Index: lib/Fuzzer/FuzzerDriver.cpp
===================================================================
--- lib/Fuzzer/FuzzerDriver.cpp
+++ lib/Fuzzer/FuzzerDriver.cpp
@@ -297,7 +297,7 @@
 
   const size_t kMaxSaneLen = 1 << 20;
   const size_t kMinDefaultLen = 64;
-  Fuzzer::FuzzingOptions Options;
+  FuzzingOptions Options;
   Options.Verbosity = Flags.verbosity;
   Options.MaxLen = Flags.max_len;
   Options.UnitTimeoutSec = Flags.timeout;
@@ -347,7 +347,7 @@
     Printf("INFO: Seed: %u\n", Seed);
 
   Random Rand(Seed);
-  MutationDispatcher MD(Rand);
+  MutationDispatcher MD(Rand, Options);
   Fuzzer F(Callback, MD, Options);
 
   for (auto &U: Dictionary)
Index: lib/Fuzzer/FuzzerInternal.h
===================================================================
--- lib/Fuzzer/FuzzerInternal.h
+++ lib/Fuzzer/FuzzerInternal.h
@@ -203,9 +203,43 @@
   size_t Size = 0;
 };
 
+struct FuzzingOptions {
+  int Verbosity = 1;
+  size_t MaxLen = 0;
+  int UnitTimeoutSec = 300;
+  int TimeoutExitCode = 77;
+  int ErrorExitCode = 77;
+  int MaxTotalTimeSec = 0;
+  int RssLimitMb = 0;
+  bool DoCrossOver = true;
+  int MutateDepth = 5;
+  bool UseCounters = false;
+  bool UseIndirCalls = true;
+  bool UseTraces = false;
+  bool UseMemcmp = true;
+  bool UseFullCoverageSet = false;
+  bool Reload = true;
+  bool ShuffleAtStartUp = true;
+  bool PreferSmall = true;
+  size_t MaxNumberOfRuns = ULONG_MAX;
+  int ReportSlowUnits = 10;
+  bool OnlyASCII = false;
+  std::string OutputCorpus;
+  std::string ArtifactPrefix = "./";
+  std::string ExactArtifactPath;
+  bool SaveArtifacts = true;
+  bool PrintNEW = true; // Print a status line when new units are found;
+  bool OutputCSV = false;
+  bool PrintNewCovPcs = false;
+  bool PrintFinalStats = false;
+  bool DetectLeaks = true;
+  bool TruncateUnits = false;
+  bool PruneCorpus = true;
+};
+
 class MutationDispatcher {
 public:
-  MutationDispatcher(Random &Rand);
+  MutationDispatcher(Random &Rand, const FuzzingOptions &Options);
   ~MutationDispatcher() {}
   /// Indicate that we are about to start a new sequence of mutations.
   void StartMutationSequence();
@@ -280,6 +314,8 @@
                     const std::vector<Mutator> &Mutators);
 
   Random &Rand;
+  const FuzzingOptions Options;
+
   // Dictionary provided by the user via -dict=DICT_FILE.
   Dictionary ManualDictionary;
   // Temporary dictionary modified by the fuzzer itself,
@@ -299,39 +335,6 @@
 
 class Fuzzer {
 public:
-  struct FuzzingOptions {
-    int Verbosity = 1;
-    size_t MaxLen = 0;
-    int UnitTimeoutSec = 300;
-    int TimeoutExitCode = 77;
-    int ErrorExitCode = 77;
-    int MaxTotalTimeSec = 0;
-    int RssLimitMb = 0;
-    bool DoCrossOver = true;
-    int MutateDepth = 5;
-    bool UseCounters = false;
-    bool UseIndirCalls = true;
-    bool UseTraces = false;
-    bool UseMemcmp = true;
-    bool UseFullCoverageSet = false;
-    bool Reload = true;
-    bool ShuffleAtStartUp = true;
-    bool PreferSmall = true;
-    size_t MaxNumberOfRuns = ULONG_MAX;
-    int ReportSlowUnits = 10;
-    bool OnlyASCII = false;
-    std::string OutputCorpus;
-    std::string ArtifactPrefix = "./";
-    std::string ExactArtifactPath;
-    bool SaveArtifacts = true;
-    bool PrintNEW = true; // Print a status line when new units are found;
-    bool OutputCSV = false;
-    bool PrintNewCovPcs = false;
-    bool PrintFinalStats = false;
-    bool DetectLeaks = true;
-    bool TruncateUnits = false;
-    bool PruneCorpus = true;
-  };
 
   // Aggregates all available coverage measurements.
   struct Coverage {
Index: lib/Fuzzer/FuzzerLoop.cpp
===================================================================
--- lib/Fuzzer/FuzzerLoop.cpp
+++ lib/Fuzzer/FuzzerLoop.cpp
@@ -60,14 +60,13 @@
     PcMapResetCurrent();
   }
 
-  static void ResetCounters(const Fuzzer::FuzzingOptions &Options) {
+  static void ResetCounters(const FuzzingOptions &Options) {
     if (Options.UseCounters) {
       EF->__sanitizer_update_counter_bitset_and_clear_counters(0);
     }
   }
 
-  static void Prepare(const Fuzzer::FuzzingOptions &Options,
-                      Fuzzer::Coverage *C) {
+  static void Prepare(const FuzzingOptions &Options, Fuzzer::Coverage *C) {
     if (Options.UseCounters) {
       size_t NumCounters = EF->__sanitizer_get_number_of_counters();
       C->CounterBitmap.resize(NumCounters);
@@ -76,8 +75,7 @@
 
   // Records data to a maximum coverage tracker. Returns true if additional
   // coverage was discovered.
-  static bool RecordMax(const Fuzzer::FuzzingOptions &Options,
-                        Fuzzer::Coverage *C) {
+  static bool RecordMax(const FuzzingOptions &Options, Fuzzer::Coverage *C) {
     bool Res = false;
 
     uint64_t NewBlockCoverage = EF->__sanitizer_get_total_unique_coverage();
@@ -547,6 +545,7 @@
     MD.PrintMutationSequence();
     Printf("\n");
   }
+  // PrintASCII(U, "\n");
 }
 
 void Fuzzer::ReportNewCoverage(const Unit &U) {
@@ -675,8 +674,6 @@
     assert(NewSize <= Options.MaxLen &&
            "Mutator return overisized unit");
     Size = NewSize;
-    if (Options.OnlyASCII)
-      ToASCII(CurrentUnitData, Size);
     if (i == 0)
       StartTraceRecording();
     RunOneAndUpdateCorpus(CurrentUnitData, Size);
Index: lib/Fuzzer/FuzzerMutate.cpp
===================================================================
--- lib/Fuzzer/FuzzerMutate.cpp
+++ lib/Fuzzer/FuzzerMutate.cpp
@@ -18,7 +18,9 @@
 
 const size_t Dictionary::kMaxDictSize;
 
-MutationDispatcher::MutationDispatcher(Random &Rand) : Rand(Rand) {
+MutationDispatcher::MutationDispatcher(Random &Rand,
+                                       const FuzzingOptions &Options)
+    : Rand(Rand), Options(Options) {
   DefaultMutators.insert(
       DefaultMutators.begin(),
       {
@@ -285,6 +287,8 @@
   if (Size == 0) {
     for (size_t i = 0; i < MaxSize; i++)
       Data[i] = RandCh(Rand);
+    if (Options.OnlyASCII)
+      ToASCII(Data, MaxSize);
     return MaxSize;
   }
   assert(Size > 0);
@@ -295,6 +299,8 @@
     auto M = Mutators[Rand(Mutators.size())];
     size_t NewSize = (this->*(M.Fn))(Data, Size, MaxSize);
     if (NewSize) {
+      if (Options.OnlyASCII)
+        ToASCII(Data, NewSize);
       CurrentMutatorSequence.push_back(M);
       return NewSize;
     }
Index: lib/Fuzzer/FuzzerTraceState.cpp
===================================================================
--- lib/Fuzzer/FuzzerTraceState.cpp
+++ lib/Fuzzer/FuzzerTraceState.cpp
@@ -173,8 +173,8 @@
 static bool RecordingMemcmp = false;
 
 class TraceState {
- public:
-  TraceState(MutationDispatcher &MD, const Fuzzer::FuzzingOptions &Options,
+public:
+  TraceState(MutationDispatcher &MD, const FuzzingOptions &Options,
              const Fuzzer *F)
       : MD(MD), Options(Options), F(F) {}
 
@@ -209,7 +209,8 @@
   }
 
   void StopTraceRecording() {
-    if (!RecordingTraces && !RecordingMemcmp) return;
+    if (!RecordingTraces && !RecordingMemcmp)
+      return;
     RecordingTraces = false;
     RecordingMemcmp = false;
     for (size_t i = 0; i < NumMutations; i++) {
@@ -287,7 +288,7 @@
   LabelRange LabelRanges[1 << (sizeof(dfsan_label) * 8)];
   size_t LastDfsanLabel = 0;
   MutationDispatcher &MD;
-  const Fuzzer::FuzzingOptions &Options;
+  const FuzzingOptions Options;
   const Fuzzer *F;
   std::map<Word, size_t> AutoDictUnitCounts;
   size_t AutoDictAdds = 0;
Index: lib/Fuzzer/test/FuzzerUnittest.cpp
===================================================================
--- lib/Fuzzer/test/FuzzerUnittest.cpp
+++ lib/Fuzzer/test/FuzzerUnittest.cpp
@@ -22,7 +22,7 @@
   std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
   fuzzer::EF = t.get();
   Random Rand(0);
-  MutationDispatcher MD(Rand);
+  MutationDispatcher MD(Rand, {});
   Unit A({0, 1, 2}), B({5, 6, 7});
   Unit C;
   Unit Expected[] = {
@@ -100,7 +100,7 @@
   uint8_t REM6[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x77};
   uint8_t REM7[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66};
   Random Rand(0);
-  MutationDispatcher MD(Rand);
+  MutationDispatcher MD(Rand, {});
   int FoundMask = 0;
   for (int i = 0; i < NumIter; i++) {
     uint8_t T[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
@@ -128,7 +128,7 @@
   std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
   fuzzer::EF = t.get();
   Random Rand(0);
-  MutationDispatcher MD(Rand);
+  MutationDispatcher MD(Rand, {});
   int FoundMask = 0;
   uint8_t INS0[8] = {0xF1, 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66};
   uint8_t INS1[8] = {0x00, 0xF2, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66};
@@ -164,7 +164,7 @@
   std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
   fuzzer::EF = t.get();
   Random Rand(0);
-  MutationDispatcher MD(Rand);
+  MutationDispatcher MD(Rand, {});
   int FoundMask = 0;
   uint8_t CH0[8] = {0xF0, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
   uint8_t CH1[8] = {0x00, 0xF1, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
@@ -200,7 +200,7 @@
   std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
   fuzzer::EF = t.get();
   Random Rand(0);
-  MutationDispatcher MD(Rand);
+  MutationDispatcher MD(Rand, {});
   int FoundMask = 0;
   uint8_t CH0[8] = {0x01, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
   uint8_t CH1[8] = {0x00, 0x13, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
@@ -236,7 +236,7 @@
   std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
   fuzzer::EF = t.get();
   Random Rand(0);
-  MutationDispatcher MD(Rand);
+  MutationDispatcher MD(Rand, {});
   int FoundMask = 0;
   uint8_t CH0[7] = {0x00, 0x22, 0x11, 0x33, 0x44, 0x55, 0x66};
   uint8_t CH1[7] = {0x11, 0x00, 0x33, 0x22, 0x44, 0x55, 0x66};
@@ -266,7 +266,7 @@
   std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
   fuzzer::EF = t.get();
   Random Rand(0);
-  MutationDispatcher MD(Rand);
+  MutationDispatcher MD(Rand, {});
   uint8_t Word1[4] = {0xAA, 0xBB, 0xCC, 0xDD};
   uint8_t Word2[3] = {0xFF, 0xEE, 0xEF};
   MD.AddWordToManualDictionary(Word(Word1, sizeof(Word1)));
@@ -308,7 +308,7 @@
   std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
   fuzzer::EF = t.get();
   Random Rand(0);
-  MutationDispatcher MD(Rand);
+  MutationDispatcher MD(Rand, {});
   uint8_t W[] = {0xAA, 0xBB, 0xCC, 0xDD, 0xFF, 0xEE, 0xEF};
   size_t PosHint = 7777;
   MD.AddWordToAutoDictionary(Word(W, sizeof(W)), PosHint);
@@ -337,7 +337,7 @@
   std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
   fuzzer::EF = t.get();
   Random Rand(0);
-  MutationDispatcher MD(Rand);
+  MutationDispatcher MD(Rand, {});
 
   uint8_t CH0[8] = {'1', '2', '3', '4', '5', '6', '7', '7'};
   uint8_t CH1[8] = {'1', '2', '3', '4', '5', '6', '7', '9'};
@@ -431,9 +431,8 @@
   std::unique_ptr<ExternalFunctions> t(new ExternalFunctions());
   fuzzer::EF = t.get();
   Random Rand(0);
-  MutationDispatcher MD(Rand);
-  Fuzzer::FuzzingOptions Options;
-  Fuzzer Fuzz(LLVMFuzzerTestOneInput, MD, Options);
+  MutationDispatcher MD(Rand, {});
+  Fuzzer Fuzz(LLVMFuzzerTestOneInput, MD, {});
   size_t N = 10;
   size_t TriesPerUnit = 1<<20;
   for (size_t i = 0; i < N; i++) {