1#include "llvm/ADT/STLExtras.h"
2#include "llvm/ADT/Triple.h"
3#include "llvm/Analysis/Passes.h"
4#include "llvm/ExecutionEngine/ExecutionEngine.h"
5#include "llvm/ExecutionEngine/MCJIT.h"
6#include "llvm/ExecutionEngine/SectionMemoryManager.h"
7#include "llvm/IR/DIBuilder.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/Support/Host.h"
16#include "llvm/Support/TargetSelect.h"
17#include "llvm/Transforms/Scalar.h"
18#include <cctype>
19#include <cstdio>
20#include <iostream>
21#include <map>
22#include <string>
23#include <vector>
24using namespace llvm;
25
26//===----------------------------------------------------------------------===//
27// Lexer
28//===----------------------------------------------------------------------===//
29
30// The lexer returns tokens [0-255] if it is an unknown character, otherwise one
31// of these for known things.
32enum Token {
33  tok_eof = -1,
34
35  // commands
36  tok_def = -2,
37  tok_extern = -3,
38
39  // primary
40  tok_identifier = -4,
41  tok_number = -5,
42
43  // control
44  tok_if = -6,
45  tok_then = -7,
46  tok_else = -8,
47  tok_for = -9,
48  tok_in = -10,
49
50  // operators
51  tok_binary = -11,
52  tok_unary = -12,
53
54  // var definition
55  tok_var = -13
56};
57
58std::string getTokName(int Tok) {
59  switch (Tok) {
60  case tok_eof:
61    return "eof";
62  case tok_def:
63    return "def";
64  case tok_extern:
65    return "extern";
66  case tok_identifier:
67    return "identifier";
68  case tok_number:
69    return "number";
70  case tok_if:
71    return "if";
72  case tok_then:
73    return "then";
74  case tok_else:
75    return "else";
76  case tok_for:
77    return "for";
78  case tok_in:
79    return "in";
80  case tok_binary:
81    return "binary";
82  case tok_unary:
83    return "unary";
84  case tok_var:
85    return "var";
86  }
87  return std::string(1, (char)Tok);
88}
89
90namespace {
91class PrototypeAST;
92class ExprAST;
93}
94static IRBuilder<> Builder(getGlobalContext());
95struct DebugInfo {
96  DICompileUnit TheCU;
97  DIType DblTy;
98  std::vector<DIScope *> LexicalBlocks;
99  std::map<const PrototypeAST *, DIScope> FnScopeMap;
100
101  void emitLocation(ExprAST *AST);
102  DIType getDoubleTy();
103} KSDbgInfo;
104
105static std::string IdentifierStr; // Filled in if tok_identifier
106static double NumVal;             // Filled in if tok_number
107struct SourceLocation {
108  int Line;
109  int Col;
110};
111static SourceLocation CurLoc;
112static SourceLocation LexLoc = { 1, 0 };
113
114static int advance() {
115  int LastChar = getchar();
116
117  if (LastChar == '\n' || LastChar == '\r') {
118    LexLoc.Line++;
119    LexLoc.Col = 0;
120  } else
121    LexLoc.Col++;
122  return LastChar;
123}
124
125/// gettok - Return the next token from standard input.
126static int gettok() {
127  static int LastChar = ' ';
128
129  // Skip any whitespace.
130  while (isspace(LastChar))
131    LastChar = advance();
132
133  CurLoc = LexLoc;
134
135  if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
136    IdentifierStr = LastChar;
137    while (isalnum((LastChar = advance())))
138      IdentifierStr += LastChar;
139
140    if (IdentifierStr == "def")
141      return tok_def;
142    if (IdentifierStr == "extern")
143      return tok_extern;
144    if (IdentifierStr == "if")
145      return tok_if;
146    if (IdentifierStr == "then")
147      return tok_then;
148    if (IdentifierStr == "else")
149      return tok_else;
150    if (IdentifierStr == "for")
151      return tok_for;
152    if (IdentifierStr == "in")
153      return tok_in;
154    if (IdentifierStr == "binary")
155      return tok_binary;
156    if (IdentifierStr == "unary")
157      return tok_unary;
158    if (IdentifierStr == "var")
159      return tok_var;
160    return tok_identifier;
161  }
162
163  if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
164    std::string NumStr;
165    do {
166      NumStr += LastChar;
167      LastChar = advance();
168    } while (isdigit(LastChar) || LastChar == '.');
169
170    NumVal = strtod(NumStr.c_str(), 0);
171    return tok_number;
172  }
173
174  if (LastChar == '#') {
175    // Comment until end of line.
176    do
177      LastChar = advance();
178    while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
179
180    if (LastChar != EOF)
181      return gettok();
182  }
183
184  // Check for end of file.  Don't eat the EOF.
185  if (LastChar == EOF)
186    return tok_eof;
187
188  // Otherwise, just return the character as its ascii value.
189  int ThisChar = LastChar;
190  LastChar = advance();
191  return ThisChar;
192}
193
194//===----------------------------------------------------------------------===//
195// Abstract Syntax Tree (aka Parse Tree)
196//===----------------------------------------------------------------------===//
197namespace {
198
199std::ostream &indent(std::ostream &O, int size) {
200  return O << std::string(size, ' ');
201}
202
203/// ExprAST - Base class for all expression nodes.
204class ExprAST {
205  SourceLocation Loc;
206
207public:
208  int getLine() const { return Loc.Line; }
209  int getCol() const { return Loc.Col; }
210  ExprAST(SourceLocation Loc = CurLoc) : Loc(Loc) {}
211  virtual std::ostream &dump(std::ostream &out, int ind) {
212    return out << ':' << getLine() << ':' << getCol() << '\n';
213  }
214  virtual ~ExprAST() {}
215  virtual Value *Codegen() = 0;
216};
217
218/// NumberExprAST - Expression class for numeric literals like "1.0".
219class NumberExprAST : public ExprAST {
220  double Val;
221
222public:
223  NumberExprAST(double val) : Val(val) {}
224  std::ostream &dump(std::ostream &out, int ind) override {
225    return ExprAST::dump(out << Val, ind);
226  }
227  Value *Codegen() override;
228};
229
230/// VariableExprAST - Expression class for referencing a variable, like "a".
231class VariableExprAST : public ExprAST {
232  std::string Name;
233
234public:
235  VariableExprAST(SourceLocation Loc, const std::string &name)
236      : ExprAST(Loc), Name(name) {}
237  const std::string &getName() const { return Name; }
238  std::ostream &dump(std::ostream &out, int ind) override {
239    return ExprAST::dump(out << Name, ind);
240  }
241  Value *Codegen() override;
242};
243
244/// UnaryExprAST - Expression class for a unary operator.
245class UnaryExprAST : public ExprAST {
246  char Opcode;
247  ExprAST *Operand;
248
249public:
250  UnaryExprAST(char opcode, ExprAST *operand)
251      : Opcode(opcode), Operand(operand) {}
252  std::ostream &dump(std::ostream &out, int ind) override {
253    ExprAST::dump(out << "unary" << Opcode, ind);
254    Operand->dump(out, ind + 1);
255    return out;
256  }
257  Value *Codegen() override;
258};
259
260/// BinaryExprAST - Expression class for a binary operator.
261class BinaryExprAST : public ExprAST {
262  char Op;
263  ExprAST *LHS, *RHS;
264
265public:
266  BinaryExprAST(SourceLocation Loc, char op, ExprAST *lhs, ExprAST *rhs)
267      : ExprAST(Loc), Op(op), LHS(lhs), RHS(rhs) {}
268  std::ostream &dump(std::ostream &out, int ind) override {
269    ExprAST::dump(out << "binary" << Op, ind);
270    LHS->dump(indent(out, ind) << "LHS:", ind + 1);
271    RHS->dump(indent(out, ind) << "RHS:", ind + 1);
272    return out;
273  }
274  Value *Codegen() override;
275};
276
277/// CallExprAST - Expression class for function calls.
278class CallExprAST : public ExprAST {
279  std::string Callee;
280  std::vector<ExprAST *> Args;
281
282public:
283  CallExprAST(SourceLocation Loc, const std::string &callee,
284              std::vector<ExprAST *> &args)
285      : ExprAST(Loc), Callee(callee), Args(args) {}
286  std::ostream &dump(std::ostream &out, int ind) override {
287    ExprAST::dump(out << "call " << Callee, ind);
288    for (ExprAST *Arg : Args)
289      Arg->dump(indent(out, ind + 1), ind + 1);
290    return out;
291  }
292  Value *Codegen() override;
293};
294
295/// IfExprAST - Expression class for if/then/else.
296class IfExprAST : public ExprAST {
297  ExprAST *Cond, *Then, *Else;
298
299public:
300  IfExprAST(SourceLocation Loc, ExprAST *cond, ExprAST *then, ExprAST *_else)
301      : ExprAST(Loc), Cond(cond), Then(then), Else(_else) {}
302  std::ostream &dump(std::ostream &out, int ind) override {
303    ExprAST::dump(out << "if", ind);
304    Cond->dump(indent(out, ind) << "Cond:", ind + 1);
305    Then->dump(indent(out, ind) << "Then:", ind + 1);
306    Else->dump(indent(out, ind) << "Else:", ind + 1);
307    return out;
308  }
309  Value *Codegen() override;
310};
311
312/// ForExprAST - Expression class for for/in.
313class ForExprAST : public ExprAST {
314  std::string VarName;
315  ExprAST *Start, *End, *Step, *Body;
316
317public:
318  ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
319             ExprAST *step, ExprAST *body)
320      : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
321  std::ostream &dump(std::ostream &out, int ind) override {
322    ExprAST::dump(out << "for", ind);
323    Start->dump(indent(out, ind) << "Cond:", ind + 1);
324    End->dump(indent(out, ind) << "End:", ind + 1);
325    Step->dump(indent(out, ind) << "Step:", ind + 1);
326    Body->dump(indent(out, ind) << "Body:", ind + 1);
327    return out;
328  }
329  Value *Codegen() override;
330};
331
332/// VarExprAST - Expression class for var/in
333class VarExprAST : public ExprAST {
334  std::vector<std::pair<std::string, ExprAST *> > VarNames;
335  ExprAST *Body;
336
337public:
338  VarExprAST(const std::vector<std::pair<std::string, ExprAST *> > &varnames,
339             ExprAST *body)
340      : VarNames(varnames), Body(body) {}
341
342  std::ostream &dump(std::ostream &out, int ind) override {
343    ExprAST::dump(out << "var", ind);
344    for (const auto &NamedVar : VarNames)
345      NamedVar.second->dump(indent(out, ind) << NamedVar.first << ':', ind + 1);
346    Body->dump(indent(out, ind) << "Body:", ind + 1);
347    return out;
348  }
349  Value *Codegen() override;
350};
351
352/// PrototypeAST - This class represents the "prototype" for a function,
353/// which captures its argument names as well as if it is an operator.
354class PrototypeAST {
355  std::string Name;
356  std::vector<std::string> Args;
357  bool isOperator;
358  unsigned Precedence; // Precedence if a binary op.
359  int Line;
360
361public:
362  PrototypeAST(SourceLocation Loc, const std::string &name,
363               const std::vector<std::string> &args, bool isoperator = false,
364               unsigned prec = 0)
365      : Name(name), Args(args), isOperator(isoperator), Precedence(prec),
366        Line(Loc.Line) {}
367
368  bool isUnaryOp() const { return isOperator && Args.size() == 1; }
369  bool isBinaryOp() const { return isOperator && Args.size() == 2; }
370
371  char getOperatorName() const {
372    assert(isUnaryOp() || isBinaryOp());
373    return Name[Name.size() - 1];
374  }
375
376  unsigned getBinaryPrecedence() const { return Precedence; }
377
378  Function *Codegen();
379
380  void CreateArgumentAllocas(Function *F);
381  const std::vector<std::string> &getArgs() const { return Args; }
382};
383
384/// FunctionAST - This class represents a function definition itself.
385class FunctionAST {
386  PrototypeAST *Proto;
387  ExprAST *Body;
388
389public:
390  FunctionAST(PrototypeAST *proto, ExprAST *body) : Proto(proto), Body(body) {}
391
392  std::ostream &dump(std::ostream &out, int ind) {
393    indent(out, ind) << "FunctionAST\n";
394    ++ind;
395    indent(out, ind) << "Body:";
396    return Body ? Body->dump(out, ind) : out << "null\n";
397  }
398
399  Function *Codegen();
400};
401} // end anonymous namespace
402
403//===----------------------------------------------------------------------===//
404// Parser
405//===----------------------------------------------------------------------===//
406
407/// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
408/// token the parser is looking at.  getNextToken reads another token from the
409/// lexer and updates CurTok with its results.
410static int CurTok;
411static int getNextToken() { return CurTok = gettok(); }
412
413/// BinopPrecedence - This holds the precedence for each binary operator that is
414/// defined.
415static std::map<char, int> BinopPrecedence;
416
417/// GetTokPrecedence - Get the precedence of the pending binary operator token.
418static int GetTokPrecedence() {
419  if (!isascii(CurTok))
420    return -1;
421
422  // Make sure it's a declared binop.
423  int TokPrec = BinopPrecedence[CurTok];
424  if (TokPrec <= 0)
425    return -1;
426  return TokPrec;
427}
428
429/// Error* - These are little helper functions for error handling.
430ExprAST *Error(const char *Str) {
431  fprintf(stderr, "Error: %s\n", Str);
432  return 0;
433}
434PrototypeAST *ErrorP(const char *Str) {
435  Error(Str);
436  return 0;
437}
438FunctionAST *ErrorF(const char *Str) {
439  Error(Str);
440  return 0;
441}
442
443static ExprAST *ParseExpression();
444
445/// identifierexpr
446///   ::= identifier
447///   ::= identifier '(' expression* ')'
448static ExprAST *ParseIdentifierExpr() {
449  std::string IdName = IdentifierStr;
450
451  SourceLocation LitLoc = CurLoc;
452
453  getNextToken(); // eat identifier.
454
455  if (CurTok != '(') // Simple variable ref.
456    return new VariableExprAST(LitLoc, IdName);
457
458  // Call.
459  getNextToken(); // eat (
460  std::vector<ExprAST *> Args;
461  if (CurTok != ')') {
462    while (1) {
463      ExprAST *Arg = ParseExpression();
464      if (!Arg)
465        return 0;
466      Args.push_back(Arg);
467
468      if (CurTok == ')')
469        break;
470
471      if (CurTok != ',')
472        return Error("Expected ')' or ',' in argument list");
473      getNextToken();
474    }
475  }
476
477  // Eat the ')'.
478  getNextToken();
479
480  return new CallExprAST(LitLoc, IdName, Args);
481}
482
483/// numberexpr ::= number
484static ExprAST *ParseNumberExpr() {
485  ExprAST *Result = new NumberExprAST(NumVal);
486  getNextToken(); // consume the number
487  return Result;
488}
489
490/// parenexpr ::= '(' expression ')'
491static ExprAST *ParseParenExpr() {
492  getNextToken(); // eat (.
493  ExprAST *V = ParseExpression();
494  if (!V)
495    return 0;
496
497  if (CurTok != ')')
498    return Error("expected ')'");
499  getNextToken(); // eat ).
500  return V;
501}
502
503/// ifexpr ::= 'if' expression 'then' expression 'else' expression
504static ExprAST *ParseIfExpr() {
505  SourceLocation IfLoc = CurLoc;
506
507  getNextToken(); // eat the if.
508
509  // condition.
510  ExprAST *Cond = ParseExpression();
511  if (!Cond)
512    return 0;
513
514  if (CurTok != tok_then)
515    return Error("expected then");
516  getNextToken(); // eat the then
517
518  ExprAST *Then = ParseExpression();
519  if (Then == 0)
520    return 0;
521
522  if (CurTok != tok_else)
523    return Error("expected else");
524
525  getNextToken();
526
527  ExprAST *Else = ParseExpression();
528  if (!Else)
529    return 0;
530
531  return new IfExprAST(IfLoc, Cond, Then, Else);
532}
533
534/// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
535static ExprAST *ParseForExpr() {
536  getNextToken(); // eat the for.
537
538  if (CurTok != tok_identifier)
539    return Error("expected identifier after for");
540
541  std::string IdName = IdentifierStr;
542  getNextToken(); // eat identifier.
543
544  if (CurTok != '=')
545    return Error("expected '=' after for");
546  getNextToken(); // eat '='.
547
548  ExprAST *Start = ParseExpression();
549  if (Start == 0)
550    return 0;
551  if (CurTok != ',')
552    return Error("expected ',' after for start value");
553  getNextToken();
554
555  ExprAST *End = ParseExpression();
556  if (End == 0)
557    return 0;
558
559  // The step value is optional.
560  ExprAST *Step = 0;
561  if (CurTok == ',') {
562    getNextToken();
563    Step = ParseExpression();
564    if (Step == 0)
565      return 0;
566  }
567
568  if (CurTok != tok_in)
569    return Error("expected 'in' after for");
570  getNextToken(); // eat 'in'.
571
572  ExprAST *Body = ParseExpression();
573  if (Body == 0)
574    return 0;
575
576  return new ForExprAST(IdName, Start, End, Step, Body);
577}
578
579/// varexpr ::= 'var' identifier ('=' expression)?
580//                    (',' identifier ('=' expression)?)* 'in' expression
581static ExprAST *ParseVarExpr() {
582  getNextToken(); // eat the var.
583
584  std::vector<std::pair<std::string, ExprAST *> > VarNames;
585
586  // At least one variable name is required.
587  if (CurTok != tok_identifier)
588    return Error("expected identifier after var");
589
590  while (1) {
591    std::string Name = IdentifierStr;
592    getNextToken(); // eat identifier.
593
594    // Read the optional initializer.
595    ExprAST *Init = 0;
596    if (CurTok == '=') {
597      getNextToken(); // eat the '='.
598
599      Init = ParseExpression();
600      if (Init == 0)
601        return 0;
602    }
603
604    VarNames.push_back(std::make_pair(Name, Init));
605
606    // End of var list, exit loop.
607    if (CurTok != ',')
608      break;
609    getNextToken(); // eat the ','.
610
611    if (CurTok != tok_identifier)
612      return Error("expected identifier list after var");
613  }
614
615  // At this point, we have to have 'in'.
616  if (CurTok != tok_in)
617    return Error("expected 'in' keyword after 'var'");
618  getNextToken(); // eat 'in'.
619
620  ExprAST *Body = ParseExpression();
621  if (Body == 0)
622    return 0;
623
624  return new VarExprAST(VarNames, Body);
625}
626
627/// primary
628///   ::= identifierexpr
629///   ::= numberexpr
630///   ::= parenexpr
631///   ::= ifexpr
632///   ::= forexpr
633///   ::= varexpr
634static ExprAST *ParsePrimary() {
635  switch (CurTok) {
636  default:
637    return Error("unknown token when expecting an expression");
638  case tok_identifier:
639    return ParseIdentifierExpr();
640  case tok_number:
641    return ParseNumberExpr();
642  case '(':
643    return ParseParenExpr();
644  case tok_if:
645    return ParseIfExpr();
646  case tok_for:
647    return ParseForExpr();
648  case tok_var:
649    return ParseVarExpr();
650  }
651}
652
653/// unary
654///   ::= primary
655///   ::= '!' unary
656static ExprAST *ParseUnary() {
657  // If the current token is not an operator, it must be a primary expr.
658  if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
659    return ParsePrimary();
660
661  // If this is a unary operator, read it.
662  int Opc = CurTok;
663  getNextToken();
664  if (ExprAST *Operand = ParseUnary())
665    return new UnaryExprAST(Opc, Operand);
666  return 0;
667}
668
669/// binoprhs
670///   ::= ('+' unary)*
671static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
672  // If this is a binop, find its precedence.
673  while (1) {
674    int TokPrec = GetTokPrecedence();
675
676    // If this is a binop that binds at least as tightly as the current binop,
677    // consume it, otherwise we are done.
678    if (TokPrec < ExprPrec)
679      return LHS;
680
681    // Okay, we know this is a binop.
682    int BinOp = CurTok;
683    SourceLocation BinLoc = CurLoc;
684    getNextToken(); // eat binop
685
686    // Parse the unary expression after the binary operator.
687    ExprAST *RHS = ParseUnary();
688    if (!RHS)
689      return 0;
690
691    // If BinOp binds less tightly with RHS than the operator after RHS, let
692    // the pending operator take RHS as its LHS.
693    int NextPrec = GetTokPrecedence();
694    if (TokPrec < NextPrec) {
695      RHS = ParseBinOpRHS(TokPrec + 1, RHS);
696      if (RHS == 0)
697        return 0;
698    }
699
700    // Merge LHS/RHS.
701    LHS = new BinaryExprAST(BinLoc, BinOp, LHS, RHS);
702  }
703}
704
705/// expression
706///   ::= unary binoprhs
707///
708static ExprAST *ParseExpression() {
709  ExprAST *LHS = ParseUnary();
710  if (!LHS)
711    return 0;
712
713  return ParseBinOpRHS(0, LHS);
714}
715
716/// prototype
717///   ::= id '(' id* ')'
718///   ::= binary LETTER number? (id, id)
719///   ::= unary LETTER (id)
720static PrototypeAST *ParsePrototype() {
721  std::string FnName;
722
723  SourceLocation FnLoc = CurLoc;
724
725  unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
726  unsigned BinaryPrecedence = 30;
727
728  switch (CurTok) {
729  default:
730    return ErrorP("Expected function name in prototype");
731  case tok_identifier:
732    FnName = IdentifierStr;
733    Kind = 0;
734    getNextToken();
735    break;
736  case tok_unary:
737    getNextToken();
738    if (!isascii(CurTok))
739      return ErrorP("Expected unary operator");
740    FnName = "unary";
741    FnName += (char)CurTok;
742    Kind = 1;
743    getNextToken();
744    break;
745  case tok_binary:
746    getNextToken();
747    if (!isascii(CurTok))
748      return ErrorP("Expected binary operator");
749    FnName = "binary";
750    FnName += (char)CurTok;
751    Kind = 2;
752    getNextToken();
753
754    // Read the precedence if present.
755    if (CurTok == tok_number) {
756      if (NumVal < 1 || NumVal > 100)
757        return ErrorP("Invalid precedecnce: must be 1..100");
758      BinaryPrecedence = (unsigned)NumVal;
759      getNextToken();
760    }
761    break;
762  }
763
764  if (CurTok != '(')
765    return ErrorP("Expected '(' in prototype");
766
767  std::vector<std::string> ArgNames;
768  while (getNextToken() == tok_identifier)
769    ArgNames.push_back(IdentifierStr);
770  if (CurTok != ')')
771    return ErrorP("Expected ')' in prototype");
772
773  // success.
774  getNextToken(); // eat ')'.
775
776  // Verify right number of names for operator.
777  if (Kind && ArgNames.size() != Kind)
778    return ErrorP("Invalid number of operands for operator");
779
780  return new PrototypeAST(FnLoc, FnName, ArgNames, Kind != 0, BinaryPrecedence);
781}
782
783/// definition ::= 'def' prototype expression
784static FunctionAST *ParseDefinition() {
785  getNextToken(); // eat def.
786  PrototypeAST *Proto = ParsePrototype();
787  if (Proto == 0)
788    return 0;
789
790  if (ExprAST *E = ParseExpression())
791    return new FunctionAST(Proto, E);
792  return 0;
793}
794
795/// toplevelexpr ::= expression
796static FunctionAST *ParseTopLevelExpr() {
797  SourceLocation FnLoc = CurLoc;
798  if (ExprAST *E = ParseExpression()) {
799    // Make an anonymous proto.
800    PrototypeAST *Proto =
801        new PrototypeAST(FnLoc, "main", std::vector<std::string>());
802    return new FunctionAST(Proto, E);
803  }
804  return 0;
805}
806
807/// external ::= 'extern' prototype
808static PrototypeAST *ParseExtern() {
809  getNextToken(); // eat extern.
810  return ParsePrototype();
811}
812
813//===----------------------------------------------------------------------===//
814// Debug Info Support
815//===----------------------------------------------------------------------===//
816
817static DIBuilder *DBuilder;
818
819DIType DebugInfo::getDoubleTy() {
820  if (DblTy)
821    return DblTy;
822
823  DblTy = DBuilder->createBasicType("double", 64, 64, dwarf::DW_ATE_float);
824  return DblTy;
825}
826
827void DebugInfo::emitLocation(ExprAST *AST) {
828  if (!AST)
829    return Builder.SetCurrentDebugLocation(DebugLoc());
830  MDScope *Scope;
831  if (LexicalBlocks.empty())
832    Scope = TheCU;
833  else
834    Scope = *LexicalBlocks.back();
835  Builder.SetCurrentDebugLocation(
836      DebugLoc::get(AST->getLine(), AST->getCol(), Scope));
837}
838
839static MDSubroutineType *CreateFunctionType(unsigned NumArgs, DIFile Unit) {
840  SmallVector<Metadata *, 8> EltTys;
841  DIType DblTy = KSDbgInfo.getDoubleTy();
842
843  // Add the result type.
844  EltTys.push_back(DblTy);
845
846  for (unsigned i = 0, e = NumArgs; i != e; ++i)
847    EltTys.push_back(DblTy);
848
849  DITypeArray EltTypeArray = DBuilder->getOrCreateTypeArray(EltTys);
850  return DBuilder->createSubroutineType(Unit, EltTypeArray);
851}
852
853//===----------------------------------------------------------------------===//
854// Code Generation
855//===----------------------------------------------------------------------===//
856
857static Module *TheModule;
858static std::map<std::string, AllocaInst *> NamedValues;
859static legacy::FunctionPassManager *TheFPM;
860
861Value *ErrorV(const char *Str) {
862  Error(Str);
863  return 0;
864}
865
866/// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
867/// the function.  This is used for mutable variables etc.
868static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
869                                          const std::string &VarName) {
870  IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
871                   TheFunction->getEntryBlock().begin());
872  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
873                           VarName.c_str());
874}
875
876Value *NumberExprAST::Codegen() {
877  KSDbgInfo.emitLocation(this);
878  return ConstantFP::get(getGlobalContext(), APFloat(Val));
879}
880
881Value *VariableExprAST::Codegen() {
882  // Look this variable up in the function.
883  Value *V = NamedValues[Name];
884  if (V == 0)
885    return ErrorV("Unknown variable name");
886
887  KSDbgInfo.emitLocation(this);
888  // Load the value.
889  return Builder.CreateLoad(V, Name.c_str());
890}
891
892Value *UnaryExprAST::Codegen() {
893  Value *OperandV = Operand->Codegen();
894  if (OperandV == 0)
895    return 0;
896
897  Function *F = TheModule->getFunction(std::string("unary") + Opcode);
898  if (F == 0)
899    return ErrorV("Unknown unary operator");
900
901  KSDbgInfo.emitLocation(this);
902  return Builder.CreateCall(F, OperandV, "unop");
903}
904
905Value *BinaryExprAST::Codegen() {
906  KSDbgInfo.emitLocation(this);
907
908  // Special case '=' because we don't want to emit the LHS as an expression.
909  if (Op == '=') {
910    // Assignment requires the LHS to be an identifier.
911    VariableExprAST *LHSE = dynamic_cast<VariableExprAST *>(LHS);
912    if (!LHSE)
913      return ErrorV("destination of '=' must be a variable");
914    // Codegen the RHS.
915    Value *Val = RHS->Codegen();
916    if (Val == 0)
917      return 0;
918
919    // Look up the name.
920    Value *Variable = NamedValues[LHSE->getName()];
921    if (Variable == 0)
922      return ErrorV("Unknown variable name");
923
924    Builder.CreateStore(Val, Variable);
925    return Val;
926  }
927
928  Value *L = LHS->Codegen();
929  Value *R = RHS->Codegen();
930  if (L == 0 || R == 0)
931    return 0;
932
933  switch (Op) {
934  case '+':
935    return Builder.CreateFAdd(L, R, "addtmp");
936  case '-':
937    return Builder.CreateFSub(L, R, "subtmp");
938  case '*':
939    return Builder.CreateFMul(L, R, "multmp");
940  case '<':
941    L = Builder.CreateFCmpULT(L, R, "cmptmp");
942    // Convert bool 0/1 to double 0.0 or 1.0
943    return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
944                                "booltmp");
945  default:
946    break;
947  }
948
949  // If it wasn't a builtin binary operator, it must be a user defined one. Emit
950  // a call to it.
951  Function *F = TheModule->getFunction(std::string("binary") + Op);
952  assert(F && "binary operator not found!");
953
954  Value *Ops[] = { L, R };
955  return Builder.CreateCall(F, Ops, "binop");
956}
957
958Value *CallExprAST::Codegen() {
959  KSDbgInfo.emitLocation(this);
960
961  // Look up the name in the global module table.
962  Function *CalleeF = TheModule->getFunction(Callee);
963  if (CalleeF == 0)
964    return ErrorV("Unknown function referenced");
965
966  // If argument mismatch error.
967  if (CalleeF->arg_size() != Args.size())
968    return ErrorV("Incorrect # arguments passed");
969
970  std::vector<Value *> ArgsV;
971  for (unsigned i = 0, e = Args.size(); i != e; ++i) {
972    ArgsV.push_back(Args[i]->Codegen());
973    if (ArgsV.back() == 0)
974      return 0;
975  }
976
977  return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
978}
979
980Value *IfExprAST::Codegen() {
981  KSDbgInfo.emitLocation(this);
982
983  Value *CondV = Cond->Codegen();
984  if (CondV == 0)
985    return 0;
986
987  // Convert condition to a bool by comparing equal to 0.0.
988  CondV = Builder.CreateFCmpONE(
989      CondV, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "ifcond");
990
991  Function *TheFunction = Builder.GetInsertBlock()->getParent();
992
993  // Create blocks for the then and else cases.  Insert the 'then' block at the
994  // end of the function.
995  BasicBlock *ThenBB =
996      BasicBlock::Create(getGlobalContext(), "then", TheFunction);
997  BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
998  BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
999
1000  Builder.CreateCondBr(CondV, ThenBB, ElseBB);
1001
1002  // Emit then value.
1003  Builder.SetInsertPoint(ThenBB);
1004
1005  Value *ThenV = Then->Codegen();
1006  if (ThenV == 0)
1007    return 0;
1008
1009  Builder.CreateBr(MergeBB);
1010  // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
1011  ThenBB = Builder.GetInsertBlock();
1012
1013  // Emit else block.
1014  TheFunction->getBasicBlockList().push_back(ElseBB);
1015  Builder.SetInsertPoint(ElseBB);
1016
1017  Value *ElseV = Else->Codegen();
1018  if (ElseV == 0)
1019    return 0;
1020
1021  Builder.CreateBr(MergeBB);
1022  // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
1023  ElseBB = Builder.GetInsertBlock();
1024
1025  // Emit merge block.
1026  TheFunction->getBasicBlockList().push_back(MergeBB);
1027  Builder.SetInsertPoint(MergeBB);
1028  PHINode *PN =
1029      Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, "iftmp");
1030
1031  PN->addIncoming(ThenV, ThenBB);
1032  PN->addIncoming(ElseV, ElseBB);
1033  return PN;
1034}
1035
1036Value *ForExprAST::Codegen() {
1037  // Output this as:
1038  //   var = alloca double
1039  //   ...
1040  //   start = startexpr
1041  //   store start -> var
1042  //   goto loop
1043  // loop:
1044  //   ...
1045  //   bodyexpr
1046  //   ...
1047  // loopend:
1048  //   step = stepexpr
1049  //   endcond = endexpr
1050  //
1051  //   curvar = load var
1052  //   nextvar = curvar + step
1053  //   store nextvar -> var
1054  //   br endcond, loop, endloop
1055  // outloop:
1056
1057  Function *TheFunction = Builder.GetInsertBlock()->getParent();
1058
1059  // Create an alloca for the variable in the entry block.
1060  AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
1061
1062  KSDbgInfo.emitLocation(this);
1063
1064  // Emit the start code first, without 'variable' in scope.
1065  Value *StartVal = Start->Codegen();
1066  if (StartVal == 0)
1067    return 0;
1068
1069  // Store the value into the alloca.
1070  Builder.CreateStore(StartVal, Alloca);
1071
1072  // Make the new basic block for the loop header, inserting after current
1073  // block.
1074  BasicBlock *LoopBB =
1075      BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
1076
1077  // Insert an explicit fall through from the current block to the LoopBB.
1078  Builder.CreateBr(LoopBB);
1079
1080  // Start insertion in LoopBB.
1081  Builder.SetInsertPoint(LoopBB);
1082
1083  // Within the loop, the variable is defined equal to the PHI node.  If it
1084  // shadows an existing variable, we have to restore it, so save it now.
1085  AllocaInst *OldVal = NamedValues[VarName];
1086  NamedValues[VarName] = Alloca;
1087
1088  // Emit the body of the loop.  This, like any other expr, can change the
1089  // current BB.  Note that we ignore the value computed by the body, but don't
1090  // allow an error.
1091  if (Body->Codegen() == 0)
1092    return 0;
1093
1094  // Emit the step value.
1095  Value *StepVal;
1096  if (Step) {
1097    StepVal = Step->Codegen();
1098    if (StepVal == 0)
1099      return 0;
1100  } else {
1101    // If not specified, use 1.0.
1102    StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
1103  }
1104
1105  // Compute the end condition.
1106  Value *EndCond = End->Codegen();
1107  if (EndCond == 0)
1108    return EndCond;
1109
1110  // Reload, increment, and restore the alloca.  This handles the case where
1111  // the body of the loop mutates the variable.
1112  Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
1113  Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
1114  Builder.CreateStore(NextVar, Alloca);
1115
1116  // Convert condition to a bool by comparing equal to 0.0.
1117  EndCond = Builder.CreateFCmpONE(
1118      EndCond, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "loopcond");
1119
1120  // Create the "after loop" block and insert it.
1121  BasicBlock *AfterBB =
1122      BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
1123
1124  // Insert the conditional branch into the end of LoopEndBB.
1125  Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
1126
1127  // Any new code will be inserted in AfterBB.
1128  Builder.SetInsertPoint(AfterBB);
1129
1130  // Restore the unshadowed variable.
1131  if (OldVal)
1132    NamedValues[VarName] = OldVal;
1133  else
1134    NamedValues.erase(VarName);
1135
1136  // for expr always returns 0.0.
1137  return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
1138}
1139
1140Value *VarExprAST::Codegen() {
1141  std::vector<AllocaInst *> OldBindings;
1142
1143  Function *TheFunction = Builder.GetInsertBlock()->getParent();
1144
1145  // Register all variables and emit their initializer.
1146  for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
1147    const std::string &VarName = VarNames[i].first;
1148    ExprAST *Init = VarNames[i].second;
1149
1150    // Emit the initializer before adding the variable to scope, this prevents
1151    // the initializer from referencing the variable itself, and permits stuff
1152    // like this:
1153    //  var a = 1 in
1154    //    var a = a in ...   # refers to outer 'a'.
1155    Value *InitVal;
1156    if (Init) {
1157      InitVal = Init->Codegen();
1158      if (InitVal == 0)
1159        return 0;
1160    } else { // If not specified, use 0.0.
1161      InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
1162    }
1163
1164    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
1165    Builder.CreateStore(InitVal, Alloca);
1166
1167    // Remember the old variable binding so that we can restore the binding when
1168    // we unrecurse.
1169    OldBindings.push_back(NamedValues[VarName]);
1170
1171    // Remember this binding.
1172    NamedValues[VarName] = Alloca;
1173  }
1174
1175  KSDbgInfo.emitLocation(this);
1176
1177  // Codegen the body, now that all vars are in scope.
1178  Value *BodyVal = Body->Codegen();
1179  if (BodyVal == 0)
1180    return 0;
1181
1182  // Pop all our variables from scope.
1183  for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
1184    NamedValues[VarNames[i].first] = OldBindings[i];
1185
1186  // Return the body computation.
1187  return BodyVal;
1188}
1189
1190Function *PrototypeAST::Codegen() {
1191  // Make the function type:  double(double,double) etc.
1192  std::vector<Type *> Doubles(Args.size(),
1193                              Type::getDoubleTy(getGlobalContext()));
1194  FunctionType *FT =
1195      FunctionType::get(Type::getDoubleTy(getGlobalContext()), Doubles, false);
1196
1197  Function *F =
1198      Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
1199
1200  // If F conflicted, there was already something named 'Name'.  If it has a
1201  // body, don't allow redefinition or reextern.
1202  if (F->getName() != Name) {
1203    // Delete the one we just made and get the existing one.
1204    F->eraseFromParent();
1205    F = TheModule->getFunction(Name);
1206
1207    // If F already has a body, reject this.
1208    if (!F->empty()) {
1209      ErrorF("redefinition of function");
1210      return 0;
1211    }
1212
1213    // If F took a different number of args, reject.
1214    if (F->arg_size() != Args.size()) {
1215      ErrorF("redefinition of function with different # args");
1216      return 0;
1217    }
1218  }
1219
1220  // Set names for all arguments.
1221  unsigned Idx = 0;
1222  for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
1223       ++AI, ++Idx)
1224    AI->setName(Args[Idx]);
1225
1226  // Create a subprogram DIE for this function.
1227  DIFile Unit = DBuilder->createFile(KSDbgInfo.TheCU->getFilename(),
1228                                     KSDbgInfo.TheCU->getDirectory());
1229  MDScope *FContext = Unit;
1230  unsigned LineNo = Line;
1231  unsigned ScopeLine = Line;
1232  DISubprogram SP = DBuilder->createFunction(
1233      FContext, Name, StringRef(), Unit, LineNo,
1234      CreateFunctionType(Args.size(), Unit), false /* internal linkage */,
1235      true /* definition */, ScopeLine, DebugNode::FlagPrototyped, false, F);
1236
1237  KSDbgInfo.FnScopeMap[this] = SP;
1238  return F;
1239}
1240
1241/// CreateArgumentAllocas - Create an alloca for each argument and register the
1242/// argument in the symbol table so that references to it will succeed.
1243void PrototypeAST::CreateArgumentAllocas(Function *F) {
1244  Function::arg_iterator AI = F->arg_begin();
1245  for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
1246    // Create an alloca for this variable.
1247    AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
1248
1249    // Create a debug descriptor for the variable.
1250    DIScope *Scope = KSDbgInfo.LexicalBlocks.back();
1251    DIFile Unit = DBuilder->createFile(KSDbgInfo.TheCU->getFilename(),
1252                                       KSDbgInfo.TheCU->getDirectory());
1253    DIVariable D = DBuilder->createLocalVariable(dwarf::DW_TAG_arg_variable,
1254                                                 *Scope, Args[Idx], Unit, Line,
1255                                                 KSDbgInfo.getDoubleTy(), Idx);
1256
1257    DBuilder->insertDeclare(Alloca, D, DBuilder->createExpression(),
1258                            DebugLoc::get(Line, 0, *Scope),
1259                            Builder.GetInsertBlock());
1260
1261    // Store the initial value into the alloca.
1262    Builder.CreateStore(AI, Alloca);
1263
1264    // Add arguments to variable symbol table.
1265    NamedValues[Args[Idx]] = Alloca;
1266  }
1267}
1268
1269Function *FunctionAST::Codegen() {
1270  NamedValues.clear();
1271
1272  Function *TheFunction = Proto->Codegen();
1273  if (TheFunction == 0)
1274    return 0;
1275
1276  // Push the current scope.
1277  KSDbgInfo.LexicalBlocks.push_back(&KSDbgInfo.FnScopeMap[Proto]);
1278
1279  // Unset the location for the prologue emission (leading instructions with no
1280  // location in a function are considered part of the prologue and the debugger
1281  // will run past them when breaking on a function)
1282  KSDbgInfo.emitLocation(nullptr);
1283
1284  // If this is an operator, install it.
1285  if (Proto->isBinaryOp())
1286    BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
1287
1288  // Create a new basic block to start insertion into.
1289  BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
1290  Builder.SetInsertPoint(BB);
1291
1292  // Add all arguments to the symbol table and create their allocas.
1293  Proto->CreateArgumentAllocas(TheFunction);
1294
1295  KSDbgInfo.emitLocation(Body);
1296
1297  if (Value *RetVal = Body->Codegen()) {
1298    // Finish off the function.
1299    Builder.CreateRet(RetVal);
1300
1301    // Pop off the lexical block for the function.
1302    KSDbgInfo.LexicalBlocks.pop_back();
1303
1304    // Validate the generated code, checking for consistency.
1305    verifyFunction(*TheFunction);
1306
1307    // Optimize the function.
1308    TheFPM->run(*TheFunction);
1309
1310    return TheFunction;
1311  }
1312
1313  // Error reading body, remove function.
1314  TheFunction->eraseFromParent();
1315
1316  if (Proto->isBinaryOp())
1317    BinopPrecedence.erase(Proto->getOperatorName());
1318
1319  // Pop off the lexical block for the function since we added it
1320  // unconditionally.
1321  KSDbgInfo.LexicalBlocks.pop_back();
1322
1323  return 0;
1324}
1325
1326//===----------------------------------------------------------------------===//
1327// Top-Level parsing and JIT Driver
1328//===----------------------------------------------------------------------===//
1329
1330static ExecutionEngine *TheExecutionEngine;
1331
1332static void HandleDefinition() {
1333  if (FunctionAST *F = ParseDefinition()) {
1334    if (!F->Codegen()) {
1335      fprintf(stderr, "Error reading function definition:");
1336    }
1337  } else {
1338    // Skip token for error recovery.
1339    getNextToken();
1340  }
1341}
1342
1343static void HandleExtern() {
1344  if (PrototypeAST *P = ParseExtern()) {
1345    if (!P->Codegen()) {
1346      fprintf(stderr, "Error reading extern");
1347    }
1348  } else {
1349    // Skip token for error recovery.
1350    getNextToken();
1351  }
1352}
1353
1354static void HandleTopLevelExpression() {
1355  // Evaluate a top-level expression into an anonymous function.
1356  if (FunctionAST *F = ParseTopLevelExpr()) {
1357    if (!F->Codegen()) {
1358      fprintf(stderr, "Error generating code for top level expr");
1359    }
1360  } else {
1361    // Skip token for error recovery.
1362    getNextToken();
1363  }
1364}
1365
1366/// top ::= definition | external | expression | ';'
1367static void MainLoop() {
1368  while (1) {
1369    switch (CurTok) {
1370    case tok_eof:
1371      return;
1372    case ';':
1373      getNextToken();
1374      break; // ignore top-level semicolons.
1375    case tok_def:
1376      HandleDefinition();
1377      break;
1378    case tok_extern:
1379      HandleExtern();
1380      break;
1381    default:
1382      HandleTopLevelExpression();
1383      break;
1384    }
1385  }
1386}
1387
1388//===----------------------------------------------------------------------===//
1389// "Library" functions that can be "extern'd" from user code.
1390//===----------------------------------------------------------------------===//
1391
1392/// putchard - putchar that takes a double and returns 0.
1393extern "C" double putchard(double X) {
1394  putchar((char)X);
1395  return 0;
1396}
1397
1398/// printd - printf that takes a double prints it as "%f\n", returning 0.
1399extern "C" double printd(double X) {
1400  printf("%f\n", X);
1401  return 0;
1402}
1403
1404//===----------------------------------------------------------------------===//
1405// Main driver code.
1406//===----------------------------------------------------------------------===//
1407
1408int main() {
1409  InitializeNativeTarget();
1410  InitializeNativeTargetAsmPrinter();
1411  InitializeNativeTargetAsmParser();
1412  LLVMContext &Context = getGlobalContext();
1413
1414  // Install standard binary operators.
1415  // 1 is lowest precedence.
1416  BinopPrecedence['='] = 2;
1417  BinopPrecedence['<'] = 10;
1418  BinopPrecedence['+'] = 20;
1419  BinopPrecedence['-'] = 20;
1420  BinopPrecedence['*'] = 40; // highest.
1421
1422  // Prime the first token.
1423  getNextToken();
1424
1425  // Make the module, which holds all the code.
1426  std::unique_ptr<Module> Owner = make_unique<Module>("my cool jit", Context);
1427  TheModule = Owner.get();
1428
1429  // Add the current debug info version into the module.
1430  TheModule->addModuleFlag(Module::Warning, "Debug Info Version",
1431                           DEBUG_METADATA_VERSION);
1432
1433  // Darwin only supports dwarf2.
1434  if (Triple(sys::getProcessTriple()).isOSDarwin())
1435    TheModule->addModuleFlag(llvm::Module::Warning, "Dwarf Version", 2);
1436
1437  // Construct the DIBuilder, we do this here because we need the module.
1438  DBuilder = new DIBuilder(*TheModule);
1439
1440  // Create the compile unit for the module.
1441  // Currently down as "fib.ks" as a filename since we're redirecting stdin
1442  // but we'd like actual source locations.
1443  KSDbgInfo.TheCU = DBuilder->createCompileUnit(
1444      dwarf::DW_LANG_C, "fib.ks", ".", "Kaleidoscope Compiler", 0, "", 0);
1445
1446  // Create the JIT.  This takes ownership of the module.
1447  std::string ErrStr;
1448  TheExecutionEngine =
1449      EngineBuilder(std::move(Owner))
1450          .setErrorStr(&ErrStr)
1451          .setMCJITMemoryManager(llvm::make_unique<SectionMemoryManager>())
1452          .create();
1453  if (!TheExecutionEngine) {
1454    fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
1455    exit(1);
1456  }
1457
1458  legacy::FunctionPassManager OurFPM(TheModule);
1459
1460  // Set up the optimizer pipeline.  Start with registering info about how the
1461  // target lays out data structures.
1462  TheModule->setDataLayout(*TheExecutionEngine->getDataLayout());
1463#if 0
1464  // Provide basic AliasAnalysis support for GVN.
1465  OurFPM.add(createBasicAliasAnalysisPass());
1466  // Promote allocas to registers.
1467  OurFPM.add(createPromoteMemoryToRegisterPass());
1468  // Do simple "peephole" optimizations and bit-twiddling optzns.
1469  OurFPM.add(createInstructionCombiningPass());
1470  // Reassociate expressions.
1471  OurFPM.add(createReassociatePass());
1472  // Eliminate Common SubExpressions.
1473  OurFPM.add(createGVNPass());
1474  // Simplify the control flow graph (deleting unreachable blocks, etc).
1475  OurFPM.add(createCFGSimplificationPass());
1476  #endif
1477  OurFPM.doInitialization();
1478
1479  // Set the global so the code gen can use this.
1480  TheFPM = &OurFPM;
1481
1482  // Run the main "interpreter loop" now.
1483  MainLoop();
1484
1485  TheFPM = 0;
1486
1487  // Finalize the debug info.
1488  DBuilder->finalize();
1489
1490  // Print out all of the generated code.
1491  TheModule->dump();
1492
1493  return 0;
1494}
1495