# 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.

from . import mparser
from . import environment
from . import coredata
from . import dependencies
from . import mlog
from . import build
from . import optinterpreter
from . import compilers
from .wrap import wrap
from . import mesonlib
from .mesonlib import FileMode, Popen_safe
from .dependencies import InternalDependency, Dependency
from .interpreterbase import InterpreterBase
from .interpreterbase import check_stringlist, noPosargs, noKwargs, stringArgs
from .interpreterbase import InterpreterException, InvalidArguments, InvalidCode
from .interpreterbase import InterpreterObject, MutableInterpreterObject
from .modules import ModuleReturnValue

import os, sys, shutil, uuid
import re

import importlib

run_depr_printed = False

def stringifyUserArguments(args):
    if isinstance(args, list):
        return '[%s]' % ', '.join([stringifyUserArguments(x) for x in args])
    elif isinstance(args, int):
        return str(args)
    elif isinstance(args, str):
        return "'%s'" % args
    raise InvalidArguments('Function accepts only strings, integers, lists and lists thereof.')


class TryRunResultHolder(InterpreterObject):
    def __init__(self, res):
        super().__init__()
        self.res = res
        self.methods.update({'returncode': self.returncode_method,
                             'compiled': self.compiled_method,
                             'stdout': self.stdout_method,
                             'stderr': self.stderr_method,
                             })

    def returncode_method(self, args, kwargs):
        return self.res.returncode

    def compiled_method(self, args, kwargs):
        return self.res.compiled

    def stdout_method(self, args, kwargs):
        return self.res.stdout

    def stderr_method(self, args, kwargs):
        return self.res.stderr

class RunProcess(InterpreterObject):

    def __init__(self, command_array, source_dir, build_dir, subdir, in_builddir=False):
        super().__init__()
        pc, self.stdout, self.stderr = self.run_command(command_array, source_dir, build_dir, subdir, in_builddir)
        self.returncode = pc.returncode
        self.methods.update({'returncode': self.returncode_method,
                             'stdout': self.stdout_method,
                             'stderr': self.stderr_method,
                             })

    def run_command(self, command_array, source_dir, build_dir, subdir, in_builddir):
        cmd_name = command_array[0]
        env = {'MESON_SOURCE_ROOT': source_dir,
               'MESON_BUILD_ROOT': build_dir,
               'MESON_SUBDIR': subdir}
        if in_builddir:
            cwd = os.path.join(build_dir, subdir)
        else:
            cwd = os.path.join(source_dir, subdir)
        child_env = os.environ.copy()
        child_env.update(env)
        mlog.debug('Running command:', ' '.join(command_array))
        try:
            return Popen_safe(command_array, env=child_env, cwd=cwd)
        except FileNotFoundError:
            pass
        # Was not a command, is a program in path?
        exe = shutil.which(cmd_name)
        if exe is not None:
            command_array = [exe] + command_array[1:]
            return Popen_safe(command_array, env=child_env, cwd=cwd)
        # No? Maybe it is a script in the source tree.
        fullpath = os.path.join(source_dir, subdir, cmd_name)
        command_array = [fullpath] + command_array[1:]
        try:
            return Popen_safe(command_array, env=child_env, cwd=cwd)
        except FileNotFoundError:
            raise InterpreterException('Could not execute command "%s".' % cmd_name)

    def returncode_method(self, args, kwargs):
        return self.returncode

    def stdout_method(self, args, kwargs):
        return self.stdout

    def stderr_method(self, args, kwargs):
        return self.stderr

class ConfigureFileHolder(InterpreterObject):

    def __init__(self, subdir, sourcename, targetname, configuration_data):
        InterpreterObject.__init__(self)
        self.held_object = build.ConfigureFile(subdir, sourcename, targetname, configuration_data)


class EnvironmentVariablesHolder(MutableInterpreterObject):
    def __init__(self):
        super().__init__()
        self.held_object = build.EnvironmentVariables()
        self.methods.update({'set': self.set_method,
                             'append': self.append_method,
                             'prepend': self.prepend_method,
                             })

    @stringArgs
    def add_var(self, method, args, kwargs):
        if not isinstance(kwargs.get("separator", ""), str):
            raise InterpreterException("EnvironmentVariablesHolder methods 'separator'"
                                       " argument needs to be a string.")
        if len(args) < 2:
            raise InterpreterException("EnvironmentVariablesHolder methods require at least"
                                       "2 arguments, first is the name of the variable and"
                                       " following one are values")
        self.held_object.envvars.append((method, args[0], args[1:], kwargs))

    def set_method(self, args, kwargs):
        self.add_var(self.held_object.set, args, kwargs)

    def append_method(self, args, kwargs):
        self.add_var(self.held_object.append, args, kwargs)

    def prepend_method(self, args, kwargs):
        self.add_var(self.held_object.prepend, args, kwargs)


class ConfigurationDataHolder(MutableInterpreterObject):
    def __init__(self):
        super().__init__()
        self.used = False # These objects become immutable after use in configure_file.
        self.held_object = build.ConfigurationData()
        self.methods.update({'set': self.set_method,
                             'set10': self.set10_method,
                             'set_quoted': self.set_quoted_method,
                             'has': self.has_method,
                             'get': self.get_method,
                             })

    def is_used(self):
        return self.used

    def mark_used(self):
        self.used = True

    def validate_args(self, args, kwargs):
        if len(args) != 2:
            raise InterpreterException("Configuration set requires 2 arguments.")
        if self.used:
            raise InterpreterException("Can not set values on configuration object that has been used.")
        name = args[0]
        val = args[1]
        desc = kwargs.get('description', None)
        if not isinstance(name, str):
            raise InterpreterException("First argument to set must be a string.")
        if desc is not None and not isinstance(desc, str):
            raise InterpreterException('Description must be a string.')

        return name, val, desc

    def set_method(self, args, kwargs):
        (name, val, desc) = self.validate_args(args, kwargs)
        self.held_object.values[name] = (val, desc)

    def set_quoted_method(self, args, kwargs):
        (name, val, desc) = self.validate_args(args, kwargs)
        if not isinstance(val, str):
            raise InterpreterException("Second argument to set_quoted must be a string.")
        escaped_val = '\\"'.join(val.split('"'))
        self.held_object.values[name] = ('"' + escaped_val + '"', desc)

    def set10_method(self, args, kwargs):
        (name, val, desc) = self.validate_args(args, kwargs)
        if val:
            self.held_object.values[name] = (1, desc)
        else:
            self.held_object.values[name] = (0, desc)

    def has_method(self, args, kwargs):
        return args[0] in self.held_object.values

    def get_method(self, args, kwargs):
        if len(args) < 1 or len(args) > 2:
            raise InterpreterException('Get method takes one or two arguments.')
        name = args[0]
        if name in self.held_object:
            return self.held_object.get(name)[0]
        if len(args) > 1:
            return args[1]
        raise InterpreterException('Entry %s not in configuration data.' % name)

    def get(self, name):
        return self.held_object.values[name]     # (val, desc)

    def keys(self):
        return self.held_object.values.keys()

# Interpreter objects can not be pickled so we must have
# these wrappers.

class DependencyHolder(InterpreterObject):
    def __init__(self, dep):
        InterpreterObject.__init__(self)
        self.held_object = dep
        self.methods.update({'found': self.found_method,
                             'type_name': self.type_name_method,
                             'version': self.version_method,
                             'get_pkgconfig_variable': self.pkgconfig_method,
                             })

    def type_name_method(self, args, kwargs):
        return self.held_object.type_name

    def found_method(self, args, kwargs):
        if self.held_object.type_name == 'internal':
            return True

        return self.held_object.found()

    def version_method(self, args, kwargs):
        return self.held_object.get_version()

    def pkgconfig_method(self, args, kwargs):
        if not isinstance(args, list):
            args = [args]
        if len(args) != 1:
            raise InterpreterException('get_pkgconfig_variable takes exactly one argument.')
        varname = args[0]
        if not isinstance(varname, str):
            raise InterpreterException('Variable name must be a string.')
        return self.held_object.get_pkgconfig_variable(varname)

class InternalDependencyHolder(InterpreterObject):
    def __init__(self, dep):
        InterpreterObject.__init__(self)
        self.held_object = dep
        self.methods.update({'found': self.found_method,
                             'version': self.version_method,
                             })

    def found_method(self, args, kwargs):
        return True

    def version_method(self, args, kwargs):
        return self.held_object.get_version()

class ExternalProgramHolder(InterpreterObject):
    def __init__(self, ep):
        InterpreterObject.__init__(self)
        self.held_object = ep
        self.methods.update({'found': self.found_method,
                             'path': self.path_method})

    def found_method(self, args, kwargs):
        return self.found()

    def path_method(self, args, kwargs):
        return self.get_command()

    def found(self):
        return self.held_object.found()

    def get_command(self):
        return self.held_object.fullpath

    def get_name(self):
        return self.held_object.name

class ExternalLibraryHolder(InterpreterObject):
    def __init__(self, el):
        InterpreterObject.__init__(self)
        self.held_object = el
        self.methods.update({'found': self.found_method})

    def found(self):
        return self.held_object.found()

    def found_method(self, args, kwargs):
        return self.found()

    def get_filename(self):
        return self.held_object.fullpath

    def get_name(self):
        return self.held_object.name

    def get_compile_args(self):
        return self.held_object.get_compile_args()

    def get_link_args(self):
        return self.held_object.get_link_args()

    def get_exe_args(self):
        return self.held_object.get_exe_args()

class GeneratorHolder(InterpreterObject):
    def __init__(self, interpreter, args, kwargs):
        super().__init__()
        self.interpreter = interpreter
        self.held_object = build.Generator(args, kwargs)
        self.methods.update({'process': self.process_method})

    def process_method(self, args, kwargs):
        extras = mesonlib.stringlistify(kwargs.get('extra_args', []))
        gl = self.held_object.process_files('Generator', args, self.interpreter, extra_args=extras)
        return GeneratedListHolder(gl)


class GeneratedListHolder(InterpreterObject):
    def __init__(self, arg1, extra_args=[]):
        super().__init__()
        if isinstance(arg1, GeneratorHolder):
            self.held_object = build.GeneratedList(arg1.held_object, extra_args)
        else:
            self.held_object = arg1

    def __repr__(self):
        r = '<{}: {!r}>'
        return r.format(self.__class__.__name__, self.held_object.get_outputs())

    def add_file(self, a):
        self.held_object.add_file(a)

class BuildMachine(InterpreterObject):
    def __init__(self, compilers):
        self.compilers = compilers
        InterpreterObject.__init__(self)
        self.held_object = environment.MachineInfo(environment.detect_system(),
                                                   environment.detect_cpu_family(self.compilers),
                                                   environment.detect_cpu(self.compilers),
                                                   sys.byteorder)
        self.methods.update({'system': self.system_method,
                             'cpu_family': self.cpu_family_method,
                             'cpu': self.cpu_method,
                             'endian': self.endian_method,
                             })

    def cpu_family_method(self, args, kwargs):
        return self.held_object.cpu_family

    def cpu_method(self, args, kwargs):
        return self.held_object.cpu

    def system_method(self, args, kwargs):
        return self.held_object.system

    def endian_method(self, args, kwargs):
        return self.held_object.endian

# This class will provide both host_machine and
# target_machine
class CrossMachineInfo(InterpreterObject):
    def __init__(self, cross_info):
        InterpreterObject.__init__(self)
        minimum_cross_info = {'cpu', 'cpu_family', 'endian', 'system'}
        if set(cross_info) < minimum_cross_info:
            raise InterpreterException(
                'Machine info is currently {}\n'.format(cross_info) +
                'but is missing {}.'.format(minimum_cross_info - set(cross_info)))
        self.info = cross_info
        self.held_object = environment.MachineInfo(cross_info['system'],
                                                   cross_info['cpu_family'],
                                                   cross_info['cpu'],
                                                   cross_info['endian'])
        self.methods.update({'system': self.system_method,
                             'cpu': self.cpu_method,
                             'cpu_family': self.cpu_family_method,
                             'endian': self.endian_method,
                             })

    def cpu_family_method(self, args, kwargs):
        return self.held_object.cpu_family

    def cpu_method(self, args, kwargs):
        return self.held_object.cpu

    def system_method(self, args, kwargs):
        return self.held_object.system

    def endian_method(self, args, kwargs):
        return self.held_object.endian

class IncludeDirsHolder(InterpreterObject):
    def __init__(self, idobj):
        super().__init__()
        self.held_object = idobj

class Headers(InterpreterObject):

    def __init__(self, sources, kwargs):
        InterpreterObject.__init__(self)
        self.sources = sources
        self.install_subdir = kwargs.get('subdir', '')
        self.custom_install_dir = kwargs.get('install_dir', None)
        if self.custom_install_dir is not None:
            if not isinstance(self.custom_install_dir, str):
                raise InterpreterException('Custom_install_dir must be a string.')

    def set_install_subdir(self, subdir):
        self.install_subdir = subdir

    def get_install_subdir(self):
        return self.install_subdir

    def get_sources(self):
        return self.sources

    def get_custom_install_dir(self):
        return self.custom_install_dir

class DataHolder(InterpreterObject):
    def __init__(self, data):
        super().__init__()
        self.held_object = data

    def get_source_subdir(self):
        return self.held_object.source_subdir

    def get_sources(self):
        return self.held_object.sources

    def get_install_dir(self):
        return self.held_object.install_dir

class InstallDir(InterpreterObject):
    def __init__(self, src_subdir, inst_subdir, install_dir, install_mode):
        InterpreterObject.__init__(self)
        self.source_subdir = src_subdir
        self.installable_subdir = inst_subdir
        self.install_dir = install_dir
        self.install_mode = install_mode

class Man(InterpreterObject):

    def __init__(self, source_subdir, sources, kwargs):
        InterpreterObject.__init__(self)
        self.source_subdir = source_subdir
        self.sources = sources
        self.validate_sources()
        if len(kwargs) > 1:
            raise InvalidArguments('Man function takes at most one keyword arguments.')
        self.custom_install_dir = kwargs.get('install_dir', None)
        if self.custom_install_dir is not None and not isinstance(self.custom_install_dir, str):
            raise InterpreterException('Custom_install_dir must be a string.')

    def validate_sources(self):
        for s in self.sources:
            try:
                num = int(s.split('.')[-1])
            except (IndexError, ValueError):
                num = 0
            if num < 1 or num > 8:
                raise InvalidArguments('Man file must have a file extension of a number between 1 and 8')

    def get_custom_install_dir(self):
        return self.custom_install_dir

    def get_sources(self):
        return self.sources

    def get_source_subdir(self):
        return self.source_subdir

class GeneratedObjectsHolder(InterpreterObject):
    def __init__(self, held_object):
        super().__init__()
        self.held_object = held_object

class TargetHolder(InterpreterObject):
    def __init__(self):
        super().__init__()

class BuildTargetHolder(TargetHolder):
    def __init__(self, target, interp):
        super().__init__()
        self.held_object = target
        self.interpreter = interp
        self.methods.update({'extract_objects': self.extract_objects_method,
                             'extract_all_objects': self.extract_all_objects_method,
                             'get_id': self.get_id_method,
                             'outdir': self.outdir_method,
                             'full_path': self.full_path_method,
                             'private_dir_include': self.private_dir_include_method,
                             })

    def __repr__(self):
        r = '<{} {}: {}>'
        h = self.held_object
        return r.format(self.__class__.__name__, h.get_id(), h.filename)

    def is_cross(self):
        return self.held_object.is_cross()

    def private_dir_include_method(self, args, kwargs):
        return IncludeDirsHolder(build.IncludeDirs('', [], False,
                                                   [self.interpreter.backend.get_target_private_dir(self.held_object)]))

    def full_path_method(self, args, kwargs):
        return self.interpreter.backend.get_target_filename_abs(self.held_object)

    def outdir_method(self, args, kwargs):
        return self.interpreter.backend.get_target_dir(self.held_object)

    def extract_objects_method(self, args, kwargs):
        gobjs = self.held_object.extract_objects(args)
        return GeneratedObjectsHolder(gobjs)

    def extract_all_objects_method(self, args, kwargs):
        gobjs = self.held_object.extract_all_objects()
        return GeneratedObjectsHolder(gobjs)

    def get_id_method(self, args, kwargs):
        return self.held_object.get_id()

class ExecutableHolder(BuildTargetHolder):
    def __init__(self, target, interp):
        super().__init__(target, interp)

class StaticLibraryHolder(BuildTargetHolder):
    def __init__(self, target, interp):
        super().__init__(target, interp)

class SharedLibraryHolder(BuildTargetHolder):
    def __init__(self, target, interp):
        super().__init__(target, interp)

class SharedModuleHolder(BuildTargetHolder):
    def __init__(self, target, interp):
        super().__init__(target, interp)

class JarHolder(BuildTargetHolder):
    def __init__(self, target, interp):
        super().__init__(target, interp)

class CustomTargetHolder(TargetHolder):
    def __init__(self, object_to_hold, interp):
        super().__init__()
        self.held_object = object_to_hold
        self.interpreter = interp
        self.methods.update({'full_path': self.full_path_method,
                             })

    def __repr__(self):
        r = '<{} {}: {}>'
        h = self.held_object
        return r.format(self.__class__.__name__, h.get_id(), h.command)

    def full_path_method(self, args, kwargs):
        return self.interpreter.backend.get_target_filename_abs(self.held_object)

class RunTargetHolder(InterpreterObject):
    def __init__(self, name, command, args, dependencies, subdir):
        self.held_object = build.RunTarget(name, command, args, dependencies, subdir)

    def __repr__(self):
        r = '<{} {}: {}>'
        h = self.held_object
        return r.format(self.__class__.__name__, h.get_id(), h.command)

class Test(InterpreterObject):
    def __init__(self, name, suite, exe, is_parallel, cmd_args, env, should_fail, timeout, workdir):
        InterpreterObject.__init__(self)
        self.name = name
        self.suite = suite
        self.exe = exe
        self.is_parallel = is_parallel
        self.cmd_args = cmd_args
        self.env = env
        self.should_fail = should_fail
        self.timeout = timeout
        self.workdir = workdir

    def get_exe(self):
        return self.exe

    def get_name(self):
        return self.name

class SubprojectHolder(InterpreterObject):

    def __init__(self, subinterpreter):
        super().__init__()
        self.held_object = subinterpreter
        self.methods.update({'get_variable': self.get_variable_method,
                             })

    def get_variable_method(self, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('Get_variable takes one argument.')
        varname = args[0]
        if not isinstance(varname, str):
            raise InterpreterException('Get_variable takes a string argument.')
        return self.held_object.variables[varname]

class CompilerHolder(InterpreterObject):
    def __init__(self, compiler, env):
        InterpreterObject.__init__(self)
        self.compiler = compiler
        self.environment = env
        self.methods.update({'compiles': self.compiles_method,
                             'links': self.links_method,
                             'get_id': self.get_id_method,
                             'sizeof': self.sizeof_method,
                             'has_header': self.has_header_method,
                             'has_header_symbol': self.has_header_symbol_method,
                             'run': self.run_method,
                             'has_function': self.has_function_method,
                             'has_member': self.has_member_method,
                             'has_members': self.has_members_method,
                             'has_type': self.has_type_method,
                             'alignment': self.alignment_method,
                             'version': self.version_method,
                             'cmd_array': self.cmd_array_method,
                             'find_library': self.find_library_method,
                             'has_argument': self.has_argument_method,
                             'has_multi_arguments': self.has_multi_arguments_method,
                             'first_supported_argument': self.first_supported_argument_method,
                             'unittest_args': self.unittest_args_method,
                             'symbols_have_underscore_prefix': self.symbols_have_underscore_prefix_method,
                             })

    def version_method(self, args, kwargs):
        return self.compiler.version

    def cmd_array_method(self, args, kwargs):
        return self.compiler.exelist

    def determine_args(self, kwargs):
        nobuiltins = kwargs.get('no_builtin_args', False)
        if not isinstance(nobuiltins, bool):
            raise InterpreterException('Type of no_builtin_args not a boolean.')
        args = []
        incdirs = kwargs.get('include_directories', [])
        if not isinstance(incdirs, list):
            incdirs = [incdirs]
        for i in incdirs:
            if not isinstance(i, IncludeDirsHolder):
                raise InterpreterException('Include directories argument must be an include_directories object.')
            for idir in i.held_object.get_incdirs():
                idir = os.path.join(self.environment.get_source_dir(), idir)
                args += self.compiler.get_include_args(idir, False)
        if not nobuiltins:
            opts = self.environment.coredata.compiler_options
            args += self.compiler.get_option_compile_args(opts)
            args += self.compiler.get_option_link_args(opts)
        args += mesonlib.stringlistify(kwargs.get('args', []))
        return args

    def determine_dependencies(self, kwargs):
        deps = kwargs.get('dependencies', None)
        if deps is not None:
            if not isinstance(deps, list):
                deps = [deps]
            final_deps = []
            for d in deps:
                try:
                    d = d.held_object
                except Exception:
                    pass
                if isinstance(d, InternalDependency) or not isinstance(d, Dependency):
                    raise InterpreterException('Dependencies must be external dependencies')
                final_deps.append(d)
            deps = final_deps
        return deps

    def alignment_method(self, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('Alignment method takes exactly one positional argument.')
        check_stringlist(args)
        typename = args[0]
        extra_args = mesonlib.stringlistify(kwargs.get('args', []))
        result = self.compiler.alignment(typename, self.environment, extra_args)
        mlog.log('Checking for alignment of "', mlog.bold(typename), '": ', result, sep='')
        return result

    def run_method(self, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('Run method takes exactly one positional argument.')
        code = args[0]
        if isinstance(code, mesonlib.File):
            code = mesonlib.File.from_absolute_file(
                code.rel_to_builddir(self.environment.source_dir))
        elif not isinstance(code, str):
            raise InvalidArguments('Argument must be string or file.')
        testname = kwargs.get('name', '')
        if not isinstance(testname, str):
            raise InterpreterException('Testname argument must be a string.')
        extra_args = self.determine_args(kwargs)
        deps = self.determine_dependencies(kwargs)
        result = self.compiler.run(code, self.environment, extra_args, deps)
        if len(testname) > 0:
            if not result.compiled:
                h = mlog.red('DID NOT COMPILE')
            elif result.returncode == 0:
                h = mlog.green('YES')
            else:
                h = mlog.red('NO (%d)' % result.returncode)
            mlog.log('Checking if "', mlog.bold(testname), '" runs: ', h, sep='')
        return TryRunResultHolder(result)

    def get_id_method(self, args, kwargs):
        return self.compiler.get_id()

    def symbols_have_underscore_prefix_method(self, args, kwargs):
        '''
        Check if the compiler prefixes _ (underscore) to global C symbols
        See: https://en.wikipedia.org/wiki/Name_mangling#C
        '''
        return self.compiler.symbols_have_underscore_prefix(self.environment)

    def unittest_args_method(self, args, kwargs):
        # At time, only D compilers have this feature.
        if not hasattr(self.compiler, 'get_unittest_args'):
            raise InterpreterException('This {} compiler has no unittest arguments.'.format(self.compiler.language))
        return self.compiler.get_unittest_args()

    def has_member_method(self, args, kwargs):
        if len(args) != 2:
            raise InterpreterException('Has_member takes exactly two arguments.')
        check_stringlist(args)
        typename = args[0]
        membername = args[1]
        prefix = kwargs.get('prefix', '')
        if not isinstance(prefix, str):
            raise InterpreterException('Prefix argument of has_member must be a string.')
        extra_args = self.determine_args(kwargs)
        deps = self.determine_dependencies(kwargs)
        had = self.compiler.has_members(typename, [membername], prefix,
                                        self.environment, extra_args, deps)
        if had:
            hadtxt = mlog.green('YES')
        else:
            hadtxt = mlog.red('NO')
        mlog.log('Checking whether type "', mlog.bold(typename),
                 '" has member "', mlog.bold(membername), '": ', hadtxt, sep='')
        return had

    def has_members_method(self, args, kwargs):
        check_stringlist(args)
        typename = args[0]
        membernames = args[1:]
        prefix = kwargs.get('prefix', '')
        if not isinstance(prefix, str):
            raise InterpreterException('Prefix argument of has_members must be a string.')
        extra_args = self.determine_args(kwargs)
        deps = self.determine_dependencies(kwargs)
        had = self.compiler.has_members(typename, membernames, prefix,
                                        self.environment, extra_args, deps)
        if had:
            hadtxt = mlog.green('YES')
        else:
            hadtxt = mlog.red('NO')
        members = mlog.bold(', '.join(['"{}"'.format(m) for m in membernames]))
        mlog.log('Checking whether type "', mlog.bold(typename),
                 '" has members ', members, ': ', hadtxt, sep='')
        return had

    def has_function_method(self, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('Has_function takes exactly one argument.')
        check_stringlist(args)
        funcname = args[0]
        prefix = kwargs.get('prefix', '')
        if not isinstance(prefix, str):
            raise InterpreterException('Prefix argument of has_function must be a string.')
        extra_args = self.determine_args(kwargs)
        deps = self.determine_dependencies(kwargs)
        had = self.compiler.has_function(funcname, prefix, self.environment, extra_args, deps)
        if had:
            hadtxt = mlog.green('YES')
        else:
            hadtxt = mlog.red('NO')
        mlog.log('Checking for function "', mlog.bold(funcname), '": ', hadtxt, sep='')
        return had

    def has_type_method(self, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('Has_type takes exactly one argument.')
        check_stringlist(args)
        typename = args[0]
        prefix = kwargs.get('prefix', '')
        if not isinstance(prefix, str):
            raise InterpreterException('Prefix argument of has_type must be a string.')
        extra_args = self.determine_args(kwargs)
        deps = self.determine_dependencies(kwargs)
        had = self.compiler.has_type(typename, prefix, self.environment, extra_args, deps)
        if had:
            hadtxt = mlog.green('YES')
        else:
            hadtxt = mlog.red('NO')
        mlog.log('Checking for type "', mlog.bold(typename), '": ', hadtxt, sep='')
        return had

    def sizeof_method(self, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('Sizeof takes exactly one argument.')
        check_stringlist(args)
        element = args[0]
        prefix = kwargs.get('prefix', '')
        if not isinstance(prefix, str):
            raise InterpreterException('Prefix argument of sizeof must be a string.')
        extra_args = self.determine_args(kwargs)
        deps = self.determine_dependencies(kwargs)
        esize = self.compiler.sizeof(element, prefix, self.environment, extra_args, deps)
        mlog.log('Checking for size of "%s": %d' % (element, esize))
        return esize

    def compiles_method(self, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('compiles method takes exactly one argument.')
        code = args[0]
        if isinstance(code, mesonlib.File):
            code = mesonlib.File.from_absolute_file(
                code.rel_to_builddir(self.environment.source_dir))
        elif not isinstance(code, str):
            raise InvalidArguments('Argument must be string or file.')
        testname = kwargs.get('name', '')
        if not isinstance(testname, str):
            raise InterpreterException('Testname argument must be a string.')
        extra_args = self.determine_args(kwargs)
        deps = self.determine_dependencies(kwargs)
        result = self.compiler.compiles(code, self.environment, extra_args, deps)
        if len(testname) > 0:
            if result:
                h = mlog.green('YES')
            else:
                h = mlog.red('NO')
            mlog.log('Checking if "', mlog.bold(testname), '" compiles: ', h, sep='')
        return result

    def links_method(self, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('links method takes exactly one argument.')
        code = args[0]
        if isinstance(code, mesonlib.File):
            code = mesonlib.File.from_absolute_file(
                code.rel_to_builddir(self.environment.source_dir))
        elif not isinstance(code, str):
            raise InvalidArguments('Argument must be string or file.')
        testname = kwargs.get('name', '')
        if not isinstance(testname, str):
            raise InterpreterException('Testname argument must be a string.')
        extra_args = self.determine_args(kwargs)
        deps = self.determine_dependencies(kwargs)
        result = self.compiler.links(code, self.environment, extra_args, deps)
        if len(testname) > 0:
            if result:
                h = mlog.green('YES')
            else:
                h = mlog.red('NO')
            mlog.log('Checking if "', mlog.bold(testname), '" links: ', h, sep='')
        return result

    def has_header_method(self, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('has_header method takes exactly one argument.')
        check_stringlist(args)
        hname = args[0]
        prefix = kwargs.get('prefix', '')
        if not isinstance(prefix, str):
            raise InterpreterException('Prefix argument of has_header must be a string.')
        extra_args = self.determine_args(kwargs)
        deps = self.determine_dependencies(kwargs)
        haz = self.compiler.has_header(hname, prefix, self.environment, extra_args, deps)
        if haz:
            h = mlog.green('YES')
        else:
            h = mlog.red('NO')
        mlog.log('Has header "%s":' % hname, h)
        return haz

    def has_header_symbol_method(self, args, kwargs):
        if len(args) != 2:
            raise InterpreterException('has_header_symbol method takes exactly two arguments.')
        check_stringlist(args)
        hname = args[0]
        symbol = args[1]
        prefix = kwargs.get('prefix', '')
        if not isinstance(prefix, str):
            raise InterpreterException('Prefix argument of has_header_symbol must be a string.')
        extra_args = self.determine_args(kwargs)
        deps = self.determine_dependencies(kwargs)
        haz = self.compiler.has_header_symbol(hname, symbol, prefix, self.environment, extra_args, deps)
        if haz:
            h = mlog.green('YES')
        else:
            h = mlog.red('NO')
        mlog.log('Header <{0}> has symbol "{1}":'.format(hname, symbol), h)
        return haz

    def find_library_method(self, args, kwargs):
        # TODO add dependencies support?
        if len(args) != 1:
            raise InterpreterException('find_library method takes one argument.')
        libname = args[0]
        if not isinstance(libname, str):
            raise InterpreterException('Library name not a string.')
        required = kwargs.get('required', True)
        if not isinstance(required, bool):
            raise InterpreterException('required must be boolean.')
        search_dirs = mesonlib.stringlistify(kwargs.get('dirs', []))
        for i in search_dirs:
            if not os.path.isabs(i):
                raise InvalidCode('Search directory %s is not an absolute path.' % i)
        linkargs = self.compiler.find_library(libname, self.environment, search_dirs)
        if required and not linkargs:
            l = self.compiler.language.capitalize()
            raise InterpreterException('{} library {!r} not found'.format(l, libname))
        # If this is set to None, the library and link arguments are for
        # a C-like compiler. Otherwise, it's for some other language that has
        # a find_library implementation. We do this because it's easier than
        # maintaining a list of languages that can consume C libraries.
        lang = None
        if self.compiler.language == 'vala':
            lang = 'vala'
        lib = dependencies.ExternalLibrary(libname, linkargs, language=lang)
        return ExternalLibraryHolder(lib)

    def has_argument_method(self, args, kwargs):
        args = mesonlib.stringlistify(args)
        if len(args) != 1:
            raise InterpreterException('Has_arg takes exactly one argument.')
        result = self.compiler.has_argument(args[0], self.environment)
        if result:
            h = mlog.green('YES')
        else:
            h = mlog.red('NO')
        mlog.log('Compiler for {} supports argument {}:'.format(self.compiler.language, args[0]), h)
        return result

    def has_multi_arguments_method(self, args, kwargs):
        args = mesonlib.stringlistify(args)
        result = self.compiler.has_multi_arguments(args, self.environment)
        if result:
            h = mlog.green('YES')
        else:
            h = mlog.red('NO')
        mlog.log(
            'Compiler for {} supports arguments {}:'.format(
                self.compiler.language, ' '.join(args)),
            h)
        return result

    def first_supported_argument_method(self, args, kwargs):
        for i in mesonlib.stringlistify(args):
            if self.compiler.has_argument(i, self.environment):
                mlog.log('First supported argument:', mlog.bold(i))
                return [i]
        mlog.log('First supported argument:', mlog.red('None'))
        return []

class ModuleState:
    pass

class ModuleHolder(InterpreterObject):
    def __init__(self, modname, module, interpreter):
        InterpreterObject.__init__(self)
        self.modname = modname
        self.held_object = module
        self.interpreter = interpreter

    def method_call(self, method_name, args, kwargs):
        try:
            fn = getattr(self.held_object, method_name)
        except AttributeError:
            raise InvalidArguments('Module %s does not have method %s.' % (self.modname, method_name))
        if method_name.startswith('_'):
            raise InvalidArguments('Function {!r} in module {!r} is private.'.format(method_name, self.modname))
        # This is not 100% reliable but we can't use hash()
        # because the Build object contains dicts and lists.
        num_targets = len(self.interpreter.build.targets)
        state = ModuleState()
        state.build_to_src = os.path.relpath(self.interpreter.environment.get_source_dir(),
                                             self.interpreter.environment.get_build_dir())
        state.subdir = self.interpreter.subdir
        state.environment = self.interpreter.environment
        state.project_name = self.interpreter.build.project_name
        state.project_version = self.interpreter.build.dep_manifest[self.interpreter.active_projectname]
        state.compilers = self.interpreter.build.compilers
        state.targets = self.interpreter.build.targets
        state.data = self.interpreter.build.data
        state.headers = self.interpreter.build.get_headers()
        state.man = self.interpreter.build.get_man()
        state.global_args = self.interpreter.build.global_args
        state.project_args = self.interpreter.build.projects_args.get(self.interpreter.subproject, {})
        state.build_machine = self.interpreter.builtin['build_machine'].held_object
        state.host_machine = self.interpreter.builtin['host_machine'].held_object
        state.target_machine = self.interpreter.builtin['target_machine'].held_object
        if self.held_object.is_snippet(method_name):
            value = fn(self.interpreter, state, args, kwargs)
            return self.interpreter.holderify(value)
        else:
            value = fn(state, args, kwargs)
            if num_targets != len(self.interpreter.build.targets):
                raise InterpreterException('Extension module altered internal state illegally.')
            return self.interpreter.module_method_callback(value)

class MesonMain(InterpreterObject):
    def __init__(self, build, interpreter):
        InterpreterObject.__init__(self)
        self.build = build
        self.interpreter = interpreter
        self._found_source_scripts = {}
        self.methods.update({'get_compiler': self.get_compiler_method,
                             'is_cross_build': self.is_cross_build_method,
                             'has_exe_wrapper': self.has_exe_wrapper_method,
                             'is_unity': self.is_unity_method,
                             'is_subproject': self.is_subproject_method,
                             'current_source_dir': self.current_source_dir_method,
                             'current_build_dir': self.current_build_dir_method,
                             'source_root': self.source_root_method,
                             'build_root': self.build_root_method,
                             'add_install_script': self.add_install_script_method,
                             'add_postconf_script': self.add_postconf_script_method,
                             'install_dependency_manifest': self.install_dependency_manifest_method,
                             'project_version': self.project_version_method,
                             'version': self.version_method,
                             'project_name': self.project_name_method,
                             'get_cross_property': self.get_cross_property_method,
                             'backend': self.backend_method,
                             })

    def _find_source_script(self, name, args):
        # Prefer scripts in the current source directory
        search_dir = os.path.join(self.interpreter.environment.source_dir,
                                  self.interpreter.subdir)
        key = (name, search_dir)
        if key in self._found_source_scripts:
            found = self._found_source_scripts[key]
        else:
            found = dependencies.ExternalProgram(name, search_dir=search_dir)
            if found:
                self._found_source_scripts[key] = found
            else:
                raise InterpreterException('Script {!r} not found'.format(name))
        return build.RunScript(found.get_command(), args)

    def add_install_script_method(self, args, kwargs):
        if len(args) < 1:
            raise InterpreterException('add_install_script takes one or more arguments')
        check_stringlist(args, 'add_install_script args must be strings')
        script = self._find_source_script(args[0], args[1:])
        self.build.install_scripts.append(script)

    def add_postconf_script_method(self, args, kwargs):
        if len(args) < 1:
            raise InterpreterException('add_postconf_script takes one or more arguments')
        check_stringlist(args, 'add_postconf_script arguments must be strings')
        script = self._find_source_script(args[0], args[1:])
        self.build.postconf_scripts.append(script)

    def current_source_dir_method(self, args, kwargs):
        src = self.interpreter.environment.source_dir
        sub = self.interpreter.subdir
        if sub == '':
            return src
        return os.path.join(src, sub)

    def current_build_dir_method(self, args, kwargs):
        src = self.interpreter.environment.build_dir
        sub = self.interpreter.subdir
        if sub == '':
            return src
        return os.path.join(src, sub)

    def backend_method(self, args, kwargs):
        return self.interpreter.backend.name

    def source_root_method(self, args, kwargs):
        return self.interpreter.environment.source_dir

    def build_root_method(self, args, kwargs):
        return self.interpreter.environment.build_dir

    def has_exe_wrapper_method(self, args, kwargs):
        if self.is_cross_build_method(None, None) and \
           'binaries' in self.build.environment.cross_info.config and \
           self.build.environment.cross_info.need_exe_wrapper():
            exe_wrap = self.build.environment.cross_info.config['binaries'].get('exe_wrapper', None)
            if exe_wrap is None:
                return False
        # We return True when exe_wrap is defined, when it's not needed, and
        # when we're compiling natively. The last two are semantically confusing.
        # Need to revisit this.
        return True

    def is_cross_build_method(self, args, kwargs):
        return self.build.environment.is_cross_build()

    def get_compiler_method(self, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('get_compiler_method must have one and only one argument.')
        cname = args[0]
        native = kwargs.get('native', None)
        if native is None:
            if self.build.environment.is_cross_build():
                native = False
            else:
                native = True
        if not isinstance(native, bool):
            raise InterpreterException('Type of "native" must be a boolean.')
        if native:
            clist = self.build.compilers
        else:
            clist = self.build.cross_compilers
        if cname in clist:
            return CompilerHolder(clist[cname], self.build.environment)
        raise InterpreterException('Tried to access compiler for unspecified language "%s".' % cname)

    def is_unity_method(self, args, kwargs):
        return self.build.environment.coredata.get_builtin_option('unity')

    def is_subproject_method(self, args, kwargs):
        return self.interpreter.is_subproject()

    def install_dependency_manifest_method(self, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('Must specify manifest install file name')
        if not isinstance(args[0], str):
            raise InterpreterException('Argument must be a string.')
        self.build.dep_manifest_name = args[0]

    def project_version_method(self, args, kwargs):
        return self.build.dep_manifest[self.interpreter.active_projectname]['version']

    def version_method(self, args, kwargs):
        return coredata.version

    def project_name_method(self, args, kwargs):
        return self.interpreter.active_projectname

    def get_cross_property_method(self, args, kwargs):
        if len(args) < 1 or len(args) > 2:
            raise InterpreterException('Must have one or two arguments.')
        propname = args[0]
        if not isinstance(propname, str):
            raise InterpreterException('Property name must be string.')
        try:
            props = self.interpreter.environment.cross_info.get_properties()
            return props[propname]
        except Exception:
            if len(args) == 2:
                return args[1]
            raise InterpreterException('Unknown cross property: %s.' % propname)

class Interpreter(InterpreterBase):

    def __init__(self, build, backend, subproject='', subdir='', subproject_dir='subprojects',
                 default_project_options=[]):
        super().__init__(build.environment.get_source_dir(), subdir)
        self.build = build
        self.environment = build.environment
        self.coredata = self.environment.get_coredata()
        self.backend = backend
        self.subproject = subproject
        self.subproject_dir = subproject_dir
        self.option_file = os.path.join(self.source_root, self.subdir, 'meson_options.txt')
        self.load_root_meson_file()
        self.sanity_check_ast()
        self.builtin.update({'meson': MesonMain(build, self)})
        self.generators = []
        self.visited_subdirs = {}
        self.args_frozen = False
        self.subprojects = {}
        self.subproject_stack = []
        self.default_project_options = default_project_options[:] # Passed from the outside, only used in subprojects.
        self.build_func_dict()
        self.parse_project()
        self.builtin['build_machine'] = BuildMachine(self.coredata.compilers)
        if not self.build.environment.is_cross_build():
            self.builtin['host_machine'] = self.builtin['build_machine']
            self.builtin['target_machine'] = self.builtin['build_machine']
        else:
            cross_info = self.build.environment.cross_info
            if cross_info.has_host():
                self.builtin['host_machine'] = CrossMachineInfo(cross_info.config['host_machine'])
            else:
                self.builtin['host_machine'] = self.builtin['build_machine']
            if cross_info.has_target():
                self.builtin['target_machine'] = CrossMachineInfo(cross_info.config['target_machine'])
            else:
                self.builtin['target_machine'] = self.builtin['host_machine']
        self.build_def_files = [os.path.join(self.subdir, environment.build_filename)]

    def build_func_dict(self):
        self.funcs.update({'project': self.func_project,
                           'message': self.func_message,
                           'error': self.func_error,
                           'executable': self.func_executable,
                           'dependency': self.func_dependency,
                           'static_library': self.func_static_lib,
                           'shared_library': self.func_shared_lib,
                           'shared_module': self.func_shared_module,
                           'library': self.func_library,
                           'jar': self.func_jar,
                           'build_target': self.func_build_target,
                           'custom_target': self.func_custom_target,
                           'run_target': self.func_run_target,
                           'generator': self.func_generator,
                           'test': self.func_test,
                           'benchmark': self.func_benchmark,
                           'install_headers': self.func_install_headers,
                           'install_man': self.func_install_man,
                           'subdir': self.func_subdir,
                           'install_data': self.func_install_data,
                           'install_subdir': self.func_install_subdir,
                           'configure_file': self.func_configure_file,
                           'include_directories': self.func_include_directories,
                           'add_global_arguments': self.func_add_global_arguments,
                           'add_project_arguments': self.func_add_project_arguments,
                           'add_global_link_arguments': self.func_add_global_link_arguments,
                           'add_project_link_arguments': self.func_add_project_link_arguments,
                           'add_test_setup': self.func_add_test_setup,
                           'add_languages': self.func_add_languages,
                           'find_program': self.func_find_program,
                           'find_library': self.func_find_library,
                           'configuration_data': self.func_configuration_data,
                           'run_command': self.func_run_command,
                           'gettext': self.func_gettext,
                           'option': self.func_option,
                           'get_option': self.func_get_option,
                           'subproject': self.func_subproject,
                           'vcs_tag': self.func_vcs_tag,
                           'set_variable': self.func_set_variable,
                           'is_variable': self.func_is_variable,
                           'get_variable': self.func_get_variable,
                           'import': self.func_import,
                           'files': self.func_files,
                           'declare_dependency': self.func_declare_dependency,
                           'assert': self.func_assert,
                           'environment': self.func_environment,
                           'join_paths': self.func_join_paths,
                           })

    def holderify(self, item):
        if isinstance(item, list):
            return [self.holderify(x) for x in item]
        if isinstance(item, build.CustomTarget):
            return CustomTargetHolder(item, self)
        elif isinstance(item, (int, str)) or item is None:
            return item
        elif isinstance(item, build.Executable):
            return ExecutableHolder(item, self)
        elif isinstance(item, build.GeneratedList):
            return GeneratedListHolder(item)
        elif isinstance(item, build.RunTarget):
            raise RuntimeError('This is not a pipe.')
        elif isinstance(item, build.RunScript):
            raise RuntimeError('Do not do this.')
        elif isinstance(item, build.Data):
            return DataHolder(item)
        elif isinstance(item, dependencies.InternalDependency):
            return InternalDependencyHolder(item)
        elif isinstance(item, dependencies.ExternalProgram):
            return ExternalProgramHolder(item)
        elif hasattr(item, 'held_object'):
            return item
        else:
            raise InterpreterException('Module returned a value of unknown type.')

    def process_new_values(self, invalues):
        if not isinstance(invalues, list):
            invalues = [invalues]
        for v in invalues:
            if isinstance(v, (build.BuildTarget, build.CustomTarget, build.RunTarget)):
                self.add_target(v.name, v)
            elif isinstance(v, list):
                self.module_method_callback(v)
            elif isinstance(v, build.GeneratedList):
                pass
            elif isinstance(v, build.RunScript):
                self.build.install_scripts.append(v)
            elif isinstance(v, build.Data):
                self.build.data.append(v)
            elif isinstance(v, dependencies.ExternalProgram):
                return ExternalProgramHolder(v)
            elif isinstance(v, dependencies.InternalDependency):
                # FIXME: This is special cased and not ideal:
                # The first source is our new VapiTarget, the rest are deps
                self.process_new_values(v.sources[0])
            elif hasattr(v, 'held_object'):
                pass
            else:
                raise InterpreterException('Module returned a value of unknown type.')

    def module_method_callback(self, return_object):
        if not isinstance(return_object, ModuleReturnValue):
            assert False
            raise InterpreterException('Bug in module, it returned an invalid object')
        invalues = return_object.new_objects
        self.process_new_values(invalues)
        return self.holderify(return_object.return_value)

    def get_build_def_files(self):
        return self.build_def_files

    def get_variables(self):
        return self.variables

    def check_cross_stdlibs(self):
        if self.build.environment.is_cross_build():
            cross_info = self.build.environment.cross_info
            for l, c in self.build.cross_compilers.items():
                try:
                    di = mesonlib.stringlistify(cross_info.get_stdlib(l))
                    if len(di) != 2:
                        raise InterpreterException('Stdlib definition for %s should have exactly two elements.'
                                                   % l)
                    projname, depname = di
                    subproj = self.do_subproject(projname, {})
                    self.build.cross_stdlibs[l] = subproj.get_variable_method([depname], {})
                except KeyError:
                    pass

    @stringArgs
    @noKwargs
    def func_import(self, node, args, kwargs):
        if len(args) != 1:
            raise InvalidCode('Import takes one argument.')
        modname = args[0]
        if modname not in self.environment.coredata.modules:
            module = importlib.import_module('mesonbuild.modules.' + modname).initialize()
            self.environment.coredata.modules[modname] = module
        return ModuleHolder(modname, self.environment.coredata.modules[modname], self)

    @stringArgs
    @noKwargs
    def func_files(self, node, args, kwargs):
        return [mesonlib.File.from_source_file(self.environment.source_dir, self.subdir, fname) for fname in args]

    @noPosargs
    def func_declare_dependency(self, node, args, kwargs):
        version = kwargs.get('version', self.project_version)
        if not isinstance(version, str):
            raise InterpreterException('Version must be a string.')
        incs = kwargs.get('include_directories', [])
        if not isinstance(incs, list):
            incs = [incs]
        libs = kwargs.get('link_with', [])
        if not isinstance(libs, list):
            libs = [libs]
        sources = kwargs.get('sources', [])
        if not isinstance(sources, list):
            sources = [sources]
        sources = self.source_strings_to_files(self.flatten(sources))
        deps = kwargs.get('dependencies', [])
        if not isinstance(deps, list):
            deps = [deps]
        compile_args = mesonlib.stringlistify(kwargs.get('compile_args', []))
        link_args = mesonlib.stringlistify(kwargs.get('link_args', []))
        final_deps = []
        for d in deps:
            try:
                d = d.held_object
            except Exception:
                pass
            if not isinstance(d, (dependencies.Dependency, dependencies.ExternalLibrary, dependencies.InternalDependency)):
                raise InterpreterException('Dependencies must be external deps')
            final_deps.append(d)
        dep = dependencies.InternalDependency(version, incs, compile_args, link_args, libs, sources, final_deps)
        return DependencyHolder(dep)

    @noKwargs
    def func_assert(self, node, args, kwargs):
        if len(args) != 2:
            raise InterpreterException('Assert takes exactly two arguments')
        value, message = args
        if not isinstance(value, bool):
            raise InterpreterException('Assert value not bool.')
        if not isinstance(message, str):
            raise InterpreterException('Assert message not a string.')
        if not value:
            raise InterpreterException('Assert failed: ' + message)

    def validate_arguments(self, args, argcount, arg_types):
        if argcount is not None:
            if argcount != len(args):
                raise InvalidArguments('Expected %d arguments, got %d.' %
                                       (argcount, len(args)))
        for i in range(min(len(args), len(arg_types))):
            wanted = arg_types[i]
            actual = args[i]
            if wanted is not None:
                if not isinstance(actual, wanted):
                    raise InvalidArguments('Incorrect argument type.')

    def func_run_command(self, node, args, kwargs):
        if len(args) < 1:
            raise InterpreterException('Not enough arguments')
        cmd = args[0]
        cargs = args[1:]
        if isinstance(cmd, ExternalProgramHolder):
            cmd = cmd.get_command()
        elif isinstance(cmd, str):
            cmd = [cmd]
        else:
            raise InterpreterException('First argument is of incorrect type.')
        expanded_args = []
        for a in mesonlib.flatten(cargs):
            if isinstance(a, str):
                expanded_args.append(a)
            elif isinstance(a, mesonlib.File):
                if a.is_built:
                    raise InterpreterException('Can not use generated files in run_command.')
                expanded_args.append(os.path.join(self.environment.get_source_dir(), str(a)))
            else:
                raise InterpreterException('Run_command arguments must be strings or the output of files().')
        args = cmd + expanded_args
        in_builddir = kwargs.get('in_builddir', False)
        if not isinstance(in_builddir, bool):
            raise InterpreterException('in_builddir must be boolean.')
        return RunProcess(args, self.environment.source_dir, self.environment.build_dir,
                          self.subdir, in_builddir)

    @stringArgs
    def func_gettext(self, nodes, args, kwargs):
        raise InterpreterException('Gettext() function has been moved to module i18n. Import it and use i18n.gettext() instead')

    def func_option(self, nodes, args, kwargs):
        raise InterpreterException('Tried to call option() in build description file. All options must be in the option file.')

    @stringArgs
    def func_subproject(self, nodes, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('Subproject takes exactly one argument')
        dirname = args[0]
        return self.do_subproject(dirname, kwargs)

    def do_subproject(self, dirname, kwargs):
        if dirname in self.subproject_stack:
            fullstack = self.subproject_stack + [dirname]
            incpath = ' => '.join(fullstack)
            raise InvalidCode('Recursive include of subprojects: %s.' % incpath)
        if dirname in self.subprojects:
            return self.subprojects[dirname]
        r = wrap.Resolver(os.path.join(self.build.environment.get_source_dir(), self.subproject_dir))
        resolved = r.resolve(dirname)
        if resolved is None:
            msg = 'Subproject directory {!r} does not exist and cannot be downloaded.'
            raise InterpreterException(msg.format(os.path.join(self.subproject_dir, dirname)))
        subdir = os.path.join(self.subproject_dir, resolved)
        os.makedirs(os.path.join(self.build.environment.get_build_dir(), subdir), exist_ok=True)
        self.args_frozen = True
        mlog.log('\nExecuting subproject ', mlog.bold(dirname), '.\n', sep='')
        subi = Interpreter(self.build, self.backend, dirname, subdir, self.subproject_dir,
                           mesonlib.stringlistify(kwargs.get('default_options', [])))
        subi.subprojects = self.subprojects

        subi.subproject_stack = self.subproject_stack + [dirname]
        current_active = self.active_projectname
        subi.run()
        if 'version' in kwargs:
            pv = subi.project_version
            wanted = kwargs['version']
            if pv == 'undefined' or not mesonlib.version_compare(pv, wanted):
                raise InterpreterException('Subproject %s version is %s but %s required.' % (dirname, pv, wanted))
        self.active_projectname = current_active
        mlog.log('\nSubproject', mlog.bold(dirname), 'finished.')
        self.build.subprojects[dirname] = subi.project_version
        self.subprojects.update(subi.subprojects)
        self.subprojects[dirname] = SubprojectHolder(subi)
        self.build_def_files += subi.build_def_files
        return self.subprojects[dirname]

    @stringArgs
    @noKwargs
    def func_get_option(self, nodes, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('Argument required for get_option.')
        optname = args[0]
        try:
            return self.environment.get_coredata().get_builtin_option(optname)
        except RuntimeError:
            pass
        try:
            return self.environment.coredata.compiler_options[optname].value
        except KeyError:
            pass
        if not coredata.is_builtin_option(optname) and self.is_subproject():
            optname = self.subproject + ':' + optname
        try:
            return self.environment.coredata.user_options[optname].value
        except KeyError:
            pass
        if optname.endswith('_link_args'):
            try:
                lang = optname[:-10]
                return self.coredata.external_link_args[lang]
            except KeyError:
                pass
        if optname.endswith('_args'):
            try:
                lang = optname[:-5]
                return self.coredata.external_args[lang]
            except KeyError:
                pass
        raise InterpreterException('Tried to access unknown option "%s".' % optname)

    @noKwargs
    def func_configuration_data(self, node, args, kwargs):
        if len(args) != 0:
            raise InterpreterException('configuration_data takes no arguments')
        return ConfigurationDataHolder()

    def parse_default_options(self, default_options):
        if not isinstance(default_options, list):
            default_options = [default_options]
        for option in default_options:
            if not isinstance(option, str):
                mlog.debug(option)
                raise InterpreterException('Default options must be strings')
            if '=' not in option:
                raise InterpreterException('All default options must be of type key=value.')
            key, value = option.split('=', 1)
            if coredata.is_builtin_option(key):
                if self.subproject != '':
                    continue # Only the master project is allowed to set global options.
                if not self.environment.had_argument_for(key):
                    self.coredata.set_builtin_option(key, value)
                # If this was set on the command line, do not override.
            else:
                # Option values set with subproject() default_options override those
                # set in project() default_options.
                pref = key + '='
                for i in self.default_project_options:
                    if i.startswith(pref):
                        option = i
                        break
                # If we are in a subproject, add the subproject prefix to option
                # name.
                if self.subproject != '':
                    option = self.subproject + ':' + option
                newoptions = [option] + self.environment.cmd_line_options.projectoptions
                self.environment.cmd_line_options.projectoptions = newoptions
        # Add options that are only in default_options.
        for defopt in self.default_project_options:
            key, value = defopt.split('=')
            pref = key + '='
            for i in default_options:
                if i.startswith(pref):
                    break
            else:
                defopt = self.subproject + ':' + defopt
                newoptions = [defopt] + self.environment.cmd_line_options.projectoptions
                self.environment.cmd_line_options.projectoptions = newoptions

    @stringArgs
    def func_project(self, node, args, kwargs):
        if self.environment.first_invocation and ('default_options' in kwargs or
                                                  len(self.default_project_options) > 0):
            self.parse_default_options(kwargs['default_options'])
        if not self.is_subproject():
            self.build.project_name = args[0]
        if os.path.exists(self.option_file):
            oi = optinterpreter.OptionInterpreter(self.subproject,
                                                  self.build.environment.cmd_line_options.projectoptions,
                                                  )
            oi.process(self.option_file)
            self.build.environment.merge_options(oi.options)
        if len(args) < 2:
            raise InvalidArguments('Not enough arguments to project(). Needs at least the project name and one language')
        self.active_projectname = args[0]
        self.project_version = kwargs.get('version', 'undefined')
        if self.build.project_version is None:
            self.build.project_version = self.project_version
        proj_license = mesonlib.stringlistify(kwargs.get('license', 'unknown'))
        self.build.dep_manifest[args[0]] = {'version': self.project_version,
                                            'license': proj_license}
        if self.subproject in self.build.projects:
            raise InvalidCode('Second call to project().')
        if not self.is_subproject() and 'subproject_dir' in kwargs:
            self.subproject_dir = kwargs['subproject_dir']

        if 'meson_version' in kwargs:
            cv = coredata.version
            pv = kwargs['meson_version']
            if not mesonlib.version_compare(cv, pv):
                raise InterpreterException('Meson version is %s but project requires %s.' % (cv, pv))
        self.build.projects[self.subproject] = args[0]
        mlog.log('Project name: ', mlog.bold(args[0]), sep='')
        self.add_languages(args[1:], True)
        langs = self.coredata.compilers.keys()
        if 'vala' in langs:
            if 'c' not in langs:
                raise InterpreterException('Compiling Vala requires C. Add C to your project languages and rerun Meson.')
        if not self.is_subproject():
            self.check_cross_stdlibs()

    @stringArgs
    def func_add_languages(self, node, args, kwargs):
        return self.add_languages(args, kwargs.get('required', True))

    @noKwargs
    def func_message(self, node, args, kwargs):
        # reduce arguments again to avoid flattening posargs
        (posargs, _) = self.reduce_arguments(node.args)
        if len(posargs) != 1:
            raise InvalidArguments('Expected 1 argument, got %d' % len(posargs))

        arg = posargs[0]
        if isinstance(arg, list):
            argstr = stringifyUserArguments(arg)
        elif isinstance(arg, str):
            argstr = arg
        elif isinstance(arg, int):
            argstr = str(arg)
        else:
            raise InvalidArguments('Function accepts only strings, integers, lists and lists thereof.')

        mlog.log(mlog.bold('Message:'), argstr)

    @noKwargs
    def func_error(self, node, args, kwargs):
        self.validate_arguments(args, 1, [str])
        raise InterpreterException('Error encountered: ' + args[0])

    def detect_compilers(self, lang, need_cross_compiler):
        cross_comp = None
        if lang == 'c':
            comp = self.environment.detect_c_compiler(False)
            if need_cross_compiler:
                cross_comp = self.environment.detect_c_compiler(True)
        elif lang == 'cpp':
            comp = self.environment.detect_cpp_compiler(False)
            if need_cross_compiler:
                cross_comp = self.environment.detect_cpp_compiler(True)
        elif lang == 'objc':
            comp = self.environment.detect_objc_compiler(False)
            if need_cross_compiler:
                cross_comp = self.environment.detect_objc_compiler(True)
        elif lang == 'objcpp':
            comp = self.environment.detect_objcpp_compiler(False)
            if need_cross_compiler:
                cross_comp = self.environment.detect_objcpp_compiler(True)
        elif lang == 'java':
            comp = self.environment.detect_java_compiler()
            if need_cross_compiler:
                cross_comp = comp  # Java is platform independent.
        elif lang == 'cs':
            comp = self.environment.detect_cs_compiler()
            if need_cross_compiler:
                cross_comp = comp  # C# is platform independent.
        elif lang == 'vala':
            comp = self.environment.detect_vala_compiler()
            if need_cross_compiler:
                cross_comp = comp  # Vala compiles to platform-independent C
        elif lang == 'd':
            comp = self.environment.detect_d_compiler(False)
            if need_cross_compiler:
                cross_comp = self.environment.detect_d_compiler(True)
        elif lang == 'rust':
            comp = self.environment.detect_rust_compiler()
            if need_cross_compiler:
                cross_comp = comp  # FIXME, not correct.
        elif lang == 'fortran':
            comp = self.environment.detect_fortran_compiler(False)
            if need_cross_compiler:
                cross_comp = self.environment.detect_fortran_compiler(True)
        elif lang == 'swift':
            comp = self.environment.detect_swift_compiler()
            if need_cross_compiler:
                raise InterpreterException('Cross compilation with Swift is not working yet.')
                # cross_comp = self.environment.detect_fortran_compiler(True)
        else:
            raise InvalidCode('Tried to use unknown language "%s".' % lang)
        comp.sanity_check(self.environment.get_scratch_dir(), self.environment)
        self.coredata.compilers[lang] = comp
        # Native compiler always exist so always add its options.
        new_options = comp.get_options()
        if cross_comp is not None:
            cross_comp.sanity_check(self.environment.get_scratch_dir(), self.environment)
            self.coredata.cross_compilers[lang] = cross_comp
            new_options.update(cross_comp.get_options())
        optprefix = lang + '_'
        for i in new_options:
            if not i.startswith(optprefix):
                raise InterpreterException('Internal error, %s has incorrect prefix.' % i)
            cmd_prefix = i + '='
            for cmd_arg in self.environment.cmd_line_options.projectoptions:
                if cmd_arg.startswith(cmd_prefix):
                    value = cmd_arg.split('=', 1)[1]
                    new_options[i].set_value(value)
        new_options.update(self.coredata.compiler_options)
        self.coredata.compiler_options = new_options
        return comp, cross_comp

    def add_languages(self, args, required):
        success = True
        need_cross_compiler = self.environment.is_cross_build() and self.environment.cross_info.need_cross_compiler()
        for lang in args:
            lang = lang.lower()
            if lang in self.coredata.compilers:
                comp = self.coredata.compilers[lang]
                cross_comp = self.coredata.cross_compilers.get(lang, None)
            else:
                try:
                    (comp, cross_comp) = self.detect_compilers(lang, need_cross_compiler)
                except Exception:
                    if not required:
                        mlog.log('Compiler for language', mlog.bold(lang), 'not found.')
                        success = False
                        continue
                    else:
                        raise
            mlog.log('Native %s compiler: ' % lang, mlog.bold(' '.join(comp.get_exelist())), ' (%s %s)' % (comp.id, comp.version), sep='')
            if not comp.get_language() in self.coredata.external_args:
                (ext_compile_args, ext_link_args) = environment.get_args_from_envvars(comp)
                self.coredata.external_args[comp.get_language()] = ext_compile_args
                self.coredata.external_link_args[comp.get_language()] = ext_link_args
            self.build.add_compiler(comp)
            if need_cross_compiler:
                mlog.log('Cross %s compiler: ' % lang, mlog.bold(' '.join(cross_comp.get_exelist())), ' (%s %s)' % (cross_comp.id, cross_comp.version), sep='')
                self.build.add_cross_compiler(cross_comp)
            if self.environment.is_cross_build() and not need_cross_compiler:
                self.build.add_cross_compiler(comp)
            self.add_base_options(comp)
        return success

    def add_base_options(self, compiler):
        proj_opt = self.environment.cmd_line_options.projectoptions
        for optname in compiler.base_options:
            if optname in self.coredata.base_options:
                continue
            oobj = compilers.base_options[optname]
            for po in proj_opt:
                if po.startswith(optname + '='):
                    oobj.set_value(po.split('=', 1)[1])
                    break
            self.coredata.base_options[optname] = oobj

    @stringArgs
    def func_find_program(self, node, args, kwargs):
        if len(args) == 0:
            raise InterpreterException('No program name specified.')
        required = kwargs.get('required', True)
        if not isinstance(required, bool):
            raise InvalidArguments('"required" argument must be a boolean.')
        # Search for scripts relative to current subdir.
        # Do not cache found programs because find_program('foobar')
        # might give different results when run from different source dirs.
        search_dir = os.path.join(self.environment.get_source_dir(), self.subdir)
        for exename in args:
            extprog = dependencies.ExternalProgram(exename, search_dir=search_dir)
            progobj = ExternalProgramHolder(extprog)
            if progobj.found():
                return progobj
        if required and not progobj.found():
            raise InvalidArguments('Program "%s" not found.' % exename)
        return progobj

    def func_find_library(self, node, args, kwargs):
        mlog.log(mlog.red('DEPRECATION:'), 'find_library() is removed, use the corresponding method in compiler object instead.')

    def func_dependency(self, node, args, kwargs):
        self.validate_arguments(args, 1, [str])
        name = args[0]
        if '<' in name or '>' in name or '=' in name:
            raise InvalidArguments('''Characters <, > and = are forbidden in target names. To specify version
requirements use the version keyword argument instead.''')
        identifier = dependencies.get_dep_identifier(name, kwargs)
        # Check if we've already searched for and found this dep
        cached_dep = None
        if identifier in self.coredata.deps:
            cached_dep = self.coredata.deps[identifier]
            if 'version' in kwargs:
                wanted = kwargs['version']
                found = cached_dep.get_version()
                if not cached_dep.found() or \
                   not mesonlib.version_compare_many(found, wanted)[0]:
                    # Cached dep has the wrong version. Check if an external
                    # dependency or a fallback dependency provides it.
                    cached_dep = None
            # Don't re-use cached dep if it wasn't required but this one is,
            # so we properly go into fallback/error code paths
            if kwargs.get('required', True) and not getattr(cached_dep, 'required', False):
                cached_dep = None

        if cached_dep:
            dep = cached_dep
        else:
            # We need to actually search for this dep
            exception = None
            dep = None
            # If the fallback has already been configured (possibly by a higher level project)
            # try to use it before using the native version
            if 'fallback' in kwargs:
                dirname, varname = self.get_subproject_infos(kwargs)
                if dirname in self.subprojects:
                    try:
                        dep = self.subprojects[dirname].get_variable_method([varname], {})
                        dep = dep.held_object
                    except KeyError:
                        pass

            if not dep:
                try:
                    dep = dependencies.find_external_dependency(name, self.environment, kwargs)
                except dependencies.DependencyException as e:
                    exception = e
                    pass

            if not dep or not dep.found():
                if 'fallback' in kwargs:
                    fallback_dep = self.dependency_fallback(name, kwargs)
                    if fallback_dep:
                        return fallback_dep

                if not dep:
                    raise exception

        self.coredata.deps[identifier] = dep
        return DependencyHolder(dep)

    def get_subproject_infos(self, kwargs):
        fbinfo = kwargs['fallback']
        check_stringlist(fbinfo)
        if len(fbinfo) != 2:
            raise InterpreterException('Fallback info must have exactly two items.')
        return fbinfo

    def dependency_fallback(self, name, kwargs):
        dirname, varname = self.get_subproject_infos(kwargs)
        # Try to execute the subproject
        try:
            sp_kwargs = {}
            try:
                sp_kwargs['default_options'] = kwargs['default_options']
            except KeyError:
                pass
            self.do_subproject(dirname, sp_kwargs)
        # Invalid code is always an error
        except InvalidCode:
            raise
        # If the subproject execution failed in a non-fatal way, don't raise an
        # exception; let the caller handle things.
        except:
            mlog.log('Also couldn\'t find a fallback subproject in',
                     mlog.bold(os.path.join(self.subproject_dir, dirname)),
                     'for the dependency', mlog.bold(name))
            return None
        try:
            dep = self.subprojects[dirname].get_variable_method([varname], {})
        except KeyError:
            raise InvalidCode('Fallback variable {!r} in the subproject '
                              '{!r} does not exist'.format(varname, dirname))
        if not isinstance(dep, DependencyHolder):
            raise InvalidCode('Fallback variable {!r} in the subproject {!r} is '
                              'not a dependency object.'.format(varname, dirname))
        # Check if the version of the declared dependency matches what we want
        if 'version' in kwargs:
            wanted = kwargs['version']
            found = dep.version_method([], {})
            if found == 'undefined' or not mesonlib.version_compare(found, wanted):
                mlog.log('Subproject', mlog.bold(dirname), 'dependency',
                         mlog.bold(varname), 'version is', mlog.bold(found),
                         'but', mlog.bold(wanted), 'is required.')
                return None
        mlog.log('Found a', mlog.green('fallback'), 'subproject',
                 mlog.bold(os.path.join(self.subproject_dir, dirname)), 'for',
                 mlog.bold(name))
        return dep

    def func_executable(self, node, args, kwargs):
        return self.build_target(node, args, kwargs, ExecutableHolder)

    def func_static_lib(self, node, args, kwargs):
        return self.build_target(node, args, kwargs, StaticLibraryHolder)

    def func_shared_lib(self, node, args, kwargs):
        return self.build_target(node, args, kwargs, SharedLibraryHolder)

    def func_shared_module(self, node, args, kwargs):
        return self.build_target(node, args, kwargs, SharedModuleHolder)

    def func_library(self, node, args, kwargs):
        if self.coredata.get_builtin_option('default_library') == 'shared':
            return self.func_shared_lib(node, args, kwargs)
        return self.func_static_lib(node, args, kwargs)

    def func_jar(self, node, args, kwargs):
        return self.build_target(node, args, kwargs, JarHolder)

    def func_build_target(self, node, args, kwargs):
        if 'target_type' not in kwargs:
            raise InterpreterException('Missing target_type keyword argument')
        target_type = kwargs.pop('target_type')
        if target_type == 'executable':
            return self.func_executable(node, args, kwargs)
        elif target_type == 'shared_library':
            return self.func_shared_lib(node, args, kwargs)
        elif target_type == 'static_library':
            return self.func_static_lib(node, args, kwargs)
        elif target_type == 'library':
            return self.func_library(node, args, kwargs)
        elif target_type == 'jar':
            return self.func_jar(node, args, kwargs)
        else:
            raise InterpreterException('Unknown target_type.')

    def func_vcs_tag(self, node, args, kwargs):
        fallback = kwargs.pop('fallback', None)
        if not isinstance(fallback, str):
            raise InterpreterException('Keyword argument fallback must exist and be a string.')
        replace_string = kwargs.pop('replace_string', '@VCS_TAG@')
        regex_selector = '(.*)' # default regex selector for custom command: use complete output
        vcs_cmd = kwargs.get('command', None)
        if vcs_cmd and not isinstance(vcs_cmd, list):
            vcs_cmd = [vcs_cmd]
        source_dir = os.path.normpath(os.path.join(self.environment.get_source_dir(), self.subdir))
        if vcs_cmd:
            # Is the command an executable in path or maybe a script in the source tree?
            vcs_cmd[0] = shutil.which(vcs_cmd[0]) or os.path.join(source_dir, vcs_cmd[0])
        else:
            vcs = mesonlib.detect_vcs(source_dir)
            if vcs:
                mlog.log('Found %s repository at %s' % (vcs['name'], vcs['wc_dir']))
                vcs_cmd = vcs['get_rev'].split()
                regex_selector = vcs['rev_regex']
            else:
                vcs_cmd = [' '] # executing this cmd will fail in vcstagger.py and force to use the fallback string
        # vcstagger.py parameters: infile, outfile, fallback, source_dir, replace_string, regex_selector, command...
        kwargs['command'] = [sys.executable,
                             self.environment.get_build_command(),
                             '--internal',
                             'vcstagger',
                             '@INPUT0@',
                             '@OUTPUT0@',
                             fallback,
                             source_dir,
                             replace_string,
                             regex_selector] + vcs_cmd
        kwargs.setdefault('build_always', True)
        return self.func_custom_target(node, [kwargs['output']], kwargs)

    @stringArgs
    def func_custom_target(self, node, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('custom_target: Only one positional argument is allowed, and it must be a string name')
        name = args[0]
        tg = CustomTargetHolder(build.CustomTarget(name, self.subdir, kwargs), self)
        self.add_target(name, tg.held_object)
        return tg

    def func_run_target(self, node, args, kwargs):
        global run_depr_printed
        if len(args) > 1:
            if not run_depr_printed:
                mlog.log(mlog.red('DEPRECATION'), 'positional version of run_target is deprecated, use the keyword version instead.')
                run_depr_printed = True
            if 'command' in kwargs:
                raise InterpreterException('Can not have command both in positional and keyword arguments.')
            all_args = args[1:]
            deps = []
        elif len(args) == 1:
            if 'command' not in kwargs:
                raise InterpreterException('Missing "command" keyword argument')
            all_args = kwargs['command']
            if not isinstance(all_args, list):
                all_args = [all_args]
            deps = kwargs.get('depends', [])
            if not isinstance(deps, list):
                deps = [deps]
        else:
            raise InterpreterException('Run_target needs at least one positional argument.')

        cleaned_args = []
        for i in mesonlib.flatten(all_args):
            try:
                i = i.held_object
            except AttributeError:
                pass
            if not isinstance(i, (str, build.BuildTarget, build.CustomTarget, dependencies.ExternalProgram, mesonlib.File)):
                mlog.debug('Wrong type:', str(i))
                raise InterpreterException('Invalid argument to run_target.')
            cleaned_args.append(i)
        name = args[0]
        if not isinstance(name, str):
            raise InterpreterException('First argument must be a string.')
        cleaned_deps = []
        for d in deps:
            try:
                d = d.held_object
            except AttributeError:
                pass
            if not isinstance(d, (build.BuildTarget, build.CustomTarget)):
                raise InterpreterException('Depends items must be build targets.')
            cleaned_deps.append(d)
        command = cleaned_args[0]
        cmd_args = cleaned_args[1:]
        tg = RunTargetHolder(name, command, cmd_args, cleaned_deps, self.subdir)
        self.add_target(name, tg.held_object)
        return tg

    def func_generator(self, node, args, kwargs):
        gen = GeneratorHolder(self, args, kwargs)
        self.generators.append(gen)
        return gen

    def func_benchmark(self, node, args, kwargs):
        self.add_test(node, args, kwargs, False)

    def func_test(self, node, args, kwargs):
        self.add_test(node, args, kwargs, True)

    def unpack_env_kwarg(self, kwargs):
        envlist = kwargs.get('env', [])
        if isinstance(envlist, EnvironmentVariablesHolder):
            env = envlist.held_object
        else:
            if not isinstance(envlist, list):
                envlist = [envlist]
            env = {}
            for e in envlist:
                if '=' not in e:
                    raise InterpreterException('Env var definition must be of type key=val.')
                (k, val) = e.split('=', 1)
                k = k.strip()
                val = val.strip()
                if ' ' in k:
                    raise InterpreterException('Env var key must not have spaces in it.')
                env[k] = val
        return env

    def add_test(self, node, args, kwargs, is_base_test):
        if len(args) != 2:
            raise InterpreterException('Incorrect number of arguments')
        if not isinstance(args[0], str):
            raise InterpreterException('First argument of test must be a string.')
        if not isinstance(args[1], (ExecutableHolder, JarHolder, ExternalProgramHolder)):
            raise InterpreterException('Second argument must be executable.')
        par = kwargs.get('is_parallel', True)
        if not isinstance(par, bool):
            raise InterpreterException('Keyword argument is_parallel must be a boolean.')
        cmd_args = kwargs.get('args', [])
        if not isinstance(cmd_args, list):
            cmd_args = [cmd_args]
        for i in cmd_args:
            if not isinstance(i, (str, mesonlib.File, TargetHolder)):
                raise InterpreterException('Command line arguments must be strings, files or targets.')
        env = self.unpack_env_kwarg(kwargs)
        should_fail = kwargs.get('should_fail', False)
        if not isinstance(should_fail, bool):
            raise InterpreterException('Keyword argument should_fail must be a boolean.')
        timeout = kwargs.get('timeout', 30)
        if 'workdir' in kwargs:
            workdir = kwargs['workdir']
            if not isinstance(workdir, str):
                raise InterpreterException('Workdir keyword argument must be a string.')
            if not os.path.isabs(workdir):
                raise InterpreterException('Workdir keyword argument must be an absolute path.')
        else:
            workdir = None
        if not isinstance(timeout, int):
            raise InterpreterException('Timeout must be an integer.')
        suite = []
        for s in mesonlib.stringlistify(kwargs.get('suite', '')):
            if len(s) > 0:
                s = ':' + s
            if self.is_subproject():
                suite.append(self.subproject.replace(' ', '_').replace(':', '_') + s)
            else:
                suite.append(self.build.project_name.replace(' ', '_').replace(':', '_') + s)
        t = Test(args[0], suite, args[1].held_object, par, cmd_args, env, should_fail, timeout, workdir)
        if is_base_test:
            self.build.tests.append(t)
            mlog.debug('Adding test "', mlog.bold(args[0]), '".', sep='')
        else:
            self.build.benchmarks.append(t)
            mlog.debug('Adding benchmark "', mlog.bold(args[0]), '".', sep='')

    def func_install_headers(self, node, args, kwargs):
        source_files = self.source_strings_to_files(args)
        h = Headers(source_files, kwargs)
        self.build.headers.append(h)
        return h

    @stringArgs
    def func_install_man(self, node, args, kwargs):
        m = Man(self.subdir, args, kwargs)
        self.build.man.append(m)
        return m

    @noKwargs
    def func_subdir(self, node, args, kwargs):
        self.validate_arguments(args, 1, [str])
        if '..' in args[0]:
            raise InvalidArguments('Subdir contains ..')
        if self.subdir == '' and args[0] == self.subproject_dir:
            raise InvalidArguments('Must not go into subprojects dir with subdir(), use subproject() instead.')
        prev_subdir = self.subdir
        subdir = os.path.join(prev_subdir, args[0])
        if subdir in self.visited_subdirs:
            raise InvalidArguments('Tried to enter directory "%s", which has already been visited.'
                                   % subdir)
        self.visited_subdirs[subdir] = True
        self.subdir = subdir
        os.makedirs(os.path.join(self.environment.build_dir, subdir), exist_ok=True)
        buildfilename = os.path.join(self.subdir, environment.build_filename)
        self.build_def_files.append(buildfilename)
        absname = os.path.join(self.environment.get_source_dir(), buildfilename)
        if not os.path.isfile(absname):
            self.subdir = prev_subdir
            raise InterpreterException('Nonexistent build def file %s.' % buildfilename)
        with open(absname, encoding='utf8') as f:
            code = f.read()
        assert(isinstance(code, str))
        try:
            codeblock = mparser.Parser(code, self.subdir).parse()
        except mesonlib.MesonException as me:
            me.file = buildfilename
            raise me
        self.evaluate_codeblock(codeblock)
        self.subdir = prev_subdir

    def _get_kwarg_install_mode(self, kwargs):
        if 'install_mode' not in kwargs:
            return None
        install_mode = []
        mode = mesonlib.stringintlistify(kwargs.get('install_mode', []))
        for m in mode:
            # We skip any arguments that are set to `false`
            if m is False:
                m = None
            install_mode.append(m)
        if len(install_mode) > 3:
            raise InvalidArguments('Keyword argument install_mode takes at '
                                   'most 3 arguments.')
        if len(install_mode) > 0 and install_mode[0] is not None and \
           not isinstance(install_mode[0], str):
            raise InvalidArguments('Keyword argument install_mode requires the '
                                   'permissions arg to be a string or false')
        return FileMode(*install_mode)

    def func_install_data(self, node, args, kwargs):
        kwsource = mesonlib.stringlistify(kwargs.get('sources', []))
        raw_sources = args + kwsource
        sources = []
        source_strings = []
        for s in raw_sources:
            if isinstance(s, mesonlib.File):
                sources.append(s)
            else:
                source_strings.append(s)
        sources += self.source_strings_to_files(source_strings)
        install_dir = kwargs.get('install_dir', None)
        if not isinstance(install_dir, (str, type(None))):
            raise InvalidArguments('Keyword argument install_dir not a string.')
        install_mode = self._get_kwarg_install_mode(kwargs)
        data = DataHolder(build.Data(sources, install_dir, install_mode))
        self.build.data.append(data.held_object)
        return data

    @stringArgs
    def func_install_subdir(self, node, args, kwargs):
        if len(args) != 1:
            raise InvalidArguments('Install_subdir requires exactly one argument.')
        if 'install_dir' not in kwargs:
            raise InvalidArguments('Missing keyword argument install_dir')
        install_dir = kwargs['install_dir']
        if not isinstance(install_dir, str):
            raise InvalidArguments('Keyword argument install_dir not a string.')
        install_mode = self._get_kwarg_install_mode(kwargs)
        idir = InstallDir(self.subdir, args[0], install_dir, install_mode)
        self.build.install_dirs.append(idir)
        return idir

    def func_configure_file(self, node, args, kwargs):
        if len(args) > 0:
            raise InterpreterException("configure_file takes only keyword arguments.")
        if 'output' not in kwargs:
            raise InterpreterException('Required keyword argument "output" not defined.')
        inputfile = kwargs.get('input', None)
        output = kwargs['output']
        if not isinstance(inputfile, (str, type(None))):
            raise InterpreterException('Input must be a string.')
        if not isinstance(output, str):
            raise InterpreterException('Output must be a string.')
        if os.path.split(output)[0] != '':
            raise InterpreterException('Output file name must not contain a subdirectory.')
        (ofile_path, ofile_fname) = os.path.split(os.path.join(self.subdir, output))
        ofile_abs = os.path.join(self.environment.build_dir, ofile_path, ofile_fname)
        if 'configuration' in kwargs:
            conf = kwargs['configuration']
            if not isinstance(conf, ConfigurationDataHolder):
                raise InterpreterException('Argument "configuration" is not of type configuration_data')
            if inputfile is not None:
                # Normalize the path of the conffile to avoid duplicates
                # This is especially important to convert '/' to '\' on Windows
                conffile = os.path.normpath(os.path.join(self.subdir, inputfile))
                if conffile not in self.build_def_files:
                    self.build_def_files.append(conffile)
                os.makedirs(os.path.join(self.environment.build_dir, self.subdir), exist_ok=True)
                ifile_abs = os.path.join(self.environment.source_dir, self.subdir, inputfile)
                mesonlib.do_conf_file(ifile_abs, ofile_abs, conf.held_object)
            else:
                mesonlib.dump_conf_header(ofile_abs, conf.held_object)
            conf.mark_used()
        elif 'command' in kwargs:
            if 'input' not in kwargs:
                raise InterpreterException('Required keyword input missing.')
            res = self.func_run_command(node, kwargs['command'], {})
            if res.returncode != 0:
                raise InterpreterException('Running configure command failed.\n%s\n%s' %
                                           (res.stdout, res.stderr))
        else:
            raise InterpreterException('Configure_file must have either "configuration" or "command".')
        idir = kwargs.get('install_dir', None)
        if isinstance(idir, str):
            cfile = mesonlib.File.from_built_file(ofile_path, ofile_fname)
            self.build.data.append(build.Data([cfile], idir))
        return mesonlib.File.from_built_file(self.subdir, output)

    @stringArgs
    def func_include_directories(self, node, args, kwargs):
        absbase = os.path.join(self.environment.get_source_dir(), self.subdir)
        for a in args:
            absdir = os.path.join(absbase, a)
            if not os.path.isdir(absdir):
                raise InvalidArguments('Include dir %s does not exist.' % a)
        is_system = kwargs.get('is_system', False)
        if not isinstance(is_system, bool):
            raise InvalidArguments('Is_system must be boolean.')
        i = IncludeDirsHolder(build.IncludeDirs(self.subdir, args, is_system))
        return i

    @stringArgs
    def func_add_test_setup(self, node, args, kwargs):
        if len(args) != 1:
            raise InterpreterException('Add_test_setup needs one argument for the setup name.')
        setup_name = args[0]
        if re.fullmatch('[_a-zA-Z][_0-9a-zA-Z]*', setup_name) is None:
            raise InterpreterException('Setup name may only contain alphanumeric characters.')
        try:
            inp = kwargs.get('exe_wrapper', [])
            if not isinstance(inp, list):
                inp = [inp]
            exe_wrapper = []
            for i in inp:
                if hasattr(i, 'held_object'):
                    i = i.held_object
                if isinstance(i, str):
                    exe_wrapper.append(i)
                elif isinstance(i, dependencies.ExternalProgram):
                    if not i.found():
                        raise InterpreterException('Tried to use non-found external executable.')
                    exe_wrapper += i.get_command()
                else:
                    raise InterpreterException('Exe wrapper can only contain strings or external binaries.')
        except KeyError:
            exe_wrapper = None
        gdb = kwargs.get('gdb', False)
        if not isinstance(gdb, bool):
            raise InterpreterException('Gdb option must be a boolean')
        timeout_multiplier = kwargs.get('timeout_multiplier', 1)
        if not isinstance(timeout_multiplier, int):
            raise InterpreterException('Timeout multiplier must be a number.')
        env = self.unpack_env_kwarg(kwargs)
        setupobj = build.TestSetup(exe_wrapper=exe_wrapper,
                                   gdb=gdb,
                                   timeout_multiplier=timeout_multiplier,
                                   env=env)
        if self.subproject == '':
            # Dunno what we should do with subprojects really. Let's start simple
            # and just use the master project ones.
            self.build.test_setups[setup_name] = setupobj

    @stringArgs
    def func_add_global_arguments(self, node, args, kwargs):
        if self.subproject != '':
            msg = 'Global arguments can not be set in subprojects because ' \
                  'there is no way to make that reliable.\nPlease only call ' \
                  'this if is_subproject() returns false. Alternatively, ' \
                  'define a variable that\ncontains your language-specific ' \
                  'arguments and add it to the appropriate *_args kwarg ' \
                  'in each target.'
            raise InvalidCode(msg)
        if self.args_frozen:
            msg = 'Tried to set global arguments after a build target has ' \
                  'been declared.\nThis is not permitted. Please declare all ' \
                  'global arguments before your targets.'
            raise InvalidCode(msg)
        if 'language' not in kwargs:
            raise InvalidCode('Missing language definition in add_global_arguments')
        lang = kwargs['language'].lower()
        if lang in self.build.global_args:
            self.build.global_args[lang] += args
        else:
            self.build.global_args[lang] = args

    @stringArgs
    def func_add_global_link_arguments(self, node, args, kwargs):
        if self.subproject != '':
            msg = 'Global link arguments can not be set in subprojects because ' \
                  'there is no way to make that reliable.\nPlease only call ' \
                  'this if is_subproject() returns false. Alternatively, ' \
                  'define a variable that\ncontains your language-specific ' \
                  'arguments and add it to the appropriate *_args kwarg ' \
                  'in each target.'
            raise InvalidCode(msg)
        if self.args_frozen:
            msg = 'Tried to set global link arguments after a build target has ' \
                  'been declared.\nThis is not permitted. Please declare all ' \
                  'global arguments before your targets.'
            raise InvalidCode(msg)
        if 'language' not in kwargs:
            raise InvalidCode('Missing language definition in add_global_link_arguments')
        lang = kwargs['language'].lower()
        if lang in self.build.global_link_args:
            self.build.global_link_args[lang] += args
        else:
            self.build.global_link_args[lang] = args

    @stringArgs
    def func_add_project_link_arguments(self, node, args, kwargs):
        if self.args_frozen:
            msg = 'Tried to set project link arguments after a build target has ' \
                  'been declared.\nThis is not permitted. Please declare all ' \
                  'project link arguments before your targets.'
            raise InvalidCode(msg)
        if 'language' not in kwargs:
            raise InvalidCode('Missing language definition in add_project_link_arguments')
        lang = kwargs['language'].lower()
        if self.subproject not in self.build.projects_link_args:
            self.build.projects_link_args[self.subproject] = {}

        args = self.build.projects_link_args[self.subproject].get(lang, []) + args
        self.build.projects_link_args[self.subproject][lang] = args

    @stringArgs
    def func_add_project_arguments(self, node, args, kwargs):
        if self.args_frozen:
            msg = 'Tried to set project arguments after a build target has ' \
                  'been declared.\nThis is not permitted. Please declare all ' \
                  'project arguments before your targets.'
            raise InvalidCode(msg)

        if 'language' not in kwargs:
            raise InvalidCode('Missing language definition in add_project_arguments')

        if self.subproject not in self.build.projects_args:
            self.build.projects_args[self.subproject] = {}

        lang = kwargs['language'].lower()
        args = self.build.projects_args[self.subproject].get(lang, []) + args
        self.build.projects_args[self.subproject][lang] = args

    def func_environment(self, node, args, kwargs):
        return EnvironmentVariablesHolder()

    @stringArgs
    @noKwargs
    def func_join_paths(self, node, args, kwargs):
        return os.path.join(*args).replace('\\', '/')

    def run(self):
        super().run()
        mlog.log('Build targets in project:', mlog.bold(str(len(self.build.targets))))

    def source_strings_to_files(self, sources):
        results = []
        for s in sources:
            if isinstance(s, (mesonlib.File, GeneratedListHolder,
                              CustomTargetHolder)):
                pass
            elif isinstance(s, str):
                s = mesonlib.File.from_source_file(self.environment.source_dir, self.subdir, s)
            else:
                raise InterpreterException("Source item is not string or File-type object.")
            results.append(s)
        return results

    def add_target(self, name, tobj):
        if name == '':
            raise InterpreterException('Target name must not be empty.')
        if name in coredata.forbidden_target_names:
            raise InvalidArguments('Target name "%s" is reserved for Meson\'s internal use. Please rename.'
                                   % name)
        # To permit an executable and a shared library to have the
        # same name, such as "foo.exe" and "libfoo.a".
        idname = tobj.get_id()
        if idname in self.build.targets:
            raise InvalidCode('Tried to create target "%s", but a target of that name already exists.' % name)
        self.build.targets[idname] = tobj
        if idname not in self.coredata.target_guids:
            self.coredata.target_guids[idname] = str(uuid.uuid4()).upper()

    def build_target(self, node, args, kwargs, targetholder):
        if len(args) == 0:
            raise InterpreterException('Target does not have a name.')
        name = args[0]
        sources = args[1:]
        if self.environment.is_cross_build():
            if kwargs.get('native', False):
                is_cross = False
            else:
                is_cross = True
        else:
            is_cross = False
        try:
            kw_src = self.flatten(kwargs['sources'])
            if not isinstance(kw_src, list):
                kw_src = [kw_src]
        except KeyError:
            kw_src = []
        sources += kw_src
        sources = self.source_strings_to_files(sources)
        objs = self.flatten(kwargs.get('objects', []))
        kwargs['dependencies'] = self.flatten(kwargs.get('dependencies', []))
        if not isinstance(objs, list):
            objs = [objs]
        self.check_sources_exist(os.path.join(self.source_root, self.subdir), sources)
        if targetholder is ExecutableHolder:
            targetclass = build.Executable
        elif targetholder is SharedLibraryHolder:
            targetclass = build.SharedLibrary
        elif targetholder is SharedModuleHolder:
            targetclass = build.SharedModule
        elif targetholder is StaticLibraryHolder:
            targetclass = build.StaticLibrary
        elif targetholder is JarHolder:
            targetclass = build.Jar
        else:
            mlog.debug('Unknown target type:', str(targetholder))
            raise RuntimeError('Unreachable code')
        target = targetclass(name, self.subdir, self.subproject, is_cross, sources, objs, self.environment, kwargs)
        if is_cross:
            self.add_cross_stdlib_info(target)
        l = targetholder(target, self)
        self.add_target(name, l.held_object)
        self.args_frozen = True
        return l

    def get_used_languages(self, target):
        result = {}
        for i in target.sources:
            for lang, c in self.build.compilers.items():
                if c.can_compile(i):
                    result[lang] = True
                    break
        return result

    def add_cross_stdlib_info(self, target):
        for l in self.get_used_languages(target):
            if self.environment.cross_info.has_stdlib(l) \
                    and self.subproject != self.environment.cross_info.get_stdlib(l)[0]:
                target.add_deps(self.build.cross_stdlibs[l])

    def check_sources_exist(self, subdir, sources):
        for s in sources:
            if not isinstance(s, str):
                continue # This means a generated source and they always exist.
            fname = os.path.join(subdir, s)
            if not os.path.isfile(fname):
                raise InterpreterException('Tried to add non-existing source file %s.' % s)

    def format_string(self, templ, args):
        templ = self.to_native(templ)
        if isinstance(args, mparser.ArgumentNode):
            args = args.arguments
        for (i, arg) in enumerate(args):
            arg = self.to_native(self.evaluate_statement(arg))
            if isinstance(arg, bool): # Python boolean is upper case.
                arg = str(arg).lower()
            templ = templ.replace('@{}@'.format(i), str(arg))
        return templ

    # Only permit object extraction from the same subproject
    def validate_extraction(self, buildtarget):
        if not self.subdir.startswith(self.subproject_dir):
            if buildtarget.subdir.startswith(self.subproject_dir):
                raise InterpreterException('Tried to extract objects from a subproject target.')
        else:
            if not buildtarget.subdir.startswith(self.subproject_dir):
                raise InterpreterException('Tried to extract objects from the main project from a subproject.')
            if self.subdir.split('/')[1] != buildtarget.subdir.split('/')[1]:
                raise InterpreterException('Tried to extract objects from a different subproject.')

    def check_contains(self, obj, args):
        if len(args) != 1:
            raise InterpreterException('Contains method takes exactly one argument.')
        item = args[0]
        for element in obj:
            if isinstance(element, list):
                found = self.check_contains(element, args)
                if found:
                    return True
            try:
                if element == item:
                    return True
            except Exception:
                pass
        return False

    def is_subproject(self):
        return self.subproject != ''