Support a Python 3.10 build in 5.15 without limited API

The original patch worked with limited API, only.

This one adds the missing _Py_Mangle function as in
PySide 6.X and modernizes and fixes the modern embedding
support.

A remaining problem is building with debug Python 3.10 .
There are many refcount errors which need to be found
again, because they all were solved in PySide 6.X .

With the same limited quality of the solution for 5.15 and
the limited API, this is a fix, the debug problem comes later.

Task-number: PYSIDE-1749
Fixes: PYSIDE-1775
Change-Id: I18a9b6756e49850c5d2d2e65b65e1ae934154905
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

2 files changed, 24 insertions, 22 deletions

diff --git a/sources/shiboken2/libshiboken/embed/signature_bootstrap.py b/sources/shiboken2/libshiboken/embed/signature_bootstrap.py
index b461ea229..508dd3fae 100644
--- a/sources/shiboken2/libshiboken/embed/signature_bootstrap.py
+++ b/sources/shiboken2/libshiboken/embed/signature_bootstrap.py
@@ -44,6 +44,11 @@ recursion_trap = 0
 # Python 2 is not able to import when the extension import is still active.
 # Phase 1 simply defines the functions, which will be used in Phase 2.
 
+import sys
+if sys.version_info[0] >= 3:
+    from importlib.machinery import ModuleSpec
+
+
 def bootstrap():
     import sys
     import os
@@ -186,31 +191,28 @@ class EmbeddableZipImporter(object):
             return None
 
         self.zfile = zip_file
-        self._path2mod = {_.filename : p2m(_.filename) for _ in zip_file.filelist}
-        self._mod2path = {_[1] : _[0] for _ in self._path2mod.items()}
+        self._mod2path = {p2m(_.filename) : _.filename for _ in zip_file.filelist}
 
-    def find_module(self, fullname, path):
-        return self if self._mod2path.get(fullname) else None
+    def find_spec(self, fullname, path, target=None):
+        path = self._mod2path.get(fullname)
+        return ModuleSpec(fullname, self) if path else None
 
-    def load_module(self, fullname):
-        import importlib
-        import sys
+    def create_module(self, spec):
+        return None
 
-        filename = self._mod2path.get(fullname)
-        if filename not in self._path2mod:
-            raise ImportError(fullname)
-        module_spec = importlib.machinery.ModuleSpec(fullname, None)
-        new_module = importlib.util.module_from_spec(module_spec)
+    def exec_module(self, module):
+        fullname = module.__spec__.name
+        filename = self._mod2path[fullname]
         with self.zfile.open(filename, "r") as f:   # "rb" not for zipfile
-            exec(f.read(), new_module.__dict__)
-        new_module.__file__ = filename
-        new_module.__loader__ = self
+            codeob = compile(f.read(), filename, "exec")
+            exec(codeob, module.__dict__)
+        module.__file__ = filename
+        module.__loader__ = self
         if filename.endswith("/__init__.py"):
-            new_module.__path__ = []
-            new_module.__package__ = fullname
+            module.__path__ = []
+            module.__package__ = fullname
         else:
-            new_module.__package__ = fullname.rpartition('.')[0]
-        sys.modules[fullname] = new_module
-        return new_module
+            module.__package__ = fullname.rpartition('.')[0]
+        sys.modules[fullname] = module
 
 # eof
diff --git a/sources/shiboken2/libshiboken/pep384impl.cpp b/sources/shiboken2/libshiboken/pep384impl.cpp
index 629d5d84c..5b95b35ac 100644
--- a/sources/shiboken2/libshiboken/pep384impl.cpp
+++ b/sources/shiboken2/libshiboken/pep384impl.cpp
@@ -733,7 +733,7 @@ _Pep_PrivateMangle(PyObject *self, PyObject *name)
 #endif // IS_PY2
     Shiboken::AutoDecRef privateobj(PyObject_GetAttr(
         reinterpret_cast<PyObject *>(Py_TYPE(self)), Shiboken::PyMagicName::name()));
-#ifndef Py_LIMITED_API
+#ifdef IS_PY2
     return _Py_Mangle(privateobj, name);
 #else
     // PYSIDE-1436: _Py_Mangle is no longer exposed; implement it always.
@@ -771,7 +771,7 @@ _Pep_PrivateMangle(PyObject *self, PyObject *name)
     if (amount > big_stack)
         free(resbuf);
     return result;
-#endif // else Py_LIMITED_API
+#endif // else IS_PY2
 }
 
 /*****************************************************************************