Index: include/llvm/XRay/XRayRecord.h
===================================================================
--- include/llvm/XRay/XRayRecord.h
+++ include/llvm/XRay/XRayRecord.h
@@ -53,7 +53,7 @@
 /// This may or may not correspond to actual record types in the raw trace (as
 /// the loader implementation may synthesize this information in the process of
 /// of loading).
-enum class RecordTypes { ENTER, EXIT };
+enum class RecordTypes { ENTER, EXIT, TAIL_EXIT };
 
 struct XRayRecord {
   /// The type of record.
Index: include/llvm/XRay/YAMLXRayRecord.h
===================================================================
--- include/llvm/XRay/YAMLXRayRecord.h
+++ include/llvm/XRay/YAMLXRayRecord.h
@@ -54,6 +54,7 @@
   static void enumeration(IO &IO, xray::RecordTypes &Type) {
     IO.enumCase(Type, "function-enter", xray::RecordTypes::ENTER);
     IO.enumCase(Type, "function-exit", xray::RecordTypes::EXIT);
+    IO.enumCase(Type, "function-tail-exit", xray::RecordTypes::TAIL_EXIT);
   }
 };
 
Index: lib/XRay/Trace.cpp
===================================================================
--- lib/XRay/Trace.cpp
+++ lib/XRay/Trace.cpp
@@ -48,7 +48,7 @@
   FileHeader.NonstopTSC = Bitfield & 1uL << 1;
   FileHeader.CycleFrequency = HeaderExtractor.getU64(&OffsetPtr);
   std::memcpy(&FileHeader.FreeFormData, Data.bytes_begin() + OffsetPtr, 16);
-  if (FileHeader.Version != 1)
+  if (FileHeader.Version != 1 && FileHeader.Version != 2)
     return make_error<StringError>(
         Twine("Unsupported XRay file version: ") + Twine(FileHeader.Version),
         std::make_error_code(std::errc::invalid_argument));
@@ -94,6 +94,14 @@
     case 1:
       Record.Type = RecordTypes::EXIT;
       break;
+    case 2:
+      if (FileHeader.Version == 2)
+        Record.Type = RecordTypes::TAIL_EXIT;
+      else
+        return make_error<StringError>(
+            Twine("Unsupported record type: ") + Twine(int{Type}) +
+                "; Tail exits only supported in Version 2 of the log.",
+            std::make_error_code(std::errc::executable_format_error));
     default:
       return make_error<StringError>(
           Twine("Unknown record type '") + Twine(int{Type}) + "'",
@@ -320,8 +328,8 @@
       Record.Type = RecordTypes::ENTER;
       break;
     case static_cast<uint8_t>(RecordTypes::EXIT):
-    case 2: // TAIL_EXIT is not yet defined in RecordTypes.
-      Record.Type = RecordTypes::EXIT;
+    case 2:
+      Record.Type = RecordTypes::TAIL_EXIT;
       break;
     default:
       // Cast to an unsigned integer to not interpret the record type as a char.
@@ -443,7 +451,7 @@
   // Having iterated over everything we've been given, we've either consumed
   // everything and ended up in the end state, or were told to skip the rest.
   bool Finished = State.Expects == FDRState::Token::SCAN_TO_END_OF_THREAD_BUF &&
-        State.CurrentBufferSize == State.CurrentBufferConsumed;
+                  State.CurrentBufferSize == State.CurrentBufferConsumed;
   if (State.Expects != FDRState::Token::NEW_BUFFER_RECORD_OR_EOF && !Finished)
     return make_error<StringError>(
         Twine("Encountered EOF with unexpected state expectation ") +
@@ -535,8 +543,7 @@
 
   Trace T;
   if (Version == 1 && Type == NAIVE_FORMAT) {
-    if (auto E =
-            loadNaiveFormatLog(Data, T.FileHeader, T.Records))
+    if (auto E = loadNaiveFormatLog(Data, T.FileHeader, T.Records))
       return std::move(E);
   } else if (Version == 1 && Type == FLIGHT_DATA_RECORDER_FORMAT) {
     if (auto E = loadFDRLog(Data, T.FileHeader, T.Records))
Index: tools/llvm-xray/xray-account.cc
===================================================================
--- tools/llvm-xray/xray-account.cc
+++ tools/llvm-xray/xray-account.cc
@@ -150,7 +150,8 @@
     ThreadStack.emplace_back(Record.FuncId, Record.TSC);
     break;
   }
-  case RecordTypes::EXIT: {
+  case RecordTypes::EXIT:
+  case RecordTypes::TAIL_EXIT: {
     if (ThreadStack.empty())
       return false;
 
@@ -419,6 +420,9 @@
       case RecordTypes::EXIT:
         Stream << "exit";
         break;
+      case RecordTypes::TAIL_EXIT:
+        Stream << "tail-exit";
+        break;
     }
   }
 };
Index: tools/llvm-xray/xray-converter.cc
===================================================================
--- tools/llvm-xray/xray-converter.cc
+++ tools/llvm-xray/xray-converter.cc
@@ -128,6 +128,8 @@
     case RecordTypes::EXIT:
       Writer.write(uint8_t{1});
       break;
+    case RecordTypes::TAIL_EXIT:
+      Writer.write(uint8_t{2});
     }
     Writer.write(R.FuncId);
     Writer.write(R.TSC);
Index: tools/llvm-xray/xray-graph.cc
===================================================================
--- tools/llvm-xray/xray-graph.cc
+++ tools/llvm-xray/xray-graph.cc
@@ -214,7 +214,8 @@
     ThreadStack.push_back({Record.FuncId, Record.TSC});
     break;
   }
-  case RecordTypes::EXIT: {
+  case RecordTypes::EXIT:
+  case RecordTypes::TAIL_EXIT: {
     // FIXME: Refactor this and the account subcommand to reduce code
     // duplication
     if (ThreadStack.size() == 0 || ThreadStack.back().FuncId != Record.FuncId) {
Index: tools/llvm-xray/xray-stacks.cc
===================================================================
--- tools/llvm-xray/xray-stacks.cc
+++ tools/llvm-xray/xray-stacks.cc
@@ -352,7 +352,8 @@
       }
       return AccountRecordStatus::OK;
     }
-    case RecordTypes::EXIT: {
+    case RecordTypes::EXIT:
+    case RecordTypes::TAIL_EXIT: {
       bool wasLastRecordExit = state->wasLastRecordExit;
       state->wasLastRecordExit = true;
       // The exit case is more interesting, since we want to be able to deduce