gh-91321: Fix compatibility with C++ older than C++11 (#93784)

Fix the compatibility of the Python C API with C++ older than C++11.

_Py_NULL is only defined as nullptr on C++11 and newer.

1 files changed, 25 insertions, 13 deletions

diff --git a/Lib/test/test_cppext.py b/Lib/test/test_cppext.py
index 9ed9061..8673911 100644
--- a/Lib/test/test_cppext.py
+++ b/Lib/test/test_cppext.py
@@ -16,22 +16,29 @@ SETUP_TESTCPPEXT = support.findfile('setup_testcppext.py')
 
 @support.requires_subprocess()
 class TestCPPExt(unittest.TestCase):
+    def test_build_cpp11(self):
+        self.check_build(False)
+
+    def test_build_cpp03(self):
+        self.check_build(True)
+
     # 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')
     # the test uses venv+pip: skip if it's not available
     @support.requires_venv_with_pip()
-    def test_build(self):
+    def check_build(self, std_cpp03):
         # Build in a temporary directory
         with os_helper.temp_cwd():
-            self._test_build()
+            self._check_build(std_cpp03)
 
-    def _test_build(self):
+    def _check_build(self, std_cpp03):
         venv_dir = 'env'
+        verbose = support.verbose
 
         # Create virtual environment to get setuptools
         cmd = [sys.executable, '-X', 'dev', '-m', 'venv', venv_dir]
-        if support.verbose:
+        if verbose:
             print()
             print('Run:', ' '.join(cmd))
         subprocess.run(cmd, check=True)
@@ -46,16 +53,21 @@ class TestCPPExt(unittest.TestCase):
             python = os.path.join(venv_dir, 'bin', python_exe)
 
         # Build the C++ extension
-        cmd = [python, '-X', 'dev', SETUP_TESTCPPEXT, 'build_ext', '--verbose']
-        if support.verbose:
+        cmd = [python, '-X', 'dev',
+               SETUP_TESTCPPEXT, 'build_ext', '--verbose']
+        if std_cpp03:
+            cmd.append('-std=c++03')
+        if verbose:
             print('Run:', ' '.join(cmd))
-        proc = subprocess.run(cmd,
-                              stdout=subprocess.PIPE,
-                              stderr=subprocess.STDOUT,
-                              text=True)
-        if proc.returncode:
-            print(proc.stdout, end='')
-            self.fail(f"Build failed with exit code {proc.returncode}")
+            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"Build failed with exit code {proc.returncode}")
 
 
 if __name__ == "__main__":