Move toolchain update control into src, but keep download logic in depot_tools

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 11 matching lines @@
 major revisions. This script calls a subscript (currently, toolchain2013.py)
 to do the main work. It is expected that toolchain2013.py will always be able
 to acquire/build the most current revision of a VS2013-based toolchain. In the
 future when a hypothetical VS2015 is released, the 2013 script will be
 maintained, and a new 2015 script would be added.
 """
 
 import ctypes.wintypes
 import hashlib
 import json
+import optparse
 import os
+import shutil
 import subprocess
 import sys
 import time
 
 
 BASEDIR = os.path.dirname(os.path.abspath(__file__))
 
 
 GetFileAttributes = ctypes.windll.kernel32.GetFileAttributesW
 GetFileAttributes.argtypes = (ctypes.wintypes.LPWSTR,)
@@ skipping 95 matching lines @@
               '\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
 
-  if len(sys.argv) != 1:
-    print >> sys.stderr, 'Unexpected arguments.'
-    return 1
+  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()
+
+  desired_hashes = set(args)
 
   # 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'))
 
-  sha1path = os.path.join(toolchain_dir, 'toolchain_vs2013.hash')
-  desired_hashes = set()
-  if os.path.isfile(sha1path):
-    with open(sha1path, 'rb') as f:
-      desired_hashes = set(f.read().strip().splitlines())
-
   # 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_get_pro = (os.path.isfile(os.path.join(BASEDIR, '.vspro')) or
                       HaveSrcInternalAccess())
     print('Windows toolchain out of date or doesn\'t exist, updating (%s)...' %
           ('Pro' if should_get_pro else 'Express'))
@@ skipping 14 matching lines @@
     subprocess.check_call(args)
     current_hash = CalculateHash(target_dir)
     if current_hash not in desired_hashes:
       print >> sys.stderr, (
           'Got wrong hash after pulling a new toolchain. '
           'Wanted one of \'%s\', got \'%s\'.' % (
               desired_hashes, current_hash))
       return 1
     SaveTimestampsAndHash(target_dir, current_hash)
 
+  if options.output_json:
+    shutil.copyfile(os.path.join(target_dir, 'data.json'), options.output_json)
+
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())