On Thu, Feb 15, 2007 at 01:53:58PM -0800, Andrew Morton wrote:
> > The whole union thing was only needed to get rid of a warning but Marcel's
> > solution does the same thing by attaching the packed keyword to the entire
> > structure instead, so this patch is now using his macros but using __packed
> > instead.
>
> How do we know this trick will work as-designed across all versions of gcc
> and icc (at least) and for all architectures and for all sets of compiler
> options?
>
> Basically, it has to be guaranteed by a C standard. Is it?
Gcc info page says:
[...]
`packed'
The `packed' attribute specifies that a variable or structure field
should have the smallest possible alignment--one byte for a
variable, and one bit for a field, unless you specify a larger
value with the `aligned' attribute.
[...]
Qed?
Ralf
