1 #define MINIMAL_STDERR_OUTPUT
3 #include "llvm/Analysis/Passes.h"
4 #include "llvm/ExecutionEngine/ExecutionEngine.h"
5 #include "llvm/IR/DataLayout.h"
6 #include "llvm/IR/DerivedTypes.h"
7 #include "llvm/IR/IRBuilder.h"
8 #include "llvm/IR/LLVMContext.h"
9 #include "llvm/IR/LegacyPassManager.h"
10 #include "llvm/IR/Module.h"
11 #include "llvm/IR/Verifier.h"
12 #include "llvm/Support/TargetSelect.h"
13 #include "llvm/Transforms/Scalar.h"
22 //===----------------------------------------------------------------------===//
24 //===----------------------------------------------------------------------===//
26 // The lexer returns tokens [0-255] if it is an unknown character, otherwise one
27 // of these for known things.
32 tok_def = -2, tok_extern = -3,
35 tok_identifier = -4, tok_number = -5,
38 tok_if = -6, tok_then = -7, tok_else = -8,
39 tok_for = -9, tok_in = -10,
42 tok_binary = -11, tok_unary = -12,
48 static std::string IdentifierStr; // Filled in if tok_identifier
49 static double NumVal; // Filled in if tok_number
51 /// gettok - Return the next token from standard input.
53 static int LastChar = ' ';
55 // Skip any whitespace.
56 while (isspace(LastChar))
59 if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
60 IdentifierStr = LastChar;
61 while (isalnum((LastChar = getchar())))
62 IdentifierStr += LastChar;
64 if (IdentifierStr == "def") return tok_def;
65 if (IdentifierStr == "extern") return tok_extern;
66 if (IdentifierStr == "if") return tok_if;
67 if (IdentifierStr == "then") return tok_then;
68 if (IdentifierStr == "else") return tok_else;
69 if (IdentifierStr == "for") return tok_for;
70 if (IdentifierStr == "in") return tok_in;
71 if (IdentifierStr == "binary") return tok_binary;
72 if (IdentifierStr == "unary") return tok_unary;
73 if (IdentifierStr == "var") return tok_var;
74 return tok_identifier;
77 if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
82 } while (isdigit(LastChar) || LastChar == '.');
84 NumVal = strtod(NumStr.c_str(), 0);
88 if (LastChar == '#') {
89 // Comment until end of line.
90 do LastChar = getchar();
91 while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
97 // Check for end of file. Don't eat the EOF.
101 // Otherwise, just return the character as its ascii value.
102 int ThisChar = LastChar;
103 LastChar = getchar();
107 //===----------------------------------------------------------------------===//
108 // Abstract Syntax Tree (aka Parse Tree)
109 //===----------------------------------------------------------------------===//
111 /// ExprAST - Base class for all expression nodes.
114 virtual ~ExprAST() {}
115 virtual Value *Codegen() = 0;
118 /// NumberExprAST - Expression class for numeric literals like "1.0".
119 class NumberExprAST : public ExprAST {
122 NumberExprAST(double val) : Val(val) {}
123 virtual Value *Codegen();
126 /// VariableExprAST - Expression class for referencing a variable, like "a".
127 class VariableExprAST : public ExprAST {
130 VariableExprAST(const std::string &name) : Name(name) {}
131 const std::string &getName() const { return Name; }
132 virtual Value *Codegen();
135 /// UnaryExprAST - Expression class for a unary operator.
136 class UnaryExprAST : public ExprAST {
140 UnaryExprAST(char opcode, ExprAST *operand)
141 : Opcode(opcode), Operand(operand) {}
142 virtual Value *Codegen();
145 /// BinaryExprAST - Expression class for a binary operator.
146 class BinaryExprAST : public ExprAST {
150 BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
151 : Op(op), LHS(lhs), RHS(rhs) {}
152 virtual Value *Codegen();
155 /// CallExprAST - Expression class for function calls.
156 class CallExprAST : public ExprAST {
158 std::vector<ExprAST*> Args;
160 CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
161 : Callee(callee), Args(args) {}
162 virtual Value *Codegen();
165 /// IfExprAST - Expression class for if/then/else.
166 class IfExprAST : public ExprAST {
167 ExprAST *Cond, *Then, *Else;
169 IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
170 : Cond(cond), Then(then), Else(_else) {}
171 virtual Value *Codegen();
174 /// ForExprAST - Expression class for for/in.
175 class ForExprAST : public ExprAST {
177 ExprAST *Start, *End, *Step, *Body;
179 ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
180 ExprAST *step, ExprAST *body)
181 : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
182 virtual Value *Codegen();
185 /// VarExprAST - Expression class for var/in
186 class VarExprAST : public ExprAST {
187 std::vector<std::pair<std::string, ExprAST*> > VarNames;
190 VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
192 : VarNames(varnames), Body(body) {}
194 virtual Value *Codegen();
197 /// PrototypeAST - This class represents the "prototype" for a function,
198 /// which captures its argument names as well as if it is an operator.
201 std::vector<std::string> Args;
203 unsigned Precedence; // Precedence if a binary op.
205 PrototypeAST(const std::string &name, const std::vector<std::string> &args,
206 bool isoperator = false, unsigned prec = 0)
207 : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
209 bool isUnaryOp() const { return isOperator && Args.size() == 1; }
210 bool isBinaryOp() const { return isOperator && Args.size() == 2; }
212 char getOperatorName() const {
213 assert(isUnaryOp() || isBinaryOp());
214 return Name[Name.size()-1];
217 unsigned getBinaryPrecedence() const { return Precedence; }
221 void CreateArgumentAllocas(Function *F);
224 /// FunctionAST - This class represents a function definition itself.
229 FunctionAST(PrototypeAST *proto, ExprAST *body)
230 : Proto(proto), Body(body) {}
235 //===----------------------------------------------------------------------===//
237 //===----------------------------------------------------------------------===//
239 /// CurTok/getNextToken - Provide a simple token buffer. CurTok is the current
240 /// token the parser is looking at. getNextToken reads another token from the
241 /// lexer and updates CurTok with its results.
243 static int getNextToken() {
244 return CurTok = gettok();
247 /// BinopPrecedence - This holds the precedence for each binary operator that is
249 static std::map<char, int> BinopPrecedence;
251 /// GetTokPrecedence - Get the precedence of the pending binary operator token.
252 static int GetTokPrecedence() {
253 if (!isascii(CurTok))
256 // Make sure it's a declared binop.
257 int TokPrec = BinopPrecedence[CurTok];
258 if (TokPrec <= 0) return -1;
262 /// Error* - These are little helper functions for error handling.
263 ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
264 PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
265 FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
267 static ExprAST *ParseExpression();
271 /// ::= identifier '(' expression* ')'
272 static ExprAST *ParseIdentifierExpr() {
273 std::string IdName = IdentifierStr;
275 getNextToken(); // eat identifier.
277 if (CurTok != '(') // Simple variable ref.
278 return new VariableExprAST(IdName);
281 getNextToken(); // eat (
282 std::vector<ExprAST*> Args;
285 ExprAST *Arg = ParseExpression();
289 if (CurTok == ')') break;
292 return Error("Expected ')' or ',' in argument list");
300 return new CallExprAST(IdName, Args);
303 /// numberexpr ::= number
304 static ExprAST *ParseNumberExpr() {
305 ExprAST *Result = new NumberExprAST(NumVal);
306 getNextToken(); // consume the number
310 /// parenexpr ::= '(' expression ')'
311 static ExprAST *ParseParenExpr() {
312 getNextToken(); // eat (.
313 ExprAST *V = ParseExpression();
317 return Error("expected ')'");
318 getNextToken(); // eat ).
322 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
323 static ExprAST *ParseIfExpr() {
324 getNextToken(); // eat the if.
327 ExprAST *Cond = ParseExpression();
330 if (CurTok != tok_then)
331 return Error("expected then");
332 getNextToken(); // eat the then
334 ExprAST *Then = ParseExpression();
335 if (Then == 0) return 0;
337 if (CurTok != tok_else)
338 return Error("expected else");
342 ExprAST *Else = ParseExpression();
345 return new IfExprAST(Cond, Then, Else);
348 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
349 static ExprAST *ParseForExpr() {
350 getNextToken(); // eat the for.
352 if (CurTok != tok_identifier)
353 return Error("expected identifier after for");
355 std::string IdName = IdentifierStr;
356 getNextToken(); // eat identifier.
359 return Error("expected '=' after for");
360 getNextToken(); // eat '='.
363 ExprAST *Start = ParseExpression();
364 if (Start == 0) return 0;
366 return Error("expected ',' after for start value");
369 ExprAST *End = ParseExpression();
370 if (End == 0) return 0;
372 // The step value is optional.
376 Step = ParseExpression();
377 if (Step == 0) return 0;
380 if (CurTok != tok_in)
381 return Error("expected 'in' after for");
382 getNextToken(); // eat 'in'.
384 ExprAST *Body = ParseExpression();
385 if (Body == 0) return 0;
387 return new ForExprAST(IdName, Start, End, Step, Body);
390 /// varexpr ::= 'var' identifier ('=' expression)?
391 // (',' identifier ('=' expression)?)* 'in' expression
392 static ExprAST *ParseVarExpr() {
393 getNextToken(); // eat the var.
395 std::vector<std::pair<std::string, ExprAST*> > VarNames;
397 // At least one variable name is required.
398 if (CurTok != tok_identifier)
399 return Error("expected identifier after var");
402 std::string Name = IdentifierStr;
403 getNextToken(); // eat identifier.
405 // Read the optional initializer.
408 getNextToken(); // eat the '='.
410 Init = ParseExpression();
411 if (Init == 0) return 0;
414 VarNames.push_back(std::make_pair(Name, Init));
416 // End of var list, exit loop.
417 if (CurTok != ',') break;
418 getNextToken(); // eat the ','.
420 if (CurTok != tok_identifier)
421 return Error("expected identifier list after var");
424 // At this point, we have to have 'in'.
425 if (CurTok != tok_in)
426 return Error("expected 'in' keyword after 'var'");
427 getNextToken(); // eat 'in'.
429 ExprAST *Body = ParseExpression();
430 if (Body == 0) return 0;
432 return new VarExprAST(VarNames, Body);
436 /// ::= identifierexpr
442 static ExprAST *ParsePrimary() {
444 default: return Error("unknown token when expecting an expression");
445 case tok_identifier: return ParseIdentifierExpr();
446 case tok_number: return ParseNumberExpr();
447 case '(': return ParseParenExpr();
448 case tok_if: return ParseIfExpr();
449 case tok_for: return ParseForExpr();
450 case tok_var: return ParseVarExpr();
457 static ExprAST *ParseUnary() {
458 // If the current token is not an operator, it must be a primary expr.
459 if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
460 return ParsePrimary();
462 // If this is a unary operator, read it.
465 if (ExprAST *Operand = ParseUnary())
466 return new UnaryExprAST(Opc, Operand);
472 static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
473 // If this is a binop, find its precedence.
475 int TokPrec = GetTokPrecedence();
477 // If this is a binop that binds at least as tightly as the current binop,
478 // consume it, otherwise we are done.
479 if (TokPrec < ExprPrec)
482 // Okay, we know this is a binop.
484 getNextToken(); // eat binop
486 // Parse the unary expression after the binary operator.
487 ExprAST *RHS = ParseUnary();
490 // If BinOp binds less tightly with RHS than the operator after RHS, let
491 // the pending operator take RHS as its LHS.
492 int NextPrec = GetTokPrecedence();
493 if (TokPrec < NextPrec) {
494 RHS = ParseBinOpRHS(TokPrec+1, RHS);
495 if (RHS == 0) return 0;
499 LHS = new BinaryExprAST(BinOp, LHS, RHS);
504 /// ::= unary binoprhs
506 static ExprAST *ParseExpression() {
507 ExprAST *LHS = ParseUnary();
510 return ParseBinOpRHS(0, LHS);
514 /// ::= id '(' id* ')'
515 /// ::= binary LETTER number? (id, id)
516 /// ::= unary LETTER (id)
517 static PrototypeAST *ParsePrototype() {
520 unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
521 unsigned BinaryPrecedence = 30;
525 return ErrorP("Expected function name in prototype");
527 FnName = IdentifierStr;
533 if (!isascii(CurTok))
534 return ErrorP("Expected unary operator");
536 FnName += (char)CurTok;
542 if (!isascii(CurTok))
543 return ErrorP("Expected binary operator");
545 FnName += (char)CurTok;
549 // Read the precedence if present.
550 if (CurTok == tok_number) {
551 if (NumVal < 1 || NumVal > 100)
552 return ErrorP("Invalid precedecnce: must be 1..100");
553 BinaryPrecedence = (unsigned)NumVal;
560 return ErrorP("Expected '(' in prototype");
562 std::vector<std::string> ArgNames;
563 while (getNextToken() == tok_identifier)
564 ArgNames.push_back(IdentifierStr);
566 return ErrorP("Expected ')' in prototype");
569 getNextToken(); // eat ')'.
571 // Verify right number of names for operator.
572 if (Kind && ArgNames.size() != Kind)
573 return ErrorP("Invalid number of operands for operator");
575 return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
578 /// definition ::= 'def' prototype expression
579 static FunctionAST *ParseDefinition() {
580 getNextToken(); // eat def.
581 PrototypeAST *Proto = ParsePrototype();
582 if (Proto == 0) return 0;
584 if (ExprAST *E = ParseExpression())
585 return new FunctionAST(Proto, E);
589 /// toplevelexpr ::= expression
590 static FunctionAST *ParseTopLevelExpr() {
591 if (ExprAST *E = ParseExpression()) {
592 // Make an anonymous proto.
593 PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
594 return new FunctionAST(Proto, E);
599 /// external ::= 'extern' prototype
600 static PrototypeAST *ParseExtern() {
601 getNextToken(); // eat extern.
602 return ParsePrototype();
605 //===----------------------------------------------------------------------===//
607 //===----------------------------------------------------------------------===//
609 static Module *TheModule;
610 static FunctionPassManager *TheFPM;
611 static IRBuilder<> Builder(getGlobalContext());
612 static std::map<std::string, AllocaInst*> NamedValues;
614 Value *ErrorV(const char *Str) { Error(Str); return 0; }
616 /// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
617 /// the function. This is used for mutable variables etc.
618 static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
619 const std::string &VarName) {
620 IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
621 TheFunction->getEntryBlock().begin());
622 return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
626 Value *NumberExprAST::Codegen() {
627 return ConstantFP::get(getGlobalContext(), APFloat(Val));
630 Value *VariableExprAST::Codegen() {
631 // Look this variable up in the function.
632 Value *V = NamedValues[Name];
633 if (V == 0) return ErrorV("Unknown variable name");
636 return Builder.CreateLoad(V, Name.c_str());
639 Value *UnaryExprAST::Codegen() {
640 Value *OperandV = Operand->Codegen();
641 if (OperandV == 0) return 0;
643 Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("unary")+Opcode));
645 Function *F = TheModule->getFunction(std::string("unary")+Opcode);
648 return ErrorV("Unknown unary operator");
650 return Builder.CreateCall(F, OperandV, "unop");
653 Value *BinaryExprAST::Codegen() {
654 // Special case '=' because we don't want to emit the LHS as an expression.
656 // Assignment requires the LHS to be an identifier.
657 VariableExprAST *LHSE = dynamic_cast<VariableExprAST*>(LHS);
659 return ErrorV("destination of '=' must be a variable");
661 Value *Val = RHS->Codegen();
662 if (Val == 0) return 0;
665 Value *Variable = NamedValues[LHSE->getName()];
666 if (Variable == 0) return ErrorV("Unknown variable name");
668 Builder.CreateStore(Val, Variable);
672 Value *L = LHS->Codegen();
673 Value *R = RHS->Codegen();
674 if (L == 0 || R == 0) return 0;
677 case '+': return Builder.CreateFAdd(L, R, "addtmp");
678 case '-': return Builder.CreateFSub(L, R, "subtmp");
679 case '*': return Builder.CreateFMul(L, R, "multmp");
680 case '/': return Builder.CreateFDiv(L, R, "divtmp");
682 L = Builder.CreateFCmpULT(L, R, "cmptmp");
683 // Convert bool 0/1 to double 0.0 or 1.0
684 return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
689 // If it wasn't a builtin binary operator, it must be a user defined one. Emit
691 Function *F = TheModule->getFunction(std::string("binary")+Op);
692 assert(F && "binary operator not found!");
694 Value *Ops[] = { L, R };
695 return Builder.CreateCall(F, Ops, "binop");
698 Value *CallExprAST::Codegen() {
699 // Look up the name in the global module table.
700 Function *CalleeF = TheModule->getFunction(Callee);
703 sprintf(error_str, "Unknown function referenced %s", Callee.c_str());
704 return ErrorV(error_str);
707 // If argument mismatch error.
708 if (CalleeF->arg_size() != Args.size())
709 return ErrorV("Incorrect # arguments passed");
711 std::vector<Value*> ArgsV;
712 for (unsigned i = 0, e = Args.size(); i != e; ++i) {
713 ArgsV.push_back(Args[i]->Codegen());
714 if (ArgsV.back() == 0) return 0;
717 return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
720 Value *IfExprAST::Codegen() {
721 Value *CondV = Cond->Codegen();
722 if (CondV == 0) return 0;
724 // Convert condition to a bool by comparing equal to 0.0.
725 CondV = Builder.CreateFCmpONE(CondV,
726 ConstantFP::get(getGlobalContext(), APFloat(0.0)),
729 Function *TheFunction = Builder.GetInsertBlock()->getParent();
731 // Create blocks for the then and else cases. Insert the 'then' block at the
732 // end of the function.
733 BasicBlock *ThenBB = BasicBlock::Create(getGlobalContext(), "then", TheFunction);
734 BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
735 BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
737 Builder.CreateCondBr(CondV, ThenBB, ElseBB);
740 Builder.SetInsertPoint(ThenBB);
742 Value *ThenV = Then->Codegen();
743 if (ThenV == 0) return 0;
745 Builder.CreateBr(MergeBB);
746 // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
747 ThenBB = Builder.GetInsertBlock();
750 TheFunction->getBasicBlockList().push_back(ElseBB);
751 Builder.SetInsertPoint(ElseBB);
753 Value *ElseV = Else->Codegen();
754 if (ElseV == 0) return 0;
756 Builder.CreateBr(MergeBB);
757 // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
758 ElseBB = Builder.GetInsertBlock();
761 TheFunction->getBasicBlockList().push_back(MergeBB);
762 Builder.SetInsertPoint(MergeBB);
763 PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
766 PN->addIncoming(ThenV, ThenBB);
767 PN->addIncoming(ElseV, ElseBB);
771 Value *ForExprAST::Codegen() {
773 // var = alloca double
776 // store start -> var
787 // nextvar = curvar + step
788 // store nextvar -> var
789 // br endcond, loop, endloop
792 Function *TheFunction = Builder.GetInsertBlock()->getParent();
794 // Create an alloca for the variable in the entry block.
795 AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
797 // Emit the start code first, without 'variable' in scope.
798 Value *StartVal = Start->Codegen();
799 if (StartVal == 0) return 0;
801 // Store the value into the alloca.
802 Builder.CreateStore(StartVal, Alloca);
804 // Make the new basic block for the loop header, inserting after current
806 BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
808 // Insert an explicit fall through from the current block to the LoopBB.
809 Builder.CreateBr(LoopBB);
811 // Start insertion in LoopBB.
812 Builder.SetInsertPoint(LoopBB);
814 // Within the loop, the variable is defined equal to the PHI node. If it
815 // shadows an existing variable, we have to restore it, so save it now.
816 AllocaInst *OldVal = NamedValues[VarName];
817 NamedValues[VarName] = Alloca;
819 // Emit the body of the loop. This, like any other expr, can change the
820 // current BB. Note that we ignore the value computed by the body, but don't
822 if (Body->Codegen() == 0)
825 // Emit the step value.
828 StepVal = Step->Codegen();
829 if (StepVal == 0) return 0;
831 // If not specified, use 1.0.
832 StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
835 // Compute the end condition.
836 Value *EndCond = End->Codegen();
837 if (EndCond == 0) return EndCond;
839 // Reload, increment, and restore the alloca. This handles the case where
840 // the body of the loop mutates the variable.
841 Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
842 Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
843 Builder.CreateStore(NextVar, Alloca);
845 // Convert condition to a bool by comparing equal to 0.0.
846 EndCond = Builder.CreateFCmpONE(EndCond,
847 ConstantFP::get(getGlobalContext(), APFloat(0.0)),
850 // Create the "after loop" block and insert it.
851 BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
853 // Insert the conditional branch into the end of LoopEndBB.
854 Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
856 // Any new code will be inserted in AfterBB.
857 Builder.SetInsertPoint(AfterBB);
859 // Restore the unshadowed variable.
861 NamedValues[VarName] = OldVal;
863 NamedValues.erase(VarName);
866 // for expr always returns 0.0.
867 return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
870 Value *VarExprAST::Codegen() {
871 std::vector<AllocaInst *> OldBindings;
873 Function *TheFunction = Builder.GetInsertBlock()->getParent();
875 // Register all variables and emit their initializer.
876 for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
877 const std::string &VarName = VarNames[i].first;
878 ExprAST *Init = VarNames[i].second;
880 // Emit the initializer before adding the variable to scope, this prevents
881 // the initializer from referencing the variable itself, and permits stuff
884 // var a = a in ... # refers to outer 'a'.
887 InitVal = Init->Codegen();
888 if (InitVal == 0) return 0;
889 } else { // If not specified, use 0.0.
890 InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
893 AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
894 Builder.CreateStore(InitVal, Alloca);
896 // Remember the old variable binding so that we can restore the binding when
898 OldBindings.push_back(NamedValues[VarName]);
900 // Remember this binding.
901 NamedValues[VarName] = Alloca;
904 // Codegen the body, now that all vars are in scope.
905 Value *BodyVal = Body->Codegen();
906 if (BodyVal == 0) return 0;
908 // Pop all our variables from scope.
909 for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
910 NamedValues[VarNames[i].first] = OldBindings[i];
912 // Return the body computation.
916 Function *PrototypeAST::Codegen() {
917 // Make the function type: double(double,double) etc.
918 std::vector<Type*> Doubles(Args.size(),
919 Type::getDoubleTy(getGlobalContext()));
920 FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
923 Function *F = Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
924 // If F conflicted, there was already something named 'Name'. If it has a
925 // body, don't allow redefinition or reextern.
926 if (F->getName() != Name) {
927 // Delete the one we just made and get the existing one.
928 F->eraseFromParent();
929 F = TheModule->getFunction(Name);
930 // If F already has a body, reject this.
932 ErrorF("redefinition of function");
935 // If F took a different number of args, reject.
936 if (F->arg_size() != Args.size()) {
937 ErrorF("redefinition of function with different # args");
942 // Set names for all arguments.
944 for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
946 AI->setName(Args[Idx]);
951 /// CreateArgumentAllocas - Create an alloca for each argument and register the
952 /// argument in the symbol table so that references to it will succeed.
953 void PrototypeAST::CreateArgumentAllocas(Function *F) {
954 Function::arg_iterator AI = F->arg_begin();
955 for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
956 // Create an alloca for this variable.
957 AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
959 // Store the initial value into the alloca.
960 Builder.CreateStore(AI, Alloca);
962 // Add arguments to variable symbol table.
963 NamedValues[Args[Idx]] = Alloca;
967 Function *FunctionAST::Codegen() {
970 Function *TheFunction = Proto->Codegen();
971 if (TheFunction == 0)
974 // If this is an operator, install it.
975 if (Proto->isBinaryOp())
976 BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
978 // Create a new basic block to start insertion into.
979 BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
980 Builder.SetInsertPoint(BB);
982 // Add all arguments to the symbol table and create their allocas.
983 Proto->CreateArgumentAllocas(TheFunction);
985 if (Value *RetVal = Body->Codegen()) {
986 // Finish off the function.
987 Builder.CreateRet(RetVal);
989 // Validate the generated code, checking for consistency.
990 verifyFunction(*TheFunction);
992 // Optimize the function.
993 TheFPM->run(*TheFunction);
998 // Error reading body, remove function.
999 TheFunction->eraseFromParent();
1001 if (Proto->isBinaryOp())
1002 BinopPrecedence.erase(Proto->getOperatorName());
1006 //===----------------------------------------------------------------------===//
1007 // Top-Level parsing and JIT Driver
1008 //===----------------------------------------------------------------------===//
1010 static ExecutionEngine *TheExecutionEngine;
1012 static void HandleDefinition() {
1013 if (FunctionAST *F = ParseDefinition()) {
1014 if (Function *LF = F->Codegen()) {
1015 #ifndef MINIMAL_STDERR_OUTPUT
1016 fprintf(stderr, "Read function definition:");
1021 // Skip token for error recovery.
1026 static void HandleExtern() {
1027 if (PrototypeAST *P = ParseExtern()) {
1028 if (Function *F = P->Codegen()) {
1029 #ifndef MINIMAL_STDERR_OUTPUT
1030 fprintf(stderr, "Read extern: ");
1035 // Skip token for error recovery.
1040 static void HandleTopLevelExpression() {
1041 // Evaluate a top-level expression into an anonymous function.
1042 if (FunctionAST *F = ParseTopLevelExpr()) {
1043 if (Function *LF = F->Codegen()) {
1044 // JIT the function, returning a function pointer.
1045 void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
1046 // Cast it to the right type (takes no arguments, returns a double) so we
1047 // can call it as a native function.
1048 double (*FP)() = (double (*)())(intptr_t)FPtr;
1049 #ifdef MINIMAL_STDERR_OUTPUT
1052 fprintf(stderr, "Evaluated to %f\n", FP());
1056 // Skip token for error recovery.
1061 /// top ::= definition | external | expression | ';'
1062 static void MainLoop() {
1064 #ifndef MINIMAL_STDERR_OUTPUT
1065 fprintf(stderr, "ready> ");
1068 case tok_eof: return;
1069 case ';': getNextToken(); break; // ignore top-level semicolons.
1070 case tok_def: HandleDefinition(); break;
1071 case tok_extern: HandleExtern(); break;
1072 default: HandleTopLevelExpression(); break;
1077 //===----------------------------------------------------------------------===//
1078 // "Library" functions that can be "extern'd" from user code.
1079 //===----------------------------------------------------------------------===//
1081 /// putchard - putchar that takes a double and returns 0.
1083 double putchard(double X) {
1088 /// printd - printf that takes a double prints it as "%f\n", returning 0.
1090 double printd(double X) {
1101 //===----------------------------------------------------------------------===//
1102 // Main driver code.
1103 //===----------------------------------------------------------------------===//
1105 int main(int argc, char **argv) {
1106 InitializeNativeTarget();
1107 LLVMContext &Context = getGlobalContext();
1109 // Install standard binary operators.
1110 // 1 is lowest precedence.
1111 BinopPrecedence['='] = 2;
1112 BinopPrecedence['<'] = 10;
1113 BinopPrecedence['+'] = 20;
1114 BinopPrecedence['-'] = 20;
1115 BinopPrecedence['/'] = 40;
1116 BinopPrecedence['*'] = 40; // highest.
1118 // Make the module, which holds all the code.
1119 TheModule = new Module("my cool jit", Context);
1121 // Create the JIT. This takes ownership of the module.
1123 TheExecutionEngine = EngineBuilder(TheModule).setErrorStr(&ErrStr).create();
1124 if (!TheExecutionEngine) {
1125 fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
1129 FunctionPassManager OurFPM(TheModule);
1131 // Set up the optimizer pipeline. Start with registering info about how the
1132 // target lays out data structures.
1133 OurFPM.add(new DataLayout(*TheExecutionEngine->getDataLayout()));
1134 // Provide basic AliasAnalysis support for GVN.
1135 OurFPM.add(createBasicAliasAnalysisPass());
1136 // Promote allocas to registers.
1137 OurFPM.add(createPromoteMemoryToRegisterPass());
1138 // Do simple "peephole" optimizations and bit-twiddling optzns.
1139 OurFPM.add(createInstructionCombiningPass());
1140 // Reassociate expressions.
1141 OurFPM.add(createReassociatePass());
1142 // Eliminate Common SubExpressions.
1143 OurFPM.add(createGVNPass());
1144 // Simplify the control flow graph (deleting unreachable blocks, etc).
1145 OurFPM.add(createCFGSimplificationPass());
1147 OurFPM.doInitialization();
1149 // Set the global so the code gen can use this.
1152 // Prime the first token.
1153 #ifndef MINIMAL_STDERR_OUTPUT
1154 fprintf(stderr, "ready> ");
1158 // Run the main "interpreter loop" now.
1161 // Print out all of the generated code.
1163 #ifndef MINIMAL_STDERR_OUTPUT