bazel/bazel

#!/usr/bin/env python3
"""Runs the bazel executable for the platform, passing args along."""

import os
import os.path
import platform as plat
import subprocess
import sys


def main():
  workspace = find_workspace(os.path.dirname(os.path.realpath(__file__)))
  if not workspace:
    sys.exit('Must run %s within a workspace.' % os.path.basename(sys.argv[0]))
  if sys.platform.startswith('linux'):
    platform = 'linux-x86_64'
  elif sys.platform == 'darwin':
    platform = 'darwin-arm64' if plat.machine() == 'arm64' else 'darwin-x86_64'
  elif sys.platform == 'win32':
    platform = 'windows-x86_64'
  else:
    sys.exit('Platform %s is not yet supported.' % sys.platform)

  env = {}
  env['USE_BAZEL_VERSION'] = os.environ.get('USE_BAZEL_VERSION', '')
  bazel = [
      os.path.join(
          workspace, 'prebuilts', 'tools', platform, 'bazel', 'bazelisk'
      )
  ]
  # On linux bazel can sometimes hang due to RBE. So we kill it after
  # BAZEL_INVOCATION_TIMEOUT if set.
  if platform == 'linux-x86_64' and os.environ.get('BAZEL_INVOCATION_TIMEOUT'):
    bazel = [
        'timeout',
        '-k',
        '1m',
        os.environ['BAZEL_INVOCATION_TIMEOUT'],
    ] + bazel

  args = sys.argv[1:]
  command = bazel_command(args)

  env['TERM'] = os.environ.get('TERM', '')
  env['MAVEN_FETCH'] = os.environ.get('MAVEN_FETCH', '')
  env['SHELL'] = os.environ.get('SHELL', '')
  env['HOME'] = os.environ.get('HOME', '')
  env['DISPLAY'] = os.environ.get('DISPLAY', '')
  env['GOOGLE_APPLICATION_CREDENTIALS'] = os.environ.get(
      'GOOGLE_APPLICATION_CREDENTIALS', ''
  )
  env['PATH'] = os.environ.get('PATH', '')
  if 'GCE_METADATA_HOST' in os.environ:
    env['GCE_METADATA_HOST'] = os.environ.get('GCE_METADATA_HOST')
  if 'QA_ANDROID_SDK_ROOT' in os.environ:
    env['QA_ANDROID_SDK_ROOT'] = os.environ['QA_ANDROID_SDK_ROOT']
  if sys.platform == 'darwin':
    if not os.path.exists('/Library/Developer/CommandLineTools'):
      print(
          '/Library/Developer/CommandLineTools does not exist. Please install'
          ' it with xcode-select --install'
      )
      sys.exit(1)
    # This is needed for bazel to set itself up, even though we aren't using gcc.
    env['CC'] = os.environ.get('GCC', '/usr/bin/gcc')
  elif sys.platform == 'win32':
    # We don't need the tools to be installed locally if you're building remotely.
    # This isn't really the correct check, since --config=remote is just an alias for a bunch of other
    # settings. But in practice that's how you get into remote mode, so it should be good enough for now
    # at least.
    if command in ['build', 'test'] and (
        not '--config=remote' in args
        and not '--config=dynamic' in args
        and not '--config=ci' in args
    ):
      if not os.path.exists(
          'C:\\Program Files (x86)\\Microsoft Visual'
          ' Studio\\2019\\BuildTools\\VC\\Tools\\MSVC\\14.26.28801'
      ) or not os.path.exists(
          'C:\\Program Files (x86)\\Windows Kits\\10\\lib\\10.0.18362.0'
      ):
        print(
            'You must have MSVC Buildtools version 14.26.28801 and Windows SDK'
            ' 10.0.18362.0 installed.\nAn installer for these is available at'
            ' go/studio-msvc-tools.'
        )
        sys.exit(1)

    define_env(
        env,
        'BAZEL_SH',
        'C:\\tools\\msys64\\usr\\bin\\bash.exe',
        '***NOTE***: Bazel for Windows currently hardcodes "C:\\tools\\msys64",'
        ' but we\n'
        + 'could not find an installation of msys at this path on your'
        ' machine.\n'
        + 'Move your installation there if you already have it or\n'
        + 'install it there from http://www.msys2.org.\n'
        + 'Make sure to change the path to C:\\tools\\msys64\n'
        + '\n'
        + 'See also: https://github.com/bazelbuild/bazel/issues/2447',
    )
    # Bazel for windows requires a couple of extra env vars be set
    # SYSTEMROOT must be defined to run a win .exe; otherwise, subprocess.call
    # will hang.
    env['SYSTEMROOT'] = 'C:\\Windows'
    env['TMP'] = os.environ.get('TMP', '')
    env['USERPROFILE'] = os.environ.get('USERPROFILE', '')
    env['APPDATA'] = os.environ.get('APPDATA', '')
    env['LOCALAPPDATA'] = os.environ.get('LOCALAPPDATA', '')

  else:  # Linux
    env['CC'] = os.environ.get('GCC', '/usr/bin/gcc')
    env['SSH_AUTH_SOCK'] = os.environ.get('SSH_AUTH_SOCK', '')
    env['USER'] = os.environ.get('USER', '')

  sys.exit(subprocess.call(bazel + args, env=env))


def define_env(env, var, value, msg=None):
  prev = os.environ.get(var)
  if prev:
    if not os.path.exists(value):
      print('{} is set to {}, but it does not exist'.format(var, value))
      sys.exit(1)
    env[var] = prev
  elif os.path.exists(value):
    env[var] = value
  else:
    print('Cannot find {} while trying to set "{}"'.format(value, var))
    if msg:
      print(msg)
    else:
      print(
          'Make sure {} exists, or set "{}" manually to the correct value.'
          .format(value, var)
      )
    sys.exit(1)


def find_workspace(path):
  if os.path.isfile(os.path.join(path, 'WORKSPACE')):
    return path
  else:
    parent = os.path.dirname(path)
    return None if parent == path else find_workspace(parent)


def bazel_command_index(args):
  """Returns the command index, which is the first non-option argument.

  https://bazel.build/versions/master/docs/command-line-reference.html
  """
  for i in range(len(args)):
    if not args[i].startswith('-'):
      return i
  return None


def bazel_command(args):
  """Returns the command itself, or None if not defined."""
  index = bazel_command_index(args)
  if index is None:
    return None
  return args[index]


if __name__ == '__main__':
  main()