Reduce usage of pkg_resources (#3792)

7 files changed, 70 insertions, 96 deletions

diff --git a/setuptools/command/bdist_egg.py b/setuptools/command/bdist_egg.py
index 11a1c6be..33f483cf 100644
--- a/setuptools/command/bdist_egg.py
+++ b/setuptools/command/bdist_egg.py
@@ -11,7 +11,6 @@ import re
 import textwrap
 import marshal
 
-from pkg_resources import get_build_platform, Distribution
 from setuptools.extension import Library
 from setuptools import Command
 from .._path import ensure_directory
@@ -64,7 +63,7 @@ class bdist_egg(Command):
         ('bdist-dir=', 'b',
          "temporary directory for creating the distribution"),
         ('plat-name=', 'p', "platform name to embed in generated filenames "
-                            "(default: %s)" % get_build_platform()),
+                            "(by default uses `pkg_resources.get_build_platform()`)"),
         ('exclude-source-files', None,
          "remove all .py files from the generated egg"),
         ('keep-temp', 'k',
@@ -98,18 +97,18 @@ class bdist_egg(Command):
             self.bdist_dir = os.path.join(bdist_base, 'egg')
 
         if self.plat_name is None:
+            from pkg_resources import get_build_platform
+
             self.plat_name = get_build_platform()
 
         self.set_undefined_options('bdist', ('dist_dir', 'dist_dir'))
 
         if self.egg_output is None:
-
             # Compute filename of the output egg
-            basename = Distribution(
-                None, None, ei_cmd.egg_name, ei_cmd.egg_version,
-                get_python_version(),
-                self.distribution.has_ext_modules() and self.plat_name
-            ).egg_name()
+            basename = ei_cmd._get_egg_basename(
+                py_version=get_python_version(),
+                platform=self.distribution.has_ext_modules() and self.plat_name,
+            )
 
             self.egg_output = os.path.join(self.dist_dir, basename + '.egg')
 
diff --git a/setuptools/command/develop.py b/setuptools/command/develop.py
index 24fb0a7c..5630ca4c 100644
--- a/setuptools/command/develop.py
+++ b/setuptools/command/develop.py
@@ -5,8 +5,8 @@ import os
 import glob
 import io
 
-import pkg_resources
 from setuptools.command.easy_install import easy_install
+from setuptools import _path
 from setuptools import namespaces
 import setuptools
 
@@ -42,6 +42,8 @@ class develop(namespaces.DevelopInstaller, easy_install):
         self.always_copy_from = '.'  # always copy eggs installed in curdir
 
     def finalize_options(self):
+        import pkg_resources
+
         ei = self.get_finalized_command("egg_info")
         if ei.broken_egg_info:
             template = "Please rename %r to %r before using 'develop'"
@@ -61,10 +63,8 @@ class develop(namespaces.DevelopInstaller, easy_install):
         if self.egg_path is None:
             self.egg_path = os.path.abspath(ei.egg_base)
 
-        target = pkg_resources.normalize_path(self.egg_base)
-        egg_path = pkg_resources.normalize_path(
-            os.path.join(self.install_dir, self.egg_path)
-        )
+        target = _path.normpath(self.egg_base)
+        egg_path = _path.normpath(os.path.join(self.install_dir, self.egg_path))
         if egg_path != target:
             raise DistutilsOptionError(
                 "--egg-path must be a relative path from the install"
@@ -94,15 +94,16 @@ class develop(namespaces.DevelopInstaller, easy_install):
         path_to_setup = egg_base.replace(os.sep, '/').rstrip('/')
         if path_to_setup != os.curdir:
             path_to_setup = '../' * (path_to_setup.count('/') + 1)
-        resolved = pkg_resources.normalize_path(
+        resolved = _path.normpath(
             os.path.join(install_dir, egg_path, path_to_setup)
         )
-        if resolved != pkg_resources.normalize_path(os.curdir):
+        curdir = _path.normpath(os.curdir)
+        if resolved != curdir:
             raise DistutilsOptionError(
                 "Can't get a consistent path to setup script from"
                 " installation directory",
                 resolved,
-                pkg_resources.normalize_path(os.curdir),
+                curdir,
             )
         return path_to_setup
 
diff --git a/setuptools/command/dist_info.py b/setuptools/command/dist_info.py
index 4966d852..545e9995 100644
--- a/setuptools/command/dist_info.py
+++ b/setuptools/command/dist_info.py
@@ -4,18 +4,16 @@ As defined in the wheel specification
 """
 
 import os
-import re
 import shutil
 import sys
 import warnings
 from contextlib import contextmanager
-from inspect import cleandoc
+from distutils import log
+from distutils.core import Command
 from pathlib import Path
 
-from distutils.core import Command
-from distutils import log
-from setuptools.extern import packaging
-from setuptools._deprecation_warning import SetuptoolsDeprecationWarning
+from .. import _normalization
+from .._deprecation_warning import SetuptoolsDeprecationWarning
 
 
 class dist_info(Command):
@@ -76,8 +74,8 @@ class dist_info(Command):
         egg_info.finalize_options()
         self.egg_info = egg_info
 
-        name = _safe(dist.get_name())
-        version = _version(dist.get_version())
+        name = _normalization.safer_name(dist.get_name())
+        version = _normalization.safer_best_effort_version(dist.get_version())
         self.name = f"{name}-{version}"
         self.dist_info_dir = os.path.join(self.output_dir, f"{self.name}.dist-info")
 
@@ -109,32 +107,6 @@ class dist_info(Command):
             bdist_wheel.egg2dist(egg_info_dir, self.dist_info_dir)
 
 
-def _safe(component: str) -> str:
-    """Escape a component used to form a wheel name according to PEP 491"""
-    return re.sub(r"[^\w\d.]+", "_", component)
-
-
-def _version(version: str) -> str:
-    """Convert an arbitrary string to a version string."""
-    v = version.replace(' ', '.')
-    try:
-        return str(packaging.version.Version(v)).replace("-", "_")
-    except packaging.version.InvalidVersion:
-        msg = f"""Invalid version: {version!r}.
-        !!\n\n
-        ###################
-        # Invalid version #
-        ###################
-        {version!r} is not valid according to PEP 440.\n
-        Please make sure specify a valid version for your package.
-        Also note that future releases of setuptools may halt the build process
-        if an invalid version is given.
-        \n\n!!
-        """
-        warnings.warn(cleandoc(msg))
-        return _safe(v).strip("_")
-
-
 def _rm(dir_name, **opts):
     if os.path.isdir(dir_name):
         shutil.rmtree(dir_name, **opts)
diff --git a/setuptools/command/editable_wheel.py b/setuptools/command/editable_wheel.py
index 083ef185..5e532a7f 100644
--- a/setuptools/command/editable_wheel.py
+++ b/setuptools/command/editable_wheel.py
@@ -12,7 +12,6 @@ Create a wheel that, when installed, will make the source package 'editable'
 
 import logging
 import os
-import re
 import shutil
 import sys
 import traceback
@@ -36,10 +35,17 @@ from typing import (
     Union,
 )
 
-from setuptools import Command, SetuptoolsDeprecationWarning, errors, namespaces
-from setuptools.command.build_py import build_py as build_py_cls
-from setuptools.discovery import find_package_path
-from setuptools.dist import Distribution
+from .. import (
+    Command,
+    SetuptoolsDeprecationWarning,
+    _normalization,
+    _path,
+    errors,
+    namespaces,
+)
+from ..discovery import find_package_path
+from ..dist import Distribution
+from .build_py import build_py as build_py_cls
 
 if TYPE_CHECKING:
     from wheel.wheelfile import WheelFile  # noqa
@@ -482,7 +488,7 @@ class _TopLevelFinder:
         ))
 
         name = f"__editable__.{self.name}.finder"
-        finder = _make_identifier(name)
+        finder = _normalization.safe_identifier(name)
         content = bytes(_finder_template(name, roots, namespaces_), "utf-8")
         wheel.writestr(f"{finder}.py", content)
 
@@ -561,7 +567,7 @@ def _simple_layout(
         return set(package_dir) in ({}, {""})
     parent = os.path.commonpath([_parent_path(k, v) for k, v in layout.items()])
     return all(
-        _normalize_path(Path(parent, *key.split('.'))) == _normalize_path(value)
+        _path.same_path(Path(parent, *key.split('.')), value)
         for key, value in layout.items()
     )
 
@@ -690,21 +696,14 @@ def _is_nested(pkg: str, pkg_path: str, parent: str, parent_path: str) -> bool:
     >>> _is_nested("b.a", "path/b/a", "a", "path/a")
     False
     """
-    norm_pkg_path = _normalize_path(pkg_path)
+    norm_pkg_path = _path.normpath(pkg_path)
     rest = pkg.replace(parent, "", 1).strip(".").split(".")
     return (
         pkg.startswith(parent)
-        and norm_pkg_path == _normalize_path(Path(parent_path, *rest))
+        and norm_pkg_path == _path.normpath(Path(parent_path, *rest))
     )
 
 
-def _normalize_path(filename: _Path) -> str:
-    """Normalize a file/dir name for comparison purposes"""
-    # See pkg_resources.normalize_path
-    file = os.path.abspath(filename) if sys.platform == 'cygwin' else filename
-    return os.path.normcase(os.path.realpath(os.path.normpath(file)))
-
-
 def _empty_dir(dir_: _P) -> _P:
     """Create a directory ensured to be empty. Existing files may be removed."""
     shutil.rmtree(dir_, ignore_errors=True)
@@ -712,18 +711,6 @@ def _empty_dir(dir_: _P) -> _P:
     return dir_
 
 
-def _make_identifier(name: str) -> str:
-    """Make a string safe to be used as Python identifier.
-    >>> _make_identifier("12abc")
-    '_12abc'
-    >>> _make_identifier("__editable__.myns.pkg-78.9.3_local")
-    '__editable___myns_pkg_78_9_3_local'
-    """
-    safe = re.sub(r'\W|^(?=\d)', '_', name)
-    assert safe.isidentifier()
-    return safe
-
-
 class _NamespaceInstaller(namespaces.Installer):
     def __init__(self, distribution, installation_dir, editable_name, src_root):
         self.distribution = distribution
diff --git a/setuptools/command/egg_info.py b/setuptools/command/egg_info.py
index 86e99dd2..afcde5a2 100644
--- a/setuptools/command/egg_info.py
+++ b/setuptools/command/egg_info.py
@@ -18,16 +18,13 @@ import time
 import collections
 
 from .._importlib import metadata
-from .. import _entry_points
+from .. import _entry_points, _normalization
 
 from setuptools import Command
 from setuptools.command.sdist import sdist
 from setuptools.command.sdist import walk_revctrl
 from setuptools.command.setopt import edit_config
 from setuptools.command import bdist_egg
-from pkg_resources import (
-    Requirement, safe_name, parse_version,
-    safe_version, to_filename)
 import setuptools.unicode_utils as unicode_utils
 from setuptools.glob import glob
 
@@ -36,6 +33,9 @@ from setuptools.extern.jaraco.text import yield_lines
 from setuptools import SetuptoolsDeprecationWarning
 
 
+PY_MAJOR = '{}.{}'.format(*sys.version_info)
+
+
 def translate_pattern(glob):  # noqa: C901  # is too complex (14)  # FIXME
     """
     Translate a file path glob like '*.txt' in to a regular expression.
@@ -125,10 +125,11 @@ class InfoCommon:
 
     @property
     def name(self):
-        return safe_name(self.distribution.get_name())
+        return _normalization.safe_name(self.distribution.get_name())
 
     def tagged_version(self):
-        return safe_version(self._maybe_tag(self.distribution.get_version()))
+        tagged = self._maybe_tag(self.distribution.get_version())
+        return _normalization.best_effort_version(tagged)
 
     def _maybe_tag(self, version):
         """
@@ -148,7 +149,7 @@ class InfoCommon:
     def _safe_tags(self) -> str:
         # To implement this we can rely on `safe_version` pretending to be version 0
         # followed by tags. Then we simply discard the starting 0 (fake version number)
-        return safe_version(f"0{self.vtags}")[1:]
+        return _normalization.best_effort_version(f"0{self.vtags}")[1:]
 
     def tags(self) -> str:
         version = ''
@@ -216,12 +217,12 @@ class egg_info(InfoCommon, Command):
         # repercussions.
         self.egg_name = self.name
         self.egg_version = self.tagged_version()
-        parsed_version = parse_version(self.egg_version)
+        parsed_version = packaging.version.Version(self.egg_version)
 
         try:
             is_version = isinstance(parsed_version, packaging.version.Version)
             spec = "%s==%s" if is_version else "%s===%s"
-            Requirement(spec % (self.egg_name, self.egg_version))
+            packaging.requirements.Requirement(spec % (self.egg_name, self.egg_version))
         except ValueError as e:
             raise distutils.errors.DistutilsOptionError(
                 "Invalid distribution name or version syntax: %s-%s" %
@@ -233,7 +234,7 @@ class egg_info(InfoCommon, Command):
             self.egg_base = (dirs or {}).get('', os.curdir)
 
         self.ensure_dirname('egg_base')
-        self.egg_info = to_filename(self.egg_name) + '.egg-info'
+        self.egg_info = _normalization.filename_component(self.egg_name) + '.egg-info'
         if self.egg_base != os.curdir:
             self.egg_info = os.path.join(self.egg_base, self.egg_info)
         if '-' in self.egg_name:
@@ -251,9 +252,13 @@ class egg_info(InfoCommon, Command):
         pd = self.distribution._patched_dist
         if pd is not None and pd.key == self.egg_name.lower():
             pd._version = self.egg_version
-            pd._parsed_version = parse_version(self.egg_version)
+            pd._parsed_version = packaging.version.Version(self.egg_version)
             self.distribution._patched_dist = None
 
+    def _get_egg_basename(self, py_version=PY_MAJOR, platform=None):
+        """Compute filename of the output egg. Private API."""
+        return _egg_basename(self.egg_name, self.egg_version, py_version, platform)
+
     def write_or_delete_file(self, what, filename, data, force=False):
         """Write `data` to `filename` or delete if empty
 
@@ -771,5 +776,15 @@ def get_pkg_info_revision():
     return 0
 
 
+def _egg_basename(egg_name, egg_version, py_version=None, platform=None):
+    """Compute filename of the output egg. Private API."""
+    name = _normalization.filename_component(egg_name)
+    version = _normalization.filename_component(egg_version)
+    egg = f"{name}-{version}-py{py_version or PY_MAJOR}"
+    if platform:
+        egg += f"-{platform}"
+    return egg
+
+
 class EggInfoDeprecationWarning(SetuptoolsDeprecationWarning):
     """Deprecated behavior warning for EggInfo, bypassing suppression."""
diff --git a/setuptools/command/install_egg_info.py b/setuptools/command/install_egg_info.py
index 65ede406..1c549c98 100644
--- a/setuptools/command/install_egg_info.py
+++ b/setuptools/command/install_egg_info.py
@@ -5,7 +5,6 @@ from setuptools import Command
 from setuptools import namespaces
 from setuptools.archive_util import unpack_archive
 from .._path import ensure_directory
-import pkg_resources
 
 
 class install_egg_info(namespaces.Installer, Command):
@@ -24,9 +23,7 @@ class install_egg_info(namespaces.Installer, Command):
         self.set_undefined_options('install_lib',
                                    ('install_dir', 'install_dir'))
         ei_cmd = self.get_finalized_command("egg_info")
-        basename = pkg_resources.Distribution(
-            None, None, ei_cmd.egg_name, ei_cmd.egg_version
-        ).egg_name() + '.egg-info'
+        basename = f"{ei_cmd._get_egg_basename()}.egg-info"
         self.source = ei_cmd.egg_info
         self.target = os.path.join(self.install_dir, basename)
         self.outputs = []
diff --git a/setuptools/command/install_scripts.py b/setuptools/command/install_scripts.py
index aeb0e424..8b3133f1 100644
--- a/setuptools/command/install_scripts.py
+++ b/setuptools/command/install_scripts.py
@@ -4,7 +4,6 @@ from distutils.errors import DistutilsModuleError
 import os
 import sys
 
-from pkg_resources import Distribution, PathMetadata
 from .._path import ensure_directory
 
 
@@ -16,8 +15,6 @@ class install_scripts(orig.install_scripts):
         self.no_ep = False
 
     def run(self):
-        import setuptools.command.easy_install as ei
-
         self.run_command("egg_info")
         if self.distribution.scripts:
             orig.install_scripts.run(self)  # run first to set up self.outfiles
@@ -26,6 +23,12 @@ class install_scripts(orig.install_scripts):
         if self.no_ep:
             # don't install entry point scripts into .egg file!
             return
+        self._install_ep_scripts()
+
+    def _install_ep_scripts(self):
+        # Delay import side-effects
+        from pkg_resources import Distribution, PathMetadata
+        from . import easy_install as ei
 
         ei_cmd = self.get_finalized_command("egg_info")
         dist = Distribution(