Added separate checkout and config file generation to bisect script

build/util/run-bisect-perf-regression.py

Index: build/util/run-bisect-perf-regression.py
diff --git a/build/util/run-bisect-perf-regression.py b/build/util/run-bisect-perf-regression.py
new file mode 100755
index 0000000000000000000000000000000000000000..56277dde9841882c5ca96a30b25aa5388b55f589
--- /dev/null
+++ b/build/util/run-bisect-perf-regression.py
@@ -0,0 +1,99 @@
+#!/usr/bin/env python
+# Copyright (c) 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.
+
+"""Run Performance Test Bisect Tool
+
+This script is used by a trybot to run the src/tools/bisect-perf-regression.py
+script with the parameters specified in run-bisect-perf-regression.cfg. It will
+check out a copy of the depot in a subdirectory 'bisect' of the working
+directory provided, and run the bisect-perf-regression.py script there.
+
+"""
+
+import imp
+import optparse
+import os
+import subprocess
+import sys
+

[Mike Stip (use stip instead), 2013/02/20 01:04:44]

extra line here

[shatch, 2013/02/20 19:34:09]

Done.

+def LoadConfigFile():
+  """Attempts to load the file 'run-bisect-perf-regression.cfg' as a module
+  and grab the global config dict.
+
+  Returns:
+    The config dict which should be formatted as follows:
+    {'command': string, 'good_revision': string, 'bad_revision': string
+     'metric': string}.
+    Returns None on failure.
+  """
+  try:
+    cfg_file = imp.load_source('config', 'run-bisect-perf-regression.cfg')

[Mike Stip (use stip instead), 2013/02/20 01:04:44]

I'm not sure if imp.load_source() is needed here. We have stuff in
tools/build/scripts/common/ that loads config files and returns dictionaries.
Right now they're tailored to work with slaves.cfg, but there is a CL out to
have them return the entire dict of whatever is created in the file.

See ParsePythonCFG() in
https://chromiumcodereview.appspot.com/12300004/diff/3001/scripts/common/chro...

+
+    return cfg_file.config
+  except (KeyError, TypeError, IOError):
+    return None
+
+
+def RunBisectionScript(config, working_directory):
+  """Attempts to execute src/tools/bisect-perf-regression.py with the parameters
+  passed in.
+
+  Args:
+    config: A dict containing the parameters to pass to the script.
+
+  Returns:
+    0 on success, otherwise 1.
+  """
+
+  cmd = [os.path.join('..', '..', 'tools', 'bisect-perf-regression.py'),
+         '-c', config['command'],
+         '-g', config['good_revision'],
+         '-b', config['bad_revision'],
+         '-m', config['metric'],
+         '--working_directory', working_directory,
+         '--output_buildbot_annotations']
+
+  return_code = subprocess.call(cmd)
+
+  if return_code:
+    print 'Error: bisect-perf-regression.py returned with error %d' %\
+        return_code
+    print
+    return 1
+
+  return 0
+
+
+def main():
+
+  usage = ('%prog [options] [-- chromium-options]\n'
+           'Used by a trybot to run the bisection script using the parameters'
+           ' provided in the run-bisect-perf-regression.cfg file.')
+
+  parser = optparse.OptionParser(usage=usage)
+  parser.add_option('-w', '--working_directory',
+                    type='str',
+                    help='A working directory to supply to the bisection '
+                    'script, which will use it as the location to checkout '
+                    'a copy of the chromium depot.')
+  (opts, args) = parser.parse_args()
+
+  if not opts.working_directory:
+    print 'Error: missing required parameter: --working_directory'
+    print
+    parser.print_help()
+    return 1
+
+  config = LoadConfigFile()
+  if not config:
+    print 'Error: Could not load config file.'
+    print
+    return 1
+
+  return RunBisectionScript(config, opts.working_directory)
+
+
+if __name__ == '__main__':
+  sys.exit(main())