llvm/compiler-rt/lib/fuzzer/FuzzerTracePC.h

//===- FuzzerTracePC.h - Internal header for the Fuzzer ---------*- 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
//
//===----------------------------------------------------------------------===//
// fuzzer::TracePC
//===----------------------------------------------------------------------===//

#ifndef LLVM_FUZZER_TRACE_PC
#define LLVM_FUZZER_TRACE_PC

#include "FuzzerDefs.h"
#include "FuzzerDictionary.h"
#include "FuzzerValueBitMap.h"

#include <set>
#include <unordered_map>

namespace fuzzer {

// TableOfRecentCompares (TORC) remembers the most recently performed
// comparisons of type T.
// We record the arguments of CMP instructions in this table unconditionally
// because it seems cheaper this way than to compute some expensive
// conditions inside __sanitizer_cov_trace_cmp*.
// After the unit has been executed we may decide to use the contents of
// this table to populate a Dictionary.
template<class T, size_t kSizeT>
struct TableOfRecentCompares { … };

template <size_t kSizeT>
struct MemMemTable { … };

class TracePC { … };

template <class Callback>
// void Callback(size_t FirstFeature, size_t Idx, uint8_t Value);
ATTRIBUTE_NO_SANITIZE_ALL
size_t ForEachNonZeroByte(const uint8_t *Begin, const uint8_t *End,
                        size_t FirstFeature, Callback Handle8bitCounter) { … }

// Given a non-zero Counter returns a number in the range [0,7].
template<class T>
unsigned CounterToFeature(T Counter) { … }

template <class Callback> // void Callback(uint32_t Feature)
ATTRIBUTE_NO_SANITIZE_ADDRESS ATTRIBUTE_NOINLINE size_t
TracePC::CollectFeatures(Callback HandleFeature) const { … }

extern TracePC TPC;

}  // namespace fuzzer

#endif  // LLVM_FUZZER_TRACE_PC