tools/python/runfiles/runfiles.py - bazel - Git at Google

 # Copyright 2018 The Bazel Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #    http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """Runfiles lookup library for Bazel-built Python binaries and tests.

 USAGE:

 1.  Depend on this runfiles library from your build rule:

       py_binary(
           name = "my_binary",
           ...
           deps = ["@rules_python//python/runfiles"],
       )

 2.  Import the runfiles library.

       from rules_python.python.runfiles import runfiles

 3.  Create a Runfiles object and use rlocation to look up runfile paths:

       r = runfiles.Create()
       ...
       with open(r.Rlocation("my_workspace/path/to/my/data.txt"), "r") as f:
         contents = f.readlines()
         ...

     The code above creates a manifest- or directory-based implementations based
     on the environment variables in os.environ. See `Create()` for more info.

     If you want to explicitly create a manifest- or directory-based
     implementations, you can do so as follows:

       r1 = runfiles.CreateManifestBased("path/to/foo.runfiles_manifest")

       r2 = runfiles.CreateDirectoryBased("path/to/foo.runfiles/")

     If you want to start subprocesses that also need runfiles, you need to set
     the right environment variables for them:

       import subprocess
       from rules_python.python.runfiles import runfiles

       r = runfiles.Create()
       env = {}
       ...
       env.update(r.EnvVars())
       p = subprocess.Popen([r.Rlocation("path/to/binary")], env, ...)
 """

 import inspect
 import os
 import posixpath
 import sys

 from ._runfiles_constants import MAIN_REPOSITORY_RUNFILES_DIRECTORY


 def CreateManifestBased(manifest_path):
   return _Runfiles(_ManifestBased(manifest_path))


 def CreateDirectoryBased(runfiles_dir_path):
   return _Runfiles(_DirectoryBased(runfiles_dir_path))


 def Create(env=None):
   """Returns a new `Runfiles` instance.

   The returned object is either:
   - manifest-based, meaning it looks up runfile paths from a manifest file, or
   - directory-based, meaning it looks up runfile paths under a given directory
     path

   If `env` contains "RUNFILES_MANIFEST_FILE" with non-empty value, this method
   returns a manifest-based implementation. The object eagerly reads and caches
   the whole manifest file upon instantiation; this may be relevant for
   performance consideration.

   Otherwise, if `env` contains "RUNFILES_DIR" with non-empty value (checked in
   this priority order), this method returns a directory-based implementation.

   If neither cases apply, this method returns null.

   Args:
     env: {string: string}; optional; the map of environment variables. If None,
         this function uses the environment variable map of this process.
   Raises:
     IOError: if some IO error occurs.
   """
   env_map = os.environ if env is None else env
   manifest = env_map.get("RUNFILES_MANIFEST_FILE")
   if manifest:
     return CreateManifestBased(manifest)

   directory = env_map.get("RUNFILES_DIR")
   if not directory:
     directory = env_map.get("PYTHON_RUNFILES")
   if directory:
     return CreateDirectoryBased(directory)

   return None


 class _Runfiles(object):
   """Returns the runtime location of runfiles.

   Runfiles are data-dependencies of Bazel-built binaries and tests.
   """

   def __init__(self, strategy):
     self._strategy = strategy
     self._python_runfiles_root = _FindPythonRunfilesRoot()

   def Rlocation(self, path):
     """Returns the runtime path of a runfile.

     Runfiles are data-dependencies of Bazel-built binaries and tests.

     The returned path may not be valid. The caller should check the path's
     validity and that the path exists.

     The function may return None. In that case the caller can be sure that the
     rule does not know about this data-dependency.

     Args:
       path: string; runfiles-root-relative path of the runfile
     Returns:
       the path to the runfile, which the caller should check for existence, or
       None if the method doesn't know about this runfile
     Raises:
       TypeError: if `path` is not a string
       ValueError: if `path` is None or empty, or it's absolute or not normalized
     """
     if not path:
       raise ValueError()
     if not isinstance(path, str):
       raise TypeError()
     if (path.startswith("../") or "/.." in path or path.startswith("./") or
         "/./" in path or path.endswith("/.") or "//" in path):
       raise ValueError("path is not normalized: \"%s\"" % path)
     if path[0] == "\\":
       raise ValueError("path is absolute without a drive letter: \"%s\"" % path)
     if os.path.isabs(path):
       return path
     return self._strategy.RlocationChecked(path)

   def EnvVars(self):
     """Returns environment variables for subprocesses.

     The caller should set the returned key-value pairs in the environment of
     subprocesses in case those subprocesses are also Bazel-built binaries that
     need to use runfiles.

     Returns:
       {string: string}; a dict; keys are environment variable names, values are
       the values for these environment variables
     """
     return self._strategy.EnvVars()

   def CurrentRepository(self, frame=1):
     """Returns the canonical name of the caller's Bazel repository.

     For example, this function returns '' (the empty string) when called from
     the main repository and a string of the form 'rules_python+0.13.0` when
     called from code in the repository corresponding to the rules_python Bazel
     module.

     More information about the difference between canonical repository names and
     the `@repo` part of labels is available at:
     https://bazel.build/build/bzlmod#repository-names

     NOTE: This function inspects the callstack to determine where in the
     runfiles the caller is located to determine which repository it came from.
     This may fail or produce incorrect results depending on who the caller is,
     for example if it is not represented by a Python source file. Use the
     `frame` argument to control the stack lookup.

     Args:
       frame: int; the stack frame to return the repository name for. Defaults to
         1, the caller of the CurrentRepository function.

     Returns:
       The canonical name of the Bazel repository containing the file containing
       the frame-th caller of this function
     Raises:
       ValueError: if the caller cannot be determined or the caller's file path
           is not contained in the Python runfiles tree
     """
     # pylint:disable=protected-access  # for sys._getframe
     # pylint:disable=raise-missing-from  # we're still supporting Python 2...
     try:
       caller_path = inspect.getfile(sys._getframe(frame))
     except (TypeError, ValueError):
       raise ValueError("failed to determine caller's file path")
     caller_runfiles_path = os.path.relpath(caller_path,
                                            self._python_runfiles_root)
     if caller_runfiles_path.startswith(".." + os.path.sep):
       raise ValueError("{} does not lie under the runfiles root {}".format(
           caller_path, self._python_runfiles_root))

     caller_runfiles_directory = caller_runfiles_path[:caller_runfiles_path
                                                      .find(os.path.sep)]
     if caller_runfiles_directory == MAIN_REPOSITORY_RUNFILES_DIRECTORY:
       # The canonical name of the main repository (also known as the workspace)
       # is the empty string.
       return ""
     # For all other repositories, the name of the runfiles directory is the
     # canonical name.
     return caller_runfiles_directory


 def _FindPythonRunfilesRoot():
   """Finds the root of the Python runfiles tree."""
   root = __file__
   # Walk up our own runfiles path to the root of the runfiles tree from which
   # the current file is being run. This path coincides with what the Bazel
   # Python stub sets up as sys.path[0]. Since that entry can be changed at
   # runtime, we rederive it here.
   for _ in range(
       "bazel_tools/tools/python/runfiles/runfiles.py".count("/") +
       1):
     root = os.path.dirname(root)
   return root


 class _ManifestBased(object):
   """`Runfiles` strategy that parses a runfiles-manifest to look up runfiles."""

   def __init__(self, path):
     if not path:
       raise ValueError()
     if not isinstance(path, str):
       raise TypeError()
     self._path = path
     self._runfiles = _ManifestBased._LoadRunfiles(path)

   def RlocationChecked(self, path):
     """Returns the runtime path of a runfile."""
     exact_match = self._runfiles.get(path)
     if exact_match:
       return exact_match
     # If path references a runfile that lies under a directory that itself is a
     # runfile, then only the directory is listed in the manifest. Look up all
     # prefixes of path in the manifest and append the relative path from the
     # prefix to the looked up path.
     prefix_end = len(path)
     while True:
       prefix_end = path.rfind("/", 0, prefix_end - 1)
       if prefix_end == -1:
         return None
       prefix_match = self._runfiles.get(path[0:prefix_end])
       if prefix_match:
         return prefix_match + "/" + path[prefix_end + 1:]

   @staticmethod
   def _LoadRunfiles(path):
     """Loads the runfiles manifest."""
     result = {}
     with open(path, "r") as f:
       for line in f:
         line = line.strip()
         if line:
           tokens = line.split(" ", 1)
           if len(tokens) == 1:
             result[line] = line
           else:
             result[tokens[0]] = tokens[1]
     return result

   def _GetRunfilesDir(self):
     if self._path.endswith("/MANIFEST") or self._path.endswith("\\MANIFEST"):
       return self._path[:-len("/MANIFEST")]
     elif self._path.endswith(".runfiles_manifest"):
       return self._path[:-len("_manifest")]
     else:
       return ""

   def EnvVars(self):
     directory = self._GetRunfilesDir()
     return {
         "RUNFILES_MANIFEST_FILE": self._path,
         "RUNFILES_DIR": directory,
         # TODO(laszlocsomor): remove JAVA_RUNFILES once the Java launcher can
         # pick up RUNFILES_DIR.
         "JAVA_RUNFILES": directory,
     }


 class _DirectoryBased(object):
   """`Runfiles` strategy that appends runfiles paths to the runfiles root."""

   def __init__(self, path):
     if not path:
       raise ValueError()
     if not isinstance(path, str):
       raise TypeError()
     self._runfiles_root = path

   def RlocationChecked(self, path):
     # Use posixpath instead of os.path, because Bazel only creates a runfiles
     # tree on Unix platforms, so `Create()` will only create a directory-based
     # runfiles strategy on those platforms.
     return posixpath.join(self._runfiles_root, path)

   def EnvVars(self):
     return {
         "RUNFILES_DIR": self._runfiles_root,
         # TODO(laszlocsomor): remove JAVA_RUNFILES once the Java launcher can
         # pick up RUNFILES_DIR.
         "JAVA_RUNFILES": self._runfiles_root,
     }


 def _PathsFrom(argv0, runfiles_mf, runfiles_dir, is_runfiles_manifest,
                is_runfiles_directory):
   """Discover runfiles manifest and runfiles directory paths.

   Args:
     argv0: string; the value of sys.argv[0]
     runfiles_mf: string; the value of the RUNFILES_MANIFEST_FILE environment
       variable
     runfiles_dir: string; the value of the RUNFILES_DIR environment variable
     is_runfiles_manifest: lambda(string):bool; returns true if the argument is
       the path of a runfiles manifest file
     is_runfiles_directory: lambda(string):bool; returns true if the argument is
       the path of a runfiles directory

   Returns:
     (string, string) pair, first element is the path to the runfiles manifest,
     second element is the path to the runfiles directory. If the first element
     is non-empty, then is_runfiles_manifest returns true for it. Same goes for
     the second element and is_runfiles_directory respectively. If both elements
     are empty, then this function could not find a manifest or directory for
     which is_runfiles_manifest or is_runfiles_directory returns true.
   """
   mf_alid = is_runfiles_manifest(runfiles_mf)
   dir_valid = is_runfiles_directory(runfiles_dir)

   if not mf_alid and not dir_valid:
     runfiles_mf = argv0 + ".runfiles/MANIFEST"
     runfiles_dir = argv0 + ".runfiles"
     mf_alid = is_runfiles_manifest(runfiles_mf)
     dir_valid = is_runfiles_directory(runfiles_dir)
     if not mf_alid:
       runfiles_mf = argv0 + ".runfiles_manifest"
       mf_alid = is_runfiles_manifest(runfiles_mf)

   if not mf_alid and not dir_valid:
     return ("", "")

   if not mf_alid:
     runfiles_mf = runfiles_dir + "/MANIFEST"
     mf_alid = is_runfiles_manifest(runfiles_mf)
     if not mf_alid:
       runfiles_mf = runfiles_dir + "_manifest"
       mf_alid = is_runfiles_manifest(runfiles_mf)

   if not dir_valid:
     runfiles_dir = runfiles_mf[:-9]  # "_manifest" or "/MANIFEST"
     dir_valid = is_runfiles_directory(runfiles_dir)

   return (runfiles_mf if mf_alid else "", runfiles_dir if dir_valid else "")
	# Copyright 2018 The Bazel Authors. All rights reserved.
	#
	# Licensed under the Apache License, Version 2.0 (the "License");
	# you may not use this file except in compliance with the License.
	# You may obtain a copy of the License at
	#
	# http://www.apache.org/licenses/LICENSE-2.0
	#
	# Unless required by applicable law or agreed to in writing, software
	# distributed under the License is distributed on an "AS IS" BASIS,
	# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	# See the License for the specific language governing permissions and
	# limitations under the License.
	"""Runfiles lookup library for Bazel-built Python binaries and tests.

	USAGE:

	1. Depend on this runfiles library from your build rule:

	py_binary(
	name = "my_binary",
	...
	deps = ["@rules_python//python/runfiles"],
	)

	2. Import the runfiles library.

	from rules_python.python.runfiles import runfiles

	3. Create a Runfiles object and use rlocation to look up runfile paths:

	r = runfiles.Create()
	...
	with open(r.Rlocation("my_workspace/path/to/my/data.txt"), "r") as f:
	contents = f.readlines()
	...

	The code above creates a manifest- or directory-based implementations based
	on the environment variables in os.environ. See `Create()` for more info.

	If you want to explicitly create a manifest- or directory-based
	implementations, you can do so as follows:

	r1 = runfiles.CreateManifestBased("path/to/foo.runfiles_manifest")

	r2 = runfiles.CreateDirectoryBased("path/to/foo.runfiles/")

	If you want to start subprocesses that also need runfiles, you need to set
	the right environment variables for them:

	import subprocess
	from rules_python.python.runfiles import runfiles

	r = runfiles.Create()
	env = {}
	...
	env.update(r.EnvVars())
	p = subprocess.Popen([r.Rlocation("path/to/binary")], env, ...)
	"""

	import inspect
	import os
	import posixpath
	import sys

	from ._runfiles_constants import MAIN_REPOSITORY_RUNFILES_DIRECTORY


	def CreateManifestBased(manifest_path):
	return _Runfiles(_ManifestBased(manifest_path))


	def CreateDirectoryBased(runfiles_dir_path):
	return _Runfiles(_DirectoryBased(runfiles_dir_path))


	def Create(env=None):
	"""Returns a new `Runfiles` instance.

	The returned object is either:
	- manifest-based, meaning it looks up runfile paths from a manifest file, or
	- directory-based, meaning it looks up runfile paths under a given directory
	path

	If `env` contains "RUNFILES_MANIFEST_FILE" with non-empty value, this method
	returns a manifest-based implementation. The object eagerly reads and caches
	the whole manifest file upon instantiation; this may be relevant for
	performance consideration.

	Otherwise, if `env` contains "RUNFILES_DIR" with non-empty value (checked in
	this priority order), this method returns a directory-based implementation.

	If neither cases apply, this method returns null.

	Args:
	env: {string: string}; optional; the map of environment variables. If None,
	this function uses the environment variable map of this process.
	Raises:
	IOError: if some IO error occurs.
	"""
	env_map = os.environ if env is None else env
	manifest = env_map.get("RUNFILES_MANIFEST_FILE")
	if manifest:
	return CreateManifestBased(manifest)

	directory = env_map.get("RUNFILES_DIR")
	if not directory:
	directory = env_map.get("PYTHON_RUNFILES")
	if directory:
	return CreateDirectoryBased(directory)

	return None


	class _Runfiles(object):
	"""Returns the runtime location of runfiles.

	Runfiles are data-dependencies of Bazel-built binaries and tests.
	"""

	def __init__(self, strategy):
	self._strategy = strategy
	self._python_runfiles_root = _FindPythonRunfilesRoot()

	def Rlocation(self, path):
	"""Returns the runtime path of a runfile.

	Runfiles are data-dependencies of Bazel-built binaries and tests.

	The returned path may not be valid. The caller should check the path's
	validity and that the path exists.

	The function may return None. In that case the caller can be sure that the
	rule does not know about this data-dependency.

	Args:
	path: string; runfiles-root-relative path of the runfile
	Returns:
	the path to the runfile, which the caller should check for existence, or
	None if the method doesn't know about this runfile
	Raises:
	TypeError: if `path` is not a string
	ValueError: if `path` is None or empty, or it's absolute or not normalized
	"""
	if not path:
	raise ValueError()
	if not isinstance(path, str):
	raise TypeError()
	if (path.startswith("../") or "/.." in path or path.startswith("./") or
	"/./" in path or path.endswith("/.") or "//" in path):
	raise ValueError("path is not normalized: \"%s\"" % path)
	if path[0] == "\\":
	raise ValueError("path is absolute without a drive letter: \"%s\"" % path)
	if os.path.isabs(path):
	return path
	return self._strategy.RlocationChecked(path)

	def EnvVars(self):
	"""Returns environment variables for subprocesses.

	The caller should set the returned key-value pairs in the environment of
	subprocesses in case those subprocesses are also Bazel-built binaries that
	need to use runfiles.

	Returns:
	{string: string}; a dict; keys are environment variable names, values are
	the values for these environment variables
	"""
	return self._strategy.EnvVars()

	def CurrentRepository(self, frame=1):
	"""Returns the canonical name of the caller's Bazel repository.

	For example, this function returns '' (the empty string) when called from
	the main repository and a string of the form 'rules_python+0.13.0` when
	called from code in the repository corresponding to the rules_python Bazel
	module.

	More information about the difference between canonical repository names and
	the `@repo` part of labels is available at:
	https://bazel.build/build/bzlmod#repository-names

	NOTE: This function inspects the callstack to determine where in the
	runfiles the caller is located to determine which repository it came from.
	This may fail or produce incorrect results depending on who the caller is,
	for example if it is not represented by a Python source file. Use the
	`frame` argument to control the stack lookup.

	Args:
	frame: int; the stack frame to return the repository name for. Defaults to
	1, the caller of the CurrentRepository function.

	Returns:
	The canonical name of the Bazel repository containing the file containing
	the frame-th caller of this function
	Raises:
	ValueError: if the caller cannot be determined or the caller's file path
	is not contained in the Python runfiles tree
	"""
	# pylint:disable=protected-access # for sys._getframe
	# pylint:disable=raise-missing-from # we're still supporting Python 2...
	try:
	caller_path = inspect.getfile(sys._getframe(frame))
	except (TypeError, ValueError):
	raise ValueError("failed to determine caller's file path")
	caller_runfiles_path = os.path.relpath(caller_path,
	self._python_runfiles_root)
	if caller_runfiles_path.startswith(".." + os.path.sep):
	raise ValueError("{} does not lie under the runfiles root {}".format(
	caller_path, self._python_runfiles_root))

	caller_runfiles_directory = caller_runfiles_path[:caller_runfiles_path
	.find(os.path.sep)]
	if caller_runfiles_directory == MAIN_REPOSITORY_RUNFILES_DIRECTORY:
	# The canonical name of the main repository (also known as the workspace)
	# is the empty string.
	return ""
	# For all other repositories, the name of the runfiles directory is the
	# canonical name.
	return caller_runfiles_directory


	def _FindPythonRunfilesRoot():
	"""Finds the root of the Python runfiles tree."""
	root = __file__
	# Walk up our own runfiles path to the root of the runfiles tree from which
	# the current file is being run. This path coincides with what the Bazel
	# Python stub sets up as sys.path[0]. Since that entry can be changed at
	# runtime, we rederive it here.
	for _ in range(
	"bazel_tools/tools/python/runfiles/runfiles.py".count("/") +
	1):
	root = os.path.dirname(root)
	return root


	class _ManifestBased(object):
	"""`Runfiles` strategy that parses a runfiles-manifest to look up runfiles."""

	def __init__(self, path):
	if not path:
	raise ValueError()
	if not isinstance(path, str):
	raise TypeError()
	self._path = path
	self._runfiles = _ManifestBased._LoadRunfiles(path)

	def RlocationChecked(self, path):
	"""Returns the runtime path of a runfile."""
	exact_match = self._runfiles.get(path)
	if exact_match:
	return exact_match
	# If path references a runfile that lies under a directory that itself is a
	# runfile, then only the directory is listed in the manifest. Look up all
	# prefixes of path in the manifest and append the relative path from the
	# prefix to the looked up path.
	prefix_end = len(path)
	while True:
	prefix_end = path.rfind("/", 0, prefix_end - 1)
	if prefix_end == -1:
	return None
	prefix_match = self._runfiles.get(path[0:prefix_end])
	if prefix_match:
	return prefix_match + "/" + path[prefix_end + 1:]

	@staticmethod
	def _LoadRunfiles(path):
	"""Loads the runfiles manifest."""
	result = {}
	with open(path, "r") as f:
	for line in f:
	line = line.strip()
	if line:
	tokens = line.split(" ", 1)
	if len(tokens) == 1:
	result[line] = line
	else:
	result[tokens[0]] = tokens[1]
	return result

	def _GetRunfilesDir(self):
	if self._path.endswith("/MANIFEST") or self._path.endswith("\\MANIFEST"):
	return self._path[:-len("/MANIFEST")]
	elif self._path.endswith(".runfiles_manifest"):
	return self._path[:-len("_manifest")]
	else:
	return ""

	def EnvVars(self):
	directory = self._GetRunfilesDir()
	return {
	"RUNFILES_MANIFEST_FILE": self._path,
	"RUNFILES_DIR": directory,
	# TODO(laszlocsomor): remove JAVA_RUNFILES once the Java launcher can
	# pick up RUNFILES_DIR.
	"JAVA_RUNFILES": directory,
	}


	class _DirectoryBased(object):
	"""`Runfiles` strategy that appends runfiles paths to the runfiles root."""

	def __init__(self, path):
	if not path:
	raise ValueError()
	if not isinstance(path, str):
	raise TypeError()
	self._runfiles_root = path

	def RlocationChecked(self, path):
	# Use posixpath instead of os.path, because Bazel only creates a runfiles
	# tree on Unix platforms, so `Create()` will only create a directory-based
	# runfiles strategy on those platforms.
	return posixpath.join(self._runfiles_root, path)

	def EnvVars(self):
	return {
	"RUNFILES_DIR": self._runfiles_root,
	# TODO(laszlocsomor): remove JAVA_RUNFILES once the Java launcher can
	# pick up RUNFILES_DIR.
	"JAVA_RUNFILES": self._runfiles_root,
	}


	def _PathsFrom(argv0, runfiles_mf, runfiles_dir, is_runfiles_manifest,
	is_runfiles_directory):
	"""Discover runfiles manifest and runfiles directory paths.

	Args:
	argv0: string; the value of sys.argv[0]
	runfiles_mf: string; the value of the RUNFILES_MANIFEST_FILE environment
	variable
	runfiles_dir: string; the value of the RUNFILES_DIR environment variable
	is_runfiles_manifest: lambda(string):bool; returns true if the argument is
	the path of a runfiles manifest file
	is_runfiles_directory: lambda(string):bool; returns true if the argument is
	the path of a runfiles directory

	Returns:
	(string, string) pair, first element is the path to the runfiles manifest,
	second element is the path to the runfiles directory. If the first element
	is non-empty, then is_runfiles_manifest returns true for it. Same goes for
	the second element and is_runfiles_directory respectively. If both elements
	are empty, then this function could not find a manifest or directory for
	which is_runfiles_manifest or is_runfiles_directory returns true.
	"""
	mf_alid = is_runfiles_manifest(runfiles_mf)
	dir_valid = is_runfiles_directory(runfiles_dir)

	if not mf_alid and not dir_valid:
	runfiles_mf = argv0 + ".runfiles/MANIFEST"
	runfiles_dir = argv0 + ".runfiles"
	mf_alid = is_runfiles_manifest(runfiles_mf)
	dir_valid = is_runfiles_directory(runfiles_dir)
	if not mf_alid:
	runfiles_mf = argv0 + ".runfiles_manifest"
	mf_alid = is_runfiles_manifest(runfiles_mf)

	if not mf_alid and not dir_valid:
	return ("", "")

	if not mf_alid:
	runfiles_mf = runfiles_dir + "/MANIFEST"
	mf_alid = is_runfiles_manifest(runfiles_mf)
	if not mf_alid:
	runfiles_mf = runfiles_dir + "_manifest"
	mf_alid = is_runfiles_manifest(runfiles_mf)

	if not dir_valid:
	runfiles_dir = runfiles_mf[:-9] # "_manifest" or "/MANIFEST"
	dir_valid = is_runfiles_directory(runfiles_dir)

	return (runfiles_mf if mf_alid else "", runfiles_dir if dir_valid else "")