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Index > Windows > import macro improvement?

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Phrodu



Joined: 19 Jun 2004
Posts: 1
Phrodu
I found a way to get rid of 2, seemingly unnecessary, extra bytes at the front of each imported function. In the import macro, inside macro\import.inc, I changed:
Code:
label dd RVA _label

to

label dd RVA _label-2
    


and

Code:
_label dw 0
       db string,0

to

_label db string,0
    


to get:
Code:
macro import name,[label,string]
 { common
    name:
   forward
    if used label
     if string eqtype ''
      local _label
      label dd RVA _label-2
     else
      label dd 80000000h + string
     end if
    end if
   common
    if $ > name
     name#.redundant = 0
     dd 0
    else
     name#.redundant = 1
    end if
   forward
    if used label & string eqtype ''
    _label db string,0
    end if }
    



I'm not very experienced with macros or the structure of PE's, but this seems to work alright. Why were those 2 bytes there? Are there any reasons to not use this new way?
Post 19 Jun 2004, 21:21
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Tommy



Joined: 17 Jun 2003
Posts: 489
Location: Norway
Tommy
Aren't they there for unicode support or something? Confused
Post 19 Jun 2004, 21:48
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Tomasz Grysztar



Joined: 16 Jun 2003
Posts: 7752
Location: Kraków, Poland
Tomasz Grysztar
That 16-bit value should contain a "hint" what ordinal number the function has, so the PE loader can find it faster. If the hint is wrong, the value is ignored, and loader just scans the sorted export table of DLL to find the function.
Post 19 Jun 2004, 21:50
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