Index: include/llvm/ADT/Triple.h
===================================================================
--- include/llvm/ADT/Triple.h
+++ include/llvm/ADT/Triple.h
@@ -146,6 +146,7 @@
   enum OSType {
     UnknownOS,
 
+    Ananas,
     CloudABI,
     Darwin,
     DragonFly,
Index: lib/Support/Triple.cpp
===================================================================
--- lib/Support/Triple.cpp
+++ lib/Support/Triple.cpp
@@ -171,6 +171,7 @@
   switch (Kind) {
   case UnknownOS: return "unknown";
 
+  case Ananas: return "ananas";
   case CloudABI: return "cloudabi";
   case Darwin: return "darwin";
   case DragonFly: return "dragonfly";
@@ -450,6 +451,7 @@
 
 static Triple::OSType parseOS(StringRef OSName) {
   return StringSwitch<Triple::OSType>(OSName)
+    .StartsWith("ananas", Triple::Ananas)
     .StartsWith("cloudabi", Triple::CloudABI)
     .StartsWith("darwin", Triple::Darwin)
     .StartsWith("dragonfly", Triple::DragonFly)
Index: unittests/ADT/TripleTest.cpp
===================================================================
--- unittests/ADT/TripleTest.cpp
+++ unittests/ADT/TripleTest.cpp
@@ -200,6 +200,12 @@
   EXPECT_EQ(Triple::UnknownVendor, T.getVendor());
   EXPECT_EQ(Triple::UnknownOS, T.getOS());
 
+  T = Triple("x86_64-unknown-ananas");
+  EXPECT_EQ(Triple::x86_64, T.getArch());
+  EXPECT_EQ(Triple::UnknownVendor, T.getVendor());
+  EXPECT_EQ(Triple::Ananas, T.getOS());
+  EXPECT_EQ(Triple::UnknownEnvironment, T.getEnvironment());
+
   T = Triple("x86_64-unknown-cloudabi");
   EXPECT_EQ(Triple::x86_64, T.getArch());
   EXPECT_EQ(Triple::UnknownVendor, T.getVendor());