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/**
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
* SPDX-License-Identifier: Apache-2.0.
*/
#undef memcpy
#include <proof_helpers/nondet.h>
#include <stdint.h>
/**
* Override the version of memcpy used by CBMC. Users may not want to pay
* for the cost of performing the computation of memcpy in proofs. In that
* case, this stub at least checks for the preconditions and make sure to
* havoc all elements pointed by *dst up to n.
*/
void *memcpy_impl(void *dst, const void *src, size_t n) {
__CPROVER_precondition(
__CPROVER_POINTER_OBJECT(dst) != __CPROVER_POINTER_OBJECT(src) ||
((const char *)src >= (const char *)dst + n) || ((const char *)dst >= (const char *)src + n),
"memcpy src/dst overlap");
__CPROVER_precondition(src != NULL && __CPROVER_r_ok(src, n), "memcpy source region readable");
__CPROVER_precondition(dst != NULL && __CPROVER_w_ok(dst, n), "memcpy destination region writeable");
if (n > 0) {
size_t index;
__CPROVER_assume(index < n);
((uint8_t *)dst)[index] = nondet_uint8_t();
}
return dst;
}
void *memcpy(void *dst, const void *src, size_t n) {
return memcpy_impl(dst, src, n);
}
void *__builtin___memcpy_chk(void *dst, const void *src, __CPROVER_size_t n, __CPROVER_size_t size) {
(void)size;
return memcpy_impl(dst, src, n);
}
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