scripts/deps/download_emscripten.py

#!/usr/bin/env python3
#
# Copyright 2020 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.
"""
Used to download a pre-built version of emscripten for running e2e tests
testing DevTools with emscripten generated Wasm binaries.
"""

import argparse
import os
import platform
import shutil
import sys
import tarfile
import urllib.request
import zipfile

BS = 8192
STAMP_FILE = 'build-revision'
DOWNLOAD_URL = "https://storage.googleapis.com/webassembly/emscripten-releases-builds/%s/%s/wasm-binaries%s.%s"


# Returns None when files was not found
# Return boolean if file found depending on version is the same
def check_stamp_file(options, url):
    file_name = os.path.join(options.dest, STAMP_FILE)
    if not os.path.isfile(file_name):
        return None
    with open(file_name) as f:
        return url == f.read().strip()


def write_stamp_file(options, url):
    with open(os.path.join(options.dest, STAMP_FILE), 'w') as f:
        return f.write(url)


def unzip(os_name, file, dest):
    is_zip = os_name == 'win'
    z = zipfile.ZipFile(file) if is_zip else tarfile.open(file, 'r:bz2')
    z.extractall(path=dest)


def script_main(args):
    parser = argparse.ArgumentParser(description='Download Emscripten')
    parser.add_argument('tag', help='emscripten tag')
    parser.add_argument('dest', help='destination directory')
    options = parser.parse_args(args)

    if not os.path.isdir(options.dest):
        os.makedirs(options.dest)

    os_name = {
        'Linux': 'linux',
        'Windows': 'win',
        'Darwin': 'mac'
    }[platform.system()]

    arch_suffix = ''
    host_arch = platform.machine().lower()
    if host_arch == 'arm64' or host_arch.startswith('aarch64'):
        arch_suffix = '-arm64'

    file_extension = 'zip' if os_name == 'win' else 'tbz2'

    url = DOWNLOAD_URL % (os_name, options.tag, arch_suffix, file_extension)

    build_revision_same = check_stamp_file(options, url)
    if build_revision_same:
        return 0
    elif build_revision_same is False:
        try:
            shutil.rmtree(os.path.join(options.dest, 'install'))
        except Exception as e:
            sys.stderr.write('Error while remove old version: {e}'.format(e=e))

    try:
        filename, _ = urllib.request.urlretrieve(url)

        unzip(os_name, filename, options.dest)

        write_stamp_file(options, url)
    except Exception as e:
        sys.stderr.write('Error Downloading URL "{url}": {e}\n'.format(url=url,
                                                                       e=e))
        return 1
    finally:
        urllib.request.urlcleanup()


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