src/llvm/examples/Kaleidoscope/Chapter8/toy.cpp

   1 #include "llvm/ADT/Triple.h"
   2 #include "llvm/Analysis/Passes.h"
   3 #include "llvm/ExecutionEngine/ExecutionEngine.h"
   4 #include "llvm/ExecutionEngine/MCJIT.h"
   5 #include "llvm/ExecutionEngine/SectionMemoryManager.h"
   6 #include "llvm/IR/DataLayout.h"
   7 #include "llvm/IR/DerivedTypes.h"
   8 #include "llvm/IR/DIBuilder.h"
   9 #include "llvm/IR/IRBuilder.h"
  10 #include "llvm/IR/LLVMContext.h"
  11 #include "llvm/IR/Module.h"
  12 #include "llvm/IR/Verifier.h"
  13 #include "llvm/PassManager.h"
  14 #include "llvm/Support/Host.h"
  15 #include "llvm/Support/TargetSelect.h"
  16 #include "llvm/Transforms/Scalar.h"
  17 #include <cctype>
  18 #include <cstdio>
  19 #include <map>
  20 #include <string>
  21 #include <vector>
  22 #include <iostream>
  23 using namespace llvm;
  24
  25 //===----------------------------------------------------------------------===//
  26 // Lexer
  27 //===----------------------------------------------------------------------===//
  28
  29 // The lexer returns tokens [0-255] if it is an unknown character, otherwise one
  30 // of these for known things.
  31 enum Token {
  32   tok_eof = -1,
  33
  34   // commands
  35   tok_def = -2,
  36   tok_extern = -3,
  37
  38   // primary
  39   tok_identifier = -4,
  40   tok_number = -5,
  41
  42   // control
  43   tok_if = -6,
  44   tok_then = -7,
  45   tok_else = -8,
  46   tok_for = -9,
  47   tok_in = -10,
  48
  49   // operators
  50   tok_binary = -11,
  51   tok_unary = -12,
  52
  53   // var definition
  54   tok_var = -13
  55 };
  56
  57 std::string getTokName(int Tok) {
  58   switch (Tok) {
  59   case tok_eof:
  60     return "eof";
  61   case tok_def:
  62     return "def";
  63   case tok_extern:
  64     return "extern";
  65   case tok_identifier:
  66     return "identifier";
  67   case tok_number:
  68     return "number";
  69   case tok_if:
  70     return "if";
  71   case tok_then:
  72     return "then";
  73   case tok_else:
  74     return "else";
  75   case tok_for:
  76     return "for";
  77   case tok_in:
  78     return "in";
  79   case tok_binary:
  80     return "binary";
  81   case tok_unary:
  82     return "unary";
  83   case tok_var:
  84     return "var";
  85   }
  86   return std::string(1, (char)Tok);
  87 }
  88
  89 namespace {
  90 class PrototypeAST;
  91 class ExprAST;
  92 }
  93 static IRBuilder<> Builder(getGlobalContext());
  94 struct DebugInfo {
  95   DICompileUnit TheCU;
  96   DIType DblTy;
  97   std::vector<DIScope *> LexicalBlocks;
  98   std::map<const PrototypeAST *, DIScope> FnScopeMap;
  99
 100   void emitLocation(ExprAST *AST);
 101   DIType getDoubleTy();
 102 } KSDbgInfo;
 103
 104 static std::string IdentifierStr; // Filled in if tok_identifier
 105 static double NumVal;             // Filled in if tok_number
 106 struct SourceLocation {
 107   int Line;
 108   int Col;
 109 };
 110 static SourceLocation CurLoc;
 111 static SourceLocation LexLoc = { 1, 0 };
 112
 113 static int advance() {
 114   int LastChar = getchar();
 115
 116   if (LastChar == '\n' || LastChar == '\r') {
 117     LexLoc.Line++;
 118     LexLoc.Col = 0;
 119   } else
 120     LexLoc.Col++;
 121   return LastChar;
 122 }
 123
 124 /// gettok - Return the next token from standard input.
 125 static int gettok() {
 126   static int LastChar = ' ';
 127
 128   // Skip any whitespace.
 129   while (isspace(LastChar))
 130     LastChar = advance();
 131
 132   CurLoc = LexLoc;
 133
 134   if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
 135     IdentifierStr = LastChar;
 136     while (isalnum((LastChar = advance())))
 137       IdentifierStr += LastChar;
 138
 139     if (IdentifierStr == "def")
 140       return tok_def;
 141     if (IdentifierStr == "extern")
 142       return tok_extern;
 143     if (IdentifierStr == "if")
 144       return tok_if;
 145     if (IdentifierStr == "then")
 146       return tok_then;
 147     if (IdentifierStr == "else")
 148       return tok_else;
 149     if (IdentifierStr == "for")
 150       return tok_for;
 151     if (IdentifierStr == "in")
 152       return tok_in;
 153     if (IdentifierStr == "binary")
 154       return tok_binary;
 155     if (IdentifierStr == "unary")
 156       return tok_unary;
 157     if (IdentifierStr == "var")
 158       return tok_var;
 159     return tok_identifier;
 160   }
 161
 162   if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
 163     std::string NumStr;
 164     do {
 165       NumStr += LastChar;
 166       LastChar = advance();
 167     } while (isdigit(LastChar) || LastChar == '.');
 168
 169     NumVal = strtod(NumStr.c_str(), 0);
 170     return tok_number;
 171   }
 172
 173   if (LastChar == '#') {
 174     // Comment until end of line.
 175     do
 176       LastChar = advance();
 177     while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
 178
 179     if (LastChar != EOF)
 180       return gettok();
 181   }
 182
 183   // Check for end of file.  Don't eat the EOF.
 184   if (LastChar == EOF)
 185     return tok_eof;
 186
 187   // Otherwise, just return the character as its ascii value.
 188   int ThisChar = LastChar;
 189   LastChar = advance();
 190   return ThisChar;
 191 }
 192
 193 //===----------------------------------------------------------------------===//
 194 // Abstract Syntax Tree (aka Parse Tree)
 195 //===----------------------------------------------------------------------===//
 196 namespace {
 197
 198 std::ostream &indent(std::ostream &O, int size) {
 199   return O << std::string(size, ' ');
 200 }
 201
 202 /// ExprAST - Base class for all expression nodes.
 203 class ExprAST {
 204   SourceLocation Loc;
 205
 206 public:
 207   int getLine() const { return Loc.Line; }
 208   int getCol() const { return Loc.Col; }
 209   ExprAST(SourceLocation Loc = CurLoc) : Loc(Loc) {}
 210   virtual std::ostream &dump(std::ostream &out, int ind) {
 211     return out << ':' << getLine() << ':' << getCol() << '\n';
 212   }
 213   virtual ~ExprAST() {}
 214   virtual Value *Codegen() = 0;
 215 };
 216
 217 /// NumberExprAST - Expression class for numeric literals like "1.0".
 218 class NumberExprAST : public ExprAST {
 219   double Val;
 220
 221 public:
 222   NumberExprAST(double val) : Val(val) {}
 223   virtual std::ostream &dump(std::ostream &out, int ind) {
 224     return ExprAST::dump(out << Val, ind);
 225   }
 226   virtual Value *Codegen();
 227 };
 228
 229 /// VariableExprAST - Expression class for referencing a variable, like "a".
 230 class VariableExprAST : public ExprAST {
 231   std::string Name;
 232
 233 public:
 234   VariableExprAST(SourceLocation Loc, const std::string &name)
 235       : ExprAST(Loc), Name(name) {}
 236   const std::string &getName() const { return Name; }
 237   virtual std::ostream &dump(std::ostream &out, int ind) {
 238     return ExprAST::dump(out << Name, ind);
 239   }
 240   virtual Value *Codegen();
 241 };
 242
 243 /// UnaryExprAST - Expression class for a unary operator.
 244 class UnaryExprAST : public ExprAST {
 245   char Opcode;
 246   ExprAST *Operand;
 247
 248 public:
 249   UnaryExprAST(char opcode, ExprAST *operand)
 250       : Opcode(opcode), Operand(operand) {}
 251   virtual std::ostream &dump(std::ostream &out, int ind) {
 252     ExprAST::dump(out << "unary" << Opcode, ind);
 253     Operand->dump(out, ind + 1);
 254     return out;
 255   }
 256   virtual Value *Codegen();
 257 };
 258
 259 /// BinaryExprAST - Expression class for a binary operator.
 260 class BinaryExprAST : public ExprAST {
 261   char Op;
 262   ExprAST *LHS, *RHS;
 263
 264 public:
 265   BinaryExprAST(SourceLocation Loc, char op, ExprAST *lhs, ExprAST *rhs)
 266       : ExprAST(Loc), Op(op), LHS(lhs), RHS(rhs) {}
 267   virtual std::ostream &dump(std::ostream &out, int ind) {
 268     ExprAST::dump(out << "binary" << Op, ind);
 269     LHS->dump(indent(out, ind) << "LHS:", ind + 1);
 270     RHS->dump(indent(out, ind) << "RHS:", ind + 1);
 271     return out;
 272   }
 273   virtual Value *Codegen();
 274 };
 275
 276 /// CallExprAST - Expression class for function calls.
 277 class CallExprAST : public ExprAST {
 278   std::string Callee;
 279   std::vector<ExprAST *> Args;
 280
 281 public:
 282   CallExprAST(SourceLocation Loc, const std::string &callee,
 283               std::vector<ExprAST *> &args)
 284       : ExprAST(Loc), Callee(callee), Args(args) {}
 285   virtual std::ostream &dump(std::ostream &out, int ind) {
 286     ExprAST::dump(out << "call " << Callee, ind);
 287     for (ExprAST *Arg : Args)
 288       Arg->dump(indent(out, ind + 1), ind + 1);
 289     return out;
 290   }
 291   virtual Value *Codegen();
 292 };
 293
 294 /// IfExprAST - Expression class for if/then/else.
 295 class IfExprAST : public ExprAST {
 296   ExprAST *Cond, *Then, *Else;
 297
 298 public:
 299   IfExprAST(SourceLocation Loc, ExprAST *cond, ExprAST *then, ExprAST *_else)
 300       : ExprAST(Loc), Cond(cond), Then(then), Else(_else) {}
 301   virtual std::ostream &dump(std::ostream &out, int ind) {
 302     ExprAST::dump(out << "if", ind);
 303     Cond->dump(indent(out, ind) << "Cond:", ind + 1);
 304     Then->dump(indent(out, ind) << "Then:", ind + 1);
 305     Else->dump(indent(out, ind) << "Else:", ind + 1);
 306     return out;
 307   }
 308   virtual Value *Codegen();
 309 };
 310
 311 /// ForExprAST - Expression class for for/in.
 312 class ForExprAST : public ExprAST {
 313   std::string VarName;
 314   ExprAST *Start, *End, *Step, *Body;
 315
 316 public:
 317   ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
 318              ExprAST *step, ExprAST *body)
 319       : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
 320   virtual std::ostream &dump(std::ostream &out, int ind) {
 321     ExprAST::dump(out << "for", ind);
 322     Start->dump(indent(out, ind) << "Cond:", ind + 1);
 323     End->dump(indent(out, ind) << "End:", ind + 1);
 324     Step->dump(indent(out, ind) << "Step:", ind + 1);
 325     Body->dump(indent(out, ind) << "Body:", ind + 1);
 326     return out;
 327   }
 328   virtual Value *Codegen();
 329 };
 330
 331 /// VarExprAST - Expression class for var/in
 332 class VarExprAST : public ExprAST {
 333   std::vector<std::pair<std::string, ExprAST *> > VarNames;
 334   ExprAST *Body;
 335
 336 public:
 337   VarExprAST(const std::vector<std::pair<std::string, ExprAST *> > &varnames,
 338              ExprAST *body)
 339       : VarNames(varnames), Body(body) {}
 340
 341   virtual std::ostream &dump(std::ostream &out, int ind) {
 342     ExprAST::dump(out << "var", ind);
 343     for (const auto &NamedVar : VarNames)
 344       NamedVar.second->dump(indent(out, ind) << NamedVar.first << ':', ind + 1);
 345     Body->dump(indent(out, ind) << "Body:", ind + 1);
 346     return out;
 347   }
 348   virtual Value *Codegen();
 349 };
 350
 351 /// PrototypeAST - This class represents the "prototype" for a function,
 352 /// which captures its argument names as well as if it is an operator.
 353 class PrototypeAST {
 354   std::string Name;
 355   std::vector<std::string> Args;
 356   bool isOperator;
 357   unsigned Precedence; // Precedence if a binary op.
 358   int Line;
 359
 360 public:
 361   PrototypeAST(SourceLocation Loc, const std::string &name,
 362                const std::vector<std::string> &args, bool isoperator = false,
 363                unsigned prec = 0)
 364       : Name(name), Args(args), isOperator(isoperator), Precedence(prec),
 365         Line(Loc.Line) {}
 366
 367   bool isUnaryOp() const { return isOperator && Args.size() == 1; }
 368   bool isBinaryOp() const { return isOperator && Args.size() == 2; }
 369
 370   char getOperatorName() const {
 371     assert(isUnaryOp() || isBinaryOp());
 372     return Name[Name.size() - 1];
 373   }
 374
 375   unsigned getBinaryPrecedence() const { return Precedence; }
 376
 377   Function *Codegen();
 378
 379   void CreateArgumentAllocas(Function *F);
 380   const std::vector<std::string> &getArgs() const { return Args; }
 381 };
 382
 383 /// FunctionAST - This class represents a function definition itself.
 384 class FunctionAST {
 385   PrototypeAST *Proto;
 386   ExprAST *Body;
 387
 388 public:
 389   FunctionAST(PrototypeAST *proto, ExprAST *body) : Proto(proto), Body(body) {}
 390
 391   std::ostream &dump(std::ostream &out, int ind) {
 392     indent(out, ind) << "FunctionAST\n";
 393     ++ind;
 394     indent(out, ind) << "Body:";
 395     return Body ? Body->dump(out, ind) : out << "null\n";
 396   }
 397
 398   Function *Codegen();
 399 };
 400 } // end anonymous namespace
 401
 402 //===----------------------------------------------------------------------===//
 403 // Parser
 404 //===----------------------------------------------------------------------===//
 405
 406 /// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
 407 /// token the parser is looking at.  getNextToken reads another token from the
 408 /// lexer and updates CurTok with its results.
 409 static int CurTok;
 410 static int getNextToken() { return CurTok = gettok(); }
 411
 412 /// BinopPrecedence - This holds the precedence for each binary operator that is
 413 /// defined.
 414 static std::map<char, int> BinopPrecedence;
 415
 416 /// GetTokPrecedence - Get the precedence of the pending binary operator token.
 417 static int GetTokPrecedence() {
 418   if (!isascii(CurTok))
 419     return -1;
 420
 421   // Make sure it's a declared binop.
 422   int TokPrec = BinopPrecedence[CurTok];
 423   if (TokPrec <= 0)
 424     return -1;
 425   return TokPrec;
 426 }
 427
 428 /// Error* - These are little helper functions for error handling.
 429 ExprAST *Error(const char *Str) {
 430   fprintf(stderr, "Error: %s\n", Str);
 431   return 0;
 432 }
 433 PrototypeAST *ErrorP(const char *Str) {
 434   Error(Str);
 435   return 0;
 436 }
 437 FunctionAST *ErrorF(const char *Str) {
 438   Error(Str);
 439   return 0;
 440 }
 441
 442 static ExprAST *ParseExpression();
 443
 444 /// identifierexpr
 445 ///   ::= identifier
 446 ///   ::= identifier '(' expression* ')'
 447 static ExprAST *ParseIdentifierExpr() {
 448   std::string IdName = IdentifierStr;
 449
 450   SourceLocation LitLoc = CurLoc;
 451
 452   getNextToken(); // eat identifier.
 453
 454   if (CurTok != '(') // Simple variable ref.
 455     return new VariableExprAST(LitLoc, IdName);
 456
 457   // Call.
 458   getNextToken(); // eat (
 459   std::vector<ExprAST *> Args;
 460   if (CurTok != ')') {
 461     while (1) {
 462       ExprAST *Arg = ParseExpression();
 463       if (!Arg)
 464         return 0;
 465       Args.push_back(Arg);
 466
 467       if (CurTok == ')')
 468         break;
 469
 470       if (CurTok != ',')
 471         return Error("Expected ')' or ',' in argument list");
 472       getNextToken();
 473     }
 474   }
 475
 476   // Eat the ')'.
 477   getNextToken();
 478
 479   return new CallExprAST(LitLoc, IdName, Args);
 480 }
 481
 482 /// numberexpr ::= number
 483 static ExprAST *ParseNumberExpr() {
 484   ExprAST *Result = new NumberExprAST(NumVal);
 485   getNextToken(); // consume the number
 486   return Result;
 487 }
 488
 489 /// parenexpr ::= '(' expression ')'
 490 static ExprAST *ParseParenExpr() {
 491   getNextToken(); // eat (.
 492   ExprAST *V = ParseExpression();
 493   if (!V)
 494     return 0;
 495
 496   if (CurTok != ')')
 497     return Error("expected ')'");
 498   getNextToken(); // eat ).
 499   return V;
 500 }
 501
 502 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
 503 static ExprAST *ParseIfExpr() {
 504   SourceLocation IfLoc = CurLoc;
 505
 506   getNextToken(); // eat the if.
 507
 508   // condition.
 509   ExprAST *Cond = ParseExpression();
 510   if (!Cond)
 511     return 0;
 512
 513   if (CurTok != tok_then)
 514     return Error("expected then");
 515   getNextToken(); // eat the then
 516
 517   ExprAST *Then = ParseExpression();
 518   if (Then == 0)
 519     return 0;
 520
 521   if (CurTok != tok_else)
 522     return Error("expected else");
 523
 524   getNextToken();
 525
 526   ExprAST *Else = ParseExpression();
 527   if (!Else)
 528     return 0;
 529
 530   return new IfExprAST(IfLoc, Cond, Then, Else);
 531 }
 532
 533 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
 534 static ExprAST *ParseForExpr() {
 535   getNextToken(); // eat the for.
 536
 537   if (CurTok != tok_identifier)
 538     return Error("expected identifier after for");
 539
 540   std::string IdName = IdentifierStr;
 541   getNextToken(); // eat identifier.
 542
 543   if (CurTok != '=')
 544     return Error("expected '=' after for");
 545   getNextToken(); // eat '='.
 546
 547   ExprAST *Start = ParseExpression();
 548   if (Start == 0)
 549     return 0;
 550   if (CurTok != ',')
 551     return Error("expected ',' after for start value");
 552   getNextToken();
 553
 554   ExprAST *End = ParseExpression();
 555   if (End == 0)
 556     return 0;
 557
 558   // The step value is optional.
 559   ExprAST *Step = 0;
 560   if (CurTok == ',') {
 561     getNextToken();
 562     Step = ParseExpression();
 563     if (Step == 0)
 564       return 0;
 565   }
 566
 567   if (CurTok != tok_in)
 568     return Error("expected 'in' after for");
 569   getNextToken(); // eat 'in'.
 570
 571   ExprAST *Body = ParseExpression();
 572   if (Body == 0)
 573     return 0;
 574
 575   return new ForExprAST(IdName, Start, End, Step, Body);
 576 }
 577
 578 /// varexpr ::= 'var' identifier ('=' expression)?
 579 //                    (',' identifier ('=' expression)?)* 'in' expression
 580 static ExprAST *ParseVarExpr() {
 581   getNextToken(); // eat the var.
 582
 583   std::vector<std::pair<std::string, ExprAST *> > VarNames;
 584
 585   // At least one variable name is required.
 586   if (CurTok != tok_identifier)
 587     return Error("expected identifier after var");
 588
 589   while (1) {
 590     std::string Name = IdentifierStr;
 591     getNextToken(); // eat identifier.
 592
 593     // Read the optional initializer.
 594     ExprAST *Init = 0;
 595     if (CurTok == '=') {
 596       getNextToken(); // eat the '='.
 597
 598       Init = ParseExpression();
 599       if (Init == 0)
 600         return 0;
 601     }
 602
 603     VarNames.push_back(std::make_pair(Name, Init));
 604
 605     // End of var list, exit loop.
 606     if (CurTok != ',')
 607       break;
 608     getNextToken(); // eat the ','.
 609
 610     if (CurTok != tok_identifier)
 611       return Error("expected identifier list after var");
 612   }
 613
 614   // At this point, we have to have 'in'.
 615   if (CurTok != tok_in)
 616     return Error("expected 'in' keyword after 'var'");
 617   getNextToken(); // eat 'in'.
 618
 619   ExprAST *Body = ParseExpression();
 620   if (Body == 0)
 621     return 0;
 622
 623   return new VarExprAST(VarNames, Body);
 624 }
 625
 626 /// primary
 627 ///   ::= identifierexpr
 628 ///   ::= numberexpr
 629 ///   ::= parenexpr
 630 ///   ::= ifexpr
 631 ///   ::= forexpr
 632 ///   ::= varexpr
 633 static ExprAST *ParsePrimary() {
 634   switch (CurTok) {
 635   default:
 636     return Error("unknown token when expecting an expression");
 637   case tok_identifier:
 638     return ParseIdentifierExpr();
 639   case tok_number:
 640     return ParseNumberExpr();
 641   case '(':
 642     return ParseParenExpr();
 643   case tok_if:
 644     return ParseIfExpr();
 645   case tok_for:
 646     return ParseForExpr();
 647   case tok_var:
 648     return ParseVarExpr();
 649   }
 650 }
 651
 652 /// unary
 653 ///   ::= primary
 654 ///   ::= '!' unary
 655 static ExprAST *ParseUnary() {
 656   // If the current token is not an operator, it must be a primary expr.
 657   if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
 658     return ParsePrimary();
 659
 660   // If this is a unary operator, read it.
 661   int Opc = CurTok;
 662   getNextToken();
 663   if (ExprAST *Operand = ParseUnary())
 664     return new UnaryExprAST(Opc, Operand);
 665   return 0;
 666 }
 667
 668 /// binoprhs
 669 ///   ::= ('+' unary)*
 670 static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
 671   // If this is a binop, find its precedence.
 672   while (1) {
 673     int TokPrec = GetTokPrecedence();
 674
 675     // If this is a binop that binds at least as tightly as the current binop,
 676     // consume it, otherwise we are done.
 677     if (TokPrec < ExprPrec)
 678       return LHS;
 679
 680     // Okay, we know this is a binop.
 681     int BinOp = CurTok;
 682     SourceLocation BinLoc = CurLoc;
 683     getNextToken(); // eat binop
 684
 685     // Parse the unary expression after the binary operator.
 686     ExprAST *RHS = ParseUnary();
 687     if (!RHS)
 688       return 0;
 689
 690     // If BinOp binds less tightly with RHS than the operator after RHS, let
 691     // the pending operator take RHS as its LHS.
 692     int NextPrec = GetTokPrecedence();
 693     if (TokPrec < NextPrec) {
 694       RHS = ParseBinOpRHS(TokPrec + 1, RHS);
 695       if (RHS == 0)
 696         return 0;
 697     }
 698
 699     // Merge LHS/RHS.
 700     LHS = new BinaryExprAST(BinLoc, BinOp, LHS, RHS);
 701   }
 702 }
 703
 704 /// expression
 705 ///   ::= unary binoprhs
 706 ///
 707 static ExprAST *ParseExpression() {
 708   ExprAST *LHS = ParseUnary();
 709   if (!LHS)
 710     return 0;
 711
 712   return ParseBinOpRHS(0, LHS);
 713 }
 714
 715 /// prototype
 716 ///   ::= id '(' id* ')'
 717 ///   ::= binary LETTER number? (id, id)
 718 ///   ::= unary LETTER (id)
 719 static PrototypeAST *ParsePrototype() {
 720   std::string FnName;
 721
 722   SourceLocation FnLoc = CurLoc;
 723
 724   unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
 725   unsigned BinaryPrecedence = 30;
 726
 727   switch (CurTok) {
 728   default:
 729     return ErrorP("Expected function name in prototype");
 730   case tok_identifier:
 731     FnName = IdentifierStr;
 732     Kind = 0;
 733     getNextToken();
 734     break;
 735   case tok_unary:
 736     getNextToken();
 737     if (!isascii(CurTok))
 738       return ErrorP("Expected unary operator");
 739     FnName = "unary";
 740     FnName += (char)CurTok;
 741     Kind = 1;
 742     getNextToken();
 743     break;
 744   case tok_binary:
 745     getNextToken();
 746     if (!isascii(CurTok))
 747       return ErrorP("Expected binary operator");
 748     FnName = "binary";
 749     FnName += (char)CurTok;
 750     Kind = 2;
 751     getNextToken();
 752
 753     // Read the precedence if present.
 754     if (CurTok == tok_number) {
 755       if (NumVal < 1 || NumVal > 100)
 756         return ErrorP("Invalid precedecnce: must be 1..100");
 757       BinaryPrecedence = (unsigned)NumVal;
 758       getNextToken();
 759     }
 760     break;
 761   }
 762
 763   if (CurTok != '(')
 764     return ErrorP("Expected '(' in prototype");
 765
 766   std::vector<std::string> ArgNames;
 767   while (getNextToken() == tok_identifier)
 768     ArgNames.push_back(IdentifierStr);
 769   if (CurTok != ')')
 770     return ErrorP("Expected ')' in prototype");
 771
 772   // success.
 773   getNextToken(); // eat ')'.
 774
 775   // Verify right number of names for operator.
 776   if (Kind && ArgNames.size() != Kind)
 777     return ErrorP("Invalid number of operands for operator");
 778
 779   return new PrototypeAST(FnLoc, FnName, ArgNames, Kind != 0, BinaryPrecedence);
 780 }
 781
 782 /// definition ::= 'def' prototype expression
 783 static FunctionAST *ParseDefinition() {
 784   getNextToken(); // eat def.
 785   PrototypeAST *Proto = ParsePrototype();
 786   if (Proto == 0)
 787     return 0;
 788
 789   if (ExprAST *E = ParseExpression())
 790     return new FunctionAST(Proto, E);
 791   return 0;
 792 }
 793
 794 /// toplevelexpr ::= expression
 795 static FunctionAST *ParseTopLevelExpr() {
 796   SourceLocation FnLoc = CurLoc;
 797   if (ExprAST *E = ParseExpression()) {
 798     // Make an anonymous proto.
 799     PrototypeAST *Proto =
 800         new PrototypeAST(FnLoc, "main", std::vector<std::string>());
 801     return new FunctionAST(Proto, E);
 802   }
 803   return 0;
 804 }
 805
 806 /// external ::= 'extern' prototype
 807 static PrototypeAST *ParseExtern() {
 808   getNextToken(); // eat extern.
 809   return ParsePrototype();
 810 }
 811
 812 //===----------------------------------------------------------------------===//
 813 // Debug Info Support
 814 //===----------------------------------------------------------------------===//
 815
 816 static DIBuilder *DBuilder;
 817
 818 DIType DebugInfo::getDoubleTy() {
 819   if (DblTy.isValid())
 820     return DblTy;
 821
 822   DblTy = DBuilder->createBasicType("double", 64, 64, dwarf::DW_ATE_float);
 823   return DblTy;
 824 }
 825
 826 void DebugInfo::emitLocation(ExprAST *AST) {
 827   if (!AST)
 828     return Builder.SetCurrentDebugLocation(DebugLoc());
 829   DIScope *Scope;
 830   if (LexicalBlocks.empty())
 831     Scope = &TheCU;
 832   else
 833     Scope = LexicalBlocks.back();
 834   Builder.SetCurrentDebugLocation(
 835       DebugLoc::get(AST->getLine(), AST->getCol(), DIScope(*Scope)));
 836 }
 837
 838 static DICompositeType CreateFunctionType(unsigned NumArgs, DIFile Unit) {
 839   SmallVector<Metadata *, 8> EltTys;
 840   DIType DblTy = KSDbgInfo.getDoubleTy();
 841
 842   // Add the result type.
 843   EltTys.push_back(DblTy);
 844
 845   for (unsigned i = 0, e = NumArgs; i != e; ++i)
 846     EltTys.push_back(DblTy);
 847
 848   DITypeArray EltTypeArray = DBuilder->getOrCreateTypeArray(EltTys);
 849   return DBuilder->createSubroutineType(Unit, EltTypeArray);
 850 }
 851
 852 //===----------------------------------------------------------------------===//
 853 // Code Generation
 854 //===----------------------------------------------------------------------===//
 855
 856 static Module *TheModule;
 857 static std::map<std::string, AllocaInst *> NamedValues;
 858 static FunctionPassManager *TheFPM;
 859
 860 Value *ErrorV(const char *Str) {
 861   Error(Str);
 862   return 0;
 863 }
 864
 865 /// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
 866 /// the function.  This is used for mutable variables etc.
 867 static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
 868                                           const std::string &VarName) {
 869   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
 870                    TheFunction->getEntryBlock().begin());
 871   return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
 872                            VarName.c_str());
 873 }
 874
 875 Value *NumberExprAST::Codegen() {
 876   KSDbgInfo.emitLocation(this);
 877   return ConstantFP::get(getGlobalContext(), APFloat(Val));
 878 }
 879
 880 Value *VariableExprAST::Codegen() {
 881   // Look this variable up in the function.
 882   Value *V = NamedValues[Name];
 883   if (V == 0)
 884     return ErrorV("Unknown variable name");
 885
 886   KSDbgInfo.emitLocation(this);
 887   // Load the value.
 888   return Builder.CreateLoad(V, Name.c_str());
 889 }
 890
 891 Value *UnaryExprAST::Codegen() {
 892   Value *OperandV = Operand->Codegen();
 893   if (OperandV == 0)
 894     return 0;
 895
 896   Function *F = TheModule->getFunction(std::string("unary") + Opcode);
 897   if (F == 0)
 898     return ErrorV("Unknown unary operator");
 899
 900   KSDbgInfo.emitLocation(this);
 901   return Builder.CreateCall(F, OperandV, "unop");
 902 }
 903
 904 Value *BinaryExprAST::Codegen() {
 905   KSDbgInfo.emitLocation(this);
 906
 907   // Special case '=' because we don't want to emit the LHS as an expression.
 908   if (Op == '=') {
 909     // Assignment requires the LHS to be an identifier.
 910     VariableExprAST *LHSE = dynamic_cast<VariableExprAST *>(LHS);
 911     if (!LHSE)
 912       return ErrorV("destination of '=' must be a variable");
 913     // Codegen the RHS.
 914     Value *Val = RHS->Codegen();
 915     if (Val == 0)
 916       return 0;
 917
 918     // Look up the name.
 919     Value *Variable = NamedValues[LHSE->getName()];
 920     if (Variable == 0)
 921       return ErrorV("Unknown variable name");
 922
 923     Builder.CreateStore(Val, Variable);
 924     return Val;
 925   }
 926
 927   Value *L = LHS->Codegen();
 928   Value *R = RHS->Codegen();
 929   if (L == 0 || R == 0)
 930     return 0;
 931
 932   switch (Op) {
 933   case '+':
 934     return Builder.CreateFAdd(L, R, "addtmp");
 935   case '-':
 936     return Builder.CreateFSub(L, R, "subtmp");
 937   case '*':
 938     return Builder.CreateFMul(L, R, "multmp");
 939   case '<':
 940     L = Builder.CreateFCmpULT(L, R, "cmptmp");
 941     // Convert bool 0/1 to double 0.0 or 1.0
 942     return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
 943                                 "booltmp");
 944   default:
 945     break;
 946   }
 947
 948   // If it wasn't a builtin binary operator, it must be a user defined one. Emit
 949   // a call to it.
 950   Function *F = TheModule->getFunction(std::string("binary") + Op);
 951   assert(F && "binary operator not found!");
 952
 953   Value *Ops[] = { L, R };
 954   return Builder.CreateCall(F, Ops, "binop");
 955 }
 956
 957 Value *CallExprAST::Codegen() {
 958   KSDbgInfo.emitLocation(this);
 959
 960   // Look up the name in the global module table.
 961   Function *CalleeF = TheModule->getFunction(Callee);
 962   if (CalleeF == 0)
 963     return ErrorV("Unknown function referenced");
 964
 965   // If argument mismatch error.
 966   if (CalleeF->arg_size() != Args.size())
 967     return ErrorV("Incorrect # arguments passed");
 968
 969   std::vector<Value *> ArgsV;
 970   for (unsigned i = 0, e = Args.size(); i != e; ++i) {
 971     ArgsV.push_back(Args[i]->Codegen());
 972     if (ArgsV.back() == 0)
 973       return 0;
 974   }
 975
 976   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 977 }
 978
 979 Value *IfExprAST::Codegen() {
 980   KSDbgInfo.emitLocation(this);
 981
 982   Value *CondV = Cond->Codegen();
 983   if (CondV == 0)
 984     return 0;
 985
 986   // Convert condition to a bool by comparing equal to 0.0.
 987   CondV = Builder.CreateFCmpONE(
 988       CondV, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "ifcond");
 989
 990   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 991
 992   // Create blocks for the then and else cases.  Insert the 'then' block at the
 993   // end of the function.
 994   BasicBlock *ThenBB =
 995       BasicBlock::Create(getGlobalContext(), "then", TheFunction);
 996   BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
 997   BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
 998
 999   Builder.CreateCondBr(CondV, ThenBB, ElseBB);
1000
1001   // Emit then value.
1002   Builder.SetInsertPoint(ThenBB);
1003
1004   Value *ThenV = Then->Codegen();
1005   if (ThenV == 0)
1006     return 0;
1007
1008   Builder.CreateBr(MergeBB);
1009   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
1010   ThenBB = Builder.GetInsertBlock();
1011
1012   // Emit else block.
1013   TheFunction->getBasicBlockList().push_back(ElseBB);
1014   Builder.SetInsertPoint(ElseBB);
1015
1016   Value *ElseV = Else->Codegen();
1017   if (ElseV == 0)
1018     return 0;
1019
1020   Builder.CreateBr(MergeBB);
1021   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
1022   ElseBB = Builder.GetInsertBlock();
1023
1024   // Emit merge block.
1025   TheFunction->getBasicBlockList().push_back(MergeBB);
1026   Builder.SetInsertPoint(MergeBB);
1027   PHINode *PN =
1028       Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, "iftmp");
1029
1030   PN->addIncoming(ThenV, ThenBB);
1031   PN->addIncoming(ElseV, ElseBB);
1032   return PN;
1033 }
1034
1035 Value *ForExprAST::Codegen() {
1036   // Output this as:
1037   //   var = alloca double
1038   //   ...
1039   //   start = startexpr
1040   //   store start -> var
1041   //   goto loop
1042   // loop:
1043   //   ...
1044   //   bodyexpr
1045   //   ...
1046   // loopend:
1047   //   step = stepexpr
1048   //   endcond = endexpr
1049   //
1050   //   curvar = load var
1051   //   nextvar = curvar + step
1052   //   store nextvar -> var
1053   //   br endcond, loop, endloop
1054   // outloop:
1055
1056   Function *TheFunction = Builder.GetInsertBlock()->getParent();
1057
1058   // Create an alloca for the variable in the entry block.
1059   AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
1060
1061   KSDbgInfo.emitLocation(this);
1062
1063   // Emit the start code first, without 'variable' in scope.
1064   Value *StartVal = Start->Codegen();
1065   if (StartVal == 0)
1066     return 0;
1067
1068   // Store the value into the alloca.
1069   Builder.CreateStore(StartVal, Alloca);
1070
1071   // Make the new basic block for the loop header, inserting after current
1072   // block.
1073   BasicBlock *LoopBB =
1074       BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
1075
1076   // Insert an explicit fall through from the current block to the LoopBB.
1077   Builder.CreateBr(LoopBB);
1078
1079   // Start insertion in LoopBB.
1080   Builder.SetInsertPoint(LoopBB);
1081
1082   // Within the loop, the variable is defined equal to the PHI node.  If it
1083   // shadows an existing variable, we have to restore it, so save it now.
1084   AllocaInst *OldVal = NamedValues[VarName];
1085   NamedValues[VarName] = Alloca;
1086
1087   // Emit the body of the loop.  This, like any other expr, can change the
1088   // current BB.  Note that we ignore the value computed by the body, but don't
1089   // allow an error.
1090   if (Body->Codegen() == 0)
1091     return 0;
1092
1093   // Emit the step value.
1094   Value *StepVal;
1095   if (Step) {
1096     StepVal = Step->Codegen();
1097     if (StepVal == 0)
1098       return 0;
1099   } else {
1100     // If not specified, use 1.0.
1101     StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
1102   }
1103
1104   // Compute the end condition.
1105   Value *EndCond = End->Codegen();
1106   if (EndCond == 0)
1107     return EndCond;
1108
1109   // Reload, increment, and restore the alloca.  This handles the case where
1110   // the body of the loop mutates the variable.
1111   Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
1112   Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
1113   Builder.CreateStore(NextVar, Alloca);
1114
1115   // Convert condition to a bool by comparing equal to 0.0.
1116   EndCond = Builder.CreateFCmpONE(
1117       EndCond, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "loopcond");
1118
1119   // Create the "after loop" block and insert it.
1120   BasicBlock *AfterBB =
1121       BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
1122
1123   // Insert the conditional branch into the end of LoopEndBB.
1124   Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
1125
1126   // Any new code will be inserted in AfterBB.
1127   Builder.SetInsertPoint(AfterBB);
1128
1129   // Restore the unshadowed variable.
1130   if (OldVal)
1131     NamedValues[VarName] = OldVal;
1132   else
1133     NamedValues.erase(VarName);
1134
1135   // for expr always returns 0.0.
1136   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
1137 }
1138
1139 Value *VarExprAST::Codegen() {
1140   std::vector<AllocaInst *> OldBindings;
1141
1142   Function *TheFunction = Builder.GetInsertBlock()->getParent();
1143
1144   // Register all variables and emit their initializer.
1145   for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
1146     const std::string &VarName = VarNames[i].first;
1147     ExprAST *Init = VarNames[i].second;
1148
1149     // Emit the initializer before adding the variable to scope, this prevents
1150     // the initializer from referencing the variable itself, and permits stuff
1151     // like this:
1152     //  var a = 1 in
1153     //    var a = a in ...   # refers to outer 'a'.
1154     Value *InitVal;
1155     if (Init) {
1156       InitVal = Init->Codegen();
1157       if (InitVal == 0)
1158         return 0;
1159     } else { // If not specified, use 0.0.
1160       InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
1161     }
1162
1163     AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
1164     Builder.CreateStore(InitVal, Alloca);
1165
1166     // Remember the old variable binding so that we can restore the binding when
1167     // we unrecurse.
1168     OldBindings.push_back(NamedValues[VarName]);
1169
1170     // Remember this binding.
1171     NamedValues[VarName] = Alloca;
1172   }
1173
1174   KSDbgInfo.emitLocation(this);
1175
1176   // Codegen the body, now that all vars are in scope.
1177   Value *BodyVal = Body->Codegen();
1178   if (BodyVal == 0)
1179     return 0;
1180
1181   // Pop all our variables from scope.
1182   for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
1183     NamedValues[VarNames[i].first] = OldBindings[i];
1184
1185   // Return the body computation.
1186   return BodyVal;
1187 }
1188
1189 Function *PrototypeAST::Codegen() {
1190   // Make the function type:  double(double,double) etc.
1191   std::vector<Type *> Doubles(Args.size(),
1192                               Type::getDoubleTy(getGlobalContext()));
1193   FunctionType *FT =
1194       FunctionType::get(Type::getDoubleTy(getGlobalContext()), Doubles, false);
1195
1196   Function *F =
1197       Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
1198
1199   // If F conflicted, there was already something named 'Name'.  If it has a
1200   // body, don't allow redefinition or reextern.
1201   if (F->getName() != Name) {
1202     // Delete the one we just made and get the existing one.
1203     F->eraseFromParent();
1204     F = TheModule->getFunction(Name);
1205
1206     // If F already has a body, reject this.
1207     if (!F->empty()) {
1208       ErrorF("redefinition of function");
1209       return 0;
1210     }
1211
1212     // If F took a different number of args, reject.
1213     if (F->arg_size() != Args.size()) {
1214       ErrorF("redefinition of function with different # args");
1215       return 0;
1216     }
1217   }
1218
1219   // Set names for all arguments.
1220   unsigned Idx = 0;
1221   for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
1222        ++AI, ++Idx)
1223     AI->setName(Args[Idx]);
1224
1225   // Create a subprogram DIE for this function.
1226   DIFile Unit = DBuilder->createFile(KSDbgInfo.TheCU.getFilename(),
1227                                      KSDbgInfo.TheCU.getDirectory());
1228   DIDescriptor FContext(Unit);
1229   unsigned LineNo = Line;
1230   unsigned ScopeLine = Line;
1231   DISubprogram SP = DBuilder->createFunction(
1232       FContext, Name, StringRef(), Unit, LineNo,
1233       CreateFunctionType(Args.size(), Unit), false /* internal linkage */,
1234       true /* definition */, ScopeLine, DIDescriptor::FlagPrototyped, false, F);
1235
1236   KSDbgInfo.FnScopeMap[this] = SP;
1237   return F;
1238 }
1239
1240 /// CreateArgumentAllocas - Create an alloca for each argument and register the
1241 /// argument in the symbol table so that references to it will succeed.
1242 void PrototypeAST::CreateArgumentAllocas(Function *F) {
1243   Function::arg_iterator AI = F->arg_begin();
1244   for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
1245     // Create an alloca for this variable.
1246     AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
1247
1248     // Create a debug descriptor for the variable.
1249     DIScope *Scope = KSDbgInfo.LexicalBlocks.back();
1250     DIFile Unit = DBuilder->createFile(KSDbgInfo.TheCU.getFilename(),
1251                                        KSDbgInfo.TheCU.getDirectory());
1252     DIVariable D = DBuilder->createLocalVariable(dwarf::DW_TAG_arg_variable,
1253                                                  *Scope, Args[Idx], Unit, Line,
1254                                                  KSDbgInfo.getDoubleTy(), Idx);
1255
1256     Instruction *Call = DBuilder->insertDeclare(
1257         Alloca, D, DBuilder->createExpression(), Builder.GetInsertBlock());
1258     Call->setDebugLoc(DebugLoc::get(Line, 0, *Scope));
1259
1260     // Store the initial value into the alloca.
1261     Builder.CreateStore(AI, Alloca);
1262
1263     // Add arguments to variable symbol table.
1264     NamedValues[Args[Idx]] = Alloca;
1265   }
1266 }
1267
1268 Function *FunctionAST::Codegen() {
1269   NamedValues.clear();
1270
1271   Function *TheFunction = Proto->Codegen();
1272   if (TheFunction == 0)
1273     return 0;
1274
1275   // Push the current scope.
1276   KSDbgInfo.LexicalBlocks.push_back(&KSDbgInfo.FnScopeMap[Proto]);
1277
1278   // Unset the location for the prologue emission (leading instructions with no
1279   // location in a function are considered part of the prologue and the debugger
1280   // will run past them when breaking on a function)
1281   KSDbgInfo.emitLocation(nullptr);
1282
1283   // If this is an operator, install it.
1284   if (Proto->isBinaryOp())
1285     BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
1286
1287   // Create a new basic block to start insertion into.
1288   BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
1289   Builder.SetInsertPoint(BB);
1290
1291   // Add all arguments to the symbol table and create their allocas.
1292   Proto->CreateArgumentAllocas(TheFunction);
1293
1294   KSDbgInfo.emitLocation(Body);
1295
1296   if (Value *RetVal = Body->Codegen()) {
1297     // Finish off the function.
1298     Builder.CreateRet(RetVal);
1299
1300     // Pop off the lexical block for the function.
1301     KSDbgInfo.LexicalBlocks.pop_back();
1302
1303     // Validate the generated code, checking for consistency.
1304     verifyFunction(*TheFunction);
1305
1306     // Optimize the function.
1307     TheFPM->run(*TheFunction);
1308
1309     return TheFunction;
1310   }
1311
1312   // Error reading body, remove function.
1313   TheFunction->eraseFromParent();
1314
1315   if (Proto->isBinaryOp())
1316     BinopPrecedence.erase(Proto->getOperatorName());
1317
1318   // Pop off the lexical block for the function since we added it
1319   // unconditionally.
1320   KSDbgInfo.LexicalBlocks.pop_back();
1321
1322   return 0;
1323 }
1324
1325 //===----------------------------------------------------------------------===//
1326 // Top-Level parsing and JIT Driver
1327 //===----------------------------------------------------------------------===//
1328
1329 static ExecutionEngine *TheExecutionEngine;
1330
1331 static void HandleDefinition() {
1332   if (FunctionAST *F = ParseDefinition()) {
1333     if (!F->Codegen()) {
1334       fprintf(stderr, "Error reading function definition:");
1335     }
1336   } else {
1337     // Skip token for error recovery.
1338     getNextToken();
1339   }
1340 }
1341
1342 static void HandleExtern() {
1343   if (PrototypeAST *P = ParseExtern()) {
1344     if (!P->Codegen()) {
1345       fprintf(stderr, "Error reading extern");
1346     }
1347   } else {
1348     // Skip token for error recovery.
1349     getNextToken();
1350   }
1351 }
1352
1353 static void HandleTopLevelExpression() {
1354   // Evaluate a top-level expression into an anonymous function.
1355   if (FunctionAST *F = ParseTopLevelExpr()) {
1356     if (!F->Codegen()) {
1357       fprintf(stderr, "Error generating code for top level expr");
1358     }
1359   } else {
1360     // Skip token for error recovery.
1361     getNextToken();
1362   }
1363 }
1364
1365 /// top ::= definition | external | expression | ';'
1366 static void MainLoop() {
1367   while (1) {
1368     switch (CurTok) {
1369     case tok_eof:
1370       return;
1371     case ';':
1372       getNextToken();
1373       break; // ignore top-level semicolons.
1374     case tok_def:
1375       HandleDefinition();
1376       break;
1377     case tok_extern:
1378       HandleExtern();
1379       break;
1380     default:
1381       HandleTopLevelExpression();
1382       break;
1383     }
1384   }
1385 }
1386
1387 //===----------------------------------------------------------------------===//
1388 // "Library" functions that can be "extern'd" from user code.
1389 //===----------------------------------------------------------------------===//
1390
1391 /// putchard - putchar that takes a double and returns 0.
1392 extern "C" double putchard(double X) {
1393   putchar((char)X);
1394   return 0;
1395 }
1396
1397 /// printd - printf that takes a double prints it as "%f\n", returning 0.
1398 extern "C" double printd(double X) {
1399   printf("%f\n", X);
1400   return 0;
1401 }
1402
1403 //===----------------------------------------------------------------------===//
1404 // Main driver code.
1405 //===----------------------------------------------------------------------===//
1406
1407 int main() {
1408   InitializeNativeTarget();
1409   InitializeNativeTargetAsmPrinter();
1410   InitializeNativeTargetAsmParser();
1411   LLVMContext &Context = getGlobalContext();
1412
1413   // Install standard binary operators.
1414   // 1 is lowest precedence.
1415   BinopPrecedence['='] = 2;
1416   BinopPrecedence['<'] = 10;
1417   BinopPrecedence['+'] = 20;
1418   BinopPrecedence['-'] = 20;
1419   BinopPrecedence['*'] = 40; // highest.
1420
1421   // Prime the first token.
1422   getNextToken();
1423
1424   // Make the module, which holds all the code.
1425   std::unique_ptr<Module> Owner = make_unique<Module>("my cool jit", Context);
1426   TheModule = Owner.get();
1427
1428   // Add the current debug info version into the module.
1429   TheModule->addModuleFlag(Module::Warning, "Debug Info Version",
1430                            DEBUG_METADATA_VERSION);
1431
1432   // Darwin only supports dwarf2.
1433   if (Triple(sys::getProcessTriple()).isOSDarwin())
1434     TheModule->addModuleFlag(llvm::Module::Warning, "Dwarf Version", 2);
1435
1436   // Construct the DIBuilder, we do this here because we need the module.
1437   DBuilder = new DIBuilder(*TheModule);
1438
1439   // Create the compile unit for the module.
1440   // Currently down as "fib.ks" as a filename since we're redirecting stdin
1441   // but we'd like actual source locations.
1442   KSDbgInfo.TheCU = DBuilder->createCompileUnit(
1443       dwarf::DW_LANG_C, "fib.ks", ".", "Kaleidoscope Compiler", 0, "", 0);
1444
1445   // Create the JIT.  This takes ownership of the module.
1446   std::string ErrStr;
1447   TheExecutionEngine =
1448       EngineBuilder(std::move(Owner))
1449           .setErrorStr(&ErrStr)
1450           .setMCJITMemoryManager(llvm::make_unique<SectionMemoryManager>())
1451           .create();
1452   if (!TheExecutionEngine) {
1453     fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
1454     exit(1);
1455   }
1456
1457   FunctionPassManager OurFPM(TheModule);
1458
1459   // Set up the optimizer pipeline.  Start with registering info about how the
1460   // target lays out data structures.
1461   TheModule->setDataLayout(TheExecutionEngine->getDataLayout());
1462   OurFPM.add(new DataLayoutPass());
1463 #if 0
1464   // Provide basic AliasAnalysis support for GVN.
1465   OurFPM.add(createBasicAliasAnalysisPass());
1466   // Promote allocas to registers.
1467   OurFPM.add(createPromoteMemoryToRegisterPass());
1468   // Do simple "peephole" optimizations and bit-twiddling optzns.
1469   OurFPM.add(createInstructionCombiningPass());
1470   // Reassociate expressions.
1471   OurFPM.add(createReassociatePass());
1472   // Eliminate Common SubExpressions.
1473   OurFPM.add(createGVNPass());
1474   // Simplify the control flow graph (deleting unreachable blocks, etc).
1475   OurFPM.add(createCFGSimplificationPass());
1476   #endif
1477   OurFPM.doInitialization();
1478
1479   // Set the global so the code gen can use this.
1480   TheFPM = &OurFPM;
1481
1482   // Run the main "interpreter loop" now.
1483   MainLoop();
1484
1485   TheFPM = 0;
1486
1487   // Finalize the debug info.
1488   DBuilder->finalize();
1489
1490   // Print out all of the generated code.
1491   TheModule->dump();
1492
1493   return 0;
1494 }