diff --git a/newsfragments/4538.feature.rst b/newsfragments/4538.feature.rst
new file mode 100644
index 0000000000..9c36ad5209
--- /dev/null
+++ b/newsfragments/4538.feature.rst
@@ -0,0 +1 @@
+Merged with distutils@d7ffdb9c7 including: Support for Pathlike objects in data files and extensions (pypa/distutils#272, pypa/distutils#237), native support for C++ compilers (pypa/distuils#228) and removed unused get_msvcr() (pypa/distutils#274).
diff --git a/setuptools/_distutils/_collections.py b/setuptools/_distutils/_collections.py
index d11a83467c..863030b3cf 100644
--- a/setuptools/_distutils/_collections.py
+++ b/setuptools/_distutils/_collections.py
@@ -1,11 +1,7 @@
 from __future__ import annotations
 
 import collections
-import functools
 import itertools
-import operator
-from collections.abc import Mapping
-from typing import Any
 
 
 # from jaraco.collections 3.5.1
@@ -60,144 +56,3 @@ def __contains__(self, other):
 
     def __len__(self):
         return len(list(iter(self)))
-
-
-# from jaraco.collections 5.0.1
-class RangeMap(dict):
-    """
-    A dictionary-like object that uses the keys as bounds for a range.
-    Inclusion of the value for that range is determined by the
-    key_match_comparator, which defaults to less-than-or-equal.
-    A value is returned for a key if it is the first key that matches in
-    the sorted list of keys.
-
-    One may supply keyword parameters to be passed to the sort function used
-    to sort keys (i.e. key, reverse) as sort_params.
-
-    Create a map that maps 1-3 -> 'a', 4-6 -> 'b'
-
-    >>> r = RangeMap({3: 'a', 6: 'b'})  # boy, that was easy
-    >>> r[1], r[2], r[3], r[4], r[5], r[6]
-    ('a', 'a', 'a', 'b', 'b', 'b')
-
-    Even float values should work so long as the comparison operator
-    supports it.
-
-    >>> r[4.5]
-    'b'
-
-    Notice that the way rangemap is defined, it must be open-ended
-    on one side.
-
-    >>> r[0]
-    'a'
-    >>> r[-1]
-    'a'
-
-    One can close the open-end of the RangeMap by using undefined_value
-
-    >>> r = RangeMap({0: RangeMap.undefined_value, 3: 'a', 6: 'b'})
-    >>> r[0]
-    Traceback (most recent call last):
-    ...
-    KeyError: 0
-
-    One can get the first or last elements in the range by using RangeMap.Item
-
-    >>> last_item = RangeMap.Item(-1)
-    >>> r[last_item]
-    'b'
-
-    .last_item is a shortcut for Item(-1)
-
-    >>> r[RangeMap.last_item]
-    'b'
-
-    Sometimes it's useful to find the bounds for a RangeMap
-
-    >>> r.bounds()
-    (0, 6)
-
-    RangeMap supports .get(key, default)
-
-    >>> r.get(0, 'not found')
-    'not found'
-
-    >>> r.get(7, 'not found')
-    'not found'
-
-    One often wishes to define the ranges by their left-most values,
-    which requires use of sort params and a key_match_comparator.
-
-    >>> r = RangeMap({1: 'a', 4: 'b'},
-    ...     sort_params=dict(reverse=True),
-    ...     key_match_comparator=operator.ge)
-    >>> r[1], r[2], r[3], r[4], r[5], r[6]
-    ('a', 'a', 'a', 'b', 'b', 'b')
-
-    That wasn't nearly as easy as before, so an alternate constructor
-    is provided:
-
-    >>> r = RangeMap.left({1: 'a', 4: 'b', 7: RangeMap.undefined_value})
-    >>> r[1], r[2], r[3], r[4], r[5], r[6]
-    ('a', 'a', 'a', 'b', 'b', 'b')
-
-    """
-
-    def __init__(
-        self,
-        source,
-        sort_params: Mapping[str, Any] = {},
-        key_match_comparator=operator.le,
-    ):
-        dict.__init__(self, source)
-        self.sort_params = sort_params
-        self.match = key_match_comparator
-
-    @classmethod
-    def left(cls, source):
-        return cls(
-            source, sort_params=dict(reverse=True), key_match_comparator=operator.ge
-        )
-
-    def __getitem__(self, item):
-        sorted_keys = sorted(self.keys(), **self.sort_params)
-        if isinstance(item, RangeMap.Item):
-            result = self.__getitem__(sorted_keys[item])
-        else:
-            key = self._find_first_match_(sorted_keys, item)
-            result = dict.__getitem__(self, key)
-            if result is RangeMap.undefined_value:
-                raise KeyError(key)
-        return result
-
-    def get(self, key, default=None):
-        """
-        Return the value for key if key is in the dictionary, else default.
-        If default is not given, it defaults to None, so that this method
-        never raises a KeyError.
-        """
-        try:
-            return self[key]
-        except KeyError:
-            return default
-
-    def _find_first_match_(self, keys, item):
-        is_match = functools.partial(self.match, item)
-        matches = list(filter(is_match, keys))
-        if matches:
-            return matches[0]
-        raise KeyError(item)
-
-    def bounds(self):
-        sorted_keys = sorted(self.keys(), **self.sort_params)
-        return (sorted_keys[RangeMap.first_item], sorted_keys[RangeMap.last_item])
-
-    # some special values for the RangeMap
-    undefined_value = type('RangeValueUndefined', (), {})()
-
-    class Item(int):
-        "RangeMap Item"
-
-    first_item = Item(0)
-    last_item = Item(-1)
diff --git a/setuptools/_distutils/bcppcompiler.py b/setuptools/_distutils/bcppcompiler.py
index e47dca5d09..9157b43328 100644
--- a/setuptools/_distutils/bcppcompiler.py
+++ b/setuptools/_distutils/bcppcompiler.py
@@ -236,8 +236,7 @@ def link(  # noqa: C901
                 temp_dir = os.path.dirname(objects[0])  # preserve tree structure
                 def_file = os.path.join(temp_dir, f'{modname}.def')
                 contents = ['EXPORTS']
-                for sym in export_symbols or []:
-                    contents.append(f'  {sym}=_{sym}')
+                contents.extend(f'  {sym}=_{sym}' for sym in export_symbols)
                 self.execute(write_file, (def_file, contents), f"writing {def_file}")
 
             # Borland C++ has problems with '/' in paths
diff --git a/setuptools/_distutils/ccompiler.py b/setuptools/_distutils/ccompiler.py
index 9d5297b944..bc4743bcbf 100644
--- a/setuptools/_distutils/ccompiler.py
+++ b/setuptools/_distutils/ccompiler.py
@@ -22,7 +22,7 @@
 )
 from .file_util import move_file
 from .spawn import spawn
-from .util import execute, split_quoted, is_mingw
+from .util import execute, is_mingw, split_quoted
 
 
 class CCompiler:
@@ -1124,10 +1124,10 @@ def show_compilers():
     # commands that use it.
     from distutils.fancy_getopt import FancyGetopt
 
-    compilers = []
-    for compiler in compiler_class.keys():
-        compilers.append(("compiler=" + compiler, None, compiler_class[compiler][2]))
-    compilers.sort()
+    compilers = sorted(
+        ("compiler=" + compiler, None, compiler_class[compiler][2])
+        for compiler in compiler_class.keys()
+    )
     pretty_printer = FancyGetopt(compilers)
     pretty_printer.print_help("List of available compilers:")
 
@@ -1218,8 +1218,7 @@ def gen_preprocess_options(macros, include_dirs):
                 # shell at all costs when we spawn the command!
                 pp_opts.append("-D{}={}".format(*macro))
 
-    for dir in include_dirs:
-        pp_opts.append(f"-I{dir}")
+    pp_opts.extend(f"-I{dir}" for dir in include_dirs)
     return pp_opts
 
 
@@ -1230,10 +1229,7 @@ def gen_lib_options(compiler, library_dirs, runtime_library_dirs, libraries):
     directories.  Returns a list of command-line options suitable for use
     with some compiler (depending on the two format strings passed in).
     """
-    lib_opts = []
-
-    for dir in library_dirs:
-        lib_opts.append(compiler.library_dir_option(dir))
+    lib_opts = [compiler.library_dir_option(dir) for dir in library_dirs]
 
     for dir in runtime_library_dirs:
         lib_opts.extend(always_iterable(compiler.runtime_library_dir_option(dir)))
diff --git a/setuptools/_distutils/command/bdist.py b/setuptools/_distutils/command/bdist.py
index 1738f4e56b..f334075159 100644
--- a/setuptools/_distutils/command/bdist.py
+++ b/setuptools/_distutils/command/bdist.py
@@ -15,9 +15,10 @@ def show_formats():
     """Print list of available formats (arguments to "--format" option)."""
     from ..fancy_getopt import FancyGetopt
 
-    formats = []
-    for format in bdist.format_commands:
-        formats.append(("formats=" + format, None, bdist.format_commands[format][1]))
+    formats = [
+        ("formats=" + format, None, bdist.format_commands[format][1])
+        for format in bdist.format_commands
+    ]
     pretty_printer = FancyGetopt(formats)
     pretty_printer.print_help("List of available distribution formats:")
 
diff --git a/setuptools/_distutils/command/build_ext.py b/setuptools/_distutils/command/build_ext.py
index 18e1601a28..cf475fe824 100644
--- a/setuptools/_distutils/command/build_ext.py
+++ b/setuptools/_distutils/command/build_ext.py
@@ -465,10 +465,7 @@ def get_outputs(self):
         # And build the list of output (built) filenames.  Note that this
         # ignores the 'inplace' flag, and assumes everything goes in the
         # "build" tree.
-        outputs = []
-        for ext in self.extensions:
-            outputs.append(self.get_ext_fullpath(ext.name))
-        return outputs
+        return [self.get_ext_fullpath(ext.name) for ext in self.extensions]
 
     def build_extensions(self):
         # First, sanity-check the 'extensions' list
diff --git a/setuptools/_distutils/command/check.py b/setuptools/_distutils/command/check.py
index 58b3f949f9..93d754e73d 100644
--- a/setuptools/_distutils/command/check.py
+++ b/setuptools/_distutils/command/check.py
@@ -100,10 +100,9 @@ def check_metadata(self):
         """
         metadata = self.distribution.metadata
 
-        missing = []
-        for attr in 'name', 'version':
-            if not getattr(metadata, attr, None):
-                missing.append(attr)
+        missing = [
+            attr for attr in ('name', 'version') if not getattr(metadata, attr, None)
+        ]
 
         if missing:
             self.warn("missing required meta-data: {}".format(', '.join(missing)))
diff --git a/setuptools/_distutils/command/install_data.py b/setuptools/_distutils/command/install_data.py
index 624c0b901b..a90ec3b4d0 100644
--- a/setuptools/_distutils/command/install_data.py
+++ b/setuptools/_distutils/command/install_data.py
@@ -5,7 +5,11 @@
 
 # contributed by Bastian Kleineidam
 
+from __future__ import annotations
+
+import functools
 import os
+from typing import Iterable
 
 from ..core import Command
 from ..util import change_root, convert_path
@@ -46,36 +50,42 @@ def finalize_options(self):
     def run(self):
         self.mkpath(self.install_dir)
         for f in self.data_files:
-            if isinstance(f, str):
-                # it's a simple file, so copy it
-                f = convert_path(f)
-                if self.warn_dir:
-                    self.warn(
-                        "setup script did not provide a directory for "
-                        f"'{f}' -- installing right in '{self.install_dir}'"
-                    )
-                (out, _) = self.copy_file(f, self.install_dir)
+            self._copy(f)
+
+    @functools.singledispatchmethod
+    def _copy(self, f: tuple[str | os.PathLike, Iterable[str | os.PathLike]]):
+        # it's a tuple with path to install to and a list of files
+        dir = convert_path(f[0])
+        if not os.path.isabs(dir):
+            dir = os.path.join(self.install_dir, dir)
+        elif self.root:
+            dir = change_root(self.root, dir)
+        self.mkpath(dir)
+
+        if f[1] == []:
+            # If there are no files listed, the user must be
+            # trying to create an empty directory, so add the
+            # directory to the list of output files.
+            self.outfiles.append(dir)
+        else:
+            # Copy files, adding them to the list of output files.
+            for data in f[1]:
+                data = convert_path(data)
+                (out, _) = self.copy_file(data, dir)
                 self.outfiles.append(out)
-            else:
-                # it's a tuple with path to install to and a list of files
-                dir = convert_path(f[0])
-                if not os.path.isabs(dir):
-                    dir = os.path.join(self.install_dir, dir)
-                elif self.root:
-                    dir = change_root(self.root, dir)
-                self.mkpath(dir)
-
-                if f[1] == []:
-                    # If there are no files listed, the user must be
-                    # trying to create an empty directory, so add the
-                    # directory to the list of output files.
-                    self.outfiles.append(dir)
-                else:
-                    # Copy files, adding them to the list of output files.
-                    for data in f[1]:
-                        data = convert_path(data)
-                        (out, _) = self.copy_file(data, dir)
-                        self.outfiles.append(out)
+
+    @_copy.register(str)
+    @_copy.register(os.PathLike)
+    def _(self, f: str | os.PathLike):
+        # it's a simple file, so copy it
+        f = convert_path(f)
+        if self.warn_dir:
+            self.warn(
+                "setup script did not provide a directory for "
+                f"'{f}' -- installing right in '{self.install_dir}'"
+            )
+        (out, _) = self.copy_file(f, self.install_dir)
+        self.outfiles.append(out)
 
     def get_inputs(self):
         return self.data_files or []
diff --git a/setuptools/_distutils/command/install_lib.py b/setuptools/_distutils/command/install_lib.py
index 54a12d38a8..01579d46b4 100644
--- a/setuptools/_distutils/command/install_lib.py
+++ b/setuptools/_distutils/command/install_lib.py
@@ -161,9 +161,7 @@ def _mutate_outputs(self, has_any, build_cmd, cmd_option, output_dir):
         build_dir = getattr(build_cmd, cmd_option)
 
         prefix_len = len(build_dir) + len(os.sep)
-        outputs = []
-        for file in build_files:
-            outputs.append(os.path.join(output_dir, file[prefix_len:]))
+        outputs = [os.path.join(output_dir, file[prefix_len:]) for file in build_files]
 
         return outputs
 
diff --git a/setuptools/_distutils/command/sdist.py b/setuptools/_distutils/command/sdist.py
index 04333dd214..e8abb73920 100644
--- a/setuptools/_distutils/command/sdist.py
+++ b/setuptools/_distutils/command/sdist.py
@@ -24,10 +24,10 @@ def show_formats():
     from ..archive_util import ARCHIVE_FORMATS
     from ..fancy_getopt import FancyGetopt
 
-    formats = []
-    for format in ARCHIVE_FORMATS.keys():
-        formats.append(("formats=" + format, None, ARCHIVE_FORMATS[format][2]))
-    formats.sort()
+    formats = sorted(
+        ("formats=" + format, None, ARCHIVE_FORMATS[format][2])
+        for format in ARCHIVE_FORMATS.keys()
+    )
     FancyGetopt(formats).print_help("List of available source distribution formats:")
 
 
diff --git a/setuptools/_distutils/compat/py38.py b/setuptools/_distutils/compat/py38.py
index 2d44211147..03ec73ef0e 100644
--- a/setuptools/_distutils/compat/py38.py
+++ b/setuptools/_distutils/compat/py38.py
@@ -14,6 +14,7 @@ def removeprefix(self, prefix):
             return self[len(prefix) :]
         else:
             return self[:]
+
 else:
 
     def removesuffix(self, suffix):
diff --git a/setuptools/_distutils/cygwinccompiler.py b/setuptools/_distutils/cygwinccompiler.py
index 7b812fd055..ce412e8329 100644
--- a/setuptools/_distutils/cygwinccompiler.py
+++ b/setuptools/_distutils/cygwinccompiler.py
@@ -9,13 +9,11 @@
 import copy
 import os
 import pathlib
-import re
 import shlex
 import sys
 import warnings
 from subprocess import check_output
 
-from ._collections import RangeMap
 from .errors import (
     CCompilerError,
     CompileError,
@@ -26,42 +24,10 @@
 from .unixccompiler import UnixCCompiler
 from .version import LooseVersion, suppress_known_deprecation
 
-_msvcr_lookup = RangeMap.left(
-    {
-        # MSVC 7.0
-        1300: ['msvcr70'],
-        # MSVC 7.1
-        1310: ['msvcr71'],
-        # VS2005 / MSVC 8.0
-        1400: ['msvcr80'],
-        # VS2008 / MSVC 9.0
-        1500: ['msvcr90'],
-        # VS2010 / MSVC 10.0
-        1600: ['msvcr100'],
-        # VS2012 / MSVC 11.0
-        1700: ['msvcr110'],
-        # VS2013 / MSVC 12.0
-        1800: ['msvcr120'],
-        # VS2015 / MSVC 14.0
-        1900: ['vcruntime140'],
-        2000: RangeMap.undefined_value,
-    },
-)
-
 
 def get_msvcr():
-    """Include the appropriate MSVC runtime library if Python was built
-    with MSVC 7.0 or later.
-    """
-    match = re.search(r'MSC v\.(\d{4})', sys.version)
-    try:
-        msc_ver = int(match.group(1))
-    except AttributeError:
-        return []
-    try:
-        return _msvcr_lookup[msc_ver]
-    except KeyError:
-        raise ValueError(f"Unknown MS Compiler version {msc_ver} ")
+    """No longer needed, but kept for backward compatibility."""
+    return []
 
 
 _runtime_library_dirs_msg = (
@@ -99,18 +65,20 @@ def __init__(self, verbose=False, dry_run=False, force=False):
         self.cxx = os.environ.get('CXX', 'g++')
 
         self.linker_dll = self.cc
+        self.linker_dll_cxx = self.cxx
         shared_option = "-shared"
 
         self.set_executables(
             compiler=f'{self.cc} -mcygwin -O -Wall',
             compiler_so=f'{self.cc} -mcygwin -mdll -O -Wall',
             compiler_cxx=f'{self.cxx} -mcygwin -O -Wall',
+            compiler_so_cxx=f'{self.cxx} -mcygwin -mdll -O -Wall',
             linker_exe=f'{self.cc} -mcygwin',
-            linker_so=(f'{self.linker_dll} -mcygwin {shared_option}'),
+            linker_so=f'{self.linker_dll} -mcygwin {shared_option}',
+            linker_exe_cxx=f'{self.cxx} -mcygwin',
+            linker_so_cxx=f'{self.linker_dll_cxx} -mcygwin {shared_option}',
         )
 
-        # Include the appropriate MSVC runtime library if Python was built
-        # with MSVC 7.0 or later.
         self.dll_libraries = get_msvcr()
 
     @property
@@ -138,9 +106,17 @@ def _compile(self, obj, src, ext, cc_args, extra_postargs, pp_opts):
                 raise CompileError(msg)
         else:  # for other files use the C-compiler
             try:
-                self.spawn(
-                    self.compiler_so + cc_args + [src, '-o', obj] + extra_postargs
-                )
+                if self.detect_language(src) == 'c++':
+                    self.spawn(
+                        self.compiler_so_cxx
+                        + cc_args
+                        + [src, '-o', obj]
+                        + extra_postargs
+                    )
+                else:
+                    self.spawn(
+                        self.compiler_so + cc_args + [src, '-o', obj] + extra_postargs
+                    )
             except DistutilsExecError as msg:
                 raise CompileError(msg)
 
@@ -276,9 +252,12 @@ def __init__(self, verbose=False, dry_run=False, force=False):
         self.set_executables(
             compiler=f'{self.cc} -O -Wall',
             compiler_so=f'{self.cc} -shared -O -Wall',
+            compiler_so_cxx=f'{self.cxx} -shared -O -Wall',
             compiler_cxx=f'{self.cxx} -O -Wall',
             linker_exe=f'{self.cc}',
             linker_so=f'{self.linker_dll} {shared_option}',
+            linker_exe_cxx=f'{self.cxx}',
+            linker_so_cxx=f'{self.linker_dll_cxx} {shared_option}',
         )
 
     def runtime_library_dir_option(self, dir):
diff --git a/setuptools/_distutils/dist.py b/setuptools/_distutils/dist.py
index d7d4ca8fc8..0a57d60be9 100644
--- a/setuptools/_distutils/dist.py
+++ b/setuptools/_distutils/dist.py
@@ -745,10 +745,7 @@ def print_commands(self):
         for cmd in std_commands:
             is_std.add(cmd)
 
-        extra_commands = []
-        for cmd in self.cmdclass.keys():
-            if cmd not in is_std:
-                extra_commands.append(cmd)
+        extra_commands = [cmd for cmd in self.cmdclass.keys() if cmd not in is_std]
 
         max_length = 0
         for cmd in std_commands + extra_commands:
@@ -776,10 +773,7 @@ def get_command_list(self):
         for cmd in std_commands:
             is_std.add(cmd)
 
-        extra_commands = []
-        for cmd in self.cmdclass.keys():
-            if cmd not in is_std:
-                extra_commands.append(cmd)
+        extra_commands = [cmd for cmd in self.cmdclass.keys() if cmd not in is_std]
 
         rv = []
         for cmd in std_commands + extra_commands:
@@ -1301,7 +1295,4 @@ def fix_help_options(options):
     """Convert a 4-tuple 'help_options' list as found in various command
     classes to the 3-tuple form required by FancyGetopt.
     """
-    new_options = []
-    for help_tuple in options:
-        new_options.append(help_tuple[0:3])
-    return new_options
+    return [opt[0:3] for opt in options]
diff --git a/setuptools/_distutils/extension.py b/setuptools/_distutils/extension.py
index 04e871bcd6..b302082f7a 100644
--- a/setuptools/_distutils/extension.py
+++ b/setuptools/_distutils/extension.py
@@ -26,7 +26,7 @@ class Extension:
       name : string
         the full name of the extension, including any packages -- ie.
         *not* a filename or pathname, but Python dotted name
-      sources : [string]
+      sources : [string | os.PathLike]
         list of source filenames, relative to the distribution root
         (where the setup script lives), in Unix form (slash-separated)
         for portability.  Source files may be C, C++, SWIG (.i),
@@ -106,11 +106,16 @@ def __init__(
     ):
         if not isinstance(name, str):
             raise AssertionError("'name' must be a string")
-        if not (isinstance(sources, list) and all(isinstance(v, str) for v in sources)):
-            raise AssertionError("'sources' must be a list of strings")
+        if not (
+            isinstance(sources, list)
+            and all(isinstance(v, (str, os.PathLike)) for v in sources)
+        ):
+            raise AssertionError(
+                "'sources' must be a list of strings or PathLike objects."
+            )
 
         self.name = name
-        self.sources = sources
+        self.sources = list(map(os.fspath, sources))
         self.include_dirs = include_dirs or []
         self.define_macros = define_macros or []
         self.undef_macros = undef_macros or []
diff --git a/setuptools/_distutils/msvc9compiler.py b/setuptools/_distutils/msvc9compiler.py
index f860a8d383..4c70848730 100644
--- a/setuptools/_distutils/msvc9compiler.py
+++ b/setuptools/_distutils/msvc9compiler.py
@@ -640,9 +640,7 @@ def link(  # noqa: C901
                 else:
                     ldflags = self.ldflags_shared
 
-            export_opts = []
-            for sym in export_symbols or []:
-                export_opts.append("/EXPORT:" + sym)
+            export_opts = [f"/EXPORT:{sym}" for sym in export_symbols or []]
 
             ld_args = (
                 ldflags + lib_opts + export_opts + objects + ['/OUT:' + output_filename]
diff --git a/setuptools/_distutils/msvccompiler.py b/setuptools/_distutils/msvccompiler.py
index 2bf94e60c9..2a5e61d78d 100644
--- a/setuptools/_distutils/msvccompiler.py
+++ b/setuptools/_distutils/msvccompiler.py
@@ -534,9 +534,7 @@ def link(  # noqa: C901
                 else:
                     ldflags = self.ldflags_shared
 
-            export_opts = []
-            for sym in export_symbols or []:
-                export_opts.append("/EXPORT:" + sym)
+            export_opts = [f"/EXPORT:{sym}" for sym in export_symbols or []]
 
             ld_args = (
                 ldflags + lib_opts + export_opts + objects + ['/OUT:' + output_filename]
diff --git a/setuptools/_distutils/spawn.py b/setuptools/_distutils/spawn.py
index 50d30a2761..107b011397 100644
--- a/setuptools/_distutils/spawn.py
+++ b/setuptools/_distutils/spawn.py
@@ -12,7 +12,6 @@
 import subprocess
 import sys
 import warnings
-
 from typing import Mapping
 
 from ._log import log
diff --git a/setuptools/_distutils/sysconfig.py b/setuptools/_distutils/sysconfig.py
index 7ebe67687e..fbdd5d73ae 100644
--- a/setuptools/_distutils/sysconfig.py
+++ b/setuptools/_distutils/sysconfig.py
@@ -287,7 +287,7 @@ def _customize_macos():
     )
 
 
-def customize_compiler(compiler):  # noqa: C901
+def customize_compiler(compiler):
     """Do any platform-specific customization of a CCompiler instance.
 
     Mainly needed on Unix, so we can plug in the information that
@@ -304,6 +304,7 @@ def customize_compiler(compiler):  # noqa: C901
             cflags,
             ccshared,
             ldshared,
+            ldcxxshared,
             shlib_suffix,
             ar,
             ar_flags,
@@ -313,11 +314,14 @@ def customize_compiler(compiler):  # noqa: C901
             'CFLAGS',
             'CCSHARED',
             'LDSHARED',
+            'LDCXXSHARED',
             'SHLIB_SUFFIX',
             'AR',
             'ARFLAGS',
         )
 
+        cxxflags = cflags
+
         if 'CC' in os.environ:
             newcc = os.environ['CC']
             if 'LDSHARED' not in os.environ and ldshared.startswith(cc):
@@ -325,38 +329,42 @@ def customize_compiler(compiler):  # noqa: C901
                 #       command for LDSHARED as well
                 ldshared = newcc + ldshared[len(cc) :]
             cc = newcc
-        if 'CXX' in os.environ:
-            cxx = os.environ['CXX']
-        if 'LDSHARED' in os.environ:
-            ldshared = os.environ['LDSHARED']
-        if 'CPP' in os.environ:
-            cpp = os.environ['CPP']
-        else:
-            cpp = cc + " -E"  # not always
-        if 'LDFLAGS' in os.environ:
-            ldshared = ldshared + ' ' + os.environ['LDFLAGS']
-        if 'CFLAGS' in os.environ:
-            cflags = cflags + ' ' + os.environ['CFLAGS']
-            ldshared = ldshared + ' ' + os.environ['CFLAGS']
-        if 'CPPFLAGS' in os.environ:
-            cpp = cpp + ' ' + os.environ['CPPFLAGS']
-            cflags = cflags + ' ' + os.environ['CPPFLAGS']
-            ldshared = ldshared + ' ' + os.environ['CPPFLAGS']
-        if 'AR' in os.environ:
-            ar = os.environ['AR']
-        if 'ARFLAGS' in os.environ:
-            archiver = ar + ' ' + os.environ['ARFLAGS']
-        else:
-            archiver = ar + ' ' + ar_flags
+        cxx = os.environ.get('CXX', cxx)
+        ldshared = os.environ.get('LDSHARED', ldshared)
+        ldcxxshared = os.environ.get('LDCXXSHARED', ldcxxshared)
+        cpp = os.environ.get(
+            'CPP',
+            cc + " -E",  # not always
+        )
 
+        ldshared = _add_flags(ldshared, 'LD')
+        ldcxxshared = _add_flags(ldcxxshared, 'LD')
+        cflags = _add_flags(cflags, 'C')
+        ldshared = _add_flags(ldshared, 'C')
+        cxxflags = os.environ.get('CXXFLAGS', cxxflags)
+        ldcxxshared = _add_flags(ldcxxshared, 'CXX')
+        cpp = _add_flags(cpp, 'CPP')
+        cflags = _add_flags(cflags, 'CPP')
+        cxxflags = _add_flags(cxxflags, 'CPP')
+        ldshared = _add_flags(ldshared, 'CPP')
+        ldcxxshared = _add_flags(ldcxxshared, 'CPP')
+
+        ar = os.environ.get('AR', ar)
+
+        archiver = ar + ' ' + os.environ.get('ARFLAGS', ar_flags)
         cc_cmd = cc + ' ' + cflags
+        cxx_cmd = cxx + ' ' + cxxflags
+
         compiler.set_executables(
             preprocessor=cpp,
             compiler=cc_cmd,
             compiler_so=cc_cmd + ' ' + ccshared,
-            compiler_cxx=cxx,
+            compiler_cxx=cxx_cmd,
+            compiler_so_cxx=cxx_cmd + ' ' + ccshared,
             linker_so=ldshared,
+            linker_so_cxx=ldcxxshared,
             linker_exe=cc,
+            linker_exe_cxx=cxx,
             archiver=archiver,
         )
 
@@ -561,3 +569,14 @@ def get_config_var(name):
 
         warnings.warn('SO is deprecated, use EXT_SUFFIX', DeprecationWarning, 2)
     return get_config_vars().get(name)
+
+
+@pass_none
+def _add_flags(value: str, type: str) -> str:
+    """
+    Add any flags from the environment for the given type.
+
+    type is the prefix to FLAGS in the environment key (e.g. "C" for "CFLAGS").
+    """
+    flags = os.environ.get(f'{type}FLAGS')
+    return f'{value} {flags}' if flags else value
diff --git a/setuptools/_distutils/tests/test_archive_util.py b/setuptools/_distutils/tests/test_archive_util.py
index abbcd36cb0..389eba16e8 100644
--- a/setuptools/_distutils/tests/test_archive_util.py
+++ b/setuptools/_distutils/tests/test_archive_util.py
@@ -18,10 +18,10 @@
 from distutils.spawn import spawn
 from distutils.tests import support
 from os.path import splitdrive
-from test.support import patch
 
 import path
 import pytest
+from test.support import patch
 
 from .compat.py38 import check_warnings
 from .unix_compat import UID_0_SUPPORT, grp, pwd, require_uid_0, require_unix_id
diff --git a/setuptools/_distutils/tests/test_build.py b/setuptools/_distutils/tests/test_build.py
index 8fb1bc1b77..d379aca0bb 100644
--- a/setuptools/_distutils/tests/test_build.py
+++ b/setuptools/_distutils/tests/test_build.py
@@ -4,8 +4,7 @@
 import sys
 from distutils.command.build import build
 from distutils.tests import support
-from sysconfig import get_config_var
-from sysconfig import get_platform
+from sysconfig import get_config_var, get_platform
 
 
 class TestBuild(support.TempdirManager):
diff --git a/setuptools/_distutils/tests/test_build_ext.py b/setuptools/_distutils/tests/test_build_ext.py
index 6c4c4ba869..8bd3cef855 100644
--- a/setuptools/_distutils/tests/test_build_ext.py
+++ b/setuptools/_distutils/tests/test_build_ext.py
@@ -25,11 +25,11 @@
     fixup_build_ext,
 )
 from io import StringIO
-from test import support
 
 import jaraco.path
 import path
 import pytest
+from test import support
 
 from .compat import py38 as import_helper
 
diff --git a/setuptools/_distutils/tests/test_cygwinccompiler.py b/setuptools/_distutils/tests/test_cygwinccompiler.py
index 2e1640b757..677bc0ac99 100644
--- a/setuptools/_distutils/tests/test_cygwinccompiler.py
+++ b/setuptools/_distutils/tests/test_cygwinccompiler.py
@@ -71,50 +71,8 @@ def test_check_config_h(self):
         assert check_config_h()[0] == CONFIG_H_OK
 
     def test_get_msvcr(self):
-        # []
-        sys.version = (
-            '2.6.1 (r261:67515, Dec  6 2008, 16:42:21) '
-            '\n[GCC 4.0.1 (Apple Computer, Inc. build 5370)]'
-        )
         assert get_msvcr() == []
 
-        # MSVC 7.0
-        sys.version = (
-            '2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.1300 32 bits (Intel)]'
-        )
-        assert get_msvcr() == ['msvcr70']
-
-        # MSVC 7.1
-        sys.version = (
-            '2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.1310 32 bits (Intel)]'
-        )
-        assert get_msvcr() == ['msvcr71']
-
-        # VS2005 / MSVC 8.0
-        sys.version = (
-            '2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.1400 32 bits (Intel)]'
-        )
-        assert get_msvcr() == ['msvcr80']
-
-        # VS2008 / MSVC 9.0
-        sys.version = (
-            '2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.1500 32 bits (Intel)]'
-        )
-        assert get_msvcr() == ['msvcr90']
-
-        sys.version = (
-            '3.10.0 (tags/v3.10.0:b494f59, Oct  4 2021, 18:46:30) '
-            '[MSC v.1929 32 bit (Intel)]'
-        )
-        assert get_msvcr() == ['vcruntime140']
-
-        # unknown
-        sys.version = (
-            '2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.2000 32 bits (Intel)]'
-        )
-        with pytest.raises(ValueError):
-            get_msvcr()
-
     @pytest.mark.skipif('sys.platform != "cygwin"')
     def test_dll_libraries_not_none(self):
         from distutils.cygwinccompiler import CygwinCCompiler
diff --git a/setuptools/_distutils/tests/test_dist.py b/setuptools/_distutils/tests/test_dist.py
index 5bd206fec1..4d78a19803 100644
--- a/setuptools/_distutils/tests/test_dist.py
+++ b/setuptools/_distutils/tests/test_dist.py
@@ -88,7 +88,7 @@ def test_command_packages_cmdline(self, clear_argv):
         'distutils' not in Distribution.parse_config_files.__module__,
         reason='Cannot test when virtualenv has monkey-patched Distribution',
     )
-    def test_venv_install_options(self, tmp_path):
+    def test_venv_install_options(self, tmp_path, clear_argv):
         sys.argv.append("install")
         file = str(tmp_path / 'file')
 
diff --git a/setuptools/_distutils/tests/test_extension.py b/setuptools/_distutils/tests/test_extension.py
index 527a135506..41872e04e8 100644
--- a/setuptools/_distutils/tests/test_extension.py
+++ b/setuptools/_distutils/tests/test_extension.py
@@ -1,6 +1,7 @@
 """Tests for distutils.extension."""
 
 import os
+import pathlib
 import warnings
 from distutils.extension import Extension, read_setup_file
 
@@ -68,13 +69,15 @@ def test_extension_init(self):
         assert ext.name == 'name'
 
         # the second argument, which is the list of files, must
-        # be a list of strings
+        # be a list of strings or PathLike objects
         with pytest.raises(AssertionError):
             Extension('name', 'file')
         with pytest.raises(AssertionError):
             Extension('name', ['file', 1])
         ext = Extension('name', ['file1', 'file2'])
         assert ext.sources == ['file1', 'file2']
+        ext = Extension('name', [pathlib.Path('file1'), pathlib.Path('file2')])
+        assert ext.sources == ['file1', 'file2']
 
         # others arguments have defaults
         for attr in (
diff --git a/setuptools/_distutils/tests/test_install_data.py b/setuptools/_distutils/tests/test_install_data.py
index f34070b10b..c800f86c64 100644
--- a/setuptools/_distutils/tests/test_install_data.py
+++ b/setuptools/_distutils/tests/test_install_data.py
@@ -1,6 +1,7 @@
 """Tests for distutils.command.install_data."""
 
 import os
+import pathlib
 from distutils.command.install_data import install_data
 from distutils.tests import support
 
@@ -18,22 +19,27 @@ def test_simple_run(self):
 
         # data_files can contain
         #  - simple files
+        #  - a Path object
         #  - a tuple with a path, and a list of file
         one = os.path.join(pkg_dir, 'one')
         self.write_file(one, 'xxx')
         inst2 = os.path.join(pkg_dir, 'inst2')
         two = os.path.join(pkg_dir, 'two')
         self.write_file(two, 'xxx')
+        three = pathlib.Path(pkg_dir) / 'three'
+        self.write_file(three, 'xxx')
 
-        cmd.data_files = [one, (inst2, [two])]
-        assert cmd.get_inputs() == [one, (inst2, [two])]
+        cmd.data_files = [one, (inst2, [two]), three]
+        assert cmd.get_inputs() == [one, (inst2, [two]), three]
 
         # let's run the command
         cmd.ensure_finalized()
         cmd.run()
 
         # let's check the result
-        assert len(cmd.get_outputs()) == 2
+        assert len(cmd.get_outputs()) == 3
+        rthree = os.path.split(one)[-1]
+        assert os.path.exists(os.path.join(inst, rthree))
         rtwo = os.path.split(two)[-1]
         assert os.path.exists(os.path.join(inst2, rtwo))
         rone = os.path.split(one)[-1]
@@ -46,21 +52,23 @@ def test_simple_run(self):
         cmd.run()
 
         # let's check the result
-        assert len(cmd.get_outputs()) == 2
+        assert len(cmd.get_outputs()) == 3
+        assert os.path.exists(os.path.join(inst, rthree))
         assert os.path.exists(os.path.join(inst2, rtwo))
         assert os.path.exists(os.path.join(inst, rone))
         cmd.outfiles = []
 
         # now using root and empty dir
         cmd.root = os.path.join(pkg_dir, 'root')
-        inst4 = os.path.join(pkg_dir, 'inst4')
-        three = os.path.join(cmd.install_dir, 'three')
-        self.write_file(three, 'xx')
-        cmd.data_files = [one, (inst2, [two]), ('inst3', [three]), (inst4, [])]
+        inst5 = os.path.join(pkg_dir, 'inst5')
+        four = os.path.join(cmd.install_dir, 'four')
+        self.write_file(four, 'xx')
+        cmd.data_files = [one, (inst2, [two]), three, ('inst5', [four]), (inst5, [])]
         cmd.ensure_finalized()
         cmd.run()
 
         # let's check the result
-        assert len(cmd.get_outputs()) == 4
+        assert len(cmd.get_outputs()) == 5
+        assert os.path.exists(os.path.join(inst, rthree))
         assert os.path.exists(os.path.join(inst2, rtwo))
         assert os.path.exists(os.path.join(inst, rone))
diff --git a/setuptools/_distutils/tests/test_mingwccompiler.py b/setuptools/_distutils/tests/test_mingwccompiler.py
index fd201cd773..3e3ad5058c 100644
--- a/setuptools/_distutils/tests/test_mingwccompiler.py
+++ b/setuptools/_distutils/tests/test_mingwccompiler.py
@@ -1,8 +1,8 @@
-import pytest
-
-from distutils.util import split_quoted, is_mingw
-from distutils.errors import DistutilsPlatformError, CCompilerError
 from distutils import sysconfig
+from distutils.errors import CCompilerError, DistutilsPlatformError
+from distutils.util import is_mingw, split_quoted
+
+import pytest
 
 
 class TestMingw32CCompiler:
@@ -45,6 +45,7 @@ def test_cygwincc_error(self, monkeypatch):
         with pytest.raises(CCompilerError):
             distutils.cygwinccompiler.Mingw32CCompiler()
 
+    @pytest.mark.skipif('sys.platform == "cygwin"')
     def test_customize_compiler_with_msvc_python(self):
         from distutils.cygwinccompiler import Mingw32CCompiler
 
diff --git a/setuptools/_distutils/tests/test_spawn.py b/setuptools/_distutils/tests/test_spawn.py
index 2576bdd53d..fd7b669cbf 100644
--- a/setuptools/_distutils/tests/test_spawn.py
+++ b/setuptools/_distutils/tests/test_spawn.py
@@ -7,10 +7,10 @@
 from distutils.errors import DistutilsExecError
 from distutils.spawn import find_executable, spawn
 from distutils.tests import support
-from test.support import unix_shell
 
 import path
 import pytest
+from test.support import unix_shell
 
 from .compat import py38 as os_helper
 
diff --git a/setuptools/_distutils/tests/test_sysconfig.py b/setuptools/_distutils/tests/test_sysconfig.py
index 889a398c22..49274a36ae 100644
--- a/setuptools/_distutils/tests/test_sysconfig.py
+++ b/setuptools/_distutils/tests/test_sysconfig.py
@@ -9,12 +9,12 @@
 from distutils import sysconfig
 from distutils.ccompiler import new_compiler  # noqa: F401
 from distutils.unixccompiler import UnixCCompiler
-from test.support import swap_item
 
 import jaraco.envs
 import path
 import pytest
 from jaraco.text import trim
+from test.support import swap_item
 
 
 def _gen_makefile(root, contents):
@@ -134,7 +134,10 @@ def test_customize_compiler(self):
         assert comp.exes['compiler_so'] == (
             'env_cc --sc-cflags --env-cflags --env-cppflags --sc-ccshared'
         )
-        assert comp.exes['compiler_cxx'] == 'env_cxx --env-cxx-flags'
+        assert (
+            comp.exes['compiler_cxx']
+            == 'env_cxx --env-cxx-flags --sc-cflags --env-cppflags'
+        )
         assert comp.exes['linker_exe'] == 'env_cc'
         assert comp.exes['linker_so'] == (
             'env_ldshared --env-ldflags --env-cflags --env-cppflags'
@@ -162,7 +165,7 @@ def test_customize_compiler(self):
         assert comp.exes['preprocessor'] == 'sc_cc -E'
         assert comp.exes['compiler'] == 'sc_cc --sc-cflags'
         assert comp.exes['compiler_so'] == 'sc_cc --sc-cflags --sc-ccshared'
-        assert comp.exes['compiler_cxx'] == 'sc_cxx'
+        assert comp.exes['compiler_cxx'] == 'sc_cxx --sc-cflags'
         assert comp.exes['linker_exe'] == 'sc_cc'
         assert comp.exes['linker_so'] == 'sc_ldshared'
         assert comp.shared_lib_extension == 'sc_shutil_suffix'
diff --git a/setuptools/_distutils/tests/test_unixccompiler.py b/setuptools/_distutils/tests/test_unixccompiler.py
index d2c88e9116..50b66544a8 100644
--- a/setuptools/_distutils/tests/test_unixccompiler.py
+++ b/setuptools/_distutils/tests/test_unixccompiler.py
@@ -257,9 +257,13 @@ def test_cc_overrides_ldshared_for_cxx_correctly(self):
         def gcv(v):
             if v == 'LDSHARED':
                 return 'gcc-4.2 -bundle -undefined dynamic_lookup '
+            elif v == 'LDCXXSHARED':
+                return 'g++-4.2 -bundle -undefined dynamic_lookup '
             elif v == 'CXX':
                 return 'g++-4.2'
-            return 'gcc-4.2'
+            elif v == 'CC':
+                return 'gcc-4.2'
+            return ''
 
         def gcvs(*args, _orig=sysconfig.get_config_vars):
             if args:
@@ -315,3 +319,33 @@ def test_has_function(self):
         self.cc.output_dir = 'scratch'
         os.chdir(self.mkdtemp())
         self.cc.has_function('abort')
+
+    def test_find_library_file(self, monkeypatch):
+        compiler = UnixCCompiler()
+        compiler._library_root = lambda dir: dir
+        monkeypatch.setattr(os.path, 'exists', lambda d: 'existing' in d)
+
+        libname = 'libabc.dylib' if sys.platform != 'cygwin' else 'cygabc.dll'
+        dirs = ('/foo/bar/missing', '/foo/bar/existing')
+        assert (
+            compiler.find_library_file(dirs, 'abc').replace('\\', '/')
+            == f'/foo/bar/existing/{libname}'
+        )
+        assert (
+            compiler.find_library_file(reversed(dirs), 'abc').replace('\\', '/')
+            == f'/foo/bar/existing/{libname}'
+        )
+
+        monkeypatch.setattr(
+            os.path,
+            'exists',
+            lambda d: 'existing' in d and '.a' in d and '.dll.a' not in d,
+        )
+        assert (
+            compiler.find_library_file(dirs, 'abc').replace('\\', '/')
+            == '/foo/bar/existing/libabc.a'
+        )
+        assert (
+            compiler.find_library_file(reversed(dirs), 'abc').replace('\\', '/')
+            == '/foo/bar/existing/libabc.a'
+        )
diff --git a/setuptools/_distutils/tests/test_util.py b/setuptools/_distutils/tests/test_util.py
index 0de4e1a59c..00c9743ed0 100644
--- a/setuptools/_distutils/tests/test_util.py
+++ b/setuptools/_distutils/tests/test_util.py
@@ -5,6 +5,7 @@
 import email.policy
 import io
 import os
+import pathlib
 import sys
 import sysconfig as stdlib_sysconfig
 import unittest.mock as mock
@@ -63,30 +64,9 @@ def test_get_platform(self):
                 assert get_platform() == 'win-arm64'
 
     def test_convert_path(self):
-        # linux/mac
-        os.sep = '/'
-
-        def _join(path):
-            return '/'.join(path)
-
-        os.path.join = _join
-
-        assert convert_path('/home/to/my/stuff') == '/home/to/my/stuff'
-
-        # win
-        os.sep = '\\'
-
-        def _join(*path):
-            return '\\'.join(path)
-
-        os.path.join = _join
-
-        with pytest.raises(ValueError):
-            convert_path('/home/to/my/stuff')
-        with pytest.raises(ValueError):
-            convert_path('home/to/my/stuff/')
-
-        assert convert_path('home/to/my/stuff') == 'home\\to\\my\\stuff'
+        expected = os.sep.join(('', 'home', 'to', 'my', 'stuff'))
+        assert convert_path('/home/to/my/stuff') == expected
+        assert convert_path(pathlib.Path('/home/to/my/stuff')) == expected
         assert convert_path('.') == os.curdir
 
     def test_change_root(self):
diff --git a/setuptools/_distutils/unixccompiler.py b/setuptools/_distutils/unixccompiler.py
index 7e68596b26..6c1116ae8f 100644
--- a/setuptools/_distutils/unixccompiler.py
+++ b/setuptools/_distutils/unixccompiler.py
@@ -118,9 +118,12 @@ class UnixCCompiler(CCompiler):
         'preprocessor': None,
         'compiler': ["cc"],
         'compiler_so': ["cc"],
-        'compiler_cxx': ["cc"],
+        'compiler_cxx': ["c++"],
+        'compiler_so_cxx': ["c++"],
         'linker_so': ["cc", "-shared"],
+        'linker_so_cxx': ["c++", "-shared"],
         'linker_exe': ["cc"],
+        'linker_exe_cxx': ["c++", "-shared"],
         'archiver': ["ar", "-cr"],
         'ranlib': None,
     }
@@ -187,8 +190,14 @@ def preprocess(
 
     def _compile(self, obj, src, ext, cc_args, extra_postargs, pp_opts):
         compiler_so = compiler_fixup(self.compiler_so, cc_args + extra_postargs)
+        compiler_so_cxx = compiler_fixup(self.compiler_so_cxx, cc_args + extra_postargs)
         try:
-            self.spawn(compiler_so + cc_args + [src, '-o', obj] + extra_postargs)
+            if self.detect_language(src) == 'c++':
+                self.spawn(
+                    compiler_so_cxx + cc_args + [src, '-o', obj] + extra_postargs
+                )
+            else:
+                self.spawn(compiler_so + cc_args + [src, '-o', obj] + extra_postargs)
         except DistutilsExecError as msg:
             raise CompileError(msg)
 
@@ -256,7 +265,13 @@ def link(
                 # building an executable or linker_so (with shared options)
                 # when building a shared library.
                 building_exe = target_desc == CCompiler.EXECUTABLE
-                linker = (self.linker_exe if building_exe else self.linker_so)[:]
+                linker = (
+                    self.linker_exe
+                    if building_exe
+                    else (
+                        self.linker_so_cxx if target_lang == "c++" else self.linker_so
+                    )
+                )[:]
 
                 if target_lang == "c++" and self.compiler_cxx:
                     env, linker_ne = _split_env(linker)
@@ -366,27 +381,11 @@ def _library_root(dir):
         return os.path.join(match.group(1), dir[1:]) if apply_root else dir
 
     def find_library_file(self, dirs, lib, debug=False):
-        r"""
+        """
         Second-guess the linker with not much hard
         data to go on: GCC seems to prefer the shared library, so
         assume that *all* Unix C compilers do,
         ignoring even GCC's "-static" option.
-
-        >>> compiler = UnixCCompiler()
-        >>> compiler._library_root = lambda dir: dir
-        >>> monkeypatch = getfixture('monkeypatch')
-        >>> monkeypatch.setattr(os.path, 'exists', lambda d: 'existing' in d)
-        >>> dirs = ('/foo/bar/missing', '/foo/bar/existing')
-        >>> compiler.find_library_file(dirs, 'abc').replace('\\', '/')
-        '/foo/bar/existing/libabc.dylib'
-        >>> compiler.find_library_file(reversed(dirs), 'abc').replace('\\', '/')
-        '/foo/bar/existing/libabc.dylib'
-        >>> monkeypatch.setattr(os.path, 'exists',
-        ...     lambda d: 'existing' in d and '.a' in d)
-        >>> compiler.find_library_file(dirs, 'abc').replace('\\', '/')
-        '/foo/bar/existing/libabc.a'
-        >>> compiler.find_library_file(reversed(dirs), 'abc').replace('\\', '/')
-        '/foo/bar/existing/libabc.a'
         """
         lib_names = (
             self.library_filename(lib, lib_type=type)
diff --git a/setuptools/_distutils/util.py b/setuptools/_distutils/util.py
index 9db89b0979..4cc6bd283c 100644
--- a/setuptools/_distutils/util.py
+++ b/setuptools/_distutils/util.py
@@ -4,9 +4,12 @@
 one of the other *util.py modules.
 """
 
+from __future__ import annotations
+
 import functools
 import importlib.util
 import os
+import pathlib
 import re
 import string
 import subprocess
@@ -14,6 +17,7 @@
 import sysconfig
 import tempfile
 
+from ._functools import pass_none
 from ._log import log
 from ._modified import newer
 from .errors import DistutilsByteCompileError, DistutilsPlatformError
@@ -116,33 +120,23 @@ def split_version(s):
     return [int(n) for n in s.split('.')]
 
 
-def convert_path(pathname):
-    """Return 'pathname' as a name that will work on the native filesystem,
-    i.e. split it on '/' and put it back together again using the current
-    directory separator.  Needed because filenames in the setup script are
-    always supplied in Unix style, and have to be converted to the local
-    convention before we can actually use them in the filesystem.  Raises
-    ValueError on non-Unix-ish systems if 'pathname' either starts or
-    ends with a slash.
+@pass_none
+def convert_path(pathname: str | os.PathLike) -> str:
+    r"""
+    Allow for pathlib.Path inputs, coax to a native path string.
+
+    If None is passed, will just pass it through as
+    Setuptools relies on this behavior.
+
+    >>> convert_path(None) is None
+    True
+
+    Removes empty paths.
+
+    >>> convert_path('foo/./bar').replace('\\', '/')
+    'foo/bar'
     """
-    if os.sep == '/':
-        return pathname
-    if not pathname:
-        return pathname
-    if pathname[0] == '/':
-        raise ValueError(f"path '{pathname}' cannot be absolute")
-    if pathname[-1] == '/':
-        raise ValueError(f"path '{pathname}' cannot end with '/'")
-
-    paths = pathname.split('/')
-    while '.' in paths:
-        paths.remove('.')
-    if not paths:
-        return os.curdir
-    return os.path.join(*paths)
-
-
-# convert_path ()
+    return os.fspath(pathlib.PurePath(pathname))
 
 
 def change_root(new_root, pathname):