diff options
Diffstat (limited to 'docs/tutorial/LangImpl5.rst')
| -rw-r--r-- | docs/tutorial/LangImpl5.rst | 862 |
1 files changed, 2 insertions, 860 deletions
diff --git a/docs/tutorial/LangImpl5.rst b/docs/tutorial/LangImpl5.rst index 80d5f37bc4..ed5b652f63 100644 --- a/docs/tutorial/LangImpl5.rst +++ b/docs/tutorial/LangImpl5.rst @@ -742,866 +742,8 @@ the if/then/else and for expressions.. To build this example, use: Here is the code: -.. code-block:: c++ - - #include "llvm/DerivedTypes.h" - #include "llvm/ExecutionEngine/ExecutionEngine.h" - #include "llvm/ExecutionEngine/JIT.h" - #include "llvm/IRBuilder.h" - #include "llvm/LLVMContext.h" - #include "llvm/Module.h" - #include "llvm/PassManager.h" - #include "llvm/Analysis/Verifier.h" - #include "llvm/Analysis/Passes.h" - #include "llvm/DataLayout.h" - #include "llvm/Transforms/Scalar.h" - #include "llvm/Support/TargetSelect.h" - #include <cstdio> - #include <string> - #include <map> - #include <vector> - using namespace llvm; - - //===----------------------------------------------------------------------===// - // Lexer - //===----------------------------------------------------------------------===// - - // The lexer returns tokens [0-255] if it is an unknown character, otherwise one - // of these for known things. - enum Token { - tok_eof = -1, - - // commands - tok_def = -2, tok_extern = -3, - - // primary - tok_identifier = -4, tok_number = -5, - - // control - tok_if = -6, tok_then = -7, tok_else = -8, - tok_for = -9, tok_in = -10 - }; - - static std::string IdentifierStr; // Filled in if tok_identifier - static double NumVal; // Filled in if tok_number - - /// gettok - Return the next token from standard input. - static int gettok() { - static int LastChar = ' '; - - // Skip any whitespace. - while (isspace(LastChar)) - LastChar = getchar(); - - if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]* - IdentifierStr = LastChar; - while (isalnum((LastChar = getchar()))) - IdentifierStr += LastChar; - - if (IdentifierStr == "def") return tok_def; - if (IdentifierStr == "extern") return tok_extern; - if (IdentifierStr == "if") return tok_if; - if (IdentifierStr == "then") return tok_then; - if (IdentifierStr == "else") return tok_else; - if (IdentifierStr == "for") return tok_for; - if (IdentifierStr == "in") return tok_in; - return tok_identifier; - } - - if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+ - std::string NumStr; - do { - NumStr += LastChar; - LastChar = getchar(); - } while (isdigit(LastChar) || LastChar == '.'); - - NumVal = strtod(NumStr.c_str(), 0); - return tok_number; - } - - if (LastChar == '#') { - // Comment until end of line. - do LastChar = getchar(); - while (LastChar != EOF && LastChar != '\n' && LastChar != '\r'); - - if (LastChar != EOF) - return gettok(); - } - - // Check for end of file. Don't eat the EOF. - if (LastChar == EOF) - return tok_eof; - - // Otherwise, just return the character as its ascii value. - int ThisChar = LastChar; - LastChar = getchar(); - return ThisChar; - } - - //===----------------------------------------------------------------------===// - // Abstract Syntax Tree (aka Parse Tree) - //===----------------------------------------------------------------------===// - - /// ExprAST - Base class for all expression nodes. - class ExprAST { - public: - virtual ~ExprAST() {} - virtual Value *Codegen() = 0; - }; - - /// NumberExprAST - Expression class for numeric literals like "1.0". - class NumberExprAST : public ExprAST { - double Val; - public: - NumberExprAST(double val) : Val(val) {} - virtual Value *Codegen(); - }; - - /// VariableExprAST - Expression class for referencing a variable, like "a". - class VariableExprAST : public ExprAST { - std::string Name; - public: - VariableExprAST(const std::string &name) : Name(name) {} - virtual Value *Codegen(); - }; - - /// BinaryExprAST - Expression class for a binary operator. - class BinaryExprAST : public ExprAST { - char Op; - ExprAST *LHS, *RHS; - public: - BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) - : Op(op), LHS(lhs), RHS(rhs) {} - virtual Value *Codegen(); - }; - - /// CallExprAST - Expression class for function calls. - class CallExprAST : public ExprAST { - std::string Callee; - std::vector<ExprAST*> Args; - public: - CallExprAST(const std::string &callee, std::vector<ExprAST*> &args) - : Callee(callee), Args(args) {} - virtual Value *Codegen(); - }; - - /// IfExprAST - Expression class for if/then/else. - class IfExprAST : public ExprAST { - ExprAST *Cond, *Then, *Else; - public: - IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else) - : Cond(cond), Then(then), Else(_else) {} - virtual Value *Codegen(); - }; - - /// ForExprAST - Expression class for for/in. - class ForExprAST : public ExprAST { - std::string VarName; - ExprAST *Start, *End, *Step, *Body; - public: - ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end, - ExprAST *step, ExprAST *body) - : VarName(varname), Start(start), End(end), Step(step), Body(body) {} - virtual Value *Codegen(); - }; - - /// PrototypeAST - This class represents the "prototype" for a function, - /// which captures its name, and its argument names (thus implicitly the number - /// of arguments the function takes). - class PrototypeAST { - std::string Name; - std::vector<std::string> Args; - public: - PrototypeAST(const std::string &name, const std::vector<std::string> &args) - : Name(name), Args(args) {} - - Function *Codegen(); - }; - - /// FunctionAST - This class represents a function definition itself. - class FunctionAST { - PrototypeAST *Proto; - ExprAST *Body; - public: - FunctionAST(PrototypeAST *proto, ExprAST *body) - : Proto(proto), Body(body) {} - - Function *Codegen(); - }; - - //===----------------------------------------------------------------------===// - // Parser - //===----------------------------------------------------------------------===// - - /// CurTok/getNextToken - Provide a simple token buffer. CurTok is the current - /// token the parser is looking at. getNextToken reads another token from the - /// lexer and updates CurTok with its results. - static int CurTok; - static int getNextToken() { - return CurTok = gettok(); - } - - /// BinopPrecedence - This holds the precedence for each binary operator that is - /// defined. - static std::map<char, int> BinopPrecedence; - - /// GetTokPrecedence - Get the precedence of the pending binary operator token. - static int GetTokPrecedence() { - if (!isascii(CurTok)) - return -1; - - // Make sure it's a declared binop. - int TokPrec = BinopPrecedence[CurTok]; - if (TokPrec <= 0) return -1; - return TokPrec; - } - - /// Error* - These are little helper functions for error handling. - ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;} - PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; } - FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; } - - static ExprAST *ParseExpression(); - - /// identifierexpr - /// ::= identifier - /// ::= identifier '(' expression* ')' - static ExprAST *ParseIdentifierExpr() { - std::string IdName = IdentifierStr; - - getNextToken(); // eat identifier. - - if (CurTok != '(') // Simple variable ref. - return new VariableExprAST(IdName); - - // Call. - getNextToken(); // eat ( - std::vector<ExprAST*> Args; - if (CurTok != ')') { - while (1) { - ExprAST *Arg = ParseExpression(); - if (!Arg) return 0; - Args.push_back(Arg); - - if (CurTok == ')') break; - - if (CurTok != ',') - return Error("Expected ')' or ',' in argument list"); - getNextToken(); - } - } - - // Eat the ')'. - getNextToken(); - - return new CallExprAST(IdName, Args); - } - - /// numberexpr ::= number - static ExprAST *ParseNumberExpr() { - ExprAST *Result = new NumberExprAST(NumVal); - getNextToken(); // consume the number - return Result; - } - - /// parenexpr ::= '(' expression ')' - static ExprAST *ParseParenExpr() { - getNextToken(); // eat (. - ExprAST *V = ParseExpression(); - if (!V) return 0; - - if (CurTok != ')') - return Error("expected ')'"); - getNextToken(); // eat ). - return V; - } - - /// ifexpr ::= 'if' expression 'then' expression 'else' expression - static ExprAST *ParseIfExpr() { - getNextToken(); // eat the if. - - // condition. - ExprAST *Cond = ParseExpression(); - if (!Cond) return 0; - - if (CurTok != tok_then) - return Error("expected then"); - getNextToken(); // eat the then - - ExprAST *Then = ParseExpression(); - if (Then == 0) return 0; - - if (CurTok != tok_else) - return Error("expected else"); - - getNextToken(); - - ExprAST *Else = ParseExpression(); - if (!Else) return 0; - - return new IfExprAST(Cond, Then, Else); - } - - /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression - static ExprAST *ParseForExpr() { - getNextToken(); // eat the for. - - if (CurTok != tok_identifier) - return Error("expected identifier after for"); - - std::string IdName = IdentifierStr; - getNextToken(); // eat identifier. - - if (CurTok != '=') - return Error("expected '=' after for"); - getNextToken(); // eat '='. - - - ExprAST *Start = ParseExpression(); - if (Start == 0) return 0; - if (CurTok != ',') - return Error("expected ',' after for start value"); - getNextToken(); - - ExprAST *End = ParseExpression(); - if (End == 0) return 0; - - // The step value is optional. - ExprAST *Step = 0; - if (CurTok == ',') { - getNextToken(); - Step = ParseExpression(); - if (Step == 0) return 0; - } - - if (CurTok != tok_in) - return Error("expected 'in' after for"); - getNextToken(); // eat 'in'. - - ExprAST *Body = ParseExpression(); - if (Body == 0) return 0; - - return new ForExprAST(IdName, Start, End, Step, Body); - } - - /// primary - /// ::= identifierexpr - /// ::= numberexpr - /// ::= parenexpr - /// ::= ifexpr - /// ::= forexpr - static ExprAST *ParsePrimary() { - switch (CurTok) { - default: return Error("unknown token when expecting an expression"); - case tok_identifier: return ParseIdentifierExpr(); - case tok_number: return ParseNumberExpr(); - case '(': return ParseParenExpr(); - case tok_if: return ParseIfExpr(); - case tok_for: return ParseForExpr(); - } - } - - /// binoprhs - /// ::= ('+' primary)* - static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) { - // If this is a binop, find its precedence. - while (1) { - int TokPrec = GetTokPrecedence(); - - // If this is a binop that binds at least as tightly as the current binop, - // consume it, otherwise we are done. - if (TokPrec < ExprPrec) - return LHS; - - // Okay, we know this is a binop. - int BinOp = CurTok; - getNextToken(); // eat binop - - // Parse the primary expression after the binary operator. - ExprAST *RHS = ParsePrimary(); - if (!RHS) return 0; - - // If BinOp binds less tightly with RHS than the operator after RHS, let - // the pending operator take RHS as its LHS. - int NextPrec = GetTokPrecedence(); - if (TokPrec < NextPrec) { - RHS = ParseBinOpRHS(TokPrec+1, RHS); - if (RHS == 0) return 0; - } - - // Merge LHS/RHS. - LHS = new BinaryExprAST(BinOp, LHS, RHS); - } - } - - /// expression - /// ::= primary binoprhs - /// - static ExprAST *ParseExpression() { - ExprAST *LHS = ParsePrimary(); - if (!LHS) return 0; - - return ParseBinOpRHS(0, LHS); - } - - /// prototype - /// ::= id '(' id* ')' - static PrototypeAST *ParsePrototype() { - if (CurTok != tok_identifier) - return ErrorP("Expected function name in prototype"); - - std::string FnName = IdentifierStr; - getNextToken(); - - if (CurTok != '(') - return ErrorP("Expected '(' in prototype"); - - std::vector<std::string> ArgNames; - while (getNextToken() == tok_identifier) - ArgNames.push_back(IdentifierStr); - if (CurTok != ')') - return ErrorP("Expected ')' in prototype"); - - // success. - getNextToken(); // eat ')'. - - return new PrototypeAST(FnName, ArgNames); - } - - /// definition ::= 'def' prototype expression - static FunctionAST *ParseDefinition() { - getNextToken(); // eat def. - PrototypeAST *Proto = ParsePrototype(); - if (Proto == 0) return 0; - - if (ExprAST *E = ParseExpression()) - return new FunctionAST(Proto, E); - return 0; - } - - /// toplevelexpr ::= expression - static FunctionAST *ParseTopLevelExpr() { - if (ExprAST *E = ParseExpression()) { - // Make an anonymous proto. - PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>()); - return new FunctionAST(Proto, E); - } - return 0; - } - - /// external ::= 'extern' prototype - static PrototypeAST *ParseExtern() { - getNextToken(); // eat extern. - return ParsePrototype(); - } - - //===----------------------------------------------------------------------===// - // Code Generation - //===----------------------------------------------------------------------===// - - static Module *TheModule; - static IRBuilder<> Builder(getGlobalContext()); - static std::map<std::string, Value*> NamedValues; - static FunctionPassManager *TheFPM; - - Value *ErrorV(const char *Str) { Error(Str); return 0; } - - Value *NumberExprAST::Codegen() { - return ConstantFP::get(getGlobalContext(), APFloat(Val)); - } - - Value *VariableExprAST::Codegen() { - // Look this variable up in the function. - Value *V = NamedValues[Name]; - return V ? V : ErrorV("Unknown variable name"); - } - - Value *BinaryExprAST::Codegen() { - Value *L = LHS->Codegen(); - Value *R = RHS->Codegen(); - if (L == 0 || R == 0) return 0; - - switch (Op) { - case '+': return Builder.CreateFAdd(L, R, "addtmp"); - case '-': return Builder.CreateFSub(L, R, "subtmp"); - case '*': return Builder.CreateFMul(L, R, "multmp"); - case '<': - L = Builder.CreateFCmpULT(L, R, "cmptmp"); - // Convert bool 0/1 to double 0.0 or 1.0 - return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()), - "booltmp"); - default: return ErrorV("invalid binary operator"); - } - } - - Value *CallExprAST::Codegen() { - // Look up the name in the global module table. - Function *CalleeF = TheModule->getFunction(Callee); - if (CalleeF == 0) - return ErrorV("Unknown function referenced"); - - // If argument mismatch error. - if (CalleeF->arg_size() != Args.size()) - return ErrorV("Incorrect # arguments passed"); - - std::vector<Value*> ArgsV; - for (unsigned i = 0, e = Args.size(); i != e; ++i) { - ArgsV.push_back(Args[i]->Codegen()); - if (ArgsV.back() == 0) return 0; - } - - return Builder.CreateCall(CalleeF, ArgsV, "calltmp"); - } - - Value *IfExprAST::Codegen() { - Value *CondV = Cond->Codegen(); - if (CondV == 0) return 0; - - // Convert condition to a bool by comparing equal to 0.0. - CondV = Builder.CreateFCmpONE(CondV, - ConstantFP::get(getGlobalContext(), APFloat(0.0)), - "ifcond"); - - Function *TheFunction = Builder.GetInsertBlock()->getParent(); - - // Create blocks for the then and else cases. Insert the 'then' block at the - // end of the function. - BasicBlock *ThenBB = BasicBlock::Create(getGlobalContext(), "then", TheFunction); - BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else"); - BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont"); - - Builder.CreateCondBr(CondV, ThenBB, ElseBB); - - // Emit then value. - Builder.SetInsertPoint(ThenBB); - - Value *ThenV = Then->Codegen(); - if (ThenV == 0) return 0; - - Builder.CreateBr(MergeBB); - // Codegen of 'Then' can change the current block, update ThenBB for the PHI. - ThenBB = Builder.GetInsertBlock(); - - // Emit else block. - TheFunction->getBasicBlockList().push_back(ElseBB); - Builder.SetInsertPoint(ElseBB); - - Value *ElseV = Else->Codegen(); - if (ElseV == 0) return 0; - - Builder.CreateBr(MergeBB); - // Codegen of 'Else' can change the current block, update ElseBB for the PHI. - ElseBB = Builder.GetInsertBlock(); - - // Emit merge block. - TheFunction->getBasicBlockList().push_back(MergeBB); - Builder.SetInsertPoint(MergeBB); - PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, - "iftmp"); - - PN->addIncoming(ThenV, ThenBB); - PN->addIncoming(ElseV, ElseBB); - return PN; - } - - Value *ForExprAST::Codegen() { - // Output this as: - // ... - // start = startexpr - // goto loop - // loop: - // variable = phi [start, loopheader], [nextvariable, loopend] - // ... - // bodyexpr - // ... - // loopend: - // step = stepexpr - // nextvariable = variable + step - // endcond = endexpr - // br endcond, loop, endloop - // outloop: - - // Emit the start code first, without 'variable' in scope. - Value *StartVal = Start->Codegen(); - if (StartVal == 0) return 0; - - // Make the new basic block for the loop header, inserting after current - // block. - Function *TheFunction = Builder.GetInsertBlock()->getParent(); - BasicBlock *PreheaderBB = Builder.GetInsertBlock(); - BasicBlock *LoopBB = BasicBlock::Create(getGlobalContext(), "loop", TheFunction); - - // Insert an explicit fall through from the current block to the LoopBB. - Builder.CreateBr(LoopBB); - - // Start insertion in LoopBB. - Builder.SetInsertPoint(LoopBB); - - // Start the PHI node with an entry for Start. - PHINode *Variable = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, VarName.c_str()); - Variable->addIncoming(StartVal, PreheaderBB); - - // Within the loop, the variable is defined equal to the PHI node. If it - // shadows an existing variable, we have to restore it, so save it now. - Value *OldVal = NamedValues[VarName]; - NamedValues[VarName] = Variable; - - // Emit the body of the loop. This, like any other expr, can change the - // current BB. Note that we ignore the value computed by the body, but don't - // allow an error. - if (Body->Codegen() == 0) - return 0; - - // Emit the step value. - Value *StepVal; - if (Step) { - StepVal = Step->Codegen(); - if (StepVal == 0) return 0; - } else { - // If not specified, use 1.0. - StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0)); - } - - Value *NextVar = Builder.CreateFAdd(Variable, StepVal, "nextvar"); - - // Compute the end condition. - Value *EndCond = End->Codegen(); - if (EndCond == 0) return EndCond; - - // Convert condition to a bool by comparing equal to 0.0. - EndCond = Builder.CreateFCmpONE(EndCond, - ConstantFP::get(getGlobalContext(), APFloat(0.0)), - "loopcond"); - - // Create the "after loop" block and insert it. - BasicBlock *LoopEndBB = Builder.GetInsertBlock(); - BasicBlock *AfterBB = BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction); - - // Insert the conditional branch into the end of LoopEndBB. - Builder.CreateCondBr(EndCond, LoopBB, AfterBB); - - // Any new code will be inserted in AfterBB. - Builder.SetInsertPoint(AfterBB); - - // Add a new entry to the PHI node for the backedge. - Variable->addIncoming(NextVar, LoopEndBB); - - // Restore the unshadowed variable. - if (OldVal) - NamedValues[VarName] = OldVal; - else - NamedValues.erase(VarName); - - - // for expr always returns 0.0. - return Constant::getNullValue(Type::getDoubleTy(getGlobalContext())); - } - - Function *PrototypeAST::Codegen() { - // Make the function type: double(double,double) etc. - std::vector<Type*> Doubles(Args.size(), - Type::getDoubleTy(getGlobalContext())); - FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()), - Doubles, false); - - Function *F = Function::Create(FT, Function::ExternalLinkage, Name, TheModule); - - // If F conflicted, there was already something named 'Name'. If it has a - // body, don't allow redefinition or reextern. - if (F->getName() != Name) { - // Delete the one we just made and get the existing one. - F->eraseFromParent(); - F = TheModule->getFunction(Name); - - // If F already has a body, reject this. - if (!F->empty()) { - ErrorF("redefinition of function"); - return 0; - } - - // If F took a different number of args, reject. - if (F->arg_size() != Args.size()) { - ErrorF("redefinition of function with different # args"); - return 0; - } - } - - // Set names for all arguments. - unsigned Idx = 0; - for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size(); - ++AI, ++Idx) { - AI->setName(Args[Idx]); - - // Add arguments to variable symbol table. - NamedValues[Args[Idx]] = AI; - } - - return F; - } - - Function *FunctionAST::Codegen() { - NamedValues.clear(); - - Function *TheFunction = Proto->Codegen(); - if (TheFunction == 0) - return 0; - - // Create a new basic block to start insertion into. - BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction); - Builder.SetInsertPoint(BB); - - if (Value *RetVal = Body->Codegen()) { - // Finish off the function. - Builder.CreateRet(RetVal); - - // Validate the generated code, checking for consistency. - verifyFunction(*TheFunction); - - // Optimize the function. - TheFPM->run(*TheFunction); - - return TheFunction; - } - - // Error reading body, remove function. - TheFunction->eraseFromParent(); - return 0; - } - - //===----------------------------------------------------------------------===// - // Top-Level parsing and JIT Driver - //===----------------------------------------------------------------------===// - - static ExecutionEngine *TheExecutionEngine; - - static void HandleDefinition() { - if (FunctionAST *F = ParseDefinition()) { - if (Function *LF = F->Codegen()) { - fprintf(stderr, "Read function definition:"); - LF->dump(); - } - } else { - // Skip token for error recovery. - getNextToken(); - } - } - - static void HandleExtern() { - if (PrototypeAST *P = ParseExtern()) { - if (Function *F = P->Codegen()) { - fprintf(stderr, "Read extern: "); - F->dump(); - } - } else { - // Skip token for error recovery. - getNextToken(); - } - } - - static void HandleTopLevelExpression() { - // Evaluate a top-level expression into an anonymous function. - if (FunctionAST *F = ParseTopLevelExpr()) { - if (Function *LF = F->Codegen()) { - // JIT the function, returning a function pointer. - void *FPtr = TheExecutionEngine->getPointerToFunction(LF); - - // Cast it to the right type (takes no arguments, returns a double) so we - // can call it as a native function. - double (*FP)() = (double (*)())(intptr_t)FPtr; - fprintf(stderr, "Evaluated to %f\n", FP()); - } - } else { - // Skip token for error recovery. - getNextToken(); - } - } - - /// top ::= definition | external | expression | ';' - static void MainLoop() { - while (1) { - fprintf(stderr, "ready> "); - switch (CurTok) { - case tok_eof: return; - case ';': getNextToken(); break; // ignore top-level semicolons. - case tok_def: HandleDefinition(); break; - case tok_extern: HandleExtern(); break; - default: HandleTopLevelExpression(); break; - } - } - } - - //===----------------------------------------------------------------------===// - // "Library" functions that can be "extern'd" from user code. - //===----------------------------------------------------------------------===// - - /// putchard - putchar that takes a double and returns 0. - extern "C" - double putchard(double X) { - putchar((char)X); - return 0; - } - - //===----------------------------------------------------------------------===// - // Main driver code. - //===----------------------------------------------------------------------===// - - int main() { - InitializeNativeTarget(); - LLVMContext &Context = getGlobalContext(); - - // Install standard binary operators. - // 1 is lowest precedence. - BinopPrecedence['<'] = 10; - BinopPrecedence['+'] = 20; - BinopPrecedence['-'] = 20; - BinopPrecedence['*'] = 40; // highest. - - // Prime the first token. - fprintf(stderr, "ready> "); - getNextToken(); - - // Make the module, which holds all the code. - TheModule = new Module("my cool jit", Context); - - // Create the JIT. This takes ownership of the module. - std::string ErrStr; - TheExecutionEngine = EngineBuilder(TheModule).setErrorStr(&ErrStr).create(); - if (!TheExecutionEngine) { - fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str()); - exit(1); - } - - FunctionPassManager OurFPM(TheModule); - - // Set up the optimizer pipeline. Start with registering info about how the - // target lays out data structures. - OurFPM.add(new DataLayout(*TheExecutionEngine->getDataLayout())); - // Provide basic AliasAnalysis support for GVN. - OurFPM.add(createBasicAliasAnalysisPass()); - // Do simple "peephole" optimizations and bit-twiddling optzns. - OurFPM.add(createInstructionCombiningPass()); - // Reassociate expressions. - OurFPM.add(createReassociatePass()); - // Eliminate Common SubExpressions. - OurFPM.add(createGVNPass()); - // Simplify the control flow graph (deleting unreachable blocks, etc). - OurFPM.add(createCFGSimplificationPass()); - - OurFPM.doInitialization(); - - // Set the global so the code gen can use this. - TheFPM = &OurFPM; - - // Run the main "interpreter loop" now. - MainLoop(); - - TheFPM = 0; - - // Print out all of the generated code. - TheModule->dump(); - - return 0; - } +.. literalinclude:: ../../examples/Kaleidoscope/Chapter5/toy.cpp + :language: c++ `Next: Extending the language: user-defined operators <LangImpl6.html>`_ |