diff --git a/Lex/IdentifierTable.cpp b/Lex/IdentifierTable.cpp
new file mode 100644
index 0000000..e671af9
--- /dev/null
+++ b/Lex/IdentifierTable.cpp
@@ -0,0 +1,188 @@
+//===--- IdentifierTable.cpp - Hash table for identifier lookup -----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the IdentifierInfo, IdentifierVisitor, and
+// IdentifierTable interfaces.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Lex/IdentifierTable.h"
+#include "clang/Lex/MacroInfo.h"
+#include "clang/Basic/LangOptions.h"
+using namespace clang;
+
+//===----------------------------------------------------------------------===//
+// IdentifierInfo Implementation
+//===----------------------------------------------------------------------===//
+
+IdentifierInfo::IdentifierInfo() {
+  Macro = 0;
+  TokenID = tok::identifier;
+  PPID = tok::pp_not_keyword;
+  ObjCID = tok::objc_not_keyword;
+  BuiltinID = 0;
+  IsExtension = false;
+  IsPoisoned = false;
+  IsOtherTargetMacro = false;
+  IsCPPOperatorKeyword = false;
+  FETokenInfo = 0;
+}
+
+IdentifierInfo::~IdentifierInfo() {
+  delete Macro;
+}
+
+//===----------------------------------------------------------------------===//
+// IdentifierTable Implementation
+//===----------------------------------------------------------------------===//
+
+IdentifierTable::IdentifierTable(const LangOptions &LangOpts)
+  // Start with space for 8K identifiers.
+  : HashTable(8192) {
+
+  // Populate the identifier table with info about keywords for the current
+  // language.
+  AddKeywords(LangOpts);
+}
+
+//===----------------------------------------------------------------------===//
+// Language Keyword Implementation
+//===----------------------------------------------------------------------===//
+
+/// AddKeyword - This method is used to associate a token ID with specific
+/// identifiers because they are language keywords.  This causes the lexer to
+/// automatically map matching identifiers to specialized token codes.
+///
+/// The C90/C99/CPP flags are set to 0 if the token should be enabled in the
+/// specified langauge, set to 1 if it is an extension in the specified
+/// language, and set to 2 if disabled in the specified language.
+static void AddKeyword(const char *Keyword, unsigned KWLen,
+                       tok::TokenKind TokenCode,
+                       int C90, int C99, int CXX,
+                       const LangOptions &LangOpts, IdentifierTable &Table) {
+  int Flags = LangOpts.CPlusPlus ? CXX : (LangOpts.C99 ? C99 : C90);
+  
+  // Don't add this keyword if disabled in this language or if an extension
+  // and extensions are disabled.
+  if (Flags + LangOpts.NoExtensions >= 2) return;
+  
+  IdentifierInfo &Info = Table.get(Keyword, Keyword+KWLen);
+  Info.setTokenID(TokenCode);
+  Info.setIsExtensionToken(Flags == 1);
+}
+
+static void AddAlias(const char *Keyword, unsigned KWLen,
+                     const char *AliaseeKeyword, unsigned AliaseeKWLen,
+                     const LangOptions &LangOpts, IdentifierTable &Table) {
+  IdentifierInfo &AliasInfo = Table.get(Keyword, Keyword+KWLen);
+  IdentifierInfo &AliaseeInfo = Table.get(AliaseeKeyword,
+                                          AliaseeKeyword+AliaseeKWLen);
+  AliasInfo.setTokenID(AliaseeInfo.getTokenID());
+  AliasInfo.setIsExtensionToken(AliaseeInfo.isExtensionToken());
+}  
+
+/// AddPPKeyword - Register a preprocessor keyword like "define" "undef" or 
+/// "elif".
+static void AddPPKeyword(tok::PPKeywordKind PPID, 
+                         const char *Name, unsigned NameLen,
+                         IdentifierTable &Table) {
+  Table.get(Name, Name+NameLen).setPPKeywordID(PPID);
+}
+
+/// AddCXXOperatorKeyword - Register a C++ operator keyword alternative
+/// representations.
+static void AddCXXOperatorKeyword(const char *Keyword, unsigned KWLen,
+                                  tok::TokenKind TokenCode,
+                                  IdentifierTable &Table) {
+  IdentifierInfo &Info = Table.get(Keyword, Keyword + KWLen);
+  Info.setTokenID(TokenCode);
+  Info.setIsCPlusplusOperatorKeyword();
+}
+
+/// AddObjCKeyword - Register an Objective-C @keyword like "class" "selector" or 
+/// "property".
+static void AddObjCKeyword(tok::ObjCKeywordKind ObjCID, 
+                           const char *Name, unsigned NameLen,
+                           IdentifierTable &Table) {
+  Table.get(Name, Name+NameLen).setObjCKeywordID(ObjCID);
+}
+
+/// AddKeywords - Add all keywords to the symbol table.
+///
+void IdentifierTable::AddKeywords(const LangOptions &LangOpts) {
+  enum {
+    C90Shift = 0,
+    EXTC90   = 1 << C90Shift,
+    NOTC90   = 2 << C90Shift,
+    C99Shift = 2,
+    EXTC99   = 1 << C99Shift,
+    NOTC99   = 2 << C99Shift,
+    CPPShift = 4,
+    EXTCPP   = 1 << CPPShift,
+    NOTCPP   = 2 << CPPShift,
+    Mask     = 3
+  };
+  
+  // Add keywords and tokens for the current language.
+#define KEYWORD(NAME, FLAGS) \
+  AddKeyword(#NAME, strlen(#NAME), tok::kw_ ## NAME,  \
+             ((FLAGS) >> C90Shift) & Mask, \
+             ((FLAGS) >> C99Shift) & Mask, \
+             ((FLAGS) >> CPPShift) & Mask, LangOpts, *this);
+#define ALIAS(NAME, TOK) \
+  AddAlias(NAME, strlen(NAME), #TOK, strlen(#TOK), LangOpts, *this);
+#define PPKEYWORD(NAME) \
+  AddPPKeyword(tok::pp_##NAME, #NAME, strlen(#NAME), *this);
+#define CXX_KEYWORD_OPERATOR(NAME, ALIAS) \
+  if (LangOpts.CXXOperatorNames)          \
+    AddCXXOperatorKeyword(#NAME, strlen(#NAME), tok::ALIAS, *this);
+#define OBJC1_AT_KEYWORD(NAME) \
+  if (LangOpts.ObjC1)          \
+    AddObjCKeyword(tok::objc_##NAME, #NAME, strlen(#NAME), *this);
+#define OBJC2_AT_KEYWORD(NAME) \
+  if (LangOpts.ObjC2)          \
+    AddObjCKeyword(tok::objc_##NAME, #NAME, strlen(#NAME), *this);
+#include "clang/Basic/TokenKinds.def"
+}
+
+
+//===----------------------------------------------------------------------===//
+// Stats Implementation
+//===----------------------------------------------------------------------===//
+
+/// PrintStats - Print statistics about how well the identifier table is doing
+/// at hashing identifiers.
+void IdentifierTable::PrintStats() const {
+  unsigned NumBuckets = HashTable.getNumBuckets();
+  unsigned NumIdentifiers = HashTable.getNumItems();
+  unsigned NumEmptyBuckets = NumBuckets-NumIdentifiers;
+  unsigned AverageIdentifierSize = 0;
+  unsigned MaxIdentifierLength = 0;
+  
+  // TODO: Figure out maximum times an identifier had to probe for -stats.
+  for (llvm::StringMap<IdentifierInfo, llvm::BumpPtrAllocator>::const_iterator
+       I = HashTable.begin(), E = HashTable.end(); I != E; ++I) {
+    unsigned IdLen = I->getKeyLength();
+    AverageIdentifierSize += IdLen;
+    if (MaxIdentifierLength < IdLen)
+      MaxIdentifierLength = IdLen;
+  }
+  
+  fprintf(stderr, "\n*** Identifier Table Stats:\n");
+  fprintf(stderr, "# Identifiers:   %d\n", NumIdentifiers);
+  fprintf(stderr, "# Empty Buckets: %d\n", NumEmptyBuckets);
+  fprintf(stderr, "Hash density (#identifiers per bucket): %f\n",
+          NumIdentifiers/(double)NumBuckets);
+  fprintf(stderr, "Ave identifier length: %f\n",
+          (AverageIdentifierSize/(double)NumIdentifiers));
+  fprintf(stderr, "Max identifier length: %d\n", MaxIdentifierLength);
+  
+  // Compute statistics about the memory allocated for identifiers.
+  HashTable.getAllocator().PrintStats();
+}