1 #define MINIMAL_STDERR_OUTPUT
3 #include "llvm/Analysis/Passes.h"
4 #include "llvm/ExecutionEngine/ExecutionEngine.h"
5 #include "llvm/ExecutionEngine/JIT.h"
6 #include "llvm/IR/DataLayout.h"
7 #include "llvm/IR/DerivedTypes.h"
8 #include "llvm/IR/IRBuilder.h"
9 #include "llvm/IR/LLVMContext.h"
10 #include "llvm/IR/Module.h"
11 #include "llvm/IR/Verifier.h"
12 #include "llvm/PassManager.h"
13 #include "llvm/Support/TargetSelect.h"
14 #include "llvm/Transforms/Scalar.h"
23 //===----------------------------------------------------------------------===//
25 //===----------------------------------------------------------------------===//
27 // The lexer returns tokens [0-255] if it is an unknown character, otherwise one
28 // of these for known things.
33 tok_def = -2, tok_extern = -3,
36 tok_identifier = -4, tok_number = -5,
39 tok_if = -6, tok_then = -7, tok_else = -8,
40 tok_for = -9, tok_in = -10,
43 tok_binary = -11, tok_unary = -12,
49 static std::string IdentifierStr; // Filled in if tok_identifier
50 static double NumVal; // Filled in if tok_number
52 /// gettok - Return the next token from standard input.
54 static int LastChar = ' ';
56 // Skip any whitespace.
57 while (isspace(LastChar))
60 if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
61 IdentifierStr = LastChar;
62 while (isalnum((LastChar = getchar())))
63 IdentifierStr += LastChar;
65 if (IdentifierStr == "def") return tok_def;
66 if (IdentifierStr == "extern") return tok_extern;
67 if (IdentifierStr == "if") return tok_if;
68 if (IdentifierStr == "then") return tok_then;
69 if (IdentifierStr == "else") return tok_else;
70 if (IdentifierStr == "for") return tok_for;
71 if (IdentifierStr == "in") return tok_in;
72 if (IdentifierStr == "binary") return tok_binary;
73 if (IdentifierStr == "unary") return tok_unary;
74 if (IdentifierStr == "var") return tok_var;
75 return tok_identifier;
78 if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
83 } while (isdigit(LastChar) || LastChar == '.');
85 NumVal = strtod(NumStr.c_str(), 0);
89 if (LastChar == '#') {
90 // Comment until end of line.
91 do LastChar = getchar();
92 while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
98 // Check for end of file. Don't eat the EOF.
102 // Otherwise, just return the character as its ascii value.
103 int ThisChar = LastChar;
104 LastChar = getchar();
108 //===----------------------------------------------------------------------===//
109 // Abstract Syntax Tree (aka Parse Tree)
110 //===----------------------------------------------------------------------===//
112 /// ExprAST - Base class for all expression nodes.
115 virtual ~ExprAST() {}
116 virtual Value *Codegen() = 0;
119 /// NumberExprAST - Expression class for numeric literals like "1.0".
120 class NumberExprAST : public ExprAST {
123 NumberExprAST(double val) : Val(val) {}
124 virtual Value *Codegen();
127 /// VariableExprAST - Expression class for referencing a variable, like "a".
128 class VariableExprAST : public ExprAST {
131 VariableExprAST(const std::string &name) : Name(name) {}
132 const std::string &getName() const { return Name; }
133 virtual Value *Codegen();
136 /// UnaryExprAST - Expression class for a unary operator.
137 class UnaryExprAST : public ExprAST {
141 UnaryExprAST(char opcode, ExprAST *operand)
142 : Opcode(opcode), Operand(operand) {}
143 virtual Value *Codegen();
146 /// BinaryExprAST - Expression class for a binary operator.
147 class BinaryExprAST : public ExprAST {
151 BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
152 : Op(op), LHS(lhs), RHS(rhs) {}
153 virtual Value *Codegen();
156 /// CallExprAST - Expression class for function calls.
157 class CallExprAST : public ExprAST {
159 std::vector<ExprAST*> Args;
161 CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
162 : Callee(callee), Args(args) {}
163 virtual Value *Codegen();
166 /// IfExprAST - Expression class for if/then/else.
167 class IfExprAST : public ExprAST {
168 ExprAST *Cond, *Then, *Else;
170 IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
171 : Cond(cond), Then(then), Else(_else) {}
172 virtual Value *Codegen();
175 /// ForExprAST - Expression class for for/in.
176 class ForExprAST : public ExprAST {
178 ExprAST *Start, *End, *Step, *Body;
180 ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
181 ExprAST *step, ExprAST *body)
182 : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
183 virtual Value *Codegen();
186 /// VarExprAST - Expression class for var/in
187 class VarExprAST : public ExprAST {
188 std::vector<std::pair<std::string, ExprAST*> > VarNames;
191 VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
193 : VarNames(varnames), Body(body) {}
195 virtual Value *Codegen();
198 /// PrototypeAST - This class represents the "prototype" for a function,
199 /// which captures its argument names as well as if it is an operator.
202 std::vector<std::string> Args;
204 unsigned Precedence; // Precedence if a binary op.
206 PrototypeAST(const std::string &name, const std::vector<std::string> &args,
207 bool isoperator = false, unsigned prec = 0)
208 : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
210 bool isUnaryOp() const { return isOperator && Args.size() == 1; }
211 bool isBinaryOp() const { return isOperator && Args.size() == 2; }
213 char getOperatorName() const {
214 assert(isUnaryOp() || isBinaryOp());
215 return Name[Name.size()-1];
218 unsigned getBinaryPrecedence() const { return Precedence; }
222 void CreateArgumentAllocas(Function *F);
225 /// FunctionAST - This class represents a function definition itself.
230 FunctionAST(PrototypeAST *proto, ExprAST *body)
231 : Proto(proto), Body(body) {}
236 //===----------------------------------------------------------------------===//
238 //===----------------------------------------------------------------------===//
240 /// CurTok/getNextToken - Provide a simple token buffer. CurTok is the current
241 /// token the parser is looking at. getNextToken reads another token from the
242 /// lexer and updates CurTok with its results.
244 static int getNextToken() {
245 return CurTok = gettok();
248 /// BinopPrecedence - This holds the precedence for each binary operator that is
250 static std::map<char, int> BinopPrecedence;
252 /// GetTokPrecedence - Get the precedence of the pending binary operator token.
253 static int GetTokPrecedence() {
254 if (!isascii(CurTok))
257 // Make sure it's a declared binop.
258 int TokPrec = BinopPrecedence[CurTok];
259 if (TokPrec <= 0) return -1;
263 /// Error* - These are little helper functions for error handling.
264 ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
265 PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
266 FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
268 static ExprAST *ParseExpression();
272 /// ::= identifier '(' expression* ')'
273 static ExprAST *ParseIdentifierExpr() {
274 std::string IdName = IdentifierStr;
276 getNextToken(); // eat identifier.
278 if (CurTok != '(') // Simple variable ref.
279 return new VariableExprAST(IdName);
282 getNextToken(); // eat (
283 std::vector<ExprAST*> Args;
286 ExprAST *Arg = ParseExpression();
290 if (CurTok == ')') break;
293 return Error("Expected ')' or ',' in argument list");
301 return new CallExprAST(IdName, Args);
304 /// numberexpr ::= number
305 static ExprAST *ParseNumberExpr() {
306 ExprAST *Result = new NumberExprAST(NumVal);
307 getNextToken(); // consume the number
311 /// parenexpr ::= '(' expression ')'
312 static ExprAST *ParseParenExpr() {
313 getNextToken(); // eat (.
314 ExprAST *V = ParseExpression();
318 return Error("expected ')'");
319 getNextToken(); // eat ).
323 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
324 static ExprAST *ParseIfExpr() {
325 getNextToken(); // eat the if.
328 ExprAST *Cond = ParseExpression();
331 if (CurTok != tok_then)
332 return Error("expected then");
333 getNextToken(); // eat the then
335 ExprAST *Then = ParseExpression();
336 if (Then == 0) return 0;
338 if (CurTok != tok_else)
339 return Error("expected else");
343 ExprAST *Else = ParseExpression();
346 return new IfExprAST(Cond, Then, Else);
349 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
350 static ExprAST *ParseForExpr() {
351 getNextToken(); // eat the for.
353 if (CurTok != tok_identifier)
354 return Error("expected identifier after for");
356 std::string IdName = IdentifierStr;
357 getNextToken(); // eat identifier.
360 return Error("expected '=' after for");
361 getNextToken(); // eat '='.
364 ExprAST *Start = ParseExpression();
365 if (Start == 0) return 0;
367 return Error("expected ',' after for start value");
370 ExprAST *End = ParseExpression();
371 if (End == 0) return 0;
373 // The step value is optional.
377 Step = ParseExpression();
378 if (Step == 0) return 0;
381 if (CurTok != tok_in)
382 return Error("expected 'in' after for");
383 getNextToken(); // eat 'in'.
385 ExprAST *Body = ParseExpression();
386 if (Body == 0) return 0;
388 return new ForExprAST(IdName, Start, End, Step, Body);
391 /// varexpr ::= 'var' identifier ('=' expression)?
392 // (',' identifier ('=' expression)?)* 'in' expression
393 static ExprAST *ParseVarExpr() {
394 getNextToken(); // eat the var.
396 std::vector<std::pair<std::string, ExprAST*> > VarNames;
398 // At least one variable name is required.
399 if (CurTok != tok_identifier)
400 return Error("expected identifier after var");
403 std::string Name = IdentifierStr;
404 getNextToken(); // eat identifier.
406 // Read the optional initializer.
409 getNextToken(); // eat the '='.
411 Init = ParseExpression();
412 if (Init == 0) return 0;
415 VarNames.push_back(std::make_pair(Name, Init));
417 // End of var list, exit loop.
418 if (CurTok != ',') break;
419 getNextToken(); // eat the ','.
421 if (CurTok != tok_identifier)
422 return Error("expected identifier list after var");
425 // At this point, we have to have 'in'.
426 if (CurTok != tok_in)
427 return Error("expected 'in' keyword after 'var'");
428 getNextToken(); // eat 'in'.
430 ExprAST *Body = ParseExpression();
431 if (Body == 0) return 0;
433 return new VarExprAST(VarNames, Body);
437 /// ::= identifierexpr
443 static ExprAST *ParsePrimary() {
445 default: return Error("unknown token when expecting an expression");
446 case tok_identifier: return ParseIdentifierExpr();
447 case tok_number: return ParseNumberExpr();
448 case '(': return ParseParenExpr();
449 case tok_if: return ParseIfExpr();
450 case tok_for: return ParseForExpr();
451 case tok_var: return ParseVarExpr();
458 static ExprAST *ParseUnary() {
459 // If the current token is not an operator, it must be a primary expr.
460 if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
461 return ParsePrimary();
463 // If this is a unary operator, read it.
466 if (ExprAST *Operand = ParseUnary())
467 return new UnaryExprAST(Opc, Operand);
473 static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
474 // If this is a binop, find its precedence.
476 int TokPrec = GetTokPrecedence();
478 // If this is a binop that binds at least as tightly as the current binop,
479 // consume it, otherwise we are done.
480 if (TokPrec < ExprPrec)
483 // Okay, we know this is a binop.
485 getNextToken(); // eat binop
487 // Parse the unary expression after the binary operator.
488 ExprAST *RHS = ParseUnary();
491 // If BinOp binds less tightly with RHS than the operator after RHS, let
492 // the pending operator take RHS as its LHS.
493 int NextPrec = GetTokPrecedence();
494 if (TokPrec < NextPrec) {
495 RHS = ParseBinOpRHS(TokPrec+1, RHS);
496 if (RHS == 0) return 0;
500 LHS = new BinaryExprAST(BinOp, LHS, RHS);
505 /// ::= unary binoprhs
507 static ExprAST *ParseExpression() {
508 ExprAST *LHS = ParseUnary();
511 return ParseBinOpRHS(0, LHS);
515 /// ::= id '(' id* ')'
516 /// ::= binary LETTER number? (id, id)
517 /// ::= unary LETTER (id)
518 static PrototypeAST *ParsePrototype() {
521 unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
522 unsigned BinaryPrecedence = 30;
526 return ErrorP("Expected function name in prototype");
528 FnName = IdentifierStr;
534 if (!isascii(CurTok))
535 return ErrorP("Expected unary operator");
537 FnName += (char)CurTok;
543 if (!isascii(CurTok))
544 return ErrorP("Expected binary operator");
546 FnName += (char)CurTok;
550 // Read the precedence if present.
551 if (CurTok == tok_number) {
552 if (NumVal < 1 || NumVal > 100)
553 return ErrorP("Invalid precedecnce: must be 1..100");
554 BinaryPrecedence = (unsigned)NumVal;
561 return ErrorP("Expected '(' in prototype");
563 std::vector<std::string> ArgNames;
564 while (getNextToken() == tok_identifier)
565 ArgNames.push_back(IdentifierStr);
567 return ErrorP("Expected ')' in prototype");
570 getNextToken(); // eat ')'.
572 // Verify right number of names for operator.
573 if (Kind && ArgNames.size() != Kind)
574 return ErrorP("Invalid number of operands for operator");
576 return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
579 /// definition ::= 'def' prototype expression
580 static FunctionAST *ParseDefinition() {
581 getNextToken(); // eat def.
582 PrototypeAST *Proto = ParsePrototype();
583 if (Proto == 0) return 0;
585 if (ExprAST *E = ParseExpression())
586 return new FunctionAST(Proto, E);
590 /// toplevelexpr ::= expression
591 static FunctionAST *ParseTopLevelExpr() {
592 if (ExprAST *E = ParseExpression()) {
593 // Make an anonymous proto.
594 PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
595 return new FunctionAST(Proto, E);
600 /// external ::= 'extern' prototype
601 static PrototypeAST *ParseExtern() {
602 getNextToken(); // eat extern.
603 return ParsePrototype();
606 //===----------------------------------------------------------------------===//
608 //===----------------------------------------------------------------------===//
610 static Module *TheModule;
611 static FunctionPassManager *TheFPM;
612 static IRBuilder<> Builder(getGlobalContext());
613 static std::map<std::string, AllocaInst*> NamedValues;
615 Value *ErrorV(const char *Str) { Error(Str); return 0; }
617 /// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
618 /// the function. This is used for mutable variables etc.
619 static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
620 const std::string &VarName) {
621 IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
622 TheFunction->getEntryBlock().begin());
623 return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
627 Value *NumberExprAST::Codegen() {
628 return ConstantFP::get(getGlobalContext(), APFloat(Val));
631 Value *VariableExprAST::Codegen() {
632 // Look this variable up in the function.
633 Value *V = NamedValues[Name];
634 if (V == 0) return ErrorV("Unknown variable name");
637 return Builder.CreateLoad(V, Name.c_str());
640 Value *UnaryExprAST::Codegen() {
641 Value *OperandV = Operand->Codegen();
642 if (OperandV == 0) return 0;
644 Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("unary")+Opcode));
646 Function *F = TheModule->getFunction(std::string("unary")+Opcode);
649 return ErrorV("Unknown unary operator");
651 return Builder.CreateCall(F, OperandV, "unop");
654 Value *BinaryExprAST::Codegen() {
655 // Special case '=' because we don't want to emit the LHS as an expression.
657 // Assignment requires the LHS to be an identifier.
658 VariableExprAST *LHSE = dynamic_cast<VariableExprAST*>(LHS);
660 return ErrorV("destination of '=' must be a variable");
662 Value *Val = RHS->Codegen();
663 if (Val == 0) return 0;
666 Value *Variable = NamedValues[LHSE->getName()];
667 if (Variable == 0) return ErrorV("Unknown variable name");
669 Builder.CreateStore(Val, Variable);
673 Value *L = LHS->Codegen();
674 Value *R = RHS->Codegen();
675 if (L == 0 || R == 0) return 0;
678 case '+': return Builder.CreateFAdd(L, R, "addtmp");
679 case '-': return Builder.CreateFSub(L, R, "subtmp");
680 case '*': return Builder.CreateFMul(L, R, "multmp");
681 case '/': return Builder.CreateFDiv(L, R, "divtmp");
683 L = Builder.CreateFCmpULT(L, R, "cmptmp");
684 // Convert bool 0/1 to double 0.0 or 1.0
685 return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
690 // If it wasn't a builtin binary operator, it must be a user defined one. Emit
692 Function *F = TheModule->getFunction(std::string("binary")+Op);
693 assert(F && "binary operator not found!");
695 Value *Ops[] = { L, R };
696 return Builder.CreateCall(F, Ops, "binop");
699 Value *CallExprAST::Codegen() {
700 // Look up the name in the global module table.
701 Function *CalleeF = TheModule->getFunction(Callee);
704 sprintf(error_str, "Unknown function referenced %s", Callee.c_str());
705 return ErrorV(error_str);
708 // If argument mismatch error.
709 if (CalleeF->arg_size() != Args.size())
710 return ErrorV("Incorrect # arguments passed");
712 std::vector<Value*> ArgsV;
713 for (unsigned i = 0, e = Args.size(); i != e; ++i) {
714 ArgsV.push_back(Args[i]->Codegen());
715 if (ArgsV.back() == 0) return 0;
718 return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
721 Value *IfExprAST::Codegen() {
722 Value *CondV = Cond->Codegen();
723 if (CondV == 0) return 0;
725 // Convert condition to a bool by comparing equal to 0.0.
726 CondV = Builder.CreateFCmpONE(CondV,
727 ConstantFP::get(getGlobalContext(), APFloat(0.0)),
730 Function *TheFunction = Builder.GetInsertBlock()->getParent();
732 // Create blocks for the then and else cases. Insert the 'then' block at the
733 // end of the function.
734 BasicBlock *ThenBB = BasicBlock::Create(getGlobalContext(), "then", TheFunction);
735 BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
736 BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
738 Builder.CreateCondBr(CondV, ThenBB, ElseBB);
741 Builder.SetInsertPoint(ThenBB);
743 Value *ThenV = Then->Codegen();
744 if (ThenV == 0) return 0;
746 Builder.CreateBr(MergeBB);
747 // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
748 ThenBB = Builder.GetInsertBlock();
751 TheFunction->getBasicBlockList().push_back(ElseBB);
752 Builder.SetInsertPoint(ElseBB);
754 Value *ElseV = Else->Codegen();
755 if (ElseV == 0) return 0;
757 Builder.CreateBr(MergeBB);
758 // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
759 ElseBB = Builder.GetInsertBlock();
762 TheFunction->getBasicBlockList().push_back(MergeBB);
763 Builder.SetInsertPoint(MergeBB);
764 PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
767 PN->addIncoming(ThenV, ThenBB);
768 PN->addIncoming(ElseV, ElseBB);
772 Value *ForExprAST::Codegen() {
774 // var = alloca double
777 // store start -> var
788 // nextvar = curvar + step
789 // store nextvar -> var
790 // br endcond, loop, endloop
793 Function *TheFunction = Builder.GetInsertBlock()->getParent();
795 // Create an alloca for the variable in the entry block.
796 AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
798 // Emit the start code first, without 'variable' in scope.
799 Value *StartVal = Start->Codegen();
800 if (StartVal == 0) return 0;
802 // Store the value into the alloca.
803 Builder.CreateStore(StartVal, Alloca);
805 // Make the new basic block for the loop header, inserting after current
807 BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
809 // Insert an explicit fall through from the current block to the LoopBB.
810 Builder.CreateBr(LoopBB);
812 // Start insertion in LoopBB.
813 Builder.SetInsertPoint(LoopBB);
815 // Within the loop, the variable is defined equal to the PHI node. If it
816 // shadows an existing variable, we have to restore it, so save it now.
817 AllocaInst *OldVal = NamedValues[VarName];
818 NamedValues[VarName] = Alloca;
820 // Emit the body of the loop. This, like any other expr, can change the
821 // current BB. Note that we ignore the value computed by the body, but don't
823 if (Body->Codegen() == 0)
826 // Emit the step value.
829 StepVal = Step->Codegen();
830 if (StepVal == 0) return 0;
832 // If not specified, use 1.0.
833 StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
836 // Compute the end condition.
837 Value *EndCond = End->Codegen();
838 if (EndCond == 0) return EndCond;
840 // Reload, increment, and restore the alloca. This handles the case where
841 // the body of the loop mutates the variable.
842 Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
843 Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
844 Builder.CreateStore(NextVar, Alloca);
846 // Convert condition to a bool by comparing equal to 0.0.
847 EndCond = Builder.CreateFCmpONE(EndCond,
848 ConstantFP::get(getGlobalContext(), APFloat(0.0)),
851 // Create the "after loop" block and insert it.
852 BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
854 // Insert the conditional branch into the end of LoopEndBB.
855 Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
857 // Any new code will be inserted in AfterBB.
858 Builder.SetInsertPoint(AfterBB);
860 // Restore the unshadowed variable.
862 NamedValues[VarName] = OldVal;
864 NamedValues.erase(VarName);
867 // for expr always returns 0.0.
868 return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
871 Value *VarExprAST::Codegen() {
872 std::vector<AllocaInst *> OldBindings;
874 Function *TheFunction = Builder.GetInsertBlock()->getParent();
876 // Register all variables and emit their initializer.
877 for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
878 const std::string &VarName = VarNames[i].first;
879 ExprAST *Init = VarNames[i].second;
881 // Emit the initializer before adding the variable to scope, this prevents
882 // the initializer from referencing the variable itself, and permits stuff
885 // var a = a in ... # refers to outer 'a'.
888 InitVal = Init->Codegen();
889 if (InitVal == 0) return 0;
890 } else { // If not specified, use 0.0.
891 InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
894 AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
895 Builder.CreateStore(InitVal, Alloca);
897 // Remember the old variable binding so that we can restore the binding when
899 OldBindings.push_back(NamedValues[VarName]);
901 // Remember this binding.
902 NamedValues[VarName] = Alloca;
905 // Codegen the body, now that all vars are in scope.
906 Value *BodyVal = Body->Codegen();
907 if (BodyVal == 0) return 0;
909 // Pop all our variables from scope.
910 for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
911 NamedValues[VarNames[i].first] = OldBindings[i];
913 // Return the body computation.
917 Function *PrototypeAST::Codegen() {
918 // Make the function type: double(double,double) etc.
919 std::vector<Type*> Doubles(Args.size(),
920 Type::getDoubleTy(getGlobalContext()));
921 FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
924 Function *F = Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
925 // If F conflicted, there was already something named 'Name'. If it has a
926 // body, don't allow redefinition or reextern.
927 if (F->getName() != Name) {
928 // Delete the one we just made and get the existing one.
929 F->eraseFromParent();
930 F = TheModule->getFunction(Name);
931 // If F already has a body, reject this.
933 ErrorF("redefinition of function");
936 // If F took a different number of args, reject.
937 if (F->arg_size() != Args.size()) {
938 ErrorF("redefinition of function with different # args");
943 // Set names for all arguments.
945 for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
947 AI->setName(Args[Idx]);
952 /// CreateArgumentAllocas - Create an alloca for each argument and register the
953 /// argument in the symbol table so that references to it will succeed.
954 void PrototypeAST::CreateArgumentAllocas(Function *F) {
955 Function::arg_iterator AI = F->arg_begin();
956 for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
957 // Create an alloca for this variable.
958 AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
960 // Store the initial value into the alloca.
961 Builder.CreateStore(AI, Alloca);
963 // Add arguments to variable symbol table.
964 NamedValues[Args[Idx]] = Alloca;
968 Function *FunctionAST::Codegen() {
971 Function *TheFunction = Proto->Codegen();
972 if (TheFunction == 0)
975 // If this is an operator, install it.
976 if (Proto->isBinaryOp())
977 BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
979 // Create a new basic block to start insertion into.
980 BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
981 Builder.SetInsertPoint(BB);
983 // Add all arguments to the symbol table and create their allocas.
984 Proto->CreateArgumentAllocas(TheFunction);
986 if (Value *RetVal = Body->Codegen()) {
987 // Finish off the function.
988 Builder.CreateRet(RetVal);
990 // Validate the generated code, checking for consistency.
991 verifyFunction(*TheFunction);
993 // Optimize the function.
994 TheFPM->run(*TheFunction);
999 // Error reading body, remove function.
1000 TheFunction->eraseFromParent();
1002 if (Proto->isBinaryOp())
1003 BinopPrecedence.erase(Proto->getOperatorName());
1007 //===----------------------------------------------------------------------===//
1008 // Top-Level parsing and JIT Driver
1009 //===----------------------------------------------------------------------===//
1011 static ExecutionEngine *TheExecutionEngine;
1013 static void HandleDefinition() {
1014 if (FunctionAST *F = ParseDefinition()) {
1015 if (Function *LF = F->Codegen()) {
1016 #ifndef MINIMAL_STDERR_OUTPUT
1017 fprintf(stderr, "Read function definition:");
1022 // Skip token for error recovery.
1027 static void HandleExtern() {
1028 if (PrototypeAST *P = ParseExtern()) {
1029 if (Function *F = P->Codegen()) {
1030 #ifndef MINIMAL_STDERR_OUTPUT
1031 fprintf(stderr, "Read extern: ");
1036 // Skip token for error recovery.
1041 static void HandleTopLevelExpression() {
1042 // Evaluate a top-level expression into an anonymous function.
1043 if (FunctionAST *F = ParseTopLevelExpr()) {
1044 if (Function *LF = F->Codegen()) {
1045 // JIT the function, returning a function pointer.
1046 void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
1047 // Cast it to the right type (takes no arguments, returns a double) so we
1048 // can call it as a native function.
1049 double (*FP)() = (double (*)())(intptr_t)FPtr;
1050 #ifdef MINIMAL_STDERR_OUTPUT
1053 fprintf(stderr, "Evaluated to %f\n", FP());
1057 // Skip token for error recovery.
1062 /// top ::= definition | external | expression | ';'
1063 static void MainLoop() {
1065 #ifndef MINIMAL_STDERR_OUTPUT
1066 fprintf(stderr, "ready> ");
1069 case tok_eof: return;
1070 case ';': getNextToken(); break; // ignore top-level semicolons.
1071 case tok_def: HandleDefinition(); break;
1072 case tok_extern: HandleExtern(); break;
1073 default: HandleTopLevelExpression(); break;
1078 //===----------------------------------------------------------------------===//
1079 // "Library" functions that can be "extern'd" from user code.
1080 //===----------------------------------------------------------------------===//
1082 /// putchard - putchar that takes a double and returns 0.
1084 double putchard(double X) {
1089 /// printd - printf that takes a double prints it as "%f\n", returning 0.
1091 double printd(double X) {
1102 //===----------------------------------------------------------------------===//
1103 // Main driver code.
1104 //===----------------------------------------------------------------------===//
1106 int main(int argc, char **argv) {
1107 InitializeNativeTarget();
1108 LLVMContext &Context = getGlobalContext();
1110 // Install standard binary operators.
1111 // 1 is lowest precedence.
1112 BinopPrecedence['='] = 2;
1113 BinopPrecedence['<'] = 10;
1114 BinopPrecedence['+'] = 20;
1115 BinopPrecedence['-'] = 20;
1116 BinopPrecedence['/'] = 40;
1117 BinopPrecedence['*'] = 40; // highest.
1119 // Make the module, which holds all the code.
1120 TheModule = new Module("my cool jit", Context);
1122 // Create the JIT. This takes ownership of the module.
1124 TheExecutionEngine = EngineBuilder(TheModule).setErrorStr(&ErrStr).create();
1125 if (!TheExecutionEngine) {
1126 fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
1130 FunctionPassManager OurFPM(TheModule);
1132 // Set up the optimizer pipeline. Start with registering info about how the
1133 // target lays out data structures.
1134 OurFPM.add(new DataLayout(*TheExecutionEngine->getDataLayout()));
1135 // Provide basic AliasAnalysis support for GVN.
1136 OurFPM.add(createBasicAliasAnalysisPass());
1137 // Promote allocas to registers.
1138 OurFPM.add(createPromoteMemoryToRegisterPass());
1139 // Do simple "peephole" optimizations and bit-twiddling optzns.
1140 OurFPM.add(createInstructionCombiningPass());
1141 // Reassociate expressions.
1142 OurFPM.add(createReassociatePass());
1143 // Eliminate Common SubExpressions.
1144 OurFPM.add(createGVNPass());
1145 // Simplify the control flow graph (deleting unreachable blocks, etc).
1146 OurFPM.add(createCFGSimplificationPass());
1148 OurFPM.doInitialization();
1150 // Set the global so the code gen can use this.
1153 // Prime the first token.
1154 #ifndef MINIMAL_STDERR_OUTPUT
1155 fprintf(stderr, "ready> ");
1159 // Run the main "interpreter loop" now.
1162 // Print out all of the generated code.
1164 #ifndef MINIMAL_STDERR_OUTPUT