recipes/goma_toolchain.resources/preprocess_gcc.py

#!/usr/bin/env python
# Copyright 2020 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Minimize Fuchsia GCC toolchains.
Usage:
  python preprocess_gcc.py --src=SRC_PATH --dst=DST_PATH --platforms=linux_amd64 --platforms=mac_amd64
"""

import argparse
import os
import sys
import shutil

GCC_TARGETS = ('aarch64-elf', 'x86_64-elf')


def preprocess_gcc(src_dir, dst_dir):
  versions = set()
  for target in GCC_TARGETS:
    versions |= set(os.listdir(os.path.join(src_dir, 'lib', 'gcc', target)))
  [gcc_version] = versions

  prefixes = set()

  def prefix_match(file):
    return any(
        os.path.commonprefix([file, prefix]) == prefix for prefix in prefixes)

  files = set([os.path.join('share', 'man', 'man7', 'gpl.7')])
  for target in GCC_TARGETS:
    files |= set([
        os.path.join('bin', target + '-gcc'),
        os.path.join('bin', target + '-g++'),
        os.path.join(target, 'bin', 'as'),
        os.path.join('libexec', 'gcc', target, gcc_version, 'cc1'),
        os.path.join('libexec', 'gcc', target, gcc_version, 'cc1plus'),
    ])
    prefixes |= set(
        os.path.join('lib', 'gcc', target, gcc_version, dir) + os.sep
        for dir in ('include', 'include-fixed'))

  def dirs_of(filelist):
    return set(os.path.dirname(file) for file in filelist)

  dirs = dirs_of(files | prefixes)
  while True:
    more_dirs = dirs_of(dirs)
    if more_dirs <= dirs:
      break
    dirs |= more_dirs

  def ignore_unnecessary(dir, contents):
    dir = os.path.relpath(dir, src_dir)

    def want(name):
      file = os.path.normpath(os.path.join(dir, name))
      return file in files or file in dirs or prefix_match(file)

    return [name for name in contents if not want(name)]

  shutil.copytree(src_dir, dst_dir, symlinks=True, ignore=ignore_unnecessary)


def main():
  parser = argparse.ArgumentParser()
  parser.add_argument('src', help='source toolchain path')
  parser.add_argument('dst', help='target toolchain path')
  parser.add_argument(
      '--platform', action='append', help='target platform name')
  args = parser.parse_args()
  for platform in args.platform:
    preprocess_gcc(
        os.path.join(args.src, platform), os.path.join(args.dst, platform))
  return 0


if __name__ == '__main__':
  sys.exit(main())