[swarming] Add isolate driver.

tools/isolate_driver.py

+#!/usr/bin/env python
+# Copyright 2015 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Adaptor script called through build/isolate.gypi.
+
+Slimmed down version of chromium's isolate driver that doesn't process dynamic
+dependencies.
+"""
+
+import json
+import logging
+import os
+import subprocess
+import sys
+
+TOOLS_DIR = os.path.dirname(os.path.abspath(__file__))
+
+
+def prepare_isolate_call(args, output):
+  """Gathers all information required to run isolate.py later.
+
+  Dumps it as JSON to |output| file.
+  """
+  with open(output, 'wb') as f:
+    json.dump({
+      'args': args,
+      'dir': os.getcwd(),
+      'version': 1,
+    }, f, indent=2, sort_keys=True)
+
+
+def main():
+  logging.basicConfig(level=logging.ERROR, format='%(levelname)7s %(message)s')
+  if len(sys.argv) < 2:
+    print >> sys.stderr, 'Internal failure; mode required'
+    return 1
+  mode = sys.argv[1]
+  args = sys.argv[1:]
+  isolate = None
+  isolated = None
+  for i, arg in enumerate(args):
+    if arg == '--isolate':
+      isolate = i + 1
+    if arg == '--isolated':
+      isolated = i + 1
+  if not isolate or not isolated:
+    print >> sys.stderr, 'Internal failure'
+    return 1
+
+  # In 'prepare' mode just collect all required information for postponed
+  # isolated.py invocation later, store it in *.isolated.gen.json file.
+  if mode == 'prepare':
+    prepare_isolate_call(args[1:], args[isolated] + '.gen.json')
+    return 0
+
+  swarming_client = os.path.join(TOOLS_DIR, 'swarming_client')
+  sys.stdout.flush()
+  return subprocess.call(
+      [sys.executable, os.path.join(swarming_client, 'isolate.py')] + args)
+
+
+if __name__ == '__main__':
+  sys.exit(main())