[fuzzer] split main() into FuzzerDriver() that takes a callback as a parameter and a tiny main() in a separate file

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229882 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Fuzzer/CMakeLists.txt

@@ -3,6 +3,7 @@ set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O2 -fsanitize-coverage=
 if( LLVM_USE_SANITIZE_COVERAGE  )
   add_library(LLVMFuzzerNoMain OBJECT
     FuzzerCrossOver.cpp
+    FuzzerDriver.cpp
     FuzzerIO.cpp
     FuzzerLoop.cpp
     FuzzerMutate.cpp

lib/Fuzzer/FuzzerDriver.cpp

@@ -0,0 +1,198 @@
+//===- FuzzerDriver.cpp - FuzzerDriver function and flags -----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// FuzzerDriver and flag parsing.
+//===----------------------------------------------------------------------===//
+
+#include "FuzzerInterface.h"
+#include "FuzzerInternal.h"
+
+#include <cstring>
+#include <unistd.h>
+#include <iostream>
+#include <thread>
+#include <atomic>
+#include <mutex>
+
+namespace fuzzer {
+
+// Program arguments.
+struct FlagDescription {
+  const char *Name;
+  const char *Description;
+  int   Default;
+  int   *Flag;
+};
+
+struct {
+#define FUZZER_FLAG(Type, Name, Default, Description) Type Name;
+#include "FuzzerFlags.def"
+#undef FUZZER_FLAG
+} Flags;
+
+static FlagDescription FlagDescriptions [] {
+#define FUZZER_FLAG(Type, Name, Default, Description) {#Name, Description, Default, &Flags.Name},
+#include "FuzzerFlags.def"
+#undef FUZZER_FLAG
+};
+
+static const size_t kNumFlags =
+    sizeof(FlagDescriptions) / sizeof(FlagDescriptions[0]);
+
+static std::vector<std::string> inputs;
+static const char *ProgName;
+
+static void PrintHelp() {
+  std::cerr << "Usage: " << ProgName
+            << " [-flag1=val1 [-flag2=val2 ...] ] [dir1 [dir2 ...] ]\n";
+  std::cerr << "\nFlags: (strictly in form -flag=value)\n";
+  size_t MaxFlagLen = 0;
+  for (size_t F = 0; F < kNumFlags; F++)
+    MaxFlagLen = std::max(strlen(FlagDescriptions[F].Name), MaxFlagLen);
+
+  for (size_t F = 0; F < kNumFlags; F++) {
+    const auto &D = FlagDescriptions[F];
+    std::cerr << "  " << D.Name;
+    for (size_t i = 0, n = MaxFlagLen - strlen(D.Name); i < n; i++)
+      std::cerr << " ";
+    std::cerr << "\t";
+    std::cerr << D.Default << "\t" << D.Description << "\n";
+  }
+}
+
+static const char *FlagValue(const char *Param, const char *Name) {
+  size_t Len = strlen(Name);
+  if (Param[0] == '-' && strstr(Param + 1, Name) == Param + 1 &&
+      Param[Len + 1] == '=')
+      return &Param[Len + 2];
+  return nullptr;
+}
+
+static bool ParseOneFlag(const char *Param) {
+  if (Param[0] != '-') return false;
+  for (size_t F = 0; F < kNumFlags; F++) {
+    const char *Name = FlagDescriptions[F].Name;
+    const char *Str = FlagValue(Param, Name);
+    if (Str)  {
+      int Val = std::stol(Str);
+      *FlagDescriptions[F].Flag = Val;
+      if (Flags.verbosity >= 2)
+        std::cerr << "Flag: " << Name << " " << Val << "\n";
+      return true;
+    }
+  }
+  PrintHelp();
+  exit(1);
+}
+
+// We don't use any library to minimize dependencies.
+static void ParseFlags(int argc, char **argv) {
+  for (size_t F = 0; F < kNumFlags; F++)
+    *FlagDescriptions[F].Flag = FlagDescriptions[F].Default;
+  for (int A = 1; A < argc; A++) {
+    if (ParseOneFlag(argv[A])) continue;
+    inputs.push_back(argv[A]);
+  }
+}
+
+static void WorkerThread(const std::string &Cmd, std::atomic<int> *Counter,
+                        int NumJobs, std::atomic<bool> *HasErrors) {
+  static std::mutex CerrMutex;
+  while (true) {
+    int C = (*Counter)++;
+    if (C >= NumJobs) break;
+    std::string Log = "fuzz-" + std::to_string(C) + ".log";
+    std::string ToRun = Cmd + " > " + Log + " 2>&1\n";
+    if (Flags.verbosity)
+      std::cerr << ToRun;
+    int ExitCode = system(ToRun.c_str());
+    if (ExitCode != 0)
+      *HasErrors = true;
+    std::lock_guard<std::mutex> Lock(CerrMutex);
+    std::cerr << "================== Job " << C
+              << " exited with exit code " << ExitCode
+              << " =================\n";
+    fuzzer::CopyFileToErr(Log);
+  }
+}
+
+static int RunInMultipleProcesses(int argc, char **argv, int NumWorkers,
+                                  int NumJobs) {
+  std::atomic<int> Counter(0);
+  std::atomic<bool> HasErrors(false);
+  std::string Cmd;
+  for (int i = 0; i < argc; i++) {
+    if (FlagValue(argv[i], "jobs") || FlagValue(argv[i], "workers")) continue;
+    Cmd += argv[i];
+    Cmd += " ";
+  }
+  std::vector<std::thread> V;
+  for (int i = 0; i < NumWorkers; i++)
+    V.push_back(std::thread(WorkerThread, Cmd, &Counter, NumJobs, &HasErrors));
+  for (auto &T : V)
+    T.join();
+  return HasErrors ? 1 : 0;
+}
+
+int FuzzerDriver(int argc, char **argv, UserCallback Callback) {
+  using namespace fuzzer;
+
+  ProgName = argv[0];
+  ParseFlags(argc, argv);
+  if (Flags.help) {
+    PrintHelp();
+    return 0;
+  }
+
+  if (Flags.workers > 0 && Flags.jobs > 0)
+    return RunInMultipleProcesses(argc, argv, Flags.workers, Flags.jobs);
+
+  Fuzzer::FuzzingOptions Options;
+  Options.Verbosity = Flags.verbosity;
+  Options.MaxLen = Flags.max_len;
+  Options.DoCrossOver = Flags.cross_over;
+  Options.MutateDepth = Flags.mutate_depth;
+  Options.ExitOnFirst = Flags.exit_on_first;
+  Options.UseFullCoverageSet = Flags.use_full_coverage_set;
+  Options.PreferSmallDuringInitialShuffle =
+      Flags.prefer_small_during_initial_shuffle;
+  if (Flags.runs >= 0)
+    Options.MaxNumberOfRuns = Flags.runs;
+  if (!inputs.empty())
+    Options.OutputCorpus = inputs[0];
+  Fuzzer F(Callback, Options);
+
+  unsigned seed = Flags.seed;
+  // Initialize seed.
+  if (seed == 0)
+    seed = time(0) * 10000 + getpid();
+  if (Flags.verbosity)
+    std::cerr << "Seed: " << seed << "\n";
+  srand(seed);
+
+  // Timer
+  if (Flags.timeout > 0)
+    SetTimer(Flags.timeout);
+
+  for (auto &inp : inputs)
+    F.ReadDir(inp);
+
+  if (F.CorpusSize() == 0)
+    F.AddToCorpus(Unit());  // Can't fuzz empty corpus, so add an empty input.
+  F.ShuffleAndMinimize();
+  if (Flags.save_minimized_corpus)
+    F.SaveCorpus();
+  F.Loop(Flags.iterations < 0 ? INT_MAX : Flags.iterations);
+  if (Flags.verbosity)
+    std::cerr << "Done " << F.getTotalNumberOfRuns()
+              << " runs in " << F.secondsSinceProcessStartUp()
+              << " seconds\n";
+  return 0;
+}
+
+}  // namespace fuzzer

lib/Fuzzer/FuzzerInterface.h

@@ -0,0 +1,25 @@
+//===- FuzzerInterface.h - Interface header for the Fuzzer ------*- C++ -* ===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Define the interface between the Fuzzer and the library being tested.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_FUZZER_INTERFACE_H
+#define LLVM_FUZZER_INTERFACE_H
+
+#include <cstddef>
+#include <cstdint>
+
+namespace fuzzer {
+
+typedef void (*UserCallback)(const uint8_t *data, size_t size);
+int FuzzerDriver(int argc, char **argv, UserCallback Callback);
+
+}  // namespace fuzzer
+
+#endif  // LLVM_FUZZER_INTERFACE_H

lib/Fuzzer/FuzzerInternal.h

@@ -17,6 +17,8 @@
 #include <vector>
 #include <unordered_set>
 
+#include "FuzzerInterface.h"
+
 namespace fuzzer {
 typedef std::vector<uint8_t> Unit;
 using namespace std::chrono;
@@ -51,7 +53,8 @@ class Fuzzer {
     size_t MaxNumberOfRuns = ULONG_MAX;
     std::string OutputCorpus;
   };
-  Fuzzer(FuzzingOptions Options) : Options(Options) {
+  Fuzzer(UserCallback Callback, FuzzingOptions Options)
+      : Callback(Callback), Options(Options) {
     SetDeathCallback();
   }
   void AddToCorpus(const Unit &U) { Corpus.push_back(U); }
@@ -89,6 +92,7 @@ class Fuzzer {
 
   std::vector<Unit> Corpus;
   std::unordered_set<uintptr_t> FullCoverageSets;
+  UserCallback Callback;
   FuzzingOptions Options;
   system_clock::time_point ProcessStartTime = system_clock::now();
   static system_clock::time_point UnitStartTime;

lib/Fuzzer/FuzzerLoop.cpp

@@ -14,9 +14,6 @@
 #include <algorithm>
 #include <iostream>
 
-// This function should be defined by the user.
-extern "C" void TestOneInput(const uint8_t *Data, size_t Size);
-
 namespace fuzzer {
 
 // static
@@ -107,7 +104,7 @@ static uintptr_t HashOfArrayOfPCs(uintptr_t *PCs, uintptr_t NumPCs) {
 // e.g. test/FullCoverageSetTest.cpp. FIXME: make it scale.
 size_t Fuzzer::RunOneMaximizeFullCoverageSet(const Unit &U) {
   __sanitizer_reset_coverage();
-  TestOneInput(U.data(), U.size());
+  Callback(U.data(), U.size());
   uintptr_t *PCs;
   uintptr_t NumPCs =__sanitizer_get_coverage_guards(&PCs);
   if (FullCoverageSets.insert(HashOfArrayOfPCs(PCs, NumPCs)).second)
@@ -117,7 +114,7 @@ size_t Fuzzer::RunOneMaximizeFullCoverageSet(const Unit &U) {
 
 size_t Fuzzer::RunOneMaximizeTotalCoverage(const Unit &U) {
   size_t OldCoverage = __sanitizer_get_total_unique_coverage();
-  TestOneInput(U.data(), U.size());
+  Callback(U.data(), U.size());
   size_t NewCoverage = __sanitizer_get_total_unique_coverage();
   if (!(TotalNumberOfRuns & (TotalNumberOfRuns - 1)) && Options.Verbosity) {
     size_t Seconds = secondsSinceProcessStartUp();

lib/Fuzzer/FuzzerMain.cpp

@@ -9,185 +9,12 @@
 // main() and flags.
 //===----------------------------------------------------------------------===//
 
+#include "FuzzerInterface.h"
 #include "FuzzerInternal.h"
 
-#include <cstring>
+// This function should be defined by the user.
-#include <unistd.h>
+extern "C" void TestOneInput(const uint8_t *Data, size_t Size);
-#include <iostream>
-#include <thread>
-#include <atomic>
-#include <mutex>
-
-// Program arguments.
-struct FlagDescription {
-  const char *Name;
-  const char *Description;
-  int   Default;
-  int   *Flag;
-};
-
-struct {
-#define FUZZER_FLAG(Type, Name, Default, Description) Type Name;
-#include "FuzzerFlags.def"
-#undef FUZZER_FLAG
-} Flags;
-
-static FlagDescription FlagDescriptions [] {
-#define FUZZER_FLAG(Type, Name, Default, Description) {#Name, Description, Default, &Flags.Name},
-#include "FuzzerFlags.def"
-#undef FUZZER_FLAG
-};
-
-static const size_t kNumFlags =
-    sizeof(FlagDescriptions) / sizeof(FlagDescriptions[0]);
-
-static std::vector<std::string> inputs;
-static const char *ProgName;
-
-static void PrintHelp() {
-  std::cerr << "Usage: " << ProgName
-            << " [-flag1=val1 [-flag2=val2 ...] ] [dir1 [dir2 ...] ]\n";
-  std::cerr << "\nFlags: (strictly in form -flag=value)\n";
-  size_t MaxFlagLen = 0;
-  for (size_t F = 0; F < kNumFlags; F++)
-    MaxFlagLen = std::max(strlen(FlagDescriptions[F].Name), MaxFlagLen);
-
-  for (size_t F = 0; F < kNumFlags; F++) {
-    const auto &D = FlagDescriptions[F];
-    std::cerr << "  " << D.Name;
-    for (size_t i = 0, n = MaxFlagLen - strlen(D.Name); i < n; i++)
-      std::cerr << " ";
-    std::cerr << "\t";
-    std::cerr << D.Default << "\t" << D.Description << "\n";
-  }
-}
-
-static const char *FlagValue(const char *Param, const char *Name) {
-  size_t Len = strlen(Name);
-  if (Param[0] == '-' && strstr(Param + 1, Name) == Param + 1 &&
-      Param[Len + 1] == '=')
-      return &Param[Len + 2];
-  return nullptr;
-}
-
-static bool ParseOneFlag(const char *Param) {
-  if (Param[0] != '-') return false;
-  for (size_t F = 0; F < kNumFlags; F++) {
-    const char *Name = FlagDescriptions[F].Name;
-    const char *Str = FlagValue(Param, Name);
-    if (Str)  {
-      int Val = std::stol(Str);
-      *FlagDescriptions[F].Flag = Val;
-      if (Flags.verbosity >= 2)
-        std::cerr << "Flag: " << Name << " " << Val << "\n";
-      return true;
-    }
-  }
-  PrintHelp();
-  exit(1);
-}
-
-// We don't use any library to minimize dependencies.
-static void ParseFlags(int argc, char **argv) {
-  for (size_t F = 0; F < kNumFlags; F++)
-    *FlagDescriptions[F].Flag = FlagDescriptions[F].Default;
-  for (int A = 1; A < argc; A++) {
-    if (ParseOneFlag(argv[A])) continue;
-    inputs.push_back(argv[A]);
-  }
-}
-
-static void WorkerThread(const std::string &Cmd, std::atomic<int> *Counter,
-                        int NumJobs, std::atomic<bool> *HasErrors) {
-  static std::mutex CerrMutex;
-  while (true) {
-    int C = (*Counter)++;
-    if (C >= NumJobs) break;
-    std::string Log = "fuzz-" + std::to_string(C) + ".log";
-    std::string ToRun = Cmd + " > " + Log + " 2>&1\n";
-    if (Flags.verbosity)
-      std::cerr << ToRun;
-    int ExitCode = system(ToRun.c_str());
-    if (ExitCode != 0)
-      *HasErrors = true;
-    std::lock_guard<std::mutex> Lock(CerrMutex);
-    std::cerr << "================== Job " << C
-              << " exited with exit code " << ExitCode
-              << " =================\n";
-    fuzzer::CopyFileToErr(Log);
-  }
-}
-
-static int RunInMultipleProcesses(int argc, char **argv, int NumWorkers,
-                                  int NumJobs) {
-  std::atomic<int> Counter(0);
-  std::atomic<bool> HasErrors(false);
-  std::string Cmd;
-  for (int i = 0; i < argc; i++) {
-    if (FlagValue(argv[i], "jobs") || FlagValue(argv[i], "workers")) continue;
-    Cmd += argv[i];
-    Cmd += " ";
-  }
-  std::vector<std::thread> V;
-  for (int i = 0; i < NumWorkers; i++)
-    V.push_back(std::thread(WorkerThread, Cmd, &Counter, NumJobs, &HasErrors));
-  for (auto &T : V)
-    T.join();
-  return HasErrors ? 1 : 0;
-}
 
 int main(int argc, char **argv) {
-  using namespace fuzzer;
+  return fuzzer::FuzzerDriver(argc, argv, TestOneInput);
-
-  ProgName = argv[0];
-  ParseFlags(argc, argv);
-  if (Flags.help) {
-    PrintHelp();
-    return 0;
-  }
-
-  if (Flags.workers > 0 && Flags.jobs > 0)
-    return RunInMultipleProcesses(argc, argv, Flags.workers, Flags.jobs);
-
-  Fuzzer::FuzzingOptions Options;
-  Options.Verbosity = Flags.verbosity;
-  Options.MaxLen = Flags.max_len;
-  Options.DoCrossOver = Flags.cross_over;
-  Options.MutateDepth = Flags.mutate_depth;
-  Options.ExitOnFirst = Flags.exit_on_first;
-  Options.UseFullCoverageSet = Flags.use_full_coverage_set;
-  Options.PreferSmallDuringInitialShuffle =
-      Flags.prefer_small_during_initial_shuffle;
-  if (Flags.runs >= 0)
-    Options.MaxNumberOfRuns = Flags.runs;
-  if (!inputs.empty())
-    Options.OutputCorpus = inputs[0];
-  Fuzzer F(Options);
-
-  unsigned seed = Flags.seed;
-  // Initialize seed.
-  if (seed == 0)
-    seed = time(0) * 10000 + getpid();
-  if (Flags.verbosity)
-    std::cerr << "Seed: " << seed << "\n";
-  srand(seed);
-
-  // Timer
-  if (Flags.timeout > 0)
-    SetTimer(Flags.timeout);
-
-  for (auto &inp : inputs)
-    F.ReadDir(inp);
-
-  if (F.CorpusSize() == 0)
-    F.AddToCorpus(Unit());  // Can't fuzz empty corpus, so add an empty input.
-  F.ShuffleAndMinimize();
-  if (Flags.save_minimized_corpus)
-    F.SaveCorpus();
-  F.Loop(Flags.iterations < 0 ? INT_MAX : Flags.iterations);
-  if (Flags.verbosity)
-    std::cerr << "Done " << F.getTotalNumberOfRuns()
-              << " runs in " << F.secondsSinceProcessStartUp()
-              << " seconds\n";
-  return 0;
 }