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 the first hook (See DEPS). If it detects that
   8 the build should be clobbered, it will delete the contents of the build
   9 directory.
  10
  11 A landmine is tripped when a builder checks out a different revision, and the
  12 diff between the new landmines and the old ones is non-null. At this point, the
  13 build is clobbered.
  14 """
  15
  16 import difflib
  17 import errno
  18 import gyp_environment
  19 import logging
  20 import optparse
  21 import os
  22 import shutil
  23 import sys
  24 import subprocess
  25 import time
  26
  27 import landmine_utils
  28
  29
  30 SRC_DIR = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
  31
  32
  33 def get_build_dir(build_tool, is_iphone=False):
  34   """
  35   Returns output directory absolute path dependent on build and targets.
  36   Examples:
  37     r'c:\b\build\slave\win\build\src\out'
  38     '/mnt/data/b/build/slave/linux/build/src/out'
  39     '/b/build/slave/ios_rel_device/build/src/xcodebuild'
  40
  41   Keep this function in sync with tools/build/scripts/slave/compile.py
  42   """
  43   ret = None
  44   if build_tool == 'xcode':
  45     ret = os.path.join(SRC_DIR, 'xcodebuild')
  46   elif build_tool in ['make', 'ninja', 'ninja-ios']:  # TODO: Remove ninja-ios.
  47     ret = os.path.join(SRC_DIR, os.environ.get('CHROMIUM_OUT_DIR', 'out'))
  48   else:
  49     raise NotImplementedError('Unexpected GYP_GENERATORS (%s)' % build_tool)
  50   return os.path.abspath(ret)
  51
  52
  53 def clobber_if_necessary(new_landmines):
  54   """Does the work of setting, planting, and triggering landmines."""
  55   out_dir = get_build_dir(landmine_utils.builder())
  56   landmines_path = os.path.normpath(os.path.join(out_dir, '..', '.landmines'))
  57   try:
  58     os.makedirs(out_dir)
  59   except OSError as e:
  60     if e.errno == errno.EEXIST:
  61       pass
  62
  63   if os.path.exists(landmines_path):
  64     with open(landmines_path, 'r') as f:
  65       old_landmines = f.readlines()
  66     if old_landmines != new_landmines:
  67       old_date = time.ctime(os.stat(landmines_path).st_ctime)
  68       diff = difflib.unified_diff(old_landmines, new_landmines,
  69           fromfile='old_landmines', tofile='new_landmines',
  70           fromfiledate=old_date, tofiledate=time.ctime(), n=0)
  71       sys.stdout.write('Clobbering due to:\n')
  72       sys.stdout.writelines(diff)
  73
  74       # Clobber contents of build directory but not directory itself: some
  75       # checkouts have the build directory mounted.
  76       for f in os.listdir(out_dir):
  77         path = os.path.join(out_dir, f)
  78         if os.path.isfile(path):
  79           os.unlink(path)
  80         elif os.path.isdir(path):
  81           shutil.rmtree(path)
  82
  83   # Save current set of landmines for next time.
  84   with open(landmines_path, 'w') as f:
  85     f.writelines(new_landmines)
  86
  87
  88 def process_options():
  89   """Returns a list of landmine emitting scripts."""
  90   parser = optparse.OptionParser()
  91   parser.add_option(
  92       '-s', '--landmine-scripts', action='append',
  93       default=[os.path.join(SRC_DIR, 'build', 'get_landmines.py')],
  94       help='Path to the script which emits landmines to stdout. The target '
  95            'is passed to this script via option -t. Note that an extra '
  96            'script can be specified via an env var EXTRA_LANDMINES_SCRIPT.')
  97   parser.add_option('-v', '--verbose', action='store_true',
  98       default=('LANDMINES_VERBOSE' in os.environ),
  99       help=('Emit some extra debugging information (default off). This option '
 100           'is also enabled by the presence of a LANDMINES_VERBOSE environment '
 101           'variable.'))
 102
 103   options, args = parser.parse_args()
 104
 105   if args:
 106     parser.error('Unknown arguments %s' % args)
 107
 108   logging.basicConfig(
 109       level=logging.DEBUG if options.verbose else logging.ERROR)
 110
 111   extra_script = os.environ.get('EXTRA_LANDMINES_SCRIPT')
 112   if extra_script:
 113     return options.landmine_scripts + [extra_script]
 114   else:
 115     return options.landmine_scripts
 116
 117
 118 def main():
 119   landmine_scripts = process_options()
 120
 121   if landmine_utils.builder() in ('dump_dependency_json', 'eclipse'):
 122     return 0
 123
 124   gyp_environment.SetEnvironment()
 125
 126   landmines = []
 127   for s in landmine_scripts:
 128     proc = subprocess.Popen([sys.executable, s], stdout=subprocess.PIPE)
 129     output, _ = proc.communicate()
 130     landmines.extend([('%s\n' % l.strip()) for l in output.splitlines()])
 131   clobber_if_necessary(landmines)
 132
 133   return 0
 134
 135
 136 if __name__ == '__main__':
 137   sys.exit(main())