mlir/examples/toy/Ch1/toyc.cpp

   1 //===- toyc.cpp - The Toy Compiler ----------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the entry point for the Toy compiler.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "toy/AST.h"
  14 #include "toy/Lexer.h"
  15 #include "toy/Parser.h"
  16
  17 #include "llvm/ADT/StringRef.h"
  18 #include "llvm/Support/CommandLine.h"
  19 #include "llvm/Support/ErrorOr.h"
  20 #include "llvm/Support/MemoryBuffer.h"
  21 #include "llvm/Support/raw_ostream.h"
  22 #include <memory>
  23 #include <string>
  24 #include <system_error>
  25
  26 using namespace toy;
  27 namespace cl = llvm::cl;
  28
  29 static cl::opt<std::string> inputFilename(cl::Positional,
  30                                           cl::desc("<input toy file>"),
  31                                           cl::init("-"),
  32                                           cl::value_desc("filename"));
  33 namespace {
  34 enum Action { None, DumpAST };
  35 } // namespace
  36
  37 static cl::opt<enum Action>
  38     emitAction("emit", cl::desc("Select the kind of output desired"),
  39                cl::values(clEnumValN(DumpAST, "ast", "output the AST dump")));
  40
  41 /// Returns a Toy AST resulting from parsing the file or a nullptr on error.
  42 std::unique_ptr<toy::ModuleAST> parseInputFile(llvm::StringRef filename) {
  43   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> fileOrErr =
  44       llvm::MemoryBuffer::getFileOrSTDIN(filename);
  45   if (std::error_code ec = fileOrErr.getError()) {
  46     llvm::errs() << "Could not open input file: " << ec.message() << "\n";
  47     return nullptr;
  48   }
  49   auto buffer = fileOrErr.get()->getBuffer();
  50   LexerBuffer lexer(buffer.begin(), buffer.end(), std::string(filename));
  51   Parser parser(lexer);
  52   return parser.parseModule();
  53 }
  54
  55 int main(int argc, char **argv) {
  56   cl::ParseCommandLineOptions(argc, argv, "toy compiler\n");
  57
  58   auto moduleAST = parseInputFile(inputFilename);
  59   if (!moduleAST)
  60     return 1;
  61
  62   switch (emitAction) {
  63   case Action::DumpAST:
  64     dump(*moduleAST);
  65     return 0;
  66   default:
  67     llvm::errs() << "No action specified (parsing only?), use -emit=<action>\n";
  68   }
  69
  70   return 0;
  71 }