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"""
7This script runs every build as a hook. If it detects that the build should
8be clobbered, it will touch the file <build_dir>/.landmine_triggered. The
9various build scripts will then check for the presence of this file and clobber
10accordingly. The script will also emit the reasons for the clobber to stdout.
11
12A landmine is tripped when a builder checks out a different revision, and the
13diff between the new landmines and the old ones is non-null. At this point, the
14build is clobbered.
15"""
16
17import difflib
18import errno
19import logging
20import optparse
21import os
22import sys
23import subprocess
24import time
25
26import landmine_utils
27
28
29SRC_DIR = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
30
31
32def get_target_build_dir(build_tool, target, is_iphone=False):
33  """
34  Returns output directory absolute path dependent on build and targets.
35  Examples:
36    r'c:\b\build\slave\win\build\src\out\Release'
37    '/mnt/data/b/build/slave/linux/build/src/out/Debug'
38    '/b/build/slave/ios_rel_device/build/src/xcodebuild/Release-iphoneos'
39
40  Keep this function in sync with tools/build/scripts/slave/compile.py
41  """
42  ret = None
43  if build_tool == 'xcode':
44    ret = os.path.join(SRC_DIR, 'xcodebuild',
45        target + ('-iphoneos' if is_iphone else ''))
46  elif build_tool in ['make', 'ninja', 'ninja-ios']:  # TODO: Remove ninja-ios.
47    ret = os.path.join(SRC_DIR, 'out', target)
48  elif build_tool in ['msvs', 'vs', 'ib']:
49    ret = os.path.join(SRC_DIR, 'build', target)
50  else:
51    raise NotImplementedError('Unexpected GYP_GENERATORS (%s)' % build_tool)
52  return os.path.abspath(ret)
53
54
55def set_up_landmines(target, new_landmines):
56  """Does the work of setting, planting, and triggering landmines."""
57  out_dir = get_target_build_dir(landmine_utils.builder(), target,
58                                 landmine_utils.platform() == 'ios')
59
60  landmines_path = os.path.join(out_dir, '.landmines')
61  try:
62    os.makedirs(out_dir)
63  except OSError as e:
64    if e.errno == errno.EEXIST:
65      pass
66
67  if os.path.exists(landmines_path):
68    triggered = os.path.join(out_dir, '.landmines_triggered')
69    with open(landmines_path, 'r') as f:
70      old_landmines = f.readlines()
71    if old_landmines != new_landmines:
72      old_date = time.ctime(os.stat(landmines_path).st_ctime)
73      diff = difflib.unified_diff(old_landmines, new_landmines,
74          fromfile='old_landmines', tofile='new_landmines',
75          fromfiledate=old_date, tofiledate=time.ctime(), n=0)
76
77      with open(triggered, 'w') as f:
78        f.writelines(diff)
79    elif os.path.exists(triggered):
80      # Remove false triggered landmines.
81      os.remove(triggered)
82  with open(landmines_path, 'w') as f:
83    f.writelines(new_landmines)
84
85
86def process_options():
87  """Returns a list of landmine emitting scripts."""
88  parser = optparse.OptionParser()
89  parser.add_option(
90      '-s', '--landmine-scripts', action='append',
91      default=[os.path.join(SRC_DIR, 'build', 'get_landmines.py')],
92      help='Path to the script which emits landmines to stdout. The target '
93           'is passed to this script via option -t. Note that an extra '
94           'script can be specified via an env var EXTRA_LANDMINES_SCRIPT.')
95  parser.add_option('-v', '--verbose', action='store_true',
96      default=('LANDMINES_VERBOSE' in os.environ),
97      help=('Emit some extra debugging information (default off). This option '
98          'is also enabled by the presence of a LANDMINES_VERBOSE environment '
99          'variable.'))
100
101  options, args = parser.parse_args()
102
103  if args:
104    parser.error('Unknown arguments %s' % args)
105
106  logging.basicConfig(
107      level=logging.DEBUG if options.verbose else logging.ERROR)
108
109  extra_script = os.environ.get('EXTRA_LANDMINES_SCRIPT')
110  if extra_script:
111    return options.landmine_scripts + [extra_script]
112  else:
113    return options.landmine_scripts
114
115
116def main():
117  landmine_scripts = process_options()
118
119  if landmine_utils.builder() in ('dump_dependency_json', 'eclipse'):
120    return 0
121
122  for target in ('Debug', 'Release', 'Debug_x64', 'Release_x64'):
123    landmines = []
124    for s in landmine_scripts:
125      proc = subprocess.Popen([sys.executable, s, '-t', target],
126                              stdout=subprocess.PIPE)
127      output, _ = proc.communicate()
128      landmines.extend([('%s\n' % l.strip()) for l in output.splitlines()])
129    set_up_landmines(target, landmines)
130
131  return 0
132
133
134if __name__ == '__main__':
135  sys.exit(main())
136