MB: Add --isolate-map-file flag for overriding default isolate map.

tools/mb/mb.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.
 
 """MB - the Meta-Build wrapper around GYP and GN
 
 MB is a wrapper script for GYP and GN that can be used to generate build files
 for sets of canned configurations and analyze them.
 """
@@ skipping 27 matching lines @@
 def main(args):
   mbw = MetaBuildWrapper()
   return mbw.Main(args)
 
 
 class MetaBuildWrapper(object):
   def __init__(self):
     self.chromium_src_dir = CHROMIUM_SRC_DIR
     self.default_config = os.path.join(self.chromium_src_dir, 'tools', 'mb',
                                        'mb_config.pyl')
+    self.default_isolate_map = os.path.join(self.chromium_src_dir, 'testing',
+                                            'buildbot', 'gn_isolate_map.pyl')
     self.executable = sys.executable
     self.platform = sys.platform
     self.sep = os.sep
     self.args = argparse.Namespace()
     self.configs = {}
     self.masters = {}
     self.mixins = {}
 
   def Main(self, args):
     self.ParseArgs(args)
@@ skipping 20 matching lines @@
                         help='master name to look up config from')
       subp.add_argument('-c', '--config',
                         help='configuration to analyze')
       subp.add_argument('--phase',
                         help='optional phase name (used when builders '
                              'do multiple compiles with different '
                              'arguments in a single build)')
       subp.add_argument('-f', '--config-file', metavar='PATH',
                         default=self.default_config,
                         help='path to config file '
-                            '(default is //tools/mb/mb_config.pyl)')
+                             '(default is %(default)s)')
+      subp.add_argument('-i', '--isolate-map-file', metavar='PATH',
+                        default=self.default_isolate_map,
+                        help='path to isolate map file '
+                             '(default is %(default)s)')
       subp.add_argument('-g', '--goma-dir',
                         help='path to goma directory')
       subp.add_argument('--gyp-script', metavar='PATH',
                         default=self.PathJoin('build', 'gyp_chromium'),
                         help='path to gyp script relative to project root '
                              '(default is %(default)s)')
       subp.add_argument('--android-version-code',
                         help='Sets GN arg android_default_version_code and '
                              'GYP_DEFINE app_manifest_version_code')
       subp.add_argument('--android-version-name',
@@ skipping 20 matching lines @@
     subp.add_argument('output_path', nargs=1,
                       help='path to a file containing the output arguments '
                            'as a JSON object.')
     subp.set_defaults(func=self.CmdAnalyze)
 
     subp = subps.add_parser('export',
                             help='print out the expanded configuration for'
                                  'each builder as a JSON object')
     subp.add_argument('-f', '--config-file', metavar='PATH',
                       default=self.default_config,
-                      help='path to config file '
-                          '(default is //tools/mb/mb_config.pyl)')
+                      help='path to config file (default is %(default)s)')
     subp.add_argument('-g', '--goma-dir',
                       help='path to goma directory')
     subp.set_defaults(func=self.CmdExport)
 
     subp = subps.add_parser('gen',
                             help='generate a new set of build files')
     AddCommonOptions(subp)
     subp.add_argument('--swarming-targets-file',
                       help='save runtime dependencies for targets listed '
                            'in file.')
@@ skipping 55 matching lines @@
     subp.add_argument('extra_args', nargs='*',
                       help=('extra args to pass to the isolate to run. Use '
                             '"--" as the first arg if you need to pass '
                             'switches'))
     subp.set_defaults(func=self.CmdRun)
 
     subp = subps.add_parser('validate',
                             help='validate the config file')
     subp.add_argument('-f', '--config-file', metavar='PATH',
                       default=self.default_config,
-                      help='path to config file '
-                          '(default is //tools/mb/mb_config.pyl)')
+                      help='path to config file (default is %(default)s)')
     subp.set_defaults(func=self.CmdValidate)
 
     subp = subps.add_parser('audit',
                             help='Audit the config file to track progress')
     subp.add_argument('-f', '--config-file', metavar='PATH',
                       default=self.default_config,
-                      help='path to config file '
-                          '(default is //tools/mb/mb_config.pyl)')
+                      help='path to config file (default is %(default)s)')
     subp.add_argument('-i', '--internal', action='store_true',
                       help='check internal masters also')
     subp.add_argument('-m', '--master', action='append',
                       help='master to audit (default is all non-internal '
                            'masters in file)')
     subp.add_argument('-u', '--url-template', action='store',
                       default='https://build.chromium.org/p/'
                               '{master}/json/builders',
                       help='URL scheme for JSON APIs to buildbot '
                            '(default: %(default)s) ')
@@ skipping 438 matching lines @@
       contents = ast.literal_eval(self.ReadFile(self.args.config_file))
     except SyntaxError as e:
       raise MBErr('Failed to parse config file "%s": %s' %
                  (self.args.config_file, e))
 
     self.configs = contents['configs']
     self.masters = contents['masters']
     self.mixins = contents['mixins']
 
   def ReadIsolateMap(self):
-    return ast.literal_eval(self.ReadFile(self.PathJoin(
-        self.chromium_src_dir, 'testing', 'buildbot', 'gn_isolate_map.pyl')))
+    if not self.Exists(self.args.isolate_map_file):
+      raise MBErr('isolate map file not found at %s' %
+                  self.args.isolate_map_file)
+    try:
+      return ast.literal_eval(self.ReadFile(self.args.isolate_map_file))
+    except SyntaxError as e:
+      raise MBErr('Failed to parse isolate map file "%s": %s' %
+                  (self.args.isolate_map_file, e))
 
   def ConfigFromArgs(self):
     if self.args.config:
       if self.args.master or self.args.builder:
         raise MBErr('Can not specific both -c/--config and -m/--master or '
                     '-b/--builder')
 
       return self.args.config
 
     if not self.args.master or not self.args.builder:
@@ skipping 867 matching lines @@
   # Then check to see if the arg contains any metacharacters other than
   # double quotes; if it does, quote everything (including the double
   # quotes) for safety.
   if any(a in UNSAFE_FOR_CMD for a in arg):
     arg = ''.join('^' + a if a in ALL_META_CHARS else a for a in arg)
   return arg
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))