1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
|
/*
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License"). You may not use
* this file except in compliance with the License. A copy of the License is
* located at
*
* http://aws.amazon.com/apache2.0/
*
* or in the "license" file accompanying this file. This file is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing permissions and
* limitations under the License.
*/
#undef memset
#include <cbmc_proof/nondet.h>
#include <stddef.h>
/**
* Override the version of memset used by CBMC. Users may not want to pay
* for the cost of performing the computation of memset in proofs. In that
* case, this stub at least checks for the preconditions and make sure to
* havoc all elements pointed by *s up to n.
*/
void *memset_impl(void *s, int c, size_t n) {
__CPROVER_precondition(__CPROVER_w_ok(s, n), "memset destination region writeable");
if (n > 0) {
size_t idx;
__CPROVER_assume(idx < n);
((uint8_t *)s)[idx] = nondet_uint8_t();
}
return s;
}
void *memset(void *s, int c, size_t n) {
return memset_impl(s, c, n);
}
void *__builtin___memset_chk(void *s, int c, size_t n, size_t os) {
(void)os;
return memset_impl(s, c, n);
}
|
