1//===-- bcmp_fuzz.cpp ---------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8///
9/// Fuzzing test for llvm-libc bcmp implementation.
10///
11//===----------------------------------------------------------------------===//
12#include "src/strings/bcmp.h"
13#include <stddef.h>
14#include <stdint.h>
15#include <stdio.h>
16#include <string.h>
17
18static int reference_bcmp(const void *pa, const void *pb, size_t count)
19 __attribute__((no_builtin)) {
20 const auto *a = reinterpret_cast<const unsigned char *>(pa);
21 const auto *b = reinterpret_cast<const unsigned char *>(pb);
22 for (size_t i = 0; i < count; ++i, ++a, ++b)
23 if (*a != *b)
24 return 1;
25 return 0;
26}
27
28extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
29 const auto normalize = [](int value) -> int {
30 if (value == 0)
31 return 0;
32 return 1;
33 };
34 // We ignore the last byte is size is odd.
35 const auto count = size / 2;
36 const char *a = reinterpret_cast<const char *>(data);
37 const char *b = reinterpret_cast<const char *>(data) + count;
38 const int actual = LIBC_NAMESPACE::bcmp(a, b, count);
39 const int reference = reference_bcmp(pa: a, pb: b, count);
40 if (normalize(actual) == normalize(reference))
41 return 0;
42 const auto print = [](const char *msg, const char *buffer, size_t size) {
43 printf(format: "%s\"", msg);
44 for (size_t i = 0; i < size; ++i)
45 printf(format: "\\x%02x", (uint8_t)buffer[i]);
46 printf(format: "\"\n");
47 };
48 printf(format: "count : %zu\n", count);
49 print("a : ", a, count);
50 print("b : ", b, count);
51 printf(format: "expected : %d\n", reference);
52 printf(format: "actual : %d\n", actual);
53 __builtin_trap();
54}
55

source code of libc/fuzzing/string/bcmp_fuzz.cpp