NaCl: Allow download_nacl_irt.py to be usefully invoked with no arguments

build/download_nacl_irt.py

 #!/usr/bin/env python
 # Copyright (c) 2011 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 hashlib
 import optparse
 import os
 import urllib2
 import sys
@@ skipping 101 matching lines @@
       break
     except urllib2.HTTPError, exn:
       if exn.getcode() == 404:
         raise
       sys.stdout.write('Download failed with error %r.  Retrying...\n'
                        % str(exn))
       sys.stdout.flush()
       time.sleep(1)
 
 
+def EvalDepsFile(path):
+  scope = {'Var': lambda name: scope['vars'][name]}
+  execfile(path, {}, scope)
+  return scope
+
+
 def Main():
   parser = optparse.OptionParser()
   parser.add_option(
       '--base_url', dest='base_url',
       # For a view of this site that includes directory listings, see:
       # http://gsdview.appspot.com/nativeclient-archive2/
       # (The trailing slash is required.)
       default=('http://commondatastorage.googleapis.com/'
                'nativeclient-archive2/irt'),
       help='Base URL from which to download.')
   parser.add_option(
       '--nacl_revision', dest='nacl_revision',
       help='Download an IRT binary that was built from this '
         'SVN revision of Native Client.')
   parser.add_option(
       '--file_hash', dest='file_hashes', action='append', nargs=2, default=[],
       metavar='ARCH HASH',
       help='ARCH gives the name of the architecture (e.g. "x86_32") for '
         'which to download an IRT binary.  '
         'HASH gives the expected SHA1 hash of the file.')
   options, args = parser.parse_args()
   if len(args) != 0:
     parser.error('Unexpected arguments: %r' % args)
 
+  if options.nacl_revision is None and len(options.file_hashes) == 0:
+    # The script must have been invoked directly with no arguments,
+    # rather than being invoked by gclient.  In this case, read the
+    # DEPS file ourselves rather than having gclient pass us values
+    # from DEPS.
+    deps_data = EvalDepsFile(os.path.join('src', 'DEPS'))

[Paweł Hajdan Jr., 2011/05/09 14:08:48]

This is duplicating some gclient code and it's relying on something that may be
considered an implementation detail of gclient. How about switching things
entirely to this file, i.e. remove the revision numbers and hashes from DEPS and
moving it so some other file where you can trivially parse them (it might even
be this file).

Then you can get rid of the conditional logic, and make the gclient hook run
this script without parameters.

+    options.nacl_revision = deps_data['vars']['nacl_revision']
+    options.file_hashes = [
+        ('x86_32', deps_data['vars']['nacl_irt_hash_x86_32']),
+        ('x86_64', deps_data['vars']['nacl_irt_hash_x86_64']),
+        ]
+
   nacl_dir = os.path.join('src', 'native_client')
   if not os.path.exists(nacl_dir):
     # If "native_client" is not present, this might be because the
     # developer has put '"src/native_client": None' in their
     # '.gclient' file, because they don't want to build Chromium with
     # Native Client support.  So don't create 'src/native_client',
     # because that would interfere with checking it out from SVN
     # later.
     sys.stdout.write(
         'The directory %r does not exist: skipping downloading binaries '
@@ skipping 22 matching lines @@
 
   if len(new_deps) > 0:
     sys.stdout.write('\nIf you have changed nacl_revision, the DEPS file '
                      'probably needs to be updated with the following:\n%s\n'
                      % ''.join(new_deps))
     sys.exit(1)
 
 
 if __name__ == '__main__':
   Main()