1380 lines · cpp
1#include "llvm/Analysis/Passes.h"2#include "llvm/ExecutionEngine/ExecutionEngine.h"3#include "llvm/ExecutionEngine/MCJIT.h"4#include "llvm/ExecutionEngine/SectionMemoryManager.h"5#include "llvm/IR/DataLayout.h"6#include "llvm/IR/DerivedTypes.h"7#include "llvm/IR/IRBuilder.h"8#include "llvm/IR/LLVMContext.h"9#include "llvm/IR/LegacyPassManager.h"10#include "llvm/IR/Module.h"11#include "llvm/IR/Verifier.h"12#include "llvm/Support/TargetSelect.h"13#include "llvm/Transforms/Scalar.h"14#include <cctype>15#include <cstdio>16#include <map>17#include <string>18#include <vector>19using namespace llvm;20 21//===----------------------------------------------------------------------===//22// Lexer23//===----------------------------------------------------------------------===//24 25// The lexer returns tokens [0-255] if it is an unknown character, otherwise one26// of these for known things.27enum Token {28 tok_eof = -1,29 30 // commands31 tok_def = -2, tok_extern = -3,32 33 // primary34 tok_identifier = -4, tok_number = -5,35 36 // control37 tok_if = -6, tok_then = -7, tok_else = -8,38 tok_for = -9, tok_in = -10,39 40 // operators41 tok_binary = -11, tok_unary = -12,42 43 // var definition44 tok_var = -1345};46 47static std::string IdentifierStr; // Filled in if tok_identifier48static double NumVal; // Filled in if tok_number49 50/// gettok - Return the next token from standard input.51static int gettok() {52 static int LastChar = ' ';53 54 // Skip any whitespace.55 while (isspace(LastChar))56 LastChar = getchar();57 58 if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*59 IdentifierStr = LastChar;60 while (isalnum((LastChar = getchar())))61 IdentifierStr += LastChar;62 63 if (IdentifierStr == "def") return tok_def;64 if (IdentifierStr == "extern") return tok_extern;65 if (IdentifierStr == "if") return tok_if;66 if (IdentifierStr == "then") return tok_then;67 if (IdentifierStr == "else") return tok_else;68 if (IdentifierStr == "for") return tok_for;69 if (IdentifierStr == "in") return tok_in;70 if (IdentifierStr == "binary") return tok_binary;71 if (IdentifierStr == "unary") return tok_unary;72 if (IdentifierStr == "var") return tok_var;73 return tok_identifier;74 }75 76 if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+77 std::string NumStr;78 do {79 NumStr += LastChar;80 LastChar = getchar();81 } while (isdigit(LastChar) || LastChar == '.');82 83 NumVal = strtod(NumStr.c_str(), 0);84 return tok_number;85 }86 87 if (LastChar == '#') {88 // Comment until end of line.89 do LastChar = getchar();90 while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');91 92 if (LastChar != EOF)93 return gettok();94 }95 96 // Check for end of file. Don't eat the EOF.97 if (LastChar == EOF)98 return tok_eof;99 100 // Otherwise, just return the character as its ascii value.101 int ThisChar = LastChar;102 LastChar = getchar();103 return ThisChar;104}105 106//===----------------------------------------------------------------------===//107// Abstract Syntax Tree (aka Parse Tree)108//===----------------------------------------------------------------------===//109 110/// ExprAST - Base class for all expression nodes.111class ExprAST {112public:113 virtual ~ExprAST() {}114 virtual Value *Codegen() = 0;115};116 117/// NumberExprAST - Expression class for numeric literals like "1.0".118class NumberExprAST : public ExprAST {119 double Val;120public:121 NumberExprAST(double val) : Val(val) {}122 virtual Value *Codegen();123};124 125/// VariableExprAST - Expression class for referencing a variable, like "a".126class VariableExprAST : public ExprAST {127 std::string Name;128public:129 VariableExprAST(const std::string &name) : Name(name) {}130 const std::string &getName() const { return Name; }131 virtual Value *Codegen();132};133 134/// UnaryExprAST - Expression class for a unary operator.135class UnaryExprAST : public ExprAST {136 char Opcode;137 ExprAST *Operand;138public:139 UnaryExprAST(char opcode, ExprAST *operand)140 : Opcode(opcode), Operand(operand) {}141 virtual Value *Codegen();142};143 144/// BinaryExprAST - Expression class for a binary operator.145class BinaryExprAST : public ExprAST {146 char Op;147 ExprAST *LHS, *RHS;148public:149 BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)150 : Op(op), LHS(lhs), RHS(rhs) {}151 virtual Value *Codegen();152};153 154/// CallExprAST - Expression class for function calls.155class CallExprAST : public ExprAST {156 std::string Callee;157 std::vector<ExprAST*> Args;158public:159 CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)160 : Callee(callee), Args(args) {}161 virtual Value *Codegen();162};163 164/// IfExprAST - Expression class for if/then/else.165class IfExprAST : public ExprAST {166 ExprAST *Cond, *Then, *Else;167public:168 IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)169 : Cond(cond), Then(then), Else(_else) {}170 virtual Value *Codegen();171};172 173/// ForExprAST - Expression class for for/in.174class ForExprAST : public ExprAST {175 std::string VarName;176 ExprAST *Start, *End, *Step, *Body;177public:178 ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,179 ExprAST *step, ExprAST *body)180 : VarName(varname), Start(start), End(end), Step(step), Body(body) {}181 virtual Value *Codegen();182};183 184/// VarExprAST - Expression class for var/in185class VarExprAST : public ExprAST {186 std::vector<std::pair<std::string, ExprAST*> > VarNames;187 ExprAST *Body;188public:189 VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,190 ExprAST *body)191 : VarNames(varnames), Body(body) {}192 193 virtual Value *Codegen();194};195 196/// PrototypeAST - This class represents the "prototype" for a function,197/// which captures its argument names as well as if it is an operator.198class PrototypeAST {199 std::string Name;200 std::vector<std::string> Args;201 bool isOperator;202 unsigned Precedence; // Precedence if a binary op.203public:204 PrototypeAST(const std::string &name, const std::vector<std::string> &args,205 bool isoperator = false, unsigned prec = 0)206 : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}207 208 bool isUnaryOp() const { return isOperator && Args.size() == 1; }209 bool isBinaryOp() const { return isOperator && Args.size() == 2; }210 211 char getOperatorName() const {212 assert(isUnaryOp() || isBinaryOp());213 return Name[Name.size()-1];214 }215 216 unsigned getBinaryPrecedence() const { return Precedence; }217 218 Function *Codegen();219 220 void CreateArgumentAllocas(Function *F);221};222 223/// FunctionAST - This class represents a function definition itself.224class FunctionAST {225 PrototypeAST *Proto;226 ExprAST *Body;227public:228 FunctionAST(PrototypeAST *proto, ExprAST *body)229 : Proto(proto), Body(body) {}230 231 Function *Codegen();232};233 234//===----------------------------------------------------------------------===//235// Parser236//===----------------------------------------------------------------------===//237 238/// CurTok/getNextToken - Provide a simple token buffer. CurTok is the current239/// token the parser is looking at. getNextToken reads another token from the240/// lexer and updates CurTok with its results.241static int CurTok;242static int getNextToken() {243 return CurTok = gettok();244}245 246/// BinopPrecedence - This holds the precedence for each binary operator that is247/// defined.248static std::map<char, int> BinopPrecedence;249 250/// GetTokPrecedence - Get the precedence of the pending binary operator token.251static int GetTokPrecedence() {252 if (!isascii(CurTok))253 return -1;254 255 // Make sure it's a declared binop.256 int TokPrec = BinopPrecedence[CurTok];257 if (TokPrec <= 0) return -1;258 return TokPrec;259}260 261/// Error* - These are little helper functions for error handling.262ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}263PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }264FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }265 266static ExprAST *ParseExpression();267 268/// identifierexpr269/// ::= identifier270/// ::= identifier '(' expression* ')'271static ExprAST *ParseIdentifierExpr() {272 std::string IdName = IdentifierStr;273 274 getNextToken(); // eat identifier.275 276 if (CurTok != '(') // Simple variable ref.277 return new VariableExprAST(IdName);278 279 // Call.280 getNextToken(); // eat (281 std::vector<ExprAST*> Args;282 if (CurTok != ')') {283 while (1) {284 ExprAST *Arg = ParseExpression();285 if (!Arg) return 0;286 Args.push_back(Arg);287 288 if (CurTok == ')') break;289 290 if (CurTok != ',')291 return Error("Expected ')' or ',' in argument list");292 getNextToken();293 }294 }295 296 // Eat the ')'.297 getNextToken();298 299 return new CallExprAST(IdName, Args);300}301 302/// numberexpr ::= number303static ExprAST *ParseNumberExpr() {304 ExprAST *Result = new NumberExprAST(NumVal);305 getNextToken(); // consume the number306 return Result;307}308 309/// parenexpr ::= '(' expression ')'310static ExprAST *ParseParenExpr() {311 getNextToken(); // eat (.312 ExprAST *V = ParseExpression();313 if (!V) return 0;314 315 if (CurTok != ')')316 return Error("expected ')'");317 getNextToken(); // eat ).318 return V;319}320 321/// ifexpr ::= 'if' expression 'then' expression 'else' expression322static ExprAST *ParseIfExpr() {323 getNextToken(); // eat the if.324 325 // condition.326 ExprAST *Cond = ParseExpression();327 if (!Cond) return 0;328 329 if (CurTok != tok_then)330 return Error("expected then");331 getNextToken(); // eat the then332 333 ExprAST *Then = ParseExpression();334 if (Then == 0) return 0;335 336 if (CurTok != tok_else)337 return Error("expected else");338 339 getNextToken();340 341 ExprAST *Else = ParseExpression();342 if (!Else) return 0;343 344 return new IfExprAST(Cond, Then, Else);345}346 347/// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression348static ExprAST *ParseForExpr() {349 getNextToken(); // eat the for.350 351 if (CurTok != tok_identifier)352 return Error("expected identifier after for");353 354 std::string IdName = IdentifierStr;355 getNextToken(); // eat identifier.356 357 if (CurTok != '=')358 return Error("expected '=' after for");359 getNextToken(); // eat '='.360 361 362 ExprAST *Start = ParseExpression();363 if (Start == 0) return 0;364 if (CurTok != ',')365 return Error("expected ',' after for start value");366 getNextToken();367 368 ExprAST *End = ParseExpression();369 if (End == 0) return 0;370 371 // The step value is optional.372 ExprAST *Step = 0;373 if (CurTok == ',') {374 getNextToken();375 Step = ParseExpression();376 if (Step == 0) return 0;377 }378 379 if (CurTok != tok_in)380 return Error("expected 'in' after for");381 getNextToken(); // eat 'in'.382 383 ExprAST *Body = ParseExpression();384 if (Body == 0) return 0;385 386 return new ForExprAST(IdName, Start, End, Step, Body);387}388 389/// varexpr ::= 'var' identifier ('=' expression)?390// (',' identifier ('=' expression)?)* 'in' expression391static ExprAST *ParseVarExpr() {392 getNextToken(); // eat the var.393 394 std::vector<std::pair<std::string, ExprAST*> > VarNames;395 396 // At least one variable name is required.397 if (CurTok != tok_identifier)398 return Error("expected identifier after var");399 400 while (1) {401 std::string Name = IdentifierStr;402 getNextToken(); // eat identifier.403 404 // Read the optional initializer.405 ExprAST *Init = 0;406 if (CurTok == '=') {407 getNextToken(); // eat the '='.408 409 Init = ParseExpression();410 if (Init == 0) return 0;411 }412 413 VarNames.push_back(std::make_pair(Name, Init));414 415 // End of var list, exit loop.416 if (CurTok != ',') break;417 getNextToken(); // eat the ','.418 419 if (CurTok != tok_identifier)420 return Error("expected identifier list after var");421 }422 423 // At this point, we have to have 'in'.424 if (CurTok != tok_in)425 return Error("expected 'in' keyword after 'var'");426 getNextToken(); // eat 'in'.427 428 ExprAST *Body = ParseExpression();429 if (Body == 0) return 0;430 431 return new VarExprAST(VarNames, Body);432}433 434/// primary435/// ::= identifierexpr436/// ::= numberexpr437/// ::= parenexpr438/// ::= ifexpr439/// ::= forexpr440/// ::= varexpr441static ExprAST *ParsePrimary() {442 switch (CurTok) {443 default: return Error("unknown token when expecting an expression");444 case tok_identifier: return ParseIdentifierExpr();445 case tok_number: return ParseNumberExpr();446 case '(': return ParseParenExpr();447 case tok_if: return ParseIfExpr();448 case tok_for: return ParseForExpr();449 case tok_var: return ParseVarExpr();450 }451}452 453/// unary454/// ::= primary455/// ::= '!' unary456static ExprAST *ParseUnary() {457 // If the current token is not an operator, it must be a primary expr.458 if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')459 return ParsePrimary();460 461 // If this is a unary operator, read it.462 int Opc = CurTok;463 getNextToken();464 if (ExprAST *Operand = ParseUnary())465 return new UnaryExprAST(Opc, Operand);466 return 0;467}468 469/// binoprhs470/// ::= ('+' unary)*471static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {472 // If this is a binop, find its precedence.473 while (1) {474 int TokPrec = GetTokPrecedence();475 476 // If this is a binop that binds at least as tightly as the current binop,477 // consume it, otherwise we are done.478 if (TokPrec < ExprPrec)479 return LHS;480 481 // Okay, we know this is a binop.482 int BinOp = CurTok;483 getNextToken(); // eat binop484 485 // Parse the unary expression after the binary operator.486 ExprAST *RHS = ParseUnary();487 if (!RHS) return 0;488 489 // If BinOp binds less tightly with RHS than the operator after RHS, let490 // the pending operator take RHS as its LHS.491 int NextPrec = GetTokPrecedence();492 if (TokPrec < NextPrec) {493 RHS = ParseBinOpRHS(TokPrec+1, RHS);494 if (RHS == 0) return 0;495 }496 497 // Merge LHS/RHS.498 LHS = new BinaryExprAST(BinOp, LHS, RHS);499 }500}501 502/// expression503/// ::= unary binoprhs504///505static ExprAST *ParseExpression() {506 ExprAST *LHS = ParseUnary();507 if (!LHS) return 0;508 509 return ParseBinOpRHS(0, LHS);510}511 512/// prototype513/// ::= id '(' id* ')'514/// ::= binary LETTER number? (id, id)515/// ::= unary LETTER (id)516static PrototypeAST *ParsePrototype() {517 std::string FnName;518 519 unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.520 unsigned BinaryPrecedence = 30;521 522 switch (CurTok) {523 default:524 return ErrorP("Expected function name in prototype");525 case tok_identifier:526 FnName = IdentifierStr;527 Kind = 0;528 getNextToken();529 break;530 case tok_unary:531 getNextToken();532 if (!isascii(CurTok))533 return ErrorP("Expected unary operator");534 FnName = "unary";535 FnName += (char)CurTok;536 Kind = 1;537 getNextToken();538 break;539 case tok_binary:540 getNextToken();541 if (!isascii(CurTok))542 return ErrorP("Expected binary operator");543 FnName = "binary";544 FnName += (char)CurTok;545 Kind = 2;546 getNextToken();547 548 // Read the precedence if present.549 if (CurTok == tok_number) {550 if (NumVal < 1 || NumVal > 100)551 return ErrorP("Invalid precedence: must be 1..100");552 BinaryPrecedence = (unsigned)NumVal;553 getNextToken();554 }555 break;556 }557 558 if (CurTok != '(')559 return ErrorP("Expected '(' in prototype");560 561 std::vector<std::string> ArgNames;562 while (getNextToken() == tok_identifier)563 ArgNames.push_back(IdentifierStr);564 if (CurTok != ')')565 return ErrorP("Expected ')' in prototype");566 567 // success.568 getNextToken(); // eat ')'.569 570 // Verify right number of names for operator.571 if (Kind && ArgNames.size() != Kind)572 return ErrorP("Invalid number of operands for operator");573 574 return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);575}576 577/// definition ::= 'def' prototype expression578static FunctionAST *ParseDefinition() {579 getNextToken(); // eat def.580 PrototypeAST *Proto = ParsePrototype();581 if (Proto == 0) return 0;582 583 if (ExprAST *E = ParseExpression())584 return new FunctionAST(Proto, E);585 return 0;586}587 588/// toplevelexpr ::= expression589static FunctionAST *ParseTopLevelExpr() {590 if (ExprAST *E = ParseExpression()) {591 // Make an anonymous proto.592 PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());593 return new FunctionAST(Proto, E);594 }595 return 0;596}597 598/// external ::= 'extern' prototype599static PrototypeAST *ParseExtern() {600 getNextToken(); // eat extern.601 return ParsePrototype();602}603 604//===----------------------------------------------------------------------===//605// Quick and dirty hack606//===----------------------------------------------------------------------===//607 608// FIXME: Obviously we can do better than this609std::string GenerateUniqueName(const char *root)610{611 static int i = 0;612 char s[16];613 sprintf(s, "%s%d", root, i++);614 std::string S = s;615 return S;616}617 618std::string MakeLegalFunctionName(std::string Name)619{620 std::string NewName;621 if (!Name.length())622 return GenerateUniqueName("anon_func_");623 624 // Start with what we have625 NewName = Name;626 627 // Look for a numeric first character628 if (NewName.find_first_of("0123456789") == 0) {629 NewName.insert(0, 1, 'n');630 }631 632 // Replace illegal characters with their ASCII equivalent633 std::string legal_elements = "_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";634 size_t pos;635 while ((pos = NewName.find_first_not_of(legal_elements)) != std::string::npos) {636 char old_c = NewName.at(pos);637 char new_str[16];638 sprintf(new_str, "%d", (int)old_c);639 NewName = NewName.replace(pos, 1, new_str);640 }641 642 return NewName;643}644 645//===----------------------------------------------------------------------===//646// MCJIT helper class647//===----------------------------------------------------------------------===//648 649class MCJITHelper650{651public:652 MCJITHelper(LLVMContext& C) : Context(C), OpenModule(NULL) {}653 ~MCJITHelper();654 655 Function *getFunction(const std::string FnName);656 Module *getModuleForNewFunction();657 void *getPointerToFunction(Function* F);658 void *getPointerToNamedFunction(const std::string &Name);659 void dump();660 661private:662 typedef std::vector<Module*> ModuleVector;663 typedef std::vector<ExecutionEngine*> EngineVector;664 665 LLVMContext &Context;666 Module *OpenModule;667 ModuleVector Modules;668 EngineVector Engines;669};670 671class HelpingMemoryManager : public SectionMemoryManager672{673 HelpingMemoryManager(const HelpingMemoryManager&) = delete;674 void operator=(const HelpingMemoryManager&) = delete;675 676public:677 HelpingMemoryManager(MCJITHelper *Helper) : MasterHelper(Helper) {}678 virtual ~HelpingMemoryManager() {}679 680 /// This method returns the address of the specified function.681 /// Our implementation will attempt to find functions in other682 /// modules associated with the MCJITHelper to cross link functions683 /// from one generated module to another.684 ///685 /// If \p AbortOnFailure is false and no function with the given name is686 /// found, this function returns a null pointer. Otherwise, it prints a687 /// message to stderr and aborts.688 virtual void *getPointerToNamedFunction(const std::string &Name,689 bool AbortOnFailure = true);690private:691 MCJITHelper *MasterHelper;692};693 694void *HelpingMemoryManager::getPointerToNamedFunction(const std::string &Name,695 bool AbortOnFailure)696{697 // Try the standard symbol resolution first, but ask it not to abort.698 void *pfn = SectionMemoryManager::getPointerToNamedFunction(Name, false);699 if (pfn)700 return pfn;701 702 pfn = MasterHelper->getPointerToNamedFunction(Name);703 if (!pfn && AbortOnFailure)704 report_fatal_error("Program used external function '" + Name +705 "' which could not be resolved!");706 return pfn;707}708 709MCJITHelper::~MCJITHelper()710{711 if (OpenModule)712 delete OpenModule;713 EngineVector::iterator begin = Engines.begin();714 EngineVector::iterator end = Engines.end();715 EngineVector::iterator it;716 for (it = begin; it != end; ++it)717 delete *it;718}719 720Function *MCJITHelper::getFunction(const std::string FnName) {721 ModuleVector::iterator begin = Modules.begin();722 ModuleVector::iterator end = Modules.end();723 ModuleVector::iterator it;724 for (it = begin; it != end; ++it) {725 Function *F = (*it)->getFunction(FnName);726 if (F) {727 if (*it == OpenModule)728 return F;729 730 assert(OpenModule != NULL);731 732 // This function is in a module that has already been JITed.733 // We need to generate a new prototype for external linkage.734 Function *PF = OpenModule->getFunction(FnName);735 if (PF && !PF->empty()) {736 ErrorF("redefinition of function across modules");737 return 0;738 }739 740 // If we don't have a prototype yet, create one.741 if (!PF)742 PF = Function::Create(F->getFunctionType(),743 Function::ExternalLinkage,744 FnName,745 OpenModule);746 return PF;747 }748 }749 return NULL;750}751 752Module *MCJITHelper::getModuleForNewFunction() {753 // If we have a Module that hasn't been JITed, use that.754 if (OpenModule)755 return OpenModule;756 757 // Otherwise create a new Module.758 std::string ModName = GenerateUniqueName("mcjit_module_");759 Module *M = new Module(ModName, Context);760 Modules.push_back(M);761 OpenModule = M;762 return M;763}764 765void *MCJITHelper::getPointerToFunction(Function* F) {766 // See if an existing instance of MCJIT has this function.767 EngineVector::iterator begin = Engines.begin();768 EngineVector::iterator end = Engines.end();769 EngineVector::iterator it;770 for (it = begin; it != end; ++it) {771 void *P = (*it)->getPointerToFunction(F);772 if (P)773 return P;774 }775 776 // If we didn't find the function, see if we can generate it.777 if (OpenModule) {778 std::string ErrStr;779 ExecutionEngine *NewEngine = EngineBuilder(OpenModule)780 .setErrorStr(&ErrStr)781 .setMCJITMemoryManager(new HelpingMemoryManager(this))782 .create();783 if (!NewEngine) {784 fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());785 exit(1);786 }787 788 // Create a function pass manager for this engine789 FunctionPassManager *FPM = new FunctionPassManager(OpenModule);790 791 // Set up the optimizer pipeline. Start with registering info about how the792 // target lays out data structures.793 FPM->add(new DataLayout(*NewEngine->getDataLayout()));794 // Provide basic AliasAnalysis support for GVN.795 FPM->add(createBasicAliasAnalysisPass());796 // Promote allocas to registers.797 FPM->add(createPromoteMemoryToRegisterPass());798 // Do simple "peephole" optimizations and bit-twiddling optzns.799 FPM->add(createInstructionCombiningPass());800 // Reassociate expressions.801 FPM->add(createReassociatePass());802 // Eliminate Common SubExpressions.803 FPM->add(createGVNPass());804 // Simplify the control flow graph (deleting unreachable blocks, etc).805 FPM->add(createCFGSimplificationPass());806 FPM->doInitialization();807 808 // For each function in the module809 Module::iterator it;810 Module::iterator end = OpenModule->end();811 for (it = OpenModule->begin(); it != end; ++it) {812 // Run the FPM on this function813 FPM->run(*it);814 }815 816 // We don't need this anymore817 delete FPM;818 819 OpenModule = NULL;820 Engines.push_back(NewEngine);821 NewEngine->finalizeObject();822 return NewEngine->getPointerToFunction(F);823 }824 return NULL;825}826 827void *MCJITHelper::getPointerToNamedFunction(const std::string &Name)828{829 // Look for the function in each of our execution engines.830 EngineVector::iterator begin = Engines.begin();831 EngineVector::iterator end = Engines.end();832 EngineVector::iterator it;833 for (it = begin; it != end; ++it) {834 if (Function *F = (*it)->FindFunctionNamed(Name.c_str()))835 return (*it)->getPointerToFunction(F);836 }837 838 return NULL;839}840 841void MCJITHelper::dump()842{843 ModuleVector::iterator begin = Modules.begin();844 ModuleVector::iterator end = Modules.end();845 ModuleVector::iterator it;846 for (it = begin; it != end; ++it)847 (*it)->dump();848}849 850//===----------------------------------------------------------------------===//851// Code Generation852//===----------------------------------------------------------------------===//853 854static MCJITHelper *TheHelper;855static LLVMContext TheContext;856static IRBuilder<> Builder(TheContext);857static std::map<std::string, AllocaInst*> NamedValues;858 859Value *ErrorV(const char *Str) { Error(Str); return 0; }860 861/// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of862/// the function. This is used for mutable variables etc.863static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,864 const std::string &VarName) {865 IRBuilder<> TmpB(&TheFunction->getEntryBlock(),866 TheFunction->getEntryBlock().begin());867 return TmpB.CreateAlloca(Type::getDoubleTy(TheContext), 0, VarName.c_str());868}869 870Value *NumberExprAST::Codegen() {871 return ConstantFP::get(TheContext, APFloat(Val));872}873 874Value *VariableExprAST::Codegen() {875 // Look this variable up in the function.876 Value *V = NamedValues[Name];877 char ErrStr[256];878 sprintf(ErrStr, "Unknown variable name %s", Name.c_str());879 if (V == 0) return ErrorV(ErrStr);880 881 // Load the value.882 return Builder.CreateLoad(V, Name.c_str());883}884 885Value *UnaryExprAST::Codegen() {886 Value *OperandV = Operand->Codegen();887 if (OperandV == 0) return 0;888 889 Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("unary")+Opcode));890 if (F == 0)891 return ErrorV("Unknown unary operator");892 893 return Builder.CreateCall(F, OperandV, "unop");894}895 896Value *BinaryExprAST::Codegen() {897 // Special case '=' because we don't want to emit the LHS as an expression.898 if (Op == '=') {899 // Assignment requires the LHS to be an identifier.900 VariableExprAST *LHSE = static_cast<VariableExprAST*>(LHS);901 if (!LHSE)902 return ErrorV("destination of '=' must be a variable");903 // Codegen the RHS.904 Value *Val = RHS->Codegen();905 if (Val == 0) return 0;906 907 // Look up the name.908 Value *Variable = NamedValues[LHSE->getName()];909 if (Variable == 0) return ErrorV("Unknown variable name");910 911 Builder.CreateStore(Val, Variable);912 return Val;913 }914 915 Value *L = LHS->Codegen();916 Value *R = RHS->Codegen();917 if (L == 0 || R == 0) return 0;918 919 switch (Op) {920 case '+': return Builder.CreateFAdd(L, R, "addtmp");921 case '-': return Builder.CreateFSub(L, R, "subtmp");922 case '*': return Builder.CreateFMul(L, R, "multmp");923 case '/': return Builder.CreateFDiv(L, R, "divtmp");924 case '<':925 L = Builder.CreateFCmpULT(L, R, "cmptmp");926 // Convert bool 0/1 to double 0.0 or 1.0927 return Builder.CreateUIToFP(L, Type::getDoubleTy(TheContext), "booltmp");928 default: break;929 }930 931 // If it wasn't a builtin binary operator, it must be a user defined one. Emit932 // a call to it.933 Function *F = TheHelper->getFunction(MakeLegalFunctionName(std::string("binary")+Op));934 assert(F && "binary operator not found!");935 936 Value *Ops[] = { L, R };937 return Builder.CreateCall(F, Ops, "binop");938}939 940Value *CallExprAST::Codegen() {941 // Look up the name in the global module table.942 Function *CalleeF = TheHelper->getFunction(Callee);943 if (CalleeF == 0)944 return ErrorV("Unknown function referenced");945 946 // If argument mismatch error.947 if (CalleeF->arg_size() != Args.size())948 return ErrorV("Incorrect # arguments passed");949 950 std::vector<Value*> ArgsV;951 for (unsigned i = 0, e = Args.size(); i != e; ++i) {952 ArgsV.push_back(Args[i]->Codegen());953 if (ArgsV.back() == 0) return 0;954 }955 956 return Builder.CreateCall(CalleeF, ArgsV, "calltmp");957}958 959Value *IfExprAST::Codegen() {960 Value *CondV = Cond->Codegen();961 if (CondV == 0) return 0;962 963 // Convert condition to a bool by comparing equal to 0.0.964 CondV = Builder.CreateFCmpONE(965 CondV, ConstantFP::get(TheContext, APFloat(0.0)), "ifcond");966 967 Function *TheFunction = Builder.GetInsertBlock()->getParent();968 969 // Create blocks for the then and else cases. Insert the 'then' block at the970 // end of the function.971 BasicBlock *ThenBB = BasicBlock::Create(TheContext, "then", TheFunction);972 BasicBlock *ElseBB = BasicBlock::Create(TheContext, "else");973 BasicBlock *MergeBB = BasicBlock::Create(TheContext, "ifcont");974 975 Builder.CreateCondBr(CondV, ThenBB, ElseBB);976 977 // Emit then value.978 Builder.SetInsertPoint(ThenBB);979 980 Value *ThenV = Then->Codegen();981 if (ThenV == 0) return 0;982 983 Builder.CreateBr(MergeBB);984 // Codegen of 'Then' can change the current block, update ThenBB for the PHI.985 ThenBB = Builder.GetInsertBlock();986 987 // Emit else block.988 TheFunction->insert(TheFunction->end(), ElseBB);989 Builder.SetInsertPoint(ElseBB);990 991 Value *ElseV = Else->Codegen();992 if (ElseV == 0) return 0;993 994 Builder.CreateBr(MergeBB);995 // Codegen of 'Else' can change the current block, update ElseBB for the PHI.996 ElseBB = Builder.GetInsertBlock();997 998 // Emit merge block.999 TheFunction->insert(TheFunction->end(), MergeBB);1000 Builder.SetInsertPoint(MergeBB);1001 PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(TheContext), 2, "iftmp");1002 1003 PN->addIncoming(ThenV, ThenBB);1004 PN->addIncoming(ElseV, ElseBB);1005 return PN;1006}1007 1008Value *ForExprAST::Codegen() {1009 // Output this as:1010 // var = alloca double1011 // ...1012 // start = startexpr1013 // store start -> var1014 // goto loop1015 // loop:1016 // ...1017 // bodyexpr1018 // ...1019 // loopend:1020 // step = stepexpr1021 // endcond = endexpr1022 //1023 // curvar = load var1024 // nextvar = curvar + step1025 // store nextvar -> var1026 // br endcond, loop, endloop1027 // outloop:1028 1029 Function *TheFunction = Builder.GetInsertBlock()->getParent();1030 1031 // Create an alloca for the variable in the entry block.1032 AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);1033 1034 // Emit the start code first, without 'variable' in scope.1035 Value *StartVal = Start->Codegen();1036 if (StartVal == 0) return 0;1037 1038 // Store the value into the alloca.1039 Builder.CreateStore(StartVal, Alloca);1040 1041 // Make the new basic block for the loop header, inserting after current1042 // block.1043 BasicBlock *LoopBB = BasicBlock::Create(TheContext, "loop", TheFunction);1044 1045 // Insert an explicit fall through from the current block to the LoopBB.1046 Builder.CreateBr(LoopBB);1047 1048 // Start insertion in LoopBB.1049 Builder.SetInsertPoint(LoopBB);1050 1051 // Within the loop, the variable is defined equal to the PHI node. If it1052 // shadows an existing variable, we have to restore it, so save it now.1053 AllocaInst *OldVal = NamedValues[VarName];1054 NamedValues[VarName] = Alloca;1055 1056 // Emit the body of the loop. This, like any other expr, can change the1057 // current BB. Note that we ignore the value computed by the body, but don't1058 // allow an error.1059 if (Body->Codegen() == 0)1060 return 0;1061 1062 // Emit the step value.1063 Value *StepVal;1064 if (Step) {1065 StepVal = Step->Codegen();1066 if (StepVal == 0) return 0;1067 } else {1068 // If not specified, use 1.0.1069 StepVal = ConstantFP::get(TheContext, APFloat(1.0));1070 }1071 1072 // Compute the end condition.1073 Value *EndCond = End->Codegen();1074 if (EndCond == 0) return EndCond;1075 1076 // Reload, increment, and restore the alloca. This handles the case where1077 // the body of the loop mutates the variable.1078 Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());1079 Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");1080 Builder.CreateStore(NextVar, Alloca);1081 1082 // Convert condition to a bool by comparing equal to 0.0.1083 EndCond = Builder.CreateFCmpONE(1084 EndCond, ConstantFP::get(TheContext, APFloat(0.0)), "loopcond");1085 1086 // Create the "after loop" block and insert it.1087 BasicBlock *AfterBB =1088 BasicBlock::Create(TheContext, "afterloop", TheFunction);1089 1090 // Insert the conditional branch into the end of LoopEndBB.1091 Builder.CreateCondBr(EndCond, LoopBB, AfterBB);1092 1093 // Any new code will be inserted in AfterBB.1094 Builder.SetInsertPoint(AfterBB);1095 1096 // Restore the unshadowed variable.1097 if (OldVal)1098 NamedValues[VarName] = OldVal;1099 else1100 NamedValues.erase(VarName);1101 1102 1103 // for expr always returns 0.0.1104 return Constant::getNullValue(Type::getDoubleTy(TheContext));1105}1106 1107Value *VarExprAST::Codegen() {1108 std::vector<AllocaInst *> OldBindings;1109 1110 Function *TheFunction = Builder.GetInsertBlock()->getParent();1111 1112 // Register all variables and emit their initializer.1113 for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {1114 const std::string &VarName = VarNames[i].first;1115 ExprAST *Init = VarNames[i].second;1116 1117 // Emit the initializer before adding the variable to scope, this prevents1118 // the initializer from referencing the variable itself, and permits stuff1119 // like this:1120 // var a = 1 in1121 // var a = a in ... # refers to outer 'a'.1122 Value *InitVal;1123 if (Init) {1124 InitVal = Init->Codegen();1125 if (InitVal == 0) return 0;1126 } else { // If not specified, use 0.0.1127 InitVal = ConstantFP::get(TheContext, APFloat(0.0));1128 }1129 1130 AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);1131 Builder.CreateStore(InitVal, Alloca);1132 1133 // Remember the old variable binding so that we can restore the binding when1134 // we unrecurse.1135 OldBindings.push_back(NamedValues[VarName]);1136 1137 // Remember this binding.1138 NamedValues[VarName] = Alloca;1139 }1140 1141 // Codegen the body, now that all vars are in scope.1142 Value *BodyVal = Body->Codegen();1143 if (BodyVal == 0) return 0;1144 1145 // Pop all our variables from scope.1146 for (unsigned i = 0, e = VarNames.size(); i != e; ++i)1147 NamedValues[VarNames[i].first] = OldBindings[i];1148 1149 // Return the body computation.1150 return BodyVal;1151}1152 1153Function *PrototypeAST::Codegen() {1154 // Make the function type: double(double,double) etc.1155 std::vector<Type *> Doubles(Args.size(), Type::getDoubleTy(TheContext));1156 FunctionType *FT =1157 FunctionType::get(Type::getDoubleTy(TheContext), Doubles, false);1158 1159 std::string FnName = MakeLegalFunctionName(Name);1160 1161 Module* M = TheHelper->getModuleForNewFunction();1162 1163 Function *F = Function::Create(FT, Function::ExternalLinkage, FnName, M);1164 1165 // If F conflicted, there was already something named 'FnName'. If it has a1166 // body, don't allow redefinition or reextern.1167 if (F->getName() != FnName) {1168 // Delete the one we just made and get the existing one.1169 F->eraseFromParent();1170 F = M->getFunction(Name);1171 1172 // If F already has a body, reject this.1173 if (!F->empty()) {1174 ErrorF("redefinition of function");1175 return 0;1176 }1177 1178 // If F took a different number of args, reject.1179 if (F->arg_size() != Args.size()) {1180 ErrorF("redefinition of function with different # args");1181 return 0;1182 }1183 }1184 1185 // Set names for all arguments.1186 unsigned Idx = 0;1187 for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();1188 ++AI, ++Idx)1189 AI->setName(Args[Idx]);1190 1191 return F;1192}1193 1194/// CreateArgumentAllocas - Create an alloca for each argument and register the1195/// argument in the symbol table so that references to it will succeed.1196void PrototypeAST::CreateArgumentAllocas(Function *F) {1197 Function::arg_iterator AI = F->arg_begin();1198 for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {1199 // Create an alloca for this variable.1200 AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);1201 1202 // Store the initial value into the alloca.1203 Builder.CreateStore(AI, Alloca);1204 1205 // Add arguments to variable symbol table.1206 NamedValues[Args[Idx]] = Alloca;1207 }1208}1209 1210Function *FunctionAST::Codegen() {1211 NamedValues.clear();1212 1213 Function *TheFunction = Proto->Codegen();1214 if (TheFunction == 0)1215 return 0;1216 1217 // If this is an operator, install it.1218 if (Proto->isBinaryOp())1219 BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();1220 1221 // Create a new basic block to start insertion into.1222 BasicBlock *BB = BasicBlock::Create(TheContext, "entry", TheFunction);1223 Builder.SetInsertPoint(BB);1224 1225 // Add all arguments to the symbol table and create their allocas.1226 Proto->CreateArgumentAllocas(TheFunction);1227 1228 if (Value *RetVal = Body->Codegen()) {1229 // Finish off the function.1230 Builder.CreateRet(RetVal);1231 1232 // Validate the generated code, checking for consistency.1233 verifyFunction(*TheFunction);1234 1235 return TheFunction;1236 }1237 1238 // Error reading body, remove function.1239 TheFunction->eraseFromParent();1240 1241 if (Proto->isBinaryOp())1242 BinopPrecedence.erase(Proto->getOperatorName());1243 return 0;1244}1245 1246//===----------------------------------------------------------------------===//1247// Top-Level parsing and JIT Driver1248//===----------------------------------------------------------------------===//1249 1250static void HandleDefinition() {1251 if (FunctionAST *F = ParseDefinition()) {1252 if (Function *LF = F->Codegen()) {1253#ifndef MINIMAL_STDERR_OUTPUT1254 fprintf(stderr, "Read function definition:");1255 LF->print(errs());1256 fprintf(stderr, "\n");1257#endif1258 }1259 } else {1260 // Skip token for error recovery.1261 getNextToken();1262 }1263}1264 1265static void HandleExtern() {1266 if (PrototypeAST *P = ParseExtern()) {1267 if (Function *F = P->Codegen()) {1268#ifndef MINIMAL_STDERR_OUTPUT1269 fprintf(stderr, "Read extern: ");1270 F->print(errs());1271 fprintf(stderr, "\n");1272#endif1273 }1274 } else {1275 // Skip token for error recovery.1276 getNextToken();1277 }1278}1279 1280static void HandleTopLevelExpression() {1281 // Evaluate a top-level expression into an anonymous function.1282 if (FunctionAST *F = ParseTopLevelExpr()) {1283 if (Function *LF = F->Codegen()) {1284 // JIT the function, returning a function pointer.1285 void *FPtr = TheHelper->getPointerToFunction(LF);1286 1287 // Cast it to the right type (takes no arguments, returns a double) so we1288 // can call it as a native function.1289 double (*FP)() = (double (*)())(intptr_t)FPtr;1290#ifdef MINIMAL_STDERR_OUTPUT1291 FP();1292#else1293 fprintf(stderr, "Evaluated to %f\n", FP());1294#endif1295 }1296 } else {1297 // Skip token for error recovery.1298 getNextToken();1299 }1300}1301 1302/// top ::= definition | external | expression | ';'1303static void MainLoop() {1304 while (1) {1305#ifndef MINIMAL_STDERR_OUTPUT1306 fprintf(stderr, "ready> ");1307#endif1308 switch (CurTok) {1309 case tok_eof: return;1310 case ';': getNextToken(); break; // ignore top-level semicolons.1311 case tok_def: HandleDefinition(); break;1312 case tok_extern: HandleExtern(); break;1313 default: HandleTopLevelExpression(); break;1314 }1315 }1316}1317 1318//===----------------------------------------------------------------------===//1319// "Library" functions that can be "extern'd" from user code.1320//===----------------------------------------------------------------------===//1321 1322/// putchard - putchar that takes a double and returns 0.1323extern "C"1324double putchard(double X) {1325 putchar((char)X);1326 return 0;1327}1328 1329/// printd - printf that takes a double prints it as "%f\n", returning 0.1330extern "C"1331double printd(double X) {1332 printf("%f", X);1333 return 0;1334}1335 1336extern "C"1337double printlf() {1338 printf("\n");1339 return 0;1340}1341 1342//===----------------------------------------------------------------------===//1343// Main driver code.1344//===----------------------------------------------------------------------===//1345 1346int main() {1347 InitializeNativeTarget();1348 InitializeNativeTargetAsmPrinter();1349 InitializeNativeTargetAsmParser();1350 LLVMContext &Context = TheContext;1351 1352 // Install standard binary operators.1353 // 1 is lowest precedence.1354 BinopPrecedence['='] = 2;1355 BinopPrecedence['<'] = 10;1356 BinopPrecedence['+'] = 20;1357 BinopPrecedence['-'] = 20;1358 BinopPrecedence['/'] = 40;1359 BinopPrecedence['*'] = 40; // highest.1360 1361 // Prime the first token.1362#ifndef MINIMAL_STDERR_OUTPUT1363 fprintf(stderr, "ready> ");1364#endif1365 getNextToken();1366 1367 // Make the helper, which holds all the code.1368 TheHelper = new MCJITHelper(Context);1369 1370 // Run the main "interpreter loop" now.1371 MainLoop();1372 1373#ifndef MINIMAL_STDERR_OUTPUT1374 // Print out all of the generated code.1375 TheHelper->print(errs());1376#endif1377 1378 return 0;1379}1380