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())