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#include <stdbool.h>
#include <stdlib.h>
typedef struct list_t
{
int value;
struct list_t *next;
} list_t;
#define MIN_VALUE -10
#define MAX_VALUE 10
bool is_list(list_t *l, size_t len)
{
if(len == 0)
return l == NULL;
else
return __CPROVER_is_fresh(l, sizeof(*l)) &&
(MIN_VALUE <= l->value && l->value <= MAX_VALUE) &&
is_list(l->next, len - 1);
}
typedef struct buffer_t
{
size_t size;
char *arr;
} buffer_t;
typedef struct double_buffer_t
{
buffer_t *first;
buffer_t *second;
} double_buffer_t;
#define MIN_BUFFER_SIZE 1
#define MAX_BUFFER_SIZE 10
bool is_sized_array(char *arr, size_t size)
{
return (MIN_BUFFER_SIZE <= size && size <= MAX_BUFFER_SIZE) &&
__CPROVER_is_fresh(arr, size);
}
bool is_buffer(buffer_t *b)
{
return __CPROVER_is_fresh(b, sizeof(*b)) && is_sized_array(b->arr, b->size);
}
bool is_double_buffer(double_buffer_t *b)
{
return __CPROVER_is_fresh(b, sizeof(*b)) && is_buffer(b->first) &&
is_buffer(b->second);
}
#define LIST_LEN 3
int foo(list_t *l, double_buffer_t *b)
// clang-format off
__CPROVER_requires(is_list(l, LIST_LEN))
__CPROVER_requires(is_double_buffer(b))
__CPROVER_ensures(
(2 * MIN_BUFFER_SIZE + LIST_LEN * MIN_VALUE) <= __CPROVER_return_value &&
__CPROVER_return_value <= (2 * MAX_BUFFER_SIZE + LIST_LEN * MAX_VALUE))
// clang-format on
{
// access the assumed data structure
return l->value + l->next->value + l->next->next->value + b->first->size +
b->second->size;
}
int main()
{
list_t *l;
double_buffer_t *b;
int return_value = foo(l, b);
}
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