Re: [RFC v2 1/7] hashtable: introduce a small and naive hashtable

Tejun Heo
2012-08-03T22:36:34Z

On Fri, Aug 03, 2012 at 03:29:10PM -0700, Linus Torvalds wrote:
> On Fri, Aug 3, 2012 at 3:23 PM, Tejun Heo <tj@kernel.org> wrote:
> >
> > I actually meant an enclosing struct. When you're defining a struct
> > member, simply putting the storage after a struct with var array
> > should be good enough. If that doesn't work, quite a few things in
> > the kernel will break.
>
> The unsigned member of a struct has to be the last one, so your struct
> won't work.

I suppose you mean unsized. I remember this working. Maybe I'm
confusing it with zero-sized array. Hmm... gcc doesn't complain about
the following. --std=c99 seems happy too.

#include <stdio.h>

struct A {
int i;
long ar[];
};

struct B {
struct A a;
long ar_storage[32];
};

int main(void)
{
printf("sizeof(A)=%zd sizeof(B)=%zd\n", sizeof(struct A), sizeof(struct B));
return 0;
}

$ ./a.out
sizeof(A)=8 sizeof(B)=264

--
tejun