[libFuzzer] apply changes lost during the migration to compiler-rt

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@311420 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 27 insertions, 23 deletions

diff --git a/lib/fuzzer/FuzzerTracePC.h b/lib/fuzzer/FuzzerTracePC.h
index ea6794c75..56f1820f7 100644
--- a/lib/fuzzer/FuzzerTracePC.h
+++ b/lib/fuzzer/FuzzerTracePC.h
@@ -91,6 +91,7 @@ class TracePC {
       memset(Counters(), 0, GetNumPCs());
     ClearExtraCounters();
     ClearInlineCounters();
+    ClearClangCounters();
   }
 
   void ClearInlineCounters();
@@ -119,19 +120,8 @@ class TracePC {
     return PCs()[Idx];
   }
 
-  void RecordCurrentStack() {
-    uintptr_t Stack = GetCurrentStack();
-    if (Stack < LowestStack)
-      LowestStack = Stack;
-  }
-  void RecordInitialStack() {
-    InitialStack = GetCurrentStack();
-    LowestStack = InitialStack;
-  }
-  uintptr_t GetCurrentStack() const {
-    return reinterpret_cast<uintptr_t>(__builtin_frame_address(0));
-  }
-  uintptr_t GetMaxStackOffset() const { return InitialStack - LowestStack; }
+  void RecordInitialStack();
+  uintptr_t GetMaxStackOffset() const;
 
   template<class CallBack>
   void ForEachObservedPC(CallBack CB) {
@@ -166,7 +156,7 @@ private:
   std::set<uintptr_t> ObservedPCs;
 
   ValueBitMap ValueProfileMap;
-  uintptr_t InitialStack, LowestStack;  // Assume stack grows down.
+  uintptr_t InitialStack;
 };
 
 template <class Callback>
@@ -196,14 +186,9 @@ void ForEachNonZeroByte(const uint8_t *Begin, const uint8_t *End,
       Handle8bitCounter(FirstFeature, P - Begin, V);
 }
 
-template <class Callback>  // bool Callback(size_t Feature)
-ATTRIBUTE_NO_SANITIZE_ADDRESS
-__attribute__((noinline))
-void TracePC::CollectFeatures(Callback HandleFeature) const {
-  uint8_t *Counters = this->Counters();
-  size_t N = GetNumPCs();
-  auto Handle8bitCounter = [&](size_t FirstFeature,
-                               size_t Idx, uint8_t Counter) {
+// Given a non-zero Counters returns a number in [0,7].
+template<class T>
+unsigned CounterToFeature(T Counter) {
     assert(Counter);
     unsigned Bit = 0;
     /**/ if (Counter >= 128) Bit = 7;
@@ -213,7 +198,18 @@ void TracePC::CollectFeatures(Callback HandleFeature) const {
     else if (Counter >= 4) Bit = 3;
     else if (Counter >= 3) Bit = 2;
     else if (Counter >= 2) Bit = 1;
-    HandleFeature(FirstFeature + Idx * 8 + Bit);
+    return Bit;
+}
+
+template <class Callback>  // bool Callback(size_t Feature)
+ATTRIBUTE_NO_SANITIZE_ADDRESS
+__attribute__((noinline))
+void TracePC::CollectFeatures(Callback HandleFeature) const {
+  uint8_t *Counters = this->Counters();
+  size_t N = GetNumPCs();
+  auto Handle8bitCounter = [&](size_t FirstFeature,
+                               size_t Idx, uint8_t Counter) {
+    HandleFeature(FirstFeature + Idx * 8 + CounterToFeature(Counter));
   };
 
   size_t FirstFeature = 0;
@@ -231,6 +227,14 @@ void TracePC::CollectFeatures(Callback HandleFeature) const {
     }
   }
 
+  if (size_t NumClangCounters = ClangCountersEnd() - ClangCountersBegin()) {
+    auto P = ClangCountersBegin();
+    for (size_t Idx = 0; Idx < NumClangCounters; Idx++)
+      if (auto Cnt = P[Idx])
+        HandleFeature(FirstFeature + Idx * 8 + CounterToFeature(Cnt));
+    FirstFeature += NumClangCounters;
+  }
+
   ForEachNonZeroByte(ExtraCountersBegin(), ExtraCountersEnd(), FirstFeature,
                      Handle8bitCounter);
   FirstFeature += (ExtraCountersEnd() - ExtraCountersBegin()) * 8;