build/landmines.py

   1 #!/usr/bin/env python
   2 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   3 # Use of this source code is governed by a BSD-style license that can be
   4 # found in the LICENSE file.
   5
   6 """
   7 This script runs every build as a hook. If it detects that the build should
   8 be clobbered, it will touch the file <build_dir>/.landmine_triggered. The
   9 various build scripts will then check for the presence of this file and clobber
  10 accordingly. The script will also emit the reasons for the clobber to stdout.
  11
  12 A landmine is tripped when a builder checks out a different revision, and the
  13 diff between the new landmines and the old ones is non-null. At this point, the
  14 build is clobbered.
  15 """
  16
  17 import difflib
  18 import logging
  19 import optparse
  20 import os
  21 import sys
  22 import subprocess
  23 import time
  24
  25 import landmine_utils
  26
  27
  28 SRC_DIR = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
  29
  30
  31 def get_target_build_dir(build_tool, target, is_iphone=False):
  32   """
  33   Returns output directory absolute path dependent on build and targets.
  34   Examples:
  35     r'c:\b\build\slave\win\build\src\out\Release'
  36     '/mnt/data/b/build/slave/linux/build/src/out/Debug'
  37     '/b/build/slave/ios_rel_device/build/src/xcodebuild/Release-iphoneos'
  38
  39   Keep this function in sync with tools/build/scripts/slave/compile.py
  40   """
  41   ret = None
  42   if build_tool == 'xcode':
  43     ret = os.path.join(SRC_DIR, 'xcodebuild',
  44         target + ('-iphoneos' if is_iphone else ''))
  45   elif build_tool in ['make', 'ninja', 'ninja-ios']:  # TODO: Remove ninja-ios.
  46     ret = os.path.join(SRC_DIR, 'out', target)
  47   elif build_tool in ['msvs', 'vs', 'ib']:
  48     ret = os.path.join(SRC_DIR, 'build', target)
  49   else:
  50     raise NotImplementedError('Unexpected GYP_GENERATORS (%s)' % build_tool)
  51   return os.path.abspath(ret)
  52
  53
  54 def set_up_landmines(target, new_landmines):
  55   """Does the work of setting, planting, and triggering landmines."""
  56   out_dir = get_target_build_dir(landmine_utils.builder(), target,
  57                                  landmine_utils.platform() == 'ios')
  58
  59   landmines_path = os.path.join(out_dir, '.landmines')
  60   if not os.path.exists(out_dir):
  61     os.makedirs(out_dir)
  62
  63   if not os.path.exists(landmines_path):
  64     with open(landmines_path, 'w') as f:
  65       f.writelines(new_landmines)
  66   else:
  67     triggered = os.path.join(out_dir, '.landmines_triggered')
  68     with open(landmines_path, 'r') as f:
  69       old_landmines = f.readlines()
  70     if old_landmines != new_landmines:
  71       old_date = time.ctime(os.stat(landmines_path).st_ctime)
  72       diff = difflib.unified_diff(old_landmines, new_landmines,
  73           fromfile='old_landmines', tofile='new_landmines',
  74           fromfiledate=old_date, tofiledate=time.ctime(), n=0)
  75
  76       with open(triggered, 'w') as f:
  77         f.writelines(diff)
  78     elif os.path.exists(triggered):
  79       # Remove false triggered landmines.
  80       os.remove(triggered)
  81
  82
  83 def process_options():
  84   """Returns a list of landmine emitting scripts."""
  85   parser = optparse.OptionParser()
  86   parser.add_option(
  87       '-s', '--landmine-scripts', action='append',
  88       default=[os.path.join(SRC_DIR, 'build', 'get_landmines.py')],
  89       help='Path to the script which emits landmines to stdout. The target '
  90            'is passed to this script via option -t. Note that an extra '
  91            'script can be specified via an env var EXTRA_LANDMINES_SCRIPT.')
  92   parser.add_option('-v', '--verbose', action='store_true',
  93       default=('LANDMINES_VERBOSE' in os.environ),
  94       help=('Emit some extra debugging information (default off). This option '
  95           'is also enabled by the presence of a LANDMINES_VERBOSE environment '
  96           'variable.'))
  97
  98   options, args = parser.parse_args()
  99
 100   if args:
 101     parser.error('Unknown arguments %s' % args)
 102
 103   logging.basicConfig(
 104       level=logging.DEBUG if options.verbose else logging.ERROR)
 105
 106   extra_script = os.environ.get('EXTRA_LANDMINES_SCRIPT')
 107   if extra_script:
 108     return options.landmine_scripts + [extra_script]
 109   else:
 110     return options.landmine_scripts
 111
 112
 113 def main():
 114   landmine_scripts = process_options()
 115
 116   if landmine_utils.builder() == 'dump_dependency_json':
 117     return 0
 118
 119   for target in ('Debug', 'Release', 'Debug_x64', 'Release_x64'):
 120     landmines = []
 121     for s in landmine_scripts:
 122       proc = subprocess.Popen([sys.executable, s, '-t', target],
 123                               stdout=subprocess.PIPE)
 124       output, _ = proc.communicate()
 125       landmines.extend([('%s\n' % l.strip()) for l in output.splitlines()])
 126     set_up_landmines(target, landmines)
 127
 128   return 0
 129
 130
 131 if __name__ == '__main__':
 132   sys.exit(main())