Merge monkeypatch-module

6 files changed, 245 insertions, 212 deletions

diff --git a/CHANGES.rst b/CHANGES.rst
index 9a48c1cb..35e69661 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -2,6 +2,11 @@
 CHANGES
 =======
 
+v27.1.0
+-------
+
+* Introduce the (private) ``monkey`` module to encapsulate
+  the distutils monkeypatching behavior.
 
 v27.0.0
 -------
diff --git a/setuptools/__init__.py b/setuptools/__init__.py
index 2ca97103..41b590d7 100644
--- a/setuptools/__init__.py
+++ b/setuptools/__init__.py
@@ -1,11 +1,9 @@
 """Extensions to the 'distutils' for large or complex distributions"""
 
 import os
-import sys
 import functools
 import distutils.core
 import distutils.filelist
-from distutils.core import Command as _Command
 from distutils.util import convert_path
 from fnmatch import fnmatchcase
 
@@ -13,8 +11,9 @@ from setuptools.extern.six.moves import filterfalse, map
 
 import setuptools.version
 from setuptools.extension import Extension
-from setuptools.dist import Distribution, Feature, _get_unpatched
+from setuptools.dist import Distribution, Feature
 from setuptools.depends import Require
+from . import monkey
 
 __all__ = [
     'setup', 'Distribution', 'Feature', 'Command', 'Extension', 'Require',
@@ -122,7 +121,7 @@ find_packages = PackageFinder.find
 
 setup = distutils.core.setup
 
-_Command = _get_unpatched(_Command)
+_Command = monkey.get_unpatched(distutils.core.Command)
 
 
 class Command(_Command):
@@ -144,10 +143,6 @@ class Command(_Command):
         return cmd
 
 
-# we can't patch distutils.cmd, alas
-distutils.core.Command = Command
-
-
 def _find_all_simple(path):
     """
     Find all files under 'path'
@@ -172,31 +167,4 @@ def findall(dir=os.curdir):
     return list(files)
 
 
-has_issue_12885 = (
-    sys.version_info < (3, 4, 6)
-    or
-    (3, 5) < sys.version_info <= (3, 5, 3)
-    or
-    (3, 6) < sys.version_info
-)
-
-if has_issue_12885:
-    # fix findall bug in distutils (http://bugs.python.org/issue12885)
-    distutils.filelist.findall = findall
-
-
-needs_warehouse = (
-    sys.version_info < (2, 7, 13)
-    or
-    (3, 0) < sys.version_info < (3, 3, 7)
-    or
-    (3, 4) < sys.version_info < (3, 4, 6)
-    or
-    (3, 5) < sys.version_info <= (3, 5, 3)
-    or
-    (3, 6) < sys.version_info
-)
-
-if needs_warehouse:
-    warehouse = 'https://upload.pypi.org/legacy/'
-    distutils.config.PyPIRCCommand.DEFAULT_REPOSITORY = warehouse
+monkey.patch_all()
diff --git a/setuptools/dist.py b/setuptools/dist.py
index 820df6d5..b004f928 100644
--- a/setuptools/dist.py
+++ b/setuptools/dist.py
@@ -2,14 +2,12 @@ __all__ = ['Distribution']
 
 import re
 import os
-import sys
 import warnings
 import numbers
 import distutils.log
 import distutils.core
 import distutils.cmd
 import distutils.dist
-from distutils.core import Distribution as _Distribution
 from distutils.errors import (DistutilsOptionError, DistutilsPlatformError,
     DistutilsSetupError)
 from distutils.util import rfc822_escape
@@ -20,100 +18,66 @@ from pkg_resources.extern import packaging
 
 from setuptools.depends import Require
 from setuptools import windows_support
+from setuptools.monkey import get_unpatched
 import pkg_resources
 
 
 def _get_unpatched(cls):
-    """Protect against re-patching the distutils if reloaded
+    warnings.warn("Do not call this function", DeprecationWarning)
+    return get_unpatched(cls)
 
-    Also ensures that no other distutils extension monkeypatched the distutils
-    first.
-    """
-    while cls.__module__.startswith('setuptools'):
-        cls, = cls.__bases__
-    if not cls.__module__.startswith('distutils'):
-        raise AssertionError(
-            "distutils has already been patched by %r" % cls
-        )
-    return cls
-
-
-_Distribution = _get_unpatched(_Distribution)
-
-
-def _patch_distribution_metadata_write_pkg_file():
-    """Patch write_pkg_file to also write Requires-Python/Requires-External"""
-
-    # Based on Python 3.5 version
-    def write_pkg_file(self, file):
-        """Write the PKG-INFO format data to a file object.
-        """
-        version = '1.0'
-        if (self.provides or self.requires or self.obsoletes or
-                self.classifiers or self.download_url):
-            version = '1.1'
-        # Setuptools specific for PEP 345
-        if hasattr(self, 'python_requires'):
-            version = '1.2'
-
-        file.write('Metadata-Version: %s\n' % version)
-        file.write('Name: %s\n' % self.get_name())
-        file.write('Version: %s\n' % self.get_version())
-        file.write('Summary: %s\n' % self.get_description())
-        file.write('Home-page: %s\n' % self.get_url())
-        file.write('Author: %s\n' % self.get_contact())
-        file.write('Author-email: %s\n' % self.get_contact_email())
-        file.write('License: %s\n' % self.get_license())
-        if self.download_url:
-            file.write('Download-URL: %s\n' % self.download_url)
-
-        long_desc = rfc822_escape(self.get_long_description())
-        file.write('Description: %s\n' % long_desc)
-
-        keywords = ','.join(self.get_keywords())
-        if keywords:
-            file.write('Keywords: %s\n' % keywords)
-
-        self._write_list(file, 'Platform', self.get_platforms())
-        self._write_list(file, 'Classifier', self.get_classifiers())
-
-        # PEP 314
-        self._write_list(file, 'Requires', self.get_requires())
-        self._write_list(file, 'Provides', self.get_provides())
-        self._write_list(file, 'Obsoletes', self.get_obsoletes())
 
-        # Setuptools specific for PEP 345
-        if hasattr(self, 'python_requires'):
-            file.write('Requires-Python: %s\n' % self.python_requires)
-
-    distutils.dist.DistributionMetadata.write_pkg_file = write_pkg_file
-
-
-_patch_distribution_metadata_write_pkg_file()
-
-
-def _patch_distribution_metadata_write_pkg_info():
+# Based on Python 3.5 version
+def write_pkg_file(self, file):
+    """Write the PKG-INFO format data to a file object.
     """
-    Workaround issue #197 - Python 3 prior to 3.2.2 uses an environment-local
-    encoding to save the pkg_info. Monkey-patch its write_pkg_info method to
-    correct this undesirable behavior.
+    version = '1.0'
+    if (self.provides or self.requires or self.obsoletes or
+            self.classifiers or self.download_url):
+        version = '1.1'
+    # Setuptools specific for PEP 345
+    if hasattr(self, 'python_requires'):
+        version = '1.2'
+
+    file.write('Metadata-Version: %s\n' % version)
+    file.write('Name: %s\n' % self.get_name())
+    file.write('Version: %s\n' % self.get_version())
+    file.write('Summary: %s\n' % self.get_description())
+    file.write('Home-page: %s\n' % self.get_url())
+    file.write('Author: %s\n' % self.get_contact())
+    file.write('Author-email: %s\n' % self.get_contact_email())
+    file.write('License: %s\n' % self.get_license())
+    if self.download_url:
+        file.write('Download-URL: %s\n' % self.download_url)
+
+    long_desc = rfc822_escape(self.get_long_description())
+    file.write('Description: %s\n' % long_desc)
+
+    keywords = ','.join(self.get_keywords())
+    if keywords:
+        file.write('Keywords: %s\n' % keywords)
+
+    self._write_list(file, 'Platform', self.get_platforms())
+    self._write_list(file, 'Classifier', self.get_classifiers())
+
+    # PEP 314
+    self._write_list(file, 'Requires', self.get_requires())
+    self._write_list(file, 'Provides', self.get_provides())
+    self._write_list(file, 'Obsoletes', self.get_obsoletes())
+
+    # Setuptools specific for PEP 345
+    if hasattr(self, 'python_requires'):
+        file.write('Requires-Python: %s\n' % self.python_requires)
+
+
+# from Python 3.4
+def write_pkg_info(self, base_dir):
+    """Write the PKG-INFO file into the release tree.
     """
-    environment_local = (3,) <= sys.version_info[:3] < (3, 2, 2)
-    if not environment_local:
-        return
-
-    # from Python 3.4
-    def write_pkg_info(self, base_dir):
-        """Write the PKG-INFO file into the release tree.
-        """
-        with open(os.path.join(base_dir, 'PKG-INFO'), 'w',
-                  encoding='UTF-8') as pkg_info:
-            self.write_pkg_file(pkg_info)
+    with open(os.path.join(base_dir, 'PKG-INFO'), 'w',
+              encoding='UTF-8') as pkg_info:
+        self.write_pkg_file(pkg_info)
 
-    distutils.dist.DistributionMetadata.write_pkg_info = write_pkg_info
-
-
-_patch_distribution_metadata_write_pkg_info()
 
 sequence = tuple, list
 
@@ -245,6 +209,9 @@ def check_packages(dist, attr, value):
             )
 
 
+_Distribution = get_unpatched(distutils.core.Distribution)
+
+
 class Distribution(_Distribution):
     """Distribution with support for features, tests, and package data
 
@@ -792,11 +759,6 @@ class Distribution(_Distribution):
                 sys.stdout.detach(), encoding, errors, newline, line_buffering)
 
 
-# Install it throughout the distutils
-for module in distutils.dist, distutils.core, distutils.cmd:
-    module.Distribution = Distribution
-
-
 class Feature:
     """
     **deprecated** -- The `Feature` facility was never completely implemented
diff --git a/setuptools/extension.py b/setuptools/extension.py
index f8058b72..03068d35 100644
--- a/setuptools/extension.py
+++ b/setuptools/extension.py
@@ -1,4 +1,3 @@
-import sys
 import re
 import functools
 import distutils.core
@@ -7,12 +6,7 @@ import distutils.extension
 
 from setuptools.extern.six.moves import map
 
-from .dist import _get_unpatched
-from . import msvc
-
-_Extension = _get_unpatched(distutils.core.Extension)
-
-msvc.patch_for_specialized_compiler()
+from .monkey import get_unpatched
 
 
 def _have_cython():
@@ -33,6 +27,9 @@ def _have_cython():
 have_pyrex = _have_cython
 
 
+_Extension = get_unpatched(distutils.core.Extension)
+
+
 class Extension(_Extension):
     """Extension that uses '.c' files in place of '.pyx' files"""
 
@@ -59,9 +56,3 @@ class Extension(_Extension):
 
 class Library(Extension):
     """Just like a regular Extension, but built as a library instead"""
-
-
-distutils.core.Extension = Extension
-distutils.extension.Extension = Extension
-if 'distutils.command.build_ext' in sys.modules:
-    sys.modules['distutils.command.build_ext'].Extension = Extension
diff --git a/setuptools/monkey.py b/setuptools/monkey.py
new file mode 100644
index 00000000..5a0cf43b
--- /dev/null
+++ b/setuptools/monkey.py
@@ -0,0 +1,155 @@
+"""
+Monkey patching of distutils.
+"""
+
+import sys
+import distutils.filelist
+import platform
+
+import setuptools
+
+
+__all__ = []
+"""
+Everything is private. Contact the project team
+if you think you need this functionality.
+"""
+
+
+def get_unpatched(cls):
+    """Protect against re-patching the distutils if reloaded
+
+    Also ensures that no other distutils extension monkeypatched the distutils
+    first.
+    """
+    while cls.__module__.startswith('setuptools'):
+        cls, = cls.__bases__
+    if not cls.__module__.startswith('distutils'):
+        raise AssertionError(
+            "distutils has already been patched by %r" % cls
+        )
+    return cls
+
+
+def patch_all():
+    # we can't patch distutils.cmd, alas
+    distutils.core.Command = setuptools.Command
+
+    has_issue_12885 = (
+        sys.version_info < (3, 4, 6)
+        or
+        (3, 5) < sys.version_info <= (3, 5, 3)
+        or
+        (3, 6) < sys.version_info
+    )
+
+    if has_issue_12885:
+        # fix findall bug in distutils (http://bugs.python.org/issue12885)
+        distutils.filelist.findall = setuptools.findall
+
+    needs_warehouse = (
+        sys.version_info < (2, 7, 13)
+        or
+        (3, 0) < sys.version_info < (3, 3, 7)
+        or
+        (3, 4) < sys.version_info < (3, 4, 6)
+        or
+        (3, 5) < sys.version_info <= (3, 5, 3)
+        or
+        (3, 6) < sys.version_info
+    )
+
+    if needs_warehouse:
+        warehouse = 'https://upload.pypi.org/legacy/'
+        distutils.config.PyPIRCCommand.DEFAULT_REPOSITORY = warehouse
+
+    _patch_distribution_metadata_write_pkg_file()
+    _patch_distribution_metadata_write_pkg_info()
+
+    # Install Distribution throughout the distutils
+    for module in distutils.dist, distutils.core, distutils.cmd:
+        module.Distribution = setuptools.dist.Distribution
+
+    # Install the patched Extension
+    distutils.core.Extension = setuptools.extension.Extension
+    distutils.extension.Extension = setuptools.extension.Extension
+    if 'distutils.command.build_ext' in sys.modules:
+        sys.modules['distutils.command.build_ext'].Extension = (
+            setuptools.extension.Extension
+        )
+
+    patch_for_msvc_specialized_compiler()
+
+
+def _patch_distribution_metadata_write_pkg_file():
+    """Patch write_pkg_file to also write Requires-Python/Requires-External"""
+    distutils.dist.DistributionMetadata.write_pkg_file = (
+        setuptools.dist.write_pkg_file
+    )
+
+
+def _patch_distribution_metadata_write_pkg_info():
+    """
+    Workaround issue #197 - Python 3 prior to 3.2.2 uses an environment-local
+    encoding to save the pkg_info. Monkey-patch its write_pkg_info method to
+    correct this undesirable behavior.
+    """
+    environment_local = (3,) <= sys.version_info[:3] < (3, 2, 2)
+    if not environment_local:
+        return
+
+    distutils.dist.DistributionMetadata.write_pkg_info = (
+        setuptools.dist.write_pkg_info
+    )
+
+
+unpatched = dict()
+
+
+def patch_for_msvc_specialized_compiler():
+    """
+    Patch functions in distutils to use standalone Microsoft Visual C++
+    compilers.
+    """
+    try:
+        # Distutil file for MSVC++ 9.0 and upper (Python 2.7 to 3.4)
+        import distutils.msvc9compiler as msvc9compiler
+    except ImportError:
+        pass
+
+    try:
+        # Distutil file for MSVC++ 14.0 and upper (Python 3.5+)
+        import distutils._msvccompiler as msvc14compiler
+    except ImportError:
+        pass
+
+    if platform.system() != 'Windows':
+        # Compilers only availables on Microsoft Windows
+        return
+
+    if unpatched:
+        # Already patched
+        return
+
+    try:
+        # Patch distutils.msvc9compiler
+        unpatched['msvc9_find_vcvarsall'] = msvc9compiler.find_vcvarsall
+        msvc9compiler.find_vcvarsall = msvc9_find_vcvarsall
+        unpatched['msvc9_query_vcvarsall'] = msvc9compiler.query_vcvarsall
+        msvc9compiler.query_vcvarsall = msvc9_query_vcvarsall
+    except NameError:
+        pass
+
+    try:
+        # Patch distutils._msvccompiler._get_vc_env
+        unpatched['msvc14_get_vc_env'] = msvc14compiler._get_vc_env
+        msvc14compiler._get_vc_env = msvc14_get_vc_env
+    except NameError:
+        pass
+
+    try:
+        # Patch distutils._msvccompiler.gen_lib_options for Numpy
+        unpatched['msvc14_gen_lib_options'] = msvc14compiler.gen_lib_options
+        msvc14compiler.gen_lib_options = msvc14_gen_lib_options
+    except NameError:
+        pass
diff --git a/setuptools/msvc.py b/setuptools/msvc.py
index ecbea818..a902a4a7 100644
--- a/setuptools/msvc.py
+++ b/setuptools/msvc.py
@@ -1,6 +1,20 @@
 """
-This module adds improved support for Microsoft Visual C++ compilers.
+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 7.0 (x86, x64, ia64);
+    Microsoft Windows SDK 6.1 (x86, x64, ia64)
+
+Microsoft Visual C++ 10.0:
+    Microsoft Windows SDK 7.1 (x86, x64, ia64)
+
+Microsoft Visual C++ 14.0:
+    Microsoft Visual C++ Build Tools 2015 (x86, x64, arm)
 """
+
 import os
 import sys
 import platform
@@ -10,6 +24,8 @@ from pkg_resources.extern.packaging.version import LegacyVersion
 
 from setuptools.extern.six.moves import filterfalse
 
+from . import monkey
+
 if platform.system() == 'Windows':
     from setuptools.extern.six.moves import winreg
     safe_env = os.environ
@@ -26,74 +42,10 @@ else:
     safe_env = dict()
 
 try:
-    # Distutil file for MSVC++ 9.0 and upper (Python 2.7 to 3.4)
-    import distutils.msvc9compiler as msvc9compiler
+    from distutils.msvc9compiler import Reg
 except ImportError:
     pass
 
-try:
-    # Distutil file for MSVC++ 14.0 and upper (Python 3.5+)
-    import distutils._msvccompiler as msvc14compiler
-except ImportError:
-    pass
-
-
-unpatched = dict()
-
-
-def patch_for_specialized_compiler():
-    """
-    Patch functions in distutils to use standalone 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 7.0 (x86, x64, ia64);
-        Microsoft Windows SDK 6.1 (x86, x64, ia64)
-
-    Microsoft Visual C++ 10.0:
-        Microsoft Windows SDK 7.1 (x86, x64, ia64)
-
-    Microsoft Visual C++ 14.0:
-        Microsoft Visual C++ Build Tools 2015 (x86, x64, arm)
-    """
-    if platform.system() != 'Windows':
-        # Compilers only availables on Microsoft Windows
-        return
-
-    if 'distutils' not in globals():
-        # The module isn't available to be patched
-        return
-
-    if unpatched:
-        # Already patched
-        return
-
-    try:
-        # Patch distutils.msvc9compiler
-        unpatched['msvc9_find_vcvarsall'] = msvc9compiler.find_vcvarsall
-        msvc9compiler.find_vcvarsall = msvc9_find_vcvarsall
-        unpatched['msvc9_query_vcvarsall'] = msvc9compiler.query_vcvarsall
-        msvc9compiler.query_vcvarsall = msvc9_query_vcvarsall
-    except NameError:
-        pass
-
-    try:
-        # Patch distutils._msvccompiler._get_vc_env
-        unpatched['msvc14_get_vc_env'] = msvc14compiler._get_vc_env
-        msvc14compiler._get_vc_env = msvc14_get_vc_env
-    except NameError:
-        pass
-
-    try:
-        # Patch distutils._msvccompiler.gen_lib_options for Numpy
-        unpatched['msvc14_gen_lib_options'] = msvc14compiler.gen_lib_options
-        msvc14compiler.gen_lib_options = msvc14_gen_lib_options
-    except NameError:
-        pass
-
 
 def msvc9_find_vcvarsall(version):
     """
@@ -117,7 +69,6 @@ def msvc9_find_vcvarsall(version):
     ------
     vcvarsall.bat path: str
     """
-    Reg = msvc9compiler.Reg
     VC_BASE = r'Software\%sMicrosoft\DevDiv\VCForPython\%0.1f'
     key = VC_BASE % ('', version)
     try:
@@ -136,7 +87,7 @@ def msvc9_find_vcvarsall(version):
         if os.path.isfile(vcvarsall):
             return vcvarsall
 
-    return unpatched['msvc9_find_vcvarsall'](version)
+    return monkey.unpatched['msvc9_find_vcvarsall'](version)
 
 
 def msvc9_query_vcvarsall(ver, arch='x86', *args, **kwargs):
@@ -169,7 +120,8 @@ def msvc9_query_vcvarsall(ver, arch='x86', *args, **kwargs):
     """
     # Try to get environement from vcvarsall.bat (Classical way)
     try:
-        return unpatched['msvc9_query_vcvarsall'](ver, arch, *args, **kwargs)
+        orig = monkey.unpatched['msvc9_query_vcvarsall']
+        return orig(ver, arch, *args, **kwargs)
     except distutils.errors.DistutilsPlatformError:
         # Pass error if Vcvarsall.bat is missing
         pass
@@ -208,7 +160,7 @@ def msvc14_get_vc_env(plat_spec):
     """
     # Try to get environment from vcvarsall.bat (Classical way)
     try:
-        return unpatched['msvc14_get_vc_env'](plat_spec)
+        return monkey.unpatched['msvc14_get_vc_env'](plat_spec)
     except distutils.errors.DistutilsPlatformError:
         # Pass error Vcvarsall.bat is missing
         pass
@@ -231,7 +183,7 @@ def msvc14_gen_lib_options(*args, **kwargs):
         import numpy as np
         if LegacyVersion(np.__version__) < LegacyVersion('1.11.2'):
             return np.distutils.ccompiler.gen_lib_options(*args, **kwargs)
-    return unpatched['msvc14_gen_lib_options'](*args, **kwargs)
+    return monkey.unpatched['msvc14_gen_lib_options'](*args, **kwargs)
 
 
 def _augment_exception(exc, version, arch=''):