| # 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 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 "") |