Creating named variables on the stack

Question

Is there a way to create named variables on the stack, rather access them using offset:

sub esp, 0x10 ; 4 variables of 4 bytes

mov DWORD [ebp-4], 0xf ; 1st var
mov DWORD [ebp-8], 0xff  ; 2nd var
; and so on

Answer 1

Fasm

FASM supports local variables using macros created by ad-hoc that come with FASM.

include 'win32ax.inc' 

.code

  start:
        mov ax, 1

        call foo


  proc foo

      ;Local variables

      locals
        var1 dd ?
        var2 dw ?
      endl


      ;Use them as expected
      mov eax, [var1]
      lea ebx, [var2]

   ret
  endp 

This is compiled ¹ in

:00401000 66B80100                mov ax, 0001
:00401004 E800000000              call 00401009
:00401009 55                      push ebp
:0040100A 89E5                    mov ebp, esp
:0040100C 83EC08                  sub esp, 00000008
:0040100F 8B45F8                  mov eax, dword ptr [ebp-08]
:00401012 8D5DFC                  lea ebx, dword ptr [ebp-04]
:00401015 C9                      leave
:00401016 C3                      ret

NASM

NASM also supports local variables using the % local directive .

Quote from the manual:

silly_swap: 
    %push mycontext             ; save the current context 
    %stacksize small            ; tell NASM to use bp 
    %assign %$localsize 0       ; see text for explanation 
    %local old_ax:word, old_dx:word 

    enter   %$localsize,0   ; see text for explanation 
    mov     [old_ax],ax     ; swap ax & bx 
    mov     [old_dx],dx     ; and swap dx & cx 
    mov     ax,bx 
    mov     dx,cx 
    mov     bx,[old_ax] 
    mov     cx,[old_dx] 
    leave                   ; restore old bp 
    ret                     ; 

    %pop                        ; restore original context

The variable is %$localsizeused internally with the directive %localand must be defined in the current context before the local% directive is used.

Other sloppy approaches

%define SUPER_VAR ebp-4
%define MEGA_VAR ebp-8

mov DWORD [SUPER_VAR], 0xf
mov DWORD [MEGA_VAR], 0xff

, .

:

%define SUPER_VAR 4
%define MEGA_VAR 8

mov DWORD [ebp-SUPER_VAR], 0xf
mov DWORD [ebp-MEGA_VAR], 0xff

^[] .
vi. emacs?

mov DWORD [ebp-4], 0xf           ;SUPER_VAR
mov DWORD [ebp-8], 0xff          ;MEGA_VAR

( , ).

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, . . , FASM NASM .

---

¹ ...
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Answer 2

FASM virtual :

:

virtual at ebp + 8
  .arg1 dd ?
  .arg2 dq ?
end virtual

:

virtual at ebp - 10h  ; the offset is the size of the local variables area.
  .var1        dd ?
  .local_array rb 12
end virtual

proc virtual .