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Re: Does a zero-sized object in BSS go away?
Geoff Keating wrote:
[snip]
> > > ISO C programs can't create zero-size objects, but you can do it in
> > > GCC.
> > >
> > > I think there's no way to tell if an object, which the program thinks
> > > is zero-size, actually has non-zero size. So you could just make the
> > > common symbols have size 1 if the user asks for size 0...
> >
> > This may break pointer comparisions. (Not that I knew of a good reason
> > to do this).
>
> I don't see how this could break pointer comparisons.
Gcc allows to take the address of a zero-sized object:
struct a {
int b[0];
int c[0];
} d;
int main(void)
{
return &d.b == &d.c;
}
> You can't meaningfully do them with zero-size objects anyway...
It's probably (hopefully :-) only a theoretical point and not a
practical issue.
Thiemo