text: # Copyright 2012-2020 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.
  
  import itertools
  import os, platform, re, sys, shutil
  import typing as T
  import collections
  
  from . import coredata
  from . import mesonlib
  from .mesonlib import (
      MesonException, EnvironmentException, MachineChoice, Popen_safe, PerMachine,
      PerMachineDefaultable, PerThreeMachineDefaultable, split_args, quote_arg, OptionKey,
      search_version, MesonBugException
  )
  from . import mlog
  from .programs import (
      ExternalProgram, EmptyExternalProgram
  )
  
  from .envconfig import (
      BinaryTable, MachineInfo, Properties, known_cpu_families, CMakeVariables,
  )
  from . import compilers
  from .compilers import (
      Compiler,
      is_assembly,
      is_header,
      is_library,
      is_llvm_ir,
      is_object,
      is_source,
  )
  
  from functools import lru_cache
  from mesonbuild import envconfig
  
  if T.TYPE_CHECKING:
      from configparser import ConfigParser
  
      from .wrap.wrap import Resolver
  
  build_filename = 'meson.build'
  
  CompilersDict = T.Dict[str, Compiler]
  
  if T.TYPE_CHECKING:
      import argparse
  
  
  def _get_env_var(for_machine: MachineChoice, is_cross: bool, var_name: str) -> T.Optional[str]:
      """
      Returns the exact env var and the value.
      """
      candidates = PerMachine(
          # The prefixed build version takes priority, but if we are native
          # compiling we fall back on the unprefixed host version. This
          # allows native builds to never need to worry about the 'BUILD_*'
          # ones.
          ([var_name + '_FOR_BUILD'] if is_cross else [var_name]),
          # Always just the unprefixed host versions
          [var_name]
      )[for_machine]
      for var in candidates:
          value = os.environ.get(var)
          if value is not None:
              break
      else:
          formatted = ', '.join([f'{var!r}' for var in candidates])
          mlog.debug(f'None of {formatted} are defined in the environment, not changing global flags.')
          return None
      mlog.debug(f'Using {var!r} from environment with value: {value!r}')
      return value
  
  
  def detect_gcovr(min_version='3.3', log=False):
      gcovr_exe = 'gcovr'
      try:
          p, found = Popen_safe([gcovr_exe, '--version'])[0:2]
      except (FileNotFoundError, PermissionError):
          # Doesn't exist in PATH or isn't executable
          return None, None
      found = search_version(found)
      if p.returncode == 0 and mesonlib.version_compare(found, '>=' + min_version):
          if log:
              mlog.log('Found gcovr-{} at {}'.format(found, quote_arg(shutil.which(gcovr_exe))))
          return gcovr_exe, found
      return None, None
  
  def detect_llvm_cov():
      tools = get_llvm_tool_names('llvm-cov')
      for tool in tools:
          if mesonlib.exe_exists([tool, '--version']):
              return tool
      return None
  
  def find_coverage_tools() -> T.Tuple[T.Optional[str], T.Optional[str], T.Optional[str], T.Optional[str], T.Optional[str]]:
      gcovr_exe, gcovr_version = detect_gcovr()
  
      llvm_cov_exe = detect_llvm_cov()
  
      lcov_exe = 'lcov'
      genhtml_exe = 'genhtml'
  
      if not mesonlib.exe_exists([lcov_exe, '--version']):
          lcov_exe = None
      if not mesonlib.exe_exists([genhtml_exe, '--version']):
          genhtml_exe = None
  
      return gcovr_exe, gcovr_version, lcov_exe, genhtml_exe, llvm_cov_exe
  
  def detect_ninja(version: str = '1.8.2', log: bool = False) -> T.List[str]:
      r = detect_ninja_command_and_version(version, log)
      return r[0] if r else None
  
  def detect_ninja_command_and_version(version: str = '1.8.2', log: bool = False) -> T.Tuple[T.List[str], str]:
      env_ninja = os.environ.get('NINJA', None)
      for n in [env_ninja] if env_ninja else ['ninja', 'ninja-build', 'samu']:
          prog = ExternalProgram(n, silent=True)
          if not prog.found():
              continue
          try:
              p, found = Popen_safe(prog.command + ['--version'])[0:2]
          except (FileNotFoundError, PermissionError):
              # Doesn't exist in PATH or isn't executable
              continue
          found = found.strip()
          # Perhaps we should add a way for the caller to know the failure mode
          # (not found or too old)
          if p.returncode == 0 and mesonlib.version_compare(found, '>=' + version):
              if log:
                  name = os.path.basename(n)
                  if name.endswith('-' + found):
                      name = name[0:-1 - len(found)]
                  if name == 'ninja-build':
                      name = 'ninja'
                  if name == 'samu':
                      name = 'samurai'
                  mlog.log('Found {}-{} at {}'.format(name, found,
                           ' '.join([quote_arg(x) for x in prog.command])))
              return (prog.command, found)
  
  def get_llvm_tool_names(tool: str) -> T.List[str]:
      # Ordered list of possible suffixes of LLVM executables to try. Start with
      # base, then try newest back to oldest (3.5 is arbitrary), and finally the
      # devel version. Please note that the development snapshot in Debian does
      # not have a distinct name. Do not move it to the beginning of the list
      # unless it becomes a stable release.
      suffixes = [
          '', # base (no suffix)
          '-12',  '12',
          '-11',  '11',
          '-10',  '10',
          '-9',   '90',
          '-8',   '80',
          '-7',   '70',
          '-6.0', '60',
          '-5.0', '50',
          '-4.0', '40',
          '-3.9', '39',
          '-3.8', '38',
          '-3.7', '37',
          '-3.6', '36',
          '-3.5', '35',
          '-13',    # Debian development snapshot
          '-devel', # FreeBSD development snapshot
      ]
      names = []
      for suffix in suffixes:
          names.append(tool + suffix)
      return names
  
  def detect_scanbuild() -> T.List[str]:
      """ Look for scan-build binary on build platform
  
      First, if a SCANBUILD env variable has been provided, give it precedence
      on all platforms.
  
      For most platforms, scan-build is found is the PATH contains a binary
      named "scan-build". However, some distribution's package manager (FreeBSD)
      don't. For those, loop through a list of candidates to see if one is
      available.
  
      Return: a single-element list of the found scan-build binary ready to be
          passed to Popen()
      """
      exelist = []
      if 'SCANBUILD' in os.environ:
          exelist = split_args(os.environ['SCANBUILD'])
  
      else:
          tools = get_llvm_tool_names('scan-build')
          for tool in tools:
              if shutil.which(tool) is not None:
                  exelist = [shutil.which(tool)]
                  break
  
      if exelist:
          tool = exelist[0]
          if os.path.isfile(tool) and os.access(tool, os.X_OK):
              return [tool]
      return []
  
  def detect_clangformat() -> T.List[str]:
      """ Look for clang-format binary on build platform
  
      Do the same thing as detect_scanbuild to find clang-format except it
      currently does not check the environment variable.
  
      Return: a single-element list of the found clang-format binary ready to be
          passed to Popen()
      """
      tools = get_llvm_tool_names('clang-format')
      for tool in tools:
          path = shutil.which(tool)
          if path is not None:
              return [path]
      return []
  
  def detect_native_windows_arch():
      """
      The architecture of Windows itself: x86, amd64 or arm64
      """
      # These env variables are always available. See:
      # https://msdn.microsoft.com/en-us/library/aa384274(VS.85).aspx
      # https://blogs.msdn.microsoft.com/david.wang/2006/03/27/howto-detect-process-bitness/
      arch = os.environ.get('PROCESSOR_ARCHITEW6432', '').lower()
      if not arch:
          try:
              # If this doesn't exist, something is messing with the environment
              arch = os.environ['PROCESSOR_ARCHITECTURE'].lower()
          except KeyError:
              raise EnvironmentException('Unable to detect native OS architecture')
      return arch
  
  def detect_windows_arch(compilers: CompilersDict) -> str:
      """
      Detecting the 'native' architecture of Windows is not a trivial task. We
      cannot trust that the architecture that Python is built for is the 'native'
      one because you can run 32-bit apps on 64-bit Windows using WOW64 and
      people sometimes install 32-bit Python on 64-bit Windows.
  
      We also can't rely on the architecture of the OS itself, since it's
      perfectly normal to compile and run 32-bit applications on Windows as if
      they were native applications. It's a terrible experience to require the
      user to supply a cross-info file to compile 32-bit applications on 64-bit
      Windows. Thankfully, the only way to compile things with Visual Studio on
      Windows is by entering the 'msvc toolchain' environment, which can be
      easily detected.
  
      In the end, the sanest method is as follows:
      1. Check environment variables that are set by Windows and WOW64 to find out
         if this is x86 (possibly in WOW64), if so use that as our 'native'
         architecture.
      2. If the compiler toolchain target architecture is x86, use that as our
        'native' architecture.
      3. Otherwise, use the actual Windows architecture
  
      """
      os_arch = detect_native_windows_arch()
      if os_arch == 'x86':
          return os_arch
      # If we're on 64-bit Windows, 32-bit apps can be compiled without
      # cross-compilation. So if we're doing that, just set the native arch as
      # 32-bit and pretend like we're running under WOW64. Else, return the
      # actual Windows architecture that we deduced above.
      for compiler in compilers.values():
          if compiler.id == 'msvc' and (compiler.target == 'x86' or compiler.target == '80x86'):
              return 'x86'
          if compiler.id == 'clang-cl' and compiler.target == 'x86':
              return 'x86'
          if compiler.id == 'gcc' and compiler.has_builtin_define('__i386__'):
              return 'x86'
      return os_arch
  
  def any_compiler_has_define(compilers: CompilersDict, define):
      for c in compilers.values():
          try:
              if c.has_builtin_define(define):
                  return True
          except mesonlib.MesonException:
              # Ignore compilers that do not support has_builtin_define.
              pass
      return False
  
  def detect_cpu_family(compilers: CompilersDict) -> str:
      """
      Python is inconsistent in its platform module.
      It returns different values for the same cpu.
      For x86 it might return 'x86', 'i686' or somesuch.
      Do some canonicalization.
      """
      if mesonlib.is_windows():
          trial = detect_windows_arch(compilers)
      elif mesonlib.is_freebsd() or mesonlib.is_netbsd() or mesonlib.is_openbsd() or mesonlib.is_qnx() or mesonlib.is_aix():
          trial = platform.processor().lower()
      else:
          trial = platform.machine().lower()
      if trial.startswith('i') and trial.endswith('86'):
          trial = 'x86'
      elif trial == 'bepc':
          trial = 'x86'
      elif trial == 'arm64':
          trial = 'aarch64'
      elif trial.startswith('aarch64'):
          # This can be `aarch64_be`
          trial = 'aarch64'
      elif trial.startswith('arm') or trial.startswith('earm'):
          trial = 'arm'
      elif trial.startswith(('powerpc64', 'ppc64')):
          trial = 'ppc64'
      elif trial.startswith(('powerpc', 'ppc')) or trial in {'macppc', 'power macintosh'}:
          trial = 'ppc'
      elif trial in ('amd64', 'x64', 'i86pc'):
          trial = 'x86_64'
      elif trial in {'sun4u', 'sun4v'}:
          trial = 'sparc64'
      elif trial.startswith('mips'):
          if '64' not in trial:
              trial = 'mips'
          else:
              trial = 'mips64'
      elif trial in {'ip30', 'ip35'}:
          trial = 'mips64'
  
      # On Linux (and maybe others) there can be any mixture of 32/64 bit code in
      # the kernel, Python, system, 32-bit chroot on 64-bit host, etc. The only
      # reliable way to know is to check the compiler defines.
      if trial == 'x86_64':
          if any_compiler_has_define(compilers, '__i386__'):
              trial = 'x86'
      elif trial == 'aarch64':
          if any_compiler_has_define(compilers, '__arm__'):
              trial = 'arm'
      # Add more quirks here as bugs are reported. Keep in sync with detect_cpu()
      # below.
      elif trial == 'parisc64':
          # ATM there is no 64 bit userland for PA-RISC. Thus always
          # report it as 32 bit for simplicity.
          trial = 'parisc'
      elif trial == 'ppc':
          # AIX always returns powerpc, check here for 64-bit
          if any_compiler_has_define(compilers, '__64BIT__'):
              trial = 'ppc64'
  
      if trial not in known_cpu_families:
          mlog.warning(f'Unknown CPU family {trial!r}, please report this at '
                       'https://github.com/mesonbuild/meson/issues/new with the '
                       'output of `uname -a` and `cat /proc/cpuinfo`')
  
      return trial
  
  def detect_cpu(compilers: CompilersDict) -> str:
      if mesonlib.is_windows():
          trial = detect_windows_arch(compilers)
      elif mesonlib.is_freebsd() or mesonlib.is_netbsd() or mesonlib.is_openbsd() or mesonlib.is_aix():
          trial = platform.processor().lower()
      else:
          trial = platform.machine().lower()
  
      if trial in ('amd64', 'x64', 'i86pc'):
          trial = 'x86_64'
      if trial == 'x86_64':
          # Same check as above for cpu_family
          if any_compiler_has_define(compilers, '__i386__'):
              trial = 'i686' # All 64 bit cpus have at least this level of x86 support.
      elif trial.startswith('aarch64'):
          # Same check as above for cpu_family
          if any_compiler_has_define(compilers, '__arm__'):
              trial = 'arm'
          else:
              # for aarch64_be
              trial = 'aarch64'
      elif trial.startswith('earm'):
          trial = 'arm'
      elif trial == 'e2k':
          # Make more precise CPU detection for Elbrus platform.
          trial = platform.processor().lower()
      elif trial.startswith('mips'):
          if '64' not in trial:
              trial = 'mips'
          else:
              trial = 'mips64'
      elif trial == 'ppc':
          # AIX always returns powerpc, check here for 64-bit
          if any_compiler_has_define(compilers, '__64BIT__'):
              trial = 'ppc64'
  
      # Add more quirks here as bugs are reported. Keep in sync with
      # detect_cpu_family() above.
      return trial
  
  def detect_system() -> str:
      if sys.platform == 'cygwin':
          return 'cygwin'
      return platform.system().lower()
  
  def detect_msys2_arch() -> T.Optional[str]:
      return os.environ.get('MSYSTEM_CARCH', None)
  
  def detect_machine_info(compilers: T.Optional[CompilersDict] = None) -> MachineInfo:
      """Detect the machine we're running on
  
      If compilers are not provided, we cannot know as much. None out those
      fields to avoid accidentally depending on partial knowledge. The
      underlying ''detect_*'' method can be called to explicitly use the
      partial information.
      """
      return MachineInfo(
          detect_system(),
          detect_cpu_family(compilers) if compilers is not None else None,
          detect_cpu(compilers) if compilers is not None else None,
          sys.byteorder)
  
  # TODO make this compare two `MachineInfo`s purely. How important is the
  # `detect_cpu_family({})` distinction? It is the one impediment to that.
  def machine_info_can_run(machine_info: MachineInfo):
      """Whether we can run binaries for this machine on the current machine.
  
      Can almost always run 32-bit binaries on 64-bit natively if the host
      and build systems are the same. We don't pass any compilers to
      detect_cpu_family() here because we always want to know the OS
      architecture, not what the compiler environment tells us.
      """
      if machine_info.system != detect_system():
          return False
      true_build_cpu_family = detect_cpu_family({})
      return \
          (machine_info.cpu_family == true_build_cpu_family) or \
          ((true_build_cpu_family == 'x86_64') and (machine_info.cpu_family == 'x86')) or \
          ((true_build_cpu_family == 'aarch64') and (machine_info.cpu_family == 'arm'))
  
  class Environment:
      private_dir = 'meson-private'
      log_dir = 'meson-logs'
      info_dir = 'meson-info'
  
      def __init__(self, source_dir: T.Optional[str], build_dir: T.Optional[str], options: 'argparse.Namespace') -> None:
          self.source_dir = source_dir
          self.build_dir = build_dir
          # Do not try to create build directories when build_dir is none.
          # This reduced mode is used by the --buildoptions introspector
          if build_dir is not None:
              self.scratch_dir = os.path.join(build_dir, Environment.private_dir)
              self.log_dir = os.path.join(build_dir, Environment.log_dir)
              self.info_dir = os.path.join(build_dir, Environment.info_dir)
              os.makedirs(self.scratch_dir, exist_ok=True)
              os.makedirs(self.log_dir, exist_ok=True)
              os.makedirs(self.info_dir, exist_ok=True)
              try:
                  self.coredata = coredata.load(self.get_build_dir())  # type: coredata.CoreData
                  self.first_invocation = False
              except FileNotFoundError:
                  self.create_new_coredata(options)
              except coredata.MesonVersionMismatchException as e:
                  # This is routine, but tell the user the update happened
                  mlog.log('Regenerating configuration from scratch:', str(e))
                  coredata.read_cmd_line_file(self.build_dir, options)
                  self.create_new_coredata(options)
              except MesonException as e:
                  # If we stored previous command line options, we can recover from
                  # a broken/outdated coredata.
                  if os.path.isfile(coredata.get_cmd_line_file(self.build_dir)):
                      mlog.warning('Regenerating configuration from scratch.')
                      mlog.log('Reason:', mlog.red(str(e)))
                      coredata.read_cmd_line_file(self.build_dir, options)
                      self.create_new_coredata(options)
                  else:
                      raise e
          else:
              # Just create a fresh coredata in this case
              self.scratch_dir = ''
              self.create_new_coredata(options)
  
          ## locally bind some unfrozen configuration
  
          # Stores machine infos, the only *three* machine one because we have a
          # target machine info on for the user (Meson never cares about the
          # target machine.)
          machines: PerThreeMachineDefaultable[MachineInfo] = PerThreeMachineDefaultable()
  
          # Similar to coredata.compilers, but lower level in that there is no
          # meta data, only names/paths.
          binaries = PerMachineDefaultable()  # type: PerMachineDefaultable[BinaryTable]
  
          # Misc other properties about each machine.
          properties = PerMachineDefaultable()  # type: PerMachineDefaultable[Properties]
  
          # CMake toolchain variables
          cmakevars = PerMachineDefaultable()  # type: PerMachineDefaultable[CMakeVariables]
  
          ## Setup build machine defaults
  
          # Will be fully initialized later using compilers later.
          machines.build = detect_machine_info()
  
          # Just uses hard-coded defaults and environment variables. Might be
          # overwritten by a native file.
          binaries.build = BinaryTable()
          properties.build = Properties()
  
          # Options with the key parsed into an OptionKey type.
          #
          # Note that order matters because of 'buildtype', if it is after
          # 'optimization' and 'debug' keys, it override them.
          self.options: T.MutableMapping[OptionKey, T.Union[str, T.List[str]]] = collections.OrderedDict()
  
          ## Read in native file(s) to override build machine configuration
  
          if self.coredata.config_files is not None:
              config = coredata.parse_machine_files(self.coredata.config_files)
              binaries.build = BinaryTable(config.get('binaries', {}))
              properties.build = Properties(config.get('properties', {}))
              cmakevars.build = CMakeVariables(config.get('cmake', {}))
              self._load_machine_file_options(
                  config, properties.build,
                  MachineChoice.BUILD if self.coredata.cross_files else MachineChoice.HOST)
  
          ## Read in cross file(s) to override host machine configuration
  
          if self.coredata.cross_files:
              config = coredata.parse_machine_files(self.coredata.cross_files)
              properties.host = Properties(config.get('properties', {}))
              binaries.host = BinaryTable(config.get('binaries', {}))
              cmakevars.host = CMakeVariables(config.get('cmake', {}))
              if 'host_machine' in config:
                  machines.host = MachineInfo.from_literal(config['host_machine'])
              if 'target_machine' in config:
                  machines.target = MachineInfo.from_literal(config['target_machine'])
              # Keep only per machine options from the native file. The cross
              # file takes precedence over all other options.
              for key, value in list(self.options.items()):
                  if self.coredata.is_per_machine_option(key):
                      self.options[key.as_build()] = value
              self._load_machine_file_options(config, properties.host, MachineChoice.HOST)
  
          ## "freeze" now initialized configuration, and "save" to the class.
  
          self.machines = machines.default_missing()
          self.binaries = binaries.default_missing()
          self.properties = properties.default_missing()
          self.cmakevars = cmakevars.default_missing()
  
          # Command line options override those from cross/native files
          self.options.update(options.cmd_line_options)
  
          # Take default value from env if not set in cross/native files or command line.
          self._set_default_options_from_env()
          self._set_default_binaries_from_env()
          self._set_default_properties_from_env()
  
          # Warn if the user is using two different ways of setting build-type
          # options that override each other
          bt = OptionKey('buildtype')
          db = OptionKey('debug')
          op = OptionKey('optimization')
          if bt in self.options and (db in self.options or op in self.options):
              mlog.warning('Recommend using either -Dbuildtype or -Doptimization + -Ddebug. '
                           'Using both is redundant since they override each other. '
                           'See: https://mesonbuild.com/Builtin-options.html#build-type-options')
  
          exe_wrapper = self.lookup_binary_entry(MachineChoice.HOST, 'exe_wrapper')
          if exe_wrapper is not None:
              self.exe_wrapper = ExternalProgram.from_bin_list(self, MachineChoice.HOST, 'exe_wrapper')
          else:
              self.exe_wrapper = None
  
          self.default_cmake = ['cmake']
          self.default_pkgconfig = ['pkg-config']
          self.wrap_resolver: T.Optional['Resolver'] = None
  
      def _load_machine_file_options(self, config: 'ConfigParser', properties: Properties, machine: MachineChoice) -> None:
          """Read the contents of a Machine file and put it in the options store."""
  
          # Look for any options in the deprecated paths section, warn about
          # those, then assign them. They will be overwritten by the ones in the
          # "built-in options" section if they're in both sections.
          paths = config.get('paths')
          if paths:
              mlog.deprecation('The [paths] section is deprecated, use the [built-in options] section instead.')
              for k, v in paths.items():
                  self.options[OptionKey.from_string(k).evolve(machine=machine)] = v
  
          # Next look for compiler options in the "properties" section, this is
          # also deprecated, and these will also be overwritten by the "built-in
          # options" section. We need to remove these from this section, as well.
          deprecated_properties: T.Set[str] = set()
          for lang in compilers.all_languages:
              deprecated_properties.add(lang + '_args')
              deprecated_properties.add(lang + '_link_args')
          for k, v in properties.properties.copy().items():
              if k in deprecated_properties:
                  mlog.deprecation(f'{k} in the [properties] section of the machine file is deprecated, use the [built-in options] section.')
                  self.options[OptionKey.from_string(k).evolve(machine=machine)] = v
                  del properties.properties[k]
  
          for section, values in config.items():
              if ':' in section:
                  subproject, section = section.split(':')
              else:
                  subproject = ''
              if section == 'built-in options':
                  for k, v in values.items():
                      key = OptionKey.from_string(k)
                      # If we're in the cross file, and there is a `build.foo` warn about that. Later we'll remove it.
                      if machine is MachineChoice.HOST and key.machine is not machine:
                          mlog.deprecation('Setting build machine options in cross files, please use a native file instead, this will be removed in meson 0.60', once=True)
                      if key.subproject:
                          raise MesonException('Do not set subproject options in [built-in options] section, use [subproject:built-in options] instead.')
                      self.options[key.evolve(subproject=subproject, machine=machine)] = v
              elif section == 'project options' and machine is MachineChoice.HOST:
                  # Project options are only for the host machine, we don't want
                  # to read these from the native file
                  for k, v in values.items():
                      # Project options are always for the host machine
                      key = OptionKey.from_string(k)
                      if key.subproject:
                          raise MesonException('Do not set subproject options in [built-in options] section, use [subproject:built-in options] instead.')
                      self.options[key.evolve(subproject=subproject)] = v
  
      def _set_default_options_from_env(self) -> None:
          opts: T.List[T.Tuple[str, str]] = (
              [(v, f'{k}_args') for k, v in compilers.compilers.CFLAGS_MAPPING.items()] +
              [
                  ('PKG_CONFIG_PATH', 'pkg_config_path'),
                  ('CMAKE_PREFIX_PATH', 'cmake_prefix_path'),
                  ('LDFLAGS', 'ldflags'),
                  ('CPPFLAGS', 'cppflags'),
              ]
          )
  
          env_opts: T.DefaultDict[OptionKey, T.List[str]] = collections.defaultdict(list)
  
          for (evar, keyname), for_machine in itertools.product(opts, MachineChoice):
              p_env = _get_env_var(for_machine, self.is_cross_build(), evar)
              if p_env is not None:
                  # these may contain duplicates, which must be removed, else
                  # a duplicates-in-array-option warning arises.
                  if keyname == 'cmake_prefix_path':
                      if self.machines[for_machine].is_windows():
                          # Cannot split on ':' on Windows because its in the drive letter
                          _p_env = p_env.split(os.pathsep)
                      else:
                          # https://github.com/mesonbuild/meson/issues/7294
                          _p_env = re.split(r':|;', p_env)
                      p_list = list(mesonlib.OrderedSet(_p_env))
                  elif keyname == 'pkg_config_path':
                      p_list = list(mesonlib.OrderedSet(p_env.split(':')))
                  else:
                      p_list = split_args(p_env)
                  p_list = [e for e in p_list if e]  # filter out any empty elements
  
                  # Take env vars only on first invocation, if the env changes when
                  # reconfiguring it gets ignored.
                  # FIXME: We should remember if we took the value from env to warn
                  # if it changes on future invocations.
                  if self.first_invocation:
                      if keyname == 'ldflags':
                          key = OptionKey('link_args', machine=for_machine, lang='c')  # needs a language to initialize properly
                          for lang in compilers.compilers.LANGUAGES_USING_LDFLAGS:
                              key = key.evolve(lang=lang)
                              env_opts[key].extend(p_list)
                      elif keyname == 'cppflags':
                          key = OptionKey('env_args', machine=for_machine, lang='c')
                          for lang in compilers.compilers.LANGUAGES_USING_CPPFLAGS:
                              key = key.evolve(lang=lang)
                              env_opts[key].extend(p_list)
                      else:
                          key = OptionKey.from_string(keyname).evolve(machine=for_machine)
                          if evar in compilers.compilers.CFLAGS_MAPPING.values():
                              # If this is an environment variable, we have to
                              # store it separately until the compiler is
                              # instantiated, as we don't know whether the
                              # compiler will want to use these arguments at link
                              # time and compile time (instead of just at compile
                              # time) until we're instantiating that `Compiler`
                              # object. This is required so that passing
                              # `-Dc_args=` on the command line and `$CFLAGS`
                              # have subtely different behavior. `$CFLAGS` will be
                              # added to the linker command line if the compiler
                              # acts as a linker driver, `-Dc_args` will not.
                              #
                              # We still use the original key as the base here, as
                              # we want to inhert the machine and the compiler
                              # language
                              key = key.evolve('env_args')
                          env_opts[key].extend(p_list)
  
          # Only store options that are not already in self.options,
          # otherwise we'd override the machine files
          for k, v in env_opts.items():
              if k not in self.options:
                  self.options[k] = v
  
      def _set_default_binaries_from_env(self) -> None:
          """Set default binaries from the environment.
  
          For example, pkg-config can be set via PKG_CONFIG, or in the machine
          file. We want to set the default to the env variable.
          """
          opts = itertools.chain(envconfig.DEPRECATED_ENV_PROG_MAP.items(),
                                 envconfig.ENV_VAR_PROG_MAP.items())
  
          for (name, evar), for_machine in itertools.product(opts, MachineChoice):
              p_env = _get_env_var(for_machine, self.is_cross_build(), evar)
              if p_env is not None:
                  self.binaries[for_machine].binaries.setdefault(name, mesonlib.split_args(p_env))
  
      def _set_default_properties_from_env(self) -> None:
          """Properties which can also be set from the environment."""
          # name, evar, split
          opts: T.List[T.Tuple[str, T.List[str], bool]] = [
              ('boost_includedir', ['BOOST_INCLUDEDIR'], False),
              ('boost_librarydir', ['BOOST_LIBRARYDIR'], False),
              ('boost_root', ['BOOST_ROOT', 'BOOSTROOT'], True),
              ('java_home', ['JAVA_HOME'], False),
          ]
  
          for (name, evars, split), for_machine in itertools.product(opts, MachineChoice):
              for evar in evars:
                  p_env = _get_env_var(for_machine, self.is_cross_build(), evar)
                  if p_env is not None:
                      if split:
                          self.properties[for_machine].properties.setdefault(name, p_env.split(os.pathsep))
                      else:
                          self.properties[for_machine].properties.setdefault(name, p_env)
                      break
  
      def create_new_coredata(self, options: 'argparse.Namespace') -> None:
          # WARNING: Don't use any values from coredata in __init__. It gets
          # re-initialized with project options by the interpreter during
          # build file parsing.
          # meson_command is used by the regenchecker script, which runs meson
          self.coredata = coredata.CoreData(options, self.scratch_dir, mesonlib.get_meson_command())
          self.first_invocation = True
  
      def is_cross_build(self, when_building_for: MachineChoice = MachineChoice.HOST) -> bool:
          return self.coredata.is_cross_build(when_building_for)
  
      def dump_coredata(self) -> str:
          return coredata.save(self.coredata, self.get_build_dir())
  
      def get_log_dir(self) -> str:
          return self.log_dir
  
      def get_coredata(self) -> coredata.CoreData:
          return self.coredata
  
      @staticmethod
      def get_build_command(unbuffered: bool = False) -> T.List[str]:
          cmd = mesonlib.get_meson_command()
          if cmd is None:
              raise MesonBugException('No command?')
          cmd = cmd.copy()
          if unbuffered and 'python' in os.path.basename(cmd[0]):
              cmd.insert(1, '-u')
          return cmd
  
      def is_header(self, fname: 'mesonlib.FileOrString') -> bool:
          return is_header(fname)
  
      def is_source(self, fname: 'mesonlib.FileOrString') -> bool:
          return is_source(fname)
  
      def is_assembly(self, fname: 'mesonlib.FileOrString') -> bool:
          return is_assembly(fname)
  
      def is_llvm_ir(self, fname: 'mesonlib.FileOrString') -> bool:
          return is_llvm_ir(fname)
  
      def is_object(self, fname: 'mesonlib.FileOrString') -> bool:
          return is_object(fname)
  
      @lru_cache(maxsize=None)
      def is_library(self, fname):
          return is_library(fname)
  
      def lookup_binary_entry(self, for_machine: MachineChoice, name: str) -> T.Optional[T.List[str]]:
          return self.binaries[for_machine].lookup_entry(name)
  
      def get_scratch_dir(self) -> str:
          return self.scratch_dir
  
      def get_source_dir(self) -> str:
          return self.source_dir
  
      def get_build_dir(self) -> str:
          return self.build_dir
  
      def get_import_lib_dir(self) -> str:
          "Install dir for the import library (library used for linking)"
          return self.get_libdir()
  
      def get_shared_module_dir(self) -> str:
          "Install dir for shared modules that are loaded at runtime"
          return self.get_libdir()
  
      def get_shared_lib_dir(self) -> str:
          "Install dir for the shared library"
          m = self.machines.host
          # Windows has no RPATH or similar, so DLLs must be next to EXEs.
          if m.is_windows() or m.is_cygwin():
              return self.get_bindir()
          return self.get_libdir()
  
      def get_static_lib_dir(self) -> str:
          "Install dir for the static library"
          return self.get_libdir()
  
      def get_prefix(self) -> str:
          return self.coredata.get_option(OptionKey('prefix'))
  
      def get_libdir(self) -> str:
          return self.coredata.get_option(OptionKey('libdir'))
  
      def get_libexecdir(self) -> str:
          return self.coredata.get_option(OptionKey('libexecdir'))
  
      def get_bindir(self) -> str:
          return self.coredata.get_option(OptionKey('bindir'))
  
      def get_includedir(self) -> str:
          return self.coredata.get_option(OptionKey('includedir'))
  
      def get_mandir(self) -> str:
          return self.coredata.get_option(OptionKey('mandir'))
  
      def get_datadir(self) -> str:
          return self.coredata.get_option(OptionKey('datadir'))
  
      def get_compiler_system_dirs(self, for_machine: MachineChoice):
          for comp in self.coredata.compilers[for_machine].values():
              if isinstance(comp, compilers.ClangCompiler):
                  index = 1
                  break
              elif isinstance(comp, compilers.GnuCompiler):
                  index = 2
                  break
          else:
              # This option is only supported by gcc and clang. If we don't get a
              # GCC or Clang compiler return and empty list.
              return []
  
          p, out, _ = Popen_safe(comp.get_exelist() + ['-print-search-dirs'])
          if p.returncode != 0:
              raise mesonlib.MesonException('Could not calculate system search dirs')
          out = out.split('\n')[index].lstrip('libraries: =').split(':')
          return [os.path.normpath(p) for p in out]
  
      def need_exe_wrapper(self, for_machine: MachineChoice = MachineChoice.HOST):
          value = self.properties[for_machine].get('needs_exe_wrapper', None)
          if value is not None:
              return value
          return not machine_info_can_run(self.machines[for_machine])
  
      def get_exe_wrapper(self) -> ExternalProgram:
          if not self.need_exe_wrapper():
              return EmptyExternalProgram()
          return self.exe_wrapper
  