how is it possible to handle the structs in 64 bits?

[GUAN DE DIO]

Hi everybody,

      I'm doing my first experience in 64 bit platform and I have some doubt about the struct handling.

      Fistly I tried to do something like this:

     ; wc is a variable type WNDCLASSEX

   lea rsi, wc
   assume rsi: ptr WNDCLASSEX
      mov [rsi].cbSize,sizeof WNDCLASSEX
   assume rsi:NOTHING

     But this code does not compile.

     Secondly I tried this

   lea rsi, wc
   mov dword ptr ds:[rsi],sizeof WNDCLASSEX
   
      but doesn't work

    What is the way to handle structs in 64 bits?

Best Regards,
GUAN

[MazeGen]

This worked fine for me some months ago, when I was playing with Iczelion's tute 03:

Code Select Expand


WinMain PROC FRAME ;hInst:HINSTANCE, hPrevInst:HINSTANCE, CmdLine:LPSTR, CmdShow:DWORD
;LOCAL  wc:WNDCLASSEX
;LOCAL  msg:MSG
;LOCAL  hwnd:HWND

push   rbp
.PUSHREG rbp

sub    rsp, 80t+32t+8+8
.ALLOCSTACK 80t+32t+8+8

mov    rbp, rsp
.SETFRAME rbp, 0

.ENDPROLOG

wc             EQU <(rbp+0).WNDCLASSEX>
msg            EQU <(rbp+80t).MSG>
hwnd           EQU <qword ptr (rbp+80t+32t)>

CmdShow        EQU <dword ptr (rbp+80t+32t+8+8 +8+8+24t)>
CmdLine        EQU <dword ptr (rbp+80t+32t+8+8 +8+8+16t)>
hPrevInst      EQU <qword ptr (rbp+80t+32t+8+8 +8+8+8)>
hInst          EQU <qword ptr (rbp+80t+32t+8+8 +8+8+0)>

mov    [hInst], rcx
mov    [hPrevInst], rdx
mov    [CmdLine], r8d
mov    [CmdShow], r9d

mov    [wc].cbSize, SIZEOF WNDCLASSEX
mov    [wc].style, CS_HREDRAW OR CS_VREDRAW
lea    rax, [WndProc]
mov    [wc].lpfnWndProc, rax
mov    [wc].cbClsExtra, NULL
mov    [wc].cbWndExtra, NULL
mov    rax, [hInst]
mov    [wc].hInstance, rax
mov    [wc].hbrBackground, COLOR_WINDOW+1
mov    [wc].lpszMenuName, NULL
lea    rax, [ClassName]
mov    [wc].lpszClassName, rax
...


[GUAN DE DIO]

Hi MazeGen,

Thanks for your request, but I have one doubt about it.

In 32 bit a lot of time we have a pointer to one struct in some register,  i.e in esi, for handling his struct we could make.

assume esi: ptr  THE NAME OF THE STRUCT

  ....

assume esi:NOTHING

How can we do something like this in 64 bits?

The example that you give me declares the variables for handling, but if I gave the pointer in a register ?

Best Regards,
GUAN

[MazeGen]

Yep, ASSUME doesn't seem to be supported in ML64.

You can use the longer notation though:

Code Select Expand


lea ebx, [wc]
mov [ebx].WNDCLASSEX.cbSize, SIZEOF WNDCLASSEX


[GUAN DE DIO]

OK thanks again

GUAN