1// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
2// See https://llvm.org/LICENSE.txt for license information.
3// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
4
5// Test for a fuzzer. The fuzzer must find the string
6// ABCDEFGHIJ
7// We use it as a test for each of CrossOver functionalities
8// by passing the following sets of two inputs to it:
9// {ABCDE00000, ZZZZZFGHIJ}
10// {ABCDEHIJ, ZFG} to specifically test InsertPartOf
11// {ABCDE00HIJ, ZFG} to specifically test CopyPartOf
12//
13#include <assert.h>
14#include <cstddef>
15#include <cstdint>
16#include <cstdlib>
17#include <iostream>
18#include <ostream>
19
20static volatile int Sink;
21static volatile int *NullPtr;
22
23// A modified jenkins_one_at_a_time_hash initialized by non-zero,
24// so that simple_hash(0) != 0. See also
25// https://en.wikipedia.org/wiki/Jenkins_hash_function
26static uint32_t simple_hash(const uint8_t *Data, size_t Size) {
27 uint32_t Hash = 0x12039854;
28 for (uint32_t i = 0; i < Size; i++) {
29 Hash += Data[i];
30 Hash += (Hash << 10);
31 Hash ^= (Hash >> 6);
32 }
33 Hash += (Hash << 3);
34 Hash ^= (Hash >> 11);
35 Hash += (Hash << 15);
36 return Hash;
37}
38
39// Don't leave the string in the binary, so that fuzzer don't cheat;
40// const char *ABC = "ABCDEFGHIJ";
41// static uint32_t ExpectedHash = simple_hash((const uint8_t *)ABC, 10);
42static const uint32_t ExpectedHash = 0xe1677acb;
43
44extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
45 // fprintf(stderr, "ExpectedHash: %x\n", ExpectedHash);
46 if (Size == 10 && ExpectedHash == simple_hash(Data, Size))
47 *NullPtr = 0;
48 if (*Data == 'A')
49 Sink++;
50 if (*Data == 'Z')
51 Sink--;
52 return 0;
53}
54