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/*
* 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 memcpy
#include <cbmc_proof/nondet.h>
#include <stdint.h>
/**
* Overrides 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
* assigns arbitrary values to *dst.
*/
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");
__CPROVER_havoc_object(dst);
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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