'out of scope' why?

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xRom

Joined: 26 Apr 2011
Posts: 13

xRom 06 Nov 2011, 20:51

Why this code compiling normally

Code:

struc     _win x,y {
          %w        = $
               .1   dw        x
               .2   dw        y     
          %w1 = $ - %w  
          
}     

          mov       eax,%w1
          
section '.data' data readable writeable
w3        _win      10,20 ;one defined

But this - no?

Code:

struc     _win x,y {
          %w        = $
               .1   dw        x
               .2   dw        y     
          %w1 = $ - %w
          
}     

          mov       eax,%w1
          
section '.data' data readable writeable
w3        _win      10,20    ;one defined
w4        _win      20,30    ;two defined

FASM error message:

Quote:

mov eax,%w1
error: symbol '%w1' out of scope.

06 Nov 2011, 20:51

vid
Verbosity in development

Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia

vid 06 Nov 2011, 20:55

are you sure the second code really has "mov eax,w3.%w1"? The error code only says "mov eax,%w1".

06 Nov 2011, 20:55

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20451
Location: In your JS exploiting you and your system

revolution 06 Nov 2011, 20:56

Use the dot.

Code:

.%w        = $
;...
.%w1 = $ - .%w

BTW: Your first code does not compile normally: error: undefined symbol 'w3.%w1'

06 Nov 2011, 20:56

vid
Verbosity in development

Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia

vid 06 Nov 2011, 20:57

You edited your post while I was typing my previous answer, disregard it. For answer to your question, read http://flatassembler.net/docs.php?article=manual#1.2.3

06 Nov 2011, 20:57

xRom

Joined: 26 Apr 2011
Posts: 13

xRom 06 Nov 2011, 20:59

vid wrote:

are you sure the second code really has "mov eax,w3.%w1"? The error code only says "mov eax,%w1".

Sorry, a'm corrected. But still don't work.

06 Nov 2011, 20:59

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20451
Location: In your JS exploiting you and your system

revolution 06 Nov 2011, 21:03

The reason you get out of scope is because you are defining %w1 and later redefining %w1 again. You can't forward reference variables that are redefined. Use the dot like I showed above.

06 Nov 2011, 21:03

xRom

Joined: 26 Apr 2011
Posts: 13

xRom 06 Nov 2011, 21:23

revolution wrote:

The reason you get out of scope is because you are defining %w1 and later redefining %w1 again. You can't forward reference variables that are redefined. Use the dot like I showed above.

Greate thanks, but if I can not use the name of the structure in this case (which I do not know beforehand)? how calculate the offset fields inside the structure so as not to write later in the procedure:

mov eax,[ebp+10]

and write

mov eax,[ebp+%window.size]

for example? If procedure is one, and macro 'window' are two? or more?

06 Nov 2011, 21:23

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20451
Location: In your JS exploiting you and your system

revolution 06 Nov 2011, 21:35

If you want the size of the structure use this:

Code:

struc _win x,y {
 .1      dw      x
   .2      dw      y          
}
virtual
    _win _win 0,0
       _win.size = $-$$
end virtual

;...

mov eax,_win.size

06 Nov 2011, 21:35

xRom

Joined: 26 Apr 2011
Posts: 13

xRom 07 Nov 2011, 06:46

revolution wrote:

virtual
_win _win 0,0
_win.size = $-$$
end virtual
;...
mov eax,_win.size[/code]

Thanx! This is work. But i'm not understand why Embarassed

07 Nov 2011, 06:46

goldenspider

Joined: 16 May 2011
Posts: 38

goldenspider 07 Nov 2011, 07:32

Or you can use struct.

Code:

struct   _win
    1   dw  ?
    2   dw  ?
ends

...
     movzx eax,[w3.1]
     mov   eax,sizeof._win
     mov   eax,sizeof._win.1

...
w3 _win 10,20

07 Nov 2011, 07:32

xRom

Joined: 26 Apr 2011
Posts: 13

xRom 07 Nov 2011, 08:24

goldenspider wrote:

Or you can use struct.
w3 _win 10,20[/code]

thanx! it's work. but what is it - struct? in manual http://flatassembler.net/docs.php?article=manual#2.3.4 - no about this...

07 Nov 2011, 08:24

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20451
Location: In your JS exploiting you and your system

revolution 07 Nov 2011, 08:30

xRom wrote:

thanx! it's work. but what is it - struct? in manual http://flatassembler.net/docs.php?article=manual#2.3.4 - no about this...

It is a macro, not a directive. You can see the definition in 'macro\struct.inc'. And the documentation is here

07 Nov 2011, 08:30

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