tools/releasetools/merge_target_files.py - SHIFTPHONES/android_build - Gitiles

 #!/usr/bin/env python
 #
 # Copyright (C) 2019 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.

 """
 This script merges two partial target files packages (one of which contains
 system files, and the other contains non-system files) together, producing a
 complete target files package that can be used to generate an OTA package.

 Usage: merge_target_files.py [args]

   --system-target-files system-target-files-zip-archive
       The input target files package containing system bits. This is a zip
       archive.

   --other-target-files other-target-files-zip-archive
       The input target files package containing other bits. This is a zip
       archive.

   --output-target-files output-target-files-package
       The output merged target files package. Also a zip archive.
 """

 from __future__ import print_function

 import fnmatch
 import logging
 import os
 import sys
 import zipfile

 import common
 import add_img_to_target_files

 logger = logging.getLogger(__name__)
 OPTIONS = common.OPTIONS
 OPTIONS.verbose = True
 OPTIONS.system_target_files = None
 OPTIONS.other_target_files = None
 OPTIONS.output_target_files = None
 OPTIONS.keep_tmp = False

 # system_extract_as_is_item_list is a list of items to extract from the partial
 # system target files package as is, meaning these items will land in the
 # output target files package exactly as they appear in the input partial
 # system target files package.

 system_extract_as_is_item_list = [
     'META/apkcerts.txt',
     'META/filesystem_config.txt',
     'META/root_filesystem_config.txt',
     'META/system_manifest.xml',
     'META/system_matrix.xml',
     'META/update_engine_config.txt',
     'PRODUCT/*',
     'ROOT/*',
     'SYSTEM/*',
 ]

 # system_extract_special_item_list is a list of items to extract from the
 # partial system target files package that need some special processing, such
 # as some sort of combination with items from the partial other target files
 # package.

 system_extract_special_item_list = [
     'META/*',
 ]

 # system_misc_info_keys is a list of keys to obtain from the system instance of
 # META/misc_info.txt. The remaining keys from the other instance.

 system_misc_info_keys = [
     'avb_system_hashtree_enable',
     'avb_system_add_hashtree_footer_args',
     'avb_system_key_path',
     'avb_system_algorithm',
     'avb_system_rollback_index_location',
     'avb_product_hashtree_enable',
     'avb_product_add_hashtree_footer_args',
     'avb_product_services_hashtree_enable',
     'avb_product_services_add_hashtree_footer_args',
     'system_root_image',
     'root_dir',
     'ab_update',
     'default_system_dev_certificate',
     'system_size',
 ]

 # other_extract_as_is_item_list is a list of items to extract from the partial
 # other target files package as is, meaning these items will land in the output
 # target files package exactly as they appear in the input partial other target
 # files package.

 other_extract_as_is_item_list = [
     'META/boot_filesystem_config.txt',
     'META/otakeys.txt',
     'META/releasetools.py',
     'META/vendor_filesystem_config.txt',
     'META/vendor_manifest.xml',
     'META/vendor_matrix.xml',
     'BOOT/*',
     'DATA/*',
     'ODM/*',
     'OTA/android-info.txt',
     'PREBUILT_IMAGES/*',
     'RADIO/*',
     'VENDOR/*',
 ]

 # other_extract_for_merge_item_list is a list of items to extract from the
 # partial other target files package that need some special processing, such as
 # some sort of combination with items from the partial system target files
 # package.

 other_extract_special_item_list = [
     'META/*',
 ]


 def extract_items(target_files, target_files_temp_dir, extract_item_list):
   """Extract items from target files to temporary directory.

   This function extracts from the specified target files zip archive into the
   specified temporary directory, the items specified in the extract item list.

   Args:
     target_files: The target files zip archive from which to extract items.

     target_files_temp_dir: The temporary directory where the extracted items
     will land.

     extract_item_list: A list of items to extract.
   """

   logger.info('extracting from %s', target_files)

   # Filter the extract_item_list to remove any items that do not exist in the
   # zip file. Otherwise, the extraction step will fail.

   with zipfile.ZipFile(
       target_files,
       'r',
       allowZip64=True) as target_files_zipfile:
     target_files_namelist = target_files_zipfile.namelist()

   filtered_extract_item_list = []
   for pattern in extract_item_list:
     matching_namelist = fnmatch.filter(target_files_namelist, pattern)
     if not matching_namelist:
       logger.warning('no match for %s', pattern)
     else:
       filtered_extract_item_list.append(pattern)

   # Extract from target_files into target_files_temp_dir the
   # filtered_extract_item_list.

   common.UnzipToDir(
       target_files,
       target_files_temp_dir,
       filtered_extract_item_list)


 def process_ab_partitions_txt(
     system_target_files_temp_dir,
     other_target_files_temp_dir,
     output_target_files_temp_dir):
   """Perform special processing for META/ab_partitions.txt

   This function merges the contents of the META/ab_partitions.txt files from
   the system directory and the other directory, placing the merged result in
   the output directory. The precondition in that the files are already
   extracted. The post condition is that the output META/ab_partitions.txt
   contains the merged content. The format for each ab_partitions.txt a one
   partition name per line. The output file contains the union of the parition
   names.

   Args:
     system_target_files_temp_dir: The name of a directory containing the
     special items extracted from the system target files package.

     other_target_files_temp_dir: The name of a directory containing the
     special items extracted from the other target files package.

     output_target_files_temp_dir: The name of a directory that will be used
     to create the output target files package after all the special cases
     are processed.
   """

   system_ab_partitions_txt = os.path.join(
       system_target_files_temp_dir, 'META', 'ab_partitions.txt')

   other_ab_partitions_txt = os.path.join(
       other_target_files_temp_dir, 'META', 'ab_partitions.txt')

   with open(system_ab_partitions_txt) as f:
     system_ab_partitions = f.read().splitlines()

   with open(other_ab_partitions_txt) as f:
     other_ab_partitions = f.read().splitlines()

   output_ab_partitions = set(system_ab_partitions + other_ab_partitions)

   output_ab_partitions_txt = os.path.join(
       output_target_files_temp_dir, 'META', 'ab_partitions.txt')

   with open(output_ab_partitions_txt, 'w') as output:
     for partition in sorted(output_ab_partitions):
       output.write('%s\n' % partition)


 def process_misc_info_txt(
     system_target_files_temp_dir,
     other_target_files_temp_dir,
     output_target_files_temp_dir):
   """Perform special processing for META/misc_info.txt

   This function merges the contents of the META/misc_info.txt files from the
   system directory and the other directory, placing the merged result in the
   output directory. The precondition in that the files are already extracted.
   The post condition is that the output META/misc_info.txt contains the merged
   content.

   Args:
     system_target_files_temp_dir: The name of a directory containing the
     special items extracted from the system target files package.

     other_target_files_temp_dir: The name of a directory containing the
     special items extracted from the other target files package.

     output_target_files_temp_dir: The name of a directory that will be used
     to create the output target files package after all the special cases
     are processed.
   """

   def read_helper(d):
     misc_info_txt = os.path.join(d, 'META', 'misc_info.txt')
     with open(misc_info_txt) as f:
       return list(f.read().splitlines())

   system_info_dict = common.LoadDictionaryFromLines(
       read_helper(system_target_files_temp_dir))

   # We take most of the misc info from the other target files.

   merged_info_dict = common.LoadDictionaryFromLines(
       read_helper(other_target_files_temp_dir))

   # Replace certain values in merged_info_dict with values from
   # system_info_dict. TODO(b/124467065): This should be more flexible than
   # using the hard-coded system_misc_info_keys.

   for key in system_misc_info_keys:
     merged_info_dict[key] = system_info_dict[key]

   output_misc_info_txt = os.path.join(
       output_target_files_temp_dir,
       'META', 'misc_info.txt')

   sorted_keys = sorted(merged_info_dict.keys())

   with open(output_misc_info_txt, 'w') as output:
     for key in sorted_keys:
       output.write('{}={}\n'.format(key, merged_info_dict[key]))


 def process_file_contexts_bin(temp_dir, output_target_files_temp_dir):
   """Perform special processing for META/file_contexts.bin.

   This function combines plat_file_contexts and vendor_file_contexts, which are
   expected to already be extracted in temp_dir, to produce a merged
   file_contexts.bin that will land in temp_dir at META/file_contexts.bin.

   Args:
     temp_dir: The name of a scratch directory that this function can use for
     intermediate files generated during processing.

     output_target_files_temp_dir: The name of the working directory that must
     already contain plat_file_contexts and vendor_file_contexts (in the
     appropriate sub directories), and to which META/file_contexts.bin will be
     written.
   """

   # To create a merged file_contexts.bin file, we use the system and vendor
   # file contexts files as input, the m4 tool to combine them, the sorting tool
   # to sort, and finally the sefcontext_compile tool to generate the final
   # output. We currently omit a checkfc step since the files had been checked
   # as part of the build.

   # The m4 step concatenates the two input files contexts files. Since m4
   # writes to stdout, we receive that into an array of bytes, and then write it
   # to a file.

   # Collect the file contexts that we're going to combine from SYSTEM, VENDOR,
   # PRODUCT, and ODM. We require SYSTEM and VENDOR, but others are optional.

   file_contexts_list = []

   for partition in ['SYSTEM', 'VENDOR', 'PRODUCT', 'ODM']:
     prefix = 'plat' if partition == 'SYSTEM' else partition.lower()

     file_contexts = os.path.join(
         output_target_files_temp_dir,
         partition, 'etc', 'selinux', prefix + '_file_contexts')

     mandatory = partition in ['SYSTEM', 'VENDOR']

     if mandatory or os.path.isfile(file_contexts):
       file_contexts_list.append(file_contexts)
     else:
       logger.warning('file not found: %s', file_contexts)

   command = ['m4', '--fatal-warnings', '-s'] + file_contexts_list

   merged_content = common.RunAndCheckOutput(command, verbose=False)

   merged_file_contexts_txt = os.path.join(temp_dir, 'merged_file_contexts.txt')

   with open(merged_file_contexts_txt, 'wb') as f:
     f.write(merged_content)

   # The sort step sorts the concatenated file.

   sorted_file_contexts_txt = os.path.join(temp_dir, 'sorted_file_contexts.txt')
   command = ['fc_sort', merged_file_contexts_txt, sorted_file_contexts_txt]
   common.RunAndWait(command, verbose=True)

   # Finally, the compile step creates the final META/file_contexts.bin.

   file_contexts_bin = os.path.join(
       output_target_files_temp_dir,
       'META', 'file_contexts.bin')

   command = [
       'sefcontext_compile',
       '-o', file_contexts_bin,
       sorted_file_contexts_txt,
   ]

   common.RunAndWait(command, verbose=True)


 def process_special_cases(
     temp_dir,
     system_target_files_temp_dir,
     other_target_files_temp_dir,
     output_target_files_temp_dir):
   """Perform special-case processing for certain target files items.

   Certain files in the output target files package require special-case
   processing. This function performs all that special-case processing.

   Args:
     temp_dir: The name of a scratch directory that this function can use for
     intermediate files generated during processing.

     system_target_files_temp_dir: The name of a directory containing the
     special items extracted from the system target files package.

     other_target_files_temp_dir: The name of a directory containing the
     special items extracted from the other target files package.

     output_target_files_temp_dir: The name of a directory that will be used
     to create the output target files package after all the special cases
     are processed.
   """

   process_ab_partitions_txt(
       system_target_files_temp_dir=system_target_files_temp_dir,
       other_target_files_temp_dir=other_target_files_temp_dir,
       output_target_files_temp_dir=output_target_files_temp_dir)

   process_misc_info_txt(
       system_target_files_temp_dir=system_target_files_temp_dir,
       other_target_files_temp_dir=other_target_files_temp_dir,
       output_target_files_temp_dir=output_target_files_temp_dir)

   process_file_contexts_bin(
       temp_dir=temp_dir,
       output_target_files_temp_dir=output_target_files_temp_dir)


 def merge_target_files(
     temp_dir,
     system_target_files,
     other_target_files,
     output_target_files):
   """Merge two target files packages together.

   This function takes system and other target files packages as input, performs
   various file extractions, special case processing, and finally creates a
   merged zip archive as output.

   Args:
     temp_dir: The name of a directory we use when we extract items from the
     input target files packages, and also a scratch directory that we use for
     temporary files.

     system_target_files: The name of the zip archive containing the system
     partial target files package.

     other_target_files: The name of the zip archive containing the other
     partial target files package.

     output_target_files: The name of the output zip archive target files
     package created by merging system and other.
   """

   # Create directory names that we'll use when we extract files from system,
   # and other, and for zipping the final output.

   system_target_files_temp_dir = os.path.join(temp_dir, 'system')
   other_target_files_temp_dir = os.path.join(temp_dir, 'other')
   output_target_files_temp_dir = os.path.join(temp_dir, 'output')

   # Extract "as is" items from the input system partial target files package.
   # We extract them directly into the output temporary directory since the
   # items do not need special case processing.

   extract_items(
       target_files=system_target_files,
       target_files_temp_dir=output_target_files_temp_dir,
       extract_item_list=system_extract_as_is_item_list)

   # Extract "as is" items from the input other partial target files package. We
   # extract them directly into the output temporary directory since the items
   # do not need special case processing.

   extract_items(
       target_files=other_target_files,
       target_files_temp_dir=output_target_files_temp_dir,
       extract_item_list=other_extract_as_is_item_list)

   # Extract "special" items from the input system partial target files package.
   # We extract these items to different directory since they require special
   # processing before they will end up in the output directory.

   extract_items(
       target_files=system_target_files,
       target_files_temp_dir=system_target_files_temp_dir,
       extract_item_list=system_extract_special_item_list)

   # Extract "special" items from the input other partial target files package.
   # We extract these items to different directory since they require special
   # processing before they will end up in the output directory.

   extract_items(
       target_files=other_target_files,
       target_files_temp_dir=other_target_files_temp_dir,
       extract_item_list=other_extract_special_item_list)

   # Now that the temporary directories contain all the extracted files, perform
   # special case processing on any items that need it. After this function
   # completes successfully, all the files we need to create the output target
   # files package are in place.

   process_special_cases(
       temp_dir=temp_dir,
       system_target_files_temp_dir=system_target_files_temp_dir,
       other_target_files_temp_dir=other_target_files_temp_dir,
       output_target_files_temp_dir=output_target_files_temp_dir)

   # Regenerate IMAGES in the temporary directory.

   add_img_args = [
       '--verbose',
       output_target_files_temp_dir,
   ]

   add_img_to_target_files.main(add_img_args)

   # Finally, create the output target files zip archive.

   output_zip = os.path.abspath(output_target_files)
   output_target_files_list = os.path.join(temp_dir, 'output.list')
   output_target_files_meta_dir = os.path.join(
       output_target_files_temp_dir, 'META')

   command = [
       'find',
       output_target_files_meta_dir,
   ]
   # TODO(bpeckham): sort this to be more like build.
   meta_content = common.RunAndCheckOutput(command, verbose=False)
   command = [
       'find',
       output_target_files_temp_dir,
       '-path',
       output_target_files_meta_dir,
       '-prune',
       '-o',
       '-print'
   ]
   # TODO(bpeckham): sort this to be more like build.
   other_content = common.RunAndCheckOutput(command, verbose=False)

   with open(output_target_files_list, 'wb') as f:
     f.write(meta_content)
     f.write(other_content)

   command = [
       'soong_zip',
       '-d',
       '-o', output_zip,
       '-C', output_target_files_temp_dir,
       '-l', output_target_files_list,
   ]
   logger.info('creating %s', output_target_files)
   common.RunAndWait(command, verbose=True)


 def merge_target_files_with_temp_dir(
     system_target_files,
     other_target_files,
     output_target_files,
     keep_tmp):
   """Manage the creation and cleanup of the temporary directory.

   This function wraps merge_target_files after first creating a temporary
   directory. It also cleans up the temporary directory.

   Args:
     system_target_files: The name of the zip archive containing the system
     partial target files package.

     other_target_files: The name of the zip archive containing the other
     partial target files package.

     output_target_files: The name of the output zip archive target files
     package created by merging system and other.

     keep_tmp: Keep the temporary directory after processing is complete.
   """

   # Create a temporary directory. This will serve as the parent of directories
   # we use when we extract items from the input target files packages, and also
   # a scratch directory that we use for temporary files.

   logger.info(
       'starting: merge system %s and other %s into output %s',
       system_target_files,
       other_target_files,
       output_target_files)

   temp_dir = common.MakeTempDir(prefix='merge_target_files_')

   try:
     merge_target_files(
         temp_dir=temp_dir,
         system_target_files=system_target_files,
         other_target_files=other_target_files,
         output_target_files=output_target_files)
   except:
     raise
   finally:
     if keep_tmp:
       logger.info('keeping %s', temp_dir)
     else:
       common.Cleanup()


 def main():
   """The main function.

   Process command line arguments, then call merge_target_files_with_temp_dir to
   perform the heavy lifting.
   """

   common.InitLogging()

   def option_handler(o, a):
     if o == '--system-target-files':
       OPTIONS.system_target_files = a
     elif o == '--other-target-files':
       OPTIONS.other_target_files = a
     elif o == '--output-target-files':
       OPTIONS.output_target_files = a
     elif o == '--keep_tmp':
       OPTIONS.keep_tmp = True
     else:
       return False
     return True

   args = common.ParseOptions(
       sys.argv[1:], __doc__,
       extra_long_opts=[
           'system-target-files=',
           'other-target-files=',
           'output-target-files=',
           "keep_tmp",
       ],
       extra_option_handler=option_handler)

   if (len(args) != 0 or
       OPTIONS.system_target_files is None or
       OPTIONS.other_target_files is None or
       OPTIONS.output_target_files is None):
     common.Usage(__doc__)
     sys.exit(1)

   merge_target_files_with_temp_dir(
       system_target_files=OPTIONS.system_target_files,
       other_target_files=OPTIONS.other_target_files,
       output_target_files=OPTIONS.output_target_files,
       keep_tmp=OPTIONS.keep_tmp)


 if __name__ == '__main__':
   main()
	#!/usr/bin/env python
	#
	# Copyright (C) 2019 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.

	"""
	This script merges two partial target files packages (one of which contains
	system files, and the other contains non-system files) together, producing a
	complete target files package that can be used to generate an OTA package.

	Usage: merge_target_files.py [args]

	--system-target-files system-target-files-zip-archive
	The input target files package containing system bits. This is a zip
	archive.

	--other-target-files other-target-files-zip-archive
	The input target files package containing other bits. This is a zip
	archive.

	--output-target-files output-target-files-package
	The output merged target files package. Also a zip archive.
	"""

	from __future__ import print_function

	import fnmatch
	import logging
	import os
	import sys
	import zipfile

	import common
	import add_img_to_target_files

	logger = logging.getLogger(__name__)
	OPTIONS = common.OPTIONS
	OPTIONS.verbose = True
	OPTIONS.system_target_files = None
	OPTIONS.other_target_files = None
	OPTIONS.output_target_files = None
	OPTIONS.keep_tmp = False

	# system_extract_as_is_item_list is a list of items to extract from the partial
	# system target files package as is, meaning these items will land in the
	# output target files package exactly as they appear in the input partial
	# system target files package.

	system_extract_as_is_item_list = [
	'META/apkcerts.txt',
	'META/filesystem_config.txt',
	'META/root_filesystem_config.txt',
	'META/system_manifest.xml',
	'META/system_matrix.xml',
	'META/update_engine_config.txt',
	'PRODUCT/*',
	'ROOT/*',
	'SYSTEM/*',
	]

	# system_extract_special_item_list is a list of items to extract from the
	# partial system target files package that need some special processing, such
	# as some sort of combination with items from the partial other target files
	# package.

	system_extract_special_item_list = [
	'META/*',
	]

	# system_misc_info_keys is a list of keys to obtain from the system instance of
	# META/misc_info.txt. The remaining keys from the other instance.

	system_misc_info_keys = [
	'avb_system_hashtree_enable',
	'avb_system_add_hashtree_footer_args',
	'avb_system_key_path',
	'avb_system_algorithm',
	'avb_system_rollback_index_location',
	'avb_product_hashtree_enable',
	'avb_product_add_hashtree_footer_args',
	'avb_product_services_hashtree_enable',
	'avb_product_services_add_hashtree_footer_args',
	'system_root_image',
	'root_dir',
	'ab_update',
	'default_system_dev_certificate',
	'system_size',
	]

	# other_extract_as_is_item_list is a list of items to extract from the partial
	# other target files package as is, meaning these items will land in the output
	# target files package exactly as they appear in the input partial other target
	# files package.

	other_extract_as_is_item_list = [
	'META/boot_filesystem_config.txt',
	'META/otakeys.txt',
	'META/releasetools.py',
	'META/vendor_filesystem_config.txt',
	'META/vendor_manifest.xml',
	'META/vendor_matrix.xml',
	'BOOT/*',
	'DATA/*',
	'ODM/*',
	'OTA/android-info.txt',
	'PREBUILT_IMAGES/*',
	'RADIO/*',
	'VENDOR/*',
	]

	# other_extract_for_merge_item_list is a list of items to extract from the
	# partial other target files package that need some special processing, such as
	# some sort of combination with items from the partial system target files
	# package.

	other_extract_special_item_list = [
	'META/*',
	]


	def extract_items(target_files, target_files_temp_dir, extract_item_list):
	"""Extract items from target files to temporary directory.

	This function extracts from the specified target files zip archive into the
	specified temporary directory, the items specified in the extract item list.

	Args:
	target_files: The target files zip archive from which to extract items.

	target_files_temp_dir: The temporary directory where the extracted items
	will land.

	extract_item_list: A list of items to extract.
	"""

	logger.info('extracting from %s', target_files)

	# Filter the extract_item_list to remove any items that do not exist in the
	# zip file. Otherwise, the extraction step will fail.

	with zipfile.ZipFile(
	target_files,
	'r',
	allowZip64=True) as target_files_zipfile:
	target_files_namelist = target_files_zipfile.namelist()

	filtered_extract_item_list = []
	for pattern in extract_item_list:
	matching_namelist = fnmatch.filter(target_files_namelist, pattern)
	if not matching_namelist:
	logger.warning('no match for %s', pattern)
	else:
	filtered_extract_item_list.append(pattern)

	# Extract from target_files into target_files_temp_dir the
	# filtered_extract_item_list.

	common.UnzipToDir(
	target_files,
	target_files_temp_dir,
	filtered_extract_item_list)


	def process_ab_partitions_txt(
	system_target_files_temp_dir,
	other_target_files_temp_dir,
	output_target_files_temp_dir):
	"""Perform special processing for META/ab_partitions.txt

	This function merges the contents of the META/ab_partitions.txt files from
	the system directory and the other directory, placing the merged result in
	the output directory. The precondition in that the files are already
	extracted. The post condition is that the output META/ab_partitions.txt
	contains the merged content. The format for each ab_partitions.txt a one
	partition name per line. The output file contains the union of the parition
	names.

	Args:
	system_target_files_temp_dir: The name of a directory containing the
	special items extracted from the system target files package.

	other_target_files_temp_dir: The name of a directory containing the
	special items extracted from the other target files package.

	output_target_files_temp_dir: The name of a directory that will be used
	to create the output target files package after all the special cases
	are processed.
	"""

	system_ab_partitions_txt = os.path.join(
	system_target_files_temp_dir, 'META', 'ab_partitions.txt')

	other_ab_partitions_txt = os.path.join(
	other_target_files_temp_dir, 'META', 'ab_partitions.txt')

	with open(system_ab_partitions_txt) as f:
	system_ab_partitions = f.read().splitlines()

	with open(other_ab_partitions_txt) as f:
	other_ab_partitions = f.read().splitlines()

	output_ab_partitions = set(system_ab_partitions + other_ab_partitions)

	output_ab_partitions_txt = os.path.join(
	output_target_files_temp_dir, 'META', 'ab_partitions.txt')

	with open(output_ab_partitions_txt, 'w') as output:
	for partition in sorted(output_ab_partitions):
	output.write('%s\n' % partition)


	def process_misc_info_txt(
	system_target_files_temp_dir,
	other_target_files_temp_dir,
	output_target_files_temp_dir):
	"""Perform special processing for META/misc_info.txt

	This function merges the contents of the META/misc_info.txt files from the
	system directory and the other directory, placing the merged result in the
	output directory. The precondition in that the files are already extracted.
	The post condition is that the output META/misc_info.txt contains the merged
	content.

	Args:
	system_target_files_temp_dir: The name of a directory containing the
	special items extracted from the system target files package.

	other_target_files_temp_dir: The name of a directory containing the
	special items extracted from the other target files package.

	output_target_files_temp_dir: The name of a directory that will be used
	to create the output target files package after all the special cases
	are processed.
	"""

	def read_helper(d):
	misc_info_txt = os.path.join(d, 'META', 'misc_info.txt')
	with open(misc_info_txt) as f:
	return list(f.read().splitlines())

	system_info_dict = common.LoadDictionaryFromLines(
	read_helper(system_target_files_temp_dir))

	# We take most of the misc info from the other target files.

	merged_info_dict = common.LoadDictionaryFromLines(
	read_helper(other_target_files_temp_dir))

	# Replace certain values in merged_info_dict with values from
	# system_info_dict. TODO(b/124467065): This should be more flexible than
	# using the hard-coded system_misc_info_keys.

	for key in system_misc_info_keys:
	merged_info_dict[key] = system_info_dict[key]

	output_misc_info_txt = os.path.join(
	output_target_files_temp_dir,
	'META', 'misc_info.txt')

	sorted_keys = sorted(merged_info_dict.keys())

	with open(output_misc_info_txt, 'w') as output:
	for key in sorted_keys:
	output.write('{}={}\n'.format(key, merged_info_dict[key]))


	def process_file_contexts_bin(temp_dir, output_target_files_temp_dir):
	"""Perform special processing for META/file_contexts.bin.

	This function combines plat_file_contexts and vendor_file_contexts, which are
	expected to already be extracted in temp_dir, to produce a merged
	file_contexts.bin that will land in temp_dir at META/file_contexts.bin.

	Args:
	temp_dir: The name of a scratch directory that this function can use for
	intermediate files generated during processing.

	output_target_files_temp_dir: The name of the working directory that must
	already contain plat_file_contexts and vendor_file_contexts (in the
	appropriate sub directories), and to which META/file_contexts.bin will be
	written.
	"""

	# To create a merged file_contexts.bin file, we use the system and vendor
	# file contexts files as input, the m4 tool to combine them, the sorting tool
	# to sort, and finally the sefcontext_compile tool to generate the final
	# output. We currently omit a checkfc step since the files had been checked
	# as part of the build.

	# The m4 step concatenates the two input files contexts files. Since m4
	# writes to stdout, we receive that into an array of bytes, and then write it
	# to a file.

	# Collect the file contexts that we're going to combine from SYSTEM, VENDOR,
	# PRODUCT, and ODM. We require SYSTEM and VENDOR, but others are optional.

	file_contexts_list = []

	for partition in ['SYSTEM', 'VENDOR', 'PRODUCT', 'ODM']:
	prefix = 'plat' if partition == 'SYSTEM' else partition.lower()

	file_contexts = os.path.join(
	output_target_files_temp_dir,
	partition, 'etc', 'selinux', prefix + '_file_contexts')

	mandatory = partition in ['SYSTEM', 'VENDOR']

	if mandatory or os.path.isfile(file_contexts):
	file_contexts_list.append(file_contexts)
	else:
	logger.warning('file not found: %s', file_contexts)

	command = ['m4', '--fatal-warnings', '-s'] + file_contexts_list

	merged_content = common.RunAndCheckOutput(command, verbose=False)

	merged_file_contexts_txt = os.path.join(temp_dir, 'merged_file_contexts.txt')

	with open(merged_file_contexts_txt, 'wb') as f:
	f.write(merged_content)

	# The sort step sorts the concatenated file.

	sorted_file_contexts_txt = os.path.join(temp_dir, 'sorted_file_contexts.txt')
	command = ['fc_sort', merged_file_contexts_txt, sorted_file_contexts_txt]
	common.RunAndWait(command, verbose=True)

	# Finally, the compile step creates the final META/file_contexts.bin.

	file_contexts_bin = os.path.join(
	output_target_files_temp_dir,
	'META', 'file_contexts.bin')

	command = [
	'sefcontext_compile',
	'-o', file_contexts_bin,
	sorted_file_contexts_txt,
	]

	common.RunAndWait(command, verbose=True)


	def process_special_cases(
	temp_dir,
	system_target_files_temp_dir,
	other_target_files_temp_dir,
	output_target_files_temp_dir):
	"""Perform special-case processing for certain target files items.

	Certain files in the output target files package require special-case
	processing. This function performs all that special-case processing.

	Args:
	temp_dir: The name of a scratch directory that this function can use for
	intermediate files generated during processing.

	system_target_files_temp_dir: The name of a directory containing the
	special items extracted from the system target files package.

	other_target_files_temp_dir: The name of a directory containing the
	special items extracted from the other target files package.

	output_target_files_temp_dir: The name of a directory that will be used
	to create the output target files package after all the special cases
	are processed.
	"""

	process_ab_partitions_txt(
	system_target_files_temp_dir=system_target_files_temp_dir,
	other_target_files_temp_dir=other_target_files_temp_dir,
	output_target_files_temp_dir=output_target_files_temp_dir)

	process_misc_info_txt(
	system_target_files_temp_dir=system_target_files_temp_dir,
	other_target_files_temp_dir=other_target_files_temp_dir,
	output_target_files_temp_dir=output_target_files_temp_dir)

	process_file_contexts_bin(
	temp_dir=temp_dir,
	output_target_files_temp_dir=output_target_files_temp_dir)


	def merge_target_files(
	temp_dir,
	system_target_files,
	other_target_files,
	output_target_files):
	"""Merge two target files packages together.

	This function takes system and other target files packages as input, performs
	various file extractions, special case processing, and finally creates a
	merged zip archive as output.

	Args:
	temp_dir: The name of a directory we use when we extract items from the
	input target files packages, and also a scratch directory that we use for
	temporary files.

	system_target_files: The name of the zip archive containing the system
	partial target files package.

	other_target_files: The name of the zip archive containing the other
	partial target files package.

	output_target_files: The name of the output zip archive target files
	package created by merging system and other.
	"""

	# Create directory names that we'll use when we extract files from system,
	# and other, and for zipping the final output.

	system_target_files_temp_dir = os.path.join(temp_dir, 'system')
	other_target_files_temp_dir = os.path.join(temp_dir, 'other')
	output_target_files_temp_dir = os.path.join(temp_dir, 'output')

	# Extract "as is" items from the input system partial target files package.
	# We extract them directly into the output temporary directory since the
	# items do not need special case processing.

	extract_items(
	target_files=system_target_files,
	target_files_temp_dir=output_target_files_temp_dir,
	extract_item_list=system_extract_as_is_item_list)

	# Extract "as is" items from the input other partial target files package. We
	# extract them directly into the output temporary directory since the items
	# do not need special case processing.

	extract_items(
	target_files=other_target_files,
	target_files_temp_dir=output_target_files_temp_dir,
	extract_item_list=other_extract_as_is_item_list)

	# Extract "special" items from the input system partial target files package.
	# We extract these items to different directory since they require special
	# processing before they will end up in the output directory.

	extract_items(
	target_files=system_target_files,
	target_files_temp_dir=system_target_files_temp_dir,
	extract_item_list=system_extract_special_item_list)

	# Extract "special" items from the input other partial target files package.
	# We extract these items to different directory since they require special
	# processing before they will end up in the output directory.

	extract_items(
	target_files=other_target_files,
	target_files_temp_dir=other_target_files_temp_dir,
	extract_item_list=other_extract_special_item_list)

	# Now that the temporary directories contain all the extracted files, perform
	# special case processing on any items that need it. After this function
	# completes successfully, all the files we need to create the output target
	# files package are in place.

	process_special_cases(
	temp_dir=temp_dir,
	system_target_files_temp_dir=system_target_files_temp_dir,
	other_target_files_temp_dir=other_target_files_temp_dir,
	output_target_files_temp_dir=output_target_files_temp_dir)

	# Regenerate IMAGES in the temporary directory.

	add_img_args = [
	'--verbose',
	output_target_files_temp_dir,
	]

	add_img_to_target_files.main(add_img_args)

	# Finally, create the output target files zip archive.

	output_zip = os.path.abspath(output_target_files)
	output_target_files_list = os.path.join(temp_dir, 'output.list')
	output_target_files_meta_dir = os.path.join(
	output_target_files_temp_dir, 'META')

	command = [
	'find',
	output_target_files_meta_dir,
	]
	# TODO(bpeckham): sort this to be more like build.
	meta_content = common.RunAndCheckOutput(command, verbose=False)
	command = [
	'find',
	output_target_files_temp_dir,
	'-path',
	output_target_files_meta_dir,
	'-prune',
	'-o',
	'-print'
	]
	# TODO(bpeckham): sort this to be more like build.
	other_content = common.RunAndCheckOutput(command, verbose=False)

	with open(output_target_files_list, 'wb') as f:
	f.write(meta_content)
	f.write(other_content)

	command = [
	'soong_zip',
	'-d',
	'-o', output_zip,
	'-C', output_target_files_temp_dir,
	'-l', output_target_files_list,
	]
	logger.info('creating %s', output_target_files)
	common.RunAndWait(command, verbose=True)


	def merge_target_files_with_temp_dir(
	system_target_files,
	other_target_files,
	output_target_files,
	keep_tmp):
	"""Manage the creation and cleanup of the temporary directory.

	This function wraps merge_target_files after first creating a temporary
	directory. It also cleans up the temporary directory.

	Args:
	system_target_files: The name of the zip archive containing the system
	partial target files package.

	other_target_files: The name of the zip archive containing the other
	partial target files package.

	output_target_files: The name of the output zip archive target files
	package created by merging system and other.

	keep_tmp: Keep the temporary directory after processing is complete.
	"""

	# Create a temporary directory. This will serve as the parent of directories
	# we use when we extract items from the input target files packages, and also
	# a scratch directory that we use for temporary files.

	logger.info(
	'starting: merge system %s and other %s into output %s',
	system_target_files,
	other_target_files,
	output_target_files)

	temp_dir = common.MakeTempDir(prefix='merge_target_files_')

	try:
	merge_target_files(
	temp_dir=temp_dir,
	system_target_files=system_target_files,
	other_target_files=other_target_files,
	output_target_files=output_target_files)
	except:
	raise
	finally:
	if keep_tmp:
	logger.info('keeping %s', temp_dir)
	else:
	common.Cleanup()


	def main():
	"""The main function.

	Process command line arguments, then call merge_target_files_with_temp_dir to
	perform the heavy lifting.
	"""

	common.InitLogging()

	def option_handler(o, a):
	if o == '--system-target-files':
	OPTIONS.system_target_files = a
	elif o == '--other-target-files':
	OPTIONS.other_target_files = a
	elif o == '--output-target-files':
	OPTIONS.output_target_files = a
	elif o == '--keep_tmp':
	OPTIONS.keep_tmp = True
	else:
	return False
	return True

	args = common.ParseOptions(
	sys.argv[1:], __doc__,
	extra_long_opts=[
	'system-target-files=',
	'other-target-files=',
	'output-target-files=',
	"keep_tmp",
	],
	extra_option_handler=option_handler)

	if (len(args) != 0 or
	OPTIONS.system_target_files is None or
	OPTIONS.other_target_files is None or
	OPTIONS.output_target_files is None):
	common.Usage(__doc__)
	sys.exit(1)

	merge_target_files_with_temp_dir(
	system_target_files=OPTIONS.system_target_files,
	other_target_files=OPTIONS.other_target_files,
	output_target_files=OPTIONS.output_target_files,
	keep_tmp=OPTIONS.keep_tmp)


	if __name__ == '__main__':
	main()