27 files changed, 2558 insertions, 2613 deletions

diff --git a/examples/BrainF/BrainF.cpp b/examples/BrainF/BrainF.cpp
index 8026adc8d075..d8c54b50b854 100644
--- a/examples/BrainF/BrainF.cpp
+++ b/examples/BrainF/BrainF.cpp
@@ -29,6 +29,7 @@
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Intrinsics.h"
 #include <iostream>
+
 using namespace llvm;
 
 //Set the constants for naming
@@ -44,7 +45,7 @@ Module *BrainF::parse(std::istream *in1, int mem, CompileFlags cf,
   comflag  = cf;
 
   header(Context);
-  readloop(0, 0, 0, Context);
+  readloop(nullptr, nullptr, nullptr, Context);
   delete builder;
   return module;
 }
@@ -68,7 +69,6 @@ void BrainF::header(LLVMContext& C) {
     getOrInsertFunction("putchar", IntegerType::getInt32Ty(C),
                         IntegerType::getInt32Ty(C), NULL));
 
-
   //Function header
 
   //define void @brainf()
@@ -85,7 +85,7 @@ void BrainF::header(LLVMContext& C) {
   Constant* allocsize = ConstantExpr::getSizeOf(Int8Ty);
   allocsize = ConstantExpr::getTruncOrBitCast(allocsize, IntPtrTy);
   ptr_arr = CallInst::CreateMalloc(BB, IntPtrTy, Int8Ty, allocsize, val_mem, 
-                                   NULL, "arr");
+                                   nullptr, "arr");
   BB->getInstList().push_back(cast<Instruction>(ptr_arr));
 
   //call void @llvm.memset.p0i8.i32(i8 *%arr, i8 0, i32 %d, i32 1, i1 0)
@@ -114,8 +114,6 @@ void BrainF::header(LLVMContext& C) {
                                ConstantInt::get(C, APInt(32, memtotal/2)),
                                headreg);
 
-
-
   //Function footer
 
   //brainf.end:
@@ -127,8 +125,6 @@ void BrainF::header(LLVMContext& C) {
   //ret void
   ReturnInst::Create(C, endbb);
 
-
-
   //Error block for array out of bounds
   if (comflag & flag_arraybounds)
   {
diff --git a/examples/BrainF/BrainFDriver.cpp b/examples/BrainF/BrainFDriver.cpp
index 99c8ff36dc61..1a38c67b0d4a 100644
--- a/examples/BrainF/BrainFDriver.cpp
+++ b/examples/BrainF/BrainFDriver.cpp
@@ -64,9 +64,9 @@ void addMainFunction(Module *mod) {
                           IntegerType::getInt8Ty(mod->getContext()))), NULL));
   {
     Function::arg_iterator args = main_func->arg_begin();
-    Value *arg_0 = args++;
+    Value *arg_0 = &*args++;
     arg_0->setName("argc");
-    Value *arg_1 = args++;
+    Value *arg_1 = &*args++;
     arg_1->setName("argv");
   }
 
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index f98c403deb0b..5727066d6227 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -4,7 +4,7 @@ add_subdirectory(HowToUseJIT)
 add_subdirectory(Kaleidoscope)
 add_subdirectory(ModuleMaker)
 
-if( ( NOT WIN32 ) AND ( NOT "${LLVM_NATIVE_ARCH}" STREQUAL "ARM" ) )
+if(LLVM_ENABLE_EH AND (NOT WIN32) AND (NOT "${LLVM_NATIVE_ARCH}" STREQUAL "ARM"))
     add_subdirectory(ExceptionDemo)
 endif()
 
diff --git a/examples/ExceptionDemo/CMakeLists.txt b/examples/ExceptionDemo/CMakeLists.txt
index b4354f66f0d6..793cf291ca6f 100644
--- a/examples/ExceptionDemo/CMakeLists.txt
+++ b/examples/ExceptionDemo/CMakeLists.txt
@@ -5,14 +5,14 @@ set(LLVM_LINK_COMPONENTS
   MCJIT
   RuntimeDyld
   Support
+  Target
   nativecodegen
   )
 
 # Enable EH and RTTI for this demo
-set(LLVM_REQUIRES_EH 1)
-set(LLVM_REQUIRES_RTTI 1)
-
-set(LLVM_BUILD_EXAMPLES OFF)
+if(NOT LLVM_ENABLE_EH)
+  message(FATAL_ERROR "ExceptionDemo must require EH.")
+endif()
 
 add_llvm_example(ExceptionDemo
   ExceptionDemo.cpp
diff --git a/examples/ExceptionDemo/ExceptionDemo.cpp b/examples/ExceptionDemo/ExceptionDemo.cpp
index 81337c4823b0..444ee2649fa7 100644
--- a/examples/ExceptionDemo/ExceptionDemo.cpp
+++ b/examples/ExceptionDemo/ExceptionDemo.cpp
@@ -77,6 +77,7 @@
 #include <sstream>
 #include <stdexcept>
 
+#include <inttypes.h>
 
 #ifndef USE_GLOBAL_STR_CONSTS
 #define USE_GLOBAL_STR_CONSTS true
@@ -319,7 +320,7 @@ void printStr(char *toPrint) {
 }
 
 
-/// Deletes the true previosly allocated exception whose address
+/// Deletes the true previously allocated exception whose address
 /// is calculated from the supplied OurBaseException_t::unwindException
 /// member address. Handles (ignores), NULL pointers.
 /// @param expToDelete exception to delete
@@ -569,8 +570,8 @@ static bool handleActionValue(int64_t *resultAction,
   fprintf(stderr,
           "handleActionValue(...): exceptionObject = <%p>, "
           "excp = <%p>.\n",
-          exceptionObject,
-          excp);
+          (void*)exceptionObject,
+          (void*)excp);
 #endif
 
   const uint8_t *actionPos = (uint8_t*) actionEntry,
@@ -588,8 +589,8 @@ static bool handleActionValue(int64_t *resultAction,
 
 #ifdef DEBUG
     fprintf(stderr,
-            "handleActionValue(...):typeOffset: <%lld>, "
-            "actionOffset: <%lld>.\n",
+            "handleActionValue(...):typeOffset: <%" PRIi64 ">, "
+            "actionOffset: <%" PRIi64 ">.\n",
             typeOffset,
             actionOffset);
 #endif
@@ -848,7 +849,7 @@ _Unwind_Reason_Code ourPersonality(int version,
 #ifdef DEBUG
   fprintf(stderr,
           "ourPersonality(...):lsda = <%p>.\n",
-          lsda);
+          (void*)lsda);
 #endif
 
   // The real work of the personality function is captured here
@@ -971,7 +972,7 @@ void generateIntegerPrint(llvm::LLVMContext &context,
 
   llvm::Value *cast = builder.CreateBitCast(stringVar,
                                             builder.getInt8PtrTy());
-  builder.CreateCall2(&printFunct, &toPrint, cast);
+  builder.CreateCall(&printFunct, {&toPrint, cast});
 }
 
 
@@ -1264,10 +1265,10 @@ static llvm::Function *createCatchWrappedInvokeFunction(
   builder.SetInsertPoint(exceptionBlock);
 
   llvm::Function *personality = module.getFunction("ourPersonality");
+  ret->setPersonalityFn(personality);
 
   llvm::LandingPadInst *caughtResult =
     builder.CreateLandingPad(ourCaughtResultType,
-                             personality,
                              numExceptionsToCatch,
                              "landingPad");
 
@@ -1694,7 +1695,7 @@ static void createStandardUtilityFunctions(unsigned numTypeInfos,
 #ifdef DEBUG
   fprintf(stderr,
           "createStandardUtilityFunctions(...):ourBaseFromUnwindOffset "
-          "= %lld, sizeof(struct OurBaseException_t) - "
+          "= %" PRIi64 ", sizeof(struct OurBaseException_t) - "
           "sizeof(struct _Unwind_Exception) = %lu.\n",
           ourBaseFromUnwindOffset,
           sizeof(struct OurBaseException_t) -
@@ -1973,7 +1974,7 @@ int main(int argc, char *argv[]) {
     // Set up the optimizer pipeline.
     // Start with registering info about how the
     // target lays out data structures.
-    module->setDataLayout(*executionEngine->getDataLayout());
+    module->setDataLayout(executionEngine->getDataLayout());
 
     // Optimizations turned on
 #ifdef ADD_OPT_PASSES
diff --git a/examples/Fibonacci/fibonacci.cpp b/examples/Fibonacci/fibonacci.cpp
index 8092e19380dd..ecb49eb92e1a 100644
--- a/examples/Fibonacci/fibonacci.cpp
+++ b/examples/Fibonacci/fibonacci.cpp
@@ -33,6 +33,7 @@
 #include "llvm/IR/Module.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/raw_ostream.h"
+
 using namespace llvm;
 
 static Function *CreateFibFunction(Module *M, LLVMContext &Context) {
@@ -41,7 +42,7 @@ static Function *CreateFibFunction(Module *M, LLVMContext &Context) {
   Function *FibF =
     cast<Function>(M->getOrInsertFunction("fib", Type::getInt32Ty(Context),
                                           Type::getInt32Ty(Context),
-                                          (Type *)0));
+                                          nullptr));
 
   // Add a basic block to the function.
   BasicBlock *BB = BasicBlock::Create(Context, "EntryBlock", FibF);
@@ -51,7 +52,7 @@ static Function *CreateFibFunction(Module *M, LLVMContext &Context) {
   Value *Two = ConstantInt::get(Type::getInt32Ty(Context), 2);
 
   // Get pointer to the integer argument of the add1 function...
-  Argument *ArgX = FibF->arg_begin();   // Get the arg.
+  Argument *ArgX = &*FibF->arg_begin(); // Get the arg.
   ArgX->setName("AnArg");            // Give it a nice symbolic name for fun.
 
   // Create the true_block.
@@ -87,7 +88,6 @@ static Function *CreateFibFunction(Module *M, LLVMContext &Context) {
   return FibF;
 }
 
-
 int main(int argc, char **argv) {
   int n = argc > 1 ? atol(argv[1]) : 24;
 
@@ -106,7 +106,6 @@ int main(int argc, char **argv) {
   ExecutionEngine *EE =
     EngineBuilder(std::move(Owner))
     .setErrorStr(&errStr)
-    .setEngineKind(EngineKind::JIT)
     .create();
 
   if (!EE) {
diff --git a/examples/HowToUseJIT/HowToUseJIT.cpp b/examples/HowToUseJIT/HowToUseJIT.cpp
index 91ea17dd22bf..e0bf6a00bf01 100644
--- a/examples/HowToUseJIT/HowToUseJIT.cpp
+++ b/examples/HowToUseJIT/HowToUseJIT.cpp
@@ -65,7 +65,7 @@ int main() {
   Function *Add1F =
     cast<Function>(M->getOrInsertFunction("add1", Type::getInt32Ty(Context),
                                           Type::getInt32Ty(Context),
-                                          (Type *)0));
+                                          nullptr));
 
   // Add a basic block to the function. As before, it automatically inserts
   // because of the last argument.
@@ -80,7 +80,7 @@ int main() {
 
   // Get pointers to the integer argument of the add1 function...
   assert(Add1F->arg_begin() != Add1F->arg_end()); // Make sure there's an arg
-  Argument *ArgX = Add1F->arg_begin();  // Get the arg
+  Argument *ArgX = &*Add1F->arg_begin();          // Get the arg
   ArgX->setName("AnArg");            // Give it a nice symbolic name for fun.
 
   // Create the add instruction, inserting it into the end of BB.
@@ -91,12 +91,11 @@ int main() {
 
   // Now, function add1 is ready.
 
-
   // Now we're going to create function `foo', which returns an int and takes no
   // arguments.
   Function *FooF =
     cast<Function>(M->getOrInsertFunction("foo", Type::getInt32Ty(Context),
-                                          (Type *)0));
+                                          nullptr));
 
   // Add a basic block to the FooF function.
   BB = BasicBlock::Create(Context, "EntryBlock", FooF);
diff --git a/examples/Kaleidoscope/Chapter2/CMakeLists.txt b/examples/Kaleidoscope/Chapter2/CMakeLists.txt
index fed3f4b78c77..6224d9ac8640 100644
--- a/examples/Kaleidoscope/Chapter2/CMakeLists.txt
+++ b/examples/Kaleidoscope/Chapter2/CMakeLists.txt
@@ -1,3 +1,9 @@
 add_kaleidoscope_chapter(Kaleidoscope-Ch2
   toy.cpp
   )
+
+if(LLVM_COMPILER_IS_GCC_COMPATIBLE)
+  target_compile_options(Kaleidoscope-Ch2 PRIVATE
+    -Wno-unused-private-field
+    )
+endif()
diff --git a/examples/Kaleidoscope/Chapter2/Makefile b/examples/Kaleidoscope/Chapter2/Makefile
index 1a9b94ce541e..fa27e6e06687 100644
--- a/examples/Kaleidoscope/Chapter2/Makefile
+++ b/examples/Kaleidoscope/Chapter2/Makefile
@@ -10,4 +10,6 @@ LEVEL = ../../..
 TOOLNAME = Kaleidoscope-Ch2
 EXAMPLE_TOOL = 1
 
+LLVM_CXXFLAGS := -Wno-unused-private-field
+
 include $(LEVEL)/Makefile.common
diff --git a/examples/Kaleidoscope/Chapter2/toy.cpp b/examples/Kaleidoscope/Chapter2/toy.cpp
index cd901394a524..69f359961293 100644
--- a/examples/Kaleidoscope/Chapter2/toy.cpp
+++ b/examples/Kaleidoscope/Chapter2/toy.cpp
@@ -1,10 +1,22 @@
 #include <cctype>
 #include <cstdio>
-#include <cstdlib>
 #include <map>
+#include <memory>
 #include <string>
 #include <vector>
 
+namespace helper {
+// Cloning make_unique here until it's standard in C++14.
+// Using a namespace to avoid conflicting with MSVC's std::make_unique (which
+// ADL can sometimes find in unqualified calls).
+template <class T, class... Args>
+static
+    typename std::enable_if<!std::is_array<T>::value, std::unique_ptr<T>>::type
+    make_unique(Args &&... args) {
+  return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
+}
+}
+
 //===----------------------------------------------------------------------===//
 // Lexer
 //===----------------------------------------------------------------------===//
@@ -15,14 +27,16 @@ 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() {
@@ -37,31 +51,34 @@ 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;
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
   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;
@@ -84,30 +101,40 @@ public:
 
 /// NumberExprAST - Expression class for numeric literals like "1.0".
 class NumberExprAST : public ExprAST {
+  double Val;
+
 public:
-  NumberExprAST(double val) {}
+  NumberExprAST(double Val) : Val(Val) {}
 };
 
 /// VariableExprAST - Expression class for referencing a variable, like "a".
 class VariableExprAST : public ExprAST {
   std::string Name;
+
 public:
-  VariableExprAST(const std::string &name) : Name(name) {}
+  VariableExprAST(const std::string &Name) : Name(Name) {}
 };
 
 /// BinaryExprAST - Expression class for a binary operator.
 class BinaryExprAST : public ExprAST {
+  char Op;
+  std::unique_ptr<ExprAST> LHS, RHS;
+
 public:
-  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) {}
+  BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
+                std::unique_ptr<ExprAST> RHS)
+      : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
 };
 
 /// CallExprAST - Expression class for function calls.
 class CallExprAST : public ExprAST {
   std::string Callee;
-  std::vector<ExprAST*> Args;
+  std::vector<std::unique_ptr<ExprAST>> Args;
+
 public:
-  CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
-    : Callee(callee), Args(args) {}
+  CallExprAST(const std::string &Callee,
+              std::vector<std::unique_ptr<ExprAST>> Args)
+      : Callee(Callee), Args(std::move(Args)) {}
 };
 
 /// PrototypeAST - This class represents the "prototype" for a function,
@@ -116,16 +143,21 @@ 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) {}
-  
+  PrototypeAST(const std::string &Name, std::vector<std::string> Args)
+      : Name(Name), Args(std::move(Args)) {}
 };
 
 /// FunctionAST - This class represents a function definition itself.
 class FunctionAST {
+  std::unique_ptr<PrototypeAST> Proto;
+  std::unique_ptr<ExprAST> Body;
+
 public:
-  FunctionAST(PrototypeAST *proto, ExprAST *body) {}
+  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
+              std::unique_ptr<ExprAST> Body)
+      : Proto(std::move(Proto)), Body(std::move(Body)) {}
 };
 } // end anonymous namespace
 
@@ -137,9 +169,7 @@ 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.
@@ -149,40 +179,69 @@ 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; }
+std::unique_ptr<ExprAST> Error(const char *Str) {
+  fprintf(stderr, "Error: %s\n", Str);
+  return nullptr;
+}
+std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
+  Error(Str);
+  return nullptr;
+}
+
+static std::unique_ptr<ExprAST> ParseExpression();
 
-static ExprAST *ParseExpression();
+/// numberexpr ::= number
+static std::unique_ptr<ExprAST> ParseNumberExpr() {
+  auto Result = helper::make_unique<NumberExprAST>(NumVal);
+  getNextToken(); // consume the number
+  return std::move(Result);
+}
+
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+  getNextToken(); // eat (.
+  auto V = ParseExpression();
+  if (!V)
+    return nullptr;
+
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken(); // eat ).
+  return V;
+}
 
 /// identifierexpr
 ///   ::= identifier
 ///   ::= identifier '(' expression* ')'
-static ExprAST *ParseIdentifierExpr() {
+static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
-  
-  getNextToken();  // eat identifier.
-  
+
+  getNextToken(); // eat identifier.
+
   if (CurTok != '(') // Simple variable ref.
-    return new VariableExprAST(IdName);
-  
+    return helper::make_unique<VariableExprAST>(IdName);
+
   // Call.
-  getNextToken();  // eat (
-  std::vector<ExprAST*> Args;
+  getNextToken(); // eat (
+  std::vector<std::unique_ptr<ExprAST>> Args;
   if (CurTok != ')') {
     while (1) {
-      ExprAST *Arg = ParseExpression();
-      if (!Arg) return 0;
-      Args.push_back(Arg);
+      if (auto Arg = ParseExpression())
+        Args.push_back(std::move(Arg));
+      else
+        return nullptr;
 
-      if (CurTok == ')') break;
+      if (CurTok == ')')
+        break;
 
       if (CurTok != ',')
         return Error("Expected ')' or ',' in argument list");
@@ -192,133 +251,125 @@ static ExprAST *ParseIdentifierExpr() {
 
   // Eat the ')'.
   getNextToken();
-  
-  return new CallExprAST(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;
+  return helper::make_unique<CallExprAST>(IdName, std::move(Args));
 }
 
 /// primary
 ///   ::= identifierexpr
 ///   ::= numberexpr
 ///   ::= parenexpr
-static ExprAST *ParsePrimary() {
+static std::unique_ptr<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();
   }
 }
 
 /// binoprhs
 ///   ::= ('+' primary)*
-static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+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
-    
+    getNextToken(); // eat binop
+
     // Parse the primary expression after the binary operator.
-    ExprAST *RHS = ParsePrimary();
-    if (!RHS) return 0;
-    
+    auto RHS = ParsePrimary();
+    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, RHS);
-      if (RHS == 0) return 0;
+      RHS = ParseBinOpRHS(TokPrec + 1, std::move(RHS));
+      if (!RHS)
+        return nullptr;
     }
-    
+
     // Merge LHS/RHS.
-    LHS = new BinaryExprAST(BinOp, LHS, RHS);
+    LHS = helper::make_unique<BinaryExprAST>(BinOp, std::move(LHS),
+                                             std::move(RHS));
   }
 }
 
 /// expression
 ///   ::= primary binoprhs
 ///
-static ExprAST *ParseExpression() {
-  ExprAST *LHS = ParsePrimary();
-  if (!LHS) return 0;
-  
-  return ParseBinOpRHS(0, LHS);
+static std::unique_ptr<ExprAST> ParseExpression() {
+  auto LHS = ParsePrimary();
+  if (!LHS)
+    return nullptr;
+
+  return ParseBinOpRHS(0, std::move(LHS));
 }
 
 /// prototype
 ///   ::= id '(' id* ')'
-static PrototypeAST *ParsePrototype() {
+static std::unique_ptr<PrototypeAST> ParsePrototype() {
   if (CurTok != tok_identifier)
     return ErrorP("Expected function name in prototype");
 
   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 ')'.
-  
-  return new PrototypeAST(FnName, ArgNames);
+  getNextToken(); // eat ')'.
+
+  return helper::make_unique<PrototypeAST>(FnName, std::move(ArgNames));
 }
 
 /// 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;
+static std::unique_ptr<FunctionAST> ParseDefinition() {
+  getNextToken(); // eat def.
+  auto Proto = ParsePrototype();
+  if (!Proto)
+    return nullptr;
+
+  if (auto E = ParseExpression())
+    return helper::make_unique<FunctionAST>(std::move(Proto), std::move(E));
+  return nullptr;
 }
 
 /// toplevelexpr ::= expression
-static FunctionAST *ParseTopLevelExpr() {
-  if (ExprAST *E = ParseExpression()) {
+static std::unique_ptr<FunctionAST> ParseTopLevelExpr() {
+  if (auto E = ParseExpression()) {
     // Make an anonymous proto.
-    PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
-    return new FunctionAST(Proto, E);
+    auto Proto = helper::make_unique<PrototypeAST>("__anon_expr",
+                                                   std::vector<std::string>());
+    return helper::make_unique<FunctionAST>(std::move(Proto), std::move(E));
   }
-  return 0;
+  return nullptr;
 }
 
 /// external ::= 'extern' prototype
-static PrototypeAST *ParseExtern() {
-  getNextToken();  // eat extern.
+static std::unique_ptr<PrototypeAST> ParseExtern() {
+  getNextToken(); // eat extern.
   return ParsePrototype();
 }
 
@@ -359,11 +410,20 @@ 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 ';': // ignore top-level semicolons.
+      getNextToken();
+      break;
+    case tok_def:
+      HandleDefinition();
+      break;
+    case tok_extern:
+      HandleExtern();
+      break;
+    default:
+      HandleTopLevelExpression();
+      break;
     }
   }
 }
@@ -378,7 +438,7 @@ int main() {
   BinopPrecedence['<'] = 10;
   BinopPrecedence['+'] = 20;
   BinopPrecedence['-'] = 20;
-  BinopPrecedence['*'] = 40;  // highest.
+  BinopPrecedence['*'] = 40; // highest.
 
   // Prime the first token.
   fprintf(stderr, "ready> ");
diff --git a/examples/Kaleidoscope/Chapter3/toy.cpp b/examples/Kaleidoscope/Chapter3/toy.cpp
index c60f76725fdb..05697ea70a49 100644
--- a/examples/Kaleidoscope/Chapter3/toy.cpp
+++ b/examples/Kaleidoscope/Chapter3/toy.cpp
@@ -1,13 +1,14 @@
-#include "llvm/IR/Verifier.h"
-#include "llvm/IR/DerivedTypes.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
+#include "llvm/IR/Verifier.h"
 #include <cctype>
 #include <cstdio>
 #include <map>
 #include <string>
 #include <vector>
+
 using namespace llvm;
 
 //===----------------------------------------------------------------------===//
@@ -20,14 +21,16 @@ 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() {
@@ -42,31 +45,34 @@ 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;
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
   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;
@@ -85,43 +91,49 @@ namespace {
 class ExprAST {
 public:
   virtual ~ExprAST() {}
-  virtual Value *Codegen() = 0;
+  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) {}
-  Value *Codegen() override;
+  NumberExprAST(double Val) : Val(Val) {}
+  Value *codegen() override;
 };
 
 /// VariableExprAST - Expression class for referencing a variable, like "a".
 class VariableExprAST : public ExprAST {
   std::string Name;
+
 public:
-  VariableExprAST(const std::string &name) : Name(name) {}
-  Value *Codegen() override;
+  VariableExprAST(const std::string &Name) : Name(Name) {}
+  Value *codegen() override;
 };
 
 /// BinaryExprAST - Expression class for a binary operator.
 class BinaryExprAST : public ExprAST {
   char Op;
-  ExprAST *LHS, *RHS;
+  std::unique_ptr<ExprAST> LHS, RHS;
+
 public:
-  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) 
-    : Op(op), LHS(lhs), RHS(rhs) {}
-  Value *Codegen() override;
+  BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
+                std::unique_ptr<ExprAST> RHS)
+      : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
+  Value *codegen() override;
 };
 
 /// CallExprAST - Expression class for function calls.
 class CallExprAST : public ExprAST {
   std::string Callee;
-  std::vector<ExprAST*> Args;
+  std::vector<std::unique_ptr<ExprAST>> Args;
+
 public:
-  CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
-    : Callee(callee), Args(args) {}
-  Value *Codegen() override;
+  CallExprAST(const std::string &Callee,
+              std::vector<std::unique_ptr<ExprAST>> Args)
+      : Callee(Callee), Args(std::move(Args)) {}
+  Value *codegen() override;
 };
 
 /// PrototypeAST - This class represents the "prototype" for a function,
@@ -130,22 +142,24 @@ 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) {}
-  
-  Function *Codegen();
+  PrototypeAST(const std::string &Name, std::vector<std::string> Args)
+      : Name(Name), Args(std::move(Args)) {}
+  Function *codegen();
+  const std::string &getName() const { return Name; }
 };
 
 /// FunctionAST - This class represents a function definition itself.
 class FunctionAST {
-  PrototypeAST *Proto;
-  ExprAST *Body;
+  std::unique_ptr<PrototypeAST> Proto;
+  std::unique_ptr<ExprAST> Body;
+
 public:
-  FunctionAST(PrototypeAST *proto, ExprAST *body)
-    : Proto(proto), Body(body) {}
-  
-  Function *Codegen();
+  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
+              std::unique_ptr<ExprAST> Body)
+      : Proto(std::move(Proto)), Body(std::move(Body)) {}
+  Function *codegen();
 };
 } // end anonymous namespace
 
@@ -157,9 +171,7 @@ 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.
@@ -169,41 +181,70 @@ 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; }
+std::unique_ptr<ExprAST> Error(const char *Str) {
+  fprintf(stderr, "Error: %s\n", Str);
+  return nullptr;
+}
+
+std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
+  Error(Str);
+  return nullptr;
+}
+
+static std::unique_ptr<ExprAST> ParseExpression();
+
+/// numberexpr ::= number
+static std::unique_ptr<ExprAST> ParseNumberExpr() {
+  auto Result = llvm::make_unique<NumberExprAST>(NumVal);
+  getNextToken(); // consume the number
+  return std::move(Result);
+}
 
-static ExprAST *ParseExpression();
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+  getNextToken(); // eat (.
+  auto V = ParseExpression();
+  if (!V)
+    return nullptr;
+
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken(); // eat ).
+  return V;
+}
 
 /// identifierexpr
 ///   ::= identifier
 ///   ::= identifier '(' expression* ')'
-static ExprAST *ParseIdentifierExpr() {
+static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
-  
-  getNextToken();  // eat identifier.
-  
+
+  getNextToken(); // eat identifier.
+
   if (CurTok != '(') // Simple variable ref.
-    return new VariableExprAST(IdName);
-  
+    return llvm::make_unique<VariableExprAST>(IdName);
+
   // Call.
-  getNextToken();  // eat (
-  std::vector<ExprAST*> Args;
+  getNextToken(); // eat (
+  std::vector<std::unique_ptr<ExprAST>> Args;
   if (CurTok != ')') {
     while (1) {
-      ExprAST *Arg = ParseExpression();
-      if (!Arg) return 0;
-      Args.push_back(Arg);
+      if (auto Arg = ParseExpression())
+        Args.push_back(std::move(Arg));
+      else
+        return nullptr;
 
-      if (CurTok == ')') break;
+      if (CurTok == ')')
+        break;
 
       if (CurTok != ',')
         return Error("Expected ')' or ',' in argument list");
@@ -213,133 +254,125 @@ static ExprAST *ParseIdentifierExpr() {
 
   // Eat the ')'.
   getNextToken();
-  
-  return new CallExprAST(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;
+  return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
 }
 
 /// primary
 ///   ::= identifierexpr
 ///   ::= numberexpr
 ///   ::= parenexpr
-static ExprAST *ParsePrimary() {
+static std::unique_ptr<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();
   }
 }
 
 /// binoprhs
 ///   ::= ('+' primary)*
-static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+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
-    
+    getNextToken(); // eat binop
+
     // Parse the primary expression after the binary operator.
-    ExprAST *RHS = ParsePrimary();
-    if (!RHS) return 0;
-    
+    auto RHS = ParsePrimary();
+    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, RHS);
-      if (RHS == 0) return 0;
+      RHS = ParseBinOpRHS(TokPrec + 1, std::move(RHS));
+      if (!RHS)
+        return nullptr;
     }
-    
+
     // Merge LHS/RHS.
-    LHS = new BinaryExprAST(BinOp, LHS, RHS);
+    LHS =
+        llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
   }
 }
 
 /// expression
 ///   ::= primary binoprhs
 ///
-static ExprAST *ParseExpression() {
-  ExprAST *LHS = ParsePrimary();
-  if (!LHS) return 0;
-  
-  return ParseBinOpRHS(0, LHS);
+static std::unique_ptr<ExprAST> ParseExpression() {
+  auto LHS = ParsePrimary();
+  if (!LHS)
+    return nullptr;
+
+  return ParseBinOpRHS(0, std::move(LHS));
 }
 
 /// prototype
 ///   ::= id '(' id* ')'
-static PrototypeAST *ParsePrototype() {
+static std::unique_ptr<PrototypeAST> ParsePrototype() {
   if (CurTok != tok_identifier)
     return ErrorP("Expected function name in prototype");
 
   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 ')'.
-  
-  return new PrototypeAST(FnName, ArgNames);
+  getNextToken(); // eat ')'.
+
+  return llvm::make_unique<PrototypeAST>(FnName, std::move(ArgNames));
 }
 
 /// 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;
+static std::unique_ptr<FunctionAST> ParseDefinition() {
+  getNextToken(); // eat def.
+  auto Proto = ParsePrototype();
+  if (!Proto)
+    return nullptr;
+
+  if (auto E = ParseExpression())
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
+  return nullptr;
 }
 
 /// toplevelexpr ::= expression
-static FunctionAST *ParseTopLevelExpr() {
-  if (ExprAST *E = ParseExpression()) {
+static std::unique_ptr<FunctionAST> ParseTopLevelExpr() {
+  if (auto E = ParseExpression()) {
     // Make an anonymous proto.
-    PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
-    return new FunctionAST(Proto, E);
+    auto Proto = llvm::make_unique<PrototypeAST>("__anon_expr",
+                                                 std::vector<std::string>());
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
   }
-  return 0;
+  return nullptr;
 }
 
 /// external ::= 'extern' prototype
-static PrototypeAST *ParseExtern() {
-  getNextToken();  // eat extern.
+static std::unique_ptr<PrototypeAST> ParseExtern() {
+  getNextToken(); // eat extern.
   return ParsePrototype();
 }
 
@@ -347,113 +380,108 @@ static PrototypeAST *ParseExtern() {
 // Code Generation
 //===----------------------------------------------------------------------===//
 
-static Module *TheModule;
+static std::unique_ptr<Module> TheModule;
 static IRBuilder<> Builder(getGlobalContext());
-static std::map<std::string, Value*> NamedValues;
+static std::map<std::string, Value *> NamedValues;
 
-Value *ErrorV(const char *Str) { Error(Str); return 0; }
+Value *ErrorV(const char *Str) {
+  Error(Str);
+  return nullptr;
+}
 
-Value *NumberExprAST::Codegen() {
+Value *NumberExprAST::codegen() {
   return ConstantFP::get(getGlobalContext(), APFloat(Val));
 }
 
-Value *VariableExprAST::Codegen() {
+Value *VariableExprAST::codegen() {
   // Look this variable up in the function.
   Value *V = NamedValues[Name];
-  return V ? V : ErrorV("Unknown variable name");
+  if (!V)
+    return ErrorV("Unknown variable name");
+  return V;
 }
 
-Value *BinaryExprAST::Codegen() {
-  Value *L = LHS->Codegen();
-  Value *R = RHS->Codegen();
-  if (L == 0 || R == 0) return 0;
-  
+Value *BinaryExprAST::codegen() {
+  Value *L = LHS->codegen();
+  Value *R = RHS->codegen();
+  if (!L || !R)
+    return nullptr;
+
   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() {
+Value *CallExprAST::codegen() {
   // Look up the name in the global module table.
   Function *CalleeF = TheModule->getFunction(Callee);
-  if (CalleeF == 0)
+  if (!CalleeF)
     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;
+    ArgsV.push_back(Args[i]->codegen());
+    if (!ArgsV.back())
+      return nullptr;
   }
-  
+
   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 }
 
-Function *PrototypeAST::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);
-  
-  // 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;
-    }
-  }
-  
+  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.get());
+
   // 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;
-  }
-  
+  for (auto &Arg : F->args())
+    Arg.setName(Args[Idx++]);
+
   return F;
 }
 
-Function *FunctionAST::Codegen() {
-  NamedValues.clear();
-  
-  Function *TheFunction = Proto->Codegen();
-  if (TheFunction == 0)
-    return 0;
-  
+Function *FunctionAST::codegen() {
+  // First, check for an existing function from a previous 'extern' declaration.
+  Function *TheFunction = TheModule->getFunction(Proto->getName());
+
+  if (!TheFunction)
+    TheFunction = Proto->codegen();
+
+  if (!TheFunction)
+    return nullptr;
+
   // Create a new basic block to start insertion into.
   BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
   Builder.SetInsertPoint(BB);
-  
-  if (Value *RetVal = Body->Codegen()) {
+
+  // Record the function arguments in the NamedValues map.
+  NamedValues.clear();
+  for (auto &Arg : TheFunction->args())
+    NamedValues[Arg.getName()] = &Arg;
+
+  if (Value *RetVal = Body->codegen()) {
     // Finish off the function.
     Builder.CreateRet(RetVal);
 
@@ -462,10 +490,10 @@ Function *FunctionAST::Codegen() {
 
     return TheFunction;
   }
-  
+
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
-  return 0;
+  return nullptr;
 }
 
 //===----------------------------------------------------------------------===//
@@ -473,10 +501,10 @@ Function *FunctionAST::Codegen() {
 //===----------------------------------------------------------------------===//
 
 static void HandleDefinition() {
-  if (FunctionAST *F = ParseDefinition()) {
-    if (Function *LF = F->Codegen()) {
+  if (auto FnAST = ParseDefinition()) {
+    if (auto *FnIR = FnAST->codegen()) {
       fprintf(stderr, "Read function definition:");
-      LF->dump();
+      FnIR->dump();
     }
   } else {
     // Skip token for error recovery.
@@ -485,10 +513,10 @@ static void HandleDefinition() {
 }
 
 static void HandleExtern() {
-  if (PrototypeAST *P = ParseExtern()) {
-    if (Function *F = P->Codegen()) {
+  if (auto ProtoAST = ParseExtern()) {
+    if (auto *FnIR = ProtoAST->codegen()) {
       fprintf(stderr, "Read extern: ");
-      F->dump();
+      FnIR->dump();
     }
   } else {
     // Skip token for error recovery.
@@ -498,10 +526,10 @@ static void HandleExtern() {
 
 static void HandleTopLevelExpression() {
   // Evaluate a top-level expression into an anonymous function.
-  if (FunctionAST *F = ParseTopLevelExpr()) {
-    if (Function *LF = F->Codegen()) {
+  if (auto FnAST = ParseTopLevelExpr()) {
+    if (auto *FnIR = FnAST->codegen()) {
       fprintf(stderr, "Read top-level expression:");
-      LF->dump();
+      FnIR->dump();
     }
   } else {
     // Skip token for error recovery.
@@ -514,46 +542,42 @@ 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 ';': // ignore top-level semicolons.
+      getNextToken();
+      break;
+    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;
-}
-
-//===----------------------------------------------------------------------===//
 // Main driver code.
 //===----------------------------------------------------------------------===//
 
 int main() {
-  LLVMContext &Context = getGlobalContext();
-
   // 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.
-  TheModule = new Module("my cool jit", Context);
+  TheModule = llvm::make_unique<Module>("my cool jit", getGlobalContext());
 
   // Run the main "interpreter loop" now.
   MainLoop();
diff --git a/examples/Kaleidoscope/Chapter4/CMakeLists.txt b/examples/Kaleidoscope/Chapter4/CMakeLists.txt
index 2c01e120070a..89feed143adc 100644
--- a/examples/Kaleidoscope/Chapter4/CMakeLists.txt
+++ b/examples/Kaleidoscope/Chapter4/CMakeLists.txt
@@ -3,14 +3,15 @@ set(LLVM_LINK_COMPONENTS
   Core
   ExecutionEngine
   InstCombine
-  MCJIT
+  Object
   RuntimeDyld
   ScalarOpts
   Support
-  TransformUtils
   native
   )
 
 add_kaleidoscope_chapter(Kaleidoscope-Ch4
   toy.cpp
   )
+
+export_executable_symbols(Kaleidoscope-Ch4)
diff --git a/examples/Kaleidoscope/Chapter4/toy.cpp b/examples/Kaleidoscope/Chapter4/toy.cpp
index ad091e4496b7..4f77ec862b1b 100644
--- a/examples/Kaleidoscope/Chapter4/toy.cpp
+++ b/examples/Kaleidoscope/Chapter4/toy.cpp
@@ -1,9 +1,5 @@
+#include "llvm/ADT/STLExtras.h"
 #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"
@@ -16,7 +12,10 @@
 #include <map>
 #include <string>
 #include <vector>
+#include "../include/KaleidoscopeJIT.h"
+
 using namespace llvm;
+using namespace llvm::orc;
 
 //===----------------------------------------------------------------------===//
 // Lexer
@@ -66,7 +65,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -98,7 +97,7 @@ namespace {
 class ExprAST {
 public:
   virtual ~ExprAST() {}
-  virtual Value *Codegen() = 0;
+  virtual Value *codegen() = 0;
 };
 
 /// NumberExprAST - Expression class for numeric literals like "1.0".
@@ -106,8 +105,8 @@ class NumberExprAST : public ExprAST {
   double Val;
 
 public:
-  NumberExprAST(double val) : Val(val) {}
-  Value *Codegen() override;
+  NumberExprAST(double Val) : Val(Val) {}
+  Value *codegen() override;
 };
 
 /// VariableExprAST - Expression class for referencing a variable, like "a".
@@ -115,30 +114,32 @@ class VariableExprAST : public ExprAST {
   std::string Name;
 
 public:
-  VariableExprAST(const std::string &name) : Name(name) {}
-  Value *Codegen() override;
+  VariableExprAST(const std::string &Name) : Name(Name) {}
+  Value *codegen() override;
 };
 
 /// BinaryExprAST - Expression class for a binary operator.
 class BinaryExprAST : public ExprAST {
   char Op;
-  ExprAST *LHS, *RHS;
+  std::unique_ptr<ExprAST> LHS, RHS;
 
 public:
-  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
-      : Op(op), LHS(lhs), RHS(rhs) {}
-  Value *Codegen() override;
+  BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
+                std::unique_ptr<ExprAST> RHS)
+      : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
+  Value *codegen() override;
 };
 
 /// CallExprAST - Expression class for function calls.
 class CallExprAST : public ExprAST {
   std::string Callee;
-  std::vector<ExprAST *> Args;
+  std::vector<std::unique_ptr<ExprAST>> Args;
 
 public:
-  CallExprAST(const std::string &callee, std::vector<ExprAST *> &args)
-      : Callee(callee), Args(args) {}
-  Value *Codegen() override;
+  CallExprAST(const std::string &Callee,
+              std::vector<std::unique_ptr<ExprAST>> Args)
+      : Callee(Callee), Args(std::move(Args)) {}
+  Value *codegen() override;
 };
 
 /// PrototypeAST - This class represents the "prototype" for a function,
@@ -149,21 +150,22 @@ class PrototypeAST {
   std::vector<std::string> Args;
 
 public:
-  PrototypeAST(const std::string &name, const std::vector<std::string> &args)
-      : Name(name), Args(args) {}
-
-  Function *Codegen();
+  PrototypeAST(const std::string &Name, std::vector<std::string> Args)
+      : Name(Name), Args(std::move(Args)) {}
+  Function *codegen();
+  const std::string &getName() const { return Name; }
 };
 
 /// FunctionAST - This class represents a function definition itself.
 class FunctionAST {
-  PrototypeAST *Proto;
-  ExprAST *Body;
+  std::unique_ptr<PrototypeAST> Proto;
+  std::unique_ptr<ExprAST> Body;
 
 public:
-  FunctionAST(PrototypeAST *proto, ExprAST *body) : Proto(proto), Body(body) {}
-
-  Function *Codegen();
+  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
+              std::unique_ptr<ExprAST> Body)
+      : Proto(std::move(Proto)), Body(std::move(Body)) {}
+  Function *codegen();
 };
 } // end anonymous namespace
 
@@ -194,41 +196,58 @@ static int GetTokPrecedence() {
 }
 
 /// Error* - These are little helper functions for error handling.
-ExprAST *Error(const char *Str) {
+std::unique_ptr<ExprAST> Error(const char *Str) {
   fprintf(stderr, "Error: %s\n", Str);
-  return 0;
+  return nullptr;
 }
-PrototypeAST *ErrorP(const char *Str) {
+
+std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
   Error(Str);
-  return 0;
+  return nullptr;
 }
-FunctionAST *ErrorF(const char *Str) {
-  Error(Str);
-  return 0;
+
+static std::unique_ptr<ExprAST> ParseExpression();
+
+/// numberexpr ::= number
+static std::unique_ptr<ExprAST> ParseNumberExpr() {
+  auto Result = llvm::make_unique<NumberExprAST>(NumVal);
+  getNextToken(); // consume the number
+  return std::move(Result);
 }
 
-static ExprAST *ParseExpression();
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+  getNextToken(); // eat (.
+  auto V = ParseExpression();
+  if (!V)
+    return nullptr;
+
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken(); // eat ).
+  return V;
+}
 
 /// identifierexpr
 ///   ::= identifier
 ///   ::= identifier '(' expression* ')'
-static ExprAST *ParseIdentifierExpr() {
+static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
 
   getNextToken(); // eat identifier.
 
   if (CurTok != '(') // Simple variable ref.
-    return new VariableExprAST(IdName);
+    return llvm::make_unique<VariableExprAST>(IdName);
 
   // Call.
   getNextToken(); // eat (
-  std::vector<ExprAST *> Args;
+  std::vector<std::unique_ptr<ExprAST>> Args;
   if (CurTok != ')') {
     while (1) {
-      ExprAST *Arg = ParseExpression();
-      if (!Arg)
-        return 0;
-      Args.push_back(Arg);
+      if (auto Arg = ParseExpression())
+        Args.push_back(std::move(Arg));
+      else
+        return nullptr;
 
       if (CurTok == ')')
         break;
@@ -242,34 +261,14 @@ static ExprAST *ParseIdentifierExpr() {
   // Eat the ')'.
   getNextToken();
 
-  return new CallExprAST(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;
+  return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
 }
 
 /// primary
 ///   ::= identifierexpr
 ///   ::= numberexpr
 ///   ::= parenexpr
-static ExprAST *ParsePrimary() {
+static std::unique_ptr<ExprAST> ParsePrimary() {
   switch (CurTok) {
   default:
     return Error("unknown token when expecting an expression");
@@ -284,7 +283,8 @@ static ExprAST *ParsePrimary() {
 
 /// binoprhs
 ///   ::= ('+' primary)*
-static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+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();
@@ -299,38 +299,39 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
     getNextToken(); // eat binop
 
     // Parse the primary expression after the binary operator.
-    ExprAST *RHS = ParsePrimary();
+    auto RHS = ParsePrimary();
     if (!RHS)
-      return 0;
+      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, RHS);
-      if (RHS == 0)
-        return 0;
+      RHS = ParseBinOpRHS(TokPrec + 1, std::move(RHS));
+      if (!RHS)
+        return nullptr;
     }
 
     // Merge LHS/RHS.
-    LHS = new BinaryExprAST(BinOp, LHS, RHS);
+    LHS =
+        llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
   }
 }
 
 /// expression
 ///   ::= primary binoprhs
 ///
-static ExprAST *ParseExpression() {
-  ExprAST *LHS = ParsePrimary();
+static std::unique_ptr<ExprAST> ParseExpression() {
+  auto LHS = ParsePrimary();
   if (!LHS)
-    return 0;
+    return nullptr;
 
-  return ParseBinOpRHS(0, LHS);
+  return ParseBinOpRHS(0, std::move(LHS));
 }
 
 /// prototype
 ///   ::= id '(' id* ')'
-static PrototypeAST *ParsePrototype() {
+static std::unique_ptr<PrototypeAST> ParsePrototype() {
   if (CurTok != tok_identifier)
     return ErrorP("Expected function name in prototype");
 
@@ -349,300 +350,86 @@ static PrototypeAST *ParsePrototype() {
   // success.
   getNextToken(); // eat ')'.
 
-  return new PrototypeAST(FnName, ArgNames);
+  return llvm::make_unique<PrototypeAST>(FnName, std::move(ArgNames));
 }
 
 /// definition ::= 'def' prototype expression
-static FunctionAST *ParseDefinition() {
+static std::unique_ptr<FunctionAST> ParseDefinition() {
   getNextToken(); // eat def.
-  PrototypeAST *Proto = ParsePrototype();
-  if (Proto == 0)
-    return 0;
+  auto Proto = ParsePrototype();
+  if (!Proto)
+    return nullptr;
 
-  if (ExprAST *E = ParseExpression())
-    return new FunctionAST(Proto, E);
-  return 0;
+  if (auto E = ParseExpression())
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
+  return nullptr;
 }
 
 /// toplevelexpr ::= expression
-static FunctionAST *ParseTopLevelExpr() {
-  if (ExprAST *E = ParseExpression()) {
+static std::unique_ptr<FunctionAST> ParseTopLevelExpr() {
+  if (auto E = ParseExpression()) {
     // Make an anonymous proto.
-    PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
-    return new FunctionAST(Proto, E);
+    auto Proto = llvm::make_unique<PrototypeAST>("__anon_expr",
+                                                 std::vector<std::string>());
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
   }
-  return 0;
+  return nullptr;
 }
 
 /// external ::= 'extern' prototype
-static PrototypeAST *ParseExtern() {
+static std::unique_ptr<PrototypeAST> ParseExtern() {
   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) {}
-  ~HelpingMemoryManager() override {}
-
-  /// 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.
-  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());
-    // 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 MCJITHelper *JITHelper;
+static std::unique_ptr<Module> TheModule;
 static IRBuilder<> Builder(getGlobalContext());
 static std::map<std::string, Value *> NamedValues;
+static std::unique_ptr<legacy::FunctionPassManager> TheFPM;
+static std::unique_ptr<KaleidoscopeJIT> TheJIT;
+static std::map<std::string, std::unique_ptr<PrototypeAST>> FunctionProtos;
 
 Value *ErrorV(const char *Str) {
   Error(Str);
-  return 0;
+  return nullptr;
+}
+
+Function *getFunction(std::string Name) {
+  // First, see if the function has already been added to the current module.
+  if (auto *F = TheModule->getFunction(Name))
+    return F;
+
+  // If not, check whether we can codegen the declaration from some existing
+  // prototype.
+  auto FI = FunctionProtos.find(Name);
+  if (FI != FunctionProtos.end())
+    return FI->second->codegen();
+
+  // If no existing prototype exists, return null.
+  return nullptr;
 }
 
-Value *NumberExprAST::Codegen() {
+Value *NumberExprAST::codegen() {
   return ConstantFP::get(getGlobalContext(), APFloat(Val));
 }
 
-Value *VariableExprAST::Codegen() {
+Value *VariableExprAST::codegen() {
   // Look this variable up in the function.
   Value *V = NamedValues[Name];
-  return V ? V : ErrorV("Unknown variable name");
+  if (!V)
+    return ErrorV("Unknown variable name");
+  return V;
 }
 
-Value *BinaryExprAST::Codegen() {
-  Value *L = LHS->Codegen();
-  Value *R = RHS->Codegen();
-  if (L == 0 || R == 0)
-    return 0;
+Value *BinaryExprAST::codegen() {
+  Value *L = LHS->codegen();
+  Value *R = RHS->codegen();
+  if (!L || !R)
+    return nullptr;
 
   switch (Op) {
   case '+':
@@ -661,10 +448,10 @@ Value *BinaryExprAST::Codegen() {
   }
 }
 
-Value *CallExprAST::Codegen() {
+Value *CallExprAST::codegen() {
   // Look up the name in the global module table.
-  Function *CalleeF = JITHelper->getFunction(Callee);
-  if (CalleeF == 0)
+  Function *CalleeF = getFunction(Callee);
+  if (!CalleeF)
     return ErrorV("Unknown function referenced");
 
   // If argument mismatch error.
@@ -673,94 +460,99 @@ Value *CallExprAST::Codegen() {
 
   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;
+    ArgsV.push_back(Args[i]->codegen());
+    if (!ArgsV.back())
+      return nullptr;
   }
 
   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 }
 
-Function *PrototypeAST::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);
 
-  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() != FnName) {
-    // Delete the one we just made and get the existing one.
-    F->eraseFromParent();
-    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;
-    }
-  }
+  Function *F =
+      Function::Create(FT, Function::ExternalLinkage, Name, TheModule.get());
 
   // 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;
-  }
+  for (auto &Arg : F->args())
+    Arg.setName(Args[Idx++]);
 
   return F;
 }
 
-Function *FunctionAST::Codegen() {
-  NamedValues.clear();
-
-  Function *TheFunction = Proto->Codegen();
-  if (TheFunction == 0)
-    return 0;
+Function *FunctionAST::codegen() {
+  // Transfer ownership of the prototype to the FunctionProtos map, but keep a
+  // reference to it for use below.
+  auto &P = *Proto;
+  FunctionProtos[Proto->getName()] = std::move(Proto);
+  Function *TheFunction = getFunction(P.getName());
+  if (!TheFunction)
+    return nullptr;
 
   // Create a new basic block to start insertion into.
   BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
   Builder.SetInsertPoint(BB);
 
-  if (Value *RetVal = Body->Codegen()) {
+  // Record the function arguments in the NamedValues map.
+  NamedValues.clear();
+  for (auto &Arg : TheFunction->args())
+    NamedValues[Arg.getName()] = &Arg;
+
+  if (Value *RetVal = Body->codegen()) {
     // Finish off the function.
     Builder.CreateRet(RetVal);
 
     // Validate the generated code, checking for consistency.
     verifyFunction(*TheFunction);
 
+    // Run the optimizer on the function.
+    TheFPM->run(*TheFunction);
+
     return TheFunction;
   }
 
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
-  return 0;
+  return nullptr;
 }
 
 //===----------------------------------------------------------------------===//
 // Top-Level parsing and JIT Driver
 //===----------------------------------------------------------------------===//
 
+static void InitializeModuleAndPassManager() {
+  // Open a new module.
+  TheModule = llvm::make_unique<Module>("my cool jit", getGlobalContext());
+  TheModule->setDataLayout(TheJIT->getTargetMachine().createDataLayout());
+
+  // Create a new pass manager attached to it.
+  TheFPM = llvm::make_unique<legacy::FunctionPassManager>(TheModule.get());
+
+  // Do simple "peephole" optimizations and bit-twiddling optzns.
+  TheFPM->add(createInstructionCombiningPass());
+  // Reassociate expressions.
+  TheFPM->add(createReassociatePass());
+  // Eliminate Common SubExpressions.
+  TheFPM->add(createGVNPass());
+  // Simplify the control flow graph (deleting unreachable blocks, etc).
+  TheFPM->add(createCFGSimplificationPass());
+
+  TheFPM->doInitialization();
+}
+
 static void HandleDefinition() {
-  if (FunctionAST *F = ParseDefinition()) {
-    if (Function *LF = F->Codegen()) {
+  if (auto FnAST = ParseDefinition()) {
+    if (auto *FnIR = FnAST->codegen()) {
       fprintf(stderr, "Read function definition:");
-      LF->dump();
+      FnIR->dump();
+      TheJIT->addModule(std::move(TheModule));
+      InitializeModuleAndPassManager();
     }
   } else {
     // Skip token for error recovery.
@@ -769,10 +561,11 @@ static void HandleDefinition() {
 }
 
 static void HandleExtern() {
-  if (PrototypeAST *P = ParseExtern()) {
-    if (Function *F = P->Codegen()) {
+  if (auto ProtoAST = ParseExtern()) {
+    if (auto *FnIR = ProtoAST->codegen()) {
       fprintf(stderr, "Read extern: ");
-      F->dump();
+      FnIR->dump();
+      FunctionProtos[ProtoAST->getName()] = std::move(ProtoAST);
     }
   } else {
     // Skip token for error recovery.
@@ -782,15 +575,25 @@ static void HandleExtern() {
 
 static void HandleTopLevelExpression() {
   // Evaluate a top-level expression into an anonymous function.
-  if (FunctionAST *F = ParseTopLevelExpr()) {
-    if (Function *LF = F->Codegen()) {
-      // JIT the function, returning a function pointer.
-      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;
+  if (auto FnAST = ParseTopLevelExpr()) {
+    if (FnAST->codegen()) {
+
+      // JIT the module containing the anonymous expression, keeping a handle so
+      // we can free it later.
+      auto H = TheJIT->addModule(std::move(TheModule));
+      InitializeModuleAndPassManager();
+
+      // Search the JIT for the __anon_expr symbol.
+      auto ExprSymbol = TheJIT->findSymbol("__anon_expr");
+      assert(ExprSymbol && "Function not found");
+
+      // Get the symbol's address and 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();
       fprintf(stderr, "Evaluated to %f\n", FP());
+
+      // Delete the anonymous expression module from the JIT.
+      TheJIT->removeModule(H);
     }
   } else {
     // Skip token for error recovery.
@@ -805,9 +608,9 @@ static void MainLoop() {
     switch (CurTok) {
     case tok_eof:
       return;
-    case ';':
+    case ';': // ignore top-level semicolons.
       getNextToken();
-      break; // ignore top-level semicolons.
+      break;
     case tok_def:
       HandleDefinition();
       break;
@@ -827,7 +630,13 @@ static void MainLoop() {
 
 /// putchard - putchar that takes a double and returns 0.
 extern "C" double putchard(double X) {
-  putchar((char)X);
+  fputc((char)X, stderr);
+  return 0;
+}
+
+/// printd - printf that takes a double prints it as "%f\n", returning 0.
+extern "C" double printd(double X) {
+  fprintf(stderr, "%f\n", X);
   return 0;
 }
 
@@ -839,8 +648,6 @@ int main() {
   InitializeNativeTarget();
   InitializeNativeTargetAsmPrinter();
   InitializeNativeTargetAsmParser();
-  LLVMContext &Context = getGlobalContext();
-  JITHelper = new MCJITHelper(Context);
 
   // Install standard binary operators.
   // 1 is lowest precedence.
@@ -853,11 +660,12 @@ int main() {
   fprintf(stderr, "ready> ");
   getNextToken();
 
+  TheJIT = llvm::make_unique<KaleidoscopeJIT>();
+
+  InitializeModuleAndPassManager();
+
   // Run the main "interpreter loop" now.
   MainLoop();
 
-  // Print out all of the generated code.
-  JITHelper->dump();
-
   return 0;
 }
diff --git a/examples/Kaleidoscope/Chapter5/CMakeLists.txt b/examples/Kaleidoscope/Chapter5/CMakeLists.txt
index a938d9731fe8..c0ae70654c36 100644
--- a/examples/Kaleidoscope/Chapter5/CMakeLists.txt
+++ b/examples/Kaleidoscope/Chapter5/CMakeLists.txt
@@ -3,7 +3,7 @@ set(LLVM_LINK_COMPONENTS
   Core
   ExecutionEngine
   InstCombine
-  MCJIT
+  Object
   RuntimeDyld
   ScalarOpts
   Support
@@ -13,3 +13,5 @@ set(LLVM_LINK_COMPONENTS
 add_kaleidoscope_chapter(Kaleidoscope-Ch5
   toy.cpp
   )
+
+export_executable_symbols(Kaleidoscope-Ch5)
diff --git a/examples/Kaleidoscope/Chapter5/toy.cpp b/examples/Kaleidoscope/Chapter5/toy.cpp
index db9904895739..eeca4775eeb1 100644
--- a/examples/Kaleidoscope/Chapter5/toy.cpp
+++ b/examples/Kaleidoscope/Chapter5/toy.cpp
@@ -1,10 +1,5 @@
 #include "llvm/ADT/STLExtras.h"
 #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"
@@ -17,7 +12,10 @@
 #include <map>
 #include <string>
 #include <vector>
+#include "../include/KaleidoscopeJIT.h"
+
 using namespace llvm;
+using namespace llvm::orc;
 
 //===----------------------------------------------------------------------===//
 // Lexer
@@ -84,7 +82,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -116,7 +114,7 @@ namespace {
 class ExprAST {
 public:
   virtual ~ExprAST() {}
-  virtual Value *Codegen() = 0;
+  virtual Value *codegen() = 0;
 };
 
 /// NumberExprAST - Expression class for numeric literals like "1.0".
@@ -124,8 +122,8 @@ class NumberExprAST : public ExprAST {
   double Val;
 
 public:
-  NumberExprAST(double val) : Val(val) {}
-  Value *Codegen() override;
+  NumberExprAST(double Val) : Val(Val) {}
+  Value *codegen() override;
 };
 
 /// VariableExprAST - Expression class for referencing a variable, like "a".
@@ -133,52 +131,57 @@ class VariableExprAST : public ExprAST {
   std::string Name;
 
 public:
-  VariableExprAST(const std::string &name) : Name(name) {}
-  Value *Codegen() override;
+  VariableExprAST(const std::string &Name) : Name(Name) {}
+  Value *codegen() override;
 };
 
 /// BinaryExprAST - Expression class for a binary operator.
 class BinaryExprAST : public ExprAST {
   char Op;
-  ExprAST *LHS, *RHS;
+  std::unique_ptr<ExprAST> LHS, RHS;
 
 public:
-  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
-      : Op(op), LHS(lhs), RHS(rhs) {}
-  Value *Codegen() override;
+  BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
+                std::unique_ptr<ExprAST> RHS)
+      : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
+  Value *codegen() override;
 };
 
 /// CallExprAST - Expression class for function calls.
 class CallExprAST : public ExprAST {
   std::string Callee;
-  std::vector<ExprAST *> Args;
+  std::vector<std::unique_ptr<ExprAST>> Args;
 
 public:
-  CallExprAST(const std::string &callee, std::vector<ExprAST *> &args)
-      : Callee(callee), Args(args) {}
-  Value *Codegen() override;
+  CallExprAST(const std::string &Callee,
+              std::vector<std::unique_ptr<ExprAST>> Args)
+      : Callee(Callee), Args(std::move(Args)) {}
+  Value *codegen() override;
 };
 
 /// IfExprAST - Expression class for if/then/else.
 class IfExprAST : public ExprAST {
-  ExprAST *Cond, *Then, *Else;
+  std::unique_ptr<ExprAST> Cond, Then, Else;
 
 public:
-  IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
-      : Cond(cond), Then(then), Else(_else) {}
-  Value *Codegen() override;
+  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 *codegen() override;
 };
 
 /// ForExprAST - Expression class for for/in.
 class ForExprAST : public ExprAST {
   std::string VarName;
-  ExprAST *Start, *End, *Step, *Body;
+  std::unique_ptr<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) {}
-  Value *Codegen() override;
+  ForExprAST(const std::string &VarName, std::unique_ptr<ExprAST> Start,
+             std::unique_ptr<ExprAST> End, std::unique_ptr<ExprAST> Step,
+             std::unique_ptr<ExprAST> Body)
+      : VarName(VarName), Start(std::move(Start)), End(std::move(End)),
+        Step(std::move(Step)), Body(std::move(Body)) {}
+  Value *codegen() override;
 };
 
 /// PrototypeAST - This class represents the "prototype" for a function,
@@ -189,21 +192,22 @@ class PrototypeAST {
   std::vector<std::string> Args;
 
 public:
-  PrototypeAST(const std::string &name, const std::vector<std::string> &args)
-      : Name(name), Args(args) {}
-
-  Function *Codegen();
+  PrototypeAST(const std::string &Name, std::vector<std::string> Args)
+      : Name(Name), Args(std::move(Args)) {}
+  Function *codegen();
+  const std::string &getName() const { return Name; }
 };
 
 /// FunctionAST - This class represents a function definition itself.
 class FunctionAST {
-  PrototypeAST *Proto;
-  ExprAST *Body;
+  std::unique_ptr<PrototypeAST> Proto;
+  std::unique_ptr<ExprAST> Body;
 
 public:
-  FunctionAST(PrototypeAST *proto, ExprAST *body) : Proto(proto), Body(body) {}
-
-  Function *Codegen();
+  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
+              std::unique_ptr<ExprAST> Body)
+      : Proto(std::move(Proto)), Body(std::move(Body)) {}
+  Function *codegen();
 };
 } // end anonymous namespace
 
@@ -234,41 +238,58 @@ static int GetTokPrecedence() {
 }
 
 /// Error* - These are little helper functions for error handling.
-ExprAST *Error(const char *Str) {
+std::unique_ptr<ExprAST> Error(const char *Str) {
   fprintf(stderr, "Error: %s\n", Str);
-  return 0;
+  return nullptr;
 }
-PrototypeAST *ErrorP(const char *Str) {
+
+std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
   Error(Str);
-  return 0;
+  return nullptr;
 }
-FunctionAST *ErrorF(const char *Str) {
-  Error(Str);
-  return 0;
+
+static std::unique_ptr<ExprAST> ParseExpression();
+
+/// numberexpr ::= number
+static std::unique_ptr<ExprAST> ParseNumberExpr() {
+  auto Result = llvm::make_unique<NumberExprAST>(NumVal);
+  getNextToken(); // consume the number
+  return std::move(Result);
 }
 
-static ExprAST *ParseExpression();
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+  getNextToken(); // eat (.
+  auto V = ParseExpression();
+  if (!V)
+    return nullptr;
+
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken(); // eat ).
+  return V;
+}
 
 /// identifierexpr
 ///   ::= identifier
 ///   ::= identifier '(' expression* ')'
-static ExprAST *ParseIdentifierExpr() {
+static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
 
   getNextToken(); // eat identifier.
 
   if (CurTok != '(') // Simple variable ref.
-    return new VariableExprAST(IdName);
+    return llvm::make_unique<VariableExprAST>(IdName);
 
   // Call.
   getNextToken(); // eat (
-  std::vector<ExprAST *> Args;
+  std::vector<std::unique_ptr<ExprAST>> Args;
   if (CurTok != ')') {
     while (1) {
-      ExprAST *Arg = ParseExpression();
-      if (!Arg)
-        return 0;
-      Args.push_back(Arg);
+      if (auto Arg = ParseExpression())
+        Args.push_back(std::move(Arg));
+      else
+        return nullptr;
 
       if (CurTok == ')')
         break;
@@ -282,60 +303,41 @@ static ExprAST *ParseIdentifierExpr() {
   // Eat the ')'.
   getNextToken();
 
-  return new CallExprAST(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;
+  return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
 }
 
 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
-static ExprAST *ParseIfExpr() {
+static std::unique_ptr<ExprAST> ParseIfExpr() {
   getNextToken(); // eat the if.
 
   // condition.
-  ExprAST *Cond = ParseExpression();
+  auto Cond = ParseExpression();
   if (!Cond)
-    return 0;
+    return nullptr;
 
   if (CurTok != tok_then)
     return Error("expected then");
   getNextToken(); // eat the then
 
-  ExprAST *Then = ParseExpression();
-  if (Then == 0)
-    return 0;
+  auto Then = ParseExpression();
+  if (!Then)
+    return nullptr;
 
   if (CurTok != tok_else)
     return Error("expected else");
 
   getNextToken();
 
-  ExprAST *Else = ParseExpression();
+  auto Else = ParseExpression();
   if (!Else)
-    return 0;
+    return nullptr;
 
-  return new IfExprAST(Cond, Then, Else);
+  return llvm::make_unique<IfExprAST>(std::move(Cond), std::move(Then),
+                                      std::move(Else));
 }
 
 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
-static ExprAST *ParseForExpr() {
+static std::unique_ptr<ExprAST> ParseForExpr() {
   getNextToken(); // eat the for.
 
   if (CurTok != tok_identifier)
@@ -348,35 +350,36 @@ static ExprAST *ParseForExpr() {
     return Error("expected '=' after for");
   getNextToken(); // eat '='.
 
-  ExprAST *Start = ParseExpression();
-  if (Start == 0)
-    return 0;
+  auto Start = ParseExpression();
+  if (!Start)
+    return nullptr;
   if (CurTok != ',')
     return Error("expected ',' after for start value");
   getNextToken();
 
-  ExprAST *End = ParseExpression();
-  if (End == 0)
-    return 0;
+  auto End = ParseExpression();
+  if (!End)
+    return nullptr;
 
   // The step value is optional.
-  ExprAST *Step = 0;
+  std::unique_ptr<ExprAST> Step;
   if (CurTok == ',') {
     getNextToken();
     Step = ParseExpression();
-    if (Step == 0)
-      return 0;
+    if (!Step)
+      return nullptr;
   }
 
   if (CurTok != tok_in)
     return Error("expected 'in' after for");
   getNextToken(); // eat 'in'.
 
-  ExprAST *Body = ParseExpression();
-  if (Body == 0)
-    return 0;
+  auto Body = ParseExpression();
+  if (!Body)
+    return nullptr;
 
-  return new ForExprAST(IdName, Start, End, Step, Body);
+  return llvm::make_unique<ForExprAST>(IdName, std::move(Start), std::move(End),
+                                       std::move(Step), std::move(Body));
 }
 
 /// primary
@@ -385,7 +388,7 @@ static ExprAST *ParseForExpr() {
 ///   ::= parenexpr
 ///   ::= ifexpr
 ///   ::= forexpr
-static ExprAST *ParsePrimary() {
+static std::unique_ptr<ExprAST> ParsePrimary() {
   switch (CurTok) {
   default:
     return Error("unknown token when expecting an expression");
@@ -404,7 +407,8 @@ static ExprAST *ParsePrimary() {
 
 /// binoprhs
 ///   ::= ('+' primary)*
-static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+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();
@@ -419,38 +423,39 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
     getNextToken(); // eat binop
 
     // Parse the primary expression after the binary operator.
-    ExprAST *RHS = ParsePrimary();
+    auto RHS = ParsePrimary();
     if (!RHS)
-      return 0;
+      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, RHS);
-      if (RHS == 0)
-        return 0;
+      RHS = ParseBinOpRHS(TokPrec + 1, std::move(RHS));
+      if (!RHS)
+        return nullptr;
     }
 
     // Merge LHS/RHS.
-    LHS = new BinaryExprAST(BinOp, LHS, RHS);
+    LHS =
+        llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
   }
 }
 
 /// expression
 ///   ::= primary binoprhs
 ///
-static ExprAST *ParseExpression() {
-  ExprAST *LHS = ParsePrimary();
+static std::unique_ptr<ExprAST> ParseExpression() {
+  auto LHS = ParsePrimary();
   if (!LHS)
-    return 0;
+    return nullptr;
 
-  return ParseBinOpRHS(0, LHS);
+  return ParseBinOpRHS(0, std::move(LHS));
 }
 
 /// prototype
 ///   ::= id '(' id* ')'
-static PrototypeAST *ParsePrototype() {
+static std::unique_ptr<PrototypeAST> ParsePrototype() {
   if (CurTok != tok_identifier)
     return ErrorP("Expected function name in prototype");
 
@@ -469,33 +474,34 @@ static PrototypeAST *ParsePrototype() {
   // success.
   getNextToken(); // eat ')'.
 
-  return new PrototypeAST(FnName, ArgNames);
+  return llvm::make_unique<PrototypeAST>(FnName, std::move(ArgNames));
 }
 
 /// definition ::= 'def' prototype expression
-static FunctionAST *ParseDefinition() {
+static std::unique_ptr<FunctionAST> ParseDefinition() {
   getNextToken(); // eat def.
-  PrototypeAST *Proto = ParsePrototype();
-  if (Proto == 0)
-    return 0;
+  auto Proto = ParsePrototype();
+  if (!Proto)
+    return nullptr;
 
-  if (ExprAST *E = ParseExpression())
-    return new FunctionAST(Proto, E);
-  return 0;
+  if (auto E = ParseExpression())
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
+  return nullptr;
 }
 
 /// toplevelexpr ::= expression
-static FunctionAST *ParseTopLevelExpr() {
-  if (ExprAST *E = ParseExpression()) {
+static std::unique_ptr<FunctionAST> ParseTopLevelExpr() {
+  if (auto E = ParseExpression()) {
     // Make an anonymous proto.
-    PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
-    return new FunctionAST(Proto, E);
+    auto Proto = llvm::make_unique<PrototypeAST>("__anon_expr",
+                                                 std::vector<std::string>());
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
   }
-  return 0;
+  return nullptr;
 }
 
 /// external ::= 'extern' prototype
-static PrototypeAST *ParseExtern() {
+static std::unique_ptr<PrototypeAST> ParseExtern() {
   getNextToken(); // eat extern.
   return ParsePrototype();
 }
@@ -504,31 +510,50 @@ static PrototypeAST *ParseExtern() {
 // Code Generation
 //===----------------------------------------------------------------------===//
 
-static Module *TheModule;
+static std::unique_ptr<Module> TheModule;
 static IRBuilder<> Builder(getGlobalContext());
 static std::map<std::string, Value *> NamedValues;
-static legacy::FunctionPassManager *TheFPM;
+static std::unique_ptr<legacy::FunctionPassManager> TheFPM;
+static std::unique_ptr<KaleidoscopeJIT> TheJIT;
+static std::map<std::string, std::unique_ptr<PrototypeAST>> FunctionProtos;
 
 Value *ErrorV(const char *Str) {
   Error(Str);
-  return 0;
+  return nullptr;
+}
+
+Function *getFunction(std::string Name) {
+  // First, see if the function has already been added to the current module.
+  if (auto *F = TheModule->getFunction(Name))
+    return F;
+
+  // If not, check whether we can codegen the declaration from some existing
+  // prototype.
+  auto FI = FunctionProtos.find(Name);
+  if (FI != FunctionProtos.end())
+    return FI->second->codegen();
+
+  // If no existing prototype exists, return null.
+  return nullptr;
 }
 
-Value *NumberExprAST::Codegen() {
+Value *NumberExprAST::codegen() {
   return ConstantFP::get(getGlobalContext(), APFloat(Val));
 }
 
-Value *VariableExprAST::Codegen() {
+Value *VariableExprAST::codegen() {
   // Look this variable up in the function.
   Value *V = NamedValues[Name];
-  return V ? V : ErrorV("Unknown variable name");
+  if (!V)
+    return ErrorV("Unknown variable name");
+  return V;
 }
 
-Value *BinaryExprAST::Codegen() {
-  Value *L = LHS->Codegen();
-  Value *R = RHS->Codegen();
-  if (L == 0 || R == 0)
-    return 0;
+Value *BinaryExprAST::codegen() {
+  Value *L = LHS->codegen();
+  Value *R = RHS->codegen();
+  if (!L || !R)
+    return nullptr;
 
   switch (Op) {
   case '+':
@@ -547,10 +572,10 @@ Value *BinaryExprAST::Codegen() {
   }
 }
 
-Value *CallExprAST::Codegen() {
+Value *CallExprAST::codegen() {
   // Look up the name in the global module table.
-  Function *CalleeF = TheModule->getFunction(Callee);
-  if (CalleeF == 0)
+  Function *CalleeF = getFunction(Callee);
+  if (!CalleeF)
     return ErrorV("Unknown function referenced");
 
   // If argument mismatch error.
@@ -559,18 +584,18 @@ Value *CallExprAST::Codegen() {
 
   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;
+    ArgsV.push_back(Args[i]->codegen());
+    if (!ArgsV.back())
+      return nullptr;
   }
 
   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 }
 
-Value *IfExprAST::Codegen() {
-  Value *CondV = Cond->Codegen();
-  if (CondV == 0)
-    return 0;
+Value *IfExprAST::codegen() {
+  Value *CondV = Cond->codegen();
+  if (!CondV)
+    return nullptr;
 
   // Convert condition to a bool by comparing equal to 0.0.
   CondV = Builder.CreateFCmpONE(
@@ -590,9 +615,9 @@ Value *IfExprAST::Codegen() {
   // Emit then value.
   Builder.SetInsertPoint(ThenBB);
 
-  Value *ThenV = Then->Codegen();
-  if (ThenV == 0)
-    return 0;
+  Value *ThenV = Then->codegen();
+  if (!ThenV)
+    return nullptr;
 
   Builder.CreateBr(MergeBB);
   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
@@ -602,9 +627,9 @@ Value *IfExprAST::Codegen() {
   TheFunction->getBasicBlockList().push_back(ElseBB);
   Builder.SetInsertPoint(ElseBB);
 
-  Value *ElseV = Else->Codegen();
-  if (ElseV == 0)
-    return 0;
+  Value *ElseV = Else->codegen();
+  if (!ElseV)
+    return nullptr;
 
   Builder.CreateBr(MergeBB);
   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
@@ -621,27 +646,26 @@ Value *IfExprAST::Codegen() {
   return PN;
 }
 
-Value *ForExprAST::Codegen() {
-  // Output this as:
-  //   ...
-  //   start = startexpr
-  //   goto loop
-  // loop:
-  //   variable = phi [start, loopheader], [nextvariable, loopend]
-  //   ...
-  //   bodyexpr
-  //   ...
-  // loopend:
-  //   step = stepexpr
-  //   nextvariable = variable + step
-  //   endcond = endexpr
-  //   br endcond, loop, endloop
-  // outloop:
-
+// Output for-loop as:
+//   ...
+//   start = startexpr
+//   goto loop
+// loop:
+//   variable = phi [start, loopheader], [nextvariable, loopend]
+//   ...
+//   bodyexpr
+//   ...
+// loopend:
+//   step = stepexpr
+//   nextvariable = variable + step
+//   endcond = endexpr
+//   br endcond, loop, endloop
+// outloop:
+Value *ForExprAST::codegen() {
   // Emit the start code first, without 'variable' in scope.
-  Value *StartVal = Start->Codegen();
-  if (StartVal == 0)
-    return 0;
+  Value *StartVal = Start->codegen();
+  if (!StartVal)
+    return nullptr;
 
   // Make the new basic block for the loop header, inserting after current
   // block.
@@ -669,15 +693,15 @@ Value *ForExprAST::Codegen() {
   // 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;
+  if (!Body->codegen())
+    return nullptr;
 
   // Emit the step value.
-  Value *StepVal;
+  Value *StepVal = nullptr;
   if (Step) {
-    StepVal = Step->Codegen();
-    if (StepVal == 0)
-      return 0;
+    StepVal = Step->codegen();
+    if (!StepVal)
+      return nullptr;
   } else {
     // If not specified, use 1.0.
     StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
@@ -686,9 +710,9 @@ Value *ForExprAST::Codegen() {
   Value *NextVar = Builder.CreateFAdd(Variable, StepVal, "nextvar");
 
   // Compute the end condition.
-  Value *EndCond = End->Codegen();
-  if (EndCond == 0)
-    return EndCond;
+  Value *EndCond = End->codegen();
+  if (!EndCond)
+    return nullptr;
 
   // Convert condition to a bool by comparing equal to 0.0.
   EndCond = Builder.CreateFCmpONE(
@@ -718,7 +742,7 @@ Value *ForExprAST::Codegen() {
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
 
-Function *PrototypeAST::Codegen() {
+Function *PrototypeAST::codegen() {
   // Make the function type:  double(double,double) etc.
   std::vector<Type *> Doubles(Args.size(),
                               Type::getDoubleTy(getGlobalContext()));
@@ -726,60 +750,42 @@ Function *PrototypeAST::Codegen() {
       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;
-    }
-  }
+      Function::Create(FT, Function::ExternalLinkage, Name, TheModule.get());
 
   // 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;
-  }
+  for (auto &Arg : F->args())
+    Arg.setName(Args[Idx++]);
 
   return F;
 }
 
-Function *FunctionAST::Codegen() {
-  NamedValues.clear();
-
-  Function *TheFunction = Proto->Codegen();
-  if (TheFunction == 0)
-    return 0;
+Function *FunctionAST::codegen() {
+  // Transfer ownership of the prototype to the FunctionProtos map, but keep a
+  // reference to it for use below.
+  auto &P = *Proto;
+  FunctionProtos[Proto->getName()] = std::move(Proto);
+  Function *TheFunction = getFunction(P.getName());
+  if (!TheFunction)
+    return nullptr;
 
   // Create a new basic block to start insertion into.
   BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
   Builder.SetInsertPoint(BB);
 
-  if (Value *RetVal = Body->Codegen()) {
+  // Record the function arguments in the NamedValues map.
+  NamedValues.clear();
+  for (auto &Arg : TheFunction->args())
+    NamedValues[Arg.getName()] = &Arg;
+
+  if (Value *RetVal = Body->codegen()) {
     // Finish off the function.
     Builder.CreateRet(RetVal);
 
     // Validate the generated code, checking for consistency.
     verifyFunction(*TheFunction);
 
-    // Optimize the function.
+    // Run the optimizer on the function.
     TheFPM->run(*TheFunction);
 
     return TheFunction;
@@ -787,20 +793,40 @@ Function *FunctionAST::Codegen() {
 
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
-  return 0;
+  return nullptr;
 }
 
 //===----------------------------------------------------------------------===//
 // Top-Level parsing and JIT Driver
 //===----------------------------------------------------------------------===//
 
-static ExecutionEngine *TheExecutionEngine;
+static void InitializeModuleAndPassManager() {
+  // Open a new module.
+  TheModule = llvm::make_unique<Module>("my cool jit", getGlobalContext());
+  TheModule->setDataLayout(TheJIT->getTargetMachine().createDataLayout());
+
+  // Create a new pass manager attached to it.
+  TheFPM = llvm::make_unique<legacy::FunctionPassManager>(TheModule.get());
+
+  // Do simple "peephole" optimizations and bit-twiddling optzns.
+  TheFPM->add(createInstructionCombiningPass());
+  // Reassociate expressions.
+  TheFPM->add(createReassociatePass());
+  // Eliminate Common SubExpressions.
+  TheFPM->add(createGVNPass());
+  // Simplify the control flow graph (deleting unreachable blocks, etc).
+  TheFPM->add(createCFGSimplificationPass());
+
+  TheFPM->doInitialization();
+}
 
 static void HandleDefinition() {
-  if (FunctionAST *F = ParseDefinition()) {
-    if (Function *LF = F->Codegen()) {
+  if (auto FnAST = ParseDefinition()) {
+    if (auto *FnIR = FnAST->codegen()) {
       fprintf(stderr, "Read function definition:");
-      LF->dump();
+      FnIR->dump();
+      TheJIT->addModule(std::move(TheModule));
+      InitializeModuleAndPassManager();
     }
   } else {
     // Skip token for error recovery.
@@ -809,10 +835,11 @@ static void HandleDefinition() {
 }
 
 static void HandleExtern() {
-  if (PrototypeAST *P = ParseExtern()) {
-    if (Function *F = P->Codegen()) {
+  if (auto ProtoAST = ParseExtern()) {
+    if (auto *FnIR = ProtoAST->codegen()) {
       fprintf(stderr, "Read extern: ");
-      F->dump();
+      FnIR->dump();
+      FunctionProtos[ProtoAST->getName()] = std::move(ProtoAST);
     }
   } else {
     // Skip token for error recovery.
@@ -822,16 +849,25 @@ static void HandleExtern() {
 
 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;
+  if (auto FnAST = ParseTopLevelExpr()) {
+    if (FnAST->codegen()) {
+
+      // JIT the module containing the anonymous expression, keeping a handle so
+      // we can free it later.
+      auto H = TheJIT->addModule(std::move(TheModule));
+      InitializeModuleAndPassManager();
+
+      // Search the JIT for the __anon_expr symbol.
+      auto ExprSymbol = TheJIT->findSymbol("__anon_expr");
+      assert(ExprSymbol && "Function not found");
+
+      // Get the symbol's address and 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();
       fprintf(stderr, "Evaluated to %f\n", FP());
+
+      // Delete the anonymous expression module from the JIT.
+      TheJIT->removeModule(H);
     }
   } else {
     // Skip token for error recovery.
@@ -846,9 +882,9 @@ static void MainLoop() {
     switch (CurTok) {
     case tok_eof:
       return;
-    case ';':
+    case ';': // ignore top-level semicolons.
       getNextToken();
-      break; // ignore top-level semicolons.
+      break;
     case tok_def:
       HandleDefinition();
       break;
@@ -868,7 +904,13 @@ static void MainLoop() {
 
 /// putchard - putchar that takes a double and returns 0.
 extern "C" double putchard(double X) {
-  putchar((char)X);
+  fputc((char)X, stderr);
+  return 0;
+}
+
+/// printd - printf that takes a double prints it as "%f\n", returning 0.
+extern "C" double printd(double X) {
+  fprintf(stderr, "%f\n", X);
   return 0;
 }
 
@@ -880,7 +922,6 @@ int main() {
   InitializeNativeTarget();
   InitializeNativeTargetAsmPrinter();
   InitializeNativeTargetAsmParser();
-  LLVMContext &Context = getGlobalContext();
 
   // Install standard binary operators.
   // 1 is lowest precedence.
@@ -893,50 +934,12 @@ int main() {
   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)
-          .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());
-  // 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();
+  TheJIT = llvm::make_unique<KaleidoscopeJIT>();
 
-  // Set the global so the code gen can use this.
-  TheFPM = &OurFPM;
+  InitializeModuleAndPassManager();
 
   // Run the main "interpreter loop" now.
   MainLoop();
 
-  TheFPM = 0;
-
-  // Print out all of the generated code.
-  TheModule->dump();
-
   return 0;
 }
diff --git a/examples/Kaleidoscope/Chapter6/CMakeLists.txt b/examples/Kaleidoscope/Chapter6/CMakeLists.txt
index 7ac1ca49c4f9..49627f07ddf0 100644
--- a/examples/Kaleidoscope/Chapter6/CMakeLists.txt
+++ b/examples/Kaleidoscope/Chapter6/CMakeLists.txt
@@ -3,7 +3,7 @@ set(LLVM_LINK_COMPONENTS
   Core
   ExecutionEngine
   InstCombine
-  MCJIT
+  Object
   RuntimeDyld
   ScalarOpts
   Support
@@ -13,3 +13,5 @@ set(LLVM_LINK_COMPONENTS
 add_kaleidoscope_chapter(Kaleidoscope-Ch6
   toy.cpp
   )
+
+export_executable_symbols(Kaleidoscope-Ch6)
diff --git a/examples/Kaleidoscope/Chapter6/toy.cpp b/examples/Kaleidoscope/Chapter6/toy.cpp
index e978a3ea3682..4d04f7e888af 100644
--- a/examples/Kaleidoscope/Chapter6/toy.cpp
+++ b/examples/Kaleidoscope/Chapter6/toy.cpp
@@ -1,10 +1,5 @@
 #include "llvm/ADT/STLExtras.h"
 #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"
@@ -17,7 +12,10 @@
 #include <map>
 #include <string>
 #include <vector>
+#include "../include/KaleidoscopeJIT.h"
+
 using namespace llvm;
+using namespace llvm::orc;
 
 //===----------------------------------------------------------------------===//
 // Lexer
@@ -92,7 +90,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -124,7 +122,7 @@ namespace {
 class ExprAST {
 public:
   virtual ~ExprAST() {}
-  virtual Value *Codegen() = 0;
+  virtual Value *codegen() = 0;
 };
 
 /// NumberExprAST - Expression class for numeric literals like "1.0".
@@ -132,8 +130,8 @@ class NumberExprAST : public ExprAST {
   double Val;
 
 public:
-  NumberExprAST(double val) : Val(val) {}
-  Value *Codegen() override;
+  NumberExprAST(double Val) : Val(Val) {}
+  Value *codegen() override;
 };
 
 /// VariableExprAST - Expression class for referencing a variable, like "a".
@@ -141,63 +139,68 @@ class VariableExprAST : public ExprAST {
   std::string Name;
 
 public:
-  VariableExprAST(const std::string &name) : Name(name) {}
-  Value *Codegen() override;
+  VariableExprAST(const std::string &Name) : Name(Name) {}
+  Value *codegen() override;
 };
 
 /// UnaryExprAST - Expression class for a unary operator.
 class UnaryExprAST : public ExprAST {
   char Opcode;
-  ExprAST *Operand;
+  std::unique_ptr<ExprAST> Operand;
 
 public:
-  UnaryExprAST(char opcode, ExprAST *operand)
-      : Opcode(opcode), Operand(operand) {}
-  Value *Codegen() override;
+  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand)
+      : Opcode(Opcode), Operand(std::move(Operand)) {}
+  Value *codegen() override;
 };
 
 /// BinaryExprAST - Expression class for a binary operator.
 class BinaryExprAST : public ExprAST {
   char Op;
-  ExprAST *LHS, *RHS;
+  std::unique_ptr<ExprAST> LHS, RHS;
 
 public:
-  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
-      : Op(op), LHS(lhs), RHS(rhs) {}
-  Value *Codegen() override;
+  BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
+                std::unique_ptr<ExprAST> RHS)
+      : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
+  Value *codegen() override;
 };
 
 /// CallExprAST - Expression class for function calls.
 class CallExprAST : public ExprAST {
   std::string Callee;
-  std::vector<ExprAST *> Args;
+  std::vector<std::unique_ptr<ExprAST>> Args;
 
 public:
-  CallExprAST(const std::string &callee, std::vector<ExprAST *> &args)
-      : Callee(callee), Args(args) {}
-  Value *Codegen() override;
+  CallExprAST(const std::string &Callee,
+              std::vector<std::unique_ptr<ExprAST>> Args)
+      : Callee(Callee), Args(std::move(Args)) {}
+  Value *codegen() override;
 };
 
 /// IfExprAST - Expression class for if/then/else.
 class IfExprAST : public ExprAST {
-  ExprAST *Cond, *Then, *Else;
+  std::unique_ptr<ExprAST> Cond, Then, Else;
 
 public:
-  IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
-      : Cond(cond), Then(then), Else(_else) {}
-  Value *Codegen() override;
+  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 *codegen() override;
 };
 
 /// ForExprAST - Expression class for for/in.
 class ForExprAST : public ExprAST {
   std::string VarName;
-  ExprAST *Start, *End, *Step, *Body;
+  std::unique_ptr<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) {}
-  Value *Codegen() override;
+  ForExprAST(const std::string &VarName, std::unique_ptr<ExprAST> Start,
+             std::unique_ptr<ExprAST> End, std::unique_ptr<ExprAST> Step,
+             std::unique_ptr<ExprAST> Body)
+      : VarName(VarName), Start(std::move(Start)), End(std::move(End)),
+        Step(std::move(Step)), Body(std::move(Body)) {}
+  Value *codegen() override;
 };
 
 /// PrototypeAST - This class represents the "prototype" for a function,
@@ -206,15 +209,19 @@ public:
 class PrototypeAST {
   std::string Name;
   std::vector<std::string> Args;
-  bool isOperator;
+  bool IsOperator;
   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) {}
+  PrototypeAST(const std::string &Name, std::vector<std::string> Args,
+               bool IsOperator = false, unsigned Prec = 0)
+      : Name(Name), Args(std::move(Args)), IsOperator(IsOperator),
+        Precedence(Prec) {}
+  Function *codegen();
+  const std::string &getName() const { return Name; }
 
-  bool isUnaryOp() const { return isOperator && Args.size() == 1; }
-  bool isBinaryOp() const { return isOperator && Args.size() == 2; }
+  bool isUnaryOp() const { return IsOperator && Args.size() == 1; }
+  bool isBinaryOp() const { return IsOperator && Args.size() == 2; }
 
   char getOperatorName() const {
     assert(isUnaryOp() || isBinaryOp());
@@ -222,19 +229,18 @@ public:
   }
 
   unsigned getBinaryPrecedence() const { return Precedence; }
-
-  Function *Codegen();
 };
 
 /// FunctionAST - This class represents a function definition itself.
 class FunctionAST {
-  PrototypeAST *Proto;
-  ExprAST *Body;
+  std::unique_ptr<PrototypeAST> Proto;
+  std::unique_ptr<ExprAST> Body;
 
 public:
-  FunctionAST(PrototypeAST *proto, ExprAST *body) : Proto(proto), Body(body) {}
-
-  Function *Codegen();
+  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
+              std::unique_ptr<ExprAST> Body)
+      : Proto(std::move(Proto)), Body(std::move(Body)) {}
+  Function *codegen();
 };
 } // end anonymous namespace
 
@@ -265,41 +271,58 @@ static int GetTokPrecedence() {
 }
 
 /// Error* - These are little helper functions for error handling.
-ExprAST *Error(const char *Str) {
+std::unique_ptr<ExprAST> Error(const char *Str) {
   fprintf(stderr, "Error: %s\n", Str);
-  return 0;
+  return nullptr;
 }
-PrototypeAST *ErrorP(const char *Str) {
+
+std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
   Error(Str);
-  return 0;
+  return nullptr;
 }
-FunctionAST *ErrorF(const char *Str) {
-  Error(Str);
-  return 0;
+
+static std::unique_ptr<ExprAST> ParseExpression();
+
+/// numberexpr ::= number
+static std::unique_ptr<ExprAST> ParseNumberExpr() {
+  auto Result = llvm::make_unique<NumberExprAST>(NumVal);
+  getNextToken(); // consume the number
+  return std::move(Result);
 }
 
-static ExprAST *ParseExpression();
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+  getNextToken(); // eat (.
+  auto V = ParseExpression();
+  if (!V)
+    return nullptr;
+
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken(); // eat ).
+  return V;
+}
 
 /// identifierexpr
 ///   ::= identifier
 ///   ::= identifier '(' expression* ')'
-static ExprAST *ParseIdentifierExpr() {
+static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
 
   getNextToken(); // eat identifier.
 
   if (CurTok != '(') // Simple variable ref.
-    return new VariableExprAST(IdName);
+    return llvm::make_unique<VariableExprAST>(IdName);
 
   // Call.
   getNextToken(); // eat (
-  std::vector<ExprAST *> Args;
+  std::vector<std::unique_ptr<ExprAST>> Args;
   if (CurTok != ')') {
     while (1) {
-      ExprAST *Arg = ParseExpression();
-      if (!Arg)
-        return 0;
-      Args.push_back(Arg);
+      if (auto Arg = ParseExpression())
+        Args.push_back(std::move(Arg));
+      else
+        return nullptr;
 
       if (CurTok == ')')
         break;
@@ -313,60 +336,41 @@ static ExprAST *ParseIdentifierExpr() {
   // Eat the ')'.
   getNextToken();
 
-  return new CallExprAST(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;
+  return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
 }
 
 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
-static ExprAST *ParseIfExpr() {
+static std::unique_ptr<ExprAST> ParseIfExpr() {
   getNextToken(); // eat the if.
 
   // condition.
-  ExprAST *Cond = ParseExpression();
+  auto Cond = ParseExpression();
   if (!Cond)
-    return 0;
+    return nullptr;
 
   if (CurTok != tok_then)
     return Error("expected then");
   getNextToken(); // eat the then
 
-  ExprAST *Then = ParseExpression();
-  if (Then == 0)
-    return 0;
+  auto Then = ParseExpression();
+  if (!Then)
+    return nullptr;
 
   if (CurTok != tok_else)
     return Error("expected else");
 
   getNextToken();
 
-  ExprAST *Else = ParseExpression();
+  auto Else = ParseExpression();
   if (!Else)
-    return 0;
+    return nullptr;
 
-  return new IfExprAST(Cond, Then, Else);
+  return llvm::make_unique<IfExprAST>(std::move(Cond), std::move(Then),
+                                      std::move(Else));
 }
 
 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
-static ExprAST *ParseForExpr() {
+static std::unique_ptr<ExprAST> ParseForExpr() {
   getNextToken(); // eat the for.
 
   if (CurTok != tok_identifier)
@@ -379,35 +383,36 @@ static ExprAST *ParseForExpr() {
     return Error("expected '=' after for");
   getNextToken(); // eat '='.
 
-  ExprAST *Start = ParseExpression();
-  if (Start == 0)
-    return 0;
+  auto Start = ParseExpression();
+  if (!Start)
+    return nullptr;
   if (CurTok != ',')
     return Error("expected ',' after for start value");
   getNextToken();
 
-  ExprAST *End = ParseExpression();
-  if (End == 0)
-    return 0;
+  auto End = ParseExpression();
+  if (!End)
+    return nullptr;
 
   // The step value is optional.
-  ExprAST *Step = 0;
+  std::unique_ptr<ExprAST> Step;
   if (CurTok == ',') {
     getNextToken();
     Step = ParseExpression();
-    if (Step == 0)
-      return 0;
+    if (!Step)
+      return nullptr;
   }
 
   if (CurTok != tok_in)
     return Error("expected 'in' after for");
   getNextToken(); // eat 'in'.
 
-  ExprAST *Body = ParseExpression();
-  if (Body == 0)
-    return 0;
+  auto Body = ParseExpression();
+  if (!Body)
+    return nullptr;
 
-  return new ForExprAST(IdName, Start, End, Step, Body);
+  return llvm::make_unique<ForExprAST>(IdName, std::move(Start), std::move(End),
+                                       std::move(Step), std::move(Body));
 }
 
 /// primary
@@ -416,7 +421,7 @@ static ExprAST *ParseForExpr() {
 ///   ::= parenexpr
 ///   ::= ifexpr
 ///   ::= forexpr
-static ExprAST *ParsePrimary() {
+static std::unique_ptr<ExprAST> ParsePrimary() {
   switch (CurTok) {
   default:
     return Error("unknown token when expecting an expression");
@@ -436,7 +441,7 @@ static ExprAST *ParsePrimary() {
 /// unary
 ///   ::= primary
 ///   ::= '!' unary
-static ExprAST *ParseUnary() {
+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();
@@ -444,14 +449,15 @@ static ExprAST *ParseUnary() {
   // If this is a unary operator, read it.
   int Opc = CurTok;
   getNextToken();
-  if (ExprAST *Operand = ParseUnary())
-    return new UnaryExprAST(Opc, Operand);
-  return 0;
+  if (auto Operand = ParseUnary())
+    return llvm::make_unique<UnaryExprAST>(Opc, std::move(Operand));
+  return nullptr;
 }
 
 /// binoprhs
 ///   ::= ('+' unary)*
-static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+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();
@@ -466,40 +472,41 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
     getNextToken(); // eat binop
 
     // Parse the unary expression after the binary operator.
-    ExprAST *RHS = ParseUnary();
+    auto RHS = ParseUnary();
     if (!RHS)
-      return 0;
+      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, RHS);
-      if (RHS == 0)
-        return 0;
+      RHS = ParseBinOpRHS(TokPrec + 1, std::move(RHS));
+      if (!RHS)
+        return nullptr;
     }
 
     // Merge LHS/RHS.
-    LHS = new BinaryExprAST(BinOp, LHS, RHS);
+    LHS =
+        llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
   }
 }
 
 /// expression
 ///   ::= unary binoprhs
 ///
-static ExprAST *ParseExpression() {
-  ExprAST *LHS = ParseUnary();
+static std::unique_ptr<ExprAST> ParseExpression() {
+  auto LHS = ParseUnary();
   if (!LHS)
-    return 0;
+    return nullptr;
 
-  return ParseBinOpRHS(0, LHS);
+  return ParseBinOpRHS(0, std::move(LHS));
 }
 
 /// prototype
 ///   ::= id '(' id* ')'
 ///   ::= binary LETTER number? (id, id)
 ///   ::= unary LETTER (id)
-static PrototypeAST *ParsePrototype() {
+static std::unique_ptr<PrototypeAST> ParsePrototype() {
   std::string FnName;
 
   unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
@@ -557,33 +564,35 @@ static PrototypeAST *ParsePrototype() {
   if (Kind && ArgNames.size() != Kind)
     return ErrorP("Invalid number of operands for operator");
 
-  return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
+  return llvm::make_unique<PrototypeAST>(FnName, ArgNames, Kind != 0,
+                                         BinaryPrecedence);
 }
 
 /// definition ::= 'def' prototype expression
-static FunctionAST *ParseDefinition() {
+static std::unique_ptr<FunctionAST> ParseDefinition() {
   getNextToken(); // eat def.
-  PrototypeAST *Proto = ParsePrototype();
-  if (Proto == 0)
-    return 0;
+  auto Proto = ParsePrototype();
+  if (!Proto)
+    return nullptr;
 
-  if (ExprAST *E = ParseExpression())
-    return new FunctionAST(Proto, E);
-  return 0;
+  if (auto E = ParseExpression())
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
+  return nullptr;
 }
 
 /// toplevelexpr ::= expression
-static FunctionAST *ParseTopLevelExpr() {
-  if (ExprAST *E = ParseExpression()) {
+static std::unique_ptr<FunctionAST> ParseTopLevelExpr() {
+  if (auto E = ParseExpression()) {
     // Make an anonymous proto.
-    PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
-    return new FunctionAST(Proto, E);
+    auto Proto = llvm::make_unique<PrototypeAST>("__anon_expr",
+                                                 std::vector<std::string>());
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
   }
-  return 0;
+  return nullptr;
 }
 
 /// external ::= 'extern' prototype
-static PrototypeAST *ParseExtern() {
+static std::unique_ptr<PrototypeAST> ParseExtern() {
   getNextToken(); // eat extern.
   return ParsePrototype();
 }
@@ -592,43 +601,62 @@ static PrototypeAST *ParseExtern() {
 // Code Generation
 //===----------------------------------------------------------------------===//
 
-static Module *TheModule;
+static std::unique_ptr<Module> TheModule;
 static IRBuilder<> Builder(getGlobalContext());
 static std::map<std::string, Value *> NamedValues;
-static legacy::FunctionPassManager *TheFPM;
+static std::unique_ptr<legacy::FunctionPassManager> TheFPM;
+static std::unique_ptr<KaleidoscopeJIT> TheJIT;
+static std::map<std::string, std::unique_ptr<PrototypeAST>> FunctionProtos;
 
 Value *ErrorV(const char *Str) {
   Error(Str);
-  return 0;
+  return nullptr;
 }
 
-Value *NumberExprAST::Codegen() {
+Function *getFunction(std::string Name) {
+  // First, see if the function has already been added to the current module.
+  if (auto *F = TheModule->getFunction(Name))
+    return F;
+
+  // If not, check whether we can codegen the declaration from some existing
+  // prototype.
+  auto FI = FunctionProtos.find(Name);
+  if (FI != FunctionProtos.end())
+    return FI->second->codegen();
+
+  // If no existing prototype exists, return null.
+  return nullptr;
+}
+
+Value *NumberExprAST::codegen() {
   return ConstantFP::get(getGlobalContext(), APFloat(Val));
 }
 
-Value *VariableExprAST::Codegen() {
+Value *VariableExprAST::codegen() {
   // Look this variable up in the function.
   Value *V = NamedValues[Name];
-  return V ? V : ErrorV("Unknown variable name");
+  if (!V)
+    return ErrorV("Unknown variable name");
+  return V;
 }
 
-Value *UnaryExprAST::Codegen() {
-  Value *OperandV = Operand->Codegen();
-  if (OperandV == 0)
-    return 0;
+Value *UnaryExprAST::codegen() {
+  Value *OperandV = Operand->codegen();
+  if (!OperandV)
+    return nullptr;
 
-  Function *F = TheModule->getFunction(std::string("unary") + Opcode);
-  if (F == 0)
+  Function *F = getFunction(std::string("unary") + Opcode);
+  if (!F)
     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;
+Value *BinaryExprAST::codegen() {
+  Value *L = LHS->codegen();
+  Value *R = RHS->codegen();
+  if (!L || !R)
+    return nullptr;
 
   switch (Op) {
   case '+':
@@ -648,17 +676,17 @@ Value *BinaryExprAST::Codegen() {
 
   // 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 = getFunction(std::string("binary") + Op);
   assert(F && "binary operator not found!");
 
-  Value *Ops[] = { L, R };
+  Value *Ops[] = {L, R};
   return Builder.CreateCall(F, Ops, "binop");
 }
 
-Value *CallExprAST::Codegen() {
+Value *CallExprAST::codegen() {
   // Look up the name in the global module table.
-  Function *CalleeF = TheModule->getFunction(Callee);
-  if (CalleeF == 0)
+  Function *CalleeF = getFunction(Callee);
+  if (!CalleeF)
     return ErrorV("Unknown function referenced");
 
   // If argument mismatch error.
@@ -667,18 +695,18 @@ Value *CallExprAST::Codegen() {
 
   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;
+    ArgsV.push_back(Args[i]->codegen());
+    if (!ArgsV.back())
+      return nullptr;
   }
 
   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 }
 
-Value *IfExprAST::Codegen() {
-  Value *CondV = Cond->Codegen();
-  if (CondV == 0)
-    return 0;
+Value *IfExprAST::codegen() {
+  Value *CondV = Cond->codegen();
+  if (!CondV)
+    return nullptr;
 
   // Convert condition to a bool by comparing equal to 0.0.
   CondV = Builder.CreateFCmpONE(
@@ -698,9 +726,9 @@ Value *IfExprAST::Codegen() {
   // Emit then value.
   Builder.SetInsertPoint(ThenBB);
 
-  Value *ThenV = Then->Codegen();
-  if (ThenV == 0)
-    return 0;
+  Value *ThenV = Then->codegen();
+  if (!ThenV)
+    return nullptr;
 
   Builder.CreateBr(MergeBB);
   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
@@ -710,9 +738,9 @@ Value *IfExprAST::Codegen() {
   TheFunction->getBasicBlockList().push_back(ElseBB);
   Builder.SetInsertPoint(ElseBB);
 
-  Value *ElseV = Else->Codegen();
-  if (ElseV == 0)
-    return 0;
+  Value *ElseV = Else->codegen();
+  if (!ElseV)
+    return nullptr;
 
   Builder.CreateBr(MergeBB);
   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
@@ -729,27 +757,26 @@ Value *IfExprAST::Codegen() {
   return PN;
 }
 
-Value *ForExprAST::Codegen() {
-  // Output this as:
-  //   ...
-  //   start = startexpr
-  //   goto loop
-  // loop:
-  //   variable = phi [start, loopheader], [nextvariable, loopend]
-  //   ...
-  //   bodyexpr
-  //   ...
-  // loopend:
-  //   step = stepexpr
-  //   nextvariable = variable + step
-  //   endcond = endexpr
-  //   br endcond, loop, endloop
-  // outloop:
-
+// Output for-loop as:
+//   ...
+//   start = startexpr
+//   goto loop
+// loop:
+//   variable = phi [start, loopheader], [nextvariable, loopend]
+//   ...
+//   bodyexpr
+//   ...
+// loopend:
+//   step = stepexpr
+//   nextvariable = variable + step
+//   endcond = endexpr
+//   br endcond, loop, endloop
+// outloop:
+Value *ForExprAST::codegen() {
   // Emit the start code first, without 'variable' in scope.
-  Value *StartVal = Start->Codegen();
-  if (StartVal == 0)
-    return 0;
+  Value *StartVal = Start->codegen();
+  if (!StartVal)
+    return nullptr;
 
   // Make the new basic block for the loop header, inserting after current
   // block.
@@ -777,15 +804,15 @@ Value *ForExprAST::Codegen() {
   // 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;
+  if (!Body->codegen())
+    return nullptr;
 
   // Emit the step value.
-  Value *StepVal;
+  Value *StepVal = nullptr;
   if (Step) {
-    StepVal = Step->Codegen();
-    if (StepVal == 0)
-      return 0;
+    StepVal = Step->codegen();
+    if (!StepVal)
+      return nullptr;
   } else {
     // If not specified, use 1.0.
     StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
@@ -794,9 +821,9 @@ Value *ForExprAST::Codegen() {
   Value *NextVar = Builder.CreateFAdd(Variable, StepVal, "nextvar");
 
   // Compute the end condition.
-  Value *EndCond = End->Codegen();
-  if (EndCond == 0)
-    return EndCond;
+  Value *EndCond = End->codegen();
+  if (!EndCond)
+    return nullptr;
 
   // Convert condition to a bool by comparing equal to 0.0.
   EndCond = Builder.CreateFCmpONE(
@@ -826,7 +853,7 @@ Value *ForExprAST::Codegen() {
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
 
-Function *PrototypeAST::Codegen() {
+Function *PrototypeAST::codegen() {
   // Make the function type:  double(double,double) etc.
   std::vector<Type *> Doubles(Args.size(),
                               Type::getDoubleTy(getGlobalContext()));
@@ -834,64 +861,46 @@ Function *PrototypeAST::Codegen() {
       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;
-    }
-  }
+      Function::Create(FT, Function::ExternalLinkage, Name, TheModule.get());
 
   // 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;
-  }
+  for (auto &Arg : F->args())
+    Arg.setName(Args[Idx++]);
 
   return F;
 }
 
-Function *FunctionAST::Codegen() {
-  NamedValues.clear();
-
-  Function *TheFunction = Proto->Codegen();
-  if (TheFunction == 0)
-    return 0;
+Function *FunctionAST::codegen() {
+  // Transfer ownership of the prototype to the FunctionProtos map, but keep a
+  // reference to it for use below.
+  auto &P = *Proto;
+  FunctionProtos[Proto->getName()] = std::move(Proto);
+  Function *TheFunction = getFunction(P.getName());
+  if (!TheFunction)
+    return nullptr;
 
   // If this is an operator, install it.
-  if (Proto->isBinaryOp())
-    BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
+  if (P.isBinaryOp())
+    BinopPrecedence[P.getOperatorName()] = P.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()) {
+  // Record the function arguments in the NamedValues map.
+  NamedValues.clear();
+  for (auto &Arg : TheFunction->args())
+    NamedValues[Arg.getName()] = &Arg;
+
+  if (Value *RetVal = Body->codegen()) {
     // Finish off the function.
     Builder.CreateRet(RetVal);
 
     // Validate the generated code, checking for consistency.
     verifyFunction(*TheFunction);
 
-    // Optimize the function.
+    // Run the optimizer on the function.
     TheFPM->run(*TheFunction);
 
     return TheFunction;
@@ -900,22 +909,42 @@ Function *FunctionAST::Codegen() {
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
 
-  if (Proto->isBinaryOp())
+  if (P.isBinaryOp())
     BinopPrecedence.erase(Proto->getOperatorName());
-  return 0;
+  return nullptr;
 }
 
 //===----------------------------------------------------------------------===//
 // Top-Level parsing and JIT Driver
 //===----------------------------------------------------------------------===//
 
-static ExecutionEngine *TheExecutionEngine;
+static void InitializeModuleAndPassManager() {
+  // Open a new module.
+  TheModule = llvm::make_unique<Module>("my cool jit", getGlobalContext());
+  TheModule->setDataLayout(TheJIT->getTargetMachine().createDataLayout());
+
+  // Create a new pass manager attached to it.
+  TheFPM = llvm::make_unique<legacy::FunctionPassManager>(TheModule.get());
+
+  // Do simple "peephole" optimizations and bit-twiddling optzns.
+  TheFPM->add(createInstructionCombiningPass());
+  // Reassociate expressions.
+  TheFPM->add(createReassociatePass());
+  // Eliminate Common SubExpressions.
+  TheFPM->add(createGVNPass());
+  // Simplify the control flow graph (deleting unreachable blocks, etc).
+  TheFPM->add(createCFGSimplificationPass());
+
+  TheFPM->doInitialization();
+}
 
 static void HandleDefinition() {
-  if (FunctionAST *F = ParseDefinition()) {
-    if (Function *LF = F->Codegen()) {
+  if (auto FnAST = ParseDefinition()) {
+    if (auto *FnIR = FnAST->codegen()) {
       fprintf(stderr, "Read function definition:");
-      LF->dump();
+      FnIR->dump();
+      TheJIT->addModule(std::move(TheModule));
+      InitializeModuleAndPassManager();
     }
   } else {
     // Skip token for error recovery.
@@ -924,10 +953,11 @@ static void HandleDefinition() {
 }
 
 static void HandleExtern() {
-  if (PrototypeAST *P = ParseExtern()) {
-    if (Function *F = P->Codegen()) {
+  if (auto ProtoAST = ParseExtern()) {
+    if (auto *FnIR = ProtoAST->codegen()) {
       fprintf(stderr, "Read extern: ");
-      F->dump();
+      FnIR->dump();
+      FunctionProtos[ProtoAST->getName()] = std::move(ProtoAST);
     }
   } else {
     // Skip token for error recovery.
@@ -937,16 +967,25 @@ static void HandleExtern() {
 
 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;
+  if (auto FnAST = ParseTopLevelExpr()) {
+    if (FnAST->codegen()) {
+
+      // JIT the module containing the anonymous expression, keeping a handle so
+      // we can free it later.
+      auto H = TheJIT->addModule(std::move(TheModule));
+      InitializeModuleAndPassManager();
+
+      // Search the JIT for the __anon_expr symbol.
+      auto ExprSymbol = TheJIT->findSymbol("__anon_expr");
+      assert(ExprSymbol && "Function not found");
+
+      // Get the symbol's address and 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();
       fprintf(stderr, "Evaluated to %f\n", FP());
+
+      // Delete the anonymous expression module from the JIT.
+      TheJIT->removeModule(H);
     }
   } else {
     // Skip token for error recovery.
@@ -961,9 +1000,9 @@ static void MainLoop() {
     switch (CurTok) {
     case tok_eof:
       return;
-    case ';':
+    case ';': // ignore top-level semicolons.
       getNextToken();
-      break; // ignore top-level semicolons.
+      break;
     case tok_def:
       HandleDefinition();
       break;
@@ -983,13 +1022,13 @@ static void MainLoop() {
 
 /// putchard - putchar that takes a double and returns 0.
 extern "C" double putchard(double X) {
-  putchar((char)X);
+  fputc((char)X, stderr);
   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);
+  fprintf(stderr, "%f\n", X);
   return 0;
 }
 
@@ -1001,7 +1040,6 @@ int main() {
   InitializeNativeTarget();
   InitializeNativeTargetAsmPrinter();
   InitializeNativeTargetAsmParser();
-  LLVMContext &Context = getGlobalContext();
 
   // Install standard binary operators.
   // 1 is lowest precedence.
@@ -1014,50 +1052,12 @@ int main() {
   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)
-          .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());
-  // 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();
+  TheJIT = llvm::make_unique<KaleidoscopeJIT>();
 
-  // Set the global so the code gen can use this.
-  TheFPM = &OurFPM;
+  InitializeModuleAndPassManager();
 
   // Run the main "interpreter loop" now.
   MainLoop();
 
-  TheFPM = 0;
-
-  // Print out all of the generated code.
-  TheModule->dump();
-
   return 0;
 }
diff --git a/examples/Kaleidoscope/Chapter7/CMakeLists.txt b/examples/Kaleidoscope/Chapter7/CMakeLists.txt
index 8725e4761f78..e67d7928efe7 100644
--- a/examples/Kaleidoscope/Chapter7/CMakeLists.txt
+++ b/examples/Kaleidoscope/Chapter7/CMakeLists.txt
@@ -3,14 +3,15 @@ set(LLVM_LINK_COMPONENTS
   Core
   ExecutionEngine
   InstCombine
-  MCJIT
+  Object
   RuntimeDyld
   ScalarOpts
   Support
-  TransformUtils
   native
   )
 
 add_kaleidoscope_chapter(Kaleidoscope-Ch7
   toy.cpp
   )
+
+export_executable_symbols(Kaleidoscope-Ch7)
diff --git a/examples/Kaleidoscope/Chapter7/toy.cpp b/examples/Kaleidoscope/Chapter7/toy.cpp
index b1a41fa01b76..5c0094013d97 100644
--- a/examples/Kaleidoscope/Chapter7/toy.cpp
+++ b/examples/Kaleidoscope/Chapter7/toy.cpp
@@ -1,10 +1,5 @@
 #include "llvm/ADT/STLExtras.h"
 #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"
@@ -17,7 +12,10 @@
 #include <map>
 #include <string>
 #include <vector>
+#include "../include/KaleidoscopeJIT.h"
+
 using namespace llvm;
+using namespace llvm::orc;
 
 //===----------------------------------------------------------------------===//
 // Lexer
@@ -97,7 +95,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -129,7 +127,7 @@ namespace {
 class ExprAST {
 public:
   virtual ~ExprAST() {}
-  virtual Value *Codegen() = 0;
+  virtual Value *codegen() = 0;
 };
 
 /// NumberExprAST - Expression class for numeric literals like "1.0".
@@ -137,8 +135,8 @@ class NumberExprAST : public ExprAST {
   double Val;
 
 public:
-  NumberExprAST(double val) : Val(val) {}
-  Value *Codegen() override;
+  NumberExprAST(double Val) : Val(Val) {}
+  Value *codegen() override;
 };
 
 /// VariableExprAST - Expression class for referencing a variable, like "a".
@@ -146,93 +144,103 @@ class VariableExprAST : public ExprAST {
   std::string Name;
 
 public:
-  VariableExprAST(const std::string &name) : Name(name) {}
+  VariableExprAST(const std::string &Name) : Name(Name) {}
   const std::string &getName() const { return Name; }
-  Value *Codegen() override;
+  Value *codegen() override;
 };
 
 /// UnaryExprAST - Expression class for a unary operator.
 class UnaryExprAST : public ExprAST {
   char Opcode;
-  ExprAST *Operand;
+  std::unique_ptr<ExprAST> Operand;
 
 public:
-  UnaryExprAST(char opcode, ExprAST *operand)
-      : Opcode(opcode), Operand(operand) {}
-  Value *Codegen() override;
+  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand)
+      : Opcode(Opcode), Operand(std::move(Operand)) {}
+  Value *codegen() override;
 };
 
 /// BinaryExprAST - Expression class for a binary operator.
 class BinaryExprAST : public ExprAST {
   char Op;
-  ExprAST *LHS, *RHS;
+  std::unique_ptr<ExprAST> LHS, RHS;
 
 public:
-  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
-      : Op(op), LHS(lhs), RHS(rhs) {}
-  Value *Codegen() override;
+  BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
+                std::unique_ptr<ExprAST> RHS)
+      : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
+  Value *codegen() override;
 };
 
 /// CallExprAST - Expression class for function calls.
 class CallExprAST : public ExprAST {
   std::string Callee;
-  std::vector<ExprAST *> Args;
+  std::vector<std::unique_ptr<ExprAST>> Args;
 
 public:
-  CallExprAST(const std::string &callee, std::vector<ExprAST *> &args)
-      : Callee(callee), Args(args) {}
-  Value *Codegen() override;
+  CallExprAST(const std::string &Callee,
+              std::vector<std::unique_ptr<ExprAST>> Args)
+      : Callee(Callee), Args(std::move(Args)) {}
+  Value *codegen() override;
 };
 
 /// IfExprAST - Expression class for if/then/else.
 class IfExprAST : public ExprAST {
-  ExprAST *Cond, *Then, *Else;
+  std::unique_ptr<ExprAST> Cond, Then, Else;
 
 public:
-  IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
-      : Cond(cond), Then(then), Else(_else) {}
-  Value *Codegen() override;
+  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 *codegen() override;
 };
 
 /// ForExprAST - Expression class for for/in.
 class ForExprAST : public ExprAST {
   std::string VarName;
-  ExprAST *Start, *End, *Step, *Body;
+  std::unique_ptr<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) {}
-  Value *Codegen() override;
+  ForExprAST(const std::string &VarName, std::unique_ptr<ExprAST> Start,
+             std::unique_ptr<ExprAST> End, std::unique_ptr<ExprAST> Step,
+             std::unique_ptr<ExprAST> Body)
+      : VarName(VarName), Start(std::move(Start)), End(std::move(End)),
+        Step(std::move(Step)), Body(std::move(Body)) {}
+  Value *codegen() override;
 };
 
 /// VarExprAST - Expression class for var/in
 class VarExprAST : public ExprAST {
-  std::vector<std::pair<std::string, ExprAST *> > VarNames;
-  ExprAST *Body;
+  std::vector<std::pair<std::string, std::unique_ptr<ExprAST>>> VarNames;
+  std::unique_ptr<ExprAST> Body;
 
 public:
-  VarExprAST(const std::vector<std::pair<std::string, ExprAST *> > &varnames,
-             ExprAST *body)
-      : VarNames(varnames), Body(body) {}
-
-  Value *Codegen() override;
+  VarExprAST(
+      std::vector<std::pair<std::string, std::unique_ptr<ExprAST>>> VarNames,
+      std::unique_ptr<ExprAST> Body)
+      : VarNames(std::move(VarNames)), Body(std::move(Body)) {}
+  Value *codegen() override;
 };
 
 /// PrototypeAST - This class represents the "prototype" for a function,
-/// which captures its argument names as well as if it is an operator.
+/// which captures its name, and its argument names (thus implicitly the number
+/// of arguments the function takes), as well as if it is an operator.
 class PrototypeAST {
   std::string Name;
   std::vector<std::string> Args;
-  bool isOperator;
+  bool IsOperator;
   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) {}
+  PrototypeAST(const std::string &Name, std::vector<std::string> Args,
+               bool IsOperator = false, unsigned Prec = 0)
+      : Name(Name), Args(std::move(Args)), IsOperator(IsOperator),
+        Precedence(Prec) {}
+  Function *codegen();
+  const std::string &getName() const { return Name; }
 
-  bool isUnaryOp() const { return isOperator && Args.size() == 1; }
-  bool isBinaryOp() const { return isOperator && Args.size() == 2; }
+  bool isUnaryOp() const { return IsOperator && Args.size() == 1; }
+  bool isBinaryOp() const { return IsOperator && Args.size() == 2; }
 
   char getOperatorName() const {
     assert(isUnaryOp() || isBinaryOp());
@@ -240,21 +248,18 @@ public:
   }
 
   unsigned getBinaryPrecedence() const { return Precedence; }
-
-  Function *Codegen();
-
-  void CreateArgumentAllocas(Function *F);
 };
 
 /// FunctionAST - This class represents a function definition itself.
 class FunctionAST {
-  PrototypeAST *Proto;
-  ExprAST *Body;
+  std::unique_ptr<PrototypeAST> Proto;
+  std::unique_ptr<ExprAST> Body;
 
 public:
-  FunctionAST(PrototypeAST *proto, ExprAST *body) : Proto(proto), Body(body) {}
-
-  Function *Codegen();
+  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
+              std::unique_ptr<ExprAST> Body)
+      : Proto(std::move(Proto)), Body(std::move(Body)) {}
+  Function *codegen();
 };
 } // end anonymous namespace
 
@@ -285,41 +290,58 @@ static int GetTokPrecedence() {
 }
 
 /// Error* - These are little helper functions for error handling.
-ExprAST *Error(const char *Str) {
+std::unique_ptr<ExprAST> Error(const char *Str) {
   fprintf(stderr, "Error: %s\n", Str);
-  return 0;
+  return nullptr;
 }
-PrototypeAST *ErrorP(const char *Str) {
+
+std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
   Error(Str);
-  return 0;
+  return nullptr;
 }
-FunctionAST *ErrorF(const char *Str) {
-  Error(Str);
-  return 0;
+
+static std::unique_ptr<ExprAST> ParseExpression();
+
+/// numberexpr ::= number
+static std::unique_ptr<ExprAST> ParseNumberExpr() {
+  auto Result = llvm::make_unique<NumberExprAST>(NumVal);
+  getNextToken(); // consume the number
+  return std::move(Result);
 }
 
-static ExprAST *ParseExpression();
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+  getNextToken(); // eat (.
+  auto V = ParseExpression();
+  if (!V)
+    return nullptr;
+
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken(); // eat ).
+  return V;
+}
 
 /// identifierexpr
 ///   ::= identifier
 ///   ::= identifier '(' expression* ')'
-static ExprAST *ParseIdentifierExpr() {
+static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
 
   getNextToken(); // eat identifier.
 
   if (CurTok != '(') // Simple variable ref.
-    return new VariableExprAST(IdName);
+    return llvm::make_unique<VariableExprAST>(IdName);
 
   // Call.
   getNextToken(); // eat (
-  std::vector<ExprAST *> Args;
+  std::vector<std::unique_ptr<ExprAST>> Args;
   if (CurTok != ')') {
     while (1) {
-      ExprAST *Arg = ParseExpression();
-      if (!Arg)
-        return 0;
-      Args.push_back(Arg);
+      if (auto Arg = ParseExpression())
+        Args.push_back(std::move(Arg));
+      else
+        return nullptr;
 
       if (CurTok == ')')
         break;
@@ -333,60 +355,41 @@ static ExprAST *ParseIdentifierExpr() {
   // Eat the ')'.
   getNextToken();
 
-  return new CallExprAST(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;
+  return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
 }
 
 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
-static ExprAST *ParseIfExpr() {
+static std::unique_ptr<ExprAST> ParseIfExpr() {
   getNextToken(); // eat the if.
 
   // condition.
-  ExprAST *Cond = ParseExpression();
+  auto Cond = ParseExpression();
   if (!Cond)
-    return 0;
+    return nullptr;
 
   if (CurTok != tok_then)
     return Error("expected then");
   getNextToken(); // eat the then
 
-  ExprAST *Then = ParseExpression();
-  if (Then == 0)
-    return 0;
+  auto Then = ParseExpression();
+  if (!Then)
+    return nullptr;
 
   if (CurTok != tok_else)
     return Error("expected else");
 
   getNextToken();
 
-  ExprAST *Else = ParseExpression();
+  auto Else = ParseExpression();
   if (!Else)
-    return 0;
+    return nullptr;
 
-  return new IfExprAST(Cond, Then, Else);
+  return llvm::make_unique<IfExprAST>(std::move(Cond), std::move(Then),
+                                      std::move(Else));
 }
 
 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
-static ExprAST *ParseForExpr() {
+static std::unique_ptr<ExprAST> ParseForExpr() {
   getNextToken(); // eat the for.
 
   if (CurTok != tok_identifier)
@@ -399,43 +402,44 @@ static ExprAST *ParseForExpr() {
     return Error("expected '=' after for");
   getNextToken(); // eat '='.
 
-  ExprAST *Start = ParseExpression();
-  if (Start == 0)
-    return 0;
+  auto Start = ParseExpression();
+  if (!Start)
+    return nullptr;
   if (CurTok != ',')
     return Error("expected ',' after for start value");
   getNextToken();
 
-  ExprAST *End = ParseExpression();
-  if (End == 0)
-    return 0;
+  auto End = ParseExpression();
+  if (!End)
+    return nullptr;
 
   // The step value is optional.
-  ExprAST *Step = 0;
+  std::unique_ptr<ExprAST> Step;
   if (CurTok == ',') {
     getNextToken();
     Step = ParseExpression();
-    if (Step == 0)
-      return 0;
+    if (!Step)
+      return nullptr;
   }
 
   if (CurTok != tok_in)
     return Error("expected 'in' after for");
   getNextToken(); // eat 'in'.
 
-  ExprAST *Body = ParseExpression();
-  if (Body == 0)
-    return 0;
+  auto Body = ParseExpression();
+  if (!Body)
+    return nullptr;
 
-  return new ForExprAST(IdName, Start, End, Step, Body);
+  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 ExprAST *ParseVarExpr() {
+static std::unique_ptr<ExprAST> ParseVarExpr() {
   getNextToken(); // eat the var.
 
-  std::vector<std::pair<std::string, ExprAST *> > VarNames;
+  std::vector<std::pair<std::string, std::unique_ptr<ExprAST>>> VarNames;
 
   // At least one variable name is required.
   if (CurTok != tok_identifier)
@@ -446,16 +450,16 @@ static ExprAST *ParseVarExpr() {
     getNextToken(); // eat identifier.
 
     // Read the optional initializer.
-    ExprAST *Init = 0;
+    std::unique_ptr<ExprAST> Init = nullptr;
     if (CurTok == '=') {
       getNextToken(); // eat the '='.
 
       Init = ParseExpression();
-      if (Init == 0)
-        return 0;
+      if (!Init)
+        return nullptr;
     }
 
-    VarNames.push_back(std::make_pair(Name, Init));
+    VarNames.push_back(std::make_pair(Name, std::move(Init)));
 
     // End of var list, exit loop.
     if (CurTok != ',')
@@ -471,11 +475,11 @@ static ExprAST *ParseVarExpr() {
     return Error("expected 'in' keyword after 'var'");
   getNextToken(); // eat 'in'.
 
-  ExprAST *Body = ParseExpression();
-  if (Body == 0)
-    return 0;
+  auto Body = ParseExpression();
+  if (!Body)
+    return nullptr;
 
-  return new VarExprAST(VarNames, Body);
+  return llvm::make_unique<VarExprAST>(std::move(VarNames), std::move(Body));
 }
 
 /// primary
@@ -485,7 +489,7 @@ static ExprAST *ParseVarExpr() {
 ///   ::= ifexpr
 ///   ::= forexpr
 ///   ::= varexpr
-static ExprAST *ParsePrimary() {
+static std::unique_ptr<ExprAST> ParsePrimary() {
   switch (CurTok) {
   default:
     return Error("unknown token when expecting an expression");
@@ -507,7 +511,7 @@ static ExprAST *ParsePrimary() {
 /// unary
 ///   ::= primary
 ///   ::= '!' unary
-static ExprAST *ParseUnary() {
+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();
@@ -515,14 +519,15 @@ static ExprAST *ParseUnary() {
   // If this is a unary operator, read it.
   int Opc = CurTok;
   getNextToken();
-  if (ExprAST *Operand = ParseUnary())
-    return new UnaryExprAST(Opc, Operand);
-  return 0;
+  if (auto Operand = ParseUnary())
+    return llvm::make_unique<UnaryExprAST>(Opc, std::move(Operand));
+  return nullptr;
 }
 
 /// binoprhs
 ///   ::= ('+' unary)*
-static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+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();
@@ -537,40 +542,41 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
     getNextToken(); // eat binop
 
     // Parse the unary expression after the binary operator.
-    ExprAST *RHS = ParseUnary();
+    auto RHS = ParseUnary();
     if (!RHS)
-      return 0;
+      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, RHS);
-      if (RHS == 0)
-        return 0;
+      RHS = ParseBinOpRHS(TokPrec + 1, std::move(RHS));
+      if (!RHS)
+        return nullptr;
     }
 
     // Merge LHS/RHS.
-    LHS = new BinaryExprAST(BinOp, LHS, RHS);
+    LHS =
+        llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
   }
 }
 
 /// expression
 ///   ::= unary binoprhs
 ///
-static ExprAST *ParseExpression() {
-  ExprAST *LHS = ParseUnary();
+static std::unique_ptr<ExprAST> ParseExpression() {
+  auto LHS = ParseUnary();
   if (!LHS)
-    return 0;
+    return nullptr;
 
-  return ParseBinOpRHS(0, LHS);
+  return ParseBinOpRHS(0, std::move(LHS));
 }
 
 /// prototype
 ///   ::= id '(' id* ')'
 ///   ::= binary LETTER number? (id, id)
 ///   ::= unary LETTER (id)
-static PrototypeAST *ParsePrototype() {
+static std::unique_ptr<PrototypeAST> ParsePrototype() {
   std::string FnName;
 
   unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
@@ -628,33 +634,35 @@ static PrototypeAST *ParsePrototype() {
   if (Kind && ArgNames.size() != Kind)
     return ErrorP("Invalid number of operands for operator");
 
-  return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
+  return llvm::make_unique<PrototypeAST>(FnName, ArgNames, Kind != 0,
+                                         BinaryPrecedence);
 }
 
 /// definition ::= 'def' prototype expression
-static FunctionAST *ParseDefinition() {
+static std::unique_ptr<FunctionAST> ParseDefinition() {
   getNextToken(); // eat def.
-  PrototypeAST *Proto = ParsePrototype();
-  if (Proto == 0)
-    return 0;
+  auto Proto = ParsePrototype();
+  if (!Proto)
+    return nullptr;
 
-  if (ExprAST *E = ParseExpression())
-    return new FunctionAST(Proto, E);
-  return 0;
+  if (auto E = ParseExpression())
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
+  return nullptr;
 }
 
 /// toplevelexpr ::= expression
-static FunctionAST *ParseTopLevelExpr() {
-  if (ExprAST *E = ParseExpression()) {
+static std::unique_ptr<FunctionAST> ParseTopLevelExpr() {
+  if (auto E = ParseExpression()) {
     // Make an anonymous proto.
-    PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
-    return new FunctionAST(Proto, E);
+    auto Proto = llvm::make_unique<PrototypeAST>("__anon_expr",
+                                                 std::vector<std::string>());
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
   }
-  return 0;
+  return nullptr;
 }
 
 /// external ::= 'extern' prototype
-static PrototypeAST *ParseExtern() {
+static std::unique_ptr<PrototypeAST> ParseExtern() {
   getNextToken(); // eat extern.
   return ParsePrototype();
 }
@@ -663,14 +671,31 @@ static PrototypeAST *ParseExtern() {
 // Code Generation
 //===----------------------------------------------------------------------===//
 
-static Module *TheModule;
+static std::unique_ptr<Module> TheModule;
 static IRBuilder<> Builder(getGlobalContext());
 static std::map<std::string, AllocaInst *> NamedValues;
-static legacy::FunctionPassManager *TheFPM;
+static std::unique_ptr<legacy::FunctionPassManager> TheFPM;
+static std::unique_ptr<KaleidoscopeJIT> TheJIT;
+static std::map<std::string, std::unique_ptr<PrototypeAST>> FunctionProtos;
 
 Value *ErrorV(const char *Str) {
   Error(Str);
-  return 0;
+  return nullptr;
+}
+
+Function *getFunction(std::string Name) {
+  // First, see if the function has already been added to the current module.
+  if (auto *F = TheModule->getFunction(Name))
+    return F;
+
+  // If not, check whether we can codegen the declaration from some existing
+  // prototype.
+  auto FI = FunctionProtos.find(Name);
+  if (FI != FunctionProtos.end())
+    return FI->second->codegen();
+
+  // If no existing prototype exists, return null.
+  return nullptr;
 }
 
 /// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
@@ -679,64 +704,64 @@ static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
                                           const std::string &VarName) {
   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
                    TheFunction->getEntryBlock().begin());
-  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), nullptr,
                            VarName.c_str());
 }
 
-Value *NumberExprAST::Codegen() {
+Value *NumberExprAST::codegen() {
   return ConstantFP::get(getGlobalContext(), APFloat(Val));
 }
 
-Value *VariableExprAST::Codegen() {
+Value *VariableExprAST::codegen() {
   // Look this variable up in the function.
   Value *V = NamedValues[Name];
-  if (V == 0)
+  if (!V)
     return ErrorV("Unknown variable name");
 
   // Load the value.
   return Builder.CreateLoad(V, Name.c_str());
 }
 
-Value *UnaryExprAST::Codegen() {
-  Value *OperandV = Operand->Codegen();
-  if (OperandV == 0)
-    return 0;
+Value *UnaryExprAST::codegen() {
+  Value *OperandV = Operand->codegen();
+  if (!OperandV)
+    return nullptr;
 
-  Function *F = TheModule->getFunction(std::string("unary") + Opcode);
-  if (F == 0)
+  Function *F = getFunction(std::string("unary") + Opcode);
+  if (!F)
     return ErrorV("Unknown unary operator");
 
   return Builder.CreateCall(F, OperandV, "unop");
 }
 
-Value *BinaryExprAST::Codegen() {
+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.
     // This assume we're building without RTTI because LLVM builds that way by
     // default.  If you build LLVM with RTTI this can be changed to a
     // dynamic_cast for automatic error checking.
-    VariableExprAST *LHSE = static_cast<VariableExprAST *>(LHS);
+    VariableExprAST *LHSE = static_cast<VariableExprAST *>(LHS.get());
     if (!LHSE)
       return ErrorV("destination of '=' must be a variable");
     // Codegen the RHS.
-    Value *Val = RHS->Codegen();
-    if (Val == 0)
-      return 0;
+    Value *Val = RHS->codegen();
+    if (!Val)
+      return nullptr;
 
     // Look up the name.
     Value *Variable = NamedValues[LHSE->getName()];
-    if (Variable == 0)
+    if (!Variable)
       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;
+  Value *L = LHS->codegen();
+  Value *R = RHS->codegen();
+  if (!L || !R)
+    return nullptr;
 
   switch (Op) {
   case '+':
@@ -756,17 +781,17 @@ Value *BinaryExprAST::Codegen() {
 
   // 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 = getFunction(std::string("binary") + Op);
   assert(F && "binary operator not found!");
 
-  Value *Ops[] = { L, R };
+  Value *Ops[] = {L, R};
   return Builder.CreateCall(F, Ops, "binop");
 }
 
-Value *CallExprAST::Codegen() {
+Value *CallExprAST::codegen() {
   // Look up the name in the global module table.
-  Function *CalleeF = TheModule->getFunction(Callee);
-  if (CalleeF == 0)
+  Function *CalleeF = getFunction(Callee);
+  if (!CalleeF)
     return ErrorV("Unknown function referenced");
 
   // If argument mismatch error.
@@ -775,18 +800,18 @@ Value *CallExprAST::Codegen() {
 
   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;
+    ArgsV.push_back(Args[i]->codegen());
+    if (!ArgsV.back())
+      return nullptr;
   }
 
   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 }
 
-Value *IfExprAST::Codegen() {
-  Value *CondV = Cond->Codegen();
-  if (CondV == 0)
-    return 0;
+Value *IfExprAST::codegen() {
+  Value *CondV = Cond->codegen();
+  if (!CondV)
+    return nullptr;
 
   // Convert condition to a bool by comparing equal to 0.0.
   CondV = Builder.CreateFCmpONE(
@@ -806,9 +831,9 @@ Value *IfExprAST::Codegen() {
   // Emit then value.
   Builder.SetInsertPoint(ThenBB);
 
-  Value *ThenV = Then->Codegen();
-  if (ThenV == 0)
-    return 0;
+  Value *ThenV = Then->codegen();
+  if (!ThenV)
+    return nullptr;
 
   Builder.CreateBr(MergeBB);
   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
@@ -818,9 +843,9 @@ Value *IfExprAST::Codegen() {
   TheFunction->getBasicBlockList().push_back(ElseBB);
   Builder.SetInsertPoint(ElseBB);
 
-  Value *ElseV = Else->Codegen();
-  if (ElseV == 0)
-    return 0;
+  Value *ElseV = Else->codegen();
+  if (!ElseV)
+    return nullptr;
 
   Builder.CreateBr(MergeBB);
   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
@@ -837,36 +862,35 @@ Value *IfExprAST::Codegen() {
   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:
-
+// Output for-loop 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:
+Value *ForExprAST::codegen() {
   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;
+  Value *StartVal = Start->codegen();
+  if (!StartVal)
+    return nullptr;
 
   // Store the value into the alloca.
   Builder.CreateStore(StartVal, Alloca);
@@ -890,24 +914,24 @@ Value *ForExprAST::Codegen() {
   // 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;
+  if (!Body->codegen())
+    return nullptr;
 
   // Emit the step value.
-  Value *StepVal;
+  Value *StepVal = nullptr;
   if (Step) {
-    StepVal = Step->Codegen();
-    if (StepVal == 0)
-      return 0;
+    StepVal = Step->codegen();
+    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->Codegen();
-  if (EndCond == 0)
-    return EndCond;
+  Value *EndCond = End->codegen();
+  if (!EndCond)
+    return nullptr;
 
   // Reload, increment, and restore the alloca.  This handles the case where
   // the body of the loop mutates the variable.
@@ -939,7 +963,7 @@ Value *ForExprAST::Codegen() {
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
 
-Value *VarExprAST::Codegen() {
+Value *VarExprAST::codegen() {
   std::vector<AllocaInst *> OldBindings;
 
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
@@ -947,7 +971,7 @@ Value *VarExprAST::Codegen() {
   // 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;
+    ExprAST *Init = VarNames[i].second.get();
 
     // Emit the initializer before adding the variable to scope, this prevents
     // the initializer from referencing the variable itself, and permits stuff
@@ -956,9 +980,9 @@ Value *VarExprAST::Codegen() {
     //    var a = a in ...   # refers to outer 'a'.
     Value *InitVal;
     if (Init) {
-      InitVal = Init->Codegen();
-      if (InitVal == 0)
-        return 0;
+      InitVal = Init->codegen();
+      if (!InitVal)
+        return nullptr;
     } else { // If not specified, use 0.0.
       InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
     }
@@ -975,9 +999,9 @@ Value *VarExprAST::Codegen() {
   }
 
   // Codegen the body, now that all vars are in scope.
-  Value *BodyVal = Body->Codegen();
-  if (BodyVal == 0)
-    return 0;
+  Value *BodyVal = Body->codegen();
+  if (!BodyVal)
+    return nullptr;
 
   // Pop all our variables from scope.
   for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
@@ -987,7 +1011,7 @@ Value *VarExprAST::Codegen() {
   return BodyVal;
 }
 
-Function *PrototypeAST::Codegen() {
+Function *PrototypeAST::codegen() {
   // Make the function type:  double(double,double) etc.
   std::vector<Type *> Doubles(Args.size(),
                               Type::getDoubleTy(getGlobalContext()));
@@ -995,79 +1019,54 @@ Function *PrototypeAST::Codegen() {
       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;
-    }
-  }
+      Function::Create(FT, Function::ExternalLinkage, Name, TheModule.get());
 
   // 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]);
+  for (auto &Arg : F->args())
+    Arg.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) {
-  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.
-    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;
+Function *FunctionAST::codegen() {
+  // Transfer ownership of the prototype to the FunctionProtos map, but keep a
+  // reference to it for use below.
+  auto &P = *Proto;
+  FunctionProtos[Proto->getName()] = std::move(Proto);
+  Function *TheFunction = getFunction(P.getName());
+  if (!TheFunction)
+    return nullptr;
 
   // If this is an operator, install it.
-  if (Proto->isBinaryOp())
-    BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
+  if (P.isBinaryOp())
+    BinopPrecedence[P.getOperatorName()] = P.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);
+  // Record the function arguments in the NamedValues map.
+  NamedValues.clear();
+  for (auto &Arg : TheFunction->args()) {
+    // Create an alloca for this variable.
+    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, Arg.getName());
+
+    // Store the initial value into the alloca.
+    Builder.CreateStore(&Arg, Alloca);
+
+    // Add arguments to variable symbol table.
+    NamedValues[Arg.getName()] = Alloca;
+  }
 
-  if (Value *RetVal = Body->Codegen()) {
+  if (Value *RetVal = Body->codegen()) {
     // Finish off the function.
     Builder.CreateRet(RetVal);
 
     // Validate the generated code, checking for consistency.
     verifyFunction(*TheFunction);
 
-    // Optimize the function.
+    // Run the optimizer on the function.
     TheFPM->run(*TheFunction);
 
     return TheFunction;
@@ -1076,22 +1075,42 @@ Function *FunctionAST::Codegen() {
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
 
-  if (Proto->isBinaryOp())
+  if (P.isBinaryOp())
     BinopPrecedence.erase(Proto->getOperatorName());
-  return 0;
+  return nullptr;
 }
 
 //===----------------------------------------------------------------------===//
 // Top-Level parsing and JIT Driver
 //===----------------------------------------------------------------------===//
 
-static ExecutionEngine *TheExecutionEngine;
+static void InitializeModuleAndPassManager() {
+  // Open a new module.
+  TheModule = llvm::make_unique<Module>("my cool jit", getGlobalContext());
+  TheModule->setDataLayout(TheJIT->getTargetMachine().createDataLayout());
+
+  // Create a new pass manager attached to it.
+  TheFPM = llvm::make_unique<legacy::FunctionPassManager>(TheModule.get());
+
+  // Do simple "peephole" optimizations and bit-twiddling optzns.
+  TheFPM->add(createInstructionCombiningPass());
+  // Reassociate expressions.
+  TheFPM->add(createReassociatePass());
+  // Eliminate Common SubExpressions.
+  TheFPM->add(createGVNPass());
+  // Simplify the control flow graph (deleting unreachable blocks, etc).
+  TheFPM->add(createCFGSimplificationPass());
+
+  TheFPM->doInitialization();
+}
 
 static void HandleDefinition() {
-  if (FunctionAST *F = ParseDefinition()) {
-    if (Function *LF = F->Codegen()) {
+  if (auto FnAST = ParseDefinition()) {
+    if (auto *FnIR = FnAST->codegen()) {
       fprintf(stderr, "Read function definition:");
-      LF->dump();
+      FnIR->dump();
+      TheJIT->addModule(std::move(TheModule));
+      InitializeModuleAndPassManager();
     }
   } else {
     // Skip token for error recovery.
@@ -1100,10 +1119,11 @@ static void HandleDefinition() {
 }
 
 static void HandleExtern() {
-  if (PrototypeAST *P = ParseExtern()) {
-    if (Function *F = P->Codegen()) {
+  if (auto ProtoAST = ParseExtern()) {
+    if (auto *FnIR = ProtoAST->codegen()) {
       fprintf(stderr, "Read extern: ");
-      F->dump();
+      FnIR->dump();
+      FunctionProtos[ProtoAST->getName()] = std::move(ProtoAST);
     }
   } else {
     // Skip token for error recovery.
@@ -1113,16 +1133,25 @@ static void HandleExtern() {
 
 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;
+  if (auto FnAST = ParseTopLevelExpr()) {
+    if (FnAST->codegen()) {
+
+      // JIT the module containing the anonymous expression, keeping a handle so
+      // we can free it later.
+      auto H = TheJIT->addModule(std::move(TheModule));
+      InitializeModuleAndPassManager();
+
+      // Search the JIT for the __anon_expr symbol.
+      auto ExprSymbol = TheJIT->findSymbol("__anon_expr");
+      assert(ExprSymbol && "Function not found");
+
+      // Get the symbol's address and 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();
       fprintf(stderr, "Evaluated to %f\n", FP());
+
+      // Delete the anonymous expression module from the JIT.
+      TheJIT->removeModule(H);
     }
   } else {
     // Skip token for error recovery.
@@ -1137,9 +1166,9 @@ static void MainLoop() {
     switch (CurTok) {
     case tok_eof:
       return;
-    case ';':
+    case ';': // ignore top-level semicolons.
       getNextToken();
-      break; // ignore top-level semicolons.
+      break;
     case tok_def:
       HandleDefinition();
       break;
@@ -1159,13 +1188,13 @@ static void MainLoop() {
 
 /// putchard - putchar that takes a double and returns 0.
 extern "C" double putchard(double X) {
-  putchar((char)X);
+  fputc((char)X, stderr);
   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);
+  fprintf(stderr, "%f\n", X);
   return 0;
 }
 
@@ -1177,7 +1206,6 @@ int main() {
   InitializeNativeTarget();
   InitializeNativeTargetAsmPrinter();
   InitializeNativeTargetAsmParser();
-  LLVMContext &Context = getGlobalContext();
 
   // Install standard binary operators.
   // 1 is lowest precedence.
@@ -1191,52 +1219,12 @@ int main() {
   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)
-          .setMCJITMemoryManager(llvm::make_unique<SectionMemoryManager>())
-          .create();
-  if (!TheExecutionEngine) {
-    fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
-    exit(1);
-  }
+  TheJIT = llvm::make_unique<KaleidoscopeJIT>();
 
-  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());
-  // 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());
-
-  OurFPM.doInitialization();
-
-  // Set the global so the code gen can use this.
-  TheFPM = &OurFPM;
+  InitializeModuleAndPassManager();
 
   // Run the main "interpreter loop" now.
   MainLoop();
 
-  TheFPM = 0;
-
-  // Print out all of the generated code.
-  TheModule->dump();
-
   return 0;
 }
diff --git a/examples/Kaleidoscope/Chapter8/CMakeLists.txt b/examples/Kaleidoscope/Chapter8/CMakeLists.txt
index f94ed7436189..d9b5cc421be3 100644
--- a/examples/Kaleidoscope/Chapter8/CMakeLists.txt
+++ b/examples/Kaleidoscope/Chapter8/CMakeLists.txt
@@ -1,8 +1,7 @@
 set(LLVM_LINK_COMPONENTS
   Core
   ExecutionEngine
-  MCJIT
-  RuntimeDyld
+  Object
   Support
   native
   )
@@ -10,3 +9,5 @@ set(LLVM_LINK_COMPONENTS
 add_kaleidoscope_chapter(Kaleidoscope-Ch8
   toy.cpp
   )
+
+export_executable_symbols(Kaleidoscope-Ch8)
diff --git a/examples/Kaleidoscope/Chapter8/toy.cpp b/examples/Kaleidoscope/Chapter8/toy.cpp
index 71bc2f684027..289209b3df49 100644
--- a/examples/Kaleidoscope/Chapter8/toy.cpp
+++ b/examples/Kaleidoscope/Chapter8/toy.cpp
@@ -1,27 +1,23 @@
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/Triple.h"
+#include "llvm/Analysis/BasicAliasAnalysis.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>
+#include "../include/KaleidoscopeJIT.h"
+
 using namespace llvm;
+using namespace llvm::orc;
 
 //===----------------------------------------------------------------------===//
 // Lexer
@@ -96,20 +92,17 @@ 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 SourceLocation LexLoc = {1, 0};
 
 static int advance() {
   int LastChar = getchar();
@@ -122,6 +115,9 @@ static int advance() {
   return LastChar;
 }
 
+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 = ' ';
@@ -167,7 +163,7 @@ static int gettok() {
       LastChar = advance();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -196,7 +192,7 @@ static int gettok() {
 //===----------------------------------------------------------------------===//
 namespace {
 
-std::ostream &indent(std::ostream &O, int size) {
+raw_ostream &indent(raw_ostream &O, int size) {
   return O << std::string(size, ' ');
 }
 
@@ -205,14 +201,14 @@ class ExprAST {
   SourceLocation Loc;
 
 public:
+  ExprAST(SourceLocation Loc = CurLoc) : Loc(Loc) {}
+  virtual ~ExprAST() {}
+  virtual Value *codegen() = 0;
   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) {
+  virtual raw_ostream &dump(raw_ostream &out, int ind) {
     return out << ':' << getLine() << ':' << getCol() << '\n';
   }
-  virtual ~ExprAST() {}
-  virtual Value *Codegen() = 0;
 };
 
 /// NumberExprAST - Expression class for numeric literals like "1.0".
@@ -220,11 +216,11 @@ class NumberExprAST : public ExprAST {
   double Val;
 
 public:
-  NumberExprAST(double val) : Val(val) {}
-  std::ostream &dump(std::ostream &out, int ind) override {
+  NumberExprAST(double Val) : Val(Val) {}
+  raw_ostream &dump(raw_ostream &out, int ind) override {
     return ExprAST::dump(out << Val, ind);
   }
-  Value *Codegen() override;
+  Value *codegen() override;
 };
 
 /// VariableExprAST - Expression class for referencing a variable, like "a".
@@ -232,93 +228,99 @@ class VariableExprAST : public ExprAST {
   std::string Name;
 
 public:
-  VariableExprAST(SourceLocation Loc, const std::string &name)
-      : ExprAST(Loc), Name(name) {}
+  VariableExprAST(SourceLocation Loc, const std::string &Name)
+      : ExprAST(Loc), Name(Name) {}
   const std::string &getName() const { return Name; }
-  std::ostream &dump(std::ostream &out, int ind) override {
+  Value *codegen() override;
+  raw_ostream &dump(raw_ostream &out, int ind) override {
     return ExprAST::dump(out << Name, ind);
   }
-  Value *Codegen() override;
 };
 
 /// UnaryExprAST - Expression class for a unary operator.
 class UnaryExprAST : public ExprAST {
   char Opcode;
-  ExprAST *Operand;
+  std::unique_ptr<ExprAST> Operand;
 
 public:
-  UnaryExprAST(char opcode, ExprAST *operand)
-      : Opcode(opcode), Operand(operand) {}
-  std::ostream &dump(std::ostream &out, int ind) override {
+  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand)
+      : Opcode(Opcode), Operand(std::move(Operand)) {}
+  Value *codegen() override;
+  raw_ostream &dump(raw_ostream &out, int ind) override {
     ExprAST::dump(out << "unary" << Opcode, ind);
     Operand->dump(out, ind + 1);
     return out;
   }
-  Value *Codegen() override;
 };
 
 /// BinaryExprAST - Expression class for a binary operator.
 class BinaryExprAST : public ExprAST {
   char Op;
-  ExprAST *LHS, *RHS;
+  std::unique_ptr<ExprAST> LHS, RHS;
 
 public:
-  BinaryExprAST(SourceLocation Loc, char op, ExprAST *lhs, ExprAST *rhs)
-      : ExprAST(Loc), Op(op), LHS(lhs), RHS(rhs) {}
-  std::ostream &dump(std::ostream &out, int ind) override {
+  BinaryExprAST(SourceLocation Loc, char Op, std::unique_ptr<ExprAST> LHS,
+                std::unique_ptr<ExprAST> RHS)
+      : ExprAST(Loc), Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
+  Value *codegen() override;
+  raw_ostream &dump(raw_ostream &out, int ind) override {
     ExprAST::dump(out << "binary" << Op, ind);
     LHS->dump(indent(out, ind) << "LHS:", ind + 1);
     RHS->dump(indent(out, ind) << "RHS:", ind + 1);
     return out;
   }
-  Value *Codegen() override;
 };
 
 /// CallExprAST - Expression class for function calls.
 class CallExprAST : public ExprAST {
   std::string Callee;
-  std::vector<ExprAST *> Args;
+  std::vector<std::unique_ptr<ExprAST>> Args;
 
 public:
-  CallExprAST(SourceLocation Loc, const std::string &callee,
-              std::vector<ExprAST *> &args)
-      : ExprAST(Loc), Callee(callee), Args(args) {}
-  std::ostream &dump(std::ostream &out, int ind) override {
+  CallExprAST(SourceLocation Loc, const std::string &Callee,
+              std::vector<std::unique_ptr<ExprAST>> Args)
+      : ExprAST(Loc), Callee(Callee), Args(std::move(Args)) {}
+  Value *codegen() override;
+  raw_ostream &dump(raw_ostream &out, int ind) override {
     ExprAST::dump(out << "call " << Callee, ind);
-    for (ExprAST *Arg : Args)
+    for (const auto &Arg : Args)
       Arg->dump(indent(out, ind + 1), ind + 1);
     return out;
   }
-  Value *Codegen() override;
 };
 
 /// IfExprAST - Expression class for if/then/else.
 class IfExprAST : public ExprAST {
-  ExprAST *Cond, *Then, *Else;
+  std::unique_ptr<ExprAST> Cond, Then, Else;
 
 public:
-  IfExprAST(SourceLocation Loc, ExprAST *cond, ExprAST *then, ExprAST *_else)
-      : ExprAST(Loc), Cond(cond), Then(then), Else(_else) {}
-  std::ostream &dump(std::ostream &out, int ind) override {
+  IfExprAST(SourceLocation Loc, std::unique_ptr<ExprAST> Cond,
+            std::unique_ptr<ExprAST> Then, std::unique_ptr<ExprAST> Else)
+      : ExprAST(Loc), Cond(std::move(Cond)), Then(std::move(Then)),
+        Else(std::move(Else)) {}
+  Value *codegen() override;
+  raw_ostream &dump(raw_ostream &out, int ind) override {
     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;
   }
-  Value *Codegen() override;
 };
 
 /// ForExprAST - Expression class for for/in.
 class ForExprAST : public ExprAST {
   std::string VarName;
-  ExprAST *Start, *End, *Step, *Body;
+  std::unique_ptr<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) {}
-  std::ostream &dump(std::ostream &out, int ind) override {
+  ForExprAST(const std::string &VarName, std::unique_ptr<ExprAST> Start,
+             std::unique_ptr<ExprAST> End, std::unique_ptr<ExprAST> Step,
+             std::unique_ptr<ExprAST> Body)
+      : VarName(VarName), Start(std::move(Start)), End(std::move(End)),
+        Step(std::move(Step)), Body(std::move(Body)) {}
+  Value *codegen() override;
+  raw_ostream &dump(raw_ostream &out, int ind) override {
     ExprAST::dump(out << "for", ind);
     Start->dump(indent(out, ind) << "Cond:", ind + 1);
     End->dump(indent(out, ind) << "End:", ind + 1);
@@ -326,47 +328,49 @@ public:
     Body->dump(indent(out, ind) << "Body:", ind + 1);
     return out;
   }
-  Value *Codegen() override;
 };
 
 /// VarExprAST - Expression class for var/in
 class VarExprAST : public ExprAST {
-  std::vector<std::pair<std::string, ExprAST *> > VarNames;
-  ExprAST *Body;
+  std::vector<std::pair<std::string, std::unique_ptr<ExprAST>>> VarNames;
+  std::unique_ptr<ExprAST> Body;
 
 public:
-  VarExprAST(const std::vector<std::pair<std::string, ExprAST *> > &varnames,
-             ExprAST *body)
-      : VarNames(varnames), Body(body) {}
-
-  std::ostream &dump(std::ostream &out, int ind) override {
+  VarExprAST(
+      std::vector<std::pair<std::string, std::unique_ptr<ExprAST>>> VarNames,
+      std::unique_ptr<ExprAST> Body)
+      : VarNames(std::move(VarNames)), Body(std::move(Body)) {}
+  Value *codegen() override;
+  raw_ostream &dump(raw_ostream &out, int ind) override {
     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;
   }
-  Value *Codegen() override;
 };
 
 /// PrototypeAST - This class represents the "prototype" for a function,
-/// which captures its argument names as well as if it is an operator.
+/// which captures its name, and its argument names (thus implicitly the number
+/// of arguments the function takes), as well as if it is an operator.
 class PrototypeAST {
   std::string Name;
   std::vector<std::string> Args;
-  bool isOperator;
+  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) {}
+  PrototypeAST(SourceLocation Loc, const std::string &Name,
+               std::vector<std::string> Args, bool IsOperator = false,
+               unsigned Prec = 0)
+      : Name(Name), Args(std::move(Args)), IsOperator(IsOperator),
+        Precedence(Prec), Line(Loc.Line) {}
+  Function *codegen();
+  const std::string &getName() const { return Name; }
 
-  bool isUnaryOp() const { return isOperator && Args.size() == 1; }
-  bool isBinaryOp() const { return isOperator && Args.size() == 2; }
+  bool isUnaryOp() const { return IsOperator && Args.size() == 1; }
+  bool isBinaryOp() const { return IsOperator && Args.size() == 2; }
 
   char getOperatorName() const {
     assert(isUnaryOp() || isBinaryOp());
@@ -374,29 +378,25 @@ public:
   }
 
   unsigned getBinaryPrecedence() const { return Precedence; }
-
-  Function *Codegen();
-
-  void CreateArgumentAllocas(Function *F);
-  const std::vector<std::string> &getArgs() const { return Args; }
+  int getLine() const { return Line; }
 };
 
 /// FunctionAST - This class represents a function definition itself.
 class FunctionAST {
-  PrototypeAST *Proto;
-  ExprAST *Body;
+  std::unique_ptr<PrototypeAST> Proto;
+  std::unique_ptr<ExprAST> Body;
 
 public:
-  FunctionAST(PrototypeAST *proto, ExprAST *body) : Proto(proto), Body(body) {}
-
-  std::ostream &dump(std::ostream &out, int ind) {
+  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
+              std::unique_ptr<ExprAST> Body)
+      : Proto(std::move(Proto)), Body(std::move(Body)) {}
+  Function *codegen();
+  raw_ostream &dump(raw_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
 
@@ -427,25 +427,42 @@ static int GetTokPrecedence() {
 }
 
 /// Error* - These are little helper functions for error handling.
-ExprAST *Error(const char *Str) {
+std::unique_ptr<ExprAST> Error(const char *Str) {
   fprintf(stderr, "Error: %s\n", Str);
-  return 0;
+  return nullptr;
 }
-PrototypeAST *ErrorP(const char *Str) {
+
+std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
   Error(Str);
-  return 0;
+  return nullptr;
 }
-FunctionAST *ErrorF(const char *Str) {
-  Error(Str);
-  return 0;
+
+static std::unique_ptr<ExprAST> ParseExpression();
+
+/// numberexpr ::= number
+static std::unique_ptr<ExprAST> ParseNumberExpr() {
+  auto Result = llvm::make_unique<NumberExprAST>(NumVal);
+  getNextToken(); // consume the number
+  return std::move(Result);
 }
 
-static ExprAST *ParseExpression();
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+  getNextToken(); // eat (.
+  auto V = ParseExpression();
+  if (!V)
+    return nullptr;
+
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken(); // eat ).
+  return V;
+}
 
 /// identifierexpr
 ///   ::= identifier
 ///   ::= identifier '(' expression* ')'
-static ExprAST *ParseIdentifierExpr() {
+static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
   std::string IdName = IdentifierStr;
 
   SourceLocation LitLoc = CurLoc;
@@ -453,17 +470,17 @@ static ExprAST *ParseIdentifierExpr() {
   getNextToken(); // eat identifier.
 
   if (CurTok != '(') // Simple variable ref.
-    return new VariableExprAST(LitLoc, IdName);
+    return llvm::make_unique<VariableExprAST>(LitLoc, IdName);
 
   // Call.
   getNextToken(); // eat (
-  std::vector<ExprAST *> Args;
+  std::vector<std::unique_ptr<ExprAST>> Args;
   if (CurTok != ')') {
     while (1) {
-      ExprAST *Arg = ParseExpression();
-      if (!Arg)
-        return 0;
-      Args.push_back(Arg);
+      if (auto Arg = ParseExpression())
+        Args.push_back(std::move(Arg));
+      else
+        return nullptr;
 
       if (CurTok == ')')
         break;
@@ -477,62 +494,43 @@ static ExprAST *ParseIdentifierExpr() {
   // 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;
+  return llvm::make_unique<CallExprAST>(LitLoc, IdName, std::move(Args));
 }
 
 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
-static ExprAST *ParseIfExpr() {
+static std::unique_ptr<ExprAST> ParseIfExpr() {
   SourceLocation IfLoc = CurLoc;
 
   getNextToken(); // eat the if.
 
   // condition.
-  ExprAST *Cond = ParseExpression();
+  auto Cond = ParseExpression();
   if (!Cond)
-    return 0;
+    return nullptr;
 
   if (CurTok != tok_then)
     return Error("expected then");
   getNextToken(); // eat the then
 
-  ExprAST *Then = ParseExpression();
-  if (Then == 0)
-    return 0;
+  auto Then = ParseExpression();
+  if (!Then)
+    return nullptr;
 
   if (CurTok != tok_else)
     return Error("expected else");
 
   getNextToken();
 
-  ExprAST *Else = ParseExpression();
+  auto Else = ParseExpression();
   if (!Else)
-    return 0;
+    return nullptr;
 
-  return new IfExprAST(IfLoc, Cond, Then, Else);
+  return llvm::make_unique<IfExprAST>(IfLoc, std::move(Cond), std::move(Then),
+                                      std::move(Else));
 }
 
 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
-static ExprAST *ParseForExpr() {
+static std::unique_ptr<ExprAST> ParseForExpr() {
   getNextToken(); // eat the for.
 
   if (CurTok != tok_identifier)
@@ -545,43 +543,44 @@ static ExprAST *ParseForExpr() {
     return Error("expected '=' after for");
   getNextToken(); // eat '='.
 
-  ExprAST *Start = ParseExpression();
-  if (Start == 0)
-    return 0;
+  auto Start = ParseExpression();
+  if (!Start)
+    return nullptr;
   if (CurTok != ',')
     return Error("expected ',' after for start value");
   getNextToken();
 
-  ExprAST *End = ParseExpression();
-  if (End == 0)
-    return 0;
+  auto End = ParseExpression();
+  if (!End)
+    return nullptr;
 
   // The step value is optional.
-  ExprAST *Step = 0;
+  std::unique_ptr<ExprAST> Step;
   if (CurTok == ',') {
     getNextToken();
     Step = ParseExpression();
-    if (Step == 0)
-      return 0;
+    if (!Step)
+      return nullptr;
   }
 
   if (CurTok != tok_in)
     return Error("expected 'in' after for");
   getNextToken(); // eat 'in'.
 
-  ExprAST *Body = ParseExpression();
-  if (Body == 0)
-    return 0;
+  auto Body = ParseExpression();
+  if (!Body)
+    return nullptr;
 
-  return new ForExprAST(IdName, Start, End, Step, Body);
+  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 ExprAST *ParseVarExpr() {
+static std::unique_ptr<ExprAST> ParseVarExpr() {
   getNextToken(); // eat the var.
 
-  std::vector<std::pair<std::string, ExprAST *> > VarNames;
+  std::vector<std::pair<std::string, std::unique_ptr<ExprAST>>> VarNames;
 
   // At least one variable name is required.
   if (CurTok != tok_identifier)
@@ -592,16 +591,16 @@ static ExprAST *ParseVarExpr() {
     getNextToken(); // eat identifier.
 
     // Read the optional initializer.
-    ExprAST *Init = 0;
+    std::unique_ptr<ExprAST> Init = nullptr;
     if (CurTok == '=') {
       getNextToken(); // eat the '='.
 
       Init = ParseExpression();
-      if (Init == 0)
-        return 0;
+      if (!Init)
+        return nullptr;
     }
 
-    VarNames.push_back(std::make_pair(Name, Init));
+    VarNames.push_back(std::make_pair(Name, std::move(Init)));
 
     // End of var list, exit loop.
     if (CurTok != ',')
@@ -617,11 +616,11 @@ static ExprAST *ParseVarExpr() {
     return Error("expected 'in' keyword after 'var'");
   getNextToken(); // eat 'in'.
 
-  ExprAST *Body = ParseExpression();
-  if (Body == 0)
-    return 0;
+  auto Body = ParseExpression();
+  if (!Body)
+    return nullptr;
 
-  return new VarExprAST(VarNames, Body);
+  return llvm::make_unique<VarExprAST>(std::move(VarNames), std::move(Body));
 }
 
 /// primary
@@ -631,7 +630,7 @@ static ExprAST *ParseVarExpr() {
 ///   ::= ifexpr
 ///   ::= forexpr
 ///   ::= varexpr
-static ExprAST *ParsePrimary() {
+static std::unique_ptr<ExprAST> ParsePrimary() {
   switch (CurTok) {
   default:
     return Error("unknown token when expecting an expression");
@@ -653,7 +652,7 @@ static ExprAST *ParsePrimary() {
 /// unary
 ///   ::= primary
 ///   ::= '!' unary
-static ExprAST *ParseUnary() {
+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();
@@ -661,14 +660,15 @@ static ExprAST *ParseUnary() {
   // If this is a unary operator, read it.
   int Opc = CurTok;
   getNextToken();
-  if (ExprAST *Operand = ParseUnary())
-    return new UnaryExprAST(Opc, Operand);
-  return 0;
+  if (auto Operand = ParseUnary())
+    return llvm::make_unique<UnaryExprAST>(Opc, std::move(Operand));
+  return nullptr;
 }
 
 /// binoprhs
 ///   ::= ('+' unary)*
-static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+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();
@@ -684,40 +684,41 @@ static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
     getNextToken(); // eat binop
 
     // Parse the unary expression after the binary operator.
-    ExprAST *RHS = ParseUnary();
+    auto RHS = ParseUnary();
     if (!RHS)
-      return 0;
+      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, RHS);
-      if (RHS == 0)
-        return 0;
+      RHS = ParseBinOpRHS(TokPrec + 1, std::move(RHS));
+      if (!RHS)
+        return nullptr;
     }
 
     // Merge LHS/RHS.
-    LHS = new BinaryExprAST(BinLoc, BinOp, LHS, RHS);
+    LHS = llvm::make_unique<BinaryExprAST>(BinLoc, BinOp, std::move(LHS),
+                                           std::move(RHS));
   }
 }
 
 /// expression
 ///   ::= unary binoprhs
 ///
-static ExprAST *ParseExpression() {
-  ExprAST *LHS = ParseUnary();
+static std::unique_ptr<ExprAST> ParseExpression() {
+  auto LHS = ParseUnary();
   if (!LHS)
-    return 0;
+    return nullptr;
 
-  return ParseBinOpRHS(0, LHS);
+  return ParseBinOpRHS(0, std::move(LHS));
 }
 
 /// prototype
 ///   ::= id '(' id* ')'
 ///   ::= binary LETTER number? (id, id)
 ///   ::= unary LETTER (id)
-static PrototypeAST *ParsePrototype() {
+static std::unique_ptr<PrototypeAST> ParsePrototype() {
   std::string FnName;
 
   SourceLocation FnLoc = CurLoc;
@@ -777,35 +778,36 @@ static PrototypeAST *ParsePrototype() {
   if (Kind && ArgNames.size() != Kind)
     return ErrorP("Invalid number of operands for operator");
 
-  return new PrototypeAST(FnLoc, FnName, ArgNames, Kind != 0, BinaryPrecedence);
+  return llvm::make_unique<PrototypeAST>(FnLoc, FnName, ArgNames, Kind != 0,
+                                         BinaryPrecedence);
 }
 
 /// definition ::= 'def' prototype expression
-static FunctionAST *ParseDefinition() {
+static std::unique_ptr<FunctionAST> ParseDefinition() {
   getNextToken(); // eat def.
-  PrototypeAST *Proto = ParsePrototype();
-  if (Proto == 0)
-    return 0;
+  auto Proto = ParsePrototype();
+  if (!Proto)
+    return nullptr;
 
-  if (ExprAST *E = ParseExpression())
-    return new FunctionAST(Proto, E);
-  return 0;
+  if (auto E = ParseExpression())
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
+  return nullptr;
 }
 
 /// toplevelexpr ::= expression
-static FunctionAST *ParseTopLevelExpr() {
+static std::unique_ptr<FunctionAST> ParseTopLevelExpr() {
   SourceLocation FnLoc = CurLoc;
-  if (ExprAST *E = ParseExpression()) {
+  if (auto E = ParseExpression()) {
     // Make an anonymous proto.
-    PrototypeAST *Proto =
-        new PrototypeAST(FnLoc, "main", std::vector<std::string>());
-    return new FunctionAST(Proto, E);
+    auto Proto = llvm::make_unique<PrototypeAST>(FnLoc, "__anon_expr",
+                                                 std::vector<std::string>());
+    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
   }
-  return 0;
+  return nullptr;
 }
 
 /// external ::= 'extern' prototype
-static PrototypeAST *ParseExtern() {
+static std::unique_ptr<PrototypeAST> ParseExtern() {
   getNextToken(); // eat extern.
   return ParsePrototype();
 }
@@ -814,7 +816,7 @@ static PrototypeAST *ParseExtern() {
 // Debug Info Support
 //===----------------------------------------------------------------------===//
 
-static DIBuilder *DBuilder;
+static std::unique_ptr<DIBuilder> DBuilder;
 
 DIType *DebugInfo::getDoubleTy() {
   if (DblTy)
@@ -846,21 +848,36 @@ static DISubroutineType *CreateFunctionType(unsigned NumArgs, DIFile *Unit) {
   for (unsigned i = 0, e = NumArgs; i != e; ++i)
     EltTys.push_back(DblTy);
 
-  return DBuilder->createSubroutineType(Unit,
-                                        DBuilder->getOrCreateTypeArray(EltTys));
+  return DBuilder->createSubroutineType(DBuilder->getOrCreateTypeArray(EltTys));
 }
 
 //===----------------------------------------------------------------------===//
 // Code Generation
 //===----------------------------------------------------------------------===//
 
-static Module *TheModule;
+static std::unique_ptr<Module> TheModule;
 static std::map<std::string, AllocaInst *> NamedValues;
-static legacy::FunctionPassManager *TheFPM;
+static std::unique_ptr<KaleidoscopeJIT> TheJIT;
+static std::map<std::string, std::unique_ptr<PrototypeAST>> FunctionProtos;
 
 Value *ErrorV(const char *Str) {
   Error(Str);
-  return 0;
+  return nullptr;
+}
+
+Function *getFunction(std::string Name) {
+  // First, see if the function has already been added to the current module.
+  if (auto *F = TheModule->getFunction(Name))
+    return F;
+
+  // If not, check whether we can codegen the declaration from some existing
+  // prototype.
+  auto FI = FunctionProtos.find(Name);
+  if (FI != FunctionProtos.end())
+    return FI->second->codegen();
+
+  // If no existing prototype exists, return null.
+  return nullptr;
 }
 
 /// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
@@ -869,19 +886,19 @@ static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
                                           const std::string &VarName) {
   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
                    TheFunction->getEntryBlock().begin());
-  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), nullptr,
                            VarName.c_str());
 }
 
-Value *NumberExprAST::Codegen() {
+Value *NumberExprAST::codegen() {
   KSDbgInfo.emitLocation(this);
   return ConstantFP::get(getGlobalContext(), APFloat(Val));
 }
 
-Value *VariableExprAST::Codegen() {
+Value *VariableExprAST::codegen() {
   // Look this variable up in the function.
   Value *V = NamedValues[Name];
-  if (V == 0)
+  if (!V)
     return ErrorV("Unknown variable name");
 
   KSDbgInfo.emitLocation(this);
@@ -889,20 +906,20 @@ Value *VariableExprAST::Codegen() {
   return Builder.CreateLoad(V, Name.c_str());
 }
 
-Value *UnaryExprAST::Codegen() {
-  Value *OperandV = Operand->Codegen();
-  if (OperandV == 0)
-    return 0;
+Value *UnaryExprAST::codegen() {
+  Value *OperandV = Operand->codegen();
+  if (!OperandV)
+    return nullptr;
 
-  Function *F = TheModule->getFunction(std::string("unary") + Opcode);
-  if (F == 0)
+  Function *F = getFunction(std::string("unary") + Opcode);
+  if (!F)
     return ErrorV("Unknown unary operator");
 
   KSDbgInfo.emitLocation(this);
   return Builder.CreateCall(F, OperandV, "unop");
 }
 
-Value *BinaryExprAST::Codegen() {
+Value *BinaryExprAST::codegen() {
   KSDbgInfo.emitLocation(this);
 
   // Special case '=' because we don't want to emit the LHS as an expression.
@@ -911,27 +928,27 @@ Value *BinaryExprAST::Codegen() {
     // This assume we're building without RTTI because LLVM builds that way by
     // default.  If you build LLVM with RTTI this can be changed to a
     // dynamic_cast for automatic error checking.
-    VariableExprAST *LHSE = static_cast<VariableExprAST *>(LHS);
+    VariableExprAST *LHSE = static_cast<VariableExprAST *>(LHS.get());
     if (!LHSE)
       return ErrorV("destination of '=' must be a variable");
     // Codegen the RHS.
-    Value *Val = RHS->Codegen();
-    if (Val == 0)
-      return 0;
+    Value *Val = RHS->codegen();
+    if (!Val)
+      return nullptr;
 
     // Look up the name.
     Value *Variable = NamedValues[LHSE->getName()];
-    if (Variable == 0)
+    if (!Variable)
       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;
+  Value *L = LHS->codegen();
+  Value *R = RHS->codegen();
+  if (!L || !R)
+    return nullptr;
 
   switch (Op) {
   case '+':
@@ -951,19 +968,19 @@ Value *BinaryExprAST::Codegen() {
 
   // 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 = getFunction(std::string("binary") + Op);
   assert(F && "binary operator not found!");
 
-  Value *Ops[] = { L, R };
+  Value *Ops[] = {L, R};
   return Builder.CreateCall(F, Ops, "binop");
 }
 
-Value *CallExprAST::Codegen() {
+Value *CallExprAST::codegen() {
   KSDbgInfo.emitLocation(this);
 
   // Look up the name in the global module table.
-  Function *CalleeF = TheModule->getFunction(Callee);
-  if (CalleeF == 0)
+  Function *CalleeF = getFunction(Callee);
+  if (!CalleeF)
     return ErrorV("Unknown function referenced");
 
   // If argument mismatch error.
@@ -972,20 +989,20 @@ Value *CallExprAST::Codegen() {
 
   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;
+    ArgsV.push_back(Args[i]->codegen());
+    if (!ArgsV.back())
+      return nullptr;
   }
 
   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 }
 
-Value *IfExprAST::Codegen() {
+Value *IfExprAST::codegen() {
   KSDbgInfo.emitLocation(this);
 
-  Value *CondV = Cond->Codegen();
-  if (CondV == 0)
-    return 0;
+  Value *CondV = Cond->codegen();
+  if (!CondV)
+    return nullptr;
 
   // Convert condition to a bool by comparing equal to 0.0.
   CondV = Builder.CreateFCmpONE(
@@ -1005,9 +1022,9 @@ Value *IfExprAST::Codegen() {
   // Emit then value.
   Builder.SetInsertPoint(ThenBB);
 
-  Value *ThenV = Then->Codegen();
-  if (ThenV == 0)
-    return 0;
+  Value *ThenV = Then->codegen();
+  if (!ThenV)
+    return nullptr;
 
   Builder.CreateBr(MergeBB);
   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
@@ -1017,9 +1034,9 @@ Value *IfExprAST::Codegen() {
   TheFunction->getBasicBlockList().push_back(ElseBB);
   Builder.SetInsertPoint(ElseBB);
 
-  Value *ElseV = Else->Codegen();
-  if (ElseV == 0)
-    return 0;
+  Value *ElseV = Else->codegen();
+  if (!ElseV)
+    return nullptr;
 
   Builder.CreateBr(MergeBB);
   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
@@ -1036,27 +1053,26 @@ Value *IfExprAST::Codegen() {
   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:
-
+// Output for-loop 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:
+Value *ForExprAST::codegen() {
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 
   // Create an alloca for the variable in the entry block.
@@ -1065,9 +1081,9 @@ Value *ForExprAST::Codegen() {
   KSDbgInfo.emitLocation(this);
 
   // Emit the start code first, without 'variable' in scope.
-  Value *StartVal = Start->Codegen();
-  if (StartVal == 0)
-    return 0;
+  Value *StartVal = Start->codegen();
+  if (!StartVal)
+    return nullptr;
 
   // Store the value into the alloca.
   Builder.CreateStore(StartVal, Alloca);
@@ -1091,24 +1107,24 @@ Value *ForExprAST::Codegen() {
   // 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;
+  if (!Body->codegen())
+    return nullptr;
 
   // Emit the step value.
-  Value *StepVal;
+  Value *StepVal = nullptr;
   if (Step) {
-    StepVal = Step->Codegen();
-    if (StepVal == 0)
-      return 0;
+    StepVal = Step->codegen();
+    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->Codegen();
-  if (EndCond == 0)
-    return EndCond;
+  Value *EndCond = End->codegen();
+  if (!EndCond)
+    return nullptr;
 
   // Reload, increment, and restore the alloca.  This handles the case where
   // the body of the loop mutates the variable.
@@ -1140,7 +1156,7 @@ Value *ForExprAST::Codegen() {
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
 
-Value *VarExprAST::Codegen() {
+Value *VarExprAST::codegen() {
   std::vector<AllocaInst *> OldBindings;
 
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
@@ -1148,7 +1164,7 @@ Value *VarExprAST::Codegen() {
   // 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;
+    ExprAST *Init = VarNames[i].second.get();
 
     // Emit the initializer before adding the variable to scope, this prevents
     // the initializer from referencing the variable itself, and permits stuff
@@ -1157,9 +1173,9 @@ Value *VarExprAST::Codegen() {
     //    var a = a in ...   # refers to outer 'a'.
     Value *InitVal;
     if (Init) {
-      InitVal = Init->Codegen();
-      if (InitVal == 0)
-        return 0;
+      InitVal = Init->codegen();
+      if (!InitVal)
+        return nullptr;
     } else { // If not specified, use 0.0.
       InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
     }
@@ -1178,9 +1194,9 @@ Value *VarExprAST::Codegen() {
   KSDbgInfo.emitLocation(this);
 
   // Codegen the body, now that all vars are in scope.
-  Value *BodyVal = Body->Codegen();
-  if (BodyVal == 0)
-    return 0;
+  Value *BodyVal = Body->codegen();
+  if (!BodyVal)
+    return nullptr;
 
   // Pop all our variables from scope.
   for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
@@ -1190,7 +1206,7 @@ Value *VarExprAST::Codegen() {
   return BodyVal;
 }
 
-Function *PrototypeAST::Codegen() {
+Function *PrototypeAST::codegen() {
   // Make the function type:  double(double,double) etc.
   std::vector<Type *> Doubles(Args.size(),
                               Type::getDoubleTy(getGlobalContext()));
@@ -1198,106 +1214,80 @@ Function *PrototypeAST::Codegen() {
       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;
-    }
-  }
+      Function::Create(FT, Function::ExternalLinkage, Name, TheModule.get());
 
   // 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]);
+  for (auto &Arg : F->args())
+    Arg.setName(Args[Idx++]);
+
+  return F;
+}
+
+Function *FunctionAST::codegen() {
+  // Transfer ownership of the prototype to the FunctionProtos map, but keep a
+  // reference to it for use below.
+  auto &P = *Proto;
+  FunctionProtos[Proto->getName()] = std::move(Proto);
+  Function *TheFunction = getFunction(P.getName());
+  if (!TheFunction)
+    return nullptr;
+
+  // If this is an operator, install it.
+  if (P.isBinaryOp())
+    BinopPrecedence[P.getOperatorName()] = P.getBinaryPrecedence();
+
+  // Create a new basic block to start insertion into.
+  BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
+  Builder.SetInsertPoint(BB);
 
   // Create a subprogram DIE for this function.
   DIFile *Unit = DBuilder->createFile(KSDbgInfo.TheCU->getFilename(),
                                       KSDbgInfo.TheCU->getDirectory());
   DIScope *FContext = Unit;
-  unsigned LineNo = Line;
-  unsigned ScopeLine = Line;
+  unsigned LineNo = P.getLine();
+  unsigned ScopeLine = LineNo;
   DISubprogram *SP = DBuilder->createFunction(
-      FContext, Name, StringRef(), Unit, LineNo,
-      CreateFunctionType(Args.size(), Unit), false /* internal linkage */,
-      true /* definition */, ScopeLine, DINode::FlagPrototyped, false, F);
+      FContext, P.getName(), StringRef(), Unit, LineNo,
+      CreateFunctionType(TheFunction->arg_size(), Unit),
+      false /* internal linkage */, true /* definition */, ScopeLine,
+      DINode::FlagPrototyped, false);
+  TheFunction->setSubprogram(SP);
 
-  KSDbgInfo.FnScopeMap[this] = SP;
-  return F;
-}
+  // Push the current scope.
+  KSDbgInfo.LexicalBlocks.push_back(SP);
+
+  // 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);
 
-/// 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) {
+  // Record the function arguments in the NamedValues map.
+  NamedValues.clear();
+  unsigned ArgIdx = 0;
+  for (auto &Arg : TheFunction->args()) {
     // Create an alloca for this variable.
-    AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
+    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, Arg.getName());
 
     // Create a debug descriptor for the variable.
-    DIScope *Scope = KSDbgInfo.LexicalBlocks.back();
-    DIFile *Unit = DBuilder->createFile(KSDbgInfo.TheCU->getFilename(),
-                                        KSDbgInfo.TheCU->getDirectory());
-    DILocalVariable *D = DBuilder->createLocalVariable(
-        dwarf::DW_TAG_arg_variable, Scope, Args[Idx], Unit, Line,
-        KSDbgInfo.getDoubleTy(), Idx);
+    DILocalVariable *D = DBuilder->createParameterVariable(
+        SP, Arg.getName(), ++ArgIdx, Unit, LineNo, KSDbgInfo.getDoubleTy(),
+        true);
 
     DBuilder->insertDeclare(Alloca, D, DBuilder->createExpression(),
-                            DebugLoc::get(Line, 0, Scope),
+                            DebugLoc::get(LineNo, 0, SP),
                             Builder.GetInsertBlock());
 
     // Store the initial value into the alloca.
-    Builder.CreateStore(AI, Alloca);
+    Builder.CreateStore(&Arg, Alloca);
 
     // Add arguments to variable symbol table.
-    NamedValues[Args[Idx]] = Alloca;
+    NamedValues[Arg.getName()] = Alloca;
   }
-}
 
-Function *FunctionAST::Codegen() {
-  NamedValues.clear();
+  KSDbgInfo.emitLocation(Body.get());
 
-  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()) {
+  if (Value *RetVal = Body->codegen()) {
     // Finish off the function.
     Builder.CreateRet(RetVal);
 
@@ -1307,36 +1297,36 @@ 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();
 
-  if (Proto->isBinaryOp())
+  if (P.isBinaryOp())
     BinopPrecedence.erase(Proto->getOperatorName());
 
   // Pop off the lexical block for the function since we added it
   // unconditionally.
   KSDbgInfo.LexicalBlocks.pop_back();
 
-  return 0;
+  return nullptr;
 }
 
 //===----------------------------------------------------------------------===//
 // Top-Level parsing and JIT Driver
 //===----------------------------------------------------------------------===//
 
-static ExecutionEngine *TheExecutionEngine;
+static void InitializeModule() {
+  // Open a new module.
+  TheModule = llvm::make_unique<Module>("my cool jit", getGlobalContext());
+  TheModule->setDataLayout(TheJIT->getTargetMachine().createDataLayout());
+}
 
 static void HandleDefinition() {
-  if (FunctionAST *F = ParseDefinition()) {
-    if (!F->Codegen()) {
+  if (auto FnAST = ParseDefinition()) {
+    if (!FnAST->codegen())
       fprintf(stderr, "Error reading function definition:");
-    }
   } else {
     // Skip token for error recovery.
     getNextToken();
@@ -1344,10 +1334,11 @@ static void HandleDefinition() {
 }
 
 static void HandleExtern() {
-  if (PrototypeAST *P = ParseExtern()) {
-    if (!P->Codegen()) {
+  if (auto ProtoAST = ParseExtern()) {
+    if (!ProtoAST->codegen())
       fprintf(stderr, "Error reading extern");
-    }
+    else
+      FunctionProtos[ProtoAST->getName()] = std::move(ProtoAST);
   } else {
     // Skip token for error recovery.
     getNextToken();
@@ -1356,8 +1347,8 @@ static void HandleExtern() {
 
 static void HandleTopLevelExpression() {
   // Evaluate a top-level expression into an anonymous function.
-  if (FunctionAST *F = ParseTopLevelExpr()) {
-    if (!F->Codegen()) {
+  if (auto FnAST = ParseTopLevelExpr()) {
+    if (!FnAST->codegen()) {
       fprintf(stderr, "Error generating code for top level expr");
     }
   } else {
@@ -1372,9 +1363,9 @@ static void MainLoop() {
     switch (CurTok) {
     case tok_eof:
       return;
-    case ';':
+    case ';': // ignore top-level semicolons.
       getNextToken();
-      break; // ignore top-level semicolons.
+      break;
     case tok_def:
       HandleDefinition();
       break;
@@ -1394,13 +1385,13 @@ static void MainLoop() {
 
 /// putchard - putchar that takes a double and returns 0.
 extern "C" double putchard(double X) {
-  putchar((char)X);
+  fputc((char)X, stderr);
   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);
+  fprintf(stderr, "%f\n", X);
   return 0;
 }
 
@@ -1412,7 +1403,6 @@ int main() {
   InitializeNativeTarget();
   InitializeNativeTargetAsmPrinter();
   InitializeNativeTargetAsmParser();
-  LLVMContext &Context = getGlobalContext();
 
   // Install standard binary operators.
   // 1 is lowest precedence.
@@ -1425,9 +1415,9 @@ int main() {
   // 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();
+  TheJIT = llvm::make_unique<KaleidoscopeJIT>();
+
+  InitializeModule();
 
   // Add the current debug info version into the module.
   TheModule->addModuleFlag(Module::Warning, "Debug Info Version",
@@ -1438,7 +1428,7 @@ int main() {
     TheModule->addModuleFlag(llvm::Module::Warning, "Dwarf Version", 2);
 
   // Construct the DIBuilder, we do this here because we need the module.
-  DBuilder = new DIBuilder(*TheModule);
+  DBuilder = llvm::make_unique<DIBuilder>(*TheModule);
 
   // Create the compile unit for the module.
   // Currently down as "fib.ks" as a filename since we're redirecting stdin
@@ -1446,47 +1436,9 @@ int main() {
   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());
-#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();
 
diff --git a/examples/Kaleidoscope/Orc/fully_lazy/toy.cpp b/examples/Kaleidoscope/Orc/fully_lazy/toy.cpp
index c9b2c6af5658..78184f5d32cd 100644
--- a/examples/Kaleidoscope/Orc/fully_lazy/toy.cpp
+++ b/examples/Kaleidoscope/Orc/fully_lazy/toy.cpp
@@ -39,14 +39,14 @@ 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
 };
@@ -87,7 +87,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -95,11 +95,11 @@ 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;
@@ -140,7 +140,7 @@ struct VariableExprAST : public ExprAST {
 
 /// UnaryExprAST - Expression class for a unary operator.
 struct UnaryExprAST : public ExprAST {
-  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand) 
+  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand)
     : Opcode(std::move(Opcode)), Operand(std::move(Operand)) {}
 
   Value *IRGen(IRGenContext &C) const override;
@@ -152,7 +152,7 @@ struct UnaryExprAST : public ExprAST {
 /// BinaryExprAST - Expression class for a binary operator.
 struct BinaryExprAST : public ExprAST {
   BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
-                std::unique_ptr<ExprAST> RHS) 
+                std::unique_ptr<ExprAST> RHS)
     : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
 
   Value *IRGen(IRGenContext &C) const override;
@@ -224,7 +224,7 @@ struct PrototypeAST {
 
   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];
@@ -268,7 +268,7 @@ 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;
@@ -294,12 +294,12 @@ static std::unique_ptr<ExprAST> ParseExpression();
 ///   ::= 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;
@@ -319,7 +319,7 @@ static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
 
   // Eat the ')'.
   getNextToken();
-  
+
   return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
 }
 
@@ -336,7 +336,7 @@ static std::unique_ptr<ExprAST> ParseParenExpr() {
   auto V = ParseExpression();
   if (!V)
     return nullptr;
-  
+
   if (CurTok != ')')
     return ErrorU<ExprAST>("expected ')'");
   getNextToken();  // eat ).
@@ -346,29 +346,29 @@ static std::unique_ptr<ExprAST> ParseParenExpr() {
 /// 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));
 }
@@ -379,26 +379,25 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
 
   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 == ',') {
@@ -407,11 +406,11 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
     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;
@@ -420,7 +419,7 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
                                        std::move(Step), std::move(Body));
 }
 
-/// varexpr ::= 'var' identifier ('=' expression)? 
+/// varexpr ::= 'var' identifier ('=' expression)?
 //                    (',' identifier ('=' expression)?)* 'in' expression
 static std::unique_ptr<VarExprAST> ParseVarExpr() {
   getNextToken();  // eat the var.
@@ -430,7 +429,7 @@ static std::unique_ptr<VarExprAST> ParseVarExpr() {
   // 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.
@@ -439,31 +438,31 @@ static std::unique_ptr<VarExprAST> ParseVarExpr() {
     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));
 }
 
@@ -493,7 +492,7 @@ 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();
@@ -509,21 +508,21 @@ static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
   // 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();
@@ -532,7 +531,7 @@ static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
       if (!RHS)
         return nullptr;
     }
-    
+
     // Merge LHS/RHS.
     LHS = llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
   }
@@ -545,7 +544,7 @@ static std::unique_ptr<ExprAST> ParseExpression() {
   auto LHS = ParseUnary();
   if (!LHS)
     return nullptr;
-  
+
   return ParseBinOpRHS(0, std::move(LHS));
 }
 
@@ -555,10 +554,10 @@ static std::unique_ptr<ExprAST> ParseExpression() {
 ///   ::= 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");
@@ -584,7 +583,7 @@ static std::unique_ptr<PrototypeAST> ParsePrototype() {
     FnName += (char)CurTok;
     Kind = 2;
     getNextToken();
-    
+
     // Read the precedence if present.
     if (CurTok == tok_number) {
       if (NumVal < 1 || NumVal > 100)
@@ -594,23 +593,23 @@ static std::unique_ptr<PrototypeAST> ParsePrototype() {
     }
     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);
 }
@@ -691,10 +690,10 @@ public:
   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;
 };
 
@@ -717,7 +716,7 @@ public:
       M(new Module(GenerateUniqueName("jit_module_"),
                    Session.getLLVMContext())),
       Builder(Session.getLLVMContext()) {
-    M->setDataLayout(*Session.getTarget().getDataLayout());
+    M->setDataLayout(Session.getTarget().createDataLayout());
   }
 
   SessionContext& getSession() { return Session; }
@@ -748,7 +747,7 @@ static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
                                           const std::string &VarName) {
   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
                  TheFunction->getEntryBlock().begin());
-  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), nullptr,
                            VarName.c_str());
 }
 
@@ -760,7 +759,7 @@ Value *VariableExprAST::IRGen(IRGenContext &C) const {
   // Look this variable up in the function.
   Value *V = C.NamedValues[Name];
 
-  if (V == 0)
+  if (!V)
     return ErrorP<Value>("Unknown variable name '" + Name + "'");
 
   // Load the value.
@@ -783,7 +782,7 @@ 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);
+    auto &LHSVar = static_cast<VariableExprAST &>(*LHS);
     // Codegen the RHS.
     Value *Val = RHS->IRGen(C);
     if (!Val) return nullptr;
@@ -795,11 +794,11 @@ Value *BinaryExprAST::IRGen(IRGenContext &C) const {
     }
     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");
@@ -812,7 +811,7 @@ Value *BinaryExprAST::IRGen(IRGenContext &C) const {
                                 "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);
@@ -820,7 +819,7 @@ Value *BinaryExprAST::IRGen(IRGenContext &C) const {
     Value *Ops[] = { L, R };
     return C.getBuilder().CreateCall(F, Ops, "binop");
   }
-   
+
   return ErrorP<Value>("Unknown binary operator");
 }
 
@@ -836,7 +835,7 @@ Value *CallExprAST::IRGen(IRGenContext &C) const {
       ArgsV.push_back(Args[i]->IRGen(C));
       if (!ArgsV.back()) return nullptr;
     }
-    
+
     return C.getBuilder().CreateCall(CalleeF, ArgsV, "calltmp");
   }
 
@@ -846,49 +845,49 @@ Value *CallExprAST::IRGen(IRGenContext &C) const {
 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 *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;
@@ -901,7 +900,7 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
   //   start = startexpr
   //   store start -> var
   //   goto loop
-  // loop: 
+  // loop:
   //   ...
   //   bodyexpr
   //   ...
@@ -914,40 +913,40 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
   //   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) {
@@ -957,52 +956,51 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
     // 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;
-  
+  if (!EndCond) return nullptr;
+
   // 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, 
+  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:
@@ -1014,22 +1012,22 @@ Value *VarExprAST::IRGen(IRGenContext &C) const {
       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];
@@ -1042,7 +1040,7 @@ 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(), 
+  std::vector<Type*> Doubles(Args.size(),
                              Type::getDoubleTy(getGlobalContext()));
   FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
                                        Doubles, false);
@@ -1055,26 +1053,26 @@ Function *PrototypeAST::IRGen(IRGenContext &C) const {
     // 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;
 }
 
@@ -1087,7 +1085,7 @@ void PrototypeAST::CreateArgumentAllocas(Function *F, IRGenContext &C) {
     AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
 
     // Store the initial value into the alloca.
-    C.getBuilder().CreateStore(AI, Alloca);
+    C.getBuilder().CreateStore(&*AI, Alloca);
 
     // Add arguments to variable symbol table.
     C.NamedValues[Args[Idx]] = Alloca;
@@ -1096,19 +1094,19 @@ void PrototypeAST::CreateArgumentAllocas(Function *F, IRGenContext &C) {
 
 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);
 
@@ -1121,7 +1119,7 @@ Function *FunctionAST::IRGen(IRGenContext &C) const {
 
     return TheFunction;
   }
-  
+
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
 
@@ -1170,16 +1168,14 @@ public:
     : Session(Session),
       CompileLayer(ObjectLayer, SimpleCompiler(Session.getTarget())),
       LazyEmitLayer(CompileLayer),
-      CompileCallbacks(LazyEmitLayer, CCMgrMemMgr, Session.getLLVMContext(),
-                       reinterpret_cast<uintptr_t>(EarthShatteringKaboom),
-                       64) {}
+      CompileCallbacks(reinterpret_cast<uintptr_t>(EarthShatteringKaboom)) {}
 
   std::string mangle(const std::string &Name) {
     std::string MangledName;
     {
       raw_string_ostream MangledNameStream(MangledName);
       Mangler::getNameWithPrefix(MangledNameStream, Name,
-                                 *Session.getTarget().getDataLayout());
+                                 Session.getTarget().createDataLayout());
     }
     return MangledName;
   }
@@ -1236,7 +1232,7 @@ private:
   RuntimeDyld::SymbolInfo searchFunctionASTs(const std::string &Name) {
     auto DefI = FunctionDefs.find(Name);
     if (DefI == FunctionDefs.end())
-      return 0;
+      return nullptr;
 
     // Return the address of the stub.
     // Take the FunctionAST out of the map.
@@ -1262,8 +1258,7 @@ private:
     //         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->getContext());
+    auto CallbackInfo = CompileCallbacks.getCompileCallback();
 
     // Step 3) Create a stub that will indirectly call the body of this
     //         function once it is compiled. Initially, set the function
@@ -1313,7 +1308,7 @@ private:
 
   std::map<std::string, std::unique_ptr<FunctionAST>> FunctionDefs;
 
-  JITCompileCallbackManager<LazyEmitLayerT, OrcX86_64> CompileCallbacks;
+  LocalJITCompileCallbackManager<OrcX86_64> CompileCallbacks;
 };
 
 static void HandleDefinition(SessionContext &S, KaleidoscopeJIT &J) {
@@ -1350,7 +1345,7 @@ static void HandleTopLevelExpression(SessionContext &S, KaleidoscopeJIT &J) {
 
       // 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();
@@ -1393,20 +1388,20 @@ 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;
@@ -1443,4 +1438,3 @@ int main() {
 
   return 0;
 }
-
diff --git a/examples/Kaleidoscope/Orc/initial/toy.cpp b/examples/Kaleidoscope/Orc/initial/toy.cpp
index 7e99c0f5ba54..2a6bb92246d0 100644
--- a/examples/Kaleidoscope/Orc/initial/toy.cpp
+++ b/examples/Kaleidoscope/Orc/initial/toy.cpp
@@ -38,14 +38,14 @@ 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
 };
@@ -86,7 +86,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -94,11 +94,11 @@ 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;
@@ -139,7 +139,7 @@ struct VariableExprAST : public ExprAST {
 
 /// UnaryExprAST - Expression class for a unary operator.
 struct UnaryExprAST : public ExprAST {
-  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand) 
+  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand)
     : Opcode(std::move(Opcode)), Operand(std::move(Operand)) {}
 
   Value *IRGen(IRGenContext &C) const override;
@@ -151,7 +151,7 @@ struct UnaryExprAST : public ExprAST {
 /// BinaryExprAST - Expression class for a binary operator.
 struct BinaryExprAST : public ExprAST {
   BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
-                std::unique_ptr<ExprAST> RHS) 
+                std::unique_ptr<ExprAST> RHS)
     : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
 
   Value *IRGen(IRGenContext &C) const override;
@@ -223,7 +223,7 @@ struct PrototypeAST {
 
   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];
@@ -267,7 +267,7 @@ 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 std::unique_ptr<ExprAST> ParseExpression();
 ///   ::= 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;
@@ -318,7 +318,7 @@ static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
 
   // Eat the ')'.
   getNextToken();
-  
+
   return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
 }
 
@@ -335,7 +335,7 @@ static std::unique_ptr<ExprAST> ParseParenExpr() {
   auto V = ParseExpression();
   if (!V)
     return nullptr;
-  
+
   if (CurTok != ')')
     return ErrorU<ExprAST>("expected ')'");
   getNextToken();  // eat ).
@@ -345,29 +345,29 @@ static std::unique_ptr<ExprAST> ParseParenExpr() {
 /// 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));
 }
@@ -378,26 +378,25 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
 
   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 == ',') {
@@ -406,11 +405,11 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
     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;
@@ -419,7 +418,7 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
                                        std::move(Step), std::move(Body));
 }
 
-/// varexpr ::= 'var' identifier ('=' expression)? 
+/// varexpr ::= 'var' identifier ('=' expression)?
 //                    (',' identifier ('=' expression)?)* 'in' expression
 static std::unique_ptr<VarExprAST> ParseVarExpr() {
   getNextToken();  // eat the var.
@@ -429,7 +428,7 @@ static std::unique_ptr<VarExprAST> ParseVarExpr() {
   // 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.
@@ -438,31 +437,31 @@ static std::unique_ptr<VarExprAST> ParseVarExpr() {
     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));
 }
 
@@ -492,7 +491,7 @@ 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();
@@ -508,21 +507,21 @@ static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
   // 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();
@@ -531,7 +530,7 @@ static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
       if (!RHS)
         return nullptr;
     }
-    
+
     // Merge LHS/RHS.
     LHS = llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
   }
@@ -544,7 +543,7 @@ static std::unique_ptr<ExprAST> ParseExpression() {
   auto LHS = ParseUnary();
   if (!LHS)
     return nullptr;
-  
+
   return ParseBinOpRHS(0, std::move(LHS));
 }
 
@@ -554,10 +553,10 @@ static std::unique_ptr<ExprAST> ParseExpression() {
 ///   ::= 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");
@@ -583,7 +582,7 @@ static std::unique_ptr<PrototypeAST> ParsePrototype() {
     FnName += (char)CurTok;
     Kind = 2;
     getNextToken();
-    
+
     // Read the precedence if present.
     if (CurTok == tok_number) {
       if (NumVal < 1 || NumVal > 100)
@@ -593,23 +592,23 @@ static std::unique_ptr<PrototypeAST> ParsePrototype() {
     }
     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);
 }
@@ -690,10 +689,10 @@ public:
   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;
 };
 
@@ -716,7 +715,7 @@ public:
       M(new Module(GenerateUniqueName("jit_module_"),
                    Session.getLLVMContext())),
       Builder(Session.getLLVMContext()) {
-    M->setDataLayout(*Session.getTarget().getDataLayout());
+    M->setDataLayout(Session.getTarget().createDataLayout());
   }
 
   SessionContext& getSession() { return Session; }
@@ -747,7 +746,7 @@ static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
                                           const std::string &VarName) {
   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
                  TheFunction->getEntryBlock().begin());
-  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), nullptr,
                            VarName.c_str());
 }
 
@@ -759,7 +758,7 @@ Value *VariableExprAST::IRGen(IRGenContext &C) const {
   // Look this variable up in the function.
   Value *V = C.NamedValues[Name];
 
-  if (V == 0)
+  if (!V)
     return ErrorP<Value>("Unknown variable name '" + Name + "'");
 
   // Load the value.
@@ -782,7 +781,7 @@ 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);
+    auto &LHSVar = static_cast<VariableExprAST &>(*LHS);
     // Codegen the RHS.
     Value *Val = RHS->IRGen(C);
     if (!Val) return nullptr;
@@ -794,11 +793,11 @@ Value *BinaryExprAST::IRGen(IRGenContext &C) const {
     }
     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");
@@ -811,7 +810,7 @@ Value *BinaryExprAST::IRGen(IRGenContext &C) const {
                                 "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);
@@ -819,7 +818,7 @@ Value *BinaryExprAST::IRGen(IRGenContext &C) const {
     Value *Ops[] = { L, R };
     return C.getBuilder().CreateCall(F, Ops, "binop");
   }
-   
+
   return ErrorP<Value>("Unknown binary operator");
 }
 
@@ -835,7 +834,7 @@ Value *CallExprAST::IRGen(IRGenContext &C) const {
       ArgsV.push_back(Args[i]->IRGen(C));
       if (!ArgsV.back()) return nullptr;
     }
-    
+
     return C.getBuilder().CreateCall(CalleeF, ArgsV, "calltmp");
   }
 
@@ -845,49 +844,49 @@ Value *CallExprAST::IRGen(IRGenContext &C) const {
 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 *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;
@@ -900,7 +899,7 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
   //   start = startexpr
   //   store start -> var
   //   goto loop
-  // loop: 
+  // loop:
   //   ...
   //   bodyexpr
   //   ...
@@ -913,40 +912,40 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
   //   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) {
@@ -956,52 +955,51 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
     // 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;
-  
+  if (!EndCond) return nullptr;
+
   // 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, 
+  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:
@@ -1013,22 +1011,22 @@ Value *VarExprAST::IRGen(IRGenContext &C) const {
       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];
@@ -1041,7 +1039,7 @@ 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(), 
+  std::vector<Type*> Doubles(Args.size(),
                              Type::getDoubleTy(getGlobalContext()));
   FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
                                        Doubles, false);
@@ -1054,26 +1052,26 @@ Function *PrototypeAST::IRGen(IRGenContext &C) const {
     // 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;
 }
 
@@ -1086,7 +1084,7 @@ void PrototypeAST::CreateArgumentAllocas(Function *F, IRGenContext &C) {
     AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
 
     // Store the initial value into the alloca.
-    C.getBuilder().CreateStore(AI, Alloca);
+    C.getBuilder().CreateStore(&*AI, Alloca);
 
     // Add arguments to variable symbol table.
     C.NamedValues[Args[Idx]] = Alloca;
@@ -1095,19 +1093,19 @@ void PrototypeAST::CreateArgumentAllocas(Function *F, IRGenContext &C) {
 
 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);
 
@@ -1120,7 +1118,7 @@ Function *FunctionAST::IRGen(IRGenContext &C) const {
 
     return TheFunction;
   }
-  
+
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
 
@@ -1160,7 +1158,7 @@ public:
   typedef CompileLayerT::ModuleSetHandleT ModuleHandleT;
 
   KaleidoscopeJIT(SessionContext &Session)
-      : DL(*Session.getTarget().getDataLayout()),
+      : DL(Session.getTarget().createDataLayout()),
         CompileLayer(ObjectLayer, SimpleCompiler(Session.getTarget())) {}
 
   std::string mangle(const std::string &Name) {
@@ -1201,7 +1199,7 @@ public:
   }
 
 private:
-  const DataLayout &DL;
+  const DataLayout DL;
   ObjLayerT ObjectLayer;
   CompileLayerT CompileLayer;
 };
@@ -1242,7 +1240,7 @@ static void HandleTopLevelExpression(SessionContext &S, KaleidoscopeJIT &J) {
 
       // 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();
@@ -1285,20 +1283,20 @@ 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;
@@ -1335,4 +1333,3 @@ int main() {
 
   return 0;
 }
-
diff --git a/examples/Kaleidoscope/Orc/lazy_codegen/toy.cpp b/examples/Kaleidoscope/Orc/lazy_codegen/toy.cpp
index 4b4c191171b4..5205b406ed71 100644
--- a/examples/Kaleidoscope/Orc/lazy_codegen/toy.cpp
+++ b/examples/Kaleidoscope/Orc/lazy_codegen/toy.cpp
@@ -38,14 +38,14 @@ 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
 };
@@ -86,7 +86,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -94,11 +94,11 @@ 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;
@@ -139,7 +139,7 @@ struct VariableExprAST : public ExprAST {
 
 /// UnaryExprAST - Expression class for a unary operator.
 struct UnaryExprAST : public ExprAST {
-  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand) 
+  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand)
     : Opcode(std::move(Opcode)), Operand(std::move(Operand)) {}
 
   Value *IRGen(IRGenContext &C) const override;
@@ -151,7 +151,7 @@ struct UnaryExprAST : public ExprAST {
 /// BinaryExprAST - Expression class for a binary operator.
 struct BinaryExprAST : public ExprAST {
   BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
-                std::unique_ptr<ExprAST> RHS) 
+                std::unique_ptr<ExprAST> RHS)
     : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
 
   Value *IRGen(IRGenContext &C) const override;
@@ -223,7 +223,7 @@ struct PrototypeAST {
 
   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];
@@ -267,7 +267,7 @@ 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 std::unique_ptr<ExprAST> ParseExpression();
 ///   ::= 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;
@@ -318,7 +318,7 @@ static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
 
   // Eat the ')'.
   getNextToken();
-  
+
   return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
 }
 
@@ -335,7 +335,7 @@ static std::unique_ptr<ExprAST> ParseParenExpr() {
   auto V = ParseExpression();
   if (!V)
     return nullptr;
-  
+
   if (CurTok != ')')
     return ErrorU<ExprAST>("expected ')'");
   getNextToken();  // eat ).
@@ -345,29 +345,29 @@ static std::unique_ptr<ExprAST> ParseParenExpr() {
 /// 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));
 }
@@ -378,26 +378,25 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
 
   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 == ',') {
@@ -406,11 +405,11 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
     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;
@@ -419,7 +418,7 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
                                        std::move(Step), std::move(Body));
 }
 
-/// varexpr ::= 'var' identifier ('=' expression)? 
+/// varexpr ::= 'var' identifier ('=' expression)?
 //                    (',' identifier ('=' expression)?)* 'in' expression
 static std::unique_ptr<VarExprAST> ParseVarExpr() {
   getNextToken();  // eat the var.
@@ -429,7 +428,7 @@ static std::unique_ptr<VarExprAST> ParseVarExpr() {
   // 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.
@@ -438,31 +437,31 @@ static std::unique_ptr<VarExprAST> ParseVarExpr() {
     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));
 }
 
@@ -492,7 +491,7 @@ 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();
@@ -508,21 +507,21 @@ static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
   // 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();
@@ -531,7 +530,7 @@ static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
       if (!RHS)
         return nullptr;
     }
-    
+
     // Merge LHS/RHS.
     LHS = llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
   }
@@ -544,7 +543,7 @@ static std::unique_ptr<ExprAST> ParseExpression() {
   auto LHS = ParseUnary();
   if (!LHS)
     return nullptr;
-  
+
   return ParseBinOpRHS(0, std::move(LHS));
 }
 
@@ -554,10 +553,10 @@ static std::unique_ptr<ExprAST> ParseExpression() {
 ///   ::= 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");
@@ -583,7 +582,7 @@ static std::unique_ptr<PrototypeAST> ParsePrototype() {
     FnName += (char)CurTok;
     Kind = 2;
     getNextToken();
-    
+
     // Read the precedence if present.
     if (CurTok == tok_number) {
       if (NumVal < 1 || NumVal > 100)
@@ -593,23 +592,23 @@ static std::unique_ptr<PrototypeAST> ParsePrototype() {
     }
     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);
 }
@@ -690,10 +689,10 @@ public:
   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;
 };
 
@@ -716,7 +715,7 @@ public:
       M(new Module(GenerateUniqueName("jit_module_"),
                    Session.getLLVMContext())),
       Builder(Session.getLLVMContext()) {
-    M->setDataLayout(*Session.getTarget().getDataLayout());
+    M->setDataLayout(Session.getTarget().createDataLayout());
   }
 
   SessionContext& getSession() { return Session; }
@@ -747,7 +746,7 @@ static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
                                           const std::string &VarName) {
   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
                  TheFunction->getEntryBlock().begin());
-  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), nullptr,
                            VarName.c_str());
 }
 
@@ -759,7 +758,7 @@ Value *VariableExprAST::IRGen(IRGenContext &C) const {
   // Look this variable up in the function.
   Value *V = C.NamedValues[Name];
 
-  if (V == 0)
+  if (!V)
     return ErrorP<Value>("Unknown variable name '" + Name + "'");
 
   // Load the value.
@@ -782,7 +781,7 @@ 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);
+    auto &LHSVar = static_cast<VariableExprAST &>(*LHS);
     // Codegen the RHS.
     Value *Val = RHS->IRGen(C);
     if (!Val) return nullptr;
@@ -794,11 +793,11 @@ Value *BinaryExprAST::IRGen(IRGenContext &C) const {
     }
     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");
@@ -811,7 +810,7 @@ Value *BinaryExprAST::IRGen(IRGenContext &C) const {
                                 "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);
@@ -819,7 +818,7 @@ Value *BinaryExprAST::IRGen(IRGenContext &C) const {
     Value *Ops[] = { L, R };
     return C.getBuilder().CreateCall(F, Ops, "binop");
   }
-   
+
   return ErrorP<Value>("Unknown binary operator");
 }
 
@@ -835,7 +834,7 @@ Value *CallExprAST::IRGen(IRGenContext &C) const {
       ArgsV.push_back(Args[i]->IRGen(C));
       if (!ArgsV.back()) return nullptr;
     }
-    
+
     return C.getBuilder().CreateCall(CalleeF, ArgsV, "calltmp");
   }
 
@@ -845,49 +844,49 @@ Value *CallExprAST::IRGen(IRGenContext &C) const {
 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 *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;
@@ -900,7 +899,7 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
   //   start = startexpr
   //   store start -> var
   //   goto loop
-  // loop: 
+  // loop:
   //   ...
   //   bodyexpr
   //   ...
@@ -913,40 +912,40 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
   //   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) {
@@ -956,52 +955,51 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
     // 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;
-  
+  if (!EndCond) return nullptr;
+
   // 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, 
+  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:
@@ -1013,22 +1011,22 @@ Value *VarExprAST::IRGen(IRGenContext &C) const {
       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];
@@ -1041,7 +1039,7 @@ 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(), 
+  std::vector<Type*> Doubles(Args.size(),
                              Type::getDoubleTy(getGlobalContext()));
   FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
                                        Doubles, false);
@@ -1054,26 +1052,26 @@ Function *PrototypeAST::IRGen(IRGenContext &C) const {
     // 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;
 }
 
@@ -1086,7 +1084,7 @@ void PrototypeAST::CreateArgumentAllocas(Function *F, IRGenContext &C) {
     AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
 
     // Store the initial value into the alloca.
-    C.getBuilder().CreateStore(AI, Alloca);
+    C.getBuilder().CreateStore(&*AI, Alloca);
 
     // Add arguments to variable symbol table.
     C.NamedValues[Args[Idx]] = Alloca;
@@ -1095,19 +1093,19 @@ void PrototypeAST::CreateArgumentAllocas(Function *F, IRGenContext &C) {
 
 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);
 
@@ -1120,7 +1118,7 @@ Function *FunctionAST::IRGen(IRGenContext &C) const {
 
     return TheFunction;
   }
-  
+
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
 
@@ -1162,7 +1160,7 @@ public:
   typedef LazyEmitLayerT::ModuleSetHandleT ModuleHandleT;
 
   KaleidoscopeJIT(SessionContext &Session)
-      : DL(*Session.getTarget().getDataLayout()),
+      : DL(Session.getTarget().createDataLayout()),
         CompileLayer(ObjectLayer, SimpleCompiler(Session.getTarget())),
         LazyEmitLayer(CompileLayer) {}
 
@@ -1204,7 +1202,7 @@ public:
   }
 
 private:
-  const DataLayout &DL;
+  const DataLayout DL;
   ObjLayerT ObjectLayer;
   CompileLayerT CompileLayer;
   LazyEmitLayerT LazyEmitLayer;
@@ -1246,7 +1244,7 @@ static void HandleTopLevelExpression(SessionContext &S, KaleidoscopeJIT &J) {
 
       // 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();
@@ -1289,20 +1287,20 @@ 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;
@@ -1339,4 +1337,3 @@ int main() {
 
   return 0;
 }
-
diff --git a/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp b/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp
index ca34de7e2244..ebaff49e89b2 100644
--- a/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp
+++ b/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp
@@ -38,14 +38,14 @@ 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
 };
@@ -86,7 +86,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -94,11 +94,11 @@ 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;
@@ -139,7 +139,7 @@ struct VariableExprAST : public ExprAST {
 
 /// UnaryExprAST - Expression class for a unary operator.
 struct UnaryExprAST : public ExprAST {
-  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand) 
+  UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand)
     : Opcode(std::move(Opcode)), Operand(std::move(Operand)) {}
 
   Value *IRGen(IRGenContext &C) const override;
@@ -151,7 +151,7 @@ struct UnaryExprAST : public ExprAST {
 /// BinaryExprAST - Expression class for a binary operator.
 struct BinaryExprAST : public ExprAST {
   BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
-                std::unique_ptr<ExprAST> RHS) 
+                std::unique_ptr<ExprAST> RHS)
     : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
 
   Value *IRGen(IRGenContext &C) const override;
@@ -223,7 +223,7 @@ struct PrototypeAST {
 
   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];
@@ -267,7 +267,7 @@ 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 std::unique_ptr<ExprAST> ParseExpression();
 ///   ::= 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;
@@ -318,7 +318,7 @@ static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
 
   // Eat the ')'.
   getNextToken();
-  
+
   return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
 }
 
@@ -335,7 +335,7 @@ static std::unique_ptr<ExprAST> ParseParenExpr() {
   auto V = ParseExpression();
   if (!V)
     return nullptr;
-  
+
   if (CurTok != ')')
     return ErrorU<ExprAST>("expected ')'");
   getNextToken();  // eat ).
@@ -345,29 +345,29 @@ static std::unique_ptr<ExprAST> ParseParenExpr() {
 /// 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));
 }
@@ -378,26 +378,25 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
 
   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 == ',') {
@@ -406,11 +405,11 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
     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;
@@ -419,7 +418,7 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
                                        std::move(Step), std::move(Body));
 }
 
-/// varexpr ::= 'var' identifier ('=' expression)? 
+/// varexpr ::= 'var' identifier ('=' expression)?
 //                    (',' identifier ('=' expression)?)* 'in' expression
 static std::unique_ptr<VarExprAST> ParseVarExpr() {
   getNextToken();  // eat the var.
@@ -429,7 +428,7 @@ static std::unique_ptr<VarExprAST> ParseVarExpr() {
   // 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.
@@ -438,31 +437,31 @@ static std::unique_ptr<VarExprAST> ParseVarExpr() {
     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));
 }
 
@@ -492,7 +491,7 @@ 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();
@@ -508,21 +507,21 @@ static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
   // 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();
@@ -531,7 +530,7 @@ static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
       if (!RHS)
         return nullptr;
     }
-    
+
     // Merge LHS/RHS.
     LHS = llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
   }
@@ -544,7 +543,7 @@ static std::unique_ptr<ExprAST> ParseExpression() {
   auto LHS = ParseUnary();
   if (!LHS)
     return nullptr;
-  
+
   return ParseBinOpRHS(0, std::move(LHS));
 }
 
@@ -554,10 +553,10 @@ static std::unique_ptr<ExprAST> ParseExpression() {
 ///   ::= 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");
@@ -583,7 +582,7 @@ static std::unique_ptr<PrototypeAST> ParsePrototype() {
     FnName += (char)CurTok;
     Kind = 2;
     getNextToken();
-    
+
     // Read the precedence if present.
     if (CurTok == tok_number) {
       if (NumVal < 1 || NumVal > 100)
@@ -593,23 +592,23 @@ static std::unique_ptr<PrototypeAST> ParsePrototype() {
     }
     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);
 }
@@ -690,10 +689,10 @@ public:
   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;
 };
 
@@ -716,7 +715,7 @@ public:
       M(new Module(GenerateUniqueName("jit_module_"),
                    Session.getLLVMContext())),
       Builder(Session.getLLVMContext()) {
-    M->setDataLayout(*Session.getTarget().getDataLayout());
+    M->setDataLayout(Session.getTarget().createDataLayout());
   }
 
   SessionContext& getSession() { return Session; }
@@ -747,7 +746,7 @@ static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
                                           const std::string &VarName) {
   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
                  TheFunction->getEntryBlock().begin());
-  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), nullptr,
                            VarName.c_str());
 }
 
@@ -759,7 +758,7 @@ Value *VariableExprAST::IRGen(IRGenContext &C) const {
   // Look this variable up in the function.
   Value *V = C.NamedValues[Name];
 
-  if (V == 0)
+  if (!V)
     return ErrorP<Value>("Unknown variable name '" + Name + "'");
 
   // Load the value.
@@ -782,7 +781,7 @@ 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);
+    auto &LHSVar = static_cast<VariableExprAST &>(*LHS);
     // Codegen the RHS.
     Value *Val = RHS->IRGen(C);
     if (!Val) return nullptr;
@@ -794,11 +793,11 @@ Value *BinaryExprAST::IRGen(IRGenContext &C) const {
     }
     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");
@@ -811,7 +810,7 @@ Value *BinaryExprAST::IRGen(IRGenContext &C) const {
                                 "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);
@@ -819,7 +818,7 @@ Value *BinaryExprAST::IRGen(IRGenContext &C) const {
     Value *Ops[] = { L, R };
     return C.getBuilder().CreateCall(F, Ops, "binop");
   }
-   
+
   return ErrorP<Value>("Unknown binary operator");
 }
 
@@ -835,7 +834,7 @@ Value *CallExprAST::IRGen(IRGenContext &C) const {
       ArgsV.push_back(Args[i]->IRGen(C));
       if (!ArgsV.back()) return nullptr;
     }
-    
+
     return C.getBuilder().CreateCall(CalleeF, ArgsV, "calltmp");
   }
 
@@ -845,49 +844,49 @@ Value *CallExprAST::IRGen(IRGenContext &C) const {
 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 *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;
@@ -900,7 +899,7 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
   //   start = startexpr
   //   store start -> var
   //   goto loop
-  // loop: 
+  // loop:
   //   ...
   //   bodyexpr
   //   ...
@@ -913,40 +912,40 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
   //   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) {
@@ -956,52 +955,51 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
     // 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;
-  
+  if (!EndCond) return nullptr;
+
   // 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, 
+  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:
@@ -1013,22 +1011,22 @@ Value *VarExprAST::IRGen(IRGenContext &C) const {
       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];
@@ -1041,7 +1039,7 @@ 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(), 
+  std::vector<Type*> Doubles(Args.size(),
                              Type::getDoubleTy(getGlobalContext()));
   FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
                                        Doubles, false);
@@ -1054,26 +1052,26 @@ Function *PrototypeAST::IRGen(IRGenContext &C) const {
     // 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;
 }
 
@@ -1086,7 +1084,7 @@ void PrototypeAST::CreateArgumentAllocas(Function *F, IRGenContext &C) {
     AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
 
     // Store the initial value into the alloca.
-    C.getBuilder().CreateStore(AI, Alloca);
+    C.getBuilder().CreateStore(&*AI, Alloca);
 
     // Add arguments to variable symbol table.
     C.NamedValues[Args[Idx]] = Alloca;
@@ -1095,19 +1093,19 @@ void PrototypeAST::CreateArgumentAllocas(Function *F, IRGenContext &C) {
 
 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);
 
@@ -1120,7 +1118,7 @@ Function *FunctionAST::IRGen(IRGenContext &C) const {
 
     return TheFunction;
   }
-  
+
   // Error reading body, remove function.
   TheFunction->eraseFromParent();
 
@@ -1170,7 +1168,7 @@ public:
     {
       raw_string_ostream MangledNameStream(MangledName);
       Mangler::getNameWithPrefix(MangledNameStream, Name,
-                                 *Session.getTarget().getDataLayout());
+                                 Session.getTarget().createDataLayout());
     }
     return MangledName;
   }
@@ -1223,7 +1221,7 @@ private:
   RuntimeDyld::SymbolInfo searchFunctionASTs(const std::string &Name) {
     auto DefI = FunctionDefs.find(Name);
     if (DefI == FunctionDefs.end())
-      return 0;
+      return nullptr;
 
     // Take the FunctionAST out of the map.
     auto FnAST = std::move(DefI->second);
@@ -1277,7 +1275,7 @@ static void HandleTopLevelExpression(SessionContext &S, KaleidoscopeJIT &J) {
 
       // 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();
@@ -1320,20 +1318,20 @@ 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;
@@ -1370,4 +1368,3 @@ int main() {
 
   return 0;
 }
-
diff --git a/examples/Kaleidoscope/include/KaleidoscopeJIT.h b/examples/Kaleidoscope/include/KaleidoscopeJIT.h
new file mode 100644
index 000000000000..0c825cc94c0e
--- /dev/null
+++ b/examples/Kaleidoscope/include/KaleidoscopeJIT.h
@@ -0,0 +1,114 @@
+//===----- KaleidoscopeJIT.h - A simple JIT for Kaleidoscope ----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Contains a simple JIT definition for use in the kaleidoscope tutorials.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H
+#define LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H
+
+#include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
+#include "llvm/ExecutionEngine/Orc/CompileUtils.h"
+#include "llvm/ExecutionEngine/Orc/IRCompileLayer.h"
+#include "llvm/ExecutionEngine/Orc/LambdaResolver.h"
+#include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
+#include "llvm/IR/Mangler.h"
+#include "llvm/Support/DynamicLibrary.h"
+
+namespace llvm {
+namespace orc {
+
+class KaleidoscopeJIT {
+public:
+  typedef ObjectLinkingLayer<> ObjLayerT;
+  typedef IRCompileLayer<ObjLayerT> CompileLayerT;
+  typedef CompileLayerT::ModuleSetHandleT ModuleHandleT;
+
+  KaleidoscopeJIT()
+      : TM(EngineBuilder().selectTarget()), DL(TM->createDataLayout()),
+        CompileLayer(ObjectLayer, SimpleCompiler(*TM)) {
+    llvm::sys::DynamicLibrary::LoadLibraryPermanently(nullptr);
+  }
+
+  TargetMachine &getTargetMachine() { return *TM; }
+
+  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 Resolver = createLambdaResolver(
+        [&](const std::string &Name) {
+          if (auto Sym = findMangledSymbol(Name))
+            return RuntimeDyld::SymbolInfo(Sym.getAddress(), Sym.getFlags());
+          return RuntimeDyld::SymbolInfo(nullptr);
+        },
+        [](const std::string &S) { return nullptr; });
+    auto H = CompileLayer.addModuleSet(singletonSet(std::move(M)),
+                                       make_unique<SectionMemoryManager>(),
+                                       std::move(Resolver));
+
+    ModuleHandles.push_back(H);
+    return H;
+  }
+
+  void removeModule(ModuleHandleT H) {
+    ModuleHandles.erase(
+        std::find(ModuleHandles.begin(), ModuleHandles.end(), H));
+    CompileLayer.removeModuleSet(H);
+  }
+
+  JITSymbol findSymbol(const std::string Name) {
+    return findMangledSymbol(mangle(Name));
+  }
+
+private:
+
+  std::string mangle(const std::string &Name) {
+    std::string MangledName;
+    {
+      raw_string_ostream MangledNameStream(MangledName);
+      Mangler::getNameWithPrefix(MangledNameStream, Name, DL);
+    }
+    return MangledName;
+  }
+
+  template <typename T> static std::vector<T> singletonSet(T t) {
+    std::vector<T> Vec;
+    Vec.push_back(std::move(t));
+    return Vec;
+  }
+
+  JITSymbol findMangledSymbol(const std::string &Name) {
+    // Search modules in reverse order: from last added to first added.
+    // This is the opposite of the usual search order for dlsym, but makes more
+    // sense in a REPL where we want to bind to the newest available definition.
+    for (auto H : make_range(ModuleHandles.rbegin(), ModuleHandles.rend()))
+      if (auto Sym = CompileLayer.findSymbolIn(H, Name, true))
+        return Sym;
+
+    // If we can't find the symbol in the JIT, try looking in the host process.
+    if (auto SymAddr = RTDyldMemoryManager::getSymbolAddressInProcess(Name))
+      return JITSymbol(SymAddr, JITSymbolFlags::Exported);
+
+    return nullptr;
+  }
+
+  std::unique_ptr<TargetMachine> TM;
+  const DataLayout DL;
+  ObjLayerT ObjectLayer;
+  CompileLayerT CompileLayer;
+  std::vector<ModuleHandleT> ModuleHandles;
+};
+
+} // End namespace orc.
+} // End namespace llvm
+
+#endif // LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H
diff --git a/examples/ParallelJIT/ParallelJIT.cpp b/examples/ParallelJIT/ParallelJIT.cpp
index b2c53a9bb10e..3c485d4c964d 100644
--- a/examples/ParallelJIT/ParallelJIT.cpp
+++ b/examples/ParallelJIT/ParallelJIT.cpp
@@ -28,6 +28,7 @@
 #include "llvm/Support/TargetSelect.h"
 #include <iostream>
 #include <pthread.h>
+
 using namespace llvm;
 
 static Function* createAdd1(Module *M) {
@@ -38,7 +39,7 @@ static Function* createAdd1(Module *M) {
     cast<Function>(M->getOrInsertFunction("add1",
                                           Type::getInt32Ty(M->getContext()),
                                           Type::getInt32Ty(M->getContext()),
-                                          (Type *)0));
+                                          nullptr));
 
   // Add a basic block to the function. As before, it automatically inserts
   // because of the last argument.
@@ -49,7 +50,7 @@ static Function* createAdd1(Module *M) {
 
   // Get pointers to the integer argument of the add1 function...
   assert(Add1F->arg_begin() != Add1F->arg_end()); // Make sure there's an arg
-  Argument *ArgX = Add1F->arg_begin();  // Get the arg
+  Argument *ArgX = &*Add1F->arg_begin();          // Get the arg
   ArgX->setName("AnArg");            // Give it a nice symbolic name for fun.
 
   // Create the add instruction, inserting it into the end of BB.
@@ -69,7 +70,7 @@ static Function *CreateFibFunction(Module *M) {
     cast<Function>(M->getOrInsertFunction("fib",
                                           Type::getInt32Ty(M->getContext()),
                                           Type::getInt32Ty(M->getContext()),
-                                          (Type *)0));
+                                          nullptr));
 
   // Add a basic block to the function.
   BasicBlock *BB = BasicBlock::Create(M->getContext(), "EntryBlock", FibF);
@@ -79,7 +80,7 @@ static Function *CreateFibFunction(Module *M) {
   Value *Two = ConstantInt::get(Type::getInt32Ty(M->getContext()), 2);
 
   // Get pointer to the integer argument of the add1 function...
-  Argument *ArgX = FibF->arg_begin();   // Get the arg.
+  Argument *ArgX = &*FibF->arg_begin(); // Get the arg.
   ArgX->setName("AnArg");            // Give it a nice symbolic name for fun.
 
   // Create the true_block.
@@ -129,10 +130,10 @@ public:
     n = 0;
     waitFor = 0;
 
-    int result = pthread_cond_init( &condition, NULL );
+    int result = pthread_cond_init( &condition, nullptr );
     assert( result == 0 );
 
-    result = pthread_mutex_init( &mutex, NULL );
+    result = pthread_mutex_init( &mutex, nullptr );
     assert( result == 0 );
   }
 
@@ -261,21 +262,21 @@ int main() {
   struct threadParams fib2 = { EE, fibF, 42 };
 
   pthread_t add1Thread;
-  int result = pthread_create( &add1Thread, NULL, callFunc, &add1 );
+  int result = pthread_create( &add1Thread, nullptr, callFunc, &add1 );
   if ( result != 0 ) {
           std::cerr << "Could not create thread" << std::endl;
           return 1;
   }
 
   pthread_t fibThread1;
-  result = pthread_create( &fibThread1, NULL, callFunc, &fib1 );
+  result = pthread_create( &fibThread1, nullptr, callFunc, &fib1 );
   if ( result != 0 ) {
           std::cerr << "Could not create thread" << std::endl;
           return 1;
   }
 
   pthread_t fibThread2;
-  result = pthread_create( &fibThread2, NULL, callFunc, &fib2 );
+  result = pthread_create( &fibThread2, nullptr, callFunc, &fib2 );
   if ( result != 0 ) {
           std::cerr << "Could not create thread" << std::endl;
           return 1;