meson/mesonbuild/compilers.py

# Copyright 2012-2014 The Meson development team

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import shutil
import contextlib
import subprocess, os.path
import tempfile
from .import mesonlib
from . import mlog
from .mesonlib import EnvironmentException, MesonException, version_compare, Popen_safe
from . import coredata

"""This file contains the data files of all compilers Meson knows
about. To support a new compiler, add its information below.
Also add corresponding autodetection code in environment.py."""

header_suffixes = ('h', 'hh', 'hpp', 'hxx', 'H', 'ipp', 'moc', 'vapi', 'di')
obj_suffixes = ('o', 'obj', 'res')
lib_suffixes = ('a', 'lib', 'dll', 'dylib', 'so')
# Mapping of language to suffixes of files that should always be in that language
# This means we can't include .h headers here since they could be C, C++, ObjC, etc.
lang_suffixes = {
    'c': ('c',),
    'cpp': ('cpp', 'cc', 'cxx', 'c++', 'hh', 'hpp', 'ipp', 'hxx'),
    'fortran': ('f', 'f90', 'f95'),
    'd': ('d', 'di'),
    'objc': ('m',),
    'objcpp': ('mm',),
    'rust': ('rs',),
    'vala': ('vala', 'vapi'),
    'cs': ('cs',),
    'swift': ('swift',),
    'java': ('java',),
}
cpp_suffixes = lang_suffixes['cpp'] + ('h',)
c_suffixes = lang_suffixes['c'] + ('h',)
# List of languages that can be linked with C code directly by the linker
# used in build.py:process_compilers() and build.py:get_dynamic_linker()
clike_langs = ('objcpp', 'objc', 'd', 'cpp', 'c', 'fortran',)
clike_suffixes = ()
for l in clike_langs:
    clike_suffixes += lang_suffixes[l]
clike_suffixes += ('h',)

# These are used in backend/backends.py:generated_target()
def is_header(fname):
    if hasattr(fname, 'fname'):
        fname = fname.fname
    suffix = fname.split('.')[-1]
    return suffix in header_suffixes

def is_source(fname):
    if hasattr(fname, 'fname'):
        fname = fname.fname
    suffix = fname.split('.')[-1]
    return suffix in clike_suffixes

def is_assembly(fname):
    if hasattr(fname, 'fname'):
        fname = fname.fname
    return fname.split('.')[-1].lower() == 's'

def is_llvm_ir(fname):
    if hasattr(fname, 'fname'):
        fname = fname.fname
    return fname.split('.')[-1] == 'll'

def is_object(fname):
    if hasattr(fname, 'fname'):
        fname = fname.fname
    suffix = fname.split('.')[-1]
    return suffix in obj_suffixes

def is_library(fname):
    if hasattr(fname, 'fname'):
        fname = fname.fname
    suffix = fname.split('.')[-1]
    return suffix in lib_suffixes

gnulike_buildtype_args = {'plain': [],
                          # -O0 is passed for improved debugging information with gcc
                          # See https://github.com/mesonbuild/meson/pull/509
                          'debug': ['-O0', '-g'],
                          'debugoptimized': ['-O2', '-g'],
                          'release': ['-O3'],
                          'minsize': ['-Os', '-g']}

msvc_buildtype_args = {'plain': [],
                       'debug': ["/MDd", "/ZI", "/Ob0", "/Od", "/RTC1"],
                       'debugoptimized': ["/MD", "/Zi", "/O2", "/Ob1"],
                       'release': ["/MD", "/O2", "/Ob2"],
                       'minsize': ["/MD", "/Zi", "/Os", "/Ob1"],
                       }

apple_buildtype_linker_args = {'plain': [],
                               'debug': [],
                               'debugoptimized': [],
                               'release': [],
                               'minsize': [],
                               }

gnulike_buildtype_linker_args = {'plain': [],
                                 'debug': [],
                                 'debugoptimized': [],
                                 'release': ['-Wl,-O1'],
                                 'minsize': [],
                                 }

msvc_buildtype_linker_args = {'plain': [],
                              'debug': [],
                              'debugoptimized': [],
                              'release': [],
                              'minsize': ['/INCREMENTAL:NO'],
                              }

java_buildtype_args = {'plain': [],
                       'debug': ['-g'],
                       'debugoptimized': ['-g'],
                       'release': [],
                       'minsize': [],
                       }

rust_buildtype_args = {'plain': [],
                       'debug': ['-g'],
                       'debugoptimized': ['-g', '--opt-level', '2'],
                       'release': ['--opt-level', '3'],
                       'minsize': [],
                       }

d_gdc_buildtype_args = {'plain': [],
                        'debug': ['-g', '-O0'],
                        'debugoptimized': ['-g', '-O'],
                        'release': ['-O3', '-frelease'],
                        'minsize': [],
                        }

d_ldc_buildtype_args = {'plain': [],
                        'debug': ['-g', '-O0'],
                        'debugoptimized': ['-g', '-O'],
                        'release': ['-O3', '-release'],
                        'minsize': [],
                        }

d_dmd_buildtype_args = {'plain': [],
                        'debug': ['-g'],
                        'debugoptimized': ['-g', '-O'],
                        'release': ['-O', '-release'],
                        'minsize': [],
                        }

mono_buildtype_args = {'plain': [],
                       'debug': ['-debug'],
                       'debugoptimized': ['-debug', '-optimize+'],
                       'release': ['-optimize+'],
                       'minsize': [],
                       }

swift_buildtype_args = {'plain': [],
                        'debug': ['-g'],
                        'debugoptimized': ['-g', '-O'],
                        'release': ['-O'],
                        'minsize': [],
                        }

gnu_winlibs = ['-lkernel32', '-luser32', '-lgdi32', '-lwinspool', '-lshell32',
               '-lole32', '-loleaut32', '-luuid', '-lcomdlg32', '-ladvapi32']

msvc_winlibs = ['kernel32.lib', 'user32.lib', 'gdi32.lib',
                'winspool.lib', 'shell32.lib', 'ole32.lib', 'oleaut32.lib',
                'uuid.lib', 'comdlg32.lib', 'advapi32.lib']

gnu_color_args = {'auto': ['-fdiagnostics-color=auto'],
                  'always': ['-fdiagnostics-color=always'],
                  'never': ['-fdiagnostics-color=never'],
                  }

base_options = {
                'b_pch': coredata.UserBooleanOption('b_pch', 'Use precompiled headers', True),
                'b_lto': coredata.UserBooleanOption('b_lto', 'Use link time optimization', False),
                'b_sanitize': coredata.UserComboOption('b_sanitize',
                                                       'Code sanitizer to use',
                                                       ['none', 'address', 'thread', 'undefined', 'memory'],
                                                       'none'),
                'b_lundef': coredata.UserBooleanOption('b_lundef', 'Use -Wl,--no-undefined when linking', True),
                'b_asneeded': coredata.UserBooleanOption('b_asneeded', 'Use -Wl,--as-needed when linking', True),
                'b_pgo': coredata.UserComboOption('b_pgo', 'Use profile guide optimization',
                                                  ['off', 'generate', 'use'],
                                                  'off'),
                'b_coverage': coredata.UserBooleanOption('b_coverage',
                                                         'Enable coverage tracking.',
                                                         False),
                'b_colorout': coredata.UserComboOption('b_colorout', 'Use colored output',
                                                        ['auto', 'always', 'never'],
                                                        'always'),
                'b_ndebug': coredata.UserBooleanOption('b_ndebug',
                                                       'Disable asserts',
                                                       False),
                'b_staticpic': coredata.UserBooleanOption('b_staticpic',
                                                          'Build static libraries as position independent',
                                                          True),
                }

def sanitizer_compile_args(value):
    if value == 'none':
        return []
    args = ['-fsanitize=' + value]
    if value == 'address':
        args.append('-fno-omit-frame-pointer')
    return args

def sanitizer_link_args(value):
    if value == 'none':
        return []
    args = ['-fsanitize=' + value]
    return args

def get_base_compile_args(options, compiler):
    args = []
    # FIXME, gcc/clang specific.
    try:
        if options['b_lto'].value:
            args.append('-flto')
    except KeyError:
        pass
    try:
        args += compiler.get_colorout_args(options['b_colorout'].value)
    except KeyError:
        pass
    try:
        args += sanitizer_compile_args(options['b_sanitize'].value)
    except KeyError:
        pass
    try:
        pgo_val = options['b_pgo'].value
        if pgo_val == 'generate':
            args.append('-fprofile-generate')
        elif pgo_val == 'use':
            args.append('-fprofile-use')
    except KeyError:
        pass
    try:
        if options['b_coverage'].value:
            args += compiler.get_coverage_args()
    except KeyError:
        pass
    try:
        if options['b_ndebug'].value:
            args += ['-DNDEBUG']
    except KeyError:
        pass
    return args

def get_base_link_args(options, linker, is_shared_module):
    args = []
    # FIXME, gcc/clang specific.
    try:
        if options['b_lto'].value:
            args.append('-flto')
    except KeyError:
        pass
    try:
        args += sanitizer_link_args(options['b_sanitize'].value)
    except KeyError:
        pass
    try:
        pgo_val = options['b_pgo'].value
        if pgo_val == 'generate':
            args.append('-fprofile-generate')
        elif pgo_val == 'use':
            args.append('-fprofile-use')
    except KeyError:
        pass
    try:
        if not is_shared_module and 'b_lundef' in linker.base_options and options['b_lundef'].value:
            args.append('-Wl,--no-undefined')
    except KeyError:
        pass
    try:
        if 'b_asneeded' in linker.base_options and options['b_asneeded'].value:
            args.append('-Wl,--as-needed')
    except KeyError:
        pass
    try:
        if options['b_coverage'].value:
            args += linker.get_coverage_link_args()
    except KeyError:
        pass
    return args

def build_unix_rpath_args(build_dir, rpath_paths, install_rpath):
        if len(rpath_paths) == 0 and len(install_rpath) == 0:
            return []
        paths = ':'.join([os.path.join(build_dir, p) for p in rpath_paths])
        if len(paths) < len(install_rpath):
            padding = 'X' * (len(install_rpath) - len(paths))
            if len(paths) == 0:
                paths = padding
            else:
                paths = paths + ':' + padding
        return ['-Wl,-rpath,' + paths]

class CrossNoRunException(MesonException):
    def __init(self, *args, **kwargs):
        Exception.__init__(self, *args, **kwargs)

class RunResult():
    def __init__(self, compiled, returncode=999, stdout='UNDEFINED', stderr='UNDEFINED'):
        self.compiled = compiled
        self.returncode = returncode
        self.stdout = stdout
        self.stderr = stderr

class Compiler():
    def __init__(self, exelist, version):
        if type(exelist) == type(''):
            self.exelist = [exelist]
        elif type(exelist) == type([]):
            self.exelist = exelist
        else:
            raise TypeError('Unknown argument to Compiler')
        # In case it's been overriden by a child class already
        if not hasattr(self, 'file_suffixes'):
            self.file_suffixes = lang_suffixes[self.language]
        if not hasattr(self, 'can_compile_suffixes'):
            self.can_compile_suffixes = set(self.file_suffixes)
        self.default_suffix = self.file_suffixes[0]
        self.version = version
        self.base_options = []

    def can_compile(self, src):
        if hasattr(src, 'fname'):
            src = src.fname
        suffix = os.path.splitext(src)[1].lower()
        if suffix and suffix[1:] in self.can_compile_suffixes:
            return True
        return False

    def get_id(self):
        return self.id

    def get_language(self):
        return self.language

    def get_default_suffix(self):
        return self.default_suffix

    def get_exelist(self):
        return self.exelist[:]

    def get_define(self, *args, **kwargs):
        raise EnvironmentException('%s does not support get_define.' % self.id)

    def has_define(self, *args, **kwargs):
        raise EnvironmentException('%s does not support has_define.' % self.id)

    def get_always_args(self):
        return []

    def get_linker_always_args(self):
        return []

    def gen_import_library_args(self, implibname):
        """
        Used only on Windows for libraries that need an import library.
        This currently means C, C++, Fortran.
        """
        return []

    def get_options(self):
        return {} # build afresh every time

    def get_option_compile_args(self, options):
        return []

    def get_option_link_args(self, options):
        return []

    def has_header(self, *args, **kwargs):
        raise EnvironmentException('Language %s does not support header checks.' % self.language)

    def has_header_symbol(self, *args, **kwargs):
        raise EnvironmentException('Language %s does not support header symbol checks.' % self.language)

    def compiles(self, *args, **kwargs):
        raise EnvironmentException('Language %s does not support compile checks.' % self.language)

    def links(self, *args, **kwargs):
        raise EnvironmentException('Language %s does not support link checks.' % self.language)

    def run(self, *args, **kwargs):
        raise EnvironmentException('Language %s does not support run checks.' % self.language)

    def sizeof(self, *args, **kwargs):
        raise EnvironmentException('Language %s does not support sizeof checks.' % self.language)

    def alignment(self, *args, **kwargs):
        raise EnvironmentException('Language %s does not support alignment checks.' % self.language)

    def has_function(self, *args, **kwargs):
        raise EnvironmentException('Language %s does not support function checks.' % self.language)

    def unix_link_flags_to_native(self, args):
        "Always returns a copy that can be independently mutated"
        return args[:]

    def unix_compile_flags_to_native(self, args):
        "Always returns a copy that can be independently mutated"
        return args[:]

    def find_library(self, *args, **kwargs):
        raise EnvironmentException('Language {} does not support library finding.'.format(self.language))

    def get_library_dirs(self):
        return []

    def has_argument(self, arg, env):
        return self.has_multi_arguments([arg], env)

    def has_multi_arguments(self, args, env):
        raise EnvironmentException(
            'Language {} does not support has_multi_arguments.'.format(
                self.language))

    def get_cross_extra_flags(self, environment, *, compile, link):
        extra_flags = []
        if self.is_cross and environment:
            if 'properties' in environment.cross_info.config:
                lang_args_key = self.language + '_args'
                if compile:
                    extra_flags += environment.cross_info.config['properties'].get(lang_args_key, [])
                lang_link_args_key = self.language + '_link_args'
                if link:
                    extra_flags += environment.cross_info.config['properties'].get(lang_link_args_key, [])
        return extra_flags

    def _get_compile_output(self, dirname, mode):
        # In pre-processor mode, the output is sent to stdout and discarded
        if mode == 'preprocess':
            return None
        # Extension only matters if running results; '.exe' is
        # guaranteed to be executable on every platform.
        if mode == 'link':
            suffix = 'exe'
        else:
            suffix = 'obj'
        return os.path.join(dirname, 'output.' + suffix)

    @contextlib.contextmanager
    def compile(self, code, extra_args=None, mode='link'):
        if extra_args is None:
            extra_args = []
        try:
            with tempfile.TemporaryDirectory() as tmpdirname:
                if isinstance(code, str):
                    srcname = os.path.join(tmpdirname,
                                           'testfile.' + self.default_suffix)
                    with open(srcname, 'w') as ofile:
                        ofile.write(code)
                elif isinstance(code, mesonlib.File):
                    srcname = code.fname
                output = self._get_compile_output(tmpdirname, mode)

                # Construct the compiler command-line
                commands = self.get_exelist()
                commands.append(srcname)
                commands += extra_args
                commands += self.get_always_args()
                if mode == 'compile':
                    commands += self.get_compile_only_args()
                # Preprocess mode outputs to stdout, so no output args
                if mode == 'preprocess':
                    commands += self.get_preprocess_only_args()
                else:
                    commands += self.get_output_args(output)
                mlog.debug('Running compile:')
                mlog.debug('Working directory: ', tmpdirname)
                mlog.debug('Command line: ', ' '.join(commands), '\n')
                mlog.debug('Code:\n', code)
                p, p.stdo, p.stde = Popen_safe(commands, cwd=tmpdirname)
                mlog.debug('Compiler stdout:\n', p.stdo)
                mlog.debug('Compiler stderr:\n', p.stde)
                p.input_name = srcname
                p.output_name = output
                yield p
        except (PermissionError, OSError):
            # On Windows antivirus programs and the like hold on to files so
            # they can't be deleted. There's not much to do in this case. Also,
            # catch OSError because the directory is then no longer empty.
            pass

    def get_colorout_args(self, colortype):
        return []

    # Some compilers (msvc) write debug info to a separate file.
    # These args specify where it should be written.
    def get_compile_debugfile_args(self, rel_obj, **kwargs):
        return []

    def get_link_debugfile_args(self, rel_obj):
        return []

    def get_std_shared_lib_link_args(self):
        return []

    def get_std_shared_module_link_args(self):
        return self.get_std_shared_lib_link_args()

class CCompiler(Compiler):
    def __init__(self, exelist, version, is_cross, exe_wrapper=None):
        # If a child ObjC or CPP class has already set it, don't set it ourselves
        if not hasattr(self, 'language'):
            self.language = 'c'
        super().__init__(exelist, version)
        self.id = 'unknown'
        self.is_cross = is_cross
        self.can_compile_suffixes.add('h')
        if isinstance(exe_wrapper, str):
            self.exe_wrapper = [exe_wrapper]
        else:
            self.exe_wrapper = exe_wrapper

    def needs_static_linker(self):
        return True # When compiling static libraries, so yes.

    def get_always_args(self):
        return []

    def get_linker_debug_crt_args(self):
        """
        Arguments needed to select a debug crt for the linker
        This is only needed for MSVC
        """
        return []

    def get_no_stdinc_args(self):
        return ['-nostdinc']

    def get_no_stdlib_link_args(self):
        return ['-nostdlib']

    def get_warn_args(self, level):
        return self.warn_args[level]

    def get_no_warn_args(self):
        # Almost every compiler uses this for disabling warnings
        return ['-w']

    def get_soname_args(self, prefix, shlib_name, suffix, path, soversion, is_shared_module):
        return []

    def split_shlib_to_parts(self, fname):
        return (None, fname)

    # The default behaviour is this, override in
    # OSX and MSVC.
    def build_rpath_args(self, build_dir, rpath_paths, install_rpath):
        return build_unix_rpath_args(build_dir, rpath_paths, install_rpath)

    def get_dependency_gen_args(self, outtarget, outfile):
        return ['-MMD', '-MQ', outtarget, '-MF', outfile]

    def depfile_for_object(self, objfile):
        return objfile + '.' + self.get_depfile_suffix()

    def get_depfile_suffix(self):
        return 'd'

    def get_exelist(self):
        return self.exelist[:]

    def get_linker_exelist(self):
        return self.exelist[:]

    def get_preprocess_only_args(self):
        return ['-E']

    def get_compile_only_args(self):
        return ['-c']

    def get_no_optimization_args(self):
        return ['-O0']

    def get_compiler_check_args(self):
        '''
        Get arguments useful for compiler checks such as being permissive in
        the code quality and not doing any optimization.
        '''
        return self.get_no_optimization_args()

    def get_output_args(self, target):
        return ['-o', target]

    def get_linker_output_args(self, outputname):
        return ['-o', outputname]

    def get_coverage_args(self):
        return ['--coverage']

    def get_coverage_link_args(self):
        return ['-lgcov']

    def get_werror_args(self):
        return ['-Werror']

    def get_std_exe_link_args(self):
        return []

    def get_include_args(self, path, is_system):
        if path == '':
            path = '.'
        if is_system:
            return ['-isystem', path]
        return ['-I' + path]

    def get_std_shared_lib_link_args(self):
        return ['-shared']

    def get_library_dirs(self):
        stdo = Popen_safe(self.exelist + ['--print-search-dirs'])[1]
        for line in stdo.split('\n'):
            if line.startswith('libraries:'):
                libstr = line.split('=', 1)[1]
                return libstr.split(':')
        return []

    def get_pic_args(self):
        return ['-fPIC']

    def name_string(self):
        return ' '.join(self.exelist)

    def get_pch_use_args(self, pch_dir, header):
        return ['-include', os.path.split(header)[-1]]

    def get_pch_name(self, header_name):
        return os.path.split(header_name)[-1] + '.' + self.get_pch_suffix()

    def get_linker_search_args(self, dirname):
        return ['-L' + dirname]

    def gen_import_library_args(self, implibname):
        """
        The name of the outputted import library

        This implementation is used only on Windows by compilers that use GNU ld
        """
        return ['-Wl,--out-implib=' + implibname]

    def sanity_check_impl(self, work_dir, environment, sname, code):
        mlog.debug('Sanity testing ' + self.language + ' compiler:', ' '.join(self.exelist))
        mlog.debug('Is cross compiler: %s.' % str(self.is_cross))

        extra_flags = []
        source_name = os.path.join(work_dir, sname)
        binname = sname.rsplit('.', 1)[0]
        if self.is_cross:
            binname += '_cross'
            if self.exe_wrapper is None:
                # Linking cross built apps is painful. You can't really
                # tell if you should use -nostdlib or not and for example
                # on OSX the compiler binary is the same but you need
                # a ton of compiler flags to differentiate between
                # arm and x86_64. So just compile.
                extra_flags += self.get_cross_extra_flags(environment, compile=True, link=False)
                extra_flags += self.get_compile_only_args()
            else:
                extra_flags += self.get_cross_extra_flags(environment, compile=True, link=True)
        # Is a valid executable output for all toolchains and platforms
        binname += '.exe'
        # Write binary check source
        binary_name = os.path.join(work_dir, binname)
        with open(source_name, 'w') as ofile:
            ofile.write(code)
        # Compile sanity check
        cmdlist = self.exelist + extra_flags + [source_name] + self.get_output_args(binary_name)
        pc, stdo, stde = Popen_safe(cmdlist, cwd=work_dir)
        mlog.debug('Sanity check compiler command line:', ' '.join(cmdlist))
        mlog.debug('Sanity check compile stdout:')
        mlog.debug(stdo)
        mlog.debug('-----\nSanity check compile stderr:')
        mlog.debug(stde)
        mlog.debug('-----')
        if pc.returncode != 0:
            raise EnvironmentException('Compiler {0} can not compile programs.'.format(self.name_string()))
        # Run sanity check
        if self.is_cross:
            if self.exe_wrapper is None:
                # Can't check if the binaries run so we have to assume they do
                return
            cmdlist = self.exe_wrapper + [binary_name]
        else:
            cmdlist = [binary_name]
        mlog.debug('Running test binary command: ' + ' '.join(cmdlist))
        pe = subprocess.Popen(cmdlist)
        pe.wait()
        if pe.returncode != 0:
            raise EnvironmentException('Executables created by {0} compiler {1} are not runnable.'.format(self.language, self.name_string()))

    def sanity_check(self, work_dir, environment):
        code = 'int main(int argc, char **argv) { int class=0; return class; }\n'
        return self.sanity_check_impl(work_dir, environment, 'sanitycheckc.c', code)

    def has_header(self, hname, prefix, env, extra_args=None, dependencies=None):
        if extra_args is None:
            extra_args = []
        code = '{}\n#include<{}>\nint someUselessSymbol;'.format(prefix, hname)
        return self.compiles(code, env, extra_args, dependencies, 'preprocess')

    def has_header_symbol(self, hname, symbol, prefix, env, extra_args=None, dependencies=None):
        if extra_args is None:
            extra_args = []
        templ = '''{2}
#include <{0}>
int main () {{
  /* If it's not defined as a macro, try to use as a symbol */
  #ifndef {1}
    {1};
  #endif
  return 0;
}}'''
        return self.compiles(templ.format(hname, symbol, prefix), env,
                             extra_args, dependencies)

    @staticmethod
    def _override_args(args, override):
        '''
        Add @override to @args in such a way that arguments are overriden
        correctly.

        We want the include directories to be added first (since they are
        chosen left-to-right) and all other arguments later (since they
        override previous arguments or add to a list that's chosen
        right-to-left).
        '''
        before_args = []
        after_args = []
        for arg in override:
            if arg.startswith(('-I', '/I')):
                before_args.append(arg)
            else:
                after_args.append(arg)
        return before_args + args + after_args

    def compiles(self, code, env, extra_args=None, dependencies=None, mode='compile'):
        if extra_args is None:
            extra_args = []
        if isinstance(extra_args, str):
            extra_args = [extra_args]
        if dependencies is None:
            dependencies = []
        elif not isinstance(dependencies, list):
            dependencies = [dependencies]
        # Add compile flags needed by dependencies after converting to the
        # native type of the selected compiler
        cargs = [a for d in dependencies for a in d.get_compile_args()]
        args = self.unix_link_flags_to_native(cargs)
        # Read c_args/cpp_args/etc from the cross-info file (if needed)
        args += self.get_cross_extra_flags(env, compile=True, link=False)
        # Add CFLAGS/CXXFLAGS/OBJCFLAGS/OBJCXXFLAGS from the env
        # We assume that the user has ensured these are compiler-specific
        args += env.coredata.external_args[self.language]
        # Append extra_args to the compiler check args such that it overrides
        extra_args = self._override_args(self.get_compiler_check_args(), extra_args)
        extra_args = self.unix_link_flags_to_native(extra_args)
        # Append both to the compiler args such that they override them
        args = self._override_args(args, extra_args)
        # We only want to compile; not link
        with self.compile(code, args, mode) as p:
            return p.returncode == 0

    def _links_wrapper(self, code, env, extra_args, dependencies):
        "Shares common code between self.links and self.run"
        if extra_args is None:
            extra_args = []
        elif isinstance(extra_args, str):
            extra_args = [extra_args]
        if dependencies is None:
            dependencies = []
        elif not isinstance(dependencies, list):
            dependencies = [dependencies]
        # Add compile and link flags needed by dependencies after converting to
        # the native type of the selected compiler
        cargs = [a for d in dependencies for a in d.get_compile_args()]
        link_args = [a for d in dependencies for a in d.get_link_args()]
        args = self.unix_link_flags_to_native(cargs + link_args)
        # Select a CRT if needed since we're linking
        args += self.get_linker_debug_crt_args()
        # Read c_args/c_link_args/cpp_args/cpp_link_args/etc from the
        # cross-info file (if needed)
        args += self.get_cross_extra_flags(env, compile=True, link=True)
        # Add LDFLAGS from the env. We assume that the user has ensured these
        # are compiler-specific
        args += env.coredata.external_link_args[self.language]
        # Append extra_args to the compiler check args such that it overrides
        extra_args = self._override_args(self.get_compiler_check_args(), extra_args)
        extra_args = self.unix_link_flags_to_native(extra_args)
        # Append both to the compiler args such that they override them
        args = self._override_args(args, extra_args)
        return self.compile(code, args)

    def links(self, code, env, extra_args=None, dependencies=None):
        with self._links_wrapper(code, env, extra_args, dependencies) as p:
            return p.returncode == 0

    def run(self, code, env, extra_args=None, dependencies=None):
        if self.is_cross and self.exe_wrapper is None:
            raise CrossNoRunException('Can not run test applications in this cross environment.')
        with self._links_wrapper(code, env, extra_args, dependencies) as p:
            if p.returncode != 0:
                mlog.debug('Could not compile test file %s: %d\n' % (
                    p.input_name,
                    p.returncode))
                return RunResult(False)
            if self.is_cross:
                cmdlist = self.exe_wrapper + [p.output_name]
            else:
                cmdlist = p.output_name
            try:
                pe, so, se = Popen_safe(cmdlist)
            except Exception as e:
                mlog.debug('Could not run: %s (error: %s)\n' % (cmdlist, e))
                return RunResult(False)

        mlog.debug('Program stdout:\n')
        mlog.debug(so)
        mlog.debug('Program stderr:\n')
        mlog.debug(se)
        return RunResult(True, pe.returncode, so, se)

    def cross_sizeof(self, element, prefix, env, extra_args=None, dependencies=None):
        if extra_args is None:
            extra_args = []
        element_exists_templ = '''#include <stdio.h>
{0}
int main(int argc, char **argv) {{
    {1} something;
}}
'''
        templ = '''#include <stdio.h>
%s
int temparray[%d-sizeof(%s)];
'''
        if not self.compiles(element_exists_templ.format(prefix, element), env, extra_args, dependencies):
            return -1
        for i in range(1, 1024):
            code = templ % (prefix, i, element)
            if self.compiles(code, env, extra_args, dependencies):
                if self.id == 'msvc':
                    # MSVC refuses to construct an array of zero size, so
                    # the test only succeeds when i is sizeof(element) + 1
                    return i - 1
                return i
        raise EnvironmentException('Cross checking sizeof overflowed.')

    def sizeof(self, element, prefix, env, extra_args=None, dependencies=None):
        if extra_args is None:
            extra_args = []
        if self.is_cross:
            return self.cross_sizeof(element, prefix, env, extra_args, dependencies)
        templ = '''#include<stdio.h>
%s

int main(int argc, char **argv) {
    printf("%%ld\\n", (long)(sizeof(%s)));
    return 0;
};
'''
        res = self.run(templ % (prefix, element), env, extra_args, dependencies)
        if not res.compiled:
            return -1
        if res.returncode != 0:
            raise EnvironmentException('Could not run sizeof test binary.')
        return int(res.stdout)

    def cross_alignment(self, typename, env, extra_args=None, dependencies=None):
        if extra_args is None:
            extra_args = []
        type_exists_templ = '''#include <stdio.h>
int main(int argc, char **argv) {{
    {0} something;
}}
'''
        templ = '''#include<stddef.h>
struct tmp {
  char c;
  %s target;
};

int testarray[%d-offsetof(struct tmp, target)];
'''
        if not self.compiles(type_exists_templ.format(typename), env, extra_args, dependencies):
            return -1
        for i in range(1, 1024):
            code = templ % (typename, i)
            if self.compiles(code, env, extra_args, dependencies):
                if self.id == 'msvc':
                    # MSVC refuses to construct an array of zero size, so
                    # the test only succeeds when i is sizeof(element) + 1
                    return i - 1
                return i
        raise EnvironmentException('Cross checking offsetof overflowed.')

    def alignment(self, typename, env, extra_args=None, dependencies=None):
        if extra_args is None:
            extra_args = []
        if self.is_cross:
            return self.cross_alignment(typename, env, extra_args, dependencies)
        templ = '''#include<stdio.h>
#include<stddef.h>

struct tmp {
  char c;
  %s target;
};

int main(int argc, char **argv) {
  printf("%%d", (int)offsetof(struct tmp, target));
  return 0;
}
'''
        res = self.run(templ % typename, env, extra_args, dependencies)
        if not res.compiled:
            raise EnvironmentException('Could not compile alignment test.')
        if res.returncode != 0:
            raise EnvironmentException('Could not run alignment test binary.')
        align = int(res.stdout)
        if align == 0:
            raise EnvironmentException('Could not determine alignment of %s. Sorry. You might want to file a bug.' % typename)
        return align

    @staticmethod
    def _no_prototype_templ():
        """
        Try to find the function without a prototype from a header by defining
        our own dummy prototype and trying to link with the C library (and
        whatever else the compiler links in by default). This is very similar
        to the check performed by Autoconf for AC_CHECK_FUNCS.
        """
        # Define the symbol to something else since it is defined by the
        # includes or defines listed by the user (prefix -> {0}) or by the
        # compiler. Then, undef the symbol to get rid of it completely.
        head = '''
        #define {1} meson_disable_define_of_{1}
        #include <limits.h>
        {0}
        #undef {1}
        '''
        # Override any GCC internal prototype and declare our own definition for
        # the symbol. Use char because that's unlikely to be an actual return
        # value for a function which ensures that we override the definition.
        head += '''
        #ifdef __cplusplus
        extern "C"
        #endif
        char {1} ();
        '''
        # The actual function call
        main = '''
        int main ()
        {{
          return {1} ();
        }}'''
        return head, main

    @staticmethod
    def _have_prototype_templ():
        """
        Returns a head-er and main() call that uses the headers listed by the
        user for the function prototype while checking if a function exists.
        """
        # Add the 'prefix', aka defines, includes, etc that the user provides
        head = '#include <limits.h>\n{0}\n'
        # We don't know what the function takes or returns, so return it as an int.
        # Just taking the address or comparing it to void is not enough because
        # compilers are smart enough to optimize it away. The resulting binary
        # is not run so we don't care what the return value is.
        main = '\nint main() {{ void *a = (void*) &{1}; long b = (long) a; return (int) b; }}'
        return head, main

    def has_function(self, funcname, prefix, env, extra_args=None, dependencies=None):
        """
        First, this function looks for the symbol in the default libraries
        provided by the compiler (stdlib + a few others usually). If that
        fails, it checks if any of the headers specified in the prefix provide
        an implementation of the function, and if that fails, it checks if it's
        implemented as a compiler-builtin.
        """
        if extra_args is None:
            extra_args = []

        # Short-circuit if the check is already provided by the cross-info file
        varname = 'has function ' + funcname
        varname = varname.replace(' ', '_')
        if self.is_cross:
            val = env.cross_info.config['properties'].get(varname, None)
            if val is not None:
                if isinstance(val, bool):
                    return val
                raise EnvironmentException('Cross variable {0} is not a boolean.'.format(varname))

        # glibc defines functions that are not available on Linux as stubs that
        # fail with ENOSYS (such as e.g. lchmod). In this case we want to fail
        # instead of detecting the stub as a valid symbol.
        # We already included limits.h earlier to ensure that these are defined
        # for stub functions.
        stubs_fail = '''
        #if defined __stub_{1} || defined __stub___{1}
        fail fail fail this function is not going to work
        #endif
        '''

        # If we have any includes in the prefix supplied by the user, assume
        # that the user wants us to use the symbol prototype defined in those
        # includes. If not, then try to do the Autoconf-style check with
        # a dummy prototype definition of our own.
        # This is needed when the linker determines symbol availability from an
        # SDK based on the prototype in the header provided by the SDK.
        # Ignoring this prototype would result in the symbol always being
        # marked as available.
        if '#include' in prefix:
            head, main = self._have_prototype_templ()
        else:
            head, main = self._no_prototype_templ()
        templ = head + stubs_fail + main

        if self.links(templ.format(prefix, funcname), env, extra_args, dependencies):
            return True
        # Some functions like alloca() are defined as compiler built-ins which
        # are inlined by the compiler, so look for __builtin_symbol in the libc
        # if there's no #include-s in prefix which would've #define-d the
        # symbol correctly. If there is a #include, just check for the symbol
        # directly. This is needed because the above #undef fancy footwork
        # doesn't work for builtins.
        # This fixes instances such as #1083 where MSYS2 defines
        # __builtin_posix_memalign in the C library but doesn't define
        # posix_memalign in the headers to point to that builtin which results
        # in an invalid detection.
        if '#include' not in prefix:
            code = 'int main() {{ {0}; }}'
            return self.links(code.format('__builtin_' + funcname), env,
                              extra_args, dependencies)
        else:
            code = '{0}\n' + stubs_fail + '\nint main() {{ {1}; }}'
            return self.links(code.format(prefix, funcname), env, extra_args,
                              dependencies)

    def has_members(self, typename, membernames, prefix, env, extra_args=None, dependencies=None):
        if extra_args is None:
            extra_args = []
        templ = '''{0}
void bar() {{
    {1} {2};
    {3}
}};
'''
        # Create code that accesses all members
        members = ''
        for m in membernames:
            members += 'foo.{};\n'.format(m)
        code = templ.format(prefix, typename, 'foo', members)
        return self.compiles(code, env, extra_args, dependencies)

    def has_type(self, typename, prefix, env, extra_args, dependencies=None):
        templ = '''%s
void bar() {
    sizeof(%s);
};
'''
        return self.compiles(templ % (prefix, typename), env, extra_args, dependencies)

    def symbols_have_underscore_prefix(self, env):
        '''
        Check if the compiler prefixes an underscore to global C symbols
        '''
        symbol_name = b'meson_uscore_prefix'
        code = '''#ifdef __cplusplus
        extern "C" {
        #endif
        void ''' + symbol_name.decode() + ''' () {}
        #ifdef __cplusplus
        }
        #endif
        '''
        args = self.get_cross_extra_flags(env, compile=True, link=False)
        args += self.get_compiler_check_args()
        n = 'symbols_have_underscore_prefix'
        with self.compile(code, args, 'compile') as p:
            if p.returncode != 0:
                m = 'BUG: Unable to compile {!r} check: {}'
                raise RuntimeError(m.format(n, p.stdo))
            if not os.path.isfile(p.output_name):
                m = 'BUG: Can\'t find compiled test code for {!r} check'
                raise RuntimeError(m.format(n))
            with open(p.output_name, 'rb') as o:
                for line in o:
                    # Check if the underscore form of the symbol is somewhere
                    # in the output file.
                    if b'_' + symbol_name in line:
                        return True
                    # Else, check if the non-underscored form is present
                    elif symbol_name in line:
                        return False
        raise RuntimeError('BUG: {!r} check failed unexpectedly'.format(n))

    def find_library(self, libname, env, extra_dirs):
        # First try if we can just add the library as -l.
        code = '''int main(int argc, char **argv) {
    return 0;
}
        '''
        if extra_dirs and isinstance(extra_dirs, str):
            extra_dirs = [extra_dirs]
        # Gcc + co seem to prefer builtin lib dirs to -L dirs.
        # Only try to find std libs if no extra dirs specified.
        if len(extra_dirs) == 0:
            args = ['-l' + libname]
            if self.links(code, env, extra_args=args):
                return args
        # Not found? Try to find the library file itself.
        extra_dirs += self.get_library_dirs()
        suffixes = ['so', 'dylib', 'lib', 'dll', 'a']
        for d in extra_dirs:
            for suffix in suffixes:
                trial = os.path.join(d, 'lib' + libname + '.' + suffix)
                if os.path.isfile(trial):
                    return trial
                trial2 = os.path.join(d, libname + '.' + suffix)
                if os.path.isfile(trial2):
                    return trial2
        return None

    def thread_flags(self):
        return ['-pthread']

    def thread_link_flags(self):
        return ['-pthread']

    def has_multi_arguments(self, args, env):
        return self.compiles('int i;\n', env, extra_args=args)

class CPPCompiler(CCompiler):
    def __init__(self, exelist, version, is_cross, exe_wrap):
        # If a child ObjCPP class has already set it, don't set it ourselves
        if not hasattr(self, 'language'):
            self.language = 'cpp'
        CCompiler.__init__(self, exelist, version, is_cross, exe_wrap)

    def sanity_check(self, work_dir, environment):
        code = 'class breakCCompiler;int main(int argc, char **argv) { return 0; }\n'
        return self.sanity_check_impl(work_dir, environment, 'sanitycheckcpp.cc', code)

    def has_header_symbol(self, hname, symbol, prefix, env, extra_args=None, dependencies=None):
        # Check if it's a C-like symbol
        if super().has_header_symbol(hname, symbol, prefix, env, extra_args, dependencies):
            return True
        # Check if it's a class or a template
        if extra_args is None:
            extra_args = []
        templ = '''{2}
#include <{0}>
using {1};
int main () {{ return 0; }}'''
        return self.compiles(templ.format(hname, symbol, prefix), env,
                             extra_args, dependencies)

class ObjCCompiler(CCompiler):
    def __init__(self, exelist, version, is_cross, exe_wrap):
        self.language = 'objc'
        CCompiler.__init__(self, exelist, version, is_cross, exe_wrap)

    def sanity_check(self, work_dir, environment):
        # TODO try to use sanity_check_impl instead of duplicated code
        source_name = os.path.join(work_dir, 'sanitycheckobjc.m')
        binary_name = os.path.join(work_dir, 'sanitycheckobjc')
        extra_flags = self.get_cross_extra_flags(environment, compile=True, link=False)
        if self.is_cross:
            extra_flags += self.get_compile_only_args()
        with open(source_name, 'w') as ofile:
            ofile.write('#import<stdio.h>\n'
                        'int main(int argc, char **argv) { return 0; }\n')
        pc = subprocess.Popen(self.exelist + extra_flags + [source_name, '-o', binary_name])
        pc.wait()
        if pc.returncode != 0:
            raise EnvironmentException('ObjC compiler %s can not compile programs.' % self.name_string())
        if self.is_cross:
            # Can't check if the binaries run so we have to assume they do
            return
        pe = subprocess.Popen(binary_name)
        pe.wait()
        if pe.returncode != 0:
            raise EnvironmentException('Executables created by ObjC compiler %s are not runnable.' % self.name_string())

class ObjCPPCompiler(CPPCompiler):
    def __init__(self, exelist, version, is_cross, exe_wrap):
        self.language = 'objcpp'
        CPPCompiler.__init__(self, exelist, version, is_cross, exe_wrap)

    def sanity_check(self, work_dir, environment):
        # TODO try to use sanity_check_impl instead of duplicated code
        source_name = os.path.join(work_dir, 'sanitycheckobjcpp.mm')
        binary_name = os.path.join(work_dir, 'sanitycheckobjcpp')
        extra_flags = self.get_cross_extra_flags(environment, compile=True, link=False)
        if self.is_cross:
            extra_flags += self.get_compile_only_args()
        with open(source_name, 'w') as ofile:
            ofile.write('#import<stdio.h>\n'
                        'class MyClass;'
                        'int main(int argc, char **argv) { return 0; }\n')
        pc = subprocess.Popen(self.exelist + extra_flags + [source_name, '-o', binary_name])
        pc.wait()
        if pc.returncode != 0:
            raise EnvironmentException('ObjC++ compiler %s can not compile programs.' % self.name_string())
        if self.is_cross:
            # Can't check if the binaries run so we have to assume they do
            return
        pe = subprocess.Popen(binary_name)
        pe.wait()
        if pe.returncode != 0:
            raise EnvironmentException('Executables created by ObjC++ compiler %s are not runnable.' % self.name_string())

class MonoCompiler(Compiler):
    def __init__(self, exelist, version):
        self.language = 'cs'
        super().__init__(exelist, version)
        self.id = 'mono'
        self.monorunner = 'mono'

    def get_output_args(self, fname):
        return ['-out:' + fname]

    def get_link_args(self, fname):
        return ['-r:' + fname]

    def get_soname_args(self, prefix, shlib_name, suffix, path, soversion, is_shared_module):
        return []

    def get_werror_args(self):
        return ['-warnaserror']

    def split_shlib_to_parts(self, fname):
        return (None, fname)

    def build_rpath_args(self, build_dir, rpath_paths, install_rpath):
        return []

    def get_dependency_gen_args(self, outtarget, outfile):
        return []

    def get_linker_exelist(self):
        return self.exelist[:]

    def get_compile_only_args(self):
        return []

    def get_linker_output_args(self, outputname):
        return []

    def get_coverage_args(self):
        return []

    def get_coverage_link_args(self):
        return []

    def get_std_exe_link_args(self):
        return []

    def get_include_args(self, path):
        return []

    def get_pic_args(self):
        return []

    def name_string(self):
        return ' '.join(self.exelist)

    def get_pch_use_args(self, pch_dir, header):
        return []

    def get_pch_name(self, header_name):
        return ''

    def sanity_check(self, work_dir, environment):
        src = 'sanity.cs'
        obj = 'sanity.exe'
        source_name = os.path.join(work_dir, src)
        with open(source_name, 'w') as ofile:
            ofile.write('''public class Sanity {
    static public void Main () {
    }
}
''')
        pc = subprocess.Popen(self.exelist + [src], cwd=work_dir)
        pc.wait()
        if pc.returncode != 0:
            raise EnvironmentException('Mono compiler %s can not compile programs.' % self.name_string())
        cmdlist = [self.monorunner, obj]
        pe = subprocess.Popen(cmdlist, cwd=work_dir)
        pe.wait()
        if pe.returncode != 0:
            raise EnvironmentException('Executables created by Mono compiler %s are not runnable.' % self.name_string())

    def needs_static_linker(self):
        return False

    def get_buildtype_args(self, buildtype):
        return mono_buildtype_args[buildtype]

class JavaCompiler(Compiler):
    def __init__(self, exelist, version):
        self.language = 'java'
        super().__init__(exelist, version)
        self.id = 'unknown'
        self.javarunner = 'java'

    def get_soname_args(self, prefix, shlib_name, suffix, path, soversion, is_shared_module):
        return []

    def get_werror_args(self):
        return ['-Werror']

    def split_shlib_to_parts(self, fname):
        return (None, fname)

    def build_rpath_args(self, build_dir, rpath_paths, install_rpath):
        return []

    def get_dependency_gen_args(self, outtarget, outfile):
        return []

    def get_linker_exelist(self):
        return self.exelist[:]

    def get_compile_only_args(self):
        return []

    def get_output_args(self, subdir):
        if subdir == '':
            subdir = './'
        return ['-d', subdir, '-s', subdir]

    def get_linker_output_args(self, outputname):
        return []

    def get_coverage_args(self):
        return []

    def get_coverage_link_args(self):
        return []

    def get_std_exe_link_args(self):
        return []

    def get_include_args(self, path):
        return []

    def get_pic_args(self):
        return []

    def name_string(self):
        return ' '.join(self.exelist)

    def get_pch_use_args(self, pch_dir, header):
        return []

    def get_pch_name(self, header_name):
        return ''

    def get_buildtype_args(self, buildtype):
        return java_buildtype_args[buildtype]

    def sanity_check(self, work_dir, environment):
        src = 'SanityCheck.java'
        obj = 'SanityCheck'
        source_name = os.path.join(work_dir, src)
        with open(source_name, 'w') as ofile:
            ofile.write('''class SanityCheck {
  public static void main(String[] args) {
    int i;
  }
}
''')
        pc = subprocess.Popen(self.exelist + [src], cwd=work_dir)
        pc.wait()
        if pc.returncode != 0:
            raise EnvironmentException('Java compiler %s can not compile programs.' % self.name_string())
        runner = shutil.which(self.javarunner)
        if runner:
            cmdlist = [runner, obj]
            pe = subprocess.Popen(cmdlist, cwd=work_dir)
            pe.wait()
            if pe.returncode != 0:
                raise EnvironmentException('Executables created by Java compiler %s are not runnable.' % self.name_string())
        else:
            m = "Java Virtual Machine wasn't found, but it's needed by Meson. " \
                "Please install a JRE.\nIf you have specific needs where this " \
                "requirement doesn't make sense, please open a bug at " \
                "https://github.com/mesonbuild/meson/issues/new and tell us " \
                "all about it."
            raise EnvironmentException(m)

    def needs_static_linker(self):
        return False

class ValaCompiler(Compiler):
    def __init__(self, exelist, version):
        self.language = 'vala'
        super().__init__(exelist, version)
        self.version = version
        self.id = 'valac'
        self.is_cross = False

    def name_string(self):
        return ' '.join(self.exelist)

    def needs_static_linker(self):
        return False # Because compiles into C.

    def get_output_args(self, target):
        return ['-o', target]

    def get_compile_only_args(self):
        return ['-C']

    def get_werror_args(self):
        return ['--fatal-warnings']

    def sanity_check(self, work_dir, environment):
        code = 'class MesonSanityCheck : Object { }'
        args = self.get_cross_extra_flags(environment, compile=True, link=False)
        with self.compile(code, args, 'compile') as p:
            if p.returncode != 0:
                msg = 'Vala compiler {!r} can not compile programs' \
                      ''.format(self.name_string())
                raise EnvironmentException(msg)

    def get_buildtype_args(self, buildtype):
        if buildtype == 'debug' or buildtype == 'debugoptimized' or buildtype == 'minsize':
            return ['--debug']
        return []

    def find_library(self, libname, env, extra_dirs):
        if extra_dirs and isinstance(extra_dirs, str):
            extra_dirs = [extra_dirs]
        # Valac always looks in the default vapi dir, so only search there if
        # no extra dirs are specified.
        if len(extra_dirs) == 0:
            code = 'class MesonFindLibrary : Object { }'
            vapi_args = ['--pkg', libname]
            args = self.get_cross_extra_flags(env, compile=True, link=False)
            args += vapi_args
            with self.compile(code, args, 'compile') as p:
                if p.returncode == 0:
                    return vapi_args
        # Not found? Try to find the vapi file itself.
        for d in extra_dirs:
            vapi = os.path.join(d, libname + '.vapi')
            if os.path.isfile(vapi):
                return vapi
        mlog.debug('Searched {!r} and {!r} wasn\'t found'.format(extra_dirs, libname))
        return None

class RustCompiler(Compiler):
    def __init__(self, exelist, version):
        self.language = 'rust'
        super().__init__(exelist, version)
        self.id = 'rustc'

    def needs_static_linker(self):
        return False

    def name_string(self):
        return ' '.join(self.exelist)

    def sanity_check(self, work_dir, environment):
        source_name = os.path.join(work_dir, 'sanity.rs')
        output_name = os.path.join(work_dir, 'rusttest')
        with open(source_name, 'w') as ofile:
            ofile.write('''fn main() {
}
''')
        pc = subprocess.Popen(self.exelist + ['-o', output_name, source_name], cwd=work_dir)
        pc.wait()
        if pc.returncode != 0:
            raise EnvironmentException('Rust compiler %s can not compile programs.' % self.name_string())
        if subprocess.call(output_name) != 0:
            raise EnvironmentException('Executables created by Rust compiler %s are not runnable.' % self.name_string())

    def get_dependency_gen_args(self, outfile):
        return ['--dep-info', outfile]

    def get_buildtype_args(self, buildtype):
        return rust_buildtype_args[buildtype]

class SwiftCompiler(Compiler):
    def __init__(self, exelist, version):
        self.language = 'swift'
        super().__init__(exelist, version)
        self.version = version
        self.id = 'llvm'
        self.is_cross = False

    def get_linker_exelist(self):
        return self.exelist[:]

    def name_string(self):
        return ' '.join(self.exelist)

    def needs_static_linker(self):
        return True

    def get_werror_args(self):
        return ['--fatal-warnings']

    def get_dependency_gen_args(self, outtarget, outfile):
        return ['-emit-dependencies']

    def depfile_for_object(self, objfile):
        return os.path.splitext(objfile)[0] + '.' + self.get_depfile_suffix()

    def get_depfile_suffix(self):
        return 'd'

    def get_output_args(self, target):
        return ['-o', target]

    def get_linker_output_args(self, target):
        return ['-o', target]

    def get_header_import_args(self, headername):
        return ['-import-objc-header', headername]

    def get_warn_args(self, level):
        return []

    def get_buildtype_args(self, buildtype):
        return swift_buildtype_args[buildtype]

    def get_buildtype_linker_args(self, buildtype):
        return []

    def get_std_exe_link_args(self):
        return ['-emit-executable']

    def get_module_args(self, modname):
        return ['-module-name', modname]

    def get_mod_gen_args(self):
        return ['-emit-module']

    def build_rpath_args(self, *args):
        return [] # FIXME

    def get_include_args(self, dirname):
        return ['-I' + dirname]

    def get_compile_only_args(self):
        return ['-c']

    def sanity_check(self, work_dir, environment):
        src = 'swifttest.swift'
        source_name = os.path.join(work_dir, src)
        output_name = os.path.join(work_dir, 'swifttest')
        with open(source_name, 'w') as ofile:
            ofile.write('''1 + 2
''')
        extra_flags = self.get_cross_extra_flags(environment, compile=True, link=True)
        pc = subprocess.Popen(self.exelist + extra_flags + ['-emit-executable', '-o', output_name, src], cwd=work_dir)
        pc.wait()
        if pc.returncode != 0:
            raise EnvironmentException('Swift compiler %s can not compile programs.' % self.name_string())
        if subprocess.call(output_name) != 0:
            raise EnvironmentException('Executables created by Swift compiler %s are not runnable.' % self.name_string())

class DCompiler(Compiler):
    def __init__(self, exelist, version, is_cross):
        self.language = 'd'
        super().__init__(exelist, version)
        self.id = 'unknown'
        self.is_cross = is_cross

    def sanity_check(self, work_dir, environment):
        source_name = os.path.join(work_dir, 'sanity.d')
        output_name = os.path.join(work_dir, 'dtest')
        with open(source_name, 'w') as ofile:
            ofile.write('''void main() {
}
''')
        pc = subprocess.Popen(self.exelist + self.get_output_args(output_name) + [source_name], cwd=work_dir)
        pc.wait()
        if pc.returncode != 0:
            raise EnvironmentException('D compiler %s can not compile programs.' % self.name_string())
        if subprocess.call(output_name) != 0:
            raise EnvironmentException('Executables created by D compiler %s are not runnable.' % self.name_string())

    def needs_static_linker(self):
        return True

    def name_string(self):
        return ' '.join(self.exelist)

    def get_linker_exelist(self):
        return self.exelist[:]

    def get_preprocess_only_args(self):
        return ['-E']

    def get_compile_only_args(self):
        return ['-c']

    def depfile_for_object(self, objfile):
        return objfile + '.' + self.get_depfile_suffix()

    def get_depfile_suffix(self):
        return 'dep'

    def get_pic_args(self):
        return ['-fPIC']

    def get_std_shared_lib_link_args(self):
        return ['-shared']

    def get_soname_args(self, prefix, shlib_name, suffix, path, soversion, is_shared_module):
        # FIXME: Make this work for Windows, MacOS and cross-compiling
        return get_gcc_soname_args(GCC_STANDARD, prefix, shlib_name, suffix, path, soversion, is_shared_module)

    def get_unittest_args(self):
        return ['-unittest']

    def get_buildtype_linker_args(self, buildtype):
        return []

    def get_std_exe_link_args(self):
        return []

    def build_rpath_args(self, build_dir, rpath_paths, install_rpath):
        # This method is to be used by LDC and DMD.
        # GDC can deal with the verbatim flags.
        if len(rpath_paths) == 0 and len(install_rpath) == 0:
            return []
        paths = ':'.join([os.path.join(build_dir, p) for p in rpath_paths])
        if len(paths) < len(install_rpath):
            padding = 'X' * (len(install_rpath) - len(paths))
            if len(paths) == 0:
                paths = padding
            else:
                paths = paths + ':' + padding
        return ['-L-rpath={}'.format(paths)]

    def translate_args_to_nongnu(self, args):
        dcargs = []
        # Translate common arguments to flags the LDC/DMD compilers
        # can understand.
        # The flags might have been added by pkg-config files,
        # and are therefore out of the user's control.
        for arg in args:
            if arg == '-pthread':
                continue
            if arg.startswith('-Wl,'):
                linkargs = arg[arg.index(',') + 1:].split(',')
                for la in linkargs:
                    dcargs.append('-L' + la.strip())
                continue
            elif arg.startswith('-l'):
                # translate library link flag
                dcargs.append('-L' + arg)
                continue
            dcargs.append(arg)

        return dcargs

class GnuDCompiler(DCompiler):
    def __init__(self, exelist, version, is_cross):
        DCompiler.__init__(self, exelist, version, is_cross)
        self.id = 'gcc'
        self.warn_args = {'1': ['-Wall', '-Wdeprecated'],
                          '2': ['-Wall', '-Wextra', '-Wdeprecated'],
                          '3': ['-Wall', '-Wextra', '-Wdeprecated', '-Wpedantic']}
        self.base_options = ['b_colorout', 'b_sanitize', 'b_staticpic']

    def get_colorout_args(self, colortype):
        if mesonlib.version_compare(self.version, '>=4.9.0'):
            return gnu_color_args[colortype][:]
        return []

    def get_dependency_gen_args(self, outtarget, outfile):
        return ['-fmake-deps=' + outfile]

    def get_output_args(self, target):
        return ['-o', target]

    def get_linker_output_args(self, target):
        return ['-o', target]

    def get_include_args(self, path, is_system):
        return ['-I' + path]

    def get_warn_args(self, level):
        return self.warn_args[level]

    def get_werror_args(self):
        return ['-Werror']

    def get_linker_search_args(self, dirname):
        return ['-L' + dirname]

    def get_buildtype_args(self, buildtype):
        return d_gdc_buildtype_args[buildtype]

    def build_rpath_args(self, build_dir, rpath_paths, install_rpath):
        return build_unix_rpath_args(build_dir, rpath_paths, install_rpath)

    def get_unittest_args(self):
        return ['-funittest']

class LLVMDCompiler(DCompiler):
    def __init__(self, exelist, version, is_cross):
        DCompiler.__init__(self, exelist, version, is_cross)
        self.id = 'llvm'
        self.base_options = ['b_coverage', 'b_colorout']

    def get_colorout_args(self, colortype):
        if colortype == 'always':
            return ['-enable-color']
        return []

    def get_dependency_gen_args(self, outtarget, outfile):
        # LDC using the -deps flag returns a non-Makefile dependency-info file, which
        # the backends can not use. So we disable this feature for now.
        return []

    def get_output_args(self, target):
        return ['-of', target]

    def get_linker_output_args(self, target):
        return ['-of', target]

    def get_include_args(self, path, is_system):
        return ['-I' + path]

    def get_warn_args(self, level):
        if level == '2' or level == '3':
            return ['-wi', '-dw']
        else:
            return ['-wi']

    def get_werror_args(self):
        return ['-w']

    def get_coverage_args(self):
        return ['-cov']

    def get_buildtype_args(self, buildtype):
        return d_ldc_buildtype_args[buildtype]

    def get_pic_args(self):
        return ['-relocation-model=pic']

    def get_linker_search_args(self, dirname):
        # -L is recognized as "add this to the search path" by the linker,
        # while the compiler recognizes it as "pass to linker". So, the first
        # -L is for the compiler, telling it to pass the second -L to the linker.
        return ['-L-L' + dirname]

    def unix_link_flags_to_native(self, args):
        return self.translate_args_to_nongnu(args)

    def unix_compile_flags_to_native(self, args):
        return self.translate_args_to_nongnu(args)

class DmdDCompiler(DCompiler):
    def __init__(self, exelist, version, is_cross):
        DCompiler.__init__(self, exelist, version, is_cross)
        self.id = 'dmd'
        self.base_options = ['b_coverage', 'b_colorout']

    def get_colorout_args(self, colortype):
        if colortype == 'always':
            return ['-color=on']
        return []

    def get_dependency_gen_args(self, outtarget, outfile):
        # LDC using the -deps flag returns a non-Makefile dependency-info file, which
        # the backends can not use. So we disable this feature for now.
        return []

    def get_output_args(self, target):
        return ['-of' + target]

    def get_werror_args(self):
        return ['-w']

    def get_linker_output_args(self, target):
        return ['-of' + target]

    def get_include_args(self, path, is_system):
        return ['-I' + path]

    def get_warn_args(self, level):
        return ['-wi']

    def get_coverage_args(self):
        return ['-cov']

    def get_linker_search_args(self, dirname):
        # -L is recognized as "add this to the search path" by the linker,
        # while the compiler recognizes it as "pass to linker". So, the first
        # -L is for the compiler, telling it to pass the second -L to the linker.
        return ['-L-L' + dirname]

    def get_buildtype_args(self, buildtype):
        return d_dmd_buildtype_args[buildtype]

    def get_std_shared_lib_link_args(self):
        return ['-shared', '-defaultlib=libphobos2.so']

    def unix_link_flags_to_native(self, args):
        return self.translate_args_to_nongnu(args)

    def unix_compile_flags_to_native(self, args):
        return self.translate_args_to_nongnu(args)

class VisualStudioCCompiler(CCompiler):
    std_warn_args = ['/W3']
    std_opt_args = ['/O2']

    def __init__(self, exelist, version, is_cross, exe_wrap):
        CCompiler.__init__(self, exelist, version, is_cross, exe_wrap)
        self.id = 'msvc'
        # /showIncludes is needed for build dependency tracking in Ninja
        # See: https://ninja-build.org/manual.html#_deps
        self.always_args = ['/nologo', '/showIncludes']
        self.warn_args = {'1': ['/W2'],
                          '2': ['/W3'],
                          '3': ['/W4']}
        self.base_options = ['b_pch'] # FIXME add lto, pgo and the like

    def get_always_args(self):
        return self.always_args

    def get_linker_debug_crt_args(self):
        """
        Arguments needed to select a debug crt for the linker

        Sometimes we need to manually select the CRT (C runtime) to use with
        MSVC. One example is when trying to link with static libraries since
        MSVC won't auto-select a CRT for us in that case and will error out
        asking us to select one.
        """
        return ['/MDd']

    def get_buildtype_args(self, buildtype):
        return msvc_buildtype_args[buildtype]

    def get_buildtype_linker_args(self, buildtype):
        return msvc_buildtype_linker_args[buildtype]

    def get_pch_suffix(self):
        return 'pch'

    def get_pch_name(self, header):
        chopped = os.path.split(header)[-1].split('.')[:-1]
        chopped.append(self.get_pch_suffix())
        pchname = '.'.join(chopped)
        return pchname

    def get_pch_use_args(self, pch_dir, header):
        base = os.path.split(header)[-1]
        pchname = self.get_pch_name(header)
        return ['/FI' + base, '/Yu' + base, '/Fp' + os.path.join(pch_dir, pchname)]

    def get_preprocess_only_args(self):
        return ['/E']

    def get_compile_only_args(self):
        return ['/c']

    def get_no_optimization_args(self):
        return ['/Od']

    def get_output_args(self, target):
        if target.endswith('.exe'):
            return ['/Fe' + target]
        return ['/Fo' + target]

    def get_dependency_gen_args(self, outtarget, outfile):
        return []

    def get_linker_exelist(self):
        return ['link'] # FIXME, should have same path as compiler.

    def get_linker_always_args(self):
        return ['/nologo']

    def get_linker_output_args(self, outputname):
        return ['/OUT:' + outputname]

    def get_linker_search_args(self, dirname):
        return ['/LIBPATH:' + dirname]

    def get_pic_args(self):
        return [] # PIC is handled by the loader on Windows

    def get_std_shared_lib_link_args(self):
        return ['/DLL']

    def gen_vs_module_defs_args(self, defsfile):
        if not isinstance(defsfile, str):
            raise RuntimeError('Module definitions file should be str')
        # With MSVC, DLLs only export symbols that are explicitly exported,
        # so if a module defs file is specified, we use that to export symbols
        return ['/DEF:' + defsfile]

    def gen_pch_args(self, header, source, pchname):
        objname = os.path.splitext(pchname)[0] + '.obj'
        return (objname, ['/Yc' + header, '/Fp' + pchname, '/Fo' + objname ])

    def gen_import_library_args(self, implibname):
        "The name of the outputted import library"
        return ['/IMPLIB:' + implibname]

    def build_rpath_args(self, build_dir, rpath_paths, install_rpath):
        return []

    # FIXME, no idea what these should be.
    def thread_flags(self):
        return []

    def thread_link_flags(self):
        return []

    def get_options(self):
        return {'c_winlibs': coredata.UserStringArrayOption('c_winlibs',
                                                            'Windows libs to link against.',
                                                            msvc_winlibs)
                }

    def get_option_link_args(self, options):
        return options['c_winlibs'].value[:]

    def unix_link_flags_to_native(self, args):
        result = []
        for i in args:
            if i.startswith('-L'):
                i = '/LIBPATH:' + i[2:]
            # Translate GNU-style -lfoo library name to the import library
            elif i.startswith('-l'):
                name = i[2:]
                if name in ('m', 'c', 'pthread'):
                    # With MSVC, these are provided by the C runtime which is
                    # linked in by default
                    continue
                else:
                    i = name + '.lib'
            # -pthread in link flags is only used on Linux
            elif i == '-pthread':
                continue
            result.append(i)
        return result

    def unix_compile_flags_to_native(self, args):
        result = []
        for i in args:
            # -mms-bitfields is specific to MinGW-GCC
            # -pthread is only valid for GCC
            if i in ('-mms-bitfields', '-pthread'):
                continue
            result.append(i)
        return result

    def get_werror_args(self):
        return ['/WX']

    def get_include_args(self, path, is_system):
        if path == '':
            path = '.'
        # msvc does not have a concept of system header dirs.
        return ['-I' + path]

    # Visual Studio is special. It ignores some arguments it does not
    # understand and you can't tell it to error out on those.
    # http://stackoverflow.com/questions/15259720/how-can-i-make-the-microsoft-c-compiler-treat-unknown-flags-as-errors-rather-t
    def has_multi_arguments(self, args, env):
        warning_text = '9002'
        code = 'int i;\n'
        (fd, srcname) = tempfile.mkstemp(suffix='.' + self.default_suffix)
        os.close(fd)
        with open(srcname, 'w') as ofile:
            ofile.write(code)
        # Read c_args/cpp_args/etc from the cross-info file (if needed)
        extra_args = self.get_cross_extra_flags(env, compile=True, link=False)
        extra_args += self.get_compile_only_args()
        commands = self.exelist + args + extra_args + [srcname]
        mlog.debug('Running VS compile:')
        mlog.debug('Command line: ', ' '.join(commands))
        mlog.debug('Code:\n', code)
        p, stdo, stde = Popen_safe(commands, cwd=os.path.split(srcname)[0])
        if p.returncode != 0:
            return False
        return not(warning_text in stde or warning_text in stdo)

    def get_compile_debugfile_args(self, rel_obj, pch=False):
        pdbarr = rel_obj.split('.')[:-1]
        pdbarr += ['pdb']
        args = ['/Fd' + '.'.join(pdbarr)]
        # When generating a PDB file with PCH, all compile commands write
        # to the same PDB file. Hence, we need to serialize the PDB
        # writes using /FS since we do parallel builds. This slows down the
        # build obviously, which is why we only do this when PCH is on.
        # This was added in Visual Studio 2013 (MSVC 18.0). Before that it was
        # always on: https://msdn.microsoft.com/en-us/library/dn502518.aspx
        if pch and mesonlib.version_compare(self.version, '>=18.0'):
            args = ['/FS'] + args
        return args

    def get_link_debugfile_args(self, targetfile):
        pdbarr = targetfile.split('.')[:-1]
        pdbarr += ['pdb']
        return ['/DEBUG', '/PDB:' + '.'.join(pdbarr)]

class VisualStudioCPPCompiler(VisualStudioCCompiler, CPPCompiler):
    def __init__(self, exelist, version, is_cross, exe_wrap):
        self.language = 'cpp'
        CPPCompiler.__init__(self, exelist, version, is_cross, exe_wrap)
        VisualStudioCCompiler.__init__(self, exelist, version, is_cross, exe_wrap)
        self.base_options = ['b_pch'] # FIXME add lto, pgo and the like

    def get_options(self):
        return {'cpp_eh': coredata.UserComboOption('cpp_eh',
                                                   'C++ exception handling type.',
                                                   ['none', 'a', 's', 'sc'],
                                                   'sc'),
                'cpp_winlibs': coredata.UserStringArrayOption('cpp_winlibs',
                                                              'Windows libs to link against.',
                                                              msvc_winlibs)
                }

    def get_option_compile_args(self, options):
        args = []
        std = options['cpp_eh']
        if std.value != 'none':
            args.append('/EH' + std.value)
        return args

    def get_option_link_args(self, options):
        return options['cpp_winlibs'].value[:]

GCC_STANDARD = 0
GCC_OSX = 1
GCC_MINGW = 2

CLANG_STANDARD = 0
CLANG_OSX = 1
CLANG_WIN = 2
# Possibly clang-cl?

def get_gcc_soname_args(gcc_type, prefix, shlib_name, suffix, path, soversion, is_shared_module):
    if soversion is None:
        sostr = ''
    else:
        sostr = '.' + soversion
    if gcc_type == GCC_STANDARD or gcc_type == GCC_MINGW:
        # Might not be correct for mingw but seems to work.
        return ['-Wl,-soname,%s%s.%s%s' % (prefix, shlib_name, suffix, sostr)]
        return ['-Wl,-soname,%s%s' % (shlib_name, sostr)]
    elif gcc_type == GCC_OSX:
        if is_shared_module:
            return []
        return ['-install_name', os.path.join(path, 'lib' + shlib_name + '.dylib')]
    else:
        raise RuntimeError('Not implemented yet.')


class GnuCompiler:
    # Functionality that is common to all GNU family compilers.
    def __init__(self, gcc_type, defines):
        self.id = 'gcc'
        self.gcc_type = gcc_type
        self.defines = defines or {}
        self.base_options = ['b_pch', 'b_lto', 'b_pgo', 'b_sanitize', 'b_coverage',
                             'b_colorout', 'b_ndebug', 'b_staticpic']
        if self.gcc_type != GCC_OSX:
            self.base_options.append('b_lundef')
            self.base_options.append('b_asneeded')
        # All GCC backends can do assembly
        self.can_compile_suffixes.add('s')

    def get_colorout_args(self, colortype):
        if mesonlib.version_compare(self.version, '>=4.9.0'):
            return gnu_color_args[colortype][:]
        return []

    def get_warn_args(self, level):
        args = super().get_warn_args(level)
        if mesonlib.version_compare(self.version, '<4.8.0') and '-Wpedantic' in args:
            # -Wpedantic was added in 4.8.0
            # https://gcc.gnu.org/gcc-4.8/changes.html
            args[args.index('-Wpedantic')] = '-pedantic'
        return args

    def has_define(self, define):
        return define in self.defines

    def get_define(self, define):
        if define in self.defines:
            return self.defines[define]

    def get_pic_args(self):
        if self.gcc_type in (GCC_MINGW, GCC_OSX):
            return [] # On Window and OS X, pic is always on.
        return ['-fPIC']

    def get_buildtype_args(self, buildtype):
        return gnulike_buildtype_args[buildtype]

    def get_buildtype_linker_args(self, buildtype):
        if self.gcc_type == GCC_OSX:
            return apple_buildtype_linker_args[buildtype]
        return gnulike_buildtype_linker_args[buildtype]

    def get_always_args(self):
        return ['-pipe']

    def get_pch_suffix(self):
        return 'gch'

    def split_shlib_to_parts(self, fname):
        return (os.path.split(fname)[0], fname)

    def get_soname_args(self, prefix, shlib_name, suffix, path, soversion, is_shared_module):
        return get_gcc_soname_args(self.gcc_type, prefix, shlib_name, suffix, path, soversion, is_shared_module)

    def get_std_shared_lib_link_args(self):
        if self.gcc_type == GCC_OSX:
            return ['-bundle']
        return ['-shared']

class GnuCCompiler(GnuCompiler, CCompiler):
    def __init__(self, exelist, version, gcc_type, is_cross, exe_wrapper=None, defines=None):
        CCompiler.__init__(self, exelist, version, is_cross, exe_wrapper)
        GnuCompiler.__init__(self, gcc_type, defines)
        self.warn_args = {'1': ['-Wall', '-Winvalid-pch'],
                          '2': ['-Wall', '-Wextra', '-Winvalid-pch'],
                          '3': ['-Wall', '-Wpedantic', '-Wextra', '-Winvalid-pch']}

    def get_options(self):
        opts = {'c_std': coredata.UserComboOption('c_std', 'C language standard to use',
                                                  ['none', 'c89', 'c99', 'c11',
                                                   'gnu89', 'gnu99', 'gnu11'],
                                                  'none')}
        if self.gcc_type == GCC_MINGW:
            opts.update({
                'c_winlibs': coredata.UserStringArrayOption('c_winlibs', 'Standard Win libraries to link against',
                                                            gnu_winlibs),
                })
        return opts

    def get_option_compile_args(self, options):
        args = []
        std = options['c_std']
        if std.value != 'none':
            args.append('-std=' + std.value)
        return args

    def get_option_link_args(self, options):
        if self.gcc_type == GCC_MINGW:
            return options['c_winlibs'].value[:]
        return []

    def get_std_shared_lib_link_args(self):
        return ['-shared']

class GnuCPPCompiler(GnuCompiler, CPPCompiler):

    def __init__(self, exelist, version, gcc_type, is_cross, exe_wrap, defines):
        CPPCompiler.__init__(self, exelist, version, is_cross, exe_wrap)
        GnuCompiler.__init__(self, gcc_type, defines)
        self.warn_args = {'1': ['-Wall', '-Winvalid-pch', '-Wnon-virtual-dtor'],
                          '2': ['-Wall', '-Wextra', '-Winvalid-pch', '-Wnon-virtual-dtor'],
                          '3': ['-Wall', '-Wpedantic', '-Wextra', '-Winvalid-pch', '-Wnon-virtual-dtor']}

    def get_options(self):
        opts = {'cpp_std': coredata.UserComboOption('cpp_std', 'C++ language standard to use',
                                                    ['none', 'c++03', 'c++11', 'c++14', 'c++1z',
                                                     'gnu++03', 'gnu++11', 'gnu++14', 'gnu++1z'],
                                                    'none'),
                'cpp_debugstl': coredata.UserBooleanOption('cpp_debugstl',
                                                           'STL debug mode',
                                                           False)}
        if self.gcc_type == GCC_MINGW:
            opts.update({
                'cpp_winlibs': coredata.UserStringArrayOption('cpp_winlibs', 'Standard Win libraries to link against',
                                                              gnu_winlibs),
                })
        return opts

    def get_option_compile_args(self, options):
        args = []
        std = options['cpp_std']
        if std.value != 'none':
            args.append('-std=' + std.value)
        if options['cpp_debugstl'].value:
            args.append('-D_GLIBCXX_DEBUG=1')
        return args

    def get_option_link_args(self, options):
        if self.gcc_type == GCC_MINGW:
            return options['cpp_winlibs'].value[:]
        return []

    def get_compiler_check_args(self):
        # -fpermissive allows non-conforming code to compile which is necessary
        # for many C++ checks. Particularly, the has_header_symbol check is
        # too strict without this and always fails.
        return self.get_no_optimization_args() + ['-fpermissive']

class GnuObjCCompiler(GnuCompiler, ObjCCompiler):

    def __init__(self, exelist, version, is_cross, exe_wrapper=None, defines=None):
        ObjCCompiler.__init__(self, exelist, version, is_cross, exe_wrapper)
        # Not really correct, but GNU objc is only used on non-OSX non-win. File a bug
        # if this breaks your use case.
        GnuCompiler.__init__(self, GCC_STANDARD, defines)
        self.warn_args = {'1': ['-Wall', '-Winvalid-pch'],
                          '2': ['-Wall', '-Wextra', '-Winvalid-pch'],
                          '3': ['-Wall', '-Wpedantic', '-Wextra', '-Winvalid-pch']}

class GnuObjCPPCompiler(GnuCompiler, ObjCPPCompiler):

    def __init__(self, exelist, version, is_cross, exe_wrapper=None, defines=None):
        ObjCPPCompiler.__init__(self, exelist, version, is_cross, exe_wrapper)
        # Not really correct, but GNU objc is only used on non-OSX non-win. File a bug
        # if this breaks your use case.
        GnuCompiler.__init__(self, GCC_STANDARD, defines)
        self.warn_args = {'1': ['-Wall', '-Winvalid-pch', '-Wnon-virtual-dtor'],
                          '2': ['-Wall', '-Wextra', '-Winvalid-pch', '-Wnon-virtual-dtor'],
                          '3': ['-Wall', '-Wpedantic', '-Wextra', '-Winvalid-pch', '-Wnon-virtual-dtor']}

    def get_compiler_check_args(self):
        # -fpermissive allows non-conforming code to compile which is necessary
        # for many ObjC++ checks. Particularly, the has_header_symbol check is
        # too strict without this and always fails.
        return self.get_no_optimization_args() + ['-fpermissive']

class ClangCompiler():
    def __init__(self, clang_type):
        self.id = 'clang'
        self.clang_type = clang_type
        self.base_options = ['b_pch', 'b_lto', 'b_pgo', 'b_sanitize', 'b_coverage',
                             'b_ndebug', 'b_staticpic']
        if self.clang_type != CLANG_OSX:
            self.base_options.append('b_lundef')
            self.base_options.append('b_asneeded')
        # All Clang backends can do assembly and LLVM IR
        self.can_compile_suffixes.update(['ll', 's'])

    def get_pic_args(self):
        if self.clang_type in (CLANG_WIN, CLANG_OSX):
            return [] # On Window and OS X, pic is always on.
        return ['-fPIC']

    def get_buildtype_args(self, buildtype):
        return gnulike_buildtype_args[buildtype]

    def get_buildtype_linker_args(self, buildtype):
        if self.clang_type == CLANG_OSX:
            return apple_buildtype_linker_args[buildtype]
        return gnulike_buildtype_linker_args[buildtype]

    def get_pch_suffix(self):
        return 'pch'

    def get_pch_use_args(self, pch_dir, header):
        # Workaround for Clang bug http://llvm.org/bugs/show_bug.cgi?id=15136
        # This flag is internal to Clang (or at least not documented on the man page)
        # so it might change semantics at any time.
        return ['-include-pch', os.path.join (pch_dir, self.get_pch_name (header))]

    def get_soname_args(self, prefix, shlib_name, suffix, path, soversion, is_shared_module):
        if self.clang_type == CLANG_STANDARD:
            gcc_type = GCC_STANDARD
        elif self.clang_type == CLANG_OSX:
            gcc_type = GCC_OSX
        elif self.clang_type == CLANG_WIN:
            gcc_type = GCC_MINGW
        else:
            raise MesonException('Unreachable code when converting clang type to gcc type.')
        return get_gcc_soname_args(gcc_type, prefix, shlib_name, suffix, path, soversion, is_shared_module)

    def has_multi_arguments(self, args, env):
        return super().has_multi_arguments(
            ['-Werror=unknown-warning-option'] + args,
            env)

    def has_function(self, funcname, prefix, env, extra_args=None, dependencies=None):
        if extra_args is None:
            extra_args = []
        # Starting with XCode 8, we need to pass this to force linker
        # visibility to obey OS X and iOS minimum version targets with
        # -mmacosx-version-min, -miphoneos-version-min, etc.
        # https://github.com/Homebrew/homebrew-core/issues/3727
        if self.clang_type == CLANG_OSX and version_compare(self.version, '>=8.0'):
            extra_args.append('-Wl,-no_weak_imports')
        return super().has_function(funcname, prefix, env, extra_args, dependencies)

    def get_std_shared_module_link_args(self):
        if self.clang_type == CLANG_OSX:
            return ['-bundle', '-Wl,-undefined,dynamic_lookup']
        return ['-shared']

class ClangCCompiler(ClangCompiler, CCompiler):
    def __init__(self, exelist, version, clang_type, is_cross, exe_wrapper=None):
        CCompiler.__init__(self, exelist, version, is_cross, exe_wrapper)
        ClangCompiler.__init__(self, clang_type)
        self.warn_args = {'1': ['-Wall', '-Winvalid-pch'],
                          '2': ['-Wall', '-Wextra', '-Winvalid-pch'],
                          '3': ['-Wall', '-Wpedantic', '-Wextra', '-Winvalid-pch']}

    def get_options(self):
        return {'c_std': coredata.UserComboOption('c_std', 'C language standard to use',
                                                  ['none', 'c89', 'c99', 'c11',
                                                   'gnu89', 'gnu99', 'gnu11'],
                                                  'none')}

    def get_option_compile_args(self, options):
        args = []
        std = options['c_std']
        if std.value != 'none':
            args.append('-std=' + std.value)
        return args

    def get_option_link_args(self, options):
        return []


class ClangCPPCompiler(ClangCompiler, CPPCompiler):
    def __init__(self, exelist, version, cltype, is_cross, exe_wrapper=None):
        CPPCompiler.__init__(self, exelist, version, is_cross, exe_wrapper)
        ClangCompiler.__init__(self, cltype)
        self.warn_args = {'1': ['-Wall', '-Winvalid-pch', '-Wnon-virtual-dtor'],
                          '2': ['-Wall', '-Wextra', '-Winvalid-pch', '-Wnon-virtual-dtor'],
                          '3': ['-Wall', '-Wpedantic', '-Wextra', '-Winvalid-pch', '-Wnon-virtual-dtor']}

    def get_options(self):
        return {'cpp_std': coredata.UserComboOption('cpp_std', 'C++ language standard to use',
                                                    ['none', 'c++03', 'c++11', 'c++14', 'c++1z',
                                                     'gnu++03', 'gnu++11', 'gnu++14', 'gnu++1z'],
                                                    'none')}

    def get_option_compile_args(self, options):
        args = []
        std = options['cpp_std']
        if std.value != 'none':
            args.append('-std=' + std.value)
        return args

    def get_option_link_args(self, options):
        return []

class ClangObjCCompiler(ClangCompiler, GnuObjCCompiler):
    def __init__(self, exelist, version, cltype, is_cross, exe_wrapper=None):
        GnuObjCCompiler.__init__(self, exelist, version, is_cross, exe_wrapper)
        ClangCompiler.__init__(self, cltype)
        self.base_options = ['b_pch', 'b_lto', 'b_pgo', 'b_sanitize', 'b_coverage']

class ClangObjCPPCompiler(ClangCompiler, GnuObjCPPCompiler):
    def __init__(self, exelist, version, cltype, is_cross, exe_wrapper=None):
        GnuObjCPPCompiler.__init__(self, exelist, version, is_cross, exe_wrapper)
        ClangCompiler.__init__(self, cltype)
        self.base_options = ['b_pch', 'b_lto', 'b_pgo', 'b_sanitize', 'b_coverage']

class FortranCompiler(Compiler):
    def __init__(self, exelist, version, is_cross, exe_wrapper=None):
        self.language = 'fortran'
        super().__init__(exelist, version)
        self.is_cross = is_cross
        self.exe_wrapper = exe_wrapper
        # Not really correct but I don't have Fortran compilers to test with. Sorry.
        self.gcc_type = GCC_STANDARD
        self.id = "IMPLEMENTATION CLASSES MUST SET THIS"

    def name_string(self):
        return ' '.join(self.exelist)

    def get_pic_args(self):
        if self.gcc_type in (GCC_MINGW, GCC_OSX):
            return [] # On Window and OS X, pic is always on.
        return ['-fPIC']

    def get_std_shared_lib_link_args(self):
        return ['-shared']

    def needs_static_linker(self):
        return True

    def sanity_check(self, work_dir, environment):
        source_name = os.path.join(work_dir, 'sanitycheckf.f90')
        binary_name = os.path.join(work_dir, 'sanitycheckf')
        with open(source_name, 'w') as ofile:
            ofile.write('''program prog
     print *, "Fortran compilation is working."
end program prog
''')
        extra_flags = self.get_cross_extra_flags(environment, compile=True, link=True)
        pc = subprocess.Popen(self.exelist + extra_flags + [source_name, '-o', binary_name])
        pc.wait()
        if pc.returncode != 0:
            raise EnvironmentException('Compiler %s can not compile programs.' % self.name_string())
        if self.is_cross:
            if self.exe_wrapper is None:
                # Can't check if the binaries run so we have to assume they do
                return
            cmdlist = self.exe_wrapper + [binary_name]
        else:
            cmdlist = [binary_name]
        pe = subprocess.Popen(cmdlist, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
        pe.wait()
        if pe.returncode != 0:
            raise EnvironmentException('Executables created by Fortran compiler %s are not runnable.' % self.name_string())

    def get_std_warn_args(self, level):
        return FortranCompiler.std_warn_args

    def get_buildtype_args(self, buildtype):
        return gnulike_buildtype_args[buildtype]

    def get_buildtype_linker_args(self, buildtype):
        if mesonlib.is_osx():
            return apple_buildtype_linker_args[buildtype]
        return gnulike_buildtype_linker_args[buildtype]

    def split_shlib_to_parts(self, fname):
        return (os.path.split(fname)[0], fname)

    def get_soname_args(self, prefix, shlib_name, suffix, path, soversion, is_shared_module):
        return get_gcc_soname_args(self.gcc_type, prefix, shlib_name, suffix, path, soversion, is_shared_module)

    def get_dependency_gen_args(self, outtarget, outfile):
        # Disabled until this is fixed:
        # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62162
        # return ['-cpp', '-MMD', '-MQ', outtarget]
        return []

    def get_output_args(self, target):
        return ['-o', target]

    def get_preprocess_only_args(self):
        return ['-E']

    def get_compile_only_args(self):
        return ['-c']

    def get_linker_exelist(self):
        return self.exelist[:]

    def get_linker_output_args(self, outputname):
        return ['-o', outputname]

    def get_include_args(self, path, is_system):
        return ['-I' + path]

    def get_module_outdir_args(self, path):
        return ['-J' + path]

    def depfile_for_object(self, objfile):
        return objfile + '.' + self.get_depfile_suffix()

    def get_depfile_suffix(self):
        return 'd'

    def get_std_exe_link_args(self):
        return []

    def build_rpath_args(self, build_dir, rpath_paths, install_rpath):
        return build_unix_rpath_args(build_dir, rpath_paths, install_rpath)

    def module_name_to_filename(self, module_name):
        return module_name.lower() + '.mod'

    def get_warn_args(self, level):
        return ['-Wall']

    def get_no_warn_args(self):
        return ['-w']


class GnuFortranCompiler(FortranCompiler):
    def __init__(self, exelist, version, gcc_type, is_cross, exe_wrapper=None, defines=None):
        super().__init__(exelist, version, is_cross, exe_wrapper=None)
        self.gcc_type = gcc_type
        self.defines = defines or {}
        self.id = 'gcc'

    def has_define(self, define):
        return define in self.defines

    def get_define(self, define):
        if define in self.defines:
            return self.defines[define]

    def get_always_args(self):
        return ['-pipe']

    def gen_import_library_args(self, implibname):
        """
        The name of the outputted import library

        Used only on Windows
        """
        return ['-Wl,--out-implib=' + implibname]

class G95FortranCompiler(FortranCompiler):
    def __init__(self, exelist, version, is_cross, exe_wrapper=None):
        super().__init__(exelist, version, is_cross, exe_wrapper=None)
        self.id = 'g95'

    def get_module_outdir_args(self, path):
        return ['-fmod=' + path]

    def get_always_args(self):
        return ['-pipe']

    def get_no_warn_args(self):
        # FIXME: Confirm that there's no compiler option to disable all warnings
        return []

    def gen_import_library_args(self, implibname):
        """
        The name of the outputted import library

        Used only on Windows
        """
        return ['-Wl,--out-implib=' + implibname]

class SunFortranCompiler(FortranCompiler):
    def __init__(self, exelist, version, is_cross, exe_wrapper=None):
        super().__init__(exelist, version, is_cross, exe_wrapper=None)
        self.id = 'sun'

    def get_dependency_gen_args(self, outtarget, outfile):
        return ['-fpp']

    def get_always_args(self):
        return []

    def get_warn_args(self):
        return []

    def get_module_outdir_args(self, path):
        return ['-moddir=' + path]

class IntelFortranCompiler(FortranCompiler):
    std_warn_args = ['-warn', 'all']

    def __init__(self, exelist, version, is_cross, exe_wrapper=None):
        self.file_suffixes = ('f', 'f90')
        super().__init__(exelist, version, is_cross, exe_wrapper=None)
        self.id = 'intel'

    def get_module_outdir_args(self, path):
        return ['-module', path]

    def get_warn_args(self, level):
        return IntelFortranCompiler.std_warn_args

class PathScaleFortranCompiler(FortranCompiler):
    std_warn_args = ['-fullwarn']

    def __init__(self, exelist, version, is_cross, exe_wrapper=None):
        super().__init__(exelist, version, is_cross, exe_wrapper=None)
        self.id = 'pathscale'

    def get_module_outdir_args(self, path):
        return ['-module', path]

    def get_std_warn_args(self, level):
        return PathScaleFortranCompiler.std_warn_args

class PGIFortranCompiler(FortranCompiler):
    std_warn_args = ['-Minform=inform']

    def __init__(self, exelist, version, is_cross, exe_wrapper=None):
        super().__init__(exelist, version, is_cross, exe_wrapper=None)
        self.id = 'pgi'

    def get_module_outdir_args(self, path):
        return ['-module', path]

    def get_warn_args(self, level):
        return PGIFortranCompiler.std_warn_args

    def get_no_warn_args(self):
        return ['-silent']


class Open64FortranCompiler(FortranCompiler):
    std_warn_args = ['-fullwarn']

    def __init__(self, exelist, version, is_cross, exe_wrapper=None):
        super().__init__(exelist, version, is_cross, exe_wrapper=None)
        self.id = 'open64'

    def get_module_outdir_args(self, path):
        return ['-module', path]

    def get_warn_args(self, level):
        return Open64FortranCompiler.std_warn_args

class NAGFortranCompiler(FortranCompiler):
    std_warn_args = []

    def __init__(self, exelist, version, is_cross, exe_wrapper=None):
        super().__init__(exelist, version, is_cross, exe_wrapper=None)
        self.id = 'nagfor'

    def get_module_outdir_args(self, path):
        return ['-mdir', path]

    def get_always_args(self):
        return []

    def get_warn_args(self, level):
        return NAGFortranCompiler.std_warn_args


class VisualStudioLinker():
    always_args = ['/NOLOGO']
    def __init__(self, exelist):
        self.exelist = exelist

    def get_exelist(self):
        return self.exelist[:]

    def get_std_link_args(self):
        return []

    def get_buildtype_linker_args(self, buildtype):
        return []

    def get_output_args(self, target):
        return ['/OUT:' + target]

    def get_coverage_link_args(self):
        return []

    def get_always_args(self):
        return VisualStudioLinker.always_args

    def get_linker_always_args(self):
        return VisualStudioLinker.always_args

    def build_rpath_args(self, build_dir, rpath_paths, install_rpath):
        return []

    def thread_link_flags(self):
        return []

    def get_option_link_args(self, options):
        return []

    def unix_link_flags_to_native(self, args):
        return args[:]

    def unix_compile_flags_to_native(self, args):
        return args[:]

    def get_link_debugfile_args(self, targetfile):
        pdbarr = targetfile.split('.')[:-1]
        pdbarr += ['pdb']
        return ['/DEBUG', '/PDB:' + '.'.join(pdbarr)]

class ArLinker():

    def __init__(self, exelist):
        self.exelist = exelist
        self.id = 'ar'
        pc, stdo = Popen_safe(self.exelist + ['-h'])[0:2]
        # Enable deterministic builds if they are available.
        if '[D]' in stdo:
            self.std_args = ['csrD']
        else:
            self.std_args = ['csr']

    def build_rpath_args(self, build_dir, rpath_paths, install_rpath):
        return []

    def get_exelist(self):
        return self.exelist[:]

    def get_std_link_args(self):
        return self.std_args

    def get_output_args(self, target):
        return [target]

    def get_buildtype_linker_args(self, buildtype):
        return []

    def get_linker_always_args(self):
        return []

    def get_coverage_link_args(self):
        return []

    def get_always_args(self):
        return []

    def thread_link_flags(self):
        return []

    def get_option_link_args(self, options):
        return []

    def unix_link_flags_to_native(self, args):
        return args[:]

    def unix_compile_flags_to_native(self, args):
        return args[:]

    def get_link_debugfile_args(self, targetfile):
        return []