Parameterize the Google Update appid at build time instead of hard coding it ...

chrome/tools/build/appid.py

Index: chrome/tools/build/appid.py
===================================================================
--- chrome/tools/build/appid.py	(revision 0)
+++ chrome/tools/build/appid.py	(revision 0)
@@ -0,0 +1,52 @@
+#!/usr/bin/env python
+# Copyright (c) 2009 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+appid.py -- Chromium appid header file generation utility.
+"""
+
+import optparse
+import sys
+
+GENERATED_APPID_INCLUDE_FILE_CONTENTS = """
+// This file is automatically generated by appid.py.
+// It contains the Google Update Appid used for this build. Note that
+// the Appid will be empty for non Google Chrome builds.
+namespace google_update {
+const wchar_t kChromeGuid[] = L"%s";
+}
+"""
+
+def GenerateAppIdHeader(opts):
+  contents = GENERATED_APPID_INCLUDE_FILE_CONTENTS % opts.appid
+
+  output_file = open(opts.output_file, 'w')
+  try:
+    output_file.write(contents)

[sgk, 2009/09/03 00:25:23]

...you're writing out the .h file contents *every time* even if the id is the
same as last time.  This is causing the timestamp on the generated .h file to
change every time, which causes installer_util to recompile
google_update_constants.cc every time, which causes chrome.dll to relink *every*
build, even when nothing has changed.

When you're running an action like this every build, you *must* compare the
output you would generate against the current contents of file, and only write
it out if there's a difference.

I'm prepping a CL to fix this.

+  finally:
+    output_file.close()
+
+def main():
+  parser = optparse.OptionParser()
+  parser.add_option('-a', '--appid',
+                    help='The Google Update App Id of the Chrome being built.')
+  parser.add_option('-o', '--output_file',
+                    help='The path to the generated output header file')
+
+  (opts, args) = parser.parse_args()
+
+  if opts.appid is None or not opts.output_file:
+    parser.print_help()
+    return 1
+
+  # Log a trace in the build output when we run.
+  print "Generating appid header... ",
+  GenerateAppIdHeader(opts)
+
+  print "Done."
+
+
+if __name__ == '__main__':
+  sys.exit(main())