cpython/Lib/test/test_cppext.py

88 lines
2.7 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 contextlib
import os
import sys
import unittest
import warnings
from test import support
from test.support import os_helper
with warnings.catch_warnings():
warnings.simplefilter('ignore', DeprecationWarning)
from distutils.core import setup, Extension
import distutils.sysconfig
MS_WINDOWS = (sys.platform == 'win32')
SOURCE = support.findfile('_testcppext.cpp')
if not MS_WINDOWS:
# C++ compiler flags for GCC and clang
CPPFLAGS = [
# Python currently targets C++11
'-std=c++11',
# gh-91321: The purpose of _testcppext extension is to check that building
# a C++ extension using the Python C API does not emit C++ compiler
# warnings
'-Werror',
]
else:
# Don't pass any compiler flag to MSVC
CPPFLAGS = []
class TestCPPExt(unittest.TestCase):
def build(self):
cpp_ext = Extension(
'_testcppext',
sources=[SOURCE],
language='c++',
extra_compile_args=CPPFLAGS)
capture_stdout = (not support.verbose)
try:
try:
if capture_stdout:
stdout = support.captured_stdout()
else:
print()
stdout = contextlib.nullcontext()
with (stdout,
support.swap_attr(sys, 'argv', ['setup.py', 'build_ext', '--verbose'])):
setup(name="_testcppext", ext_modules=[cpp_ext])
return
except:
if capture_stdout:
# Show output on error
print()
print(stdout.getvalue())
raise
except SystemExit:
self.fail("Build failed")
# 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')
def test_build(self):
# save/restore os.environ
def restore_env(old_env):
os.environ.clear()
os.environ.update(old_env)
self.addCleanup(restore_env, dict(os.environ))
def restore_sysconfig_vars(old_config_vars):
distutils.sysconfig._config_vars.clear()
distutils.sysconfig._config_vars.update(old_config_vars)
self.addCleanup(restore_sysconfig_vars,
dict(distutils.sysconfig._config_vars))
# Build in a temporary directory
with os_helper.temp_cwd():
self.build()
if __name__ == "__main__":
unittest.main()