FreeTDS Development Group

[LacaK <lacak AT zoznam.sk>]

Frediano Ziglio  wrote / napísal(a):
> 2014-04-10 8:48 GMT+01:00 LacaK <lacak AT zoznam.sk>:
>   
> > > 24 ?? On my 64 bit machine is 16 and should be 16.
> > >       
> > I did some testing and googling and it seems, that inter - padding in
> > structures can vary compiler to compiler.
> > (as C++ standard does not strictly defines binary layout)
> > It seems, that Microsoft uses his "own padding and sizing" with bit-fields.
> >
> > I did small change in TDS_DATETIMEALL, which gives me now 16 bytes size (as
> > in your case):
> > typedef struct
> > {
> >    TDS_UINT8    time;    /* time, 7 digit precision */
> >    TDS_INT      date;    /* date, 0 = 1900-01-01 */
> >    TDS_SMALLINT offset;    /* time offset */
> > // HERE "unsigned short" instead of "unsigned":
> >    unsigned short time_prec:4;
> >    unsigned short has_time:1;
> >    unsigned short has_date:1;
> >    unsigned short has_offset:1;
> > } TDS_DATETIMEALL;
> >
> > So now we have: 8 bytes + 4 bytes + 2 bytes + 2 bytes = 16 bytes (seems,
> > that no padding occurs at end because 16 mod 8 = 0)
> > Can you change please "unsigned" to "unsigned short" in definition of
> > TDS_DATETIMEALL ?
> >
> > -Laco.
> >     
>
>
> Was thinking the same. Probably even better TDS_USMALLINT
>   
I see, that you have already commited this change. Thanks.
Now I hope, that this struct will not change "often" in future, else it 
will break applications which will rely on exact binary layout of it.
(like other languages which link to dblib.dll)
-Laco.