llvm_tools/subprocess_helpers.py

# -*- coding: utf-8 -*-
# Copyright 2019 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Helpers/wrappers for the subprocess module for migration to python3."""

from __future__ import print_function

import subprocess


def CheckCommand(cmd):
  """Executes the command using Popen()."""

  cmd_obj = subprocess.Popen(
      cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, encoding='UTF-8')

  stdout, _ = cmd_obj.communicate()

  if cmd_obj.returncode:
    print(stdout)
    raise subprocess.CalledProcessError(cmd_obj.returncode, cmd)


def check_output(cmd, cwd=None):
  """Wrapper for pre-python3 subprocess.check_output()."""

  return subprocess.check_output(cmd, encoding='UTF-8', cwd=cwd)


def check_call(cmd, cwd=None):
  """Wrapper for pre-python3 subprocess.check_call()."""

  subprocess.check_call(cmd, encoding='UTF-8', cwd=cwd)


# FIXME: CTRL+C does not work when executing a command inside the chroot via
# `cros_sdk`.
def ChrootRunCommand(chroot_path, cmd, verbose=False):
  """Runs the command inside the chroot."""

  exec_chroot_cmd = ['cros_sdk', '--']
  exec_chroot_cmd.extend(cmd)

  return ExecCommandAndCaptureOutput(
      exec_chroot_cmd, cwd=chroot_path, verbose=verbose)


def ExecCommandAndCaptureOutput(cmd, cwd=None, verbose=False):
  """Executes the command and prints to stdout if possible."""

  out = check_output(cmd, cwd=cwd).rstrip()

  if verbose and out:
    print(out)

  return out