Update aosp/master LLVM for rebase to r230699.

Change-Id: I2b5be30509658cb8266be782de0ab24f9099f9b9

39 files changed, 8933 insertions, 1235 deletions

diff --git a/examples/ExceptionDemo/ExceptionDemo.cpp b/examples/ExceptionDemo/ExceptionDemo.cpp
index 17076fa..317a326 100644
--- a/examples/ExceptionDemo/ExceptionDemo.cpp
+++ b/examples/ExceptionDemo/ExceptionDemo.cpp
@@ -56,8 +56,8 @@
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
-#include "llvm/PassManager.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Target/TargetOptions.h"
@@ -1122,14 +1122,11 @@ static llvm::BasicBlock *createCatchBlock(llvm::LLVMContext &context,
 /// @param numExceptionsToCatch length of exceptionTypesToCatch array
 /// @param exceptionTypesToCatch array of type info types to "catch"
 /// @returns generated function
-static
-llvm::Function *createCatchWrappedInvokeFunction(llvm::Module &module,
-                                             llvm::IRBuilder<> &builder,
-                                             llvm::FunctionPassManager &fpm,
-                                             llvm::Function &toInvoke,
-                                             std::string ourId,
-                                             unsigned numExceptionsToCatch,
-                                             unsigned exceptionTypesToCatch[]) {
+static llvm::Function *createCatchWrappedInvokeFunction(
+    llvm::Module &module, llvm::IRBuilder<> &builder,
+    llvm::legacy::FunctionPassManager &fpm, llvm::Function &toInvoke,
+    std::string ourId, unsigned numExceptionsToCatch,
+    unsigned exceptionTypesToCatch[]) {
 
   llvm::LLVMContext &context = module.getContext();
   llvm::Function *toPrint32Int = module.getFunction("print32Int");
@@ -1389,13 +1386,11 @@ llvm::Function *createCatchWrappedInvokeFunction(llvm::Module &module,
 /// @param nativeThrowFunct function which will throw a foreign exception
 ///        if the above nativeThrowType matches generated function's arg.
 /// @returns generated function
-static
-llvm::Function *createThrowExceptionFunction(llvm::Module &module,
-                                             llvm::IRBuilder<> &builder,
-                                             llvm::FunctionPassManager &fpm,
-                                             std::string ourId,
-                                             int32_t nativeThrowType,
-                                             llvm::Function &nativeThrowFunct) {
+static llvm::Function *
+createThrowExceptionFunction(llvm::Module &module, llvm::IRBuilder<> &builder,
+                             llvm::legacy::FunctionPassManager &fpm,
+                             std::string ourId, int32_t nativeThrowType,
+                             llvm::Function &nativeThrowFunct) {
   llvm::LLVMContext &context = module.getContext();
   namedValues.clear();
   ArgTypes unwindArgTypes;
@@ -1508,10 +1503,10 @@ static void createStandardUtilityFunctions(unsigned numTypeInfos,
 /// @param nativeThrowFunctName name of external function which will throw
 ///        a foreign exception
 /// @returns outermost generated test function.
-llvm::Function *createUnwindExceptionTest(llvm::Module &module,
-                                          llvm::IRBuilder<> &builder,
-                                          llvm::FunctionPassManager &fpm,
-                                          std::string nativeThrowFunctName) {
+llvm::Function *
+createUnwindExceptionTest(llvm::Module &module, llvm::IRBuilder<> &builder,
+                          llvm::legacy::FunctionPassManager &fpm,
+                          std::string nativeThrowFunctName) {
   // Number of type infos to generate
   unsigned numTypeInfos = 6;
 
@@ -1961,17 +1956,17 @@ int main(int argc, char *argv[]) {
       llvm::make_unique<llvm::Module>("my cool jit", context);
   llvm::Module *module = Owner.get();
 
-  llvm::RTDyldMemoryManager *MemMgr = new llvm::SectionMemoryManager();
+  std::unique_ptr<llvm::RTDyldMemoryManager> MemMgr(new llvm::SectionMemoryManager());
 
   // Build engine with JIT
   llvm::EngineBuilder factory(std::move(Owner));
   factory.setEngineKind(llvm::EngineKind::JIT);
   factory.setTargetOptions(Opts);
-  factory.setMCJITMemoryManager(MemMgr);
+  factory.setMCJITMemoryManager(std::move(MemMgr));
   llvm::ExecutionEngine *executionEngine = factory.create();
 
   {
-    llvm::FunctionPassManager fpm(module);
+    llvm::legacy::FunctionPassManager fpm(module);
 
     // Set up the optimizer pipeline.
     // Start with registering info about how the
diff --git a/examples/Kaleidoscope/CMakeLists.txt b/examples/Kaleidoscope/CMakeLists.txt
index 8c87ac5..32664aa 100644
--- a/examples/Kaleidoscope/CMakeLists.txt
+++ b/examples/Kaleidoscope/CMakeLists.txt
@@ -1,6 +1,16 @@
+add_custom_target(Kaleidoscope)
+set_target_properties(Kaleidoscope PROPERTIES FOLDER Examples)
+
+macro(add_kaleidoscope_chapter name)
+  add_dependencies(Kaleidoscope ${name})
+  add_llvm_example(${name} ${ARGN})
+endmacro(add_kaleidoscope_chapter name)
+
 add_subdirectory(Chapter2)
 add_subdirectory(Chapter3)
 add_subdirectory(Chapter4)
 add_subdirectory(Chapter5)
 add_subdirectory(Chapter6)
 add_subdirectory(Chapter7)
+add_subdirectory(Chapter8)
+add_subdirectory(Orc)
diff --git a/examples/Kaleidoscope/Chapter2/CMakeLists.txt b/examples/Kaleidoscope/Chapter2/CMakeLists.txt
index 79f2b17..fed3f4b 100644
--- a/examples/Kaleidoscope/Chapter2/CMakeLists.txt
+++ b/examples/Kaleidoscope/Chapter2/CMakeLists.txt
@@ -1,3 +1,3 @@
-add_llvm_example(Kaleidoscope-Ch2
+add_kaleidoscope_chapter(Kaleidoscope-Ch2
   toy.cpp
   )
diff --git a/examples/Kaleidoscope/Chapter3/CMakeLists.txt b/examples/Kaleidoscope/Chapter3/CMakeLists.txt
index a98d7df..8053c96 100644
--- a/examples/Kaleidoscope/Chapter3/CMakeLists.txt
+++ b/examples/Kaleidoscope/Chapter3/CMakeLists.txt
@@ -3,6 +3,6 @@ set(LLVM_LINK_COMPONENTS
   Support
   )
 
-add_llvm_example(Kaleidoscope-Ch3
+add_kaleidoscope_chapter(Kaleidoscope-Ch3
   toy.cpp
   )
diff --git a/examples/Kaleidoscope/Chapter4/CMakeLists.txt b/examples/Kaleidoscope/Chapter4/CMakeLists.txt
index 2f828dc..2c01e12 100644
--- a/examples/Kaleidoscope/Chapter4/CMakeLists.txt
+++ b/examples/Kaleidoscope/Chapter4/CMakeLists.txt
@@ -3,12 +3,14 @@ set(LLVM_LINK_COMPONENTS
   Core
   ExecutionEngine
   InstCombine
-  MC
+  MCJIT
+  RuntimeDyld
   ScalarOpts
   Support
-  nativecodegen
+  TransformUtils
+  native
   )
 
-add_llvm_example(Kaleidoscope-Ch4
+add_kaleidoscope_chapter(Kaleidoscope-Ch4
   toy.cpp
   )
diff --git a/examples/Kaleidoscope/Chapter4/toy.cpp b/examples/Kaleidoscope/Chapter4/toy.cpp
index 3564d75..70fe57f 100644
--- a/examples/Kaleidoscope/Chapter4/toy.cpp
+++ b/examples/Kaleidoscope/Chapter4/toy.cpp
@@ -1,12 +1,14 @@
 #include "llvm/Analysis/Passes.h"
 #include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/ExecutionEngine/MCJIT.h"
+#include "llvm/ExecutionEngine/SectionMemoryManager.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
-#include "llvm/PassManager.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Transforms/Scalar.h"
 #include <cctype>
@@ -26,14 +28,16 @@ enum Token {
   tok_eof = -1,
 
   // commands
-  tok_def = -2, tok_extern = -3,
+  tok_def = -2,
+  tok_extern = -3,
 
   // primary
-  tok_identifier = -4, tok_number = -5
+  tok_identifier = -4,
+  tok_number = -5
 };
 
-static std::string IdentifierStr;  // Filled in if tok_identifier
-static double NumVal;              // Filled in if tok_number
+static std::string IdentifierStr; // Filled in if tok_identifier
+static double NumVal;             // Filled in if tok_number
 
 /// gettok - Return the next token from standard input.
 static int gettok() {
@@ -48,12 +52,14 @@ static int gettok() {
     while (isalnum((LastChar = getchar())))
       IdentifierStr += LastChar;
 
-    if (IdentifierStr == "def") return tok_def;
-    if (IdentifierStr == "extern") return tok_extern;
+    if (IdentifierStr == "def")
+      return tok_def;
+    if (IdentifierStr == "extern")
+      return tok_extern;
     return tok_identifier;
   }
 
-  if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
+  if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
     std::string NumStr;
     do {
       NumStr += LastChar;
@@ -66,13 +72,14 @@ static int gettok() {
 
   if (LastChar == '#') {
     // Comment until end of line.
-    do LastChar = getchar();
+    do
+      LastChar = getchar();
     while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
-    
+
     if (LastChar != EOF)
       return gettok();
   }
-  
+
   // Check for end of file.  Don't eat the EOF.
   if (LastChar == EOF)
     return tok_eof;
@@ -97,6 +104,7 @@ public:
 /// NumberExprAST - Expression class for numeric literals like "1.0".
 class NumberExprAST : public ExprAST {
   double Val;
+
 public:
   NumberExprAST(double val) : Val(val) {}
   virtual Value *Codegen();
@@ -105,6 +113,7 @@ public:
 /// VariableExprAST - Expression class for referencing a variable, like "a".
 class VariableExprAST : public ExprAST {
   std::string Name;
+
 public:
   VariableExprAST(const std::string &name) : Name(name) {}
   virtual Value *Codegen();
@@ -114,19 +123,21 @@ public:
 class BinaryExprAST : public ExprAST {
   char Op;
   ExprAST *LHS, *RHS;
+
 public:
-  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) 
-    : Op(op), LHS(lhs), RHS(rhs) {}
+  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
+      : Op(op), LHS(lhs), RHS(rhs) {}
   virtual Value *Codegen();
 };
 
 /// CallExprAST - Expression class for function calls.
 class CallExprAST : public ExprAST {
   std::string Callee;
-  std::vector<ExprAST*> Args;
+  std::vector<ExprAST *> Args;
+
 public:
-  CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
-    : Callee(callee), Args(args) {}
+  CallExprAST(const std::string &callee, std::vector<ExprAST *> &args)
+      : Callee(callee), Args(args) {}
   virtual Value *Codegen();
 };
 
@@ -136,10 +147,11 @@ public:
 class PrototypeAST {
   std::string Name;
   std::vector<std::string> Args;
+
 public:
   PrototypeAST(const std::string &name, const std::vector<std::string> &args)
-    : Name(name), Args(args) {}
-  
+      : Name(name), Args(args) {}
+
   Function *Codegen();
 };
 
@@ -147,10 +159,10 @@ public:
 class FunctionAST {
   PrototypeAST *Proto;
   ExprAST *Body;
+
 public:
-  FunctionAST(PrototypeAST *proto, ExprAST *body)
-    : Proto(proto), Body(body) {}
-  
+  FunctionAST(PrototypeAST *proto, ExprAST *body) : Proto(proto), Body(body) {}
+
   Function *Codegen();
 };
 } // end anonymous namespace
@@ -163,9 +175,7 @@ public:
 /// token the parser is looking at.  getNextToken reads another token from the
 /// lexer and updates CurTok with its results.
 static int CurTok;
-static int getNextToken() {
-  return CurTok = gettok();
-}
+static int getNextToken() { return CurTok = gettok(); }
 
 /// BinopPrecedence - This holds the precedence for each binary operator that is
 /// defined.
@@ -175,17 +185,27 @@ static std::map<char, int> BinopPrecedence;
 static int GetTokPrecedence() {
   if (!isascii(CurTok))
     return -1;
-  
+
   // Make sure it's a declared binop.
   int TokPrec = BinopPrecedence[CurTok];
-  if (TokPrec <= 0) return -1;
+  if (TokPrec <= 0)
+    return -1;
   return TokPrec;
 }
 
 /// Error* - These are little helper functions for error handling.
-ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
-PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
-FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
+ExprAST *Error(const char *Str) {
+  fprintf(stderr, "Error: %s\n", Str);
+  return 0;
+}
+PrototypeAST *ErrorP(const char *Str) {
+  Error(Str);
+  return 0;
+}
+FunctionAST *ErrorF(const char *Str) {
+  Error(Str);
+  return 0;
+}
 
 static ExprAST *ParseExpression();
 
@@ -194,22 +214,24 @@ static ExprAST *ParseExpression();
 ///   ::= identifier '(' expression* ')'
 static ExprAST *ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
-  
-  getNextToken();  // eat identifier.
-  
+
+  getNextToken(); // eat identifier.
+
   if (CurTok != '(') // Simple variable ref.
     return new VariableExprAST(IdName);
-  
+
   // Call.
-  getNextToken();  // eat (
-  std::vector<ExprAST*> Args;
+  getNextToken(); // eat (
+  std::vector<ExprAST *> Args;
   if (CurTok != ')') {
     while (1) {
       ExprAST *Arg = ParseExpression();
-      if (!Arg) return 0;
+      if (!Arg)
+        return 0;
       Args.push_back(Arg);
 
-      if (CurTok == ')') break;
+      if (CurTok == ')')
+        break;
 
       if (CurTok != ',')
         return Error("Expected ')' or ',' in argument list");
@@ -219,7 +241,7 @@ static ExprAST *ParseIdentifierExpr() {
 
   // Eat the ')'.
   getNextToken();
-  
+
   return new CallExprAST(IdName, Args);
 }
 
@@ -232,13 +254,14 @@ static ExprAST *ParseNumberExpr() {
 
 /// parenexpr ::= '(' expression ')'
 static ExprAST *ParseParenExpr() {
-  getNextToken();  // eat (.
+  getNextToken(); // eat (.
   ExprAST *V = ParseExpression();
-  if (!V) return 0;
-  
+  if (!V)
+    return 0;
+
   if (CurTok != ')')
     return Error("expected ')'");
-  getNextToken();  // eat ).
+  getNextToken(); // eat ).
   return V;
 }
 
@@ -248,10 +271,14 @@ static ExprAST *ParseParenExpr() {
 ///   ::= parenexpr
 static ExprAST *ParsePrimary() {
   switch (CurTok) {
-  default: return Error("unknown token when expecting an expression");
-  case tok_identifier: return ParseIdentifierExpr();
-  case tok_number:     return ParseNumberExpr();
-  case '(':            return ParseParenExpr();
+  default:
+    return Error("unknown token when expecting an expression");
+  case tok_identifier:
+    return ParseIdentifierExpr();
+  case tok_number:
+    return ParseNumberExpr();
+  case '(':
+    return ParseParenExpr();
   }
 }
 
@@ -261,28 +288,30 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
   // If this is a binop, find its precedence.
   while (1) {
     int TokPrec = GetTokPrecedence();
-    
+
     // If this is a binop that binds at least as tightly as the current binop,
     // consume it, otherwise we are done.
     if (TokPrec < ExprPrec)
       return LHS;
-    
+
     // Okay, we know this is a binop.
     int BinOp = CurTok;
-    getNextToken();  // eat binop
-    
+    getNextToken(); // eat binop
+
     // Parse the primary expression after the binary operator.
     ExprAST *RHS = ParsePrimary();
-    if (!RHS) return 0;
-    
+    if (!RHS)
+      return 0;
+
     // If BinOp binds less tightly with RHS than the operator after RHS, let
     // the pending operator take RHS as its LHS.
     int NextPrec = GetTokPrecedence();
     if (TokPrec < NextPrec) {
-      RHS = ParseBinOpRHS(TokPrec+1, RHS);
-      if (RHS == 0) return 0;
+      RHS = ParseBinOpRHS(TokPrec + 1, RHS);
+      if (RHS == 0)
+        return 0;
     }
-    
+
     // Merge LHS/RHS.
     LHS = new BinaryExprAST(BinOp, LHS, RHS);
   }
@@ -293,8 +322,9 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
 ///
 static ExprAST *ParseExpression() {
   ExprAST *LHS = ParsePrimary();
-  if (!LHS) return 0;
-  
+  if (!LHS)
+    return 0;
+
   return ParseBinOpRHS(0, LHS);
 }
 
@@ -306,27 +336,28 @@ static PrototypeAST *ParsePrototype() {
 
   std::string FnName = IdentifierStr;
   getNextToken();
-  
+
   if (CurTok != '(')
     return ErrorP("Expected '(' in prototype");
-  
+
   std::vector<std::string> ArgNames;
   while (getNextToken() == tok_identifier)
     ArgNames.push_back(IdentifierStr);
   if (CurTok != ')')
     return ErrorP("Expected ')' in prototype");
-  
+
   // success.
-  getNextToken();  // eat ')'.
-  
+  getNextToken(); // eat ')'.
+
   return new PrototypeAST(FnName, ArgNames);
 }
 
 /// definition ::= 'def' prototype expression
 static FunctionAST *ParseDefinition() {
-  getNextToken();  // eat def.
+  getNextToken(); // eat def.
   PrototypeAST *Proto = ParsePrototype();
-  if (Proto == 0) return 0;
+  if (Proto == 0)
+    return 0;
 
   if (ExprAST *E = ParseExpression())
     return new FunctionAST(Proto, E);
@@ -345,20 +376,258 @@ static FunctionAST *ParseTopLevelExpr() {
 
 /// external ::= 'extern' prototype
 static PrototypeAST *ParseExtern() {
-  getNextToken();  // eat extern.
+  getNextToken(); // eat extern.
   return ParsePrototype();
 }
 
 //===----------------------------------------------------------------------===//
+// Quick and dirty hack
+//===----------------------------------------------------------------------===//
+
+// FIXME: Obviously we can do better than this
+std::string GenerateUniqueName(const char *root) {
+  static int i = 0;
+  char s[16];
+  sprintf(s, "%s%d", root, i++);
+  std::string S = s;
+  return S;
+}
+
+std::string MakeLegalFunctionName(std::string Name) {
+  std::string NewName;
+  if (!Name.length())
+    return GenerateUniqueName("anon_func_");
+
+  // Start with what we have
+  NewName = Name;
+
+  // Look for a numberic first character
+  if (NewName.find_first_of("0123456789") == 0) {
+    NewName.insert(0, 1, 'n');
+  }
+
+  // Replace illegal characters with their ASCII equivalent
+  std::string legal_elements =
+      "_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+  size_t pos;
+  while ((pos = NewName.find_first_not_of(legal_elements)) !=
+         std::string::npos) {
+    char old_c = NewName.at(pos);
+    char new_str[16];
+    sprintf(new_str, "%d", (int)old_c);
+    NewName = NewName.replace(pos, 1, new_str);
+  }
+
+  return NewName;
+}
+
+//===----------------------------------------------------------------------===//
+// MCJIT helper class
+//===----------------------------------------------------------------------===//
+
+class MCJITHelper {
+public:
+  MCJITHelper(LLVMContext &C) : Context(C), OpenModule(NULL) {}
+  ~MCJITHelper();
+
+  Function *getFunction(const std::string FnName);
+  Module *getModuleForNewFunction();
+  void *getPointerToFunction(Function *F);
+  void *getSymbolAddress(const std::string &Name);
+  void dump();
+
+private:
+  typedef std::vector<Module *> ModuleVector;
+  typedef std::vector<ExecutionEngine *> EngineVector;
+
+  LLVMContext &Context;
+  Module *OpenModule;
+  ModuleVector Modules;
+  EngineVector Engines;
+};
+
+class HelpingMemoryManager : public SectionMemoryManager {
+  HelpingMemoryManager(const HelpingMemoryManager &) = delete;
+  void operator=(const HelpingMemoryManager &) = delete;
+
+public:
+  HelpingMemoryManager(MCJITHelper *Helper) : MasterHelper(Helper) {}
+  virtual ~HelpingMemoryManager() {}
+
+  /// This method returns the address of the specified symbol.
+  /// Our implementation will attempt to find symbols in other
+  /// modules associated with the MCJITHelper to cross link symbols
+  /// from one generated module to another.
+  virtual uint64_t getSymbolAddress(const std::string &Name) override;
+
+private:
+  MCJITHelper *MasterHelper;
+};
+
+uint64_t HelpingMemoryManager::getSymbolAddress(const std::string &Name) {
+  uint64_t FnAddr = SectionMemoryManager::getSymbolAddress(Name);
+  if (FnAddr)
+    return FnAddr;
+
+  uint64_t HelperFun = (uint64_t)MasterHelper->getSymbolAddress(Name);
+  if (!HelperFun)
+    report_fatal_error("Program used extern function '" + Name +
+                       "' which could not be resolved!");
+
+  return HelperFun;
+}
+
+MCJITHelper::~MCJITHelper() {
+  if (OpenModule)
+    delete OpenModule;
+  EngineVector::iterator begin = Engines.begin();
+  EngineVector::iterator end = Engines.end();
+  EngineVector::iterator it;
+  for (it = begin; it != end; ++it)
+    delete *it;
+}
+
+Function *MCJITHelper::getFunction(const std::string FnName) {
+  ModuleVector::iterator begin = Modules.begin();
+  ModuleVector::iterator end = Modules.end();
+  ModuleVector::iterator it;
+  for (it = begin; it != end; ++it) {
+    Function *F = (*it)->getFunction(FnName);
+    if (F) {
+      if (*it == OpenModule)
+        return F;
+
+      assert(OpenModule != NULL);
+
+      // This function is in a module that has already been JITed.
+      // We need to generate a new prototype for external linkage.
+      Function *PF = OpenModule->getFunction(FnName);
+      if (PF && !PF->empty()) {
+        ErrorF("redefinition of function across modules");
+        return 0;
+      }
+
+      // If we don't have a prototype yet, create one.
+      if (!PF)
+        PF = Function::Create(F->getFunctionType(), Function::ExternalLinkage,
+                              FnName, OpenModule);
+      return PF;
+    }
+  }
+  return NULL;
+}
+
+Module *MCJITHelper::getModuleForNewFunction() {
+  // If we have a Module that hasn't been JITed, use that.
+  if (OpenModule)
+    return OpenModule;
+
+  // Otherwise create a new Module.
+  std::string ModName = GenerateUniqueName("mcjit_module_");
+  Module *M = new Module(ModName, Context);
+  Modules.push_back(M);
+  OpenModule = M;
+  return M;
+}
+
+void *MCJITHelper::getPointerToFunction(Function *F) {
+  // See if an existing instance of MCJIT has this function.
+  EngineVector::iterator begin = Engines.begin();
+  EngineVector::iterator end = Engines.end();
+  EngineVector::iterator it;
+  for (it = begin; it != end; ++it) {
+    void *P = (*it)->getPointerToFunction(F);
+    if (P)
+      return P;
+  }
+
+  // If we didn't find the function, see if we can generate it.
+  if (OpenModule) {
+    std::string ErrStr;
+    ExecutionEngine *NewEngine =
+        EngineBuilder(std::unique_ptr<Module>(OpenModule))
+            .setErrorStr(&ErrStr)
+            .setMCJITMemoryManager(std::unique_ptr<HelpingMemoryManager>(
+                new HelpingMemoryManager(this)))
+            .create();
+    if (!NewEngine) {
+      fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
+      exit(1);
+    }
+
+    // Create a function pass manager for this engine
+    auto *FPM = new legacy::FunctionPassManager(OpenModule);
+
+    // Set up the optimizer pipeline.  Start with registering info about how the
+    // target lays out data structures.
+    OpenModule->setDataLayout(NewEngine->getDataLayout());
+    FPM->add(new DataLayoutPass());
+    // Provide basic AliasAnalysis support for GVN.
+    FPM->add(createBasicAliasAnalysisPass());
+    // Promote allocas to registers.
+    FPM->add(createPromoteMemoryToRegisterPass());
+    // Do simple "peephole" optimizations and bit-twiddling optzns.
+    FPM->add(createInstructionCombiningPass());
+    // Reassociate expressions.
+    FPM->add(createReassociatePass());
+    // Eliminate Common SubExpressions.
+    FPM->add(createGVNPass());
+    // Simplify the control flow graph (deleting unreachable blocks, etc).
+    FPM->add(createCFGSimplificationPass());
+    FPM->doInitialization();
+
+    // For each function in the module
+    Module::iterator it;
+    Module::iterator end = OpenModule->end();
+    for (it = OpenModule->begin(); it != end; ++it) {
+      // Run the FPM on this function
+      FPM->run(*it);
+    }
+
+    // We don't need this anymore
+    delete FPM;
+
+    OpenModule = NULL;
+    Engines.push_back(NewEngine);
+    NewEngine->finalizeObject();
+    return NewEngine->getPointerToFunction(F);
+  }
+  return NULL;
+}
+
+void *MCJITHelper::getSymbolAddress(const std::string &Name) {
+  // Look for the symbol in each of our execution engines.
+  EngineVector::iterator begin = Engines.begin();
+  EngineVector::iterator end = Engines.end();
+  EngineVector::iterator it;
+  for (it = begin; it != end; ++it) {
+    uint64_t FAddr = (*it)->getFunctionAddress(Name);
+    if (FAddr) {
+      return (void *)FAddr;
+    }
+  }
+  return NULL;
+}
+
+void MCJITHelper::dump() {
+  ModuleVector::iterator begin = Modules.begin();
+  ModuleVector::iterator end = Modules.end();
+  ModuleVector::iterator it;
+  for (it = begin; it != end; ++it)
+    (*it)->dump();
+}
+//===----------------------------------------------------------------------===//
 // Code Generation
 //===----------------------------------------------------------------------===//
 
-static Module *TheModule;
+static MCJITHelper *JITHelper;
 static IRBuilder<> Builder(getGlobalContext());
-static std::map<std::string, Value*> NamedValues;
-static FunctionPassManager *TheFPM;
+static std::map<std::string, Value *> NamedValues;
 
-Value *ErrorV(const char *Str) { Error(Str); return 0; }
+Value *ErrorV(const char *Str) {
+  Error(Str);
+  return 0;
+}
 
 Value *NumberExprAST::Codegen() {
   return ConstantFP::get(getGlobalContext(), APFloat(Val));
@@ -373,93 +642,102 @@ Value *VariableExprAST::Codegen() {
 Value *BinaryExprAST::Codegen() {
   Value *L = LHS->Codegen();
   Value *R = RHS->Codegen();
-  if (L == 0 || R == 0) return 0;
-  
+  if (L == 0 || R == 0)
+    return 0;
+
   switch (Op) {
-  case '+': return Builder.CreateFAdd(L, R, "addtmp");
-  case '-': return Builder.CreateFSub(L, R, "subtmp");
-  case '*': return Builder.CreateFMul(L, R, "multmp");
+  case '+':
+    return Builder.CreateFAdd(L, R, "addtmp");
+  case '-':
+    return Builder.CreateFSub(L, R, "subtmp");
+  case '*':
+    return Builder.CreateFMul(L, R, "multmp");
   case '<':
     L = Builder.CreateFCmpULT(L, R, "cmptmp");
     // Convert bool 0/1 to double 0.0 or 1.0
     return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
                                 "booltmp");
-  default: return ErrorV("invalid binary operator");
+  default:
+    return ErrorV("invalid binary operator");
   }
 }
 
 Value *CallExprAST::Codegen() {
   // Look up the name in the global module table.
-  Function *CalleeF = TheModule->getFunction(Callee);
+  Function *CalleeF = JITHelper->getFunction(Callee);
   if (CalleeF == 0)
     return ErrorV("Unknown function referenced");
-  
+
   // If argument mismatch error.
   if (CalleeF->arg_size() != Args.size())
     return ErrorV("Incorrect # arguments passed");
 
-  std::vector<Value*> ArgsV;
+  std::vector<Value *> ArgsV;
   for (unsigned i = 0, e = Args.size(); i != e; ++i) {
     ArgsV.push_back(Args[i]->Codegen());
-    if (ArgsV.back() == 0) return 0;
+    if (ArgsV.back() == 0)
+      return 0;
   }
-  
+
   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 }
 
 Function *PrototypeAST::Codegen() {
   // Make the function type:  double(double,double) etc.
-  std::vector<Type*> Doubles(Args.size(),
-                             Type::getDoubleTy(getGlobalContext()));
-  FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
-                                       Doubles, false);
-  
-  Function *F = Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
-  
+  std::vector<Type *> Doubles(Args.size(),
+                              Type::getDoubleTy(getGlobalContext()));
+  FunctionType *FT =
+      FunctionType::get(Type::getDoubleTy(getGlobalContext()), Doubles, false);
+
+  std::string FnName = MakeLegalFunctionName(Name);
+
+  Module *M = JITHelper->getModuleForNewFunction();
+
+  Function *F = Function::Create(FT, Function::ExternalLinkage, FnName, M);
+
   // If F conflicted, there was already something named 'Name'.  If it has a
   // body, don't allow redefinition or reextern.
-  if (F->getName() != Name) {
+  if (F->getName() != FnName) {
     // Delete the one we just made and get the existing one.
     F->eraseFromParent();
-    F = TheModule->getFunction(Name);
-    
+    F = JITHelper->getFunction(Name);
     // If F already has a body, reject this.
     if (!F->empty()) {
       ErrorF("redefinition of function");
       return 0;
     }
-    
+
     // If F took a different number of args, reject.
     if (F->arg_size() != Args.size()) {
       ErrorF("redefinition of function with different # args");
       return 0;
     }
   }
-  
+
   // Set names for all arguments.
   unsigned Idx = 0;
   for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
        ++AI, ++Idx) {
     AI->setName(Args[Idx]);
-    
+
     // Add arguments to variable symbol table.
     NamedValues[Args[Idx]] = AI;
   }
-  
+
   return F;
 }
 
 Function *FunctionAST::Codegen() {
   NamedValues.clear();
-  
+
   Function *TheFunction = Proto->Codegen();
   if (TheFunction == 0)
     return 0;
-  
+
   // Create a new basic block to start insertion into.
   BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
   Builder.SetInsertPoint(BB);
-  
+
   if (Value *RetVal = Body->Codegen()) {
     // Finish off the function.
     Builder.CreateRet(RetVal);
@@ -467,12 +745,9 @@ Function *FunctionAST::Codegen() {
     // Validate the generated code, checking for consistency.
     verifyFunction(*TheFunction);
 
-    // Optimize the function.
-    TheFPM->run(*TheFunction);
-    
     return TheFunction;
   }
-  
+
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
   return 0;
@@ -482,8 +757,6 @@ Function *FunctionAST::Codegen() {
 // Top-Level parsing and JIT Driver
 //===----------------------------------------------------------------------===//
 
-static ExecutionEngine *TheExecutionEngine;
-
 static void HandleDefinition() {
   if (FunctionAST *F = ParseDefinition()) {
     if (Function *LF = F->Codegen()) {
@@ -513,8 +786,8 @@ static void HandleTopLevelExpression() {
   if (FunctionAST *F = ParseTopLevelExpr()) {
     if (Function *LF = F->Codegen()) {
       // JIT the function, returning a function pointer.
-      void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
-      
+      void *FPtr = JITHelper->getPointerToFunction(LF);
+
       // Cast it to the right type (takes no arguments, returns a double) so we
       // can call it as a native function.
       double (*FP)() = (double (*)())(intptr_t)FPtr;
@@ -531,11 +804,20 @@ static void MainLoop() {
   while (1) {
     fprintf(stderr, "ready> ");
     switch (CurTok) {
-    case tok_eof:    return;
-    case ';':        getNextToken(); break;  // ignore top-level semicolons.
-    case tok_def:    HandleDefinition(); break;
-    case tok_extern: HandleExtern(); break;
-    default:         HandleTopLevelExpression(); break;
+    case tok_eof:
+      return;
+    case ';':
+      getNextToken();
+      break; // ignore top-level semicolons.
+    case tok_def:
+      HandleDefinition();
+      break;
+    case tok_extern:
+      HandleExtern();
+      break;
+    default:
+      HandleTopLevelExpression();
+      break;
     }
   }
 }
@@ -545,8 +827,7 @@ static void MainLoop() {
 //===----------------------------------------------------------------------===//
 
 /// putchard - putchar that takes a double and returns 0.
-extern "C" 
-double putchard(double X) {
+extern "C" double putchard(double X) {
   putchar((char)X);
   return 0;
 }
@@ -557,61 +838,27 @@ double putchard(double X) {
 
 int main() {
   InitializeNativeTarget();
+  InitializeNativeTargetAsmPrinter();
+  InitializeNativeTargetAsmParser();
   LLVMContext &Context = getGlobalContext();
+  JITHelper = new MCJITHelper(Context);
 
   // Install standard binary operators.
   // 1 is lowest precedence.
   BinopPrecedence['<'] = 10;
   BinopPrecedence['+'] = 20;
   BinopPrecedence['-'] = 20;
-  BinopPrecedence['*'] = 40;  // highest.
+  BinopPrecedence['*'] = 40; // highest.
 
   // Prime the first token.
   fprintf(stderr, "ready> ");
   getNextToken();
 
-  // Make the module, which holds all the code.
-  std::unique_ptr<Module> Owner = make_unique<Module>("my cool jit", Context);
-  TheModule = Owner.get();
-
-  // Create the JIT.  This takes ownership of the module.
-  std::string ErrStr;
-  TheExecutionEngine =
-      EngineBuilder(std::move(Owner)).setErrorStr(&ErrStr).create();
-  if (!TheExecutionEngine) {
-    fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
-    exit(1);
-  }
-
-  FunctionPassManager OurFPM(TheModule);
-
-  // Set up the optimizer pipeline.  Start with registering info about how the
-  // target lays out data structures.
-  TheModule->setDataLayout(TheExecutionEngine->getDataLayout());
-  OurFPM.add(new DataLayoutPass());
-  // Provide basic AliasAnalysis support for GVN.
-  OurFPM.add(createBasicAliasAnalysisPass());
-  // Do simple "peephole" optimizations and bit-twiddling optzns.
-  OurFPM.add(createInstructionCombiningPass());
-  // Reassociate expressions.
-  OurFPM.add(createReassociatePass());
-  // Eliminate Common SubExpressions.
-  OurFPM.add(createGVNPass());
-  // Simplify the control flow graph (deleting unreachable blocks, etc).
-  OurFPM.add(createCFGSimplificationPass());
-
-  OurFPM.doInitialization();
-
-  // Set the global so the code gen can use this.
-  TheFPM = &OurFPM;
-
   // Run the main "interpreter loop" now.
   MainLoop();
 
-  TheFPM = 0;
-
   // Print out all of the generated code.
-  TheModule->dump();
+  JITHelper->dump();
 
   return 0;
 }
diff --git a/examples/Kaleidoscope/Chapter5/CMakeLists.txt b/examples/Kaleidoscope/Chapter5/CMakeLists.txt
index 1912ddc..aac9949 100644
--- a/examples/Kaleidoscope/Chapter5/CMakeLists.txt
+++ b/examples/Kaleidoscope/Chapter5/CMakeLists.txt
@@ -3,12 +3,12 @@ set(LLVM_LINK_COMPONENTS
   Core
   ExecutionEngine
   InstCombine
-  MC
+  MCJIT
   ScalarOpts
   Support
-  nativecodegen
+  native
   )
 
-add_llvm_example(Kaleidoscope-Ch5
+add_kaleidoscope_chapter(Kaleidoscope-Ch5
   toy.cpp
   )
diff --git a/examples/Kaleidoscope/Chapter5/toy.cpp b/examples/Kaleidoscope/Chapter5/toy.cpp
index 4929a20..728a2f5 100644
--- a/examples/Kaleidoscope/Chapter5/toy.cpp
+++ b/examples/Kaleidoscope/Chapter5/toy.cpp
@@ -1,12 +1,14 @@
 #include "llvm/Analysis/Passes.h"
 #include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/ExecutionEngine/MCJIT.h"
+#include "llvm/ExecutionEngine/SectionMemoryManager.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
-#include "llvm/PassManager.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Transforms/Scalar.h"
 #include <cctype>
@@ -26,18 +28,23 @@ enum Token {
   tok_eof = -1,
 
   // commands
-  tok_def = -2, tok_extern = -3,
+  tok_def = -2,
+  tok_extern = -3,
 
   // primary
-  tok_identifier = -4, tok_number = -5,
-  
+  tok_identifier = -4,
+  tok_number = -5,
+
   // control
-  tok_if = -6, tok_then = -7, tok_else = -8,
-  tok_for = -9, tok_in = -10
+  tok_if = -6,
+  tok_then = -7,
+  tok_else = -8,
+  tok_for = -9,
+  tok_in = -10
 };
 
-static std::string IdentifierStr;  // Filled in if tok_identifier
-static double NumVal;              // Filled in if tok_number
+static std::string IdentifierStr; // Filled in if tok_identifier
+static double NumVal;             // Filled in if tok_number
 
 /// gettok - Return the next token from standard input.
 static int gettok() {
@@ -52,17 +59,24 @@ static int gettok() {
     while (isalnum((LastChar = getchar())))
       IdentifierStr += LastChar;
 
-    if (IdentifierStr == "def") return tok_def;
-    if (IdentifierStr == "extern") return tok_extern;
-    if (IdentifierStr == "if") return tok_if;
-    if (IdentifierStr == "then") return tok_then;
-    if (IdentifierStr == "else") return tok_else;
-    if (IdentifierStr == "for") return tok_for;
-    if (IdentifierStr == "in") return tok_in;
+    if (IdentifierStr == "def")
+      return tok_def;
+    if (IdentifierStr == "extern")
+      return tok_extern;
+    if (IdentifierStr == "if")
+      return tok_if;
+    if (IdentifierStr == "then")
+      return tok_then;
+    if (IdentifierStr == "else")
+      return tok_else;
+    if (IdentifierStr == "for")
+      return tok_for;
+    if (IdentifierStr == "in")
+      return tok_in;
     return tok_identifier;
   }
 
-  if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
+  if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
     std::string NumStr;
     do {
       NumStr += LastChar;
@@ -75,13 +89,14 @@ static int gettok() {
 
   if (LastChar == '#') {
     // Comment until end of line.
-    do LastChar = getchar();
+    do
+      LastChar = getchar();
     while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
-    
+
     if (LastChar != EOF)
       return gettok();
   }
-  
+
   // Check for end of file.  Don't eat the EOF.
   if (LastChar == EOF)
     return tok_eof;
@@ -106,6 +121,7 @@ public:
 /// NumberExprAST - Expression class for numeric literals like "1.0".
 class NumberExprAST : public ExprAST {
   double Val;
+
 public:
   NumberExprAST(double val) : Val(val) {}
   virtual Value *Codegen();
@@ -114,6 +130,7 @@ public:
 /// VariableExprAST - Expression class for referencing a variable, like "a".
 class VariableExprAST : public ExprAST {
   std::string Name;
+
 public:
   VariableExprAST(const std::string &name) : Name(name) {}
   virtual Value *Codegen();
@@ -123,28 +140,31 @@ public:
 class BinaryExprAST : public ExprAST {
   char Op;
   ExprAST *LHS, *RHS;
+
 public:
-  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) 
-    : Op(op), LHS(lhs), RHS(rhs) {}
+  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
+      : Op(op), LHS(lhs), RHS(rhs) {}
   virtual Value *Codegen();
 };
 
 /// CallExprAST - Expression class for function calls.
 class CallExprAST : public ExprAST {
   std::string Callee;
-  std::vector<ExprAST*> Args;
+  std::vector<ExprAST *> Args;
+
 public:
-  CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
-    : Callee(callee), Args(args) {}
+  CallExprAST(const std::string &callee, std::vector<ExprAST *> &args)
+      : Callee(callee), Args(args) {}
   virtual Value *Codegen();
 };
 
 /// IfExprAST - Expression class for if/then/else.
 class IfExprAST : public ExprAST {
   ExprAST *Cond, *Then, *Else;
+
 public:
   IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
-  : Cond(cond), Then(then), Else(_else) {}
+      : Cond(cond), Then(then), Else(_else) {}
   virtual Value *Codegen();
 };
 
@@ -152,10 +172,11 @@ public:
 class ForExprAST : public ExprAST {
   std::string VarName;
   ExprAST *Start, *End, *Step, *Body;
+
 public:
   ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
              ExprAST *step, ExprAST *body)
-    : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
+      : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
   virtual Value *Codegen();
 };
 
@@ -165,10 +186,11 @@ public:
 class PrototypeAST {
   std::string Name;
   std::vector<std::string> Args;
+
 public:
   PrototypeAST(const std::string &name, const std::vector<std::string> &args)
-    : Name(name), Args(args) {}
-  
+      : Name(name), Args(args) {}
+
   Function *Codegen();
 };
 
@@ -176,10 +198,10 @@ public:
 class FunctionAST {
   PrototypeAST *Proto;
   ExprAST *Body;
+
 public:
-  FunctionAST(PrototypeAST *proto, ExprAST *body)
-    : Proto(proto), Body(body) {}
-  
+  FunctionAST(PrototypeAST *proto, ExprAST *body) : Proto(proto), Body(body) {}
+
   Function *Codegen();
 };
 } // end anonymous namespace
@@ -192,9 +214,7 @@ public:
 /// token the parser is looking at.  getNextToken reads another token from the
 /// lexer and updates CurTok with its results.
 static int CurTok;
-static int getNextToken() {
-  return CurTok = gettok();
-}
+static int getNextToken() { return CurTok = gettok(); }
 
 /// BinopPrecedence - This holds the precedence for each binary operator that is
 /// defined.
@@ -204,17 +224,27 @@ static std::map<char, int> BinopPrecedence;
 static int GetTokPrecedence() {
   if (!isascii(CurTok))
     return -1;
-  
+
   // Make sure it's a declared binop.
   int TokPrec = BinopPrecedence[CurTok];
-  if (TokPrec <= 0) return -1;
+  if (TokPrec <= 0)
+    return -1;
   return TokPrec;
 }
 
 /// Error* - These are little helper functions for error handling.
-ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
-PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
-FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
+ExprAST *Error(const char *Str) {
+  fprintf(stderr, "Error: %s\n", Str);
+  return 0;
+}
+PrototypeAST *ErrorP(const char *Str) {
+  Error(Str);
+  return 0;
+}
+FunctionAST *ErrorF(const char *Str) {
+  Error(Str);
+  return 0;
+}
 
 static ExprAST *ParseExpression();
 
@@ -223,22 +253,24 @@ static ExprAST *ParseExpression();
 ///   ::= identifier '(' expression* ')'
 static ExprAST *ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
-  
-  getNextToken();  // eat identifier.
-  
+
+  getNextToken(); // eat identifier.
+
   if (CurTok != '(') // Simple variable ref.
     return new VariableExprAST(IdName);
-  
+
   // Call.
-  getNextToken();  // eat (
-  std::vector<ExprAST*> Args;
+  getNextToken(); // eat (
+  std::vector<ExprAST *> Args;
   if (CurTok != ')') {
     while (1) {
       ExprAST *Arg = ParseExpression();
-      if (!Arg) return 0;
+      if (!Arg)
+        return 0;
       Args.push_back(Arg);
 
-      if (CurTok == ')') break;
+      if (CurTok == ')')
+        break;
 
       if (CurTok != ',')
         return Error("Expected ')' or ',' in argument list");
@@ -248,7 +280,7 @@ static ExprAST *ParseIdentifierExpr() {
 
   // Eat the ')'.
   getNextToken();
-  
+
   return new CallExprAST(IdName, Args);
 }
 
@@ -261,80 +293,87 @@ static ExprAST *ParseNumberExpr() {
 
 /// parenexpr ::= '(' expression ')'
 static ExprAST *ParseParenExpr() {
-  getNextToken();  // eat (.
+  getNextToken(); // eat (.
   ExprAST *V = ParseExpression();
-  if (!V) return 0;
-  
+  if (!V)
+    return 0;
+
   if (CurTok != ')')
     return Error("expected ')'");
-  getNextToken();  // eat ).
+  getNextToken(); // eat ).
   return V;
 }
 
 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
 static ExprAST *ParseIfExpr() {
-  getNextToken();  // eat the if.
-  
+  getNextToken(); // eat the if.
+
   // condition.
   ExprAST *Cond = ParseExpression();
-  if (!Cond) return 0;
-  
+  if (!Cond)
+    return 0;
+
   if (CurTok != tok_then)
     return Error("expected then");
-  getNextToken();  // eat the then
-  
+  getNextToken(); // eat the then
+
   ExprAST *Then = ParseExpression();
-  if (Then == 0) return 0;
-  
+  if (Then == 0)
+    return 0;
+
   if (CurTok != tok_else)
     return Error("expected else");
-  
+
   getNextToken();
-  
+
   ExprAST *Else = ParseExpression();
-  if (!Else) return 0;
-  
+  if (!Else)
+    return 0;
+
   return new IfExprAST(Cond, Then, Else);
 }
 
 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
 static ExprAST *ParseForExpr() {
-  getNextToken();  // eat the for.
+  getNextToken(); // eat the for.
 
   if (CurTok != tok_identifier)
     return Error("expected identifier after for");
-  
+
   std::string IdName = IdentifierStr;
-  getNextToken();  // eat identifier.
-  
+  getNextToken(); // eat identifier.
+
   if (CurTok != '=')
     return Error("expected '=' after for");
-  getNextToken();  // eat '='.
-  
-  
+  getNextToken(); // eat '='.
+
   ExprAST *Start = ParseExpression();
-  if (Start == 0) return 0;
+  if (Start == 0)
+    return 0;
   if (CurTok != ',')
     return Error("expected ',' after for start value");
   getNextToken();
-  
+
   ExprAST *End = ParseExpression();
-  if (End == 0) return 0;
-  
+  if (End == 0)
+    return 0;
+
   // The step value is optional.
   ExprAST *Step = 0;
   if (CurTok == ',') {
     getNextToken();
     Step = ParseExpression();
-    if (Step == 0) return 0;
+    if (Step == 0)
+      return 0;
   }
-  
+
   if (CurTok != tok_in)
     return Error("expected 'in' after for");
-  getNextToken();  // eat 'in'.
-  
+  getNextToken(); // eat 'in'.
+
   ExprAST *Body = ParseExpression();
-  if (Body == 0) return 0;
+  if (Body == 0)
+    return 0;
 
   return new ForExprAST(IdName, Start, End, Step, Body);
 }
@@ -347,12 +386,18 @@ static ExprAST *ParseForExpr() {
 ///   ::= forexpr
 static ExprAST *ParsePrimary() {
   switch (CurTok) {
-  default: return Error("unknown token when expecting an expression");
-  case tok_identifier: return ParseIdentifierExpr();
-  case tok_number:     return ParseNumberExpr();
-  case '(':            return ParseParenExpr();
-  case tok_if:         return ParseIfExpr();
-  case tok_for:        return ParseForExpr();
+  default:
+    return Error("unknown token when expecting an expression");
+  case tok_identifier:
+    return ParseIdentifierExpr();
+  case tok_number:
+    return ParseNumberExpr();
+  case '(':
+    return ParseParenExpr();
+  case tok_if:
+    return ParseIfExpr();
+  case tok_for:
+    return ParseForExpr();
   }
 }
 
@@ -362,28 +407,30 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
   // If this is a binop, find its precedence.
   while (1) {
     int TokPrec = GetTokPrecedence();
-    
+
     // If this is a binop that binds at least as tightly as the current binop,
     // consume it, otherwise we are done.
     if (TokPrec < ExprPrec)
       return LHS;
-    
+
     // Okay, we know this is a binop.
     int BinOp = CurTok;
-    getNextToken();  // eat binop
-    
+    getNextToken(); // eat binop
+
     // Parse the primary expression after the binary operator.
     ExprAST *RHS = ParsePrimary();
-    if (!RHS) return 0;
-    
+    if (!RHS)
+      return 0;
+
     // If BinOp binds less tightly with RHS than the operator after RHS, let
     // the pending operator take RHS as its LHS.
     int NextPrec = GetTokPrecedence();
     if (TokPrec < NextPrec) {
-      RHS = ParseBinOpRHS(TokPrec+1, RHS);
-      if (RHS == 0) return 0;
+      RHS = ParseBinOpRHS(TokPrec + 1, RHS);
+      if (RHS == 0)
+        return 0;
     }
-    
+
     // Merge LHS/RHS.
     LHS = new BinaryExprAST(BinOp, LHS, RHS);
   }
@@ -394,8 +441,9 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
 ///
 static ExprAST *ParseExpression() {
   ExprAST *LHS = ParsePrimary();
-  if (!LHS) return 0;
-  
+  if (!LHS)
+    return 0;
+
   return ParseBinOpRHS(0, LHS);
 }
 
@@ -407,27 +455,28 @@ static PrototypeAST *ParsePrototype() {
 
   std::string FnName = IdentifierStr;
   getNextToken();
-  
+
   if (CurTok != '(')
     return ErrorP("Expected '(' in prototype");
-  
+
   std::vector<std::string> ArgNames;
   while (getNextToken() == tok_identifier)
     ArgNames.push_back(IdentifierStr);
   if (CurTok != ')')
     return ErrorP("Expected ')' in prototype");
-  
+
   // success.
-  getNextToken();  // eat ')'.
-  
+  getNextToken(); // eat ')'.
+
   return new PrototypeAST(FnName, ArgNames);
 }
 
 /// definition ::= 'def' prototype expression
 static FunctionAST *ParseDefinition() {
-  getNextToken();  // eat def.
+  getNextToken(); // eat def.
   PrototypeAST *Proto = ParsePrototype();
-  if (Proto == 0) return 0;
+  if (Proto == 0)
+    return 0;
 
   if (ExprAST *E = ParseExpression())
     return new FunctionAST(Proto, E);
@@ -446,7 +495,7 @@ static FunctionAST *ParseTopLevelExpr() {
 
 /// external ::= 'extern' prototype
 static PrototypeAST *ParseExtern() {
-  getNextToken();  // eat extern.
+  getNextToken(); // eat extern.
   return ParsePrototype();
 }
 
@@ -456,10 +505,13 @@ static PrototypeAST *ParseExtern() {
 
 static Module *TheModule;
 static IRBuilder<> Builder(getGlobalContext());
-static std::map<std::string, Value*> NamedValues;
-static FunctionPassManager *TheFPM;
+static std::map<std::string, Value *> NamedValues;
+static legacy::FunctionPassManager *TheFPM;
 
-Value *ErrorV(const char *Str) { Error(Str); return 0; }
+Value *ErrorV(const char *Str) {
+  Error(Str);
+  return 0;
+}
 
 Value *NumberExprAST::Codegen() {
   return ConstantFP::get(getGlobalContext(), APFloat(Val));
@@ -474,18 +526,23 @@ Value *VariableExprAST::Codegen() {
 Value *BinaryExprAST::Codegen() {
   Value *L = LHS->Codegen();
   Value *R = RHS->Codegen();
-  if (L == 0 || R == 0) return 0;
-  
+  if (L == 0 || R == 0)
+    return 0;
+
   switch (Op) {
-  case '+': return Builder.CreateFAdd(L, R, "addtmp");
-  case '-': return Builder.CreateFSub(L, R, "subtmp");
-  case '*': return Builder.CreateFMul(L, R, "multmp");
+  case '+':
+    return Builder.CreateFAdd(L, R, "addtmp");
+  case '-':
+    return Builder.CreateFSub(L, R, "subtmp");
+  case '*':
+    return Builder.CreateFMul(L, R, "multmp");
   case '<':
     L = Builder.CreateFCmpULT(L, R, "cmptmp");
     // Convert bool 0/1 to double 0.0 or 1.0
     return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
                                 "booltmp");
-  default: return ErrorV("invalid binary operator");
+  default:
+    return ErrorV("invalid binary operator");
   }
 }
 
@@ -494,66 +551,70 @@ Value *CallExprAST::Codegen() {
   Function *CalleeF = TheModule->getFunction(Callee);
   if (CalleeF == 0)
     return ErrorV("Unknown function referenced");
-  
+
   // If argument mismatch error.
   if (CalleeF->arg_size() != Args.size())
     return ErrorV("Incorrect # arguments passed");
 
-  std::vector<Value*> ArgsV;
+  std::vector<Value *> ArgsV;
   for (unsigned i = 0, e = Args.size(); i != e; ++i) {
     ArgsV.push_back(Args[i]->Codegen());
-    if (ArgsV.back() == 0) return 0;
+    if (ArgsV.back() == 0)
+      return 0;
   }
-  
+
   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 }
 
 Value *IfExprAST::Codegen() {
   Value *CondV = Cond->Codegen();
-  if (CondV == 0) return 0;
-  
+  if (CondV == 0)
+    return 0;
+
   // Convert condition to a bool by comparing equal to 0.0.
-  CondV = Builder.CreateFCmpONE(CondV, 
-                              ConstantFP::get(getGlobalContext(), APFloat(0.0)),
-                                "ifcond");
-  
+  CondV = Builder.CreateFCmpONE(
+      CondV, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "ifcond");
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
-  
+
   // Create blocks for the then and else cases.  Insert the 'then' block at the
   // end of the function.
-  BasicBlock *ThenBB = BasicBlock::Create(getGlobalContext(), "then", TheFunction);
+  BasicBlock *ThenBB =
+      BasicBlock::Create(getGlobalContext(), "then", TheFunction);
   BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
   BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
-  
+
   Builder.CreateCondBr(CondV, ThenBB, ElseBB);
-  
+
   // Emit then value.
   Builder.SetInsertPoint(ThenBB);
-  
+
   Value *ThenV = Then->Codegen();
-  if (ThenV == 0) return 0;
-  
+  if (ThenV == 0)
+    return 0;
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
   ThenBB = Builder.GetInsertBlock();
-  
+
   // Emit else block.
   TheFunction->getBasicBlockList().push_back(ElseBB);
   Builder.SetInsertPoint(ElseBB);
-  
+
   Value *ElseV = Else->Codegen();
-  if (ElseV == 0) return 0;
-  
+  if (ElseV == 0)
+    return 0;
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
   ElseBB = Builder.GetInsertBlock();
-  
+
   // Emit merge block.
   TheFunction->getBasicBlockList().push_back(MergeBB);
   Builder.SetInsertPoint(MergeBB);
-  PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
-                                  "iftmp");
-  
+  PHINode *PN =
+      Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, "iftmp");
+
   PN->addIncoming(ThenV, ThenBB);
   PN->addIncoming(ElseV, ElseBB);
   return PN;
@@ -564,7 +625,7 @@ Value *ForExprAST::Codegen() {
   //   ...
   //   start = startexpr
   //   goto loop
-  // loop: 
+  // loop:
   //   variable = phi [start, loopheader], [nextvariable, loopend]
   //   ...
   //   bodyexpr
@@ -575,136 +636,141 @@ Value *ForExprAST::Codegen() {
   //   endcond = endexpr
   //   br endcond, loop, endloop
   // outloop:
-  
+
   // Emit the start code first, without 'variable' in scope.
   Value *StartVal = Start->Codegen();
-  if (StartVal == 0) return 0;
-  
+  if (StartVal == 0)
+    return 0;
+
   // Make the new basic block for the loop header, inserting after current
   // block.
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
   BasicBlock *PreheaderBB = Builder.GetInsertBlock();
-  BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
-  
+  BasicBlock *LoopBB =
+      BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
+
   // Insert an explicit fall through from the current block to the LoopBB.
   Builder.CreateBr(LoopBB);
 
   // Start insertion in LoopBB.
   Builder.SetInsertPoint(LoopBB);
-  
+
   // Start the PHI node with an entry for Start.
-  PHINode *Variable = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, VarName.c_str());
+  PHINode *Variable = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()),
+                                        2, VarName.c_str());
   Variable->addIncoming(StartVal, PreheaderBB);
-  
+
   // Within the loop, the variable is defined equal to the PHI node.  If it
   // shadows an existing variable, we have to restore it, so save it now.
   Value *OldVal = NamedValues[VarName];
   NamedValues[VarName] = Variable;
-  
+
   // Emit the body of the loop.  This, like any other expr, can change the
   // current BB.  Note that we ignore the value computed by the body, but don't
   // allow an error.
   if (Body->Codegen() == 0)
     return 0;
-  
+
   // Emit the step value.
   Value *StepVal;
   if (Step) {
     StepVal = Step->Codegen();
-    if (StepVal == 0) return 0;
+    if (StepVal == 0)
+      return 0;
   } else {
     // If not specified, use 1.0.
     StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
   }
-  
+
   Value *NextVar = Builder.CreateFAdd(Variable, StepVal, "nextvar");
 
   // Compute the end condition.
   Value *EndCond = End->Codegen();
-  if (EndCond == 0) return EndCond;
-  
+  if (EndCond == 0)
+    return EndCond;
+
   // Convert condition to a bool by comparing equal to 0.0.
-  EndCond = Builder.CreateFCmpONE(EndCond, 
-                              ConstantFP::get(getGlobalContext(), APFloat(0.0)),
-                                  "loopcond");
-  
+  EndCond = Builder.CreateFCmpONE(
+      EndCond, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "loopcond");
+
   // Create the "after loop" block and insert it.
   BasicBlock *LoopEndBB = Builder.GetInsertBlock();
-  BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
-  
+  BasicBlock *AfterBB =
+      BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
+
   // Insert the conditional branch into the end of LoopEndBB.
   Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
-  
+
   // Any new code will be inserted in AfterBB.
   Builder.SetInsertPoint(AfterBB);
-  
+
   // Add a new entry to the PHI node for the backedge.
   Variable->addIncoming(NextVar, LoopEndBB);
-  
+
   // Restore the unshadowed variable.
   if (OldVal)
     NamedValues[VarName] = OldVal;
   else
     NamedValues.erase(VarName);
 
-  
   // for expr always returns 0.0.
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
 
 Function *PrototypeAST::Codegen() {
   // Make the function type:  double(double,double) etc.
-  std::vector<Type*> Doubles(Args.size(),
-                             Type::getDoubleTy(getGlobalContext()));
-  FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
-                                       Doubles, false);
-  
-  Function *F = Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
-  
+  std::vector<Type *> Doubles(Args.size(),
+                              Type::getDoubleTy(getGlobalContext()));
+  FunctionType *FT =
+      FunctionType::get(Type::getDoubleTy(getGlobalContext()), Doubles, false);
+
+  Function *F =
+      Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
+
   // If F conflicted, there was already something named 'Name'.  If it has a
   // body, don't allow redefinition or reextern.
   if (F->getName() != Name) {
     // Delete the one we just made and get the existing one.
     F->eraseFromParent();
     F = TheModule->getFunction(Name);
-    
+
     // If F already has a body, reject this.
     if (!F->empty()) {
       ErrorF("redefinition of function");
       return 0;
     }
-    
+
     // If F took a different number of args, reject.
     if (F->arg_size() != Args.size()) {
       ErrorF("redefinition of function with different # args");
       return 0;
     }
   }
-  
+
   // Set names for all arguments.
   unsigned Idx = 0;
   for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
        ++AI, ++Idx) {
     AI->setName(Args[Idx]);
-    
+
     // Add arguments to variable symbol table.
     NamedValues[Args[Idx]] = AI;
   }
-  
+
   return F;
 }
 
 Function *FunctionAST::Codegen() {
   NamedValues.clear();
-  
+
   Function *TheFunction = Proto->Codegen();
   if (TheFunction == 0)
     return 0;
-  
+
   // Create a new basic block to start insertion into.
   BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
   Builder.SetInsertPoint(BB);
-  
+
   if (Value *RetVal = Body->Codegen()) {
     // Finish off the function.
     Builder.CreateRet(RetVal);
@@ -714,10 +780,10 @@ Function *FunctionAST::Codegen() {
 
     // Optimize the function.
     TheFPM->run(*TheFunction);
-    
+
     return TheFunction;
   }
-  
+
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
   return 0;
@@ -757,9 +823,10 @@ static void HandleTopLevelExpression() {
   // Evaluate a top-level expression into an anonymous function.
   if (FunctionAST *F = ParseTopLevelExpr()) {
     if (Function *LF = F->Codegen()) {
+      TheExecutionEngine->finalizeObject();
       // JIT the function, returning a function pointer.
       void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
-      
+
       // Cast it to the right type (takes no arguments, returns a double) so we
       // can call it as a native function.
       double (*FP)() = (double (*)())(intptr_t)FPtr;
@@ -776,11 +843,20 @@ static void MainLoop() {
   while (1) {
     fprintf(stderr, "ready> ");
     switch (CurTok) {
-    case tok_eof:    return;
-    case ';':        getNextToken(); break;  // ignore top-level semicolons.
-    case tok_def:    HandleDefinition(); break;
-    case tok_extern: HandleExtern(); break;
-    default:         HandleTopLevelExpression(); break;
+    case tok_eof:
+      return;
+    case ';':
+      getNextToken();
+      break; // ignore top-level semicolons.
+    case tok_def:
+      HandleDefinition();
+      break;
+    case tok_extern:
+      HandleExtern();
+      break;
+    default:
+      HandleTopLevelExpression();
+      break;
     }
   }
 }
@@ -790,8 +866,7 @@ static void MainLoop() {
 //===----------------------------------------------------------------------===//
 
 /// putchard - putchar that takes a double and returns 0.
-extern "C" 
-double putchard(double X) {
+extern "C" double putchard(double X) {
   putchar((char)X);
   return 0;
 }
@@ -802,6 +877,8 @@ double putchard(double X) {
 
 int main() {
   InitializeNativeTarget();
+  InitializeNativeTargetAsmPrinter();
+  InitializeNativeTargetAsmParser();
   LLVMContext &Context = getGlobalContext();
 
   // Install standard binary operators.
@@ -809,7 +886,7 @@ int main() {
   BinopPrecedence['<'] = 10;
   BinopPrecedence['+'] = 20;
   BinopPrecedence['-'] = 20;
-  BinopPrecedence['*'] = 40;  // highest.
+  BinopPrecedence['*'] = 40; // highest.
 
   // Prime the first token.
   fprintf(stderr, "ready> ");
@@ -822,13 +899,16 @@ int main() {
   // Create the JIT.  This takes ownership of the module.
   std::string ErrStr;
   TheExecutionEngine =
-      EngineBuilder(std::move(Owner)).setErrorStr(&ErrStr).create();
+      EngineBuilder(std::move(Owner))
+          .setErrorStr(&ErrStr)
+          .setMCJITMemoryManager(llvm::make_unique<SectionMemoryManager>())
+          .create();
   if (!TheExecutionEngine) {
     fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
     exit(1);
   }
 
-  FunctionPassManager OurFPM(TheModule);
+  legacy::FunctionPassManager OurFPM(TheModule);
 
   // Set up the optimizer pipeline.  Start with registering info about how the
   // target lays out data structures.
diff --git a/examples/Kaleidoscope/Chapter6/CMakeLists.txt b/examples/Kaleidoscope/Chapter6/CMakeLists.txt
index d36f030..55b9a78 100644
--- a/examples/Kaleidoscope/Chapter6/CMakeLists.txt
+++ b/examples/Kaleidoscope/Chapter6/CMakeLists.txt
@@ -3,12 +3,12 @@ set(LLVM_LINK_COMPONENTS
   Core
   ExecutionEngine
   InstCombine
-  MC
+  MCJIT
   ScalarOpts
   Support
-  nativecodegen
+  native
   )
 
-add_llvm_example(Kaleidoscope-Ch6
+add_kaleidoscope_chapter(Kaleidoscope-Ch6
   toy.cpp
   )
diff --git a/examples/Kaleidoscope/Chapter6/toy.cpp b/examples/Kaleidoscope/Chapter6/toy.cpp
index 06da9ac..8131aa1 100644
--- a/examples/Kaleidoscope/Chapter6/toy.cpp
+++ b/examples/Kaleidoscope/Chapter6/toy.cpp
@@ -1,12 +1,14 @@
 #include "llvm/Analysis/Passes.h"
 #include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/ExecutionEngine/MCJIT.h"
+#include "llvm/ExecutionEngine/SectionMemoryManager.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
-#include "llvm/PassManager.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Transforms/Scalar.h"
 #include <cctype>
@@ -26,21 +28,27 @@ enum Token {
   tok_eof = -1,
 
   // commands
-  tok_def = -2, tok_extern = -3,
+  tok_def = -2,
+  tok_extern = -3,
 
   // primary
-  tok_identifier = -4, tok_number = -5,
-  
+  tok_identifier = -4,
+  tok_number = -5,
+
   // control
-  tok_if = -6, tok_then = -7, tok_else = -8,
-  tok_for = -9, tok_in = -10,
-  
+  tok_if = -6,
+  tok_then = -7,
+  tok_else = -8,
+  tok_for = -9,
+  tok_in = -10,
+
   // operators
-  tok_binary = -11, tok_unary = -12
+  tok_binary = -11,
+  tok_unary = -12
 };
 
-static std::string IdentifierStr;  // Filled in if tok_identifier
-static double NumVal;              // Filled in if tok_number
+static std::string IdentifierStr; // Filled in if tok_identifier
+static double NumVal;             // Filled in if tok_number
 
 /// gettok - Return the next token from standard input.
 static int gettok() {
@@ -55,19 +63,28 @@ static int gettok() {
     while (isalnum((LastChar = getchar())))
       IdentifierStr += LastChar;
 
-    if (IdentifierStr == "def") return tok_def;
-    if (IdentifierStr == "extern") return tok_extern;
-    if (IdentifierStr == "if") return tok_if;
-    if (IdentifierStr == "then") return tok_then;
-    if (IdentifierStr == "else") return tok_else;
-    if (IdentifierStr == "for") return tok_for;
-    if (IdentifierStr == "in") return tok_in;
-    if (IdentifierStr == "binary") return tok_binary;
-    if (IdentifierStr == "unary") return tok_unary;
+    if (IdentifierStr == "def")
+      return tok_def;
+    if (IdentifierStr == "extern")
+      return tok_extern;
+    if (IdentifierStr == "if")
+      return tok_if;
+    if (IdentifierStr == "then")
+      return tok_then;
+    if (IdentifierStr == "else")
+      return tok_else;
+    if (IdentifierStr == "for")
+      return tok_for;
+    if (IdentifierStr == "in")
+      return tok_in;
+    if (IdentifierStr == "binary")
+      return tok_binary;
+    if (IdentifierStr == "unary")
+      return tok_unary;
     return tok_identifier;
   }
 
-  if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
+  if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
     std::string NumStr;
     do {
       NumStr += LastChar;
@@ -80,13 +97,14 @@ static int gettok() {
 
   if (LastChar == '#') {
     // Comment until end of line.
-    do LastChar = getchar();
+    do
+      LastChar = getchar();
     while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
-    
+
     if (LastChar != EOF)
       return gettok();
   }
-  
+
   // Check for end of file.  Don't eat the EOF.
   if (LastChar == EOF)
     return tok_eof;
@@ -111,6 +129,7 @@ public:
 /// NumberExprAST - Expression class for numeric literals like "1.0".
 class NumberExprAST : public ExprAST {
   double Val;
+
 public:
   NumberExprAST(double val) : Val(val) {}
   virtual Value *Codegen();
@@ -119,6 +138,7 @@ public:
 /// VariableExprAST - Expression class for referencing a variable, like "a".
 class VariableExprAST : public ExprAST {
   std::string Name;
+
 public:
   VariableExprAST(const std::string &name) : Name(name) {}
   virtual Value *Codegen();
@@ -128,9 +148,10 @@ public:
 class UnaryExprAST : public ExprAST {
   char Opcode;
   ExprAST *Operand;
+
 public:
-  UnaryExprAST(char opcode, ExprAST *operand) 
-    : Opcode(opcode), Operand(operand) {}
+  UnaryExprAST(char opcode, ExprAST *operand)
+      : Opcode(opcode), Operand(operand) {}
   virtual Value *Codegen();
 };
 
@@ -138,28 +159,31 @@ public:
 class BinaryExprAST : public ExprAST {
   char Op;
   ExprAST *LHS, *RHS;
+
 public:
-  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) 
-    : Op(op), LHS(lhs), RHS(rhs) {}
+  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
+      : Op(op), LHS(lhs), RHS(rhs) {}
   virtual Value *Codegen();
 };
 
 /// CallExprAST - Expression class for function calls.
 class CallExprAST : public ExprAST {
   std::string Callee;
-  std::vector<ExprAST*> Args;
+  std::vector<ExprAST *> Args;
+
 public:
-  CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
-    : Callee(callee), Args(args) {}
+  CallExprAST(const std::string &callee, std::vector<ExprAST *> &args)
+      : Callee(callee), Args(args) {}
   virtual Value *Codegen();
 };
 
 /// IfExprAST - Expression class for if/then/else.
 class IfExprAST : public ExprAST {
   ExprAST *Cond, *Then, *Else;
+
 public:
   IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
-  : Cond(cond), Then(then), Else(_else) {}
+      : Cond(cond), Then(then), Else(_else) {}
   virtual Value *Codegen();
 };
 
@@ -167,10 +191,11 @@ public:
 class ForExprAST : public ExprAST {
   std::string VarName;
   ExprAST *Start, *End, *Step, *Body;
+
 public:
   ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
              ExprAST *step, ExprAST *body)
-    : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
+      : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
   virtual Value *Codegen();
 };
 
@@ -181,22 +206,22 @@ class PrototypeAST {
   std::string Name;
   std::vector<std::string> Args;
   bool isOperator;
-  unsigned Precedence;  // Precedence if a binary op.
+  unsigned Precedence; // Precedence if a binary op.
 public:
   PrototypeAST(const std::string &name, const std::vector<std::string> &args,
                bool isoperator = false, unsigned prec = 0)
-  : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
-  
+      : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
+
   bool isUnaryOp() const { return isOperator && Args.size() == 1; }
   bool isBinaryOp() const { return isOperator && Args.size() == 2; }
-  
+
   char getOperatorName() const {
     assert(isUnaryOp() || isBinaryOp());
-    return Name[Name.size()-1];
+    return Name[Name.size() - 1];
   }
-  
+
   unsigned getBinaryPrecedence() const { return Precedence; }
-  
+
   Function *Codegen();
 };
 
@@ -204,10 +229,10 @@ public:
 class FunctionAST {
   PrototypeAST *Proto;
   ExprAST *Body;
+
 public:
-  FunctionAST(PrototypeAST *proto, ExprAST *body)
-    : Proto(proto), Body(body) {}
-  
+  FunctionAST(PrototypeAST *proto, ExprAST *body) : Proto(proto), Body(body) {}
+
   Function *Codegen();
 };
 } // end anonymous namespace
@@ -220,9 +245,7 @@ public:
 /// token the parser is looking at.  getNextToken reads another token from the
 /// lexer and updates CurTok with its results.
 static int CurTok;
-static int getNextToken() {
-  return CurTok = gettok();
-}
+static int getNextToken() { return CurTok = gettok(); }
 
 /// BinopPrecedence - This holds the precedence for each binary operator that is
 /// defined.
@@ -232,17 +255,27 @@ static std::map<char, int> BinopPrecedence;
 static int GetTokPrecedence() {
   if (!isascii(CurTok))
     return -1;
-  
+
   // Make sure it's a declared binop.
   int TokPrec = BinopPrecedence[CurTok];
-  if (TokPrec <= 0) return -1;
+  if (TokPrec <= 0)
+    return -1;
   return TokPrec;
 }
 
 /// Error* - These are little helper functions for error handling.
-ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
-PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
-FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
+ExprAST *Error(const char *Str) {
+  fprintf(stderr, "Error: %s\n", Str);
+  return 0;
+}
+PrototypeAST *ErrorP(const char *Str) {
+  Error(Str);
+  return 0;
+}
+FunctionAST *ErrorF(const char *Str) {
+  Error(Str);
+  return 0;
+}
 
 static ExprAST *ParseExpression();
 
@@ -251,22 +284,24 @@ static ExprAST *ParseExpression();
 ///   ::= identifier '(' expression* ')'
 static ExprAST *ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
-  
-  getNextToken();  // eat identifier.
-  
+
+  getNextToken(); // eat identifier.
+
   if (CurTok != '(') // Simple variable ref.
     return new VariableExprAST(IdName);
-  
+
   // Call.
-  getNextToken();  // eat (
-  std::vector<ExprAST*> Args;
+  getNextToken(); // eat (
+  std::vector<ExprAST *> Args;
   if (CurTok != ')') {
     while (1) {
       ExprAST *Arg = ParseExpression();
-      if (!Arg) return 0;
+      if (!Arg)
+        return 0;
       Args.push_back(Arg);
 
-      if (CurTok == ')') break;
+      if (CurTok == ')')
+        break;
 
       if (CurTok != ',')
         return Error("Expected ')' or ',' in argument list");
@@ -276,7 +311,7 @@ static ExprAST *ParseIdentifierExpr() {
 
   // Eat the ')'.
   getNextToken();
-  
+
   return new CallExprAST(IdName, Args);
 }
 
@@ -289,80 +324,87 @@ static ExprAST *ParseNumberExpr() {
 
 /// parenexpr ::= '(' expression ')'
 static ExprAST *ParseParenExpr() {
-  getNextToken();  // eat (.
+  getNextToken(); // eat (.
   ExprAST *V = ParseExpression();
-  if (!V) return 0;
-  
+  if (!V)
+    return 0;
+
   if (CurTok != ')')
     return Error("expected ')'");
-  getNextToken();  // eat ).
+  getNextToken(); // eat ).
   return V;
 }
 
 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
 static ExprAST *ParseIfExpr() {
-  getNextToken();  // eat the if.
-  
+  getNextToken(); // eat the if.
+
   // condition.
   ExprAST *Cond = ParseExpression();
-  if (!Cond) return 0;
-  
+  if (!Cond)
+    return 0;
+
   if (CurTok != tok_then)
     return Error("expected then");
-  getNextToken();  // eat the then
-  
+  getNextToken(); // eat the then
+
   ExprAST *Then = ParseExpression();
-  if (Then == 0) return 0;
-  
+  if (Then == 0)
+    return 0;
+
   if (CurTok != tok_else)
     return Error("expected else");
-  
+
   getNextToken();
-  
+
   ExprAST *Else = ParseExpression();
-  if (!Else) return 0;
-  
+  if (!Else)
+    return 0;
+
   return new IfExprAST(Cond, Then, Else);
 }
 
 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
 static ExprAST *ParseForExpr() {
-  getNextToken();  // eat the for.
+  getNextToken(); // eat the for.
 
   if (CurTok != tok_identifier)
     return Error("expected identifier after for");
-  
+
   std::string IdName = IdentifierStr;
-  getNextToken();  // eat identifier.
-  
+  getNextToken(); // eat identifier.
+
   if (CurTok != '=')
     return Error("expected '=' after for");
-  getNextToken();  // eat '='.
-  
-  
+  getNextToken(); // eat '='.
+
   ExprAST *Start = ParseExpression();
-  if (Start == 0) return 0;
+  if (Start == 0)
+    return 0;
   if (CurTok != ',')
     return Error("expected ',' after for start value");
   getNextToken();
-  
+
   ExprAST *End = ParseExpression();
-  if (End == 0) return 0;
-  
+  if (End == 0)
+    return 0;
+
   // The step value is optional.
   ExprAST *Step = 0;
   if (CurTok == ',') {
     getNextToken();
     Step = ParseExpression();
-    if (Step == 0) return 0;
+    if (Step == 0)
+      return 0;
   }
-  
+
   if (CurTok != tok_in)
     return Error("expected 'in' after for");
-  getNextToken();  // eat 'in'.
-  
+  getNextToken(); // eat 'in'.
+
   ExprAST *Body = ParseExpression();
-  if (Body == 0) return 0;
+  if (Body == 0)
+    return 0;
 
   return new ForExprAST(IdName, Start, End, Step, Body);
 }
@@ -375,12 +417,18 @@ static ExprAST *ParseForExpr() {
 ///   ::= forexpr
 static ExprAST *ParsePrimary() {
   switch (CurTok) {
-  default: return Error("unknown token when expecting an expression");
-  case tok_identifier: return ParseIdentifierExpr();
-  case tok_number:     return ParseNumberExpr();
-  case '(':            return ParseParenExpr();
-  case tok_if:         return ParseIfExpr();
-  case tok_for:        return ParseForExpr();
+  default:
+    return Error("unknown token when expecting an expression");
+  case tok_identifier:
+    return ParseIdentifierExpr();
+  case tok_number:
+    return ParseNumberExpr();
+  case '(':
+    return ParseParenExpr();
+  case tok_if:
+    return ParseIfExpr();
+  case tok_for:
+    return ParseForExpr();
   }
 }
 
@@ -391,7 +439,7 @@ static ExprAST *ParseUnary() {
   // If the current token is not an operator, it must be a primary expr.
   if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
     return ParsePrimary();
-  
+
   // If this is a unary operator, read it.
   int Opc = CurTok;
   getNextToken();
@@ -406,28 +454,30 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
   // If this is a binop, find its precedence.
   while (1) {
     int TokPrec = GetTokPrecedence();
-    
+
     // If this is a binop that binds at least as tightly as the current binop,
     // consume it, otherwise we are done.
     if (TokPrec < ExprPrec)
       return LHS;
-    
+
     // Okay, we know this is a binop.
     int BinOp = CurTok;
-    getNextToken();  // eat binop
-    
+    getNextToken(); // eat binop
+
     // Parse the unary expression after the binary operator.
     ExprAST *RHS = ParseUnary();
-    if (!RHS) return 0;
-    
+    if (!RHS)
+      return 0;
+
     // If BinOp binds less tightly with RHS than the operator after RHS, let
     // the pending operator take RHS as its LHS.
     int NextPrec = GetTokPrecedence();
     if (TokPrec < NextPrec) {
-      RHS = ParseBinOpRHS(TokPrec+1, RHS);
-      if (RHS == 0) return 0;
+      RHS = ParseBinOpRHS(TokPrec + 1, RHS);
+      if (RHS == 0)
+        return 0;
     }
-    
+
     // Merge LHS/RHS.
     LHS = new BinaryExprAST(BinOp, LHS, RHS);
   }
@@ -438,8 +488,9 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
 ///
 static ExprAST *ParseExpression() {
   ExprAST *LHS = ParseUnary();
-  if (!LHS) return 0;
-  
+  if (!LHS)
+    return 0;
+
   return ParseBinOpRHS(0, LHS);
 }
 
@@ -449,10 +500,10 @@ static ExprAST *ParseExpression() {
 ///   ::= unary LETTER (id)
 static PrototypeAST *ParsePrototype() {
   std::string FnName;
-  
+
   unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
   unsigned BinaryPrecedence = 30;
-  
+
   switch (CurTok) {
   default:
     return ErrorP("Expected function name in prototype");
@@ -478,7 +529,7 @@ static PrototypeAST *ParsePrototype() {
     FnName += (char)CurTok;
     Kind = 2;
     getNextToken();
-    
+
     // Read the precedence if present.
     if (CurTok == tok_number) {
       if (NumVal < 1 || NumVal > 100)
@@ -488,31 +539,32 @@ static PrototypeAST *ParsePrototype() {
     }
     break;
   }
-  
+
   if (CurTok != '(')
     return ErrorP("Expected '(' in prototype");
-  
+
   std::vector<std::string> ArgNames;
   while (getNextToken() == tok_identifier)
     ArgNames.push_back(IdentifierStr);
   if (CurTok != ')')
     return ErrorP("Expected ')' in prototype");
-  
+
   // success.
-  getNextToken();  // eat ')'.
-  
+  getNextToken(); // eat ')'.
+
   // Verify right number of names for operator.
   if (Kind && ArgNames.size() != Kind)
     return ErrorP("Invalid number of operands for operator");
-  
+
   return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
 }
 
 /// definition ::= 'def' prototype expression
 static FunctionAST *ParseDefinition() {
-  getNextToken();  // eat def.
+  getNextToken(); // eat def.
   PrototypeAST *Proto = ParsePrototype();
-  if (Proto == 0) return 0;
+  if (Proto == 0)
+    return 0;
 
   if (ExprAST *E = ParseExpression())
     return new FunctionAST(Proto, E);
@@ -531,7 +583,7 @@ static FunctionAST *ParseTopLevelExpr() {
 
 /// external ::= 'extern' prototype
 static PrototypeAST *ParseExtern() {
-  getNextToken();  // eat extern.
+  getNextToken(); // eat extern.
   return ParsePrototype();
 }
 
@@ -541,10 +593,13 @@ static PrototypeAST *ParseExtern() {
 
 static Module *TheModule;
 static IRBuilder<> Builder(getGlobalContext());
-static std::map<std::string, Value*> NamedValues;
-static FunctionPassManager *TheFPM;
+static std::map<std::string, Value *> NamedValues;
+static legacy::FunctionPassManager *TheFPM;
 
-Value *ErrorV(const char *Str) { Error(Str); return 0; }
+Value *ErrorV(const char *Str) {
+  Error(Str);
+  return 0;
+}
 
 Value *NumberExprAST::Codegen() {
   return ConstantFP::get(getGlobalContext(), APFloat(Val));
@@ -558,37 +613,43 @@ Value *VariableExprAST::Codegen() {
 
 Value *UnaryExprAST::Codegen() {
   Value *OperandV = Operand->Codegen();
-  if (OperandV == 0) return 0;
-  
-  Function *F = TheModule->getFunction(std::string("unary")+Opcode);
+  if (OperandV == 0)
+    return 0;
+
+  Function *F = TheModule->getFunction(std::string("unary") + Opcode);
   if (F == 0)
     return ErrorV("Unknown unary operator");
-  
+
   return Builder.CreateCall(F, OperandV, "unop");
 }
 
 Value *BinaryExprAST::Codegen() {
   Value *L = LHS->Codegen();
   Value *R = RHS->Codegen();
-  if (L == 0 || R == 0) return 0;
-  
+  if (L == 0 || R == 0)
+    return 0;
+
   switch (Op) {
-  case '+': return Builder.CreateFAdd(L, R, "addtmp");
-  case '-': return Builder.CreateFSub(L, R, "subtmp");
-  case '*': return Builder.CreateFMul(L, R, "multmp");
+  case '+':
+    return Builder.CreateFAdd(L, R, "addtmp");
+  case '-':
+    return Builder.CreateFSub(L, R, "subtmp");
+  case '*':
+    return Builder.CreateFMul(L, R, "multmp");
   case '<':
     L = Builder.CreateFCmpULT(L, R, "cmptmp");
     // Convert bool 0/1 to double 0.0 or 1.0
     return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
                                 "booltmp");
-  default: break;
+  default:
+    break;
   }
-  
+
   // If it wasn't a builtin binary operator, it must be a user defined one. Emit
   // a call to it.
-  Function *F = TheModule->getFunction(std::string("binary")+Op);
+  Function *F = TheModule->getFunction(std::string("binary") + Op);
   assert(F && "binary operator not found!");
-  
+
   Value *Ops[] = { L, R };
   return Builder.CreateCall(F, Ops, "binop");
 }
@@ -598,66 +659,70 @@ Value *CallExprAST::Codegen() {
   Function *CalleeF = TheModule->getFunction(Callee);
   if (CalleeF == 0)
     return ErrorV("Unknown function referenced");
-  
+
   // If argument mismatch error.
   if (CalleeF->arg_size() != Args.size())
     return ErrorV("Incorrect # arguments passed");
 
-  std::vector<Value*> ArgsV;
+  std::vector<Value *> ArgsV;
   for (unsigned i = 0, e = Args.size(); i != e; ++i) {
     ArgsV.push_back(Args[i]->Codegen());
-    if (ArgsV.back() == 0) return 0;
+    if (ArgsV.back() == 0)
+      return 0;
   }
-  
+
   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 }
 
 Value *IfExprAST::Codegen() {
   Value *CondV = Cond->Codegen();
-  if (CondV == 0) return 0;
-  
+  if (CondV == 0)
+    return 0;
+
   // Convert condition to a bool by comparing equal to 0.0.
-  CondV = Builder.CreateFCmpONE(CondV, 
-                              ConstantFP::get(getGlobalContext(), APFloat(0.0)),
-                                "ifcond");
-  
+  CondV = Builder.CreateFCmpONE(
+      CondV, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "ifcond");
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
-  
+
   // Create blocks for the then and else cases.  Insert the 'then' block at the
   // end of the function.
-  BasicBlock *ThenBB = BasicBlock::Create(getGlobalContext(), "then", TheFunction);
+  BasicBlock *ThenBB =
+      BasicBlock::Create(getGlobalContext(), "then", TheFunction);
   BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
   BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
-  
+
   Builder.CreateCondBr(CondV, ThenBB, ElseBB);
-  
+
   // Emit then value.
   Builder.SetInsertPoint(ThenBB);
-  
+
   Value *ThenV = Then->Codegen();
-  if (ThenV == 0) return 0;
-  
+  if (ThenV == 0)
+    return 0;
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
   ThenBB = Builder.GetInsertBlock();
-  
+
   // Emit else block.
   TheFunction->getBasicBlockList().push_back(ElseBB);
   Builder.SetInsertPoint(ElseBB);
-  
+
   Value *ElseV = Else->Codegen();
-  if (ElseV == 0) return 0;
-  
+  if (ElseV == 0)
+    return 0;
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
   ElseBB = Builder.GetInsertBlock();
-  
+
   // Emit merge block.
   TheFunction->getBasicBlockList().push_back(MergeBB);
   Builder.SetInsertPoint(MergeBB);
-  PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
-                                  "iftmp");
-  
+  PHINode *PN =
+      Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, "iftmp");
+
   PN->addIncoming(ThenV, ThenBB);
   PN->addIncoming(ElseV, ElseBB);
   return PN;
@@ -668,7 +733,7 @@ Value *ForExprAST::Codegen() {
   //   ...
   //   start = startexpr
   //   goto loop
-  // loop: 
+  // loop:
   //   variable = phi [start, loopheader], [nextvariable, loopend]
   //   ...
   //   bodyexpr
@@ -679,140 +744,145 @@ Value *ForExprAST::Codegen() {
   //   endcond = endexpr
   //   br endcond, loop, endloop
   // outloop:
-  
+
   // Emit the start code first, without 'variable' in scope.
   Value *StartVal = Start->Codegen();
-  if (StartVal == 0) return 0;
-  
+  if (StartVal == 0)
+    return 0;
+
   // Make the new basic block for the loop header, inserting after current
   // block.
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
   BasicBlock *PreheaderBB = Builder.GetInsertBlock();
-  BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
-  
+  BasicBlock *LoopBB =
+      BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
+
   // Insert an explicit fall through from the current block to the LoopBB.
   Builder.CreateBr(LoopBB);
 
   // Start insertion in LoopBB.
   Builder.SetInsertPoint(LoopBB);
-  
+
   // Start the PHI node with an entry for Start.
-  PHINode *Variable = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, VarName.c_str());
+  PHINode *Variable = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()),
+                                        2, VarName.c_str());
   Variable->addIncoming(StartVal, PreheaderBB);
-  
+
   // Within the loop, the variable is defined equal to the PHI node.  If it
   // shadows an existing variable, we have to restore it, so save it now.
   Value *OldVal = NamedValues[VarName];
   NamedValues[VarName] = Variable;
-  
+
   // Emit the body of the loop.  This, like any other expr, can change the
   // current BB.  Note that we ignore the value computed by the body, but don't
   // allow an error.
   if (Body->Codegen() == 0)
     return 0;
-  
+
   // Emit the step value.
   Value *StepVal;
   if (Step) {
     StepVal = Step->Codegen();
-    if (StepVal == 0) return 0;
+    if (StepVal == 0)
+      return 0;
   } else {
     // If not specified, use 1.0.
     StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
   }
-  
+
   Value *NextVar = Builder.CreateFAdd(Variable, StepVal, "nextvar");
 
   // Compute the end condition.
   Value *EndCond = End->Codegen();
-  if (EndCond == 0) return EndCond;
-  
+  if (EndCond == 0)
+    return EndCond;
+
   // Convert condition to a bool by comparing equal to 0.0.
-  EndCond = Builder.CreateFCmpONE(EndCond, 
-                              ConstantFP::get(getGlobalContext(), APFloat(0.0)),
-                                  "loopcond");
-  
+  EndCond = Builder.CreateFCmpONE(
+      EndCond, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "loopcond");
+
   // Create the "after loop" block and insert it.
   BasicBlock *LoopEndBB = Builder.GetInsertBlock();
-  BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
-  
+  BasicBlock *AfterBB =
+      BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
+
   // Insert the conditional branch into the end of LoopEndBB.
   Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
-  
+
   // Any new code will be inserted in AfterBB.
   Builder.SetInsertPoint(AfterBB);
-  
+
   // Add a new entry to the PHI node for the backedge.
   Variable->addIncoming(NextVar, LoopEndBB);
-  
+
   // Restore the unshadowed variable.
   if (OldVal)
     NamedValues[VarName] = OldVal;
   else
     NamedValues.erase(VarName);
 
-  
   // for expr always returns 0.0.
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
 
 Function *PrototypeAST::Codegen() {
   // Make the function type:  double(double,double) etc.
-  std::vector<Type*> Doubles(Args.size(),
-                             Type::getDoubleTy(getGlobalContext()));
-  FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
-                                       Doubles, false);
-  
-  Function *F = Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
-  
+  std::vector<Type *> Doubles(Args.size(),
+                              Type::getDoubleTy(getGlobalContext()));
+  FunctionType *FT =
+      FunctionType::get(Type::getDoubleTy(getGlobalContext()), Doubles, false);
+
+  Function *F =
+      Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
+
   // If F conflicted, there was already something named 'Name'.  If it has a
   // body, don't allow redefinition or reextern.
   if (F->getName() != Name) {
     // Delete the one we just made and get the existing one.
     F->eraseFromParent();
     F = TheModule->getFunction(Name);
-    
+
     // If F already has a body, reject this.
     if (!F->empty()) {
       ErrorF("redefinition of function");
       return 0;
     }
-    
+
     // If F took a different number of args, reject.
     if (F->arg_size() != Args.size()) {
       ErrorF("redefinition of function with different # args");
       return 0;
     }
   }
-  
+
   // Set names for all arguments.
   unsigned Idx = 0;
   for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
        ++AI, ++Idx) {
     AI->setName(Args[Idx]);
-    
+
     // Add arguments to variable symbol table.
     NamedValues[Args[Idx]] = AI;
   }
-  
+
   return F;
 }
 
 Function *FunctionAST::Codegen() {
   NamedValues.clear();
-  
+
   Function *TheFunction = Proto->Codegen();
   if (TheFunction == 0)
     return 0;
-  
+
   // If this is an operator, install it.
   if (Proto->isBinaryOp())
     BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
-  
+
   // Create a new basic block to start insertion into.
   BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
   Builder.SetInsertPoint(BB);
-  
+
   if (Value *RetVal = Body->Codegen()) {
     // Finish off the function.
     Builder.CreateRet(RetVal);
@@ -822,10 +892,10 @@ Function *FunctionAST::Codegen() {
 
     // Optimize the function.
     TheFPM->run(*TheFunction);
-    
+
     return TheFunction;
   }
-  
+
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
 
@@ -868,9 +938,10 @@ static void HandleTopLevelExpression() {
   // Evaluate a top-level expression into an anonymous function.
   if (FunctionAST *F = ParseTopLevelExpr()) {
     if (Function *LF = F->Codegen()) {
+      TheExecutionEngine->finalizeObject();
       // JIT the function, returning a function pointer.
       void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
-      
+
       // Cast it to the right type (takes no arguments, returns a double) so we
       // can call it as a native function.
       double (*FP)() = (double (*)())(intptr_t)FPtr;
@@ -887,11 +958,20 @@ static void MainLoop() {
   while (1) {
     fprintf(stderr, "ready> ");
     switch (CurTok) {
-    case tok_eof:    return;
-    case ';':        getNextToken(); break;  // ignore top-level semicolons.
-    case tok_def:    HandleDefinition(); break;
-    case tok_extern: HandleExtern(); break;
-    default:         HandleTopLevelExpression(); break;
+    case tok_eof:
+      return;
+    case ';':
+      getNextToken();
+      break; // ignore top-level semicolons.
+    case tok_def:
+      HandleDefinition();
+      break;
+    case tok_extern:
+      HandleExtern();
+      break;
+    default:
+      HandleTopLevelExpression();
+      break;
     }
   }
 }
@@ -901,15 +981,13 @@ static void MainLoop() {
 //===----------------------------------------------------------------------===//
 
 /// putchard - putchar that takes a double and returns 0.
-extern "C" 
-double putchard(double X) {
+extern "C" double putchard(double X) {
   putchar((char)X);
   return 0;
 }
 
 /// printd - printf that takes a double prints it as "%f\n", returning 0.
-extern "C" 
-double printd(double X) {
+extern "C" double printd(double X) {
   printf("%f\n", X);
   return 0;
 }
@@ -920,6 +998,8 @@ double printd(double X) {
 
 int main() {
   InitializeNativeTarget();
+  InitializeNativeTargetAsmPrinter();
+  InitializeNativeTargetAsmParser();
   LLVMContext &Context = getGlobalContext();
 
   // Install standard binary operators.
@@ -927,7 +1007,7 @@ int main() {
   BinopPrecedence['<'] = 10;
   BinopPrecedence['+'] = 20;
   BinopPrecedence['-'] = 20;
-  BinopPrecedence['*'] = 40;  // highest.
+  BinopPrecedence['*'] = 40; // highest.
 
   // Prime the first token.
   fprintf(stderr, "ready> ");
@@ -940,13 +1020,16 @@ int main() {
   // Create the JIT.  This takes ownership of the module.
   std::string ErrStr;
   TheExecutionEngine =
-      EngineBuilder(std::move(Owner)).setErrorStr(&ErrStr).create();
+      EngineBuilder(std::move(Owner))
+          .setErrorStr(&ErrStr)
+          .setMCJITMemoryManager(llvm::make_unique<SectionMemoryManager>())
+          .create();
   if (!TheExecutionEngine) {
     fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
     exit(1);
   }
 
-  FunctionPassManager OurFPM(TheModule);
+  legacy::FunctionPassManager OurFPM(TheModule);
 
   // Set up the optimizer pipeline.  Start with registering info about how the
   // target lays out data structures.
diff --git a/examples/Kaleidoscope/Chapter7/CMakeLists.txt b/examples/Kaleidoscope/Chapter7/CMakeLists.txt
index bdc0e55..4bc1b2c 100644
--- a/examples/Kaleidoscope/Chapter7/CMakeLists.txt
+++ b/examples/Kaleidoscope/Chapter7/CMakeLists.txt
@@ -3,15 +3,15 @@ set(LLVM_LINK_COMPONENTS
   Core
   ExecutionEngine
   InstCombine
-  MC
+  MCJIT
   ScalarOpts
   Support
   TransformUtils
-  nativecodegen
+  native
   )
 
 set(LLVM_REQUIRES_RTTI 1)
 
-add_llvm_example(Kaleidoscope-Ch7
+add_kaleidoscope_chapter(Kaleidoscope-Ch7
   toy.cpp
   )
diff --git a/examples/Kaleidoscope/Chapter7/toy.cpp b/examples/Kaleidoscope/Chapter7/toy.cpp
index 56a6fa9..82f083a 100644
--- a/examples/Kaleidoscope/Chapter7/toy.cpp
+++ b/examples/Kaleidoscope/Chapter7/toy.cpp
@@ -1,12 +1,14 @@
 #include "llvm/Analysis/Passes.h"
 #include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/ExecutionEngine/MCJIT.h"
+#include "llvm/ExecutionEngine/SectionMemoryManager.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
-#include "llvm/PassManager.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Transforms/Scalar.h"
 #include <cctype>
@@ -26,24 +28,30 @@ enum Token {
   tok_eof = -1,
 
   // commands
-  tok_def = -2, tok_extern = -3,
+  tok_def = -2,
+  tok_extern = -3,
 
   // primary
-  tok_identifier = -4, tok_number = -5,
-  
+  tok_identifier = -4,
+  tok_number = -5,
+
   // control
-  tok_if = -6, tok_then = -7, tok_else = -8,
-  tok_for = -9, tok_in = -10,
-  
+  tok_if = -6,
+  tok_then = -7,
+  tok_else = -8,
+  tok_for = -9,
+  tok_in = -10,
+
   // operators
-  tok_binary = -11, tok_unary = -12,
-  
+  tok_binary = -11,
+  tok_unary = -12,
+
   // var definition
   tok_var = -13
 };
 
-static std::string IdentifierStr;  // Filled in if tok_identifier
-static double NumVal;              // Filled in if tok_number
+static std::string IdentifierStr; // Filled in if tok_identifier
+static double NumVal;             // Filled in if tok_number
 
 /// gettok - Return the next token from standard input.
 static int gettok() {
@@ -58,20 +66,30 @@ static int gettok() {
     while (isalnum((LastChar = getchar())))
       IdentifierStr += LastChar;
 
-    if (IdentifierStr == "def") return tok_def;
-    if (IdentifierStr == "extern") return tok_extern;
-    if (IdentifierStr == "if") return tok_if;
-    if (IdentifierStr == "then") return tok_then;
-    if (IdentifierStr == "else") return tok_else;
-    if (IdentifierStr == "for") return tok_for;
-    if (IdentifierStr == "in") return tok_in;
-    if (IdentifierStr == "binary") return tok_binary;
-    if (IdentifierStr == "unary") return tok_unary;
-    if (IdentifierStr == "var") return tok_var;
+    if (IdentifierStr == "def")
+      return tok_def;
+    if (IdentifierStr == "extern")
+      return tok_extern;
+    if (IdentifierStr == "if")
+      return tok_if;
+    if (IdentifierStr == "then")
+      return tok_then;
+    if (IdentifierStr == "else")
+      return tok_else;
+    if (IdentifierStr == "for")
+      return tok_for;
+    if (IdentifierStr == "in")
+      return tok_in;
+    if (IdentifierStr == "binary")
+      return tok_binary;
+    if (IdentifierStr == "unary")
+      return tok_unary;
+    if (IdentifierStr == "var")
+      return tok_var;
     return tok_identifier;
   }
 
-  if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
+  if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
     std::string NumStr;
     do {
       NumStr += LastChar;
@@ -84,13 +102,14 @@ static int gettok() {
 
   if (LastChar == '#') {
     // Comment until end of line.
-    do LastChar = getchar();
+    do
+      LastChar = getchar();
     while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
-    
+
     if (LastChar != EOF)
       return gettok();
   }
-  
+
   // Check for end of file.  Don't eat the EOF.
   if (LastChar == EOF)
     return tok_eof;
@@ -115,6 +134,7 @@ public:
 /// NumberExprAST - Expression class for numeric literals like "1.0".
 class NumberExprAST : public ExprAST {
   double Val;
+
 public:
   NumberExprAST(double val) : Val(val) {}
   virtual Value *Codegen();
@@ -123,6 +143,7 @@ public:
 /// VariableExprAST - Expression class for referencing a variable, like "a".
 class VariableExprAST : public ExprAST {
   std::string Name;
+
 public:
   VariableExprAST(const std::string &name) : Name(name) {}
   const std::string &getName() const { return Name; }
@@ -133,9 +154,10 @@ public:
 class UnaryExprAST : public ExprAST {
   char Opcode;
   ExprAST *Operand;
+
 public:
-  UnaryExprAST(char opcode, ExprAST *operand) 
-    : Opcode(opcode), Operand(operand) {}
+  UnaryExprAST(char opcode, ExprAST *operand)
+      : Opcode(opcode), Operand(operand) {}
   virtual Value *Codegen();
 };
 
@@ -143,28 +165,31 @@ public:
 class BinaryExprAST : public ExprAST {
   char Op;
   ExprAST *LHS, *RHS;
+
 public:
-  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) 
-    : Op(op), LHS(lhs), RHS(rhs) {}
+  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
+      : Op(op), LHS(lhs), RHS(rhs) {}
   virtual Value *Codegen();
 };
 
 /// CallExprAST - Expression class for function calls.
 class CallExprAST : public ExprAST {
   std::string Callee;
-  std::vector<ExprAST*> Args;
+  std::vector<ExprAST *> Args;
+
 public:
-  CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
-    : Callee(callee), Args(args) {}
+  CallExprAST(const std::string &callee, std::vector<ExprAST *> &args)
+      : Callee(callee), Args(args) {}
   virtual Value *Codegen();
 };
 
 /// IfExprAST - Expression class for if/then/else.
 class IfExprAST : public ExprAST {
   ExprAST *Cond, *Then, *Else;
+
 public:
   IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
-  : Cond(cond), Then(then), Else(_else) {}
+      : Cond(cond), Then(then), Else(_else) {}
   virtual Value *Codegen();
 };
 
@@ -172,22 +197,24 @@ public:
 class ForExprAST : public ExprAST {
   std::string VarName;
   ExprAST *Start, *End, *Step, *Body;
+
 public:
   ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
              ExprAST *step, ExprAST *body)
-    : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
+      : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
   virtual Value *Codegen();
 };
 
 /// VarExprAST - Expression class for var/in
 class VarExprAST : public ExprAST {
-  std::vector<std::pair<std::string, ExprAST*> > VarNames;
+  std::vector<std::pair<std::string, ExprAST *> > VarNames;
   ExprAST *Body;
+
 public:
-  VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
+  VarExprAST(const std::vector<std::pair<std::string, ExprAST *> > &varnames,
              ExprAST *body)
-  : VarNames(varnames), Body(body) {}
-  
+      : VarNames(varnames), Body(body) {}
+
   virtual Value *Codegen();
 };
 
@@ -197,24 +224,24 @@ class PrototypeAST {
   std::string Name;
   std::vector<std::string> Args;
   bool isOperator;
-  unsigned Precedence;  // Precedence if a binary op.
+  unsigned Precedence; // Precedence if a binary op.
 public:
   PrototypeAST(const std::string &name, const std::vector<std::string> &args,
                bool isoperator = false, unsigned prec = 0)
-  : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
-  
+      : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
+
   bool isUnaryOp() const { return isOperator && Args.size() == 1; }
   bool isBinaryOp() const { return isOperator && Args.size() == 2; }
-  
+
   char getOperatorName() const {
     assert(isUnaryOp() || isBinaryOp());
-    return Name[Name.size()-1];
+    return Name[Name.size() - 1];
   }
-  
+
   unsigned getBinaryPrecedence() const { return Precedence; }
-  
+
   Function *Codegen();
-  
+
   void CreateArgumentAllocas(Function *F);
 };
 
@@ -222,10 +249,10 @@ public:
 class FunctionAST {
   PrototypeAST *Proto;
   ExprAST *Body;
+
 public:
-  FunctionAST(PrototypeAST *proto, ExprAST *body)
-    : Proto(proto), Body(body) {}
-  
+  FunctionAST(PrototypeAST *proto, ExprAST *body) : Proto(proto), Body(body) {}
+
   Function *Codegen();
 };
 } // end anonymous namespace
@@ -238,9 +265,7 @@ public:
 /// token the parser is looking at.  getNextToken reads another token from the
 /// lexer and updates CurTok with its results.
 static int CurTok;
-static int getNextToken() {
-  return CurTok = gettok();
-}
+static int getNextToken() { return CurTok = gettok(); }
 
 /// BinopPrecedence - This holds the precedence for each binary operator that is
 /// defined.
@@ -250,17 +275,27 @@ static std::map<char, int> BinopPrecedence;
 static int GetTokPrecedence() {
   if (!isascii(CurTok))
     return -1;
-  
+
   // Make sure it's a declared binop.
   int TokPrec = BinopPrecedence[CurTok];
-  if (TokPrec <= 0) return -1;
+  if (TokPrec <= 0)
+    return -1;
   return TokPrec;
 }
 
 /// Error* - These are little helper functions for error handling.
-ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
-PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
-FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
+ExprAST *Error(const char *Str) {
+  fprintf(stderr, "Error: %s\n", Str);
+  return 0;
+}
+PrototypeAST *ErrorP(const char *Str) {
+  Error(Str);
+  return 0;
+}
+FunctionAST *ErrorF(const char *Str) {
+  Error(Str);
+  return 0;
+}
 
 static ExprAST *ParseExpression();
 
@@ -269,22 +304,24 @@ static ExprAST *ParseExpression();
 ///   ::= identifier '(' expression* ')'
 static ExprAST *ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
-  
-  getNextToken();  // eat identifier.
-  
+
+  getNextToken(); // eat identifier.
+
   if (CurTok != '(') // Simple variable ref.
     return new VariableExprAST(IdName);
-  
+
   // Call.
-  getNextToken();  // eat (
-  std::vector<ExprAST*> Args;
+  getNextToken(); // eat (
+  std::vector<ExprAST *> Args;
   if (CurTok != ')') {
     while (1) {
       ExprAST *Arg = ParseExpression();
-      if (!Arg) return 0;
+      if (!Arg)
+        return 0;
       Args.push_back(Arg);
 
-      if (CurTok == ')') break;
+      if (CurTok == ')')
+        break;
 
       if (CurTok != ',')
         return Error("Expected ')' or ',' in argument list");
@@ -294,7 +331,7 @@ static ExprAST *ParseIdentifierExpr() {
 
   // Eat the ')'.
   getNextToken();
-  
+
   return new CallExprAST(IdName, Args);
 }
 
@@ -307,126 +344,136 @@ static ExprAST *ParseNumberExpr() {
 
 /// parenexpr ::= '(' expression ')'
 static ExprAST *ParseParenExpr() {
-  getNextToken();  // eat (.
+  getNextToken(); // eat (.
   ExprAST *V = ParseExpression();
-  if (!V) return 0;
-  
+  if (!V)
+    return 0;
+
   if (CurTok != ')')
     return Error("expected ')'");
-  getNextToken();  // eat ).
+  getNextToken(); // eat ).
   return V;
 }
 
 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
 static ExprAST *ParseIfExpr() {
-  getNextToken();  // eat the if.
-  
+  getNextToken(); // eat the if.
+
   // condition.
   ExprAST *Cond = ParseExpression();
-  if (!Cond) return 0;
-  
+  if (!Cond)
+    return 0;
+
   if (CurTok != tok_then)
     return Error("expected then");
-  getNextToken();  // eat the then
-  
+  getNextToken(); // eat the then
+
   ExprAST *Then = ParseExpression();
-  if (Then == 0) return 0;
-  
+  if (Then == 0)
+    return 0;
+
   if (CurTok != tok_else)
     return Error("expected else");
-  
+
   getNextToken();
-  
+
   ExprAST *Else = ParseExpression();
-  if (!Else) return 0;
-  
+  if (!Else)
+    return 0;
+
   return new IfExprAST(Cond, Then, Else);
 }
 
 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
 static ExprAST *ParseForExpr() {
-  getNextToken();  // eat the for.
+  getNextToken(); // eat the for.
 
   if (CurTok != tok_identifier)
     return Error("expected identifier after for");
-  
+
   std::string IdName = IdentifierStr;
-  getNextToken();  // eat identifier.
-  
+  getNextToken(); // eat identifier.
+
   if (CurTok != '=')
     return Error("expected '=' after for");
-  getNextToken();  // eat '='.
-  
-  
+  getNextToken(); // eat '='.
+
   ExprAST *Start = ParseExpression();
-  if (Start == 0) return 0;
+  if (Start == 0)
+    return 0;
   if (CurTok != ',')
     return Error("expected ',' after for start value");
   getNextToken();
-  
+
   ExprAST *End = ParseExpression();
-  if (End == 0) return 0;
-  
+  if (End == 0)
+    return 0;
+
   // The step value is optional.
   ExprAST *Step = 0;
   if (CurTok == ',') {
     getNextToken();
     Step = ParseExpression();
-    if (Step == 0) return 0;
+    if (Step == 0)
+      return 0;
   }
-  
+
   if (CurTok != tok_in)
     return Error("expected 'in' after for");
-  getNextToken();  // eat 'in'.
-  
+  getNextToken(); // eat 'in'.
+
   ExprAST *Body = ParseExpression();
-  if (Body == 0) return 0;
+  if (Body == 0)
+    return 0;
 
   return new ForExprAST(IdName, Start, End, Step, Body);
 }
 
-/// varexpr ::= 'var' identifier ('=' expression)? 
+/// varexpr ::= 'var' identifier ('=' expression)?
 //                    (',' identifier ('=' expression)?)* 'in' expression
 static ExprAST *ParseVarExpr() {
-  getNextToken();  // eat the var.
+  getNextToken(); // eat the var.
 
-  std::vector<std::pair<std::string, ExprAST*> > VarNames;
+  std::vector<std::pair<std::string, ExprAST *> > VarNames;
 
   // At least one variable name is required.
   if (CurTok != tok_identifier)
     return Error("expected identifier after var");
-  
+
   while (1) {
     std::string Name = IdentifierStr;
-    getNextToken();  // eat identifier.
+    getNextToken(); // eat identifier.
 
     // Read the optional initializer.
     ExprAST *Init = 0;
     if (CurTok == '=') {
       getNextToken(); // eat the '='.
-      
+
       Init = ParseExpression();
-      if (Init == 0) return 0;
+      if (Init == 0)
+        return 0;
     }
-    
+
     VarNames.push_back(std::make_pair(Name, Init));
-    
+
     // End of var list, exit loop.
-    if (CurTok != ',') break;
+    if (CurTok != ',')
+      break;
     getNextToken(); // eat the ','.
-    
+
     if (CurTok != tok_identifier)
       return Error("expected identifier list after var");
   }
-  
+
   // At this point, we have to have 'in'.
   if (CurTok != tok_in)
     return Error("expected 'in' keyword after 'var'");
-  getNextToken();  // eat 'in'.
-  
+  getNextToken(); // eat 'in'.
+
   ExprAST *Body = ParseExpression();
-  if (Body == 0) return 0;
-  
+  if (Body == 0)
+    return 0;
+
   return new VarExprAST(VarNames, Body);
 }
 
@@ -439,13 +486,20 @@ static ExprAST *ParseVarExpr() {
 ///   ::= varexpr
 static ExprAST *ParsePrimary() {
   switch (CurTok) {
-  default: return Error("unknown token when expecting an expression");
-  case tok_identifier: return ParseIdentifierExpr();
-  case tok_number:     return ParseNumberExpr();
-  case '(':            return ParseParenExpr();
-  case tok_if:         return ParseIfExpr();
-  case tok_for:        return ParseForExpr();
-  case tok_var:        return ParseVarExpr();
+  default:
+    return Error("unknown token when expecting an expression");
+  case tok_identifier:
+    return ParseIdentifierExpr();
+  case tok_number:
+    return ParseNumberExpr();
+  case '(':
+    return ParseParenExpr();
+  case tok_if:
+    return ParseIfExpr();
+  case tok_for:
+    return ParseForExpr();
+  case tok_var:
+    return ParseVarExpr();
   }
 }
 
@@ -456,7 +510,7 @@ static ExprAST *ParseUnary() {
   // If the current token is not an operator, it must be a primary expr.
   if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
     return ParsePrimary();
-  
+
   // If this is a unary operator, read it.
   int Opc = CurTok;
   getNextToken();
@@ -471,28 +525,30 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
   // If this is a binop, find its precedence.
   while (1) {
     int TokPrec = GetTokPrecedence();
-    
+
     // If this is a binop that binds at least as tightly as the current binop,
     // consume it, otherwise we are done.
     if (TokPrec < ExprPrec)
       return LHS;
-    
+
     // Okay, we know this is a binop.
     int BinOp = CurTok;
-    getNextToken();  // eat binop
-    
+    getNextToken(); // eat binop
+
     // Parse the unary expression after the binary operator.
     ExprAST *RHS = ParseUnary();
-    if (!RHS) return 0;
-    
+    if (!RHS)
+      return 0;
+
     // If BinOp binds less tightly with RHS than the operator after RHS, let
     // the pending operator take RHS as its LHS.
     int NextPrec = GetTokPrecedence();
     if (TokPrec < NextPrec) {
-      RHS = ParseBinOpRHS(TokPrec+1, RHS);
-      if (RHS == 0) return 0;
+      RHS = ParseBinOpRHS(TokPrec + 1, RHS);
+      if (RHS == 0)
+        return 0;
     }
-    
+
     // Merge LHS/RHS.
     LHS = new BinaryExprAST(BinOp, LHS, RHS);
   }
@@ -503,8 +559,9 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
 ///
 static ExprAST *ParseExpression() {
   ExprAST *LHS = ParseUnary();
-  if (!LHS) return 0;
-  
+  if (!LHS)
+    return 0;
+
   return ParseBinOpRHS(0, LHS);
 }
 
@@ -514,10 +571,10 @@ static ExprAST *ParseExpression() {
 ///   ::= unary LETTER (id)
 static PrototypeAST *ParsePrototype() {
   std::string FnName;
-  
+
   unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
   unsigned BinaryPrecedence = 30;
-  
+
   switch (CurTok) {
   default:
     return ErrorP("Expected function name in prototype");
@@ -543,7 +600,7 @@ static PrototypeAST *ParsePrototype() {
     FnName += (char)CurTok;
     Kind = 2;
     getNextToken();
-    
+
     // Read the precedence if present.
     if (CurTok == tok_number) {
       if (NumVal < 1 || NumVal > 100)
@@ -553,31 +610,32 @@ static PrototypeAST *ParsePrototype() {
     }
     break;
   }
-  
+
   if (CurTok != '(')
     return ErrorP("Expected '(' in prototype");
-  
+
   std::vector<std::string> ArgNames;
   while (getNextToken() == tok_identifier)
     ArgNames.push_back(IdentifierStr);
   if (CurTok != ')')
     return ErrorP("Expected ')' in prototype");
-  
+
   // success.
-  getNextToken();  // eat ')'.
-  
+  getNextToken(); // eat ')'.
+
   // Verify right number of names for operator.
   if (Kind && ArgNames.size() != Kind)
     return ErrorP("Invalid number of operands for operator");
-  
+
   return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
 }
 
 /// definition ::= 'def' prototype expression
 static FunctionAST *ParseDefinition() {
-  getNextToken();  // eat def.
+  getNextToken(); // eat def.
   PrototypeAST *Proto = ParsePrototype();
-  if (Proto == 0) return 0;
+  if (Proto == 0)
+    return 0;
 
   if (ExprAST *E = ParseExpression())
     return new FunctionAST(Proto, E);
@@ -596,7 +654,7 @@ static FunctionAST *ParseTopLevelExpr() {
 
 /// external ::= 'extern' prototype
 static PrototypeAST *ParseExtern() {
-  getNextToken();  // eat extern.
+  getNextToken(); // eat extern.
   return ParsePrototype();
 }
 
@@ -606,17 +664,20 @@ static PrototypeAST *ParseExtern() {
 
 static Module *TheModule;
 static IRBuilder<> Builder(getGlobalContext());
-static std::map<std::string, AllocaInst*> NamedValues;
-static FunctionPassManager *TheFPM;
+static std::map<std::string, AllocaInst *> NamedValues;
+static legacy::FunctionPassManager *TheFPM;
 
-Value *ErrorV(const char *Str) { Error(Str); return 0; }
+Value *ErrorV(const char *Str) {
+  Error(Str);
+  return 0;
+}
 
 /// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
 /// the function.  This is used for mutable variables etc.
 static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
                                           const std::string &VarName) {
   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
-                 TheFunction->getEntryBlock().begin());
+                   TheFunction->getEntryBlock().begin());
   return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
                            VarName.c_str());
 }
@@ -628,7 +689,8 @@ Value *NumberExprAST::Codegen() {
 Value *VariableExprAST::Codegen() {
   // Look this variable up in the function.
   Value *V = NamedValues[Name];
-  if (V == 0) return ErrorV("Unknown variable name");
+  if (V == 0)
+    return ErrorV("Unknown variable name");
 
   // Load the value.
   return Builder.CreateLoad(V, Name.c_str());
@@ -636,12 +698,13 @@ Value *VariableExprAST::Codegen() {
 
 Value *UnaryExprAST::Codegen() {
   Value *OperandV = Operand->Codegen();
-  if (OperandV == 0) return 0;
-  
-  Function *F = TheModule->getFunction(std::string("unary")+Opcode);
+  if (OperandV == 0)
+    return 0;
+
+  Function *F = TheModule->getFunction(std::string("unary") + Opcode);
   if (F == 0)
     return ErrorV("Unknown unary operator");
-  
+
   return Builder.CreateCall(F, OperandV, "unop");
 }
 
@@ -649,42 +712,49 @@ Value *BinaryExprAST::Codegen() {
   // Special case '=' because we don't want to emit the LHS as an expression.
   if (Op == '=') {
     // Assignment requires the LHS to be an identifier.
-    VariableExprAST *LHSE = dynamic_cast<VariableExprAST*>(LHS);
+    VariableExprAST *LHSE = dynamic_cast<VariableExprAST *>(LHS);
     if (!LHSE)
       return ErrorV("destination of '=' must be a variable");
     // Codegen the RHS.
     Value *Val = RHS->Codegen();
-    if (Val == 0) return 0;
+    if (Val == 0)
+      return 0;
 
     // Look up the name.
     Value *Variable = NamedValues[LHSE->getName()];
-    if (Variable == 0) return ErrorV("Unknown variable name");
+    if (Variable == 0)
+      return ErrorV("Unknown variable name");
 
     Builder.CreateStore(Val, Variable);
     return Val;
   }
-  
+
   Value *L = LHS->Codegen();
   Value *R = RHS->Codegen();
-  if (L == 0 || R == 0) return 0;
-  
+  if (L == 0 || R == 0)
+    return 0;
+
   switch (Op) {
-  case '+': return Builder.CreateFAdd(L, R, "addtmp");
-  case '-': return Builder.CreateFSub(L, R, "subtmp");
-  case '*': return Builder.CreateFMul(L, R, "multmp");    
+  case '+':
+    return Builder.CreateFAdd(L, R, "addtmp");
+  case '-':
+    return Builder.CreateFSub(L, R, "subtmp");
+  case '*':
+    return Builder.CreateFMul(L, R, "multmp");
   case '<':
     L = Builder.CreateFCmpULT(L, R, "cmptmp");
     // Convert bool 0/1 to double 0.0 or 1.0
     return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
                                 "booltmp");
-  default: break;
+  default:
+    break;
   }
-  
+
   // If it wasn't a builtin binary operator, it must be a user defined one. Emit
   // a call to it.
-  Function *F = TheModule->getFunction(std::string("binary")+Op);
+  Function *F = TheModule->getFunction(std::string("binary") + Op);
   assert(F && "binary operator not found!");
-  
+
   Value *Ops[] = { L, R };
   return Builder.CreateCall(F, Ops, "binop");
 }
@@ -694,66 +764,70 @@ Value *CallExprAST::Codegen() {
   Function *CalleeF = TheModule->getFunction(Callee);
   if (CalleeF == 0)
     return ErrorV("Unknown function referenced");
-  
+
   // If argument mismatch error.
   if (CalleeF->arg_size() != Args.size())
     return ErrorV("Incorrect # arguments passed");
 
-  std::vector<Value*> ArgsV;
+  std::vector<Value *> ArgsV;
   for (unsigned i = 0, e = Args.size(); i != e; ++i) {
     ArgsV.push_back(Args[i]->Codegen());
-    if (ArgsV.back() == 0) return 0;
+    if (ArgsV.back() == 0)
+      return 0;
   }
-  
+
   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 }
 
 Value *IfExprAST::Codegen() {
   Value *CondV = Cond->Codegen();
-  if (CondV == 0) return 0;
-  
+  if (CondV == 0)
+    return 0;
+
   // Convert condition to a bool by comparing equal to 0.0.
-  CondV = Builder.CreateFCmpONE(CondV, 
-                              ConstantFP::get(getGlobalContext(), APFloat(0.0)),
-                                "ifcond");
-  
+  CondV = Builder.CreateFCmpONE(
+      CondV, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "ifcond");
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
-  
+
   // Create blocks for the then and else cases.  Insert the 'then' block at the
   // end of the function.
-  BasicBlock *ThenBB = BasicBlock::Create(getGlobalContext(), "then", TheFunction);
+  BasicBlock *ThenBB =
+      BasicBlock::Create(getGlobalContext(), "then", TheFunction);
   BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
   BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
-  
+
   Builder.CreateCondBr(CondV, ThenBB, ElseBB);
-  
+
   // Emit then value.
   Builder.SetInsertPoint(ThenBB);
-  
+
   Value *ThenV = Then->Codegen();
-  if (ThenV == 0) return 0;
-  
+  if (ThenV == 0)
+    return 0;
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
   ThenBB = Builder.GetInsertBlock();
-  
+
   // Emit else block.
   TheFunction->getBasicBlockList().push_back(ElseBB);
   Builder.SetInsertPoint(ElseBB);
-  
+
   Value *ElseV = Else->Codegen();
-  if (ElseV == 0) return 0;
-  
+  if (ElseV == 0)
+    return 0;
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
   ElseBB = Builder.GetInsertBlock();
-  
+
   // Emit merge block.
   TheFunction->getBasicBlockList().push_back(MergeBB);
   Builder.SetInsertPoint(MergeBB);
-  PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
-                                  "iftmp");
-  
+  PHINode *PN =
+      Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, "iftmp");
+
   PN->addIncoming(ThenV, ThenBB);
   PN->addIncoming(ElseV, ElseBB);
   return PN;
@@ -766,7 +840,7 @@ Value *ForExprAST::Codegen() {
   //   start = startexpr
   //   store start -> var
   //   goto loop
-  // loop: 
+  // loop:
   //   ...
   //   bodyexpr
   //   ...
@@ -779,95 +853,98 @@ Value *ForExprAST::Codegen() {
   //   store nextvar -> var
   //   br endcond, loop, endloop
   // outloop:
-  
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 
   // Create an alloca for the variable in the entry block.
   AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
-  
+
   // Emit the start code first, without 'variable' in scope.
   Value *StartVal = Start->Codegen();
-  if (StartVal == 0) return 0;
-  
+  if (StartVal == 0)
+    return 0;
+
   // Store the value into the alloca.
   Builder.CreateStore(StartVal, Alloca);
-  
+
   // Make the new basic block for the loop header, inserting after current
   // block.
-  BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
-  
+  BasicBlock *LoopBB =
+      BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
+
   // Insert an explicit fall through from the current block to the LoopBB.
   Builder.CreateBr(LoopBB);
 
   // Start insertion in LoopBB.
   Builder.SetInsertPoint(LoopBB);
-  
+
   // Within the loop, the variable is defined equal to the PHI node.  If it
   // shadows an existing variable, we have to restore it, so save it now.
   AllocaInst *OldVal = NamedValues[VarName];
   NamedValues[VarName] = Alloca;
-  
+
   // Emit the body of the loop.  This, like any other expr, can change the
   // current BB.  Note that we ignore the value computed by the body, but don't
   // allow an error.
   if (Body->Codegen() == 0)
     return 0;
-  
+
   // Emit the step value.
   Value *StepVal;
   if (Step) {
     StepVal = Step->Codegen();
-    if (StepVal == 0) return 0;
+    if (StepVal == 0)
+      return 0;
   } else {
     // If not specified, use 1.0.
     StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
   }
-  
+
   // Compute the end condition.
   Value *EndCond = End->Codegen();
-  if (EndCond == 0) return EndCond;
-  
+  if (EndCond == 0)
+    return EndCond;
+
   // Reload, increment, and restore the alloca.  This handles the case where
   // the body of the loop mutates the variable.
   Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
   Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
   Builder.CreateStore(NextVar, Alloca);
-  
+
   // Convert condition to a bool by comparing equal to 0.0.
-  EndCond = Builder.CreateFCmpONE(EndCond, 
-                              ConstantFP::get(getGlobalContext(), APFloat(0.0)),
-                                  "loopcond");
-  
+  EndCond = Builder.CreateFCmpONE(
+      EndCond, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "loopcond");
+
   // Create the "after loop" block and insert it.
-  BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
-  
+  BasicBlock *AfterBB =
+      BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
+
   // Insert the conditional branch into the end of LoopEndBB.
   Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
-  
+
   // Any new code will be inserted in AfterBB.
   Builder.SetInsertPoint(AfterBB);
-  
+
   // Restore the unshadowed variable.
   if (OldVal)
     NamedValues[VarName] = OldVal;
   else
     NamedValues.erase(VarName);
 
-  
   // for expr always returns 0.0.
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
 
 Value *VarExprAST::Codegen() {
   std::vector<AllocaInst *> OldBindings;
-  
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 
   // Register all variables and emit their initializer.
   for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
     const std::string &VarName = VarNames[i].first;
     ExprAST *Init = VarNames[i].second;
-    
+
     // Emit the initializer before adding the variable to scope, this prevents
     // the initializer from referencing the variable itself, and permits stuff
     // like this:
@@ -876,26 +953,28 @@ Value *VarExprAST::Codegen() {
     Value *InitVal;
     if (Init) {
       InitVal = Init->Codegen();
-      if (InitVal == 0) return 0;
+      if (InitVal == 0)
+        return 0;
     } else { // If not specified, use 0.0.
       InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
     }
-    
+
     AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
     Builder.CreateStore(InitVal, Alloca);
 
     // Remember the old variable binding so that we can restore the binding when
     // we unrecurse.
     OldBindings.push_back(NamedValues[VarName]);
-    
+
     // Remember this binding.
     NamedValues[VarName] = Alloca;
   }
-  
+
   // Codegen the body, now that all vars are in scope.
   Value *BodyVal = Body->Codegen();
-  if (BodyVal == 0) return 0;
-  
+  if (BodyVal == 0)
+    return 0;
+
   // Pop all our variables from scope.
   for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
     NamedValues[VarNames[i].first] = OldBindings[i];
@@ -906,39 +985,40 @@ Value *VarExprAST::Codegen() {
 
 Function *PrototypeAST::Codegen() {
   // Make the function type:  double(double,double) etc.
-  std::vector<Type*> Doubles(Args.size(), 
-                             Type::getDoubleTy(getGlobalContext()));
-  FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
-                                       Doubles, false);
-  
-  Function *F = Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
-  
+  std::vector<Type *> Doubles(Args.size(),
+                              Type::getDoubleTy(getGlobalContext()));
+  FunctionType *FT =
+      FunctionType::get(Type::getDoubleTy(getGlobalContext()), Doubles, false);
+
+  Function *F =
+      Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
+
   // If F conflicted, there was already something named 'Name'.  If it has a
   // body, don't allow redefinition or reextern.
   if (F->getName() != Name) {
     // Delete the one we just made and get the existing one.
     F->eraseFromParent();
     F = TheModule->getFunction(Name);
-    
+
     // If F already has a body, reject this.
     if (!F->empty()) {
       ErrorF("redefinition of function");
       return 0;
     }
-    
+
     // If F took a different number of args, reject.
     if (F->arg_size() != Args.size()) {
       ErrorF("redefinition of function with different # args");
       return 0;
     }
   }
-  
+
   // Set names for all arguments.
   unsigned Idx = 0;
   for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
        ++AI, ++Idx)
     AI->setName(Args[Idx]);
-    
+
   return F;
 }
 
@@ -960,19 +1040,19 @@ void PrototypeAST::CreateArgumentAllocas(Function *F) {
 
 Function *FunctionAST::Codegen() {
   NamedValues.clear();
-  
+
   Function *TheFunction = Proto->Codegen();
   if (TheFunction == 0)
     return 0;
-  
+
   // If this is an operator, install it.
   if (Proto->isBinaryOp())
     BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
-  
+
   // Create a new basic block to start insertion into.
   BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
   Builder.SetInsertPoint(BB);
-  
+
   // Add all arguments to the symbol table and create their allocas.
   Proto->CreateArgumentAllocas(TheFunction);
 
@@ -985,10 +1065,10 @@ Function *FunctionAST::Codegen() {
 
     // Optimize the function.
     TheFPM->run(*TheFunction);
-    
+
     return TheFunction;
   }
-  
+
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
 
@@ -1031,9 +1111,10 @@ static void HandleTopLevelExpression() {
   // Evaluate a top-level expression into an anonymous function.
   if (FunctionAST *F = ParseTopLevelExpr()) {
     if (Function *LF = F->Codegen()) {
+      TheExecutionEngine->finalizeObject();
       // JIT the function, returning a function pointer.
       void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
-      
+
       // Cast it to the right type (takes no arguments, returns a double) so we
       // can call it as a native function.
       double (*FP)() = (double (*)())(intptr_t)FPtr;
@@ -1050,11 +1131,20 @@ static void MainLoop() {
   while (1) {
     fprintf(stderr, "ready> ");
     switch (CurTok) {
-    case tok_eof:    return;
-    case ';':        getNextToken(); break;  // ignore top-level semicolons.
-    case tok_def:    HandleDefinition(); break;
-    case tok_extern: HandleExtern(); break;
-    default:         HandleTopLevelExpression(); break;
+    case tok_eof:
+      return;
+    case ';':
+      getNextToken();
+      break; // ignore top-level semicolons.
+    case tok_def:
+      HandleDefinition();
+      break;
+    case tok_extern:
+      HandleExtern();
+      break;
+    default:
+      HandleTopLevelExpression();
+      break;
     }
   }
 }
@@ -1064,15 +1154,13 @@ static void MainLoop() {
 //===----------------------------------------------------------------------===//
 
 /// putchard - putchar that takes a double and returns 0.
-extern "C" 
-double putchard(double X) {
+extern "C" double putchard(double X) {
   putchar((char)X);
   return 0;
 }
 
 /// printd - printf that takes a double prints it as "%f\n", returning 0.
-extern "C" 
-double printd(double X) {
+extern "C" double printd(double X) {
   printf("%f\n", X);
   return 0;
 }
@@ -1083,6 +1171,8 @@ double printd(double X) {
 
 int main() {
   InitializeNativeTarget();
+  InitializeNativeTargetAsmPrinter();
+  InitializeNativeTargetAsmParser();
   LLVMContext &Context = getGlobalContext();
 
   // Install standard binary operators.
@@ -1091,7 +1181,7 @@ int main() {
   BinopPrecedence['<'] = 10;
   BinopPrecedence['+'] = 20;
   BinopPrecedence['-'] = 20;
-  BinopPrecedence['*'] = 40;  // highest.
+  BinopPrecedence['*'] = 40; // highest.
 
   // Prime the first token.
   fprintf(stderr, "ready> ");
@@ -1104,13 +1194,16 @@ int main() {
   // Create the JIT.  This takes ownership of the module.
   std::string ErrStr;
   TheExecutionEngine =
-      EngineBuilder(std::move(Owner)).setErrorStr(&ErrStr).create();
+      EngineBuilder(std::move(Owner))
+          .setErrorStr(&ErrStr)
+          .setMCJITMemoryManager(llvm::make_unique<SectionMemoryManager>())
+          .create();
   if (!TheExecutionEngine) {
     fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
     exit(1);
   }
 
-  FunctionPassManager OurFPM(TheModule);
+  legacy::FunctionPassManager OurFPM(TheModule);
 
   // Set up the optimizer pipeline.  Start with registering info about how the
   // target lays out data structures.
diff --git a/examples/Kaleidoscope/Chapter8/CMakeLists.txt b/examples/Kaleidoscope/Chapter8/CMakeLists.txt
new file mode 100644
index 0000000..42882e9
--- /dev/null
+++ b/examples/Kaleidoscope/Chapter8/CMakeLists.txt
@@ -0,0 +1,13 @@
+set(LLVM_LINK_COMPONENTS
+  Core
+  ExecutionEngine
+  MCJIT
+  Support
+  native
+  )
+
+set(LLVM_REQUIRES_RTTI 1)
+
+add_kaleidoscope_chapter(Kaleidoscope-Ch8
+  toy.cpp
+  )
diff --git a/examples/Kaleidoscope/Chapter8/Makefile b/examples/Kaleidoscope/Chapter8/Makefile
new file mode 100644
index 0000000..8e4d422
--- /dev/null
+++ b/examples/Kaleidoscope/Chapter8/Makefile
@@ -0,0 +1,16 @@
+##===- examples/Kaleidoscope/Chapter7/Makefile -------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+LEVEL = ../../..
+TOOLNAME = Kaleidoscope-Ch8
+EXAMPLE_TOOL = 1
+REQUIRES_RTTI := 1
+
+LINK_COMPONENTS := core mcjit native
+
+include $(LEVEL)/Makefile.common
diff --git a/examples/Kaleidoscope/Chapter8/toy.cpp b/examples/Kaleidoscope/Chapter8/toy.cpp
new file mode 100644
index 0000000..30d4669
--- /dev/null
+++ b/examples/Kaleidoscope/Chapter8/toy.cpp
@@ -0,0 +1,1494 @@
+#include "llvm/ADT/Triple.h"
+#include "llvm/Analysis/Passes.h"
+#include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/ExecutionEngine/MCJIT.h"
+#include "llvm/ExecutionEngine/SectionMemoryManager.h"
+#include "llvm/IR/DIBuilder.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Transforms/Scalar.h"
+#include <cctype>
+#include <cstdio>
+#include <iostream>
+#include <map>
+#include <string>
+#include <vector>
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Lexer
+//===----------------------------------------------------------------------===//
+
+// The lexer returns tokens [0-255] if it is an unknown character, otherwise one
+// of these for known things.
+enum Token {
+  tok_eof = -1,
+
+  // commands
+  tok_def = -2,
+  tok_extern = -3,
+
+  // primary
+  tok_identifier = -4,
+  tok_number = -5,
+
+  // control
+  tok_if = -6,
+  tok_then = -7,
+  tok_else = -8,
+  tok_for = -9,
+  tok_in = -10,
+
+  // operators
+  tok_binary = -11,
+  tok_unary = -12,
+
+  // var definition
+  tok_var = -13
+};
+
+std::string getTokName(int Tok) {
+  switch (Tok) {
+  case tok_eof:
+    return "eof";
+  case tok_def:
+    return "def";
+  case tok_extern:
+    return "extern";
+  case tok_identifier:
+    return "identifier";
+  case tok_number:
+    return "number";
+  case tok_if:
+    return "if";
+  case tok_then:
+    return "then";
+  case tok_else:
+    return "else";
+  case tok_for:
+    return "for";
+  case tok_in:
+    return "in";
+  case tok_binary:
+    return "binary";
+  case tok_unary:
+    return "unary";
+  case tok_var:
+    return "var";
+  }
+  return std::string(1, (char)Tok);
+}
+
+namespace {
+class PrototypeAST;
+class ExprAST;
+}
+static IRBuilder<> Builder(getGlobalContext());
+struct DebugInfo {
+  DICompileUnit TheCU;
+  DIType DblTy;
+  std::vector<DIScope *> LexicalBlocks;
+  std::map<const PrototypeAST *, DIScope> FnScopeMap;
+
+  void emitLocation(ExprAST *AST);
+  DIType getDoubleTy();
+} KSDbgInfo;
+
+static std::string IdentifierStr; // Filled in if tok_identifier
+static double NumVal;             // Filled in if tok_number
+struct SourceLocation {
+  int Line;
+  int Col;
+};
+static SourceLocation CurLoc;
+static SourceLocation LexLoc = { 1, 0 };
+
+static int advance() {
+  int LastChar = getchar();
+
+  if (LastChar == '\n' || LastChar == '\r') {
+    LexLoc.Line++;
+    LexLoc.Col = 0;
+  } else
+    LexLoc.Col++;
+  return LastChar;
+}
+
+/// gettok - Return the next token from standard input.
+static int gettok() {
+  static int LastChar = ' ';
+
+  // Skip any whitespace.
+  while (isspace(LastChar))
+    LastChar = advance();
+
+  CurLoc = LexLoc;
+
+  if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
+    IdentifierStr = LastChar;
+    while (isalnum((LastChar = advance())))
+      IdentifierStr += LastChar;
+
+    if (IdentifierStr == "def")
+      return tok_def;
+    if (IdentifierStr == "extern")
+      return tok_extern;
+    if (IdentifierStr == "if")
+      return tok_if;
+    if (IdentifierStr == "then")
+      return tok_then;
+    if (IdentifierStr == "else")
+      return tok_else;
+    if (IdentifierStr == "for")
+      return tok_for;
+    if (IdentifierStr == "in")
+      return tok_in;
+    if (IdentifierStr == "binary")
+      return tok_binary;
+    if (IdentifierStr == "unary")
+      return tok_unary;
+    if (IdentifierStr == "var")
+      return tok_var;
+    return tok_identifier;
+  }
+
+  if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
+    std::string NumStr;
+    do {
+      NumStr += LastChar;
+      LastChar = advance();
+    } while (isdigit(LastChar) || LastChar == '.');
+
+    NumVal = strtod(NumStr.c_str(), 0);
+    return tok_number;
+  }
+
+  if (LastChar == '#') {
+    // Comment until end of line.
+    do
+      LastChar = advance();
+    while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
+
+    if (LastChar != EOF)
+      return gettok();
+  }
+
+  // Check for end of file.  Don't eat the EOF.
+  if (LastChar == EOF)
+    return tok_eof;
+
+  // Otherwise, just return the character as its ascii value.
+  int ThisChar = LastChar;
+  LastChar = advance();
+  return ThisChar;
+}
+
+//===----------------------------------------------------------------------===//
+// Abstract Syntax Tree (aka Parse Tree)
+//===----------------------------------------------------------------------===//
+namespace {
+
+std::ostream &indent(std::ostream &O, int size) {
+  return O << std::string(size, ' ');
+}
+
+/// ExprAST - Base class for all expression nodes.
+class ExprAST {
+  SourceLocation Loc;
+
+public:
+  int getLine() const { return Loc.Line; }
+  int getCol() const { return Loc.Col; }
+  ExprAST(SourceLocation Loc = CurLoc) : Loc(Loc) {}
+  virtual std::ostream &dump(std::ostream &out, int ind) {
+    return out << ':' << getLine() << ':' << getCol() << '\n';
+  }
+  virtual ~ExprAST() {}
+  virtual Value *Codegen() = 0;
+};
+
+/// NumberExprAST - Expression class for numeric literals like "1.0".
+class NumberExprAST : public ExprAST {
+  double Val;
+
+public:
+  NumberExprAST(double val) : Val(val) {}
+  virtual std::ostream &dump(std::ostream &out, int ind) {
+    return ExprAST::dump(out << Val, ind);
+  }
+  virtual Value *Codegen();
+};
+
+/// VariableExprAST - Expression class for referencing a variable, like "a".
+class VariableExprAST : public ExprAST {
+  std::string Name;
+
+public:
+  VariableExprAST(SourceLocation Loc, const std::string &name)
+      : ExprAST(Loc), Name(name) {}
+  const std::string &getName() const { return Name; }
+  virtual std::ostream &dump(std::ostream &out, int ind) {
+    return ExprAST::dump(out << Name, ind);
+  }
+  virtual Value *Codegen();
+};
+
+/// UnaryExprAST - Expression class for a unary operator.
+class UnaryExprAST : public ExprAST {
+  char Opcode;
+  ExprAST *Operand;
+
+public:
+  UnaryExprAST(char opcode, ExprAST *operand)
+      : Opcode(opcode), Operand(operand) {}
+  virtual std::ostream &dump(std::ostream &out, int ind) {
+    ExprAST::dump(out << "unary" << Opcode, ind);
+    Operand->dump(out, ind + 1);
+    return out;
+  }
+  virtual Value *Codegen();
+};
+
+/// BinaryExprAST - Expression class for a binary operator.
+class BinaryExprAST : public ExprAST {
+  char Op;
+  ExprAST *LHS, *RHS;
+
+public:
+  BinaryExprAST(SourceLocation Loc, char op, ExprAST *lhs, ExprAST *rhs)
+      : ExprAST(Loc), Op(op), LHS(lhs), RHS(rhs) {}
+  virtual std::ostream &dump(std::ostream &out, int ind) {
+    ExprAST::dump(out << "binary" << Op, ind);
+    LHS->dump(indent(out, ind) << "LHS:", ind + 1);
+    RHS->dump(indent(out, ind) << "RHS:", ind + 1);
+    return out;
+  }
+  virtual Value *Codegen();
+};
+
+/// CallExprAST - Expression class for function calls.
+class CallExprAST : public ExprAST {
+  std::string Callee;
+  std::vector<ExprAST *> Args;
+
+public:
+  CallExprAST(SourceLocation Loc, const std::string &callee,
+              std::vector<ExprAST *> &args)
+      : ExprAST(Loc), Callee(callee), Args(args) {}
+  virtual std::ostream &dump(std::ostream &out, int ind) {
+    ExprAST::dump(out << "call " << Callee, ind);
+    for (ExprAST *Arg : Args)
+      Arg->dump(indent(out, ind + 1), ind + 1);
+    return out;
+  }
+  virtual Value *Codegen();
+};
+
+/// IfExprAST - Expression class for if/then/else.
+class IfExprAST : public ExprAST {
+  ExprAST *Cond, *Then, *Else;
+
+public:
+  IfExprAST(SourceLocation Loc, ExprAST *cond, ExprAST *then, ExprAST *_else)
+      : ExprAST(Loc), Cond(cond), Then(then), Else(_else) {}
+  virtual std::ostream &dump(std::ostream &out, int ind) {
+    ExprAST::dump(out << "if", ind);
+    Cond->dump(indent(out, ind) << "Cond:", ind + 1);
+    Then->dump(indent(out, ind) << "Then:", ind + 1);
+    Else->dump(indent(out, ind) << "Else:", ind + 1);
+    return out;
+  }
+  virtual Value *Codegen();
+};
+
+/// ForExprAST - Expression class for for/in.
+class ForExprAST : public ExprAST {
+  std::string VarName;
+  ExprAST *Start, *End, *Step, *Body;
+
+public:
+  ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
+             ExprAST *step, ExprAST *body)
+      : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
+  virtual std::ostream &dump(std::ostream &out, int ind) {
+    ExprAST::dump(out << "for", ind);
+    Start->dump(indent(out, ind) << "Cond:", ind + 1);
+    End->dump(indent(out, ind) << "End:", ind + 1);
+    Step->dump(indent(out, ind) << "Step:", ind + 1);
+    Body->dump(indent(out, ind) << "Body:", ind + 1);
+    return out;
+  }
+  virtual Value *Codegen();
+};
+
+/// VarExprAST - Expression class for var/in
+class VarExprAST : public ExprAST {
+  std::vector<std::pair<std::string, ExprAST *> > VarNames;
+  ExprAST *Body;
+
+public:
+  VarExprAST(const std::vector<std::pair<std::string, ExprAST *> > &varnames,
+             ExprAST *body)
+      : VarNames(varnames), Body(body) {}
+
+  virtual std::ostream &dump(std::ostream &out, int ind) {
+    ExprAST::dump(out << "var", ind);
+    for (const auto &NamedVar : VarNames)
+      NamedVar.second->dump(indent(out, ind) << NamedVar.first << ':', ind + 1);
+    Body->dump(indent(out, ind) << "Body:", ind + 1);
+    return out;
+  }
+  virtual Value *Codegen();
+};
+
+/// PrototypeAST - This class represents the "prototype" for a function,
+/// which captures its argument names as well as if it is an operator.
+class PrototypeAST {
+  std::string Name;
+  std::vector<std::string> Args;
+  bool isOperator;
+  unsigned Precedence; // Precedence if a binary op.
+  int Line;
+
+public:
+  PrototypeAST(SourceLocation Loc, const std::string &name,
+               const std::vector<std::string> &args, bool isoperator = false,
+               unsigned prec = 0)
+      : Name(name), Args(args), isOperator(isoperator), Precedence(prec),
+        Line(Loc.Line) {}
+
+  bool isUnaryOp() const { return isOperator && Args.size() == 1; }
+  bool isBinaryOp() const { return isOperator && Args.size() == 2; }
+
+  char getOperatorName() const {
+    assert(isUnaryOp() || isBinaryOp());
+    return Name[Name.size() - 1];
+  }
+
+  unsigned getBinaryPrecedence() const { return Precedence; }
+
+  Function *Codegen();
+
+  void CreateArgumentAllocas(Function *F);
+  const std::vector<std::string> &getArgs() const { return Args; }
+};
+
+/// FunctionAST - This class represents a function definition itself.
+class FunctionAST {
+  PrototypeAST *Proto;
+  ExprAST *Body;
+
+public:
+  FunctionAST(PrototypeAST *proto, ExprAST *body) : Proto(proto), Body(body) {}
+
+  std::ostream &dump(std::ostream &out, int ind) {
+    indent(out, ind) << "FunctionAST\n";
+    ++ind;
+    indent(out, ind) << "Body:";
+    return Body ? Body->dump(out, ind) : out << "null\n";
+  }
+
+  Function *Codegen();
+};
+} // end anonymous namespace
+
+//===----------------------------------------------------------------------===//
+// Parser
+//===----------------------------------------------------------------------===//
+
+/// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
+/// token the parser is looking at.  getNextToken reads another token from the
+/// lexer and updates CurTok with its results.
+static int CurTok;
+static int getNextToken() { return CurTok = gettok(); }
+
+/// BinopPrecedence - This holds the precedence for each binary operator that is
+/// defined.
+static std::map<char, int> BinopPrecedence;
+
+/// GetTokPrecedence - Get the precedence of the pending binary operator token.
+static int GetTokPrecedence() {
+  if (!isascii(CurTok))
+    return -1;
+
+  // Make sure it's a declared binop.
+  int TokPrec = BinopPrecedence[CurTok];
+  if (TokPrec <= 0)
+    return -1;
+  return TokPrec;
+}
+
+/// Error* - These are little helper functions for error handling.
+ExprAST *Error(const char *Str) {
+  fprintf(stderr, "Error: %s\n", Str);
+  return 0;
+}
+PrototypeAST *ErrorP(const char *Str) {
+  Error(Str);
+  return 0;
+}
+FunctionAST *ErrorF(const char *Str) {
+  Error(Str);
+  return 0;
+}
+
+static ExprAST *ParseExpression();
+
+/// identifierexpr
+///   ::= identifier
+///   ::= identifier '(' expression* ')'
+static ExprAST *ParseIdentifierExpr() {
+  std::string IdName = IdentifierStr;
+
+  SourceLocation LitLoc = CurLoc;
+
+  getNextToken(); // eat identifier.
+
+  if (CurTok != '(') // Simple variable ref.
+    return new VariableExprAST(LitLoc, IdName);
+
+  // Call.
+  getNextToken(); // eat (
+  std::vector<ExprAST *> Args;
+  if (CurTok != ')') {
+    while (1) {
+      ExprAST *Arg = ParseExpression();
+      if (!Arg)
+        return 0;
+      Args.push_back(Arg);
+
+      if (CurTok == ')')
+        break;
+
+      if (CurTok != ',')
+        return Error("Expected ')' or ',' in argument list");
+      getNextToken();
+    }
+  }
+
+  // Eat the ')'.
+  getNextToken();
+
+  return new CallExprAST(LitLoc, IdName, Args);
+}
+
+/// numberexpr ::= number
+static ExprAST *ParseNumberExpr() {
+  ExprAST *Result = new NumberExprAST(NumVal);
+  getNextToken(); // consume the number
+  return Result;
+}
+
+/// parenexpr ::= '(' expression ')'
+static ExprAST *ParseParenExpr() {
+  getNextToken(); // eat (.
+  ExprAST *V = ParseExpression();
+  if (!V)
+    return 0;
+
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken(); // eat ).
+  return V;
+}
+
+/// ifexpr ::= 'if' expression 'then' expression 'else' expression
+static ExprAST *ParseIfExpr() {
+  SourceLocation IfLoc = CurLoc;
+
+  getNextToken(); // eat the if.
+
+  // condition.
+  ExprAST *Cond = ParseExpression();
+  if (!Cond)
+    return 0;
+
+  if (CurTok != tok_then)
+    return Error("expected then");
+  getNextToken(); // eat the then
+
+  ExprAST *Then = ParseExpression();
+  if (Then == 0)
+    return 0;
+
+  if (CurTok != tok_else)
+    return Error("expected else");
+
+  getNextToken();
+
+  ExprAST *Else = ParseExpression();
+  if (!Else)
+    return 0;
+
+  return new IfExprAST(IfLoc, Cond, Then, Else);
+}
+
+/// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
+static ExprAST *ParseForExpr() {
+  getNextToken(); // eat the for.
+
+  if (CurTok != tok_identifier)
+    return Error("expected identifier after for");
+
+  std::string IdName = IdentifierStr;
+  getNextToken(); // eat identifier.
+
+  if (CurTok != '=')
+    return Error("expected '=' after for");
+  getNextToken(); // eat '='.
+
+  ExprAST *Start = ParseExpression();
+  if (Start == 0)
+    return 0;
+  if (CurTok != ',')
+    return Error("expected ',' after for start value");
+  getNextToken();
+
+  ExprAST *End = ParseExpression();
+  if (End == 0)
+    return 0;
+
+  // The step value is optional.
+  ExprAST *Step = 0;
+  if (CurTok == ',') {
+    getNextToken();
+    Step = ParseExpression();
+    if (Step == 0)
+      return 0;
+  }
+
+  if (CurTok != tok_in)
+    return Error("expected 'in' after for");
+  getNextToken(); // eat 'in'.
+
+  ExprAST *Body = ParseExpression();
+  if (Body == 0)
+    return 0;
+
+  return new ForExprAST(IdName, Start, End, Step, Body);
+}
+
+/// varexpr ::= 'var' identifier ('=' expression)?
+//                    (',' identifier ('=' expression)?)* 'in' expression
+static ExprAST *ParseVarExpr() {
+  getNextToken(); // eat the var.
+
+  std::vector<std::pair<std::string, ExprAST *> > VarNames;
+
+  // At least one variable name is required.
+  if (CurTok != tok_identifier)
+    return Error("expected identifier after var");
+
+  while (1) {
+    std::string Name = IdentifierStr;
+    getNextToken(); // eat identifier.
+
+    // Read the optional initializer.
+    ExprAST *Init = 0;
+    if (CurTok == '=') {
+      getNextToken(); // eat the '='.
+
+      Init = ParseExpression();
+      if (Init == 0)
+        return 0;
+    }
+
+    VarNames.push_back(std::make_pair(Name, Init));
+
+    // End of var list, exit loop.
+    if (CurTok != ',')
+      break;
+    getNextToken(); // eat the ','.
+
+    if (CurTok != tok_identifier)
+      return Error("expected identifier list after var");
+  }
+
+  // At this point, we have to have 'in'.
+  if (CurTok != tok_in)
+    return Error("expected 'in' keyword after 'var'");
+  getNextToken(); // eat 'in'.
+
+  ExprAST *Body = ParseExpression();
+  if (Body == 0)
+    return 0;
+
+  return new VarExprAST(VarNames, Body);
+}
+
+/// primary
+///   ::= identifierexpr
+///   ::= numberexpr
+///   ::= parenexpr
+///   ::= ifexpr
+///   ::= forexpr
+///   ::= varexpr
+static ExprAST *ParsePrimary() {
+  switch (CurTok) {
+  default:
+    return Error("unknown token when expecting an expression");
+  case tok_identifier:
+    return ParseIdentifierExpr();
+  case tok_number:
+    return ParseNumberExpr();
+  case '(':
+    return ParseParenExpr();
+  case tok_if:
+    return ParseIfExpr();
+  case tok_for:
+    return ParseForExpr();
+  case tok_var:
+    return ParseVarExpr();
+  }
+}
+
+/// unary
+///   ::= primary
+///   ::= '!' unary
+static ExprAST *ParseUnary() {
+  // If the current token is not an operator, it must be a primary expr.
+  if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
+    return ParsePrimary();
+
+  // If this is a unary operator, read it.
+  int Opc = CurTok;
+  getNextToken();
+  if (ExprAST *Operand = ParseUnary())
+    return new UnaryExprAST(Opc, Operand);
+  return 0;
+}
+
+/// binoprhs
+///   ::= ('+' unary)*
+static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+  // If this is a binop, find its precedence.
+  while (1) {
+    int TokPrec = GetTokPrecedence();
+
+    // If this is a binop that binds at least as tightly as the current binop,
+    // consume it, otherwise we are done.
+    if (TokPrec < ExprPrec)
+      return LHS;
+
+    // Okay, we know this is a binop.
+    int BinOp = CurTok;
+    SourceLocation BinLoc = CurLoc;
+    getNextToken(); // eat binop
+
+    // Parse the unary expression after the binary operator.
+    ExprAST *RHS = ParseUnary();
+    if (!RHS)
+      return 0;
+
+    // If BinOp binds less tightly with RHS than the operator after RHS, let
+    // the pending operator take RHS as its LHS.
+    int NextPrec = GetTokPrecedence();
+    if (TokPrec < NextPrec) {
+      RHS = ParseBinOpRHS(TokPrec + 1, RHS);
+      if (RHS == 0)
+        return 0;
+    }
+
+    // Merge LHS/RHS.
+    LHS = new BinaryExprAST(BinLoc, BinOp, LHS, RHS);
+  }
+}
+
+/// expression
+///   ::= unary binoprhs
+///
+static ExprAST *ParseExpression() {
+  ExprAST *LHS = ParseUnary();
+  if (!LHS)
+    return 0;
+
+  return ParseBinOpRHS(0, LHS);
+}
+
+/// prototype
+///   ::= id '(' id* ')'
+///   ::= binary LETTER number? (id, id)
+///   ::= unary LETTER (id)
+static PrototypeAST *ParsePrototype() {
+  std::string FnName;
+
+  SourceLocation FnLoc = CurLoc;
+
+  unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
+  unsigned BinaryPrecedence = 30;
+
+  switch (CurTok) {
+  default:
+    return ErrorP("Expected function name in prototype");
+  case tok_identifier:
+    FnName = IdentifierStr;
+    Kind = 0;
+    getNextToken();
+    break;
+  case tok_unary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorP("Expected unary operator");
+    FnName = "unary";
+    FnName += (char)CurTok;
+    Kind = 1;
+    getNextToken();
+    break;
+  case tok_binary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorP("Expected binary operator");
+    FnName = "binary";
+    FnName += (char)CurTok;
+    Kind = 2;
+    getNextToken();
+
+    // Read the precedence if present.
+    if (CurTok == tok_number) {
+      if (NumVal < 1 || NumVal > 100)
+        return ErrorP("Invalid precedecnce: must be 1..100");
+      BinaryPrecedence = (unsigned)NumVal;
+      getNextToken();
+    }
+    break;
+  }
+
+  if (CurTok != '(')
+    return ErrorP("Expected '(' in prototype");
+
+  std::vector<std::string> ArgNames;
+  while (getNextToken() == tok_identifier)
+    ArgNames.push_back(IdentifierStr);
+  if (CurTok != ')')
+    return ErrorP("Expected ')' in prototype");
+
+  // success.
+  getNextToken(); // eat ')'.
+
+  // Verify right number of names for operator.
+  if (Kind && ArgNames.size() != Kind)
+    return ErrorP("Invalid number of operands for operator");
+
+  return new PrototypeAST(FnLoc, FnName, ArgNames, Kind != 0, BinaryPrecedence);
+}
+
+/// definition ::= 'def' prototype expression
+static FunctionAST *ParseDefinition() {
+  getNextToken(); // eat def.
+  PrototypeAST *Proto = ParsePrototype();
+  if (Proto == 0)
+    return 0;
+
+  if (ExprAST *E = ParseExpression())
+    return new FunctionAST(Proto, E);
+  return 0;
+}
+
+/// toplevelexpr ::= expression
+static FunctionAST *ParseTopLevelExpr() {
+  SourceLocation FnLoc = CurLoc;
+  if (ExprAST *E = ParseExpression()) {
+    // Make an anonymous proto.
+    PrototypeAST *Proto =
+        new PrototypeAST(FnLoc, "main", std::vector<std::string>());
+    return new FunctionAST(Proto, E);
+  }
+  return 0;
+}
+
+/// external ::= 'extern' prototype
+static PrototypeAST *ParseExtern() {
+  getNextToken(); // eat extern.
+  return ParsePrototype();
+}
+
+//===----------------------------------------------------------------------===//
+// Debug Info Support
+//===----------------------------------------------------------------------===//
+
+static DIBuilder *DBuilder;
+
+DIType DebugInfo::getDoubleTy() {
+  if (DblTy.isValid())
+    return DblTy;
+
+  DblTy = DBuilder->createBasicType("double", 64, 64, dwarf::DW_ATE_float);
+  return DblTy;
+}
+
+void DebugInfo::emitLocation(ExprAST *AST) {
+  if (!AST)
+    return Builder.SetCurrentDebugLocation(DebugLoc());
+  DIScope *Scope;
+  if (LexicalBlocks.empty())
+    Scope = &TheCU;
+  else
+    Scope = LexicalBlocks.back();
+  Builder.SetCurrentDebugLocation(
+      DebugLoc::get(AST->getLine(), AST->getCol(), DIScope(*Scope)));
+}
+
+static DICompositeType CreateFunctionType(unsigned NumArgs, DIFile Unit) {
+  SmallVector<Metadata *, 8> EltTys;
+  DIType DblTy = KSDbgInfo.getDoubleTy();
+
+  // Add the result type.
+  EltTys.push_back(DblTy);
+
+  for (unsigned i = 0, e = NumArgs; i != e; ++i)
+    EltTys.push_back(DblTy);
+
+  DITypeArray EltTypeArray = DBuilder->getOrCreateTypeArray(EltTys);
+  return DBuilder->createSubroutineType(Unit, EltTypeArray);
+}
+
+//===----------------------------------------------------------------------===//
+// Code Generation
+//===----------------------------------------------------------------------===//
+
+static Module *TheModule;
+static std::map<std::string, AllocaInst *> NamedValues;
+static legacy::FunctionPassManager *TheFPM;
+
+Value *ErrorV(const char *Str) {
+  Error(Str);
+  return 0;
+}
+
+/// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
+/// the function.  This is used for mutable variables etc.
+static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
+                                          const std::string &VarName) {
+  IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
+                   TheFunction->getEntryBlock().begin());
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+                           VarName.c_str());
+}
+
+Value *NumberExprAST::Codegen() {
+  KSDbgInfo.emitLocation(this);
+  return ConstantFP::get(getGlobalContext(), APFloat(Val));
+}
+
+Value *VariableExprAST::Codegen() {
+  // Look this variable up in the function.
+  Value *V = NamedValues[Name];
+  if (V == 0)
+    return ErrorV("Unknown variable name");
+
+  KSDbgInfo.emitLocation(this);
+  // Load the value.
+  return Builder.CreateLoad(V, Name.c_str());
+}
+
+Value *UnaryExprAST::Codegen() {
+  Value *OperandV = Operand->Codegen();
+  if (OperandV == 0)
+    return 0;
+
+  Function *F = TheModule->getFunction(std::string("unary") + Opcode);
+  if (F == 0)
+    return ErrorV("Unknown unary operator");
+
+  KSDbgInfo.emitLocation(this);
+  return Builder.CreateCall(F, OperandV, "unop");
+}
+
+Value *BinaryExprAST::Codegen() {
+  KSDbgInfo.emitLocation(this);
+
+  // Special case '=' because we don't want to emit the LHS as an expression.
+  if (Op == '=') {
+    // Assignment requires the LHS to be an identifier.
+    VariableExprAST *LHSE = dynamic_cast<VariableExprAST *>(LHS);
+    if (!LHSE)
+      return ErrorV("destination of '=' must be a variable");
+    // Codegen the RHS.
+    Value *Val = RHS->Codegen();
+    if (Val == 0)
+      return 0;
+
+    // Look up the name.
+    Value *Variable = NamedValues[LHSE->getName()];
+    if (Variable == 0)
+      return ErrorV("Unknown variable name");
+
+    Builder.CreateStore(Val, Variable);
+    return Val;
+  }
+
+  Value *L = LHS->Codegen();
+  Value *R = RHS->Codegen();
+  if (L == 0 || R == 0)
+    return 0;
+
+  switch (Op) {
+  case '+':
+    return Builder.CreateFAdd(L, R, "addtmp");
+  case '-':
+    return Builder.CreateFSub(L, R, "subtmp");
+  case '*':
+    return Builder.CreateFMul(L, R, "multmp");
+  case '<':
+    L = Builder.CreateFCmpULT(L, R, "cmptmp");
+    // Convert bool 0/1 to double 0.0 or 1.0
+    return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
+                                "booltmp");
+  default:
+    break;
+  }
+
+  // If it wasn't a builtin binary operator, it must be a user defined one. Emit
+  // a call to it.
+  Function *F = TheModule->getFunction(std::string("binary") + Op);
+  assert(F && "binary operator not found!");
+
+  Value *Ops[] = { L, R };
+  return Builder.CreateCall(F, Ops, "binop");
+}
+
+Value *CallExprAST::Codegen() {
+  KSDbgInfo.emitLocation(this);
+
+  // Look up the name in the global module table.
+  Function *CalleeF = TheModule->getFunction(Callee);
+  if (CalleeF == 0)
+    return ErrorV("Unknown function referenced");
+
+  // If argument mismatch error.
+  if (CalleeF->arg_size() != Args.size())
+    return ErrorV("Incorrect # arguments passed");
+
+  std::vector<Value *> ArgsV;
+  for (unsigned i = 0, e = Args.size(); i != e; ++i) {
+    ArgsV.push_back(Args[i]->Codegen());
+    if (ArgsV.back() == 0)
+      return 0;
+  }
+
+  return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
+}
+
+Value *IfExprAST::Codegen() {
+  KSDbgInfo.emitLocation(this);
+
+  Value *CondV = Cond->Codegen();
+  if (CondV == 0)
+    return 0;
+
+  // Convert condition to a bool by comparing equal to 0.0.
+  CondV = Builder.CreateFCmpONE(
+      CondV, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "ifcond");
+
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+
+  // Create blocks for the then and else cases.  Insert the 'then' block at the
+  // end of the function.
+  BasicBlock *ThenBB =
+      BasicBlock::Create(getGlobalContext(), "then", TheFunction);
+  BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
+  BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
+
+  Builder.CreateCondBr(CondV, ThenBB, ElseBB);
+
+  // Emit then value.
+  Builder.SetInsertPoint(ThenBB);
+
+  Value *ThenV = Then->Codegen();
+  if (ThenV == 0)
+    return 0;
+
+  Builder.CreateBr(MergeBB);
+  // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
+  ThenBB = Builder.GetInsertBlock();
+
+  // Emit else block.
+  TheFunction->getBasicBlockList().push_back(ElseBB);
+  Builder.SetInsertPoint(ElseBB);
+
+  Value *ElseV = Else->Codegen();
+  if (ElseV == 0)
+    return 0;
+
+  Builder.CreateBr(MergeBB);
+  // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
+  ElseBB = Builder.GetInsertBlock();
+
+  // Emit merge block.
+  TheFunction->getBasicBlockList().push_back(MergeBB);
+  Builder.SetInsertPoint(MergeBB);
+  PHINode *PN =
+      Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, "iftmp");
+
+  PN->addIncoming(ThenV, ThenBB);
+  PN->addIncoming(ElseV, ElseBB);
+  return PN;
+}
+
+Value *ForExprAST::Codegen() {
+  // Output this as:
+  //   var = alloca double
+  //   ...
+  //   start = startexpr
+  //   store start -> var
+  //   goto loop
+  // loop:
+  //   ...
+  //   bodyexpr
+  //   ...
+  // loopend:
+  //   step = stepexpr
+  //   endcond = endexpr
+  //
+  //   curvar = load var
+  //   nextvar = curvar + step
+  //   store nextvar -> var
+  //   br endcond, loop, endloop
+  // outloop:
+
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+
+  // Create an alloca for the variable in the entry block.
+  AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+
+  KSDbgInfo.emitLocation(this);
+
+  // Emit the start code first, without 'variable' in scope.
+  Value *StartVal = Start->Codegen();
+  if (StartVal == 0)
+    return 0;
+
+  // Store the value into the alloca.
+  Builder.CreateStore(StartVal, Alloca);
+
+  // Make the new basic block for the loop header, inserting after current
+  // block.
+  BasicBlock *LoopBB =
+      BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
+
+  // Insert an explicit fall through from the current block to the LoopBB.
+  Builder.CreateBr(LoopBB);
+
+  // Start insertion in LoopBB.
+  Builder.SetInsertPoint(LoopBB);
+
+  // Within the loop, the variable is defined equal to the PHI node.  If it
+  // shadows an existing variable, we have to restore it, so save it now.
+  AllocaInst *OldVal = NamedValues[VarName];
+  NamedValues[VarName] = Alloca;
+
+  // Emit the body of the loop.  This, like any other expr, can change the
+  // current BB.  Note that we ignore the value computed by the body, but don't
+  // allow an error.
+  if (Body->Codegen() == 0)
+    return 0;
+
+  // Emit the step value.
+  Value *StepVal;
+  if (Step) {
+    StepVal = Step->Codegen();
+    if (StepVal == 0)
+      return 0;
+  } else {
+    // If not specified, use 1.0.
+    StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
+  }
+
+  // Compute the end condition.
+  Value *EndCond = End->Codegen();
+  if (EndCond == 0)
+    return EndCond;
+
+  // Reload, increment, and restore the alloca.  This handles the case where
+  // the body of the loop mutates the variable.
+  Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
+  Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
+  Builder.CreateStore(NextVar, Alloca);
+
+  // Convert condition to a bool by comparing equal to 0.0.
+  EndCond = Builder.CreateFCmpONE(
+      EndCond, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "loopcond");
+
+  // Create the "after loop" block and insert it.
+  BasicBlock *AfterBB =
+      BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
+
+  // Insert the conditional branch into the end of LoopEndBB.
+  Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
+
+  // Any new code will be inserted in AfterBB.
+  Builder.SetInsertPoint(AfterBB);
+
+  // Restore the unshadowed variable.
+  if (OldVal)
+    NamedValues[VarName] = OldVal;
+  else
+    NamedValues.erase(VarName);
+
+  // for expr always returns 0.0.
+  return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
+}
+
+Value *VarExprAST::Codegen() {
+  std::vector<AllocaInst *> OldBindings;
+
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+
+  // Register all variables and emit their initializer.
+  for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
+    const std::string &VarName = VarNames[i].first;
+    ExprAST *Init = VarNames[i].second;
+
+    // Emit the initializer before adding the variable to scope, this prevents
+    // the initializer from referencing the variable itself, and permits stuff
+    // like this:
+    //  var a = 1 in
+    //    var a = a in ...   # refers to outer 'a'.
+    Value *InitVal;
+    if (Init) {
+      InitVal = Init->Codegen();
+      if (InitVal == 0)
+        return 0;
+    } else { // If not specified, use 0.0.
+      InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
+    }
+
+    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+    Builder.CreateStore(InitVal, Alloca);
+
+    // Remember the old variable binding so that we can restore the binding when
+    // we unrecurse.
+    OldBindings.push_back(NamedValues[VarName]);
+
+    // Remember this binding.
+    NamedValues[VarName] = Alloca;
+  }
+
+  KSDbgInfo.emitLocation(this);
+
+  // Codegen the body, now that all vars are in scope.
+  Value *BodyVal = Body->Codegen();
+  if (BodyVal == 0)
+    return 0;
+
+  // Pop all our variables from scope.
+  for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
+    NamedValues[VarNames[i].first] = OldBindings[i];
+
+  // Return the body computation.
+  return BodyVal;
+}
+
+Function *PrototypeAST::Codegen() {
+  // Make the function type:  double(double,double) etc.
+  std::vector<Type *> Doubles(Args.size(),
+                              Type::getDoubleTy(getGlobalContext()));
+  FunctionType *FT =
+      FunctionType::get(Type::getDoubleTy(getGlobalContext()), Doubles, false);
+
+  Function *F =
+      Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
+
+  // If F conflicted, there was already something named 'Name'.  If it has a
+  // body, don't allow redefinition or reextern.
+  if (F->getName() != Name) {
+    // Delete the one we just made and get the existing one.
+    F->eraseFromParent();
+    F = TheModule->getFunction(Name);
+
+    // If F already has a body, reject this.
+    if (!F->empty()) {
+      ErrorF("redefinition of function");
+      return 0;
+    }
+
+    // If F took a different number of args, reject.
+    if (F->arg_size() != Args.size()) {
+      ErrorF("redefinition of function with different # args");
+      return 0;
+    }
+  }
+
+  // Set names for all arguments.
+  unsigned Idx = 0;
+  for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
+       ++AI, ++Idx)
+    AI->setName(Args[Idx]);
+
+  // Create a subprogram DIE for this function.
+  DIFile Unit = DBuilder->createFile(KSDbgInfo.TheCU.getFilename(),
+                                     KSDbgInfo.TheCU.getDirectory());
+  DIDescriptor FContext(Unit);
+  unsigned LineNo = Line;
+  unsigned ScopeLine = Line;
+  DISubprogram SP = DBuilder->createFunction(
+      FContext, Name, StringRef(), Unit, LineNo,
+      CreateFunctionType(Args.size(), Unit), false /* internal linkage */,
+      true /* definition */, ScopeLine, DIDescriptor::FlagPrototyped, false, F);
+
+  KSDbgInfo.FnScopeMap[this] = SP;
+  return F;
+}
+
+/// CreateArgumentAllocas - Create an alloca for each argument and register the
+/// argument in the symbol table so that references to it will succeed.
+void PrototypeAST::CreateArgumentAllocas(Function *F) {
+  Function::arg_iterator AI = F->arg_begin();
+  for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
+    // Create an alloca for this variable.
+    AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
+
+    // Create a debug descriptor for the variable.
+    DIScope *Scope = KSDbgInfo.LexicalBlocks.back();
+    DIFile Unit = DBuilder->createFile(KSDbgInfo.TheCU.getFilename(),
+                                       KSDbgInfo.TheCU.getDirectory());
+    DIVariable D = DBuilder->createLocalVariable(dwarf::DW_TAG_arg_variable,
+                                                 *Scope, Args[Idx], Unit, Line,
+                                                 KSDbgInfo.getDoubleTy(), Idx);
+
+    Instruction *Call = DBuilder->insertDeclare(
+        Alloca, D, DBuilder->createExpression(), Builder.GetInsertBlock());
+    Call->setDebugLoc(DebugLoc::get(Line, 0, *Scope));
+
+    // Store the initial value into the alloca.
+    Builder.CreateStore(AI, Alloca);
+
+    // Add arguments to variable symbol table.
+    NamedValues[Args[Idx]] = Alloca;
+  }
+}
+
+Function *FunctionAST::Codegen() {
+  NamedValues.clear();
+
+  Function *TheFunction = Proto->Codegen();
+  if (TheFunction == 0)
+    return 0;
+
+  // Push the current scope.
+  KSDbgInfo.LexicalBlocks.push_back(&KSDbgInfo.FnScopeMap[Proto]);
+
+  // Unset the location for the prologue emission (leading instructions with no
+  // location in a function are considered part of the prologue and the debugger
+  // will run past them when breaking on a function)
+  KSDbgInfo.emitLocation(nullptr);
+
+  // If this is an operator, install it.
+  if (Proto->isBinaryOp())
+    BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
+
+  // Create a new basic block to start insertion into.
+  BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
+  Builder.SetInsertPoint(BB);
+
+  // Add all arguments to the symbol table and create their allocas.
+  Proto->CreateArgumentAllocas(TheFunction);
+
+  KSDbgInfo.emitLocation(Body);
+
+  if (Value *RetVal = Body->Codegen()) {
+    // Finish off the function.
+    Builder.CreateRet(RetVal);
+
+    // Pop off the lexical block for the function.
+    KSDbgInfo.LexicalBlocks.pop_back();
+
+    // Validate the generated code, checking for consistency.
+    verifyFunction(*TheFunction);
+
+    // Optimize the function.
+    TheFPM->run(*TheFunction);
+
+    return TheFunction;
+  }
+
+  // Error reading body, remove function.
+  TheFunction->eraseFromParent();
+
+  if (Proto->isBinaryOp())
+    BinopPrecedence.erase(Proto->getOperatorName());
+
+  // Pop off the lexical block for the function since we added it
+  // unconditionally.
+  KSDbgInfo.LexicalBlocks.pop_back();
+
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Top-Level parsing and JIT Driver
+//===----------------------------------------------------------------------===//
+
+static ExecutionEngine *TheExecutionEngine;
+
+static void HandleDefinition() {
+  if (FunctionAST *F = ParseDefinition()) {
+    if (!F->Codegen()) {
+      fprintf(stderr, "Error reading function definition:");
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleExtern() {
+  if (PrototypeAST *P = ParseExtern()) {
+    if (!P->Codegen()) {
+      fprintf(stderr, "Error reading extern");
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleTopLevelExpression() {
+  // Evaluate a top-level expression into an anonymous function.
+  if (FunctionAST *F = ParseTopLevelExpr()) {
+    if (!F->Codegen()) {
+      fprintf(stderr, "Error generating code for top level expr");
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+/// top ::= definition | external | expression | ';'
+static void MainLoop() {
+  while (1) {
+    switch (CurTok) {
+    case tok_eof:
+      return;
+    case ';':
+      getNextToken();
+      break; // ignore top-level semicolons.
+    case tok_def:
+      HandleDefinition();
+      break;
+    case tok_extern:
+      HandleExtern();
+      break;
+    default:
+      HandleTopLevelExpression();
+      break;
+    }
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// "Library" functions that can be "extern'd" from user code.
+//===----------------------------------------------------------------------===//
+
+/// putchard - putchar that takes a double and returns 0.
+extern "C" double putchard(double X) {
+  putchar((char)X);
+  return 0;
+}
+
+/// printd - printf that takes a double prints it as "%f\n", returning 0.
+extern "C" double printd(double X) {
+  printf("%f\n", X);
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Main driver code.
+//===----------------------------------------------------------------------===//
+
+int main() {
+  InitializeNativeTarget();
+  InitializeNativeTargetAsmPrinter();
+  InitializeNativeTargetAsmParser();
+  LLVMContext &Context = getGlobalContext();
+
+  // Install standard binary operators.
+  // 1 is lowest precedence.
+  BinopPrecedence['='] = 2;
+  BinopPrecedence['<'] = 10;
+  BinopPrecedence['+'] = 20;
+  BinopPrecedence['-'] = 20;
+  BinopPrecedence['*'] = 40; // highest.
+
+  // Prime the first token.
+  getNextToken();
+
+  // Make the module, which holds all the code.
+  std::unique_ptr<Module> Owner = make_unique<Module>("my cool jit", Context);
+  TheModule = Owner.get();
+
+  // Add the current debug info version into the module.
+  TheModule->addModuleFlag(Module::Warning, "Debug Info Version",
+                           DEBUG_METADATA_VERSION);
+
+  // Darwin only supports dwarf2.
+  if (Triple(sys::getProcessTriple()).isOSDarwin())
+    TheModule->addModuleFlag(llvm::Module::Warning, "Dwarf Version", 2);
+
+  // Construct the DIBuilder, we do this here because we need the module.
+  DBuilder = new DIBuilder(*TheModule);
+
+  // Create the compile unit for the module.
+  // Currently down as "fib.ks" as a filename since we're redirecting stdin
+  // but we'd like actual source locations.
+  KSDbgInfo.TheCU = DBuilder->createCompileUnit(
+      dwarf::DW_LANG_C, "fib.ks", ".", "Kaleidoscope Compiler", 0, "", 0);
+
+  // Create the JIT.  This takes ownership of the module.
+  std::string ErrStr;
+  TheExecutionEngine =
+      EngineBuilder(std::move(Owner))
+          .setErrorStr(&ErrStr)
+          .setMCJITMemoryManager(llvm::make_unique<SectionMemoryManager>())
+          .create();
+  if (!TheExecutionEngine) {
+    fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
+    exit(1);
+  }
+
+  legacy::FunctionPassManager OurFPM(TheModule);
+
+  // Set up the optimizer pipeline.  Start with registering info about how the
+  // target lays out data structures.
+  TheModule->setDataLayout(TheExecutionEngine->getDataLayout());
+  OurFPM.add(new DataLayoutPass());
+#if 0
+  // Provide basic AliasAnalysis support for GVN.
+  OurFPM.add(createBasicAliasAnalysisPass());
+  // Promote allocas to registers.
+  OurFPM.add(createPromoteMemoryToRegisterPass());
+  // Do simple "peephole" optimizations and bit-twiddling optzns.
+  OurFPM.add(createInstructionCombiningPass());
+  // Reassociate expressions.
+  OurFPM.add(createReassociatePass());
+  // Eliminate Common SubExpressions.
+  OurFPM.add(createGVNPass());
+  // Simplify the control flow graph (deleting unreachable blocks, etc).
+  OurFPM.add(createCFGSimplificationPass());
+  #endif
+  OurFPM.doInitialization();
+
+  // Set the global so the code gen can use this.
+  TheFPM = &OurFPM;
+
+  // Run the main "interpreter loop" now.
+  MainLoop();
+
+  TheFPM = 0;
+
+  // Finalize the debug info.
+  DBuilder->finalize();
+
+  // Print out all of the generated code.
+  TheModule->dump();
+
+  return 0;
+}
diff --git a/examples/Kaleidoscope/MCJIT/cached/toy-jit.cpp b/examples/Kaleidoscope/MCJIT/cached/toy-jit.cpp
index 00f5b83..7f5ed13 100644
--- a/examples/Kaleidoscope/MCJIT/cached/toy-jit.cpp
+++ b/examples/Kaleidoscope/MCJIT/cached/toy-jit.cpp
@@ -6,10 +6,10 @@
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/IRReader/IRReader.h"
-#include "llvm/PassManager.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/TargetSelect.h"
diff --git a/examples/Kaleidoscope/MCJIT/cached/toy.cpp b/examples/Kaleidoscope/MCJIT/cached/toy.cpp
index af51b4a..f598ca4 100644
--- a/examples/Kaleidoscope/MCJIT/cached/toy.cpp
+++ b/examples/Kaleidoscope/MCJIT/cached/toy.cpp
@@ -9,10 +9,10 @@
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/IRReader/IRReader.h"
-#include "llvm/PassManager.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
@@ -36,8 +36,8 @@ InputIR("input-IR",
         cl::desc("Specify the name of an IR file to load for function definitions"),
         cl::value_desc("input IR file name"));
 
-cl::opt<bool> 
-UseObjectCache("use-object-cache", 
+cl::opt<bool>
+UseObjectCache("use-object-cache",
                cl::desc("Enable use of the MCJIT object caching"),
                cl::init(false));
 
@@ -55,14 +55,14 @@ enum Token {
 
   // primary
   tok_identifier = -4, tok_number = -5,
-  
+
   // control
   tok_if = -6, tok_then = -7, tok_else = -8,
   tok_for = -9, tok_in = -10,
-  
+
   // operators
   tok_binary = -11, tok_unary = -12,
-  
+
   // var definition
   tok_var = -13
 };
@@ -111,11 +111,11 @@ static int gettok() {
     // Comment until end of line.
     do LastChar = getchar();
     while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
-    
+
     if (LastChar != EOF)
       return gettok();
   }
-  
+
   // Check for end of file.  Don't eat the EOF.
   if (LastChar == EOF)
     return tok_eof;
@@ -159,7 +159,7 @@ class UnaryExprAST : public ExprAST {
   char Opcode;
   ExprAST *Operand;
 public:
-  UnaryExprAST(char opcode, ExprAST *operand) 
+  UnaryExprAST(char opcode, ExprAST *operand)
     : Opcode(opcode), Operand(operand) {}
   virtual Value *Codegen();
 };
@@ -169,7 +169,7 @@ class BinaryExprAST : public ExprAST {
   char Op;
   ExprAST *LHS, *RHS;
 public:
-  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) 
+  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
     : Op(op), LHS(lhs), RHS(rhs) {}
   virtual Value *Codegen();
 };
@@ -212,7 +212,7 @@ public:
   VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
              ExprAST *body)
   : VarNames(varnames), Body(body) {}
-  
+
   virtual Value *Codegen();
 };
 
@@ -227,19 +227,19 @@ public:
   PrototypeAST(const std::string &name, const std::vector<std::string> &args,
                bool isoperator = false, unsigned prec = 0)
   : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
-  
+
   bool isUnaryOp() const { return isOperator && Args.size() == 1; }
   bool isBinaryOp() const { return isOperator && Args.size() == 2; }
-  
+
   char getOperatorName() const {
     assert(isUnaryOp() || isBinaryOp());
     return Name[Name.size()-1];
   }
-  
+
   unsigned getBinaryPrecedence() const { return Precedence; }
-  
+
   Function *Codegen();
-  
+
   void CreateArgumentAllocas(Function *F);
 };
 
@@ -250,7 +250,7 @@ class FunctionAST {
 public:
   FunctionAST(PrototypeAST *proto, ExprAST *body)
     : Proto(proto), Body(body) {}
-  
+
   Function *Codegen();
 };
 
@@ -274,7 +274,7 @@ static std::map<char, int> BinopPrecedence;
 static int GetTokPrecedence() {
   if (!isascii(CurTok))
     return -1;
-  
+
   // Make sure it's a declared binop.
   int TokPrec = BinopPrecedence[CurTok];
   if (TokPrec <= 0) return -1;
@@ -293,12 +293,12 @@ static ExprAST *ParseExpression();
 ///   ::= identifier '(' expression* ')'
 static ExprAST *ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
-  
+
   getNextToken();  // eat identifier.
-  
+
   if (CurTok != '(') // Simple variable ref.
     return new VariableExprAST(IdName);
-  
+
   // Call.
   getNextToken();  // eat (
   std::vector<ExprAST*> Args;
@@ -318,7 +318,7 @@ static ExprAST *ParseIdentifierExpr() {
 
   // Eat the ')'.
   getNextToken();
-  
+
   return new CallExprAST(IdName, Args);
 }
 
@@ -334,7 +334,7 @@ static ExprAST *ParseParenExpr() {
   getNextToken();  // eat (.
   ExprAST *V = ParseExpression();
   if (!V) return 0;
-  
+
   if (CurTok != ')')
     return Error("expected ')'");
   getNextToken();  // eat ).
@@ -344,26 +344,26 @@ static ExprAST *ParseParenExpr() {
 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
 static ExprAST *ParseIfExpr() {
   getNextToken();  // eat the if.
-  
+
   // condition.
   ExprAST *Cond = ParseExpression();
   if (!Cond) return 0;
-  
+
   if (CurTok != tok_then)
     return Error("expected then");
   getNextToken();  // eat the then
-  
+
   ExprAST *Then = ParseExpression();
   if (Then == 0) return 0;
-  
+
   if (CurTok != tok_else)
     return Error("expected else");
-  
+
   getNextToken();
-  
+
   ExprAST *Else = ParseExpression();
   if (!Else) return 0;
-  
+
   return new IfExprAST(Cond, Then, Else);
 }
 
@@ -373,24 +373,24 @@ static ExprAST *ParseForExpr() {
 
   if (CurTok != tok_identifier)
     return Error("expected identifier after for");
-  
+
   std::string IdName = IdentifierStr;
   getNextToken();  // eat identifier.
-  
+
   if (CurTok != '=')
     return Error("expected '=' after for");
   getNextToken();  // eat '='.
-  
-  
+
+
   ExprAST *Start = ParseExpression();
   if (Start == 0) return 0;
   if (CurTok != ',')
     return Error("expected ',' after for start value");
   getNextToken();
-  
+
   ExprAST *End = ParseExpression();
   if (End == 0) return 0;
-  
+
   // The step value is optional.
   ExprAST *Step = 0;
   if (CurTok == ',') {
@@ -398,18 +398,18 @@ static ExprAST *ParseForExpr() {
     Step = ParseExpression();
     if (Step == 0) return 0;
   }
-  
+
   if (CurTok != tok_in)
     return Error("expected 'in' after for");
   getNextToken();  // eat 'in'.
-  
+
   ExprAST *Body = ParseExpression();
   if (Body == 0) return 0;
 
   return new ForExprAST(IdName, Start, End, Step, Body);
 }
 
-/// varexpr ::= 'var' identifier ('=' expression)? 
+/// varexpr ::= 'var' identifier ('=' expression)?
 //                    (',' identifier ('=' expression)?)* 'in' expression
 static ExprAST *ParseVarExpr() {
   getNextToken();  // eat the var.
@@ -419,7 +419,7 @@ static ExprAST *ParseVarExpr() {
   // At least one variable name is required.
   if (CurTok != tok_identifier)
     return Error("expected identifier after var");
-  
+
   while (1) {
     std::string Name = IdentifierStr;
     getNextToken();  // eat identifier.
@@ -428,29 +428,29 @@ static ExprAST *ParseVarExpr() {
     ExprAST *Init = 0;
     if (CurTok == '=') {
       getNextToken(); // eat the '='.
-      
+
       Init = ParseExpression();
       if (Init == 0) return 0;
     }
-    
+
     VarNames.push_back(std::make_pair(Name, Init));
-    
+
     // End of var list, exit loop.
     if (CurTok != ',') break;
     getNextToken(); // eat the ','.
-    
+
     if (CurTok != tok_identifier)
       return Error("expected identifier list after var");
   }
-  
+
   // At this point, we have to have 'in'.
   if (CurTok != tok_in)
     return Error("expected 'in' keyword after 'var'");
   getNextToken();  // eat 'in'.
-  
+
   ExprAST *Body = ParseExpression();
   if (Body == 0) return 0;
-  
+
   return new VarExprAST(VarNames, Body);
 }
 
@@ -480,7 +480,7 @@ static ExprAST *ParseUnary() {
   // If the current token is not an operator, it must be a primary expr.
   if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
     return ParsePrimary();
-  
+
   // If this is a unary operator, read it.
   int Opc = CurTok;
   getNextToken();
@@ -495,20 +495,20 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
   // If this is a binop, find its precedence.
   while (1) {
     int TokPrec = GetTokPrecedence();
-    
+
     // If this is a binop that binds at least as tightly as the current binop,
     // consume it, otherwise we are done.
     if (TokPrec < ExprPrec)
       return LHS;
-    
+
     // Okay, we know this is a binop.
     int BinOp = CurTok;
     getNextToken();  // eat binop
-    
+
     // Parse the unary expression after the binary operator.
     ExprAST *RHS = ParseUnary();
     if (!RHS) return 0;
-    
+
     // If BinOp binds less tightly with RHS than the operator after RHS, let
     // the pending operator take RHS as its LHS.
     int NextPrec = GetTokPrecedence();
@@ -516,7 +516,7 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
       RHS = ParseBinOpRHS(TokPrec+1, RHS);
       if (RHS == 0) return 0;
     }
-    
+
     // Merge LHS/RHS.
     LHS = new BinaryExprAST(BinOp, LHS, RHS);
   }
@@ -528,7 +528,7 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
 static ExprAST *ParseExpression() {
   ExprAST *LHS = ParseUnary();
   if (!LHS) return 0;
-  
+
   return ParseBinOpRHS(0, LHS);
 }
 
@@ -538,10 +538,10 @@ static ExprAST *ParseExpression() {
 ///   ::= unary LETTER (id)
 static PrototypeAST *ParsePrototype() {
   std::string FnName;
-  
+
   unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
   unsigned BinaryPrecedence = 30;
-  
+
   switch (CurTok) {
   default:
     return ErrorP("Expected function name in prototype");
@@ -567,7 +567,7 @@ static PrototypeAST *ParsePrototype() {
     FnName += (char)CurTok;
     Kind = 2;
     getNextToken();
-    
+
     // Read the precedence if present.
     if (CurTok == tok_number) {
       if (NumVal < 1 || NumVal > 100)
@@ -577,23 +577,23 @@ static PrototypeAST *ParsePrototype() {
     }
     break;
   }
-  
+
   if (CurTok != '(')
     return ErrorP("Expected '(' in prototype");
-  
+
   std::vector<std::string> ArgNames;
   while (getNextToken() == tok_identifier)
     ArgNames.push_back(IdentifierStr);
   if (CurTok != ')')
     return ErrorP("Expected ')' in prototype");
-  
+
   // success.
   getNextToken();  // eat ')'.
-  
+
   // Verify right number of names for operator.
   if (Kind && ArgNames.size() != Kind)
     return ErrorP("Invalid number of operands for operator");
-  
+
   return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
 }
 
@@ -762,14 +762,14 @@ private:
 
 class HelpingMemoryManager : public SectionMemoryManager
 {
-  HelpingMemoryManager(const HelpingMemoryManager&) LLVM_DELETED_FUNCTION;
-  void operator=(const HelpingMemoryManager&) LLVM_DELETED_FUNCTION;
+  HelpingMemoryManager(const HelpingMemoryManager&) = delete;
+  void operator=(const HelpingMemoryManager&) = delete;
 
 public:
   HelpingMemoryManager(MCJITHelper *Helper) : MasterHelper(Helper) {}
   virtual ~HelpingMemoryManager() {}
 
-  /// This method returns the address of the specified function. 
+  /// This method returns the address of the specified function.
   /// Our implementation will attempt to find functions in other
   /// modules associated with the MCJITHelper to cross link functions
   /// from one generated module to another.
@@ -838,9 +838,9 @@ Function *MCJITHelper::getFunction(const std::string FnName) {
 
       // If we don't have a prototype yet, create one.
       if (!PF)
-        PF = Function::Create(F->getFunctionType(), 
-                                      Function::ExternalLinkage, 
-                                      FnName, 
+        PF = Function::Create(F->getFunctionType(),
+                                      Function::ExternalLinkage,
+                                      FnName,
                                       OpenModule);
       return PF;
     }
@@ -1027,11 +1027,11 @@ Value *VariableExprAST::Codegen() {
 Value *UnaryExprAST::Codegen() {
   Value *OperandV = Operand->Codegen();
   if (OperandV == 0) return 0;
-  
+
   Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("unary")+Opcode));
   if (F == 0)
     return ErrorV("Unknown unary operator");
-  
+
   return Builder.CreateCall(F, OperandV, "unop");
 }
 
@@ -1053,11 +1053,11 @@ Value *BinaryExprAST::Codegen() {
     Builder.CreateStore(Val, Variable);
     return Val;
   }
-  
+
   Value *L = LHS->Codegen();
   Value *R = RHS->Codegen();
   if (L == 0 || R == 0) return 0;
-  
+
   switch (Op) {
   case '+': return Builder.CreateFAdd(L, R, "addtmp");
   case '-': return Builder.CreateFSub(L, R, "subtmp");
@@ -1070,12 +1070,12 @@ Value *BinaryExprAST::Codegen() {
                                 "booltmp");
   default: break;
   }
-  
+
   // If it wasn't a builtin binary operator, it must be a user defined one. Emit
   // a call to it.
   Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("binary")+Op));
   assert(F && "binary operator not found!");
-  
+
   Value *Ops[] = { L, R };
   return Builder.CreateCall(F, Ops, "binop");
 }
@@ -1085,7 +1085,7 @@ Value *CallExprAST::Codegen() {
   Function *CalleeF = TheHelper->getFunction(Callee);
   if (CalleeF == 0)
     return ErrorV("Unknown function referenced");
-  
+
   // If argument mismatch error.
   if (CalleeF->arg_size() != Args.size())
     return ErrorV("Incorrect # arguments passed");
@@ -1095,56 +1095,56 @@ Value *CallExprAST::Codegen() {
     ArgsV.push_back(Args[i]->Codegen());
     if (ArgsV.back() == 0) return 0;
   }
-  
+
   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 }
 
 Value *IfExprAST::Codegen() {
   Value *CondV = Cond->Codegen();
   if (CondV == 0) return 0;
-  
+
   // Convert condition to a bool by comparing equal to 0.0.
-  CondV = Builder.CreateFCmpONE(CondV, 
+  CondV = Builder.CreateFCmpONE(CondV,
                               ConstantFP::get(getGlobalContext(), APFloat(0.0)),
                                 "ifcond");
-  
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
-  
+
   // Create blocks for the then and else cases.  Insert the 'then' block at the
   // end of the function.
   BasicBlock *ThenBB = BasicBlock::Create(getGlobalContext(), "then", TheFunction);
   BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
   BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
-  
+
   Builder.CreateCondBr(CondV, ThenBB, ElseBB);
-  
+
   // Emit then value.
   Builder.SetInsertPoint(ThenBB);
-  
+
   Value *ThenV = Then->Codegen();
   if (ThenV == 0) return 0;
-  
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
   ThenBB = Builder.GetInsertBlock();
-  
+
   // Emit else block.
   TheFunction->getBasicBlockList().push_back(ElseBB);
   Builder.SetInsertPoint(ElseBB);
-  
+
   Value *ElseV = Else->Codegen();
   if (ElseV == 0) return 0;
-  
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
   ElseBB = Builder.GetInsertBlock();
-  
+
   // Emit merge block.
   TheFunction->getBasicBlockList().push_back(MergeBB);
   Builder.SetInsertPoint(MergeBB);
   PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
                                   "iftmp");
-  
+
   PN->addIncoming(ThenV, ThenBB);
   PN->addIncoming(ElseV, ElseBB);
   return PN;
@@ -1157,7 +1157,7 @@ Value *ForExprAST::Codegen() {
   //   start = startexpr
   //   store start -> var
   //   goto loop
-  // loop: 
+  // loop:
   //   ...
   //   bodyexpr
   //   ...
@@ -1170,40 +1170,40 @@ Value *ForExprAST::Codegen() {
   //   store nextvar -> var
   //   br endcond, loop, endloop
   // outloop:
-  
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 
   // Create an alloca for the variable in the entry block.
   AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
-  
+
   // Emit the start code first, without 'variable' in scope.
   Value *StartVal = Start->Codegen();
   if (StartVal == 0) return 0;
-  
+
   // Store the value into the alloca.
   Builder.CreateStore(StartVal, Alloca);
-  
+
   // Make the new basic block for the loop header, inserting after current
   // block.
   BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
-  
+
   // Insert an explicit fall through from the current block to the LoopBB.
   Builder.CreateBr(LoopBB);
 
   // Start insertion in LoopBB.
   Builder.SetInsertPoint(LoopBB);
-  
+
   // Within the loop, the variable is defined equal to the PHI node.  If it
   // shadows an existing variable, we have to restore it, so save it now.
   AllocaInst *OldVal = NamedValues[VarName];
   NamedValues[VarName] = Alloca;
-  
+
   // Emit the body of the loop.  This, like any other expr, can change the
   // current BB.  Note that we ignore the value computed by the body, but don't
   // allow an error.
   if (Body->Codegen() == 0)
     return 0;
-  
+
   // Emit the step value.
   Value *StepVal;
   if (Step) {
@@ -1213,52 +1213,52 @@ Value *ForExprAST::Codegen() {
     // If not specified, use 1.0.
     StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
   }
-  
+
   // Compute the end condition.
   Value *EndCond = End->Codegen();
   if (EndCond == 0) return EndCond;
-  
+
   // Reload, increment, and restore the alloca.  This handles the case where
   // the body of the loop mutates the variable.
   Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
   Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
   Builder.CreateStore(NextVar, Alloca);
-  
+
   // Convert condition to a bool by comparing equal to 0.0.
-  EndCond = Builder.CreateFCmpONE(EndCond, 
+  EndCond = Builder.CreateFCmpONE(EndCond,
                               ConstantFP::get(getGlobalContext(), APFloat(0.0)),
                                   "loopcond");
-  
+
   // Create the "after loop" block and insert it.
   BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
-  
+
   // Insert the conditional branch into the end of LoopEndBB.
   Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
-  
+
   // Any new code will be inserted in AfterBB.
   Builder.SetInsertPoint(AfterBB);
-  
+
   // Restore the unshadowed variable.
   if (OldVal)
     NamedValues[VarName] = OldVal;
   else
     NamedValues.erase(VarName);
 
-  
+
   // for expr always returns 0.0.
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
 
 Value *VarExprAST::Codegen() {
   std::vector<AllocaInst *> OldBindings;
-  
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 
   // Register all variables and emit their initializer.
   for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
     const std::string &VarName = VarNames[i].first;
     ExprAST *Init = VarNames[i].second;
-    
+
     // Emit the initializer before adding the variable to scope, this prevents
     // the initializer from referencing the variable itself, and permits stuff
     // like this:
@@ -1271,22 +1271,22 @@ Value *VarExprAST::Codegen() {
     } else { // If not specified, use 0.0.
       InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
     }
-    
+
     AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
     Builder.CreateStore(InitVal, Alloca);
 
     // Remember the old variable binding so that we can restore the binding when
     // we unrecurse.
     OldBindings.push_back(NamedValues[VarName]);
-    
+
     // Remember this binding.
     NamedValues[VarName] = Alloca;
   }
-  
+
   // Codegen the body, now that all vars are in scope.
   Value *BodyVal = Body->Codegen();
   if (BodyVal == 0) return 0;
-  
+
   // Pop all our variables from scope.
   for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
     NamedValues[VarNames[i].first] = OldBindings[i];
@@ -1297,7 +1297,7 @@ Value *VarExprAST::Codegen() {
 
 Function *PrototypeAST::Codegen() {
   // Make the function type:  double(double,double) etc.
-  std::vector<Type*> Doubles(Args.size(), 
+  std::vector<Type*> Doubles(Args.size(),
                              Type::getDoubleTy(getGlobalContext()));
   FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
                                        Doubles, false);
@@ -1314,26 +1314,26 @@ Function *PrototypeAST::Codegen() {
     // Delete the one we just made and get the existing one.
     F->eraseFromParent();
     F = M->getFunction(Name);
-    
+
     // If F already has a body, reject this.
     if (!F->empty()) {
       ErrorF("redefinition of function");
       return 0;
     }
-    
+
     // If F took a different number of args, reject.
     if (F->arg_size() != Args.size()) {
       ErrorF("redefinition of function with different # args");
       return 0;
     }
   }
-  
+
   // Set names for all arguments.
   unsigned Idx = 0;
   for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
        ++AI, ++Idx)
     AI->setName(Args[Idx]);
-    
+
   return F;
 }
 
@@ -1355,19 +1355,19 @@ void PrototypeAST::CreateArgumentAllocas(Function *F) {
 
 Function *FunctionAST::Codegen() {
   NamedValues.clear();
-  
+
   Function *TheFunction = Proto->Codegen();
   if (TheFunction == 0)
     return 0;
-  
+
   // If this is an operator, install it.
   if (Proto->isBinaryOp())
     BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
-  
+
   // Create a new basic block to start insertion into.
   BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
   Builder.SetInsertPoint(BB);
-  
+
   // Add all arguments to the symbol table and create their allocas.
   Proto->CreateArgumentAllocas(TheFunction);
 
@@ -1428,7 +1428,7 @@ static void HandleTopLevelExpression() {
     if (Function *LF = F->Codegen()) {
       // JIT the function, returning a function pointer.
       void *FPtr = TheHelper->getPointerToFunction(LF);
-      
+
       // Cast it to the right type (takes no arguments, returns a double) so we
       // can call it as a native function.
       double (*FP)() = (double (*)())(intptr_t)FPtr;
@@ -1465,20 +1465,20 @@ static void MainLoop() {
 //===----------------------------------------------------------------------===//
 
 /// putchard - putchar that takes a double and returns 0.
-extern "C" 
+extern "C"
 double putchard(double X) {
   putchar((char)X);
   return 0;
 }
 
 /// printd - printf that takes a double prints it as "%f\n", returning 0.
-extern "C" 
+extern "C"
 double printd(double X) {
   printf("%f", X);
   return 0;
 }
 
-extern "C" 
+extern "C"
 double printlf() {
   printf("\n");
   return 0;
diff --git a/examples/Kaleidoscope/MCJIT/complete/toy.cpp b/examples/Kaleidoscope/MCJIT/complete/toy.cpp
index 3beb0d8..5294bb7 100644
--- a/examples/Kaleidoscope/MCJIT/complete/toy.cpp
+++ b/examples/Kaleidoscope/MCJIT/complete/toy.cpp
@@ -7,10 +7,10 @@
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/IRReader/IRReader.h"
-#include "llvm/PassManager.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
@@ -37,7 +37,7 @@ namespace {
               cl::value_desc("input IR file name"));
 
   cl::opt<bool>
-  VerboseOutput("verbose", 
+  VerboseOutput("verbose",
                 cl::desc("Enable verbose output (results, IR, etc.) to stderr"),
                 cl::init(false));
 
@@ -830,8 +830,8 @@ private:
 
 class HelpingMemoryManager : public SectionMemoryManager
 {
-  HelpingMemoryManager(const HelpingMemoryManager&) LLVM_DELETED_FUNCTION;
-  void operator=(const HelpingMemoryManager&) LLVM_DELETED_FUNCTION;
+  HelpingMemoryManager(const HelpingMemoryManager&) = delete;
+  void operator=(const HelpingMemoryManager&) = delete;
 
 public:
   HelpingMemoryManager(MCJITHelper *Helper) : MasterHelper(Helper) {}
diff --git a/examples/Kaleidoscope/MCJIT/initial/toy.cpp b/examples/Kaleidoscope/MCJIT/initial/toy.cpp
index 2c1b297..dd35358 100644
--- a/examples/Kaleidoscope/MCJIT/initial/toy.cpp
+++ b/examples/Kaleidoscope/MCJIT/initial/toy.cpp
@@ -6,9 +6,9 @@
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
-#include "llvm/PassManager.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Transforms/Scalar.h"
 #include <cctype>
@@ -32,14 +32,14 @@ enum Token {
 
   // primary
   tok_identifier = -4, tok_number = -5,
-  
+
   // control
   tok_if = -6, tok_then = -7, tok_else = -8,
   tok_for = -9, tok_in = -10,
-  
+
   // operators
   tok_binary = -11, tok_unary = -12,
-  
+
   // var definition
   tok_var = -13
 };
@@ -88,11 +88,11 @@ static int gettok() {
     // Comment until end of line.
     do LastChar = getchar();
     while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
-    
+
     if (LastChar != EOF)
       return gettok();
   }
-  
+
   // Check for end of file.  Don't eat the EOF.
   if (LastChar == EOF)
     return tok_eof;
@@ -136,7 +136,7 @@ class UnaryExprAST : public ExprAST {
   char Opcode;
   ExprAST *Operand;
 public:
-  UnaryExprAST(char opcode, ExprAST *operand) 
+  UnaryExprAST(char opcode, ExprAST *operand)
     : Opcode(opcode), Operand(operand) {}
   virtual Value *Codegen();
 };
@@ -146,7 +146,7 @@ class BinaryExprAST : public ExprAST {
   char Op;
   ExprAST *LHS, *RHS;
 public:
-  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) 
+  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
     : Op(op), LHS(lhs), RHS(rhs) {}
   virtual Value *Codegen();
 };
@@ -189,7 +189,7 @@ public:
   VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
              ExprAST *body)
   : VarNames(varnames), Body(body) {}
-  
+
   virtual Value *Codegen();
 };
 
@@ -204,19 +204,19 @@ public:
   PrototypeAST(const std::string &name, const std::vector<std::string> &args,
                bool isoperator = false, unsigned prec = 0)
   : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
-  
+
   bool isUnaryOp() const { return isOperator && Args.size() == 1; }
   bool isBinaryOp() const { return isOperator && Args.size() == 2; }
-  
+
   char getOperatorName() const {
     assert(isUnaryOp() || isBinaryOp());
     return Name[Name.size()-1];
   }
-  
+
   unsigned getBinaryPrecedence() const { return Precedence; }
-  
+
   Function *Codegen();
-  
+
   void CreateArgumentAllocas(Function *F);
 };
 
@@ -227,7 +227,7 @@ class FunctionAST {
 public:
   FunctionAST(PrototypeAST *proto, ExprAST *body)
     : Proto(proto), Body(body) {}
-  
+
   Function *Codegen();
 };
 
@@ -251,7 +251,7 @@ static std::map<char, int> BinopPrecedence;
 static int GetTokPrecedence() {
   if (!isascii(CurTok))
     return -1;
-  
+
   // Make sure it's a declared binop.
   int TokPrec = BinopPrecedence[CurTok];
   if (TokPrec <= 0) return -1;
@@ -270,12 +270,12 @@ static ExprAST *ParseExpression();
 ///   ::= identifier '(' expression* ')'
 static ExprAST *ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
-  
+
   getNextToken();  // eat identifier.
-  
+
   if (CurTok != '(') // Simple variable ref.
     return new VariableExprAST(IdName);
-  
+
   // Call.
   getNextToken();  // eat (
   std::vector<ExprAST*> Args;
@@ -295,7 +295,7 @@ static ExprAST *ParseIdentifierExpr() {
 
   // Eat the ')'.
   getNextToken();
-  
+
   return new CallExprAST(IdName, Args);
 }
 
@@ -311,7 +311,7 @@ static ExprAST *ParseParenExpr() {
   getNextToken();  // eat (.
   ExprAST *V = ParseExpression();
   if (!V) return 0;
-  
+
   if (CurTok != ')')
     return Error("expected ')'");
   getNextToken();  // eat ).
@@ -321,26 +321,26 @@ static ExprAST *ParseParenExpr() {
 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
 static ExprAST *ParseIfExpr() {
   getNextToken();  // eat the if.
-  
+
   // condition.
   ExprAST *Cond = ParseExpression();
   if (!Cond) return 0;
-  
+
   if (CurTok != tok_then)
     return Error("expected then");
   getNextToken();  // eat the then
-  
+
   ExprAST *Then = ParseExpression();
   if (Then == 0) return 0;
-  
+
   if (CurTok != tok_else)
     return Error("expected else");
-  
+
   getNextToken();
-  
+
   ExprAST *Else = ParseExpression();
   if (!Else) return 0;
-  
+
   return new IfExprAST(Cond, Then, Else);
 }
 
@@ -350,24 +350,24 @@ static ExprAST *ParseForExpr() {
 
   if (CurTok != tok_identifier)
     return Error("expected identifier after for");
-  
+
   std::string IdName = IdentifierStr;
   getNextToken();  // eat identifier.
-  
+
   if (CurTok != '=')
     return Error("expected '=' after for");
   getNextToken();  // eat '='.
-  
-  
+
+
   ExprAST *Start = ParseExpression();
   if (Start == 0) return 0;
   if (CurTok != ',')
     return Error("expected ',' after for start value");
   getNextToken();
-  
+
   ExprAST *End = ParseExpression();
   if (End == 0) return 0;
-  
+
   // The step value is optional.
   ExprAST *Step = 0;
   if (CurTok == ',') {
@@ -375,18 +375,18 @@ static ExprAST *ParseForExpr() {
     Step = ParseExpression();
     if (Step == 0) return 0;
   }
-  
+
   if (CurTok != tok_in)
     return Error("expected 'in' after for");
   getNextToken();  // eat 'in'.
-  
+
   ExprAST *Body = ParseExpression();
   if (Body == 0) return 0;
 
   return new ForExprAST(IdName, Start, End, Step, Body);
 }
 
-/// varexpr ::= 'var' identifier ('=' expression)? 
+/// varexpr ::= 'var' identifier ('=' expression)?
 //                    (',' identifier ('=' expression)?)* 'in' expression
 static ExprAST *ParseVarExpr() {
   getNextToken();  // eat the var.
@@ -396,7 +396,7 @@ static ExprAST *ParseVarExpr() {
   // At least one variable name is required.
   if (CurTok != tok_identifier)
     return Error("expected identifier after var");
-  
+
   while (1) {
     std::string Name = IdentifierStr;
     getNextToken();  // eat identifier.
@@ -405,29 +405,29 @@ static ExprAST *ParseVarExpr() {
     ExprAST *Init = 0;
     if (CurTok == '=') {
       getNextToken(); // eat the '='.
-      
+
       Init = ParseExpression();
       if (Init == 0) return 0;
     }
-    
+
     VarNames.push_back(std::make_pair(Name, Init));
-    
+
     // End of var list, exit loop.
     if (CurTok != ',') break;
     getNextToken(); // eat the ','.
-    
+
     if (CurTok != tok_identifier)
       return Error("expected identifier list after var");
   }
-  
+
   // At this point, we have to have 'in'.
   if (CurTok != tok_in)
     return Error("expected 'in' keyword after 'var'");
   getNextToken();  // eat 'in'.
-  
+
   ExprAST *Body = ParseExpression();
   if (Body == 0) return 0;
-  
+
   return new VarExprAST(VarNames, Body);
 }
 
@@ -457,7 +457,7 @@ static ExprAST *ParseUnary() {
   // If the current token is not an operator, it must be a primary expr.
   if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
     return ParsePrimary();
-  
+
   // If this is a unary operator, read it.
   int Opc = CurTok;
   getNextToken();
@@ -472,20 +472,20 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
   // If this is a binop, find its precedence.
   while (1) {
     int TokPrec = GetTokPrecedence();
-    
+
     // If this is a binop that binds at least as tightly as the current binop,
     // consume it, otherwise we are done.
     if (TokPrec < ExprPrec)
       return LHS;
-    
+
     // Okay, we know this is a binop.
     int BinOp = CurTok;
     getNextToken();  // eat binop
-    
+
     // Parse the unary expression after the binary operator.
     ExprAST *RHS = ParseUnary();
     if (!RHS) return 0;
-    
+
     // If BinOp binds less tightly with RHS than the operator after RHS, let
     // the pending operator take RHS as its LHS.
     int NextPrec = GetTokPrecedence();
@@ -493,7 +493,7 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
       RHS = ParseBinOpRHS(TokPrec+1, RHS);
       if (RHS == 0) return 0;
     }
-    
+
     // Merge LHS/RHS.
     LHS = new BinaryExprAST(BinOp, LHS, RHS);
   }
@@ -505,7 +505,7 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
 static ExprAST *ParseExpression() {
   ExprAST *LHS = ParseUnary();
   if (!LHS) return 0;
-  
+
   return ParseBinOpRHS(0, LHS);
 }
 
@@ -515,10 +515,10 @@ static ExprAST *ParseExpression() {
 ///   ::= unary LETTER (id)
 static PrototypeAST *ParsePrototype() {
   std::string FnName;
-  
+
   unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
   unsigned BinaryPrecedence = 30;
-  
+
   switch (CurTok) {
   default:
     return ErrorP("Expected function name in prototype");
@@ -544,7 +544,7 @@ static PrototypeAST *ParsePrototype() {
     FnName += (char)CurTok;
     Kind = 2;
     getNextToken();
-    
+
     // Read the precedence if present.
     if (CurTok == tok_number) {
       if (NumVal < 1 || NumVal > 100)
@@ -554,23 +554,23 @@ static PrototypeAST *ParsePrototype() {
     }
     break;
   }
-  
+
   if (CurTok != '(')
     return ErrorP("Expected '(' in prototype");
-  
+
   std::vector<std::string> ArgNames;
   while (getNextToken() == tok_identifier)
     ArgNames.push_back(IdentifierStr);
   if (CurTok != ')')
     return ErrorP("Expected ')' in prototype");
-  
+
   // success.
   getNextToken();  // eat ')'.
-  
+
   // Verify right number of names for operator.
   if (Kind && ArgNames.size() != Kind)
     return ErrorP("Invalid number of operands for operator");
-  
+
   return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
 }
 
@@ -670,14 +670,14 @@ private:
 
 class HelpingMemoryManager : public SectionMemoryManager
 {
-  HelpingMemoryManager(const HelpingMemoryManager&) LLVM_DELETED_FUNCTION;
-  void operator=(const HelpingMemoryManager&) LLVM_DELETED_FUNCTION;
+  HelpingMemoryManager(const HelpingMemoryManager&) = delete;
+  void operator=(const HelpingMemoryManager&) = delete;
 
 public:
   HelpingMemoryManager(MCJITHelper *Helper) : MasterHelper(Helper) {}
   virtual ~HelpingMemoryManager() {}
 
-  /// This method returns the address of the specified function. 
+  /// This method returns the address of the specified function.
   /// Our implementation will attempt to find functions in other
   /// modules associated with the MCJITHelper to cross link functions
   /// from one generated module to another.
@@ -739,9 +739,9 @@ Function *MCJITHelper::getFunction(const std::string FnName) {
 
       // If we don't have a prototype yet, create one.
       if (!PF)
-        PF = Function::Create(F->getFunctionType(), 
-                                      Function::ExternalLinkage, 
-                                      FnName, 
+        PF = Function::Create(F->getFunctionType(),
+                                      Function::ExternalLinkage,
+                                      FnName,
                                       OpenModule);
       return PF;
     }
@@ -885,11 +885,11 @@ Value *VariableExprAST::Codegen() {
 Value *UnaryExprAST::Codegen() {
   Value *OperandV = Operand->Codegen();
   if (OperandV == 0) return 0;
-  
+
   Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("unary")+Opcode));
   if (F == 0)
     return ErrorV("Unknown unary operator");
-  
+
   return Builder.CreateCall(F, OperandV, "unop");
 }
 
@@ -911,11 +911,11 @@ Value *BinaryExprAST::Codegen() {
     Builder.CreateStore(Val, Variable);
     return Val;
   }
-  
+
   Value *L = LHS->Codegen();
   Value *R = RHS->Codegen();
   if (L == 0 || R == 0) return 0;
-  
+
   switch (Op) {
   case '+': return Builder.CreateFAdd(L, R, "addtmp");
   case '-': return Builder.CreateFSub(L, R, "subtmp");
@@ -928,12 +928,12 @@ Value *BinaryExprAST::Codegen() {
                                 "booltmp");
   default: break;
   }
-  
+
   // If it wasn't a builtin binary operator, it must be a user defined one. Emit
   // a call to it.
   Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("binary")+Op));
   assert(F && "binary operator not found!");
-  
+
   Value *Ops[] = { L, R };
   return Builder.CreateCall(F, Ops, "binop");
 }
@@ -943,7 +943,7 @@ Value *CallExprAST::Codegen() {
   Function *CalleeF = TheHelper->getFunction(Callee);
   if (CalleeF == 0)
     return ErrorV("Unknown function referenced");
-  
+
   // If argument mismatch error.
   if (CalleeF->arg_size() != Args.size())
     return ErrorV("Incorrect # arguments passed");
@@ -953,56 +953,56 @@ Value *CallExprAST::Codegen() {
     ArgsV.push_back(Args[i]->Codegen());
     if (ArgsV.back() == 0) return 0;
   }
-  
+
   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 }
 
 Value *IfExprAST::Codegen() {
   Value *CondV = Cond->Codegen();
   if (CondV == 0) return 0;
-  
+
   // Convert condition to a bool by comparing equal to 0.0.
-  CondV = Builder.CreateFCmpONE(CondV, 
+  CondV = Builder.CreateFCmpONE(CondV,
                               ConstantFP::get(getGlobalContext(), APFloat(0.0)),
                                 "ifcond");
-  
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
-  
+
   // Create blocks for the then and else cases.  Insert the 'then' block at the
   // end of the function.
   BasicBlock *ThenBB = BasicBlock::Create(getGlobalContext(), "then", TheFunction);
   BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
   BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
-  
+
   Builder.CreateCondBr(CondV, ThenBB, ElseBB);
-  
+
   // Emit then value.
   Builder.SetInsertPoint(ThenBB);
-  
+
   Value *ThenV = Then->Codegen();
   if (ThenV == 0) return 0;
-  
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
   ThenBB = Builder.GetInsertBlock();
-  
+
   // Emit else block.
   TheFunction->getBasicBlockList().push_back(ElseBB);
   Builder.SetInsertPoint(ElseBB);
-  
+
   Value *ElseV = Else->Codegen();
   if (ElseV == 0) return 0;
-  
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
   ElseBB = Builder.GetInsertBlock();
-  
+
   // Emit merge block.
   TheFunction->getBasicBlockList().push_back(MergeBB);
   Builder.SetInsertPoint(MergeBB);
   PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
                                   "iftmp");
-  
+
   PN->addIncoming(ThenV, ThenBB);
   PN->addIncoming(ElseV, ElseBB);
   return PN;
@@ -1015,7 +1015,7 @@ Value *ForExprAST::Codegen() {
   //   start = startexpr
   //   store start -> var
   //   goto loop
-  // loop: 
+  // loop:
   //   ...
   //   bodyexpr
   //   ...
@@ -1028,40 +1028,40 @@ Value *ForExprAST::Codegen() {
   //   store nextvar -> var
   //   br endcond, loop, endloop
   // outloop:
-  
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 
   // Create an alloca for the variable in the entry block.
   AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
-  
+
   // Emit the start code first, without 'variable' in scope.
   Value *StartVal = Start->Codegen();
   if (StartVal == 0) return 0;
-  
+
   // Store the value into the alloca.
   Builder.CreateStore(StartVal, Alloca);
-  
+
   // Make the new basic block for the loop header, inserting after current
   // block.
   BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
-  
+
   // Insert an explicit fall through from the current block to the LoopBB.
   Builder.CreateBr(LoopBB);
 
   // Start insertion in LoopBB.
   Builder.SetInsertPoint(LoopBB);
-  
+
   // Within the loop, the variable is defined equal to the PHI node.  If it
   // shadows an existing variable, we have to restore it, so save it now.
   AllocaInst *OldVal = NamedValues[VarName];
   NamedValues[VarName] = Alloca;
-  
+
   // Emit the body of the loop.  This, like any other expr, can change the
   // current BB.  Note that we ignore the value computed by the body, but don't
   // allow an error.
   if (Body->Codegen() == 0)
     return 0;
-  
+
   // Emit the step value.
   Value *StepVal;
   if (Step) {
@@ -1071,52 +1071,52 @@ Value *ForExprAST::Codegen() {
     // If not specified, use 1.0.
     StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
   }
-  
+
   // Compute the end condition.
   Value *EndCond = End->Codegen();
   if (EndCond == 0) return EndCond;
-  
+
   // Reload, increment, and restore the alloca.  This handles the case where
   // the body of the loop mutates the variable.
   Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
   Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
   Builder.CreateStore(NextVar, Alloca);
-  
+
   // Convert condition to a bool by comparing equal to 0.0.
-  EndCond = Builder.CreateFCmpONE(EndCond, 
+  EndCond = Builder.CreateFCmpONE(EndCond,
                               ConstantFP::get(getGlobalContext(), APFloat(0.0)),
                                   "loopcond");
-  
+
   // Create the "after loop" block and insert it.
   BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
-  
+
   // Insert the conditional branch into the end of LoopEndBB.
   Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
-  
+
   // Any new code will be inserted in AfterBB.
   Builder.SetInsertPoint(AfterBB);
-  
+
   // Restore the unshadowed variable.
   if (OldVal)
     NamedValues[VarName] = OldVal;
   else
     NamedValues.erase(VarName);
 
-  
+
   // for expr always returns 0.0.
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
 
 Value *VarExprAST::Codegen() {
   std::vector<AllocaInst *> OldBindings;
-  
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 
   // Register all variables and emit their initializer.
   for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
     const std::string &VarName = VarNames[i].first;
     ExprAST *Init = VarNames[i].second;
-    
+
     // Emit the initializer before adding the variable to scope, this prevents
     // the initializer from referencing the variable itself, and permits stuff
     // like this:
@@ -1129,22 +1129,22 @@ Value *VarExprAST::Codegen() {
     } else { // If not specified, use 0.0.
       InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
     }
-    
+
     AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
     Builder.CreateStore(InitVal, Alloca);
 
     // Remember the old variable binding so that we can restore the binding when
     // we unrecurse.
     OldBindings.push_back(NamedValues[VarName]);
-    
+
     // Remember this binding.
     NamedValues[VarName] = Alloca;
   }
-  
+
   // Codegen the body, now that all vars are in scope.
   Value *BodyVal = Body->Codegen();
   if (BodyVal == 0) return 0;
-  
+
   // Pop all our variables from scope.
   for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
     NamedValues[VarNames[i].first] = OldBindings[i];
@@ -1155,7 +1155,7 @@ Value *VarExprAST::Codegen() {
 
 Function *PrototypeAST::Codegen() {
   // Make the function type:  double(double,double) etc.
-  std::vector<Type*> Doubles(Args.size(), 
+  std::vector<Type*> Doubles(Args.size(),
                              Type::getDoubleTy(getGlobalContext()));
   FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
                                        Doubles, false);
@@ -1172,26 +1172,26 @@ Function *PrototypeAST::Codegen() {
     // Delete the one we just made and get the existing one.
     F->eraseFromParent();
     F = M->getFunction(Name);
-    
+
     // If F already has a body, reject this.
     if (!F->empty()) {
       ErrorF("redefinition of function");
       return 0;
     }
-    
+
     // If F took a different number of args, reject.
     if (F->arg_size() != Args.size()) {
       ErrorF("redefinition of function with different # args");
       return 0;
     }
   }
-  
+
   // Set names for all arguments.
   unsigned Idx = 0;
   for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
        ++AI, ++Idx)
     AI->setName(Args[Idx]);
-    
+
   return F;
 }
 
@@ -1213,19 +1213,19 @@ void PrototypeAST::CreateArgumentAllocas(Function *F) {
 
 Function *FunctionAST::Codegen() {
   NamedValues.clear();
-  
+
   Function *TheFunction = Proto->Codegen();
   if (TheFunction == 0)
     return 0;
-  
+
   // If this is an operator, install it.
   if (Proto->isBinaryOp())
     BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
-  
+
   // Create a new basic block to start insertion into.
   BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
   Builder.SetInsertPoint(BB);
-  
+
   // Add all arguments to the symbol table and create their allocas.
   Proto->CreateArgumentAllocas(TheFunction);
 
@@ -1238,7 +1238,7 @@ Function *FunctionAST::Codegen() {
 
     return TheFunction;
   }
-  
+
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
 
@@ -1285,7 +1285,7 @@ static void HandleTopLevelExpression() {
     if (Function *LF = F->Codegen()) {
       // JIT the function, returning a function pointer.
       void *FPtr = TheHelper->getPointerToFunction(LF);
-      
+
       // Cast it to the right type (takes no arguments, returns a double) so we
       // can call it as a native function.
       double (*FP)() = (double (*)())(intptr_t)FPtr;
@@ -1322,20 +1322,20 @@ static void MainLoop() {
 //===----------------------------------------------------------------------===//
 
 /// putchard - putchar that takes a double and returns 0.
-extern "C" 
+extern "C"
 double putchard(double X) {
   putchar((char)X);
   return 0;
 }
 
 /// printd - printf that takes a double prints it as "%f\n", returning 0.
-extern "C" 
+extern "C"
 double printd(double X) {
   printf("%f", X);
   return 0;
 }
 
-extern "C" 
+extern "C"
 double printlf() {
   printf("\n");
   return 0;
diff --git a/examples/Kaleidoscope/MCJIT/lazy/toy-jit.cpp b/examples/Kaleidoscope/MCJIT/lazy/toy-jit.cpp
index 98c1001..07adbd4 100644
--- a/examples/Kaleidoscope/MCJIT/lazy/toy-jit.cpp
+++ b/examples/Kaleidoscope/MCJIT/lazy/toy-jit.cpp
@@ -6,9 +6,9 @@
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
-#include "llvm/PassManager.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Transforms/Scalar.h"
 #include <cctype>
diff --git a/examples/Kaleidoscope/MCJIT/lazy/toy.cpp b/examples/Kaleidoscope/MCJIT/lazy/toy.cpp
index 9c2a0d4..fe7fb61 100644
--- a/examples/Kaleidoscope/MCJIT/lazy/toy.cpp
+++ b/examples/Kaleidoscope/MCJIT/lazy/toy.cpp
@@ -8,9 +8,9 @@
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
-#include "llvm/PassManager.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Transforms/Scalar.h"
 #include <cctype>
@@ -34,14 +34,14 @@ enum Token {
 
   // primary
   tok_identifier = -4, tok_number = -5,
-  
+
   // control
   tok_if = -6, tok_then = -7, tok_else = -8,
   tok_for = -9, tok_in = -10,
-  
+
   // operators
   tok_binary = -11, tok_unary = -12,
-  
+
   // var definition
   tok_var = -13
 };
@@ -90,11 +90,11 @@ static int gettok() {
     // Comment until end of line.
     do LastChar = getchar();
     while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
-    
+
     if (LastChar != EOF)
       return gettok();
   }
-  
+
   // Check for end of file.  Don't eat the EOF.
   if (LastChar == EOF)
     return tok_eof;
@@ -138,7 +138,7 @@ class UnaryExprAST : public ExprAST {
   char Opcode;
   ExprAST *Operand;
 public:
-  UnaryExprAST(char opcode, ExprAST *operand) 
+  UnaryExprAST(char opcode, ExprAST *operand)
     : Opcode(opcode), Operand(operand) {}
   virtual Value *Codegen();
 };
@@ -148,7 +148,7 @@ class BinaryExprAST : public ExprAST {
   char Op;
   ExprAST *LHS, *RHS;
 public:
-  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) 
+  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
     : Op(op), LHS(lhs), RHS(rhs) {}
   virtual Value *Codegen();
 };
@@ -191,7 +191,7 @@ public:
   VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
              ExprAST *body)
   : VarNames(varnames), Body(body) {}
-  
+
   virtual Value *Codegen();
 };
 
@@ -206,19 +206,19 @@ public:
   PrototypeAST(const std::string &name, const std::vector<std::string> &args,
                bool isoperator = false, unsigned prec = 0)
   : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
-  
+
   bool isUnaryOp() const { return isOperator && Args.size() == 1; }
   bool isBinaryOp() const { return isOperator && Args.size() == 2; }
-  
+
   char getOperatorName() const {
     assert(isUnaryOp() || isBinaryOp());
     return Name[Name.size()-1];
   }
-  
+
   unsigned getBinaryPrecedence() const { return Precedence; }
-  
+
   Function *Codegen();
-  
+
   void CreateArgumentAllocas(Function *F);
 };
 
@@ -229,7 +229,7 @@ class FunctionAST {
 public:
   FunctionAST(PrototypeAST *proto, ExprAST *body)
     : Proto(proto), Body(body) {}
-  
+
   Function *Codegen();
 };
 
@@ -253,7 +253,7 @@ static std::map<char, int> BinopPrecedence;
 static int GetTokPrecedence() {
   if (!isascii(CurTok))
     return -1;
-  
+
   // Make sure it's a declared binop.
   int TokPrec = BinopPrecedence[CurTok];
   if (TokPrec <= 0) return -1;
@@ -272,12 +272,12 @@ static ExprAST *ParseExpression();
 ///   ::= identifier '(' expression* ')'
 static ExprAST *ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
-  
+
   getNextToken();  // eat identifier.
-  
+
   if (CurTok != '(') // Simple variable ref.
     return new VariableExprAST(IdName);
-  
+
   // Call.
   getNextToken();  // eat (
   std::vector<ExprAST*> Args;
@@ -297,7 +297,7 @@ static ExprAST *ParseIdentifierExpr() {
 
   // Eat the ')'.
   getNextToken();
-  
+
   return new CallExprAST(IdName, Args);
 }
 
@@ -313,7 +313,7 @@ static ExprAST *ParseParenExpr() {
   getNextToken();  // eat (.
   ExprAST *V = ParseExpression();
   if (!V) return 0;
-  
+
   if (CurTok != ')')
     return Error("expected ')'");
   getNextToken();  // eat ).
@@ -323,26 +323,26 @@ static ExprAST *ParseParenExpr() {
 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
 static ExprAST *ParseIfExpr() {
   getNextToken();  // eat the if.
-  
+
   // condition.
   ExprAST *Cond = ParseExpression();
   if (!Cond) return 0;
-  
+
   if (CurTok != tok_then)
     return Error("expected then");
   getNextToken();  // eat the then
-  
+
   ExprAST *Then = ParseExpression();
   if (Then == 0) return 0;
-  
+
   if (CurTok != tok_else)
     return Error("expected else");
-  
+
   getNextToken();
-  
+
   ExprAST *Else = ParseExpression();
   if (!Else) return 0;
-  
+
   return new IfExprAST(Cond, Then, Else);
 }
 
@@ -352,24 +352,24 @@ static ExprAST *ParseForExpr() {
 
   if (CurTok != tok_identifier)
     return Error("expected identifier after for");
-  
+
   std::string IdName = IdentifierStr;
   getNextToken();  // eat identifier.
-  
+
   if (CurTok != '=')
     return Error("expected '=' after for");
   getNextToken();  // eat '='.
-  
-  
+
+
   ExprAST *Start = ParseExpression();
   if (Start == 0) return 0;
   if (CurTok != ',')
     return Error("expected ',' after for start value");
   getNextToken();
-  
+
   ExprAST *End = ParseExpression();
   if (End == 0) return 0;
-  
+
   // The step value is optional.
   ExprAST *Step = 0;
   if (CurTok == ',') {
@@ -377,18 +377,18 @@ static ExprAST *ParseForExpr() {
     Step = ParseExpression();
     if (Step == 0) return 0;
   }
-  
+
   if (CurTok != tok_in)
     return Error("expected 'in' after for");
   getNextToken();  // eat 'in'.
-  
+
   ExprAST *Body = ParseExpression();
   if (Body == 0) return 0;
 
   return new ForExprAST(IdName, Start, End, Step, Body);
 }
 
-/// varexpr ::= 'var' identifier ('=' expression)? 
+/// varexpr ::= 'var' identifier ('=' expression)?
 //                    (',' identifier ('=' expression)?)* 'in' expression
 static ExprAST *ParseVarExpr() {
   getNextToken();  // eat the var.
@@ -398,7 +398,7 @@ static ExprAST *ParseVarExpr() {
   // At least one variable name is required.
   if (CurTok != tok_identifier)
     return Error("expected identifier after var");
-  
+
   while (1) {
     std::string Name = IdentifierStr;
     getNextToken();  // eat identifier.
@@ -407,29 +407,29 @@ static ExprAST *ParseVarExpr() {
     ExprAST *Init = 0;
     if (CurTok == '=') {
       getNextToken(); // eat the '='.
-      
+
       Init = ParseExpression();
       if (Init == 0) return 0;
     }
-    
+
     VarNames.push_back(std::make_pair(Name, Init));
-    
+
     // End of var list, exit loop.
     if (CurTok != ',') break;
     getNextToken(); // eat the ','.
-    
+
     if (CurTok != tok_identifier)
       return Error("expected identifier list after var");
   }
-  
+
   // At this point, we have to have 'in'.
   if (CurTok != tok_in)
     return Error("expected 'in' keyword after 'var'");
   getNextToken();  // eat 'in'.
-  
+
   ExprAST *Body = ParseExpression();
   if (Body == 0) return 0;
-  
+
   return new VarExprAST(VarNames, Body);
 }
 
@@ -459,7 +459,7 @@ static ExprAST *ParseUnary() {
   // If the current token is not an operator, it must be a primary expr.
   if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
     return ParsePrimary();
-  
+
   // If this is a unary operator, read it.
   int Opc = CurTok;
   getNextToken();
@@ -474,20 +474,20 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
   // If this is a binop, find its precedence.
   while (1) {
     int TokPrec = GetTokPrecedence();
-    
+
     // If this is a binop that binds at least as tightly as the current binop,
     // consume it, otherwise we are done.
     if (TokPrec < ExprPrec)
       return LHS;
-    
+
     // Okay, we know this is a binop.
     int BinOp = CurTok;
     getNextToken();  // eat binop
-    
+
     // Parse the unary expression after the binary operator.
     ExprAST *RHS = ParseUnary();
     if (!RHS) return 0;
-    
+
     // If BinOp binds less tightly with RHS than the operator after RHS, let
     // the pending operator take RHS as its LHS.
     int NextPrec = GetTokPrecedence();
@@ -495,7 +495,7 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
       RHS = ParseBinOpRHS(TokPrec+1, RHS);
       if (RHS == 0) return 0;
     }
-    
+
     // Merge LHS/RHS.
     LHS = new BinaryExprAST(BinOp, LHS, RHS);
   }
@@ -507,7 +507,7 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
 static ExprAST *ParseExpression() {
   ExprAST *LHS = ParseUnary();
   if (!LHS) return 0;
-  
+
   return ParseBinOpRHS(0, LHS);
 }
 
@@ -517,10 +517,10 @@ static ExprAST *ParseExpression() {
 ///   ::= unary LETTER (id)
 static PrototypeAST *ParsePrototype() {
   std::string FnName;
-  
+
   unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
   unsigned BinaryPrecedence = 30;
-  
+
   switch (CurTok) {
   default:
     return ErrorP("Expected function name in prototype");
@@ -546,7 +546,7 @@ static PrototypeAST *ParsePrototype() {
     FnName += (char)CurTok;
     Kind = 2;
     getNextToken();
-    
+
     // Read the precedence if present.
     if (CurTok == tok_number) {
       if (NumVal < 1 || NumVal > 100)
@@ -556,23 +556,23 @@ static PrototypeAST *ParsePrototype() {
     }
     break;
   }
-  
+
   if (CurTok != '(')
     return ErrorP("Expected '(' in prototype");
-  
+
   std::vector<std::string> ArgNames;
   while (getNextToken() == tok_identifier)
     ArgNames.push_back(IdentifierStr);
   if (CurTok != ')')
     return ErrorP("Expected ')' in prototype");
-  
+
   // success.
   getNextToken();  // eat ')'.
-  
+
   // Verify right number of names for operator.
   if (Kind && ArgNames.size() != Kind)
     return ErrorP("Invalid number of operands for operator");
-  
+
   return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
 }
 
@@ -673,14 +673,14 @@ private:
 
 class HelpingMemoryManager : public SectionMemoryManager
 {
-  HelpingMemoryManager(const HelpingMemoryManager&) LLVM_DELETED_FUNCTION;
-  void operator=(const HelpingMemoryManager&) LLVM_DELETED_FUNCTION;
+  HelpingMemoryManager(const HelpingMemoryManager&) = delete;
+  void operator=(const HelpingMemoryManager&) = delete;
 
 public:
   HelpingMemoryManager(MCJITHelper *Helper) : MasterHelper(Helper) {}
   virtual ~HelpingMemoryManager() {}
 
-  /// This method returns the address of the specified function. 
+  /// This method returns the address of the specified function.
   /// Our implementation will attempt to find functions in other
   /// modules associated with the MCJITHelper to cross link functions
   /// from one generated module to another.
@@ -749,9 +749,9 @@ Function *MCJITHelper::getFunction(const std::string FnName) {
 
       // If we don't have a prototype yet, create one.
       if (!PF)
-        PF = Function::Create(F->getFunctionType(), 
-                                      Function::ExternalLinkage, 
-                                      FnName, 
+        PF = Function::Create(F->getFunctionType(),
+                                      Function::ExternalLinkage,
+                                      FnName,
                                       OpenModule);
       return PF;
     }
@@ -925,11 +925,11 @@ Value *VariableExprAST::Codegen() {
 Value *UnaryExprAST::Codegen() {
   Value *OperandV = Operand->Codegen();
   if (OperandV == 0) return 0;
-  
+
   Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("unary")+Opcode));
   if (F == 0)
     return ErrorV("Unknown unary operator");
-  
+
   return Builder.CreateCall(F, OperandV, "unop");
 }
 
@@ -951,11 +951,11 @@ Value *BinaryExprAST::Codegen() {
     Builder.CreateStore(Val, Variable);
     return Val;
   }
-  
+
   Value *L = LHS->Codegen();
   Value *R = RHS->Codegen();
   if (L == 0 || R == 0) return 0;
-  
+
   switch (Op) {
   case '+': return Builder.CreateFAdd(L, R, "addtmp");
   case '-': return Builder.CreateFSub(L, R, "subtmp");
@@ -968,12 +968,12 @@ Value *BinaryExprAST::Codegen() {
                                 "booltmp");
   default: break;
   }
-  
+
   // If it wasn't a builtin binary operator, it must be a user defined one. Emit
   // a call to it.
   Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("binary")+Op));
   assert(F && "binary operator not found!");
-  
+
   Value *Ops[] = { L, R };
   return Builder.CreateCall(F, Ops, "binop");
 }
@@ -983,7 +983,7 @@ Value *CallExprAST::Codegen() {
   Function *CalleeF = TheHelper->getFunction(Callee);
   if (CalleeF == 0)
     return ErrorV("Unknown function referenced");
-  
+
   // If argument mismatch error.
   if (CalleeF->arg_size() != Args.size())
     return ErrorV("Incorrect # arguments passed");
@@ -993,56 +993,56 @@ Value *CallExprAST::Codegen() {
     ArgsV.push_back(Args[i]->Codegen());
     if (ArgsV.back() == 0) return 0;
   }
-  
+
   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 }
 
 Value *IfExprAST::Codegen() {
   Value *CondV = Cond->Codegen();
   if (CondV == 0) return 0;
-  
+
   // Convert condition to a bool by comparing equal to 0.0.
-  CondV = Builder.CreateFCmpONE(CondV, 
+  CondV = Builder.CreateFCmpONE(CondV,
                               ConstantFP::get(getGlobalContext(), APFloat(0.0)),
                                 "ifcond");
-  
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
-  
+
   // Create blocks for the then and else cases.  Insert the 'then' block at the
   // end of the function.
   BasicBlock *ThenBB = BasicBlock::Create(getGlobalContext(), "then", TheFunction);
   BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
   BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
-  
+
   Builder.CreateCondBr(CondV, ThenBB, ElseBB);
-  
+
   // Emit then value.
   Builder.SetInsertPoint(ThenBB);
-  
+
   Value *ThenV = Then->Codegen();
   if (ThenV == 0) return 0;
-  
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
   ThenBB = Builder.GetInsertBlock();
-  
+
   // Emit else block.
   TheFunction->getBasicBlockList().push_back(ElseBB);
   Builder.SetInsertPoint(ElseBB);
-  
+
   Value *ElseV = Else->Codegen();
   if (ElseV == 0) return 0;
-  
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
   ElseBB = Builder.GetInsertBlock();
-  
+
   // Emit merge block.
   TheFunction->getBasicBlockList().push_back(MergeBB);
   Builder.SetInsertPoint(MergeBB);
   PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
                                   "iftmp");
-  
+
   PN->addIncoming(ThenV, ThenBB);
   PN->addIncoming(ElseV, ElseBB);
   return PN;
@@ -1055,7 +1055,7 @@ Value *ForExprAST::Codegen() {
   //   start = startexpr
   //   store start -> var
   //   goto loop
-  // loop: 
+  // loop:
   //   ...
   //   bodyexpr
   //   ...
@@ -1068,40 +1068,40 @@ Value *ForExprAST::Codegen() {
   //   store nextvar -> var
   //   br endcond, loop, endloop
   // outloop:
-  
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 
   // Create an alloca for the variable in the entry block.
   AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
-  
+
   // Emit the start code first, without 'variable' in scope.
   Value *StartVal = Start->Codegen();
   if (StartVal == 0) return 0;
-  
+
   // Store the value into the alloca.
   Builder.CreateStore(StartVal, Alloca);
-  
+
   // Make the new basic block for the loop header, inserting after current
   // block.
   BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
-  
+
   // Insert an explicit fall through from the current block to the LoopBB.
   Builder.CreateBr(LoopBB);
 
   // Start insertion in LoopBB.
   Builder.SetInsertPoint(LoopBB);
-  
+
   // Within the loop, the variable is defined equal to the PHI node.  If it
   // shadows an existing variable, we have to restore it, so save it now.
   AllocaInst *OldVal = NamedValues[VarName];
   NamedValues[VarName] = Alloca;
-  
+
   // Emit the body of the loop.  This, like any other expr, can change the
   // current BB.  Note that we ignore the value computed by the body, but don't
   // allow an error.
   if (Body->Codegen() == 0)
     return 0;
-  
+
   // Emit the step value.
   Value *StepVal;
   if (Step) {
@@ -1111,52 +1111,52 @@ Value *ForExprAST::Codegen() {
     // If not specified, use 1.0.
     StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
   }
-  
+
   // Compute the end condition.
   Value *EndCond = End->Codegen();
   if (EndCond == 0) return EndCond;
-  
+
   // Reload, increment, and restore the alloca.  This handles the case where
   // the body of the loop mutates the variable.
   Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
   Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
   Builder.CreateStore(NextVar, Alloca);
-  
+
   // Convert condition to a bool by comparing equal to 0.0.
-  EndCond = Builder.CreateFCmpONE(EndCond, 
+  EndCond = Builder.CreateFCmpONE(EndCond,
                               ConstantFP::get(getGlobalContext(), APFloat(0.0)),
                                   "loopcond");
-  
+
   // Create the "after loop" block and insert it.
   BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
-  
+
   // Insert the conditional branch into the end of LoopEndBB.
   Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
-  
+
   // Any new code will be inserted in AfterBB.
   Builder.SetInsertPoint(AfterBB);
-  
+
   // Restore the unshadowed variable.
   if (OldVal)
     NamedValues[VarName] = OldVal;
   else
     NamedValues.erase(VarName);
 
-  
+
   // for expr always returns 0.0.
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
 
 Value *VarExprAST::Codegen() {
   std::vector<AllocaInst *> OldBindings;
-  
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 
   // Register all variables and emit their initializer.
   for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
     const std::string &VarName = VarNames[i].first;
     ExprAST *Init = VarNames[i].second;
-    
+
     // Emit the initializer before adding the variable to scope, this prevents
     // the initializer from referencing the variable itself, and permits stuff
     // like this:
@@ -1169,22 +1169,22 @@ Value *VarExprAST::Codegen() {
     } else { // If not specified, use 0.0.
       InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
     }
-    
+
     AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
     Builder.CreateStore(InitVal, Alloca);
 
     // Remember the old variable binding so that we can restore the binding when
     // we unrecurse.
     OldBindings.push_back(NamedValues[VarName]);
-    
+
     // Remember this binding.
     NamedValues[VarName] = Alloca;
   }
-  
+
   // Codegen the body, now that all vars are in scope.
   Value *BodyVal = Body->Codegen();
   if (BodyVal == 0) return 0;
-  
+
   // Pop all our variables from scope.
   for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
     NamedValues[VarNames[i].first] = OldBindings[i];
@@ -1195,7 +1195,7 @@ Value *VarExprAST::Codegen() {
 
 Function *PrototypeAST::Codegen() {
   // Make the function type:  double(double,double) etc.
-  std::vector<Type*> Doubles(Args.size(), 
+  std::vector<Type*> Doubles(Args.size(),
                              Type::getDoubleTy(getGlobalContext()));
   FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
                                        Doubles, false);
@@ -1212,26 +1212,26 @@ Function *PrototypeAST::Codegen() {
     // Delete the one we just made and get the existing one.
     F->eraseFromParent();
     F = M->getFunction(Name);
-    
+
     // If F already has a body, reject this.
     if (!F->empty()) {
       ErrorF("redefinition of function");
       return 0;
     }
-    
+
     // If F took a different number of args, reject.
     if (F->arg_size() != Args.size()) {
       ErrorF("redefinition of function with different # args");
       return 0;
     }
   }
-  
+
   // Set names for all arguments.
   unsigned Idx = 0;
   for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
        ++AI, ++Idx)
     AI->setName(Args[Idx]);
-    
+
   return F;
 }
 
@@ -1253,19 +1253,19 @@ void PrototypeAST::CreateArgumentAllocas(Function *F) {
 
 Function *FunctionAST::Codegen() {
   NamedValues.clear();
-  
+
   Function *TheFunction = Proto->Codegen();
   if (TheFunction == 0)
     return 0;
-  
+
   // If this is an operator, install it.
   if (Proto->isBinaryOp())
     BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
-  
+
   // Create a new basic block to start insertion into.
   BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
   Builder.SetInsertPoint(BB);
-  
+
   // Add all arguments to the symbol table and create their allocas.
   Proto->CreateArgumentAllocas(TheFunction);
 
@@ -1326,7 +1326,7 @@ static void HandleTopLevelExpression() {
     if (Function *LF = F->Codegen()) {
       // JIT the function, returning a function pointer.
       void *FPtr = TheHelper->getPointerToFunction(LF);
-      
+
       // Cast it to the right type (takes no arguments, returns a double) so we
       // can call it as a native function.
       double (*FP)() = (double (*)())(intptr_t)FPtr;
@@ -1363,20 +1363,20 @@ static void MainLoop() {
 //===----------------------------------------------------------------------===//
 
 /// putchard - putchar that takes a double and returns 0.
-extern "C" 
+extern "C"
 double putchard(double X) {
   putchar((char)X);
   return 0;
 }
 
 /// printd - printf that takes a double prints it as "%f\n", returning 0.
-extern "C" 
+extern "C"
 double printd(double X) {
   printf("%f", X);
   return 0;
 }
 
-extern "C" 
+extern "C"
 double printlf() {
   printf("\n");
   return 0;
diff --git a/examples/Kaleidoscope/Makefile b/examples/Kaleidoscope/Makefile
index bd0c252..8c3b1e3 100644
--- a/examples/Kaleidoscope/Makefile
+++ b/examples/Kaleidoscope/Makefile
@@ -10,6 +10,6 @@ LEVEL=../..
 
 include $(LEVEL)/Makefile.config
 
-PARALLEL_DIRS:= Chapter2 Chapter3 Chapter4 Chapter5 Chapter6 Chapter7
+PARALLEL_DIRS:= Chapter2 Chapter3 Chapter4 Chapter5 Chapter6 Chapter7 Chapter8
 
 include $(LEVEL)/Makefile.common
diff --git a/examples/Kaleidoscope/Orc/CMakeLists.txt b/examples/Kaleidoscope/Orc/CMakeLists.txt
new file mode 100644
index 0000000..5aa0454
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_subdirectory(initial)
+add_subdirectory(lazy_codegen)
+add_subdirectory(lazy_irgen)
+add_subdirectory(fully_lazy)
diff --git a/examples/Kaleidoscope/Orc/fully_lazy/CMakeLists.txt b/examples/Kaleidoscope/Orc/fully_lazy/CMakeLists.txt
new file mode 100644
index 0000000..abb0428
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/fully_lazy/CMakeLists.txt
@@ -0,0 +1,13 @@
+set(LLVM_LINK_COMPONENTS
+  Core
+  ExecutionEngine
+  Object
+  OrcJIT
+  RuntimeDyld
+  Support
+  native
+  )
+
+add_kaleidoscope_chapter(Kaleidoscope-Orc-fully_lazy
+  toy.cpp
+  )
diff --git a/examples/Kaleidoscope/Orc/fully_lazy/Makefile b/examples/Kaleidoscope/Orc/fully_lazy/Makefile
new file mode 100644
index 0000000..5536314
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/fully_lazy/Makefile
@@ -0,0 +1,17 @@
+UNAME := $(shell uname -s)
+
+ifeq ($(UNAME),Darwin)
+	CXX := xcrun --sdk macosx clang++
+else
+	CXX := clang++
+endif
+
+LLVM_CXXFLAGS := $(shell llvm-config --cxxflags)
+LLVM_LDFLAGS := $(shell llvm-config  --ldflags --system-libs --libs core orcjit native)
+
+toy: toy.cpp
+	$(CXX) $(LLVM_CXXFLAGS) -Wall -std=c++11 -g -O0 -rdynamic -fno-rtti -o toy toy.cpp $(LLVM_LDFLAGS)
+
+.PHONY: clean
+clean:
+	rm -f toy
diff --git a/examples/Kaleidoscope/Orc/fully_lazy/README.txt b/examples/Kaleidoscope/Orc/fully_lazy/README.txt
new file mode 100644
index 0000000..c018931
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/fully_lazy/README.txt
@@ -0,0 +1,21 @@
+//===----------------------------------------------------------------------===/
+//                 Kaleidoscope with Orc - Lazy IRGen Version
+//===----------------------------------------------------------------------===//
+
+This version of Kaleidoscope with Orc demonstrates fully lazy IR-generation.
+Building on the lazy-irgen version of the tutorial, this version injects JIT
+callbacks to defer the bulk of IR-generation and code-generation of functions until
+they are first called.
+
+When a function definition is entered, a JIT callback is created and a stub
+function is built that will call the body of the function indirectly. The body of
+the function is *not* IRGen'd at this point. Instead, the function pointer for
+the indirect call is initialized to point at the JIT callback, and the compile
+action for the callback is initialized with a lambda that IRGens the body of the
+function and adds it to the JIT. The function pointer is updated by the JIT
+callback's update action to point at the newly emitted function body, so future
+calls to the stub will go straight to the body, not through the JIT.
+
+This directory contains a Makefile that allows the code to be built in a
+standalone manner, independent of the larger LLVM build infrastructure. To build
+the program you will need to have 'clang++' and 'llvm-config' in your path.
diff --git a/examples/Kaleidoscope/Orc/fully_lazy/toy.cpp b/examples/Kaleidoscope/Orc/fully_lazy/toy.cpp
new file mode 100644
index 0000000..2e65756
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/fully_lazy/toy.cpp
@@ -0,0 +1,1437 @@
+#include "llvm/Analysis/Passes.h"
+#include "llvm/ExecutionEngine/Orc/CompileUtils.h"
+#include "llvm/ExecutionEngine/Orc/IRCompileLayer.h"
+#include "llvm/ExecutionEngine/Orc/LazyEmittingLayer.h"
+#include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
+#include "llvm/ExecutionEngine/Orc/OrcTargetSupport.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Transforms/Scalar.h"
+#include <cctype>
+#include <iomanip>
+#include <iostream>
+#include <map>
+#include <sstream>
+#include <string>
+#include <vector>
+
+using namespace llvm;
+using namespace llvm::orc;
+
+//===----------------------------------------------------------------------===//
+// Lexer
+//===----------------------------------------------------------------------===//
+
+// The lexer returns tokens [0-255] if it is an unknown character, otherwise one
+// of these for known things.
+enum Token {
+  tok_eof = -1,
+
+  // commands
+  tok_def = -2, tok_extern = -3,
+
+  // primary
+  tok_identifier = -4, tok_number = -5,
+  
+  // control
+  tok_if = -6, tok_then = -7, tok_else = -8,
+  tok_for = -9, tok_in = -10,
+  
+  // operators
+  tok_binary = -11, tok_unary = -12,
+  
+  // var definition
+  tok_var = -13
+};
+
+static std::string IdentifierStr;  // Filled in if tok_identifier
+static double NumVal;              // Filled in if tok_number
+
+/// gettok - Return the next token from standard input.
+static int gettok() {
+  static int LastChar = ' ';
+
+  // Skip any whitespace.
+  while (isspace(LastChar))
+    LastChar = getchar();
+
+  if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
+    IdentifierStr = LastChar;
+    while (isalnum((LastChar = getchar())))
+      IdentifierStr += LastChar;
+
+    if (IdentifierStr == "def") return tok_def;
+    if (IdentifierStr == "extern") return tok_extern;
+    if (IdentifierStr == "if") return tok_if;
+    if (IdentifierStr == "then") return tok_then;
+    if (IdentifierStr == "else") return tok_else;
+    if (IdentifierStr == "for") return tok_for;
+    if (IdentifierStr == "in") return tok_in;
+    if (IdentifierStr == "binary") return tok_binary;
+    if (IdentifierStr == "unary") return tok_unary;
+    if (IdentifierStr == "var") return tok_var;
+    return tok_identifier;
+  }
+
+  if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
+    std::string NumStr;
+    do {
+      NumStr += LastChar;
+      LastChar = getchar();
+    } while (isdigit(LastChar) || LastChar == '.');
+
+    NumVal = strtod(NumStr.c_str(), 0);
+    return tok_number;
+  }
+
+  if (LastChar == '#') {
+    // Comment until end of line.
+    do LastChar = getchar();
+    while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
+    
+    if (LastChar != EOF)
+      return gettok();
+  }
+  
+  // Check for end of file.  Don't eat the EOF.
+  if (LastChar == EOF)
+    return tok_eof;
+
+  // Otherwise, just return the character as its ascii value.
+  int ThisChar = LastChar;
+  LastChar = getchar();
+  return ThisChar;
+}
+
+//===----------------------------------------------------------------------===//
+// Abstract Syntax Tree (aka Parse Tree)
+//===----------------------------------------------------------------------===//
+
+class IRGenContext;
+
+/// ExprAST - Base class for all expression nodes.
+struct ExprAST {
+  virtual ~ExprAST() {}
+  virtual Value *IRGen(IRGenContext &C) const = 0;
+};
+
+/// NumberExprAST - Expression class for numeric literals like "1.0".
+struct NumberExprAST : public ExprAST {
+  NumberExprAST(double Val) : Val(Val) {}
+  Value *IRGen(IRGenContext &C) const override;
+
+  double Val;
+};
+
+/// VariableExprAST - Expression class for referencing a variable, like "a".
+struct VariableExprAST : public ExprAST {
+  VariableExprAST(std::string Name) : Name(std::move(Name)) {}
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::string Name;
+};
+
+/// UnaryExprAST - Expression class for a unary operator.
+struct UnaryExprAST : public ExprAST {
+  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand) 
+    : Opcode(std::move(Opcode)), Operand(std::move(Operand)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  char Opcode;
+  std::unique_ptr<ExprAST> Operand;
+};
+
+/// BinaryExprAST - Expression class for a binary operator.
+struct BinaryExprAST : public ExprAST {
+  BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
+                std::unique_ptr<ExprAST> RHS) 
+    : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  char Op;
+  std::unique_ptr<ExprAST> LHS, RHS;
+};
+
+/// CallExprAST - Expression class for function calls.
+struct CallExprAST : public ExprAST {
+  CallExprAST(std::string CalleeName,
+              std::vector<std::unique_ptr<ExprAST>> Args)
+    : CalleeName(std::move(CalleeName)), Args(std::move(Args)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::string CalleeName;
+  std::vector<std::unique_ptr<ExprAST>> Args;
+};
+
+/// IfExprAST - Expression class for if/then/else.
+struct IfExprAST : public ExprAST {
+  IfExprAST(std::unique_ptr<ExprAST> Cond, std::unique_ptr<ExprAST> Then,
+            std::unique_ptr<ExprAST> Else)
+    : Cond(std::move(Cond)), Then(std::move(Then)), Else(std::move(Else)) {}
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::unique_ptr<ExprAST> Cond, Then, Else;
+};
+
+/// ForExprAST - Expression class for for/in.
+struct ForExprAST : public ExprAST {
+  ForExprAST(std::string VarName, std::unique_ptr<ExprAST> Start,
+             std::unique_ptr<ExprAST> End, std::unique_ptr<ExprAST> Step,
+             std::unique_ptr<ExprAST> Body)
+    : VarName(std::move(VarName)), Start(std::move(Start)), End(std::move(End)),
+      Step(std::move(Step)), Body(std::move(Body)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::string VarName;
+  std::unique_ptr<ExprAST> Start, End, Step, Body;
+};
+
+/// VarExprAST - Expression class for var/in
+struct VarExprAST : public ExprAST {
+  typedef std::pair<std::string, std::unique_ptr<ExprAST>> Binding;
+  typedef std::vector<Binding> BindingList;
+
+  VarExprAST(BindingList VarBindings, std::unique_ptr<ExprAST> Body)
+    : VarBindings(std::move(VarBindings)), Body(std::move(Body)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  BindingList VarBindings;
+  std::unique_ptr<ExprAST> Body;
+};
+
+/// PrototypeAST - This class represents the "prototype" for a function,
+/// which captures its argument names as well as if it is an operator.
+struct PrototypeAST {
+  PrototypeAST(std::string Name, std::vector<std::string> Args,
+               bool IsOperator = false, unsigned Precedence = 0)
+    : Name(std::move(Name)), Args(std::move(Args)), IsOperator(IsOperator),
+      Precedence(Precedence) {}
+
+  Function *IRGen(IRGenContext &C) const;
+  void CreateArgumentAllocas(Function *F, IRGenContext &C);
+
+  bool isUnaryOp() const { return IsOperator && Args.size() == 1; }
+  bool isBinaryOp() const { return IsOperator && Args.size() == 2; }
+  
+  char getOperatorName() const {
+    assert(isUnaryOp() || isBinaryOp());
+    return Name[Name.size()-1];
+  }
+
+  std::string Name;
+  std::vector<std::string> Args;
+  bool IsOperator;
+  unsigned Precedence;  // Precedence if a binary op.
+};
+
+/// FunctionAST - This class represents a function definition itself.
+struct FunctionAST {
+  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
+              std::unique_ptr<ExprAST> Body)
+    : Proto(std::move(Proto)), Body(std::move(Body)) {}
+
+  Function *IRGen(IRGenContext &C) const;
+
+  std::unique_ptr<PrototypeAST> Proto;
+  std::unique_ptr<ExprAST> Body;
+};
+
+//===----------------------------------------------------------------------===//
+// Parser
+//===----------------------------------------------------------------------===//
+
+/// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
+/// token the parser is looking at.  getNextToken reads another token from the
+/// lexer and updates CurTok with its results.
+static int CurTok;
+static int getNextToken() {
+  return CurTok = gettok();
+}
+
+/// BinopPrecedence - This holds the precedence for each binary operator that is
+/// defined.
+static std::map<char, int> BinopPrecedence;
+
+/// GetTokPrecedence - Get the precedence of the pending binary operator token.
+static int GetTokPrecedence() {
+  if (!isascii(CurTok))
+    return -1;
+  
+  // Make sure it's a declared binop.
+  int TokPrec = BinopPrecedence[CurTok];
+  if (TokPrec <= 0) return -1;
+  return TokPrec;
+}
+
+template <typename T>
+std::unique_ptr<T> ErrorU(const std::string &Str) {
+  std::cerr << "Error: " << Str << "\n";
+  return nullptr;
+}
+
+template <typename T>
+T* ErrorP(const std::string &Str) {
+  std::cerr << "Error: " << Str << "\n";
+  return nullptr;
+}
+
+static std::unique_ptr<ExprAST> ParseExpression();
+
+/// identifierexpr
+///   ::= identifier
+///   ::= identifier '(' expression* ')'
+static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
+  std::string IdName = IdentifierStr;
+  
+  getNextToken();  // eat identifier.
+  
+  if (CurTok != '(') // Simple variable ref.
+    return llvm::make_unique<VariableExprAST>(IdName);
+  
+  // Call.
+  getNextToken();  // eat (
+  std::vector<std::unique_ptr<ExprAST>> Args;
+  if (CurTok != ')') {
+    while (1) {
+      auto Arg = ParseExpression();
+      if (!Arg) return nullptr;
+      Args.push_back(std::move(Arg));
+
+      if (CurTok == ')') break;
+
+      if (CurTok != ',')
+        return ErrorU<CallExprAST>("Expected ')' or ',' in argument list");
+      getNextToken();
+    }
+  }
+
+  // Eat the ')'.
+  getNextToken();
+  
+  return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
+}
+
+/// numberexpr ::= number
+static std::unique_ptr<NumberExprAST> ParseNumberExpr() {
+  auto Result = llvm::make_unique<NumberExprAST>(NumVal);
+  getNextToken(); // consume the number
+  return Result;
+}
+
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+  getNextToken();  // eat (.
+  auto V = ParseExpression();
+  if (!V)
+    return nullptr;
+  
+  if (CurTok != ')')
+    return ErrorU<ExprAST>("expected ')'");
+  getNextToken();  // eat ).
+  return V;
+}
+
+/// ifexpr ::= 'if' expression 'then' expression 'else' expression
+static std::unique_ptr<ExprAST> ParseIfExpr() {
+  getNextToken();  // eat the if.
+  
+  // condition.
+  auto Cond = ParseExpression();
+  if (!Cond)
+    return nullptr;
+  
+  if (CurTok != tok_then)
+    return ErrorU<ExprAST>("expected then");
+  getNextToken();  // eat the then
+  
+  auto Then = ParseExpression();
+  if (!Then)
+    return nullptr;
+  
+  if (CurTok != tok_else)
+    return ErrorU<ExprAST>("expected else");
+  
+  getNextToken();
+  
+  auto Else = ParseExpression();
+  if (!Else)
+    return nullptr;
+  
+  return llvm::make_unique<IfExprAST>(std::move(Cond), std::move(Then),
+                                      std::move(Else));
+}
+
+/// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
+static std::unique_ptr<ForExprAST> ParseForExpr() {
+  getNextToken();  // eat the for.
+
+  if (CurTok != tok_identifier)
+    return ErrorU<ForExprAST>("expected identifier after for");
+  
+  std::string IdName = IdentifierStr;
+  getNextToken();  // eat identifier.
+  
+  if (CurTok != '=')
+    return ErrorU<ForExprAST>("expected '=' after for");
+  getNextToken();  // eat '='.
+  
+  
+  auto Start = ParseExpression();
+  if (!Start)
+    return nullptr;
+  if (CurTok != ',')
+    return ErrorU<ForExprAST>("expected ',' after for start value");
+  getNextToken();
+  
+  auto End = ParseExpression();
+  if (!End)
+    return nullptr;
+  
+  // The step value is optional.
+  std::unique_ptr<ExprAST> Step;
+  if (CurTok == ',') {
+    getNextToken();
+    Step = ParseExpression();
+    if (!Step)
+      return nullptr;
+  }
+  
+  if (CurTok != tok_in)
+    return ErrorU<ForExprAST>("expected 'in' after for");
+  getNextToken();  // eat 'in'.
+  
+  auto Body = ParseExpression();
+  if (Body)
+    return nullptr;
+
+  return llvm::make_unique<ForExprAST>(IdName, std::move(Start), std::move(End),
+                                       std::move(Step), std::move(Body));
+}
+
+/// varexpr ::= 'var' identifier ('=' expression)? 
+//                    (',' identifier ('=' expression)?)* 'in' expression
+static std::unique_ptr<VarExprAST> ParseVarExpr() {
+  getNextToken();  // eat the var.
+
+  VarExprAST::BindingList VarBindings;
+
+  // At least one variable name is required.
+  if (CurTok != tok_identifier)
+    return ErrorU<VarExprAST>("expected identifier after var");
+  
+  while (1) {
+    std::string Name = IdentifierStr;
+    getNextToken();  // eat identifier.
+
+    // Read the optional initializer.
+    std::unique_ptr<ExprAST> Init;
+    if (CurTok == '=') {
+      getNextToken(); // eat the '='.
+      
+      Init = ParseExpression();
+      if (!Init)
+        return nullptr;
+    }
+    
+    VarBindings.push_back(VarExprAST::Binding(Name, std::move(Init)));
+    
+    // End of var list, exit loop.
+    if (CurTok != ',') break;
+    getNextToken(); // eat the ','.
+    
+    if (CurTok != tok_identifier)
+      return ErrorU<VarExprAST>("expected identifier list after var");
+  }
+  
+  // At this point, we have to have 'in'.
+  if (CurTok != tok_in)
+    return ErrorU<VarExprAST>("expected 'in' keyword after 'var'");
+  getNextToken();  // eat 'in'.
+  
+  auto Body = ParseExpression();
+  if (!Body)
+    return nullptr;
+  
+  return llvm::make_unique<VarExprAST>(std::move(VarBindings), std::move(Body));
+}
+
+/// primary
+///   ::= identifierexpr
+///   ::= numberexpr
+///   ::= parenexpr
+///   ::= ifexpr
+///   ::= forexpr
+///   ::= varexpr
+static std::unique_ptr<ExprAST> ParsePrimary() {
+  switch (CurTok) {
+  default: return ErrorU<ExprAST>("unknown token when expecting an expression");
+  case tok_identifier: return ParseIdentifierExpr();
+  case tok_number:     return ParseNumberExpr();
+  case '(':            return ParseParenExpr();
+  case tok_if:         return ParseIfExpr();
+  case tok_for:        return ParseForExpr();
+  case tok_var:        return ParseVarExpr();
+  }
+}
+
+/// unary
+///   ::= primary
+///   ::= '!' unary
+static std::unique_ptr<ExprAST> ParseUnary() {
+  // If the current token is not an operator, it must be a primary expr.
+  if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
+    return ParsePrimary();
+  
+  // If this is a unary operator, read it.
+  int Opc = CurTok;
+  getNextToken();
+  if (auto Operand = ParseUnary())
+    return llvm::make_unique<UnaryExprAST>(Opc, std::move(Operand));
+  return nullptr;
+}
+
+/// binoprhs
+///   ::= ('+' unary)*
+static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
+                                              std::unique_ptr<ExprAST> LHS) {
+  // If this is a binop, find its precedence.
+  while (1) {
+    int TokPrec = GetTokPrecedence();
+    
+    // If this is a binop that binds at least as tightly as the current binop,
+    // consume it, otherwise we are done.
+    if (TokPrec < ExprPrec)
+      return LHS;
+    
+    // Okay, we know this is a binop.
+    int BinOp = CurTok;
+    getNextToken();  // eat binop
+    
+    // Parse the unary expression after the binary operator.
+    auto RHS = ParseUnary();
+    if (!RHS)
+      return nullptr;
+    
+    // If BinOp binds less tightly with RHS than the operator after RHS, let
+    // the pending operator take RHS as its LHS.
+    int NextPrec = GetTokPrecedence();
+    if (TokPrec < NextPrec) {
+      RHS = ParseBinOpRHS(TokPrec+1, std::move(RHS));
+      if (!RHS)
+        return nullptr;
+    }
+    
+    // Merge LHS/RHS.
+    LHS = llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
+  }
+}
+
+/// expression
+///   ::= unary binoprhs
+///
+static std::unique_ptr<ExprAST> ParseExpression() {
+  auto LHS = ParseUnary();
+  if (!LHS)
+    return nullptr;
+  
+  return ParseBinOpRHS(0, std::move(LHS));
+}
+
+/// prototype
+///   ::= id '(' id* ')'
+///   ::= binary LETTER number? (id, id)
+///   ::= unary LETTER (id)
+static std::unique_ptr<PrototypeAST> ParsePrototype() {
+  std::string FnName;
+  
+  unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
+  unsigned BinaryPrecedence = 30;
+  
+  switch (CurTok) {
+  default:
+    return ErrorU<PrototypeAST>("Expected function name in prototype");
+  case tok_identifier:
+    FnName = IdentifierStr;
+    Kind = 0;
+    getNextToken();
+    break;
+  case tok_unary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorU<PrototypeAST>("Expected unary operator");
+    FnName = "unary";
+    FnName += (char)CurTok;
+    Kind = 1;
+    getNextToken();
+    break;
+  case tok_binary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorU<PrototypeAST>("Expected binary operator");
+    FnName = "binary";
+    FnName += (char)CurTok;
+    Kind = 2;
+    getNextToken();
+    
+    // Read the precedence if present.
+    if (CurTok == tok_number) {
+      if (NumVal < 1 || NumVal > 100)
+        return ErrorU<PrototypeAST>("Invalid precedecnce: must be 1..100");
+      BinaryPrecedence = (unsigned)NumVal;
+      getNextToken();
+    }
+    break;
+  }
+  
+  if (CurTok != '(')
+    return ErrorU<PrototypeAST>("Expected '(' in prototype");
+  
+  std::vector<std::string> ArgNames;
+  while (getNextToken() == tok_identifier)
+    ArgNames.push_back(IdentifierStr);
+  if (CurTok != ')')
+    return ErrorU<PrototypeAST>("Expected ')' in prototype");
+  
+  // success.
+  getNextToken();  // eat ')'.
+  
+  // Verify right number of names for operator.
+  if (Kind && ArgNames.size() != Kind)
+    return ErrorU<PrototypeAST>("Invalid number of operands for operator");
+  
+  return llvm::make_unique<PrototypeAST>(FnName, std::move(ArgNames), Kind != 0,
+                                         BinaryPrecedence);
+}
+
+/// definition ::= 'def' prototype expression
+static std::unique_ptr<FunctionAST> ParseDefinition() {
+  getNextToken();  // eat def.
+  auto Proto = ParsePrototype();
+  if (!Proto)
+    return nullptr;
+
+  if (auto Body = ParseExpression())
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(Body));
+  return nullptr;
+}
+
+/// toplevelexpr ::= expression
+static std::unique_ptr<FunctionAST> ParseTopLevelExpr() {
+  if (auto E = ParseExpression()) {
+    // Make an anonymous proto.
+    auto Proto =
+      llvm::make_unique<PrototypeAST>("__anon_expr", std::vector<std::string>());
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
+  }
+  return nullptr;
+}
+
+/// external ::= 'extern' prototype
+static std::unique_ptr<PrototypeAST> ParseExtern() {
+  getNextToken();  // eat extern.
+  return ParsePrototype();
+}
+
+//===----------------------------------------------------------------------===//
+// Code Generation
+//===----------------------------------------------------------------------===//
+
+// FIXME: Obviously we can do better than this
+std::string GenerateUniqueName(const std::string &Root) {
+  static int i = 0;
+  std::ostringstream NameStream;
+  NameStream << Root << ++i;
+  return NameStream.str();
+}
+
+std::string MakeLegalFunctionName(std::string Name)
+{
+  std::string NewName;
+  assert(!Name.empty() && "Base name must not be empty");
+
+  // Start with what we have
+  NewName = Name;
+
+  // Look for a numberic first character
+  if (NewName.find_first_of("0123456789") == 0) {
+    NewName.insert(0, 1, 'n');
+  }
+
+  // Replace illegal characters with their ASCII equivalent
+  std::string legal_elements = "_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+  size_t pos;
+  while ((pos = NewName.find_first_not_of(legal_elements)) != std::string::npos) {
+    std::ostringstream NumStream;
+    NumStream << (int)NewName.at(pos);
+    NewName = NewName.replace(pos, 1, NumStream.str());
+  }
+
+  return NewName;
+}
+
+class SessionContext {
+public:
+  SessionContext(LLVMContext &C)
+    : Context(C), TM(EngineBuilder().selectTarget()) {}
+  LLVMContext& getLLVMContext() const { return Context; }
+  TargetMachine& getTarget() { return *TM; }
+  void addPrototypeAST(std::unique_ptr<PrototypeAST> P);
+  PrototypeAST* getPrototypeAST(const std::string &Name);
+private:
+  typedef std::map<std::string, std::unique_ptr<PrototypeAST>> PrototypeMap;
+  
+  LLVMContext &Context;
+  std::unique_ptr<TargetMachine> TM;
+      
+  PrototypeMap Prototypes;
+};
+
+void SessionContext::addPrototypeAST(std::unique_ptr<PrototypeAST> P) {
+  Prototypes[P->Name] = std::move(P);
+}
+
+PrototypeAST* SessionContext::getPrototypeAST(const std::string &Name) {
+  PrototypeMap::iterator I = Prototypes.find(Name);
+  if (I != Prototypes.end())
+    return I->second.get();
+  return nullptr;
+}
+
+class IRGenContext {
+public:
+
+  IRGenContext(SessionContext &S)
+    : Session(S),
+      M(new Module(GenerateUniqueName("jit_module_"),
+                   Session.getLLVMContext())),
+      Builder(Session.getLLVMContext()) {
+    M->setDataLayout(Session.getTarget().getDataLayout());
+  }
+
+  SessionContext& getSession() { return Session; }
+  Module& getM() const { return *M; }
+  std::unique_ptr<Module> takeM() { return std::move(M); }
+  IRBuilder<>& getBuilder() { return Builder; }
+  LLVMContext& getLLVMContext() { return Session.getLLVMContext(); }
+  Function* getPrototype(const std::string &Name);
+
+  std::map<std::string, AllocaInst*> NamedValues;
+private:
+  SessionContext &Session;
+  std::unique_ptr<Module> M;
+  IRBuilder<> Builder;
+};
+
+Function* IRGenContext::getPrototype(const std::string &Name) {
+  if (Function *ExistingProto = M->getFunction(Name))
+    return ExistingProto;
+  if (PrototypeAST *ProtoAST = Session.getPrototypeAST(Name))
+    return ProtoAST->IRGen(*this);
+  return nullptr;
+}
+
+/// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
+/// the function.  This is used for mutable variables etc.
+static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
+                                          const std::string &VarName) {
+  IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
+                 TheFunction->getEntryBlock().begin());
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+                           VarName.c_str());
+}
+
+Value *NumberExprAST::IRGen(IRGenContext &C) const {
+  return ConstantFP::get(C.getLLVMContext(), APFloat(Val));
+}
+
+Value *VariableExprAST::IRGen(IRGenContext &C) const {
+  // Look this variable up in the function.
+  Value *V = C.NamedValues[Name];
+
+  if (V == 0)
+    return ErrorP<Value>("Unknown variable name '" + Name + "'");
+
+  // Load the value.
+  return C.getBuilder().CreateLoad(V, Name.c_str());
+}
+
+Value *UnaryExprAST::IRGen(IRGenContext &C) const {
+  if (Value *OperandV = Operand->IRGen(C)) {
+    std::string FnName = MakeLegalFunctionName(std::string("unary")+Opcode);
+    if (Function *F = C.getPrototype(FnName))
+      return C.getBuilder().CreateCall(F, OperandV, "unop");
+    return ErrorP<Value>("Unknown unary operator");
+  }
+
+  // Could not codegen operand - return null.
+  return nullptr;
+}
+
+Value *BinaryExprAST::IRGen(IRGenContext &C) const {
+  // Special case '=' because we don't want to emit the LHS as an expression.
+  if (Op == '=') {
+    // Assignment requires the LHS to be an identifier.
+    auto LHSVar = static_cast<VariableExprAST&>(*LHS);
+    // Codegen the RHS.
+    Value *Val = RHS->IRGen(C);
+    if (!Val) return nullptr;
+
+    // Look up the name.
+    if (auto Variable = C.NamedValues[LHSVar.Name]) {
+      C.getBuilder().CreateStore(Val, Variable);
+      return Val;
+    }
+    return ErrorP<Value>("Unknown variable name");
+  }
+  
+  Value *L = LHS->IRGen(C);
+  Value *R = RHS->IRGen(C);
+  if (!L || !R) return nullptr;
+  
+  switch (Op) {
+  case '+': return C.getBuilder().CreateFAdd(L, R, "addtmp");
+  case '-': return C.getBuilder().CreateFSub(L, R, "subtmp");
+  case '*': return C.getBuilder().CreateFMul(L, R, "multmp");
+  case '/': return C.getBuilder().CreateFDiv(L, R, "divtmp");
+  case '<':
+    L = C.getBuilder().CreateFCmpULT(L, R, "cmptmp");
+    // Convert bool 0/1 to double 0.0 or 1.0
+    return C.getBuilder().CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
+                                "booltmp");
+  default: break;
+  }
+  
+  // If it wasn't a builtin binary operator, it must be a user defined one. Emit
+  // a call to it.
+  std::string FnName = MakeLegalFunctionName(std::string("binary")+Op);
+  if (Function *F = C.getPrototype(FnName)) {
+    Value *Ops[] = { L, R };
+    return C.getBuilder().CreateCall(F, Ops, "binop");
+  }
+   
+  return ErrorP<Value>("Unknown binary operator");
+}
+
+Value *CallExprAST::IRGen(IRGenContext &C) const {
+  // Look up the name in the global module table.
+  if (auto CalleeF = C.getPrototype(CalleeName)) {
+    // If argument mismatch error.
+    if (CalleeF->arg_size() != Args.size())
+      return ErrorP<Value>("Incorrect # arguments passed");
+
+    std::vector<Value*> ArgsV;
+    for (unsigned i = 0, e = Args.size(); i != e; ++i) {
+      ArgsV.push_back(Args[i]->IRGen(C));
+      if (!ArgsV.back()) return nullptr;
+    }
+    
+    return C.getBuilder().CreateCall(CalleeF, ArgsV, "calltmp");
+  }
+
+  return ErrorP<Value>("Unknown function referenced");
+}
+
+Value *IfExprAST::IRGen(IRGenContext &C) const {
+  Value *CondV = Cond->IRGen(C);
+  if (!CondV) return nullptr;
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  ConstantFP *FPZero = 
+    ConstantFP::get(C.getLLVMContext(), APFloat(0.0));
+  CondV = C.getBuilder().CreateFCmpONE(CondV, FPZero, "ifcond");
+  
+  Function *TheFunction = C.getBuilder().GetInsertBlock()->getParent();
+  
+  // Create blocks for the then and else cases.  Insert the 'then' block at the
+  // end of the function.
+  BasicBlock *ThenBB = BasicBlock::Create(C.getLLVMContext(), "then", TheFunction);
+  BasicBlock *ElseBB = BasicBlock::Create(C.getLLVMContext(), "else");
+  BasicBlock *MergeBB = BasicBlock::Create(C.getLLVMContext(), "ifcont");
+  
+  C.getBuilder().CreateCondBr(CondV, ThenBB, ElseBB);
+  
+  // Emit then value.
+  C.getBuilder().SetInsertPoint(ThenBB);
+  
+  Value *ThenV = Then->IRGen(C);
+  if (!ThenV) return nullptr;
+  
+  C.getBuilder().CreateBr(MergeBB);
+  // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
+  ThenBB = C.getBuilder().GetInsertBlock();
+  
+  // Emit else block.
+  TheFunction->getBasicBlockList().push_back(ElseBB);
+  C.getBuilder().SetInsertPoint(ElseBB);
+  
+  Value *ElseV = Else->IRGen(C);
+  if (!ElseV) return nullptr;
+  
+  C.getBuilder().CreateBr(MergeBB);
+  // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
+  ElseBB = C.getBuilder().GetInsertBlock();
+  
+  // Emit merge block.
+  TheFunction->getBasicBlockList().push_back(MergeBB);
+  C.getBuilder().SetInsertPoint(MergeBB);
+  PHINode *PN = C.getBuilder().CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
+                                  "iftmp");
+  
+  PN->addIncoming(ThenV, ThenBB);
+  PN->addIncoming(ElseV, ElseBB);
+  return PN;
+}
+
+Value *ForExprAST::IRGen(IRGenContext &C) const {
+  // Output this as:
+  //   var = alloca double
+  //   ...
+  //   start = startexpr
+  //   store start -> var
+  //   goto loop
+  // loop: 
+  //   ...
+  //   bodyexpr
+  //   ...
+  // loopend:
+  //   step = stepexpr
+  //   endcond = endexpr
+  //
+  //   curvar = load var
+  //   nextvar = curvar + step
+  //   store nextvar -> var
+  //   br endcond, loop, endloop
+  // outloop:
+  
+  Function *TheFunction = C.getBuilder().GetInsertBlock()->getParent();
+
+  // Create an alloca for the variable in the entry block.
+  AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+  
+  // Emit the start code first, without 'variable' in scope.
+  Value *StartVal = Start->IRGen(C);
+  if (!StartVal) return nullptr;
+  
+  // Store the value into the alloca.
+  C.getBuilder().CreateStore(StartVal, Alloca);
+  
+  // Make the new basic block for the loop header, inserting after current
+  // block.
+  BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
+  
+  // Insert an explicit fall through from the current block to the LoopBB.
+  C.getBuilder().CreateBr(LoopBB);
+
+  // Start insertion in LoopBB.
+  C.getBuilder().SetInsertPoint(LoopBB);
+  
+  // Within the loop, the variable is defined equal to the PHI node.  If it
+  // shadows an existing variable, we have to restore it, so save it now.
+  AllocaInst *OldVal = C.NamedValues[VarName];
+  C.NamedValues[VarName] = Alloca;
+  
+  // Emit the body of the loop.  This, like any other expr, can change the
+  // current BB.  Note that we ignore the value computed by the body, but don't
+  // allow an error.
+  if (!Body->IRGen(C))
+    return nullptr;
+  
+  // Emit the step value.
+  Value *StepVal;
+  if (Step) {
+    StepVal = Step->IRGen(C);
+    if (!StepVal) return nullptr;
+  } else {
+    // If not specified, use 1.0.
+    StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
+  }
+  
+  // Compute the end condition.
+  Value *EndCond = End->IRGen(C);
+  if (EndCond == 0) return EndCond;
+  
+  // Reload, increment, and restore the alloca.  This handles the case where
+  // the body of the loop mutates the variable.
+  Value *CurVar = C.getBuilder().CreateLoad(Alloca, VarName.c_str());
+  Value *NextVar = C.getBuilder().CreateFAdd(CurVar, StepVal, "nextvar");
+  C.getBuilder().CreateStore(NextVar, Alloca);
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  EndCond = C.getBuilder().CreateFCmpONE(EndCond, 
+                              ConstantFP::get(getGlobalContext(), APFloat(0.0)),
+                                  "loopcond");
+  
+  // Create the "after loop" block and insert it.
+  BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
+  
+  // Insert the conditional branch into the end of LoopEndBB.
+  C.getBuilder().CreateCondBr(EndCond, LoopBB, AfterBB);
+  
+  // Any new code will be inserted in AfterBB.
+  C.getBuilder().SetInsertPoint(AfterBB);
+  
+  // Restore the unshadowed variable.
+  if (OldVal)
+    C.NamedValues[VarName] = OldVal;
+  else
+    C.NamedValues.erase(VarName);
+
+  
+  // for expr always returns 0.0.
+  return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
+}
+
+Value *VarExprAST::IRGen(IRGenContext &C) const {
+  std::vector<AllocaInst *> OldBindings;
+  
+  Function *TheFunction = C.getBuilder().GetInsertBlock()->getParent();
+
+  // Register all variables and emit their initializer.
+  for (unsigned i = 0, e = VarBindings.size(); i != e; ++i) {
+    auto &VarName = VarBindings[i].first;
+    auto &Init = VarBindings[i].second;
+    
+    // Emit the initializer before adding the variable to scope, this prevents
+    // the initializer from referencing the variable itself, and permits stuff
+    // like this:
+    //  var a = 1 in
+    //    var a = a in ...   # refers to outer 'a'.
+    Value *InitVal;
+    if (Init) {
+      InitVal = Init->IRGen(C);
+      if (!InitVal) return nullptr;
+    } else // If not specified, use 0.0.
+      InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
+    
+    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+    C.getBuilder().CreateStore(InitVal, Alloca);
+
+    // Remember the old variable binding so that we can restore the binding when
+    // we unrecurse.
+    OldBindings.push_back(C.NamedValues[VarName]);
+    
+    // Remember this binding.
+    C.NamedValues[VarName] = Alloca;
+  }
+  
+  // Codegen the body, now that all vars are in scope.
+  Value *BodyVal = Body->IRGen(C);
+  if (!BodyVal) return nullptr;
+  
+  // Pop all our variables from scope.
+  for (unsigned i = 0, e = VarBindings.size(); i != e; ++i)
+    C.NamedValues[VarBindings[i].first] = OldBindings[i];
+
+  // Return the body computation.
+  return BodyVal;
+}
+
+Function *PrototypeAST::IRGen(IRGenContext &C) const {
+  std::string FnName = MakeLegalFunctionName(Name);
+
+  // Make the function type:  double(double,double) etc.
+  std::vector<Type*> Doubles(Args.size(), 
+                             Type::getDoubleTy(getGlobalContext()));
+  FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
+                                       Doubles, false);
+  Function *F = Function::Create(FT, Function::ExternalLinkage, FnName,
+                                 &C.getM());
+
+  // If F conflicted, there was already something named 'FnName'.  If it has a
+  // body, don't allow redefinition or reextern.
+  if (F->getName() != FnName) {
+    // Delete the one we just made and get the existing one.
+    F->eraseFromParent();
+    F = C.getM().getFunction(Name);
+    
+    // If F already has a body, reject this.
+    if (!F->empty()) {
+      ErrorP<Function>("redefinition of function");
+      return nullptr;
+    }
+    
+    // If F took a different number of args, reject.
+    if (F->arg_size() != Args.size()) {
+      ErrorP<Function>("redefinition of function with different # args");
+      return nullptr;
+    }
+  }
+  
+  // Set names for all arguments.
+  unsigned Idx = 0;
+  for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
+       ++AI, ++Idx)
+    AI->setName(Args[Idx]);
+    
+  return F;
+}
+
+/// CreateArgumentAllocas - Create an alloca for each argument and register the
+/// argument in the symbol table so that references to it will succeed.
+void PrototypeAST::CreateArgumentAllocas(Function *F, IRGenContext &C) {
+  Function::arg_iterator AI = F->arg_begin();
+  for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
+    // Create an alloca for this variable.
+    AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
+
+    // Store the initial value into the alloca.
+    C.getBuilder().CreateStore(AI, Alloca);
+
+    // Add arguments to variable symbol table.
+    C.NamedValues[Args[Idx]] = Alloca;
+  }
+}
+
+Function *FunctionAST::IRGen(IRGenContext &C) const {
+  C.NamedValues.clear();
+  
+  Function *TheFunction = Proto->IRGen(C);
+  if (!TheFunction)
+    return nullptr;
+  
+  // If this is an operator, install it.
+  if (Proto->isBinaryOp())
+    BinopPrecedence[Proto->getOperatorName()] = Proto->Precedence;
+  
+  // Create a new basic block to start insertion into.
+  BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
+  C.getBuilder().SetInsertPoint(BB);
+  
+  // Add all arguments to the symbol table and create their allocas.
+  Proto->CreateArgumentAllocas(TheFunction, C);
+
+  if (Value *RetVal = Body->IRGen(C)) {
+    // Finish off the function.
+    C.getBuilder().CreateRet(RetVal);
+
+    // Validate the generated code, checking for consistency.
+    verifyFunction(*TheFunction);
+
+    return TheFunction;
+  }
+  
+  // Error reading body, remove function.
+  TheFunction->eraseFromParent();
+
+  if (Proto->isBinaryOp())
+    BinopPrecedence.erase(Proto->getOperatorName());
+  return nullptr;
+}
+
+//===----------------------------------------------------------------------===//
+// Top-Level parsing and JIT Driver
+//===----------------------------------------------------------------------===//
+
+static std::unique_ptr<llvm::Module> IRGen(SessionContext &S,
+                                           const FunctionAST &F) {
+  IRGenContext C(S);
+  auto LF = F.IRGen(C);
+  if (!LF)
+    return nullptr;
+#ifndef MINIMAL_STDERR_OUTPUT
+  fprintf(stderr, "Read function definition:");
+  LF->dump();
+#endif
+  return C.takeM();
+}
+
+template <typename T>
+static std::vector<T> singletonSet(T t) {
+  std::vector<T> Vec;
+  Vec.push_back(std::move(t));
+  return Vec;
+}
+
+static void EarthShatteringKaboom() {
+  fprintf(stderr, "Earth shattering kaboom.");
+  exit(1);
+}
+
+class KaleidoscopeJIT {
+public:
+  typedef ObjectLinkingLayer<> ObjLayerT;
+  typedef IRCompileLayer<ObjLayerT> CompileLayerT;
+  typedef LazyEmittingLayer<CompileLayerT> LazyEmitLayerT;
+  typedef LazyEmitLayerT::ModuleSetHandleT ModuleHandleT;
+
+  KaleidoscopeJIT(SessionContext &Session)
+    : Session(Session),
+      Mang(Session.getTarget().getDataLayout()),
+      ObjectLayer(
+        [](){ return llvm::make_unique<SectionMemoryManager>(); }),
+      CompileLayer(ObjectLayer, SimpleCompiler(Session.getTarget())),
+      LazyEmitLayer(CompileLayer),
+      CompileCallbacks(LazyEmitLayer, Session.getLLVMContext(),
+                       reinterpret_cast<uintptr_t>(EarthShatteringKaboom),
+                       64) {}
+
+  std::string mangle(const std::string &Name) {
+    std::string MangledName;
+    {
+      raw_string_ostream MangledNameStream(MangledName);
+      Mang.getNameWithPrefix(MangledNameStream, Name);
+    }
+    return MangledName;
+  }
+
+  void addFunctionDefinition(std::unique_ptr<FunctionAST> FnAST) {
+    FunctionDefs[mangle(FnAST->Proto->Name)] = std::move(FnAST);
+  }
+
+  ModuleHandleT addModule(std::unique_ptr<Module> M) {
+    // We need a memory manager to allocate memory and resolve symbols for this
+    // new module. Create one that resolves symbols by looking back into the
+    // JIT.
+    auto MM = createLookasideRTDyldMM<SectionMemoryManager>(
+                [&](const std::string &Name) {
+                  // First try to find 'Name' within the JIT.
+                  if (auto Symbol = findSymbol(Name))
+                    return Symbol.getAddress();
+
+                  // If we don't already have a definition of 'Name' then search
+                  // the ASTs.
+                  return searchUncompiledASTs(Name);
+                },
+                [](const std::string &S) { return 0; } );
+
+    return LazyEmitLayer.addModuleSet(singletonSet(std::move(M)),
+                                      std::move(MM));
+  }
+
+  void removeModule(ModuleHandleT H) { LazyEmitLayer.removeModuleSet(H); }
+
+  JITSymbol findSymbol(const std::string &Name) {
+    return LazyEmitLayer.findSymbol(Name, true);
+  }
+
+  JITSymbol findSymbolIn(ModuleHandleT H, const std::string &Name) {
+    return LazyEmitLayer.findSymbolIn(H, Name, true);
+  }
+
+  JITSymbol findUnmangledSymbol(const std::string &Name) {
+    return findSymbol(mangle(Name));
+  }
+
+  JITSymbol findUnmangledSymbolIn(ModuleHandleT H, const std::string &Name) {
+    return findSymbolIn(H, mangle(Name));
+  }
+
+private:
+
+  // This method searches the FunctionDefs map for a definition of 'Name'. If it
+  // finds one it generates a stub for it and returns the address of the stub.
+  TargetAddress searchUncompiledASTs(const std::string &Name) {
+    auto DefI = FunctionDefs.find(Name);
+    if (DefI == FunctionDefs.end())
+      return 0;
+
+    // We have AST for 'Name'. IRGen a stub for it and add it to the JIT.
+    // FIXME: What happens if IRGen fails?
+    auto H = irGenStub(std::move(DefI->second));
+
+    // Remove the function definition's AST now that we're
+    // finished with it.
+    FunctionDefs.erase(DefI);
+
+    // Return the address of the stub.
+    return findSymbolIn(H, Name).getAddress();
+  }
+
+  // This method will take the AST for a function definition and IR-gen a stub
+  // for that function that will, on first call, IR-gen the actual body of the
+  // function.
+  ModuleHandleT irGenStub(std::unique_ptr<FunctionAST> FnAST) {
+    // Step 1) IRGen a prototype for the stub. This will have the same type as
+    //         the function.
+    IRGenContext C(Session);
+    Function *F = FnAST->Proto->IRGen(C);
+
+    // Step 2) Get a compile callback that can be used to compile the body of
+    //         the function. The resulting CallbackInfo type will let us set the
+    //         compile and update actions for the callback, and get a pointer to
+    //         the jit trampoline that we need to call to trigger those actions.
+    auto CallbackInfo =
+      CompileCallbacks.getCompileCallback(*F->getFunctionType());
+
+    // Step 3) Create a stub that will indirectly call the body of this
+    //         function once it is compiled. Initially, set the function
+    //         pointer for the indirection to point at the trampoline.
+    std::string BodyPtrName = (F->getName() + "$address").str();
+    GlobalVariable *FunctionBodyPointer =
+      createImplPointer(*F, BodyPtrName, CallbackInfo.getAddress());
+    makeStub(*F, *FunctionBodyPointer);
+
+    // Step 4) Add the module containing the stub to the JIT.
+    auto H = addModule(C.takeM());
+
+    // Step 5) Set the compile and update actions.
+    //
+    //   The compile action will IRGen the function and add it to the JIT, then
+    // request its address, which will trigger codegen. Since we don't need the
+    // AST after this, we pass ownership of the AST into the compile action:
+    // compile actions (and update actions) are deleted after they're run, so
+    // this will free the AST for us.
+    //
+    //   The update action will update FunctionBodyPointer to point at the newly
+    // compiled function.
+    std::shared_ptr<FunctionAST> Fn = std::move(FnAST);
+    CallbackInfo.setCompileAction([this, Fn]() {
+      auto H = addModule(IRGen(Session, *Fn));
+      return findUnmangledSymbolIn(H, Fn->Proto->Name).getAddress();
+    });
+    CallbackInfo.setUpdateAction(
+      CompileCallbacks.getLocalFPUpdater(H, mangle(BodyPtrName)));
+
+    return H;
+  }
+
+  SessionContext &Session;
+  Mangler Mang;
+  ObjLayerT ObjectLayer;
+  CompileLayerT CompileLayer;
+  LazyEmitLayerT LazyEmitLayer;
+
+  std::map<std::string, std::unique_ptr<FunctionAST>> FunctionDefs;
+
+  JITCompileCallbackManager<LazyEmitLayerT, OrcX86_64> CompileCallbacks;
+};
+
+static void HandleDefinition(SessionContext &S, KaleidoscopeJIT &J) {
+  if (auto F = ParseDefinition()) {
+    S.addPrototypeAST(llvm::make_unique<PrototypeAST>(*F->Proto));
+    J.addFunctionDefinition(std::move(F));
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleExtern(SessionContext &S) {
+  if (auto P = ParseExtern())
+    S.addPrototypeAST(std::move(P));
+  else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleTopLevelExpression(SessionContext &S, KaleidoscopeJIT &J) {
+  // Evaluate a top-level expression into an anonymous function.
+  if (auto F = ParseTopLevelExpr()) {
+    IRGenContext C(S);
+    if (auto ExprFunc = F->IRGen(C)) {
+#ifndef MINIMAL_STDERR_OUTPUT
+      std::cerr << "Expression function:\n";
+      ExprFunc->dump();
+#endif
+      // Add the CodeGen'd module to the JIT. Keep a handle to it: We can remove
+      // this module as soon as we've executed Function ExprFunc.
+      auto H = J.addModule(C.takeM());
+
+      // Get the address of the JIT'd function in memory.
+      auto ExprSymbol = J.findUnmangledSymbol("__anon_expr");
+      
+      // Cast it to the right type (takes no arguments, returns a double) so we
+      // can call it as a native function.
+      double (*FP)() = (double (*)())(intptr_t)ExprSymbol.getAddress();
+#ifdef MINIMAL_STDERR_OUTPUT
+      FP();
+#else
+      std::cerr << "Evaluated to " << FP() << "\n";
+#endif
+
+      // Remove the function.
+      J.removeModule(H);
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+/// top ::= definition | external | expression | ';'
+static void MainLoop() {
+  SessionContext S(getGlobalContext());
+  KaleidoscopeJIT J(S);
+
+  while (1) {
+    switch (CurTok) {
+    case tok_eof:    return;
+    case ';':        getNextToken(); continue;  // ignore top-level semicolons.
+    case tok_def:    HandleDefinition(S, J); break;
+    case tok_extern: HandleExtern(S); break;
+    default:         HandleTopLevelExpression(S, J); break;
+    }
+#ifndef MINIMAL_STDERR_OUTPUT
+    std::cerr << "ready> ";
+#endif
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// "Library" functions that can be "extern'd" from user code.
+//===----------------------------------------------------------------------===//
+
+/// putchard - putchar that takes a double and returns 0.
+extern "C" 
+double putchard(double X) {
+  putchar((char)X);
+  return 0;
+}
+
+/// printd - printf that takes a double prints it as "%f\n", returning 0.
+extern "C" 
+double printd(double X) {
+  printf("%f", X);
+  return 0;
+}
+
+extern "C" 
+double printlf() {
+  printf("\n");
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Main driver code.
+//===----------------------------------------------------------------------===//
+
+int main() {
+  InitializeNativeTarget();
+  InitializeNativeTargetAsmPrinter();
+  InitializeNativeTargetAsmParser();
+
+  // Install standard binary operators.
+  // 1 is lowest precedence.
+  BinopPrecedence['='] = 2;
+  BinopPrecedence['<'] = 10;
+  BinopPrecedence['+'] = 20;
+  BinopPrecedence['-'] = 20;
+  BinopPrecedence['/'] = 40;
+  BinopPrecedence['*'] = 40;  // highest.
+
+  // Prime the first token.
+#ifndef MINIMAL_STDERR_OUTPUT
+  std::cerr << "ready> ";
+#endif
+  getNextToken();
+
+  std::cerr << std::fixed;
+
+  // Run the main "interpreter loop" now.
+  MainLoop();
+
+  return 0;
+}
+
diff --git a/examples/Kaleidoscope/Orc/initial/CMakeLists.txt b/examples/Kaleidoscope/Orc/initial/CMakeLists.txt
new file mode 100644
index 0000000..4f21e1c
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/initial/CMakeLists.txt
@@ -0,0 +1,12 @@
+set(LLVM_LINK_COMPONENTS
+  Core
+  ExecutionEngine
+  Object
+  RuntimeDyld
+  Support
+  native
+  )
+
+add_kaleidoscope_chapter(Kaleidoscope-Orc-initial
+  toy.cpp
+  )
diff --git a/examples/Kaleidoscope/Orc/initial/Makefile b/examples/Kaleidoscope/Orc/initial/Makefile
new file mode 100644
index 0000000..5536314
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/initial/Makefile
@@ -0,0 +1,17 @@
+UNAME := $(shell uname -s)
+
+ifeq ($(UNAME),Darwin)
+	CXX := xcrun --sdk macosx clang++
+else
+	CXX := clang++
+endif
+
+LLVM_CXXFLAGS := $(shell llvm-config --cxxflags)
+LLVM_LDFLAGS := $(shell llvm-config  --ldflags --system-libs --libs core orcjit native)
+
+toy: toy.cpp
+	$(CXX) $(LLVM_CXXFLAGS) -Wall -std=c++11 -g -O0 -rdynamic -fno-rtti -o toy toy.cpp $(LLVM_LDFLAGS)
+
+.PHONY: clean
+clean:
+	rm -f toy
diff --git a/examples/Kaleidoscope/Orc/initial/README.txt b/examples/Kaleidoscope/Orc/initial/README.txt
new file mode 100644
index 0000000..5f4cbbf
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/initial/README.txt
@@ -0,0 +1,13 @@
+//===----------------------------------------------------------------------===/
+//                 Kaleidoscope with Orc - Initial Version
+//===----------------------------------------------------------------------===//
+
+This version of Kaleidoscope with Orc demonstrates fully eager compilation. When
+a function definition or top-level expression is entered it is immediately
+translated (IRGen'd) to LLVM IR and added to the JIT, where it is code-gen'd to
+native code and either stored (for function definitions) or executed (for
+top-level expressions).
+
+This directory contain a Makefile that allow the code to be built in a
+standalone manner, independent of the larger LLVM build infrastructure. To build
+the program you will need to have 'clang++' and 'llvm-config' in your path.
diff --git a/examples/Kaleidoscope/Orc/initial/toy.cpp b/examples/Kaleidoscope/Orc/initial/toy.cpp
new file mode 100644
index 0000000..1b65e8c
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/initial/toy.cpp
@@ -0,0 +1,1333 @@
+#include "llvm/Analysis/Passes.h"
+#include "llvm/ExecutionEngine/Orc/CompileUtils.h"
+#include "llvm/ExecutionEngine/Orc/IRCompileLayer.h"
+#include "llvm/ExecutionEngine/Orc/LazyEmittingLayer.h"
+#include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Transforms/Scalar.h"
+#include <cctype>
+#include <iomanip>
+#include <iostream>
+#include <map>
+#include <sstream>
+#include <string>
+#include <vector>
+
+using namespace llvm;
+using namespace llvm::orc;
+
+//===----------------------------------------------------------------------===//
+// Lexer
+//===----------------------------------------------------------------------===//
+
+// The lexer returns tokens [0-255] if it is an unknown character, otherwise one
+// of these for known things.
+enum Token {
+  tok_eof = -1,
+
+  // commands
+  tok_def = -2, tok_extern = -3,
+
+  // primary
+  tok_identifier = -4, tok_number = -5,
+  
+  // control
+  tok_if = -6, tok_then = -7, tok_else = -8,
+  tok_for = -9, tok_in = -10,
+  
+  // operators
+  tok_binary = -11, tok_unary = -12,
+  
+  // var definition
+  tok_var = -13
+};
+
+static std::string IdentifierStr;  // Filled in if tok_identifier
+static double NumVal;              // Filled in if tok_number
+
+/// gettok - Return the next token from standard input.
+static int gettok() {
+  static int LastChar = ' ';
+
+  // Skip any whitespace.
+  while (isspace(LastChar))
+    LastChar = getchar();
+
+  if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
+    IdentifierStr = LastChar;
+    while (isalnum((LastChar = getchar())))
+      IdentifierStr += LastChar;
+
+    if (IdentifierStr == "def") return tok_def;
+    if (IdentifierStr == "extern") return tok_extern;
+    if (IdentifierStr == "if") return tok_if;
+    if (IdentifierStr == "then") return tok_then;
+    if (IdentifierStr == "else") return tok_else;
+    if (IdentifierStr == "for") return tok_for;
+    if (IdentifierStr == "in") return tok_in;
+    if (IdentifierStr == "binary") return tok_binary;
+    if (IdentifierStr == "unary") return tok_unary;
+    if (IdentifierStr == "var") return tok_var;
+    return tok_identifier;
+  }
+
+  if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
+    std::string NumStr;
+    do {
+      NumStr += LastChar;
+      LastChar = getchar();
+    } while (isdigit(LastChar) || LastChar == '.');
+
+    NumVal = strtod(NumStr.c_str(), 0);
+    return tok_number;
+  }
+
+  if (LastChar == '#') {
+    // Comment until end of line.
+    do LastChar = getchar();
+    while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
+    
+    if (LastChar != EOF)
+      return gettok();
+  }
+  
+  // Check for end of file.  Don't eat the EOF.
+  if (LastChar == EOF)
+    return tok_eof;
+
+  // Otherwise, just return the character as its ascii value.
+  int ThisChar = LastChar;
+  LastChar = getchar();
+  return ThisChar;
+}
+
+//===----------------------------------------------------------------------===//
+// Abstract Syntax Tree (aka Parse Tree)
+//===----------------------------------------------------------------------===//
+
+class IRGenContext;
+
+/// ExprAST - Base class for all expression nodes.
+struct ExprAST {
+  virtual ~ExprAST() {}
+  virtual Value *IRGen(IRGenContext &C) const = 0;
+};
+
+/// NumberExprAST - Expression class for numeric literals like "1.0".
+struct NumberExprAST : public ExprAST {
+  NumberExprAST(double Val) : Val(Val) {}
+  Value *IRGen(IRGenContext &C) const override;
+
+  double Val;
+};
+
+/// VariableExprAST - Expression class for referencing a variable, like "a".
+struct VariableExprAST : public ExprAST {
+  VariableExprAST(std::string Name) : Name(std::move(Name)) {}
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::string Name;
+};
+
+/// UnaryExprAST - Expression class for a unary operator.
+struct UnaryExprAST : public ExprAST {
+  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand) 
+    : Opcode(std::move(Opcode)), Operand(std::move(Operand)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  char Opcode;
+  std::unique_ptr<ExprAST> Operand;
+};
+
+/// BinaryExprAST - Expression class for a binary operator.
+struct BinaryExprAST : public ExprAST {
+  BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
+                std::unique_ptr<ExprAST> RHS) 
+    : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  char Op;
+  std::unique_ptr<ExprAST> LHS, RHS;
+};
+
+/// CallExprAST - Expression class for function calls.
+struct CallExprAST : public ExprAST {
+  CallExprAST(std::string CalleeName,
+              std::vector<std::unique_ptr<ExprAST>> Args)
+    : CalleeName(std::move(CalleeName)), Args(std::move(Args)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::string CalleeName;
+  std::vector<std::unique_ptr<ExprAST>> Args;
+};
+
+/// IfExprAST - Expression class for if/then/else.
+struct IfExprAST : public ExprAST {
+  IfExprAST(std::unique_ptr<ExprAST> Cond, std::unique_ptr<ExprAST> Then,
+            std::unique_ptr<ExprAST> Else)
+    : Cond(std::move(Cond)), Then(std::move(Then)), Else(std::move(Else)) {}
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::unique_ptr<ExprAST> Cond, Then, Else;
+};
+
+/// ForExprAST - Expression class for for/in.
+struct ForExprAST : public ExprAST {
+  ForExprAST(std::string VarName, std::unique_ptr<ExprAST> Start,
+             std::unique_ptr<ExprAST> End, std::unique_ptr<ExprAST> Step,
+             std::unique_ptr<ExprAST> Body)
+    : VarName(std::move(VarName)), Start(std::move(Start)), End(std::move(End)),
+      Step(std::move(Step)), Body(std::move(Body)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::string VarName;
+  std::unique_ptr<ExprAST> Start, End, Step, Body;
+};
+
+/// VarExprAST - Expression class for var/in
+struct VarExprAST : public ExprAST {
+  typedef std::pair<std::string, std::unique_ptr<ExprAST>> Binding;
+  typedef std::vector<Binding> BindingList;
+
+  VarExprAST(BindingList VarBindings, std::unique_ptr<ExprAST> Body)
+    : VarBindings(std::move(VarBindings)), Body(std::move(Body)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  BindingList VarBindings;
+  std::unique_ptr<ExprAST> Body;
+};
+
+/// PrototypeAST - This class represents the "prototype" for a function,
+/// which captures its argument names as well as if it is an operator.
+struct PrototypeAST {
+  PrototypeAST(std::string Name, std::vector<std::string> Args,
+               bool IsOperator = false, unsigned Precedence = 0)
+    : Name(std::move(Name)), Args(std::move(Args)), IsOperator(IsOperator),
+      Precedence(Precedence) {}
+
+  Function *IRGen(IRGenContext &C) const;
+  void CreateArgumentAllocas(Function *F, IRGenContext &C);
+
+  bool isUnaryOp() const { return IsOperator && Args.size() == 1; }
+  bool isBinaryOp() const { return IsOperator && Args.size() == 2; }
+  
+  char getOperatorName() const {
+    assert(isUnaryOp() || isBinaryOp());
+    return Name[Name.size()-1];
+  }
+
+  std::string Name;
+  std::vector<std::string> Args;
+  bool IsOperator;
+  unsigned Precedence;  // Precedence if a binary op.
+};
+
+/// FunctionAST - This class represents a function definition itself.
+struct FunctionAST {
+  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
+              std::unique_ptr<ExprAST> Body)
+    : Proto(std::move(Proto)), Body(std::move(Body)) {}
+
+  Function *IRGen(IRGenContext &C) const;
+
+  std::unique_ptr<PrototypeAST> Proto;
+  std::unique_ptr<ExprAST> Body;
+};
+
+//===----------------------------------------------------------------------===//
+// Parser
+//===----------------------------------------------------------------------===//
+
+/// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
+/// token the parser is looking at.  getNextToken reads another token from the
+/// lexer and updates CurTok with its results.
+static int CurTok;
+static int getNextToken() {
+  return CurTok = gettok();
+}
+
+/// BinopPrecedence - This holds the precedence for each binary operator that is
+/// defined.
+static std::map<char, int> BinopPrecedence;
+
+/// GetTokPrecedence - Get the precedence of the pending binary operator token.
+static int GetTokPrecedence() {
+  if (!isascii(CurTok))
+    return -1;
+  
+  // Make sure it's a declared binop.
+  int TokPrec = BinopPrecedence[CurTok];
+  if (TokPrec <= 0) return -1;
+  return TokPrec;
+}
+
+template <typename T>
+std::unique_ptr<T> ErrorU(const std::string &Str) {
+  std::cerr << "Error: " << Str << "\n";
+  return nullptr;
+}
+
+template <typename T>
+T* ErrorP(const std::string &Str) {
+  std::cerr << "Error: " << Str << "\n";
+  return nullptr;
+}
+
+static std::unique_ptr<ExprAST> ParseExpression();
+
+/// identifierexpr
+///   ::= identifier
+///   ::= identifier '(' expression* ')'
+static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
+  std::string IdName = IdentifierStr;
+  
+  getNextToken();  // eat identifier.
+  
+  if (CurTok != '(') // Simple variable ref.
+    return llvm::make_unique<VariableExprAST>(IdName);
+  
+  // Call.
+  getNextToken();  // eat (
+  std::vector<std::unique_ptr<ExprAST>> Args;
+  if (CurTok != ')') {
+    while (1) {
+      auto Arg = ParseExpression();
+      if (!Arg) return nullptr;
+      Args.push_back(std::move(Arg));
+
+      if (CurTok == ')') break;
+
+      if (CurTok != ',')
+        return ErrorU<CallExprAST>("Expected ')' or ',' in argument list");
+      getNextToken();
+    }
+  }
+
+  // Eat the ')'.
+  getNextToken();
+  
+  return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
+}
+
+/// numberexpr ::= number
+static std::unique_ptr<NumberExprAST> ParseNumberExpr() {
+  auto Result = llvm::make_unique<NumberExprAST>(NumVal);
+  getNextToken(); // consume the number
+  return Result;
+}
+
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+  getNextToken();  // eat (.
+  auto V = ParseExpression();
+  if (!V)
+    return nullptr;
+  
+  if (CurTok != ')')
+    return ErrorU<ExprAST>("expected ')'");
+  getNextToken();  // eat ).
+  return V;
+}
+
+/// ifexpr ::= 'if' expression 'then' expression 'else' expression
+static std::unique_ptr<ExprAST> ParseIfExpr() {
+  getNextToken();  // eat the if.
+  
+  // condition.
+  auto Cond = ParseExpression();
+  if (!Cond)
+    return nullptr;
+  
+  if (CurTok != tok_then)
+    return ErrorU<ExprAST>("expected then");
+  getNextToken();  // eat the then
+  
+  auto Then = ParseExpression();
+  if (!Then)
+    return nullptr;
+  
+  if (CurTok != tok_else)
+    return ErrorU<ExprAST>("expected else");
+  
+  getNextToken();
+  
+  auto Else = ParseExpression();
+  if (!Else)
+    return nullptr;
+  
+  return llvm::make_unique<IfExprAST>(std::move(Cond), std::move(Then),
+                                      std::move(Else));
+}
+
+/// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
+static std::unique_ptr<ForExprAST> ParseForExpr() {
+  getNextToken();  // eat the for.
+
+  if (CurTok != tok_identifier)
+    return ErrorU<ForExprAST>("expected identifier after for");
+  
+  std::string IdName = IdentifierStr;
+  getNextToken();  // eat identifier.
+  
+  if (CurTok != '=')
+    return ErrorU<ForExprAST>("expected '=' after for");
+  getNextToken();  // eat '='.
+  
+  
+  auto Start = ParseExpression();
+  if (!Start)
+    return nullptr;
+  if (CurTok != ',')
+    return ErrorU<ForExprAST>("expected ',' after for start value");
+  getNextToken();
+  
+  auto End = ParseExpression();
+  if (!End)
+    return nullptr;
+  
+  // The step value is optional.
+  std::unique_ptr<ExprAST> Step;
+  if (CurTok == ',') {
+    getNextToken();
+    Step = ParseExpression();
+    if (!Step)
+      return nullptr;
+  }
+  
+  if (CurTok != tok_in)
+    return ErrorU<ForExprAST>("expected 'in' after for");
+  getNextToken();  // eat 'in'.
+  
+  auto Body = ParseExpression();
+  if (Body)
+    return nullptr;
+
+  return llvm::make_unique<ForExprAST>(IdName, std::move(Start), std::move(End),
+                                       std::move(Step), std::move(Body));
+}
+
+/// varexpr ::= 'var' identifier ('=' expression)? 
+//                    (',' identifier ('=' expression)?)* 'in' expression
+static std::unique_ptr<VarExprAST> ParseVarExpr() {
+  getNextToken();  // eat the var.
+
+  VarExprAST::BindingList VarBindings;
+
+  // At least one variable name is required.
+  if (CurTok != tok_identifier)
+    return ErrorU<VarExprAST>("expected identifier after var");
+  
+  while (1) {
+    std::string Name = IdentifierStr;
+    getNextToken();  // eat identifier.
+
+    // Read the optional initializer.
+    std::unique_ptr<ExprAST> Init;
+    if (CurTok == '=') {
+      getNextToken(); // eat the '='.
+      
+      Init = ParseExpression();
+      if (!Init)
+        return nullptr;
+    }
+    
+    VarBindings.push_back(VarExprAST::Binding(Name, std::move(Init)));
+    
+    // End of var list, exit loop.
+    if (CurTok != ',') break;
+    getNextToken(); // eat the ','.
+    
+    if (CurTok != tok_identifier)
+      return ErrorU<VarExprAST>("expected identifier list after var");
+  }
+  
+  // At this point, we have to have 'in'.
+  if (CurTok != tok_in)
+    return ErrorU<VarExprAST>("expected 'in' keyword after 'var'");
+  getNextToken();  // eat 'in'.
+  
+  auto Body = ParseExpression();
+  if (!Body)
+    return nullptr;
+  
+  return llvm::make_unique<VarExprAST>(std::move(VarBindings), std::move(Body));
+}
+
+/// primary
+///   ::= identifierexpr
+///   ::= numberexpr
+///   ::= parenexpr
+///   ::= ifexpr
+///   ::= forexpr
+///   ::= varexpr
+static std::unique_ptr<ExprAST> ParsePrimary() {
+  switch (CurTok) {
+  default: return ErrorU<ExprAST>("unknown token when expecting an expression");
+  case tok_identifier: return ParseIdentifierExpr();
+  case tok_number:     return ParseNumberExpr();
+  case '(':            return ParseParenExpr();
+  case tok_if:         return ParseIfExpr();
+  case tok_for:        return ParseForExpr();
+  case tok_var:        return ParseVarExpr();
+  }
+}
+
+/// unary
+///   ::= primary
+///   ::= '!' unary
+static std::unique_ptr<ExprAST> ParseUnary() {
+  // If the current token is not an operator, it must be a primary expr.
+  if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
+    return ParsePrimary();
+  
+  // If this is a unary operator, read it.
+  int Opc = CurTok;
+  getNextToken();
+  if (auto Operand = ParseUnary())
+    return llvm::make_unique<UnaryExprAST>(Opc, std::move(Operand));
+  return nullptr;
+}
+
+/// binoprhs
+///   ::= ('+' unary)*
+static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
+                                              std::unique_ptr<ExprAST> LHS) {
+  // If this is a binop, find its precedence.
+  while (1) {
+    int TokPrec = GetTokPrecedence();
+    
+    // If this is a binop that binds at least as tightly as the current binop,
+    // consume it, otherwise we are done.
+    if (TokPrec < ExprPrec)
+      return LHS;
+    
+    // Okay, we know this is a binop.
+    int BinOp = CurTok;
+    getNextToken();  // eat binop
+    
+    // Parse the unary expression after the binary operator.
+    auto RHS = ParseUnary();
+    if (!RHS)
+      return nullptr;
+    
+    // If BinOp binds less tightly with RHS than the operator after RHS, let
+    // the pending operator take RHS as its LHS.
+    int NextPrec = GetTokPrecedence();
+    if (TokPrec < NextPrec) {
+      RHS = ParseBinOpRHS(TokPrec+1, std::move(RHS));
+      if (!RHS)
+        return nullptr;
+    }
+    
+    // Merge LHS/RHS.
+    LHS = llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
+  }
+}
+
+/// expression
+///   ::= unary binoprhs
+///
+static std::unique_ptr<ExprAST> ParseExpression() {
+  auto LHS = ParseUnary();
+  if (!LHS)
+    return nullptr;
+  
+  return ParseBinOpRHS(0, std::move(LHS));
+}
+
+/// prototype
+///   ::= id '(' id* ')'
+///   ::= binary LETTER number? (id, id)
+///   ::= unary LETTER (id)
+static std::unique_ptr<PrototypeAST> ParsePrototype() {
+  std::string FnName;
+  
+  unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
+  unsigned BinaryPrecedence = 30;
+  
+  switch (CurTok) {
+  default:
+    return ErrorU<PrototypeAST>("Expected function name in prototype");
+  case tok_identifier:
+    FnName = IdentifierStr;
+    Kind = 0;
+    getNextToken();
+    break;
+  case tok_unary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorU<PrototypeAST>("Expected unary operator");
+    FnName = "unary";
+    FnName += (char)CurTok;
+    Kind = 1;
+    getNextToken();
+    break;
+  case tok_binary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorU<PrototypeAST>("Expected binary operator");
+    FnName = "binary";
+    FnName += (char)CurTok;
+    Kind = 2;
+    getNextToken();
+    
+    // Read the precedence if present.
+    if (CurTok == tok_number) {
+      if (NumVal < 1 || NumVal > 100)
+        return ErrorU<PrototypeAST>("Invalid precedecnce: must be 1..100");
+      BinaryPrecedence = (unsigned)NumVal;
+      getNextToken();
+    }
+    break;
+  }
+  
+  if (CurTok != '(')
+    return ErrorU<PrototypeAST>("Expected '(' in prototype");
+  
+  std::vector<std::string> ArgNames;
+  while (getNextToken() == tok_identifier)
+    ArgNames.push_back(IdentifierStr);
+  if (CurTok != ')')
+    return ErrorU<PrototypeAST>("Expected ')' in prototype");
+  
+  // success.
+  getNextToken();  // eat ')'.
+  
+  // Verify right number of names for operator.
+  if (Kind && ArgNames.size() != Kind)
+    return ErrorU<PrototypeAST>("Invalid number of operands for operator");
+  
+  return llvm::make_unique<PrototypeAST>(FnName, std::move(ArgNames), Kind != 0,
+                                         BinaryPrecedence);
+}
+
+/// definition ::= 'def' prototype expression
+static std::unique_ptr<FunctionAST> ParseDefinition() {
+  getNextToken();  // eat def.
+  auto Proto = ParsePrototype();
+  if (!Proto)
+    return nullptr;
+
+  if (auto Body = ParseExpression())
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(Body));
+  return nullptr;
+}
+
+/// toplevelexpr ::= expression
+static std::unique_ptr<FunctionAST> ParseTopLevelExpr() {
+  if (auto E = ParseExpression()) {
+    // Make an anonymous proto.
+    auto Proto =
+      llvm::make_unique<PrototypeAST>("__anon_expr", std::vector<std::string>());
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
+  }
+  return nullptr;
+}
+
+/// external ::= 'extern' prototype
+static std::unique_ptr<PrototypeAST> ParseExtern() {
+  getNextToken();  // eat extern.
+  return ParsePrototype();
+}
+
+//===----------------------------------------------------------------------===//
+// Code Generation
+//===----------------------------------------------------------------------===//
+
+// FIXME: Obviously we can do better than this
+std::string GenerateUniqueName(const std::string &Root) {
+  static int i = 0;
+  std::ostringstream NameStream;
+  NameStream << Root << ++i;
+  return NameStream.str();
+}
+
+std::string MakeLegalFunctionName(std::string Name)
+{
+  std::string NewName;
+  assert(!Name.empty() && "Base name must not be empty");
+
+  // Start with what we have
+  NewName = Name;
+
+  // Look for a numberic first character
+  if (NewName.find_first_of("0123456789") == 0) {
+    NewName.insert(0, 1, 'n');
+  }
+
+  // Replace illegal characters with their ASCII equivalent
+  std::string legal_elements = "_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+  size_t pos;
+  while ((pos = NewName.find_first_not_of(legal_elements)) != std::string::npos) {
+    std::ostringstream NumStream;
+    NumStream << (int)NewName.at(pos);
+    NewName = NewName.replace(pos, 1, NumStream.str());
+  }
+
+  return NewName;
+}
+
+class SessionContext {
+public:
+  SessionContext(LLVMContext &C)
+    : Context(C), TM(EngineBuilder().selectTarget()) {}
+  LLVMContext& getLLVMContext() const { return Context; }
+  TargetMachine& getTarget() { return *TM; }
+  void addPrototypeAST(std::unique_ptr<PrototypeAST> P);
+  PrototypeAST* getPrototypeAST(const std::string &Name);
+private:
+  typedef std::map<std::string, std::unique_ptr<PrototypeAST>> PrototypeMap;
+  
+  LLVMContext &Context;
+  std::unique_ptr<TargetMachine> TM;
+      
+  PrototypeMap Prototypes;
+};
+
+void SessionContext::addPrototypeAST(std::unique_ptr<PrototypeAST> P) {
+  Prototypes[P->Name] = std::move(P);
+}
+
+PrototypeAST* SessionContext::getPrototypeAST(const std::string &Name) {
+  PrototypeMap::iterator I = Prototypes.find(Name);
+  if (I != Prototypes.end())
+    return I->second.get();
+  return nullptr;
+}
+
+class IRGenContext {
+public:
+
+  IRGenContext(SessionContext &S)
+    : Session(S),
+      M(new Module(GenerateUniqueName("jit_module_"),
+                   Session.getLLVMContext())),
+      Builder(Session.getLLVMContext()) {
+    M->setDataLayout(Session.getTarget().getDataLayout());
+  }
+
+  SessionContext& getSession() { return Session; }
+  Module& getM() const { return *M; }
+  std::unique_ptr<Module> takeM() { return std::move(M); }
+  IRBuilder<>& getBuilder() { return Builder; }
+  LLVMContext& getLLVMContext() { return Session.getLLVMContext(); }
+  Function* getPrototype(const std::string &Name);
+
+  std::map<std::string, AllocaInst*> NamedValues;
+private:
+  SessionContext &Session;
+  std::unique_ptr<Module> M;
+  IRBuilder<> Builder;
+};
+
+Function* IRGenContext::getPrototype(const std::string &Name) {
+  if (Function *ExistingProto = M->getFunction(Name))
+    return ExistingProto;
+  if (PrototypeAST *ProtoAST = Session.getPrototypeAST(Name))
+    return ProtoAST->IRGen(*this);
+  return nullptr;
+}
+
+/// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
+/// the function.  This is used for mutable variables etc.
+static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
+                                          const std::string &VarName) {
+  IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
+                 TheFunction->getEntryBlock().begin());
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+                           VarName.c_str());
+}
+
+Value *NumberExprAST::IRGen(IRGenContext &C) const {
+  return ConstantFP::get(C.getLLVMContext(), APFloat(Val));
+}
+
+Value *VariableExprAST::IRGen(IRGenContext &C) const {
+  // Look this variable up in the function.
+  Value *V = C.NamedValues[Name];
+
+  if (V == 0)
+    return ErrorP<Value>("Unknown variable name '" + Name + "'");
+
+  // Load the value.
+  return C.getBuilder().CreateLoad(V, Name.c_str());
+}
+
+Value *UnaryExprAST::IRGen(IRGenContext &C) const {
+  if (Value *OperandV = Operand->IRGen(C)) {
+    std::string FnName = MakeLegalFunctionName(std::string("unary")+Opcode);
+    if (Function *F = C.getPrototype(FnName))
+      return C.getBuilder().CreateCall(F, OperandV, "unop");
+    return ErrorP<Value>("Unknown unary operator");
+  }
+
+  // Could not codegen operand - return null.
+  return nullptr;
+}
+
+Value *BinaryExprAST::IRGen(IRGenContext &C) const {
+  // Special case '=' because we don't want to emit the LHS as an expression.
+  if (Op == '=') {
+    // Assignment requires the LHS to be an identifier.
+    auto LHSVar = static_cast<VariableExprAST&>(*LHS);
+    // Codegen the RHS.
+    Value *Val = RHS->IRGen(C);
+    if (!Val) return nullptr;
+
+    // Look up the name.
+    if (auto Variable = C.NamedValues[LHSVar.Name]) {
+      C.getBuilder().CreateStore(Val, Variable);
+      return Val;
+    }
+    return ErrorP<Value>("Unknown variable name");
+  }
+  
+  Value *L = LHS->IRGen(C);
+  Value *R = RHS->IRGen(C);
+  if (!L || !R) return nullptr;
+  
+  switch (Op) {
+  case '+': return C.getBuilder().CreateFAdd(L, R, "addtmp");
+  case '-': return C.getBuilder().CreateFSub(L, R, "subtmp");
+  case '*': return C.getBuilder().CreateFMul(L, R, "multmp");
+  case '/': return C.getBuilder().CreateFDiv(L, R, "divtmp");
+  case '<':
+    L = C.getBuilder().CreateFCmpULT(L, R, "cmptmp");
+    // Convert bool 0/1 to double 0.0 or 1.0
+    return C.getBuilder().CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
+                                "booltmp");
+  default: break;
+  }
+  
+  // If it wasn't a builtin binary operator, it must be a user defined one. Emit
+  // a call to it.
+  std::string FnName = MakeLegalFunctionName(std::string("binary")+Op);
+  if (Function *F = C.getPrototype(FnName)) {
+    Value *Ops[] = { L, R };
+    return C.getBuilder().CreateCall(F, Ops, "binop");
+  }
+   
+  return ErrorP<Value>("Unknown binary operator");
+}
+
+Value *CallExprAST::IRGen(IRGenContext &C) const {
+  // Look up the name in the global module table.
+  if (auto CalleeF = C.getPrototype(CalleeName)) {
+    // If argument mismatch error.
+    if (CalleeF->arg_size() != Args.size())
+      return ErrorP<Value>("Incorrect # arguments passed");
+
+    std::vector<Value*> ArgsV;
+    for (unsigned i = 0, e = Args.size(); i != e; ++i) {
+      ArgsV.push_back(Args[i]->IRGen(C));
+      if (!ArgsV.back()) return nullptr;
+    }
+    
+    return C.getBuilder().CreateCall(CalleeF, ArgsV, "calltmp");
+  }
+
+  return ErrorP<Value>("Unknown function referenced");
+}
+
+Value *IfExprAST::IRGen(IRGenContext &C) const {
+  Value *CondV = Cond->IRGen(C);
+  if (!CondV) return nullptr;
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  ConstantFP *FPZero = 
+    ConstantFP::get(C.getLLVMContext(), APFloat(0.0));
+  CondV = C.getBuilder().CreateFCmpONE(CondV, FPZero, "ifcond");
+  
+  Function *TheFunction = C.getBuilder().GetInsertBlock()->getParent();
+  
+  // Create blocks for the then and else cases.  Insert the 'then' block at the
+  // end of the function.
+  BasicBlock *ThenBB = BasicBlock::Create(C.getLLVMContext(), "then", TheFunction);
+  BasicBlock *ElseBB = BasicBlock::Create(C.getLLVMContext(), "else");
+  BasicBlock *MergeBB = BasicBlock::Create(C.getLLVMContext(), "ifcont");
+  
+  C.getBuilder().CreateCondBr(CondV, ThenBB, ElseBB);
+  
+  // Emit then value.
+  C.getBuilder().SetInsertPoint(ThenBB);
+  
+  Value *ThenV = Then->IRGen(C);
+  if (!ThenV) return nullptr;
+  
+  C.getBuilder().CreateBr(MergeBB);
+  // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
+  ThenBB = C.getBuilder().GetInsertBlock();
+  
+  // Emit else block.
+  TheFunction->getBasicBlockList().push_back(ElseBB);
+  C.getBuilder().SetInsertPoint(ElseBB);
+  
+  Value *ElseV = Else->IRGen(C);
+  if (!ElseV) return nullptr;
+  
+  C.getBuilder().CreateBr(MergeBB);
+  // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
+  ElseBB = C.getBuilder().GetInsertBlock();
+  
+  // Emit merge block.
+  TheFunction->getBasicBlockList().push_back(MergeBB);
+  C.getBuilder().SetInsertPoint(MergeBB);
+  PHINode *PN = C.getBuilder().CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
+                                  "iftmp");
+  
+  PN->addIncoming(ThenV, ThenBB);
+  PN->addIncoming(ElseV, ElseBB);
+  return PN;
+}
+
+Value *ForExprAST::IRGen(IRGenContext &C) const {
+  // Output this as:
+  //   var = alloca double
+  //   ...
+  //   start = startexpr
+  //   store start -> var
+  //   goto loop
+  // loop: 
+  //   ...
+  //   bodyexpr
+  //   ...
+  // loopend:
+  //   step = stepexpr
+  //   endcond = endexpr
+  //
+  //   curvar = load var
+  //   nextvar = curvar + step
+  //   store nextvar -> var
+  //   br endcond, loop, endloop
+  // outloop:
+  
+  Function *TheFunction = C.getBuilder().GetInsertBlock()->getParent();
+
+  // Create an alloca for the variable in the entry block.
+  AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+  
+  // Emit the start code first, without 'variable' in scope.
+  Value *StartVal = Start->IRGen(C);
+  if (!StartVal) return nullptr;
+  
+  // Store the value into the alloca.
+  C.getBuilder().CreateStore(StartVal, Alloca);
+  
+  // Make the new basic block for the loop header, inserting after current
+  // block.
+  BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
+  
+  // Insert an explicit fall through from the current block to the LoopBB.
+  C.getBuilder().CreateBr(LoopBB);
+
+  // Start insertion in LoopBB.
+  C.getBuilder().SetInsertPoint(LoopBB);
+  
+  // Within the loop, the variable is defined equal to the PHI node.  If it
+  // shadows an existing variable, we have to restore it, so save it now.
+  AllocaInst *OldVal = C.NamedValues[VarName];
+  C.NamedValues[VarName] = Alloca;
+  
+  // Emit the body of the loop.  This, like any other expr, can change the
+  // current BB.  Note that we ignore the value computed by the body, but don't
+  // allow an error.
+  if (!Body->IRGen(C))
+    return nullptr;
+  
+  // Emit the step value.
+  Value *StepVal;
+  if (Step) {
+    StepVal = Step->IRGen(C);
+    if (!StepVal) return nullptr;
+  } else {
+    // If not specified, use 1.0.
+    StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
+  }
+  
+  // Compute the end condition.
+  Value *EndCond = End->IRGen(C);
+  if (EndCond == 0) return EndCond;
+  
+  // Reload, increment, and restore the alloca.  This handles the case where
+  // the body of the loop mutates the variable.
+  Value *CurVar = C.getBuilder().CreateLoad(Alloca, VarName.c_str());
+  Value *NextVar = C.getBuilder().CreateFAdd(CurVar, StepVal, "nextvar");
+  C.getBuilder().CreateStore(NextVar, Alloca);
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  EndCond = C.getBuilder().CreateFCmpONE(EndCond, 
+                              ConstantFP::get(getGlobalContext(), APFloat(0.0)),
+                                  "loopcond");
+  
+  // Create the "after loop" block and insert it.
+  BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
+  
+  // Insert the conditional branch into the end of LoopEndBB.
+  C.getBuilder().CreateCondBr(EndCond, LoopBB, AfterBB);
+  
+  // Any new code will be inserted in AfterBB.
+  C.getBuilder().SetInsertPoint(AfterBB);
+  
+  // Restore the unshadowed variable.
+  if (OldVal)
+    C.NamedValues[VarName] = OldVal;
+  else
+    C.NamedValues.erase(VarName);
+
+  
+  // for expr always returns 0.0.
+  return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
+}
+
+Value *VarExprAST::IRGen(IRGenContext &C) const {
+  std::vector<AllocaInst *> OldBindings;
+  
+  Function *TheFunction = C.getBuilder().GetInsertBlock()->getParent();
+
+  // Register all variables and emit their initializer.
+  for (unsigned i = 0, e = VarBindings.size(); i != e; ++i) {
+    auto &VarName = VarBindings[i].first;
+    auto &Init = VarBindings[i].second;
+    
+    // Emit the initializer before adding the variable to scope, this prevents
+    // the initializer from referencing the variable itself, and permits stuff
+    // like this:
+    //  var a = 1 in
+    //    var a = a in ...   # refers to outer 'a'.
+    Value *InitVal;
+    if (Init) {
+      InitVal = Init->IRGen(C);
+      if (!InitVal) return nullptr;
+    } else // If not specified, use 0.0.
+      InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
+    
+    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+    C.getBuilder().CreateStore(InitVal, Alloca);
+
+    // Remember the old variable binding so that we can restore the binding when
+    // we unrecurse.
+    OldBindings.push_back(C.NamedValues[VarName]);
+    
+    // Remember this binding.
+    C.NamedValues[VarName] = Alloca;
+  }
+  
+  // Codegen the body, now that all vars are in scope.
+  Value *BodyVal = Body->IRGen(C);
+  if (!BodyVal) return nullptr;
+  
+  // Pop all our variables from scope.
+  for (unsigned i = 0, e = VarBindings.size(); i != e; ++i)
+    C.NamedValues[VarBindings[i].first] = OldBindings[i];
+
+  // Return the body computation.
+  return BodyVal;
+}
+
+Function *PrototypeAST::IRGen(IRGenContext &C) const {
+  std::string FnName = MakeLegalFunctionName(Name);
+
+  // Make the function type:  double(double,double) etc.
+  std::vector<Type*> Doubles(Args.size(), 
+                             Type::getDoubleTy(getGlobalContext()));
+  FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
+                                       Doubles, false);
+  Function *F = Function::Create(FT, Function::ExternalLinkage, FnName,
+                                 &C.getM());
+
+  // If F conflicted, there was already something named 'FnName'.  If it has a
+  // body, don't allow redefinition or reextern.
+  if (F->getName() != FnName) {
+    // Delete the one we just made and get the existing one.
+    F->eraseFromParent();
+    F = C.getM().getFunction(Name);
+    
+    // If F already has a body, reject this.
+    if (!F->empty()) {
+      ErrorP<Function>("redefinition of function");
+      return nullptr;
+    }
+    
+    // If F took a different number of args, reject.
+    if (F->arg_size() != Args.size()) {
+      ErrorP<Function>("redefinition of function with different # args");
+      return nullptr;
+    }
+  }
+  
+  // Set names for all arguments.
+  unsigned Idx = 0;
+  for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
+       ++AI, ++Idx)
+    AI->setName(Args[Idx]);
+    
+  return F;
+}
+
+/// CreateArgumentAllocas - Create an alloca for each argument and register the
+/// argument in the symbol table so that references to it will succeed.
+void PrototypeAST::CreateArgumentAllocas(Function *F, IRGenContext &C) {
+  Function::arg_iterator AI = F->arg_begin();
+  for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
+    // Create an alloca for this variable.
+    AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
+
+    // Store the initial value into the alloca.
+    C.getBuilder().CreateStore(AI, Alloca);
+
+    // Add arguments to variable symbol table.
+    C.NamedValues[Args[Idx]] = Alloca;
+  }
+}
+
+Function *FunctionAST::IRGen(IRGenContext &C) const {
+  C.NamedValues.clear();
+  
+  Function *TheFunction = Proto->IRGen(C);
+  if (!TheFunction)
+    return nullptr;
+  
+  // If this is an operator, install it.
+  if (Proto->isBinaryOp())
+    BinopPrecedence[Proto->getOperatorName()] = Proto->Precedence;
+  
+  // Create a new basic block to start insertion into.
+  BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
+  C.getBuilder().SetInsertPoint(BB);
+  
+  // Add all arguments to the symbol table and create their allocas.
+  Proto->CreateArgumentAllocas(TheFunction, C);
+
+  if (Value *RetVal = Body->IRGen(C)) {
+    // Finish off the function.
+    C.getBuilder().CreateRet(RetVal);
+
+    // Validate the generated code, checking for consistency.
+    verifyFunction(*TheFunction);
+
+    return TheFunction;
+  }
+  
+  // Error reading body, remove function.
+  TheFunction->eraseFromParent();
+
+  if (Proto->isBinaryOp())
+    BinopPrecedence.erase(Proto->getOperatorName());
+  return nullptr;
+}
+
+//===----------------------------------------------------------------------===//
+// Top-Level parsing and JIT Driver
+//===----------------------------------------------------------------------===//
+
+static std::unique_ptr<llvm::Module> IRGen(SessionContext &S,
+                                           const FunctionAST &F) {
+  IRGenContext C(S);
+  auto LF = F.IRGen(C);
+  if (!LF)
+    return nullptr;
+#ifndef MINIMAL_STDERR_OUTPUT
+  fprintf(stderr, "Read function definition:");
+  LF->dump();
+#endif
+  return C.takeM();
+}
+
+template <typename T>
+static std::vector<T> singletonSet(T t) {
+  std::vector<T> Vec;
+  Vec.push_back(std::move(t));
+  return Vec;
+}
+
+class KaleidoscopeJIT {
+public:
+  typedef ObjectLinkingLayer<> ObjLayerT;
+  typedef IRCompileLayer<ObjLayerT> CompileLayerT;
+  typedef CompileLayerT::ModuleSetHandleT ModuleHandleT;
+
+  KaleidoscopeJIT(SessionContext &Session)
+    : Mang(Session.getTarget().getDataLayout()),
+      CompileLayer(ObjectLayer, SimpleCompiler(Session.getTarget())) {}
+
+  std::string mangle(const std::string &Name) {
+    std::string MangledName;
+    {
+      raw_string_ostream MangledNameStream(MangledName);
+      Mang.getNameWithPrefix(MangledNameStream, Name);
+    }
+    return MangledName;
+  }
+
+  ModuleHandleT addModule(std::unique_ptr<Module> M) {
+    // We need a memory manager to allocate memory and resolve symbols for this
+    // new module. Create one that resolves symbols by looking back into the
+    // JIT.
+    auto MM = createLookasideRTDyldMM<SectionMemoryManager>(
+                [&](const std::string &Name) {
+                  return findSymbol(Name).getAddress();
+                },
+                [](const std::string &S) { return 0; } );
+
+    return CompileLayer.addModuleSet(singletonSet(std::move(M)), std::move(MM));
+  }
+
+  void removeModule(ModuleHandleT H) { CompileLayer.removeModuleSet(H); }
+
+  JITSymbol findSymbol(const std::string &Name) {
+    return CompileLayer.findSymbol(Name, true);
+  }
+
+  JITSymbol findUnmangledSymbol(const std::string Name) {
+    return findSymbol(mangle(Name));
+  }
+
+private:
+
+  Mangler Mang;
+  ObjLayerT ObjectLayer;
+  CompileLayerT CompileLayer;
+};
+
+static void HandleDefinition(SessionContext &S, KaleidoscopeJIT &J) {
+  if (auto F = ParseDefinition()) {
+    if (auto M = IRGen(S, *F)) {
+      S.addPrototypeAST(llvm::make_unique<PrototypeAST>(*F->Proto));
+      J.addModule(std::move(M));
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleExtern(SessionContext &S) {
+  if (auto P = ParseExtern())
+    S.addPrototypeAST(std::move(P));
+  else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleTopLevelExpression(SessionContext &S, KaleidoscopeJIT &J) {
+  // Evaluate a top-level expression into an anonymous function.
+  if (auto F = ParseTopLevelExpr()) {
+    IRGenContext C(S);
+    if (auto ExprFunc = F->IRGen(C)) {
+#ifndef MINIMAL_STDERR_OUTPUT
+      std::cerr << "Expression function:\n";
+      ExprFunc->dump();
+#endif
+      // Add the CodeGen'd module to the JIT. Keep a handle to it: We can remove
+      // this module as soon as we've executed Function ExprFunc.
+      auto H = J.addModule(C.takeM());
+
+      // Get the address of the JIT'd function in memory.
+      auto ExprSymbol = J.findUnmangledSymbol("__anon_expr");
+      
+      // Cast it to the right type (takes no arguments, returns a double) so we
+      // can call it as a native function.
+      double (*FP)() = (double (*)())(intptr_t)ExprSymbol.getAddress();
+#ifdef MINIMAL_STDERR_OUTPUT
+      FP();
+#else
+      std::cerr << "Evaluated to " << FP() << "\n";
+#endif
+
+      // Remove the function.
+      J.removeModule(H);
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+/// top ::= definition | external | expression | ';'
+static void MainLoop() {
+  SessionContext S(getGlobalContext());
+  KaleidoscopeJIT J(S);
+
+  while (1) {
+    switch (CurTok) {
+    case tok_eof:    return;
+    case ';':        getNextToken(); continue;  // ignore top-level semicolons.
+    case tok_def:    HandleDefinition(S, J); break;
+    case tok_extern: HandleExtern(S); break;
+    default:         HandleTopLevelExpression(S, J); break;
+    }
+#ifndef MINIMAL_STDERR_OUTPUT
+    std::cerr << "ready> ";
+#endif
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// "Library" functions that can be "extern'd" from user code.
+//===----------------------------------------------------------------------===//
+
+/// putchard - putchar that takes a double and returns 0.
+extern "C" 
+double putchard(double X) {
+  putchar((char)X);
+  return 0;
+}
+
+/// printd - printf that takes a double prints it as "%f\n", returning 0.
+extern "C" 
+double printd(double X) {
+  printf("%f", X);
+  return 0;
+}
+
+extern "C" 
+double printlf() {
+  printf("\n");
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Main driver code.
+//===----------------------------------------------------------------------===//
+
+int main() {
+  InitializeNativeTarget();
+  InitializeNativeTargetAsmPrinter();
+  InitializeNativeTargetAsmParser();
+
+  // Install standard binary operators.
+  // 1 is lowest precedence.
+  BinopPrecedence['='] = 2;
+  BinopPrecedence['<'] = 10;
+  BinopPrecedence['+'] = 20;
+  BinopPrecedence['-'] = 20;
+  BinopPrecedence['/'] = 40;
+  BinopPrecedence['*'] = 40;  // highest.
+
+  // Prime the first token.
+#ifndef MINIMAL_STDERR_OUTPUT
+  std::cerr << "ready> ";
+#endif
+  getNextToken();
+
+  std::cerr << std::fixed;
+
+  // Run the main "interpreter loop" now.
+  MainLoop();
+
+  return 0;
+}
+
diff --git a/examples/Kaleidoscope/Orc/lazy_codegen/CMakeLists.txt b/examples/Kaleidoscope/Orc/lazy_codegen/CMakeLists.txt
new file mode 100644
index 0000000..faad342
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/lazy_codegen/CMakeLists.txt
@@ -0,0 +1,12 @@
+set(LLVM_LINK_COMPONENTS
+  Core
+  ExecutionEngine
+  Object
+  RuntimeDyld
+  Support
+  native
+  )
+
+add_kaleidoscope_chapter(Kaleidoscope-Orc-lazy_codegen
+  toy.cpp
+  )
diff --git a/examples/Kaleidoscope/Orc/lazy_codegen/Makefile b/examples/Kaleidoscope/Orc/lazy_codegen/Makefile
new file mode 100644
index 0000000..5536314
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/lazy_codegen/Makefile
@@ -0,0 +1,17 @@
+UNAME := $(shell uname -s)
+
+ifeq ($(UNAME),Darwin)
+	CXX := xcrun --sdk macosx clang++
+else
+	CXX := clang++
+endif
+
+LLVM_CXXFLAGS := $(shell llvm-config --cxxflags)
+LLVM_LDFLAGS := $(shell llvm-config  --ldflags --system-libs --libs core orcjit native)
+
+toy: toy.cpp
+	$(CXX) $(LLVM_CXXFLAGS) -Wall -std=c++11 -g -O0 -rdynamic -fno-rtti -o toy toy.cpp $(LLVM_LDFLAGS)
+
+.PHONY: clean
+clean:
+	rm -f toy
diff --git a/examples/Kaleidoscope/Orc/lazy_codegen/README.txt b/examples/Kaleidoscope/Orc/lazy_codegen/README.txt
new file mode 100644
index 0000000..9d62a91
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/lazy_codegen/README.txt
@@ -0,0 +1,13 @@
+//===----------------------------------------------------------------------===/
+//                 Kaleidoscope with Orc - Initial Version
+//===----------------------------------------------------------------------===//
+
+This version of Kaleidoscope with Orc demonstrates lazy code-generation.
+Unlike the first Kaleidoscope-Orc tutorial, where code-gen was performed as soon
+as modules were added to the JIT, this tutorial adds a LazyEmittingLayer to defer
+code-generation until modules are actually referenced. All IR-generation is still
+performed up-front.
+
+This directory contain a Makefile that allow the code to be built in a
+standalone manner, independent of the larger LLVM build infrastructure. To build
+the program you will need to have 'clang++' and 'llvm-config' in your path.
diff --git a/examples/Kaleidoscope/Orc/lazy_codegen/toy.cpp b/examples/Kaleidoscope/Orc/lazy_codegen/toy.cpp
new file mode 100644
index 0000000..1ed267d
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/lazy_codegen/toy.cpp
@@ -0,0 +1,1338 @@
+#include "llvm/Analysis/Passes.h"
+#include "llvm/ExecutionEngine/Orc/CompileUtils.h"
+#include "llvm/ExecutionEngine/Orc/IRCompileLayer.h"
+#include "llvm/ExecutionEngine/Orc/LazyEmittingLayer.h"
+#include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Transforms/Scalar.h"
+#include <cctype>
+#include <iomanip>
+#include <iostream>
+#include <map>
+#include <sstream>
+#include <string>
+#include <vector>
+
+using namespace llvm;
+using namespace llvm::orc;
+
+//===----------------------------------------------------------------------===//
+// Lexer
+//===----------------------------------------------------------------------===//
+
+// The lexer returns tokens [0-255] if it is an unknown character, otherwise one
+// of these for known things.
+enum Token {
+  tok_eof = -1,
+
+  // commands
+  tok_def = -2, tok_extern = -3,
+
+  // primary
+  tok_identifier = -4, tok_number = -5,
+  
+  // control
+  tok_if = -6, tok_then = -7, tok_else = -8,
+  tok_for = -9, tok_in = -10,
+  
+  // operators
+  tok_binary = -11, tok_unary = -12,
+  
+  // var definition
+  tok_var = -13
+};
+
+static std::string IdentifierStr;  // Filled in if tok_identifier
+static double NumVal;              // Filled in if tok_number
+
+/// gettok - Return the next token from standard input.
+static int gettok() {
+  static int LastChar = ' ';
+
+  // Skip any whitespace.
+  while (isspace(LastChar))
+    LastChar = getchar();
+
+  if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
+    IdentifierStr = LastChar;
+    while (isalnum((LastChar = getchar())))
+      IdentifierStr += LastChar;
+
+    if (IdentifierStr == "def") return tok_def;
+    if (IdentifierStr == "extern") return tok_extern;
+    if (IdentifierStr == "if") return tok_if;
+    if (IdentifierStr == "then") return tok_then;
+    if (IdentifierStr == "else") return tok_else;
+    if (IdentifierStr == "for") return tok_for;
+    if (IdentifierStr == "in") return tok_in;
+    if (IdentifierStr == "binary") return tok_binary;
+    if (IdentifierStr == "unary") return tok_unary;
+    if (IdentifierStr == "var") return tok_var;
+    return tok_identifier;
+  }
+
+  if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
+    std::string NumStr;
+    do {
+      NumStr += LastChar;
+      LastChar = getchar();
+    } while (isdigit(LastChar) || LastChar == '.');
+
+    NumVal = strtod(NumStr.c_str(), 0);
+    return tok_number;
+  }
+
+  if (LastChar == '#') {
+    // Comment until end of line.
+    do LastChar = getchar();
+    while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
+    
+    if (LastChar != EOF)
+      return gettok();
+  }
+  
+  // Check for end of file.  Don't eat the EOF.
+  if (LastChar == EOF)
+    return tok_eof;
+
+  // Otherwise, just return the character as its ascii value.
+  int ThisChar = LastChar;
+  LastChar = getchar();
+  return ThisChar;
+}
+
+//===----------------------------------------------------------------------===//
+// Abstract Syntax Tree (aka Parse Tree)
+//===----------------------------------------------------------------------===//
+
+class IRGenContext;
+
+/// ExprAST - Base class for all expression nodes.
+struct ExprAST {
+  virtual ~ExprAST() {}
+  virtual Value *IRGen(IRGenContext &C) const = 0;
+};
+
+/// NumberExprAST - Expression class for numeric literals like "1.0".
+struct NumberExprAST : public ExprAST {
+  NumberExprAST(double Val) : Val(Val) {}
+  Value *IRGen(IRGenContext &C) const override;
+
+  double Val;
+};
+
+/// VariableExprAST - Expression class for referencing a variable, like "a".
+struct VariableExprAST : public ExprAST {
+  VariableExprAST(std::string Name) : Name(std::move(Name)) {}
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::string Name;
+};
+
+/// UnaryExprAST - Expression class for a unary operator.
+struct UnaryExprAST : public ExprAST {
+  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand) 
+    : Opcode(std::move(Opcode)), Operand(std::move(Operand)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  char Opcode;
+  std::unique_ptr<ExprAST> Operand;
+};
+
+/// BinaryExprAST - Expression class for a binary operator.
+struct BinaryExprAST : public ExprAST {
+  BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
+                std::unique_ptr<ExprAST> RHS) 
+    : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  char Op;
+  std::unique_ptr<ExprAST> LHS, RHS;
+};
+
+/// CallExprAST - Expression class for function calls.
+struct CallExprAST : public ExprAST {
+  CallExprAST(std::string CalleeName,
+              std::vector<std::unique_ptr<ExprAST>> Args)
+    : CalleeName(std::move(CalleeName)), Args(std::move(Args)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::string CalleeName;
+  std::vector<std::unique_ptr<ExprAST>> Args;
+};
+
+/// IfExprAST - Expression class for if/then/else.
+struct IfExprAST : public ExprAST {
+  IfExprAST(std::unique_ptr<ExprAST> Cond, std::unique_ptr<ExprAST> Then,
+            std::unique_ptr<ExprAST> Else)
+    : Cond(std::move(Cond)), Then(std::move(Then)), Else(std::move(Else)) {}
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::unique_ptr<ExprAST> Cond, Then, Else;
+};
+
+/// ForExprAST - Expression class for for/in.
+struct ForExprAST : public ExprAST {
+  ForExprAST(std::string VarName, std::unique_ptr<ExprAST> Start,
+             std::unique_ptr<ExprAST> End, std::unique_ptr<ExprAST> Step,
+             std::unique_ptr<ExprAST> Body)
+    : VarName(std::move(VarName)), Start(std::move(Start)), End(std::move(End)),
+      Step(std::move(Step)), Body(std::move(Body)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::string VarName;
+  std::unique_ptr<ExprAST> Start, End, Step, Body;
+};
+
+/// VarExprAST - Expression class for var/in
+struct VarExprAST : public ExprAST {
+  typedef std::pair<std::string, std::unique_ptr<ExprAST>> Binding;
+  typedef std::vector<Binding> BindingList;
+
+  VarExprAST(BindingList VarBindings, std::unique_ptr<ExprAST> Body)
+    : VarBindings(std::move(VarBindings)), Body(std::move(Body)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  BindingList VarBindings;
+  std::unique_ptr<ExprAST> Body;
+};
+
+/// PrototypeAST - This class represents the "prototype" for a function,
+/// which captures its argument names as well as if it is an operator.
+struct PrototypeAST {
+  PrototypeAST(std::string Name, std::vector<std::string> Args,
+               bool IsOperator = false, unsigned Precedence = 0)
+    : Name(std::move(Name)), Args(std::move(Args)), IsOperator(IsOperator),
+      Precedence(Precedence) {}
+
+  Function *IRGen(IRGenContext &C) const;
+  void CreateArgumentAllocas(Function *F, IRGenContext &C);
+
+  bool isUnaryOp() const { return IsOperator && Args.size() == 1; }
+  bool isBinaryOp() const { return IsOperator && Args.size() == 2; }
+  
+  char getOperatorName() const {
+    assert(isUnaryOp() || isBinaryOp());
+    return Name[Name.size()-1];
+  }
+
+  std::string Name;
+  std::vector<std::string> Args;
+  bool IsOperator;
+  unsigned Precedence;  // Precedence if a binary op.
+};
+
+/// FunctionAST - This class represents a function definition itself.
+struct FunctionAST {
+  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
+              std::unique_ptr<ExprAST> Body)
+    : Proto(std::move(Proto)), Body(std::move(Body)) {}
+
+  Function *IRGen(IRGenContext &C) const;
+
+  std::unique_ptr<PrototypeAST> Proto;
+  std::unique_ptr<ExprAST> Body;
+};
+
+//===----------------------------------------------------------------------===//
+// Parser
+//===----------------------------------------------------------------------===//
+
+/// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
+/// token the parser is looking at.  getNextToken reads another token from the
+/// lexer and updates CurTok with its results.
+static int CurTok;
+static int getNextToken() {
+  return CurTok = gettok();
+}
+
+/// BinopPrecedence - This holds the precedence for each binary operator that is
+/// defined.
+static std::map<char, int> BinopPrecedence;
+
+/// GetTokPrecedence - Get the precedence of the pending binary operator token.
+static int GetTokPrecedence() {
+  if (!isascii(CurTok))
+    return -1;
+  
+  // Make sure it's a declared binop.
+  int TokPrec = BinopPrecedence[CurTok];
+  if (TokPrec <= 0) return -1;
+  return TokPrec;
+}
+
+template <typename T>
+std::unique_ptr<T> ErrorU(const std::string &Str) {
+  std::cerr << "Error: " << Str << "\n";
+  return nullptr;
+}
+
+template <typename T>
+T* ErrorP(const std::string &Str) {
+  std::cerr << "Error: " << Str << "\n";
+  return nullptr;
+}
+
+static std::unique_ptr<ExprAST> ParseExpression();
+
+/// identifierexpr
+///   ::= identifier
+///   ::= identifier '(' expression* ')'
+static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
+  std::string IdName = IdentifierStr;
+  
+  getNextToken();  // eat identifier.
+  
+  if (CurTok != '(') // Simple variable ref.
+    return llvm::make_unique<VariableExprAST>(IdName);
+  
+  // Call.
+  getNextToken();  // eat (
+  std::vector<std::unique_ptr<ExprAST>> Args;
+  if (CurTok != ')') {
+    while (1) {
+      auto Arg = ParseExpression();
+      if (!Arg) return nullptr;
+      Args.push_back(std::move(Arg));
+
+      if (CurTok == ')') break;
+
+      if (CurTok != ',')
+        return ErrorU<CallExprAST>("Expected ')' or ',' in argument list");
+      getNextToken();
+    }
+  }
+
+  // Eat the ')'.
+  getNextToken();
+  
+  return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
+}
+
+/// numberexpr ::= number
+static std::unique_ptr<NumberExprAST> ParseNumberExpr() {
+  auto Result = llvm::make_unique<NumberExprAST>(NumVal);
+  getNextToken(); // consume the number
+  return Result;
+}
+
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+  getNextToken();  // eat (.
+  auto V = ParseExpression();
+  if (!V)
+    return nullptr;
+  
+  if (CurTok != ')')
+    return ErrorU<ExprAST>("expected ')'");
+  getNextToken();  // eat ).
+  return V;
+}
+
+/// ifexpr ::= 'if' expression 'then' expression 'else' expression
+static std::unique_ptr<ExprAST> ParseIfExpr() {
+  getNextToken();  // eat the if.
+  
+  // condition.
+  auto Cond = ParseExpression();
+  if (!Cond)
+    return nullptr;
+  
+  if (CurTok != tok_then)
+    return ErrorU<ExprAST>("expected then");
+  getNextToken();  // eat the then
+  
+  auto Then = ParseExpression();
+  if (!Then)
+    return nullptr;
+  
+  if (CurTok != tok_else)
+    return ErrorU<ExprAST>("expected else");
+  
+  getNextToken();
+  
+  auto Else = ParseExpression();
+  if (!Else)
+    return nullptr;
+  
+  return llvm::make_unique<IfExprAST>(std::move(Cond), std::move(Then),
+                                      std::move(Else));
+}
+
+/// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
+static std::unique_ptr<ForExprAST> ParseForExpr() {
+  getNextToken();  // eat the for.
+
+  if (CurTok != tok_identifier)
+    return ErrorU<ForExprAST>("expected identifier after for");
+  
+  std::string IdName = IdentifierStr;
+  getNextToken();  // eat identifier.
+  
+  if (CurTok != '=')
+    return ErrorU<ForExprAST>("expected '=' after for");
+  getNextToken();  // eat '='.
+  
+  
+  auto Start = ParseExpression();
+  if (!Start)
+    return nullptr;
+  if (CurTok != ',')
+    return ErrorU<ForExprAST>("expected ',' after for start value");
+  getNextToken();
+  
+  auto End = ParseExpression();
+  if (!End)
+    return nullptr;
+  
+  // The step value is optional.
+  std::unique_ptr<ExprAST> Step;
+  if (CurTok == ',') {
+    getNextToken();
+    Step = ParseExpression();
+    if (!Step)
+      return nullptr;
+  }
+  
+  if (CurTok != tok_in)
+    return ErrorU<ForExprAST>("expected 'in' after for");
+  getNextToken();  // eat 'in'.
+  
+  auto Body = ParseExpression();
+  if (Body)
+    return nullptr;
+
+  return llvm::make_unique<ForExprAST>(IdName, std::move(Start), std::move(End),
+                                       std::move(Step), std::move(Body));
+}
+
+/// varexpr ::= 'var' identifier ('=' expression)? 
+//                    (',' identifier ('=' expression)?)* 'in' expression
+static std::unique_ptr<VarExprAST> ParseVarExpr() {
+  getNextToken();  // eat the var.
+
+  VarExprAST::BindingList VarBindings;
+
+  // At least one variable name is required.
+  if (CurTok != tok_identifier)
+    return ErrorU<VarExprAST>("expected identifier after var");
+  
+  while (1) {
+    std::string Name = IdentifierStr;
+    getNextToken();  // eat identifier.
+
+    // Read the optional initializer.
+    std::unique_ptr<ExprAST> Init;
+    if (CurTok == '=') {
+      getNextToken(); // eat the '='.
+      
+      Init = ParseExpression();
+      if (!Init)
+        return nullptr;
+    }
+    
+    VarBindings.push_back(VarExprAST::Binding(Name, std::move(Init)));
+    
+    // End of var list, exit loop.
+    if (CurTok != ',') break;
+    getNextToken(); // eat the ','.
+    
+    if (CurTok != tok_identifier)
+      return ErrorU<VarExprAST>("expected identifier list after var");
+  }
+  
+  // At this point, we have to have 'in'.
+  if (CurTok != tok_in)
+    return ErrorU<VarExprAST>("expected 'in' keyword after 'var'");
+  getNextToken();  // eat 'in'.
+  
+  auto Body = ParseExpression();
+  if (!Body)
+    return nullptr;
+  
+  return llvm::make_unique<VarExprAST>(std::move(VarBindings), std::move(Body));
+}
+
+/// primary
+///   ::= identifierexpr
+///   ::= numberexpr
+///   ::= parenexpr
+///   ::= ifexpr
+///   ::= forexpr
+///   ::= varexpr
+static std::unique_ptr<ExprAST> ParsePrimary() {
+  switch (CurTok) {
+  default: return ErrorU<ExprAST>("unknown token when expecting an expression");
+  case tok_identifier: return ParseIdentifierExpr();
+  case tok_number:     return ParseNumberExpr();
+  case '(':            return ParseParenExpr();
+  case tok_if:         return ParseIfExpr();
+  case tok_for:        return ParseForExpr();
+  case tok_var:        return ParseVarExpr();
+  }
+}
+
+/// unary
+///   ::= primary
+///   ::= '!' unary
+static std::unique_ptr<ExprAST> ParseUnary() {
+  // If the current token is not an operator, it must be a primary expr.
+  if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
+    return ParsePrimary();
+  
+  // If this is a unary operator, read it.
+  int Opc = CurTok;
+  getNextToken();
+  if (auto Operand = ParseUnary())
+    return llvm::make_unique<UnaryExprAST>(Opc, std::move(Operand));
+  return nullptr;
+}
+
+/// binoprhs
+///   ::= ('+' unary)*
+static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
+                                              std::unique_ptr<ExprAST> LHS) {
+  // If this is a binop, find its precedence.
+  while (1) {
+    int TokPrec = GetTokPrecedence();
+    
+    // If this is a binop that binds at least as tightly as the current binop,
+    // consume it, otherwise we are done.
+    if (TokPrec < ExprPrec)
+      return LHS;
+    
+    // Okay, we know this is a binop.
+    int BinOp = CurTok;
+    getNextToken();  // eat binop
+    
+    // Parse the unary expression after the binary operator.
+    auto RHS = ParseUnary();
+    if (!RHS)
+      return nullptr;
+    
+    // If BinOp binds less tightly with RHS than the operator after RHS, let
+    // the pending operator take RHS as its LHS.
+    int NextPrec = GetTokPrecedence();
+    if (TokPrec < NextPrec) {
+      RHS = ParseBinOpRHS(TokPrec+1, std::move(RHS));
+      if (!RHS)
+        return nullptr;
+    }
+    
+    // Merge LHS/RHS.
+    LHS = llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
+  }
+}
+
+/// expression
+///   ::= unary binoprhs
+///
+static std::unique_ptr<ExprAST> ParseExpression() {
+  auto LHS = ParseUnary();
+  if (!LHS)
+    return nullptr;
+  
+  return ParseBinOpRHS(0, std::move(LHS));
+}
+
+/// prototype
+///   ::= id '(' id* ')'
+///   ::= binary LETTER number? (id, id)
+///   ::= unary LETTER (id)
+static std::unique_ptr<PrototypeAST> ParsePrototype() {
+  std::string FnName;
+  
+  unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
+  unsigned BinaryPrecedence = 30;
+  
+  switch (CurTok) {
+  default:
+    return ErrorU<PrototypeAST>("Expected function name in prototype");
+  case tok_identifier:
+    FnName = IdentifierStr;
+    Kind = 0;
+    getNextToken();
+    break;
+  case tok_unary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorU<PrototypeAST>("Expected unary operator");
+    FnName = "unary";
+    FnName += (char)CurTok;
+    Kind = 1;
+    getNextToken();
+    break;
+  case tok_binary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorU<PrototypeAST>("Expected binary operator");
+    FnName = "binary";
+    FnName += (char)CurTok;
+    Kind = 2;
+    getNextToken();
+    
+    // Read the precedence if present.
+    if (CurTok == tok_number) {
+      if (NumVal < 1 || NumVal > 100)
+        return ErrorU<PrototypeAST>("Invalid precedecnce: must be 1..100");
+      BinaryPrecedence = (unsigned)NumVal;
+      getNextToken();
+    }
+    break;
+  }
+  
+  if (CurTok != '(')
+    return ErrorU<PrototypeAST>("Expected '(' in prototype");
+  
+  std::vector<std::string> ArgNames;
+  while (getNextToken() == tok_identifier)
+    ArgNames.push_back(IdentifierStr);
+  if (CurTok != ')')
+    return ErrorU<PrototypeAST>("Expected ')' in prototype");
+  
+  // success.
+  getNextToken();  // eat ')'.
+  
+  // Verify right number of names for operator.
+  if (Kind && ArgNames.size() != Kind)
+    return ErrorU<PrototypeAST>("Invalid number of operands for operator");
+  
+  return llvm::make_unique<PrototypeAST>(FnName, std::move(ArgNames), Kind != 0,
+                                         BinaryPrecedence);
+}
+
+/// definition ::= 'def' prototype expression
+static std::unique_ptr<FunctionAST> ParseDefinition() {
+  getNextToken();  // eat def.
+  auto Proto = ParsePrototype();
+  if (!Proto)
+    return nullptr;
+
+  if (auto Body = ParseExpression())
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(Body));
+  return nullptr;
+}
+
+/// toplevelexpr ::= expression
+static std::unique_ptr<FunctionAST> ParseTopLevelExpr() {
+  if (auto E = ParseExpression()) {
+    // Make an anonymous proto.
+    auto Proto =
+      llvm::make_unique<PrototypeAST>("__anon_expr", std::vector<std::string>());
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
+  }
+  return nullptr;
+}
+
+/// external ::= 'extern' prototype
+static std::unique_ptr<PrototypeAST> ParseExtern() {
+  getNextToken();  // eat extern.
+  return ParsePrototype();
+}
+
+//===----------------------------------------------------------------------===//
+// Code Generation
+//===----------------------------------------------------------------------===//
+
+// FIXME: Obviously we can do better than this
+std::string GenerateUniqueName(const std::string &Root) {
+  static int i = 0;
+  std::ostringstream NameStream;
+  NameStream << Root << ++i;
+  return NameStream.str();
+}
+
+std::string MakeLegalFunctionName(std::string Name)
+{
+  std::string NewName;
+  assert(!Name.empty() && "Base name must not be empty");
+
+  // Start with what we have
+  NewName = Name;
+
+  // Look for a numberic first character
+  if (NewName.find_first_of("0123456789") == 0) {
+    NewName.insert(0, 1, 'n');
+  }
+
+  // Replace illegal characters with their ASCII equivalent
+  std::string legal_elements = "_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+  size_t pos;
+  while ((pos = NewName.find_first_not_of(legal_elements)) != std::string::npos) {
+    std::ostringstream NumStream;
+    NumStream << (int)NewName.at(pos);
+    NewName = NewName.replace(pos, 1, NumStream.str());
+  }
+
+  return NewName;
+}
+
+class SessionContext {
+public:
+  SessionContext(LLVMContext &C)
+    : Context(C), TM(EngineBuilder().selectTarget()) {}
+  LLVMContext& getLLVMContext() const { return Context; }
+  TargetMachine& getTarget() { return *TM; }
+  void addPrototypeAST(std::unique_ptr<PrototypeAST> P);
+  PrototypeAST* getPrototypeAST(const std::string &Name);
+private:
+  typedef std::map<std::string, std::unique_ptr<PrototypeAST>> PrototypeMap;
+  
+  LLVMContext &Context;
+  std::unique_ptr<TargetMachine> TM;
+      
+  PrototypeMap Prototypes;
+};
+
+void SessionContext::addPrototypeAST(std::unique_ptr<PrototypeAST> P) {
+  Prototypes[P->Name] = std::move(P);
+}
+
+PrototypeAST* SessionContext::getPrototypeAST(const std::string &Name) {
+  PrototypeMap::iterator I = Prototypes.find(Name);
+  if (I != Prototypes.end())
+    return I->second.get();
+  return nullptr;
+}
+
+class IRGenContext {
+public:
+
+  IRGenContext(SessionContext &S)
+    : Session(S),
+      M(new Module(GenerateUniqueName("jit_module_"),
+                   Session.getLLVMContext())),
+      Builder(Session.getLLVMContext()) {
+    M->setDataLayout(Session.getTarget().getDataLayout());
+  }
+
+  SessionContext& getSession() { return Session; }
+  Module& getM() const { return *M; }
+  std::unique_ptr<Module> takeM() { return std::move(M); }
+  IRBuilder<>& getBuilder() { return Builder; }
+  LLVMContext& getLLVMContext() { return Session.getLLVMContext(); }
+  Function* getPrototype(const std::string &Name);
+
+  std::map<std::string, AllocaInst*> NamedValues;
+private:
+  SessionContext &Session;
+  std::unique_ptr<Module> M;
+  IRBuilder<> Builder;
+};
+
+Function* IRGenContext::getPrototype(const std::string &Name) {
+  if (Function *ExistingProto = M->getFunction(Name))
+    return ExistingProto;
+  if (PrototypeAST *ProtoAST = Session.getPrototypeAST(Name))
+    return ProtoAST->IRGen(*this);
+  return nullptr;
+}
+
+/// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
+/// the function.  This is used for mutable variables etc.
+static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
+                                          const std::string &VarName) {
+  IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
+                 TheFunction->getEntryBlock().begin());
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+                           VarName.c_str());
+}
+
+Value *NumberExprAST::IRGen(IRGenContext &C) const {
+  return ConstantFP::get(C.getLLVMContext(), APFloat(Val));
+}
+
+Value *VariableExprAST::IRGen(IRGenContext &C) const {
+  // Look this variable up in the function.
+  Value *V = C.NamedValues[Name];
+
+  if (V == 0)
+    return ErrorP<Value>("Unknown variable name '" + Name + "'");
+
+  // Load the value.
+  return C.getBuilder().CreateLoad(V, Name.c_str());
+}
+
+Value *UnaryExprAST::IRGen(IRGenContext &C) const {
+  if (Value *OperandV = Operand->IRGen(C)) {
+    std::string FnName = MakeLegalFunctionName(std::string("unary")+Opcode);
+    if (Function *F = C.getPrototype(FnName))
+      return C.getBuilder().CreateCall(F, OperandV, "unop");
+    return ErrorP<Value>("Unknown unary operator");
+  }
+
+  // Could not codegen operand - return null.
+  return nullptr;
+}
+
+Value *BinaryExprAST::IRGen(IRGenContext &C) const {
+  // Special case '=' because we don't want to emit the LHS as an expression.
+  if (Op == '=') {
+    // Assignment requires the LHS to be an identifier.
+    auto LHSVar = static_cast<VariableExprAST&>(*LHS);
+    // Codegen the RHS.
+    Value *Val = RHS->IRGen(C);
+    if (!Val) return nullptr;
+
+    // Look up the name.
+    if (auto Variable = C.NamedValues[LHSVar.Name]) {
+      C.getBuilder().CreateStore(Val, Variable);
+      return Val;
+    }
+    return ErrorP<Value>("Unknown variable name");
+  }
+  
+  Value *L = LHS->IRGen(C);
+  Value *R = RHS->IRGen(C);
+  if (!L || !R) return nullptr;
+  
+  switch (Op) {
+  case '+': return C.getBuilder().CreateFAdd(L, R, "addtmp");
+  case '-': return C.getBuilder().CreateFSub(L, R, "subtmp");
+  case '*': return C.getBuilder().CreateFMul(L, R, "multmp");
+  case '/': return C.getBuilder().CreateFDiv(L, R, "divtmp");
+  case '<':
+    L = C.getBuilder().CreateFCmpULT(L, R, "cmptmp");
+    // Convert bool 0/1 to double 0.0 or 1.0
+    return C.getBuilder().CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
+                                "booltmp");
+  default: break;
+  }
+  
+  // If it wasn't a builtin binary operator, it must be a user defined one. Emit
+  // a call to it.
+  std::string FnName = MakeLegalFunctionName(std::string("binary")+Op);
+  if (Function *F = C.getPrototype(FnName)) {
+    Value *Ops[] = { L, R };
+    return C.getBuilder().CreateCall(F, Ops, "binop");
+  }
+   
+  return ErrorP<Value>("Unknown binary operator");
+}
+
+Value *CallExprAST::IRGen(IRGenContext &C) const {
+  // Look up the name in the global module table.
+  if (auto CalleeF = C.getPrototype(CalleeName)) {
+    // If argument mismatch error.
+    if (CalleeF->arg_size() != Args.size())
+      return ErrorP<Value>("Incorrect # arguments passed");
+
+    std::vector<Value*> ArgsV;
+    for (unsigned i = 0, e = Args.size(); i != e; ++i) {
+      ArgsV.push_back(Args[i]->IRGen(C));
+      if (!ArgsV.back()) return nullptr;
+    }
+    
+    return C.getBuilder().CreateCall(CalleeF, ArgsV, "calltmp");
+  }
+
+  return ErrorP<Value>("Unknown function referenced");
+}
+
+Value *IfExprAST::IRGen(IRGenContext &C) const {
+  Value *CondV = Cond->IRGen(C);
+  if (!CondV) return nullptr;
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  ConstantFP *FPZero = 
+    ConstantFP::get(C.getLLVMContext(), APFloat(0.0));
+  CondV = C.getBuilder().CreateFCmpONE(CondV, FPZero, "ifcond");
+  
+  Function *TheFunction = C.getBuilder().GetInsertBlock()->getParent();
+  
+  // Create blocks for the then and else cases.  Insert the 'then' block at the
+  // end of the function.
+  BasicBlock *ThenBB = BasicBlock::Create(C.getLLVMContext(), "then", TheFunction);
+  BasicBlock *ElseBB = BasicBlock::Create(C.getLLVMContext(), "else");
+  BasicBlock *MergeBB = BasicBlock::Create(C.getLLVMContext(), "ifcont");
+  
+  C.getBuilder().CreateCondBr(CondV, ThenBB, ElseBB);
+  
+  // Emit then value.
+  C.getBuilder().SetInsertPoint(ThenBB);
+  
+  Value *ThenV = Then->IRGen(C);
+  if (!ThenV) return nullptr;
+  
+  C.getBuilder().CreateBr(MergeBB);
+  // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
+  ThenBB = C.getBuilder().GetInsertBlock();
+  
+  // Emit else block.
+  TheFunction->getBasicBlockList().push_back(ElseBB);
+  C.getBuilder().SetInsertPoint(ElseBB);
+  
+  Value *ElseV = Else->IRGen(C);
+  if (!ElseV) return nullptr;
+  
+  C.getBuilder().CreateBr(MergeBB);
+  // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
+  ElseBB = C.getBuilder().GetInsertBlock();
+  
+  // Emit merge block.
+  TheFunction->getBasicBlockList().push_back(MergeBB);
+  C.getBuilder().SetInsertPoint(MergeBB);
+  PHINode *PN = C.getBuilder().CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
+                                  "iftmp");
+  
+  PN->addIncoming(ThenV, ThenBB);
+  PN->addIncoming(ElseV, ElseBB);
+  return PN;
+}
+
+Value *ForExprAST::IRGen(IRGenContext &C) const {
+  // Output this as:
+  //   var = alloca double
+  //   ...
+  //   start = startexpr
+  //   store start -> var
+  //   goto loop
+  // loop: 
+  //   ...
+  //   bodyexpr
+  //   ...
+  // loopend:
+  //   step = stepexpr
+  //   endcond = endexpr
+  //
+  //   curvar = load var
+  //   nextvar = curvar + step
+  //   store nextvar -> var
+  //   br endcond, loop, endloop
+  // outloop:
+  
+  Function *TheFunction = C.getBuilder().GetInsertBlock()->getParent();
+
+  // Create an alloca for the variable in the entry block.
+  AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+  
+  // Emit the start code first, without 'variable' in scope.
+  Value *StartVal = Start->IRGen(C);
+  if (!StartVal) return nullptr;
+  
+  // Store the value into the alloca.
+  C.getBuilder().CreateStore(StartVal, Alloca);
+  
+  // Make the new basic block for the loop header, inserting after current
+  // block.
+  BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
+  
+  // Insert an explicit fall through from the current block to the LoopBB.
+  C.getBuilder().CreateBr(LoopBB);
+
+  // Start insertion in LoopBB.
+  C.getBuilder().SetInsertPoint(LoopBB);
+  
+  // Within the loop, the variable is defined equal to the PHI node.  If it
+  // shadows an existing variable, we have to restore it, so save it now.
+  AllocaInst *OldVal = C.NamedValues[VarName];
+  C.NamedValues[VarName] = Alloca;
+  
+  // Emit the body of the loop.  This, like any other expr, can change the
+  // current BB.  Note that we ignore the value computed by the body, but don't
+  // allow an error.
+  if (!Body->IRGen(C))
+    return nullptr;
+  
+  // Emit the step value.
+  Value *StepVal;
+  if (Step) {
+    StepVal = Step->IRGen(C);
+    if (!StepVal) return nullptr;
+  } else {
+    // If not specified, use 1.0.
+    StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
+  }
+  
+  // Compute the end condition.
+  Value *EndCond = End->IRGen(C);
+  if (EndCond == 0) return EndCond;
+  
+  // Reload, increment, and restore the alloca.  This handles the case where
+  // the body of the loop mutates the variable.
+  Value *CurVar = C.getBuilder().CreateLoad(Alloca, VarName.c_str());
+  Value *NextVar = C.getBuilder().CreateFAdd(CurVar, StepVal, "nextvar");
+  C.getBuilder().CreateStore(NextVar, Alloca);
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  EndCond = C.getBuilder().CreateFCmpONE(EndCond, 
+                              ConstantFP::get(getGlobalContext(), APFloat(0.0)),
+                                  "loopcond");
+  
+  // Create the "after loop" block and insert it.
+  BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
+  
+  // Insert the conditional branch into the end of LoopEndBB.
+  C.getBuilder().CreateCondBr(EndCond, LoopBB, AfterBB);
+  
+  // Any new code will be inserted in AfterBB.
+  C.getBuilder().SetInsertPoint(AfterBB);
+  
+  // Restore the unshadowed variable.
+  if (OldVal)
+    C.NamedValues[VarName] = OldVal;
+  else
+    C.NamedValues.erase(VarName);
+
+  
+  // for expr always returns 0.0.
+  return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
+}
+
+Value *VarExprAST::IRGen(IRGenContext &C) const {
+  std::vector<AllocaInst *> OldBindings;
+  
+  Function *TheFunction = C.getBuilder().GetInsertBlock()->getParent();
+
+  // Register all variables and emit their initializer.
+  for (unsigned i = 0, e = VarBindings.size(); i != e; ++i) {
+    auto &VarName = VarBindings[i].first;
+    auto &Init = VarBindings[i].second;
+    
+    // Emit the initializer before adding the variable to scope, this prevents
+    // the initializer from referencing the variable itself, and permits stuff
+    // like this:
+    //  var a = 1 in
+    //    var a = a in ...   # refers to outer 'a'.
+    Value *InitVal;
+    if (Init) {
+      InitVal = Init->IRGen(C);
+      if (!InitVal) return nullptr;
+    } else // If not specified, use 0.0.
+      InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
+    
+    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+    C.getBuilder().CreateStore(InitVal, Alloca);
+
+    // Remember the old variable binding so that we can restore the binding when
+    // we unrecurse.
+    OldBindings.push_back(C.NamedValues[VarName]);
+    
+    // Remember this binding.
+    C.NamedValues[VarName] = Alloca;
+  }
+  
+  // Codegen the body, now that all vars are in scope.
+  Value *BodyVal = Body->IRGen(C);
+  if (!BodyVal) return nullptr;
+  
+  // Pop all our variables from scope.
+  for (unsigned i = 0, e = VarBindings.size(); i != e; ++i)
+    C.NamedValues[VarBindings[i].first] = OldBindings[i];
+
+  // Return the body computation.
+  return BodyVal;
+}
+
+Function *PrototypeAST::IRGen(IRGenContext &C) const {
+  std::string FnName = MakeLegalFunctionName(Name);
+
+  // Make the function type:  double(double,double) etc.
+  std::vector<Type*> Doubles(Args.size(), 
+                             Type::getDoubleTy(getGlobalContext()));
+  FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
+                                       Doubles, false);
+  Function *F = Function::Create(FT, Function::ExternalLinkage, FnName,
+                                 &C.getM());
+
+  // If F conflicted, there was already something named 'FnName'.  If it has a
+  // body, don't allow redefinition or reextern.
+  if (F->getName() != FnName) {
+    // Delete the one we just made and get the existing one.
+    F->eraseFromParent();
+    F = C.getM().getFunction(Name);
+    
+    // If F already has a body, reject this.
+    if (!F->empty()) {
+      ErrorP<Function>("redefinition of function");
+      return nullptr;
+    }
+    
+    // If F took a different number of args, reject.
+    if (F->arg_size() != Args.size()) {
+      ErrorP<Function>("redefinition of function with different # args");
+      return nullptr;
+    }
+  }
+  
+  // Set names for all arguments.
+  unsigned Idx = 0;
+  for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
+       ++AI, ++Idx)
+    AI->setName(Args[Idx]);
+    
+  return F;
+}
+
+/// CreateArgumentAllocas - Create an alloca for each argument and register the
+/// argument in the symbol table so that references to it will succeed.
+void PrototypeAST::CreateArgumentAllocas(Function *F, IRGenContext &C) {
+  Function::arg_iterator AI = F->arg_begin();
+  for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
+    // Create an alloca for this variable.
+    AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
+
+    // Store the initial value into the alloca.
+    C.getBuilder().CreateStore(AI, Alloca);
+
+    // Add arguments to variable symbol table.
+    C.NamedValues[Args[Idx]] = Alloca;
+  }
+}
+
+Function *FunctionAST::IRGen(IRGenContext &C) const {
+  C.NamedValues.clear();
+  
+  Function *TheFunction = Proto->IRGen(C);
+  if (!TheFunction)
+    return nullptr;
+  
+  // If this is an operator, install it.
+  if (Proto->isBinaryOp())
+    BinopPrecedence[Proto->getOperatorName()] = Proto->Precedence;
+  
+  // Create a new basic block to start insertion into.
+  BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
+  C.getBuilder().SetInsertPoint(BB);
+  
+  // Add all arguments to the symbol table and create their allocas.
+  Proto->CreateArgumentAllocas(TheFunction, C);
+
+  if (Value *RetVal = Body->IRGen(C)) {
+    // Finish off the function.
+    C.getBuilder().CreateRet(RetVal);
+
+    // Validate the generated code, checking for consistency.
+    verifyFunction(*TheFunction);
+
+    return TheFunction;
+  }
+  
+  // Error reading body, remove function.
+  TheFunction->eraseFromParent();
+
+  if (Proto->isBinaryOp())
+    BinopPrecedence.erase(Proto->getOperatorName());
+  return nullptr;
+}
+
+//===----------------------------------------------------------------------===//
+// Top-Level parsing and JIT Driver
+//===----------------------------------------------------------------------===//
+
+static std::unique_ptr<llvm::Module> IRGen(SessionContext &S,
+                                           const FunctionAST &F) {
+  IRGenContext C(S);
+  auto LF = F.IRGen(C);
+  if (!LF)
+    return nullptr;
+#ifndef MINIMAL_STDERR_OUTPUT
+  fprintf(stderr, "Read function definition:");
+  LF->dump();
+#endif
+  return C.takeM();
+}
+
+template <typename T>
+static std::vector<T> singletonSet(T t) {
+  std::vector<T> Vec;
+  Vec.push_back(std::move(t));
+  return Vec;
+}
+
+class KaleidoscopeJIT {
+public:
+  typedef ObjectLinkingLayer<> ObjLayerT;
+  typedef IRCompileLayer<ObjLayerT> CompileLayerT;
+  typedef LazyEmittingLayer<CompileLayerT> LazyEmitLayerT;
+
+  typedef LazyEmitLayerT::ModuleSetHandleT ModuleHandleT;
+
+  KaleidoscopeJIT(SessionContext &Session)
+    : Mang(Session.getTarget().getDataLayout()),
+      CompileLayer(ObjectLayer, SimpleCompiler(Session.getTarget())),
+      LazyEmitLayer(CompileLayer) {}
+
+  std::string mangle(const std::string &Name) {
+    std::string MangledName;
+    {
+      raw_string_ostream MangledNameStream(MangledName);
+      Mang.getNameWithPrefix(MangledNameStream, Name);
+    }
+    return MangledName;
+  }
+
+  ModuleHandleT addModule(std::unique_ptr<Module> M) {
+    // We need a memory manager to allocate memory and resolve symbols for this
+    // new module. Create one that resolves symbols by looking back into the
+    // JIT.
+    auto MM = createLookasideRTDyldMM<SectionMemoryManager>(
+                [&](const std::string &Name) {
+                  return findSymbol(Name).getAddress();
+                },
+                [](const std::string &S) { return 0; } );
+
+    return LazyEmitLayer.addModuleSet(singletonSet(std::move(M)),
+                                      std::move(MM));
+  }
+
+  void removeModule(ModuleHandleT H) { LazyEmitLayer.removeModuleSet(H); }
+
+  JITSymbol findSymbol(const std::string &Name) {
+    return LazyEmitLayer.findSymbol(Name, true);
+  }
+
+  JITSymbol findUnmangledSymbol(const std::string Name) {
+    return findSymbol(mangle(Name));
+  }
+
+private:
+
+  Mangler Mang;
+  ObjLayerT ObjectLayer;
+  CompileLayerT CompileLayer;
+  LazyEmitLayerT LazyEmitLayer;
+};
+
+static void HandleDefinition(SessionContext &S, KaleidoscopeJIT &J) {
+  if (auto F = ParseDefinition()) {
+    if (auto M = IRGen(S, *F)) {
+      S.addPrototypeAST(llvm::make_unique<PrototypeAST>(*F->Proto));
+      J.addModule(std::move(M));
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleExtern(SessionContext &S) {
+  if (auto P = ParseExtern())
+    S.addPrototypeAST(std::move(P));
+  else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleTopLevelExpression(SessionContext &S, KaleidoscopeJIT &J) {
+  // Evaluate a top-level expression into an anonymous function.
+  if (auto F = ParseTopLevelExpr()) {
+    IRGenContext C(S);
+    if (auto ExprFunc = F->IRGen(C)) {
+#ifndef MINIMAL_STDERR_OUTPUT
+      std::cerr << "Expression function:\n";
+      ExprFunc->dump();
+#endif
+      // Add the CodeGen'd module to the JIT. Keep a handle to it: We can remove
+      // this module as soon as we've executed Function ExprFunc.
+      auto H = J.addModule(C.takeM());
+
+      // Get the address of the JIT'd function in memory.
+      auto ExprSymbol = J.findUnmangledSymbol("__anon_expr");
+      
+      // Cast it to the right type (takes no arguments, returns a double) so we
+      // can call it as a native function.
+      double (*FP)() = (double (*)())(intptr_t)ExprSymbol.getAddress();
+#ifdef MINIMAL_STDERR_OUTPUT
+      FP();
+#else
+      std::cerr << "Evaluated to " << FP() << "\n";
+#endif
+
+      // Remove the function.
+      J.removeModule(H);
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+/// top ::= definition | external | expression | ';'
+static void MainLoop() {
+  SessionContext S(getGlobalContext());
+  KaleidoscopeJIT J(S);
+
+  while (1) {
+    switch (CurTok) {
+    case tok_eof:    return;
+    case ';':        getNextToken(); continue;  // ignore top-level semicolons.
+    case tok_def:    HandleDefinition(S, J); break;
+    case tok_extern: HandleExtern(S); break;
+    default:         HandleTopLevelExpression(S, J); break;
+    }
+#ifndef MINIMAL_STDERR_OUTPUT
+    std::cerr << "ready> ";
+#endif
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// "Library" functions that can be "extern'd" from user code.
+//===----------------------------------------------------------------------===//
+
+/// putchard - putchar that takes a double and returns 0.
+extern "C" 
+double putchard(double X) {
+  putchar((char)X);
+  return 0;
+}
+
+/// printd - printf that takes a double prints it as "%f\n", returning 0.
+extern "C" 
+double printd(double X) {
+  printf("%f", X);
+  return 0;
+}
+
+extern "C" 
+double printlf() {
+  printf("\n");
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Main driver code.
+//===----------------------------------------------------------------------===//
+
+int main() {
+  InitializeNativeTarget();
+  InitializeNativeTargetAsmPrinter();
+  InitializeNativeTargetAsmParser();
+
+  // Install standard binary operators.
+  // 1 is lowest precedence.
+  BinopPrecedence['='] = 2;
+  BinopPrecedence['<'] = 10;
+  BinopPrecedence['+'] = 20;
+  BinopPrecedence['-'] = 20;
+  BinopPrecedence['/'] = 40;
+  BinopPrecedence['*'] = 40;  // highest.
+
+  // Prime the first token.
+#ifndef MINIMAL_STDERR_OUTPUT
+  std::cerr << "ready> ";
+#endif
+  getNextToken();
+
+  std::cerr << std::fixed;
+
+  // Run the main "interpreter loop" now.
+  MainLoop();
+
+  return 0;
+}
+
diff --git a/examples/Kaleidoscope/Orc/lazy_irgen/CMakeLists.txt b/examples/Kaleidoscope/Orc/lazy_irgen/CMakeLists.txt
new file mode 100644
index 0000000..4488681
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/lazy_irgen/CMakeLists.txt
@@ -0,0 +1,12 @@
+set(LLVM_LINK_COMPONENTS
+  Core
+  ExecutionEngine
+  Object
+  RuntimeDyld
+  Support
+  native
+  )
+
+add_kaleidoscope_chapter(Kaleidoscope-Orc-lazy_irgen
+  toy.cpp
+  )
diff --git a/examples/Kaleidoscope/Orc/lazy_irgen/Makefile b/examples/Kaleidoscope/Orc/lazy_irgen/Makefile
new file mode 100644
index 0000000..5536314
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/lazy_irgen/Makefile
@@ -0,0 +1,17 @@
+UNAME := $(shell uname -s)
+
+ifeq ($(UNAME),Darwin)
+	CXX := xcrun --sdk macosx clang++
+else
+	CXX := clang++
+endif
+
+LLVM_CXXFLAGS := $(shell llvm-config --cxxflags)
+LLVM_LDFLAGS := $(shell llvm-config  --ldflags --system-libs --libs core orcjit native)
+
+toy: toy.cpp
+	$(CXX) $(LLVM_CXXFLAGS) -Wall -std=c++11 -g -O0 -rdynamic -fno-rtti -o toy toy.cpp $(LLVM_LDFLAGS)
+
+.PHONY: clean
+clean:
+	rm -f toy
diff --git a/examples/Kaleidoscope/Orc/lazy_irgen/README.txt b/examples/Kaleidoscope/Orc/lazy_irgen/README.txt
new file mode 100644
index 0000000..9aaa431
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/lazy_irgen/README.txt
@@ -0,0 +1,16 @@
+//===----------------------------------------------------------------------===/
+//                 Kaleidoscope with Orc - Lazy IRGen Version
+//===----------------------------------------------------------------------===//
+
+This version of Kaleidoscope with Orc demonstrates lazy IR-generation.
+Building on the lazy-codegen version of the tutorial, this version reduces the
+amount of up-front work that must be done by lazily IRgen'ing ASTs. When a
+function definition is entered, its AST is added to a map of available
+definitions. No IRGen is performed at this point and nothing is added to the JIT.
+When attempting to resolve symbol addresses, the lambda in
+KaleidoscopeJIT::getSymbolAddress will scan the AST map and generate IR on the
+fly.
+
+This directory contains a Makefile that allows the code to be built in a
+standalone manner, independent of the larger LLVM build infrastructure. To build
+the program you will need to have 'clang++' and 'llvm-config' in your path.
diff --git a/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp b/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp
new file mode 100644
index 0000000..d7744ec
--- /dev/null
+++ b/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp
@@ -0,0 +1,1373 @@
+#include "llvm/Analysis/Passes.h"
+#include "llvm/ExecutionEngine/Orc/CompileUtils.h"
+#include "llvm/ExecutionEngine/Orc/IRCompileLayer.h"
+#include "llvm/ExecutionEngine/Orc/LazyEmittingLayer.h"
+#include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Transforms/Scalar.h"
+#include <cctype>
+#include <iomanip>
+#include <iostream>
+#include <map>
+#include <sstream>
+#include <string>
+#include <vector>
+
+using namespace llvm;
+using namespace llvm::orc;
+
+//===----------------------------------------------------------------------===//
+// Lexer
+//===----------------------------------------------------------------------===//
+
+// The lexer returns tokens [0-255] if it is an unknown character, otherwise one
+// of these for known things.
+enum Token {
+  tok_eof = -1,
+
+  // commands
+  tok_def = -2, tok_extern = -3,
+
+  // primary
+  tok_identifier = -4, tok_number = -5,
+  
+  // control
+  tok_if = -6, tok_then = -7, tok_else = -8,
+  tok_for = -9, tok_in = -10,
+  
+  // operators
+  tok_binary = -11, tok_unary = -12,
+  
+  // var definition
+  tok_var = -13
+};
+
+static std::string IdentifierStr;  // Filled in if tok_identifier
+static double NumVal;              // Filled in if tok_number
+
+/// gettok - Return the next token from standard input.
+static int gettok() {
+  static int LastChar = ' ';
+
+  // Skip any whitespace.
+  while (isspace(LastChar))
+    LastChar = getchar();
+
+  if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
+    IdentifierStr = LastChar;
+    while (isalnum((LastChar = getchar())))
+      IdentifierStr += LastChar;
+
+    if (IdentifierStr == "def") return tok_def;
+    if (IdentifierStr == "extern") return tok_extern;
+    if (IdentifierStr == "if") return tok_if;
+    if (IdentifierStr == "then") return tok_then;
+    if (IdentifierStr == "else") return tok_else;
+    if (IdentifierStr == "for") return tok_for;
+    if (IdentifierStr == "in") return tok_in;
+    if (IdentifierStr == "binary") return tok_binary;
+    if (IdentifierStr == "unary") return tok_unary;
+    if (IdentifierStr == "var") return tok_var;
+    return tok_identifier;
+  }
+
+  if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
+    std::string NumStr;
+    do {
+      NumStr += LastChar;
+      LastChar = getchar();
+    } while (isdigit(LastChar) || LastChar == '.');
+
+    NumVal = strtod(NumStr.c_str(), 0);
+    return tok_number;
+  }
+
+  if (LastChar == '#') {
+    // Comment until end of line.
+    do LastChar = getchar();
+    while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
+    
+    if (LastChar != EOF)
+      return gettok();
+  }
+  
+  // Check for end of file.  Don't eat the EOF.
+  if (LastChar == EOF)
+    return tok_eof;
+
+  // Otherwise, just return the character as its ascii value.
+  int ThisChar = LastChar;
+  LastChar = getchar();
+  return ThisChar;
+}
+
+//===----------------------------------------------------------------------===//
+// Abstract Syntax Tree (aka Parse Tree)
+//===----------------------------------------------------------------------===//
+
+class IRGenContext;
+
+/// ExprAST - Base class for all expression nodes.
+struct ExprAST {
+  virtual ~ExprAST() {}
+  virtual Value *IRGen(IRGenContext &C) const = 0;
+};
+
+/// NumberExprAST - Expression class for numeric literals like "1.0".
+struct NumberExprAST : public ExprAST {
+  NumberExprAST(double Val) : Val(Val) {}
+  Value *IRGen(IRGenContext &C) const override;
+
+  double Val;
+};
+
+/// VariableExprAST - Expression class for referencing a variable, like "a".
+struct VariableExprAST : public ExprAST {
+  VariableExprAST(std::string Name) : Name(std::move(Name)) {}
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::string Name;
+};
+
+/// UnaryExprAST - Expression class for a unary operator.
+struct UnaryExprAST : public ExprAST {
+  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand) 
+    : Opcode(std::move(Opcode)), Operand(std::move(Operand)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  char Opcode;
+  std::unique_ptr<ExprAST> Operand;
+};
+
+/// BinaryExprAST - Expression class for a binary operator.
+struct BinaryExprAST : public ExprAST {
+  BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
+                std::unique_ptr<ExprAST> RHS) 
+    : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  char Op;
+  std::unique_ptr<ExprAST> LHS, RHS;
+};
+
+/// CallExprAST - Expression class for function calls.
+struct CallExprAST : public ExprAST {
+  CallExprAST(std::string CalleeName,
+              std::vector<std::unique_ptr<ExprAST>> Args)
+    : CalleeName(std::move(CalleeName)), Args(std::move(Args)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::string CalleeName;
+  std::vector<std::unique_ptr<ExprAST>> Args;
+};
+
+/// IfExprAST - Expression class for if/then/else.
+struct IfExprAST : public ExprAST {
+  IfExprAST(std::unique_ptr<ExprAST> Cond, std::unique_ptr<ExprAST> Then,
+            std::unique_ptr<ExprAST> Else)
+    : Cond(std::move(Cond)), Then(std::move(Then)), Else(std::move(Else)) {}
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::unique_ptr<ExprAST> Cond, Then, Else;
+};
+
+/// ForExprAST - Expression class for for/in.
+struct ForExprAST : public ExprAST {
+  ForExprAST(std::string VarName, std::unique_ptr<ExprAST> Start,
+             std::unique_ptr<ExprAST> End, std::unique_ptr<ExprAST> Step,
+             std::unique_ptr<ExprAST> Body)
+    : VarName(std::move(VarName)), Start(std::move(Start)), End(std::move(End)),
+      Step(std::move(Step)), Body(std::move(Body)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  std::string VarName;
+  std::unique_ptr<ExprAST> Start, End, Step, Body;
+};
+
+/// VarExprAST - Expression class for var/in
+struct VarExprAST : public ExprAST {
+  typedef std::pair<std::string, std::unique_ptr<ExprAST>> Binding;
+  typedef std::vector<Binding> BindingList;
+
+  VarExprAST(BindingList VarBindings, std::unique_ptr<ExprAST> Body)
+    : VarBindings(std::move(VarBindings)), Body(std::move(Body)) {}
+
+  Value *IRGen(IRGenContext &C) const override;
+
+  BindingList VarBindings;
+  std::unique_ptr<ExprAST> Body;
+};
+
+/// PrototypeAST - This class represents the "prototype" for a function,
+/// which captures its argument names as well as if it is an operator.
+struct PrototypeAST {
+  PrototypeAST(std::string Name, std::vector<std::string> Args,
+               bool IsOperator = false, unsigned Precedence = 0)
+    : Name(std::move(Name)), Args(std::move(Args)), IsOperator(IsOperator),
+      Precedence(Precedence) {}
+
+  Function *IRGen(IRGenContext &C) const;
+  void CreateArgumentAllocas(Function *F, IRGenContext &C);
+
+  bool isUnaryOp() const { return IsOperator && Args.size() == 1; }
+  bool isBinaryOp() const { return IsOperator && Args.size() == 2; }
+  
+  char getOperatorName() const {
+    assert(isUnaryOp() || isBinaryOp());
+    return Name[Name.size()-1];
+  }
+
+  std::string Name;
+  std::vector<std::string> Args;
+  bool IsOperator;
+  unsigned Precedence;  // Precedence if a binary op.
+};
+
+/// FunctionAST - This class represents a function definition itself.
+struct FunctionAST {
+  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
+              std::unique_ptr<ExprAST> Body)
+    : Proto(std::move(Proto)), Body(std::move(Body)) {}
+
+  Function *IRGen(IRGenContext &C) const;
+
+  std::unique_ptr<PrototypeAST> Proto;
+  std::unique_ptr<ExprAST> Body;
+};
+
+//===----------------------------------------------------------------------===//
+// Parser
+//===----------------------------------------------------------------------===//
+
+/// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
+/// token the parser is looking at.  getNextToken reads another token from the
+/// lexer and updates CurTok with its results.
+static int CurTok;
+static int getNextToken() {
+  return CurTok = gettok();
+}
+
+/// BinopPrecedence - This holds the precedence for each binary operator that is
+/// defined.
+static std::map<char, int> BinopPrecedence;
+
+/// GetTokPrecedence - Get the precedence of the pending binary operator token.
+static int GetTokPrecedence() {
+  if (!isascii(CurTok))
+    return -1;
+  
+  // Make sure it's a declared binop.
+  int TokPrec = BinopPrecedence[CurTok];
+  if (TokPrec <= 0) return -1;
+  return TokPrec;
+}
+
+template <typename T>
+std::unique_ptr<T> ErrorU(const std::string &Str) {
+  std::cerr << "Error: " << Str << "\n";
+  return nullptr;
+}
+
+template <typename T>
+T* ErrorP(const std::string &Str) {
+  std::cerr << "Error: " << Str << "\n";
+  return nullptr;
+}
+
+static std::unique_ptr<ExprAST> ParseExpression();
+
+/// identifierexpr
+///   ::= identifier
+///   ::= identifier '(' expression* ')'
+static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
+  std::string IdName = IdentifierStr;
+  
+  getNextToken();  // eat identifier.
+  
+  if (CurTok != '(') // Simple variable ref.
+    return llvm::make_unique<VariableExprAST>(IdName);
+  
+  // Call.
+  getNextToken();  // eat (
+  std::vector<std::unique_ptr<ExprAST>> Args;
+  if (CurTok != ')') {
+    while (1) {
+      auto Arg = ParseExpression();
+      if (!Arg) return nullptr;
+      Args.push_back(std::move(Arg));
+
+      if (CurTok == ')') break;
+
+      if (CurTok != ',')
+        return ErrorU<CallExprAST>("Expected ')' or ',' in argument list");
+      getNextToken();
+    }
+  }
+
+  // Eat the ')'.
+  getNextToken();
+  
+  return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
+}
+
+/// numberexpr ::= number
+static std::unique_ptr<NumberExprAST> ParseNumberExpr() {
+  auto Result = llvm::make_unique<NumberExprAST>(NumVal);
+  getNextToken(); // consume the number
+  return Result;
+}
+
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+  getNextToken();  // eat (.
+  auto V = ParseExpression();
+  if (!V)
+    return nullptr;
+  
+  if (CurTok != ')')
+    return ErrorU<ExprAST>("expected ')'");
+  getNextToken();  // eat ).
+  return V;
+}
+
+/// ifexpr ::= 'if' expression 'then' expression 'else' expression
+static std::unique_ptr<ExprAST> ParseIfExpr() {
+  getNextToken();  // eat the if.
+  
+  // condition.
+  auto Cond = ParseExpression();
+  if (!Cond)
+    return nullptr;
+  
+  if (CurTok != tok_then)
+    return ErrorU<ExprAST>("expected then");
+  getNextToken();  // eat the then
+  
+  auto Then = ParseExpression();
+  if (!Then)
+    return nullptr;
+  
+  if (CurTok != tok_else)
+    return ErrorU<ExprAST>("expected else");
+  
+  getNextToken();
+  
+  auto Else = ParseExpression();
+  if (!Else)
+    return nullptr;
+  
+  return llvm::make_unique<IfExprAST>(std::move(Cond), std::move(Then),
+                                      std::move(Else));
+}
+
+/// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
+static std::unique_ptr<ForExprAST> ParseForExpr() {
+  getNextToken();  // eat the for.
+
+  if (CurTok != tok_identifier)
+    return ErrorU<ForExprAST>("expected identifier after for");
+  
+  std::string IdName = IdentifierStr;
+  getNextToken();  // eat identifier.
+  
+  if (CurTok != '=')
+    return ErrorU<ForExprAST>("expected '=' after for");
+  getNextToken();  // eat '='.
+  
+  
+  auto Start = ParseExpression();
+  if (!Start)
+    return nullptr;
+  if (CurTok != ',')
+    return ErrorU<ForExprAST>("expected ',' after for start value");
+  getNextToken();
+  
+  auto End = ParseExpression();
+  if (!End)
+    return nullptr;
+  
+  // The step value is optional.
+  std::unique_ptr<ExprAST> Step;
+  if (CurTok == ',') {
+    getNextToken();
+    Step = ParseExpression();
+    if (!Step)
+      return nullptr;
+  }
+  
+  if (CurTok != tok_in)
+    return ErrorU<ForExprAST>("expected 'in' after for");
+  getNextToken();  // eat 'in'.
+  
+  auto Body = ParseExpression();
+  if (Body)
+    return nullptr;
+
+  return llvm::make_unique<ForExprAST>(IdName, std::move(Start), std::move(End),
+                                       std::move(Step), std::move(Body));
+}
+
+/// varexpr ::= 'var' identifier ('=' expression)? 
+//                    (',' identifier ('=' expression)?)* 'in' expression
+static std::unique_ptr<VarExprAST> ParseVarExpr() {
+  getNextToken();  // eat the var.
+
+  VarExprAST::BindingList VarBindings;
+
+  // At least one variable name is required.
+  if (CurTok != tok_identifier)
+    return ErrorU<VarExprAST>("expected identifier after var");
+  
+  while (1) {
+    std::string Name = IdentifierStr;
+    getNextToken();  // eat identifier.
+
+    // Read the optional initializer.
+    std::unique_ptr<ExprAST> Init;
+    if (CurTok == '=') {
+      getNextToken(); // eat the '='.
+      
+      Init = ParseExpression();
+      if (!Init)
+        return nullptr;
+    }
+    
+    VarBindings.push_back(VarExprAST::Binding(Name, std::move(Init)));
+    
+    // End of var list, exit loop.
+    if (CurTok != ',') break;
+    getNextToken(); // eat the ','.
+    
+    if (CurTok != tok_identifier)
+      return ErrorU<VarExprAST>("expected identifier list after var");
+  }
+  
+  // At this point, we have to have 'in'.
+  if (CurTok != tok_in)
+    return ErrorU<VarExprAST>("expected 'in' keyword after 'var'");
+  getNextToken();  // eat 'in'.
+  
+  auto Body = ParseExpression();
+  if (!Body)
+    return nullptr;
+  
+  return llvm::make_unique<VarExprAST>(std::move(VarBindings), std::move(Body));
+}
+
+/// primary
+///   ::= identifierexpr
+///   ::= numberexpr
+///   ::= parenexpr
+///   ::= ifexpr
+///   ::= forexpr
+///   ::= varexpr
+static std::unique_ptr<ExprAST> ParsePrimary() {
+  switch (CurTok) {
+  default: return ErrorU<ExprAST>("unknown token when expecting an expression");
+  case tok_identifier: return ParseIdentifierExpr();
+  case tok_number:     return ParseNumberExpr();
+  case '(':            return ParseParenExpr();
+  case tok_if:         return ParseIfExpr();
+  case tok_for:        return ParseForExpr();
+  case tok_var:        return ParseVarExpr();
+  }
+}
+
+/// unary
+///   ::= primary
+///   ::= '!' unary
+static std::unique_ptr<ExprAST> ParseUnary() {
+  // If the current token is not an operator, it must be a primary expr.
+  if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
+    return ParsePrimary();
+  
+  // If this is a unary operator, read it.
+  int Opc = CurTok;
+  getNextToken();
+  if (auto Operand = ParseUnary())
+    return llvm::make_unique<UnaryExprAST>(Opc, std::move(Operand));
+  return nullptr;
+}
+
+/// binoprhs
+///   ::= ('+' unary)*
+static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
+                                              std::unique_ptr<ExprAST> LHS) {
+  // If this is a binop, find its precedence.
+  while (1) {
+    int TokPrec = GetTokPrecedence();
+    
+    // If this is a binop that binds at least as tightly as the current binop,
+    // consume it, otherwise we are done.
+    if (TokPrec < ExprPrec)
+      return LHS;
+    
+    // Okay, we know this is a binop.
+    int BinOp = CurTok;
+    getNextToken();  // eat binop
+    
+    // Parse the unary expression after the binary operator.
+    auto RHS = ParseUnary();
+    if (!RHS)
+      return nullptr;
+    
+    // If BinOp binds less tightly with RHS than the operator after RHS, let
+    // the pending operator take RHS as its LHS.
+    int NextPrec = GetTokPrecedence();
+    if (TokPrec < NextPrec) {
+      RHS = ParseBinOpRHS(TokPrec+1, std::move(RHS));
+      if (!RHS)
+        return nullptr;
+    }
+    
+    // Merge LHS/RHS.
+    LHS = llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
+  }
+}
+
+/// expression
+///   ::= unary binoprhs
+///
+static std::unique_ptr<ExprAST> ParseExpression() {
+  auto LHS = ParseUnary();
+  if (!LHS)
+    return nullptr;
+  
+  return ParseBinOpRHS(0, std::move(LHS));
+}
+
+/// prototype
+///   ::= id '(' id* ')'
+///   ::= binary LETTER number? (id, id)
+///   ::= unary LETTER (id)
+static std::unique_ptr<PrototypeAST> ParsePrototype() {
+  std::string FnName;
+  
+  unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
+  unsigned BinaryPrecedence = 30;
+  
+  switch (CurTok) {
+  default:
+    return ErrorU<PrototypeAST>("Expected function name in prototype");
+  case tok_identifier:
+    FnName = IdentifierStr;
+    Kind = 0;
+    getNextToken();
+    break;
+  case tok_unary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorU<PrototypeAST>("Expected unary operator");
+    FnName = "unary";
+    FnName += (char)CurTok;
+    Kind = 1;
+    getNextToken();
+    break;
+  case tok_binary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorU<PrototypeAST>("Expected binary operator");
+    FnName = "binary";
+    FnName += (char)CurTok;
+    Kind = 2;
+    getNextToken();
+    
+    // Read the precedence if present.
+    if (CurTok == tok_number) {
+      if (NumVal < 1 || NumVal > 100)
+        return ErrorU<PrototypeAST>("Invalid precedecnce: must be 1..100");
+      BinaryPrecedence = (unsigned)NumVal;
+      getNextToken();
+    }
+    break;
+  }
+  
+  if (CurTok != '(')
+    return ErrorU<PrototypeAST>("Expected '(' in prototype");
+  
+  std::vector<std::string> ArgNames;
+  while (getNextToken() == tok_identifier)
+    ArgNames.push_back(IdentifierStr);
+  if (CurTok != ')')
+    return ErrorU<PrototypeAST>("Expected ')' in prototype");
+  
+  // success.
+  getNextToken();  // eat ')'.
+  
+  // Verify right number of names for operator.
+  if (Kind && ArgNames.size() != Kind)
+    return ErrorU<PrototypeAST>("Invalid number of operands for operator");
+  
+  return llvm::make_unique<PrototypeAST>(FnName, std::move(ArgNames), Kind != 0,
+                                         BinaryPrecedence);
+}
+
+/// definition ::= 'def' prototype expression
+static std::unique_ptr<FunctionAST> ParseDefinition() {
+  getNextToken();  // eat def.
+  auto Proto = ParsePrototype();
+  if (!Proto)
+    return nullptr;
+
+  if (auto Body = ParseExpression())
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(Body));
+  return nullptr;
+}
+
+/// toplevelexpr ::= expression
+static std::unique_ptr<FunctionAST> ParseTopLevelExpr() {
+  if (auto E = ParseExpression()) {
+    // Make an anonymous proto.
+    auto Proto =
+      llvm::make_unique<PrototypeAST>("__anon_expr", std::vector<std::string>());
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
+  }
+  return nullptr;
+}
+
+/// external ::= 'extern' prototype
+static std::unique_ptr<PrototypeAST> ParseExtern() {
+  getNextToken();  // eat extern.
+  return ParsePrototype();
+}
+
+//===----------------------------------------------------------------------===//
+// Code Generation
+//===----------------------------------------------------------------------===//
+
+// FIXME: Obviously we can do better than this
+std::string GenerateUniqueName(const std::string &Root) {
+  static int i = 0;
+  std::ostringstream NameStream;
+  NameStream << Root << ++i;
+  return NameStream.str();
+}
+
+std::string MakeLegalFunctionName(std::string Name)
+{
+  std::string NewName;
+  assert(!Name.empty() && "Base name must not be empty");
+
+  // Start with what we have
+  NewName = Name;
+
+  // Look for a numberic first character
+  if (NewName.find_first_of("0123456789") == 0) {
+    NewName.insert(0, 1, 'n');
+  }
+
+  // Replace illegal characters with their ASCII equivalent
+  std::string legal_elements = "_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+  size_t pos;
+  while ((pos = NewName.find_first_not_of(legal_elements)) != std::string::npos) {
+    std::ostringstream NumStream;
+    NumStream << (int)NewName.at(pos);
+    NewName = NewName.replace(pos, 1, NumStream.str());
+  }
+
+  return NewName;
+}
+
+class SessionContext {
+public:
+  SessionContext(LLVMContext &C)
+    : Context(C), TM(EngineBuilder().selectTarget()) {}
+  LLVMContext& getLLVMContext() const { return Context; }
+  TargetMachine& getTarget() { return *TM; }
+  void addPrototypeAST(std::unique_ptr<PrototypeAST> P);
+  PrototypeAST* getPrototypeAST(const std::string &Name);
+private:
+  typedef std::map<std::string, std::unique_ptr<PrototypeAST>> PrototypeMap;
+  
+  LLVMContext &Context;
+  std::unique_ptr<TargetMachine> TM;
+      
+  PrototypeMap Prototypes;
+};
+
+void SessionContext::addPrototypeAST(std::unique_ptr<PrototypeAST> P) {
+  Prototypes[P->Name] = std::move(P);
+}
+
+PrototypeAST* SessionContext::getPrototypeAST(const std::string &Name) {
+  PrototypeMap::iterator I = Prototypes.find(Name);
+  if (I != Prototypes.end())
+    return I->second.get();
+  return nullptr;
+}
+
+class IRGenContext {
+public:
+
+  IRGenContext(SessionContext &S)
+    : Session(S),
+      M(new Module(GenerateUniqueName("jit_module_"),
+                   Session.getLLVMContext())),
+      Builder(Session.getLLVMContext()) {
+    M->setDataLayout(Session.getTarget().getDataLayout());
+  }
+
+  SessionContext& getSession() { return Session; }
+  Module& getM() const { return *M; }
+  std::unique_ptr<Module> takeM() { return std::move(M); }
+  IRBuilder<>& getBuilder() { return Builder; }
+  LLVMContext& getLLVMContext() { return Session.getLLVMContext(); }
+  Function* getPrototype(const std::string &Name);
+
+  std::map<std::string, AllocaInst*> NamedValues;
+private:
+  SessionContext &Session;
+  std::unique_ptr<Module> M;
+  IRBuilder<> Builder;
+};
+
+Function* IRGenContext::getPrototype(const std::string &Name) {
+  if (Function *ExistingProto = M->getFunction(Name))
+    return ExistingProto;
+  if (PrototypeAST *ProtoAST = Session.getPrototypeAST(Name))
+    return ProtoAST->IRGen(*this);
+  return nullptr;
+}
+
+/// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
+/// the function.  This is used for mutable variables etc.
+static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
+                                          const std::string &VarName) {
+  IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
+                 TheFunction->getEntryBlock().begin());
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+                           VarName.c_str());
+}
+
+Value *NumberExprAST::IRGen(IRGenContext &C) const {
+  return ConstantFP::get(C.getLLVMContext(), APFloat(Val));
+}
+
+Value *VariableExprAST::IRGen(IRGenContext &C) const {
+  // Look this variable up in the function.
+  Value *V = C.NamedValues[Name];
+
+  if (V == 0)
+    return ErrorP<Value>("Unknown variable name '" + Name + "'");
+
+  // Load the value.
+  return C.getBuilder().CreateLoad(V, Name.c_str());
+}
+
+Value *UnaryExprAST::IRGen(IRGenContext &C) const {
+  if (Value *OperandV = Operand->IRGen(C)) {
+    std::string FnName = MakeLegalFunctionName(std::string("unary")+Opcode);
+    if (Function *F = C.getPrototype(FnName))
+      return C.getBuilder().CreateCall(F, OperandV, "unop");
+    return ErrorP<Value>("Unknown unary operator");
+  }
+
+  // Could not codegen operand - return null.
+  return nullptr;
+}
+
+Value *BinaryExprAST::IRGen(IRGenContext &C) const {
+  // Special case '=' because we don't want to emit the LHS as an expression.
+  if (Op == '=') {
+    // Assignment requires the LHS to be an identifier.
+    auto LHSVar = static_cast<VariableExprAST&>(*LHS);
+    // Codegen the RHS.
+    Value *Val = RHS->IRGen(C);
+    if (!Val) return nullptr;
+
+    // Look up the name.
+    if (auto Variable = C.NamedValues[LHSVar.Name]) {
+      C.getBuilder().CreateStore(Val, Variable);
+      return Val;
+    }
+    return ErrorP<Value>("Unknown variable name");
+  }
+  
+  Value *L = LHS->IRGen(C);
+  Value *R = RHS->IRGen(C);
+  if (!L || !R) return nullptr;
+  
+  switch (Op) {
+  case '+': return C.getBuilder().CreateFAdd(L, R, "addtmp");
+  case '-': return C.getBuilder().CreateFSub(L, R, "subtmp");
+  case '*': return C.getBuilder().CreateFMul(L, R, "multmp");
+  case '/': return C.getBuilder().CreateFDiv(L, R, "divtmp");
+  case '<':
+    L = C.getBuilder().CreateFCmpULT(L, R, "cmptmp");
+    // Convert bool 0/1 to double 0.0 or 1.0
+    return C.getBuilder().CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
+                                "booltmp");
+  default: break;
+  }
+  
+  // If it wasn't a builtin binary operator, it must be a user defined one. Emit
+  // a call to it.
+  std::string FnName = MakeLegalFunctionName(std::string("binary")+Op);
+  if (Function *F = C.getPrototype(FnName)) {
+    Value *Ops[] = { L, R };
+    return C.getBuilder().CreateCall(F, Ops, "binop");
+  }
+   
+  return ErrorP<Value>("Unknown binary operator");
+}
+
+Value *CallExprAST::IRGen(IRGenContext &C) const {
+  // Look up the name in the global module table.
+  if (auto CalleeF = C.getPrototype(CalleeName)) {
+    // If argument mismatch error.
+    if (CalleeF->arg_size() != Args.size())
+      return ErrorP<Value>("Incorrect # arguments passed");
+
+    std::vector<Value*> ArgsV;
+    for (unsigned i = 0, e = Args.size(); i != e; ++i) {
+      ArgsV.push_back(Args[i]->IRGen(C));
+      if (!ArgsV.back()) return nullptr;
+    }
+    
+    return C.getBuilder().CreateCall(CalleeF, ArgsV, "calltmp");
+  }
+
+  return ErrorP<Value>("Unknown function referenced");
+}
+
+Value *IfExprAST::IRGen(IRGenContext &C) const {
+  Value *CondV = Cond->IRGen(C);
+  if (!CondV) return nullptr;
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  ConstantFP *FPZero = 
+    ConstantFP::get(C.getLLVMContext(), APFloat(0.0));
+  CondV = C.getBuilder().CreateFCmpONE(CondV, FPZero, "ifcond");
+  
+  Function *TheFunction = C.getBuilder().GetInsertBlock()->getParent();
+  
+  // Create blocks for the then and else cases.  Insert the 'then' block at the
+  // end of the function.
+  BasicBlock *ThenBB = BasicBlock::Create(C.getLLVMContext(), "then", TheFunction);
+  BasicBlock *ElseBB = BasicBlock::Create(C.getLLVMContext(), "else");
+  BasicBlock *MergeBB = BasicBlock::Create(C.getLLVMContext(), "ifcont");
+  
+  C.getBuilder().CreateCondBr(CondV, ThenBB, ElseBB);
+  
+  // Emit then value.
+  C.getBuilder().SetInsertPoint(ThenBB);
+  
+  Value *ThenV = Then->IRGen(C);
+  if (!ThenV) return nullptr;
+  
+  C.getBuilder().CreateBr(MergeBB);
+  // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
+  ThenBB = C.getBuilder().GetInsertBlock();
+  
+  // Emit else block.
+  TheFunction->getBasicBlockList().push_back(ElseBB);
+  C.getBuilder().SetInsertPoint(ElseBB);
+  
+  Value *ElseV = Else->IRGen(C);
+  if (!ElseV) return nullptr;
+  
+  C.getBuilder().CreateBr(MergeBB);
+  // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
+  ElseBB = C.getBuilder().GetInsertBlock();
+  
+  // Emit merge block.
+  TheFunction->getBasicBlockList().push_back(MergeBB);
+  C.getBuilder().SetInsertPoint(MergeBB);
+  PHINode *PN = C.getBuilder().CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
+                                  "iftmp");
+  
+  PN->addIncoming(ThenV, ThenBB);
+  PN->addIncoming(ElseV, ElseBB);
+  return PN;
+}
+
+Value *ForExprAST::IRGen(IRGenContext &C) const {
+  // Output this as:
+  //   var = alloca double
+  //   ...
+  //   start = startexpr
+  //   store start -> var
+  //   goto loop
+  // loop: 
+  //   ...
+  //   bodyexpr
+  //   ...
+  // loopend:
+  //   step = stepexpr
+  //   endcond = endexpr
+  //
+  //   curvar = load var
+  //   nextvar = curvar + step
+  //   store nextvar -> var
+  //   br endcond, loop, endloop
+  // outloop:
+  
+  Function *TheFunction = C.getBuilder().GetInsertBlock()->getParent();
+
+  // Create an alloca for the variable in the entry block.
+  AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+  
+  // Emit the start code first, without 'variable' in scope.
+  Value *StartVal = Start->IRGen(C);
+  if (!StartVal) return nullptr;
+  
+  // Store the value into the alloca.
+  C.getBuilder().CreateStore(StartVal, Alloca);
+  
+  // Make the new basic block for the loop header, inserting after current
+  // block.
+  BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
+  
+  // Insert an explicit fall through from the current block to the LoopBB.
+  C.getBuilder().CreateBr(LoopBB);
+
+  // Start insertion in LoopBB.
+  C.getBuilder().SetInsertPoint(LoopBB);
+  
+  // Within the loop, the variable is defined equal to the PHI node.  If it
+  // shadows an existing variable, we have to restore it, so save it now.
+  AllocaInst *OldVal = C.NamedValues[VarName];
+  C.NamedValues[VarName] = Alloca;
+  
+  // Emit the body of the loop.  This, like any other expr, can change the
+  // current BB.  Note that we ignore the value computed by the body, but don't
+  // allow an error.
+  if (!Body->IRGen(C))
+    return nullptr;
+  
+  // Emit the step value.
+  Value *StepVal;
+  if (Step) {
+    StepVal = Step->IRGen(C);
+    if (!StepVal) return nullptr;
+  } else {
+    // If not specified, use 1.0.
+    StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
+  }
+  
+  // Compute the end condition.
+  Value *EndCond = End->IRGen(C);
+  if (EndCond == 0) return EndCond;
+  
+  // Reload, increment, and restore the alloca.  This handles the case where
+  // the body of the loop mutates the variable.
+  Value *CurVar = C.getBuilder().CreateLoad(Alloca, VarName.c_str());
+  Value *NextVar = C.getBuilder().CreateFAdd(CurVar, StepVal, "nextvar");
+  C.getBuilder().CreateStore(NextVar, Alloca);
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  EndCond = C.getBuilder().CreateFCmpONE(EndCond, 
+                              ConstantFP::get(getGlobalContext(), APFloat(0.0)),
+                                  "loopcond");
+  
+  // Create the "after loop" block and insert it.
+  BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
+  
+  // Insert the conditional branch into the end of LoopEndBB.
+  C.getBuilder().CreateCondBr(EndCond, LoopBB, AfterBB);
+  
+  // Any new code will be inserted in AfterBB.
+  C.getBuilder().SetInsertPoint(AfterBB);
+  
+  // Restore the unshadowed variable.
+  if (OldVal)
+    C.NamedValues[VarName] = OldVal;
+  else
+    C.NamedValues.erase(VarName);
+
+  
+  // for expr always returns 0.0.
+  return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
+}
+
+Value *VarExprAST::IRGen(IRGenContext &C) const {
+  std::vector<AllocaInst *> OldBindings;
+  
+  Function *TheFunction = C.getBuilder().GetInsertBlock()->getParent();
+
+  // Register all variables and emit their initializer.
+  for (unsigned i = 0, e = VarBindings.size(); i != e; ++i) {
+    auto &VarName = VarBindings[i].first;
+    auto &Init = VarBindings[i].second;
+    
+    // Emit the initializer before adding the variable to scope, this prevents
+    // the initializer from referencing the variable itself, and permits stuff
+    // like this:
+    //  var a = 1 in
+    //    var a = a in ...   # refers to outer 'a'.
+    Value *InitVal;
+    if (Init) {
+      InitVal = Init->IRGen(C);
+      if (!InitVal) return nullptr;
+    } else // If not specified, use 0.0.
+      InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
+    
+    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+    C.getBuilder().CreateStore(InitVal, Alloca);
+
+    // Remember the old variable binding so that we can restore the binding when
+    // we unrecurse.
+    OldBindings.push_back(C.NamedValues[VarName]);
+    
+    // Remember this binding.
+    C.NamedValues[VarName] = Alloca;
+  }
+  
+  // Codegen the body, now that all vars are in scope.
+  Value *BodyVal = Body->IRGen(C);
+  if (!BodyVal) return nullptr;
+  
+  // Pop all our variables from scope.
+  for (unsigned i = 0, e = VarBindings.size(); i != e; ++i)
+    C.NamedValues[VarBindings[i].first] = OldBindings[i];
+
+  // Return the body computation.
+  return BodyVal;
+}
+
+Function *PrototypeAST::IRGen(IRGenContext &C) const {
+  std::string FnName = MakeLegalFunctionName(Name);
+
+  // Make the function type:  double(double,double) etc.
+  std::vector<Type*> Doubles(Args.size(), 
+                             Type::getDoubleTy(getGlobalContext()));
+  FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
+                                       Doubles, false);
+  Function *F = Function::Create(FT, Function::ExternalLinkage, FnName,
+                                 &C.getM());
+
+  // If F conflicted, there was already something named 'FnName'.  If it has a
+  // body, don't allow redefinition or reextern.
+  if (F->getName() != FnName) {
+    // Delete the one we just made and get the existing one.
+    F->eraseFromParent();
+    F = C.getM().getFunction(Name);
+    
+    // If F already has a body, reject this.
+    if (!F->empty()) {
+      ErrorP<Function>("redefinition of function");
+      return nullptr;
+    }
+    
+    // If F took a different number of args, reject.
+    if (F->arg_size() != Args.size()) {
+      ErrorP<Function>("redefinition of function with different # args");
+      return nullptr;
+    }
+  }
+  
+  // Set names for all arguments.
+  unsigned Idx = 0;
+  for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
+       ++AI, ++Idx)
+    AI->setName(Args[Idx]);
+    
+  return F;
+}
+
+/// CreateArgumentAllocas - Create an alloca for each argument and register the
+/// argument in the symbol table so that references to it will succeed.
+void PrototypeAST::CreateArgumentAllocas(Function *F, IRGenContext &C) {
+  Function::arg_iterator AI = F->arg_begin();
+  for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
+    // Create an alloca for this variable.
+    AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
+
+    // Store the initial value into the alloca.
+    C.getBuilder().CreateStore(AI, Alloca);
+
+    // Add arguments to variable symbol table.
+    C.NamedValues[Args[Idx]] = Alloca;
+  }
+}
+
+Function *FunctionAST::IRGen(IRGenContext &C) const {
+  C.NamedValues.clear();
+  
+  Function *TheFunction = Proto->IRGen(C);
+  if (!TheFunction)
+    return nullptr;
+  
+  // If this is an operator, install it.
+  if (Proto->isBinaryOp())
+    BinopPrecedence[Proto->getOperatorName()] = Proto->Precedence;
+  
+  // Create a new basic block to start insertion into.
+  BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
+  C.getBuilder().SetInsertPoint(BB);
+  
+  // Add all arguments to the symbol table and create their allocas.
+  Proto->CreateArgumentAllocas(TheFunction, C);
+
+  if (Value *RetVal = Body->IRGen(C)) {
+    // Finish off the function.
+    C.getBuilder().CreateRet(RetVal);
+
+    // Validate the generated code, checking for consistency.
+    verifyFunction(*TheFunction);
+
+    return TheFunction;
+  }
+  
+  // Error reading body, remove function.
+  TheFunction->eraseFromParent();
+
+  if (Proto->isBinaryOp())
+    BinopPrecedence.erase(Proto->getOperatorName());
+  return nullptr;
+}
+
+//===----------------------------------------------------------------------===//
+// Top-Level parsing and JIT Driver
+//===----------------------------------------------------------------------===//
+
+static std::unique_ptr<llvm::Module> IRGen(SessionContext &S,
+                                           const FunctionAST &F) {
+  IRGenContext C(S);
+  auto LF = F.IRGen(C);
+  if (!LF)
+    return nullptr;
+#ifndef MINIMAL_STDERR_OUTPUT
+  fprintf(stderr, "Read function definition:");
+  LF->dump();
+#endif
+  return C.takeM();
+}
+
+template <typename T>
+static std::vector<T> singletonSet(T t) {
+  std::vector<T> Vec;
+  Vec.push_back(std::move(t));
+  return Vec;
+}
+
+class KaleidoscopeJIT {
+public:
+  typedef ObjectLinkingLayer<> ObjLayerT;
+  typedef IRCompileLayer<ObjLayerT> CompileLayerT;
+  typedef LazyEmittingLayer<CompileLayerT> LazyEmitLayerT;
+  typedef LazyEmitLayerT::ModuleSetHandleT ModuleHandleT;
+
+  KaleidoscopeJIT(SessionContext &Session)
+    : Session(Session),
+      Mang(Session.getTarget().getDataLayout()),
+      CompileLayer(ObjectLayer, SimpleCompiler(Session.getTarget())),
+      LazyEmitLayer(CompileLayer) {}
+
+  std::string mangle(const std::string &Name) {
+    std::string MangledName;
+    {
+      raw_string_ostream MangledNameStream(MangledName);
+      Mang.getNameWithPrefix(MangledNameStream, Name);
+    }
+    return MangledName;
+  }
+
+  void addFunctionDefinition(std::unique_ptr<FunctionAST> FnAST) {
+    FunctionDefs[mangle(FnAST->Proto->Name)] = std::move(FnAST);
+  }
+
+  ModuleHandleT addModule(std::unique_ptr<Module> M) {
+    // We need a memory manager to allocate memory and resolve symbols for this
+    // new module. Create one that resolves symbols by looking back into the
+    // JIT.
+    auto MM = createLookasideRTDyldMM<SectionMemoryManager>(
+                [&](const std::string &Name) {
+                  // First try to find 'Name' within the JIT.
+                  if (auto Symbol = findSymbol(Name))
+                    return Symbol.getAddress();
+
+                  // If we don't already have a definition of 'Name' then search
+                  // the ASTs.
+                  return searchUncompiledASTs(Name);
+                },
+                [](const std::string &S) { return 0; } );
+
+    return LazyEmitLayer.addModuleSet(singletonSet(std::move(M)),
+                                      std::move(MM));
+  }
+
+  void removeModule(ModuleHandleT H) { LazyEmitLayer.removeModuleSet(H); }
+
+  JITSymbol findSymbol(const std::string &Name) {
+    return LazyEmitLayer.findSymbol(Name, true);
+  }
+
+  JITSymbol findSymbolIn(ModuleHandleT H, const std::string &Name) {
+    return LazyEmitLayer.findSymbolIn(H, Name, true);
+  }
+
+  JITSymbol findUnmangledSymbol(const std::string &Name) {
+    return findSymbol(mangle(Name));
+  }
+
+private:
+
+  // This method searches the FunctionDefs map for a definition of 'Name'. If it
+  // finds one it generates a stub for it and returns the address of the stub.
+  TargetAddress searchUncompiledASTs(const std::string &Name) {
+    auto DefI = FunctionDefs.find(Name);
+    if (DefI == FunctionDefs.end())
+      return 0;
+
+    // We have AST for 'Name'. IRGen it, add it to the JIT, and
+    // return the address for it.
+    // FIXME: What happens if IRGen fails?
+    auto H = addModule(IRGen(Session, *DefI->second));
+
+    // Remove the function definition's AST now that we're
+    // finished with it.
+    FunctionDefs.erase(DefI);
+
+    // Return the address of the function.
+    return findSymbolIn(H, Name).getAddress();
+  }
+
+  SessionContext &Session;
+  Mangler Mang;
+  ObjLayerT ObjectLayer;
+  CompileLayerT CompileLayer;
+  LazyEmitLayerT LazyEmitLayer;
+
+  std::map<std::string, std::unique_ptr<FunctionAST>> FunctionDefs;
+};
+
+static void HandleDefinition(SessionContext &S, KaleidoscopeJIT &J) {
+  if (auto F = ParseDefinition()) {
+    S.addPrototypeAST(llvm::make_unique<PrototypeAST>(*F->Proto));
+    J.addFunctionDefinition(std::move(F));
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleExtern(SessionContext &S) {
+  if (auto P = ParseExtern())
+    S.addPrototypeAST(std::move(P));
+  else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleTopLevelExpression(SessionContext &S, KaleidoscopeJIT &J) {
+  // Evaluate a top-level expression into an anonymous function.
+  if (auto F = ParseTopLevelExpr()) {
+    IRGenContext C(S);
+    if (auto ExprFunc = F->IRGen(C)) {
+#ifndef MINIMAL_STDERR_OUTPUT
+      std::cerr << "Expression function:\n";
+      ExprFunc->dump();
+#endif
+      // Add the CodeGen'd module to the JIT. Keep a handle to it: We can remove
+      // this module as soon as we've executed Function ExprFunc.
+      auto H = J.addModule(C.takeM());
+
+      // Get the address of the JIT'd function in memory.
+      auto ExprSymbol = J.findUnmangledSymbol("__anon_expr");
+      
+      // Cast it to the right type (takes no arguments, returns a double) so we
+      // can call it as a native function.
+      double (*FP)() = (double (*)())(intptr_t)ExprSymbol.getAddress();
+#ifdef MINIMAL_STDERR_OUTPUT
+      FP();
+#else
+      std::cerr << "Evaluated to " << FP() << "\n";
+#endif
+
+      // Remove the function.
+      J.removeModule(H);
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+/// top ::= definition | external | expression | ';'
+static void MainLoop() {
+  SessionContext S(getGlobalContext());
+  KaleidoscopeJIT J(S);
+
+  while (1) {
+    switch (CurTok) {
+    case tok_eof:    return;
+    case ';':        getNextToken(); continue;  // ignore top-level semicolons.
+    case tok_def:    HandleDefinition(S, J); break;
+    case tok_extern: HandleExtern(S); break;
+    default:         HandleTopLevelExpression(S, J); break;
+    }
+#ifndef MINIMAL_STDERR_OUTPUT
+    std::cerr << "ready> ";
+#endif
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// "Library" functions that can be "extern'd" from user code.
+//===----------------------------------------------------------------------===//
+
+/// putchard - putchar that takes a double and returns 0.
+extern "C" 
+double putchard(double X) {
+  putchar((char)X);
+  return 0;
+}
+
+/// printd - printf that takes a double prints it as "%f\n", returning 0.
+extern "C" 
+double printd(double X) {
+  printf("%f", X);
+  return 0;
+}
+
+extern "C" 
+double printlf() {
+  printf("\n");
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Main driver code.
+//===----------------------------------------------------------------------===//
+
+int main() {
+  InitializeNativeTarget();
+  InitializeNativeTargetAsmPrinter();
+  InitializeNativeTargetAsmParser();
+
+  // Install standard binary operators.
+  // 1 is lowest precedence.
+  BinopPrecedence['='] = 2;
+  BinopPrecedence['<'] = 10;
+  BinopPrecedence['+'] = 20;
+  BinopPrecedence['-'] = 20;
+  BinopPrecedence['/'] = 40;
+  BinopPrecedence['*'] = 40;  // highest.
+
+  // Prime the first token.
+#ifndef MINIMAL_STDERR_OUTPUT
+  std::cerr << "ready> ";
+#endif
+  getNextToken();
+
+  std::cerr << std::fixed;
+
+  // Run the main "interpreter loop" now.
+  MainLoop();
+
+  return 0;
+}
+