old_contents: """ Helpers to download a recent clang release."""
  
  def _get_platform_folder(os_name):
      os_name = os_name.lower()
      if os_name.startswith("windows"):
          return "Win"
      if os_name.startswith("mac os"):
          return "Mac"
      if not os_name.startswith("linux"):
          fail("Unknown platform")
      return "Linux_x64"
  
  def _download_chromium_clang(
          repo_ctx,
          platform_folder,
          package_version,
          sha256,
          out_folder):
      cds_url = "https://commondatastorage.googleapis.com/chromium-browser-clang"
      cds_file = "clang-%s.tgz" % package_version
      cds_full_url = "{0}/{1}/{2}".format(cds_url, platform_folder, cds_file)
      repo_ctx.download_and_extract(cds_full_url, output = out_folder, sha256 = sha256)
  
  def download_clang(repo_ctx, out_folder):
      """ Download a fresh clang release and put it into out_folder.
  
      Clang itself will be located in 'out_folder/bin/clang'.
      We currently download one of the latest releases of clang by the
      Chromium project (see
      https://chromium.googlesource.com/chromium/src/+/master/docs/clang.md).
  
      Args:
        repo_ctx: An instance of repository_context object.
        out_folder: A folder to extract the compiler into.
      """
      # TODO(ibiryukov): we currently download and extract some extra tools in the
      # clang release (e.g., sanitizers). We should probably remove the ones
      # we don't need and document the ones we want provide in addition to clang.
  
      # Latest CLANG_REVISION and CLANG_SUB_REVISION of the Chromiums's release
      # can be found in https://chromium.googlesource.com/chromium/src/tools/clang/+/master/scripts/update.py
      CLANG_REVISION = "347933"
      CLANG_SUB_REVISION = 1
  
      package_version = "%s-%s" % (CLANG_REVISION, CLANG_SUB_REVISION)
  
      checksums = {
          "Linux_x64": "cae3643fdf5d46fc9bc8731212bb37573547148d90b64b083165e090133d11b0",
          "Mac": "083a0e91a38c06e568652313ac7372b17a101268f7d65533d721ca30413442b4",
          "Win": "43160487cfc7e88076a369a2b6e8e4a0f42e104c28d8903f3aaa62d630aba949",
      }
  
      platform_folder = _get_platform_folder(repo_ctx.os.name)
      _download_chromium_clang(
          repo_ctx,
          platform_folder,
          package_version,
          checksums[platform_folder],
          out_folder,
      )
  
new_contents: """ Helpers to download a recent clang release."""
  
  def _get_platform_folder(os_name):
      os_name = os_name.lower()
      if os_name.startswith("windows"):
          return "Win"
      if os_name.startswith("mac os"):
          return "Mac"
      if not os_name.startswith("linux"):
          fail("Unknown platform")
      return "Linux_x64"
  
  def _download_chromium_clang(
          repo_ctx,
          platform_folder,
          package_version,
          sha256,
          out_folder):
      cds_url = "https://commondatastorage.googleapis.com/chromium-browser-clang"
      cds_file = "clang-%s.tgz" % package_version
      cds_full_url = "{0}/{1}/{2}".format(cds_url, platform_folder, cds_file)
      repo_ctx.download_and_extract(cds_full_url, output = out_folder, sha256 = sha256)
  
  def download_clang(repo_ctx, out_folder):
      """ Download a fresh clang release and put it into out_folder.
  
      Clang itself will be located in 'out_folder/bin/clang'.
      We currently download one of the latest releases of clang by the
      Chromium project (see
      https://chromium.googlesource.com/chromium/src/+/master/docs/clang.md).
  
      Args:
        repo_ctx: An instance of repository_context object.
        out_folder: A folder to extract the compiler into.
      """
      # TODO(ibiryukov): we currently download and extract some extra tools in the
      # clang release (e.g., sanitizers). We should probably remove the ones
      # we don't need and document the ones we want provide in addition to clang.
  
      # Latest CLANG_REVISION and CLANG_SUB_REVISION of the Chromiums's release
      # can be found in https://chromium.googlesource.com/chromium/src/tools/clang/+/master/scripts/update.py
      CLANG_REVISION = "348507"
      CLANG_SUB_REVISION = 1
  
      package_version = "%s-%s" % (CLANG_REVISION, CLANG_SUB_REVISION)
  
      checksums = {
          "Linux_x64": "85a24f215737af91e0054d3a1cb435bd8ff06178cef14241c029c8a04ff16a79",
          "Mac": "16a96a3c4b599d0418e812307087a223d5fee2ee3c7fd96f5cbc2a9e5bf8607d",
          "Win": "4c144f24d3a82d546845c680f5b029ff02dd4de7614e93d1b21cfc6e20a26dad",
      }
  
      platform_folder = _get_platform_folder(repo_ctx.os.name)
      _download_chromium_clang(
          repo_ctx,
          platform_folder,
          package_version,
          checksums[platform_folder],
          out_folder,
      )
  
subject: Update downloadable clang to r348507