gecko-dev/build/moz.configure/init.configure

# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
# vim: set filetype=python:
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

include('util.configure')
include('checks.configure')

option(env='DIST', nargs=1, help='DIST directory')

# Do not allow objdir == srcdir builds.
# ==============================================================
@depends('--help', 'DIST')
@imports(_from='os.path', _import='exists')
def check_build_environment(help, dist):
    topobjdir = os.path.realpath(os.path.abspath('.'))
    topsrcdir = os.path.realpath(os.path.abspath(
        os.path.join(os.path.dirname(__file__), '..', '..')))

    if dist:
        dist = normsep(dist[0])
    else:
        dist = os.path.join(topobjdir, 'dist')

    result = namespace(
        topsrcdir=topsrcdir,
        topobjdir=topobjdir,
        dist=dist,
    )

    if help:
        return result

    if topsrcdir == topobjdir:
        die('  ***\n'
            '  * Building directly in the main source directory is not allowed.\n'
            '  *\n'
            '  * To build, you must run configure from a separate directory\n'
            '  * (referred to as an object directory).\n'
            '  *\n'
            '  * If you are building with a mozconfig, you will need to change your\n'
            '  * mozconfig to point to a different object directory.\n'
            '  ***'
        )

    # Check for a couple representative files in the source tree
    conflict_files = [
        '*         %s' % f for f in ('Makefile', 'config/autoconf.mk')
        if exists(os.path.join(topsrcdir, f))
    ]
    if conflict_files:
        die('  ***\n'
            '  *   Your source tree contains these files:\n'
            '  %s\n'
            '  *   This indicates that you previously built in the source tree.\n'
            '  *   A source tree build can confuse the separate objdir build.\n'
            '  *\n'
            '  *   To clean up the source tree:\n'
            '  *     1. cd %s\n'
            '  *     2. gmake distclean\n'
            '  ***'
            % ('\n  '.join(conflict_files), topsrcdir)
        )

    return result

set_config('TOPSRCDIR', delayed_getattr(check_build_environment, 'topsrcdir'))
set_config('TOPOBJDIR', delayed_getattr(check_build_environment, 'topobjdir'))
set_config('MOZ_BUILD_ROOT', delayed_getattr(check_build_environment,
                                             'topobjdir'))
set_config('DIST', delayed_getattr(check_build_environment, 'dist'))

add_old_configure_assignment(
    '_topsrcdir', delayed_getattr(check_build_environment, 'topsrcdir'))
add_old_configure_assignment(
    '_objdir', delayed_getattr(check_build_environment, 'topobjdir'))
add_old_configure_assignment(
    'MOZ_BUILD_ROOT', delayed_getattr(check_build_environment, 'topobjdir'))
add_old_configure_assignment(
    'DIST', delayed_getattr(check_build_environment, 'dist'))

option(env='MOZ_AUTOMATION', help='Enable options for automated builds')
set_config('MOZ_AUTOMATION', depends_if('MOZ_AUTOMATION')(lambda x: True))


option(env='OLD_CONFIGURE', nargs=1, help='Path to the old configure script')

option(env='MOZ_CURRENT_PROJECT', nargs=1, help='Current build project')
option(env='MOZCONFIG', nargs=1, help='Mozconfig location')

# Read user mozconfig
# ==============================================================
# Note: the dependency on --help is only there to always read the mozconfig,
# even when --help is passed. Without this dependency, the function wouldn't
# be called when --help is passed, and the mozconfig wouldn't be read.
@depends('MOZ_CURRENT_PROJECT', 'MOZCONFIG', 'OLD_CONFIGURE',
         check_build_environment, '--help')
@imports(_from='mozbuild.mozconfig', _import='MozconfigLoader')
def mozconfig(current_project, mozconfig, old_configure, build_env, help):
    if not old_configure:
        die('The OLD_CONFIGURE environment variable must be set')

    # Don't read the mozconfig for the js configure (yay backwards
    # compatibility)
    # While the long term goal is that js and top-level use the same configure
    # and the same overall setup, including the possibility to use mozconfigs,
    # figuring out what we want to do wrt mozconfig vs. command line and
    # environment variable is not a clear-cut case, and it's more important to
    # fix the immediate problem mozconfig causes to js developers by
    # "temporarily" returning to the previous behavior of not loading the
    # mozconfig for the js configure.
    # Separately to the immediate problem for js developers, there is also the
    # need to not load a mozconfig when running js configure as a subconfigure.
    # Unfortunately, there is no direct way to tell whether the running
    # configure is the js configure. The indirect way is to look at the
    # OLD_CONFIGURE path, which points to js/src/old-configure.
    # I expect we'll have figured things out for mozconfigs well before
    # old-configure dies.
    if os.path.dirname(os.path.abspath(old_configure[0])).endswith('/js/src'):
        return {'path': None}

    loader = MozconfigLoader(build_env.topsrcdir)
    current_project = current_project[0] if current_project else None
    mozconfig = mozconfig[0] if mozconfig else None
    mozconfig = loader.find_mozconfig(env={'MOZCONFIG': mozconfig})
    mozconfig = loader.read_mozconfig(mozconfig, moz_build_app=current_project)

    return mozconfig

set_config('MOZCONFIG', depends(mozconfig)(lambda m: m['path']))


option(env='PYTHON', nargs=1, help='Python interpreter')

# Setup python virtualenv
# ==============================================================
@depends('PYTHON', check_build_environment, mozconfig, '--help')
@imports('os')
@imports('sys')
@imports('subprocess')
@imports(_from='mozbuild.configure.util', _import='LineIO')
@imports(_from='mozbuild.virtualenv', _import='VirtualenvManager')
@imports(_from='mozbuild.virtualenv', _import='verify_python_version')
@imports('distutils.sysconfig')
def virtualenv_python(env_python, build_env, mozconfig, help):
    if help:
        return

    python = env_python[0] if env_python else None

    # Ideally we'd rely on the mozconfig injection from mozconfig_options,
    # but we'd rather avoid the verbosity when we need to reexecute with
    # a different python.
    if mozconfig['path']:
        if 'PYTHON' in mozconfig['env']['added']:
            python = mozconfig['env']['added']['PYTHON']
        elif 'PYTHON' in mozconfig['env']['modified']:
            python = mozconfig['env']['modified']['PYTHON'][1]
        elif 'PYTHON' in mozconfig['vars']['added']:
            python = mozconfig['vars']['added']['PYTHON']
        elif 'PYTHON' in mozconfig['vars']['modified']:
            python = mozconfig['vars']['modified']['PYTHON'][1]

    with LineIO(lambda l: log.error(l)) as out:
        verify_python_version(out)
    topsrcdir, topobjdir = build_env.topsrcdir, build_env.topobjdir
    if topobjdir.endswith('/js/src'):
        topobjdir = topobjdir[:-7]

    with LineIO(lambda l: log.info(l)) as out:
        manager = VirtualenvManager(
            topsrcdir, topobjdir,
            os.path.join(topobjdir, '_virtualenv'), out,
            os.path.join(topsrcdir, 'build', 'virtualenv_packages.txt'))

    if python:
        # If we're not in the virtualenv, we need the which module for
        # find_program.
        if normsep(sys.executable) != normsep(manager.python_path):
            sys.path.append(os.path.join(topsrcdir, 'python', 'which'))
        found_python = find_program(python)
        if not found_python:
            die('The PYTHON environment variable does not contain '
                'a valid path. Cannot find %s', python)
        python = found_python
    else:
        python = sys.executable

    if not manager.up_to_date(python):
        log.info('Creating Python environment')
        manager.build(python)

    python = normsep(manager.python_path)

    if python != normsep(sys.executable):
        log.info('Reexecuting in the virtualenv')
        if env_python:
            del os.environ['PYTHON']
        # One would prefer to use os.execl, but that's completely borked on
        # Windows.
        sys.exit(subprocess.call([python] + sys.argv))

    # We are now in the virtualenv
    if not distutils.sysconfig.get_python_lib():
        die('Could not determine python site packages directory')

    return python

set_config('PYTHON', virtualenv_python)
add_old_configure_assignment('PYTHON', virtualenv_python)

# Inject mozconfig options
# ==============================================================
# All options defined above this point can't be injected in mozconfig_options
# below, so collect them.
@template
def early_options():
    @dependable
    @imports('__sandbox__')
    def early_options():
        return set(
            option.env
            for option in __sandbox__._options.itervalues()
            if option.env
        )
    return early_options

early_options = early_options()

@depends(mozconfig, '--help')
# This gives access to the sandbox. Don't copy this blindly.
@imports('__sandbox__')
@imports('os')
def mozconfig_options(mozconfig, help):
    if mozconfig['path']:
        helper = __sandbox__._helper
        log.info('Adding configure options from %s' % mozconfig['path'])
        for arg in mozconfig['configure_args']:
            log.info('  %s' % arg)
            # We could be using imply_option() here, but it has other
            # contraints that don't really apply to the command-line
            # emulation that mozconfig provides.
            helper.add(arg, origin='mozconfig', args=helper._args)

        def add(key, value):
            if key.isupper():
                arg = '%s=%s' % (key, value)
                log.info('  %s' % arg)
                helper.add(arg, origin='mozconfig', args=helper._args)

        for key, value in mozconfig['env']['added'].iteritems():
            add(key, value)
            os.environ[key] = value
        for key, (_, value) in mozconfig['env']['modified'].iteritems():
            add(key, value)
            os.environ[key] = value
        for key, value in mozconfig['vars']['added'].iteritems():
            # mozconfig_loader adds _IS_SET variables that are irrelevant
            if not key.endswith('_IS_SET'):
                add(key, value)
        for key, (_, value) in mozconfig['vars']['modified'].iteritems():
            add(key, value)


# Mozilla-Build
# ==============================================================
option(env='MOZILLABUILD', nargs=1,
       help='Path to Mozilla Build (Windows-only)')

option(env='CONFIG_SHELL', nargs=1, help='Path to a POSIX shell')

# It feels dirty replicating this from python/mozbuild/mozbuild/mozconfig.py,
# but the end goal being that the configure script would go away...
@depends('CONFIG_SHELL', 'MOZILLABUILD')
@checking('for a shell')
@imports('sys')
def shell(value, mozillabuild):
    if value:
        return find_program(value[0])
    shell = 'sh'
    if mozillabuild:
        shell = mozillabuild[0] + '/msys/bin/sh'
    if sys.platform == 'win32':
        shell = shell + '.exe'
    return find_program(shell)


# Host and target systems
# ==============================================================
option('--host', nargs=1, help='Define the system type performing the build')

option('--target', nargs=1,
       help='Define the system type where the resulting executables will be '
            'used')

@imports(_from='mozbuild.configure.constants', _import='CPU')
@imports(_from='mozbuild.configure.constants', _import='CPU_bitness')
@imports(_from='mozbuild.configure.constants', _import='Endianness')
@imports(_from='mozbuild.configure.constants', _import='Kernel')
@imports(_from='mozbuild.configure.constants', _import='OS')
def split_triplet(triplet):
    # The standard triplet is defined as
    #   CPU_TYPE-MANUFACTURER-OPERATING_SYSTEM
    # There is also a quartet form:
    #   CPU_TYPE-MANUFACTURER-KERNEL-OPERATING_SYSTEM
    # But we can consider the "KERNEL-OPERATING_SYSTEM" as one.
    cpu, manufacturer, os = triplet.split('-', 2)

    # Autoconf uses config.sub to validate and canonicalize those triplets,
    # but the granularity of its results has never been satisfying to our
    # use, so we've had our own, different, canonicalization. We've also
    # historically not been very consistent with how we use the canonicalized
    # values. Hopefully, this will help us make things better.
    # The tests are inherited from our decades-old autoconf-based configure,
    # which can probably be improved/cleaned up because they are based on a
    # mix of uname and config.guess output, while we now only use the latter,
    # which presumably has a cleaner and leaner output. Let's refine later.
    os = os.replace('/', '_')
    if 'android' in os:
        canonical_os = 'Android'
        canonical_kernel = 'Linux'
    elif os.startswith('linux'):
        canonical_os = 'GNU'
        canonical_kernel = 'Linux'
    elif os.startswith('kfreebsd') and os.endswith('-gnu'):
        canonical_os = 'GNU'
        canonical_kernel = 'kFreeBSD'
    elif os.startswith('gnu'):
        canonical_os = canonical_kernel = 'GNU'
    elif os.startswith('mingw'):
        canonical_os = canonical_kernel = 'WINNT'
    elif os.startswith('darwin'):
        canonical_kernel = 'Darwin'
        canonical_os = 'OSX'
    elif os.startswith('ios'):
        canonical_kernel = 'Darwin'
        canonical_os = 'iOS'
    elif os.startswith('dragonfly'):
        canonical_os = canonical_kernel = 'DragonFly'
    elif os.startswith('freebsd'):
        canonical_os = canonical_kernel = 'FreeBSD'
    elif os.startswith('netbsd'):
        canonical_os = canonical_kernel = 'NetBSD'
    elif os.startswith('openbsd'):
        canonical_os = canonical_kernel = 'OpenBSD'
    else:
        die('Unknown OS: %s' % os)

    # The CPU granularity is probably not enough. Moving more things from
    # old-configure will tell us if we need more
    if cpu.endswith('86') or (cpu.startswith('i') and '86' in cpu):
        canonical_cpu = 'x86'
        endianness = 'little'
    elif cpu in ('x86_64', 'ia64'):
        canonical_cpu = cpu
        endianness = 'little'
    elif cpu in ('s390', 's390x'):
        canonical_cpu = cpu
        endianness = 'big'
    elif cpu in ('powerpc64', 'ppc64', 'powerpc64le', 'ppc64le'):
        canonical_cpu = 'ppc64'
        endianness = 'little' if 'le' in cpu else 'big'
    elif cpu in ('powerpc', 'ppc', 'rs6000') or cpu.startswith('powerpc'):
        canonical_cpu = 'ppc'
        endianness = 'big'
    elif cpu in ('Alpha', 'alpha', 'ALPHA'):
        canonical_cpu = 'Alpha'
        endianness = 'little'
    elif cpu.startswith('hppa') or cpu == 'parisc':
        canonical_cpu = 'hppa'
        endianness = 'big'
    elif cpu.startswith('sparc64'):
        canonical_cpu = 'sparc64'
        endianness = 'big'
    elif cpu.startswith('sparc') or cpu == 'sun4u':
        canonical_cpu = 'sparc'
        endianness = 'big'
    elif cpu.startswith('arm'):
        canonical_cpu = 'arm'
        endianness = 'big' if cpu.startswith(('armeb', 'armbe')) else 'little'
    elif cpu in ('mips', 'mipsel'):
        canonical_cpu = 'mips32'
        endianness = 'little' if 'el' in cpu else 'big'
    elif cpu in ('mips64', 'mips64el'):
        canonical_cpu = 'mips64'
        endianness = 'little' if 'el' in cpu else 'big'
    elif cpu.startswith('aarch64'):
        canonical_cpu = 'aarch64'
        endianness = 'little'
    else:
        die('Unknown CPU type: %s' % cpu)

    return namespace(
        alias=triplet,
        cpu=CPU(canonical_cpu),
        bitness=CPU_bitness[canonical_cpu],
        kernel=Kernel(canonical_kernel),
        os=OS(canonical_os),
        endianness=Endianness(endianness),
        raw_cpu=cpu,
        raw_os=os,
        # Toolchains, most notably for cross compilation may use cpu-os
        # prefixes.
        toolchain='%s-%s' % (cpu, os),
    )


@imports('subprocess')
def config_sub(shell, triplet):
    config_sub = os.path.join(os.path.dirname(__file__), '..',
                              'autoconf', 'config.sub')
    return subprocess.check_output([shell, config_sub, triplet]).strip()


@depends('--host', shell)
@checking('for host system type', lambda h: h.alias)
@imports('subprocess')
def host(value, shell):
    if not value:
        config_guess = os.path.join(os.path.dirname(__file__), '..',
                                    'autoconf', 'config.guess')
        host = subprocess.check_output([shell, config_guess]).strip()
    else:
        host = value[0]

    return split_triplet(config_sub(shell, host))


@depends('--target', host, shell)
@checking('for target system type', lambda t: t.alias)
def target(value, host, shell):
    if not value:
        return host
    return split_triplet(config_sub(shell, value[0]))


@depends(host, target)
@checking('whether cross compiling')
def cross_compiling(host, target):
    return host != target

set_config('CROSS_COMPILE', cross_compiling)
set_define('CROSS_COMPILE', cross_compiling)
add_old_configure_assignment('CROSS_COMPILE', cross_compiling)


@depends(target)
def have_64_bit(target):
    if target.bitness == 64:
        return True

set_config('HAVE_64BIT_BUILD', have_64_bit)
set_define('HAVE_64BIT_BUILD', have_64_bit)
add_old_configure_assignment('HAVE_64BIT_BUILD', have_64_bit)


# Autoconf needs these set
@depends(host)
def host_for_old_configure(host):
    return '--host=%s' % host.alias

add_old_configure_arg(host_for_old_configure)

@depends(target)
def target_for_old_configure(target):
    target_alias = target.alias
    # old-configure does plenty of tests against $target and $target_os
    # and expects darwin for iOS, so make it happy.
    if target.os == 'iOS':
        target_alias = target_alias.replace('-ios', '-darwin')
    return '--target=%s' % target_alias

add_old_configure_arg(target_for_old_configure)


# These variables are for compatibility with the current moz.builds and
# old-configure. Eventually, we'll want to canonicalize better.
@depends(target)
def target_variables(target):
    if target.kernel == 'kFreeBSD':
        os_target = 'GNU/kFreeBSD'
        os_arch = 'GNU_kFreeBSD'
    elif target.kernel == 'Darwin' or (target.kernel == 'Linux' and
                                       target.os == 'GNU'):
        os_target = target.kernel
        os_arch = target.kernel
    else:
        os_target = target.os
        os_arch = target.kernel

    if target.kernel == 'Darwin' and target.cpu == 'x86':
        os_test = 'i386'
    else:
        os_test = target.raw_cpu

    return namespace(
        OS_TARGET=os_target,
        OS_ARCH=os_arch,
        OS_TEST=os_test,
        INTEL_ARCHITECTURE=target.cpu in ('x86', 'x86_64') or None,
    )

set_config('OS_TARGET', delayed_getattr(target_variables, 'OS_TARGET'))
add_old_configure_assignment('OS_TARGET',
                             delayed_getattr(target_variables, 'OS_TARGET'))
set_config('OS_ARCH', delayed_getattr(target_variables, 'OS_ARCH'))
add_old_configure_assignment('OS_ARCH',
                             delayed_getattr(target_variables, 'OS_ARCH'))
set_config('OS_TEST', delayed_getattr(target_variables, 'OS_TEST'))
add_old_configure_assignment('OS_TEST',
                             delayed_getattr(target_variables, 'OS_TEST'))
set_config('CPU_ARCH', delayed_getattr(target, 'cpu'))
add_old_configure_assignment('CPU_ARCH', delayed_getattr(target, 'cpu'))
set_config('INTEL_ARCHITECTURE', delayed_getattr(target_variables,
                                                 'INTEL_ARCHITECTURE'))
set_config('TARGET_CPU', delayed_getattr(target, 'raw_cpu'))
set_config('TARGET_OS', delayed_getattr(target, 'raw_os'))


@depends(host)
def host_variables(host):
    if host.kernel == 'kFreeBSD':
        os_arch = 'GNU_kFreeBSD'
    else:
        os_arch = host.kernel
    return namespace(
        HOST_OS_ARCH=os_arch,
    )

set_config('HOST_CPU_ARCH', delayed_getattr(host, 'cpu'))
set_config('HOST_OS_ARCH', delayed_getattr(host_variables, 'HOST_OS_ARCH'))
add_old_configure_assignment('HOST_OS_ARCH',
                             delayed_getattr(host_variables, 'HOST_OS_ARCH'))

@depends(target)
def target_is_windows(target):
    if target.kernel == 'WINNT':
        return True

set_define('_WINDOWS', target_is_windows)
set_define('WIN32', target_is_windows)
set_define('XP_WIN', target_is_windows)
set_define('XP_WIN32', target_is_windows)

@depends(target)
def target_is_unix(target):
    if target.kernel != 'WINNT':
        return True

set_define('XP_UNIX', target_is_unix)

@depends(target)
def target_is_darwin(target):
    if target.kernel == 'Darwin':
        return True

set_define('XP_DARWIN', target_is_darwin)

@depends(target)
def target_is_ios(target):
    if target.kernel == 'Darwin' and target.os == 'iOS':
        return True

set_define('XP_IOS', target_is_ios)

@depends(target)
def target_is_osx(target):
    if target.kernel == 'Darwin' and target.os == 'OSX':
        return True

set_define('XP_MACOSX', target_is_osx)

@depends(target)
def target_is_linux(target):
    if target.kernel == 'Linux':
        return True

set_define('XP_LINUX', target_is_linux)

# The application/project to build
# ==============================================================
option('--enable-application', nargs=1, env='MOZ_BUILD_APP',
       help='Application to build. Same as --enable-project.')

@depends('--enable-application', '--help')
def application(app, help):
    if app:
        return app

imply_option('--enable-project', application)


@depends(check_build_environment, '--help')
def default_project(build_env, help):
    if build_env.topobjdir.endswith('/js/src'):
        return 'js'
    return 'browser'

option('--enable-project', nargs=1, default=default_project,
       help='Project to build')

option('--with-external-source-dir', env='EXTERNAL_SOURCE_DIR', nargs=1,
       help='External directory containing additional build files')

@depends('--enable-project', '--with-external-source-dir',
         check_build_environment, '--help')
@imports(_from='os.path', _import='exists')
def include_project_configure(project, external_source_dir, build_env, help):
    if not project:
        die('--enable-project is required.')

    base_dir = build_env.topsrcdir
    if external_source_dir:
        base_dir = os.path.join(base_dir, external_source_dir[0])

    path = os.path.join(base_dir, project[0], 'moz.configure')
    if not exists(path):
        die('Cannot find project %s', project[0])
    return path

@depends('--with-external-source-dir')
def external_source_dir(value):
    if value:
        return value[0]

set_config('EXTERNAL_SOURCE_DIR', external_source_dir)
add_old_configure_assignment('EXTERNAL_SOURCE_DIR', external_source_dir)


@depends(include_project_configure, check_build_environment, '--help')
def build_project(include_project_configure, build_env, help):
    ret = os.path.dirname(os.path.relpath(include_project_configure,
                                          build_env.topsrcdir))
    return ret

set_config('MOZ_BUILD_APP', build_project)
set_define('MOZ_BUILD_APP', build_project)
add_old_configure_assignment('MOZ_BUILD_APP', build_project)


# set RELEASE_OR_BETA and NIGHTLY_BUILD variables depending on the cycle we're in
# The logic works like this:
# - if we have "a1" in GRE_MILESTONE, we're building Nightly (define NIGHTLY_BUILD)
# - otherwise, if we have "a" in GRE_MILESTONE, we're building Nightly or Aurora
# - otherwise, we're building Release/Beta (define RELEASE_OR_BETA)
@depends(check_build_environment, '--help')
@imports(_from='__builtin__', _import='open')
def milestone(build_env, _):
    milestone_path = os.path.join(build_env.topsrcdir,
                                  'config',
                                  'milestone.txt')
    with open(milestone_path, 'r') as fh:
        milestone = fh.read().splitlines()[-1]

    is_nightly = is_release_or_beta = None

    if 'a1' in milestone:
        is_nightly = True
    elif 'a' not in milestone:
        is_release_or_beta = True

    return namespace(version=milestone,
                     is_nightly=is_nightly,
                     is_release_or_beta=is_release_or_beta)

set_config('GRE_MILESTONE', delayed_getattr(milestone, 'version'))
set_config('NIGHTLY_BUILD', delayed_getattr(milestone, 'is_nightly'))
set_define('NIGHTLY_BUILD', delayed_getattr(milestone, 'is_nightly'))
add_old_configure_assignment('NIGHTLY_BUILD',
                             delayed_getattr(milestone, 'is_nightly'))
set_config('RELEASE_OR_BETA', delayed_getattr(milestone, 'is_release_or_beta'))
set_define('RELEASE_OR_BETA', delayed_getattr(milestone, 'is_release_or_beta'))
add_old_configure_assignment('RELEASE_OR_BETA',
                             delayed_getattr(milestone, 'is_release_or_beta'))

# The app update channel is 'default' when not supplied. The value is used in
# the application's confvars.sh (and is made available to a project specific
# moz.configure).
option('--enable-update-channel',
       nargs=1,
       help='Select application update channel',
       default='default')

@depends('--enable-update-channel')
def update_channel(channel):
    if channel[0] == '':
        return 'default'
    return channel[0].lower()

set_config('MOZ_UPDATE_CHANNEL', update_channel)
set_define('MOZ_UPDATE_CHANNEL', update_channel)
add_old_configure_assignment('MOZ_UPDATE_CHANNEL', update_channel)


# A template providing a shorthand for setting a variable. The created
# option will only be settable with imply_option.
# It is expected that a project-specific moz.configure will call imply_option
# to set a value other than the default.
# If required, the set_as_define and set_for_old_configure arguments
# will additionally cause the variable to be set using set_define and
# add_old_configure_assignment. util.configure would be an appropriate place for
# this, but it uses add_old_configure_assignment, which is defined in this file.
@template
def project_flag(env=None, set_for_old_configure=False,
                 set_as_define=False, **kwargs):

    if not env:
        configure_error("A project_flag must be passed a variable name to set.")

    opt = option(env=env, possible_origins=('implied',), **kwargs)

    @depends(opt.option)
    def option_implementation(value):
        if value:
            if len(value):
                return value
            return bool(value)

    set_config(env, option_implementation)
    if set_as_define:
        set_define(env, option_implementation)
    if set_for_old_configure:
        add_old_configure_assignment(env, option_implementation)

# milestone.is_nightly corresponds to cases NIGHTLY_BUILD is set.
@depends(milestone, '--help')
def enabled_in_nightly(milestone, _):
    return milestone.is_nightly

# Set the MOZ_CONFIGURE_OPTIONS variable with all the options that
# were passed somehow (environment, command line, mozconfig)
@dependable
@imports(_from='mozbuild.shellutil', _import='quote')
@imports('__sandbox__')
def all_configure_options():
    result = []
    previous = None
    for option in __sandbox__._options.itervalues():
        # __sandbox__._options contains items for both option.name and
        # option.env. But it's also an OrderedDict, meaning both are
        # consecutive.
        # Also ignore OLD_CONFIGURE and MOZCONFIG because they're not
        # interesting.
        if option == previous or option.env in ('OLD_CONFIGURE', 'MOZCONFIG'):
            continue
        previous = option
        value = __sandbox__._value_for(option)
        # We only want options that were explicitly given on the command
        # line, the environment, or mozconfig, and that differ from the
        # defaults.
        if (value is not None and value.origin not in ('default', 'implied') and
                value != option.default):
            result.append(__sandbox__._raw_options[option])
        # We however always include options that are sent to old configure
        # because we don't know their actual defaults. (Keep the conditions
        # separate for ease of understanding and ease of removal)
        elif (option.help == 'Help missing for old configure options' and
                option in __sandbox__._raw_options):
            result.append(__sandbox__._raw_options[option])

    return quote(*result)

set_config('MOZ_CONFIGURE_OPTIONS', all_configure_options)


# This is temporary until js/src/configure and configure are merged.
# Use instead of option() in js/moz.configure and more generally, for
# options that are shared between configure and js/src/configure.
@template
def js_option(*args, **kwargs):
    opt = option(*args, **kwargs)

    @depends(opt.option, build_project)
    def js_option(value, build_project):
        if build_project != 'js':
            return value.format(opt.option)

    add_old_configure_arg(js_option)


# Bug 1278542: This function is a workaround to resolve
# |android_ndk_include|'s dependency on 'gonkdir.' The
# actual implementation is located in b2g/moz.configure.
# Remove this function as soon as 'android_ndk_include'
# depends on 'target.'
@depends('--help')
def gonkdir(_):
    return None