X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=examples%2FKaleidoscope%2FChapter5%2Ftoy.cpp;h=eeca4775eeb11698617b88fa8b2275dee9b1cdb7;hb=d16725c31fbb40fcbf0cdf68b2b417ba445c5140;hp=3f3f0a019c6ff180606e2b211726eb85e6a93030;hpb=57edc9d4ff1648568a5dd7e9958649065b260dca;p=oota-llvm.git

diff --git a/examples/Kaleidoscope/Chapter5/toy.cpp b/examples/Kaleidoscope/Chapter5/toy.cpp
index 3f3f0a019c6..eeca4775eeb 100644
--- a/examples/Kaleidoscope/Chapter5/toy.cpp
+++ b/examples/Kaleidoscope/Chapter5/toy.cpp
@@ -1,13 +1,10 @@
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/Analysis/Passes.h"
-#include "llvm/ExecutionEngine/ExecutionEngine.h"
-#include "llvm/ExecutionEngine/JIT.h"
-#include "llvm/IR/DataLayout.h"
-#include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
-#include "llvm/PassManager.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Transforms/Scalar.h"
 #include <cctype>
@@ -15,7 +12,10 @@
 #include <map>
 #include <string>
 #include <vector>
+#include "../include/KaleidoscopeJIT.h"
+
 using namespace llvm;
+using namespace llvm::orc;
 
 //===----------------------------------------------------------------------===//
 // Lexer
@@ -27,18 +27,23 @@ enum Token {
   tok_eof = -1,
 
   // commands
-  tok_def = -2, tok_extern = -3,
+  tok_def = -2,
+  tok_extern = -3,
 
   // primary
-  tok_identifier = -4, tok_number = -5,
-  
+  tok_identifier = -4,
+  tok_number = -5,
+
   // control
-  tok_if = -6, tok_then = -7, tok_else = -8,
-  tok_for = -9, tok_in = -10
+  tok_if = -6,
+  tok_then = -7,
+  tok_else = -8,
+  tok_for = -9,
+  tok_in = -10
 };
 
-static std::string IdentifierStr;  // Filled in if tok_identifier
-static double NumVal;              // Filled in if tok_number
+static std::string IdentifierStr; // Filled in if tok_identifier
+static double NumVal;             // Filled in if tok_number
 
 /// gettok - Return the next token from standard input.
 static int gettok() {
@@ -53,36 +58,44 @@ static int gettok() {
     while (isalnum((LastChar = getchar())))
       IdentifierStr += LastChar;
 
-    if (IdentifierStr == "def") return tok_def;
-    if (IdentifierStr == "extern") return tok_extern;
-    if (IdentifierStr == "if") return tok_if;
-    if (IdentifierStr == "then") return tok_then;
-    if (IdentifierStr == "else") return tok_else;
-    if (IdentifierStr == "for") return tok_for;
-    if (IdentifierStr == "in") return tok_in;
+    if (IdentifierStr == "def")
+      return tok_def;
+    if (IdentifierStr == "extern")
+      return tok_extern;
+    if (IdentifierStr == "if")
+      return tok_if;
+    if (IdentifierStr == "then")
+      return tok_then;
+    if (IdentifierStr == "else")
+      return tok_else;
+    if (IdentifierStr == "for")
+      return tok_for;
+    if (IdentifierStr == "in")
+      return tok_in;
     return tok_identifier;
   }
 
-  if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
+  if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
     std::string NumStr;
     do {
       NumStr += LastChar;
       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;
@@ -101,63 +114,74 @@ 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) {}
-  virtual Value *Codegen();
+  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) {}
-  virtual Value *Codegen();
+  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) {}
-  virtual Value *Codegen();
+  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) {}
-  virtual Value *Codegen();
+  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) {}
-  virtual Value *Codegen();
+  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) {}
-  virtual Value *Codegen();
+  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,
@@ -166,22 +190,24 @@ 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
 
@@ -193,9 +219,7 @@ 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.
@@ -205,41 +229,70 @@ 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();
 
-static 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);
+}
+
+/// 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");
@@ -249,95 +302,84 @@ 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() {
-  getNextToken();  // eat the if.
-  
+static std::unique_ptr<ExprAST> ParseIfExpr() {
+  getNextToken(); // eat the if.
+
   // condition.
-  ExprAST *Cond = ParseExpression();
-  if (!Cond) return 0;
-  
+  auto Cond = ParseExpression();
+  if (!Cond)
+    return nullptr;
+
   if (CurTok != tok_then)
     return Error("expected then");
-  getNextToken();  // eat the then
-  
-  ExprAST *Then = ParseExpression();
-  if (Then == 0) return 0;
-  
+  getNextToken(); // eat the then
+
+  auto Then = ParseExpression();
+  if (!Then)
+    return nullptr;
+
   if (CurTok != tok_else)
     return Error("expected else");
-  
+
   getNextToken();
-  
-  ExprAST *Else = ParseExpression();
-  if (!Else) return 0;
-  
-  return new IfExprAST(Cond, Then, Else);
+
+  auto Else = ParseExpression();
+  if (!Else)
+    return nullptr;
+
+  return llvm::make_unique<IfExprAST>(std::move(Cond), std::move(Then),
+                                      std::move(Else));
 }
 
 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
-static ExprAST *ParseForExpr() {
-  getNextToken();  // eat the for.
+static std::unique_ptr<ExprAST> ParseForExpr() {
+  getNextToken(); // eat the for.
 
   if (CurTok != tok_identifier)
     return Error("expected identifier after for");
-  
+
   std::string IdName = IdentifierStr;
-  getNextToken();  // eat identifier.
-  
+  getNextToken(); // eat identifier.
+
   if (CurTok != '=')
     return Error("expected '=' after for");
-  getNextToken();  // eat '='.
-  
-  
-  ExprAST *Start = ParseExpression();
-  if (Start == 0) return 0;
+  getNextToken(); // eat '='.
+
+  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;
+  getNextToken(); // eat 'in'.
+
+  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
@@ -346,108 +388,121 @@ 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");
-  case tok_identifier: return ParseIdentifierExpr();
-  case tok_number:     return ParseNumberExpr();
-  case '(':            return ParseParenExpr();
-  case tok_if:         return ParseIfExpr();
-  case tok_for:        return ParseForExpr();
+  default:
+    return Error("unknown token when expecting an expression");
+  case tok_identifier:
+    return ParseIdentifierExpr();
+  case tok_number:
+    return ParseNumberExpr();
+  case '(':
+    return ParseParenExpr();
+  case tok_if:
+    return ParseIfExpr();
+  case tok_for:
+    return ParseForExpr();
   }
 }
 
 /// 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();
 }
 
@@ -455,286 +510,323 @@ 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 FunctionPassManager *TheFPM;
+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 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();
 
-Value *ErrorV(const char *Str) { Error(Str); return 0; }
+  // 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 '+': 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)
+  Function *CalleeF = getFunction(Callee);
+  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");
 }
 
-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(CondV, 
-                              ConstantFP::get(getGlobalContext(), APFloat(0.0)),
-                                "ifcond");
-  
+  CondV = Builder.CreateFCmpONE(
+      CondV, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "ifcond");
+
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
-  
+
   // Create blocks for the then and else cases.  Insert the 'then' block at the
   // end of the function.
-  BasicBlock *ThenBB = BasicBlock::Create(getGlobalContext(), "then", TheFunction);
+  BasicBlock *ThenBB =
+      BasicBlock::Create(getGlobalContext(), "then", TheFunction);
   BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
   BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
-  
+
   Builder.CreateCondBr(CondV, ThenBB, ElseBB);
-  
+
   // Emit then value.
   Builder.SetInsertPoint(ThenBB);
-  
-  Value *ThenV = Then->Codegen();
-  if (ThenV == 0) return 0;
-  
+
+  Value *ThenV = Then->codegen();
+  if (!ThenV)
+    return nullptr;
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
   ThenBB = Builder.GetInsertBlock();
-  
+
   // Emit else block.
   TheFunction->getBasicBlockList().push_back(ElseBB);
   Builder.SetInsertPoint(ElseBB);
-  
-  Value *ElseV = Else->Codegen();
-  if (ElseV == 0) return 0;
-  
+
+  Value *ElseV = Else->codegen();
+  if (!ElseV)
+    return nullptr;
+
   Builder.CreateBr(MergeBB);
   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
   ElseBB = Builder.GetInsertBlock();
-  
+
   // Emit merge block.
   TheFunction->getBasicBlockList().push_back(MergeBB);
   Builder.SetInsertPoint(MergeBB);
-  PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
-                                  "iftmp");
-  
+  PHINode *PN =
+      Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, "iftmp");
+
   PN->addIncoming(ThenV, ThenBB);
   PN->addIncoming(ElseV, ElseBB);
   return PN;
 }
 
-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.
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
   BasicBlock *PreheaderBB = Builder.GetInsertBlock();
-  BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
-  
+  BasicBlock *LoopBB =
+      BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
+
   // Insert an explicit fall through from the current block to the LoopBB.
   Builder.CreateBr(LoopBB);
 
   // Start insertion in LoopBB.
   Builder.SetInsertPoint(LoopBB);
-  
+
   // Start the PHI node with an entry for Start.
-  PHINode *Variable = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, VarName.c_str());
+  PHINode *Variable = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()),
+                                        2, VarName.c_str());
   Variable->addIncoming(StartVal, PreheaderBB);
-  
+
   // Within the loop, the variable is defined equal to the PHI node.  If it
   // shadows an existing variable, we have to restore it, so save it now.
   Value *OldVal = NamedValues[VarName];
   NamedValues[VarName] = Variable;
-  
+
   // Emit the body of the loop.  This, like any other expr, can change the
   // current BB.  Note that we ignore the value computed by the body, but don't
   // allow an error.
-  if (Body->Codegen() == 0)
-    return 0;
-  
+  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));
   }
-  
+
   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(EndCond, 
-                              ConstantFP::get(getGlobalContext(), APFloat(0.0)),
-                                  "loopcond");
-  
+  EndCond = Builder.CreateFCmpONE(
+      EndCond, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "loopcond");
+
   // Create the "after loop" block and insert it.
   BasicBlock *LoopEndBB = Builder.GetInsertBlock();
-  BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
-  
+  BasicBlock *AfterBB =
+      BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
+
   // Insert the conditional branch into the end of LoopEndBB.
   Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
-  
+
   // Any new code will be inserted in AfterBB.
   Builder.SetInsertPoint(AfterBB);
-  
+
   // Add a new entry to the PHI node for the backedge.
   Variable->addIncoming(NextVar, LoopEndBB);
-  
+
   // Restore the unshadowed variable.
   if (OldVal)
     NamedValues[VarName] = OldVal;
   else
     NamedValues.erase(VarName);
 
-  
   // for expr always returns 0.0.
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
 
-Function *PrototypeAST::Codegen() {
+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() {
+  // 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;
   }
-  
+
   // 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.
@@ -743,10 +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.
@@ -756,15 +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()) {
-      // 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.
@@ -777,11 +880,20 @@ 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;
     }
   }
 }
@@ -791,9 +903,14 @@ static void MainLoop() {
 //===----------------------------------------------------------------------===//
 
 /// putchard - putchar that takes a double and returns 0.
-extern "C" 
-double putchard(double X) {
-  putchar((char)X);
+extern "C" double putchard(double 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;
 }
 
@@ -803,58 +920,26 @@ double putchard(double X) {
 
 int main() {
   InitializeNativeTarget();
-  LLVMContext &Context = getGlobalContext();
+  InitializeNativeTargetAsmPrinter();
+  InitializeNativeTargetAsmParser();
 
   // 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);
-
-  // Create the JIT.  This takes ownership of the module.
-  std::string ErrStr;
-  TheExecutionEngine = EngineBuilder(TheModule).setErrorStr(&ErrStr).create();
-  if (!TheExecutionEngine) {
-    fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
-    exit(1);
-  }
-
-  FunctionPassManager OurFPM(TheModule);
+  TheJIT = llvm::make_unique<KaleidoscopeJIT>();
 
-  // Set up the optimizer pipeline.  Start with registering info about how the
-  // target lays out data structures.
-  OurFPM.add(new DataLayoutPass(*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();
-
-  // 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;
 }