Function acorn_optimizer

tools/building.py:395–433

(filename, passes, extra_info=None, return_output=False, worker_js=False)

# run JS optimizer on some JS, ignoring asm.js contents if any - just run on it all
def acorn_optimizer(filename, passes, extra_info=None, return_output=False, worker_js=False):
  optimizer = path_from_root('tools/acorn-optimizer.mjs')
  original_filename = filename
  if extra_info is not None and not shared.SKIP_SUBPROCS:
    temp_files = shared.get_temp_files()
    temp = temp_files.get('.js', prefix='emcc_acorn_info_').name
    shutil.copyfile(filename, temp)
    with open(temp, 'a', encoding='utf-8') as f:
      f.write('// EXTRA_INFO: ' + json.dumps(extra_info))
    filename = temp
  cmd = [*config.NODE_JS, optimizer, filename, *passes]
  if not worker_js:
    # Keep JS code comments intact through the acorn optimization pass so that
    # JSDoc comments will be carried over to a later Closure run.
    if settings.MAYBE_CLOSURE_COMPILER:
      cmd += ['--closure-friendly']
    if settings.EXPORT_ES6:
      cmd += ['--export-es6']
  if settings.VERBOSE:
    cmd += ['--verbose']
  if return_output:
    if shared.SKIP_SUBPROCS:
      shared.print_compiler_stage(cmd)
      return ''
    return check_call(cmd, stdout=PIPE).stdout

  acorn_optimizer.counter += 1
  basename = utils.unsuffixed(original_filename)
  if '.jso' in basename:
    basename = utils.unsuffixed(basename)
  output_file = basename + '.jso%d.js' % acorn_optimizer.counter
  shared.get_temp_files().note(output_file)
  cmd += ['-o', output_file]
  if shared.SKIP_SUBPROCS:
    shared.print_compiler_stage(cmd)
    return output_file
  check_call(cmd)
  save_intermediate(output_file, '%s.js' % passes[0])
  return output_file


acorn_optimizer.counter = 0  # type: ignore