text: # Copyright 2012-2017 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 copy, os, re
  from collections import OrderedDict
  import itertools, pathlib
  
  from . import environment
  from . import dependencies
  from . import mlog
  from .mesonlib import File, MesonException, listify, extract_as_list
  from .mesonlib import typeslistify, stringlistify, classify_unity_sources
  from .mesonlib import get_filenames_templates_dict, substitute_values
  from .mesonlib import for_windows, for_darwin, for_cygwin, for_android
  from .compilers import is_object, clike_langs, sort_clike, lang_suffixes
  
  known_basic_kwargs = {'install': True,
                        'c_pch': True,
                        'cpp_pch': True,
                        'c_args': True,
                        'objc_args': True,
                        'objcpp_args': True,
                        'cpp_args': True,
                        'cs_args': True,
                        'vala_args': True,
                        'fortran_args': True,
                        'd_args': True,
                        'd_import_dirs': True,
                        'd_unittest': True,
                        'd_module_versions': True,
                        'java_args': True,
                        'rust_args': True,
                        'link_args': True,
                        'link_depends': True,
                        'link_with': True,
                        'link_whole': True,
                        'implicit_include_directories': True,
                        'include_directories': True,
                        'dependencies': True,
                        'install_dir': True,
                        'main_class': True,
                        'name_suffix': True,
                        'gui_app': True,
                        'extra_files': True,
                        'install_rpath': True,
                        'build_rpath': True,
                        'resources': True,
                        'sources': True,
                        'objects': True,
                        'native': True,
                        'build_by_default': True,
                        'override_options': True,
                        }
  
  # These contain kwargs supported by both static and shared libraries. These are
  # combined here because a library() call might be shared_library() or
  # static_library() at runtime based on the configuration.
  # FIXME: Find a way to pass that info down here so we can have proper target
  # kwargs checking when specifically using shared_library() or static_library().
  known_lib_kwargs = known_basic_kwargs.copy()
  known_lib_kwargs.update({'version': True, # Only for shared libs
                           'soversion': True, # Only for shared libs
                           'name_prefix': True,
                           'vs_module_defs': True, # Only for shared libs
                           'vala_header': True,
                           'vala_vapi': True,
                           'vala_gir': True,
                           'pic': True, # Only for static libs
                           'rust_crate_type': True, # Only for Rust libs
                           })
  
  known_exe_kwargs = known_basic_kwargs.copy()
  known_exe_kwargs.update({'implib': True,
                           'export_dynamic': True
                           })
  
  class InvalidArguments(MesonException):
      pass
  
  class Build:
      """A class that holds the status of one build including
      all dependencies and so on.
      """
  
      def __init__(self, environment):
          self.project_name = 'name of master project'
          self.project_version = None
          self.environment = environment
          self.projects = {}
          self.targets = OrderedDict()
          self.compilers = OrderedDict()
          self.cross_compilers = OrderedDict()
          self.global_args = {}
          self.projects_args = {}
          self.global_link_args = {}
          self.projects_link_args = {}
          self.tests = []
          self.benchmarks = []
          self.headers = []
          self.man = []
          self.data = []
          self.static_linker = None
          self.static_cross_linker = None
          self.subprojects = {}
          self.install_scripts = []
          self.postconf_scripts = []
          self.install_dirs = []
          self.dep_manifest_name = None
          self.dep_manifest = {}
          self.cross_stdlibs = {}
          self.test_setups = {}
  
      def add_compiler(self, compiler):
          if self.static_linker is None and compiler.needs_static_linker():
              self.static_linker = self.environment.detect_static_linker(compiler)
          lang = compiler.get_language()
          if lang not in self.compilers:
              self.compilers[lang] = compiler
  
      def add_cross_compiler(self, compiler):
          if not self.cross_compilers:
              self.static_cross_linker = self.environment.detect_static_linker(compiler)
          lang = compiler.get_language()
          if lang not in self.cross_compilers:
              self.cross_compilers[lang] = compiler
  
      def get_project(self):
          return self.projects['']
  
      def get_targets(self):
          return self.targets
  
      def get_tests(self):
          return self.tests
  
      def get_benchmarks(self):
          return self.benchmarks
  
      def get_headers(self):
          return self.headers
  
      def get_man(self):
          return self.man
  
      def get_data(self):
          return self.data
  
      def get_install_subdirs(self):
          return self.install_dirs
  
      def get_global_args(self, compiler):
          return self.global_args.get(compiler.get_language(), [])
  
      def get_project_args(self, compiler, project):
          args = self.projects_args.get(project)
          if not args:
              return []
          return args.get(compiler.get_language(), [])
  
      def get_global_link_args(self, compiler):
          return self.global_link_args.get(compiler.get_language(), [])
  
      def get_project_link_args(self, compiler, project):
          link_args = self.projects_link_args.get(project)
          if not link_args:
              return []
  
          return link_args.get(compiler.get_language(), [])
  
  class IncludeDirs:
      def __init__(self, curdir, dirs, is_system, extra_build_dirs=None):
          self.curdir = curdir
          self.incdirs = dirs
          self.is_system = is_system
          # Interpreter has validated that all given directories
          # actually exist.
          if extra_build_dirs is None:
              self.extra_build_dirs = []
          else:
              self.extra_build_dirs = extra_build_dirs
  
      def __repr__(self):
          r = '<{} {}/{}>'
          return r.format(self.__class__.__name__, self.curdir, self.incdirs)
  
      def get_curdir(self):
          return self.curdir
  
      def get_incdirs(self):
          return self.incdirs
  
      def get_extra_build_dirs(self):
          return self.extra_build_dirs
  
  class ExtractedObjects:
      '''
      Holds a list of sources for which the objects must be extracted
      '''
      def __init__(self, target, srclist, is_unity):
          self.target = target
          self.srclist = srclist
          if is_unity:
              self.check_unity_compatible()
  
      def __repr__(self):
          r = '<{0} {1!r}: {2}>'
          return r.format(self.__class__.__name__, self.target.name, self.srclist)
  
      def check_unity_compatible(self):
          # Figure out if the extracted object list is compatible with a Unity
          # build. When we're doing a Unified build, we go through the sources,
          # and create a single source file from each subset of the sources that
          # can be compiled with a specific compiler. Then we create one object
          # from each unified source file.
          # If the list of sources for which we want objects is the same as the
          # list of sources that go into each unified build, we're good.
          srclist_set = set(self.srclist)
          # Objects for all the sources are required, so we're compatible
          if srclist_set == set(self.target.sources):
              return
          # Check if the srclist is a subset (of the target's sources) that is
          # going to form a unified source file and a single object
          compsrcs = classify_unity_sources(self.target.compilers.values(),
                                            self.target.sources)
          for srcs in compsrcs.values():
              if srclist_set == set(srcs):
                  return
          msg = 'Single object files can not be extracted in Unity builds. ' \
                'You can only extract all the object files at once.'
          raise MesonException(msg)
  
  
  class EnvironmentVariables:
      def __init__(self):
          self.envvars = []
  
      def __repr__(self):
          repr_str = "<{0}: {1}>"
          return repr_str.format(self.__class__.__name__, self.envvars)
  
      def get_value(self, values, kwargs):
          separator = kwargs.get('separator', os.pathsep)
  
          value = ''
          for var in values:
              value += separator + var
          return separator, value.strip(separator)
  
      def set(self, env, name, values, kwargs):
          return self.get_value(values, kwargs)[1]
  
      def append(self, env, name, values, kwargs):
          sep, value = self.get_value(values, kwargs)
          if name in env:
              return env[name] + sep + value
          return value
  
      def prepend(self, env, name, values, kwargs):
          sep, value = self.get_value(values, kwargs)
          if name in env:
              return value + sep + env[name]
  
          return value
  
      def get_env(self, full_env):
          env = {}
          for method, name, values, kwargs in self.envvars:
              env[name] = method(full_env, name, values, kwargs)
          return env
  
  class Target:
      def __init__(self, name, subdir, subproject, build_by_default):
          if '/' in name or '\\' in name:
              # Fix failing test 53 when this becomes an error.
              mlog.warning('''Target "%s" has a path separator in its name.
  This is not supported, it can cause unexpected failures and will become
  a hard error in the future.''' % name)
          self.name = name
          self.subdir = subdir
          self.subproject = subproject
          self.build_by_default = build_by_default
          self.install = False
          self.build_always = False
          self.option_overrides = {}
  
      def get_basename(self):
          return self.name
  
      def get_subdir(self):
          return self.subdir
  
      def get_id(self):
          # This ID must also be a valid file name on all OSs.
          # It should also avoid shell metacharacters for obvious
          # reasons.
          base = self.name + self.type_suffix()
          if self.subproject == '':
              return base
          return self.subproject + '@@' + base
  
      def process_kwargs(self, kwargs):
          if 'build_by_default' in kwargs:
              self.build_by_default = kwargs['build_by_default']
              if not isinstance(self.build_by_default, bool):
                  raise InvalidArguments('build_by_default must be a boolean value.')
          self.option_overrides = self.parse_overrides(kwargs)
  
      def parse_overrides(self, kwargs):
          result = {}
          overrides = stringlistify(kwargs.get('override_options', []))
          for o in overrides:
              if '=' not in o:
                  raise InvalidArguments('Overrides must be of form "key=value"')
              k, v = o.split('=', 1)
              k = k.strip()
              v = v.strip()
              result[k] = v
          return result
  
  
  class BuildTarget(Target):
      def __init__(self, name, subdir, subproject, is_cross, sources, objects, environment, kwargs):
          super().__init__(name, subdir, subproject, True)
          self.is_cross = is_cross
          unity_opt = environment.coredata.get_builtin_option('unity')
          self.is_unity = unity_opt == 'on' or (unity_opt == 'subprojects' and subproject != '')
          self.environment = environment
          self.sources = []
          self.compilers = OrderedDict()
          self.objects = []
          self.external_deps = []
          self.include_dirs = []
          self.link_targets = []
          self.link_whole_targets = []
          self.link_depends = []
          self.name_prefix_set = False
          self.name_suffix_set = False
          self.filename = 'no_name'
          # The list of all files outputted by this target. Useful in cases such
          # as Vala which generates .vapi and .h besides the compiled output.
          self.outputs = [self.filename]
          self.need_install = False
          self.pch = {}
          self.extra_args = {}
          self.generated = []
          self.extra_files = []
          # Sources can be:
          # 1. Pre-existing source files in the source tree
          # 2. Pre-existing sources generated by configure_file in the build tree
          # 3. Sources files generated by another target or a Generator
          self.process_sourcelist(sources)
          # Objects can be:
          # 1. Pre-existing objects provided by the user with the `objects:` kwarg
          # 2. Compiled objects created by and extracted from another target
          self.process_objectlist(objects)
          self.process_compilers()
          self.process_kwargs(kwargs, environment)
          self.check_unknown_kwargs(kwargs)
          if not any([self.sources, self.generated, self.objects, self.link_whole]):
              raise InvalidArguments('Build target %s has no sources.' % name)
          self.process_compilers_late()
          self.validate_sources()
          self.validate_cross_install(environment)
  
      def __lt__(self, other):
          return self.get_id() < other.get_id()
  
      def __repr__(self):
          repr_str = "<{0} {1}: {2}>"
          return repr_str.format(self.__class__.__name__, self.get_id(), self.filename)
  
      def validate_cross_install(self, environment):
          if environment.is_cross_build() and not self.is_cross and self.install:
              raise InvalidArguments('Tried to install a natively built target in a cross build.')
  
      def check_unknown_kwargs(self, kwargs):
          # Override this method in derived classes that have more
          # keywords.
          self.check_unknown_kwargs_int(kwargs, known_basic_kwargs)
  
      def check_unknown_kwargs_int(self, kwargs, known_kwargs):
          unknowns = []
          for k in kwargs:
              if k not in known_kwargs:
                  unknowns.append(k)
          if len(unknowns) > 0:
              mlog.warning('Unknown keyword argument(s) in target %s: %s.' %
                           (self.name, ', '.join(unknowns)))
  
      def process_objectlist(self, objects):
          assert(isinstance(objects, list))
          for s in objects:
              if hasattr(s, 'held_object'):
                  s = s.held_object
              if isinstance(s, (str, File, ExtractedObjects)):
                  self.objects.append(s)
              elif isinstance(s, (GeneratedList, CustomTarget)):
                  msg = 'Generated files are not allowed in the \'objects\' kwarg ' + \
                      'for target {!r}.\nIt is meant only for '.format(self.name) + \
                      'pre-built object files that are shipped with the\nsource ' + \
                      'tree. Try adding it in the list of sources.'
                  raise InvalidArguments(msg)
              else:
                  msg = 'Bad object of type {!r} in target {!r}.'.format(type(s).__name__, self.name)
                  raise InvalidArguments(msg)
  
      def process_sourcelist(self, sources):
          sources = listify(sources)
          added_sources = {} # If the same source is defined multiple times, use it only once.
          for s in sources:
              # Holder unpacking. Ugly.
              if hasattr(s, 'held_object'):
                  s = s.held_object
              if isinstance(s, File):
                  if s not in added_sources:
                      self.sources.append(s)
                      added_sources[s] = True
              elif isinstance(s, (GeneratedList, CustomTarget, CustomTargetIndex)):
                  self.generated.append(s)
              else:
                  msg = 'Bad source of type {!r} in target {!r}.'.format(type(s).__name__, self.name)
                  raise InvalidArguments(msg)
  
      @staticmethod
      def can_compile_remove_sources(compiler, sources):
          removed = False
          for s in sources[:]:
              if compiler.can_compile(s):
                  sources.remove(s)
                  removed = True
          return removed
  
      def process_compilers_late(self):
          """Processes additional compilers after kwargs have been evaluated.
  
          This can add extra compilers that might be required by keyword
          arguments, such as link_with or dependencies. It will also try to guess
          which compiler to use if one hasn't been selected already.
          """
          # Populate list of compilers
          if self.is_cross:
              compilers = self.environment.coredata.cross_compilers
          else:
              compilers = self.environment.coredata.compilers
  
          # If this library is linked against another library we need to consider
          # the languages of those libraries as well.
          if self.link_targets or self.link_whole_targets:
              extra = set()
              for t in itertools.chain(self.link_targets, self.link_whole_targets):
                  for name, compiler in t.compilers.items():
                      if name in clike_langs:
                          extra.add((name, compiler))
              for name, compiler in sorted(extra, key=lambda p: sort_clike(p[0])):
                  self.compilers[name] = compiler
  
          if not self.compilers:
              # No source files or parent targets, target consists of only object
              # files of unknown origin. Just add the first clike compiler
              # that we have and hope that it can link these objects
              for lang in clike_langs:
                  if lang in compilers:
                      self.compilers[lang] = compilers[lang]
                      break
  
      def process_compilers(self):
          '''
          Populate self.compilers, which is the list of compilers that this
          target will use for compiling all its sources.
          We also add compilers that were used by extracted objects to simplify
          dynamic linker determination.
          '''
          if not self.sources and not self.generated and not self.objects:
              return
          # Populate list of compilers
          if self.is_cross:
              compilers = self.environment.coredata.cross_compilers
          else:
              compilers = self.environment.coredata.compilers
          # Pre-existing sources
          sources = list(self.sources)
          # All generated sources
          for gensrc in self.generated:
              for s in gensrc.get_outputs():
                  # Generated objects can't be compiled, so don't use them for
                  # compiler detection. If our target only has generated objects,
                  # we will fall back to using the first c-like compiler we find,
                  # which is what we need.
                  if not is_object(s):
                      sources.append(s)
          # Sources that were used to create our extracted objects
          for o in self.objects:
              if not isinstance(o, ExtractedObjects):
                  continue
              for s in o.srclist:
                  # Don't add Vala sources since that will pull in the Vala
                  # compiler even though we will never use it since we are
                  # dealing with compiled C code.
                  if not s.endswith(lang_suffixes['vala']):
                      sources.append(s)
          if sources:
              # For each source, try to add one compiler that can compile it.
              # It's ok if no compilers can do so, because users are expected to
              # be able to add arbitrary non-source files to the sources list.
              for s in sources:
                  for lang, compiler in compilers.items():
                      if compiler.can_compile(s):
                          if lang not in self.compilers:
                              self.compilers[lang] = compiler
                          break
              # Re-sort according to clike_langs
              self.compilers = OrderedDict(sorted(self.compilers.items(),
                                                  key=lambda t: sort_clike(t[0])))
  
          # If all our sources are Vala, our target also needs the C compiler but
          # it won't get added above.
          if 'vala' in self.compilers and 'c' not in self.compilers:
              self.compilers['c'] = compilers['c']
  
      def validate_sources(self):
          if not self.sources:
              return
          for lang in ('cs', 'java'):
              if lang in self.compilers:
                  check_sources = list(self.sources)
                  compiler = self.compilers[lang]
                  if not self.can_compile_remove_sources(compiler, check_sources):
                      m = 'No {} sources found in target {!r}'.format(lang, self.name)
                      raise InvalidArguments(m)
                  if check_sources:
                      m = '{0} targets can only contain {0} files:\n'.format(lang.capitalize())
                      m += '\n'.join([repr(c) for c in check_sources])
                      raise InvalidArguments(m)
                  # CSharp and Java targets can't contain any other file types
                  assert(len(self.compilers) == 1)
                  return
  
      def process_link_depends(self, sources, environment):
          """Process the link_depends keyword argument.
  
          This is designed to handle strings, Files, and the output of Custom
          Targets. Notably it doesn't handle generator() returned objects, since
          adding them as a link depends would inherently cause them to be
          generated twice, since the output needs to be passed to the ld_args and
          link_depends.
          """
          sources = listify(sources)
          for s in sources:
              if hasattr(s, 'held_object'):
                  s = s.held_object
  
              if isinstance(s, File):
                  self.link_depends.append(s)
              elif isinstance(s, str):
                  self.link_depends.append(
                      File.from_source_file(environment.source_dir, self.subdir, s))
              elif hasattr(s, 'get_outputs'):
                  self.link_depends.extend(
                      [File.from_built_file(s.subdir, p) for p in s.get_outputs()])
              else:
                  raise InvalidArguments(
                      'Link_depends arguments must be strings, Files, '
                      'or a Custom Target, or lists thereof.')
  
      def get_original_kwargs(self):
          return self.kwargs
  
      def unpack_holder(self, d):
          d = listify(d)
          newd = []
          for i in d:
              if isinstance(i, list):
                  i = self.unpack_holder(i)
              elif hasattr(i, 'held_object'):
                  i = i.held_object
              for t in ['dependencies', 'link_with', 'include_directories', 'sources']:
                  if hasattr(i, t):
                      setattr(i, t, self.unpack_holder(getattr(i, t)))
              newd.append(i)
          return newd
  
      def copy_kwargs(self, kwargs):
          self.kwargs = copy.copy(kwargs)
          # This sucks quite badly. Arguments
          # are holders but they can't be pickled
          # so unpack those known.
          for k, v in self.kwargs.items():
              if isinstance(v, list):
                  self.kwargs[k] = self.unpack_holder(v)
              if hasattr(v, 'held_object'):
                  self.kwargs[k] = v.held_object
          for t in ['dependencies', 'link_with', 'include_directories', 'sources']:
              if t in self.kwargs:
                  self.kwargs[t] = self.unpack_holder(self.kwargs[t])
  
      def extract_objects(self, srclist):
          obj_src = []
          for src in srclist:
              if not isinstance(src, str):
                  raise MesonException('Object extraction arguments must be strings.')
              src = File(False, self.subdir, src)
              if src not in self.sources:
                  raise MesonException('Tried to extract unknown source %s.' % src)
              obj_src.append(src)
          return ExtractedObjects(self, obj_src, self.is_unity)
  
      def extract_all_objects(self):
          return ExtractedObjects(self, self.sources, self.is_unity)
  
      def get_all_link_deps(self):
          return self.get_transitive_link_deps()
  
      def get_transitive_link_deps(self):
          result = []
          for i in self.link_targets:
              result += i.get_all_link_deps()
          return result
  
      def get_custom_install_dir(self):
          return self.install_dir
  
      def process_kwargs(self, kwargs, environment):
          super().process_kwargs(kwargs)
          self.copy_kwargs(kwargs)
          kwargs.get('modules', [])
          self.need_install = kwargs.get('install', self.need_install)
          llist = extract_as_list(kwargs, 'link_with')
          for linktarget in llist:
              # Sorry for this hack. Keyword targets are kept in holders
              # in kwargs. Unpack here without looking at the exact type.
              if hasattr(linktarget, "held_object"):
                  linktarget = linktarget.held_object
              if isinstance(linktarget, dependencies.ExternalLibrary):
                  raise MesonException('''An external library was used in link_with keyword argument, which
  is reserved for libraries built as part of this project. External
  libraries must be passed using the dependencies keyword argument
  instead, because they are conceptually "external dependencies",
  just like those detected with the dependency() function.''')
              self.link(linktarget)
          lwhole = extract_as_list(kwargs, 'link_whole')
          for linktarget in lwhole:
              # Sorry for this hack. Keyword targets are kept in holders
              # in kwargs. Unpack here without looking at the exact type.
              if hasattr(linktarget, "held_object"):
                  linktarget = linktarget.held_object
              self.link_whole(linktarget)
  
          c_pchlist, cpp_pchlist, clist, cpplist, cslist, valalist,  objclist, objcpplist, fortranlist, rustlist \
              = extract_as_list(kwargs, 'c_pch', 'cpp_pch', 'c_args', 'cpp_args', 'cs_args', 'vala_args', 'objc_args',
                                'objcpp_args', 'fortran_args', 'rust_args')
  
          self.add_pch('c', c_pchlist)
          self.add_pch('cpp', cpp_pchlist)
          compiler_args = {'c': clist, 'cpp': cpplist, 'cs': cslist, 'vala': valalist, 'objc': objclist, 'objcpp': objcpplist,
                           'fortran': fortranlist, 'rust': rustlist
                           }
          for key, value in compiler_args.items():
              self.add_compiler_args(key, value)
  
          if not isinstance(self, Executable):
              self.vala_header = kwargs.get('vala_header', self.name + '.h')
              self.vala_vapi = kwargs.get('vala_vapi', self.name + '.vapi')
              self.vala_gir = kwargs.get('vala_gir', None)
  
          dlist = stringlistify(kwargs.get('d_args', []))
          self.add_compiler_args('d', dlist)
          dfeatures = dict()
          dfeature_unittest = kwargs.get('d_unittest', False)
          if dfeature_unittest:
              dfeatures['unittest'] = dfeature_unittest
          dfeature_versions = kwargs.get('d_module_versions', None)
          if dfeature_versions:
              dfeatures['versions'] = dfeature_versions
          dfeature_import_dirs = kwargs.get('d_import_dirs', None)
          if dfeature_import_dirs:
              dfeatures['import_dirs'] = dfeature_import_dirs
          if dfeatures:
              if 'd' in self.compilers:
                  self.add_compiler_args('d', self.compilers['d'].get_feature_args(dfeatures))
  
          self.link_args = extract_as_list(kwargs, 'link_args')
          for i in self.link_args:
              if not isinstance(i, str):
                  raise InvalidArguments('Link_args arguments must be strings.')
          for l in self.link_args:
              if '-Wl,-rpath' in l or l.startswith('-rpath'):
                  mlog.warning('''Please do not define rpath with a linker argument, use install_rpath or build_rpath properties instead.
  This will become a hard error in a future Meson release.''')
          self.process_link_depends(kwargs.get('link_depends', []), environment)
          # Target-specific include dirs must be added BEFORE include dirs from
          # internal deps (added inside self.add_deps()) to override them.
          inclist = extract_as_list(kwargs, 'include_directories')
          self.add_include_dirs(inclist)
          # Add dependencies (which also have include_directories)
          deplist = extract_as_list(kwargs, 'dependencies')
          self.add_deps(deplist)
          # If an item in this list is False, the output corresponding to
          # the list index of that item will not be installed
          self.install_dir = typeslistify(kwargs.get('install_dir', [None]),
                                          (str, bool))
          main_class = kwargs.get('main_class', '')
          if not isinstance(main_class, str):
              raise InvalidArguments('Main class must be a string')
          self.main_class = main_class
          if isinstance(self, Executable):
              self.gui_app = kwargs.get('gui_app', False)
              if not isinstance(self.gui_app, bool):
                  raise InvalidArguments('Argument gui_app must be boolean.')
          elif 'gui_app' in kwargs:
              raise InvalidArguments('Argument gui_app can only be used on executables.')
          extra_files = extract_as_list(kwargs, 'extra_files')
          for i in extra_files:
              assert(isinstance(i, File))
              trial = os.path.join(environment.get_source_dir(), i.subdir, i.fname)
              if not(os.path.isfile(trial)):
                  raise InvalidArguments('Tried to add non-existing extra file %s.' % i)
          self.extra_files = extra_files
          self.install_rpath = kwargs.get('install_rpath', '')
          if not isinstance(self.install_rpath, str):
              raise InvalidArguments('Install_rpath is not a string.')
          self.build_rpath = kwargs.get('build_rpath', '')
          if not isinstance(self.build_rpath, str):
              raise InvalidArguments('Build_rpath is not a string.')
          resources = extract_as_list(kwargs, 'resources')
          for r in resources:
              if not isinstance(r, str):
                  raise InvalidArguments('Resource argument is not a string.')
              trial = os.path.join(environment.get_source_dir(), self.subdir, r)
              if not os.path.isfile(trial):
                  raise InvalidArguments('Tried to add non-existing resource %s.' % r)
          self.resources = resources
          if 'name_prefix' in kwargs:
              name_prefix = kwargs['name_prefix']
              if isinstance(name_prefix, list):
                  if name_prefix:
                      raise InvalidArguments('name_prefix array must be empty to signify null.')
              elif not isinstance(name_prefix, str):
                  raise InvalidArguments('name_prefix must be a string.')
              self.prefix = name_prefix
              self.name_prefix_set = True
          if 'name_suffix' in kwargs:
              name_suffix = kwargs['name_suffix']
              if isinstance(name_suffix, list):
                  if name_suffix:
                      raise InvalidArguments('name_suffix array must be empty to signify null.')
              else:
                  if not isinstance(name_suffix, str):
                      raise InvalidArguments('name_suffix must be a string.')
                  self.suffix = name_suffix
                  self.name_suffix_set = True
          if isinstance(self, StaticLibrary):
              # You can't disable PIC on OS X. The compiler ignores -fno-PIC.
              # PIC is always on for Windows (all code is position-independent
              # since library loading is done differently)
              if for_darwin(self.is_cross, self.environment) or for_windows(self.is_cross, self.environment):
                  self.pic = True
              elif '-fPIC' in clist + cpplist:
                  mlog.warning("Use the 'pic' kwarg instead of passing -fPIC manually to static library {!r}".format(self.name))
                  self.pic = True
              else:
                  self.pic = kwargs.get('pic', False)
                  if not isinstance(self.pic, bool):
                      raise InvalidArguments('Argument pic to static library {!r} must be boolean'.format(self.name))
          self.implicit_include_directories = kwargs.get('implicit_include_directories', True)
          if not isinstance(self.implicit_include_directories, bool):
              raise InvalidArguments('Implicit_include_directories must be a boolean.')
  
      def get_filename(self):
          return self.filename
  
      def get_outputs(self):
          return self.outputs
  
      def get_extra_args(self, language):
          return self.extra_args.get(language, [])
  
      def get_dependencies(self):
          transitive_deps = []
          for t in self.link_targets + self.link_whole_targets:
              transitive_deps.append(t)
              if isinstance(t, StaticLibrary):
                  transitive_deps += t.get_dependencies()
          return transitive_deps
  
      def get_source_subdir(self):
          return self.subdir
  
      def get_sources(self):
          return self.sources
  
      def get_objects(self):
          return self.objects
  
      def get_generated_sources(self):
          return self.generated
  
      def should_install(self):
          return self.need_install
  
      def has_pch(self):
          return len(self.pch) > 0
  
      def get_pch(self, language):
          try:
              return self.pch[language]
          except KeyError:
              return[]
  
      def get_include_dirs(self):
          return self.include_dirs
  
      def add_deps(self, deps):
          deps = listify(deps)
          for dep in deps:
              if hasattr(dep, 'held_object'):
                  dep = dep.held_object
              if isinstance(dep, dependencies.InternalDependency):
                  # Those parts that are internal.
                  self.process_sourcelist(dep.sources)
                  self.add_include_dirs(dep.include_directories)
                  for l in dep.libraries:
                      self.link(l)
                  # Those parts that are external.
                  extpart = dependencies.InternalDependency('undefined',
                                                            [],
                                                            dep.compile_args,
                                                            dep.link_args,
                                                            [], [], [])
                  self.external_deps.append(extpart)
                  # Deps of deps.
                  self.add_deps(dep.ext_deps)
              elif isinstance(dep, dependencies.Dependency):
                  self.external_deps.append(dep)
                  self.process_sourcelist(dep.get_sources())
              elif isinstance(dep, BuildTarget):
                  raise InvalidArguments('''Tried to use a build target as a dependency.
  You probably should put it in link_with instead.''')
              else:
                  # This is a bit of a hack. We do not want Build to know anything
                  # about the interpreter so we can't import it and use isinstance.
                  # This should be reliable enough.
                  if hasattr(dep, 'project_args_frozen') or hasattr(dep, 'global_args_frozen'):
                      raise InvalidArguments('Tried to use subproject object as a dependency.\n'
                                             'You probably wanted to use a dependency declared in it instead.\n'
                                             'Access it by calling get_variable() on the subproject object.')
                  raise InvalidArguments('Argument is of an unacceptable type {!r}.\nMust be '
                                         'either an external dependency (returned by find_library() or '
                                         'dependency()) or an internal dependency (returned by '
                                         'declare_dependency()).'.format(type(dep).__name__))
  
      def get_external_deps(self):
          return self.external_deps
  
      def link(self, target):
          for t in listify(target, unholder=True):
              if not isinstance(t, Target):
                  raise InvalidArguments('{!r} is not a target.'.format(t))
              if not t.is_linkable_target():
                  raise InvalidArguments('Link target {!r} is not linkable.'.format(t))
              if isinstance(self, SharedLibrary) and isinstance(t, StaticLibrary) and not t.pic:
                  msg = "Can't link non-PIC static library {!r} into shared library {!r}. ".format(t.name, self.name)
                  msg += "Use the 'pic' option to static_library to build with PIC."
                  raise InvalidArguments(msg)
              if self.is_cross != t.is_cross:
                  raise InvalidArguments('Tried to mix cross built and native libraries in target {!r}'.format(self.name))
              self.link_targets.append(t)
  
      def link_whole(self, target):
          for t in listify(target, unholder=True):
              if not isinstance(t, StaticLibrary):
                  raise InvalidArguments('{!r} is not a static library.'.format(t))
              if isinstance(self, SharedLibrary) and not t.pic:
                  msg = "Can't link non-PIC static library {!r} into shared library {!r}. ".format(t.name, self.name)
                  msg += "Use the 'pic' option to static_library to build with PIC."
                  raise InvalidArguments(msg)
              if self.is_cross != t.is_cross:
                  raise InvalidArguments('Tried to mix cross built and native libraries in target {!r}'.format(self.name))
              self.link_whole_targets.append(t)
  
      def add_pch(self, language, pchlist):
          if not pchlist:
              return
          elif len(pchlist) == 1:
              if not environment.is_header(pchlist[0]):
                  raise InvalidArguments('PCH argument %s is not a header.' % pchlist[0])
          elif len(pchlist) == 2:
              if environment.is_header(pchlist[0]):
                  if not environment.is_source(pchlist[1]):
                      raise InvalidArguments('PCH definition must contain one header and at most one source.')
              elif environment.is_source(pchlist[0]):
                  if not environment.is_header(pchlist[1]):
                      raise InvalidArguments('PCH definition must contain one header and at most one source.')
                  pchlist = [pchlist[1], pchlist[0]]
              else:
                  raise InvalidArguments('PCH argument %s is of unknown type.' % pchlist[0])
          elif len(pchlist) > 2:
              raise InvalidArguments('PCH definition may have a maximum of 2 files.')
          self.pch[language] = pchlist
  
      def add_include_dirs(self, args):
          ids = []
          for a in args:
              # FIXME same hack, forcibly unpack from holder.
              if hasattr(a, 'held_object'):
                  a = a.held_object
              if not isinstance(a, IncludeDirs):
                  raise InvalidArguments('Include directory to be added is not an include directory object.')
              ids.append(a)
          self.include_dirs += ids
  
      def add_compiler_args(self, language, args):
          args = listify(args)
          for a in args:
              if not isinstance(a, (str, File)):
                  raise InvalidArguments('A non-string passed to compiler args.')
          if language in self.extra_args:
              self.extra_args[language] += args
          else:
              self.extra_args[language] = args
  
      def get_aliases(self):
          return {}
  
      def get_langs_used_by_deps(self):
          '''
          Sometimes you want to link to a C++ library that exports C API, which
          means the linker must link in the C++ stdlib, and we must use a C++
          compiler for linking. The same is also applicable for objc/objc++, etc,
          so we can keep using clike_langs for the priority order.
  
          See: https://github.com/mesonbuild/meson/issues/1653
          '''
          langs = []
          # Check if any of the external libraries were written in this language
          for dep in self.external_deps:
              if dep.language not in langs:
                  langs.append(dep.language)
          # Check if any of the internal libraries this target links to were
          # written in this language
          for link_target in itertools.chain(self.link_targets, self.link_whole_targets):
              for language in link_target.compilers:
                  if language not in langs:
                      langs.append(language)
          return langs
  
      def get_clike_dynamic_linker(self):
          '''
          We use the order of languages in `clike_langs` to determine which
          linker to use in case the target has sources compiled with multiple
          compilers. All languages other than those in this list have their own
          linker.
          Note that Vala outputs C code, so Vala sources can use any linker
          that can link compiled C. We don't actually need to add an exception
          for Vala here because of that.
          '''
          # Populate list of all compilers, not just those being used to compile
          # sources in this target
          if self.is_cross:
              all_compilers = self.environment.coredata.cross_compilers
          else:
              all_compilers = self.environment.coredata.compilers
          # Languages used by dependencies
          dep_langs = self.get_langs_used_by_deps()
          # Pick a compiler based on the language priority-order
          for l in clike_langs:
              if l in self.compilers or l in dep_langs:
                  try:
                      return all_compilers[l]
                  except KeyError:
                      raise MesonException(
                          'Could not get a dynamic linker for build target {!r}. '
                          'Requires a linker for language "{}", but that is not '
                          'a project language.'.format(self.name, l))
  
          m = 'Could not get a dynamic linker for build target {!r}'
          raise AssertionError(m.format(self.name))
  
      def get_using_msvc(self):
          '''
          Check if the dynamic linker is MSVC. Used by Executable, StaticLibrary,
          and SharedLibrary for deciding when to use MSVC-specific file naming
          and debug filenames.
  
          If at least some code is built with MSVC and the final library is
          linked with MSVC, we can be sure that some debug info will be
          generated. We only check the dynamic linker here because the static
          linker is guaranteed to be of the same type.
  
          Interesting cases:
          1. The Vala compiler outputs C code to be compiled by whatever
             C compiler we're using, so all objects will still be created by the
             MSVC compiler.
          2. If the target contains only objects, process_compilers guesses and
             picks the first compiler that smells right.
          '''
          linker = self.get_clike_dynamic_linker()
          if linker and linker.get_id() == 'msvc':
              return True
          return False
  
      def is_linkable_target(self):
          return False
  
  
  class Generator:
      def __init__(self, args, kwargs):
          if len(args) != 1:
              raise InvalidArguments('Generator requires exactly one positional argument: the executable')
          exe = args[0]
          if hasattr(exe, 'held_object'):
              exe = exe.held_object
          if not isinstance(exe, (Executable, dependencies.ExternalProgram)):
              raise InvalidArguments('First generator argument must be an executable.')
          self.exe = exe
          self.depfile = None
          self.capture = False
          self.process_kwargs(kwargs)
  
      def __repr__(self):
          repr_str = "<{0}: {1}>"
          return repr_str.format(self.__class__.__name__, self.exe)
  
      def get_exe(self):
          return self.exe
  
      def process_kwargs(self, kwargs):
          if 'arguments' not in kwargs:
              raise InvalidArguments('Generator must have "arguments" keyword argument.')
          args = kwargs['arguments']
          if isinstance(args, str):
              args = [args]
          if not isinstance(args, list):
              raise InvalidArguments('"Arguments" keyword argument must be a string or a list of strings.')
          for a in args:
              if not isinstance(a, str):
                  raise InvalidArguments('A non-string object in "arguments" keyword argument.')
          self.arglist = args
          if 'output' not in kwargs:
              raise InvalidArguments('Generator must have "output" keyword argument.')
          outputs = listify(kwargs['output'])
          for rule in outputs:
              if not isinstance(rule, str):
                  raise InvalidArguments('"output" may only contain strings.')
              if '@BASENAME@' not in rule and '@PLAINNAME@' not in rule:
                  raise InvalidArguments('Every element of "output" must contain @BASENAME@ or @PLAINNAME@.')
              if '/' in rule or '\\' in rule:
                  raise InvalidArguments('"outputs" must not contain a directory separator.')
          if len(outputs) > 1:
              for o in outputs:
                  if '@OUTPUT@' in o:
                      raise InvalidArguments('Tried to use @OUTPUT@ in a rule with more than one output.')
          self.outputs = outputs
          if 'depfile' in kwargs:
              depfile = kwargs['depfile']
              if not isinstance(depfile, str):
                  raise InvalidArguments('Depfile must be a string.')
              if os.path.basename(depfile) != depfile:
                  raise InvalidArguments('Depfile must be a plain filename without a subdirectory.')
              self.depfile = depfile
          if 'capture' in kwargs:
              capture = kwargs['capture']
              if not isinstance(capture, bool):
                  raise InvalidArguments('Capture must be boolean.')
              self.capture = capture
  
      def get_base_outnames(self, inname):
          plainname = os.path.basename(inname)
          basename = os.path.splitext(plainname)[0]
          bases = [x.replace('@BASENAME@', basename).replace('@PLAINNAME@', plainname) for x in self.outputs]
          return bases
  
      def get_dep_outname(self, inname):
          if self.depfile is None:
              raise InvalidArguments('Tried to get dep name for rule that does not have dependency file defined.')
          plainname = os.path.basename(inname)
          basename = os.path.splitext(plainname)[0]
          return self.depfile.replace('@BASENAME@', basename).replace('@PLAINNAME@', plainname)
  
      def get_arglist(self, inname):
          plainname = os.path.basename(inname)
          basename = os.path.splitext(plainname)[0]
          return [x.replace('@BASENAME@', basename).replace('@PLAINNAME@', plainname) for x in self.arglist]
  
      def is_parent_path(self, parent, trial):
          relpath = pathlib.PurePath(trial).relative_to(parent)
          return relpath.parts[0] != '..' # For subdirs we can only go "down".
  
      def process_files(self, name, files, state, preserve_path_from=None, extra_args=[]):
          output = GeneratedList(self, state.subdir, preserve_path_from, extra_args=extra_args)
          for f in files:
              if isinstance(f, str):
                  f = File.from_source_file(state.environment.source_dir, state.subdir, f)
              elif not isinstance(f, File):
                  raise InvalidArguments('{} arguments must be strings or files not {!r}.'.format(name, f))
              if preserve_path_from:
                  abs_f = f.absolute_path(state.environment.source_dir, state.environment.build_dir)
                  if not self.is_parent_path(preserve_path_from, abs_f):
                      raise InvalidArguments('When using preserve_path_from, all input files must be in a subdirectory of the given dir.')
              output.add_file(f, state)
          return output
  
  
  class GeneratedList:
      def __init__(self, generator, subdir, preserve_path_from=None, extra_args=[]):
          if hasattr(generator, 'held_object'):
              generator = generator.held_object
          self.generator = generator
          self.name = self.generator.exe
          self.subdir = subdir
          self.infilelist = []
          self.outfilelist = []
          self.outmap = {}
          self.extra_depends = []
          self.preserve_path_from = preserve_path_from
          self.extra_args = extra_args
  
      def add_preserved_path_segment(self, infile, outfiles, state):
          result = []
          in_abs = infile.absolute_path(state.environment.source_dir, state.environment.build_dir)
          assert(os.path.isabs(self.preserve_path_from))
          rel = os.path.relpath(in_abs, self.preserve_path_from)
          path_segment = os.path.dirname(rel)
          for of in outfiles:
              result.append(os.path.join(path_segment, of))
          return result
  
      def add_file(self, newfile, state):
          self.infilelist.append(newfile)
          outfiles = self.generator.get_base_outnames(newfile.fname)
          if self.preserve_path_from:
              outfiles = self.add_preserved_path_segment(newfile, outfiles, state)
          self.outfilelist += outfiles
          self.outmap[newfile] = outfiles
  
      def get_inputs(self):
          return self.infilelist
  
      def get_outputs(self):
          return self.outfilelist
  
      def get_outputs_for(self, filename):
          return self.outmap[filename]
  
      def get_generator(self):
          return self.generator
  
      def get_extra_args(self):
          return self.extra_args
  
  class Executable(BuildTarget):
      def __init__(self, name, subdir, subproject, is_cross, sources, objects, environment, kwargs):
          super().__init__(name, subdir, subproject, is_cross, sources, objects, environment, kwargs)
          # Unless overridden, executables have no suffix or prefix. Except on
          # Windows and with C#/Mono executables where the suffix is 'exe'
          if not hasattr(self, 'prefix'):
              self.prefix = ''
          if not hasattr(self, 'suffix'):
              # Executable for Windows or C#/Mono
              if (for_windows(is_cross, environment) or
                      for_cygwin(is_cross, environment) or 'cs' in self.compilers):
                  self.suffix = 'exe'
              else:
                  self.suffix = ''
          self.filename = self.name
          if self.suffix:
              self.filename += '.' + self.suffix
          self.outputs = [self.filename]
  
          # The import library this target will generate
          self.import_filename = None
          # The import library that Visual Studio would generate (and accept)
          self.vs_import_filename = None
          # The import library that GCC would generate (and prefer)
          self.gcc_import_filename = None
  
          # Check for export_dynamic
          self.export_dynamic = False
          if kwargs.get('export_dynamic'):
              if not isinstance(kwargs['export_dynamic'], bool):
                  raise InvalidArguments('"export_dynamic" keyword argument must be a boolean')
              self.export_dynamic = True
          if kwargs.get('implib'):
              self.export_dynamic = True
          if self.export_dynamic and kwargs.get('implib') is False:
              raise InvalidArguments('"implib" keyword argument must not be false for if "export_dynamic" is true')
  
          # If using export_dynamic, set the import library name
          if self.export_dynamic:
              implib_basename = self.name + '.exe'
              if not isinstance(kwargs.get('implib', False), bool):
                  implib_basename = kwargs['implib']
              if for_windows(is_cross, environment) or for_cygwin(is_cross, environment):
                  self.vs_import_filename = '{0}.lib'.format(implib_basename)
                  self.gcc_import_filename = 'lib{0}.a'.format(implib_basename)
                  if self.get_using_msvc():
                      self.import_filename = self.vs_import_filename
                  else:
                      self.import_filename = self.gcc_import_filename
  
          # Only linkwithable if using export_dynamic
          self.is_linkwithable = self.export_dynamic
  
      def type_suffix(self):
          return "@exe"
  
      def check_unknown_kwargs(self, kwargs):
          self.check_unknown_kwargs_int(kwargs, known_exe_kwargs)
  
      def get_import_filename(self):
          """
          The name of the import library that will be outputted by the compiler
  
          Returns None if there is no import library required for this platform
          """
          return self.import_filename
  
      def get_import_filenameslist(self):
          if self.import_filename:
              return [self.vs_import_filename, self.gcc_import_filename]
          return []
  
      def is_linkable_target(self):
          return self.is_linkwithable
  
  class StaticLibrary(BuildTarget):
      def __init__(self, name, subdir, subproject, is_cross, sources, objects, environment, kwargs):
          if 'pic' not in kwargs and 'b_staticpic' in environment.coredata.base_options:
              kwargs['pic'] = environment.coredata.base_options['b_staticpic'].value
          super().__init__(name, subdir, subproject, is_cross, sources, objects, environment, kwargs)
          if 'cs' in self.compilers:
              raise InvalidArguments('Static libraries not supported for C#.')
          if 'rust' in self.compilers:
              # If no crate type is specified, or it's the generic lib type, use rlib
              if not hasattr(self, 'rust_crate_type') or self.rust_crate_type == 'lib':
                  mlog.debug('Defaulting Rust static library target crate type to rlib')
                  self.rust_crate_type = 'rlib'
              # Don't let configuration proceed with a non-static crate type
              elif self.rust_crate_type not in ['rlib', 'staticlib']:
                  raise InvalidArguments('Crate type "{0}" invalid for static libraries; must be "rlib" or "staticlib"'.format(self.rust_crate_type))
          # By default a static library is named libfoo.a even on Windows because
          # MSVC does not have a consistent convention for what static libraries
          # are called. The MSVC CRT uses libfoo.lib syntax but nothing else uses
          # it and GCC only looks for static libraries called foo.lib and
          # libfoo.a. However, we cannot use foo.lib because that's the same as
          # the import library. Using libfoo.a is ok because people using MSVC
          # always pass the library filename while linking anyway.
          if not hasattr(self, 'prefix'):
              self.prefix = 'lib'
          if not hasattr(self, 'suffix'):
              if 'rust' in self.compilers:
                  if not hasattr(self, 'rust_crate_type') or self.rust_crate_type == 'rlib':
                      # default Rust static library suffix
                      self.suffix = 'rlib'
                  elif self.rust_crate_type == 'staticlib':
                      self.suffix = 'a'
              else:
                  self.suffix = 'a'
          self.filename = self.prefix + self.name + '.' + self.suffix
          self.outputs = [self.filename]
  
      def type_suffix(self):
          return "@sta"
  
      def check_unknown_kwargs(self, kwargs):
          self.check_unknown_kwargs_int(kwargs, known_lib_kwargs)
  
      def process_kwargs(self, kwargs, environment):
          super().process_kwargs(kwargs, environment)
          if 'rust_crate_type' in kwargs:
              rust_crate_type = kwargs['rust_crate_type']
              if isinstance(rust_crate_type, str):
                  self.rust_crate_type = rust_crate_type
              else:
                  raise InvalidArguments('Invalid rust_crate_type "{0}": must be a string.'.format(rust_crate_type))
  
      def is_linkable_target(self):
          return True
  
  class SharedLibrary(BuildTarget):
      def __init__(self, name, subdir, subproject, is_cross, sources, objects, environment, kwargs):
          self.soversion = None
          self.ltversion = None
          self.vs_module_defs = None
          # The import library this target will generate
          self.import_filename = None
          # The import library that Visual Studio would generate (and accept)
          self.vs_import_filename = None
          # The import library that GCC would generate (and prefer)
          self.gcc_import_filename = None
          super().__init__(name, subdir, subproject, is_cross, sources, objects, environment, kwargs)
          if 'rust' in self.compilers:
              # If no crate type is specified, or it's the generic lib type, use dylib
              if not hasattr(self, 'rust_crate_type') or self.rust_crate_type == 'lib':
                  mlog.debug('Defaulting Rust dynamic library target crate type to "dylib"')
                  self.rust_crate_type = 'dylib'
              # Don't let configuration proceed with a non-dynamic crate type
              elif self.rust_crate_type not in ['dylib', 'cdylib']:
                  raise InvalidArguments('Crate type "{0}" invalid for dynamic libraries; must be "dylib" or "cdylib"'.format(self.rust_crate_type))
          if not hasattr(self, 'prefix'):
              self.prefix = None
          if not hasattr(self, 'suffix'):
              self.suffix = None
          self.basic_filename_tpl = '{0.prefix}{0.name}.{0.suffix}'
          self.determine_filenames(is_cross, environment)
  
      def determine_filenames(self, is_cross, env):
          """
          See https://github.com/mesonbuild/meson/pull/417 for details.
  
          First we determine the filename template (self.filename_tpl), then we
          set the output filename (self.filename).
  
          The template is needed while creating aliases (self.get_aliases),
          which are needed while generating .so shared libraries for Linux.
  
          Besides this, there's also the import library name, which is only used
          on Windows since on that platform the linker uses a separate library
          called the "import library" during linking instead of the shared
          library (DLL). The toolchain will output an import library in one of
          two formats: GCC or Visual Studio.
  
          When we're building with Visual Studio, the import library that will be
          generated by the toolchain is self.vs_import_filename, and with
          MinGW/GCC, it's self.gcc_import_filename. self.import_filename will
          always contain the import library name this target will generate.
          """
          prefix = ''
          suffix = ''
          self.filename_tpl = self.basic_filename_tpl
          # If the user already provided the prefix and suffix to us, we don't
          # need to do any filename suffix/prefix detection.
          # NOTE: manual prefix/suffix override is currently only tested for C/C++
          if self.prefix is not None and self.suffix is not None:
              pass
          # C# and Mono
          elif 'cs' in self.compilers:
              prefix = ''
              suffix = 'dll'
              self.filename_tpl = '{0.prefix}{0.name}.{0.suffix}'
          # C, C++, Swift, Vala
          # Only Windows uses a separate import library for linking
          # For all other targets/platforms import_filename stays None
          elif for_windows(is_cross, env):
              suffix = 'dll'
              self.vs_import_filename = '{0}.lib'.format(self.name)
              self.gcc_import_filename = 'lib{0}.dll.a'.format(self.name)
              if self.get_using_msvc():
                  # Shared library is of the form foo.dll
                  prefix = ''
                  # Import library is called foo.lib
                  self.import_filename = self.vs_import_filename
              # Assume GCC-compatible naming
              else:
                  # Shared library is of the form libfoo.dll
                  prefix = 'lib'
                  # Import library is called libfoo.dll.a
                  self.import_filename = self.gcc_import_filename
              # Shared library has the soversion if it is defined
              if self.soversion:
                  self.filename_tpl = '{0.prefix}{0.name}-{0.soversion}.{0.suffix}'
              else:
                  self.filename_tpl = '{0.prefix}{0.name}.{0.suffix}'
          elif for_cygwin(is_cross, env):
              suffix = 'dll'
              self.gcc_import_filename = 'lib{0}.dll.a'.format(self.name)
              # Shared library is of the form cygfoo.dll
              # (ld --dll-search-prefix=cyg is the default)
              prefix = 'cyg'
              # Import library is called libfoo.dll.a
              self.import_filename = self.gcc_import_filename
              if self.soversion:
                  self.filename_tpl = '{0.prefix}{0.name}-{0.soversion}.{0.suffix}'
              else:
                  self.filename_tpl = '{0.prefix}{0.name}.{0.suffix}'
          elif for_darwin(is_cross, env):
              prefix = 'lib'
              suffix = 'dylib'
              # On macOS, the filename can only contain the major version
              if self.soversion:
                  # libfoo.X.dylib
                  self.filename_tpl = '{0.prefix}{0.name}.{0.soversion}.{0.suffix}'
              else:
                  # libfoo.dylib
                  self.filename_tpl = '{0.prefix}{0.name}.{0.suffix}'
          elif for_android(is_cross, env):
              prefix = 'lib'
              suffix = 'so'
              # Android doesn't support shared_library versioning
              self.filename_tpl = '{0.prefix}{0.name}.{0.suffix}'
          else:
              prefix = 'lib'
              suffix = 'so'
              if self.ltversion:
                  # libfoo.so.X[.Y[.Z]] (.Y and .Z are optional)
                  self.filename_tpl = '{0.prefix}{0.name}.{0.suffix}.{0.ltversion}'
              elif self.soversion:
                  # libfoo.so.X
                  self.filename_tpl = '{0.prefix}{0.name}.{0.suffix}.{0.soversion}'
              else:
                  # No versioning, libfoo.so
                  self.filename_tpl = '{0.prefix}{0.name}.{0.suffix}'
          if self.prefix is None:
              self.prefix = prefix
          if self.suffix is None:
              self.suffix = suffix
          self.filename = self.filename_tpl.format(self)
          self.outputs = [self.filename]
  
      def process_kwargs(self, kwargs, environment):
          super().process_kwargs(kwargs, environment)
  
          if not for_android(self.is_cross, self.environment):
              supports_versioning = True
          else:
              supports_versioning = False
  
          if supports_versioning:
              # Shared library version
              if 'version' in kwargs:
                  self.ltversion = kwargs['version']
                  if not isinstance(self.ltversion, str):
                      raise InvalidArguments('Shared library version needs to be a string, not ' + type(self.ltversion).__name__)
                  if not re.fullmatch(r'[0-9]+(\.[0-9]+){0,2}', self.ltversion):
                      raise InvalidArguments('Invalid Shared library version "{0}". Must be of the form X.Y.Z where all three are numbers. Y and Z are optional.'.format(self.ltversion))
              # Try to extract/deduce the soversion
              if 'soversion' in kwargs:
                  self.soversion = kwargs['soversion']
                  if isinstance(self.soversion, int):
                      self.soversion = str(self.soversion)
                  if not isinstance(self.soversion, str):
                      raise InvalidArguments('Shared library soversion is not a string or integer.')
              elif self.ltversion:
                  # library version is defined, get the soversion from that
                  # We replicate what Autotools does here and take the first
                  # number of the version by default.
                  self.soversion = self.ltversion.split('.')[0]
          # Visual Studio module-definitions file
          if 'vs_module_defs' in kwargs:
              path = kwargs['vs_module_defs']
              if hasattr(path, 'held_object'):
                  path = path.held_object
              if isinstance(path, str):
                  if os.path.isabs(path):
                      self.vs_module_defs = File.from_absolute_file(path)
                  else:
                      self.vs_module_defs = File.from_source_file(environment.source_dir, self.subdir, path)
                  self.link_depends.append(self.vs_module_defs)
              elif isinstance(path, File):
                  # When passing a generated file.
                  self.vs_module_defs = path
                  self.link_depends.append(path)
              elif hasattr(path, 'get_filename'):
                  # When passing output of a Custom Target
                  path = File.from_built_file(path.subdir, path.get_filename())
                  self.vs_module_defs = path
                  self.link_depends.append(path)
              else:
                  raise InvalidArguments(
                      'Shared library vs_module_defs must be either a string, '
                      'a file object or a Custom Target')
          if 'rust_crate_type' in kwargs:
              rust_crate_type = kwargs['rust_crate_type']
              if isinstance(rust_crate_type, str):
                  self.rust_crate_type = rust_crate_type
              else:
                  raise InvalidArguments('Invalid rust_crate_type "{0}": must be a string.'.format(rust_crate_type))
  
      def check_unknown_kwargs(self, kwargs):
          self.check_unknown_kwargs_int(kwargs, known_lib_kwargs)
  
      def get_import_filename(self):
          """
          The name of the import library that will be outputted by the compiler
  
          Returns None if there is no import library required for this platform
          """
          return self.import_filename
  
      def get_import_filenameslist(self):
          if self.import_filename:
              return [self.vs_import_filename, self.gcc_import_filename]
          return []
  
      def get_all_link_deps(self):
          return [self] + self.get_transitive_link_deps()
  
      def get_aliases(self):
          """
          If the versioned library name is libfoo.so.0.100.0, aliases are:
          * libfoo.so.0 (soversion) -> libfoo.so.0.100.0
          * libfoo.so (unversioned; for linking) -> libfoo.so.0
          Same for dylib:
          * libfoo.dylib (unversioned; for linking) -> libfoo.0.dylib
          """
          aliases = {}
          # Aliases are only useful with .so and .dylib libraries. Also if
          # there's no self.soversion (no versioning), we don't need aliases.
          if self.suffix not in ('so', 'dylib') or not self.soversion:
              return {}
          # With .so libraries, the minor and micro versions are also in the
          # filename. If ltversion != soversion we create an soversion alias:
          # libfoo.so.0 -> libfoo.so.0.100.0
          # Where libfoo.so.0.100.0 is the actual library
          if self.suffix == 'so' and self.ltversion and self.ltversion != self.soversion:
              alias_tpl = self.filename_tpl.replace('ltversion', 'soversion')
              ltversion_filename = alias_tpl.format(self)
              aliases[ltversion_filename] = self.filename
          # libfoo.so.0/libfoo.0.dylib is the actual library
          else:
              ltversion_filename = self.filename
          # Unversioned alias:
          #  libfoo.so -> libfoo.so.0
          #  libfoo.dylib -> libfoo.0.dylib
          aliases[self.basic_filename_tpl.format(self)] = ltversion_filename
          return aliases
  
      def type_suffix(self):
          return "@sha"
  
      def is_linkable_target(self):
          return True
  
  # A shared library that is meant to be used with dlopen rather than linking
  # into something else.
  class SharedModule(SharedLibrary):
      def __init__(self, name, subdir, subproject, is_cross, sources, objects, environment, kwargs):
          if 'version' in kwargs:
              raise MesonException('Shared modules must not specify the version kwarg.')
          if 'soversion' in kwargs:
              raise MesonException('Shared modules must not specify the soversion kwarg.')
          super().__init__(name, subdir, subproject, is_cross, sources, objects, environment, kwargs)
          self.import_filename = None
  
  class CustomTarget(Target):
      known_kwargs = {'input': True,
                      'output': True,
                      'command': True,
                      'capture': False,
                      'install': True,
                      'install_dir': True,
                      'build_always': True,
                      'depends': True,
                      'depend_files': True,
                      'depfile': True,
                      'build_by_default': True,
                      'override_options': True,
                      }
  
      def __init__(self, name, subdir, subproject, kwargs, absolute_paths=False):
          super().__init__(name, subdir, subproject, False)
          self.dependencies = []
          self.extra_depends = []
          self.depend_files = [] # Files that this target depends on but are not on the command line.
          self.depfile = None
          self.process_kwargs(kwargs)
          self.extra_files = []
          # Whether to use absolute paths for all files on the commandline
          self.absolute_paths = absolute_paths
          unknowns = []
          for k in kwargs:
              if k not in CustomTarget.known_kwargs:
                  unknowns.append(k)
          if len(unknowns) > 0:
              mlog.warning('Unknown keyword arguments in target %s: %s' %
                           (self.name, ', '.join(unknowns)))
  
      def __lt__(self, other):
          return self.get_id() < other.get_id()
  
      def __repr__(self):
          repr_str = "<{0} {1}: {2}>"
          return repr_str.format(self.__class__.__name__, self.get_id(), self.command)
  
      def get_id(self):
          return self.name + self.type_suffix()
  
      def get_target_dependencies(self):
          deps = self.dependencies[:]
          deps += self.extra_depends
          for c in self.sources:
              if hasattr(c, 'held_object'):
                  c = c.held_object
              if isinstance(c, (BuildTarget, CustomTarget)):
                  deps.append(c)
          return deps
  
      def get_transitive_build_target_deps(self):
          '''
          Recursively fetch the build targets that this custom target depends on,
          whether through `command:`, `depends:`, or `sources:` The recursion is
          only performed on custom targets.
          This is useful for setting PATH on Windows for finding required DLLs.
          F.ex, if you have a python script that loads a C module that links to
          other DLLs in your project.
          '''
          bdeps = set()
          deps = self.get_target_dependencies()
          for d in deps:
              if isinstance(d, BuildTarget):
                  bdeps.add(d)
              elif isinstance(d, CustomTarget):
                  bdeps.update(d.get_transitive_build_target_deps())
          return bdeps
  
      def flatten_command(self, cmd):
          cmd = listify(cmd, unholder=True)
          final_cmd = []
          for c in cmd:
              if isinstance(c, str):
                  final_cmd.append(c)
              elif isinstance(c, File):
                  self.depend_files.append(c)
                  final_cmd.append(c)
              elif isinstance(c, dependencies.ExternalProgram):
                  if not c.found():
                      m = 'Tried to use not-found external program {!r} in "command"'
                      raise InvalidArguments(m.format(c.name))
                  self.depend_files.append(File.from_absolute_file(c.get_path()))
                  final_cmd += c.get_command()
              elif isinstance(c, (BuildTarget, CustomTarget)):
                  self.dependencies.append(c)
                  final_cmd.append(c)
              elif isinstance(c, list):
                  final_cmd += self.flatten_command(c)
              else:
                  raise InvalidArguments('Argument {!r} in "command" is invalid'.format(c))
          return final_cmd
  
      def process_kwargs(self, kwargs):
          super().process_kwargs(kwargs)
          self.sources = extract_as_list(kwargs, 'input', unholder=True)
          if 'output' not in kwargs:
              raise InvalidArguments('Missing keyword argument "output".')
          self.outputs = listify(kwargs['output'])
          # This will substitute values from the input into output and return it.
          inputs = get_sources_string_names(self.sources)
          values = get_filenames_templates_dict(inputs, [])
          for i in self.outputs:
              if not(isinstance(i, str)):
                  raise InvalidArguments('Output argument not a string.')
              if i == '':
                  raise InvalidArguments('Output must not be empty.')
              if i.strip() == '':
                  raise InvalidArguments('Output must not consist only of whitespace.')
              if '/' in i:
                  raise InvalidArguments('Output must not contain a path segment.')
              if '@INPUT@' in i or '@INPUT0@' in i:
                  m = 'Output cannot contain @INPUT@ or @INPUT0@, did you ' \
                      'mean @PLAINNAME@ or @BASENAME@?'
                  raise InvalidArguments(m)
              # We already check this during substitution, but the error message
              # will be unclear/confusing, so check it here.
              if len(inputs) != 1 and ('@PLAINNAME@' in i or '@BASENAME@' in i):
                  m = "Output cannot contain @PLAINNAME@ or @BASENAME@ when " \
                      "there is more than one input (we can't know which to use)"
                  raise InvalidArguments(m)
          self.outputs = substitute_values(self.outputs, values)
          self.capture = kwargs.get('capture', False)
          if self.capture and len(self.outputs) != 1:
              raise InvalidArguments('Capturing can only output to a single file.')
          if 'command' not in kwargs:
              raise InvalidArguments('Missing keyword argument "command".')
          if 'depfile' in kwargs:
              depfile = kwargs['depfile']
              if not isinstance(depfile, str):
                  raise InvalidArguments('Depfile must be a string.')
              if os.path.basename(depfile) != depfile:
                  raise InvalidArguments('Depfile must be a plain filename without a subdirectory.')
              self.depfile = depfile
          self.command = self.flatten_command(kwargs['command'])
          if self.capture:
              for c in self.command:
                  if isinstance(c, str) and '@OUTPUT@' in c:
                      raise InvalidArguments('@OUTPUT@ is not allowed when capturing output.')
          if 'install' in kwargs:
              self.install = kwargs['install']
              if not isinstance(self.install, bool):
                  raise InvalidArguments('"install" must be boolean.')
              if self.install:
                  if 'install_dir' not in kwargs:
                      raise InvalidArguments('"install_dir" must be specified '
                                             'when installing a target')
                  # If an item in this list is False, the output corresponding to
                  # the list index of that item will not be installed
                  self.install_dir = typeslistify(kwargs['install_dir'], (str, bool))
          else:
              self.install = False
              self.install_dir = [None]
          self.build_always = kwargs.get('build_always', False)
          if not isinstance(self.build_always, bool):
              raise InvalidArguments('Argument build_always must be a boolean.')
          extra_deps, depend_files = extract_as_list(kwargs, 'depends', 'depend_files', pop = False)
          for ed in extra_deps:
              while hasattr(ed, 'held_object'):
                  ed = ed.held_object
              if not isinstance(ed, (CustomTarget, BuildTarget)):
                  raise InvalidArguments('Can only depend on toplevel targets: custom_target or build_target (executable or a library)')
              self.extra_depends.append(ed)
          for i in depend_files:
              if isinstance(i, (File, str)):
                  self.depend_files.append(i)
              else:
                  mlog.debug(i)
                  raise InvalidArguments('Unknown type {!r} in depend_files.'.format(type(i).__name__))
  
      def get_dependencies(self):
          return self.dependencies
  
      def should_install(self):
          return self.install
  
      def get_custom_install_dir(self):
          return self.install_dir
  
      def get_outputs(self):
          return self.outputs
  
      def get_filename(self):
          return self.outputs[0]
  
      def get_sources(self):
          return self.sources
  
      def get_generated_lists(self):
          genlists = []
          for c in self.sources:
              if hasattr(c, 'held_object'):
                  c = c.held_object
              if isinstance(c, GeneratedList):
                  genlists.append(c)
          return genlists
  
      def get_generated_sources(self):
          return self.get_generated_lists()
  
      def type_suffix(self):
          return "@cus"
  
      def __getitem__(self, index):
          return CustomTargetIndex(self, self.outputs[index])
  
      def __setitem__(self, index, value):
          raise NotImplementedError
  
      def __delitem__(self, index):
          raise NotImplementedError
  
  class RunTarget(Target):
      def __init__(self, name, command, args, dependencies, subdir, subproject):
          super().__init__(name, subdir, subproject, False)
          self.command = command
          self.args = args
          self.dependencies = dependencies
  
      def __lt__(self, other):
          return self.get_id() < other.get_id()
  
      def __repr__(self):
          repr_str = "<{0} {1}: {2}>"
          return repr_str.format(self.__class__.__name__, self.get_id(), self.command)
  
      def get_dependencies(self):
          return self.dependencies
  
      def get_generated_sources(self):
          return []
  
      def get_sources(self):
          return []
  
      def should_install(self):
          return False
  
      def get_filename(self):
          return self.name
  
      def type_suffix(self):
          return "@run"
  
  class Jar(BuildTarget):
      def __init__(self, name, subdir, subproject, is_cross, sources, objects, environment, kwargs):
          super().__init__(name, subdir, subproject, is_cross, sources, objects, environment, kwargs)
          for s in self.sources:
              if not s.endswith('.java'):
                  raise InvalidArguments('Jar source %s is not a java file.' % s)
          self.filename = self.name + '.jar'
          self.outputs = [self.filename]
          self.java_args = kwargs.get('java_args', [])
  
      def get_main_class(self):
          return self.main_class
  
      def type_suffix(self):
          return "@jar"
  
      def get_java_args(self):
          return self.java_args
  
      def validate_cross_install(self, environment):
          # All jar targets are installable.
          pass
  
  
  class CustomTargetIndex:
  
      """A special opaque object returned by indexing a CustomTarget. This object
      exists in meson, but acts as a proxy in the backends, making targets depend
      on the CustomTarget it's derived from, but only adding one source file to
      the sources.
      """
  
      def __init__(self, target, output):
          self.target = target
          self.output = output
  
      def __repr__(self):
          return '<CustomTargetIndex: {!r}[{}]>'.format(
              self.target, self.target.get_outputs().index(self.output))
  
      def get_outputs(self):
          return [self.output]
  
      def get_subdir(self):
          return self.target.get_subdir()
  
  
  class ConfigureFile:
  
      def __init__(self, subdir, sourcename, targetname, configuration_data):
          self.subdir = subdir
          self.sourcename = sourcename
          self.targetname = targetname
          self.configuration_data = configuration_data
  
      def __repr__(self):
          repr_str = "<{0}: {1} -> {2}>"
          src = os.path.join(self.subdir, self.sourcename)
          dst = os.path.join(self.subdir, self.targetname)
          return repr_str.format(self.__class__.__name__, src, dst)
  
      def get_configuration_data(self):
          return self.configuration_data
  
      def get_subdir(self):
          return self.subdir
  
      def get_source_name(self):
          return self.sourcename
  
      def get_target_name(self):
          return self.targetname
  
  class ConfigurationData:
      def __init__(self):
          super().__init__()
          self.values = {}
  
      def __repr__(self):
          return repr(self.values)
  
      def __contains__(self, value):
          return value in self.values
  
      def get(self, name):
          return self.values[name] # (val, desc)
  
      def keys(self):
          return self.values.keys()
  
  # A bit poorly named, but this represents plain data files to copy
  # during install.
  class Data:
      def __init__(self, sources, install_dir, install_mode=None):
          self.sources = sources
          self.install_dir = install_dir
          self.install_mode = install_mode
          self.sources = listify(self.sources)
          for s in self.sources:
              assert(isinstance(s, File))
  
  class RunScript(dict):
      def __init__(self, script, args):
          super().__init__()
          assert(isinstance(script, list))
          assert(isinstance(args, list))
          self['exe'] = script
          self['args'] = args
  
  class TestSetup:
      def __init__(self, *, exe_wrapper=None, gdb=None, timeout_multiplier=None, env=None):
          self.exe_wrapper = exe_wrapper
          self.gdb = gdb
          self.timeout_multiplier = timeout_multiplier
          self.env = env
  
  def get_sources_string_names(sources):
      '''
      For the specified list of @sources which can be strings, Files, or targets,
      get all the output basenames.
      '''
      names = []
      for s in sources:
          if hasattr(s, 'held_object'):
              s = s.held_object
          if isinstance(s, str):
              names.append(s)
          elif isinstance(s, (BuildTarget, CustomTarget, GeneratedList)):
              names += s.get_outputs()
          elif isinstance(s, File):
              names.append(s.fname)
          else:
              raise AssertionError('Unknown source type: {!r}'.format(s))
      return names
  