Tolerate negative offset when matching sample profile.

[oota-llvm.git] / lib / ProfileData / SampleProfReader.cpp

diff --git a/lib/ProfileData/SampleProfReader.cpp b/lib/ProfileData/SampleProfReader.cpp
index d184969e046c8feda1a315a1cb6fe5be961b562f..899343f72f78f2b4ef1cc980b8201e5fbb3a0ea4 100644 (file)
--- a/lib/ProfileData/SampleProfReader.cpp
+++ b/lib/ProfileData/SampleProfReader.cpp
@@ -100,6 +100,12 @@ static bool ParseHead(const StringRef &Input, StringRef &FName,
   return true;
 }
 
+
+/// \brief Returns true if line offset \p L is legal (only has 16 bits).
+static bool isOffsetLegal(unsigned L) {
+  return (L & 0xffff) == L;
+}
+
 /// \brief Parse \p Input as line sample.
 ///
 /// \param Input input line.
@@ -124,7 +130,7 @@ static bool ParseLine(const StringRef &Input, bool &IsCallsite, uint32_t &Depth,
   StringRef Loc = Input.substr(Depth, n1 - Depth);
   size_t n2 = Loc.find('.');
   if (n2 == StringRef::npos) {
-    if (Loc.getAsInteger(10, LineOffset))
+    if (Loc.getAsInteger(10, LineOffset) || !isOffsetLegal(LineOffset))
       return false;
     Discriminator = 0;
   } else {
@@ -308,6 +314,10 @@ SampleProfileReaderBinary::readProfile(FunctionSamples &FProfile) {
     if (std::error_code EC = LineOffset.getError())
       return EC;
 
+    if (!isOffsetLegal(*LineOffset)) {
+      return std::error_code();
+    }
+
     auto Discriminator = readNumber<uint64_t>();
     if (std::error_code EC = Discriminator.getError())
       return EC;