[llvm] r183607 - Update code listings in LLVM tutorial.
Logan Chien
tzuhsiang.chien at gmail.com
Sat Jun 8 02:03:04 PDT 2013
Author: logan
Date: Sat Jun 8 04:03:03 2013
New Revision: 183607
URL: http://llvm.org/viewvc/llvm-project?rev=183607&view=rev
Log:
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.
Modified:
llvm/trunk/docs/tutorial/LangImpl2.rst
llvm/trunk/docs/tutorial/LangImpl3.rst
llvm/trunk/docs/tutorial/LangImpl4.rst
llvm/trunk/docs/tutorial/LangImpl5.rst
llvm/trunk/docs/tutorial/LangImpl6.rst
llvm/trunk/docs/tutorial/LangImpl7.rst
Modified: llvm/trunk/docs/tutorial/LangImpl2.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/tutorial/LangImpl2.rst?rev=183607&r1=183606&r2=183607&view=diff
==============================================================================
--- llvm/trunk/docs/tutorial/LangImpl2.rst (original)
+++ llvm/trunk/docs/tutorial/LangImpl2.rst Sat Jun 8 04:03:03 2013
@@ -691,406 +691,8 @@ libraries, of course.) To build this, ju
Here is the code:
-.. code-block:: c++
-
- #include <cstdio>
- #include <cstdlib>
- #include <string>
- #include <map>
- #include <vector>
-
- //===----------------------------------------------------------------------===//
- // 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
- };
-
- 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;
- 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() {}
- };
-
- /// NumberExprAST - Expression class for numeric literals like "1.0".
- class NumberExprAST : public ExprAST {
- double Val;
- public:
- NumberExprAST(double val) : Val(val) {}
- };
-
- /// VariableExprAST - Expression class for referencing a variable, like "a".
- class VariableExprAST : public ExprAST {
- std::string Name;
- public:
- VariableExprAST(const std::string &name) : Name(name) {}
- };
-
- /// 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) {}
- };
-
- /// 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) {}
- };
-
- /// 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) {}
-
- };
-
- /// FunctionAST - This class represents a function definition itself.
- class FunctionAST {
- PrototypeAST *Proto;
- ExprAST *Body;
- public:
- FunctionAST(PrototypeAST *proto, ExprAST *body)
- : Proto(proto), Body(body) {}
-
- };
-
- //===----------------------------------------------------------------------===//
- // 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;
- }
-
- /// primary
- /// ::= identifierexpr
- /// ::= numberexpr
- /// ::= parenexpr
- 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();
- }
- }
-
- /// 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();
- }
-
- //===----------------------------------------------------------------------===//
- // Top-Level parsing
- //===----------------------------------------------------------------------===//
-
- static void HandleDefinition() {
- if (ParseDefinition()) {
- fprintf(stderr, "Parsed a function definition.\n");
- } else {
- // Skip token for error recovery.
- getNextToken();
- }
- }
-
- static void HandleExtern() {
- if (ParseExtern()) {
- fprintf(stderr, "Parsed an extern\n");
- } else {
- // Skip token for error recovery.
- getNextToken();
- }
- }
-
- static void HandleTopLevelExpression() {
- // Evaluate a top-level expression into an anonymous function.
- if (ParseTopLevelExpr()) {
- fprintf(stderr, "Parsed a top-level expr\n");
- } 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;
- }
- }
- }
-
- //===----------------------------------------------------------------------===//
- // Main driver code.
- //===----------------------------------------------------------------------===//
-
- int main() {
- // 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();
-
- // Run the main "interpreter loop" now.
- MainLoop();
-
- return 0;
- }
+.. literalinclude:: ../../examples/Kaleidoscope/Chapter2/toy.cpp
+ :language: c++
`Next: Implementing Code Generation to LLVM IR <LangImpl3.html>`_
Modified: llvm/trunk/docs/tutorial/LangImpl3.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/tutorial/LangImpl3.rst?rev=183607&r1=183606&r2=183607&view=diff
==============================================================================
--- llvm/trunk/docs/tutorial/LangImpl3.rst (original)
+++ llvm/trunk/docs/tutorial/LangImpl3.rst Sat Jun 8 04:03:03 2013
@@ -587,574 +587,8 @@ our makefile/command line about which op
Here is the code:
-.. code-block:: c++
-
- // To build this:
- // See example below.
-
- #include "llvm/DerivedTypes.h"
- #include "llvm/IRBuilder.h"
- #include "llvm/LLVMContext.h"
- #include "llvm/Module.h"
- #include "llvm/Analysis/Verifier.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
- };
-
- 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;
- 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();
- };
-
- /// 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;
- }
-
- /// primary
- /// ::= identifierexpr
- /// ::= numberexpr
- /// ::= parenexpr
- 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();
- }
- }
-
- /// 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;
-
- 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");
- }
-
- 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);
-
- return TheFunction;
- }
-
- // Error reading body, remove function.
- TheFunction->eraseFromParent();
- return 0;
- }
-
- //===----------------------------------------------------------------------===//
- // Top-Level parsing and JIT Driver
- //===----------------------------------------------------------------------===//
-
- 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()) {
- fprintf(stderr, "Read top-level expression:");
- LF->dump();
- }
- } 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() {
- 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);
-
- // Run the main "interpreter loop" now.
- MainLoop();
-
- // Print out all of the generated code.
- TheModule->dump();
-
- return 0;
- }
+.. literalinclude:: ../../examples/Kaleidoscope/Chapter3/toy.cpp
+ :language: c++
`Next: Adding JIT and Optimizer Support <LangImpl4.html>`_
Modified: llvm/trunk/docs/tutorial/LangImpl4.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/tutorial/LangImpl4.rst?rev=183607&r1=183606&r2=183607&view=diff
==============================================================================
--- llvm/trunk/docs/tutorial/LangImpl4.rst (original)
+++ llvm/trunk/docs/tutorial/LangImpl4.rst Sat Jun 8 04:03:03 2013
@@ -438,624 +438,8 @@ properly at runtime.
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
- };
-
- 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;
- 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();
- };
-
- /// 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;
- }
-
- /// primary
- /// ::= identifierexpr
- /// ::= numberexpr
- /// ::= parenexpr
- 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();
- }
- }
-
- /// 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");
- }
-
- 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()) {
- fprintf(stderr, "Read top-level expression:");
- LF->dump();
-
- // 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/Chapter4/toy.cpp
+ :language: c++
`Next: Extending the language: control flow <LangImpl5.html>`_
Modified: llvm/trunk/docs/tutorial/LangImpl5.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/tutorial/LangImpl5.rst?rev=183607&r1=183606&r2=183607&view=diff
==============================================================================
--- llvm/trunk/docs/tutorial/LangImpl5.rst (original)
+++ llvm/trunk/docs/tutorial/LangImpl5.rst Sat Jun 8 04:03:03 2013
@@ -742,866 +742,8 @@ the if/then/else and for expressions.. T
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>`_
Modified: llvm/trunk/docs/tutorial/LangImpl6.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/tutorial/LangImpl6.rst?rev=183607&r1=183606&r2=183607&view=diff
==============================================================================
--- llvm/trunk/docs/tutorial/LangImpl6.rst (original)
+++ llvm/trunk/docs/tutorial/LangImpl6.rst Sat Jun 8 04:03:03 2013
@@ -742,984 +742,8 @@ will cause problems on Windows.
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,
-
- // operators
- tok_binary = -11, tok_unary = -12
- };
-
- 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;
- if (IdentifierStr == "binary") return tok_binary;
- if (IdentifierStr == "unary") return tok_unary;
- 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();
- };
-
- /// UnaryExprAST - Expression class for a unary operator.
- class UnaryExprAST : public ExprAST {
- char Opcode;
- ExprAST *Operand;
- public:
- UnaryExprAST(char opcode, ExprAST *operand)
- : Opcode(opcode), Operand(operand) {}
- 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), as well as if it is an operator.
- class PrototypeAST {
- std::string Name;
- std::vector<std::string> Args;
- bool isOperator;
- unsigned Precedence; // Precedence if a binary op.
- public:
- PrototypeAST(const std::string &name, const std::vector<std::string> &args,
- bool isoperator = false, unsigned prec = 0)
- : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
-
- bool isUnaryOp() const { return isOperator && Args.size() == 1; }
- bool isBinaryOp() const { return isOperator && Args.size() == 2; }
-
- char getOperatorName() const {
- assert(isUnaryOp() || isBinaryOp());
- return Name[Name.size()-1];
- }
-
- unsigned getBinaryPrecedence() const { return Precedence; }
-
- 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();
- }
- }
-
- /// unary
- /// ::= primary
- /// ::= '!' unary
- static ExprAST *ParseUnary() {
- // If the current token is not an operator, it must be a primary expr.
- if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
- return ParsePrimary();
-
- // If this is a unary operator, read it.
- int Opc = CurTok;
- getNextToken();
- if (ExprAST *Operand = ParseUnary())
- return new UnaryExprAST(Opc, Operand);
- return 0;
- }
-
- /// binoprhs
- /// ::= ('+' unary)*
- 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 unary expression after the binary operator.
- ExprAST *RHS = ParseUnary();
- 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
- /// ::= unary binoprhs
- ///
- static ExprAST *ParseExpression() {
- ExprAST *LHS = ParseUnary();
- if (!LHS) return 0;
-
- return ParseBinOpRHS(0, LHS);
- }
-
- /// prototype
- /// ::= id '(' id* ')'
- /// ::= binary LETTER number? (id, id)
- /// ::= unary LETTER (id)
- static PrototypeAST *ParsePrototype() {
- std::string FnName;
-
- unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
- unsigned BinaryPrecedence = 30;
-
- switch (CurTok) {
- default:
- return ErrorP("Expected function name in prototype");
- case tok_identifier:
- FnName = IdentifierStr;
- Kind = 0;
- getNextToken();
- break;
- case tok_unary:
- getNextToken();
- if (!isascii(CurTok))
- return ErrorP("Expected unary operator");
- FnName = "unary";
- FnName += (char)CurTok;
- Kind = 1;
- getNextToken();
- break;
- case tok_binary:
- getNextToken();
- if (!isascii(CurTok))
- return ErrorP("Expected binary operator");
- FnName = "binary";
- FnName += (char)CurTok;
- Kind = 2;
- getNextToken();
-
- // Read the precedence if present.
- if (CurTok == tok_number) {
- if (NumVal < 1 || NumVal > 100)
- return ErrorP("Invalid precedecnce: must be 1..100");
- BinaryPrecedence = (unsigned)NumVal;
- getNextToken();
- }
- break;
- }
-
- 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 ')'.
-
- // Verify right number of names for operator.
- if (Kind && ArgNames.size() != Kind)
- return ErrorP("Invalid number of operands for operator");
-
- return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
- }
-
- /// 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 *UnaryExprAST::Codegen() {
- Value *OperandV = Operand->Codegen();
- if (OperandV == 0) return 0;
-
- Function *F = TheModule->getFunction(std::string("unary")+Opcode);
- if (F == 0)
- return ErrorV("Unknown unary operator");
-
- return Builder.CreateCall(F, OperandV, "unop");
- }
-
- 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: break;
- }
-
- // If it wasn't a builtin binary operator, it must be a user defined one. Emit
- // a call to it.
- Function *F = TheModule->getFunction(std::string("binary")+Op);
- assert(F && "binary operator not found!");
-
- Value *Ops[2] = { L, R };
- return Builder.CreateCall(F, Ops, "binop");
- }
-
- 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;
-
- // If this is an operator, install it.
- if (Proto->isBinaryOp())
- BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
-
- // 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();
-
- if (Proto->isBinaryOp())
- BinopPrecedence.erase(Proto->getOperatorName());
- 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;
- }
-
- /// printd - printf that takes a double prints it as "%f\n", returning 0.
- extern "C"
- double printd(double X) {
- printf("%f\n", 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/Chapter6/toy.cpp
+ :language: c++
`Next: Extending the language: mutable variables / SSA
construction <LangImpl7.html>`_
Modified: llvm/trunk/docs/tutorial/LangImpl7.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/tutorial/LangImpl7.rst?rev=183607&r1=183606&r2=183607&view=diff
==============================================================================
--- llvm/trunk/docs/tutorial/LangImpl7.rst (original)
+++ llvm/trunk/docs/tutorial/LangImpl7.rst Sat Jun 8 04:03:03 2013
@@ -853,1151 +853,8 @@ mutable variables and var/in support. To
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,
-
- // operators
- tok_binary = -11, tok_unary = -12,
-
- // var definition
- tok_var = -13
- };
-
- 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;
- if (IdentifierStr == "binary") return tok_binary;
- if (IdentifierStr == "unary") return tok_unary;
- if (IdentifierStr == "var") return tok_var;
- 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) {}
- const std::string &getName() const { return Name; }
- virtual Value *Codegen();
- };
-
- /// UnaryExprAST - Expression class for a unary operator.
- class UnaryExprAST : public ExprAST {
- char Opcode;
- ExprAST *Operand;
- public:
- UnaryExprAST(char opcode, ExprAST *operand)
- : Opcode(opcode), Operand(operand) {}
- 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();
- };
-
- /// VarExprAST - Expression class for var/in
- class VarExprAST : public ExprAST {
- std::vector<std::pair<std::string, ExprAST*> > VarNames;
- ExprAST *Body;
- public:
- VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
- ExprAST *body)
- : VarNames(varnames), 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), as well as if it is an operator.
- class PrototypeAST {
- std::string Name;
- std::vector<std::string> Args;
- bool isOperator;
- unsigned Precedence; // Precedence if a binary op.
- public:
- PrototypeAST(const std::string &name, const std::vector<std::string> &args,
- bool isoperator = false, unsigned prec = 0)
- : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
-
- bool isUnaryOp() const { return isOperator && Args.size() == 1; }
- bool isBinaryOp() const { return isOperator && Args.size() == 2; }
-
- char getOperatorName() const {
- assert(isUnaryOp() || isBinaryOp());
- return Name[Name.size()-1];
- }
-
- unsigned getBinaryPrecedence() const { return Precedence; }
-
- Function *Codegen();
-
- void CreateArgumentAllocas(Function *F);
- };
-
- /// 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);
- }
-
- /// varexpr ::= 'var' identifier ('=' expression)?
- // (',' identifier ('=' expression)?)* 'in' expression
- static ExprAST *ParseVarExpr() {
- getNextToken(); // eat the var.
-
- std::vector<std::pair<std::string, ExprAST*> > VarNames;
-
- // At least one variable name is required.
- if (CurTok != tok_identifier)
- return Error("expected identifier after var");
-
- while (1) {
- std::string Name = IdentifierStr;
- getNextToken(); // eat identifier.
-
- // Read the optional initializer.
- ExprAST *Init = 0;
- if (CurTok == '=') {
- getNextToken(); // eat the '='.
-
- Init = ParseExpression();
- if (Init == 0) return 0;
- }
-
- VarNames.push_back(std::make_pair(Name, Init));
-
- // End of var list, exit loop.
- if (CurTok != ',') break;
- getNextToken(); // eat the ','.
-
- if (CurTok != tok_identifier)
- return Error("expected identifier list after var");
- }
-
- // At this point, we have to have 'in'.
- if (CurTok != tok_in)
- return Error("expected 'in' keyword after 'var'");
- getNextToken(); // eat 'in'.
-
- ExprAST *Body = ParseExpression();
- if (Body == 0) return 0;
-
- return new VarExprAST(VarNames, Body);
- }
-
- /// primary
- /// ::= identifierexpr
- /// ::= numberexpr
- /// ::= parenexpr
- /// ::= ifexpr
- /// ::= forexpr
- /// ::= varexpr
- 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();
- case tok_var: return ParseVarExpr();
- }
- }
-
- /// unary
- /// ::= primary
- /// ::= '!' unary
- static ExprAST *ParseUnary() {
- // If the current token is not an operator, it must be a primary expr.
- if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
- return ParsePrimary();
-
- // If this is a unary operator, read it.
- int Opc = CurTok;
- getNextToken();
- if (ExprAST *Operand = ParseUnary())
- return new UnaryExprAST(Opc, Operand);
- return 0;
- }
-
- /// binoprhs
- /// ::= ('+' unary)*
- 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 unary expression after the binary operator.
- ExprAST *RHS = ParseUnary();
- 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
- /// ::= unary binoprhs
- ///
- static ExprAST *ParseExpression() {
- ExprAST *LHS = ParseUnary();
- if (!LHS) return 0;
-
- return ParseBinOpRHS(0, LHS);
- }
-
- /// prototype
- /// ::= id '(' id* ')'
- /// ::= binary LETTER number? (id, id)
- /// ::= unary LETTER (id)
- static PrototypeAST *ParsePrototype() {
- std::string FnName;
-
- unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
- unsigned BinaryPrecedence = 30;
-
- switch (CurTok) {
- default:
- return ErrorP("Expected function name in prototype");
- case tok_identifier:
- FnName = IdentifierStr;
- Kind = 0;
- getNextToken();
- break;
- case tok_unary:
- getNextToken();
- if (!isascii(CurTok))
- return ErrorP("Expected unary operator");
- FnName = "unary";
- FnName += (char)CurTok;
- Kind = 1;
- getNextToken();
- break;
- case tok_binary:
- getNextToken();
- if (!isascii(CurTok))
- return ErrorP("Expected binary operator");
- FnName = "binary";
- FnName += (char)CurTok;
- Kind = 2;
- getNextToken();
-
- // Read the precedence if present.
- if (CurTok == tok_number) {
- if (NumVal < 1 || NumVal > 100)
- return ErrorP("Invalid precedecnce: must be 1..100");
- BinaryPrecedence = (unsigned)NumVal;
- getNextToken();
- }
- break;
- }
-
- 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 ')'.
-
- // Verify right number of names for operator.
- if (Kind && ArgNames.size() != Kind)
- return ErrorP("Invalid number of operands for operator");
-
- return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
- }
-
- /// 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, AllocaInst*> NamedValues;
- static FunctionPassManager *TheFPM;
-
- Value *ErrorV(const char *Str) { Error(Str); return 0; }
-
- /// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
- /// the function. This is used for mutable variables etc.
- static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
- const std::string &VarName) {
- IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
- TheFunction->getEntryBlock().begin());
- return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
- VarName.c_str());
- }
-
- Value *NumberExprAST::Codegen() {
- return ConstantFP::get(getGlobalContext(), APFloat(Val));
- }
-
- Value *VariableExprAST::Codegen() {
- // Look this variable up in the function.
- Value *V = NamedValues[Name];
- if (V == 0) return ErrorV("Unknown variable name");
-
- // Load the value.
- return Builder.CreateLoad(V, Name.c_str());
- }
-
- Value *UnaryExprAST::Codegen() {
- Value *OperandV = Operand->Codegen();
- if (OperandV == 0) return 0;
-
- Function *F = TheModule->getFunction(std::string("unary")+Opcode);
- if (F == 0)
- return ErrorV("Unknown unary operator");
-
- return Builder.CreateCall(F, OperandV, "unop");
- }
-
- Value *BinaryExprAST::Codegen() {
- // Special case '=' because we don't want to emit the LHS as an expression.
- if (Op == '=') {
- // Assignment requires the LHS to be an identifier.
- VariableExprAST *LHSE = dynamic_cast<VariableExprAST*>(LHS);
- if (!LHSE)
- return ErrorV("destination of '=' must be a variable");
- // Codegen the RHS.
- Value *Val = RHS->Codegen();
- if (Val == 0) return 0;
-
- // Look up the name.
- Value *Variable = NamedValues[LHSE->getName()];
- if (Variable == 0) return ErrorV("Unknown variable name");
-
- Builder.CreateStore(Val, Variable);
- return Val;
- }
-
- 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: break;
- }
-
- // If it wasn't a builtin binary operator, it must be a user defined one. Emit
- // a call to it.
- Function *F = TheModule->getFunction(std::string("binary")+Op);
- assert(F && "binary operator not found!");
-
- Value *Ops[2] = { L, R };
- return Builder.CreateCall(F, Ops, "binop");
- }
-
- 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:
- // var = alloca double
- // ...
- // start = startexpr
- // store start -> var
- // goto loop
- // loop:
- // ...
- // bodyexpr
- // ...
- // loopend:
- // step = stepexpr
- // endcond = endexpr
- //
- // curvar = load var
- // nextvar = curvar + step
- // store nextvar -> var
- // br endcond, loop, endloop
- // outloop:
-
- Function *TheFunction = Builder.GetInsertBlock()->getParent();
-
- // Create an alloca for the variable in the entry block.
- AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
-
- // Emit the start code first, without 'variable' in scope.
- Value *StartVal = Start->Codegen();
- if (StartVal == 0) return 0;
-
- // Store the value into the alloca.
- Builder.CreateStore(StartVal, Alloca);
-
- // Make the new basic block for the loop header, inserting after current
- // block.
- 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);
-
- // 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.
- AllocaInst *OldVal = NamedValues[VarName];
- NamedValues[VarName] = Alloca;
-
- // 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));
- }
-
- // Compute the end condition.
- Value *EndCond = End->Codegen();
- if (EndCond == 0) return EndCond;
-
- // Reload, increment, and restore the alloca. This handles the case where
- // the body of the loop mutates the variable.
- Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
- Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
- Builder.CreateStore(NextVar, Alloca);
-
- // 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 *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);
-
- // 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()));
- }
-
- Value *VarExprAST::Codegen() {
- std::vector<AllocaInst *> OldBindings;
-
- Function *TheFunction = Builder.GetInsertBlock()->getParent();
-
- // Register all variables and emit their initializer.
- for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
- const std::string &VarName = VarNames[i].first;
- ExprAST *Init = VarNames[i].second;
-
- // Emit the initializer before adding the variable to scope, this prevents
- // the initializer from referencing the variable itself, and permits stuff
- // like this:
- // var a = 1 in
- // var a = a in ... # refers to outer 'a'.
- Value *InitVal;
- if (Init) {
- InitVal = Init->Codegen();
- if (InitVal == 0) return 0;
- } else { // If not specified, use 0.0.
- InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
- }
-
- AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
- Builder.CreateStore(InitVal, Alloca);
-
- // Remember the old variable binding so that we can restore the binding when
- // we unrecurse.
- OldBindings.push_back(NamedValues[VarName]);
-
- // Remember this binding.
- NamedValues[VarName] = Alloca;
- }
-
- // Codegen the body, now that all vars are in scope.
- Value *BodyVal = Body->Codegen();
- if (BodyVal == 0) return 0;
-
- // Pop all our variables from scope.
- for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
- NamedValues[VarNames[i].first] = OldBindings[i];
-
- // Return the body computation.
- return BodyVal;
- }
-
- 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]);
-
- return F;
- }
-
- /// CreateArgumentAllocas - Create an alloca for each argument and register the
- /// argument in the symbol table so that references to it will succeed.
- void PrototypeAST::CreateArgumentAllocas(Function *F) {
- Function::arg_iterator AI = F->arg_begin();
- for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
- // Create an alloca for this variable.
- AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
-
- // Store the initial value into the alloca.
- Builder.CreateStore(AI, Alloca);
-
- // Add arguments to variable symbol table.
- NamedValues[Args[Idx]] = Alloca;
- }
- }
-
- Function *FunctionAST::Codegen() {
- NamedValues.clear();
-
- Function *TheFunction = Proto->Codegen();
- if (TheFunction == 0)
- return 0;
-
- // If this is an operator, install it.
- if (Proto->isBinaryOp())
- BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
-
- // Create a new basic block to start insertion into.
- BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
- Builder.SetInsertPoint(BB);
-
- // Add all arguments to the symbol table and create their allocas.
- Proto->CreateArgumentAllocas(TheFunction);
-
- 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();
-
- if (Proto->isBinaryOp())
- BinopPrecedence.erase(Proto->getOperatorName());
- 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;
- }
-
- /// printd - printf that takes a double prints it as "%f\n", returning 0.
- extern "C"
- double printd(double X) {
- printf("%f\n", X);
- return 0;
- }
-
- //===----------------------------------------------------------------------===//
- // Main driver code.
- //===----------------------------------------------------------------------===//
-
- int main() {
- InitializeNativeTarget();
- LLVMContext &Context = getGlobalContext();
-
- // Install standard binary operators.
- // 1 is lowest precedence.
- BinopPrecedence['='] = 2;
- 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());
- // Promote allocas to registers.
- OurFPM.add(createPromoteMemoryToRegisterPass());
- // 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/Chapter7/toy.cpp
+ :language: c++
`Next: Conclusion and other useful LLVM tidbits <LangImpl8.html>`_
More information about the llvm-commits
mailing list