shiboken6: Handle pointers to containers

Opaque containers were disabled for functions taking a pointer to a
container since the number of indirections generated was incorrect.
Functions taking a pointer to a container where no opaque container
exists caused a crash since shiboken generated a value conversion to
an uninitialized pointer.

Change e4c2272dc60e1ff5e2d0933238fe4508af5f7f60 fixed the number of
indirections used for arguments.

With this, enable opaque containers also for functions taking a
pointer. Use the same code path also for the case of a function taking
a container by pointer since it provides a local variable to store the
value.

As a drive by, this also allows for a virtual function
reimplemented in Python to return an opaque container.

Change writePythonToCppTypeConversion() to return the
number of indirections in case of return types.

Remove flag CppGenerator::PythonToCppTypeConversionFlag.

[ChangeLog][shiboken6] Code generation for functions taking a
pointer to a container has been fixed.

Pick-to: 6.2
Task-number: PYSIDE-1605
Task-number: PYSIDE-1790
Change-Id: Ifa0bafb1316d7edfe1efc2183459b1ee6924f5a1
Reviewed-by: Shyamnath Premnadh <Shyamnath.Premnadh@qt.io>
Reviewed-by: Christian Tismer <tismer@stackless.com>

1 files changed, 35 insertions, 2 deletions

diff --git a/sources/shiboken6/tests/minimalbinding/listuser_test.py b/sources/shiboken6/tests/minimalbinding/listuser_test.py
index a1fc48c08..a31a5aab2 100644
--- a/sources/shiboken6/tests/minimalbinding/listuser_test.py
+++ b/sources/shiboken6/tests/minimalbinding/listuser_test.py
@@ -44,7 +44,10 @@ from minimal import ListUser, Val, Obj, StdIntList
 
 class ExtListUser(ListUser):
     def __init__(self):
-        ListUser.__init__(self)
+        super().__init__()
+        self._stdIntList = StdIntList()
+        self._stdIntList.append(1)
+        self._stdIntList.append(2)
 
     def createIntList(self, num):
         return list(range(0, num * 2, 2))
@@ -78,6 +81,9 @@ class ExtListUser(ListUser):
     def sumListOfIntLists(self, intListList):
         return sum([sum(line) for line in intListList]) * 2
 
+    def returnIntListByPtr(self):
+        return self._stdIntList
+
 
 class IntListConversionTest(unittest.TestCase):
 
@@ -356,7 +362,34 @@ class ListOfIntListConversionTest(unittest.TestCase):
         self.assertEqual(len(const_l), 4)
         self.assertRaises(TypeError, const_l.append, 6)
 
+    def testListByPtrOpaque(self):
+        """Test a function taking C++ list by pointer for which an opaque
+           container exists."""
+        lu = ListUser()
+        python_list = [1, 2]
+        self.assertEqual(lu.modifyIntListPtr(python_list), 2)
+
+        # Pass an opaque container and verify whether it is modified by C++
+        cpp_list = StdIntList()
+        cpp_list.append(1)
+        cpp_list.append(2)
+        self.assertEqual(lu.modifyIntListPtr(cpp_list), 2)
+        self.assertEqual(len(cpp_list), 3)
+
+    def testListByPtr(self):
+        """Test a function taking C++ list by pointer for which no opaque
+           container exists."""
+        lu = ListUser()
+        python_list = [1.1, 22.2]
+        self.assertEqual(lu.modifyDoubleListPtr(python_list), 2)
+
+    def testReturnListByPtr(self):
+        """Test that a virtual function returning a list by pointer can be
+           reimplemented by a Python function returning an opaque container."""
+        lu = ExtListUser()
+        size = lu.callReturnIntListByPtr()  # Call virtual from C++
+        self.assertEqual(size, 2)
+
 
 if __name__ == '__main__':
     unittest.main()
-