PyPySide: Avoid direct access to `op->ob_dict` in PyPy

PyPy treats `op->ob_dict` specially. When you use PyObject_SetAttr
and look later for the attribute in the object's dict, you cannot
find it. PySide uses direct access to `ob_dict` which has this side
effect and was a major obstacle until the PyPy people explained the
undocumented behavior.

We either need to use a different attribute name than "ob_dict", or use
the C API for dict access. The second, simpler solution turned out to be
sufficient. Since the used function is in the Stable ABI in version
Python 3.10 only, we implemented a replacement function in basewrapper.

This change was crucial and led to the first public version.

[ChangeLog][shiboken6] PyPySide: Direct access to `op->ob_dict` needed
to be avoided in PyPy. This important change took the project far
enough to publish it as a preview and to produce wheels.

Task-number: PYSIDE-535
Change-Id: I09c59e7ebf78837868912cfd19330256eea71237
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

1 files changed, 4 insertions, 8 deletions

diff --git a/sources/shiboken6/generator/shiboken/cppgenerator.cpp b/sources/shiboken6/generator/shiboken/cppgenerator.cpp
index eb48b1b10..f5d677bc6 100644
--- a/sources/shiboken6/generator/shiboken/cppgenerator.cpp
+++ b/sources/shiboken6/generator/shiboken/cppgenerator.cpp
@@ -6103,16 +6103,12 @@ void CppGenerator::writeGetattroFunction(TextStream &s, AttroCheck attroCheck,
 
     if (attroCheck.testFlag(AttroCheckFlag::GetattroOverloads)) {
         s << "// Search the method in the instance dict\n"
-            << "if (auto ob_dict = reinterpret_cast<SbkObject *>(self)->ob_dict) {\n";
+            << "auto ob_dict = SbkObject_GetDict(self);\n";
+        s << "if (auto meth = PyDict_GetItem(ob_dict, name)) {\n";
         {
             Indentation indent(s);
-            s << "if (auto meth = PyDict_GetItem(ob_dict, name)) {\n";
-            {
-                Indentation indent(s);
-                s << "Py_INCREF(meth);\n"
-                    << "return meth;\n";
-            }
-            s << "}\n";
+            s << "Py_INCREF(meth);\n"
+                << "return meth;\n";
         }
         s << "}\n"
             << "// Search the method in the type dict\n"