Support wrapping cypclass with multiple bases

Cython/Compiler/CypclassWrapper.py

@@ -154,10 +154,7 @@ class CypclassWrapperInjection(VisitorTransform):
 
         if not node_has_suite:
             return None
-        
-        if len(node.base_classes) > 1:
-            return None
-        
+
         # TODO: take nesting into account for the name
         cclass_name = EncodedString("%s_cyp_wrapper" % node.name)
 
@@ -217,13 +214,12 @@ class CypclassWrapperInjection(VisitorTransform):
         return wrapper
 
     def synthesize_underlying_cyobject_attribute(self, node):
-        nested_names = [node.name for node in self.nesting_stack]
 
-        underlying_base_type = Nodes.CSimpleBaseTypeNode(
+        void_type_node = Nodes.CSimpleBaseTypeNode(
             node.pos,
-            name = node.name,
-            module_path = nested_names,
-            is_basic_c_type = 0,
+            name = "void",
+            module_path = [],
+            is_basic_c_type = 1,
             signed = 1,
             complex = 0,
             longness = 0,
@@ -232,11 +228,12 @@ class CypclassWrapperInjection(VisitorTransform):
         )
 
         underlying_name_declarator = Nodes.CNameDeclaratorNode(node.pos, name=underlying_name, cname=None)
+        underlying_name_declarator = Nodes.CPtrDeclaratorNode(node.pos, base=underlying_name_declarator)
 
         underlying_cyobject = Nodes.CVarDefNode(
             pos = node.pos,
             visibility = 'private',
-            base_type = underlying_base_type,
+            base_type = void_type_node,
             declarators = [underlying_name_declarator],
             in_pxd = node.in_pxd,
             doc = None,

Cython/Compiler/ModuleNode.py

@@ -1553,10 +1553,16 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
             "static void %s(PyObject *o) {" % slot_func_cname)
 
         # for cyp wrappers, just decrement the atomic counter of the underlying type
-        is_cyp_wrapper = scope.parent_type.is_cyp_wrapper
-        if is_cyp_wrapper:
+        parent_type = scope.parent_type
+        if parent_type.is_cyp_wrapper:
+            underlying_type_decl = parent_type.wrapped_decl
+            underlying_attribute_name = CypclassWrapper.underlying_name
             self.generate_self_cast(scope, code)
-            code.putln("Cy_DECREF(p->%s);" % CypclassWrapper.underlying_name)
+            code.putln(
+                "%s * p_nogil_cyobject = (%s *) (p->%s);"
+                % (underlying_type_decl, underlying_type_decl, underlying_attribute_name)
+            )
+            code.putln("Cy_DECREF(p_nogil_cyobject);")
             code.putln("}")
             return
 

Cython/Compiler/Nodes.py

@@ -5359,6 +5359,8 @@ class CypclassWrapperDefNode(CClassDefNode):
         self.entry.type.is_cyp_wrapper = 1
         # > associate the wrapper type to the wrapped type
         self.wrapped_cypclass.entry.type.wrapper_type = self.entry.type
+        # > remember the cname of the wrapped type
+        self.entry.type.wrapped_decl = self.wrapped_cypclass.entry.type.empty_declaration_code()
         # > insert and analyse each method wrapper
         self.insert_cypclass_method_wrappers(env)
     
@@ -5439,16 +5441,20 @@ class CypclassWrapperDefNode(CClassDefNode):
         # > reference to the self argument of the wrapper method
         self_obj = ExprNodes.NameNode(self_pos, name=self_name)
 
-        # > access the method of the underlying cyobject from the self argument of the wrapper method
+        # > access the underlying cyobject from the self argument of the wrapper method
         underlying_obj = ExprNodes.AttributeNode(cfunc_method.pos, obj=self_obj, attribute=underlying_name)
         empty_declarator = CNameDeclaratorNode(cfunc_method.pos, name="", cname=None)
-        cast_underlying_obj = ExprNodes.TypecastNode(
+        cast_operation = ExprNodes.TypecastNode(
             cfunc_method.pos,
             type = self.wrapped_cypclass.entry.type,
             operand = underlying_obj,
             typecheck = False
         )
 
+        cast_underlying_obj = ExprNodes.NameNode(self_pos, name=EncodedString("cast_cyobject"))
+        cast_assignment = SingleAssignmentNode(self_pos, lhs=cast_underlying_obj, rhs=cast_operation)
+
+        # > access the method of the underlying object
         cfunc = ExprNodes.AttributeNode(cfunc_method.pos, obj=cast_underlying_obj, attribute=cfunc_name)
 
         # > call to the underlying method
@@ -5463,7 +5469,7 @@ class CypclassWrapperDefNode(CClassDefNode):
             py_stat = ExprStatNode(cfunc_method.pos, expr=c_call)
         else:
             py_stat = ReturnStatNode(cfunc_method.pos, return_type=PyrexTypes.py_object_type, value=c_call)
-        py_body = StatListNode(cfunc_method.pos, stats=[py_stat])
+        py_body = StatListNode(cfunc_method.pos, stats=[cast_assignment, py_stat])
 
         # > lock around the call in checklock mode
         if self.wrapped_cypclass.lock_mode == 'checklock':
@@ -5471,7 +5477,7 @@ class CypclassWrapperDefNode(CClassDefNode):
             lock_node = LockCypclassNode(
                 cfunc_method.pos,
                 state = 'wlocked' if need_wlock else 'rlocked',
-                obj = underlying_obj,
+                obj = cast_underlying_obj,
                 body = py_body
             )
             py_body = lock_node

Cython/Compiler/PyrexTypes.py

@@ -1362,11 +1362,13 @@ class PyExtensionType(PyObjectType):
     #  defered_declarations [thunk]      Used to declare class hierarchies in order
     #  check_size       'warn', 'error', 'ignore'    What to do if tp_basicsize does not match
     #  is_cyp_wrapper   boolean          Whether this extension type wraps a cypclass
+    #  wrapped_decl    string or None    The declaration code of the wrapped cypclass type when this is a cyp_wrapper
 
     is_extension_type = 1
     has_attributes = 1
     early_init = 1
     is_cyp_wrapper = 0
+    wrapped_decl = None
 
     objtypedef_cname = None