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 20 static volatile int Sink; 21 static 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 26 static 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); 42 static const uint32_t ExpectedHash = 0xe1677acb; 43 44 extern "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