ASM Community

hii
i want to translet this

typedef struct {

	BYTE type;

	union {

		BYTE bVal; char cVal;

		WORD wVal; short sVal;

		DWORD dVal; long lVal;

		struct {

			char *pszVal;

			WORD cchVal;   //only used for db/contact/getsettingstatic

		};

		struct {

			WORD cpbVal;

			BYTE *pbVal;

		};

	};

} DBVARIANT;

if found a translation to

DBVARIANT struct

    ttype		db ?;

    val		dd ?

    pblob		dd ?

 DBVARIANT ends;

is this right translation ?
i know what is union but i dont know what to do with the struct(s)

bye
thanks
eko

lets count the bytes of this var without the union

two bytes = 2
3 word *2 = 6
(1 dword + 2 pointers (dword) ) *4 = 12
_____________________________
20 bytes totaly with out the union

with the union we have

somestruct struct

onebyte db ? ;not include in the union

somedword dd ? ; byte word and dword all on the dword location

somebytes db 6 dup (?)

somestruct ends 



EDIT:

or maybe somebytes can include somedword 

and the struct will be 

somestruct struct

onebyte db ?

somebytes db 6 dup (?)

somestruct ends 

and 

right ?

bye
thanks
eko

I don't know how to do it with MASM, but with TASM in Ideal mode, it's:

TYPEDEF CHAR    BYTE    ; Works if a "char" is 1 byte

TYPEDEF SHORT   WORD    ; Works if a "short" is 2 bytes

TYPEDEF LONG    DWORD   ; Works if a "long" is 4 bytes

TYPEDEF POINTER DWORD   ; Assuming an address is 4 bytes



STRUC   DBVARIANT

    vtype   DB      ?

    UNION

        bVal    DB      ?

        cVal    CHAR    ?

        wVal    DW      ?

        sVal    SHORT   ?

        dVal    DD      ?

        lVal    LONG    ?

        STRUC

            pszVal  POINTER ?

            cchVal  WORD    ?

        ENDS

        STRUC

            cpbVal  WORD    ?

            pbVal   POINTER ?

        ENDS

    ENDS

ENDS    DBVARIANT

I guess it would be something similar in MASM, if nested aggregate types are possible at all.

Note that I've changed the name of the member "type" to be "vtype". This is because "type" is already a predefined symbol in TASM, it confuses the assembler if you use a predefined symbol as a member name.

Also, with TASM there is a utility called H2ASH which converts a .H file with these kinds of typedefs into ASM code. Maybe something similar exists with MASM.