1 //===- FuzzerDriver.cpp - FuzzerDriver function and flags -----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
9 // FuzzerDriver and flag parsing.
10 //===----------------------------------------------------------------------===//
12 #include "FuzzerInterface.h"
13 #include "FuzzerInternal.h"
25 struct FlagDescription {
27 const char *Description;
33 #define FUZZER_FLAG(Type, Name, Default, Description) Type Name;
34 #include "FuzzerFlags.def"
38 static FlagDescription FlagDescriptions [] {
39 #define FUZZER_FLAG(Type, Name, Default, Description) {#Name, Description, Default, &Flags.Name},
40 #include "FuzzerFlags.def"
44 static const size_t kNumFlags =
45 sizeof(FlagDescriptions) / sizeof(FlagDescriptions[0]);
47 static std::vector<std::string> inputs;
48 static const char *ProgName;
50 static void PrintHelp() {
51 std::cerr << "Usage: " << ProgName
52 << " [-flag1=val1 [-flag2=val2 ...] ] [dir1 [dir2 ...] ]\n";
53 std::cerr << "\nFlags: (strictly in form -flag=value)\n";
54 size_t MaxFlagLen = 0;
55 for (size_t F = 0; F < kNumFlags; F++)
56 MaxFlagLen = std::max(strlen(FlagDescriptions[F].Name), MaxFlagLen);
58 for (size_t F = 0; F < kNumFlags; F++) {
59 const auto &D = FlagDescriptions[F];
60 std::cerr << " " << D.Name;
61 for (size_t i = 0, n = MaxFlagLen - strlen(D.Name); i < n; i++)
64 std::cerr << D.Default << "\t" << D.Description << "\n";
68 static const char *FlagValue(const char *Param, const char *Name) {
69 size_t Len = strlen(Name);
70 if (Param[0] == '-' && strstr(Param + 1, Name) == Param + 1 &&
71 Param[Len + 1] == '=')
72 return &Param[Len + 2];
76 static bool ParseOneFlag(const char *Param) {
77 if (Param[0] != '-') return false;
78 for (size_t F = 0; F < kNumFlags; F++) {
79 const char *Name = FlagDescriptions[F].Name;
80 const char *Str = FlagValue(Param, Name);
82 int Val = std::stol(Str);
83 *FlagDescriptions[F].Flag = Val;
84 if (Flags.verbosity >= 2)
85 std::cerr << "Flag: " << Name << " " << Val << "\n";
93 // We don't use any library to minimize dependencies.
94 static void ParseFlags(int argc, char **argv) {
95 for (size_t F = 0; F < kNumFlags; F++)
96 *FlagDescriptions[F].Flag = FlagDescriptions[F].Default;
97 for (int A = 1; A < argc; A++) {
98 if (ParseOneFlag(argv[A])) continue;
99 inputs.push_back(argv[A]);
103 static void WorkerThread(const std::string &Cmd, std::atomic<int> *Counter,
104 int NumJobs, std::atomic<bool> *HasErrors) {
105 static std::mutex CerrMutex;
107 int C = (*Counter)++;
108 if (C >= NumJobs) break;
109 std::string Log = "fuzz-" + std::to_string(C) + ".log";
110 std::string ToRun = Cmd + " > " + Log + " 2>&1\n";
113 int ExitCode = system(ToRun.c_str());
116 std::lock_guard<std::mutex> Lock(CerrMutex);
117 std::cerr << "================== Job " << C
118 << " exited with exit code " << ExitCode
119 << " =================\n";
120 fuzzer::CopyFileToErr(Log);
124 static int RunInMultipleProcesses(int argc, char **argv, int NumWorkers,
126 std::atomic<int> Counter(0);
127 std::atomic<bool> HasErrors(false);
129 for (int i = 0; i < argc; i++) {
130 if (FlagValue(argv[i], "jobs") || FlagValue(argv[i], "workers")) continue;
134 std::vector<std::thread> V;
135 for (int i = 0; i < NumWorkers; i++)
136 V.push_back(std::thread(WorkerThread, Cmd, &Counter, NumJobs, &HasErrors));
139 return HasErrors ? 1 : 0;
142 int FuzzerDriver(int argc, char **argv, UserCallback Callback) {
143 using namespace fuzzer;
146 ParseFlags(argc, argv);
152 if (Flags.workers > 0 && Flags.jobs > 0)
153 return RunInMultipleProcesses(argc, argv, Flags.workers, Flags.jobs);
155 Fuzzer::FuzzingOptions Options;
156 Options.Verbosity = Flags.verbosity;
157 Options.MaxLen = Flags.max_len;
158 Options.DoCrossOver = Flags.cross_over;
159 Options.MutateDepth = Flags.mutate_depth;
160 Options.ExitOnFirst = Flags.exit_on_first;
161 Options.UseCounters = Flags.use_counters;
162 Options.UseFullCoverageSet = Flags.use_full_coverage_set;
163 Options.UseCoveragePairs = Flags.use_coverage_pairs;
164 Options.PreferSmallDuringInitialShuffle =
165 Flags.prefer_small_during_initial_shuffle;
167 Options.MaxNumberOfRuns = Flags.runs;
169 Options.OutputCorpus = inputs[0];
170 Fuzzer F(Callback, Options);
172 unsigned seed = Flags.seed;
175 seed = time(0) * 10000 + getpid();
177 std::cerr << "Seed: " << seed << "\n";
181 if (Flags.timeout > 0)
182 SetTimer(Flags.timeout);
184 for (auto &inp : inputs)
187 if (F.CorpusSize() == 0)
188 F.AddToCorpus(Unit()); // Can't fuzz empty corpus, so add an empty input.
189 F.ShuffleAndMinimize();
190 if (Flags.save_minimized_corpus)
192 F.Loop(Flags.iterations < 0 ? INT_MAX : Flags.iterations);
194 std::cerr << "Done " << F.getTotalNumberOfRuns()
195 << " runs in " << F.secondsSinceProcessStartUp()
200 } // namespace fuzzer