Landmines support to ease clobbering builds

webrtc/build/get_landmines.py

+#!/usr/bin/env python
+# Copyright (c) 2015 The WebRTC 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 in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+"""
+This file emits the list of reasons why a particular build needs to be clobbered
+(or a list of 'landmines').
+"""
+
+import os
+import sys
+
+script_dir = os.path.dirname(os.path.realpath(__file__))

[Michael Achenbach, 2015/10/15 07:38:20]

Lines 18-28 allow optimizations, i.e. you can use those tools to not clobber on
all platforms etc. But if that's not of importance for webrtc (i.e. if you build
fast enough) you could also delete those to not confuse people.

[kjellander_chromium, 2015/10/15 10:51:41]

I left them in there for simplicity when adding future clobbering for specific
configurations.
I also added a link to the Chromium get_landmines.py so it's easy to find
examples of usage.

+checkout_root = os.path.abspath(os.path.join(script_dir, os.pardir, os.pardir))
+sys.path.insert(0, os.path.join(checkout_root, 'build'))
+import landmine_utils
+
+
+builder = landmine_utils.builder
+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():
+  """
+  ALL LANDMINES ARE EMITTED FROM HERE.
+  """
+  # DO NOT add landmines as part of a regular CL. Landmines are a last-effort
+  # bandaid fix if a CL that got landed has a build dependency bug and all bots
+  # need to be cleaned up. If you're writing a new CL that causes build
+  # dependency problems, fix the dependency problems instead of adding a
+  # landmine.
+  print 'Clobber to fix GN build (webrtc:5070)'
+
+
+def main():
+  print_landmines()
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())