llvm/examples/Kaleidoscope/MCJIT/initial/toy.cpp

   1 #include "llvm/Analysis/Passes.h"
   2 #include "llvm/ExecutionEngine/ExecutionEngine.h"
   3 #include "llvm/ExecutionEngine/MCJIT.h"
   4 #include "llvm/ExecutionEngine/SectionMemoryManager.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/Support/TargetSelect.h"
  13 #include "llvm/Transforms/Scalar.h"
  14 #include <cctype>
  15 #include <cstdio>
  16 #include <map>
  17 #include <string>
  18 #include <vector>
  19 using namespace llvm;
  20
  21 //===----------------------------------------------------------------------===//
  22 // Lexer
  23 //===----------------------------------------------------------------------===//
  24
  25 // The lexer returns tokens [0-255] if it is an unknown character, otherwise one
  26 // of these for known things.
  27 enum Token {
  28   tok_eof = -1,
  29
  30   // commands
  31   tok_def = -2, tok_extern = -3,
  32
  33   // primary
  34   tok_identifier = -4, tok_number = -5,
  35
  36   // control
  37   tok_if = -6, tok_then = -7, tok_else = -8,
  38   tok_for = -9, tok_in = -10,
  39
  40   // operators
  41   tok_binary = -11, tok_unary = -12,
  42
  43   // var definition
  44   tok_var = -13
  45 };
  46
  47 static std::string IdentifierStr;  // Filled in if tok_identifier
  48 static double NumVal;              // Filled in if tok_number
  49
  50 /// gettok - Return the next token from standard input.
  51 static int gettok() {
  52   static int LastChar = ' ';
  53
  54   // Skip any whitespace.
  55   while (isspace(LastChar))
  56     LastChar = getchar();
  57
  58   if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
  59     IdentifierStr = LastChar;
  60     while (isalnum((LastChar = getchar())))
  61       IdentifierStr += LastChar;
  62
  63     if (IdentifierStr == "def") return tok_def;
  64     if (IdentifierStr == "extern") return tok_extern;
  65     if (IdentifierStr == "if") return tok_if;
  66     if (IdentifierStr == "then") return tok_then;
  67     if (IdentifierStr == "else") return tok_else;
  68     if (IdentifierStr == "for") return tok_for;
  69     if (IdentifierStr == "in") return tok_in;
  70     if (IdentifierStr == "binary") return tok_binary;
  71     if (IdentifierStr == "unary") return tok_unary;
  72     if (IdentifierStr == "var") return tok_var;
  73     return tok_identifier;
  74   }
  75
  76   if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
  77     std::string NumStr;
  78     do {
  79       NumStr += LastChar;
  80       LastChar = getchar();
  81     } while (isdigit(LastChar) || LastChar == '.');
  82
  83     NumVal = strtod(NumStr.c_str(), 0);
  84     return tok_number;
  85   }
  86
  87   if (LastChar == '#') {
  88     // Comment until end of line.
  89     do LastChar = getchar();
  90     while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
  91
  92     if (LastChar != EOF)
  93       return gettok();
  94   }
  95
  96   // Check for end of file.  Don't eat the EOF.
  97   if (LastChar == EOF)
  98     return tok_eof;
  99
 100   // Otherwise, just return the character as its ascii value.
 101   int ThisChar = LastChar;
 102   LastChar = getchar();
 103   return ThisChar;
 104 }
 105
 106 //===----------------------------------------------------------------------===//
 107 // Abstract Syntax Tree (aka Parse Tree)
 108 //===----------------------------------------------------------------------===//
 109
 110 /// ExprAST - Base class for all expression nodes.
 111 class ExprAST {
 112 public:
 113   virtual ~ExprAST() {}
 114   virtual Value *Codegen() = 0;
 115 };
 116
 117 /// NumberExprAST - Expression class for numeric literals like "1.0".
 118 class NumberExprAST : public ExprAST {
 119   double Val;
 120 public:
 121   NumberExprAST(double val) : Val(val) {}
 122   virtual Value *Codegen();
 123 };
 124
 125 /// VariableExprAST - Expression class for referencing a variable, like "a".
 126 class VariableExprAST : public ExprAST {
 127   std::string Name;
 128 public:
 129   VariableExprAST(const std::string &name) : Name(name) {}
 130   const std::string &getName() const { return Name; }
 131   virtual Value *Codegen();
 132 };
 133
 134 /// UnaryExprAST - Expression class for a unary operator.
 135 class UnaryExprAST : public ExprAST {
 136   char Opcode;
 137   ExprAST *Operand;
 138 public:
 139   UnaryExprAST(char opcode, ExprAST *operand)
 140     : Opcode(opcode), Operand(operand) {}
 141   virtual Value *Codegen();
 142 };
 143
 144 /// BinaryExprAST - Expression class for a binary operator.
 145 class BinaryExprAST : public ExprAST {
 146   char Op;
 147   ExprAST *LHS, *RHS;
 148 public:
 149   BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
 150     : Op(op), LHS(lhs), RHS(rhs) {}
 151   virtual Value *Codegen();
 152 };
 153
 154 /// CallExprAST - Expression class for function calls.
 155 class CallExprAST : public ExprAST {
 156   std::string Callee;
 157   std::vector<ExprAST*> Args;
 158 public:
 159   CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
 160     : Callee(callee), Args(args) {}
 161   virtual Value *Codegen();
 162 };
 163
 164 /// IfExprAST - Expression class for if/then/else.
 165 class IfExprAST : public ExprAST {
 166   ExprAST *Cond, *Then, *Else;
 167 public:
 168   IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
 169   : Cond(cond), Then(then), Else(_else) {}
 170   virtual Value *Codegen();
 171 };
 172
 173 /// ForExprAST - Expression class for for/in.
 174 class ForExprAST : public ExprAST {
 175   std::string VarName;
 176   ExprAST *Start, *End, *Step, *Body;
 177 public:
 178   ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
 179              ExprAST *step, ExprAST *body)
 180     : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
 181   virtual Value *Codegen();
 182 };
 183
 184 /// VarExprAST - Expression class for var/in
 185 class VarExprAST : public ExprAST {
 186   std::vector<std::pair<std::string, ExprAST*> > VarNames;
 187   ExprAST *Body;
 188 public:
 189   VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
 190              ExprAST *body)
 191   : VarNames(varnames), Body(body) {}
 192
 193   virtual Value *Codegen();
 194 };
 195
 196 /// PrototypeAST - This class represents the "prototype" for a function,
 197 /// which captures its argument names as well as if it is an operator.
 198 class PrototypeAST {
 199   std::string Name;
 200   std::vector<std::string> Args;
 201   bool isOperator;
 202   unsigned Precedence;  // Precedence if a binary op.
 203 public:
 204   PrototypeAST(const std::string &name, const std::vector<std::string> &args,
 205                bool isoperator = false, unsigned prec = 0)
 206   : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
 207
 208   bool isUnaryOp() const { return isOperator && Args.size() == 1; }
 209   bool isBinaryOp() const { return isOperator && Args.size() == 2; }
 210
 211   char getOperatorName() const {
 212     assert(isUnaryOp() || isBinaryOp());
 213     return Name[Name.size()-1];
 214   }
 215
 216   unsigned getBinaryPrecedence() const { return Precedence; }
 217
 218   Function *Codegen();
 219
 220   void CreateArgumentAllocas(Function *F);
 221 };
 222
 223 /// FunctionAST - This class represents a function definition itself.
 224 class FunctionAST {
 225   PrototypeAST *Proto;
 226   ExprAST *Body;
 227 public:
 228   FunctionAST(PrototypeAST *proto, ExprAST *body)
 229     : Proto(proto), Body(body) {}
 230
 231   Function *Codegen();
 232 };
 233
 234 //===----------------------------------------------------------------------===//
 235 // Parser
 236 //===----------------------------------------------------------------------===//
 237
 238 /// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
 239 /// token the parser is looking at.  getNextToken reads another token from the
 240 /// lexer and updates CurTok with its results.
 241 static int CurTok;
 242 static int getNextToken() {
 243   return CurTok = gettok();
 244 }
 245
 246 /// BinopPrecedence - This holds the precedence for each binary operator that is
 247 /// defined.
 248 static std::map<char, int> BinopPrecedence;
 249
 250 /// GetTokPrecedence - Get the precedence of the pending binary operator token.
 251 static int GetTokPrecedence() {
 252   if (!isascii(CurTok))
 253     return -1;
 254
 255   // Make sure it's a declared binop.
 256   int TokPrec = BinopPrecedence[CurTok];
 257   if (TokPrec <= 0) return -1;
 258   return TokPrec;
 259 }
 260
 261 /// Error* - These are little helper functions for error handling.
 262 ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
 263 PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
 264 FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
 265
 266 static ExprAST *ParseExpression();
 267
 268 /// identifierexpr
 269 ///   ::= identifier
 270 ///   ::= identifier '(' expression* ')'
 271 static ExprAST *ParseIdentifierExpr() {
 272   std::string IdName = IdentifierStr;
 273
 274   getNextToken();  // eat identifier.
 275
 276   if (CurTok != '(') // Simple variable ref.
 277     return new VariableExprAST(IdName);
 278
 279   // Call.
 280   getNextToken();  // eat (
 281   std::vector<ExprAST*> Args;
 282   if (CurTok != ')') {
 283     while (1) {
 284       ExprAST *Arg = ParseExpression();
 285       if (!Arg) return 0;
 286       Args.push_back(Arg);
 287
 288       if (CurTok == ')') break;
 289
 290       if (CurTok != ',')
 291         return Error("Expected ')' or ',' in argument list");
 292       getNextToken();
 293     }
 294   }
 295
 296   // Eat the ')'.
 297   getNextToken();
 298
 299   return new CallExprAST(IdName, Args);
 300 }
 301
 302 /// numberexpr ::= number
 303 static ExprAST *ParseNumberExpr() {
 304   ExprAST *Result = new NumberExprAST(NumVal);
 305   getNextToken(); // consume the number
 306   return Result;
 307 }
 308
 309 /// parenexpr ::= '(' expression ')'
 310 static ExprAST *ParseParenExpr() {
 311   getNextToken();  // eat (.
 312   ExprAST *V = ParseExpression();
 313   if (!V) return 0;
 314
 315   if (CurTok != ')')
 316     return Error("expected ')'");
 317   getNextToken();  // eat ).
 318   return V;
 319 }
 320
 321 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
 322 static ExprAST *ParseIfExpr() {
 323   getNextToken();  // eat the if.
 324
 325   // condition.
 326   ExprAST *Cond = ParseExpression();
 327   if (!Cond) return 0;
 328
 329   if (CurTok != tok_then)
 330     return Error("expected then");
 331   getNextToken();  // eat the then
 332
 333   ExprAST *Then = ParseExpression();
 334   if (Then == 0) return 0;
 335
 336   if (CurTok != tok_else)
 337     return Error("expected else");
 338
 339   getNextToken();
 340
 341   ExprAST *Else = ParseExpression();
 342   if (!Else) return 0;
 343
 344   return new IfExprAST(Cond, Then, Else);
 345 }
 346
 347 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
 348 static ExprAST *ParseForExpr() {
 349   getNextToken();  // eat the for.
 350
 351   if (CurTok != tok_identifier)
 352     return Error("expected identifier after for");
 353
 354   std::string IdName = IdentifierStr;
 355   getNextToken();  // eat identifier.
 356
 357   if (CurTok != '=')
 358     return Error("expected '=' after for");
 359   getNextToken();  // eat '='.
 360
 361
 362   ExprAST *Start = ParseExpression();
 363   if (Start == 0) return 0;
 364   if (CurTok != ',')
 365     return Error("expected ',' after for start value");
 366   getNextToken();
 367
 368   ExprAST *End = ParseExpression();
 369   if (End == 0) return 0;
 370
 371   // The step value is optional.
 372   ExprAST *Step = 0;
 373   if (CurTok == ',') {
 374     getNextToken();
 375     Step = ParseExpression();
 376     if (Step == 0) return 0;
 377   }
 378
 379   if (CurTok != tok_in)
 380     return Error("expected 'in' after for");
 381   getNextToken();  // eat 'in'.
 382
 383   ExprAST *Body = ParseExpression();
 384   if (Body == 0) return 0;
 385
 386   return new ForExprAST(IdName, Start, End, Step, Body);
 387 }
 388
 389 /// varexpr ::= 'var' identifier ('=' expression)?
 390 //                    (',' identifier ('=' expression)?)* 'in' expression
 391 static ExprAST *ParseVarExpr() {
 392   getNextToken();  // eat the var.
 393
 394   std::vector<std::pair<std::string, ExprAST*> > VarNames;
 395
 396   // At least one variable name is required.
 397   if (CurTok != tok_identifier)
 398     return Error("expected identifier after var");
 399
 400   while (1) {
 401     std::string Name = IdentifierStr;
 402     getNextToken();  // eat identifier.
 403
 404     // Read the optional initializer.
 405     ExprAST *Init = 0;
 406     if (CurTok == '=') {
 407       getNextToken(); // eat the '='.
 408
 409       Init = ParseExpression();
 410       if (Init == 0) return 0;
 411     }
 412
 413     VarNames.push_back(std::make_pair(Name, Init));
 414
 415     // End of var list, exit loop.
 416     if (CurTok != ',') break;
 417     getNextToken(); // eat the ','.
 418
 419     if (CurTok != tok_identifier)
 420       return Error("expected identifier list after var");
 421   }
 422
 423   // At this point, we have to have 'in'.
 424   if (CurTok != tok_in)
 425     return Error("expected 'in' keyword after 'var'");
 426   getNextToken();  // eat 'in'.
 427
 428   ExprAST *Body = ParseExpression();
 429   if (Body == 0) return 0;
 430
 431   return new VarExprAST(VarNames, Body);
 432 }
 433
 434 /// primary
 435 ///   ::= identifierexpr
 436 ///   ::= numberexpr
 437 ///   ::= parenexpr
 438 ///   ::= ifexpr
 439 ///   ::= forexpr
 440 ///   ::= varexpr
 441 static ExprAST *ParsePrimary() {
 442   switch (CurTok) {
 443   default: return Error("unknown token when expecting an expression");
 444   case tok_identifier: return ParseIdentifierExpr();
 445   case tok_number:     return ParseNumberExpr();
 446   case '(':            return ParseParenExpr();
 447   case tok_if:         return ParseIfExpr();
 448   case tok_for:        return ParseForExpr();
 449   case tok_var:        return ParseVarExpr();
 450   }
 451 }
 452
 453 /// unary
 454 ///   ::= primary
 455 ///   ::= '!' unary
 456 static ExprAST *ParseUnary() {
 457   // If the current token is not an operator, it must be a primary expr.
 458   if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
 459     return ParsePrimary();
 460
 461   // If this is a unary operator, read it.
 462   int Opc = CurTok;
 463   getNextToken();
 464   if (ExprAST *Operand = ParseUnary())
 465     return new UnaryExprAST(Opc, Operand);
 466   return 0;
 467 }
 468
 469 /// binoprhs
 470 ///   ::= ('+' unary)*
 471 static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
 472   // If this is a binop, find its precedence.
 473   while (1) {
 474     int TokPrec = GetTokPrecedence();
 475
 476     // If this is a binop that binds at least as tightly as the current binop,
 477     // consume it, otherwise we are done.
 478     if (TokPrec < ExprPrec)
 479       return LHS;
 480
 481     // Okay, we know this is a binop.
 482     int BinOp = CurTok;
 483     getNextToken();  // eat binop
 484
 485     // Parse the unary expression after the binary operator.
 486     ExprAST *RHS = ParseUnary();
 487     if (!RHS) return 0;
 488
 489     // If BinOp binds less tightly with RHS than the operator after RHS, let
 490     // the pending operator take RHS as its LHS.
 491     int NextPrec = GetTokPrecedence();
 492     if (TokPrec < NextPrec) {
 493       RHS = ParseBinOpRHS(TokPrec+1, RHS);
 494       if (RHS == 0) return 0;
 495     }
 496
 497     // Merge LHS/RHS.
 498     LHS = new BinaryExprAST(BinOp, LHS, RHS);
 499   }
 500 }
 501
 502 /// expression
 503 ///   ::= unary binoprhs
 504 ///
 505 static ExprAST *ParseExpression() {
 506   ExprAST *LHS = ParseUnary();
 507   if (!LHS) return 0;
 508
 509   return ParseBinOpRHS(0, LHS);
 510 }
 511
 512 /// prototype
 513 ///   ::= id '(' id* ')'
 514 ///   ::= binary LETTER number? (id, id)
 515 ///   ::= unary LETTER (id)
 516 static PrototypeAST *ParsePrototype() {
 517   std::string FnName;
 518
 519   unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
 520   unsigned BinaryPrecedence = 30;
 521
 522   switch (CurTok) {
 523   default:
 524     return ErrorP("Expected function name in prototype");
 525   case tok_identifier:
 526     FnName = IdentifierStr;
 527     Kind = 0;
 528     getNextToken();
 529     break;
 530   case tok_unary:
 531     getNextToken();
 532     if (!isascii(CurTok))
 533       return ErrorP("Expected unary operator");
 534     FnName = "unary";
 535     FnName += (char)CurTok;
 536     Kind = 1;
 537     getNextToken();
 538     break;
 539   case tok_binary:
 540     getNextToken();
 541     if (!isascii(CurTok))
 542       return ErrorP("Expected binary operator");
 543     FnName = "binary";
 544     FnName += (char)CurTok;
 545     Kind = 2;
 546     getNextToken();
 547
 548     // Read the precedence if present.
 549     if (CurTok == tok_number) {
 550       if (NumVal < 1 || NumVal > 100)
 551         return ErrorP("Invalid precedecnce: must be 1..100");
 552       BinaryPrecedence = (unsigned)NumVal;
 553       getNextToken();
 554     }
 555     break;
 556   }
 557
 558   if (CurTok != '(')
 559     return ErrorP("Expected '(' in prototype");
 560
 561   std::vector<std::string> ArgNames;
 562   while (getNextToken() == tok_identifier)
 563     ArgNames.push_back(IdentifierStr);
 564   if (CurTok != ')')
 565     return ErrorP("Expected ')' in prototype");
 566
 567   // success.
 568   getNextToken();  // eat ')'.
 569
 570   // Verify right number of names for operator.
 571   if (Kind && ArgNames.size() != Kind)
 572     return ErrorP("Invalid number of operands for operator");
 573
 574   return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
 575 }
 576
 577 /// definition ::= 'def' prototype expression
 578 static FunctionAST *ParseDefinition() {
 579   getNextToken();  // eat def.
 580   PrototypeAST *Proto = ParsePrototype();
 581   if (Proto == 0) return 0;
 582
 583   if (ExprAST *E = ParseExpression())
 584     return new FunctionAST(Proto, E);
 585   return 0;
 586 }
 587
 588 /// toplevelexpr ::= expression
 589 static FunctionAST *ParseTopLevelExpr() {
 590   if (ExprAST *E = ParseExpression()) {
 591     // Make an anonymous proto.
 592     PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
 593     return new FunctionAST(Proto, E);
 594   }
 595   return 0;
 596 }
 597
 598 /// external ::= 'extern' prototype
 599 static PrototypeAST *ParseExtern() {
 600   getNextToken();  // eat extern.
 601   return ParsePrototype();
 602 }
 603
 604 //===----------------------------------------------------------------------===//
 605 // Quick and dirty hack
 606 //===----------------------------------------------------------------------===//
 607
 608 // FIXME: Obviously we can do better than this
 609 std::string GenerateUniqueName(const char *root)
 610 {
 611   static int i = 0;
 612   char s[16];
 613   sprintf(s, "%s%d", root, i++);
 614   std::string S = s;
 615   return S;
 616 }
 617
 618 std::string MakeLegalFunctionName(std::string Name)
 619 {
 620   std::string NewName;
 621   if (!Name.length())
 622       return GenerateUniqueName("anon_func_");
 623
 624   // Start with what we have
 625   NewName = Name;
 626
 627   // Look for a numberic first character
 628   if (NewName.find_first_of("0123456789") == 0) {
 629     NewName.insert(0, 1, 'n');
 630   }
 631
 632   // Replace illegal characters with their ASCII equivalent
 633   std::string legal_elements = "_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
 634   size_t pos;
 635   while ((pos = NewName.find_first_not_of(legal_elements)) != std::string::npos) {
 636     char old_c = NewName.at(pos);
 637     char new_str[16];
 638     sprintf(new_str, "%d", (int)old_c);
 639     NewName = NewName.replace(pos, 1, new_str);
 640   }
 641
 642   return NewName;
 643 }
 644
 645 //===----------------------------------------------------------------------===//
 646 // MCJIT helper class
 647 //===----------------------------------------------------------------------===//
 648
 649 class MCJITHelper
 650 {
 651 public:
 652   MCJITHelper(LLVMContext& C) : Context(C), OpenModule(NULL) {}
 653   ~MCJITHelper();
 654
 655   Function *getFunction(const std::string FnName);
 656   Module *getModuleForNewFunction();
 657   void *getPointerToFunction(Function* F);
 658   void *getPointerToNamedFunction(const std::string &Name);
 659   void dump();
 660
 661 private:
 662   typedef std::vector<Module*> ModuleVector;
 663   typedef std::vector<ExecutionEngine*> EngineVector;
 664
 665   LLVMContext  &Context;
 666   Module       *OpenModule;
 667   ModuleVector  Modules;
 668   EngineVector  Engines;
 669 };
 670
 671 class HelpingMemoryManager : public SectionMemoryManager
 672 {
 673   HelpingMemoryManager(const HelpingMemoryManager&) = delete;
 674   void operator=(const HelpingMemoryManager&) = delete;
 675
 676 public:
 677   HelpingMemoryManager(MCJITHelper *Helper) : MasterHelper(Helper) {}
 678   virtual ~HelpingMemoryManager() {}
 679
 680   /// This method returns the address of the specified function.
 681   /// Our implementation will attempt to find functions in other
 682   /// modules associated with the MCJITHelper to cross link functions
 683   /// from one generated module to another.
 684   ///
 685   /// If \p AbortOnFailure is false and no function with the given name is
 686   /// found, this function returns a null pointer. Otherwise, it prints a
 687   /// message to stderr and aborts.
 688   virtual void *getPointerToNamedFunction(const std::string &Name,
 689                                           bool AbortOnFailure = true);
 690 private:
 691   MCJITHelper *MasterHelper;
 692 };
 693
 694 void *HelpingMemoryManager::getPointerToNamedFunction(const std::string &Name,
 695                                         bool AbortOnFailure)
 696 {
 697   // Try the standard symbol resolution first, but ask it not to abort.
 698   void *pfn = SectionMemoryManager::getPointerToNamedFunction(Name, false);
 699   if (pfn)
 700     return pfn;
 701
 702   pfn = MasterHelper->getPointerToNamedFunction(Name);
 703   if (!pfn && AbortOnFailure)
 704     report_fatal_error("Program used external function '" + Name +
 705                         "' which could not be resolved!");
 706   return pfn;
 707 }
 708
 709 MCJITHelper::~MCJITHelper()
 710 {
 711   if (OpenModule)
 712     delete OpenModule;
 713   EngineVector::iterator begin = Engines.begin();
 714   EngineVector::iterator end = Engines.end();
 715   EngineVector::iterator it;
 716   for (it = begin; it != end; ++it)
 717     delete *it;
 718 }
 719
 720 Function *MCJITHelper::getFunction(const std::string FnName) {
 721   ModuleVector::iterator begin = Modules.begin();
 722   ModuleVector::iterator end = Modules.end();
 723   ModuleVector::iterator it;
 724   for (it = begin; it != end; ++it) {
 725     Function *F = (*it)->getFunction(FnName);
 726     if (F) {
 727       if (*it == OpenModule)
 728           return F;
 729
 730       assert(OpenModule != NULL);
 731
 732       // This function is in a module that has already been JITed.
 733       // We need to generate a new prototype for external linkage.
 734       Function *PF = OpenModule->getFunction(FnName);
 735       if (PF && !PF->empty()) {
 736         ErrorF("redefinition of function across modules");
 737         return 0;
 738       }
 739
 740       // If we don't have a prototype yet, create one.
 741       if (!PF)
 742         PF = Function::Create(F->getFunctionType(),
 743                                       Function::ExternalLinkage,
 744                                       FnName,
 745                                       OpenModule);
 746       return PF;
 747     }
 748   }
 749   return NULL;
 750 }
 751
 752 Module *MCJITHelper::getModuleForNewFunction() {
 753   // If we have a Module that hasn't been JITed, use that.
 754   if (OpenModule)
 755     return OpenModule;
 756
 757   // Otherwise create a new Module.
 758   std::string ModName = GenerateUniqueName("mcjit_module_");
 759   Module *M = new Module(ModName, Context);
 760   Modules.push_back(M);
 761   OpenModule = M;
 762   return M;
 763 }
 764
 765 void *MCJITHelper::getPointerToFunction(Function* F) {
 766   // See if an existing instance of MCJIT has this function.
 767   EngineVector::iterator begin = Engines.begin();
 768   EngineVector::iterator end = Engines.end();
 769   EngineVector::iterator it;
 770   for (it = begin; it != end; ++it) {
 771     void *P = (*it)->getPointerToFunction(F);
 772     if (P)
 773       return P;
 774   }
 775
 776   // If we didn't find the function, see if we can generate it.
 777   if (OpenModule) {
 778     std::string ErrStr;
 779     ExecutionEngine *NewEngine = EngineBuilder(OpenModule)
 780                                               .setErrorStr(&ErrStr)
 781                                               .setMCJITMemoryManager(new HelpingMemoryManager(this))
 782                                               .create();
 783     if (!NewEngine) {
 784       fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
 785       exit(1);
 786     }
 787
 788     // Create a function pass manager for this engine
 789     FunctionPassManager *FPM = new FunctionPassManager(OpenModule);
 790
 791     // Set up the optimizer pipeline.  Start with registering info about how the
 792     // target lays out data structures.
 793     FPM->add(new DataLayout(*NewEngine->getDataLayout()));
 794     // Provide basic AliasAnalysis support for GVN.
 795     FPM->add(createBasicAliasAnalysisPass());
 796     // Promote allocas to registers.
 797     FPM->add(createPromoteMemoryToRegisterPass());
 798     // Do simple "peephole" optimizations and bit-twiddling optzns.
 799     FPM->add(createInstructionCombiningPass());
 800     // Reassociate expressions.
 801     FPM->add(createReassociatePass());
 802     // Eliminate Common SubExpressions.
 803     FPM->add(createGVNPass());
 804     // Simplify the control flow graph (deleting unreachable blocks, etc).
 805     FPM->add(createCFGSimplificationPass());
 806     FPM->doInitialization();
 807
 808     // For each function in the module
 809     Module::iterator it;
 810     Module::iterator end = OpenModule->end();
 811     for (it = OpenModule->begin(); it != end; ++it) {
 812       // Run the FPM on this function
 813       FPM->run(*it);
 814     }
 815
 816     // We don't need this anymore
 817     delete FPM;
 818
 819     OpenModule = NULL;
 820     Engines.push_back(NewEngine);
 821     NewEngine->finalizeObject();
 822     return NewEngine->getPointerToFunction(F);
 823   }
 824   return NULL;
 825 }
 826
 827 void *MCJITHelper::getPointerToNamedFunction(const std::string &Name)
 828 {
 829   // Look for the function in each of our execution engines.
 830   EngineVector::iterator begin = Engines.begin();
 831   EngineVector::iterator end = Engines.end();
 832   EngineVector::iterator it;
 833   for (it = begin; it != end; ++it) {
 834     if (Function *F = (*it)->FindFunctionNamed(Name.c_str()))
 835         return (*it)->getPointerToFunction(F);
 836   }
 837
 838   return NULL;
 839 }
 840
 841 void MCJITHelper::dump()
 842 {
 843   ModuleVector::iterator begin = Modules.begin();
 844   ModuleVector::iterator end = Modules.end();
 845   ModuleVector::iterator it;
 846   for (it = begin; it != end; ++it)
 847     (*it)->dump();
 848 }
 849
 850 //===----------------------------------------------------------------------===//
 851 // Code Generation
 852 //===----------------------------------------------------------------------===//
 853
 854 static MCJITHelper *TheHelper;
 855 static LLVMContext TheContext;
 856 static IRBuilder<> Builder(TheContext);
 857 static std::map<std::string, AllocaInst*> NamedValues;
 858
 859 Value *ErrorV(const char *Str) { Error(Str); return 0; }
 860
 861 /// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
 862 /// the function.  This is used for mutable variables etc.
 863 static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
 864                                           const std::string &VarName) {
 865   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
 866                  TheFunction->getEntryBlock().begin());
 867   return TmpB.CreateAlloca(Type::getDoubleTy(TheContext), 0, VarName.c_str());
 868 }
 869
 870 Value *NumberExprAST::Codegen() {
 871   return ConstantFP::get(TheContext, APFloat(Val));
 872 }
 873
 874 Value *VariableExprAST::Codegen() {
 875   // Look this variable up in the function.
 876   Value *V = NamedValues[Name];
 877   char ErrStr[256];
 878   sprintf(ErrStr, "Unknown variable name %s", Name.c_str());
 879   if (V == 0) return ErrorV(ErrStr);
 880
 881   // Load the value.
 882   return Builder.CreateLoad(V, Name.c_str());
 883 }
 884
 885 Value *UnaryExprAST::Codegen() {
 886   Value *OperandV = Operand->Codegen();
 887   if (OperandV == 0) return 0;
 888
 889   Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("unary")+Opcode));
 890   if (F == 0)
 891     return ErrorV("Unknown unary operator");
 892
 893   return Builder.CreateCall(F, OperandV, "unop");
 894 }
 895
 896 Value *BinaryExprAST::Codegen() {
 897   // Special case '=' because we don't want to emit the LHS as an expression.
 898   if (Op == '=') {
 899     // Assignment requires the LHS to be an identifier.
 900     VariableExprAST *LHSE = static_cast<VariableExprAST*>(LHS);
 901     if (!LHSE)
 902       return ErrorV("destination of '=' must be a variable");
 903     // Codegen the RHS.
 904     Value *Val = RHS->Codegen();
 905     if (Val == 0) return 0;
 906
 907     // Look up the name.
 908     Value *Variable = NamedValues[LHSE->getName()];
 909     if (Variable == 0) return ErrorV("Unknown variable name");
 910
 911     Builder.CreateStore(Val, Variable);
 912     return Val;
 913   }
 914
 915   Value *L = LHS->Codegen();
 916   Value *R = RHS->Codegen();
 917   if (L == 0 || R == 0) return 0;
 918
 919   switch (Op) {
 920   case '+': return Builder.CreateFAdd(L, R, "addtmp");
 921   case '-': return Builder.CreateFSub(L, R, "subtmp");
 922   case '*': return Builder.CreateFMul(L, R, "multmp");
 923   case '/': return Builder.CreateFDiv(L, R, "divtmp");
 924   case '<':
 925     L = Builder.CreateFCmpULT(L, R, "cmptmp");
 926     // Convert bool 0/1 to double 0.0 or 1.0
 927     return Builder.CreateUIToFP(L, Type::getDoubleTy(TheContext), "booltmp");
 928   default: break;
 929   }
 930
 931   // If it wasn't a builtin binary operator, it must be a user defined one. Emit
 932   // a call to it.
 933   Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("binary")+Op));
 934   assert(F && "binary operator not found!");
 935
 936   Value *Ops[] = { L, R };
 937   return Builder.CreateCall(F, Ops, "binop");
 938 }
 939
 940 Value *CallExprAST::Codegen() {
 941   // Look up the name in the global module table.
 942   Function *CalleeF = TheHelper->getFunction(Callee);
 943   if (CalleeF == 0)
 944     return ErrorV("Unknown function referenced");
 945
 946   // If argument mismatch error.
 947   if (CalleeF->arg_size() != Args.size())
 948     return ErrorV("Incorrect # arguments passed");
 949
 950   std::vector<Value*> ArgsV;
 951   for (unsigned i = 0, e = Args.size(); i != e; ++i) {
 952     ArgsV.push_back(Args[i]->Codegen());
 953     if (ArgsV.back() == 0) return 0;
 954   }
 955
 956   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
 957 }
 958
 959 Value *IfExprAST::Codegen() {
 960   Value *CondV = Cond->Codegen();
 961   if (CondV == 0) return 0;
 962
 963   // Convert condition to a bool by comparing equal to 0.0.
 964   CondV = Builder.CreateFCmpONE(
 965       CondV, ConstantFP::get(TheContext, APFloat(0.0)), "ifcond");
 966
 967   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 968
 969   // Create blocks for the then and else cases.  Insert the 'then' block at the
 970   // end of the function.
 971   BasicBlock *ThenBB = BasicBlock::Create(TheContext, "then", TheFunction);
 972   BasicBlock *ElseBB = BasicBlock::Create(TheContext, "else");
 973   BasicBlock *MergeBB = BasicBlock::Create(TheContext, "ifcont");
 974
 975   Builder.CreateCondBr(CondV, ThenBB, ElseBB);
 976
 977   // Emit then value.
 978   Builder.SetInsertPoint(ThenBB);
 979
 980   Value *ThenV = Then->Codegen();
 981   if (ThenV == 0) return 0;
 982
 983   Builder.CreateBr(MergeBB);
 984   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
 985   ThenBB = Builder.GetInsertBlock();
 986
 987   // Emit else block.
 988   TheFunction->insert(TheFunction->end(), ElseBB);
 989   Builder.SetInsertPoint(ElseBB);
 990
 991   Value *ElseV = Else->Codegen();
 992   if (ElseV == 0) return 0;
 993
 994   Builder.CreateBr(MergeBB);
 995   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
 996   ElseBB = Builder.GetInsertBlock();
 997
 998   // Emit merge block.
 999   TheFunction->insert(TheFunction->end(), MergeBB);
1000   Builder.SetInsertPoint(MergeBB);
1001   PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(TheContext), 2, "iftmp");
1002
1003   PN->addIncoming(ThenV, ThenBB);
1004   PN->addIncoming(ElseV, ElseBB);
1005   return PN;
1006 }
1007
1008 Value *ForExprAST::Codegen() {
1009   // Output this as:
1010   //   var = alloca double
1011   //   ...
1012   //   start = startexpr
1013   //   store start -> var
1014   //   goto loop
1015   // loop:
1016   //   ...
1017   //   bodyexpr
1018   //   ...
1019   // loopend:
1020   //   step = stepexpr
1021   //   endcond = endexpr
1022   //
1023   //   curvar = load var
1024   //   nextvar = curvar + step
1025   //   store nextvar -> var
1026   //   br endcond, loop, endloop
1027   // outloop:
1028
1029   Function *TheFunction = Builder.GetInsertBlock()->getParent();
1030
1031   // Create an alloca for the variable in the entry block.
1032   AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
1033
1034   // Emit the start code first, without 'variable' in scope.
1035   Value *StartVal = Start->Codegen();
1036   if (StartVal == 0) return 0;
1037
1038   // Store the value into the alloca.
1039   Builder.CreateStore(StartVal, Alloca);
1040
1041   // Make the new basic block for the loop header, inserting after current
1042   // block.
1043   BasicBlock *LoopBB = BasicBlock::Create(TheContext, "loop", TheFunction);
1044
1045   // Insert an explicit fall through from the current block to the LoopBB.
1046   Builder.CreateBr(LoopBB);
1047
1048   // Start insertion in LoopBB.
1049   Builder.SetInsertPoint(LoopBB);
1050
1051   // Within the loop, the variable is defined equal to the PHI node.  If it
1052   // shadows an existing variable, we have to restore it, so save it now.
1053   AllocaInst *OldVal = NamedValues[VarName];
1054   NamedValues[VarName] = Alloca;
1055
1056   // Emit the body of the loop.  This, like any other expr, can change the
1057   // current BB.  Note that we ignore the value computed by the body, but don't
1058   // allow an error.
1059   if (Body->Codegen() == 0)
1060     return 0;
1061
1062   // Emit the step value.
1063   Value *StepVal;
1064   if (Step) {
1065     StepVal = Step->Codegen();
1066     if (StepVal == 0) return 0;
1067   } else {
1068     // If not specified, use 1.0.
1069     StepVal = ConstantFP::get(TheContext, APFloat(1.0));
1070   }
1071
1072   // Compute the end condition.
1073   Value *EndCond = End->Codegen();
1074   if (EndCond == 0) return EndCond;
1075
1076   // Reload, increment, and restore the alloca.  This handles the case where
1077   // the body of the loop mutates the variable.
1078   Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
1079   Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
1080   Builder.CreateStore(NextVar, Alloca);
1081
1082   // Convert condition to a bool by comparing equal to 0.0.
1083   EndCond = Builder.CreateFCmpONE(
1084       EndCond, ConstantFP::get(TheContext, APFloat(0.0)), "loopcond");
1085
1086   // Create the "after loop" block and insert it.
1087   BasicBlock *AfterBB =
1088       BasicBlock::Create(TheContext, "afterloop", TheFunction);
1089
1090   // Insert the conditional branch into the end of LoopEndBB.
1091   Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
1092
1093   // Any new code will be inserted in AfterBB.
1094   Builder.SetInsertPoint(AfterBB);
1095
1096   // Restore the unshadowed variable.
1097   if (OldVal)
1098     NamedValues[VarName] = OldVal;
1099   else
1100     NamedValues.erase(VarName);
1101
1102
1103   // for expr always returns 0.0.
1104   return Constant::getNullValue(Type::getDoubleTy(TheContext));
1105 }
1106
1107 Value *VarExprAST::Codegen() {
1108   std::vector<AllocaInst *> OldBindings;
1109
1110   Function *TheFunction = Builder.GetInsertBlock()->getParent();
1111
1112   // Register all variables and emit their initializer.
1113   for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
1114     const std::string &VarName = VarNames[i].first;
1115     ExprAST *Init = VarNames[i].second;
1116
1117     // Emit the initializer before adding the variable to scope, this prevents
1118     // the initializer from referencing the variable itself, and permits stuff
1119     // like this:
1120     //  var a = 1 in
1121     //    var a = a in ...   # refers to outer 'a'.
1122     Value *InitVal;
1123     if (Init) {
1124       InitVal = Init->Codegen();
1125       if (InitVal == 0) return 0;
1126     } else { // If not specified, use 0.0.
1127       InitVal = ConstantFP::get(TheContext, APFloat(0.0));
1128     }
1129
1130     AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
1131     Builder.CreateStore(InitVal, Alloca);
1132
1133     // Remember the old variable binding so that we can restore the binding when
1134     // we unrecurse.
1135     OldBindings.push_back(NamedValues[VarName]);
1136
1137     // Remember this binding.
1138     NamedValues[VarName] = Alloca;
1139   }
1140
1141   // Codegen the body, now that all vars are in scope.
1142   Value *BodyVal = Body->Codegen();
1143   if (BodyVal == 0) return 0;
1144
1145   // Pop all our variables from scope.
1146   for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
1147     NamedValues[VarNames[i].first] = OldBindings[i];
1148
1149   // Return the body computation.
1150   return BodyVal;
1151 }
1152
1153 Function *PrototypeAST::Codegen() {
1154   // Make the function type:  double(double,double) etc.
1155   std::vector<Type *> Doubles(Args.size(), Type::getDoubleTy(TheContext));
1156   FunctionType *FT =
1157       FunctionType::get(Type::getDoubleTy(TheContext), Doubles, false);
1158
1159   std::string FnName = MakeLegalFunctionName(Name);
1160
1161   Module* M = TheHelper->getModuleForNewFunction();
1162
1163   Function *F = Function::Create(FT, Function::ExternalLinkage, FnName, M);
1164
1165   // If F conflicted, there was already something named 'FnName'.  If it has a
1166   // body, don't allow redefinition or reextern.
1167   if (F->getName() != FnName) {
1168     // Delete the one we just made and get the existing one.
1169     F->eraseFromParent();
1170     F = M->getFunction(Name);
1171
1172     // If F already has a body, reject this.
1173     if (!F->empty()) {
1174       ErrorF("redefinition of function");
1175       return 0;
1176     }
1177
1178     // If F took a different number of args, reject.
1179     if (F->arg_size() != Args.size()) {
1180       ErrorF("redefinition of function with different # args");
1181       return 0;
1182     }
1183   }
1184
1185   // Set names for all arguments.
1186   unsigned Idx = 0;
1187   for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
1188        ++AI, ++Idx)
1189     AI->setName(Args[Idx]);
1190
1191   return F;
1192 }
1193
1194 /// CreateArgumentAllocas - Create an alloca for each argument and register the
1195 /// argument in the symbol table so that references to it will succeed.
1196 void PrototypeAST::CreateArgumentAllocas(Function *F) {
1197   Function::arg_iterator AI = F->arg_begin();
1198   for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
1199     // Create an alloca for this variable.
1200     AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
1201
1202     // Store the initial value into the alloca.
1203     Builder.CreateStore(AI, Alloca);
1204
1205     // Add arguments to variable symbol table.
1206     NamedValues[Args[Idx]] = Alloca;
1207   }
1208 }
1209
1210 Function *FunctionAST::Codegen() {
1211   NamedValues.clear();
1212
1213   Function *TheFunction = Proto->Codegen();
1214   if (TheFunction == 0)
1215     return 0;
1216
1217   // If this is an operator, install it.
1218   if (Proto->isBinaryOp())
1219     BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
1220
1221   // Create a new basic block to start insertion into.
1222   BasicBlock *BB = BasicBlock::Create(TheContext, "entry", TheFunction);
1223   Builder.SetInsertPoint(BB);
1224
1225   // Add all arguments to the symbol table and create their allocas.
1226   Proto->CreateArgumentAllocas(TheFunction);
1227
1228   if (Value *RetVal = Body->Codegen()) {
1229     // Finish off the function.
1230     Builder.CreateRet(RetVal);
1231
1232     // Validate the generated code, checking for consistency.
1233     verifyFunction(*TheFunction);
1234
1235     return TheFunction;
1236   }
1237
1238   // Error reading body, remove function.
1239   TheFunction->eraseFromParent();
1240
1241   if (Proto->isBinaryOp())
1242     BinopPrecedence.erase(Proto->getOperatorName());
1243   return 0;
1244 }
1245
1246 //===----------------------------------------------------------------------===//
1247 // Top-Level parsing and JIT Driver
1248 //===----------------------------------------------------------------------===//
1249
1250 static void HandleDefinition() {
1251   if (FunctionAST *F = ParseDefinition()) {
1252     if (Function *LF = F->Codegen()) {
1253 #ifndef MINIMAL_STDERR_OUTPUT
1254       fprintf(stderr, "Read function definition:");
1255       LF->print(errs());
1256       fprintf(stderr, "\n");
1257 #endif
1258     }
1259   } else {
1260     // Skip token for error recovery.
1261     getNextToken();
1262   }
1263 }
1264
1265 static void HandleExtern() {
1266   if (PrototypeAST *P = ParseExtern()) {
1267     if (Function *F = P->Codegen()) {
1268 #ifndef MINIMAL_STDERR_OUTPUT
1269       fprintf(stderr, "Read extern: ");
1270       F->print(errs());
1271       fprintf(stderr, "\n");
1272 #endif
1273     }
1274   } else {
1275     // Skip token for error recovery.
1276     getNextToken();
1277   }
1278 }
1279
1280 static void HandleTopLevelExpression() {
1281   // Evaluate a top-level expression into an anonymous function.
1282   if (FunctionAST *F = ParseTopLevelExpr()) {
1283     if (Function *LF = F->Codegen()) {
1284       // JIT the function, returning a function pointer.
1285       void *FPtr = TheHelper->getPointerToFunction(LF);
1286
1287       // Cast it to the right type (takes no arguments, returns a double) so we
1288       // can call it as a native function.
1289       double (*FP)() = (double (*)())(intptr_t)FPtr;
1290 #ifdef MINIMAL_STDERR_OUTPUT
1291       FP();
1292 #else
1293       fprintf(stderr, "Evaluated to %f\n", FP());
1294 #endif
1295     }
1296   } else {
1297     // Skip token for error recovery.
1298     getNextToken();
1299   }
1300 }
1301
1302 /// top ::= definition | external | expression | ';'
1303 static void MainLoop() {
1304   while (1) {
1305 #ifndef MINIMAL_STDERR_OUTPUT
1306     fprintf(stderr, "ready> ");
1307 #endif
1308     switch (CurTok) {
1309     case tok_eof:    return;
1310     case ';':        getNextToken(); break;  // ignore top-level semicolons.
1311     case tok_def:    HandleDefinition(); break;
1312     case tok_extern: HandleExtern(); break;
1313     default:         HandleTopLevelExpression(); break;
1314     }
1315   }
1316 }
1317
1318 //===----------------------------------------------------------------------===//
1319 // "Library" functions that can be "extern'd" from user code.
1320 //===----------------------------------------------------------------------===//
1321
1322 /// putchard - putchar that takes a double and returns 0.
1323 extern "C"
1324 double putchard(double X) {
1325   putchar((char)X);
1326   return 0;
1327 }
1328
1329 /// printd - printf that takes a double prints it as "%f\n", returning 0.
1330 extern "C"
1331 double printd(double X) {
1332   printf("%f", X);
1333   return 0;
1334 }
1335
1336 extern "C"
1337 double printlf() {
1338   printf("\n");
1339   return 0;
1340 }
1341
1342 //===----------------------------------------------------------------------===//
1343 // Main driver code.
1344 //===----------------------------------------------------------------------===//
1345
1346 int main() {
1347   InitializeNativeTarget();
1348   InitializeNativeTargetAsmPrinter();
1349   InitializeNativeTargetAsmParser();
1350   LLVMContext &Context = TheContext;
1351
1352   // Install standard binary operators.
1353   // 1 is lowest precedence.
1354   BinopPrecedence['='] = 2;
1355   BinopPrecedence['<'] = 10;
1356   BinopPrecedence['+'] = 20;
1357   BinopPrecedence['-'] = 20;
1358   BinopPrecedence['/'] = 40;
1359   BinopPrecedence['*'] = 40;  // highest.
1360
1361   // Prime the first token.
1362 #ifndef MINIMAL_STDERR_OUTPUT
1363   fprintf(stderr, "ready> ");
1364 #endif
1365   getNextToken();
1366
1367   // Make the helper, which holds all the code.
1368   TheHelper = new MCJITHelper(Context);
1369
1370   // Run the main "interpreter loop" now.
1371   MainLoop();
1372
1373 #ifndef MINIMAL_STDERR_OUTPUT
1374   // Print out all of the generated code.
1375   TheHelper->print(errs());
1376 #endif
1377
1378   return 0;
1379 }