python/mozboot/mozboot/mozconfig.py

   1 # This Source Code Form is subject to the terms of the Mozilla Public
   2 # License, v. 2.0. If a copy of the MPL was not distributed with this
   3 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   4
   5 import filecmp
   6 import os
   7 from pathlib import Path
   8 from typing import Union
   9
  10 MOZ_MYCONFIG_ERROR = """
  11 The MOZ_MYCONFIG environment variable to define the location of mozconfigs
  12 is deprecated. If you wish to define the mozconfig path via an environment
  13 variable, use MOZCONFIG instead.
  14 """.strip()
  15
  16 MOZCONFIG_LEGACY_PATH_ERROR = """
  17 You currently have a mozconfig at %s. This implicit location is no longer
  18 supported. Please move it to %s/.mozconfig or set an explicit path
  19 via the $MOZCONFIG environment variable.
  20 """.strip()
  21
  22 DEFAULT_TOPSRCDIR_PATHS = (".mozconfig", "mozconfig")
  23 DEPRECATED_TOPSRCDIR_PATHS = ("mozconfig.sh", "myconfig.sh")
  24 DEPRECATED_HOME_PATHS = (".mozconfig", ".mozconfig.sh", ".mozmyconfig.sh")
  25
  26
  27 class MozconfigFindException(Exception):
  28     """Raised when a mozconfig location is not defined properly."""
  29
  30
  31 class MozconfigBuilder(object):
  32     def __init__(self):
  33         self._lines = []
  34
  35     def append(self, block):
  36         self._lines.extend([line.strip() for line in block.split("\n") if line.strip()])
  37
  38     def generate(self):
  39         return "".join(line + "\n" for line in self._lines)
  40
  41
  42 def find_mozconfig(topsrcdir: Union[str, Path], env=os.environ):
  43     """Find the active mozconfig file for the current environment.
  44
  45     This emulates the logic in mozconfig-find.
  46
  47     1) If ENV[MOZCONFIG] is set, use that
  48     2) If $TOPSRCDIR/mozconfig or $TOPSRCDIR/.mozconfig exists, use it.
  49     3) If both exist or if there are legacy locations detected, error out.
  50
  51     The absolute path to the found mozconfig will be returned on success.
  52     None will be returned if no mozconfig could be found. A
  53     MozconfigFindException will be raised if there is a bad state,
  54     including conditions from #3 above.
  55     """
  56     topsrcdir = Path(topsrcdir)
  57
  58     # Check for legacy methods first.
  59     if "MOZ_MYCONFIG" in env:
  60         raise MozconfigFindException(MOZ_MYCONFIG_ERROR)
  61
  62     env_path = env.get("MOZCONFIG", None) or None
  63
  64     if env_path is not None:
  65         env_path = Path(env_path)
  66
  67     if env_path is not None:
  68         if not env_path.is_absolute():
  69             potential_roots = [topsrcdir, Path.cwd()]
  70             # Attempt to eliminate duplicates for e.g.
  71             # self.topsrcdir == Path.cwd().
  72             potential_roots_strings = set(str(p.resolve()) for p in potential_roots)
  73             existing = [
  74                 root
  75                 for root in potential_roots_strings
  76                 if (Path(root) / env_path).exists()
  77             ]
  78             if len(existing) > 1:
  79                 # There are multiple files, but we might have a setup like:
  80                 #
  81                 # somedirectory/
  82                 #   srcdir/
  83                 #   objdir/
  84                 #
  85                 # MOZCONFIG=../srcdir/some/path/to/mozconfig
  86                 #
  87                 # and be configuring from the objdir.  So even though we
  88                 # have multiple existing files, they are actually the same
  89                 # file.
  90                 mozconfigs = [root / env_path for root in existing]
  91                 if not all(
  92                     map(
  93                         lambda p1, p2: filecmp.cmp(p1, p2, shallow=False),
  94                         mozconfigs[:-1],
  95                         mozconfigs[1:],
  96                     )
  97                 ):
  98                     raise MozconfigFindException(
  99                         "MOZCONFIG environment variable refers to a path that "
 100                         + "exists in more than one of "
 101                         + ", ".join(potential_roots_strings)
 102                         + ". Remove all but one."
 103                     )
 104             elif not existing:
 105                 raise MozconfigFindException(
 106                     "MOZCONFIG environment variable refers to a path that "
 107                     + "does not exist in any of "
 108                     + ", ".join(potential_roots_strings)
 109                 )
 110
 111             env_path = existing[0] / env_path
 112         elif not env_path.exists():  # non-relative path
 113             raise MozconfigFindException(
 114                 "MOZCONFIG environment variable refers to a path that "
 115                 f"does not exist: {env_path}"
 116             )
 117
 118         if not env_path.is_file():
 119             raise MozconfigFindException(
 120                 "MOZCONFIG environment variable refers to a " f"non-file: {env_path}"
 121             )
 122
 123     srcdir_paths = [topsrcdir / p for p in DEFAULT_TOPSRCDIR_PATHS]
 124     existing = [p for p in srcdir_paths if p.is_file()]
 125
 126     if env_path is None and len(existing) > 1:
 127         raise MozconfigFindException(
 128             "Multiple default mozconfig files "
 129             "present. Remove all but one. " + ", ".join(str(p) for p in existing)
 130         )
 131
 132     path = None
 133
 134     if env_path is not None:
 135         path = env_path
 136     elif len(existing):
 137         assert len(existing) == 1
 138         path = existing[0]
 139
 140     if path is not None:
 141         return Path.cwd() / path
 142
 143     deprecated_paths = [topsrcdir / s for s in DEPRECATED_TOPSRCDIR_PATHS]
 144
 145     home = env.get("HOME", None)
 146     if home is not None:
 147         home = Path(home)
 148         deprecated_paths.extend([home / s for s in DEPRECATED_HOME_PATHS])
 149
 150     for path in deprecated_paths:
 151         if path.exists():
 152             raise MozconfigFindException(
 153                 MOZCONFIG_LEGACY_PATH_ERROR % (path, topsrcdir)
 154             )
 155
 156     return None