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authorLogan Chien <tzuhsiang.chien@gmail.com>2013-06-08 09:03:03 +0000
committerLogan Chien <tzuhsiang.chien@gmail.com>2013-06-08 09:03:03 +0000
commit2dce4f27ef3725f1d1bd31cc07251b2925997262 (patch)
treefd74ca750b6f31c1ff2f55c18347e40869e795c7 /docs/tutorial/LangImpl5.rst
parent9792b646c68d0dcee4049662091f1496b4c85ce7 (diff)
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Update code listings in LLVM tutorial.
Several LLVM headers are moved. The code listings in LLVM tutorial are not updated yet. This CL removes the code replica in the .rst, and replace them with a literalinclude directive, so that sphinx can include the latest code automatically. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183607 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs/tutorial/LangImpl5.rst')
-rw-r--r--docs/tutorial/LangImpl5.rst862
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>`_