Add landmines support.

The scripts are copied from chromium/src/build and simplified.

BUG=
R=jkummerow@chromium.org, jochen@chromium.org

Review URL: https://codereview.chromium.org/405373005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22529 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

build/get_landmines.py

+#!/usr/bin/env python
+# Copyright 2014 the V8 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.
+
+"""
+This file emits the list of reasons why a particular build needs to be clobbered
+(or a list of 'landmines').
+"""
+
+import sys
+
+
+def main():
+  """
+  ALL LANDMINES ARE EMITTED FROM HERE.
+  """
+  # TODO(machenbach): Uncomment to test if landmines work.
+  # print 'Need to clobber after ICU52 roll.'
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())

build/gyp_v8

@@ -34,6 +34,7 @@ import glob
 import os
 import platform
 import shlex
+import subprocess
 import sys
 
 script_dir = os.path.dirname(os.path.realpath(__file__))
@@ -107,6 +108,14 @@ def additional_include_files(args=[]):
 
 def run_gyp(args):
   rc = gyp.main(args)
+
+  # Check for landmines (reasons to clobber the build). This must be run here,
+  # rather than a separate runhooks step so that any environment modifications
+  # from above are picked up.
+  print 'Running build/landmines.py...'
+  subprocess.check_call(
+      [sys.executable, os.path.join(script_dir, 'landmines.py')])
+
   if rc != 0:
     print 'Error running GYP'
     sys.exit(rc)

build/landmine_utils.py

+# Copyright 2014 the V8 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.
+
+
+import functools
+import logging
+import os
+import shlex
+import sys
+
+
+def memoize(default=None):
+  """This decorator caches the return value of a parameterless pure function"""
+  def memoizer(func):
+    val = []
+    @functools.wraps(func)
+    def inner():
+      if not val:
+        ret = func()
+        val.append(ret if ret is not None else default)
+        if logging.getLogger().isEnabledFor(logging.INFO):
+          print '%s -> %r' % (func.__name__, val[0])
+      return val[0]
+    return inner
+  return memoizer
+
+
+@memoize()
+def IsWindows():
+  return sys.platform in ['win32', 'cygwin']
+
+
+@memoize()
+def IsLinux():
+  return sys.platform.startswith(('linux', 'freebsd'))
+
+
+@memoize()
+def IsMac():
+  return sys.platform == 'darwin'
+
+
+@memoize()
+def gyp_defines():
+  """Parses and returns GYP_DEFINES env var as a dictionary."""
+  return dict(arg.split('=', 1)
+      for arg in shlex.split(os.environ.get('GYP_DEFINES', '')))
+
+@memoize()
+def gyp_msvs_version():
+  return os.environ.get('GYP_MSVS_VERSION', '')
+
+@memoize()
+def distributor():
+  """
+  Returns a string which is the distributed build engine in use (if any).
+  Possible values: 'goma', 'ib', ''
+  """
+  if 'goma' in gyp_defines():
+    return 'goma'
+  elif IsWindows():
+    if 'CHROME_HEADLESS' in os.environ:
+      return 'ib' # use (win and !goma and headless) as approximation of ib
+
+
+@memoize()
+def platform():
+  """
+  Returns a string representing the platform this build is targetted for.
+  Possible values: 'win', 'mac', 'linux', 'ios', 'android'
+  """
+  if 'OS' in gyp_defines():
+    if 'android' in gyp_defines()['OS']:
+      return 'android'
+    else:
+      return gyp_defines()['OS']
+  elif IsWindows():
+    return 'win'
+  elif IsLinux():
+    return 'linux'
+  else:
+    return 'mac'
+
+
+@memoize()
+def builder():
+  """
+  Returns a string representing the build engine (not compiler) to use.
+  Possible values: 'make', 'ninja', 'xcode', 'msvs', 'scons'
+  """
+  if 'GYP_GENERATORS' in os.environ:
+    # for simplicity, only support the first explicit generator
+    generator = os.environ['GYP_GENERATORS'].split(',')[0]
+    if generator.endswith('-android'):
+      return generator.split('-')[0]
+    elif generator.endswith('-ninja'):
+      return 'ninja'
+    else:
+      return generator
+  else:
+    if platform() == 'android':
+      # Good enough for now? Do any android bots use make?
+      return 'make'
+    elif platform() == 'ios':
+      return 'xcode'
+    elif IsWindows():
+      return 'msvs'
+    elif IsLinux():
+      return 'make'
+    elif IsMac():
+      return 'xcode'
+    else:
+      assert False, 'Don\'t know what builder we\'re using!'

build/landmines.py

+#!/usr/bin/env python
+# Copyright 2014 the V8 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.
+
+"""
+This script runs every build as a hook. If it detects that the build should
+be clobbered, it will touch the file <build_dir>/.landmine_triggered. The
+various build scripts will then check for the presence of this file and clobber
+accordingly. The script will also emit the reasons for the clobber to stdout.
+
+A landmine is tripped when a builder checks out a different revision, and the
+diff between the new landmines and the old ones is non-null. At this point, the
+build is clobbered.
+"""
+
+import difflib
+import logging
+import optparse
+import os
+import sys
+import subprocess
+import time
+
+import landmine_utils
+
+
+SRC_DIR = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
+
+
+def get_target_build_dir(build_tool, target):
+  """
+  Returns output directory absolute path dependent on build and targets.
+  Examples:
+    r'c:\b\build\slave\win\build\src\out\Release'
+    '/mnt/data/b/build/slave/linux/build/src/out/Debug'
+    '/b/build/slave/ios_rel_device/build/src/xcodebuild/Release-iphoneos'
+
+  Keep this function in sync with tools/build/scripts/slave/compile.py
+  """
+  ret = None
+  if build_tool == 'xcode':
+    ret = os.path.join(SRC_DIR, 'xcodebuild', target)
+  elif build_tool in ['make', 'ninja', 'ninja-ios']:  # TODO: Remove ninja-ios.
+    ret = os.path.join(SRC_DIR, 'out', target)
+  elif build_tool in ['msvs', 'vs', 'ib']:
+    ret = os.path.join(SRC_DIR, 'build', target)
+  else:
+    raise NotImplementedError('Unexpected GYP_GENERATORS (%s)' % build_tool)
+  return os.path.abspath(ret)
+
+
+def set_up_landmines(target, new_landmines):
+  """Does the work of setting, planting, and triggering landmines."""
+  out_dir = get_target_build_dir(landmine_utils.builder(), target)
+
+  landmines_path = os.path.join(out_dir, '.landmines')
+  if not os.path.exists(out_dir):
+    return
+
+  if os.path.exists(landmines_path):
+    triggered = os.path.join(out_dir, '.landmines_triggered')
+    with open(landmines_path, 'r') as f:
+      old_landmines = f.readlines()
+    if old_landmines != new_landmines:
+      old_date = time.ctime(os.stat(landmines_path).st_ctime)
+      diff = difflib.unified_diff(old_landmines, new_landmines,
+          fromfile='old_landmines', tofile='new_landmines',
+          fromfiledate=old_date, tofiledate=time.ctime(), n=0)
+
+      with open(triggered, 'w') as f:
+        f.writelines(diff)
+    elif os.path.exists(triggered):
+      # Remove false triggered landmines.
+      os.remove(triggered)
+  with open(landmines_path, 'w') as f:
+    f.writelines(new_landmines)
+
+
+def process_options():
+  """Returns a list of landmine emitting scripts."""
+  parser = optparse.OptionParser()
+  parser.add_option(
+      '-s', '--landmine-scripts', action='append',
+      default=[os.path.join(SRC_DIR, 'build', 'get_landmines.py')],
+      help='Path to the script which emits landmines to stdout. The target '
+           'is passed to this script via option -t. Note that an extra '
+           'script can be specified via an env var EXTRA_LANDMINES_SCRIPT.')
+  parser.add_option('-v', '--verbose', action='store_true',
+      default=('LANDMINES_VERBOSE' in os.environ),
+      help=('Emit some extra debugging information (default off). This option '
+          'is also enabled by the presence of a LANDMINES_VERBOSE environment '
+          'variable.'))
+
+  options, args = parser.parse_args()
+
+  if args:
+    parser.error('Unknown arguments %s' % args)
+
+  logging.basicConfig(
+      level=logging.DEBUG if options.verbose else logging.ERROR)
+
+  extra_script = os.environ.get('EXTRA_LANDMINES_SCRIPT')
+  if extra_script:
+    return options.landmine_scripts + [extra_script]
+  else:
+    return options.landmine_scripts
+
+
+def main():
+  landmine_scripts = process_options()
+
+  if landmine_utils.builder() in ('dump_dependency_json', 'eclipse'):
+    return 0
+
+  landmines = []
+  for s in landmine_scripts:
+    proc = subprocess.Popen([sys.executable, s], stdout=subprocess.PIPE)
+    output, _ = proc.communicate()
+    landmines.extend([('%s\n' % l.strip()) for l in output.splitlines()])
+
+  for target in ('Debug', 'Release'):
+    set_up_landmines(target, landmines)
+
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())