1 #define MINIMAL_STDERR_OUTPUT
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/DataLayout.h"
8 #include "llvm/IR/DerivedTypes.h"
9 #include "llvm/IR/IRBuilder.h"
10 #include "llvm/IR/LLVMContext.h"
11 #include "llvm/IR/LegacyPassManager.h"
12 #include "llvm/IR/Module.h"
13 #include "llvm/IR/Verifier.h"
14 #include "llvm/Support/TargetSelect.h"
15 #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 //===----------------------------------------------------------------------===//
607 // Quick and dirty hack
608 //===----------------------------------------------------------------------===//
610 // FIXME: Obviously we can do better than this
611 std::string GenerateUniqueName(const char *root)
615 sprintf(s, "%s%d", root, i++);
620 std::string MakeLegalFunctionName(std::string Name)
624 return GenerateUniqueName("anon_func_");
626 // Start with what we have
629 // Look for a numberic first character
630 if (NewName.find_first_of("0123456789") == 0) {
631 NewName.insert(0, 1, 'n');
634 // Replace illegal characters with their ASCII equivalent
635 std::string legal_elements = "_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
637 while ((pos = NewName.find_first_not_of(legal_elements)) != std::string::npos) {
638 char old_c = NewName.at(pos);
640 sprintf(new_str, "%d", (int)old_c);
641 NewName = NewName.replace(pos, 1, new_str);
647 //===----------------------------------------------------------------------===//
648 // MCJIT helper class
649 //===----------------------------------------------------------------------===//
654 MCJITHelper(LLVMContext& C) : Context(C), OpenModule(NULL) {}
657 Function *getFunction(const std::string FnName);
658 Module *getModuleForNewFunction();
659 void *getPointerToFunction(Function* F);
660 void *getPointerToNamedFunction(const std::string &Name);
661 ExecutionEngine *compileModule(Module *M);
662 void closeCurrentModule();
666 typedef std::vector<Module*> ModuleVector;
668 LLVMContext &Context;
670 ModuleVector Modules;
671 std::map<Module *, ExecutionEngine *> EngineMap;
674 class HelpingMemoryManager : public SectionMemoryManager
676 HelpingMemoryManager(const HelpingMemoryManager&) = delete;
677 void operator=(const HelpingMemoryManager&) = delete;
680 HelpingMemoryManager(MCJITHelper *Helper) : MasterHelper(Helper) {}
681 virtual ~HelpingMemoryManager() {}
683 /// This method returns the address of the specified function.
684 /// Our implementation will attempt to find functions in other
685 /// modules associated with the MCJITHelper to cross link functions
686 /// from one generated module to another.
688 /// If \p AbortOnFailure is false and no function with the given name is
689 /// found, this function returns a null pointer. Otherwise, it prints a
690 /// message to stderr and aborts.
691 virtual void *getPointerToNamedFunction(const std::string &Name,
692 bool AbortOnFailure = true);
694 MCJITHelper *MasterHelper;
697 void *HelpingMemoryManager::getPointerToNamedFunction(const std::string &Name,
700 // Try the standard symbol resolution first, but ask it not to abort.
701 void *pfn = SectionMemoryManager::getPointerToNamedFunction(Name, false);
705 pfn = MasterHelper->getPointerToNamedFunction(Name);
706 if (!pfn && AbortOnFailure)
707 report_fatal_error("Program used external function '" + Name +
708 "' which could not be resolved!");
712 MCJITHelper::~MCJITHelper()
714 // Walk the vector of modules.
715 ModuleVector::iterator it, end;
716 for (it = Modules.begin(), end = Modules.end();
718 // See if we have an execution engine for this module.
719 std::map<Module*, ExecutionEngine*>::iterator mapIt = EngineMap.find(*it);
720 // If we have an EE, the EE owns the module so just delete the EE.
721 if (mapIt != EngineMap.end()) {
722 delete mapIt->second;
724 // Otherwise, we still own the module. Delete it now.
730 Function *MCJITHelper::getFunction(const std::string FnName) {
731 ModuleVector::iterator begin = Modules.begin();
732 ModuleVector::iterator end = Modules.end();
733 ModuleVector::iterator it;
734 for (it = begin; it != end; ++it) {
735 Function *F = (*it)->getFunction(FnName);
737 if (*it == OpenModule)
740 assert(OpenModule != NULL);
742 // This function is in a module that has already been JITed.
743 // We need to generate a new prototype for external linkage.
744 Function *PF = OpenModule->getFunction(FnName);
745 if (PF && !PF->empty()) {
746 ErrorF("redefinition of function across modules");
750 // If we don't have a prototype yet, create one.
752 PF = Function::Create(F->getFunctionType(),
753 Function::ExternalLinkage,
762 Module *MCJITHelper::getModuleForNewFunction() {
763 // If we have a Module that hasn't been JITed, use that.
767 // Otherwise create a new Module.
768 std::string ModName = GenerateUniqueName("mcjit_module_");
769 Module *M = new Module(ModName, Context);
770 Modules.push_back(M);
775 void *MCJITHelper::getPointerToFunction(Function* F) {
776 // Look for this function in an existing module
777 ModuleVector::iterator begin = Modules.begin();
778 ModuleVector::iterator end = Modules.end();
779 ModuleVector::iterator it;
780 std::string FnName = F->getName();
781 for (it = begin; it != end; ++it) {
782 Function *MF = (*it)->getFunction(FnName);
784 std::map<Module*, ExecutionEngine*>::iterator eeIt = EngineMap.find(*it);
785 if (eeIt != EngineMap.end()) {
786 void *P = eeIt->second->getPointerToFunction(F);
790 ExecutionEngine *EE = compileModule(*it);
791 void *P = EE->getPointerToFunction(F);
800 void MCJITHelper::closeCurrentModule() {
804 ExecutionEngine *MCJITHelper::compileModule(Module *M) {
806 closeCurrentModule();
809 ExecutionEngine *NewEngine = EngineBuilder(M)
810 .setErrorStr(&ErrStr)
811 .setMCJITMemoryManager(new HelpingMemoryManager(this))
814 fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
818 // Create a function pass manager for this engine
819 FunctionPassManager *FPM = new FunctionPassManager(M);
821 // Set up the optimizer pipeline. Start with registering info about how the
822 // target lays out data structures.
823 FPM->add(new DataLayout(*NewEngine->getDataLayout()));
824 // Provide basic AliasAnalysis support for GVN.
825 FPM->add(createBasicAliasAnalysisPass());
826 // Promote allocas to registers.
827 FPM->add(createPromoteMemoryToRegisterPass());
828 // Do simple "peephole" optimizations and bit-twiddling optzns.
829 FPM->add(createInstructionCombiningPass());
830 // Reassociate expressions.
831 FPM->add(createReassociatePass());
832 // Eliminate Common SubExpressions.
833 FPM->add(createGVNPass());
834 // Simplify the control flow graph (deleting unreachable blocks, etc).
835 FPM->add(createCFGSimplificationPass());
836 FPM->doInitialization();
838 // For each function in the module
840 Module::iterator end = M->end();
841 for (it = M->begin(); it != end; ++it) {
842 // Run the FPM on this function
846 // We don't need this anymore
850 EngineMap[M] = NewEngine;
851 NewEngine->finalizeObject();
856 void *MCJITHelper::getPointerToNamedFunction(const std::string &Name)
858 // Look for the functions in our modules, compiling only as necessary
859 ModuleVector::iterator begin = Modules.begin();
860 ModuleVector::iterator end = Modules.end();
861 ModuleVector::iterator it;
862 for (it = begin; it != end; ++it) {
863 Function *F = (*it)->getFunction(Name);
864 if (F && !F->empty()) {
865 std::map<Module*, ExecutionEngine*>::iterator eeIt = EngineMap.find(*it);
866 if (eeIt != EngineMap.end()) {
867 void *P = eeIt->second->getPointerToFunction(F);
871 ExecutionEngine *EE = compileModule(*it);
872 void *P = EE->getPointerToFunction(F);
881 void MCJITHelper::dump()
883 ModuleVector::iterator begin = Modules.begin();
884 ModuleVector::iterator end = Modules.end();
885 ModuleVector::iterator it;
886 for (it = begin; it != end; ++it)
890 //===----------------------------------------------------------------------===//
892 //===----------------------------------------------------------------------===//
894 static MCJITHelper *TheHelper;
895 static IRBuilder<> Builder(getGlobalContext());
896 static std::map<std::string, AllocaInst*> NamedValues;
898 Value *ErrorV(const char *Str) { Error(Str); return 0; }
900 /// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
901 /// the function. This is used for mutable variables etc.
902 static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
903 const std::string &VarName) {
904 IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
905 TheFunction->getEntryBlock().begin());
906 return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
910 Value *NumberExprAST::Codegen() {
911 return ConstantFP::get(getGlobalContext(), APFloat(Val));
914 Value *VariableExprAST::Codegen() {
915 // Look this variable up in the function.
916 Value *V = NamedValues[Name];
918 sprintf(ErrStr, "Unknown variable name %s", Name.c_str());
919 if (V == 0) return ErrorV(ErrStr);
922 return Builder.CreateLoad(V, Name.c_str());
925 Value *UnaryExprAST::Codegen() {
926 Value *OperandV = Operand->Codegen();
927 if (OperandV == 0) return 0;
929 Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("unary")+Opcode));
931 return ErrorV("Unknown unary operator");
933 return Builder.CreateCall(F, OperandV, "unop");
936 Value *BinaryExprAST::Codegen() {
937 // Special case '=' because we don't want to emit the LHS as an expression.
939 // Assignment requires the LHS to be an identifier.
940 VariableExprAST *LHSE = reinterpret_cast<VariableExprAST*>(LHS);
942 return ErrorV("destination of '=' must be a variable");
944 Value *Val = RHS->Codegen();
945 if (Val == 0) return 0;
948 Value *Variable = NamedValues[LHSE->getName()];
949 if (Variable == 0) return ErrorV("Unknown variable name");
951 Builder.CreateStore(Val, Variable);
955 Value *L = LHS->Codegen();
956 Value *R = RHS->Codegen();
957 if (L == 0 || R == 0) return 0;
960 case '+': return Builder.CreateFAdd(L, R, "addtmp");
961 case '-': return Builder.CreateFSub(L, R, "subtmp");
962 case '*': return Builder.CreateFMul(L, R, "multmp");
963 case '/': return Builder.CreateFDiv(L, R, "divtmp");
965 L = Builder.CreateFCmpULT(L, R, "cmptmp");
966 // Convert bool 0/1 to double 0.0 or 1.0
967 return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
972 // If it wasn't a builtin binary operator, it must be a user defined one. Emit
974 Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("binary")+Op));
975 assert(F && "binary operator not found!");
977 Value *Ops[] = { L, R };
978 return Builder.CreateCall(F, Ops, "binop");
981 Value *CallExprAST::Codegen() {
982 // Look up the name in the global module table.
983 Function *CalleeF = TheHelper->getFunction(Callee);
985 return ErrorV("Unknown function referenced");
987 // If argument mismatch error.
988 if (CalleeF->arg_size() != Args.size())
989 return ErrorV("Incorrect # arguments passed");
991 std::vector<Value*> ArgsV;
992 for (unsigned i = 0, e = Args.size(); i != e; ++i) {
993 ArgsV.push_back(Args[i]->Codegen());
994 if (ArgsV.back() == 0) return 0;
997 return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
1000 Value *IfExprAST::Codegen() {
1001 Value *CondV = Cond->Codegen();
1002 if (CondV == 0) return 0;
1004 // Convert condition to a bool by comparing equal to 0.0.
1005 CondV = Builder.CreateFCmpONE(CondV,
1006 ConstantFP::get(getGlobalContext(), APFloat(0.0)),
1009 Function *TheFunction = Builder.GetInsertBlock()->getParent();
1011 // Create blocks for the then and else cases. Insert the 'then' block at the
1012 // end of the function.
1013 BasicBlock *ThenBB = BasicBlock::Create(getGlobalContext(), "then", TheFunction);
1014 BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
1015 BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
1017 Builder.CreateCondBr(CondV, ThenBB, ElseBB);
1020 Builder.SetInsertPoint(ThenBB);
1022 Value *ThenV = Then->Codegen();
1023 if (ThenV == 0) return 0;
1025 Builder.CreateBr(MergeBB);
1026 // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
1027 ThenBB = Builder.GetInsertBlock();
1030 TheFunction->getBasicBlockList().push_back(ElseBB);
1031 Builder.SetInsertPoint(ElseBB);
1033 Value *ElseV = Else->Codegen();
1034 if (ElseV == 0) return 0;
1036 Builder.CreateBr(MergeBB);
1037 // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
1038 ElseBB = Builder.GetInsertBlock();
1040 // Emit merge block.
1041 TheFunction->getBasicBlockList().push_back(MergeBB);
1042 Builder.SetInsertPoint(MergeBB);
1043 PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2,
1046 PN->addIncoming(ThenV, ThenBB);
1047 PN->addIncoming(ElseV, ElseBB);
1051 Value *ForExprAST::Codegen() {
1053 // var = alloca double
1055 // start = startexpr
1056 // store start -> var
1064 // endcond = endexpr
1066 // curvar = load var
1067 // nextvar = curvar + step
1068 // store nextvar -> var
1069 // br endcond, loop, endloop
1072 Function *TheFunction = Builder.GetInsertBlock()->getParent();
1074 // Create an alloca for the variable in the entry block.
1075 AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
1077 // Emit the start code first, without 'variable' in scope.
1078 Value *StartVal = Start->Codegen();
1079 if (StartVal == 0) return 0;
1081 // Store the value into the alloca.
1082 Builder.CreateStore(StartVal, Alloca);
1084 // Make the new basic block for the loop header, inserting after current
1086 BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
1088 // Insert an explicit fall through from the current block to the LoopBB.
1089 Builder.CreateBr(LoopBB);
1091 // Start insertion in LoopBB.
1092 Builder.SetInsertPoint(LoopBB);
1094 // Within the loop, the variable is defined equal to the PHI node. If it
1095 // shadows an existing variable, we have to restore it, so save it now.
1096 AllocaInst *OldVal = NamedValues[VarName];
1097 NamedValues[VarName] = Alloca;
1099 // Emit the body of the loop. This, like any other expr, can change the
1100 // current BB. Note that we ignore the value computed by the body, but don't
1102 if (Body->Codegen() == 0)
1105 // Emit the step value.
1108 StepVal = Step->Codegen();
1109 if (StepVal == 0) return 0;
1111 // If not specified, use 1.0.
1112 StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
1115 // Compute the end condition.
1116 Value *EndCond = End->Codegen();
1117 if (EndCond == 0) return EndCond;
1119 // Reload, increment, and restore the alloca. This handles the case where
1120 // the body of the loop mutates the variable.
1121 Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
1122 Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
1123 Builder.CreateStore(NextVar, Alloca);
1125 // Convert condition to a bool by comparing equal to 0.0.
1126 EndCond = Builder.CreateFCmpONE(EndCond,
1127 ConstantFP::get(getGlobalContext(), APFloat(0.0)),
1130 // Create the "after loop" block and insert it.
1131 BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
1133 // Insert the conditional branch into the end of LoopEndBB.
1134 Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
1136 // Any new code will be inserted in AfterBB.
1137 Builder.SetInsertPoint(AfterBB);
1139 // Restore the unshadowed variable.
1141 NamedValues[VarName] = OldVal;
1143 NamedValues.erase(VarName);
1146 // for expr always returns 0.0.
1147 return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
1150 Value *VarExprAST::Codegen() {
1151 std::vector<AllocaInst *> OldBindings;
1153 Function *TheFunction = Builder.GetInsertBlock()->getParent();
1155 // Register all variables and emit their initializer.
1156 for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
1157 const std::string &VarName = VarNames[i].first;
1158 ExprAST *Init = VarNames[i].second;
1160 // Emit the initializer before adding the variable to scope, this prevents
1161 // the initializer from referencing the variable itself, and permits stuff
1164 // var a = a in ... # refers to outer 'a'.
1167 InitVal = Init->Codegen();
1168 if (InitVal == 0) return 0;
1169 } else { // If not specified, use 0.0.
1170 InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
1173 AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
1174 Builder.CreateStore(InitVal, Alloca);
1176 // Remember the old variable binding so that we can restore the binding when
1178 OldBindings.push_back(NamedValues[VarName]);
1180 // Remember this binding.
1181 NamedValues[VarName] = Alloca;
1184 // Codegen the body, now that all vars are in scope.
1185 Value *BodyVal = Body->Codegen();
1186 if (BodyVal == 0) return 0;
1188 // Pop all our variables from scope.
1189 for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
1190 NamedValues[VarNames[i].first] = OldBindings[i];
1192 // Return the body computation.
1196 Function *PrototypeAST::Codegen() {
1197 // Make the function type: double(double,double) etc.
1198 std::vector<Type*> Doubles(Args.size(),
1199 Type::getDoubleTy(getGlobalContext()));
1200 FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
1203 std::string FnName = MakeLegalFunctionName(Name);
1205 Module* M = TheHelper->getModuleForNewFunction();
1207 Function *F = Function::Create(FT, Function::ExternalLinkage, FnName, M);
1209 // If F conflicted, there was already something named 'FnName'. If it has a
1210 // body, don't allow redefinition or reextern.
1211 if (F->getName() != FnName) {
1212 // Delete the one we just made and get the existing one.
1213 F->eraseFromParent();
1214 F = M->getFunction(Name);
1216 // If F already has a body, reject this.
1218 ErrorF("redefinition of function");
1222 // If F took a different number of args, reject.
1223 if (F->arg_size() != Args.size()) {
1224 ErrorF("redefinition of function with different # args");
1229 // Set names for all arguments.
1231 for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
1233 AI->setName(Args[Idx]);
1238 /// CreateArgumentAllocas - Create an alloca for each argument and register the
1239 /// argument in the symbol table so that references to it will succeed.
1240 void PrototypeAST::CreateArgumentAllocas(Function *F) {
1241 Function::arg_iterator AI = F->arg_begin();
1242 for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
1243 // Create an alloca for this variable.
1244 AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
1246 // Store the initial value into the alloca.
1247 Builder.CreateStore(AI, Alloca);
1249 // Add arguments to variable symbol table.
1250 NamedValues[Args[Idx]] = Alloca;
1254 Function *FunctionAST::Codegen() {
1255 NamedValues.clear();
1257 Function *TheFunction = Proto->Codegen();
1258 if (TheFunction == 0)
1261 // If this is an operator, install it.
1262 if (Proto->isBinaryOp())
1263 BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
1265 // Create a new basic block to start insertion into.
1266 BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
1267 Builder.SetInsertPoint(BB);
1269 // Add all arguments to the symbol table and create their allocas.
1270 Proto->CreateArgumentAllocas(TheFunction);
1272 if (Value *RetVal = Body->Codegen()) {
1273 // Finish off the function.
1274 Builder.CreateRet(RetVal);
1276 // Validate the generated code, checking for consistency.
1277 verifyFunction(*TheFunction);
1282 // Error reading body, remove function.
1283 TheFunction->eraseFromParent();
1285 if (Proto->isBinaryOp())
1286 BinopPrecedence.erase(Proto->getOperatorName());
1290 //===----------------------------------------------------------------------===//
1291 // Top-Level parsing and JIT Driver
1292 //===----------------------------------------------------------------------===//
1294 static void HandleDefinition() {
1295 if (FunctionAST *F = ParseDefinition()) {
1296 TheHelper->closeCurrentModule();
1297 if (Function *LF = F->Codegen()) {
1298 #ifndef MINIMAL_STDERR_OUTPUT
1299 fprintf(stderr, "Read function definition:");
1304 // Skip token for error recovery.
1309 static void HandleExtern() {
1310 if (PrototypeAST *P = ParseExtern()) {
1311 if (Function *F = P->Codegen()) {
1312 #ifndef MINIMAL_STDERR_OUTPUT
1313 fprintf(stderr, "Read extern: ");
1318 // Skip token for error recovery.
1323 static void HandleTopLevelExpression() {
1324 // Evaluate a top-level expression into an anonymous function.
1325 if (FunctionAST *F = ParseTopLevelExpr()) {
1326 if (Function *LF = F->Codegen()) {
1327 // JIT the function, returning a function pointer.
1328 void *FPtr = TheHelper->getPointerToFunction(LF);
1330 // Cast it to the right type (takes no arguments, returns a double) so we
1331 // can call it as a native function.
1332 double (*FP)() = (double (*)())(intptr_t)FPtr;
1333 #ifdef MINIMAL_STDERR_OUTPUT
1336 fprintf(stderr, "Evaluated to %f\n", FP());
1340 // Skip token for error recovery.
1345 /// top ::= definition | external | expression | ';'
1346 static void MainLoop() {
1348 #ifndef MINIMAL_STDERR_OUTPUT
1349 fprintf(stderr, "ready> ");
1352 case tok_eof: return;
1353 case ';': getNextToken(); break; // ignore top-level semicolons.
1354 case tok_def: HandleDefinition(); break;
1355 case tok_extern: HandleExtern(); break;
1356 default: HandleTopLevelExpression(); break;
1361 //===----------------------------------------------------------------------===//
1362 // "Library" functions that can be "extern'd" from user code.
1363 //===----------------------------------------------------------------------===//
1365 /// putchard - putchar that takes a double and returns 0.
1367 double putchard(double X) {
1372 /// printd - printf that takes a double prints it as "%f\n", returning 0.
1374 double printd(double X) {
1385 //===----------------------------------------------------------------------===//
1386 // Main driver code.
1387 //===----------------------------------------------------------------------===//
1390 InitializeNativeTarget();
1391 InitializeNativeTargetAsmPrinter();
1392 InitializeNativeTargetAsmParser();
1393 LLVMContext &Context = getGlobalContext();
1395 // Install standard binary operators.
1396 // 1 is lowest precedence.
1397 BinopPrecedence['='] = 2;
1398 BinopPrecedence['<'] = 10;
1399 BinopPrecedence['+'] = 20;
1400 BinopPrecedence['-'] = 20;
1401 BinopPrecedence['/'] = 40;
1402 BinopPrecedence['*'] = 40; // highest.
1404 // Prime the first token.
1405 #ifndef MINIMAL_STDERR_OUTPUT
1406 fprintf(stderr, "ready> ");
1410 // Make the helper, which holds all the code.
1411 TheHelper = new MCJITHelper(Context);
1413 // Run the main "interpreter loop" now.
1416 #ifndef MINIMAL_STDERR_OUTPUT
1417 // Print out all of the generated code.