client/goma-make

#!/usr/bin/python3
#
# Copyright 2012 The Goma Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""A thin wrapper of make command for Chromium OS build.

Unfortunately, there are several packages with which we cannot specify
-j option. For such packages, we modify PATH environment variable not
to use goma.
"""

import os
import sys


_DENYLIST = [
 '/dev-libs/nss', # make -j fails
 '/app-crypt/nss', # make -j fails
 '/dev-libs/m17n-lib', # make -j fails
 '/sys-fs/mtools', # make -j fails
 '/dev-java/icedtea', # make -j fails
 '/dev-libs/openssl', # Makefile force -j1
 ]


def GetDenylist():
 """Returns list of portage package names to deny.

 The contents should be list of directories like:
 /dev-libs/nss
 /sys-fs/mtools

 Returns:
 a list of denied directories.
 """
 return _DENYLIST


def IsDenied(path, denylist):
 """Determine whether a path belongs to some denied package.

 Args:
 path: path of a portage package

 Returns:
 True if the portage package has been denied.
 """
 for exemption_path in denylist:
 if path.find(exemption_path) != -1:
 return True
 return False


def RemoveGomaFromPath():
 """Remove the goma directory from the search path.

 This will force a non-goma build, as needed for denied packages.
 """
 if not os.environ.get('GOMA_DIR'):
 return
 goma_dir = os.getenv('GOMA_DIR')
 paths = os.getenv('PATH').split(os.pathsep)
 paths = [path for path in paths if not path.startswith(goma_dir)]
 os.putenv('PATH', os.pathsep.join(paths))


def RemoveParallelBuildArguments(args):
 """Remove parallel-build related arguments.
 This avoids passing unreasonably-high values into non-goma builds.

 Args:
 args: the arguments list to modify.
 """

 # This processing assumes simple '-j ###' or '-j###' formatted arguments.
 # More complex combinations (e.g. '-vj10') will be ignored entirely.
 parallel_args = ['-j']

 for idx, arg in enumerate(args):
 if arg == None:
 pass # Already marked this element for removal
 elif arg in parallel_args: # '-j ###' format
 args[idx + 0] = None
 if idx + 1 < len(args):
 args[idx + 1] = None
 elif arg[0:2] in parallel_args: # '-j###' format
 args[idx + 0] = None

 args[:] = filter(lambda x: x != None, args)
 return args


def main():
 args = ['/usr/bin/make']
 args.extend(sys.argv[1:])
 denylist = GetDenylist()
 # Regardless of with/without goma, make is limited to under certain
 # load average.
 args[1:1] = ['-l10']
 if os.getenv('MAKELEVEL'):
 # In a sub-make, do not modify the flags.
 pass
 elif IsDenied(os.getcwd(), denylist) or os.getuid() == 0:
 # A root user cannot talk to goma.
 RemoveGomaFromPath()
 RemoveParallelBuildArguments(args)
 if os.environ.get('GOMA_DIR'):
 del os.environ['GOMA_DIR']
 if os.environ.get('GOMACC_PATH'):
 del os.environ['GOMACC_PATH']
 else:
 # Insert default flags at the beginning of the argument list.
 # These will be overridden by any user-supplied options.
 RemoveGomaFromPath()
 if os.environ.get('GOMA_DIR'):
 os.environ['GOMACC_PATH'] = os.path.join(os.environ['GOMA_DIR'], 'gomacc')
 args[1:1] = ['-j100']

 os.execv(args[0], args)


if __name__ == '__main__':
 main()