--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/python3.8/site-packages/setuptools/msvc.py	Mon Jul 27 03:47:31 2020 -0400
@@ -0,0 +1,1825 @@
+"""
+Improved support for Microsoft Visual C++ compilers.
+
+Known supported compilers:
+--------------------------
+Microsoft Visual C++ 9.0:
+    Microsoft Visual C++ Compiler for Python 2.7 (x86, amd64)
+    Microsoft Windows SDK 6.1 (x86, x64, ia64)
+    Microsoft Windows SDK 7.0 (x86, x64, ia64)
+
+Microsoft Visual C++ 10.0:
+    Microsoft Windows SDK 7.1 (x86, x64, ia64)
+
+Microsoft Visual C++ 14.X:
+    Microsoft Visual C++ Build Tools 2015 (x86, x64, arm)
+    Microsoft Visual Studio Build Tools 2017 (x86, x64, arm, arm64)
+    Microsoft Visual Studio Build Tools 2019 (x86, x64, arm, arm64)
+
+This may also support compilers shipped with compatible Visual Studio versions.
+"""
+
+import json
+from io import open
+from os import listdir, pathsep
+from os.path import join, isfile, isdir, dirname
+import sys
+import platform
+import itertools
+import subprocess
+import distutils.errors
+from setuptools.extern.packaging.version import LegacyVersion
+
+from setuptools.extern.six.moves import filterfalse
+
+from .monkey import get_unpatched
+
+if platform.system() == 'Windows':
+    from setuptools.extern.six.moves import winreg
+    from os import environ
+else:
+    # Mock winreg and environ so the module can be imported on this platform.
+
+    class winreg:
+        HKEY_USERS = None
+        HKEY_CURRENT_USER = None
+        HKEY_LOCAL_MACHINE = None
+        HKEY_CLASSES_ROOT = None
+
+    environ = dict()
+
+_msvc9_suppress_errors = (
+    # msvc9compiler isn't available on some platforms
+    ImportError,
+
+    # msvc9compiler raises DistutilsPlatformError in some
+    # environments. See #1118.
+    distutils.errors.DistutilsPlatformError,
+)
+
+try:
+    from distutils.msvc9compiler import Reg
+except _msvc9_suppress_errors:
+    pass
+
+
+def msvc9_find_vcvarsall(version):
+    """
+    Patched "distutils.msvc9compiler.find_vcvarsall" to use the standalone
+    compiler build for Python
+    (VCForPython / Microsoft Visual C++ Compiler for Python 2.7).
+
+    Fall back to original behavior when the standalone compiler is not
+    available.
+
+    Redirect the path of "vcvarsall.bat".
+
+    Parameters
+    ----------
+    version: float
+        Required Microsoft Visual C++ version.
+
+    Return
+    ------
+    str
+        vcvarsall.bat path
+    """
+    vc_base = r'Software\%sMicrosoft\DevDiv\VCForPython\%0.1f'
+    key = vc_base % ('', version)
+    try:
+        # Per-user installs register the compiler path here
+        productdir = Reg.get_value(key, "installdir")
+    except KeyError:
+        try:
+            # All-user installs on a 64-bit system register here
+            key = vc_base % ('Wow6432Node\\', version)
+            productdir = Reg.get_value(key, "installdir")
+        except KeyError:
+            productdir = None
+
+    if productdir:
+        vcvarsall = join(productdir, "vcvarsall.bat")
+        if isfile(vcvarsall):
+            return vcvarsall
+
+    return get_unpatched(msvc9_find_vcvarsall)(version)
+
+
+def msvc9_query_vcvarsall(ver, arch='x86', *args, **kwargs):
+    """
+    Patched "distutils.msvc9compiler.query_vcvarsall" for support extra
+    Microsoft Visual C++ 9.0 and 10.0 compilers.
+
+    Set environment without use of "vcvarsall.bat".
+
+    Parameters
+    ----------
+    ver: float
+        Required Microsoft Visual C++ version.
+    arch: str
+        Target architecture.
+
+    Return
+    ------
+    dict
+        environment
+    """
+    # Try to get environment from vcvarsall.bat (Classical way)
+    try:
+        orig = get_unpatched(msvc9_query_vcvarsall)
+        return orig(ver, arch, *args, **kwargs)
+    except distutils.errors.DistutilsPlatformError:
+        # Pass error if Vcvarsall.bat is missing
+        pass
+    except ValueError:
+        # Pass error if environment not set after executing vcvarsall.bat
+        pass
+
+    # If error, try to set environment directly
+    try:
+        return EnvironmentInfo(arch, ver).return_env()
+    except distutils.errors.DistutilsPlatformError as exc:
+        _augment_exception(exc, ver, arch)
+        raise
+
+
+def _msvc14_find_vc2015():
+    """Python 3.8 "distutils/_msvccompiler.py" backport"""
+    try:
+        key = winreg.OpenKey(
+            winreg.HKEY_LOCAL_MACHINE,
+            r"Software\Microsoft\VisualStudio\SxS\VC7",
+            0,
+            winreg.KEY_READ | winreg.KEY_WOW64_32KEY
+        )
+    except OSError:
+        return None, None
+
+    best_version = 0
+    best_dir = None
+    with key:
+        for i in itertools.count():
+            try:
+                v, vc_dir, vt = winreg.EnumValue(key, i)
+            except OSError:
+                break
+            if v and vt == winreg.REG_SZ and isdir(vc_dir):
+                try:
+                    version = int(float(v))
+                except (ValueError, TypeError):
+                    continue
+                if version >= 14 and version > best_version:
+                    best_version, best_dir = version, vc_dir
+    return best_version, best_dir
+
+
+def _msvc14_find_vc2017():
+    """Python 3.8 "distutils/_msvccompiler.py" backport
+
+    Returns "15, path" based on the result of invoking vswhere.exe
+    If no install is found, returns "None, None"
+
+    The version is returned to avoid unnecessarily changing the function
+    result. It may be ignored when the path is not None.
+
+    If vswhere.exe is not available, by definition, VS 2017 is not
+    installed.
+    """
+    root = environ.get("ProgramFiles(x86)") or environ.get("ProgramFiles")
+    if not root:
+        return None, None
+
+    try:
+        path = subprocess.check_output([
+            join(root, "Microsoft Visual Studio", "Installer", "vswhere.exe"),
+            "-latest",
+            "-prerelease",
+            "-requires", "Microsoft.VisualStudio.Component.VC.Tools.x86.x64",
+            "-property", "installationPath",
+            "-products", "*",
+        ]).decode(encoding="mbcs", errors="strict").strip()
+    except (subprocess.CalledProcessError, OSError, UnicodeDecodeError):
+        return None, None
+
+    path = join(path, "VC", "Auxiliary", "Build")
+    if isdir(path):
+        return 15, path
+
+    return None, None
+
+
+PLAT_SPEC_TO_RUNTIME = {
+    'x86': 'x86',
+    'x86_amd64': 'x64',
+    'x86_arm': 'arm',
+    'x86_arm64': 'arm64'
+}
+
+
+def _msvc14_find_vcvarsall(plat_spec):
+    """Python 3.8 "distutils/_msvccompiler.py" backport"""
+    _, best_dir = _msvc14_find_vc2017()
+    vcruntime = None
+
+    if plat_spec in PLAT_SPEC_TO_RUNTIME:
+        vcruntime_plat = PLAT_SPEC_TO_RUNTIME[plat_spec]
+    else:
+        vcruntime_plat = 'x64' if 'amd64' in plat_spec else 'x86'
+
+    if best_dir:
+        vcredist = join(best_dir, "..", "..", "redist", "MSVC", "**",
+                        vcruntime_plat, "Microsoft.VC14*.CRT",
+                        "vcruntime140.dll")
+        try:
+            import glob
+            vcruntime = glob.glob(vcredist, recursive=True)[-1]
+        except (ImportError, OSError, LookupError):
+            vcruntime = None
+
+    if not best_dir:
+        best_version, best_dir = _msvc14_find_vc2015()
+        if best_version:
+            vcruntime = join(best_dir, 'redist', vcruntime_plat,
+                             "Microsoft.VC140.CRT", "vcruntime140.dll")
+
+    if not best_dir:
+        return None, None
+
+    vcvarsall = join(best_dir, "vcvarsall.bat")
+    if not isfile(vcvarsall):
+        return None, None
+
+    if not vcruntime or not isfile(vcruntime):
+        vcruntime = None
+
+    return vcvarsall, vcruntime
+
+
+def _msvc14_get_vc_env(plat_spec):
+    """Python 3.8 "distutils/_msvccompiler.py" backport"""
+    if "DISTUTILS_USE_SDK" in environ:
+        return {
+            key.lower(): value
+            for key, value in environ.items()
+        }
+
+    vcvarsall, vcruntime = _msvc14_find_vcvarsall(plat_spec)
+    if not vcvarsall:
+        raise distutils.errors.DistutilsPlatformError(
+            "Unable to find vcvarsall.bat"
+        )
+
+    try:
+        out = subprocess.check_output(
+            'cmd /u /c "{}" {} && set'.format(vcvarsall, plat_spec),
+            stderr=subprocess.STDOUT,
+        ).decode('utf-16le', errors='replace')
+    except subprocess.CalledProcessError as exc:
+        raise distutils.errors.DistutilsPlatformError(
+            "Error executing {}".format(exc.cmd)
+        )
+
+    env = {
+        key.lower(): value
+        for key, _, value in
+        (line.partition('=') for line in out.splitlines())
+        if key and value
+    }
+
+    if vcruntime:
+        env['py_vcruntime_redist'] = vcruntime
+    return env
+
+
+def msvc14_get_vc_env(plat_spec):
+    """
+    Patched "distutils._msvccompiler._get_vc_env" for support extra
+    Microsoft Visual C++ 14.X compilers.
+
+    Set environment without use of "vcvarsall.bat".
+
+    Parameters
+    ----------
+    plat_spec: str
+        Target architecture.
+
+    Return
+    ------
+    dict
+        environment
+    """
+
+    # Always use backport from CPython 3.8
+    try:
+        return _msvc14_get_vc_env(plat_spec)
+    except distutils.errors.DistutilsPlatformError as exc:
+        _augment_exception(exc, 14.0)
+        raise
+
+
+def msvc14_gen_lib_options(*args, **kwargs):
+    """
+    Patched "distutils._msvccompiler.gen_lib_options" for fix
+    compatibility between "numpy.distutils" and "distutils._msvccompiler"
+    (for Numpy < 1.11.2)
+    """
+    if "numpy.distutils" in sys.modules:
+        import numpy as np
+        if LegacyVersion(np.__version__) < LegacyVersion('1.11.2'):
+            return np.distutils.ccompiler.gen_lib_options(*args, **kwargs)
+    return get_unpatched(msvc14_gen_lib_options)(*args, **kwargs)
+
+
+def _augment_exception(exc, version, arch=''):
+    """
+    Add details to the exception message to help guide the user
+    as to what action will resolve it.
+    """
+    # Error if MSVC++ directory not found or environment not set
+    message = exc.args[0]
+
+    if "vcvarsall" in message.lower() or "visual c" in message.lower():
+        # Special error message if MSVC++ not installed
+        tmpl = 'Microsoft Visual C++ {version:0.1f} is required.'
+        message = tmpl.format(**locals())
+        msdownload = 'www.microsoft.com/download/details.aspx?id=%d'
+        if version == 9.0:
+            if arch.lower().find('ia64') > -1:
+                # For VC++ 9.0, if IA64 support is needed, redirect user
+                # to Windows SDK 7.0.
+                # Note: No download link available from Microsoft.
+                message += ' Get it with "Microsoft Windows SDK 7.0"'
+            else:
+                # For VC++ 9.0 redirect user to Vc++ for Python 2.7 :
+                # This redirection link is maintained by Microsoft.
+                # Contact vspython@microsoft.com if it needs updating.
+                message += ' Get it from http://aka.ms/vcpython27'
+        elif version == 10.0:
+            # For VC++ 10.0 Redirect user to Windows SDK 7.1
+            message += ' Get it with "Microsoft Windows SDK 7.1": '
+            message += msdownload % 8279
+        elif version >= 14.0:
+            # For VC++ 14.X Redirect user to latest Visual C++ Build Tools
+            message += (' Get it with "Build Tools for Visual Studio": '
+                        r'https://visualstudio.microsoft.com/downloads/')
+
+    exc.args = (message, )
+
+
+class PlatformInfo:
+    """
+    Current and Target Architectures information.
+
+    Parameters
+    ----------
+    arch: str
+        Target architecture.
+    """
+    current_cpu = environ.get('processor_architecture', '').lower()
+
+    def __init__(self, arch):
+        self.arch = arch.lower().replace('x64', 'amd64')
+
+    @property
+    def target_cpu(self):
+        """
+        Return Target CPU architecture.
+
+        Return
+        ------
+        str
+            Target CPU
+        """
+        return self.arch[self.arch.find('_') + 1:]
+
+    def target_is_x86(self):
+        """
+        Return True if target CPU is x86 32 bits..
+
+        Return
+        ------
+        bool
+            CPU is x86 32 bits
+        """
+        return self.target_cpu == 'x86'
+
+    def current_is_x86(self):
+        """
+        Return True if current CPU is x86 32 bits..
+
+        Return
+        ------
+        bool
+            CPU is x86 32 bits
+        """
+        return self.current_cpu == 'x86'
+
+    def current_dir(self, hidex86=False, x64=False):
+        """
+        Current platform specific subfolder.
+
+        Parameters
+        ----------
+        hidex86: bool
+            return '' and not '\x86' if architecture is x86.
+        x64: bool
+            return '\x64' and not '\amd64' if architecture is amd64.
+
+        Return
+        ------
+        str
+            subfolder: '\target', or '' (see hidex86 parameter)
+        """
+        return (
+            '' if (self.current_cpu == 'x86' and hidex86) else
+            r'\x64' if (self.current_cpu == 'amd64' and x64) else
+            r'\%s' % self.current_cpu
+        )
+
+    def target_dir(self, hidex86=False, x64=False):
+        r"""
+        Target platform specific subfolder.
+
+        Parameters
+        ----------
+        hidex86: bool
+            return '' and not '\x86' if architecture is x86.
+        x64: bool
+            return '\x64' and not '\amd64' if architecture is amd64.
+
+        Return
+        ------
+        str
+            subfolder: '\current', or '' (see hidex86 parameter)
+        """
+        return (
+            '' if (self.target_cpu == 'x86' and hidex86) else
+            r'\x64' if (self.target_cpu == 'amd64' and x64) else
+            r'\%s' % self.target_cpu
+        )
+
+    def cross_dir(self, forcex86=False):
+        r"""
+        Cross platform specific subfolder.
+
+        Parameters
+        ----------
+        forcex86: bool
+            Use 'x86' as current architecture even if current architecture is
+            not x86.
+
+        Return
+        ------
+        str
+            subfolder: '' if target architecture is current architecture,
+            '\current_target' if not.
+        """
+        current = 'x86' if forcex86 else self.current_cpu
+        return (
+            '' if self.target_cpu == current else
+            self.target_dir().replace('\\', '\\%s_' % current)
+        )
+
+
+class RegistryInfo:
+    """
+    Microsoft Visual Studio related registry information.
+
+    Parameters
+    ----------
+    platform_info: PlatformInfo
+        "PlatformInfo" instance.
+    """
+    HKEYS = (winreg.HKEY_USERS,
+             winreg.HKEY_CURRENT_USER,
+             winreg.HKEY_LOCAL_MACHINE,
+             winreg.HKEY_CLASSES_ROOT)
+
+    def __init__(self, platform_info):
+        self.pi = platform_info
+
+    @property
+    def visualstudio(self):
+        """
+        Microsoft Visual Studio root registry key.
+
+        Return
+        ------
+        str
+            Registry key
+        """
+        return 'VisualStudio'
+
+    @property
+    def sxs(self):
+        """
+        Microsoft Visual Studio SxS registry key.
+
+        Return
+        ------
+        str
+            Registry key
+        """
+        return join(self.visualstudio, 'SxS')
+
+    @property
+    def vc(self):
+        """
+        Microsoft Visual C++ VC7 registry key.
+
+        Return
+        ------
+        str
+            Registry key
+        """
+        return join(self.sxs, 'VC7')
+
+    @property
+    def vs(self):
+        """
+        Microsoft Visual Studio VS7 registry key.
+
+        Return
+        ------
+        str
+            Registry key
+        """
+        return join(self.sxs, 'VS7')
+
+    @property
+    def vc_for_python(self):
+        """
+        Microsoft Visual C++ for Python registry key.
+
+        Return
+        ------
+        str
+            Registry key
+        """
+        return r'DevDiv\VCForPython'
+
+    @property
+    def microsoft_sdk(self):
+        """
+        Microsoft SDK registry key.
+
+        Return
+        ------
+        str
+            Registry key
+        """
+        return 'Microsoft SDKs'
+
+    @property
+    def windows_sdk(self):
+        """
+        Microsoft Windows/Platform SDK registry key.
+
+        Return
+        ------
+        str
+            Registry key
+        """
+        return join(self.microsoft_sdk, 'Windows')
+
+    @property
+    def netfx_sdk(self):
+        """
+        Microsoft .NET Framework SDK registry key.
+
+        Return
+        ------
+        str
+            Registry key
+        """
+        return join(self.microsoft_sdk, 'NETFXSDK')
+
+    @property
+    def windows_kits_roots(self):
+        """
+        Microsoft Windows Kits Roots registry key.
+
+        Return
+        ------
+        str
+            Registry key
+        """
+        return r'Windows Kits\Installed Roots'
+
+    def microsoft(self, key, x86=False):
+        """
+        Return key in Microsoft software registry.
+
+        Parameters
+        ----------
+        key: str
+            Registry key path where look.
+        x86: str
+            Force x86 software registry.
+
+        Return
+        ------
+        str
+            Registry key
+        """
+        node64 = '' if self.pi.current_is_x86() or x86 else 'Wow6432Node'
+        return join('Software', node64, 'Microsoft', key)
+
+    def lookup(self, key, name):
+        """
+        Look for values in registry in Microsoft software registry.
+
+        Parameters
+        ----------
+        key: str
+            Registry key path where look.
+        name: str
+            Value name to find.
+
+        Return
+        ------
+        str
+            value
+        """
+        key_read = winreg.KEY_READ
+        openkey = winreg.OpenKey
+        ms = self.microsoft
+        for hkey in self.HKEYS:
+            try:
+                bkey = openkey(hkey, ms(key), 0, key_read)
+            except (OSError, IOError):
+                if not self.pi.current_is_x86():
+                    try:
+                        bkey = openkey(hkey, ms(key, True), 0, key_read)
+                    except (OSError, IOError):
+                        continue
+                else:
+                    continue
+            try:
+                return winreg.QueryValueEx(bkey, name)[0]
+            except (OSError, IOError):
+                pass
+
+
+class SystemInfo:
+    """
+    Microsoft Windows and Visual Studio related system information.
+
+    Parameters
+    ----------
+    registry_info: RegistryInfo
+        "RegistryInfo" instance.
+    vc_ver: float
+        Required Microsoft Visual C++ version.
+    """
+
+    # Variables and properties in this class use originals CamelCase variables
+    # names from Microsoft source files for more easy comparison.
+    WinDir = environ.get('WinDir', '')
+    ProgramFiles = environ.get('ProgramFiles', '')
+    ProgramFilesx86 = environ.get('ProgramFiles(x86)', ProgramFiles)
+
+    def __init__(self, registry_info, vc_ver=None):
+        self.ri = registry_info
+        self.pi = self.ri.pi
+
+        self.known_vs_paths = self.find_programdata_vs_vers()
+
+        # Except for VS15+, VC version is aligned with VS version
+        self.vs_ver = self.vc_ver = (
+            vc_ver or self._find_latest_available_vs_ver())
+
+    def _find_latest_available_vs_ver(self):
+        """
+        Find the latest VC version
+
+        Return
+        ------
+        float
+            version
+        """
+        reg_vc_vers = self.find_reg_vs_vers()
+
+        if not (reg_vc_vers or self.known_vs_paths):
+            raise distutils.errors.DistutilsPlatformError(
+                'No Microsoft Visual C++ version found')
+
+        vc_vers = set(reg_vc_vers)
+        vc_vers.update(self.known_vs_paths)
+        return sorted(vc_vers)[-1]
+
+    def find_reg_vs_vers(self):
+        """
+        Find Microsoft Visual Studio versions available in registry.
+
+        Return
+        ------
+        list of float
+            Versions
+        """
+        ms = self.ri.microsoft
+        vckeys = (self.ri.vc, self.ri.vc_for_python, self.ri.vs)
+        vs_vers = []
+        for hkey in self.ri.HKEYS:
+            for key in vckeys:
+                try:
+                    bkey = winreg.OpenKey(hkey, ms(key), 0, winreg.KEY_READ)
+                except (OSError, IOError):
+                    continue
+                subkeys, values, _ = winreg.QueryInfoKey(bkey)
+                for i in range(values):
+                    try:
+                        ver = float(winreg.EnumValue(bkey, i)[0])
+                        if ver not in vs_vers:
+                            vs_vers.append(ver)
+                    except ValueError:
+                        pass
+                for i in range(subkeys):
+                    try:
+                        ver = float(winreg.EnumKey(bkey, i))
+                        if ver not in vs_vers:
+                            vs_vers.append(ver)
+                    except ValueError:
+                        pass
+        return sorted(vs_vers)
+
+    def find_programdata_vs_vers(self):
+        r"""
+        Find Visual studio 2017+ versions from information in
+        "C:\ProgramData\Microsoft\VisualStudio\Packages\_Instances".
+
+        Return
+        ------
+        dict
+            float version as key, path as value.
+        """
+        vs_versions = {}
+        instances_dir = \
+            r'C:\ProgramData\Microsoft\VisualStudio\Packages\_Instances'
+
+        try:
+            hashed_names = listdir(instances_dir)
+
+        except (OSError, IOError):
+            # Directory not exists with all Visual Studio versions
+            return vs_versions
+
+        for name in hashed_names:
+            try:
+                # Get VS installation path from "state.json" file
+                state_path = join(instances_dir, name, 'state.json')
+                with open(state_path, 'rt', encoding='utf-8') as state_file:
+                    state = json.load(state_file)
+                vs_path = state['installationPath']
+
+                # Raises OSError if this VS installation does not contain VC
+                listdir(join(vs_path, r'VC\Tools\MSVC'))
+
+                # Store version and path
+                vs_versions[self._as_float_version(
+                    state['installationVersion'])] = vs_path
+
+            except (OSError, IOError, KeyError):
+                # Skip if "state.json" file is missing or bad format
+                continue
+
+        return vs_versions
+
+    @staticmethod
+    def _as_float_version(version):
+        """
+        Return a string version as a simplified float version (major.minor)
+
+        Parameters
+        ----------
+        version: str
+            Version.
+
+        Return
+        ------
+        float
+            version
+        """
+        return float('.'.join(version.split('.')[:2]))
+
+    @property
+    def VSInstallDir(self):
+        """
+        Microsoft Visual Studio directory.
+
+        Return
+        ------
+        str
+            path
+        """
+        # Default path
+        default = join(self.ProgramFilesx86,
+                       'Microsoft Visual Studio %0.1f' % self.vs_ver)
+
+        # Try to get path from registry, if fail use default path
+        return self.ri.lookup(self.ri.vs, '%0.1f' % self.vs_ver) or default
+
+    @property
+    def VCInstallDir(self):
+        """
+        Microsoft Visual C++ directory.
+
+        Return
+        ------
+        str
+            path
+        """
+        path = self._guess_vc() or self._guess_vc_legacy()
+
+        if not isdir(path):
+            msg = 'Microsoft Visual C++ directory not found'
+            raise distutils.errors.DistutilsPlatformError(msg)
+
+        return path
+
+    def _guess_vc(self):
+        """
+        Locate Visual C++ for VS2017+.
+
+        Return
+        ------
+        str
+            path
+        """
+        if self.vs_ver <= 14.0:
+            return ''
+
+        try:
+            # First search in known VS paths
+            vs_dir = self.known_vs_paths[self.vs_ver]
+        except KeyError:
+            # Else, search with path from registry
+            vs_dir = self.VSInstallDir
+
+        guess_vc = join(vs_dir, r'VC\Tools\MSVC')
+
+        # Subdir with VC exact version as name
+        try:
+            # Update the VC version with real one instead of VS version
+            vc_ver = listdir(guess_vc)[-1]
+            self.vc_ver = self._as_float_version(vc_ver)
+            return join(guess_vc, vc_ver)
+        except (OSError, IOError, IndexError):
+            return ''
+
+    def _guess_vc_legacy(self):
+        """
+        Locate Visual C++ for versions prior to 2017.
+
+        Return
+        ------
+        str
+            path
+        """
+        default = join(self.ProgramFilesx86,
+                       r'Microsoft Visual Studio %0.1f\VC' % self.vs_ver)
+
+        # Try to get "VC++ for Python" path from registry as default path
+        reg_path = join(self.ri.vc_for_python, '%0.1f' % self.vs_ver)
+        python_vc = self.ri.lookup(reg_path, 'installdir')
+        default_vc = join(python_vc, 'VC') if python_vc else default
+
+        # Try to get path from registry, if fail use default path
+        return self.ri.lookup(self.ri.vc, '%0.1f' % self.vs_ver) or default_vc
+
+    @property
+    def WindowsSdkVersion(self):
+        """
+        Microsoft Windows SDK versions for specified MSVC++ version.
+
+        Return
+        ------
+        tuple of str
+            versions
+        """
+        if self.vs_ver <= 9.0:
+            return '7.0', '6.1', '6.0a'
+        elif self.vs_ver == 10.0:
+            return '7.1', '7.0a'
+        elif self.vs_ver == 11.0:
+            return '8.0', '8.0a'
+        elif self.vs_ver == 12.0:
+            return '8.1', '8.1a'
+        elif self.vs_ver >= 14.0:
+            return '10.0', '8.1'
+
+    @property
+    def WindowsSdkLastVersion(self):
+        """
+        Microsoft Windows SDK last version.
+
+        Return
+        ------
+        str
+            version
+        """
+        return self._use_last_dir_name(join(self.WindowsSdkDir, 'lib'))
+
+    @property
+    def WindowsSdkDir(self):
+        """
+        Microsoft Windows SDK directory.
+
+        Return
+        ------
+        str
+            path
+        """
+        sdkdir = ''
+        for ver in self.WindowsSdkVersion:
+            # Try to get it from registry
+            loc = join(self.ri.windows_sdk, 'v%s' % ver)
+            sdkdir = self.ri.lookup(loc, 'installationfolder')
+            if sdkdir:
+                break
+        if not sdkdir or not isdir(sdkdir):
+            # Try to get "VC++ for Python" version from registry
+            path = join(self.ri.vc_for_python, '%0.1f' % self.vc_ver)
+            install_base = self.ri.lookup(path, 'installdir')
+            if install_base:
+                sdkdir = join(install_base, 'WinSDK')
+        if not sdkdir or not isdir(sdkdir):
+            # If fail, use default new path
+            for ver in self.WindowsSdkVersion:
+                intver = ver[:ver.rfind('.')]
+                path = r'Microsoft SDKs\Windows Kits\%s' % intver
+                d = join(self.ProgramFiles, path)
+                if isdir(d):
+                    sdkdir = d
+        if not sdkdir or not isdir(sdkdir):
+            # If fail, use default old path
+            for ver in self.WindowsSdkVersion:
+                path = r'Microsoft SDKs\Windows\v%s' % ver
+                d = join(self.ProgramFiles, path)
+                if isdir(d):
+                    sdkdir = d
+        if not sdkdir:
+            # If fail, use Platform SDK
+            sdkdir = join(self.VCInstallDir, 'PlatformSDK')
+        return sdkdir
+
+    @property
+    def WindowsSDKExecutablePath(self):
+        """
+        Microsoft Windows SDK executable directory.
+
+        Return
+        ------
+        str
+            path
+        """
+        # Find WinSDK NetFx Tools registry dir name
+        if self.vs_ver <= 11.0:
+            netfxver = 35
+            arch = ''
+        else:
+            netfxver = 40
+            hidex86 = True if self.vs_ver <= 12.0 else False
+            arch = self.pi.current_dir(x64=True, hidex86=hidex86)
+        fx = 'WinSDK-NetFx%dTools%s' % (netfxver, arch.replace('\\', '-'))
+
+        # list all possibles registry paths
+        regpaths = []
+        if self.vs_ver >= 14.0:
+            for ver in self.NetFxSdkVersion:
+                regpaths += [join(self.ri.netfx_sdk, ver, fx)]
+
+        for ver in self.WindowsSdkVersion:
+            regpaths += [join(self.ri.windows_sdk, 'v%sA' % ver, fx)]
+
+        # Return installation folder from the more recent path
+        for path in regpaths:
+            execpath = self.ri.lookup(path, 'installationfolder')
+            if execpath:
+                return execpath
+
+    @property
+    def FSharpInstallDir(self):
+        """
+        Microsoft Visual F# directory.
+
+        Return
+        ------
+        str
+            path
+        """
+        path = join(self.ri.visualstudio, r'%0.1f\Setup\F#' % self.vs_ver)
+        return self.ri.lookup(path, 'productdir') or ''
+
+    @property
+    def UniversalCRTSdkDir(self):
+        """
+        Microsoft Universal CRT SDK directory.
+
+        Return
+        ------
+        str
+            path
+        """
+        # Set Kit Roots versions for specified MSVC++ version
+        vers = ('10', '81') if self.vs_ver >= 14.0 else ()
+
+        # Find path of the more recent Kit
+        for ver in vers:
+            sdkdir = self.ri.lookup(self.ri.windows_kits_roots,
+                                    'kitsroot%s' % ver)
+            if sdkdir:
+                return sdkdir or ''
+
+    @property
+    def UniversalCRTSdkLastVersion(self):
+        """
+        Microsoft Universal C Runtime SDK last version.
+
+        Return
+        ------
+        str
+            version
+        """
+        return self._use_last_dir_name(join(self.UniversalCRTSdkDir, 'lib'))
+
+    @property
+    def NetFxSdkVersion(self):
+        """
+        Microsoft .NET Framework SDK versions.
+
+        Return
+        ------
+        tuple of str
+            versions
+        """
+        # Set FxSdk versions for specified VS version
+        return (('4.7.2', '4.7.1', '4.7',
+                 '4.6.2', '4.6.1', '4.6',
+                 '4.5.2', '4.5.1', '4.5')
+                if self.vs_ver >= 14.0 else ())
+
+    @property
+    def NetFxSdkDir(self):
+        """
+        Microsoft .NET Framework SDK directory.
+
+        Return
+        ------
+        str
+            path
+        """
+        sdkdir = ''
+        for ver in self.NetFxSdkVersion:
+            loc = join(self.ri.netfx_sdk, ver)
+            sdkdir = self.ri.lookup(loc, 'kitsinstallationfolder')
+            if sdkdir:
+                break
+        return sdkdir
+
+    @property
+    def FrameworkDir32(self):
+        """
+        Microsoft .NET Framework 32bit directory.
+
+        Return
+        ------
+        str
+            path
+        """
+        # Default path
+        guess_fw = join(self.WinDir, r'Microsoft.NET\Framework')
+
+        # Try to get path from registry, if fail use default path
+        return self.ri.lookup(self.ri.vc, 'frameworkdir32') or guess_fw
+
+    @property
+    def FrameworkDir64(self):
+        """
+        Microsoft .NET Framework 64bit directory.
+
+        Return
+        ------
+        str
+            path
+        """
+        # Default path
+        guess_fw = join(self.WinDir, r'Microsoft.NET\Framework64')
+
+        # Try to get path from registry, if fail use default path
+        return self.ri.lookup(self.ri.vc, 'frameworkdir64') or guess_fw
+
+    @property
+    def FrameworkVersion32(self):
+        """
+        Microsoft .NET Framework 32bit versions.
+
+        Return
+        ------
+        tuple of str
+            versions
+        """
+        return self._find_dot_net_versions(32)
+
+    @property
+    def FrameworkVersion64(self):
+        """
+        Microsoft .NET Framework 64bit versions.
+
+        Return
+        ------
+        tuple of str
+            versions
+        """
+        return self._find_dot_net_versions(64)
+
+    def _find_dot_net_versions(self, bits):
+        """
+        Find Microsoft .NET Framework versions.
+
+        Parameters
+        ----------
+        bits: int
+            Platform number of bits: 32 or 64.
+
+        Return
+        ------
+        tuple of str
+            versions
+        """
+        # Find actual .NET version in registry
+        reg_ver = self.ri.lookup(self.ri.vc, 'frameworkver%d' % bits)
+        dot_net_dir = getattr(self, 'FrameworkDir%d' % bits)
+        ver = reg_ver or self._use_last_dir_name(dot_net_dir, 'v') or ''
+
+        # Set .NET versions for specified MSVC++ version
+        if self.vs_ver >= 12.0:
+            return ver, 'v4.0'
+        elif self.vs_ver >= 10.0:
+            return 'v4.0.30319' if ver.lower()[:2] != 'v4' else ver, 'v3.5'
+        elif self.vs_ver == 9.0:
+            return 'v3.5', 'v2.0.50727'
+        elif self.vs_ver == 8.0:
+            return 'v3.0', 'v2.0.50727'
+
+    @staticmethod
+    def _use_last_dir_name(path, prefix=''):
+        """
+        Return name of the last dir in path or '' if no dir found.
+
+        Parameters
+        ----------
+        path: str
+            Use dirs in this path
+        prefix: str
+            Use only dirs starting by this prefix
+
+        Return
+        ------
+        str
+            name
+        """
+        matching_dirs = (
+            dir_name
+            for dir_name in reversed(listdir(path))
+            if isdir(join(path, dir_name)) and
+            dir_name.startswith(prefix)
+        )
+        return next(matching_dirs, None) or ''
+
+
+class EnvironmentInfo:
+    """
+    Return environment variables for specified Microsoft Visual C++ version
+    and platform : Lib, Include, Path and libpath.
+
+    This function is compatible with Microsoft Visual C++ 9.0 to 14.X.
+
+    Script created by analysing Microsoft environment configuration files like
+    "vcvars[...].bat", "SetEnv.Cmd", "vcbuildtools.bat", ...
+
+    Parameters
+    ----------
+    arch: str
+        Target architecture.
+    vc_ver: float
+        Required Microsoft Visual C++ version. If not set, autodetect the last
+        version.
+    vc_min_ver: float
+        Minimum Microsoft Visual C++ version.
+    """
+
+    # Variables and properties in this class use originals CamelCase variables
+    # names from Microsoft source files for more easy comparison.
+
+    def __init__(self, arch, vc_ver=None, vc_min_ver=0):
+        self.pi = PlatformInfo(arch)
+        self.ri = RegistryInfo(self.pi)
+        self.si = SystemInfo(self.ri, vc_ver)
+
+        if self.vc_ver < vc_min_ver:
+            err = 'No suitable Microsoft Visual C++ version found'
+            raise distutils.errors.DistutilsPlatformError(err)
+
+    @property
+    def vs_ver(self):
+        """
+        Microsoft Visual Studio.
+
+        Return
+        ------
+        float
+            version
+        """
+        return self.si.vs_ver
+
+    @property
+    def vc_ver(self):
+        """
+        Microsoft Visual C++ version.
+
+        Return
+        ------
+        float
+            version
+        """
+        return self.si.vc_ver
+
+    @property
+    def VSTools(self):
+        """
+        Microsoft Visual Studio Tools.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        paths = [r'Common7\IDE', r'Common7\Tools']
+
+        if self.vs_ver >= 14.0:
+            arch_subdir = self.pi.current_dir(hidex86=True, x64=True)
+            paths += [r'Common7\IDE\CommonExtensions\Microsoft\TestWindow']
+            paths += [r'Team Tools\Performance Tools']
+            paths += [r'Team Tools\Performance Tools%s' % arch_subdir]
+
+        return [join(self.si.VSInstallDir, path) for path in paths]
+
+    @property
+    def VCIncludes(self):
+        """
+        Microsoft Visual C++ & Microsoft Foundation Class Includes.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        return [join(self.si.VCInstallDir, 'Include'),
+                join(self.si.VCInstallDir, r'ATLMFC\Include')]
+
+    @property
+    def VCLibraries(self):
+        """
+        Microsoft Visual C++ & Microsoft Foundation Class Libraries.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        if self.vs_ver >= 15.0:
+            arch_subdir = self.pi.target_dir(x64=True)
+        else:
+            arch_subdir = self.pi.target_dir(hidex86=True)
+        paths = ['Lib%s' % arch_subdir, r'ATLMFC\Lib%s' % arch_subdir]
+
+        if self.vs_ver >= 14.0:
+            paths += [r'Lib\store%s' % arch_subdir]
+
+        return [join(self.si.VCInstallDir, path) for path in paths]
+
+    @property
+    def VCStoreRefs(self):
+        """
+        Microsoft Visual C++ store references Libraries.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        if self.vs_ver < 14.0:
+            return []
+        return [join(self.si.VCInstallDir, r'Lib\store\references')]
+
+    @property
+    def VCTools(self):
+        """
+        Microsoft Visual C++ Tools.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        si = self.si
+        tools = [join(si.VCInstallDir, 'VCPackages')]
+
+        forcex86 = True if self.vs_ver <= 10.0 else False
+        arch_subdir = self.pi.cross_dir(forcex86)
+        if arch_subdir:
+            tools += [join(si.VCInstallDir, 'Bin%s' % arch_subdir)]
+
+        if self.vs_ver == 14.0:
+            path = 'Bin%s' % self.pi.current_dir(hidex86=True)
+            tools += [join(si.VCInstallDir, path)]
+
+        elif self.vs_ver >= 15.0:
+            host_dir = (r'bin\HostX86%s' if self.pi.current_is_x86() else
+                        r'bin\HostX64%s')
+            tools += [join(
+                si.VCInstallDir, host_dir % self.pi.target_dir(x64=True))]
+
+            if self.pi.current_cpu != self.pi.target_cpu:
+                tools += [join(
+                    si.VCInstallDir, host_dir % self.pi.current_dir(x64=True))]
+
+        else:
+            tools += [join(si.VCInstallDir, 'Bin')]
+
+        return tools
+
+    @property
+    def OSLibraries(self):
+        """
+        Microsoft Windows SDK Libraries.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        if self.vs_ver <= 10.0:
+            arch_subdir = self.pi.target_dir(hidex86=True, x64=True)
+            return [join(self.si.WindowsSdkDir, 'Lib%s' % arch_subdir)]
+
+        else:
+            arch_subdir = self.pi.target_dir(x64=True)
+            lib = join(self.si.WindowsSdkDir, 'lib')
+            libver = self._sdk_subdir
+            return [join(lib, '%sum%s' % (libver, arch_subdir))]
+
+    @property
+    def OSIncludes(self):
+        """
+        Microsoft Windows SDK Include.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        include = join(self.si.WindowsSdkDir, 'include')
+
+        if self.vs_ver <= 10.0:
+            return [include, join(include, 'gl')]
+
+        else:
+            if self.vs_ver >= 14.0:
+                sdkver = self._sdk_subdir
+            else:
+                sdkver = ''
+            return [join(include, '%sshared' % sdkver),
+                    join(include, '%sum' % sdkver),
+                    join(include, '%swinrt' % sdkver)]
+
+    @property
+    def OSLibpath(self):
+        """
+        Microsoft Windows SDK Libraries Paths.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        ref = join(self.si.WindowsSdkDir, 'References')
+        libpath = []
+
+        if self.vs_ver <= 9.0:
+            libpath += self.OSLibraries
+
+        if self.vs_ver >= 11.0:
+            libpath += [join(ref, r'CommonConfiguration\Neutral')]
+
+        if self.vs_ver >= 14.0:
+            libpath += [
+                ref,
+                join(self.si.WindowsSdkDir, 'UnionMetadata'),
+                join(
+                    ref, 'Windows.Foundation.UniversalApiContract', '1.0.0.0'),
+                join(ref, 'Windows.Foundation.FoundationContract', '1.0.0.0'),
+                join(
+                    ref, 'Windows.Networking.Connectivity.WwanContract',
+                    '1.0.0.0'),
+                join(
+                    self.si.WindowsSdkDir, 'ExtensionSDKs', 'Microsoft.VCLibs',
+                    '%0.1f' % self.vs_ver, 'References', 'CommonConfiguration',
+                    'neutral'),
+            ]
+        return libpath
+
+    @property
+    def SdkTools(self):
+        """
+        Microsoft Windows SDK Tools.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        return list(self._sdk_tools())
+
+    def _sdk_tools(self):
+        """
+        Microsoft Windows SDK Tools paths generator.
+
+        Return
+        ------
+        generator of str
+            paths
+        """
+        if self.vs_ver < 15.0:
+            bin_dir = 'Bin' if self.vs_ver <= 11.0 else r'Bin\x86'
+            yield join(self.si.WindowsSdkDir, bin_dir)
+
+        if not self.pi.current_is_x86():
+            arch_subdir = self.pi.current_dir(x64=True)
+            path = 'Bin%s' % arch_subdir
+            yield join(self.si.WindowsSdkDir, path)
+
+        if self.vs_ver in (10.0, 11.0):
+            if self.pi.target_is_x86():
+                arch_subdir = ''
+            else:
+                arch_subdir = self.pi.current_dir(hidex86=True, x64=True)
+            path = r'Bin\NETFX 4.0 Tools%s' % arch_subdir
+            yield join(self.si.WindowsSdkDir, path)
+
+        elif self.vs_ver >= 15.0:
+            path = join(self.si.WindowsSdkDir, 'Bin')
+            arch_subdir = self.pi.current_dir(x64=True)
+            sdkver = self.si.WindowsSdkLastVersion
+            yield join(path, '%s%s' % (sdkver, arch_subdir))
+
+        if self.si.WindowsSDKExecutablePath:
+            yield self.si.WindowsSDKExecutablePath
+
+    @property
+    def _sdk_subdir(self):
+        """
+        Microsoft Windows SDK version subdir.
+
+        Return
+        ------
+        str
+            subdir
+        """
+        ucrtver = self.si.WindowsSdkLastVersion
+        return ('%s\\' % ucrtver) if ucrtver else ''
+
+    @property
+    def SdkSetup(self):
+        """
+        Microsoft Windows SDK Setup.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        if self.vs_ver > 9.0:
+            return []
+
+        return [join(self.si.WindowsSdkDir, 'Setup')]
+
+    @property
+    def FxTools(self):
+        """
+        Microsoft .NET Framework Tools.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        pi = self.pi
+        si = self.si
+
+        if self.vs_ver <= 10.0:
+            include32 = True
+            include64 = not pi.target_is_x86() and not pi.current_is_x86()
+        else:
+            include32 = pi.target_is_x86() or pi.current_is_x86()
+            include64 = pi.current_cpu == 'amd64' or pi.target_cpu == 'amd64'
+
+        tools = []
+        if include32:
+            tools += [join(si.FrameworkDir32, ver)
+                      for ver in si.FrameworkVersion32]
+        if include64:
+            tools += [join(si.FrameworkDir64, ver)
+                      for ver in si.FrameworkVersion64]
+        return tools
+
+    @property
+    def NetFxSDKLibraries(self):
+        """
+        Microsoft .Net Framework SDK Libraries.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        if self.vs_ver < 14.0 or not self.si.NetFxSdkDir:
+            return []
+
+        arch_subdir = self.pi.target_dir(x64=True)
+        return [join(self.si.NetFxSdkDir, r'lib\um%s' % arch_subdir)]
+
+    @property
+    def NetFxSDKIncludes(self):
+        """
+        Microsoft .Net Framework SDK Includes.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        if self.vs_ver < 14.0 or not self.si.NetFxSdkDir:
+            return []
+
+        return [join(self.si.NetFxSdkDir, r'include\um')]
+
+    @property
+    def VsTDb(self):
+        """
+        Microsoft Visual Studio Team System Database.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        return [join(self.si.VSInstallDir, r'VSTSDB\Deploy')]
+
+    @property
+    def MSBuild(self):
+        """
+        Microsoft Build Engine.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        if self.vs_ver < 12.0:
+            return []
+        elif self.vs_ver < 15.0:
+            base_path = self.si.ProgramFilesx86
+            arch_subdir = self.pi.current_dir(hidex86=True)
+        else:
+            base_path = self.si.VSInstallDir
+            arch_subdir = ''
+
+        path = r'MSBuild\%0.1f\bin%s' % (self.vs_ver, arch_subdir)
+        build = [join(base_path, path)]
+
+        if self.vs_ver >= 15.0:
+            # Add Roslyn C# & Visual Basic Compiler
+            build += [join(base_path, path, 'Roslyn')]
+
+        return build
+
+    @property
+    def HTMLHelpWorkshop(self):
+        """
+        Microsoft HTML Help Workshop.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        if self.vs_ver < 11.0:
+            return []
+
+        return [join(self.si.ProgramFilesx86, 'HTML Help Workshop')]
+
+    @property
+    def UCRTLibraries(self):
+        """
+        Microsoft Universal C Runtime SDK Libraries.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        if self.vs_ver < 14.0:
+            return []
+
+        arch_subdir = self.pi.target_dir(x64=True)
+        lib = join(self.si.UniversalCRTSdkDir, 'lib')
+        ucrtver = self._ucrt_subdir
+        return [join(lib, '%sucrt%s' % (ucrtver, arch_subdir))]
+
+    @property
+    def UCRTIncludes(self):
+        """
+        Microsoft Universal C Runtime SDK Include.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        if self.vs_ver < 14.0:
+            return []
+
+        include = join(self.si.UniversalCRTSdkDir, 'include')
+        return [join(include, '%sucrt' % self._ucrt_subdir)]
+
+    @property
+    def _ucrt_subdir(self):
+        """
+        Microsoft Universal C Runtime SDK version subdir.
+
+        Return
+        ------
+        str
+            subdir
+        """
+        ucrtver = self.si.UniversalCRTSdkLastVersion
+        return ('%s\\' % ucrtver) if ucrtver else ''
+
+    @property
+    def FSharp(self):
+        """
+        Microsoft Visual F#.
+
+        Return
+        ------
+        list of str
+            paths
+        """
+        if 11.0 > self.vs_ver > 12.0:
+            return []
+
+        return [self.si.FSharpInstallDir]
+
+    @property
+    def VCRuntimeRedist(self):
+        """
+        Microsoft Visual C++ runtime redistributable dll.
+
+        Return
+        ------
+        str
+            path
+        """
+        vcruntime = 'vcruntime%d0.dll' % self.vc_ver
+        arch_subdir = self.pi.target_dir(x64=True).strip('\\')
+
+        # Installation prefixes candidates
+        prefixes = []
+        tools_path = self.si.VCInstallDir
+        redist_path = dirname(tools_path.replace(r'\Tools', r'\Redist'))
+        if isdir(redist_path):
+            # Redist version may not be exactly the same as tools
+            redist_path = join(redist_path, listdir(redist_path)[-1])
+            prefixes += [redist_path, join(redist_path, 'onecore')]
+
+        prefixes += [join(tools_path, 'redist')]  # VS14 legacy path
+
+        # CRT directory
+        crt_dirs = ('Microsoft.VC%d.CRT' % (self.vc_ver * 10),
+                    # Sometime store in directory with VS version instead of VC
+                    'Microsoft.VC%d.CRT' % (int(self.vs_ver) * 10))
+
+        # vcruntime path
+        for prefix, crt_dir in itertools.product(prefixes, crt_dirs):
+            path = join(prefix, arch_subdir, crt_dir, vcruntime)
+            if isfile(path):
+                return path
+
+    def return_env(self, exists=True):
+        """
+        Return environment dict.
+
+        Parameters
+        ----------
+        exists: bool
+            It True, only return existing paths.
+
+        Return
+        ------
+        dict
+            environment
+        """
+        env = dict(
+            include=self._build_paths('include',
+                                      [self.VCIncludes,
+                                       self.OSIncludes,
+                                       self.UCRTIncludes,
+                                       self.NetFxSDKIncludes],
+                                      exists),
+            lib=self._build_paths('lib',
+                                  [self.VCLibraries,
+                                   self.OSLibraries,
+                                   self.FxTools,
+                                   self.UCRTLibraries,
+                                   self.NetFxSDKLibraries],
+                                  exists),
+            libpath=self._build_paths('libpath',
+                                      [self.VCLibraries,
+                                       self.FxTools,
+                                       self.VCStoreRefs,
+                                       self.OSLibpath],
+                                      exists),
+            path=self._build_paths('path',
+                                   [self.VCTools,
+                                    self.VSTools,
+                                    self.VsTDb,
+                                    self.SdkTools,
+                                    self.SdkSetup,
+                                    self.FxTools,
+                                    self.MSBuild,
+                                    self.HTMLHelpWorkshop,
+                                    self.FSharp],
+                                   exists),
+        )
+        if self.vs_ver >= 14 and isfile(self.VCRuntimeRedist):
+            env['py_vcruntime_redist'] = self.VCRuntimeRedist
+        return env
+
+    def _build_paths(self, name, spec_path_lists, exists):
+        """
+        Given an environment variable name and specified paths,
+        return a pathsep-separated string of paths containing
+        unique, extant, directories from those paths and from
+        the environment variable. Raise an error if no paths
+        are resolved.
+
+        Parameters
+        ----------
+        name: str
+            Environment variable name
+        spec_path_lists: list of str
+            Paths
+        exists: bool
+            It True, only return existing paths.
+
+        Return
+        ------
+        str
+            Pathsep-separated paths
+        """
+        # flatten spec_path_lists
+        spec_paths = itertools.chain.from_iterable(spec_path_lists)
+        env_paths = environ.get(name, '').split(pathsep)
+        paths = itertools.chain(spec_paths, env_paths)
+        extant_paths = list(filter(isdir, paths)) if exists else paths
+        if not extant_paths:
+            msg = "%s environment variable is empty" % name.upper()
+            raise distutils.errors.DistutilsPlatformError(msg)
+        unique_paths = self._unique_everseen(extant_paths)
+        return pathsep.join(unique_paths)
+
+    # from Python docs
+    @staticmethod
+    def _unique_everseen(iterable, key=None):
+        """
+        List unique elements, preserving order.
+        Remember all elements ever seen.
+
+        _unique_everseen('AAAABBBCCDAABBB') --> A B C D
+
+        _unique_everseen('ABBCcAD', str.lower) --> A B C D
+        """
+        seen = set()
+        seen_add = seen.add
+        if key is None:
+            for element in filterfalse(seen.__contains__, iterable):
+                seen_add(element)
+                yield element
+        else:
+            for element in iterable:
+                k = key(element)
+                if k not in seen:
+                    seen_add(k)
+                    yield element