1 files changed, 39 insertions, 19 deletions

diff --git a/lib/fuzzer/FuzzerMutate.cpp b/lib/fuzzer/FuzzerMutate.cpp
index 6f6ce075a..e89e1a475 100644
--- a/lib/fuzzer/FuzzerMutate.cpp
+++ b/lib/fuzzer/FuzzerMutate.cpp
@@ -30,34 +30,36 @@ MutationDispatcher::MutationDispatcher(Random &Rand,
   DefaultMutators.insert(
       DefaultMutators.begin(),
       {
-          {&MutationDispatcher::Mutate_EraseBytes, "EraseBytes"},
-          {&MutationDispatcher::Mutate_InsertByte, "InsertByte"},
+          {&MutationDispatcher::Mutate_EraseBytes, "EraseBytes", 0, 0},
+          {&MutationDispatcher::Mutate_InsertByte, "InsertByte", 0, 0},
           {&MutationDispatcher::Mutate_InsertRepeatedBytes,
-           "InsertRepeatedBytes"},
-          {&MutationDispatcher::Mutate_ChangeByte, "ChangeByte"},
-          {&MutationDispatcher::Mutate_ChangeBit, "ChangeBit"},
-          {&MutationDispatcher::Mutate_ShuffleBytes, "ShuffleBytes"},
-          {&MutationDispatcher::Mutate_ChangeASCIIInteger, "ChangeASCIIInt"},
-          {&MutationDispatcher::Mutate_ChangeBinaryInteger, "ChangeBinInt"},
-          {&MutationDispatcher::Mutate_CopyPart, "CopyPart"},
-          {&MutationDispatcher::Mutate_CrossOver, "CrossOver"},
+           "InsertRepeatedBytes", 0, 0},
+          {&MutationDispatcher::Mutate_ChangeByte, "ChangeByte", 0, 0},
+          {&MutationDispatcher::Mutate_ChangeBit, "ChangeBit", 0, 0},
+          {&MutationDispatcher::Mutate_ShuffleBytes, "ShuffleBytes", 0, 0},
+          {&MutationDispatcher::Mutate_ChangeASCIIInteger, "ChangeASCIIInt", 0,
+           0},
+          {&MutationDispatcher::Mutate_ChangeBinaryInteger, "ChangeBinInt", 0,
+           0},
+          {&MutationDispatcher::Mutate_CopyPart, "CopyPart", 0, 0},
+          {&MutationDispatcher::Mutate_CrossOver, "CrossOver", 0, 0},
           {&MutationDispatcher::Mutate_AddWordFromManualDictionary,
-           "ManualDict"},
+           "ManualDict", 0, 0},
           {&MutationDispatcher::Mutate_AddWordFromPersistentAutoDictionary,
-           "PersAutoDict"},
+           "PersAutoDict", 0, 0},
       });
   if(Options.UseCmp)
     DefaultMutators.push_back(
-        {&MutationDispatcher::Mutate_AddWordFromTORC, "CMP"});
+        {&MutationDispatcher::Mutate_AddWordFromTORC, "CMP", 0, 0});
 
   if (EF->LLVMFuzzerCustomMutator)
-    Mutators.push_back({&MutationDispatcher::Mutate_Custom, "Custom"});
+    Mutators.push_back({&MutationDispatcher::Mutate_Custom, "Custom", 0, 0});
   else
     Mutators = DefaultMutators;
 
   if (EF->LLVMFuzzerCustomCrossOver)
     Mutators.push_back(
-        {&MutationDispatcher::Mutate_CustomCrossOver, "CustomCrossOver"});
+        {&MutationDispatcher::Mutate_CustomCrossOver, "CustomCrossOver", 0, 0});
 }
 
 static char RandCh(Random &Rand) {
@@ -464,6 +466,7 @@ void MutationDispatcher::RecordSuccessfulMutationSequence() {
     if (!PersistentAutoDictionary.ContainsWord(DE->GetW()))
       PersistentAutoDictionary.push_back({DE->GetW(), 1});
   }
+  RecordUsefulMutations();
 }
 
 void MutationDispatcher::PrintRecommendedDictionary() {
@@ -484,8 +487,7 @@ void MutationDispatcher::PrintRecommendedDictionary() {
 
 void MutationDispatcher::PrintMutationSequence() {
   Printf("MS: %zd ", CurrentMutatorSequence.size());
-  for (auto M : CurrentMutatorSequence)
-    Printf("%s-", M.Name);
+  for (auto M : CurrentMutatorSequence) Printf("%s-", M->Name);
   if (!CurrentDictionaryEntrySequence.empty()) {
     Printf(" DE: ");
     for (auto DE : CurrentDictionaryEntrySequence) {
@@ -513,12 +515,13 @@ size_t MutationDispatcher::MutateImpl(uint8_t *Data, size_t Size,
   // in which case they will return 0.
   // Try several times before returning un-mutated data.
   for (int Iter = 0; Iter < 100; Iter++) {
-    auto M = Mutators[Rand(Mutators.size())];
-    size_t NewSize = (this->*(M.Fn))(Data, Size, MaxSize);
+    auto M = &Mutators[Rand(Mutators.size())];
+    size_t NewSize = (this->*(M->Fn))(Data, Size, MaxSize);
     if (NewSize && NewSize <= MaxSize) {
       if (Options.OnlyASCII)
         ToASCII(Data, NewSize);
       CurrentMutatorSequence.push_back(M);
+      M->TotalCount++;
       return NewSize;
     }
   }
@@ -531,4 +534,21 @@ void MutationDispatcher::AddWordToManualDictionary(const Word &W) {
       {W, std::numeric_limits<size_t>::max()});
 }
 
+void MutationDispatcher::RecordUsefulMutations() {
+  for (auto M : CurrentMutatorSequence) M->UsefulCount++;
+}
+
+void MutationDispatcher::PrintMutationStats() {
+  Printf("\nstat::mutation_usefulness:      ");
+  for (size_t i = 0; i < Mutators.size(); i++) {
+    double UsefulPercentage =
+        Mutators[i].TotalCount
+            ? (100.0 * Mutators[i].UsefulCount) / Mutators[i].TotalCount
+            : 0;
+    Printf("%.3f", UsefulPercentage);
+    if (i < Mutators.size() - 1) Printf(",");
+  }
+  Printf("\n");
+}
+
 }  // namespace fuzzer