fuzzer/tests/FuzzerUnittest.cpp

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

// Avoid ODR violations (LibFuzzer is built without ASan and this test is built
// with ASan) involving C++ standard library types when using libcxx.
#define _LIBCPP_HAS_NO_ASAN

// Do not attempt to use LLVM ostream from gtest.
#define GTEST_NO_LLVM_RAW_OSTREAM 1

#include "FuzzerCorpus.h"
#include "FuzzerDictionary.h"
#include "FuzzerInternal.h"
#include "FuzzerMerge.h"
#include "FuzzerMutate.h"
#include "FuzzerRandom.h"
#include "FuzzerTracePC.h"
#include "gtest/gtest.h"
#include <memory>
#include <set>
#include <sstream>

using namespace fuzzer;

// For now, have LLVMFuzzerTestOneInput just to make it link.
// Later we may want to make unittests that actually call LLVMFuzzerTestOneInput.
extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
  abort();
}

TEST(Fuzzer, Basename) {
  EXPECT_EQ(Basename("foo/bar"), "bar");
  EXPECT_EQ(Basename("bar"), "bar");
  EXPECT_EQ(Basename("/bar"), "bar");
  EXPECT_EQ(Basename("foo/x"), "x");
  EXPECT_EQ(Basename("foo/"), "");
#if LIBFUZZER_WINDOWS
  EXPECT_EQ(Basename("foo\\bar"), "bar");
  EXPECT_EQ(Basename("foo\\bar/baz"), "baz");
  EXPECT_EQ(Basename("\\bar"), "bar");
  EXPECT_EQ(Basename("foo\\x"), "x");
  EXPECT_EQ(Basename("foo\\"), "");
#endif
}

TEST(Fuzzer, CrossOver) {
  std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
  fuzzer::EF = t.get();
  Random Rand(0);
  std::unique_ptr<MutationDispatcher> MD(new MutationDispatcher(Rand, {}));
  Unit A({0, 1, 2}), B({5, 6, 7});
  Unit C;
  Unit Expected[] = {
       { 0 },
       { 0, 1 },
       { 0, 5 },
       { 0, 1, 2 },
       { 0, 1, 5 },
       { 0, 5, 1 },
       { 0, 5, 6 },
       { 0, 1, 2, 5 },
       { 0, 1, 5, 2 },
       { 0, 1, 5, 6 },
       { 0, 5, 1, 2 },
       { 0, 5, 1, 6 },
       { 0, 5, 6, 1 },
       { 0, 5, 6, 7 },
       { 0, 1, 2, 5, 6 },
       { 0, 1, 5, 2, 6 },
       { 0, 1, 5, 6, 2 },
       { 0, 1, 5, 6, 7 },
       { 0, 5, 1, 2, 6 },
       { 0, 5, 1, 6, 2 },
       { 0, 5, 1, 6, 7 },
       { 0, 5, 6, 1, 2 },
       { 0, 5, 6, 1, 7 },
       { 0, 5, 6, 7, 1 },
       { 0, 1, 2, 5, 6, 7 },
       { 0, 1, 5, 2, 6, 7 },
       { 0, 1, 5, 6, 2, 7 },
       { 0, 1, 5, 6, 7, 2 },
       { 0, 5, 1, 2, 6, 7 },
       { 0, 5, 1, 6, 2, 7 },
       { 0, 5, 1, 6, 7, 2 },
       { 0, 5, 6, 1, 2, 7 },
       { 0, 5, 6, 1, 7, 2 },
       { 0, 5, 6, 7, 1, 2 }
  };
  for (size_t Len = 1; Len < 8; Len++) {
    Set<Unit> FoundUnits, ExpectedUnitsWitThisLength;
    for (int Iter = 0; Iter < 3000; Iter++) {
      C.resize(Len);
      size_t NewSize = MD->CrossOver(A.data(), A.size(), B.data(), B.size(),
                                     C.data(), C.size());
      C.resize(NewSize);
      FoundUnits.insert(C);
    }
    for (const Unit &U : Expected)
      if (U.size() <= Len)
        ExpectedUnitsWitThisLength.insert(U);
    EXPECT_EQ(ExpectedUnitsWitThisLength, FoundUnits);
  }
}

TEST(Fuzzer, Hash) {
  uint8_t A[] = {'a', 'b', 'c'};
  fuzzer::Unit U(A, A + sizeof(A));
  EXPECT_EQ("a9993e364706816aba3e25717850c26c9cd0d89d", fuzzer::Hash(U));
  U.push_back('d');
  EXPECT_EQ("81fe8bfe87576c3ecb22426f8e57847382917acf", fuzzer::Hash(U));
}

typedef size_t (MutationDispatcher::*Mutator)(uint8_t *Data, size_t Size,
                                              size_t MaxSize);

void TestEraseBytes(Mutator M, int NumIter) {
  std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
  fuzzer::EF = t.get();
  uint8_t REM0[8] = {0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
  uint8_t REM1[8] = {0x00, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
  uint8_t REM2[8] = {0x00, 0x11, 0x33, 0x44, 0x55, 0x66, 0x77};
  uint8_t REM3[8] = {0x00, 0x11, 0x22, 0x44, 0x55, 0x66, 0x77};
  uint8_t REM4[8] = {0x00, 0x11, 0x22, 0x33, 0x55, 0x66, 0x77};
  uint8_t REM5[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x66, 0x77};
  uint8_t REM6[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x77};
  uint8_t REM7[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66};

  uint8_t REM8[6] = {0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
  uint8_t REM9[6] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55};
  uint8_t REM10[6] = {0x00, 0x11, 0x22, 0x55, 0x66, 0x77};

  uint8_t REM11[5] = {0x33, 0x44, 0x55, 0x66, 0x77};
  uint8_t REM12[5] = {0x00, 0x11, 0x22, 0x33, 0x44};
  uint8_t REM13[5] = {0x00, 0x44, 0x55, 0x66, 0x77};


  Random Rand(0);
  std::unique_ptr<MutationDispatcher> MD(new MutationDispatcher(Rand, {}));
  int FoundMask = 0;
  for (int i = 0; i < NumIter; i++) {
    uint8_t T[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
    size_t NewSize = (*MD.*M)(T, sizeof(T), sizeof(T));
    if (NewSize == 7 && !memcmp(REM0, T, 7)) FoundMask |= 1 << 0;
    if (NewSize == 7 && !memcmp(REM1, T, 7)) FoundMask |= 1 << 1;
    if (NewSize == 7 && !memcmp(REM2, T, 7)) FoundMask |= 1 << 2;
    if (NewSize == 7 && !memcmp(REM3, T, 7)) FoundMask |= 1 << 3;
    if (NewSize == 7 && !memcmp(REM4, T, 7)) FoundMask |= 1 << 4;
    if (NewSize == 7 && !memcmp(REM5, T, 7)) FoundMask |= 1 << 5;
    if (NewSize == 7 && !memcmp(REM6, T, 7)) FoundMask |= 1 << 6;
    if (NewSize == 7 && !memcmp(REM7, T, 7)) FoundMask |= 1 << 7;

    if (NewSize == 6 && !memcmp(REM8, T, 6)) FoundMask |= 1 << 8;
    if (NewSize == 6 && !memcmp(REM9, T, 6)) FoundMask |= 1 << 9;
    if (NewSize == 6 && !memcmp(REM10, T, 6)) FoundMask |= 1 << 10;

    if (NewSize == 5 && !memcmp(REM11, T, 5)) FoundMask |= 1 << 11;
    if (NewSize == 5 && !memcmp(REM12, T, 5)) FoundMask |= 1 << 12;
    if (NewSize == 5 && !memcmp(REM13, T, 5)) FoundMask |= 1 << 13;
  }
  EXPECT_EQ(FoundMask, (1 << 14) - 1);
}

TEST(FuzzerMutate, EraseBytes1) {
  TestEraseBytes(&MutationDispatcher::Mutate_EraseBytes, 200);
}
TEST(FuzzerMutate, EraseBytes2) {
  TestEraseBytes(&MutationDispatcher::Mutate, 2000);
}

void TestInsertByte(Mutator M, int NumIter) {
  std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
  fuzzer::EF = t.get();
  Random Rand(0);
  std::unique_ptr<MutationDispatcher> MD(new MutationDispatcher(Rand, {}));
  int FoundMask = 0;
  uint8_t INS0[8] = {0xF1, 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66};
  uint8_t INS1[8] = {0x00, 0xF2, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66};
  uint8_t INS2[8] = {0x00, 0x11, 0xF3, 0x22, 0x33, 0x44, 0x55, 0x66};
  uint8_t INS3[8] = {0x00, 0x11, 0x22, 0xF4, 0x33, 0x44, 0x55, 0x66};
  uint8_t INS4[8] = {0x00, 0x11, 0x22, 0x33, 0xF5, 0x44, 0x55, 0x66};
  uint8_t INS5[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0xF6, 0x55, 0x66};
  uint8_t INS6[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0xF7, 0x66};
  uint8_t INS7[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0xF8};
  for (int i = 0; i < NumIter; i++) {
    uint8_t T[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66};
    size_t NewSize = (*MD.*M)(T, 7, 8);
    if (NewSize == 8 && !memcmp(INS0, T, 8)) FoundMask |= 1 << 0;
    if (NewSize == 8 && !memcmp(INS1, T, 8)) FoundMask |= 1 << 1;
    if (NewSize == 8 && !memcmp(INS2, T, 8)) FoundMask |= 1 << 2;
    if (NewSize == 8 && !memcmp(INS3, T, 8)) FoundMask |= 1 << 3;
    if (NewSize == 8 && !memcmp(INS4, T, 8)) FoundMask |= 1 << 4;
    if (NewSize == 8 && !memcmp(INS5, T, 8)) FoundMask |= 1 << 5;
    if (NewSize == 8 && !memcmp(INS6, T, 8)) FoundMask |= 1 << 6;
    if (NewSize == 8 && !memcmp(INS7, T, 8)) FoundMask |= 1 << 7;
  }
  EXPECT_EQ(FoundMask, 255);
}

TEST(FuzzerMutate, InsertByte1) {
  TestInsertByte(&MutationDispatcher::Mutate_InsertByte, 1 << 15);
}
TEST(FuzzerMutate, InsertByte2) {
  TestInsertByte(&MutationDispatcher::Mutate, 1 << 17);
}

void TestInsertRepeatedBytes(Mutator M, int NumIter) {
  std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
  fuzzer::EF = t.get();
  Random Rand(0);
  std::unique_ptr<MutationDispatcher> MD(new MutationDispatcher(Rand, {}));
  int FoundMask = 0;
  uint8_t INS0[7] = {0x00, 0x11, 0x22, 0x33, 'a', 'a', 'a'};
  uint8_t INS1[7] = {0x00, 0x11, 0x22, 'a', 'a', 'a', 0x33};
  uint8_t INS2[7] = {0x00, 0x11, 'a', 'a', 'a', 0x22, 0x33};
  uint8_t INS3[7] = {0x00, 'a', 'a', 'a', 0x11, 0x22, 0x33};
  uint8_t INS4[7] = {'a', 'a', 'a', 0x00, 0x11, 0x22, 0x33};

  uint8_t INS5[8] = {0x00, 0x11, 0x22, 0x33, 'b', 'b', 'b', 'b'};
  uint8_t INS6[8] = {0x00, 0x11, 0x22, 'b', 'b', 'b', 'b', 0x33};
  uint8_t INS7[8] = {0x00, 0x11, 'b', 'b', 'b', 'b', 0x22, 0x33};
  uint8_t INS8[8] = {0x00, 'b', 'b', 'b', 'b', 0x11, 0x22, 0x33};
  uint8_t INS9[8] = {'b', 'b', 'b', 'b', 0x00, 0x11, 0x22, 0x33};

  for (int i = 0; i < NumIter; i++) {
    uint8_t T[8] = {0x00, 0x11, 0x22, 0x33};
    size_t NewSize = (*MD.*M)(T, 4, 8);
    if (NewSize == 7 && !memcmp(INS0, T, 7)) FoundMask |= 1 << 0;
    if (NewSize == 7 && !memcmp(INS1, T, 7)) FoundMask |= 1 << 1;
    if (NewSize == 7 && !memcmp(INS2, T, 7)) FoundMask |= 1 << 2;
    if (NewSize == 7 && !memcmp(INS3, T, 7)) FoundMask |= 1 << 3;
    if (NewSize == 7 && !memcmp(INS4, T, 7)) FoundMask |= 1 << 4;

    if (NewSize == 8 && !memcmp(INS5, T, 8)) FoundMask |= 1 << 5;
    if (NewSize == 8 && !memcmp(INS6, T, 8)) FoundMask |= 1 << 6;
    if (NewSize == 8 && !memcmp(INS7, T, 8)) FoundMask |= 1 << 7;
    if (NewSize == 8 && !memcmp(INS8, T, 8)) FoundMask |= 1 << 8;
    if (NewSize == 8 && !memcmp(INS9, T, 8)) FoundMask |= 1 << 9;

  }
  EXPECT_EQ(FoundMask, (1 << 10) - 1);
}

TEST(FuzzerMutate, InsertRepeatedBytes1) {
  TestInsertRepeatedBytes(&MutationDispatcher::Mutate_InsertRepeatedBytes, 10000);
}
TEST(FuzzerMutate, InsertRepeatedBytes2) {
  TestInsertRepeatedBytes(&MutationDispatcher::Mutate, 300000);
}

void TestChangeByte(Mutator M, int NumIter) {
  std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
  fuzzer::EF = t.get();
  Random Rand(0);
  std::unique_ptr<MutationDispatcher> MD(new MutationDispatcher(Rand, {}));
  int FoundMask = 0;
  uint8_t CH0[8] = {0xF0, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
  uint8_t CH1[8] = {0x00, 0xF1, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
  uint8_t CH2[8] = {0x00, 0x11, 0xF2, 0x33, 0x44, 0x55, 0x66, 0x77};
  uint8_t CH3[8] = {0x00, 0x11, 0x22, 0xF3, 0x44, 0x55, 0x66, 0x77};
  uint8_t CH4[8] = {0x00, 0x11, 0x22, 0x33, 0xF4, 0x55, 0x66, 0x77};
  uint8_t CH5[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0xF5, 0x66, 0x77};
  uint8_t CH6[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0xF5, 0x77};
  uint8_t CH7[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0xF7};
  for (int i = 0; i < NumIter; i++) {
    uint8_t T[9] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
    size_t NewSize = (*MD.*M)(T, 8, 9);
    if (NewSize == 8 && !memcmp(CH0, T, 8)) FoundMask |= 1 << 0;
    if (NewSize == 8 && !memcmp(CH1, T, 8)) FoundMask |= 1 << 1;
    if (NewSize == 8 && !memcmp(CH2, T, 8)) FoundMask |= 1 << 2;
    if (NewSize == 8 && !memcmp(CH3, T, 8)) FoundMask |= 1 << 3;
    if (NewSize == 8 && !memcmp(CH4, T, 8)) FoundMask |= 1 << 4;
    if (NewSize == 8 && !memcmp(CH5, T, 8)) FoundMask |= 1 << 5;
    if (NewSize == 8 && !memcmp(CH6, T, 8)) FoundMask |= 1 << 6;
    if (NewSize == 8 && !memcmp(CH7, T, 8)) FoundMask |= 1 << 7;
  }
  EXPECT_EQ(FoundMask, 255);
}

TEST(FuzzerMutate, ChangeByte1) {
  TestChangeByte(&MutationDispatcher::Mutate_ChangeByte, 1 << 15);
}
TEST(FuzzerMutate, ChangeByte2) {
  TestChangeByte(&MutationDispatcher::Mutate, 1 << 17);
}

void TestChangeBit(Mutator M, int NumIter) {
  std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
  fuzzer::EF = t.get();
  Random Rand(0);
  std::unique_ptr<MutationDispatcher> MD(new MutationDispatcher(Rand, {}));
  int FoundMask = 0;
  uint8_t CH0[8] = {0x01, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
  uint8_t CH1[8] = {0x00, 0x13, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
  uint8_t CH2[8] = {0x00, 0x11, 0x02, 0x33, 0x44, 0x55, 0x66, 0x77};
  uint8_t CH3[8] = {0x00, 0x11, 0x22, 0x37, 0x44, 0x55, 0x66, 0x77};
  uint8_t CH4[8] = {0x00, 0x11, 0x22, 0x33, 0x54, 0x55, 0x66, 0x77};
  uint8_t CH5[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x54, 0x66, 0x77};
  uint8_t CH6[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x76, 0x77};
  uint8_t CH7[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0xF7};
  for (int i = 0; i < NumIter; i++) {
    uint8_t T[9] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
    size_t NewSize = (*MD.*M)(T, 8, 9);
    if (NewSize == 8 && !memcmp(CH0, T, 8)) FoundMask |= 1 << 0;
    if (NewSize == 8 && !memcmp(CH1, T, 8)) FoundMask |= 1 << 1;
    if (NewSize == 8 && !memcmp(CH2, T, 8)) FoundMask |= 1 << 2;
    if (NewSize == 8 && !memcmp(CH3, T, 8)) FoundMask |= 1 << 3;
    if (NewSize == 8 && !memcmp(CH4, T, 8)) FoundMask |= 1 << 4;
    if (NewSize == 8 && !memcmp(CH5, T, 8)) FoundMask |= 1 << 5;
    if (NewSize == 8 && !memcmp(CH6, T, 8)) FoundMask |= 1 << 6;
    if (NewSize == 8 && !memcmp(CH7, T, 8)) FoundMask |= 1 << 7;
  }
  EXPECT_EQ(FoundMask, 255);
}

TEST(FuzzerMutate, ChangeBit1) {
  TestChangeBit(&MutationDispatcher::Mutate_ChangeBit, 1 << 16);
}
TEST(FuzzerMutate, ChangeBit2) {
  TestChangeBit(&MutationDispatcher::Mutate, 1 << 18);
}

void TestShuffleBytes(Mutator M, int NumIter) {
  std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
  fuzzer::EF = t.get();
  Random Rand(0);
  std::unique_ptr<MutationDispatcher> MD(new MutationDispatcher(Rand, {}));
  int FoundMask = 0;
  uint8_t CH0[7] = {0x00, 0x22, 0x11, 0x33, 0x44, 0x55, 0x66};
  uint8_t CH1[7] = {0x11, 0x00, 0x33, 0x22, 0x44, 0x55, 0x66};
  uint8_t CH2[7] = {0x00, 0x33, 0x11, 0x22, 0x44, 0x55, 0x66};
  uint8_t CH3[7] = {0x00, 0x11, 0x22, 0x44, 0x55, 0x66, 0x33};
  uint8_t CH4[7] = {0x00, 0x11, 0x22, 0x33, 0x55, 0x44, 0x66};
  for (int i = 0; i < NumIter; i++) {
    uint8_t T[7] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66};
    size_t NewSize = (*MD.*M)(T, 7, 7);
    if (NewSize == 7 && !memcmp(CH0, T, 7)) FoundMask |= 1 << 0;
    if (NewSize == 7 && !memcmp(CH1, T, 7)) FoundMask |= 1 << 1;
    if (NewSize == 7 && !memcmp(CH2, T, 7)) FoundMask |= 1 << 2;
    if (NewSize == 7 && !memcmp(CH3, T, 7)) FoundMask |= 1 << 3;
    if (NewSize == 7 && !memcmp(CH4, T, 7)) FoundMask |= 1 << 4;
  }
  EXPECT_EQ(FoundMask, 31);
}

TEST(FuzzerMutate, ShuffleBytes1) {
  TestShuffleBytes(&MutationDispatcher::Mutate_ShuffleBytes, 1 << 17);
}
TEST(FuzzerMutate, ShuffleBytes2) {
  TestShuffleBytes(&MutationDispatcher::Mutate, 1 << 20);
}

void TestCopyPart(Mutator M, int NumIter) {
  std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
  fuzzer::EF = t.get();
  Random Rand(0);
  std::unique_ptr<MutationDispatcher> MD(new MutationDispatcher(Rand, {}));
  int FoundMask = 0;
  uint8_t CH0[7] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x00, 0x11};
  uint8_t CH1[7] = {0x55, 0x66, 0x22, 0x33, 0x44, 0x55, 0x66};
  uint8_t CH2[7] = {0x00, 0x55, 0x66, 0x33, 0x44, 0x55, 0x66};
  uint8_t CH3[7] = {0x00, 0x11, 0x22, 0x00, 0x11, 0x22, 0x66};
  uint8_t CH4[7] = {0x00, 0x11, 0x11, 0x22, 0x33, 0x55, 0x66};

  for (int i = 0; i < NumIter; i++) {
    uint8_t T[7] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66};
    size_t NewSize = (*MD.*M)(T, 7, 7);
    if (NewSize == 7 && !memcmp(CH0, T, 7)) FoundMask |= 1 << 0;
    if (NewSize == 7 && !memcmp(CH1, T, 7)) FoundMask |= 1 << 1;
    if (NewSize == 7 && !memcmp(CH2, T, 7)) FoundMask |= 1 << 2;
    if (NewSize == 7 && !memcmp(CH3, T, 7)) FoundMask |= 1 << 3;
    if (NewSize == 7 && !memcmp(CH4, T, 7)) FoundMask |= 1 << 4;
  }

  uint8_t CH5[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x00, 0x11, 0x22};
  uint8_t CH6[8] = {0x22, 0x33, 0x44, 0x00, 0x11, 0x22, 0x33, 0x44};
  uint8_t CH7[8] = {0x00, 0x11, 0x22, 0x00, 0x11, 0x22, 0x33, 0x44};
  uint8_t CH8[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x22, 0x33, 0x44};
  uint8_t CH9[8] = {0x00, 0x11, 0x22, 0x22, 0x33, 0x44, 0x33, 0x44};

  for (int i = 0; i < NumIter; i++) {
    uint8_t T[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
    size_t NewSize = (*MD.*M)(T, 5, 8);
    if (NewSize == 8 && !memcmp(CH5, T, 8)) FoundMask |= 1 << 5;
    if (NewSize == 8 && !memcmp(CH6, T, 8)) FoundMask |= 1 << 6;
    if (NewSize == 8 && !memcmp(CH7, T, 8)) FoundMask |= 1 << 7;
    if (NewSize == 8 && !memcmp(CH8, T, 8)) FoundMask |= 1 << 8;
    if (NewSize == 8 && !memcmp(CH9, T, 8)) FoundMask |= 1 << 9;
  }

  EXPECT_EQ(FoundMask, 1023);
}

TEST(FuzzerMutate, CopyPart1) {
  TestCopyPart(&MutationDispatcher::Mutate_CopyPart, 1 << 10);
}
TEST(FuzzerMutate, CopyPart2) {
  TestCopyPart(&MutationDispatcher::Mutate, 1 << 13);
}
TEST(FuzzerMutate, CopyPartNoInsertAtMaxSize) {
  // This (non exhaustively) tests if `Mutate_CopyPart` tries to perform an
  // insert on an input of size `MaxSize`.  Performing an insert in this case
  // will lead to the mutation failing.
  std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
  fuzzer::EF = t.get();
  Random Rand(0);
  std::unique_ptr<MutationDispatcher> MD(new MutationDispatcher(Rand, {}));
  uint8_t Data[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x00, 0x11, 0x22};
  size_t MaxSize = sizeof(Data);
  for (int count = 0; count < (1 << 18); ++count) {
    size_t NewSize = MD->Mutate_CopyPart(Data, MaxSize, MaxSize);
    ASSERT_EQ(NewSize, MaxSize);
  }
}

void TestAddWordFromDictionary(Mutator M, int NumIter) {
  std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
  fuzzer::EF = t.get();
  Random Rand(0);
  std::unique_ptr<MutationDispatcher> MD(new MutationDispatcher(Rand, {}));
  uint8_t Word1[4] = {0xAA, 0xBB, 0xCC, 0xDD};
  uint8_t Word2[3] = {0xFF, 0xEE, 0xEF};
  MD->AddWordToManualDictionary(Word(Word1, sizeof(Word1)));
  MD->AddWordToManualDictionary(Word(Word2, sizeof(Word2)));
  int FoundMask = 0;
  uint8_t CH0[7] = {0x00, 0x11, 0x22, 0xAA, 0xBB, 0xCC, 0xDD};
  uint8_t CH1[7] = {0x00, 0x11, 0xAA, 0xBB, 0xCC, 0xDD, 0x22};
  uint8_t CH2[7] = {0x00, 0xAA, 0xBB, 0xCC, 0xDD, 0x11, 0x22};
  uint8_t CH3[7] = {0xAA, 0xBB, 0xCC, 0xDD, 0x00, 0x11, 0x22};
  uint8_t CH4[6] = {0x00, 0x11, 0x22, 0xFF, 0xEE, 0xEF};
  uint8_t CH5[6] = {0x00, 0x11, 0xFF, 0xEE, 0xEF, 0x22};
  uint8_t CH6[6] = {0x00, 0xFF, 0xEE, 0xEF, 0x11, 0x22};
  uint8_t CH7[6] = {0xFF, 0xEE, 0xEF, 0x00, 0x11, 0x22};
  for (int i = 0; i < NumIter; i++) {
    uint8_t T[7] = {0x00, 0x11, 0x22};
    size_t NewSize = (*MD.*M)(T, 3, 7);
    if (NewSize == 7 && !memcmp(CH0, T, 7)) FoundMask |= 1 << 0;
    if (NewSize == 7 && !memcmp(CH1, T, 7)) FoundMask |= 1 << 1;
    if (NewSize == 7 && !memcmp(CH2, T, 7)) FoundMask |= 1 << 2;
    if (NewSize == 7 && !memcmp(CH3, T, 7)) FoundMask |= 1 << 3;
    if (NewSize == 6 && !memcmp(CH4, T, 6)) FoundMask |= 1 << 4;
    if (NewSize == 6 && !memcmp(CH5, T, 6)) FoundMask |= 1 << 5;
    if (NewSize == 6 && !memcmp(CH6, T, 6)) FoundMask |= 1 << 6;
    if (NewSize == 6 && !memcmp(CH7, T, 6)) FoundMask |= 1 << 7;
  }
  EXPECT_EQ(FoundMask, 255);
}

TEST(FuzzerMutate, AddWordFromDictionary1) {
  TestAddWordFromDictionary(
      &MutationDispatcher::Mutate_AddWordFromManualDictionary, 1 << 15);
}

TEST(FuzzerMutate, AddWordFromDictionary2) {
  TestAddWordFromDictionary(&MutationDispatcher::Mutate, 1 << 15);
}

void TestChangeASCIIInteger(Mutator M, int NumIter) {
  std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
  fuzzer::EF = t.get();
  Random Rand(0);
  std::unique_ptr<MutationDispatcher> MD(new MutationDispatcher(Rand, {}));

  uint8_t CH0[8] = {'1', '2', '3', '4', '5', '6', '7', '7'};
  uint8_t CH1[8] = {'1', '2', '3', '4', '5', '6', '7', '9'};
  uint8_t CH2[8] = {'2', '4', '6', '9', '1', '3', '5', '6'};
  uint8_t CH3[8] = {'0', '6', '1', '7', '2', '8', '3', '9'};
  int FoundMask = 0;
  for (int i = 0; i < NumIter; i++) {
    uint8_t T[8] = {'1', '2', '3', '4', '5', '6', '7', '8'};
    size_t NewSize = (*MD.*M)(T, 8, 8);
    /**/ if (NewSize == 8 && !memcmp(CH0, T, 8)) FoundMask |= 1 << 0;
    else if (NewSize == 8 && !memcmp(CH1, T, 8)) FoundMask |= 1 << 1;
    else if (NewSize == 8 && !memcmp(CH2, T, 8)) FoundMask |= 1 << 2;
    else if (NewSize == 8 && !memcmp(CH3, T, 8)) FoundMask |= 1 << 3;
    else if (NewSize == 8)                       FoundMask |= 1 << 4;
  }
  EXPECT_EQ(FoundMask, 31);
}

TEST(FuzzerMutate, ChangeASCIIInteger1) {
  TestChangeASCIIInteger(&MutationDispatcher::Mutate_ChangeASCIIInteger,
                         1 << 15);
}

TEST(FuzzerMutate, ChangeASCIIInteger2) {
  TestChangeASCIIInteger(&MutationDispatcher::Mutate, 1 << 15);
}

void TestChangeBinaryInteger(Mutator M, int NumIter) {
  std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
  fuzzer::EF = t.get();
  Random Rand(0);
  std::unique_ptr<MutationDispatcher> MD(new MutationDispatcher(Rand, {}));

  uint8_t CH0[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x79};
  uint8_t CH1[8] = {0x00, 0x11, 0x22, 0x31, 0x44, 0x55, 0x66, 0x77};
  uint8_t CH2[8] = {0xff, 0x10, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
  uint8_t CH3[8] = {0x00, 0x11, 0x2a, 0x33, 0x44, 0x55, 0x66, 0x77};
  uint8_t CH4[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x4f, 0x66, 0x77};
  uint8_t CH5[8] = {0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99, 0x88};
  uint8_t CH6[8] = {0x00, 0x11, 0x22, 0x00, 0x00, 0x00, 0x08, 0x77}; // Size
  uint8_t CH7[8] = {0x00, 0x08, 0x00, 0x33, 0x44, 0x55, 0x66, 0x77}; // Sw(Size)

  int FoundMask = 0;
  for (int i = 0; i < NumIter; i++) {
    uint8_t T[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
    size_t NewSize = (*MD.*M)(T, 8, 8);
    /**/ if (NewSize == 8 && !memcmp(CH0, T, 8)) FoundMask |= 1 << 0;
    else if (NewSize == 8 && !memcmp(CH1, T, 8)) FoundMask |= 1 << 1;
    else if (NewSize == 8 && !memcmp(CH2, T, 8)) FoundMask |= 1 << 2;
    else if (NewSize == 8 && !memcmp(CH3, T, 8)) FoundMask |= 1 << 3;
    else if (NewSize == 8 && !memcmp(CH4, T, 8)) FoundMask |= 1 << 4;
    else if (NewSize == 8 && !memcmp(CH5, T, 8)) FoundMask |= 1 << 5;
    else if (NewSize == 8 && !memcmp(CH6, T, 8)) FoundMask |= 1 << 6;
    else if (NewSize == 8 && !memcmp(CH7, T, 8)) FoundMask |= 1 << 7;
  }
  EXPECT_EQ(FoundMask, 255);
}

TEST(FuzzerMutate, ChangeBinaryInteger1) {
  TestChangeBinaryInteger(&MutationDispatcher::Mutate_ChangeBinaryInteger,
                         1 << 12);
}

TEST(FuzzerMutate, ChangeBinaryInteger2) {
  TestChangeBinaryInteger(&MutationDispatcher::Mutate, 1 << 15);
}


TEST(FuzzerDictionary, ParseOneDictionaryEntry) {
  Unit U;
  EXPECT_FALSE(ParseOneDictionaryEntry("", &U));
  EXPECT_FALSE(ParseOneDictionaryEntry(" ", &U));
  EXPECT_FALSE(ParseOneDictionaryEntry("\t  ", &U));
  EXPECT_FALSE(ParseOneDictionaryEntry("  \" ", &U));
  EXPECT_FALSE(ParseOneDictionaryEntry("  zz\" ", &U));
  EXPECT_FALSE(ParseOneDictionaryEntry("  \"zz ", &U));
  EXPECT_FALSE(ParseOneDictionaryEntry("  \"\" ", &U));
  EXPECT_TRUE(ParseOneDictionaryEntry("\"a\"", &U));
  EXPECT_EQ(U, Unit({'a'}));
  EXPECT_TRUE(ParseOneDictionaryEntry("\"abc\"", &U));
  EXPECT_EQ(U, Unit({'a', 'b', 'c'}));
  EXPECT_TRUE(ParseOneDictionaryEntry("abc=\"abc\"", &U));
  EXPECT_EQ(U, Unit({'a', 'b', 'c'}));
  EXPECT_FALSE(ParseOneDictionaryEntry("\"\\\"", &U));
  EXPECT_TRUE(ParseOneDictionaryEntry("\"\\\\\"", &U));
  EXPECT_EQ(U, Unit({'\\'}));
  EXPECT_TRUE(ParseOneDictionaryEntry("\"\\xAB\"", &U));
  EXPECT_EQ(U, Unit({0xAB}));
  EXPECT_TRUE(ParseOneDictionaryEntry("\"\\xABz\\xDE\"", &U));
  EXPECT_EQ(U, Unit({0xAB, 'z', 0xDE}));
  EXPECT_TRUE(ParseOneDictionaryEntry("\"#\"", &U));
  EXPECT_EQ(U, Unit({'#'}));
  EXPECT_TRUE(ParseOneDictionaryEntry("\"\\\"\"", &U));
  EXPECT_EQ(U, Unit({'"'}));
}

TEST(FuzzerDictionary, ParseDictionaryFile) {
  Vector<Unit> Units;
  EXPECT_FALSE(ParseDictionaryFile("zzz\n", &Units));
  EXPECT_FALSE(ParseDictionaryFile("", &Units));
  EXPECT_TRUE(ParseDictionaryFile("\n", &Units));
  EXPECT_EQ(Units.size(), 0U);
  EXPECT_TRUE(ParseDictionaryFile("#zzzz a b c d\n", &Units));
  EXPECT_EQ(Units.size(), 0U);
  EXPECT_TRUE(ParseDictionaryFile(" #zzzz\n", &Units));
  EXPECT_EQ(Units.size(), 0U);
  EXPECT_TRUE(ParseDictionaryFile("  #zzzz\n", &Units));
  EXPECT_EQ(Units.size(), 0U);
  EXPECT_TRUE(ParseDictionaryFile("  #zzzz\naaa=\"aa\"", &Units));
  EXPECT_EQ(Units, Vector<Unit>({Unit({'a', 'a'})}));
  EXPECT_TRUE(
      ParseDictionaryFile("  #zzzz\naaa=\"aa\"\n\nabc=\"abc\"", &Units));
  EXPECT_EQ(Units,
            Vector<Unit>({Unit({'a', 'a'}), Unit({'a', 'b', 'c'})}));
}

TEST(FuzzerUtil, Base64) {
  EXPECT_EQ("", Base64({}));
  EXPECT_EQ("YQ==", Base64({'a'}));
  EXPECT_EQ("eA==", Base64({'x'}));
  EXPECT_EQ("YWI=", Base64({'a', 'b'}));
  EXPECT_EQ("eHk=", Base64({'x', 'y'}));
  EXPECT_EQ("YWJj", Base64({'a', 'b', 'c'}));
  EXPECT_EQ("eHl6", Base64({'x', 'y', 'z'}));
  EXPECT_EQ("YWJjeA==", Base64({'a', 'b', 'c', 'x'}));
  EXPECT_EQ("YWJjeHk=", Base64({'a', 'b', 'c', 'x', 'y'}));
  EXPECT_EQ("YWJjeHl6", Base64({'a', 'b', 'c', 'x', 'y', 'z'}));
}

TEST(Corpus, Distribution) {
  DataFlowTrace DFT;
  Random Rand(0);
  std::unique_ptr<InputCorpus> C(new InputCorpus(""));
  size_t N = 10;
  size_t TriesPerUnit = 1<<16;
  for (size_t i = 0; i < N; i++)
    C->AddToCorpus(Unit{static_cast<uint8_t>(i)}, 1, false, false, {}, DFT,
                   nullptr);

  Vector<size_t> Hist(N);
  for (size_t i = 0; i < N * TriesPerUnit; i++) {
    Hist[C->ChooseUnitIdxToMutate(Rand)]++;
  }
  for (size_t i = 0; i < N; i++) {
    // A weak sanity check that every unit gets invoked.
    EXPECT_GT(Hist[i], TriesPerUnit / N / 3);
  }
}

TEST(Merge, Bad) {
  const char *kInvalidInputs[] = {
    "",
    "x",
    "3\nx",
    "2\n3",
    "2\n2",
    "2\n2\nA\n",
    "2\n2\nA\nB\nC\n",
    "0\n0\n",
    "1\n1\nA\nFT 0",
    "1\n1\nA\nSTARTED 1",
  };
  Merger M;
  for (auto S : kInvalidInputs) {
    // fprintf(stderr, "TESTING:\n%s\n", S);
    EXPECT_FALSE(M.Parse(S, false));
  }
}

void EQ(const Vector<uint32_t> &A, const Vector<uint32_t> &B) {
  EXPECT_EQ(A, B);
}

void EQ(const Vector<std::string> &A, const Vector<std::string> &B) {
  Set<std::string> a(A.begin(), A.end());
  Set<std::string> b(B.begin(), B.end());
  EXPECT_EQ(a, b);
}

static void Merge(const std::string &Input,
                  const Vector<std::string> Result,
                  size_t NumNewFeatures) {
  Merger M;
  Vector<std::string> NewFiles;
  Set<uint32_t> NewFeatures, NewCov;
  EXPECT_TRUE(M.Parse(Input, true));
  EXPECT_EQ(NumNewFeatures, M.Merge({}, &NewFeatures, {}, &NewCov, &NewFiles));
  EQ(NewFiles, Result);
}

TEST(Merge, Good) {
  Merger M;

  EXPECT_TRUE(M.Parse("1\n0\nAA\n", false));
  EXPECT_EQ(M.Files.size(), 1U);
  EXPECT_EQ(M.NumFilesInFirstCorpus, 0U);
  EXPECT_EQ(M.Files[0].Name, "AA");
  EXPECT_TRUE(M.LastFailure.empty());
  EXPECT_EQ(M.FirstNotProcessedFile, 0U);

  EXPECT_TRUE(M.Parse("2\n1\nAA\nBB\nSTARTED 0 42\n", false));
  EXPECT_EQ(M.Files.size(), 2U);
  EXPECT_EQ(M.NumFilesInFirstCorpus, 1U);
  EXPECT_EQ(M.Files[0].Name, "AA");
  EXPECT_EQ(M.Files[1].Name, "BB");
  EXPECT_EQ(M.LastFailure, "AA");
  EXPECT_EQ(M.FirstNotProcessedFile, 1U);

  EXPECT_TRUE(M.Parse("3\n1\nAA\nBB\nC\n"
                        "STARTED 0 1000\n"
                        "FT 0 1 2 3\n"
                        "STARTED 1 1001\n"
                        "FT 1 4 5 6 \n"
                        "STARTED 2 1002\n"
                        "", true));
  EXPECT_EQ(M.Files.size(), 3U);
  EXPECT_EQ(M.NumFilesInFirstCorpus, 1U);
  EXPECT_EQ(M.Files[0].Name, "AA");
  EXPECT_EQ(M.Files[0].Size, 1000U);
  EXPECT_EQ(M.Files[1].Name, "BB");
  EXPECT_EQ(M.Files[1].Size, 1001U);
  EXPECT_EQ(M.Files[2].Name, "C");
  EXPECT_EQ(M.Files[2].Size, 1002U);
  EXPECT_EQ(M.LastFailure, "C");
  EXPECT_EQ(M.FirstNotProcessedFile, 3U);
  EQ(M.Files[0].Features, {1, 2, 3});
  EQ(M.Files[1].Features, {4, 5, 6});


  Vector<std::string> NewFiles;
  Set<uint32_t> NewFeatures, NewCov;

  EXPECT_TRUE(M.Parse("3\n2\nAA\nBB\nC\n"
                        "STARTED 0 1000\nFT 0 1 2 3\n"
                        "STARTED 1 1001\nFT 1 4 5 6 \n"
                        "STARTED 2 1002\nFT 2 6 1 3 \n"
                        "", true));
  EXPECT_EQ(M.Files.size(), 3U);
  EXPECT_EQ(M.NumFilesInFirstCorpus, 2U);
  EXPECT_TRUE(M.LastFailure.empty());
  EXPECT_EQ(M.FirstNotProcessedFile, 3U);
  EQ(M.Files[0].Features, {1, 2, 3});
  EQ(M.Files[1].Features, {4, 5, 6});
  EQ(M.Files[2].Features, {1, 3, 6});
  EXPECT_EQ(0U, M.Merge({}, &NewFeatures, {}, &NewCov, &NewFiles));
  EQ(NewFiles, {});

  EXPECT_TRUE(M.Parse("3\n1\nA\nB\nC\n"
                        "STARTED 0 1000\nFT 0 1 2 3\n"
                        "STARTED 1 1001\nFT 1 4 5 6 \n"
                        "STARTED 2 1002\nFT 2 6 1 3\n"
                        "", true));
  EQ(M.Files[0].Features, {1, 2, 3});
  EQ(M.Files[1].Features, {4, 5, 6});
  EQ(M.Files[2].Features, {1, 3, 6});
  EXPECT_EQ(3U, M.Merge({}, &NewFeatures, {}, &NewCov, &NewFiles));
  EQ(NewFiles, {"B"});

  // Same as the above, but with InitialFeatures.
  EXPECT_TRUE(M.Parse("2\n0\nB\nC\n"
                        "STARTED 0 1001\nFT 0 4 5 6 \n"
                        "STARTED 1 1002\nFT 1 6 1 3\n"
                        "", true));
  EQ(M.Files[0].Features, {4, 5, 6});
  EQ(M.Files[1].Features, {1, 3, 6});
  Set<uint32_t> InitialFeatures;
  InitialFeatures.insert(1);
  InitialFeatures.insert(2);
  InitialFeatures.insert(3);
  EXPECT_EQ(3U, M.Merge(InitialFeatures, &NewFeatures, {}, &NewCov, &NewFiles));
  EQ(NewFiles, {"B"});
}

TEST(Merge, Merge) {

  Merge("3\n1\nA\nB\nC\n"
        "STARTED 0 1000\nFT 0 1 2 3\n"
        "STARTED 1 1001\nFT 1 4 5 6 \n"
        "STARTED 2 1002\nFT 2 6 1 3 \n",
        {"B"}, 3);

  Merge("3\n0\nA\nB\nC\n"
        "STARTED 0 2000\nFT 0 1 2 3\n"
        "STARTED 1 1001\nFT 1 4 5 6 \n"
        "STARTED 2 1002\nFT 2 6 1 3 \n",
        {"A", "B", "C"}, 6);

  Merge("4\n0\nA\nB\nC\nD\n"
        "STARTED 0 2000\nFT 0 1 2 3\n"
        "STARTED 1 1101\nFT 1 4 5 6 \n"
        "STARTED 2 1102\nFT 2 6 1 3 100 \n"
        "STARTED 3 1000\nFT 3 1  \n",
        {"A", "B", "C", "D"}, 7);

  Merge("4\n1\nA\nB\nC\nD\n"
        "STARTED 0 2000\nFT 0 4 5 6 7 8\n"
        "STARTED 1 1100\nFT 1 1 2 3 \n"
        "STARTED 2 1100\nFT 2 2 3 \n"
        "STARTED 3 1000\nFT 3 1  \n",
        {"B", "D"}, 3);
}

TEST(DFT, BlockCoverage) {
  BlockCoverage Cov;
  // Assuming C0 has 5 instrumented blocks,
  // C1: 7 blocks, C2: 4, C3: 9, C4 never covered, C5: 15,

  // Add C0
  EXPECT_TRUE(Cov.AppendCoverage("C0 5\n"));
  EXPECT_EQ(Cov.GetCounter(0, 0), 1U);
  EXPECT_EQ(Cov.GetCounter(0, 1), 0U);  // not seen this BB yet.
  EXPECT_EQ(Cov.GetCounter(0, 5), 0U);  // BB ID out of bounds.
  EXPECT_EQ(Cov.GetCounter(1, 0), 0U);  // not seen this function yet.

  EXPECT_EQ(Cov.GetNumberOfBlocks(0), 5U);
  EXPECT_EQ(Cov.GetNumberOfCoveredBlocks(0), 1U);
  EXPECT_EQ(Cov.GetNumberOfBlocks(1), 0U);

  // Various errors.
  EXPECT_FALSE(Cov.AppendCoverage("C0\n"));  // No total number.
  EXPECT_FALSE(Cov.AppendCoverage("C0 7\n"));  // No total number.
  EXPECT_FALSE(Cov.AppendCoverage("CZ\n"));  // Wrong function number.
  EXPECT_FALSE(Cov.AppendCoverage("C1 7 7"));  // BB ID is too big.
  EXPECT_FALSE(Cov.AppendCoverage("C1 100 7")); // BB ID is too big.

  // Add C0 more times.
  EXPECT_TRUE(Cov.AppendCoverage("C0 5\n"));
  EXPECT_EQ(Cov.GetCounter(0, 0), 2U);
  EXPECT_TRUE(Cov.AppendCoverage("C0 1 2 5\n"));
  EXPECT_EQ(Cov.GetCounter(0, 0), 3U);
  EXPECT_EQ(Cov.GetCounter(0, 1), 1U);
  EXPECT_EQ(Cov.GetCounter(0, 2), 1U);
  EXPECT_EQ(Cov.GetCounter(0, 3), 0U);
  EXPECT_EQ(Cov.GetCounter(0, 4), 0U);
  EXPECT_EQ(Cov.GetNumberOfCoveredBlocks(0), 3U);
  EXPECT_TRUE(Cov.AppendCoverage("C0 1 3 4 5\n"));
  EXPECT_EQ(Cov.GetCounter(0, 0), 4U);
  EXPECT_EQ(Cov.GetCounter(0, 1), 2U);
  EXPECT_EQ(Cov.GetCounter(0, 2), 1U);
  EXPECT_EQ(Cov.GetCounter(0, 3), 1U);
  EXPECT_EQ(Cov.GetCounter(0, 4), 1U);
  EXPECT_EQ(Cov.GetNumberOfCoveredBlocks(0), 5U);

  EXPECT_TRUE(Cov.AppendCoverage("C1 7\nC2 4\nC3 9\nC5 15\nC0 5\n"));
  EXPECT_EQ(Cov.GetCounter(0, 0), 5U);
  EXPECT_EQ(Cov.GetCounter(1, 0), 1U);
  EXPECT_EQ(Cov.GetCounter(2, 0), 1U);
  EXPECT_EQ(Cov.GetCounter(3, 0), 1U);
  EXPECT_EQ(Cov.GetCounter(4, 0), 0U);
  EXPECT_EQ(Cov.GetCounter(5, 0), 1U);

  EXPECT_TRUE(Cov.AppendCoverage("C3 4 5 9\nC5 11 12 15"));
  EXPECT_EQ(Cov.GetCounter(0, 0), 5U);
  EXPECT_EQ(Cov.GetCounter(1, 0), 1U);
  EXPECT_EQ(Cov.GetCounter(2, 0), 1U);
  EXPECT_EQ(Cov.GetCounter(3, 0), 2U);
  EXPECT_EQ(Cov.GetCounter(3, 4), 1U);
  EXPECT_EQ(Cov.GetCounter(3, 5), 1U);
  EXPECT_EQ(Cov.GetCounter(3, 6), 0U);
  EXPECT_EQ(Cov.GetCounter(4, 0), 0U);
  EXPECT_EQ(Cov.GetCounter(5, 0), 2U);
  EXPECT_EQ(Cov.GetCounter(5, 10), 0U);
  EXPECT_EQ(Cov.GetCounter(5, 11), 1U);
  EXPECT_EQ(Cov.GetCounter(5, 12), 1U);
}

TEST(DFT, FunctionWeights) {
  BlockCoverage Cov;
  // unused function gets zero weight.
  EXPECT_TRUE(Cov.AppendCoverage("C0 5\n"));
  auto Weights = Cov.FunctionWeights(2);
  EXPECT_GT(Weights[0], 0.);
  EXPECT_EQ(Weights[1], 0.);

  // Less frequently used function gets less weight.
  Cov.clear();
  EXPECT_TRUE(Cov.AppendCoverage("C0 5\nC1 5\nC1 5\n"));
  Weights = Cov.FunctionWeights(2);
  EXPECT_GT(Weights[0], Weights[1]);

  // A function with more uncovered bclocks gets more weight.
  Cov.clear();
  EXPECT_TRUE(Cov.AppendCoverage("C0 1 2 3 5\nC1 2 4\n"));
  Weights = Cov.FunctionWeights(2);
  EXPECT_GT(Weights[1], Weights[0]);
}


TEST(Fuzzer, ForEachNonZeroByte) {
  const size_t N = 64;
  alignas(64) uint8_t Ar[N + 8] = {
    0, 0, 0, 0, 0, 0, 0, 0,
    1, 2, 0, 0, 0, 0, 0, 0,
    0, 0, 3, 0, 4, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 5, 0, 6, 0, 0,
    0, 0, 0, 0, 0, 0, 7, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 8,
    9, 9, 9, 9, 9, 9, 9, 9,
  };
  typedef Vector<std::pair<size_t, uint8_t> > Vec;
  Vec Res, Expected;
  auto CB = [&](size_t FirstFeature, size_t Idx, uint8_t V) {
    Res.push_back({FirstFeature + Idx, V});
  };
  ForEachNonZeroByte(Ar, Ar + N, 100, CB);
  Expected = {{108, 1}, {109, 2}, {118, 3}, {120, 4},
              {135, 5}, {137, 6}, {146, 7}, {163, 8}};
  EXPECT_EQ(Res, Expected);

  Res.clear();
  ForEachNonZeroByte(Ar + 9, Ar + N, 109, CB);
  Expected = {          {109, 2}, {118, 3}, {120, 4},
              {135, 5}, {137, 6}, {146, 7}, {163, 8}};
  EXPECT_EQ(Res, Expected);

  Res.clear();
  ForEachNonZeroByte(Ar + 9, Ar + N - 9, 109, CB);
  Expected = {          {109, 2}, {118, 3}, {120, 4},
              {135, 5}, {137, 6}, {146, 7}};
  EXPECT_EQ(Res, Expected);
}

// FuzzerCommand unit tests. The arguments in the two helper methods below must
// match.
static void makeCommandArgs(Vector<std::string> *ArgsToAdd) {
  assert(ArgsToAdd);
  ArgsToAdd->clear();
  ArgsToAdd->push_back("foo");
  ArgsToAdd->push_back("-bar=baz");
  ArgsToAdd->push_back("qux");
  ArgsToAdd->push_back(Command::ignoreRemainingArgs());
  ArgsToAdd->push_back("quux");
  ArgsToAdd->push_back("-grault=garply");
}

static std::string makeCmdLine(const char *separator, const char *suffix) {
  std::string CmdLine("foo -bar=baz qux ");
  if (strlen(separator) != 0) {
    CmdLine += separator;
    CmdLine += " ";
  }
  CmdLine += Command::ignoreRemainingArgs();
  CmdLine += " quux -grault=garply";
  if (strlen(suffix) != 0) {
    CmdLine += " ";
    CmdLine += suffix;
  }
  return CmdLine;
}

TEST(FuzzerCommand, Create) {
  std::string CmdLine;

  // Default constructor
  Command DefaultCmd;

  CmdLine = DefaultCmd.toString();
  EXPECT_EQ(CmdLine, "");

  // Explicit constructor
  Vector<std::string> ArgsToAdd;
  makeCommandArgs(&ArgsToAdd);
  Command InitializedCmd(ArgsToAdd);

  CmdLine = InitializedCmd.toString();
  EXPECT_EQ(CmdLine, makeCmdLine("", ""));

  // Compare each argument
  auto InitializedArgs = InitializedCmd.getArguments();
  auto i = ArgsToAdd.begin();
  auto j = InitializedArgs.begin();
  while (i != ArgsToAdd.end() && j != InitializedArgs.end()) {
    EXPECT_EQ(*i++, *j++);
  }
  EXPECT_EQ(i, ArgsToAdd.end());
  EXPECT_EQ(j, InitializedArgs.end());

  // Copy constructor
  Command CopiedCmd(InitializedCmd);

  CmdLine = CopiedCmd.toString();
  EXPECT_EQ(CmdLine, makeCmdLine("", ""));

  // Assignment operator
  Command AssignedCmd;
  AssignedCmd = CopiedCmd;

  CmdLine = AssignedCmd.toString();
  EXPECT_EQ(CmdLine, makeCmdLine("", ""));
}

TEST(FuzzerCommand, ModifyArguments) {
  Vector<std::string> ArgsToAdd;
  makeCommandArgs(&ArgsToAdd);
  Command Cmd;
  std::string CmdLine;

  Cmd.addArguments(ArgsToAdd);
  CmdLine = Cmd.toString();
  EXPECT_EQ(CmdLine, makeCmdLine("", ""));

  Cmd.addArgument("waldo");
  EXPECT_TRUE(Cmd.hasArgument("waldo"));

  CmdLine = Cmd.toString();
  EXPECT_EQ(CmdLine, makeCmdLine("waldo", ""));

  Cmd.removeArgument("waldo");
  EXPECT_FALSE(Cmd.hasArgument("waldo"));

  CmdLine = Cmd.toString();
  EXPECT_EQ(CmdLine, makeCmdLine("", ""));
}

TEST(FuzzerCommand, ModifyFlags) {
  Vector<std::string> ArgsToAdd;
  makeCommandArgs(&ArgsToAdd);
  Command Cmd(ArgsToAdd);
  std::string Value, CmdLine;
  ASSERT_FALSE(Cmd.hasFlag("fred"));

  Value = Cmd.getFlagValue("fred");
  EXPECT_EQ(Value, "");

  CmdLine = Cmd.toString();
  EXPECT_EQ(CmdLine, makeCmdLine("", ""));

  Cmd.addFlag("fred", "plugh");
  EXPECT_TRUE(Cmd.hasFlag("fred"));

  Value = Cmd.getFlagValue("fred");
  EXPECT_EQ(Value, "plugh");

  CmdLine = Cmd.toString();
  EXPECT_EQ(CmdLine, makeCmdLine("-fred=plugh", ""));

  Cmd.removeFlag("fred");
  EXPECT_FALSE(Cmd.hasFlag("fred"));

  Value = Cmd.getFlagValue("fred");
  EXPECT_EQ(Value, "");

  CmdLine = Cmd.toString();
  EXPECT_EQ(CmdLine, makeCmdLine("", ""));
}

TEST(FuzzerCommand, SetOutput) {
  Vector<std::string> ArgsToAdd;
  makeCommandArgs(&ArgsToAdd);
  Command Cmd(ArgsToAdd);
  std::string CmdLine;
  ASSERT_FALSE(Cmd.hasOutputFile());
  ASSERT_FALSE(Cmd.isOutAndErrCombined());

  Cmd.combineOutAndErr(true);
  EXPECT_TRUE(Cmd.isOutAndErrCombined());

  CmdLine = Cmd.toString();
  EXPECT_EQ(CmdLine, makeCmdLine("", "2>&1"));

  Cmd.combineOutAndErr(false);
  EXPECT_FALSE(Cmd.isOutAndErrCombined());

  Cmd.setOutputFile("xyzzy");
  EXPECT_TRUE(Cmd.hasOutputFile());

  CmdLine = Cmd.toString();
  EXPECT_EQ(CmdLine, makeCmdLine("", ">xyzzy"));

  Cmd.setOutputFile("thud");
  EXPECT_TRUE(Cmd.hasOutputFile());

  CmdLine = Cmd.toString();
  EXPECT_EQ(CmdLine, makeCmdLine("", ">thud"));

  Cmd.combineOutAndErr();
  EXPECT_TRUE(Cmd.isOutAndErrCombined());

  CmdLine = Cmd.toString();
  EXPECT_EQ(CmdLine, makeCmdLine("", ">thud 2>&1"));
}

int main(int argc, char **argv) {
  testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}