Less attempted magic in pulling toolchain

win_toolchain/get_toolchain_if_necessary.py

 #!/usr/bin/env python
 # Copyright 2013 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.
 
 """Downloads and unpacks a toolchain for building on Windows. The contents are
 matched by sha1 which will be updated when the toolchain is updated.
 
 Having a toolchain script in depot_tools means that it's not versioned
 directly with the source code. That is, if the toolchain is upgraded, but
@@ skipping 129 matching lines @@
 
 
 def CanAccessToolchainBucket():
   """Checks whether the user has access to gs://chrome-wintoolchain/."""
   gsutil = download_from_google_storage.Gsutil(
       download_from_google_storage.GSUTIL_DEFAULT_PATH, boto_path=None)
   code, _, _ = gsutil.check_call('ls', 'gs://chrome-wintoolchain/')
   return code == 0
 
 
-def ConfigureGsAccess():
-  """Starts the authentication flow for gs://, and confirms that it's
-  accessible after completion, or retries indefinitely.
+def RequestGsAuthentication():
+  """Requests that the user authenticate to be able to access gs:// as a
+  Googler. This allows much faster downloads, and pulling (old) toolchains
+  that match src/ revisions.
   """
-  while not CanAccessToolchainBucket():
-    print 'Access to gs://chrome-wintoolchain/ not configured.'
-    print '-----------------------------------------------------------------'
-    print
-    print 'You appear to be a Googler.'
-    print
-    print 'I\'m sorry for the hassle, but you need to do a one-time manual'
-    print 'authentication. Instructions will open in a new window. This is'
-    print 'a run of "gsutil config".'
-    print
-    print 'NOTE: Just press Enter when asked for a "project-id".'
-    print
-    print '-----------------------------------------------------------------'
-    print
-    sys.stdout.flush()
-    # gclient's buffering makes this hang if we're run from inside gclient
-    # as is typical. So, spawn a new window for the config prompt. :(
-    subprocess.check_call(
-        ['start', '/wait', 'cmd', '/c',
-         'download_from_google_storage', '--config'],
-        shell=True)
+  print 'Access to gs://chrome-wintoolchain/ not configured.'
+  print '-----------------------------------------------------------------'
+  print
+  print 'You appear to be a Googler.'
+  print
+  print 'I\'m sorry for the hassle, but you need to do a one-time manual'
+  print 'authentication. Please run:'
+  print
+  print '    download_from_google_storage --config'
+  print
+  print 'and follow the instructions. NOTE: Just press Enter when asked for'
+  print 'a "project-id".'
+  print
+  print '-----------------------------------------------------------------'
+  print
+  sys.stdout.flush()
+  sys.exit(1)
 
 
 def DelayBeforeRemoving(target_dir):
   """A grace period before deleting the out of date toolchain directory."""
   if (os.path.isdir(target_dir) and
       not bool(int(os.environ.get('CHROME_HEADLESS', '0')))):
     for i in range(9, 0, -1):
       sys.stdout.write(
               '\rRemoving old toolchain in %ds... (Ctrl-C to cancel)' % i)
       sys.stdout.flush()
       time.sleep(1)
     print
 
 
 def main():
   if not sys.platform.startswith(('cygwin', 'win32')):
     return 0
 
   parser = optparse.OptionParser(description=sys.modules[__name__].__doc__)
   parser.add_option('--output-json', metavar='FILE',
                     help='write information about toolchain to FILE')
   options, args = parser.parse_args()
 
   # We assume that the Pro hash is the first one.
   desired_hashes = args
+  if len(desired_hashes) == 0:
+    sys.exit('Desired hashes are required.')
 
   # Move to depot_tools\win_toolchain where we'll store our files, and where
   # the downloader script is.
   os.chdir(os.path.normpath(os.path.join(BASEDIR)))
   toolchain_dir = '.'
   target_dir = os.path.normpath(os.path.join(toolchain_dir, 'vs2013_files'))
 
   # If the current hash doesn't match what we want in the file, nuke and pave.
   # Typically this script is only run when the .sha1 one file is updated, but
   # directly calling "gclient runhooks" will also run it, so we cache
   # based on timestamps to make that case fast.
   current_hash = CalculateHash(target_dir)
   if current_hash not in desired_hashes:
     should_use_gs = False
-    if (CanAccessToolchainBucket() or
-        HaveSrcInternalAccess() or
-        LooksLikeGoogler()):
+    if HaveSrcInternalAccess() or LooksLikeGoogler():
       should_use_gs = True
-      ConfigureGsAccess()
+      if not CanAccessToolchainBucket():
+        RequestGsAuthentication()
     print('Windows toolchain out of date or doesn\'t exist, updating (%s)...' %
           ('Pro' if should_use_gs else 'Express'))
     print('  current_hash: %s' % current_hash)
     print('  desired_hashes: %s' % ', '.join(desired_hashes))
     sys.stdout.flush()
     DelayBeforeRemoving(target_dir)
     # This stays resident and will make the rmdir below fail.
     with open(os.devnull, 'wb') as nul:
       subprocess.call(['taskkill', '/f', '/im', 'mspdbsrv.exe'],
                       stdin=nul, stdout=nul, stderr=nul)
@@ skipping 19 matching lines @@
 
   if options.output_json:
     shutil.copyfile(os.path.join(target_dir, '..', 'data.json'),
                     options.output_json)
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())