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Joined: 09 Dec 2004
Posts: 141
Location: Russia, Murmansk region
IronFelix 09 Dec 2004, 14:20
Hello, everybody!
Not so far I used MASM to write programs in assembler language, but when I found FASM, I have seen some of its advantages and now I study this assembler language. I likes it for its simplicity an because of opportunity to write everything I need by myself.
Now let me show the result of my study. I have read some useful topics of this forum and try to combine what I have read into some useful thing.
Please, don't be very critic to me.

Now, union macro:

; macro for declaring a union

macro union _name,[def] 
 common size@union = 0 
         origin@union = $ 
   if $-origin@union > size@union 
    size@union = $-origin@union 
   end if 
  end virtual 
 local ..array
 struc _name {
..array  rb size@union
  virtual at ..array
  end virtual

uend fix }

;********   example of usage   **********

; declaring a union

union MYUNION,\
       .value1             dd              ?     ,\
       .value2             db              ?     ,\
       .struct1            SOMESTRUCT            ,\
       .value3             rb              100     

; defining variable


; acessing fields

 mov eax,[Union1.value1]
 mov al,[Union1.value2]
 mov eax,[Union1.struct1.some_struct_field]
; ... and so on

; it is possible to write in this way:

 .a     dd   ?
 .b     MYUNION
 .c     db   ?

; or to create unions of structures:

union MYUNION,\
       .value1             SOMESTRUCT1                   ,\
       .value2             SOMESTRUCT2          

If it isn't hard for you, please test this macro and tell me about my mistakes.

Flat Assembler is the best!
Post 09 Dec 2004, 14:20
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