Revert "PEP 697: Use the new type extension provision, amended"

This reverts commit adb609270e54177024fbcbd9aab7f168a7205dec.

Reason for revert: The real fix is much simpler and complete.

Change-Id: I07171bcd28fd3f9aa21ddde3130b755aecb62e7d
Pick-to: 6.6 6.7
Reviewed-by: Adrian Herrmann <adrian.herrmann@qt.io>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

3 files changed, 20 insertions, 33 deletions

diff --git a/sources/shiboken6/libshiboken/basewrapper.cpp b/sources/shiboken6/libshiboken/basewrapper.cpp
index 1ac65c00c..99aea4725 100644
--- a/sources/shiboken6/libshiboken/basewrapper.cpp
+++ b/sources/shiboken6/libshiboken/basewrapper.cpp
@@ -197,31 +197,6 @@ static PyGetSetDef SbkObjectType_tp_getset[] = {
 
 static PyTypeObject *createObjectTypeType()
 {
-    // PYSIDE-2676: When using the new type extension, we need to use an
-    //              extra meta type that provides the extra size.
-    //              This is a hairy part of Python 3.12 .
-    //
-    // The problem here is that we use the type extension both in types
-    // and also in meta types. This was invisible with extender dicts.
-    // Please study carefully:
-    // https://docs.python.org/3/c-api/type.html#c.PyType_Spec.basicsize
-
-    PyType_Slot SbkObjectTypeMeta_Type_slots[] = {
-        {Py_tp_base, static_cast<void *>(&PyType_Type)},
-        {Py_tp_alloc, reinterpret_cast<void *>(PyType_GenericAlloc)},
-        {0, nullptr}
-    };
-
-    PyType_Spec SbkObjectTypeMeta_Type_spec = {
-        "1:Shiboken.ObjectTypeMeta",
-        -long(sizeof(SbkObjectTypePrivate)),
-        0, // sizeof(PyMemberDef), not for PyPy without a __len__ defined
-        Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE|Py_TPFLAGS_TYPE_SUBCLASS,
-        SbkObjectTypeMeta_Type_slots,
-    };
-
-    auto specMeta = &SbkObjectTypeMeta_Type_spec;
-
     PyType_Slot SbkObjectType_Type_slots[] = {
         {Py_tp_dealloc, reinterpret_cast<void *>(SbkObjectType_tp_dealloc)},
         {Py_tp_getattro, reinterpret_cast<void *>(mangled_type_getattro)},
@@ -259,14 +234,9 @@ static PyTypeObject *createObjectTypeType()
         SbkObjectType_Type_slots,
     };
 
-    if (_PepRuntimeVersion() >= 0x030C00) {
-        auto *meta = SbkType_FromSpec(specMeta);
-        auto spec = &SbkObjectType_Type_spec_312;
-        return SbkType_FromSpecWithMeta(spec, meta);
-    }
-
-    auto spec = &SbkObjectType_Type_spec;
-    return SbkType_FromSpec(spec);
+    return SbkType_FromSpec(_PepRuntimeVersion() >= 0x030C00 ?
+                            &SbkObjectType_Type_spec_312 :
+                            &SbkObjectType_Type_spec);
 }
 
 PyTypeObject *SbkObjectType_TypeF(void)
@@ -363,6 +333,8 @@ static PyTypeObject *createObjectType()
                                         offsetof(SbkObject, ob_dict),
                                         offsetof(SbkObject, weakreflist),
                                         nullptr);    // bufferprocs
+    // Initialize the hidden data area.
+    _PepPostInit_SbkObject_Type(type);
     return type;
 }
 
diff --git a/sources/shiboken6/libshiboken/pep384impl.cpp b/sources/shiboken6/libshiboken/pep384impl.cpp
index 4b3759456..4826fb379 100644
--- a/sources/shiboken6/libshiboken/pep384impl.cpp
+++ b/sources/shiboken6/libshiboken/pep384impl.cpp
@@ -1092,6 +1092,18 @@ void PepType_SOTP_delete(PyTypeObject *type)
 
 #endif // !defined(Py_LIMITED_API) && PY_VERSION_HEX >= 0x030C0000
 
+void _PepPostInit_SbkObject_Type(PyTypeObject *type)
+{
+    // Special init for SbkObject_Type.
+    // A normal initialization would recurse PepType_SOTP.
+    if (_PepRuntimeVersion() >= 0x030C00) {
+        auto *obType = reinterpret_cast<PyObject *>(type);
+        void *data = PepObject_GetTypeData(obType, Py_TYPE(obType));
+        auto *sbkExt = reinterpret_cast<SbkObjectTypePrivate *>(data);
+        std::fill_n(reinterpret_cast<char *>(data), sizeof(*sbkExt), 0);
+    }
+}
+
 /*
  * SbkEnumType extender
  */
diff --git a/sources/shiboken6/libshiboken/pep384impl.h b/sources/shiboken6/libshiboken/pep384impl.h
index ec58aac81..31fd65219 100644
--- a/sources/shiboken6/libshiboken/pep384impl.h
+++ b/sources/shiboken6/libshiboken/pep384impl.h
@@ -156,6 +156,9 @@ struct SbkObjectTypePrivate;
 LIBSHIBOKEN_API SbkObjectTypePrivate *PepType_SOTP(PyTypeObject *type);
 LIBSHIBOKEN_API void PepType_SOTP_delete(PyTypeObject *type);
 
+// PYSIDE-2230: SbkObjectType needs a special init
+LIBSHIBOKEN_API void _PepPostInit_SbkObject_Type(PyTypeObject *type);
+
 struct SbkEnumType;
 struct SbkEnumTypePrivate;