1 //===- FuzzerMain.cpp - main() 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 //===----------------------------------------------------------------------===//
10 //===----------------------------------------------------------------------===//
12 #include "FuzzerInternal.h"
22 // * don't dump the coverage to disk.
23 // * enable coverage by default.
24 extern "C" const char *__asan_default_options() {
25 return "coverage_pcs=0:coverage=1";
29 struct FlagDescription {
31 const char *Description;
37 #define FUZZER_FLAG(Type, Name, Default, Description) Type Name;
38 #include "FuzzerFlags.def"
42 static FlagDescription FlagDescriptions [] {
43 #define FUZZER_FLAG(Type, Name, Default, Description) {#Name, Description, Default, &Flags.Name},
44 #include "FuzzerFlags.def"
48 static const size_t kNumFlags =
49 sizeof(FlagDescriptions) / sizeof(FlagDescriptions[0]);
51 static std::vector<std::string> inputs;
52 static const char *ProgName;
54 static void PrintHelp() {
55 std::cerr << "Usage: " << ProgName
56 << " [-flag1=val1 [-flag2=val2 ...] ] [dir1 [dir2 ...] ]\n";
57 std::cerr << "\nFlags: (strictly in form -flag=value)\n";
58 size_t MaxFlagLen = 0;
59 for (size_t F = 0; F < kNumFlags; F++)
60 MaxFlagLen = std::max(strlen(FlagDescriptions[F].Name), MaxFlagLen);
62 for (size_t F = 0; F < kNumFlags; F++) {
63 const auto &D = FlagDescriptions[F];
64 std::cerr << " " << D.Name;
65 for (size_t i = 0, n = MaxFlagLen - strlen(D.Name); i < n; i++)
68 std::cerr << D.Default << "\t" << D.Description << "\n";
72 static const char *FlagValue(const char *Param, const char *Name) {
73 size_t Len = strlen(Name);
74 if (Param[0] == '-' && strstr(Param + 1, Name) == Param + 1 &&
75 Param[Len + 1] == '=')
76 return &Param[Len + 2];
80 static bool ParseOneFlag(const char *Param) {
81 if (Param[0] != '-') return false;
82 for (size_t F = 0; F < kNumFlags; F++) {
83 const char *Name = FlagDescriptions[F].Name;
84 const char *Str = FlagValue(Param, Name);
86 int Val = std::stol(Str);
87 *FlagDescriptions[F].Flag = Val;
88 if (Flags.verbosity >= 2)
89 std::cerr << "Flag: " << Name << " " << Val << "\n";
97 // We don't use any library to minimize dependencies.
98 static void ParseFlags(int argc, char **argv) {
99 for (size_t F = 0; F < kNumFlags; F++)
100 *FlagDescriptions[F].Flag = FlagDescriptions[F].Default;
101 for (int A = 1; A < argc; A++) {
102 if (ParseOneFlag(argv[A])) continue;
103 inputs.push_back(argv[A]);
107 static void WorkerThread(const std::string &Cmd, std::atomic<int> *Counter,
110 int C = (*Counter)++;
111 if (C >= NumJobs) return;
112 std::string ToRun = Cmd + " > fuzz-" + std::to_string(C) + ".log 2>&1\n";
115 system(ToRun.c_str());
119 static int RunInMultipleProcesses(int argc, char **argv, int NumWorkers,
121 std::atomic<int> Counter(0);
123 for (int i = 0; i < argc; i++) {
124 if (FlagValue(argv[i], "jobs") || FlagValue(argv[i], "workers")) continue;
128 std::vector<std::thread> V;
129 for (int i = 0; i < NumWorkers; i++)
130 V.push_back(std::thread(WorkerThread, Cmd, &Counter, NumJobs));
136 int main(int argc, char **argv) {
137 using namespace fuzzer;
140 ParseFlags(argc, argv);
146 if (Flags.workers > 0 && Flags.jobs > 0)
147 return RunInMultipleProcesses(argc, argv, Flags.workers, Flags.jobs);
149 Fuzzer::FuzzingOptions Options;
150 Options.Verbosity = Flags.verbosity;
151 Options.MaxLen = Flags.max_len;
152 Options.DoCrossOver = Flags.cross_over;
153 Options.MutateDepth = Flags.mutate_depth;
154 Options.ExitOnFirst = Flags.exit_on_first;
155 Options.UseFullCoverageSet = Flags.use_full_coverage_set;
157 Options.OutputCorpus = inputs[0];
160 unsigned seed = Flags.seed;
163 seed = time(0) * 10000 + getpid();
165 std::cerr << "Seed: " << seed << "\n";
169 if (Flags.timeout > 0)
170 SetTimer(Flags.timeout);
172 for (auto &inp : inputs)
175 if (F.CorpusSize() == 0)
176 F.AddToCorpus(Unit()); // Can't fuzz empty corpus, so add an empty input.
177 F.ShuffleAndMinimize();
178 if (Flags.save_minimized_corpus)
180 F.Loop(Flags.iterations < 0 ? INT_MAX : Flags.iterations);
182 std::cerr << "Done\n";