Split the huge merge_target_files script into multiple files.

Bug: 221858722
Test: m otatools; Use to create merged builds
Test: atest --host releasetools_test
Change-Id: I5f932f160d3f6405b41a7721b1c75cc96749e77b
diff --git a/tools/releasetools/merge/merge_compatibility_checks.py b/tools/releasetools/merge/merge_compatibility_checks.py
new file mode 100644
index 0000000..207abe2
--- /dev/null
+++ b/tools/releasetools/merge/merge_compatibility_checks.py
@@ -0,0 +1,206 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2022 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.
+#
+"""Compatibility checks that should be performed on merged target_files."""
+
+import json
+import logging
+import os
+from xml.etree import ElementTree
+
+import apex_utils
+import check_target_files_vintf
+import common
+import find_shareduid_violation
+
+logger = logging.getLogger(__name__)
+OPTIONS = common.OPTIONS
+
+
+def CheckCompatibility(target_files_dir, partition_map):
+  """Runs various compatibility checks.
+
+  Returns a possibly-empty list of error messages.
+  """
+  errors = []
+
+  errors.extend(CheckVintf(target_files_dir))
+  errors.extend(CheckShareduidViolation(target_files_dir, partition_map))
+  errors.extend(CheckApexDuplicatePackages(target_files_dir, partition_map))
+
+  # The remaining checks only use the following partitions:
+  partition_map = {
+      partition: path
+      for partition, path in partition_map.items()
+      if partition in ('system', 'system_ext', 'product', 'vendor', 'odm')
+  }
+
+  errors.extend(CheckInitRcFiles(target_files_dir, partition_map))
+  errors.extend(CheckCombinedSepolicy(target_files_dir, partition_map))
+
+  return errors
+
+
+def CheckVintf(target_files_dir):
+  """Check for any VINTF issues using check_vintf."""
+  errors = []
+  try:
+    if not check_target_files_vintf.CheckVintf(target_files_dir):
+      errors.append('Incompatible VINTF.')
+  except RuntimeError as err:
+    errors.append(str(err))
+  return errors
+
+
+def CheckShareduidViolation(target_files_dir, partition_map):
+  """Check for any APK sharedUserId violations across partition sets.
+
+  Writes results to META/shareduid_violation_modules.json to help
+  with followup debugging.
+  """
+  errors = []
+  violation = find_shareduid_violation.FindShareduidViolation(
+      target_files_dir, partition_map)
+  shareduid_violation_modules = os.path.join(
+      target_files_dir, 'META', 'shareduid_violation_modules.json')
+  with open(shareduid_violation_modules, 'w') as f:
+    # Write the output to a file to enable debugging.
+    f.write(violation)
+
+    # Check for violations across the partition sets.
+    shareduid_errors = common.SharedUidPartitionViolations(
+        json.loads(violation),
+        [OPTIONS.framework_partition_set, OPTIONS.vendor_partition_set])
+    if shareduid_errors:
+      for error in shareduid_errors:
+        errors.append('APK sharedUserId error: %s' % error)
+      errors.append('See APK sharedUserId violations file: %s' %
+                    shareduid_violation_modules)
+  return errors
+
+
+def CheckInitRcFiles(target_files_dir, partition_map):
+  """Check for any init.rc issues using host_init_verifier."""
+  try:
+    common.RunHostInitVerifier(
+        product_out=target_files_dir, partition_map=partition_map)
+  except RuntimeError as err:
+    return [str(err)]
+  return []
+
+
+def CheckCombinedSepolicy(target_files_dir, partition_map, execute=True):
+  """Uses secilc to compile a split sepolicy file.
+
+  Depends on various */etc/selinux/* and */etc/vintf/* files within partitions.
+  """
+  errors = []
+
+  def get_file(partition, path):
+    if partition not in partition_map:
+      logger.warning('Cannot load SEPolicy files for missing partition %s',
+                     partition)
+      return None
+    file_path = os.path.join(target_files_dir, partition_map[partition], path)
+    if os.path.exists(file_path):
+      return file_path
+    return None
+
+  # Load the kernel sepolicy version from the FCM. This is normally provided
+  # directly to selinux.cpp as a build flag, but is also available in this file.
+  fcm_file = get_file('system', 'etc/vintf/compatibility_matrix.device.xml')
+  if not fcm_file:
+    errors.append('Missing required file for loading sepolicy: '
+                  '/system/etc/vintf/compatibility_matrix.device.xml')
+    return errors
+  kernel_sepolicy_version = ElementTree.parse(fcm_file).getroot().find(
+      'sepolicy/kernel-sepolicy-version').text
+
+  # Load the vendor's plat sepolicy version. This is the version used for
+  # locating sepolicy mapping files.
+  vendor_plat_version_file = get_file('vendor',
+                                      'etc/selinux/plat_sepolicy_vers.txt')
+  if not vendor_plat_version_file:
+    errors.append('Missing required sepolicy file %s' %
+                  vendor_plat_version_file)
+    return errors
+  with open(vendor_plat_version_file) as f:
+    vendor_plat_version = f.read().strip()
+
+  # Use the same flags and arguments as selinux.cpp OpenSplitPolicy().
+  cmd = ['secilc', '-m', '-M', 'true', '-G', '-N']
+  cmd.extend(['-c', kernel_sepolicy_version])
+  cmd.extend(['-o', os.path.join(target_files_dir, 'META/combined_sepolicy')])
+  cmd.extend(['-f', '/dev/null'])
+
+  required_policy_files = (
+      ('system', 'etc/selinux/plat_sepolicy.cil'),
+      ('system', 'etc/selinux/mapping/%s.cil' % vendor_plat_version),
+      ('vendor', 'etc/selinux/vendor_sepolicy.cil'),
+      ('vendor', 'etc/selinux/plat_pub_versioned.cil'),
+  )
+  for policy in (map(lambda partition_and_path: get_file(*partition_and_path),
+                     required_policy_files)):
+    if not policy:
+      errors.append('Missing required sepolicy file %s' % policy)
+      return errors
+    cmd.append(policy)
+
+  optional_policy_files = (
+      ('system', 'etc/selinux/mapping/%s.compat.cil' % vendor_plat_version),
+      ('system_ext', 'etc/selinux/system_ext_sepolicy.cil'),
+      ('system_ext', 'etc/selinux/mapping/%s.cil' % vendor_plat_version),
+      ('product', 'etc/selinux/product_sepolicy.cil'),
+      ('product', 'etc/selinux/mapping/%s.cil' % vendor_plat_version),
+      ('odm', 'etc/selinux/odm_sepolicy.cil'),
+  )
+  for policy in (map(lambda partition_and_path: get_file(*partition_and_path),
+                     optional_policy_files)):
+    if policy:
+      cmd.append(policy)
+
+  try:
+    if execute:
+      common.RunAndCheckOutput(cmd)
+    else:
+      return cmd
+  except RuntimeError as err:
+    errors.append(str(err))
+
+  return errors
+
+
+def CheckApexDuplicatePackages(target_files_dir, partition_map):
+  """Checks if the same APEX package name is provided by multiple partitions."""
+  errors = []
+
+  apex_packages = set()
+  for partition in partition_map.keys():
+    try:
+      apex_info = apex_utils.GetApexInfoFromTargetFiles(
+          target_files_dir, partition, compressed_only=False)
+    except RuntimeError as err:
+      errors.append(str(err))
+      apex_info = []
+    partition_apex_packages = set([info.package_name for info in apex_info])
+    duplicates = apex_packages.intersection(partition_apex_packages)
+    if duplicates:
+      errors.append(
+          'Duplicate APEX package_names found in multiple partitions: %s' %
+          ' '.join(duplicates))
+    apex_packages.update(partition_apex_packages)
+
+  return errors