| # Copyright 2014 The Chromium Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| import logging |
| import subprocess |
| import sys |
| |
| from hashlib import sha256 |
| from os.path import basename, realpath |
| |
| _logging = logging.getLogger() |
| |
| # Based on/taken from |
| # http://code.activestate.com/recipes/578231-probably-the-fastest-memoization-decorator-in-the-/ |
| # (with cosmetic changes). |
| def _memoize(f): |
| """Memoization decorator for a function taking a single argument.""" |
| class Memoize(dict): |
| def __missing__(self, key): |
| rv = self[key] = f(key) |
| return rv |
| return Memoize().__getitem__ |
| |
| @_memoize |
| def _file_hash(filename): |
| """Returns a string representing the hash of the given file.""" |
| _logging.debug("Hashing %s ...", filename) |
| rv = subprocess.check_output(['sha256sum', '-b', filename]).split(None, 1)[0] |
| _logging.debug(" => %s", rv) |
| return rv |
| |
| @_memoize |
| def _get_dependencies(filename): |
| """Returns a list of filenames for files that the given file depends on.""" |
| _logging.debug("Getting dependencies for %s ...", filename) |
| lines = subprocess.check_output(['ldd', filename]).splitlines() |
| rv = [] |
| for line in lines: |
| i = line.find('/') |
| if i < 0: |
| _logging.debug(" => no file found in line: %s", line) |
| continue |
| rv.append(line[i:].split(None, 1)[0]) |
| _logging.debug(" => %s", rv) |
| return rv |
| |
| def transitive_hash(filename): |
| """Returns a string that represents the "transitive" hash of the given |
| file. The transitive hash is a hash of the file and all the shared libraries |
| on which it depends (done in an order-independent way).""" |
| hashes = set() |
| to_hash = [filename] |
| while to_hash: |
| current_filename = realpath(to_hash.pop()) |
| current_hash = _file_hash(current_filename) |
| if current_hash in hashes: |
| _logging.debug("Already seen %s (%s) ...", current_filename, current_hash) |
| continue |
| _logging.debug("Haven't seen %s (%s) ...", current_filename, current_hash) |
| hashes.add(current_hash) |
| to_hash.extend(_get_dependencies(current_filename)) |
| return sha256('|'.join(sorted(hashes))).hexdigest() |
| |
| def main(argv): |
| logging.basicConfig() |
| # Uncomment to debug: |
| # _logging.setLevel(logging.DEBUG) |
| |
| if len(argv) < 2: |
| print """\ |
| Usage: %s [file] ... |
| |
| Prints the \"transitive\" hash of each (executable) file. The transitive |
| hash is a hash of the file and all the shared libraries on which it |
| depends (done in an order-independent way).""" % basename(argv[0]) |
| return 0 |
| |
| rv = 0 |
| for filename in argv[1:]: |
| try: |
| print transitive_hash(filename), filename |
| except: |
| print "ERROR", filename |
| rv = 1 |
| return rv |
| |
| if __name__ == '__main__': |
| sys.exit(main(sys.argv)) |