# gh-116869: Build a basic C test extension to check that the Python C API
# does not emit C compiler warnings.
#
# The Python C API must be compatible with building
# with the -Werror=declaration-after-statement compiler flag.
import os.path
import shlex
import shutil
import subprocess
import unittest
from test import support
SOURCE = os.path.join(os.path.dirname(__file__), 'extension.c')
SETUP = os.path.join(os.path.dirname(__file__), 'setup.py')
# With MSVC on a debug build, the linker fails with: cannot open file
# 'python311.lib', it should look 'python311_d.lib'.
@unittest.skipIf(support.MS_WINDOWS and support.Py_DEBUG,
'test fails on Windows debug build')
# Building and running an extension in clang sanitizing mode is not
# straightforward
@support.skip_if_sanitizer('test does not work with analyzing builds',
address=True, memory=True, ub=True, thread=True)
# the test uses venv+pip: skip if it's not available
@support.requires_venv_with_pip()
@support.requires_subprocess()
@support.requires_resource('cpu')
class TestExt(unittest.TestCase):
# Default build with no options
def test_build(self):
self.check_build('_test_cext')
def test_build_c11(self):
self.check_build('_test_c11_cext', std='c11')
@unittest.skipIf(support.MS_WINDOWS, "MSVC doesn't support /std:c99")
def test_build_c99(self):
self.check_build('_test_c99_cext', std='c99')
@support.requires_gil_enabled('incompatible with Free Threading')
def test_build_limited(self):
self.check_build('_test_limited_cext', limited=True)
@support.requires_gil_enabled('broken for now with Free Threading')
def test_build_limited_c11(self):
self.check_build('_test_limited_c11_cext', limited=True, std='c11')
def check_build(self, extension_name, std=None, limited=False):
venv_dir = 'env'
with support.setup_venv_with_pip_setuptools_wheel(venv_dir) as python_exe:
self._check_build(extension_name, python_exe,
std=std, limited=limited)
def _check_build(self, extension_name, python_exe, std, limited):
pkg_dir = 'pkg'
os.mkdir(pkg_dir)
shutil.copy(SETUP, os.path.join(pkg_dir, os.path.basename(SETUP)))
shutil.copy(SOURCE, os.path.join(pkg_dir, os.path.basename(SOURCE)))
def run_cmd(operation, cmd):
env = os.environ.copy()
if std:
env['CPYTHON_TEST_STD'] = std
if limited:
env['CPYTHON_TEST_LIMITED'] = '1'
env['CPYTHON_TEST_EXT_NAME'] = extension_name
if support.verbose:
print('Run:', ' '.join(map(shlex.quote, 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('Run:', ' '.join(map(shlex.quote, cmd)))
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)]
if support.verbose:
cmd.append('-v')
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()
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