Merge V8 5.2.361.47  DO NOT MERGE

https://chromium.googlesource.com/v8/v8/+/5.2.361.47

FPIIM-449

Change-Id: Ibec421b85a9b88cb3a432ada642e469fe7e78346
(cherry picked from commit bcf72ee8e3b26f1d0726869c7ddb3921c68b09a8)
diff --git a/gypfiles/OWNERS b/gypfiles/OWNERS
new file mode 100644
index 0000000..0e56af3
--- /dev/null
+++ b/gypfiles/OWNERS
@@ -0,0 +1 @@
+machenbach@chromium.org
diff --git a/gypfiles/README.txt b/gypfiles/README.txt
new file mode 100644
index 0000000..5f242ad
--- /dev/null
+++ b/gypfiles/README.txt
@@ -0,0 +1,9 @@
+For build instructions, please refer to:
+
+https://code.google.com/p/v8/wiki/BuildingWithGYP
+
+TL;DR version on *nix:
+$ make dependencies        # Only needed once.
+$ make ia32.release -j8
+$ make ia32.release.check  # Optionally: run tests.
+
diff --git a/gypfiles/all.gyp b/gypfiles/all.gyp
new file mode 100644
index 0000000..ff1bea4
--- /dev/null
+++ b/gypfiles/all.gyp
@@ -0,0 +1,54 @@
+# Copyright 2011 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+  'targets': [
+    {
+      'target_name': 'All',
+      'type': 'none',
+      'dependencies': [
+        '../src/d8.gyp:d8',
+      ],
+      'conditions': [
+        ['component!="shared_library"', {
+          'dependencies': [
+            '../tools/parser-shell.gyp:parser-shell',
+          ],
+        }],
+        # These items don't compile for Android on Mac.
+        ['host_os!="mac" or OS!="android"', {
+          'dependencies': [
+            '../samples/samples.gyp:*',
+            '../test/cctest/cctest.gyp:*',
+            '../test/fuzzer/fuzzer.gyp:*',
+            '../test/unittests/unittests.gyp:*',
+            ],
+        }],
+        ['test_isolation_mode != "noop"', {
+          'dependencies': [
+            '../test/bot_default.gyp:*',
+            '../test/benchmarks/benchmarks.gyp:*',
+            '../test/default.gyp:*',
+            '../test/ignition.gyp:*',
+            '../test/intl/intl.gyp:*',
+            '../test/message/message.gyp:*',
+            '../test/mjsunit/mjsunit.gyp:*',
+            '../test/mozilla/mozilla.gyp:*',
+            '../test/optimize_for_size.gyp:*',
+            '../test/perf.gyp:*',
+            '../test/preparser/preparser.gyp:*',
+            '../test/simdjs/simdjs.gyp:*',
+            '../test/test262/test262.gyp:*',
+            '../test/webkit/webkit.gyp:*',
+            '../tools/check-static-initializers.gyp:*',
+            '../tools/gcmole/run_gcmole.gyp:*',
+            '../tools/jsfunfuzz/jsfunfuzz.gyp:*',
+            '../tools/run-deopt-fuzzer.gyp:*',
+            '../tools/run-valgrind.gyp:*',
+          ],
+        }],
+      ]
+    }
+  ]
+}
diff --git a/gypfiles/config/win/msvs_dependencies.isolate b/gypfiles/config/win/msvs_dependencies.isolate
new file mode 100644
index 0000000..ff92227
--- /dev/null
+++ b/gypfiles/config/win/msvs_dependencies.isolate
@@ -0,0 +1,77 @@
+# Copyright 2015 the V8 project authors. All rights reserved.
+# Copyright 2015 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.
+{
+  'conditions': [
+    # Copy the VS runtime DLLs into the isolate so that they
+    # don't have to be preinstalled on the target machine.
+    #
+    # VS2013 runtimes
+    ['OS=="win" and msvs_version==2013 and component=="shared_library" and CONFIGURATION_NAME=="Debug"', {
+      'variables': {
+        'files': [
+          '<(PRODUCT_DIR)/x64/msvcp120d.dll',
+          '<(PRODUCT_DIR)/x64/msvcr120d.dll',
+        ],
+      },
+    }],
+    ['OS=="win" and msvs_version==2013 and component=="shared_library" and CONFIGURATION_NAME=="Release"', {
+      'variables': {
+        'files': [
+          '<(PRODUCT_DIR)/x64/msvcp120.dll',
+          '<(PRODUCT_DIR)/x64/msvcr120.dll',
+        ],
+      },
+    }],
+    ['OS=="win" and msvs_version==2013 and component=="shared_library" and (CONFIGURATION_NAME=="Debug" or CONFIGURATION_NAME=="Debug_x64")', {
+      'variables': {
+        'files': [
+          '<(PRODUCT_DIR)/msvcp120d.dll',
+          '<(PRODUCT_DIR)/msvcr120d.dll',
+        ],
+      },
+    }],
+    ['OS=="win" and msvs_version==2013 and component=="shared_library" and (CONFIGURATION_NAME=="Release" or CONFIGURATION_NAME=="Release_x64")', {
+      'variables': {
+        'files': [
+          '<(PRODUCT_DIR)/msvcp120.dll',
+          '<(PRODUCT_DIR)/msvcr120.dll',
+        ],
+      },
+    }],
+    # VS2015 runtimes
+    ['OS=="win" and msvs_version==2015 and component=="shared_library" and CONFIGURATION_NAME=="Debug"', {
+      'variables': {
+        'files': [
+          '<(PRODUCT_DIR)/x64/msvcp140d.dll',
+          '<(PRODUCT_DIR)/x64/vccorlib140d.dll',
+        ],
+      },
+    }],
+    ['OS=="win" and msvs_version==2015 and component=="shared_library" and CONFIGURATION_NAME=="Release"', {
+      'variables': {
+        'files': [
+          '<(PRODUCT_DIR)/x64/msvcp140.dll',
+          '<(PRODUCT_DIR)/x64/vccorlib140.dll',
+        ],
+      },
+    }],
+    ['OS=="win" and msvs_version==2015 and component=="shared_library" and (CONFIGURATION_NAME=="Debug" or CONFIGURATION_NAME=="Debug_x64")', {
+      'variables': {
+        'files': [
+          '<(PRODUCT_DIR)/msvcp140d.dll',
+          '<(PRODUCT_DIR)/vccorlib140d.dll',
+        ],
+      },
+    }],
+    ['OS=="win" and msvs_version==2015 and component=="shared_library" and (CONFIGURATION_NAME=="Release" or CONFIGURATION_NAME=="Release_x64")', {
+      'variables': {
+        'files': [
+          '<(PRODUCT_DIR)/msvcp140.dll',
+          '<(PRODUCT_DIR)/vccorlib140.dll',
+        ],
+      },
+    }],
+  ],
+}
\ No newline at end of file
diff --git a/gypfiles/coverage_wrapper.py b/gypfiles/coverage_wrapper.py
new file mode 100755
index 0000000..5b365d8
--- /dev/null
+++ b/gypfiles/coverage_wrapper.py
@@ -0,0 +1,36 @@
+#!/usr/bin/env python
+# Copyright 2016 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# CC/CXX wrapper script that excludes certain file patterns from coverage
+# instrumentation.
+
+import re
+import subprocess
+import sys
+
+exclusions = [
+  'buildtools',
+  'src/third_party',
+  'third_party',
+  'test',
+  'testing',
+]
+
+def remove_if_exists(string_list, item):
+  if item in string_list:
+    string_list.remove(item)
+
+args = sys.argv[1:]
+text = ' '.join(sys.argv[2:])
+for exclusion in exclusions:
+  if re.search(r'\-o obj/%s[^ ]*\.o' % exclusion, text):
+    remove_if_exists(args, '-fprofile-arcs')
+    remove_if_exists(args, '-ftest-coverage')
+    remove_if_exists(args, '-fsanitize-coverage=func')
+    remove_if_exists(args, '-fsanitize-coverage=bb')
+    remove_if_exists(args, '-fsanitize-coverage=edge')
+    break
+
+sys.exit(subprocess.check_call(args))
diff --git a/gypfiles/detect_v8_host_arch.py b/gypfiles/detect_v8_host_arch.py
new file mode 100644
index 0000000..89e8286
--- /dev/null
+++ b/gypfiles/detect_v8_host_arch.py
@@ -0,0 +1,77 @@
+#!/usr/bin/env python
+# Copyright 2014 the V8 project authors. All rights reserved.
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+#       copyright notice, this list of conditions and the following
+#       disclaimer in the documentation and/or other materials provided
+#       with the distribution.
+#     * Neither the name of Google Inc. nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Outputs host CPU architecture in format recognized by gyp."""
+
+import platform
+import re
+import sys
+
+
+def main():
+  print DoMain([])
+  return 0
+
+def DoMain(_):
+  """Hook to be called from gyp without starting a separate python
+  interpreter."""
+  host_arch = platform.machine()
+  host_system = platform.system();
+
+  # Convert machine type to format recognized by gyp.
+  if re.match(r'i.86', host_arch) or host_arch == 'i86pc':
+    host_arch = 'ia32'
+  elif host_arch in ['x86_64', 'amd64']:
+    host_arch = 'x64'
+  elif host_arch.startswith('arm'):
+    host_arch = 'arm'
+  elif host_arch == 'aarch64':
+    host_arch = 'arm64'
+  elif host_arch == 'mips64':
+    host_arch = 'mips64el'
+  elif host_arch.startswith('mips'):
+    host_arch = 'mipsel'
+
+  # Under AIX the value returned by platform.machine is not
+  # the best indicator of the host architecture
+  # AIX 6.1 which is the lowest level supported only provides
+  # a 64 bit kernel
+  if host_system == 'AIX':
+    host_arch = 'ppc64'
+
+  # platform.machine is based on running kernel. It's possible to use 64-bit
+  # kernel with 32-bit userland, e.g. to give linker slightly more memory.
+  # Distinguish between different userland bitness by querying
+  # the python binary.
+  if host_arch == 'x64' and platform.architecture()[0] == '32bit':
+    host_arch = 'ia32'
+
+  return host_arch
+
+if __name__ == '__main__':
+  sys.exit(main())
diff --git a/gypfiles/download_gold_plugin.py b/gypfiles/download_gold_plugin.py
new file mode 100755
index 0000000..b8131fd
--- /dev/null
+++ b/gypfiles/download_gold_plugin.py
@@ -0,0 +1,81 @@
+#!/usr/bin/env python
+# Copyright 2015 the V8 project authors. All rights reserved.
+# Copyright 2015 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.
+
+"""Script to download LLVM gold plugin from google storage."""
+
+import json
+import os
+import re
+import platform
+import shutil
+import subprocess
+import sys
+import zipfile
+
+# Bail out on windows and cygwin.
+if "win" in platform.system().lower():
+  # Python 2.7.6 hangs at the second path.insert command on windows. Works
+  # with python 2.7.8.
+  print "Gold plugin download not supported on windows."
+  sys.exit(0)
+
+SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
+CHROME_SRC = os.path.abspath(os.path.join(SCRIPT_DIR, os.pardir))
+sys.path.insert(0, os.path.join(CHROME_SRC, 'tools'))
+
+import find_depot_tools
+
+DEPOT_PATH = find_depot_tools.add_depot_tools_to_path()
+GSUTIL_PATH = os.path.join(DEPOT_PATH, 'gsutil.py')
+
+LLVM_BUILD_PATH = os.path.join(CHROME_SRC, 'third_party', 'llvm-build',
+                               'Release+Asserts')
+CLANG_UPDATE_PY = os.path.join(CHROME_SRC, 'tools', 'clang', 'scripts',
+                               'update.py')
+CLANG_REVISION = os.popen(CLANG_UPDATE_PY + ' --print-revision').read().rstrip()
+
+CLANG_BUCKET = 'gs://chromium-browser-clang/Linux_x64'
+
+GOLD_PLUGIN_PATH = os.path.join(LLVM_BUILD_PATH, 'lib', 'LLVMgold.so')
+
+sys.path.insert(0, os.path.join(CHROME_SRC, 'tools', 'clang', 'scripts'))
+
+import update
+
+def main():
+  if not re.search(r'cfi_vptr=1', os.environ.get('GYP_DEFINES', '')):
+    # Bailout if this is not a cfi build.
+    print 'Skipping gold plugin download for non-cfi build.'
+    return 0
+  if (os.path.exists(GOLD_PLUGIN_PATH) and
+      update.ReadStampFile().strip() == update.PACKAGE_VERSION):
+    # Bailout if clang is up-to-date. This requires the script to be run before
+    # the clang update step! I.e. afterwards clang would always be up-to-date.
+    print 'Skipping gold plugin download. File present and clang up to date.'
+    return 0
+
+  # Make sure this works on empty checkouts (i.e. clang not downloaded yet).
+  if not os.path.exists(LLVM_BUILD_PATH):
+    os.makedirs(LLVM_BUILD_PATH)
+
+  targz_name = 'llvmgold-%s.tgz' % CLANG_REVISION
+  remote_path = '%s/%s' % (CLANG_BUCKET, targz_name)
+
+  os.chdir(LLVM_BUILD_PATH)
+
+  # TODO(pcc): Fix gsutil.py cp url file < /dev/null 2>&0
+  # (currently aborts with exit code 1,
+  # https://github.com/GoogleCloudPlatform/gsutil/issues/289) or change the
+  # stdin->stderr redirect in update.py to do something else (crbug.com/494442).
+  subprocess.check_call(['python', GSUTIL_PATH,
+                         'cp', remote_path, targz_name],
+                        stderr=open('/dev/null', 'w'))
+  subprocess.check_call(['tar', 'xzf', targz_name])
+  os.remove(targz_name)
+  return 0
+
+if __name__ == '__main__':
+  sys.exit(main())
diff --git a/gypfiles/features.gypi b/gypfiles/features.gypi
new file mode 100644
index 0000000..5a21a63
--- /dev/null
+++ b/gypfiles/features.gypi
@@ -0,0 +1,136 @@
+# Copyright 2013 the V8 project authors. All rights reserved.
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+#       copyright notice, this list of conditions and the following
+#       disclaimer in the documentation and/or other materials provided
+#       with the distribution.
+#     * Neither the name of Google Inc. nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# Compile time controlled V8 features.
+
+{
+  'variables': {
+    'v8_enable_disassembler%': 0,
+
+    'v8_enable_gdbjit%': 0,
+
+    'v8_object_print%': 0,
+
+    'v8_enable_verify_heap%': 0,
+
+    'v8_trace_maps%': 0,
+
+    # Enable the snapshot feature, for fast context creation.
+    # http://v8project.blogspot.com/2015/09/custom-startup-snapshots.html
+    'v8_use_snapshot%': 'true',
+
+    'v8_enable_verify_predictable%': 0,
+
+    # With post mortem support enabled, metadata is embedded into libv8 that
+    # describes various parameters of the VM for use by debuggers. See
+    # tools/gen-postmortem-metadata.py for details.
+    'v8_postmortem_support%': 'false',
+
+    # Interpreted regexp engine exists as platform-independent alternative
+    # based where the regular expression is compiled to a bytecode.
+    'v8_interpreted_regexp%': 0,
+
+    # Enable ECMAScript Internationalization API. Enabling this feature will
+    # add a dependency on the ICU library.
+    'v8_enable_i18n_support%': 1,
+
+    # Enable compiler warnings when using V8_DEPRECATED apis.
+    'v8_deprecation_warnings%': 0,
+
+    # Enable compiler warnings when using V8_DEPRECATE_SOON apis.
+    'v8_imminent_deprecation_warnings%': 0,
+
+    # Set to 1 to enable DCHECKs in release builds.
+    'dcheck_always_on%': 0,
+
+    # Enable/disable JavaScript API accessors.
+    'v8_js_accessors%': 0,
+  },
+  'target_defaults': {
+    'conditions': [
+      ['v8_enable_disassembler==1', {
+        'defines': ['ENABLE_DISASSEMBLER',],
+      }],
+      ['v8_enable_gdbjit==1', {
+        'defines': ['ENABLE_GDB_JIT_INTERFACE',],
+      }],
+      ['v8_object_print==1', {
+        'defines': ['OBJECT_PRINT',],
+      }],
+      ['v8_enable_verify_heap==1', {
+        'defines': ['VERIFY_HEAP',],
+      }],
+      ['v8_trace_maps==1', {
+        'defines': ['TRACE_MAPS',],
+      }],
+      ['v8_enable_verify_predictable==1', {
+        'defines': ['VERIFY_PREDICTABLE',],
+      }],
+      ['v8_interpreted_regexp==1', {
+        'defines': ['V8_INTERPRETED_REGEXP',],
+      }],
+      ['v8_deprecation_warnings==1', {
+        'defines': ['V8_DEPRECATION_WARNINGS',],
+      }],
+      ['v8_imminent_deprecation_warnings==1', {
+        'defines': ['V8_IMMINENT_DEPRECATION_WARNINGS',],
+      }],
+      ['v8_enable_i18n_support==1', {
+        'defines': ['V8_I18N_SUPPORT',],
+      }],
+      ['v8_use_snapshot=="true" and v8_use_external_startup_data==1', {
+        'defines': ['V8_USE_EXTERNAL_STARTUP_DATA',],
+      }],
+      ['dcheck_always_on!=0', {
+        'defines': ['DEBUG',],
+      }],
+    ],  # conditions
+    'configurations': {
+      'DebugBaseCommon': {
+        'abstract': 1,
+        'variables': {
+          'v8_enable_handle_zapping%': 1,
+        },
+        'conditions': [
+          ['v8_enable_handle_zapping==1', {
+            'defines': ['ENABLE_HANDLE_ZAPPING',],
+          }],
+        ],
+      },  # Debug
+      'Release': {
+        'variables': {
+          'v8_enable_handle_zapping%': 0,
+        },
+        'conditions': [
+          ['v8_enable_handle_zapping==1', {
+            'defines': ['ENABLE_HANDLE_ZAPPING',],
+          }],
+        ],  # conditions
+      },  # Release
+    },  # configurations
+  },  # target_defaults
+}
diff --git a/gypfiles/get_landmines.py b/gypfiles/get_landmines.py
new file mode 100755
index 0000000..2bbf7a6
--- /dev/null
+++ b/gypfiles/get_landmines.py
@@ -0,0 +1,34 @@
+#!/usr/bin/env python
+# Copyright 2014 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+This file emits the list of reasons why a particular build needs to be clobbered
+(or a list of 'landmines').
+"""
+
+import sys
+
+
+def main():
+  """
+  ALL LANDMINES ARE EMITTED FROM HERE.
+  """
+  print 'Need to clobber after ICU52 roll.'
+  print 'Landmines test.'
+  print 'Activating MSVS 2013.'
+  print 'Revert activation of MSVS 2013.'
+  print 'Activating MSVS 2013 again.'
+  print 'Clobber after ICU roll.'
+  print 'Moar clobbering...'
+  print 'Remove build/android.gypi'
+  print 'Cleanup after windows ninja switch attempt.'
+  print 'Switching to pinned msvs toolchain.'
+  print 'Clobbering to hopefully resolve problem with mksnapshot'
+  print 'Clobber after ICU roll.'
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())
diff --git a/gypfiles/gyp_environment.py b/gypfiles/gyp_environment.py
new file mode 100644
index 0000000..7a4e622
--- /dev/null
+++ b/gypfiles/gyp_environment.py
@@ -0,0 +1,54 @@
+# Copyright 2015 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Sets up various automatic gyp environment variables. These are used by
+gyp_v8 and landmines.py which run at different stages of runhooks. To
+make sure settings are consistent between them, all setup should happen here.
+"""
+
+import os
+import sys
+import vs_toolchain
+
+SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
+V8_ROOT = os.path.abspath(os.path.join(SCRIPT_DIR, os.pardir))
+
+
+def apply_gyp_environment(file_path=None):
+  """
+  Reads in a *.gyp_env file and applies the valid keys to os.environ.
+  """
+  if not file_path or not os.path.exists(file_path):
+    return
+  file_contents = open(file_path).read()
+  try:
+    file_data = eval(file_contents, {'__builtins__': None}, None)
+  except SyntaxError, e:
+    e.filename = os.path.abspath(file_path)
+    raise
+  supported_vars = ( 'V8_GYP_FILE',
+                     'V8_GYP_SYNTAX_CHECK',
+                     'GYP_DEFINES',
+                     'GYP_GENERATOR_FLAGS',
+                     'GYP_GENERATOR_OUTPUT', )
+  for var in supported_vars:
+    val = file_data.get(var)
+    if val:
+      if var in os.environ:
+        print 'INFO: Environment value for "%s" overrides value in %s.' % (
+            var, os.path.abspath(file_path)
+        )
+      else:
+        os.environ[var] = val
+
+
+def set_environment():
+  """Sets defaults for GYP_* variables."""
+
+  if 'SKIP_V8_GYP_ENV' not in os.environ:
+    # Update the environment based on v8.gyp_env
+    gyp_env_path = os.path.join(os.path.dirname(V8_ROOT), 'v8.gyp_env')
+    apply_gyp_environment(gyp_env_path)
+    vs_toolchain.SetEnvironmentAndGetRuntimeDllDirs()
diff --git a/gypfiles/gyp_v8 b/gypfiles/gyp_v8
new file mode 100755
index 0000000..e97507a
--- /dev/null
+++ b/gypfiles/gyp_v8
@@ -0,0 +1,181 @@
+#!/usr/bin/env python
+#
+# Copyright 2012 the V8 project authors. All rights reserved.
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+#       copyright notice, this list of conditions and the following
+#       disclaimer in the documentation and/or other materials provided
+#       with the distribution.
+#     * Neither the name of Google Inc. nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# This script is wrapper for V8 that adds some support for how GYP
+# is invoked by V8 beyond what can be done in the gclient hooks.
+
+import argparse
+import glob
+import gyp_environment
+import os
+import platform
+import shlex
+import subprocess
+import sys
+import vs_toolchain
+
+script_dir = os.path.dirname(os.path.realpath(__file__))
+v8_root = os.path.abspath(os.path.join(script_dir, os.pardir))
+
+sys.path.insert(0, os.path.join(v8_root, 'tools', 'gyp', 'pylib'))
+import gyp
+
+# Add paths so that pymod_do_main(...) can import files.
+sys.path.insert(
+    1, os.path.abspath(os.path.join(v8_root, 'tools', 'generate_shim_headers')))
+
+
+def GetOutputDirectory():
+  """Returns the output directory that GYP will use."""
+
+  # Handle command line generator flags.
+  parser = argparse.ArgumentParser()
+  parser.add_argument('-G', dest='genflags', default=[], action='append')
+  genflags = parser.parse_known_args()[0].genflags
+
+  # Handle generator flags from the environment.
+  genflags += shlex.split(os.environ.get('GYP_GENERATOR_FLAGS', ''))
+
+  needle = 'output_dir='
+  for item in genflags:
+    if item.startswith(needle):
+      return item[len(needle):]
+
+  return 'out'
+
+
+def additional_include_files(args=[]):
+  """
+  Returns a list of additional (.gypi) files to include, without
+  duplicating ones that are already specified on the command line.
+  """
+  # Determine the include files specified on the command line.
+  # This doesn't cover all the different option formats you can use,
+  # but it's mainly intended to avoid duplicating flags on the automatic
+  # makefile regeneration which only uses this format.
+  specified_includes = set()
+  for arg in args:
+    if arg.startswith('-I') and len(arg) > 2:
+      specified_includes.add(os.path.realpath(arg[2:]))
+
+  result = []
+  def AddInclude(path):
+    if os.path.realpath(path) not in specified_includes:
+      result.append(path)
+
+  # Always include standalone.gypi
+  AddInclude(os.path.join(v8_root, 'gypfiles', 'standalone.gypi'))
+
+  # Optionally add supplemental .gypi files if present.
+  supplements = glob.glob(os.path.join(v8_root, '*', 'supplement.gypi'))
+  for supplement in supplements:
+    AddInclude(supplement)
+
+  return result
+
+
+def run_gyp(args):
+  rc = gyp.main(args)
+
+  vs2013_runtime_dll_dirs = vs_toolchain.SetEnvironmentAndGetRuntimeDllDirs()
+  if vs2013_runtime_dll_dirs:
+    x64_runtime, x86_runtime = vs2013_runtime_dll_dirs
+    vs_toolchain.CopyVsRuntimeDlls(
+      os.path.join(v8_root, GetOutputDirectory()),
+      (x86_runtime, x64_runtime))
+
+  if rc != 0:
+    print 'Error running GYP'
+    sys.exit(rc)
+
+
+if __name__ == '__main__':
+  args = sys.argv[1:]
+
+  gyp_environment.set_environment()
+
+  # This could give false positives since it doesn't actually do real option
+  # parsing.  Oh well.
+  gyp_file_specified = False
+  for arg in args:
+    if arg.endswith('.gyp'):
+      gyp_file_specified = True
+      break
+
+  # If we didn't get a file, check an env var, and then fall back to
+  # assuming 'all.gyp' from the same directory as the script.
+  if not gyp_file_specified:
+    gyp_file = os.environ.get('V8_GYP_FILE')
+    if gyp_file:
+      # Note that V8_GYP_FILE values can't have backslashes as
+      # path separators even on Windows due to the use of shlex.split().
+      args.extend(shlex.split(gyp_file))
+    else:
+      args.append(os.path.join(script_dir, 'all.gyp'))
+
+  args.extend(['-I' + i for i in additional_include_files(args)])
+
+  # There shouldn't be a circular dependency relationship between .gyp files
+  args.append('--no-circular-check')
+
+  # Set the GYP DEPTH variable to the root of the V8 project.
+  args.append('--depth=' + os.path.relpath(v8_root))
+
+  # If V8_GYP_SYNTAX_CHECK is set to 1, it will invoke gyp with --check
+  # to enfore syntax checking.
+  syntax_check = os.environ.get('V8_GYP_SYNTAX_CHECK')
+  if syntax_check and int(syntax_check):
+    args.append('--check')
+
+  print 'Updating projects from gyp files...'
+  sys.stdout.flush()
+
+  # Generate for the architectures supported on the given platform.
+  gyp_args = list(args)
+  gyp_args.extend(['-D', 'gyp_output_dir=' + GetOutputDirectory()])
+  gyp_generators = os.environ.get('GYP_GENERATORS', '')
+  if platform.system() == 'Linux' and gyp_generators != 'ninja':
+    # Work around for crbug.com/331475.
+    for f in glob.glob(os.path.join(v8_root, 'out', 'Makefile.*')):
+      os.unlink(f)
+    # --generator-output defines where the Makefile goes.
+    gyp_args.append('--generator-output=out')
+    # -Goutput_dir defines where the build output goes, relative to the
+    # Makefile. Set it to . so that the build output doesn't end up in out/out.
+    gyp_args.append('-Goutput_dir=.')
+
+  gyp_defines = os.environ.get('GYP_DEFINES', '')
+
+  # Automatically turn on crosscompile support for platforms that need it.
+  if all(('ninja' in gyp_generators,
+          'OS=android' in gyp_defines,
+          'GYP_CROSSCOMPILE' not in os.environ)):
+    os.environ['GYP_CROSSCOMPILE'] = '1'
+
+  run_gyp(gyp_args)
diff --git a/gypfiles/gyp_v8.py b/gypfiles/gyp_v8.py
new file mode 100644
index 0000000..462ee67
--- /dev/null
+++ b/gypfiles/gyp_v8.py
@@ -0,0 +1,41 @@
+# Copyright 2013 the V8 project authors. All rights reserved.
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+#       copyright notice, this list of conditions and the following
+#       disclaimer in the documentation and/or other materials provided
+#       with the distribution.
+#     * Neither the name of Google Inc. nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# This file is (possibly, depending on python version) imported by
+# gyp_v8 when GYP_PARALLEL=1 and it creates sub-processes through the
+# multiprocessing library.
+
+# Importing in Python 2.6 (fixed in 2.7) on Windows doesn't search for imports
+# that don't end in .py (and aren't directories with an __init__.py). This
+# wrapper makes "import gyp_v8" work with those old versions and makes it
+# possible to execute gyp_v8.py directly on Windows where the extension is
+# useful.
+
+import os
+
+path = os.path.abspath(os.path.split(__file__)[0])
+execfile(os.path.join(path, 'gyp_v8'))
diff --git a/gypfiles/has_valgrind.py b/gypfiles/has_valgrind.py
new file mode 100755
index 0000000..83a848d
--- /dev/null
+++ b/gypfiles/has_valgrind.py
@@ -0,0 +1,21 @@
+#!/usr/bin/env python
+# Copyright 2016 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+
+BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+VALGRIND_DIR = os.path.join(BASE_DIR, 'third_party', 'valgrind')
+LINUX32_DIR = os.path.join(VALGRIND_DIR, 'linux_x86')
+LINUX64_DIR = os.path.join(VALGRIND_DIR, 'linux_x64')
+
+
+def DoMain(_):
+  """Hook to be called from gyp without starting a separate python
+  interpreter."""
+  return int(os.path.exists(LINUX32_DIR) and os.path.exists(LINUX64_DIR))
+
+
+if __name__ == '__main__':
+  print DoMain([])
diff --git a/gypfiles/isolate.gypi b/gypfiles/isolate.gypi
new file mode 100644
index 0000000..a9614b5
--- /dev/null
+++ b/gypfiles/isolate.gypi
@@ -0,0 +1,100 @@
+# Copyright 2015 the V8 project authors. All rights reserved.
+# Copyright (c) 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.
+
+# This file is meant to be included into a target to provide a rule
+# to "build" .isolate files into a .isolated file.
+#
+# To use this, create a gyp target with the following form:
+# 'conditions': [
+#   ['test_isolation_mode != "noop"', {
+#     'targets': [
+#       {
+#         'target_name': 'foo_test_run',
+#         'type': 'none',
+#         'dependencies': [
+#           'foo_test',
+#         ],
+#         'includes': [
+#           '../gypfiles/isolate.gypi',
+#         ],
+#         'sources': [
+#           'foo_test.isolate',
+#         ],
+#       },
+#     ],
+#   }],
+# ],
+#
+# Note: foo_test.isolate is included and a source file. It is an inherent
+# property of the .isolate format. This permits to define GYP variables but is
+# a stricter format than GYP so isolate.py can read it.
+#
+# The generated .isolated file will be:
+#   <(PRODUCT_DIR)/foo_test.isolated
+#
+# See http://dev.chromium.org/developers/testing/isolated-testing/for-swes
+# for more information.
+
+{
+  'rules': [
+    {
+      'rule_name': 'isolate',
+      'extension': 'isolate',
+      'inputs': [
+        # Files that are known to be involved in this step.
+        '<(DEPTH)/tools/isolate_driver.py',
+        '<(DEPTH)/tools/swarming_client/isolate.py',
+        '<(DEPTH)/tools/swarming_client/run_isolated.py',
+      ],
+      'outputs': [
+        '<(PRODUCT_DIR)/<(RULE_INPUT_ROOT).isolated',
+      ],
+      'action': [
+        'python',
+        '<(DEPTH)/tools/isolate_driver.py',
+        '<(test_isolation_mode)',
+        '--isolated', '<(PRODUCT_DIR)/<(RULE_INPUT_ROOT).isolated',
+        '--isolate', '<(RULE_INPUT_PATH)',
+
+        # Variables should use the -V FOO=<(FOO) form so frequent values,
+        # like '0' or '1', aren't stripped out by GYP. Run 'isolate.py help'
+        # for more details.
+
+        # Path variables are used to replace file paths when loading a .isolate
+        # file
+        '--path-variable', 'DEPTH', '<(DEPTH)',
+        '--path-variable', 'PRODUCT_DIR', '<(PRODUCT_DIR)',
+
+        '--config-variable', 'CONFIGURATION_NAME=<(CONFIGURATION_NAME)',
+        '--config-variable', 'OS=<(OS)',
+        '--config-variable', 'asan=<(asan)',
+        '--config-variable', 'cfi_vptr=<(cfi_vptr)',
+        '--config-variable', 'gcmole=<(gcmole)',
+        '--config-variable', 'has_valgrind=<(has_valgrind)',
+        '--config-variable', 'icu_use_data_file_flag=0',
+        '--config-variable', 'msan=<(msan)',
+        '--config-variable', 'tsan=<(tsan)',
+        '--config-variable', 'coverage=<(coverage)',
+        '--config-variable', 'sanitizer_coverage=<(sanitizer_coverage)',
+        '--config-variable', 'component=<(component)',
+        '--config-variable', 'target_arch=<(target_arch)',
+        '--config-variable', 'use_custom_libcxx=<(use_custom_libcxx)',
+        '--config-variable', 'v8_use_external_startup_data=<(v8_use_external_startup_data)',
+        '--config-variable', 'v8_use_snapshot=<(v8_use_snapshot)',
+      ],
+      'conditions': [
+        ['OS=="win"', {
+          'action': [
+            '--config-variable', 'msvs_version=2013',
+          ],
+        }, {
+          'action': [
+            '--config-variable', 'msvs_version=0',
+          ],
+        }],
+      ],
+    },
+  ],
+}
diff --git a/gypfiles/landmine_utils.py b/gypfiles/landmine_utils.py
new file mode 100644
index 0000000..cb34991
--- /dev/null
+++ b/gypfiles/landmine_utils.py
@@ -0,0 +1,123 @@
+# Copyright 2014 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+
+import functools
+import logging
+import os
+import shlex
+import sys
+
+
+def memoize(default=None):
+  """This decorator caches the return value of a parameterless pure function"""
+  def memoizer(func):
+    val = []
+    @functools.wraps(func)
+    def inner():
+      if not val:
+        ret = func()
+        val.append(ret if ret is not None else default)
+        if logging.getLogger().isEnabledFor(logging.INFO):
+          print '%s -> %r' % (func.__name__, val[0])
+      return val[0]
+    return inner
+  return memoizer
+
+
+@memoize()
+def IsWindows():
+  return sys.platform in ['win32', 'cygwin']
+
+
+@memoize()
+def IsLinux():
+  return sys.platform.startswith(('linux', 'freebsd'))
+
+
+@memoize()
+def IsMac():
+  return sys.platform == 'darwin'
+
+
+@memoize()
+def gyp_defines():
+  """Parses and returns GYP_DEFINES env var as a dictionary."""
+  return dict(arg.split('=', 1)
+      for arg in shlex.split(os.environ.get('GYP_DEFINES', '')))
+
+
+@memoize()
+def gyp_generator_flags():
+  """Parses and returns GYP_GENERATOR_FLAGS env var as a dictionary."""
+  return dict(arg.split('=', 1)
+      for arg in shlex.split(os.environ.get('GYP_GENERATOR_FLAGS', '')))
+
+
+@memoize()
+def gyp_msvs_version():
+  return os.environ.get('GYP_MSVS_VERSION', '')
+
+
+@memoize()
+def distributor():
+  """
+  Returns a string which is the distributed build engine in use (if any).
+  Possible values: 'goma', 'ib', ''
+  """
+  if 'goma' in gyp_defines():
+    return 'goma'
+  elif IsWindows():
+    if 'CHROME_HEADLESS' in os.environ:
+      return 'ib' # use (win and !goma and headless) as approximation of ib
+
+
+@memoize()
+def platform():
+  """
+  Returns a string representing the platform this build is targetted for.
+  Possible values: 'win', 'mac', 'linux', 'ios', 'android'
+  """
+  if 'OS' in gyp_defines():
+    if 'android' in gyp_defines()['OS']:
+      return 'android'
+    else:
+      return gyp_defines()['OS']
+  elif IsWindows():
+    return 'win'
+  elif IsLinux():
+    return 'linux'
+  else:
+    return 'mac'
+
+
+@memoize()
+def builder():
+  """
+  Returns a string representing the build engine (not compiler) to use.
+  Possible values: 'make', 'ninja', 'xcode', 'msvs', 'scons'
+  """
+  if 'GYP_GENERATORS' in os.environ:
+    # for simplicity, only support the first explicit generator
+    generator = os.environ['GYP_GENERATORS'].split(',')[0]
+    if generator.endswith('-android'):
+      return generator.split('-')[0]
+    elif generator.endswith('-ninja'):
+      return 'ninja'
+    else:
+      return generator
+  else:
+    if platform() == 'android':
+      # Good enough for now? Do any android bots use make?
+      return 'make'
+    elif platform() == 'ios':
+      return 'xcode'
+    elif IsWindows():
+      return 'msvs'
+    elif IsLinux():
+      return 'make'
+    elif IsMac():
+      return 'xcode'
+    else:
+      assert False, 'Don\'t know what builder we\'re using!'
diff --git a/gypfiles/landmines.py b/gypfiles/landmines.py
new file mode 100755
index 0000000..2a81c66
--- /dev/null
+++ b/gypfiles/landmines.py
@@ -0,0 +1,245 @@
+#!/usr/bin/env python
+# Copyright 2014 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+This script runs every build as the first hook (See DEPS). If it detects that
+the build should be clobbered, it will delete the contents of the build
+directory.
+
+A landmine is tripped when a builder checks out a different revision, and the
+diff between the new landmines and the old ones is non-null. At this point, the
+build is clobbered.
+"""
+
+import difflib
+import errno
+import gyp_environment
+import logging
+import optparse
+import os
+import re
+import shutil
+import sys
+import subprocess
+import time
+
+import landmine_utils
+
+
+SRC_DIR = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
+
+
+def get_build_dir(build_tool, is_iphone=False):
+  """
+  Returns output directory absolute path dependent on build and targets.
+  Examples:
+    r'c:\b\build\slave\win\build\src\out'
+    '/mnt/data/b/build/slave/linux/build/src/out'
+    '/b/build/slave/ios_rel_device/build/src/xcodebuild'
+
+  Keep this function in sync with tools/build/scripts/slave/compile.py
+  """
+  ret = None
+  if build_tool == 'xcode':
+    ret = os.path.join(SRC_DIR, 'xcodebuild')
+  elif build_tool in ['make', 'ninja', 'ninja-ios']:  # TODO: Remove ninja-ios.
+    if 'CHROMIUM_OUT_DIR' in os.environ:
+      output_dir = os.environ.get('CHROMIUM_OUT_DIR').strip()
+      if not output_dir:
+        raise Error('CHROMIUM_OUT_DIR environment variable is set but blank!')
+    else:
+      output_dir = landmine_utils.gyp_generator_flags().get('output_dir', 'out')
+    ret = os.path.join(SRC_DIR, output_dir)
+  elif build_tool in ['msvs', 'vs', 'ib']:
+    ret = os.path.join(SRC_DIR, 'build')
+  else:
+    raise NotImplementedError('Unexpected GYP_GENERATORS (%s)' % build_tool)
+  return os.path.abspath(ret)
+
+
+def extract_gn_build_commands(build_ninja_file):
+  """Extracts from a build.ninja the commands to run GN.
+
+  The commands to run GN are the gn rule and build.ninja build step at the
+  top of the build.ninja file. We want to keep these when deleting GN builds
+  since we want to preserve the command-line flags to GN.
+
+  On error, returns the empty string."""
+  result = ""
+  with open(build_ninja_file, 'r') as f:
+    # Read until the second blank line. The first thing GN writes to the file
+    # is the "rule gn" and the second is the section for "build build.ninja",
+    # separated by blank lines.
+    num_blank_lines = 0
+    while num_blank_lines < 2:
+      line = f.readline()
+      if len(line) == 0:
+        return ''  # Unexpected EOF.
+      result += line
+      if line[0] == '\n':
+        num_blank_lines = num_blank_lines + 1
+  return result
+
+def delete_build_dir(build_dir):
+  # GN writes a build.ninja.d file. Note that not all GN builds have args.gn.
+  build_ninja_d_file = os.path.join(build_dir, 'build.ninja.d')
+  if not os.path.exists(build_ninja_d_file):
+    shutil.rmtree(build_dir)
+    return
+
+  # GN builds aren't automatically regenerated when you sync. To avoid
+  # messing with the GN workflow, erase everything but the args file, and
+  # write a dummy build.ninja file that will automatically rerun GN the next
+  # time Ninja is run.
+  build_ninja_file = os.path.join(build_dir, 'build.ninja')
+  build_commands = extract_gn_build_commands(build_ninja_file)
+
+  try:
+    gn_args_file = os.path.join(build_dir, 'args.gn')
+    with open(gn_args_file, 'r') as f:
+      args_contents = f.read()
+  except IOError:
+    args_contents = ''
+
+  shutil.rmtree(build_dir)
+
+  # Put back the args file (if any).
+  os.mkdir(build_dir)
+  if args_contents != '':
+    with open(gn_args_file, 'w') as f:
+      f.write(args_contents)
+
+  # Write the build.ninja file sufficiently to regenerate itself.
+  with open(os.path.join(build_dir, 'build.ninja'), 'w') as f:
+    if build_commands != '':
+      f.write(build_commands)
+    else:
+      # Couldn't parse the build.ninja file, write a default thing.
+      f.write('''rule gn
+command = gn -q gen //out/%s/
+description = Regenerating ninja files
+
+build build.ninja: gn
+generator = 1
+depfile = build.ninja.d
+''' % (os.path.split(build_dir)[1]))
+
+  # Write a .d file for the build which references a nonexistant file. This
+  # will make Ninja always mark the build as dirty.
+  with open(build_ninja_d_file, 'w') as f:
+    f.write('build.ninja: nonexistant_file.gn\n')
+
+
+def needs_clobber(landmines_path, new_landmines):
+  if os.path.exists(landmines_path):
+    with open(landmines_path, 'r') as f:
+      old_landmines = f.readlines()
+    if old_landmines != new_landmines:
+      old_date = time.ctime(os.stat(landmines_path).st_ctime)
+      diff = difflib.unified_diff(old_landmines, new_landmines,
+          fromfile='old_landmines', tofile='new_landmines',
+          fromfiledate=old_date, tofiledate=time.ctime(), n=0)
+      sys.stdout.write('Clobbering due to:\n')
+      sys.stdout.writelines(diff)
+      return True
+  else:
+    sys.stdout.write('Clobbering due to missing landmines file.\n')
+    return True
+  return False
+
+
+def clobber_if_necessary(new_landmines):
+  """Does the work of setting, planting, and triggering landmines."""
+  out_dir = get_build_dir(landmine_utils.builder())
+  landmines_path = os.path.normpath(os.path.join(out_dir, '..', '.landmines'))
+  try:
+    os.makedirs(out_dir)
+  except OSError as e:
+    if e.errno == errno.EEXIST:
+      pass
+
+  if needs_clobber(landmines_path, new_landmines):
+    # Clobber contents of build directory but not directory itself: some
+    # checkouts have the build directory mounted.
+    for f in os.listdir(out_dir):
+      path = os.path.join(out_dir, f)
+      if os.path.basename(out_dir) == 'build':
+        # Only delete build directories and files for MSVS builds as the folder
+        # shares some checked out files and directories.
+        if (os.path.isdir(path) and
+            re.search(r'(?:[Rr]elease)|(?:[Dd]ebug)', f)):
+          delete_build_dir(path)
+        elif (os.path.isfile(path) and
+              (path.endswith('.sln') or
+               path.endswith('.vcxproj') or
+               path.endswith('.vcxproj.user'))):
+          os.unlink(path)
+      else:
+        if os.path.isfile(path):
+          os.unlink(path)
+        elif os.path.isdir(path):
+          delete_build_dir(path)
+    if os.path.basename(out_dir) == 'xcodebuild':
+      # Xcodebuild puts an additional project file structure into build,
+      # while the output folder is xcodebuild.
+      project_dir = os.path.join(SRC_DIR, 'build', 'all.xcodeproj')
+      if os.path.exists(project_dir) and os.path.isdir(project_dir):
+        delete_build_dir(project_dir)
+
+  # Save current set of landmines for next time.
+  with open(landmines_path, 'w') as f:
+    f.writelines(new_landmines)
+
+
+def process_options():
+  """Returns a list of landmine emitting scripts."""
+  parser = optparse.OptionParser()
+  parser.add_option(
+      '-s', '--landmine-scripts', action='append',
+      default=[os.path.join(SRC_DIR, 'gypfiles', 'get_landmines.py')],
+      help='Path to the script which emits landmines to stdout. The target '
+           'is passed to this script via option -t. Note that an extra '
+           'script can be specified via an env var EXTRA_LANDMINES_SCRIPT.')
+  parser.add_option('-v', '--verbose', action='store_true',
+      default=('LANDMINES_VERBOSE' in os.environ),
+      help=('Emit some extra debugging information (default off). This option '
+          'is also enabled by the presence of a LANDMINES_VERBOSE environment '
+          'variable.'))
+
+  options, args = parser.parse_args()
+
+  if args:
+    parser.error('Unknown arguments %s' % args)
+
+  logging.basicConfig(
+      level=logging.DEBUG if options.verbose else logging.ERROR)
+
+  extra_script = os.environ.get('EXTRA_LANDMINES_SCRIPT')
+  if extra_script:
+    return options.landmine_scripts + [extra_script]
+  else:
+    return options.landmine_scripts
+
+
+def main():
+  landmine_scripts = process_options()
+
+  if landmine_utils.builder() in ('dump_dependency_json', 'eclipse'):
+    return 0
+
+  gyp_environment.set_environment()
+
+  landmines = []
+  for s in landmine_scripts:
+    proc = subprocess.Popen([sys.executable, s], stdout=subprocess.PIPE)
+    output, _ = proc.communicate()
+    landmines.extend([('%s\n' % l.strip()) for l in output.splitlines()])
+  clobber_if_necessary(landmines)
+
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())
diff --git a/gypfiles/mac/asan.gyp b/gypfiles/mac/asan.gyp
new file mode 100644
index 0000000..3fc7f58
--- /dev/null
+++ b/gypfiles/mac/asan.gyp
@@ -0,0 +1,31 @@
+# Copyright 2015 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+   'targets': [
+     {
+       'target_name': 'asan_dynamic_runtime',
+       'toolsets': ['target', 'host'],
+       'type': 'none',
+       'variables': {
+         # Every target is going to depend on asan_dynamic_runtime, so allow
+         # this one to depend on itself.
+         'prune_self_dependency': 1,
+         # Path is relative to this GYP file.
+         'asan_rtl_mask_path':
+             '../../third_party/llvm-build/Release+Asserts/lib/clang/*/lib/darwin',
+         'asan_osx_dynamic':
+             '<(asan_rtl_mask_path)/libclang_rt.asan_osx_dynamic.dylib',
+       },
+       'copies': [
+         {
+           'destination': '<(PRODUCT_DIR)',
+           'files': [
+             '<!(/bin/ls <(asan_osx_dynamic))',
+           ],
+         },
+       ],
+     },
+   ],
+}
diff --git a/gypfiles/set_clang_warning_flags.gypi b/gypfiles/set_clang_warning_flags.gypi
new file mode 100644
index 0000000..63d5f14
--- /dev/null
+++ b/gypfiles/set_clang_warning_flags.gypi
@@ -0,0 +1,59 @@
+# Copyright 2016 the V8 project authors. All rights reserved.
+# Copyright (c) 2014 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.
+
+# This file is meant to be included to set clang-specific compiler flags.
+# To use this the following variable can be defined:
+#   clang_warning_flags:       list: Compiler flags to pass to clang.
+#   clang_warning_flags_unset: list: Compiler flags to not pass to clang.
+#
+# Only use this in third-party code. In chromium_code, fix your code to not
+# warn instead!
+#
+# Note that the gypi file is included in target_defaults, so it does not need
+# to be explicitly included.
+#
+# Warning flags set by this will be used on all platforms. If you want to set
+# warning flags on only some platforms, you have to do so manually.
+#
+# To use this, create a gyp target with the following form:
+# {
+#   'target_name': 'my_target',
+#   'variables': {
+#     'clang_warning_flags': ['-Wno-awesome-warning'],
+#     'clang_warning_flags_unset': ['-Wpreviously-set-flag'],
+#   }
+# }
+
+{
+  'variables': {
+    'clang_warning_flags_unset%': [],  # Provide a default value.
+  },
+  'conditions': [
+    ['clang==1', {
+      # This uses >@ instead of @< to also see clang_warning_flags set in
+      # targets directly, not just the clang_warning_flags in target_defaults.
+      'cflags': [ '>@(clang_warning_flags)' ],
+      'cflags!': [ '>@(clang_warning_flags_unset)' ],
+      'xcode_settings': {
+        'WARNING_CFLAGS': ['>@(clang_warning_flags)'],
+        'WARNING_CFLAGS!': ['>@(clang_warning_flags_unset)'],
+      },
+      'msvs_settings': {
+        'VCCLCompilerTool': {
+          'AdditionalOptions': [ '>@(clang_warning_flags)' ],
+          'AdditionalOptions!': [ '>@(clang_warning_flags_unset)' ],
+        },
+      },
+    }],
+    ['clang==0 and host_clang==1', {
+      'target_conditions': [
+        ['_toolset=="host"', {
+          'cflags': [ '>@(clang_warning_flags)' ],
+          'cflags!': [ '>@(clang_warning_flags_unset)' ],
+        }],
+      ],
+    }],
+  ],
+}
diff --git a/gypfiles/shim_headers.gypi b/gypfiles/shim_headers.gypi
new file mode 100644
index 0000000..940211c
--- /dev/null
+++ b/gypfiles/shim_headers.gypi
@@ -0,0 +1,73 @@
+# Copyright 2013 the V8 project authors. All rights reserved.
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+#       copyright notice, this list of conditions and the following
+#       disclaimer in the documentation and/or other materials provided
+#       with the distribution.
+#     * Neither the name of Google Inc. nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# This file is meant to be included into a target to handle shim headers
+# in a consistent manner. To use this the following variables need to be
+# defined:
+#   headers_root_path: string: path to directory containing headers
+#   header_filenames: list: list of header file names
+
+{
+  'variables': {
+    'shim_headers_path': '<(SHARED_INTERMEDIATE_DIR)/shim_headers/<(_target_name)/<(_toolset)',
+    'shim_generator_additional_args%': [],
+  },
+  'include_dirs++': [
+    '<(shim_headers_path)',
+  ],
+  'all_dependent_settings': {
+    'include_dirs+++': [
+      '<(shim_headers_path)',
+    ],
+  },
+  'actions': [
+    {
+      'variables': {
+        'generator_path': '<(DEPTH)/tools/generate_shim_headers/generate_shim_headers.py',
+        'generator_args': [
+          '--headers-root', '<(headers_root_path)',
+          '--output-directory', '<(shim_headers_path)',
+          '<@(shim_generator_additional_args)',
+          '<@(header_filenames)',
+        ],
+      },
+      'action_name': 'generate_<(_target_name)_shim_headers',
+      'inputs': [
+        '<(generator_path)',
+      ],
+      'outputs': [
+        '<!@pymod_do_main(generate_shim_headers <@(generator_args) --outputs)',
+      ],
+      'action': ['python',
+                 '<(generator_path)',
+                 '<@(generator_args)',
+                 '--generate',
+      ],
+      'message': 'Generating <(_target_name) shim headers.',
+    },
+  ],
+}
diff --git a/gypfiles/standalone.gypi b/gypfiles/standalone.gypi
new file mode 100644
index 0000000..630c45e
--- /dev/null
+++ b/gypfiles/standalone.gypi
@@ -0,0 +1,1460 @@
+# Copyright 2012 the V8 project authors. All rights reserved.
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+#       copyright notice, this list of conditions and the following
+#       disclaimer in the documentation and/or other materials provided
+#       with the distribution.
+#     * Neither the name of Google Inc. nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# Definitions to be used when building stand-alone V8 binaries.
+
+{
+  # We need to include toolchain.gypi here for third-party sources that don't
+  # directly include it themselves.
+  'includes': ['toolchain.gypi'],
+  'variables': {
+    'component%': 'static_library',
+    'clang_xcode%': 0,
+    # Track where uninitialized memory originates from. From fastest to
+    # slowest: 0 - no tracking, 1 - track only the initial allocation site, 2
+    # - track the chain of stores leading from allocation site to use site.
+    'msan_track_origins%': 2,
+    'visibility%': 'hidden',
+    'v8_enable_backtrace%': 0,
+    'v8_enable_i18n_support%': 1,
+    'v8_deprecation_warnings': 1,
+    'v8_imminent_deprecation_warnings': 1,
+    'msvs_multi_core_compile%': '1',
+    'mac_deployment_target%': '10.7',
+    'release_extra_cflags%': '',
+    'variables': {
+      'variables': {
+        'variables': {
+          'conditions': [
+            ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or \
+               OS=="netbsd" or OS=="mac" or OS=="qnx" or OS=="aix"', {
+              # This handles the Unix platforms we generally deal with.
+              # Anything else gets passed through, which probably won't work
+              # very well; such hosts should pass an explicit target_arch
+              # to gyp.
+              'host_arch%': '<!pymod_do_main(detect_v8_host_arch)',
+            }, {
+              # OS!="linux" and OS!="freebsd" and OS!="openbsd" and
+              # OS!="netbsd" and OS!="mac" and OS!="aix"
+              'host_arch%': 'ia32',
+            }],
+          ],
+        },
+        'host_arch%': '<(host_arch)',
+        'target_arch%': '<(host_arch)',
+        'base_dir%': '<!(cd <(DEPTH) && python -c "import os; print os.getcwd()")',
+
+        # Instrument for code coverage and use coverage wrapper to exclude some
+        # files. Uses gcov if clang=0 is set explicitly. Otherwise,
+        # sanitizer_coverage must be set too.
+        'coverage%': 0,
+      },
+      'base_dir%': '<(base_dir)',
+      'host_arch%': '<(host_arch)',
+      'target_arch%': '<(target_arch)',
+      'v8_target_arch%': '<(target_arch)',
+      'coverage%': '<(coverage)',
+      'asan%': 0,
+      'lsan%': 0,
+      'msan%': 0,
+      'tsan%': 0,
+      # Enable coverage gathering instrumentation in sanitizer tools. This flag
+      # also controls coverage granularity (1 for function-level, 2 for
+      # block-level, 3 for edge-level).
+      'sanitizer_coverage%': 0,
+      # Use libc++ (buildtools/third_party/libc++ and
+      # buildtools/third_party/libc++abi) instead of stdlibc++ as standard
+      # library. This is intended to be used for instrumented builds.
+      'use_custom_libcxx%': 0,
+
+      'clang_dir%': '<(base_dir)/third_party/llvm-build/Release+Asserts',
+
+      'use_lto%': 0,
+
+      # Control Flow Integrity for virtual calls and casts.
+      # See http://clang.llvm.org/docs/ControlFlowIntegrity.html
+      'cfi_vptr%': 0,
+      'cfi_diag%': 0,
+
+      'cfi_blacklist%': '<(base_dir)/tools/cfi/blacklist.txt',
+
+      # Set to 1 to enable fast builds.
+      # TODO(machenbach): Only configured for windows.
+      'fastbuild%': 0,
+
+      # goma settings.
+      # 1 to use goma.
+      # If no gomadir is set, it uses the default gomadir.
+      'use_goma%': 0,
+      'gomadir%': '',
+
+      # Check if valgrind directories are present.
+      'has_valgrind%': '<!pymod_do_main(has_valgrind)',
+
+      'test_isolation_mode%': 'noop',
+
+      'conditions': [
+        # Set default gomadir.
+        ['OS=="win"', {
+          'gomadir': 'c:\\goma\\goma-win',
+        }, {
+          'gomadir': '<!(/bin/echo -n ${HOME}/goma)',
+        }],
+        ['host_arch!="ppc" and host_arch!="ppc64" and host_arch!="ppc64le" and host_arch!="s390" and host_arch!="s390x"', {
+          'host_clang%': 1,
+        }, {
+          'host_clang%': 0,
+        }],
+        # linux_use_bundled_gold: whether to use the gold linker binary checked
+        # into third_party/binutils.  Force this off via GYP_DEFINES when you
+        # are using a custom toolchain and need to control -B in ldflags.
+        # Do not use 32-bit gold on 32-bit hosts as it runs out address space
+        # for component=static_library builds.
+        ['(OS=="linux" or OS=="android") and (target_arch=="x64" or target_arch=="arm" or (target_arch=="ia32" and host_arch=="x64"))', {
+          'linux_use_bundled_gold%': 1,
+        }, {
+          'linux_use_bundled_gold%': 0,
+        }],
+      ],
+    },
+    'base_dir%': '<(base_dir)',
+    'clang_dir%': '<(clang_dir)',
+    'host_arch%': '<(host_arch)',
+    'host_clang%': '<(host_clang)',
+    'target_arch%': '<(target_arch)',
+    'v8_target_arch%': '<(v8_target_arch)',
+    'werror%': '-Werror',
+    'use_goma%': '<(use_goma)',
+    'gomadir%': '<(gomadir)',
+    'asan%': '<(asan)',
+    'lsan%': '<(lsan)',
+    'msan%': '<(msan)',
+    'tsan%': '<(tsan)',
+    'sanitizer_coverage%': '<(sanitizer_coverage)',
+    'use_custom_libcxx%': '<(use_custom_libcxx)',
+    'linux_use_bundled_gold%': '<(linux_use_bundled_gold)',
+    'use_lto%': '<(use_lto)',
+    'cfi_vptr%': '<(cfi_vptr)',
+    'cfi_diag%': '<(cfi_diag)',
+    'cfi_blacklist%': '<(cfi_blacklist)',
+    'test_isolation_mode%': '<(test_isolation_mode)',
+    'fastbuild%': '<(fastbuild)',
+    'coverage%': '<(coverage)',
+    'has_valgrind%': '<(has_valgrind)',
+
+    # Add a simple extras solely for the purpose of the cctests
+    'v8_extra_library_files': ['../test/cctest/test-extra.js'],
+    'v8_experimental_extra_library_files': ['../test/cctest/test-experimental-extra.js'],
+
+    # .gyp files or targets should set v8_code to 1 if they build V8 specific
+    # code, as opposed to external code.  This variable is used to control such
+    # things as the set of warnings to enable, and whether warnings are treated
+    # as errors.
+    'v8_code%': 0,
+
+    # Speeds up Debug builds:
+    # 0 - Compiler optimizations off (debuggable) (default). This may
+    #     be 5x slower than Release (or worse).
+    # 1 - Turn on optimizations and disable slow DCHECKs, but leave
+    #     V8_ENABLE_CHECKS and most other assertions enabled.  This may cause
+    #     some v8 tests to fail in the Debug configuration.  This roughly
+    #     matches the performance of a Release build and can be used by
+    #     embedders that need to build their own code as debug but don't want
+    #     or need a debug version of V8. This should produce near-release
+    #     speeds.
+    'v8_optimized_debug%': 0,
+
+    # Use external files for startup data blobs:
+    # the JS builtins sources and the start snapshot.
+    # Embedders that don't use standalone.gypi will need to add
+    # their own default value.
+    'v8_use_external_startup_data%': 1,
+
+    # Relative path to icu.gyp from this file.
+    'icu_gyp_path': '../third_party/icu/icu.gyp',
+
+    'conditions': [
+      ['(v8_target_arch=="arm" and host_arch!="arm") or \
+        (v8_target_arch=="arm64" and host_arch!="arm64") or \
+        (v8_target_arch=="mipsel" and host_arch!="mipsel") or \
+        (v8_target_arch=="mips64el" and host_arch!="mips64el") or \
+        (v8_target_arch=="x64" and host_arch!="x64") or \
+        (OS=="android" or OS=="qnx")', {
+        'want_separate_host_toolset': 1,
+      }, {
+        'want_separate_host_toolset': 0,
+      }],
+      ['OS == "win"', {
+        'os_posix%': 0,
+      }, {
+        'os_posix%': 1,
+      }],
+      ['OS=="win" and use_goma==1', {
+        # goma doesn't support pch yet.
+        'chromium_win_pch': 0,
+        # goma doesn't support PDB yet.
+        'fastbuild%': 1,
+      }],
+      ['((v8_target_arch=="ia32" or v8_target_arch=="x64" or v8_target_arch=="x87") and \
+        (OS=="linux" or OS=="mac")) or (v8_target_arch=="ppc64" and OS=="linux")', {
+        'v8_enable_gdbjit%': 1,
+      }, {
+        'v8_enable_gdbjit%': 0,
+      }],
+      ['(OS=="linux" or OS=="mac") and (target_arch=="ia32" or target_arch=="x64") and \
+        (v8_target_arch!="x87" and v8_target_arch!="x32")', {
+        'clang%': 1,
+      }, {
+        'clang%': 0,
+      }],
+      ['asan==1 or lsan==1 or msan==1 or tsan==1', {
+        'clang%': 1,
+        'use_allocator%': 'none',
+      }],
+      ['asan==1 and OS=="linux"', {
+        'use_custom_libcxx%': 1,
+      }],
+      ['tsan==1', {
+        'use_custom_libcxx%': 1,
+      }],
+      ['msan==1', {
+        # Use a just-built, MSan-instrumented libc++ instead of the system-wide
+        # libstdc++. This is required to avoid false positive reports whenever
+        # the C++ standard library is used.
+        'use_custom_libcxx%': 1,
+      }],
+      ['cfi_vptr==1', {
+        'use_lto%': 1,
+      }],
+      ['OS=="android"', {
+        # Location of Android NDK.
+        'variables': {
+          'variables': {
+            # The Android toolchain needs to use the absolute path to the NDK
+            # because it is used at different levels in the GYP files.
+            'android_ndk_root%': '<(base_dir)/third_party/android_tools/ndk/',
+            'android_host_arch%': "<!(uname -m | sed -e 's/i[3456]86/x86/')",
+            'host_os%': "<!(uname -s | sed -e 's/Linux/linux/;s/Darwin/mac/')",
+            'os_folder_name%': "<!(uname -s | sed -e 's/Linux/linux/;s/Darwin/darwin/')",
+          },
+
+          # Copy conditionally-set variables out one scope.
+          'android_ndk_root%': '<(android_ndk_root)',
+          'host_os%': '<(host_os)',
+          'os_folder_name%': '<(os_folder_name)',
+
+          'conditions': [
+            ['target_arch == "ia32"', {
+              'android_toolchain%': '<(android_ndk_root)/toolchains/x86-4.9/prebuilt/<(os_folder_name)-<(android_host_arch)/bin',
+              'android_target_arch%': 'x86',
+              'android_target_platform%': '16',
+              'arm_version%': 'default',
+            }],
+            ['target_arch == "x64"', {
+              'android_toolchain%': '<(android_ndk_root)/toolchains/x86_64-4.9/prebuilt/<(os_folder_name)-<(android_host_arch)/bin',
+              'android_target_arch%': 'x86_64',
+              'android_target_platform%': '21',
+              'arm_version%': 'default',
+            }],
+            ['target_arch=="arm"', {
+              'android_toolchain%': '<(android_ndk_root)/toolchains/arm-linux-androideabi-4.9/prebuilt/<(os_folder_name)-<(android_host_arch)/bin',
+              'android_target_arch%': 'arm',
+              'android_target_platform%': '16',
+              'arm_version%': 7,
+            }],
+            ['target_arch == "arm64"', {
+              'android_toolchain%': '<(android_ndk_root)/toolchains/aarch64-linux-android-4.9/prebuilt/<(os_folder_name)-<(android_host_arch)/bin',
+              'android_target_arch%': 'arm64',
+              'android_target_platform%': '21',
+              'arm_version%': 'default',
+            }],
+            ['target_arch == "mipsel"', {
+              'android_toolchain%': '<(android_ndk_root)/toolchains/mipsel-linux-android-4.9/prebuilt/<(os_folder_name)-<(android_host_arch)/bin',
+              'android_target_arch%': 'mips',
+              'android_target_platform%': '16',
+              'arm_version%': 'default',
+            }],
+            ['target_arch == "mips64el"', {
+              'android_toolchain%': '<(android_ndk_root)/toolchains/mips64el-linux-android-4.9/prebuilt/<(os_folder_name)-<(android_host_arch)/bin',
+              'android_target_arch%': 'mips64',
+              'android_target_platform%': '21',
+              'arm_version%': 'default',
+            }],
+          ],
+        },
+
+        # Copy conditionally-set variables out one scope.
+        'android_target_arch%': '<(android_target_arch)',
+        'android_target_platform%': '<(android_target_platform)',
+        'android_toolchain%': '<(android_toolchain)',
+        'arm_version%': '<(arm_version)',
+        'host_os%': '<(host_os)',
+
+        'conditions': [
+          ['android_ndk_root==""', {
+            'variables': {
+              'android_sysroot': '<(android_toolchain)/sysroot/',
+              'android_stl': '<(android_toolchain)/sources/cxx-stl/',
+            },
+            'conditions': [
+              ['target_arch=="x64"', {
+                'android_lib': '<(android_sysroot)/usr/lib64',
+              }, {
+                'android_lib': '<(android_sysroot)/usr/lib',
+              }],
+            ],
+            'android_libcpp_include': '<(android_stl)/llvm-libc++/libcxx/include',
+            'android_libcpp_abi_include': '<(android_stl)/llvm-libc++abi/libcxxabi/include',
+            'android_libcpp_libs': '<(android_stl)/llvm-libc++/libs',
+            'android_support_include': '<(android_toolchain)/sources/android/support/include',
+            'android_sysroot': '<(android_sysroot)',
+          }, {
+            'variables': {
+              'android_sysroot': '<(android_ndk_root)/platforms/android-<(android_target_platform)/arch-<(android_target_arch)',
+              'android_stl': '<(android_ndk_root)/sources/cxx-stl/',
+            },
+            'conditions': [
+              ['target_arch=="x64"', {
+                'android_lib': '<(android_sysroot)/usr/lib64',
+              }, {
+                'android_lib': '<(android_sysroot)/usr/lib',
+              }],
+            ],
+            'android_libcpp_include': '<(android_stl)/llvm-libc++/libcxx/include',
+            'android_libcpp_abi_include': '<(android_stl)/llvm-libc++abi/libcxxabi/include',
+            'android_libcpp_libs': '<(android_stl)/llvm-libc++/libs',
+            'android_support_include': '<(android_ndk_root)/sources/android/support/include',
+            'android_sysroot': '<(android_sysroot)',
+          }],
+        ],
+        'android_libcpp_library': 'c++_static',
+      }],  # OS=="android"
+      ['host_clang==1', {
+        'conditions':[
+          ['OS=="android"', {
+            'host_ld': '<!(which ld)',
+            'host_ranlib': '<!(which ranlib)',
+          }],
+        ],
+        'host_cc': '<(clang_dir)/bin/clang',
+        'host_cxx': '<(clang_dir)/bin/clang++',
+      }, {
+        'host_cc': '<!(which gcc)',
+        'host_cxx': '<!(which g++)',
+      }],
+    ],
+    # Default ARM variable settings.
+    'arm_version%': 'default',
+    'arm_fpu%': 'vfpv3',
+    'arm_float_abi%': 'default',
+    'arm_thumb': 'default',
+
+    # Default MIPS variable settings.
+    'mips_arch_variant%': 'r2',
+    # Possible values fp32, fp64, fpxx.
+    # fp32 - 32 32-bit FPU registers are available, doubles are placed in
+    #        register pairs.
+    # fp64 - 32 64-bit FPU registers are available.
+    # fpxx - compatibility mode, it chooses fp32 or fp64 depending on runtime
+    #        detection
+    'mips_fpu_mode%': 'fp32',
+
+    # Indicates if gcmole tools are downloaded by a hook.
+    'gcmole%': 0,
+  },
+  'target_defaults': {
+    'variables': {
+      'v8_code%': '<(v8_code)',
+      'clang_warning_flags': [
+        # TODO(thakis): https://crbug.com/604888
+        '-Wno-undefined-var-template',
+      ],
+      'conditions':[
+        ['OS=="android"', {
+          'host_os%': '<(host_os)',
+        }],
+      ],
+    },
+    'includes': [ 'set_clang_warning_flags.gypi', ],
+    'default_configuration': 'Debug',
+    'configurations': {
+      'DebugBaseCommon': {
+        'conditions': [
+          ['OS=="aix"', {
+            'cflags': [ '-g', '-Og', '-gxcoff' ],
+          }, {
+            'cflags': [ '-g', '-O0' ],
+          }],
+        ],
+      },
+      'Optdebug': {
+        'inherit_from': [ 'DebugBaseCommon', 'DebugBase1' ],
+      },
+      'Debug': {
+        # Xcode insists on this empty entry.
+      },
+      'Release': {
+        'cflags+': ['<@(release_extra_cflags)'],
+      },
+      'conditions': [
+        ['OS=="win"', {
+          'Optdebug_x64': {
+            'inherit_from': ['Optdebug'],
+          },
+          'Debug_x64': {
+            'inherit_from': ['Debug'],
+          },
+          'Release_x64': {
+            'inherit_from': ['Release'],
+          },
+        }],
+      ],
+    },
+    'conditions':[
+      ['clang==0', {
+        'cflags+': ['-Wno-sign-compare',],
+      }],
+      ['clang==1 or host_clang==1', {
+        # This is here so that all files get recompiled after a clang roll and
+        # when turning clang on or off.
+        # (defines are passed via the command line, and build systems rebuild
+        # things when their commandline changes). Nothing should ever read this
+        # define.
+        'defines': ['CR_CLANG_REVISION=<!(python <(DEPTH)/tools/clang/scripts/update.py --print-revision)'],
+        'conditions': [
+          ['host_clang==1', {
+            'target_conditions': [
+              ['_toolset=="host"', {
+                'cflags+': [
+                  '-Wno-format-pedantic',
+                 ],
+              }],
+           ],
+          }],
+          ['clang==1', {
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags+': [
+                  '-Wno-format-pedantic',
+                 ],
+              }],
+           ],
+          }],
+        ],
+      }],
+      ['clang==1 and target_arch=="ia32"', {
+        'cflags': ['-mstack-alignment=16', '-mstackrealign'],
+      }],
+      ['fastbuild!=0', {
+        'conditions': [
+          ['OS=="win" and fastbuild==1', {
+            'msvs_settings': {
+              'VCLinkerTool': {
+                # This tells the linker to generate .pdbs, so that
+                # we can get meaningful stack traces.
+                'GenerateDebugInformation': 'true',
+              },
+              'VCCLCompilerTool': {
+                # No debug info to be generated by compiler.
+                'DebugInformationFormat': '0',
+              },
+            },
+          }],
+        ],
+      }],  # fastbuild!=0
+    ],
+    'target_conditions': [
+      ['v8_code == 0', {
+        'defines!': [
+          'DEBUG',
+        ],
+        'conditions': [
+          ['os_posix == 1 and OS != "mac"', {
+            # We don't want to get warnings from third-party code,
+            # so remove any existing warning-enabling flags like -Wall.
+            'cflags!': [
+              '-pedantic',
+              '-Wall',
+              '-Werror',
+              '-Wextra',
+              '-Wshorten-64-to-32',
+            ],
+            'cflags+': [
+              # Clang considers the `register` keyword as deprecated, but
+              # ICU uses it all over the place.
+              '-Wno-deprecated-register',
+              # ICU uses its own deprecated functions.
+              '-Wno-deprecated-declarations',
+              # ICU prefers `a && b || c` over `(a && b) || c`.
+              '-Wno-logical-op-parentheses',
+              # ICU has some `unsigned < 0` checks.
+              '-Wno-tautological-compare',
+              # uresdata.c has switch(RES_GET_TYPE(x)) code. The
+              # RES_GET_TYPE macro returns an UResType enum, but some switch
+              # statement contains case values that aren't part of that
+              # enum (e.g. URES_TABLE32 which is in UResInternalType). This
+              # is on purpose.
+              '-Wno-switch',
+            ],
+            'cflags_cc!': [
+              '-Wnon-virtual-dtor',
+            ],
+          }],
+          ['OS == "mac"', {
+            'xcode_settings': {
+              'GCC_TREAT_WARNINGS_AS_ERRORS': 'NO',    # -Werror
+            },
+          }],
+          ['OS == "win"', {
+            'msvs_settings': {
+              'VCCLCompilerTool': {
+                'WarnAsError': 'false',
+              },
+            },
+          }],
+        ],
+      }],
+    ],
+  },
+  'conditions': [
+    ['os_posix==1 and OS!="mac"', {
+      'target_defaults': {
+        'conditions': [
+          # Common options for AddressSanitizer, LeakSanitizer,
+          # ThreadSanitizer, MemorySanitizer and CFI builds.
+          ['asan==1 or lsan==1 or tsan==1 or msan==1 or cfi_vptr==1', {
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags': [
+                  '-fno-omit-frame-pointer',
+                  '-gline-tables-only',
+                ],
+                'cflags!': [
+                  '-fomit-frame-pointer',
+                ],
+              }],
+            ],
+          }],
+          ['asan==1', {
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags': [
+                  '-fsanitize=address',
+                ],
+                'ldflags': [
+                  '-fsanitize=address',
+                ],
+                'defines': [
+                  'ADDRESS_SANITIZER',
+                ],
+              }],
+            ],
+          }],
+          ['lsan==1', {
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags': [
+                  '-fsanitize=leak',
+                ],
+                'ldflags': [
+                  '-fsanitize=leak',
+                ],
+                'defines': [
+                  'LEAK_SANITIZER',
+                ],
+              }],
+            ],
+          }],
+          ['tsan==1', {
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags': [
+                  '-fsanitize=thread',
+                ],
+                'ldflags': [
+                  '-fsanitize=thread',
+                ],
+                'defines': [
+                  'THREAD_SANITIZER',
+                ],
+              }],
+            ],
+          }],
+          ['msan==1', {
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags': [
+                  '-fsanitize=memory',
+                  '-fsanitize-memory-track-origins=<(msan_track_origins)',
+                  '-fPIC',
+                ],
+                'ldflags': [
+                  '-fsanitize=memory',
+                  '-pie',
+                ],
+                'defines': [
+                  'MEMORY_SANITIZER',
+                ],
+              }],
+            ],
+          }],
+          ['use_custom_libcxx==1', {
+            'dependencies': [
+              '<(DEPTH)/buildtools/third_party/libc++/libc++.gyp:libcxx_proxy',
+            ],
+          }],
+          ['sanitizer_coverage!=0', {
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags': [
+                  '-fsanitize-coverage=<(sanitizer_coverage)',
+                ],
+                'defines': [
+                  'SANITIZER_COVERAGE',
+                ],
+              }],
+            ],
+          }],
+          ['linux_use_bundled_gold==1 and not (clang==0 and use_lto==1)', {
+            # Put our binutils, which contains gold in the search path. We pass
+            # the path to gold to the compiler. gyp leaves unspecified what the
+            # cwd is when running the compiler, so the normal gyp path-munging
+            # fails us. This hack gets the right path.
+            #
+            # Disabled when using GCC LTO because GCC also uses the -B search
+            # path at link time to find "as", and our bundled "as" can only
+            # target x86.
+            'ldflags': [
+              # Note, Chromium allows ia32 host arch as well, we limit this to
+              # x64 in v8.
+              '-B<(base_dir)/third_party/binutils/Linux_x64/Release/bin',
+            ],
+          }],
+        ],
+      },
+    }],
+    ['OS=="mac"', {
+      'target_defaults': {
+       'conditions': [
+          ['asan==1', {
+            'xcode_settings': {
+              # FIXME(machenbach): This is outdated compared to common.gypi.
+              'OTHER_CFLAGS+': [
+                '-fno-omit-frame-pointer',
+                '-gline-tables-only',
+                '-fsanitize=address',
+                '-w',  # http://crbug.com/162783
+              ],
+              'OTHER_CFLAGS!': [
+                '-fomit-frame-pointer',
+              ],
+              'defines': [
+                'ADDRESS_SANITIZER',
+              ],
+            },
+            'dependencies': [
+              '<(DEPTH)/gypfiles/mac/asan.gyp:asan_dynamic_runtime',
+            ],
+            'target_conditions': [
+              ['_type!="static_library"', {
+                'xcode_settings': {'OTHER_LDFLAGS': ['-fsanitize=address']},
+              }],
+            ],
+          }],
+          ['sanitizer_coverage!=0', {
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags': [
+                  '-fsanitize-coverage=<(sanitizer_coverage)',
+                ],
+                'defines': [
+                  'SANITIZER_COVERAGE',
+                ],
+              }],
+            ],
+          }],
+        ],
+      },  # target_defaults
+    }],  # OS=="mac"
+    ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris" \
+       or OS=="netbsd" or OS=="aix"', {
+      'target_defaults': {
+        'cflags': [
+          '-Wall',
+          '<(werror)',
+          '-Wno-unused-parameter',
+          '-Wno-long-long',
+          '-pthread',
+          '-pedantic',
+          '-Wmissing-field-initializers',
+          '-Wno-gnu-zero-variadic-macro-arguments',
+        ],
+        'cflags_cc': [
+          '-Wnon-virtual-dtor',
+          '-fno-exceptions',
+          '-fno-rtti',
+          '-std=gnu++11',
+        ],
+        'ldflags': [ '-pthread', ],
+        'conditions': [
+          # Don't warn about TRACE_EVENT_* macros with zero arguments passed to
+          # ##__VA_ARGS__. C99 strict mode prohibits having zero variadic macro
+          # arguments in gcc.
+          [ 'clang==0', {
+            'cflags!' : [
+              '-pedantic' ,
+              # Don't warn about unrecognized command line option.
+              '-Wno-gnu-zero-variadic-macro-arguments',
+            ],
+          }],
+          [ 'clang==1 and (v8_target_arch=="x64" or v8_target_arch=="arm64" \
+            or v8_target_arch=="mips64el")', {
+            'cflags': [ '-Wshorten-64-to-32' ],
+          }],
+          [ 'host_arch=="ppc64" and OS!="aix"', {
+            'cflags': [ '-mminimal-toc' ],
+          }],
+          [ 'visibility=="hidden" and v8_enable_backtrace==0', {
+            'cflags': [ '-fvisibility=hidden' ],
+          }],
+          [ 'component=="shared_library"', {
+            'cflags': [ '-fPIC', ],
+          }],
+          [ 'clang==0 and coverage==1', {
+            'cflags': [ '-fprofile-arcs', '-ftest-coverage'],
+            'ldflags': [ '-fprofile-arcs'],
+          }],
+        ],
+      },
+    }],
+    # 'OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris"
+    #  or OS=="netbsd"'
+    ['OS=="qnx"', {
+      'target_defaults': {
+        'cflags': [
+          '-Wall',
+          '<(werror)',
+          '-Wno-unused-parameter',
+          # Don't warn about the "struct foo f = {0};" initialization pattern.
+          '-Wno-missing-field-initializers',
+          '-Wno-gnu-zero-variadic-macro-arguments',
+        ],
+        'cflags_cc': [
+          '-Wnon-virtual-dtor',
+          '-fno-exceptions',
+          '-fno-rtti',
+          '-std=gnu++11',
+        ],
+        'conditions': [
+          [ 'visibility=="hidden"', {
+            'cflags': [ '-fvisibility=hidden' ],
+          }],
+          [ 'component=="shared_library"', {
+            'cflags': [ '-fPIC' ],
+          }],
+        ],
+        'target_conditions': [
+          [ '_toolset=="host" and host_os=="linux"', {
+            'cflags': [ '-pthread' ],
+            'ldflags': [ '-pthread' ],
+            'libraries': [ '-lrt' ],
+          }],
+          [ '_toolset=="target"', {
+            'cflags': [ '-Wno-psabi' ],
+            'libraries': [ '-lbacktrace', '-lsocket', '-lm' ],
+          }],
+        ],
+      },
+    }],  # OS=="qnx"
+    ['OS=="win"', {
+      'target_defaults': {
+        'defines': [
+          '_CRT_SECURE_NO_DEPRECATE',
+          '_CRT_NONSTDC_NO_DEPRECATE',
+          '_USING_V110_SDK71_',
+        ],
+        'conditions': [
+          ['component=="static_library"', {
+            'defines': [
+              '_HAS_EXCEPTIONS=0',
+            ],
+          }],
+        ],
+        'msvs_cygwin_dirs': ['<(DEPTH)/third_party/cygwin'],
+        'msvs_disabled_warnings': [
+          # C4091: 'typedef ': ignored on left of 'X' when no variable is
+          #                    declared.
+          # This happens in a number of Windows headers. Dumb.
+          4091,
+
+          # C4127: conditional expression is constant
+          # This warning can in theory catch dead code and other problems, but
+          # triggers in far too many desirable cases where the conditional
+          # expression is either set by macros or corresponds some legitimate
+          # compile-time constant expression (due to constant template args,
+          # conditionals comparing the sizes of different types, etc.).  Some of
+          # these can be worked around, but it's not worth it.
+          4127,
+
+          # C4351: new behavior: elements of array 'array' will be default
+          #        initialized
+          # This is a silly "warning" that basically just alerts you that the
+          # compiler is going to actually follow the language spec like it's
+          # supposed to, instead of not following it like old buggy versions
+          # did.  There's absolutely no reason to turn this on.
+          4351,
+
+          # C4355: 'this': used in base member initializer list
+          # It's commonly useful to pass |this| to objects in a class'
+          # initializer list.  While this warning can catch real bugs, most of
+          # the time the constructors in question don't attempt to call methods
+          # on the passed-in pointer (until later), and annotating every legit
+          # usage of this is simply more hassle than the warning is worth.
+          4355,
+
+          # C4503: 'identifier': decorated name length exceeded, name was
+          #        truncated
+          # This only means that some long error messages might have truncated
+          # identifiers in the presence of lots of templates.  It has no effect
+          # on program correctness and there's no real reason to waste time
+          # trying to prevent it.
+          4503,
+
+          # Warning C4589 says: "Constructor of abstract class ignores
+          # initializer for virtual base class." Disable this warning because it
+          # is flaky in VS 2015 RTM. It triggers on compiler generated
+          # copy-constructors in some cases.
+          4589,
+
+          # C4611: interaction between 'function' and C++ object destruction is
+          #        non-portable
+          # This warning is unavoidable when using e.g. setjmp/longjmp.  MSDN
+          # suggests using exceptions instead of setjmp/longjmp for C++, but
+          # Chromium code compiles without exception support.  We therefore have
+          # to use setjmp/longjmp for e.g. JPEG decode error handling, which
+          # means we have to turn off this warning (and be careful about how
+          # object destruction happens in such cases).
+          4611,
+
+          # TODO(jochen): These warnings are level 4. They will be slowly
+          # removed as code is fixed.
+          4100, # Unreferenced formal parameter
+          4121, # Alignment of a member was sensitive to packing
+          4244, # Conversion from 'type1' to 'type2', possible loss of data
+          4302, # Truncation from 'type 1' to 'type 2'
+          4309, # Truncation of constant value
+          4311, # Pointer truncation from 'type' to 'type'
+          4312, # Conversion from 'type1' to 'type2' of greater size
+          4505, # Unreferenced local function has been removed
+          4510, # Default constructor could not be generated
+          4512, # Assignment operator could not be generated
+          4610, # Object can never be instantiated
+          4800, # Forcing value to bool.
+          4838, # Narrowing conversion. Doesn't seem to be very useful.
+          4995, # 'X': name was marked as #pragma deprecated
+          4996, # 'X': was declared deprecated (for GetVersionEx).
+
+          # These are variable shadowing warnings that are new in VS2015. We
+          # should work through these at some point -- they may be removed from
+          # the RTM release in the /W4 set.
+          4456, 4457, 4458, 4459,
+        ],
+        'msvs_settings': {
+          'VCCLCompilerTool': {
+            'MinimalRebuild': 'false',
+            'BufferSecurityCheck': 'true',
+            'EnableFunctionLevelLinking': 'true',
+            'RuntimeTypeInfo': 'false',
+            'WarningLevel': '3',
+            'WarnAsError': 'true',
+            'DebugInformationFormat': '3',
+            'Detect64BitPortabilityProblems': 'false',
+            'conditions': [
+              [ 'msvs_multi_core_compile', {
+                'AdditionalOptions': ['/MP'],
+              }],
+              ['component=="shared_library"', {
+                'ExceptionHandling': '1',  # /EHsc
+              }, {
+                'ExceptionHandling': '0',
+              }],
+            ],
+          },
+          'VCLibrarianTool': {
+            'AdditionalOptions': ['/ignore:4221'],
+            'conditions': [
+              ['v8_target_arch=="x64"', {
+                'TargetMachine': '17',  # x64
+              }, {
+                'TargetMachine': '1',  # ia32
+              }],
+            ],
+          },
+          'VCLinkerTool': {
+            'AdditionalDependencies': [
+              'ws2_32.lib',
+            ],
+            'GenerateDebugInformation': 'true',
+            'MapFileName': '$(OutDir)\\$(TargetName).map',
+            'ImportLibrary': '$(OutDir)\\lib\\$(TargetName).lib',
+            'FixedBaseAddress': '1',
+            # LinkIncremental values:
+            #   0 == default
+            #   1 == /INCREMENTAL:NO
+            #   2 == /INCREMENTAL
+            'LinkIncremental': '1',
+            # SubSystem values:
+            #   0 == not set
+            #   1 == /SUBSYSTEM:CONSOLE
+            #   2 == /SUBSYSTEM:WINDOWS
+            'SubSystem': '1',
+
+            'conditions': [
+              ['v8_enable_i18n_support==1', {
+                'AdditionalDependencies': [
+                  'advapi32.lib',
+                ],
+              }],
+              ['v8_target_arch=="x64"', {
+                'MinimumRequiredVersion': '5.02',  # Server 2003.
+                'TargetMachine': '17',  # x64
+              }, {
+                'MinimumRequiredVersion': '5.01',  # XP.
+                'TargetMachine': '1',  # ia32
+              }],
+            ],
+          },
+          'conditions': [
+            ['clang==1', {
+              'VCCLCompilerTool': {
+                'AdditionalOptions': [
+                  # Don't warn about unused function parameters.
+                  # (This is also used on other platforms.)
+                  '-Wno-unused-parameter',
+                  # Don't warn about the "struct foo f = {0};" initialization
+                  # pattern.
+                  '-Wno-missing-field-initializers',
+
+                  # Many files use intrinsics without including this header.
+                  # TODO(hans): Fix those files, or move this to sub-GYPs.
+                  '/FIIntrin.h',
+
+                  # TODO(hans): Make this list shorter eventually, http://crbug.com/504657
+                  '-Qunused-arguments',  # http://crbug.com/504658
+                  '-Wno-microsoft-enum-value',  # http://crbug.com/505296
+                  '-Wno-unknown-pragmas',  # http://crbug.com/505314
+                  '-Wno-microsoft-cast',  # http://crbug.com/550065
+                ],
+              },
+            }],
+            ['clang==1 and MSVS_VERSION == "2013"', {
+              'VCCLCompilerTool': {
+                'AdditionalOptions': [
+                  '-fmsc-version=1800',
+                ],
+              },
+            }],
+            ['clang==1 and MSVS_VERSION == "2015"', {
+              'VCCLCompilerTool': {
+                'AdditionalOptions': [
+                  '-fmsc-version=1900',
+                ],
+              },
+            }],
+          ],
+        },
+      },
+    }],  # OS=="win"
+    ['OS=="mac"', {
+      'xcode_settings': {
+        'SDKROOT': 'macosx',
+        'SYMROOT': '<(DEPTH)/xcodebuild',
+      },
+      'target_defaults': {
+        'xcode_settings': {
+          'ALWAYS_SEARCH_USER_PATHS': 'NO',
+          'GCC_C_LANGUAGE_STANDARD': 'c99',         # -std=c99
+          'GCC_CW_ASM_SYNTAX': 'NO',                # No -fasm-blocks
+          'GCC_DYNAMIC_NO_PIC': 'NO',               # No -mdynamic-no-pic
+                                                    # (Equivalent to -fPIC)
+          'GCC_ENABLE_CPP_EXCEPTIONS': 'NO',        # -fno-exceptions
+          'GCC_ENABLE_CPP_RTTI': 'NO',              # -fno-rtti
+          'GCC_ENABLE_PASCAL_STRINGS': 'NO',        # No -mpascal-strings
+          # GCC_INLINES_ARE_PRIVATE_EXTERN maps to -fvisibility-inlines-hidden
+          'GCC_INLINES_ARE_PRIVATE_EXTERN': 'YES',
+          'GCC_SYMBOLS_PRIVATE_EXTERN': 'YES',      # -fvisibility=hidden
+          'GCC_THREADSAFE_STATICS': 'NO',           # -fno-threadsafe-statics
+          'GCC_WARN_NON_VIRTUAL_DESTRUCTOR': 'YES', # -Wnon-virtual-dtor
+          # MACOSX_DEPLOYMENT_TARGET maps to -mmacosx-version-min
+          'MACOSX_DEPLOYMENT_TARGET': '<(mac_deployment_target)',
+          'PREBINDING': 'NO',                       # No -Wl,-prebind
+          'SYMROOT': '<(DEPTH)/xcodebuild',
+          'USE_HEADERMAP': 'NO',
+          'OTHER_CFLAGS': [
+            '-fno-strict-aliasing',
+          ],
+          'WARNING_CFLAGS': [
+            '-Wall',
+            '-Wendif-labels',
+            '-Wno-unused-parameter',
+            # Don't warn about the "struct foo f = {0};" initialization pattern.
+            '-Wno-missing-field-initializers',
+            '-Wno-gnu-zero-variadic-macro-arguments',
+          ],
+        },
+        'conditions': [
+          ['werror==""', {
+            'xcode_settings': {'GCC_TREAT_WARNINGS_AS_ERRORS': 'NO'},
+          }, {
+            'xcode_settings': {'GCC_TREAT_WARNINGS_AS_ERRORS': 'YES'},
+          }],
+          ['clang==1', {
+            'xcode_settings': {
+              'GCC_VERSION': 'com.apple.compilers.llvm.clang.1_0',
+              'CLANG_CXX_LANGUAGE_STANDARD': 'c++11',  # -std=c++11
+            },
+            'conditions': [
+              ['clang_xcode==0', {
+                'xcode_settings': {
+                  'CC': '<(clang_dir)/bin/clang',
+                  'LDPLUSPLUS': '<(clang_dir)/bin/clang++',
+                  'CLANG_CXX_LIBRARY': 'libc++'
+                },
+              }],
+              ['v8_target_arch=="x64" or v8_target_arch=="arm64" \
+                or v8_target_arch=="mips64el"', {
+                'xcode_settings': {'WARNING_CFLAGS': ['-Wshorten-64-to-32']},
+              }],
+            ],
+          }],
+        ],
+        'target_conditions': [
+          ['_type!="static_library"', {
+            'xcode_settings': {'OTHER_LDFLAGS': ['-Wl,-search_paths_first']},
+          }],
+        ],  # target_conditions
+      },  # target_defaults
+    }],  # OS=="mac"
+    ['OS=="android"', {
+      'target_defaults': {
+        'defines': [
+          'ANDROID',
+          'V8_ANDROID_LOG_STDOUT',
+        ],
+        'configurations': {
+          'Release': {
+            'cflags': [
+              '-fomit-frame-pointer',
+            ],
+          },  # Release
+        },  # configurations
+        'cflags': [ '-Wno-abi', '-Wall', '-W', '-Wno-unused-parameter'],
+        'cflags_cc': [ '-Wnon-virtual-dtor', '-fno-rtti', '-fno-exceptions',
+                       '-std=gnu++11' ],
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'cflags!': [
+              '-pthread',  # Not supported by Android toolchain.
+            ],
+            'cflags': [
+              '-ffunction-sections',
+              '-funwind-tables',
+              '-fstack-protector',
+              '-fno-short-enums',
+              '-finline-limit=64',
+              '-Wa,--noexecstack',
+              '--sysroot=<(android_sysroot)',
+            ],
+            'cflags_cc': [
+              '-isystem<(android_libcpp_include)',
+              '-isystem<(android_libcpp_abi_include)',
+              '-isystem<(android_support_include)',
+            ],
+            'defines': [
+              'ANDROID',
+              #'__GNU_SOURCE=1',  # Necessary for clone()
+              'HAVE_OFF64_T',
+              'HAVE_SYS_UIO_H',
+              'ANDROID_BINSIZE_HACK', # Enable temporary hacks to reduce binsize.
+            ],
+            'ldflags!': [
+              '-pthread',  # Not supported by Android toolchain.
+            ],
+            'ldflags': [
+              '-Wl,--no-undefined',
+              '--sysroot=<(android_sysroot)',
+              '-nostdlib',
+            ],
+            'libraries!': [
+                '-lrt',  # librt is built into Bionic.
+                # Not supported by Android toolchain.
+                # Where do these come from?  Can't find references in
+                # any Chromium gyp or gypi file.  Maybe they come from
+                # gyp itself?
+                '-lpthread', '-lnss3', '-lnssutil3', '-lsmime3', '-lplds4', '-lplc4', '-lnspr4',
+              ],
+              'libraries': [
+                '-l<(android_libcpp_library)',
+                '-latomic',
+                # Manually link the libgcc.a that the cross compiler uses.
+                '<!(<(android_toolchain)/*-gcc -print-libgcc-file-name)',
+                '-lc',
+                '-ldl',
+                '-lm',
+            ],
+            'conditions': [
+              ['target_arch == "arm"', {
+                'ldflags': [
+                  # Enable identical code folding to reduce size.
+                  '-Wl,--icf=safe',
+                ],
+              }],
+              ['target_arch=="arm" and arm_version==7', {
+                'cflags': [
+                  '-march=armv7-a',
+                  '-mtune=cortex-a8',
+                  '-mfpu=vfp3',
+                ],
+                'ldflags': [
+                  '-L<(android_libcpp_libs)/armeabi-v7a',
+                ],
+              }],
+              ['target_arch=="arm" and arm_version < 7', {
+                'ldflags': [
+                  '-L<(android_libcpp_libs)/armeabi',
+                ],
+              }],
+              ['target_arch=="x64"', {
+                'ldflags': [
+                  '-L<(android_libcpp_libs)/x86_64',
+                ],
+              }],
+              ['target_arch=="arm64"', {
+                'ldflags': [
+                  '-L<(android_libcpp_libs)/arm64-v8a',
+                ],
+              }],
+              ['target_arch=="ia32" or target_arch=="x87"', {
+                # The x86 toolchain currently has problems with stack-protector.
+                'cflags!': [
+                  '-fstack-protector',
+                ],
+                'cflags': [
+                  '-fno-stack-protector',
+                ],
+                'ldflags': [
+                  '-L<(android_libcpp_libs)/x86',
+                ],
+              }],
+              ['target_arch=="mipsel"', {
+                # The mips toolchain currently has problems with stack-protector.
+                'cflags!': [
+                  '-fstack-protector',
+                  '-U__linux__'
+                ],
+                'cflags': [
+                  '-fno-stack-protector',
+                ],
+                'ldflags': [
+                  '-L<(android_libcpp_libs)/mips',
+                ],
+              }],
+              ['(target_arch=="arm" or target_arch=="arm64" or target_arch=="x64" or target_arch=="ia32") and component!="shared_library"', {
+                'cflags': [
+                  '-fPIE',
+                ],
+                'ldflags': [
+                  '-pie',
+                ],
+              }],
+            ],
+            'target_conditions': [
+              ['_type=="executable"', {
+                'conditions': [
+                  ['target_arch=="arm64" or target_arch=="x64"', {
+                    'ldflags': [
+                      '-Wl,-dynamic-linker,/system/bin/linker64',
+                    ],
+                  }, {
+                    'ldflags': [
+                      '-Wl,-dynamic-linker,/system/bin/linker',
+                    ],
+                  }]
+                ],
+                'ldflags': [
+                  '-Bdynamic',
+                  '-Wl,-z,nocopyreloc',
+                  # crtbegin_dynamic.o should be the last item in ldflags.
+                  '<(android_lib)/crtbegin_dynamic.o',
+                ],
+                'libraries': [
+                  # crtend_android.o needs to be the last item in libraries.
+                  # Do not add any libraries after this!
+                  '<(android_lib)/crtend_android.o',
+                ],
+              }],
+              ['_type=="shared_library"', {
+                'ldflags': [
+                  '-Wl,-shared,-Bsymbolic',
+                  '<(android_lib)/crtbegin_so.o',
+                ],
+              }],
+              ['_type=="static_library"', {
+                'ldflags': [
+                  # Don't export symbols from statically linked libraries.
+                  '-Wl,--exclude-libs=ALL',
+                ],
+              }],
+            ],
+          }],  # _toolset=="target"
+          # Settings for building host targets using the system toolchain.
+          ['_toolset=="host"', {
+            'cflags': [ '-pthread' ],
+            'ldflags': [ '-pthread' ],
+            'ldflags!': [
+              '-Wl,-z,noexecstack',
+              '-Wl,--gc-sections',
+              '-Wl,-O1',
+              '-Wl,--as-needed',
+            ],
+          }],
+        ],  # target_conditions
+      },  # target_defaults
+    }],  # OS=="android"
+    ['OS=="android" and clang==0', {
+      # Hardcode the compiler names in the Makefile so that
+      # it won't depend on the environment at make time.
+      'make_global_settings': [
+        ['LD', '<!(/bin/echo -n <(android_toolchain)/../*/bin/ld)'],
+        ['RANLIB', '<!(/bin/echo -n <(android_toolchain)/../*/bin/ranlib)'],
+        ['CC', '<!(/bin/echo -n <(android_toolchain)/*-gcc)'],
+        ['CXX', '<!(/bin/echo -n <(android_toolchain)/*-g++)'],
+        ['LD.host', '<(host_ld)'],
+        ['RANLIB.host', '<(host_ranlib)'],
+        ['CC.host', '<(host_cc)'],
+        ['CXX.host', '<(host_cxx)'],
+      ],
+    }],
+    ['clang!=1 and host_clang==1 and target_arch!="ia32" and target_arch!="x64"', {
+      'make_global_settings': [
+        ['CC.host', '<(clang_dir)/bin/clang'],
+        ['CXX.host', '<(clang_dir)/bin/clang++'],
+      ],
+    }],
+    ['clang==0 and host_clang==1 and target_arch!="ia32" and target_arch!="x64"', {
+      'target_conditions': [
+        ['_toolset=="host"', {
+          'cflags_cc': [ '-std=gnu++11', ],
+        }],
+      ],
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="host"', { 'cflags!': [ '-Wno-unused-local-typedefs' ]}],
+        ],
+      },
+    }],
+    ['clang==1 and "<(GENERATOR)"=="ninja"', {
+      # See http://crbug.com/110262
+      'target_defaults': {
+        'cflags': [ '-fcolor-diagnostics' ],
+        'xcode_settings': { 'OTHER_CFLAGS': [ '-fcolor-diagnostics' ] },
+      },
+    }],
+    ['clang==1 and ((OS!="mac" and OS!="ios") or clang_xcode==0) '
+        'and OS!="win" and "<(GENERATOR)"=="make"', {
+      'make_global_settings': [
+        ['CC', '<(clang_dir)/bin/clang'],
+        ['CXX', '<(clang_dir)/bin/clang++'],
+        ['CC.host', '$(CC)'],
+        ['CXX.host', '$(CXX)'],
+      ],
+    }],
+    ['clang==1 and ((OS!="mac" and OS!="ios") or clang_xcode==0) '
+        'and OS!="win" and "<(GENERATOR)"=="ninja"', {
+      'make_global_settings': [
+        ['CC', '<(clang_dir)/bin/clang'],
+        ['CXX', '<(clang_dir)/bin/clang++'],
+        ['CC.host', '$(CC)'],
+        ['CXX.host', '$(CXX)'],
+      ],
+    }],
+    ['clang==1 and OS=="win"', {
+      'make_global_settings': [
+        # On Windows, gyp's ninja generator only looks at CC.
+        ['CC', '<(clang_dir)/bin/clang-cl'],
+      ],
+    }],
+    ['OS=="linux" and target_arch=="arm" and host_arch!="arm" and clang==0 and "<(GENERATOR)"=="ninja"', {
+      # Set default ARM cross tools on linux.  These can be overridden
+      # using CC,CXX,CC.host and CXX.host environment variables.
+      'make_global_settings': [
+        ['CC', '<!(which arm-linux-gnueabihf-gcc)'],
+        ['CXX', '<!(which arm-linux-gnueabihf-g++)'],
+        ['CC.host', '<(host_cc)'],
+        ['CXX.host', '<(host_cxx)'],
+      ],
+    }],
+    # TODO(yyanagisawa): supports GENERATOR==make
+    #  make generator doesn't support CC_wrapper without CC
+    #  in make_global_settings yet.
+    ['use_goma==1 and ("<(GENERATOR)"=="ninja" or clang==1)', {
+      'conditions': [
+        ['coverage==1', {
+          # Wrap goma with coverage wrapper.
+          'make_global_settings': [
+            ['CC_wrapper', '<(base_dir)/gypfiles/coverage_wrapper.py <(gomadir)/gomacc'],
+            ['CXX_wrapper', '<(base_dir)/gypfiles/coverage_wrapper.py <(gomadir)/gomacc'],
+            ['CC.host_wrapper', '<(base_dir)/gypfiles/coverage_wrapper.py <(gomadir)/gomacc'],
+            ['CXX.host_wrapper', '<(base_dir)/gypfiles/coverage_wrapper.py <(gomadir)/gomacc'],
+          ],
+        }, {
+          # Use only goma wrapper.
+          'make_global_settings': [
+            ['CC_wrapper', '<(gomadir)/gomacc'],
+            ['CXX_wrapper', '<(gomadir)/gomacc'],
+            ['CC.host_wrapper', '<(gomadir)/gomacc'],
+            ['CXX.host_wrapper', '<(gomadir)/gomacc'],
+          ],
+        }],
+      ],
+    }, {
+      'conditions': [
+        ['coverage==1', {
+          # Use only coverage wrapper.
+          'make_global_settings': [
+            ['CC_wrapper', '<(base_dir)/gypfiles/coverage_wrapper.py'],
+            ['CXX_wrapper', '<(base_dir)/gypfiles/coverage_wrapper.py'],
+            ['CC.host_wrapper', '<(base_dir)/gypfiles/coverage_wrapper.py'],
+            ['CXX.host_wrapper', '<(base_dir)/gypfiles/coverage_wrapper.py'],
+          ],
+        }],
+      ],
+    }],
+    ['use_lto==1', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'cflags': [
+              '-flto',
+            ],
+          }],
+        ],
+      },
+    }],
+    ['use_lto==1 and clang==0', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'cflags': [
+              '-ffat-lto-objects',
+            ],
+          }],
+        ],
+      },
+    }],
+    ['use_lto==1 and clang==1', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'arflags': [
+              '--plugin', '<(clang_dir)/lib/LLVMgold.so',
+            ],
+            # Apply a lower optimization level with lto. Chromium does this
+            # for non-official builds only - a differentiation that doesn't
+            # exist in v8.
+            'ldflags': [
+              '-Wl,--plugin-opt,O1',
+            ],
+          }],
+        ],
+      },
+    }],
+    ['use_lto==1 and clang==0', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'ldflags': [
+              '-flto=32',
+            ],
+          }],
+        ],
+      },
+    }],
+    ['use_lto==1 and clang==1', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'ldflags': [
+              '-flto',
+            ],
+          }],
+        ],
+      },
+    }],
+    ['cfi_diag==1', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'cflags': [
+              '-fno-sanitize-trap=cfi',
+              '-fno-sanitize-recover=cfi',
+            ],
+            'cflags_cc!': [
+              '-fno-rtti',
+            ],
+            'cflags!': [
+              '-fno-rtti',
+            ],
+            'ldflags': [
+              '-fno-sanitize-trap=cfi',
+              '-fno-sanitize-recover=cfi',
+            ],
+          }],
+        ],
+      },
+    }],
+    ['cfi_vptr==1', {
+      'target_defaults': {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'cflags': [
+              '-fsanitize=cfi-vcall',
+              '-fsanitize=cfi-derived-cast',
+              '-fsanitize=cfi-unrelated-cast',
+              '-fsanitize-blacklist=<(cfi_blacklist)',
+            ],
+            'ldflags': [
+              '-fsanitize=cfi-vcall',
+              '-fsanitize=cfi-derived-cast',
+              '-fsanitize=cfi-unrelated-cast',
+            ],
+          }],
+        ],
+      },
+    }],
+  ],
+}
diff --git a/gypfiles/toolchain.gypi b/gypfiles/toolchain.gypi
new file mode 100644
index 0000000..bc3ee5e
--- /dev/null
+++ b/gypfiles/toolchain.gypi
@@ -0,0 +1,1394 @@
+# Copyright 2013 the V8 project authors. All rights reserved.
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+#       copyright notice, this list of conditions and the following
+#       disclaimer in the documentation and/or other materials provided
+#       with the distribution.
+#     * Neither the name of Google Inc. nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# Shared definitions for all V8-related targets.
+
+{
+  'variables': {
+    'msvs_use_common_release': 0,
+    'clang%': 0,
+    'asan%': 0,
+    'lsan%': 0,
+    'msan%': 0,
+    'tsan%': 0,
+    'ubsan%': 0,
+    'ubsan_vptr%': 0,
+    'v8_target_arch%': '<(target_arch)',
+    'v8_host_byteorder%': '<!(python -c "import sys; print sys.byteorder")',
+    # Native Client builds currently use the V8 ARM JIT and
+    # arm/simulator-arm.cc to defer the significant effort required
+    # for NaCl JIT support. The nacl_target_arch variable provides
+    # the 'true' target arch for places in this file that need it.
+    # TODO(bradchen): get rid of nacl_target_arch when someday
+    # NaCl V8 builds stop using the ARM simulator
+    'nacl_target_arch%': 'none',     # must be set externally
+
+    # Setting 'v8_can_use_vfp32dregs' to 'true' will cause V8 to use the VFP
+    # registers d16-d31 in the generated code, both in the snapshot and for the
+    # ARM target. Leaving the default value of 'false' will avoid the use of
+    # these registers in the snapshot and use CPU feature probing when running
+    # on the target.
+    'v8_can_use_vfp32dregs%': 'false',
+    'arm_test_noprobe%': 'off',
+
+    # Similar to vfp but on MIPS.
+    'v8_can_use_fpu_instructions%': 'true',
+
+    # Similar to the ARM hard float ABI but on MIPS.
+    'v8_use_mips_abi_hardfloat%': 'true',
+
+    # Force disable libstdc++ debug mode.
+    'disable_glibcxx_debug%': 0,
+
+    'v8_enable_backtrace%': 0,
+
+    # Enable profiling support. Only required on Windows.
+    'v8_enable_prof%': 0,
+
+    # Some versions of GCC 4.5 seem to need -fno-strict-aliasing.
+    'v8_no_strict_aliasing%': 0,
+
+    # Chrome needs this definition unconditionally. For standalone V8 builds,
+    # it's handled in gypfiles/standalone.gypi.
+    'want_separate_host_toolset%': 1,
+
+    # Toolset the shell binary should be compiled for. Possible values are
+    # 'host' and 'target'.
+    # The setting is ignored if want_separate_host_toolset is 0.
+    'v8_toolset_for_shell%': 'target',
+
+    'host_os%': '<(OS)',
+    'werror%': '-Werror',
+    # For a shared library build, results in "libv8-<(soname_version).so".
+    'soname_version%': '',
+
+    # Allow to suppress the array bounds warning (default is no suppression).
+    'wno_array_bounds%': '',
+
+    # Override where to find binutils
+    'binutils_dir%': '',
+
+    'conditions': [
+      ['OS=="linux" and host_arch=="x64"', {
+        'binutils_dir%': 'third_party/binutils/Linux_x64/Release/bin',
+      }],
+      ['OS=="linux" and host_arch=="ia32"', {
+        'binutils_dir%': 'third_party/binutils/Linux_ia32/Release/bin',
+      }],
+
+      # linux_use_bundled_gold: whether to use the gold linker binary checked
+      # into third_party/binutils.  Force this off via GYP_DEFINES when you
+      # are using a custom toolchain and need to control -B in ldflags.
+      # Do not use 32-bit gold on 32-bit hosts as it runs out address space
+      # for component=static_library builds.
+      ['OS=="linux" and (target_arch=="x64" or target_arch=="arm")', {
+        'linux_use_bundled_gold%': 1,
+      }, {
+        'linux_use_bundled_gold%': 0,
+      }],
+      # linux_use_bundled_binutils: whether to use the binary binutils
+      # checked into third_party/binutils.  These are not multi-arch so cannot
+      # be used except on x86 and x86-64 (the only two architectures which
+      # are currently checke in).  Force this off via GYP_DEFINES when you
+      # are using a custom toolchain and need to control -B in cflags.
+      ['OS=="linux" and (target_arch=="ia32" or target_arch=="x64")', {
+        'linux_use_bundled_binutils%': 1,
+      }, {
+        'linux_use_bundled_binutils%': 0,
+      }],
+      # linux_use_gold_flags: whether to use build flags that rely on gold.
+      # On by default for x64 Linux.
+      ['OS=="linux" and target_arch=="x64"', {
+        'linux_use_gold_flags%': 1,
+      }, {
+        'linux_use_gold_flags%': 0,
+      }],
+    ],
+
+    # Link-Time Optimizations
+    'use_lto%': 0,
+  },
+  'conditions': [
+    ['host_arch=="ia32" or host_arch=="x64" or \
+      host_arch=="ppc" or host_arch=="ppc64" or \
+      host_arch=="s390" or host_arch=="s390x" or \
+      clang==1', {
+      'variables': {
+        'host_cxx_is_biarch%': 1,
+       },
+     }, {
+      'variables': {
+        'host_cxx_is_biarch%': 0,
+      },
+    }],
+    ['target_arch=="ia32" or target_arch=="x64" or target_arch=="x87" or \
+      target_arch=="ppc" or target_arch=="ppc64" or target_arch=="s390" or \
+      target_arch=="s390x" or clang==1', {
+      'variables': {
+        'target_cxx_is_biarch%': 1,
+       },
+     }, {
+      'variables': {
+        'target_cxx_is_biarch%': 0,
+      },
+    }],
+  ],
+  'target_defaults': {
+    'conditions': [
+      ['v8_target_arch=="arm"', {
+        'defines': [
+          'V8_TARGET_ARCH_ARM',
+        ],
+        'conditions': [
+          [ 'arm_version==7 or arm_version=="default"', {
+            'defines': [
+              'CAN_USE_ARMV7_INSTRUCTIONS',
+            ],
+          }],
+          [ 'arm_fpu=="vfpv3-d16" or arm_fpu=="default"', {
+            'defines': [
+              'CAN_USE_VFP3_INSTRUCTIONS',
+            ],
+          }],
+          [ 'arm_fpu=="vfpv3"', {
+            'defines': [
+              'CAN_USE_VFP3_INSTRUCTIONS',
+              'CAN_USE_VFP32DREGS',
+            ],
+          }],
+          [ 'arm_fpu=="neon"', {
+            'defines': [
+              'CAN_USE_VFP3_INSTRUCTIONS',
+              'CAN_USE_VFP32DREGS',
+              'CAN_USE_NEON',
+            ],
+          }],
+          [ 'arm_test_noprobe=="on"', {
+            'defines': [
+              'ARM_TEST_NO_FEATURE_PROBE',
+            ],
+          }],
+        ],
+        'target_conditions': [
+          ['_toolset=="host"', {
+            'conditions': [
+              ['v8_target_arch==host_arch', {
+                # Host built with an Arm CXX compiler.
+                'conditions': [
+                  [ 'arm_version==7', {
+                    'cflags': ['-march=armv7-a',],
+                  }],
+                  [ 'arm_version==7 or arm_version=="default"', {
+                    'conditions': [
+                      [ 'arm_fpu!="default"', {
+                        'cflags': ['-mfpu=<(arm_fpu)',],
+                      }],
+                    ],
+                  }],
+                  [ 'arm_float_abi!="default"', {
+                    'cflags': ['-mfloat-abi=<(arm_float_abi)',],
+                  }],
+                  [ 'arm_thumb==1', {
+                    'cflags': ['-mthumb',],
+                  }],
+                  [ 'arm_thumb==0', {
+                    'cflags': ['-marm',],
+                  }],
+                ],
+              }, {
+                # 'v8_target_arch!=host_arch'
+                # Host not built with an Arm CXX compiler (simulator build).
+                'conditions': [
+                  [ 'arm_float_abi=="hard"', {
+                    'defines': [
+                      'USE_EABI_HARDFLOAT=1',
+                    ],
+                  }],
+                  [ 'arm_float_abi=="softfp" or arm_float_abi=="default"', {
+                    'defines': [
+                      'USE_EABI_HARDFLOAT=0',
+                    ],
+                  }],
+                ],
+              }],
+            ],
+          }],  # _toolset=="host"
+          ['_toolset=="target"', {
+            'conditions': [
+              ['v8_target_arch==target_arch', {
+                # Target built with an Arm CXX compiler.
+                'conditions': [
+                  [ 'arm_version==7', {
+                    'cflags': ['-march=armv7-a',],
+                  }],
+                  [ 'arm_version==7 or arm_version=="default"', {
+                    'conditions': [
+                      [ 'arm_fpu!="default"', {
+                        'cflags': ['-mfpu=<(arm_fpu)',],
+                      }],
+                    ],
+                  }],
+                  [ 'arm_float_abi!="default"', {
+                    'cflags': ['-mfloat-abi=<(arm_float_abi)',],
+                  }],
+                  [ 'arm_thumb==1', {
+                    'cflags': ['-mthumb',],
+                  }],
+                  [ 'arm_thumb==0', {
+                    'cflags': ['-marm',],
+                  }],
+                ],
+              }, {
+                # 'v8_target_arch!=target_arch'
+                # Target not built with an Arm CXX compiler (simulator build).
+                'conditions': [
+                  [ 'arm_float_abi=="hard"', {
+                    'defines': [
+                      'USE_EABI_HARDFLOAT=1',
+                    ],
+                  }],
+                  [ 'arm_float_abi=="softfp" or arm_float_abi=="default"', {
+                    'defines': [
+                      'USE_EABI_HARDFLOAT=0',
+                    ],
+                  }],
+                ],
+              }],
+              # Disable GCC LTO for v8
+              # v8 is optimized for speed. Because GCC LTO merges flags at link
+              # time, we disable LTO to prevent any -O2 flags from taking
+              # precedence over v8's -Os flag. However, LLVM LTO does not work
+              # this way so we keep LTO enabled under LLVM.
+              ['clang==0 and use_lto==1', {
+                'cflags!': [
+                  '-flto',
+                  '-ffat-lto-objects',
+                ],
+              }],
+            ],
+          }],  # _toolset=="target"
+        ],
+      }],  # v8_target_arch=="arm"
+      ['v8_target_arch=="arm64"', {
+        'defines': [
+          'V8_TARGET_ARCH_ARM64',
+        ],
+      }],
+      ['v8_target_arch=="s390" or v8_target_arch=="s390x"', {
+        'defines': [
+          'V8_TARGET_ARCH_S390',
+        ],
+        'conditions': [
+          ['v8_target_arch=="s390x"', {
+            'defines': [
+              'V8_TARGET_ARCH_S390X',
+            ],
+          }],
+          ['v8_host_byteorder=="little"', {
+            'defines': [
+              'V8_TARGET_ARCH_S390_LE_SIM',
+            ],
+          }],
+          ],
+      }],  # s390
+      ['v8_target_arch=="ppc" or v8_target_arch=="ppc64"', {
+        'defines': [
+          'V8_TARGET_ARCH_PPC',
+        ],
+        'conditions': [
+          ['v8_target_arch=="ppc64"', {
+            'defines': [
+              'V8_TARGET_ARCH_PPC64',
+            ],
+          }],
+          ['v8_host_byteorder=="little"', {
+            'defines': [
+              'V8_TARGET_ARCH_PPC_LE',
+            ],
+          }],
+          ['v8_host_byteorder=="big"', {
+            'defines': [
+              'V8_TARGET_ARCH_PPC_BE',
+            ],
+            'conditions': [
+              ['OS=="aix"', {
+                # Work around AIX ceil, trunc and round oddities.
+                'cflags': [ '-mcpu=power5+ -mfprnd' ],
+              }],
+              ['OS=="aix"', {
+                # Work around AIX assembler popcntb bug.
+                'cflags': [ '-mno-popcntb' ],
+              }],
+            ],
+          }],
+        ],
+      }],  # ppc
+      ['v8_target_arch=="ia32"', {
+        'defines': [
+          'V8_TARGET_ARCH_IA32',
+        ],
+      }],  # v8_target_arch=="ia32"
+      ['v8_target_arch=="x87"', {
+        'defines': [
+          'V8_TARGET_ARCH_X87',
+        ],
+        'cflags': ['-march=i586'],
+      }],  # v8_target_arch=="x87"
+      ['(v8_target_arch=="mips" or v8_target_arch=="mipsel" \
+        or v8_target_arch=="mips64" or v8_target_arch=="mips64el") \
+         and v8_target_arch==target_arch', {
+        'target_conditions': [
+          ['_toolset=="target"', {
+            # Target built with a Mips CXX compiler.
+            'variables': {
+              'ldso_path%': '<!(/bin/echo -n $LDSO_PATH)',
+              'ld_r_path%': '<!(/bin/echo -n $LD_R_PATH)',
+            },
+            'conditions': [
+              ['ldso_path!=""', {
+                'ldflags': ['-Wl,--dynamic-linker=<(ldso_path)'],
+              }],
+              ['ld_r_path!=""', {
+                'ldflags': ['-Wl,--rpath=<(ld_r_path)'],
+              }],
+              [ 'clang==1', {
+                'cflags': ['-integrated-as'],
+              }],
+            ],
+          }],
+        ],
+      }],
+      ['v8_target_arch=="mips"', {
+        'defines': [
+          'V8_TARGET_ARCH_MIPS',
+        ],
+        'conditions': [
+          [ 'v8_can_use_fpu_instructions=="true"', {
+            'defines': [
+              'CAN_USE_FPU_INSTRUCTIONS',
+            ],
+          }],
+          [ 'v8_use_mips_abi_hardfloat=="true"', {
+            'defines': [
+              '__mips_hard_float=1',
+              'CAN_USE_FPU_INSTRUCTIONS',
+            ],
+          }, {
+            'defines': [
+              '__mips_soft_float=1'
+            ]
+          }],
+        ],
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'conditions': [
+              ['v8_target_arch==target_arch', {
+                # Target built with a Mips CXX compiler.
+                'cflags': [
+                  '-EB',
+                  '-Wno-error=array-bounds',  # Workaround https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273
+                ],
+                'ldflags': ['-EB'],
+                'conditions': [
+                  [ 'v8_use_mips_abi_hardfloat=="true"', {
+                    'cflags': ['-mhard-float'],
+                    'ldflags': ['-mhard-float'],
+                  }, {
+                    'cflags': ['-msoft-float'],
+                    'ldflags': ['-msoft-float'],
+                  }],
+                  ['mips_arch_variant=="r6"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32R6',
+                      'FPU_MODE_FP64',
+                    ],
+                    'cflags!': ['-mfp32', '-mfpxx'],
+                    'conditions': [
+                      [ 'clang==0', {
+                        'cflags': ['-Wa,-mips32r6'],
+                      }],
+                    ],
+                    'cflags': ['-mips32r6'],
+                    'ldflags': ['-mips32r6'],
+                  }],
+                  ['mips_arch_variant=="r2"', {
+                    'conditions': [
+                      [ 'mips_fpu_mode=="fp64"', {
+                        'defines': [
+                          '_MIPS_ARCH_MIPS32R2',
+                          'FPU_MODE_FP64',
+                        ],
+                        'cflags': ['-mfp64'],
+                      }],
+                      ['mips_fpu_mode=="fpxx"', {
+                        'defines': [
+                          '_MIPS_ARCH_MIPS32R2',
+                          'FPU_MODE_FPXX',
+                        ],
+                        'cflags': ['-mfpxx'],
+                      }],
+                      ['mips_fpu_mode=="fp32"', {
+                        'defines': [
+                          '_MIPS_ARCH_MIPS32R2',
+                          'FPU_MODE_FP32',
+                        ],
+                        'cflags': ['-mfp32'],
+                      }],
+                      [ 'clang==0', {
+                        'cflags': ['-Wa,-mips32r2'],
+                      }],
+                    ],
+                    'cflags': ['-mips32r2'],
+                    'ldflags': ['-mips32r2'],
+                  }],
+                  ['mips_arch_variant=="r1"', {
+                    'defines': [
+                      'FPU_MODE_FP32',
+                    ],
+                    'cflags!': ['-mfp64', '-mfpxx'],
+                    'conditions': [
+                      [ 'clang==0', {
+                        'cflags': ['-Wa,-mips32'],
+                      }],
+                    ],
+                    'cflags': ['-mips32'],
+                    'ldflags': ['-mips32'],
+                  }],
+                  ['mips_arch_variant=="rx"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32RX',
+                      'FPU_MODE_FPXX',
+                    ],
+                    'cflags!': ['-mfp64', '-mfp32'],
+                    'conditions': [
+                      [ 'clang==0', {
+                        'cflags': ['-Wa,-mips32'],
+                      }],
+                    ],
+                    'cflags': ['-mips32', '-mfpxx'],
+                    'ldflags': ['-mips32'],
+                  }],
+                ],
+              }, {
+                # 'v8_target_arch!=target_arch'
+                # Target not built with an MIPS CXX compiler (simulator build).
+                'conditions': [
+                  ['mips_arch_variant=="r6"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32R6',
+                      'FPU_MODE_FP64',
+                    ],
+                  }],
+                  ['mips_arch_variant=="r2"', {
+                    'conditions': [
+                      [ 'mips_fpu_mode=="fp64"', {
+                        'defines': [
+                          '_MIPS_ARCH_MIPS32R2',
+                          'FPU_MODE_FP64',
+                        ],
+                      }],
+                      ['mips_fpu_mode=="fpxx"', {
+                        'defines': [
+                          '_MIPS_ARCH_MIPS32R2',
+                          'FPU_MODE_FPXX',
+                        ],
+                      }],
+                      ['mips_fpu_mode=="fp32"', {
+                        'defines': [
+                          '_MIPS_ARCH_MIPS32R2',
+                          'FPU_MODE_FP32',
+                        ],
+                      }],
+                    ],
+                  }],
+                  ['mips_arch_variant=="r1"', {
+                    'defines': [
+                      'FPU_MODE_FP32',
+                    ],
+                  }],
+                  ['mips_arch_variant=="rx"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32RX',
+                      'FPU_MODE_FPXX',
+                    ],
+                  }],
+                ],
+              }],
+            ],
+          }],  #_toolset=="target"
+          ['_toolset=="host"', {
+            'conditions': [
+              ['mips_arch_variant=="rx"', {
+                'defines': [
+                  '_MIPS_ARCH_MIPS32RX',
+                  'FPU_MODE_FPXX',
+                ],
+              }],
+              ['mips_arch_variant=="r6"', {
+                'defines': [
+                  '_MIPS_ARCH_MIPS32R6',
+                  'FPU_MODE_FP64',
+                ],
+              }],
+              ['mips_arch_variant=="r2"', {
+                'conditions': [
+                  ['mips_fpu_mode=="fp64"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32R2',
+                      'FPU_MODE_FP64',
+                    ],
+                  }],
+                  ['mips_fpu_mode=="fpxx"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32R2',
+                      'FPU_MODE_FPXX',
+                    ],
+                  }],
+                  ['mips_fpu_mode=="fp32"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32R2',
+                      'FPU_MODE_FP32'
+                    ],
+                  }],
+                ],
+              }],
+              ['mips_arch_variant=="r1"', {
+                'defines': ['FPU_MODE_FP32',],
+              }],
+            ]
+          }],  #_toolset=="host"
+        ],
+      }],  # v8_target_arch=="mips"
+      ['v8_target_arch=="mipsel"', {
+        'defines': [
+          'V8_TARGET_ARCH_MIPS',
+        ],
+        'conditions': [
+          [ 'v8_can_use_fpu_instructions=="true"', {
+            'defines': [
+              'CAN_USE_FPU_INSTRUCTIONS',
+            ],
+          }],
+          [ 'v8_use_mips_abi_hardfloat=="true"', {
+            'defines': [
+              '__mips_hard_float=1',
+              'CAN_USE_FPU_INSTRUCTIONS',
+            ],
+          }, {
+            'defines': [
+              '__mips_soft_float=1'
+            ],
+          }],
+        ],
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'conditions': [
+              ['v8_target_arch==target_arch', {
+                # Target built with a Mips CXX compiler.
+                'cflags': [
+                  '-EL',
+                  '-Wno-error=array-bounds',  # Workaround https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273
+                ],
+                'ldflags': ['-EL'],
+                'conditions': [
+                  [ 'v8_use_mips_abi_hardfloat=="true"', {
+                    'cflags': ['-mhard-float'],
+                    'ldflags': ['-mhard-float'],
+                  }, {
+                    'cflags': ['-msoft-float'],
+                    'ldflags': ['-msoft-float'],
+                  }],
+                  ['mips_arch_variant=="r6"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32R6',
+                      'FPU_MODE_FP64',
+                    ],
+                    'cflags!': ['-mfp32', '-mfpxx'],
+                    'conditions': [
+                      [ 'clang==0', {
+                        'cflags': ['-Wa,-mips32r6'],
+                      }],
+                    ],
+                    'cflags': ['-mips32r6'],
+                    'ldflags': ['-mips32r6'],
+                  }],
+                  ['mips_arch_variant=="r2"', {
+                    'conditions': [
+                      [ 'mips_fpu_mode=="fp64"', {
+                        'defines': [
+                          '_MIPS_ARCH_MIPS32R2',
+                          'FPU_MODE_FP64',
+                        ],
+                        'cflags': ['-mfp64'],
+                      }],
+                      ['mips_fpu_mode=="fpxx"', {
+                        'defines': [
+                          '_MIPS_ARCH_MIPS32R2',
+                          'FPU_MODE_FPXX',
+                        ],
+                        'cflags': ['-mfpxx'],
+                      }],
+                      ['mips_fpu_mode=="fp32"', {
+                        'defines': [
+                          '_MIPS_ARCH_MIPS32R2',
+                          'FPU_MODE_FP32',
+                        ],
+                        'cflags': ['-mfp32'],
+                      }],
+                      [ 'clang==0', {
+                        'cflags': ['-Wa,-mips32r2'],
+                      }],
+                    ],
+                    'cflags': ['-mips32r2'],
+                    'ldflags': ['-mips32r2'],
+                  }],
+                  ['mips_arch_variant=="r1"', {
+                    'defines': [
+                      'FPU_MODE_FP32',
+                    ],
+                    'cflags!': ['-mfp64', '-mfpxx'],
+                    'conditions': [
+                      [ 'clang==0', {
+                        'cflags': ['-Wa,-mips32'],
+                      }],
+                    ],
+                    'cflags': ['-mips32'],
+                    'ldflags': ['-mips32'],
+                  }],
+                  ['mips_arch_variant=="rx"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32RX',
+                      'FPU_MODE_FPXX',
+                    ],
+                    'cflags!': ['-mfp64', '-mfp32'],
+                    'conditions': [
+                      [ 'clang==0', {
+                        'cflags': ['-Wa,-mips32'],
+                      }],
+                    ],
+                    'cflags': ['-mips32', '-mfpxx'],
+                    'ldflags': ['-mips32'],
+                  }],
+                  ['mips_arch_variant=="loongson"', {
+                    'defines': [
+                      '_MIPS_ARCH_LOONGSON',
+                      'FPU_MODE_FP32',
+                    ],
+                    'cflags!': ['-mfp64', '-mfpxx'],
+                    'conditions': [
+                      [ 'clang==0', {
+                        'cflags': ['-Wa,-mips3'],
+                      }],
+                    ],
+                    'cflags': ['-mips3', '-mfp32'],
+                  }],
+                ],
+              }, {
+                # 'v8_target_arch!=target_arch'
+                # Target not built with an MIPS CXX compiler (simulator build).
+                'conditions': [
+                  ['mips_arch_variant=="r6"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32R6',
+                      'FPU_MODE_FP64',
+                    ],
+                  }],
+                  ['mips_arch_variant=="r2"', {
+                    'conditions': [
+                      [ 'mips_fpu_mode=="fp64"', {
+                        'defines': [
+                          '_MIPS_ARCH_MIPS32R2',
+                          'FPU_MODE_FP64',
+                        ],
+                      }],
+                      ['mips_fpu_mode=="fpxx"', {
+                        'defines': [
+                          '_MIPS_ARCH_MIPS32R2',
+                          'FPU_MODE_FPXX',
+                        ],
+                      }],
+                      ['mips_fpu_mode=="fp32"', {
+                        'defines': [
+                          '_MIPS_ARCH_MIPS32R2',
+                          'FPU_MODE_FP32',
+                        ],
+                      }],
+                    ],
+                  }],
+                  ['mips_arch_variant=="r1"', {
+                    'defines': [
+                      'FPU_MODE_FP32',
+                    ],
+                  }],
+                  ['mips_arch_variant=="rx"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32RX',
+                      'FPU_MODE_FPXX',
+                    ],
+                  }],
+                  ['mips_arch_variant=="loongson"', {
+                    'defines': [
+                      '_MIPS_ARCH_LOONGSON',
+                      'FPU_MODE_FP32',
+                    ],
+                  }],
+                ],
+              }],
+            ],
+          }], #_toolset=="target
+          ['_toolset=="host"', {
+            'conditions': [
+              ['mips_arch_variant=="rx"', {
+                'defines': [
+                  '_MIPS_ARCH_MIPS32RX',
+                  'FPU_MODE_FPXX',
+                ],
+              }],
+              ['mips_arch_variant=="r6"', {
+                'defines': [
+                  '_MIPS_ARCH_MIPS32R6',
+                  'FPU_MODE_FP64',
+                ],
+              }],
+              ['mips_arch_variant=="r2"', {
+                'conditions': [
+                  ['mips_fpu_mode=="fp64"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32R2',
+                      'FPU_MODE_FP64',
+                    ],
+                  }],
+                  ['mips_fpu_mode=="fpxx"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32R2',
+                      'FPU_MODE_FPXX',
+                    ],
+                  }],
+                  ['mips_fpu_mode=="fp32"', {
+                    'defines': [
+                      '_MIPS_ARCH_MIPS32R2',
+                      'FPU_MODE_FP32'
+                    ],
+                  }],
+                ],
+              }],
+              ['mips_arch_variant=="r1"', {
+                'defines': ['FPU_MODE_FP32',],
+              }],
+              ['mips_arch_variant=="loongson"', {
+                'defines': [
+                  '_MIPS_ARCH_LOONGSON',
+                  'FPU_MODE_FP32',
+                ],
+              }],
+            ]
+          }],
+        ],
+      }],  # v8_target_arch=="mipsel"
+      ['v8_target_arch=="mips64el" or v8_target_arch=="mips64"', {
+        'defines': [
+          'V8_TARGET_ARCH_MIPS64',
+        ],
+        'conditions': [
+          [ 'v8_can_use_fpu_instructions=="true"', {
+            'defines': [
+              'CAN_USE_FPU_INSTRUCTIONS',
+            ],
+          }],
+          [ 'v8_host_byteorder=="little"', {
+            'defines': [
+              'V8_TARGET_ARCH_MIPS64_LE',
+            ],
+          }],
+          [ 'v8_host_byteorder=="big"', {
+            'defines': [
+              'V8_TARGET_ARCH_MIPS64_BE',
+            ],
+          }],
+          [ 'v8_use_mips_abi_hardfloat=="true"', {
+            'defines': [
+              '__mips_hard_float=1',
+              'CAN_USE_FPU_INSTRUCTIONS',
+            ],
+          }, {
+            'defines': [
+              '__mips_soft_float=1'
+            ],
+          }],
+         ],
+        'target_conditions': [
+          ['_toolset=="target"', {
+            'conditions': [
+              ['v8_target_arch==target_arch', {
+                'cflags': [
+                  '-Wno-error=array-bounds',  # Workaround https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273
+                ],
+                'conditions': [
+                  ['v8_target_arch=="mips64el"', {
+                    'cflags': ['-EL'],
+                    'ldflags': ['-EL'],
+                  }],
+                  ['v8_target_arch=="mips64"', {
+                    'cflags': ['-EB'],
+                    'ldflags': ['-EB'],
+                  }],
+                  [ 'v8_use_mips_abi_hardfloat=="true"', {
+                    'cflags': ['-mhard-float'],
+                    'ldflags': ['-mhard-float'],
+                  }, {
+                    'cflags': ['-msoft-float'],
+                    'ldflags': ['-msoft-float'],
+                  }],
+                  ['mips_arch_variant=="r6"', {
+                    'defines': ['_MIPS_ARCH_MIPS64R6',],
+                    'conditions': [
+                      [ 'clang==0', {
+                        'cflags': ['-Wa,-mips64r6'],
+                      }],
+                    ],
+                    'cflags': ['-mips64r6', '-mabi=64'],
+                    'ldflags': ['-mips64r6', '-mabi=64'],
+                  }],
+                  ['mips_arch_variant=="r2"', {
+                    'defines': ['_MIPS_ARCH_MIPS64R2',],
+                    'conditions': [
+                      [ 'clang==0', {
+                        'cflags': ['-Wa,-mips64r2'],
+                      }],
+                    ],
+                    'cflags': ['-mips64r2', '-mabi=64'],
+                    'ldflags': ['-mips64r2', '-mabi=64'],
+                  }],
+                ],
+              }, {
+                # 'v8_target_arch!=target_arch'
+                # Target not built with an MIPS CXX compiler (simulator build).
+                'conditions': [
+                  ['mips_arch_variant=="r6"', {
+                    'defines': ['_MIPS_ARCH_MIPS64R6',],
+                  }],
+                  ['mips_arch_variant=="r2"', {
+                    'defines': ['_MIPS_ARCH_MIPS64R2',],
+                  }],
+                ],
+              }],
+            ],
+          }],  #'_toolset=="target"
+          ['_toolset=="host"', {
+            'conditions': [
+              ['mips_arch_variant=="r6"', {
+                'defines': ['_MIPS_ARCH_MIPS64R6',],
+              }],
+              ['mips_arch_variant=="r2"', {
+                'defines': ['_MIPS_ARCH_MIPS64R2',],
+              }],
+            ],
+          }],  #'_toolset=="host"
+        ],
+      }],  # v8_target_arch=="mips64el"
+      ['v8_target_arch=="x64"', {
+        'defines': [
+          'V8_TARGET_ARCH_X64',
+        ],
+        'xcode_settings': {
+          'ARCHS': [ 'x86_64' ],
+        },
+        'msvs_settings': {
+          'VCLinkerTool': {
+            'StackReserveSize': '2097152',
+          },
+        },
+        'msvs_configuration_platform': 'x64',
+      }],  # v8_target_arch=="x64"
+      ['v8_target_arch=="x32"', {
+        'defines': [
+          # x32 port shares the source code with x64 port.
+          'V8_TARGET_ARCH_X64',
+          'V8_TARGET_ARCH_32_BIT',
+        ],
+        'cflags': [
+          '-mx32',
+          # Inhibit warning if long long type is used.
+          '-Wno-long-long',
+        ],
+        'ldflags': [
+          '-mx32',
+        ],
+      }],  # v8_target_arch=="x32"
+      ['linux_use_gold_flags==1', {
+        # Newer gccs and clangs support -fuse-ld, use the flag to force gold
+        # selection.
+        # gcc -- http://gcc.gnu.org/onlinedocs/gcc-4.8.0/gcc/Optimize-Options.html
+        'ldflags': [ '-fuse-ld=gold', ],
+      }],
+      ['linux_use_bundled_binutils==1', {
+        'cflags': [
+          '-B<!(cd <(DEPTH) && pwd -P)/<(binutils_dir)',
+        ],
+      }],
+      ['linux_use_bundled_gold==1', {
+        # Put our binutils, which contains gold in the search path. We pass
+        # the path to gold to the compiler. gyp leaves unspecified what the
+        # cwd is when running the compiler, so the normal gyp path-munging
+        # fails us. This hack gets the right path.
+        'ldflags': [
+          '-B<!(cd <(DEPTH) && pwd -P)/<(binutils_dir)',
+        ],
+      }],
+      ['OS=="win"', {
+        'defines': [
+          'WIN32',
+        ],
+        # 4351: VS 2005 and later are warning us that they've fixed a bug
+        #       present in VS 2003 and earlier.
+        'msvs_disabled_warnings': [4351],
+        'msvs_configuration_attributes': {
+          'OutputDirectory': '<(DEPTH)\\build\\$(ConfigurationName)',
+          'IntermediateDirectory': '$(OutDir)\\obj\\$(ProjectName)',
+          'CharacterSet': '1',
+        },
+      }],
+      ['OS=="win" and v8_target_arch=="ia32"', {
+        'msvs_settings': {
+          'VCCLCompilerTool': {
+            # Ensure no surprising artifacts from 80bit double math with x86.
+            'AdditionalOptions': ['/arch:SSE2'],
+          },
+        },
+      }],
+      ['OS=="win" and v8_enable_prof==1', {
+        'msvs_settings': {
+          'VCLinkerTool': {
+            'GenerateMapFile': 'true',
+          },
+        },
+      }],
+      ['(OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris" \
+         or OS=="netbsd" or OS=="mac" or OS=="android" or OS=="qnx") and \
+        v8_target_arch=="ia32"', {
+        'cflags': [
+          '-msse2',
+          '-mfpmath=sse',
+          '-mmmx',  # Allows mmintrin.h for MMX intrinsics.
+        ],
+      }],
+      ['(OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris" \
+         or OS=="netbsd" or OS=="mac" or OS=="android" or OS=="qnx") and \
+        (v8_target_arch=="arm" or v8_target_arch=="ia32" or \
+         v8_target_arch=="x87" or v8_target_arch=="mips" or \
+         v8_target_arch=="mipsel" or v8_target_arch=="ppc" or \
+         v8_target_arch=="s390")', {
+        'target_conditions': [
+          ['_toolset=="host"', {
+            'conditions': [
+              ['host_cxx_is_biarch==1', {
+                'conditions': [
+                  ['host_arch=="s390" or host_arch=="s390x"', {
+                    'cflags': [ '-m31' ],
+                    'ldflags': [ '-m31' ]
+                  },{
+                   'cflags': [ '-m32' ],
+                   'ldflags': [ '-m32' ]
+                  }],
+                ],
+              }],
+            ],
+            'xcode_settings': {
+              'ARCHS': [ 'i386' ],
+            },
+          }],
+          ['_toolset=="target"', {
+            'conditions': [
+              ['target_cxx_is_biarch==1 and nacl_target_arch!="nacl_x64"', {
+                'conditions': [
+                  ['host_arch=="s390" or host_arch=="s390x"', {
+                    'cflags': [ '-m31' ],
+                    'ldflags': [ '-m31' ]
+                  },{
+                   'cflags': [ '-m32' ],
+                   'ldflags': [ '-m32' ],
+                  }],
+                ],
+              }],
+            ],
+            'xcode_settings': {
+              'ARCHS': [ 'i386' ],
+            },
+          }],
+        ],
+      }],
+      ['(OS=="linux" or OS=="android") and \
+        (v8_target_arch=="x64" or v8_target_arch=="arm64" or \
+         v8_target_arch=="ppc64" or v8_target_arch=="s390x")', {
+        'target_conditions': [
+          ['_toolset=="host"', {
+            'conditions': [
+              ['host_cxx_is_biarch==1', {
+                'cflags': [ '-m64' ],
+                'ldflags': [ '-m64' ]
+              }],
+             ],
+           }],
+           ['_toolset=="target"', {
+             'conditions': [
+               ['target_cxx_is_biarch==1', {
+                 'cflags': [ '-m64' ],
+                 'ldflags': [ '-m64' ],
+               }],
+             ]
+           }],
+         ],
+      }],
+      ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris" \
+         or OS=="netbsd" or OS=="qnx" or OS=="aix"', {
+        'conditions': [
+          [ 'v8_no_strict_aliasing==1', {
+            'cflags': [ '-fno-strict-aliasing' ],
+          }],
+        ],  # conditions
+      }],
+      ['OS=="solaris"', {
+        'defines': [ '__C99FEATURES__=1' ],  # isinf() etc.
+      }],
+      ['OS=="freebsd" or OS=="openbsd"', {
+        'cflags': [ '-I/usr/local/include' ],
+      }],
+      ['OS=="netbsd"', {
+        'cflags': [ '-I/usr/pkg/include' ],
+      }],
+      ['OS=="aix"', {
+        'defines': [
+          # Support for malloc(0)
+          '_LINUX_SOURCE_COMPAT=1',
+          '_ALL_SOURCE=1'],
+        'conditions': [
+          [ 'v8_target_arch=="ppc"', {
+            'ldflags': [ '-Wl,-bmaxdata:0x60000000/dsa' ],
+          }],
+          [ 'v8_target_arch=="ppc64"', {
+            'cflags': [ '-maix64' ],
+            'ldflags': [ '-maix64' ],
+          }],
+        ],
+      }],
+    ],  # conditions
+    'configurations': {
+      # Abstract configuration for v8_optimized_debug == 0.
+      'DebugBase0': {
+        'abstract': 1,
+        'msvs_settings': {
+          'VCCLCompilerTool': {
+            'Optimization': '0',
+            'conditions': [
+              ['component=="shared_library"', {
+                'RuntimeLibrary': '3',  # /MDd
+              }, {
+                'RuntimeLibrary': '1',  # /MTd
+              }],
+            ],
+          },
+          'VCLinkerTool': {
+            'LinkIncremental': '2',
+          },
+        },
+        'variables': {
+          'v8_enable_slow_dchecks%': 1,
+        },
+        'conditions': [
+          ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="netbsd" or \
+            OS=="qnx" or OS=="aix"', {
+            'cflags!': [
+              '-O3',
+              '-O2',
+              '-O1',
+              '-Os',
+            ],
+            'cflags': [
+              '-fdata-sections',
+              '-ffunction-sections',
+            ],
+          }],
+          ['OS=="mac"', {
+            'xcode_settings': {
+               'GCC_OPTIMIZATION_LEVEL': '0',  # -O0
+            },
+          }],
+          ['v8_enable_slow_dchecks==1', {
+            'defines': [
+              'ENABLE_SLOW_DCHECKS',
+            ],
+          }],
+        ],
+      },  # DebugBase0
+      # Abstract configuration for v8_optimized_debug == 1.
+      'DebugBase1': {
+        'abstract': 1,
+        'msvs_settings': {
+          'VCCLCompilerTool': {
+            'Optimization': '2',
+            'InlineFunctionExpansion': '2',
+            'EnableIntrinsicFunctions': 'true',
+            'FavorSizeOrSpeed': '0',
+            'StringPooling': 'true',
+            'BasicRuntimeChecks': '0',
+            'conditions': [
+              ['component=="shared_library"', {
+                'RuntimeLibrary': '3',  #/MDd
+              }, {
+                'RuntimeLibrary': '1',  #/MTd
+              }],
+            ],
+          },
+          'VCLinkerTool': {
+            'LinkIncremental': '1',
+            'OptimizeReferences': '2',
+            'EnableCOMDATFolding': '2',
+          },
+        },
+        'variables': {
+          'v8_enable_slow_dchecks%': 0,
+        },
+        'conditions': [
+          ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="netbsd" or \
+            OS=="qnx" or OS=="aix"', {
+            'cflags!': [
+              '-O0',
+              '-O1',
+              '-Os',
+            ],
+            'cflags': [
+              '-fdata-sections',
+              '-ffunction-sections',
+            ],
+            'conditions': [
+              # TODO(crbug.com/272548): Avoid -O3 in NaCl
+              # Don't use -O3 with sanitizers.
+              ['nacl_target_arch=="none" and asan==0 and msan==0 and lsan==0 \
+                and tsan==0 and ubsan==0 and ubsan_vptr==0', {
+                'cflags': ['-O3'],
+                'cflags!': ['-O2'],
+                }, {
+                'cflags': ['-O2'],
+                'cflags!': ['-O3'],
+              }],
+            ],
+          }],
+          ['OS=="mac"', {
+            'xcode_settings': {
+              'GCC_OPTIMIZATION_LEVEL': '3',  # -O3
+              'GCC_STRICT_ALIASING': 'YES',
+            },
+          }],
+          ['v8_enable_slow_dchecks==1', {
+            'defines': [
+              'ENABLE_SLOW_DCHECKS',
+            ],
+          }],
+        ],
+      },  # DebugBase1
+      # Common settings for the Debug configuration.
+      'DebugBaseCommon': {
+        'abstract': 1,
+        'defines': [
+          'ENABLE_DISASSEMBLER',
+          'V8_ENABLE_CHECKS',
+          'OBJECT_PRINT',
+          'VERIFY_HEAP',
+          'DEBUG',
+          'TRACE_MAPS'
+        ],
+        'conditions': [
+          ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="netbsd" or \
+            OS=="qnx" or OS=="aix"', {
+            'cflags': [ '-Woverloaded-virtual', '<(wno_array_bounds)', ],
+          }],
+          ['OS=="linux" and v8_enable_backtrace==1', {
+            # Support for backtrace_symbols.
+            'ldflags': [ '-rdynamic' ],
+          }],
+          ['OS=="linux" and disable_glibcxx_debug==0', {
+            # Enable libstdc++ debugging facilities to help catch problems
+            # early, see http://crbug.com/65151 .
+            'defines': ['_GLIBCXX_DEBUG=1',],
+          }],
+          ['OS=="aix"', {
+            'ldflags': [ '-Wl,-bbigtoc' ],
+            'conditions': [
+              ['v8_target_arch=="ppc64"', {
+                'cflags': [ '-maix64 -mcmodel=large' ],
+              }],
+            ],
+          }],
+          ['OS=="android"', {
+            'variables': {
+              'android_full_debug%': 1,
+            },
+            'conditions': [
+              ['android_full_debug==0', {
+                # Disable full debug if we want a faster v8 in a debug build.
+                # TODO(2304): pass DISABLE_DEBUG_ASSERT instead of hiding DEBUG.
+                'defines!': [
+                  'DEBUG',
+                  'ENABLE_SLOW_DCHECKS',
+                ],
+              }],
+            ],
+          }],
+          # TODO(pcc): Re-enable in LTO builds once we've fixed the intermittent
+          # link failures (crbug.com/513074).
+          ['linux_use_gold_flags==1 and use_lto==0', {
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'ldflags': [
+                  # Experimentation found that using four linking threads
+                  # saved ~20% of link time.
+                  # https://groups.google.com/a/chromium.org/group/chromium-dev/browse_thread/thread/281527606915bb36
+                  # Only apply this to the target linker, since the host
+                  # linker might not be gold, but isn't used much anyway.
+                  '-Wl,--threads',
+                  '-Wl,--thread-count=4',
+                ],
+              }],
+            ],
+          }],
+        ],
+      },  # DebugBaseCommon
+      'Debug': {
+        'inherit_from': ['DebugBaseCommon'],
+        'conditions': [
+          ['v8_optimized_debug==0', {
+            'inherit_from': ['DebugBase0'],
+          }, {
+            'inherit_from': ['DebugBase1'],
+          }],
+        ],
+      },  # Debug
+      'ReleaseBase': {
+        'abstract': 1,
+        'variables': {
+          'v8_enable_slow_dchecks%': 0,
+        },
+        'conditions': [
+          ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="netbsd" \
+            or OS=="aix"', {
+            'cflags!': [
+              '-Os',
+            ],
+            'cflags': [
+              '-fdata-sections',
+              '-ffunction-sections',
+              '<(wno_array_bounds)',
+            ],
+            'conditions': [
+              # TODO(crbug.com/272548): Avoid -O3 in NaCl
+              # Don't use -O3 with sanitizers.
+              ['nacl_target_arch=="none" and asan==0 and msan==0 and lsan==0 \
+                and tsan==0 and ubsan==0 and ubsan_vptr==0', {
+                'cflags': ['-O3'],
+                'cflags!': ['-O2'],
+              }, {
+                'cflags': ['-O2'],
+                'cflags!': ['-O3'],
+              }],
+            ],
+          }],
+          ['OS=="android"', {
+            'cflags!': [
+              '-O3',
+              '-Os',
+            ],
+            'cflags': [
+              '-fdata-sections',
+              '-ffunction-sections',
+              '-O2',
+            ],
+          }],
+          ['OS=="mac"', {
+            'xcode_settings': {
+              'GCC_OPTIMIZATION_LEVEL': '3',  # -O3
+
+              # -fstrict-aliasing.  Mainline gcc
+              # enables this at -O2 and above,
+              # but Apple gcc does not unless it
+              # is specified explicitly.
+              'GCC_STRICT_ALIASING': 'YES',
+            },
+          }],  # OS=="mac"
+          ['OS=="win"', {
+            'msvs_settings': {
+              'VCCLCompilerTool': {
+                'Optimization': '2',
+                'InlineFunctionExpansion': '2',
+                'EnableIntrinsicFunctions': 'true',
+                'FavorSizeOrSpeed': '0',
+                'StringPooling': 'true',
+                'conditions': [
+                  ['component=="shared_library"', {
+                    'RuntimeLibrary': '2',  #/MD
+                  }, {
+                    'RuntimeLibrary': '0',  #/MT
+                  }],
+                ],
+              },
+              'VCLinkerTool': {
+                'LinkIncremental': '1',
+                'OptimizeReferences': '2',
+                'EnableCOMDATFolding': '2',
+              },
+            },
+          }],  # OS=="win"
+          ['v8_enable_slow_dchecks==1', {
+            'defines': [
+              'ENABLE_SLOW_DCHECKS',
+            ],
+          }],
+        ],  # conditions
+      },  # Release
+      'Release': {
+        'inherit_from': ['ReleaseBase'],
+      },  # Debug
+      'conditions': [
+        [ 'OS=="win"', {
+          # TODO(bradnelson): add a gyp mechanism to make this more graceful.
+          'Debug_x64': {
+            'inherit_from': ['DebugBaseCommon'],
+            'conditions': [
+              ['v8_optimized_debug==0', {
+                'inherit_from': ['DebugBase0'],
+              }, {
+                'inherit_from': ['DebugBase1'],
+              }],
+            ],
+          },
+          'Release_x64': {
+            'inherit_from': ['ReleaseBase'],
+          },
+        }],
+      ],
+    },  # configurations
+  },  # target_defaults
+}
diff --git a/gypfiles/vs_toolchain.py b/gypfiles/vs_toolchain.py
new file mode 100644
index 0000000..1693647
--- /dev/null
+++ b/gypfiles/vs_toolchain.py
@@ -0,0 +1,379 @@
+#!/usr/bin/env python
+# Copyright 2015 the V8 project authors. All rights reserved.
+# Copyright 2014 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.
+
+import glob
+import json
+import os
+import pipes
+import shutil
+import subprocess
+import sys
+
+
+script_dir = os.path.dirname(os.path.realpath(__file__))
+chrome_src = os.path.abspath(os.path.join(script_dir, os.pardir))
+SRC_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(1, os.path.join(chrome_src, 'tools'))
+sys.path.insert(0, os.path.join(chrome_src, 'tools', 'gyp', 'pylib'))
+json_data_file = os.path.join(script_dir, 'win_toolchain.json')
+
+
+import gyp
+
+
+# Use MSVS2013 as the default toolchain.
+CURRENT_DEFAULT_TOOLCHAIN_VERSION = '2013'
+
+
+def SetEnvironmentAndGetRuntimeDllDirs():
+  """Sets up os.environ to use the depot_tools VS toolchain with gyp, and
+  returns the location of the VS runtime DLLs so they can be copied into
+  the output directory after gyp generation.
+  """
+  vs_runtime_dll_dirs = None
+  depot_tools_win_toolchain = \
+      bool(int(os.environ.get('DEPOT_TOOLS_WIN_TOOLCHAIN', '1')))
+  # When running on a non-Windows host, only do this if the SDK has explicitly
+  # been downloaded before (in which case json_data_file will exist).
+  if ((sys.platform in ('win32', 'cygwin') or os.path.exists(json_data_file))
+      and depot_tools_win_toolchain):
+    if ShouldUpdateToolchain():
+      Update()
+    with open(json_data_file, 'r') as tempf:
+      toolchain_data = json.load(tempf)
+
+    toolchain = toolchain_data['path']
+    version = toolchain_data['version']
+    win_sdk = toolchain_data.get('win_sdk')
+    if not win_sdk:
+      win_sdk = toolchain_data['win8sdk']
+    wdk = toolchain_data['wdk']
+    # TODO(scottmg): The order unfortunately matters in these. They should be
+    # split into separate keys for x86 and x64. (See CopyVsRuntimeDlls call
+    # below). http://crbug.com/345992
+    vs_runtime_dll_dirs = toolchain_data['runtime_dirs']
+
+    os.environ['GYP_MSVS_OVERRIDE_PATH'] = toolchain
+    os.environ['GYP_MSVS_VERSION'] = version
+    # We need to make sure windows_sdk_path is set to the automated
+    # toolchain values in GYP_DEFINES, but don't want to override any
+    # otheroptions.express
+    # values there.
+    gyp_defines_dict = gyp.NameValueListToDict(gyp.ShlexEnv('GYP_DEFINES'))
+    gyp_defines_dict['windows_sdk_path'] = win_sdk
+    os.environ['GYP_DEFINES'] = ' '.join('%s=%s' % (k, pipes.quote(str(v)))
+        for k, v in gyp_defines_dict.iteritems())
+    os.environ['WINDOWSSDKDIR'] = win_sdk
+    os.environ['WDK_DIR'] = wdk
+    # Include the VS runtime in the PATH in case it's not machine-installed.
+    runtime_path = os.path.pathsep.join(vs_runtime_dll_dirs)
+    os.environ['PATH'] = runtime_path + os.path.pathsep + os.environ['PATH']
+  elif sys.platform == 'win32' and not depot_tools_win_toolchain:
+    if not 'GYP_MSVS_OVERRIDE_PATH' in os.environ:
+      os.environ['GYP_MSVS_OVERRIDE_PATH'] = DetectVisualStudioPath()
+    if not 'GYP_MSVS_VERSION' in os.environ:
+      os.environ['GYP_MSVS_VERSION'] = GetVisualStudioVersion()
+
+  return vs_runtime_dll_dirs
+
+
+def _RegistryGetValueUsingWinReg(key, value):
+  """Use the _winreg module to obtain the value of a registry key.
+
+  Args:
+    key: The registry key.
+    value: The particular registry value to read.
+  Return:
+    contents of the registry key's value, or None on failure.  Throws
+    ImportError if _winreg is unavailable.
+  """
+  import _winreg
+  try:
+    root, subkey = key.split('\\', 1)
+    assert root == 'HKLM'  # Only need HKLM for now.
+    with _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE, subkey) as hkey:
+      return _winreg.QueryValueEx(hkey, value)[0]
+  except WindowsError:
+    return None
+
+
+def _RegistryGetValue(key, value):
+  try:
+    return _RegistryGetValueUsingWinReg(key, value)
+  except ImportError:
+    raise Exception('The python library _winreg not found.')
+
+
+def GetVisualStudioVersion():
+  """Return GYP_MSVS_VERSION of Visual Studio.
+  """
+  return os.environ.get('GYP_MSVS_VERSION', CURRENT_DEFAULT_TOOLCHAIN_VERSION)
+
+
+def DetectVisualStudioPath():
+  """Return path to the GYP_MSVS_VERSION of Visual Studio.
+  """
+
+  # Note that this code is used from
+  # build/toolchain/win/setup_toolchain.py as well.
+  version_as_year = GetVisualStudioVersion()
+  year_to_version = {
+      '2013': '12.0',
+      '2015': '14.0',
+  }
+  if version_as_year not in year_to_version:
+    raise Exception(('Visual Studio version %s (from GYP_MSVS_VERSION)'
+                     ' not supported. Supported versions are: %s') % (
+                       version_as_year, ', '.join(year_to_version.keys())))
+  version = year_to_version[version_as_year]
+  keys = [r'HKLM\Software\Microsoft\VisualStudio\%s' % version,
+          r'HKLM\Software\Wow6432Node\Microsoft\VisualStudio\%s' % version]
+  for key in keys:
+    path = _RegistryGetValue(key, 'InstallDir')
+    if not path:
+      continue
+    path = os.path.normpath(os.path.join(path, '..', '..'))
+    return path
+
+  raise Exception(('Visual Studio Version %s (from GYP_MSVS_VERSION)'
+                   ' not found.') % (version_as_year))
+
+
+def _VersionNumber():
+  """Gets the standard version number ('120', '140', etc.) based on
+  GYP_MSVS_VERSION."""
+  vs_version = GetVisualStudioVersion()
+  if vs_version == '2013':
+    return '120'
+  elif vs_version == '2015':
+    return '140'
+  else:
+    raise ValueError('Unexpected GYP_MSVS_VERSION')
+
+
+def _CopyRuntimeImpl(target, source, verbose=True):
+  """Copy |source| to |target| if it doesn't already exist or if it
+  needs to be updated.
+  """
+  if (os.path.isdir(os.path.dirname(target)) and
+      (not os.path.isfile(target) or
+      os.stat(target).st_mtime != os.stat(source).st_mtime)):
+    if verbose:
+      print 'Copying %s to %s...' % (source, target)
+    if os.path.exists(target):
+      os.unlink(target)
+    shutil.copy2(source, target)
+
+
+def _CopyRuntime2013(target_dir, source_dir, dll_pattern):
+  """Copy both the msvcr and msvcp runtime DLLs, only if the target doesn't
+  exist, but the target directory does exist."""
+  for file_part in ('p', 'r'):
+    dll = dll_pattern % file_part
+    target = os.path.join(target_dir, dll)
+    source = os.path.join(source_dir, dll)
+    _CopyRuntimeImpl(target, source)
+
+
+def _CopyRuntime2015(target_dir, source_dir, dll_pattern, suffix):
+  """Copy both the msvcp and vccorlib runtime DLLs, only if the target doesn't
+  exist, but the target directory does exist."""
+  for file_part in ('msvcp', 'vccorlib', 'vcruntime'):
+    dll = dll_pattern % file_part
+    target = os.path.join(target_dir, dll)
+    source = os.path.join(source_dir, dll)
+    _CopyRuntimeImpl(target, source)
+  ucrt_src_dir = os.path.join(source_dir, 'api-ms-win-*.dll')
+  print 'Copying %s to %s...' % (ucrt_src_dir, target_dir)
+  for ucrt_src_file in glob.glob(ucrt_src_dir):
+    file_part = os.path.basename(ucrt_src_file)
+    ucrt_dst_file = os.path.join(target_dir, file_part)
+    _CopyRuntimeImpl(ucrt_dst_file, ucrt_src_file, False)
+  _CopyRuntimeImpl(os.path.join(target_dir, 'ucrtbase' + suffix),
+                    os.path.join(source_dir, 'ucrtbase' + suffix))
+
+
+def _CopyRuntime(target_dir, source_dir, target_cpu, debug):
+  """Copy the VS runtime DLLs, only if the target doesn't exist, but the target
+  directory does exist. Handles VS 2013 and VS 2015."""
+  suffix = "d.dll" if debug else ".dll"
+  if GetVisualStudioVersion() == '2015':
+    _CopyRuntime2015(target_dir, source_dir, '%s140' + suffix, suffix)
+  else:
+    _CopyRuntime2013(target_dir, source_dir, 'msvc%s120' + suffix)
+
+  # Copy the PGO runtime library to the release directories.
+  if not debug and os.environ.get('GYP_MSVS_OVERRIDE_PATH'):
+    pgo_x86_runtime_dir = os.path.join(os.environ.get('GYP_MSVS_OVERRIDE_PATH'),
+                                        'VC', 'bin')
+    pgo_x64_runtime_dir = os.path.join(pgo_x86_runtime_dir, 'amd64')
+    pgo_runtime_dll = 'pgort' + _VersionNumber() + '.dll'
+    if target_cpu == "x86":
+      source_x86 = os.path.join(pgo_x86_runtime_dir, pgo_runtime_dll)
+      if os.path.exists(source_x86):
+        _CopyRuntimeImpl(os.path.join(target_dir, pgo_runtime_dll), source_x86)
+    elif target_cpu == "x64":
+      source_x64 = os.path.join(pgo_x64_runtime_dir, pgo_runtime_dll)
+      if os.path.exists(source_x64):
+        _CopyRuntimeImpl(os.path.join(target_dir, pgo_runtime_dll),
+                          source_x64)
+    else:
+      raise NotImplementedError("Unexpected target_cpu value:" + target_cpu)
+
+
+def CopyVsRuntimeDlls(output_dir, runtime_dirs):
+  """Copies the VS runtime DLLs from the given |runtime_dirs| to the output
+  directory so that even if not system-installed, built binaries are likely to
+  be able to run.
+
+  This needs to be run after gyp has been run so that the expected target
+  output directories are already created.
+
+  This is used for the GYP build and gclient runhooks.
+  """
+  x86, x64 = runtime_dirs
+  out_debug = os.path.join(output_dir, 'Debug')
+  out_debug_nacl64 = os.path.join(output_dir, 'Debug', 'x64')
+  out_release = os.path.join(output_dir, 'Release')
+  out_release_nacl64 = os.path.join(output_dir, 'Release', 'x64')
+  out_debug_x64 = os.path.join(output_dir, 'Debug_x64')
+  out_release_x64 = os.path.join(output_dir, 'Release_x64')
+
+  if os.path.exists(out_debug) and not os.path.exists(out_debug_nacl64):
+    os.makedirs(out_debug_nacl64)
+  if os.path.exists(out_release) and not os.path.exists(out_release_nacl64):
+    os.makedirs(out_release_nacl64)
+  _CopyRuntime(out_debug,          x86, "x86", debug=True)
+  _CopyRuntime(out_release,        x86, "x86", debug=False)
+  _CopyRuntime(out_debug_x64,      x64, "x64", debug=True)
+  _CopyRuntime(out_release_x64,    x64, "x64", debug=False)
+  _CopyRuntime(out_debug_nacl64,   x64, "x64", debug=True)
+  _CopyRuntime(out_release_nacl64, x64, "x64", debug=False)
+
+
+def CopyDlls(target_dir, configuration, target_cpu):
+  """Copy the VS runtime DLLs into the requested directory as needed.
+
+  configuration is one of 'Debug' or 'Release'.
+  target_cpu is one of 'x86' or 'x64'.
+
+  The debug configuration gets both the debug and release DLLs; the
+  release config only the latter.
+
+  This is used for the GN build.
+  """
+  vs_runtime_dll_dirs = SetEnvironmentAndGetRuntimeDllDirs()
+  if not vs_runtime_dll_dirs:
+    return
+
+  x64_runtime, x86_runtime = vs_runtime_dll_dirs
+  runtime_dir = x64_runtime if target_cpu == 'x64' else x86_runtime
+  _CopyRuntime(target_dir, runtime_dir, target_cpu, debug=False)
+  if configuration == 'Debug':
+    _CopyRuntime(target_dir, runtime_dir, target_cpu, debug=True)
+
+
+def _GetDesiredVsToolchainHashes():
+  """Load a list of SHA1s corresponding to the toolchains that we want installed
+  to build with."""
+  if GetVisualStudioVersion() == '2015':
+    # Update 2.
+    return ['95ddda401ec5678f15eeed01d2bee08fcbc5ee97']
+  else:
+    return ['03a4e939cd325d6bc5216af41b92d02dda1366a6']
+
+
+def ShouldUpdateToolchain():
+  """Check if the toolchain should be upgraded."""
+  if not os.path.exists(json_data_file):
+    return True
+  with open(json_data_file, 'r') as tempf:
+    toolchain_data = json.load(tempf)
+  version = toolchain_data['version']
+  env_version = GetVisualStudioVersion()
+  # If there's a mismatch between the version set in the environment and the one
+  # in the json file then the toolchain should be updated.
+  return version != env_version
+
+
+def Update(force=False):
+  """Requests an update of the toolchain to the specific hashes we have at
+  this revision. The update outputs a .json of the various configuration
+  information required to pass to gyp which we use in |GetToolchainDir()|.
+  """
+  if force != False and force != '--force':
+    print >>sys.stderr, 'Unknown parameter "%s"' % force
+    return 1
+  if force == '--force' or os.path.exists(json_data_file):
+    force = True
+
+  depot_tools_win_toolchain = \
+      bool(int(os.environ.get('DEPOT_TOOLS_WIN_TOOLCHAIN', '1')))
+  if ((sys.platform in ('win32', 'cygwin') or force) and
+        depot_tools_win_toolchain):
+    import find_depot_tools
+    depot_tools_path = find_depot_tools.add_depot_tools_to_path()
+    # Necessary so that get_toolchain_if_necessary.py will put the VS toolkit
+    # in the correct directory.
+    os.environ['GYP_MSVS_VERSION'] = GetVisualStudioVersion()
+    get_toolchain_args = [
+        sys.executable,
+        os.path.join(depot_tools_path,
+                    'win_toolchain',
+                    'get_toolchain_if_necessary.py'),
+        '--output-json', json_data_file,
+      ] + _GetDesiredVsToolchainHashes()
+    if force:
+      get_toolchain_args.append('--force')
+    subprocess.check_call(get_toolchain_args)
+
+  return 0
+
+
+def NormalizePath(path):
+  while path.endswith("\\"):
+    path = path[:-1]
+  return path
+
+
+def GetToolchainDir():
+  """Gets location information about the current toolchain (must have been
+  previously updated by 'update'). This is used for the GN build."""
+  runtime_dll_dirs = SetEnvironmentAndGetRuntimeDllDirs()
+
+  # If WINDOWSSDKDIR is not set, search the default SDK path and set it.
+  if not 'WINDOWSSDKDIR' in os.environ:
+    default_sdk_path = 'C:\\Program Files (x86)\\Windows Kits\\10'
+    if os.path.isdir(default_sdk_path):
+      os.environ['WINDOWSSDKDIR'] = default_sdk_path
+
+  print '''vs_path = "%s"
+sdk_path = "%s"
+vs_version = "%s"
+wdk_dir = "%s"
+runtime_dirs = "%s"
+''' % (
+      NormalizePath(os.environ['GYP_MSVS_OVERRIDE_PATH']),
+      NormalizePath(os.environ['WINDOWSSDKDIR']),
+      GetVisualStudioVersion(),
+      NormalizePath(os.environ.get('WDK_DIR', '')),
+      os.path.pathsep.join(runtime_dll_dirs or ['None']))
+
+
+def main():
+  commands = {
+      'update': Update,
+      'get_toolchain_dir': GetToolchainDir,
+      'copy_dlls': CopyDlls,
+  }
+  if len(sys.argv) < 2 or sys.argv[1] not in commands:
+    print >>sys.stderr, 'Expected one of: %s' % ', '.join(commands)
+    return 1
+  return commands[sys.argv[1]](*sys.argv[2:])
+
+
+if __name__ == '__main__':
+  sys.exit(main())