1 files changed, 47 insertions, 4 deletions

diff --git a/Lib/test/test_cext/extension.c b/Lib/test/test_cext/extension.c
index 64629c5a6da..73fc67ae59d 100644
--- a/Lib/test/test_cext/extension.c
+++ b/Lib/test/test_cext/extension.c
@@ -1,11 +1,31 @@
 // gh-116869: Basic C test extension to check that the Python C API
 // does not emit C compiler warnings.
+//
+// Test also the internal C API if the TEST_INTERNAL_C_API macro is defined.
 
 // Always enable assertions
 #undef NDEBUG
 
+#ifdef TEST_INTERNAL_C_API
+#  define Py_BUILD_CORE_MODULE 1
+#endif
+
 #include "Python.h"
 
+#ifdef TEST_INTERNAL_C_API
+   // gh-135906: Check for compiler warnings in the internal C API.
+   // - Cython uses pycore_frame.h.
+   // - greenlet uses pycore_frame.h, pycore_interpframe_structs.h and
+   //   pycore_interpframe.h.
+#  include "internal/pycore_frame.h"
+#  include "internal/pycore_gc.h"
+#  include "internal/pycore_interp.h"
+#  include "internal/pycore_interpframe.h"
+#  include "internal/pycore_interpframe_structs.h"
+#  include "internal/pycore_object.h"
+#  include "internal/pycore_pystate.h"
+#endif
+
 #ifndef MODULE_NAME
 #  error "MODULE_NAME macro must be defined"
 #endif
@@ -58,6 +78,9 @@ _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 +99,10 @@ 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 +116,30 @@ 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