[3.11] gh-108303: Add Lib/test/test_cppext/ sub-directory (#108325) (#108336)

gh-108303: Add Lib/test/test_cppext/ sub-directory (#108325)

* Move test_cppext to its own directory
* Rename setup_testcppext.py to setup.py
* Rename _testcppext.cpp to extension.cpp
* The source (extension.cpp) is now also copied by the test.

(cherry picked from commit 21dda09600)

Lib/test/test_cppext.py

@@ -1,105 +0,0 @@
-# gh-91321: Build a basic C++ test extension to check that the Python C API is
-# compatible with C++ and does not emit C++ compiler warnings.
-import os.path
-import sys
-import unittest
-import subprocess
-import sysconfig
-from test import support
-from test.support import os_helper
-
-
-MS_WINDOWS = (sys.platform == 'win32')
-
-
-SETUP_TESTCPPEXT = support.findfile('setup_testcppext.py')
-
-
-@support.requires_subprocess()
-class TestCPPExt(unittest.TestCase):
-    def test_build_cpp11(self):
-        self.check_build(False, '_testcpp11ext')
-
-    def test_build_cpp03(self):
-        self.check_build(True, '_testcpp03ext')
-
-    # With MSVC, the linker fails with: cannot open file 'python311.lib'
-    # https://github.com/python/cpython/pull/32175#issuecomment-1111175897
-    @unittest.skipIf(MS_WINDOWS, 'test fails on Windows')
-    # Building and running an extension in clang sanitizing mode is not
-    # straightforward
-    @unittest.skipIf(
-        '-fsanitize' in (sysconfig.get_config_var('PY_CFLAGS') or ''),
-        'test does not work with analyzing builds')
-    # the test uses venv+pip: skip if it's not available
-    @support.requires_venv_with_pip()
-    def check_build(self, std_cpp03, extension_name):
-        # Build in a temporary directory
-        with os_helper.temp_cwd():
-            self._check_build(std_cpp03, extension_name)
-
-    def _check_build(self, std_cpp03, extension_name):
-        venv_dir = 'env'
-        verbose = support.verbose
-
-        # Create virtual environment to get setuptools
-        cmd = [sys.executable, '-X', 'dev', '-m', 'venv', venv_dir]
-        if verbose:
-            print()
-            print('Run:', ' '.join(cmd))
-        subprocess.run(cmd, check=True)
-
-        # Get the Python executable of the venv
-        python_exe = 'python'
-        if sys.executable.endswith('.exe'):
-            python_exe += '.exe'
-        if MS_WINDOWS:
-            python = os.path.join(venv_dir, 'Scripts', python_exe)
-        else:
-            python = os.path.join(venv_dir, 'bin', python_exe)
-
-        def run_cmd(operation, cmd):
-            if verbose:
-                print('Run:', ' '.join(cmd))
-                subprocess.run(cmd, check=True)
-            else:
-                proc = subprocess.run(cmd,
-                                      stdout=subprocess.PIPE,
-                                      stderr=subprocess.STDOUT,
-                                      text=True)
-                if proc.returncode:
-                    print(proc.stdout, end='')
-                    self.fail(
-                        f"{operation} failed with exit code {proc.returncode}")
-
-        # Build the C++ extension
-        cmd = [python, '-X', 'dev',
-               SETUP_TESTCPPEXT, 'build_ext', '--verbose']
-        if std_cpp03:
-            cmd.append('-std=c++03')
-        run_cmd('Build', cmd)
-
-        # Install the C++ extension
-        cmd = [python, '-X', 'dev',
-               SETUP_TESTCPPEXT, 'install']
-        run_cmd('Install', cmd)
-
-        # Do a reference run. Until we test that running python
-        # doesn't leak references (gh-94755), run it so one can manually check
-        # -X showrefcount results against this baseline.
-        cmd = [python,
-               '-X', 'dev',
-               '-X', 'showrefcount',
-               '-c', 'pass']
-        run_cmd('Reference run', cmd)
-
-        # Import the C++ extension
-        cmd = [python,
-               '-X', 'dev',
-               '-X', 'showrefcount',
-               '-c', f"import {extension_name}"]
-        run_cmd('Import', cmd)
-
-
-if __name__ == "__main__":
-    unittest.main()