llvm-project/compiler-rt/lib/fuzzer/FuzzerDataFlowTrace.h

138 lines
4.1 KiB
C++

//===- FuzzerDataFlowTrace.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::DataFlowTrace; reads and handles a data-flow trace.
//
// A data flow trace is generated by e.g. dataflow/DataFlow.cpp
// and is stored on disk in a separate directory.
//
// The trace dir contains a file 'functions.txt' which lists function names,
// oner per line, e.g.
// ==> functions.txt <==
// Func2
// LLVMFuzzerTestOneInput
// Func1
//
// All other files in the dir are the traces, see dataflow/DataFlow.cpp.
// The name of the file is sha1 of the input used to generate the trace.
//
// Current status:
// the data is parsed and the summary is printed, but the data is not yet
// used in any other way.
//===----------------------------------------------------------------------===//
#ifndef LLVM_FUZZER_DATA_FLOW_TRACE
#define LLVM_FUZZER_DATA_FLOW_TRACE
#include "FuzzerDefs.h"
#include "FuzzerIO.h"
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include <string>
namespace fuzzer {
int CollectDataFlow(const std::string &DFTBinary, const std::string &DirPath,
const std::vector<SizedFile> &CorporaFiles);
class BlockCoverage {
public:
// These functions guarantee no CoverageVector is longer than UINT32_MAX.
bool AppendCoverage(std::istream &IN);
bool AppendCoverage(const std::string &S);
size_t NumCoveredFunctions() const { return Functions.size(); }
uint32_t GetCounter(size_t FunctionId, size_t BasicBlockId) {
auto It = Functions.find(FunctionId);
if (It == Functions.end())
return 0;
const auto &Counters = It->second;
if (BasicBlockId < Counters.size())
return Counters[BasicBlockId];
return 0;
}
uint32_t GetNumberOfBlocks(size_t FunctionId) {
auto It = Functions.find(FunctionId);
if (It == Functions.end()) return 0;
const auto &Counters = It->second;
return static_cast<uint32_t>(Counters.size());
}
uint32_t GetNumberOfCoveredBlocks(size_t FunctionId) {
auto It = Functions.find(FunctionId);
if (It == Functions.end()) return 0;
const auto &Counters = It->second;
uint32_t Result = 0;
for (auto Cnt: Counters)
if (Cnt)
Result++;
return Result;
}
std::vector<double> FunctionWeights(size_t NumFunctions) const;
void clear() { Functions.clear(); }
private:
typedef std::vector<uint32_t> CoverageVector;
uint32_t NumberOfCoveredBlocks(const CoverageVector &Counters) const {
uint32_t Res = 0;
for (auto Cnt : Counters)
if (Cnt)
Res++;
return Res;
}
uint32_t NumberOfUncoveredBlocks(const CoverageVector &Counters) const {
return static_cast<uint32_t>(Counters.size()) -
NumberOfCoveredBlocks(Counters);
}
uint32_t SmallestNonZeroCounter(const CoverageVector &Counters) const {
assert(!Counters.empty());
uint32_t Res = Counters[0];
for (auto Cnt : Counters)
if (Cnt)
Res = Min(Res, Cnt);
assert(Res);
return Res;
}
// Function ID => vector of counters.
// Each counter represents how many input files trigger the given basic block.
std::unordered_map<size_t, CoverageVector> Functions;
// Functions that have DFT entry.
std::unordered_set<size_t> FunctionsWithDFT;
};
class DataFlowTrace {
public:
void ReadCoverage(const std::string &DirPath);
bool Init(const std::string &DirPath, std::string *FocusFunction,
std::vector<SizedFile> &CorporaFiles, Random &Rand);
void Clear() { Traces.clear(); }
const std::vector<uint8_t> *Get(const std::string &InputSha1) const {
auto It = Traces.find(InputSha1);
if (It != Traces.end())
return &It->second;
return nullptr;
}
private:
// Input's sha1 => DFT for the FocusFunction.
std::unordered_map<std::string, std::vector<uint8_t>> Traces;
BlockCoverage Coverage;
std::unordered_set<std::string> CorporaHashes;
};
} // namespace fuzzer
#endif // LLVM_FUZZER_DATA_FLOW_TRACE