examples/toy/Ch1/toyc.cpp

//===- toyc.cpp - The Toy Compiler ----------------------------------------===//
//
// Copyright 2019 The MLIR Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// =============================================================================
//
// This file implements the entry point for the Toy compiler.
//
//===----------------------------------------------------------------------===//

#include "toy/Parser.h"

#include "llvm/ADT/StringRef.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"

using namespace toy;
namespace cl = llvm::cl;

static cl::opt<std::string> InputFilename(cl::Positional,
                                          cl::desc("<input toy file>"),
                                          cl::init("-"),
                                          cl::value_desc("filename"));
namespace {
enum Action { None, DumpAST };
}

static cl::opt<enum Action>
    emitAction("emit", cl::desc("Select the kind of output desired"),
               cl::values(clEnumValN(DumpAST, "ast", "output the AST dump")));

/// Returns a Toy AST resulting from parsing the file or a nullptr on error.
std::unique_ptr<toy::ModuleAST> parseInputFile(llvm::StringRef filename) {
  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> FileOrErr =
      llvm::MemoryBuffer::getFileOrSTDIN(filename);
  if (std::error_code EC = FileOrErr.getError()) {
    llvm::errs() << "Could not open input file: " << EC.message() << "\n";
    return nullptr;
  }
  auto buffer = FileOrErr.get()->getBuffer();
  LexerBuffer lexer(buffer.begin(), buffer.end(), filename);
  Parser parser(lexer);
  return parser.ParseModule();
}

int main(int argc, char **argv) {
  cl::ParseCommandLineOptions(argc, argv, "toy compiler\n");

  auto moduleAST = parseInputFile(InputFilename);
  if (!moduleAST)
    return 1;

  switch (emitAction) {
  case Action::DumpAST:
    dump(*moduleAST);
    return 0;
  default:
    llvm::errs() << "No action specified (parsing only?), use -emit=<action>\n";
  }

  return 0;
}