1 #include "llvm/DerivedTypes.h"
2 #include "llvm/ExecutionEngine/ExecutionEngine.h"
3 #include "llvm/LLVMContext.h"
4 #include "llvm/Module.h"
5 #include "llvm/ModuleProvider.h"
6 #include "llvm/PassManager.h"
7 #include "llvm/Analysis/Verifier.h"
8 #include "llvm/Target/TargetData.h"
9 #include "llvm/Target/TargetSelect.h"
10 #include "llvm/Transforms/Scalar.h"
11 #include "llvm/Support/IRBuilder.h"
18 //===----------------------------------------------------------------------===//
20 //===----------------------------------------------------------------------===//
22 // The lexer returns tokens [0-255] if it is an unknown character, otherwise one
23 // of these for known things.
28 tok_def = -2, tok_extern = -3,
31 tok_identifier = -4, tok_number = -5,
34 tok_if = -6, tok_then = -7, tok_else = -8,
35 tok_for = -9, tok_in = -10,
38 tok_binary = -11, tok_unary = -12,
44 static std::string IdentifierStr; // Filled in if tok_identifier
45 static double NumVal; // Filled in if tok_number
47 /// gettok - Return the next token from standard input.
49 static int LastChar = ' ';
51 // Skip any whitespace.
52 while (isspace(LastChar))
55 if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
56 IdentifierStr = LastChar;
57 while (isalnum((LastChar = getchar())))
58 IdentifierStr += LastChar;
60 if (IdentifierStr == "def") return tok_def;
61 if (IdentifierStr == "extern") return tok_extern;
62 if (IdentifierStr == "if") return tok_if;
63 if (IdentifierStr == "then") return tok_then;
64 if (IdentifierStr == "else") return tok_else;
65 if (IdentifierStr == "for") return tok_for;
66 if (IdentifierStr == "in") return tok_in;
67 if (IdentifierStr == "binary") return tok_binary;
68 if (IdentifierStr == "unary") return tok_unary;
69 if (IdentifierStr == "var") return tok_var;
70 return tok_identifier;
73 if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
78 } while (isdigit(LastChar) || LastChar == '.');
80 NumVal = strtod(NumStr.c_str(), 0);
84 if (LastChar == '#') {
85 // Comment until end of line.
86 do LastChar = getchar();
87 while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
93 // Check for end of file. Don't eat the EOF.
97 // Otherwise, just return the character as its ascii value.
98 int ThisChar = LastChar;
103 //===----------------------------------------------------------------------===//
104 // Abstract Syntax Tree (aka Parse Tree)
105 //===----------------------------------------------------------------------===//
107 /// ExprAST - Base class for all expression nodes.
110 virtual ~ExprAST() {}
111 virtual Value *Codegen() = 0;
114 /// NumberExprAST - Expression class for numeric literals like "1.0".
115 class NumberExprAST : public ExprAST {
118 NumberExprAST(double val) : Val(val) {}
119 virtual Value *Codegen();
122 /// VariableExprAST - Expression class for referencing a variable, like "a".
123 class VariableExprAST : public ExprAST {
126 VariableExprAST(const std::string &name) : Name(name) {}
127 const std::string &getName() const { return Name; }
128 virtual Value *Codegen();
131 /// UnaryExprAST - Expression class for a unary operator.
132 class UnaryExprAST : public ExprAST {
136 UnaryExprAST(char opcode, ExprAST *operand)
137 : Opcode(opcode), Operand(operand) {}
138 virtual Value *Codegen();
141 /// BinaryExprAST - Expression class for a binary operator.
142 class BinaryExprAST : public ExprAST {
146 BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
147 : Op(op), LHS(lhs), RHS(rhs) {}
148 virtual Value *Codegen();
151 /// CallExprAST - Expression class for function calls.
152 class CallExprAST : public ExprAST {
154 std::vector<ExprAST*> Args;
156 CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
157 : Callee(callee), Args(args) {}
158 virtual Value *Codegen();
161 /// IfExprAST - Expression class for if/then/else.
162 class IfExprAST : public ExprAST {
163 ExprAST *Cond, *Then, *Else;
165 IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
166 : Cond(cond), Then(then), Else(_else) {}
167 virtual Value *Codegen();
170 /// ForExprAST - Expression class for for/in.
171 class ForExprAST : public ExprAST {
173 ExprAST *Start, *End, *Step, *Body;
175 ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
176 ExprAST *step, ExprAST *body)
177 : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
178 virtual Value *Codegen();
181 /// VarExprAST - Expression class for var/in
182 class VarExprAST : public ExprAST {
183 std::vector<std::pair<std::string, ExprAST*> > VarNames;
186 VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
188 : VarNames(varnames), Body(body) {}
190 virtual Value *Codegen();
193 /// PrototypeAST - This class represents the "prototype" for a function,
194 /// which captures its argument names as well as if it is an operator.
197 std::vector<std::string> Args;
199 unsigned Precedence; // Precedence if a binary op.
201 PrototypeAST(const std::string &name, const std::vector<std::string> &args,
202 bool isoperator = false, unsigned prec = 0)
203 : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
205 bool isUnaryOp() const { return isOperator && Args.size() == 1; }
206 bool isBinaryOp() const { return isOperator && Args.size() == 2; }
208 char getOperatorName() const {
209 assert(isUnaryOp() || isBinaryOp());
210 return Name[Name.size()-1];
213 unsigned getBinaryPrecedence() const { return Precedence; }
217 void CreateArgumentAllocas(Function *F);
220 /// FunctionAST - This class represents a function definition itself.
225 FunctionAST(PrototypeAST *proto, ExprAST *body)
226 : Proto(proto), Body(body) {}
231 //===----------------------------------------------------------------------===//
233 //===----------------------------------------------------------------------===//
235 /// CurTok/getNextToken - Provide a simple token buffer. CurTok is the current
236 /// token the parser it looking at. getNextToken reads another token from the
237 /// lexer and updates CurTok with its results.
239 static int getNextToken() {
240 return CurTok = gettok();
243 /// BinopPrecedence - This holds the precedence for each binary operator that is
245 static std::map<char, int> BinopPrecedence;
247 /// GetTokPrecedence - Get the precedence of the pending binary operator token.
248 static int GetTokPrecedence() {
249 if (!isascii(CurTok))
252 // Make sure it's a declared binop.
253 int TokPrec = BinopPrecedence[CurTok];
254 if (TokPrec <= 0) return -1;
258 /// Error* - These are little helper functions for error handling.
259 ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
260 PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
261 FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
263 static ExprAST *ParseExpression();
267 /// ::= identifier '(' expression* ')'
268 static ExprAST *ParseIdentifierExpr() {
269 std::string IdName = IdentifierStr;
271 getNextToken(); // eat identifier.
273 if (CurTok != '(') // Simple variable ref.
274 return new VariableExprAST(IdName);
277 getNextToken(); // eat (
278 std::vector<ExprAST*> Args;
281 ExprAST *Arg = ParseExpression();
285 if (CurTok == ')') break;
288 return Error("Expected ')' or ',' in argument list");
296 return new CallExprAST(IdName, Args);
299 /// numberexpr ::= number
300 static ExprAST *ParseNumberExpr() {
301 ExprAST *Result = new NumberExprAST(NumVal);
302 getNextToken(); // consume the number
306 /// parenexpr ::= '(' expression ')'
307 static ExprAST *ParseParenExpr() {
308 getNextToken(); // eat (.
309 ExprAST *V = ParseExpression();
313 return Error("expected ')'");
314 getNextToken(); // eat ).
318 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
319 static ExprAST *ParseIfExpr() {
320 getNextToken(); // eat the if.
323 ExprAST *Cond = ParseExpression();
326 if (CurTok != tok_then)
327 return Error("expected then");
328 getNextToken(); // eat the then
330 ExprAST *Then = ParseExpression();
331 if (Then == 0) return 0;
333 if (CurTok != tok_else)
334 return Error("expected else");
338 ExprAST *Else = ParseExpression();
341 return new IfExprAST(Cond, Then, Else);
344 /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
345 static ExprAST *ParseForExpr() {
346 getNextToken(); // eat the for.
348 if (CurTok != tok_identifier)
349 return Error("expected identifier after for");
351 std::string IdName = IdentifierStr;
352 getNextToken(); // eat identifier.
355 return Error("expected '=' after for");
356 getNextToken(); // eat '='.
359 ExprAST *Start = ParseExpression();
360 if (Start == 0) return 0;
362 return Error("expected ',' after for start value");
365 ExprAST *End = ParseExpression();
366 if (End == 0) return 0;
368 // The step value is optional.
372 Step = ParseExpression();
373 if (Step == 0) return 0;
376 if (CurTok != tok_in)
377 return Error("expected 'in' after for");
378 getNextToken(); // eat 'in'.
380 ExprAST *Body = ParseExpression();
381 if (Body == 0) return 0;
383 return new ForExprAST(IdName, Start, End, Step, Body);
386 /// varexpr ::= 'var' identifier ('=' expression)?
387 // (',' identifier ('=' expression)?)* 'in' expression
388 static ExprAST *ParseVarExpr() {
389 getNextToken(); // eat the var.
391 std::vector<std::pair<std::string, ExprAST*> > VarNames;
393 // At least one variable name is required.
394 if (CurTok != tok_identifier)
395 return Error("expected identifier after var");
398 std::string Name = IdentifierStr;
399 getNextToken(); // eat identifier.
401 // Read the optional initializer.
404 getNextToken(); // eat the '='.
406 Init = ParseExpression();
407 if (Init == 0) return 0;
410 VarNames.push_back(std::make_pair(Name, Init));
412 // End of var list, exit loop.
413 if (CurTok != ',') break;
414 getNextToken(); // eat the ','.
416 if (CurTok != tok_identifier)
417 return Error("expected identifier list after var");
420 // At this point, we have to have 'in'.
421 if (CurTok != tok_in)
422 return Error("expected 'in' keyword after 'var'");
423 getNextToken(); // eat 'in'.
425 ExprAST *Body = ParseExpression();
426 if (Body == 0) return 0;
428 return new VarExprAST(VarNames, Body);
433 /// ::= identifierexpr
439 static ExprAST *ParsePrimary() {
441 default: return Error("unknown token when expecting an expression");
442 case tok_identifier: return ParseIdentifierExpr();
443 case tok_number: return ParseNumberExpr();
444 case '(': return ParseParenExpr();
445 case tok_if: return ParseIfExpr();
446 case tok_for: return ParseForExpr();
447 case tok_var: return ParseVarExpr();
454 static ExprAST *ParseUnary() {
455 // If the current token is not an operator, it must be a primary expr.
456 if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
457 return ParsePrimary();
459 // If this is a unary operator, read it.
462 if (ExprAST *Operand = ParseUnary())
463 return new UnaryExprAST(Opc, Operand);
469 static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
470 // If this is a binop, find its precedence.
472 int TokPrec = GetTokPrecedence();
474 // If this is a binop that binds at least as tightly as the current binop,
475 // consume it, otherwise we are done.
476 if (TokPrec < ExprPrec)
479 // Okay, we know this is a binop.
481 getNextToken(); // eat binop
483 // Parse the unary expression after the binary operator.
484 ExprAST *RHS = ParseUnary();
487 // If BinOp binds less tightly with RHS than the operator after RHS, let
488 // the pending operator take RHS as its LHS.
489 int NextPrec = GetTokPrecedence();
490 if (TokPrec < NextPrec) {
491 RHS = ParseBinOpRHS(TokPrec+1, RHS);
492 if (RHS == 0) return 0;
496 LHS = new BinaryExprAST(BinOp, LHS, RHS);
501 /// ::= unary binoprhs
503 static ExprAST *ParseExpression() {
504 ExprAST *LHS = ParseUnary();
507 return ParseBinOpRHS(0, LHS);
511 /// ::= id '(' id* ')'
512 /// ::= binary LETTER number? (id, id)
513 /// ::= unary LETTER (id)
514 static PrototypeAST *ParsePrototype() {
517 unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
518 unsigned BinaryPrecedence = 30;
522 return ErrorP("Expected function name in prototype");
524 FnName = IdentifierStr;
530 if (!isascii(CurTok))
531 return ErrorP("Expected unary operator");
533 FnName += (char)CurTok;
539 if (!isascii(CurTok))
540 return ErrorP("Expected binary operator");
542 FnName += (char)CurTok;
546 // Read the precedence if present.
547 if (CurTok == tok_number) {
548 if (NumVal < 1 || NumVal > 100)
549 return ErrorP("Invalid precedecnce: must be 1..100");
550 BinaryPrecedence = (unsigned)NumVal;
557 return ErrorP("Expected '(' in prototype");
559 std::vector<std::string> ArgNames;
560 while (getNextToken() == tok_identifier)
561 ArgNames.push_back(IdentifierStr);
563 return ErrorP("Expected ')' in prototype");
566 getNextToken(); // eat ')'.
568 // Verify right number of names for operator.
569 if (Kind && ArgNames.size() != Kind)
570 return ErrorP("Invalid number of operands for operator");
572 return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
575 /// definition ::= 'def' prototype expression
576 static FunctionAST *ParseDefinition() {
577 getNextToken(); // eat def.
578 PrototypeAST *Proto = ParsePrototype();
579 if (Proto == 0) return 0;
581 if (ExprAST *E = ParseExpression())
582 return new FunctionAST(Proto, E);
586 /// toplevelexpr ::= expression
587 static FunctionAST *ParseTopLevelExpr() {
588 if (ExprAST *E = ParseExpression()) {
589 // Make an anonymous proto.
590 PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
591 return new FunctionAST(Proto, E);
596 /// external ::= 'extern' prototype
597 static PrototypeAST *ParseExtern() {
598 getNextToken(); // eat extern.
599 return ParsePrototype();
602 //===----------------------------------------------------------------------===//
604 //===----------------------------------------------------------------------===//
606 static Module *TheModule;
607 static IRBuilder<> Builder(getGlobalContext());
608 static std::map<std::string, AllocaInst*> NamedValues;
609 static FunctionPassManager *TheFPM;
611 Value *ErrorV(const char *Str) { Error(Str); return 0; }
613 /// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
614 /// the function. This is used for mutable variables etc.
615 static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
616 const std::string &VarName) {
617 IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
618 TheFunction->getEntryBlock().begin());
619 return TmpB.CreateAlloca(Type::DoubleTy, 0, VarName.c_str());
623 Value *NumberExprAST::Codegen() {
624 return getGlobalContext().getConstantFP(APFloat(Val));
627 Value *VariableExprAST::Codegen() {
628 // Look this variable up in the function.
629 Value *V = NamedValues[Name];
630 if (V == 0) return ErrorV("Unknown variable name");
633 return Builder.CreateLoad(V, Name.c_str());
636 Value *UnaryExprAST::Codegen() {
637 Value *OperandV = Operand->Codegen();
638 if (OperandV == 0) return 0;
640 Function *F = TheModule->getFunction(std::string("unary")+Opcode);
642 return ErrorV("Unknown unary operator");
644 return Builder.CreateCall(F, OperandV, "unop");
648 Value *BinaryExprAST::Codegen() {
649 // Special case '=' because we don't want to emit the LHS as an expression.
651 // Assignment requires the LHS to be an identifier.
652 VariableExprAST *LHSE = dynamic_cast<VariableExprAST*>(LHS);
654 return ErrorV("destination of '=' must be a variable");
656 Value *Val = RHS->Codegen();
657 if (Val == 0) return 0;
660 Value *Variable = NamedValues[LHSE->getName()];
661 if (Variable == 0) return ErrorV("Unknown variable name");
663 Builder.CreateStore(Val, Variable);
668 Value *L = LHS->Codegen();
669 Value *R = RHS->Codegen();
670 if (L == 0 || R == 0) return 0;
673 case '+': return Builder.CreateAdd(L, R, "addtmp");
674 case '-': return Builder.CreateSub(L, R, "subtmp");
675 case '*': return Builder.CreateMul(L, R, "multmp");
677 L = Builder.CreateFCmpULT(L, R, "cmptmp");
678 // Convert bool 0/1 to double 0.0 or 1.0
679 return Builder.CreateUIToFP(L, Type::DoubleTy, "booltmp");
683 // If it wasn't a builtin binary operator, it must be a user defined one. Emit
685 Function *F = TheModule->getFunction(std::string("binary")+Op);
686 assert(F && "binary operator not found!");
688 Value *Ops[] = { L, R };
689 return Builder.CreateCall(F, Ops, Ops+2, "binop");
692 Value *CallExprAST::Codegen() {
693 // Look up the name in the global module table.
694 Function *CalleeF = TheModule->getFunction(Callee);
696 return ErrorV("Unknown function referenced");
698 // If argument mismatch error.
699 if (CalleeF->arg_size() != Args.size())
700 return ErrorV("Incorrect # arguments passed");
702 std::vector<Value*> ArgsV;
703 for (unsigned i = 0, e = Args.size(); i != e; ++i) {
704 ArgsV.push_back(Args[i]->Codegen());
705 if (ArgsV.back() == 0) return 0;
708 return Builder.CreateCall(CalleeF, ArgsV.begin(), ArgsV.end(), "calltmp");
711 Value *IfExprAST::Codegen() {
712 Value *CondV = Cond->Codegen();
713 if (CondV == 0) return 0;
715 // Convert condition to a bool by comparing equal to 0.0.
716 CondV = Builder.CreateFCmpONE(CondV,
717 getGlobalContext().getConstantFP(APFloat(0.0)),
720 Function *TheFunction = Builder.GetInsertBlock()->getParent();
722 // Create blocks for the then and else cases. Insert the 'then' block at the
723 // end of the function.
724 BasicBlock *ThenBB = BasicBlock::Create("then", TheFunction);
725 BasicBlock *ElseBB = BasicBlock::Create("else");
726 BasicBlock *MergeBB = BasicBlock::Create("ifcont");
728 Builder.CreateCondBr(CondV, ThenBB, ElseBB);
731 Builder.SetInsertPoint(ThenBB);
733 Value *ThenV = Then->Codegen();
734 if (ThenV == 0) return 0;
736 Builder.CreateBr(MergeBB);
737 // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
738 ThenBB = Builder.GetInsertBlock();
741 TheFunction->getBasicBlockList().push_back(ElseBB);
742 Builder.SetInsertPoint(ElseBB);
744 Value *ElseV = Else->Codegen();
745 if (ElseV == 0) return 0;
747 Builder.CreateBr(MergeBB);
748 // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
749 ElseBB = Builder.GetInsertBlock();
752 TheFunction->getBasicBlockList().push_back(MergeBB);
753 Builder.SetInsertPoint(MergeBB);
754 PHINode *PN = Builder.CreatePHI(Type::DoubleTy, "iftmp");
756 PN->addIncoming(ThenV, ThenBB);
757 PN->addIncoming(ElseV, ElseBB);
761 Value *ForExprAST::Codegen() {
763 // var = alloca double
766 // store start -> var
777 // nextvar = curvar + step
778 // store nextvar -> var
779 // br endcond, loop, endloop
782 Function *TheFunction = Builder.GetInsertBlock()->getParent();
784 // Create an alloca for the variable in the entry block.
785 AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
787 // Emit the start code first, without 'variable' in scope.
788 Value *StartVal = Start->Codegen();
789 if (StartVal == 0) return 0;
791 // Store the value into the alloca.
792 Builder.CreateStore(StartVal, Alloca);
794 // Make the new basic block for the loop header, inserting after current
796 BasicBlock *LoopBB = BasicBlock::Create("loop", TheFunction);
798 // Insert an explicit fall through from the current block to the LoopBB.
799 Builder.CreateBr(LoopBB);
801 // Start insertion in LoopBB.
802 Builder.SetInsertPoint(LoopBB);
804 // Within the loop, the variable is defined equal to the PHI node. If it
805 // shadows an existing variable, we have to restore it, so save it now.
806 AllocaInst *OldVal = NamedValues[VarName];
807 NamedValues[VarName] = Alloca;
809 // Emit the body of the loop. This, like any other expr, can change the
810 // current BB. Note that we ignore the value computed by the body, but don't
812 if (Body->Codegen() == 0)
815 // Emit the step value.
818 StepVal = Step->Codegen();
819 if (StepVal == 0) return 0;
821 // If not specified, use 1.0.
822 StepVal = getGlobalContext().getConstantFP(APFloat(1.0));
825 // Compute the end condition.
826 Value *EndCond = End->Codegen();
827 if (EndCond == 0) return EndCond;
829 // Reload, increment, and restore the alloca. This handles the case where
830 // the body of the loop mutates the variable.
831 Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
832 Value *NextVar = Builder.CreateAdd(CurVar, StepVal, "nextvar");
833 Builder.CreateStore(NextVar, Alloca);
835 // Convert condition to a bool by comparing equal to 0.0.
836 EndCond = Builder.CreateFCmpONE(EndCond,
837 getGlobalContext().getConstantFP(APFloat(0.0)),
840 // Create the "after loop" block and insert it.
841 BasicBlock *AfterBB = BasicBlock::Create("afterloop", TheFunction);
843 // Insert the conditional branch into the end of LoopEndBB.
844 Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
846 // Any new code will be inserted in AfterBB.
847 Builder.SetInsertPoint(AfterBB);
849 // Restore the unshadowed variable.
851 NamedValues[VarName] = OldVal;
853 NamedValues.erase(VarName);
856 // for expr always returns 0.0.
857 return TheFunction->getContext()->getNullValue(Type::DoubleTy);
860 Value *VarExprAST::Codegen() {
861 std::vector<AllocaInst *> OldBindings;
863 Function *TheFunction = Builder.GetInsertBlock()->getParent();
865 // Register all variables and emit their initializer.
866 for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
867 const std::string &VarName = VarNames[i].first;
868 ExprAST *Init = VarNames[i].second;
870 // Emit the initializer before adding the variable to scope, this prevents
871 // the initializer from referencing the variable itself, and permits stuff
874 // var a = a in ... # refers to outer 'a'.
877 InitVal = Init->Codegen();
878 if (InitVal == 0) return 0;
879 } else { // If not specified, use 0.0.
880 InitVal = getGlobalContext().getConstantFP(APFloat(0.0));
883 AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
884 Builder.CreateStore(InitVal, Alloca);
886 // Remember the old variable binding so that we can restore the binding when
888 OldBindings.push_back(NamedValues[VarName]);
890 // Remember this binding.
891 NamedValues[VarName] = Alloca;
894 // Codegen the body, now that all vars are in scope.
895 Value *BodyVal = Body->Codegen();
896 if (BodyVal == 0) return 0;
898 // Pop all our variables from scope.
899 for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
900 NamedValues[VarNames[i].first] = OldBindings[i];
902 // Return the body computation.
907 Function *PrototypeAST::Codegen() {
908 // Make the function type: double(double,double) etc.
909 std::vector<const Type*> Doubles(Args.size(), Type::DoubleTy);
911 getGlobalContext().getFunctionType(Type::DoubleTy, Doubles, false);
913 Function *F = Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
915 // If F conflicted, there was already something named 'Name'. If it has a
916 // body, don't allow redefinition or reextern.
917 if (F->getName() != Name) {
918 // Delete the one we just made and get the existing one.
919 F->eraseFromParent();
920 F = TheModule->getFunction(Name);
922 // If F already has a body, reject this.
924 ErrorF("redefinition of function");
928 // If F took a different number of args, reject.
929 if (F->arg_size() != Args.size()) {
930 ErrorF("redefinition of function with different # args");
935 // Set names for all arguments.
937 for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
939 AI->setName(Args[Idx]);
944 /// CreateArgumentAllocas - Create an alloca for each argument and register the
945 /// argument in the symbol table so that references to it will succeed.
946 void PrototypeAST::CreateArgumentAllocas(Function *F) {
947 Function::arg_iterator AI = F->arg_begin();
948 for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
949 // Create an alloca for this variable.
950 AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
952 // Store the initial value into the alloca.
953 Builder.CreateStore(AI, Alloca);
955 // Add arguments to variable symbol table.
956 NamedValues[Args[Idx]] = Alloca;
961 Function *FunctionAST::Codegen() {
964 Function *TheFunction = Proto->Codegen();
965 if (TheFunction == 0)
968 // If this is an operator, install it.
969 if (Proto->isBinaryOp())
970 BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
972 // Create a new basic block to start insertion into.
973 BasicBlock *BB = BasicBlock::Create("entry", TheFunction);
974 Builder.SetInsertPoint(BB);
976 // Add all arguments to the symbol table and create their allocas.
977 Proto->CreateArgumentAllocas(TheFunction);
979 if (Value *RetVal = Body->Codegen()) {
980 // Finish off the function.
981 Builder.CreateRet(RetVal);
983 // Validate the generated code, checking for consistency.
984 verifyFunction(*TheFunction);
986 // Optimize the function.
987 TheFPM->run(*TheFunction);
992 // Error reading body, remove function.
993 TheFunction->eraseFromParent();
995 if (Proto->isBinaryOp())
996 BinopPrecedence.erase(Proto->getOperatorName());
1000 //===----------------------------------------------------------------------===//
1001 // Top-Level parsing and JIT Driver
1002 //===----------------------------------------------------------------------===//
1004 static ExecutionEngine *TheExecutionEngine;
1006 static void HandleDefinition() {
1007 if (FunctionAST *F = ParseDefinition()) {
1008 if (Function *LF = F->Codegen()) {
1009 fprintf(stderr, "Read function definition:");
1013 // Skip token for error recovery.
1018 static void HandleExtern() {
1019 if (PrototypeAST *P = ParseExtern()) {
1020 if (Function *F = P->Codegen()) {
1021 fprintf(stderr, "Read extern: ");
1025 // Skip token for error recovery.
1030 static void HandleTopLevelExpression() {
1031 // Evaluate a top level expression into an anonymous function.
1032 if (FunctionAST *F = ParseTopLevelExpr()) {
1033 if (Function *LF = F->Codegen()) {
1034 // JIT the function, returning a function pointer.
1035 void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
1037 // Cast it to the right type (takes no arguments, returns a double) so we
1038 // can call it as a native function.
1039 double (*FP)() = (double (*)())(intptr_t)FPtr;
1040 fprintf(stderr, "Evaluated to %f\n", FP());
1043 // Skip token for error recovery.
1048 /// top ::= definition | external | expression | ';'
1049 static void MainLoop() {
1051 fprintf(stderr, "ready> ");
1053 case tok_eof: return;
1054 case ';': getNextToken(); break; // ignore top level semicolons.
1055 case tok_def: HandleDefinition(); break;
1056 case tok_extern: HandleExtern(); break;
1057 default: HandleTopLevelExpression(); break;
1064 //===----------------------------------------------------------------------===//
1065 // "Library" functions that can be "extern'd" from user code.
1066 //===----------------------------------------------------------------------===//
1068 /// putchard - putchar that takes a double and returns 0.
1070 double putchard(double X) {
1075 /// printd - printf that takes a double prints it as "%f\n", returning 0.
1077 double printd(double X) {
1082 //===----------------------------------------------------------------------===//
1083 // Main driver code.
1084 //===----------------------------------------------------------------------===//
1087 InitializeNativeTarget();
1088 LLVMContext &Context = getGlobalContext();
1090 // Install standard binary operators.
1091 // 1 is lowest precedence.
1092 BinopPrecedence['='] = 2;
1093 BinopPrecedence['<'] = 10;
1094 BinopPrecedence['+'] = 20;
1095 BinopPrecedence['-'] = 20;
1096 BinopPrecedence['*'] = 40; // highest.
1098 // Prime the first token.
1099 fprintf(stderr, "ready> ");
1102 // Make the module, which holds all the code.
1103 TheModule = new Module("my cool jit", Context);
1106 TheExecutionEngine = ExecutionEngine::create(TheModule);
1109 ExistingModuleProvider OurModuleProvider(TheModule);
1110 FunctionPassManager OurFPM(&OurModuleProvider);
1112 // Set up the optimizer pipeline. Start with registering info about how the
1113 // target lays out data structures.
1114 OurFPM.add(new TargetData(*TheExecutionEngine->getTargetData()));
1115 // Promote allocas to registers.
1116 OurFPM.add(createPromoteMemoryToRegisterPass());
1117 // Do simple "peephole" optimizations and bit-twiddling optzns.
1118 OurFPM.add(createInstructionCombiningPass());
1119 // Reassociate expressions.
1120 OurFPM.add(createReassociatePass());
1121 // Eliminate Common SubExpressions.
1122 OurFPM.add(createGVNPass());
1123 // Simplify the control flow graph (deleting unreachable blocks, etc).
1124 OurFPM.add(createCFGSimplificationPass());
1126 // Set the global so the code gen can use this.
1129 // Run the main "interpreter loop" now.
1134 // Print out all of the generated code.
1137 } // Free module provider (and thus the module) and pass manager.