1 #include "llvm/Analysis/Passes.h"
2 #include "llvm/Analysis/Verifier.h"
3 #include "llvm/ExecutionEngine/ExecutionEngine.h"
4 #include "llvm/ExecutionEngine/JIT.h"
5 #include "llvm/IR/DataLayout.h"
6 #include "llvm/IR/DerivedTypes.h"
7 #include "llvm/IR/IRBuilder.h"
8 #include "llvm/IR/LLVMContext.h"
9 #include "llvm/IR/Module.h"
10 #include "llvm/PassManager.h"
11 #include "llvm/Support/TargetSelect.h"
12 #include "llvm/Transforms/Scalar.h"
19 //===----------------------------------------------------------------------===//
21 //===----------------------------------------------------------------------===//
23 // The lexer returns tokens [0-255] if it is an unknown character, otherwise one
24 // of these for known things.
29 tok_def = -2, tok_extern = -3,
32 tok_identifier = -4, tok_number = -5
35 static std::string IdentifierStr; // Filled in if tok_identifier
36 static double NumVal; // Filled in if tok_number
38 /// gettok - Return the next token from standard input.
40 static int LastChar = ' ';
42 // Skip any whitespace.
43 while (isspace(LastChar))
46 if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
47 IdentifierStr = LastChar;
48 while (isalnum((LastChar = getchar())))
49 IdentifierStr += LastChar;
51 if (IdentifierStr == "def") return tok_def;
52 if (IdentifierStr == "extern") return tok_extern;
53 return tok_identifier;
56 if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
61 } while (isdigit(LastChar) || LastChar == '.');
63 NumVal = strtod(NumStr.c_str(), 0);
67 if (LastChar == '#') {
68 // Comment until end of line.
69 do LastChar = getchar();
70 while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
76 // Check for end of file. Don't eat the EOF.
80 // Otherwise, just return the character as its ascii value.
81 int ThisChar = LastChar;
86 //===----------------------------------------------------------------------===//
87 // Abstract Syntax Tree (aka Parse Tree)
88 //===----------------------------------------------------------------------===//
90 /// ExprAST - Base class for all expression nodes.
94 virtual Value *Codegen() = 0;
97 /// NumberExprAST - Expression class for numeric literals like "1.0".
98 class NumberExprAST : public ExprAST {
101 NumberExprAST(double val) : Val(val) {}
102 virtual Value *Codegen();
105 /// VariableExprAST - Expression class for referencing a variable, like "a".
106 class VariableExprAST : public ExprAST {
109 VariableExprAST(const std::string &name) : Name(name) {}
110 virtual Value *Codegen();
113 /// BinaryExprAST - Expression class for a binary operator.
114 class BinaryExprAST : public ExprAST {
118 BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
119 : Op(op), LHS(lhs), RHS(rhs) {}
120 virtual Value *Codegen();
123 /// CallExprAST - Expression class for function calls.
124 class CallExprAST : public ExprAST {
126 std::vector<ExprAST*> Args;
128 CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
129 : Callee(callee), Args(args) {}
130 virtual Value *Codegen();
133 /// PrototypeAST - This class represents the "prototype" for a function,
134 /// which captures its name, and its argument names (thus implicitly the number
135 /// of arguments the function takes).
138 std::vector<std::string> Args;
140 PrototypeAST(const std::string &name, const std::vector<std::string> &args)
141 : Name(name), Args(args) {}
146 /// FunctionAST - This class represents a function definition itself.
151 FunctionAST(PrototypeAST *proto, ExprAST *body)
152 : Proto(proto), Body(body) {}
157 //===----------------------------------------------------------------------===//
159 //===----------------------------------------------------------------------===//
161 /// CurTok/getNextToken - Provide a simple token buffer. CurTok is the current
162 /// token the parser is looking at. getNextToken reads another token from the
163 /// lexer and updates CurTok with its results.
165 static int getNextToken() {
166 return CurTok = gettok();
169 /// BinopPrecedence - This holds the precedence for each binary operator that is
171 static std::map<char, int> BinopPrecedence;
173 /// GetTokPrecedence - Get the precedence of the pending binary operator token.
174 static int GetTokPrecedence() {
175 if (!isascii(CurTok))
178 // Make sure it's a declared binop.
179 int TokPrec = BinopPrecedence[CurTok];
180 if (TokPrec <= 0) return -1;
184 /// Error* - These are little helper functions for error handling.
185 ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
186 PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
187 FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
189 static ExprAST *ParseExpression();
193 /// ::= identifier '(' expression* ')'
194 static ExprAST *ParseIdentifierExpr() {
195 std::string IdName = IdentifierStr;
197 getNextToken(); // eat identifier.
199 if (CurTok != '(') // Simple variable ref.
200 return new VariableExprAST(IdName);
203 getNextToken(); // eat (
204 std::vector<ExprAST*> Args;
207 ExprAST *Arg = ParseExpression();
211 if (CurTok == ')') break;
214 return Error("Expected ')' or ',' in argument list");
222 return new CallExprAST(IdName, Args);
225 /// numberexpr ::= number
226 static ExprAST *ParseNumberExpr() {
227 ExprAST *Result = new NumberExprAST(NumVal);
228 getNextToken(); // consume the number
232 /// parenexpr ::= '(' expression ')'
233 static ExprAST *ParseParenExpr() {
234 getNextToken(); // eat (.
235 ExprAST *V = ParseExpression();
239 return Error("expected ')'");
240 getNextToken(); // eat ).
245 /// ::= identifierexpr
248 static ExprAST *ParsePrimary() {
250 default: return Error("unknown token when expecting an expression");
251 case tok_identifier: return ParseIdentifierExpr();
252 case tok_number: return ParseNumberExpr();
253 case '(': return ParseParenExpr();
258 /// ::= ('+' primary)*
259 static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
260 // If this is a binop, find its precedence.
262 int TokPrec = GetTokPrecedence();
264 // If this is a binop that binds at least as tightly as the current binop,
265 // consume it, otherwise we are done.
266 if (TokPrec < ExprPrec)
269 // Okay, we know this is a binop.
271 getNextToken(); // eat binop
273 // Parse the primary expression after the binary operator.
274 ExprAST *RHS = ParsePrimary();
277 // If BinOp binds less tightly with RHS than the operator after RHS, let
278 // the pending operator take RHS as its LHS.
279 int NextPrec = GetTokPrecedence();
280 if (TokPrec < NextPrec) {
281 RHS = ParseBinOpRHS(TokPrec+1, RHS);
282 if (RHS == 0) return 0;
286 LHS = new BinaryExprAST(BinOp, LHS, RHS);
291 /// ::= primary binoprhs
293 static ExprAST *ParseExpression() {
294 ExprAST *LHS = ParsePrimary();
297 return ParseBinOpRHS(0, LHS);
301 /// ::= id '(' id* ')'
302 static PrototypeAST *ParsePrototype() {
303 if (CurTok != tok_identifier)
304 return ErrorP("Expected function name in prototype");
306 std::string FnName = IdentifierStr;
310 return ErrorP("Expected '(' in prototype");
312 std::vector<std::string> ArgNames;
313 while (getNextToken() == tok_identifier)
314 ArgNames.push_back(IdentifierStr);
316 return ErrorP("Expected ')' in prototype");
319 getNextToken(); // eat ')'.
321 return new PrototypeAST(FnName, ArgNames);
324 /// definition ::= 'def' prototype expression
325 static FunctionAST *ParseDefinition() {
326 getNextToken(); // eat def.
327 PrototypeAST *Proto = ParsePrototype();
328 if (Proto == 0) return 0;
330 if (ExprAST *E = ParseExpression())
331 return new FunctionAST(Proto, E);
335 /// toplevelexpr ::= expression
336 static FunctionAST *ParseTopLevelExpr() {
337 if (ExprAST *E = ParseExpression()) {
338 // Make an anonymous proto.
339 PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
340 return new FunctionAST(Proto, E);
345 /// external ::= 'extern' prototype
346 static PrototypeAST *ParseExtern() {
347 getNextToken(); // eat extern.
348 return ParsePrototype();
351 //===----------------------------------------------------------------------===//
353 //===----------------------------------------------------------------------===//
355 static Module *TheModule;
356 static IRBuilder<> Builder(getGlobalContext());
357 static std::map<std::string, Value*> NamedValues;
358 static FunctionPassManager *TheFPM;
360 Value *ErrorV(const char *Str) { Error(Str); return 0; }
362 Value *NumberExprAST::Codegen() {
363 return ConstantFP::get(getGlobalContext(), APFloat(Val));
366 Value *VariableExprAST::Codegen() {
367 // Look this variable up in the function.
368 Value *V = NamedValues[Name];
369 return V ? V : ErrorV("Unknown variable name");
372 Value *BinaryExprAST::Codegen() {
373 Value *L = LHS->Codegen();
374 Value *R = RHS->Codegen();
375 if (L == 0 || R == 0) return 0;
378 case '+': return Builder.CreateFAdd(L, R, "addtmp");
379 case '-': return Builder.CreateFSub(L, R, "subtmp");
380 case '*': return Builder.CreateFMul(L, R, "multmp");
382 L = Builder.CreateFCmpULT(L, R, "cmptmp");
383 // Convert bool 0/1 to double 0.0 or 1.0
384 return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
386 default: return ErrorV("invalid binary operator");
390 Value *CallExprAST::Codegen() {
391 // Look up the name in the global module table.
392 Function *CalleeF = TheModule->getFunction(Callee);
394 return ErrorV("Unknown function referenced");
396 // If argument mismatch error.
397 if (CalleeF->arg_size() != Args.size())
398 return ErrorV("Incorrect # arguments passed");
400 std::vector<Value*> ArgsV;
401 for (unsigned i = 0, e = Args.size(); i != e; ++i) {
402 ArgsV.push_back(Args[i]->Codegen());
403 if (ArgsV.back() == 0) return 0;
406 return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
409 Function *PrototypeAST::Codegen() {
410 // Make the function type: double(double,double) etc.
411 std::vector<Type*> Doubles(Args.size(),
412 Type::getDoubleTy(getGlobalContext()));
413 FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
416 Function *F = Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
418 // If F conflicted, there was already something named 'Name'. If it has a
419 // body, don't allow redefinition or reextern.
420 if (F->getName() != Name) {
421 // Delete the one we just made and get the existing one.
422 F->eraseFromParent();
423 F = TheModule->getFunction(Name);
425 // If F already has a body, reject this.
427 ErrorF("redefinition of function");
431 // If F took a different number of args, reject.
432 if (F->arg_size() != Args.size()) {
433 ErrorF("redefinition of function with different # args");
438 // Set names for all arguments.
440 for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
442 AI->setName(Args[Idx]);
444 // Add arguments to variable symbol table.
445 NamedValues[Args[Idx]] = AI;
451 Function *FunctionAST::Codegen() {
454 Function *TheFunction = Proto->Codegen();
455 if (TheFunction == 0)
458 // Create a new basic block to start insertion into.
459 BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
460 Builder.SetInsertPoint(BB);
462 if (Value *RetVal = Body->Codegen()) {
463 // Finish off the function.
464 Builder.CreateRet(RetVal);
466 // Validate the generated code, checking for consistency.
467 verifyFunction(*TheFunction);
469 // Optimize the function.
470 TheFPM->run(*TheFunction);
475 // Error reading body, remove function.
476 TheFunction->eraseFromParent();
480 //===----------------------------------------------------------------------===//
481 // Top-Level parsing and JIT Driver
482 //===----------------------------------------------------------------------===//
484 static ExecutionEngine *TheExecutionEngine;
486 static void HandleDefinition() {
487 if (FunctionAST *F = ParseDefinition()) {
488 if (Function *LF = F->Codegen()) {
489 fprintf(stderr, "Read function definition:");
493 // Skip token for error recovery.
498 static void HandleExtern() {
499 if (PrototypeAST *P = ParseExtern()) {
500 if (Function *F = P->Codegen()) {
501 fprintf(stderr, "Read extern: ");
505 // Skip token for error recovery.
510 static void HandleTopLevelExpression() {
511 // Evaluate a top-level expression into an anonymous function.
512 if (FunctionAST *F = ParseTopLevelExpr()) {
513 if (Function *LF = F->Codegen()) {
514 // JIT the function, returning a function pointer.
515 void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
517 // Cast it to the right type (takes no arguments, returns a double) so we
518 // can call it as a native function.
519 double (*FP)() = (double (*)())(intptr_t)FPtr;
520 fprintf(stderr, "Evaluated to %f\n", FP());
523 // Skip token for error recovery.
528 /// top ::= definition | external | expression | ';'
529 static void MainLoop() {
531 fprintf(stderr, "ready> ");
533 case tok_eof: return;
534 case ';': getNextToken(); break; // ignore top-level semicolons.
535 case tok_def: HandleDefinition(); break;
536 case tok_extern: HandleExtern(); break;
537 default: HandleTopLevelExpression(); break;
542 //===----------------------------------------------------------------------===//
543 // "Library" functions that can be "extern'd" from user code.
544 //===----------------------------------------------------------------------===//
546 /// putchard - putchar that takes a double and returns 0.
548 double putchard(double X) {
553 //===----------------------------------------------------------------------===//
555 //===----------------------------------------------------------------------===//
558 InitializeNativeTarget();
559 LLVMContext &Context = getGlobalContext();
561 // Install standard binary operators.
562 // 1 is lowest precedence.
563 BinopPrecedence['<'] = 10;
564 BinopPrecedence['+'] = 20;
565 BinopPrecedence['-'] = 20;
566 BinopPrecedence['*'] = 40; // highest.
568 // Prime the first token.
569 fprintf(stderr, "ready> ");
572 // Make the module, which holds all the code.
573 TheModule = new Module("my cool jit", Context);
575 // Create the JIT. This takes ownership of the module.
577 TheExecutionEngine = EngineBuilder(TheModule).setErrorStr(&ErrStr).create();
578 if (!TheExecutionEngine) {
579 fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
583 FunctionPassManager OurFPM(TheModule);
585 // Set up the optimizer pipeline. Start with registering info about how the
586 // target lays out data structures.
587 OurFPM.add(new DataLayout(*TheExecutionEngine->getDataLayout()));
588 // Provide basic AliasAnalysis support for GVN.
589 OurFPM.add(createBasicAliasAnalysisPass());
590 // Do simple "peephole" optimizations and bit-twiddling optzns.
591 OurFPM.add(createInstructionCombiningPass());
592 // Reassociate expressions.
593 OurFPM.add(createReassociatePass());
594 // Eliminate Common SubExpressions.
595 OurFPM.add(createGVNPass());
596 // Simplify the control flow graph (deleting unreachable blocks, etc).
597 OurFPM.add(createCFGSimplificationPass());
599 OurFPM.doInitialization();
601 // Set the global so the code gen can use this.
604 // Run the main "interpreter loop" now.
609 // Print out all of the generated code.