tools addition to automate setting up windows toolchain

Attempting to make it easier and more reliable to set up a windows build toolchain. No need to acquire/install IDEs, service packs, patch things, etc. This tool downloads and unpacks sdks and compiler from various freely available sources.

On a clean machine, after getting depot_tools, and running "gclient" (which installs python), and "git clone ..." or "svn co ..." to get the main chromium repo:

c:\chrome>python src\tools\win\toolchain\toolchain.py
...wait 2-10 minutes depending on download speed...
c:\chrome>win_toolchain\env.bat
c:\chrome>cd src
c:\chrome\src>gclient sync
c:\chrome\src>ninja -C out\Debug chrome

This script does not run any "installation" steps, it only extracts tools, and so avoids changing any global machine state. This way, it (intends to) avoid mucking up other compiler installations, and being mucked up by them.

Requires gyp patch at https://codereview.chromium.org/11637025 to avoid needing to add fake registry keys.

BUG=windows compilers is hard, let's go shopping
TEST=on clean vmware win7 x64, and many rollbacks to 'fresh install' snapshot. http://crbug.com/166949 is in progress for a bot that does this.

Review URL: https://codereview.chromium.org/11633012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@175004 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 531 insertions, 0 deletions

diff --git a/tools/win/toolchain/7z/7z.dll b/tools/win/toolchain/7z/7z.dll
new file mode 100644
index 0000000..cea996e
--- /dev/null
+++ b/tools/win/toolchain/7z/7z.dll
diff --git a/tools/win/toolchain/7z/7z.exe b/tools/win/toolchain/7z/7z.exe
new file mode 100644
index 0000000..b55fefe
--- /dev/null
+++ b/tools/win/toolchain/7z/7z.exe
diff --git a/tools/win/toolchain/7z/LICENSE b/tools/win/toolchain/7z/LICENSE
new file mode 100644
index 0000000..21bb84e
--- /dev/null
+++ b/tools/win/toolchain/7z/LICENSE
@@ -0,0 +1,57 @@
+  7-Zip

+  ~~~~~

+  License for use and distribution

+  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

+

+  7-Zip Copyright (C) 1999-2012 Igor Pavlov.

+

+  Licenses for files are:

+

+    1) 7z.dll: GNU LGPL + unRAR restriction

+    2) All other files:  GNU LGPL

+

+  The GNU LGPL + unRAR restriction means that you must follow both 

+  GNU LGPL rules and unRAR restriction rules.

+

+

+  Note: 

+    You can use 7-Zip on any computer, including a computer in a commercial 

+    organization. You don't need to register or pay for 7-Zip.

+

+

+  GNU LGPL information

+  --------------------

+

+    This library is free software; you can redistribute it and/or

+    modify it under the terms of the GNU Lesser General Public

+    License as published by the Free Software Foundation; either

+    version 2.1 of the License, or (at your option) any later version.

+

+    This library is distributed in the hope that it will be useful,

+    but WITHOUT ANY WARRANTY; without even the implied warranty of

+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+    Lesser General Public License for more details.

+

+    You can receive a copy of the GNU Lesser General Public License from 

+    http://www.gnu.org/

+

+

+  unRAR restriction

+  -----------------

+

+    The decompression engine for RAR archives was developed using source 

+    code of unRAR program.

+    All copyrights to original unRAR code are owned by Alexander Roshal.

+

+    The license for original unRAR code has the following restriction:

+

+      The unRAR sources cannot be used to re-create the RAR compression algorithm, 

+      which is proprietary. Distribution of modified unRAR sources in separate form 

+      or as a part of other software is permitted, provided that it is clearly

+      stated in the documentation and source comments that the code may

+      not be used to develop a RAR (WinRAR) compatible archiver.

+

+

+  --

+  Igor Pavlov

+

diff --git a/tools/win/toolchain/toolchain.py b/tools/win/toolchain/toolchain.py
new file mode 100644
index 0000000..56d29ca
--- /dev/null
+++ b/tools/win/toolchain/toolchain.py
@@ -0,0 +1,474 @@
+# Copyright 2012 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.
+
+# Extracts a Windows toolchain suitable for building Chrome from various
+# downloadable pieces.
+
+
+from optparse import OptionParser
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+import urllib2
+
+
+g_temp_dirs = []
+
+
+def RunOrDie(command):
+  rc = subprocess.call(command, shell=True)
+  if rc != 0:
+    raise SystemExit('%s failed.' % command)
+
+
+def TempDir():
+  """Generate a temporary directory (for downloading or extracting to) and keep
+  track of the directory that's created for cleaning up later."""
+  global g_temp_dirs
+  temp = tempfile.mkdtemp()
+  g_temp_dirs.append(temp)
+  return temp
+
+
+def DeleteAllTempDirs():
+  """Remove all temporary directories created by |TempDir()|."""
+  global g_temp_dirs
+  if g_temp_dirs:
+    sys.stdout.write('Cleaning up temporaries...\n')
+  for temp in g_temp_dirs:
+    # shutil.rmtree errors out on read only attributes.
+    RunOrDie('rmdir /s/q "%s"' % temp)
+  g_temp_dirs = []
+
+
+def Download(url, local_path):
+  """Download a large-ish binary file and print some status information while
+  doing so."""
+  sys.stdout.write('Downloading %s...' % url)
+  req = urllib2.urlopen(url)
+  content_length = int(req.headers.get('Content-Length', 0))
+  bytes_read = 0
+  with open(local_path, 'wb') as file:
+    while True:
+      chunk = req.read(1024 * 1024)
+      if not chunk:
+        break
+      bytes_read += len(chunk)
+      file.write(chunk)
+      sys.stdout.write('.')
+  sys.stdout.write('\n')
+  if content_length and content_length != bytes_read:
+    raise SystemExit('Got incorrect number of bytes downloading %s' % url)
+
+
+def DownloadSDK71Iso():
+  sdk7_temp_dir = TempDir()
+  target_path = os.path.join(sdk7_temp_dir, 'GRMSDKX_EN_DVD.iso')
+  Download(
+      ('http://download.microsoft.com/download/'
+       'F/1/0/F10113F5-B750-4969-A255-274341AC6BCE/GRMSDKX_EN_DVD.iso'),
+      target_path)
+  return target_path
+
+
+def DownloadWDKIso():
+  wdk_temp_dir = TempDir()
+  target_path = os.path.join(wdk_temp_dir, 'GRMWDK_EN_7600_1.ISO')
+  Download(
+      ('http://download.microsoft.com/download/'
+       '4/A/2/4A25C7D5-EFBE-4182-B6A9-AE6850409A78/GRMWDK_EN_7600_1.ISO'),
+      target_path)
+  return target_path
+
+
+def DownloadSDKUpdate():
+  sdk_update_temp_dir = TempDir()
+  target_path = os.path.join(sdk_update_temp_dir, 'VC-Compiler-KB2519277.exe')
+  Download(
+      ('http://download.microsoft.com/download/'
+        '7/5/0/75040801-126C-4591-BCE4-4CD1FD1499AA/VC-Compiler-KB2519277.exe'),
+      target_path)
+  return target_path
+
+
+def DownloadDirectXSDK():
+  dxsdk_temp_dir = TempDir()
+  target_path = os.path.join(dxsdk_temp_dir, 'DXSDK_Jun10.exe')
+  Download(
+      ('http://download.microsoft.com/download/'
+       'A/E/7/AE743F1F-632B-4809-87A9-AA1BB3458E31/DXSDK_Jun10.exe'),
+      target_path)
+  return target_path
+
+
+def DownloadSDK8():
+  """Download the Win8 SDK. This one is slightly different than the simple
+  ones above. There is no .ISO distribution for the Windows 8 SDK. Rather, a
+  tool is provided that is a download manager. This is used to download the
+  various .msi files to a target location. Unfortunately, this tool requires
+  elevation for no obvious reason even when only downloading, so this function
+  will trigger a UAC elevation if the script is not run from an elevated
+  prompt."""
+  sdk_temp_dir = TempDir()
+  target_path = os.path.join(sdk_temp_dir, 'sdksetup.exe')
+  standalone_path = os.path.join(sdk_temp_dir, 'Standalone')
+  Download(
+      ('http://download.microsoft.com/download/'
+       'F/1/3/F1300C9C-A120-4341-90DF-8A52509B23AC/standalonesdk/sdksetup.exe'),
+      target_path)
+  sys.stdout.write(
+      'Running sdksetup.exe to download Win8 SDK (may request elevation)...\n')
+  count = 0
+  while count < 5:
+    rc = RunOrDie(target_path + ' /quiet '
+                  '/features OptionId.WindowsDesktopSoftwareDevelopmentKit '
+                  '/layout ' + standalone_path)
+    if rc == 0:
+      return standalone_path
+      break
+    count += 1
+    sys.stdout.write('Windows 8 SDK failed to download, retrying.\n')
+  raise SystemExit("After multiple retries, couldn't download Win8 SDK")
+
+
+class SourceImages(object):
+  def __init__(self, sdk8_path, wdk_iso, sdk7_update, sdk7_path, dxsdk_path):
+    self.sdk8_path = sdk8_path
+    self.wdk_iso = wdk_iso
+    self.sdk7_update = sdk7_update
+    self.sdk7_path = sdk7_path
+    self.dxsdk_path = dxsdk_path
+
+
+def GetSourceImages():
+  """Download all distribution archives for the components we need."""
+  if len(sys.argv) >= 2 and sys.argv[1] == 'local':
+    return SourceImages(
+        sdk8_path=r'C:\Users\Scott\Desktop\wee\Standalone',
+        wdk_iso=r'c:\users\scott\desktop\wee\GRMWDK_EN_7600_1.ISO',
+        sdk7_update=r'c:\users\scott\desktop\wee\VC-Compiler-KB2519277.exe',
+        sdk7_path=r'C:\Users\Scott\Desktop\wee\GRMSDKX_EN_DVD.ISO',
+        dxsdk_path=r'C:\Users\Scott\Desktop\wee\DXSDK_Jun10.exe')
+  else:
+    # Note that we do the Win8 SDK first so that its silly UAC prompt
+    # happens before the user wanders off to get coffee.
+    sdk8_path = DownloadSDK8()
+    wdk_iso = DownloadWDKIso()
+    sdk7_update = DownloadSDKUpdate()
+    sdk7_path = DownloadSDK71Iso()
+    dxsdk_path = DownloadDirectXSDK()
+    return SourceImages(sdk8_path, wdk_iso, sdk7_update, sdk7_path, dxsdk_path)
+
+
+def ExtractIso(iso_path):
+  """Use 7zip to extract the contents of the given .iso (or self-extracting
+  .exe)."""
+  target_path = TempDir()
+  sys.stdout.write('Extracting %s...\n' % iso_path)
+  # TODO(scottmg): Do this (and exe) manually with python code.
+  # Note that at the beginning of main() we set the working directory to 7z's
+  # location.
+  RunOrDie('7z x "%s" -y "-o%s" >nul' % (iso_path, target_path))
+  return target_path
+
+
+ExtractExe = ExtractIso
+
+
+def ExtractMsi(msi_path):
+  """Use msiexec to extract the contents of the given .msi file."""
+  sys.stdout.write('Extracting %s...\n' % msi_path)
+  target_path = TempDir()
+  RunOrDie('msiexec /a "%s" /qn TARGETDIR="%s"' % (msi_path, target_path))
+  return target_path
+
+
+class ExtractedComponents(object):
+  def __init__(self,
+      vc_x86, vc_x64,
+      buildtools_x86, buildtools_x64, libs_x86, libs_x64, headers,
+      update_x86, update_x64,
+      sdk_path, metro_sdk_path,
+      dxsdk):
+    self.vc_x86 = vc_x86
+    self.vc_x64 = vc_x64
+    self.buildtools_x86 = buildtools_x86
+    self.buildtools_x64 = buildtools_x64
+    self.libs_x86 = libs_x86
+    self.libs_x64 = libs_x64
+    self.headers = headers
+    self.update_x86 = update_x86
+    self.update_x64 = update_x64
+    self.sdk_path = sdk_path
+    self.metro_sdk_path = metro_sdk_path
+    self.dxsdk = dxsdk
+
+
+def ExtractComponents(images):
+  """Given the paths to the images, extract the required parts, and return the
+  an object containing paths to all the pieces."""
+  extracted_sdk7 = ExtractIso(images.sdk7_path)
+  extracted_vc_x86 = \
+      ExtractMsi(os.path.join(extracted_sdk7,
+                              r'Setup\vc_stdx86\vc_stdx86.msi'))
+  extracted_vc_x64 = \
+      ExtractMsi(os.path.join(extracted_sdk7,
+                              r'Setup\vc_stdamd64\vc_stdamd64.msi'))
+
+  extracted_wdk = ExtractIso(images.wdk_iso)
+  extracted_buildtools_x86 = \
+      ExtractMsi(os.path.join(extracted_wdk, r'WDK\buildtools_x86fre.msi'))
+  extracted_buildtools_x64 = \
+      ExtractMsi(os.path.join(extracted_wdk, r'WDK\buildtools_x64fre.msi'))
+  extracted_libs_x86 = \
+      ExtractMsi(os.path.join(extracted_wdk, r'WDK\libs_x86fre.msi'))
+  extracted_libs_x64 = \
+      ExtractMsi(os.path.join(extracted_wdk, r'WDK\libs_x64fre.msi'))
+  extracted_headers = \
+      ExtractMsi(os.path.join(extracted_wdk, r'WDK\headers.msi'))
+
+  extracted_update = ExtractExe(images.sdk7_update)
+  extracted_update_x86 = \
+      ExtractMsi(os.path.join(extracted_update, 'vc_stdx86.msi'))
+  extracted_update_x64 = \
+      ExtractMsi(os.path.join(extracted_update, 'vc_stdamd64.msi'))
+
+  sdk_msi_path = os.path.join(
+      images.sdk8_path,
+      r'Installers\Windows Software Development Kit-x86_en-us.msi')
+  extracted_sdk_path = ExtractMsi(sdk_msi_path)
+
+  sdk_metro_msi_path = os.path.join(
+      images.sdk8_path,
+      'Installers',
+      'Windows Software Development Kit for Metro style Apps-x86_en-us.msi')
+  extracted_metro_sdk_path = ExtractMsi(sdk_metro_msi_path)
+
+  extracted_dxsdk = ExtractExe(images.dxsdk_path)
+
+  return ExtractedComponents(
+      vc_x86=extracted_vc_x86,
+      vc_x64=extracted_vc_x64,
+      buildtools_x86=extracted_buildtools_x86,
+      buildtools_x64=extracted_buildtools_x64,
+      libs_x86=extracted_libs_x86,
+      libs_x64=extracted_libs_x64,
+      headers=extracted_headers,
+      update_x86=extracted_update_x86,
+      update_x64=extracted_update_x64,
+      sdk_path=extracted_sdk_path,
+      metro_sdk_path=extracted_metro_sdk_path,
+      dxsdk=extracted_dxsdk)
+
+
+def PullFrom(list_of_path_pairs, source_root, target_dir):
+  """Each pair in |list_of_path_pairs| is (from, to). Join the 'from' with
+  |source_root| and the 'to' with |target_dir| and perform a recursive copy."""
+  for source, destination in list_of_path_pairs:
+    full_source = os.path.join(source_root, source)
+    full_target = os.path.join(target_dir, destination)
+    rc = os.system('robocopy /s "%s" "%s" >nul' % (full_source, full_target))
+    if (rc & 8) != 0 or (rc & 16) != 0:
+      # ref: http://ss64.com/nt/robocopy-exit.html
+      raise SystemExit("Couldn't copy %s to %s" % (full_source, full_target))
+
+
+def CopyToFinalLocation(extracted, target_dir):
+  """Copy all the directories we need to the target location."""
+  sys.stdout.write('Pulling together required pieces...\n')
+
+  # Note that order is important because some of the older ones are
+  # overwritten by updates.
+  from_sdk = [(r'Windows Kits\8.0', r'win8sdk')]
+  PullFrom(from_sdk, extracted.sdk_path, target_dir)
+
+  from_metro_sdk = [(r'Windows Kits\8.0', r'win8sdk')]
+  PullFrom(from_sdk, extracted.metro_sdk_path, target_dir)
+
+  from_buildtools_x86 = [
+      (r'WinDDK\7600.16385.win7_wdk.100208-1538\bin\x86', r'WDK\bin'),
+      (r'WinDDK\7600.16385.win7_wdk.100208-1538\bin\amd64', r'WDK\bin'),
+      ]
+  PullFrom(from_buildtools_x86, extracted.buildtools_x86, target_dir)
+
+  from_buildtools_x64 = [
+      (r'WinDDK\7600.16385.win7_wdk.100208-1538\bin\amd64', r'WDK\bin'),
+      ]
+  PullFrom(from_buildtools_x64, extracted.buildtools_x64, target_dir)
+
+  from_libs_x86 = [
+      (r'WinDDK\7600.16385.win7_wdk.100208-1538\lib', r'WDK\lib'),
+      ]
+  PullFrom(from_libs_x86, extracted.libs_x86, target_dir)
+
+  from_libs_x64 = [
+      (r'WinDDK\7600.16385.win7_wdk.100208-1538\lib', r'WDK\lib'),
+      ]
+  PullFrom(from_libs_x64, extracted.libs_x64, target_dir)
+
+  from_headers = [
+      (r'WinDDK\7600.16385.win7_wdk.100208-1538\inc', r'WDK\inc'),
+      ]
+  PullFrom(from_headers, extracted.headers, target_dir)
+
+  # The compiler update to get the SP1 x86 compiler is a bit of a mess. See
+  # http://goo.gl/n1DeO. The summary is that update for the standalone
+  # compiler binary installs a broken set of headers. So, we need to pull the
+  # new binaries from the update, but keep the older set of headers.
+
+  from_vcupdate_x86 = [
+      (r'Program Files\Microsoft Visual Studio 10.0', '.'),
+      (r'Win\System', r'VC\bin'),
+      ]
+  PullFrom(from_vcupdate_x86, extracted.update_x86, target_dir)
+
+  from_vcupdate_x64 = [
+      (r'Program Files(64)\Microsoft Visual Studio 10.0', '.'),
+      (r'Win\System64', r'VC\bin\amd64'),
+      ]
+  PullFrom(from_vcupdate_x64, extracted.update_x64, target_dir)
+
+  from_sdk7_x86 = [
+      (r'Program Files\Microsoft Visual Studio 10.0', '.'),
+      (r'Win\System', r'VC\bin'),
+      ]
+  PullFrom(from_sdk7_x86, extracted.vc_x86, target_dir)
+
+  from_sdk7_x64 =[
+      (r'Program Files(64)\Microsoft Visual Studio 10.0', '.'),
+      (r'Win\System64', r'VC\bin\amd64'),
+      ]
+  PullFrom(from_sdk7_x64, extracted.vc_x64, target_dir)
+
+  # Now, re-get just the binaries from the update.
+  from_vcupdate_x86 = [
+      (r'Program Files\Microsoft Visual Studio 10.0\VC\bin', r'VC\bin'),
+      ]
+  PullFrom(from_vcupdate_x86, extracted.update_x86, target_dir)
+
+  from_vcupdate_x64 = [
+      (r'Program Files(64)\Microsoft Visual Studio 10.0\VC\bin', r'VC\bin'),
+      ]
+  PullFrom(from_vcupdate_x64, extracted.update_x64, target_dir)
+
+  from_dxsdk = [
+      (r'DXSDK\Include', r'DXSDK\Include'),
+      (r'DXSDK\Lib', r'DXSDK\Lib'),
+      (r'DXSDK\Redist', r'DXSDK\Redist'),
+      ]
+  PullFrom(from_dxsdk, extracted.dxsdk, target_dir)
+
+
+def PatchAsyncInfo(target_dir):
+  """Apply patch from
+  http://www.chromium.org/developers/how-tos/build-instructions-windows for
+  asyncinfo.h."""
+  sys.stdout.write('Patching asyncinfo.h...\n')
+  asyncinfo_h_path = os.path.join(
+      target_dir, r'win8sdk\Include\winrt\asyncinfo.h')
+  with open(asyncinfo_h_path, 'rb') as f:
+    asyncinfo_h = f.read()
+  patched = asyncinfo_h.replace(
+      'enum class AsyncStatus {', 'enum AsyncStatus {')
+  with open(asyncinfo_h_path, 'wb') as f:
+    f.write(patched)
+
+
+def GenerateSetEnvCmd(target_dir):
+  """Generate a batch file that gyp expects to exist to set up the compiler
+  environment. This is normally generated by a full install of the SDK, but we
+  do it here manually since we do not do a full install."""
+  with open(os.path.join(
+        target_dir, r'win8sdk\bin\SetEnv.cmd'), 'w') as file:
+    file.write('@echo off\n')
+    file.write(':: Generated by tools\\win\\toolchain\\toolchain.py.\n')
+    # Common to x86 and x64
+    file.write('set PATH=%s;%%PATH%%\n' % (
+        os.path.join(target_dir, r'Common7\IDE')))
+    file.write('set INCLUDE=%s;%s;%s\n' % (
+        os.path.join(target_dir, r'win8sdk\Include\um'),
+        os.path.join(target_dir, r'win8sdk\Include\shared'),
+        os.path.join(target_dir, r'VC\include')))
+    file.write('if "%1"=="/x64" goto x64\n')
+
+    # x86 only.
+    file.write('set PATH=%s;%s;%s;%%PATH%%\n' % (
+        os.path.join(target_dir, r'win8sdk\bin\x86'),
+        os.path.join(target_dir, r'VC\bin'),
+        os.path.join(target_dir, r'WDK\bin')))
+    file.write('set LIB=%s;%s\n' % (
+        os.path.join(target_dir, r'VC\lib'),
+        os.path.join(target_dir, r'win8sdk\Lib\win8\um\x86')))
+    file.write('goto done\n')
+
+    # x64 only.
+    file.write(':x64\n')
+    file.write('set PATH=%s;%s;%s;%%PATH%%\n' % (
+        os.path.join(target_dir, r'win8sdk\bin\x64'),
+        os.path.join(target_dir, r'VC\bin\amd64'),
+        os.path.join(target_dir, r'WDK\bin\amd64')))
+    file.write('set LIB=%s;%s\n' % (
+        os.path.join(target_dir, r'VC\lib\amd64'),
+        os.path.join(target_dir, r'win8sdk\Lib\win8\um\x64')))
+
+    file.write(':done\n')
+
+
+def GenerateTopLevelEnv(target_dir):
+  """Generate a batch file that sets up various environment variables that let
+  the Chromium build files and gyp find SDKs and tools."""
+  with open(os.path.join(target_dir, r'env.bat'), 'w') as file:
+    file.write('@echo off\n')
+    file.write(':: Generated by tools\\win\\toolchain\\toolchain.py.\n')
+    file.write('set GYP_DEFINES=windows_sdk_path="%s" '
+                'component=shared_library\n' % (
+                    os.path.join(target_dir, 'win8sdk')))
+    file.write('set GYP_MSVS_VERSION=2010e\n')
+    file.write('set GYP_MSVS_OVERRIDE_PATH=%s\n' % target_dir)
+    file.write('set GYP_GENERATORS=ninja\n')
+    file.write('set WDK_DIR=%s\n' % os.path.join(target_dir, r'WDK'))
+    file.write('set DXSDK_DIR=%s\n' % os.path.join(target_dir, r'DXSDK'))
+    file.write('set WindowsSDKDir=%s\n' %
+        os.path.join(target_dir, r'win8sdk'))
+    file.write('echo Environment set for toolchain in %s.\n' % target_dir)
+    file.write('cd /d %s\\..\n' % target_dir)
+
+
+def main():
+  try:
+    parser = OptionParser()
+    parser.add_option('--targetdir', metavar='DIR',
+                      help='put toolchain into DIR',
+                      default=os.path.abspath('win_toolchain'))
+    options, args = parser.parse_args()
+    target_dir = os.path.abspath(options.targetdir)
+    # Set the working directory to 7z subdirectory. 7-zip doesn't find its
+    # codec dll very well, so this is the simplest way to make sure it runs
+    # correctly, as we don't otherwise care about working directory.
+    os.chdir(os.path.join(os.path.dirname(os.path.abspath(__file__)), '7z'))
+    images = GetSourceImages()
+    extracted = ExtractComponents(images)
+    CopyToFinalLocation(extracted, target_dir)
+    PatchAsyncInfo(target_dir)
+    GenerateSetEnvCmd(target_dir)
+    GenerateTopLevelEnv(target_dir)
+  finally:
+    DeleteAllTempDirs()
+
+  sys.stdout.write(
+      '\nIn a (clean) cmd shell, you can now run\n\n'
+      '  %s\\env.bat\n\n'
+      'then\n\n'
+      "  gclient runhooks (or gclient sync if you haven't pulled deps yet)\n"
+      '  ninja -C out\Debug chrome\n\n'
+      'Note that this script intentionally does not modify any global\n'
+      'settings like the registry, or system environment variables, so you\n'
+      'will need to run the above env.bat whenever you start a new\n'
+      'shell.\n\n' % target_dir)
+
+
+if __name__ == '__main__':
+  main()