text: # Copyright 2012-2021 The Meson development team
  
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  
  #     http://www.apache.org/licenses/LICENSE-2.0
  
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  from . import mlog, mparser
  import pickle, os, uuid
  import sys
  from itertools import chain
  from pathlib import PurePath
  from collections import OrderedDict
  from .mesonlib import (
      HoldableObject,
      MesonException, EnvironmentException, MachineChoice, PerMachine,
      PerMachineDefaultable, default_libdir, default_libexecdir,
      default_prefix, split_args, OptionKey, OptionType, stringlistify,
  )
  from .wrap import WrapMode
  import ast
  import argparse
  import configparser
  import enum
  import shlex
  import typing as T
  
  if T.TYPE_CHECKING:
      from . import dependencies
      from .compilers.compilers import Compiler, CompileResult
      from .environment import Environment
      from .mesonlib import OptionOverrideProxy, FileOrString
      from .cmake.traceparser import CMakeCacheEntry
  
      OptionDictType = T.Union[T.Dict[str, 'UserOption[T.Any]'], OptionOverrideProxy]
      KeyedOptionDictType = T.Union[T.Dict['OptionKey', 'UserOption[T.Any]'], OptionOverrideProxy]
      CompilerCheckCacheKey = T.Tuple[T.Tuple[str, ...], str, FileOrString, T.Tuple[str, ...], str]
  
  # Check major_versions_differ() if changing versioning scheme.
  version = '0.60.0.rc2'
  backendlist = ['ninja', 'vs', 'vs2010', 'vs2012', 'vs2013', 'vs2015', 'vs2017', 'vs2019', 'xcode']
  
  default_yielding = False
  
  # Can't bind this near the class method it seems, sadly.
  _T = T.TypeVar('_T')
  
  
  class MesonVersionMismatchException(MesonException):
      '''Build directory generated with Meson version is incompatible with current version'''
      def __init__(self, old_version: str, current_version: str) -> None:
          super().__init__(f'Build directory has been generated with Meson version {old_version}, '
                           f'which is incompatible with the current version {current_version}.')
          self.old_version = old_version
          self.current_version = current_version
  
  
  class UserOption(T.Generic[_T], HoldableObject):
      def __init__(self, description: str, choices: T.Optional[T.Union[str, T.List[_T]]], yielding: T.Optional[bool]):
          super().__init__()
          self.choices = choices
          self.description = description
          if yielding is None:
              yielding = default_yielding
          if not isinstance(yielding, bool):
              raise MesonException('Value of "yielding" must be a boolean.')
          self.yielding = yielding
          self.deprecated: T.Union[bool, T.Dict[str, str], T.List[str]] = False
  
      def listify(self, value: T.Any) -> T.List[T.Any]:
          return [value]
  
      def printable_value(self) -> T.Union[str, int, bool, T.List[T.Union[str, int, bool]]]:
          assert isinstance(self.value, (str, int, bool, list))
          return self.value
  
      # Check that the input is a valid value and return the
      # "cleaned" or "native" version. For example the Boolean
      # option could take the string "true" and return True.
      def validate_value(self, value: T.Any) -> _T:
          raise RuntimeError('Derived option class did not override validate_value.')
  
      def set_value(self, newvalue: T.Any) -> None:
          self.value = self.validate_value(newvalue)
  
  class UserStringOption(UserOption[str]):
      def __init__(self, description: str, value: T.Any, yielding: T.Optional[bool] = None):
          super().__init__(description, None, yielding)
          self.set_value(value)
  
      def validate_value(self, value: T.Any) -> str:
          if not isinstance(value, str):
              raise MesonException('Value "%s" for string option is not a string.' % str(value))
          return value
  
  class UserBooleanOption(UserOption[bool]):
      def __init__(self, description: str, value, yielding: T.Optional[bool] = None) -> None:
          super().__init__(description, [True, False], yielding)
          self.set_value(value)
  
      def __bool__(self) -> bool:
          return self.value
  
      def validate_value(self, value: T.Any) -> bool:
          if isinstance(value, bool):
              return value
          if not isinstance(value, str):
              raise MesonException(f'Value {value} cannot be converted to a boolean')
          if value.lower() == 'true':
              return True
          if value.lower() == 'false':
              return False
          raise MesonException('Value %s is not boolean (true or false).' % value)
  
  class UserIntegerOption(UserOption[int]):
      def __init__(self, description: str, value: T.Any, yielding: T.Optional[bool] = None):
          min_value, max_value, default_value = value
          self.min_value = min_value
          self.max_value = max_value
          c = []
          if min_value is not None:
              c.append('>=' + str(min_value))
          if max_value is not None:
              c.append('<=' + str(max_value))
          choices = ', '.join(c)
          super().__init__(description, choices, yielding)
          self.set_value(default_value)
  
      def validate_value(self, value: T.Any) -> int:
          if isinstance(value, str):
              value = self.toint(value)
          if not isinstance(value, int):
              raise MesonException('New value for integer option is not an integer.')
          if self.min_value is not None and value < self.min_value:
              raise MesonException('New value %d is less than minimum value %d.' % (value, self.min_value))
          if self.max_value is not None and value > self.max_value:
              raise MesonException('New value %d is more than maximum value %d.' % (value, self.max_value))
          return value
  
      def toint(self, valuestring: str) -> int:
          try:
              return int(valuestring)
          except ValueError:
              raise MesonException('Value string "%s" is not convertible to an integer.' % valuestring)
  
  class OctalInt(int):
      # NinjaBackend.get_user_option_args uses str() to converts it to a command line option
      # UserUmaskOption.toint() uses int(str, 8) to convert it to an integer
      # So we need to use oct instead of dec here if we do not want values to be misinterpreted.
      def __str__(self):
          return oct(int(self))
  
  class UserUmaskOption(UserIntegerOption, UserOption[T.Union[str, OctalInt]]):
      def __init__(self, description: str, value: T.Any, yielding: T.Optional[bool] = None):
          super().__init__(description, (0, 0o777, value), yielding)
          self.choices = ['preserve', '0000-0777']
  
      def printable_value(self) -> str:
          if self.value == 'preserve':
              return self.value
          return format(self.value, '04o')
  
      def validate_value(self, value: T.Any) -> T.Union[str, OctalInt]:
          if value is None or value == 'preserve':
              return 'preserve'
          return OctalInt(super().validate_value(value))
  
      def toint(self, valuestring: T.Union[str, OctalInt]) -> int:
          try:
              return int(valuestring, 8)
          except ValueError as e:
              raise MesonException(f'Invalid mode: {e}')
  
  class UserComboOption(UserOption[str]):
      def __init__(self, description: str, choices: T.List[str], value: T.Any, yielding: T.Optional[bool] = None):
          super().__init__(description, choices, yielding)
          if not isinstance(self.choices, list):
              raise MesonException('Combo choices must be an array.')
          for i in self.choices:
              if not isinstance(i, str):
                  raise MesonException('Combo choice elements must be strings.')
          self.set_value(value)
  
      def validate_value(self, value: T.Any) -> str:
          if value not in self.choices:
              if isinstance(value, bool):
                  _type = 'boolean'
              elif isinstance(value, (int, float)):
                  _type = 'number'
              else:
                  _type = 'string'
              optionsstring = ', '.join([f'"{item}"' for item in self.choices])
              raise MesonException('Value "{}" (of type "{}") for combo option "{}" is not one of the choices.'
                                   ' Possible choices are (as string): {}.'.format(
                                       value, _type, self.description, optionsstring))
          return value
  
  class UserArrayOption(UserOption[T.List[str]]):
      def __init__(self, description: str, value: T.Union[str, T.List[str]], split_args: bool = False, user_input: bool = False, allow_dups: bool = False, **kwargs: T.Any) -> None:
          super().__init__(description, kwargs.get('choices', []), yielding=kwargs.get('yielding', None))
          self.split_args = split_args
          self.allow_dups = allow_dups
          self.value = self.validate_value(value, user_input=user_input)
  
      def listify(self, value: T.Union[str, T.List[str]], user_input: bool = True) -> T.List[str]:
          # User input is for options defined on the command line (via -D
          # options). Users can put their input in as a comma separated
          # string, but for defining options in meson_options.txt the format
          # should match that of a combo
          if not user_input and isinstance(value, str) and not value.startswith('['):
              raise MesonException('Value does not define an array: ' + value)
  
          if isinstance(value, str):
              if value.startswith('['):
                  try:
                      newvalue = ast.literal_eval(value)
                  except ValueError:
                      raise MesonException(f'malformed option {value}')
              elif value == '':
                  newvalue = []
              else:
                  if self.split_args:
                      newvalue = split_args(value)
                  else:
                      newvalue = [v.strip() for v in value.split(',')]
          elif isinstance(value, list):
              newvalue = value
          else:
              raise MesonException(f'"{newvalue}" should be a string array, but it is not')
          return newvalue
  
      def validate_value(self, value: T.Union[str, T.List[str]], user_input: bool = True) -> T.List[str]:
          newvalue = self.listify(value, user_input)
  
          if not self.allow_dups and len(set(newvalue)) != len(newvalue):
              msg = 'Duplicated values in array option is deprecated. ' \
                    'This will become a hard error in the future.'
              mlog.deprecation(msg)
          for i in newvalue:
              if not isinstance(i, str):
                  raise MesonException(f'String array element "{newvalue!s}" is not a string.')
          if self.choices:
              bad = [x for x in newvalue if x not in self.choices]
              if bad:
                  raise MesonException('Options "{}" are not in allowed choices: "{}"'.format(
                      ', '.join(bad), ', '.join(self.choices)))
          return newvalue
  
      def extend_value(self, value: T.Union[str, T.List[str]]) -> None:
          """Extend the value with an additional value."""
          new = self.validate_value(value)
          self.set_value(self.value + new)
  
  
  class UserFeatureOption(UserComboOption):
      static_choices = ['enabled', 'disabled', 'auto']
  
      def __init__(self, description: str, value: T.Any, yielding: T.Optional[bool] = None):
          super().__init__(description, self.static_choices, value, yielding)
          self.name: T.Optional[str] = None  # TODO: Refactor options to all store their name
  
      def is_enabled(self) -> bool:
          return self.value == 'enabled'
  
      def is_disabled(self) -> bool:
          return self.value == 'disabled'
  
      def is_auto(self) -> bool:
          return self.value == 'auto'
  
  if T.TYPE_CHECKING:
      from .dependencies.detect import TV_DepID
  
  
  class DependencyCacheType(enum.Enum):
  
      OTHER = 0
      PKG_CONFIG = 1
      CMAKE = 2
  
      @classmethod
      def from_type(cls, dep: 'dependencies.Dependency') -> 'DependencyCacheType':
          from . import dependencies
          # As more types gain search overrides they'll need to be added here
          if isinstance(dep, dependencies.PkgConfigDependency):
              return cls.PKG_CONFIG
          if isinstance(dep, dependencies.CMakeDependency):
              return cls.CMAKE
          return cls.OTHER
  
  
  class DependencySubCache:
  
      def __init__(self, type_: DependencyCacheType):
          self.types = [type_]
          self.__cache: T.Dict[T.Tuple[str, ...], 'dependencies.Dependency'] = {}
  
      def __getitem__(self, key: T.Tuple[str, ...]) -> 'dependencies.Dependency':
          return self.__cache[key]
  
      def __setitem__(self, key: T.Tuple[str, ...], value: 'dependencies.Dependency') -> None:
          self.__cache[key] = value
  
      def __contains__(self, key: T.Tuple[str, ...]) -> bool:
          return key in self.__cache
  
      def values(self) -> T.Iterable['dependencies.Dependency']:
          return self.__cache.values()
  
  
  class DependencyCache:
  
      """Class that stores a cache of dependencies.
  
      This class is meant to encapsulate the fact that we need multiple keys to
      successfully lookup by providing a simple get/put interface.
      """
  
      def __init__(self, builtins: 'KeyedOptionDictType', for_machine: MachineChoice):
          self.__cache = OrderedDict()  # type: T.MutableMapping[TV_DepID, DependencySubCache]
          self.__builtins = builtins
          self.__pkg_conf_key = OptionKey('pkg_config_path', machine=for_machine)
          self.__cmake_key = OptionKey('cmake_prefix_path', machine=for_machine)
  
      def __calculate_subkey(self, type_: DependencyCacheType) -> T.Tuple[str, ...]:
          data: T.Dict[str, T.List[str]] = {
              DependencyCacheType.PKG_CONFIG: stringlistify(self.__builtins[self.__pkg_conf_key].value),
              DependencyCacheType.CMAKE: stringlistify(self.__builtins[self.__cmake_key].value),
              DependencyCacheType.OTHER: [],
          }
          assert type_ in data, 'Someone forgot to update subkey calculations for a new type'
          return tuple(data[type_])
  
      def __iter__(self) -> T.Iterator['TV_DepID']:
          return self.keys()
  
      def put(self, key: 'TV_DepID', dep: 'dependencies.Dependency') -> None:
          t = DependencyCacheType.from_type(dep)
          if key not in self.__cache:
              self.__cache[key] = DependencySubCache(t)
          subkey = self.__calculate_subkey(t)
          self.__cache[key][subkey] = dep
  
      def get(self, key: 'TV_DepID') -> T.Optional['dependencies.Dependency']:
          """Get a value from the cache.
  
          If there is no cache entry then None will be returned.
          """
          try:
              val = self.__cache[key]
          except KeyError:
              return None
  
          for t in val.types:
              subkey = self.__calculate_subkey(t)
              try:
                  return val[subkey]
              except KeyError:
                  pass
          return None
  
      def values(self) -> T.Iterator['dependencies.Dependency']:
          for c in self.__cache.values():
              yield from c.values()
  
      def keys(self) -> T.Iterator['TV_DepID']:
          return iter(self.__cache.keys())
  
      def items(self) -> T.Iterator[T.Tuple['TV_DepID', T.List['dependencies.Dependency']]]:
          for k, v in self.__cache.items():
              vs = []
              for t in v.types:
                  subkey = self.__calculate_subkey(t)
                  if subkey in v:
                      vs.append(v[subkey])
              yield k, vs
  
      def clear(self) -> None:
          self.__cache.clear()
  
  
  class CMakeStateCache:
      """Class that stores internal CMake compiler states.
  
      This cache is used to reduce the startup overhead of CMake by caching
      all internal CMake compiler variables.
      """
  
      def __init__(self) -> None:
          self.__cache: T.Dict[str, T.Dict[str, T.List[str]]] = {}
          self.cmake_cache: T.Dict[str, 'CMakeCacheEntry'] = {}
  
      def __iter__(self) -> T.Iterator[T.Tuple[str, T.Dict[str, T.List[str]]]]:
          return iter(self.__cache.items())
  
      def items(self) -> T.Iterator[T.Tuple[str, T.Dict[str, T.List[str]]]]:
          return iter(self.__cache.items())
  
      def update(self, language: str, variables: T.Dict[str, T.List[str]]):
          if language not in self.__cache:
              self.__cache[language] = {}
          self.__cache[language].update(variables)
  
      @property
      def languages(self) -> T.Set[str]:
          return set(self.__cache.keys())
  
  
  # Can't bind this near the class method it seems, sadly.
  _V = T.TypeVar('_V')
  
  # This class contains all data that must persist over multiple
  # invocations of Meson. It is roughly the same thing as
  # cmakecache.
  
  class CoreData:
  
      def __init__(self, options: argparse.Namespace, scratch_dir: str, meson_command: T.List[str]):
          self.lang_guids = {
              'default': '8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942',
              'c': '8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942',
              'cpp': '8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942',
              'test': '3AC096D0-A1C2-E12C-1390-A8335801FDAB',
              'directory': '2150E333-8FDC-42A3-9474-1A3956D46DE8',
          }
          self.test_guid = str(uuid.uuid4()).upper()
          self.regen_guid = str(uuid.uuid4()).upper()
          self.install_guid = str(uuid.uuid4()).upper()
          self.meson_command = meson_command
          self.target_guids = {}
          self.version = version
          self.options: 'KeyedOptionDictType' = {}
          self.cross_files = self.__load_config_files(options, scratch_dir, 'cross')
          self.compilers = PerMachine(OrderedDict(), OrderedDict())  # type: PerMachine[T.Dict[str, Compiler]]
  
          # Set of subprojects that have already been initialized once, this is
          # required to be stored and reloaded with the coredata, as we don't
          # want to overwrite options for such subprojects.
          self.initialized_subprojects: T.Set[str] = set()
  
          # For host == build configuraitons these caches should be the same.
          self.deps: PerMachine[DependencyCache] = PerMachineDefaultable.default(
              self.is_cross_build(),
              DependencyCache(self.options, MachineChoice.BUILD),
              DependencyCache(self.options, MachineChoice.HOST))
  
          self.compiler_check_cache: T.Dict['CompilerCheckCacheKey', 'CompileResult'] = OrderedDict()
  
          # CMake cache
          self.cmake_cache: PerMachine[CMakeStateCache] = PerMachine(CMakeStateCache(), CMakeStateCache())
  
          # Only to print a warning if it changes between Meson invocations.
          self.config_files = self.__load_config_files(options, scratch_dir, 'native')
          self.builtin_options_libdir_cross_fixup()
          self.init_builtins('')
  
      @staticmethod
      def __load_config_files(options: argparse.Namespace, scratch_dir: str, ftype: str) -> T.List[str]:
          # Need to try and make the passed filenames absolute because when the
          # files are parsed later we'll have chdir()d.
          if ftype == 'cross':
              filenames = options.cross_file
          else:
              filenames = options.native_file
  
          if not filenames:
              return []
  
          found_invalid = []  # type: T.List[str]
          missing = []        # type: T.List[str]
          real = []           # type: T.List[str]
          for i, f in enumerate(filenames):
              f = os.path.expanduser(os.path.expandvars(f))
              if os.path.exists(f):
                  if os.path.isfile(f):
                      real.append(os.path.abspath(f))
                      continue
                  elif os.path.isdir(f):
                      found_invalid.append(os.path.abspath(f))
                  else:
                      # in this case we've been passed some kind of pipe, copy
                      # the contents of that file into the meson private (scratch)
                      # directory so that it can be re-read when wiping/reconfiguring
                      copy = os.path.join(scratch_dir, f'{uuid.uuid4()}.{ftype}.ini')
                      with open(f, encoding='utf-8') as rf:
                          with open(copy, 'w', encoding='utf-8') as wf:
                              wf.write(rf.read())
                      real.append(copy)
  
                      # Also replace the command line argument, as the pipe
                      # probably won't exist on reconfigure
                      filenames[i] = copy
                      continue
              if sys.platform != 'win32':
                  paths = [
                      os.environ.get('XDG_DATA_HOME', os.path.expanduser('~/.local/share')),
                  ] + os.environ.get('XDG_DATA_DIRS', '/usr/local/share:/usr/share').split(':')
                  for path in paths:
                      path_to_try = os.path.join(path, 'meson', ftype, f)
                      if os.path.isfile(path_to_try):
                          real.append(path_to_try)
                          break
                  else:
                      missing.append(f)
              else:
                  missing.append(f)
  
          if missing:
              if found_invalid:
                  mlog.log('Found invalid candidates for', ftype, 'file:', *found_invalid)
              mlog.log('Could not find any valid candidate for', ftype, 'files:', *missing)
              raise MesonException(f'Cannot find specified {ftype} file: {f}')
          return real
  
      def builtin_options_libdir_cross_fixup(self):
          # By default set libdir to "lib" when cross compiling since
          # getting the "system default" is always wrong on multiarch
          # platforms as it gets a value like lib/x86_64-linux-gnu.
          if self.cross_files:
              BUILTIN_OPTIONS[OptionKey('libdir')].default = 'lib'
  
      def sanitize_prefix(self, prefix):
          prefix = os.path.expanduser(prefix)
          if not os.path.isabs(prefix):
              raise MesonException(f'prefix value {prefix!r} must be an absolute path')
          if prefix.endswith('/') or prefix.endswith('\\'):
              # On Windows we need to preserve the trailing slash if the
              # string is of type 'C:\' because 'C:' is not an absolute path.
              if len(prefix) == 3 and prefix[1] == ':':
                  pass
              # If prefix is a single character, preserve it since it is
              # the root directory.
              elif len(prefix) == 1:
                  pass
              else:
                  prefix = prefix[:-1]
          return prefix
  
      def sanitize_dir_option_value(self, prefix: str, option: OptionKey, value: T.Any) -> T.Any:
          '''
          If the option is an installation directory option and the value is an
          absolute path, check that it resides within prefix and return the value
          as a path relative to the prefix.
  
          This way everyone can do f.ex, get_option('libdir') and be sure to get
          the library directory relative to prefix.
  
          .as_posix() keeps the posix-like file separators Meson uses.
          '''
          try:
              value = PurePath(value)
          except TypeError:
              return value
          if option.name.endswith('dir') and value.is_absolute() and \
             option not in BULITIN_DIR_NOPREFIX_OPTIONS:
              # Value must be a subdir of the prefix
              # commonpath will always return a path in the native format, so we
              # must use pathlib.PurePath to do the same conversion before
              # comparing.
              msg = ('The value of the \'{!s}\' option is \'{!s}\' which must be a '
                     'subdir of the prefix {!r}.\nNote that if you pass a '
                     'relative path, it is assumed to be a subdir of prefix.')
              # os.path.commonpath doesn't understand case-insensitive filesystems,
              # but PurePath().relative_to() does.
              try:
                  value = value.relative_to(prefix)
              except ValueError:
                  raise MesonException(msg.format(option, value, prefix))
              if '..' in str(value):
                  raise MesonException(msg.format(option, value, prefix))
          return value.as_posix()
  
      def init_builtins(self, subproject: str) -> None:
          # Create builtin options with default values
          for key, opt in BUILTIN_OPTIONS.items():
              self.add_builtin_option(self.options, key.evolve(subproject=subproject), opt)
          for for_machine in iter(MachineChoice):
              for key, opt in BUILTIN_OPTIONS_PER_MACHINE.items():
                  self.add_builtin_option(self.options, key.evolve(subproject=subproject, machine=for_machine), opt)
  
      @staticmethod
      def add_builtin_option(opts_map: 'KeyedOptionDictType', key: OptionKey,
                             opt: 'BuiltinOption') -> None:
          if key.subproject:
              if opt.yielding:
                  # This option is global and not per-subproject
                  return
              value = opts_map[key.as_root()].value
          else:
              value = None
          opts_map[key] = opt.init_option(key, value, default_prefix())
  
      def init_backend_options(self, backend_name: str) -> None:
          if backend_name == 'ninja':
              self.options[OptionKey('backend_max_links')] = UserIntegerOption(
                  'Maximum number of linker processes to run or 0 for no '
                  'limit',
                  (0, None, 0))
          elif backend_name.startswith('vs'):
              self.options[OptionKey('backend_startup_project')] = UserStringOption(
                  'Default project to execute in Visual Studio',
                  '')
  
      def get_option(self, key: OptionKey) -> T.Union[str, int, bool, WrapMode]:
          try:
              v = self.options[key].value
              if key.name == 'wrap_mode':
                  return WrapMode[v]
              return v
          except KeyError:
              pass
  
          try:
              v = self.options[key.as_root()]
              if v.yielding:
                  if key.name == 'wrap_mode':
                      return WrapMode[v.value]
                  return v.value
          except KeyError:
              pass
  
          raise MesonException(f'Tried to get unknown builtin option {str(key)}')
  
      def set_option(self, key: OptionKey, value) -> None:
          if key.is_builtin():
              if key.name == 'prefix':
                  value = self.sanitize_prefix(value)
              else:
                  prefix = self.options[OptionKey('prefix')].value
                  value = self.sanitize_dir_option_value(prefix, key, value)
  
          try:
              opt = self.options[key]
          except KeyError:
              raise MesonException(f'Tried to set unknown builtin option {str(key)}')
  
          if opt.deprecated is True:
              mlog.deprecation(f'Option {key.name!r} is deprecated')
          elif isinstance(opt.deprecated, list):
              for v in opt.listify(value):
                  if v in opt.deprecated:
                      mlog.deprecation(f'Option {key.name!r} value {v!r} is deprecated')
          elif isinstance(opt.deprecated, dict):
              def replace(v):
                  newvalue = opt.deprecated.get(v)
                  if newvalue is not None:
                      mlog.deprecation(f'Option {key.name!r} value {v!r} is replaced by {newvalue!r}')
                      return newvalue
                  return v
              newvalue = [replace(v) for v in opt.listify(value)]
              value = ','.join(newvalue)
  
          opt.set_value(value)
  
          if key.name == 'buildtype':
              self._set_others_from_buildtype(value)
          elif key.name in {'wrap_mode', 'force_fallback_for'}:
              # We could have the system dependency cached for a dependency that
              # is now forced to use subproject fallback. We probably could have
              # more fine grained cache invalidation, but better be safe.
              self.clear_deps_cache()
  
      def clear_deps_cache(self):
          self.deps.host.clear()
          self.deps.build.clear()
  
      def get_nondefault_buildtype_args(self):
          result= []
          value = self.options[OptionKey('buildtype')].value
          if value == 'plain':
              opt = '0'
              debug = False
          elif value == 'debug':
              opt = '0'
              debug = True
          elif value == 'debugoptimized':
              opt = '2'
              debug = True
          elif value == 'release':
              opt = '3'
              debug = False
          elif value == 'minsize':
              opt = 's'
              debug = True
          else:
              assert value == 'custom'
              return []
          actual_opt = self.options[OptionKey('optimization')].value
          actual_debug = self.options[OptionKey('debug')].value
          if actual_opt != opt:
              result.append(('optimization', actual_opt, opt))
          if actual_debug != debug:
              result.append(('debug', actual_debug, debug))
          return result
  
      def _set_others_from_buildtype(self, value: str) -> None:
          if value == 'plain':
              opt = '0'
              debug = False
          elif value == 'debug':
              opt = '0'
              debug = True
          elif value == 'debugoptimized':
              opt = '2'
              debug = True
          elif value == 'release':
              opt = '3'
              debug = False
          elif value == 'minsize':
              opt = 's'
              debug = True
          else:
              assert value == 'custom'
              return
          self.options[OptionKey('optimization')].set_value(opt)
          self.options[OptionKey('debug')].set_value(debug)
  
      @staticmethod
      def is_per_machine_option(optname: OptionKey) -> bool:
          if optname.name in BUILTIN_OPTIONS_PER_MACHINE:
              return True
          return optname.lang is not None
  
      def validate_option_value(self, option_name: OptionKey, override_value):
          try:
              opt = self.options[option_name]
          except KeyError:
              raise MesonException(f'Tried to validate unknown option {str(option_name)}')
          try:
              return opt.validate_value(override_value)
          except MesonException as e:
              raise type(e)(('Validation failed for option %s: ' % option_name) + str(e)) \
                  .with_traceback(sys.exc_info()[2])
  
      def get_external_args(self, for_machine: MachineChoice, lang: str) -> T.Union[str, T.List[str]]:
          return self.options[OptionKey('args', machine=for_machine, lang=lang)].value
  
      def get_external_link_args(self, for_machine: MachineChoice, lang: str) -> T.Union[str, T.List[str]]:
          return self.options[OptionKey('link_args', machine=for_machine, lang=lang)].value
  
      def update_project_options(self, options: 'KeyedOptionDictType') -> None:
          for key, value in options.items():
              if not key.is_project():
                  continue
              if key not in self.options:
                  self.options[key] = value
                  continue
  
              oldval = self.options[key]
              if type(oldval) != type(value):
                  self.options[key] = value
              elif oldval.choices != value.choices:
                  # If the choices have changed, use the new value, but attempt
                  # to keep the old options. If they are not valid keep the new
                  # defaults but warn.
                  self.options[key] = value
                  try:
                      value.set_value(oldval.value)
                  except MesonException:
                      mlog.warning(f'Old value(s) of {key} are no longer valid, resetting to default ({value.value}).')
  
      def is_cross_build(self, when_building_for: MachineChoice = MachineChoice.HOST) -> bool:
          if when_building_for == MachineChoice.BUILD:
              return False
          return len(self.cross_files) > 0
  
      def copy_build_options_from_regular_ones(self) -> None:
          assert not self.is_cross_build()
          for k in BUILTIN_OPTIONS_PER_MACHINE:
              o = self.options[k]
              self.options[k.as_build()].set_value(o.value)
          for bk, bv in self.options.items():
              if bk.machine is MachineChoice.BUILD:
                  hk = bk.as_host()
                  try:
                      hv = self.options[hk]
                      bv.set_value(hv.value)
                  except KeyError:
                      continue
  
      def set_options(self, options: T.Dict[OptionKey, T.Any], subproject: str = '') -> None:
          if not self.is_cross_build():
              options = {k: v for k, v in options.items() if k.machine is not MachineChoice.BUILD}
          # Set prefix first because it's needed to sanitize other options
          pfk = OptionKey('prefix')
          if pfk in options:
              prefix = self.sanitize_prefix(options[pfk])
              self.options[OptionKey('prefix')].set_value(prefix)
              for key in BULITIN_DIR_NOPREFIX_OPTIONS:
                  if key not in options:
                      self.options[key].set_value(BUILTIN_OPTIONS[key].prefixed_default(key, prefix))
  
          unknown_options: T.List[OptionKey] = []
          for k, v in options.items():
              if k == pfk:
                  continue
              elif k in self.options:
                  self.set_option(k, v)
              elif k.machine != MachineChoice.BUILD:
                  unknown_options.append(k)
          if unknown_options:
              unknown_options_str = ', '.join(sorted(str(s) for s in unknown_options))
              sub = f'In subproject {subproject}: ' if subproject else ''
              raise MesonException(f'{sub}Unknown options: "{unknown_options_str}"')
  
          if not self.is_cross_build():
              self.copy_build_options_from_regular_ones()
  
      def set_default_options(self, default_options: T.MutableMapping[OptionKey, str], subproject: str, env: 'Environment') -> None:
          # Preserve order: if env.options has 'buildtype' it must come after
          # 'optimization' if it is in default_options.
          options: T.MutableMapping[OptionKey, T.Any]
          if not subproject:
              options = OrderedDict(default_options)
              options.update(env.options)
              env.options = options
  
          # Create a subset of options, keeping only project and builtin
          # options for this subproject.
          # Language and backend specific options will be set later when adding
          # languages and setting the backend (builtin options must be set first
          # to know which backend we'll use).
          options = OrderedDict()
  
          for k, v in chain(default_options.items(), env.options.items()):
              # If this is a subproject, don't use other subproject options
              if k.subproject and k.subproject != subproject:
                  continue
              # If the option is a builtin and is yielding then it's not allowed per subproject.
              #
              # Always test this using the HOST machine, as many builtin options
              # are not valid for the BUILD machine, but the yielding value does
              # not differ between them even when they are valid for both.
              if subproject and k.is_builtin() and self.options[k.evolve(subproject='', machine=MachineChoice.HOST)].yielding:
                  continue
              # Skip base, compiler, and backend options, they are handled when
              # adding languages and setting backend.
              if k.type in {OptionType.COMPILER, OptionType.BACKEND, OptionType.BASE}:
                  continue
              options[k] = v
  
          self.set_options(options, subproject=subproject)
  
      def add_compiler_options(self, options: 'KeyedOptionDictType', lang: str, for_machine: MachineChoice,
                               env: 'Environment') -> None:
          for k, o in options.items():
              value = env.options.get(k)
              if value is not None:
                  o.set_value(value)
              self.options.setdefault(k, o)
  
      def add_lang_args(self, lang: str, comp: T.Type['Compiler'],
                        for_machine: MachineChoice, env: 'Environment') -> None:
          """Add global language arguments that are needed before compiler/linker detection."""
          from .compilers import compilers
          # These options are all new at this point, because the compiler is
          # responsible for adding its own options, thus calling
          # `self.options.update()`` is perfectly safe.
          self.options.update(compilers.get_global_options(lang, comp, for_machine, env))
  
      def process_new_compiler(self, lang: str, comp: 'Compiler', env: 'Environment') -> None:
          from . import compilers
  
          self.compilers[comp.for_machine][lang] = comp
          self.add_compiler_options(comp.get_options(), lang, comp.for_machine, env)
  
          enabled_opts: T.List[OptionKey] = []
          for key in comp.base_options:
              if key in self.options:
                  continue
              oobj = compilers.base_options[key]
              if key in env.options:
                  oobj.set_value(env.options[key])
                  enabled_opts.append(key)
              self.options[key] = oobj
          self.emit_base_options_warnings(enabled_opts)
  
      def emit_base_options_warnings(self, enabled_opts: T.List[OptionKey]) -> None:
          if OptionKey('b_bitcode') in enabled_opts:
              mlog.warning('Base option \'b_bitcode\' is enabled, which is incompatible with many linker options. Incompatible options such as \'b_asneeded\' have been disabled.', fatal=False)
              mlog.warning('Please see https://mesonbuild.com/Builtin-options.html#Notes_about_Apple_Bitcode_support for more details.', fatal=False)
  
  class CmdLineFileParser(configparser.ConfigParser):
      def __init__(self) -> None:
          # We don't want ':' as key delimiter, otherwise it would break when
          # storing subproject options like "subproject:option=value"
          super().__init__(delimiters=['='], interpolation=None)
  
      def optionxform(self, option: str) -> str:
          # Don't call str.lower() on keys
          return option
  
  class MachineFileParser():
      def __init__(self, filenames: T.List[str]) -> None:
          self.parser = CmdLineFileParser()
          self.constants = {'True': True, 'False': False}
          self.sections = {}
  
          self.parser.read(filenames)
  
          # Parse [constants] first so they can be used in other sections
          if self.parser.has_section('constants'):
              self.constants.update(self._parse_section('constants'))
  
          for s in self.parser.sections():
              if s == 'constants':
                  continue
              self.sections[s] = self._parse_section(s)
  
      def _parse_section(self, s):
          self.scope = self.constants.copy()
          section = {}
          for entry, value in self.parser.items(s):
              if ' ' in entry or '\t' in entry or "'" in entry or '"' in entry:
                  raise EnvironmentException(f'Malformed variable name {entry!r} in machine file.')
              # Windows paths...
              value = value.replace('\\', '\\\\')
              try:
                  ast = mparser.Parser(value, 'machinefile').parse()
                  res = self._evaluate_statement(ast.lines[0])
              except MesonException:
                  raise EnvironmentException(f'Malformed value in machine file variable {entry!r}.')
              except KeyError as e:
                  raise EnvironmentException(f'Undefined constant {e.args[0]!r} in machine file variable {entry!r}.')
              section[entry] = res
              self.scope[entry] = res
          return section
  
      def _evaluate_statement(self, node):
          if isinstance(node, (mparser.StringNode)):
              return node.value
          elif isinstance(node, mparser.BooleanNode):
              return node.value
          elif isinstance(node, mparser.NumberNode):
              return node.value
          elif isinstance(node, mparser.ArrayNode):
              return [self._evaluate_statement(arg) for arg in node.args.arguments]
          elif isinstance(node, mparser.IdNode):
              return self.scope[node.value]
          elif isinstance(node, mparser.ArithmeticNode):
              l = self._evaluate_statement(node.left)
              r = self._evaluate_statement(node.right)
              if node.operation == 'add':
                  if (isinstance(l, str) and isinstance(r, str)) or \
                     (isinstance(l, list) and isinstance(r, list)):
                      return l + r
              elif node.operation == 'div':
                  if isinstance(l, str) and isinstance(r, str):
                      return os.path.join(l, r)
          raise EnvironmentException('Unsupported node type')
  
  def parse_machine_files(filenames):
      parser = MachineFileParser(filenames)
      return parser.sections
  
  def get_cmd_line_file(build_dir: str) -> str:
      return os.path.join(build_dir, 'meson-private', 'cmd_line.txt')
  
  def read_cmd_line_file(build_dir: str, options: argparse.Namespace) -> None:
      filename = get_cmd_line_file(build_dir)
      if not os.path.isfile(filename):
          return
  
      config = CmdLineFileParser()
      config.read(filename)
  
      # Do a copy because config is not really a dict. options.cmd_line_options
      # overrides values from the file.
      d = {OptionKey.from_string(k): v for k, v in config['options'].items()}
      d.update(options.cmd_line_options)
      options.cmd_line_options = d
  
      properties = config['properties']
      if not options.cross_file:
          options.cross_file = ast.literal_eval(properties.get('cross_file', '[]'))
      if not options.native_file:
          # This will be a string in the form: "['first', 'second', ...]", use
          # literal_eval to get it into the list of strings.
          options.native_file = ast.literal_eval(properties.get('native_file', '[]'))
  
  def write_cmd_line_file(build_dir: str, options: argparse.Namespace) -> None:
      filename = get_cmd_line_file(build_dir)
      config = CmdLineFileParser()
  
      properties = OrderedDict()
      if options.cross_file:
          properties['cross_file'] = options.cross_file
      if options.native_file:
          properties['native_file'] = options.native_file
  
      config['options'] = {str(k): str(v) for k, v in options.cmd_line_options.items()}
      config['properties'] = properties
      with open(filename, 'w', encoding='utf-8') as f:
          config.write(f)
  
  def update_cmd_line_file(build_dir: str, options: argparse.Namespace):
      filename = get_cmd_line_file(build_dir)
      config = CmdLineFileParser()
      config.read(filename)
      config['options'].update({str(k): str(v) for k, v in options.cmd_line_options.items()})
      with open(filename, 'w', encoding='utf-8') as f:
          config.write(f)
  
  def format_cmd_line_options(options: argparse.Namespace) -> str:
      cmdline = ['-D{}={}'.format(str(k), v) for k, v in options.cmd_line_options.items()]
      if options.cross_file:
          cmdline += [f'--cross-file {f}' for f in options.cross_file]
      if options.native_file:
          cmdline += [f'--native-file {f}' for f in options.native_file]
      return ' '.join([shlex.quote(x) for x in cmdline])
  
  def major_versions_differ(v1: str, v2: str) -> bool:
      v1_major, v1_minor = v1.rsplit('.', 1)
      v2_major, v2_minor = v2.rsplit('.', 1)
      # Major version differ, or one is development version but not the other.
      return v1_major != v2_major or ('99' in {v1_minor, v2_minor} and v1_minor != v2_minor)
  
  def load(build_dir: str) -> CoreData:
      filename = os.path.join(build_dir, 'meson-private', 'coredata.dat')
      load_fail_msg = f'Coredata file {filename!r} is corrupted. Try with a fresh build tree.'
      try:
          with open(filename, 'rb') as f:
              obj = pickle.load(f)
      except (pickle.UnpicklingError, EOFError):
          raise MesonException(load_fail_msg)
      except (ModuleNotFoundError, AttributeError):
          raise MesonException(
              f"Coredata file {filename!r} references functions or classes that don't "
              "exist. This probably means that it was generated with an old "
              "version of meson.")
      if not isinstance(obj, CoreData):
          raise MesonException(load_fail_msg)
      if major_versions_differ(obj.version, version):
          raise MesonVersionMismatchException(obj.version, version)
      return obj
  
  def save(obj: CoreData, build_dir: str) -> str:
      filename = os.path.join(build_dir, 'meson-private', 'coredata.dat')
      prev_filename = filename + '.prev'
      tempfilename = filename + '~'
      if major_versions_differ(obj.version, version):
          raise MesonException('Fatal version mismatch corruption.')
      if os.path.exists(filename):
          import shutil
          shutil.copyfile(filename, prev_filename)
      with open(tempfilename, 'wb') as f:
          pickle.dump(obj, f)
          f.flush()
          os.fsync(f.fileno())
      os.replace(tempfilename, filename)
      return filename
  
  
  def register_builtin_arguments(parser: argparse.ArgumentParser) -> None:
      for n, b in BUILTIN_OPTIONS.items():
          b.add_to_argparse(str(n), parser, '')
      for n, b in BUILTIN_OPTIONS_PER_MACHINE.items():
          b.add_to_argparse(str(n), parser, ' (just for host machine)')
          b.add_to_argparse(str(n.as_build()), parser, ' (just for build machine)')
      parser.add_argument('-D', action='append', dest='projectoptions', default=[], metavar="option",
                          help='Set the value of an option, can be used several times to set multiple options.')
  
  def create_options_dict(options: T.List[str], subproject: str = '') -> T.Dict[OptionKey, str]:
      result: T.OrderedDict[OptionKey, str] = OrderedDict()
      for o in options:
          try:
              (key, value) = o.split('=', 1)
          except ValueError:
              raise MesonException(f'Option {o!r} must have a value separated by equals sign.')
          k = OptionKey.from_string(key)
          if subproject:
              k = k.evolve(subproject=subproject)
          result[k] = value
      return result
  
  def parse_cmd_line_options(args: argparse.Namespace) -> None:
      args.cmd_line_options = create_options_dict(args.projectoptions)
  
      # Merge builtin options set with --option into the dict.
      for key in chain(
              BUILTIN_OPTIONS.keys(),
              (k.as_build() for k in BUILTIN_OPTIONS_PER_MACHINE.keys()),
              BUILTIN_OPTIONS_PER_MACHINE.keys(),
      ):
          name = str(key)
          value = getattr(args, name, None)
          if value is not None:
              if key in args.cmd_line_options:
                  cmdline_name = BuiltinOption.argparse_name_to_arg(name)
                  raise MesonException(
                      f'Got argument {name} as both -D{name} and {cmdline_name}. Pick one.')
              args.cmd_line_options[key] = value
              delattr(args, name)
  
  
  _U = T.TypeVar('_U', bound=UserOption[_T])
  
  class BuiltinOption(T.Generic[_T, _U]):
  
      """Class for a builtin option type.
  
      There are some cases that are not fully supported yet.
      """
  
      def __init__(self, opt_type: T.Type[_U], description: str, default: T.Any, yielding: bool = True, *,
                   choices: T.Any = None):
          self.opt_type = opt_type
          self.description = description
          self.default = default
          self.choices = choices
          self.yielding = yielding
  
      def init_option(self, name: 'OptionKey', value: T.Optional[T.Any], prefix: str) -> _U:
          """Create an instance of opt_type and return it."""
          if value is None:
              value = self.prefixed_default(name, prefix)
          keywords = {'yielding': self.yielding, 'value': value}
          if self.choices:
              keywords['choices'] = self.choices
          return self.opt_type(self.description, **keywords)
  
      def _argparse_action(self) -> T.Optional[str]:
          # If the type is a boolean, the presence of the argument in --foo form
          # is to enable it. Disabling happens by using -Dfoo=false, which is
          # parsed under `args.projectoptions` and does not hit this codepath.
          if isinstance(self.default, bool):
              return 'store_true'
          return None
  
      def _argparse_choices(self) -> T.Any:
          if self.opt_type is UserBooleanOption:
              return [True, False]
          elif self.opt_type is UserFeatureOption:
              return UserFeatureOption.static_choices
          return self.choices
  
      @staticmethod
      def argparse_name_to_arg(name: str) -> str:
          if name == 'warning_level':
              return '--warnlevel'
          else:
              return '--' + name.replace('_', '-')
  
      def prefixed_default(self, name: 'OptionKey', prefix: str = '') -> T.Any:
          if self.opt_type in [UserComboOption, UserIntegerOption]:
              return self.default
          try:
              return BULITIN_DIR_NOPREFIX_OPTIONS[name][prefix]
          except KeyError:
              pass
          return self.default
  
      def add_to_argparse(self, name: str, parser: argparse.ArgumentParser, help_suffix: str) -> None:
          kwargs = OrderedDict()
  
          c = self._argparse_choices()
          b = self._argparse_action()
          h = self.description
          if not b:
              h = '{} (default: {}).'.format(h.rstrip('.'), self.prefixed_default(name))
          else:
              kwargs['action'] = b
          if c and not b:
              kwargs['choices'] = c
          kwargs['default'] = argparse.SUPPRESS
          kwargs['dest'] = name
  
          cmdline_name = self.argparse_name_to_arg(name)
          parser.add_argument(cmdline_name, help=h + help_suffix, **kwargs)
  
  
  # Update `docs/markdown/Builtin-options.md` after changing the options below
  # Also update mesonlib._BUILTIN_NAMES. See the comment there for why this is required.
  BUILTIN_DIR_OPTIONS: 'KeyedOptionDictType' = OrderedDict([
      (OptionKey('prefix'),          BuiltinOption(UserStringOption, 'Installation prefix', default_prefix())),
      (OptionKey('bindir'),          BuiltinOption(UserStringOption, 'Executable directory', 'bin')),
      (OptionKey('datadir'),         BuiltinOption(UserStringOption, 'Data file directory', 'share')),
      (OptionKey('includedir'),      BuiltinOption(UserStringOption, 'Header file directory', 'include')),
      (OptionKey('infodir'),         BuiltinOption(UserStringOption, 'Info page directory', 'share/info')),
      (OptionKey('libdir'),          BuiltinOption(UserStringOption, 'Library directory', default_libdir())),
      (OptionKey('libexecdir'),      BuiltinOption(UserStringOption, 'Library executable directory', default_libexecdir())),
      (OptionKey('localedir'),       BuiltinOption(UserStringOption, 'Locale data directory', 'share/locale')),
      (OptionKey('localstatedir'),   BuiltinOption(UserStringOption, 'Localstate data directory', 'var')),
      (OptionKey('mandir'),          BuiltinOption(UserStringOption, 'Manual page directory', 'share/man')),
      (OptionKey('sbindir'),         BuiltinOption(UserStringOption, 'System executable directory', 'sbin')),
      (OptionKey('sharedstatedir'),  BuiltinOption(UserStringOption, 'Architecture-independent data directory', 'com')),
      (OptionKey('sysconfdir'),      BuiltinOption(UserStringOption, 'Sysconf data directory', 'etc')),
  ])
  
  BUILTIN_CORE_OPTIONS: 'KeyedOptionDictType' = OrderedDict([
      (OptionKey('auto_features'),   BuiltinOption(UserFeatureOption, "Override value of all 'auto' features", 'auto')),
      (OptionKey('backend'),         BuiltinOption(UserComboOption, 'Backend to use', 'ninja', choices=backendlist)),
      (OptionKey('buildtype'),       BuiltinOption(UserComboOption, 'Build type to use', 'debug',
                                                   choices=['plain', 'debug', 'debugoptimized', 'release', 'minsize', 'custom'])),
      (OptionKey('debug'),           BuiltinOption(UserBooleanOption, 'Debug', True)),
      (OptionKey('default_library'), BuiltinOption(UserComboOption, 'Default library type', 'shared', choices=['shared', 'static', 'both'],
                                                   yielding=False)),
      (OptionKey('errorlogs'),       BuiltinOption(UserBooleanOption, "Whether to print the logs from failing tests", True)),
      (OptionKey('install_umask'),   BuiltinOption(UserUmaskOption, 'Default umask to apply on permissions of installed files', '022')),
      (OptionKey('layout'),          BuiltinOption(UserComboOption, 'Build directory layout', 'mirror', choices=['mirror', 'flat'])),
      (OptionKey('optimization'),    BuiltinOption(UserComboOption, 'Optimization level', '0', choices=['0', 'g', '1', '2', '3', 's'])),
      (OptionKey('stdsplit'),        BuiltinOption(UserBooleanOption, 'Split stdout and stderr in test logs', True)),
      (OptionKey('strip'),           BuiltinOption(UserBooleanOption, 'Strip targets on install', False)),
      (OptionKey('unity'),           BuiltinOption(UserComboOption, 'Unity build', 'off', choices=['on', 'off', 'subprojects'])),
      (OptionKey('unity_size'),      BuiltinOption(UserIntegerOption, 'Unity block size', (2, None, 4))),
      (OptionKey('warning_level'),   BuiltinOption(UserComboOption, 'Compiler warning level to use', '1', choices=['0', '1', '2', '3'], yielding=False)),
      (OptionKey('werror'),          BuiltinOption(UserBooleanOption, 'Treat warnings as errors', False, yielding=False)),
      (OptionKey('wrap_mode'),       BuiltinOption(UserComboOption, 'Wrap mode', 'default', choices=['default', 'nofallback', 'nodownload', 'forcefallback', 'nopromote'])),
      (OptionKey('force_fallback_for'), BuiltinOption(UserArrayOption, 'Force fallback for those subprojects', [])),
  
      # Python module
      (OptionKey('platlibdir', module='python'),
       BuiltinOption(UserStringOption, 'Directory for site-specific, platform-specific files.', '')),
      (OptionKey('purelibdir', module='python'),
       BuiltinOption(UserStringOption, 'Directory for site-specific, non-platform-specific files.', '')),
  ])
  
  BUILTIN_OPTIONS = OrderedDict(chain(BUILTIN_DIR_OPTIONS.items(), BUILTIN_CORE_OPTIONS.items()))
  
  BUILTIN_OPTIONS_PER_MACHINE: 'KeyedOptionDictType' = OrderedDict([
      (OptionKey('pkg_config_path'), BuiltinOption(UserArrayOption, 'List of additional paths for pkg-config to search', [])),
      (OptionKey('cmake_prefix_path'), BuiltinOption(UserArrayOption, 'List of additional prefixes for cmake to search', [])),
  ])
  
  # Special prefix-dependent defaults for installation directories that reside in
  # a path outside of the prefix in FHS and common usage.
  BULITIN_DIR_NOPREFIX_OPTIONS: T.Dict[OptionKey, T.Dict[str, str]] = {
      OptionKey('sysconfdir'):     {'/usr': '/etc'},
      OptionKey('localstatedir'):  {'/usr': '/var',     '/usr/local': '/var/local'},
      OptionKey('sharedstatedir'): {'/usr': '/var/lib', '/usr/local': '/var/local/lib'},
      OptionKey('platlibdir', module='python'): {},
      OptionKey('purelibdir', module='python'): {},
  }
  
  FORBIDDEN_TARGET_NAMES = {'clean': None,
                            'clean-ctlist': None,
                            'clean-gcno': None,
                            'clean-gcda': None,
                            'coverage': None,
                            'coverage-text': None,
                            'coverage-xml': None,
                            'coverage-html': None,
                            'phony': None,
                            'PHONY': None,
                            'all': None,
                            'test': None,
                            'benchmark': None,
                            'install': None,
                            'uninstall': None,
                            'build.ninja': None,
                            'scan-build': None,
                            'reconfigure': None,
                            'dist': None,
                            'distcheck': None,
                            }
  