compiler-rt/test/fuzzer/CustomCrossOverTest.cpp

   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 // Simple test for a custom crossover.
   6 #include <assert.h>
   7 #include <cstddef>
   8 #include <cstdint>
   9 #include <cstdlib>
  10 #include <iostream>
  11 #include <ostream>
  12 #include <random>
  13 #include <string.h>
  14 #include <functional>
  15
  16 static const char *Separator = "-########-";
  17 static const char *Target = "A-########-B";
  18
  19 static volatile int sink;
  20
  21 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
  22   assert(Data);
  23   std::string Str(reinterpret_cast<const char *>(Data), Size);
  24   static const size_t TargetHash = std::hash<std::string>{}(std::string(Target));
  25   size_t StrHash = std::hash<std::string>{}(Str);
  26
  27   // Ensure we have 'A' and 'B' in the corpus.
  28   if (Size == 1 && *Data == 'A')
  29     sink++;
  30   if (Size == 1 && *Data == 'B')
  31     sink--;
  32
  33   if (TargetHash == StrHash) {
  34     std::cout << "BINGO; Found the target, exiting\n" << std::flush;
  35     exit(1);
  36   }
  37   return 0;
  38 }
  39
  40 extern "C" size_t LLVMFuzzerCustomCrossOver(const uint8_t *Data1, size_t Size1,
  41                                             const uint8_t *Data2, size_t Size2,
  42                                             uint8_t *Out, size_t MaxOutSize,
  43                                             unsigned int Seed) {
  44   static size_t Printed;
  45   static size_t SeparatorLen = strlen(Separator);
  46
  47   if (Printed++ < 32)
  48     std::cerr << "In LLVMFuzzerCustomCrossover " << Size1 << " " << Size2 << "\n";
  49
  50   size_t Size = Size1 + Size2 + SeparatorLen;
  51
  52   if (Size > MaxOutSize)
  53     return 0;
  54
  55   memcpy(Out, Data1, Size1);
  56   memcpy(Out + Size1, Separator, SeparatorLen);
  57   memcpy(Out + Size1 + SeparatorLen, Data2, Size2);
  58
  59   return Size;
  60 }