problem?

Code:

macro m_message [param1] {  
;        common  
;        mov eax,param1  
;        forward                ;<- don't need to write this too coz it is default directive
        mov eax,param1  
}

26 Dec 2004, 13:13

vid
Verbosity in development

Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia

vid 26 Dec 2004, 14:55

vb: when you use group argument in common section, then it is replaced by all arguments:

Code:

macro def [a]
{
common
 db a
}
def 1,2,3,4

gets assembled to

Code:

db 1,2,3,4

check my preprocessor tutorial

26 Dec 2004, 14:55

vbVeryBeginner

Joined: 15 Aug 2004
Posts: 884
Location: \\world\asia\malaysia

vbVeryBeginner 26 Dec 2004, 20:03

hi vid, i don't know if i get u correctly,

Code:

macro m_message [param1] { 
        common 
        mov eax,param1 
} 
m_message 0x11,0x22,0x33

does this mean, this can't be assembled is because of the "comma (,)" coz when processed it would be translated into
mov eax,0x11,0x22,0x33?

so, unless we have a macro that let mov support the "comma (,)" for more parameters.

Code:

macro mov2 op1,op2,op3,op4 {
      mov  op1,op2
        mov  op1,op3
        mov  op1,op4
}

macro m_message [param1] {
       common
      mov2 eax,param1
     reverse
     mov  eax,param1
}
m_message 0xFFFFF,0xFEEEE,0xFDDDD

004020AF  |. B8 FFFF0F00    MOV EAX,0FFFFF   ;mov2
004020B4  |. B8 EEEE0F00    MOV EAX,0FEEEE   ;mov2
004020B9  |. B8 DDDD0F00    MOV EAX,0FDDDD   ;mov2
004020BE  |. B8 DDDD0F00    MOV EAX,0FDDDD   ;reverse
004020C3  |. B8 EEEE0F00    MOV EAX,0FEEEE   ;reverse
004020C8  |. B8 FFFF0F00    MOV EAX,0FFFFF   ;reverse

26 Dec 2004, 20:03

vid
Verbosity in development

Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia

vid 26 Dec 2004, 22:25

Quote:

does this mean, this can't be assembled is because of the "comma (,)" coz when processed it would be translated into
mov eax,0x11,0x22,0x33?

yes (if i understood your english right). Really try reading that tutorial, there can be many things you won't find out by yourself so soon.

26 Dec 2004, 22:25

vbVeryBeginner

Joined: 15 Aug 2004
Posts: 884
Location: \\world\asia\malaysia

vbVeryBeginner 27 Dec 2004, 04:57

yup, i guess u understood my english :[o],

well, i am reading the fasm manual too

Quote:

there can be many things you won't find out by yourself so soon.

sounds like they masked those secrets with simple words :p

anyway, thanks for confirming my understanding Smile

27 Dec 2004, 04:57

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