回复: PR 1098: "struct ipovly" not packed.

[ralf.corsepius at rtems.org (Ralf Corsepius)]

On Thu, 2006-07-06 at 21:22 -0400, Denny.Bai wrote:
> typedef struct {
>    long  l1;
>    short s1;
>    long  l2;
> } s2_t __attribute__((packed));  /* does nothing */
> 
> --------------------------------------------------
> 
> if above code changed like this, "__attribute__((packed))" will work
> and the warning will not appear again.
> 
> typedef struct {
>    long  l1;
>    short s1;
>    long  l2;
> }__attribute__((packed)) s2_t;

structs like the ones above are BAD DESIGN.

With or without __attribute((packed))__ there is no guarantee they will
work. If you have a look into the BSD structures we are talking about
here, they are designed in such a way that "packing" should not have any
effect.

Ralf