Add test for _Py_OPAQUE_PYOBJECT

python · encukou · Jul 12, 2025 · Jun 24, 2025 · Jul 8, 2025 · May 26, 2025
commit 33d9ae7cbeea2702baa8566617d48d855e0242f7
diff --git a/Lib/test/test_cext/__init__.py b/Lib/test/test_cext/__init__.py
@@ -12,7 +12,10 @@
 from test import support
 
 
-SOURCE = os.path.join(os.path.dirname(__file__), 'extension.c')
+SOURCES = [
+    os.path.join(os.path.dirname(__file__), 'extension.c'),
+    os.path.join(os.path.dirname(__file__), 'create_moduledef.c'),
+]
 SETUP = os.path.join(os.path.dirname(__file__), 'setup.py')
 
 
@@ -51,24 +54,32 @@ def test_build_limited(self):
     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):
+    def test_build_opaque(self):
+        # Test with _Py_OPAQUE_PYOBJECT
+        self.check_build('_test_limited_opaque_cext', limited=True, opaque=True)
+
+    def check_build(self, extension_name, std=None, limited=False, opaque=False):
         venv_dir = 'env'
         with support.setup_venv_with_pip_setuptools(venv_dir) as python_exe:
             self._check_build(extension_name, python_exe,
-                              std=std, limited=limited)
+                              std=std, limited=limited, opaque=opaque)
 
-    def _check_build(self, extension_name, python_exe, std, limited):
+    def _check_build(self, extension_name, python_exe, std, limited, opaque):
         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)))
+        for source in SOURCES:
+            dest = os.path.join(pkg_dir, os.path.basename(source))
+            shutil.copy(source, dest)
 
         def run_cmd(operation, cmd):
             env = os.environ.copy()
             if std:
                 env['CPYTHON_TEST_STD'] = std
             if limited:
                 env['CPYTHON_TEST_LIMITED'] = '1'
+            if opaque:
+                env['CPYTHON_TEST_OPAQUE_PYOBJECT'] = '1'
             env['CPYTHON_TEST_EXT_NAME'] = extension_name
             if support.verbose:
                 print('Run:', ' '.join(map(shlex.quote, cmd)))

diff --git a/Lib/test/test_cext/create_moduledef.c b/Lib/test/test_cext/create_moduledef.c
@@ -0,0 +1,29 @@
+// Workaround for testing _Py_OPAQUE_PYOBJECT.
+// See end of 'extension.c'
+
+
+#undef _Py_OPAQUE_PYOBJECT
+#undef Py_LIMITED_API
+#include "Python.h"
+
+
+// (repeated definition to avoid creating a header)
+extern PyObject *testcext_create_moduledef(
+    const char *name, const char *doc,
+    PyMethodDef *methods, PyModuleDef_Slot *slots);
+
+PyObject *testcext_create_moduledef(
+    const char *name, const char *doc,
+    PyMethodDef *methods, PyModuleDef_Slot *slots) {
+
+    static struct PyModuleDef _testcext_module = {
+        PyModuleDef_HEAD_INIT,
+    };
+    if (!_testcext_module.m_name) {
+        _testcext_module.m_name = name;
+        _testcext_module.m_doc = doc;
+        _testcext_module.m_methods = methods;
+        _testcext_module.m_slots = slots;
+    }
+    return PyModuleDef_Init(&_testcext_module);
+}
diff --git a/Lib/test/test_cext/extension.c b/Lib/test/test_cext/extension.c
@@ -58,6 +58,9 @@ _testcext_exec(
     return 0;
 }
 
+#define _FUNC_NAME(NAME) PyInit_ ## NAME
+#define FUNC_NAME(NAME) _FUNC_NAME(NAME)
+
 // Converting from function pointer to void* has undefined behavior, but
 // works on all known platforms, and CPython's module and type slots currently
 // need it.
@@ -76,9 +79,10 @@ static PyModuleDef_Slot _testcext_slots[] = {
 
 _Py_COMP_DIAG_POP
 
-
 PyDoc_STRVAR(_testcext_doc, "C test extension.");
 
+#ifndef _Py_OPAQUE_PYOBJECT
+
 static struct PyModuleDef _testcext_module = {
     PyModuleDef_HEAD_INIT,  // m_base
     STR(MODULE_NAME),  // m_name
@@ -92,11 +96,30 @@ static struct PyModuleDef _testcext_module = {
 };
 
 
-#define _FUNC_NAME(NAME) PyInit_ ## NAME
-#define FUNC_NAME(NAME) _FUNC_NAME(NAME)
-
 PyMODINIT_FUNC
 FUNC_NAME(MODULE_NAME)(void)
 {
     return PyModuleDef_Init(&_testcext_module);
 }
+
+#else  // _Py_OPAQUE_PYOBJECT
+
+// Opaque PyObject means that PyModuleDef is also opaque and cannot be
+// declared statically. See PEP 793.
+// So, this part of module creation is split into a separate source file
+// which uses non-limited API.
+
+// (repeated definition to avoid creating a header)
+extern PyObject *testcext_create_moduledef(
+    const char *name, const char *doc,
+    PyMethodDef *methods, PyModuleDef_Slot *slots);
+
+
+PyMODINIT_FUNC
+FUNC_NAME(MODULE_NAME)(void)
+{
+    return testcext_create_moduledef(
+        STR(MODULE_NAME), _testcext_doc, _testcext_methods, _testcext_slots);
+}
+
+#endif  // _Py_OPAQUE_PYOBJECT
diff --git a/Lib/test/test_cext/setup.py b/Lib/test/test_cext/setup.py
@@ -45,6 +45,9 @@ def main():
     std = os.environ.get("CPYTHON_TEST_STD", "")
     module_name = os.environ["CPYTHON_TEST_EXT_NAME"]
     limited = bool(os.environ.get("CPYTHON_TEST_LIMITED", ""))
+    opaque = bool(os.environ.get("CPYTHON_TEST_OPAQUE_PYOBJECT", ""))
+
+    sources = [SOURCE]
 
     cflags = list(CFLAGS)
     cflags.append(f'-DMODULE_NAME={module_name}')
@@ -75,6 +78,12 @@ def main():
         version = sys.hexversion
         cflags.append(f'-DPy_LIMITED_API={version:#x}')
 
+    # Define _Py_OPAQUE_PYOBJECT macro
+    if opaque:
+        version = sys.hexversion
+        cflags.append(f'-D_Py_OPAQUE_PYOBJECT')
+        sources.append('create_moduledef.c')
+
     # On Windows, add PCbuild\amd64\ to include and library directories
     include_dirs = []
     library_dirs = []
@@ -99,7 +108,7 @@ def main():
 
     ext = Extension(
         module_name,
-        sources=[SOURCE],
+        sources=sources,
         extra_compile_args=cflags,
         include_dirs=include_dirs,
         library_dirs=library_dirs)