bpo-40137: Add pycore_moduleobject.h internal header (GH-25507)

Add pycore_moduleobject.h internal header file with static inline
functions to access module members:

* _PyModule_GetDict()
* _PyModule_GetDef()
* _PyModule_GetState()

These functions don't check at runtime if their argument has a valid
type and can be inlined even if Python is not built with LTO.

_PyType_GetModuleByDef() uses _PyModule_GetDef().

Replace PyModule_GetState() with _PyModule_GetState() in the
extension modules, considered as performance sensitive:

* _abc
* _functools
* _operator
* _pickle
* _queue
* _random
* _sre
* _struct
* _thread
* _winapi
* array
* posix

The following extensions are now built with the Py_BUILD_CORE_MODULE
macro defined, to be able to use the internal pycore_moduleobject.h
header: _abc, array, _operator, _queue, _sre, _struct.

1 files changed, 42 insertions, 0 deletions

diff --git a/Include/internal/pycore_moduleobject.h b/Include/internal/pycore_moduleobject.h
new file mode 100644
index 0000000..e9978ab
--- /dev/null
+++ b/Include/internal/pycore_moduleobject.h
@@ -0,0 +1,42 @@
+#ifndef Py_INTERNAL_MODULEOBJECT_H
+#define Py_INTERNAL_MODULEOBJECT_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef Py_BUILD_CORE
+#  error "this header requires Py_BUILD_CORE define"
+#endif
+
+typedef struct {
+    PyObject_HEAD
+    PyObject *md_dict;
+    struct PyModuleDef *md_def;
+    void *md_state;
+    PyObject *md_weaklist;
+    // for logging purposes after md_dict is cleared
+    PyObject *md_name;
+} PyModuleObject;
+
+static inline PyModuleDef* _PyModule_GetDef(PyObject *mod) {
+    assert(PyModule_Check(mod));
+    return ((PyModuleObject *)mod)->md_def;
+}
+
+static inline void* _PyModule_GetState(PyObject* mod) {
+    assert(PyModule_Check(mod));
+    return ((PyModuleObject *)mod)->md_state;
+}
+
+static inline PyObject* _PyModule_GetDict(PyObject *mod) {
+    assert(PyModule_Check(mod));
+    PyObject *dict = ((PyModuleObject *)mod) -> md_dict;
+    // _PyModule_GetDict(mod) must not be used after calling module_clear(mod)
+    assert(dict != NULL);
+    return dict;
+}
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_INTERNAL_MODULEOBJECT_H */