src/tools/wasm-dis.cpp

/*
 * Copyright 2016 WebAssembly Community Group participants
 *
 * 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.
 */

//
// wasm2asm console tool
//

#include "support/colors.h"
#include "support/command-line.h"
#include "support/file.h"
#include "wasm-binary.h"
#include "wasm-printing.h"

using namespace cashew;
using namespace wasm;

int main(int argc, const char *argv[]) {
  std::string sourceMapFilename;
  Options options("wasm-dis", "Un-assemble a .wasm (WebAssembly binary format) into a .wast (WebAssembly text format)");
  options.add("--output", "-o", "Output file (stdout if not specified)",
              Options::Arguments::One,
              [](Options *o, const std::string& argument) {
                o->extra["output"] = argument;
                Colors::disable();
              })
      .add("--source-map", "-sm", "Consume source map from the specified file to add location information",
           Options::Arguments::One,
           [&sourceMapFilename](Options *o, const std::string& argument) { sourceMapFilename = argument; })
      .add_positional("INFILE", Options::Arguments::One,
                      [](Options *o, const std::string& argument) {
                        o->extra["infile"] = argument;
                      });
  options.parse(argc, argv);

  auto input(read_file<std::vector<char>>(options.extra["infile"], Flags::Binary, options.debug ? Flags::Debug : Flags::Release));

  if (options.debug) std::cerr << "parsing binary..." << std::endl;
  Module wasm;
  try {
    std::unique_ptr<std::ifstream> sourceMapStream;
    WasmBinaryBuilder parser(wasm, input, options.debug);
    if (sourceMapFilename.size()) {
        sourceMapStream = make_unique<std::ifstream>();
        sourceMapStream->open(sourceMapFilename);
        parser.setDebugLocations(sourceMapStream.get());
    }
    parser.read();
    if (sourceMapStream) {
        sourceMapStream->close();
    }
  } catch (ParseException& p) {
    p.dump(std::cerr);
    Fatal() << "error in parsing wasm binary";
  } catch (MapParseException& p) {
    p.dump(std::cerr);
    Fatal() << "error in parsing wasm source mapping";
  }

  if (options.debug) std::cerr << "Printing..." << std::endl;
  Output output(options.extra["output"], Flags::Text, options.debug ? Flags::Debug : Flags::Release);
  WasmPrinter::printModule(&wasm, output.getStream());
  output << '\n';

  if (options.debug) std::cerr << "Done." << std::endl;
}