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+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt for Python.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "feature_select.h"
+#include "pyside.h"
+#include "pysidestaticstrings.h"
+#include "class_property.h"
+
+#include <shiboken.h>
+#include <sbkstaticstrings.h>
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// PYSIDE-1019: Support switchable extensions
+//
+// This functionality is no longer implemented in the signature module, since
+// the PyCFunction getsets do not have to be modified any longer.
+// Instead, we simply exchange the complete class dicts. This is done in the
+// basewrapper.cpp file and in every generated `tp_(get|set)attro`.
+//
+// This is the general framework of the switchable extensions.
+// A maximum of eight features is planned so far. This seems to be enough.
+// More features are possible, but then we must somehow register the
+// extra `select_id`s above 255.
+//
+
+/*****************************************************************************
+
+ How Does This Feature Selection Work?
+ -------------------------------------
+
+The basic idea is to replace the `tp_dict` of a QObject derived type.
+This way, we can replace the methods of the class in no time.
+
+The crucial point to understand is how the `tp_dict` is actually accessed:
+When you type "QObject.__dict__", the descriptor of `SbkObjectType_Type`
+is called. This descriptor is per default unassigned, so the base class
+PyType_Type provides the tp_getset method `type_dict`:
+
+ static PyObject *
+ type_dict(PyTypeObject *type, void *context)
+ {
+ if (type->tp_dict == NULL) {
+ Py_RETURN_NONE;
+ }
+ return PyDictProxy_New(type->tp_dict);
+ }
+
+In order to change that, we need to insert our own version into SbkObjectType:
+
+ static PyObject *Sbk_TypeGet___dict__(PyTypeObject *type, void *context)
+ {
+ auto dict = type->tp_dict;
+ if (dict == NULL)
+ Py_RETURN_NONE;
+ if (SelectFeatureSet != nullptr)
+ dict = SelectFeatureSet(type);
+ return PyDictProxy_New(dict);
+ }
+
+This way, the Python function `type_ready()` does not fill in the default,
+but uses our modified version. It a similar way, we overwrite type_getattro
+with our own version, again in SbkObjectType, replacing the default of
+PyType_Type.
+
+Now we can exchange the dict with a customized version.
+We have our own derived type `ChameleonDict` with additional attributes.
+These allow us to create a ring of dicts which can be rotated to the actual
+needed dict version:
+
+Every dict has a field `select_id` which is selected by the `from __feature__`
+import. The dicts are cyclic connected by the `dict_ring` field.
+
+When a class dict is required, now always `SelectFeatureSet` is called, which
+looks into the `__name__` attribute of the active module and decides which
+version of `tp_dict` is needed. Then the right dict is searched in the ring
+and created if not already there.
+
+Furthermore, we need to overwrite every `tp_(get|set)attro` with a version
+that switches dicts right before looking up methods.
+The dict changing must walk the whole `tp_mro` in order to change all names.
+
+This is everything that the following code does.
+
+*****************************************************************************/
+
+
+namespace PySide { namespace Feature {
+
+using namespace Shiboken;
+
+typedef bool(*FeatureProc)(PyTypeObject *type, PyObject *prev_dict, int id);
+
+static FeatureProc *featurePointer = nullptr;
+
+static PyObject *cached_globals = nullptr;
+static PyObject *last_select_id = nullptr;
+
+static PyObject *_fast_id_array[1 + 256] = {};
+// this will point to element 1 to allow indexing from -1
+static PyObject **fast_id_array;
+
+static inline PyObject *getFeatureSelectId()
+{
+ static PyObject *undef = fast_id_array[-1];
+ static PyObject *feature_dict = GetFeatureDict();
+ // these things are all borrowed
+ PyObject *globals = PyEval_GetGlobals();
+ if ( globals == nullptr
+ || globals == cached_globals)
+ return last_select_id;
+
+ PyObject *modname = PyDict_GetItem(globals, PyMagicName::name());
+ if (modname == nullptr)
+ return last_select_id;
+
+ PyObject *select_id = PyDict_GetItem(feature_dict, modname);
+ if ( select_id == nullptr
+ || !PyInt_Check(select_id) // int/long cheating
+ || select_id == undef)
+ return last_select_id;
+
+ cached_globals = globals;
+ last_select_id = select_id;
+ assert(PyInt_AsSsize_t(select_id) >= 0);
+ return select_id;
+}
+
+// Create a derived dict class
+static PyTypeObject *
+createDerivedDictType()
+{
+ // It is not easy to create a compatible dict object with the
+ // limited API. Easier is to use Python to create a derived
+ // type and to modify that a bit from the C code.
+ PyObject *ChameleonDict = PepRun_GetResult(R"CPP(if True:
+
+ class ChameleonDict(dict):
+ __slots__ = ("dict_ring", "select_id")
+
+ result = ChameleonDict
+
+ )CPP");
+ return reinterpret_cast<PyTypeObject *>(ChameleonDict);
+}
+
+static PyTypeObject *new_dict_type = nullptr;
+
+static void ensureNewDictType()
+{
+ if (new_dict_type == nullptr) {
+ new_dict_type = createDerivedDictType();
+ if (new_dict_type == nullptr)
+ Py_FatalError("PySide6: Problem creating ChameleonDict");
+ }
+}
+
+static inline PyObject *nextInCircle(PyObject *dict)
+{
+ // returns a borrowed ref
+ AutoDecRef next_dict(PyObject_GetAttr(dict, PyName::dict_ring()));
+ return next_dict;
+}
+
+static inline void setNextDict(PyObject *dict, PyObject *next_dict)
+{
+ PyObject_SetAttr(dict, PyName::dict_ring(), next_dict);
+}
+
+static inline void setSelectId(PyObject *dict, PyObject *select_id)
+{
+ PyObject_SetAttr(dict, PyName::select_id(), select_id);
+}
+
+static inline PyObject *getSelectId(PyObject *dict)
+{
+ auto select_id = PyObject_GetAttr(dict, PyName::select_id());
+ return select_id;
+}
+
+static inline void setCurrentSelectId(PyTypeObject *type, PyObject *select_id)
+{
+ SbkObjectType_SetReserved(type, PyInt_AsSsize_t(select_id)); // int/long cheating
+}
+
+static inline void setCurrentSelectId(PyTypeObject *type, int id)
+{
+ SbkObjectType_SetReserved(type, id);
+}
+
+static inline PyObject *getCurrentSelectId(PyTypeObject *type)
+{
+ int id = SbkObjectType_GetReserved(type);
+ // This can be too early.
+ if (id < 0)
+ id = 0;
+ return fast_id_array[id];
+}
+
+static bool replaceClassDict(PyTypeObject *type)
+{
+ /*
+ * Replace the type dict by the derived ChameleonDict.
+ * This is mandatory for all type dicts when they are touched.
+ */
+ ensureNewDictType();
+ PyObject *dict = type->tp_dict;
+ auto ob_ndt = reinterpret_cast<PyObject *>(new_dict_type);
+ PyObject *new_dict = PyObject_CallObject(ob_ndt, nullptr);
+ if (new_dict == nullptr || PyDict_Update(new_dict, dict) < 0)
+ return false;
+ // Insert the default id. Cannot fail for small numbers.
+ AutoDecRef select_id(PyInt_FromLong(0));
+ setSelectId(new_dict, select_id);
+ // insert the dict into itself as ring
+ setNextDict(new_dict, new_dict);
+ // We have now an exact copy of the dict with a new type.
+ // Replace `__dict__` which usually has refcount 1 (but see cyclic_test.py)
+ Py_DECREF(type->tp_dict);
+ type->tp_dict = new_dict;
+ return true;
+}
+
+static bool addNewDict(PyTypeObject *type, PyObject *select_id)
+{
+ /*
+ * Add a new dict to the ring and set it as `type->tp_dict`.
+ * A 'false' return is fatal.
+ */
+ auto dict = type->tp_dict;
+ auto ob_ndt = reinterpret_cast<PyObject *>(new_dict_type);
+ auto new_dict = PyObject_CallObject(ob_ndt, nullptr);
+ if (new_dict == nullptr)
+ return false;
+ setSelectId(new_dict, select_id);
+ // insert the dict into the ring
+ auto next_dict = nextInCircle(dict);
+ setNextDict(dict, new_dict);
+ setNextDict(new_dict, next_dict);
+ type->tp_dict = new_dict;
+ return true;
+}
+
+static bool moveToFeatureSet(PyTypeObject *type, PyObject *select_id)
+{
+ /*
+ * Rotate the ring to the given `select_id` and return `true`.
+ * If not found, stay at the current position and return `false`.
+ */
+ auto initial_dict = type->tp_dict;
+ auto dict = initial_dict;
+ do {
+ dict = nextInCircle(dict);
+ AutoDecRef current_id(getSelectId(dict));
+ // This works because small numbers are singleton objects.
+ if (current_id == select_id) {
+ type->tp_dict = dict;
+ setCurrentSelectId(type, select_id);
+ return true;
+ }
+ } while (dict != initial_dict);
+ type->tp_dict = initial_dict;
+ return false;
+}
+
+static bool createNewFeatureSet(PyTypeObject *type, PyObject *select_id)
+{
+ /*
+ * Create a new feature set.
+ * A `false` return value is a fatal error.
+ *
+ * A FeatureProc sees an empty `type->tp_dict` and the previous dict
+ * content in `prev_dict`. It is responsible of filling `type->tp_dict`
+ * with modified content.
+ */
+ static auto small_1 = PyInt_FromLong(255);
+ Q_UNUSED(small_1);
+ static auto small_2 = PyInt_FromLong(255);
+ Q_UNUSED(small_2);
+ // make sure that small integers are cached
+ assert(small_1 != nullptr && small_1 == small_2);
+
+ static auto zero = fast_id_array[0];
+ bool ok = moveToFeatureSet(type, zero);
+ Q_UNUSED(ok);
+ assert(ok);
+
+ AutoDecRef prev_dict(type->tp_dict);
+ Py_INCREF(prev_dict); // keep the first ref unchanged
+ if (!addNewDict(type, select_id))
+ return false;
+ auto id = PyInt_AsSsize_t(select_id); // int/long cheating
+ if (id == -1)
+ return false;
+ setCurrentSelectId(type, id);
+ FeatureProc *proc = featurePointer;
+ for (int idx = id; *proc != nullptr; ++proc, idx >>= 1) {
+ if (idx & 1) {
+ // clear the tp_dict that will get new content
+ PyDict_Clear(type->tp_dict);
+ // let the proc re-fill the tp_dict
+ if (!(*proc)(type, prev_dict, id))
+ return false;
+ // if there is still a step, prepare `prev_dict`
+ if (idx >> 1) {
+ prev_dict.reset(PyDict_Copy(type->tp_dict));
+ if (prev_dict.isNull())
+ return false;
+ }
+ }
+ }
+ return true;
+}
+
+static bool SelectFeatureSetSubtype(PyTypeObject *type, PyObject *select_id)
+{
+ /*
+ * This is the selector for one sublass. We need to call this for
+ * every subclass until no more subclasses or reaching the wanted id.
+ */
+ if (Py_TYPE(type->tp_dict) == Py_TYPE(PyType_Type.tp_dict)) {
+ // On first touch, we initialize the dynamic naming.
+ // The dict type will be replaced after the first call.
+ if (!replaceClassDict(type)) {
+ Py_FatalError("failed to replace class dict!");
+ return false;
+ }
+ }
+ if (!moveToFeatureSet(type, select_id)) {
+ if (!createNewFeatureSet(type, select_id)) {
+ Py_FatalError("failed to create a new feature set!");
+ return false;
+ }
+ }
+ return true;
+}
+
+static inline PyObject *SelectFeatureSet(PyTypeObject *type)
+{
+ /*
+ * This is the main function of the module.
+ * The purpose of this function is to switch the dict of a class right
+ * before a (get|set)attro call is performed.
+ *
+ * Generated functions call this directly.
+ * Shiboken will assign it via a public hook of `basewrapper.cpp`.
+ */
+ if (Py_TYPE(type->tp_dict) == Py_TYPE(PyType_Type.tp_dict)) {
+ // We initialize the dynamic features by using our own dict type.
+ if (!replaceClassDict(type))
+ return nullptr;
+ }
+ PyObject *select_id = getFeatureSelectId(); // borrowed
+ PyObject *current_id = getCurrentSelectId(type); // borrowed
+ static PyObject *undef = fast_id_array[-1];
+
+ // PYSIDE-1019: During import PepType_SOTP is still zero.
+ if (current_id == undef)
+ current_id = select_id = fast_id_array[0];
+
+ if (select_id != current_id) {
+ PyObject *mro = type->tp_mro;
+ Py_ssize_t idx, n = PyTuple_GET_SIZE(mro);
+ // We leave 'Shiboken.Object' and 'object' alone, therefore "n - 2".
+ for (idx = 0; idx < n - 2; idx++) {
+ auto *sub_type = reinterpret_cast<PyTypeObject *>(PyTuple_GET_ITEM(mro, idx));
+ // When any subtype is already resolved (false), we can stop.
+ if (!SelectFeatureSetSubtype(sub_type, select_id))
+ break;
+ }
+ }
+ return type->tp_dict;
+}
+
+// For cppgenerator:
+void Select(PyObject *obj)
+{
+ if (featurePointer == nullptr)
+ return;
+ auto type = Py_TYPE(obj);
+ type->tp_dict = SelectFeatureSet(type);
+}
+
+PyObject *Select(PyTypeObject *type)
+{
+ if (featurePointer != nullptr)
+ type->tp_dict = SelectFeatureSet(type);
+ return type->tp_dict;
+}
+
+static bool feature_01_addLowerNames(PyTypeObject *type, PyObject *prev_dict, int id);
+static bool feature_02_true_property(PyTypeObject *type, PyObject *prev_dict, int id);
+static bool feature_04_addDummyNames(PyTypeObject *type, PyObject *prev_dict, int id);
+static bool feature_08_addDummyNames(PyTypeObject *type, PyObject *prev_dict, int id);
+static bool feature_10_addDummyNames(PyTypeObject *type, PyObject *prev_dict, int id);
+static bool feature_20_addDummyNames(PyTypeObject *type, PyObject *prev_dict, int id);
+static bool feature_40_addDummyNames(PyTypeObject *type, PyObject *prev_dict, int id);
+static bool feature_80_addDummyNames(PyTypeObject *type, PyObject *prev_dict, int id);
+
+static FeatureProc featureProcArray[] = {
+ feature_01_addLowerNames,
+ feature_02_true_property,
+ feature_04_addDummyNames,
+ feature_08_addDummyNames,
+ feature_10_addDummyNames,
+ feature_20_addDummyNames,
+ feature_40_addDummyNames,
+ feature_80_addDummyNames,
+ nullptr
+};
+
+void finalize()
+{
+ for (int idx = -1; idx < 256; ++idx)
+ Py_DECREF(fast_id_array[idx]);
+}
+
+static bool patch_property_impl();
+
+void init()
+{
+ // This function can be called multiple times.
+ static bool is_initialized = false;
+ if (!is_initialized) {
+ fast_id_array = &_fast_id_array[1];
+ for (int idx = -1; idx < 256; ++idx)
+ fast_id_array[idx] = PyInt_FromLong(idx);
+ last_select_id = fast_id_array[0];
+ featurePointer = featureProcArray;
+ initSelectableFeature(SelectFeatureSet);
+ registerCleanupFunction(finalize);
+ patch_property_impl();
+ PySide::ClassProperty::init();
+ is_initialized = true;
+ }
+ // Reset the cache. This is called at any "from __feature__ import".
+ cached_globals = nullptr;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// PYSIDE-1019: Support switchable extensions
+//
+// Feature 0x01: Allow snake_case instead of camelCase
+//
+// This functionality is no longer implemented in the signature module, since
+// the PyCFunction getsets do not have to be modified any longer.
+// Instead, we simply exchange the complete class dicts. This is done in the
+// basewrapper.cpp file.
+//
+
+static PyObject *methodWithNewName(PyTypeObject *type,
+ PyMethodDef *meth,
+ const char *new_name)
+{
+ /*
+ * Create a method with a lower case name.
+ */
+ auto obtype = reinterpret_cast<PyObject *>(type);
+ int len = strlen(new_name);
+ auto name = new char[len + 1];
+ strcpy(name, new_name);
+ auto new_meth = new PyMethodDef;
+ new_meth->ml_name = name;
+ new_meth->ml_meth = meth->ml_meth;
+ new_meth->ml_flags = meth->ml_flags;
+ new_meth->ml_doc = meth->ml_doc;
+ PyObject *descr = nullptr;
+ if (new_meth->ml_flags & METH_STATIC) {
+ AutoDecRef cfunc(PyCFunction_NewEx(new_meth, obtype, nullptr));
+ if (cfunc.isNull())
+ return nullptr;
+ descr = PyStaticMethod_New(cfunc);
+ }
+ else {
+ descr = PyDescr_NewMethod(type, new_meth);
+ }
+ return descr;
+}
+
+static bool feature_01_addLowerNames(PyTypeObject *type, PyObject *prev_dict, int id)
+{
+ /*
+ * Add objects with lower names to `type->tp_dict` from 'prev_dict`.
+ */
+ PyObject *lower_dict = type->tp_dict;
+ PyObject *key, *value;
+ Py_ssize_t pos = 0;
+
+ // We first copy the things over which will not be changed:
+ while (PyDict_Next(prev_dict, &pos, &key, &value)) {
+ if ( Py_TYPE(value) != PepMethodDescr_TypePtr
+ && Py_TYPE(value) != PepStaticMethod_TypePtr) {
+ if (PyDict_SetItem(lower_dict, key, value))
+ return false;
+ continue;
+ }
+ }
+ // Then we walk over the tp_methods to get all methods and insert
+ // them with changed names.
+ PyMethodDef *meth = type->tp_methods;
+ if (!meth)
+ return true;
+
+ for (; meth != nullptr && meth->ml_name != nullptr; ++meth) {
+ const char *name = String::toCString(String::getSnakeCaseName(meth->ml_name, true));
+ AutoDecRef new_method(methodWithNewName(type, meth, name));
+ if (new_method.isNull())
+ return false;
+ if (PyDict_SetItemString(lower_dict, name, new_method) < 0)
+ return false;
+ }
+ return true;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// PYSIDE-1019: Support switchable extensions
+//
+// Feature 0x02: Use true properties instead of getters and setters
+//
+
+// This is the Python 2 version for inspection of m_ml, only.
+// The actual Python 3 version is larget.
+
+typedef struct {
+ PyObject_HEAD
+ PyMethodDef *m_ml; /* Description of the C function to call */
+ PyObject *m_self; /* Passed as 'self' arg to the C func, can be NULL */
+ PyObject *m_module; /* The __module__ attribute, can be anything */
+} PyCFunctionObject;
+
+static PyObject *modifyStaticToClassMethod(PyTypeObject *type, PyObject *sm)
+{
+ AutoDecRef func_ob(PyObject_GetAttr(sm, PyMagicName::func()));
+ if (func_ob.isNull())
+ return nullptr;
+ auto func = reinterpret_cast<PyCFunctionObject *>(func_ob.object());
+ auto new_func = new PyMethodDef;
+ new_func->ml_name = func->m_ml->ml_name;
+ new_func->ml_meth = func->m_ml->ml_meth;
+ new_func->ml_flags = (func->m_ml->ml_flags & ~METH_STATIC) | METH_CLASS;
+ new_func->ml_doc = func->m_ml->ml_doc;
+ auto cfunc = PyCFunction_NewEx(new_func, nullptr, nullptr);
+ cfunc = PyDescr_NewClassMethod(type, new_func);
+ return cfunc;
+}
+
+static PyObject *createProperty(PyTypeObject *type, PyObject *getter, PyObject *setter)
+{
+ bool chassprop = false;
+ assert(getter != nullptr);
+ if (setter == nullptr)
+ setter = Py_None;
+ auto ptype = &PyProperty_Type;
+ if (Py_TYPE(getter) == PepStaticMethod_TypePtr) {
+ ptype = PyClassPropertyTypeF();
+ chassprop = true;
+ getter = modifyStaticToClassMethod(type, getter);
+ if (setter != Py_None)
+ setter = modifyStaticToClassMethod(type, setter);
+ }
+ auto obtype = reinterpret_cast<PyObject *>(ptype);
+ PyObject *prop = PyObject_CallFunctionObjArgs(obtype, getter, setter, nullptr);
+ return prop;
+}
+
+static QStringList parseFields(const char *propstr)
+{
+ /*
+ * Break the string into subfields at ':' and add defaults.
+ */
+ QString s = QString(QLatin1String(propstr));
+ auto list = s.split(QLatin1Char(':'));
+ assert(list.size() == 2 || list.size() == 3);
+ auto name = list[0];
+ auto read = list[1];
+ if (read.size() == 0)
+ list[1] = name;
+ if (list.size() == 2)
+ return list;
+ auto write = list[2];
+ if (write.size() == 0) {
+ list[2] = QLatin1String("set") + name;
+ list[2][3] = list[2][3].toUpper();
+ }
+ return list;
+}
+
+static PyObject *make_snake_case(QString s, bool lower)
+{
+ if (s.isNull())
+ return nullptr;
+ return String::getSnakeCaseName(s.toLatin1().data(), lower);
+}
+
+static bool feature_02_true_property(PyTypeObject *type, PyObject *prev_dict, int id)
+{
+ /*
+ * Use the property info to create true Python property objects.
+ */
+
+ // The empty `tp_dict` gets populated by the previous dict.
+ PyObject *prop_dict = type->tp_dict;
+ if (PyDict_Update(prop_dict, prev_dict) < 0)
+ return false;
+
+ // We then replace methods by properties.
+ bool lower = (id & 0x01) != 0;
+ auto props = SbkObjectType_GetPropertyStrings(type);
+ if (props == nullptr || *props == nullptr)
+ return true;
+ for (; *props != nullptr; ++props) {
+ auto propstr = *props;
+ auto fields = parseFields(propstr);
+ bool haveWrite = fields.size() == 3;
+ PyObject *name = make_snake_case(fields[0], lower);
+ PyObject *read = make_snake_case(fields[1], lower);
+ PyObject *write = haveWrite ? make_snake_case(fields[2], lower) : nullptr;
+ PyObject *getter = PyDict_GetItem(prev_dict, read);
+ if (getter == nullptr || !(Py_TYPE(getter) == PepMethodDescr_TypePtr ||
+ Py_TYPE(getter) == PepStaticMethod_TypePtr))
+ continue;
+ PyObject *setter = haveWrite ? PyDict_GetItem(prev_dict, write) : nullptr;
+
+ AutoDecRef PyProperty(createProperty(type, getter, setter));
+ if (PyProperty.isNull())
+ return false;
+ if (PyDict_SetItem(prop_dict, name, PyProperty) < 0)
+ return false;
+ if (fields[0] != fields[1] && PyDict_GetItem(prop_dict, read))
+ if (PyDict_DelItem(prop_dict, read) < 0)
+ return false;
+ // Theoretically, we need to check for multiple signatures to be exact.
+ // But we don't do so intentionally because it would be confusing.
+ if (haveWrite && PyDict_GetItem(prop_dict, write))
+ if (PyDict_DelItem(prop_dict, write) < 0)
+ return false;
+ }
+ return true;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// These are a number of patches to make Python's property object better
+// suitable for us.
+// We turn `__doc__` into a lazy attribute saving signature initialization.
+//
+// There is now also a class property implementation which inherits
+// from this one.
+//
+
+static PyObject *property_doc_get(PyObject *self, void *)
+{
+ auto po = reinterpret_cast<propertyobject *>(self);
+
+ if (po->prop_doc != nullptr && po->prop_doc != Py_None) {
+ Py_INCREF(po->prop_doc);
+ return po->prop_doc;
+ }
+ if (po->prop_get) {
+ // PYSIDE-1019: Fetch the default `__doc__` from fget. We do it late.
+ auto txt = PyObject_GetAttr(po->prop_get, PyMagicName::doc());
+ if (txt != nullptr) {
+ Py_INCREF(txt);
+ po->prop_doc = txt;
+ Py_INCREF(txt);
+ return txt;
+ }
+ PyErr_Clear();
+ }
+ Py_RETURN_NONE;
+}
+
+static int property_doc_set(PyObject *self, PyObject *value, void *)
+{
+ auto po = reinterpret_cast<propertyobject *>(self);
+
+ Py_INCREF(value);
+ po->prop_doc = value;
+ return 0;
+}
+
+static PyGetSetDef property_getset[] = {
+ // This gets added to the existing getsets
+ {const_cast<char *>("__doc__"), property_doc_get, property_doc_set, nullptr, nullptr},
+ {nullptr, nullptr, nullptr, nullptr, nullptr}
+};
+
+static bool patch_property_impl()
+{
+ // Turn `__doc__` into a computed attribute without changing writability.
+ auto gsp = property_getset;
+ auto type = &PyProperty_Type;
+ auto dict = type->tp_dict;
+ AutoDecRef descr(PyDescr_NewGetSet(type, gsp));
+ if (descr.isNull())
+ return false;
+ if (PyDict_SetItemString(dict, gsp->name, descr) < 0)
+ return false;
+ return true;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// PYSIDE-1019: Support switchable extensions
+//
+// Feature 0x04..0x40: A fake switchable option for testing
+//
+
+#define SIMILAR_FEATURE(xx) \
+static bool feature_##xx##_addDummyNames(PyTypeObject *type, PyObject *prev_dict, int id) \
+{ \
+ PyObject *dict = type->tp_dict; \
+ if (PyDict_Update(dict, prev_dict) < 0) \
+ return false; \
+ if (PyDict_SetItemString(dict, "fake_feature_" #xx, Py_None) < 0) \
+ return false; \
+ return true; \
+}
+
+SIMILAR_FEATURE(04)
+SIMILAR_FEATURE(08)
+SIMILAR_FEATURE(10)
+SIMILAR_FEATURE(20)
+SIMILAR_FEATURE(40)
+SIMILAR_FEATURE(80)
+
+} // namespace PySide
+} // namespace Feature