#!/usr/bin/env python
#
# Copyright (C) 2009 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.
#
#
# Finds differences between two target files packages
#
from __future__ import print_function
import argparse
import contextlib
import os
import re
import subprocess
import sys
import tempfile
def ignore(name):
"""
Files to ignore when diffing
These are packages that we're already diffing elsewhere,
or files that we expect to be different for every build,
or known problems.
"""
# We're looking at the files that make the images, so no need to search them
if name in ['IMAGES']:
return True
# These are packages of the recovery partition, which we're already diffing
if name in ['SYSTEM/etc/recovery-resource.dat',
'SYSTEM/recovery-from-boot.p']:
return True
# These files are just the BUILD_NUMBER, and will always be different
if name in ['BOOT/RAMDISK/selinux_version',
'RECOVERY/RAMDISK/selinux_version']:
return True
# b/26956807 .odex files are not deterministic
if name.endswith('.odex'):
return True
return False
def rewrite_build_property(original, new):
"""
Rewrite property files to remove values known to change for every build
"""
skipped = ['ro.bootimage.build.date=',
'ro.bootimage.build.date.utc=',
'ro.bootimage.build.fingerprint=',
'ro.build.id=',
'ro.build.display.id=',
'ro.build.version.incremental=',
'ro.build.date=',
'ro.build.date.utc=',
'ro.build.host=',
'ro.build.user=',
'ro.build.description=',
'ro.build.fingerprint=',
'ro.expect.recovery_id=',
'ro.vendor.build.date=',
'ro.vendor.build.date.utc=',
'ro.vendor.build.fingerprint=']
for line in original:
skip = False
for s in skipped:
if line.startswith(s):
skip = True
break
if not skip:
new.write(line)
def trim_install_recovery(original, new):
"""
Rewrite the install-recovery script to remove the hash of the recovery
partition.
"""
for line in original:
new.write(re.sub(r'[0-9a-f]{40}', '0'*40, line))
def sort_file(original, new):
"""
Sort the file. Some OTA metadata files are not in a deterministic order
currently.
"""
lines = original.readlines()
lines.sort()
for line in lines:
new.write(line)
# Map files to the functions that will modify them for diffing
REWRITE_RULES = {
'BOOT/RAMDISK/default.prop': rewrite_build_property,
'RECOVERY/RAMDISK/default.prop': rewrite_build_property,
'SYSTEM/build.prop': rewrite_build_property,
'VENDOR/build.prop': rewrite_build_property,
'SYSTEM/bin/install-recovery.sh': trim_install_recovery,
'META/boot_filesystem_config.txt': sort_file,
'META/filesystem_config.txt': sort_file,
'META/recovery_filesystem_config.txt': sort_file,
'META/vendor_filesystem_config.txt': sort_file,
}
@contextlib.contextmanager
def preprocess(name, filename):
"""
Optionally rewrite files before diffing them, to remove known-variable
information.
"""
if name in REWRITE_RULES:
with tempfile.NamedTemporaryFile() as newfp:
with open(filename, 'r') as oldfp:
REWRITE_RULES[name](oldfp, newfp)
newfp.flush()
yield newfp.name
else:
yield filename
def diff(name, file1, file2, out_file):
"""
Diff a file pair with diff, running preprocess() on the arguments first.
"""
with preprocess(name, file1) as f1:
with preprocess(name, file2) as f2:
proc = subprocess.Popen(['diff', f1, f2], stdout=subprocess.PIPE,
stderr=subprocess.STDOUT)
(stdout, _) = proc.communicate()
if proc.returncode == 0:
return
stdout = stdout.strip()
if stdout == 'Binary files %s and %s differ' % (f1, f2):
print("%s: Binary files differ" % name, file=out_file)
else:
for line in stdout.strip().split('\n'):
print("%s: %s" % (name, line), file=out_file)
def recursiveDiff(prefix, dir1, dir2, out_file):
"""
Recursively diff two directories, checking metadata then calling diff()
"""
list1 = sorted(os.listdir(dir1))
list2 = sorted(os.listdir(dir2))
for entry in list1:
name = os.path.join(prefix, entry)
name1 = os.path.join(dir1, entry)
name2 = os.path.join(dir2, entry)
if ignore(name):
continue
if entry in list2:
if os.path.islink(name1) and os.path.islink(name2):
link1 = os.readlink(name1)
link2 = os.readlink(name2)
if link1 != link2:
print("%s: Symlinks differ: %s vs %s" % (name, link1, link2),
file=out_file)
continue
elif os.path.islink(name1) or os.path.islink(name2):
print("%s: File types differ, skipping compare" % name, file=out_file)
continue
stat1 = os.stat(name1)
stat2 = os.stat(name2)
type1 = stat1.st_mode & ~0o777
type2 = stat2.st_mode & ~0o777
if type1 != type2:
print("%s: File types differ, skipping compare" % name, file=out_file)
continue
if stat1.st_mode != stat2.st_mode:
print("%s: Modes differ: %o vs %o" %
(name, stat1.st_mode, stat2.st_mode), file=out_file)
if os.path.isdir(name1):
recursiveDiff(name, name1, name2, out_file)
elif os.path.isfile(name1):
diff(name, name1, name2, out_file)
else:
print("%s: Unknown file type, skipping compare" % name, file=out_file)
else:
print("%s: Only in base package" % name, file=out_file)
for entry in list2:
name = os.path.join(prefix, entry)
name1 = os.path.join(dir1, entry)
name2 = os.path.join(dir2, entry)
if ignore(name):
continue
if entry not in list1:
print("%s: Only in new package" % name, file=out_file)
def main():
parser = argparse.ArgumentParser()
parser.add_argument('dir1', help='The base target files package (extracted)')
parser.add_argument('dir2', help='The new target files package (extracted)')
parser.add_argument('--output',
help='The output file, otherwise it prints to stdout')
args = parser.parse_args()
if args.output:
out_file = open(args.output, 'w')
else:
out_file = sys.stdout
recursiveDiff('', args.dir1, args.dir2, out_file)
if args.output:
out_file.close()
if __name__ == '__main__':
main()