Index: include/llvm/ADT/ImmutableList.h
===================================================================
--- include/llvm/ADT/ImmutableList.h
+++ include/llvm/ADT/ImmutableList.h
@@ -197,7 +197,7 @@
   }
 
   ImmutableList<T> create(const T& X) {
-    return Concat(X, getEmptyList());
+    return concat(X, getEmptyList());
   }
 };
 
Index: unittests/ADT/CMakeLists.txt
===================================================================
--- unittests/ADT/CMakeLists.txt
+++ unittests/ADT/CMakeLists.txt
@@ -28,6 +28,7 @@
   IListNodeTest.cpp
   IListSentinelTest.cpp
   IListTest.cpp
+  ImmutableListTest.cpp
   ImmutableMapTest.cpp
   ImmutableSetTest.cpp
   IntEqClassesTest.cpp
Index: unittests/ADT/ImmutableListTest.cpp
===================================================================
--- /dev/null
+++ unittests/ADT/ImmutableListTest.cpp
@@ -0,0 +1,198 @@
+//===--------- ImmutableListTest.cpp - ImmutableList unit tests --*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. Lee LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/ImmutableList.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+namespace {
+
+template <typename Fundamental> struct Wrapper : llvm::FoldingSetNode {
+  Fundamental F;
+
+  Wrapper(Fundamental F) : F(F) {}
+
+  operator Fundamental() const { return F; }
+
+  void Profile(FoldingSetNodeID &ID) const { ID.AddInteger(F); }
+};
+
+class ImmutableListTest : public testing::Test {};
+
+void concat(const ImmutableList<Wrapper<char>> &L, char *Buffer) {
+  int Index = 0;
+  for (ImmutableList<Wrapper<char>>::iterator It = L.begin(), End = L.end();
+       It != End; ++It) {
+    Buffer[Index++] = *It;
+  }
+  Buffer[Index] = '\0';
+}
+
+TEST_F(ImmutableListTest, EmptyIntListTest) {
+  ImmutableList<Wrapper<int>>::Factory f;
+
+  EXPECT_TRUE(f.getEmptyList() == f.getEmptyList());
+  EXPECT_TRUE(f.getEmptyList().isEqual(f.getEmptyList()));
+  EXPECT_TRUE(f.getEmptyList().isEmpty());
+
+  ImmutableList<Wrapper<int>> L = f.getEmptyList();
+  EXPECT_EQ(nullptr, L.getTail().getInternalPointer());
+  EXPECT_TRUE(L.getTail().isEmpty());
+  EXPECT_TRUE(L.begin() == L.end());
+}
+
+TEST_F(ImmutableListTest, OneElemIntListTest) {
+  ImmutableList<Wrapper<int>>::Factory f;
+  ImmutableList<Wrapper<int>> L = f.getEmptyList();
+
+  ImmutableList<Wrapper<int>> L2 = f.add(3, L);
+  EXPECT_TRUE(L.isEmpty());
+  EXPECT_FALSE(L2.isEmpty());
+  EXPECT_TRUE(L2.getTail().isEmpty());
+
+  EXPECT_FALSE(L == L2);
+  EXPECT_TRUE(L == L2.getTail());
+  EXPECT_FALSE(L.isEqual(L2));
+  EXPECT_TRUE(L.isEqual(L2.getTail()));
+  EXPECT_FALSE(L2.begin() == L2.end());
+  EXPECT_TRUE(L2.begin() != L2.end());
+
+  EXPECT_FALSE(L.contains(3));
+  EXPECT_EQ(3, L2.getHead());
+  EXPECT_TRUE(L2.contains(3));
+
+  ImmutableList<Wrapper<int>> L3 = f.add(2, L);
+  EXPECT_TRUE(L.isEmpty());
+  EXPECT_FALSE(L3.isEmpty());
+  EXPECT_FALSE(L == L3);
+  EXPECT_FALSE(L.contains(2));
+  EXPECT_TRUE(L3.contains(2));
+  EXPECT_EQ(2, L3.getHead());
+
+  EXPECT_FALSE(L2 == L3);
+  EXPECT_FALSE(L2.contains(2));
+}
+
+TEST_F(ImmutableListTest, CreatingIntListTest) {
+  ImmutableList<Wrapper<int>>::Factory f;
+
+  ImmutableList<Wrapper<int>> L = f.getEmptyList();
+  ImmutableList<Wrapper<int>> L2 = f.create(3);
+
+  EXPECT_FALSE(L2.isEmpty());
+  EXPECT_TRUE(L2.getTail().isEmpty());
+  EXPECT_EQ(3, L2.getHead());
+  EXPECT_TRUE(L.isEqual(L2.getTail()));
+  EXPECT_TRUE(L2.getTail().isEqual(L));
+}
+
+TEST_F(ImmutableListTest, MultiElemIntListTest) {
+  ImmutableList<Wrapper<int>>::Factory f;
+
+  ImmutableList<Wrapper<int>> L = f.getEmptyList();
+  ImmutableList<Wrapper<int>> L2 = f.add(5, f.add(4, f.add(3, L)));
+  ImmutableList<Wrapper<int>> L3 = f.add(43, f.add(20, f.add(9, L2)));
+  ImmutableList<Wrapper<int>> L4 = f.add(9, L2);
+  ImmutableList<Wrapper<int>> L5 = f.add(9, L2);
+
+  EXPECT_TRUE(L.isEmpty());
+  EXPECT_FALSE(L2.isEmpty());
+  EXPECT_FALSE(L3.isEmpty());
+  EXPECT_FALSE(L4.isEmpty());
+
+  EXPECT_FALSE(L.contains(3));
+  EXPECT_FALSE(L.contains(9));
+
+  EXPECT_TRUE(L2.contains(3));
+  EXPECT_TRUE(L2.contains(4));
+  EXPECT_TRUE(L2.contains(5));
+  EXPECT_FALSE(L2.contains(9));
+  EXPECT_FALSE(L2.contains(0));
+
+  EXPECT_EQ(5, L2.getHead());
+  EXPECT_EQ(4, L2.getTail().getHead());
+  EXPECT_EQ(3, L2.getTail().getTail().getHead());
+
+  EXPECT_TRUE(L3.contains(43));
+  EXPECT_TRUE(L3.contains(20));
+  EXPECT_TRUE(L3.contains(9));
+  EXPECT_TRUE(L3.contains(3));
+  EXPECT_TRUE(L3.contains(4));
+  EXPECT_TRUE(L3.contains(5));
+  EXPECT_FALSE(L3.contains(0));
+
+  EXPECT_EQ(43, L3.getHead());
+  EXPECT_EQ(20, L3.getTail().getHead());
+  EXPECT_EQ(9, L3.getTail().getTail().getHead());
+
+  EXPECT_TRUE(L3.getTail().getTail().getTail() == L2);
+  EXPECT_TRUE(L2 == L3.getTail().getTail().getTail());
+  EXPECT_TRUE(L3.getTail().getTail().getTail().isEqual(L2));
+  EXPECT_TRUE(L2.isEqual(L3.getTail().getTail().getTail()));
+
+  EXPECT_TRUE(L4.contains(9));
+  EXPECT_TRUE(L4.contains(3));
+  EXPECT_TRUE(L4.contains(4));
+  EXPECT_TRUE(L4.contains(5));
+  EXPECT_FALSE(L4.contains(20));
+  EXPECT_FALSE(L4.contains(43));
+  EXPECT_TRUE(L4.isEqual(L4));
+  EXPECT_TRUE(L4.isEqual(L5));
+
+  EXPECT_TRUE(L5.isEqual(L4));
+  EXPECT_TRUE(L5.isEqual(L5));
+}
+
+TEST_F(ImmutableListTest, CharListOrderingTest) {
+  ImmutableList<Wrapper<char>>::Factory f;
+  ImmutableList<Wrapper<char>> L = f.getEmptyList();
+
+  ImmutableList<Wrapper<char>> L2 = f.add('i', f.add('e', f.add('a', L)));
+  ImmutableList<Wrapper<char>> L3 = f.add('u', f.add('o', L2));
+
+  char Buffer[10];
+  concat(L3, Buffer);
+
+  ASSERT_STREQ("uoiea", Buffer);
+}
+
+TEST_F(ImmutableListTest, LongListOrderingTest) {
+  ImmutableList<Wrapper<long>>::Factory f;
+  ImmutableList<Wrapper<long>> L = f.getEmptyList();
+
+  ImmutableList<Wrapper<long>> L2 = f.add(3, f.add(4, f.add(5, L)));
+  ImmutableList<Wrapper<long>> L3 = f.add(0, f.add(1, f.add(2, L2)));
+
+  int i = 0;
+  for (ImmutableList<Wrapper<long>>::iterator I = L.begin(), E = L.end();
+       I != E; ++I) {
+    ASSERT_EQ(i, *I);
+    i++;
+  }
+  ASSERT_EQ(0, i);
+
+  i = 3;
+  for (ImmutableList<Wrapper<long>>::iterator I = L2.begin(), E = L2.end();
+       I != E; ++I) {
+    ASSERT_EQ(i, *I);
+    i++;
+  }
+  ASSERT_EQ(6, i);
+
+  i = 0;
+  for (ImmutableList<Wrapper<long>>::iterator I = L3.begin(), E = L3.end();
+       I != E; ++I) {
+    ASSERT_EQ(i, *I);
+    i++;
+  }
+  ASSERT_EQ(6, i);
+}
+
+} // namespace