Add tool to diff two target files packages
This tool will help identify unexpected differences between two target
files packages. Expected changes (build number / date) are hidden, along
with known bugs.
It ignores anything that is just packaging for other files that are
already being diffed, like the recovery patching, and all of IMAGES/*
Bug 25372309
Change-Id: I4641754dd5dfbdfd3a89d8fa5262b9a9595e8e9c
diff --git a/tools/target_files_diff.py b/tools/target_files_diff.py
new file mode 100755
index 0000000..010ea84
--- /dev/null
+++ b/tools/target_files_diff.py
@@ -0,0 +1,224 @@
+#!/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 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/24201956 .art/.oat/.odex files are different with every build
+ if name.endswith('.art') or name.endswith('.oat') or name.endswith('.odex'):
+ return True
+ # b/25348136 libpac.so changes with every build
+ if name in ['SYSTEM/lib/libpac.so',
+ 'SYSTEM/lib64/libpac.so']:
+ 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.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):
+ """
+ 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, ignore) = 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)
+ else:
+ for line in stdout.strip().split('\n'):
+ print("%s: %s" % (name, line))
+
+def recursiveDiff(prefix, dir1, dir2):
+ """
+ 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):
+ if 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))
+ else:
+ print("%s: File types differ, skipping compare" % name)
+ continue
+
+ stat1 = os.stat(name1)
+ stat2 = os.stat(name2)
+ type1 = stat1.st_mode & ~0777
+ type2 = stat2.st_mode & ~0777
+
+ if type1 != type2:
+ print("%s: File types differ, skipping compare" % name)
+ continue
+
+ if stat1.st_mode != stat2.st_mode:
+ print("%s: Modes differ: %o vs %o" % (name, stat1.st_mode, stat2.st_mode))
+
+ if os.path.isdir(name1):
+ recursiveDiff(name, name1, name2)
+ elif os.path.isfile(name1):
+ diff(name, name1, name2)
+ else:
+ print("%s: Unknown file type, skipping compare" % name)
+ else:
+ print("%s: Only in base package" % name)
+
+ 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)
+
+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)')
+ args = parser.parse_args()
+
+ recursiveDiff('', args.dir1, args.dir2)
+
+if __name__ == '__main__':
+ main()