mutagen/MutagenDictionary.h

//===- MutagenDictionary.h - Internal header for the mutagen ----*- C++ -* ===//
//
// 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
//
//===----------------------------------------------------------------------===//
// mutagen::Dictionary
//===----------------------------------------------------------------------===//

#ifndef LLVM_FUZZER_MUTAGEN_DICTIONARY_H
#define LLVM_FUZZER_MUTAGEN_DICTIONARY_H

#include "FuzzerDefs.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <limits>

namespace mutagen {
namespace {

using fuzzer::Word;

} // namespace

class DictionaryEntry {
public:
  DictionaryEntry() {}
  DictionaryEntry(Word W) : W(W) {}
  DictionaryEntry(Word W, size_t PositionHint)
      : W(W), PositionHint(PositionHint) {}
  const Word &GetW() const { return W; }

  bool HasPositionHint() const {
    return PositionHint != std::numeric_limits<size_t>::max();
  }
  size_t GetPositionHint() const {
    assert(HasPositionHint());
    return PositionHint;
  }
  void IncUseCount() { UseCount++; }
  void IncSuccessCount() { SuccessCount++; }
  size_t GetUseCount() const { return UseCount; }
  size_t GetSuccessCount() const { return SuccessCount; }

private:
  Word W;
  size_t PositionHint = std::numeric_limits<size_t>::max();
  size_t UseCount = 0;
  size_t SuccessCount = 0;
};

class Dictionary {
public:
  static const size_t kMaxDictSize = 1 << 14;

  bool ContainsWord(const Word &W) const {
    return std::any_of(begin(), end(), [&](const DictionaryEntry &DE) {
      return DE.GetW() == W;
    });
  }
  const DictionaryEntry *begin() const { return &DE[0]; }
  const DictionaryEntry *end() const { return begin() + Size; }
  DictionaryEntry &operator[](size_t Idx) {
    assert(Idx < Size);
    return DE[Idx];
  }
  void push_back(DictionaryEntry DE) {
    if (Size < kMaxDictSize)
      this->DE[Size++] = DE;
  }
  void clear() { Size = 0; }
  bool empty() const { return Size == 0; }
  size_t size() const { return Size; }

private:
  DictionaryEntry DE[kMaxDictSize];
  size_t Size = 0;
};

} // namespace mutagen

#endif // LLVM_FUZZER_MUTAGEN_DICTIONARY_H