text: #!/usr/bin/env python3
  # Copyright 2018 The Chromium Authors. All rights reserved.
  # Use of this source code is governed by a BSD-style license that can be
  # found in the LICENSE file.
  """Generate linker version scripts for Chrome on Android shared libraries."""
  
  import argparse
  import os
  
  from util import build_utils
  
  _SCRIPT_HEADER = """\
  # AUTO-GENERATED FILE.  DO NOT MODIFY.
  #
  # See: %s
  
  {
    global:
  """ % os.path.relpath(__file__, build_utils.DIR_SOURCE_ROOT)
  
  _SCRIPT_FOOTER = """\
    local:
      *;
  };
  """
  
  
  def main():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        '--output',
        required=True,
        help='Path to output linker version script file.')
    parser.add_argument(
        '--export-java-symbols',
        action='store_true',
        help='Export Java_* JNI methods')
    parser.add_argument(
        '--export-symbol-allowlist-file',
        action='append',
        default=[],
        dest='allowlists',
        help='Path to an input file containing an allowlist of extra symbols to '
        'export, one symbol per line. Multiple files may be specified.')
    parser.add_argument(
        '--export-feature-registrations',
        action='store_true',
        help='Export JNI_OnLoad_* methods')
    options = parser.parse_args()
  
    # JNI_OnLoad is always exported.
    # CrashpadHandlerMain() is the entry point to the Crashpad handler, required
    # for libcrashpad_handler_trampoline.so.
    symbol_list = ['CrashpadHandlerMain', 'JNI_OnLoad']
  
    if options.export_java_symbols:
      symbol_list.append('Java_*')
  
    if options.export_feature_registrations:
      symbol_list.append('JNI_OnLoad_*')
  
    for allowlist in options.allowlists:
      with open(allowlist, 'rt') as f:
        for line in f:
          line = line.strip()
          if not line or line[0] == '#':
            continue
          symbol_list.append(line)
  
    script_content = [_SCRIPT_HEADER]
    for symbol in symbol_list:
      script_content.append('    %s;\n' % symbol)
    script_content.append(_SCRIPT_FOOTER)
  
    script = ''.join(script_content)
  
    with build_utils.AtomicOutput(options.output, mode='w') as f:
      f.write(script)
  
  
  if __name__ == '__main__':
    main()
  