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      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())
    138