LLVM  4.0.0
CustomCrossOverTest.cpp
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1 // This file is distributed under the University of Illinois Open Source
2 // License. See LICENSE.TXT for details.
3 
4 // Simple test for a cutom mutator.
5 #include <assert.h>
6 #include <cstddef>
7 #include <cstdint>
8 #include <cstdlib>
9 #include <iostream>
10 #include <random>
11 #include <string.h>
12 
13 #include "FuzzerInterface.h"
14 
15 static const char *Separator = "-_^_-";
16 static const char *Target = "012-_^_-abc";
17 
18 static volatile int sink;
19 
20 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
21  assert(Data);
22  std::string Str(reinterpret_cast<const char *>(Data), Size);
23 
24  // Ensure that two different elements exist in the corpus.
25  if (Size && Data[0] == '0') sink++;
26  if (Size && Data[0] == 'a') sink--;
27 
28  if (Str.find(Target) != std::string::npos) {
29  std::cout << "BINGO; Found the target, exiting\n";
30  exit(1);
31  }
32  return 0;
33 }
34 
35 extern "C" size_t LLVMFuzzerCustomCrossOver(const uint8_t *Data1, size_t Size1,
36  const uint8_t *Data2, size_t Size2,
37  uint8_t *Out, size_t MaxOutSize,
38  unsigned int Seed) {
39  static bool Printed;
40  static size_t SeparatorLen = strlen(Separator);
41 
42  if (!Printed) {
43  std::cerr << "In LLVMFuzzerCustomCrossover\n";
44  Printed = true;
45  }
46 
47  std::mt19937 R(Seed);
48 
49  size_t Offset1 = 0;
50  size_t Len1 = R() % (Size1 - Offset1);
51  size_t Offset2 = 0;
52  size_t Len2 = R() % (Size2 - Offset2);
53  size_t Size = Len1 + Len2 + SeparatorLen;
54 
55  if (Size > MaxOutSize)
56  return 0;
57 
58  memcpy(Out, Data1 + Offset1, Len1);
59  memcpy(Out + Len1, Separator, SeparatorLen);
60  memcpy(Out + Len1 + SeparatorLen, Data2 + Offset2, Len2);
61 
62  return Len1 + Len2 + SeparatorLen;
63 }
static cl::opt< unsigned long long > Seed("rng-seed", cl::value_desc("seed"), cl::desc("Seed for the random number generator"), cl::init(0))
int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
static const char * Separator
static const char * Target
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
static volatile int sink
size_t LLVMFuzzerCustomCrossOver(const uint8_t *Data1, size_t Size1, const uint8_t *Data2, size_t Size2, uint8_t *Out, size_t MaxOutSize, unsigned int Seed)