#!/usr/bin/env python
#
# Copyright (C) 2015 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""Builds the Android Clang toolchain."""
import argparse
import glob
import logging
import multiprocessing
import os
import pprint
import subprocess
import sys
import version
# Disable all the "too many/few methods/parameters" warnings and the like.
# pylint: disable=design
# Disable lint warnings for todo comments and the like.
# pylint: disable=fixme
# TODO: Add docstrings?
# pylint: disable=missing-docstring
THIS_DIR = os.path.realpath(os.path.dirname(__file__))
ORIG_ENV = dict(os.environ)
class Config(object):
"""Container for global configuration options."""
# Set True to skip all actions (log only). Controlled by --dry-run.
dry_run = False
def logger():
"""Returns the default logger for the module."""
return logging.getLogger(__name__)
def android_path(*args):
return os.path.realpath(os.path.join(THIS_DIR, '../..', *args))
def build_path(*args):
# Our multistage build directories will be placed under OUT_DIR if it is in
# the environment. By default they will be placed under
# $ANDROID_BUILD_TOP/out.
top_out = ORIG_ENV.get('OUT_DIR', 'out')
return os.path.join(top_out, *args)
def short_version():
return '.'.join([version.major, version.minor])
def long_version():
return '.'.join([version.major, version.minor, version.patch])
def check_call(cmd, *args, **kwargs):
"""Proxy for subprocess.check_call with logging and dry-run support."""
import subprocess
logger().info('check_call: %s', ' '.join(cmd))
if 'env' in kwargs:
# Rather than dump the whole environment to the terminal every time,
# just print the difference between this call and our environment.
# Note that this will not include environment that was *removed* from
# os.environ.
extra_env = dict(set(kwargs['env'].items()) - set(os.environ.items()))
if len(extra_env) > 0:
logger().info('check_call additional env:\n%s',
pprint.pformat(extra_env))
if not Config.dry_run:
subprocess.check_call(cmd, *args, **kwargs)
def install_file(src, dst):
"""Proxy for shutil.copy2 with logging and dry-run support."""
import shutil
logger().info('copy %s %s', src, dst)
if not Config.dry_run:
shutil.copy2(src, dst)
def install_directory(src, dst):
"""Proxy for shutil.copytree with logging and dry-run support."""
import shutil
logger().info('copytree %s %s', src, dst)
if not Config.dry_run:
shutil.copytree(src, dst)
def rmtree(path):
"""Proxy for shutil.rmtree with logging and dry-run support."""
import shutil
logger().info('rmtree %s', path)
if not Config.dry_run:
shutil.rmtree(path)
def rename(src, dst):
"""Proxy for os.rename with logging and dry-run support."""
logger().info('rename %s %s', src, dst)
if not Config.dry_run:
os.rename(src, dst)
def makedirs(path):
"""Proxy for os.makedirs with logging and dry-run support."""
logger().info('makedirs %s', path)
if not Config.dry_run:
os.makedirs(path)
def symlink(src, dst):
"""Proxy for os.symlink with logging and dry-run support."""
logger().info('symlink %s %s', src, dst)
if not Config.dry_run:
os.symlink(src, dst)
def build(out_dir, prebuilts_path=None, prebuilts_version=None,
build_all_clang_tools=None, build_all_llvm_tools=None,
debug_clang=None, max_jobs=multiprocessing.cpu_count()):
products = (
'aosp_arm',
'aosp_arm64',
'aosp_mips',
'aosp_mips64',
'aosp_x86',
'aosp_x86_64',
)
for product in products:
build_product(out_dir, product, prebuilts_path, prebuilts_version,
build_all_clang_tools, build_all_llvm_tools, debug_clang,
max_jobs)
def build_product(out_dir, product, prebuilts_path, prebuilts_version,
build_all_clang_tools, build_all_llvm_tools, debug_clang,
max_jobs):
env = dict(ORIG_ENV)
env['DISABLE_LLVM_DEVICE_BUILDS'] = 'true'
env['DISABLE_RELOCATION_PACKER'] = 'true'
env['FORCE_BUILD_LLVM_COMPONENTS'] = 'true'
env['FORCE_BUILD_SANITIZER_SHARED_OBJECTS'] = 'true'
env['OUT_DIR'] = out_dir
env['SKIP_LLVM_TESTS'] = 'true'
env['SOONG_ALLOW_MISSING_DEPENDENCIES'] = 'true'
env['TARGET_BUILD_VARIANT'] = 'userdebug'
env['TARGET_PRODUCT'] = product
if debug_clang:
env['FORCE_BUILD_LLVM_DEBUG'] = 'true'
env['FORCE_BUILD_LLVM_DISABLE_NDEBUG'] = 'true'
overrides = []
if prebuilts_path is not None:
overrides.append('LLVM_PREBUILTS_BASE={}'.format(prebuilts_path))
if prebuilts_version is not None:
overrides.append('LLVM_PREBUILTS_VERSION={}'.format(prebuilts_version))
# Use at least 1 and at most all available CPUs (sanitize the user input).
jobs_arg = '-j{}'.format(
max(1, min(max_jobs, multiprocessing.cpu_count())))
targets = ['clang-toolchain-minimal']
if build_all_clang_tools:
targets += ['clang-toolchain-full']
if build_all_llvm_tools:
targets += ['llvm-tools']
check_call(['make', jobs_arg] + overrides + targets,
cwd=android_path(), env=env)
def package_toolchain(build_dir, build_name, host, dist_dir):
package_name = 'clang-' + build_name
install_host_dir = build_path('install', host)
install_dir = os.path.join(install_host_dir, package_name)
# Remove any previously installed toolchain so it doesn't pollute the
# build.
if os.path.exists(install_host_dir):
rmtree(install_host_dir)
install_toolchain(build_dir, install_dir, host, True)
version_file_path = os.path.join(install_dir, 'AndroidVersion.txt')
with open(version_file_path, 'w') as version_file:
version_file.write('{}.{}.{}\n'.format(
version.major, version.minor, version.patch))
tarball_name = package_name + '-' + host
package_path = os.path.join(dist_dir, tarball_name) + '.tar.bz2'
logger().info('Packaging %s', package_path)
args = [
'tar', '-cjC', install_host_dir, '-f', package_path, package_name
]
check_call(args)
def install_minimal_toolchain(build_dir, install_dir, host, strip):
install_built_host_files(build_dir, install_dir, host, strip, minimal=True)
install_headers(build_dir, install_dir, host)
install_sanitizers(build_dir, install_dir, host)
def install_toolchain(build_dir, install_dir, host, strip):
install_built_host_files(build_dir, install_dir, host, strip)
install_compiler_wrapper(install_dir, host)
install_sanitizer_scripts(install_dir)
install_scan_scripts(install_dir)
install_analyzer_scripts(install_dir)
install_headers(build_dir, install_dir, host)
install_profile_rt(build_dir, install_dir, host)
install_sanitizers(build_dir, install_dir, host)
install_sanitizer_tests(build_dir, install_dir, host)
install_libomp(build_dir, install_dir, host)
install_license_files(install_dir)
install_repo_prop(install_dir)
def get_built_host_files(host, minimal):
is_windows = host.startswith('windows')
is_darwin = host.startswith('darwin-x86')
bin_ext = '.exe' if is_windows else ''
if is_windows:
lib_ext = '.dll'
elif is_darwin:
lib_ext = '.dylib'
else:
lib_ext = '.so'
built_files = [
'bin/clang' + bin_ext,
'bin/clang++' + bin_ext,
]
if not is_windows:
built_files.extend(['lib64/libc++' + lib_ext])
if minimal:
return built_files
built_files.extend([
'bin/clang-format' + bin_ext,
'bin/clang-tidy' + bin_ext,
])
if is_windows:
built_files.extend([
'bin/clang_32' + bin_ext,
])
else:
built_files.extend([
'bin/FileCheck' + bin_ext,
'bin/llvm-as' + bin_ext,
'bin/llvm-dis' + bin_ext,
'bin/llvm-link' + bin_ext,
'bin/llvm-symbolizer' + bin_ext,
'lib64/libLLVM' + lib_ext,
'lib64/LLVMgold' + lib_ext,
])
return built_files
def install_built_host_files(build_dir, install_dir, host, strip, minimal=None):
built_files = get_built_host_files(host, minimal)
for built_file in built_files:
dirname = os.path.dirname(built_file)
install_path = os.path.join(install_dir, dirname)
if not os.path.exists(install_path):
makedirs(install_path)
built_path = os.path.join(build_dir, 'host', host, built_file)
install_file(built_path, install_path)
file_name = os.path.basename(built_file)
# Only strip bin files (not libs) on darwin.
is_darwin = host.startswith('darwin-x86')
if strip and (not is_darwin or built_file.startswith('bin/')):
check_call(['strip', os.path.join(install_path, file_name)])
def install_sanitizer_scripts(install_dir):
script_path = android_path(
'external/compiler-rt/lib/asan/scripts/asan_device_setup')
install_file(script_path, os.path.join(install_dir, 'bin'))
def install_analyzer_scripts(install_dir):
"""Create and install bash scripts for invoking Clang for analysis."""
analyzer_text = (
'#!/bin/bash\n'
'if [ "$1" != "-cc1" ]; then\n'
' `dirname $0`/../clang{clang_suffix} -target {target} "$@"\n'
'else\n'
' # target/triple already spelled out.\n'
' `dirname $0`/../clang{clang_suffix} "$@"\n'
'fi\n'
)
arch_target_pairs = (
('arm64-v8a', 'aarch64-none-linux-android'),
('armeabi', 'armv5te-none-linux-androideabi'),
('armeabi-v7a', 'armv7-none-linux-androideabi'),
('armeabi-v7a-hard', 'armv7-none-linux-androideabi'),
('mips', 'mipsel-none-linux-android'),
('mips64', 'mips64el-none-linux-android'),
('x86', 'i686-none-linux-android'),
('x86_64', 'x86_64-none-linux-android'),
)
for arch, target in arch_target_pairs:
arch_path = os.path.join(install_dir, 'bin', arch)
makedirs(arch_path)
analyzer_file_path = os.path.join(arch_path, 'analyzer')
logger().info('Creating %s', analyzer_file_path)
with open(analyzer_file_path, 'w') as analyzer_file:
analyzer_file.write(
analyzer_text.format(clang_suffix='', target=target))
subprocess.check_call(['chmod', 'a+x', analyzer_file_path])
analyzerpp_file_path = os.path.join(arch_path, 'analyzer++')
logger().info('Creating %s', analyzerpp_file_path)
with open(analyzerpp_file_path, 'w') as analyzerpp_file:
analyzerpp_file.write(
analyzer_text.format(clang_suffix='++', target=target))
subprocess.check_call(['chmod', 'a+x', analyzerpp_file_path])
def install_scan_scripts(install_dir):
tools_install_dir = os.path.join(install_dir, 'tools')
makedirs(tools_install_dir)
tools = ('scan-build', 'scan-view')
tools_dir = android_path('external/clang/tools')
for tool in tools:
tool_path = os.path.join(tools_dir, tool)
install_path = os.path.join(install_dir, 'tools', tool)
install_directory(tool_path, install_path)
def install_headers(build_dir, install_dir, host):
def should_copy(path):
if os.path.basename(path) in ('Makefile', 'CMakeLists.txt'):
return False
_, ext = os.path.splitext(path)
if ext == '.mk':
return False
return True
headers_src = android_path('external/clang/lib/Headers')
headers_dst = os.path.join(
install_dir, 'lib64/clang', short_version(), 'include')
makedirs(headers_dst)
for header in os.listdir(headers_src):
if not should_copy(header):
continue
install_file(os.path.join(headers_src, header), headers_dst)
install_file(android_path('bionic/libc/include/stdatomic.h'), headers_dst)
# arm_neon.h gets produced as part of external/clang/Android.bp.
# We must bundle the resulting file as part of the official Clang headers.
arm_neon_h = os.path.join(
build_dir, 'soong/.intermediates/external/clang/clang-gen-arm-neon/gen/clang/Basic/arm_neon.h')
install_file(arm_neon_h, headers_dst)
symlink(short_version(),
os.path.join(install_dir, 'lib64/clang', long_version()))
def install_profile_rt(build_dir, install_dir, host):
lib_dir = os.path.join(
install_dir, 'lib64/clang', short_version(), 'lib/linux')
makedirs(lib_dir)
install_target_profile_rt(build_dir, lib_dir)
# We only support profiling libs for Linux and Android.
if host == 'linux-x86':
install_host_profile_rt(build_dir, host, lib_dir)
def install_target_profile_rt(build_dir, lib_dir):
product_to_arch = {
'generic': 'arm',
'generic_arm64': 'aarch64',
'generic_mips': 'mipsel',
'generic_mips64': 'mips64el',
'generic_x86': 'i686',
'generic_x86_64': 'x86_64',
}
for product, arch in product_to_arch.items():
product_dir = os.path.join(build_dir, 'target/product', product)
static_libs = os.path.join(product_dir, 'obj/STATIC_LIBRARIES')
built_lib = os.path.join(
static_libs, 'libprofile_rt_intermediates/libprofile_rt.a')
lib_name = 'libclang_rt.profile-{}-android.a'.format(arch)
install_file(built_lib, os.path.join(lib_dir, lib_name))
def install_host_profile_rt(build_dir, host, lib_dir):
arch_to_obj_dir = {
'i686': 'obj32',
'x86_64': 'obj',
}
for arch, obj_dir in arch_to_obj_dir.items():
static_libs = os.path.join(
build_dir, 'host', host, obj_dir, 'STATIC_LIBRARIES')
built_lib = os.path.join(
static_libs, 'libprofile_rt_intermediates/libprofile_rt.a')
lib_name = 'libclang_rt.profile-{}.a'.format(arch)
install_file(built_lib, os.path.join(lib_dir, lib_name))
def install_libomp(build_dir, install_dir, host):
# libomp is not built for Darwin
if host == 'darwin-x86':
return
lib_dir = os.path.join(
install_dir, 'lib64/clang', short_version(), 'lib/linux')
if not os.path.isdir(lib_dir):
makedirs(lib_dir)
product_to_arch = {
'generic': 'arm',
'generic_arm64': 'arm64',
'generic_x86': 'x86',
'generic_x86_64': 'x86_64',
}
for product, arch in product_to_arch.items():
module = 'libomp-' + arch
product_dir = os.path.join(build_dir, 'target/product', product)
shared_libs = os.path.join(product_dir, 'obj/SHARED_LIBRARIES')
built_lib = os.path.join(
shared_libs,
'{}_intermediates/PACKED/{}.so'.format(module, module))
install_file(built_lib, os.path.join(lib_dir, module + '.so'))
def install_sanitizers(build_dir, install_dir, host):
headers_src = android_path('external/compiler-rt/include/sanitizer')
clang_lib = os.path.join(install_dir, 'lib64/clang', short_version())
headers_dst = os.path.join(clang_lib, 'include/sanitizer')
lib_dst = os.path.join(clang_lib, 'lib/linux')
install_directory(headers_src, headers_dst)
if not os.path.exists(lib_dst):
makedirs(lib_dst)
if host == 'linux-x86':
install_host_sanitizers(build_dir, host, lib_dst)
# Tuples of (product, arch)
product_to_arch = (
('generic', 'arm'),
('generic_arm64', 'aarch64'),
('generic_x86', 'i686'),
('generic_mips', 'mips'),
('generic_mips64', 'mips64'),
)
sanitizers = ('asan', 'ubsan_standalone')
for product, arch in product_to_arch:
for sanitizer in sanitizers:
module = 'libclang_rt.{}-{}-android'.format(sanitizer, arch)
product_dir = os.path.join(build_dir, 'target/product', product)
lib_dir = os.path.join(product_dir, 'obj/SHARED_LIBRARIES',
'{}_intermediates'.format(module))
lib_name = '{}.so'.format(module)
built_lib = os.path.join(lib_dir, 'PACKED', lib_name)
install_file(built_lib, lib_dst)
# Also install the asan_test binaries. We need to do this because the
# platform sources for compiler-rt are potentially different from our
# toolchain sources. The only way to ensure that this test builds
# correctly is to make it a prebuilt based on our latest toolchain
# sources. Note that this is only created/compiled by the previous
# stage (usually stage1) compiler. We are not doing a subsequent
# compile with our stage2 binaries to construct any further
# device-targeted objects.
def install_sanitizer_tests(build_dir, install_dir, host):
# Tuples of (product, arch)
product_to_arch = (
('generic', 'arm'),
('generic_arm64', 'aarch64'),
('generic_x86', 'i686'),
('generic_mips', 'mips'),
('generic_mips64', 'mips64'),
)
for product, arch in product_to_arch:
product_dir = os.path.join(build_dir, 'target/product', product)
test_module = 'asan_test'
test_dir = os.path.join(product_dir, 'obj/EXECUTABLES',
'{}_intermediates'.format(test_module))
built_test = os.path.join(test_dir, 'PACKED', test_module)
test_dst = os.path.join(install_dir, 'test', arch, 'bin')
makedirs(test_dst)
install_file(built_test, test_dst)
def install_host_sanitizers(build_dir, host, lib_dst):
# Tuples of (name, multilib).
libs = (
('asan', True),
('asan_cxx', True),
('ubsan_standalone', True),
('ubsan_standalone_cxx', True),
('tsan', False),
('tsan_cxx', False),
)
obj32 = os.path.join(build_dir, 'host', host, 'obj32/STATIC_LIBRARIES')
obj64 = os.path.join(build_dir, 'host', host, 'obj/STATIC_LIBRARIES')
for lib, is_multilib in libs:
built_lib_name = 'lib{}.a'.format(lib)
obj64_dir = os.path.join(obj64, 'lib{}_intermediates'.format(lib))
lib64_name = 'libclang_rt.{}-x86_64.a'.format(lib)
built_lib64 = os.path.join(obj64_dir, built_lib_name)
install_file(built_lib64, os.path.join(lib_dst, lib64_name))
if is_multilib:
obj32_dir = os.path.join(obj32, 'lib{}_intermediates'.format(lib))
lib32_name = 'libclang_rt.{}-i686.a'.format(lib)
built_lib32 = os.path.join(obj32_dir, built_lib_name)
install_file(built_lib32, os.path.join(lib_dst, lib32_name))
def install_license_files(install_dir):
projects = (
'clang',
'clang-tools-extra',
'compiler-rt',
'libcxx',
'libcxxabi',
'libunwind_llvm',
'llvm',
'openmp_llvm'
)
notices = []
for project in projects:
project_path = android_path('external', project)
license_pattern = os.path.join(project_path, 'MODULE_LICENSE_*')
for license_file in glob.glob(license_pattern):
install_file(license_file, install_dir)
with open(os.path.join(project_path, 'NOTICE')) as notice_file:
notices.append(notice_file.read())
with open(os.path.join(install_dir, 'NOTICE'), 'w') as notice_file:
notice_file.write('\n'.join(notices))
def install_repo_prop(install_dir):
file_name = 'repo.prop'
dist_dir = os.environ.get('DIST_DIR')
if dist_dir is not None:
dist_repo_prop = os.path.join(dist_dir, file_name)
install_file(dist_repo_prop, install_dir)
else:
out_file = os.path.join(install_dir, file_name)
with open(out_file, 'w') as prop_file:
cmd = [
'repo', 'forall', '-c',
'echo $REPO_PROJECT $(git rev-parse HEAD)',
]
check_call(cmd, stdout=prop_file)
def install_compiler_wrapper(install_dir, host):
is_windows = host.startswith('windows')
bin_ext = '.exe' if is_windows else ''
built_files = [
'bin/clang' + bin_ext,
'bin/clang++' + bin_ext,
]
if is_windows:
built_files.extend([
'bin/clang_32' + bin_ext,
])
wrapper_dir = android_path('external/clang')
wrapper = os.path.join(wrapper_dir, 'compiler_wrapper')
for built_file in built_files:
old_file = os.path.join(install_dir, built_file)
new_file = os.path.join(install_dir, built_file + ".real")
rename(old_file, new_file)
install_file(wrapper, old_file)
def parse_args():
parser = argparse.ArgumentParser()
parser.add_argument('-j', action='store', dest='jobs', type=int,
default=multiprocessing.cpu_count(),
help='Specify number of executed jobs')
parser.add_argument(
'--build-name', default='dev', help='Release name for the package.')
parser.add_argument(
'--dry-run', action='store_true', default=False,
help='Skip running commands; just print.')
parser.add_argument(
'-v', '--verbose', action='store_true', default=False,
help='Print debug output.')
multi_stage_group = parser.add_mutually_exclusive_group()
multi_stage_group.add_argument(
'--multi-stage', action='store_true', default=True,
help='Perform multi-stage build (enabled by default).')
multi_stage_group.add_argument(
'--no-multi-stage', action='store_false', dest='multi_stage',
help='Do not perform multi-stage build.')
build_all_llvm_tools_group = parser.add_mutually_exclusive_group()
build_all_llvm_tools_group.add_argument(
'--build-all-llvm-tools', action='store_true', default=True,
help='Build all the LLVM tools/utilities.')
build_all_llvm_tools_group.add_argument(
'--no-build-all-llvm-tools', action='store_false',
dest='build_all_llvm_tools',
help='Do not build all the LLVM tools/utilities.')
build_debug_clang_group = parser.add_mutually_exclusive_group()
build_debug_clang_group.add_argument(
'--debug-clang', action='store_true', default=True,
help='Also generate a debug version of clang (enabled by default).')
build_debug_clang_group.add_argument(
'--no-debug-clang', action='store_false',
dest='debug_clang',
help='Skip generating a debug version of clang.')
return parser.parse_args()
def main():
args = parse_args()
log_level = logging.INFO
if args.verbose:
log_level = logging.DEBUG
logging.basicConfig(level=log_level)
logger().info('chdir %s', android_path())
os.chdir(android_path())
Config.dry_run = args.dry_run
if sys.platform.startswith('linux'):
hosts = ['linux-x86', 'windows-x86']
elif sys.platform == 'darwin':
hosts = ['darwin-x86']
else:
raise RuntimeError('Unsupported host: {}'.format(sys.platform))
stage_1_out_dir = build_path('stage1')
# For a multi-stage build, build a minimum clang for the first stage that is
# just enough to build the second stage.
is_stage1_final = not args.multi_stage
build(out_dir=stage_1_out_dir,
build_all_clang_tools=is_stage1_final,
build_all_llvm_tools=(is_stage1_final and args.build_all_llvm_tools),
max_jobs=args.jobs)
final_out_dir = stage_1_out_dir
if args.multi_stage:
stage_1_install_dir = build_path('stage1-install')
for host in hosts:
package_name = 'clang-' + args.build_name
install_host_dir = os.path.join(stage_1_install_dir, host)
install_dir = os.path.join(install_host_dir, package_name)
# Remove any previously installed toolchain so it doesn't pollute
# the build.
if os.path.exists(install_host_dir):
rmtree(install_host_dir)
install_minimal_toolchain(stage_1_out_dir, install_dir, host, True)
stage_2_out_dir = build_path('stage2')
build(out_dir=stage_2_out_dir, prebuilts_path=stage_1_install_dir,
prebuilts_version=package_name,
build_all_clang_tools=True,
build_all_llvm_tools=args.build_all_llvm_tools,
max_jobs=args.jobs)
final_out_dir = stage_2_out_dir
if args.debug_clang:
debug_clang_out_dir = build_path('debug')
build(out_dir=debug_clang_out_dir,
prebuilts_path=stage_1_install_dir,
prebuilts_version=package_name,
build_all_clang_tools=True,
build_all_llvm_tools=args.build_all_llvm_tools,
debug_clang=args.debug_clang,
max_jobs=args.jobs)
# Install the actual debug toolchain somewhere, so it is easier to
# use.
debug_package_name = 'clang-debug'
base_debug_install_dir = build_path('debug-install')
for host in hosts:
debug_install_host_dir = os.path.join(
base_debug_install_dir, host)
debug_install_dir = os.path.join(
debug_install_host_dir, debug_package_name)
if os.path.exists(debug_install_host_dir):
rmtree(debug_install_host_dir)
install_toolchain(
debug_clang_out_dir, debug_install_dir, host, False)
dist_dir = ORIG_ENV.get('DIST_DIR', final_out_dir)
for host in hosts:
package_toolchain(final_out_dir, args.build_name, host, dist_dir)
if __name__ == '__main__':
print 'This script and llvm branch are deprecated and unmaintained.'
print 'Use the llvm-toolchain branch (repo init ... -b llvm-toolchain).'
print 'https://android.googlesource.com/toolchain/llvm_android/+/master'
sys.exit(0)