Initial attempt to add support for using gyp to build V8 itself...

build/gyp_v8

+#!/usr/bin/python
+#
+# Copyright 2010 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 glob
+import os
+import shlex
+import sys
+
+script_dir = os.path.dirname(__file__)
+v8_root = os.path.normpath(os.path.join(script_dir, os.pardir))
+
+sys.path.insert(0, os.path.join(v8_root, 'build', 'gyp', 'pylib'))
+import gyp
+
+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 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 common.gypi & features_override.gypi
+  AddInclude(os.path.join(script_dir, 'common.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
+
+if __name__ == '__main__':
+  args = sys.argv[1:]
+
+  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)
+
+  # 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=' + 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()
+
+  # Off we go...
+  sys.exit(gyp.main(args))