functioning version of chapter 3 of tutorial

source/Ast.cpp

@@ -0,0 +1,129 @@
+#include "Ast.h"
+
+using namespace ast;
+
+// attributes added from chapter 3 of the tutorial
+std::unique_ptr<Module> AstTree::TheModule = make_unique<Module>("my cool jit", getGlobalContext());;
+IRBuilder<> AstTree::Builder(getGlobalContext());
+std::map<std::string, Value *> AstTree::NamedValues;
+
+// error method from chapter 3
+// HACK: duplicated function already present in example
+std::unique_ptr<ExprAST> Error_Ast(const char *Str) {
+  fprintf(stderr, "Error: %s\n", Str);
+  return nullptr;
+}
+
+Value *ErrorV(const char *Str) {
+  Error_Ast(Str);
+  return nullptr;
+}
+
+Value *NumberExprAST::codegen() {
+  return ConstantFP::get(getGlobalContext(), APFloat(Val));
+}
+
+Value *VariableExprAST::codegen() {
+  // Look this variable up in the function.
+  Value *V = AstTree::NamedValues[Name];
+  if (!V)
+  ErrorV("Unknown variable name");
+  return V;
+}
+
+Value *BinaryExprAST::codegen() {
+  Value *L = LHS->codegen();
+  Value *R = RHS->codegen();
+  if (!L || !R)
+  return nullptr;
+
+  switch (Op) {
+    case '+':
+    return AstTree::Builder.CreateFAdd(L, R, "addtmp");
+    case '-':
+    return AstTree::Builder.CreateFSub(L, R, "subtmp");
+    case '*':
+    return AstTree::Builder.CreateFMul(L, R, "multmp");
+    case '<':
+    L = AstTree::Builder.CreateFCmpULT(L, R, "cmptmp");
+    // Convert bool 0/1 to double 0.0 or 1.0
+    return AstTree::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 = AstTree::TheModule->getFunction(Callee);
+  if (!CalleeF)
+  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())
+    return nullptr;
+  }
+  return AstTree::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, AstTree::TheModule.get());
+
+  // Set names for all arguments.
+  unsigned Idx = 0;
+  for (auto &Arg : F->args())
+    Arg.setName(Args[Idx++]);
+
+  return F;
+}
+
+Function *FunctionAST::codegen() {
+  // First, check for an existing function from a previous 'extern' declaration.
+  Function *TheFunction = AstTree::TheModule->getFunction(Proto->getName());
+
+  if (!TheFunction)
+  TheFunction = Proto->codegen();
+
+  if (!TheFunction)
+  return nullptr;
+
+  if (!TheFunction->empty())
+  return (Function*)ErrorV("Function cannot be redefined.");
+
+  // Create a new basic block to start insertion into.
+  BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
+  AstTree::Builder.SetInsertPoint(BB);
+
+  // Record the function arguments in the NamedValues map.
+  AstTree::NamedValues.clear();
+  for (auto &Arg : TheFunction->args())
+  AstTree::NamedValues[Arg.getName()] = &Arg;
+
+  if (Value *RetVal = Body->codegen()) {
+    // Finish off the function.
+    AstTree::Builder.CreateRet(RetVal);
+
+    // Validate the generated code, checking for consistency.
+    verifyFunction(*TheFunction);
+
+    return TheFunction;
+  }
+
+  // Error reading body, remove function.
+  TheFunction->eraseFromParent();
+  return nullptr;
+}

source/Ast.h

@@ -0,0 +1,109 @@
+#ifndef AST_H
+#define AST_H
+
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Verifier.h"
+#include <cctype>
+#include <cstdio>
+#include <map>
+#include <string>
+#include <vector>
+
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Abstract Syntax Tree (aka Parse Tree)
+//===----------------------------------------------------------------------===//
+namespace ast{
+// struct instantiated by the 'main' to access data structures if llvm IR.
+struct AstTree {
+public:
+  static std::unique_ptr<llvm::Module> TheModule;
+  static llvm::IRBuilder<> Builder;
+  static std::map<std::string, llvm::Value *> NamedValues;
+  static void InitializeModuleAndPassManager();
+};
+
+/// ExprAST - Base class for all expression nodes.
+
+class ExprAST {
+public:
+  virtual ~ExprAST() {}
+  virtual llvm::Value *codegen() = 0;
+};
+
+/// NumberExprAST - Expression class for numeric literals like "1.0".
+class NumberExprAST : public ExprAST {
+  double Val;
+
+public:
+  NumberExprAST(double Val) : Val(Val) {}
+  Value *codegen() override;
+};
+
+/// VariableExprAST - Expression class for referencing a variable, like "a".
+class VariableExprAST : public ExprAST {
+  std::string Name;
+
+public:
+  VariableExprAST(const std::string &Name) : Name(Name) {}
+  Value *codegen() override;
+};
+
+/// BinaryExprAST - Expression class for a binary operator.
+class BinaryExprAST : public ExprAST {
+  char Op;
+  std::unique_ptr<ExprAST> LHS, RHS;
+
+public:
+  BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
+                std::unique_ptr<ExprAST> RHS)
+      : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {}
+  Value *codegen() override;
+};
+
+/// CallExprAST - Expression class for function calls.
+class CallExprAST : public ExprAST {
+  std::string Callee;
+  std::vector<std::unique_ptr<ExprAST>> Args;
+
+public:
+  CallExprAST(const std::string &Callee,
+              std::vector<std::unique_ptr<ExprAST>> Args)
+      : Callee(Callee), Args(std::move(Args)) {}
+  Value *codegen() override;
+};
+
+/// 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, std::vector<std::string> Args)
+      : Name(Name), Args(std::move(Args)) {}
+  Function *codegen();
+  const std::string &getName() const { return Name; }
+};
+
+/// FunctionAST - This class represents a function definition itself.
+class FunctionAST {
+  std::unique_ptr<PrototypeAST> Proto;
+  std::unique_ptr<ExprAST> Body;
+
+public:
+  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
+              std::unique_ptr<ExprAST> Body)
+      : Proto(std::move(Proto)), Body(std::move(Body)) {}
+  Function *codegen();
+};
+
+// method added from chapter 3 of the tutorial
+} // end anonymous namespace
+
+#endif

source/CMakeLists.txt

@@ -0,0 +1,23 @@
+cmake_minimum_required(VERSION 3.5)
+project(llvm_tutorial CXX)
+
+find_package(LLVM REQUIRED CONFIG)
+
+
+message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION}")
+message(STATUS "Using LLVMConfig.cmake in: ${LLVM_DIR}")
+
+# Options to compile correctly the llvm tutorial
+add_compile_options(-std=c++14 -g -O3)
+
+include_directories(${LLVM_INCLUDE_DIRS})
+add_definitions(${LLVM_DEFINITIONS})
+
+add_executable(kaleidoscope LexerParser.cpp Ast.cpp)
+
+# Find the libraries that correspond to the LLVM components
+# that we wish to use
+llvm_map_components_to_libnames(llvm_libs core support native mcjit)
+
+# Link against LLVM libraries
+target_link_libraries(kaleidoscope ${llvm_libs})

source/LexerParser.cpp

@@ -0,0 +1,399 @@
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Verifier.h"
+#include <cctype>
+#include <cstdio>
+#include <map>
+#include <string>
+#include <vector>
+#include "Ast.h"
+
+using namespace llvm;
+using namespace ast;
+
+
+namespace helper {
+// Cloning make_unique here until it's standard in C++14.
+// Using a namespace to avoid conflicting with MSVC's std::make_unique (which
+// ADL can sometimes find in unqualified calls).
+template <class T, class... Args>
+static
+    typename std::enable_if<!std::is_array<T>::value, std::unique_ptr<T>>::type
+    make_unique(Args &&... args) {
+  return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
+}
+}
+
+//===----------------------------------------------------------------------===//
+// 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(), nullptr);
+    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;
+}
+
+//===----------------------------------------------------------------------===//
+// 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.
+std::unique_ptr<ExprAST> Error(const char *Str) {
+  fprintf(stderr, "Error: %s\n", Str);
+  return nullptr;
+}
+std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
+  Error(Str);
+  return nullptr;
+}
+
+static std::unique_ptr<ExprAST> ParseExpression();
+
+/// numberexpr ::= number
+static std::unique_ptr<ExprAST> ParseNumberExpr() {
+  auto Result = helper::make_unique<NumberExprAST>(NumVal);
+  getNextToken(); // consume the number
+  return std::move(Result);
+}
+
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+  getNextToken(); // eat (.
+  auto V = ParseExpression();
+  if (!V)
+    return nullptr;
+
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken(); // eat ).
+  return V;
+}
+
+/// identifierexpr
+///   ::= identifier
+///   ::= identifier '(' expression* ')'
+static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
+  std::string IdName = IdentifierStr;
+
+  getNextToken(); // eat identifier.
+
+  if (CurTok != '(') // Simple variable ref.
+    return helper::make_unique<VariableExprAST>(IdName);
+
+  // Call.
+  getNextToken(); // eat (
+  std::vector<std::unique_ptr<ExprAST>> Args;
+  if (CurTok != ')') {
+    while (1) {
+      if (auto Arg = ParseExpression())
+        Args.push_back(std::move(Arg));
+      else
+        return nullptr;
+
+      if (CurTok == ')')
+        break;
+
+      if (CurTok != ',')
+        return Error("Expected ')' or ',' in argument list");
+      getNextToken();
+    }
+  }
+
+  // Eat the ')'.
+  getNextToken();
+
+  return helper::make_unique<CallExprAST>(IdName, std::move(Args));
+}
+
+/// primary
+///   ::= identifierexpr
+///   ::= numberexpr
+///   ::= parenexpr
+static std::unique_ptr<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 std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
+                                              std::unique_ptr<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.
+    auto RHS = ParsePrimary();
+    if (!RHS)
+      return nullptr;
+
+    // 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, std::move(RHS));
+      if (!RHS)
+        return nullptr;
+    }
+
+    // Merge LHS/RHS.
+    LHS = helper::make_unique<BinaryExprAST>(BinOp, std::move(LHS),
+                                             std::move(RHS));
+  }
+}
+
+/// expression
+///   ::= primary binoprhs
+///
+static std::unique_ptr<ExprAST> ParseExpression() {
+  auto LHS = ParsePrimary();
+  if (!LHS)
+    return nullptr;
+
+  return ParseBinOpRHS(0, std::move(LHS));
+}
+
+/// prototype
+///   ::= id '(' id* ')'
+static std::unique_ptr<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 helper::make_unique<PrototypeAST>(FnName, std::move(ArgNames));
+}
+
+/// definition ::= 'def' prototype expression
+static std::unique_ptr<FunctionAST> ParseDefinition() {
+  getNextToken(); // eat def.
+  auto Proto = ParsePrototype();
+  if (!Proto)
+    return nullptr;
+
+  if (auto E = ParseExpression())
+    return helper::make_unique<FunctionAST>(std::move(Proto), std::move(E));
+  return nullptr;
+}
+
+/// toplevelexpr ::= expression
+static std::unique_ptr<FunctionAST> ParseTopLevelExpr() {
+  if (auto E = ParseExpression()) {
+    // Make an anonymous proto.
+    auto Proto = helper::make_unique<PrototypeAST>("__anon_expr",
+                                                   std::vector<std::string>());
+    return helper::make_unique<FunctionAST>(std::move(Proto), std::move(E));
+  }
+  return nullptr;
+}
+
+/// external ::= 'extern' prototype
+static std::unique_ptr<PrototypeAST> ParseExtern() {
+  getNextToken(); // eat extern.
+  return ParsePrototype();
+}
+
+//===----------------------------------------------------------------------===//
+// Top-Level parsing
+//===----------------------------------------------------------------------===//
+
+static void HandleDefinition() {
+  if (auto FnAST = ParseDefinition()) {
+    if (auto *FnIR = FnAST->codegen()) {
+      fprintf(stderr, "Read function definition:");
+      FnIR->dump();
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleExtern() {
+  if (auto ProtoAST = ParseExtern()) {
+    if (auto *FnIR = ProtoAST->codegen()) {
+      fprintf(stderr, "Read extern: ");
+      FnIR->dump();
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleTopLevelExpression() {
+  // Evaluate a top-level expression into an anonymous function.
+  if (auto FnAST = ParseTopLevelExpr()) {
+    if (auto *FnIR = FnAST->codegen()) {
+      fprintf(stderr, "Read top-level expression:");
+      FnIR->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 ';': // ignore top-level semicolons.
+      getNextToken();
+      break;
+    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();
+
+  AstTree::TheModule->dump();
+
+  return 0;
+}