naiveproxy/tools/gn/bootstrap/bootstrap.py

#!/usr/bin/env python
# Copyright 2014 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.

# This file isn't officially supported by the Chromium project. It's maintained
# on a best-effort basis by volunteers, so some things may be broken from time
# to time. If you encounter errors, it's most often due to files in base that
# have been added or moved since somebody last tried this script. Generally
# such errors are easy to diagnose.

"""Bootstraps gn.

It is done by first building it manually in a temporary directory, then building
it with its own BUILD.gn to the final destination.
"""

import contextlib
import errno
import logging
import optparse
import os
import platform
import shutil
import subprocess
import sys
import tempfile

BOOTSTRAP_DIR = os.path.dirname(os.path.abspath(__file__))
GN_ROOT = os.path.dirname(BOOTSTRAP_DIR)
SRC_ROOT = os.path.dirname(os.path.dirname(GN_ROOT))

is_win = sys.platform.startswith('win')
is_linux = sys.platform.startswith('linux')
is_mac = sys.platform.startswith('darwin')
is_aix = sys.platform.startswith('aix')
is_posix = is_linux or is_mac or is_aix

def check_call(cmd, **kwargs):
  logging.debug('Running: %s', ' '.join(cmd))

  # With shell=False, subprocess expects an executable on Windows
  if is_win and cmd and cmd[0].endswith('.py'):
    cmd.insert(0, sys.executable)

  subprocess.check_call(cmd, cwd=GN_ROOT, **kwargs)

def mkdir_p(path):
  try:
    os.makedirs(path)
  except OSError as e:
    if e.errno == errno.EEXIST and os.path.isdir(path):
      pass
    else: raise

@contextlib.contextmanager
def scoped_tempdir():
  path = tempfile.mkdtemp()
  try:
    yield path
  finally:
    shutil.rmtree(path)


def run_build(tempdir, options):
  if options.build_path:
    build_rel = options.build_path
  elif options.debug:
    build_rel = os.path.join('out', 'Debug')
  else:
    build_rel = os.path.join('out', 'Release')
  build_root = os.path.join(SRC_ROOT, build_rel)

  print 'Building gn manually in a temporary directory for bootstrapping...'
  build_gn_with_ninja_manually(tempdir, options)
  temp_gn = os.path.join(tempdir, 'gn')
  out_gn = os.path.join(build_root, 'gn')

  if is_win:
    temp_gn += '.exe'
    out_gn += '.exe'

  if options.no_rebuild:
    mkdir_p(build_root)
    shutil.copy2(temp_gn, out_gn)
  else:
    print 'Building gn using itself to %s...' % build_rel
    build_gn_with_gn(temp_gn, build_root, options)

  if options.output:
    # Preserve the executable permission bit.
    shutil.copy2(out_gn, options.output)

def windows_target_build_arch():
    # Target build architecture set by vcvarsall.bat
    target_arch = os.environ.get('Platform')
    if target_arch in ['x64', 'x86']: return target_arch

    if platform.machine().lower() in ['x86_64', 'amd64']: return 'x64'
    return 'x86'

def main(argv):
  parser = optparse.OptionParser(description=sys.modules[__name__].__doc__)
  parser.add_option('-d', '--debug', action='store_true',
                    help='Do a debug build. Defaults to release build.')
  parser.add_option('-o', '--output',
                    help='place output in PATH', metavar='PATH')
  parser.add_option('-s', '--no-rebuild', action='store_true',
                    help='Do not rebuild GN with GN.')
  parser.add_option('--no-clean', action='store_true',
                    help='Re-used build directory instead of using new '
                         'temporary location each time')
  parser.add_option('--gn-gen-args', help='Args to pass to gn gen --args')
  parser.add_option('--build-path', help='The directory in which to build gn, '
                    'relative to the src directory. (eg. out/Release)')
  parser.add_option('-v', '--verbose', action='store_true',
                    help='Log more details')
  options, args = parser.parse_args(argv)

  if args:
    parser.error('Unrecognized command line arguments: %s.' % ', '.join(args))

  logging.basicConfig(level=logging.DEBUG if options.verbose else logging.ERROR)

  try:
    if options.no_clean:
      build_dir = os.path.join(SRC_ROOT, 'out_bootstrap')
      if not os.path.exists(build_dir):
        os.makedirs(build_dir)
      return run_build(build_dir, options)
    else:
      with scoped_tempdir() as tempdir:
        return run_build(tempdir, options)
  except subprocess.CalledProcessError as e:
    print >> sys.stderr, str(e)
    return 1
  return 0

def write_compiled_message(root_gen_dir, source):
  path = os.path.join(root_gen_dir, os.path.dirname(source))
  mkdir_p(path)
  check_call([
      'mc.exe',
      '-r', path, '-h', path,
      '-u', '-um',
      os.path.join(SRC_ROOT, source),
  ])

def write_buildflag_header_manually(root_gen_dir, header, flags):
  mkdir_p(os.path.join(root_gen_dir, os.path.dirname(header)))

  # Don't use tempfile.NamedTemporaryFile() here.
  # It doesn't work correctly on Windows.
  # see: http://bugs.python.org/issue14243
  temp_path = os.path.join(root_gen_dir, header + '.tmp')
  with open(temp_path, 'w') as f:
    f.write('--flags')
    for name,value in flags.items():
      f.write(' ' + name + '=' + value)

  check_call([
      os.path.join(SRC_ROOT, 'build', 'write_buildflag_header.py'),
      '--output', header,
      '--gen-dir', root_gen_dir,
      '--definitions', temp_path,
  ])

  os.remove(temp_path)

def write_build_date_header(root_gen_dir):
  check_call([
       os.path.join(SRC_ROOT, 'build', 'write_build_date_header.py'),
       os.path.join(root_gen_dir, 'base/generated_build_date.h'),
       'default',
  ])

def build_gn_with_ninja_manually(tempdir, options):
  root_gen_dir = os.path.join(tempdir, 'gen')
  mkdir_p(root_gen_dir)

  write_buildflag_header_manually(root_gen_dir, 'base/allocator/features.h',
      {'USE_ALLOCATOR_SHIM': 'true' if is_linux else 'false'})

  write_buildflag_header_manually(root_gen_dir, 'base/debug/debugging_flags.h',
      {
          'ENABLE_LOCATION_SOURCE': 'false',
          'ENABLE_PROFILING': 'false',
          'CAN_UNWIND_WITH_FRAME_POINTERS': 'false',
          'UNSAFE_DEVELOPER_BUILD': 'false'
      })

  write_buildflag_header_manually(root_gen_dir, 'base/cfi_flags.h',
      {
          'CFI_CAST_CHECK': 'false',
          'CFI_ICALL_CHECK': 'false',
          'CFI_ENFORCEMENT_TRAP': 'false',
          'CFI_ENFORCEMENT_DIAGNOSTIC': 'false'
      })

  write_build_date_header(root_gen_dir)

  if is_mac:
    # //base/build_time.cc needs base/generated_build_date.h,
    # and this file is only included for Mac builds.
    mkdir_p(os.path.join(root_gen_dir, 'base'))
    check_call([
        os.path.join(SRC_ROOT, 'build', 'write_build_date_header.py'),
        os.path.join(root_gen_dir, 'base', 'generated_build_date.h'),
        'default'
    ])

  if is_win:
    write_buildflag_header_manually(root_gen_dir, 'base/win/base_features.h',
        {'SINGLE_MODULE_MODE_HANDLE_VERIFIER': 'true'})

    write_compiled_message(root_gen_dir,
        'base/trace_event/etw_manifest/chrome_events_win.man')

  write_gn_ninja(os.path.join(tempdir, 'build.ninja'),
                 root_gen_dir, options)
  cmd = ['ninja', '-C', tempdir, '-w', 'dupbuild=err']
  if options.verbose:
    cmd.append('-v')

  if is_win:
    cmd.append('gn.exe')
  else:
    cmd.append('gn')

  check_call(cmd)

def write_generic_ninja(path, static_libraries, executables,
                        cc, cxx, ar, ld,
                        cflags=[], cflags_cc=[], ldflags=[],
                        include_dirs=[], solibs=[]):
  ninja_header_lines = [
    'cc = ' + cc,
    'cxx = ' + cxx,
    'ar = ' + ar,
    'ld = ' + ld,
    '',
  ]

  if is_win:
    template_filename = 'build_vs.ninja.template'
  elif is_mac:
    template_filename = 'build_mac.ninja.template'
  elif is_aix:
    template_filename = 'build_aix.ninja.template'
  else:
    template_filename = 'build.ninja.template'

  with open(os.path.join(GN_ROOT, 'bootstrap', template_filename)) as f:
    ninja_template = f.read()

  if is_win:
    executable_ext = '.exe'
    library_ext = '.lib'
    object_ext = '.obj'
  else:
    executable_ext = ''
    library_ext = '.a'
    object_ext = '.o'

  def escape_path_ninja(path):
      return path.replace('$ ', '$$ ').replace(' ', '$ ').replace(':', '$:')

  def src_to_obj(path):
    return escape_path_ninja('%s' % os.path.splitext(path)[0] + object_ext)

  def library_to_a(library):
    return '%s%s' % (library, library_ext)

  ninja_lines = []
  def build_source(src_file, settings):
    ninja_lines.extend([
        'build %s: %s %s' % (src_to_obj(src_file),
                             settings['tool'],
                             escape_path_ninja(
                                 os.path.join(SRC_ROOT, src_file))),
        '  includes = %s' % ' '.join(
            ['-I' + escape_path_ninja(dirname) for dirname in
             include_dirs + settings.get('include_dirs', [])]),
        '  cflags = %s' % ' '.join(cflags + settings.get('cflags', [])),
        '  cflags_cc = %s' %
            ' '.join(cflags_cc + settings.get('cflags_cc', [])),
    ])

  for library, settings in static_libraries.iteritems():
    for src_file in settings['sources']:
      build_source(src_file, settings)

    ninja_lines.append('build %s: alink_thin %s' % (
        library_to_a(library),
        ' '.join([src_to_obj(src_file) for src_file in settings['sources']])))

  for executable, settings in executables.iteritems():
    for src_file in settings['sources']:
      build_source(src_file, settings)

    ninja_lines.extend([
      'build %s%s: link %s | %s' % (
          executable, executable_ext,
          ' '.join([src_to_obj(src_file) for src_file in settings['sources']]),
          ' '.join([library_to_a(library) for library in settings['libs']])),
      '  ldflags = %s' % ' '.join(ldflags),
      '  solibs = %s' % ' '.join(solibs),
      '  libs = %s' % ' '.join(
          [library_to_a(library) for library in settings['libs']]),
    ])

  ninja_lines.append('')  # Make sure the file ends with a newline.

  with open(path, 'w') as f:
    f.write('\n'.join(ninja_header_lines))
    f.write(ninja_template)
    f.write('\n'.join(ninja_lines))

def write_gn_ninja(path, root_gen_dir, options):
  if is_win:
    cc = os.environ.get('CC', 'cl.exe')
    cxx = os.environ.get('CXX', 'cl.exe')
    ld = os.environ.get('LD', 'link.exe')
    ar = os.environ.get('AR', 'lib.exe')
  elif is_aix:
    cc = os.environ.get('CC', 'gcc')
    cxx = os.environ.get('CXX', 'c++')
    ld = os.environ.get('LD', cxx)
    ar = os.environ.get('AR', 'ar -X64')
  else:
    cc = os.environ.get('CC', 'cc')
    cxx = os.environ.get('CXX', 'c++')
    ld = cxx
    ar = os.environ.get('AR', 'ar')

  cflags = os.environ.get('CFLAGS', '').split()
  cflags_cc = os.environ.get('CXXFLAGS', '').split()
  ldflags = os.environ.get('LDFLAGS', '').split()
  include_dirs = [root_gen_dir, SRC_ROOT]
  libs = []

  # //base/allocator/allocator_extension.cc needs this macro defined,
  # otherwise there would be link errors.
  cflags.extend(['-DNO_TCMALLOC', '-D__STDC_FORMAT_MACROS'])

  if is_posix:
    if options.debug:
      cflags.extend(['-O0', '-g'])
    else:
      # The linux::ppc64 BE binary doesn't "work" when
      # optimization level is set to 2 (0 works fine).
      # Note that the current bootstrap script has no way to detect host_cpu.
      # This can be easily fixed once we start building using a GN binary,
      # as the optimization flag can then just be set using the
      # logic inside //build/toolchain.
      cflags.extend(['-O2', '-g0'])

    cflags.extend([
        '-D_FILE_OFFSET_BITS=64',
        '-D__STDC_CONSTANT_MACROS', '-D__STDC_FORMAT_MACROS',
        '-pthread',
        '-pipe',
        '-fno-exceptions'
    ])
    cflags_cc.extend(['-std=c++14', '-Wno-c++11-narrowing'])
    if is_aix:
     cflags.extend(['-maix64'])
     ldflags.extend([ '-maix64 -Wl,-bbigtoc' ])
  elif is_win:
    if not options.debug:
      cflags.extend(['/Ox', '/DNDEBUG', '/GL'])
      ldflags.extend(['/LTCG', '/OPT:REF', '/OPT:ICF'])

    cflags.extend([
        '/FS',
        '/Gy',
        '/W3', '/wd4244',
        '/Zi',
        '/DWIN32_LEAN_AND_MEAN', '/DNOMINMAX',
        '/D_CRT_SECURE_NO_DEPRECATE', '/D_SCL_SECURE_NO_DEPRECATE',
        '/D_WIN32_WINNT=0x0A00', '/DWINVER=0x0A00',
        '/DUNICODE', '/D_UNICODE',
    ])
    cflags_cc.extend([
        '/GR-',
        '/D_HAS_EXCEPTIONS=0',
    ])

    target_arch = windows_target_build_arch()
    if target_arch == 'x64':
        ldflags.extend(['/MACHINE:x64'])
    else:
        ldflags.extend(['/MACHINE:x86'])

  static_libraries = {
      'base': {'sources': [], 'tool': 'cxx', 'include_dirs': []},
      'dynamic_annotations': {'sources': [], 'tool': 'cc', 'include_dirs': []},
      'gn_lib': {'sources': [], 'tool': 'cxx', 'include_dirs': []},
  }

  executables = {
      'gn': {'sources': ['tools/gn/gn_main.cc'],
             'tool': 'cxx', 'include_dirs': [], 'libs': []},
  }

  for name in os.listdir(GN_ROOT):
    if not name.endswith('.cc'):
      continue
    if name.endswith('_unittest.cc'):
      continue
    if name == 'run_all_unittests.cc':
      continue
    if name == 'gn_main.cc':
      continue
    full_path = os.path.join(GN_ROOT, name)
    static_libraries['gn_lib']['sources'].append(
        os.path.relpath(full_path, SRC_ROOT))

  static_libraries['dynamic_annotations']['sources'].extend([
      'base/third_party/dynamic_annotations/dynamic_annotations.c',
      'base/third_party/superfasthash/superfasthash.c',
  ])
  static_libraries['base']['sources'].extend([
      'base/allocator/allocator_check.cc',
      'base/allocator/allocator_extension.cc',
      'base/at_exit.cc',
      'base/base_paths.cc',
      'base/base_switches.cc',
      'base/build_time.cc',
      'base/callback_helpers.cc',
      'base/callback_internal.cc',
      'base/command_line.cc',
      'base/debug/activity_tracker.cc',
      'base/debug/alias.cc',
      'base/debug/crash_logging.cc',
      'base/debug/dump_without_crashing.cc',
      'base/debug/stack_trace.cc',
      'base/debug/task_annotator.cc',
      'base/debug/thread_heap_usage_tracker.cc',
      'base/environment.cc',
      'base/feature_list.cc',
      'base/files/file.cc',
      'base/files/file_enumerator.cc',
      'base/files/file_path.cc',
      'base/files/file_path_constants.cc',
      'base/files/file_tracing.cc',
      'base/files/file_util.cc',
      'base/files/important_file_writer.cc',
      'base/files/memory_mapped_file.cc',
      'base/files/scoped_file.cc',
      'base/hash.cc',
      'base/json/json_parser.cc',
      'base/json/json_reader.cc',
      'base/json/json_string_value_serializer.cc',
      'base/json/json_writer.cc',
      'base/json/string_escape.cc',
      'base/lazy_instance.cc',
      'base/location.cc',
      'base/logging.cc',
      'base/md5.cc',
      'base/memory/ref_counted.cc',
      'base/memory/ref_counted_memory.cc',
      'base/memory/singleton.cc',
      'base/memory/shared_memory_handle.cc',
      'base/memory/shared_memory_tracker.cc',
      'base/memory/weak_ptr.cc',
      'base/message_loop/incoming_task_queue.cc',
      'base/message_loop/message_loop.cc',
      'base/message_loop/message_loop_task_runner.cc',
      'base/message_loop/message_pump.cc',
      'base/message_loop/message_pump_default.cc',
      'base/metrics/bucket_ranges.cc',
      'base/metrics/field_trial.cc',
      'base/metrics/field_trial_param_associator.cc',
      'base/metrics/field_trial_params.cc',
      'base/metrics/histogram.cc',
      'base/metrics/histogram_base.cc',
      'base/metrics/histogram_functions.cc',
      'base/metrics/histogram_samples.cc',
      'base/metrics/histogram_snapshot_manager.cc',
      'base/metrics/metrics_hashes.cc',
      'base/metrics/persistent_histogram_allocator.cc',
      'base/metrics/persistent_memory_allocator.cc',
      'base/metrics/persistent_sample_map.cc',
      'base/metrics/sample_map.cc',
      'base/metrics/sample_vector.cc',
      'base/metrics/sparse_histogram.cc',
      'base/metrics/statistics_recorder.cc',
      'base/observer_list_threadsafe.cc',
      'base/path_service.cc',
      'base/pending_task.cc',
      'base/pickle.cc',
      'base/process/kill.cc',
      'base/process/memory.cc',
      'base/process/process_handle.cc',
      'base/process/process_iterator.cc',
      'base/process/process_metrics.cc',
      'base/rand_util.cc',
      'base/run_loop.cc',
      'base/sequence_token.cc',
      'base/sequence_checker_impl.cc',
      'base/sequenced_task_runner.cc',
      'base/sha1.cc',
      'base/strings/pattern.cc',
      'base/strings/string_number_conversions.cc',
      'base/strings/string_piece.cc',
      'base/strings/string_split.cc',
      'base/strings/string_util.cc',
      'base/strings/string_util_constants.cc',
      'base/strings/stringprintf.cc',
      'base/strings/utf_string_conversion_utils.cc',
      'base/strings/utf_string_conversions.cc',
      'base/synchronization/atomic_flag.cc',
      'base/synchronization/lock.cc',
      'base/sys_info.cc',
      'base/task_runner.cc',
      'base/task_scheduler/delayed_task_manager.cc',
      'base/task_scheduler/environment_config.cc',
      'base/task_scheduler/post_task.cc',
      'base/task_scheduler/priority_queue.cc',
      'base/task_scheduler/scheduler_lock_impl.cc',
      'base/task_scheduler/scheduler_single_thread_task_runner_manager.cc',
      'base/task_scheduler/scheduler_worker.cc',
      'base/task_scheduler/scheduler_worker_pool.cc',
      'base/task_scheduler/scheduler_worker_pool_impl.cc',
      'base/task_scheduler/scheduler_worker_pool_params.cc',
      'base/task_scheduler/scheduler_worker_stack.cc',
      'base/task_scheduler/scoped_set_task_priority_for_current_thread.cc',
      'base/task_scheduler/sequence.cc',
      'base/task_scheduler/sequence_sort_key.cc',
      'base/task_scheduler/task.cc',
      'base/task_scheduler/task_scheduler.cc',
      'base/task_scheduler/task_scheduler_impl.cc',
      'base/task_scheduler/task_tracker.cc',
      'base/task_scheduler/task_traits.cc',
      'base/third_party/dmg_fp/dtoa_wrapper.cc',
      'base/third_party/dmg_fp/g_fmt.cc',
      'base/third_party/icu/icu_utf.cc',
      'base/third_party/nspr/prtime.cc',
      'base/threading/post_task_and_reply_impl.cc',
      'base/threading/scoped_blocking_call.cc',
      'base/threading/sequence_local_storage_map.cc',
      'base/threading/sequenced_task_runner_handle.cc',
      'base/threading/sequenced_worker_pool.cc',
      'base/threading/simple_thread.cc',
      'base/threading/thread.cc',
      'base/threading/thread_checker_impl.cc',
      'base/threading/thread_collision_warner.cc',
      'base/threading/thread_id_name_manager.cc',
      'base/threading/thread_local_storage.cc',
      'base/threading/thread_restrictions.cc',
      'base/threading/thread_task_runner_handle.cc',
      'base/time/clock.cc',
      'base/time/default_clock.cc',
      'base/time/default_tick_clock.cc',
      'base/time/tick_clock.cc',
      'base/time/time.cc',
      'base/timer/elapsed_timer.cc',
      'base/timer/timer.cc',
      'base/trace_event/category_registry.cc',
      'base/trace_event/event_name_filter.cc',
      'base/trace_event/heap_profiler_allocation_context.cc',
      'base/trace_event/heap_profiler_allocation_context_tracker.cc',
      'base/trace_event/heap_profiler_allocation_register.cc',
      'base/trace_event/heap_profiler_event_filter.cc',
      'base/trace_event/heap_profiler_heap_dump_writer.cc',
      'base/trace_event/heap_profiler_serialization_state.cc',
      'base/trace_event/heap_profiler_stack_frame_deduplicator.cc',
      'base/trace_event/heap_profiler_type_name_deduplicator.cc',
      'base/trace_event/malloc_dump_provider.cc',
      'base/trace_event/memory_allocator_dump.cc',
      'base/trace_event/memory_allocator_dump_guid.cc',
      'base/trace_event/memory_dump_manager.cc',
      'base/trace_event/memory_dump_provider_info.cc',
      'base/trace_event/memory_dump_request_args.cc',
      'base/trace_event/memory_dump_scheduler.cc',
      'base/trace_event/memory_infra_background_whitelist.cc',
      'base/trace_event/memory_peak_detector.cc',
      'base/trace_event/memory_usage_estimator.cc',
      'base/trace_event/process_memory_dump.cc',
      'base/trace_event/sharded_allocation_register.cc',
      'base/trace_event/trace_buffer.cc',
      'base/trace_event/trace_config.cc',
      'base/trace_event/trace_config_category_filter.cc',
      'base/trace_event/trace_event_argument.cc',
      'base/trace_event/trace_event_filter.cc',
      'base/trace_event/trace_event_impl.cc',
      'base/trace_event/trace_event_memory_overhead.cc',
      'base/trace_event/trace_log.cc',
      'base/trace_event/trace_log_constants.cc',
      'base/trace_event/tracing_agent.cc',
      'base/unguessable_token.cc',
      'base/value_iterators.cc',
      'base/values.cc',
      'base/vlog.cc',
  ])

  if is_posix:
    static_libraries['base']['sources'].extend([
        'base/base_paths_posix.cc',
        'base/debug/debugger_posix.cc',
        'base/debug/stack_trace_posix.cc',
        'base/files/file_enumerator_posix.cc',
        'base/files/file_descriptor_watcher_posix.cc',
        'base/files/file_posix.cc',
        'base/files/file_util_posix.cc',
        'base/files/memory_mapped_file_posix.cc',
        'base/memory/shared_memory_helper.cc',
        'base/message_loop/message_pump_libevent.cc',
        'base/posix/file_descriptor_shuffle.cc',
        'base/posix/global_descriptors.cc',
        'base/posix/safe_strerror.cc',
        'base/process/kill_posix.cc',
        'base/process/process_handle_posix.cc',
        'base/process/process_metrics_posix.cc',
        'base/process/process_posix.cc',
        'base/rand_util_posix.cc',
        'base/strings/string16.cc',
        'base/synchronization/condition_variable_posix.cc',
        'base/synchronization/lock_impl_posix.cc',
        'base/sys_info_posix.cc',
        'base/task_scheduler/task_tracker_posix.cc',
        'base/threading/platform_thread_internal_posix.cc',
        'base/threading/platform_thread_posix.cc',
        'base/threading/thread_local_storage_posix.cc',
        'base/time/time_conversion_posix.cc',
        'base/trace_event/heap_profiler_allocation_register_posix.cc',
    ])
  if not is_linux:
    static_libraries['libevent'] = {
        'sources': [
            'base/third_party/libevent/buffer.c',
            'base/third_party/libevent/evbuffer.c',
            'base/third_party/libevent/event.c',
            'base/third_party/libevent/evutil.c',
            'base/third_party/libevent/log.c',
            'base/third_party/libevent/poll.c',
            'base/third_party/libevent/select.c',
            'base/third_party/libevent/signal.c',
            'base/third_party/libevent/strlcpy.c',
        ],
        'tool': 'cc',
        'include_dirs': [],
        'cflags': cflags + ['-DHAVE_CONFIG_H'],
    }

  if is_linux or is_aix:
    ldflags.extend(['-pthread'])

    static_libraries['xdg_user_dirs'] = {
        'sources': [
            'base/third_party/xdg_user_dirs/xdg_user_dir_lookup.cc',
        ],
        'tool': 'cxx',
    }
    static_libraries['base']['sources'].extend([
        'base/memory/shared_memory_handle_posix.cc',
        'base/memory/shared_memory_posix.cc',
        'base/nix/xdg_util.cc',
        'base/process/internal_linux.cc',
        'base/process/memory_linux.cc',
        'base/process/process_handle_linux.cc',
        'base/process/process_info_linux.cc',
        'base/process/process_iterator_linux.cc',
        'base/process/process_linux.cc',
        'base/process/process_metrics_linux.cc',
        'base/strings/sys_string_conversions_posix.cc',
        'base/synchronization/waitable_event_posix.cc',
        'base/sys_info_linux.cc',
        'base/time/time_exploded_posix.cc',
        'base/time/time_now_posix.cc',
        'base/threading/platform_thread_linux.cc',
    ])
    if is_linux:
      static_libraries['base']['sources'].extend([
        'base/allocator/allocator_shim.cc',
        'base/allocator/allocator_shim_default_dispatch_to_glibc.cc',
      ])
      libs.extend(['-lrt', '-latomic', '-levent_core'])
    else:
      libs.extend(['-lrt'])
      static_libraries['base']['sources'].extend([
          'base/process/internal_aix.cc'
      ])
      static_libraries['libevent']['include_dirs'].extend([
          os.path.join(SRC_ROOT, 'base', 'third_party', 'libevent', 'aix')
      ])
      static_libraries['libevent']['include_dirs'].extend([
          os.path.join(SRC_ROOT, 'base', 'third_party', 'libevent', 'compat')
      ])

  if is_mac:
    static_libraries['base']['sources'].extend([
        'base/base_paths_mac.mm',
        'base/files/file_util_mac.mm',
        'base/mac/bundle_locations.mm',
        'base/mac/call_with_eh_frame.cc',
        'base/mac/call_with_eh_frame_asm.S',
        'base/mac/foundation_util.mm',
        'base/mac/mach_logging.cc',
        'base/mac/scoped_mach_port.cc',
        'base/mac/scoped_mach_vm.cc',
        'base/mac/scoped_nsautorelease_pool.mm',
        'base/memory/shared_memory_handle_mac.cc',
        'base/memory/shared_memory_mac.cc',
        'base/message_loop/message_pump_mac.mm',
        'base/process/process_handle_mac.cc',
        'base/process/process_info_mac.cc',
        'base/process/process_iterator_mac.cc',
        'base/process/process_metrics_mac.cc',
        'base/strings/sys_string_conversions_mac.mm',
        'base/synchronization/waitable_event_mac.cc',
        'base/sys_info_mac.mm',
        'base/time/time_mac.cc',
        'base/threading/platform_thread_mac.mm',
    ])
    static_libraries['libevent']['include_dirs'].extend([
        os.path.join(SRC_ROOT, 'base', 'third_party', 'libevent', 'mac')
    ])
    static_libraries['libevent']['sources'].extend([
        'base/third_party/libevent/kqueue.c',
    ])

    libs.extend([
        '-framework', 'AppKit',
        '-framework', 'CoreFoundation',
        '-framework', 'Foundation',
        '-framework', 'Security',
    ])

  if is_win:
    static_libraries['base']['sources'].extend([
        'base/base_paths_win.cc',
        'base/cpu.cc',
        'base/debug/close_handle_hook_win.cc',
        'base/debug/debugger.cc',
        'base/debug/debugger_win.cc',
        'base/debug/profiler.cc',
        'base/debug/stack_trace_win.cc',
        'base/file_version_info_win.cc',
        'base/files/file_enumerator_win.cc',
        'base/files/file_path_watcher_win.cc',
        'base/files/file_util_win.cc',
        'base/files/file_win.cc',
        'base/files/memory_mapped_file_win.cc',
        'base/guid.cc',
        'base/logging_win.cc',
        'base/memory/memory_pressure_monitor_win.cc',
        'base/memory/shared_memory_handle_win.cc',
        'base/memory/shared_memory_win.cc',
        'base/message_loop/message_pump_win.cc',
        'base/native_library_win.cc',
        'base/power_monitor/power_monitor_device_source_win.cc',
        'base/process/kill_win.cc',
        'base/process/launch_win.cc',
        'base/process/memory_win.cc',
        'base/process/process_handle_win.cc',
        'base/process/process_info_win.cc',
        'base/process/process_iterator_win.cc',
        'base/process/process_metrics_win.cc',
        'base/process/process_win.cc',
        'base/profiler/native_stack_sampler_win.cc',
        'base/profiler/win32_stack_frame_unwinder.cc',
        'base/rand_util_win.cc',
        'base/strings/sys_string_conversions_win.cc',
        'base/sync_socket_win.cc',
        'base/synchronization/condition_variable_win.cc',
        'base/synchronization/lock_impl_win.cc',
        'base/synchronization/read_write_lock_win.cc',
        'base/synchronization/waitable_event_watcher_win.cc',
        'base/synchronization/waitable_event_win.cc',
        'base/sys_info_win.cc',
        'base/threading/platform_thread_win.cc',
        'base/threading/thread_local_storage_win.cc',
        'base/threading/worker_pool_win.cc',
        'base/time/time_win.cc',
        'base/timer/hi_res_timer_manager_win.cc',
        'base/trace_event/heap_profiler_allocation_register_win.cc',
        'base/trace_event/trace_event_etw_export_win.cc',
        'base/win/enum_variant.cc',
        'base/win/event_trace_controller.cc',
        'base/win/event_trace_provider.cc',
        'base/win/i18n.cc',
        'base/win/iat_patch_function.cc',
        'base/win/iunknown_impl.cc',
        'base/win/message_window.cc',
        'base/win/object_watcher.cc',
        'base/win/pe_image.cc',
        'base/win/process_startup_helper.cc',
        'base/win/registry.cc',
        'base/win/resource_util.cc',
        'base/win/scoped_bstr.cc',
        'base/win/scoped_handle.cc',
        'base/win/scoped_process_information.cc',
        'base/win/scoped_variant.cc',
        'base/win/shortcut.cc',
        'base/win/startup_information.cc',
        'base/win/wait_chain.cc',
        'base/win/win_util.cc',
        'base/win/windows_version.cc',
        'base/win/wrapped_window_proc.cc',
    ])

    libs.extend([
        'advapi32.lib',
        'dbghelp.lib',
        'kernel32.lib',
        'ole32.lib',
        'shell32.lib',
        'user32.lib',
        'userenv.lib',
        'version.lib',
        'winmm.lib',
        'ws2_32.lib',
        'Shlwapi.lib',
    ])

  # we just build static libraries that GN needs
  executables['gn']['libs'].extend(static_libraries.keys())

  write_generic_ninja(path, static_libraries, executables, cc, cxx, ar, ld,
                      cflags, cflags_cc, ldflags, include_dirs, libs)

def build_gn_with_gn(temp_gn, build_dir, options):
  gn_gen_args = options.gn_gen_args or ''
  if not options.debug:
    gn_gen_args += ' is_debug=false'
  cmd = [temp_gn, 'gen', build_dir, '--args=%s' % gn_gen_args]
  check_call(cmd)

  cmd = ['ninja', '-C', build_dir, '-w', 'dupbuild=err']
  if options.verbose:
    cmd.append('-v')
  cmd.append('gn')
  check_call(cmd)

  if not options.debug and not is_win:
    check_call(['strip', os.path.join(build_dir, 'gn')])


if __name__ == '__main__':
  sys.exit(main(sys.argv[1:]))