Read a libtbx environment file and dump it's structure to the terminal

read_env.py

#!/usr/bin/env python3

"""
Reads a libtbx_env file and dumps the entire contents.

Some structures e.g. module dictionaries refer to the same object in multiple
places. These will be dumped multiple times. Anything that refers back to a
previous level will show as "__selfreference__". Relocatable paths are just
shown as the regular, joined path (from inspection all base off of the build
path anyway).

Usage:
  read_env.py <libtbx_env>
"""

import pickle
import yaml
from pprint import pprint
import sys
from types import ModuleType
import os

def _read_obj(obj, prev=None):
  if prev is None:
    prev = []
  if obj in prev:
    return "__selfreference__"
  prev = list(prev) + [obj]

  if isinstance(obj, prop_object):
    return {name: _read_obj(val, prev) for name, val in obj.__dict__.items()}
  elif isinstance(obj, list):
    p = []
    for i in obj:
      p.append(_read_obj(i, prev))
    return p
  elif isinstance(obj, dict):
    return {a: _read_obj(b, prev) for a, b in obj.items()}
  else:
    return obj

class prop_object(object):
  """Object that can convert itself to a dictionary"""
  def to_dict(self):
    return _read_obj(self)

class relocatable_path(object):
  def __repr__(self):
    return '"' + os.path.normpath(os.path.join(self._anchor._path,self.relocatable)) + '"'

class absolute_path(object):
  def __repr__(self):
    return '"{}"'.format(self._path)

def _new_module(name, doc=None):
  """Create a new module and inject it into sys.modules"""
  m = ModuleType(name, doc)
  m.__file__ = name + '.py'
  sys.modules[name] = m
  return m

def _install_fake_libtbx():
  # Create the fake libtbx environment
  libtbx = _new_module("libtbx")
  libtbx.env_config = _new_module("libtbx.env_config")
  libtbx.path = _new_module("libtbx.path")
  libtbx.env_config.environment = prop_object
  libtbx.env_config.build_options = prop_object
  libtbx.env_config.module = prop_object
  libtbx.path.relocatable_path = relocatable_path
  libtbx.path.absolute_path = absolute_path

# Look for arguments
if __name__ == "__main__":
  if "--help" in sys.argv or "-h" in sys.argv:
    print(__doc__)
  elif len(sys.argv) != 2:
    print("Usage: read_env.py <libtbx_env>")
  elif not os.path.isfile(sys.argv[1]):
    print("Error: {} is not a file.".format(sys.argv[1]))
  else:
    _install_fake_libtbx()
    # Load the environment dump
    env = pickle.load(open(sys.argv[1],"rb"))
    d = env.to_dict()
    pprint(d)