path: root/webkit/tools/layout_tests/run_webkit_tests.py

#!/usr/bin/env python
# Copyright (c) 2006-2009 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 layout tests using the test_shell.

This is a port of the existing webkit test script run-webkit-tests.

The TestRunner class runs a series of tests (TestType interface) against a set
of test files.  If a test file fails a TestType, it returns a list TestFailure
objects to the TestRunner.  The TestRunner then aggregates the TestFailures to
create a final report.

This script reads several files, if they exist in the test_lists subdirectory
next to this script itself.  Each should contain a list of paths to individual
tests or entire subdirectories of tests, relative to the outermost test
directory.  Entire lines starting with '//' (comments) will be ignored.

For details of the files' contents and purposes, see test_lists/README.
"""

import errno
import glob
import logging
import math
import optparse
import os
import Queue
import random
import re
import shutil
import subprocess
import sys
import time
import traceback

from layout_package import apache_http_server
from layout_package import test_expectations
from layout_package import http_server
from layout_package import json_results_generator
from layout_package import metered_stream
from layout_package import path_utils
from layout_package import platform_utils
from layout_package import test_failures
from layout_package import test_shell_thread
from layout_package import test_files
from layout_package import websocket_server
from test_types import fuzzy_image_diff
from test_types import image_diff
from test_types import test_type_base
from test_types import text_diff

sys.path.append(path_utils.PathFromBase('third_party'))
import simplejson

TestExpectationsFile = test_expectations.TestExpectationsFile

class TestInfo:
  """Groups information about a test for easy passing of data."""
  def __init__(self, filename, timeout):
    """Generates the URI and stores the filename and timeout for this test.
    Args:
      filename: Full path to the test.
      timeout: Timeout for running the test in TestShell.
      """
    self.filename = filename
    self.uri = path_utils.FilenameToUri(filename)
    self.timeout = timeout
    expected_hash_file = path_utils.ExpectedFilename(filename, '.checksum')
    try:
      self.image_hash = open(expected_hash_file, "r").read()
    except IOError, e:
      if errno.ENOENT != e.errno:
        raise
      self.image_hash = None


class ResultSummary(object):
  """A class for partitioning the test results we get into buckets.

  This class is basically a glorified struct and it's private to this file
  so we don't bother with any information hiding."""
  def __init__(self, expectations, test_files):
    self.total = len(test_files)
    self.remaining = self.total
    self.expectations = expectations
    self.expected = 0
    self.unexpected = 0
    self.tests_by_expectation = {}
    self.tests_by_timeline = {}
    self.results = {}
    self.unexpected_results = {}
    self.failures = {}
    self.tests_by_expectation[test_expectations.SKIP] = set()
    for expectation in TestExpectationsFile.EXPECTATIONS.values():
      self.tests_by_expectation[expectation] = set()
    for timeline in TestExpectationsFile.TIMELINES.values():
      self.tests_by_timeline[timeline] = expectations.GetTestsWithTimeline(
          timeline)

  def Add(self, test, failures, result):
    """Add a result into the appropriate bin.

    Args:
      test: test file name
      failures: list of failure objects from test execution
      result: result of test (PASS, IMAGE, etc.)."""

    self.tests_by_expectation[result].add(test)
    self.results[test] = result
    self.remaining -= 1
    if len(failures):
      self.failures[test] = failures
    if self.expectations.MatchesAnExpectedResult(test, result):
      self.expected += 1
    else:
      self.unexpected_results[test] = result
      self.unexpected += 1



class TestRunner:
  """A class for managing running a series of tests on a series of test
  files."""

  HTTP_SUBDIR = os.sep.join(['', 'http', ''])
  WEBSOCKET_SUBDIR = os.sep.join(['', 'websocket', ''])

  # The per-test timeout in milliseconds, if no --time-out-ms option was given
  # to run_webkit_tests. This should correspond to the default timeout in
  # test_shell.exe.
  DEFAULT_TEST_TIMEOUT_MS = 6 * 1000

  NUM_RETRY_ON_UNEXPECTED_FAILURE = 1

  def __init__(self, options, meter):
    """Initialize test runner data structures.

    Args:
      options: a dictionary of command line options
      meter: a MeteredStream object to record updates to.
    """
    self._options = options
    self._meter = meter

    if options.use_apache:
      self._http_server = apache_http_server.LayoutTestApacheHttpd(
          options.results_directory)
    else:
      self._http_server = http_server.Lighttpd(options.results_directory)

    self._shardable_directories = ['chrome', 'LayoutTests', 'pending', 'fast',
        'svg', 'loader']

    # The http tests are very stable on mac/linux.
    # TODO(ojan): Make the http server on Windows be apache so we can turn
    # shard the http tests there as well. Switching to apache is what made them
    # stable on linux/mac.
    if sys.platform in ('darwin', 'linux2'):
      self._shardable_directories.extend(['http', 'tests'])

    self._websocket_server = websocket_server.PyWebSocket(
        options.results_directory)
    # disable wss server. need to install pyOpenSSL on buildbots.
    # self._websocket_secure_server = websocket_server.PyWebSocket(
    #        options.results_directory, use_tls=True, port=9323)

    # a list of TestType objects
    self._test_types = []

    # a set of test files, and the same tests as a list
    self._test_files = set()
    self._test_files_list = None
    self._file_dir = path_utils.GetAbsolutePath(os.path.dirname(sys.argv[0]))
    self._result_queue = Queue.Queue()

  def __del__(self):
    logging.debug("flushing stdout")
    sys.stdout.flush()
    logging.debug("flushing stderr")
    sys.stderr.flush()
    logging.debug("stopping http server")
    # Stop the http server.
    self._http_server.Stop()
    # Stop the Web Socket / Web Socket Secure servers.
    self._websocket_server.Stop()
    # self._websocket_secure_server.Stop()

  def GatherFilePaths(self, paths):
    """Find all the files to test.

    Args:
      paths: a list of globs to use instead of the defaults."""
    self._test_files = test_files.GatherTestFiles(paths)

  def ParseExpectations(self, platform, is_debug_mode):
    """Parse the expectations from the test_list files and return a data
    structure holding them. Throws an error if the test_list files have invalid
    syntax.
    """
    if self._options.lint_test_files:
      test_files = None
    else:
      test_files = self._test_files

    try:
      self._expectations = test_expectations.TestExpectations(test_files,
          self._file_dir, platform, is_debug_mode,
          self._options.lint_test_files)
      return self._expectations
    except Exception, err:
      if self._options.lint_test_files:
        print str(err)
      else:
        raise err

  def PrepareListsAndPrintOutput(self, write):
    """Create appropriate subsets of test lists and returns a ResultSummary
    object. Also prints expected test counts.

    Args:
      write: A callback to write info to (e.g., a LoggingWriter) or
         sys.stdout.write.
    """

    # Remove skipped - both fixable and ignored - files from the
    # top-level list of files to test.
    num_all_test_files = len(self._test_files)
    write("Found:  %d tests" % (len(self._test_files)))
    skipped = set()
    if num_all_test_files > 1 and not self._options.force:
      skipped = self._expectations.GetTestsWithResultType(
                     test_expectations.SKIP)
      self._test_files -= skipped

    # Create a sorted list of test files so the subset chunk, if used, contains
    # alphabetically consecutive tests.
    self._test_files_list = list(self._test_files)
    if self._options.randomize_order:
      random.shuffle(self._test_files_list)
    else:
      self._test_files_list.sort(self.TestFilesSort)

    # If the user specifies they just want to run a subset of the tests,
    # just grab a subset of the non-skipped tests.
    if self._options.run_chunk or self._options.run_part:
      chunk_value = self._options.run_chunk or self._options.run_part
      test_files = self._test_files_list
      try:
        (chunk_num, chunk_len) = chunk_value.split(":")
        chunk_num = int(chunk_num)
        assert(chunk_num >= 0)
        test_size = int(chunk_len)
        assert(test_size > 0)
      except:
        logging.critical("invalid chunk '%s'" % chunk_value)
        sys.exit(1)

      # Get the number of tests
      num_tests = len(test_files)

      # Get the start offset of the slice.
      if self._options.run_chunk:
        chunk_len = test_size
        # In this case chunk_num can be really large. We need to make the
        # slave fit in the current number of tests.
        slice_start = (chunk_num * chunk_len) % num_tests
      else:
        # Validate the data.
        assert(test_size <= num_tests)
        assert(chunk_num <= test_size)

        # To count the chunk_len, and make sure we don't skip some tests, we
        # round to the next value that fits exacly all the parts.
        rounded_tests = num_tests
        if rounded_tests % test_size != 0:
          rounded_tests = num_tests + test_size - (num_tests % test_size)

        chunk_len = rounded_tests / test_size
        slice_start = chunk_len * (chunk_num - 1)
        # It does not mind if we go over test_size.

      # Get the end offset of the slice.
      slice_end = min(num_tests, slice_start + chunk_len)

      files = test_files[slice_start:slice_end]

      tests_run_msg = 'Running: %d tests (chunk slice [%d:%d] of %d)' % (
          (slice_end - slice_start), slice_start, slice_end, num_tests)
      write(tests_run_msg)

      # If we reached the end and we don't have enough tests, we run some
      # from the beginning.
      if self._options.run_chunk and (slice_end - slice_start < chunk_len):
        extra = 1 + chunk_len - (slice_end - slice_start)
        extra_msg = '   last chunk is partial, appending [0:%d]' % extra
        write(extra_msg)
        tests_run_msg += "\n" + extra_msg
        files.extend(test_files[0:extra])
      tests_run_filename = os.path.join(self._options.results_directory,
                                        "tests_run.txt")
      tests_run_file = open(tests_run_filename, "w")
      tests_run_file.write(tests_run_msg + "\n")
      tests_run_file.close()

      len_skip_chunk = int(len(files) * len(skipped) /
                           float(len(self._test_files)))
      skip_chunk_list = list(skipped)[0:len_skip_chunk]
      skip_chunk = set(skip_chunk_list)

      # Update expectations so that the stats are calculated correctly.
      # We need to pass a list that includes the right # of skipped files
      # to ParseExpectations so that ResultSummary() will get the correct
      # stats. So, we add in the subset of skipped files, and then subtract
      # them back out.
      self._test_files_list = files + skip_chunk_list
      self._test_files = set(self._test_files_list)

      self._expectations = self.ParseExpectations(
          path_utils.PlatformName(), options.target == 'Debug')

      self._test_files = set(files)
      self._test_files_list = files
    else:
      skip_chunk = skipped

    result_summary = ResultSummary(self._expectations,
                                   self._test_files | skip_chunk)
    self._PrintExpectedResultsOfType(write, result_summary,
        test_expectations.PASS, "passes")
    self._PrintExpectedResultsOfType(write, result_summary,
        test_expectations.FAIL, "failures")
    self._PrintExpectedResultsOfType(write, result_summary,
        test_expectations.FLAKY, "flaky")
    self._PrintExpectedResultsOfType(write, result_summary,
        test_expectations.SKIP, "skipped")


    if self._options.force:
      write('Running all tests, including skips (--force)')
    else:
      # Note that we don't actually run the skipped tests (they were
      # subtracted out of self._test_files, above), but we stub out the
      # results here so the statistics can remain accurate.
      for test in skip_chunk:
        result_summary.Add(test, [], test_expectations.SKIP)
    write("")

    return result_summary

  def AddTestType(self, test_type):
    """Add a TestType to the TestRunner."""
    self._test_types.append(test_type)

  # We sort the tests so that tests using the http server will run first.  We
  # are seeing some flakiness, maybe related to apache getting swapped out,
  # slow, or stuck after not serving requests for a while.
  def TestFilesSort(self, x, y):
    """Sort with http tests always first."""
    x_is_http = x.find(self.HTTP_SUBDIR) >= 0
    y_is_http = y.find(self.HTTP_SUBDIR) >= 0
    if x_is_http != y_is_http:
      return cmp(y_is_http, x_is_http)
    return cmp(x, y)

  def _GetDirForTestFile(self, test_file):
    """Returns the highest-level directory by which to shard the given test
    file."""
    # TODO(ojan): See if we can grab the lowest level directory. That will
    # provide better parallelization. We should at least be able to do so
    # for some directories (e.g. LayoutTests/dom).
    index = test_file.rfind(os.sep + 'LayoutTests' + os.sep)
    if index is -1:
      index = test_file.rfind(os.sep + 'chrome' + os.sep)

    test_file = test_file[index + 1:]
    test_file_parts = test_file.split(os.sep, 1)
    directory = test_file_parts[0]
    test_file = test_file_parts[1]

    return_value = directory
    while (directory in self._shardable_directories and
           test_file.find(os.sep) >= 0):
      test_file_parts = test_file.split(os.sep, 1)
      directory = test_file_parts[0]
      return_value = os.path.join(return_value, directory)
      test_file = test_file_parts[1]

    return return_value

  def _GetTestInfoForFile(self, test_file):
    """Returns the appropriate TestInfo object for the file. Mostly this is used
    for looking up the timeout value (in ms) to use for the given test."""
    if self._expectations.HasModifier(test_file, test_expectations.SLOW):
      return TestInfo(test_file, self._options.slow_time_out_ms)
    return TestInfo(test_file, self._options.time_out_ms)

  def _GetTestFileQueue(self, test_files):
    """Create the thread safe queue of lists of (test filenames, test URIs)
    tuples. Each TestShellThread pulls a list from this queue and runs those
    tests in order before grabbing the next available list.

    Shard the lists by directory. This helps ensure that tests that depend
    on each other (aka bad tests!) continue to run together as most
    cross-tests dependencies tend to occur within the same directory.

    Return:
      The Queue of lists of TestInfo objects.
    """

    if self._options.experimental_fully_parallel:
      filename_queue = Queue.Queue()
      for test_file in test_files:
       filename_queue.put(('.', [self._GetTestInfoForFile(test_file)]))
      return filename_queue

    tests_by_dir = {}
    for test_file in test_files:
      directory = self._GetDirForTestFile(test_file)
      tests_by_dir.setdefault(directory, [])
      tests_by_dir[directory].append(self._GetTestInfoForFile(test_file))

    # Sort by the number of tests in the dir so that the ones with the most
    # tests get run first in order to maximize parallelization. Number of tests
    # is a good enough, but not perfect, approximation of how long that set of
    # tests will take to run. We can't just use a PriorityQueue until we move
    # to Python 2.6.
    test_lists = []
    http_tests = None
    for directory in tests_by_dir:
      test_list = tests_by_dir[directory]
      # Keep the tests in alphabetical order.
      # TODO: Remove once tests are fixed so they can be run in any order.
      test_list.reverse()
      test_list_tuple = (directory, test_list)
      if directory == 'LayoutTests' + os.sep + 'http':
        http_tests = test_list_tuple
      else:
        test_lists.append(test_list_tuple)
    test_lists.sort(lambda a, b: cmp(len(b[1]), len(a[1])))

    # Put the http tests first. There are only a couple hundred of them, but
    # each http test takes a very long time to run, so sorting by the number
    # of tests doesn't accurately capture how long they take to run.
    if http_tests:
      test_lists.insert(0, http_tests)

    filename_queue = Queue.Queue()
    for item in test_lists:
      filename_queue.put(item)
    return filename_queue

  def _GetTestShellArgs(self, index):
    """Returns the tuple of arguments for tests and for test_shell."""
    shell_args = []
    test_args = test_type_base.TestArguments()
    if not self._options.no_pixel_tests:
      png_path = os.path.join(self._options.results_directory,
                              "png_result%s.png" % index)
      shell_args.append("--pixel-tests=" + png_path)
      test_args.png_path = png_path

    test_args.new_baseline = self._options.new_baseline

    test_args.show_sources = self._options.sources

    if self._options.startup_dialog:
      shell_args.append('--testshell-startup-dialog')

    if self._options.gp_fault_error_box:
      shell_args.append('--gp-fault-error-box')

    return (test_args, shell_args)

  def _ContainWebSocketTest(self, test_files):
    if not test_files:
      return False
    for test_file in test_files:
      if test_file.find(self.WEBSOCKET_SUBDIR) >= 0:
        return True
    return False

  def _InstantiateTestShellThreads(self, test_shell_binary, test_files):
    """Instantitates and starts the TestShellThread(s).

    Return:
      The list of threads.
    """
    test_shell_command = [test_shell_binary]

    if self._options.wrapper:
      # This split() isn't really what we want -- it incorrectly will
      # split quoted strings within the wrapper argument -- but in
      # practice it shouldn't come up and the --help output warns
      # about it anyway.
      test_shell_command = self._options.wrapper.split() + test_shell_command

    filename_queue = self._GetTestFileQueue(test_files)

    # Instantiate TestShellThreads and start them.
    threads = []
    for i in xrange(int(self._options.num_test_shells)):
      # Create separate TestTypes instances for each thread.
      test_types = []
      for t in self._test_types:
        test_types.append(t(self._options.platform,
                            self._options.results_directory))

      test_args, shell_args = self._GetTestShellArgs(i)
      thread = test_shell_thread.TestShellThread(filename_queue,
                                                 self._result_queue,
                                                 test_shell_command,
                                                 test_types,
                                                 test_args,
                                                 shell_args,
                                                 self._options)
      thread.start()
      threads.append(thread)

    return threads

  def _StopLayoutTestHelper(self, proc):
    """Stop the layout test helper and closes it down."""
    if proc:
      logging.debug("Stopping layout test helper")
      proc.stdin.write("x\n")
      proc.stdin.close()
      proc.wait()

  def _RunTests(self, test_shell_binary, file_list, result_summary):
    """Runs the tests in the file_list.

    Return: A tuple (failures, thread_timings, test_timings,
        individual_test_timings)
        failures is a map from test to list of failure types
        thread_timings is a list of dicts with the total runtime of each thread
          with 'name', 'num_tests', 'total_time' properties
        test_timings is a list of timings for each sharded subdirectory of the
          form [time, directory_name, num_tests]
        individual_test_timings is a list of run times for each test in the form
          {filename:filename, test_run_time:test_run_time}
        result_summary: summary object to populate with the results
    """
    threads = self._InstantiateTestShellThreads(test_shell_binary, file_list)

    # Wait for the threads to finish and collect test failures.
    failures = {}
    test_timings = {}
    individual_test_timings = []
    thread_timings = []
    try:
      for thread in threads:
        while thread.isAlive():
          # Let it timeout occasionally so it can notice a KeyboardInterrupt
          # Actually, the timeout doesn't really matter: apparently it
          # suffices to not use an indefinite blocking join for it to
          # be interruptible by KeyboardInterrupt.
          thread.join(0.1)
          self._UpdateSummary(result_summary)
        thread_timings.append({ 'name': thread.getName(),
                                'num_tests': thread.GetNumTests(),
                                'total_time': thread.GetTotalTime()});
        test_timings.update(thread.GetDirectoryTimingStats())
        individual_test_timings.extend(thread.GetIndividualTestStats())
    except KeyboardInterrupt:
      for thread in threads:
        thread.Cancel()
      self._StopLayoutTestHelper(layout_test_helper_proc)
      raise
    for thread in threads:
      # Check whether a TestShellThread died before normal completion.
      exception_info = thread.GetExceptionInfo()
      if exception_info is not None:
        # Re-raise the thread's exception here to make it clear that
        # testing was aborted. Otherwise, the tests that did not run
        # would be assumed to have passed.
        raise exception_info[0], exception_info[1], exception_info[2]

    # Make sure we pick up any remaining tests.
    self._UpdateSummary(result_summary)
    return (thread_timings, test_timings, individual_test_timings)

  def Run(self, result_summary):
    """Run all our tests on all our test files.

    For each test file, we run each test type.  If there are any failures, we
    collect them for reporting.

    Args:
      result_summary: a summary object tracking the test results.

    Return:
      We return nonzero if there are regressions compared to the last run.
    """
    if not self._test_files:
      return 0
    start_time = time.time()
    test_shell_binary = path_utils.TestShellPath(self._options.target)

    # Start up any helper needed
    layout_test_helper_proc = None
    if not options.no_pixel_tests:
      helper_path = path_utils.LayoutTestHelperPath(self._options.target)
      if len(helper_path):
        logging.debug("Starting layout helper %s" % helper_path)
        layout_test_helper_proc = subprocess.Popen([helper_path],
                                                   stdin=subprocess.PIPE,
                                                   stdout=subprocess.PIPE,
                                                   stderr=None)
        is_ready = layout_test_helper_proc.stdout.readline()
        if not is_ready.startswith('ready'):
          logging.error("layout_test_helper failed to be ready")

    # Check that the system dependencies (themes, fonts, ...) are correct.
    if not self._options.nocheck_sys_deps:
      proc = subprocess.Popen([test_shell_binary,
                              "--check-layout-test-sys-deps"])
      if proc.wait() != 0:
        logging.info("Aborting because system dependencies check failed.\n"
                     "To override, invoke with --nocheck-sys-deps")
        sys.exit(1)

    # If we have http tests, the first one will be an http test.
    if ((self._test_files_list and
         self._test_files_list[0].find(self.HTTP_SUBDIR) >= 0)
        or self._options.randomize_order):
      self._http_server.Start()

    # Start Web Socket server.
    if (self._ContainWebSocketTest(self._test_files_list)):
      self._websocket_server.Start()
      # self._websocket_secure_server.Start()

    thread_timings, test_timings, individual_test_timings = (
        self._RunTests(test_shell_binary, self._test_files_list,
                       result_summary))

    # We exclude the crashes from the list of results to retry, because
    # we want to treat even a potentially flaky crash as an error.
    failures = self._GetFailures(result_summary, include_crashes=False)
    retries = 0
    retry_summary = result_summary
    while (retries < self.NUM_RETRY_ON_UNEXPECTED_FAILURE and len(failures)):
      logging.debug("Retrying %d unexpected failure(s)" % len(failures))
      retries += 1
      retry_summary = ResultSummary(self._expectations, failures.keys())
      self._RunTests(test_shell_binary, failures.keys(), retry_summary)
      failures = self._GetFailures(retry_summary, include_crashes=True)

    self._StopLayoutTestHelper(layout_test_helper_proc)
    end_time = time.time()

    write = CreateLoggingWriter(self._options, 'timing')
    self._PrintTimingStatistics(write, end_time - start_time,
                                thread_timings, test_timings,
                                individual_test_timings,
                                result_summary)

    unexpected_results = self._SummarizeUnexpectedResults(result_summary,
        retry_summary)

    if self._options.verbose:
      # We write this block to stdout for compatibility with the buildbot
      # log parser, which only looks at stdout, not stderr :(
      write = lambda s: sys.stdout.write("%s\n" % s)
    else:
      write = CreateLoggingWriter(self._options, 'actual')

    self._PrintResultSummary(write, result_summary)
    write("")

    self._meter.clear()
    sys.stdout.flush()
    sys.stderr.flush()

    # This summary data gets written to stdout regardless of log level
    self._PrintOneLineSummary(result_summary.total, result_summary.expected)

    self._PrintUnexpectedResults(unexpected_results)

    # Write the same data to log files.
    self._WriteJSONFiles(unexpected_results, result_summary,
                         individual_test_timings)

    # Write the summary to disk (results.html) and maybe open the test_shell
    # to this file.
    wrote_results = self._WriteResultsHtmlFile(result_summary)
    if not self._options.noshow_results and wrote_results:
      self._ShowResultsHtmlFile()

    # Ignore flaky failures and unexpected passes so we don't turn the
    # bot red for those.
    return unexpected_results['num_regressions']

  def _UpdateSummary(self, result_summary):
    """Update the summary while running tests."""
    while True:
      try:
        (test, fail_list) = self._result_queue.get_nowait()
        result = test_failures.DetermineResultType(fail_list)
        result_summary.Add(test, fail_list, result)
      except Queue.Empty:
        self._meter.update("Testing: %d ran as expected, %d didn't, %d left" %
             (result_summary.expected, result_summary.unexpected,
              result_summary.remaining))
        return

  def _GetFailures(self, result_summary, include_crashes):
    """Filters a dict of results and returns only the failures.

    Args:
      result_summary: the results of the test run
      include_crashes: whether crashes are included in the output.
        We use False when finding the list of failures to retry
        to see if the results were flaky. Although the crashes may also be
        flaky, we treat them as if they aren't so that they're not ignored.
    Returns:
      a dict of files -> results
    """
    failed_results = {}
    for test, result in result_summary.unexpected_results.iteritems():
      if (result == test_expectations.PASS or
          result == test_expectations.CRASH and not include_crashes):
        continue
      failed_results[test] = result

    return failed_results

  def _SummarizeUnexpectedResults(self, result_summary, retry_summary):
    """Summarize any unexpected results as a dict.

    TODO(dpranke): split this data structure into a separate class?

    Args:
      result_summary: summary object from initial test runs
      retry_summary: summary object from final test run of retried tests
    Returns:
      A dictionary containing a summary of the unexpected results from the
      run, with the following fields:
        'version': a version indicator (1 in this version)
        'fixable': # of fixable tests (NOW - PASS)
        'skipped': # of skipped tests (NOW & SKIPPED)
        'num_regressions': # of non-flaky failures
        'num_flaky': # of flaky failures
        'num_passes': # of unexpected passes
        'tests': a dict of tests -> { 'expected' : '...', 'actual' : '...' }
    """
    results = {}
    results['version'] = 1

    tbe = result_summary.tests_by_expectation
    tbt = result_summary.tests_by_timeline
    results['fixable'] = len(tbt[test_expectations.NOW] -
                             tbe[test_expectations.PASS])
    results['skipped'] = len(tbt[test_expectations.NOW] &
                             tbe[test_expectations.SKIP])

    num_passes = 0
    num_flaky = 0
    num_regressions = 0
    keywords = {}
    for k, v in TestExpectationsFile.EXPECTATIONS.iteritems():
      keywords[v] = k.upper()

    tests = {}
    for filename, result in result_summary.unexpected_results.iteritems():
      # Note that if a test crashed in the original run, we ignore whether or
      # not it crashed when we retried it (if we retried it), and always
      # consider the result not flaky.
      test = path_utils.RelativeTestFilename(filename)
      expected = self._expectations.GetExpectationsString(filename)
      actual = [keywords[result]]

      if result == test_expectations.PASS:
        num_passes += 1
      elif result == test_expectations.CRASH:
        num_regressions += 1
      else:
        if filename not in retry_summary.unexpected_results:
          actual.extend(
              self._expectations.GetExpectationsString(filename).split(" "))
          num_flaky += 1
        else:
          retry_result = retry_summary.unexpected_results[filename]
          if result != retry_result:
            actual.append(keywords[retry_result])
            num_flaky += 1
          else:
            num_regressions += 1

      tests[test] = {}
      tests[test]['expected'] = expected
      tests[test]['actual'] = " ".join(actual)

    results['tests'] = tests
    results['num_passes'] = num_passes
    results['num_flaky'] = num_flaky
    results['num_regressions'] = num_regressions

    return results

  def _WriteJSONFiles(self, unexpected_results, result_summary,
                      individual_test_timings):
    """Writes the results of the test run as JSON files into the results dir.

    There are three different files written into the results dir:
      unexpected_results.json: A short list of any unexpected results. This
        is used by the buildbots to display results.
      expectations.json: This is used by the flakiness dashboard.
      results.json: A full list of the results - used by the flakiness
        dashboard and the aggregate results dashboard.

    Args:
      unexpected_results: dict of unexpected results
      result_summary: full summary object
      individual_test_timings: list of test times (used by the flakiness
        dashboard).
    """
    logging.debug("Writing JSON files in %s." % self._options.results_directory)
    unexpected_file = open(os.path.join(self._options.results_directory,
        "unexpected_results.json"), "w")
    unexpected_file.write(simplejson.dumps(unexpected_results, sort_keys=True,
        indent=2))
    unexpected_file.close()

    # Write a json file of the test_expectations.txt file for the layout tests
    # dashboard.
    expectations_file = open(os.path.join(self._options.results_directory,
        "expectations.json"), "w")
    expectations_json = self._expectations.GetExpectationsJsonForAllPlatforms()
    expectations_file.write(("ADD_EXPECTATIONS(" + expectations_json + ");"))
    expectations_file.close()

    json_results_generator.JSONResultsGenerator(self._options,
        self._expectations, result_summary, individual_test_timings,
        self._options.results_directory, self._test_files_list)

    logging.debug("Finished writing JSON files.")

  def _PrintExpectedResultsOfType(self, write, result_summary, result_type,
      result_type_str):
    """Print the number of the tests in a given result class.

    Args:
      write: A callback to write info to (e.g., a LoggingWriter) or
         sys.stdout.write.
      result_summary - the object containing all the results to report on
      result_type - the particular result type to report in the summary.
      result_type_str - a string description of the result_type.
    """
    tests = self._expectations.GetTestsWithResultType(result_type)
    now = result_summary.tests_by_timeline[test_expectations.NOW]
    wontfix = result_summary.tests_by_timeline[test_expectations.WONTFIX]
    defer = result_summary.tests_by_timeline[test_expectations.DEFER]

    # We use a fancy format string in order to print the data out in a
    # nicely-aligned table.
    fmtstr = ("Expect: %%5d %%-8s (%%%dd now, %%%dd defer, %%%dd wontfix)" %
              (self._NumDigits(now), self._NumDigits(defer),
               self._NumDigits(wontfix)))
    write(fmtstr %
          (len(tests), result_type_str, len(tests & now), len(tests & defer),
           len(tests & wontfix)))

  def _NumDigits(self, num):
    """Returns the number of digits needed to represent the length of a
    sequence."""
    ndigits = 1
    if len(num):
      ndigits = int(math.log10(len(num))) + 1
    return ndigits

  def _PrintTimingStatistics(self, write, total_time, thread_timings,
                             directory_test_timings, individual_test_timings,
                             result_summary):
    """Record timing-specific information for the test run.

    Args:
      write: A callback to write info to (e.g., a LoggingWriter) or
          sys.stdout.write.
      total_time: total elapsed time (in seconds) for the test run
      thread_timings: wall clock time each thread ran for
      directory_test_timings: timing by directory
      individual_test_timings: timing by file
      result_summary: summary object for the test run
    """
    write("Test timing:")
    write("  %6.2f total testing time" % total_time)
    write("")
    write("Thread timing:")
    cuml_time = 0
    for t in thread_timings:
      write("    %10s: %5d tests, %6.2f secs" %
            (t['name'], t['num_tests'], t['total_time']))
      cuml_time += t['total_time']
    write("   %6.2f cumulative, %6.2f optimal" %
          (cuml_time, cuml_time / int(self._options.num_test_shells)))
    write("")

    self._PrintAggregateTestStatistics(write, individual_test_timings)
    self._PrintIndividualTestTimes(write, individual_test_timings,
                                   result_summary)
    self._PrintDirectoryTimings(write, directory_test_timings)

  def _PrintAggregateTestStatistics(self, write, individual_test_timings):
    """Prints aggregate statistics (e.g. median, mean, etc.) for all tests.
    Args:
      write: A callback to write info to (e.g., a LoggingWriter) or
          sys.stdout.write.
      individual_test_timings: List of test_shell_thread.TestStats for all
          tests.
    """
    test_types = individual_test_timings[0].time_for_diffs.keys()
    times_for_test_shell = []
    times_for_diff_processing = []
    times_per_test_type = {}
    for test_type in test_types:
      times_per_test_type[test_type] = []

    for test_stats in individual_test_timings:
      times_for_test_shell.append(test_stats.test_run_time)
      times_for_diff_processing.append(test_stats.total_time_for_all_diffs)
      time_for_diffs = test_stats.time_for_diffs
      for test_type in test_types:
        times_per_test_type[test_type].append(time_for_diffs[test_type])

    self._PrintStatisticsForTestTimings(write,
        "PER TEST TIME IN TESTSHELL (seconds):", times_for_test_shell)
    self._PrintStatisticsForTestTimings(write,
        "PER TEST DIFF PROCESSING TIMES (seconds):", times_for_diff_processing)
    for test_type in test_types:
      self._PrintStatisticsForTestTimings(write,
          "PER TEST TIMES BY TEST TYPE: %s" % test_type,
          times_per_test_type[test_type])

  def _PrintIndividualTestTimes(self, write, individual_test_timings,
                                result_summary):
    """Prints the run times for slow, timeout and crash tests.
    Args:
      write: A callback to write info to (e.g., a LoggingWriter) or
          sys.stdout.write.
      individual_test_timings: List of test_shell_thread.TestStats for all
          tests.
      result_summary: summary object for test run
    """
    # Reverse-sort by the time spent in test_shell.
    individual_test_timings.sort(lambda a, b:
        cmp(b.test_run_time, a.test_run_time))

    num_printed = 0
    slow_tests = []
    timeout_or_crash_tests = []
    unexpected_slow_tests = []
    for test_tuple in individual_test_timings:
      filename = test_tuple.filename
      is_timeout_crash_or_slow = False
      if self._expectations.HasModifier(filename, test_expectations.SLOW):
        is_timeout_crash_or_slow = True
        slow_tests.append(test_tuple)

      if filename in result_summary.failures:
        result = result_summary.failures[filename]
        if (result == test_expectations.TIMEOUT or
            result == test_expectations.CRASH):
          is_timeout_crash_or_slow = True
          timeout_or_crash_tests.append(test_tuple)

      if (not is_timeout_crash_or_slow and
          num_printed < self._options.num_slow_tests_to_log):
        num_printed = num_printed + 1
        unexpected_slow_tests.append(test_tuple)

    write("")
    self._PrintTestListTiming(write, "%s slowest tests that are not marked "
        "as SLOW and did not timeout/crash:" %
        self._options.num_slow_tests_to_log, unexpected_slow_tests)
    write("")
    self._PrintTestListTiming(write, "Tests marked as SLOW:", slow_tests)
    write("")
    self._PrintTestListTiming(write, "Tests that timed out or crashed:",
        timeout_or_crash_tests)
    write("")

  def _PrintTestListTiming(self, write, title, test_list):
    """Print timing info for each test.

    Args:
      write: A callback to write info to (e.g., a LoggingWriter) or
          sys.stdout.write.
      title: section heading
      test_list: tests that fall in this section
    """
    write(title)
    for test_tuple in test_list:
      filename = test_tuple.filename[len(path_utils.LayoutTestsDir()) + 1:]
      filename = filename.replace('\\', '/')
      test_run_time = round(test_tuple.test_run_time, 1)
      write("  %s took %s seconds" % (filename, test_run_time))

  def _PrintDirectoryTimings(self, write, directory_test_timings):
    """Print timing info by directory

    Args:
      write: A callback to write info to (e.g., a LoggingWriter) or
          sys.stdout.write.
      directory_test_timing: time info for each directory
    """
    timings = []
    for directory in directory_test_timings:
      num_tests, time_for_directory = directory_test_timings[directory]
      timings.append((round(time_for_directory, 1), directory, num_tests))
    timings.sort()

    write("Time to process each subdirectory:")
    for timing in timings:
      write("  %s took %s seconds to run %s tests." % (timing[1], timing[0],
            timing[2]))
    write("")

  def _PrintStatisticsForTestTimings(self, write, title, timings):
    """Prints the median, mean and standard deviation of the values in timings.
    Args:
      write: A callback to write info to (e.g., a LoggingWriter) or
          sys.stdout.write.
      title: Title for these timings.
      timings: A list of floats representing times.
    """
    write(title)
    timings.sort()

    num_tests = len(timings)
    percentile90 = timings[int(.9 * num_tests)]
    percentile99 = timings[int(.99 * num_tests)]

    if num_tests % 2 == 1:
      median = timings[((num_tests - 1) / 2) - 1]
    else:
      lower = timings[num_tests / 2 - 1]
      upper = timings[num_tests / 2]
      median = (float(lower + upper)) / 2

    mean = sum(timings) / num_tests

    for time in timings:
      sum_of_deviations = math.pow(time - mean, 2)

    std_deviation = math.sqrt(sum_of_deviations / num_tests)
    write("  Median:          %6.3f" % median)
    write("  Mean:            %6.3f" % mean)
    write("  90th percentile: %6.3f" % percentile90)
    write("  99th percentile: %6.3f" % percentile99)
    write("  Standard dev:    %6.3f" % std_deviation)
    write("")

  def _PrintResultSummary(self, write, result_summary):
    """Print a short summary to the output file about how many tests passed.

    Args:
      write: A callback to write info to (e.g., a LoggingWriter) or
          sys.stdout.write.
      result_summary: information to log
    """
    failed = len(result_summary.failures)
    skipped = len(result_summary.tests_by_expectation[test_expectations.SKIP])
    total = result_summary.total
    passed = total - failed - skipped
    pct_passed = 0.0
    if total > 0:
      pct_passed = float(passed) * 100 / total

    write("");
    write("=> Results: %d/%d tests passed (%.1f%%)" %
                 (passed, total, pct_passed))
    write("");
    self._PrintResultSummaryEntry(write, result_summary, test_expectations.NOW,
       "Tests to be fixed for the current release")

    write("");
    self._PrintResultSummaryEntry(write, result_summary,
       test_expectations.DEFER,
       "Tests we'll fix in the future if they fail (DEFER)")

    write("");
    self._PrintResultSummaryEntry(write, result_summary,
       test_expectations.WONTFIX,
       "Tests that will only be fixed if they crash (WONTFIX)")

  def _PrintResultSummaryEntry(self, write, result_summary, timeline, heading):
    """Print a summary block of results for a particular timeline of test.

    Args:
      write: A callback to write info to (e.g., a LoggingWriter) or
          sys.stdout.write.
      result_summary: summary to print results for
      timeline: the timeline to print results for (NOT, WONTFIX, etc.)
      heading: a textual description of the timeline
    """
    total = len(result_summary.tests_by_timeline[timeline])
    not_passing = (total -
       len(result_summary.tests_by_expectation[test_expectations.PASS] &
           result_summary.tests_by_timeline[timeline]))
    write("=> %s (%d):" % (heading, not_passing))

    for result in TestExpectationsFile.EXPECTATION_ORDER:
      if result == test_expectations.PASS:
        continue
      results = (result_summary.tests_by_expectation[result] &
                 result_summary.tests_by_timeline[timeline])
      desc = TestExpectationsFile.EXPECTATION_DESCRIPTIONS[result]
      plural = ["", "s"]
      if not_passing and len(results):
        pct = len(results) * 100.0 / not_passing
        write("  %5d %-24s (%4.1f%%)" % (len(results),
              desc[len(results) != 1], pct))

  def _PrintOneLineSummary(self, total, expected):
    """Print a one-line summary of the test run to stdout.

    Args:
      total: total number of tests run
      expected: number of expected results
    """
    unexpected = total - expected
    if unexpected == 0:
      print "All %d tests ran as expected." % expected
    elif expected == 1:
      print "1 test ran as expected, %d didn't:" % unexpected
    else:
      print "%d tests ran as expected, %d didn't:" % (expected, unexpected)

  def _PrintUnexpectedResults(self, unexpected_results):
    """Prints any unexpected results in a human-readable form to stdout."""
    passes = {}
    flaky = {}
    regressions = {}

    if len(unexpected_results['tests']):
      print ""

    for test, results in unexpected_results['tests'].iteritems():
      actual = results['actual'].split(" ")
      expected = results['expected'].split(" ")
      if actual == ['PASS']:
        if 'CRASH' in expected:
          _AddToDictOfLists(passes, 'Expected to crash, but passed', test)
        elif 'TIMEOUT' in expected:
          _AddToDictOfLists(passes, 'Expected to timeout, but passed', test)
        else:
          _AddToDictOfLists(passes, 'Expected to fail, but passed', test)
      elif len(actual) > 1:
        # We group flaky tests by the first actual result we got.
        _AddToDictOfLists(flaky, actual[0], test)
      else:
        _AddToDictOfLists(regressions, results['actual'], test)

    if len(passes):
      for key, tests in passes.iteritems():
        print "%s: (%d)" % (key, len(tests))
        tests.sort()
        for test in tests:
          print "  %s" % test
        print

    if len(flaky):
      descriptions = TestExpectationsFile.EXPECTATION_DESCRIPTIONS
      for key, tests in flaky.iteritems():
        result = TestExpectationsFile.EXPECTATIONS[key.lower()]
        print "Unexpected flakiness: %s (%d)" % (
          descriptions[result][1], len(tests))
        tests.sort()

        for test in tests:
          actual = unexpected_results['tests'][test]['actual'].split(" ")
          expected = unexpected_results['tests'][test]['expected'].split(" ")
          result = TestExpectationsFile.EXPECTATIONS[key.lower()]
          new_expectations_list = list(set(actual) | set(expected))
          print "  %s = %s" % (test, " ".join(new_expectations_list))
        print

    if len(regressions):
      descriptions = TestExpectationsFile.EXPECTATION_DESCRIPTIONS
      for key, tests in regressions.iteritems():
        result = TestExpectationsFile.EXPECTATIONS[key.lower()]
        print "Regressions: Unexpected %s : (%d)" % (
          descriptions[result][1], len(tests))
        tests.sort()
        for test in tests:
          print "  %s = %s" % (test, key)
        print

    if len(unexpected_results['tests']) and self._options.verbose:
      print "-" * 78

  def _WriteResultsHtmlFile(self, result_summary):
    """Write results.html which is a summary of tests that failed.

    Args:
      result_summary: a summary of the results :)

    Returns:
      True if any results were written (since expected failures may be omitted)
    """
    # test failures
    if self._options.full_results_html:
      test_files = result_summary.failures.keys()
    else:
      unexpected_failures = self._GetFailures(result_summary,
          include_crashes=True)
      test_files = unexpected_failures.keys()
    if not len(test_files):
      return False

    out_filename = os.path.join(self._options.results_directory,
                                "results.html")
    out_file = open(out_filename, 'w')
    # header
    if self._options.full_results_html:
      h2 = "Test Failures"
    else:
      h2 = "Unexpected Test Failures"
    out_file.write("<html><head><title>Layout Test Results (%(time)s)</title>"
                   "</head><body><h2>%(h2)s (%(time)s)</h2>\n"
                   % {'h2': h2, 'time': time.asctime()})

    test_files.sort()
    for test_file in test_files:
      test_failures = result_summary.failures.get(test_file, [])
      out_file.write("<p><a href='%s'>%s</a><br />\n"
                     % (path_utils.FilenameToUri(test_file),
                        path_utils.RelativeTestFilename(test_file)))
      for failure in test_failures:
        out_file.write("&nbsp;&nbsp;%s<br/>"
                       % failure.ResultHtmlOutput(
                         path_utils.RelativeTestFilename(test_file)))
      out_file.write("</p>\n")

    # footer
    out_file.write("</body></html>\n")
    return True

  def _ShowResultsHtmlFile(self):
    """Launches the test shell open to the results.html page."""
    results_filename = os.path.join(self._options.results_directory,
                                    "results.html")
    subprocess.Popen([path_utils.TestShellPath(self._options.target),
                      path_utils.FilenameToUri(results_filename)])


def _AddToDictOfLists(dict, key, value):
  dict.setdefault(key, []).append(value)

def ReadTestFiles(files):
  tests = []
  for file in files:
    for line in open(file):
      line = test_expectations.StripComments(line)
      if line: tests.append(line)
  return tests

def CreateLoggingWriter(options, log_option):
  """Returns a write() function that will write the string to logging.info()
  if comp was specified in --log or if --verbose is true. Otherwise the
  message is dropped.

  Args:
    options: list of command line options from optparse
    log_option: option to match in options.log in order for the messages to be
        logged (e.g., 'actual' or 'expected')
  """
  if options.verbose or log_option in options.log.split(","):
    return logging.info
  return lambda str: 1

def main(options, args):
  """Run the tests.  Will call sys.exit when complete.

  Args:
    options: a dictionary of command line options
    args: a list of sub directories or files to test
  """

  if options.sources:
    options.verbose = True

  # Set up our logging format.
  meter = metered_stream.MeteredStream(options.verbose, sys.stderr)
  log_fmt = '%(message)s'
  log_datefmt = '%y%m%d %H:%M:%S'
  log_level = logging.INFO
  if options.verbose:
    log_fmt = '%(asctime)s %(filename)s:%(lineno)-4d %(levelname)s %(message)s'
    log_level = logging.DEBUG
  logging.basicConfig(level=log_level, format=log_fmt, datefmt=log_datefmt,
                      stream=meter)

  if not options.target:
    if options.debug:
      options.target = "Debug"
    else:
      options.target = "Release"

  if not options.use_apache:
    options.use_apache = sys.platform in ('darwin', 'linux2')

  if options.results_directory.startswith("/"):
    # Assume it's an absolute path and normalize.
    options.results_directory = path_utils.GetAbsolutePath(
        options.results_directory)
  else:
    # If it's a relative path, make the output directory relative to Debug or
    # Release.
    basedir = path_utils.PathFromBase('webkit')
    options.results_directory = path_utils.GetAbsolutePath(
        os.path.join(basedir, options.target, options.results_directory))

  if options.clobber_old_results:
    # Just clobber the actual test results directories since the other files
    # in the results directory are explicitly used for cross-run tracking.
    test_dirs = ("LayoutTests", "chrome", "pending")
    for directory in test_dirs:
      path = os.path.join(options.results_directory, directory)
      if os.path.exists(path):
        shutil.rmtree(path)

  # Ensure platform is valid and force it to the form 'chromium-<platform>'.
  options.platform = path_utils.PlatformName(options.platform)

  if not options.num_test_shells:
    # TODO(ojan): Investigate perf/flakiness impact of using numcores + 1.
    options.num_test_shells = platform_utils.GetNumCores()

  write = CreateLoggingWriter(options, 'config')
  write("Running %s test_shells in parallel" % options.num_test_shells)

  if not options.time_out_ms:
    if options.target == "Debug":
      options.time_out_ms = str(2 * TestRunner.DEFAULT_TEST_TIMEOUT_MS)
    else:
      options.time_out_ms = str(TestRunner.DEFAULT_TEST_TIMEOUT_MS)

  options.slow_time_out_ms = str(5 * int(options.time_out_ms))
  write("Regular timeout: %s, slow test timeout: %s" %
        (options.time_out_ms, options.slow_time_out_ms))

  # Include all tests if none are specified.
  new_args = []
  for arg in args:
    if arg and arg != '':
      new_args.append(arg)

  paths = new_args
  if not paths:
    paths = []
  if options.test_list:
    paths += ReadTestFiles(options.test_list)

  # Create the output directory if it doesn't already exist.
  path_utils.MaybeMakeDirectory(options.results_directory)
  meter.update("Gathering files ...")

  test_runner = TestRunner(options, meter)
  test_runner.GatherFilePaths(paths)

  if options.lint_test_files:
    # Creating the expecations for each platform/target pair does all the
    # test list parsing and ensures it's correct syntax (e.g. no dupes).
    for platform in TestExpectationsFile.PLATFORMS:
      test_runner.ParseExpectations(platform, is_debug_mode=True)
      test_runner.ParseExpectations(platform, is_debug_mode=False)
    print ("If there are no fail messages, errors or exceptions, then the "
        "lint succeeded.")
    sys.exit(0)

  try:
    test_shell_binary_path = path_utils.TestShellPath(options.target)
  except path_utils.PathNotFound:
    print "\nERROR: test_shell is not found. Be sure that you have built it"
    print "and that you are using the correct build. This script will run the"
    print "Release one by default. Use --debug to use the Debug build.\n"
    sys.exit(1)

  write = CreateLoggingWriter(options, "config")
  write("Using platform '%s'" % options.platform)
  write("Placing test results in %s" % options.results_directory)
  if options.new_baseline:
    write("Placing new baselines in %s" %
          path_utils.ChromiumBaselinePath(options.platform))
  write("Using %s build at %s" % (options.target, test_shell_binary_path))
  if options.no_pixel_tests:
    write("Not running pixel tests")
  write("")

  meter.update("Parsing expectations ...")
  test_runner.ParseExpectations(options.platform, options.target == 'Debug')

  meter.update("Preparing tests ...")
  write = CreateLoggingWriter(options, "expected")
  result_summary = test_runner.PrepareListsAndPrintOutput(write)

  if 'cygwin' == sys.platform:
    logging.warn("#" * 40)
    logging.warn("# UNEXPECTED PYTHON VERSION")
    logging.warn("# This script should be run using the version of python")
    logging.warn("# in third_party/python_24/")
    logging.warn("#" * 40)
    sys.exit(1)

  # Delete the disk cache if any to ensure a clean test run.
  cachedir = os.path.split(test_shell_binary_path)[0]
  cachedir = os.path.join(cachedir, "cache")
  if os.path.exists(cachedir):
    shutil.rmtree(cachedir)

  test_runner.AddTestType(text_diff.TestTextDiff)
  if not options.no_pixel_tests:
    test_runner.AddTestType(image_diff.ImageDiff)
    if options.fuzzy_pixel_tests:
      test_runner.AddTestType(fuzzy_image_diff.FuzzyImageDiff)

  meter.update("Starting ...")
  has_new_failures = test_runner.Run(result_summary)

  logging.debug("Exit status: %d" % has_new_failures)
  sys.exit(has_new_failures)

if '__main__' == __name__:
  option_parser = optparse.OptionParser()
  option_parser.add_option("", "--no-pixel-tests", action="store_true",
                           default=False,
                           help="disable pixel-to-pixel PNG comparisons")
  option_parser.add_option("", "--fuzzy-pixel-tests", action="store_true",
                           default=False,
                           help="Also use fuzzy matching to compare pixel test"
                                " outputs.")
  option_parser.add_option("", "--results-directory",
                           default="layout-test-results",
                           help="Output results directory source dir,"
                                " relative to Debug or Release")
  option_parser.add_option("", "--new-baseline", action="store_true",
                           default=False,
                           help="save all generated results as new baselines "
                                "into the platform directory, overwriting "
                                "whatever's already there.")
  option_parser.add_option("", "--noshow-results", action="store_true",
                           default=False, help="don't launch the test_shell"
                           " with results after the tests are done")
  option_parser.add_option("", "--full-results-html", action="store_true",
                           default=False, help="show all failures in "
                           "results.html, rather than only regressions")
  option_parser.add_option("", "--clobber-old-results", action="store_true",
                           default=False, help="Clobbers test results from "
                           "previous runs.")
  option_parser.add_option("", "--lint-test-files", action="store_true",
                           default=False, help="Makes sure the test files "
                           "parse for all configurations. Does not run any "
                           "tests.")
  option_parser.add_option("", "--force", action="store_true",
                           default=False,
                           help="Run all tests, even those marked SKIP in the "
                                "test list")
  option_parser.add_option("", "--num-test-shells",
                           help="Number of testshells to run in parallel.")
  option_parser.add_option("", "--use-apache", action="store_true",
                           default=False,
                           help="Whether to use apache instead of lighttpd.")
  option_parser.add_option("", "--time-out-ms", default=None,
                           help="Set the timeout for each test")
  option_parser.add_option("", "--run-singly", action="store_true",
                           default=False,
                           help="run a separate test_shell for each test")
  option_parser.add_option("", "--debug", action="store_true", default=False,
                           help="use the debug binary instead of the release "
                                "binary")
  option_parser.add_option("", "--num-slow-tests-to-log", default=50,
                           help="Number of slow tests whose timings to print.")
  option_parser.add_option("", "--platform",
                           help="Override the platform for expected results")
  option_parser.add_option("", "--target", default="",
                           help="Set the build target configuration (overrides"
                                 " --debug)")
  option_parser.add_option("", "--log", action="store", default="",
                           help="log various types of data. The param should "
                           "be a comma-separated list of values from:"
                           "actual,config,expected,timing")
  option_parser.add_option("-v", "--verbose", action="store_true",
                           default=False, help="include debug-level logging")
  option_parser.add_option("", "--sources", action="store_true",
                           help="show expected result file path for each test "
                           "(implies --verbose)")
  option_parser.add_option("", "--startup-dialog", action="store_true",
                           default=False,
                           help="create a dialog on test_shell.exe startup")
  option_parser.add_option("", "--gp-fault-error-box", action="store_true",
                           default=False,
                           help="enable Windows GP fault error box")
  option_parser.add_option("", "--wrapper",
                           help="wrapper command to insert before invocations "
                                "of test_shell; option is split on whitespace "
                                "before running.  (example: "
                                "--wrapper='valgrind --smc-check=all')")
  option_parser.add_option("", "--test-list", action="append",
                           help="read list of tests to run from file",
                           metavar="FILE")
  option_parser.add_option("", "--nocheck-sys-deps", action="store_true",
                           default=False,
                           help="Don't check the system dependencies (themes)")
  option_parser.add_option("", "--randomize-order", action="store_true",
                           default=False,
                           help=("Run tests in random order (useful for "
                                 "tracking down corruption)"))
  option_parser.add_option("", "--run-chunk",
                           default=None,
                           help=("Run a specified chunk (n:l), the nth of len "
                                 "l, of the layout tests"))
  option_parser.add_option("", "--run-part",
                           default=None,
                           help=("Run a specified part (n:m), the nth of m"
                                 " parts, of the layout tests"))
  option_parser.add_option("", "--batch-size",
                           default=None,
                           help=("Run a the tests in batches (n), after every "
                                 "n tests, the test shell is relaunched."))
  option_parser.add_option("", "--builder-name",
                           default="DUMMY_BUILDER_NAME",
                           help=("The name of the builder shown on the "
                                 "waterfall running this script e.g. WebKit."))
  option_parser.add_option("", "--build-name",
                           default="DUMMY_BUILD_NAME",
                           help=("The name of the builder used in its path, "
                                 "e.g. webkit-rel."))
  option_parser.add_option("", "--build-number",
                           default="DUMMY_BUILD_NUMBER",
                           help=("The build number of the builder running"
                                 "this script."))
  option_parser.add_option("", "--experimental-fully-parallel",
                           action="store_true", default=False,
                           help="run all tests in parallel")
  options, args = option_parser.parse_args()
  main(options, args)