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#include <assert.h>
#include <stddef.h>
// from linux/kernel.h
#ifndef container_of
#define container_of(ptr, type, member) ({ \
const typeof(((type *) 0)->member) *__mptr = (ptr); \
(type *) ((char *) __mptr - offsetof(type, member));})
#endif
struct NetClientState {
int dummy;
/* ... */
};
struct NICState {
struct NetClientState nc;
struct NetClientState nc2;
void *opaque;
/* ... */
};
typedef int OpenEthState;
#define OPEN_ETH_STATE(a) \
((OpenEthState *) container_of(a, struct NICState, nc)->opaque)
#define OPEN_ETH_STATE2(a) \
((OpenEthState *) container_of(a, struct NICState, nc2)->opaque)
static struct NetClientState *nc;
int main()
{
int x=42;
struct NICState nic;
#ifndef __GNUC__
int *xptr=0, *xptr2=0;
const struct NetClientState *__mptr1=0, *__mptr2=0;
#endif
nic.opaque = &x;
nc = &(nic.nc);
assert(x==42);
assert(*((int*)nic.opaque) == 42);
#ifdef __GNUC__
int *xptr = OPEN_ETH_STATE(nc);
#else
__mptr1 = nc;
xptr = (OpenEthState *)
((struct NICState *)
((char *) __mptr1 - offsetof(struct NICState, nc)))->opaque;
#endif
assert(xptr == &x);
assert(*xptr == 42);
nc = &(nic.nc2);
#ifdef __GNUC__
int *xptr2 = OPEN_ETH_STATE2(nc);
#else
__mptr2 = nc;
xptr2 = (OpenEthState *)
((struct NICState *)
((char *) __mptr2 - offsetof(struct NICState, nc2)))->opaque;
#endif
assert(xptr2 == &x);
assert(*xptr2 == 42);
return 0;
}
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