--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/python3.8/site-packages/setuptools/command/build_ext.py	Mon Jul 27 03:47:31 2020 -0400
@@ -0,0 +1,330 @@
+import os
+import sys
+import itertools
+from distutils.command.build_ext import build_ext as _du_build_ext
+from distutils.file_util import copy_file
+from distutils.ccompiler import new_compiler
+from distutils.sysconfig import customize_compiler, get_config_var
+from distutils.errors import DistutilsError
+from distutils import log
+
+from setuptools.extension import Library
+from setuptools.extern import six
+
+if six.PY2:
+    import imp
+
+    EXTENSION_SUFFIXES = [
+        s for s, _, tp in imp.get_suffixes() if tp == imp.C_EXTENSION]
+else:
+    from importlib.machinery import EXTENSION_SUFFIXES
+
+try:
+    # Attempt to use Cython for building extensions, if available
+    from Cython.Distutils.build_ext import build_ext as _build_ext
+    # Additionally, assert that the compiler module will load
+    # also. Ref #1229.
+    __import__('Cython.Compiler.Main')
+except ImportError:
+    _build_ext = _du_build_ext
+
+# make sure _config_vars is initialized
+get_config_var("LDSHARED")
+from distutils.sysconfig import _config_vars as _CONFIG_VARS  # noqa
+
+
+def _customize_compiler_for_shlib(compiler):
+    if sys.platform == "darwin":
+        # building .dylib requires additional compiler flags on OSX; here we
+        # temporarily substitute the pyconfig.h variables so that distutils'
+        # 'customize_compiler' uses them before we build the shared libraries.
+        tmp = _CONFIG_VARS.copy()
+        try:
+            # XXX Help!  I don't have any idea whether these are right...
+            _CONFIG_VARS['LDSHARED'] = (
+                "gcc -Wl,-x -dynamiclib -undefined dynamic_lookup")
+            _CONFIG_VARS['CCSHARED'] = " -dynamiclib"
+            _CONFIG_VARS['SO'] = ".dylib"
+            customize_compiler(compiler)
+        finally:
+            _CONFIG_VARS.clear()
+            _CONFIG_VARS.update(tmp)
+    else:
+        customize_compiler(compiler)
+
+
+have_rtld = False
+use_stubs = False
+libtype = 'shared'
+
+if sys.platform == "darwin":
+    use_stubs = True
+elif os.name != 'nt':
+    try:
+        import dl
+        use_stubs = have_rtld = hasattr(dl, 'RTLD_NOW')
+    except ImportError:
+        pass
+
+
+def if_dl(s):
+    return s if have_rtld else ''
+
+
+def get_abi3_suffix():
+    """Return the file extension for an abi3-compliant Extension()"""
+    for suffix in EXTENSION_SUFFIXES:
+        if '.abi3' in suffix:  # Unix
+            return suffix
+        elif suffix == '.pyd':  # Windows
+            return suffix
+
+
+class build_ext(_build_ext):
+    def run(self):
+        """Build extensions in build directory, then copy if --inplace"""
+        old_inplace, self.inplace = self.inplace, 0
+        _build_ext.run(self)
+        self.inplace = old_inplace
+        if old_inplace:
+            self.copy_extensions_to_source()
+
+    def copy_extensions_to_source(self):
+        build_py = self.get_finalized_command('build_py')
+        for ext in self.extensions:
+            fullname = self.get_ext_fullname(ext.name)
+            filename = self.get_ext_filename(fullname)
+            modpath = fullname.split('.')
+            package = '.'.join(modpath[:-1])
+            package_dir = build_py.get_package_dir(package)
+            dest_filename = os.path.join(package_dir,
+                                         os.path.basename(filename))
+            src_filename = os.path.join(self.build_lib, filename)
+
+            # Always copy, even if source is older than destination, to ensure
+            # that the right extensions for the current Python/platform are
+            # used.
+            copy_file(
+                src_filename, dest_filename, verbose=self.verbose,
+                dry_run=self.dry_run
+            )
+            if ext._needs_stub:
+                self.write_stub(package_dir or os.curdir, ext, True)
+
+    def get_ext_filename(self, fullname):
+        filename = _build_ext.get_ext_filename(self, fullname)
+        if fullname in self.ext_map:
+            ext = self.ext_map[fullname]
+            use_abi3 = (
+                not six.PY2
+                and getattr(ext, 'py_limited_api')
+                and get_abi3_suffix()
+            )
+            if use_abi3:
+                so_ext = get_config_var('EXT_SUFFIX')
+                filename = filename[:-len(so_ext)]
+                filename = filename + get_abi3_suffix()
+            if isinstance(ext, Library):
+                fn, ext = os.path.splitext(filename)
+                return self.shlib_compiler.library_filename(fn, libtype)
+            elif use_stubs and ext._links_to_dynamic:
+                d, fn = os.path.split(filename)
+                return os.path.join(d, 'dl-' + fn)
+        return filename
+
+    def initialize_options(self):
+        _build_ext.initialize_options(self)
+        self.shlib_compiler = None
+        self.shlibs = []
+        self.ext_map = {}
+
+    def finalize_options(self):
+        _build_ext.finalize_options(self)
+        self.extensions = self.extensions or []
+        self.check_extensions_list(self.extensions)
+        self.shlibs = [ext for ext in self.extensions
+                       if isinstance(ext, Library)]
+        if self.shlibs:
+            self.setup_shlib_compiler()
+        for ext in self.extensions:
+            ext._full_name = self.get_ext_fullname(ext.name)
+        for ext in self.extensions:
+            fullname = ext._full_name
+            self.ext_map[fullname] = ext
+
+            # distutils 3.1 will also ask for module names
+            # XXX what to do with conflicts?
+            self.ext_map[fullname.split('.')[-1]] = ext
+
+            ltd = self.shlibs and self.links_to_dynamic(ext) or False
+            ns = ltd and use_stubs and not isinstance(ext, Library)
+            ext._links_to_dynamic = ltd
+            ext._needs_stub = ns
+            filename = ext._file_name = self.get_ext_filename(fullname)
+            libdir = os.path.dirname(os.path.join(self.build_lib, filename))
+            if ltd and libdir not in ext.library_dirs:
+                ext.library_dirs.append(libdir)
+            if ltd and use_stubs and os.curdir not in ext.runtime_library_dirs:
+                ext.runtime_library_dirs.append(os.curdir)
+
+    def setup_shlib_compiler(self):
+        compiler = self.shlib_compiler = new_compiler(
+            compiler=self.compiler, dry_run=self.dry_run, force=self.force
+        )
+        _customize_compiler_for_shlib(compiler)
+
+        if self.include_dirs is not None:
+            compiler.set_include_dirs(self.include_dirs)
+        if self.define is not None:
+            # 'define' option is a list of (name,value) tuples
+            for (name, value) in self.define:
+                compiler.define_macro(name, value)
+        if self.undef is not None:
+            for macro in self.undef:
+                compiler.undefine_macro(macro)
+        if self.libraries is not None:
+            compiler.set_libraries(self.libraries)
+        if self.library_dirs is not None:
+            compiler.set_library_dirs(self.library_dirs)
+        if self.rpath is not None:
+            compiler.set_runtime_library_dirs(self.rpath)
+        if self.link_objects is not None:
+            compiler.set_link_objects(self.link_objects)
+
+        # hack so distutils' build_extension() builds a library instead
+        compiler.link_shared_object = link_shared_object.__get__(compiler)
+
+    def get_export_symbols(self, ext):
+        if isinstance(ext, Library):
+            return ext.export_symbols
+        return _build_ext.get_export_symbols(self, ext)
+
+    def build_extension(self, ext):
+        ext._convert_pyx_sources_to_lang()
+        _compiler = self.compiler
+        try:
+            if isinstance(ext, Library):
+                self.compiler = self.shlib_compiler
+            _build_ext.build_extension(self, ext)
+            if ext._needs_stub:
+                cmd = self.get_finalized_command('build_py').build_lib
+                self.write_stub(cmd, ext)
+        finally:
+            self.compiler = _compiler
+
+    def links_to_dynamic(self, ext):
+        """Return true if 'ext' links to a dynamic lib in the same package"""
+        # XXX this should check to ensure the lib is actually being built
+        # XXX as dynamic, and not just using a locally-found version or a
+        # XXX static-compiled version
+        libnames = dict.fromkeys([lib._full_name for lib in self.shlibs])
+        pkg = '.'.join(ext._full_name.split('.')[:-1] + [''])
+        return any(pkg + libname in libnames for libname in ext.libraries)
+
+    def get_outputs(self):
+        return _build_ext.get_outputs(self) + self.__get_stubs_outputs()
+
+    def __get_stubs_outputs(self):
+        # assemble the base name for each extension that needs a stub
+        ns_ext_bases = (
+            os.path.join(self.build_lib, *ext._full_name.split('.'))
+            for ext in self.extensions
+            if ext._needs_stub
+        )
+        # pair each base with the extension
+        pairs = itertools.product(ns_ext_bases, self.__get_output_extensions())
+        return list(base + fnext for base, fnext in pairs)
+
+    def __get_output_extensions(self):
+        yield '.py'
+        yield '.pyc'
+        if self.get_finalized_command('build_py').optimize:
+            yield '.pyo'
+
+    def write_stub(self, output_dir, ext, compile=False):
+        log.info("writing stub loader for %s to %s", ext._full_name,
+                 output_dir)
+        stub_file = (os.path.join(output_dir, *ext._full_name.split('.')) +
+                     '.py')
+        if compile and os.path.exists(stub_file):
+            raise DistutilsError(stub_file + " already exists! Please delete.")
+        if not self.dry_run:
+            f = open(stub_file, 'w')
+            f.write(
+                '\n'.join([
+                    "def __bootstrap__():",
+                    "   global __bootstrap__, __file__, __loader__",
+                    "   import sys, os, pkg_resources, imp" + if_dl(", dl"),
+                    "   __file__ = pkg_resources.resource_filename"
+                    "(__name__,%r)"
+                    % os.path.basename(ext._file_name),
+                    "   del __bootstrap__",
+                    "   if '__loader__' in globals():",
+                    "       del __loader__",
+                    if_dl("   old_flags = sys.getdlopenflags()"),
+                    "   old_dir = os.getcwd()",
+                    "   try:",
+                    "     os.chdir(os.path.dirname(__file__))",
+                    if_dl("     sys.setdlopenflags(dl.RTLD_NOW)"),
+                    "     imp.load_dynamic(__name__,__file__)",
+                    "   finally:",
+                    if_dl("     sys.setdlopenflags(old_flags)"),
+                    "     os.chdir(old_dir)",
+                    "__bootstrap__()",
+                    ""  # terminal \n
+                ])
+            )
+            f.close()
+        if compile:
+            from distutils.util import byte_compile
+
+            byte_compile([stub_file], optimize=0,
+                         force=True, dry_run=self.dry_run)
+            optimize = self.get_finalized_command('install_lib').optimize
+            if optimize > 0:
+                byte_compile([stub_file], optimize=optimize,
+                             force=True, dry_run=self.dry_run)
+            if os.path.exists(stub_file) and not self.dry_run:
+                os.unlink(stub_file)
+
+
+if use_stubs or os.name == 'nt':
+    # Build shared libraries
+    #
+    def link_shared_object(
+            self, objects, output_libname, output_dir=None, libraries=None,
+            library_dirs=None, runtime_library_dirs=None, export_symbols=None,
+            debug=0, extra_preargs=None, extra_postargs=None, build_temp=None,
+            target_lang=None):
+        self.link(
+            self.SHARED_LIBRARY, objects, output_libname,
+            output_dir, libraries, library_dirs, runtime_library_dirs,
+            export_symbols, debug, extra_preargs, extra_postargs,
+            build_temp, target_lang
+        )
+else:
+    # Build static libraries everywhere else
+    libtype = 'static'
+
+    def link_shared_object(
+            self, objects, output_libname, output_dir=None, libraries=None,
+            library_dirs=None, runtime_library_dirs=None, export_symbols=None,
+            debug=0, extra_preargs=None, extra_postargs=None, build_temp=None,
+            target_lang=None):
+        # XXX we need to either disallow these attrs on Library instances,
+        # or warn/abort here if set, or something...
+        # libraries=None, library_dirs=None, runtime_library_dirs=None,
+        # export_symbols=None, extra_preargs=None, extra_postargs=None,
+        # build_temp=None
+
+        assert output_dir is None  # distutils build_ext doesn't pass this
+        output_dir, filename = os.path.split(output_libname)
+        basename, ext = os.path.splitext(filename)
+        if self.library_filename("x").startswith('lib'):
+            # strip 'lib' prefix; this is kludgy if some platform uses
+            # a different prefix
+            basename = basename[3:]
+
+        self.create_static_lib(
+            objects, basename, output_dir, debug, target_lang
+        )