build/moz.configure/toolchain.configure
author Makoto Kato <m_kato@ga2.so-net.ne.jp>
Mon, 08 May 2017 15:31:44 +0900
branchSEAMONKEY_2_49_ESR_RELBRANCH
changeset 357483 6110ea38bcee80c8089137bb6ea23cc3ecdd5cc3
parent 357481 76d781cfe6ea057c5042c6ed959cecec8ee59fe1
child 357485 e2c27d4e1f71d49db9c4940cf2b3451e8b17a853
permissions -rw-r--r--
Bug 1362872 - Use mbcs encoding for vswhere output. r=gps, a=IanN CLOSED TREE DONTBUILD mozilla-esr52 SEAMONKEY_2_49_ESR_RELBRANCH We add vswhere.exe to support VS2017. But the description output of this command is localized, so it causes UnicodeDecodeError. So we should use 'mbcs' encoding for this output on Windows platform. And for minor languages, we should also use replace to avoid decode error. test_toolchain_configure.py calls vc_compiler_path without correct host.kernel, so we should check current python platform.

# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
# vim: set filetype=python:
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

# PGO
# ==============================================================
option(env='MOZ_PGO', help='Build with profile guided optimizations')

set_config('MOZ_PGO', depends('MOZ_PGO')(lambda x: bool(x)))
add_old_configure_assignment('MOZ_PGO', depends('MOZ_PGO')(lambda x: bool(x)))

# yasm detection
# ==============================================================
yasm = check_prog('YASM', ['yasm'], allow_missing=True)

@depends_if(yasm)
@checking('yasm version')
def yasm_version(yasm):
    version = check_cmd_output(
        yasm, '--version',
        onerror=lambda: die('Failed to get yasm version.')
    ).splitlines()[0].split()[1]
    return Version(version)

# Until we move all the yasm consumers out of old-configure.
# bug 1257904
add_old_configure_assignment('_YASM_MAJOR_VERSION',
                             yasm_version.major)
add_old_configure_assignment('_YASM_MINOR_VERSION',
                             yasm_version.minor)

@depends(yasm, target)
def yasm_asflags(yasm, target):
    if yasm:
        asflags = {
            ('OSX', 'x86'): '-f macho32',
            ('OSX', 'x86_64'): '-f macho64',
            ('WINNT', 'x86'): '-f win32',
            ('WINNT', 'x86_64'): '-f x64',
        }.get((target.os, target.cpu), None)
        if asflags is None:
            # We're assuming every x86 platform we support that's
            # not Windows or Mac is ELF.
            if target.cpu == 'x86':
                asflags = '-f elf32'
            elif target.cpu == 'x86_64':
                asflags = '-f elf64'
        if asflags:
            asflags += ' -rnasm -pnasm'
        return asflags

set_config('YASM_ASFLAGS', yasm_asflags)

@depends(yasm_asflags)
def have_yasm(value):
    if value:
        return True

set_config('HAVE_YASM', have_yasm)
# Until the YASM variable is not necessary in old-configure.
add_old_configure_assignment('YASM', have_yasm)

# Android NDK
# ==============================================================

@depends('--disable-compile-environment', build_project, gonkdir, '--help')
def compiling_android(compile_env, build_project, gonkdir, _):
    return compile_env and (gonkdir or build_project in ('mobile/android', 'js'))

include('android-ndk.configure', when=compiling_android)

# MacOS deployment target version
# ==============================================================
# This needs to happen before any compilation test is done.

option('--enable-macos-target', env='MACOSX_DEPLOYMENT_TARGET', nargs=1,
       default='10.7', help='Set the minimum MacOS version needed at runtime')

@depends('--enable-macos-target', target)
@imports(_from='os', _import='environ')
def macos_target(value, target):
    if value and target.os == 'OSX':
        # Ensure every compiler process we spawn uses this value.
        environ['MACOSX_DEPLOYMENT_TARGET'] = value[0]
        return value[0]
    if value and value.origin != 'default':
        die('--enable-macos-target cannot be used when targeting %s',
            target.os)


set_config('MACOSX_DEPLOYMENT_TARGET', macos_target)
add_old_configure_assignment('MACOSX_DEPLOYMENT_TARGET', macos_target)


# Compiler wrappers
# ==============================================================
# Normally, we'd use js_option and automatically have those variables
# propagated to js/src, but things are complicated by possible additional
# wrappers in CC/CXX, and by other subconfigures that do not handle those
# options and do need CC/CXX altered.
option('--with-compiler-wrapper', env='COMPILER_WRAPPER', nargs=1,
       help='Enable compiling with wrappers such as distcc and ccache')

option('--with-ccache', env='CCACHE', nargs='?',
       help='Enable compiling with ccache')

@depends_if('--with-ccache')
def ccache(value):
    if len(value):
        return value
    # If --with-ccache was given without an explicit value, we default to
    # 'ccache'.
    return 'ccache'

ccache = check_prog('CCACHE', progs=(), input=ccache)

@depends_if(ccache)
def using_ccache(ccache):
    return True

set_config('MOZ_USING_CCACHE', using_ccache)

@depends('--with-compiler-wrapper', ccache)
@imports(_from='mozbuild.shellutil', _import='split', _as='shell_split')
def compiler_wrapper(wrapper, ccache):
    if wrapper:
        raw_wrapper = wrapper[0]
        wrapper = shell_split(raw_wrapper)
        wrapper_program = find_program(wrapper[0])
        if not wrapper_program:
            die('Cannot find `%s` from the given compiler wrapper `%s`',
                wrapper[0], raw_wrapper)
        wrapper[0] = wrapper_program

    if ccache:
        if wrapper:
            return tuple([ccache] + wrapper)
        else:
            return (ccache,)
    elif wrapper:
        return tuple(wrapper)

add_old_configure_assignment('COMPILER_WRAPPER', compiler_wrapper)

@depends_if(compiler_wrapper)
def using_compiler_wrapper(compiler_wrapper):
    return True

set_config('MOZ_USING_COMPILER_WRAPPER', using_compiler_wrapper)


# Cross-compilation related things.
# ==============================================================
js_option('--with-toolchain-prefix', env='TOOLCHAIN_PREFIX', nargs=1,
          help='Prefix for the target toolchain')

@depends('--with-toolchain-prefix', target, cross_compiling)
def toolchain_prefix(value, target, cross_compiling):
    if value:
        return tuple(value)
    if cross_compiling:
        return ('%s-' % target.toolchain, '%s-' % target.alias)

@depends(toolchain_prefix, target)
def first_toolchain_prefix(toolchain_prefix, target):
    # Pass TOOLCHAIN_PREFIX down to the build system if it was given from the
    # command line/environment (in which case there's only one value in the tuple),
    # or when cross-compiling for Android.
    if toolchain_prefix and (target.os == 'Android' or len(toolchain_prefix) == 1):
        return toolchain_prefix[0]

set_config('TOOLCHAIN_PREFIX', first_toolchain_prefix)
add_old_configure_assignment('TOOLCHAIN_PREFIX', first_toolchain_prefix)


# Compilers
# ==============================================================
include('compilers-util.configure')

def try_preprocess(compiler, language, source):
    return try_invoke_compiler(compiler, language, source, ['-E'])

@imports(_from='mozbuild.configure.constants', _import='CompilerType')
@imports(_from='mozbuild.configure.constants',
         _import='CPU_preprocessor_checks')
@imports(_from='mozbuild.configure.constants',
         _import='kernel_preprocessor_checks')
@imports(_from='textwrap', _import='dedent')
def get_compiler_info(compiler, language):
    '''Returns information about the given `compiler` (command line in the
    form of a list or tuple), in the given `language`.

    The returned information includes:
    - the compiler type (msvc, clang-cl, clang or gcc)
    - the compiler version
    - the compiler supported language
    - the compiler supported language version
    '''
    # Note: MSVC doesn't expose __STDC_VERSION__. It does expose __STDC__,
    # but only when given the -Za option, which disables compiler
    # extensions.
    # Note: We'd normally do a version check for clang, but versions of clang
    # in Xcode have a completely different versioning scheme despite exposing
    # the version with the same defines.
    # So instead, we make things such that the version is missing when the
    # clang used is below the minimum supported version (currently clang 3.6).
    # We then only include the version information when the C++ compiler
    # matches the feature check, so that an unsupported version of clang would
    # have no version number.
    check = dedent('''\
        #if defined(_MSC_VER)
        #if defined(__clang__)
        %COMPILER "clang-cl"
        %VERSION _MSC_FULL_VER
        #else
        %COMPILER "msvc"
        %VERSION _MSC_FULL_VER
        #endif
        #elif defined(__clang__)
        %COMPILER "clang"
        #  if !__cplusplus || __has_feature(cxx_alignof)
        %VERSION __clang_major__.__clang_minor__.__clang_patchlevel__
        #  endif
        #elif defined(__GNUC__)
        %COMPILER "gcc"
        %VERSION __GNUC__.__GNUC_MINOR__.__GNUC_PATCHLEVEL__
        #endif

        #if __cplusplus
        %cplusplus __cplusplus
        #elif __STDC_VERSION__
        %STDC_VERSION __STDC_VERSION__
        #elif __STDC__
        %STDC_VERSION 198900L
        #endif
    ''')

    # While we're doing some preprocessing, we might as well do some more
    # preprocessor-based tests at the same time, to check the toolchain
    # matches what we want.
    for name, preprocessor_checks in (
        ('CPU', CPU_preprocessor_checks),
        ('KERNEL', kernel_preprocessor_checks),
    ):
        for n, (value, condition) in enumerate(preprocessor_checks.iteritems()):
            check += dedent('''\
                #%(if)s %(condition)s
                %%%(name)s "%(value)s"
            ''' % {
                'if': 'elif' if n else 'if',
                'condition': condition,
                'name': name,
                'value': value,
            })
        check += '#endif\n'

    # Also check for endianness. The advantage of living in modern times is
    # that all the modern compilers we support now have __BYTE_ORDER__ defined
    # by the preprocessor, except MSVC, which only supports little endian.
    check += dedent('''\
        #if _MSC_VER || __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
        %ENDIANNESS "little"
        #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
        %ENDIANNESS "big"
        #endif
    ''')

    result = try_preprocess(compiler, language, check)

    if not result:
        raise FatalCheckError(
            'Unknown compiler or compiler not supported.')

    # Metadata emitted by preprocessors such as GCC with LANG=ja_JP.utf-8 may
    # have non-ASCII characters. Treat the output as bytearray.
    data = {}
    for line in result.splitlines():
        if line.startswith(b'%'):
            k, _, v = line.partition(' ')
            k = k.lstrip('%')
            data[k] = v.replace(' ', '').lstrip('"').rstrip('"')
            log.debug('%s = %s', k, data[k])

    try:
        type = CompilerType(data['COMPILER'])
    except:
        raise FatalCheckError(
            'Unknown compiler or compiler not supported.')

    cplusplus = int(data.get('cplusplus', '0L').rstrip('L'))
    stdc_version = int(data.get('STDC_VERSION', '0L').rstrip('L'))

    version = data.get('VERSION')
    if version and type in ('msvc', 'clang-cl'):
        msc_ver = version
        version = msc_ver[0:2]
        if len(msc_ver) > 2:
            version += '.' + msc_ver[2:4]
        if len(msc_ver) > 4:
            version += '.' + msc_ver[4:]

    if version:
        version = Version(version)

    return namespace(
        type=type,
        version=version,
        cpu=data.get('CPU'),
        kernel=data.get('KERNEL'),
        endianness=data.get('ENDIANNESS'),
        language='C++' if cplusplus else 'C',
        language_version=cplusplus if cplusplus else stdc_version,
    )


@imports(_from='mozbuild.shellutil', _import='quote')
def check_compiler(compiler, language, target):
    info = get_compiler_info(compiler, language)

    flags = []

    def append_flag(flag):
        if flag not in flags:
            if info.type == 'clang-cl':
                flags.append('-Xclang')
            flags.append(flag)

    # Check language standards
    # --------------------------------------------------------------------
    if language != info.language:
        raise FatalCheckError(
            '`%s` is not a %s compiler.' % (quote(*compiler), language))

    # Note: We do a strict version check because there sometimes are backwards
    # incompatible changes in the standard, and not all code that compiles as
    # C99 compiles as e.g. C11 (as of writing, this is true of libnestegg, for
    # example)
    if info.language == 'C' and info.language_version != 199901:
        if info.type in ('clang-cl', 'clang', 'gcc'):
            append_flag('-std=gnu99')

    # Note: MSVC, while supporting C++11, still reports 199711L for __cplusplus.
    # Note: this is a strict version check because we used to always add
    # -std=gnu++11.
    if info.language == 'C++':
        if info.type in ('clang', 'gcc') and info.language_version != 201103:
            append_flag('-std=gnu++11')
        # MSVC 2015 headers include C++14 features, but don't guard them
        # with appropriate checks.
        if info.type == 'clang-cl' and info.language_version != 201402:
            append_flag('-std=c++14')

    # We force clang-cl to emulate Visual C++ 2015 Update 3 with fallback to
    # cl.exe.
    if info.type == 'clang-cl' and info.version != '19.00.24213':
        # Those flags are direct clang-cl flags that don't need -Xclang, add
        # them directly.
        flags.append('-fms-compatibility-version=19.00.24213')
        flags.append('-fallback')

    # Check compiler target
    # --------------------------------------------------------------------
    if not info.cpu or info.cpu != target.cpu:
        if info.type == 'clang':
            append_flag('--target=%s' % target.toolchain)
        elif info.type == 'gcc':
            same_arch_different_bits = (
                ('x86', 'x86_64'),
                ('ppc', 'ppc64'),
                ('sparc', 'sparc64'),
            )
            if (target.cpu, info.cpu) in same_arch_different_bits:
                append_flag('-m32')
            elif (info.cpu, target.cpu) in same_arch_different_bits:
                append_flag('-m64')

    if not info.kernel or info.kernel != target.kernel:
        if info.type == 'clang':
            append_flag('--target=%s' % target.toolchain)

    if not info.endianness or info.endianness != target.endianness:
        if info.type == 'clang':
            append_flag('--target=%s' % target.toolchain)

    return namespace(
        type=info.type,
        version=info.version,
        target_cpu=info.cpu,
        target_kernel=info.kernel,
        target_endianness=info.endianness,
        flags=flags,
    )


@imports(_from='__builtin__', _import='open')
@imports('json')
@imports('subprocess')
@imports('sys')
def get_vc_paths(topsrcdir):
    def vswhere(args):
        encoding = 'mbcs' if sys.platform == 'win32' else 'utf-8'
        return json.loads(subprocess.check_output([os.path.join(topsrcdir, 'build/win32/vswhere.exe'), '-format', 'json'] + args).decode(encoding, 'replace'))

    # Can't pass -requires with -legacy, so query each separately.
    # Legacy versions first (VS2015)
    for install in vswhere(['-legacy', '-version', '[14.0,15.0)']):
        version = Version(install['installationVersion'])
        # Skip anything older than VS2015.
        if version < '14':
            continue
        path = install['installationPath']

        yield (Version(install['installationVersion']), {
            'x64': [os.path.join(path, r'VC\bin\amd64')],
            # The x64->x86 cross toolchain requires DLLs from the native x64 toolchain.
            'x86': [os.path.join(path, r'VC\bin\amd64_x86'), os.path.join(path, r'VC\bin\amd64')],
        })
    # Then VS2017 and newer.
    for install in vswhere(['-requires', 'Microsoft.VisualStudio.Component.VC.Tools.x86.x64']):
        path = install['installationPath']
        tools_version = open(os.path.join(path, r'VC\Auxiliary\Build\Microsoft.VCToolsVersion.default.txt'), 'rb').read().strip()
        tools_path = os.path.join(path, r'VC\Tools\MSVC', tools_version, r'bin\HostX64')
        yield (Version(install['installationVersion']), {
            'x64': [os.path.join(tools_path, 'x64')],
            # The x64->x86 cross toolchain requires DLLs from the native x64 toolchain.
            'x86': [os.path.join(tools_path, 'x86'), os.path.join(tools_path, 'x64')],
        })

js_option('--with-visual-studio-version', nargs=1,
          choices=('2015', '2017'),
          help='Select a specific Visual Studio version to use')

@depends('--with-visual-studio-version')
def vs_major_version(value):
    if value:
        return {'2015': 14,
                '2017': 15}[value[0]]

@depends(host, target, vs_major_version, check_build_environment, '--with-visual-studio-version')
@imports(_from='__builtin__', _import='sorted')
@imports(_from='operator', _import='itemgetter')
@imports('platform')
def vc_compiler_path(host, target, vs_major_version, env, vs_release_name):
    if host.kernel != 'WINNT':
        return
    vc_target = {
        'x86': 'x86',
        'x86_64': 'x64',
        'arm': 'arm',
    }.get(target.cpu)
    if vc_target is None:
        return

    all_versions = sorted(get_vc_paths(env.topsrcdir), key=itemgetter(0))
    if not all_versions:
        return
    if vs_major_version:
        versions = [d for (v, d) in all_versions if v.major == vs_major_version]
        if not versions:
            die('Visual Studio %s could not be found!' % vs_release_name)
        data = versions[0]
    else:
        # Choose the newest version.
        data = all_versions[-1][1]
    paths = data.get(vc_target)
    if not paths:
        return
    return paths


@depends(vc_compiler_path)
@imports('os')
def toolchain_search_path(vc_compiler_path):
    if vc_compiler_path:
        result = [os.environ.get('PATH')]
        result.extend(vc_compiler_path)
        # We're going to alter PATH for good in windows.configure, but we also
        # need to do it for the valid_compiler() check below.
        os.environ['PATH'] = os.pathsep.join(result)
        return result


@template
def default_c_compilers(host_or_target):
    '''Template defining the set of default C compilers for the host and
    target platforms.
    `host_or_target` is either `host` or `target` (the @depends functions
    from init.configure.
    '''
    assert host_or_target in (host, target)

    @depends(host_or_target, target, toolchain_prefix)
    def default_c_compilers(host_or_target, target, toolchain_prefix):
        gcc = ('gcc',)
        if toolchain_prefix and host_or_target is target:
            gcc = tuple('%sgcc' % p for p in toolchain_prefix) + gcc

        if host_or_target.kernel == 'WINNT':
            return ('cl', 'clang-cl') + gcc + ('clang',)
        if host_or_target.kernel == 'Darwin':
            return ('clang',)
        return gcc + ('clang',)

    return default_c_compilers


@template
def default_cxx_compilers(c_compiler):
    '''Template defining the set of default C++ compilers for the host and
    target platforms.
    `c_compiler` is the @depends function returning a Compiler instance for
    the desired platform.

    Because the build system expects the C and C++ compilers to be from the
    same compiler suite, we derive the default C++ compilers from the C
    compiler that was found if none was provided.
    '''

    @depends(c_compiler)
    def default_cxx_compilers(c_compiler):
        dir = os.path.dirname(c_compiler.compiler)
        file = os.path.basename(c_compiler.compiler)

        if c_compiler.type == 'gcc':
            return (os.path.join(dir, file.replace('gcc', 'g++')),)

        if c_compiler.type == 'clang':
            return (os.path.join(dir, file.replace('clang', 'clang++')),)

        return (c_compiler.compiler,)

    return default_cxx_compilers


@template
def compiler(language, host_or_target, c_compiler=None, other_compiler=None,
             other_c_compiler=None):
    '''Template handling the generic base checks for the compiler for the
    given `language` on the given platform (`host_or_target`).
    `host_or_target` is either `host` or `target` (the @depends functions
    from init.configure.
    When the language is 'C++', `c_compiler` is the result of the `compiler`
    template for the language 'C' for the same `host_or_target`.
    When `host_or_target` is `host`, `other_compiler` is the result of the
    `compiler` template for the same `language` for `target`.
    When `host_or_target` is `host` and the language is 'C++',
    `other_c_compiler` is the result of the `compiler` template for the
    language 'C' for `target`.
    '''
    assert host_or_target in (host, target)
    assert language in ('C', 'C++')
    assert language == 'C' or c_compiler is not None
    assert host_or_target == target or other_compiler is not None
    assert language == 'C' or host_or_target == target or \
        other_c_compiler is not None

    host_or_target_str = {
        host: 'host',
        target: 'target',
    }[host_or_target]

    var = {
        ('C', target): 'CC',
        ('C++', target): 'CXX',
        ('C', host): 'HOST_CC',
        ('C++', host): 'HOST_CXX',
    }[language, host_or_target]

    default_compilers = {
        'C': lambda: default_c_compilers(host_or_target),
        'C++': lambda: default_cxx_compilers(c_compiler),
    }[language]()

    what='the %s %s compiler' % (host_or_target_str, language)

    option(env=var, nargs=1, help='Path to %s' % what)

    # Handle the compiler given by the user through one of the CC/CXX/HOST_CC/
    # HOST_CXX variables.
    @depends_if(var)
    @imports(_from='itertools', _import='takewhile')
    @imports(_from='mozbuild.shellutil', _import='split', _as='shell_split')
    def provided_compiler(cmd):
        # Historically, the compiler variables have contained more than the
        # path to the compiler itself. So for backwards compatibility, try to
        # find what is what in there, assuming the first dash-prefixed item is
        # a compiler option, the item before that is the compiler, and anything
        # before that is a compiler wrapper.
        cmd = shell_split(cmd[0])

        without_flags = list(takewhile(lambda x: not x.startswith('-'), cmd))

        return namespace(
            wrapper=without_flags[:-1],
            compiler=without_flags[-1],
            flags=cmd[len(without_flags):],
        )

    # Derive the host compiler from the corresponding target compiler when no
    # explicit compiler was given and we're not cross compiling. For the C++
    # compiler, though, prefer to derive from the host C compiler when it
    # doesn't match the target C compiler.
    # As a special case, since clang supports all kinds of targets in the same
    # executable, when cross compiling with clang, default to the same compiler
    # as the target compiler, resetting flags.
    if host_or_target == host:
        if other_c_compiler is not None:
            args = (c_compiler, other_c_compiler)
        else:
            args = ()

        @depends(provided_compiler, other_compiler, cross_compiling, *args)
        def provided_compiler(value, other_compiler, cross_compiling, *args):
            if value:
                return value
            c_compiler, other_c_compiler = args if args else (None, None)
            if not cross_compiling and c_compiler == other_c_compiler:
                return other_compiler
            if cross_compiling and other_compiler.type == 'clang':
                return namespace(**{
                    k: [] if k == 'flags' else v
                    for k, v in other_compiler.__dict__.iteritems()
                })

    # Normally, we'd use `var` instead of `_var`, but the interaction with
    # old-configure complicates things, and for now, we a) can't take the plain
    # result from check_prog as CC/CXX/HOST_CC/HOST_CXX and b) have to let
    # old-configure AC_SUBST it (because it's autoconf doing it, not us)
    compiler = check_prog('_%s' % var, what=what, progs=default_compilers,
                          input=provided_compiler.compiler,
                          paths=toolchain_search_path)

    @depends(compiler, provided_compiler, compiler_wrapper, host_or_target)
    @checking('whether %s can be used' % what, lambda x: bool(x))
    @imports(_from='mozbuild.shellutil', _import='quote')
    def valid_compiler(compiler, provided_compiler, compiler_wrapper,
                       host_or_target):
        wrapper = list(compiler_wrapper or ())
        if provided_compiler:
            provided_wrapper = list(provided_compiler.wrapper)
            # When doing a subconfigure, the compiler is set by old-configure
            # and it contains the wrappers from --with-compiler-wrapper and
            # --with-ccache.
            if provided_wrapper[:len(wrapper)] == wrapper:
                provided_wrapper = provided_wrapper[len(wrapper):]
            wrapper.extend(provided_wrapper)
            flags = provided_compiler.flags
        else:
            flags = []

        # Ideally, we'd always use the absolute path, but unfortunately, on
        # Windows, the compiler is very often in a directory containing spaces.
        # Unfortunately, due to the way autoconf does its compiler tests with
        # eval, that doesn't work out. So in that case, check that the
        # compiler can still be found in $PATH, and use the file name instead
        # of the full path.
        if quote(compiler) != compiler:
            full_path = os.path.abspath(compiler)
            compiler = os.path.basename(compiler)
            found_compiler = find_program(compiler)
            if not found_compiler:
                die('%s is not in your $PATH'
                    % quote(os.path.dirname(full_path)))
            if os.path.normcase(find_program(compiler)) != os.path.normcase(
                    full_path):
                die('Found `%s` before `%s` in your $PATH. '
                    'Please reorder your $PATH.',
                    quote(os.path.dirname(found_compiler)),
                    quote(os.path.dirname(full_path)))

        info = check_compiler(wrapper + [compiler] + flags, language,
                              host_or_target)

        # Check that the additional flags we got are enough to not require any
        # more flags.
        if info.flags:
            flags += info.flags
            info = check_compiler(wrapper + [compiler] + flags, language,
                                  host_or_target)

        if not info.target_cpu or info.target_cpu != host_or_target.cpu:
            raise FatalCheckError(
                '%s %s compiler target CPU (%s) does not match --%s CPU (%s)'
                % (host_or_target_str.capitalize(), language,
                   info.target_cpu or 'unknown', host_or_target_str,
                   host_or_target.raw_cpu))

        if not info.target_kernel or (info.target_kernel !=
                                      host_or_target.kernel):
            raise FatalCheckError(
                '%s %s compiler target kernel (%s) does not match --%s kernel (%s)'
                % (host_or_target_str.capitalize(), language,
                   info.target_kernel or 'unknown', host_or_target_str,
                   host_or_target.kernel))

        if not info.target_endianness or (info.target_endianness !=
                                          host_or_target.endianness):
            raise FatalCheckError(
                '%s %s compiler target endianness (%s) does not match --%s '
                'endianness (%s)'
                % (host_or_target_str.capitalize(), language,
                   info.target_endianness or 'unknown', host_or_target_str,
                   host_or_target.endianness))

        if info.flags:
            raise FatalCheckError(
                'Unknown compiler or compiler not supported.')

        # Compiler version checks
        # ===================================================
        # Check the compiler version here instead of in `compiler_version` so
        # that the `checking` message doesn't pretend the compiler can be used
        # to then bail out one line later.
        if info.type == 'gcc' and info.version < '4.8.0':
            raise FatalCheckError(
                'Only GCC 4.8 or newer is supported (found version %s).'
                % info.version)

        # If you want to bump the version check here search for
        # __cpp_static_assert above, and see the associated comment.
        if info.type == 'clang' and not info.version:
            raise FatalCheckError(
                'Only clang/llvm 3.6 or newer is supported.')

        if info.type == 'msvc':
            if info.version < '19.00.24213':
                raise FatalCheckError(
                    'This version (%s) of the MSVC compiler is not '
                    'supported.\n'
                    'You must install Visual C++ 2015 Update 3 or newer in '
                    'order to build.\n'
                    'See https://developer.mozilla.org/en/'
                    'Windows_Build_Prerequisites' % info.version)

        return namespace(
            wrapper=wrapper,
            compiler=compiler,
            flags=flags,
            type=info.type,
            version=info.version,
            language=language,
        )

    @depends(valid_compiler)
    @checking('%s version' % what)
    def compiler_version(compiler):
        return compiler.version

    if language == 'C++':
        @depends(valid_compiler, c_compiler)
        def valid_compiler(compiler, c_compiler):
            if compiler.type != c_compiler.type:
                die('The %s C compiler is %s, while the %s C++ compiler is '
                    '%s. Need to use the same compiler suite.',
                    host_or_target_str, c_compiler.type,
                    host_or_target_str, compiler.type)

            if compiler.version != c_compiler.version:
                die('The %s C compiler is version %s, while the %s C++ '
                    'compiler is version %s. Need to use the same compiler '
                    'version.',
                    host_or_target_str, c_compiler.version,
                    host_or_target_str, compiler.version)
            return compiler

    # Set CC/CXX/HOST_CC/HOST_CXX for old-configure, which needs the wrapper
    # and the flags that were part of the user input for those variables to
    # be provided.
    add_old_configure_assignment(var, depends_if(valid_compiler)(
        lambda x: list(x.wrapper) + [x.compiler] + list(x.flags)))

    # Set CC_TYPE/CC_VERSION/HOST_CC_TYPE/HOST_CC_VERSION to allow
    # old-configure to do some of its still existing checks.
    if language == 'C':
        set_config(
            '%s_TYPE' % var, valid_compiler.type)
        add_old_configure_assignment(
            '%s_TYPE' % var, valid_compiler.type)
        add_old_configure_assignment(
            '%s_VERSION' % var, valid_compiler.version)

    valid_compiler = compiler_class(valid_compiler)

    def compiler_error():
        raise FatalCheckError('Failed compiling a simple %s source with %s'
                              % (language, what))

    valid_compiler.try_compile(check_msg='%s works' % what,
                               onerror=compiler_error)


    # Set CPP/CXXCPP for both the build system and old-configure. We don't
    # need to check this works for preprocessing, because we already relied
    # on $CC -E/$CXX -E doing preprocessing work to validate the compiler
    # in the first place.
    if host_or_target == target:
        pp_var = {
            'C': 'CPP',
            'C++': 'CXXCPP',
        }[language]

        preprocessor = depends_if(valid_compiler)(
                lambda x: list(x.wrapper) + [x.compiler, '-E'] + list(x.flags))

        set_config(pp_var, preprocessor)
        add_old_configure_assignment(pp_var, preprocessor)

    if language == 'C':
        linker_var = {
            target: 'LD',
            host: 'HOST_LD',
        }[host_or_target]

        @deprecated_option(env=linker_var, nargs=1)
        def linker(value):
            if value:
                return value[0]

        @depends(valid_compiler, linker)
        def unused_linker(compiler, linker):
            if linker and compiler.type != 'msvc':
                log.warning('The value of %s is not used by this build system.'
                            % linker_var)

        if host_or_target == target:
            @depends(valid_compiler)
            def is_msvc(compiler):
                return compiler.type == 'msvc'

            imply_option('LINK', linker, reason='LD', when=is_msvc)

    return valid_compiler


c_compiler = compiler('C', target)
cxx_compiler = compiler('C++', target, c_compiler=c_compiler)
host_c_compiler = compiler('C', host, other_compiler=c_compiler)
host_cxx_compiler = compiler('C++', host, c_compiler=host_c_compiler,
                             other_compiler=cxx_compiler,
                             other_c_compiler=c_compiler)

# Generic compiler-based conditions.
non_msvc_compiler = depends(c_compiler)(lambda info: info.type != 'msvc')
building_with_gcc = depends(c_compiler)(lambda info: info.type == 'gcc')

include('compile-checks.configure')

@depends(have_64_bit,
         try_compile(body='static_assert(sizeof(void *) == 8, "")',
                     check_msg='for 64-bit OS'))
def check_have_64_bit(have_64_bit, compiler_have_64_bit):
    if have_64_bit != compiler_have_64_bit:
        configure_error('The target compiler does not agree with configure '
                        'about the target bitness.')


@depends(c_compiler)
def default_debug_flags(compiler_info):
    # Debug info is ON by default.
    if compiler_info.type in ('msvc', 'clang-cl'):
        return '-Zi'
    return '-g'

option(env='MOZ_DEBUG_FLAGS',
       nargs=1,
       help='Debug compiler flags')

imply_option('--enable-debug-symbols',
             depends_if('--enable-debug')(lambda v: v))

js_option('--enable-debug-symbols',
          nargs='?',
          default=True,
          help='Enable debug symbols using the given compiler flags')

set_config('MOZ_DEBUG_SYMBOLS',
           depends_if('--enable-debug-symbols')(lambda _: True))

@depends('MOZ_DEBUG_FLAGS', '--enable-debug-symbols', default_debug_flags)
def debug_flags(env_debug_flags, enable_debug_flags, default_debug_flags):
    # If MOZ_DEBUG_FLAGS is set, and --enable-debug-symbols is set to a value,
    # --enable-debug-symbols takes precedence. Note, the value of
    # --enable-debug-symbols may be implied by --enable-debug.
    if len(enable_debug_flags):
        return enable_debug_flags[0]
    if env_debug_flags:
        return env_debug_flags[0]
    return default_debug_flags

set_config('MOZ_DEBUG_FLAGS', debug_flags)
add_old_configure_assignment('MOZ_DEBUG_FLAGS', debug_flags)

# Some standard library headers (notably bionic on Android) declare standard
# functions (e.g. getchar()) and also #define macros for those standard
# functions.  libc++ deals with this by doing something like the following
# (explanatory comments added):
#
#   #ifdef FUNC
#   // Capture the definition of FUNC.
#   inline _LIBCPP_INLINE_VISIBILITY int __libcpp_FUNC(...) { return FUNC(...); }
#   #undef FUNC
#   // Use a real inline definition.
#   inline _LIBCPP_INLINE_VISIBILITY int FUNC(...) { return _libcpp_FUNC(...); }
#   #endif
#
# _LIBCPP_INLINE_VISIBILITY is typically defined as:
#
#   __attribute__((__visibility__("hidden"), __always_inline__))
#
# Unfortunately, this interacts badly with our system header wrappers, as the:
#
#   #pragma GCC visibility push(default)
#
# that they do prior to including the actual system header is treated by the
# compiler as an explicit declaration of visibility on every function declared
# in the header.  Therefore, when the libc++ code above is encountered, it is
# as though the compiler has effectively seen:
#
#   int FUNC(...) __attribute__((__visibility__("default")));
#   int FUNC(...) __attribute__((__visibility__("hidden")));
#
# and the compiler complains about the mismatched visibility declarations.
#
# However, libc++ will only define _LIBCPP_INLINE_VISIBILITY if there is no
# existing definition.  We can therefore define it to the empty string (since
# we are properly managing visibility ourselves) and avoid this whole mess.
# Note that we don't need to do this with gcc, as libc++ detects gcc and
# effectively does the same thing we are doing here.
@depends(c_compiler, target)
def libcxx_inline_visibility(c_compiler, target):
    if c_compiler.type == 'clang' and target.os == 'Android':
        return ''

set_define('_LIBCPP_INLINE_VISIBILITY', libcxx_inline_visibility)
set_define('_LIBCPP_INLINE_VISIBILITY_EXCEPT_GCC49', libcxx_inline_visibility)

@depends(target, check_build_environment)
def visibility_flags(target, env):
    if target.os != 'WINNT':
        if target.kernel == 'Darwin':
            return ('-fvisibility=hidden', '-fvisibility-inlines-hidden')
        return ('-I%s/system_wrappers' % os.path.join(env.dist),
                '-include',
                '%s/config/gcc_hidden.h' % env.topsrcdir)

@depends(target, visibility_flags)
def wrap_system_includes(target, visibility_flags):
    if visibility_flags and target.kernel != 'Darwin':
        return True

set_define('HAVE_VISIBILITY_HIDDEN_ATTRIBUTE',
           depends(visibility_flags)(lambda v: bool(v) or None))
set_define('HAVE_VISIBILITY_ATTRIBUTE',
           depends(visibility_flags)(lambda v: bool(v) or None))
set_config('WRAP_SYSTEM_INCLUDES', wrap_system_includes)
set_config('VISIBILITY_FLAGS', visibility_flags)

@depends(target)
def is_windows(target):
    return target.kernel == 'WINNT'

include('windows.configure', when=is_windows)
include('rust.configure')