configure

#!/usr/bin/env python3
#
# Copyright 2016, 2017 Chris Cummins <chrisc.101@gmail.com>.
#
# This file is part of CLgen.
#
# CLgen is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# CLgen is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with CLgen.  If not, see <http://www.gnu.org/licenses/>.
#
import json
import sys
from argparse import ArgumentParser


def yes_no(question, default="no"):
  """Ask a yes/no question and return user's answer.

  "question" is a string that is presented to the user.
  "default" is the presumed answer if the user just hits <Enter>.
      It must be "yes" (the default), "no" or None (meaning
      an answer is required of the user).

  The "answer" return value is True for "yes" or False for "no".
  """
  valid = {"yes": True, "y": True, "ye": True,
           "no": False, "n": False}
  if default is None:
    prompt = " [y/n] "
  elif default == "yes":
    prompt = " [Y/n] "
  elif default == "no":
    prompt = " [y/N] "
  else:
    raise ValueError("invalid default answer: '%s'" % default)

  while True:
    sys.stdout.write(question + prompt)
    if sys.version_info >= (3, 0):
      choice = input().lower()
    else:
      choice = raw_input().lower()

    if default is not None and choice == '':
      return valid[default]
    elif choice in valid:
      return valid[choice]
    else:
      sys.stdout.write("Please respond with 'yes' or 'no' "
                       "(or 'y' or 'n').\n")


def to_make(val):
  return str(int(val))


def to_python(val):
  return "True" if val else "False"


def to_text(val):
  return "yes" if val else "no"


def main():
  parser = ArgumentParser(description="Configure build.")
  parser.add_argument("-r", "--reconfigure", action="store_true",
                      help="re-run configuraiton using previous settings")
  parser.add_argument("-b", "--batch", action="store_true",
                      help="defaults all options to 'no'. Override with:")
  parser.add_argument("--with-cuda", action="store_true")
  args = parser.parse_args()

  if args.reconfigure:
    args.batch = True
    try:
      with open(".config.json") as infile:
        cfg = json.loads(infile.read())
    except FileNotFoundError:
      print("you must run ./configure first", file=sys.stderr)
      sys.exit(1)
  else:
    cfg = {
      "cuda": args.with_cuda,
    }

  # get input from user
  if not args.batch:
    if not cfg["cuda"]:
      cfg["cuda"] = yes_no(
          "Enable CUDA support? (requires NVIDIA GPU with CUDA 8.0 and cuDNN)")

  # generate JSON config file
  with open(".config.json", "w") as outfile:
    json.dump(cfg, outfile)

  # generate make config file
  with open(".config.make", "w") as outfile:
    print("USE_CUDA := " + to_make(cfg["cuda"]), file=outfile)

  # generate python config file
  with open(".config.py", "w") as outfile:
    print("USE_CUDA = " + to_python(cfg["cuda"]), file=outfile)

  print()
  print("You may now run 'make'.")


if __name__ == "__main__":
  try:
    main()
  except KeyboardInterrupt:
    print("\naborting without writing changes", file=sys.stderr)
    sys.exit(1)