[llvm] r278975 - [libFuzzer] when printing the reproducer input, also print the base input and the mutation sequence

[Kostya Serebryany via llvm-commits]

Author: kcc
Date: Wed Aug 17 15:45:23 2016
New Revision: 278975

URL: http://llvm.org/viewvc/llvm-project?rev=278975&view=rev
Log:
[libFuzzer] when printing the reproducer input, also print the base input and the mutation sequence

Modified:
    llvm/trunk/lib/Fuzzer/FuzzerInternal.h
    llvm/trunk/lib/Fuzzer/FuzzerLoop.cpp
    llvm/trunk/lib/Fuzzer/FuzzerUtil.cpp

Modified: llvm/trunk/lib/Fuzzer/FuzzerInternal.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Fuzzer/FuzzerInternal.h?rev=278975&r1=278974&r2=278975&view=diff
==============================================================================
--- llvm/trunk/lib/Fuzzer/FuzzerInternal.h (original)
+++ llvm/trunk/lib/Fuzzer/FuzzerInternal.h Wed Aug 17 15:45:23 2016
@@ -120,6 +120,7 @@ size_t GetPeakRSSMb();
 static const int kSHA1NumBytes = 20;
 // Computes SHA1 hash of 'Len' bytes in 'Data', writes kSHA1NumBytes to 'Out'.
 void ComputeSHA1(const uint8_t *Data, size_t Len, uint8_t *Out);
+std::string Sha1ToString(uint8_t Sha1[kSHA1NumBytes]);
 
 // Changes U to contain only ASCII (isprint+isspace) characters.
 // Returns true iff U has been changed.
@@ -482,6 +483,7 @@ private:
   void LazyAllocateCurrentUnitData();
   uint8_t *CurrentUnitData = nullptr;
   std::atomic<size_t> CurrentUnitSize;
+  uint8_t BaseSha1[kSHA1NumBytes];  // Checksum of the base unit.
 
   size_t TotalNumberOfRuns = 0;
   size_t NumberOfNewUnitsAdded = 0;

Modified: llvm/trunk/lib/Fuzzer/FuzzerLoop.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Fuzzer/FuzzerLoop.cpp?rev=278975&r1=278974&r2=278975&view=diff
==============================================================================
--- llvm/trunk/lib/Fuzzer/FuzzerLoop.cpp (original)
+++ llvm/trunk/lib/Fuzzer/FuzzerLoop.cpp Wed Aug 17 15:45:23 2016
@@ -204,6 +204,8 @@ void Fuzzer::StaticDeathCallback() {
 
 void Fuzzer::DumpCurrentUnit(const char *Prefix) {
   if (!CurrentUnitData) return;  // Happens when running individual inputs.
+  MD.PrintMutationSequence();
+  Printf("; base unit: %s\n", Sha1ToString(BaseSha1).c_str());
   size_t UnitSize = CurrentUnitSize;
   if (UnitSize <= kMaxUnitSizeToPrint) {
     PrintHexArray(CurrentUnitData, UnitSize, "\n");
@@ -693,6 +695,7 @@ void Fuzzer::MutateAndTestOne() {
   MD.StartMutationSequence();
 
   auto &U = ChooseUnitToMutate();
+  ComputeSHA1(U.data(), U.size(), BaseSha1);  // Remember where we started.
   assert(CurrentUnitData);
   size_t Size = U.size();
   assert(Size <= Options.MaxLen && "Oversized Unit");

Modified: llvm/trunk/lib/Fuzzer/FuzzerUtil.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Fuzzer/FuzzerUtil.cpp?rev=278975&r1=278974&r2=278975&view=diff
==============================================================================
--- llvm/trunk/lib/Fuzzer/FuzzerUtil.cpp (original)
+++ llvm/trunk/lib/Fuzzer/FuzzerUtil.cpp Wed Aug 17 15:45:23 2016
@@ -63,15 +63,19 @@ void PrintASCII(const Unit &U, const cha
   PrintASCII(U.data(), U.size(), PrintAfter);
 }
 
-std::string Hash(const Unit &U) {
-  uint8_t Hash[kSHA1NumBytes];
-  ComputeSHA1(U.data(), U.size(), Hash);
+std::string Sha1ToString(uint8_t Sha1[kSHA1NumBytes]) {
   std::stringstream SS;
   for (int i = 0; i < kSHA1NumBytes; i++)
-    SS << std::hex << std::setfill('0') << std::setw(2) << (unsigned)Hash[i];
+    SS << std::hex << std::setfill('0') << std::setw(2) << (unsigned)Sha1[i];
   return SS.str();
 }
 
+std::string Hash(const Unit &U) {
+  uint8_t Hash[kSHA1NumBytes];
+  ComputeSHA1(U.data(), U.size(), Hash);
+  return Sha1ToString(Hash);
+}
+
 static void AlarmHandler(int, siginfo_t *, void *) {
   Fuzzer::StaticAlarmCallback();
 }