Remove LLVM 8.0.1 files.

1 files changed, 0 insertions, 1240 deletions

diff --git a/gnu/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter2/toy.cpp b/gnu/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter2/toy.cpp
deleted file mode 100644
index e7c3624aa04..00000000000
--- a/gnu/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter2/toy.cpp
+++ /dev/null
@@ -1,1240 +0,0 @@
-#include "llvm/ADT/APFloat.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/IRBuilder.h"
-#include "llvm/IR/LLVMContext.h"
-#include "llvm/IR/Module.h"
-#include "llvm/IR/Type.h"
-#include "llvm/IR/Verifier.h"
-#include "llvm/Support/TargetSelect.h"
-#include "llvm/Target/TargetMachine.h"
-#include "KaleidoscopeJIT.h"
-#include <algorithm>
-#include <cassert>
-#include <cctype>
-#include <cstdint>
-#include <cstdio>
-#include <cstdlib>
-#include <map>
-#include <memory>
-#include <string>
-#include <utility>
-#include <vector>
-
-using namespace llvm;
-using namespace llvm::orc;
-
-//===----------------------------------------------------------------------===//
-// Lexer
-//===----------------------------------------------------------------------===//
-
-// The lexer returns tokens [0-255] if it is an unknown character, otherwise one
-// of these for known things.
-enum Token {
-  tok_eof = -1,
-
-  // commands
-  tok_def = -2,
-  tok_extern = -3,
-
-  // primary
-  tok_identifier = -4,
-  tok_number = -5,
-
-  // control
-  tok_if = -6,
-  tok_then = -7,
-  tok_else = -8,
-  tok_for = -9,
-  tok_in = -10,
-
-  // operators
-  tok_binary = -11,
-  tok_unary = -12,
-
-  // var definition
-  tok_var = -13
-};
-
-static std::string IdentifierStr; // Filled in if tok_identifier
-static double NumVal;             // Filled in if tok_number
-
-/// gettok - Return the next token from standard input.
-static int gettok() {
-  static int LastChar = ' ';
-
-  // Skip any whitespace.
-  while (isspace(LastChar))
-    LastChar = getchar();
-
-  if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
-    IdentifierStr = LastChar;
-    while (isalnum((LastChar = getchar())))
-      IdentifierStr += LastChar;
-
-    if (IdentifierStr == "def")
-      return tok_def;
-    if (IdentifierStr == "extern")
-      return tok_extern;
-    if (IdentifierStr == "if")
-      return tok_if;
-    if (IdentifierStr == "then")
-      return tok_then;
-    if (IdentifierStr == "else")
-      return tok_else;
-    if (IdentifierStr == "for")
-      return tok_for;
-    if (IdentifierStr == "in")
-      return tok_in;
-    if (IdentifierStr == "binary")
-      return tok_binary;
-    if (IdentifierStr == "unary")
-      return tok_unary;
-    if (IdentifierStr == "var")
-      return tok_var;
-    return tok_identifier;
-  }
-
-  if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
-    std::string NumStr;
-    do {
-      NumStr += LastChar;
-      LastChar = getchar();
-    } while (isdigit(LastChar) || LastChar == '.');
-
-    NumVal = strtod(NumStr.c_str(), nullptr);
-    return tok_number;
-  }
-
-  if (LastChar == '#') {
-    // Comment until end of line.
-    do
-      LastChar = getchar();
-    while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
-
-    if (LastChar != EOF)
-      return gettok();
-  }
-
-  // Check for end of file.  Don't eat the EOF.
-  if (LastChar == EOF)
-    return tok_eof;
-
-  // Otherwise, just return the character as its ascii value.
-  int ThisChar = LastChar;
-  LastChar = getchar();
-  return ThisChar;
-}
-
-//===----------------------------------------------------------------------===//
-// Abstract Syntax Tree (aka Parse Tree)
-//===----------------------------------------------------------------------===//
-
-namespace {
-
-/// ExprAST - Base class for all expression nodes.
-class ExprAST {
-public:
-  virtual ~ExprAST() = default;
-
-  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;
-};
-
-/// 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;
-  const std::string &getName() const { return Name; }
-};
-
-/// UnaryExprAST - Expression class for a unary operator.
-class UnaryExprAST : public ExprAST {
-  char Opcode;
-  std::unique_ptr<ExprAST> Operand;
-
-public:
-  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;
-  std::unique_ptr<ExprAST> LHS, RHS;
-
-public:
-  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<std::unique_ptr<ExprAST>> Args;
-
-public:
-  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 {
-  std::unique_ptr<ExprAST> Cond, Then, Else;
-
-public:
-  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;
-  std::unique_ptr<ExprAST> Start, End, Step, Body;
-
-public:
-  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, std::unique_ptr<ExprAST>>> VarNames;
-  std::unique_ptr<ExprAST> Body;
-
-public:
-  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 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;
-  unsigned Precedence; // Precedence if a binary op.
-
-public:
-  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; }
-
-  char getOperatorName() const {
-    assert(isUnaryOp() || isBinaryOp());
-    return Name[Name.size() - 1];
-  }
-
-  unsigned getBinaryPrecedence() const { return Precedence; }
-};
-
-/// FunctionAST - This class represents a function definition itself.
-class FunctionAST {
-  std::unique_ptr<PrototypeAST> Proto;
-  std::unique_ptr<ExprAST> Body;
-
-public:
-  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
-              std::unique_ptr<ExprAST> Body)
-      : Proto(std::move(Proto)), Body(std::move(Body)) {}
-
-  Function *codegen();
-};
-
-} // end anonymous namespace
-
-//===----------------------------------------------------------------------===//
-// Parser
-//===----------------------------------------------------------------------===//
-
-/// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
-/// token the parser is looking at.  getNextToken reads another token from the
-/// lexer and updates CurTok with its results.
-static int CurTok;
-static int getNextToken() { return CurTok = gettok(); }
-
-/// BinopPrecedence - This holds the precedence for each binary operator that is
-/// defined.
-static std::map<char, int> BinopPrecedence;
-
-/// GetTokPrecedence - Get the precedence of the pending binary operator token.
-static int GetTokPrecedence() {
-  if (!isascii(CurTok))
-    return -1;
-
-  // Make sure it's a declared binop.
-  int TokPrec = BinopPrecedence[CurTok];
-  if (TokPrec <= 0)
-    return -1;
-  return TokPrec;
-}
-
-/// LogError* - These are little helper functions for error handling.
-std::unique_ptr<ExprAST> LogError(const char *Str) {
-  fprintf(stderr, "Error: %s\n", Str);
-  return nullptr;
-}
-
-std::unique_ptr<PrototypeAST> LogErrorP(const char *Str) {
-  LogError(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);
-}
-
-/// parenexpr ::= '(' expression ')'
-static std::unique_ptr<ExprAST> ParseParenExpr() {
-  getNextToken(); // eat (.
-  auto V = ParseExpression();
-  if (!V)
-    return nullptr;
-
-  if (CurTok != ')')
-    return LogError("expected ')'");
-  getNextToken(); // eat ).
-  return V;
-}
-
-/// identifierexpr
-///   ::= identifier
-///   ::= identifier '(' expression* ')'
-static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
-  std::string IdName = IdentifierStr;
-
-  getNextToken(); // eat identifier.
-
-  if (CurTok != '(') // Simple variable ref.
-    return llvm::make_unique<VariableExprAST>(IdName);
-
-  // Call.
-  getNextToken(); // eat (
-  std::vector<std::unique_ptr<ExprAST>> Args;
-  if (CurTok != ')') {
-    while (true) {
-      if (auto Arg = ParseExpression())
-        Args.push_back(std::move(Arg));
-      else
-        return nullptr;
-
-      if (CurTok == ')')
-        break;
-
-      if (CurTok != ',')
-        return LogError("Expected ')' or ',' in argument list");
-      getNextToken();
-    }
-  }
-
-  // Eat the ')'.
-  getNextToken();
-
-  return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
-}
-
-/// 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 LogError("expected then");
-  getNextToken(); // eat the then
-
-  auto Then = ParseExpression();
-  if (!Then)
-    return nullptr;
-
-  if (CurTok != tok_else)
-    return LogError("expected else");
-
-  getNextToken();
-
-  auto Else = ParseExpression();
-  if (!Else)
-    return nullptr;
-
-  return llvm::make_unique<IfExprAST>(std::move(Cond), std::move(Then),
-                                      std::move(Else));
-}
-
-/// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
-static std::unique_ptr<ExprAST> ParseForExpr() {
-  getNextToken(); // eat the for.
-
-  if (CurTok != tok_identifier)
-    return LogError("expected identifier after for");
-
-  std::string IdName = IdentifierStr;
-  getNextToken(); // eat identifier.
-
-  if (CurTok != '=')
-    return LogError("expected '=' after for");
-  getNextToken(); // eat '='.
-
-  auto Start = ParseExpression();
-  if (!Start)
-    return nullptr;
-  if (CurTok != ',')
-    return LogError("expected ',' after for start value");
-  getNextToken();
-
-  auto End = ParseExpression();
-  if (!End)
-    return nullptr;
-
-  // The step value is optional.
-  std::unique_ptr<ExprAST> Step;
-  if (CurTok == ',') {
-    getNextToken();
-    Step = ParseExpression();
-    if (!Step)
-      return nullptr;
-  }
-
-  if (CurTok != tok_in)
-    return LogError("expected 'in' after for");
-  getNextToken(); // eat 'in'.
-
-  auto Body = ParseExpression();
-  if (!Body)
-    return nullptr;
-
-  return llvm::make_unique<ForExprAST>(IdName, std::move(Start), std::move(End),
-                                       std::move(Step), std::move(Body));
-}
-
-/// varexpr ::= 'var' identifier ('=' expression)?
-//                    (',' identifier ('=' expression)?)* 'in' expression
-static std::unique_ptr<ExprAST> ParseVarExpr() {
-  getNextToken(); // eat the var.
-
-  std::vector<std::pair<std::string, std::unique_ptr<ExprAST>>> VarNames;
-
-  // At least one variable name is required.
-  if (CurTok != tok_identifier)
-    return LogError("expected identifier after var");
-
-  while (true) {
-    std::string Name = IdentifierStr;
-    getNextToken(); // eat identifier.
-
-    // Read the optional initializer.
-    std::unique_ptr<ExprAST> Init = nullptr;
-    if (CurTok == '=') {
-      getNextToken(); // eat the '='.
-
-      Init = ParseExpression();
-      if (!Init)
-        return nullptr;
-    }
-
-    VarNames.push_back(std::make_pair(Name, std::move(Init)));
-
-    // End of var list, exit loop.
-    if (CurTok != ',')
-      break;
-    getNextToken(); // eat the ','.
-
-    if (CurTok != tok_identifier)
-      return LogError("expected identifier list after var");
-  }
-
-  // At this point, we have to have 'in'.
-  if (CurTok != tok_in)
-    return LogError("expected 'in' keyword after 'var'");
-  getNextToken(); // eat 'in'.
-
-  auto Body = ParseExpression();
-  if (!Body)
-    return nullptr;
-
-  return llvm::make_unique<VarExprAST>(std::move(VarNames), std::move(Body));
-}
-
-/// primary
-///   ::= identifierexpr
-///   ::= numberexpr
-///   ::= parenexpr
-///   ::= ifexpr
-///   ::= forexpr
-///   ::= varexpr
-static std::unique_ptr<ExprAST> ParsePrimary() {
-  switch (CurTok) {
-  default:
-    return LogError("unknown token when expecting an expression");
-  case tok_identifier:
-    return ParseIdentifierExpr();
-  case tok_number:
-    return ParseNumberExpr();
-  case '(':
-    return ParseParenExpr();
-  case tok_if:
-    return ParseIfExpr();
-  case tok_for:
-    return ParseForExpr();
-  case tok_var:
-    return ParseVarExpr();
-  }
-}
-
-/// unary
-///   ::= primary
-///   ::= '!' unary
-static std::unique_ptr<ExprAST> ParseUnary() {
-  // If the current token is not an operator, it must be a primary expr.
-  if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
-    return ParsePrimary();
-
-  // If this is a unary operator, read it.
-  int Opc = CurTok;
-  getNextToken();
-  if (auto Operand = ParseUnary())
-    return llvm::make_unique<UnaryExprAST>(Opc, std::move(Operand));
-  return nullptr;
-}
-
-/// binoprhs
-///   ::= ('+' unary)*
-static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
-                                              std::unique_ptr<ExprAST> LHS) {
-  // If this is a binop, find its precedence.
-  while (true) {
-    int TokPrec = GetTokPrecedence();
-
-    // If this is a binop that binds at least as tightly as the current binop,
-    // consume it, otherwise we are done.
-    if (TokPrec < ExprPrec)
-      return LHS;
-
-    // Okay, we know this is a binop.
-    int BinOp = CurTok;
-    getNextToken(); // eat binop
-
-    // Parse the unary expression after the binary operator.
-    auto RHS = ParseUnary();
-    if (!RHS)
-      return nullptr;
-
-    // If BinOp binds less tightly with RHS than the operator after RHS, let
-    // the pending operator take RHS as its LHS.
-    int NextPrec = GetTokPrecedence();
-    if (TokPrec < NextPrec) {
-      RHS = ParseBinOpRHS(TokPrec + 1, std::move(RHS));
-      if (!RHS)
-        return nullptr;
-    }
-
-    // Merge LHS/RHS.
-    LHS =
-        llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
-  }
-}
-
-/// expression
-///   ::= unary binoprhs
-///
-static std::unique_ptr<ExprAST> ParseExpression() {
-  auto LHS = ParseUnary();
-  if (!LHS)
-    return nullptr;
-
-  return ParseBinOpRHS(0, std::move(LHS));
-}
-
-/// prototype
-///   ::= id '(' id* ')'
-///   ::= binary LETTER number? (id, id)
-///   ::= unary LETTER (id)
-static std::unique_ptr<PrototypeAST> ParsePrototype() {
-  std::string FnName;
-
-  unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
-  unsigned BinaryPrecedence = 30;
-
-  switch (CurTok) {
-  default:
-    return LogErrorP("Expected function name in prototype");
-  case tok_identifier:
-    FnName = IdentifierStr;
-    Kind = 0;
-    getNextToken();
-    break;
-  case tok_unary:
-    getNextToken();
-    if (!isascii(CurTok))
-      return LogErrorP("Expected unary operator");
-    FnName = "unary";
-    FnName += (char)CurTok;
-    Kind = 1;
-    getNextToken();
-    break;
-  case tok_binary:
-    getNextToken();
-    if (!isascii(CurTok))
-      return LogErrorP("Expected binary operator");
-    FnName = "binary";
-    FnName += (char)CurTok;
-    Kind = 2;
-    getNextToken();
-
-    // Read the precedence if present.
-    if (CurTok == tok_number) {
-      if (NumVal < 1 || NumVal > 100)
-        return LogErrorP("Invalid precedecnce: must be 1..100");
-      BinaryPrecedence = (unsigned)NumVal;
-      getNextToken();
-    }
-    break;
-  }
-
-  if (CurTok != '(')
-    return LogErrorP("Expected '(' in prototype");
-
-  std::vector<std::string> ArgNames;
-  while (getNextToken() == tok_identifier)
-    ArgNames.push_back(IdentifierStr);
-  if (CurTok != ')')
-    return LogErrorP("Expected ')' in prototype");
-
-  // success.
-  getNextToken(); // eat ')'.
-
-  // Verify right number of names for operator.
-  if (Kind && ArgNames.size() != Kind)
-    return LogErrorP("Invalid number of operands for operator");
-
-  return llvm::make_unique<PrototypeAST>(FnName, ArgNames, Kind != 0,
-                                         BinaryPrecedence);
-}
-
-/// definition ::= 'def' prototype expression
-static std::unique_ptr<FunctionAST> ParseDefinition() {
-  getNextToken(); // eat def.
-  auto Proto = ParsePrototype();
-  if (!Proto)
-    return nullptr;
-
-  if (auto E = ParseExpression())
-    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
-  return nullptr;
-}
-
-/// toplevelexpr ::= expression
-static std::unique_ptr<FunctionAST> ParseTopLevelExpr(unsigned ExprCount) {
-  if (auto E = ParseExpression()) {
-    // Make an anonymous proto.
-    auto Proto = llvm::make_unique<PrototypeAST>(
-        ("__anon_expr" + Twine(ExprCount)).str(), std::vector<std::string>());
-    return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
-  }
-  return nullptr;
-}
-
-/// external ::= 'extern' prototype
-static std::unique_ptr<PrototypeAST> ParseExtern() {
-  getNextToken(); // eat extern.
-  return ParsePrototype();
-}
-
-//===----------------------------------------------------------------------===//
-// Code Generation
-//===----------------------------------------------------------------------===//
-
-static std::unique_ptr<KaleidoscopeJIT> TheJIT;
-static LLVMContext *TheContext;
-static std::unique_ptr<IRBuilder<>> Builder;
-static std::unique_ptr<Module> TheModule;
-static std::map<std::string, AllocaInst *> NamedValues;
-static std::map<std::string, std::unique_ptr<PrototypeAST>> FunctionProtos;
-static ExitOnError ExitOnErr;
-
-Value *LogErrorV(const char *Str) {
-  LogError(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();
-
-  // If no existing prototype exists, return null.
-  return nullptr;
-}
-
-/// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
-/// the function.  This is used for mutable variables etc.
-static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
-                                          const std::string &VarName) {
-  IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
-                   TheFunction->getEntryBlock().begin());
-  return TmpB.CreateAlloca(Type::getDoubleTy(*TheContext), nullptr, VarName);
-}
-
-Value *NumberExprAST::codegen() {
-  return ConstantFP::get(*TheContext, APFloat(Val));
-}
-
-Value *VariableExprAST::codegen() {
-  // Look this variable up in the function.
-  Value *V = NamedValues[Name];
-  if (!V)
-    return LogErrorV("Unknown variable name");
-
-  // Load the value.
-  return Builder->CreateLoad(V, Name.c_str());
-}
-
-Value *UnaryExprAST::codegen() {
-  Value *OperandV = Operand->codegen();
-  if (!OperandV)
-    return nullptr;
-
-  Function *F = getFunction(std::string("unary") + Opcode);
-  if (!F)
-    return LogErrorV("Unknown unary operator");
-
-  return Builder->CreateCall(F, OperandV, "unop");
-}
-
-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.get());
-    if (!LHSE)
-      return LogErrorV("destination of '=' must be a variable");
-    // Codegen the RHS.
-    Value *Val = RHS->codegen();
-    if (!Val)
-      return nullptr;
-
-    // Look up the name.
-    Value *Variable = NamedValues[LHSE->getName()];
-    if (!Variable)
-      return LogErrorV("Unknown variable name");
-
-    Builder->CreateStore(Val, Variable);
-    return Val;
-  }
-
-  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 '<':
-    L = Builder->CreateFCmpULT(L, R, "cmptmp");
-    // Convert bool 0/1 to double 0.0 or 1.0
-    return Builder->CreateUIToFP(L, Type::getDoubleTy(*TheContext), "booltmp");
-  default:
-    break;
-  }
-
-  // If it wasn't a builtin binary operator, it must be a user defined one. Emit
-  // a call to it.
-  Function *F = getFunction(std::string("binary") + Op);
-  assert(F && "binary operator not found!");
-
-  Value *Ops[] = {L, R};
-  return Builder->CreateCall(F, Ops, "binop");
-}
-
-Value *CallExprAST::codegen() {
-  // Look up the name in the global module table.
-  Function *CalleeF = getFunction(Callee);
-  if (!CalleeF)
-    return LogErrorV("Unknown function referenced");
-
-  // If argument mismatch error.
-  if (CalleeF->arg_size() != Args.size())
-    return LogErrorV("Incorrect # arguments passed");
-
-  std::vector<Value *> ArgsV;
-  for (unsigned i = 0, e = Args.size(); i != e; ++i) {
-    ArgsV.push_back(Args[i]->codegen());
-    if (!ArgsV.back())
-      return nullptr;
-  }
-
-  return Builder->CreateCall(CalleeF, ArgsV, "calltmp");
-}
-
-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(*TheContext, 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(*TheContext, "then", TheFunction);
-  BasicBlock *ElseBB = BasicBlock::Create(*TheContext, "else");
-  BasicBlock *MergeBB = BasicBlock::Create(*TheContext, "ifcont");
-
-  Builder->CreateCondBr(CondV, ThenBB, ElseBB);
-
-  // Emit then value.
-  Builder->SetInsertPoint(ThenBB);
-
-  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)
-    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(*TheContext), 2, "iftmp");
-
-  PN->addIncoming(ThenV, ThenBB);
-  PN->addIncoming(ElseV, ElseBB);
-  return PN;
-}
-
-// 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)
-    return nullptr;
-
-  // Store the value into the alloca.
-  Builder->CreateStore(StartVal, Alloca);
-
-  // Make the new basic block for the loop header, inserting after current
-  // block.
-  BasicBlock *LoopBB = BasicBlock::Create(*TheContext, "loop", TheFunction);
-
-  // Insert an explicit fall through from the current block to the LoopBB.
-  Builder->CreateBr(LoopBB);
-
-  // Start insertion in LoopBB.
-  Builder->SetInsertPoint(LoopBB);
-
-  // Within the loop, the variable is defined equal to the PHI node.  If it
-  // shadows an existing variable, we have to restore it, so save it now.
-  AllocaInst *OldVal = NamedValues[VarName];
-  NamedValues[VarName] = Alloca;
-
-  // Emit the body of the loop.  This, like any other expr, can change the
-  // current BB.  Note that we ignore the value computed by the body, but don't
-  // allow an error.
-  if (!Body->codegen())
-    return nullptr;
-
-  // Emit the step value.
-  Value *StepVal = nullptr;
-  if (Step) {
-    StepVal = Step->codegen();
-    if (!StepVal)
-      return nullptr;
-  } else {
-    // If not specified, use 1.0.
-    StepVal = ConstantFP::get(*TheContext, APFloat(1.0));
-  }
-
-  // Compute the end condition.
-  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.
-  Value *CurVar = Builder->CreateLoad(Alloca, VarName.c_str());
-  Value *NextVar = Builder->CreateFAdd(CurVar, StepVal, "nextvar");
-  Builder->CreateStore(NextVar, Alloca);
-
-  // Convert condition to a bool by comparing equal to 0.0.
-  EndCond = Builder->CreateFCmpONE(
-      EndCond, ConstantFP::get(*TheContext, APFloat(0.0)), "loopcond");
-
-  // Create the "after loop" block and insert it.
-  BasicBlock *AfterBB =
-      BasicBlock::Create(*TheContext, "afterloop", TheFunction);
-
-  // Insert the conditional branch into the end of LoopEndBB.
-  Builder->CreateCondBr(EndCond, LoopBB, AfterBB);
-
-  // Any new code will be inserted in AfterBB.
-  Builder->SetInsertPoint(AfterBB);
-
-  // Restore the unshadowed variable.
-  if (OldVal)
-    NamedValues[VarName] = OldVal;
-  else
-    NamedValues.erase(VarName);
-
-  // for expr always returns 0.0.
-  return Constant::getNullValue(Type::getDoubleTy(*TheContext));
-}
-
-Value *VarExprAST::codegen() {
-  std::vector<AllocaInst *> OldBindings;
-
-  Function *TheFunction = Builder->GetInsertBlock()->getParent();
-
-  // Register all variables and emit their initializer.
-  for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
-    const std::string &VarName = VarNames[i].first;
-    ExprAST *Init = VarNames[i].second.get();
-
-    // Emit the initializer before adding the variable to scope, this prevents
-    // the initializer from referencing the variable itself, and permits stuff
-    // like this:
-    //  var a = 1 in
-    //    var a = a in ...   # refers to outer 'a'.
-    Value *InitVal;
-    if (Init) {
-      InitVal = Init->codegen();
-      if (!InitVal)
-        return nullptr;
-    } else { // If not specified, use 0.0.
-      InitVal = ConstantFP::get(*TheContext, APFloat(0.0));
-    }
-
-    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
-    Builder->CreateStore(InitVal, Alloca);
-
-    // Remember the old variable binding so that we can restore the binding when
-    // we unrecurse.
-    OldBindings.push_back(NamedValues[VarName]);
-
-    // Remember this binding.
-    NamedValues[VarName] = Alloca;
-  }
-
-  // Codegen the body, now that all vars are in scope.
-  Value *BodyVal = Body->codegen();
-  if (!BodyVal)
-    return nullptr;
-
-  // Pop all our variables from scope.
-  for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
-    NamedValues[VarNames[i].first] = OldBindings[i];
-
-  // Return the body computation.
-  return BodyVal;
-}
-
-Function *PrototypeAST::codegen() {
-  // Make the function type:  double(double,double) etc.
-  std::vector<Type *> Doubles(Args.size(), Type::getDoubleTy(*TheContext));
-  FunctionType *FT =
-      FunctionType::get(Type::getDoubleTy(*TheContext), Doubles, false);
-
-  Function *F =
-      Function::Create(FT, Function::ExternalLinkage, Name, TheModule.get());
-
-  // Set names for all arguments.
-  unsigned Idx = 0;
-  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(*TheContext, "entry", TheFunction);
-  Builder->SetInsertPoint(BB);
-
-  // 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()) {
-    // Finish off the function.
-    Builder->CreateRet(RetVal);
-
-    // Validate the generated code, checking for consistency.
-    verifyFunction(*TheFunction);
-
-    return TheFunction;
-  }
-
-  // Error reading body, remove function.
-  TheFunction->eraseFromParent();
-
-  if (P.isBinaryOp())
-    BinopPrecedence.erase(P.getOperatorName());
-  return nullptr;
-}
-
-//===----------------------------------------------------------------------===//
-// Top-Level parsing and JIT Driver
-//===----------------------------------------------------------------------===//
-
-static void InitializeModule() {
-  // Open a new module.
-  TheModule = llvm::make_unique<Module>("my cool jit", *TheContext);
-  TheModule->setDataLayout(TheJIT->getDataLayout());
-
-  // Create a new builder for the module.
-  Builder = llvm::make_unique<IRBuilder<>>(*TheContext);
-}
-
-static void HandleDefinition() {
-  if (auto FnAST = ParseDefinition()) {
-    if (auto *FnIR = FnAST->codegen()) {
-      fprintf(stderr, "Read function definition:");
-      FnIR->print(errs());
-      fprintf(stderr, "\n");
-      ExitOnErr(TheJIT->addModule(std::move(TheModule)));
-      InitializeModule();
-    }
-  } else {
-    // Skip token for error recovery.
-    getNextToken();
-  }
-}
-
-static void HandleExtern() {
-  if (auto ProtoAST = ParseExtern()) {
-    if (auto *FnIR = ProtoAST->codegen()) {
-      fprintf(stderr, "Read extern: ");
-      FnIR->print(errs());
-      fprintf(stderr, "\n");
-      FunctionProtos[ProtoAST->getName()] = std::move(ProtoAST);
-    }
-  } else {
-    // Skip token for error recovery.
-    getNextToken();
-  }
-}
-
-static void HandleTopLevelExpression() {
-  static unsigned ExprCount = 0;
-
-  // Update ExprCount. This number will be added to anonymous expressions to
-  // prevent them from clashing.
-  ++ExprCount;
-
-  // Evaluate a top-level expression into an anonymous function.
-  if (auto FnAST = ParseTopLevelExpr(ExprCount)) {
-    if (FnAST->codegen()) {
-      // JIT the module containing the anonymous expression, keeping a handle so
-      // we can free it later.
-      ExitOnErr(TheJIT->addModule(std::move(TheModule)));
-      InitializeModule();
-
-      // Get the anonymous expression's JITSymbol.
-      auto Sym =
-          ExitOnErr(TheJIT->lookup(("__anon_expr" + Twine(ExprCount)).str()));
-
-      auto *FP = (double (*)())(intptr_t)Sym.getAddress();
-      assert(FP && "Failed to codegen function");
-      fprintf(stderr, "Evaluated to %f\n", FP());
-    }
-  } else {
-    // Skip token for error recovery.
-    getNextToken();
-  }
-}
-
-/// top ::= definition | external | expression | ';'
-static void MainLoop() {
-  while (true) {
-    fprintf(stderr, "ready> ");
-    switch (CurTok) {
-    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) {
-  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;
-}
-
-//===----------------------------------------------------------------------===//
-// Main driver code.
-//===----------------------------------------------------------------------===//
-
-int main() {
-  InitializeNativeTarget();
-  InitializeNativeTargetAsmPrinter();
-  InitializeNativeTargetAsmParser();
-
-  // Install standard binary operators.
-  // 1 is lowest precedence.
-  BinopPrecedence['='] = 2;
-  BinopPrecedence['<'] = 10;
-  BinopPrecedence['+'] = 20;
-  BinopPrecedence['-'] = 20;
-  BinopPrecedence['*'] = 40; // highest.
-
-  // Prime the first token.
-  fprintf(stderr, "ready> ");
-  getNextToken();
-
-  TheJIT = ExitOnErr(KaleidoscopeJIT::Create());
-  TheContext = &TheJIT->getContext();
-
-  InitializeModule();
-
-  // Run the main "interpreter loop" now.
-  MainLoop();
-
-  return 0;
-}