v8-formula.py

import sys
import re
import base64
import hashlib

from jinja2 import Environment
from urllib2 import urlopen
from threading import Thread


def getV8TarballSha256(v8_tag, v8_sha256):
    sha256 = hashlib.sha256()
    sha256.update(urlopen("https://github.com/v8/v8/archive/{}.tar.gz".format(v8_tag)).read())
    v8_sha256[0] = sha256.hexdigest()


def main():
    # get latest stable v8_tag from omahaproxy
    omahaproxy = urlopen("https://omahaproxy.appspot.com/all?os=mac&channel=stable").read()
    v8_tag = re.search("mac,stable,.*,(.*)", omahaproxy).group(1)

    # calculate tarball sha256 in another thread, becausing doenloading it takes the longest time
    v8_sha256 = ['']
    sha_thread = Thread(target=getV8TarballSha256, args=(v8_tag, v8_sha256))
    sha_thread.start()

    # read main DEPS file from v8 github repo via raw.githubusercontent.com
    V8_DEPS = urlopen("https://raw.githubusercontent.com/v8/v8/{}/DEPS".format(v8_tag)).read()
    dep_locals = {'Var': lambda x: dep_locals['vars'][x], 'False': False, 'True': True}
    exec(V8_DEPS, {"__builtins__": None}, dep_locals)

    # throw if recursedeps array in main DEPS file changed
    # TODO: handle recursedeps properly
    if dep_locals['recursedeps'] != ['v8/buildtools', 'v8/third_party/android_tools']:
        raise Exception("incompatible recuredeps array found")

    # parse deps from main DEPS file
    deps = {}
    for d, r in dep_locals['deps'].items():
        # blacklisting target os here instead of whitelisting checkout_mac, TODO: handle target cpu conditions?
        if isinstance(r, dict):
            if r['condition'] in ['checkout_android', 'checkout_chromeos',
                                  'checkout_fuchsia', 'checkout_ios', 'checkout_linux', 'checkout_win']:
                continue
            r = r['url']
        repo = re.search("(.*)@(.*)", r)
        deps[d] = {'path': d, 'url': repo.group(1), 'rev': repo.group(2)}

    # parse hooks from main DEPS file
    hooks = []
    for h in dep_locals['hooks']:
        if 'condition' in h:
            c_locals = {
                'host_os': 'mac',
                'build_for_node': False,
                'checkout_android': False,
                'checkout_fuchsia': False,
                'checkout_win': False,
                'checkout_linux': False,
                'False': False,
                'True': True}
            c_locals.update(dep_locals['vars'])
            exec('condition_result = ' + h['condition'], {"__builtins__": None}, c_locals)
            if not c_locals['condition_result']:
                continue
        hooks.append('system "' + '", "'.join(h['action']) + '"')

    # read recursive DEPS file for buildtools from chromium.googlesource.com (base64 encoded)
    BT_DEPS = base64.standard_b64decode(urlopen(
        "https://chromium.googlesource.com/chromium/buildtools.git/+/{}/DEPS?format=TEXT".format(deps['v8/buildtools']['rev'])).read())
    bt_dep_locals = {'Var': lambda x: bt_dep_locals['vars'][x], 'False': False, 'True': True}
    exec(BT_DEPS, {"__builtins__": None}, bt_dep_locals)

    # parse deps from buildtools recursice DEPS file
    for d, r in bt_dep_locals['deps'].items():
        if isinstance(r, dict):  # shouldn't be needed here, just in case they use it in the future
            if r['condition'] in ['checkout_android', 'checkout_chromeos',
                                  'checkout_fuchsia', 'checkout_ios', 'checkout_linux', 'checkout_win']:
                continue
            r = r['url']
        repo = re.search("(.*)@(.*)", r)
        deps[d] = {'path': d, 'url': repo.group(1), 'rev': repo.group(2)}

    env = Environment(trim_blocks=True)

    FORMULA_TEMPLATE = env.from_string("""\
class V8 < Formula
  desc "Google's JavaScript engine"
  homepage "https://github.com/v8/v8/wiki"
  url "https://github.com/v8/v8/archive/{{ v8_tag }}.tar.gz"
  sha256 "{{  v8_sha256  }}"

  bottle do
    cellar :any
    sha256 "179a8442510eb0a022ea6823cd6a76044c14c4fe18415710cac3d746d432020e" => :high_sierra
    sha256 "8106efc14371982af11a66d8db533dc0589bc240950e0e445467cf6ce8871393" => :sierra
    sha256 "487f2ca72096ee27d13533a6dad2d472a92ba40ef518a45226f19e94d4a79242" => :el_capitan
    sha256 "dc9af3e08eda8a4acd1ff3c6b47a4c5170a92dbab7d2d79958a14d8aa42eefac" => :yosemite
    sha256 "7bcd1bbd66c11305eeea0c36ca472de8a639f511abe0909c8815b1208dbce7b6" => :mavericks
  end

  # https://bugs.chromium.org/p/chromium/issues/detail?id=620127
  depends_on :macos => :el_capitan

  # depot_tools/GN require Python 2.7+
  depends_on "python@2" => :build

  needs :cxx11
{%   for d in deps.values() %}
{%   include ResourceTemplate %}
{%   endfor %}

  def install
    (buildpath/"v8").install Dir.glob("*", File::FNM_DOTMATCH) - %w[. .. .brew_home]

    # autogenerated installing resources to paths according to DEPS file
{%   for d in deps.values() %}
    (buildpath/"{{ d.path }}").install resource("{{ d.path }}")
{%   endfor %}

    # add depot_tools to PATH (for download_from_google_storage tool)
    ENV.prepend_path "PATH", buildpath/"v8/third_party/depot_tools"

    # autogenerated system calls for hooks in DEPS file
{%   for h in hooks %}
    {{ h }}
{%   endfor %}

    cd "v8" do
      output_path = "out.gn/x64.release"

      gn_args = {
        :is_debug => false,
        :is_component_build => true,
        :v8_use_external_startup_data => false,
        :v8_enable_i18n_support => true,
      }

      # Transform to args string
      gn_args_string = gn_args.map { |k, v| "#{k}=#{v}" }.join(" ")

      # Build with gn + ninja
      system "gn",
        "gen",
        "--args=#{gn_args_string}",
        output_path

      system "ninja",
        "-j", ENV.make_jobs,
        "-C", output_path,
        "-v",
        "d8"

      # Install all the things
      include.install Dir["include/*"]

      cd output_path do
        lib.install Dir["lib*.dylib"]

        # Install d8 and icudtl.dat in libexec and symlink
        # because they need to be in the same directory.
        libexec.install Dir["d8", "icudt*.dat"]
        (bin/"d8").write <<~EOS
          #!/bin/bash
          exec "#{libexec}/d8" --icu-data-file="#{libexec}/icudtl.dat" "$@"
        EOS
      end
    end
  end

  test do
    assert_equal "Hello World!", shell_output("#{bin}/d8 -e 'print(\\"Hello World!\\");'").chomp
    assert_match %r{12/\\d{2}/2012}, shell_output("#{bin}/d8 -e 'print(new Intl.DateTimeFormat(\\"en-US\\").format(new Date(Date.UTC(2012, 11, 20, 3, 0, 0))));'").chomp
  end
end
""")

    RESOURCE_TEMPLATE = env.from_string("""\

  resource "{{ d.path }}" do
    url "{{ d.url }}",
      :revision => "{{ d.rev }}"
  end

""")

    sha_thread.join()  # waiting for v8 tarball hasher thread
    formula = FORMULA_TEMPLATE.render(
        v8_tag=v8_tag,
        v8_sha256=v8_sha256[0],
        deps=deps,
        hooks=hooks,
        ResourceTemplate=RESOURCE_TEMPLATE)
    print(formula)
    return 0


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