Refactor landmines.py so that it can be used downstream.

build/get_landmines.py

Index: build/get_landmines.py
diff --git a/build/get_landmines.py b/build/get_landmines.py
new file mode 100755
index 0000000000000000000000000000000000000000..53fea0f002b13d9d234df76dc43c79acbb094cba
--- /dev/null
+++ b/build/get_landmines.py
@@ -0,0 +1,63 @@
+#!/usr/bin/env python
+# Copyright (c) 2013 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 emits the list of reasons why a particular build needs to be clobbered
+(or a list of 'landmines').
+"""
+
+import optparse
+import sys
+
+import landmine_utils
+
+
+builder = landmine_utils.platform
+distributor = landmine_utils.distributor
+gyp_defines = landmine_utils.gyp_defines
+gyp_msvs_version = landmine_utils.gyp_msvs_version
+platform = landmine_utils.platform
+
+
+def print_landmines(target):
+  """
+  ALL LANDMINES ARE EMITTED FROM HERE.
+  target can be one of {'Release', 'Debug', 'Debug_x64', 'Release_x64'}.
+  """
+  if (distributor() == 'goma' and platform() == 'win32' and
+      builder() == 'ninja'):
+    print 'Need to clobber winja goma due to backend cwd cache fix.'
+  if platform() == 'android':
+    print 'Clobber: Resources removed in r195014 require clobber.'
+  if platform() == 'win' and builder() == 'ninja':
+    print 'Compile on cc_unittests fails due to symbols removed in r185063.'
+  if platform() == 'linux' and builder() == 'ninja':
+    print 'Builders switching from make to ninja will clobber on this.'
+  if platform() == 'mac':
+    print 'Switching from bundle to unbundled dylib (issue 14743002).'
+  if (platform() == 'win' and builder() == 'ninja' and
+      gyp_msvs_version() == '2012' and
+      gyp_defines().get('target_arch') == 'x64' and
+      gyp_defines().get('dcheck_always_on') == '1'):
+    print "Switched win x64 trybots from VS2010 to VS2012."
+  print 'Need to clobber everything due to an IDL change in r154579 (blink)'
+
+
+def main():
+  parser = optparse.OptionParser()
+  parser.add_option('-t', '--target',
+                    help=='Target for which the landmines have to be emitted')
+
+  options, args = parser.parse_args()
+
+  if args:
+    parser.error('Unknown arguments %s' % args)
+
+  print_landmines(options.target)
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())