files: # Copyright 2013-2019 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.
  
  # This file contains the detection logic for external dependencies useful for
  # development purposes, such as testing, debugging, etc..
  
  import functools
  import glob
  import os
  import re
  
  from .. import mesonlib, mlog
  from ..mesonlib import version_compare, stringlistify, extract_as_list, MachineChoice
  from ..environment import get_llvm_tool_names
  from .base import (
      DependencyException, DependencyMethods, ExternalDependency, PkgConfigDependency,
      strip_system_libdirs, ConfigToolDependency, CMakeDependency, HasNativeKwarg
  )
  from .misc import ThreadDependency
  
  from typing import List, Tuple
  
  
  def get_shared_library_suffix(environment, for_machine: MachineChoice):
      """This is only gauranteed to work for languages that compile to machine
      code, not for languages like C# that use a bytecode and always end in .dll
      """
      m = environment.machines[for_machine]
      if m.is_windows():
          return '.dll'
      elif m.is_darwin():
          return '.dylib'
      return '.so'
  
  
  class GTestDependency(ExternalDependency):
      def __init__(self, environment, kwargs):
          super().__init__('gtest', environment, 'cpp', kwargs)
          self.main = kwargs.get('main', False)
          self.src_dirs = ['/usr/src/gtest/src', '/usr/src/googletest/googletest/src']
          self.detect()
          self._add_sub_dependency(ThreadDependency, environment, kwargs)
  
      def detect(self):
          gtest_detect = self.clib_compiler.find_library("gtest", self.env, [])
          gtest_main_detect = self.clib_compiler.find_library("gtest_main", self.env, [])
          if gtest_detect and (not self.main or gtest_main_detect):
              self.is_found = True
              self.compile_args = []
              self.link_args = gtest_detect
              if self.main:
                  self.link_args += gtest_main_detect
              self.sources = []
              self.prebuilt = True
          elif self.detect_srcdir():
              self.is_found = True
              self.compile_args = ['-I' + d for d in self.src_include_dirs]
              self.link_args = []
              if self.main:
                  self.sources = [self.all_src, self.main_src]
              else:
                  self.sources = [self.all_src]
              self.prebuilt = False
          else:
              self.is_found = False
  
      def detect_srcdir(self):
          for s in self.src_dirs:
              if os.path.exists(s):
                  self.src_dir = s
                  self.all_src = mesonlib.File.from_absolute_file(
                      os.path.join(self.src_dir, 'gtest-all.cc'))
                  self.main_src = mesonlib.File.from_absolute_file(
                      os.path.join(self.src_dir, 'gtest_main.cc'))
                  self.src_include_dirs = [os.path.normpath(os.path.join(self.src_dir, '..')),
                                           os.path.normpath(os.path.join(self.src_dir, '../include')),
                                           ]
                  return True
          return False
  
      def log_info(self):
          if self.prebuilt:
              return 'prebuilt'
          else:
              return 'building self'
  
      def log_tried(self):
          return 'system'
  
      @classmethod
      def _factory(cls, environment, kwargs):
          methods = cls._process_method_kw(kwargs)
          candidates = []
  
          if DependencyMethods.PKGCONFIG in methods:
              pcname = 'gtest_main' if kwargs.get('main', False) else 'gtest'
              candidates.append(functools.partial(PkgConfigDependency, pcname, environment, kwargs))
  
          if DependencyMethods.SYSTEM in methods:
              candidates.append(functools.partial(GTestDependency, environment, kwargs))
  
          return candidates
  
      @staticmethod
      def get_methods():
          return [DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM]
  
  
  class GMockDependency(ExternalDependency):
      def __init__(self, environment, kwargs):
          super().__init__('gmock', environment, 'cpp', kwargs)
          self.main = kwargs.get('main', False)
          self._add_sub_dependency(ThreadDependency, environment, kwargs)
  
          # If we are getting main() from GMock, we definitely
          # want to avoid linking in main() from GTest
          gtest_kwargs = kwargs.copy()
          if self.main:
              gtest_kwargs['main'] = False
  
          # GMock without GTest is pretty much useless
          # this also mimics the structure given in WrapDB,
          # where GMock always pulls in GTest
          gtest_dep = GTestDependency(environment, gtest_kwargs)
          if not gtest_dep.is_found:
              self.is_found = False
              return
          self.ext_deps.append(gtest_dep)
  
          # GMock may be a library or just source.
          # Work with both.
          gmock_detect = self.clib_compiler.find_library("gmock", self.env, [])
          gmock_main_detect = self.clib_compiler.find_library("gmock_main", self.env, [])
          if gmock_detect and (not self.main or gmock_main_detect):
              self.is_found = True
              self.link_args += gmock_detect
              if self.main:
                  self.link_args += gmock_main_detect
              self.prebuilt = True
              return
  
          for d in ['/usr/src/googletest/googlemock/src', '/usr/src/gmock/src', '/usr/src/gmock']:
              if os.path.exists(d):
                  self.is_found = True
                  # Yes, we need both because there are multiple
                  # versions of gmock that do different things.
                  d2 = os.path.normpath(os.path.join(d, '..'))
                  self.compile_args += ['-I' + d, '-I' + d2, '-I' + os.path.join(d2, 'include')]
                  all_src = mesonlib.File.from_absolute_file(os.path.join(d, 'gmock-all.cc'))
                  main_src = mesonlib.File.from_absolute_file(os.path.join(d, 'gmock_main.cc'))
                  if self.main:
                      self.sources += [all_src, main_src]
                  else:
                      self.sources += [all_src]
                  self.prebuilt = False
                  return
  
          self.is_found = False
  
      def log_info(self):
          if self.prebuilt:
              return 'prebuilt'
          else:
              return 'building self'
  
      def log_tried(self):
          return 'system'
  
      @classmethod
      def _factory(cls, environment, kwargs):
          methods = cls._process_method_kw(kwargs)
          candidates = []
  
          if DependencyMethods.PKGCONFIG in methods:
              pcname = 'gmock_main' if kwargs.get('main', False) else 'gmock'
              candidates.append(functools.partial(PkgConfigDependency, pcname, environment, kwargs))
  
          if DependencyMethods.SYSTEM in methods:
              candidates.append(functools.partial(GMockDependency, environment, kwargs))
  
          return candidates
  
      @staticmethod
      def get_methods():
          return [DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM]
  
  
  class LLVMDependencyConfigTool(ConfigToolDependency):
      """
      LLVM uses a special tool, llvm-config, which has arguments for getting
      c args, cxx args, and ldargs as well as version.
      """
      tool_name = 'llvm-config'
      __cpp_blacklist = {'-DNDEBUG'}
  
      def __init__(self, environment, kwargs):
          # Already called by `super().__init__`, but need `self.for_machine`
          # before `super().__init__` is called.
          HasNativeKwarg.__init__(self, kwargs)
  
          self.tools = get_llvm_tool_names('llvm-config')
  
          # Fedora starting with Fedora 30 adds a suffix of the number
          # of bits in the isa that llvm targets, for example, on x86_64
          # and aarch64 the name will be llvm-config-64, on x86 and arm
          # it will be llvm-config-32.
          if environment.machines[self.for_machine].is_64_bit:
              self.tools.append('llvm-config-64')
          else:
              self.tools.append('llvm-config-32')
  
          # It's necessary for LLVM <= 3.8 to use the C++ linker. For 3.9 and 4.0
          # the C linker works fine if only using the C API.
          super().__init__('LLVM', environment, 'cpp', kwargs)
          self.provided_modules = []
          self.required_modules = set()
          self.module_details = []
          if not self.is_found:
              return
          self.static = kwargs.get('static', False)
  
          self.provided_modules = self.get_config_value(['--components'], 'modules')
          modules = stringlistify(extract_as_list(kwargs, 'modules'))
          self.check_components(modules)
          opt_modules = stringlistify(extract_as_list(kwargs, 'optional_modules'))
          self.check_components(opt_modules, required=False)
  
          cargs = set(self.get_config_value(['--cppflags'], 'compile_args'))
          self.compile_args = list(cargs.difference(self.__cpp_blacklist))
  
          if version_compare(self.version, '>= 3.9'):
              self._set_new_link_args(environment)
          else:
              self._set_old_link_args()
          self.link_args = strip_system_libdirs(environment, self.for_machine, self.link_args)
          self.link_args = self.__fix_bogus_link_args(self.link_args)
          self._add_sub_dependency(ThreadDependency, environment, kwargs)
  
      def __fix_bogus_link_args(self, args):
          """This function attempts to fix bogus link arguments that llvm-config
          generates.
  
          Currently it works around the following:
              - FreeBSD: when statically linking -l/usr/lib/libexecinfo.so will
                be generated, strip the -l in cases like this.
              - Windows: We may get -LIBPATH:... which is later interpreted as
                "-L IBPATH:...", if we're using an msvc like compilers convert
                that to "/LIBPATH", otherwise to "-L ..."
          """
          cpp = self.env.coredata.compilers[self.for_machine]['cpp']
  
          new_args = []
          for arg in args:
              if arg.startswith('-l') and arg.endswith('.so'):
                  new_args.append(arg.lstrip('-l'))
              elif arg.startswith('-LIBPATH:'):
                  new_args.extend(cpp.get_linker_search_args(arg.lstrip('-LIBPATH:')))
              else:
                  new_args.append(arg)
          return new_args
  
      def __check_libfiles(self, shared):
          """Use llvm-config's --libfiles to check if libraries exist."""
          mode = '--link-shared' if shared else '--link-static'
  
          # Set self.required to true to force an exception in get_config_value
          # if the returncode != 0
          restore = self.required
          self.required = True
  
          try:
              # It doesn't matter what the stage is, the caller needs to catch
              # the exception anyway.
              self.link_args = self.get_config_value(['--libfiles', mode], '')
          finally:
              self.required = restore
  
      def _set_new_link_args(self, environment):
          """How to set linker args for LLVM versions >= 3.9"""
          mode = self.get_config_value(['--shared-mode'], 'link_args')[0]
          if not self.static and mode == 'static':
              # If llvm is configured with LLVM_BUILD_LLVM_DYLIB but not with
              # LLVM_LINK_LLVM_DYLIB and not LLVM_BUILD_SHARED_LIBS (which
              # upstreams doesn't recomend using), then llvm-config will lie to
              # you about how to do shared-linking. It wants to link to a a bunch
              # of individual shared libs (which don't exist because llvm wasn't
              # built with LLVM_BUILD_SHARED_LIBS.
              #
              # Therefore, we'll try to get the libfiles, if the return code is 0
              # or we get an empty list, then we'll try to build a working
              # configuration by hand.
              try:
                  self.__check_libfiles(True)
              except DependencyException:
                  lib_ext = get_shared_library_suffix(environment, self.for_machine)
                  libdir = self.get_config_value(['--libdir'], 'link_args')[0]
                  # Sort for reproducability
                  matches = sorted(glob.iglob(os.path.join(libdir, 'libLLVM*{}'.format(lib_ext))))
                  if not matches:
                      if self.required:
                          raise
                      self.is_found = False
                      return
  
                  self.link_args = self.get_config_value(['--ldflags'], 'link_args')
                  libname = os.path.basename(matches[0]).rstrip(lib_ext).lstrip('lib')
                  self.link_args.append('-l{}'.format(libname))
                  return
          elif self.static and mode == 'shared':
              # If, however LLVM_BUILD_SHARED_LIBS is true # (*cough* gentoo *cough*)
              # then this is correct. Building with LLVM_BUILD_SHARED_LIBS has a side
              # effect, it stops the generation of static archives. Therefore we need
              # to check for that and error out on static if this is the case
              try:
                  self.__check_libfiles(False)
              except DependencyException:
                  if self.required:
                      raise
                  self.is_found = False
                  return
  
          link_args = ['--link-static', '--system-libs'] if self.static else ['--link-shared']
          self.link_args = self.get_config_value(
              ['--libs', '--ldflags'] + link_args + list(self.required_modules),
              'link_args')
  
      def _set_old_link_args(self):
          """Setting linker args for older versions of llvm.
  
          Old versions of LLVM bring an extra level of insanity with them.
          llvm-config will provide the correct arguments for static linking, but
          not for shared-linnking, we have to figure those out ourselves, because
          of course we do.
          """
          if self.static:
              self.link_args = self.get_config_value(
                  ['--libs', '--ldflags', '--system-libs'] + list(self.required_modules),
                  'link_args')
          else:
              # llvm-config will provide arguments for static linking, so we get
              # to figure out for ourselves what to link with. We'll do that by
              # checking in the directory provided by --libdir for a library
              # called libLLVM-<ver>.(so|dylib|dll)
              libdir = self.get_config_value(['--libdir'], 'link_args')[0]
  
              expected_name = 'libLLVM-{}'.format(self.version)
              re_name = re.compile(r'{}.(so|dll|dylib)$'.format(expected_name))
  
              for file_ in os.listdir(libdir):
                  if re_name.match(file_):
                      self.link_args = ['-L{}'.format(libdir),
                                        '-l{}'.format(os.path.splitext(file_.lstrip('lib'))[0])]
                      break
              else:
                  raise DependencyException(
                      'Could not find a dynamically linkable library for LLVM.')
  
      def check_components(self, modules, required=True):
          """Check for llvm components (modules in meson terms).
  
          The required option is whether the module is required, not whether LLVM
          is required.
          """
          for mod in sorted(set(modules)):
              status = ''
  
              if mod not in self.provided_modules:
                  if required:
                      self.is_found = False
                      if self.required:
                          raise DependencyException(
                              'Could not find required LLVM Component: {}'.format(mod))
                      status = '(missing)'
                  else:
                      status = '(missing but optional)'
              else:
                  self.required_modules.add(mod)
  
              self.module_details.append(mod + status)
  
      def log_details(self):
          if self.module_details:
              return 'modules: ' + ', '.join(self.module_details)
          return ''
  
  class LLVMDependencyCMake(CMakeDependency):
      def __init__(self, env, kwargs):
          self.llvm_modules = stringlistify(extract_as_list(kwargs, 'modules'))
          self.llvm_opt_modules = stringlistify(extract_as_list(kwargs, 'optional_modules'))
          super().__init__(name='LLVM', environment=env, language='cpp', kwargs=kwargs)
  
          # Extract extra include directories and definitions
          inc_dirs = self.traceparser.get_cmake_var('PACKAGE_INCLUDE_DIRS')
          defs = self.traceparser.get_cmake_var('PACKAGE_DEFINITIONS')
          temp = ['-I' + x for x in inc_dirs] + defs
          self.compile_args += [x for x in temp if x not in self.compile_args]
          self._add_sub_dependency(ThreadDependency, env, kwargs)
  
      def _main_cmake_file(self) -> str:
          # Use a custom CMakeLists.txt for LLVM
          return 'CMakeListsLLVM.txt'
  
      def _extra_cmake_opts(self) -> List[str]:
          return ['-DLLVM_MESON_MODULES={}'.format(';'.join(self.llvm_modules + self.llvm_opt_modules))]
  
      def _map_module_list(self, modules: List[Tuple[str, bool]]) -> List[Tuple[str, bool]]:
          res = []
          for mod, required in modules:
              cm_targets = self.traceparser.get_cmake_var('MESON_LLVM_TARGETS_{}'.format(mod))
              if not cm_targets:
                  if required:
                      raise self._gen_exception('LLVM module {} was not found'.format(mod))
                  else:
                      mlog.warning('Optional LLVM module', mlog.bold(mod), 'was not found')
                      continue
              for i in cm_targets:
                  res += [(i, required)]
          return res
  
      def _original_module_name(self, module: str) -> str:
          orig_name = self.traceparser.get_cmake_var('MESON_TARGET_TO_LLVM_{}'.format(module))
          if orig_name:
              return orig_name[0]
          return module
  
  class LLVMDependency(ExternalDependency):
      def __init__(self, env, kwargs):
          super().__init__('LLVM', env, 'cpp', kwargs)
  
      @classmethod
      def _factory(cls, env, kwargs):
          methods = cls._process_method_kw(kwargs)
          candidates = []
  
          if DependencyMethods.CONFIG_TOOL in methods:
              candidates.append(functools.partial(LLVMDependencyConfigTool, env, kwargs))
  
          if DependencyMethods.CMAKE in methods:
              candidates.append(functools.partial(LLVMDependencyCMake, env, kwargs))
  
          return candidates
  
      @staticmethod
      def get_methods():
          return [DependencyMethods.CMAKE, DependencyMethods.CONFIG_TOOL]
  
  class ValgrindDependency(PkgConfigDependency):
      '''
      Consumers of Valgrind usually only need the compile args and do not want to
      link to its (static) libraries.
      '''
      def __init__(self, env, kwargs):
          super().__init__('valgrind', env, kwargs)
  
      def get_link_args(self, **kwargs):
          return []
  
files: mesonbuild/dependencies/dev.py
files: # Copyright 2013-2019 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.
  
  # This file contains the detection logic for external dependencies useful for
  # development purposes, such as testing, debugging, etc..
  
  import functools
  import glob
  import os
  import re
  
  from .. import mesonlib, mlog
  from ..mesonlib import version_compare, stringlistify, extract_as_list, MachineChoice
  from .base import (
      DependencyException, DependencyMethods, ExternalDependency, PkgConfigDependency,
      strip_system_libdirs, ConfigToolDependency, CMakeDependency, HasNativeKwarg
  )
  from .misc import ThreadDependency
  
  from typing import List, Tuple
  
  
  def get_shared_library_suffix(environment, for_machine: MachineChoice):
      """This is only gauranteed to work for languages that compile to machine
      code, not for languages like C# that use a bytecode and always end in .dll
      """
      m = environment.machines[for_machine]
      if m.is_windows():
          return '.dll'
      elif m.is_darwin():
          return '.dylib'
      return '.so'
  
  
  class GTestDependency(ExternalDependency):
      def __init__(self, environment, kwargs):
          super().__init__('gtest', environment, 'cpp', kwargs)
          self.main = kwargs.get('main', False)
          self.src_dirs = ['/usr/src/gtest/src', '/usr/src/googletest/googletest/src']
          self.detect()
          self._add_sub_dependency(ThreadDependency, environment, kwargs)
  
      def detect(self):
          gtest_detect = self.clib_compiler.find_library("gtest", self.env, [])
          gtest_main_detect = self.clib_compiler.find_library("gtest_main", self.env, [])
          if gtest_detect and (not self.main or gtest_main_detect):
              self.is_found = True
              self.compile_args = []
              self.link_args = gtest_detect
              if self.main:
                  self.link_args += gtest_main_detect
              self.sources = []
              self.prebuilt = True
          elif self.detect_srcdir():
              self.is_found = True
              self.compile_args = ['-I' + d for d in self.src_include_dirs]
              self.link_args = []
              if self.main:
                  self.sources = [self.all_src, self.main_src]
              else:
                  self.sources = [self.all_src]
              self.prebuilt = False
          else:
              self.is_found = False
  
      def detect_srcdir(self):
          for s in self.src_dirs:
              if os.path.exists(s):
                  self.src_dir = s
                  self.all_src = mesonlib.File.from_absolute_file(
                      os.path.join(self.src_dir, 'gtest-all.cc'))
                  self.main_src = mesonlib.File.from_absolute_file(
                      os.path.join(self.src_dir, 'gtest_main.cc'))
                  self.src_include_dirs = [os.path.normpath(os.path.join(self.src_dir, '..')),
                                           os.path.normpath(os.path.join(self.src_dir, '../include')),
                                           ]
                  return True
          return False
  
      def log_info(self):
          if self.prebuilt:
              return 'prebuilt'
          else:
              return 'building self'
  
      def log_tried(self):
          return 'system'
  
      @classmethod
      def _factory(cls, environment, kwargs):
          methods = cls._process_method_kw(kwargs)
          candidates = []
  
          if DependencyMethods.PKGCONFIG in methods:
              pcname = 'gtest_main' if kwargs.get('main', False) else 'gtest'
              candidates.append(functools.partial(PkgConfigDependency, pcname, environment, kwargs))
  
          if DependencyMethods.SYSTEM in methods:
              candidates.append(functools.partial(GTestDependency, environment, kwargs))
  
          return candidates
  
      @staticmethod
      def get_methods():
          return [DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM]
  
  
  class GMockDependency(ExternalDependency):
      def __init__(self, environment, kwargs):
          super().__init__('gmock', environment, 'cpp', kwargs)
          self.main = kwargs.get('main', False)
          self._add_sub_dependency(ThreadDependency, environment, kwargs)
  
          # If we are getting main() from GMock, we definitely
          # want to avoid linking in main() from GTest
          gtest_kwargs = kwargs.copy()
          if self.main:
              gtest_kwargs['main'] = False
  
          # GMock without GTest is pretty much useless
          # this also mimics the structure given in WrapDB,
          # where GMock always pulls in GTest
          gtest_dep = GTestDependency(environment, gtest_kwargs)
          if not gtest_dep.is_found:
              self.is_found = False
              return
          self.ext_deps.append(gtest_dep)
  
          # GMock may be a library or just source.
          # Work with both.
          gmock_detect = self.clib_compiler.find_library("gmock", self.env, [])
          gmock_main_detect = self.clib_compiler.find_library("gmock_main", self.env, [])
          if gmock_detect and (not self.main or gmock_main_detect):
              self.is_found = True
              self.link_args += gmock_detect
              if self.main:
                  self.link_args += gmock_main_detect
              self.prebuilt = True
              return
  
          for d in ['/usr/src/googletest/googlemock/src', '/usr/src/gmock/src', '/usr/src/gmock']:
              if os.path.exists(d):
                  self.is_found = True
                  # Yes, we need both because there are multiple
                  # versions of gmock that do different things.
                  d2 = os.path.normpath(os.path.join(d, '..'))
                  self.compile_args += ['-I' + d, '-I' + d2, '-I' + os.path.join(d2, 'include')]
                  all_src = mesonlib.File.from_absolute_file(os.path.join(d, 'gmock-all.cc'))
                  main_src = mesonlib.File.from_absolute_file(os.path.join(d, 'gmock_main.cc'))
                  if self.main:
                      self.sources += [all_src, main_src]
                  else:
                      self.sources += [all_src]
                  self.prebuilt = False
                  return
  
          self.is_found = False
  
      def log_info(self):
          if self.prebuilt:
              return 'prebuilt'
          else:
              return 'building self'
  
      def log_tried(self):
          return 'system'
  
      @classmethod
      def _factory(cls, environment, kwargs):
          methods = cls._process_method_kw(kwargs)
          candidates = []
  
          if DependencyMethods.PKGCONFIG in methods:
              pcname = 'gmock_main' if kwargs.get('main', False) else 'gmock'
              candidates.append(functools.partial(PkgConfigDependency, pcname, environment, kwargs))
  
          if DependencyMethods.SYSTEM in methods:
              candidates.append(functools.partial(GMockDependency, environment, kwargs))
  
          return candidates
  
      @staticmethod
      def get_methods():
          return [DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM]
  
  
  class LLVMDependencyConfigTool(ConfigToolDependency):
      """
      LLVM uses a special tool, llvm-config, which has arguments for getting
      c args, cxx args, and ldargs as well as version.
      """
      tool_name = 'llvm-config'
      __cpp_blacklist = {'-DNDEBUG'}
  
      def __init__(self, environment, kwargs):
          # Already called by `super().__init__`, but need `self.for_machine`
          # before `super().__init__` is called.
          HasNativeKwarg.__init__(self, kwargs)
  
          # Ordered list of llvm-config binaries to try. Start with base, then try
          # newest back to oldest (3.5 is arbitrary), and finally the devel version.
          # Please note that llvm-config-6.0 is a development snapshot and it should
          # not be moved to the beginning of the list.
          self.tools = [
              'llvm-config', # base
              'llvm-config-8',   'llvm-config80',
              'llvm-config-7',   'llvm-config70',
              'llvm-config-6.0', 'llvm-config60',
              'llvm-config-5.0', 'llvm-config50',
              'llvm-config-4.0', 'llvm-config40',
              'llvm-config-3.9', 'llvm-config39',
              'llvm-config-3.8', 'llvm-config38',
              'llvm-config-3.7', 'llvm-config37',
              'llvm-config-3.6', 'llvm-config36',
              'llvm-config-3.5', 'llvm-config35',
              'llvm-config-9',     # Debian development snapshot
              'llvm-config-devel', # FreeBSD development snapshot
          ]
  
          # Fedora starting with Fedora 30 adds a suffix of the number
          # of bits in the isa that llvm targets, for example, on x86_64
          # and aarch64 the name will be llvm-config-64, on x86 and arm
          # it will be llvm-config-32.
          if environment.machines[self.for_machine].is_64_bit:
              self.tools.append('llvm-config-64')
          else:
              self.tools.append('llvm-config-32')
  
          # It's necessary for LLVM <= 3.8 to use the C++ linker. For 3.9 and 4.0
          # the C linker works fine if only using the C API.
          super().__init__('LLVM', environment, 'cpp', kwargs)
          self.provided_modules = []
          self.required_modules = set()
          self.module_details = []
          if not self.is_found:
              return
          self.static = kwargs.get('static', False)
  
          self.provided_modules = self.get_config_value(['--components'], 'modules')
          modules = stringlistify(extract_as_list(kwargs, 'modules'))
          self.check_components(modules)
          opt_modules = stringlistify(extract_as_list(kwargs, 'optional_modules'))
          self.check_components(opt_modules, required=False)
  
          cargs = set(self.get_config_value(['--cppflags'], 'compile_args'))
          self.compile_args = list(cargs.difference(self.__cpp_blacklist))
  
          if version_compare(self.version, '>= 3.9'):
              self._set_new_link_args(environment)
          else:
              self._set_old_link_args()
          self.link_args = strip_system_libdirs(environment, self.for_machine, self.link_args)
          self.link_args = self.__fix_bogus_link_args(self.link_args)
          self._add_sub_dependency(ThreadDependency, environment, kwargs)
  
      def __fix_bogus_link_args(self, args):
          """This function attempts to fix bogus link arguments that llvm-config
          generates.
  
          Currently it works around the following:
              - FreeBSD: when statically linking -l/usr/lib/libexecinfo.so will
                be generated, strip the -l in cases like this.
              - Windows: We may get -LIBPATH:... which is later interpreted as
                "-L IBPATH:...", if we're using an msvc like compilers convert
                that to "/LIBPATH", otherwise to "-L ..."
          """
          cpp = self.env.coredata.compilers[self.for_machine]['cpp']
  
          new_args = []
          for arg in args:
              if arg.startswith('-l') and arg.endswith('.so'):
                  new_args.append(arg.lstrip('-l'))
              elif arg.startswith('-LIBPATH:'):
                  new_args.extend(cpp.get_linker_search_args(arg.lstrip('-LIBPATH:')))
              else:
                  new_args.append(arg)
          return new_args
  
      def __check_libfiles(self, shared):
          """Use llvm-config's --libfiles to check if libraries exist."""
          mode = '--link-shared' if shared else '--link-static'
  
          # Set self.required to true to force an exception in get_config_value
          # if the returncode != 0
          restore = self.required
          self.required = True
  
          try:
              # It doesn't matter what the stage is, the caller needs to catch
              # the exception anyway.
              self.link_args = self.get_config_value(['--libfiles', mode], '')
          finally:
              self.required = restore
  
      def _set_new_link_args(self, environment):
          """How to set linker args for LLVM versions >= 3.9"""
          mode = self.get_config_value(['--shared-mode'], 'link_args')[0]
          if not self.static and mode == 'static':
              # If llvm is configured with LLVM_BUILD_LLVM_DYLIB but not with
              # LLVM_LINK_LLVM_DYLIB and not LLVM_BUILD_SHARED_LIBS (which
              # upstreams doesn't recomend using), then llvm-config will lie to
              # you about how to do shared-linking. It wants to link to a a bunch
              # of individual shared libs (which don't exist because llvm wasn't
              # built with LLVM_BUILD_SHARED_LIBS.
              #
              # Therefore, we'll try to get the libfiles, if the return code is 0
              # or we get an empty list, then we'll try to build a working
              # configuration by hand.
              try:
                  self.__check_libfiles(True)
              except DependencyException:
                  lib_ext = get_shared_library_suffix(environment, self.for_machine)
                  libdir = self.get_config_value(['--libdir'], 'link_args')[0]
                  # Sort for reproducability
                  matches = sorted(glob.iglob(os.path.join(libdir, 'libLLVM*{}'.format(lib_ext))))
                  if not matches:
                      if self.required:
                          raise
                      self.is_found = False
                      return
  
                  self.link_args = self.get_config_value(['--ldflags'], 'link_args')
                  libname = os.path.basename(matches[0]).rstrip(lib_ext).lstrip('lib')
                  self.link_args.append('-l{}'.format(libname))
                  return
          elif self.static and mode == 'shared':
              # If, however LLVM_BUILD_SHARED_LIBS is true # (*cough* gentoo *cough*)
              # then this is correct. Building with LLVM_BUILD_SHARED_LIBS has a side
              # effect, it stops the generation of static archives. Therefore we need
              # to check for that and error out on static if this is the case
              try:
                  self.__check_libfiles(False)
              except DependencyException:
                  if self.required:
                      raise
                  self.is_found = False
                  return
  
          link_args = ['--link-static', '--system-libs'] if self.static else ['--link-shared']
          self.link_args = self.get_config_value(
              ['--libs', '--ldflags'] + link_args + list(self.required_modules),
              'link_args')
  
      def _set_old_link_args(self):
          """Setting linker args for older versions of llvm.
  
          Old versions of LLVM bring an extra level of insanity with them.
          llvm-config will provide the correct arguments for static linking, but
          not for shared-linnking, we have to figure those out ourselves, because
          of course we do.
          """
          if self.static:
              self.link_args = self.get_config_value(
                  ['--libs', '--ldflags', '--system-libs'] + list(self.required_modules),
                  'link_args')
          else:
              # llvm-config will provide arguments for static linking, so we get
              # to figure out for ourselves what to link with. We'll do that by
              # checking in the directory provided by --libdir for a library
              # called libLLVM-<ver>.(so|dylib|dll)
              libdir = self.get_config_value(['--libdir'], 'link_args')[0]
  
              expected_name = 'libLLVM-{}'.format(self.version)
              re_name = re.compile(r'{}.(so|dll|dylib)$'.format(expected_name))
  
              for file_ in os.listdir(libdir):
                  if re_name.match(file_):
                      self.link_args = ['-L{}'.format(libdir),
                                        '-l{}'.format(os.path.splitext(file_.lstrip('lib'))[0])]
                      break
              else:
                  raise DependencyException(
                      'Could not find a dynamically linkable library for LLVM.')
  
      def check_components(self, modules, required=True):
          """Check for llvm components (modules in meson terms).
  
          The required option is whether the module is required, not whether LLVM
          is required.
          """
          for mod in sorted(set(modules)):
              status = ''
  
              if mod not in self.provided_modules:
                  if required:
                      self.is_found = False
                      if self.required:
                          raise DependencyException(
                              'Could not find required LLVM Component: {}'.format(mod))
                      status = '(missing)'
                  else:
                      status = '(missing but optional)'
              else:
                  self.required_modules.add(mod)
  
              self.module_details.append(mod + status)
  
      def log_details(self):
          if self.module_details:
              return 'modules: ' + ', '.join(self.module_details)
          return ''
  
  class LLVMDependencyCMake(CMakeDependency):
      def __init__(self, env, kwargs):
          self.llvm_modules = stringlistify(extract_as_list(kwargs, 'modules'))
          self.llvm_opt_modules = stringlistify(extract_as_list(kwargs, 'optional_modules'))
          super().__init__(name='LLVM', environment=env, language='cpp', kwargs=kwargs)
  
          # Extract extra include directories and definitions
          inc_dirs = self.traceparser.get_cmake_var('PACKAGE_INCLUDE_DIRS')
          defs = self.traceparser.get_cmake_var('PACKAGE_DEFINITIONS')
          temp = ['-I' + x for x in inc_dirs] + defs
          self.compile_args += [x for x in temp if x not in self.compile_args]
          self._add_sub_dependency(ThreadDependency, env, kwargs)
  
      def _main_cmake_file(self) -> str:
          # Use a custom CMakeLists.txt for LLVM
          return 'CMakeListsLLVM.txt'
  
      def _extra_cmake_opts(self) -> List[str]:
          return ['-DLLVM_MESON_MODULES={}'.format(';'.join(self.llvm_modules + self.llvm_opt_modules))]
  
      def _map_module_list(self, modules: List[Tuple[str, bool]]) -> List[Tuple[str, bool]]:
          res = []
          for mod, required in modules:
              cm_targets = self.traceparser.get_cmake_var('MESON_LLVM_TARGETS_{}'.format(mod))
              if not cm_targets:
                  if required:
                      raise self._gen_exception('LLVM module {} was not found'.format(mod))
                  else:
                      mlog.warning('Optional LLVM module', mlog.bold(mod), 'was not found')
                      continue
              for i in cm_targets:
                  res += [(i, required)]
          return res
  
      def _original_module_name(self, module: str) -> str:
          orig_name = self.traceparser.get_cmake_var('MESON_TARGET_TO_LLVM_{}'.format(module))
          if orig_name:
              return orig_name[0]
          return module
  
  class LLVMDependency(ExternalDependency):
      def __init__(self, env, kwargs):
          super().__init__('LLVM', env, 'cpp', kwargs)
  
      @classmethod
      def _factory(cls, env, kwargs):
          methods = cls._process_method_kw(kwargs)
          candidates = []
  
          if DependencyMethods.CONFIG_TOOL in methods:
              candidates.append(functools.partial(LLVMDependencyConfigTool, env, kwargs))
  
          if DependencyMethods.CMAKE in methods:
              candidates.append(functools.partial(LLVMDependencyCMake, env, kwargs))
  
          return candidates
  
      @staticmethod
      def get_methods():
          return [DependencyMethods.CMAKE, DependencyMethods.CONFIG_TOOL]
  
  class ValgrindDependency(PkgConfigDependency):
      '''
      Consumers of Valgrind usually only need the compile args and do not want to
      link to its (static) libraries.
      '''
      def __init__(self, env, kwargs):
          super().__init__('valgrind', env, kwargs)
  
      def get_link_args(self, **kwargs):
          return []
  
files: mesonbuild/dependencies/dev.py
files: # Copyright 2012-2016 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 os, platform, re, sys, shutil, subprocess, typing
  import tempfile
  import shlex
  
  from . import coredata
  from .linkers import ArLinker, ArmarLinker, VisualStudioLinker, DLinker, CcrxLinker, IntelVisualStudioLinker
  from . import mesonlib
  from .mesonlib import (
      MesonException, EnvironmentException, MachineChoice, Popen_safe,
      PerMachineDefaultable, PerThreeMachineDefaultable, split_args, quote_arg
  )
  from . import mlog
  
  from .envconfig import (
      BinaryTable, Directories, MachineInfo, MesonConfigFile,
      Properties, known_cpu_families,
  )
  from . import compilers
  from .compilers import (
      Compiler,
      CompilerType,
      is_assembly,
      is_header,
      is_library,
      is_llvm_ir,
      is_object,
      is_source,
  )
  from .linkers import (
      AppleDynamicLinker,
      ArmClangDynamicLinker,
      ArmDynamicLinker,
      CcrxDynamicLinker,
      ClangClDynamicLinker,
      DynamicLinker,
      GnuDynamicLinker,
      LLVMDynamicLinker,
      MSVCDynamicLinker,
      OptlinkDynamicLinker,
      PGIDynamicLinker,
      PGIStaticLinker,
      SolarisDynamicLinker,
      XildAppleDynamicLinker,
      XildLinuxDynamicLinker,
      XilinkDynamicLinker,
      CudaLinker,
  )
  from functools import lru_cache
  from .compilers import (
      ArmCCompiler,
      ArmCPPCompiler,
      ArmclangCCompiler,
      ArmclangCPPCompiler,
      ClangCCompiler,
      ClangCPPCompiler,
      ClangObjCCompiler,
      ClangObjCPPCompiler,
      ClangClCCompiler,
      ClangClCPPCompiler,
      FlangFortranCompiler,
      G95FortranCompiler,
      GnuCCompiler,
      GnuCPPCompiler,
      GnuFortranCompiler,
      GnuObjCCompiler,
      GnuObjCPPCompiler,
      ElbrusCCompiler,
      ElbrusCPPCompiler,
      ElbrusFortranCompiler,
      EmscriptenCCompiler,
      EmscriptenCPPCompiler,
      IntelCCompiler,
      IntelClCCompiler,
      IntelCPPCompiler,
      IntelClCPPCompiler,
      IntelFortranCompiler,
      IntelClFortranCompiler,
      JavaCompiler,
      MonoCompiler,
      CudaCompiler,
      VisualStudioCsCompiler,
      NAGFortranCompiler,
      Open64FortranCompiler,
      PathScaleFortranCompiler,
      PGICCompiler,
      PGICPPCompiler,
      PGIFortranCompiler,
      RustCompiler,
      CcrxCCompiler,
      CcrxCPPCompiler,
      SunFortranCompiler,
      ValaCompiler,
      VisualStudioCCompiler,
      VisualStudioCPPCompiler,
  )
  
  build_filename = 'meson.build'
  
  CompilersDict = typing.Dict[str, Compiler]
  
  def detect_gcovr(min_version='3.3', new_rootdir_version='4.2', 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, mesonlib.version_compare(found, '>=' + new_rootdir_version)
      return None, None
  
  def find_coverage_tools():
      gcovr_exe, gcovr_new_rootdir = detect_gcovr()
  
      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_new_rootdir, lcov_exe, genhtml_exe
  
  def detect_ninja(version: str = '1.5', log: bool = False) -> str:
      env_ninja = os.environ.get('NINJA', None)
      for n in [env_ninja] if env_ninja else ['ninja', 'ninja-build', 'samu']:
          try:
              p, found = Popen_safe([n, '--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):
              n = shutil.which(n)
              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, quote_arg(n)))
              return n
  
  def get_llvm_tool_names(tool: str) -> typing.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)
          '-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',
          '-9',     # Debian development snapshot
          '-devel', # FreeBSD development snapshot
      ]
      names = []
      for suffix in suffixes:
          names.append(tool + suffix)
      return names
  
  def detect_scanbuild():
      """ 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_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():
          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.startswith('arm') or trial.startswith('earm'):
          trial = 'arm'
      elif trial.startswith(('powerpc64', 'ppc64')):
          trial = 'ppc64'
      elif trial.startswith(('powerpc', 'ppc')):
          trial = 'ppc'
      elif trial == 'macppc':
          trial = 'ppc'
      elif trial in ('amd64', 'x64', 'i86pc'):
          trial = 'x86_64'
  
      # 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'
  
      if trial not in known_cpu_families:
          mlog.warning('Unknown CPU family {!r}, please report this at '
                       'https://github.com/mesonbuild/meson/issues/new with the'
                       'output of `uname -a` and `cat /proc/cpuinfo`'.format(trial))
  
      return trial
  
  def detect_cpu(compilers: CompilersDict):
      if mesonlib.is_windows():
          trial = detect_windows_arch(compilers)
      elif mesonlib.is_freebsd() or mesonlib.is_netbsd() or mesonlib.is_openbsd():
          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 == 'aarch64':
          # Same check as above for cpu_family
          if any_compiler_has_define(compilers, '__arm__'):
              trial = 'arm'
      elif trial.startswith('earm'):
          trial = 'arm'
      elif trial == 'e2k':
          # Make more precise CPU detection for Elbrus platform.
          trial = platform.processor().lower()
      # Add more quirks here as bugs are reported. Keep in sync with
      # detect_cpu_family() above.
      return trial
  
  def detect_system():
      system = platform.system().lower()
      if system.startswith('cygwin'):
          return 'cygwin'
      return system
  
  def detect_msys2_arch():
      if 'MSYSTEM_CARCH' in os.environ:
          return os.environ['MSYSTEM_CARCH']
      return None
  
  def detect_machine_info(compilers: typing.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'))
  
  def search_version(text):
      # Usually of the type 4.1.4 but compiler output may contain
      # stuff like this:
      # (Sourcery CodeBench Lite 2014.05-29) 4.8.3 20140320 (prerelease)
      # Limiting major version number to two digits seems to work
      # thus far. When we get to GCC 100, this will break, but
      # if we are still relevant when that happens, it can be
      # considered an achievement in itself.
      #
      # This regex is reaching magic levels. If it ever needs
      # to be updated, do not complexify but convert to something
      # saner instead.
      # We'll demystify it a bit with a verbose definition.
      version_regex = re.compile(r"""
      (?<!                # Zero-width negative lookbehind assertion
          (
              \d          # One digit
              | \.        # Or one period
          )               # One occurrence
      )
      # Following pattern must not follow a digit or period
      (
          \d{1,2}         # One or two digits
          (
              \.\d+       # Period and one or more digits
          )+              # One or more occurrences
          (
              -[a-zA-Z0-9]+   # Hyphen and one or more alphanumeric
          )?              # Zero or one occurrence
      )                   # One occurrence
      """, re.VERBOSE)
      match = version_regex.search(text)
      if match:
          return match.group(0)
      return 'unknown version'
  
  class Environment:
      private_dir = 'meson-private'
      log_dir = 'meson-logs'
      info_dir = 'meson-info'
  
      def __init__(self, source_dir, build_dir, options):
          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())
                  self.first_invocation = False
              except FileNotFoundError:
                  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()
  
          # Similar to coredata.compilers, but lower level in that there is no
          # meta data, only names/paths.
          binaries = PerMachineDefaultable()
  
          # Misc other properties about each machine.
          properties = PerMachineDefaultable()
  
          # Store paths for native and cross build files. There is no target
          # machine information here because nothing is installed for the target
          # architecture, just the build and host architectures
          paths = PerMachineDefaultable()
  
          ## 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()
  
          ## Read in native file(s) to override build machine configuration
  
          if self.coredata.config_files is not None:
              config = MesonConfigFile.from_config_parser(
                  coredata.load_configs(self.coredata.config_files))
              binaries.build = BinaryTable(config.get('binaries', {}))
              paths.build = Directories(**config.get('paths', {}))
  
          ## Read in cross file(s) to override host machine configuration
  
          if self.coredata.cross_files:
              config = MesonConfigFile.from_config_parser(
                  coredata.load_configs(self.coredata.cross_files))
              properties.host = Properties(config.get('properties', {}), False)
              binaries.host = BinaryTable(config.get('binaries', {}), False)
              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'])
              paths.host = Directories(**config.get('paths', {}))
  
          ## "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.paths = paths.default_missing()
  
          exe_wrapper = self.binaries.host.lookup_entry('exe_wrapper')
          if exe_wrapper is not None:
              from .dependencies import ExternalProgram
              self.exe_wrapper = ExternalProgram.from_bin_list(
                  self.binaries.host,
                  'exe_wrapper')
          else:
              self.exe_wrapper = None
  
          self.cmd_line_options = options.cmd_line_options.copy()
  
          # List of potential compilers.
          if mesonlib.is_windows():
              # Intel C and C++ compiler is icl on Windows, but icc and icpc elsewhere.
              # Search for icl before cl, since Intel "helpfully" provides a
              # cl.exe that returns *exactly the same thing* that microsofts
              # cl.exe does, and if icl is present, it's almost certainly what
              # you want.
              self.default_c = ['icl', 'cl', 'cc', 'gcc', 'clang', 'clang-cl', 'pgcc']
              # There is currently no pgc++ for Windows, only for  Mac and Linux.
              self.default_cpp = ['icl', 'cl', 'c++', 'g++', 'clang++', 'clang-cl']
              self.default_fortran = ['ifort', 'gfortran', 'flang', 'pgfortran', 'g95']
              # Clang and clang++ are valid, but currently unsupported.
              self.default_objc = ['cc', 'gcc']
              self.default_objcpp = ['c++', 'g++']
              self.default_cs = ['csc', 'mcs']
          else:
              self.default_c = ['cc', 'gcc', 'clang', 'pgcc', 'icc']
              self.default_cpp = ['c++', 'g++', 'clang++', 'pgc++', 'icpc']
              self.default_fortran = ['gfortran', 'flang', 'pgfortran', 'ifort', 'g95']
              self.default_objc = ['cc', 'gcc', 'clang']
              self.default_objcpp = ['c++', 'g++', 'clang++']
              self.default_cs = ['mcs', 'csc']
          self.default_d = ['ldc2', 'ldc', 'gdc', 'dmd']
          self.default_java = ['javac']
          self.default_cuda = ['nvcc']
          self.default_rust = ['rustc']
          self.default_swift = ['swiftc']
          self.default_vala = ['valac']
          self.default_static_linker = ['ar', 'gar']
          self.default_strip = ['strip']
          self.vs_static_linker = ['lib']
          self.clang_cl_static_linker = ['llvm-lib']
          self.cuda_static_linker = ['nvlink']
          self.gcc_static_linker = ['gcc-ar']
          self.clang_static_linker = ['llvm-ar']
          self.default_cmake = ['cmake']
          self.default_pkgconfig = ['pkg-config']
  
      def create_new_coredata(self, options):
          # WARNING: Don't use any values from coredata in __init__. It gets
          # re-initialized with project options by the interpreter during
          # build file parsing.
          self.coredata = coredata.CoreData(options, self.scratch_dir)
          # Used by the regenchecker script, which runs meson
          self.coredata.meson_command = mesonlib.meson_command
          self.first_invocation = True
  
      def is_cross_build(self) -> bool:
          return not self.machines.matches_build_machine(MachineChoice.HOST)
  
      def dump_coredata(self):
          return coredata.save(self.coredata, self.get_build_dir())
  
      def get_script_dir(self):
          import mesonbuild.scripts
          return os.path.dirname(mesonbuild.scripts.__file__)
  
      def get_log_dir(self):
          return self.log_dir
  
      def get_coredata(self):
          return self.coredata
  
      def get_build_command(self, unbuffered=False):
          cmd = mesonlib.meson_command[:]
          if unbuffered and 'python' in os.path.basename(cmd[0]):
              cmd.insert(1, '-u')
          return cmd
  
      def is_header(self, fname):
          return is_header(fname)
  
      def is_source(self, fname):
          return is_source(fname)
  
      def is_assembly(self, fname):
          return is_assembly(fname)
  
      def is_llvm_ir(self, fname):
          return is_llvm_ir(fname)
  
      def is_object(self, fname):
          return is_object(fname)
  
      @lru_cache(maxsize=None)
      def is_library(self, fname):
          return is_library(fname)
  
      @staticmethod
      def get_gnu_compiler_defines(compiler):
          """
          Detect GNU compiler platform type (Apple, MinGW, Unix)
          """
          # Arguments to output compiler pre-processor defines to stdout
          # gcc, g++, and gfortran all support these arguments
          args = compiler + ['-E', '-dM', '-']
          p, output, error = Popen_safe(args, write='', stdin=subprocess.PIPE)
          if p.returncode != 0:
              raise EnvironmentException('Unable to detect GNU compiler type:\n' + output + error)
          # Parse several lines of the type:
          # `#define ___SOME_DEF some_value`
          # and extract `___SOME_DEF`
          defines = {}
          for line in output.split('\n'):
              if not line:
                  continue
              d, *rest = line.split(' ', 2)
              if d != '#define':
                  continue
              if len(rest) == 1:
                  defines[rest] = True
              if len(rest) == 2:
                  defines[rest[0]] = rest[1]
          return defines
  
      @staticmethod
      def get_gnu_version_from_defines(defines):
          dot = '.'
          major = defines.get('__GNUC__', '0')
          minor = defines.get('__GNUC_MINOR__', '0')
          patch = defines.get('__GNUC_PATCHLEVEL__', '0')
          return dot.join((major, minor, patch))
  
      @staticmethod
      def get_lcc_version_from_defines(defines):
          dot = '.'
          generation_and_major = defines.get('__LCC__', '100')
          generation = generation_and_major[:1]
          major = generation_and_major[1:]
          minor = defines.get('__LCC_MINOR__', '0')
          return dot.join((generation, major, minor))
  
      @staticmethod
      def get_gnu_compiler_type(defines):
          # Detect GCC type (Apple, MinGW, Cygwin, Unix)
          if '__APPLE__' in defines:
              return CompilerType.GCC_OSX
          elif '__MINGW32__' in defines or '__MINGW64__' in defines:
              return CompilerType.GCC_MINGW
          elif '__CYGWIN__' in defines:
              return CompilerType.GCC_CYGWIN
          return CompilerType.GCC_STANDARD
  
      def _get_compilers(self, lang, for_machine):
          '''
          The list of compilers is detected in the exact same way for
          C, C++, ObjC, ObjC++, Fortran, CS so consolidate it here.
          '''
          value = self.binaries[for_machine].lookup_entry(lang)
          if value is not None:
              compilers, ccache = BinaryTable.parse_entry(value)
              # Return value has to be a list of compiler 'choices'
              compilers = [compilers]
          else:
              if not self.machines.matches_build_machine(for_machine):
                  raise EnvironmentException('{!r} compiler binary not defined in cross or native file'.format(lang))
              compilers = getattr(self, 'default_' + lang)
              ccache = BinaryTable.detect_ccache()
  
          if self.machines.matches_build_machine(for_machine):
              exe_wrap = None
          else:
              exe_wrap = self.get_exe_wrapper()
  
          return compilers, ccache, exe_wrap
  
      def _handle_exceptions(self, exceptions, binaries, bintype='compiler'):
          errmsg = 'Unknown {}(s): {}'.format(bintype, binaries)
          if exceptions:
              errmsg += '\nThe follow exceptions were encountered:'
              for (c, e) in exceptions.items():
                  errmsg += '\nRunning "{0}" gave "{1}"'.format(c, e)
          raise EnvironmentException(errmsg)
  
      @staticmethod
      def _guess_win_linker(compiler: typing.List[str], for_machine: MachineChoice,
                            prefix: typing.Union[str, typing.List[str]]) -> 'DynamicLinker':
          # Explicitly pass logo here so that we can get the version of link.exe
          if isinstance(prefix, str):
              check_args = [prefix + '/logo', prefix + '--version']
          else:
              check_args = prefix + ['/logo'] + prefix + ['--version']
          p, o, _ = Popen_safe(compiler + check_args)
          if o.startswith('LLD'):
              if '(compatible with GNU linkers)' in o:
                  return LLVMDynamicLinker(compiler, for_machine, 'lld', prefix, version=search_version(o))
              else:
                  return ClangClDynamicLinker(for_machine, exelist=compiler, prefix=prefix, version=search_version(o))
          elif o.startswith('Microsoft'):
              match = re.search(r'.*(X86|X64|ARM|ARM64).*', o)
              if match:
                  target = str(match.group(1))
              else:
                  target = 'x86'
              return MSVCDynamicLinker(
                  for_machine, machine=target, exelist=compiler, prefix=prefix,
                  version=search_version(o))
          raise MesonException('Cannot guess dynamic linker')
  
      @staticmethod
      def _guess_nix_linker(compiler: typing.List[str], for_machine: MachineChoice,
                            prefix: typing.Union[str, typing.List[str]], *,
                            extra_args: typing.Optional[typing.List[str]] = None) -> 'DynamicLinker':
          """Helper for guessing what linker to use on Unix-Like OSes.
  
          :prefix: The prefix that the compiler uses to proxy arguments to the
              linker, if required. This can be passed as a string or a list of
              strings. If it is passed as a string then the arguments to be
              proxied to the linker will be concatenated, if it is a list they
              will be appended. This means that if a space is required (such as
              with swift which wants `-Xlinker --version` and *not*
              `-Xlinker=--version`) you must pass as a list.
          :extra_args: Any addtional arguments rquired (such as a source file)
          """
          extra_args = typing.cast(typing.List[str], extra_args or [])
          if isinstance(prefix, str):
              check_args = [prefix + '--version'] + extra_args
          else:
              check_args = prefix + ['--version'] + extra_args
          _, o, e = Popen_safe(compiler + check_args)
          v = search_version(o)
          if o.startswith('LLD'):
              linker = LLVMDynamicLinker(compiler, for_machine, 'lld', prefix, version=v)  # type: DynamicLinker
          elif e.startswith('lld-link: '):
              # Toolchain wrapper got in the way; this happens with e.g. https://github.com/mstorsjo/llvm-mingw
              # Let's try to extract the linker invocation command to grab the version.
  
              _, o, e = Popen_safe(compiler + check_args + ['-v'])
  
              try:
                  linker_cmd = re.match(r'.*\n(.*?)\nlld-link: ', e, re.DOTALL).group(1)
                  linker_cmd = shlex.split(linker_cmd)[0]
              except (AttributeError, IndexError, ValueError):
                  pass
              else:
                  _, o, e = Popen_safe([linker_cmd, '--version'])
                  v = search_version(o)
  
              linker = LLVMDynamicLinker(compiler, for_machine, 'lld', prefix, version=v)
          # first is for apple clang, second is for real gcc
          elif e.endswith('(use -v to see invocation)\n') or 'macosx_version' in e:
              if isinstance(prefix, str):
                  _, _, e = Popen_safe(compiler + [prefix + '-v'] + extra_args)
              else:
                  _, _, e = Popen_safe(compiler + prefix + ['-v'] + extra_args)
              i = 'APPLE ld'
              for line in e.split('\n'):
                  if 'PROJECT:ld' in line:
                      v = line.split('-')[1]
                      break
              else:
                  v = 'unknown version'
              linker = AppleDynamicLinker(compiler, for_machine, i, prefix, version=v)
          elif 'GNU' in o:
              if 'gold' in 'o':
                  i = 'GNU ld.gold'
              else:
                  i = 'GNU ld.bfd'
              linker = GnuDynamicLinker(compiler, for_machine, i, prefix, version=v)
          elif 'Solaris' in e or 'Solaris' in o:
              linker = SolarisDynamicLinker(
                  compiler, for_machine, 'solaris', prefix,
                  version=search_version(e))
          else:
              raise MesonException('Unable to determine dynamic linker.')
          return linker
  
      def _detect_c_or_cpp_compiler(self, lang: str, for_machine: MachineChoice) -> Compiler:
          popen_exceptions = {}
          compilers, ccache, exe_wrap = self._get_compilers(lang, for_machine)
          is_cross = not self.machines.matches_build_machine(for_machine)
  
          for compiler in compilers:
              if isinstance(compiler, str):
                  compiler = [compiler]
              if not set(['cl', 'cl.exe', 'clang-cl', 'clang-cl.exe']).isdisjoint(compiler):
                  # Watcom C provides it's own cl.exe clone that mimics an older
                  # version of Microsoft's compiler. Since Watcom's cl.exe is
                  # just a wrapper, we skip using it if we detect its presence
                  # so as not to confuse Meson when configuring for MSVC.
                  #
                  # Additionally the help text of Watcom's cl.exe is paged, and
                  # the binary will not exit without human intervention. In
                  # practice, Meson will block waiting for Watcom's cl.exe to
                  # exit, which requires user input and thus will never exit.
                  if 'WATCOM' in os.environ:
                      def sanitize(p):
                          return os.path.normcase(os.path.abspath(p))
  
                      watcom_cls = [sanitize(os.path.join(os.environ['WATCOM'], 'BINNT', 'cl')),
                                    sanitize(os.path.join(os.environ['WATCOM'], 'BINNT', 'cl.exe'))]
                      found_cl = sanitize(shutil.which('cl'))
                      if found_cl in watcom_cls:
                          continue
                  arg = '/?'
              elif 'armcc' in compiler[0]:
                  arg = '--vsn'
              elif 'ccrx' in compiler[0]:
                  arg = '-v'
              elif 'icl' in compiler[0]:
                  # if you pass anything to icl you get stuck in a pager
                  arg = ''
              else:
                  arg = '--version'
  
              try:
                  p, out, err = Popen_safe(compiler + [arg])
              except OSError as e:
                  popen_exceptions[' '.join(compiler + [arg])] = e
                  continue
  
              if 'ccrx' in compiler[0]:
                  out = err
  
              full_version = out.split('\n', 1)[0]
              version = search_version(out)
  
              guess_gcc_or_lcc = False
              if 'Free Software Foundation' in out or 'xt-' in out:
                  guess_gcc_or_lcc = 'gcc'
              if 'e2k' in out and 'lcc' in out:
                  guess_gcc_or_lcc = 'lcc'
  
              if guess_gcc_or_lcc:
                  defines = self.get_gnu_compiler_defines(compiler)
                  if not defines:
                      popen_exceptions[' '.join(compiler)] = 'no pre-processor defines'
                      continue
                  compiler_type = self.get_gnu_compiler_type(defines)
  
                  if guess_gcc_or_lcc == 'lcc':
                      version = self.get_lcc_version_from_defines(defines)
                      cls = ElbrusCCompiler if lang == 'c' else ElbrusCPPCompiler
                  else:
                      version = self.get_gnu_version_from_defines(defines)
                      cls = GnuCCompiler if lang == 'c' else GnuCPPCompiler
  
                  linker = self._guess_nix_linker(compiler, for_machine, cls.LINKER_PREFIX)
                  return cls(ccache + compiler, version, compiler_type,
                             for_machine, is_cross, exe_wrap, defines,
                             full_version=full_version, linker=linker)
  
              if 'Emscripten' in out:
                  cls = EmscriptenCCompiler if lang == 'c' else EmscriptenCPPCompiler
                  compiler_type = CompilerType.CLANG_EMSCRIPTEN
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version)
  
              if 'armclang' in out:
                  # The compiler version is not present in the first line of output,
                  # instead it is present in second line, startswith 'Component:'.
                  # So, searching for the 'Component' in out although we know it is
                  # present in second line, as we are not sure about the
                  # output format in future versions
                  arm_ver_str = re.search('.*Component.*', out)
                  if arm_ver_str is None:
                      popen_exceptions[' '.join(compiler)] = 'version string not found'
                      continue
                  arm_ver_str = arm_ver_str.group(0)
                  # Override previous values
                  version = search_version(arm_ver_str)
                  full_version = arm_ver_str
                  compiler_type = CompilerType.ARM_WIN
                  cls = ArmclangCCompiler if lang == 'c' else ArmclangCPPCompiler
                  linker = ArmClangDynamicLinker(for_machine, version=version)
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
              if 'CL.EXE COMPATIBILITY' in out:
                  # if this is clang-cl masquerading as cl, detect it as cl, not
                  # clang
                  arg = '--version'
                  try:
                      p, out, err = Popen_safe(compiler + [arg])
                  except OSError as e:
                      popen_exceptions[' '.join(compiler + [arg])] = e
                  version = search_version(out)
                  match = re.search('^Target: (.*?)-', out, re.MULTILINE)
                  if match:
                      target = match.group(1)
                  else:
                      target = 'unknown target'
                  cls = ClangClCCompiler if lang == 'c' else ClangClCPPCompiler
                  linker = ClangClDynamicLinker(for_machine, version=version)
                  return cls(compiler, version, for_machine, is_cross, exe_wrap, target, linker=linker)
              if 'clang' in out:
                  linker = None
                  cls = ClangCCompiler if lang == 'c' else ClangCPPCompiler
                  if 'Apple' in out or self.machines[for_machine].is_darwin():
                      compiler_type = CompilerType.CLANG_OSX
                  elif 'windows' in out or self.machines[for_machine].is_windows():
                      compiler_type = CompilerType.CLANG_MINGW
                      # If we're in a MINGW context this actually will use a gnu style ld
                      try:
                          linker = self._guess_win_linker(compiler, for_machine, cls.LINKER_PREFIX)
                      except MesonException:
                          pass
                  else:
                      compiler_type = CompilerType.CLANG_STANDARD
                  if linker is None:
                      linker = self._guess_nix_linker(compiler, for_machine, cls.LINKER_PREFIX)
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
              if 'Intel(R) C++ Intel(R)' in err:
                  version = search_version(err)
                  target = 'x86' if 'IA-32' in err else 'x86_64'
                  cls = IntelClCCompiler if lang == 'c' else IntelClCPPCompiler
                  linker = XilinkDynamicLinker(for_machine, version=version)
                  return cls(compiler, version, for_machine, is_cross, exe_wrap, target, linker=linker)
              if 'Microsoft' in out or 'Microsoft' in err:
                  # Latest versions of Visual Studio print version
                  # number to stderr but earlier ones print version
                  # on stdout.  Why? Lord only knows.
                  # Check both outputs to figure out version.
                  for lookat in [err, out]:
                      version = search_version(lookat)
                      if version != 'unknown version':
                          break
                  else:
                      m = 'Failed to detect MSVC compiler version: stderr was\n{!r}'
                      raise EnvironmentException(m.format(err))
                  match = re.search(' for .*(x86|x64|ARM|ARM64)$', lookat.split('\n')[0])
                  if match:
                      target = match.group(1)
                  else:
                      target = 'x86'
                  linker = MSVCDynamicLinker(for_machine, version=version)
                  cls = VisualStudioCCompiler if lang == 'c' else VisualStudioCPPCompiler
                  return cls(compiler, version, for_machine, is_cross, exe_wrap, target, linker=linker)
              if 'PGI Compilers' in out:
                  if self.machines[for_machine].is_darwin():
                      compiler_type = CompilerType.PGI_OSX
                  elif self.machines[for_machine].is_windows():
                      compiler_type = CompilerType.PGI_WIN
                  else:
                      compiler_type = CompilerType.PGI_STANDARD
                  cls = PGICCompiler if lang == 'c' else PGICPPCompiler
                  linker = PGIDynamicLinker(compiler, for_machine, 'pgi', cls.LINKER_PREFIX, version=version)
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, linker=linker)
              if '(ICC)' in out:
                  if self.machines[for_machine].is_darwin():
                      compiler_type = CompilerType.ICC_OSX
                      l = XildAppleDynamicLinker(compiler, for_machine, 'xild', '-Wl,', version=version)
                  else:
                      compiler_type = CompilerType.ICC_STANDARD
                      l = XildLinuxDynamicLinker(compiler, for_machine, 'xild', '-Wl,', version=version)
                  cls = IntelCCompiler if lang == 'c' else IntelCPPCompiler
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version, linker=l)
              if 'ARM' in out:
                  compiler_type = CompilerType.ARM_WIN
                  cls = ArmCCompiler if lang == 'c' else ArmCPPCompiler
                  linker = ArmDynamicLinker(for_machine, version=version)
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
              if 'RX Family' in out:
                  compiler_type = CompilerType.CCRX_WIN
                  cls = CcrxCCompiler if lang == 'c' else CcrxCPPCompiler
                  linker = CcrxDynamicLinker(for_machine, version=version)
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
          self._handle_exceptions(popen_exceptions, compilers)
  
      def detect_c_compiler(self, for_machine):
          return self._detect_c_or_cpp_compiler('c', for_machine)
  
      def detect_cpp_compiler(self, for_machine):
          return self._detect_c_or_cpp_compiler('cpp', for_machine)
  
      def detect_cuda_compiler(self, for_machine):
          popen_exceptions = {}
          is_cross = not self.machines.matches_build_machine(for_machine)
          compilers, ccache, exe_wrap = self._get_compilers('cuda', for_machine)
          for compiler in compilers:
              if isinstance(compiler, str):
                  compiler = [compiler]
              else:
                  raise EnvironmentException()
              arg = '--version'
              try:
                  p, out, err = Popen_safe(compiler + [arg])
              except OSError as e:
                  popen_exceptions[' '.join(compiler + [arg])] = e
                  continue
              # Example nvcc printout:
              #
              #     nvcc: NVIDIA (R) Cuda compiler driver
              #     Copyright (c) 2005-2018 NVIDIA Corporation
              #     Built on Sat_Aug_25_21:08:01_CDT_2018
              #     Cuda compilation tools, release 10.0, V10.0.130
              #
              # search_version() first finds the "10.0" after "release",
              # rather than the more precise "10.0.130" after "V".
              # The patch version number is occasionally important; For
              # instance, on Linux,
              #    - CUDA Toolkit 8.0.44 requires NVIDIA Driver 367.48
              #    - CUDA Toolkit 8.0.61 requires NVIDIA Driver 375.26
              # Luckily, the "V" also makes it very simple to extract
              # the full version:
              version = out.strip().split('V')[-1]
              cpp_compiler = self.detect_cpp_compiler(for_machine)
              linker = CudaLinker(compiler, for_machine, 'nvlink', CudaCompiler.LINKER_PREFIX, version=CudaLinker.parse_version())
              return CudaCompiler(ccache + compiler, version, for_machine, is_cross, exe_wrap, host_compiler=cpp_compiler, linker=linker)
          raise EnvironmentException('Could not find suitable CUDA compiler: "' + ' '.join(compilers) + '"')
  
      def detect_fortran_compiler(self, for_machine: MachineChoice):
          popen_exceptions = {}
          compilers, ccache, exe_wrap = self._get_compilers('fortran', for_machine)
          is_cross = not self.machines.matches_build_machine(for_machine)
          for compiler in compilers:
              if isinstance(compiler, str):
                  compiler = [compiler]
              for arg in ['--version', '-V']:
                  try:
                      p, out, err = Popen_safe(compiler + [arg])
                  except OSError as e:
                      popen_exceptions[' '.join(compiler + [arg])] = e
                      continue
  
                  version = search_version(out)
                  full_version = out.split('\n', 1)[0]
  
                  guess_gcc_or_lcc = False
                  if 'GNU Fortran' in out:
                      guess_gcc_or_lcc = 'gcc'
                  if 'e2k' in out and 'lcc' in out:
                      guess_gcc_or_lcc = 'lcc'
  
                  if guess_gcc_or_lcc:
                      defines = self.get_gnu_compiler_defines(compiler)
                      if not defines:
                          popen_exceptions[' '.join(compiler)] = 'no pre-processor defines'
                          continue
                      compiler_type = self.get_gnu_compiler_type(defines)
                      if guess_gcc_or_lcc == 'lcc':
                          version = self.get_lcc_version_from_defines(defines)
                          cls = ElbrusFortranCompiler
                      else:
                          version = self.get_gnu_version_from_defines(defines)
                          cls = GnuFortranCompiler
                      linker = self._guess_nix_linker(compiler, for_machine, cls.LINKER_PREFIX)
                      return cls(compiler, version, compiler_type, for_machine, is_cross, exe_wrap, defines, full_version=full_version, linker=linker)
  
                  if 'G95' in out:
                      linker = self._guess_nix_linker(compiler, for_machine, G95FortranCompiler.LINKER_PREFIX)
                      return G95FortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
                  if 'Sun Fortran' in err:
                      version = search_version(err)
                      linker = self._guess_nix_linker(compiler, for_machine, SunFortranCompiler.LINKER_PREFIX)
                      return SunFortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
                  if 'Intel(R) Visual Fortran' in err:
                      version = search_version(err)
                      target = 'x86' if 'IA-32' in err else 'x86_64'
                      linker = XilinkDynamicLinker(for_machine, version=version)
                      return IntelClFortranCompiler(compiler, version, for_machine, is_cross, target, exe_wrap, linker=linker)
  
                  if 'ifort (IFORT)' in out:
                      linker = XildLinuxDynamicLinker(compiler, for_machine, 'xild', '-Wl,', version=version)
                      return IntelFortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
                  if 'PathScale EKOPath(tm)' in err:
                      return PathScaleFortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version)
  
                  if 'PGI Compilers' in out:
                      if self.machines[for_machine].is_darwin():
                          compiler_type = CompilerType.PGI_OSX
                      elif self.machines[for_machine].is_windows():
                          compiler_type = CompilerType.PGI_WIN
                      else:
                          compiler_type = CompilerType.PGI_STANDARD
                      linker = PGIDynamicLinker(compiler, for_machine, 'pgi', PGIFortranCompiler.LINKER_PREFIX, version=version)
                      return PGIFortranCompiler(compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
                  if 'flang' in out or 'clang' in out:
                      linker = self._guess_nix_linker(compiler, for_machine, FlangFortranCompiler.LINKER_PREFIX)
                      return FlangFortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
                  if 'Open64 Compiler Suite' in err:
                      linker = self._guess_nix_linker(compiler, for_machine, Open64FortranCompiler.LINKER_PREFIX)
                      return Open64FortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
                  if 'NAG Fortran' in err:
                      linker = self._guess_nix_linker(compiler, for_machine, NAGFortranCompiler.LINKER_PREFIX)
                      return NAGFortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
          self._handle_exceptions(popen_exceptions, compilers)
  
      def get_scratch_dir(self):
          return self.scratch_dir
  
      def detect_objc_compiler(self, for_machine: MachineInfo) -> 'Compiler':
          return self._detect_objc_or_objcpp_compiler(for_machine, True)
  
      def detect_objcpp_compiler(self, for_machine: MachineInfo) -> 'Compiler':
          return self._detect_objc_or_objcpp_compiler(for_machine, False)
  
      def _detect_objc_or_objcpp_compiler(self, for_machine: MachineInfo, objc: bool) -> 'Compiler':
          popen_exceptions = {}
          compilers, ccache, exe_wrap = self._get_compilers('objc' if objc else 'objcpp', for_machine)
          is_cross = not self.machines.matches_build_machine(for_machine)
          for compiler in compilers:
              if isinstance(compiler, str):
                  compiler = [compiler]
              arg = ['--version']
              try:
                  p, out, err = Popen_safe(compiler + arg)
              except OSError as e:
                  popen_exceptions[' '.join(compiler + arg)] = e
                  continue
              version = search_version(out)
              if 'Free Software Foundation' in out or ('e2k' in out and 'lcc' in out):
                  defines = self.get_gnu_compiler_defines(compiler)
                  if not defines:
                      popen_exceptions[' '.join(compiler)] = 'no pre-processor defines'
                      continue
                  compiler_type = self.get_gnu_compiler_type(defines)
                  version = self.get_gnu_version_from_defines(defines)
                  comp = GnuObjCCompiler if objc else GnuObjCPPCompiler
                  linker = self._guess_nix_linker(compiler, for_machine, comp.LINKER_PREFIX)
                  return comp(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, defines, linker=linker)
              if 'clang' in out:
                  linker = None
                  comp = ClangObjCCompiler if objc else ClangObjCPPCompiler
                  if 'Apple' in out or self.machines[for_machine].is_darwin():
                      compiler_type = CompilerType.CLANG_OSX
                  elif 'windows' in out or self.machines[for_machine].is_windows():
                      compiler_type = CompilerType.CLANG_MINGW
                      # If we're in a MINGW context this actually will use a gnu style ld
                      try:
                          linker = self._guess_win_linker(compiler, for_machine, comp.LINKER_PREFIX)
                      except MesonException:
                          pass
                  else:
                      compiler_type = CompilerType.CLANG_STANDARD
                  if not linker:
                      linker = self._guess_nix_linker(compiler, for_machine, comp.LINKER_PREFIX)
                  return comp(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, linker=linker)
          self._handle_exceptions(popen_exceptions, compilers)
  
      def detect_java_compiler(self, for_machine):
          exelist = self.binaries.host.lookup_entry('java')
          if exelist is None:
              # TODO support fallback
              exelist = [self.default_java[0]]
  
          try:
              p, out, err = Popen_safe(exelist + ['-version'])
          except OSError:
              raise EnvironmentException('Could not execute Java compiler "%s"' % ' '.join(exelist))
          if 'javac' in out or 'javac' in err:
              version = search_version(err if 'javac' in err else out)
              if not version or version == 'unknown version':
                  parts = (err if 'javac' in err else out).split()
                  if len(parts) > 1:
                      version = parts[1]
              return JavaCompiler(exelist, version, for_machine)
          raise EnvironmentException('Unknown compiler "' + ' '.join(exelist) + '"')
  
      def detect_cs_compiler(self, for_machine):
          compilers, ccache, exe_wrap = self._get_compilers('cs', for_machine)
          popen_exceptions = {}
          for comp in compilers:
              if not isinstance(comp, list):
                  comp = [comp]
              try:
                  p, out, err = Popen_safe(comp + ['--version'])
              except OSError as e:
                  popen_exceptions[' '.join(comp + ['--version'])] = e
                  continue
  
              version = search_version(out)
              if 'Mono' in out:
                  return MonoCompiler(comp, version, for_machine)
              elif "Visual C#" in out:
                  return VisualStudioCsCompiler(comp, version, for_machine)
  
          self._handle_exceptions(popen_exceptions, compilers)
  
      def detect_vala_compiler(self, for_machine):
          exelist = self.binaries.host.lookup_entry('vala')
          is_cross = not self.machines.matches_build_machine(for_machine)
          if exelist is None:
              # TODO support fallback
              exelist = [self.default_vala[0]]
  
          try:
              p, out = Popen_safe(exelist + ['--version'])[0:2]
          except OSError:
              raise EnvironmentException('Could not execute Vala compiler "%s"' % ' '.join(exelist))
          version = search_version(out)
          if 'Vala' in out:
              return ValaCompiler(exelist, version, for_machine, is_cross)
          raise EnvironmentException('Unknown compiler "' + ' '.join(exelist) + '"')
  
      def detect_rust_compiler(self, for_machine):
          popen_exceptions = {}
          compilers, ccache, exe_wrap = self._get_compilers('rust', for_machine)
          is_cross = not self.machines.matches_build_machine(for_machine)
          for compiler in compilers:
              if isinstance(compiler, str):
                  compiler = [compiler]
              arg = ['--version']
              try:
                  p, out = Popen_safe(compiler + arg)[0:2]
              except OSError as e:
                  popen_exceptions[' '.join(compiler + arg)] = e
                  continue
  
              version = search_version(out)
  
              if 'rustc' in out:
                  # Chalk up another quirk for rust. There is no way (AFAICT) to
                  # figure out what linker rustc is using for a non-nightly compiler
                  # (On nightly you can pass -Z print-link-args). So we're going to
                  # hard code the linker based on the platform.
                  # Currenty gnu ld is used for everything except apple by
                  # default, and apple ld is used on mac.
                  # TODO: find some better way to figure this out.
                  if self.machines[for_machine].is_darwin():
                      linker = AppleDynamicLinker([], for_machine, 'Apple ld', '-Wl,')
                  else:
                      linker = GnuDynamicLinker([], for_machine, 'GNU ld', '-Wl,')
                  return RustCompiler(compiler, version, for_machine, is_cross, exe_wrap, linker=linker)
  
          self._handle_exceptions(popen_exceptions, compilers)
  
      def detect_d_compiler(self, for_machine: MachineChoice):
          exelist = self.binaries[for_machine].lookup_entry('d')
          # Search for a D compiler.
          # We prefer LDC over GDC unless overridden with the DC
          # environment variable because LDC has a much more
          # up to date language version at time (2016).
          if exelist is not None:
              if os.path.basename(exelist[-1]).startswith(('ldmd', 'gdmd')):
                  raise EnvironmentException(
                      'Meson does not support {} as it is only a DMD frontend for another compiler.'
                      'Please provide a valid value for DC or unset it so that Meson can resolve the compiler by itself.'.format(exelist[-1]))
          else:
              for d in self.default_d:
                  if shutil.which(d):
                      exelist = [d]
                      break
              else:
                  raise EnvironmentException('Could not find any supported D compiler.')
  
          try:
              p, out = Popen_safe(exelist + ['--version'])[0:2]
          except OSError:
              raise EnvironmentException('Could not execute D compiler "%s"' % ' '.join(exelist))
          version = search_version(out)
          full_version = out.split('\n', 1)[0]
  
          # Detect the target architecture, required for proper architecture handling on Windows.
          c_compiler = {}
          is_msvc = mesonlib.is_windows() and 'VCINSTALLDIR' in os.environ
          if is_msvc:
              c_compiler = {'c': self.detect_c_compiler(for_machine)} # MSVC compiler is required for correct platform detection.
  
          arch = detect_cpu_family(c_compiler)
          if is_msvc and arch == 'x86':
              arch = 'x86_mscoff'
  
          if 'LLVM D compiler' in out:
              # LDC seems to require a file
              m = self.machines[for_machine]
              if m.is_windows() or m.is_cygwin():
                  # Getting LDC on windows to give useful linker output when not
                  # doing real work is painfully hard. It ships with a verison of
                  # lld-link, so just assume that we're going to use lld-link
                  # with it.
                  _, o, _ = Popen_safe(['lld-link.exe', '--version'])
                  linker = ClangClDynamicLinker(for_machine, version=search_version(o))
              else:
                  with tempfile.NamedTemporaryFile(suffix='.d') as f:
                      linker = self._guess_nix_linker(
                          exelist, for_machine,
                          compilers.LLVMDCompiler.LINKER_PREFIX,
                          extra_args=[f.name])
              return compilers.LLVMDCompiler(exelist, version, for_machine, arch, full_version=full_version, linker=linker)
          elif 'gdc' in out:
              linker = self._guess_nix_linker(exelist, for_machine, compilers.GnuDCompiler.LINKER_PREFIX)
              return compilers.GnuDCompiler(exelist, version, for_machine, arch, full_version=full_version, linker=linker)
          elif 'The D Language Foundation' in out or 'Digital Mars' in out:
              # DMD seems to require a file
              m = self.machines[for_machine]
              if m.is_windows() or m.is_cygwin():
                  linker = OptlinkDynamicLinker(for_machine, version=full_version)
              else:
                  with tempfile.NamedTemporaryFile(suffix='.d') as f:
                      linker = self._guess_nix_linker(
                          exelist, for_machine,
                          compilers.LLVMDCompiler.LINKER_PREFIX,
                          extra_args=[f.name])
              return compilers.DmdDCompiler(exelist, version, for_machine, arch, full_version=full_version, linker=linker)
          raise EnvironmentException('Unknown compiler "' + ' '.join(exelist) + '"')
  
      def detect_swift_compiler(self, for_machine):
          exelist = self.binaries.host.lookup_entry('swift')
          is_cross = not self.machines.matches_build_machine(for_machine)
          if exelist is None:
              # TODO support fallback
              exelist = [self.default_swift[0]]
  
          try:
              p, _, err = Popen_safe(exelist + ['-v'])
          except OSError:
              raise EnvironmentException('Could not execute Swift compiler "%s"' % ' '.join(exelist))
          version = search_version(err)
          if 'Swift' in err:
              # As for 5.0.1 swiftc *requires* a file to check the linker:
              with tempfile.NamedTemporaryFile(suffix='.swift') as f:
                  linker = self._guess_nix_linker(
                      exelist, for_machine, compilers.SwiftCompiler.LINKER_PREFIX, extra_args=[f.name])
              return compilers.SwiftCompiler(exelist, version, for_machine, is_cross, linker=linker)
  
          raise EnvironmentException('Unknown compiler "' + ' '.join(exelist) + '"')
  
      def compiler_from_language(self, lang: str, for_machine: MachineChoice):
          if lang == 'c':
              comp = self.detect_c_compiler(for_machine)
          elif lang == 'cpp':
              comp = self.detect_cpp_compiler(for_machine)
          elif lang == 'objc':
              comp = self.detect_objc_compiler(for_machine)
          elif lang == 'cuda':
              comp = self.detect_cuda_compiler(for_machine)
          elif lang == 'objcpp':
              comp = self.detect_objcpp_compiler(for_machine)
          elif lang == 'java':
              comp = self.detect_java_compiler(for_machine)
          elif lang == 'cs':
              comp = self.detect_cs_compiler(for_machine)
          elif lang == 'vala':
              comp = self.detect_vala_compiler(for_machine)
          elif lang == 'd':
              comp = self.detect_d_compiler(for_machine)
          elif lang == 'rust':
              comp = self.detect_rust_compiler(for_machine)
          elif lang == 'fortran':
              comp = self.detect_fortran_compiler(for_machine)
          elif lang == 'swift':
              comp = self.detect_swift_compiler(for_machine)
          else:
              comp = None
          return comp
  
      def detect_compiler_for(self, lang: str, for_machine: MachineChoice):
          comp = self.compiler_from_language(lang, for_machine)
          if comp is not None:
              assert comp.for_machine == for_machine
              self.coredata.process_new_compiler(lang, comp, self)
          return comp
  
      def detect_static_linker(self, compiler):
          linker = self.binaries[compiler.for_machine].lookup_entry('ar')
          if linker is not None:
              linkers = [linker]
          else:
              evar = 'AR'
              defaults = [[l] for l in self.default_static_linker]
              if isinstance(compiler, compilers.CudaCompiler):
                  linkers = [self.cuda_static_linker] + defaults
              elif evar in os.environ:
                  linkers = [split_args(os.environ[evar])]
              elif isinstance(compiler, compilers.VisualStudioLikeCompiler):
                  linkers = [self.vs_static_linker, self.clang_cl_static_linker]
              elif isinstance(compiler, compilers.GnuCompiler):
                  # Use gcc-ar if available; needed for LTO
                  linkers = [self.gcc_static_linker] + defaults
              elif isinstance(compiler, compilers.ClangCompiler):
                  # Use llvm-ar if available; needed for LTO
                  linkers = [self.clang_static_linker] + defaults
              elif isinstance(compiler, compilers.DCompiler):
                  # Prefer static linkers over linkers used by D compilers
                  if mesonlib.is_windows():
                      linkers = [self.vs_static_linker, self.clang_cl_static_linker, compiler.get_linker_exelist()]
                  else:
                      linkers = defaults
              elif isinstance(compiler, IntelClCCompiler):
                  # Intel has it's own linker that acts like microsoft's lib
                  linkers = ['xilib']
              elif isinstance(compiler, (PGICCompiler, PGIFortranCompiler)) and mesonlib.is_windows():
                  linkers = [self.default_static_linker]  # this is just a wrapper calling link/lib on Windows, keeping things simple.
              else:
                  linkers = defaults
          popen_exceptions = {}
          for linker in linkers:
              if not {'lib', 'lib.exe', 'llvm-lib', 'llvm-lib.exe', 'xilib', 'xilib.exe'}.isdisjoint(linker):
                  arg = '/?'
              else:
                  arg = '--version'
              try:
                  p, out, err = Popen_safe(linker + [arg])
              except OSError as e:
                  popen_exceptions[' '.join(linker + [arg])] = e
                  continue
              if "xilib: executing 'lib'" in err:
                  return IntelVisualStudioLinker(linker, getattr(compiler, 'machine', None))
              if '/OUT:' in out.upper() or '/OUT:' in err.upper():
                  return VisualStudioLinker(linker, getattr(compiler, 'machine', None))
              if 'ar-Error-Unknown switch: --version' in err:
                  return PGIStaticLinker(linker)
              if p.returncode == 0 and ('armar' in linker or 'armar.exe' in linker):
                  return ArmarLinker(linker)
              if 'DMD32 D Compiler' in out or 'DMD64 D Compiler' in out:
                  return DLinker(linker, compiler.arch)
              if 'LDC - the LLVM D compiler' in out:
                  return DLinker(linker, compiler.arch)
              if 'GDC' in out and ' based on D ' in out:
                  return DLinker(linker, compiler.arch)
              if err.startswith('Renesas') and ('rlink' in linker or 'rlink.exe' in linker):
                  return CcrxLinker(linker)
              if p.returncode == 0:
                  return ArLinker(linker)
              if p.returncode == 1 and err.startswith('usage'): # OSX
                  return ArLinker(linker)
              if p.returncode == 1 and err.startswith('Usage'): # AIX
                  return ArLinker(linker)
              if p.returncode == 1 and err.startswith('ar: bad option: --'): # Solaris
                  return ArLinker(linker)
          self._handle_exceptions(popen_exceptions, linkers, 'linker')
          raise EnvironmentException('Unknown static linker "%s"' % ' '.join(linkers))
  
      def get_source_dir(self):
          return self.source_dir
  
      def get_build_dir(self):
          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_builtin_option('prefix')
  
      def get_libdir(self) -> str:
          return self.coredata.get_builtin_option('libdir')
  
      def get_libexecdir(self) -> str:
          return self.coredata.get_builtin_option('libexecdir')
  
      def get_bindir(self) -> str:
          return self.coredata.get_builtin_option('bindir')
  
      def get_includedir(self) -> str:
          return self.coredata.get_builtin_option('includedir')
  
      def get_mandir(self) -> str:
          return self.coredata.get_builtin_option('mandir')
  
      def get_datadir(self) -> str:
          return self.coredata.get_builtin_option('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):
          if not self.need_exe_wrapper():
              from .dependencies import EmptyExternalProgram
              return EmptyExternalProgram()
          return self.exe_wrapper
  
files: mesonbuild/environment.py
files: # Copyright 2012-2016 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 os, platform, re, sys, shutil, subprocess, typing
  import tempfile
  import shlex
  
  from . import coredata
  from .linkers import ArLinker, ArmarLinker, VisualStudioLinker, DLinker, CcrxLinker, IntelVisualStudioLinker
  from . import mesonlib
  from .mesonlib import (
      MesonException, EnvironmentException, MachineChoice, Popen_safe,
      PerMachineDefaultable, PerThreeMachineDefaultable, split_args, quote_arg
  )
  from . import mlog
  
  from .envconfig import (
      BinaryTable, Directories, MachineInfo, MesonConfigFile,
      Properties, known_cpu_families,
  )
  from . import compilers
  from .compilers import (
      Compiler,
      CompilerType,
      is_assembly,
      is_header,
      is_library,
      is_llvm_ir,
      is_object,
      is_source,
  )
  from .linkers import (
      AppleDynamicLinker,
      ArmClangDynamicLinker,
      ArmDynamicLinker,
      CcrxDynamicLinker,
      ClangClDynamicLinker,
      DynamicLinker,
      GnuDynamicLinker,
      LLVMDynamicLinker,
      MSVCDynamicLinker,
      OptlinkDynamicLinker,
      PGIDynamicLinker,
      PGIStaticLinker,
      SolarisDynamicLinker,
      XildAppleDynamicLinker,
      XildLinuxDynamicLinker,
      XilinkDynamicLinker,
      CudaLinker,
  )
  from functools import lru_cache
  from .compilers import (
      ArmCCompiler,
      ArmCPPCompiler,
      ArmclangCCompiler,
      ArmclangCPPCompiler,
      ClangCCompiler,
      ClangCPPCompiler,
      ClangObjCCompiler,
      ClangObjCPPCompiler,
      ClangClCCompiler,
      ClangClCPPCompiler,
      FlangFortranCompiler,
      G95FortranCompiler,
      GnuCCompiler,
      GnuCPPCompiler,
      GnuFortranCompiler,
      GnuObjCCompiler,
      GnuObjCPPCompiler,
      ElbrusCCompiler,
      ElbrusCPPCompiler,
      ElbrusFortranCompiler,
      EmscriptenCCompiler,
      EmscriptenCPPCompiler,
      IntelCCompiler,
      IntelClCCompiler,
      IntelCPPCompiler,
      IntelClCPPCompiler,
      IntelFortranCompiler,
      IntelClFortranCompiler,
      JavaCompiler,
      MonoCompiler,
      CudaCompiler,
      VisualStudioCsCompiler,
      NAGFortranCompiler,
      Open64FortranCompiler,
      PathScaleFortranCompiler,
      PGICCompiler,
      PGICPPCompiler,
      PGIFortranCompiler,
      RustCompiler,
      CcrxCCompiler,
      CcrxCPPCompiler,
      SunFortranCompiler,
      ValaCompiler,
      VisualStudioCCompiler,
      VisualStudioCPPCompiler,
  )
  
  build_filename = 'meson.build'
  
  CompilersDict = typing.Dict[str, Compiler]
  
  def detect_gcovr(min_version='3.3', new_rootdir_version='4.2', 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, mesonlib.version_compare(found, '>=' + new_rootdir_version)
      return None, None
  
  def find_coverage_tools():
      gcovr_exe, gcovr_new_rootdir = detect_gcovr()
  
      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_new_rootdir, lcov_exe, genhtml_exe
  
  def detect_ninja(version: str = '1.5', log: bool = False) -> str:
      env_ninja = os.environ.get('NINJA', None)
      for n in [env_ninja] if env_ninja else ['ninja', 'ninja-build', 'samu']:
          try:
              p, found = Popen_safe([n, '--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):
              n = shutil.which(n)
              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, quote_arg(n)))
              return n
  
  def detect_scanbuild():
      """ 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 = [
              'scan-build',  # base
              'scan-build-8',   'scan-build80',
              'scan-build-7',   'scan-build70',
              'scan-build-6.0', 'scan-build60',
              'scan-build-5.0', 'scan-build50',
              'scan-build-4.0', 'scan-build40',
              'scan-build-3.9', 'scan-build39',
              'scan-build-3.8', 'scan-build38',
              'scan-build-3.7', 'scan-build37',
              'scan-build-3.6', 'scan-build36',
              'scan-build-3.5', 'scan-build35',
              'scan-build-9',   'scan-build-devel',  # development snapshot
          ]
          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_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():
          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.startswith('arm') or trial.startswith('earm'):
          trial = 'arm'
      elif trial.startswith(('powerpc64', 'ppc64')):
          trial = 'ppc64'
      elif trial.startswith(('powerpc', 'ppc')):
          trial = 'ppc'
      elif trial == 'macppc':
          trial = 'ppc'
      elif trial in ('amd64', 'x64', 'i86pc'):
          trial = 'x86_64'
  
      # 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'
  
      if trial not in known_cpu_families:
          mlog.warning('Unknown CPU family {!r}, please report this at '
                       'https://github.com/mesonbuild/meson/issues/new with the'
                       'output of `uname -a` and `cat /proc/cpuinfo`'.format(trial))
  
      return trial
  
  def detect_cpu(compilers: CompilersDict):
      if mesonlib.is_windows():
          trial = detect_windows_arch(compilers)
      elif mesonlib.is_freebsd() or mesonlib.is_netbsd() or mesonlib.is_openbsd():
          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 == 'aarch64':
          # Same check as above for cpu_family
          if any_compiler_has_define(compilers, '__arm__'):
              trial = 'arm'
      elif trial.startswith('earm'):
          trial = 'arm'
      elif trial == 'e2k':
          # Make more precise CPU detection for Elbrus platform.
          trial = platform.processor().lower()
      # Add more quirks here as bugs are reported. Keep in sync with
      # detect_cpu_family() above.
      return trial
  
  def detect_system():
      system = platform.system().lower()
      if system.startswith('cygwin'):
          return 'cygwin'
      return system
  
  def detect_msys2_arch():
      if 'MSYSTEM_CARCH' in os.environ:
          return os.environ['MSYSTEM_CARCH']
      return None
  
  def detect_machine_info(compilers: typing.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'))
  
  def search_version(text):
      # Usually of the type 4.1.4 but compiler output may contain
      # stuff like this:
      # (Sourcery CodeBench Lite 2014.05-29) 4.8.3 20140320 (prerelease)
      # Limiting major version number to two digits seems to work
      # thus far. When we get to GCC 100, this will break, but
      # if we are still relevant when that happens, it can be
      # considered an achievement in itself.
      #
      # This regex is reaching magic levels. If it ever needs
      # to be updated, do not complexify but convert to something
      # saner instead.
      # We'll demystify it a bit with a verbose definition.
      version_regex = re.compile(r"""
      (?<!                # Zero-width negative lookbehind assertion
          (
              \d          # One digit
              | \.        # Or one period
          )               # One occurrence
      )
      # Following pattern must not follow a digit or period
      (
          \d{1,2}         # One or two digits
          (
              \.\d+       # Period and one or more digits
          )+              # One or more occurrences
          (
              -[a-zA-Z0-9]+   # Hyphen and one or more alphanumeric
          )?              # Zero or one occurrence
      )                   # One occurrence
      """, re.VERBOSE)
      match = version_regex.search(text)
      if match:
          return match.group(0)
      return 'unknown version'
  
  class Environment:
      private_dir = 'meson-private'
      log_dir = 'meson-logs'
      info_dir = 'meson-info'
  
      def __init__(self, source_dir, build_dir, options):
          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())
                  self.first_invocation = False
              except FileNotFoundError:
                  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()
  
          # Similar to coredata.compilers, but lower level in that there is no
          # meta data, only names/paths.
          binaries = PerMachineDefaultable()
  
          # Misc other properties about each machine.
          properties = PerMachineDefaultable()
  
          # Store paths for native and cross build files. There is no target
          # machine information here because nothing is installed for the target
          # architecture, just the build and host architectures
          paths = PerMachineDefaultable()
  
          ## 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()
  
          ## Read in native file(s) to override build machine configuration
  
          if self.coredata.config_files is not None:
              config = MesonConfigFile.from_config_parser(
                  coredata.load_configs(self.coredata.config_files))
              binaries.build = BinaryTable(config.get('binaries', {}))
              paths.build = Directories(**config.get('paths', {}))
  
          ## Read in cross file(s) to override host machine configuration
  
          if self.coredata.cross_files:
              config = MesonConfigFile.from_config_parser(
                  coredata.load_configs(self.coredata.cross_files))
              properties.host = Properties(config.get('properties', {}), False)
              binaries.host = BinaryTable(config.get('binaries', {}), False)
              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'])
              paths.host = Directories(**config.get('paths', {}))
  
          ## "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.paths = paths.default_missing()
  
          exe_wrapper = self.binaries.host.lookup_entry('exe_wrapper')
          if exe_wrapper is not None:
              from .dependencies import ExternalProgram
              self.exe_wrapper = ExternalProgram.from_bin_list(
                  self.binaries.host,
                  'exe_wrapper')
          else:
              self.exe_wrapper = None
  
          self.cmd_line_options = options.cmd_line_options.copy()
  
          # List of potential compilers.
          if mesonlib.is_windows():
              # Intel C and C++ compiler is icl on Windows, but icc and icpc elsewhere.
              # Search for icl before cl, since Intel "helpfully" provides a
              # cl.exe that returns *exactly the same thing* that microsofts
              # cl.exe does, and if icl is present, it's almost certainly what
              # you want.
              self.default_c = ['icl', 'cl', 'cc', 'gcc', 'clang', 'clang-cl', 'pgcc']
              # There is currently no pgc++ for Windows, only for  Mac and Linux.
              self.default_cpp = ['icl', 'cl', 'c++', 'g++', 'clang++', 'clang-cl']
              self.default_fortran = ['ifort', 'gfortran', 'flang', 'pgfortran', 'g95']
              # Clang and clang++ are valid, but currently unsupported.
              self.default_objc = ['cc', 'gcc']
              self.default_objcpp = ['c++', 'g++']
              self.default_cs = ['csc', 'mcs']
          else:
              self.default_c = ['cc', 'gcc', 'clang', 'pgcc', 'icc']
              self.default_cpp = ['c++', 'g++', 'clang++', 'pgc++', 'icpc']
              self.default_fortran = ['gfortran', 'flang', 'pgfortran', 'ifort', 'g95']
              self.default_objc = ['cc', 'gcc', 'clang']
              self.default_objcpp = ['c++', 'g++', 'clang++']
              self.default_cs = ['mcs', 'csc']
          self.default_d = ['ldc2', 'ldc', 'gdc', 'dmd']
          self.default_java = ['javac']
          self.default_cuda = ['nvcc']
          self.default_rust = ['rustc']
          self.default_swift = ['swiftc']
          self.default_vala = ['valac']
          self.default_static_linker = ['ar', 'gar']
          self.default_strip = ['strip']
          self.vs_static_linker = ['lib']
          self.clang_cl_static_linker = ['llvm-lib']
          self.cuda_static_linker = ['nvlink']
          self.gcc_static_linker = ['gcc-ar']
          self.clang_static_linker = ['llvm-ar']
          self.default_cmake = ['cmake']
          self.default_pkgconfig = ['pkg-config']
  
      def create_new_coredata(self, options):
          # WARNING: Don't use any values from coredata in __init__. It gets
          # re-initialized with project options by the interpreter during
          # build file parsing.
          self.coredata = coredata.CoreData(options, self.scratch_dir)
          # Used by the regenchecker script, which runs meson
          self.coredata.meson_command = mesonlib.meson_command
          self.first_invocation = True
  
      def is_cross_build(self) -> bool:
          return not self.machines.matches_build_machine(MachineChoice.HOST)
  
      def dump_coredata(self):
          return coredata.save(self.coredata, self.get_build_dir())
  
      def get_script_dir(self):
          import mesonbuild.scripts
          return os.path.dirname(mesonbuild.scripts.__file__)
  
      def get_log_dir(self):
          return self.log_dir
  
      def get_coredata(self):
          return self.coredata
  
      def get_build_command(self, unbuffered=False):
          cmd = mesonlib.meson_command[:]
          if unbuffered and 'python' in os.path.basename(cmd[0]):
              cmd.insert(1, '-u')
          return cmd
  
      def is_header(self, fname):
          return is_header(fname)
  
      def is_source(self, fname):
          return is_source(fname)
  
      def is_assembly(self, fname):
          return is_assembly(fname)
  
      def is_llvm_ir(self, fname):
          return is_llvm_ir(fname)
  
      def is_object(self, fname):
          return is_object(fname)
  
      @lru_cache(maxsize=None)
      def is_library(self, fname):
          return is_library(fname)
  
      @staticmethod
      def get_gnu_compiler_defines(compiler):
          """
          Detect GNU compiler platform type (Apple, MinGW, Unix)
          """
          # Arguments to output compiler pre-processor defines to stdout
          # gcc, g++, and gfortran all support these arguments
          args = compiler + ['-E', '-dM', '-']
          p, output, error = Popen_safe(args, write='', stdin=subprocess.PIPE)
          if p.returncode != 0:
              raise EnvironmentException('Unable to detect GNU compiler type:\n' + output + error)
          # Parse several lines of the type:
          # `#define ___SOME_DEF some_value`
          # and extract `___SOME_DEF`
          defines = {}
          for line in output.split('\n'):
              if not line:
                  continue
              d, *rest = line.split(' ', 2)
              if d != '#define':
                  continue
              if len(rest) == 1:
                  defines[rest] = True
              if len(rest) == 2:
                  defines[rest[0]] = rest[1]
          return defines
  
      @staticmethod
      def get_gnu_version_from_defines(defines):
          dot = '.'
          major = defines.get('__GNUC__', '0')
          minor = defines.get('__GNUC_MINOR__', '0')
          patch = defines.get('__GNUC_PATCHLEVEL__', '0')
          return dot.join((major, minor, patch))
  
      @staticmethod
      def get_lcc_version_from_defines(defines):
          dot = '.'
          generation_and_major = defines.get('__LCC__', '100')
          generation = generation_and_major[:1]
          major = generation_and_major[1:]
          minor = defines.get('__LCC_MINOR__', '0')
          return dot.join((generation, major, minor))
  
      @staticmethod
      def get_gnu_compiler_type(defines):
          # Detect GCC type (Apple, MinGW, Cygwin, Unix)
          if '__APPLE__' in defines:
              return CompilerType.GCC_OSX
          elif '__MINGW32__' in defines or '__MINGW64__' in defines:
              return CompilerType.GCC_MINGW
          elif '__CYGWIN__' in defines:
              return CompilerType.GCC_CYGWIN
          return CompilerType.GCC_STANDARD
  
      def _get_compilers(self, lang, for_machine):
          '''
          The list of compilers is detected in the exact same way for
          C, C++, ObjC, ObjC++, Fortran, CS so consolidate it here.
          '''
          value = self.binaries[for_machine].lookup_entry(lang)
          if value is not None:
              compilers, ccache = BinaryTable.parse_entry(value)
              # Return value has to be a list of compiler 'choices'
              compilers = [compilers]
          else:
              if not self.machines.matches_build_machine(for_machine):
                  raise EnvironmentException('{!r} compiler binary not defined in cross or native file'.format(lang))
              compilers = getattr(self, 'default_' + lang)
              ccache = BinaryTable.detect_ccache()
  
          if self.machines.matches_build_machine(for_machine):
              exe_wrap = None
          else:
              exe_wrap = self.get_exe_wrapper()
  
          return compilers, ccache, exe_wrap
  
      def _handle_exceptions(self, exceptions, binaries, bintype='compiler'):
          errmsg = 'Unknown {}(s): {}'.format(bintype, binaries)
          if exceptions:
              errmsg += '\nThe follow exceptions were encountered:'
              for (c, e) in exceptions.items():
                  errmsg += '\nRunning "{0}" gave "{1}"'.format(c, e)
          raise EnvironmentException(errmsg)
  
      @staticmethod
      def _guess_win_linker(compiler: typing.List[str], for_machine: MachineChoice,
                            prefix: typing.Union[str, typing.List[str]]) -> 'DynamicLinker':
          # Explicitly pass logo here so that we can get the version of link.exe
          if isinstance(prefix, str):
              check_args = [prefix + '/logo', prefix + '--version']
          else:
              check_args = prefix + ['/logo'] + prefix + ['--version']
          p, o, _ = Popen_safe(compiler + check_args)
          if o.startswith('LLD'):
              if '(compatible with GNU linkers)' in o:
                  return LLVMDynamicLinker(compiler, for_machine, 'lld', prefix, version=search_version(o))
              else:
                  return ClangClDynamicLinker(for_machine, exelist=compiler, prefix=prefix, version=search_version(o))
          elif o.startswith('Microsoft'):
              match = re.search(r'.*(X86|X64|ARM|ARM64).*', o)
              if match:
                  target = str(match.group(1))
              else:
                  target = 'x86'
              return MSVCDynamicLinker(
                  for_machine, machine=target, exelist=compiler, prefix=prefix,
                  version=search_version(o))
          raise MesonException('Cannot guess dynamic linker')
  
      @staticmethod
      def _guess_nix_linker(compiler: typing.List[str], for_machine: MachineChoice,
                            prefix: typing.Union[str, typing.List[str]], *,
                            extra_args: typing.Optional[typing.List[str]] = None) -> 'DynamicLinker':
          """Helper for guessing what linker to use on Unix-Like OSes.
  
          :prefix: The prefix that the compiler uses to proxy arguments to the
              linker, if required. This can be passed as a string or a list of
              strings. If it is passed as a string then the arguments to be
              proxied to the linker will be concatenated, if it is a list they
              will be appended. This means that if a space is required (such as
              with swift which wants `-Xlinker --version` and *not*
              `-Xlinker=--version`) you must pass as a list.
          :extra_args: Any addtional arguments rquired (such as a source file)
          """
          extra_args = typing.cast(typing.List[str], extra_args or [])
          if isinstance(prefix, str):
              check_args = [prefix + '--version'] + extra_args
          else:
              check_args = prefix + ['--version'] + extra_args
          _, o, e = Popen_safe(compiler + check_args)
          v = search_version(o)
          if o.startswith('LLD'):
              linker = LLVMDynamicLinker(compiler, for_machine, 'lld', prefix, version=v)  # type: DynamicLinker
          elif e.startswith('lld-link: '):
              # Toolchain wrapper got in the way; this happens with e.g. https://github.com/mstorsjo/llvm-mingw
              # Let's try to extract the linker invocation command to grab the version.
  
              _, o, e = Popen_safe(compiler + check_args + ['-v'])
  
              try:
                  linker_cmd = re.match(r'.*\n(.*?)\nlld-link: ', e, re.DOTALL).group(1)
                  linker_cmd = shlex.split(linker_cmd)[0]
              except (AttributeError, IndexError, ValueError):
                  pass
              else:
                  _, o, e = Popen_safe([linker_cmd, '--version'])
                  v = search_version(o)
  
              linker = LLVMDynamicLinker(compiler, for_machine, 'lld', prefix, version=v)
          # first is for apple clang, second is for real gcc
          elif e.endswith('(use -v to see invocation)\n') or 'macosx_version' in e:
              if isinstance(prefix, str):
                  _, _, e = Popen_safe(compiler + [prefix + '-v'] + extra_args)
              else:
                  _, _, e = Popen_safe(compiler + prefix + ['-v'] + extra_args)
              i = 'APPLE ld'
              for line in e.split('\n'):
                  if 'PROJECT:ld' in line:
                      v = line.split('-')[1]
                      break
              else:
                  v = 'unknown version'
              linker = AppleDynamicLinker(compiler, for_machine, i, prefix, version=v)
          elif 'GNU' in o:
              if 'gold' in 'o':
                  i = 'GNU ld.gold'
              else:
                  i = 'GNU ld.bfd'
              linker = GnuDynamicLinker(compiler, for_machine, i, prefix, version=v)
          elif 'Solaris' in e or 'Solaris' in o:
              linker = SolarisDynamicLinker(
                  compiler, for_machine, 'solaris', prefix,
                  version=search_version(e))
          else:
              raise MesonException('Unable to determine dynamic linker.')
          return linker
  
      def _detect_c_or_cpp_compiler(self, lang: str, for_machine: MachineChoice) -> Compiler:
          popen_exceptions = {}
          compilers, ccache, exe_wrap = self._get_compilers(lang, for_machine)
          is_cross = not self.machines.matches_build_machine(for_machine)
  
          for compiler in compilers:
              if isinstance(compiler, str):
                  compiler = [compiler]
              if not set(['cl', 'cl.exe', 'clang-cl', 'clang-cl.exe']).isdisjoint(compiler):
                  # Watcom C provides it's own cl.exe clone that mimics an older
                  # version of Microsoft's compiler. Since Watcom's cl.exe is
                  # just a wrapper, we skip using it if we detect its presence
                  # so as not to confuse Meson when configuring for MSVC.
                  #
                  # Additionally the help text of Watcom's cl.exe is paged, and
                  # the binary will not exit without human intervention. In
                  # practice, Meson will block waiting for Watcom's cl.exe to
                  # exit, which requires user input and thus will never exit.
                  if 'WATCOM' in os.environ:
                      def sanitize(p):
                          return os.path.normcase(os.path.abspath(p))
  
                      watcom_cls = [sanitize(os.path.join(os.environ['WATCOM'], 'BINNT', 'cl')),
                                    sanitize(os.path.join(os.environ['WATCOM'], 'BINNT', 'cl.exe'))]
                      found_cl = sanitize(shutil.which('cl'))
                      if found_cl in watcom_cls:
                          continue
                  arg = '/?'
              elif 'armcc' in compiler[0]:
                  arg = '--vsn'
              elif 'ccrx' in compiler[0]:
                  arg = '-v'
              elif 'icl' in compiler[0]:
                  # if you pass anything to icl you get stuck in a pager
                  arg = ''
              else:
                  arg = '--version'
  
              try:
                  p, out, err = Popen_safe(compiler + [arg])
              except OSError as e:
                  popen_exceptions[' '.join(compiler + [arg])] = e
                  continue
  
              if 'ccrx' in compiler[0]:
                  out = err
  
              full_version = out.split('\n', 1)[0]
              version = search_version(out)
  
              guess_gcc_or_lcc = False
              if 'Free Software Foundation' in out or 'xt-' in out:
                  guess_gcc_or_lcc = 'gcc'
              if 'e2k' in out and 'lcc' in out:
                  guess_gcc_or_lcc = 'lcc'
  
              if guess_gcc_or_lcc:
                  defines = self.get_gnu_compiler_defines(compiler)
                  if not defines:
                      popen_exceptions[' '.join(compiler)] = 'no pre-processor defines'
                      continue
                  compiler_type = self.get_gnu_compiler_type(defines)
  
                  if guess_gcc_or_lcc == 'lcc':
                      version = self.get_lcc_version_from_defines(defines)
                      cls = ElbrusCCompiler if lang == 'c' else ElbrusCPPCompiler
                  else:
                      version = self.get_gnu_version_from_defines(defines)
                      cls = GnuCCompiler if lang == 'c' else GnuCPPCompiler
  
                  linker = self._guess_nix_linker(compiler, for_machine, cls.LINKER_PREFIX)
                  return cls(ccache + compiler, version, compiler_type,
                             for_machine, is_cross, exe_wrap, defines,
                             full_version=full_version, linker=linker)
  
              if 'Emscripten' in out:
                  cls = EmscriptenCCompiler if lang == 'c' else EmscriptenCPPCompiler
                  compiler_type = CompilerType.CLANG_EMSCRIPTEN
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version)
  
              if 'armclang' in out:
                  # The compiler version is not present in the first line of output,
                  # instead it is present in second line, startswith 'Component:'.
                  # So, searching for the 'Component' in out although we know it is
                  # present in second line, as we are not sure about the
                  # output format in future versions
                  arm_ver_str = re.search('.*Component.*', out)
                  if arm_ver_str is None:
                      popen_exceptions[' '.join(compiler)] = 'version string not found'
                      continue
                  arm_ver_str = arm_ver_str.group(0)
                  # Override previous values
                  version = search_version(arm_ver_str)
                  full_version = arm_ver_str
                  compiler_type = CompilerType.ARM_WIN
                  cls = ArmclangCCompiler if lang == 'c' else ArmclangCPPCompiler
                  linker = ArmClangDynamicLinker(for_machine, version=version)
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
              if 'CL.EXE COMPATIBILITY' in out:
                  # if this is clang-cl masquerading as cl, detect it as cl, not
                  # clang
                  arg = '--version'
                  try:
                      p, out, err = Popen_safe(compiler + [arg])
                  except OSError as e:
                      popen_exceptions[' '.join(compiler + [arg])] = e
                  version = search_version(out)
                  match = re.search('^Target: (.*?)-', out, re.MULTILINE)
                  if match:
                      target = match.group(1)
                  else:
                      target = 'unknown target'
                  cls = ClangClCCompiler if lang == 'c' else ClangClCPPCompiler
                  linker = ClangClDynamicLinker(for_machine, version=version)
                  return cls(compiler, version, for_machine, is_cross, exe_wrap, target, linker=linker)
              if 'clang' in out:
                  linker = None
                  cls = ClangCCompiler if lang == 'c' else ClangCPPCompiler
                  if 'Apple' in out or self.machines[for_machine].is_darwin():
                      compiler_type = CompilerType.CLANG_OSX
                  elif 'windows' in out or self.machines[for_machine].is_windows():
                      compiler_type = CompilerType.CLANG_MINGW
                      # If we're in a MINGW context this actually will use a gnu style ld
                      try:
                          linker = self._guess_win_linker(compiler, for_machine, cls.LINKER_PREFIX)
                      except MesonException:
                          pass
                  else:
                      compiler_type = CompilerType.CLANG_STANDARD
                  if linker is None:
                      linker = self._guess_nix_linker(compiler, for_machine, cls.LINKER_PREFIX)
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
              if 'Intel(R) C++ Intel(R)' in err:
                  version = search_version(err)
                  target = 'x86' if 'IA-32' in err else 'x86_64'
                  cls = IntelClCCompiler if lang == 'c' else IntelClCPPCompiler
                  linker = XilinkDynamicLinker(for_machine, version=version)
                  return cls(compiler, version, for_machine, is_cross, exe_wrap, target, linker=linker)
              if 'Microsoft' in out or 'Microsoft' in err:
                  # Latest versions of Visual Studio print version
                  # number to stderr but earlier ones print version
                  # on stdout.  Why? Lord only knows.
                  # Check both outputs to figure out version.
                  for lookat in [err, out]:
                      version = search_version(lookat)
                      if version != 'unknown version':
                          break
                  else:
                      m = 'Failed to detect MSVC compiler version: stderr was\n{!r}'
                      raise EnvironmentException(m.format(err))
                  match = re.search(' for .*(x86|x64|ARM|ARM64)$', lookat.split('\n')[0])
                  if match:
                      target = match.group(1)
                  else:
                      target = 'x86'
                  linker = MSVCDynamicLinker(for_machine, version=version)
                  cls = VisualStudioCCompiler if lang == 'c' else VisualStudioCPPCompiler
                  return cls(compiler, version, for_machine, is_cross, exe_wrap, target, linker=linker)
              if 'PGI Compilers' in out:
                  if self.machines[for_machine].is_darwin():
                      compiler_type = CompilerType.PGI_OSX
                  elif self.machines[for_machine].is_windows():
                      compiler_type = CompilerType.PGI_WIN
                  else:
                      compiler_type = CompilerType.PGI_STANDARD
                  cls = PGICCompiler if lang == 'c' else PGICPPCompiler
                  linker = PGIDynamicLinker(compiler, for_machine, 'pgi', cls.LINKER_PREFIX, version=version)
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, linker=linker)
              if '(ICC)' in out:
                  if self.machines[for_machine].is_darwin():
                      compiler_type = CompilerType.ICC_OSX
                      l = XildAppleDynamicLinker(compiler, for_machine, 'xild', '-Wl,', version=version)
                  else:
                      compiler_type = CompilerType.ICC_STANDARD
                      l = XildLinuxDynamicLinker(compiler, for_machine, 'xild', '-Wl,', version=version)
                  cls = IntelCCompiler if lang == 'c' else IntelCPPCompiler
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version, linker=l)
              if 'ARM' in out:
                  compiler_type = CompilerType.ARM_WIN
                  cls = ArmCCompiler if lang == 'c' else ArmCPPCompiler
                  linker = ArmDynamicLinker(for_machine, version=version)
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
              if 'RX Family' in out:
                  compiler_type = CompilerType.CCRX_WIN
                  cls = CcrxCCompiler if lang == 'c' else CcrxCPPCompiler
                  linker = CcrxDynamicLinker(for_machine, version=version)
                  return cls(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
          self._handle_exceptions(popen_exceptions, compilers)
  
      def detect_c_compiler(self, for_machine):
          return self._detect_c_or_cpp_compiler('c', for_machine)
  
      def detect_cpp_compiler(self, for_machine):
          return self._detect_c_or_cpp_compiler('cpp', for_machine)
  
      def detect_cuda_compiler(self, for_machine):
          popen_exceptions = {}
          is_cross = not self.machines.matches_build_machine(for_machine)
          compilers, ccache, exe_wrap = self._get_compilers('cuda', for_machine)
          for compiler in compilers:
              if isinstance(compiler, str):
                  compiler = [compiler]
              else:
                  raise EnvironmentException()
              arg = '--version'
              try:
                  p, out, err = Popen_safe(compiler + [arg])
              except OSError as e:
                  popen_exceptions[' '.join(compiler + [arg])] = e
                  continue
              # Example nvcc printout:
              #
              #     nvcc: NVIDIA (R) Cuda compiler driver
              #     Copyright (c) 2005-2018 NVIDIA Corporation
              #     Built on Sat_Aug_25_21:08:01_CDT_2018
              #     Cuda compilation tools, release 10.0, V10.0.130
              #
              # search_version() first finds the "10.0" after "release",
              # rather than the more precise "10.0.130" after "V".
              # The patch version number is occasionally important; For
              # instance, on Linux,
              #    - CUDA Toolkit 8.0.44 requires NVIDIA Driver 367.48
              #    - CUDA Toolkit 8.0.61 requires NVIDIA Driver 375.26
              # Luckily, the "V" also makes it very simple to extract
              # the full version:
              version = out.strip().split('V')[-1]
              cpp_compiler = self.detect_cpp_compiler(for_machine)
              linker = CudaLinker(compiler, for_machine, 'nvlink', CudaCompiler.LINKER_PREFIX, version=CudaLinker.parse_version())
              return CudaCompiler(ccache + compiler, version, for_machine, is_cross, exe_wrap, host_compiler=cpp_compiler, linker=linker)
          raise EnvironmentException('Could not find suitable CUDA compiler: "' + ' '.join(compilers) + '"')
  
      def detect_fortran_compiler(self, for_machine: MachineChoice):
          popen_exceptions = {}
          compilers, ccache, exe_wrap = self._get_compilers('fortran', for_machine)
          is_cross = not self.machines.matches_build_machine(for_machine)
          for compiler in compilers:
              if isinstance(compiler, str):
                  compiler = [compiler]
              for arg in ['--version', '-V']:
                  try:
                      p, out, err = Popen_safe(compiler + [arg])
                  except OSError as e:
                      popen_exceptions[' '.join(compiler + [arg])] = e
                      continue
  
                  version = search_version(out)
                  full_version = out.split('\n', 1)[0]
  
                  guess_gcc_or_lcc = False
                  if 'GNU Fortran' in out:
                      guess_gcc_or_lcc = 'gcc'
                  if 'e2k' in out and 'lcc' in out:
                      guess_gcc_or_lcc = 'lcc'
  
                  if guess_gcc_or_lcc:
                      defines = self.get_gnu_compiler_defines(compiler)
                      if not defines:
                          popen_exceptions[' '.join(compiler)] = 'no pre-processor defines'
                          continue
                      compiler_type = self.get_gnu_compiler_type(defines)
                      if guess_gcc_or_lcc == 'lcc':
                          version = self.get_lcc_version_from_defines(defines)
                          cls = ElbrusFortranCompiler
                      else:
                          version = self.get_gnu_version_from_defines(defines)
                          cls = GnuFortranCompiler
                      linker = self._guess_nix_linker(compiler, for_machine, cls.LINKER_PREFIX)
                      return cls(compiler, version, compiler_type, for_machine, is_cross, exe_wrap, defines, full_version=full_version, linker=linker)
  
                  if 'G95' in out:
                      linker = self._guess_nix_linker(compiler, for_machine, G95FortranCompiler.LINKER_PREFIX)
                      return G95FortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
                  if 'Sun Fortran' in err:
                      version = search_version(err)
                      linker = self._guess_nix_linker(compiler, for_machine, SunFortranCompiler.LINKER_PREFIX)
                      return SunFortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
                  if 'Intel(R) Visual Fortran' in err:
                      version = search_version(err)
                      target = 'x86' if 'IA-32' in err else 'x86_64'
                      linker = XilinkDynamicLinker(for_machine, version=version)
                      return IntelClFortranCompiler(compiler, version, for_machine, is_cross, target, exe_wrap, linker=linker)
  
                  if 'ifort (IFORT)' in out:
                      linker = XildLinuxDynamicLinker(compiler, for_machine, 'xild', '-Wl,', version=version)
                      return IntelFortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
                  if 'PathScale EKOPath(tm)' in err:
                      return PathScaleFortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version)
  
                  if 'PGI Compilers' in out:
                      if self.machines[for_machine].is_darwin():
                          compiler_type = CompilerType.PGI_OSX
                      elif self.machines[for_machine].is_windows():
                          compiler_type = CompilerType.PGI_WIN
                      else:
                          compiler_type = CompilerType.PGI_STANDARD
                      linker = PGIDynamicLinker(compiler, for_machine, 'pgi', PGIFortranCompiler.LINKER_PREFIX, version=version)
                      return PGIFortranCompiler(compiler, version, compiler_type, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
                  if 'flang' in out or 'clang' in out:
                      linker = self._guess_nix_linker(compiler, for_machine, FlangFortranCompiler.LINKER_PREFIX)
                      return FlangFortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
                  if 'Open64 Compiler Suite' in err:
                      linker = self._guess_nix_linker(compiler, for_machine, Open64FortranCompiler.LINKER_PREFIX)
                      return Open64FortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
  
                  if 'NAG Fortran' in err:
                      linker = self._guess_nix_linker(compiler, for_machine, NAGFortranCompiler.LINKER_PREFIX)
                      return NAGFortranCompiler(compiler, version, for_machine, is_cross, exe_wrap, full_version=full_version, linker=linker)
          self._handle_exceptions(popen_exceptions, compilers)
  
      def get_scratch_dir(self):
          return self.scratch_dir
  
      def detect_objc_compiler(self, for_machine: MachineInfo) -> 'Compiler':
          return self._detect_objc_or_objcpp_compiler(for_machine, True)
  
      def detect_objcpp_compiler(self, for_machine: MachineInfo) -> 'Compiler':
          return self._detect_objc_or_objcpp_compiler(for_machine, False)
  
      def _detect_objc_or_objcpp_compiler(self, for_machine: MachineInfo, objc: bool) -> 'Compiler':
          popen_exceptions = {}
          compilers, ccache, exe_wrap = self._get_compilers('objc' if objc else 'objcpp', for_machine)
          is_cross = not self.machines.matches_build_machine(for_machine)
          for compiler in compilers:
              if isinstance(compiler, str):
                  compiler = [compiler]
              arg = ['--version']
              try:
                  p, out, err = Popen_safe(compiler + arg)
              except OSError as e:
                  popen_exceptions[' '.join(compiler + arg)] = e
                  continue
              version = search_version(out)
              if 'Free Software Foundation' in out or ('e2k' in out and 'lcc' in out):
                  defines = self.get_gnu_compiler_defines(compiler)
                  if not defines:
                      popen_exceptions[' '.join(compiler)] = 'no pre-processor defines'
                      continue
                  compiler_type = self.get_gnu_compiler_type(defines)
                  version = self.get_gnu_version_from_defines(defines)
                  comp = GnuObjCCompiler if objc else GnuObjCPPCompiler
                  linker = self._guess_nix_linker(compiler, for_machine, comp.LINKER_PREFIX)
                  return comp(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, defines, linker=linker)
              if 'clang' in out:
                  linker = None
                  comp = ClangObjCCompiler if objc else ClangObjCPPCompiler
                  if 'Apple' in out or self.machines[for_machine].is_darwin():
                      compiler_type = CompilerType.CLANG_OSX
                  elif 'windows' in out or self.machines[for_machine].is_windows():
                      compiler_type = CompilerType.CLANG_MINGW
                      # If we're in a MINGW context this actually will use a gnu style ld
                      try:
                          linker = self._guess_win_linker(compiler, for_machine, comp.LINKER_PREFIX)
                      except MesonException:
                          pass
                  else:
                      compiler_type = CompilerType.CLANG_STANDARD
                  if not linker:
                      linker = self._guess_nix_linker(compiler, for_machine, comp.LINKER_PREFIX)
                  return comp(ccache + compiler, version, compiler_type, for_machine, is_cross, exe_wrap, linker=linker)
          self._handle_exceptions(popen_exceptions, compilers)
  
      def detect_java_compiler(self, for_machine):
          exelist = self.binaries.host.lookup_entry('java')
          if exelist is None:
              # TODO support fallback
              exelist = [self.default_java[0]]
  
          try:
              p, out, err = Popen_safe(exelist + ['-version'])
          except OSError:
              raise EnvironmentException('Could not execute Java compiler "%s"' % ' '.join(exelist))
          if 'javac' in out or 'javac' in err:
              version = search_version(err if 'javac' in err else out)
              if not version or version == 'unknown version':
                  parts = (err if 'javac' in err else out).split()
                  if len(parts) > 1:
                      version = parts[1]
              return JavaCompiler(exelist, version, for_machine)
          raise EnvironmentException('Unknown compiler "' + ' '.join(exelist) + '"')
  
      def detect_cs_compiler(self, for_machine):
          compilers, ccache, exe_wrap = self._get_compilers('cs', for_machine)
          popen_exceptions = {}
          for comp in compilers:
              if not isinstance(comp, list):
                  comp = [comp]
              try:
                  p, out, err = Popen_safe(comp + ['--version'])
              except OSError as e:
                  popen_exceptions[' '.join(comp + ['--version'])] = e
                  continue
  
              version = search_version(out)
              if 'Mono' in out:
                  return MonoCompiler(comp, version, for_machine)
              elif "Visual C#" in out:
                  return VisualStudioCsCompiler(comp, version, for_machine)
  
          self._handle_exceptions(popen_exceptions, compilers)
  
      def detect_vala_compiler(self, for_machine):
          exelist = self.binaries.host.lookup_entry('vala')
          is_cross = not self.machines.matches_build_machine(for_machine)
          if exelist is None:
              # TODO support fallback
              exelist = [self.default_vala[0]]
  
          try:
              p, out = Popen_safe(exelist + ['--version'])[0:2]
          except OSError:
              raise EnvironmentException('Could not execute Vala compiler "%s"' % ' '.join(exelist))
          version = search_version(out)
          if 'Vala' in out:
              return ValaCompiler(exelist, version, for_machine, is_cross)
          raise EnvironmentException('Unknown compiler "' + ' '.join(exelist) + '"')
  
      def detect_rust_compiler(self, for_machine):
          popen_exceptions = {}
          compilers, ccache, exe_wrap = self._get_compilers('rust', for_machine)
          is_cross = not self.machines.matches_build_machine(for_machine)
          for compiler in compilers:
              if isinstance(compiler, str):
                  compiler = [compiler]
              arg = ['--version']
              try:
                  p, out = Popen_safe(compiler + arg)[0:2]
              except OSError as e:
                  popen_exceptions[' '.join(compiler + arg)] = e
                  continue
  
              version = search_version(out)
  
              if 'rustc' in out:
                  # Chalk up another quirk for rust. There is no way (AFAICT) to
                  # figure out what linker rustc is using for a non-nightly compiler
                  # (On nightly you can pass -Z print-link-args). So we're going to
                  # hard code the linker based on the platform.
                  # Currenty gnu ld is used for everything except apple by
                  # default, and apple ld is used on mac.
                  # TODO: find some better way to figure this out.
                  if self.machines[for_machine].is_darwin():
                      linker = AppleDynamicLinker([], for_machine, 'Apple ld', '-Wl,')
                  else:
                      linker = GnuDynamicLinker([], for_machine, 'GNU ld', '-Wl,')
                  return RustCompiler(compiler, version, for_machine, is_cross, exe_wrap, linker=linker)
  
          self._handle_exceptions(popen_exceptions, compilers)
  
      def detect_d_compiler(self, for_machine: MachineChoice):
          exelist = self.binaries[for_machine].lookup_entry('d')
          # Search for a D compiler.
          # We prefer LDC over GDC unless overridden with the DC
          # environment variable because LDC has a much more
          # up to date language version at time (2016).
          if exelist is not None:
              if os.path.basename(exelist[-1]).startswith(('ldmd', 'gdmd')):
                  raise EnvironmentException(
                      'Meson does not support {} as it is only a DMD frontend for another compiler.'
                      'Please provide a valid value for DC or unset it so that Meson can resolve the compiler by itself.'.format(exelist[-1]))
          else:
              for d in self.default_d:
                  if shutil.which(d):
                      exelist = [d]
                      break
              else:
                  raise EnvironmentException('Could not find any supported D compiler.')
  
          try:
              p, out = Popen_safe(exelist + ['--version'])[0:2]
          except OSError:
              raise EnvironmentException('Could not execute D compiler "%s"' % ' '.join(exelist))
          version = search_version(out)
          full_version = out.split('\n', 1)[0]
  
          # Detect the target architecture, required for proper architecture handling on Windows.
          c_compiler = {}
          is_msvc = mesonlib.is_windows() and 'VCINSTALLDIR' in os.environ
          if is_msvc:
              c_compiler = {'c': self.detect_c_compiler(for_machine)} # MSVC compiler is required for correct platform detection.
  
          arch = detect_cpu_family(c_compiler)
          if is_msvc and arch == 'x86':
              arch = 'x86_mscoff'
  
          if 'LLVM D compiler' in out:
              # LDC seems to require a file
              m = self.machines[for_machine]
              if m.is_windows() or m.is_cygwin():
                  # Getting LDC on windows to give useful linker output when not
                  # doing real work is painfully hard. It ships with a verison of
                  # lld-link, so just assume that we're going to use lld-link
                  # with it.
                  _, o, _ = Popen_safe(['lld-link.exe', '--version'])
                  linker = ClangClDynamicLinker(for_machine, version=search_version(o))
              else:
                  with tempfile.NamedTemporaryFile(suffix='.d') as f:
                      linker = self._guess_nix_linker(
                          exelist, for_machine,
                          compilers.LLVMDCompiler.LINKER_PREFIX,
                          extra_args=[f.name])
              return compilers.LLVMDCompiler(exelist, version, for_machine, arch, full_version=full_version, linker=linker)
          elif 'gdc' in out:
              linker = self._guess_nix_linker(exelist, for_machine, compilers.GnuDCompiler.LINKER_PREFIX)
              return compilers.GnuDCompiler(exelist, version, for_machine, arch, full_version=full_version, linker=linker)
          elif 'The D Language Foundation' in out or 'Digital Mars' in out:
              # DMD seems to require a file
              m = self.machines[for_machine]
              if m.is_windows() or m.is_cygwin():
                  linker = OptlinkDynamicLinker(for_machine, version=full_version)
              else:
                  with tempfile.NamedTemporaryFile(suffix='.d') as f:
                      linker = self._guess_nix_linker(
                          exelist, for_machine,
                          compilers.LLVMDCompiler.LINKER_PREFIX,
                          extra_args=[f.name])
              return compilers.DmdDCompiler(exelist, version, for_machine, arch, full_version=full_version, linker=linker)
          raise EnvironmentException('Unknown compiler "' + ' '.join(exelist) + '"')
  
      def detect_swift_compiler(self, for_machine):
          exelist = self.binaries.host.lookup_entry('swift')
          is_cross = not self.machines.matches_build_machine(for_machine)
          if exelist is None:
              # TODO support fallback
              exelist = [self.default_swift[0]]
  
          try:
              p, _, err = Popen_safe(exelist + ['-v'])
          except OSError:
              raise EnvironmentException('Could not execute Swift compiler "%s"' % ' '.join(exelist))
          version = search_version(err)
          if 'Swift' in err:
              # As for 5.0.1 swiftc *requires* a file to check the linker:
              with tempfile.NamedTemporaryFile(suffix='.swift') as f:
                  linker = self._guess_nix_linker(
                      exelist, for_machine, compilers.SwiftCompiler.LINKER_PREFIX, extra_args=[f.name])
              return compilers.SwiftCompiler(exelist, version, for_machine, is_cross, linker=linker)
  
          raise EnvironmentException('Unknown compiler "' + ' '.join(exelist) + '"')
  
      def compiler_from_language(self, lang: str, for_machine: MachineChoice):
          if lang == 'c':
              comp = self.detect_c_compiler(for_machine)
          elif lang == 'cpp':
              comp = self.detect_cpp_compiler(for_machine)
          elif lang == 'objc':
              comp = self.detect_objc_compiler(for_machine)
          elif lang == 'cuda':
              comp = self.detect_cuda_compiler(for_machine)
          elif lang == 'objcpp':
              comp = self.detect_objcpp_compiler(for_machine)
          elif lang == 'java':
              comp = self.detect_java_compiler(for_machine)
          elif lang == 'cs':
              comp = self.detect_cs_compiler(for_machine)
          elif lang == 'vala':
              comp = self.detect_vala_compiler(for_machine)
          elif lang == 'd':
              comp = self.detect_d_compiler(for_machine)
          elif lang == 'rust':
              comp = self.detect_rust_compiler(for_machine)
          elif lang == 'fortran':
              comp = self.detect_fortran_compiler(for_machine)
          elif lang == 'swift':
              comp = self.detect_swift_compiler(for_machine)
          else:
              comp = None
          return comp
  
      def detect_compiler_for(self, lang: str, for_machine: MachineChoice):
          comp = self.compiler_from_language(lang, for_machine)
          if comp is not None:
              assert comp.for_machine == for_machine
              self.coredata.process_new_compiler(lang, comp, self)
          return comp
  
      def detect_static_linker(self, compiler):
          linker = self.binaries[compiler.for_machine].lookup_entry('ar')
          if linker is not None:
              linkers = [linker]
          else:
              evar = 'AR'
              defaults = [[l] for l in self.default_static_linker]
              if isinstance(compiler, compilers.CudaCompiler):
                  linkers = [self.cuda_static_linker] + defaults
              elif evar in os.environ:
                  linkers = [split_args(os.environ[evar])]
              elif isinstance(compiler, compilers.VisualStudioLikeCompiler):
                  linkers = [self.vs_static_linker, self.clang_cl_static_linker]
              elif isinstance(compiler, compilers.GnuCompiler):
                  # Use gcc-ar if available; needed for LTO
                  linkers = [self.gcc_static_linker] + defaults
              elif isinstance(compiler, compilers.ClangCompiler):
                  # Use llvm-ar if available; needed for LTO
                  linkers = [self.clang_static_linker] + defaults
              elif isinstance(compiler, compilers.DCompiler):
                  # Prefer static linkers over linkers used by D compilers
                  if mesonlib.is_windows():
                      linkers = [self.vs_static_linker, self.clang_cl_static_linker, compiler.get_linker_exelist()]
                  else:
                      linkers = defaults
              elif isinstance(compiler, IntelClCCompiler):
                  # Intel has it's own linker that acts like microsoft's lib
                  linkers = ['xilib']
              elif isinstance(compiler, (PGICCompiler, PGIFortranCompiler)) and mesonlib.is_windows():
                  linkers = [self.default_static_linker]  # this is just a wrapper calling link/lib on Windows, keeping things simple.
              else:
                  linkers = defaults
          popen_exceptions = {}
          for linker in linkers:
              if not {'lib', 'lib.exe', 'llvm-lib', 'llvm-lib.exe', 'xilib', 'xilib.exe'}.isdisjoint(linker):
                  arg = '/?'
              else:
                  arg = '--version'
              try:
                  p, out, err = Popen_safe(linker + [arg])
              except OSError as e:
                  popen_exceptions[' '.join(linker + [arg])] = e
                  continue
              if "xilib: executing 'lib'" in err:
                  return IntelVisualStudioLinker(linker, getattr(compiler, 'machine', None))
              if '/OUT:' in out.upper() or '/OUT:' in err.upper():
                  return VisualStudioLinker(linker, getattr(compiler, 'machine', None))
              if 'ar-Error-Unknown switch: --version' in err:
                  return PGIStaticLinker(linker)
              if p.returncode == 0 and ('armar' in linker or 'armar.exe' in linker):
                  return ArmarLinker(linker)
              if 'DMD32 D Compiler' in out or 'DMD64 D Compiler' in out:
                  return DLinker(linker, compiler.arch)
              if 'LDC - the LLVM D compiler' in out:
                  return DLinker(linker, compiler.arch)
              if 'GDC' in out and ' based on D ' in out:
                  return DLinker(linker, compiler.arch)
              if err.startswith('Renesas') and ('rlink' in linker or 'rlink.exe' in linker):
                  return CcrxLinker(linker)
              if p.returncode == 0:
                  return ArLinker(linker)
              if p.returncode == 1 and err.startswith('usage'): # OSX
                  return ArLinker(linker)
              if p.returncode == 1 and err.startswith('Usage'): # AIX
                  return ArLinker(linker)
              if p.returncode == 1 and err.startswith('ar: bad option: --'): # Solaris
                  return ArLinker(linker)
          self._handle_exceptions(popen_exceptions, linkers, 'linker')
          raise EnvironmentException('Unknown static linker "%s"' % ' '.join(linkers))
  
      def get_source_dir(self):
          return self.source_dir
  
      def get_build_dir(self):
          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_builtin_option('prefix')
  
      def get_libdir(self) -> str:
          return self.coredata.get_builtin_option('libdir')
  
      def get_libexecdir(self) -> str:
          return self.coredata.get_builtin_option('libexecdir')
  
      def get_bindir(self) -> str:
          return self.coredata.get_builtin_option('bindir')
  
      def get_includedir(self) -> str:
          return self.coredata.get_builtin_option('includedir')
  
      def get_mandir(self) -> str:
          return self.coredata.get_builtin_option('mandir')
  
      def get_datadir(self) -> str:
          return self.coredata.get_builtin_option('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):
          if not self.need_exe_wrapper():
              from .dependencies import EmptyExternalProgram
              return EmptyExternalProgram()
          return self.exe_wrapper
  
files: mesonbuild/environment.py