__feature__: Remove the no longer efficient reserved_bits structure

The reserved_bits structure is no longer an optimization
after moving to PyPy. Accessing any extra field involves
always a dict lookup.

- remove the reserved_bits field
- re-order SbkObjectTypePrivate
- replace access functions by currentSelectId()

Task-number: PSYIDE-2029
Change-Id: I08642eace9a6399649c039bcc358ce678bbd4fd3
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
(cherry picked from commit 47a9622599822d5db2dd20f13f369c671c4c4fca)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

6 files changed, 21 insertions, 46 deletions

diff --git a/sources/pyside6/libpyside/feature_select.cpp b/sources/pyside6/libpyside/feature_select.cpp
index 17c6169af..695a0e61e 100644
--- a/sources/pyside6/libpyside/feature_select.cpp
+++ b/sources/pyside6/libpyside/feature_select.cpp
@@ -153,16 +153,6 @@ static inline PyObject *getSelectId(PyObject *dict)
     return select_id;
 }
 
-static inline void setCurrentSelectId(PyTypeObject *type, PyObject *select_id)
-{
-    SbkObjectType_SetReserved(type, PyLong_AsSsize_t(select_id));
-}
-
-static inline void setCurrentSelectId(PyTypeObject *type, int id)
-{
-    SbkObjectType_SetReserved(type, id);
-}
-
 static bool replaceClassDict(PyTypeObject *type)
 {
     /*
@@ -184,7 +174,6 @@ static bool replaceClassDict(PyTypeObject *type)
     // Replace `__dict__` which usually has refcount 1 (but see cyclic_test.py)
     Py_DECREF(type->tp_dict);
     type->tp_dict = new_dict;
-    setCurrentSelectId(type, select_id.object());
     return true;
 }
 
@@ -205,7 +194,6 @@ static bool addNewDict(PyTypeObject *type, PyObject *select_id)
     setNextDict(dict, new_dict);
     setNextDict(new_dict, next_dict);
     type->tp_dict = new_dict;
-    setCurrentSelectId(type, select_id);
     return true;
 }
 
@@ -222,13 +210,11 @@ static inline bool moveToFeatureSet(PyTypeObject *type, PyObject *select_id)
         // This works because small numbers are singleton objects.
         if (current_id == select_id) {
             type->tp_dict = dict;
-            setCurrentSelectId(type, select_id);
             return true;
         }
         dict = nextInCircle(dict);
     } while (dict != initial_dict);
     type->tp_dict = initial_dict;
-    setCurrentSelectId(type, getSelectId(initial_dict));
     return false;
 }
 
@@ -261,7 +247,6 @@ static bool createNewFeatureSet(PyTypeObject *type, PyObject *select_id)
     auto id = PyLong_AsSsize_t(select_id);
     if (id == -1)
         return false;
-    setCurrentSelectId(type, id);
     FeatureProc *proc = featurePointer;
     for (int idx = id; *proc != nullptr; ++proc, idx >>= 1) {
         if (idx & 1) {
diff --git a/sources/pyside6/libpyside/pyside.cpp b/sources/pyside6/libpyside/pyside.cpp
index 6b94fc0c8..b830a3115 100644
--- a/sources/pyside6/libpyside/pyside.cpp
+++ b/sources/pyside6/libpyside/pyside.cpp
@@ -31,6 +31,7 @@
 #include <sbkconverter.h>
 #include <sbkstring.h>
 #include <sbkstaticstrings.h>
+#include <sbkfeature_base.h>
 
 #include <QtCore/QByteArray>
 #include <QtCore/QCoreApplication>
@@ -232,7 +233,7 @@ static bool _setProperty(PyObject *qObj, PyObject *name, PyObject *value, bool *
 
     QByteArray propName(Shiboken::String::toCString(name));
     auto type = Py_TYPE(qObj);
-    int flags = SbkObjectType_GetReserved(type);
+    int flags = currentSelectId(type);
     int prop_flag = flags & 0x02;
     auto found = false;
     QByteArray getterName{}, setterName{};
@@ -301,7 +302,7 @@ bool fillQtProperties(PyObject *qObj, const QMetaObject *metaObj, PyObject *kwds
 
     PyObject *key, *value;
     Py_ssize_t pos = 0;
-    int flags = SbkObjectType_GetReserved(Py_TYPE(qObj));
+    int flags = currentSelectId(Py_TYPE(qObj));
     int snake_flag = flags & 0x01;
 
     while (PyDict_Next(kwds, &pos, &key, &value)) {
@@ -517,7 +518,7 @@ PyObject *getMetaDataFromQObject(QObject *cppSelf, PyObject *self, PyObject *nam
         PyErr_Fetch(&type, &value, &traceback);     // This was omitted for a loong time.
 
         const char *cname = Shiboken::String::toCString(name);
-        int flags = SbkObjectType_GetReserved(Py_TYPE(self));
+        int flags = currentSelectId(Py_TYPE(self));
         int snake_flag = flags & 0x01;
         uint cnameLen = qstrlen(cname);
         if (std::strncmp("__", cname, 2)) {
diff --git a/sources/shiboken6/libshiboken/basewrapper.h b/sources/shiboken6/libshiboken/basewrapper.h
index 947bfdd1c..86806c917 100644
--- a/sources/shiboken6/libshiboken/basewrapper.h
+++ b/sources/shiboken6/libshiboken/basewrapper.h
@@ -61,10 +61,6 @@ typedef void (*SubTypeInitHook)(PyTypeObject *, PyObject *, PyObject *);
 typedef void (*SelectableFeatureHook)(PyTypeObject *);
 LIBSHIBOKEN_API SelectableFeatureHook initSelectableFeature(SelectableFeatureHook func);
 
-/// PYSIDE-1019: Get access to PySide reserved bits.
-LIBSHIBOKEN_API int SbkObjectType_GetReserved(PyTypeObject *type);
-LIBSHIBOKEN_API void SbkObjectType_SetReserved(PyTypeObject *type, int value);
-
 /// PYSIDE-1626: Enforcing a context switch without further action.
 LIBSHIBOKEN_API void SbkObjectType_UpdateFeature(PyTypeObject *type);
 
diff --git a/sources/shiboken6/libshiboken/basewrapper_p.h b/sources/shiboken6/libshiboken/basewrapper_p.h
index fcd22bf2d..fc3cc321c 100644
--- a/sources/shiboken6/libshiboken/basewrapper_p.h
+++ b/sources/shiboken6/libshiboken/basewrapper_p.h
@@ -97,15 +97,6 @@ struct SbkObjectTypePrivate
     TypeDiscoveryFuncV2 type_discovery;
     /// Pointer to a function responsible for deletion of the C++ instance calling the proper destructor.
     ObjectDestructor cpp_dtor;
-    /// PYSIDE-1019: Caching the current select Id
-    int pyside_reserved_bits;   // MSVC has bug with the sign bit, so use no bitfield.!
-    /// True if this type holds two or more C++ instances, e.g.: a Python class which inherits from two C++ classes.
-    unsigned int is_multicpp : 1;
-    /// True if this type was defined by the user.
-    unsigned int is_user_type : 1;
-    /// Tells is the type is a value type or an object-type, see BEHAVIOUR_ *constants.
-    unsigned int type_behaviour : 2;
-    unsigned int delete_in_main_thread : 1;
     /// C++ name
     char *original_name;
     /// Type user data
@@ -116,6 +107,14 @@ struct SbkObjectTypePrivate
     const char **enumFlagInfo;
     PyObject *enumFlagsDict;
     PyObject *enumTypeDict;
+
+    /// True if this type holds two or more C++ instances, e.g.: a Python class which inherits from two C++ classes.
+    unsigned int is_multicpp : 1;
+    /// True if this type was defined by the user.
+    unsigned int is_user_type : 1;
+    /// Tells is the type is a value type or an object-type, see BEHAVIOUR_ *constants.
+    unsigned int type_behaviour : 2;
+    unsigned int delete_in_main_thread : 1;
 };
 
 
diff --git a/sources/shiboken6/libshiboken/sbkfeature_base.cpp b/sources/shiboken6/libshiboken/sbkfeature_base.cpp
index 3b7439262..9e28d1239 100644
--- a/sources/shiboken6/libshiboken/sbkfeature_base.cpp
+++ b/sources/shiboken6/libshiboken/sbkfeature_base.cpp
@@ -56,9 +56,13 @@ PyObject *getFeatureSelectId()
 
 int currentSelectId(PyTypeObject *type)
 {
-    int sel = SbkObjectType_GetReserved(type);
-    // This could theoretically be -1 if used too early.
-    assert(sel >= 0);
+    PyObject *PyId = PyObject_GetAttr(type->tp_dict, PyName::select_id());
+    if (PyId == nullptr) {
+        PyErr_Clear();
+        return 0x00;
+    }
+    int sel = PyLong_AsLong(PyId);
+    Py_DECREF(PyId);
     return sel;
 }
 
@@ -366,17 +370,6 @@ int SbkObject_GenericSetAttr(PyObject *obj, PyObject *name, PyObject *value)
     return PyObject_GenericSetAttr(obj, name, value);
 }
 
-// Caching the select Id.
-int SbkObjectType_GetReserved(PyTypeObject *type)
-{
-    return PepType_SOTP(type)->pyside_reserved_bits;
-}
-
-void SbkObjectType_SetReserved(PyTypeObject *type, int value)
-{
-    PepType_SOTP(type)->pyside_reserved_bits = value;
-}
-
 const char **SbkObjectType_GetPropertyStrings(PyTypeObject *type)
 {
     return PepType_SOTP(type)->propertyStrings;
diff --git a/sources/shiboken6/libshiboken/signature/signature.cpp b/sources/shiboken6/libshiboken/signature/signature.cpp
index 808edc5cf..f83618779 100644
--- a/sources/shiboken6/libshiboken/signature/signature.cpp
+++ b/sources/shiboken6/libshiboken/signature/signature.cpp
@@ -21,6 +21,7 @@
 #include "sbkstring.h"
 #include "sbkstaticstrings.h"
 #include "sbkstaticstrings_p.h"
+#include "sbkfeature_base.h"
 
 #include <structmember.h>
 
@@ -534,7 +535,7 @@ static PyObject *adjustFuncName(const char *func_name)
     // Find the feature flags
     auto type = reinterpret_cast<PyTypeObject *>(obtype.object());
     auto dict = type->tp_dict;
-    int id = SbkObjectType_GetReserved(type);
+    int id = currentSelectId(type);
     id = id < 0 ? 0 : id;   // if undefined, set to zero
     auto lower = id & 0x01;
     auto is_prop = id & 0x02;