#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# Copyright 2010 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.

"""Script to build the ChromeOS toolchain.

This script sets up the toolchain if you give it the gcctools directory.
"""

from __future__ import print_function

__author__ = 'asharif@google.com (Ahmad Sharif)'

import argparse
import getpass
import os
import sys
import tempfile

import tc_enter_chroot
from cros_utils import command_executer
from cros_utils import constants
from cros_utils import misc


class ToolchainPart(object):
  """Class to hold the toolchain pieces."""

  def __init__(self,
               name,
               source_path,
               chromeos_root,
               board,
               incremental,
               build_env,
               gcc_enable_ccache=False):
    self._name = name
    self._source_path = misc.CanonicalizePath(source_path)
    self._chromeos_root = chromeos_root
    self._board = board
    self._ctarget = misc.GetCtargetFromBoard(self._board, self._chromeos_root)
    self._gcc_libs_dest = misc.GetGccLibsDestForBoard(self._board,
                                                      self._chromeos_root)
    self.tag = '%s-%s' % (name, self._ctarget)
    self._ce = command_executer.GetCommandExecuter()
    self._mask_file = os.path.join(
        self._chromeos_root, 'chroot',
        'etc/portage/package.mask/cross-%s' % self._ctarget)
    self._new_mask_file = None

    self._chroot_source_path = os.path.join(constants.MOUNTED_TOOLCHAIN_ROOT,
                                            self._name).lstrip('/')
    self._incremental = incremental
    self._build_env = build_env
    self._gcc_enable_ccache = gcc_enable_ccache

  def RunSetupBoardIfNecessary(self):
    cross_symlink = os.path.join(self._chromeos_root, 'chroot',
                                 'usr/local/bin/emerge-%s' % self._board)
    if not os.path.exists(cross_symlink):
      command = 'setup_board --board=%s' % self._board
      self._ce.ChrootRunCommand(self._chromeos_root, command)

  def Build(self):
    rv = 1
    try:
      self.UninstallTool()
      self.MoveMaskFile()
      self.MountSources(False)
      self.RemoveCompiledFile()
      rv = self.BuildTool()
    finally:
      self.UnMoveMaskFile()
    return rv

  def RemoveCompiledFile(self):
    compiled_file = os.path.join(self._chromeos_root, 'chroot',
                                 'var/tmp/portage/cross-%s' % self._ctarget,
                                 '%s-9999' % self._name, '.compiled')
    command = 'rm -f %s' % compiled_file
    self._ce.RunCommand(command)

  def MountSources(self, unmount_source):
    mount_points = []
    mounted_source_path = os.path.join(self._chromeos_root, 'chroot',
                                       self._chroot_source_path)
    src_mp = tc_enter_chroot.MountPoint(self._source_path, mounted_source_path,
                                        getpass.getuser(), 'ro')
    mount_points.append(src_mp)

    build_suffix = 'build-%s' % self._ctarget
    build_dir = '%s-%s' % (self._source_path, build_suffix)

    if not self._incremental and os.path.exists(build_dir):
      command = 'rm -rf %s/*' % build_dir
      self._ce.RunCommand(command)

    # Create a -build directory for the objects.
    command = 'mkdir -p %s' % build_dir
    self._ce.RunCommand(command)

    mounted_build_dir = os.path.join(
        self._chromeos_root, 'chroot',
        '%s-%s' % (self._chroot_source_path, build_suffix))
    build_mp = tc_enter_chroot.MountPoint(build_dir, mounted_build_dir,
                                          getpass.getuser())
    mount_points.append(build_mp)

    if unmount_source:
      unmount_statuses = [mp.UnMount() == 0 for mp in mount_points]
      assert all(unmount_statuses), 'Could not unmount all mount points!'
    else:
      mount_statuses = [mp.DoMount() == 0 for mp in mount_points]

      if not all(mount_statuses):
        mounted = [
            mp for mp, status in zip(mount_points, mount_statuses) if status
        ]
        unmount_statuses = [mp.UnMount() == 0 for mp in mounted]
        assert all(unmount_statuses), 'Could not unmount all mount points!'

  def UninstallTool(self):
    command = 'sudo CLEAN_DELAY=0 emerge -C cross-%s/%s' % (self._ctarget,
                                                            self._name)
    self._ce.ChrootRunCommand(self._chromeos_root, command)

  def BuildTool(self):
    env = self._build_env
    # FEATURES=buildpkg adds minutes of time so we disable it.
    # TODO(shenhan): keep '-sandbox' for a while for compatibility, then remove
    # it after a while.
    features = ('nostrip userpriv userfetch -usersandbox -sandbox noclean '
                '-buildpkg')
    env['FEATURES'] = features

    if self._incremental:
      env['FEATURES'] += ' keepwork'

    if 'USE' in env:
      env['USE'] += ' multislot mounted_%s' % self._name
    else:
      env['USE'] = 'multislot mounted_%s' % self._name

    # Disable ccache in our compilers. cache may be problematic for us.
    # It ignores compiler environments settings and it is not clear if
    # the cache hit algorithm verifies all the compiler binaries or
    # just the driver.
    if self._name == 'gcc' and not self._gcc_enable_ccache:
      env['USE'] += ' -wrapper_ccache'

    env['%s_SOURCE_PATH' % self._name.upper()] = (
        os.path.join('/', self._chroot_source_path))
    env['ACCEPT_KEYWORDS'] = '~*'
    env_string = ' '.join(['%s="%s"' % var for var in env.items()])
    command = 'emerge =cross-%s/%s-9999' % (self._ctarget, self._name)
    full_command = 'sudo %s %s' % (env_string, command)
    rv = self._ce.ChrootRunCommand(self._chromeos_root, full_command)
    if rv != 0:
      return rv
    if self._name == 'gcc':
      command = ('sudo cp -r /usr/lib/gcc/%s %s' % (self._ctarget,
                                                    self._gcc_libs_dest))
      rv = self._ce.ChrootRunCommand(self._chromeos_root, command)
    return rv

  def MoveMaskFile(self):
    self._new_mask_file = None
    if os.path.isfile(self._mask_file):
      self._new_mask_file = tempfile.mktemp()
      command = 'sudo mv %s %s' % (self._mask_file, self._new_mask_file)
      self._ce.RunCommand(command)

  def UnMoveMaskFile(self):
    if self._new_mask_file:
      command = 'sudo mv %s %s' % (self._new_mask_file, self._mask_file)
      self._ce.RunCommand(command)


def Main(argv):
  """The main function."""
  # Common initializations
  parser = argparse.ArgumentParser()
  parser.add_argument(
      '-c',
      '--chromeos_root',
      dest='chromeos_root',
      default='../../',
      help=('ChromeOS root checkout directory'
            ' uses ../.. if none given.'))
  parser.add_argument(
      '-g',
      '--gcc_dir',
      dest='gcc_dir',
      help='The directory where gcc resides.')
  parser.add_argument(
      '--binutils_dir',
      dest='binutils_dir',
      help='The directory where binutils resides.')
  parser.add_argument(
      '-x',
      '--gdb_dir',
      dest='gdb_dir',
      help='The directory where gdb resides.')
  parser.add_argument(
      '-b',
      '--board',
      dest='board',
      default='x86-alex',
      help='The target board.')
  parser.add_argument(
      '-n',
      '--noincremental',
      dest='noincremental',
      default=False,
      action='store_true',
      help='Use FEATURES=keepwork to do incremental builds.')
  parser.add_argument(
      '--cflags',
      dest='cflags',
      default='',
      help='Build a compiler with specified CFLAGS')
  parser.add_argument(
      '--cxxflags',
      dest='cxxflags',
      default='',
      help='Build a compiler with specified CXXFLAGS')
  parser.add_argument(
      '--cflags_for_target',
      dest='cflags_for_target',
      default='',
      help='Build the target libraries with specified flags')
  parser.add_argument(
      '--cxxflags_for_target',
      dest='cxxflags_for_target',
      default='',
      help='Build the target libraries with specified flags')
  parser.add_argument(
      '--ldflags',
      dest='ldflags',
      default='',
      help='Build a compiler with specified LDFLAGS')
  parser.add_argument(
      '-d',
      '--debug',
      dest='debug',
      default=False,
      action='store_true',
      help='Build a compiler with -g3 -O0 appended to both'
      ' CFLAGS and CXXFLAGS.')
  parser.add_argument(
      '-m',
      '--mount_only',
      dest='mount_only',
      default=False,
      action='store_true',
      help='Just mount the tool directories.')
  parser.add_argument(
      '-u',
      '--unmount_only',
      dest='unmount_only',
      default=False,
      action='store_true',
      help='Just unmount the tool directories.')
  parser.add_argument(
      '--extra_use_flags',
      dest='extra_use_flags',
      default='',
      help='Extra flag for USE, to be passed to the ebuild. '
      "('multislot' and 'mounted_<tool>' are always passed.)")
  parser.add_argument(
      '--gcc_enable_ccache',
      dest='gcc_enable_ccache',
      default=False,
      action='store_true',
      help='Enable ccache for the gcc invocations')

  options = parser.parse_args(argv)

  chromeos_root = misc.CanonicalizePath(options.chromeos_root)
  if options.gcc_dir:
    gcc_dir = misc.CanonicalizePath(options.gcc_dir)
    assert gcc_dir and os.path.isdir(gcc_dir), 'gcc_dir does not exist!'
  if options.binutils_dir:
    binutils_dir = misc.CanonicalizePath(options.binutils_dir)
    assert os.path.isdir(binutils_dir), 'binutils_dir does not exist!'
  if options.gdb_dir:
    gdb_dir = misc.CanonicalizePath(options.gdb_dir)
    assert os.path.isdir(gdb_dir), 'gdb_dir does not exist!'
  if options.unmount_only:
    options.mount_only = False
  elif options.mount_only:
    options.unmount_only = False
  build_env = {}
  if options.cflags:
    build_env['CFLAGS'] = '`portageq envvar CFLAGS` ' + options.cflags
  if options.cxxflags:
    build_env['CXXFLAGS'] = '`portageq envvar CXXFLAGS` ' + options.cxxflags
  if options.cflags_for_target:
    build_env['CFLAGS_FOR_TARGET'] = options.cflags_for_target
  if options.cxxflags_for_target:
    build_env['CXXFLAGS_FOR_TARGET'] = options.cxxflags_for_target
  if options.ldflags:
    build_env['LDFLAGS'] = options.ldflags
  if options.debug:
    debug_flags = '-g3 -O0'
    if 'CFLAGS' in build_env:
      build_env['CFLAGS'] += ' %s' % (debug_flags)
    else:
      build_env['CFLAGS'] = debug_flags
    if 'CXXFLAGS' in build_env:
      build_env['CXXFLAGS'] += ' %s' % (debug_flags)
    else:
      build_env['CXXFLAGS'] = debug_flags
  if options.extra_use_flags:
    build_env['USE'] = options.extra_use_flags

  # Create toolchain parts
  toolchain_parts = {}
  for board in options.board.split(','):
    if options.gcc_dir:
      tp = ToolchainPart('gcc', gcc_dir, chromeos_root, board,
                         not options.noincremental, build_env,
                         options.gcc_enable_ccache)
      toolchain_parts[tp.tag] = tp
      tp.RunSetupBoardIfNecessary()
    if options.binutils_dir:
      tp = ToolchainPart('binutils', binutils_dir, chromeos_root, board,
                         not options.noincremental, build_env)
      toolchain_parts[tp.tag] = tp
      tp.RunSetupBoardIfNecessary()
    if options.gdb_dir:
      tp = ToolchainPart('gdb', gdb_dir, chromeos_root, board,
                         not options.noincremental, build_env)
      toolchain_parts[tp.tag] = tp
      tp.RunSetupBoardIfNecessary()

  rv = 0
  try:
    for tag in toolchain_parts:
      tp = toolchain_parts[tag]
      if options.mount_only or options.unmount_only:
        tp.MountSources(options.unmount_only)
      else:
        rv = rv + tp.Build()
  finally:
    print('Exiting...')
  return rv


if __name__ == '__main__':
  retval = Main(sys.argv[1:])
  sys.exit(retval)