bpo-39432: Implement PEP-489 algorithm for non-ascii "PyInit_*" symbol names in distutils (GH-18150)



Make it export the correct init symbol also on Windows.



https://bugs.python.org/issue39432

When checking `setup.py` and when the `author` field was provided, but
the `author_email` field was missing, erroneously a warning message was
displayed that the `author_email` field is required.

The specs do not require the `author_email`field:
https://packaging.python.org/specifications/core-metadata/#author

The same is valid for `maintainer` and `maintainer_email`.

The warning message has been adjusted.

modified:   Doc/distutils/examples.rst
modified:   Lib/distutils/command/check.py


https://bugs.python.org/issue38914

Provides a richer platform tag for AIX that we expect to be sufficient for PEP 425
binary distribution identification. Any backports to earlier Python versions will be
handled via setuptools.

Patch by Michael Felt.

https://bugs.python.org/issue37965


https://bugs.python.org/issue37965



Automerge-Triggered-By: @benjaminp

They now return NotImplemented for unsupported type of the other operand.

When building packages (e.g. for openSUSE Linux)
(random) filesystem order of input files
influences ordering of functions in the output .so files.
Thus without the patch, builds (in disposable VMs) would usually differ.

Without this patch, all callers have to be patched individually
https://github.com/dugsong/libdnet/pull/42
https://github.com/sass/libsass-python/pull/212
https://github.com/tahoe-lafs/pycryptopp/pull/41
https://github.com/yt-project/yt/pull/2206
https://github.com/pyproj4/pyproj/pull/142
https://github.com/pytries/datrie/pull/49
https://github.com/Roche/pyreadstat/pull/37
but that is an infinite effort.

See https://reproducible-builds.org/ for why this matters.

The distutils bdist_wininst command is now deprecated, use
bdist_wheel (wheel packages) instead.

test_distutils.test_build_ext() is now able to remove the temporary
directory on Windows: don't import the newly built C extension ("xx")
in the current process, but test it in a separated process.

bdist_wininst depends on MBCS codec, unavailable on non-Windows,
and bdist_wininst have not worked since at least Python 3.2, possibly
never on Python 3.

Here we document that bdist_wininst is only supported on Windows,
and we mark it unsupported otherwise to skip tests.

Distributors of Python 3 can now safely drop the bdist_wininst .exe files
without the need to skip bdist_wininst related tests.

It is also possible to link against a library or executable with a
statically linked libpython, but not both with the same DLL.  In fact
building a statically linked python is currently broken on Cygwin
for other (related) reasons.

The same problem applies to other POSIX-like layers over Windows
(MinGW, MSYS) but Python's build system does not seem to attempt
to support those platforms at the moment.

On Unix, C extensions are no longer linked to libpython.

It is now possible to load a C extension built using a shared library
Python with a statically linked Python.

When Python is embedded, libpython must not be loaded with
RTLD_LOCAL, but RTLD_GLOBAL instead. Previously, using RTLD_LOCAL, it
was already not possible to load C extensions which were not linked
to libpython, like C extensions of the standard library built by the
"*shared*" section of Modules/Setup.

distutils, python-config and python-config.py have been modified.

bpo-28552, bpo-7774: Fix distutils.sysconfig if sys.executable is
None or an empty string: use os.getcwd() to initialize project_base.

Fix also the distutils build command: don't use sys.executable if
it's evaluated as false (None or empty string).

shutil.which() and distutils.spawn.find_executable() now use
os.confstr("CS_PATH") if available instead of os.defpath, if the PATH
environment variable is not set.

Don't use os.confstr("CS_PATH") nor os.defpath if the PATH
environment variable is set to an empty string to mimick Unix 'which'
command behavior.

Changes:

* find_executable() now starts by checking for the executable in the
  current working directly case. Add an explicit
  "if not path: return None".
* Add tests for PATH='' (empty string), PATH=':' and for PATHEXT.

Set CUSTOMIZED_OSX_COMPILER to True to disable
_osx_support.customize_compiler().

The test test_customize_compiler() now mocks all sysconfig variables
and all environment variables used by customize_compiler().

Fix CFLAGS in customize_compiler() of distutils.sysconfig: when the
CFLAGS environment variable is defined, don't override CFLAGS variable with
the OPT variable anymore.

Initial patch written by David Malcolm.
Co-Authored-By: David Malcolm <dmalcolm@redhat.com>

For C++ extensions, distutils tries to replace the C compiler with the
C++ compiler, but it assumes that C compiler is the first element after
any environment variables set. On AIX, linking goes through ld_so_aix,
so it is the first element and the compiler is the next element. Thus
the replacement is faulty:

ld_so_aix gcc ... -> g++ gcc ...

Also, it assumed that self.compiler_cxx had only 1 element or that
there were the same number of elements as the linker has and in the
same order. This might not be the case, so instead concatenate
everything together.

Command line options for the xlc compiler behave differently from gcc and clang,
so skip this test case for now when xlc is the compiler.

Patch by aixtools (Michael Felt)

check_environ() of distutils.utils now catchs KeyError on calling
pwd.getpwuid(): don't create the HOME environment variable in this
case.

platform.dist() is deprecated and slated for removal in Python 3.8. The
upload command itself should also not be used to upload to PyPI, but
while it continues to exist it should not use deprecated functions.

Two kind of mistakes:

1. Missed space. After concatenating there is no space between words.

2. Missed comma. Causes unintentional concatenating in a list of strings.