mach

   1 #!/usr/bin/env python3
   2 # This Source Code Form is subject to the terms of the Mozilla Public
   3 # License, v. 2.0. If a copy of the MPL was not distributed with this
   4 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   5
   6 import os
   7 import platform
   8 import sys
   9 import subprocess
  10 import traceback
  11 from textwrap import dedent, fill
  12
  13 MIN_PYTHON_VERSION = (3, 7)
  14 MAX_PYTHON_VERSION_TO_CONSIDER = (3, 11)
  15
  16
  17 def load_mach(dir_path, mach_path, args):
  18     # Defer import of "importlib.util" until after Python version check has happened
  19     # so that Python 2 usages fail gracefully.
  20     import importlib.util
  21
  22     spec = importlib.util.spec_from_file_location("mach_initialize", mach_path)
  23     mach_initialize = importlib.util.module_from_spec(spec)
  24     spec.loader.exec_module(mach_initialize)
  25     return mach_initialize.initialize(dir_path, args)
  26
  27
  28 def check_and_get_mach(dir_path, args):
  29     initialize_paths = (
  30         # Run Thunderbird's mach_initialize.py if it exists
  31         "comm/build/mach_initialize.py",
  32         "build/mach_initialize.py",
  33         # test package initialize
  34         "tools/mach_initialize.py",
  35     )
  36     for initialize_path in initialize_paths:
  37         mach_path = os.path.join(dir_path, initialize_path)
  38         if os.path.isfile(mach_path):
  39             return load_mach(dir_path, mach_path, args)
  40     return None
  41
  42
  43 def find_alternate_python3_executables():
  44     for i in range(MIN_PYTHON_VERSION[1], MAX_PYTHON_VERSION_TO_CONSIDER[1] + 1):
  45         potential_python_binary = f"python3.{i}"
  46         if os.name == "nt":
  47             potential_python_binary += ".exe"
  48
  49         try:
  50             out = subprocess.run(
  51                 [potential_python_binary, "--version"],
  52                 stdout=subprocess.PIPE,
  53                 stderr=subprocess.PIPE,
  54                 encoding="UTF-8",
  55             )
  56
  57             binary_minor_version = int(out.stdout[9:11].strip("."))
  58
  59             if binary_minor_version >= MIN_PYTHON_VERSION[1]:
  60                 yield potential_python_binary
  61
  62         except Exception:
  63             pass
  64
  65
  66 def try_alternate_python3_executables(args):
  67     for potential_python_binary in find_alternate_python3_executables():
  68         try:
  69             print(
  70                 f"We found '{potential_python_binary}' and will attempt to re-run Mach with it."
  71             )
  72             os.execvp(
  73                 potential_python_binary, [potential_python_binary] + ["mach"] + args
  74             )
  75         except Exception:
  76             # We don't really care what goes wrong, just don't let it bubble up
  77             # If we can't successfully launch with a different python3 binary
  78             # we will just print the normal help messages.
  79             pass
  80
  81
  82 def main(args):
  83     # Ensure we are running Python 3.7+. We run this check as soon as
  84     # possible to avoid a cryptic import/usage error.
  85     if sys.version_info < MIN_PYTHON_VERSION:
  86         print(
  87             f"Python {MIN_PYTHON_VERSION[0]}.{MIN_PYTHON_VERSION[1]}+ is required to run mach."
  88         )
  89         print("You are running Mach with Python {0}".format(platform.python_version()))
  90         try_alternate_python3_executables(args)
  91         if sys.platform.startswith("linux"):
  92             print(
  93                 dedent(
  94                     """
  95             See https://firefox-source-docs.mozilla.org/setup/linux_build.html#installingpython
  96             for guidance on how to install Python on your system.
  97             """
  98                 ).strip()
  99             )
 100         elif sys.platform.startswith("darwin"):
 101             print(
 102                 dedent(
 103                     """
 104             See https://firefox-source-docs.mozilla.org/setup/macos_build.html
 105             for guidance on how to prepare your system to build Firefox. Perhaps
 106             you need to update Xcode, or install Python using brew?
 107             """
 108                 ).strip()
 109             )
 110         elif "MOZILLABUILD" in os.environ and os.environ.get("TERM"):
 111             print(
 112                 dedent(
 113                     """
 114             Python is provided by MozillaBuild; ensure your MozillaBuild installation is
 115             up to date. See https://firefox-source-docs.mozilla.org/setup/windows_build.html#install-mozillabuild
 116             for details.
 117             """
 118                 ).strip()
 119             )
 120         elif sys.platform.startswith("win"):
 121             print(
 122                 dedent(
 123                     """
 124             You probably want to be interacting with Mach from within MozillaBuild, see
 125             https://firefox-source-docs.mozilla.org/setup/windows_build.html for details.
 126
 127             If you are deliberately using Mach from outside MozillaBuild, then see
 128             https://firefox-source-docs.mozilla.org/mach/windows-usage-outside-mozillabuild.html#install-python
 129             for guidance on installing native Python on your system.
 130             """
 131                 ).strip()
 132             )
 133         else:
 134             print(
 135                 dedent(
 136                     """
 137             We do not have specific instructions for your platform on how to
 138             install Python. You may find Pyenv (https://github.com/pyenv/pyenv)
 139             helpful, if your system package manager does not provide a way to
 140             install a recent enough Python 3.
 141             """
 142                 ).strip()
 143             )
 144         sys.exit(1)
 145
 146     # XCode python sets __PYVENV_LAUNCHER__, which overrides the executable
 147     # used when a python subprocess is created. This is an issue when we want
 148     # to run using our virtualenv python executables.
 149     # In future Python relases, __PYVENV_LAUNCHER__ will be cleared before
 150     # application code (mach) is started.
 151     # https://github.com/python/cpython/pull/9516
 152     os.environ.pop("__PYVENV_LAUNCHER__", None)
 153
 154     try:
 155         mach = check_and_get_mach(os.path.dirname(os.path.realpath(__file__)), args)
 156         if not mach:
 157             print("Could not run mach: No mach source directory found.")
 158             sys.exit(1)
 159         sys.exit(mach.run(args))
 160     except (KeyboardInterrupt, SystemExit):
 161         raise
 162     except Exception as e:
 163         if sys.version_info >= (
 164             MAX_PYTHON_VERSION_TO_CONSIDER[0],
 165             MAX_PYTHON_VERSION_TO_CONSIDER[1] + 1,
 166         ):
 167             traceback.print_exc()
 168             print()
 169             print("---")
 170             print()
 171             print(
 172                 fill(
 173                     dedent(
 174                         f"""\
 175                 Note that you are running Mach with Python
 176                 {platform.python_version()}, which is higher than the highest
 177                 known working version of Python for Mach. Consider running Mach
 178                 with Python {MAX_PYTHON_VERSION_TO_CONSIDER[0]}.{MAX_PYTHON_VERSION_TO_CONSIDER[1]}
 179                 or lower."""
 180                     )
 181                 )
 182             )
 183
 184             try:
 185                 alternative = next(find_alternate_python3_executables())
 186                 print()
 187                 print("Running the following command may solve your issue:")
 188                 print()
 189                 print(f"    {alternative} {sys.argv[0]} {' '.join(args)}")
 190                 print()
 191             except StopIteration:
 192                 pass
 193             sys.exit(1)
 194         else:
 195             raise
 196
 197
 198 if __name__ == "__main__":
 199     main(sys.argv[1:])