examples/Kaleidoscope/MCJIT/cached/toy-jit.cpp

   1 #define MINIMAL_STDERR_OUTPUT
   2
   3 #include "llvm/Analysis/Passes.h"
   4 #include "llvm/ExecutionEngine/ExecutionEngine.h"
   5 #include "llvm/IR/DataLayout.h"
   6 #include "llvm/IR/DerivedTypes.h"
   7 #include "llvm/IR/IRBuilder.h"
   8 #include "llvm/IR/LLVMContext.h"
   9 #include "llvm/IR/LegacyPassManager.h"
  10 #include "llvm/IR/Module.h"
  11 #include "llvm/IR/Verifier.h"
  12 #include "llvm/IRReader/IRReader.h"
  13 #include "llvm/Support/CommandLine.h"
  14 #include "llvm/Support/SourceMgr.h"
  15 #include "llvm/Support/TargetSelect.h"
  16 #include "llvm/Support/raw_ostream.h"
  17 #include "llvm/Transforms/Scalar.h"
  18 #include <cctype>
  19 #include <cstdio>
  20 #include <map>
  21 #include <string>
  22 #include <vector>
  23
  24 using namespace llvm;
  25
  26 //===----------------------------------------------------------------------===//
  27 // Command-line options
  28 //===----------------------------------------------------------------------===//
  29
  30 namespace {
  31   cl::opt<std::string>
  32   InputIR("input-IR",
  33               cl::desc("Specify the name of an IR file to load for function definitions"),
  34               cl::value_desc("input IR file name"));
  35 } // namespace
  36
  37 //===----------------------------------------------------------------------===//
  38 // Lexer
  39 //===----------------------------------------------------------------------===//
  40
  41 // The lexer returns tokens [0-255] if it is an unknown character, otherwise one
  42 // of these for known things.
  43 enum Token {
  44   tok_eof = -1,
  45
  46   // commands
  47   tok_def = -2, tok_extern = -3,
  48
  49   // primary
  50   tok_identifier = -4, tok_number = -5,
  51
  52   // control
  53   tok_if = -6, tok_then = -7, tok_else = -8,
  54   tok_for = -9, tok_in = -10,
  55
  56   // operators
  57   tok_binary = -11, tok_unary = -12,
  58
  59   // var definition
  60   tok_var = -13
  61 };
  62
  63 static std::string IdentifierStr;  // Filled in if tok_identifier
  64 static double NumVal;              // Filled in if tok_number
  65
  66 /// gettok - Return the next token from standard input.
  67 static int gettok() {
  68   static int LastChar = ' ';
  69
  70   // Skip any whitespace.
  71   while (isspace(LastChar))
  72     LastChar = getchar();
  73
  74   if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
  75     IdentifierStr = LastChar;
  76     while (isalnum((LastChar = getchar())))
  77       IdentifierStr += LastChar;
  78
  79     if (IdentifierStr == "def") return tok_def;
  80     if (IdentifierStr == "extern") return tok_extern;
  81     if (IdentifierStr == "if") return tok_if;
  82     if (IdentifierStr == "then") return tok_then;
  83     if (IdentifierStr == "else") return tok_else;
  84     if (IdentifierStr == "for") return tok_for;
  85     if (IdentifierStr == "in") return tok_in;
  86     if (IdentifierStr == "binary") return tok_binary;
  87     if (IdentifierStr == "unary") return tok_unary;
  88     if (IdentifierStr == "var") return tok_var;
  89     return tok_identifier;
  90   }
  91
  92   if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
  93     std::string NumStr;
  94     do {
  95       NumStr += LastChar;
  96       LastChar = getchar();
  97     } while (isdigit(LastChar) || LastChar == '.');
  98
  99     NumVal = strtod(NumStr.c_str(), 0);
 100     return tok_number;
 101   }
 102
 103   if (LastChar == '#') {
 104     // Comment until end of line.
 105     do LastChar = getchar();
 106     while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
 107
 108     if (LastChar != EOF)
 109       return gettok();
 110   }
 111
 112   // Check for end of file.  Don't eat the EOF.
 113   if (LastChar == EOF)
 114     return tok_eof;
 115
 116   // Otherwise, just return the character as its ascii value.
 117   int ThisChar = LastChar;
 118   LastChar = getchar();
 119   return ThisChar;
 120 }
 121
 122 //===----------------------------------------------------------------------===//
 123 // Abstract Syntax Tree (aka Parse Tree)
 124 //===----------------------------------------------------------------------===//
 125
 126 /// ExprAST - Base class for all expression nodes.
 127 class ExprAST {
 128 public:
 129   virtual ~ExprAST() {}
 130   virtual Value *Codegen() = 0;
 131 };
 132
 133 /// NumberExprAST - Expression class for numeric literals like "1.0".
 134 class NumberExprAST : public ExprAST {
 135   double Val;
 136 public:
 137   NumberExprAST(double val) : Val(val) {}
 138   virtual Value *Codegen();
 139 };
 140
 141 /// VariableExprAST - Expression class for referencing a variable, like "a".
 142 class VariableExprAST : public ExprAST {
 143   std::string Name;
 144 public:
 145   VariableExprAST(const std::string &name) : Name(name) {}
 146   const std::string &getName() const { return Name; }
 147   virtual Value *Codegen();
 148 };
 149
 150 /// UnaryExprAST - Expression class for a unary operator.
 151 class UnaryExprAST : public ExprAST {
 152   char Opcode;
 153   ExprAST *Operand;
 154 public:
 155   UnaryExprAST(char opcode, ExprAST *operand)
 156     : Opcode(opcode), Operand(operand) {}
 157   virtual Value *Codegen();
 158 };
 159
 160 /// BinaryExprAST - Expression class for a binary operator.
 161 class BinaryExprAST : public ExprAST {
 162   char Op;
 163   ExprAST *LHS, *RHS;
 164 public:
 165   BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
 166     : Op(op), LHS(lhs), RHS(rhs) {}
 167   virtual Value *Codegen();
 168 };
 169
 170 /// CallExprAST - Expression class for function calls.
 171 class CallExprAST : public ExprAST {
 172   std::string Callee;
 173   std::vector<ExprAST*> Args;
 174 public:
 175   CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
 176     : Callee(callee), Args(args) {}
 177   virtual Value *Codegen();
 178 };
 179
 180 /// IfExprAST - Expression class for if/then/else.
 181 class IfExprAST : public ExprAST {
 182   ExprAST *Cond, *Then, *Else;
 183 public:
 184   IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
 185   : Cond(cond), Then(then), Else(_else) {}
 186   virtual Value *Codegen();
 187 };
 188
 189 /// ForExprAST - Expression class for for/in.
 190 class ForExprAST : public ExprAST {
 191   std::string VarName;
 192   ExprAST *Start, *End, *Step, *Body;
 193 public:
 194   ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
 195              ExprAST *step, ExprAST *body)
 196     : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
 197   virtual Value *Codegen();
 198 };
 199
 200 /// VarExprAST - Expression class for var/in
 201 class VarExprAST : public ExprAST {
 202   std::vector<std::pair<std::string, ExprAST*> > VarNames;
 203   ExprAST *Body;
 204 public:
 205   VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
 206              ExprAST *body)
 207   : VarNames(varnames), Body(body) {}
 208
 209   virtual Value *Codegen();
 210 };
 211
 212 /// PrototypeAST - This class represents the "prototype" for a function,
 213 /// which captures its argument names as well as if it is an operator.
 214 class PrototypeAST {
 215   std::string Name;
 216   std::vector<std::string> Args;
 217   bool isOperator;
 218   unsigned Precedence;  // Precedence if a binary op.
 219 public:
 220   PrototypeAST(const std::string &name, const std::vector<std::string> &args,
 221                bool isoperator = false, unsigned prec = 0)
 222   : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
 223
 224   bool isUnaryOp() const { return isOperator && Args.size() == 1; }
 225   bool isBinaryOp() const { return isOperator && Args.size() == 2; }
 226
 227   char getOperatorName() const {
 228     assert(isUnaryOp() || isBinaryOp());
 229     return Name[Name.size()-1];
 230   }
 231
 232   unsigned getBinaryPrecedence() const { return Precedence; }
 233
 234   Function *Codegen();
 235
 236   void CreateArgumentAllocas(Function *F);
 237 };
 238
 239 /// FunctionAST - This class represents a function definition itself.
 240 class FunctionAST {
 241   PrototypeAST *Proto;
 242   ExprAST *Body;
 243 public:
 244   FunctionAST(PrototypeAST *proto, ExprAST *body)
 245     : Proto(proto), Body(body) {}
 246
 247   Function *Codegen();
 248 };
 249
 250 //===----------------------------------------------------------------------===//
 251 // Parser
 252 //===----------------------------------------------------------------------===//
 253
 254 /// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
 255 /// token the parser is looking at.  getNextToken reads another token from the
 256 /// lexer and updates CurTok with its results.
 257 static int CurTok;
 258 static int getNextToken() {
 259   return CurTok = gettok();
 260 }
 261
 262 /// BinopPrecedence - This holds the precedence for each binary operator that is
 263 /// defined.
 264 static std::map<char, int> BinopPrecedence;
 265
 266 /// GetTokPrecedence - Get the precedence of the pending binary operator token.
 267 static int GetTokPrecedence() {
 268   if (!isascii(CurTok))
 269     return -1;
 270
 271   // Make sure it's a declared binop.
 272   int TokPrec = BinopPrecedence[CurTok];
 273   if (TokPrec <= 0) return -1;
 274   return TokPrec;
 275 }
 276
 277 /// Error* - These are little helper functions for error handling.
 278 ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
 279 PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
 280 FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
 281
 282 static ExprAST *ParseExpression();
 283
 284 /// identifierexpr
 285 ///   ::= identifier
 286 ///   ::= identifier '(' expression* ')'
 287 static ExprAST *ParseIdentifierExpr() {
 288   std::string IdName = IdentifierStr;
 289
 290   getNextToken();  // eat identifier.
 291
 292   if (CurTok != '(') // Simple variable ref.
 293     return new VariableExprAST(IdName);
 294
 295   // Call.
 296   getNextToken();  // eat (
 297   std::vector<ExprAST*> Args;
 298   if (CurTok != ')') {
 299     while (1) {
 300       ExprAST *Arg = ParseExpression();
 301       if (!Arg) return 0;
 302       Args.push_back(Arg);
 303
 304       if (CurTok == ')') break;
 305
 306       if (CurTok != ',')
 307         return Error("Expected ')' or ',' in argument list");
 308       getNextToken();
 309     }
 310   }
 311
 312   // Eat the ')'.
 313   getNextToken();
 314
 315   return new CallExprAST(IdName, Args);
 316 }
 317
 318 /// numberexpr ::= number
 319 static ExprAST *ParseNumberExpr() {
 320   ExprAST *Result = new NumberExprAST(NumVal);
 321   getNextToken(); // consume the number
 322   return Result;
 323 }
 324
 325 /// parenexpr ::= '(' expression ')'
 326 static ExprAST *ParseParenExpr() {
 327   getNextToken();  // eat (.
 328   ExprAST *V = ParseExpression();
 329   if (!V) return 0;
 330
 331   if (CurTok != ')')
 332     return Error("expected ')'");
 333   getNextToken();  // eat ).
 334   return V;
 335 }
 336
 337 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
 338 static ExprAST *ParseIfExpr() {
 339   getNextToken();  // eat the if.
 340
 341   // condition.
 342   ExprAST *Cond = ParseExpression();
 343   if (!Cond) return 0;
 344
 345   if (CurTok != tok_then)
 346     return Error("expected then");
 347   getNextToken();  // eat the then
 348
 349   ExprAST *Then = ParseExpression();
 350   if (Then == 0) return 0;
 351
 352   if (CurTok != tok_else)
 353     return Error("expected else");
 354
 355   getNextToken();
 356
 357   ExprAST *Else = ParseExpression();
 358   if (!Else) return 0;
 359
 360   return new IfExprAST(Cond, Then, Else);
 361 }
 362
 363 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
 364 static ExprAST *ParseForExpr() {
 365   getNextToken();  // eat the for.
 366
 367   if (CurTok != tok_identifier)
 368     return Error("expected identifier after for");
 369
 370   std::string IdName = IdentifierStr;
 371   getNextToken();  // eat identifier.
 372
 373   if (CurTok != '=')
 374     return Error("expected '=' after for");
 375   getNextToken();  // eat '='.
 376
 377
 378   ExprAST *Start = ParseExpression();
 379   if (Start == 0) return 0;
 380   if (CurTok != ',')
 381     return Error("expected ',' after for start value");
 382   getNextToken();
 383
 384   ExprAST *End = ParseExpression();
 385   if (End == 0) return 0;
 386
 387   // The step value is optional.
 388   ExprAST *Step = 0;
 389   if (CurTok == ',') {
 390     getNextToken();
 391     Step = ParseExpression();
 392     if (Step == 0) return 0;
 393   }
 394
 395   if (CurTok != tok_in)
 396     return Error("expected 'in' after for");
 397   getNextToken();  // eat 'in'.
 398
 399   ExprAST *Body = ParseExpression();
 400   if (Body == 0) return 0;
 401
 402   return new ForExprAST(IdName, Start, End, Step, Body);
 403 }
 404
 405 /// varexpr ::= 'var' identifier ('=' expression)?
 406 //                    (',' identifier ('=' expression)?)* 'in' expression
 407 static ExprAST *ParseVarExpr() {
 408   getNextToken();  // eat the var.
 409
 410   std::vector<std::pair<std::string, ExprAST*> > VarNames;
 411
 412   // At least one variable name is required.
 413   if (CurTok != tok_identifier)
 414     return Error("expected identifier after var");
 415
 416   while (1) {
 417     std::string Name = IdentifierStr;
 418     getNextToken();  // eat identifier.
 419
 420     // Read the optional initializer.
 421     ExprAST *Init = 0;
 422     if (CurTok == '=') {
 423       getNextToken(); // eat the '='.
 424
 425       Init = ParseExpression();
 426       if (Init == 0) return 0;
 427     }
 428
 429     VarNames.push_back(std::make_pair(Name, Init));
 430
 431     // End of var list, exit loop.
 432     if (CurTok != ',') break;
 433     getNextToken(); // eat the ','.
 434
 435     if (CurTok != tok_identifier)
 436       return Error("expected identifier list after var");
 437   }
 438
 439   // At this point, we have to have 'in'.
 440   if (CurTok != tok_in)
 441     return Error("expected 'in' keyword after 'var'");
 442   getNextToken();  // eat 'in'.
 443
 444   ExprAST *Body = ParseExpression();
 445   if (Body == 0) return 0;
 446
 447   return new VarExprAST(VarNames, Body);
 448 }
 449
 450 /// primary
 451 ///   ::= identifierexpr
 452 ///   ::= numberexpr
 453 ///   ::= parenexpr
 454 ///   ::= ifexpr
 455 ///   ::= forexpr
 456 ///   ::= varexpr
 457 static ExprAST *ParsePrimary() {
 458   switch (CurTok) {
 459   default: return Error("unknown token when expecting an expression");
 460   case tok_identifier: return ParseIdentifierExpr();
 461   case tok_number:     return ParseNumberExpr();
 462   case '(':            return ParseParenExpr();
 463   case tok_if:         return ParseIfExpr();
 464   case tok_for:        return ParseForExpr();
 465   case tok_var:        return ParseVarExpr();
 466   }
 467 }
 468
 469 /// unary
 470 ///   ::= primary
 471 ///   ::= '!' unary
 472 static ExprAST *ParseUnary() {
 473   // If the current token is not an operator, it must be a primary expr.
 474   if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
 475     return ParsePrimary();
 476
 477   // If this is a unary operator, read it.
 478   int Opc = CurTok;
 479   getNextToken();
 480   if (ExprAST *Operand = ParseUnary())
 481     return new UnaryExprAST(Opc, Operand);
 482   return 0;
 483 }
 484
 485 /// binoprhs
 486 ///   ::= ('+' unary)*
 487 static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
 488   // If this is a binop, find its precedence.
 489   while (1) {
 490     int TokPrec = GetTokPrecedence();
 491
 492     // If this is a binop that binds at least as tightly as the current binop,
 493     // consume it, otherwise we are done.
 494     if (TokPrec < ExprPrec)
 495       return LHS;
 496
 497     // Okay, we know this is a binop.
 498     int BinOp = CurTok;
 499     getNextToken();  // eat binop
 500
 501     // Parse the unary expression after the binary operator.
 502     ExprAST *RHS = ParseUnary();
 503     if (!RHS) return 0;
 504
 505     // If BinOp binds less tightly with RHS than the operator after RHS, let
 506     // the pending operator take RHS as its LHS.
 507     int NextPrec = GetTokPrecedence();
 508     if (TokPrec < NextPrec) {
 509       RHS = ParseBinOpRHS(TokPrec+1, RHS);
 510       if (RHS == 0) return 0;
 511     }
 512
 513     // Merge LHS/RHS.
 514     LHS = new BinaryExprAST(BinOp, LHS, RHS);
 515   }
 516 }
 517
 518 /// expression
 519 ///   ::= unary binoprhs
 520 ///
 521 static ExprAST *ParseExpression() {
 522   ExprAST *LHS = ParseUnary();
 523   if (!LHS) return 0;
 524
 525   return ParseBinOpRHS(0, LHS);
 526 }
 527
 528 /// prototype
 529 ///   ::= id '(' id* ')'
 530 ///   ::= binary LETTER number? (id, id)
 531 ///   ::= unary LETTER (id)
 532 static PrototypeAST *ParsePrototype() {
 533   std::string FnName;
 534
 535   unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
 536   unsigned BinaryPrecedence = 30;
 537
 538   switch (CurTok) {
 539   default:
 540     return ErrorP("Expected function name in prototype");
 541   case tok_identifier:
 542     FnName = IdentifierStr;
 543     Kind = 0;
 544     getNextToken();
 545     break;
 546   case tok_unary:
 547     getNextToken();
 548     if (!isascii(CurTok))
 549       return ErrorP("Expected unary operator");
 550     FnName = "unary";
 551     FnName += (char)CurTok;
 552     Kind = 1;
 553     getNextToken();
 554     break;
 555   case tok_binary:
 556     getNextToken();
 557     if (!isascii(CurTok))
 558       return ErrorP("Expected binary operator");
 559     FnName = "binary";
 560     FnName += (char)CurTok;
 561     Kind = 2;
 562     getNextToken();
 563
 564     // Read the precedence if present.
 565     if (CurTok == tok_number) {
 566       if (NumVal < 1 || NumVal > 100)
 567         return ErrorP("Invalid precedecnce: must be 1..100");
 568       BinaryPrecedence = (unsigned)NumVal;
 569       getNextToken();
 570     }
 571     break;
 572   }
 573
 574   if (CurTok != '(')
 575     return ErrorP("Expected '(' in prototype");
 576
 577   std::vector<std::string> ArgNames;
 578   while (getNextToken() == tok_identifier)
 579     ArgNames.push_back(IdentifierStr);
 580   if (CurTok != ')')
 581     return ErrorP("Expected ')' in prototype");
 582
 583   // success.
 584   getNextToken();  // eat ')'.
 585
 586   // Verify right number of names for operator.
 587   if (Kind && ArgNames.size() != Kind)
 588     return ErrorP("Invalid number of operands for operator");
 589
 590   return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
 591 }
 592
 593 /// definition ::= 'def' prototype expression
 594 static FunctionAST *ParseDefinition() {
 595   getNextToken();  // eat def.
 596   PrototypeAST *Proto = ParsePrototype();
 597   if (Proto == 0) return 0;
 598
 599   if (ExprAST *E = ParseExpression())
 600     return new FunctionAST(Proto, E);
 601   return 0;
 602 }
 603
 604 /// toplevelexpr ::= expression
 605 static FunctionAST *ParseTopLevelExpr() {
 606   if (ExprAST *E = ParseExpression()) {
 607     // Make an anonymous proto.
 608     PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
 609     return new FunctionAST(Proto, E);
 610   }
 611   return 0;
 612 }
 613
 614 /// external ::= 'extern' prototype
 615 static PrototypeAST *ParseExtern() {
 616   getNextToken();  // eat extern.
 617   return ParsePrototype();
 618 }
 619
 620 //===----------------------------------------------------------------------===//
 621 // Code Generation
 622 //===----------------------------------------------------------------------===//
 623
 624 static Module *TheModule;
 625 static FunctionPassManager *TheFPM;
 626 static LLVMContext TheContext;
 627 static IRBuilder<> Builder(TheContext);
 628 static std::map<std::string, AllocaInst*> NamedValues;
 629
 630 Value *ErrorV(const char *Str) { Error(Str); return 0; }
 631
 632 /// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
 633 /// the function.  This is used for mutable variables etc.
 634 static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
 635                                           const std::string &VarName) {
 636   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
 637                  TheFunction->getEntryBlock().begin());
 638   return TmpB.CreateAlloca(Type::getDoubleTy(TheContext), 0, VarName.c_str());
 639 }
 640
 641 Value *NumberExprAST::Codegen() {
 642   return ConstantFP::get(TheContext, APFloat(Val));
 643 }
 644
 645 Value *VariableExprAST::Codegen() {
 646   // Look this variable up in the function.
 647   Value *V = NamedValues[Name];
 648   if (V == 0) return ErrorV("Unknown variable name");
 649
 650   // Load the value.
 651   return Builder.CreateLoad(V, Name.c_str());
 652 }
 653
 654 Value *UnaryExprAST::Codegen() {
 655   Value *OperandV = Operand->Codegen();
 656   if (OperandV == 0) return 0;
 657 #ifdef USE_MCJIT
 658   Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("unary")+Opcode));
 659 #else
 660   Function *F = TheModule->getFunction(std::string("unary")+Opcode);
 661 #endif
 662   if (F == 0)
 663     return ErrorV("Unknown unary operator");
 664
 665   return Builder.CreateCall(F, OperandV, "unop");
 666 }
 667
 668 Value *BinaryExprAST::Codegen() {
 669   // Special case '=' because we don't want to emit the LHS as an expression.
 670   if (Op == '=') {
 671     // Assignment requires the LHS to be an identifier.
 672     // For now, I'm building without RTTI because LLVM builds that way by
 673     // default and so we need to build that way to use the command line supprt.
 674     // If you build LLVM with RTTI this can be changed back to a dynamic_cast.
 675     VariableExprAST *LHSE = static_cast<VariableExprAST*>(LHS);
 676     if (!LHSE)
 677       return ErrorV("destination of '=' must be a variable");
 678     // Codegen the RHS.
 679     Value *Val = RHS->Codegen();
 680     if (Val == 0) return 0;
 681
 682     // Look up the name.
 683     Value *Variable = NamedValues[LHSE->getName()];
 684     if (Variable == 0) return ErrorV("Unknown variable name");
 685
 686     Builder.CreateStore(Val, Variable);
 687     return Val;
 688   }
 689
 690   Value *L = LHS->Codegen();
 691   Value *R = RHS->Codegen();
 692   if (L == 0 || R == 0) return 0;
 693
 694   switch (Op) {
 695   case '+': return Builder.CreateFAdd(L, R, "addtmp");
 696   case '-': return Builder.CreateFSub(L, R, "subtmp");
 697   case '*': return Builder.CreateFMul(L, R, "multmp");
 698   case '/': return Builder.CreateFDiv(L, R, "divtmp");
 699   case '<':
 700     L = Builder.CreateFCmpULT(L, R, "cmptmp");
 701     // Convert bool 0/1 to double 0.0 or 1.0
 702     return Builder.CreateUIToFP(L, Type::getDoubleTy(TheContext), "booltmp");
 703   default: break;
 704   }
 705
 706   // If it wasn't a builtin binary operator, it must be a user defined one. Emit
 707   // a call to it.
 708   Function *F = TheModule->getFunction(std::string("binary")+Op);
 709   assert(F && "binary operator not found!");
 710
 711   Value *Ops[] = { L, R };
 712   return Builder.CreateCall(F, Ops, "binop");
 713 }
 714
 715 Value *CallExprAST::Codegen() {
 716   // Look up the name in the global module table.
 717   Function *CalleeF = TheModule->getFunction(Callee);
 718   if (CalleeF == 0) {
 719     char error_str[64];
 720     sprintf(error_str, "Unknown function referenced %s", Callee.c_str());
 721     return ErrorV(error_str);
 722   }
 723
 724   // If argument mismatch error.
 725   if (CalleeF->arg_size() != Args.size())
 726     return ErrorV("Incorrect # arguments passed");
 727
 728   std::vector<Value*> ArgsV;
 729   for (unsigned i = 0, e = Args.size(); i != e; ++i) {
 730     ArgsV.push_back(Args[i]->Codegen());
 731     if (ArgsV.back() == 0) return 0;
 732   }
 733
 734   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 735 }
 736
 737 Value *IfExprAST::Codegen() {
 738   Value *CondV = Cond->Codegen();
 739   if (CondV == 0) return 0;
 740
 741   // Convert condition to a bool by comparing equal to 0.0.
 742   CondV = Builder.CreateFCmpONE(
 743       CondV, ConstantFP::get(TheContext, APFloat(0.0)), "ifcond");
 744
 745   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 746
 747   // Create blocks for the then and else cases.  Insert the 'then' block at the
 748   // end of the function.
 749   BasicBlock *ThenBB = BasicBlock::Create(TheContext, "then", TheFunction);
 750   BasicBlock *ElseBB = BasicBlock::Create(TheContext, "else");
 751   BasicBlock *MergeBB = BasicBlock::Create(TheContext, "ifcont");
 752
 753   Builder.CreateCondBr(CondV, ThenBB, ElseBB);
 754
 755   // Emit then value.
 756   Builder.SetInsertPoint(ThenBB);
 757
 758   Value *ThenV = Then->Codegen();
 759   if (ThenV == 0) return 0;
 760
 761   Builder.CreateBr(MergeBB);
 762   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
 763   ThenBB = Builder.GetInsertBlock();
 764
 765   // Emit else block.
 766   TheFunction->getBasicBlockList().push_back(ElseBB);
 767   Builder.SetInsertPoint(ElseBB);
 768
 769   Value *ElseV = Else->Codegen();
 770   if (ElseV == 0) return 0;
 771
 772   Builder.CreateBr(MergeBB);
 773   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
 774   ElseBB = Builder.GetInsertBlock();
 775
 776   // Emit merge block.
 777   TheFunction->getBasicBlockList().push_back(MergeBB);
 778   Builder.SetInsertPoint(MergeBB);
 779   PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(TheContext), 2, "iftmp");
 780
 781   PN->addIncoming(ThenV, ThenBB);
 782   PN->addIncoming(ElseV, ElseBB);
 783   return PN;
 784 }
 785
 786 Value *ForExprAST::Codegen() {
 787   // Output this as:
 788   //   var = alloca double
 789   //   ...
 790   //   start = startexpr
 791   //   store start -> var
 792   //   goto loop
 793   // loop:
 794   //   ...
 795   //   bodyexpr
 796   //   ...
 797   // loopend:
 798   //   step = stepexpr
 799   //   endcond = endexpr
 800   //
 801   //   curvar = load var
 802   //   nextvar = curvar + step
 803   //   store nextvar -> var
 804   //   br endcond, loop, endloop
 805   // outloop:
 806
 807   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 808
 809   // Create an alloca for the variable in the entry block.
 810   AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
 811
 812   // Emit the start code first, without 'variable' in scope.
 813   Value *StartVal = Start->Codegen();
 814   if (StartVal == 0) return 0;
 815
 816   // Store the value into the alloca.
 817   Builder.CreateStore(StartVal, Alloca);
 818
 819   // Make the new basic block for the loop header, inserting after current
 820   // block.
 821   BasicBlock *LoopBB = BasicBlock::Create(TheContext, "loop", TheFunction);
 822
 823   // Insert an explicit fall through from the current block to the LoopBB.
 824   Builder.CreateBr(LoopBB);
 825
 826   // Start insertion in LoopBB.
 827   Builder.SetInsertPoint(LoopBB);
 828
 829   // Within the loop, the variable is defined equal to the PHI node.  If it
 830   // shadows an existing variable, we have to restore it, so save it now.
 831   AllocaInst *OldVal = NamedValues[VarName];
 832   NamedValues[VarName] = Alloca;
 833
 834   // Emit the body of the loop.  This, like any other expr, can change the
 835   // current BB.  Note that we ignore the value computed by the body, but don't
 836   // allow an error.
 837   if (Body->Codegen() == 0)
 838     return 0;
 839
 840   // Emit the step value.
 841   Value *StepVal;
 842   if (Step) {
 843     StepVal = Step->Codegen();
 844     if (StepVal == 0) return 0;
 845   } else {
 846     // If not specified, use 1.0.
 847     StepVal = ConstantFP::get(TheContext, APFloat(1.0));
 848   }
 849
 850   // Compute the end condition.
 851   Value *EndCond = End->Codegen();
 852   if (EndCond == 0) return EndCond;
 853
 854   // Reload, increment, and restore the alloca.  This handles the case where
 855   // the body of the loop mutates the variable.
 856   Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
 857   Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
 858   Builder.CreateStore(NextVar, Alloca);
 859
 860   // Convert condition to a bool by comparing equal to 0.0.
 861   EndCond = Builder.CreateFCmpONE(
 862       EndCond, ConstantFP::get(TheContext, APFloat(0.0)), "loopcond");
 863
 864   // Create the "after loop" block and insert it.
 865   BasicBlock *AfterBB =
 866       BasicBlock::Create(TheContext, "afterloop", TheFunction);
 867
 868   // Insert the conditional branch into the end of LoopEndBB.
 869   Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
 870
 871   // Any new code will be inserted in AfterBB.
 872   Builder.SetInsertPoint(AfterBB);
 873
 874   // Restore the unshadowed variable.
 875   if (OldVal)
 876     NamedValues[VarName] = OldVal;
 877   else
 878     NamedValues.erase(VarName);
 879
 880
 881   // for expr always returns 0.0.
 882   return Constant::getNullValue(Type::getDoubleTy(TheContext));
 883 }
 884
 885 Value *VarExprAST::Codegen() {
 886   std::vector<AllocaInst *> OldBindings;
 887
 888   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 889
 890   // Register all variables and emit their initializer.
 891   for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
 892     const std::string &VarName = VarNames[i].first;
 893     ExprAST *Init = VarNames[i].second;
 894
 895     // Emit the initializer before adding the variable to scope, this prevents
 896     // the initializer from referencing the variable itself, and permits stuff
 897     // like this:
 898     //  var a = 1 in
 899     //    var a = a in ...   # refers to outer 'a'.
 900     Value *InitVal;
 901     if (Init) {
 902       InitVal = Init->Codegen();
 903       if (InitVal == 0) return 0;
 904     } else { // If not specified, use 0.0.
 905       InitVal = ConstantFP::get(TheContext, APFloat(0.0));
 906     }
 907
 908     AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
 909     Builder.CreateStore(InitVal, Alloca);
 910
 911     // Remember the old variable binding so that we can restore the binding when
 912     // we unrecurse.
 913     OldBindings.push_back(NamedValues[VarName]);
 914
 915     // Remember this binding.
 916     NamedValues[VarName] = Alloca;
 917   }
 918
 919   // Codegen the body, now that all vars are in scope.
 920   Value *BodyVal = Body->Codegen();
 921   if (BodyVal == 0) return 0;
 922
 923   // Pop all our variables from scope.
 924   for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
 925     NamedValues[VarNames[i].first] = OldBindings[i];
 926
 927   // Return the body computation.
 928   return BodyVal;
 929 }
 930
 931 Function *PrototypeAST::Codegen() {
 932   // Make the function type:  double(double,double) etc.
 933   std::vector<Type *> Doubles(Args.size(), Type::getDoubleTy(TheContext));
 934   FunctionType *FT =
 935       FunctionType::get(Type::getDoubleTy(TheContext), Doubles, false);
 936
 937   Function *F = Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
 938   // If F conflicted, there was already something named 'Name'.  If it has a
 939   // body, don't allow redefinition or reextern.
 940   if (F->getName() != Name) {
 941     // Delete the one we just made and get the existing one.
 942     F->eraseFromParent();
 943     F = TheModule->getFunction(Name);
 944     // If F already has a body, reject this.
 945     if (!F->empty()) {
 946       ErrorF("redefinition of function");
 947       return 0;
 948     }
 949     // If F took a different number of args, reject.
 950     if (F->arg_size() != Args.size()) {
 951       ErrorF("redefinition of function with different # args");
 952       return 0;
 953     }
 954   }
 955
 956   // Set names for all arguments.
 957   unsigned Idx = 0;
 958   for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
 959        ++AI, ++Idx)
 960     AI->setName(Args[Idx]);
 961
 962   return F;
 963 }
 964
 965 /// CreateArgumentAllocas - Create an alloca for each argument and register the
 966 /// argument in the symbol table so that references to it will succeed.
 967 void PrototypeAST::CreateArgumentAllocas(Function *F) {
 968   Function::arg_iterator AI = F->arg_begin();
 969   for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
 970     // Create an alloca for this variable.
 971     AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
 972
 973     // Store the initial value into the alloca.
 974     Builder.CreateStore(AI, Alloca);
 975
 976     // Add arguments to variable symbol table.
 977     NamedValues[Args[Idx]] = Alloca;
 978   }
 979 }
 980
 981 Function *FunctionAST::Codegen() {
 982   NamedValues.clear();
 983
 984   Function *TheFunction = Proto->Codegen();
 985   if (TheFunction == 0)
 986     return 0;
 987
 988   // If this is an operator, install it.
 989   if (Proto->isBinaryOp())
 990     BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
 991
 992   // Create a new basic block to start insertion into.
 993   BasicBlock *BB = BasicBlock::Create(TheContext, "entry", TheFunction);
 994   Builder.SetInsertPoint(BB);
 995
 996   // Add all arguments to the symbol table and create their allocas.
 997   Proto->CreateArgumentAllocas(TheFunction);
 998
 999   if (Value *RetVal = Body->Codegen()) {
1000     // Finish off the function.
1001     Builder.CreateRet(RetVal);
1002
1003     // Validate the generated code, checking for consistency.
1004     verifyFunction(*TheFunction);
1005
1006     // Optimize the function.
1007     TheFPM->run(*TheFunction);
1008
1009     return TheFunction;
1010   }
1011
1012   // Error reading body, remove function.
1013   TheFunction->eraseFromParent();
1014
1015   if (Proto->isBinaryOp())
1016     BinopPrecedence.erase(Proto->getOperatorName());
1017   return 0;
1018 }
1019
1020 //===----------------------------------------------------------------------===//
1021 // Top-Level parsing and JIT Driver
1022 //===----------------------------------------------------------------------===//
1023
1024 static ExecutionEngine *TheExecutionEngine;
1025
1026 static void HandleDefinition() {
1027   if (FunctionAST *F = ParseDefinition()) {
1028     if (Function *LF = F->Codegen()) {
1029 #ifndef MINIMAL_STDERR_OUTPUT
1030       fprintf(stderr, "Read function definition:");
1031       LF->dump();
1032 #endif
1033     }
1034   } else {
1035     // Skip token for error recovery.
1036     getNextToken();
1037   }
1038 }
1039
1040 static void HandleExtern() {
1041   if (PrototypeAST *P = ParseExtern()) {
1042     if (Function *F = P->Codegen()) {
1043 #ifndef MINIMAL_STDERR_OUTPUT
1044       fprintf(stderr, "Read extern: ");
1045       F->dump();
1046 #endif
1047     }
1048   } else {
1049     // Skip token for error recovery.
1050     getNextToken();
1051   }
1052 }
1053
1054 static void HandleTopLevelExpression() {
1055   // Evaluate a top-level expression into an anonymous function.
1056   if (FunctionAST *F = ParseTopLevelExpr()) {
1057     if (Function *LF = F->Codegen()) {
1058       // JIT the function, returning a function pointer.
1059       void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
1060       // Cast it to the right type (takes no arguments, returns a double) so we
1061       // can call it as a native function.
1062       double (*FP)() = (double (*)())(intptr_t)FPtr;
1063 #ifdef MINIMAL_STDERR_OUTPUT
1064       FP();
1065 #else
1066       fprintf(stderr, "Evaluated to %f\n", FP());
1067 #endif
1068     }
1069   } else {
1070     // Skip token for error recovery.
1071     getNextToken();
1072   }
1073 }
1074
1075 /// top ::= definition | external | expression | ';'
1076 static void MainLoop() {
1077   while (1) {
1078 #ifndef MINIMAL_STDERR_OUTPUT
1079     fprintf(stderr, "ready> ");
1080 #endif
1081     switch (CurTok) {
1082     case tok_eof:    return;
1083     case ';':        getNextToken(); break;  // ignore top-level semicolons.
1084     case tok_def:    HandleDefinition(); break;
1085     case tok_extern: HandleExtern(); break;
1086     default:         HandleTopLevelExpression(); break;
1087     }
1088   }
1089 }
1090
1091 //===----------------------------------------------------------------------===//
1092 // "Library" functions that can be "extern'd" from user code.
1093 //===----------------------------------------------------------------------===//
1094
1095 /// putchard - putchar that takes a double and returns 0.
1096 extern "C"
1097 double putchard(double X) {
1098   putchar((char)X);
1099   return 0;
1100 }
1101
1102 /// printd - printf that takes a double prints it as "%f\n", returning 0.
1103 extern "C"
1104 double printd(double X) {
1105   printf("%f", X);
1106   return 0;
1107 }
1108
1109 extern "C"
1110 double printlf() {
1111   printf("\n");
1112   return 0;
1113 }
1114
1115 //===----------------------------------------------------------------------===//
1116 // Command line input file handlers
1117 //===----------------------------------------------------------------------===//
1118
1119 Module* parseInputIR(std::string InputFile) {
1120   SMDiagnostic Err;
1121   Module *M = ParseIRFile(InputFile, Err, TheContext);
1122   if (!M) {
1123     Err.print("IR parsing failed: ", errs());
1124     return NULL;
1125   }
1126
1127   return M;
1128 }
1129
1130 //===----------------------------------------------------------------------===//
1131 // Main driver code.
1132 //===----------------------------------------------------------------------===//
1133
1134 int main(int argc, char **argv) {
1135   InitializeNativeTarget();
1136   LLVMContext &Context = TheContext;
1137
1138   cl::ParseCommandLineOptions(argc, argv,
1139                               "Kaleidoscope example program\n");
1140
1141   // Install standard binary operators.
1142   // 1 is lowest precedence.
1143   BinopPrecedence['='] = 2;
1144   BinopPrecedence['<'] = 10;
1145   BinopPrecedence['+'] = 20;
1146   BinopPrecedence['-'] = 20;
1147   BinopPrecedence['/'] = 40;
1148   BinopPrecedence['*'] = 40;  // highest.
1149
1150   // Make the module, which holds all the code.
1151   if (!InputIR.empty()) {
1152     TheModule = parseInputIR(InputIR);
1153   } else {
1154     TheModule = new Module("my cool jit", Context);
1155   }
1156
1157   // Create the JIT.  This takes ownership of the module.
1158   std::string ErrStr;
1159   TheExecutionEngine = EngineBuilder(TheModule).setErrorStr(&ErrStr).create();
1160   if (!TheExecutionEngine) {
1161     fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
1162     exit(1);
1163   }
1164
1165   FunctionPassManager OurFPM(TheModule);
1166
1167   // Set up the optimizer pipeline.  Start with registering info about how the
1168   // target lays out data structures.
1169   OurFPM.add(new DataLayout(*TheExecutionEngine->getDataLayout()));
1170   // Provide basic AliasAnalysis support for GVN.
1171   OurFPM.add(createBasicAliasAnalysisPass());
1172   // Promote allocas to registers.
1173   OurFPM.add(createPromoteMemoryToRegisterPass());
1174   // Do simple "peephole" optimizations and bit-twiddling optzns.
1175   OurFPM.add(createInstructionCombiningPass());
1176   // Reassociate expressions.
1177   OurFPM.add(createReassociatePass());
1178   // Eliminate Common SubExpressions.
1179   OurFPM.add(createGVNPass());
1180   // Simplify the control flow graph (deleting unreachable blocks, etc).
1181   OurFPM.add(createCFGSimplificationPass());
1182
1183   OurFPM.doInitialization();
1184
1185   // Set the global so the code gen can use this.
1186   TheFPM = &OurFPM;
1187
1188   // Prime the first token.
1189 #ifndef MINIMAL_STDERR_OUTPUT
1190   fprintf(stderr, "ready> ");
1191 #endif
1192   getNextToken();
1193
1194   // Run the main "interpreter loop" now.
1195   MainLoop();
1196
1197   // Print out all of the generated code.
1198   TheFPM = 0;
1199 #if !defined(MINIMAL_STDERR_OUTPUT) || defined(DUMP_FINAL_MODULE)
1200   TheModule->dump();
1201 #endif
1202   return 0;
1203 }