examples/Kaleidoscope/MCJIT/cached/toy.cpp

   1 #define MINIMAL_STDERR_OUTPUT
   2
   3 #include "llvm/Analysis/Passes.h"
   4 #include "llvm/ExecutionEngine/ExecutionEngine.h"
   5 #include "llvm/ExecutionEngine/MCJIT.h"
   6 #include "llvm/ExecutionEngine/ObjectCache.h"
   7 #include "llvm/ExecutionEngine/SectionMemoryManager.h"
   8 #include "llvm/IR/DataLayout.h"
   9 #include "llvm/IR/DerivedTypes.h"
  10 #include "llvm/IR/IRBuilder.h"
  11 #include "llvm/IR/LLVMContext.h"
  12 #include "llvm/IR/LegacyPassManager.h"
  13 #include "llvm/IR/Module.h"
  14 #include "llvm/IR/Verifier.h"
  15 #include "llvm/IRReader/IRReader.h"
  16 #include "llvm/Support/CommandLine.h"
  17 #include "llvm/Support/FileSystem.h"
  18 #include "llvm/Support/Path.h"
  19 #include "llvm/Support/SourceMgr.h"
  20 #include "llvm/Support/TargetSelect.h"
  21 #include "llvm/Support/raw_ostream.h"
  22 #include "llvm/Transforms/Scalar.h"
  23 #include <cctype>
  24 #include <cstdio>
  25 #include <map>
  26 #include <string>
  27 #include <vector>
  28 using namespace llvm;
  29
  30 //===----------------------------------------------------------------------===//
  31 // Command-line options
  32 //===----------------------------------------------------------------------===//
  33
  34 cl::opt<std::string>
  35 InputIR("input-IR",
  36         cl::desc("Specify the name of an IR file to load for function definitions"),
  37         cl::value_desc("input IR file name"));
  38
  39 cl::opt<bool>
  40 UseObjectCache("use-object-cache",
  41                cl::desc("Enable use of the MCJIT object caching"),
  42                cl::init(false));
  43
  44 //===----------------------------------------------------------------------===//
  45 // Lexer
  46 //===----------------------------------------------------------------------===//
  47
  48 // The lexer returns tokens [0-255] if it is an unknown character, otherwise one
  49 // of these for known things.
  50 enum Token {
  51   tok_eof = -1,
  52
  53   // commands
  54   tok_def = -2, tok_extern = -3,
  55
  56   // primary
  57   tok_identifier = -4, tok_number = -5,
  58
  59   // control
  60   tok_if = -6, tok_then = -7, tok_else = -8,
  61   tok_for = -9, tok_in = -10,
  62
  63   // operators
  64   tok_binary = -11, tok_unary = -12,
  65
  66   // var definition
  67   tok_var = -13
  68 };
  69
  70 static std::string IdentifierStr;  // Filled in if tok_identifier
  71 static double NumVal;              // Filled in if tok_number
  72
  73 /// gettok - Return the next token from standard input.
  74 static int gettok() {
  75   static int LastChar = ' ';
  76
  77   // Skip any whitespace.
  78   while (isspace(LastChar))
  79     LastChar = getchar();
  80
  81   if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
  82     IdentifierStr = LastChar;
  83     while (isalnum((LastChar = getchar())))
  84       IdentifierStr += LastChar;
  85
  86     if (IdentifierStr == "def") return tok_def;
  87     if (IdentifierStr == "extern") return tok_extern;
  88     if (IdentifierStr == "if") return tok_if;
  89     if (IdentifierStr == "then") return tok_then;
  90     if (IdentifierStr == "else") return tok_else;
  91     if (IdentifierStr == "for") return tok_for;
  92     if (IdentifierStr == "in") return tok_in;
  93     if (IdentifierStr == "binary") return tok_binary;
  94     if (IdentifierStr == "unary") return tok_unary;
  95     if (IdentifierStr == "var") return tok_var;
  96     return tok_identifier;
  97   }
  98
  99   if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
 100     std::string NumStr;
 101     do {
 102       NumStr += LastChar;
 103       LastChar = getchar();
 104     } while (isdigit(LastChar) || LastChar == '.');
 105
 106     NumVal = strtod(NumStr.c_str(), 0);
 107     return tok_number;
 108   }
 109
 110   if (LastChar == '#') {
 111     // Comment until end of line.
 112     do LastChar = getchar();
 113     while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
 114
 115     if (LastChar != EOF)
 116       return gettok();
 117   }
 118
 119   // Check for end of file.  Don't eat the EOF.
 120   if (LastChar == EOF)
 121     return tok_eof;
 122
 123   // Otherwise, just return the character as its ascii value.
 124   int ThisChar = LastChar;
 125   LastChar = getchar();
 126   return ThisChar;
 127 }
 128
 129 //===----------------------------------------------------------------------===//
 130 // Abstract Syntax Tree (aka Parse Tree)
 131 //===----------------------------------------------------------------------===//
 132
 133 /// ExprAST - Base class for all expression nodes.
 134 class ExprAST {
 135 public:
 136   virtual ~ExprAST() {}
 137   virtual Value *Codegen() = 0;
 138 };
 139
 140 /// NumberExprAST - Expression class for numeric literals like "1.0".
 141 class NumberExprAST : public ExprAST {
 142   double Val;
 143 public:
 144   NumberExprAST(double val) : Val(val) {}
 145   virtual Value *Codegen();
 146 };
 147
 148 /// VariableExprAST - Expression class for referencing a variable, like "a".
 149 class VariableExprAST : public ExprAST {
 150   std::string Name;
 151 public:
 152   VariableExprAST(const std::string &name) : Name(name) {}
 153   const std::string &getName() const { return Name; }
 154   virtual Value *Codegen();
 155 };
 156
 157 /// UnaryExprAST - Expression class for a unary operator.
 158 class UnaryExprAST : public ExprAST {
 159   char Opcode;
 160   ExprAST *Operand;
 161 public:
 162   UnaryExprAST(char opcode, ExprAST *operand)
 163     : Opcode(opcode), Operand(operand) {}
 164   virtual Value *Codegen();
 165 };
 166
 167 /// BinaryExprAST - Expression class for a binary operator.
 168 class BinaryExprAST : public ExprAST {
 169   char Op;
 170   ExprAST *LHS, *RHS;
 171 public:
 172   BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
 173     : Op(op), LHS(lhs), RHS(rhs) {}
 174   virtual Value *Codegen();
 175 };
 176
 177 /// CallExprAST - Expression class for function calls.
 178 class CallExprAST : public ExprAST {
 179   std::string Callee;
 180   std::vector<ExprAST*> Args;
 181 public:
 182   CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
 183     : Callee(callee), Args(args) {}
 184   virtual Value *Codegen();
 185 };
 186
 187 /// IfExprAST - Expression class for if/then/else.
 188 class IfExprAST : public ExprAST {
 189   ExprAST *Cond, *Then, *Else;
 190 public:
 191   IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
 192   : Cond(cond), Then(then), Else(_else) {}
 193   virtual Value *Codegen();
 194 };
 195
 196 /// ForExprAST - Expression class for for/in.
 197 class ForExprAST : public ExprAST {
 198   std::string VarName;
 199   ExprAST *Start, *End, *Step, *Body;
 200 public:
 201   ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
 202              ExprAST *step, ExprAST *body)
 203     : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
 204   virtual Value *Codegen();
 205 };
 206
 207 /// VarExprAST - Expression class for var/in
 208 class VarExprAST : public ExprAST {
 209   std::vector<std::pair<std::string, ExprAST*> > VarNames;
 210   ExprAST *Body;
 211 public:
 212   VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
 213              ExprAST *body)
 214   : VarNames(varnames), Body(body) {}
 215
 216   virtual Value *Codegen();
 217 };
 218
 219 /// PrototypeAST - This class represents the "prototype" for a function,
 220 /// which captures its argument names as well as if it is an operator.
 221 class PrototypeAST {
 222   std::string Name;
 223   std::vector<std::string> Args;
 224   bool isOperator;
 225   unsigned Precedence;  // Precedence if a binary op.
 226 public:
 227   PrototypeAST(const std::string &name, const std::vector<std::string> &args,
 228                bool isoperator = false, unsigned prec = 0)
 229   : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
 230
 231   bool isUnaryOp() const { return isOperator && Args.size() == 1; }
 232   bool isBinaryOp() const { return isOperator && Args.size() == 2; }
 233
 234   char getOperatorName() const {
 235     assert(isUnaryOp() || isBinaryOp());
 236     return Name[Name.size()-1];
 237   }
 238
 239   unsigned getBinaryPrecedence() const { return Precedence; }
 240
 241   Function *Codegen();
 242
 243   void CreateArgumentAllocas(Function *F);
 244 };
 245
 246 /// FunctionAST - This class represents a function definition itself.
 247 class FunctionAST {
 248   PrototypeAST *Proto;
 249   ExprAST *Body;
 250 public:
 251   FunctionAST(PrototypeAST *proto, ExprAST *body)
 252     : Proto(proto), Body(body) {}
 253
 254   Function *Codegen();
 255 };
 256
 257 //===----------------------------------------------------------------------===//
 258 // Parser
 259 //===----------------------------------------------------------------------===//
 260
 261 /// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
 262 /// token the parser is looking at.  getNextToken reads another token from the
 263 /// lexer and updates CurTok with its results.
 264 static int CurTok;
 265 static int getNextToken() {
 266   return CurTok = gettok();
 267 }
 268
 269 /// BinopPrecedence - This holds the precedence for each binary operator that is
 270 /// defined.
 271 static std::map<char, int> BinopPrecedence;
 272
 273 /// GetTokPrecedence - Get the precedence of the pending binary operator token.
 274 static int GetTokPrecedence() {
 275   if (!isascii(CurTok))
 276     return -1;
 277
 278   // Make sure it's a declared binop.
 279   int TokPrec = BinopPrecedence[CurTok];
 280   if (TokPrec <= 0) return -1;
 281   return TokPrec;
 282 }
 283
 284 /// Error* - These are little helper functions for error handling.
 285 ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
 286 PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
 287 FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
 288
 289 static ExprAST *ParseExpression();
 290
 291 /// identifierexpr
 292 ///   ::= identifier
 293 ///   ::= identifier '(' expression* ')'
 294 static ExprAST *ParseIdentifierExpr() {
 295   std::string IdName = IdentifierStr;
 296
 297   getNextToken();  // eat identifier.
 298
 299   if (CurTok != '(') // Simple variable ref.
 300     return new VariableExprAST(IdName);
 301
 302   // Call.
 303   getNextToken();  // eat (
 304   std::vector<ExprAST*> Args;
 305   if (CurTok != ')') {
 306     while (1) {
 307       ExprAST *Arg = ParseExpression();
 308       if (!Arg) return 0;
 309       Args.push_back(Arg);
 310
 311       if (CurTok == ')') break;
 312
 313       if (CurTok != ',')
 314         return Error("Expected ')' or ',' in argument list");
 315       getNextToken();
 316     }
 317   }
 318
 319   // Eat the ')'.
 320   getNextToken();
 321
 322   return new CallExprAST(IdName, Args);
 323 }
 324
 325 /// numberexpr ::= number
 326 static ExprAST *ParseNumberExpr() {
 327   ExprAST *Result = new NumberExprAST(NumVal);
 328   getNextToken(); // consume the number
 329   return Result;
 330 }
 331
 332 /// parenexpr ::= '(' expression ')'
 333 static ExprAST *ParseParenExpr() {
 334   getNextToken();  // eat (.
 335   ExprAST *V = ParseExpression();
 336   if (!V) return 0;
 337
 338   if (CurTok != ')')
 339     return Error("expected ')'");
 340   getNextToken();  // eat ).
 341   return V;
 342 }
 343
 344 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
 345 static ExprAST *ParseIfExpr() {
 346   getNextToken();  // eat the if.
 347
 348   // condition.
 349   ExprAST *Cond = ParseExpression();
 350   if (!Cond) return 0;
 351
 352   if (CurTok != tok_then)
 353     return Error("expected then");
 354   getNextToken();  // eat the then
 355
 356   ExprAST *Then = ParseExpression();
 357   if (Then == 0) return 0;
 358
 359   if (CurTok != tok_else)
 360     return Error("expected else");
 361
 362   getNextToken();
 363
 364   ExprAST *Else = ParseExpression();
 365   if (!Else) return 0;
 366
 367   return new IfExprAST(Cond, Then, Else);
 368 }
 369
 370 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
 371 static ExprAST *ParseForExpr() {
 372   getNextToken();  // eat the for.
 373
 374   if (CurTok != tok_identifier)
 375     return Error("expected identifier after for");
 376
 377   std::string IdName = IdentifierStr;
 378   getNextToken();  // eat identifier.
 379
 380   if (CurTok != '=')
 381     return Error("expected '=' after for");
 382   getNextToken();  // eat '='.
 383
 384
 385   ExprAST *Start = ParseExpression();
 386   if (Start == 0) return 0;
 387   if (CurTok != ',')
 388     return Error("expected ',' after for start value");
 389   getNextToken();
 390
 391   ExprAST *End = ParseExpression();
 392   if (End == 0) return 0;
 393
 394   // The step value is optional.
 395   ExprAST *Step = 0;
 396   if (CurTok == ',') {
 397     getNextToken();
 398     Step = ParseExpression();
 399     if (Step == 0) return 0;
 400   }
 401
 402   if (CurTok != tok_in)
 403     return Error("expected 'in' after for");
 404   getNextToken();  // eat 'in'.
 405
 406   ExprAST *Body = ParseExpression();
 407   if (Body == 0) return 0;
 408
 409   return new ForExprAST(IdName, Start, End, Step, Body);
 410 }
 411
 412 /// varexpr ::= 'var' identifier ('=' expression)?
 413 //                    (',' identifier ('=' expression)?)* 'in' expression
 414 static ExprAST *ParseVarExpr() {
 415   getNextToken();  // eat the var.
 416
 417   std::vector<std::pair<std::string, ExprAST*> > VarNames;
 418
 419   // At least one variable name is required.
 420   if (CurTok != tok_identifier)
 421     return Error("expected identifier after var");
 422
 423   while (1) {
 424     std::string Name = IdentifierStr;
 425     getNextToken();  // eat identifier.
 426
 427     // Read the optional initializer.
 428     ExprAST *Init = 0;
 429     if (CurTok == '=') {
 430       getNextToken(); // eat the '='.
 431
 432       Init = ParseExpression();
 433       if (Init == 0) return 0;
 434     }
 435
 436     VarNames.push_back(std::make_pair(Name, Init));
 437
 438     // End of var list, exit loop.
 439     if (CurTok != ',') break;
 440     getNextToken(); // eat the ','.
 441
 442     if (CurTok != tok_identifier)
 443       return Error("expected identifier list after var");
 444   }
 445
 446   // At this point, we have to have 'in'.
 447   if (CurTok != tok_in)
 448     return Error("expected 'in' keyword after 'var'");
 449   getNextToken();  // eat 'in'.
 450
 451   ExprAST *Body = ParseExpression();
 452   if (Body == 0) return 0;
 453
 454   return new VarExprAST(VarNames, Body);
 455 }
 456
 457 /// primary
 458 ///   ::= identifierexpr
 459 ///   ::= numberexpr
 460 ///   ::= parenexpr
 461 ///   ::= ifexpr
 462 ///   ::= forexpr
 463 ///   ::= varexpr
 464 static ExprAST *ParsePrimary() {
 465   switch (CurTok) {
 466   default: return Error("unknown token when expecting an expression");
 467   case tok_identifier: return ParseIdentifierExpr();
 468   case tok_number:     return ParseNumberExpr();
 469   case '(':            return ParseParenExpr();
 470   case tok_if:         return ParseIfExpr();
 471   case tok_for:        return ParseForExpr();
 472   case tok_var:        return ParseVarExpr();
 473   }
 474 }
 475
 476 /// unary
 477 ///   ::= primary
 478 ///   ::= '!' unary
 479 static ExprAST *ParseUnary() {
 480   // If the current token is not an operator, it must be a primary expr.
 481   if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
 482     return ParsePrimary();
 483
 484   // If this is a unary operator, read it.
 485   int Opc = CurTok;
 486   getNextToken();
 487   if (ExprAST *Operand = ParseUnary())
 488     return new UnaryExprAST(Opc, Operand);
 489   return 0;
 490 }
 491
 492 /// binoprhs
 493 ///   ::= ('+' unary)*
 494 static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
 495   // If this is a binop, find its precedence.
 496   while (1) {
 497     int TokPrec = GetTokPrecedence();
 498
 499     // If this is a binop that binds at least as tightly as the current binop,
 500     // consume it, otherwise we are done.
 501     if (TokPrec < ExprPrec)
 502       return LHS;
 503
 504     // Okay, we know this is a binop.
 505     int BinOp = CurTok;
 506     getNextToken();  // eat binop
 507
 508     // Parse the unary expression after the binary operator.
 509     ExprAST *RHS = ParseUnary();
 510     if (!RHS) return 0;
 511
 512     // If BinOp binds less tightly with RHS than the operator after RHS, let
 513     // the pending operator take RHS as its LHS.
 514     int NextPrec = GetTokPrecedence();
 515     if (TokPrec < NextPrec) {
 516       RHS = ParseBinOpRHS(TokPrec+1, RHS);
 517       if (RHS == 0) return 0;
 518     }
 519
 520     // Merge LHS/RHS.
 521     LHS = new BinaryExprAST(BinOp, LHS, RHS);
 522   }
 523 }
 524
 525 /// expression
 526 ///   ::= unary binoprhs
 527 ///
 528 static ExprAST *ParseExpression() {
 529   ExprAST *LHS = ParseUnary();
 530   if (!LHS) return 0;
 531
 532   return ParseBinOpRHS(0, LHS);
 533 }
 534
 535 /// prototype
 536 ///   ::= id '(' id* ')'
 537 ///   ::= binary LETTER number? (id, id)
 538 ///   ::= unary LETTER (id)
 539 static PrototypeAST *ParsePrototype() {
 540   std::string FnName;
 541
 542   unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
 543   unsigned BinaryPrecedence = 30;
 544
 545   switch (CurTok) {
 546   default:
 547     return ErrorP("Expected function name in prototype");
 548   case tok_identifier:
 549     FnName = IdentifierStr;
 550     Kind = 0;
 551     getNextToken();
 552     break;
 553   case tok_unary:
 554     getNextToken();
 555     if (!isascii(CurTok))
 556       return ErrorP("Expected unary operator");
 557     FnName = "unary";
 558     FnName += (char)CurTok;
 559     Kind = 1;
 560     getNextToken();
 561     break;
 562   case tok_binary:
 563     getNextToken();
 564     if (!isascii(CurTok))
 565       return ErrorP("Expected binary operator");
 566     FnName = "binary";
 567     FnName += (char)CurTok;
 568     Kind = 2;
 569     getNextToken();
 570
 571     // Read the precedence if present.
 572     if (CurTok == tok_number) {
 573       if (NumVal < 1 || NumVal > 100)
 574         return ErrorP("Invalid precedecnce: must be 1..100");
 575       BinaryPrecedence = (unsigned)NumVal;
 576       getNextToken();
 577     }
 578     break;
 579   }
 580
 581   if (CurTok != '(')
 582     return ErrorP("Expected '(' in prototype");
 583
 584   std::vector<std::string> ArgNames;
 585   while (getNextToken() == tok_identifier)
 586     ArgNames.push_back(IdentifierStr);
 587   if (CurTok != ')')
 588     return ErrorP("Expected ')' in prototype");
 589
 590   // success.
 591   getNextToken();  // eat ')'.
 592
 593   // Verify right number of names for operator.
 594   if (Kind && ArgNames.size() != Kind)
 595     return ErrorP("Invalid number of operands for operator");
 596
 597   return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
 598 }
 599
 600 /// definition ::= 'def' prototype expression
 601 static FunctionAST *ParseDefinition() {
 602   getNextToken();  // eat def.
 603   PrototypeAST *Proto = ParsePrototype();
 604   if (Proto == 0) return 0;
 605
 606   if (ExprAST *E = ParseExpression())
 607     return new FunctionAST(Proto, E);
 608   return 0;
 609 }
 610
 611 /// toplevelexpr ::= expression
 612 static FunctionAST *ParseTopLevelExpr() {
 613   if (ExprAST *E = ParseExpression()) {
 614     // Make an anonymous proto.
 615     PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
 616     return new FunctionAST(Proto, E);
 617   }
 618   return 0;
 619 }
 620
 621 /// external ::= 'extern' prototype
 622 static PrototypeAST *ParseExtern() {
 623   getNextToken();  // eat extern.
 624   return ParsePrototype();
 625 }
 626
 627 //===----------------------------------------------------------------------===//
 628 // Quick and dirty hack
 629 //===----------------------------------------------------------------------===//
 630
 631 // FIXME: Obviously we can do better than this
 632 std::string GenerateUniqueName(const char *root)
 633 {
 634   static int i = 0;
 635   char s[16];
 636   sprintf(s, "%s%d", root, i++);
 637   std::string S = s;
 638   return S;
 639 }
 640
 641 std::string MakeLegalFunctionName(std::string Name)
 642 {
 643   std::string NewName;
 644   if (!Name.length())
 645       return GenerateUniqueName("anon_func_");
 646
 647   // Start with what we have
 648   NewName = Name;
 649
 650   // Look for a numberic first character
 651   if (NewName.find_first_of("0123456789") == 0) {
 652     NewName.insert(0, 1, 'n');
 653   }
 654
 655   // Replace illegal characters with their ASCII equivalent
 656   std::string legal_elements = "_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
 657   size_t pos;
 658   while ((pos = NewName.find_first_not_of(legal_elements)) != std::string::npos) {
 659     char old_c = NewName.at(pos);
 660     char new_str[16];
 661     sprintf(new_str, "%d", (int)old_c);
 662     NewName = NewName.replace(pos, 1, new_str);
 663   }
 664
 665   return NewName;
 666 }
 667
 668 //===----------------------------------------------------------------------===//
 669 // MCJIT object cache class
 670 //===----------------------------------------------------------------------===//
 671
 672 class MCJITObjectCache : public ObjectCache {
 673 public:
 674   MCJITObjectCache() {
 675     // Set IR cache directory
 676     sys::fs::current_path(CacheDir);
 677     sys::path::append(CacheDir, "toy_object_cache");
 678   }
 679
 680   virtual ~MCJITObjectCache() {
 681   }
 682
 683   virtual void notifyObjectCompiled(const Module *M, const MemoryBuffer *Obj) {
 684     // Get the ModuleID
 685     const std::string ModuleID = M->getModuleIdentifier();
 686
 687     // If we've flagged this as an IR file, cache it
 688     if (0 == ModuleID.compare(0, 3, "IR:")) {
 689       std::string IRFileName = ModuleID.substr(3);
 690       SmallString<128>IRCacheFile = CacheDir;
 691       sys::path::append(IRCacheFile, IRFileName);
 692       if (!sys::fs::exists(CacheDir.str()) && sys::fs::create_directory(CacheDir.str())) {
 693         fprintf(stderr, "Unable to create cache directory\n");
 694         return;
 695       }
 696       std::string ErrStr;
 697       raw_fd_ostream IRObjectFile(IRCacheFile.c_str(), ErrStr, raw_fd_ostream::F_Binary);
 698       IRObjectFile << Obj->getBuffer();
 699     }
 700   }
 701
 702   // MCJIT will call this function before compiling any module
 703   // MCJIT takes ownership of both the MemoryBuffer object and the memory
 704   // to which it refers.
 705   virtual MemoryBuffer* getObject(const Module* M) {
 706     // Get the ModuleID
 707     const std::string ModuleID = M->getModuleIdentifier();
 708
 709     // If we've flagged this as an IR file, cache it
 710     if (0 == ModuleID.compare(0, 3, "IR:")) {
 711       std::string IRFileName = ModuleID.substr(3);
 712       SmallString<128> IRCacheFile = CacheDir;
 713       sys::path::append(IRCacheFile, IRFileName);
 714       if (!sys::fs::exists(IRCacheFile.str())) {
 715         // This file isn't in our cache
 716         return NULL;
 717       }
 718       std::unique_ptr<MemoryBuffer> IRObjectBuffer;
 719       MemoryBuffer::getFile(IRCacheFile.c_str(), IRObjectBuffer, -1, false);
 720       // MCJIT will want to write into this buffer, and we don't want that
 721       // because the file has probably just been mmapped.  Instead we make
 722       // a copy.  The filed-based buffer will be released when it goes
 723       // out of scope.
 724       return MemoryBuffer::getMemBufferCopy(IRObjectBuffer->getBuffer());
 725     }
 726
 727     return NULL;
 728   }
 729
 730 private:
 731   SmallString<128> CacheDir;
 732 };
 733
 734 //===----------------------------------------------------------------------===//
 735 // MCJIT helper class
 736 //===----------------------------------------------------------------------===//
 737
 738 class MCJITHelper
 739 {
 740 public:
 741   MCJITHelper(LLVMContext& C) : Context(C), OpenModule(NULL) {}
 742   ~MCJITHelper();
 743
 744   Function *getFunction(const std::string FnName);
 745   Module *getModuleForNewFunction();
 746   void *getPointerToFunction(Function* F);
 747   void *getPointerToNamedFunction(const std::string &Name);
 748   ExecutionEngine *compileModule(Module *M);
 749   void closeCurrentModule();
 750   void addModule(Module *M);
 751   void dump();
 752
 753 private:
 754   typedef std::vector<Module*> ModuleVector;
 755
 756   LLVMContext  &Context;
 757   Module       *OpenModule;
 758   ModuleVector  Modules;
 759   std::map<Module *, ExecutionEngine *> EngineMap;
 760   MCJITObjectCache OurObjectCache;
 761 };
 762
 763 class HelpingMemoryManager : public SectionMemoryManager
 764 {
 765   HelpingMemoryManager(const HelpingMemoryManager&) = delete;
 766   void operator=(const HelpingMemoryManager&) = delete;
 767
 768 public:
 769   HelpingMemoryManager(MCJITHelper *Helper) : MasterHelper(Helper) {}
 770   virtual ~HelpingMemoryManager() {}
 771
 772   /// This method returns the address of the specified function.
 773   /// Our implementation will attempt to find functions in other
 774   /// modules associated with the MCJITHelper to cross link functions
 775   /// from one generated module to another.
 776   ///
 777   /// If \p AbortOnFailure is false and no function with the given name is
 778   /// found, this function returns a null pointer. Otherwise, it prints a
 779   /// message to stderr and aborts.
 780   virtual void *getPointerToNamedFunction(const std::string &Name,
 781                                           bool AbortOnFailure = true);
 782 private:
 783   MCJITHelper *MasterHelper;
 784 };
 785
 786 void *HelpingMemoryManager::getPointerToNamedFunction(const std::string &Name,
 787                                         bool AbortOnFailure)
 788 {
 789   // Try the standard symbol resolution first, but ask it not to abort.
 790   void *pfn = SectionMemoryManager::getPointerToNamedFunction(Name, false);
 791   if (pfn)
 792     return pfn;
 793
 794   pfn = MasterHelper->getPointerToNamedFunction(Name);
 795   if (!pfn && AbortOnFailure)
 796     report_fatal_error("Program used external function '" + Name +
 797                         "' which could not be resolved!");
 798   return pfn;
 799 }
 800
 801 MCJITHelper::~MCJITHelper()
 802 {
 803   // Walk the vector of modules.
 804   ModuleVector::iterator it, end;
 805   for (it = Modules.begin(), end = Modules.end();
 806        it != end; ++it) {
 807     // See if we have an execution engine for this module.
 808     std::map<Module*, ExecutionEngine*>::iterator mapIt = EngineMap.find(*it);
 809     // If we have an EE, the EE owns the module so just delete the EE.
 810     if (mapIt != EngineMap.end()) {
 811       delete mapIt->second;
 812     } else {
 813       // Otherwise, we still own the module.  Delete it now.
 814       delete *it;
 815     }
 816   }
 817 }
 818
 819 Function *MCJITHelper::getFunction(const std::string FnName) {
 820   ModuleVector::iterator begin = Modules.begin();
 821   ModuleVector::iterator end = Modules.end();
 822   ModuleVector::iterator it;
 823   for (it = begin; it != end; ++it) {
 824     Function *F = (*it)->getFunction(FnName);
 825     if (F) {
 826       if (*it == OpenModule)
 827           return F;
 828
 829       assert(OpenModule != NULL);
 830
 831       // This function is in a module that has already been JITed.
 832       // We need to generate a new prototype for external linkage.
 833       Function *PF = OpenModule->getFunction(FnName);
 834       if (PF && !PF->empty()) {
 835         ErrorF("redefinition of function across modules");
 836         return 0;
 837       }
 838
 839       // If we don't have a prototype yet, create one.
 840       if (!PF)
 841         PF = Function::Create(F->getFunctionType(),
 842                                       Function::ExternalLinkage,
 843                                       FnName,
 844                                       OpenModule);
 845       return PF;
 846     }
 847   }
 848   return NULL;
 849 }
 850
 851 Module *MCJITHelper::getModuleForNewFunction() {
 852   // If we have a Module that hasn't been JITed, use that.
 853   if (OpenModule)
 854     return OpenModule;
 855
 856   // Otherwise create a new Module.
 857   std::string ModName = GenerateUniqueName("mcjit_module_");
 858   Module *M = new Module(ModName, Context);
 859   Modules.push_back(M);
 860   OpenModule = M;
 861   return M;
 862 }
 863
 864 void *MCJITHelper::getPointerToFunction(Function* F) {
 865   // Look for this function in an existing module
 866   ModuleVector::iterator begin = Modules.begin();
 867   ModuleVector::iterator end = Modules.end();
 868   ModuleVector::iterator it;
 869   std::string FnName = F->getName();
 870   for (it = begin; it != end; ++it) {
 871     Function *MF = (*it)->getFunction(FnName);
 872     if (MF == F) {
 873       std::map<Module*, ExecutionEngine*>::iterator eeIt = EngineMap.find(*it);
 874       if (eeIt != EngineMap.end()) {
 875         void *P = eeIt->second->getPointerToFunction(F);
 876         if (P)
 877           return P;
 878       } else {
 879         ExecutionEngine *EE = compileModule(*it);
 880         void *P = EE->getPointerToFunction(F);
 881         if (P)
 882           return P;
 883       }
 884     }
 885   }
 886   return NULL;
 887 }
 888
 889 void MCJITHelper::closeCurrentModule() {
 890   OpenModule = NULL;
 891 }
 892
 893 ExecutionEngine *MCJITHelper::compileModule(Module *M) {
 894   if (M == OpenModule)
 895     closeCurrentModule();
 896
 897   std::string ErrStr;
 898   ExecutionEngine *NewEngine = EngineBuilder(M)
 899                                             .setErrorStr(&ErrStr)
 900                                             .setMCJITMemoryManager(new HelpingMemoryManager(this))
 901                                             .create();
 902   if (!NewEngine) {
 903     fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
 904     exit(1);
 905   }
 906
 907   if (UseObjectCache)
 908     NewEngine->setObjectCache(&OurObjectCache);
 909
 910   // Get the ModuleID so we can identify IR input files
 911   const std::string ModuleID = M->getModuleIdentifier();
 912
 913   // If we've flagged this as an IR file, it doesn't need function passes run.
 914   if (0 != ModuleID.compare(0, 3, "IR:")) {
 915     // Create a function pass manager for this engine
 916     FunctionPassManager *FPM = new FunctionPassManager(M);
 917
 918     // Set up the optimizer pipeline.  Start with registering info about how the
 919     // target lays out data structures.
 920     FPM->add(new DataLayout(*NewEngine->getDataLayout()));
 921     // Provide basic AliasAnalysis support for GVN.
 922     FPM->add(createBasicAliasAnalysisPass());
 923     // Promote allocas to registers.
 924     FPM->add(createPromoteMemoryToRegisterPass());
 925     // Do simple "peephole" optimizations and bit-twiddling optzns.
 926     FPM->add(createInstructionCombiningPass());
 927     // Reassociate expressions.
 928     FPM->add(createReassociatePass());
 929     // Eliminate Common SubExpressions.
 930     FPM->add(createGVNPass());
 931     // Simplify the control flow graph (deleting unreachable blocks, etc).
 932     FPM->add(createCFGSimplificationPass());
 933     FPM->doInitialization();
 934
 935     // For each function in the module
 936     Module::iterator it;
 937     Module::iterator end = M->end();
 938     for (it = M->begin(); it != end; ++it) {
 939       // Run the FPM on this function
 940       FPM->run(*it);
 941     }
 942
 943     // We don't need this anymore
 944     delete FPM;
 945   }
 946
 947   // Store this engine
 948   EngineMap[M] = NewEngine;
 949   NewEngine->finalizeObject();
 950
 951   return NewEngine;
 952 }
 953
 954 void *MCJITHelper::getPointerToNamedFunction(const std::string &Name)
 955 {
 956   // Look for the functions in our modules, compiling only as necessary
 957   ModuleVector::iterator begin = Modules.begin();
 958   ModuleVector::iterator end = Modules.end();
 959   ModuleVector::iterator it;
 960   for (it = begin; it != end; ++it) {
 961     Function *F = (*it)->getFunction(Name);
 962     if (F && !F->empty()) {
 963       std::map<Module*, ExecutionEngine*>::iterator eeIt = EngineMap.find(*it);
 964       if (eeIt != EngineMap.end()) {
 965         void *P = eeIt->second->getPointerToFunction(F);
 966         if (P)
 967           return P;
 968       } else {
 969         ExecutionEngine *EE = compileModule(*it);
 970         void *P = EE->getPointerToFunction(F);
 971         if (P)
 972           return P;
 973       }
 974     }
 975   }
 976   return NULL;
 977 }
 978
 979 void MCJITHelper::addModule(Module* M) {
 980   Modules.push_back(M);
 981 }
 982
 983 void MCJITHelper::dump()
 984 {
 985   ModuleVector::iterator begin = Modules.begin();
 986   ModuleVector::iterator end = Modules.end();
 987   ModuleVector::iterator it;
 988   for (it = begin; it != end; ++it)
 989     (*it)->dump();
 990 }
 991
 992 //===----------------------------------------------------------------------===//
 993 // Code Generation
 994 //===----------------------------------------------------------------------===//
 995
 996 static MCJITHelper *TheHelper;
 997 static LLVMContext TheContext;
 998 static IRBuilder<> Builder(TheContext);
 999 static std::map<std::string, AllocaInst*> NamedValues;
1000
1001 Value *ErrorV(const char *Str) { Error(Str); return 0; }
1002
1003 /// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
1004 /// the function.  This is used for mutable variables etc.
1005 static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
1006                                           const std::string &VarName) {
1007   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
1008                  TheFunction->getEntryBlock().begin());
1009   return TmpB.CreateAlloca(Type::getDoubleTy(TheContext), 0, VarName.c_str());
1010 }
1011
1012 Value *NumberExprAST::Codegen() {
1013   return ConstantFP::get(TheContext, APFloat(Val));
1014 }
1015
1016 Value *VariableExprAST::Codegen() {
1017   // Look this variable up in the function.
1018   Value *V = NamedValues[Name];
1019   char ErrStr[256];
1020   sprintf(ErrStr, "Unknown variable name %s", Name.c_str());
1021   if (V == 0) return ErrorV(ErrStr);
1022
1023   // Load the value.
1024   return Builder.CreateLoad(V, Name.c_str());
1025 }
1026
1027 Value *UnaryExprAST::Codegen() {
1028   Value *OperandV = Operand->Codegen();
1029   if (OperandV == 0) return 0;
1030
1031   Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("unary")+Opcode));
1032   if (F == 0)
1033     return ErrorV("Unknown unary operator");
1034
1035   return Builder.CreateCall(F, OperandV, "unop");
1036 }
1037
1038 Value *BinaryExprAST::Codegen() {
1039   // Special case '=' because we don't want to emit the LHS as an expression.
1040   if (Op == '=') {
1041     // Assignment requires the LHS to be an identifier.
1042     VariableExprAST *LHSE = static_cast<VariableExprAST*>(LHS);
1043     if (!LHSE)
1044       return ErrorV("destination of '=' must be a variable");
1045     // Codegen the RHS.
1046     Value *Val = RHS->Codegen();
1047     if (Val == 0) return 0;
1048
1049     // Look up the name.
1050     Value *Variable = NamedValues[LHSE->getName()];
1051     if (Variable == 0) return ErrorV("Unknown variable name");
1052
1053     Builder.CreateStore(Val, Variable);
1054     return Val;
1055   }
1056
1057   Value *L = LHS->Codegen();
1058   Value *R = RHS->Codegen();
1059   if (L == 0 || R == 0) return 0;
1060
1061   switch (Op) {
1062   case '+': return Builder.CreateFAdd(L, R, "addtmp");
1063   case '-': return Builder.CreateFSub(L, R, "subtmp");
1064   case '*': return Builder.CreateFMul(L, R, "multmp");
1065   case '/': return Builder.CreateFDiv(L, R, "divtmp");
1066   case '<':
1067     L = Builder.CreateFCmpULT(L, R, "cmptmp");
1068     // Convert bool 0/1 to double 0.0 or 1.0
1069     return Builder.CreateUIToFP(L, Type::getDoubleTy(TheContext), "booltmp");
1070   default: break;
1071   }
1072
1073   // If it wasn't a builtin binary operator, it must be a user defined one. Emit
1074   // a call to it.
1075   Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("binary")+Op));
1076   assert(F && "binary operator not found!");
1077
1078   Value *Ops[] = { L, R };
1079   return Builder.CreateCall(F, Ops, "binop");
1080 }
1081
1082 Value *CallExprAST::Codegen() {
1083   // Look up the name in the global module table.
1084   Function *CalleeF = TheHelper->getFunction(Callee);
1085   if (CalleeF == 0)
1086     return ErrorV("Unknown function referenced");
1087
1088   // If argument mismatch error.
1089   if (CalleeF->arg_size() != Args.size())
1090     return ErrorV("Incorrect # arguments passed");
1091
1092   std::vector<Value*> ArgsV;
1093   for (unsigned i = 0, e = Args.size(); i != e; ++i) {
1094     ArgsV.push_back(Args[i]->Codegen());
1095     if (ArgsV.back() == 0) return 0;
1096   }
1097
1098   return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
1099 }
1100
1101 Value *IfExprAST::Codegen() {
1102   Value *CondV = Cond->Codegen();
1103   if (CondV == 0) return 0;
1104
1105   // Convert condition to a bool by comparing equal to 0.0.
1106   CondV = Builder.CreateFCmpONE(
1107       CondV, ConstantFP::get(TheContext, APFloat(0.0)), "ifcond");
1108
1109   Function *TheFunction = Builder.GetInsertBlock()->getParent();
1110
1111   // Create blocks for the then and else cases.  Insert the 'then' block at the
1112   // end of the function.
1113   BasicBlock *ThenBB = BasicBlock::Create(TheContext, "then", TheFunction);
1114   BasicBlock *ElseBB = BasicBlock::Create(TheContext, "else");
1115   BasicBlock *MergeBB = BasicBlock::Create(TheContext, "ifcont");
1116
1117   Builder.CreateCondBr(CondV, ThenBB, ElseBB);
1118
1119   // Emit then value.
1120   Builder.SetInsertPoint(ThenBB);
1121
1122   Value *ThenV = Then->Codegen();
1123   if (ThenV == 0) return 0;
1124
1125   Builder.CreateBr(MergeBB);
1126   // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
1127   ThenBB = Builder.GetInsertBlock();
1128
1129   // Emit else block.
1130   TheFunction->getBasicBlockList().push_back(ElseBB);
1131   Builder.SetInsertPoint(ElseBB);
1132
1133   Value *ElseV = Else->Codegen();
1134   if (ElseV == 0) return 0;
1135
1136   Builder.CreateBr(MergeBB);
1137   // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
1138   ElseBB = Builder.GetInsertBlock();
1139
1140   // Emit merge block.
1141   TheFunction->getBasicBlockList().push_back(MergeBB);
1142   Builder.SetInsertPoint(MergeBB);
1143   PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(TheContext), 2, "iftmp");
1144
1145   PN->addIncoming(ThenV, ThenBB);
1146   PN->addIncoming(ElseV, ElseBB);
1147   return PN;
1148 }
1149
1150 Value *ForExprAST::Codegen() {
1151   // Output this as:
1152   //   var = alloca double
1153   //   ...
1154   //   start = startexpr
1155   //   store start -> var
1156   //   goto loop
1157   // loop:
1158   //   ...
1159   //   bodyexpr
1160   //   ...
1161   // loopend:
1162   //   step = stepexpr
1163   //   endcond = endexpr
1164   //
1165   //   curvar = load var
1166   //   nextvar = curvar + step
1167   //   store nextvar -> var
1168   //   br endcond, loop, endloop
1169   // outloop:
1170
1171   Function *TheFunction = Builder.GetInsertBlock()->getParent();
1172
1173   // Create an alloca for the variable in the entry block.
1174   AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
1175
1176   // Emit the start code first, without 'variable' in scope.
1177   Value *StartVal = Start->Codegen();
1178   if (StartVal == 0) return 0;
1179
1180   // Store the value into the alloca.
1181   Builder.CreateStore(StartVal, Alloca);
1182
1183   // Make the new basic block for the loop header, inserting after current
1184   // block.
1185   BasicBlock *LoopBB = BasicBlock::Create(TheContext, "loop", TheFunction);
1186
1187   // Insert an explicit fall through from the current block to the LoopBB.
1188   Builder.CreateBr(LoopBB);
1189
1190   // Start insertion in LoopBB.
1191   Builder.SetInsertPoint(LoopBB);
1192
1193   // Within the loop, the variable is defined equal to the PHI node.  If it
1194   // shadows an existing variable, we have to restore it, so save it now.
1195   AllocaInst *OldVal = NamedValues[VarName];
1196   NamedValues[VarName] = Alloca;
1197
1198   // Emit the body of the loop.  This, like any other expr, can change the
1199   // current BB.  Note that we ignore the value computed by the body, but don't
1200   // allow an error.
1201   if (Body->Codegen() == 0)
1202     return 0;
1203
1204   // Emit the step value.
1205   Value *StepVal;
1206   if (Step) {
1207     StepVal = Step->Codegen();
1208     if (StepVal == 0) return 0;
1209   } else {
1210     // If not specified, use 1.0.
1211     StepVal = ConstantFP::get(TheContext, APFloat(1.0));
1212   }
1213
1214   // Compute the end condition.
1215   Value *EndCond = End->Codegen();
1216   if (EndCond == 0) return EndCond;
1217
1218   // Reload, increment, and restore the alloca.  This handles the case where
1219   // the body of the loop mutates the variable.
1220   Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
1221   Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
1222   Builder.CreateStore(NextVar, Alloca);
1223
1224   // Convert condition to a bool by comparing equal to 0.0.
1225   EndCond = Builder.CreateFCmpONE(
1226       EndCond, ConstantFP::get(TheContext, APFloat(0.0)), "loopcond");
1227
1228   // Create the "after loop" block and insert it.
1229   BasicBlock *AfterBB =
1230       BasicBlock::Create(TheContext, "afterloop", TheFunction);
1231
1232   // Insert the conditional branch into the end of LoopEndBB.
1233   Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
1234
1235   // Any new code will be inserted in AfterBB.
1236   Builder.SetInsertPoint(AfterBB);
1237
1238   // Restore the unshadowed variable.
1239   if (OldVal)
1240     NamedValues[VarName] = OldVal;
1241   else
1242     NamedValues.erase(VarName);
1243
1244
1245   // for expr always returns 0.0.
1246   return Constant::getNullValue(Type::getDoubleTy(TheContext));
1247 }
1248
1249 Value *VarExprAST::Codegen() {
1250   std::vector<AllocaInst *> OldBindings;
1251
1252   Function *TheFunction = Builder.GetInsertBlock()->getParent();
1253
1254   // Register all variables and emit their initializer.
1255   for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
1256     const std::string &VarName = VarNames[i].first;
1257     ExprAST *Init = VarNames[i].second;
1258
1259     // Emit the initializer before adding the variable to scope, this prevents
1260     // the initializer from referencing the variable itself, and permits stuff
1261     // like this:
1262     //  var a = 1 in
1263     //    var a = a in ...   # refers to outer 'a'.
1264     Value *InitVal;
1265     if (Init) {
1266       InitVal = Init->Codegen();
1267       if (InitVal == 0) return 0;
1268     } else { // If not specified, use 0.0.
1269       InitVal = ConstantFP::get(TheContext, APFloat(0.0));
1270     }
1271
1272     AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
1273     Builder.CreateStore(InitVal, Alloca);
1274
1275     // Remember the old variable binding so that we can restore the binding when
1276     // we unrecurse.
1277     OldBindings.push_back(NamedValues[VarName]);
1278
1279     // Remember this binding.
1280     NamedValues[VarName] = Alloca;
1281   }
1282
1283   // Codegen the body, now that all vars are in scope.
1284   Value *BodyVal = Body->Codegen();
1285   if (BodyVal == 0) return 0;
1286
1287   // Pop all our variables from scope.
1288   for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
1289     NamedValues[VarNames[i].first] = OldBindings[i];
1290
1291   // Return the body computation.
1292   return BodyVal;
1293 }
1294
1295 Function *PrototypeAST::Codegen() {
1296   // Make the function type:  double(double,double) etc.
1297   std::vector<Type *> Doubles(Args.size(), Type::getDoubleTy(TheContext));
1298   FunctionType *FT =
1299       FunctionType::get(Type::getDoubleTy(TheContext), Doubles, false);
1300
1301   std::string FnName = MakeLegalFunctionName(Name);
1302
1303   Module* M = TheHelper->getModuleForNewFunction();
1304
1305   Function *F = Function::Create(FT, Function::ExternalLinkage, FnName, M);
1306
1307   // If F conflicted, there was already something named 'FnName'.  If it has a
1308   // body, don't allow redefinition or reextern.
1309   if (F->getName() != FnName) {
1310     // Delete the one we just made and get the existing one.
1311     F->eraseFromParent();
1312     F = M->getFunction(Name);
1313
1314     // If F already has a body, reject this.
1315     if (!F->empty()) {
1316       ErrorF("redefinition of function");
1317       return 0;
1318     }
1319
1320     // If F took a different number of args, reject.
1321     if (F->arg_size() != Args.size()) {
1322       ErrorF("redefinition of function with different # args");
1323       return 0;
1324     }
1325   }
1326
1327   // Set names for all arguments.
1328   unsigned Idx = 0;
1329   for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
1330        ++AI, ++Idx)
1331     AI->setName(Args[Idx]);
1332
1333   return F;
1334 }
1335
1336 /// CreateArgumentAllocas - Create an alloca for each argument and register the
1337 /// argument in the symbol table so that references to it will succeed.
1338 void PrototypeAST::CreateArgumentAllocas(Function *F) {
1339   Function::arg_iterator AI = F->arg_begin();
1340   for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
1341     // Create an alloca for this variable.
1342     AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
1343
1344     // Store the initial value into the alloca.
1345     Builder.CreateStore(AI, Alloca);
1346
1347     // Add arguments to variable symbol table.
1348     NamedValues[Args[Idx]] = Alloca;
1349   }
1350 }
1351
1352 Function *FunctionAST::Codegen() {
1353   NamedValues.clear();
1354
1355   Function *TheFunction = Proto->Codegen();
1356   if (TheFunction == 0)
1357     return 0;
1358
1359   // If this is an operator, install it.
1360   if (Proto->isBinaryOp())
1361     BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
1362
1363   // Create a new basic block to start insertion into.
1364   BasicBlock *BB = BasicBlock::Create(TheContext, "entry", TheFunction);
1365   Builder.SetInsertPoint(BB);
1366
1367   // Add all arguments to the symbol table and create their allocas.
1368   Proto->CreateArgumentAllocas(TheFunction);
1369
1370   if (Value *RetVal = Body->Codegen()) {
1371     // Finish off the function.
1372     Builder.CreateRet(RetVal);
1373
1374     // Validate the generated code, checking for consistency.
1375     verifyFunction(*TheFunction);
1376
1377     return TheFunction;
1378   }
1379
1380   // Error reading body, remove function.
1381   TheFunction->eraseFromParent();
1382
1383   if (Proto->isBinaryOp())
1384     BinopPrecedence.erase(Proto->getOperatorName());
1385   return 0;
1386 }
1387
1388 //===----------------------------------------------------------------------===//
1389 // Top-Level parsing and JIT Driver
1390 //===----------------------------------------------------------------------===//
1391
1392 static void HandleDefinition() {
1393   if (FunctionAST *F = ParseDefinition()) {
1394     TheHelper->closeCurrentModule();
1395     if (Function *LF = F->Codegen()) {
1396 #ifndef MINIMAL_STDERR_OUTPUT
1397       fprintf(stderr, "Read function definition:");
1398       LF->print(errs());
1399       fprintf(stderr, "\n");
1400 #endif
1401     }
1402   } else {
1403     // Skip token for error recovery.
1404     getNextToken();
1405   }
1406 }
1407
1408 static void HandleExtern() {
1409   if (PrototypeAST *P = ParseExtern()) {
1410     if (Function *F = P->Codegen()) {
1411 #ifndef MINIMAL_STDERR_OUTPUT
1412       fprintf(stderr, "Read extern: ");
1413       F->print(errs());
1414       fprintf(stderr, "\n");
1415 #endif
1416     }
1417   } else {
1418     // Skip token for error recovery.
1419     getNextToken();
1420   }
1421 }
1422
1423 static void HandleTopLevelExpression() {
1424   // Evaluate a top-level expression into an anonymous function.
1425   if (FunctionAST *F = ParseTopLevelExpr()) {
1426     if (Function *LF = F->Codegen()) {
1427       // JIT the function, returning a function pointer.
1428       void *FPtr = TheHelper->getPointerToFunction(LF);
1429
1430       // Cast it to the right type (takes no arguments, returns a double) so we
1431       // can call it as a native function.
1432       double (*FP)() = (double (*)())(intptr_t)FPtr;
1433 #ifdef MINIMAL_STDERR_OUTPUT
1434       FP();
1435 #else
1436       fprintf(stderr, "Evaluated to %f\n", FP());
1437 #endif
1438     }
1439   } else {
1440     // Skip token for error recovery.
1441     getNextToken();
1442   }
1443 }
1444
1445 /// top ::= definition | external | expression | ';'
1446 static void MainLoop() {
1447   while (1) {
1448 #ifndef MINIMAL_STDERR_OUTPUT
1449     fprintf(stderr, "ready> ");
1450 #endif
1451     switch (CurTok) {
1452     case tok_eof:    return;
1453     case ';':        getNextToken(); break;  // ignore top-level semicolons.
1454     case tok_def:    HandleDefinition(); break;
1455     case tok_extern: HandleExtern(); break;
1456     default:         HandleTopLevelExpression(); break;
1457     }
1458   }
1459 }
1460
1461 //===----------------------------------------------------------------------===//
1462 // "Library" functions that can be "extern'd" from user code.
1463 //===----------------------------------------------------------------------===//
1464
1465 /// putchard - putchar that takes a double and returns 0.
1466 extern "C"
1467 double putchard(double X) {
1468   putchar((char)X);
1469   return 0;
1470 }
1471
1472 /// printd - printf that takes a double prints it as "%f\n", returning 0.
1473 extern "C"
1474 double printd(double X) {
1475   printf("%f", X);
1476   return 0;
1477 }
1478
1479 extern "C"
1480 double printlf() {
1481   printf("\n");
1482   return 0;
1483 }
1484
1485 //===----------------------------------------------------------------------===//
1486 // Command line input file handler
1487 //===----------------------------------------------------------------------===//
1488
1489 Module* parseInputIR(std::string InputFile) {
1490   SMDiagnostic Err;
1491   Module *M = ParseIRFile(InputFile, Err, TheContext);
1492   if (!M) {
1493     Err.print("IR parsing failed: ", errs());
1494     return NULL;
1495   }
1496
1497   char ModID[256];
1498   sprintf(ModID, "IR:%s", InputFile.c_str());
1499   M->setModuleIdentifier(ModID);
1500
1501   TheHelper->addModule(M);
1502   return M;
1503 }
1504
1505 //===----------------------------------------------------------------------===//
1506 // Main driver code.
1507 //===----------------------------------------------------------------------===//
1508
1509 int main(int argc, char **argv) {
1510   InitializeNativeTarget();
1511   InitializeNativeTargetAsmPrinter();
1512   InitializeNativeTargetAsmParser();
1513   LLVMContext &Context = TheContext;
1514
1515   cl::ParseCommandLineOptions(argc, argv,
1516                               "Kaleidoscope example program\n");
1517
1518   // Install standard binary operators.
1519   // 1 is lowest precedence.
1520   BinopPrecedence['='] = 2;
1521   BinopPrecedence['<'] = 10;
1522   BinopPrecedence['+'] = 20;
1523   BinopPrecedence['-'] = 20;
1524   BinopPrecedence['/'] = 40;
1525   BinopPrecedence['*'] = 40;  // highest.
1526
1527   // Prime the first token.
1528 #ifndef MINIMAL_STDERR_OUTPUT
1529   fprintf(stderr, "ready> ");
1530 #endif
1531   getNextToken();
1532
1533   // Make the helper, which holds all the code.
1534   TheHelper = new MCJITHelper(Context);
1535
1536   if (!InputIR.empty()) {
1537     parseInputIR(InputIR);
1538   }
1539
1540   // Run the main "interpreter loop" now.
1541   MainLoop();
1542
1543 #ifndef MINIMAL_STDERR_OUTPUT
1544   // Print out all of the generated code.
1545   TheHelper->print(errs());
1546 #endif
1547
1548   return 0;
1549 }