Build a Syzygy-reordered mini_installer.exe.

chrome/tools/build/win/syzygy_reorder.py

Index: chrome/tools/build/win/syzygy_reorder.py
diff --git a/chrome/tools/build/win/syzygy_reorder.py b/chrome/tools/build/win/syzygy_reorder.py
new file mode 100644
index 0000000000000000000000000000000000000000..8ddef1046d3289d0809bf067f258442d73e405d1
--- /dev/null
+++ b/chrome/tools/build/win/syzygy_reorder.py
@@ -0,0 +1,110 @@
+#!/usr/bin/python
+# Copyright (c) 2011 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.
+
+"""A utility script to help building Syzygy-reordered Chrome binaries."""
+
+import logging
+import optparse
+import os
+import subprocess
+import sys
+
+
+_SRC_DIR = os.path.abspath(
+    os.path.join(os.path.dirname(__file__), '../../../..'))

[robertshield, 2011/11/28 01:16:38]

seems like this should be an input option

[Sigurður Ásgeirsson, 2011/11/28 15:02:10]

It's only used to calculate the path to the default tool to use, though.

+
+# The default relink executable to use to reorder binaries.
+_DEFAULT_RELINKER = os.path.join(_SRC_DIR,
+    'third_party/syzygy/binaries/exe/relink.exe')
+
+# A list of tuples, where each tuple names a binary and its associated PDB file.
+_BINARIES = [('chrome.dll', 'chrome_dll.pdb'),]

[robertshield, 2011/11/28 01:16:38]

feels like this should be specified in a .gyp file as well. Paths set in helper
scripts are fragile and a bit more irksome to track down. 

[Sigurður Ásgeirsson, 2011/11/28 15:02:10]

This is true. However, I was modelling this from the installer archive creation
as I expect we'll optimize more of chrome's exes over time, and it seems like
there's an attempt there to reduce the number of build targets. 
Doesn't make a difference for this iteration, so will change.

+
+_LOGGER = logging.getLogger()
+
+# We use the same seed for all random reorderings to get a deterministic build.
+_RANDOM_SEED = 1347344

[robertshield, 2011/11/28 01:16:38]

this is not a comment, but http://xkcd.com/221/

[Sigurður Ásgeirsson, 2011/11/28 15:02:10]

:)

+
+
+def _Shell(*cmd, **kw):
+  """Shells out to "cmd". Returns a tuple of cmd's stdout, stderr."""
+  _LOGGER.info('Running command "%s".', cmd)
+  prog = subprocess.Popen(cmd, **kw)
+
+  stdout, stderr = prog.communicate()
+  if prog.returncode != 0:
+    raise RuntimeError('Command "%s" returned %d.' % (cmd, prog.returncode))
+
+  return stdout, stderr
+
+
+def _ReorderBinary(relink_exe, binary, symbol, input_dir, output_dir):
+  """Reorders the binary found in input_dir, and writes the resultant
+  reordered binary and symbol files to output_dir.
+
+  If a file named <binary>-order.json exists in the input directory, imposes
+  that order on the output binaries, otherwise orders them randomly.
+  """
+  cmd = [relink_exe,
+         '--verbose',
+         '--input-dll=%s' % os.path.join(input_dir, binary),
+         '--input-pdb=%s' % os.path.join(input_dir, symbol),
+         '--output-dll=%s' % os.path.join(output_dir, binary),
+         '--output-pdb=%s' % os.path.join(output_dir, symbol),]
+
+  # Check whether there's an order file available for the binary.
+  order_file = os.path.join(input_dir, '%s-order.json' % binary)
+  if os.path.exists(order_file):
+    # The ordering file exists, let's use that.
+    _LOGGER.info('Reordering "%s" according to "%s".', binary, order_file)
+    cmd.append('--order-file=%s' % order_file)
+  else:
+    # No ordering file, we randomize the output.

[robertshield, 2011/11/28 01:16:38]

Is the reordered path soon expected to be the default? If so, should this cause
a build warning, or somehow be made very noticeable in the build output when it
takes the random reordering path?

[Sigurður Ásgeirsson, 2011/11/28 15:02:10]

Good question - I figure once we turn this on for the official builds, we'll
want the build to fail if the ordering file is missing. There'll be a followup
CL once I figure out how best to do that.

+    _LOGGER.info('Randomly reordering "%s"', binary)
+    cmd.append('--seed=%d' % _RANDOM_SEED)
+
+  return _Shell(*cmd)
+
+
+def main(options):
+  logging.basicConfig(level=logging.INFO)
+
+  # Make sure the destination directory exists.
+  if not os.path.isdir(options.destination_dir):
+    _LOGGER.info('Creating destination directory "%s".',
+                 options.destination_dir)
+    os.makedirs(options.destination_dir)
+
+  for (binary, symbol) in _BINARIES:
+    # Reorder the binaries into the destination directory, one by one.
+    _ReorderBinary(options.relinker,
+                   binary,
+                   symbol,
+                   options.output_dir,
+                   options.destination_dir)
+
+
+def _ParseOptions():
+  option_parser = optparse.OptionParser()
+  option_parser.add_option('-o', '--output_dir',
+      help='Output directory where the original binaries are built.')
+  option_parser.add_option('--relinker', default=_DEFAULT_RELINKER,
+      help='Relinker exectuable to use, defaults to "%s"' % _DEFAULT_RELINKER)
+  option_parser.add_option('-d', '--destination_dir',
+      help='Destination directory for reordered files, defaults to '
+           'the subdirectory "reordered" in the output_dir.')
+  options, args = option_parser.parse_args()
+
+  if not options.output_dir:
+    option_parser.error('You must provide an output dir.')
+
+  if not options.destination_dir:
+    options.destination_dir = os.path.join(options.output_dir, 'reordered')
+
+  return options
+
+
+if '__main__' == __name__:
+  sys.exit(main(_ParseOptions()))