cpython/Lib/test/test_cppext.py

89 lines
3.1 KiB
Python

# 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 shutil
import sys
import unittest
import subprocess
import sysconfig
from test import support
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):
venv_dir = 'env'
with support.setup_venv_with_pip_setuptools_wheel(venv_dir) as python_exe:
self._check_build(std_cpp03, extension_name, python_exe)
def _check_build(self, std_cpp03, extension_name, python_exe):
pkg_dir = 'pkg'
os.mkdir(pkg_dir)
shutil.copy(SETUP_TESTCPPEXT, os.path.join(pkg_dir, "setup.py"))
def run_cmd(operation, cmd):
env = os.environ.copy()
env['CPYTHON_TEST_CPP_STD'] = 'c++03' if std_cpp03 else 'c++11'
env['CPYTHON_TEST_EXT_NAME'] = extension_name
if support.verbose:
print('Run:', ' '.join(cmd))
subprocess.run(cmd, check=True, env=env)
else:
proc = subprocess.run(cmd,
env=env,
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 and install the C++ extension
cmd = [python_exe, '-X', 'dev',
'-m', 'pip', 'install', '--no-build-isolation',
os.path.abspath(pkg_dir)]
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_exe,
'-X', 'dev',
'-X', 'showrefcount',
'-c', 'pass']
run_cmd('Reference run', cmd)
# Import the C++ extension
cmd = [python_exe,
'-X', 'dev',
'-X', 'showrefcount',
'-c', f"import {extension_name}"]
run_cmd('Import', cmd)
if __name__ == "__main__":
unittest.main()