Macro for struct.

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Roman

Joined: 21 Apr 2012
Posts: 1878

Roman 26 Jan 2021, 01:27

I write on Fasmw 1.73
I want do auto register for struct

Code:

Struct ar
A dd 0
B dw 0
C db 0
E dq 0
Ends

Macro n cval {} ;some magic

Mov rax, 0xff3040ee
 n ar.A ;generate Mov [ar.A], eax
 n ar.B ;generate Mov [ar.B], ax
 n ar.C ;generate Mov [ar.C], al
 n ar.E ;generate Mov [ar.E], rax

How do this?

26 Jan 2021, 01:27

bitRAKE

Joined: 21 Jul 2003
Posts: 4156
Location: vpcmpistri

bitRAKE 26 Jan 2021, 18:01

I'm way out of practice with fasm1, but if you had the size you could do:

Code:

macro n cval,sz {
      rept 1 i:sz \{
      match X|=i:A|Y,||1:al|2:ax|4:eax|8:rax|| \\{
            mov [cval],A
      \\}
      \}
}

(In fasmg labels have a size. Razz

)

_________________
¯\(°_o)/¯ “languages are not safe - uses can be” Bjarne Stroustrup

26 Jan 2021, 18:01

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8367
Location: Kraków, Poland

Tomasz Grysztar 26 Jan 2021, 18:25

Wow, that's a nice trick!

The standard "struct" macro for fasm defines some additional constants that you could use:

Code:

include 'macro/struct.inc'

struct ar
 A dd 0
 B dw 0
 C db 0
 E dq 0
ends

display '0'+sizeof.ar.A

but to have them at preprocessing time you might have to alter the macro.

26 Jan 2021, 18:25

Roman

Joined: 21 Apr 2012
Posts: 1878

Roman 27 Jan 2021, 06:03

Srt ar
Why we not get size Srt. X?
But fine get size of struct ar.

27 Jan 2021, 06:03

bitRAKE

Joined: 21 Jul 2003
Posts: 4156
Location: vpcmpistri

bitRAKE 27 Jan 2021, 20:44

Code:

macro na cval,parent {
  local sz
  sz = sizeof.#parent
  if sz = 1
    mov [cval],al
  else if sz = 2
    mov [cval],ax
  else if sz = 4
    mov [cval],eax
  else if sz = 8
    mov [cval],rax
  else
    display "size of item is not register size"
    err
  end if
}

...but it needs to be used like:

Code:

child ar ; define an instance
na child.A,ar.A

STRUCT wasn't meant to support this, but a slight change would make it work? Like have each instance creation define the label "name#.parent" and then get the parent within the "n" macro?

_________________
¯\(°_o)/¯ “languages are not safe - uses can be” Bjarne Stroustrup

27 Jan 2021, 20:44

Roman

Joined: 21 Apr 2012
Posts: 1878

Roman 28 Jan 2021, 05:29

Thanks bitRAKE !
Work fine.
I little modified.

Code:

  macro sSv cval {
  local sz
  sz = cval#_tp
  if sz = 1
    mov [cval],al
  else if sz = 2
    mov [cval],ax
  else if sz = 4
    mov [cval],eax
  else if sz = 8
    mov [cval],rax
  else
    display "size of item is not register size"
    err
  end if
}           
     mov  eax,0xff3040aa
     zio.A_tp equ sizeof.ar.A ;would be nice if some macro do this automatically.
     zio.B_tp equ sizeof.ar.B
     zio.C_tp equ sizeof.ar.C
     sSv  zio.A
     sSv  zio.B
     sSv  zio.C

Last edited by Roman on 28 Jan 2021, 05:57; edited 1 time in total

28 Jan 2021, 05:29

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