How to use the portage.os.path.join function in portage

def gen_label(base, label):
	"""if supplied label is a path, generate a unique label based upon label, and supplied base path"""
	if label.find(os.path.sep) == -1:
		return label
	label = label.strip("\"").strip("'")
	label = os.path.join(*(label.rstrip(os.path.sep).split(os.path.sep)))
	tail = os.path.split(label)[1]
	return "%s-%X" % (tail, abs(label.__hash__()))

if x.startswith(".") or x.endswith("~") or x.endswith(".bak"):
			continue
		templist.append(x)
	fns = templist
	del templist

	space_separated = set(["CONFIG_PROTECT", "CONFIG_PROTECT_MASK"])
	colon_separated = set(["ADA_INCLUDE_PATH", "ADA_OBJECTS_PATH",
		"CLASSPATH", "INFODIR", "INFOPATH", "KDEDIRS", "LDPATH", "MANPATH",
		  "PATH", "PKG_CONFIG_PATH", "PRELINK_PATH", "PRELINK_PATH_MASK",
		  "PYTHONPATH", "ROOTPATH"])

	config_list = []

	for x in fns:
		file_path = os.path.join(envd_dir, x)
		try:
			myconfig = getconfig(file_path, expand=False)
		except ParseError as e:
			writemsg("!!! '%s'\n" % str(e), noiselevel=-1)
			del e
			continue
		if myconfig is None:
			# broken symlink or file removed by a concurrent process
			writemsg("!!! File Not Found: '%s'\n" % file_path, noiselevel=-1)
			continue

		config_list.append(myconfig)
		if "SPACE_SEPARATED" in myconfig:
			space_separated.update(myconfig["SPACE_SEPARATED"].split())
			del myconfig["SPACE_SEPARATED"]
		if "COLON_SEPARATED" in myconfig:

dodir(destdir)
			dofile(fullpath, os.path.join(destdir, basename))
		elif warn_on_skipped_files and ext not in unwarned_skipped_extensions and basename not in unwarned_skipped_files:
			skipped_files.append(fullpath)
	elif options.recurse and os.path.isdir(fullpath) and \
	     basename not in options.disallowed_dirs:
		for i in _os.listdir(_unicode_encode(fullpath)):
			try:
				i = _unicode_decode(i, errors='strict')
			except UnicodeDecodeError:
				writemsg('dohtml: argument is not encoded as UTF-8: %s\n' %
					_unicode_decode(i), noiselevel=-1)
				sys.exit(1)
			pfx = basename
			if prefix:
				pfx = os.path.join(prefix, pfx)
			install(i, dirname, options, pfx)
	elif not options.recurse and os.path.isdir(fullpath):
		global skipped_directories
		skipped_directories.append(fullpath)
		return False
	else:
		return False
	return True

inst_gid = int(mysettings["PORTAGE_INST_GID"])

	_preinst_bsdflags(mysettings)

	destdir = mysettings["D"]
	ed_len = len(mysettings["ED"])
	unicode_errors = []
	desktop_file_validate = \
		portage.process.find_binary("desktop-file-validate") is not None
	xdg_dirs = mysettings.get('XDG_DATA_DIRS', '/usr/share').split(':')
	xdg_dirs = tuple(os.path.join(i, "applications") + os.sep
		for i in xdg_dirs if i)

	qa_desktop_file = ""
	try:
		with io.open(_unicode_encode(os.path.join(
			mysettings["PORTAGE_BUILDDIR"],
			"build-info", "QA_DESKTOP_FILE"),
			encoding=_encodings['fs'], errors='strict'),
			mode='r', encoding=_encodings['repo.content'],
			errors='replace') as f:
			qa_desktop_file = f.read()
	except IOError as e:
		if e.errno not in (errno.ENOENT, errno.ESTALE):
			raise

	qa_desktop_file = qa_desktop_file.split()
	if qa_desktop_file:
		if len(qa_desktop_file) > 1:
			qa_desktop_file = "|".join("(%s)" % x for x in qa_desktop_file)
			qa_desktop_file = "^(%s)$" % qa_desktop_file
		else:

def scan_pkgs(self, can_force):
		for xpkg in self.effective_scanlist:
			xpkg_continue = False
			# ebuilds and digests added to cvs respectively.
			logging.info("checking package %s", xpkg)
			# save memory by discarding xmatch caches from previous package(s)
			self.caches['arch_xmatch'].clear()
			catdir, pkgdir = xpkg.split("/")
			checkdir = self.repo_settings.repodir + "/" + xpkg
			checkdir_relative = ""
			if self.repolevel < 3:
				checkdir_relative = os.path.join(pkgdir, checkdir_relative)
			if self.repolevel < 2:
				checkdir_relative = os.path.join(catdir, checkdir_relative)
			checkdir_relative = os.path.join(".", checkdir_relative)

			# Run the status check
			if self.kwargs['checks']['ebuild_notadded']:
				self.vcs_settings.status.check(checkdir, checkdir_relative, xpkg)

			if self.generate_manifest:
				if not manifest.Manifest(**self.kwargs).update_manifest(checkdir):
					self.qatracker.add_error("manifest.bad", os.path.join(xpkg, 'Manifest'))
				if self.options.mode == 'manifest':
					continue
			checkdirlist = os.listdir(checkdir)

			dynamic_data = {
				'changelog_modified': False,
				'checkdirlist': ExtendedFuture(checkdirlist),
				'checkdir': checkdir,

def _chpathtool_exit(self, chpathtool):
		if self._final_exit(chpathtool) != os.EX_OK:
			self._writemsg_level("!!! Error Adjusting Prefix to %s\n" %
				(self.settings["EPREFIX"],),
				noiselevel=-1, level=logging.ERROR)
			self._async_unlock_builddir(returncode=self.returncode)
			return

		# We want to install in "our" prefix, not the binary one
		with io.open(_unicode_encode(os.path.join(self._infloc, "EPREFIX"),
			encoding=_encodings['fs'], errors='strict'), mode='w',
			encoding=_encodings['repo.content'], errors='strict') as f:
			f.write(self.settings["EPREFIX"] + "\n")

		# Move the files to the correct location for merge.
		image_tmp_dir = os.path.join(
			self.settings["PORTAGE_BUILDDIR"], "image_tmp")
		build_d = os.path.join(self.settings["D"],
			self._build_prefix.lstrip(os.sep))
		if not os.path.isdir(build_d):
			# Assume this is a virtual package or something.
			shutil.rmtree(self._image_dir)
			ensure_dirs(self.settings["ED"])
		else:
			os.rename(build_d, image_tmp_dir)
			shutil.rmtree(self._image_dir)
			ensure_dirs(os.path.dirname(self.settings["ED"].rstrip(os.sep)))
			os.rename(image_tmp_dir, self.settings["ED"])

		self.wait()

This is called in the parent process, serially, for each of the
		sync jobs when they complete. Some cache backends such as sqlite
		may require that cache access be performed serially in the
		parent process like this.
		"""
		repo = proc.kwargs['repo']
		exitcode = proc.returncode
		updatecache_flg = False
		if proc.returncode == os.EX_OK:
			exitcode, message, updatecache_flg, hooks_enabled = proc.result

		if updatecache_flg and "metadata-transfer" not in self.settings.features:
			updatecache_flg = False

		if updatecache_flg and \
			os.path.exists(os.path.join(
			repo.location, 'metadata', 'md5-cache')):

			# Only update cache for repo.location since that's
			# the only one that's been synced here.
			action_metadata(self.settings, self.portdb, self.emerge_config.opts,
				porttrees=[repo.location])

def _set_paths(self, **kwargs):
		repolevel = kwargs.get('repolevel')
		self.relative_path = os.path.join(self.xpkg, self.y_ebuild + ".ebuild")
		self.full_path = os.path.join(self.repo_settings.repodir, self.relative_path)
		self.ebuild_path = self.y_ebuild + ".ebuild"
		if repolevel < 3:
			self.ebuild_path = os.path.join(kwargs.get('pkgdir'), self.ebuild_path)
		if repolevel < 2:
			self.ebuild_path = os.path.join(kwargs.get('catdir'), self.ebuild_path)
		self.ebuild_path = os.path.join(".", self.ebuild_path)

for x in portage_bin_path:
			path.append(os.path.join(x, "ebuild-helpers", "xattr"))

	if uid != 0 and \
		"unprivileged" in settings.features and \
		"fakeroot" not in settings.features:
		for x in portage_bin_path:
			path.append(os.path.join(x,
				"ebuild-helpers", "unprivileged"))

	if settings.get("USERLAND", "GNU") != "GNU":
		for x in portage_bin_path:
			path.append(os.path.join(x, "ebuild-helpers", "bsd"))

	for x in portage_bin_path:
		path.append(os.path.join(x, "ebuild-helpers"))
	path.extend(prerootpath)

	for prefix in prefixes:
		prefix = prefix if prefix else "/"
		for x in ("usr/local/sbin", "usr/local/bin", "usr/sbin", "usr/bin", "sbin", "bin"):
			# Respect order defined in ROOTPATH
			x_abs = os.path.join(prefix, x)
			if x_abs not in rootpath_set:
				path.append(x_abs)

	path.extend(rootpath)
	settings["PATH"] = ":".join(path)

def _parse_profile_files_to_tuple_of_dicts(self, file_name, locations,
		juststrings=False, eapi_filter=None):
		return tuple(self._parse_file_to_dict(
			os.path.join(profile.location, file_name), juststrings,
			recursive=profile.portage1_directories, eapi_filter=eapi_filter,
			user_config=profile.user_config, eapi=profile.eapi,
			eapi_default=None, allow_build_id=profile.allow_build_id)
			for profile in locations)