1#!/usr/bin/env python 2# 3# Copyright (C) 2020 The Android Open Source Project 4# 5# Licensed under the Apache License, Version 2.0 (the "License"); 6# you may not use this file except in compliance with the License. 7# You may obtain a copy of the License at 8# 9# http://www.apache.org/licenses/LICENSE-2.0 10# 11# Unless required by applicable law or agreed to in writing, software 12# distributed under the License is distributed on an "AS IS" BASIS, 13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14# See the License for the specific language governing permissions and 15# limitations under the License. 16# 17"""A tool for constructing class loader context.""" 18 19import argparse 20import json 21import sys 22 23from manifest import compare_version_gt 24 25 26def parse_args(args): 27 """Parse commandline arguments.""" 28 parser = argparse.ArgumentParser() 29 parser.add_argument( 30 '--target-sdk-version', 31 default='', 32 dest='sdk', 33 help='specify target SDK version (as it appears in the manifest)') 34 parser.add_argument( 35 '--context-json', 36 default='', 37 dest='context_json', 38 ) 39 parser.add_argument( 40 '--product-packages', 41 default='', 42 dest='product_packages_file', 43 ) 44 return parser.parse_args(args) 45 46 47# Special keyword that means that the context should be added to class loader 48# context regardless of the target SDK version. 49any_sdk = 'any' 50 51context_sep = '#' 52 53 54def encode_class_loader(context, product_packages): 55 host_sub_contexts, target_sub_contexts = encode_class_loaders( 56 context['Subcontexts'], product_packages) 57 58 return ('PCL[%s]%s' % (context['Host'], host_sub_contexts), 59 'PCL[%s]%s' % (context['Device'], target_sub_contexts)) 60 61 62def encode_class_loaders(contexts, product_packages): 63 host_contexts = [] 64 target_contexts = [] 65 66 for context in contexts: 67 if not context['Optional'] or context['Name'] in product_packages: 68 host_context, target_context = encode_class_loader( 69 context, product_packages) 70 host_contexts.append(host_context) 71 target_contexts.append(target_context) 72 73 if host_contexts: 74 return ('{%s}' % context_sep.join(host_contexts), 75 '{%s}' % context_sep.join(target_contexts)) 76 else: 77 return '', '' 78 79 80def construct_context_args(target_sdk, context_json, product_packages): 81 all_contexts = [] 82 83 # CLC for different SDK versions should come in specific order that agrees 84 # with PackageManager. Since PackageManager processes SDK versions in 85 # ascending order and prepends compatibility libraries at the front, the 86 # required order is descending, except for any_sdk that has numerically 87 # the largest order, but must be the last one. Example of correct order: 88 # [30, 29, 28, any_sdk]. There are Python tests to ensure that someone 89 # doesn't change this by accident, but there is no way to guard against 90 # changes in the PackageManager, except for grepping logcat on the first 91 # boot for absence of the following messages: 92 # 93 # `logcat | grep -E 'ClassLoaderContext [a-z ]+ mismatch` 94 95 for sdk, contexts in sorted( 96 ((sdk, contexts) 97 for sdk, contexts in context_json.items() 98 if sdk != any_sdk and compare_version_gt(sdk, target_sdk)), 99 key=lambda item: int(item[0]), reverse=True): 100 all_contexts += contexts 101 102 if any_sdk in context_json: 103 all_contexts += context_json[any_sdk] 104 105 host_contexts, target_contexts = encode_class_loaders( 106 all_contexts, product_packages) 107 108 return ( 109 'class_loader_context_arg=--class-loader-context=PCL[]%s ; ' % 110 host_contexts + 111 'stored_class_loader_context_arg=' 112 '--stored-class-loader-context=PCL[]%s' 113 % target_contexts) 114 115 116def main(): 117 """Program entry point.""" 118 try: 119 args = parse_args(sys.argv[1:]) 120 if not args.sdk: 121 raise SystemExit('target sdk version is not set') 122 123 context_json = json.loads(args.context_json) 124 with open(args.product_packages_file, 'r') as f: 125 product_packages = set(line.strip() for line in f if line.strip()) 126 127 print(construct_context_args(args.sdk, context_json, product_packages)) 128 129 # pylint: disable=broad-except 130 except Exception as err: 131 print('error: ' + str(err), file=sys.stderr) 132 sys.exit(-1) 133 134 135if __name__ == '__main__': 136 main() 137