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typedef struct
{
int *x;
int *y;
/*@dependent@*/ int *z;
} *pair;
extern void pair_keep (/*@keep@*/ pair p);
extern /*@only@*/ /*@out@*/ void *smalloc (size_t);
extern /*@partial@*/ pair pair_part (void);
/*@only@*/ pair pair_copy (pair p)
{
pair ret = (pair) smalloc (sizeof (*ret));
ret->x = p->x;
ret->y = p->y;
ret->z = p->z;
return (ret); /* 1. Storage p->x reachable from parameter is kept (should be only) */
} /* 2. Storage p->y reachable from parameter is kept (should be only) */
/*@only@*/ pair pair_create (void)
{
pair p = (pair) smalloc (sizeof (*p));
p->x = smalloc (sizeof (int));
p->y = smalloc (sizeof (int));
p->z = p->y; /* 3. Only storage p->y assigned to dependent: p->z = p-y */
*(p->x) = 3;
*(p->y) = 12;
return p; /* 4. Storage p->y reachable from return value is unqualified */
}
pair pair_swankle (/*@keep@*/ pair p)
{
pair ret = pair_part ();
ret->x = p->x;
pair_keep (p); /* 5. Storage p->x reachable from passed parameter is kept */
p->x = smalloc (sizeof (int));
*p->x = 3;
return ret;
}
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