Replace usage of md5 with sha256 for generation of mojo app ids.

sky/tools/mojo_cache_linker.py

 #!/usr/bin/env python
 # Copyright 2015 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 argparse
 import logging
 import os
 import sys
 import subprocess
@@ skipping 26 matching lines @@
     except:
         return None
     return cache.get(path)
 
 
 def compute_path_to_app_id_map(paths, cache, cache_mtime):
     path_to_app_id_map = {}
     for path in paths:
         app_id = get_cached_app_id(path, cache, cache_mtime)
         if not app_id:
-            logging.info('md5sum %s' % path)
+            logging.info('sha256sum %s' % path)
             # Example output:
             # f82a3551478a9a0e010adccd675053b9 png_viewer.mojo
-            output = subprocess.check_output(['md5sum', path])
+            output = subprocess.check_output(['sha256sum', path])
             app_id = output.strip().split()[0]
         path_to_app_id_map[path] = app_id
     return path_to_app_id_map
 
 
 def read_app_id_cache(cache_path):
     try:
         with open(cache_path, 'r') as cache_file:
             return json.load(cache_file), os.path.getmtime(cache_path)
     except:
@@ skipping 10 matching lines @@
 
 
 # TODO(eseidel): Share logic with tools/android_stack_parser/stack
 def main():
     logging.basicConfig(level=logging.WARN)
     parser = argparse.ArgumentParser(
         description='Builds a directory of app_id symlinks to symbols'
         ' to match expected dlopen names from mojo_shell\'s NetworkLoader.')
     parser.add_argument('links_dir', type=str)
     parser.add_argument('build_dir', type=str)
+    parser.add_argument('-f', '--force', action='store_true')
+    parser.add_argument('-v', '--verbose', action='store_true')
     args = parser.parse_args()
 
+    if args.verbose:
+        logging.getLogger().setLevel(logging.INFO)
+
     if not os.path.isdir(args.links_dir):
         logging.fatal('links_dir: %s is not a directory' % args.links_dir)
         sys.exit(1)
 
     # Some of the .so files are 100s of megabytes.  Cache the md5s to save time.
     cache_path = os.path.join(args.build_dir, '.app_id_cache')
     cache, cache_mtime = read_app_id_cache(cache_path)
+    if args.force:
+        cache_mtime = None
 
     paths = library_paths(args.build_dir)
     path_to_app_id_map = compute_path_to_app_id_map(list(paths),
         cache, cache_mtime)
 
     # The cache contains unmodified app-ids.
     write_app_id_cache(cache_path, path_to_app_id_map)
 
     for path, app_id in path_to_app_id_map.items():
         basename = os.path.basename(path)
@@ skipping 13 matching lines @@
 
         if os.path.lexists(link_path):
             logging.debug('link already exists %s, replacing' % path)
             os.unlink(link_path)
 
         os.symlink(path, link_path)
 
 
 if __name__ == '__main__':
     main()